Quantitative Evaluation of Heavy Metals and Trace Elements in the Urinary Bladder: Comparison Between Cancerous, Adjacent Non-cancerous and Normal Cadaveric Tissue.

PubMed

Abdel-Gawad, Mahmoud; Elsobky, Emad; Shalaby, Mahmoud M; Abd-Elhameed, Mohamed; Abdel-Rahim, Mona; Ali-El-Dein, Bedeir

2016-12-01

The role of heavy metals and trace elements (HMTE) in the development of some cancers has been previously reported. Bladder carcinoma is a frequent malignancy of the urinary tract. The most common risk factors for bladder cancer are exposure to industrial carcinogens, cigarette smoking, gender, and possibly diet. The aim of this study was to evaluate HTME concentrations in the cancerous and adjacent non-cancerous tissues and compare them with those of normal cadaveric bladder. This prospective study included 102 paired samples of full-thickness cancer and adjacent non-cancerous bladder tissues of radical cystectomy (RC) specimens that were histologically proven as invasive bladder cancer (MIBC). We used 17 matched controls of non-malignant bladder tissue samples from cadavers. All samples were processed and evaluated for the concentration of 22 HMTE by using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Outcome analysis was made by the Mann-Whitney U, chi-square, Kruskal-Wallis, and Wilcoxon signed ranks tests. When compared with cadaveric control or cancerous, the adjacent non-cancerous tissue had higher levels of six elements (arsenic, lead, selenium, strontium, zinc, and aluminum), and when compared with the control alone, it had a higher concentration of calcium, cadmium, chromium, potassium, magnesium, and nickel. The cancerous tissue had a higher concentration of cadmium, lead, chromium, calcium, potassium, phosphorous, magnesium, nickel, selenium, strontium, and zinc than cadaveric control. Boron level was higher in cadaveric control than cancerous and adjacent non-cancerous tissue. Cadmium level was higher in cancerous tissue with node-positive than node-negative cases. The high concentrations of cadmium, lead, chromium, nickel, and zinc, in the cancerous together with arsenic in the adjacent non-cancerous tissues of RC specimens suggest a pathogenic role of these elements in BC. However, further work-up is needed to support this conclusion by the application of these HMTE on BC cell lines.

Elemental micro-PIXE mapping of hypersensitive lesions in Lagenaria sphaerica (Cucurbitaceae) resistant to Sphaerotheca fuliginea (powdery mildew)

NASA Astrophysics Data System (ADS)

Weiersbye-Witkowski, I. M.; Przybylowicz, W. J.; Straker, C. J.; Mesjasz-Przybylowicz, J.

1997-07-01

Genotypes of the Southern African cucurbit, Lagenaria sphaerica, that are resistant to powdery-mildew ( Sphaerotheca fuliginea) exhibit foliar hypersensitive (HS) lesions on inoculation with this fungal pathogen. Elemental distributions across radially symmetrical HS lesions, surrounding unlesioned leaf tissue and uninoculated leaf tissue, were obtained using the true elemental imaging system (Dynamic Analysis) of the NAC Van de Graaff nuclear microprobe. Raster scans of 3 MeV protons were complemented by simultaneous PIXE and BS point analyses. The composition of cellulose (C 6H 10O 5) was used as constant matrix composition for scans, and the sample thickness was found from BS spectra. Si and elements heavier than Ca contributed to matrix composition within HS lesions and the locally elevated Ca raised the limits of detection for some trace metals of interest. In comparison to uninoculated tissue, inoculated tissue was characterised by higher overall concentrations of all measured elements except Cu. Fully developed, 6 day-old HS lesions and the surrounding tissue could be divided into five zones, centred on the fungal infection site. Each zone was characterized by distinct local elemental distributions (either depletion, or accumulation to potentially phytotoxic levels).

Effect of short-term treatment with levosimendan on oxidative stress in renal tissues of rats.

PubMed

Gecit, Ilhan; Kavak, Servet; Yüksel, Mehmet Bilgehan; Basel, Halil; Bektas, Hava; Gümrükçüoglu, Hasan Ali; Meral, Ismail; Demir, Halit

2014-02-01

The aim of this study is to evaluate the influences of short-term treatment with levosimendan (chemical formula: C14H12N6O) on oxidative stress and some trace element levels in renal tissues of healthy rats. A total of 20 male Wistar-albino rats were randomly divided into two groups, each consisting of 10 rats. Animals in the first group were not treated with levosimendan and served as control. Animals in the second group were injected intraperitoneally with 12 µg/kg levosimendan and served as levosimendan group. Animals in both the groups were killed 3 days after the treatment, and their kidneys were harvested for the determination of tissue oxidant/antioxidant statues and trace element levels in renal tissues. The tissue malondialdehyde level was significantly (p < 0.001) lower in levosimendan group than in controls. The protective enzyme activities such as superoxide dismutase, catalase, and glutathione peroxidase and antioxidant glutathione level were significantly (p < 0.001) higher in levosimendan group than in controls. It was concluded that levosimendan reduced oxidative stress by avoiding lipid peroxidation and production of reactive oxygen species, and overactivating and/or increasing the protective antioxidant enzyme levels in renal tissues of rats. It is supposed that this experimental study provides beneficial data for clinicians in the management of renal tissue damage related to obstruction and/or ischemia.

Improved results of LINE-1 methylation analysis in formalin-fixed, paraffin-embedded tissues with the application of a heating step during the DNA extraction process.

PubMed

Wen, Xianyu; Jeong, Seorin; Kim, Younghoon; Bae, Jeong Mo; Cho, Nam Yun; Kim, Jung Ho; Kang, Gyeong Hoon

2017-01-01

Formalin-fixed, paraffin-embedded (FFPE) tissues are important resources for profiling DNA methylation changes and for studying a variety of diseases. However, formalin fixation introduces inter-strand crosslinking, which might cause incomplete bisulfite conversion of unmethylated cytosines, which might lead to falsely elevated measurements of methylation levels in pyrosequencing assays. Long interspersed nucleotide element-1 (LINE-1) is a major constituent of repetitive transposable DNA elements, and its methylation is referred to correlates with global DNA methylation. To identify whether formalin fixation might impact the measured values of methylation in LINE-1 repetitive elements and whether prolonged heat-induced denaturation of DNA might reduce the artificial increases in measured values caused by formalin fixation, we analyzed paired fresh-frozen (FF) and FFPE xenograft tissue samples for their methylation levels in LINE-1 using a pyrosequencing assay. To further confirm the effect of a heating step in the measurement of LINE-1 or single gene methylation levels, we analyzed FFPE tissue samples of gastric cancer and colorectal cancer for their methylation status in LINE-1 and eight single genes, respectively. Formalin fixation led to an increase in the measured values of LINE-1 methylation regardless of the duration of fixation. Prolonged heating of the DNA at 95 °C for 30 min before bisulfite conversion was found (1) to decrease the discrepancy in the measured values between the paired FF and FFPE tissue samples, (2) to decrease the standard deviation of the measured value of LINE-1 methylation levels in FFPE tissue samples of gastric cancer, and (3) to improve the performance in the measurement of single gene methylation levels in FFPE tissue samples of colorectal cancer. Formalin fixation leads to artificial increases in the measured values of LINE-1 methylation, and the application of prolonged heating of DNA samples decreases the discrepancy in the measured values of LINE-1 methylation between paired FF and FFPE tissue samples. The application of prolonged heating of DNA samples improves bisulfite conversion-based measurement of LINE-1 or single gene methylation levels in FFPE tissue samples.

Potential role of peroxisome proliferator activated receptor gamma activation on serum visfatin and trace elements in high fat diet induced type 2 diabetes mellitus.

PubMed

Tabassum, Arshia; Zaidi, Syeda Nuzhat Fatima; Yasmeen, Kausar; Mahboob, Tabassum

2018-07-15

Electrolytes and trace elements dysregulation play an important role in the progression of obesity and diabetes complications. The present study was designed to evaluate the insulin sensitizing effects of peroxisomes proliferators activated receptor gamma (PPAR-γ) agonist on trace elements in obesity induced type 2 diabetes mellitus and correlate with serum visfatin. Wistar rats were categorized into five groups. Group I served as control; Group II fed on high fat diet (HFD); Group III fed on HFD and treated with rosiglitazone (3 mg/kg) for 7 days; Group IV were T2DM rats induce by HFD and low dose of streptozotocin (i.p. 35 mg/kg); Group V was T2DM rats treated with rosiglitazone (3 mg/kg) for 7 days. Serum and tissues electrolytes levels and renal, hepatic and cardiac tissues trace elements were estimated by flame photometer and atomic absorption spectroscopy. Serum visfatin was estimated by ELISA. Pearson correlations were analyzed among fasting blood glucose (FBG), serum visfatin and tissues trace elements. Results of the current study showed hyponatremia, hyperkalemia, hypomagnesemia and hypercalcemia in HFD and T2DM groups. HFD and T2DM also showed elevated copper and iron levels; however, zinc and selenium levels were decreased. Rosiglitazone treatment increased the insulin sensitization and altered these changes. A Strong association was observed among FBG, serum visfatin and trace elements levels of HFD and T2DM. Obesity and diabetes mellitus disturbed visfatin, electrolytes and trace elements homeostasis. Rosiglitazone treatment restored these changes. The results of the study could serve as a basis for further studies for the prevention of diabetic complications. Copyright © 2018 Elsevier Inc. All rights reserved.

Theoretical Bounds for the Influence of Tissue-Level Ductility on the Apparent-Level Strength of Human Trabecular Bone

PubMed Central

Nawathe, Shashank; Juillard, Frédéric; Keaveny, Tony M.

2015-01-01

The role of tissue-level post-yield behavior on the apparent-level strength of trabecular bone is a potentially important aspect of bone quality. To gain insight into this issue, we compared the apparent-level strength of trabecular bone for the hypothetical cases of fully brittle versus fully ductile failure behavior of the trabecular tissue. Twenty human cadaver trabecular bone specimens (5 mm cube; BV/TV = 6–36%) were scanned with micro-CT to create 3D finite element models (22-micron element size). For each model, apparent-level strength was computed assuming either fully brittle (fracture with no tissue ductility) or fully ductile (yield with no tissue fracture) tissue-level behaviors. We found that the apparent-level ultimate strength for the brittle behavior was only about half the value of the apparent-level 0.2%-offset yield strength for the ductile behavior, and the ratio of these brittle to ductile strengths was almost constant (mean ± SD = 0.56 ± 0.02; n=20; R2 = 0.99 between the two measures). As a result of this small variation, although the ratio of brittle to ductile strengths was positively correlated with the bone volume fraction (R2=0.44, p=0.01) and structure model index (SMI, R2=0.58, p<0.01), these effects were small. Mechanistically, the fully ductile behavior resulted in a much higher apparent-level strength because in this case about 16-fold more tissue was required to fail than for the fully brittle behavior; also, there was more tensile- than compressive-mode of failure at the tissue level for the fully brittle behavior. We conclude that, in theory, the apparent-level strength behavior of human trabecular bone can vary appreciably depending on whether the tissue fails in a fully ductile versus fully brittle manner, and this effect is largely constant despite appreciable variations in bone volume fraction and microarchitecture. PMID:23497799

Determination of trace element level in different tissues of the leaping mullet (Liza saliens, Mugilidae) collected from Caspian Sea.

PubMed

Ebrahimzadeh, Mohammad Ali; Eslami, Shahram; Nabavi, Seyed Fazel; Nabavi, Seyed Mohammad

2011-12-01

The concentrations of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in the brain, heart, liver, gill, gonad, spleen, kidney, and red and white muscles of Liza saliens (leaping mullet). Trace element levels in fish samples were analyzed by flame atomic absorption spectrometry. Among the non-essential metals, the levels of Ni and Pb in the tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, the levels of the non-essential metals were much higher than those of manganese in the red and white muscles. Fe distribution pattern in tissues was in order of spleen > liver > heart > gill > brain > kidney > gonad > red muscle > white muscle. Red muscle was not within the safe limits for human consumption because non-essential metal (Ni, Pb) contents were higher than standard limits.

Pixe analysis of trace elements in tissues of rats treated with anticonvulsants

NASA Astrophysics Data System (ADS)

Hurd, R. W.; Van Rinsvelt, H. A.; Kinyua, A. M.; O'Neill, M. P.; Wilder, B. J.; Houdayer, A.; Hinrichsen, P. F.

1987-04-01

Several lines of evidence implicate metals in epilepsy. Anticonvulsant drugs are noted to alter levels of metals in humans and animals. PIXE analysis was used to investigate effects of three anticonvulsant drugs on tissue and brain cortex trace elements. The content of zinc and copper was increased in liver and spleen of rats treated with anticonvulsants while selenium was decreased in cortex.

Theoretical effects of fully ductile versus fully brittle behaviors of bone tissue on the strength of the human proximal femur and vertebral body.

PubMed

Nawathe, Shashank; Yang, Haisheng; Fields, Aaron J; Bouxsein, Mary L; Keaveny, Tony M

2015-05-01

The influence of the ductility of bone tissue on whole-bone strength represents a fundamental issue of multi-scale biomechanics. To gain insight, we performed a computational study of 16 human proximal femurs and 12 T9 vertebral bodies, comparing the whole-bone strength for the two hypothetical bounding cases of fully brittle versus fully ductile tissue-level failure behaviors, all other factors, including tissue-level elastic modulus and yield stress, held fixed. For each bone, a finite element model was generated (60-82 μm element size; up to 120 million elements) and was virtually loaded in habitual (stance for femur, compression for vertebra) and non-habitual (sideways fall, only for femur) loading modes. Using a geometrically and materially non-linear model, the tissue was assumed to be either fully brittle or fully ductile. We found that, under habitual loading, changing the tissue behavior from fully ductile to fully brittle reduced whole-bone strength by 38.3±2.4% (mean±SD) and 39.4±1.9% for the femur and vertebra, respectively (p=0.39 for site difference). These reductions were remarkably uniform across bones, but (for the femur) were greater for non-habitual (57.1±4.7%) than habitual loading (p<0.001). At overall structural failure, there was 5-10-fold less failed tissue for the fully brittle than fully ductile cases. These theoretical results suggest that the whole-bone strength of the proximal femur and vertebra can vary substantially between fully brittle and fully ductile tissue-level behaviors, an effect that is relatively insensitive to bone morphology but greater for non-habitual loading. Copyright © 2015 Elsevier Ltd. All rights reserved.

Occurrence and distribution of organochlorine pesticides, polychlorinated biphenyls, and trace elements in fish tissue in the lower Tennessee River basin, 1980-98

USGS Publications Warehouse

Knight, R.R.; Powell, J.R.

2001-01-01

The U.S. Geological Survey, as part of the National Water-Quality Assessment Program, evaluated the occurrence and distribution of organochlorine pesticides, polychlorinated biphenyls, and trace elements in fish tissue in samples collected in the lower Tennessee River Basin study unit. Fish tissue analysis provides a time-averaged measurement of contaminants as well as a direct measurement of the contaminants that bioaccumulate in fish tissue. Bioaccumulation of contaminants in fish tissue may result in concentrations that can affect human, wildlife, or aquatic health. Data for two types of tissue analyses were evaluated to assess the occurrence and distribution of contaminants: whole fish for organochlorine pesticides and polychlorinated biphenyls and fish fillets for organochlorine pesticides, polychlorinated biphenyls, and trace elements. The fish tissue data analyzed for this study cover an 18-year span including data collected in 1998 by the U.S. Geological Survey as part of the National Water-Quality Assessment Program; data collected from 1980 through 1997 by the Tennessee Valley Authority; and data collected from 1992 through 1997 by the Tennessee Department of Environment and Conservation. Concentration data for constituents that are on the U.S. Environmental Protection Agency Priority Pollutant List were summarized and compared against existing action levels or guidelines.From the list of organochlorine pesticide compounds analyzed, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), a breakdown product of dichlorodiphenyltrichloroethane (DDT), was the most commonly detected compound with detections at 83 percent of the sites sampled. Eleven p,p'-DDE samples exceeded action levels or guidelines with concentrations ranging from 0.20 to 12.8 milligrams per kilogram. Five other organochlorine compounds, p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), dieldrin, endrin, chlordane, and polychlorinated biphenyls, also exceeded action levels and guidelines, but the detection frequencies at sampling sites generally were less than 70 percent. Mercury, the only trace element to exceed a guideline, was detected at 51 of 102 sites sampled for trace elements. Selenium was detected in fish fillet samples from 70 of 102 sites sampled, which was more sites than for any other trace element; however, selenium did not exceed the 50 micrograms per gram U.S. Environmental Protection Agency screening criteria. Arsenic and cadmium also were detected at 44 and 54 percent of the sampling sites, respectively.

Bioacumulation of trace elements in hepatic and renal tissues of the white mullet Mugil curema Valenciennes, 1836 (Actinopterygii, Mugilidae) in two coastal systems in southeastern Brazil

NASA Astrophysics Data System (ADS)

Fernandez, W. S.; Dias, J. F.; Boufleur, L. A.; Amaral, L.; Yoneama, M. L.; Dias, J. F.

2014-01-01

The aim of this study is to investigate the presence and the concentration of trace elements in hepatic and renal tissues of white mullet (Mugil curema) by Particle-induced X-ray emission (PIXE). Fish specimens were collected in two coastal areas of São Paulo state-Brazil: the Santos estuary (from March 2009 to February 2010) and the Cananéia-Iguape coastal estuarine system (from May 2008 to April 2009). For the elemental analysis, n = 470 sample tissues (liver and kidney) were pooled according to location and type of organ. Trace elements such as Fe, Cu, Zn and Br were observed in both tissues of M. curema with concentrations ranging from 800 μg g-1 for Fe to 7 μg g-1 for Cu. The concentrations of Cu and Zn showed statistical significant differences among the tissues of M. curema (p < 0.05). Relatively higher concentrations of Cu and Zn were observed in the liver tissue. There was no significantly difference in the elemental concentrations between the two studied areas. The Cu levels in liver tissues of M. curema were found to be above the maximum limits for consumption, according to the United States Environmental Protection Agency (EPA) and Brazilian National Health Surveillance Agency (ANVISA).

Root anatomy and element distribution vary between two Salix caprea isolates with different Cd accumulation capacities

PubMed Central

Vaculík, Marek; Konlechner, Cornelia; Langer, Ingrid; Adlassnig, Wolfram; Puschenreiter, Markus; Lux, Alexander; Hauser, Marie-Theres

2012-01-01

The understanding of the influence of toxic elements on root anatomy and element distribution is still limited. This study describes anatomical responses, metal accumulation and element distribution of rooted cuttings of Salix caprea after exposure to Cd and/or Zn. Differences in the development of apoplastic barriers and tissue organization in roots between two distinct S. caprea isolates with divergent Cd uptake and accumulation capacities in leaves might reflect an adaptive predisposition based on different natural origins. Energy-dispersive X-ray spectroscopy (EDX) revealed that Cd and Zn interfered with the distribution of elements in a tissue- and isolate-specific manner. Zinc, Ca, Mg, Na and Si were enriched in the peripheral bark, K and S in the phloem and Cd in both vascular tissues. Si levels were lower in the superior Cd translocator. Since the cuttings originated from stocks isolated from polluted and unpolluted sites we probably uncovered different strategies against toxic elements. PMID:22325439

Contamination Status of Seven Elements in Hooded Cranes Wintering in South-West Kyushu, Japan: Comparison with Red-Crowned Cranes in Hokkaido, Japan.

PubMed

Teraoka, Hiroki; Miyagi, Hasumi; Haraguchi, Yuko; Takase, Kozo; Kitazawa, Takio; Noda, Jun

2018-05-31

The hooded crane is designated as an endangered species. The cranes breed primarily in wetlands in southeast Russia and China in summer. Most of the hooded crane population winters in the Izumi plain in Japan. It is difficult to know the contamination status of their habitat because of their vast breeding area. We determined the levels of Cd, Pb, As, (total) Hg, Se, Zn, and Cu in the liver, kidney, and muscle of hooded cranes that were found dead in Izumi in the periods 2003-2006 and 2014-2015 compared with the levels in red-crowned cranes in Hokkaido, Japan, as the only cranes in which these elements had been studied extensively. There were no notable differences between levels of the seven elements in the two periods. Overall, tissue levels of the elements examined in hooded cranes were comparable to those in red-crowned cranes except for Hg and Se. Tissue levels of Hg and Se were clearly lower in hooded cranes than in red-crowned cranes that were found dead from 2000. One lead poisoning case was confirmed. The results suggest that Hooded cranes wintering in Izumi are not extensively contaminated with the seven elements examined.

Finite Element-Based Mechanical Assessment of Bone Quality on the Basis of In Vivo Images.

PubMed

Pahr, Dieter H; Zysset, Philippe K

2016-12-01

Beyond bone mineral density (BMD), bone quality designates the mechanical integrity of bone tissue. In vivo images based on X-ray attenuation, such as CT reconstructions, provide size, shape, and local BMD distribution and may be exploited as input for finite element analysis (FEA) to assess bone fragility. Further key input parameters of FEA are the material properties of bone tissue. This review discusses the main determinants of bone mechanical properties and emphasizes the added value, as well as the important assumptions underlying finite element analysis. Bone tissue is a sophisticated, multiscale composite material that undergoes remodeling but exhibits a rather narrow band of tissue mineralization. Mechanically, bone tissue behaves elastically under physiologic loads and yields by cracking beyond critical strain levels. Through adequate cell-orchestrated modeling, trabecular bone tunes its mechanical properties by volume fraction and fabric. With proper calibration, these mechanical properties may be incorporated in quantitative CT-based finite element analysis that has been validated extensively with ex vivo experiments and has been applied increasingly in clinical trials to assess treatment efficacy against osteoporosis.

Primary Teeth and Hair as Indicators of Environmental Pollution.

PubMed

Shishniashvili, T E; Suladze, N N; Margvelashvili, V V

2016-01-01

To study the influence of environmental pollution on the mineralization of dental hard tissues by using biosubstrates: teeth and hair. : At the first stage epidemiological survey was conducted in polluted and less polluted areas of Tbilisi (Georgia). We studied 525 children aged 3 and 4 years. Caries prevalence and intensity was defined by the methodology of World Health Organization. At the second stage the chemical elements content was studied in hair and teeth hard tissues of 24 children by X-ray fluorescent spectroscopy method. The prevalence of dental caries in the polluted region was 46%, caries intensity--1.92 (± 2.842). In the less polluted region prevalence was 37%, caries intensity--1.47 (± 2.571). These data are statistically reliable (p < 0.05). The study of hair and tooth tissues showed that the toxic elements (Pb, Hg, Sn, Ti) content in these tissues was higher in environmentally unfavorable than in favorable conditions. Hair and dental tissues can be used as indicators of environmental pollution. Our survey showed that toxic elements content in dental hard tissues was higher and the level of essential elements was less in polluted than in less polluted areas of Tbilisi.

[The direct AAS determination of micro elements in hair and nail by base-digestion].

PubMed

Ju, Hong-fang

2002-08-01

The study of micro elements is more and more extensively, and people can gain some informations by the level of micro elements in tissue. This paper tempts to dissolve hair or nail in 2 mol.L-1 NaOH and determinate nine micro elements including calcium, zinc, iron, manganese, nickel, cadmium, copper, lead and bismuth in them by base-digestion with FAAS and GFAAS. It shows that the measured value of these elements is coincident with reference articles reported, except bismuth. The elements' percent recoveries are 90.0%-110.8%. The result also shows that the level of zinc and copper in hair are higher than in nail, and the level of bismuth, cadmium and iron in hair are lower than in nail, but the level of micro elements in hair and in nail are not correlative.

Identification of Transposable Elements Contributing to Tissue-Specific Expression of Long Non-Coding RNAs

PubMed Central

Chishima, Takafumi; Iwakiri, Junichi

2018-01-01

It has been recently suggested that transposable elements (TEs) are re-used as functional elements of long non-coding RNAs (lncRNAs). This is supported by some examples such as the human endogenous retrovirus subfamily H (HERVH) elements contained within lncRNAs and expressed specifically in human embryonic stem cells (hESCs), as required to maintain hESC identity. There are at least two unanswered questions about all lncRNAs. How many TEs are re-used within lncRNAs? Are there any other TEs that affect tissue specificity of lncRNA expression? To answer these questions, we comprehensively identify TEs that are significantly related to tissue-specific expression levels of lncRNAs. We downloaded lncRNA expression data corresponding to normal human tissue from the Expression Atlas and transformed the data into tissue specificity estimates. Then, Fisher’s exact tests were performed to verify whether the presence or absence of TE-derived sequences influences the tissue specificity of lncRNA expression. Many TE–tissue pairs associated with tissue-specific expression of lncRNAs were detected, indicating that multiple TE families can be re-used as functional domains or regulatory sequences of lncRNAs. In particular, we found that the antisense promoter region of L1PA2, a LINE-1 subfamily, appears to act as a promoter for lncRNAs with placenta-specific expression. PMID:29315213

Quantitative analysis of biomedical samples using synchrotron radiation microbeams

NASA Astrophysics Data System (ADS)

Ektessabi, Ali; Shikine, Shunsuke; Yoshida, Sohei

2001-07-01

X-ray fluorescence (XRF) using a synchrotron radiation (SR) microbeam was applied to investigate distributions and concentrations of elements in single neurons of patients with neurodegenerative diseases. In this paper we introduce a computer code that has been developed to quantify the trace elements and matrix elements at the single cell level. This computer code has been used in studies of several important neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and parkinsonism-dementia complex (PDC), as well as in basic biological experiments to determine the elemental changes in cells due to incorporation of foreign metal elements. The substantial nigra (SN) tissue obtained from the autopsy specimens of patients with Guamanian parkinsonism-dementia complex (PDC) and control cases were examined. Quantitative XRF analysis showed that neuromelanin granules of Parkinsonian SN contained higher levels of Fe than those of the control. The concentrations were in the ranges of 2300-3100 ppm and 2000-2400 ppm respectively. On the contrary, Zn and Ni in neuromelanin granules of SN tissue from the PDC case were lower than those of the control. Especially Zn was less than 40 ppm in SN tissue from the PDC case while it was 560-810 ppm in the control. These changes are considered to be closely related to the neuro-degeneration and cell death.

Relationship between soil cobalt and vitamin B12 levels in the liver of livestock in Saudi Arabia: role of competing elements in soils.

PubMed

Huwait, Etimad A; Kumosani, Taha A; Moselhy, Said S; Mosaoa, Rami M; Yaghmoor, Soonham S

2015-09-01

This study aimed to analyze the agricultural soils from different regions in Saudi Arabia for cobalt and related metals as Cu(2+), Ni(2+), Cr(3+), Zn(2+) and Pb(2+). Liver and muscle tissues of livestock grazing on the selected areas were analyzed for the content of Co and vitamin B12. Our results indicated that the levels of Co in surface soil (0-15 cm) were higher than in sub-surface soil (>15 cm-45 cm). In contrast, Pb and Zn were higher in sub-surface soil than in surface soil. A significant positive correlation existed between the levels of Co and vitamin B12 in the liver of livestock. However, Co was not detected in muscle tissues while vitamin B12 was present at very low levels in comparison with the levels found in the liver. The results indicated that Zn(2+), Pb(2+) compete with Co in soil, which eventually affected the levels of vitamin B12 in liver. It was recommended that survey of heavy metals in grazing fields of cattle should consider inclusion of multiple elements that compete with the bioavailability of essential elements in plants and animals for the prevention of deficiency of essential elements such as Co.

Multielemental analysis of tissues from Cangrande della Scala, Prince of Verona, in the 14th century.

PubMed

Apostoli, Pietro; De Palma, Giuseppe; Catalani, Simona; Bortolotti, Federica; Tagliaro, Franco

2009-01-01

Cangrande della Scala, Prince of Verona (Italy), died suddenly shortly after his triumph in the battle of Treviso (July 18, 1329). Thus, in the frame of a multidisciplinary paleo-pathological study, we carried out a multielemental analysis on the Prince's tissue specimens, including hair, liver, muscle, and bone, in order to characterize a multitissue profile of metallic elements in a nobleman of the 14th century. Biological specimens were analyzed by inductively coupled plasma-mass spectrometry. We were able to rule out arsenic poisoning as the primary cause of death. High levels of gold and silver in both hair and liver samples were probably due to prolonged contact of the mummy with precious metals in the funeral garments. High lead concentrations in both liver and bone tissue can be traced back to the ingestion of contaminated food and alcoholic beverages. Most of the essential elements were in the normal range of values for contemporary living people. The low arsenic and chromium levels in the Prince's tissues as compared to modern people would be suggestive of raised concentrations of both the elements in the present era, which are likely due to industrial pollution.

Analysis of iron, zinc, selenium and cadmium in paraffin-embedded prostate tissue specimens using inductively coupled plasma mass-spectrometry

USGS Publications Warehouse

Sarafanov, A.G.; Todorov, T.I.; Kajdacsy-Balla, A.; Gray, Michael A.; MacIas, V.; Centeno, J.A.

2008-01-01

Formalin-fixed paraffin-embedded (FFPE) tissue specimens represent a valuable and abundant resource of pathologic material for various biomedical studies. In the present study, we report the application of high-resolution inductively coupled mass-spectrometry (ICP-MS) for quantification of Fe, Zn, Se and Cd in FFPE prostate tissue. These elements have a possible role in the development of prostate diseases: while Zn and Se are needed for a healthy prostate, Cd shows multiple toxic and carcinogenic effects. Excessive accumulation of Fe induces the production of highly reactive hydroxyl radical species, which may play a role in cancer etiopathogenesis. To assess whether the levels of these metals in the FFPE prostate tissue represent their original content, we compared their levels with those in the fresh tissue (on dry weight basis) in samples obtained from 15 patients. We found that in FFPE tissue, the recoveries of Se, Fe, Cd and Zn were progressively decreased, 97??11% (r=0.88), 82??22% (r=0.86), 59??23% (r=0.69) and 24??11% (r=0.38), respectively. Thus, the use of correction factors, determined as k=0.16 for Se, k=0.20 for Fe, k=0.27 for Cd and k=0.67 for Zn, is required to estimate the retrospective levels of these elements in the parental non-processed fresh (wet) prostate tissue. The technique used in this study enables the analysis of archival FFPE prostate tissue for the concentrations of Fe, Zn, Se and Cd to study association between the levels of these metals and prostate disease. ?? 2008.

Rare earth elements in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic.

PubMed

MacMillan, Gwyneth Anne; Chételat, John; Heath, Joel P; Mickpegak, Raymond; Amyot, Marc

2017-10-18

Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environmental impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. Northern ecosystems are potentially vulnerable to REE enrichment from prospective mining projects at high latitudes. To understand how REEs behave in remote northern food webs, we measured REE concentrations and carbon and nitrogen stable isotope ratios (∂ 15 N, ∂ 13 C) in biota from marine, freshwater, and terrestrial ecosystems of the eastern Canadian Arctic (N = 339). Wildlife harvesting and tissue sampling was partly conducted by local hunters through a community-based monitoring project. Results show that REEs generally follow a coherent bioaccumulation pattern for sample tissues, with some anomalies for redox-sensitive elements (Ce, Eu). Highest REE concentrations were found at low trophic levels, especially in vegetation and aquatic invertebrates. Terrestrial herbivores, ringed seal, and fish had low total REE levels in muscle tissue (∑REE for 15 elements <0.1 nmol g -1 ), yet accumulation was an order of magnitude higher in liver tissues. Age- and length-dependent REE accumulation also suggest that REE uptake is faster than elimination for some species. Overall, REE bioaccumulation patterns appear to be species- and tissue-specific, with limited potential for biomagnification. This study provides novel data on the behaviour of REEs in ecosystems and will be useful for environmental impact assessment of REE enrichment in northern regions.

Macro- and microelements in the rat liver, kidneys, and brain tissues; sex differences and effect of blood removal by perfusion in vivo.

PubMed

Orct, Tatjana; Jurasović, Jasna; Micek, Vedran; Karaica, Dean; Sabolić, Ivan

2017-03-01

Concentrations of macro- and microelements in animal organs indicate the animal health status and represent reference data for animal experiments. Their levels in blood and tissues could be different between sexes, and could be different with and without blood in tissues. To test these hypotheses, in adult female and male rats the concentrations of various elements were measured in whole blood, blood plasma, and tissues from blood-containing (nonperfused) and blood-free liver, kidneys, and brain (perfused in vivo with an elements-free buffer). In these samples, 6 macroelements (Na, Mg, P, S, K, Ca) and 14 microelements (Fe, Mn, Co, Cu, Zn, Se, I, As, Cd, Hg, Pb, Li, B, Sr) were determined by inductively coupled plasma mass spectrometry following nitric acid digestion. In blood and plasma, female- or male-dominant sex differences were observed for 6 and 5 elements, respectively. In nonperfused organs, sex differences were observed for 3 (liver, brain) or 9 (kidneys) elements, whereas in perfused organs, similar differences were detected for 9 elements in the liver, 5 in the kidneys, and none in the brain. In females, perfused organs had significantly lower concentrations of 4, 5, and 2, and higher concentrations of 10, 4, and 7 elements, respectively, in the liver, kidneys, and brain. In males, perfusion caused lower concentrations of 4, 7, and 2, and higher concentrations of 1, 1, and 7 elements, respectively, in the liver, kidneys, and brain. Therefore, the residual blood in organs can significantly influence tissue concentrations of various elements and their sex-dependency. Copyright © 2017 Elsevier GmbH. All rights reserved.

Concentrations of selected trace elements in fish tissue and streambed sediment in the Clark Fork-Pend Oreille and Spokane River basins, Washington, Idaho, and Montana, 1998

USGS Publications Warehouse

Maret, Terry R.; Skinner, K.D.

2000-01-01

Fish tissue and bed sediment samples were collected from 16 stream sites in the Northern Rockies Intermontane Basins study area in 1998 as part of the U.S. Geological Survey National Water-Quality Assessment Program. Bed sediment samples were analyzed for 45 trace elements, and fish livers and sportfish fillets were analyzed for 22 elements to characterize the occurrence and distribution of these elements in relation to stream characteristics and land use activities. Nine trace elements of environmental concern—arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc—were detected in bed sediment, but not all of these elements were detected in fish tissue. Trace-element concentrations were highest in bed sediment samples collected at sites downstream from significant natural mineral deposits and (or) mining activities. Arsenic, cadmium, copper, lead, mercury, and zinc in bed sediment at some sites were elevated relative to national median concentrations, and some concentrations were at levels that can adversely affect aquatic biota. Although trace-element concentrations in bed sediment exceeded various guidelines, no concentrations in sportfish fillets exceeded U.S. Environmental Protection Agency screening values for the protection of human health. Correlations between most trace-element concentrations in bed sediment and fish tissue (liver and fillet) were not significant (r0.05). Concentrations of arsenic, cadmium, copper, lead, mercury, nickel, selenium, and zinc in bed sediment were significantly correlated (r=0.53 to 0.88, p2=0.95 and 0.99, p<0.001) that corresponded to trace-element enrichment categories. These strong relations warrant further study using mine density as an explanatory variable to predict trace-element concentrations in bed sediment.

Determination of lead in bone tissues by axially viewed inductively coupled plasma multichannel-based emission spectrometry.

PubMed

Grotti, Marco; Abelmoschi, Maria Luisa; Dalla Riva, Simona; Soggia, Francesco; Frache, Roberto

2005-04-01

A new procedure for determining low levels of lead in bone tissues has been developed. After wet acid digestion in a pressurized microwave-heated system, the solution was analyzed by inductively coupled plasma multichannel-based emission spectrometry. Internal standardization using the Co 228.615 nm reference line was chosen as the optimal method to compensate for the matrix effects from the presence of calcium and nitric acid at high concentration levels. The detection limit of the procedure was 0.11 microg Pb g(-1) dry mass. Instrumental precision at the analytical concentration of approximately 10 microg l(-1) ranged from 6.1 to 9.4%. Precision of the sample preparation step was 5.4%. The concentration of lead in SRM 1486 (1.32+/-0.04 microg g(-1)) found using the new procedure was in excellent agreement with the certified level (1.335+/-0.014 microg g(-1)). Finally, the method was applied to determine the lead in various fish bone tissues, and the analytical results were found to be in good agreement with those obtained through differential pulse anodic stripping voltammetry. The method is therefore suitable for the reliable determination of lead at concentration levels of below 1 microg g(-1) in bone samples. Moreover, the multi-element capability of the technique allows us to simultaneously determine other major or trace elements in order to investigate inter-element correlation and to compute enrichment factors, making the proposed procedure particularly useful for investigating lead occurrence and pathways in fish bone tissues in order to find suitable biomarkers for the Antarctic marine environment.

[Studies on the presence of metal traces in tissue surrounding A.O. angle plates, based on neutron activation analysis (author's transl)].

PubMed

Michel, R; Zilkens, J

1978-01-01

Using instrumental neutron activation analysis, 11 samples of tissue in contact with A.O. angle plates and 8 samples of fascial tissue were examined for their content of trace elements, half a year to 5 1/2 years after hip joint intertrochanteric osteotomies. Significant increases in the concentrations of the elements Cr, Fe, Co, Ni and Mo, all of which are contained in the A. O. steel plates (V4A steel), were found both in the contact tissue and in the tissue of the fascia lata femoris about 4--8 cm away from the angle plates, whereas the levels of concentration of elements not specific for the alloy in question, namely, Zn, Se, Rb and Cs, were normal or just subnormal. It was possible to prove by means of element correlations that the elements Cr, Co, Ni and Mo are present in constant ratios in those tissue samples which are loaded with traces of metals foreign to the body. However, only the Mo:Cr ratio corresponds to that of the angle plates. The authors considered Ni to be a useful indicator for the degree of metal loading of a tissue, since Ni will normally occur in human tissue in very low concentrations (less than or equal to 10(-6) g/g dry substance) and was identified by the authors--contrary to previous studies--even in the fascial tissue located up to 8 cm away from the contact tissue. Non-linear correlations were found between iron and the other components of the steel, reflecting the complicated regulatory mechanisms governing the presence of iron in the organism. The results of the analysis are discussed in respect of possible long-term action of the implantate components liberated by corrosion, which, in case of long-term implantates might place an overall burden of foreign ions on the body.

Concentrations of 17 elements in the zebra mussel (Dreissena polymorpha), in different tissues of perch (Perca fluviatilis), and in perch intestinal parasites (Acanthocephalus lucii) from the subalpine lake Mondsee, Austria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sures, B.; Steiner, W.; Rydlo, M.

1999-11-01

Concentrations of the elements Al, Ag, Ba, ca, Cd, Co, Cr, cu, Fe, Ga, Mg, Mn, Ni, Pb, Sr, Tl, and Zn were analyzed by inductively coupled plasma mass spectrometry in the acanthocephalan Acanthocephalus lucii (Mueller); in its host, Perca fluviatilis (L.), and in the soft tissue of the zebra mussel, Dreissena polymorpha (Pallas). All animals were collected from the same sampling site in a subalpine lake, Mondsee, in Austria. Most of the elements were found at significantly higher concentrations in the acanthocephalan than in different tissues (muscle, liver, and intestinal wall) of its perch host. Only Co was concentratedmore » in the liver of perch to a level that was significantly higher than that found in the parasite. Most of the analyzed elements were also present at significantly higher concentrations in A. lucii than in D. polymorpha. Barium and Cr were the only elements recorded at higher concentrations in the mussel compared with the acanthocephalan. Thus, when comparing the accumulation of elements, the acanthocephalans appear to be even more suitable than the zebra mussels in terms of their use in the detection of metal contamination within aquatic biotopes. Spearman correlation analysis revealed that the concentrations of several elements within the parasites decreased with increasing infrapopulation. Furthermore, the levels of some elements in the perch liver were negatively correlated with the weight of A. lucii in the intestine. Thus, it emerged that not only is there competition for elements between acanthocephalans inside the gut but there is also competition for these elements between the host and the parasites. The elevated element concentrations demonstrated here in the parasitic worm A. lucii provide support for further investigations of these common helminthes and of their accumulation properties.« less

Analysis of major elements in pigmented melanocytic chicken skin using laser-induced breakdown spectroscopy.

PubMed

Lee, Jong Jin; Moon, Youngmin; Han, Jung Hyun; Jeong, Sungho

2017-04-01

The concentration difference of major elements in melanocytic skin with respect to pigmentation level is analysed by laser-induced breakdown spectroscopy (LIBS) to investigate the applicability of LIBS as an in situ feedback tool for selective and complete laser removal of melanocytic skin tissue like nevus. The skin of black silkie chicken which had a characteristic darkly pigmented perifollicular skin surrounded by lightly pigmented extrafollicular skin was used as the sample. The results showed higher LIBS signal intensities of Ca 2+ and Mg 2+ but lower intensities of Na + , Cl - and K + in the perifollicular skin than in the extrafollicular skin, which demonstrated the feasibility to use LIBS as a reliable method to distinguish skin tissues with difference in pigmentation level. Plasma emission of biochemical elements generated with a laser irradiation on melanocytic skin lesion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemometric evaluation of concentrations of trace elements in intervertebral disc tissue in patient with degenerative disc disease.

PubMed

Kubaszewski, Łukasz; Zioła-Frankowska, Anetta; Gasik, Zuzanna; Frankowski, Marcin; Dąbrowski, Mikołaj; Molisak, Bartłomiej; Kaczmarczyk, Jacek; Gasik, Robert

2017-12-23

The work is designed to uncover the pattern of mutual relation among trace elements and epidemiological data in the degenerated intervertebral disk tissue in humans. Hitherto the reason of the degenerative process is not fully understood. Trace elements are the basic components of the biological compound related both its metabolism as well as environmental exposure. The relation pattern among elements occurs gives new perspective in solving the cause of the disease. We have analysed trace elements content in the 30 intervertebral disc from 22 patients with degenerative disc disease. The concentrations of Al, Cu, Cd, Mo, Ni and Pb were determined with Atomic Absorption Spectrometry. To analyse the multidimentional relation between trace element concentration and epidemiological data the chemometric analysis was applied. The similarity have been shown in occurrence of following pairs: Cd-Mo as well as Mg-Zn. The second pair was correlated with Pb concentration. Pb levels are observed to be competitive to Cu concentration. Cd concentration was related to Zn and Mg deficiency. No single but rather cluster of epidemiological data show observable influence on the TE tissue variance. Zn and Cu was related to the male sex. Operation with orthopedic implants were related to combined Al, Mo and Zn concentration. This is the first chemometric analysis of trace elements in disk tissue. It shows multidimentional relations that are missed by the classical statistic. The analysis shows significant relation. The nature of the relations is the basis for further metabolic and environmental research.

[Measurement of the status of trace elements in cattle using liver biopsy samples].

PubMed

Ouweltjes, W; de Zeeuw, A C; Moen, A; Counotte, G H M

2007-02-01

Serum, plasma, or urine samples are usually used for the measurement of the trace elements copper; zinc, iron, selenium, because these samples are easy to obtain; however; these samples are not always appropriate. For example, it is not possible to measure molybdenum, the major antagonist of copper; in blood or urine. Therefore measurement of trace elements in liver tissue is considered the gold standard. For the assessment of selenium the method of choice remains determination of glutathion peroxidase in erythrocytes and for the assessment of magnesium determination of magnesium in urine. We determined the accuracy and repeatability of measuring trace elements in liver biopsies and whole liver homogenates. The levels of trace elements measured were similar in both preparations (92% agreement). Liver biopsy in live animals is a relatively simple procedure but not common in The Netherlands. Reference levels of trace elements, classified as too low, low, adequate, high, and too high, were established on the basis of our research and information in the literature. In a second study we investigated the practical aspects of obtaining liver tissue samples and their use. Samples were collected from cattle on a commercial dairy farm. Liver biopsy provided additional information to that obtained from serum and urine samples. We prepared a biopsy protocol and a test package, which we tested on 14 farms where an imbalance of trace minerals was suspected. Biopsy samples taken from 4 to 6 animals revealed extreme levels of trace elements.

Detection of Genetically Altered Copper Levels in Drosophila Tissues by Synchrotron X-Ray Fluorescence Microscopy

PubMed Central

Lye, Jessica C.; Hwang, Joab E. C.; Paterson, David; de Jonge, Martin D.; Howard, Daryl L.; Burke, Richard

2011-01-01

Tissue-specific manipulation of known copper transport genes in Drosophila tissues results in phenotypes that are presumably due to an alteration in copper levels in the targeted cells. However direct confirmation of this has to date been technically challenging. Measures of cellular copper content such as expression levels of copper-responsive genes or cuproenzyme activity levels, while useful, are indirect. First-generation copper-sensitive fluorophores show promise but currently lack the sensitivity required to detect subtle changes in copper levels. Moreover such techniques do not provide information regarding other relevant biometals such as zinc or iron. Traditional techniques for measuring elemental composition such as inductively coupled plasma mass spectroscopy are not sensitive enough for use with the small tissue amounts available in Drosophila research. Here we present synchrotron x-ray fluorescence microscopy analysis of two different Drosophila tissues, the larval wing imaginal disc, and sectioned adult fly heads and show that this technique can be used to detect changes in tissue copper levels caused by targeted manipulation of known copper homeostasis genes. PMID:22053217

Hyperspectral microscope for in vivo imaging of microstructures and cells in tissues

DOEpatents

Demos,; Stavros, G [Livermore, CA

2011-05-17

An optical hyperspectral/multimodal imaging method and apparatus is utilized to provide high signal sensitivity for implementation of various optical imaging approaches. Such a system utilizes long working distance microscope objectives so as to enable off-axis illumination of predetermined tissue thereby allowing for excitation at any optical wavelength, simplifies design, reduces required optical elements, significantly reduces spectral noise from the optical elements and allows for fast image acquisition enabling high quality imaging in-vivo. Such a technology provides a means of detecting disease at the single cell level such as cancer, precancer, ischemic, traumatic or other type of injury, infection, or other diseases or conditions causing alterations in cells and tissue micro structures.

Multi-Frequency Harmonics Technique for HIFU Tissue Treatment

NASA Astrophysics Data System (ADS)

Rybyanets, Andrey N.; Lugovaya, Maria A.; Rybyanets, Anastasia A.

2010-03-01

New technique for enhancing of tissue lysis and enlarging treatment volume during one HIFU sonification is proposed. The technique consists in simultaneous or alternative (at optimal repetition frequency) excitation of single element HIFU transducer on a frequencies corresponding to odd natural harmonics of piezoceramic element at ultrasound energy levels sufficient for producing cavitational, thermal or mechanical damage of fat cells at each of aforementioned frequencies. Calculation and FEM modeling of transducer vibrations and acoustic field patterns for different frequencies sets were performed. Acoustic pressure in focal plane was measured in water using calibrated hydrophone and 3D acoustic scanning system. In vitro experiments on different tissues and phantoms confirming the advantages of multifrequency harmonic method were performed.

Laser diagnostics of native cervix dabs with human papilloma virus in high carcinogenic risk

NASA Astrophysics Data System (ADS)

Peresunko, O. P.; Karpenko, Ju. G.; Burkovets, D. N.; Ivashko, P. V.; Nikorych, A. V.; Yermolenko, S. B.; Gruia, Ion; Gruia, M. J.

2015-11-01

The results of experimental studies of coordinate distributions of Mueller matrix elements of the following types of cervical scraping tissue are presented: rate- low-grade - highly differentiated dysplasia (CIN1-CIN3) - adenocarcinoma of high, medium and low levels of differentiation (G1-G3). The rationale for the choice of statistical points 1-4 orders polarized coherent radiation field, transformed as a result of interaction with the oncologic modified biological layers "epithelium-stroma" as a quantitative criterion of polarimetric optical differentiation state of human biological tissues are shown here. The analysis of the obtained Mueller matrix elements and statistical correlation methods, the systematized by types studied tissues is accomplished. The results of research images of Mueller matrix elements m34 for this type of pathology as low-grade dysplasia (CIN2), the results of its statistical and correlation analysis are presented.

Organochlorine compounds and trace elements in fish tissue and bed sediments in the lower Snake River basin, Idaho and Oregon

USGS Publications Warehouse

Clark, Gregory M.; Maret, Terry R.

1998-01-01

Fish-tissue and bed-sediment samples were collected to determine the occurrence and distribution of organochlorine compounds and trace elements in the lower Snake River Basin. Whole-body composite samples of suckers and carp from seven sites were analyzed for organochlorine compounds; liver samples were analyzed for trace elements. Fillets from selected sportfish were analyzed for organochlorine compounds and trace elements. Bed-sediment samples from three sites were analyzed for organochlorine compounds and trace elements. Twelve different organochlorine compounds were detected in 14 fish-tissue samples. All fish-tissue samples contained DDT or its metabolites. Concentrations of total DDT ranged from 11 micrograms per kilogram wet weight in fillets of yellow perch from C.J. Strike Reservoir to 3,633 micrograms per kilogram wet weight in a whole-body sample of carp from Brownlee Reservoir at Burnt River. Total DDT concentrations in whole-body samples of sucker and carp from the Snake River at C.J. Strike Reservoir, Snake River at Swan Falls, Snake River at Nyssa, and Brownlee Reservoir at Burnt River exceeded criteria established for the protection of fish-eating wildlife. Total PCB concentrations in a whole-body sample of carp from Brownlee Reservoir at Burnt River also exceeded fish-eating wildlife criteria. Concentrations of organochlorine compounds in whole-body samples, in general, were larger than concentrations in sportfish fillets. However, concentrations of dieldrin and total DDT in fillets of channel catfish from the Snake River at Nyssa and Brownlee Reservoir at Burnt River, and concentrations of total DDT in fillets of smallmouth bass and white crappie from Brownlee Reservoir at Burnt River exceeded a cancer risk screening value of 10-6 established by the U.S. Environmental Protection Agency. Concentrations of organochlorine compounds in bed sediment were smaller than concentrations in fish tissue. Concentrations of p,p'DDE, the only compound detected in all three bed-sediment samples, ranged from 1.1 micrograms per kilogram dry weight in C.J. Strike Reservoir to 11 micrograms per kilogram dry weight in Brownlee Reservoir at Burnt River. Data from this study, compared with data collected in the upper Snake River Basin from 1992 to 1994, indicates that, in general, organochlorine concentrations in fish tissue and bed sediment increased from the headwaters of the Snake River in Wyoming downstream to Brownlee Reservoir. The largest trace-element concentrations in fish tissue were in liver samples from carp from Brownlee Reservoir at Burnt River and suckers from the Boise River near Twin Springs. Concentrations of most trace elements were larger in livers than in the sport- fish fillets. However, mercury concentrations were generally larger in the sportfish fillets; they ranged from 0.08 microgram per gram wet weight in yellow perch from C.J. Strike Reservoir to 0.32 microgram per gram wet weight in channel catfish from Brownlee Reservoir at Burnt River. None of the trace-element concentrations in fillets exceeded median international standards or U.S. Food and Drug Administration action levels. Large trace-element concentrations in the upper Snake River Basin were reported in liver samples from suckers from headwater streams, probably a result of historical mining and weathering of metal-rich rocks. Concentrations of most trace elements in the bed-sediment samples were largest in Brownlee Reservoir at Mountain Man Lodge. Concentrations of arsenic, cadmium, chromium, copper, nickel, and zinc in bed sediment from the Mountain Man Lodge site exceeded either the threshold effect level or probable effect level established by the Canadian Government for the protection of benthic life. Arsenic, chromium, copper, and nickel concentrations in bed sediment from Brownlee Reservoir at Burnt River and chromium, copper, and nickel in bed sediment from C.J. Strike Reservoir also exceeded the threshold effect level.

X-ray fluorescence microscopy reveals the role of selenium in spermatogenesis

PubMed Central

Kehr, Sebastian; Malinouski, Mikalai; Finney, Lydia; Vogt, Stefan; Labunskyy, Vyacheslav M.; Kasaikina, Marina V.; Carlson, Bradley A.; Zhou, You; Hatfield, Dolph L.; Gladyshev, Vadim N.

2009-01-01

Selenium (Se) is a trace element with important roles in human health. Several selenoproteins have essential functions in development. However, the cellular and tissue distribution of Se remains largely unknown because of the lack of analytical techniques that image this element with sufficient sensitivity and resolution. Herein, we report that X-ray fluorescence microscopy (XFM) can be used to visualize and quantify the tissue, cellular and subcellular topography of Se. We applied this technique to characterize the role of Se in spermatogenesis and identified a dramatic Se enrichment specifically in late spermatids, a pattern that was not seen in any other elemental maps. This enrichment was due to elevated levels of the mitochondrial form of glutathione peroxidase 4 and was fully dependent on the supplies of Se by Selenoprotein P. High-resolution scans revealed that Se concentrated near the lumen side of elongating spermatids, where structural components of sperm are formed. During spermatogenesis, maximal Se associated with decreased phosphorus, whereas Zn did not change. In sperm, Se was primarily in the midpiece and co-localized with Cu and Fe. XFM allowed quantification of Se in the midpiece (0.8 fg) and head (0.14 fg) of individual sperm cells, revealing the ability of sperm cells to handle the amounts of this element well above its toxic levels. Overall, the use of XFM allowed visualization of tissue and cellular Se and provided important insights in the role of this and other trace elements in spermatogenesis. PMID:19379757

Single Cell Multiplex Protein Measurements through Rare Earth Element Immunolabeling, Laser Capture Microdissection and Inductively Coupled Mass Spectrometry.

PubMed

Liba, Amir; Wanagat, Jonathan

2014-11-01

Complex diseases such as heart disease, stroke, cancer, and aging are the primary causes of death in the US. These diseases cause heterogeneous conditions among cells, conditions that cannot be measured in tissue homogenates and require single cell approaches. Understanding protein levels within tissues is currently assayed using various molecular biology techniques (e.g., Western blots) that rely on milligram to gram quantities of tissue homogenates or immunofluorescent (IF) techniques that are limited by spectral overlap. Tissue homogenate studies lack references to tissue structure and mask signals from individual or rare cellular events. Novel techniques are required to bring protein measurement sensitivity to the single cell level and offer spatiotemporal resolution and scalability. We are developing a novel approach to protein quantification by exploiting the inherently low concentration of rare earth elements (REE) in biological systems. By coupling REE-antibody immunolabeling of cells with laser capture microdissection (LCM) and ICP-QQQ, we are achieving multiplexed protein measurement in histological sections of single cells. This approach will add to evolving single cell techniques and our ability to understand cellular heterogeneity in complex biological systems and diseases.

Regulatory elements in vivo in the promoter of the abscisic acid responsive gene rab17 from maize.

PubMed

Busk, P K; Jensen, A B; Pagès, M

1997-06-01

The rab17 gene from maize is transcribed in late embryonic development and is responsive to abscisic acid and water stress in embryo and vegetative tissues. In vivo footprinting and transient transformation of rab17 were performed in embryos and vegetative tissues to characterize the cis-elements involved in regulation of the gene. By in vivo footprinting, protein binding was observed to nine elements in the promoter, which correspond to five putative ABREs (abscisic acid responsive elements) and four other sequences. The footprints indicated that distinct proteins interact with these elements in the two developmental stages. In transient transformation, six of the elements were important for high level expression of the rab17 promoter in embryos, whereas only three elements were important in leaves. The cis-acting sequences can be divided in embryo-specific, ABA-specific and leaf-specific elements on the basis of protein binding and the ability to confer expression of rab17. We found one positive, new element, called GRA, with the sequence CACTGGCCGCCC. This element was important for transcription in leaves but not in embryos. Two other non-ABRE elements that stimulated transcription from the rab17 promoter resemble previously described abscisic acid and drought-inducible elements. There were differences in protein binding and function of the five ABREs in the rab17 promoter. The possible reasons for these differences are discussed. The in vivo data obtained suggest that an embryo-specific pathway regulates transcription of the rab genes during development, whereas another pathway is responsible for induction in response to ABA and drought in vegetative tissues.

Selenium and the control of thyroid hormone metabolism.

PubMed

Köhrle, Josef

2005-08-01

Thyroid hormone synthesis, metabolism and action require adequate availability of the essential trace elements iodine and selenium, which affect homeostasis of thyroid hormone-dependent metabolic pathways. The three selenocysteine-containing iodothyronine deiodinases constitute a novel gene family. Selenium is retained and deiodinase expression is maintained at almost normal levels in the thyroid gland, the brain and several other endocrine tissues during selenium deficiency, thus guaranteeing adequate local and systemic levels of the active thyroid hormone T(3). Due to their low tissue concentrations and their mRNA SECIS elements deiodinases rank high in the cellular and tissue-specific hierarchy of selenium distribution among various selenoproteins. While systemic selenium status and expression of abundant selenoproteins (glutathione peroxidase or selenoprotein P) is already impaired in patients with cancer, disturbed gastrointestinal resorption, unbalanced nutrition or patients requiring intensive care treatment, selenium-dependent deiodinase function might still be adequate. However, disease-associated alterations in proinflammatory cytokines, growth factors, hormones and pharmaceuticals modulate deiodinase isoenzyme expression independent from altered selenium status and might thus pretend causal relationships between systemic selenium status and altered thyroid hormone metabolism. Limited or inadequate supply of both trace elements, iodine and selenium, leads to complex rearrangements of thyroid hormone metabolism enabling adaptation to unfavorable conditions.

Elemental Levels Analyzed by PIXE in Florida Alligators

NASA Astrophysics Data System (ADS)

Kuharik, J. C.; Kravchenko, I. I.; Dunnam, F. E.; Van Rinsvelt, H. A.; Ross, J. P.

2003-08-01

Unusual and alarming mortality of alligators (Alligator mississippiensis) has been reported from Lake Griffin, Florida, where almost 400 dead alligators have been observed since 1997. In addition, the hatch rate for alligator eggs around Lake Griffin fell below 10% and remains low (30-45%) while the normal hatch rate is typically 80%. Standard diagnostic methods have been ineffective in determining the cause of the phenomenon. Many possibilities have been considered including pollutants, nutrition, and toxic algae. Particle Induced X-ray Emission (PIXE) analysis is highly suitable for investigating concentrations of a wide range of elements in animal tissue. Liver, kidney and spinal cord tissues from healthy and sick alligators have been analyzed by PIXE for elemental content. Initial results showed positive correlation between certain elements and neural impairment and morbidity of alligators in Lake Griffin, but have failed to prove significant.

Distribution of Ca, Fe, Cu and Zn in primary colorectal cancer and secondary colorectal liver metastases

NASA Astrophysics Data System (ADS)

Al-Ebraheem, A.; Mersov, A.; Gurusamy, K.; Farquharson, M. J.

2010-07-01

A microbeam synchrotron X-ray fluorescence (μSRXRF) technique has been used to determine the localization and the relative concentrations of Zn, Cu, Fe and Ca in primary colorectal cancer and secondary colorectal liver metastases. 24 colon and 23 liver samples were examined, all of which were formalin fixed tissues arranged as microarrays of 1.0 mm diameter and 10 μm thickness. The distribution of these metals was compared with light transmission images of adjacent sections that were H and E stained to reveal the location of the cancer cells. Histological details were provided for each sample which enable concentrations of all elements in different tissue types to be compared. In the case of liver, significant differences have been found for all elements when comparing tumour, normal, necrotic, fibrotic, and blood vessel tissues (Kruskal Wallis Test, P<0.0001). The concentrations of all elements have also been found to be significantly different among tumour, necrotic, fibrotic, and mucin tissues in the colon samples (Kruskal Wallis Test, P<0.0001). The concentrations of all elements have been compared between primary colorectal samples and colorectal liver metastases. Concentration of Zn, Cu, Fe and Ca are higher in all types of liver tissues compared to those in the colon tissues. Comparing liver tumour and colon tumour samples, significant differences have been found for all elements (Mann Whitney, P<0.0001). For necrotic tissues, significant increase has been found for Zn, Ca, Cu and Fe (Mann Whitney, P<0.0001 for Fe and Zn, 0.014 for Ca, and 0.001 for Cu). The liver fibrotic levels of Zn, Ca, Cu and Fe were higher than the fibrotic colon areas (independent T test, P=0.007 for Zn and Mann Whitney test P<0.0001 for Cu, Fe and Ca). For the blood vessel tissue, the analysis revealed that the difference was only significant for Fe ( P=0.009) from independent T test.

Nuclear microscopy in Alzheimer's disease

NASA Astrophysics Data System (ADS)

Makjanic, Jagoda; Watt, Frank

1999-04-01

The elemental composition of the two types of brain lesions which characterise Alzheimer's disease (AD) has been the subject of intense scrutiny over the last decade, ever since it was proposed that inorganic trace elements, particularly aluminium, might be implicated in the pathogenesis of the disease. The major evidence for this involvement was the detection of aluminium in the characteristic lesions of the AD brain; neuritic plaques and neurofibrillary tangles (NFTs). Using the powerful combination of Particle-Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM), it is possible to image and analyse structures in brain sections without recourse to chemical staining. Previous results on elemental composition of senile plaques indicated the absence of aluminium at the 15 parts per million level. We have more recently focused on the analysis of neurofibrillary tangles (NFTs), destructive structural defects within neurons. Imaging and analysis of neurons in brain tissue presented a greater challenge due to the small dimensional size compared with the plaques. We describe the methodology and the results of imaging and analysing neurons in brain tissue sections using Nuclear Microscopy. Our results show that aluminium is not present in either neurons or surrounding tissue in unstained sections at the 20 ppm level, but can be observed in stained sections. We also report elemental concentrations showing significant elevations of phosphorus, sulphur, chlorine, iron and zinc.

Alu-derived cis-element regulates tumorigenesis-dependent gastric expression of GASDERMIN B (GSDMB).

PubMed

Komiyama, Hiromitsu; Aoki, Aya; Tanaka, Shigekazu; Maekawa, Hiroshi; Kato, Yoriko; Wada, Ryo; Maekawa, Takeo; Tamura, Masaru; Shiroishi, Toshihiko

2010-02-01

GASDERMIN B (GSDMB) belongs to the novel gene family GASDERMIN (GSDM). All GSDM family members are located in amplicons, genomic regions often amplified during cancer development. Given that GSDMB is highly expressed in cancerous cells and the locus resides in an amplicon, GSDMB may be involved in cancer development and/or progression. However, only limited information is available on GSDMB expression in tissues, normal and cancerous, from cancer patients. Furthermore, the molecular mechanisms that regulate GSDMB expression in gastric tissues are poorly understood. We investigated the spatiotemporal expression patterns of GSDMB in gastric cancer patients and the 5' regulatory sequences upstream of GSDMB. GSDMB was not expressed in the majority of normal gastric-tissue samples, and the expression level was very low in the few normal samples with GSDMB expression. Most pre-cancer samples showed moderate GSDMB expression, and most cancerous samples showed augmented GSDMB expression. Analysis of genome sequences revealed that an Alu element resides in the 5' region upstream of GSDMB. Reporter assays using intact, deleted, and mutated Alu elements clearly showed that this Alu element positively regulates GSDMB expression and that a putative IKZF binding motif in this element is crucial to upregulate GSDMB expression.

Stress distribution in fixed-partial prosthesis and peri-implant bone tissue with different framework materials and vertical misfit levels: a three-dimensional finite element analysis.

PubMed

Bacchi, Ataís; Consani, Rafael L X; Mesquita, Marcelo F; dos Santos, Mateus B F

2013-09-01

The purpose of this study was to evaluate the influence of superstructure material and vertical misfits on the stresses created in an implant-supported partial prosthesis. A three-dimensional (3-D) finite element model was prepared based on common clinical data. The posterior part of a severely resorbed jaw with two osseointegrated implants at the second premolar and second molar regions was modeled using specific modeling software (SolidWorks 2010). Finite element models were created by importing the solid model into mechanical simulation software (ANSYS Workbench 11). The models were divided into groups according to the prosthesis framework material (type IV gold alloy, silver-palladium alloy, commercially pure titanium, cobalt-chromium alloy, or zirconia) and vertical misfit level (10 µm, 50 µm, and 100 µm) created at one implant-prosthesis interface. The gap of the vertical misfit was set to be closed and the stress values were measured in the framework, porcelain veneer, retention screw, and bone tissue. Stiffer materials led to higher stress concentration in the framework and increased stress values in the retention screw, while in the same circumstances, the porcelain veneer showed lower stress values, and there was no significant difference in stress in the peri-implant bone tissue. A considerable increase in stress concentration was observed in all the structures evaluated within the misfit amplification. The framework material influenced the stress concentration in the prosthetic structures and retention screw, but not that in bone tissue. All the structures were significantly influenced by the increase in the misfit levels.

Levels of chemical contaminants in nonoccupationally exposed U. S. residents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holleman, J.W.; Hammons, A.S.

1978-08-01

Data are presented on the levels of all chemical contaminants resulting from environmental pollution which have been found in human tissues including blood, urine, breast milk, and tissue samples obtained at autopsy. Most data results from specific surveys to determine health hazards. The roles of trace elements and recognition of the need to determine baseline levels of chemicals introduced into the environment are factors which have motivated surveys by individual investigators. Thus, most data on chemicals in human tissues record levels of pesticides (e.g., DDT and metabolites), levels of trace metals such as lead, cadmium, and mercury, or levels ofmore » nutritionally essential elements such as zinc, copper, manganese, and fluoride. Data available on iron and calcium are not presented as their presence in the environment is generally not considered hazardous. Data on several uncommon chemicals, such as indium and ytterbium, are included basically as items of interest and to further document their presence in healthy individuals. Baseline data were presented where available to provide perspective as to chemical levels which might be expected under conditions where exposure could be considered normal or not directly related to a pollutant source. Nearly 600 cited surveys or investigations, most of which were reported within the past decade, are listed. Ninety-four different chemical contaminants, primarily trace metals and organochlorine pesticides, are reported. It is estimated that over 75% of the data published during the past 30 years on chemical contaminants derived from environmental pollution and found in human tissue in the United States are represented in this report.« less

Expression of small cytoplasmic transcripts of the rat identifier element in vivo and in cultured cells.

PubMed Central

McKinnon, R D; Danielson, P; Brow, M A; Bloom, F E; Sutcliffe, J G

1987-01-01

We examined the level of expression of small RNA transcripts hybridizing to a rodent repetitive DNA element, the identifier (ID) sequence, in a variety of cell types in vivo and in cultured mammalian cells. A 160-nucleotide (160n) cytoplasmic poly(A)+ RNA (BC1) appeared in late embryonic and early postnatal rat brain development, was enriched in the cerebral cortex, and appeared to be restricted to neural tissue and the anterior pituitary gland. A 110n RNA (BC2) was specifically enriched in brain, especially the postnatal cortex, but was detectable at low levels in peripheral tissues. A third, related 75n poly(A)- RNA (T3) was found in rat brain and at lower levels in peripheral tissues but was very abundant in the testes. The BC RNAs were found in a variety of rat cell lines, and their level of expression was dependent upon cell culture conditions. A rat ID probe detected BC-like RNAs in mouse brain but not liver and detected a 200n RNA in monkey brain but not liver at lower hybridization stringencies. These RNAs were expressed by mouse and primate cell lines. Thus, tissue-specific expression of small ID-sequence-related transcripts is conserved among mammals, but the tight regulation found in vivo is lost by cells in culture. Images PMID:2439903

Emerging Patterns in the Distribution of Trace Elements in Ovarian, Invasive and In-Situ Breast Cancer

NASA Astrophysics Data System (ADS)

Al-Ebraheem, A.; Dao, E.; Geraki, K.; Farquharson, M. J.

2014-04-01

Breast cancer is the most common cancer and ovarian cancer is the 8th most common cancer affecting women worldwide. This study highlights the changes of trace element levels accompanied by the progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) of the breast, using micro probe Synchrotron Radiation X-ray Fluorescence (μSRXRF). The average values for the increase in Ca, Fe and Zn in tumour regions with respect to surrounding regions for the DCIS samples were significantly higher compared to the increase in the IDC samples (P <0.01).This study was also carried out to find a connection between ovarian cancer and breast cancer with respect to the cellular distribution of Ca, Cu, Fe, and Zn. For IDC, DCIS and ovarian cases, the statistical analysis reveals a significant increase in the levels of Ca, Cu and Zn concentrations in cancer tissue when compared to the normal surrounding tissue. For Fe, the differences between tumour regions with respect to surrounding regions were found to be not significant in IDC and ovarian cases. In DCIS cases, the results reveal a significant increase in the levels of Fe in cancer tissue when compared to the surrounding normal breast tissue (P <0.01).

The role of acoustic nonlinearity in tissue heating behind a rib cage using a high-intensity focused ultrasound phased array

NASA Astrophysics Data System (ADS)

Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

2013-04-01

The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high-intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field, and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low-power sonications. Intensity levels at the face of the array elements that corresponded to the formation of high-amplitude shock fronts in the focal region were determined as 10 W cm-2 in the free field in water and 40 W cm-2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue.

The role of acoustic nonlinearity in tissue heating behind the rib cage using high intensity focused ultrasound phased array

PubMed Central

Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

2013-01-01

The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path, and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low power sonications. Intensity levels at the face of the array elements that corresponded to formation of high amplitude shock fronts in the focal region were determined as 10 W·cm−2 in the free field in water and 40 W·cm−2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue. PMID:23528338

Design of chimeric expression elements that confer high-level gene activity in chromoplasts.

PubMed

Caroca, Rodrigo; Howell, Katharine A; Hasse, Claudia; Ruf, Stephanie; Bock, Ralph

2013-02-01

Non-green plastids, such as chromoplasts, generally have much lower activity of gene expression than chloroplasts in photosynthetically active tissues. Suppression of plastid genes in non-green tissues occurs through a complex interplay of transcriptional and translational control, with the contribution of regulation of transcript abundance versus translational activity being highly variable between genes. Here, we have investigated whether the low expression of the plastid genome in chromoplasts results from inherent limitations in gene expression capacity, or can be overcome by designing appropriate combinations of promoters and translation initiation signals in the 5' untranslated region (5'-UTR). We constructed chimeric expression elements that combine promoters and 5'-UTRs from plastid genes, which are suppressed during chloroplast-to-chromoplast conversion in Solanum lycopersicum (tomato) fruit ripening, either just at the translational level or just at the level of mRNA accumulation. These chimeric expression elements were introduced into the tomato plastid genome by stable chloroplast transformation. We report the identification of promoter-UTR combinations that confer high-level gene expression in chromoplasts of ripe tomato fruits, resulting in the accumulation of reporter protein GFP to up to 1% of total cellular protein. Our work demonstrates that non-green plastids are capable of expressing genes to high levels. Moreover, the chimeric cis-elements for chromoplasts developed here are widely applicable in basic and applied research using transplastomic methods. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

Biominerals- hierarchical nanocomposites: the example of bone

PubMed Central

Beniash, Elia

2010-01-01

Many organisms incorporate inorganic solids in their tissues to enhance their functional, primarily mechanical, properties. These mineralized tissues, also called biominerals, are unique organo-mineral nanocomposites, organized at several hierarchical levels, from nano- to macroscale. Unlike man made composite materials, which often are simple physical blends of their components, the organic and inorganic phases in biominerals interface at the molecular level. Although these tissues are made of relatively weak components at ambient conditions, their hierarchical structural organization and intimate interactions between different elements lead to superior mechanical properties. Understanding basic principles of formation, structure and functional properties of these tissues might lead to novel bioinspired strategies for material design and better treatments for diseases of the mineralized tissues. This review focuses on general principles of structural organization, formation and functional properties of biominerals on the example the bone tissues. PMID:20827739

A probable risk factor of female breast cancer: study on benign and malignant breast tissue samples.

PubMed

Rehman, Sohaila; Husnain, Syed M

2014-01-01

The study reports enhanced Fe, Cu, and Zn contents in breast tissues, a probable risk factor of breast cancer in females. Forty-one formalin-fixed breast tissues were analyzed using atomic absorption spectrophotometry. Twenty malignant, six adjacent to malignant and 15 benign tissues samples were investigated. The malignant tissues samples were of grade 11 and type invasive ductal carcinoma. The quantitative comparison between the elemental levels measured in the two types of specimen (benign and malignant) tissues (removed after surgery) suggests significant elevation of these metals (Fe, Cu, and Zn) in the malignant tissue. The specimens were collected just after mastectomy of women aged 19 to 59 years from the hospitals of Islamabad and Rawalpindi, Pakistan. Most of the patients belong to urban areas of Pakistan. Findings of study depict that these elements have a promising role in the initiation and development of carcinoma as consistent pattern of elevation for Fe, Cu, and Zn was observed. The results showed the excessive accumulation of Fe (229 ± 121 mg/L) in malignant breast tissue samples of patients (p < 0.05) to that in benign tissues samples (49.1 ± 11.4 mg/L). Findings indicated that excess accumulation of iron in malignant tissues can be a risk factor of breast cancer. In order to validate our method of analysis, certified reference material muscle tissue lyophilized (IAEA) MA-M-2/TM was analyzed for metal studied. Determined concentrations were quite in good agreement with certified levels. Asymmetric concentration distribution for Fe, Cu, and Zn was observed in both malignant and benign tissue samples.

Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers, 1992-93

USGS Publications Warehouse

Ruhl, P.M.; Smith, K.E.

1996-01-01

The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers were analyzed to obtain information about the occurrence and distribution of trace element contaminants in the Albemarle-Pamlico Drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. All but 3 of the 22 trace elements that were analyzed were detected. Although all 10 of the U.S. Environmental Protection Agency (U.S. EPA) priority pollutants were detected in the tissues sampled, they were present in relatively low concentrations. Concentrations of U.S. EPA priority pollutants in Asiatic clams collected in the Albemarle-Pamlico Drainage Basin are similar to concentrations observed in other NAWQA study units in the southeastern United States. Mercury (a U.S. EPA priority pollutant) was widely detected, being present in 29 of 30 tissue samples, but concentrations did not exceed the FDA action level for mercury of a risk-based screening value for the general public. Mercury concentrations in Asiatic clams were similar to concentrations in other NAWQA study areas in the Southeast.

Coal fly ash basins as an attractive nuisance to birds: parental provisioning exposes nestlings to harmful trace elements.

PubMed

Bryan, A L; Hopkins, W A; Parikh, J H; Jackson, B P; Unrine, J M

2012-02-01

Birds attracted to nest around coal ash settling basins may expose their young to contaminants by provisioning them with contaminated food. Diet and tissues of Common Grackle (Quiscalus quiscala) nestlings were analyzed for trace elements to determine if nestlings were accumulating elements via dietary exposure and if feather growth limits elemental accumulation in other tissues. Arsenic, cadmium, and selenium concentrations in ash basin diets were 5× higher than reference diets. Arsenic, cadmium, and selenium concentrations were elevated in feather, liver, and carcass, but only liver Se concentrations approached levels of concern. Approximately 15% of the total body burden of Se, As, and Cd was sequestered in feathers of older (>5 days) nestlings, whereas only 1% of the total body burden of Sr was sequestered in feathers. Feather concentrations of only three elements (As, Se, and Sr) were correlated with liver concentrations, indicating their value as non-lethal indicators of exposure. Copyright © 2011 Elsevier Ltd. All rights reserved.

AMP deaminase histochemical activity and immunofluorescent isozyme localization in rat skeletal muscle

NASA Technical Reports Server (NTRS)

Thompson, J. L.; Sabina, R. L.; Ogasawara, N.; Riley, D. A.

1992-01-01

The cellular distribution of AMP deaminase (AMPda) isozymes was documented for rat soleus and plantaris muscles, utilizing immunofluorescence microscopy and immunoprecipitation methods. AMPda is a ubiquitous enzyme existing as three distinct isozymes, A, B and C, which were initially purified from skeletal muscle, liver (and kidney), and heart, respectively. AMPda-A is primarily concentrated subsarcolemmally and intermyofibrillarly within muscle cells, while isozymes B and C are concentrated within non-myofiber elements of muscle tissue. AMPda-B is principally associated with connective tissues surrounding neural elements and the muscle spindle capsule, and AMPda-C is predominantly associated with circulatory elements, such as arterial and venous walls, capillary endothelium, and red blood cells. These specific localizations, combined with documented differences in kinetic properties, suggest multiple functional roles for the AMPda isozymes or temporal segregation of similar AMPda functions. Linkage of the AMPda substrate with adenosine production pathways at the AMP level and the localization of isozyme-C in vascular tissue suggest a regulatory role in the microcirculation.

Effect of Intestinal Tapeworm Clestobothrium crassiceps on Concentrations of Toxic Elements and Selenium in European Hake Merluccius merluccius from the Gulf of Lion (Northwestern Mediterranean Sea).

PubMed

Torres, Jordi; Eira, Catarina; Miquel, Jordi; Ferrer-Maza, Dolors; Delgado, Eulàlia; Casadevall, Margarida

2015-10-28

The capacity for heavy metal bioaccumulation by some fish parasites has been demonstrated, and their contribution to decreasing metal concentrations in tissues of parasitized fish has been hypothesized. The present study evaluated the effect of the cestode Clestobothrium crassiceps on the accumulation of trace elements in 30 European hake, Merluccius merluccius, in Spain (half of them infested by C. crassiceps). Tissue samples from all M. merluccius and specimens of C. crassiceps from the infected hakes were collected and stored until element analysis by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic, mercury, and selenium were generally present in lower levels in the cestode than in all hake tissues. The mean value of the muscular Se:Hg molar ratio in the infested subsample was higher than that in hakes without cestodes. Values indicate that the edible part of infested hakes presents a lower amount of Cd and Pb in relation to noninfested hakes.

Identification of cis-elements conferring high levels of gene expression in non-green plastids.

PubMed

Zhang, Jiang; Ruf, Stephanie; Hasse, Claudia; Childs, Liam; Scharff, Lars B; Bock, Ralph

2012-10-01

Although our knowledge about the mechanisms of gene expression in chloroplasts has increased substantially over the past decades, next to nothing is known about the signals and factors that govern expression of the plastid genome in non-green tissues. Here we report the development of a quantitative method suitable for determining the activity of cis-acting elements for gene expression in non-green plastids. The in vivo assay is based on stable transformation of the plastid genome and the discovery that root length upon seedling growth in the presence of the plastid translational inhibitor kanamycin is directly proportional to the expression strength of the resistance gene nptII in transgenic tobacco plastids. By testing various combinations of promoters and translation initiation signals, we have used this experimental system to identify cis-elements that are highly active in non-green plastids. Surprisingly, heterologous expression elements from maize plastids were significantly more efficient in conferring high expression levels in root plastids than homologous expression elements from tobacco. Our work has established a quantitative method for characterization of gene expression in non-green plastid types, and has led to identification of cis-elements for efficient plastid transgene expression in non-green tissues, which are valuable tools for future transplastomic studies in basic and applied research. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

Trace elemental analysis in cancer-afflicted tissues of penis and testis by PIXE technique

NASA Astrophysics Data System (ADS)

Naga Raju, G. J.; John Charles, M.; Bhuloka Reddy, S.; Sarita, P.; Seetharami Reddy, B.; Rama Lakshmi, P. V. B.; Vijayan, V.

2005-04-01

PIXE technique was employed to estimate the trace elemental concentrations in the biological samples of cancerous penis and testis. A 3 MeV proton beam was employed to excite the samples. From the present results it can be seen that the concentrations of Cl, Fe and Co are lower in the cancerous tissue of the penis when compared with those in normal tissue while the concentrations of Cu, Zn and As are relatively higher. The concentrations of K, Ca, Ti, Cr, Mn, Br, Sr and Pb are in agreement within standard deviations in both cancerous and normal tissues. In the cancerous tissue of testis, the concentrations of K, Cr and Cu are higher while the concentrations of Fe, Co and Zn are lower when compared to those in normal tissue of testis. The concentrations of Cl, Ca, Ti and Mn are in agreement in both cancerous and normal tissues of testis. The higher levels of Cu lead to the development of tumor. Our results also support the underlying hypothesis of an anticopper, antiangiogenic approach to cancer therapy. The Cu/Zn ratios of both penis and testis were higher in cancer tissues compared to that of normal.

Accumulation of rare earth elements in human bone within the lifespan.

PubMed

Zaichick, Sofia; Zaichick, Vladimir; Karandashev, Vasilii; Nosenko, Sergey

2011-02-01

For the first time, the contents of rare earth elements (REEs) in a rib bone of a healthy human were determined. The mean value of the contents of Ce, Dy, Er, Gd, La, Nd, Pr, Sm, Tb, and Yb (10 elements out of 17 total REEs), as well as the upper limit of means for Ho, Lu, Tm, and Y (4 elements) were measured in the rib bone tissue of 38 females and 42 males (15 to 55 years old) using inductively coupled plasma mass spectrometry (ICP-MS). We found age-related accumulation of REEs in the bone tissue of healthy individuals who lived in a non-industrial region. It was calculated that during a lifespan the content of REEs in a skeleton of non-industrial region residents may increase by one to two orders of magnitude. Using our results as indicative normal values and published data we estimated relative Gd accumulation in the bone tissue of patients according to magnetic resonance imaging with contrast agent and La accumulation in the bone tissue of patients receiving hemodialysis after treatment with lanthanum carbonate as a phosphate binder. It was shown that after such procedures contents of Gd and La in the bone tissue of patients are two to three orders of magnitude higher than normal levels. In our opinion, REEs incorporation may affect bone quality and health similar to other potentially toxic trace metals. The impact of elevated REEs content on bone physiology, biochemistry and morphology requires further investigation.

Expression analysis of metallothioneins and mineral contents in tomato (Lycopersicon esculentum) under heavy metal stress.

PubMed

Kısa, Dursun; Öztürk, Lokman; Doker, Serhat; Gökçe, İsa

2017-04-01

Heavy metals are considered to be the most important pollutants in the contamination of soils; they adversely affect plant growth and development and cause some physiological and molecular changes. The contamination of agricultural soils by heavy metals has changed the mineral element content of vegetables. Plant metallothioneins (MTs) are thought to have the functional role in heavy metal homeostasis, and they are used as the biomarkers for evaluating environmental pollution. We aimed to evaluate the expression of MT isoforms (MT1, 2, 3 and 4) and some mineral element composition of tomato roots, leaves and fruits exposed to copper and lead. Heavy metal applications increased MT1 and MT2 gene expressions compared to the control in the tissues of tomato. The highest level of MT1 and MT2 transcripts was found in roots and leaves, respectively. The expression of MT3 is induced in roots, leaves and fruits except for Pb treatment in roots. MT4 expression increased in fruits; however, other tissues did not show a clear change. Our results indicated that Cu content was higher than Pb in all tissues of tomato. The lower doses of Cu (10 ppm) increased the content of Mg, Fe, Ca and Mn in roots. Pb generally increased the level of minerals in leaves and fruits, but it decreased Mg, Mn and Fe contents in roots. Both heavy metals not only moved to aerial parts but also caused alterations to mineral element levels. These results show that MT transcripts are regulated by Cu and Pb, and expression pattern changes to MT isoforms and tissue types. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue.

PubMed

Pemmer, B; Roschger, A; Wastl, A; Hofstaetter, J G; Wobrauschek, P; Simon, R; Thaler, H W; Roschger, P; Klaushofer, K; Streli, C

2013-11-01

Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radiation induced micro X-ray fluorescence analysis (SR μ-XRF) in combination with quantitative backscattered electron imaging (qBEI) to determine the distribution and accumulation of Zn, Sr, and Pb in human bone tissue. Fourteen human bone samples (10 femoral necks and 4 femoral heads) from individuals with osteoporotic femoral neck fractures as well as from healthy individuals were analyzed. Fluorescence intensity maps were matched with BE images and correlated with calcium (Ca) content. We found that Zn and Pb had significantly increased levels in the cement lines of all samples compared to the surrounding mineralized bone matrix. Pb and Sr levels were found to be correlated with the degree of mineralization. Interestingly, Zn intensities had no correlation with Ca levels. We have shown for the first time that there is a differential accumulation of the trace elements Zn, Pb and Sr in BSUs of human bone indicating different mechanisms of accumulation. © 2013. Published by Elsevier Inc. All rights reserved.

Tooth Eruption Results from Bone Remodelling Driven by Bite Forces Sensed by Soft Tissue Dental Follicles: A Finite Element Analysis

PubMed Central

Sarrafpour, Babak; Swain, Michael; Li, Qing; Zoellner, Hans

2013-01-01

Intermittent tongue, lip and cheek forces influence precise tooth position, so we here examine the possibility that tissue remodelling driven by functional bite-force-induced jaw-strain accounts for tooth eruption. Notably, although a separate true ‘eruptive force’ is widely assumed, there is little direct evidence for such a force. We constructed a three dimensional finite element model from axial computerized tomography of an 8 year old child mandible containing 12 erupted and 8 unerupted teeth. Tissues modelled included: cortical bone, cancellous bone, soft tissue dental follicle, periodontal ligament, enamel, dentine, pulp and articular cartilage. Strain and hydrostatic stress during incisive and unilateral molar bite force were modelled, with force applied via medial and lateral pterygoid, temporalis, masseter and digastric muscles. Strain was maximal in the soft tissue follicle as opposed to surrounding bone, consistent with follicle as an effective mechanosensor. Initial numerical analysis of dental follicle soft tissue overlying crowns and beneath the roots of unerupted teeth was of volume and hydrostatic stress. To numerically evaluate biological significance of differing hydrostatic stress levels normalized for variable finite element volume, ‘biological response units’ in Nmm were defined and calculated by multiplication of hydrostatic stress and volume for each finite element. Graphical representations revealed similar overall responses for individual teeth regardless if incisive or right molar bite force was studied. There was general compression in the soft tissues over crowns of most unerupted teeth, and general tension in the soft tissues beneath roots. Not conforming to this pattern were the unerupted second molars, which do not erupt at this developmental stage. Data support a new hypothesis for tooth eruption, in which the follicular soft tissues detect bite-force-induced bone-strain, and direct bone remodelling at the inner surface of the surrounding bony crypt, with the effect of enabling tooth eruption into the mouth. PMID:23554928

Tooth eruption results from bone remodelling driven by bite forces sensed by soft tissue dental follicles: a finite element analysis.

PubMed

Sarrafpour, Babak; Swain, Michael; Li, Qing; Zoellner, Hans

2013-01-01

Intermittent tongue, lip and cheek forces influence precise tooth position, so we here examine the possibility that tissue remodelling driven by functional bite-force-induced jaw-strain accounts for tooth eruption. Notably, although a separate true 'eruptive force' is widely assumed, there is little direct evidence for such a force. We constructed a three dimensional finite element model from axial computerized tomography of an 8 year old child mandible containing 12 erupted and 8 unerupted teeth. Tissues modelled included: cortical bone, cancellous bone, soft tissue dental follicle, periodontal ligament, enamel, dentine, pulp and articular cartilage. Strain and hydrostatic stress during incisive and unilateral molar bite force were modelled, with force applied via medial and lateral pterygoid, temporalis, masseter and digastric muscles. Strain was maximal in the soft tissue follicle as opposed to surrounding bone, consistent with follicle as an effective mechanosensor. Initial numerical analysis of dental follicle soft tissue overlying crowns and beneath the roots of unerupted teeth was of volume and hydrostatic stress. To numerically evaluate biological significance of differing hydrostatic stress levels normalized for variable finite element volume, 'biological response units' in Nmm were defined and calculated by multiplication of hydrostatic stress and volume for each finite element. Graphical representations revealed similar overall responses for individual teeth regardless if incisive or right molar bite force was studied. There was general compression in the soft tissues over crowns of most unerupted teeth, and general tension in the soft tissues beneath roots. Not conforming to this pattern were the unerupted second molars, which do not erupt at this developmental stage. Data support a new hypothesis for tooth eruption, in which the follicular soft tissues detect bite-force-induced bone-strain, and direct bone remodelling at the inner surface of the surrounding bony crypt, with the effect of enabling tooth eruption into the mouth.

Sport- and sample-specific features of trace elements in adolescent female field hockey players and fencers.

PubMed

Nabatov, Alexey A; Troegubova, Natalya A; Gilmutdinov, Ruslan R; Sereda, Andrey P; Samoilov, Alexander S; Rylova, Natalya V

2017-09-01

Active physical exercises and growth are associated with mineral imbalances in young athletes. The purpose of this study was to examine the impact of sport-related factors on tissue mineral status in adolescent female athletes. Saliva and hair samples were used for the analysis of immediate and more permanent tissue mineral status, respectively. Samples taken from a control non-athletic female group and two groups of female athletes (field hockey and fencing) were analyzed for seven essential minerals: calcium, chromium, iron, potassium, magnesium, selenium and zinc. Inductively-coupled plasma mass spectrometry was used for the quantification of elements having very low concentration range in samples (Se, Cr and Zn) whereas inductively coupled plasma optical emission spectrometry was used for quantification of more ubiquitous elements (Mg, К, Са, Fe). The obtained results for athletic groups were compared with control. Female athletes had increased levels of selenium in both saliva and hair as well as chromium in saliva. Field hockey players had the higher level of zinc in hair whereas fencers had the lower levels of salivary calcium. Strong negative correlation between potassium levels in saliva and hair was identified. Iron and magnesium did not differ between the studied groups. In conclusion, novel sport-specific features of chromium tissue levels in female athletes were found. The studied sport disciplines have different impact on the distribution of osteoporosis-related minerals (calcium and zinc). Our finding can help in the development of osteoporosis preventive trainings and in the proper nutrient supplementation to correct mineral imbalances in female athletes. Copyright © 2016 Elsevier GmbH. All rights reserved.

Modeling the Morphogenesis of Epidermal Tissues on the Surface of a 3D Last

NASA Astrophysics Data System (ADS)

McCleery, W. Tyler; Crews, Sarah M.; Mashburn, David N.; Veldhuis, Jim; Brodland, G. Wayne; Hutson, M. Shane

2014-03-01

Embryogenesis in the fruit fly Drosophila melanogaster is coordinated by the interaction of cells in adjacent tissues. For some events of embryogenesis, e.g., dorsal closure, two-dimensional models have been sufficient to elucidate the relevant cell and tissue mechanics. Here, we describe a new three-dimensional cell-level finite element model for investigating germ band retraction - a morphogenetic event where one epidermal tissue, the germ band, initially wraps around the posterior end of the ellipsoidal embryo. This tissue then retracts with a mechanical assist from contraction of cells in a second epidermal tissue, the amnioserosa. To speed simulation run times and focus on the relevant tissues, we only model epidermal tissue interactions. Epidermal cells are defined as polygons constrained to lie on the surface of the ellipsoidal last, but have adjustable parameters such as edge tensions and cell pressures. Tissue movements are simulated by balancing these dynamic cell-level forces with viscous resistance and allowing cells to exchange neighbors. Our choice of modeling parameters is informed by in vivo measurements of cell-level forces using laser microsurgery. We use this model to investigate the multicellular stress fields in normal and aberrant development.

Emergent cell and tissue dynamics from subcellular modeling of active biomechanical processes

NASA Astrophysics Data System (ADS)

Sandersius, S. A.; Weijer, C. J.; Newman, T. J.

2011-08-01

Cells and the tissues they form are not passive material bodies. Cells change their behavior in response to external biochemical and biomechanical cues. Behavioral changes, such as morphological deformation, proliferation and migration, are striking in many multicellular processes such as morphogenesis, wound healing and cancer progression. Cell-based modeling of these phenomena requires algorithms that can capture active cell behavior and their emergent tissue-level phenotypes. In this paper, we report on extensions of the subcellular element model to model active biomechanical subcellular processes. These processes lead to emergent cell and tissue level phenotypes at larger scales, including (i) adaptive shape deformations in cells responding to slow stretching, (ii) viscous flow of embryonic tissues, and (iii) streaming patterns of chemotactic cells in epithelial-like sheets. In each case, we connect our simulation results to recent experiments.

Micromechanical analysis of volumetric growth in the context of open systems thermodynamics and configurational mechanics. Application to tumor growth

NASA Astrophysics Data System (ADS)

Ganghoffer, J. F.; Boubaker, M. B.

2017-03-01

We adopt in this paper the physically and micromechanically motivated point of view that growth (resp. resorption) occurs as the expansion (resp. contraction) of initially small tissue elements distributed within a host surrounding matrix, due to the interfacial motion of their boundary. The interface motion is controlled by the availability of nutrients and mechanical driving forces resulting from the internal stresses that built in during the growth. A general extremum principle of the zero potential for open systems witnessing a change of their mass due to the diffusion of nutrients is constructed, considering the framework of open systems thermodynamics. We postulate that the shape of the tissue element evolves in such a way as to minimize the zero potential among all possible admissible shapes of the growing tissue elements. The resulting driving force for the motion of the interface sets a surface growth models at the scale of the growing tissue elements, and is conjugated to a driving force identified as the interfacial jump of the normal component of an energy momentum tensor, in line with Hadamard's structure theorem. The balance laws associated with volumetric growth at the mesoscopic level result as the averaging of surface growth mechanisms occurring at the microscopic scale of the growing tissue elements. The average kinematics has been formulated in terms of the effective growth velocity gradient and elastic rate of deformation tensor, both functions of time. This formalism is exemplified by the simulation of the avascular growth of multicell spheroids in the presence of diffusion of nutrients, showing the respective influence of mechanical and chemical driving forces in relation to generation of internal stresses.

Contaminant levels in fish tissue from San Francisco Bay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fairey, R.; Taberski, K.

1995-12-31

Edible fish species were collected from thirteen locations throughout San Francisco Bay, during the spring of 1994, for determination of contaminants levels in muscle tissue. Species collected included white croaker, surfperch, leopard and brown smoothhound sharks, striped bass, white sturgeon and halibut Sixty six composite tissue samples were analyzed for the presence of PAHs, PCBs, pesticides, trace elements and dioxin/furans. The US EPA approach to assessing chemical contaminant data for fish tissue consumption was used for identifying the primary chemicals of concern. Six chemicals or chemical groups were found to exceed screening levels established using the US EPA approach. PCBsmore » (as total Aroclors) exceeded the screening level of 3 ppb in all sixty six tissue samples, with the highest concentrations (638 ppb) found near San Francisco`s industrial areas. Mercury was elevated (> 0.14 ppm) in forty of the sixty-six samples with the highest levels (1.26 ppm) occurring in shark muscle tissues. Concentrations of the organochlorine pesticides dieldrin, total chlordanes and total DDTs exceeded screening levels in a number of samples. Dioxin/furans (as TEQs) were elevated (above 0.15 ppt) in 16 of the 19 samples analyzed. Fish with high lipid content (croaker and surfperch) in their muscle tissue generally exhibited higher contaminant levels while fish with low lipid levels (halibut and shark) exhibited lower organic contaminant levels. Tissue samples taken from North Bay stations most often exhibited high levels of chemical contamination. The California Office of Health Hazard Assessment is currently evaluating the results of this study and has issued an interim Health Advisory concerning the human consumption of fish tissue from San Francisco Bay.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bercovitz, K.; Alikhan, M.A.

The amount of toxic and non-toxic elements assimilated by primary consumers from their environment depends as much on the form, as on concentration of these elements in the food. In superficially contaminated sites, the majority of elements detected in plant material are present as a blanket deposit of fine particles on leaf surfaces, and these are easily removed as the consumed material passes through the alimentary canal. In contrast, trace metals stored in the plant tissue are not readily available as they have been taken up via roots and are firmly bound within the plant tissue. Earlier studies have shownmore » that mean concentrations of magnesium (Mg) and manganese (Mn) in whole woodlice are correlated with levels in their diet. Both metals are regulated by terrestrial isopods during their intermoult- and moult-cycles. The present study provides information on the regulation of Mg and Mn tissue concentrations during forced fasting in adult, intermoult male and female Porcellio spinicornis Say (Porcellionidae, Isopoda). Mg, the principal cation in the soft tissues is a well known activator of many enzymes of the glycolytic systems. Mn, on the other hand, plays a special role in digestive and catabolic processes.« less

NOTE: Do acupuncture points exist?

NASA Astrophysics Data System (ADS)

Yan, Xiaohui; Zhang, Xinyi; Liu, Chenglin; Dang, Ruishan; Huang, Yuying; He, Wei; Ding, Guanghong

2009-05-01

We used synchrotron x-ray fluorescence analysis to probe the distribution of four chemical elements in and around acupuncture points, two located in the forearm and two in the lower leg. Three of the four acupuncture points showed significantly elevated concentrations of elements Ca, Fe, Cu and Zn in relation to levels in the surrounding tissue, with similar elevation ratios for Cu and Fe. The mapped distribution of these elements implies that each acupuncture point seems to be elliptical with the long axis along the meridian.

Finite element methods for the biomechanics of soft hydrated tissues: nonlinear analysis and adaptive control of meshes.

PubMed

Spilker, R L; de Almeida, E S; Donzelli, P S

1992-01-01

This chapter addresses computationally demanding numerical formulations in the biomechanics of soft tissues. The theory of mixtures can be used to represent soft hydrated tissues in the human musculoskeletal system as a two-phase continuum consisting of an incompressible solid phase (collagen and proteoglycan) and an incompressible fluid phase (interstitial water). We first consider the finite deformation of soft hydrated tissues in which the solid phase is represented as hyperelastic. A finite element formulation of the governing nonlinear biphasic equations is presented based on a mixed-penalty approach and derived using the weighted residual method. Fluid and solid phase deformation, velocity, and pressure are interpolated within each element, and the pressure variables within each element are eliminated at the element level. A system of nonlinear, first-order differential equations in the fluid and solid phase deformation and velocity is obtained. In order to solve these equations, the contributions of the hyperelastic solid phase are incrementally linearized, a finite difference rule is introduced for temporal discretization, and an iterative scheme is adopted to achieve equilibrium at the end of each time increment. We demonstrate the accuracy and adequacy of the procedure using a six-node, isoparametric axisymmetric element, and we present an example problem for which independent numerical solution is available. Next, we present an automated, adaptive environment for the simulation of soft tissue continua in which the finite element analysis is coupled with automatic mesh generation, error indicators, and projection methods. Mesh generation and updating, including both refinement and coarsening, for the two-dimensional examples examined in this study are performed using the finite quadtree approach. The adaptive analysis is based on an error indicator which is the L2 norm of the difference between the finite element solution and a projected finite element solution. Total stress, calculated as the sum of the solid and fluid phase stresses, is used in the error indicator. To allow the finite difference algorithm to proceed in time using an updated mesh, solution values must be transferred to the new nodal locations. This rezoning is accomplished using a projected field for the primary variables. The accuracy and effectiveness of this adaptive finite element analysis is demonstrated using a linear, two-dimensional, axisymmetric problem corresponding to the indentation of a thin sheet of soft tissue. The method is shown to effectively capture the steep gradients and to produce solutions in good agreement with independent, converged, numerical solutions.

Uptake of Uranium and Other Elements of Concern by Plants Growing on Uranium Mill Tailings Disposal Cells

NASA Astrophysics Data System (ADS)

Joseph, C. N.; Waugh, W.; Glenn, E.

2015-12-01

The U.S. Department of Energy (DOE) is responsible for long-term stewardship of disposal cells for uranium mill tailings throughout the United States. Rock-armored disposal cell covers create favorable habitat for deep-rooted plants by reducing soil evaporation, increasing soil water storage, and trapping windblown dust, thereby providing water and nutrients for plant germination and establishment. DOE is studying the tradeoffs of potential detrimental and beneficial effects of plants growing on disposal cell covers to develop a rational and consistent vegetation management policy. Plant roots often extend vertically through disposal cell covers into underlying tailings, therefore, uptake of tailings contaminants and dissemination through animals foraging on stems and leaves is a possible exposure pathway. The literature shows that plant uptake of contaminants in uranium mill tailings occurs, but levels can vary widely depending on plant species, tailings and soil chemistry, and cover soil hydrology. Our empirical field study measured concentrations of uranium, radium, thorium, molybdenum, selenium, manganese, lead, and arsenic in above ground tissues harvested from plants growing on disposal cells near Native American communities in western states that represent a range of climates, cover designs, cover soil types, and vegetation types. For risk screening, contaminant levels in above ground tissues harvested from plants on disposal cells were compared to Maximum Tolerance Levels (MTLs) set for livestock by the National Research Council, and to tissue levels in the same plant species growing in reference areas near disposal cells. Although tailings were covered with uncontaminated soils, for 14 of 46 comparisons, levels of uranium and other contaminants were higher in plants growing on disposal cells compared to reference area plants, indicating possible mobilization of these elements from the tailing into plant tissues. However, with one exception, all plant levels were well below MTLs. Selenium, the only element that exceeded its MTL, likely originated in local seleniferous soil found both at reference areas and in disposal cell covers, and not in the underlying tailings. Our screening risk assessment suggests that allowing plants to grow on disposal cells appears to be safe.

Accumulation of Metals in Juvenile Carp (Cyprinus carpio) Exposed to Sublethal Levels of Iron and Manganese: Survival, Body Weight and Tissue.

PubMed

Harangi, Sándor; Baranyai, Edina; Fehér, Milán; Tóth, Csilla Noémi; Herman, Petra; Stündl, László; Fábián, István; Tóthmérész, Béla; Simon, Edina

2017-05-01

Many oxbows are contaminated by Fe and Mn as a consequence of the elemental concentration of sediment and water originating from the Upper Tisza Region of Hungary. The phenomenon is partly caused by anthropogenic activities and mainly due to the geochemical characteristics of the region. The effects of Fe and Mn on the aquatic ecosystem of these wetlands were investigated in a model experiments in this study. Survival, individual body weight and the elemental concentrations of organs were determined in common carp (Cyprinus carpio) juveniles reared in Fe and Mn contaminated media (treatment 1: Fe 0.57 mg L -1 , Mn 0.29 mg L -1 , treatment 2: Fe 0.57 mg L -1 , Mn 0.625 mg L -1 , treatment 3: Fe 1.50 mg L -1 , Mn 0.29 mg L -1 , treatment 4: Fe 1.50 mg L -1 , Mn 0.625 mg L -1 and control: Fe 0.005 mg L -1 , Mn 0.003 mg L -1 ), for rearing time of 49 days. The treatment with Fe and Mn did not have any effect on the survival data and individual body weight in the levels tested. The highest concentration of Fe and Mn was found in the liver and brain of carp juveniles, while the lowest concentration of these elements occurred in the muscular tissue and gills. The treatment where Fe and Mn were applied in the highest concentrations resulted in a statistically higher level of these elements in the brain, grills and muscle tissues. The treatment where only Mn was present in the highest concentration caused increased level of Mn only in the liver. We found metal accumulation in almost every organ; however, the applied concentrations and exposure time did not affect the survival and average body weight of carp juveniles.

Socio-demographic, lifestyle, and dietary determinants of essential and possibly-essential trace element levels in adipose tissue from an adult cohort.

PubMed

Rodríguez-Pérez, Celia; Vrhovnik, Petra; González-Alzaga, Beatriz; Fernández, Mariana F; Martin-Olmedo, Piedad; Olea, Nicolás; Fiket, Željka; Kniewald, Goran; Arrebola, Juan P

2018-05-01

There is increasing evidence linking levels of trace elements (TEs) in adipose tissue with certain chronic conditions (e.g., diabetes or obesity). The objectives of this study were to assess concentrations of a selection of nine essential and possibly-essential TEs in adipose tissue samples from an adult cohort and to explore their socio-demographic, dietary, and lifestyle determinants. Adipose tissue samples were intraoperatively collected from 226 volunteers recruited in two public hospitals from Granada province. Trace elements (Co, Cr, Cu, Fe, Mn, Mo, Se, V, and Zn) were analyzed in adipose tissue by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Data were collected on socio-demographic characteristics, lifestyle, diet, and health status by face-to-face interview. Predictors of TE concentrations were assessed by using multivariable linear and logistic regression. All TEs were detected in all samples with the exception of Se (53.50%). Iron, zinc, and copper showed the highest concentrations (42.60 mg/kg, 9.80 mg/kg, and 0.68 mg/kg, respectively). Diet was the main predictor of Cr, Fe, Mo, and Se concentrations. Body mass index was negatively associated with all TEs (β coefficients = -0.018 to -0.593, p = 0.001-0.090) except for Mn and V. Age showed a borderline-significant positive correlation with Cu (β = 0.004, p = 0.089). Residence in a rural or semi-rural area was associated with increased Co, Cr, Fe, Mo, Mn, V and Zn concentrations and with β coefficients ranging from 0.196 to 0.544 (p < 0.05). Furthermore, individuals with higher educational level showed increased Cr, Co, Fe and V concentrations (β coefficients = 0.276-0.368, p = 0.022-0.071). This is the first report on the distribution of these TEs in adipose tissue and on their determinants in a human cohort and might serve as an initial step in the elucidation of their clinical relevance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Two-Element Transducer for Ultrasound

NASA Technical Reports Server (NTRS)

Lecroissette, D. H.; Heyser, R. C.

1986-01-01

Separation of transmitting and receiving units improves probing of deep tissue. Ultrasonic transducer has dual elements to increase depth at which sonic images are made of biological tissue. Transducer uses separate transmitting and receiving elements, and frequency response of receiving element independently designed to accommodate attenuation of higher frequencies by tissue. New transducer intended for pulse-echo ultrasonic systems in which reflected sound pulses reveal features in tissue.

Revealing the Penumbra through Imaging Elemental Markers of Cellular Metabolism in an Ischemic Stroke Model.

PubMed

Pushie, M Jake; Crawford, Andrew M; Sylvain, Nicole J; Hou, Huishu; Hackett, Mark J; George, Graham N; Kelly, Michael E

2018-05-16

Stroke exacts a heavy financial and economic burden, is a leading cause of death, and is the leading cause of long-term disability in those who survive. The penumbra surrounds the ischemic core of the stroke lesion and is composed of cells that are stressed and vulnerable to death, which is due to an altered metabolic, oxidative, and ionic environment within the penumbra. Without therapeutic intervention, many cells within the penumbra will die and become part of the growing infarct, however, there is hope that appropriate therapies may allow potential recovery of cells within this tissue region, or at least slow the rate of cell death, therefore, slowing the spread of the ischemic infarct and minimizing the extent of tissue damage. As such, preserving the penumbra to promote functional brain recovery is a central goal in stroke research. While identification of the ischemic infarct, and the infarct/penumbra boundary is relatively trivial using classical histology and microscopy techniques, accurately assessing the penetration of the penumbra zone into undamaged brain tissue, and evaluating the magnitude of chemical alterations in the penumbra, has long been a major challenge to the stroke research field. In this study, we have used synchrotron-based X-ray fluorescence imaging to visualize the elemental changes in undamaged, penumbra, and infarct brain tissue, following ischemic stroke. We have employed a Gaussian mixture model to cluster tissue areas based on their elemental characteristics. The method separates the core of the infarct from healthy tissue, and also demarcates discrete regions encircling the infarct. These regions of interest can be combined with elemental and metabolic data, as well as with conventional histology. The cell populations defined by clustering provide a reproducible means of visualizing the size and extent of the penumbra at the level of the single cell and provide a critically needed tool to track changes in elemental status and penumbra size.

Mapping fundamental life elements in papillary thyroid carcinoma tissue

NASA Astrophysics Data System (ADS)

Merolle, L.; Ragazzi, M.; Gianoncelli, A.; Altissimo, M.; Ciarrocchi, A.; Bedolla, D. E.; Marraccini, C.; Baricchi, R.; Pertinhez, T. A.

2018-05-01

Well-differentiated papillary thyroid carcinomas (PTCs) are the most common type of thyroid cancer. Thyroid function depends on the presence of certain trace elements necessary for both the synthesis and the metabolism of thyroid hormones. We conducted an observational translational study on formalin fixed paraffin embedded thyroid tissue slices collected from five patients who underwent surgical resection of thyroid gland after thyroid cancer diagnosis. A synchrotron-based XRF set up was used to map the distribution of oxygen, sodium, aluminum, selenium and magnesium in PTC sections. These experiments were performed at the TwinMic beamline (Elettra—Sincrotrone Trieste, Trieste, Italy). Our results show that Mg levels in PTC tissues are significantly higher than in the control ones. The results seem to provide highly valuable information suggesting that Mg may play a role in the development and metabolic process of PTC.

Quantitative mapping of elemental distribution in leaves of the metallophytes Helichrysum candolleanum, Blepharis aspera, and Blepharis diversispina from Selkirk Cu-Ni mine, Botswana

NASA Astrophysics Data System (ADS)

Koosaletse-Mswela, Pulane; Przybyłowicz, Wojciech J.; Cloete, Karen J.; Barnabas, Alban D.; Torto, Nelson; Mesjasz-Przybyłowicz, Jolanta

2015-11-01

Multi-element profiling is essential in understanding the metal-tolerant behavior of metallophytes. Although previous reports using multi-elemental analyses show that the metallophytes Blepharis aspera, Blepharis diversispina (Acanthaceae) and Helichrysum candolleanum (Asteraceae) take up metals, no information exists on elemental spatial distribution and concentrations in specific tissues of these plants. The aim of this study therefore was to assess the spatial distribution and concentration of copper, nickel and other elements in leaf tissues of these plants using micro-PIXE. Whole plants were collected with soil in pots from an operational copper and nickel mine (i.e., a copper and nickel mineralized area), Selkirk, about 40 km north-east of Francistown, Botswana. On the same day the samples were transported by air to iThemba LABS in South Africa. Leaf specimens were cryofixed in liquid propane cooled by LN2. Parallel samples were embedded in resin for anatomical studies to facilitate interpretation of elemental maps. The distribution and concentration of copper, nickel, and other elements in leaf tissues were determined using micro-PIXE and proton backscattering spectrometry. Data evaluation was performed using GeoPIXE II software. Micro-PIXE showed that H. candolleanum had the highest whole leaf content of copper (70 ± 3 μg g-1 DW) and nickel (168 ± 5 μg g-1 DW), followed by B. aspera (Cu: 25 ± 1 μg g-1 DW; Ni: 166 ± 4 μg g-1 DW) and B. diversispina (Cu: 3 ± 1 μg g-1 DW; Ni, below detection limit). For specific leaf tissues, the highest levels of copper were found in the vascular bundle for H. candolleanum (167 ± 7 μg g-1 DW) and the lower epidermis for B. aspera (70 ± 9 μg g-1 DW). The highest levels of nickel were present in the vascular bundle of B. aspera (479 ± 10 μg g-1 DW) and H. candolleanum (90 ± 5 μg g-1 DW). Elemental maps showed a similar distribution pattern for copper and nickel in B. aspera and B diversispina, with these elements concentrated in the upper and lower epidermal regions. However, for H. candolleanum, both copper and nickel were concentrated in the mesophyll. The difference in concentration and accumulation patterns between B. aspera, B. diversispina and H. candolleanum suggests that the metal-tolerant adaptation of these metallophytes may differ.

Construction of a three-dimensional finite element model of maxillary first molar and it's supporting structures

PubMed Central

Begum, M. Sameena; Dinesh, M. R.; Tan, Kenneth F. H.; Jairaj, Vani; Md Khalid, K.; Singh, Varun Pratap

2015-01-01

The finite element method (FEM) is a powerful computational tool for solving stress-strain problems; its ability to handle material inhomogeneity and complex shapes makes the FEM, the most suitable method for the analysis of internal stress levels in the tooth, periodontium, and alveolar bone. This article intends to explain the steps involved in the generation of a three-dimensional finite element model of tooth, periodontal ligament (PDL) and alveolar bone, as the procedure of modeling is most important because the result is based on the nature of the modeling systems. Finite element analysis offers a means of determining strain-stress levels in the tooth, ligament, and bone structures for a broad range of orthodontic loading scenarios without producing tissue damage. PMID:26538895

Controlled insertional mutagenesis using a LINE-1 (ORFeus) gene-trap mouse model.

PubMed

O'Donnell, Kathryn A; An, Wenfeng; Schrum, Christina T; Wheelan, Sarah J; Boeke, Jef D

2013-07-16

A codon-optimized mouse LINE-1 element, ORFeus, exhibits dramatically higher retrotransposition frequencies compared with its native long interspersed element 1 counterpart. To establish a retrotransposon-mediated mouse model with regulatable and potent mutagenic capabilities, we generated a tetracycline (tet)-regulated ORFeus element harboring a gene-trap cassette. Here, we show that mice expressing tet-ORFeus broadly exhibit robust retrotransposition in somatic tissues when treated with doxycycline. Consistent with a significant mutagenic burden, we observed a reduced number of double transgenic animals when treated with high-level doxycycline during embryogenesis. Transgene induction in skin resulted in a white spotting phenotype due to somatic ORFeus-mediated mutations that likely disrupt melanocyte development. The data suggest a high level of transposition in melanocyte precursors and consequent mutation of genes important for melanoblast proliferation, differentiation, or migration. These findings reveal the utility of a retrotransposon-based mutagenesis system as an alternative to existing DNA transposon systems. Moreover, breeding these mice to different tet-transactivator/reversible tet-transactivator lines supports broad functionality of tet-ORFeus because of the potential for dose-dependent, tissue-specific, and temporal-specific mutagenesis.

Tissue-Specific Methylation of Long Interspersed Nucleotide Element-1 of Homo Sapiens (L1Hs) During Human Embryogenesis and Roles in Neural Tube Defects.

PubMed

Wang, L; Chang, S; Guan, J; Shangguan, S; Lu, X; Wang, Z; Wu, L; Zou, J; Zhao, H; Bao, Y; Qiu, Z; Niu, B; Zhang, T

2015-01-01

Epigenetic regulation of long interspersed nucleotide element-1 (LINE-1) retrotransposition events plays crucial roles during early development. Previously we showed that LINE-1 hypomethylation in neuronal tissues is associated with pathogenesis of neural tube defect (NTD). Herein, we further evaluated LINE-1 Homo sapiens (L1Hs) methylation in tissues derived from three germ layers of stillborn NTD fetuses, to define patterns of tissue specific methylation and site-specific hypomethylation at CpG sites within an L1Hs promoter region. Stable, tissue-specific L1Hs methylation patterns throughout three germ layer lineages of the fetus, placenta, and maternal peripheral blood were observed. Samples from maternal peripheral blood exhibited the highest level of L1Hs methylation (64.95%) and that from placenta showed the lowest (26.82%). Between samples from NTDs and controls, decrease in L1Hs methylation was only significant in NTD-affected brain tissue at 7.35%, especially in females (8.98%). L1Hs hypomethylation in NTDs was also associated with a significant increase in expression level of an L1Hs-encoded transcript in females (r = -0.846, p = 0.004). This could be due to genomic DNA instability and alternation in chromatins accessibility resulted from abnormal L1Hs hypomethylation, as showed in this study with HCT-15 cells treated with methylation inhibitor 5-Aza.

Selected organic compounds and trace elements in streambed sediments and fish tissues, Cook Inlet Basin, Alaska

USGS Publications Warehouse

Frenzel, Steven A.

2000-01-01

Organochlorines, semivolatile organic compounds (SVOCs), and trace elements were investigated in streambed sediments and fish tissues at selected sites in the Cook Inlet Basin, Alaska, during 1998. At most sites, SVOCs and organochlorine compounds were either not detected or detected at very low concentrations. Chester Creek at Arctic Boulevard at Anchorage, which was the only site sampled with a significant degree of development in the watershed, had elevated levels of many SVOCs in streambed sediment. Coring of sediments from two ponds on Chester Creek confirmed the presence of elevated concentrations of a variety of organic compounds. Moose Creek, a stream with extensive coal deposits in its watershed, had low concentrations of numerous SVOCs in streambed sediment. Three sites located in national parks or in a national wildlife refuge had no detectable concentrations of SVOCs. Trace elements were analyzed in both streambed sediments and tissues of slimy sculpin. The two media provided similar evidence for elevated concentrations of cadmium, lead, and zinc at Chester Creek. In this study, 'probable effect levels '(PELs) were determined from sediments finer than 0.063 millimeters, where concentrations tend to be greatest. Arsenic and chromium concentrations exceeded the PEL at eight and six sites respectively. Zinc exceeded the PEL at one site. Cadmium and copper concentrations were smaller than the PEL at all sites. Mercury concentrations in streambed sediments from the Deshka River were near the PEL, and selenium concentrations at that site also appear to be elevated above background levels. At half the sites where slimy sculpin were sampled, selenium concentrations were at levels that may cause adverse effects in some species.

The muscle creatine kinase gene is regulated by multiple upstream elements, including a muscle-specific enhancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaynes, J.B.; Johnson, J.E.; Buskin, J.N.

1988-01-01

Muscle creatine kinase (MCK) is induced to high levels during skeletal muscle differentiation. The authors examined the upstream regulatory elements of the mouse MCK gene which specify its activation during myogenesis in culture. Fusion genes containing up to 3,300 nucleotides (nt) of MCK 5' flanking DNA in various positions and orientations relative to the bacterial chloramphenicol acetyltransferase (CAT) structural gene were transfected into cultured cells. Transient expression of CAT was compared between proliferating and differentiated MM14 mouse myoblasts and with nonmyogenic mouse L cells. The major effector of high-level expression was found to have the properties of a transcriptional enhancer.more » This element, located between 1,050 and 1,256 nt upstream of the transcription start site, was also found to have a major influence on the tissue and differentiation specificity of MCK expression; it activated either the MCK promoter or heterologous promoters only in differentiated muscle cells. Comparisons of viral and cellular enhancer sequences with the MCK enhancer revealed some similarities to essential regions of the simian virus 40 enhancer as well as to a region of the immunoglobulin heavy-chain enhancer, which has been implicated in tissue-specific protein binding. Even in the absence of the enhancer, low-level expression from a 776-nt MCK promoter retained differentiation specificity. In addition to positive regulatory elements, our data provide some evidence for negative regulatory elements with activity in myoblasts. These may contribute to the cell type and differentiation specificity of MCK expression.« less

[Topographological-anatomic changes in the structure of temporo-mandibular joint in case of fracture of the mandible condylar process at cervical level].

PubMed

Volkov, S I; Bazhenov, D V; Semkin, V A

2011-01-01

Pathological changes in soft tissues surrounding the fracture site as well as in the structural elements of temporo-mandibular joint always occured in condylar process fracture with shift at cervical mandibular jaw level. Other changes were also seen in the joint on the opposite normal side. Modelling of condylar process fracture at mandibular cervical level by means of three-dimensional computer model of temporo-mandibular joint contributed to proper understanding of this pathology emergence as well as to prediction and elimination of disorders arising in adjacent to the fracture site tissues.

Prediction of oxygen distribution in aortic valve leaflet considering diffusion and convection.

PubMed

Wang, Ling; Korossis, Sotirios; Fisher, John; Ingham, Eileen; Jin, Zhongmin

2011-07-01

Oxygen supply and transport is an important consideration in the development of tissue engineered constructs. Previous studies from our group have focused on the effect of tissue thickness on the oxygen diffusion within a three-dimensional aortic valve leaflet model, and highlighted the necessity for additional transport mechanisms such as oxygen convection. The aims of this study were to investigate the effect of interstitial fluid flow within the aortic valve leaflet, induced by the cyclic loading of the leaflet, on oxygen transport. Indentation testing and finite element modelings were employed to derive the biphasic properties of the leaflet tissue. The biphasic properties were subsequently used in the computational modeling of oxygen convection in the leaflet, which was based on the effective interstitial fluid velocity and the tissue deformation. Subsequently, the oxygen profile was predicted within the valve leaflet model by solving the diffusion and convection equation simultaneously utilizing the finite difference method. The compression modulus (E) and hydraulic permeability were determined by adapting a finite element model to the experimental indentation test on valvular tissue, E = 0.05MPa, and k =2.0 mm4/Ns. Finite element model of oxygen convection in valvular tissue incorporating the predicted biphasic properties was developed and the interstitial fluid flow rate was calculated falling in range of 0.025-0.25 mm/s depending on the tissue depth. Oxygen distribution within valvular tissue was predicted using one-dimensional oxygen diffusion model taking into consider the interstitial fluid effect. It was found that convection did enhance the oxygen transport in valvular tissue by up to 68% increase in the minimum oxygen tension within the tissue, depending on the strain level of the tissue as reaction of the magnitude and frequencies of the cardiac loading. The effective interstitial fluid velocity was found to play an important role in enhancing the oxygen transport within the valve leaflet. Such an understanding is important in the development of valvular tissue engineered constructs.

REE compositions in fossil vertebrate dental tissues indicate biomineral preservation

NASA Astrophysics Data System (ADS)

Žigaite, Ž.; Kear, B.; Pérez-Huerta, A.; Jeffries, T.; Blom, H.

2012-04-01

Rare earth element (REE) abundances have been measured in a number of Palaeozoic and Mesozoic dental tissues using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS). Fossil vertebrates analysed comprise scales and tesserae of Silurian and Devonian acanthodians, chondrichthyans, galeaspids, mongolepids, thelodonts, as well as teeth of Cretaceous lungfish and marine reptiles. The evaluation of fossil preservation level has been made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections, using Energy Dispersive X-ray Spectroscopy (EDS). Fossil teeth and scales with significant structure and colour alteration have shown elevated heavy element concentrations, and the silicification of bioapatite has been common in their tissues. Stable oxygen isotope measurements (δ18O) of bulk biomineral have been conducted in parallel, and showed comparatively lower heavy oxygen values in the same fossil tissues with stronger visible alteration. Significant difference in REE concentrations has been observed between the dentine and enamel of Cretaceous plesiosaurs, suggesting the enamel to be more geochemically resistant to diagenetic overprint.

Elemental Analysis of Bone, Teeth, Horn and Antler in Different Animal Species Using Non-Invasive Handheld X-Ray Fluorescence.

PubMed

Buddhachat, Kittisak; Klinhom, Sarisa; Siengdee, Puntita; Brown, Janine L; Nomsiri, Raksiri; Kaewmong, Patcharaporn; Thitaram, Chatchote; Mahakkanukrauh, Pasuk; Nganvongpanit, Korakot

2016-01-01

Mineralized tissues accumulate elements that play crucial roles in animal health. Although elemental content of bone, blood and teeth of human and some animal species have been characterized, data for many others are lacking, as well as species comparisons. Here we describe the distribution of elements in horn (Bovidae), antler (Cervidae), teeth and bone (humerus) across a number of species determined by handheld X-ray fluorescence (XRF) to better understand differences and potential biological relevance. A difference in elemental profiles between horns and antlers was observed, possibly due to the outer layer of horns being comprised of keratin, whereas antlers are true bone. Species differences in tissue elemental content may be intrinsic, but also related to feeding habits that contribute to mineral accumulation, particularly for toxic heavy metals. One significant finding was a higher level of iron (Fe) in the humerus bone of elephants compared to other species. This may be an adaptation of the hematopoietic system by distributing Fe throughout the bone rather than the marrow, as elephant humerus lacks a marrow cavity. We also conducted discriminant analysis and found XRF was capable of distinguishing samples from different species, with humerus bone being the best source for species discrimination. For example, we found a 79.2% correct prediction and success rate of 80% for classification between human and non-human humerus bone. These findings show that handheld XRF can serve as an effective tool for the biological study of elemental composition in mineralized tissue samples and may have a forensic application.

Elemental Analysis of Bone, Teeth, Horn and Antler in Different Animal Species Using Non-Invasive Handheld X-Ray Fluorescence

PubMed Central

Buddhachat, Kittisak; Klinhom, Sarisa; Siengdee, Puntita; Brown, Janine L.; Nomsiri, Raksiri; Kaewmong, Patcharaporn; Thitaram, Chatchote; Mahakkanukrauh, Pasuk; Nganvongpanit, Korakot

2016-01-01

Mineralized tissues accumulate elements that play crucial roles in animal health. Although elemental content of bone, blood and teeth of human and some animal species have been characterized, data for many others are lacking, as well as species comparisons. Here we describe the distribution of elements in horn (Bovidae), antler (Cervidae), teeth and bone (humerus) across a number of species determined by handheld X-ray fluorescence (XRF) to better understand differences and potential biological relevance. A difference in elemental profiles between horns and antlers was observed, possibly due to the outer layer of horns being comprised of keratin, whereas antlers are true bone. Species differences in tissue elemental content may be intrinsic, but also related to feeding habits that contribute to mineral accumulation, particularly for toxic heavy metals. One significant finding was a higher level of iron (Fe) in the humerus bone of elephants compared to other species. This may be an adaptation of the hematopoietic system by distributing Fe throughout the bone rather than the marrow, as elephant humerus lacks a marrow cavity. We also conducted discriminant analysis and found XRF was capable of distinguishing samples from different species, with humerus bone being the best source for species discrimination. For example, we found a 79.2% correct prediction and success rate of 80% for classification between human and non-human humerus bone. These findings show that handheld XRF can serve as an effective tool for the biological study of elemental composition in mineralized tissue samples and may have a forensic application. PMID:27196603

Physiologically relevant organs on chips

PubMed Central

Yum, Kyungsuk; Hong, Soon Gweon; Lee, Luke P.

2015-01-01

Recent advances in integrating microengineering and tissue engineering have generated promising microengineered physiological models for experimental medicine and pharmaceutical research. Here we review the recent development of microengineered physiological systems, or organs on chips, that reconstitute the physiologically critical features of specific human tissues and organs and their interactions. This technology uses microengineering approaches to construct organ-specific microenvironments, reconstituting tissue structures, tissue–tissue interactions and interfaces, and dynamic mechanical and biochemical stimuli found in specific organs, to direct cells to assemble into functional tissues. We first discuss microengineering approaches to reproduce the key elements of physiologically important, dynamic mechanical microenvironments, biochemical microenvironments, and microarchitectures of specific tissues and organs in microfluidic cell culture systems. This is followed by examples of microengineered individual organ models that incorporate the key elements of physiological microenvironments into single microfluidic cell culture systems to reproduce organ-level functions. Finally, microengineered multiple organ systems that simulate multiple organ interactions to better represent human physiology, including human responses to drugs, is covered in this review. This emerging organs-on-chips technology has the potential to become an alternative to 2D and 3D cell culture and animal models for experimental medicine, human disease modeling, drug development, and toxicology. PMID:24357624

Evaluation of specimen preparation techniques for micro-PIXE localisation of elements in hyperaccumulating plants

NASA Astrophysics Data System (ADS)

Kachenko, Anthony G.; Siegele, Rainer; Bhatia, Naveen P.; Singh, Balwant; Ionescu, Mihail

2008-04-01

Hybanthus floribundus subsp. floribundus, a rare Australian Ni-hyperaccumulating shrub and Pityrogramma calomelanos var. austroamericana, an Australian naturalized As-hyperaccumulating fern are promising species for use in phytoremediation of contaminated sites. Micro-proton-induced X-ray emission (μ-PIXE) spectroscopy was used to map the elemental distribution of the accumulated metal(loid)s, Ca and K in leaf or pinnule tissues of the two plant species. Samples were prepared by two contrasting specimen preparation techniques: freeze-substitution in tetrahydrofuran (THF) and freeze-drying. The specimens were analysed to compare the suitability of each technique in preserving (i) the spatial elemental distribution and (ii) the tissue structure of the specimens. Further, the μ-PIXE results were compared with concentration of elements in the bulk tissue obtained by ICP-AES analysis. In H. floribundus subsp. floribundus, μ-PIXE analysis revealed Ni, Ca and K concentrations in freeze-dried leaf tissues were at par with bulk tissue concentrations. Elemental distribution maps illustrated that Ni was preferentially localised in the adaxial epidermal tissues (1% DW) and least concentration was found in spongy mesophyll tissues (0.53% DW). Conversely, elemental distribution maps of THF freeze-substituted tissues indicated significantly lower Ni, Ca and K concentrations than freeze-dried specimens and bulk tissue concentrations. Moreover, Ni concentrations were uniform across the whole specimen and no localisation was observed. In P. calomelanos var. austroamericana freeze-dried pinnule tissues, μ-PIXE revealed statistically similar As, Ca and K concentrations as compared to bulk tissue concentrations. Elemental distribution maps showed that As localisation was relatively uniform across the whole specimen. Once again, THF freeze-substituted tissues revealed a significant loss of As compared to freeze-dried specimens and the concentrations obtained by bulk tissue analysis. The results demonstrate that freeze-drying is a suitable sample preparation technique to study elemental distribution of ions in H. floribundus and P. calomelanos plant tissues using μ-PIXE spectroscopy. Furthermore, cellular structure was preserved in samples prepared using this technique.

Tissue partition and risk assessments of trace elements in Indo-Pacific Finless Porpoises (Neophocaena phocaenoides) from the Pearl River Estuary coast, China.

PubMed

Zhang, Xiyang; Lin, Wenzhi; Yu, Ri-Qing; Sun, Xian; Ding, Yulong; Chen, Hailiang; Chen, Xi; Wu, Yuping

2017-10-01

Throughout the last few decades, an increased number of stranded marine mammals, particularly the Indo-Pacific Finless Porpoises (Neophocaena phocaenoides), were observed in the Pearl River Estuary (PRE). As long-lived, apex predators vulnerable to bioaccumulation of contaminants, the tissue residue levels and health risk of trace elements (TEs) in N. phocaenoides from the PRE have been little studied. Eleven typical TEs distributed in skin, liver and kidney tissues were investigated from 25 specimens stranded along the PRE from 2007 to 2015 in the present study. It revealed that most TEs were highly accumulated in internal organs (liver and kidney), except for Zn with high residue levels in external skin. Compared with the TEs in prey items, the residue levels of Hg, Se, Zn, Cu, Cd and Cr in N. phocaenoides increased 4-618 times, indicating a potentially significant biomagnification. Sex-related differences of TE accumulation were not obvious, except for renal Mn, in which the females showed lower mean concentrations than males. Significantly positive correlations between body length and TE levels were found for Hg, Se and Cd. Results of the calculated risk quotients (RQ) suggested that the risks to N. phocaenoides from consumption of prey items were generally low, but further attentions should be paid to Cd, Cr, Cu, Hg and As due to the elevated RQ values. The concentrations of Hg, Cd and Se in the epidermis were positively correlated with the levels found in internal organs. Our investigation provides evidence to support the use of skin as one biomonitoring approach on Hg, Cd and Se contamination of internal tissues in this species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trace element accumulation in hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) from Yaeyama Islands, Japan.

PubMed

Anan, Y; Kunito, T; Watanabe, I; Sakai, H; Tanabe, S

2001-12-01

Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Zr, Mo, Ag, Cd, Sb, Ba, Hg, Tl, and Pb) were determined in the liver, kidney, and muscle of green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Yaeyama Islands, Okinawa, Japan. Accumulation features of trace elements in the three tissues were similar between green and hawksbill turtles. No gender differences in trace element accumulation in liver and kidney were found for most of the elements. Significant growth-dependent variations were found in concentrations of some elements in tissues of green and hawksbill turtles. Significant negative correlations (p < 0.05) were found between standard carapace length (SCL) and the concentrations of Cu, Zn, and Se in the kidney and V in muscle of green turtles and Mn in the liver, Rb and Ag in kidney, and Hg in muscle of hawksbill turtles. Concentrations of Sr, Mo, Ag, Sb, and Tl in the liver, Sb in kidney, and Sb and Ba in muscle of green turtles and Se and Hg in the liver and Co, Se, and Hg in kidney of hawksbill turtles increased with an increase in SCL (p < 0.05). Green and hawksbill turtles accumulated extremely high concentrations of Cu in the liver and Cd in kidney, whereas the levels of Hg in liver were low in comparison with those of other higher-trophic-level marine animals. High accumulation of Ag in the liver of green turtles was also observed. To evaluate the trophic transfer of trace elements, concentrations of trace elements were determined in stomach contents of green and hawksbill turtles. A remarkably high trophic transfer coefficient was found for Ag and Cd in green turtles and for Cd and Hg in hawksbill turtles.

The Role of Trace Elements in Tinnitus.

PubMed

Yaşar, Mehmet; Şahin, Mehmet İlhan; Karakükçü, Çiğdem; Güneri, Erhan; Doğan, Murat; Sağıt, Mustafa

2017-03-01

In this study, we aimed to investigate the role of three trace elements, namely, zinc, copper, and lead, in tinnitus by analyzing the serum level of copper and lead and both the serum and tissue level of zinc. Eighty patients, who applied to outpatient otolaryngology clinic with the complaints of having tinnitus, and 28 healthy volunteers were included. High-frequency audiometry was performed, and participants who had hearing loss according to the pure tone average were excluded; tinnitus frequency and loudness were determined and tinnitus reaction questionnaire scores were obtained from the patients. Of all the participants, serum zinc, copper, and lead values were measured; moreover, zinc levels were examined in hair samples. The levels of trace elements were compared between tinnitus and control groups. The level of copper was found to be significantly lower in the tinnitus group (p = 0.02), but there was no significant difference between the groups in terms of the levels of zinc, neither in serum nor in hair, and lead in serum (p > 0.05). The lack of trace elements, especially that of "zinc," have been doubted for the etiopathogenesis of tinnitus in the literature; however, we only found copper levels to be low in patients having tinnitus.

The impact of adipogenic diet on rats' tissue trace elements content.

PubMed

Tinkov, A A; Gatiatulina, E R; Popova, E V; Polyakova, V S; Skalvaya, A A; Agletdinov, E F; Nikonorov, A A; Radysh, I V; Kkarganov, M Yu; Skalny, A V

2016-01-01

The influence of high-fat diet (HFD) on trace elements status, adipokine level, and markers of carbohydrate and lipid metabolism in weanling Wistar rats was investigated. A total of 20 male 1-months-old Wistar rats divided into two equal groups were used in the present study. The first group of animals obtained a standard diet (STD), whereas animals from the second group (NAFLD) were maintained on high-fat diet containing 10 and 31.6% of total calories from fat, respectively, during 1 month. Fat diet (HFD). Trace element status (using inductively coupled plasma mass spectrometry), serum levels of insulin, adiponectin, and leptin (using enzyme-linked immunosorbent assay), total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), glucose (spectrophotometrically), apolipoprotein A1 (ApoA1) and B (ApoB) (using immunoturbidimetric method) were assessed. It was shown that 1-month HFD feeding resulted in significant increase of EDAT, RPAT, total adipose tissue mass, and adipocyte area. HFD-fed animals were also characterized by a significant increase in circulating leptin levels and leptin-to-adiponectin ratio as compared to the control ones. No significant HFD-related difference in serum lipid spectrum, adiponectin, apolipoproteins, glucose, insulin, and HOMA-IR were revealed. Liver Cu, I, Mn, Se, Zn; EDAT Cr, V, Co, Cu, Fe,I, and RPAT Co, Cu, I, Cr, V, Fe, and Zn were significantly decreased in HFD-fed rats in comparison with the control group levels. Hair Co, Mn, Si, and V levels significantly exceeded the respective control values, whereas Se and I content were decreased in studied animals. At the same time, only serum Cu was significantly decreased in HFD-fed rats. The interplay between the impaired trace elements metabolism of HFD-fed weanling Wistar rats and disorder of adipokine balance was demonstrated. It is supposed that the altered trace elements status is primary and precedes other metabolic obesity-related disturbances.

An Autonomous BMP2 Regulatory Element in Mesenchymal Cells

PubMed Central

Kruithof, Boudewijn P.T.; Fritz, David T.; Liu, Yijun; Garsetti, Diane E.; Frank, David B.; Pregizer, Steven K.; Gaussin, Vinciane; Mortlock, Douglas P.; Rogers, Melissa B.

2014-01-01

BMP2 is a morphogen that controls mesenchymal cell differentiation and behavior. For example, BMP2 concentration controls the differentiation of mesenchymal precursors into myocytes, adipocytes, chondrocytes, and osteoblasts. Sequences within the 3′untranslated region (UTR) of the Bmp2 mRNA mediate a post-transcriptional block of protein synthesis. Interaction of cell and developmental stage-specific trans-regulatory factors with the 3′UTR is a nimble and versatile mechanism for modulating this potent morphogen in different cell types. We show here, that an ultra-conserved sequence in the 3′UTR functions independently of promoter, coding region, and 3′UTR context in primary and immortalized tissue culture cells and in transgenic mice. Our findings indicate that the ultra-conserved sequence is an autonomously functioning post-transcriptional element that may be used to modulate the level of BMP2 and other proteins while retaining tissue specific regulatory elements. PMID:21268088

Physiologically relevant organs on chips.

PubMed

Yum, Kyungsuk; Hong, Soon Gweon; Healy, Kevin E; Lee, Luke P

2014-01-01

Recent advances in integrating microengineering and tissue engineering have generated promising microengineered physiological models for experimental medicine and pharmaceutical research. Here we review the recent development of microengineered physiological systems, or also known as "ogans-on-chips", that reconstitute the physiologically critical features of specific human tissues and organs and their interactions. This technology uses microengineering approaches to construct organ-specific microenvironments, reconstituting tissue structures, tissue-tissue interactions and interfaces, and dynamic mechanical and biochemical stimuli found in specific organs, to direct cells to assemble into functional tissues. We first discuss microengineering approaches to reproduce the key elements of physiologically important, dynamic mechanical microenvironments, biochemical microenvironments, and microarchitectures of specific tissues and organs in microfluidic cell culture systems. This is followed by examples of microengineered individual organ models that incorporate the key elements of physiological microenvironments into single microfluidic cell culture systems to reproduce organ-level functions. Finally, microengineered multiple organ systems that simulate multiple organ interactions to better represent human physiology, including human responses to drugs, is covered in this review. This emerging organs-on-chips technology has the potential to become an alternative to 2D and 3D cell culture and animal models for experimental medicine, human disease modeling, drug development, and toxicology. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effects of levosimendan exposure on oxidant/antioxidant status and trace element levels in the pulmonary artery of rats.

PubMed

Ay, Yasin; Aydın, Cemalettin; Basel, Halil; Bektaş, Hava; Bülüt, Gülay; Inan, Bekir; Ay, Nuray Kahraman; Demir, Ismail

2013-06-01

We investigated both the effect of levosimendan and the role of oxidant/antioxidant status and trace element levels in the pulmonary artery of rats. Fourteen male Wistar albino rats were randomly divided into two groups of seven animals each. Group 1 was not exposed to levosimendan and served as a control. Levosimendan (12 μg/kg) diluted in 10 ml 0.9 % NaCl was administered intraperitoneally to group 2. Animals of both groups were killed after 3 days, and their pulmonary arteries were harvested to determine changes in tissue oxidant/antioxidant status and trace element levels. The animals in both groups were killed 72 h after the levosimendan exposure treatment, and pulmonary arteries were harvested to determine levels of the lipid peroxidation product MDA and the antioxidant GSH as well as the decreased activity of antioxidant enzymes such as SOD, GSH-Px and CAT. It was found that MDA levels increased in pulmonary artery tissues of rats after levosimendan administration. The GSH level decreased in the pulmonary artery of rats after levosimendan treatment. Co, Mn, Fe, Cd and Pb levels were significantly higher (P < 0.001) and Mg, Zn and Cu levels significantly lower (P < 0.001) in the levosimendan group compared to the control group. These results suggest that levosimendan treatment caused an increase in free radical production and a decrease in antioxidant enzyme activity in the pulmonary artery of levosimendan-treated rats. It also caused a decrease or increase in the levels of many minerals in the pulmonary artery, which is an undesirable condition for normal pharmacological function.

Method of holding optical elements without deformation during their fabrication

DOEpatents

Hed, P.P.

1997-04-29

An improved method for securing and removing an optical element to and from a blocking tool without causing deformation of the optical element is disclosed. A lens tissue is placed on the top surface of the blocking tool. Dots of UV cement are applied to the lens tissue without any of the dots contacting each other. An optical element is placed on top of the blocking tool with the lens tissue sandwiched therebetween. The UV cement is then cured. After subsequent fabrication steps, the bonded blocking tool, lens tissue, and optical element are placed in a debonding solution to soften the UV cement. The optical element is then removed from the blocking tool. 16 figs.

Method of holding optical elements without deformation during their fabrication

DOEpatents

Hed, P. Paul

1997-01-01

An improved method for securing and removing an optical element to and from a blocking tool without causing deformation of the optical element. A lens tissue is placed on the top surface of the blocking tool. Dots of UV cement are applied to the lens tissue without any of the dots contacting each other. An optical element is placed on top of the blocking tool with the lens tissue sandwiched therebetween. The UV cement is then cured. After subsequent fabrication steps, the bonded blocking tool, lens tissue, and optical element are placed in a debonding solution to soften the UV cement. The optical element is then removed from the blocking tool.

Unliganded estrogen receptor α stimulates bone sialoprotein gene expression.

PubMed

Takai, Hideki; Matsumura, Hiroyoshi; Matsui, Sari; Kim, Kyung Mi; Mezawa, Masaru; Nakayama, Yohei; Ogata, Yorimasa

2014-04-10

Estrogen is one of the steroid hormones essential for skeletal development. The estrogen receptor (ER) is a transcription factor and a member of the steroid receptor superfamily. There are two different forms of the ER, usually referred to as α and β, each encoded by a separate gene. Hormone-activated ERs form dimers, since the two forms are coexpressed in many cell types. Bone sialoprotein (BSP) is a tissue-specific acidic glycoprotein that is expressed by differentiated osteoblasts, odontoblasts and cementoblasts during the initial formation of mineralized tissue. To determine the molecular basis of the tissue-specific expression of BSP and its regulation by estrogen and the ER, we have analyzed the effects of β-estradiol and ERα on BSP gene transcription. ERα protein levels were increased after ERα overexpression in ROS17/2.8 cells. While BSP mRNA levels were increased by ERα overexpression, the endogenous and overexpressed BSP mRNA levels were not changed by β-estradiol (10(-8)M, 24 h). Luciferase activities of different sized BSP promoter constructs (pLUC3~6) were increased by ERα overexpression, whereas basal and induced luciferase activities by ERα overexpression were not influenced by β-estradiol. Effects of ERα overexpression were abrogated by 2 bp mutations in either the cAMP response element (CRE) or activator protein 1 (AP1)/glucocorticoid response element (GRE). Gel shift analyses showed that ERα overexpression increased binding to the CRE and AP1/GRE elements. Notably, the CRE-protein complexes were disrupted by ERα, CREB and phospho-CREB antibodies. The AP1/GRE-protein complexes were supershifted by the c-Fos antibody. These studies demonstrate that ERα stimulates BSP gene transcription in a ligand-independent manner by targeting the CRE and AP1/GRE elements in the rat BSP gene promoter. Copyright © 2014 Elsevier B.V. All rights reserved.

Dynamic DNA cytosine methylation in the Populus trichocarpa genome: tissue-level variation and relationship to gene expression

PubMed Central

2012-01-01

Background DNA cytosine methylation is an epigenetic modification that has been implicated in many biological processes. However, large-scale epigenomic studies have been applied to very few plant species, and variability in methylation among specialized tissues and its relationship to gene expression is poorly understood. Results We surveyed DNA methylation from seven distinct tissue types (vegetative bud, male inflorescence [catkin], female catkin, leaf, root, xylem, phloem) in the reference tree species black cottonwood (Populus trichocarpa). Using 5-methyl-cytosine DNA immunoprecipitation followed by Illumina sequencing (MeDIP-seq), we mapped a total of 129,360,151 36- or 32-mer reads to the P. trichocarpa reference genome. We validated MeDIP-seq results by bisulfite sequencing, and compared methylation and gene expression using published microarray data. Qualitative DNA methylation differences among tissues were obvious on a chromosome scale. Methylated genes had lower expression than unmethylated genes, but genes with methylation in transcribed regions ("gene body methylation") had even lower expression than genes with promoter methylation. Promoter methylation was more frequent than gene body methylation in all tissues except male catkins. Male catkins differed in demethylation of particular transposable element categories, in level of gene body methylation, and in expression range of genes with methylated transcribed regions. Tissue-specific gene expression patterns were correlated with both gene body and promoter methylation. Conclusions We found striking differences among tissues in methylation, which were apparent at the chromosomal scale and when genes and transposable elements were examined. In contrast to other studies in plants, gene body methylation had a more repressive effect on transcription than promoter methylation. PMID:22251412

A Comparative Analysis on Two Types of Oral Implants, Bone-Level and Tissue-Level, with Different Cantilever Lengths of Fixed Prosthesis.

PubMed

Mosavar, Alireza; Nili, Monireh; Hashemi, Sayed Raouf; Kadkhodaei, Mahmoud

2017-06-01

Depending on esthetic, anatomical, and functional aspects, in implant-prosthetic restoration of a completely edentulous jaw, the selection of implant type is highly important; however, bone- and tissue-level implants and their stress distribution in bone have not yet been comparatively investigated. Hence, finite element analysis was used to study the influence of cantilever length in a fixed prosthesis on stress distribution in peri-implant bone around these two types of oral implants. A 3D edentulous mandible was modeled. In simulations, a framework with four posterior cantilever lengths and two types of implants, bone-level and tissue-level, was considered. A compressive load was applied to the distal regions of the cantilevers, and the von-Mises stress of peri-implant bone was investigated. The independent t-test and the Pearson correlation coefficient analyzed the results (α = 0.05). Stresses in the cortical bone around the bone-level implants were greater than those in the tissue-level implants with the same cantilever length. In addition, by extending the cantilever length, the stress values in peri-implant bone increased. Therefore, when the cantilever was at its maximum length, the maximum stress was in cortical bone and around the bone-level distal implants. The results of the present study indicate that treatment with tissue-level implants is potentially more advantageous than with bone-level implants for implant-supported fixed prostheses. © 2015 by the American College of Prosthodontists.

Discrimination of lichen genera and species using element concentrations

USGS Publications Warehouse

Bennett, James P.

2008-01-01

The importance of organic chemistry in the classification of lichens is well established, but inorganic chemistry has been largely overlooked. Six lichen species were studied over a period of 23 years that were growing in 11 protected areas of the northern Great Lakes ecoregion, which were not greatly influenced by anthropogenic particulates or gaseous air pollutants. The elemental data from these studies were aggregated in order to test the hypothesis that differences among species in tissue element concentrations were large enough to discriminate between taxa faithfully. Concentrations of 16 chemical elements that were found in tissue samples from Cladonia rangiferina, Evernia mesomorpha, Flavopunctelia flaventior, Hypogymnia physodes, Parmelia sulcata, and Punctelia rudecta were analyzed statistically using multivariate discriminant functions and CART analyses, as well as t-tests. Genera and species were clearly separated in element space, and elemental discriminant functions were able to classify 91-100 of the samples correctly into species. At the broadest level, a Zn concentration of 51 ppm in tissues of four of the lichen species effectively discriminated foliose from fruticose species. Similarly, a S concentration of 680 ppm discriminated C. rangiferina and E. mesomorpha, and a Ca concentration of 10 436 ppm discriminated H. physodes from P. sulcata. For the three parmelioid species, a Ca concentration >32 837 ppm discriminated Punctelia rudecta from the other two species, while a Zn concentration of 56 ppm discriminated Parmelia sulcata from F. flaventior. Foliose species also had higher concentrations than did fruticose species of all elements except Na. Elemental signatures for each of the six species were developed using standardized means. Twenty-four mechanisms explaining the differences among species are summarized. Finally, the relationships of four species based on element concentrations, using additive-trees clustering of a Euclidean-distance matrix, produced identical relationships as did analyses based on secondary product chemistry that used additive-trees clustering of a Jaccard similarity matrix. At least for these six species, element composition has taxonomic significance, and may be useful for discriminating other taxa.

A simple method for maintaining relative positions of separate tissue elements during processing for electron microscopy.

PubMed

Stirling, C A

1978-09-01

Molten (328 K) 20% gelatin is used as a 'glue' to hold together separate tissue elements or tissue elements that may be separated when cutting small blocks of tissue for plastic embedding. Standard aldehyde and osmium fixation, dehydration and epoxy embedding are compatible with this as is semi-thin sectioning for light microscopy or thin sectioning for electron microscopy.

Modulation of tissue repair by regeneration enhancer elements.

PubMed

Kang, Junsu; Hu, Jianxin; Karra, Ravi; Dickson, Amy L; Tornini, Valerie A; Nachtrab, Gregory; Gemberling, Matthew; Goldman, Joseph A; Black, Brian L; Poss, Kenneth D

2016-04-14

How tissue regeneration programs are triggered by injury has received limited research attention. Here we investigate the existence of enhancer regulatory elements that are activated in regenerating tissue. Transcriptomic analyses reveal that leptin b (lepb) is highly induced in regenerating hearts and fins of zebrafish. Epigenetic profiling identified a short DNA sequence element upstream and distal to lepb that acquires open chromatin marks during regeneration and enables injury-dependent expression from minimal promoters. This element could activate expression in injured neonatal mouse tissues and was divisible into tissue-specific modules sufficient for expression in regenerating zebrafish fins or hearts. Simple enhancer-effector transgenes employing lepb-linked sequences upstream of pro- or anti-regenerative factors controlled the efficacy of regeneration in zebrafish. Our findings provide evidence for 'tissue regeneration enhancer elements' (TREEs) that trigger gene expression in injury sites and can be engineered to modulate the regenerative potential of vertebrate organs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rope, S.K.; Pearson, L.C.

Two measurement techniques were employed to evaluate the feasibility of using lichens as in situ biomonitors of atmospheric pollution in a semiarid climate - trace element analysis and electrolyte leakage from cells. Trace element concentrations were generally higher in Lecanora melanophthalma (ram.) Ram. tissues than previously measured in sagebrush (Artemisia tridentata) and perennial grasses from the same locations, but lower than in soil. Lichens from an urban area (Idaho Falls) had statistically higher concentrations of ten elements, particularly lead and zinc, than those from the Idaho National Engineering Laboratory (INEL) and Craters of the Moon National Monument. Levels of fluoride,more » nickel, and seven other elements were high at the INEL relative to the other sites. Thalli collected downwind from the Idaho Chemical Processing Plant (ICPP) at the INEL were significantly higher in boron and lead content than those collected at crosswind locations: levels of eleven elements were significantly higher in lichens collected at 5 or 10 km from the ICPP than in those collected at 2 km. Electrolyte leakage was greatest from thalli collected in the nighttime downwind direction from the ICPP, even though daytime winds, which blow in the opposite direction, are more frequent, suggesting that in a semiarid climate, injury from atmospheric SO{sub 2} and NO{sub x} pollution in lichen tissues is greatest when the thalli are moist from morning dew or other sources. These results demonstrate that some lichen species, especially Lecanora melanophthalma, have potential for biomonitoring of atmospheric pollutants in the semiarid regions of the Intermountain West.« less

Chromium in urothelial carcinoma of the bladder.

PubMed

Golabek, Tomasz; Socha, Katarzyna; Kudelski, Jacek; Darewicz, Barbara; Markiewicz-Zukowska, Renata; Chlosta, Piotr; Borawska, Maria

2017-12-23

Many epidemiological and experimental studies report a strong role of chemical carcinogens in the etiology of bladder cancer. However, the involvement of heavy metals in tumourigenesis of urothelial carcinoma of the bladder has been poorly investigated. Therefore, the aim of this study was to examine the relationship between chromium (Cr) and bladder cancer. Chromium concentration in two 36-sample series of bladder cancer tissue and sera from patients with this neoplasm were matched with those of a control group. The amount of trace elements in every tissue sample was determined using atomic absorption spectrometry. This was correlated with tumour stage. While the median chromium concentration levels reached statistically higher values in the bladder cancer tissue, compared with the non-cancer tissue (99.632ng/g and 33.144ng/g, respectively; p<0.001), the median Cr levels in the sera of the patients with this carcinoma showed no statistical difference when compared to those of the control group (0.511μg/l and 0.710μg/l, respectively; p=0.408). The median levels of Cr in the bladder tissue, depending on the stage of the tumour, compared with the tissue without the neoplasm, observed the same relationship for both non-muscle invasive and muscle-invasive tumours (p<0.001 and p<0.01, respectively). This study shows that patients with urothelial carcinoma of the bladder had higher tissue Cr levels than people without tumour, while no difference was found in the Cr serum levels between the two groups of patients under investigation.

Finite element study of scaffold architecture design and culture conditions for tissue engineering.

PubMed

Olivares, Andy L; Marsal, Elia; Planell, Josep A; Lacroix, Damien

2009-10-01

Tissue engineering scaffolds provide temporary mechanical support for tissue regeneration and transfer global mechanical load to mechanical stimuli to cells through its architecture. In this study the interactions between scaffold pore morphology, mechanical stimuli developed at the cell microscopic level, and culture conditions applied at the macroscopic scale are studied on two regular scaffold structures. Gyroid and hexagonal scaffolds of 55% and 70% porosity were modeled in a finite element analysis and were submitted to an inlet fluid flow or compressive strain. A mechanoregulation theory based on scaffold shear strain and fluid shear stress was applied for determining the influence of each structures on the mechanical stimuli on initial conditions. Results indicate that the distribution of shear stress induced by fluid perfusion is very dependent on pore distribution within the scaffold. Gyroid architectures provide a better accessibility of the fluid than hexagonal structures. Based on the mechanoregulation theory, the differentiation process in these structures was more sensitive to inlet fluid flow than axial strain of the scaffold. This study provides a computational approach to determine the mechanical stimuli at the cellular level when cells are cultured in a bioreactor and to relate mechanical stimuli with cell differentiation.

Physics-based subsurface visualization of human tissue.

PubMed

Sharp, Richard; Adams, Jacob; Machiraju, Raghu; Lee, Robert; Crane, Robert

2007-01-01

In this paper, we present a framework for simulating light transport in three-dimensional tissue with inhomogeneous scattering properties. Our approach employs a computational model to simulate light scattering in tissue through the finite element solution of the diffusion equation. Although our model handles both visible and nonvisible wavelengths, we especially focus on the interaction of near infrared (NIR) light with tissue. Since most human tissue is permeable to NIR light, tools to noninvasively image tumors, blood vasculature, and monitor blood oxygenation levels are being constructed. We apply this model to a numerical phantom to visually reproduce the images generated by these real-world tools. Therefore, in addition to enabling inverse design of detector instruments, our computational tools produce physically-accurate visualizations of subsurface structures.

Trace-elements, methylmercury and metallothionein levels in Magellanic penguin (Spheniscus magellanicus) found stranded on the Southern Brazilian coast.

PubMed

Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tércia G; Fillmann, Gilberto

2015-07-15

Magellanic penguins have been reported as good biomonitors for several types of pollutants, including trace-elements. In this context, selenium (Se), total mercury, methylmercury, inorganic mercury (Hg(inorg)), cadmium (Cd) and lead (Pb), as well as metallothionein (MT) levels, were evaluated in the feathers, liver and kidney of juvenile Magellanic penguins found stranded along the coast of Southern Brazil. The highest concentrations of all trace-elements and methylmercury were found in internal organs. Concentrations of Cd and Se in feathers were extremely low in comparison with their concentrations in soft tissues. The results showed that both Se and MT are involved in the detoxification of trace-elements (Cd, Pb and Hg(inorg)) since statistically significant relationships were found in liver. Conversely, hepatic Se was shown to be the only detoxifying agent for methylmercury. Copyright © 2015 Elsevier Ltd. All rights reserved.

Porcine calbindin-D9k gene: expression in endometrium, myometrium, and placenta in the absence of a functional estrogen response element in intron A.

PubMed

Krisinger, J; Jeung, E B; Simmen, R C; Leung, P C

1995-01-01

The expression of Calbindin-D9k (CaBP-9k) in the pig uterus and placenta was measured by Northern blot analysis and reverse transcription polymerase chain reaction (PCR), respectively. Progesterone (P4) administration to ovariectomized pigs decreased CaBP-9k mRNA levels. Expression of endometrial CaBP-9k mRNA was high on pregnancy Days 10-12 and below the detection limit on Days 15 and 18. On Day 60, expression could be detected at low levels. In myometrium and placenta, CaBP-9k mRNA expression was not detectable by Northern analysis using total RNA. Reverse-transcribed RNA from both tissues demonstrated the presence of CaBP-9k transcripts by means of PCR. The partial CaBP-9k gene was amplified by PCR and cloned to determine the sequence of intron A. In contrast to the rat CaBP-9k gene, the pig gene does not contain a functional estrogen response element (ERE) within this region. A similar ERE-like sequence located at the identical location was examined by gel retardation analysis and failed to bind the estradiol receptor. A similar disruption of this ERE-like sequence has been described in the human CaBP-9k gene, which is not expressed at any level in placenta, myometrium, or endometrium. It is concluded that the pig CaBP-9k gene is regulated in these reproductive tissues in a manner distinct from that in rat and human tissues. The regulation is probably due to a regulatory region outside of intron A, which in the rat gene contains the key cis element for uterine expression of the CaBP-9k gene.

Medical geochemistry research in Spissko-Gemerské rudohorie Mts., Slovakia.

PubMed

Rapant, S; Cvecková, V; Dietzová, Z; Khun, M; Letkovicová, M

2009-02-01

This study presents an assessment of the potential impact of geological contamination of the environment on the health of the population in Spissko-Gemerské rudohorie Mts. (SGR Mts.). The concentration levels of potentially toxic elements (mainly As, Cd, Cu, Hg, Pb, Sb, and Zn) were determined in soils, groundwater, surface water, and stream sediments as well as in the food chain (locally grown vegetables). A medical study included some 30 health indicators for all 98 municipalities of the study area. The As and Sb contents in human fluids and tissues were analyzed in one municipality identified to be at the highest risk. Based on element content, environmental and health risks were calculated for respective municipalities. Out of 98 municipalities 14 were characterized with extremely high environmental risk and 10 were characterized with very high carcinogenic risk from arsenic (groundwater). Extensive statistical analysis of geochemical data (element contents in soils, groundwater, surface water, and stream sediments) and health indicators was performed. Significant correlations between element contents in the geological environment and health indicators, mainly cancer and cardiovascular diseases, were identified. Biological monitoring has confirmed the transfer of elements from the geological environment to human fluids and tissues as well as to the local food chain.

Mercury species, selenium, metallothioneins and glutathione in two dolphins from the southeastern Brazilian coast: Mercury detoxification and physiological differences in diving capacity.

PubMed

Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tercia G; Pinheiro, Ana Beatriz; Di Beneditto, Ana Paula M

2016-06-01

In the present study, the concentration of trace elements, total mercury (Hg) and selenium (Se) and mercury forms (MeHg, Hginorg and HgSe) in the vulnerable coastal dolphins Pontoporia blainvillei and Sotalia guianensis were appraised and compared, using metallothioneins (MT) and glutathione (GSH) as biomarkers for trace element exposure. The trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher Hg and Se concentrations than those found in muscle. Hg, MeHg and Hginorg molar concentrations showed a clear increase with Se molar concentrations in the liver of both dolphins, and Se concentrations were higher than those of Hg on a molar basis. Se plays a relevant role in the detoxification of MeHg in the hepatic tissue of both dolphins, forming Hg-Se amorphous crystals in liver. In contrast, MT were involved in the detoxification process of Hginorg in liver. GSH levels in P. blainvillei and S. guianensis muscle tissue suggest that these dolphins have different diving capacities. Muscle Hg concentrations were associated to this tripeptide, which protects dolphin cells against Hg stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vanadium and Plant Nutrition

PubMed Central

Welch, Ross M.; Huffman, Edward W. D.

1973-01-01

Lettuce (Lactuca sativa L.) and tomato (Lycopersicon esculentum Mill.) plants were grown in purified nutrient solutions with and without the addition of 50 nanograms per milliliter V. These experiments showed that lettuce and tomato plants can be grown to maturity on nutrient solutions containing less than 0.04 nanogram per milliliter V with tissue concentrations of less than 2 to 18 nanograms per gram V. Growth and dry matter yield were comparable to those of plants grown on nutrient solutions containing 50 nanograms per milliliter with tissue levels of V from 117 to 418 nanograms per gram. Thus if V is an essential element for lettuce and tomato plants, the adequate tissue level would be less than 2 nanograms per gram V derivable from a growth medium containing less than 0.04 nanogram per milliliter V. PMID:16658525

μX-ray fluorescence analysis of traces and calcium phosphate phases on tooth tartar interfaces using synchrotron radiation

NASA Astrophysics Data System (ADS)

Abraham, J. A.; Grenón, M. S.; Sánchez, H. J.; Valentinuzzi, M. C.; Perez, C. A.

2007-07-01

Hard dental tissues like dentine and cementum with calcified deposits (dental calculi) were studied in several human dental pieces of adult individuals from the same geographic region. A couple of cross cuts were performed at dental root level resulting in a planar slice with calculus and dental tissue exposed for analysis. The elemental content along a linear path crossing the dentine-cementum-tartar interfaces and also all over a surface was measured by X-ray fluorescence microanalysis using synchrotron radiation (μSRXRF). The concentration of elemental traces like K, V, Cu, Zn, As, Br and Sr showed different features on the analyzed regions. The possible connections with the dynamic of mineralization and biological implications are discussed. The concentrations of major elements Ca and P were also determined and the measured Ca/P molar ratio was used to estimate the average composition of calcium phosphate phases in the measured points. A deeper knowledge of the variations of the elemental compositions and the changes of the different phases will help to a better understanding of the scarcely known mechanism of calculus growing.

Node-controlled allocation of mineral elements in Poaceae.

PubMed

Yamaji, Naoki; Ma, Jian Feng

2017-10-01

Mineral elements taken up by the roots will be delivered to different organs and tissues depending on their requirements. In Poaceae, this selective distribution is mainly mediated in the nodes, which have highly developed and fully organized vascular systems. Inter-vascular transfer of mineral elements from enlarged vascular bundles to diffuse vascular bundles is required for their preferential distribution to developing tissues and reproductive organs. A number of transporters involved in this inter-vascular transfer processes have been identified mainly in rice. They are localized at the different cell layers and form an efficient machinery within the node. Furthermore, some these transporters show rapid response to the environmental changes of mineral elements at the protein level. In addition to the node-based transporters, distinct nodal structures including enlarged xylem area, folded plasma membrane of xylem transfer cells and presence of an apoplastic barrier are also required for the efficient inter-vascular transfer. Manipulation of node-based transporters will provide a novel breeding target to improve nutrient use efficiency, productivity, nutritional value and safety in cereal crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

Regenerative Endodontics: A Road Less Travelled

PubMed Central

Bansal, Ramta; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

2014-01-01

Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients’ quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering. PMID:25478476

Isolation of 4-coumarate Co-A ligase gene promoter from loblolly pine (Pinus taeda) and characterization of tissue-specific activity in transgenic tobacco.

PubMed

Osakabe, Yuriko; Osakabe, Keishi; Chiang, Vincent L

2009-01-01

We characterized promoter activity of a phenylpropanoid biosynthetic gene encoding 4-coumarate Co-A ligase (4CL), Pta4Clalpha, from Pinus taeda. Histochemical- and quantitative assays of GUS expression in the vascular tissue were performed using transgenic tobacco plants expressing promoter-GUS reporters. Deletion analysis of the Pta4Clalpha promoter showed that the region -524 to -252, which has two AC elements, controls the high expression levels in ray-parenchyma cells of older tobacco stems. High activity level of the promoter domain of Pta4CLalpha was also detected in the xylem cells under bending stress. DNA-protein complexes were detected in the reactions of the Pta4CLalpha promoter fragments with the nuclear proteins of xylem of P. taeda. The AC elements in the Pta4CLalpha promoter appeared to have individual roles during xylem development that are activated in a coordinated manner in response to stress in transgenic tobacco.

Hepatic and renal trace element concentrations in American alligators (Alligator mississippiensis) following chronic dietary exposure to coal fly ash contaminated prey.

PubMed

Tuberville, Tracey D; Scott, David E; Metts, Brian S; Finger, John W; Hamilton, Matthew T

2016-07-01

Little is known about the propensity of crocodilians to bioaccumulate trace elements as a result of chronic dietary exposure. We exposed 36 juvenile alligators (Alligator mississippiensis) to one of four dietary treatments that varied in the relative frequency of meals containing prey from coal combustion waste (CCW)-contaminated habitats vs. prey from uncontaminated sites, and evaluated tissue residues and growth rates after 12 mo and 25 mo of exposure. Hepatic and renal concentrations of arsenic (As), cadmium (Cd) and selenium (Se) varied significantly among dietary treatment groups in a dose-dependent manner and were higher in kidneys than in livers. Exposure period did not affect Se or As levels but Cd levels were significantly higher after 25 mo than 12 mo of exposure. Kidney As and Se levels were negatively correlated with body size but neither growth rates nor body condition varied significantly among dietary treatment groups. Our study is among the first to experimentally examine bioaccumulation of trace element contaminants in crocodilians as a result of chronic dietary exposure. A combination of field surveys and laboratory experiments will be required to understand the effects of different exposure scenarios on tissue residues, and ultimately link these concentrations with effects on individual health. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effects of di(2-ethylhexyl) phthalate and/or selenium on trace element levels in different organs of rats.

PubMed

Erkekoglu, Pinar; Arnaud, Josiane; Rachidi, Walid; Kocer-Gumusel, Belma; Favier, Alain; Hincal, Filiz

2015-01-01

Di(2-ethylhexyl)phthalate (DEHP), a widely used plasticizer for synthetic polymers, is known to have endocrine disruptive potential, reproductive toxicity, and induces hepatic carcinogenesis in rodents. Selenium (Se) is a component of several selenoenzymes which are essential for cellular antioxidant defense and for the functions of mammalian reproductive system. The present study was designed to investigate the effects of DEHP exposure on trace element distribution in liver, testis, and kidney tissues and plasma of Se-deficient and Se-supplemented rats. Se deficiency was produced by feeding 3-week old Sprague-Dawley rats with ≤0.05mg Se/kg diet for 5 weeks, and supplementation group were on 1mg Se/kg diet. DEHP treated groups received 1000mg/kg dose by gavage during the last 10 days of feeding period. Se, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) levels were measured by inductively coupled plasma mass spectrometry (ICP-MS). Se supplementation caused significant increases in hepatic, renal, and testicular Se levels. With DEHP exposure, plasma Se and Zn, kidney Se, Cu and Mn levels were significantly decreased. Besides, liver Fe decreased markedly in all the DEHP-treated groups. Liver and kidney Mn levels decreased significantly in DEHP/SeD group compared to both DEHP and SeD groups. These results showed the potential of DEHP exposure and/or different Se status to modify the distribution pattern of essential trace elements in various tissues, the importance of which needs to be further evaluated. Copyright © 2014. Published by Elsevier GmbH.

Characterization of the quality of water, bed sediment, and fish in Mittry Lake, Arizona, 2014–15

USGS Publications Warehouse

Hermosillo, Edyth; Coes, Alissa L.

2017-03-01

Water, bed-sediment, and fish sampling was conducted in Mittry Lake, Arizona, in 2014–15 to establish current water-quality conditions of the lake. The parameters of temperature, dissolved-oxygen concentration, specific conductance, and alkalinity were measured in the field. Water samples were collected and analyzed for dissolved major ions, dissolved trace elements, dissolved nutrients, dissolved organic carbon, dissolved pesticides, bacteria, and suspended-sediment concentrations. Bed-sediment and fish samples were analyzed for trace elements, halogenated compounds, total mercury, and methylmercury.U.S. Environmental Protection Agency secondary maximum contaminant levels in drinking water were exceeded for sulfate, chloride, and manganese in the water samples. Trace-element concentrations were relatively similar between the inlet, middle, and outlet locations. Concentrations for nutrients in all water samples were below the Arizona Department of Environmental Quality’s water-quality standards for aquatic and wildlife uses, and all bacteria levels were below the Arizona Department of Environmental Quality’s recommended recreational water-quality criteria. Three out of 81 pesticides were detected in the water samples.Trace-element concentrations in bed sediment were relatively consistent between the inlet, middle, and outlet locations. Lead, manganese, nickel, and zinc concentrations, however, decreased from the inlet to outlet locations. Concentrations for lead, nickel, and zinc in some bed-sediment samples exceeded consensus-based sediment-quality guidelines probable effect concentrations. Eleven out of 61 halogenated compounds were detected in bed sediment at the inlet location, whereas three were detected at the middle location, and five were detected at the outlet location. No methylmercury was detected in bed sediment. Total mercury was detected in bed sediment at concentrations below the consensus-based sediment-quality guidelines probable effect concentration.Sixteen trace elements were detected in at least one of the fish-tissue samples, and trace-element concentrations were relatively consistent between the three fish-tissue samples. Seven halogenated compounds were detected in at least one of the whole-body fish samples; four to five compounds were detected in each fish. One fish-tissue sample exceeded the U.S. Environmental Protection Agency human health consumption criteria for methylmercury.

X-ray elemental mapping techniques for elucidating the ecophysiology of hyperaccumulator plants.

PubMed

van der Ent, Antony; Przybyłowicz, Wojciech J; de Jonge, Martin D; Harris, Hugh H; Ryan, Chris G; Tylko, Grzegorz; Paterson, David J; Barnabas, Alban D; Kopittke, Peter M; Mesjasz-Przybyłowicz, Jolanta

2018-04-01

Contents Summary 432 I. Introduction 433 II. Preparation of plant samples for X-ray micro-analysis 433 III. X-ray elemental mapping techniques 438 IV. X-ray data analysis 442 V. Case studies 443 VI. Conclusions 446 Acknowledgements 449 Author contributions 449 References 449 SUMMARY: Hyperaccumulators are attractive models for studying metal(loid) homeostasis, and probing the spatial distribution and coordination chemistry of metal(loid)s in their tissues is important for advancing our understanding of their ecophysiology. X-ray elemental mapping techniques are unique in providing in situ information, and with appropriate sample preparation offer results true to biological conditions of the living plant. The common platform of these techniques is a reliance on characteristic X-rays of elements present in a sample, excited either by electrons (scanning/transmission electron microscopy), protons (proton-induced X-ray emission) or X-rays (X-ray fluorescence microscopy). Elucidating the cellular and tissue-level distribution of metal(loid)s is inherently challenging and accurate X-ray analysis places strict demands on sample collection, preparation and analytical conditions, to avoid elemental redistribution, chemical modification or ultrastructural alterations. We compare the merits and limitations of the individual techniques, and focus on the optimal field of applications for inferring ecophysiological processes in hyperaccumulator plants. X-ray elemental mapping techniques can play a key role in answering questions at every level of metal(loid) homeostasis in plants, from the rhizosphere interface, to uptake pathways in the roots and shoots. Further improvements in technological capabilities offer exciting perspectives for the study of hyperaccumulator plants into the future. © 2017 University of Queensland. New Phytologist © 2017 New Phytologist Trust.

A novel role for CRTC2 in hepatic cholesterol synthesis through SREBP‐2

PubMed Central

Li, Yujie; Song, Yongfeng; Zhao, Meng; Guo, Yanjing; Yu, Chunxiao; Chen, Wenbin; Shao, Shanshan; Xu, Chao; Zhou, Xinli; Zhao, Lifang; Zhang, Zhenhai; Bo, Tao; Xia, Yu; Proud, Christopher G.; Wang, Xuemin; Wang, Li; Zhao, Jiajun

2017-01-01

Cholesterol synthesis is regulated by the transcription factor sterol regulatory element binding protein 2 (SREBP‐2) and its target gene 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMGCR), which is the rate‐limiting enzyme in cholesterol synthesis. Cyclic adenosine monophosphate–responsive element (CRE) binding protein–regulated transcription coactivator (CRTC) 2 is the master regulator of glucose metabolism. However, the effect of CRTC2 on cholesterol and its potential molecular mechanism remain unclear. Here, we demonstrated that CRTC2 expression and liver cholesterol content were increased in patients with high serum cholesterol levels who underwent resection of liver hemangiomas, as well as in mice fed a 4% cholesterol diet. Mice with adenovirus‐mediated CRTC2 overexpression also showed elevated lipid levels in both serum and liver tissues. Intriguingly, hepatic de novo cholesterol synthesis was markedly increased under these conditions. In contrast, CRTC2 ablation in mice fed a 4% cholesterol diet (18 weeks) showed decreased lipid levels in serum and liver tissues compared with those in littermate wild‐type mice. The expression of lipogenic genes (SREBP‐2 and HMGCR) was consistent with hepatic CRTC2 levels. In vivo imaging showed enhanced adenovirus‐mediated HMGCR‐luciferase activity in adenovirus‐mediated CRTC2 mouse livers; however, the activity was attenuated after mutation of CRE or sterol regulatory element sequences in the HMGCR reporter construct. The effect of CRTC2 on HMGCR in mouse livers was alleviated upon SREBP‐2 knockdown. CRTC2 modulated SREBP‐2 transcription by CRE binding protein, which recognizes the half‐site CRE sequence in the SREBP‐2 promoter. CRTC2 reduced the nuclear protein expression of forkhead box O1 and subsequently increased SREBP‐2 transcription by binding insulin response element 1, rather than insulin response element 2, in the SREBP‐2 promoter. Conclusion: CRTC2 regulates the transcription of SREBP‐2 by interfering with the recognition of insulin response element 1 in the SREBP‐2 promoter by forkhead box O1, thus inducing SREBP‐2/HMGCR signaling and subsequently facilitating hepatic cholesterol synthesis. (Hepatology 2017;66:481–497). PMID:28395113

Selected elements and organic chemicals in streambed sediment in the Salem area, Oregon, 1999

USGS Publications Warehouse

Tanner, Dwight Q.

2002-09-13

The high levels of contaminants in some Salem area streams indicates the need for further study to assess the biological effects of these contaminants. Future monitoring in the Salem area could include bioassays using benthic invertebrates and the measurement of organochlorine compounds, including DDT, DDE, DDD, and dieldrin in fish tissue. Because resident fish may be consumed by humans and wildlife, fish tissue analyses would be helpful to determine the health risk associated with fish consumption.

A comprehensive model of the spatio-temporal stem cell and tissue organisation in the intestinal crypt.

PubMed

Buske, Peter; Galle, Jörg; Barker, Nick; Aust, Gabriela; Clevers, Hans; Loeffler, Markus

2011-01-06

We introduce a novel dynamic model of stem cell and tissue organisation in murine intestinal crypts. Integrating the molecular, cellular and tissue level of description, this model links a broad spectrum of experimental observations encompassing spatially confined cell proliferation, directed cell migration, multiple cell lineage decisions and clonal competition.Using computational simulations we demonstrate that the model is capable of quantitatively describing and predicting the dynamic behaviour of the intestinal tissue during steady state as well as after cell damage and following selective gain or loss of gene function manipulations affecting Wnt- and Notch-signalling. Our simulation results suggest that reversibility and flexibility of cellular decisions are key elements of robust tissue organisation of the intestine. We predict that the tissue should be able to fully recover after complete elimination of cellular subpopulations including subpopulations deemed to be functional stem cells. This challenges current views of tissue stem cell organisation.

Database construction for PromoterCAD: synthetic promoter design for mammals and plants.

PubMed

Nishikata, Koro; Cox, Robert Sidney; Shimoyama, Sayoko; Yoshida, Yuko; Matsui, Minami; Makita, Yuko; Toyoda, Tetsuro

2014-03-21

Synthetic promoters can control a gene's timing, location, and expression level. The PromoterCAD web server ( http://promotercad.org ) allows the design of synthetic promoters to control plant gene expression, by novel arrangement of cis-regulatory elements. Recently, we have expanded PromoterCAD's scope with additional plant and animal data: (1) PLACE (Plant Cis-acting Regulatory DNA Elements), including various sized sequence motifs; (2) PEDB (Mammalian Promoter/Enhancer Database), including gene expression data for mammalian tissues. The plant PromoterCAD data now contains 22 000 Arabidopsis thaliana genes, 2 200 000 microarray measurements in 20 growth conditions and 79 tissue organs and developmental stages, while the new mammalian PromoterCAD data contains 679 Mus musculus genes and 65 000 microarray measurements in 96 tissue organs and cell types ( http://promotercad.org/mammal/ ). This work presents step-by-step instructions for adding both regulatory motif and gene expression data to PromoterCAD, to illustrate how users can expand PromoterCAD functionality for their own applications and organisms.

Organic compounds and trace elements in fish tissue and bed sediment from streams in the Yellowstone River basin, Montana and Wyoming, 1998

USGS Publications Warehouse

Peterson, David A.; Boughton, Gregory K.

2000-01-01

A comprehensive water-quality investigation of the Yellowstone River Basin began in 1997, under the National Water-Quality Assessment (NAWQA) Program. Twenty-four sampling sites were selected for sampling of fish tissue and bed sediment during 1998. Organic compounds analyzed included organochlorine insecticides and their metabolites and total polychlorinated biphenyls (PCBs) from fish-tissue and bed-sediment samples, and semivolatile organic compounds from bed-sediment samples. A broad suite of trace elements was analyzed from both fish-tissue and bed-sediment samples, and a special study related to mercury also was conducted. Of the 12 organochlorine insecticides and metabolites detected in the fish-tissue samples, the most compounds per site were detected in samples from integrator sites which represent a mixture of land uses. The presence of DDT, and its metabolites DDD and DDE, in fish collected in the Yellowstone Park area likely reflects long-term residual effects from historical DDT-spraying programs for spruce budworm. Dieldrin, chlordane, and other organic compounds also were detected in the fish-tissue samples. The compound p, p'-DDE was detected at 71 percent of the sampling sites, more than any other compound. The concentrations of total DDT in fish samples were low, however, compared to concentrations from historical data from the study area, other NAWQA studies in the Rocky Mountains, and national baseline concentrations. Only 2 of the 27 organochlorine insecticides and metabolites and total PCBs analyzed in bed sediment were detected. Given that 12 of the compounds were detected in fish-tissue samples, fish appeared to be more sensitive indicators of contamination than bed sediment.Concentrations of some trace elements in fish and bed sediment were higher at sites in mineralized areas than at other sites. Concentrations of selenium in fish tissue from some sites were above background levels. Concentrations of arsenic, chromium, copper, and lead in some of the bed-sediment samples potentially exceeded criteria for the protection of aquatic life.

Optimization of tissue physical parameters for accurate temperature estimation from finite-element simulation of radiofrequency ablation.

PubMed

Subramanian, Swetha; Mast, T Douglas

2015-10-07

Computational finite element models are commonly used for the simulation of radiofrequency ablation (RFA) treatments. However, the accuracy of these simulations is limited by the lack of precise knowledge of tissue parameters. In this technical note, an inverse solver based on the unscented Kalman filter (UKF) is proposed to optimize values for specific heat, thermal conductivity, and electrical conductivity resulting in accurately simulated temperature elevations. A total of 15 RFA treatments were performed on ex vivo bovine liver tissue. For each RFA treatment, 15 finite-element simulations were performed using a set of deterministically chosen tissue parameters to estimate the mean and variance of the resulting tissue ablation. The UKF was implemented as an inverse solver to recover the specific heat, thermal conductivity, and electrical conductivity corresponding to the measured area of the ablated tissue region, as determined from gross tissue histology. These tissue parameters were then employed in the finite element model to simulate the position- and time-dependent tissue temperature. Results show good agreement between simulated and measured temperature.

Comprehensive evaluation of disease- and trait-specific enrichment for eight functional elements among GWAS-identified variants.

PubMed

Markunas, Christina A; Johnson, Eric O; Hancock, Dana B

2017-07-01

Genome-wide association study (GWAS)-identified variants are enriched for functional elements. However, we have limited knowledge of how functional enrichment may differ by disease/trait and tissue type. We tested a broad set of eight functional elements for enrichment among GWAS-identified SNPs (p < 5×10 -8 ) from the NHGRI-EBI Catalog across seven disease/trait categories: cancer, cardiovascular disease, diabetes, autoimmune disease, psychiatric disease, neurological disease, and anthropometric traits. SNPs were annotated using HaploReg for the eight functional elements across any tissue: DNase sites, expression quantitative trait loci (eQTL), sequence conservation, enhancers, promoters, missense variants, sequence motifs, and protein binding sites. In addition, tissue-specific annotations were considered for brain vs. blood. Disease/trait SNPs were compared to a control set of 4809 SNPs matched to the GWAS SNPs (N = 1639) on allele frequency, gene density, distance to nearest gene, and linkage disequilibrium at ~3:1 ratio. Enrichment analyses were conducted using logistic regression, with Bonferroni correction. Overall, a significant enrichment was observed for all functional elements, except sequence motifs. Missense SNPs showed the strongest magnitude of enrichment. eQTLs were the only functional element significantly enriched across all diseases/traits. Magnitudes of enrichment were generally similar across diseases/traits, where enrichment was statistically significant. Blood vs. brain tissue effects on enrichment were dependent on disease/trait and functional element (e.g., cardiovascular disease: eQTLs P TissueDifference  = 1.28 × 10 -6 vs. enhancers P TissueDifference  = 0.94). Identifying disease/trait-relevant functional elements and tissue types could provide new insight into the underlying biology, by guiding a priori GWAS analyses (e.g., brain enhancer elements for psychiatric disease) or facilitating post hoc interpretation.

Correlation of HIWI and HILI Expression with Cancer Stem Cell Markers in Colorectal Cancer.

PubMed

Litwin, Monika; Dubis, Joanna; Arczyńska, Katarzyna; Piotrowska, Aleksandra; Frydlewicz, Anna; Karczewski, Maciej; Dzięgiel, Piotr; Witkiewicz, Wojciech

2015-06-01

Cancer stem cells (CSCs) constitute a sub-population of tumor cells that possess stem cell properties, such as self-renewal and the ability of differentiation. The presence of CSCs is associated with metastatic potential, treatment resistance and poor patient prognosis. Recently, aberrant expression of P-element induced wimpy testis proteins-PIWI (HIWI and HILI) has been identified in various types of tumors. The aim of the study was to evaluate the clinical significance of the HIWI and HILI expression and its relationship with cancer stem cells markers in 72 patients with colorectal carcinoma (CRC). The expression level of HIWI and HILI and cancer stem cells markers in paired cancerous and non-cancerous tissues was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. Immunohistochemistry was performed to confirm the observed changes on mRNA level and detect tissue localization of PIWI proteins. Significantly higher mRNA levels of HIWI and decreased HILI mRNA were measured in colorectal cancer tissues compared to corresponding non-cancerous samples. The changes in HIWI mRNA level in cancer tissues were correlated with OCT4 expression. Positive correlations between HILI level and SOX2 were also observed in cancerous tissues. Our results indicate a reciprocal regulation between HIWI, HILI and some CSCs markers in colorectal cancer. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The development and deployment of Common Data Elements for tissue banks for translational research in cancer - an emerging standard based approach for the Mesothelioma Virtual Tissue Bank.

PubMed

Mohanty, Sambit K; Mistry, Amita T; Amin, Waqas; Parwani, Anil V; Pople, Andrew K; Schmandt, Linda; Winters, Sharon B; Milliken, Erin; Kim, Paula; Whelan, Nancy B; Farhat, Ghada; Melamed, Jonathan; Taioli, Emanuela; Dhir, Rajiv; Pass, Harvey I; Becich, Michael J

2008-04-08

Recent advances in genomics, proteomics, and the increasing demands for biomarker validation studies have catalyzed changes in the landscape of cancer research, fueling the development of tissue banks for translational research. A result of this transformation is the need for sufficient quantities of clinically annotated and well-characterized biospecimens to support the growing needs of the cancer research community. Clinical annotation allows samples to be better matched to the research question at hand and ensures that experimental results are better understood and can be verified. To facilitate and standardize such annotation in bio-repositories, we have combined three accepted and complementary sets of data standards: the College of American Pathologists (CAP) Cancer Checklists, the protocols recommended by the Association of Directors of Anatomic and Surgical Pathology (ADASP) for pathology data, and the North American Association of Central Cancer Registry (NAACCR) elements for epidemiology, therapy and follow-up data. Combining these approaches creates a set of International Standards Organization (ISO) - compliant Common Data Elements (CDEs) for the mesothelioma tissue banking initiative supported by the National Institute for Occupational Safety and Health (NIOSH) of the Center for Disease Control and Prevention (CDC). The purpose of the project is to develop a core set of data elements for annotating mesothelioma specimens, following standards established by the CAP checklist, ADASP cancer protocols, and the NAACCR elements. We have associated these elements with modeling architecture to enhance both syntactic and semantic interoperability. The system has a Java-based multi-tiered architecture based on Unified Modeling Language (UML). Common Data Elements were developed using controlled vocabulary, ontology and semantic modeling methodology. The CDEs for each case are of different types: demographic, epidemiologic data, clinical history, pathology data including block level annotation, and follow-up data including treatment, recurrence and vital status. The end result of such an effort would eventually provide an increased sample set to the researchers, and makes the system interoperable between institutions. The CAP, ADASP and the NAACCR elements represent widely established data elements that are utilized in many cancer centers. Herein, we have shown these representations can be combined and formalized to create a core set of annotations for banked mesothelioma specimens. Because these data elements are collected as part of the normal workflow of a medical center, data sets developed on the basis of these elements can be easily implemented and maintained.

The development and deployment of Common Data Elements for tissue banks for translational research in cancer – An emerging standard based approach for the Mesothelioma Virtual Tissue Bank

PubMed Central

Mohanty, Sambit K; Mistry, Amita T; Amin, Waqas; Parwani, Anil V; Pople, Andrew K; Schmandt, Linda; Winters, Sharon B; Milliken, Erin; Kim, Paula; Whelan, Nancy B; Farhat, Ghada; Melamed, Jonathan; Taioli, Emanuela; Dhir, Rajiv; Pass, Harvey I; Becich, Michael J

2008-01-01

Background Recent advances in genomics, proteomics, and the increasing demands for biomarker validation studies have catalyzed changes in the landscape of cancer research, fueling the development of tissue banks for translational research. A result of this transformation is the need for sufficient quantities of clinically annotated and well-characterized biospecimens to support the growing needs of the cancer research community. Clinical annotation allows samples to be better matched to the research question at hand and ensures that experimental results are better understood and can be verified. To facilitate and standardize such annotation in bio-repositories, we have combined three accepted and complementary sets of data standards: the College of American Pathologists (CAP) Cancer Checklists, the protocols recommended by the Association of Directors of Anatomic and Surgical Pathology (ADASP) for pathology data, and the North American Association of Central Cancer Registry (NAACCR) elements for epidemiology, therapy and follow-up data. Combining these approaches creates a set of International Standards Organization (ISO) – compliant Common Data Elements (CDEs) for the mesothelioma tissue banking initiative supported by the National Institute for Occupational Safety and Health (NIOSH) of the Center for Disease Control and Prevention (CDC). Methods The purpose of the project is to develop a core set of data elements for annotating mesothelioma specimens, following standards established by the CAP checklist, ADASP cancer protocols, and the NAACCR elements. We have associated these elements with modeling architecture to enhance both syntactic and semantic interoperability. The system has a Java-based multi-tiered architecture based on Unified Modeling Language (UML). Results Common Data Elements were developed using controlled vocabulary, ontology and semantic modeling methodology. The CDEs for each case are of different types: demographic, epidemiologic data, clinical history, pathology data including block level annotation, and follow-up data including treatment, recurrence and vital status. The end result of such an effort would eventually provide an increased sample set to the researchers, and makes the system interoperable between institutions. Conclusion The CAP, ADASP and the NAACCR elements represent widely established data elements that are utilized in many cancer centers. Herein, we have shown these representations can be combined and formalized to create a core set of annotations for banked mesothelioma specimens. Because these data elements are collected as part of the normal workflow of a medical center, data sets developed on the basis of these elements can be easily implemented and maintained. PMID:18397527

Trace-Element Concentrations in Tissues of Aquatic Organisms from Rivers and Streams of the United States, 1992-1999

USGS Publications Warehouse

DeWeese, Lawrence R.; Stephens, Verlin C.; Short, Terry M.; Dubrovsky, Neil M.

2007-01-01

The U.S. Geological Survey National Water-Quality Assessment Program collected tissue samples from a variety of aquatic organisms during 1992-1999 within 47 study units across the United States. These tissue samples were collected to determine the occurrence and distribution of 20 major and minor trace elements in aquatic organisms. This report presents the tissue trace-element concentration data, sample summaries, and concentration statistics for 1,457 tissue samples representing 76 species or groups of fish, aquatic invertebrates, and plants were collected at 824 sampling sites.

The reserpinized rat in the study of cystic fibrosis: x-ray microanalysis of submandibular gland and pancreas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roomans, G.M.; Wei, X.; Ceder, O.

The chronically reserpinized rat has been suggested as an animal model for cystic fibrosis. X-ray microanalysis of thick and thin cryosections was carried out to assess elemental redistribution in the submandibular glands and the pancreas of reserpinized rats at the cellular and subcellular level. In the submandibular gland of reserpinized rats, calcium and magnesium concentrations were significantly elevated. Mucus globules, secretory granules, and endoplasmic reticulum were the primary sites of the localization of excess calcium and magnesium. A significant potassium loss from the gland had occurred, particularly from the serous cells. Electron microscopy of conventionally prepared tissue showed marked swellingmore » of the endoplasmic reticulum, especially in mucous cells. The elemental changes in the pancreatic acinar cells of reserpinized rats were reminiscent of elemental redistribution connected with cell death: increased levels of sodium, chlorine, and calcium and decreased levels of magnesium and potassium. Ultrastructural changes included swelling of the endoplasmic reticulum and obstruction of the acinar lumen. It is concluded tha elemental redistribution in chronically reserpinized rats presents interesting parallels with cystic fibrosis.« less

Trace elements in organisms of different trophic groups in the White Sea

NASA Astrophysics Data System (ADS)

Budko, D. F.; Demina, L. L.; Martynova, D. M.; Gorshkova, O. M.

2015-09-01

Concentrations of trace elements (Fe, Mn, Cu, Pb, Ni, Cr, Cd, As, Co, and Se) have been studied in different trophic groups of organisms: primary producers (seston, presented mostly by phytoplankton), primary consumers (mesozooplankton, macrozooplankton, and bivalves), secondary consumers (predatory macrozooplankton and starfish), and consumers of higher trophic levels (fish species), inhabiting the coastal zone of Kandalaksha Bay and the White Sea (Cape Kartesh). The concentrations of elements differ significantly for the size groups of Sagitta elegans (zooplankton) and blue mussel Mytilus edulis, as well as for the bone and muscle tissues of studied fish species, Atlantic cod Gadus morhua marisalbi and Atlantic wolffish Anarhichas lupus. The concentrations of all the studied elements were lower among the primary consumers and producers, but increased again at higher trophic levels, from secondary consumers to tertiary consumers ("mesozooplankton → macrozooplankton Sagitta elegans" and "mussels → starfish"). Ni and Pb tended to decline through the food chains seston→…→cod and mesozooplankton→…→stickleback. Only the concentrations of Fe increased in all the trophic chains along with the increase of the trophic level.

The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats.

PubMed

Piątkowska, Ewa; Kopeć, Aneta; Bieżanowska-Kopeć, Renata; Pysz, Mirosław; Kapusta-Duch, Joanna; Koronowicz, Aneta Agnieszka; Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Maślak, Edyta

2016-01-01

Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats' hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations.

The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats

PubMed Central

Piątkowska, Ewa; Kopeć, Aneta; Bieżanowska-Kopeć, Renata; Pysz, Mirosław; Kapusta-Duch, Joanna; Koronowicz, Aneta Agnieszka; Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Maślak, Edyta

2016-01-01

Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats’ hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations. PMID:27043135

Glycine betaine accumulation, ionic and water relations of red-beet at contrasting levels of sodium supply

NASA Technical Reports Server (NTRS)

Subbarao, G. V.; Wheeler, R. M.; Levine, L. H.; Stutte, G. W.; Sager, J. C. (Principal Investigator)

2001-01-01

Exposure of plants to sodium (Na) and salinity may increase glycine betaine accumulation in tissues. To study this, red-beet cvs. Scarlet Supreme and Ruby Queen, were grown for 42 days in a growth chamber using a re-circulating nutrient film technique with 0.25 mmol/L K and either 4.75 mmol/L (control) or 54.75 mmol/L (saline) Na (as NaCl). Plants were harvested at weekly intervals and measurements were taken on leaf water relations, leaf photosynthetic rates, chlorophyll fluorescence, chlorophyll levels, glycine betaine levels, and tissue elemental composition. Glycine betaine accumulation increased under salinity and this accumulation correlated with higher tissue levels of Na in both cultivars. Na accounted for 80 to 90% of the total cation uptake under the saline treatment. At final harvest (42 days), K concentrations in laminae ranged from approximately 65-95 micromoles g-1 dry matter (DM), whereas Na in shoot tissue ranged from approximately 3000-4000 micromoles g-1. Leaf sap osmotic potential at full turgor [psi(s100)] increased as lamina Na content increased. Glycine betaine levels of leaf laminae showed a linear relationship with leaf sap [psi(s100)]. Chlorophyll levels, leaf photosynthetic rates, and chlorophyll fluorescence were not affected by Na levels. These results suggest that the metabolic tolerance to high levels of tissue Na in red-beet could be due to its ability to synthesize and regulate glycine betaine production, and to control partitioning of Na and glycine betaine between the vacuole and the cytoplasm.

Discrimination of lichen genera and species using element concentrations

USGS Publications Warehouse

Bennett, J.P.

2008-01-01

The importance of organic chemistry in the classification of lichens is well established, but inorganic chemistry has been largely overlooked. Six lichen species were studied over a period of 23 years that were growing in 11 protected areas of the northern Great Lakes ecoregion, which were not greatly influenced by anthropogenic particulates or gaseous air pollutants. The elemental data from these studies were aggregated in order to test the hypothesis that differences among species in tissue element concentrations were large enough to discriminate between taxa faithfully. Concentrations of 16 chemical elements that were found in tissue samples from Cladonia rangiferina, Evernia mesomorpha, Flavopunctelia flaventior, Hypogymnia physodes, Parmelia sulcata, and Punctelia rudecta were analyzed statistically using multivariate discriminant functions and CART analyses, as well as t-tests. Genera and species were clearly separated in element space, and elemental discriminant functions were able to classify 91-100 of the samples correctly into species. At the broadest level, a Zn concentration of 51 ppm in tissues of four of the lichen species effectively discriminated foliose from fruticose species. Similarly, a S concentration of 680 ppm discriminated C. rangiferina and E. mesomorpha, and a Ca concentration of 10 436 ppm discriminated H. physodes from P. sulcata. For the three parmelioid species, a Ca concentration >32 837 ppm discriminated Punctelia rudecta from the other two species, while a Zn concentration of 56 ppm discriminated Parmelia sulcata from F. flaventior. Foliose species also had higher concentrations than did fruticose species of all elements except Na. Elemental signatures for each of the six species were developed using standardized means. Twenty-four mechanisms explaining the differences among species are summarized. Finally, the relationships of four species based on element concentrations, using additive-trees clustering of a Euclidean-distance matrix, produced identical relationships as did analyses based on secondary product chemistry that used additive-trees clustering of a Jaccard similarity matrix. At least for these six species, element composition has taxonomic significance, and may be useful for discriminating other taxa. ?? 2008 British Lichen Society.

Tracing Cationic Nutrients from Xylem into Stem Tissue of French Bean by Stable Isotope Tracers and Cryo-Secondary Ion Mass Spectrometry[W][OA

PubMed Central

Metzner, Ralf; Schneider, Heike Ursula; Breuer, Uwe; Thorpe, Michael Robert; Schurr, Ulrich; Schroeder, Walter Heinz

2010-01-01

Fluxes of mineral nutrients in the xylem are strongly influenced by interactions with the surrounding stem tissues and are probably regulated by them. Toward a mechanistic understanding of these interactions, we applied stable isotope tracers of magnesium, potassium, and calcium continuously to the transpiration stream of cut bean (Phaseolus vulgaris) shoots to study their radial exchange at the cell and tissue level with stem tissues between pith and phloem. For isotope localization, we combined sample preparation with secondary ion mass spectrometry in a completely cryogenic workflow. After 20 min of application, tracers were readily detectable to various degrees in all tissues. The xylem parenchyma near the vessels exchanged freely with the vessels, its nutrient elements reaching a steady state of strong exchange with elements in the vessels within 20 min, mainly via apoplastic pathways. A slow exchange between vessels and cambium and phloem suggested that they are separated from the xylem, parenchyma, and pith, possibly by an apoplastic barrier to diffusion for nutrients (as for carbohydrates). There was little difference in these distributions when tracers were applied directly to intact xylem via a microcapillary, suggesting that xylem tension had little effect on radial exchange of these nutrients and that their movement was mainly diffusive. PMID:19965970

Concentrations of Selected Elements in Liver Tissue of Grey Wolves (Canis lupus) from Serbia.

PubMed

Subotić, Srđan; Višnjić-Jeftić, Željka; Penezić, Aleksandra; Ćirović, Duško

2017-12-01

The grey wolf (Canis lupus) is a large carnivore species and a top predator in the ecosystems that it inhabits. Considering its role in food webs, wolves may be exposed to high concentrations of potentially harmful elements. Therefore liver samples from 28 legally hunted wolves were analyzed for concentrations of 16 elements using inductively coupled plasma optical emission spectrometry. The Mann-Whitney U test showed a significant difference between the genders only for Li, and there were no differences between individuals caught in different years. The majority of statistically significant correlations between element levels were positive, except for three cases. Compliance with several criteria for suitable bioindicator organisms imply that wolves may serve for monitoring environmental contamination.

A 310-bp minimal promoter mediates smooth muscle cell-specific expression of telokin.

PubMed

Smith, A F; Bigsby, R M; Word, R A; Herring, B P

1998-05-01

A cell-specific promoter located in an intron of the smooth muscle myosin light chain kinase gene directs transcription of telokin exclusively in smooth muscle cells. Transgenic mice were generated in which a 310-bp rabbit telokin promoter fragment, extending from -163 to +147, was used to drive expression of simian virus 40 large T antigen. Smooth muscle-specific expression of the T-antigen transgene paralleled that of the endogenous telokin gene in all smooth muscle tissues except uterus. The 310-bp promoter fragment resulted in very low levels of transgene expression in uterus; in contrast, a transgene driven by a 2.4-kb fragment (-2250 to +147) resulted in high levels of transgene expression in uterine smooth muscle. Telokin expression levels correlate with the estrogen status of human myometrial tissues, suggesting that deletion of an estrogen response element (ERE) may account for the low levels of transgene expression driven by the 310-bp rabbit telokin promoter in uterine smooth muscle. Experiments in A10 smooth muscle cells directly showed that reporter gene expression driven by the 2.4-kb, but not 310-bp, promoter fragment could be stimulated two- to threefold by estrogen. This stimulation was mediated through an ERE located between -1447 and -1474. Addition of the ERE to the 310-bp fragment restored estrogen responsiveness in A10 cells. These data demonstrate that in addition to a minimal 310-bp proximal promoter at least one distal cis-acting regulatory element is required for telokin expression in uterine smooth muscle. The distal element may include an ERE between -1447 and -1474.

Application of wavelet based MFDFA on Mueller matrix images for cervical pre-cancer detection

NASA Astrophysics Data System (ADS)

Zaffar, Mohammad; Pradhan, Asima

2018-02-01

A systematic study has been conducted on application of wavelet based multifractal de-trended fluctuation analysis (MFDFA) on Mueller matrix (MM) images of cervical tissue sections for early cancer detection. Changes in multiple scattering and orientation of fibers are observed by utilizing a discrete wavelet transform (Daubechies) which identifies fluctuations over polynomial trends. Fluctuation profiles, after 9th level decomposition, for all elements of MM qualitatively establish a demarcation of different grades of cancer from normal tissue. Moreover, applying MFDFA on MM images, Hurst exponent profiles for images of MM qualitatively are seen to display differences. In addition, the values of Hurst exponent increase for the diagonal elements of MM with increasing grades of the cervical cancer, while the value for the elements which correspond to linear polarizance decrease. However, for circular polarizance the value increases with increasing grades. These fluctuation profiles reveal the trend of local variation of refractive -indices and along with Hurst exponent profile, may serve as a useful biological metric in the early detection of cervical cancer. The quantitative measurements of Hurst exponent for diagonal and first column (polarizance governing elements) elements which reflect changes in multiple scattering and structural anisotropy in stroma, may be sensitive indicators of pre-cancer.

Involvement of SREBPs in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced disruption of lipid metabolism in male guinea pig

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishiumi, Shin; Yabushita, Yoshiyuki; Furuyashiki, Takashi

2008-06-15

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has multiple toxic effects causing a wasting syndrome characterized by a loss of body weight accompanied by a decrease in adipose tissue weight. To elucidate the mechanism behind this syndrome, we investigated the changes in lipid metabolism 7 and 21 days after a single intraperitoneal injection of TCDD at 1 {mu}g/kg body weight to male guinea pigs. TCDD caused the symptoms of the syndrome, body weight loss with a decrease in adipose tissue weight, while it increased the levels of triacylglycerols, total cholesterols, and free fatty acids in plasma. On day 7, TCDD decreased the levels of CCAAT/enhancermore » binding protein (C/EBP) {alpha}, peroxisome proliferator activated receptor {gamma}, and glucose transporter 4, adipogenesis-related factors, in adipose tissue, whereas the levels of retinoid X receptor {alpha}, C/EBP{beta}, C/EBP{delta}, and c-Myc remained unchanged. TCDD also reduced the levels of both p125 precursor and p68 active forms of sterol regulatory element binding protein (SREBP)-1 and -2, the lypogenesis-related factors, and downregulated their DNA binding activity in adipose tissue, while it raised the levels of their p68 active forms and increased their DNA binding activity in the liver. TCDD decreased mRNA and protein levels of acetyl-CoA carboxylase and HMG-CoA synthase in the liver and adipose tissue. Similar results were obtained on day 21. These results suggest that TCDD disrupts lipid metabolism through changes in the expression levels of the adipogenesis-related and lipogenesis-related proteins in the liver and adipose tissue, and SREBPs would be involved in the development of the wasting syndrome.« less

Phytotoxicity of tin mine waste and accumulation of involved heavy metals in common buckwheat (Fagopyrum esculentum Moench).

PubMed

Franzaring, Jürgen; Damsohn, Walter; Fangmeier, Andreas; Schlosser, Sonja; Kurz, Hannes; Büttner, Philipp

2018-04-16

Extraction and processing of cassiterite (SnO 2 ) left large tailings with high concentrations of tin, tungsten, molybdenum and lithium. Information on the phytotoxicity of mine waste is important with regard to ecological hazards. Exposure studies help to identify plants useful for the stabilization of waste tips and the phytomining of metals. A greenhouse study was performed using a dilution series of mine waste and four crops, a halophytic and a metallophytic species to derive dose response curves. Based on effective doses for growth reductions, sensitivity increased in the following order: maize > common buckwheat > quinoa > garden bean. Element analyses in different species and compartments of common buckwheat grown in a mixture of standard soil and 25% of the mine waste showed that only low levels of the metals were taken up and that transfer to seed tissues was negligible. As indicated by soil metal levels prior to and after the experiment, only lithium and arsenic proved to be plant available and reached high levels in green tissues while seed levels were low. The experiment confirmed differences in the uptake of metals with regard to elements and species. Common buckwheat is a suited candidate for cultivation on metal polluted soils.

Growth of plant tissue cultures in simulated lunar soil: Implications for a lunar base CELSS (Controlled Ecological Life Support System)

NASA Technical Reports Server (NTRS)

Venketeswaran, S.

1988-01-01

Experiments were carried out on plant tissue cultures, seed germination, seedling development and plants grown on Simulated Lunar Soil to evaluate the potential of future development of lunar based agriculture. The studies done to determine the effect of the placement of SLS on tissue cultures showed no adverse effect of SLS on tissue cultures. Although statistically insignificant, SLS in suspension showed a comparatively higher growth rate. Observations indicate the SLS, itself cannot support calli growth but was able to show a positive effect on growth rate of calli when supplemented with MS salts. This positive effect related to nutritive value of the SLS was found to have improved at high pH levels, than at the recommended low pH levels for standard media. Results from seed germination indicated that there is neither inhibitory, toxicity nor stimulatory effect of SLS, even though SLS contains high amounts of aluminum compounds compared to earth soil. Analysis of seeding development and growth data showed significant reduction in growth rate indicating that, SLS was a poor growth medium for plant life. This was confirmed by the studies done with embryos and direct plant growth on SLS. Further observations attributed this poor quality of SLS is due to it's lack of essential mineral elements needed for plant growth. By changing the pH of the soil, to more basic conditions, the quality of SLS for plant growth could be improved up to a significant level. Also it was found that the quality of SLS could be improved by almost twice, by external supply of major mineral elements, directly to SLS.

Polonium-210 and selenium in tissues and tissue extracts of the mussel Mytilus galloprovincialis (Gulf of Trieste).

PubMed

Kristan, Urška; Planinšek, Petra; Benedik, Ljudmila; Falnoga, Ingrid; Stibilj, Vekoslava

2015-01-01

Marine organisms such as mussels and fish take up polonium (Po) and selenium (Se), and distribute them into different cellular components and compartments. Due to its high radiotoxicity and possible biomagnification across the marine food chain Po-210 is potentially hazardous, while selenium is an essential trace element for humans and animals. The aim of this study was to investigate and compare the presence and extractability of the elements in the mussels Mytilus galloprovincialis collected in the Gulf of Trieste. The levels of Po-210 in the samples ranged from 220 to 400 Bq kg(-1) and of Se from 2.6 to 8.2 mg kg(-1), both on a dry matter basis. Using various extraction types and conditions in water, buffer or enzymatic media, the best extractability was obtained with enzymatic extraction (Protease XIV, 1h shaking at 40 °C) and the worst by water extraction (24 h shaking at 37 °C). 90% of Po-210 and 70% of Se was extractable in the first case versus less than 10% of Po-210 and less than 40% of Se in the second. Such evident differences in extractability between the investigated elements point to different metabolic pathways of the two elements. In enzymatic extracts Se speciation revealed three Se compounds (SeCys2, SeMet, one undefined), while Po-210 levels were too low to allow any conclusions about speciation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Maternal transfer of trace elements in the Atlantic horseshoe crab (Limulus polyphemus).

PubMed

Bakker, Aaron K; Dutton, Jessica; Sclafani, Matthew; Santangelo, Nicholas

2017-01-01

The maternal transfer of trace elements is a process by which offspring may accumulate trace elements from their maternal parent. Although maternal transfer has been assessed in many vertebrates, there is little understanding of this process in invertebrate species. This study investigated the maternal transfer of 13 trace elements (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn) in Atlantic horseshoe crab (Limulus polyphemus) eggs and compared concentrations to those in adult leg and gill tissue. For the majority of individuals, all trace elements were transferred, with the exception of Cr, from the female to the eggs. The greatest concentrations on average transferred to egg tissue were Zn (140 µg/g), Cu (47.8 µg/g), and Fe (38.6 µg/g) for essential elements and As (10.9 µg/g) and Ag (1.23 µg/g) for nonessential elements. For elements that were maternally transferred, correlation analyses were run to assess if the concentration in the eggs were similar to that of adult tissue that is completely internalized (leg) or a boundary to the external environment (gill). Positive correlations between egg and leg tissue were found for As, Hg, Se, Mn, Pb, and Ni. Mercury, Mn, Ni, and Se were the only elements correlated between egg and gill tissue. Although, many trace elements were in low concentration in the eggs, we speculate that the higher transfer of essential elements is related to their potential benefit during early development versus nonessential trace elements, which are known to be toxic. We conclude that maternal transfer as a source of trace elements to horseshoe crabs should not be overlooked and warrants further investigation.

The duration of pregnancy in ecologically-challenged area. The effects of environmental pollution with aromatic hydrocarbons on the angiogenesis and elements of the mesenchymal tissue of the human placenta.

PubMed

Wierzba, Waldemar; Radowicki, Stanisław; Bojar, Iwona; Pinkas, Jarosław

2017-01-01

The literature presents only few reports regarding the effects of elevated levels of aromatic hydrocarbons (AH) on the functions of the human placenta. The effects of environmental contamination with AH (including phenol and 1-hydroxypyrene) have certain negative effects on parenchymal organs such as human placenta. The paper aimed to assess the effects of elevated levels of AH on the placental angiogenesis and elements of the mesenchymal tissue of the placenta. Tissue material from 50 afterbirths from Płock constituted a study group, whereas 50 afterbirths from Kutno constituted a control group. Immunohistochemical reactions with the peroxidase method using LSAB kits (DAKO) were performed. The extent and intensity of reactions were analysed. The levels of phenols and 1-hydroxypyrene in the excreted urine of pregnant women (undergoing delivery) were detected using gas chromatography and colorimetry. The levels of phenol and 1-hydroxypyrene in the excreted urine were demonstrated to be statistically significantly higher in patients living in the area of Płock. Statistically significantly higher expression of antibodies indicating placental angiogenesis was observed in the placentas in the Płock group (p < 0.01). Moreover, lower expression of vimentin indicating reactions with proteins in mesenchymal cells was observed in the Kutno group (p < 0.01). Pregnancy in the environment with elevated levels of aromatic hydrocarbons has detrimental effects on the human placenta. The foetus is protected by activation of adaptation and compensation mechanisms that are manifested as significant angiogenesis and greater development and differentiation of mesenchymal cells compared to the control group.

Free-ranging domestic cats are characterized by increased metal content in reproductive tissues.

PubMed

Rzymski, Piotr; Niedzielski, Przemysław; Poniedziałek, Barbara; Rzymski, Paweł; Pacyńska, Joanna; Kozak, Lidia; Dąbrowski, Piotr

2015-12-01

Trace metals may be supportive to mammalian reproduction but also reveal certain toxicities. The present study investigated the content of selected metals (Ca, Cd, Cu, Mn, Mg, Ni, Pb, Zn) in uterine and testicular tissue of free-ranging and household cats and its relation with hair metal status, cats' age, weight, physical activity, diet and inhabited environment. Free-rangers and cats not fed by humans were characterized by higher concentrations of essential metals in their reproductive tissues as well as increased levels of toxic elements, particularly Cd and Ni. No difference in metal status was found for household individuals fed on different varieties of commercial food. Cats inhabiting urbanized areas were characterized by higher Pb levels in their reproductive system. Feline hair was found to be less, if at all, susceptible to environmental, lifestyle and dietary variables and most importantly, did not reflect a metal burden in reproductive tissues. Copyright © 2015 Elsevier Inc. All rights reserved.

Correlation of trace element concentrations between epidermis and internal organ tissues in Indo-Pacific humpback dolphins (Sousa chinensis).

PubMed

Sun, Xian; Yu, Ri-Qing; Zhang, Mei; Zhang, Xiyang; Chen, Xi; Xiao, Yousheng; Ding, Yulong; Wu, Yuping

2017-12-15

Trace element accumulation in the epidermis of cetaceans has been less studied. This study explored the feasibility of using epidermis as a surrogate tissue to evaluate internal contaminant burdens in Indo-Pacific humpback dolphin (Sousa chinensis). Eleven trace elements were analyzed in the epidermis, muscle and liver tissues from 46 individuals of dolphins stranded along the Pearl River Estuary (PRE) coast between 2007 and 2013. Trace elemental concentrations varied among the three tissues, generally with the highest concentrations found in liver tissues and lowest in the epidermis (except Zn, As, and Pb). Zn concentration in the epidermis was the highest among all tissues, indicating that Zn could be an important element for the epidermis physiology. High concentrations of Hg and Cr in liver were likely due to an excessive intake by dolphins which consumed high Hg and Cr contaminated fishes in the PRE. Hg concentrations in epidermis and muscle tissues were significantly higher in the females than in males. Concentrations of V and Pb in liver, Se and Cd in both muscle and liver, and As and Hg in all tissue samples showed significantly positive relationships with body length. Hepatic Cu concentrations were significantly negatively correlated with the body length. Hg and As concentrations in epidermis showed significantly positive correlations with those in liver tissues. Thus this study proposed that epidermis could be used as a non-invasive monitoring tissue to evaluate Hg and As bioaccumulation in internal tissues of Indo-Pacific humpback dolphins populations. Copyright © 2017 Elsevier B.V. All rights reserved.

A novel method to detect unlabeled inorganic nanoparticles and submicron particles in tissue by sedimentation field-flow fractionation

PubMed Central

Deering, Cassandra E; Tadjiki, Soheyl; Assemi, Shoeleh; Miller, Jan D; Yost, Garold S; Veranth, John M

2008-01-01

A novel methodology to detect unlabeled inorganic nanoparticles was experimentally demonstrated using a mixture of nano-sized (70 nm) and submicron (250 nm) silicon dioxide particles added to mammalian tissue. The size and concentration of environmentally relevant inorganic particles in a tissue sample can be determined by a procedure consisting of matrix digestion, particle recovery by centrifugation, size separation by sedimentation field-flow fractionation (SdFFF), and detection by light scattering. Background Laboratory nanoparticles that have been labeled by fluorescence, radioactivity, or rare elements have provided important information regarding nanoparticle uptake and translocation, but most nanomaterials that are commercially produced for industrial and consumer applications do not contain a specific label. Methods Both nitric acid digestion and enzyme digestion were tested with liver and lung tissue as well as with cultured cells. Tissue processing with a mixture of protease enzymes is preferred because it is applicable to a wide range of particle compositions. Samples were visualized via fluorescence microscopy and transmission electron microscopy to validate the SdFFF results. We describe in detail the tissue preparation procedures and discuss method sensitivity compared to reported levels of nanoparticles in vivo. Conclusion Tissue digestion and SdFFF complement existing techniques by precisely identifying unlabeled metal oxide nanoparticles and unambiguously distinguishing nanoparticles (diameter<100 nm) from both soluble compounds and from larger particles of the same nominal elemental composition. This is an exciting capability that can facilitate epidemiological and toxicological research on natural and manufactured nanomaterials. PMID:19055780

Growth and patterning in the conodont skeleton

PubMed Central

Donoghue, P. C. J.

1998-01-01

Recent advances in our understanding of conodont palaeobiology and functional morphology have rendered established hypotheses of element growth untenable. In order to address this problem, hard tissue histology is reviewed paying particular attention to the relationships during growth of the component hard tissues comprising conodont elements, and ignoring a priori assumptions of the homologies of these tissues. Conodont element growth is considered further in terms of the pattern of formation, of which four distinct types are described, all possibly derived from a primitive condition after heterochronic changes in the timing of various developmental stages. It is hoped that this may provide further means of unravelling conodont phylogeny. The manner in which the tissues grew is considered homologous with other vertebrate hard tissues, and the elements appear to have grown in a way similar to the growing scales and growing dentition of other vertebrates.

Recent developments in human biomonitoring: non-invasive assessment of target tissue dose and effects of pneumotoxic metals.

PubMed

Mutti, A; Corradi, M

2006-01-01

Tobacco smoke and polluted environments substantially increase the lung burden of pneumotoxic chemicals, particularly pneumotoxic metallic elements. To achieve a better understanding of the early events between exposure to inhaled toxicants and the onset of adverse effects on the lung, the characterization of dose at the target organ would be extremely useful. Exhaled breath condensate (EBC), obtained by cooling exhaled air under conditions of spontaneous breathing, is a novel technique that could provide a non-invasive assessment of pulmonary pathobiology. Considering that EBC is water practically free of interfering solutes, it represents an ideal biological matrix for elemental characterization. Published data show that several toxic metals and trace elements are detectable in EBC, raising the possibility of using this medium to quantify the lung tissue dose of pneumotoxic substances. This novel approach may represent a significant advance over the analysis of alternative media (blood, serum, urine, hair), which are not as reliable (owing to interfering substances in the complex matrix) and reflect systemic rather than lung (target tissue) levels of both toxic metals and essential trace elements. Data obtained among workers occupationally exposed to either hard metals or chromium (VI) and in smokers with or without chronic obstructive pulmonary disease (COPD) are reviewed to show that--together with biomarkers of exposure--EBC also allows the simultaneous quantification of biomarkers of effect directly sampled from the epithelial lining fluid, thus providing novel insights on both kinetic and dynamic aspects of metal toxicology.

Tissue oxygen demand in regulation of the behavior of the cells in the vasculature.

PubMed

Barvitenko, Nadezhda N; Aslam, Muhammad; Filosa, Jessica; Matteucci, Elena; Nikinmaa, Mikko; Pantaleo, Antonella; Saldanha, Carlota; Baskurt, Oguz K

2013-08-01

The control of arteriolar diameters in microvasculature has been in the focus of studies on mechanisms matching oxygen demand and supply at the tissue level. Functionally, important vascular elements include EC, VSMC, and RBC. Integration of these different cell types into functional units aimed at matching tissue oxygen supply with tissue oxygen demand is only achieved when all these cells can respond to the signals of tissue oxygen demand. Many vasoactive agents that serve as signals of tissue oxygen demand have their receptors on all these types of cells (VSMC, EC, and RBC) implying that there can be a coordinated regulation of their behavior by the tissue oxygen demand. Such functions of RBC as oxygen carrying by Hb, rheology, and release of vasoactive agents are considered. Several common extra- and intracellular signaling pathways that link tissue oxygen demand with control of VSMC contractility, EC permeability, and RBC functioning are discussed. © 2013 John Wiley & Sons Ltd.

[Effect of cigarette smoking on coexistence of cadmium and zinc in retained wisdom teeth].

PubMed

Malara, Piotr; Kwapuliński, Jerzy; Drugacz, Jan; Malara, Beata

2005-01-01

The change in coexistence pattern of elements (antagonism-synergism) in conditions of excessive level of toxic element is observed in many biological samples. The aim of this study was to establish the cadmium and zinc content in hard tissues of retained wisdom teeth of smokers and non-smokers and to find out if active exposure to cigarette smoke has an influence on coexistence of both metals in these tissues. Material consisted of 127 retained wisdom teeth (65 from smokers and 62 from non-smokers). Cadmium and zinc contents were determined by means of atomic absorption spectrometry. We found out that retained wisdom tooth from smokers exhibited higher cadmium and zinc contents compared to non-smokers' teeth. Moreover, coexistence pattern of cadmium and zinc in teeth depends on exposure to heavy metals and exhibits strong synergism in smokers.

Effects of valerian consumption during pregnancy on cortical volume and the levels of zinc and copper in the brain tissue of mouse fetus.

PubMed

Mahmoudian, Alireza; Rajaei, Ziba; Haghir, Hossein; Banihashemian, Shahaboldin; Hami, Javad

2012-04-01

The aim of the present study was to determine the effects of valerian (Valeriana officinalis) consumption in pregnancy on cortical volume and the levels of zinc and copper, two essential elements that affect brain development and function, in the brain tissues of mouse fetuses. Pregnant female mice were treated with either saline or 1.2 g/kg body weight valerian extract intraperitoneally daily on gestation days (GD) 7 to 17. On GD 20, mice were sacrificed and their fetuses were collected. Fetal brains were dissected, weighed and processed for histological analysis. The volume of cerebral cortex was estimated by the Cavalieri principle. The levels of zinc and copper in the brain tissues were measured by atomic absorption spectroscopy. The results indicated that valerian consumption in pregnancy had no significant effect on brain weight, cerebral cortex volume and copper level in fetal brain. However,it significantly decreased the level of zinc in the brain (P<0.05). Using valerian during midgestation do not have an adverse effect on cerebral cortex; however,it caused a significant decrease in zinc level in the fetal brain. This suggests that valerian use should be limited during pregnancy.

Tissue engineering: construction of a multicellular 3D scaffold for the delivery of layered cell sheets.

PubMed

Turner, William S; Sandhu, Nabjot; McCloskey, Kara E

2014-10-03

Many tissues, such as the adult human hearts, are unable to adequately regenerate after damage.(2,3) Strategies in tissue engineering propose innovations to assist the body in recovery and repair. For example, TE approaches may be able to attenuate heart remodeling after myocardial infarction (MI) and possibly increase total heart function to a near normal pre-MI level.(4) As with any functional tissue, successful regeneration of cardiac tissue involves the proper delivery of multiple cell types with environmental cues favoring integration and survival of the implanted cell/tissue graft. Engineered tissues should address multiple parameters including: soluble signals, cell-to-cell interactions, and matrix materials evaluated as delivery vehicles, their effects on cell survival, material strength, and facilitation of cell-to-tissue organization. Studies employing the direct injection of graft cells only ignore these essential elements.(2,5,6) A tissue design combining these ingredients has yet to be developed. Here, we present an example of integrated designs using layering of patterned cell sheets with two distinct types of biological-derived materials containing the target organ cell type and endothelial cells for enhancing new vessels formation in the "tissue". Although these studies focus on the generation of heart-like tissue, this tissue design can be applied to many organs other than heart with minimal design and material changes, and is meant to be an off-the-shelf product for regenerative therapies. The protocol contains five detailed steps. A temperature sensitive Poly(N-isopropylacrylamide) (pNIPAAM) is used to coat tissue culture dishes. Then, tissue specific cells are cultured on the surface of the coated plates/micropattern surfaces to form cell sheets with strong lateral adhesions. Thirdly, a base matrix is created for the tissue by combining porous matrix with neovascular permissive hydrogels and endothelial cells. Finally, the cell sheets are lifted from the pNIPAAM coated dishes and transferred to the base element, making the complete construct.

Low magnesium diet alters distribution of macroelements and trace elements in tissues and organs of female rats.

PubMed

Zheltova, Anastasia A; Kharitonova, Maria V; Iezhitsa, Igor N; Serebryansky, Eugeny P; Evsyukov, Oleg Y; Spasov, Alexander A; Skalny, Anatoly V

2017-01-01

The aim of the present study was to assess whether dietary magnesium deficiency can alter distribution of macroelements and trace elements in different organs and tissues. Experiments were carried out on 12 adult female Wistar rats, which were fed either a diet with low Mg content (≤20mgkg -1 of diet) (LMgD) or a diet with daily recommended Mg content (≈500mgkg -1 ) as control group (CG) for 70 days. On the 70th day of the experiment heart, aorta, femoral skeletal muscle, forebrain, cerebellum, pituitary gland, thyroid gland, ovaries, uterus, liver, kidneys, and spleen were taken for analysis of mineral content. Concentrations of Fe and Ca were measured by inductively coupled plasma-atomic emission spectrometry, and levels of Na, K, Mg, Co, Cu, Zn, Ni, Se, I were determined by inductively coupled plasma mass spectrometry. On the 70th day, LMgD led to significant reduction of Mg level in red blood cells, plasma, aorta, uterus and thyroid gland compared to CG as well as resulted in significant decrease of Mg/Ca ratio in kidneys, spleen and ovaries. Contrary to this, an increase of Mg/Ca ratio was found in cerebellum of LMgD group. Significant decrease of K concentration was shown in aorta of LMgD animals compared to CG whereas myocardial K concentration was increased in LMgD group. Na level was two-fold higher in skeletal muscles of rats that received LMgD in comparison to CG (p=0.006). Increased concentrations of Fe in ovaries and uterus were found in LMgD. Mg restriction did not affect Zn concentration in any of tasted tissues. Se level was higher in spleen and lower in uterus of LMgD animals compared to CG. MgD was accompanied by increased level of Co in skeletal muscles and decreased its level in kidneys and uterus. LMgD feeding was associated with decreased concentrations of Ni in heart, thyroid gland, spleen, uterus and Co in heart, aorta, liver, kidneys, spleen and ovaries. The changes of Mg, K, Co content were accompanied by dramatic (10-fold) decrease of I concentration in aorta of LMgD animals. LMgD causes decrease of I content in ovaries and increase of I level in uterus vs CG. Thus, distribution of macroelements (Ca, Na, K) was weakly affected by Mg restriction that led to the most evident alterations of Co and Ni tissue levels. Moreover, mineral balance of uterus seems to be the most susceptible to low Mg intake. Hypomagnesaemia resulted in significant changes of 5 studied trace elements (Fe, Se, Cu, Ni and Co). Copyright © 2016 Elsevier GmbH. All rights reserved.

Unified viscoelasticity: Applying discrete element models to soft tissues with two characteristic times.

PubMed

Anssari-Benam, Afshin; Bucchi, Andrea; Bader, Dan L

2015-09-18

Discrete element models have often been the primary tool in investigating and characterising the viscoelastic behaviour of soft tissues. However, studies have employed varied configurations of these models, based on the choice of the number of elements and the utilised formation, for different subject tissues. This approach has yielded a diverse array of viscoelastic models in the literature, each seemingly resulting in different descriptions of viscoelastic constitutive behaviour and/or stress-relaxation and creep functions. Moreover, most studies do not apply a single discrete element model to characterise both stress-relaxation and creep behaviours of tissues. The underlying assumption for this disparity is the implicit perception that the viscoelasticity of soft tissues cannot be described by a universal behaviour or law, resulting in the lack of a unified approach in the literature based on discrete element representations. This paper derives the constitutive equation for different viscoelastic models applicable to soft tissues with two characteristic times. It demonstrates that all possible configurations exhibit a unified and universal behaviour, captured by a single constitutive relationship between stress, strain and time as: σ+Aσ̇+Bσ¨=Pε̇+Qε¨. The ensuing stress-relaxation G(t) and creep J(t) functions are also unified and universal, derived as [Formula: see text] and J(t)=c2+(ε0-c2)e(-PQt)+σ0Pt, respectively. Application of these relationships to experimental data is illustrated for various tissues including the aortic valve, ligament and cerebral artery. The unified model presented in this paper may be applied to all tissues with two characteristic times, obviating the need for employing varied configurations of discrete element models in preliminary investigation of the viscoelastic behaviour of soft tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigation of the differentiation of ex vivo nerve and fat tissues using laser-induced breakdown spectroscopy (LIBS): Prospects for tissue-specific laser surgery.

PubMed

Mehari, Fanuel; Rohde, Maximillian; Kanawade, Rajesh; Knipfer, Christian; Adler, Werner; Klämpfl, Florian; Stelzle, Florian; Schmidt, Michael

2016-10-01

In the present study, the elemental compositions of fat and nerve tissue during their plasma mediated laser ablation are studied in the context of tissue differentiation for laser surgery applications by using Laser-Induced Breakdown Spectroscopy (LIBS). Tissue samples of porcine fat and nerve were prepared as ex vivo experimental objects. Plasma mediated laser ablation is performed using an Nd : YAG laser in open air and under normal stray light conditions. The performed measurements suggest that the two tissue types show a high similarity in terms of qualitative elemental composition while at the same time revealing a distinct difference in the concentration of the constituent elements. Different analysis approaches are evaluated and discussed to optimize the tissue-differentiation performance of the LIBS approach. Plasma mediated laser tissue ablation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Accumulation of heavy metals and As in liver, hair, femur, and lung of Persian jird (Meriones persicus) in Darreh Zereshk copper mine, Iran.

PubMed

Khazaee, Manoochehr; Hamidian, Amir Hossein; Alizadeh Shabani, Afshin; Ashrafi, Sohrab; Mirjalili, Seyyed Ali Ashghar; Esmaeilzadeh, Esmat

2016-02-01

Rodents frequently serve as bioindicator to monitor the quality of the environment. Concentrations of 11 elements (Cd, Co, Ti, Fe, Mn, Cu, Sb, As, Sr, Ni, and Cr) were investigated and compared in liver, hair, femur, and lung of the Persian jird (Meriones persicus) from Darreh Zereshk copper mine, Iran. Metals were determined in different tissues of 39 individuals of Persian jird, collected by snap trap in 2014 from five areas of Darreh Zereshk copper mine. Samples were prepared by wet digestion method, and the contents of elements were analyzed with ICP-OES (VARIAN, 725-ES) instrument. Cadmium, Sb, and Co were below the limit of detection, and Mn and As were found only in hair and liver tissues. We detected the highest concentration of Cu, As, Ti, Fe, Mn, Cr, and Ni in hair in comparison with other tissues. Significant higher levels of Ti in femur and hair; Fe in liver and hair; Mn in liver; As in hair; Sr in lung; Cr in lung, hair, femur, and liver; Cu in femur; and Ni in liver and lung tissues were observed in females. Nearly all element concentrations in the tissues of Persian jird from flotation site, Darreh Zereshk and Hasan Abad villages and leaching site (mining areas) were higher than those from tailing dump site (reference site). We found the highest concentrations of As in liver and hair; Ni and Cr in liver, hair, and lung; and Sr in lung and hair tissues of Persian jird in leaching site. We tried to specify the status of elements before fully exploitation of Darreh Zereshk copper mine by using bioindicator species. Based on our achievements, initial activities did not strongly pollute the surrounded environment of the mine. The high abundance of Persian jird as well as their several proper features makes them a suitable species for biomonitoring programs especially for further studies will be performed after full exploitation of Darreh Zereshk copper mine.

A comparison of sample preparation strategies for biological tissues and subsequent trace element analysis using LA-ICP-MS.

PubMed

Bonta, Maximilian; Török, Szilvia; Hegedus, Balazs; Döme, Balazs; Limbeck, Andreas

2017-03-01

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is one of the most commonly applied methods for lateral trace element distribution analysis in medical studies. Many improvements of the technique regarding quantification and achievable lateral resolution have been achieved in the last years. Nevertheless, sample preparation is also of major importance and the optimal sample preparation strategy still has not been defined. While conventional histology knows a number of sample pre-treatment strategies, little is known about the effect of these approaches on the lateral distributions of elements and/or their quantities in tissues. The technique of formalin fixation and paraffin embedding (FFPE) has emerged as the gold standard in tissue preparation. However, the potential use for elemental distribution studies is questionable due to a large number of sample preparation steps. In this work, LA-ICP-MS was used to examine the applicability of the FFPE sample preparation approach for elemental distribution studies. Qualitative elemental distributions as well as quantitative concentrations in cryo-cut tissues as well as FFPE samples were compared. Results showed that some metals (especially Na and K) are severely affected by the FFPE process, whereas others (e.g., Mn, Ni) are less influenced. Based on these results, a general recommendation can be given: FFPE samples are completely unsuitable for the analysis of alkaline metals. When analyzing transition metals, FFPE samples can give comparable results to snap-frozen tissues. Graphical abstract Sample preparation strategies for biological tissues are compared with regard to the elemental distributions and average trace element concentrations.

The relationships between mercury and selenium in plankton and fish from a tropical food web.

PubMed

do A Kehrig, Helena; Seixas, Tércia G; Palermo, Elisabete A; Baêta, Aida P; Castelo-Branco, Christina W; Malm, Olaf; Moreira, Isabel

2009-01-01

Selenium (Se) has been shown to reduce mercury (Hg) bioavailability and trophic transfer in aquatic ecosystems. The study of methylmercury (MeHg) and Se bioaccumulation by plankton is therefore of great significance in order to obtain a better understanding of the estuarine processes concerning Hg and Se accumulation and biomagnification throughout the food web. In the western South Atlantic, few studies have documented trace element and MeHg in fish tissues. No previous study about trace elements and MeHg in plankton has been conducted concerning tropical marine food webs. Se, Hg, and MeHg were determined in two size classes of plankton, microplankton (70-290 microm) and mesoplankton (>or=290 microm), and also in muscle tissues and livers of four fish species of different trophic levels (Mugil liza, a planktivorous fish; Bagre spp., an omnivorous fish; Micropogonias furnieri, a benthic carnivorous fish; and Centropomus undecimalis, a pelagic carnivorous fish) from a polluted estuary in the Brazilian Southeast coast, Guanabara Bay. Biological and ecological factors such as body length, feeding habits, and trophic transfer were considered in order to outline the relationships between these two elements. The differences in trace element levels among the different trophic levels were investigated. Fish were collected from July 2004 to August 2005 at Guanabara Bay. Plankton was collected from six locations within the bay in August 2005. Total mercury (THg) was determined by cold vapor atomic absorption spectrometry (CV-AAS) with sodium borohydride as a reducing agent. MeHg analysis was conducted by digesting samples with an alcoholic potassium hydroxide solution followed by dithizone-toluene extraction. MeHg was then identified and quantified in the toluene layer by gas chromatography with an electron capture detector (GC-ECD). Se was determined by AAS using graphite tube with Pin platform and Zeeman background correction. Total mercury, MeHg, and Se increased with plankton size class. THg and Se values were below 2.0 and 4.8 microg g(-1) dry wt in microplankton and mesoplankton, respectively. A large excess of molar concentrations of Se in relation to THg was observed in both plankton size class and both fish tissues. Plankton presented the lowest concentrations of this element. In fish, the liver showed the highest THg and Se concentrations. THg and Se in muscle were higher in Centropomus undecimalis (3.4 and 25.5 nmol g(-1)) than in Micropogonias furnieri (2.9 and 15.3 nmol g(-1)), Bagre spp (1.3 and 3.4 nmol g(-1)) and Mugil liza (0.3 and 5.1 nmol g(-1)), respectively. The trophic transfer of THg and Se was observed between trophic levels from prey (considering microplankton and mesoplankton) to top predator (fish). The top predators in this ecosystem, Centropomus undecimalis and Micropogonias furnieri, presented similar MeHg concentrations in muscles and liver. Microplankton presented lower ratios of methylmercury to total mercury concentration (MeHg/THg) (34%) than those found in mesoplankton (69%) and in the muscle of planktivorous fish, Mugil liza (56%). The other fish species presented similar MeHg/THg in muscle tissue (of around 100%). M. liza showed lower MeHg/THg in the liver than C. undecimalis (35%), M. furnieri (31%) and Bagre spp. (22%). Significant positive linear relationships were observed between the molar concentrations of THg and Se in the muscle tissue of M. furnieri and M. liza. These fish species also showed significant inverse linear relationships between hepatic MeHg and Se, suggesting a strong antagonistic effect of Se on MeHg assimilation and accumulation. Differences found among the concentrations THg, MeHg, and Se in microplankton, mesozooplankton, and fishes were probably related to the preferred prey and bioavailability of these elements in the marine environment. The increasing concentration of MeHg and Se at successively higher trophic levels of the food web of Guanabara Bay corresponds to a transfer between trophic levels from the lower trophic level to the top-level predator, suggesting that MeHg and Se were biomagnified throughout the food web. Hg and Se were positively correlated with the fish standard length, suggesting that larger and older fish bioaccumulated more of these trace elements. THg, MeHg, and Se were a function of the plankton size. There is a need to assess the role of selenium in mercury accumulation in tropical ecosystems. Without further studies of the speciation of selenium in livers of fishes from this region, the precise role of this element, if any, cannot be verified in positively affecting mercury accumulation. Further studies of this element in the study of marine species should include liver samples containing relatively high concentrations of mercury. A basin-wide survey of selenium in fishes is also recommended.

Analysis of human tissues by total reflection X-ray fluorescence. Application of chemometrics for diagnostic cancer recognition

NASA Astrophysics Data System (ADS)

Benninghoff, L.; von Czarnowski, D.; Denkhaus, E.; Lemke, K.

1997-07-01

For the determination of trace element distributions of more than 20 elements in malignant and normal tissues of the human colon, tissue samples (approx. 400 mg wet weight) were digested with 3 ml of nitric acid (sub-boiled quality) by use of an autoclave system. The accuracy of measurements has been investigated by using certified materials. The analytical results were evaluated by using a spreadsheet program to give an overview of the element distribution in cancerous samples and in normal colon tissues. A further application, cluster analysis of the analytical results, was introduced to demonstrate the possibility of classification for cancer diagnosis. To confirm the results of cluster analysis, multivariate three-way principal component analysis was performed. Additionally, microtome frozen sections (10 μm) were prepared from the same tissue samples to compare the analytical results, i.e. the mass fractions of elements, according to the preparation method and to exclude systematic errors depending on the inhomogeneity of the tissues.

Towards an orientation-distribution-based multi-scale approach for remodelling biological tissues.

PubMed

Menzel, A; Harrysson, M; Ristinmaa, M

2008-10-01

The mechanical behaviour of soft biological tissues is governed by phenomena occurring on different scales of observation. From the computational modelling point of view, a vital aspect consists of the appropriate incorporation of micromechanical effects into macroscopic constitutive equations. In this work, particular emphasis is placed on the simulation of soft fibrous tissues with the orientation of the underlying fibres being determined by distribution functions. A straightforward but convenient Taylor-type homogenisation approach links the micro- or rather meso-level of fibres to the overall macro-level and allows to reflect macroscopically orthotropic response. As a key aspect of this work, evolution equations for the fibre orientations are accounted for so that physiological effects like turnover or rather remodelling are captured. Concerning numerical applications, the derived set of equations can be embedded into a nonlinear finite element context so that first elementary simulations are finally addressed.

Three levels of neuroelectronic interfacing: silicon chips with ion channels, nerve cells, and brain tissue.

PubMed

Fromherz, Peter

2006-12-01

We consider the direct electrical interfacing of semiconductor chips with individual nerve cells and brain tissue. At first, the structure of the cell-chip contact is studied. Then we characterize the electrical coupling of ion channels--the electrical elements of nerve cells--with transistors and capacitors in silicon chips. On that basis it is possible to implement signal transmission between microelectronics and the microionics of nerve cells in both directions. Simple hybrid neuroelectronic systems are assembled with neuron pairs and with small neuronal networks. Finally, the interfacing with capacitors and transistors is extended to brain tissue cultured on silicon chips. The application of highly integrated silicon chips allows an imaging of neuronal activity with high spatiotemporal resolution. The goal of the work is an integration of neuronal network dynamics with digital electronics on a microscopic level with respect to experiments in brain research, medical prosthetics, and information technology.

[The elemental composition of teeth hard tissues depending on the state of the environment].

PubMed

Suladze, N; Shishniashvili, T; Margvelashvili, V; Kobakhidze, K

2014-01-01

At present, great attention is paid to the origin of man-made micro elemental anomalies. To monitor the state of the environment and its effects on the human body, of great importance is the determination of the amount and distribution of various chemical elements in the dentin and enamel of the teeth. To determine the essential (Ca, Zn, Mn, Ni), conditionally essential (Rb, Ni, Sr) and toxic (Pb, Hg) trace elements in the mineralized tissues of the teeth and to identify the relationship between the elemental composition of the tooth structure and the state of the general and dental health depending on the state of the environment, we have examined 29 children aged 3-4 years who have carried out analysis of hard tissue of teeth (teeth used for remote medical reasons) for the maintenance of nine chemical elements. Children living in a relatively environmentally favorable conditions essential value and conditionally essential elements in the mineralized tissues of the teeth were within normal limits, and toxic elements slightly increased limits that differ from those of children living in environmentally disadvantaged areas. In particular, these essential elements were significantly reduced (except for zinc), as indicators of toxic elements - mercury and lead, increased by 12.5% and 44.5%, respectively, which is clearly reflected on the state of dental health because noted decompensated form of tooth decay. Thus, deviations in a state of general and dental health of children associated with an imbalance of macro-and microelements in the mineralized tissues of the teeth.

Concentrations of trace elements in tissues of red fox (Vulpes vulpes) and stone marten (Martes foina) from suburban and rural areas in Croatia.

PubMed

Bilandžić, Nina; Dežđek, Danko; Sedak, Marija; Dokić, Maja; Solomun, Božica; Varenina, Ivana; Knežević, Zorka; Slavica, Alen

2010-11-01

Trace elements concentrations (As, Cd, Cu, Pb and Hg) were determined in the liver, kidney and muscle of 28 red fox (Vulpes vulpes) and 16 stone marten (Martes foina) from suburban and rural habitats from Croatia. Rural and suburban habitats affected Cd and Hg levels in the muscle, liver and kidney of red fox. Significant differences in metal concentrations in the muscle, liver and kidney were detected among species. Suburban stone marten accumulated the highest levels of trace elements (mg/kg w.w.): in muscle 0.019 for Hg; in liver 0.161 for Cd, 36.1 for Cu and 0.349 for Pb; in kidney 1.34 for Cd and 0.318 for Pb. Values observed were higher than those found in suburban red fox and therefore, may represent an important bioindicator for the accumulation of toxic metals in urbanized habitats.

Toward high-speed 3D nonlinear soft tissue deformation simulations using Abaqus software.

PubMed

Idkaidek, Ashraf; Jasiuk, Iwona

2015-12-01

We aim to achieve a fast and accurate three-dimensional (3D) simulation of a porcine liver deformation under a surgical tool pressure using the commercial finite element software Abaqus. The liver geometry is obtained using magnetic resonance imaging, and a nonlinear constitutive law is employed to capture large deformations of the tissue. Effects of implicit versus explicit analysis schemes, element type, and mesh density on computation time are studied. We find that Abaqus explicit and implicit solvers are capable of simulating nonlinear soft tissue deformations accurately using first-order tetrahedral elements in a relatively short time by optimizing the element size. This study provides new insights and guidance on accurate and relatively fast nonlinear soft tissue simulations. Such simulations can provide force feedback during robotic surgery and allow visualization of tissue deformations for surgery planning and training of surgical residents.

Micro-finite-element method to assess elastic properties of trabecular bone at micro- and macroscopic level.

PubMed

Rieger, R; Auregan, J C; Hoc, T

2018-03-01

The objective of the present study is to assess the mechanical behavior of trabecular bone based on microCT imaging and micro-finite-element analysis. In this way two methods are detailed: (i) direct determination of macroscopic elastic property of trabecular bone; (ii) inverse approach to assess mechanical properties of trabecular bone tissue. Thirty-five females and seven males (forty-two subjects) mean aged (±SD) 80±11.7 years from hospitals of Assistance publique-Hôpitaux de Paris (AP-HP) diagnosed with osteoporosis following a femoral neck fracture due to a fall from standing were included in this study. Fractured heads were collected during hip replacement surgery. Standardized bone cores were removed from the femoral head's equator by a trephine in a water bath. MicroCT images acquisition and analysis were performed with CTan ® software and bone volume fraction was then determined. Micro-finite-element simulations were per-formed using Abaqus 6.9-2 ® software in order to determine the macroscopic mechanical behaviour of the trabecular bone. After microCT acquisition, a longitudinal compression test was performed and the experimental macroscopic Young's Modulus was extracted. An inverse approach based on the whole trabecular bone's mechanical response and micro-finite-element analysis was performed to determine microscopic mechanical properties of trabecular bone. In the present study, elasticity of the tissue was shown to be similar to that of healthy tissue but with a lower yield stress. Classical histomorphometric analysis form microCT imaging associated with an inverse micro-finite-element method allowed to assess microscopic mechanical trabecular bone parameters. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Concentrations of 17 elements, including mercury, and their relationship to fitness measures in arctic shorebirds and their eggs.

PubMed

Hargreaves, Anna L; Whiteside, Douglas P; Gilchrist, Grant

2010-07-15

Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and this is of particular concern in the arctic. However, little information exists on contaminant levels in arctic-breeding shorebirds, especially in Canada. We studied potential contaminants in three biparental shorebird species nesting in Nunavut, Canada: ruddy turnstones (Arenaria interpres), black-bellied plovers (Pluvialis squatarola) and semipalmated plovers (Charadrius semipalmatus). Blood, feathers and eggs were analyzed for As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn. We assessed whether element concentrations a) differed among species and sexes, b) were correlated among pairs and their eggs, and c) were related to fitness endpoints, namely body condition, blood-parasite load, nest survival days, and hatching success. Non-essential elements were found at lower concentrations than essential elements, with the exception of Hg. Maximum Hg levels in blood approached those associated with toxicological effects in other bird species, but other elements were well below known toxicological thresholds. Reproductive success was negatively correlated with paternal Hg and maternal Pb, although these effects were generally weak and varied among tissues. Element levels were positively correlated within pairs for blood-Hg (turnstones) and feather-Ni and Cr (semipalmated plovers); concentrations in eggs and maternal blood were never correlated. Concentrations of many elements differed among species, but there was no evidence that any species had higher overall exposure to non-essential metals. In conclusion, whereas we found little evidence that exposure to the majority of these elements is leading to declines of the species studied here, Hg levels were of potential concern and both Hg and Pb warrant further monitoring. Copyright 2010 Elsevier B.V. All rights reserved.

Evidence for contrasting accumulation pattern of cadmium in relation to other elements in Senilia senilis and Tagelus adansoni from the Bijagós archipelago, Guinea-Bissau.

PubMed

Catry, Teresa; Figueira, Paula; Carvalho, Lina; Monteiro, Rui; Coelho, Pedro; Lourenço, Pedro Miguel; Catry, Paulo; Tchantchalam, Quintino; Catry, Inês; Botelho, Maria J; Pereira, Eduarda; Granadeiro, José Pedro; Vale, Carlos

2017-11-01

Shellfish harvesting in intertidal areas is a widespread and economically important activity in many countries across West Africa. However, in some areas, there is virtually no information concerning the levels of contaminants (and other elements related to nutritional aspects) in the harvested species. We collected sediments and several individuals of the West African bloody cockle Senilia senilis and of the razor clam Tagelus adansoni during the dry season of 2015 nearby three islands in the Bijagós archipelago, Guinea-Bissau. Aluminium, Ca, Fe, Mg, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined in sediments and whole soft tissues of the two bivalves. Sediments showed uniformly low trace element concentrations, pointing to an ecosystem with low levels of trace element contamination. T. adansoni presented higher concentrations of most elements than S. senilis, with the exception of Cd that showed up to 40 times higher values in S. senilis than in T. adansoni from the same sites. Furthermore, Cd concentrations (25±8.7 mg kg -1 , dw) in S. senilis are clearly above the maximum level established for human consumption. Future studies should clarify whether biological factors are the major responsible for this unusual situation.

Real-time, haptics-enabled simulator for probing ex vivo liver tissue.

PubMed

Lister, Kevin; Gao, Zhan; Desai, Jaydev P

2009-01-01

The advent of complex surgical procedures has driven the need for realistic surgical training simulators. Comprehensive simulators that provide realistic visual and haptic feedback during surgical tasks are required to familiarize surgeons with the procedures they are to perform. Complex organ geometry inherent to biological tissues and intricate material properties drive the need for finite element methods to assure accurate tissue displacement and force calculations. Advances in real-time finite element methods have not reached the state where they are applicable to soft tissue surgical simulation. Therefore a real-time, haptics-enabled simulator for probing of soft tissue has been developed which utilizes preprocessed finite element data (derived from accurate constitutive model of the soft-tissue obtained from carefully collected experimental data) to accurately replicate the probing task in real-time.

Concentrations of trace and other elements in the organs of wild rats and birds from the Northern Guinea savanna of Nigeria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapu, M.M.; Schaeffer, D.J.; Akanya, H.O.

1991-01-01

In regions of human activities, where metal enter local aquatic ecosystems from the atmosphere and through wastewater outfalls, metal concentrations in food chains can exceed natural background levels and be above the threshold levels for sensitive species. Accordingly, metal levels in the organs and tissues of livestock and wildlife have been extensively studied. However, there are no reports of metal concentrations in the organs and tissues of wild animals from the Northern Guinea savanna of Nigeria. The mole rat (Africanthus niloticus, L) and village weaver bird (Ploceus cucullatus, L) contribute significantly to farm crop losses from sowing to harvest. Becausemore » there are no industries capable of causing metal contamination in the study area, the present study was undertaken to determine the natural baseline levels of metals for wild rats and birds from this environment.« less

Inferring the expression variability of human transposable element-derived exons by linear model analysis of deep RNA sequencing data.

PubMed

Zhang, Wensheng; Edwards, Andrea; Fan, Wei; Fang, Zhide; Deininger, Prescott; Zhang, Kun

2013-08-28

The exonization of transposable elements (TEs) has proven to be a significant mechanism for the creation of novel exons. Existing knowledge of the retention patterns of TE exons in mRNAs were mainly established by the analysis of Expressed Sequence Tag (EST) data and microarray data. This study seeks to validate and extend previous studies on the expression of TE exons by an integrative statistical analysis of high throughput RNA sequencing data. We collected 26 RNA-seq datasets spanning multiple tissues and cancer types. The exon-level digital expressions (indicating retention rates in mRNAs) were quantified by a double normalized measure, called the rescaled RPKM (Reads Per Kilobase of exon model per Million mapped reads). We analyzed the distribution profiles and the variability (across samples and between tissue/disease groups) of TE exon expressions, and compared them with those of other constitutive or cassette exons. We inferred the effects of four genomic factors, including the location, length, cognate TE family and TE nucleotide proportion (RTE, see Methods section) of a TE exon, on the exons' expression level and expression variability. We also investigated the biological implications of an assembly of highly-expressed TE exons. Our analysis confirmed prior studies from the following four aspects. First, with relatively high expression variability, most TE exons in mRNAs, especially those without exact counterparts in the UCSC RefSeq (Reference Sequence) gene tables, demonstrate low but still detectable expression levels in most tissue samples. Second, the TE exons in coding DNA sequences (CDSs) are less highly expressed than those in 3' (5') untranslated regions (UTRs). Third, the exons derived from chronologically ancient repeat elements, such as MIRs, tend to be highly expressed in comparison with those derived from younger TEs. Fourth, the previously observed negative relationship between the lengths of exons and the inclusion levels in transcripts is also true for exonized TEs. Furthermore, our study resulted in several novel findings. They include: (1) for the TE exons with non-zero expression and as shown in most of the studied biological samples, a high TE nucleotide proportion leads to their lower retention rates in mRNAs; (2) the considered genomic features (i.e. a continuous variable such as the exon length or a category indicator such as 3'UTR) influence the expression level and the expression variability (CV) of TE exons in an inverse manner; (3) not only the exons derived from Alu elements but also the exons from the TEs of other families were preferentially established in zinc finger (ZNF) genes.

Chemical contaminants in gray whales (eschichtius robustus) stranded in Alaska, Washington, and California, USA. Technical memo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varanasi, U.; Stein, J.E.; Tilbury, K.L.

1993-08-01

The concentrations of chlorinated hydrocarbons (CHs) such as polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethanes (DDTs), 1,1-dichloro-2,2-bis(p- chlorophenyl) ethenes (DDEs), and chlordanes, and essential (e.g., zinc, selenium, copper) and toxic (e.g., mercury, lead) elements were measured in tissues and stomach contents from 22 gray whales (Eschrichtius robustus) stranded between 1988 and 1991. The stranding sites ranged from the relatively pristine areas of Kodiak Island, Alaska, to more urbanized areas in Puget Sound, Washington, and San Francisco Bay, California, with the majority of the sites on the Washington outer coast and in Puget Sound. Similar to concentrations in tissues, no significant differences weremore » observed in concentrations of elements in stomach contents between whales stranded in Puget Sound and whales stranded at the more pristine sites. The lack of data from apparently healthy gray whales limits the assessment of whether the levels of anthropogenic contaminants found in tissues may have deleterious effects on the health of gray whales.« less

PIXE analysis of tumors and localization behavior of a lanthanide in nude mice

NASA Astrophysics Data System (ADS)

Chang, Pei-Jiun; Yang, Czau-Siung; Chou, Ming-Ji; Wei, Chau-Chin; Hsu, Chu-Chung; Wang, Chia-Yu

1984-04-01

We have used particle induced X-ray emission (PIXE) to analyze the elemental compositions and uptakes of a lanthanide, yttrium in this report, in tumors and normal tissues of nude mice. A small amount of yttrium nitrate was injected into nude mice with tumors. Samples of normal and malignant tissues taken from these mice were bombarded by the 2 MeV proton beam from a 3 MeV Van de Graaff accelerator with a Ge detector system to determine the relative elemental compositions of tissues and the relative concentrations of yttrium taken up by these tissues. We found that the uptakes of yttrium by tumors were at least five times more than those by normal tissues. Substantial differences were often observed between the trace element weight (or concentration) pattern of the cancerous and normal tissues. The present result is compared with human tissues.

Transposition of the maize transposable element Ac in barley (Hordeum vulgare L.).

PubMed

Scholz, S; Lörz, H; Lütticke, S

2001-01-01

Transposition of the maize autonomous element Ac (Activator) was investigated in barley (Hordeum vulgare L.) with the aim of developing a transposon tagging system for the latter. The Ac element was introduced into meristematic tissue of barley by microprojectile bombardment. Transposon activity was then examined in the resulting transgenic plants. Multiple excision events were detected in leaf tissue of all plant lines. The mobile elements generated empty donor sites with small DNA sequence alterations, similar to those found in maize. Reintegration of Ac at independent genomic loci in somatic tissue was demonstrated by isolation of new element-flanking regions by AIMS-PCR (amplification of insertion-mutagenized sites). In addition, transmission of transposed Ac elements to progeny plants was confirmed. The results indicate that the introduced Ac element is able to transpose in barley. This is a first step towards the establishment of a transposon tagging system in this economically important crop.

The influence of combined magnesium and vanadate administration on the level of some elements in selected rat organs: V-Mg interactions and the role of iron-essential protein (DMT-1) in the mechanism underlying altered tissues iron level.

PubMed

Scibior, Agnieszka; Adamczyk, Agnieszka; Gołębiowska, Dorota; Niedźwiecka, Irmina; Fornal, Emilia

2014-04-01

The effect of 12 week co-administration of sodium metavanadate (SMV) and magnesium sulfate (MS) on the levels of some elements in selected rats' organs and an attempt to elucidate a role of divalent metal transporter 1 (DMT-1) in the mechanism(s) of the SMV-induced disorders in some tissue Fe homeostasis were studied. SMV taken up separately or in combination with MS may pose a risk of the rise and shortage of the total hepatic and splenic Fe and Cu contents, respectively, cerebral Fe deficiency, splenic Ca deposition, and the hepatic, renal, and cerebral DMT-1 down-regulation. When administered alone, SMV may also cause the decrease in the total renal Fe and Cu contents. A visible protective effect of Mg against the renal and cerebral V accumulation and the decrease in the renal Fe and Cu contents during the SMV-MS co-administration together with our previous findings suggest a beneficial role of Mg at SMV exposure. Further, the SMV-induced fall in total iron binding capacity (TIBC), reported previously, and its correlations with the hepatic, splenic, and cerebral Fe levels allow us to suggest that diminished TIBC could be partly involved in the mechanism(s) responsible for the dramatic redistribution of Fe in those tissues. Finally, DMT-1, which potentially could participate in the hepatic non-transferrin Fe-bound uptake, does not play a significant role in this process indicating the need for studying other Fe transporters to more precisely elucidate molecular mechanism(s) underlying the hepatic Fe loading in our experimental conditions.

Do fossil vertebrate biominerals hold the key to the Palaeozoic climate?

NASA Astrophysics Data System (ADS)

Žigaitė, Ž.

2012-04-01

Fossil vertebrate hard tissues - teeth and dermoskeleton - are considered among the most geochemically stable biominerals, and therefore are widely used for palaeoenvironmental and palaeoclimatic reconstructions. Elemental and isotopic compositions of fossil dental tissues may provide unique palaeoenvironmental information, ranging from the diet and trophic positions on a food chain, to the palaeosalinity and water temperatures of ancient seas. However, the post-mortem alteration and re-crystallisation of fossil hard tissues may hamper these interpretations. Chemical composition and isotopic equilibrium of the biomineral change readily at any time from the earliest diagenesis to the final laboratory acid treatment during the fossil preparation. This is why particular attention shall be given to the preservation of fossil tissues, evaluating carefully the level of possible alteration in the primary geochemical composition. Pre-evaluation of fossil preservation can be made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections using Energy Dispersive X-ray Spectroscopy (EDS), and help to preview the chemical composition of biomineral. The Electron Backscatter Diffractometry (EBSD) is useful to examine the cristallinity and possible structural alterations. In addition, rare earth element (REE) abundances can be measured in situ within the fine fossil tissues (such as enamel) using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS), giving evidence on the selective geochemical resilience between separate vertebrate hard tissues. Therefore, in order to decipher the geochemical signal correctly, the evaluation of preservation is a necessary starting point to any further studies of fossil biomineral geochemistry.

Sequence Requirements of the 5-Enolpyruvylshikimate-3-phosphate Synthase 5[prime]-Upstream Region for Tissue-Specific Expression in Flowers and Seedlings.

PubMed Central

Benfey, PN; Takatsuji, H; Ren, L; Shah, DM; Chua, NH

1990-01-01

We have analyzed expression from deletion derivatives of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) 5[prime]-upstream region in transgenic petunia flowers and seedlings. In seedlings, expression was strongest in root cortex cells and in trichomes. High-level expression in petals and in seedling roots was conferred by large (>500 base-pair) stretches of sequence, but was lost when smaller fragments were analyzed individually. This apparent requirement for extensive sequence suggests that combinations of cis-elements that are widely separated control tissue-specific expression from the EPSPS promoter. We have also used the high-level, petal-specific expression of the EPSPS promoter to change petal color in two mutant petunia lines. PMID:12354968

Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium, and lead in the liver and kidneys of dogs according to age, gender, and the occurrence of chronic kidney disease

PubMed Central

Mainzer, Barbara; Lahrssen-Wiederholt, Monika; Schafft, Helmut; Palavinskas, Richard; Breithaupt, Angele; Zentek, Jürgen

2015-01-01

This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations. PMID:25234328

Effects of Dietary Selenium Against Lead Toxicity on mRNA Levels of 25 Selenoprotein Genes in the Cartilage Tissue of Broiler Chicken.

PubMed

Gao, H; Liu, C P; Song, S Q; Fu, J

2016-07-01

The interactions between the essential element selenium (Se) and the toxic element lead (Pb) have been reported extensively; however, little is known about the effect of Se on Pb toxicity and the expression pattern of selenoproteins in the cartilage of chicken. To investigate the effects of Se on Pb toxicity and the messenger RNA (mRNA) expressions of selenoproteins in cartilage tissue, an in vitro study was performed on 1-day-old broiler chickens (randomly allocated into four groups) with diet of different concentration of Se and Pb. After 90 days, the meniscus cartilage and sword cartilage tissue were examined for the mRNA levels of 25 selenoprotein genes. The results showed that Se and Pb influenced the expression of selenoprotein genes in the chicken cartilage tissue. In detail, Se could alleviate the downtrend of the expression of Gpx1, Gpx2, Gpx4, Txnrd2, Txnrd3, Dio1, Dio2, Seli, Selu, Sepx1, Selk, Selw, Selo, Selm, Sep15, Sepnn1, Sels, and Selt induced by Pb exposure in the meniscus cartilage. In the sword cartilage, Se alleviated the downtrend of the expression of Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Dio2, Dio3, Seli, Selh, SPS2, Sepx1, Selk, Selw, Selo, Selm, Sep15, Selpb, Sepn1, and Selt induced by Pb exposure. The present study provided some compensated data about the roles of Se against Pb toxicity in the regulation of selenoprotein expression.

Population and clinical genetics of human transposable elements in the (post) genomic era

PubMed Central

Rishishwar, Lavanya; Wang, Lu; Clayton, Evan A.; Mariño-Ramírez, Leonardo; McDonald, John F.; Jordan, I. King

2017-01-01

ABSTRACT Recent technological developments—in genomics, bioinformatics and high-throughput experimental techniques—are providing opportunities to study ongoing human transposable element (TE) activity at an unprecedented level of detail. It is now possible to characterize genome-wide collections of TE insertion sites for multiple human individuals, within and between populations, and for a variety of tissue types. Comparison of TE insertion site profiles between individuals captures the germline activity of TEs and reveals insertion site variants that segregate as polymorphisms among human populations, whereas comparison among tissue types ascertains somatic TE activity that generates cellular heterogeneity. In this review, we provide an overview of these new technologies and explore their implications for population and clinical genetic studies of human TEs. We cover both recent published results on human TE insertion activity as well as the prospects for future TE studies related to human evolution and health. PMID:28228978

Linking trace element variations with macronutrients and major cations in marine mussels Mytilus edulis and Perna viridis.

PubMed

Liu, Fengjie; Wang, Wen-Xiong

2015-09-01

Marine mussels have long been used as biomonitors of contamination of trace elements, but little is known about whether variation in tissue trace elements is significantly associated with those of macronutrients and major cations. The authors examined the variability of macronutrients and major cations and their potential relationships with bioaccumulation of trace elements. The authors analyzed the concentrations of macronutrients (C, N, P, S), major cations (Na, Mg, K, Ca), and trace elements (Al, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Pb) in the whole soft tissues of marine mussels Mytilus edulis and Perna viridis collected globally from 21 sites. The results showed that 12% to 84% of the variances in the trace elements was associated with major cations, and the tissue concentration of major cations such as Na and Mg in mussels was a good proxy for ambient seawater concentrations of the major cations. Specifically, bioaccumulation of most of the trace elements was significantly associated with major cations, and the relationships of major cations with trace cations and trace oxyanions were totally opposite. Furthermore, 14% to 69% of the variances in the trace elements were significantly associated with macronutrients. Notably, more than half of the variance in the tissue concentrations of As, Cd, V, Ba, and Pb was explained by the variance in macronutrients in one or both species. Because the tissue macronutrient concentrations were strongly associated with animal growth and reproduction, the observed coupling relationships indicated that these biological processes strongly influenced the bioaccumulation of some trace elements. The present study indicated that simultaneous quantification of macronutrients and major cations with trace elements can improve the interpretation of biomonitoring data. © 2015 SETAC.

Palpation simulator with stable haptic feedback.

PubMed

Kim, Sang-Youn; Ryu, Jee-Hwan; Lee, WooJeong

2015-01-01

The main difficulty in constructing palpation simulators is to compute and to generate stable and realistic haptic feedback without vibration. When a user haptically interacts with highly non-homogeneous soft tissues through a palpation simulator, a sudden change of stiffness in target tissues causes unstable interaction with the object. We propose a model consisting of a virtual adjustable damper and an energy measuring element. The energy measuring element gauges energy which is stored in a palpation simulator and the virtual adjustable damper dissipates the energy to achieve stable haptic interaction. To investigate the haptic behavior of the proposed method, impulse and continuous inputs are provided to target tissues. If a haptic interface point meets with the hardest portion in the target tissues modeled with a conventional method, we observe unstable motion and feedback force. However, when the target tissues are modeled with the proposed method, a palpation simulator provides stable interaction without vibration. The proposed method overcomes a problem in conventional haptic palpation simulators where unstable force or vibration can be generated if there is a big discrepancy in material property between an element and its neighboring elements in target tissues.

Microgravity

NASA Image and Video Library

1998-10-10

Isolation of human mammary epithelial cells (HMEC) from breast cancer susceptible tissue; A: Duct element recovered from breast tissue digest. B: Outgrowth of cells from duct element in upper right corner cultured in a standard dish; most cells spontaneousely die during early cell divisions, but a few will establish long-term growth. C: Isolate of long-term frowth HMEC from outgrowth of duct element; cells shown soon after isolation and in early full-cell contact growth in culture in a dish. D: same long-term growth HMEC, but after 3 weeks in late full-cell contact growth in a continuous culture in a dish. Note attempts to reform duct elements but this in two demensions in a dish rather than in three dimensions in tissue. NASA's Marshall Space Flight Center (MSFC) is sponsoring research with Bioreactors, rotating wall vessels designed to grow tissue samples in space, to understand how breast cancer works. This ground-based work studies the growth and assembly of human mammary epithelial cell (HMEC) from breast cancer susceptible tissue. Radiation can make the cells cancerous, thus allowing better comparisons of healthy vs. tunorous tissue. Credit: Dr. Robert Richmond, NASA/Marshall Space Flight Center (MSFC).

Trace Elemental Imaging of Rare Earth Elements Discriminates Tissues at Microscale in Flat Fossils

PubMed Central

Gueriau, Pierre; Mocuta, Cristian; Dutheil, Didier B.; Cohen, Serge X.; Thiaudière, Dominique; Charbonnier, Sylvain; Clément, Gaël; Bertrand, Loïc

2014-01-01

The interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies. PMID:24489809

Trace elemental imaging of rare earth elements discriminates tissues at microscale in flat fossils.

PubMed

Gueriau, Pierre; Mocuta, Cristian; Dutheil, Didier B; Cohen, Serge X; Thiaudière, Dominique; Charbonnier, Sylvain; Clément, Gaël; Bertrand, Loïc

2014-01-01

The interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies.

Multiscale Modeling of Cardiac Cellular Energetics

PubMed Central

BASSINGTHWAIGHTE, JAMES B.; CHIZECK, HOWARD J.; ATLAS, LES E.; QIAN, HONG

2010-01-01

Multiscale modeling is essential to integrating knowledge of human physiology starting from genomics, molecular biology, and the environment through the levels of cells, tissues, and organs all the way to integrated systems behavior. The lowest levels concern biophysical and biochemical events. The higher levels of organization in tissues, organs, and organism are complex, representing the dynamically varying behavior of billions of cells interacting together. Models integrating cellular events into tissue and organ behavior are forced to resort to simplifications to minimize computational complexity, thus reducing the model’s ability to respond correctly to dynamic changes in external conditions. Adjustments at protein and gene regulatory levels shortchange the simplified higher-level representations. Our cell primitive is composed of a set of subcellular modules, each defining an intracellular function (action potential, tricarboxylic acid cycle, oxidative phosphorylation, glycolysis, calcium cycling, contraction, etc.), composing what we call the “eternal cell,” which assumes that there is neither proteolysis nor protein synthesis. Within the modules are elements describing each particular component (i.e., enzymatic reactions of assorted types, transporters, ionic channels, binding sites, etc.). Cell subregions are stirred tanks, linked by diffusional or transporter-mediated exchange. The modeling uses ordinary differential equations rather than stochastic or partial differential equations. This basic model is regarded as a primitive upon which to build models encompassing gene regulation, signaling, and long-term adaptations in structure and function. During simulation, simpler forms of the model are used, when possible, to reduce computation. However, when this results in error, the more complex and detailed modules and elements need to be employed to improve model realism. The processes of error recognition and of mapping between different levels of model form complexity are challenging but are essential for successful modeling of large-scale systems in reasonable time. Currently there is to this end no established methodology from computational sciences. PMID:16093514

Finite-element simulation of blood perfusion in muscle tissue during compression and sustained contraction.

PubMed

Vankan, W J; Huyghe, J M; Slaaf, D W; van Donkelaar, C C; Drost, M R; Janssen, J D; Huson, A

1997-09-01

Mechanical interaction between tissue stress and blood perfusion in skeletal muscles plays an important role in blood flow impediment during sustained contraction. The exact mechanism of this interaction is not clear, and experimental investigation of this mechanism is difficult. We developed a finite-element model of the mechanical behavior of blood-perfused muscle tissue, which accounts for mechanical blood-tissue interaction in maximally vasodilated vasculature. Verification of the model was performed by comparing finite-element results of blood pressure and flow with experimental measurements in a muscle that is subject to well-controlled mechanical loading conditions. In addition, we performed simulations of blood perfusion during tetanic, isometric contraction and maximal vasodilation in a simplified, two-dimensional finite-element model of a rat calf muscle. A vascular waterfall in the venous compartment was identified as the main cause for blood flow impediment both in the experiment and in the finite-element simulations. The validated finite-element model offers possibilities for detailed analysis of blood perfusion in three-dimensional muscle models under complicated loading conditions.

Analysis of shear wave propagation derived from MR elastography in 3D thigh skeletal muscle using subject specific finite element model.

PubMed

Dao, Tien Tuan; Pouletaut, Philippe; Charleux, Fabrice; Tho, Marie-Christine Ho Ba; Bensamoun, Sabine

2014-01-01

The purpose of this study was to develop a subject specific finite element model derived from MRI images to numerically analyze the MRE (magnetic resonance elastography) shear wave propagation within skeletal thigh muscles. A sagittal T2 CUBE MRI sequence was performed on the 20-cm thigh segment of a healthy male subject. Skin, adipose tissue, femoral bone and 11 muscles were manually segmented in order to have 3D smoothed solid and meshed models. These tissues were modeled with different constitutive laws. A transient modal dynamics analysis was applied to simulate the shear wave propagation within the thigh tissues. The effects of MRE experimental parameters (frequency, force) and the muscle material properties (shear modulus: C10) were analyzed through the simulated shear wave displacement within the vastus medialis muscle. The results showed a plausible range of frequencies (from 90Hz to 120 Hz), which could be used for MRE muscle protocol. The wave amplitude increased with the level of the force, revealing the importance of the boundary condition. Moreover, different shear displacement patterns were obtained as a function of the muscle mechanical properties. The present study is the first to analyze the shear wave propagation in skeletal muscles using a 3D subject specific finite element model. This study could be of great value to assist the experimenters in the set-up of MRE protocols.

High-Resolution Ultrasonic Imaging of Dento-Periodontal Tissues Using a Multi-Element Phased Array System.

PubMed

Nguyen, Kim-Cuong T; Le, Lawrence H; Kaipatur, Neelambar R; Zheng, Rui; Lou, Edmond H; Major, Paul W

2016-10-01

Intraoral ultrasonography uses high-frequency mechanical waves to study dento-periodontium. Besides the advantages of portability and cost-effectiveness, ultrasound technique has no ionizing radiation. Previous studies employed a single transducer or an array of transducer elements, and focused on enamel thickness and distance measurement. This study used a phased array system with a 128-element array transducer to image dento-periodontal tissues. We studied two porcine lower incisors from a 6-month-old piglet using 20-MHz ultrasound. The high-resolution ultrasonographs clearly showed the cross-sectional morphological images of the hard and soft tissues. The investigation used an integration of waveform analysis, travel-time calculation, and wavefield simulation to reveal the nature of the ultrasound data, which makes the study novel. With the assistance of time-distance radio-frequency records, we robustly justified the enamel-dentin interface, dentin-pulp interface, and the cemento-enamel junction. The alveolar crest level, the location of cemento-enamel junction, and the thickness of alveolar crest were measured from the images and compared favorably with those from the cone beam computed tomography with less than 10% difference. This preliminary and fundamental study has reinforced the conclusions from previous studies, that ultrasonography has great potential to become a non-invasive diagnostic imaging tool for quantitative assessment of periodontal structures and better delivery of oral care.

Comparison of screening-level and Monte Carlo approaches for wildlife food web exposure modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pastorok, R.; Butcher, M.; LaTier, A.

1995-12-31

The implications of using quantitative uncertainty analysis (e.g., Monte Carlo) and site-specific tissue residue data for wildlife exposure modeling were examined with data on trace elements at the Clark Fork River Superfund Site. Exposure of white-tailed deer, red fox, and American kestrel was evaluated using three approaches. First, a screening-level exposure model was based on conservative estimates of exposure parameters, including estimates of dietary residues derived from bioconcentration factors (BCFs) and soil chemistry. A second model without Monte Carlo was based on site-specific data for tissue residues of trace elements (As, Cd, Cu, Pb, Zn) in key dietary species andmore » plausible assumptions for habitat spatial segmentation and other exposure parameters. Dietary species sampled included dominant grasses (tufted hairgrass and redtop), willows, alfalfa, barley, invertebrates (grasshoppers, spiders, and beetles), and deer mice. Third, the Monte Carlo analysis was based on the site-specific residue data and assumed or estimated distributions for exposure parameters. Substantial uncertainties are associated with several exposure parameters, especially BCFS, such that exposure and risk may be greatly overestimated in screening-level approaches. The results of the three approaches are compared with respect to realism, practicality, and data gaps. Collection of site-specific data on trace elements concentrations in plants and animals eaten by the target wildlife receptors is a cost-effective way to obtain realistic estimates of exposure. Implications of the results for exposure and risk estimates are discussed relative to use of wildlife exposure modeling and evaluation of remedial actions at Superfund sites.« less

Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds.

PubMed

Hargreaves, Anna L; Whiteside, Douglas P; Gilchrist, Grant

2011-09-01

Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates and shorebird blood to assess evidence for bioconcentration and biomagnification within the Arctic-based food chain. We tested whether elements in blood, feathers and eggs of six shorebird species (Pluvialis squatarola, Calidris alpina, C. fuscicollis, Phalaropus fulicarius, Charadrius semipalmatus, and Arenaria interpres) were related to fitness endpoints: adult body condition, blood-parasite load, egg size, eggshell thickness, nest duration, and hatching success. To facilitate comparison to other sites, we summarise the published data on toxic metals in shorebird blood and egg contents. Element concentrations and invertebrate composition differed strongly among habitats, and habitat use and element concentrations differed among shorebird species. Hg, Se, Cd, Cu, and Zn bioconcentrated from soil to invertebrates, and Hg, Se and Fe biomagnified from invertebrates to shorebird blood. As, Ni, Pb, Co and Mn showed significant biodilution from soil to invertebrates to shorebirds. Soil element levels were within Canadian guidelines, and invertebrate Hg levels were below dietary levels suggested for the protection of wildlife. However, maximum Hg in blood and eggs approached levels associated with toxicological effects and Hg-pollution in other bird species. Parental blood-Hg was negatively related to egg volume, although the relationship varied among species. No other elements approached established toxicological thresholds. In conclusion, whereas we found little evidence that exposure to elements at this site is leading to the declines of the species studied, Hg, as found elsewhere in the Canadian Arctic, is of potential concern for breeding bird populations. Copyright © 2011 Elsevier B.V. All rights reserved.

Wide range of metallic and organic contaminants in various tissues of the Antarctic prion, a planktonophagous seabird from the Southern Ocean.

PubMed

Fromant, Aymeric; Carravieri, Alice; Bustamante, Paco; Labadie, Pierre; Budzinski, Hélène; Peluhet, Laurent; Churlaud, Carine; Chastel, Olivier; Cherel, Yves

2016-02-15

Trace elements (n=14) and persistent organic pollutants (POPs, n=30) were measured in blood, liver, kidney, muscle and feathers of 10 Antarctic prions (Pachyptila desolata) from Kerguelen Islands, southern Indian Ocean, in order to assess their concentrations, tissue distribution, and inter-tissue and inter-contaminant relationships. Liver, kidney and feathers presented the highest burdens of arsenic, cadmium and mercury, respectively. Concentrations of cadmium, copper, iron, and zinc correlated in liver and muscle, suggesting that uptake and pathways of metabolism and storage were similar for these elements. The major POPs were 4,4'-DDE, mirex, PCB-153 and PCB-138. The concentrations and tissue distribution patterns of environmental contaminants were overall in accordance with previous results in other seabirds. Conversely, some Antarctic prions showed surprisingly high concentrations of BDE-209. This compound has been rarely observed in seabirds before, and its presence in Antarctic prions could be due to the species feeding habits or to the ingestion of plastic debris. Overall, the study shows that relatively lower trophic level seabirds (zooplankton-eaters) breeding in the remote southern Indian Ocean are exposed to a wide range of environmental contaminants, in particular cadmium, selenium and some emerging-POPs, which merits further toxicological investigations. Copyright © 2015 Elsevier B.V. All rights reserved.

Metal elements in tissue with dental peri-implantitis: a pilot study.

PubMed

Fretwurst, Tobias; Buzanich, Guenter; Nahles, Susanne; Woelber, Johan Peter; Riesemeier, Heinrich; Nelson, Katja

2016-09-01

Dental peri-implantitis is characterized by a multifactorial etiology. The role of metal elements as an etiological factor for peri-implantitis is still unclear. The aim of this study was to investigate the incidence of metal elements in bone and mucosal tissues around dental Grade 4 CP titanium implants with signs of peri-implantitis in human patients. In this prospective pilot study, all patients were enrolled consecutively in two study centers. Bone and soft tissue samples of patients with peri-implantitis with indication for explantation were analyzed for the incidence of different elements (Ca, P, Ti, Fe) by means of synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) and polarized light microscopy (PLM). The existence of macrophages and lymphocytes in the histologic specimens was analyzed. Biopsies of 12 patients (seven bone samples, five mucosal samples) were included and analyzed. In nine of the 12 samples (75%), the SRXRF examination revealed the existence of titanium (Ti) and an associated occurrence with Iron (Fe). Metal particles were detected in peri-implant soft tissue using PLM. In samples with increased titanium concentration, lymphocytes were detected, whereas M1 macrophages were predominantly seen in samples with metal particles. Titanium and Iron elements were found in soft and hard tissue biopsies retrieved from peri-implantitis sites. Further histologic and immunohistochemical studies need to clarify which specific immune reaction metal elements/particles induce in dental peri-implant tissue. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Elemental concentration analysis in prostate tissues using total reflection X-ray fluorescence

NASA Astrophysics Data System (ADS)

Leitão, R. G.; Palumbo, A.; Souza, P. A. V. R.; Pereira, G. R.; Canellas, C. G. L.; Anjos, M. J.; Nasciutti, L. E.; Lopes, R. T.

2014-02-01

Prostate cancer (PCa) currently represents the second most prevalent malignant neoplasia in men, representing 21% of all cancer cases. Benign Prostate Hyperplasia (BPH) is an illness prevailing in men above the age of 50, close to 90% after the age of 80. The prostate presents a high zinc concentration, about 10-fold higher than any other body tissue. In this work, samples of human prostate tissues with cancer, BPH and normal tissue were analyzed utilizing total reflection X-ray fluorescence spectroscopy using synchrotron radiation technique (SR-TXRF) to investigate the differences in the elemental concentrations in these tissues. SR-TXRF analyses were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. It was possible to determine the concentrations of the following elements: P, S, K, Ca, Fe, Cu, Zn and Rb. By using Mann-Whitney U test it was observed that almost all elements presented concentrations with significant differences (α=0.05) between the groups studied.

Correlation and toxicological inference of trace elements in tissues from stranded and free-ranging bottlenose dolphins (Tursiops truncatus).

PubMed

Stavros, Hui-Chen W; Stolen, Megan; Durden, Wendy Noke; McFee, Wayne; Bossart, Gregory D; Fair, Patricia A

2011-03-01

The significance of metal concentrations in marine mammals is not well understood and relating concentrations between stranded and free-ranging populations has been difficult. In order to predict liver concentrations in free-ranging dolphins, we examined concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, total Hg (THg), V, Zn) in skin and liver of stranded bottlenose dolphins (Tursiops truncatus) from the South Carolina (SC) coast and the Indian River Lagoon, Florida (FL) during 2000-2008. Significantly higher concentrations of Zn, Fe, Se, Al, Cu and THg were found in skin while liver exhibited significantly higher Cu, Fe, Mn and THg concentrations for both study sites. Mean skin concentrations of Cu and Mn were significantly higher in SC dolphins while higher concentrations of THg and V were found in FL dolphins. In addition, liver tissues in SC dolphins exhibited significantly higher As concentrations while higher Fe, Pb, Se, THg, and V levels were found in FL dolphins. Two elements (Cu and THg) showed significant age-related correlations with skin concentration while five elements (Cu, Se, THg, Zn and V) showed age-related correlations with liver concentrations. Geographic location influenced age-related accumulation of several trace elements and age-related accumulation of THg in hepatic tissue was observed for both sites to have the highest correlations (r² = 0.90SC; r² = 0.69FL). Mean THg concentration in liver was about 10 times higher in FL dolphins (330 μg g⁻¹ dw) than those samples from SC dolphins (34.3 μg g⁻¹ dw). The mean molar ratio of Hg to Se was 0.93 ± 0.32 and 1.08 ± 0.38 for SC and FL dolphins, respectively. However, the Hg:Se ratio varied with age as much lower ratios (0.2-0.4) were found in younger animals. Of the 18 measured elements, only THg was significantly correlated in skin and liver of stranded dolphins and skin of free-ranging dolphins from both sites suggesting that skin may be useful in predicting Hg concentrations in liver tissue of free-ranging dolphins. Results indicate that 33% of the stranded and 15% of the free-ranging dolphins from FL exceed the minimum 100 μg g⁻¹ wet weight (ww) (~ 400 dw) Hg threshold for hepatic damage while none from SC reached this level. Hepatic concentrations of As in SC dolphins and V in FL dolphins were also highly correlated with skin concentrations which may have some regional specificity predictive value. The present study provides the first application of trace element concentrations derived from stranded bottlenose dolphins to predict liver concentrations in free-ranging populations. Copyright © 2010. Published by Elsevier Ltd.

Computational aspects in mechanical modeling of the articular cartilage tissue.

PubMed

Mohammadi, Hadi; Mequanint, Kibret; Herzog, Walter

2013-04-01

This review focuses on the modeling of articular cartilage (at the tissue level), chondrocyte mechanobiology (at the cell level) and a combination of both in a multiscale computation scheme. The primary objective is to evaluate the advantages and disadvantages of conventional models implemented to study the mechanics of the articular cartilage tissue and chondrocytes. From monophasic material models as the simplest form to more complicated multiscale theories, these approaches have been frequently used to model articular cartilage and have contributed significantly to modeling joint mechanics, addressing and resolving numerous issues regarding cartilage mechanics and function. It should be noted that attentiveness is important when using different modeling approaches, as the choice of the model limits the applications available. In this review, we discuss the conventional models applicable to some of the mechanical aspects of articular cartilage such as lubrication, swelling pressure and chondrocyte mechanics and address some of the issues associated with the current modeling approaches. We then suggest future pathways for a more realistic modeling strategy as applied for the simulation of the mechanics of the cartilage tissue using multiscale and parallelized finite element method.

A two-phase model of plantar tissue: a step toward prediction of diabetic foot ulceration.

PubMed

Sciumè, G; Boso, D P; Gray, W G; Cobelli, C; Schrefler, B A

2014-11-01

A new computational model, based on the thermodynamically constrained averaging theory, has been recently proposed to predict tumor initiation and proliferation. A similar mathematical approach is proposed here as an aid in diabetic ulcer prevention. The common aspects at the continuum level are the macroscopic balance equations governing the flow of the fluid phase, diffusion of chemical species, tissue mechanics, and some of the constitutive equations. The soft plantar tissue is modeled as a two-phase system: a solid phase consisting of the tissue cells and their extracellular matrix, and a fluid one (interstitial fluid and dissolved chemical species). The solid phase may become necrotic depending on the stress level and on the oxygen availability in the tissue. Actually, in diabetic patients, peripheral vascular disease impacts tissue necrosis; this is considered in the model via the introduction of an effective diffusion coefficient that governs transport of nutrients within the microvasculature. The governing equations of the mathematical model are discretized in space by the finite element method and in time domain using the θ-Wilson Method. While the full mathematical model is developed in this paper, the example is limited to the simulation of several gait cycles of a healthy foot. Copyright © 2014 John Wiley & Sons, Ltd.

Assessing behind armor blunt trauma in accordance with the National Institute of Justice Standard for Personal Body Armor Protection using finite element modeling.

PubMed

Roberts, Jack C; Ward, Emily E; Merkle, Andrew C; O'Connor, James V

2007-05-01

To assess the possibility of injury as a result of behind armor blunt trauma (BABT), a study was undertaken to determine the conditions necessary to produce the 44-mm clay deformation as set forth in the National Institute of Justice (NIJ) Standard 0101.04. These energy levels were then applied to a three-dimensional Human Torso Finite Element Model (HTFEM) with soft armor vest. An examination will be made of tissue stresses to determine the effects of the increased kinetic energy levels on the probability of injury. A clay finite element model (CFEM) was created with a material model that required nonlinear properties for clay. To determine these properties empirically, the results from the CFEM were matched with experimental drop tests. A soft armor vest was modeled over the clay to create a vest over clay block finite element model (VCFEM) and empirical methods were again used to obtain material properties for the vest from experimental ballistic testing. Once the properties for the vest and clay had been obtained, the kinetic energy required to produce a 44-mm deformation in the VCFEM was determined through ballistic testing. The resulting kinetic energy was then used in the HTFEM to evaluate the probability of BABT. The VCFEM, with determined clay and vest material properties, was exercised with the equivalent of a 9-mm (8-gm) projectile at various impact velocities. The 44-mm clay deformation was produced with a velocity of 785 m/s. This impact condition (9-mm projectile at 785 m/s) was used in ballistic exercises of the HTFEM, which was modeled with high-strain rate human tissue properties for the organs. The impact zones were over the sternum anterior to T6 and over the liver. The principal stresses in both soft and hard tissue at both locations exceeded the tissue tensile strength. This study indicates that although NIJ standard 0101.04 may be a good guide to soft armor failure, it may not be as good a guide in BABT, especially at large projectile kinetic energies. Further studies, both numerical and experimental, are needed to assist in predicting injury using the NIJ standard.

Seasoning ingredients in a medium-fat diet regulate lipid metabolism in peripheral tissues via the hypothalamic-pituitary axis in growing rats.

PubMed

Tanaka, Mitsuru; Yasuoka, Akihito; Yoshinuma, Haruka; Saito, Yoshikazu; Asakura, Tomiko; Tanabe, Soichi

2018-03-01

We fed rats noodle (N) -diet containing 30 wt.% instant noodle with a 26% fat-to-energy ratio for 30 days (N-group). Compared with rats that were fed the same amount of nutrients (C-group), the N-group showed lower liver triacylglycerol levels and higher fecal cholesterol levels. We then analyzed transcriptome of the hypothalamic-pituitary (HP), the liver and the white adipose tissue (WAT). Thyroid stimulating hormone (Tshb), and its partner, glycoprotein hormone genes were up-regulated in the HP of N-group. Sterol regulatory element binding transcription factors were activated in the liver of N-group, while an up-regulation of the angiogenic signal occurred in the WAT of N-group. N-group showed higher urine noradrenaline (NA) level suggesting that these tissue signals are regulated by NA and Tshb. The N-diet contains 0.326 wt.% glutamate, 0.00236 wt.% 6-shogaol and Maillard reaction products. Our results suggest that these ingredients may affect lipid homeostasis via the HP axis.

Multiple high-intensity focused ultrasound probes for kidney-tissue ablation.

PubMed

Häcker, Axel; Chauhan, Sunita; Peters, Kristina; Hildenbrand, Ralf; Marlinghaus, Ernst; Alken, Peter; Michel, Maurice Stephan

2005-10-01

To investigate kidney-tissue ablation by high-intensity focused ultrasound (HIFU) using multiple and single probes. Ultrasound beams (1.75 MHz) produced by a piezoceramic element (focal distance 80 mm) were focused at the center of renal parenchyma. One of the three probes (mounted on a jig) could also be used for comparison with a single probe at comparable power ratings. Lesion dimensions were examined in perfused and unperfused ex vivo porcine kidneys at different power levels (40, 60, and 80 W) and treatment times (4, 6, and 8 seconds). At identical power levels, the lesions induced by multiple probes were larger than those induced by a single probe. Lesion size increased with increasing pulse duration and generator power. The sizes and shapes of the lesions were predictably repeatable in all samples. Lesions in perfused kidneys were smaller than those in unperfused kidneys. Ex vivo, kidney-tissue ablation by means of multiple HIFU probes offers significant advantages over single HIFU probes in respect of lesion size and formation. These advantages need to be confirmed by tests in vivo at higher energy levels.

Interaction between carcinogenic and anti-carcinogenic trace elements in the scalp hair samples of different types of Pakistani female cancer patients.

PubMed

Wadhwa, Sham Kumar; Kazi, Tasneem Gul; Afridi, Hassan Imran; Talpur, Farah Naz; Naeemullah

2015-01-15

It was investigated that carcinogenic processes are linked with the imbalances of essential trace and toxic elements in body fluid and tissues of human. In this study, the relationship between carcinogenic elements, arsenic (As), cadmium (Cd), and nickel (Ni), and anti-carcinogenic elements, selenium (Se) and zinc (Zn), in the scalp hair of different female cancer patients (breast, cervix, mouth and ovarian) was studied. The scalp hair samples were collected from cancer patients and referent female subjects of the same age group and socioeconomic status. The scalp hair samples were oxidized by 65% nitric acid and 30% hydrogen peroxide by microwave oven and analyzed by atomic absorption spectrometry. The validity and accuracy of the methodology were checked using certified reference material of human hair (BCR 397). The mean concentrations of As, Cd, and Ni were found to be significantly higher in the scalp hair samples of cancerous patients as compared to referents, while reverse results were obtained in the case of Zn and Se (p<0.01). The study revealed that low level of trace elements (Se, Zn) and high level of heavy elements (As, Cd, and Ni) were associated with increased risk of cancer. Copyright © 2014 Elsevier B.V. All rights reserved.

Trace elements in Antarctic fish species and the influence of foraging habitats and dietary habits on mercury levels.

PubMed

Goutte, Aurélie; Cherel, Yves; Churlaud, Carine; Ponthus, Jean-Pierre; Massé, Guillaume; Bustamante, Paco

2015-12-15

This study aims at describing and interpreting concentration profiles of trace elements in seven Antarctic fish species (N=132 specimens) off Adélie Land. Ichthyofauna plays a key role in the Antarctic ecosystem, as they occupy various ecological niches, including cryopelagic (ice-associated), pelagic, and benthic habitats. Firstly, trace element levels in the studied specimens were similar to those previously observed in fish from the Southern Ocean. Apart from manganese and zinc, concentrations of arsenic, cadmium, copper, iron, mercury (Hg), nickel, selenium and silver differed among fish species. Muscle δ(13)C and δ(15)N values were determined to investigate whether the fish foraging habitats and dietary habits could explain Hg levels. Species and foraging habitat (δ(13)C) were strong predictors for variations of Hg concentrations in muscle tissues. The highest Hg contamination was found in shallow benthic fish compared to cryopelagic and pelagic fish. This pattern was likely due to the methylation of Hg in the coastal sediment and the photodemethylation by ultraviolet radiation in surface waters. Copyright © 2015 Elsevier B.V. All rights reserved.

[Effect of atmospheric CO2 concentration and nitrogen application level on absorption and transportation of nutrient elements in oilseed rape].

PubMed

Wang, Wen-ming; Zhang, Zhen-hua; Song, Hai-xing; Liu, Qiang; Rong, Xiang-min; Guan, Chun-yun; Zeng, Jing; Yuan, Dan

2015-07-01

Effect of elevated atmospheric-CO2 (780 µmol . mol-1) on the absorption and transportation of secondary nutrient elements (calcium, magnesium, sulphur) and micronutrient elements (iron, manganese, zinc, molybdenum and boron) in oilseed rape at the stem elongation stage were studied by greenhouse simulated method. Compared with the ambient CO2 condition, the content of Zn in stem was increased and the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with no nitrogen (N) application; the contents of Ca, S, B and Zn were increased, and the contents of Mg, Mn, Mo and Fe were decreased under the elevated atmospheric CO2 with N application (0.2 g N . kg-1 soil); except the content of Mo in leaf was increased, the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with two levels of N application. Compared with the ambient CO2 condition, the amounts of Ca and S relative to the total amount of secondary nutrient elements in stem and the amounts of B and Zn relative to the total amount of micronutrient elements in stem were increased under the elevated-CO2 treatment with both levels of N application, and the corresponding values of Mg, Fe, Mn and Mo were decreased; no-N application treatment increased the proportion of Ca distributed into the leaves, and the proportion of Mg distributed into leaves was increased by the normal-N application level; the proportions of Mn, Zn and Mo distributed into the leaves were increased at both N application levels. Without N application, the elevation of atmospheric CO2 increased the transport coefficients of SFe, Mo and SS,B, but decreased the transport coefficients of SMg,Fe, SMg, Mn and SS,Fe, indicating the proportions of Mo, S transported into the upper part of plant tissues was higher than that of Fe, and the corresponding value of B was higher than that observed for S, the corresponding value of Mg was higher than that of Fe and Mn. Under normal-N application, the elevation of atmospheric CO2 increased the transport coefficients of SMg,Fe, SMg,Mn and SS,B, but decreased the transport coefficients of SCa, Mg, SFe,Mo and SS,Fe indicating the proportions of Fe, Mn and Ca transported into the upper part of plant tissues was higher than that of Mg; the corresponding value of B was higher than that observed for S, the corresponding value of Fe was higher than that of Mo, and the corresponding value of S was higher than that of Fe.

Finite element dynamic analysis of soft tissues using state-space model.

PubMed

Iorga, Lucian N; Shan, Baoxiang; Pelegri, Assimina A

2009-04-01

A finite element (FE) model is employed to investigate the dynamic response of soft tissues under external excitations, particularly corresponding to the case of harmonic motion imaging. A solid 3D mixed 'u-p' element S8P0 is implemented to capture the near-incompressibility inherent in soft tissues. Two important aspects in structural modelling of these tissues are studied; these are the influence of viscous damping on the dynamic response and, following FE-modelling, a developed state-space formulation that valuates the efficiency of several order reduction methods. It is illustrated that the order of the mathematical model can be significantly reduced, while preserving the accuracy of the observed system dynamics. Thus, the reduced-order state-space representation of soft tissues for general dynamic analysis significantly reduces the computational cost and provides a unitary framework for the 'forward' simulation and 'inverse' estimation of soft tissues. Moreover, the results suggest that damping in soft-tissue is significant, effectively cancelling the contribution of all but the first few vibration modes.

Space Radiation Program Element Tissue Sharing Forum

NASA Technical Reports Server (NTRS)

Wu, H.; Mayeaux, B M.; Huff, J. L.; Simonsen, L. C.

2016-01-01

Over the years, a large number of animal experiments have been conducted at the NASA Space Radiation Laboratory and other facilities under the support of the NASA Space Radiation Program Element (SRPE). Studies using rodents and other animal species to address the space radiation risks will remain a significant portion of the research portfolio of the Element. In order to maximize scientific return of the animal studies, the SRPE has recently released the Space Radiation Tissue Sharing Forum. The Forum provides access to an inventory of investigator-stored tissue samples and enables both NASA SRPE members and NASA-funded investigators to exchange information regarding stored and future radiobiological tissues available for sharing. Registered users may review online data of available tissues, inquire about tissues posted, or request tissues for an upcoming study using an online form. Investigators who have upcoming sacrifices are also encouraged to post the availability of samples using the discussion forum. A brief demo of the forum will be given during the presentation

The effect of dietary zinc - and polyphenols intake on DMBA-induced mammary tumorigenesis in rats

PubMed Central

2012-01-01

Background The aim of the study was to investigate the effect of dietary supplementation with zinc and polyphenol compounds, i.e. resveratrol and genistein, on the effectiveness of chemically induced mammary cancer and the changes in the content of selected elements (Zn, Cu, Mg, Fe, Ca) in tumors as compared with normal tissue of the mammary gland. Methods Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet and DMBA (7,12-dimethyl-1,2- benz[a]anthracene), were treated with zinc ions (Zn) or zinc ions + resveratrol (Zn + resveratrol) or zinc ions + genistein (Zn + genistein) via gavage for a period from 40 days until 20 weeks of age. The ICP-OES (inductively coupled plasma optical emission spectrometry) technique was used to analyze the following elements: magnesium, iron, zinc and calcium. Copper content in samples was estimated in an atomic absorption spectrophotometer. Results Regardless of the diet (standard; Zn; Zn + resveratrol; Zn + genistein), DMBA-induced breast carcinogenesis was not inhibited. On the contrary, in the Zn + resveratrol supplemented group, tumorigenesis developed at a considerably faster rate. On the basis of quantitative analysis of selected elements we found - irrespectively of the diet applied - great accumulation of copper and iron, which are strongly prooxidative, with a simultaneous considerable decrease of the magnesium content in DMBA-induced mammary tumors. The combination of zinc supplementation with resveratrol resulted in particularly large differences in the amount of the investigated elements in tumors as compared with their content in normal tissue. Conclusions Diet supplementation with zinc and polyphenol compounds, i.e. resveratrol and genistein had no effect on the decreased copper level in tumor tissue and inhibited mammary carcinogenesis in the rat. Irrespectively of the applied diet, the development of the neoplastic process in rats resulted in changes of the iron and magnesium content in the cancerous tissue in comparison with the healthy mammary tissue. The application of combined diet supplementation with zinc ions and resveratrol considerably promoted the rate of carcinogenesis and increased the number of DMBA-induced mammary tumors. PMID:22507225

Transcriptional oscillation of canonical clock genes in mouse peripheral tissues

PubMed Central

Yamamoto, Takuro; Nakahata, Yasukazu; Soma, Haruhiko; Akashi, Makoto; Mamine, Takayoshi; Takumi, Toru

2004-01-01

Background The circadian rhythm of about 24 hours is a fundamental physiological function observed in almost all organisms from prokaryotes to humans. Identification of clock genes has allowed us to study the molecular bases for circadian behaviors and temporal physiological processes such as hormonal secretion, and has prompted the idea that molecular clocks reside not only in a central pacemaker, the suprachiasmatic nuclei (SCN) of hypothalamus in mammals, but also in peripheral tissues, even in immortalized cells. Furthermore, previous molecular dissection revealed that the mechanism of circadian oscillation at a molecular level is based on transcriptional regulation of clock and clock-controlled genes. Results We systematically analyzed the mRNA expression of clock and clock-controlled genes in mouse peripheral tissues. Eight genes (mBmal1, mNpas2, mRev-erbα, mDbp, mRev-erbβ, mPer3, mPer1 and mPer2; given in the temporal order of the rhythm peak) showed robust circadian expressions of mRNAs in all tissues except testis, suggesting that these genes are core molecules of the molecular biological clock. The bioinformatics analysis revealed that these genes have one or a combination of 3 transcriptional elements (RORE, DBPE, and E-box), which are conserved among human, mouse, and rat genome sequences, and indicated that these 3 elements may be responsible for the biological timing of expression of canonical clock genes. Conclusions The observation of oscillatory profiles of canonical clock genes is not only useful for physiological and pathological examination of the circadian clock in various organs but also important for systematic understanding of transcriptional regulation on a genome-wide basis. Our finding of the oscillatory expression of canonical clock genes with a temporal order provides us an interesting hypothesis, that cyclic timing of all clock and clock-controlled genes may be dependent on several transcriptional elements including 3 known elements, E-box, RORE, and DBPE. PMID:15473909

Effects of Different Levels of Molybdenum on Rumen Microbiota and Trace Elements Changes in Tissues from Goats.

PubMed

Zhou, Sihui; Zhang, Caiying; Xiao, Qingyang; Zhuang, Yu; Gu, Xiaolong; Yang, Fan; Xing, Chenghong; Hu, Guoliang; Cao, Huabin

2016-11-01

Molybdenum (Mo) is an essential trace element for animals and human beings. However, the negative effects on rumen function and distribution of trace elements in tissues induced by excessive Mo have not been well understood. Therefore, the purpose of present study was to investigate the impact of Mo on rumen microbiota, distribution of trace elements in various organs, and hematological parameters of goats. A total of 36 goats were randomly distributed into three groups with equal number and low-Mo and high-Mo groups were orally administered ammonium molybdate at 15 and 45 mg · Mo · kg -1  · BW respectively, while the control group received corresponding quantitative deionized water. The results showed that the total number of ciliate and protozoa protein concentration decreased significantly (P < 0.01) on days 25 and 50. Concentrations of ammonia nitrogen and bacterial protein were significantly higher (P < 0.05) in low-Mo group, while they were lower (P < 0.05) in high-Mo group than the control group on days 25 and 50. In addition, Mo accumulated in serum and all detected tissues. Copper (Cu) and zinc (Zn) contents significantly decreased (P < 0.05) in hair and serum on days 25 and 50, while Cu contents increased (P < 0.05) and the change of Zn contents were not obvious (P > 0.05) in other tissues on days 25 and 50. Besides, there was no obvious variation in iron (Fe) contents during whole experiment period (P > 0.05). Furthermore, excessive Mo content had no significant effect on red blood cell (RBC) counts and hemoglobin (HGB) concentration (P > 0.05) on days 25 and 50, while white blood cell (WBC) counts increased significantly (P < 0.05) on day 50. These results indicated that excessive Mo content could impact the balance of ruminal microorganisms and interfere with the absorption and distribution of Mo and Cu mainly.

Will seabass (Dicentrarchus labrax) quality change in a warmer ocean?

PubMed

Barbosa, Vera; Maulvault, Ana Luísa; Alves, Ricardo N; Anacleto, Patrícia; Pousão-Ferreira, Pedro; Carvalho, Maria Luísa; Nunes, Maria Leonor; Rosa, Rui; Marques, António

2017-07-01

The impacts of climate change on seafood quality, safety and human health are still unknown. The present study investigated the effect of warming on fatty acids and elements content in two tissues (muscle and liver) of the relevant commercial seabass species (Dicentrarchus labrax). After exposing fish to increased seawater temperature for a period of 60days, higher saturated fatty acid (SFA) levels were observed in fish muscle (2.16% increase); whereas lower SFA levels were observed in fish liver (5.42% decrease). On the other hand, monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) contents decreased in both muscle (1.77% and 0.39%, respectively) and liver (10.54% and 8.11%, respectively) of fish subjected to warmer conditions. Additionally, warming promoted changes in fish elemental profiles, leading to significantly higher levels of Cl in the muscle and lower levels of Rb in the liver. Overall, data showed that fatty acids and elemental contents were affected by temperature, though representing small implications to human health. Moreover, this preliminary study highlights the importance of conducting further seafood risk-benefit assessments under climate change contexts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue☆

PubMed Central

Pemmer, B.; Roschger, A.; Wastl, A.; Hofstaetter, J.G.; Wobrauschek, P.; Simon, R.; Thaler, H.W.; Roschger, P.; Klaushofer, K.; Streli, C.

2013-01-01

Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radiation induced micro X-ray fluorescence analysis (SR μ-XRF) in combination with quantitative backscattered electron imaging (qBEI) to determine the distribution and accumulation of Zn, Sr, and Pb in human bone tissue. Fourteen human bone samples (10 femoral necks and 4 femoral heads) from individuals with osteoporotic femoral neck fractures as well as from healthy individuals were analyzed. Fluorescence intensity maps were matched with BE images and correlated with calcium (Ca) content. We found that Zn and Pb had significantly increased levels in the cement lines of all samples compared to the surrounding mineralized bone matrix. Pb and Sr levels were found to be correlated with the degree of mineralization. Interestingly, Zn intensities had no correlation with Ca levels. We have shown for the first time that there is a differential accumulation of the trace elements Zn, Pb and Sr in BSUs of human bone indicating different mechanisms of accumulation. PMID:23932972

Trace element contamination in feather and tissue samples from Anna’s hummingbirds

USGS Publications Warehouse

Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

2017-01-01

Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The results from this study provide a benchmark for the distribution of trace element concentrations in feather and tissue samples from hummingbirds and suggests a reference mark for exceeding normal. Lastly, pollinating avian species are minimally represented in the literature as bioindicators for environmental trace element contamination. Given that trace elements can move through food chains by a variety of routes, our study indicates that hummingbirds are possible bioindicators of environmental trace element contamination.

Hematopoietic stem cell origin of connective tissues.

PubMed

Ogawa, Makio; Larue, Amanda C; Watson, Patricia M; Watson, Dennis K

2010-07-01

Connective tissue consists of "connective tissue proper," which is further divided into loose and dense (fibrous) connective tissues and "specialized connective tissues." Specialized connective tissues consist of blood, adipose tissue, cartilage, and bone. In both loose and dense connective tissues, the principal cellular element is fibroblasts. It has been generally believed that all cellular elements of connective tissue, including fibroblasts, adipocytes, chondrocytes, and bone cells, are generated solely by mesenchymal stem cells. Recently, a number of studies, including those from our laboratory based on transplantation of single hematopoietic stem cells, strongly suggested a hematopoietic stem cell origin of these adult mesenchymal tissues. This review summarizes the experimental evidence for this new paradigm and discusses its translational implications. Copyright 2010 ISEH - Society for Hematology and Stem Cells. All rights reserved.

Inorganic elements in green sea turtles (Chelonia mydas): relationships among external and internal tissues

USGS Publications Warehouse

Faust, Derek R.; Hooper, Michael J.; Cobb, George P.; Barnes, Melanie; Shaver, Donna; Ertolacci, Shauna; Smith, Philip N.

2014-01-01

Inorganic elements from anthropogenic sources have entered marine environments worldwide and are detectable in marine organisms, including sea turtles. Threatened and endangered classifications of sea turtles have heretofore made assessments of contaminant concentrations difficult because of regulatory restrictions on obtaining samples using nonlethal techniques. In the present study, claw and skin biopsy samples were examined as potential indicators of internal tissue burdens in green sea turtles (Chelonia mydas). Significant relationships were observed between claw and liver, and claw and muscle concentrations of mercury, nickel, arsenic, and selenium (p < 0.05). Similarly, significant relationships were observed between skin biopsy concentrations and those in liver, kidney, and muscle tissues for mercury, arsenic, selenium, and vanadium (p < 0.05). Concentrations of arsenic, barium, chromium, nickel, strontium, vanadium, and zinc in claws and skin biopsies were substantially elevated when compared with all other tissues, indicating that these highly keratinized tissues may represent sequestration or excretion pathways. Correlations between standard carapace length and cobalt, lead, and manganese concentrations were observed (p < 0.05), indicating that tissue concentrations of these elements may be related to age and size. Results suggest that claws may indeed be useful indicators of mercury and nickel concentrations in liver and muscle tissues, whereas skin biopsy inorganic element concentrations may be better suited as indicators of mercury, selenium, and vanadium concentrations in liver, kidney, and muscle tissues of green sea turtles.

Precipitation of calcium, magnesium, strontium and barium in tissues of four Acacia species (Leguminosae: Mimosoideae).

PubMed

He, Honghua; Bleby, Timothy M; Veneklaas, Erik J; Lambers, Hans; Kuo, John

2012-01-01

Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory.

Precipitation of Calcium, Magnesium, Strontium and Barium in Tissues of Four Acacia Species (Leguminosae: Mimosoideae)

PubMed Central

He, Honghua; Bleby, Timothy M.; Veneklaas, Erik J.; Lambers, Hans; Kuo, John

2012-01-01

Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory. PMID:22848528

Influence of tissue resistivities on neuromagnetic fields and electric potentials studied with a finite element model of the head.

PubMed

Haueisen, J; Ramon, C; Eiselt, M; Brauer, H; Nowak, H

1997-08-01

Modeling in magnetoencephalography (MEG) and electroencephalography (EEG) requires knowledge of the in vivo tissue resistivities of the head. The aim of this paper is to examine the influence of tissue resistivity changes on the neuromagnetic field and the electric scalp potential. A high-resolution finite element method (FEM) model (452,162 elements, 2-mm resolution) of the human head with 13 different tissue types is employed for this purpose. Our main finding was that the magnetic fields are sensitive to changes in the tissue resistivity in the vicinity of the source. In comparison, the electric surface potentials are sensitive to changes in the tissue resistivity in the vicinity of the source and in the vicinity of the position of the electrodes. The magnitude (strength) of magnetic fields and electric surface potentials is strongly influenced by tissue resistivity changes, while the topography is not as strongly influenced. Therefore, an accurate modeling of magnetic field and electric potential strength requires accurate knowledge of tissue resistivities, while for source localization procedures this knowledge might not be a necessity.

Thymidine kinase 2 deficiency-induced mitochondrial DNA depletion causes abnormal development of adipose tissues and adipokine levels in mice.

PubMed

Villarroya, Joan; Dorado, Beatriz; Vilà, Maya R; Garcia-Arumí, Elena; Domingo, Pere; Giralt, Marta; Hirano, Michio; Villarroya, Francesc

2011-01-01

Mammal adipose tissues require mitochondrial activity for proper development and differentiation. The components of the mitochondrial respiratory chain/oxidative phosphorylation system (OXPHOS) are encoded by both mitochondrial and nuclear genomes. The maintenance of mitochondrial DNA (mtDNA) is a key element for a functional mitochondrial oxidative activity in mammalian cells. To ascertain the role of mtDNA levels in adipose tissue, we have analyzed the alterations in white (WAT) and brown (BAT) adipose tissues in thymidine kinase 2 (Tk2) H126N knockin mice, a model of TK2 deficiency-induced mtDNA depletion. We observed respectively severe and moderate mtDNA depletion in TK2-deficient BAT and WAT, showing both tissues moderate hypotrophy and reduced fat accumulation. Electron microscopy revealed altered mitochondrial morphology in brown but not in white adipocytes from TK2-deficient mice. Although significant reduction in mtDNA-encoded transcripts was observed both in WAT and BAT, protein levels from distinct OXPHOS complexes were significantly reduced only in TK2-deficient BAT. Accordingly, the activity of cytochrome c oxidase was significantly lowered only in BAT from TK2-deficient mice. The analysis of transcripts encoding up to fourteen components of specific adipose tissue functions revealed that, in both TK2-deficient WAT and BAT, there was a consistent reduction of thermogenesis related gene expression and a severe reduction in leptin mRNA. Reduced levels of resistin mRNA were found in BAT from TK2-deficient mice. Analysis of serum indicated a dramatic reduction in circulating levels of leptin and resistin. In summary, our present study establishes that mtDNA depletion leads to a moderate impairment in mitochondrial respiratory function, especially in BAT, causes substantial alterations in WAT and BAT development, and has a profound impact in the endocrine properties of adipose tissues. © 2011 Villarroya et al.

Thymidine Kinase 2 Deficiency-Induced Mitochondrial DNA Depletion Causes Abnormal Development of Adipose Tissues and Adipokine Levels in Mice

PubMed Central

Villarroya, Joan; Dorado, Beatriz; Vilà, Maya R.; Garcia-Arumí, Elena; Domingo, Pere; Giralt, Marta; Hirano, Michio; Villarroya, Francesc

2011-01-01

Mammal adipose tissues require mitochondrial activity for proper development and differentiation. The components of the mitochondrial respiratory chain/oxidative phosphorylation system (OXPHOS) are encoded by both mitochondrial and nuclear genomes. The maintenance of mitochondrial DNA (mtDNA) is a key element for a functional mitochondrial oxidative activity in mammalian cells. To ascertain the role of mtDNA levels in adipose tissue, we have analyzed the alterations in white (WAT) and brown (BAT) adipose tissues in thymidine kinase 2 (Tk2) H126N knockin mice, a model of TK2 deficiency-induced mtDNA depletion. We observed respectively severe and moderate mtDNA depletion in TK2-deficient BAT and WAT, showing both tissues moderate hypotrophy and reduced fat accumulation. Electron microscopy revealed altered mitochondrial morphology in brown but not in white adipocytes from TK2-deficient mice. Although significant reduction in mtDNA-encoded transcripts was observed both in WAT and BAT, protein levels from distinct OXPHOS complexes were significantly reduced only in TK2-deficient BAT. Accordingly, the activity of cytochrome c oxidase was significantly lowered only in BAT from TK2-deficient mice. The analysis of transcripts encoding up to fourteen components of specific adipose tissue functions revealed that, in both TK2-deficient WAT and BAT, there was a consistent reduction of thermogenesis related gene expression and a severe reduction in leptin mRNA. Reduced levels of resistin mRNA were found in BAT from TK2-deficient mice. Analysis of serum indicated a dramatic reduction in circulating levels of leptin and resistin. In summary, our present study establishes that mtDNA depletion leads to a moderate impairment in mitochondrial respiratory function, especially in BAT, causes substantial alterations in WAT and BAT development, and has a profound impact in the endocrine properties of adipose tissues. PMID:22216345

Breast Cancer Research at NASA

NASA Technical Reports Server (NTRS)

1998-01-01

Isolation of human mammary epithelial cells (HMEC) from breast cancer susceptible tissue; A: Duct element recovered from breast tissue digest. B: Outgrowth of cells from duct element in upper right corner cultured in a standard dish; most cells spontaneousely die during early cell divisions, but a few will establish long-term growth. C: Isolate of long-term frowth HMEC from outgrowth of duct element; cells shown soon after isolation and in early full-cell contact growth in culture in a dish. D: same long-term growth HMEC, but after 3 weeks in late full-cell contact growth in a continuous culture in a dish. Note attempts to reform duct elements but this in two demensions in a dish rather than in three dimensions in tissue. NASA's Marshall Space Flight Center (MSFC) is sponsoring research with Bioreactors, rotating wall vessels designed to grow tissue samples in space, to understand how breast cancer works. This ground-based work studies the growth and assembly of human mammary epithelial cell (HMEC) from breast cancer susceptible tissue. Radiation can make the cells cancerous, thus allowing better comparisons of healthy vs. tunorous tissue. Credit: Dr. Robert Richmond, NASA/Marshall Space Flight Center (MSFC).

An Inducible DamID System for Profiling Interactions of Nuclear Lamina Protein Component Lamin B1 with Chromosomes in Mouse Cells.

PubMed

Kozhevnikova, E N; Leshchenko, A E; Pindyurin, A V

2018-05-01

At the level of DNA organization into chromatin, there are mechanisms that define gene expression profiles in specialized cell types. Genes within chromatin regions that are located at the nuclear periphery are generally expressed at lower levels; however, the nature of this phenomenon remains unclear. These parts of chromatin interact with nuclear lamina proteins like Lamin B1 and, therefore, can be identified in a given cell type by chromatin profiling of these proteins. In this study, we created and tested a Dam Identification (DamID) system induced by Cre recombinase using Lamin B1 and mouse embryonic fibroblasts. This inducible system will help to generate genome-wide profiles of chromatin proteins in given cell types and tissues with no need to dissect tissues from organs or separate cells from tissues, which is achieved by using specific regulatory DNA elements and due to the high sensitivity of the method.

Experimental and Computational Investigation of Viscoelasticity of Native and Engineered Ligament and Tendon

NASA Astrophysics Data System (ADS)

Ma, J.; Narayanan, H.; Garikipati, K.; Grosh, K.; Arruda, E. M.

The important mechanisms by which soft collagenous tissues such as ligament and tendon respond to mechanical deformation include non-linear elasticity, viscoelasticity and poroelasticity. These contributions to the mechanical response are modulated by the content and morphology of structural proteins such as type I collagen and elastin, other molecules such as glycosaminoglycans, and fluid. Our ligament and tendon constructs, engineered from either primary cells or bone marrow stromal cells and their autogenous matricies, exhibit histological and mechanical characteristics of native tissues of different levels of maturity. In order to establish whether the constructs have optimal mechanical function for implantation and utility for regenerative medicine, constitutive relationships for the constructs and native tissues at different developmental levels must be established. A micromechanical model incorporating viscoelastic collagen and non-linear elastic elastin is used to describe the non-linear viscoelastic response of our homogeneous engineered constructs in vitro. This model is incorporated within a finite element framework to examine the heterogeneity of the mechanical responses of native ligament and tendon.

Modeling of the interaction between grip force and vibration transmissibility of a finger.

PubMed

Wu, John Z; Welcome, Daniel E; McDowell, Thomas W; Xu, Xueyan S; Dong, Ren G

2017-07-01

It is known that the vibration characteristics of the fingers and hand and the level of grip action interacts when operating a power tool. In the current study, we developed a hybrid finger model to simulate the vibrations of the hand-finger system when gripping a vibrating handle covered with soft materials. The hybrid finger model combines the characteristics of conventional finite element (FE) models, multi-body musculoskeletal models, and lumped mass models. The distal, middle, and proximal finger segments were constructed using FE models, the finger segments were connected via three flexible joint linkages (i.e., distal interphalangeal joint (DIP), proximal interphalangeal joint (PIP), and metacarpophalangeal (MCP) joint), and the MCP joint was connected to the ground and handle via lumped parameter elements. The effects of the active muscle forces were accounted for via the joint moments. The bone, nail, and hard connective tissues were assumed to be linearly elastic whereas the soft tissues, which include the skin and subcutaneous tissues, were considered as hyperelastic and viscoelastic. The general trends of the model predictions agree well with the previous experimental measurements in that the resonant frequency increased from proximal to the middle and to the distal finger segments for the same grip force, that the resonant frequency tends to increase with increasing grip force for the same finger segment, especially for the distal segment, and that the magnitude of vibration transmissibility tends to increase with increasing grip force, especially for the proximal segment. The advantage of the proposed model over the traditional vibration models is that it can predict the local vibration behavior of the finger to a tissue level, while taking into account the effects of the active musculoskeletal force, the effects of the contact conditions on vibrations, the global vibration characteristics. Published by Elsevier Ltd.

Measurement and Finite Element Model Validation of Immature Porcine Brain-Skull Displacement during Rapid Sagittal Head Rotations.

PubMed

Pasquesi, Stephanie A; Margulies, Susan S

2018-01-01

Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain-skull displacement in the neonatal piglet head ( n  = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain-skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain-skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain-skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain-skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations.

Measurement and Finite Element Model Validation of Immature Porcine Brain–Skull Displacement during Rapid Sagittal Head Rotations

PubMed Central

Pasquesi, Stephanie A.; Margulies, Susan S.

2018-01-01

Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain–skull displacement in the neonatal piglet head (n = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain–skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain–skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain–skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain–skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations. PMID:29515995

Transcriptional regulatory elements in the noncoding region of human papillomavirus type 6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Tzyy-Choou.

1989-01-01

The structure and function of the transcriptional regulatory region of human papillomavirus type 6 (HPV-6) has been investigated. To investigate tissue specific gene expression, a sensitive method to detect and localize HPV-6 viral DNA, mRNA and protein in plastic-embedded tissue sections of genital and respiratory tract papillomata by using in situ hybridization and immunoperoxidase assays has been developed. This method, using ultrathin sections and strand-specific {sup 3}H labeled riboprobes, offers the advantages of superior morphological preservation and detection of viral genomes at low copy number with good resolution, and the modified immunocytochemistry provides better sensitivity. The results suggest that genitalmore » tract epithelium is more permissive for HPV-6 replication than respiratory tract epithelium. To study the tissue tropism of HPV-6 at the level of regulation of viral gene expression, the polymerase chain reaction was used to isolate the noncoding region (NCR) of HPV-6 in independent isolates. Nucleotide sequence analysis of molecularly cloned DNA identified base substitutions, deletions/insertions and tandem duplications. Transcriptional regulatory elements in the NCR were assayed in recombinant plasmids containing the bacterial gene for chloramphenicol acetyl transferase.« less

Application of an asymmetric finite element model of the C2-T1 cervical spine for evaluating the role of soft tissues in stability.

PubMed

Erbulut, D U; Zafarparandeh, I; Lazoglu, I; Ozer, A F

2014-07-01

Different finite element models of the cervical spine have been suggested for evaluating the roles of ligaments, facet joints, and disks in the stability of cervical spine under sagittal moments. However, no comprehensive study on the response of the full cervical spine that has used a detailed finite element (FE) model (C2-T1) that considers the asymmetry about the mid-sagittal plane has been reported. The aims of this study were to consider asymmetry in a FE model of the full cervical spine and to investigate the influences of ligaments, facet joints, and disk nucleus on the stability of the asymmetric model during flexion and extension. The model was validated against various published in vitro studies and FE studies for the three main loading planes. Next, the C4-C5 level was modified to simulate different cases to investigate the role of the soft tissues in segmental stability. The FE model predicted that excluding the interspinous ligament (ISL) from the index level would cause excessive instability during flexion and that excluding the posterior longitudinal ligament (PLL) or the ligamentum flavum (LF) would not affect segmental rotation. During extension, motion increased when the facet joints were excluded. The model without disk nucleus was unstable compared to the intact model at lower loads and exhibited a similar rotation response at higher loads. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Trace elements bioaccumulation in liver and fur of Myotis myotis from two caves of the eastern side of Sicily (Italy): A comparison between a control and a polluted area.

PubMed

Ferrante, Margherita; Spena, Maria Teresa; Hernout, Béatrice Veronique; Grasso, Alfina; Messina, Andrea; Grasso, Rosario; Agnelli, Paolo; Brundo, Maria Violetta; Copat, Chiara

2018-05-07

Environmental pollution is a topic of great interest because it directly affects the quality of ecosystems and of all living organisms at different trophic and systematic levels. Together with the global climate change, the long-term surviving of many species of plants and animals is threaten, distributional patterns at global and regional levels are altered and it results in local assemblages of species that are quite different from those that currently constitute coevolved communities. .For this study, the species Myotis myotis was used as bioindicator and it was sampled from two caves in the south-east of Sicily, Pipistrelli chosen as control area and Palombara chosen as polluted area, to measure the concentrations of trace elements in fur and liver tissues. Results showed higher content of essential elements in fur in bats sampled from Pipistrelli. Conversely, higher concentrations of toxic metals in liver such as As, Cd, Pb and Hg were measured in bat samples in Palombara cave, where specimens have a hunting area extended within the boundaries of the petrochemical plant. Nevertheless, we cannot consider Palombara population as polluted by metal contamination since their tissue concentrations are overall lower than toxic thresholds values suggested for small mammals. Likewise, we cannot exclude other kind of pollutants as potential stressors of the examined population, contributing with the decreasing of bat colonies in Sicily. Copyright © 2018 Elsevier Ltd. All rights reserved.

Classification of trace elements in tissues from organic and conventional French pig production.

PubMed

Parinet, Julien; Royer, Eric; Saint-Hilaire, Mailie; Chafey, Claude; Noël, Laurent; Minvielle, Brice; Dervilly-Pinel, Gaud; Engel, Erwan; Guérin, Thierry

2018-07-01

This study assesses the impact of the farming system on the levels of copper, zinc, arsenic, cadmium, lead and mercury in pig tissues from three types of production (Organic (n = 28), Label Rouge (n = 12) and Conventional (n = 30)) randomly sampled in different slaughterhouses. All the concentrations were below regulatory limits. In muscles, Cu, Zn and As were measured at slightly higher levels in organic samples but no differences between organic and Label Rouge was observed. Livers from conventional and Label Rouge pig farms exhibited higher Zn and Cd contents than the organic ones, probably due to different practice in zinc or phytase supplementation of fattening diets. Principal component analysis indicated a correlation between Cu and As concentrations in liver and carcass weight, and between Zn and Cd liver levels and lean meat percentage. The linear discriminant analysis succeeded in predicting the farming process on the basis of the lean meat percentage and the liver Cd level. Copyright © 2018 Elsevier Ltd. All rights reserved.

Metal and transuranic records in mussel shells, byssal threads and tissues

NASA Astrophysics Data System (ADS)

Koide, Minoru; Lee, Dong Soo; Goldberg, Edward D.

1982-12-01

Bivalve shells offer several advantages over tissues for the monitoring of heavy metal pollutants in the marine environment. They are easier to handle and to store. The problem of whether to depurate the animals before analyses is avoided. The shells appear to be more sensitive to environmental heavy metals levels over the long term than do the soft parts. Of the substances examined (Cd, Cu, Zn, Pb, Ag, Ni, 238Pu and 239 + 240Pu) only Pb and Pu displayed a strong covariance between soft tissue and shell concentrations. There were strong correlations between metals in the shell but not in the soft tissues in general. The byssal threads, because of their enrichment of transuranic elements and of their ease in handling, may be useful in monitoring these metals. A very weak discharge of 238Pu to marine waters adjacent to a nuclear reactor was detected in the byssal threads of mussels.

SR-TXRF analysis of trace elements in whole blood and heart of rats: effects of irradiation with low and high doses

NASA Astrophysics Data System (ADS)

Mota, C. L.; Pickler, A.; Braz, D.; Barroso, R. C.; Mantuano, A.; Salata, C.; Ferreira-Machado, S. C.; Lau, C. C.; de Almeida, C. E.

2018-04-01

In the last decades, studies showed that the exposure to low doses of ionizing radiation of the body could sense and activate the cell signaling pathways needed to respond to any induced cellular damage. This procedure reduces cell killing compared with a single dose of high radiation dose. Damage to the vasculature can affect the function of most body organs by restricting blood flow and oxygen to tissues; however, the heart and brain are of main concern. The precise relationship between long-term health effects and low-dose exposures remain poorly understood. Biological markers are powerful tools that can be used to determine dose- response relationships and to estimate risk, especially when dealing with, the effects of low dose exposures in humans. These markers should be specific, sensitive, as well as easy and fast to quantify. Various types of biologic specimens are potential candidates for identifying biomarkers but blood has the advantage of being minimally invasive to obtain. In this study, we propose to apply total reflection X-ray fluorescence to quantify possible chemical elemental concentration (sulfer, iron, zinc, potassium and calcium) changes in blood and heart tissues of Wistar rats after total body irradiation with low (0.1 Gy) and high (2.5 Gy) doses. The fluorescence measurements were carried out at the X-ray Fluorescence beamline in the Brazilian Synchrotron Light Laboratory. The results showed that the irradiated animals with low doses have significant alterations in blood and cardiac tissue when compared with animals that received high doses of radiation. Taken together the analysis of all the elements, we can observe that the radiation induced oxidative stress may be the leading cause for alteration of the elemental level in the studied samples.

Glucocorticoids Affect 24 h Clock Genes Expression in Human Adipose Tissue Explant Cultures

PubMed Central

Gómez-Abellán, Purificación; Díez-Noguera, Antoni; Madrid, Juan A.; Luján, Juan A.; Ordovás, José M.; Garaulet, Marta

2012-01-01

Aims to examine firstly whether CLOCK exhibits a circadian expression in human visceral (V) and subcutaneous (S) adipose tissue (AT) in vitro as compared with BMAL1 and PER2, and secondly to investigate the possible effect of the glucocorticoid analogue dexamethasone (DEX) on positive and negative clock genes expression. Subjects and Methods VAT and SAT biopsies were obtained from morbid obese women (body mass index≥40 kg/m2) (n = 6). In order to investigate rhythmic expression pattern of clock genes and the effect of DEX on CLOCK, PER2 and BMAL1 expression, control AT (without DEX) and AT explants treated with DEX (2 hours) were cultured during 24 h and gene expression was analyzed at the following times: 10:00 h, 14:00 h, 18:00 h, 22:00 h, 02:00 h and 06:00 h, using qRT-PCR. Results CLOCK, BMAL1 and PER2 expression exhibited circadian patterns in both VAT and SAT explants that were adjusted to a typical 24 h sinusoidal curve. PER2 expression (negative element) was in antiphase with respect to CLOCK and in phase with BMAL1 expression (both positive elements) in the SAT (situation not present in VAT). A marked effect of DEX exposure on both positive and negative clock genes expression patterns was observed. Indeed, DEX treatment modified the rhythmicity pattern towards altered patterns with a period lower than 24 hours in all genes and in both tissues. Conclusions 24 h patterns in CLOCK and BMAL1 (positive clock elements) and PER2 (negative element) mRNA levels were observed in human adipose explants. These patterns were altered by dexamethasone exposure. PMID:23251369

Three new mussel tissue standard reference materials (SRMs) for the determination of organic contaminants.

PubMed

Poster, Dianne L; Schantz, Michele M; Kucklick, John R; Lopez de Alda, Maria J; Porter, Barbara J; Pugh, Rebecca; Wise, Stephen A

2004-03-01

Three new mussel tissue standard reference materials (SRMs) have been developed by the National Institute of Standards and Technology (NIST) for the determination of the concentrations of organic contaminants. The most recently prepared material, SRM 1974b, is a fresh frozen tissue homogenate prepared from mussels ( Mytilus edulis) collected in Boston Harbor, Massachusetts. The other two materials, SRMs 2977 and 2978, are freeze-dried tissue homogenates prepared from mussels collected in Guanabara Bay, Brazil and Raritan Bay, New Jersey, respectively. All three new mussel tissue SRMs complement the current suite of marine natural-matrix SRMs available from NIST that are characterized for a wide range of contaminants (organic and inorganic). SRM 1974b has been developed to replace its predecessor SRM 1974a, Organics in Mussel Tissue, for which the supply is depleted. Similarly, SRMs 2977 and 2978 were developed to replace a previously available (supply depleted) freeze-dried version of SRM 1974a, SRM 2974, Organics in Freeze-Dried Mussel Tissue. SRM 1974b is the third in a series of fresh frozen mussel tissue homogenate SRMs prepared from mussels collected in Boston Harbor starting in 1988. SRM 1974b has certified concentration values for 22 polycyclic aromatic hydrocarbons (PAHs), 31 polychlorinated biphenyl congeners (PCBs), and 7 chlorinated pesticides. Reference values are provided for additional constituents: 16 PAHs, 8 PCBs plus total PCBs, 6 pesticides, total extractable organics, methylmercury, and 11 trace elements. PAH concentrations range from about 2 ng g(-1 )dry mass (cyclopenta[ cd]pyrene) to 180 ng g(-1 )dry mass (pyrene). PCB concentrations range from about 2 ng g(-1 )dry mass (PCB 157) to 120 ng g(-1 )dry mass (PCB 153). The reference value for total PCBs in SRM 1974b is (2020 +/- 420) ng g(-1 )dry mass. Pesticide concentrations range from about 4 ng g(-1 )dry mass (4,4'-DDT) to 40 ng g(-1 )dry mass (4,4'-DDE). SRM 2977 has certified values for 14 PAHs, 25 PCB congeners, 7 pesticides, 6 trace elements, and methylmercury. Reference values for 16 additional PAHs and 9 inorganic constituents are provided, and information values are given for 23 additional trace elements. SRM 2978 has certified and reference concentrations for 41 and 22 organic compounds, respectively, and contains contaminant levels similar to those of SRM 1974b. Organic contaminant levels in SRM 2977 (mussels from Guanabara Bay, Brazil) are typically a factor of 2 to 4 lower than those in SRM 1974b and SRM 2978. The organic contaminant concentrations in each new mussel tissue SRM are presented and compared in this paper. In addition, a chronological review of contaminant concentrations associated with mussels collected in Boston Harbor is discussed as well as a stability assessment of SRM 1974a.

Coupled porohyperelastic mass transport (PHEXPT) finite element models for soft tissues using ABAQUS.

PubMed

Vande Geest, Jonathan P; Simon, B R; Rigby, Paul H; Newberg, Tyler P

2011-04-01

Finite element models (FEMs) including characteristic large deformations in highly nonlinear materials (hyperelasticity and coupled diffusive/convective transport of neutral mobile species) will allow quantitative study of in vivo tissues. Such FEMs will provide basic understanding of normal and pathological tissue responses and lead to optimization of local drug delivery strategies. We present a coupled porohyperelastic mass transport (PHEXPT) finite element approach developed using a commercially available ABAQUS finite element software. The PHEXPT transient simulations are based on sequential solution of the porohyperelastic (PHE) and mass transport (XPT) problems where an Eulerian PHE FEM is coupled to a Lagrangian XPT FEM using a custom-written FORTRAN program. The PHEXPT theoretical background is derived in the context of porous media transport theory and extended to ABAQUS finite element formulations. The essential assumptions needed in order to use ABAQUS are clearly identified in the derivation. Representative benchmark finite element simulations are provided along with analytical solutions (when appropriate). These simulations demonstrate the differences in transient and steady state responses including finite deformations, total stress, fluid pressure, relative fluid, and mobile species flux. A detailed description of important model considerations (e.g., material property functions and jump discontinuities at material interfaces) is also presented in the context of finite deformations. The ABAQUS-based PHEXPT approach enables the use of the available ABAQUS capabilities (interactive FEM mesh generation, finite element libraries, nonlinear material laws, pre- and postprocessing, etc.). PHEXPT FEMs can be used to simulate the transport of a relatively large neutral species (negligible osmotic fluid flux) in highly deformable hydrated soft tissues and tissue-engineered materials.

Parameters and computer software for the evaluation of mass attenuation and mass energy-absorption coefficients for body tissues and substitutes.

PubMed

Okunade, Akintunde A

2007-07-01

The mass attenuation and energy-absorption coefficients (radiation interaction data), which are widely used in the shielding and dosimetry of X-rays used for medical diagnostic and orthovoltage therapeutic procedures, are strongly dependent on the energy of photons, elements and percentage by weight of elements in body tissues and substitutes. Significant disparities exist in the values of percentage by weight of elements reported in literature for body tissues and substitutes for individuals of different ages, genders and states of health. Often, interested parties are in need of these radiation interaction data for body tissues or substitutes with percentage by weight of elements and intermediate energies that are not tabulated in literature. To provide for the use of more precise values of these radiation interaction data, parameters and computer programs, MUA_T and MUEN_T are presented for the computation of mass attenuation and energy-absorption coefficients for body tissues and substitutes of arbitrary percentage-by-weight elemental composition and photon energy ranging between 1 keV (or k-edge) and 400 keV. Results are presented, which show that the values of mass attenuation and energy-absorption coefficients obtained from computer programs are in good agreement with those reported in literature.

Deciphering the Role of CBF/DREB Transcription Factors and Dehydrins in Maintaining the Quality of Table Grapes cv. Autumn Royal Treated with High CO2 Levels and Stored at 0°C

PubMed Central

Vazquez-Hernandez, Maria; Romero, Irene; Escribano, M. I.; Merodio, Carmen; Sanchez-Ballesta, M. T.

2017-01-01

C-repeat/dehydration-responsive element binding factors (CBF/DREB) are transcription factors which play a role in improving plant cold stress resistance and recognize the DRE/CRT element in the promoter of a set of cold regulated genes. Dehydrins (DHNs) are proteins that accumulate in plants in response to cold stress, which present, in some cases, CBF/DREB recognition sequences in their promoters and are activated by members of this transcription factor family. The application of a 3-day gaseous treatment with 20 kPa CO2 at 0°C to table grapes cv. Autumn Royal maintained the quality of the bunches during postharvest storage at 0°C, reducing weight loss and rachis browning. In order to determine the role of CBF/DREB genes in the beneficial effect of the gaseous treatment by regulating DHNs, we have analyzed the gene expression pattern of three VviDREBA1s (VviDREBA1-1, VviDREBA1-6, and VviDREBA1-7) as well as three VviDHNs (VviDHN1a, VviDHN2, and VviDHN4), in both alternative splicing forms. Results showed that the differences in VviDREBA1s expression were tissue and atmosphere composition dependent, although the application of high levels of CO2 caused a greater increase of VviDREBA1-1 in the skin, VviDREBA1-6 in the pulp and VviDREBA1-7 in the skin and pulp. Likewise, the application of high levels of CO2 regulated the retention of introns in the transcripts of the dehydrins studied in the different tissues analyzed. The DHNs promoter analysis showed that VviDHN2 presented the cis-acting DRE and CRT elements, whereas VviDHN1a presented only the DRE motif. Our electrophoretic mobility shift assays (EMSA) showed that VviDREBA1-1 was the only transcription factor that had in vitro binding capacity to the CRT element of the VviDHN2 promoter region, indicating that the transcriptional regulation of VviDHN1a and VviDHN4 would be carried out by activating other independent routes of these transcription factors. Our results suggest that the application of high CO2 levels to maintain table grape quality during storage at 0°C, leads to an activation of CBF/DREBs transcription factors. Among these factors, VviDREBA1-1 seems to participate in the transcriptional activation of VviDHN2 via CRT binding, with the unspliced form of this DHN being activated by high CO2 levels in all the tissues analyzed. PMID:28970842

Involvement of glucocorticoid prereceptor metabolism and signaling in rat visceral adipose tissue lipid metabolism after chronic stress combined with high-fructose diet.

PubMed

Bursać, Biljana; Djordjevic, Ana; Veličković, Nataša; Milutinović, Danijela Vojnović; Petrović, Snježana; Teofilović, Ana; Gligorovska, Ljupka; Preitner, Frederic; Tappy, Luc; Matić, Gordana

2018-05-03

Both fructose overconsumption and increased glucocorticoids secondary to chronic stress may contribute to overall dyslipidemia. In this study we specifically assessed the effects and interactions of dietary fructose and chronic stress on lipid metabolism in the visceral adipose tissue (VAT) of male Wistar rats. We analyzed the effects of 9-week 20% high fructose diet and 4-week chronic unpredictable stress, separately and in combination, on VAT histology, glucocorticoid prereceptor metabolism, glucocorticoid receptor subcellular redistribution and expression of major metabolic genes. Blood triglycerides and fatty acid composition were also measured to assess hepatic Δ9 desaturase activity. The results showed that fructose diet increased blood triglycerides and Δ9 desaturase activity. On the other hand, stress led to corticosterone elevation, glucocorticoid receptor activation and decrease in adipocyte size, while phosphoenolpyruvate carboxykinase, adipose tissue triglyceride lipase, FAT/CD36 and sterol regulatory element binding protein-1c (SREBP-1c) were increased, pointing to VAT lipolysis and glyceroneogenesis. The combination of stress and fructose diet was associated with marked stimulation of fatty acid synthase and acetyl-CoA carboxylase mRNA level and with increased 11β-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase protein levels, suggesting a coordinated increase in hexose monophosphate shunt and de novo lipogenesis. It however did not influence the level of peroxisome proliferator-activated receptor-gamma, SREBP-1c and carbohydrate responsive element-binding protein. In conclusion, our results showed that only combination of dietary fructose and stress increase glucocorticoid prereceptor metabolism and stimulates lipogenic enzyme expression suggesting that interaction between stress and fructose may be instrumental in promoting VAT expansion and dysfunction. Copyright © 2018 Elsevier B.V. All rights reserved.

Trace element analysis by PIXE in several biomedical fields

NASA Astrophysics Data System (ADS)

Weber, G.; Robaye, G.; Bartsch, P.; Collignon, A.; Beguin, Y.; Roelandts, I.; Delbrouck, J. M.

1984-04-01

Since 1980 in the University of Liége trace element analysis by PIXE has been developed in several directions, among these: the elemental composition of lung parenchyma, hilar lymph nodes, blood content in hematological disorders and renal insufficiency. The content in trace elements of lung tumor and surrounding tissue is measured and compared to similar content previously obtained on unselected patients of comparable ages. The normalization of the bromine deficiency observed in hemodialized patients is achieved by using a dialyzing bath doped with NaBr in order to obtain a normal bromine level of 5.7 μg/ml. The content of Cu, Zn, Br and Se in blood serum from more than 100 patients suffering from malignant hemopathy has been measured. The results are compared with a reference group. These oligoelements have also been measured sequentially for patients under intensive chemotherapy in acute myeloid leukemia.

Reference Models for Multi-Layer Tissue Structures

DTIC Science & Technology

2016-09-01

simulation,  finite   element  analysis 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC...Physiologically realistic, fully specimen-specific, nonlinear reference models. Tasks. Finite element analysis of non-linear mechanics of cadaver...models. Tasks. Finite element analysis of non-linear mechanics of multi-layer tissue regions of human subjects. Deliverables. Partially subject- and

Imaging of glial cell morphology, SOD1 distribution and elemental composition in the brainstem and hippocampus of the ALS hSOD1G93A rat.

PubMed

Stamenković, Stefan; Dučić, Tanja; Stamenković, Vera; Kranz, Alexander; Andjus, Pavle R

2017-08-15

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting motor and cognitive domains of the CNS. Mutations in the Cu,Zn-superoxide dismutase (SOD1) cause 20% of familial ALS and provoke formation of intracellular aggregates and copper and zinc unbinding, leading to glial activation and neurodegeneration. Therefore, we investigated glial cell morphology, intracellular SOD1 distribution, and elemental composition in the brainstem and hippocampus of the hSOD1 G93A transgenic rat model of ALS. Immunostaining for astrocytes, microglia and SOD1 revealed glial proliferation and progressive tissue accumulation of SOD1 in both brain regions of ALS rats starting already at the presymptomatic stage. Glial cell morphology analysis in the brainstem of ALS rats revealed astrocyte activation occurring before disease symptoms onset, followed by activation of microglia. Hippocampal ALS astrocytes exhibited an identical reactive profile, while microglial morphology was unchanged. Additionally, ALS brainstem astrocytes demonstrated progressive SOD1 accumulation in the cell body and processes, while microglial SOD1 levels were reduced and its distribution limited to distal cell processes. In the hippocampus both glial cell types exhibited SOD1 accumulation in the cell body. X-ray fluorescence imaging revealed decreased P and increased Ca, Cl, K, Ni, Cu and Zn in the brainstem, and higher levels of Cl, Ni and Cu, but lower levels of Zn in the hippocampus of symptomatic ALS rats. These results bring new insights into the glial response during disease development and progression in motor as well as in non-motor CNS structures, and indicate disturbed tissue elemental homeostasis as a prominent hallmark of disease pathology. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

An approach for quantification of platinum distribution in tissues by LA-ICP-MS imaging using isotope dilution analysis.

PubMed

Moraleja, I; Mena, M L; Lázaro, A; Neumann, B; Tejedor, A; Jakubowski, N; Gómez-Gómez, M M; Esteban-Fernández, D

2018-02-01

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been revealed as a convenient technique for trace elemental imaging in tissue sections, providing elemental 2D distribution at a quantitative level. For quantification purposes, in the last years several approaches have been proposed in the literature such as the use of CRMs or matrix matched standards. The use of Isotope Dilution (ID) for quantification by LA-ICP-MS has been also described, being mainly useful for bulk analysis but not feasible for spatial measurements so far. In this work, a quantification method based on ID analysis was developed by printing isotope-enriched inks onto kidney slices from rats treated with antitumoral Pt-based drugs using a commercial ink-jet device, in order to perform an elemental quantification in different areas from bio-images. For the ID experiments 194 Pt enriched platinum was used. The methodology was validated by deposition of natural Pt standard droplets with a known amount of Pt onto the surface of a control tissue, where could be quantified even 50pg of Pt, with recoveries higher than 90%. The amount of Pt present in the whole kidney slices was quantified for cisplatin, carboplatin and oxaliplatin-treated rats. The results obtained were in accordance with those previously reported. The amount of Pt distributed between the medullar and cortical areas was also quantified, observing different behavior for the three drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of a combination of continuum and truss finite elements in a model of passive and active muscle tissue.

PubMed

Hedenstierna, S; Halldin, P; Brolin, K

2008-12-01

The numerical method of finite elements (FE) is a powerful tool for analysing stresses and strains in the human body. One area of increasing interest is the skeletal musculature. This study evaluated modelling of skeletal muscle tissue using a combination of passive non-linear, viscoelastic solid elements and active Hill-type truss elements, the super-positioned muscle finite element (SMFE). The performance of the combined materials and elements was evaluated for eccentric motions by simulating a tensile experiment from a published study on a stimulated rabbit muscle including three different strain rates. It was also evaluated for isometric and concentric contractions. The resulting stress-strain curves had the same overall pattern as the experiments, with the main limitation being sensitivity to the active force-length relation. It was concluded that the SMFE could model active and passive muscle tissue at constant rate elongations for strains below failure, as well as isometric and concentric contractions.

Lead, selenium and nickel concentrations in epithelial ovarian cancer, borderline ovarian tumor and healthy ovarian tissues.

PubMed

Canaz, Emel; Kilinc, Metin; Sayar, Hamide; Kiran, Gurkan; Ozyurek, Eser

2017-09-01

Wide variation exists in ovarian cancer incidence rates suggesting the importance of environmental factors. Due to increasing environmental pollution, trace elements and heavy metals have drawn attention in studies defining the etiology of cancer, but scant data is available for ovarian cancer. Our aim was to compare the tissue concentrations of lead, selenium and nickel in epithelial ovarian cancer, borderline tumor and healthy ovarian tissues. The levels of lead, selenium and nickel were estimated using atomic absorption spectrophotometry in formalin-fixed paraffin-embedded tissue samples. Tests were carried out in 20 malignant epithelial ovarian cancer, 15 epithelial borderline tumor and 20 non-neoplastic healthy ovaries. Two samples were collected for borderline tumors, one from papillary projection and one from the smooth surface of cyst wall. Pb and Ni concentrations were found to be higher both in malignant and borderline tissues than those in healthy ovaries. Concentrations of Pb and Ni in malignant tissues, borderline papillary projections and capsular tissue samples were not different. Comparison of Se concentrations of malignant, borderline and healthy ovarian tissues did not reveal statistical difference. Studied metal levels were not found to be different in either papillary projection or in cyst wall of the borderline tumors. This study revealed the accumulation of lead and nickel in ovarian tissue is associated with borderline and malignant proliferation of the surface epithelium. Accumulation of these metals in epithelial ovarian cancer and borderline ovarian tumor has not been demonstrated before. Copyright © 2017 Elsevier GmbH. All rights reserved.

Highly conserved proximal promoter element harbouring paired Sox9-binding sites contributes to the tissue- and developmental stage-specific activity of the matrilin-1 gene.

PubMed

Rentsendorj, Otgonchimeg; Nagy, Andrea; Sinkó, Ildikó; Daraba, Andreea; Barta, Endre; Kiss, Ibolya

2005-08-01

The matrilin-1 gene has the unique feature that it is expressed in chondrocytes in a developmental stage-specific manner. Previously, we found that the chicken matrilin-1 long promoter with or without the intronic enhancer and the short promoter with the intronic enhancer restricted the transgene expression to the columnar proliferative chondroblasts and prehypertrophic chondrocytes of growth-plate cartilage in transgenic mice. To study whether the short promoter shared by these transgenes harbours cartilage-specific control elements, we generated transgenic mice expressing the LacZ reporter gene under the control of the matrilin-1 promoter between -338 and +67. Histological analysis of the founder embryos demonstrated relatively weak transgene activity in the developing chondrocranium, axial and appendicular skeleton with highest level of expression in the columnar proliferating chondroblasts and prehypertrophic chondrocytes. Computer analysis of the matrilin-1 genes of amniotes revealed a highly conserved Pe1 (proximal promoter element 1) and two less-conserved sequence blocks in the distal promoter region. The inverted Sox motifs of the Pe1 element interacted with chondrogenic transcription factors Sox9, L-Sox5 and Sox6 in vitro and another factor bound to the spacer region. Point mutations in the Sox motifs or in the spacer region interfered with or altered the formation of nucleoprotein complexes in vitro and significantly decreased the reporter gene activity in transient expression assays in chondrocytes. In vivo occupancy of the Sox motifs in genomic footprinting in the expressing cell type, but not in fibroblasts, also supported the involvement of Pe1 in the tissue-specific regulation of the gene. Our results indicate that interaction of Pe1 with distal DNA elements is required for the high level, cartilage- and developmental stage-specific transgene expression.

Background levels of some major, trace, and rare earth elements in indigenous plant species growing in Norway and the influence of soil acidification, soil parent material, and seasonal variation on these levels.

PubMed

Gjengedal, Elin; Martinsen, Thomas; Steinnes, Eiliv

2015-06-01

Baseline levels of 43 elements, including major, trace, and rare earth elements (REEs) in several native plant species growing in boreal and alpine areas, are presented. Focus is placed on species metal levels at different soil conditions, temporal variations in plant tissue metal concentrations, and interspecies variation in metal concentrations. Vegetation samples were collected at Sogndal, a pristine site in western Norway, and at Risdalsheia, an acidified site in southernmost Norway. Metal concentrations in the different species sampled in western Norway are compared with relevant literature data from Norway, Finland, and northwest Russia, assumed to represent natural conditions. Except for aluminium (Al) and macronutrients, the levels of metals were generally lower in western Norway than in southern Norway and may be considered close to natural background levels. In southern Norway, the levels of cadmium (Cd) and lead (Pb) in particular appear to be affected by air pollution, either by direct atmospheric supply or through soil acidification. Levels of some elements show considerable variability between as well as within plant species. Calcium (Ca), magnesium (Mg), and potassium (K) are higher in most species at Sogndal compared to Risdalsheia, despite increased extractable concentrations in surface soil in the south, probably attributed to different buffer mechanisms in surface soil. Antagonism on plant uptake is suggested between Ca, Mg, and K on one hand and Al on the other. Tolerance among calcifuges to acid conditions and a particular ability to detoxify or avoid uptake of Al ions are noticeable for Vaccinium vitis-idaea.

Inorganic elements in green sea turtles (Chelonia mydas): relationships among external and internal tissues.

PubMed

Faust, Derek R; Hooper, Michael J; Cobb, George P; Barnes, Melanie; Shaver, Donna; Ertolacci, Shauna; Smith, Philip N

2014-09-01

Inorganic elements from anthropogenic sources have entered marine environments worldwide and are detectable in marine organisms, including sea turtles. Threatened and endangered classifications of sea turtles have heretofore made assessments of contaminant concentrations difficult because of regulatory restrictions on obtaining samples using nonlethal techniques. In the present study, claw and skin biopsy samples were examined as potential indicators of internal tissue burdens in green sea turtles (Chelonia mydas). Significant relationships were observed between claw and liver, and claw and muscle concentrations of mercury, nickel, arsenic, and selenium (p < 0.05). Similarly, significant relationships were observed between skin biopsy concentrations and those in liver, kidney, and muscle tissues for mercury, arsenic, selenium, and vanadium (p < 0.05). Concentrations of arsenic, barium, chromium, nickel, strontium, vanadium, and zinc in claws and skin biopsies were substantially elevated when compared with all other tissues, indicating that these highly keratinized tissues may represent sequestration or excretion pathways. Correlations between standard carapace length and cobalt, lead, and manganese concentrations were observed (p < 0.05), indicating that tissue concentrations of these elements may be related to age and size. Results suggest that claws may indeed be useful indicators of mercury and nickel concentrations in liver and muscle tissues, whereas skin biopsy inorganic element concentrations may be better suited as indicators of mercury, selenium, and vanadium concentrations in liver, kidney, and muscle tissues of green sea turtles. © 2014 SETAC.

Concurrent musculoskeletal dynamics and finite element analysis predicts altered gait patterns to reduce foot tissue loading.

PubMed

Halloran, Jason P; Ackermann, Marko; Erdemir, Ahmet; van den Bogert, Antonie J

2010-10-19

Current computational methods for simulating locomotion have primarily used muscle-driven multibody dynamics, in which neuromuscular control is optimized. Such simulations generally represent joints and soft tissue as simple kinematic or elastic elements for computational efficiency. These assumptions limit application in studies such as ligament injury or osteoarthritis, where local tissue loading must be predicted. Conversely, tissue can be simulated using the finite element method with assumed or measured boundary conditions, but this does not represent the effects of whole body dynamics and neuromuscular control. Coupling the two domains would overcome these limitations and allow prediction of movement strategies guided by tissue stresses. Here we demonstrate this concept in a gait simulation where a musculoskeletal model is coupled to a finite element representation of the foot. Predictive simulations incorporated peak plantar tissue deformation into the objective of the movement optimization, as well as terms to track normative gait data and minimize fatigue. Two optimizations were performed, first without the strain minimization term and second with the term. Convergence to realistic gait patterns was achieved with the second optimization realizing a 44% reduction in peak tissue strain energy density. The study demonstrated that it is possible to alter computationally predicted neuromuscular control to minimize tissue strain while including desired kinematic and muscular behavior. Future work should include experimental validation before application of the methodology to patient care. Copyright © 2010 Elsevier Ltd. All rights reserved.

Testing the use of juvenile Salmo trutta L. as biomonitors of heavy metal pollution in freshwater.

PubMed

Lamas, S; Fernández, J A; Aboal, J R; Carballeira, A

2007-02-01

Individual specimens of Salmo trutta were captured, from four sampling sites in Galician rivers (NW Spain) affected by different types of contamination: diffuse urban waste, run-off from an unrestored dump at a copper mine and waste from a fish farm. The ages of the captured trouts were established and only those belonging to the 1+ age class were selected for study. The liver and kidney were removed from each fish and analysed to determine the tissue concentrations of Cu, Fe and Zn. The results obtained showed that: (i) the use of 1+ individuals allowed differentiation of contamination scenarios on the basis of the tissue concentrations of metal; (ii) the use of 1+ individuals allowed standardization of the time of exposure, which was sufficiently long for differential uptake to have taken place; (iii) liver tissue provided the best results as, less effort was required than for processing kidney tissue, and significant differences between sampling sites were detected because the intrapopulational variability in metal levels was lower than for kidney, and (iv) the levels of elements detected were not affected by basal tissue concentrations or residual concentrations due to past contamination, which older trouts may have been exposed to. In addition, the use of 1+ trout may provide better results in annual environmental sampling surveys.

Histologic evaluation of human pulp tissue after orthodontic intrusion.

PubMed

Lazzaretti, Dieison Nardi; Bortoluzzi, Gianna Steffens; Torres Fernandes, Lauren Fioreze; Rodriguez, Rubens; Grehs, Renésio Armindo; Martins Hartmann, Mateus Silveira

2014-10-01

The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination. The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope. The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements. The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Origin and evolution of the integumentary skeleton in non-tetrapod vertebrates

PubMed Central

Sire, Jean-Yves; Donoghue, Philip C J; Vickaryous, Matthews K

2009-01-01

Most non-tetrapod vertebrates develop mineralized extra-oral elements within the integument. Known collectively as the integumentary skeleton, these elements represent the structurally diverse skin-bound contribution to the dermal skeleton. In this review we begin by summarizing what is known about the histological diversity of the four main groups of integumentary skeletal tissues: hypermineralized (capping) tissues; dentine; plywood-like tissues; and bone. For most modern taxa, the integumentary skeleton has undergone widespread reduction and modification often rendering the homology and relationships of these elements confused and uncertain. Fundamentally, however, all integumentary skeletal elements are derived (alone or in combination) from only two types of cell condensations: odontogenic and osteogenic condensations. We review the origin and diversification of the integumentary skeleton in aquatic non-tetrapods (including stem gnathostomes), focusing on tissues derived from odontogenic (hypermineralized tissues, dentines and elasmodine) and osteogenic (bone tissues) cell condensations. The novelty of our new scenario of integumentary skeletal evolution resides in the demonstration that elasmodine, the main component of elasmoid scales, is odontogenic in origin. Based on available data we propose that elasmodine is a form of lamellar dentine. Given its widespread distribution in non-tetrapod lineages we further propose that elasmodine is a very ancient tissue in vertebrates and predict that it will be found in ancestral rhombic scales and cosmoid scales. PMID:19422423

Metals in coastal zones impacted with urban and industrial wastes: Insights on the metal accumulation pattern in fish species

NASA Astrophysics Data System (ADS)

La Colla, Noelia S.; Botté, Sandra E.; Marcovecchio, Jorge E.

2018-05-01

The pollution of aquatic environments is a worldwide problem of difficult solution since these areas are used for the disposal and dilution of anthropogenic wastes. This study evaluated the concentrations of Cd, Cu, Ni and Zn in the gills, liver and muscle tissues of six economically important fish species from the Bahía Blanca estuary in Argentina, a coastal environment that is under anthropogenic pressure. Metal contents in 147 fish samples were determined by digestion and a subsequent analysis with an ICP OES. The concentrations (μg/g, wet weight) of each metal in the fish tissues ranged from below the limit of detection for the four metals to 5.2 in the case of Cd, 340 for Cu, 20 for Ni, and 101 for Zn. The results suggested that metal burden in fishes varied with the species and metal elements, with Cd, Cu and Zn mean maximum accumulation towards the liver tissue. Ni showed a high number of samples with concentrations below the limit of detection. Among species, Cynoscion guatucupa was found to have the highest concentrations of Cu and Zn in the liver tissues, whereas the gills and liver tissues of Mustelus schmitti showed the lowest levels of Ni and Zn. As regards the human health risks, two samples of muscle tissue belonging to C. guatucupa reached to Cd levels that exceeded the permissible levels for human consumption. Moreover, the estimated daily intakes calculated suggest that people would not experience significant health risks from the intake of individual metals through fish consumption.

DNA methylation and hydroxymethylation analyses of the active LINE-1 subfamilies in mice.

PubMed

Murata, Yui; Bundo, Miki; Ueda, Junko; Kubota-Sakashita, Mie; Kasai, Kiyoto; Kato, Tadafumi; Iwamoto, Kazuya

2017-10-19

Retrotransposon long interspersed nuclear element-1 (LINE-1) occupies a large proportion of the mammalian genome, comprising approximately 100,000 genomic copies in mice. Epigenetic status of the 5' untranslated region (5'-UTR) of LINE-1 is critical for its promoter activity. DNA methylation levels in the 5'-UTR of human active LINE-1 subfamily can be measured by well-established methods, such as a pyrosequencing-based assay. However, because of the considerable sequence and structural diversity in LINE-1 among species, methods for such assays should be adapted for the species of interest. Here we developed pyrosequencing-based assays to examine methylcytosine (mC) and hydroxymethylcytosine (hmC) levels of the three active LINE-1 subfamilies in mice (TfI, A, and GfII). Using these assays, we quantified mC and hmC levels in four brain regions and four nonbrain tissues including tail, heart, testis, and ovary. We observed tissue- and subfamily-specific mC and hmC differences. We also found that mC levels were strongly correlated among different brain regions, but mC levels of the testis showed a poor correlation with those of other tissues. Interestingly, mC levels in the A and GfII subfamilies were highly correlated, possibly reflecting their close evolutionary relationship. Our assays will be useful for exploring the epigenetic regulation of the active LINE-1 subfamilies in mice.

Correlations of trace elements in breast human tissues: Evaluation of spatial distribution using μ-XRF

NASA Astrophysics Data System (ADS)

Silva, Marina Piacenti da; Silva, Deisy Mara da; Ribeiro-Silva, Alfredo; Poletti, Martin Eduardo

2012-05-01

The aim of this work is to investigate microscopic correlations between trace elements in breast human tissues. A synchrotron X-ray fluorescence microprobe system (μ-XRF) was used to obtain two-dimensional distribution of trace element Ca, Fe, Cu and Zn in normal (6 samples) and malignant (14 samples) breast tissues. The experiment was performed in X-ray Fluorescence beam line at Laboratório Nacional de Luz Síncrotron (LNLS), Campinas, Brazil. The white microbeam was generated with a fine conical capillary with a 20 μm output diameter. The samples were supported on a XYZ table. An optical microscope with motorized zoom was used for sample positioning and choice the area to be scanned. Automatic two-dimensional scans were programmed and performed with steps of 30 μm in each direction (x, y) on the selected area. The fluorescence signals were recorded using a Si(Li) detector, positioned at 90 degrees with respect to the incident beam, with a collection time of 10 s per point. The elemental maps obtained from each sample were overlap to observe correlation between trace elements. Qualitative results showed that the pairs of elements Ca-Zn and Fe-Cu could to be correlated in malignant breast tissues. Quantitative results, achieved by Spearman correlation tests, indicate that there is a spatial correlation between these pairs of elements (p < 0.001) suggesting the importance of these elements in metabolic processes associated with the development of the tumor.

A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

PubMed

Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel

2017-09-15

Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (E MREE =0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

The in vivo plantar soft tissue mechanical property under the metatarsal head: implications of tissues׳ joint-angle dependent response in foot finite element modeling.

PubMed

Chen, Wen-Ming; Lee, Sung-Jae; Lee, Peter Vee Sin

2014-12-01

Material properties of the plantar soft tissue have not been well quantified in vivo (i.e., from life subjects) nor for areas other than the heel pad. This study explored an in vivo investigation of the plantar soft tissue material behavior under the metatarsal head (MTH). We used a novel device collecting indentation data at controlled metatarsophalangeal joint angles. Combined with inverse analysis, tissues׳ joint-angle dependent material properties were identified. The results showed that the soft tissue under MTH exhibited joint-angle dependent material responses, and the computed parameters using the Ogden material model were 51.3% and 30.9% larger in the dorsiflexed than in the neutral positions, respectively. Using derived parameters in subject-specific foot finite element models revealed only those models that used tissues׳ joint-dependent responses could reproduce the known plantar pressure pattern under the MTH. It is suggested that, to further improve specificity of the personalized foot finite element models, quantitative mechanical properties of the tissue inclusive of the effects of metatarsophalangeal joint dorsiflexion are needed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prompt gamma-ray emission from biological tissues during proton irradiation: a preliminary study.

PubMed

Polf, J C; Peterson, S; Ciangaru, G; Gillin, M; Beddar, S

2009-02-07

In this paper, we present the results of a preliminary study of secondary 'prompt' gamma-ray emission produced by proton-nuclear interactions within tissue during proton radiotherapy. Monte Carlo simulations were performed for mono-energetic proton beams, ranging from 2.5 MeV to 250 MeV, irradiating elemental and tissue targets. Calculations of the emission spectra from different biological tissues and their elemental components were made. Also, prompt gamma rays emitted during delivery of a clinical proton spread-out Bragg peak (SOBP) in a homogeneous water phantom and a water phantom containing heterogeneous tissue inserts were calculated to study the correlation between prompt gamma-ray production and proton dose delivery. The results show that the prompt gamma-ray spectra differ significantly for each type of tissue studied. The relative intensity of the characteristic gamma rays emitted from a given tissue was shown to be proportional to the concentration of each element in that tissue. A strong correlation was found between the delivered SOBP dose distribution and the characteristic prompt gamma-ray production. Based on these results, we discuss the potential use of prompt gamma-ray emission as a method to verify the accuracy and efficacy of doses delivered with proton radiotherapy.

Intraoral conversion of occlusal force to electricity and magnetism by biting of piezoelectric elements.

PubMed

Kameda, Takashi; Ohkuma, Kazuo; Sano, Natsuki; Ogura, Hideo; Terada, Kazuto

2012-01-01

Very weak electrical, magnetic and ultrasound signal stimulations are known to promote the formation, metabolism, restoration and stability of bone and surrounding tissues after treatment and operations. We have therefore investigated the possibility of intraoral generation of electricity and magnetism by occlusal force in an in vitro study. Biting bimorph piezoelectric elements with lead zirconate titanate (PZT) using dental models generated appropriate magnetism for bone formation, i. e. 0.5-0.6 gauss, and lower electric currents and higher voltages, i. e. 2.0-6.0 μA at 10-22 V (appropriate levels are 30 μA and 1.25 V), as observed by a universal testing machine. The electric currents and voltages could be changed using amplifier circuits. These results show that intraoral generation of electricity and magnetism is possible and could provide post-operative stabilization and activation of treated areas of bone and the surrounding tissues directly and/or indirectly by electrical, magnetic and ultrasound stimulation, which could accelerate healing.

A perspective on high-frequency ultrasound for medical applications

NASA Astrophysics Data System (ADS)

Mamou, Jonathan; Aristizába, Orlando; Silverman, Ronald H.; Ketterling, Jeffrey A.

2010-01-01

High-frequency ultrasound (HFU, >15 MHz) is a rapidly developing field. HFU is currently used and investigated for ophthalmologic, dermatologic, intravascular, and small-animal imaging. HFU offers a non-invasive means to investigate tissue at the microscopic level with resolutions often better than 100 μm. However, fine resolution is only obtained over the limited depth-of-field (˜1 mm) of single-element spherically-focused transducers typically used for HFU applications. Another limitation is penetration depth because most biological tissues have large attenuation at high frequencies. In this study, two 5-element annular arrays with center frequencies of 17 and 34 MHz were fabricated and methods were developed to obtain images with increased penetration depth and depth-of-field. These methods were used in ophthalmologic and small-animal imaging studies. Improved blood sensitivity was obtained when a phantom mimicking a vitreous hemorrhage was imaged. Central-nervous systems of 12.5-day-old mouse embryos were imaged in utero and in three dimensions for the first time.

A finger-free wrist-worn pulse oximeter for the monitoring of chronic obstructive pulmonary disease

NASA Astrophysics Data System (ADS)

Chu, Chang-Sheng; Chuang, Shuang-Chao; Lee, Yeh Wen; Fan, Chih-Hsun; Chung, Lung Pin; Li, Yu-Tang; Chen, Jyh-Chern

2016-03-01

Herein, a finger-free wrist-worn pulse oximeter is presented. This device allows patients to measure blood oxygen level and pulse rate without hindering their normal finger movement. This wrist-worn pulse oximeter is built with a reflectance oximetry sensor, which consists of light emitting diodes and photodiode light detectors located side by side. This reflectance oximetry sensor is covered with an optical element with micro structured surface. This micro structured optical element is designed to modulate photon propagation beneath the skin tissue so that the photoplethysmogram signals of reflected lights or backscattered lights detected by the photodetector are therefore enhanced.

Diagnostic Analysis Of Ultrasound Data

DOEpatents

Chambers, David H.; Mast, Jeffrey; Azevedo, Stephen G.; Wuebbeling, Frank; Natterer, Frank; Duric, Neb; Littrup, Peter J.; Holsapple, Earle

2006-01-10

A method and apparatus are provided for investigating tissue in which acoustic data are derived from scattering a plurality of pulsed spherical or cylindrical acoustic waves from a plurality of transmission elements through the tissue to a plurality of receiving elements. The acoustic data, which include a mix of reflected and transmitted acoustic waves, are received and digitized, and a representation of a portion of the tissue is generated from the digitized acoustic data.

Influence of soil chemistry on metal and bioessential element concentrations in nymphal and adult periodical cicadas (Magicicada spp.).

PubMed

Robinson, G R; Sibrell, P L; Boughton, C J; Yang, L H

2007-03-15

Metal and bioessential element concentrations were measured in three species of 17-year periodical cicadas (Magicicada spp.) to determine how cicada tissue chemistry is affected by soil chemistry, measure the bioavailability of metals from both uncontaminated and lead-arsenate-pesticide contaminated soils, and assess the potential risks of observed metal contamination for wildlife. Periodical cicada nymphs feed on root xylem fluids for 13 or 17 years of underground development. The nymphs then emerge synchronously at high densities, before leaving their nymphal keratin exoskeleton and molting into their adult form. Cicadas are an important food source for birds and animals during emergence events, and influence nutrient cycles in woodland ecosystems. Nymphal exoskeletons and whole adult cicadas were sampled in Clarke and Frederick Counties, Virginia and Berkeley and Jefferson Counties, West Virginia during the Brood X emergence in May and June, 2004. Elements, such as Al, Fe, and Pb, are strongly enriched in the nymphal exoskeleton relative to the adult body; Cu and Zn are enriched in bodies. Concentrations of Fe and Pb, when normalized to relatively inert soil constituents such as Al and Ce, are similar in both the molt exoskeleton and their host soil, implying that passive assimilation through prolonged soil contact (adhesion or adsorption) might control these metal concentrations. Normalized concentrations of bioessential elements, such as S, P, K, Ca, Mn, Cu, Zn, and Mo, and chalcophile (sulfur-loving) elements, such as As, Se, and Au, indicate strong enrichment in cicada tissues relative to soil, implying selective absorption and retention by xylem fluids, the cicada nymphs themselves, or both. Element enrichment patterns in cicada tissues are similar to enrichment patterns observed in xylem fluids from tree roots. Chalcophile elements and heavy metals accumulate in keratin-rich tissues and may bind to sulfhydryl groups. Metal concentrations in the nymphal exoskeleton show a positive correlation with soil metal concentrations, with Au exhibiting particularly strong enrichment in the exoskeleton relative to soil concentrations. Metal concentrations in adult bodies do not correlate with soil chemistry. Bioessential elements S, Ca, Mn, Fe, and Zn differed by sex in adults, whereas Na, Mg, K, Ca, Mn, Fe, Zn, and As differed by species. Body concentrations of Ca differed by site conditions (orchard or reference setting). The high Pb contents of orchard soils contaminated by arsenical pesticide residues might inhibit Ca uptake by cicada nymphs. The adult cicadas contain concentrations of metals similar to, or less than, other invertebrates, such as earthworms. There does not appear to be a dietary threat to birds or other consumers of adult cicadas based on Maximum Tolerable Dietary Level (MTDL) Guidelines developed for agricultural animals.

Influence of soil chemistry on metal and bioessential element concentrations in nymphal and adult periodical cicadas (Magicicada spp.)

USGS Publications Warehouse

Robinson, G.R.; Sibrell, P.L.; Boughton, C.J.; Yang, L.H.

2007-01-01

Metal and bioessential element concentrations were measured in three species of 17-year periodical cicadas (Magicicada spp.) to determine how cicada tissue chemistry is affected by soil chemistry, measure the bioavailability of metals from both uncontaminated and lead-arsenate-pesticide contaminated soils, and assess the potential risks of observed metal contamination for wildlife. Periodical cicada nymphs feed on root xylem fluids for 13 or 17??years of underground development. The nymphs then emerge synchronously at high densities, before leaving their nymphal keratin exoskeleton and molting into their adult form. Cicadas are an important food source for birds and animals during emergence events, and influence nutrient cycles in woodland ecosystems. Nymphal exoskeletons and whole adult cicadas were sampled in Clarke and Frederick Counties, Virginia and Berkeley and Jefferson Counties, West Virginia during the Brood X emergence in May and June, 2004. Elements, such as Al, Fe, and Pb, are strongly enriched in the nymphal exoskeleton relative to the adult body; Cu and Zn are enriched in bodies. Concentrations of Fe and Pb, when normalized to relatively inert soil constituents such as Al and Ce, are similar in both the molt exoskeleton and their host soil, implying that passive assimilation through prolonged soil contact (adhesion or adsorption) might control these metal concentrations. Normalized concentrations of bioessential elements, such as S, P, K, Ca, Mn, Cu, Zn, and Mo, and chalcophile (sulfur-loving) elements, such as As, Se, and Au, indicate strong enrichment in cicada tissues relative to soil, implying selective absorption and retention by xylem fluids, the cicada nymphs themselves, or both. Element enrichment patterns in cicada tissues are similar to enrichment patterns observed in xylem fluids from tree roots. Chalcophile elements and heavy metals accumulate in keratin-rich tissues and may bind to sulfhydryl groups. Metal concentrations in the nymphal exoskeleton show a positive correlation with soil metal concentrations, with Au exhibiting particularly strong enrichment in the exoskeleton relative to soil concentrations. Metal concentrations in adult bodies do not correlate with soil chemistry. Bioessential elements S, Ca, Mn, Fe, and Zn differed by sex in adults, whereas Na, Mg, K, Ca, Mn, Fe, Zn, and As differed by species. Body concentrations of Ca differed by site conditions (orchard or reference setting). The high Pb contents of orchard soils contaminated by arsenical pesticide residues might inhibit Ca uptake by cicada nymphs. The adult cicadas contain concentrations of metals similar to, or less than, other invertebrates, such as earthworms. There does not appear to be a dietary threat to birds or other consumers of adult cicadas based on Maximum Tolerable Dietary Level (MTDL) Guidelines developed for agricultural animals.

Woody tissue analysis using an element ratio technique (DRIS)

Treesearch

Kurt H. Riitters; L.F. Ohmann; D.F. Grigal

1991-01-01

The diagnosis and recommendation integrated system (DRIS) was used to describe the variation of 12 elements in woody tree tissue and balsam fir (Abies balsamae (L.) Mill.), sugar maple (Acer saccharum Marsh.), jack pine (Pinus banksiana Lamb.), red pine (Pinus resinosa alt.), and aspen (

Applying an analytical method to study neutron behavior for dosimetry

NASA Astrophysics Data System (ADS)

Shirazi, S. A. Mousavi

2016-12-01

In this investigation, a new dosimetry process is studied by applying an analytical method. This novel process is associated with a human liver tissue. The human liver tissue has compositions including water, glycogen and etc. In this study, organic compound materials of liver are decomposed into their constituent elements based upon mass percentage and density of every element. The absorbed doses are computed by analytical method in all constituent elements of liver tissue. This analytical method is introduced applying mathematical equations based on neutron behavior and neutron collision rules. The results show that the absorbed doses are converged for neutron energy below 15MeV. This method can be applied to study the interaction of neutrons in other tissues and estimating the absorbed dose for a wide range of neutron energy.

FT-Raman study of deferoxamine and deferiprone exhibits potent amelioration of structural changes in the liver tissues of mice due to aluminum exposure

NASA Astrophysics Data System (ADS)

Sivakumar, S.; Khatiwada, Chandra Prasad; Sivasubramanian, J.; Raja, B.

2014-01-01

The present study inform the alterations on major biochemical constituents such as lipids, proteins, nucleic acids and glycogen along with phosphodiester linkages, tryptophan bands, tyrosine doublet, disulfide bridge conformations, aliphatic hydrophobic residue, and salt bridges in liver tissues of mice using Fourier transform Raman spectroscopy. In amide I, amide II and amide III, the area value significant decrease due structural alteration in the protein, glycogen and triglycerides levels but chelating agents DFP and DFO upturned it. Morphology changes by aluminium induced alterations and recovery by chelating agents within liver tissues known by histopathological examination. Concentrations of trace elements were found by ICP-OES. FT-Raman study was revealed to be in agreement with biochemical studies and demonstrate that it can successfully specify the molecular alteration in liver tissues. The tyrosyl doublet ratio I899/I831 decreases more in aluminum intoxicated tissues but treatment with DFP and DFO + DFP brings back to nearer control value. This indicates more variation in the hydrogen bonding of the phenolic hydroxyl group due to aluminum poisoning. The decreased Raman intensity ratio (I3220/I3400) observed in the aluminum induced tissues suggests a decreased water domain size, which could be interpreted in terms of weaker hydrogen-bonded molecular species of water in the aluminum intoxicated liver tissues. Finally, FT-Raman spectroscopy might be a useful tool for obtained successfully to indicate the molecular level changes.

The histological and elemental characterisation of corrosion particles from taper junctions.

PubMed

Munir, S; Oliver, R A; Zicat, B; Walter, W L; Walter, W K; Walsh, W R

2016-09-01

This study aimed to characterise and qualitatively grade the severity of the corrosion particles released into the hip joint following taper corrosion. The 26 cases examined were CoC/ABG Modular (n = 13) and ASR/SROM (n = 13). Blood serum metal ion levels were collected before and after revision surgery. The haematoxylin and eosin tissue sections were graded on the presence of fibrin exudates, necrosis, inflammatory cells and corrosion products. The corrosion products were identified based on visible observation and graded on abundance. Two independent observers blinded to the clinical patient findings scored all cases. Elemental analysis was performed on corrosion products within tissue sections. X-Ray diffraction was used to identify crystalline structures present in taper debris. The CoC/ABG Modular patients had a mean age of 64.6 years (49.4 to 76.5) and ASR/SROM patients had a mean age of 58.2 years (33.3 to 85.6). The mean time in situ for CoC/ABG was 4.9 years (2 to 6.4) and ASR/SROM was 6.1 years (2.5 to 8.1). The blood serum metal ion concentrations reduced following revision surgery with the exception of Cr levels within CoC/ABG. The grading of tissue sections showed that the macrophage response and metal debris were significantly higher for the ASR/SROM patients (p < 0.001). The brown/red particles were significantly higher for ASR/SROM (p < 0.001). The taper debris contained traces of titanium oxide, chromium oxide and aluminium nitride. This study characterised and qualitatively graded the severity of the corrosion particles released into the hip joint from tapers that had corrosion damage.Cite this article: S. Munir, R. A. Oliver, B. Zicat, W. L. Walter, W. K. Walter, W. R. Walsh. The histological and elemental characterisation of corrosion particles from taper junctions. Bone Joint Res 2016;5:370-378. DOI: 10.1302/2046-3758.59.2000507. © 2016 Munir et al.

Insulin resistance and diabetes mellitus in transgenic mice expressing nuclear SREBP-1c in adipose tissue: model for congenital generalized lipodystrophy

PubMed Central

Shimomura, Iichiro; Hammer, Robert E.; Richardson, James A.; Ikemoto, Shinji; Bashmakov, Yuriy; Goldstein, Joseph L.; Brown, Michael S.

1998-01-01

Overexpression of the nuclear form of sterol regulatory element-binding protein-1c (nSREBP-1c/ADD1) in cultured 3T3-L1 preadipocytes was shown previously to promote adipocyte differentiation. Here, we produced transgenic mice that overexpress nSREBP-1c in adipose tissue under the control of the adipocyte-specific aP2 enhancer/promoter. A syndrome with the following features was observed: (1) Disordered differentiation of adipose tissue. White fat failed to differentiate fully, and the size of white fat depots was markedly decreased. Brown fat was hypertrophic and contained fat-laden cells resembling immature white fat. Levels of mRNA encoding adipocyte differentiation markers (C/EBPα, PPARγ, adipsin, leptin, UCP1) were reduced, but levels of Pref-1 and TNFα were increased. (2) Marked insulin resistance with 60-fold elevation in plasma insulin. (3) Diabetes mellitus with elevated blood glucose (>300 mg/dl) that failed to decline when insulin was injected. (4) Fatty liver from birth and elevated plasma triglyceride levels later in life. These mice exhibit many of the features of congenital generalized lipodystrophy (CGL), an autosomal recessive disorder in humans. PMID:9784493

Consistent levels of A-to-I RNA editing across individuals in coding sequences and non-conserved Alu repeats

PubMed Central

2010-01-01

Background Adenosine to inosine (A-to-I) RNA-editing is an essential post-transcriptional mechanism that occurs in numerous sites in the human transcriptome, mainly within Alu repeats. It has been shown to have consistent levels of editing across individuals in a few targets in the human brain and altered in several human pathologies. However, the variability across human individuals of editing levels in other tissues has not been studied so far. Results Here, we analyzed 32 skin samples, looking at A-to-I editing level in three genes within coding sequences and in the Alu repeats of six different genes. We observed highly consistent editing levels across different individuals as well as across tissues, not only in coding targets but, surprisingly, also in the non evolutionary conserved Alu repeats. Conclusions Our findings suggest that A-to-I RNA-editing of Alu elements is a tightly regulated process and, as such, might have been recruited in the course of primate evolution for post-transcriptional regulatory mechanisms. PMID:21029430

Higher trophic level affects nutrient, silicon, metal(loid), and radionuclide mobilization from freshwater sediments

NASA Astrophysics Data System (ADS)

Schaller, Jörg; Planer-Friedrich, Britta

2017-04-01

Organic sediments in aquatic ecosystems are well known sinks for nutrients, silicon, and metal(loid)s. Organic matter-decomposing organisms like invertebrate shredders, grazers, bioturbators, and filter feeder are key-species for the carbon and energy turnover within the decomposer community. We could show that invertebrate shredders and grazer affect element fixation or remobilization by changing binding properties of organic sediments and the attached biofilm. Bioturbators affect element fixation or remobilization by changing redox conditions within the uppermost sediment layer. Last but not least filter feeders, like the zebra mussel Dreissena polymorpha, an invasive organism in North American and European freshwater ecosystems significantly contributed to element mobilization of silicon, iron, phosphorus, arsenic, and copper and to immobilization of uranium (p<0.001), probably driven by redox conditions, microbial activity within the gut system, or active control of element homeostasis. Except of the filter feeder D. polymorpha, the invertebrates are able to minimize the accumulation of non-nutrient elements due to specific strategies, which is an important strategy for species living in systems tending to element accumulation. However, D. polymorpha revealed a significant uptake and accumulation of arsenic, copper, iron, and especially uranium both into the soft body tissues and the seashell. This accumulation by D. polymorpha is in line with previous observations of metal(loid) accumulation from biomonitoring studies. In summary, higher trophic level strongly contributes to element fixation or remobilization in aquatic systems.

Elemental concentration analysis in brain structures from young, adult and old Wistar rats by total reflection X-ray fluorescence with synchrotron radiation

NASA Astrophysics Data System (ADS)

Serpa, R. F. B.; de Jesus, E. F. O.; Anjos, M. J.; do Carmo, M. G. T.; Moreira, S.; Rocha, M. S.; Martinez, A. M. B.; Lopes, R. T.

2006-11-01

The knowledge of the spatial distribution and the local concentration of trace elements in tissues are of great importance since trace elements are involved in a number of metabolic and physiological processes in the human body, and their deficiency and excess may lead to different metabolic disorders. In this way, the main goal of this work is to compare the elemental concentration in different brain structures, namely temporal cortex, entorhinal cortex, visual cortex and hippocampus, from Wistar female rats ( n = 15) with different ages: 2, 8 and 48 weeks. The measurements were performed at the Synchrotron Light Brazilian Laboratory, Campinas, São Paulo, Brazil. In the entorhinal cortex, the following elements decreased with age: Zn, S, Cl, K, Ca and Br. In the temporal cortex, Ca, Fe and Br levels increased with aging and on the other hand, P, S, Cl, K and Rb levels decreased with aging. In the visual cortex almost all the elements decreased with aging: Cl, Ca, Fe, Ni and Zn. In the hippocampus, in turn, most of the elements identified, increased with aging: Al, P, S, K, Fe, Cu, Zn and Rb. The increase of Fe with aging in the hippocampus is an important fact that will be studied, since it is involved in oxidative stress. It is believed that oxidative stress is the one of the main causes responsible for neuronal death in Parkinson's disease.

Iron supplementation at high altitudes induces inflammation and oxidative injury to lung tissues in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salama, Samir A., E-mail: salama.3@buckeyemail.osu.edu; Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11751; Department of Pharmacology and GTMR Unit, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974

2014-01-01

Exposure to high altitudes is associated with hypoxia and increased vulnerability to oxidative stress. Polycythemia (increased number of circulating erythrocytes) develops to compensate the high altitude associated hypoxia. Iron supplementation is, thus, recommended to meet the demand for the physiological polycythemia. Iron is a major player in redox reactions and may exacerbate the high altitudes-associated oxidative stress. The aim of this study was to explore the potential iron-induced oxidative lung tissue injury in rats at high altitudes (6000 ft above the sea level). Iron supplementation (2 mg elemental iron/kg, once daily for 15 days) induced histopathological changes to lung tissuesmore » that include severe congestion, dilatation of the blood vessels, emphysema in the air alveoli, and peribronchial inflammatory cell infiltration. The levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), lipid peroxidation product and protein carbonyl content in lung tissues were significantly elevated. Moreover, the levels of reduced glutathione and total antioxidant capacity were significantly reduced. Co-administration of trolox, a water soluble vitamin E analog (25 mg/kg, once daily for the last 7 days of iron supplementation), alleviated the lung histological impairments, significantly decreased the pro-inflammatory cytokines, and restored the oxidative stress markers. Together, our findings indicate that iron supplementation at high altitudes induces lung tissue injury in rats. This injury could be mediated through excessive production of reactive oxygen species and induction of inflammatory responses. The study highlights the tissue injury induced by iron supplementation at high altitudes and suggests the co-administration of antioxidants such as trolox as protective measures. - Highlights: • Iron supplementation at high altitudes induced lung histological changes in rats. • Iron induced oxidative stress in lung tissues of rats at high altitudes. • Iron increased the levels of IL-1β, IL-6 and TNF-α in lung tissues at high altitudes. • Trolox alleviated the iron-induced histological and biochemical changes to the lungs.« less

Do fattening process and biological parameters affect the accumulation of metals in Atlantic bluefin tuna?

PubMed

Milatou, Niki; Dassenakis, Manos; Megalofonou, Persefoni

2015-01-01

The objective of this study was to determine the current levels of heavy metals and trace elements in Atlantic bluefin tuna muscle tissues and how they are influenced by the fattening process and various life history parameters to ascertain whether the concentrations in muscle tissue exceed the maximum levels defined by the European Commission Decision and to evaluate the health risk posed by fish consumption. A total of 20 bluefin tuna reared in sea cages, ranging from 160 to 295 cm in length and from 80 to 540 kg in weight, were sampled from a bluefin tuna farm in the Ionian Sea. The condition factor K of each specimen was calculated and their age was estimated. Heavy metal and trace element (Hg, Zn, Fe and Cu) contents were determined in muscle tissue using cold vapour atomic absorption spectrometry and flame and graphite furnace atomic absorption spectrometry. The total Hg concentrations ranged from 0.28 to 1.28 mg kg(-1) w/w, Zn from 5.81 to 76.37 mg kg(-1) w/w, Fe from 12.14 to 39.58 mg kg(-1) w/w, and Cu from 0.36 to 0.94 mg kg(-1) w/w. Only 5% of the muscle samples of tuna contained Hg above the maximum level laid down by the European Commission Decision. Moreover, 15% of the muscle samples contained Zn above the maximum level, while Fe and Cu concentrations were within the acceptable tolerable guideline values. The reared bluefin tuna had lower concentrations of Hg than the wild ones from the Mediterranean Sea. Hg and Fe concentrations showed a positive relationship with size and age of bluefin tuna, whereas negative relationships were found for the concentrations of Zn and Cu. The estimated dietary intake values of the analysed metals were mostly below the derived guidelines.

Polymorphism and methylation patterns in Agave tequilana Weber var. 'Azul' plants propagated asexually by three different methods.

PubMed

Díaz-Martínez, Miriam; Nava-Cedillo, Alejandro; Guzmán-López, José Alfredo; Escobar-Guzmán, Rocío; Simpson, June

2012-04-01

Genetic variation in three forms of asexually propagated Agave tequilana Weber var. 'Azul' plants namely offsets, bulbils and in vitro cultured individuals was studied by AFLP analysis. Low levels of variation were observed between mother plants and offsets and a higher level between mother plant and bulbils. Families obtained from commercial plantations showed lower levels of variation in comparison to families grown as ornamentals. No variation was observed between the original explant and four generations of in vitro cultured plants. Epigenetic variation was also studied by analyzing changes in methylation patterns between mother plants and offspring in each form of asexual reproduction. Offsets and bulbils showed an overall decrease in methylation whereas in vitro cultured plants showed patterns specific to each generation: Generations 1 and 4 showed overall demethylation whereas Generations 2 and 3 showed increased methylation. Analysis of ESTs associated with transposable elements revealed higher proportions of ESTs from Ty1-copia-like, Gypsy and CACTA transposable elements in cDNA libraries obtained from pluripotent tissue suggesting a possible correlation between methylation patterns, expression of transposable element associated genes and somaclonal variation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Flow of essential elements in subcellular fractions during oxidative stress.

PubMed

Lago, Larissa; Nunes, Emilene A; Vigato, Aryane A; Souza, Vanessa C O; Barbosa, Fernando; Sato, João R; Batista, Bruno L; Cerchiaro, Giselle

2017-02-01

Essential trace elements are commonly found in altered concentrations in the brains of patients with neurodegenerative diseases. Many studies in trace metal determination and quantification are conducted in tissue, cell culture or whole brain. In the present investigation, we determined by ICP-MS Fe, Cu, Zn, Ca, Se, Co, Cr, Mg, and Mn in organelles (mitochondria, nuclei) and whole motor neuron cell cultured in vitro. We performed experiments using two ways to access oxidative stress: cell treatments with H 2 O 2 or Aβ-42 peptide in its oligomeric form. Both treatments caused accumulation of markers of oxidative stress, such as oxidized proteins and lipids, and alteration in DNA. Regarding trace elements, cells treated with H 2 O 2 showed higher levels of Zn and lower levels of Ca in nuclei when compared to control cells with no oxidative treatments. On the other hand, cells treated with Aβ-42 peptide in its oligomeric form showed higher levels of Mg, Ca, Fe and Zn in nuclei when compared to control cells. These differences showed that metal flux in cell organelles during an intrinsic external oxidative condition (H 2 O 2 treatment) are different from an intrinsic external neurodegenerative treatment.

Trace metals and macroelements in mussels from Chinese coastal waters: National spatial patterns and normalization.

PubMed

Lu, Guang-Yuan; Wang, Wen-Xiong

2018-06-01

Metal contamination is one of the most ubiquitous and complex problems in the Chinese coastal environment. To explore the large-scale spatial patterns of bioavailable metals, we sampled three major mussels, including 784 blue mussels (Mytilus edulis Linnaeus, 1758) of 14 sites, 224 hard-shelled mussels (Mytilus unguiculatus Valenciennes, 1858) of 4 sites, and 392 green mussels (Perna viridis (Linnaeus, 1758)) of 7 sites, ranging from temperate to tropical coastlines of China, during August and September 2015. The concentrations of macroelements (Na, K, Ca, Mg, and P) and toxic trace metals (Ag, Cd, Cr, Cu, Ni, Pb, Ti, and Zn) in the mussel's whole soft tissues were determined. Among the four Chinese coastal basins, Cd, Ti and Cr in the mussel tissues were the highest at Bohai Sea (BS) and Yellow Sea (YS), and Cu, Ni, Pb and Ag in the mussel tissues were the highest at East China Sea (ECS) and South China Sea (SCS). Zinc concentrations in mussels from YS were significantly higher than those from the other regions. Given the variability of environmental conditions such as salinity and nutrients, we further normalized the measured tissue metal concentrations with tissue Na and P levels. After Na normalization as the salinity proxy, the variability of Cd, Cu, Zn, Ag, and Ni was reduced. Trace elements accumulation in the mussel tissues was significantly related to both macroelements (Na or P) and body dry weight. The present study demonstrated that nonlinear optimization of different elements was necessary in assessing metal bioaccumulation patterns in marine mussels at a large spatial scale. Copyright © 2018 Elsevier B.V. All rights reserved.

An attempt to diagnose cancer by PIXE

NASA Astrophysics Data System (ADS)

Uda, M.; Maeda, K.; Sasa, Y.; Kusuyama, H.; Yokode, Y.

1987-03-01

PIXE is suitable especially for trace elemental analysis for atoms with high atomic numbers, which are contained in matrices composed mainly of light elements such as biological materials. An attempt has been made to distinguish elemental concentrations of cancer tissues from those of normal ones. Kidney, testis and urinary bladder cancer tissues were examined by PIXE. Key elements to diagnose these cancers were Ca, Ti, Cr, Fe and Zn. Enrichment of Fe and Ti, and deficiency of Zn could be seen in the kidney cancer. An opposite tendency was observed in the testicular cancer. Imbalance of these elemental concentrations in characteristic organs might give us a possibility for cancer diagnosis.

Finite Element Method (FEM), Mechanobiology and Biomimetic Scaffolds in Bone Tissue Engineering

PubMed Central

Boccaccio, A.; Ballini, A.; Pappalettere, C.; Tullo, D.; Cantore, S.; Desiate, A.

2011-01-01

Techniques of bone reconstructive surgery are largely based on conventional, non-cell-based therapies that rely on the use of durable materials from outside the patient's body. In contrast to conventional materials, bone tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences towards the development of biological substitutes that restore, maintain, or improve bone tissue function. Bone tissue engineering has led to great expectations for clinical surgery or various diseases that cannot be solved with traditional devices. For example, critical-sized defects in bone, whether induced by primary tumor resection, trauma, or selective surgery have in many cases presented insurmountable challenges to the current gold standard treatment for bone repair. The primary purpose of bone tissue engineering is to apply engineering principles to incite and promote the natural healing process of bone which does not occur in critical-sized defects. The total market for bone tissue regeneration and repair was valued at $1.1 billion in 2007 and is projected to increase to nearly $1.6 billion by 2014. Usually, temporary biomimetic scaffolds are utilized for accommodating cell growth and bone tissue genesis. The scaffold has to promote biological processes such as the production of extra-cellular matrix and vascularisation, furthermore the scaffold has to withstand the mechanical loads acting on it and to transfer them to the natural tissues located in the vicinity. The design of a scaffold for the guided regeneration of a bony tissue requires a multidisciplinary approach. Finite element method and mechanobiology can be used in an integrated approach to find the optimal parameters governing bone scaffold performance. In this paper, a review of the studies that through a combined use of finite element method and mechano-regulation algorithms described the possible patterns of tissue differentiation in biomimetic scaffolds for bone tissue engineering is given. Firstly, the generalities of the finite element method of structural analysis are outlined; second, the issues related to the generation of a finite element model of a given anatomical site or of a bone scaffold are discussed; thirdly, the principles on which mechanobiology is based, the principal theories as well as the main applications of mechano-regulation models in bone tissue engineering are described; finally, the limitations of the mechanobiological models and the future perspectives are indicated. PMID:21278921

A finite element evaluation of mechanical function for 3 distal extension partial dental prosthesis designs with a 3-dimensional nonlinear method for modeling soft tissue.

PubMed

Nakamura, Yoshinori; Kanbara, Ryo; Ochiai, Kent T; Tanaka, Yoshinobu

2014-10-01

The mechanical evaluation of the function of partial removable dental prostheses with 3-dimensional finite element modeling requires the accurate assessment and incorporation of soft tissue behavior. The differential behaviors of the residual ridge mucosa and periodontal ligament tissues have been shown to exhibit nonlinear displacement. The mathematic incorporation of known values simulating nonlinear soft tissue behavior has not been investigated previously via 3-dimensional finite element modeling evaluation to demonstrate the effect of prosthesis design on the supporting tissues. The purpose of this comparative study was to evaluate the functional differences of 3 different partial removable dental prosthesis designs with 3-dimensional finite element analysis modeling and a simulated patient model incorporating known viscoelastic, nonlinear soft tissue properties. Three different designs of distal extension removable partial dental prostheses were analyzed. The stress distributions to the supporting abutments and soft tissue displacements of the designs tested were calculated and mechanically compared. Among the 3 dental designs evaluated, the RPI prosthesis demonstrated the lowest stress concentrations on the tissue supporting the tooth abutment and also provided wide mucosa-borne areas of support, thereby demonstrating a mechanical advantage and efficacy over the other designs evaluated. The data and results obtained from this study confirmed that the functional behavior of partial dental prostheses with supporting abutments and soft tissues are consistent with the conventional theories of design and clinical experience. The validity and usefulness of this testing method for future applications and testing protocols are shown. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A Structural Finite Element Model for Lamellar Unit of Aortic Media Indicates Heterogeneous Stress Field After Collagen Recruitment

PubMed Central

Thunes, James R.; Pal, Siladitya; Fortunato, Ronald N.; Phillippi, Julie A.; Gleason, Thomas G.; Vorp, David A.; Maiti, Spandan

2016-01-01

Incorporation of collagen structural information into the study of biomechanical behavior of ascending thoracic aortic (ATA) wall tissue should provide better insight into the pathophysiology of ATA. Structurally motivated constitutive models that include fiber dispersion and recruitment can successfully capture overall mechanical response of the arterial wall tissue. However, these models cannot examine local microarchitectural features of the collagen network, such as the effect of fiber disruptions and interaction between fibrous and non-fibrous components, which may influence emergent biomechanical properties of the tissue. Motivated by this need, we developed a finite element based three-dimensional structural model of the lamellar units of the ATA media that directly incorporates the collagen fiber microarchitecture. The fiber architecture was computer generated utilizing network features, namely fiber orientation distribution, intersection density and areal concentration, obtained from image analysis of multiphoton microscopy images taken from human aneurysmal ascending thoracic aortic media specimens with bicuspid aortic valve (BAV) phenotype. Our model reproduces the typical J-shaped constitutive response of the aortic wall tissue. We found that the stress state in the non-fibrous matrix was homogeneous until the collagen fibers were recruited, but became highly heterogeneous after that event. The degree of heterogeneity was dependent upon local network architecture with high stresses observed near disrupted fibers. The magnitude of non-fibrous matrix stress at higher stretch levels was negatively correlated with local fiber density. The localized stress concentrations, elucidated by this model, may be a factor in the degenerative changes in aneurysmal ATA tissue. PMID:27113538

Lipoprotein lipase: genetics, lipid uptake, and regulation.

PubMed

Merkel, Martin; Eckel, Robert H; Goldberg, Ira J

2002-12-01

Lipoprotein lipase (LPL) regulates the plasma levels of triglyceride and HDL. Three aspects are reviewed. 1) Clinical implications of human LPL gene variations: common mutations and their effects on plasma lipids and coronary heart disease are discussed. 2) LPL actions in the nervous system, liver, and heart: the discussion focuses on LPL and tissue lipid uptake. 3) LPL gene regulation: the LPL promoter and its regulatory elements are described.

Organ distribution and food safety aspects of cadmium and lead in great scallops, Pecten maximus L., and Horse Mussels, Modiolus modiolus L., from Norwegian waters.

PubMed

Julshamn, Kaare; Duinker, Arne; Frantzen, Sylvia; Torkildsen, Lise; Maage, Amund

2008-04-01

The purpose of the study was to determine the levels and organ distribution of the potentially harmful inorganic elements cadmium and lead in great scallops and horse mussels from unpolluted Norwegian waters. The scallops far exceeded the EU-limit for cadmium in bivalves when all soft tissues were analysed. When only muscle and gonad were included, however, the level of cadmium was acceptable, because cadmium accumulated in the digestive gland with a mean of 52 mg/kg ww (wet weight). In horse mussel, lead was the most problematic element and the concentration varied from 1.4 to 6.6 mg/kg ww with a mean of 3.7 mg/kg ww, exceeding the EU limit of 1.5 mg Pb/kg. The highest concentration of lead was found in the kidney with an average of 120 mg/kg ww and with a maximum value of 240 mg/kg ww. The kidney tissue accounted for approximately 94% of the lead burden in the horse mussel. In order to consume these bivalves, only muscle and gonad of great scallops should be used for consumption and the kidney of horse mussel should be removed prior to consumption.

Dual-energy X-ray absorptiometry: analysis of pediatric fat estimate errors due to tissue hydration effects.

PubMed

Testolin, C G; Gore, R; Rivkin, T; Horlick, M; Arbo, J; Wang, Z; Chiumello, G; Heymsfield, S B

2000-12-01

Dual-energy X-ray absorptiometry (DXA) percent (%) fat estimates may be inaccurate in young children, who typically have high tissue hydration levels. This study was designed to provide a comprehensive analysis of pediatric tissue hydration effects on DXA %fat estimates. Phase 1 was experimental and included three in vitro studies to establish the physical basis of DXA %fat-estimation models. Phase 2 extended phase 1 models and consisted of theoretical calculations to estimate the %fat errors emanating from previously reported pediatric hydration effects. Phase 1 experiments supported the two-compartment DXA soft tissue model and established that pixel ratio of low to high energy (R values) are a predictable function of tissue elemental content. In phase 2, modeling of reference body composition values from birth to age 120 mo revealed that %fat errors will arise if a "constant" adult lean soft tissue R value is applied to the pediatric population; the maximum %fat error, approximately 0.8%, would be present at birth. High tissue hydration, as observed in infants and young children, leads to errors in DXA %fat estimates. The magnitude of these errors based on theoretical calculations is small and may not be of clinical or research significance.

A constrained modulus reconstruction technique for breast cancer assessment.

PubMed

Samani, A; Bishop, J; Plewes, D B

2001-09-01

A reconstruction technique for breast tissue elasticity modulus is described. This technique assumes that the geometry of normal and suspicious tissues is available from a contrast-enhanced magnetic resonance image. Furthermore, it is assumed that the modulus is constant throughout each tissue volume. The technique, which uses quasi-static strain data, is iterative where each iteration involves modulus updating followed by stress calculation. Breast mechanical stimulation is assumed to be done by two compressional rigid plates. As a result, stress is calculated using the finite element method based on the well-controlled boundary conditions of the compression plates. Using the calculated stress and the measured strain, modulus updating is done element-by-element based on Hooke's law. Breast tissue modulus reconstruction using simulated data and phantom modulus reconstruction using experimental data indicate that the technique is robust.

Modulation of hepatocyte growth factor gene expression by estrogen in mouse ovary.

PubMed

Liu, Y; Lin, L; Zarnegar, R

1994-09-01

Hepatocyte growth factor (HGF) is expressed in a variety of tissues and cell types under normal conditions and in response to various stimuli such as tissue injury. In the present study, we demonstrate that the transcription of the HGF gene is stimulated by estrogen in mouse ovary. A single injection of 17 beta-estradiol results in a dramatic and transient elevation of the levels of mouse HGF mRNA. Sequence analysis has found that two putative estrogen responsive elements (ERE) reside at -872 in the 5'-flanking region and at +511 in the first intron, respectively, of the mouse HGF gene. To test whether these ERE elements are responsible for estrogen induction of HGF gene expression, chimeric plasmids containing variable regions of the 5'-flanking sequence of HGF gene and the coding region for chloramphenicol acetyltransferase (CAT) gene were transiently transfected into both human endometrial carcinoma RL 95-2 cells and mouse fibroblast NIH 3T3 cells to assess hormone responsiveness. Transfection results indicate that the ERE elements of the mouse HGF gene can confer estrogen action to either homologous or heterologous promoters. Nuclear protein extracts either from RL95-2 cells transfected with the estrogen receptor expression vector or from mouse liver bound in vitro to ERE elements specifically, as shown by band shift assay. Therefore, our results demonstrate that the HGF gene is transcriptionally regulated by estrogen in mouse ovary; and such regulation is mediated via a direct interaction of the estrogen receptor complex with cis-acting ERE elements identified in the mouse HGF gene.

Organochlorine compounds and trace elements in fish tissue and streambed sediment in the Mobile River Basin, Alabama, Mississippi, and Georgia, 1998

USGS Publications Warehouse

Zappia, Humbert

2002-01-01

During the summer of 1998, as part of the National Water-Quality Assessment Program, a survey was conducted to determine which organochlorine compounds and trace elements occur in fish tissues and streambed sediments in the Mobile River Basin, which includes parts of Alabama, Mississippi, Georgia, and Tennessee. The data collected were compared to guidelines related to wildlife, land use, and to 1991 and 1994 National Water-Quality Assessment Program Study-Unit data.Twenty-one sites were sampled in subbasins of the Mobile River Basin. The subbasins ranged in size from about 9 to 22,000 square miles and were dominated by either a single land use or a combination of land uses. The major land-use categories were urban, agriculture, and forest.Organochlorine compounds were widespread spatially in the Mobile River Basin. At least one organochlorine compound was reported at the majority of sampling sites (84 percent) and in a majority of whole-fish (80 percent) and streambed-sediment (52 percent) samples. Multiple organochlorine compounds were reported at 75 percent of the sites where fish tissues were collected and were reported at many of the streambed-sediment sampling sites (45 percent). The majority of concentrations reported, however, were less than 5 micrograms per kilogram in fish-tissue samples and less than 1 microgram per kilogram in streambed-sediment samples.The majority of trace elements analyzed in fish-liver tissue (86 percent) and streambed-sediment (98 percent) samples were reported during this study. Multiple trace elements were reported in all samples and at all sites.Based on comparisons of concentrations of organochlorine compounds and trace elements in fish-tissue and streambed-sediment samples in relation to National Academy of Science and National Academy of Engineering and Canadian tissue guidelines, probable-effects concentrations, and mean probable-effects concentration quotients for streambed sediment, the potential exists for adverse effects to wildlife at 15 (72 percent) of the sites sampled. The potential for adverse effects at these sites is because of the presence of residues or breakdown products related to polychlorinated biphenyls (PCB?s), chlordane, dichlorodiphenyltrichloroethane (DDT), chromium, lead, and zinc.The majority of compounds reported (65 percent) were chlordane, DDT, and PCB?s, or their breakdown products. Concentrations of chlordane and heptachlor epoxide in whole-fish tissue were positively correlated to the amount of urban land use in a basin. Total DDT concentrations in whole-fish tissues were positively correlated to agriculture.The relation of trace elements to land use is not as clear as the relation of organochlorine compounds to land use. This lack of clarity may be due to the possibility of geologic sources of trace elements in the Mobile River Basin and to the ubiquitous nature of many of these trace elements. However, there may be a correlation between the amount of urban land use and concentrations of antimony, cadmium, lead, and zinc in streambed-sediment samples from the Mobile River Basin.Fewer organochlorine compounds and trace elements were reported in samples from the Mobile River Basin than in samples collected during the 1991 and 1994 National Water-Quality Assessment Program studies. Of the organochlorine compounds analyzed nationally, 57 percent were reported in whole-fish tissue samples collected locally and 41 percent were reported in streambed-sediment samples collected locally, whereas 96 percent and 86 percent, respectively, were reported nationally. Of trace elements analyzed nationally, 86 percent were reported in fish-liver tissue locally and 95 percent were reported in streambed-sediment samples locally, whereas 95 percent and 98 percent, respectively, were reported nationally.In general, concentrations of organochlorine compounds and trace elements and the frequency with which they were reported in the Mobile River Basin are similar to or less than t

Contents of chemical elements in stomach during prenatal development: different age-dependent dynamical changes and their significance

PubMed Central

Hou, Shao-Fan; Li, Hai-Rong; Wang, Li-Zhen; Li, De-Zhu; Yang, Lin-Sheng; Li, Chong-Zheng

2003-01-01

AIM: To observe dynamic of different chemical elements in stomach tissue during fetal development. METHODS: To determine contents of the 21 chemical elements in each stomach samples from fetus aging four to ten months. The content values were compared to those from adult tissue samples, and the values for each month group were also analyzed for dynamic changes. RESULTS: Three representations were found regarding the relationship between contents of the elements and ages of the fetus, including the positive correlative (K), reversely correlative (Na, Ca, P, Al, Cu, Zn, Fe, Mn, Cr, Sr, Li, Cd, Ba, Se) and irrelevant groups (Mg, Co, Ni, V, Pb, Ti). CONCLUSION: The chemical elements’ contents in stomach tissues were found to change dynamically with the stomach weights. The age-dependent representations for different chemical elements during the prenatal development may be of some significance for assessing development of fetal stomach and some chemical elements. The data may be helpful for the nutritional balance of fetus and mothers during prenatal development and even the perinatal stages. PMID:12717857

Discrimination of trait-based characteristics by trace element bioaccumulation in riverine fishes

USGS Publications Warehouse

Short, T.M.; DeWeese, L.R.; Dubrovsky, N.M.

2008-01-01

Relations between tissue trace element concentrations and species traits were examined for 45 fish species to determine the extent to which trait-based characteristics accounted for relative differences among species in trace element bioaccumulation. Percentages of fish species correctly classified by discriminant analysis according to traits predicted by tissue trace element concentrations ranged from 72% to 87%. Tissue concentrations of copper, mercury, selenium, and zinc appeared to have the greatest overall influence on differentiating species according to trait characteristics. Discrimination of trait characteristics did not appear to be strongly influenced by local sources of trace elements in the streambed sediment. Bioaccumulation was greatest for those species classified as primarily detritivores, having relatively large adult body size, considered nonmigratory with respect to reproductive strategy, occurring mostly in large or variable size streams and rivers, preferring depositional areas within the stream channel, and preferring benthic rather than open-water habitats. Our findings provide evidence of the strong relationship between bioaccumulation of environmental trace elements and trait-based factors that influence contaminant exposure. ?? 2008 NRC.

Immunocytolocalization of extensin in developing soybean seed coats by immunogold-silver staining and by tissue printing on nitrocellulose paper

PubMed Central

1987-01-01

In soybean seed coats the accumulation of the hydroxyproline-rich glycoprotein extensin is regulated in a developmental and tissue- specific manner. The time course of appearance of extensin during seed development was studied by Western blot analysis and by immunogold- silver localization. Using these techniques extensin was first detected at 16-18 d after anthesis, increasing during development to high levels at 24 d after anthesis. Immunogold-silver localization of extensin in the seed coat showed marked deposition of the glycoprotein in the walls of palisade epidermal cells and hourglass cells. The immunolocalization of extensin in developing soybean seeds was also made by a new technique--tissue printing on nitrocellulose paper. It was found that extensin is primarily localized in the seed coat, hilum, and vascular elements of the seed. PMID:3693394

Effect of framework material and vertical misfit on stress distribution in implant-supported partial prosthesis under load application: 3-D finite element analysis.

PubMed

Bacchi, Ataís; Consani, Rafael Leonardo Xediek; Mesquita, Marcelo Ferraz; Dos Santos, Mateus Bertolini Fernandes

2013-09-01

This study evaluated the influence of framework material and vertical misfit on stress created in an implant-supported partial prosthesis under load application. The posterior part of a severely reabsorbed jaw with a fixed partial prosthesis above two osseointegrated titanium implants at the place of the second premolar and second molar was modeled using SolidWorks 2010 software. Finite element models were obtained by importing the solid model into an ANSYS Workbench 11 simulation. The models were divided into 15 groups according to their prosthetic framework material (type IV gold alloy, silver-palladium alloy, commercially pure titanium, cobalt-chromium alloy or zirconia) and vertical misfit level (10 µm, 50 µm and 100 µm). After settlement of the prosthesis with the closure of the misfit, simultaneous loads of 110 N vertical and 15 N horizontal were applied on the occlusal and lingual faces of each tooth, respectively. The data was evaluated using Maximum Principal Stress (framework, porcelain veneer and bone tissue) and a von Mises Stress (retention screw) provided by the software. As a result, stiffer frameworks presented higher stress concentrations; however, these frameworks led to lower stresses in the porcelain veneer, the retention screw (faced to 10 µm and 50 µm of the misfit) and the peri-implant bone tissues. The increase in the vertical misfit resulted in stress values increasing in all of the prosthetic structures and peri-implant bone tissues. The framework material and vertical misfit level presented a relevant influence on the stresses for all of the structures evaluated.

Mapping local orientation of aligned fibrous scatterers for cancerous tissues using backscattering Mueller matrix imaging

NASA Astrophysics Data System (ADS)

He, Honghui; Sun, Minghao; Zeng, Nan; Du, E.; Liu, Shaoxiong; Guo, Yihong; Wu, Jian; He, Yonghong; Ma, Hui

2014-10-01

Polarization measurements are sensitive to the microstructure of tissues and can be used to detect pathological changes. Many tissues contain anisotropic fibrous structures. We obtain the local orientation of aligned fibrous scatterers using different groups of the backscattering Mueller matrix elements. Experiments on concentrically well-aligned silk fibers and unstained human papillary thyroid carcinoma tissues show that the m22, m33, m23, and m32 elements have better contrast but higher degeneracy for the extraction of orientation angles. The m12 and m13 elements show lower contrast, but allow us to determine the orientation angle for the fibrous scatterers along all directions. Moreover, Monte Carlo simulations based on the sphere-cylinder scattering model indicate that the oblique incidence of the illumination beam introduces some errors in the orientation angles obtained by both methods. Mapping the local orientation of anisotropic tissues may not only provide information on pathological changes, but can also give new leads to reduce the orientation dependence of polarization measurements.

Abscisic acid and stress signals induce Viviparous1 expression in seed and vegetative tissues of maize.

PubMed

Cao, Xueyuan; Costa, Liliana M; Biderre-Petit, Corinne; Kbhaya, Bouchab; Dey, Nrisingha; Perez, Pascual; McCarty, Donald R; Gutierrez-Marcos, Jose F; Becraft, Philip W

2007-02-01

Viviparous1 (Vp1) encodes a B3 domain-containing transcription factor that is a key regulator of seed maturation in maize (Zea mays). However, the mechanisms of Vp1 regulation are not well understood. To examine physiological factors that may regulate Vp1 expression, transcript levels were monitored in maturing embryos placed in culture under different conditions. Expression of Vp1 decreased after culture in hormone-free medium, but was induced by salinity or osmotic stress. Application of exogenous abscisic acid (ABA) also induced transcript levels within 1 h in a dose-dependent manner. The Vp1 promoter fused to beta-glucuronidase or green fluorescent protein reproduced the endogenous Vp1 expression patterns in transgenic maize plants and also revealed previously unknown expression domains of Vp1. The Vp1 promoter is active in the embryo and aleurone cells of developing seeds and, upon drought stress, was also found in phloem cells of vegetative tissues, including cobs, leaves, and stems. Sequence analysis of the Vp1 promoter identified a potential ABA-responsive complex, consisting of an ACGT-containing ABA response element (ABRE) and a coupling element 1-like motif. Electrophoretic mobility shift assay confirmed that the ABRE and putative coupling element 1 components specifically bound proteins in embryo nuclear protein extracts. Treatment of embryos in hormone-free Murashige and Skoog medium blocked the ABRE-protein interaction, whereas exogenous ABA or mannitol treatment restored this interaction. Our data support a model for a VP1-dependent positive feedback mechanism regulating Vp1 expression during seed maturation.

Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent

PubMed Central

Borell, Esther M.; Fine, Maoz; Shaked, Yeala

2014-01-01

Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments—the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone’s tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis regulates its internal trace element concentrations by compartmentalization and excretion and that these features contribute to its resilience and potential success at the trace element-rich high pCO2 vent. PMID:25250210

Correlation between CT numbers and tissue parameters needed for Monte Carlo simulations of clinical dose distributions

NASA Astrophysics Data System (ADS)

Schneider, Wilfried; Bortfeld, Thomas; Schlegel, Wolfgang

2000-02-01

We describe a new method to convert CT numbers into mass density and elemental weights of tissues required as input for dose calculations with Monte Carlo codes such as EGS4. As a first step, we calculate the CT numbers for 71 human tissues. To reduce the effort for the necessary fits of the CT numbers to mass density and elemental weights, we establish four sections on the CT number scale, each confined by selected tissues. Within each section, the mass density and elemental weights of the selected tissues are interpolated. For this purpose, functional relationships between the CT number and each of the tissue parameters, valid for media which are composed of only two components in varying proportions, are derived. Compared with conventional data fits, no loss of accuracy is accepted when using the interpolation functions. Assuming plausible values for the deviations of calculated and measured CT numbers, the mass density can be determined with an accuracy better than 0.04 g cm-3 . The weights of phosphorus and calcium can be determined with maximum uncertainties of 1 or 2.3 percentage points (pp) respectively. Similar values can be achieved for hydrogen (0.8 pp) and nitrogen (3 pp). For carbon and oxygen weights, errors up to 14 pp can occur. The influence of the elemental weights on the results of Monte Carlo dose calculations is investigated and discussed.

Using FAIRE (Formaldehyde-Assisted Isolation of Regulatory Elements) to isolate active regulatory DNA

PubMed Central

Simon, Jeremy M.; Giresi, Paul G.; Davis, Ian J.; Lieb, Jason D.

2013-01-01

Eviction or destabilization of nucleosomes from chromatin is a hallmark of functional regulatory elements of the eukaryotic genome. Historically identified by nuclease hypersensitivity, these regulatory elements are typically bound by transcription factors or other regulatory proteins. FAIRE (Formaldehyde-Assisted Isolation of Regulatory Elements) is an alternative approach to identify these genomic regions and has proven successful in a multitude of eukaryotic cell and tissue types. Cells or dissociated tissues are crosslinked briefly with formaldehyde, lysed, and sonicated. Sheared chromatin is subjected to phenol-chloroform extraction and the isolated DNA, typically encompassing 1–3% of the human genome, is purified. We provide guidelines for quantitative analysis by PCR, microarrays, or next-generation sequencing. Regulatory elements enriched by FAIRE display high concordance with those identified by nuclease hypersensitivity or ChIP, and the entire procedure can be completed in three days. FAIRE exhibits low technical variability, which allows its use in large-scale studies of chromatin from normal or diseased tissues. PMID:22262007

Extended Finite Element Method with Simplified Spherical Harmonics Approximation for the Forward Model of Optical Molecular Imaging

PubMed Central

Li, Wei; Yi, Huangjian; Zhang, Qitan; Chen, Duofang; Liang, Jimin

2012-01-01

An extended finite element method (XFEM) for the forward model of 3D optical molecular imaging is developed with simplified spherical harmonics approximation (SPN). In XFEM scheme of SPN equations, the signed distance function is employed to accurately represent the internal tissue boundary, and then it is used to construct the enriched basis function of the finite element scheme. Therefore, the finite element calculation can be carried out without the time-consuming internal boundary mesh generation. Moreover, the required overly fine mesh conforming to the complex tissue boundary which leads to excess time cost can be avoided. XFEM conveniences its application to tissues with complex internal structure and improves the computational efficiency. Phantom and digital mouse experiments were carried out to validate the efficiency of the proposed method. Compared with standard finite element method and classical Monte Carlo (MC) method, the validation results show the merits and potential of the XFEM for optical imaging. PMID:23227108

Extended finite element method with simplified spherical harmonics approximation for the forward model of optical molecular imaging.

PubMed

Li, Wei; Yi, Huangjian; Zhang, Qitan; Chen, Duofang; Liang, Jimin

2012-01-01

An extended finite element method (XFEM) for the forward model of 3D optical molecular imaging is developed with simplified spherical harmonics approximation (SP(N)). In XFEM scheme of SP(N) equations, the signed distance function is employed to accurately represent the internal tissue boundary, and then it is used to construct the enriched basis function of the finite element scheme. Therefore, the finite element calculation can be carried out without the time-consuming internal boundary mesh generation. Moreover, the required overly fine mesh conforming to the complex tissue boundary which leads to excess time cost can be avoided. XFEM conveniences its application to tissues with complex internal structure and improves the computational efficiency. Phantom and digital mouse experiments were carried out to validate the efficiency of the proposed method. Compared with standard finite element method and classical Monte Carlo (MC) method, the validation results show the merits and potential of the XFEM for optical imaging.

Improving finite element results in modeling heart valve mechanics.

PubMed

Earl, Emily; Mohammadi, Hadi

2018-06-01

Finite element analysis is a well-established computational tool which can be used for the analysis of soft tissue mechanics. Due to the structural complexity of the leaflet tissue of the heart valve, the currently available finite element models do not adequately represent the leaflet tissue. A method of addressing this issue is to implement computationally expensive finite element models, characterized by precise constitutive models including high-order and high-density mesh techniques. In this study, we introduce a novel numerical technique that enhances the results obtained from coarse mesh finite element models to provide accuracy comparable to that of fine mesh finite element models while maintaining a relatively low computational cost. Introduced in this study is a method by which the computational expense required to solve linear and nonlinear constitutive models, commonly used in heart valve mechanics simulations, is reduced while continuing to account for large and infinitesimal deformations. This continuum model is developed based on the least square algorithm procedure coupled with the finite difference method adhering to the assumption that the components of the strain tensor are available at all nodes of the finite element mesh model. The suggested numerical technique is easy to implement, practically efficient, and requires less computational time compared to currently available commercial finite element packages such as ANSYS and/or ABAQUS.

Tissue-Specific Regulation of the Contents and Correlations of Mineral Elements in Hens by Zinc Oxide Nanoparticles.

PubMed

Zhao, Yong; Feng, Yan-Ni; Li, Lan; Zhang, Hong-Fu; Zhang, Yu-Na; Zhang, Peng-Fei; Liu, Xin-Qi; Zhang, Wei-Dong; Huang, Ting-Ting; Zhao, Li; Shen, Wei; Hao, Zhi-Hui

2017-06-01

Due to their small size, zinc oxide (ZnO) nanoparticles (NPs) are readily absorbed and easily cross biological barriers, which make them promising candidates as diet additives. However, some studies have reported that ZnO NPs cause toxicity; therefore, their safety and potency as diet additives for farm animals should be established. This study was the first to fully evaluate the effects of ZnO NPs on the homeostasis of eight elements in seven organs/tissues. The regulation of element homeostasis was found to be organ specific with no influence on oxidation status, anti-oxidation capability, or organ damage. ZnO NPs may specifically regulate the homeostasis of mineral elements and affect the following correlations: (1) between the element content in each organ and the concentration of Zn used in ZnSO 4 or ZnO NP treatments; (2) between ZnO NP and ZnSO 4 treatments for the same element in each organ; and (3) between elements (in each organ in ZnSO 4 or ZnO NP treatments) in layers' organs/tissues. The use of ZnO NPs as diet additives for animals should be implemented cautiously because, among other uncertainties, they may affect mineral element content.

PIXE analysis of elements in gastric cancer and adjacent mucosa

NASA Astrophysics Data System (ADS)

Liu, Qixin; Zhong, Ming; Zhang, Xiaofeng; Yan, Lingnuo; Xu, Yongling; Ye, Simao

1990-04-01

The elemental regional distributions in 20 resected human stomach tissues were obtained using PIXE analysis. The samples were pathologically divided into four types: normal, adjacent mucosa A, adjacent mucosa B and cancer. The targets for PIXE analysis were prepared by wet digestion with a pressure bomb system. P, K, Fe, Cu, Zn and Se were measured and statistically analysed. We found significantly higher concentrations of P, K, Cu, Zn and a higher ratio of Cu compared to Zn in cancer tissue as compared with normal tissue, but statistically no significant difference between adjacent mucosa and cancer tissue was found.

Trace elements and organic compounds in streambed sediment and aquatic biota from the Sacramento River Basin, California, October and November 1995

USGS Publications Warehouse

MacCoy, Dorene E.; Domagalski, Joseph L.

1999-01-01

Elevated levels of trace elements and hydrophobic organic compounds were detected in streambed sediments and aquatic biota [Asiatic clam (Corbicula fluminea) or bottom-feeding fish] of the Sacramento River Basin, California, during October and November 1995. Trace elements detected included cadmium, copper, mercury, lead, and zinc. Elevated levels of cadmium, copper, and zinc in the upper Sacramento River are attributed to a mining land use, and elevated levels of zinc and lead in an urban stream, and possibly in the lower Sacramento River, are attributed to urban runoff processes. Elevated levels of mercury in streambed sediment are attributed to either past mercury mining or to the use of mercury in past gold mining operations. Mercury mining was an important land use within the Coast Ranges in the past and gold mining was an important land use of the Sierra Nevada in the past. Mercury was the only trace element found in elevated levels in the tissue of aquatic biota, and those levels also could be attributed to either mining or urban runoff. Hydrophobic organic compounds also were detected in streambed sediments and aquatic biota. The most frequently detected compounds were DDT and its breakdown products, dieldrin, oxychlordane, and toxaphene. Differences were found in the types of compounds detected at agricultural sites and the urban site. Although both types of sites had measurable concentrations of DDT or its breakdown products, the urban site also had measurable concentrations of pesticides used for household pest control. Few semivolatile compounds were detected in the streambed sediments of any site. The semivolatile compound p-cresol, a coal-tar derivative associated with road maintenance, was found in the highest concentration.

Trace elements in early phase type 2 diabetes mellitus-A population-based study. The HUNT study in Norway.

PubMed

Hansen, Ailin Falkmo; Simić, Anica; Åsvold, Bjørn Olav; Romundstad, Pål Richard; Midthjell, Kristian; Syversen, Tore; Flaten, Trond Peder

2017-03-01

Differences in trace elements levels between individuals with type 2 diabetes and controls have been reported in several studies in various body fluids and tissues, but results have been inconsistent. In order to examine trace element levels in the early phase of type 2 diabetes, we investigated the association between whole blood levels of 26 trace elements and the prevalence of previously undiagnosed, screening-detected type 2 diabetes. The study was conducted as a case-control study nested within the third survey of the population-based Nord-Trøndelag Health Study (HUNT3 Survey). Among participants without previously known diabetes, 128 cases of type 2 diabetes were diagnosed in people with a high diabetes risk score (FINDRISC≥15), and frequency-matched for age and sex with 755 controls. Blood samples were analyzed by high resolution inductively coupled plasma mass spectrometry. Associations between trace element levels and the prevalence of previously undiagnosed type 2 diabetes were evaluated with multivariable conditional logistic regression controlling for age, sex, body mass index, waist-to-hip ratio, education, income, smoking and family history of diabetes. The prevalence of previously undiagnosed type 2 diabetes increased across tertiles/quartiles for cadmium, chromium, iron, nickel, silver and zinc, and decreased with increasing quartiles of bromine (P trend <0.05). After corrections for multiple testing, associations for chromium remained significant (Q trend <0.05), while associations for iron and silver were borderline significant. No associations were found for arsenic, boron, calcium, cesium, copper, gallium, gold, indium, lead, magnesium, manganese, mercury, molybdenum, rubidium, selenium, strontium, tantalum, thallium and tin. Our results suggest a possible role of bromine, cadmium, chromium, iron, nickel, silver and zinc in the development of type 2 diabetes. Copyright © 2016 Elsevier GmbH. All rights reserved.

Certification of the methylmercury content in SRM 2977 mussel tissue (organic contaminants and trace elements) and SRM 1566b oyster tissue.

PubMed

Tutschku, S; Schantz, M M; Horvat, M; Logar, M; Akagi, H; Emons, H; Levenson, M; Wise, S A

2001-02-01

The methylmercury content in two new marine bivalve mollusk tissue Standard Reference Materials (SRMs) has been certified using results of analyses from the National Institute of Standards and Technology (NIST) and two other laboratories. The certified concentrations of methylmercury were established based on the results from four and six different (independent) analytical methods, respectively, for SRM 1566b Oyster Tissue (13.2 +/- 0.7 microg/kg) and SRM 2977 Mussel Tissue (organic contaminants and trace elements) (36.2 +/- 1.7 microg/kg). The certified concentration of methylmercury in SRM 1566b is among the lowest in any certified reference material (CRM).

Novel mechanism of regulation of fibrosis in kidney tumor with tuberous sclerosis

PubMed Central

2013-01-01

Background Deficiency in tuberin results in activation the mTOR pathway and leads to accumulation of cell matrix proteins. The mechanisms by which tuberin regulates fibrosis in kidney angiomyolipomas (AMLs) of tuberous sclerosis patients are not fully known. Method In the present study, we investigated the potential role of tuberin/mTOR pathway in the regulation of cell fibrosis in AML cells and kidney tumor tissue from tuberous sclerosis complex (TSC) patients. Results AML cells treated with rapamycin shows a significant decrease in mRNA and protein expression as well as in promoter transcriptional activity of alpha-smooth muscle actin (α-SMA) compared to untreated cells. In addition, cells treated with rapamycin significantly decreased the protein expression of the transcription factor YY1. Rapamycin treatment also results in the redistribution of YY1 from the nucleus to cytoplasm in AML cells. Moreover, cells treated with rapamycin resulted in a significant reduce of binding of YY1 to the αSMA promoter element in nuclear extracts of AML cells. Kidney angiomyolipoma tissues from TSC patients showed lower levels of tuberin and higher levels of phospho-p70S6K that resulted in higher levels of mRNA and protein of αSMA expression compared to control kidney tissues. In addition, most of the α-SMA staining was identified in the smooth muscle cells of AML tissues. YY1 was also significantly increased in tumor tissue of AMLs compared to control kidney tissue suggesting that YY1 plays a major role in the regulation of αSMA. Conclusions These data comprise the first report to provide one mechanism whereby rapamycin might inhibit the cell fibrosis in kidney tumor of TSC patients. PMID:23705901

The accumulation of elements in plants growing spontaneously on small heaps left by the historical Zn-Pb ore mining.

PubMed

Stefanowicz, Anna M; Stanek, Małgorzata; Woch, Marcin W; Kapusta, Paweł

2016-04-01

The study evaluated the levels of nine metals, namely Ca, Cd, Fe, K, Mg, Mn, Pb, Tl, and Zn, in soils and tissues of ten plant species growing spontaneously on heaps left by historical mining for Zn-Pb ores. The concentrations of Cd, Pb, Tl, and Zn in heap soils were much higher than in control soils. Plants growing on heaps accumulated excessive amounts of these elements in tissues, on average 1.3-52 mg Cd kg(-1), 9.4-254 mg Pb kg(-1), 0.06-23 mg Tl kg(-1) and 134-1479 mg Zn kg(-1) in comparison to 0.5-1.1 mg Cd kg(-1), 2.1-11 mg Pb kg(-1), 0.02-0.06 mg Tl kg(-1), and 23-124 mg Zn kg(-1) in control plants. The highest concentrations of Cd, Pb, and Zn were found in the roots of Euphorbia cyparissias, Fragaria vesca, and Potentilla arenaria, and Tl in Plantago lanceolata. Many species growing on heaps were enriched in K and Mg, and depleted in Ca, Fe, and Mn. The concentrations of all elements in plant tissues were dependent on species, organ (root vs. shoot), and species-organ interactions. Average concentrations of Ca, K, and Mg were generally higher in shoots than in roots or similar in the two organs, whereas Cd, Fe, Pb, Tl, and Zn were accumulated predominantly in the roots. Our results imply that heaps left by historical mining for Zn-Pb ores may pose a potential threat to the environment and human health.

Evolution of Nova-Dependent Splicing Regulation in the Brain

PubMed Central

Živin, Marko; Darnell, Robert B

2007-01-01

A large number of alternative exons are spliced with tissue-specific patterns, but little is known about how such patterns have evolved. Here, we study the conservation of the neuron-specific splicing factors Nova1 and Nova2 and of the alternatively spliced exons they regulate in mouse brain. Whereas Nova RNA binding domains are 94% identical across vertebrate species, Nova-dependent splicing silencer and enhancer elements (YCAY clusters) show much greater divergence, as less than 50% of mouse YCAY clusters are conserved at orthologous positions in the zebrafish genome. To study the relation between the evolution of tissue-specific splicing and YCAY clusters, we compared the brain-specific splicing of Nova-regulated exons in zebrafish, chicken, and mouse. The presence of YCAY clusters in lower vertebrates invariably predicted conservation of brain-specific splicing across species, whereas their absence in lower vertebrates correlated with a loss of alternative splicing. We hypothesize that evolution of Nova-regulated splicing in higher vertebrates proceeds mainly through changes in cis-acting elements, that tissue-specific splicing might in some cases evolve in a single step corresponding to evolution of a YCAY cluster, and that the conservation level of YCAY clusters relates to the functions encoded by the regulated RNAs. PMID:17937501

Placental Hypomethylation Is More Pronounced in Genomic Loci Devoid of Retroelements

PubMed Central

Chatterjee, Aniruddha; Macaulay, Erin C.; Rodger, Euan J.; Stockwell, Peter A.; Parry, Matthew F.; Roberts, Hester E.; Slatter, Tania L.; Hung, Noelyn A.; Devenish, Celia J.; Morison, Ian M.

2016-01-01

The human placenta is hypomethylated compared to somatic tissues. However, the degree and specificity of placental hypomethylation across the genome is unclear. We assessed genome-wide methylation of the human placenta and compared it to that of the neutrophil, a representative homogeneous somatic cell. We observed global hypomethylation in placenta (relative reduction of 22%) compared to neutrophils. Placental hypomethylation was pronounced in intergenic regions and gene bodies, while the unmethylated state of the promoter remained conserved in both tissues. For every class of repeat elements, the placenta showed lower methylation but the degree of hypomethylation differed substantially between these classes. However, some retroelements, especially the evolutionarily younger Alu elements, retained high levels of placental methylation. Surprisingly, nonretrotransposon-containing sequences showed a greater degree of placental hypomethylation than retrotransposons in every genomic element (intergenic, introns, and exons) except promoters. The differentially methylated fragments (DMFs) in placenta and neutrophils were enriched in gene-poor and CpG-poor regions. The placentally hypomethylated DMFs were enriched in genomic regions that are usually inactive, whereas hypermethylated DMFs were enriched in active regions. Hypomethylation of the human placenta is not specific to retroelements, indicating that the evolutionary advantages of placental hypomethylation go beyond those provided by expression of retrotransposons and retrogenes. PMID:27172225

210Po Activity and concentrations of selected trace elements (As, Cd, Cu, Hg, Pb, Zn) in the muscle tissue of tunas Thunnus albacares and Katsuwonus pelamis from the Eastern Pacific Ocean.

PubMed

Ruelas-Inzunza, Jorge; Soto-Jiménez, Martín Federico; Ruiz-Fernández, Ana Carolina; Bojórquez-Leyva, Humberto; Pérez-Bernal, Hascibe; Páez-Osuna, Federico

2012-12-01

Daily mineral intake (DMI) of Cu and Zn, percentage weekly intake (PWI) of As, Cd, Hg, Pb, and doses of (210)Po were estimated by using their elemental concentration in muscle of two tuna species and the average tuna consumption in Mexico. Skipjack tuna Katsuwonus pelamis had significantly (p < 0.05) higher levels of As (1.38 μg g(-1) dw) and Cu (1.85 μg g(-1) dw) than yellowfin tuna Thunnus albacares, whereas Pb concentrations (0.18 μg g(-1) dw) were significantly (p < 0.05) higher in T. albacares. The sequence of elemental concentrations in both species was Zn > Cu > As > Hg > Pb > Cd. In T. albacares, concentrations of Cd and Pb in muscle tissue were positively correlated (p < 0.05) with weight of specimens, while Cu was negatively correlated. DMI values were below 10 %. PWI figures (<2 %) are not potentially harmful to human health. (210)Po concentration in T. albacares and K. pelamis accounts for 13.5 to 89.7 % of the median individual annual dose (7.1 μSv) from consumption of marine fish and shellfish for the world population.

CFTR expression and organ damage in cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tizzano, E.; Chitayat, D.; Buchwald, M.

1994-09-01

To assist our understanding of the origin of organ damage caused by cystic fibrosis (CF) disease, we have analyzed the pattern of expression of the CF gene (CFTR). mRNA in situ hybridization analysis was carried out in human fetal, newborn, infant and adult tissues and the abundance of the mRNA was correlated with the known pathology at the various stages of human development. Analysis of the pattern of expression indicates a constitutive level of mRNA in gastrointestinal tissues starting during early development and maintained throughout life. Prenatal respiratory tissues show qualitative and quantitative major differences in comparison to postnatal lungmore » samples. Male reproductive tissues show high levels of expression in the head of the epididymis compared with the rest of the male ducts. Female reproductive tissues show a variable pattern of expression at different stages during fetal development and during puberty probably due to changes in hormonal levels. Gastrointestinal and male reproductive tissues have a consistent pathology at birth, whereas no lung abnormalities have been described in newborns affected by CF. Our results show that there is no exact correlations between organ damage present at birth and the degree of CFTR expression. To explain these observations, we hypothesize that the pathogenesis of organ damage in CF depend on at least three factors: the rate of CFTR-mediated fluid secretion, differences in genotype and environmental factors, such as the amount of macromolecules in the lumen of the ducts. This last element predicts that damage will occur in tissues with high protein loads and low flow rates (e.g. pancreas, epididymis), where the absence of CFTR function leads to obstruction and pathology. Organs that express CFTR but with no significant damage (e.g. prenatal lung, female reproductive tissues), will have a low protein load and a high flow rates.« less

Chemical element concentrations in four lichens on a transect entering Voyageurs National Park

USGS Publications Warehouse

Bennett, J.; Wetmore, C.M.

1997-01-01

A three factor transect study was conducted to test the hypothesis that chemical elements from air emissions in the vicinity of International Falls, Minnesota could not be detected in lichens along a 24 km transect reaching into Voyageurs National Park. It was hypothesized that element concentrations in lichens would decline exponentially downwind and would reach background values at a distance before the park boundary. Four species (Cladina rangiferina, Evernia mesomorpha, Hypogymnia physodes, and Parmelia sulcata) were sampled at ten sites for 3 years and 17 chemical elements were measured. The most notable result was a curvilinear geographic trend for many elements, which decreased from International Falls and then increased towards the park. This trend was significant for many anthropogenic elements, including S, Hg, Cd, and Cr, and for all four species. This type of distribution pattern has been observed in Hypogymnia physodes in other studies downwind of a steel mill and an oil refinery. Cladina, a ground-dwelling lichen, generally had lower tissue concentrations of the elements than the three epiphytic species. Tissue concentrations over the 3 years of sampling declined an average of 12%. Sufficient evidence exists to conclude that lichen tissue element concentrations in the vicinity of International Falls may be related to local air emissions, and that an exponential decline of element concentrations downwind of the sources does not apply to this situation.

Contribution of Spaceflight Environmental Factors to Vision Risks

NASA Technical Reports Server (NTRS)

Zanello, Susana

2012-01-01

The recognition of a risk of visual impairment and intracranial pressure increase as a result of spaceflight has directed our attention and research efforts to the eye. While the alterations observed in astronauts returning from long duration missions include reportable vision and neuroanatomical changes observed by non-invasive methods, other effects and subsequent tissue responses at the molecular and cellular level can only be studied by accessing the tissue itself. As a result of this need, several studies are currently taking place that use animal models for eye research within the HHC Element. The implementation of these studies represents a significant addition to the capabilities of the biomedical research laboratories within the SK3 branch at JSC.

Multimodal imaging of vocal fold scarring in a rabbit model by multiphoton microscopy

NASA Astrophysics Data System (ADS)

Kazarine, Alexei; Bouhabel, Sarah; Douillette, Annie H.; Kost, Karen; Li-Jessen, Nicole Y. K.; Mongeau, Luc; Wiseman, Paul W.

2017-02-01

Vocal fold scarring as a result of injury or disease can lead to voice disorders which can significantly affect the quality of life. During the scarring process, the normally elastic tissue of the vocal fold lamina propria is replaced by a much stiffer collagen-based fibrotic tissue, which impacts the fold's ability to vibrate. Surgical removal of this tissue is often ineffective and can result in further scarring. Injectable biomaterials, a form of tissue engineering, have been proposed as a potential solution to reduce existing scars or prevent scarring altogether. In order to properly evaluate the effectiveness of these new materials, multiphoton microscopy emerges as an effective tool due to its intrinsic multiple label free contrast mechanisms that highlight extracellular matrix elements. In this study, we evaluate the spatial distribution of collagen and elastin fibers in a rabbit model using second harmonic generation (SHG), third harmonic generation (THG) and two photon autofluorescence (TPAF) applied to unlabeled tissue sections. In comparison to traditional methods that rely on histological staining or immunohistochemistry, SHG, THG and TPAF provide a more reliable detection of these native proteins. The evaluation of collagen levels allows us to follow the extent of scarring, while the presence of elastin fibers is thought to be indicative of the level of healing of the injured fold. Using these imaging modalities, we characterize the outcome of injectable biomaterial treatments in order to direct future treatments for tissue engineering.

Reduced Utilization of Selenium by Naked Mole Rats Due to a Specific Defect in GPx1 Expression*

PubMed Central

Kasaikina, Marina V.; Lobanov, Alexei V.; Malinouski, Mikalai Y.; Lee, Byung Cheon; Seravalli, Javier; Fomenko, Dmitri E.; Turanov, Anton A.; Finney, Lydia; Vogt, Stefan; Park, Thomas J.; Miller, Richard A.; Hatfield, Dolph L.; Gladyshev, Vadim N.

2011-01-01

Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase activities were similar in mice and MR. However, glutathione peroxidase activity was an order of magnitude lower in MR liver and kidney than in mouse tissues. In addition, metabolic labeling of MR cells with 75Se revealed a loss of the abundant glutathione peroxidase 1 (GPx1) band, whereas other selenoproteins were preserved. To characterize the MR selenoproteome, we sequenced its liver transcriptome. Gene reconstruction revealed standard selenoprotein sequences except for GPx1, which had an early stop codon, and SelP, which had low selenocysteine content. When expressed in HEK 293 cells, MR GPx1 was present in low levels, and its expression could be rescued neither by removing the early stop codon nor by replacing its SECIS element. In addition, GPx1 mRNA was present in lower levels in MR liver than in mouse liver. To determine if GPx1 deficiency could account for the reduced selenium content, we analyzed GPx1 knock-out mice and found reduced selenium levels in their livers and kidneys. Thus, MR is characterized by the reduced utilization of selenium due to a specific defect in GPx1 expression. PMID:21372135

The broccoli (Brassica oleracea) phloem tissue proteome.

PubMed

Anstead, James A; Hartson, Steven D; Thompson, Gary A

2013-11-07

The transport of sugars, hormones, amino acids, proteins, sugar alcohols, and other organic compounds from the sites of synthesis to the sites of use or storage occurs through the conducting cells of the phloem. To better understand these processes a comprehensive understanding of the proteins involved is required. While a considerable amount of data has been obtained from proteomic analyses of phloem sap, this has mainly served to identify the soluble proteins that are translocated through the phloem network. In order to obtain more comprehensive proteomic data from phloem tissue we developed a simple dissection procedure to isolate phloem tissue from Brassica oleracea. The presence of a high density of phloem sieve elements was confirmed using light microscopy and fluorescently labeled sieve element-specific antibodies. To increase the depth of the proteomic analysis for membrane bound and associated proteins, soluble proteins were extracted first and subsequent extractions were carried out using two different detergents (SDS and CHAPSO). Across all three extractions almost four hundred proteins were identified and each extraction method added to the analysis demonstrating the utility of an approach combining several extraction protocols. The phloem was found to be enriched in proteins associated with biotic and abiotic stress responses and structural proteins. Subsequent expression analysis identified a number of genes that appear to be expressed exclusively or at very high levels in phloem tissue, including genes that are known to express specifically in the phloem as well as novel phloem genes.

SMAD1 and SMAD5 Expression Is Coordinately Regulated by FLI1 and GATA2 during Endothelial Development.

PubMed

Marks-Bluth, Jonathon; Khanna, Anchit; Chandrakanthan, Vashe; Thoms, Julie; Bee, Thomas; Eich, Christina; Kang, Young Chan; Knezevic, Kathy; Qiao, Qiao; Fitch, Simon; Oxburgh, Leif; Ottersbach, Katrin; Dzierzak, Elaine; de Bruijn, Marella F T R; Pimanda, John E

2015-06-01

The bone morphogenetic protein (BMP)/SMAD signaling pathway is a critical regulator of angiogenic sprouting and is involved in vascular development in the embryo. SMAD1 and SMAD5, the core mediators of BMP signaling, are vital for this activity, yet little is known about their transcriptional regulation in endothelial cells. Here, we have integrated multispecies sequence conservation, tissue-specific chromatin, in vitro reporter assay, and in vivo transgenic data to identify and validate Smad1+63 and the Smad5 promoter as tissue-specific cis-regulatory elements that are active in the developing endothelium. The activity of these elements in the endothelium was dependent on highly conserved ETS, GATA, and E-box motifs, and chromatin immunoprecipitation showed high levels of enrichment of FLI1, GATA2, and SCL at these sites in endothelial cell lines and E11 dorsal aortas in vivo. Knockdown of FLI1 and GATA2 but not SCL reduced the expression of SMAD1 and SMAD5 in endothelial cells in vitro. In contrast, CD31(+) cKit(-) endothelial cells harvested from embryonic day 9 (E9) aorta-gonad-mesonephros (AGM) regions of GATA2 null embryos showed reduced Smad1 but not Smad5 transcript levels. This is suggestive of a degree of in vivo selection where, in the case of reduced SMAD1 levels, endothelial cells with more robust SMAD5 expression have a selective advantage. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Space Radiation Program Element Tissue Sharing Initiative

NASA Technical Reports Server (NTRS)

Wu, H.; Huff, J. L.; Simonsen, L. C.

2014-01-01

Over the years, a large number of animal experiments have been conducted at the NASA Space Radiation Laboratory and other facilities under the support of the NASA Space Radiation Program Element (SRPE). Studies using rodents and other animal species to address the space radiation risks will remain a significant portion of the research portfolio of the Element. In order to maximize scientific return of the animal studies, SRPE is taking the initiative to promote tissue sharing among the scientists in the space radiation research community. This initiative is enthusiastically supported by the community members as voiced in the responses to a recent survey. For retrospective tissue samples, an online platform will be established for the PIs to post a list of the available samples, and to exchange information with the potential recipients. For future animal experiments, a tissue sharing policy is being developed by SRPE.

Evaluation of the use of Leptodactylus ocellatus (Anura: Leptodactylidae) frog tissues as bioindicator of metal contamination in Contas River, Northeastern Brazil.

PubMed

Correia, Lívia O; Siqueira Júnior, Sérgio; Carneiro, Paulo L S; Bezerra, Marcos A

2014-12-01

This paper presents a study on the viability of the use of tissues of the Leptodactylus ocellatus species (Anura Leptodactylidae) as a bioindicator of metal pollution. The study is based on the determination and correlation of the concentrations of manganese, chromium, zinc, nickel, copper and iron in sediments and tissues (skin, muscles and viscera) of the frog Leptodactylus ocellatus collected in the middle region of the Contas River in Bahia, Brazil. The highest levels of the metals studied were found in the viscera of this animal. In this tissue, a higher correlation of the concentration of these metals with those found in sediments was also observed. The concentrations of elements found in the skin and muscles of these amphibians have revealed no correlation with the sediment where they were collected. According to the results obtained, the viscera of the L. ocellatus species presents itself as a good bioindicator of contamination by the metals studied.

Evaluation of the use of Leptodactylus ocellatus (Anura: Leptodactylidae) frog tissues as bioindicator of metal contamination in Contas River, Northeastern Brazil.

PubMed

Correia, Lívia O; Siqueira Júnior, Sérgio; Carneiro, Paulo L S; Bezerra, Marcos A

2014-10-24

This paper presents a study on the viability of the use of tissues of the Leptodactylus ocellatus species (Anura Leptodactylidae) as a bioindicator of metal pollution. The study is based on the determination and correlation of the concentrations of manganese, chromium, zinc, nickel, copper and iron in sediments and tissues (skin, muscles and viscera) of the frog Leptodactylus ocellatus collected in the middle region of the Contas River in Bahia, Brazil. The highest levels of the metals studied were found in the viscera of this animal. In this tissue, a higher correlation of the concentration of these metals with those found in sediments was also observed. The concentrations of elements found in the skin and muscles of these amphibians have revealed no correlation with the sediment where they were collected. According to the results obtained, the viscera of the L. ocellatus species presents itself as a good bioindicator of contamination by the metals studied.

HIF isoforms in the skin differentially regulate systemic arterial pressure

PubMed Central

Cowburn, Andrew S.; Takeda, Norihiko; Boutin, Adam T.; Kim, Jung-Whan; Sterling, Jane C.; Nakasaki, Manando; Southwood, Mark; Goldrath, Ananda W.; Jamora, Colin; Nizet, Victor; Chilvers, Edwin R.; Johnson, Randall S.

2013-01-01

Vascular flow through tissues is regulated via a number of homeostatic mechanisms. Localized control of tissue blood flow, or autoregulation, is a key factor in regulating tissue perfusion and oxygenation. We show here that the net balance between two hypoxia-inducible factor (HIF) transcription factor isoforms, HIF-1α and HIF-2α, is an essential mechanism regulating both local and systemic blood flow in the skin of mice. We also show that balance of HIF isoforms in keratinocyte-specific mutant mice affects thermal adaptation, exercise capacity, and systemic arterial pressure. The two primary HIF isoforms achieve these effects in opposing ways that are associated with HIF isoform regulation of nitric oxide production. We also show that a correlation exists between altered levels of HIF isoforms in the skin and the degree of idiopathic hypertension in human subjects. Thus, the balance between HIF-1α and HIF-2α expression in keratinocytes is a control element of both tissue perfusion and systemic arterial pressure, with potential implications in human hypertension. PMID:24101470

Early demethylation of non-CpG, CpC-rich, elements in the myogenin 5′-flanking region

PubMed Central

Fuso, Andrea; Ferraguti, Giampiero; Grandoni, Francesco; Ruggeri, Raffaella; Scarpa, Sigfrido; Strom, Roberto

2010-01-01

The dynamic changes and structural patterns of DNA methylation of genes without CpG islands are poorly characterized. The relevance of CpG to the non-CpG methylation equilibrium in transcriptional repression is unknown. In this work, we analyzed the DNA methylation pattern of the 5′-flanking of the myogenin gene, a positive regulator of muscle differentiation with no CpG island and low CpG density, in both C2C12 muscle satellite cells and embryonic muscle. Embryonic brain was studied as a non-expressing tissue. High levels of both CpG and non-CpG methylation were observed in non-expressing experimental conditions. Both CpG and non-CpG methylation rapidly dropped during muscle differentiation and myogenin transcriptional activation with active demethylation dynamics. Non-CpG demethylation occurred more rapidly than CpG demethylation. Demethylation spread from initially highly methylated short CpC-rich elements to a virtually unmethylated status. These short elements have a high CpC content and density, share some motifs and largely coincide with putative recognition sequences of some differentiation-related transcription factors. Our findings point to a dynamically controlled equilibrium between CpG and non-CpG active demethylation in the transcriptional control of tissue-specific genes. The short CpC-rich elements are new structural features of the methylation machinery, whose functions may include priming the complete demethylation of a transcriptionally crucial DNA region. PMID:20935518

Modeling and Characterization of Capacitive Elements With Tissue as Dielectric Material for Wireless Powering of Neural Implants.

PubMed

Erfani, Reza; Marefat, Fatemeh; Sodagar, Amir M; Mohseni, Pedram

2018-05-01

This paper reports on the modeling and characterization of capacitive elements with tissue as the dielectric material, representing the core building block of a capacitive link for wireless power transfer to neural implants. Each capacitive element consists of two parallel plates that are aligned around the tissue layer and incorporate a grounded, guarded, capacitive pad to mitigate the adverse effect of stray capacitances and shield the plates from external interfering electric fields. The plates are also coated with a biocompatible, insulating, coating layer on the inner side of each plate in contact with the tissue. A comprehensive circuit model is presented that accounts for the effect of the coating layers and is validated by measurements of the equivalent capacitance as well as impedance magnitude/phase of the parallel plates over a wide frequency range of 1 kHz-10 MHz. Using insulating coating layers of Parylene-C at a thickness of and Parylene-N at a thickness of deposited on two sets of parallel plates with different sizes and shapes of the guarded pad, our modeling and characterization results accurately capture the effect of the thickness and electrical properties of the coating layers on the behavior of the capacitive elements over frequency and with different tissues.

Tissue culture-induced transpositional activity of mPing is correlated with cytosine methylation in rice

PubMed Central

Ngezahayo, Frédéric; Xu, Chunming; Wang, Hongyan; Jiang, Lily; Pang, Jinsong; Liu, Bao

2009-01-01

Background mPing is an endogenous MITE in the rice genome, which is quiescent under normal conditions but can be induced towards mobilization under various stresses. The cellular mechanism responsible for modulating the activity of mPing remains unknown. Cytosine methylation is a major epigenetic modification in most eukaryotes, and the primary function of which is to serve as a genome defense system including taming activity of transposable elements (TEs). Given that tissue-culture is capable of inducing both methylation alteration and mPing transposition in certain rice genotypes, it provides a tractable system to investigate the possible relationship between the two phenomena. Results mPing transposition and cytosine methylation alteration were measured in callus and regenerated plants in three rice (ssp. indica) genotypes, V14, V27 and R09. All three genotypes showed transposition of mPing, though at various frequencies. Cytosine methylation alteration occurred both at the mPing-flanks and at random loci sampled globally in callus and regenerated plants of all three genotypes. However, a sharp difference in the changing patterns was noted between the mPing-flanks and random genomic loci, with a particular type of methylation modification, i.e., CNG hypermethylation, occurred predominantly at the mPing-flanks. Pearson's test on pairwise correlations indicated that mPing activity is positively correlated with specific patterns of methylation alteration at random genomic loci, while the element's immobility is positively correlated with methylation levels of the mPing's 5'-flanks. Bisulfite sequencing of two mPing-containing loci showed that whereas for the immobile locus loss of CG methylation in the 5'-flank was accompanied by an increase in CHG methylation, together with an overall increase in methylation of all three types (CG, CHG and CHH) in the mPing-body region, for the active locus erasure of CG methylation in the 5'-flank was not followed by such a change. Conclusion Our results documented that tissue culture-induced mPing activity in rice ssp. indica is correlated with alteration in cytosine methylation patterns at both random genomic loci and the elements' flanks, while the stability of mPing positively correlates with enhanced methylation levels of both the flanks and probably the elements per se. Thus, our results implicate a possible role of cytosine methylation in maintaining mPing stability under normal conditions, and in releasing the element's activity as a consequence of epigenetic perturbation in a locus-specific manner under certain stress conditions. PMID:19604382

Distribution of trace elements in the aquatic ecosystem of the Thigithe river and the fish Labeo victorianus in Tanzania and possible risks for human consumption.

PubMed

Mataba, Gordian Rocky; Verhaert, Vera; Blust, Ronny; Bervoets, Lieven

2016-03-15

The aim of the present study was to assess the distribution of trace elements in the aquatic ecosystem of the Thigithe river. Samples of surface water, sediment and fish were collected up- and downstream of the North Mara Gold Mine (Tanzania) and following trace elements were analysed: As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Trace element concentrations in surface water were below or near the detection limit. Regarding the sediments, relative high concentrations of arsenic at all sites and high levels of mercury at a site downstream of the mine where artisanal mining is performed were observed. Trace element concentrations in Ningu fish tissues (Labeo victorianus) were comparable to slightly higher than levels in fishes from unpolluted environments. For none of the measured human health risk by consumption of fish from the Thigithe river is expected when the Tanzanian average amount of 17 g/day is consumed. However, for Hg and As the advised maximum daily consumption of Ningu fish was lower than 100g. As a result fishermen and people living along the shores of the river consuming more fish than the average Tanzanian fish consumption set by the FAO (2005) are possibly at risk. Copyright © 2015 Elsevier B.V. All rights reserved.

Two novel elements (CFG1 and PYG1) of Mag lineage of Ty3/Gypsy retrotransposons from Zhikong scallop (Chlamys farreri) and Japanese scallop (Patinopecten yessoensis).

PubMed

Wang, Shi; Bao, Zhenmin; Hu, Xiaoli; Shao, Mingyu; Zhang, Lingling; Hu, Jingjie

2008-05-01

Two novel elements (CFG1 and PYG1) of Mag lineage of Ty3/Gypsy retrotransposons were cloned from Zhikong scallop (Chlamys farreri) and Japanese scallop (Patinopecten yessoensis). The total length of the CFG1 element is 4826 bp, including 5'-LTR (192 bp), the entire ORF (4047 bp) and 3'-LTR (189 bp). The entire ORFs of both CFG1 and PYG1 elements are composed of 1348 aa and do not have any frameshifts. Their closest relative is Jule element from the poeciliid fish (Xiphophorus maculatus). On average, the diploid genome of C. farreri contains approximately 84 copies of CFG1 elements. We summarize the major features of CFG1, PYG1 and other elements of Mag lineage of the Ty3/Gypsy group. mRNA expression of CFG1 element in larvae increases gradually before the gastrulae stage and decreases gradually afterward, whereas in adductor such expression in adductor muscle and digestive gland are lower than those in other tissues. Overall, mRNA expression of CFG1 element in the early larvae is significantly higher than that in adult tissues. In muscle tissue, while the promoter and partial GAG domain of CFG1 element are unmethylated, the partial RT domain is highly methylated. These results suggest that CFG1 expression may be controlled by a post-transcriptional gene silencing mechanism that is associated with coding-region (RT domain) methylation.

Assessment of oxidative stress markers and concentrations of selected elements in the leaves of Cassia occidentalis growing wild on a coal fly ash basin.

PubMed

Love, Amit; Banerjee, B D; Babu, C R

2013-08-01

Assessment of oxidative stress levels and tissue concentrations of elements in plants growing wild on fly ash basins is critical for realistic hazard identification of fly ash disposal areas. Hitherto, levels of oxidative stress markers in plants growing wild on fly ash basins have not been adequately investigated. We report here concentrations of selected metal and metalloid elements and levels of oxidative stress markers in leaves of Cassia occidentalis growing wild on a fly ash basin (Badarpur Thermal Power Station site) and a reference site (Garhi Mandu Van site). Plants growing on the fly ash basin had significantly high foliar concentration of As, Ni, Pb and Se and low foliar concentration of Mn and Fe compared to the plants growing on the reference site. The plants inhabiting the fly ash basin showed signs of oxidative stress and had elevated levels of lipid peroxidation, electrolyte leakage from cells and low levels of chlorophyll a and total carotenoids compared to plants growing at the reference site. The levels of both protein thiols and nonprotein thiols were elevated in plants growing on the fly ash basin compared to plants growing on the reference site. However, no differences were observed in the levels of cysteine, reduced glutathione and oxidized glutathione in plants growing at both the sites. Our study suggests that: (1) fly ash triggers oxidative stress responses in plants growing wild on fly ash basin, and (2) elevated levels of protein thiols and nonprotein thiols may have a role in protecting the plants from environmental stress.

Determination of element levels in human serum: Total reflection X-ray fluorescence applications

NASA Astrophysics Data System (ADS)

Majewska, U.; Łyżwa, P.; Łyżwa, K.; Banaś, D.; Kubala-Kukuś, A.; Wudarczyk-Moćko, J.; Stabrawa, I.; Braziewicz, J.; Pajek, M.; Antczak, G.; Borkowska, B.; Góźdź, S.

2016-08-01

Deficiency or excess of elements could disrupt proper functioning of the human body and could lead to several disorders. Determination of their concentrations in different biological human fluids and tissues should become a routine practice in medical treatment. Therefore the knowledge about appropriate element concentrations in human organism is required. The purpose of this study was to determine the concentration of several elements (P, S, Cl, K, Ca, Cr, Fe, Cu, Zn, Se, Br, Rb, Pb) in human serum and to define the reference values of element concentration. Samples of serum were obtained from 105 normal presumably healthy volunteers (66 women aged between 15 and 78 years old; 39 men aged between 15 and 77 years old). Analysis has been done for the whole studied population and for subgroups by sex and age. It is probably first so a wide study of elemental composition of serum performed in the case of Świętokrzyskie region. Total reflection X-ray fluorescence (TXRF) method was used to perform the elemental analysis. Spectrometer S2 Picofox (Bruker AXS Microanalysis GmbH) was used to identify and measure elemental composition of serum samples. Finally, 1st and 3rd quartiles were accepted as minimum and maximum values of concentration reference range.

Qualitative tissue differentiation by analysing the intensity ratios of atomic emission lines using laser induced breakdown spectroscopy (LIBS): prospects for a feedback mechanism for surgical laser systems.

PubMed

Kanawade, Rajesh; Mahari, Fanuel; Klämpfl, Florian; Rohde, Maximilian; Knipfer, Christian; Tangermann-Gerk, Katja; Adler, Werner; Schmidt, Michael; Stelzle, Florian

2015-01-01

The research work presented in this paper focuses on qualitative tissue differentiation by monitoring the intensity ratios of atomic emissions using 'Laser Induced Breakdown Spectroscopy' (LIBS) on the plasma plume created during laser tissue ablation. The background of this study is to establish a real time feedback control mechanism for clinical laser surgery systems during the laser ablation process. Ex-vivo domestic pig tissue samples (muscle, fat, nerve and skin) were used in this experiment. Atomic emission intensity ratios were analyzed to find a characteristic spectral line for each tissue. The results showed characteristic elemental emission intensity ratios for the respective tissues. The spectral lines and intensity ratios of these specific elements varied among the different tissue types. The main goal of this study is to qualitatively and precisely identify different tissue types for tissue specific laser surgery. © 2015 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag.

A tissue dose-based comparative exposure assessment of manganese using physiologically based pharmacokinetic modeling—The importance of homeostatic control for an essential metal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gentry, P. Robinan, E-mail: rgentry@ramboll.com

A physiologically-based pharmacokinetic (PBPK) model (Schroeter et al., 2011) was applied to simulate target tissue manganese (Mn) concentrations following occupational and environmental exposures. These estimates of target tissue Mn concentrations were compared to determine margins of safety (MOS) and to evaluate the biological relevance of applying safety factors to derive acceptable Mn air concentrations. Mn blood concentrations measured in occupational studies permitted verification of the human PBPK models, increasing confidence in the resulting estimates. Mn exposure was determined based on measured ambient air Mn concentrations and dietary data in Canada and the United States (US). Incorporating dietary and inhalation exposuresmore » into the models indicated that increases in target tissue concentrations above endogenous levels only begin to occur when humans are exposed to levels of Mn in ambient air (i.e. > 10 μg/m{sup 3}) that are far higher than those currently measured in Canada or the US. A MOS greater than three orders of magnitude was observed, indicating that current Mn air concentrations are far below concentrations that would be required to produce the target tissue Mn concentrations associated with subclinical neurological effects. This application of PBPK modeling for an essential element clearly demonstrates that the conventional application of default factors to “convert” an occupational exposure to an equivalent continuous environmental exposure, followed by the application of safety factors, is not appropriate in the case of Mn. PBPK modeling demonstrates that the relationship between ambient Mn exposures and dose-to-target tissue is not linear due to normal tissue background levels and homeostatic controls. - Highlights: • Manganese is an essential nutrient, adding complexity to its risk assessment. • Nonlinearities in biological processes are important for manganese risk assessment. • A PBPK model was used to estimate target tissue concentrations of manganese. • An MOS approach also considered target tissue concentrations for ambient exposures. • Relationships between ambient Mn exposures and dose-to-target tissue are not linear.« less

Meta-analysis of selenium accumulation and expression of antioxidant enzymes in chicken tissues.

PubMed

Zoidis, E; Demiris, N; Kominakis, A; Pappas, A C

2014-04-01

A meta-analysis integrating results of 40 selenium (Se) supplementation experiments that originated from 35 different controlled randomized trials was carried out in an attempt to identify significant factors that affect tissue Se accumulation in chicken. Examined factors included: Se source (12 different sources examined), type of chicken (laying hens or broilers), age of birds at the beginning of supplementation, duration of supplementation, year during which the study was conducted, sex of birds, number of chickens per treatment, method of analysis, tissue type, concentration of Se determined and Se added to feed. A correlation analysis was also carried out between tissue Se concentration and glutathione peroxidase activity. Data analysis showed that the factors significantly affecting tissue Se concentration include type of chicken (P=0.006), type of tissue (P<0.001) and the analytical method used (P=0.014). Although Se source was not found to affect tissue Se concentration (overall P>0.05), certain inorganic (sodium selenite), calcium selenite, sodium selenate and organic sources (B-Traxim Se), Se-yeast, Se-malt, Se-enriched cabbage and Se-enriched garlic as well as background Se level from feed ingredients were found to significantly affect tissue Se concentration. The Se accumulation rate (estimated as linear regression coefficient of Se concentrations to Se added to feed) discriminated between the various tissues with highest values estimated in the leg muscle and lowest in blood plasma. Correlation analysis has also shown that tissue Se concentration (pooled data) was correlated to Se added to feed (r=0.529, P<0.01, log values) and to glutathione peroxidase activity (r=0.332, P=0.0478), with the latter not being correlated with Se added to feed. Although significant factors affecting Se concentration were reported in the present study, they do not necessarily indicate the in vivo function of the antioxidant system or the level of accumulated Se as other factors, not examined in the present study, may interact at the level of trace element absorption, distribution and retention.

Assessing behind armor blunt trauma (BABT) under NIJ standard-0101.04 conditions using human torso models.

PubMed

Merkle, Andrew C; Ward, Emily E; O'Connor, James V; Roberts, Jack C

2008-06-01

Although soft armor vests serve to prevent penetrating wounds and dissipate impact energy, the potential of nonpenetrating injury to the thorax, termed behind armor blunt trauma, does exist. Currently, the ballistic resistance of personal body armor is determined by impacting a soft armor vest over a clay backing and measuring the resulting clay deformation as specified in National Institute of Justice (NIJ) Standard-0101.04. This research effort evaluated the efficacy of a physical Human Surrogate Torso Model (HSTM) as a device for determining thoracic response when exposed to impact conditions specified in the NIJ Standard. The HSTM was subjected to a series of ballistic impacts over the sternum and stomach. The pressure waves propagating through the torso were measured with sensors installed in the organs. A previously developed Human Torso Finite Element Model (HTFEM) was used to analyze the amount of tissue displacement during impact and compared with the amount of clay deformation predicted by a validated finite element model. All experiments and simulations were conducted at NIJ Standard test conditions. When normalized by the response at the lowest threat level (Level I), the clay deformations for the higher levels are relatively constant and range from 2.3 to 2.7 times that of the base threat level. However, the pressures in the HSTM increase with each test level and range from three to seven times greater than Level I depending on the organ. The results demonstrate the abilities of the HSTM to discriminate between threat levels, impact conditions, and impact locations. The HTFEM and HSTM are capable of realizing pressure and displacement differences because of the level of protection, surrounding tissue, and proximity to the impact point. The results of this research provide insight into the transfer of energy and pressure wave propagation during ballistic impacts using a physical surrogate and computational model of the human torso.

The effect of dietary carbohydrate on genes for fatty acid synthase and inflammatory cytokines in adipose tissues from lean and obese subjects.

PubMed

Hudgins, Lisa C; Baday, Aline; Hellerstein, Marc K; Parker, Thomas S; Levine, Daniel M; Seidman, Cynthia E; Neese, Richard A; Tremaroli, Jolanta D; Hirsch, Jules

2008-04-01

Hepatic de novo lipogenesis (DNL) is markedly stimulated in humans by low-fat diets enriched in simple sugars. However, the dietary responsiveness of the key enzyme controlling DNL in human adipose tissue, fatty acid synthase (FAS), is uncertain. Adipose tissue mRNA for FAS is increased in lean and obese subjects when hepatic DNL is elevated by a eucaloric, low-fat, high-sugar diet. Twelve lean and seven obese volunteers were given two eucaloric diets (10% vs. 30% fat; 75% vs. 55% carbohydrate; sugar/starch 60/40) each for 2 weeks by a random-order cross-over design. FAS mRNA in abdominal and gluteal adipose tissues was compared to hepatic DNL measured in serum by isotopic and nonisotopic methods. Adipose tissue mRNA for tumor necrosis factor-alpha and IL-6, which are inflammatory cytokines that modulate DNL, was also assayed. The low-fat high-sugar diet induced a 4-fold increase in maximum hepatic DNL (P<.001) but only a 1.3-fold increase in adipose tissue FAS mRNA (P=.029) and no change in cytokine mRNA. There was a borderline significant positive correlation between changes in FAS mRNA and hepatic DNL (P=.039). Compared to lean subjects, obese subjects had lower levels of FAS mRNA and higher levels of cytokine mRNA (P<.001). The results suggest that key elements of human adipose tissue DNL are less responsive to dietary carbohydrate than is hepatic DNL and may be regulated by diet-independent factors. Irrespective of diet, there is reduced expression of the FAS gene and increased expression of cytokine genes in adipose tissues of obese subjects.

Evaluation of tissue interactions with mechanical elements of a transscleral drug delivery device.

PubMed

Cohen, Sarah J; Chan, Robison V Paul; Keegan, Mark; Andreoli, Christopher M; Borenstein, Jeffrey T; Miller, Joan W; Gragoudas, Evangelos S

2012-03-12

The goal of this work was to evaluate tissue-device interactions due to implantation of a mechanically operated drug delivery system onto the posterior sclera. Two test devices were designed and fabricated to model elements of the drug delivery device-one containing a free-spinning ball bearing and the other encasing two articulating gears. Openings in the base of test devices modeled ports for drug passage from device to sclera. Porous poly(tetrafluoroethylene) (PTFE) membranes were attached to half of the gear devices to minimize tissue ingrowth through these ports. Test devices were sutured onto rabbit eyes for 10 weeks. Tissue-device interactions were evaluated histologically and mechanically after removal to determine effects on device function and changes in surrounding tissue. Test devices were generally well-tolerated during residence in the animal. All devices encouraged fibrous tissue formation between the sclera and the device, fibrous tissue encapsulation and invasion around the device, and inflammation of the conjunctiva. Gear devices encouraged significantly greater inflammation in all cases and a larger rate of tissue ingrowth. PTFE membranes prevented tissue invasion through the covered drug ports, though tissue migrated in through other smaller openings. The torque required to turn the mechanical elements increased over 1000 times for gear devices, but only on the order of 100 times for membrane-covered gear devices and less than 100 times for ball bearing devices. Maintaining a lower device profile, minimizing microscale motion on the eye surface and covering drug ports with a porous membrane may minimize inflammation, decreasing the risk of damage to surrounding tissues and minimizing disruption of device operation.

A Spectral Finite Element Approach to Modeling Soft Solids Excited with High-Frequency Harmonic Loads

PubMed Central

Brigham, John C.; Aquino, Wilkins; Aguilo, Miguel A.; Diamessis, Peter J.

2010-01-01

An approach for efficient and accurate finite element analysis of harmonically excited soft solids using high-order spectral finite elements is presented and evaluated. The Helmholtz-type equations used to model such systems suffer from additional numerical error known as pollution when excitation frequency becomes high relative to stiffness (i.e. high wave number), which is the case, for example, for soft tissues subject to ultrasound excitations. The use of high-order polynomial elements allows for a reduction in this pollution error, but requires additional consideration to counteract Runge's phenomenon and/or poor linear system conditioning, which has led to the use of spectral element approaches. This work examines in detail the computational benefits and practical applicability of high-order spectral elements for such problems. The spectral elements examined are tensor product elements (i.e. quad or brick elements) of high-order Lagrangian polynomials with non-uniformly distributed Gauss-Lobatto-Legendre nodal points. A shear plane wave example is presented to show the dependence of the accuracy and computational expense of high-order elements on wave number. Then, a convergence study for a viscoelastic acoustic-structure interaction finite element model of an actual ultrasound driven vibroacoustic experiment is shown. The number of degrees of freedom required for a given accuracy level was found to consistently decrease with increasing element order. However, the computationally optimal element order was found to strongly depend on the wave number. PMID:21461402

The association between content of the elements S, Cl, K, Fe, Cu, Zn and Br in normal and cirrhotic liver tissue from Danes and Greenlandic Inuit examined by dual hierarchical clustering analysis.

PubMed

Laursen, Jens; Milman, Nils; Pind, Niels; Pedersen, Henrik; Mulvad, Gert

2014-01-01

Meta-analysis of previous studies evaluating associations between content of elements sulphur (S), chlorine (Cl), potassium (K), iron (Fe), copper (Cu), zinc (Zn) and bromine (Br) in normal and cirrhotic autopsy liver tissue samples. Normal liver samples from 45 Greenlandic Inuit, median age 60 years and from 71 Danes, median age 61 years. Cirrhotic liver samples from 27 Danes, median age 71 years. Element content was measured using X-ray fluorescence spectrometry. Dual hierarchical clustering analysis, creating a dual dendrogram, one clustering element contents according to calculated similarities, one clustering elements according to correlation coefficients between the element contents, both using Euclidian distance and Ward Procedure. One dendrogram separated subjects in 7 clusters showing no differences in ethnicity, gender or age. The analysis discriminated between elements in normal and cirrhotic livers. The other dendrogram clustered elements in four clusters: sulphur and chlorine; copper and bromine; potassium and zinc; iron. There were significant correlations between the elements in normal liver samples: S was associated with Cl, K, Br and Zn; Cl with S and Br; K with S, Br and Zn; Cu with Br. Zn with S and K. Br with S, Cl, K and Cu. Fe did not show significant associations with any other element. In contrast to simple statistical methods, which analyses content of elements separately one by one, dual hierarchical clustering analysis incorporates all elements at the same time and can be used to examine the linkage and interplay between multiple elements in tissue samples. Copyright © 2013 Elsevier GmbH. All rights reserved.

Multiscale strain analysis of tissue equivalents using a custom-designed biaxial testing device.

PubMed

Bell, B J; Nauman, E; Voytik-Harbin, S L

2012-03-21

Mechanical signals transferred between a cell and its extracellular matrix play an important role in regulating fundamental cell behavior. To further define the complex mechanical interactions between cells and matrix from a multiscale perspective, a biaxial testing device was designed and built. Finite element analysis was used to optimize the cruciform specimen geometry so that stresses within the central region were concentrated and homogenous while minimizing shear and grip effects. This system was used to apply an equibiaxial loading and unloading regimen to fibroblast-seeded tissue equivalents. Digital image correlation and spot tracking were used to calculate three-dimensional strains and associated strain transfer ratios at macro (construct), meso, matrix (collagen fibril), cell (mitochondria), and nuclear levels. At meso and matrix levels, strains in the 1- and 2-direction were statistically similar throughout the loading-unloading cycle. Interestingly, a significant amplification of cellular and nuclear strains was observed in the direction perpendicular to the cell axis. Findings indicate that strain transfer is dependent upon local anisotropies generated by the cell-matrix force balance. Such multiscale approaches to tissue mechanics will assist in advancement of modern biomechanical theories as well as development and optimization of preconditioning regimens for functional engineered tissue constructs. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Updated Lagrangian finite element formulations of various biological soft tissue non-linear material models: a comprehensive procedure and review.

PubMed

Townsend, Molly T; Sarigul-Klijn, Nesrin

2016-01-01

Simplified material models are commonly used in computational simulation of biological soft tissue as an approximation of the complicated material response and to minimize computational resources. However, the simulation of complex loadings, such as long-duration tissue swelling, necessitates complex models that are not easy to formulate. This paper strives to offer the updated Lagrangian formulation comprehensive procedure of various non-linear material models for the application of finite element analysis of biological soft tissues including a definition of the Cauchy stress and the spatial tangential stiffness. The relationships between water content, osmotic pressure, ionic concentration and the pore pressure stress of the tissue are discussed with the merits of these models and their applications.

Evaluating optimal superficial limb perfusion at different angles using non-invasive micro-lightguide spectrophotometry.

PubMed

Darmanin, Geraldine; Jaggard, Matthew; Hettiaratchy, Shehan; Nanchahal, Jagdeep; Jain, Abhilash

2013-06-01

It is common practice to elevate the limbs postoperatively to reduce oedema and hence optimise perfusion and facilitate rehabilitation. However, elevation may be counterproductive as it reduces the mean perfusion pressure. There are no clear data on the optimal position of the limbs even in normal subjects. The optimal position of limbs was investigated in 25 healthy subjects using a non-invasive micro-lightguide spectrophotometry system "O2C", which indirectly measures skin and superficial tissue perfusion through blood flow, oxygen saturation and relative haemoglobin concentration. We found a reduction in skin and superficial tissue blood flow of 17% (p=0.0001) on arm elevation (180° shoulder flexion) as compared to heart level and an increase in skin and superficial tissue blood flow of 25% (p=0.02) on forearm elevation of 45°. Lower limb skin and superficial tissue blood flow decreased by 15% (p=0.004) on elevation to 47 cm and by 70% on dependency (p=0.0001) compared to heart level. However, on elevation of the lower limb there was also a 28% reduction in superficial venous pooling (p=0.0001) compared to heart level. In the normal limb, the position for optimal superficial perfusion of the upper limb is with the arm placed at heart level and forearm at 45°. In the lower limb the optimal position for superficial perfusion would be at heart level. However, some degree of elevation may be useful if there is an element of venous congestion. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Ion Imbalance Is Involved in the Mechanisms of Liver Oxidative Damage in Rats Exposed to Glyphosate

PubMed Central

Tang, Juan; Hu, Ping; Li, Yansen; Win-Shwe, Tin-Tin; Li, Chunmei

2017-01-01

Glyphosate (N-phosphonomethyl-glycine, GLP) is the most popular herbicide used worldwide. This study aimed to investigate the effects of glyphosate on rats' liver function and induction of pathological changes in ion levels and oxidative stress in hepatic tissue. Sprague-Dawley rats were treated orally with 0, 5, 50, and 500 mg/kg body weight of the GLP. After 5 weeks of treatment, blood and liver samples were analyzed for biochemical and histomorphological parameters. The various mineral elements content in the organs of the rats were also measured. Significant decreases were shown in the weights of body, liver, kidney and spleen between the control and treatment groups. Changes also happened in the histomorphology of the liver and kidney tissue of GLP-treated rats. The GLP resulted in an elevated level of glutamic-oxalacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and IL-1β in the serum. Besides, decreased total superoxide dismutase (T-SOD) activity and increased malondialdehyde (MDA) contents in the serum, liver, and kidney indicated the presence of oxidative stress. Moreover, increase of hydrogen peroxide (H2O2) level and catalase (CAT) activity in the serum and liver and decrease of glutathione (GSH) and lutathione peroxidase (GSH-Px) activity in the kidney tissue further confirmed the occurrence of oxidative stress. The results of RT-PCR showed that the mRNA expressions of IL-1α, IL-1β, IL-6, MAPK3, NF-κB, SIRT1, TNF-α, Keap1, GPX2, and Caspase-3 were significantly increased in the GLP-treated groups compared to the control group. Furthermore, PPARα, DGAT, SREBP1c, and SCD1 mRNA expressions were also remarkably increased in the GLP-treated groups compared to the control group. In addition, aluminum (Al), iron (Fe), copper (Cu), zinc (Zn), and magnesium (Mg) levels were showed a significant difference reduction or increase in rat liver, kidney, spleen, lung, heart, muscle, brain, and fat tissues. These results suggested that glyphosate caused obvious damage to rats' liver and caused various mineral elements content imbalances in various organs of rats. Ion imbalance could weaken antioxidant capacity and involve in the mechanism of liver oxidative damage caused by GLP. PMID:29311996

Biological variables and health status affecting inorganic element concentrations in harbour porpoises (Phocoena phocoena) from Portugal (western Iberian Peninsula).

PubMed

Ferreira, Marisa; Monteiro, Silvia S; Torres, Jordi; Oliveira, Isabel; Sequeira, Marina; López, Alfredo; Vingada, José; Eira, Catarina

2016-03-01

The coastal preferences of harbour porpoise (Phocoena phocoena) intensify their exposure to human activities. The harbour porpoise Iberian population is presently very small and information about the threats it endures is vital for the conservation efforts that are being implemented to avoid local extinction. The present study explored the possible relation between the accumulation of trace elements by porpoises and their sex, body length, nutritional state, presence of parasites and gross pathologies. The concentrations of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn) and selenium (Se) were evaluated in 42 porpoises stranded in Portugal between 2005 and 2013. Considering European waters, porpoises stranded in Portugal present the highest Hg concentrations and the lowest Cd concentrations, which may reflect dietary preferences and the geographic availability of these pollutants. While no effect of sex on trace element concentrations was detected, there was a positive relationship between porpoise body length and the concentration of Cd, Hg and Pb. Animals in worse nutritional condition showed higher levels of Zn. Harbour porpoises with high parasite burdens showed lower levels of Zn and As in all analysed tissues and also lower levels of renal Ni, while those showing gross pathologies presented higher Zn and Hg levels. This is the first data on the relationship between trace elements and health-related variables in porpoises from southern European Atlantic waters, providing valuable baseline information about the contamination status of this vulnerable population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organochlorine compounds and trace elements in fish tissue and ancillary data for the Connecticut, Housatonic, and Thames river basins study unit, 1992-94

USGS Publications Warehouse

Coles, J.F.

1996-01-01

Concentrations of organochlorine compounds and trace elements were assayed in fish tissue collected from the Connecticut, Housatonic, and Thames River Basins Study Unit, 1992-94. These data were collected to determine the occurrence and distribution of organochlorine compounds and trace elements in the study unit. Ancillary data included are land-use categories by percentage of the sampling-site basins and the size, gender, and age of the individual fish collected for this study. Concentrations of 28 organochlorine compounds in composited whole fish samples were measured at 32 sites, and concentrations of 22 trace elements in composited fish liver samples were measured at 14 of the 32 sites. Most frequently detected organochlorines were DDT related compounds at 31 sites, total PCBs at 28 sites, and chlordane related compounds at 25 sites. Concentrations of total PCBs in fish tissue were generally higher at the large river sites than at the smaller tributary sites. Concentrations of chlordane-related compounds in fish tissue were higher at sites from more urbanized basins than at sites from predominately agriculture and forested basins. Concentrations of the DDT related compounds were undifferentiated among sites comprising different land uses. Trace elements detected at all 14 sites included boron, copper, iron, manganese, molybdenum, selenium, and zinc. Trace elements detected at 10 or more sites included arsenic, mercury, silver, strontium, and vanadium. Antimony, beryllium, and uranium were not detected at any site.

Dynamic changes in cortical tensions in multiple cell types during germband retraction

NASA Astrophysics Data System (ADS)

Hutson, M. Shane; Lacy, Monica E.; McCleery, W. Tyler

The process of germband retraction in Drosophila embryogenesis involves the coordinated mechanics of both germband and amnioserosa cells. These two tissues simultaneously and coordinately uncurl from their interlocking U-like shapes. As tissue-level retraction proceeds, individual cells change shape in stereotypical ways. Using time-lapse confocal images, analysis of dynamic cellular triple-junction angles, and whole-embryo finite-element models, we have quantified dynamic changes in cortical tensions - including their anisotropy - in both germband and amnioserosa cells. We find a strong transition midway through the two-hour course of retraction at which point tensions and anisotropies undergo a near step change. These changes take place among amnioserosa cells, in multiple segments of the germband, and at the interface between these two tissues. Research was supported by NIH Grant Numbers 1R01GM099107 and 1R21AR068933.

Endoscopic Full-Field Swept-Source Optical Coherence Tomography Neuroimaging System

NASA Astrophysics Data System (ADS)

Felts Almog, Ilan

Optical Coherence Tomography (OCT) has the capability to differentiate brain elements with intrinsic contrast and at a resolution an order-of-magnitude higher than other imaging modalities. This thesis investigates the feasibility of OCT for neuroimaging applied to neurosurgical guidance. We present, to our knowledge, the first Full-Field Swept-Source OCT system operating near a wavelength of 1310 nm, achieving a transverse imaging resolution of 6.5 mum, an axial resolution of 14 mum in tissue and a field of view of 270 mum x 180 mum x 400 mum. Imaging experiments were performed on rat brain tissues ex vivo, human cortical tissue ex vivo, and rats in vivo. A multi-level threshold metric applied on the intensity of the images led to a plausible correlation between the observed density and location in the brain. The proof-of-concept OCT system can be improved and miniaturized for clinical use.

Accumulation of polonium 210Po in tissues and organs of deer carvidae from Northern Poland.

PubMed

Skwarzec, Bogdan; Prucnal, Malgorzata

2007-01-01

This study was undertaken to provide information on accumulation of polonium in tissues and organs of deer carvidae in order to assess the potential transport of this element via food-chain to game meat consumers. Livers, kidneys and muscles of large herbivorous animals belonging to three species: roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama), collected in Northern Poland, were the subject of the present investigation. Activities of (210)Po were determined by means of alpha spectrometry along with relevant radiochemical procedures. The concentration of (210)Po in analyzed animals decreased in the order kidney > liver > muscle tissue. The average activity concentrations of (210)Po ranged between 0.02 +/- 0.01 Bq. kg(- 1) w.w. in muscles and 7.15 +/- 0.12 Bq. kg(- 1) w.w. in kidneys. Levels of polonium were not influenced by sampling location, sex, age and species of animals.

Applications of XRF, NAA and low-kV radiographic techniques in the study of body composition and diseased tissue

NASA Astrophysics Data System (ADS)

Bradley, D. A.; Ng, K. H.; Green, S.; Mountford, P. J.; Shukri, A.; Evans, J.

1996-05-01

Members of this group have responded to a number of challenging health issues by attempting to devise sensitive XRF, NAA and low-kV radiographic measurement systems foboth in vivo and in vitro applications. These studies are generally either of toxicological importance, examine potential for diagnosing the presence of disease, or offer effective means for monitoring potentially harmful side-effects of therapy. Particular examples include the in vivo XRF investigation of human skeletal uptake of Pb in working and living environments, in vivo XRF monitoring of elevated levels of Fe in skin (indicating the presence of an undesirable side-effect of the treatment of thalassaemia), in vivo NAA monitoring of elevated levels of Al in bone (indicating an undesirable side-effect of the treatment of chronic renal failure) and in vitro characterization, by means of low-kV imaging, of a range of calcification parameters in healthy and diseased breast tissue. The latter investigation has been conducted in association with an in vitro NAA study of concentrations of trace elements in the same types of tissue. Figures of merit for the various measurement systems have been obtained in terms of minimum detectable levels and concentrations (MDL's and MDC's) and where applicable, image related parameters.

From single fiber to macro-level mechanics: A structural finite-element model for elastomeric fibrous biomaterials

PubMed Central

D'Amore, Antonio; Amoroso, Nicholas; Gottardi, Riccardo; Hobson, Christopher; Carruthers, Christopher; Watkins, Simon; Wagner, William R.; Sacks, Michael S.

2014-01-01

In the present work, we demonstrate that the mesoscopic in-plane mechanical behavior of membrane elastomeric scaffolds can be simulated by replication of actual quantified fibrous geometries. Elastomeric electrospun polyurethane (ES-PEUU) scaffolds, with and without particulate inclusions, were utilized. Simulations were developed from experimentally-derived fiber network geometries, based on a range of scaffold isotropic and anisotropic behaviors. These were chosen to evaluate the effects on macro-mechanics based on measurable geometric parameters such as fiber intersections, connectivity, orientation, and diameter. Simulations were conducted with only the fiber material model parameters adjusted to match the macro-level mechanical test data. Fiber model validation was performed at the microscopic level by individual fiber mechanical tests using AFM. Results demonstrated very good agreement to the experimental data, and revealed the formation of extended preferential fiber orientations spanning the entire model space. We speculate that these emergent structures may be responsible for the tissue-like macroscale behaviors observed in electrospun scaffolds. To conclude, the modeling approach has implications for (1) gaining insight on the intricate relationship between fabrication variables, structure, and mechanics to manufacture more functional devices/materials, (2) elucidating the effects of cell or particulate inclusions on global construct mechanics, and (3) fabricating better performing tissue surrogates that could recapitulate native tissue mechanics. PMID:25128869

Impact of the Di(2-Ethylhexyl) Phthalate Administration on Trace Element and Mineral Levels in Relation of Kidney and Liver Damage in Rats.

PubMed

Aydemir, Duygu; Karabulut, Gözde; Şimşek, Gülsu; Gok, Muslum; Barlas, Nurhayat; Ulusu, Nuriye Nuray

2018-04-13

Di(2-ethylhexyl) phthalate (DEHP) is a widely used synthetic polymer in the industry. DEHP may induce reproductive and developmental toxicity, obesity, carcinogenesis and cause abnormal endocrine function in both human and wildlife. The aim of this study was to investigate trace element and mineral levels in relation of kidney and liver damage in DEHP-administered rats. Therefore, prepubertal male rats were dosed with 0, 100, 200, and 400 mg/kg/day of DEHP. At the end of the experiment, trace element and mineral levels, glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR) and glutathione S-transferase (GST) enzyme activities were evaluated in the serum, liver, and kidney samples of rats. Furthermore, serum clinical biochemistry parameters, organ/body weight ratios and histological changes were investigated to evaluate impact of DEHP more detailed. Our data indicated that sodium (Na), calcium (Ca), potassium (K), lithium (Li), rubidium (Rb) and cesium (Cs) levels significantly decreased, however iron (Fe) and selenium (Se) concentrations significantly increased in DEHP-administered groups compared to the control in the serum samples. On the other hand, upon DEHP administration, selenium concentration, G6PD and GR activities were significantly elevated, however 6-PGD activity significantly decreased compared to the control group in the kidney samples. Decreased G6PD activity was the only significant change between anti-oxidant enzyme activities in the liver samples. Upon DEHP administration, aberrant serum biochemical parameters have arisen and abnormal histological changes were observed in the kidney and liver tissue. In conclusion, DEHP may induce liver and kidney damage, also result abnormalities in the trace element and mineral levels.

Trace elements in two odontocete species (Kogia breviceps and Globicephala macrorhynchus) stranded in New Caledonia (South Pacific).

PubMed

Bustamante, P; Garrigue, C; Breau, L; Caurant, F; Dabin, W; Greaves, J; Dodemont, R

2003-01-01

Liver, muscle and blubber tissues of two short-finned pilot whales (Globicephala macrorhynchus) and two pygmy sperm whales(Kogia breviceps) stranded on the coast of New Caledonia have been analysed for 12 trace elements (Al, Cd, Co, Cr, Cu. Fe, organic and total Hg, Mn, Ni, Se, V, and Zn). Liver was shown to be the most important accumulating organ for Cd, Cu, Fe, Hg, Se, and Zn in both species, G. macrorhynchus having the highest Cd, Hg, Se and Zn levels. In this species, concentrations of total Hg are particularly elevated, reaching up to 1452 microg g(-1) dry wt. Only a very low percentage of the total Hg was organic. In both species,the levels of Hg are directly related to Se in liver. Thus, a molar ratio of Hg:Se close to 1.0 was found for all specimens, except for the youngest K. breviceps. Our results suggest that G. macrorhynchus have a physiology promoting the accumulation of high levels of naturally occurring toxic elements. Furthermore, concentrations of Ni, Cr and Co are close to or below the detection limit in the liver and muscles of all specimens. This suggests that mining activity in New Caledonia, which typically elevates the levels of these contaminants in the marine environment, does not seem to be a significant source of contamination for these pelagic marine mammals.

Effect of micromorphology of cortical bone tissue on crack propagation under dynamic loading

NASA Astrophysics Data System (ADS)

Wang, Mayao; Gao, Xing; Abdel-Wahab, Adel; Li, Simin; Zimmermann, Elizabeth A.; Riedel, Christoph; Busse, Björn; Silberschmidt, Vadim V.

2015-09-01

Structural integrity of bone tissue plays an important role in daily activities of humans. However, traumatic incidents such as sports injuries, collisions and falls can cause bone fracture, servere pain and mobility loss. In addition, ageing and degenerative bone diseases such as osteoporosis can increase the risk of fracture [1]. As a composite-like material, a cortical bone tissue is capable of tolerating moderate fracture/cracks without complete failure. The key to this is its heterogeneously distributed microstructural constituents providing both intrinsic and extrinsic toughening mechanisms. At micro-scale level, cortical bone can be considered as a four-phase composite material consisting of osteons, Haversian canals, cement lines and interstitial matrix. These microstructural constituents can directly affect local distributions of stresses and strains, and, hence, crack initiation and propagation. Therefore, understanding the effect of micromorphology of cortical bone on crack initiation and propagation, especially under dynamic loading regimes is of great importance for fracture risk evaluation. In this study, random microstructures of a cortical bone tissue were modelled with finite elements for four groups: healthy (control), young age, osteoporosis and bisphosphonate-treated, based on osteonal morphometric parameters measured from microscopic images for these groups. The developed models were loaded under the same dynamic loading conditions, representing a direct impact incident, resulting in progressive crack propagation. An extended finite-element method (X-FEM) was implemented to realize solution-dependent crack propagation within the microstructured cortical bone tissues. The obtained simulation results demonstrate significant differences due to micromorphology of cortical bone, in terms of crack propagation characteristics for different groups, with the young group showing highest fracture resistance and the senior group the lowest.

Multiscale smeared finite element model for mass transport in biological tissue: From blood vessels to cells and cellular organelles.

PubMed

Kojic, M; Milosevic, M; Simic, V; Koay, E J; Kojic, N; Ziemys, A; Ferrari, M

2018-05-21

One of the basic and vital processes in living organisms is mass exchange, which occurs on several levels: it goes from blood vessels to cells and organelles within cells. On that path, molecules, as oxygen, metabolic products, drugs, etc. Traverse different macro and micro environments - blood, extracellular/intracellular space, and interior of organelles; and also biological barriers such as walls of blood vessels and membranes of cells and organelles. Many aspects of this mass transport remain unknown, particularly the biophysical mechanisms governing drug delivery. The main research approach relies on laboratory and clinical investigations. In parallel, considerable efforts have been directed to develop computational tools for additional insight into the intricate process of mass exchange and transport. Along these lines, we have recently formulated a composite smeared finite element (CSFE) which is composed of the smeared continuum pressure and concentration fields of the capillary and lymphatic system, and of these fields within tissue. The element offers an elegant and simple procedure which opens up new lines of inquiry and can be applied to large systems such as organs and tumors models. Here, we extend this concept to a multiscale scheme which concurrently couples domains that span from large blood vessels, capillaries and lymph, to cell cytosol and further to organelles of nanometer size. These spatial physical domains are coupled by the appropriate connectivity elements representing biological barriers. The composite finite element has "degrees of freedom" which include pressures and concentrations of all compartments of the vessels-tissue assemblage. The overall model uses the standard, measurable material properties of the continuum biological environments and biological barriers. It can be considered as a framework into which we can incorporate various additional effects (such as electrical or biochemical) for transport through membranes or within cells. This concept and the developed FE software within our package PAK offers a computational tool that can be applied to whole-organ systems, while also including specific domains such as tumors. The solved examples demonstrate the accuracy of this model and its applicability to large biological systems. Copyright © 2018. Published by Elsevier Ltd.

Nanoscale quantification of intracellular element concentration by X-ray fluorescence microscopy combined with X-ray phase contrast nanotomography

NASA Astrophysics Data System (ADS)

Gramaccioni, Chiara; Yang, Yang; Procopio, Alessandra; Pacureanu, Alexandra; Bohic, Sylvain; Malucelli, Emil; Iotti, Stefano; Farruggia, Giovanna; Bukreeva, Inna; Notargiacomo, Andrea; Fratini, Michela; Valenti, Piera; Rosa, Luigi; Berlutti, Francesca; Cloetens, Peter; Lagomarsino, Stefano

2018-01-01

We present here a correlative X-ray microscopy approach for quantitative single cell imaging of molar concentrations. By combining the elemental content provided by X-ray fluorescence microscopy and the morphology information extracted from X-ray phase nanotomography, we determine the intracellular molarity distributions. This correlative method was demonstrated on a freeze-dried human phagocytic cell to obtain the absolute elemental concentration maps of K, P, and Fe. The cell morphology results showed a very good agreement with atomic-force microscopy measurements. This work opens the way for non-destructive single cell chemical analysis down to the sub-cellular level using exclusively synchrotron radiation techniques. It will be of high interest in the case where it is difficult to access the morphology using atomic-force microscopy, for example, on frozen-hydrated cells or tissues.

Detecting changes in the nutritional value and elemental composition of transgenic sorghum grain

NASA Astrophysics Data System (ADS)

Ndimba, R.; Grootboom, A. W.; Mehlo, L.; Mkhonza, N. L.; Kossmann, J.; Barnabas, A. D.; Mtshali, C.; Pineda-Vargas, C.

2015-11-01

We have previously demonstrated that poor digestibility in sorghum can be addressed by using RNA interference (RNAi) to suppress kafirin synthesis. The approach resulted in a twofold improvement in overall protein digestibility levels. In the present study, the effect of this targeted kafirin suppression on other grain quality parameters was investigated. Several significant changes in the proximate composition, amino acid profile and the bulk mineral content were detected. Importantly, the most limiting amino acid, lysine, was significantly increased in the transgenic grains by up to 39%; whilst mineral elements in the bulk, such as sulphur (S) and zinc (Zn) were reduced by up to 15.8% and 21% respectively. Elemental mapping of the grain tissue, using micro-PIXE, demonstrated a significant decrease in Zn (>75%), which was localised to the outer endosperm region, whilst TEM revealed important changes to the protein body morphology of the transgenic grains.

Impact of oral cadmium intoxication on levels of different essential trace elements and oxidative stress measures in mice: a response to dose.

PubMed

Kumar, Narendra; Kumari, Vandna; Ram, Chand; Bharath Kumar, Bagepalli Sathyanarayana; Verma, Sunita

2018-02-01

The study evaluated the effect of oral intoxication of cadmium and the possible causes of oxidative stress and its preferential accumulation in different organs as well as sub-sequential effects in mice. Twenty-four Swiss albino male mice were divided into three groups viz., normal control group without cadmium chloride (CdCl 2 ), whereas a daily dose of 0.5 and 1.2 mg of CdCl 2 was orally administered for a period of a week to dose group 1 (DG-1) and dose group 2 (DG-2), respectively. A significant increase in the severity of cadmium toxicity was observed in animals as evidenced by aggravation in liver enzymes viz., serum alanine aminotransferase and aspartate transaminase, whereas lower levels of antioxidative stress markers in liver and kidney tissues of treated mice were observed as compared to normal control group. A significant depletion of calcium levels in liver tissues of DG-1 (217.36 ± 1.73 μg/g of wet tissues) and DG-2 (186.41 ± 1.56 μg/g of wet tissues) groups, along with Cd accumulation, was observed. To summarize, the current study would increase our understanding with respect to dose-dependent absorption of Cd and its toxicity led to mortality as well as adverse health effects in the body of mice. Graphical abstract ᅟ.

Decreased expression of peroxisome proliferator activated receptor gamma in cftr-/- mice.

PubMed

Ollero, Mario; Junaidi, Omer; Zaman, Munir M; Tzameli, Iphigenia; Ferrando, Adolfo A; Andersson, Charlotte; Blanco, Paola G; Bialecki, Eldad; Freedman, Steven D

2004-08-01

Some of the pathological manifestations of cystic fibrosis are in accordance with an impaired expression and/or activity of PPARgamma. We hypothesized that PPARgamma expression is altered in tissues lacking the normal cystic fibrosis transmembrane regulator protein (CFTR). PPARgamma mRNA levels were measured in colonic mucosa, ileal mucosa, adipose tissue, lung, and liver from wild-type and cftr-/- mice by quantitative RT-PCR. PPARgamma expression was decreased twofold in CFTR-regulated tissues (colon, ileum, and lung) from cftr-/- mice compared to wild-type littermates. In contrast, no differences were found in fat and liver. Immunohistochemical analysis of PPARgamma in ileum and colon revealed a predominantly nuclear localization in wild-type mucosal epithelial cells while tissues from cftr-/- mice showed a more diffuse, lower intensity labeling. A significant decrease in PPARgamma expression was confirmed in nuclear extracts of colon mucosa by Western blot analysis. In addition, binding of the PPARgamma/RXR heterodimer to an oligonucletotide containing a peroxisome proliferator responsive element (PPRE) was also decreased in colonic mucosa extracts from cftr-/- mice. Treatment of cftr-/- mice with the PPARgamma ligand rosiglitazone restored both the nuclear localization and binding to DNA, but did not increase RNA levels. We conclude that PPARgamma expression in cftr-/- mice is downregulated at the RNA and protein levels and its function diminished. These changes may be related to the loss of function of CFTR and may be relevant to the pathogenesis of metabolic abnormalities associated with cystic fibrosis in humans. Copyright 2004 Wiley-Liss, Inc.

Role of extrinsic arbuscular mycorrhizal fungi in heavy metal-contaminated wetlands with various soil moisture levels.

PubMed

Zheng, S; Wang, C; Shen, Z; Quan, Y; Liu, X

2015-01-01

This study presents an efficient heavy metal (HM) control method in HM-contaminated wetlands with varied soil moisture levels through the introduction of extrinsic arbuscular mycorrhizal fungi (AMF) into natural wetland soil containing indigenous AMF species. A pot culture experiment was designed to determine the effect of two soil water contents (5-8% and 25-30%), five extrinsic AMF inoculants (Glomus mosseae, G. clarum, G. claroideum, G. etunicatum, and G. intraradices), and HM contamination on root colonization, plant growth, and element uptake of common reed (Phragmites australis (Cav.) Trin. ex Steudel) plantlets in wetland soils. This study showed the prevalence of mycorrhizae in the roots of all P. australis plantlets, regardless of extrinsic AMF inoculations, varied soil moisture or HM levels. It seems that different extrinsic AMF inoculations effectively lowered HM concentrations in the aboveground tissues of P. australis at two soil moisture levels. However, metal species, metal concentrations, and soil moisture should also be very important factors influencing the elemental uptake performance of plants in wetland ecosystems. Besides, the soil moisture level significantly influenced plant growth (including height, and shoot and root dry weight (DW)), and extrinsic AMF inoculations differently affected shoot DW.

Betaine Attenuates Alcohol-Induced Pancreatic Steatosis.

PubMed

Yang, Wenjuan; Gao, Jinhang; Tai, Yang; Chen, Meng; Huang, Luming; Wen, Shilei; Huang, Zhiyin; Liu, Rui; Li, Jing; Tang, Chengwei

2016-07-01

To explore the effect of betaine on alcoholic pancreatic steatosis and its mechanism. Rats were randomly assigned to control, ethanol, or ethanol + betaine groups. Changes in pancreatic morphology; serum lipid levels; and pancreatic lipid, amylase and lipase levels were determined. The serum and adipose tissue adiponectin level was measured by an enzyme-linked immunoassay. Adiponectin receptor-1 (AdipoR1), AdipoR2, sterol regulatory element binding protein-1c (SREBP-1c), SREBP-2, and fatty acid synthetase expression levels were quantified. The SREBP-1c expression in SW1990 cells treated with various concentrations of ethanol or ethanol plus betaine and/or adiponectin was assessed. Alcohol-induced changes in pancreatic morphology were attenuated by betaine. Pancreatic triglyceride, free fatty acid and expression levels of SREBP-1c and fatty acid synthetase were elevated after ethanol feeding but remained at control levels after betaine supplementation. Alcohol-induced decreases in serum and adipose tissue adiponectin, pancreatic AdipoR1, amylase, and lipase were attenuated by betaine. Serum triglyceride and free fatty acid levels were elevated after alcohol consumption and remained higher after betaine supplementation compared with controls. Betaine and/or adiponectin suppressed alcohol-induced SREBP-1c upregulation in vitro. Betaine attenuated alcoholic-induced pancreatic steatosis most likely by suppressing pancreatic SREBP-1c both directly and through the restoration of adiponectin signaling.

Abnormal chemical element concentrations in lichens of Isle Royale National Park

USGS Publications Warehouse

Bennett, J.P.

1995-01-01

Lichens have been used for many years to monitor changes in deposited airborne chemical elements in many areas, but few studies have focused on areas suspected of experiencing slightly elevated pollution. Detection of subtle patterns of slightly elevated pollutants calls for developing several lines of evidence as opposed to single line studies used in heavily polluted areas. This study of two lichen species, Hypogymnia physodes and Evernia mesomorpha, in Isle Royale National Park, Michigan compares the concentrations and ranks of elements with the concentrations and ranks of the elements in the earth's crust, changes in element concentrations over a nine year period, and the geography of element concentrations in the park. S, Zn, Pb, Cd and Se were elevated in both species and higher in rank compared to the concentrations and ranks in the earth's crust. Toxic elements increased 123% in Hypogymnia and 62% in Evernia over 9 years, compared to increases of 45% and 59% for non-toxic elements in each species, respectively. Geographically, the lichens at certain localities with higher exposures experienced higher than average element concentrations. Finally, tissue concentrations of Mn, S and Se at some localities were above levels known to be either toxic or similar to those found in polluted areas. These four lines of evidence suggest that Isle Royale National Park is experiencing the onset of chronic air pollution stress from a number of sources.

Variation in Macro and Trace Elements in Progression of Type 2 Diabetes

PubMed Central

2014-01-01

Macro elements are the minerals of which the body needs more amounts and are more important than any other elements. Trace elements constitute a minute part of the living tissues and have various metabolic characteristics and functions. Trace elements participate in tissue and cellular and subcellular functions; these include immune regulation by humoral and cellular mechanisms, nerve conduction, muscle contractions, membrane potential regulations, and mitochondrial activity and enzyme reactions. The status of micronutrients such as iron and vanadium is higher in type 2 diabetes. The calcium, magnesium, sodium, chromium, cobalt, iodine, iron, selenium, manganese, and zinc seem to be low in type 2 diabetes while elements such as potassium and copper have no effect. In this review, we emphasized the status of macro and trace elements in type 2 diabetes and its advantages or disadvantages; this helps to understand the mechanism, progression, and prevention of type 2 diabetes due to the lack and deficiency of different macro and trace elements. PMID:25162051

Electrostatic, elastic and hydration-dependent interactions in dermis influencing volume exclusion and macromolecular transport.

PubMed

Øien, Alf H; Wiig, Helge

2016-07-07

Interstitial exclusion refers to the limitation of space available for plasma proteins and other macromolecules based on collagen and negatively charged glycosaminoglycans (GAGs) in the interstitial space. It is of particular importance to interstitial fluid and plasma volume regulation. Here we present a novel mechanical and mathematical model of the dynamic interactions of structural elements within the interstitium of the dermis at the microscopic level that may explain volume exclusion of charged and neutral macroparticles. At this level, the interstitium is considered to consist of elements called extracellular matrix (ECM) cells, again containing two main interacting structural components on a fluid background including anions and cations setting up osmotic forces: one smaller GAG component, having an intrinsic expansive electric force, and one bigger collagen component, having an intrinsic elastic force. Because of size differences, the GAG component interacts with a fraction of the collagen component only at normal hydration. This fraction, however, increases with rising hydration as a consequence of the modeled form of the interaction force between the GAGs and collagen. Collagen is locally displaced at variable degrees as hydration changes. Two models of GAGs are considered, having largely different geometries which demands different, but related, forms of GAG-collagen interaction forces. The effects of variable fixed charges on GAGs and of GAG density in tissue are evaluated taking into account observed volume exclusion properties of charged macromolecules as a function of tissue hydration. The presented models may improve our biophysical understanding of acting forces influencing tissue fluid dynamics. Such knowledge is significant when evaluating the transport of electrically charged and neutral macromolecules into and through the interstitium, and therefore to drug uptake and the therapeutic effects of macromolecular agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mineralization, watershed geochemistry, and metals in fish from a Subarctic River, Alaska

USGS Publications Warehouse

Gough, L.P.; Wang, B.; Crock, J.G.; Seal, R.R.; Weber-Scannell, P.

2005-01-01

We report on the levels of trace metals and metalloids in Arctic grayling (Thymallus arcticus), an important freshwater sport and subsistence fish in the Fortymile River, east-central Alaska. Functional biogeochemical baseline values and (or) ranges are presented for 38 major- and trace-elements in the muscle (fillet) and liver of 34 fish collected from 11 sampling sites in the watershed. In addition, we present N-, C-, and S-isotopic data for muscle samples. These data are the first to be reported for Arctic grayling in this region of Alaska. Geometric means for total Hg in muscle and liver tissue are 0.069 and 0.062 ppm, respectively. These levels are more than an order of magnitude below the FDA permissible value for methylmercury in fish fillets. In general, we noted little variation in the elemental concentrations in muscle tissue among samples at each of the 11 fish-sampling sites. No definitive link could be attributed between biogeochemical patterns and regional lithology. Stomach-content chemistry varied widely (relative muscle tissue or liver) and generally reflected sediment chemistry - a component of the ingested material. Stomach-content material was examined for the occurrence and frequency of macroinvertebrates and their chemical composition in three fish. Results showed considerable diversity, with 9 to 15 invertebrate taxa of which both aquatic and terrestrial individuals were found. The N-isotopic compositions of muscle fillet samples are homogeneous (??15N = 7.6 - 9.7 permil), reflecting a restricted, low trophic (primary predator) position for the grayling. C and S isotopic compositions (??13C and ??34S) of fillet samples range from -33.1 to -25.8 permil and -8.4 to 8.2 permil, respectively, suggesting heterogeneity of food sources (both aquatic and terrestrial). Copyright ASCE 2005.

The influence of curcumin and manganese complex of curcumin on cadmium-induced oxidative damage and trace elements status in tissues of mice.

PubMed

Eybl, Vladislav; Kotyzová, Dana; Lesetický, Ladislav; Bludovská, Monika; Koutenský, Jaroslav

2006-01-01

Curcumin (diferuoyl methane) from turmeric is a well-known biologically active compound. It has been shown to ameliorate oxidative stress and it is considered to be a potent cancer chemopreventive agent. In our previous study the antioxidative effects of curcumin in cadmium exposed animals were demonstrated. Also manganese exerts protective effects in experimental cadmium intoxication. The present study examined the ability of the manganese complex of curcumin (Mn-curcumin) and curcumin to protect against oxidative damage and changes in trace element status in cadmium-intoxicated male mice. Curcumin or Mn-curcumin were administered at equimolar doses (0.14 mmol/kg b.w.) for 3 days, by gastric gavages, dispersed in methylcellulose. One hour after the last dose of antioxidants, cadmium chloride (33 micromol/kg) was administered subcutaneously. Both curcumin and Mn-curcumin prevented the increase of hepatic lipid peroxidation -- expressed as MDA level, induced by cadmium intoxication and attenuated the Cd-induced decrease of hepatic GSH level. No change in hepatic glutathione peroxidase or catalase activities was found in Cd-exposed mice. A decreased GSH-Px activity was measured in curcumin and Mn-curcumin alone treated mice. Neither curcumin nor Mn-curcumin treatment influenced cadmium distribution in the tissues and did not correct the changes in the balance of essential elements caused by Cd-treatment. The treatment with Mn-curcumin increased the Fe and Mn content in the kidneys of both control and Cd-treated mice and Fe and Cu content in the brain of control mice. In conclusion, regarding the antioxidative action, introducing manganese into the curcumin molecule does not potentiate the studied effects of curcumin. Copyright 2006 John Wiley & Sons, Ltd.

Repositioning the knee joint in human body FE models using a graphics-based technique.

PubMed

Jani, Dhaval; Chawla, Anoop; Mukherjee, Sudipto; Goyal, Rahul; Vusirikala, Nataraju; Jayaraman, Suresh

2012-01-01

Human body finite element models (FE-HBMs) are available in standard occupant or pedestrian postures. There is a need to have FE-HBMs in the same posture as a crash victim or to be configured in varying postures. Developing FE models for all possible positions is not practically viable. The current work aims at obtaining a posture-specific human lower extremity model by reconfiguring an existing one. A graphics-based technique was developed to reposition the lower extremity of an FE-HBM by specifying the flexion-extension angle. Elements of the model were segregated into rigid (bones) and deformable components (soft tissues). The bones were rotated about the flexion-extension axis followed by rotation about the longitudinal axis to capture the twisting of the tibia. The desired knee joint movement was thus achieved. Geometric heuristics were then used to reposition the skin. A mapping defined over the space between bones and the skin was used to regenerate the soft tissues. Mesh smoothing was then done to augment mesh quality. The developed method permits control over the kinematics of the joint and maintains the initial mesh quality of the model. For some critical areas (in the joint vicinity) where element distortion is large, mesh smoothing is done to improve mesh quality. A method to reposition the knee joint of a human body FE model was developed. Repositions of a model from 9 degrees of flexion to 90 degrees of flexion in just a few seconds without subjective interventions was demonstrated. Because the mesh quality of the repositioned model was maintained to a predefined level (typically to the level of a well-made model in the initial configuration), the model was suitable for subsequent simulations.

Accumulation of contaminants in fish from wastewater treatment wetlands

USGS Publications Warehouse

Barber, L.B.; Keefe, S.H.; Antweiler, Ronald C.; Taylor, Howard E.; Wass, R.D.

2006-01-01

Increasing demands on water resources in arid environments make reclamation and reuse of municipal wastewater an important component of the water budget. Treatment wetlands can be an integral part of the water-reuse cycle providing both water-quality enhancement and habitat functions. When used for habitat, the bioaccumulation potential of contaminants in the wastewater is a critical consideration. Water and fish samples collected from the Tres Rios Demonstration Constructed Wetlands near Phoenix, Arizona, which uses secondary-treated wastewater to maintain an aquatic ecosystem in a desert environment, were analyzed for hydrophobic organic compounds (HOC) and trace elements. Semipermeable membrane devices (SPMD) were deployed to investigate uptake of HOC. The wetlands effectively removed HOC, and concentrations of herbicides, pesticides, and organic wastewater contaminants decreased 40-99% between inlet and outlet. Analysis of Tilapia mossambica and Gambusia affinis indicated accumulation of HOC, including p,p???-DDE and trans-nonachlor. The SPMD accumulated the HOC detected in the fish tissue as well as additional compounds. Trace-element concentrations in whole-fish tissue were highly variable, but were similar between the two species. Concentrations of HOC and trace elements varied in different fish tissue compartments, and concentrations in Tilapia liver tissue were greater than those in the whole organism or filet tissue. Bioconcentration factors for the trace elements ranged from 5 to 58 000 and for the HOC ranged from 530 to 150 000. ?? 2006 American Chemical Society.

[Synthesis of strontium-containing porous hydroxyaptite ceramics and study of its biological properties].

PubMed

Zou, Wen; Ran, Xu; Liang, Jie; Chen, Hezhong; Luo, Jiaoming

2012-12-01

Strontium added into porous hydroxyaptite ceramics has the functions of improving its osseointegration, decreasing its dissolution rate and improving the bone density. Strontium-containing hydroxyaptite (Sr-HA) ceramics has been used as bone replacement and scaffold to treat the osteoporosis and bone default in clinic, but the mechanism of interfacial tissue response caused by the trace element Sr in Sr-HA ceramics still remains to be further studied. Four types of Sr-HA ceramic samples with different contents of Sr were prepared by microwave plasma sintering for testing the response of the soft tissue implanted in dog muscles in our laboratory. The contents of Sr element in the samples are 0 mol%, 1 mol%, 5 mol%, and 7 mol%, respectively. The samples were implanted in the muscle of the dogs for 4 weeks, 8 weeks and 12 weeks, respectively. The histological observations at the end of each period showed that the irritant ranking increased with the content of Sr in Sr-HA ceramics at the end of 12 weeks, and there were rich bone tissue in Sr-HA ceramic samples with 5 mol% Sr element. The overdose of element Sr is harmful to soft tissues. When the content of Sr in Sr-HA ceramic was below 5 mol%, the soft tissue response was very slight and the new bones were induced to grow well.

Gold internal standard correction for elemental imaging of soft tissue sections by LA-ICP-MS: element distribution in eye microstructures.

PubMed

Konz, Ioana; Fernández, Beatriz; Fernández, M Luisa; Pereiro, Rosario; González, Héctor; Alvarez, Lydia; Coca-Prados, Miguel; Sanz-Medel, Alfredo

2013-04-01

Laser ablation coupled to inductively coupled plasma mass spectrometry has been developed for the elemental imaging of Mg, Fe and Cu distribution in histological tissue sections of fixed eyes, embedded in paraffin, from human donors (cadavers). This work presents the development of a novel internal standard correction methodology based on the deposition of a homogeneous thin gold film on the tissue surface and the use of the (197)Au(+) signal as internal standard. Sample preparation (tissue section thickness) and laser conditions were carefully optimized, and internal normalisation using (197)Au(+) was compared with (13)C(+) correction for imaging applications. (24)Mg(+), (56)Fe(+) and (63)Cu(+) distributions were investigated in histological sections of the anterior segment of the eye (including the iris, ciliary body, cornea and trabecular meshwork) and were shown to be heterogeneously distributed along those tissue structures. Reproducibility was assessed by imaging different human eye sections from the same donor and from ten different eyes from adult normal donors, which showed that similar spatial maps were obtained and therefore demonstrate the analytical potential of using (197)Au(+) as internal standard. The proposed analytical approach could offer a robust tool with great practical interest for clinical studies, e.g. to investigate trace element distribution of metals and their alterations in ocular diseases.

Content and distribution of macro- and micro-elements in the body of pasture-fed young horses.

PubMed

Grace, N D; Pearce, S G; Firth, E C; Fennessy, P F

1999-03-01

To determine the content and distribution of Na, K, Ca, P, Mg, S, Cu, Mn, Fe and Zn in the body of pasture-fed young horses and then use a factorial model to calculate the dietary mineral requirements for growth. Twenty-one foals were killed at about 150 days of age and the organs, soft tissues, skin and bones and a sample of muscle were dissected out and weighted. The mineral concentrations of elements in all soft tissues and bones were measured by inductively coupled emission spectrometry. The total mineral element composition associated with a tissue was determined from the weight of tissue and its mineral element concentration. Expressed as a percent of total body mineral elements, muscle contained 20% Na, 78% K, 32% Mg, 62% Cu, 36% Mn and 57% Zn, bone contained 47% Na, 99% Ca, 81% P, 62% Mg, 30% Mn and 28% Zn while the organs accounted for a smaller percentage ranging from 0.06% for Ca to 26% for Fe. In liver Cu accounted for 9.2% of total body Cu. Each kilogram of empty body weight was associated with 1.0 g Na, 2.5 g K, 17.1 g Ca, 10.1 g P, 0.4 g Mg, 1.1 mg Cu, 0.39 mg Mn, 52.5 mg Fe and 21.4 mg Zn. The mineral element content of body weight gain is a component used in the factorial model to determine dietary mineral element requirements for growth. The calculated dietary mineral requirements, expressed per kg dry matter, for a 200 kg horse gaining 1.0 kg/day were 1.0 g Na, 2.1 g K, 4.6 g Ca, 3.5 g P, 0.7 g Mg, 4.5 mg Cu and 25 mg Zn.

Mineral density volume gradients in normal and diseased human tissues

DOE PAGES

Djomehri, Sabra I.; Candell, Susan; Case, Thomas; ...

2015-04-09

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

Mineral density volume gradients in normal and diseased human tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djomehri, Sabra I.; Candell, Susan; Case, Thomas

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

Mineral density volume gradients in normal and diseased human tissues.

PubMed

Djomehri, Sabra I; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W; Yun, Wenbing; Lau, S H; Webb, Samuel; Ho, Sunita P

2015-01-01

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095 mg/cc, bone: 570-1415 mg/cc, cementum: 1240-1340 mg/cc, dentin: 1480-1590 mg/cc, cementum affected by periodontitis: 1100-1220 mg/cc, hypomineralized carious dentin: 345-1450 mg/cc, hypermineralized carious dentin: 1815-2740 mg/cc, and dental calculus: 1290-1770 mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.

Mineral Density Volume Gradients in Normal and Diseased Human Tissues

PubMed Central

Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.

2015-01-01

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations. PMID:25856386

The alteration of interelemental ratios in myocardium under the congenital heart disease (SRXRF)

NASA Astrophysics Data System (ADS)

Trunova, V. A.; Zvereva, V. V.; Okuneva, G. N.; Levicheva, E. N.

2007-05-01

It is the myocardium that bears the basic functional loading during heart working, including muscle contractility and enzyme activity. The elemental concentrations in myocardium tissue of heart were determined by SRXRF technique. Our investigation is systematical: the elemental content in each compartment (left and right ventricles, left and right auricles) of hearts of healthy and diseased children (congenital heart diseases, transposition of main vessels (TMV)) was analyzed. The elemental distribution in myocardium of four heart chambers of human fetuses was also analyzed. Following elements were determined: S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr. It was revealed that the elemental concentrations in myocardium of both ventricles are almost constant in heart of fetuses and healthy children. The transition from pre-natal study (fetus) to post-natal study is accompanied by the redistribution of chemical elements in myocardium. The higher concentrations of S, Fe, Ca, Sr and Cu in myocardium of children are observed, the content of K, Br, Rb and especially Se is lower than in heart of fetuses. The elemental distribution in myocardium of children TMV is considerably different in comparison with the healthy children: the higher levels of Cu are observed. The content of Se is lower.

Elements of the niche for adult stem cell expansion

PubMed Central

Redondo, Patricia A; Pavlou, Marina; Loizidou, Marilena; Cheema, Umber

2017-01-01

Adult stem cells are crucial for tissue homeostasis. These cells reside within exclusive locations in tissues, termed niches, which protect adult stem cell fidelity and regulate their many functions through biophysical-, biochemical- and cellular-mediated mechanisms. There is a growing understanding of how these mechanisms and their components contribute towards maintaining stem cell quiescence, self-renewal, expansion and differentiation patterns. In vitro expansion of adult stem cells is a powerful tool for understanding stem cell biology, and for tissue engineering and regenerative medicine applications. However, it is technically challenging, since adult stem cell removal from their native microenvironment has negative repercussions on their sustainability. In this review, we overview specific elements of the biomimetic niche and how recreating such elements can help in vitro propagation of adult stem cells. PMID:28890779

Elements of the niche for adult stem cell expansion.

PubMed

Redondo, Patricia A; Pavlou, Marina; Loizidou, Marilena; Cheema, Umber

2017-01-01

Adult stem cells are crucial for tissue homeostasis. These cells reside within exclusive locations in tissues, termed niches, which protect adult stem cell fidelity and regulate their many functions through biophysical-, biochemical- and cellular-mediated mechanisms. There is a growing understanding of how these mechanisms and their components contribute towards maintaining stem cell quiescence, self-renewal, expansion and differentiation patterns. In vitro expansion of adult stem cells is a powerful tool for understanding stem cell biology, and for tissue engineering and regenerative medicine applications. However, it is technically challenging, since adult stem cell removal from their native microenvironment has negative repercussions on their sustainability. In this review, we overview specific elements of the biomimetic niche and how recreating such elements can help in vitro propagation of adult stem cells.

Dehomogenized Elastic Properties of Heterogeneous Layered Materials in AFM Indentation Experiments.

PubMed

Lee, Jia-Jye; Rao, Satish; Kaushik, Gaurav; Azeloglu, Evren U; Costa, Kevin D

2018-06-05

Atomic force microscopy (AFM) is used to study mechanical properties of biological materials at submicron length scales. However, such samples are often structurally heterogeneous even at the local level, with different regions having distinct mechanical properties. Physical or chemical disruption can isolate individual structural elements but may alter the properties being measured. Therefore, to determine the micromechanical properties of intact heterogeneous multilayered samples indented by AFM, we propose the Hybrid Eshelby Decomposition (HED) analysis, which combines a modified homogenization theory and finite element modeling to extract layer-specific elastic moduli of composite structures from single indentations, utilizing knowledge of the component distribution to achieve solution uniqueness. Using finite element model-simulated indentation of layered samples with micron-scale thickness dimensions, biologically relevant elastic properties for incompressible soft tissues, and layer-specific heterogeneity of an order of magnitude or less, HED analysis recovered the prescribed modulus values typically within 10% error. Experimental validation using bilayer spin-coated polydimethylsiloxane samples also yielded self-consistent layer-specific modulus values whether arranged as stiff layer on soft substrate or soft layer on stiff substrate. We further examined a biophysical application by characterizing layer-specific microelastic properties of full-thickness mouse aortic wall tissue, demonstrating that the HED-extracted modulus of the tunica media was more than fivefold stiffer than the intima and not significantly different from direct indentation of exposed media tissue. Our results show that the elastic properties of surface and subsurface layers of microscale synthetic and biological samples can be simultaneously extracted from the composite material response to AFM indentation. HED analysis offers a robust approach to studying regional micromechanics of heterogeneous multilayered samples without destructively separating individual components before testing. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Patient-specific in silico models can quantify primary implant stability in elderly human bone.

PubMed

Steiner, Juri A; Hofmann, Urs A T; Christen, Patrik; Favre, Jean M; Ferguson, Stephen J; van Lenthe, G Harry

2018-03-01

Secure implant fixation is challenging in osteoporotic bone. Due to the high variability in inter- and intra-patient bone quality, ex vivo mechanical testing of implants in bone is very material- and time-consuming. Alternatively, in silico models could substantially reduce costs and speed up the design of novel implants if they had the capability to capture the intricate bone microstructure. Therefore, the aim of this study was to validate a micro-finite element model of a multi-screw fracture fixation system. Eight human cadaveric humerii were scanned using micro-CT and mechanically tested to quantify bone stiffness. Osteotomy and fracture fixation were performed, followed by mechanical testing to quantify displacements at 12 different locations on the instrumented bone. For each experimental case, a micro-finite element model was created. From the micro-finite element analyses of the intact model, the patient-specific bone tissue modulus was determined such that the simulated apparent stiffness matched the measured stiffness of the intact bone. Similarly, the tissue modulus of a small damage region around each screw was determined for the instrumented bone. For validation, all in silico models were rerun using averaged material properties, resulting in an average coefficient of determination of 0.89 ± 0.04 with a slope of 0.93 ± 0.19 and a mean absolute error of 43 ± 10 μm when correlating in silico marker displacements with the ex vivo test. In conclusion, we validated a patient-specific computer model of an entire organ bone-implant system at the tissue-level at high resolution with excellent overall accuracy. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:954-962, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Evaluation of Tissue Interactions with Mechanical Elements of a Transscleral Drug Delivery Device

PubMed Central

Cohen, Sarah J.; Chan, Robison V. Paul; Keegan, Mark; Andreoli, Christopher M.; Borenstein, Jeffrey T.; Miller, Joan W.; Gragoudas, Evangelos S.

2012-01-01

The goal of this work was to evaluate tissue-device interactions due to implantation of a mechanically operated drug delivery system onto the posterior sclera. Two test devices were designed and fabricated to model elements of the drug delivery device—one containing a free-spinning ball bearing and the other encasing two articulating gears. Openings in the base of test devices modeled ports for drug passage from device to sclera. Porous poly(tetrafluoroethylene) (PTFE) membranes were attached to half of the gear devices to minimize tissue ingrowth through these ports. Test devices were sutured onto rabbit eyes for 10 weeks. Tissue-device interactions were evaluated histologically and mechanically after removal to determine effects on device function and changes in surrounding tissue. Test devices were generally well-tolerated during residence in the animal. All devices encouraged fibrous tissue formation between the sclera and the device, fibrous tissue encapsulation and invasion around the device, and inflammation of the conjunctiva. Gear devices encouraged significantly greater inflammation in all cases and a larger rate of tissue ingrowth. PTFE membranes prevented tissue invasion through the covered drug ports, though tissue migrated in through other smaller openings. The torque required to turn the mechanical elements increased over 1000 times for gear devices, but only on the order of 100 times for membrane-covered gear devices and less than 100 times for ball bearing devices. Maintaining a lower device profile, minimizing microscale motion on the eye surface and covering drug ports with a porous membrane may minimize inflammation, decreasing the risk of damage to surrounding tissues and minimizing disruption of device operation. PMID:24300189

Music acquisition: effects of enculturation and formal training on development.

PubMed

Hannon, Erin E; Trainor, Laurel J

2007-11-01

Musical structure is complex, consisting of a small set of elements that combine to form hierarchical levels of pitch and temporal structure according to grammatical rules. As with language, different systems use different elements and rules for combination. Drawing on recent findings, we propose that music acquisition begins with basic features, such as peripheral frequency-coding mechanisms and multisensory timing connections, and proceeds through enculturation, whereby everyday exposure to a particular music system creates, in a systematic order of acquisition, culture-specific brain structures and representations. Finally, we propose that formal musical training invokes domain-specific processes that affect salience of musical input and the amount of cortical tissue devoted to its processing, as well as domain-general processes of attention and executive functioning.

A composite smeared finite element for mass transport in capillary systems and biological tissue.

PubMed

Kojic, M; Milosevic, M; Simic, V; Koay, E J; Fleming, J B; Nizzero, S; Kojic, N; Ziemys, A; Ferrari, M

2017-09-01

One of the key processes in living organisms is mass transport occurring from blood vessels to tissues for supplying tissues with oxygen, nutrients, drugs, immune cells, and - in the reverse direction - transport of waste products of cell metabolism to blood vessels. The mass exchange from blood vessels to tissue and vice versa occurs through blood vessel walls. This vital process has been investigated experimentally over centuries, and also in the last decades by the use of computational methods. Due to geometrical and functional complexity and heterogeneity of capillary systems, it is however not feasible to model in silico individual capillaries (including transport through the walls and coupling to tissue) within whole organ models. Hence, there is a need for simplified and robust computational models that address mass transport in capillary-tissue systems. We here introduce a smeared modeling concept for gradient-driven mass transport and formulate a new composite smeared finite element (CSFE). The transport from capillary system is first smeared to continuous mass sources within tissue, under the assumption of uniform concentration within capillaries. Here, the fundamental relation between capillary surface area and volumetric fraction is derived as the basis for modeling transport through capillary walls. Further, we formulate the CSFE which relies on the transformation of the one-dimensional (1D) constitutive relations (for transport within capillaries) into the continuum form expressed by Darcy's and diffusion tensors. The introduced CSFE is composed of two volumetric parts - capillary and tissue domains, and has four nodal degrees of freedom (DOF): pressure and concentration for each of the two domains. The domains are coupled by connectivity elements at each node. The fictitious connectivity elements take into account the surface area of capillary walls which belongs to each node, as well as the wall material properties (permeability and partitioning). The overall FE model contains geometrical and material characteristics of the entire capillary-tissue system, with physiologically measurable parameters assigned to each FE node within the model. The smeared concept is implemented into our implicit-iterative FE scheme and into FE package PAK. The first three examples illustrate accuracy of the CSFE element, while the liver and pancreas models demonstrate robustness of the introduced methodology and its applicability to real physiological conditions.

Determination of elemental tissue composition following proton treatment using positron emission tomography

NASA Astrophysics Data System (ADS)

Cho, Jongmin; Ibbott, Geoffrey; Gillin, Michael; Gonzalez-Lepera, Carlos; Min, Chul Hee; Zhu, Xuping; El Fakhri, Georges; Paganetti, Harald; Mawlawi, Osama

2013-06-01

Positron emission tomography (PET) has been suggested as an imaging technique for in vivo proton dose and range verification after proton induced-tissue activation. During proton treatment, irradiated tissue is activated and decays while emitting positrons. In this paper, we assessed the feasibility of using PET imaging after proton treatment to determine tissue elemental composition by evaluating the resultant composite decay curve of activated tissue. A phantom consisting of sections composed of different combinations of 1H, 12C, 14N, and 16O was irradiated using a pristine Bragg peak and a 6 cm spread-out Bragg-peak (SOBP) proton beam. The beam ranges defined at 90% distal dose were 10 cm the delivered dose was 1.6 Gy for the near monoenergetic beam and 2 Gy for the SOBP beam. After irradiation, activated phantom decay was measured using an in-room PET scanner for 30 min in list mode. Decay curves from the activated 12C and 16O sections were first decomposed into multiple simple exponential decay curves, each curve corresponding to a constituent radioisotope, using a least-squares method. The relative radioisotope fractions from each section were determined. These fractions were used to guide the decay curve decomposition from the section consisting mainly of 12C + 16O and calculate the relative elemental composition of 12C and 16O. A Monte Carlo simulation was also used to determine the elemental composition of the 12C + 16O section. The calculated compositions of the 12C + 16O section using both approaches (PET and Monte Carlo) were compared with the true known phantom composition. Finally, two patients were imaged using an in-room PET scanner after proton therapy of the head. Their PET data and the technique described above were used to construct elemental composition (12C and 16O) maps that corresponded to the proton-activated regions. We compared the 12C and 16O compositions of seven ROIs that corresponded to the vitreous humor, adipose/face mask, adipose tissue, and brain tissue with ICRU 46 elemental composition data. The 12C and 16O compositions of the 12C + 16O phantom section were estimated to within a maximum difference of 3.6% for the near monoenergetic and SOBP beams over an 8 cm depth range. On the other hand, the Monte Carlo simulation estimated the corresponding 12C and 16O compositions in the 12C + 16O section to within a maximum difference of 3.4%. For the patients, the 12C and 16O compositions in the seven ROIs agreed with the ICRU elemental composition data, with a mean (maximum) difference of 9.4% (15.2%). The 12C and 16O compositions of the phantom and patients were estimated with relatively small differences. PET imaging may be useful for determining the tissue elemental composition and thereby improving proton treatment planning and verification.

Heavy metal concentrations in commercial deep-sea fish from the Rockall Trough

NASA Astrophysics Data System (ADS)

Mormede, S.; Davies, I. M.

2001-05-01

Samples of monkfish ( Lophius piscatorius), black scabbard ( Aphanopus carbo), blue ling ( Molva dypterygia), blue whiting ( Micromesistius poutassou) and hake ( Merluccius merluccius) were obtained from 400 to 1150 m depth on the continental slope of Rockall Trough west of Scotland. Muscle, liver, gill and gonad tissue were analysed for arsenic, cadmium, copper, lead, mercury and zinc by various atomic absorption techniques. Median concentrations of arsenic in the muscle tissue ranged from 1.25 to 8.63 mg/kg wet weight; in liver tissue from 3.04 to 5.72 mg/kg wet weight; cadmium in muscle tissue from <0.002 to 0.034 mg/kg wet weight, in liver tissue from 0.11 to 6.98 mg/kg wet weight; copper in the muscle from 0.12 to 0.29 mg/kg wet weight, in the liver from 3.47 to 11.87 mg/kg wet weight; lead levels in muscle from <0.002 to 0.009 mg/kg wet weight, respectively, and in liver tissue <0.05 mg/kg wet weight for all species. In general, the concentrations are similar to those previously published on deep-sea fish, and higher or similar to those published for shallow water counterparts. All metal levels in black scabbard livers are much higher than in the other fish, and between 2 and 30 times higher than the limits of the European Dietary Standards and Guidelines. Differences in accumulation patterns between species and elements, as well as between organs are described using univariate and multivariate statistics (scatterplots, discriminant analysis, triangular plots).

Aberrant Expression of PIWIL1 and PIWIL2 and Their Clinical Significance in Ductal Breast Carcinoma.

PubMed

Litwin, Monika; Szczepańska-Buda, Anna; Michałowska, Dagmara; Grzegrzółka, Jędrzej; Piotrowska, Aleksandra; Gomułkiewicz, Agnieszka; Wojnar, Andrzej; Dzięgiel, Piotr; Witkiewicz, Wojciech

2018-04-01

P-Element-induced wimpy testis (PIWI) proteins in complex with PIWI-interacting RNA (piRNA) are involved in epigenetic regulation of gene expression in germline cells. Aberrant expression of piRNA and PIWI proteins have been identified in various types of tumour cells. The aim of this study was to evaluate the expression profiles of PIWI-like protein-1, -2 (PIWIL1 and PIWIL2), their immunohistochemical (IHC) characteristics in ductal breast cancer, and determine their correlation with clinicopathological parameters of this type of cancer. Material for IHC studies comprised of 101 invasive ductal carcinoma (IDC) cases and 31 mastopathy tissues. Frozen fragments of paired tissue specimens (tumour and adjacent non-malignant breast tissue) taken from 55 patients with IDC and 18 samples of mastopathy were used for molecular studies using real-time polymerase chain reaction (RT-PCR). A statistically significantly higher level of PIWIL1 and PIWIL2 was found in IDC compared to mastopathy samples (p≤0.0001). Increased expression of PIWIL1 was correlated with increased PIWIL2 expression in breast cancer tissue. Surprisingly, PIWIL1 mRNA was detected only in cancer and mastopathy, but was not found in most normal breast tissues, although it is noteworthy that the PIWIL2 mRNA level was statistically significantly lower in mastopathy and IDC samples compared to normal breast tissues. Our results affirm the hypothesis that reactivation of PIWI expression in various caner types is crucial for cancer development. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The effects of dissecting tools on the trace element concentrations of fish and mussel tissues.

PubMed

Heit, M; Klusek, C S

1982-06-01

A comparison of the effects of dissecting tools composed of various materials on the trace element content of the muscle of the marine bluefish, Pomatomus saltatrix, and the soft tissues of freshwater mussels, Eliptio complanatus and Lampsilus radiata, is presented. The fish were dissected with blades made of stainless steel, Lexan plastic, titanium, and Teflon-coated stainless steel. The mussels were dissected with stainless and Teflon tools only. Elements measured included As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Sn, Te, V, and Zn. Significant concentration differences (P = 0.01) were not found for any element in fish or mussel samples dissected by the different tools.

Opportunities for Improvement in Pathology Reporting of Childhood Nonrhabdomyosarcoma Soft Tissue Sarcomas:  A Report From Children's Oncology Group (COG) Study ARST0332.

PubMed

Black, Jennifer O; Coffin, Cheryl M; Parham, David M; Hawkins, Douglas S; Speights, Rose A; Spunt, Sheri L

2016-09-01

Treatment of soft tissue tumors in young patients relies on the diagnostic information conveyed in the pathology report. We examined pathology reports from Children's Oncology Group ARST0332 for inclusion of data elements required in published guidelines. Pathology reports for 551 eligible patients were examined for required data elements defined by the College of American Pathologists, including tissue type, procedure, tumor site, tumor maximum diameter, macroscopic extent of tumor, histologic type, mitotic rate, extent of necrosis, tumor grade, margin status, use of ancillary studies, and pathologic stage. Only 65 (12%) of 551 reports included all required data elements. Of reports containing synoptic templates, 57% were complete. This study reveals significant opportunity to improve the quality of pathology reports in young patients with soft tissue tumors. Use of templates or checklists improves completeness of reports. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A potential dating technique using 228Th/228Ra ratio for tracing the chronosequence of elemental concentrations in plants.

PubMed

Chao, J H; Niu, H; Chiu, C Y; Lin, C

2007-06-01

We propose a radiometric method based on measurement of the radioactivity of the naturally occurring radionuclides (228)Ra and 228)Th and the derived (228)Th/(228)Ra ratios in plant samples to estimate plant age and the corresponding nutritional conditions in a field-growing fern, Dicranopteris linearis. Plant age (tissue age) was associated with the (228)Th/(228)Ra ratio in fronds, which implies the accumulation time of immobile elements in the plant tissue or the life span of the fronds. Results indicated that the accumulation of alkaline earth elements in D. linearis is relatively constant with increased age, while the K concentration is reversed with age because of translocation among plant tissues. Estimation of dating uncertainty based on measurement conditions revealed that the radiometric technique can be applied to trace chronosequential changes of elemental concentrations and environmental pollutants in plants with ages of less than 10-15 years.

Physics of tissue harmonic imaging by ultrasound

NASA Astrophysics Data System (ADS)

Jing, Yuan

Tissue Harmonic Imaging (THI) is an imaging modality that is currently deployed on diagnostic ultrasound scanners. In THI the amplitude of the ultrasonic pulse that is used to probe the tissue is large enough that the pulse undergoes nonlinear distortion as it propagates into the tissue. One result of the distortion is that as the pulse propagates energy is shifted from the fundamental frequency of the source pulse into its higher harmonics. These harmonics will scatter off objects in the tissue and images formed from the scattered higher harmonics are considered to have superior quality to the images formed from the fundamental frequency. Processes that have been suggested as possibly responsible for the improved imaging in THI include: (1) reduced sensitivity to reverberation, (2) reduced sensitivity to aberration, and (3) reduction in side lobes. By using a combination of controlled experiments and numerical simulations, these three reasons have been investigated. A single element transducer and a clinical ultrasound scanner with a phased array transducer were used to image a commercial tissue-mimicking phantom with calibrated targets. The higher image quality achieved with THI was quantified in terms of spatial resolution and "clutter" signals. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed. A time-domain code for solving the KZK equation was validated with measurements of the acoustic field generated by the single element transducer and the phased array transducer. The code was used to investigate the impact of aberration using tissue-like media with three-dimensional variations in all acoustic properties. The three-dimensional maps of tissue properties were derived from the datasets available through the Visible Female project. The experiments and simulations demonstrated that second harmonic imaging (1) suffers less clutter associated with reverberation; (2) is not immune to aberration effects and (3) suffers less clutter due to reduced side-lobe levels. The results indicate that side lobe suppression is the most significant reason for the improvement of second harmonic imaging.

Mueller matrix approach for probing multifractality in the underlying anisotropic connective tissue

NASA Astrophysics Data System (ADS)

Das, Nandan Kumar; Dey, Rajib; Ghosh, Nirmalya

2016-09-01

Spatial variation of refractive index (RI) in connective tissues exhibits multifractality, which encodes useful morphological and ultrastructural information about the disease. We present a spectral Mueller matrix (MM)-based approach in combination with multifractal detrended fluctuation analysis (MFDFA) to exclusively pick out the signature of the underlying connective tissue multifractality through the superficial epithelium layer. The method is based on inverse analysis on selected spectral scattering MM elements encoding the birefringence information on the anisotropic connective tissue. The light scattering spectra corresponding to the birefringence carrying MM elements are then subjected to the Born approximation-based Fourier domain preprocessing to extract ultrastructural RI fluctuations of anisotropic tissue. The extracted RI fluctuations are subsequently analyzed via MFDFA to yield the multifractal tissue parameters. The approach was experimentally validated on a simple tissue model comprising of TiO2 as scatterers of the superficial isotropic layer and rat tail collagen as an underlying anisotropic layer. Finally, the method enabled probing of precancer-related subtle alterations in underlying connective tissue ultrastructural multifractality from intact tissues.

Characterization of Mechanical Properties of Tissue Scaffolds by Phase Contrast Imaging and Finite Element Modeling.

PubMed

Bawolin, Nahshon K; Dolovich, Allan T; Chen, Daniel X B; Zhang, Chris W J

2015-08-01

In tissue engineering, the cell and scaffold approach has shown promise as a treatment to regenerate diseased and/or damaged tissue. In this treatment, an artificial construct (scaffold) is seeded with cells, which organize and proliferate into new tissue. The scaffold itself biodegrades with time, leaving behind only newly formed tissue. The degradation qualities of the scaffold are critical during the treatment period, since the change in the mechanical properties of the scaffold with time can influence cell behavior. To observe in time the scaffold's mechanical properties, a straightforward method is to deform the scaffold and then characterize scaffold deflection accordingly. However, experimentally observing the scaffold deflection is challenging. This paper presents a novel study on characterization of mechanical properties of scaffolds by phase contrast imaging and finite element modeling, which specifically includes scaffold fabrication, scaffold imaging, image analysis, and finite elements (FEs) modeling of the scaffold mechanical properties. The innovation of the work rests on the use of in-line phase contrast X-ray imaging at 20 KeV to characterize tissue scaffold deformation caused by ultrasound radiation forces and the use of the Fourier transform to identify movement. Once deformation has been determined experimentally, it is then compared with the predictions given by the forward solution of a finite element model. A consideration of the number of separate loading conditions necessary to uniquely identify the material properties of transversely isotropic and fully orthotropic scaffolds is also presented, along with the use of an FE as a form of regularization.

LC3-mediated fibronectin mRNA translation induces fibrosarcoma growth by increasing connective tissue growth factor

PubMed Central

Ying, Lihua; Lau, Agatha; Alvira, Cristina M.; West, Robert; Cann, Gordon M.; Zhou, Bin; Kinnear, Caroline; Jan, Eric; Sarnow, Peter; Van de Rijn, Matt; Rabinovitch, Marlene

2009-01-01

Summary Previously, we related fibronectin (Fn1) mRNA translation to an interaction between an AU-rich element in the Fn1 3′ UTR and light chain 3 (LC3) of microtubule-associated proteins 1A and 1B. Since human fibrosarcoma (HT1080) cells produce little fibronectin and LC3, we used these cells to investigate how LC3-mediated Fn1 mRNA translation might alter tumor growth. Transfection of HT1080 cells with LC3 enhanced fibronectin mRNA translation. Using polysome analysis and RNA-binding assays, we show that elevated levels of translation depend on an interaction between a triple arginine motif in LC3 and the AU-rich element in Fn1 mRNA. Wild-type but not mutant LC3 accelerated HT1080 cell growth in culture and when implanted in SCID mice. Comparison of WT LC3 with vector-transfected HT1080 cells revealed increased fibronectin-dependent proliferation, adhesion and invasion. Microarray analysis of genes differentially expressed in WT and vector-transfected control cells indicated enhanced expression of connective tissue growth factor (CTGF). Using siRNA, we show that enhanced expression of CTGF is fibronectin dependent and that LC3-mediated adhesion, invasion and proliferation are CTGF dependent. Expression profiling of soft tissue tumors revealed increased expression of both LC3 and CTGF in some locally invasive tumor types. PMID:19366727

Ultrasound interstitial thermal therapy (USITT) for the treatment of uterine myomas

NASA Astrophysics Data System (ADS)

Nau, William H., Jr.; Diederich, Chris J.; Simko, Jeff; Juang, Titania; Jacoby, Alison; Burdette, E. C.

2007-02-01

Uterine myomas (fibroids) are the most common pelvic tumors occurring in women, and are the leading cause of hysterectomy. Symptoms can be severe, and traditional treatments involve either surgical removal of the uterus (hysterectomy), or the fibroids (myomectomy). Interstitial ultrasound technologies have demonstrated potential for hyperthermia and high temperature thermal therapy in the treatment of benign and malignant tumors. These ultrasound devices offer favorable energy penetration allowing large volumes of tissue to be treated in short periods of time, as well as axial and angular control of heating to conform thermal treatment to a targeted tissue, while protecting surrounding tissues from thermal damage. The goal of this project is to evaluate interstitial ultrasound for controlled thermal coagulation of fibroids. Multi-element applicators were fabricated using tubular transducers, some of which were sectored to produce 180° directional heating patterns, and integrated with water cooling. Human uterine fibroids were obtained after routine myomectomies, and instrumented with thermocouples spaced at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm from the applicator. Power levels ranging from 8-15 W per element were applied for up to 15 minute heating periods. Results demonstrated that therapeutic temperatures >50° C and cytotoxic thermal doses (t 43) extended beyond 2 cm radially from the applicator (>4 cm diameter). It is anticipated that this system will make a significant contribution toward the treatment of uterine fibroids.

Adverse health effects in Canada geese (Branta canadensis) associated with waste from zinc and lead mines in the Tri-State Mining District (Kansas, Oklahoma, and Missouri, USA).

PubMed

van der Merwe, Deon; Carpenter, James W; Nietfeld, Jerome C; Miesner, John F

2011-07-01

Lead and zinc poisoning have been recorded in a variety of bird species, including migrating waterfowl such as Canada Geese (Branta canadensis), at sites contaminated with mine waste from lead and zinc mines in the Tri-State Mining District, Kansas, Oklahoma, and Missouri, USA. The adverse health impacts from mine waste on these birds may, however, be more extensive than is apparent from incidental reports of clinical disease. To characterize health impacts from mine waste on Canada Geese that do not have observable signs of poisoning, four to eight apparently healthy birds per site were collected from four contaminated sites and an uncontaminated reference site, and examined for physical and physiologic evidence of metals poisoning. Tissue concentrations of silver, aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, selenium, thallium, vanadium, and zinc were determined by inductively coupled plasma mass spectroscopy. Adverse health effects due to lead were characterized by assessing blood δ-aminolevulinic acid dehydratase (ALAD) enzyme activity. Adverse effects associated with zinc poisoning were determined from histologic examination of pancreas tissues. Elevated tissue lead concentrations and inhibited blood ALAD enzyme activities were consistently found in birds at all contaminated sites. Histopathologic signs of zinc poisoning, including fibrosis and vacuolization, were associated with elevated pancreatic zinc concentrations at one of the study sites. Adverse health effects associated with other analyzed elements, or tissue concentrations indicating potentially toxic exposure levels to these elements, were not observed.

Computational studies of transthoracic and transvenous defibrillation in a detailed 3-D human thorax model.

PubMed

Jorgenson, D B; Haynor, D R; Bardy, G H; Kim, Y

1995-02-01

A method for constructing and solving detailed patient-specific 3-D finite element models of the human thorax is presented for use in defibrillation studies. The method utilizes the patient's own X-ray CT scan and a simplified meshing scheme to quickly and efficiently generate a model typically composed of approximately 400,000 elements. A parameter sensitivity study on one human thorax model to examine the effects of variation in assigned tissue resistivity values, level of anatomical detail included in the model, and number of CT slices used to produce the model is presented. Of the seven tissue types examined, the average left ventricular (LV) myocardial voltage gradient was most sensitive to the values of myocardial and blood resistivity. Incorrectly simplifying the model, for example modeling the heart as a homogeneous structure by ignoring the blood in the chambers, caused the average LV myocardial voltage gradient to increase by 12%. The sensitivity of the model to variations in electrode size and position was also examined. Small changes (< 2.0 cm) in electrode position caused average LV myocardial voltage gradient values to increase by up to 12%. We conclude that patient-specific 3-D finite element modeling of human thoracic electric fields is feasible and may reduce the empiric approach to insertion of implantable defibrillators and improve transthoracic defibrillation techniques.

Novel promoters and coding first exons in DLG2 linked to developmental disorders and intellectual disability.

PubMed

Reggiani, Claudio; Coppens, Sandra; Sekhara, Tayeb; Dimov, Ivan; Pichon, Bruno; Lufin, Nicolas; Addor, Marie-Claude; Belligni, Elga Fabia; Digilio, Maria Cristina; Faletra, Flavio; Ferrero, Giovanni Battista; Gerard, Marion; Isidor, Bertrand; Joss, Shelagh; Niel-Bütschi, Florence; Perrone, Maria Dolores; Petit, Florence; Renieri, Alessandra; Romana, Serge; Topa, Alexandra; Vermeesch, Joris Robert; Lenaerts, Tom; Casimir, Georges; Abramowicz, Marc; Bontempi, Gianluca; Vilain, Catheline; Deconinck, Nicolas; Smits, Guillaume

2017-07-19

Tissue-specific integrative omics has the potential to reveal new genic elements important for developmental disorders. Two pediatric patients with global developmental delay and intellectual disability phenotype underwent array-CGH genetic testing, both showing a partial deletion of the DLG2 gene. From independent human and murine omics datasets, we combined copy number variations, histone modifications, developmental tissue-specific regulation, and protein data to explore the molecular mechanism at play. Integrating genomics, transcriptomics, and epigenomics data, we describe two novel DLG2 promoters and coding first exons expressed in human fetal brain. Their murine conservation and protein-level evidence allowed us to produce new DLG2 gene models for human and mouse. These new genic elements are deleted in 90% of 29 patients (public and in-house) showing partial deletion of the DLG2 gene. The patients' clinical characteristics expand the neurodevelopmental phenotypic spectrum linked to DLG2 gene disruption to cognitive and behavioral categories. While protein-coding genes are regarded as well known, our work shows that integration of multiple omics datasets can unveil novel coding elements. From a clinical perspective, our work demonstrates that two new DLG2 promoters and exons are crucial for the neurodevelopmental phenotypes associated with this gene. In addition, our work brings evidence for the lack of cross-annotation in human versus mouse reference genomes and nucleotide versus protein databases.

Subcellular Mn compartation, anatomic and biochemical changes of two grape varieties in response to excess manganese.

PubMed

Yao, Yinan; Xu, Gang; Mou, Dongling; Wang, Junru; Ma, Jinbiao

2012-09-01

To explore the underlying mechanism for the high tolerance to excess manganese stress in the grape species (Vitis vinifera Linn), we observed the subcellular compartment of Mn element, anatomic and biochemical responses of two grape cultivars (Combier and Shuijin) under excess Mn stress in semi-controlled environmental condition. Grape species exhibited typical detoxifying or tolerant mechanism as following: first, majority of Mn element accumulated in leaf was excluded into cell wall or comparted into cell vacuole to avoid cellular Mn-toxicity; Mn and other elements were also secreted into leaf surface or deposited in vascular wall; second, only small amount of Mn was located in cellular organ, and excess Mn in chloroplast was detoxified by depositing in starch granule, which serve as a novel detoxifying strategy; additionally, the cellular Mn was further chelated by phytochelatins; third, to quench the toxic oxygen radicals, the total phenolic compounds and polyamine (putrescine and spermidine) were enhanced. Although the obvious symptom of Mn-toxicity was not detected, we observed the dessication symptom under high level of Mn treatment in the two cultivars, such as sunk stomata, thickened palisade tissue, enhanced palisade/spongy tissue ratio and abscisic acid concentration. The growth inhibition and dessication symptom in the two grape cultivars could be largely associated with osmotic stress resulted from high concentration of leaf Mn. Copyright © 2012 Elsevier Ltd. All rights reserved.

High-resolution elemental mapping of human placental chorionic villi using synchrotron X-ray fluorescence spectroscopy

DOE PAGES

Punshon, Tracy; Chen, Si; Finney, Lydia; ...

2015-07-03

The placenta is the organ that mediates transport of nutrients and waste materials between mother and fetus. Synchrotron X-ray fluorescence (SXRF) microanalysis is a tool for imaging the distribution and quantity of elements in biological tissue, which can be used to study metal transport across biological membranes. Our aims were to pilot placental biopsy specimen preparation techniques that could be integrated into an ongoing epidemiology birth cohort study without harming rates of sample acquisition. We studied the effects of fixative (formalin or glutaraldehyde) and storage duration (30 days or immediate processing) on metal distribution and abundance and investigated a thaw-fixationmore » protocol for archived specimens stored at -80° C. We measured fixative elemental composition with and without a placental biopsy via inductively coupled plasma mass spectrometry (ICP-MS) to quantify fixative-induced elemental changes. Formalin-fixed specimens showed hemolysis of erythrocytes. The glutaraldehyde-paraformaldehyde solution in HEPES buffer (GTA-HEPES) had superior anatomical preservation, avoided hemolysis, and minimized elemental loss, although some cross-linking of exogenous Zn was evident. Elemental loss from tissue stored in fixative for 1 month showed variable losses (≈ 40 % with GTA-HEPES), suggesting storage duration be controlled for. Lastly, thawing of tissue held at -80 °C in a GTA-HEPES solution provided high-quality visual images and elemental images« less

Analysis of the influences of short-term levosimendan exposure on oxidant/antioxidant status and trace-element levels in the physiological status of the thoracic aorta of rats.

PubMed

Aydin, Cemalettin; Ay, Yasin; Basel, Halil; Kavak, Servet; Inan, Bekir; Bektaş, Hava; Gümrükçüoğlu, Hasan Ali; Ekim, Hasan; Demir, Halit

2012-12-01

The objective of this study was to evaluate the effect of levosimendan (chemical formula C₁₄H₁₂N₆O) exposure on oxidant/antioxidant status and trace-element levels in the thoracic aorta of rats. Eighteen male Wistar albino rats were randomly divided into two groups of eight animals each. Group 1 was not exposed to levosimendan and served as a control. Levosimendan (12 μg/kg) diluted in 10 ml 0.5 % dextrose was administered intraperitoneally to group 2. Animals of both groups were killed after 3 days, and their thoracic aortae were harvested for determination of changes in tissue oxidant/antioxidant status and trace-element levels. The animals in both groups were killed 72 h after levosimendan exposure, and thoracic aortae were harvested for determination of the lipid peroxidation product MDA and antioxidant GSH levels and the activities of antioxidant enzymes such as SOD, GSH-Px and CAT. It was found that MDA, GSH and CAT enzyme levels increased in thoracic aortae of rats after levosimendan administration. SOD and CA enzyme activities and the level of antioxidant GSH decreased in thoracic aortae of rats after levosimendan treatment. Pb, Cd and Fe levels of thoracic aortae were significantly higher (P < 0.001) and Mg, Mn, Zn and Cu were significantly lower (P < 0.001) in the levosimendan group compared to the control group. These results suggest that short-term levosimendan treatment caused an increase in free radical production and a decrease in antioxidant enzyme activity in thoracic aortae of levosimendan-treated rats. It also causes a decrease or increase in many mineral levels of the thoracic aorta, which is an undesirable condition for normal pharmacological function.

In vivo microvascular imaging of human oral and nasal cavities using swept-source optical coherence tomography with a single forward/side viewing probe

NASA Astrophysics Data System (ADS)

Choi, Woo June; Wang, Ruikang K.

2015-03-01

We report three-dimensional (3D) imaging of microcirculation within human cavity tissues in vivo using a high-speed swept-source optical coherence tomography (SS-OCT) at 1.3 μm with a modified probe interface. Volumetric structural OCT images of the inner tissues of oral and nasal cavities are acquired with a field of view of 2 mm x 2 mm. Two types of disposable and detachable probe attachments are devised and applied to the port of the imaging probe of OCT system, enabling forward and side imaging scans for selective and easy access to specific cavity tissue sites. Blood perfusion is mapped with OCT-based microangiography from 3D structural OCT images, in which a novel vessel extraction algorithm is used to decouple dynamic light scattering signals, due to moving blood cells, from the background scattering signals due to static tissue elements. Characteristic tissue anatomy and microvessel architectures of various cavity tissue regions of a healthy human volunteer are identified with the 3D OCT images and the corresponding 3D vascular perfusion maps at a level approaching capillary resolution. The initial finding suggests that the proposed method may be engineered into a promising tool for evaluating and monitoring tissue microcirculation and its alteration within a wide-range of cavity tissues in the patients with various pathological conditions.

Factors that Affect the Content of Cadmium, Nickel, Copper and Zinc in Tissues of the Knee Joint.

PubMed

Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Jakóbik-Kolon, Agata; Kluczka, Joanna; Babuśka-Roczniak, Magdalena

2017-08-01

Osteoarthritis causes the degradation of the articular cartilage and periarticular bones. Trace elements influence the growth, development and condition of the bone tissue. Changes to the mineral composition of the bone tissue can cause degenerative changes and fractures. The aim of the research was to determine the content of cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) in the tibia, the femur and the meniscus in men and women who underwent a knee replacement surgery. Samples were collected from 50 patients, including 36 women and 14 men. The determination of trace elements content were performed by ICP-AES method, using Varian 710-ES. Average concentration in the tissues of the knee joint teeth amounted for cadmium 0.015, nickel 0.60, copper 0.89 and zinc 80.81 mg/kg wet weight. There were statistically significant differences in the content of cadmium, copper and zinc in different parts of the knee joint. There were no statistically significant differences in the content of cadmium, nickel, copper and zinc in women and men in the examined parts of the knee joint. Among the elements tested, copper and nickel showed a high content in the connective tissue (the meniscus) compared to the bone tissue (the tibia and the femur).

Effects of elemental composition on the incorporation of dietary nitrogen and carbon isotopic signatures in an omnivorous songbird

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pearson, Scott, F.; Levey, Douglas, J.; Greenberg, Catheryn, H.

2003-02-28

Pearson, S.F., D.J. Levey, C.H. Greenberg, and C.M. del Rio. 2003. Effects of elemental composition on the incorporation of dietary nitrogen and carbon isotopic signatures in an omnivorous songbird. Oecologia. 135:516-523. The use of stable isotopes to infer diet requires quantifying the relationship between diet and tissues and, in particular, knowing of how quickly isotopes turnover in different tissues and how isotopic concentrations of different food components change (discriminate) when incorporated into consumer tissues. We used feeding trials with wild-caught yellow-rumped warblers (Dendroica coronata) to determine d15N and d13C turnover rates for blood, d15N and d13C diet-tissue discrimination factors, andmore » diet-tissue relationships for blood and feathers. After 3 weeks on a common diet, 36 warblers were assigned to one of four diets differing in the relative proportion of fruit and insects. Plasma half-life estimates ranged from 0.4 to 0.7 days for d13C and from 0.5 to 1.7 days for d15N. Half-life did not differ among diets. Whole blood half-life for d13C ranged from 3.9 to 6.1 days. Yellow-rumped warbler tissues were enriched relative to diet by 1.7.3.6% for nitrogen isotopes and by 1.2 to 4.3% for carbon isotopes, depending on tissue and diet. Consistent with previous studies, feathers were the most enriched and whole blood and plasma were the least enriched or, in the case of carbon, slightly depleted relative to diet. In general, tissues were more enriched relative to diet for birds with high percentages of insects. For all tissues, carbon and nitrogen isotope discrimination factors increased with carbon and nitrogen concentrations of diets. The isotopic signature of plasma increased linearly with the sum of the isotopic signature of the diet and the discrimination factor. Because the isotopic signature of tissues depends on both elemental concentration and isotopic signature of the diet, attempts to reconstruct diet from stable isotope signatures require mixing models that incorporate elemental concentration.« less

Steroidogenic enzymes of adipose tissue in modulation of trivalent chromium in a mouse model of PCOS.

PubMed

Chen, Tsung-Sheng; Chen, Yi-Ting; Liu, Chia-Hsin; Sun, Chi-Ching; Mao, Frank Chiahung

2017-01-01

Polycystic ovary syndrome (PCOS) is a type of endocrine metabolic disorder with many different consequences to health, most commonly infertility, obesity and insulin resistance. Trivalent chromium (Cr 3+ ) was previously found to improve the metabolic profiles of patients with PCOS. The aim of this study was to explore the effect of Cr on regulating steroidogenic enzymes in adipose tissue. Female BALB/c mice were divided into three groups (n = 6 per group): the control group, PCOS + placebo milk group and PCOS + Cr-containing milk group. The dietary intake of Cr significantly decreased fasting blood sugar (FBS) and homeostasis model assessment of insulin resistance levels in the murine model of PCOS. Importantly, we found significant correlations among the levels of Cr, insulin and dehydroepiandrosterone (DHEA). In adipose tissue, decreases in the enzyme expressions of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase, but not of aromatase, were observed. By understanding the role of steroidogenic enzymes in PCOS in normal and pathological states, trace elements may be used as a form of adjunctive therapy in the management of patients with PCOS.

Ganoderic Acid A improves high fat diet-induced obesity, lipid accumulation and insulin sensitivity through regulating SREBP pathway.

PubMed

Zhu, Jing; Jin, Jie; Ding, Jiexia; Li, Siying; Cen, Panpan; Wang, Keyi; Wang, Hai; Xia, Junbo

2018-06-25

Obesity and its major co-morbidity, type 2 diabetes, have been an alarming epidemic prevalence without an effective treatment available. Sterol regulatory element-binding proteins (SREBPs) are major transcription factors regulating the expression of genes involved in biosynthesis of cholesterol, fatty acid and triglyceride. Therefore, inhibition of SREBP pathway may be a useful strategy to treat obesity with type 2 diabetes. Here, we identify a small molecule, Ganoderic Acid A (GAA), inhibits the SREBP expression and decreases the cellular levels of cholesterol and fatty acid in vitro. GAA also ameliorates body weight gain and fat accumulation in liver or adipose tissues, and improves serum lipid levels and insulin sensitivity in high fat diet (HFD)-induced obese mice. Consistently, GAA regulates SREBPs target genes and metabolism associated genes in liver or adipose tissues, which may directly contribute to the lower lipid level and improvement of insulin resistance. Taken together, GAA could be a potential leading compound for development of drugs for the prevention of obesity and insulin resistance. Copyright © 2018. Published by Elsevier B.V.

Ultrastructural studies of vasopressin neurons of the paraventricular nucleus of the hypothalamus using a monoclonal antibody to vasopressin: analysis of synaptic input.

PubMed

Silverman, A J; Hou-Yu, A; Zimmerman, E A

1983-05-01

The ultrastructure of the vasopressin neurons of the paraventricular nucleus of the hypothalamus was studied by immunocytochemical techniques. Tissue antigen was detected in unembedded tissue sections using a monoclonal antibody that recognizes vasopressin but not oxytocin or vasotocin. At the light-microscopic level, reaction product was seen to fill the cytoplasm of the neuron cell body as well as large portions of the dendrite and axon. Immunoreactive spines were seen on both somatic and dendritic surfaces and their presence was confirmed at the ultrastructural level. In the light-microscope, axonal processes do not have spines and are thinner and more varicose than dendritic processes. At the electron-microscopic level, both axons and dendrites of the vasopressin cells are filled with reactive neurosecretory granules. The presence of large numbers of these organelles made it difficult to distinguish proximal dendrites from Herring bodies (axonal swellings). At the ultrastructural level, reaction product was also observed in the cytoplasm of all segments of the vasopressin cells. The presence of reaction product outside of membranous compartments is undoubtably due to disruption of membranes by detergent treatment or exposure to basic pH. However, the staining procedure used did allow us to examine the synaptic input to the vasopressin cells. All portions of the vasopressin neuron receive a diverse innervation. The somata have synapses on their surfaces and on spines. These axo-somatic terminals are primarily, but not exclusively, symmetrical and the presynaptic elements contain spherical or elongate vesicles. On the dendrites, terminals again were observed on the surface or on spines. these axo-dendritic synapses were usually asymmetrical. The presynaptic elements contained clear spherical, elongate or pleomorphic vesicles. Occasional varicosities with dense-core granules were seen to make en passant contacts with dendrites; these contacts did not have obvious membrane specializations. Input to vasopressin axons was studied both along the paraventricular-neurohypophysial tract and in the median eminence. Vasopressin axons receive a synaptic input (axo-axonic), predominately of the asymmetric variety with clear, spherical vesicles in the presynaptic element. These findings demonstrate that the vasopressin neurons of the paraventricular nucleus receive a diverse innervation.

Simulated Nitrogen Deposition has Minor Effects on Ecosystem Pools and Fluxes of Energy, Elements, and Biochemicals in a Northern Hardwoods Forest

NASA Astrophysics Data System (ADS)

Talhelm, A. F.; Pregitzer, K. S.; Burton, A. J.; Xia, M.; Zak, D. R.

2017-12-01

The elemental and biochemical composition of plant tissues is an important influence on primary productivity, decomposition, and other aspects of biogeochemistry. Human activity has greatly altered biogeochemical cycles in ecosystems downwind of industrialized regions through atmospheric nitrogen deposition, but most research on these effects focuses on individual elements or steps in biogeochemical cycles. Here, we quantified pools and fluxes of biomass, the four major organic elements (carbon, oxygen, hydrogen, nitrogen), four biochemical fractions (lignin, structural carbohydrates, cell walls, and soluble material), and energy in a mature northern hardwoods forest in Michigan. We sampled the organic and mineral soil, fine and coarse roots, leaf litter, green leaves, and wood for chemical analyses. We then combined these data with previously published and archival information on pools and fluxes within this forest, which included replicated plots receiving either ambient deposition or simulated nitrogen deposition (3 g N m-2 yr-1 for 18 years). Live wood was the largest pool of energy and all elements and biochemical fractions. However, the production of wood, leaf litter, and fine roots represented similar fluxes of carbon, hydrogen, oxygen, cell wall material, and energy, while nitrogen fluxes were dominated by leaf litter and fine roots. Notably, the flux of lignin via fine roots was 70% higher than any other flux. Experimental nitrogen deposition had relatively few significant effects, increasing foliar nitrogen, increasing the concentration of lignin in the soil organic horizon and decreasing pools of all elements and biochemical fractions in the soil organic horizon except nitrogen, lignin, and structural carbohydrates. Overall, we found that differences in tissue chemistry concentrations were important determinants of ecosystem-level pools and fluxes, but that nitrogen deposition had little effect on concentrations, pools, or fluxes in this mature forest. Disclaimer: The views expressed in this poster are those of the authors and do not necessarily represent the views or policies of the U.S. EPA.

Stress distributions in internal resorption cavities restored with different materials at different root levels: A finite element analysis study.

PubMed

Aslan, Tuğrul; Üstün, Yakup; Esim, Emir

2018-04-15

The aim of this study was to evaluate the stresses within simulated roots with internal resorption cavities at the apical, middle and coronal root levels, after obturation with gutta-percha and/or MTA utilising finite element analysis (FEA). Mandibular premolar teeth with internal resorption cavities at different root levels were modelled. Models were restored with gutta-percha and/or MTA. An oblique force of 300 N was applied and stress evaluations were carried out. In the MTA-filled resorption models, the stresses were distributed more homogeneously than the gutta-percha filled models, and the stress concentrations were lower in the remaining dentinal tissues. If the whole root is considered, the fully gutta-percha-filled models generated the highest stress values. Differences between the fully MTA-filled models and hybrid techniques were present only in the apical resorption models. Both the MTA and combination of MTA and gutta-percha can be suggested for use in clinical practice, in cases of internal root resorption cavity obturation. © 2018 Australian Society of Endodontology Inc.

The Combination of Blueberry Juice and Probiotics Ameliorate Non-Alcoholic Steatohepatitis (NASH) by Affecting SREBP-1c/PNPLA-3 Pathway via PPAR-α

PubMed Central

Ren, Tingting; Zhu, Juanjuan; Zhu, Lili; Cheng, Mingliang

2017-01-01

Nonalcoholic steatohepatitis (NASH) is liver inflammation and a major threat to public health. Several pharmaceutical agents have been used for NASH therapy but their high-rate side effects limit the use. Blueberry juice and probiotics (BP) have anti-inflammation and antibacterial properties, and may be potential candidates for NASH therapy. To understand the molecular mechanism, Sprague Dawley rats were used to create NASH models and received different treatments. Liver tissues were examined using HE (hematoxylin and eosin) and ORO (Oil Red O) stain, and serum biochemical indices were measured. The levels of peroxisome proliferators-activated receptor (PPAR)-α, sterol regulatory element binding protein-1c (SREBP-1c), Patatin-like phospholipase domain-containing protein 3 (PNPLA-3), inflammatory cytokines and apoptosis biomarkers in liver tissues were measured by qRT-PCR and Western blot. HE and ORO analysis indicated that the hepatocytes were seriously damaged with more and larger lipid droplets in NASH models while BP reduced the number and size of lipid droplets (p < 0.05). Meanwhile, BP increased the levels of SOD (superoxide dismutase), GSH (reduced glutathione) and HDL-C (high-density lipoprotein cholesterol), and reduced the levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase), TG (triglycerides), LDL-C (low-density lipoprotein cholesterol) and MDA (malondialdehyde) in NASH models (p < 0.05). BP increased the level of PPAR-α (Peroxisome proliferator-activated receptor α), and reduced the levels of SREBP-1c (sterol regulatory element binding protein-1c) and PNPLA-3 (Patatin-like phospholipase domain-containing protein 3) (p < 0.05). BP reduced hepatic inflammation and apoptosis by affecting IL-6 (interleukin 6), TNF-α (Tumor necrosis factor α), caspase-3 and Bcl-2 in NASH models. Furthermore, PPAR-α inhibitor increased the level of SREBP-1c and PNPLA-3. Therefore, BP prevents NASH progression by affecting SREBP-1c/PNPLA-3 pathway via PPAR-α. PMID:28264426

The Combination of Blueberry Juice and Probiotics Ameliorate Non-Alcoholic Steatohepatitis (NASH) by Affecting SREBP-1c/PNPLA-3 Pathway via PPAR-α.

PubMed

Ren, Tingting; Zhu, Juanjuan; Zhu, Lili; Cheng, Mingliang

2017-02-27

Nonalcoholic steatohepatitis (NASH) is liver inflammation and a major threat to public health. Several pharmaceutical agents have been used for NASH therapy but their high-rate side effects limit the use. Blueberry juice and probiotics (BP) have anti-inflammation and antibacterial properties, and may be potential candidates for NASH therapy. To understand the molecular mechanism, Sprague Dawley rats were used to create NASH models and received different treatments. Liver tissues were examined using HE (hematoxylin and eosin) and ORO (Oil Red O) stain, and serum biochemical indices were measured. The levels of peroxisome proliferators-activated receptor (PPAR)-α, sterol regulatory element binding protein-1c (SREBP-1c), Patatin-like phospholipase domain-containing protein 3 (PNPLA-3), inflammatory cytokines and apoptosis biomarkers in liver tissues were measured by qRT-PCR and Western blot. HE and ORO analysis indicated that the hepatocytes were seriously damaged with more and larger lipid droplets in NASH models while BP reduced the number and size of lipid droplets ( p < 0.05). Meanwhile, BP increased the levels of SOD (superoxide dismutase), GSH (reduced glutathione) and HDL-C (high-density lipoprotein cholesterol), and reduced the levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase), TG (triglycerides), LDL-C (low-density lipoprotein cholesterol) and MDA (malondialdehyde) in NASH models ( p < 0.05). BP increased the level of PPAR-α (Peroxisome proliferator-activated receptor α), and reduced the levels of SREBP-1c (sterol regulatory element binding protein-1c) and PNPLA-3 (Patatin-like phospholipase domain-containing protein 3) ( p < 0.05). BP reduced hepatic inflammation and apoptosis by affecting IL-6 (interleukin 6), TNF-α (Tumor necrosis factor α), caspase-3 and Bcl-2 in NASH models. Furthermore, PPAR-α inhibitor increased the level of SREBP-1c and PNPLA-3. Therefore, BP prevents NASH progression by affecting SREBP-1c/PNPLA-3 pathway via PPAR-α.

Iron biomineralization of brain tissue and neurodegenerative disorders

NASA Astrophysics Data System (ADS)

Mikhaylova (Mikhailova), Albina

The brain is an organ with a high concentration of iron in specific areas, particularly in the globus pallidus, the substantia nigra, and the red nucleus. In certain pathological states, such as iron overload disease and neurodegenerative disorders, a disturbed iron metabolism can lead to increased accumulation of iron not only in these areas, but also in the brain regions that are typically low in iron content. Recent studies of the physical and magnetic properties of metalloproteins, and in particular the discovery of biogenic magnetite in human brain tissue, have raised new questions about the role of biogenic iron formations in living organisms. Further investigations revealed the presence of magnetite-like crystalline structures in human ferritin, and indicated that released ferritin iron might act as promoter of oxidative damage to tissue, therefore contributing to pathogenesis of neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases. The purpose of this work was to examine the elemental composition and structure of iron deposits in normal brain tissue as well as tissue affected by neurodegenerative disorders. Employing the methods of X-ray microfocus fluorescence mapping, X-ray Absorption Near Edge Structure (XANES), X-ray Absorption Fine Structure spectroscopy (XAFS), and light and electron microscopic examinations allows one to obtain qualitative as well as quantitative data with respect to the cellular distribution and chemical state of iron at levels not detected previously. The described tissue preparation technique allows not only satisfactory XAS iron elemental imaging in situ but also multimodal examination with light and electron microscopes of the same samples. The developed protocol has assured consistent and reproducible results on relatively large sections of flat-embedded tissue. The resulting tissue samples were adequate for XAS examination as well as sufficiently well-preserved for future microscopy studies. The continued development of this technique should lead to major advances in mapping iron anomalies and the related chemical and structural information directly to cells and tissue structures in human brain tissue. At present this is done primarily by iron staining methods and any information on the relationship between iron distribution and cellular structures obtained this way is limited. Iron staining also offers no information on the specific compounds of iron that are present. This can be vitally important as the form of iron [including its oxidation state] in the human body can determine whether it plays a detrimental or beneficial role in neurophysiological processes.

Summary of information on synthetic organic compounds and trace elements in tissue of aquatic biota, Clark Fork-Pend Oreille and Spokane River basins, Montana, Idaho, and Washington, 1974-96

USGS Publications Warehouse

Maret, Terry R.; Dutton, DeAnn M.

1999-01-01

As part of the Northern Rockies Intermontane Basins study of the National Water-Quality Assessment Program, data collected between 1974 and 1996 were compiled to describe contaminants in tissue of riverine species. Tissue-contaminant data from 11 monitoring programs and studies representing 28 sites in the study area were summarized. Tissue-contaminant data for most streams generally were lacking. Many studies have focused on and around mining-affected areas on the Clark Fork and Coeur d'Alene Rivers and their major tributaries. DDT and PCBs and their metabolites and congeners were the synthetic organic contaminants most commonly detected in fish tissue. Fish collected from the Spokane River in Washington contained elevated concentrations of PCB arochlors, some of which exceeded guidelines for the protection of human health and predatory wildlife. Tissue samples of fish from the Flathead River watershed contained higher-than-expected concentrations of PCBs, which might have resulted from atmospheric transport. Trace element concentrations in fish and macroinvertebrates collected in and around mining areas were elevated compared with background concentrations. Some cadmium, copper, lead, and mercury concentrations in fish tissue were elevated compared with results from other studies, and some exceeded guidelines. Macroinvertebrates from the Coeur d'Alene River contained higher concentrations of cadmium, lead, and zinc than did macroinvertebrates from other river systems in mining-affected areas. A few sportfish fillet samples, most from the Spokane River in Washington, were collected to assess human health risk. Concentrations of PCBs in these fillets exceeded screening values for the protection of human health. At present, there is no coordinated, long-term fish tissue monitoring program for rivers in the study area, even though contaminants are present in fish at levels considered a threat to human health. Development of a coordinated, centralized national data base for contaminants in fish tissue is needed. The National Water-Quality Assessment Program can provide a framework for other agencies to evaluate tissue contaminants in the Northern Rockies Intermontane Basins study area. As of 1996, there are no fish consumption advisories or fishing restrictions as a result of elevated contaminants on any rivers within the study area.

Face-based smoothed finite element method for real-time simulation of soft tissue

NASA Astrophysics Data System (ADS)

Mendizabal, Andrea; Bessard Duparc, Rémi; Bui, Huu Phuoc; Paulus, Christoph J.; Peterlik, Igor; Cotin, Stéphane

2017-03-01

In soft tissue surgery, a tumor and other anatomical structures are usually located using the preoperative CT or MR images. However, due to the deformation of the concerned tissues, this information suffers from inaccuracy when employed directly during the surgery. In order to account for these deformations in the planning process, the use of a bio-mechanical model of the tissues is needed. Such models are often designed using the finite element method (FEM), which is, however, computationally expensive, in particular when a high accuracy of the simulation is required. In our work, we propose to use a smoothed finite element method (S-FEM) in the context of modeling of the soft tissue deformation. This numerical technique has been introduced recently to overcome the overly stiff behavior of the standard FEM and to improve the solution accuracy and the convergence rate in solid mechanics problems. In this paper, a face-based smoothed finite element method (FS-FEM) using 4-node tetrahedral elements is presented. We show that in some cases, the method allows for reducing the number of degrees of freedom, while preserving the accuracy of the discretization. The method is evaluated on a simulation of a cantilever beam loaded at the free end and on a simulation of a 3D cube under traction and compression forces. Further, it is applied to the simulation of the brain shift and of the kidney's deformation. The results demonstrate that the method outperforms the standard FEM in a bending scenario and that has similar accuracy as the standard FEM in the simulations of the brain-shift and of the kidney's deformation.

Finite-Element Methods for Real-Time Simulation of Surgery

NASA Technical Reports Server (NTRS)

Basdogan, Cagatay

2003-01-01

Two finite-element methods have been developed for mathematical modeling of the time-dependent behaviors of deformable objects and, more specifically, the mechanical responses of soft tissues and organs in contact with surgical tools. These methods may afford the computational efficiency needed to satisfy the requirement to obtain computational results in real time for simulating surgical procedures as described in Simulation System for Training in Laparoscopic Surgery (NPO-21192) on page 31 in this issue of NASA Tech Briefs. Simulation of the behavior of soft tissue in real time is a challenging problem because of the complexity of soft-tissue mechanics. The responses of soft tissues are characterized by nonlinearities and by spatial inhomogeneities and rate and time dependences of material properties. Finite-element methods seem promising for integrating these characteristics of tissues into computational models of organs, but they demand much central-processing-unit (CPU) time and memory, and the demand increases with the number of nodes and degrees of freedom in a given finite-element model. Hence, as finite-element models become more realistic, it becomes more difficult to compute solutions in real time. In both of the present methods, one uses approximate mathematical models trading some accuracy for computational efficiency and thereby increasing the feasibility of attaining real-time up36 NASA Tech Briefs, October 2003 date rates. The first of these methods is based on modal analysis. In this method, one reduces the number of differential equations by selecting only the most significant vibration modes of an object (typically, a suitable number of the lowest-frequency modes) for computing deformations of the object in response to applied forces.

Elemental distribution in ascending aortic after radiotherapy and chemotherapy by Low Energy X-ray Fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Mantuano, A.; Mota, C. L.; Pickler, A.; Sena, G.; Braz, D.; Salata, C.; de Almeida, C. E.; Costa, F. N.; Barroso, R. C.

2018-05-01

Breast cancer (BC) is the most frequent cancer and the leading cause of cancer-related mortality in women. The treatment techniques for the BC include chemotherapy (CT) and/or radiotherapy (RT) and can modify elementary the cell matrix by calcificating tissues due to biological and morphological changes. Also, treatments for BC induce cardiotoxicity and it is important to understand the mechanisms involved in order to prevent this late effect in treated breast cancer patients. The high incidence of cardiovascular mortality in breast cancer patients is partially credited to increased intimal and medial calcifications of the aorta. The aim of this work is to investigate the distibution of low atomic number elements such as Magnesium (Mg), due to its importance for the cardiac metabolism; iron (Fe), since BC treatment may be associated with oxidative stress; and Sodium (Na), that is extremely related to the damage of endothelial cells. An optimal technique to observe these changes in aorta tissue is soft X-ray FLuorescence that can provide elemental maps of these important elements. The results performed by Low Energy X-ray Fluorescence LEXRF analyses showed that when the tissue is submitted to treatments with CT and/or RT, some normal structures become disorganized, and consequently the intensity of elemental compounds can be changed. All the experiments were carried out at the TwinMic beamline at Elettra Synchrotron facility using as animal model Wistar rats in order to evaluate the distribution of Na, Mg and Fe in aorta walls of Wistar rats, after BC treatment. Simultaneous acquisition of LEXRF and attenuation coefficient maps suggest that the combined chemotherapy and radiotherapy caused more damage to the aortic tissue as compared to radiation therapy alone. These findings add an in-depth understanding of elemental lack or excess in the tissue and contribute to locate these changes.

Determination of Heavy Metal Concentrations in Normal and Pathological Human Endometrial Biopsies and In Vitro Regulation of Gene Expression by Metals in the Ishikawa and Hec-1b Endometrial Cell Line

PubMed Central

Tomkiewicz, Céline; Leblanc, Alix; Pierre, Stéphane; El Balkhi, Souleiman; Le Frère-Belda, Marie-Aude; Lecuru, Fabrice; Poupon, Joël; Barouki, Robert; Aggerbeck, Martine; Coumoul, Xavier

2015-01-01

It is well known that several metals, such as lead, mercury, cadmium, and vanadium, can mimic the effects of estrogens (metallo-estrogens). Nevertheless, there are only a few studies that have assessed the effects of toxic metals on the female genital tract and, in particular, endometrial tissue. In this context, we measured the concentrations of several trace elements in human endometrial tissue samples from individuals with hyperplasia or adenocarcinoma and in normal tissues. Hyperplasic endometrial tissue has a 4-fold higher concentration of mercury than normal tissue. Mercury can affect both the AhR and ROS signaling pathways. Thus, we investigated the possible toxic effects of mercury by in vitro studies. We found that mercury increases oxidative stress (increased HO1 and NQO1 mRNA levels) and alters the cytoskeleton in the human endometrial Ishikawa cell line and to a lesser extent, in the “less-differentiated” human endometrial Hec-1b cells. The results might help to explain a potential link between this metal and the occurrence of endometrial hyperplasia. PMID:26600472

Structural and mechanical design of tissue interfaces in the giant reed Arundo donax.

PubMed

Rüggeberg, Markus; Burgert, Ingo; Speck, Thomas

2010-03-06

The culms of the giant reed Arundo donax represent slender tube-like structures. Several nodes along the culm, a ring of sclerenchymatous fibres in the periphery of the culm wall and numerous isolated vascular bundles enclosed by fibre rings in the culm wall function as stiffening elements. The bundles are embedded in lignified parenchyma. Micromechanical analysis indicated differences in stiffness between the individual tissues of more than one order of magnitude. In case of abrupt transitions in stiffness at the interfaces, stress discontinuities arise under dynamic loads. This eventually leads to critical shear stresses at cell ends, and culm failure may be initiated at these points. Pronounced mechanical differences between individual tissues can be compromised by gradual transitions at their interfaces. Ultrastructural and spectroscopic investigations with high spatial resolution revealed a gradual transition of cell parameters (cell wall area fraction and cell length). However, cell wall parameters (cellulose microfibril angle and lignin content) showed abrupt transitions or remained almost constant across the interfaces between various tissues. The design principles found at the interfaces between tissues in the culm walls of A. donax are discussed as an adaptation strategy to mechanical loads at different levels of hierarchy.

Structural and mechanical design of tissue interfaces in the giant reed Arundo donax

PubMed Central

Rüggeberg, Markus; Burgert, Ingo; Speck, Thomas

2010-01-01

The culms of the giant reed Arundo donax represent slender tube-like structures. Several nodes along the culm, a ring of sclerenchymatous fibres in the periphery of the culm wall and numerous isolated vascular bundles enclosed by fibre rings in the culm wall function as stiffening elements. The bundles are embedded in lignified parenchyma. Micromechanical analysis indicated differences in stiffness between the individual tissues of more than one order of magnitude. In case of abrupt transitions in stiffness at the interfaces, stress discontinuities arise under dynamic loads. This eventually leads to critical shear stresses at cell ends, and culm failure may be initiated at these points. Pronounced mechanical differences between individual tissues can be compromised by gradual transitions at their interfaces. Ultrastructural and spectroscopic investigations with high spatial resolution revealed a gradual transition of cell parameters (cell wall area fraction and cell length). However, cell wall parameters (cellulose microfibril angle and lignin content) showed abrupt transitions or remained almost constant across the interfaces between various tissues. The design principles found at the interfaces between tissues in the culm walls of A. donax are discussed as an adaptation strategy to mechanical loads at different levels of hierarchy. PMID:19726440

[Determination of Trace Elements in Marine Cetaceans by ICP-MS and Health Risk Assessment].

PubMed

Ding, Yu-long; Ning, Xi; Gui, Duan; Mo, Hui; Li, Yu-sen; Wu, Yu-ping

2015-09-01

The liver, kidney and muscle samples from seven cetaceans were digested by microwave digestion, and trace elements amounts of V, Cd, Cu, Zn, As, Cr, Ni, Mn, Se, Hg and Pb were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the health risk assessment for Zn, Cu, Cd, Hg, Se in the liver was conducted. The results of international lobster hepatopancreas standard (TORT-2) showed acceptable agreement with the certified values, and the relative standard deviation (RSD) of eleven kinds of trace elements were less than 3.54%, showing that the method is suitable for the determination of trace elements in cetaceans. The experimental results indicated that different tissues and organs of the dolphins had different trace elements, presenting the tissue specificity. There is a certain inter-species difference among different dolphins about the bioaccumulation ability of the trace elements. The distribution of trace elements in whales presented a certain regularity: the contents of most elements in liver, kidney were much higher than the contents of muscle tissues, Cu, Mn, Hg, Se, and Zn exhibit the higher concentrations in liver, while Cd was mainly accumulated in kidney. And according to the health risk assessment in liver, the exceeding standardrate of selenium and copper in seven kinds of whales was 100%, suggesting that these whales were suffering the contamination of trace elements. The experimental results is instructive to the study of trace elements in cetaceans, while this is the first report for the concentrations in organs of Striped dolphin, Bottlenose dolphin, Fraser's Dolphin and Risso's dolphin in China, it may provide us valuable data for the conservation of cetaceans.

Decoupling the effect of shear stress and stretch on tissue growth & remodeling in a vascular graft.

PubMed

van Haaften, Eline E; Wissing, Tamar B; Rutten, Marcel; Bulsink, Jurgen A; Gashi, Kujtim; van Kelle, Mathieu A J; Smits, Anthal; Bouten, Carlijn; Kurniawan, Nicholas A

2018-06-07

The success of cardiovascular tissue engineering strategies largely depends on the mechanical environment in which cells develop a neo-tissue via growth and remodeling processes. This mechanical environment is defined by the local scaffold architecture to which cells adhere, i.e., the micro-environment, and by external mechanical cues to which cells respond, i.e., hemodynamic loading. The hemodynamic environment of early-developing blood vessels consists of both shear stress (due to blood flow) and circumferential stretch (due to blood pressure). Experimental platforms that recapitulate this mechanical environment in a controlled and tunable manner are thus critical for investigating cardiovascular tissue engineering. In traditional perfusion bioreactors, however, shear stress and stretch are coupled, hampering a clear delineation of their effects on cell and tissue response. Here, we uniquely designed a bioreactor that independently combines these two types of mechanical cues in eight parallel vascular grafts. The system is computationally and experimentally validated, through finite element analysis and culture of tissue constructs respectively, to distinguish various levels of shear stress (up to 5 Pa) and cyclic stretch (up to 1.10). To illustrate the usefulness of the system, we investigated the relative contribution of cyclic stretch (1.05 at 0.5 Hz) and shear stress (1 Pa) to tissue development. Both types of hemodynamic loading contributed to cell alignment, but the contribution of shear stress overruled stretch-induced cell proliferation and matrix (i.e., collagen and glycosaminoglycan) production. At a macroscopic level, cyclic stretching led to the most linear stress-stretch response, which was not related to the presence of shear stress. In conclusion, we have developed a bioreactor that is particularly suited to further unravel the interplay between hemodynamics and in situ tissue engineering processes. Using the new system, the present work highlights the importance of hemodynamic loading to the study of developing vascular tissues.

Soft tissue deformation estimation by spatio-temporal Kalman filter finite element method.

PubMed

Yarahmadian, Mehran; Zhong, Yongmin; Gu, Chengfan; Shin, Jaehyun

2018-01-01

Soft tissue modeling plays an important role in the development of surgical training simulators as well as in robot-assisted minimally invasive surgeries. It has been known that while the traditional Finite Element Method (FEM) promises the accurate modeling of soft tissue deformation, it still suffers from a slow computational process. This paper presents a Kalman filter finite element method to model soft tissue deformation in real time without sacrificing the traditional FEM accuracy. The proposed method employs the FEM equilibrium equation and formulates it as a filtering process to estimate soft tissue behavior using real-time measurement data. The model is temporally discretized using the Newmark method and further formulated as the system state equation. Simulation results demonstrate that the computational time of KF-FEM is approximately 10 times shorter than the traditional FEM and it is still as accurate as the traditional FEM. The normalized root-mean-square error of the proposed KF-FEM in reference to the traditional FEM is computed as 0.0116. It is concluded that the proposed method significantly improves the computational performance of the traditional FEM without sacrificing FEM accuracy. The proposed method also filters noises involved in system state and measurement data.

A case for poroelasticity in skeletal muscle finite element analysis: experiment and modeling.

PubMed

Wheatley, Benjamin B; Odegard, Gregory M; Kaufman, Kenton R; Haut Donahue, Tammy L

2017-05-01

Finite element models of skeletal muscle typically ignore the biphasic nature of the tissue, associating any time dependence with a viscoelastic formulation. In this study, direct experimental measurement of permeability was conducted as a function of specimen orientation and strain. A finite element model was developed to identify how various permeability formulations affect compressive response of the tissue. Experimental and modeling results suggest the assumption of a constant, isotropic permeability is appropriate. A viscoelastic only model differed considerably from a visco-poroelastic model, suggesting the latter is more appropriate for compressive studies.

A Finite-Element Method Model of Soft Tissue Response to Impulsive Acoustic Radiation Force

PubMed Central

Palmeri, Mark L.; Sharma, Amy C.; Bouchard, Richard R.; Nightingale, Roger W.; Nightingale, Kathryn R

2010-01-01

Several groups are studying acoustic radiation force and its ability to image the mechanical properties of tissue. Acoustic radiation force impulse (ARFI) imaging is one modality using standard diagnostic ultrasound scanners to generate localized, impulsive, acoustic radiation forces in tissue. The dynamic response of tissue is measured via conventional ultrasonic speckle-tracking methods and provides information about the mechanical properties of tissue. A finite-element method (FEM) model has been developed that simulates the dynamic response of tissues, with and without spherical inclusions, to an impulsive acoustic radiation force excitation from a linear array transducer. These FEM models were validated with calibrated phantoms. Shear wave speed, and therefore elasticity, dictates tissue relaxation following ARFI excitation, but Poisson’s ratio and density do not significantly alter tissue relaxation rates. Increased acoustic attenuation in tissue increases the relative amount of tissue displacement in the near field compared with the focal depth, but relaxation rates are not altered. Applications of this model include improving image quality, and distilling material and structural information from tissue’s dynamic response to ARFI excitation. Future work on these models includes incorporation of viscous material properties and modeling the ultrasonic tracking of displaced scatterers. PMID:16382621

LcMYB1 Is a Key Determinant of Differential Anthocyanin Accumulation among Genotypes, Tissues, Developmental Phases and ABA and Light Stimuli in Litchi chinensis

PubMed Central

Lai, Biao; Li, Xiao-Jing; Hu, Bing; Qin, Yong-Hua; Huang, Xu-Ming; Wang, Hui-Cong; Hu, Gui-Bing

2014-01-01

The red coloration of litchi fruit depends on the accumulation of anthocyanins. The anthocyanins level in litchi fruit varies widely among cultivars, developmental stages and environmental stimuli. Previous studies on various plant species demonstrate that anthocyanin biosynthesis is controlled at the transcriptional level. Here, we describe a litchi R2R3-MYB transcription factor gene, LcMYB1, which demonstrates a similar sequence as other known anthocyanin regulators. The transcription levels of the LcMYB1 and anthocyanin biosynthetic genes were investigated in samples with different anthocyanin levels. The expression of LcMYB1 was strongly associated with tissue anthocyanin content. LcMYB1 transcripts were only detected in anthocyanin-accumulating tissues and were positively correlated with anthocyanin accumulation in the pericarps of 12 genotypes. ABA and sunlight exposure promoted, whereas CPPU and bagging inhibited the expression of LcMYB1 and anthocyanin accumulation in the pericarp. Cis-elements associated with light responsiveness and abscisic acid responsiveness were identified in the promoter region of LcMYB1. Among the 6 structural genes tested, only LcUFGT was highly correlated with LcMYB1. These results suggest that LcMYB1 controls anthocyanin biosynthesis in litchi and LcUFGT might be the structural gene that is targeted and regulated by LcMYB1. Furthermore, the overexpression of LcMYB1 induced anthocyanin accumulation in all tissues in tobacco, confirming the function of LcMYB1 in the regulation of anthocyanin biosynthesis. The upregulation of NtAn1b in response to LcMYB1 overexpression seems to be essential for anthocyanin accumulation in the leaf and pedicel. In the reproductive tissues of transgenic tobacco, however, increased anthocyanin accumulation is independent of tobacco's endogenous MYB and bHLH transcriptional factors, but associated with the upregulation of specific structural genes. PMID:24466010

Differentiating characteristic microstructural features of cancerous tissues using Mueller matrix microscope.

PubMed

Wang, Ye; He, Honghui; Chang, Jintao; Zeng, Nan; Liu, Shaoxiong; Li, Migao; Ma, Hui

2015-12-01

Polarized light imaging can provide rich microstructural information of samples, and has been applied to the detections of various abnormal tissues. In this paper, we report a polarized light microscope based on Mueller matrix imaging by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission optical microscope. The maximum errors for the absolute values of Mueller matrix elements are reduced to 0.01 after calibration. This Mueller matrix microscope has been used to examine human cervical and liver cancerous tissues with fibrosis. Images of the transformed Mueller matrix parameters provide quantitative assessment on the characteristic features of the pathological tissues. Contrast mechanism of the experimental results are backed up by Monte Carlo simulations based on the sphere-cylinder birefringence model, which reveal the relationship between the pathological features in the cancerous tissues at the cellular level and the polarization parameters. Both the experimental and simulated data indicate that the microscopic transformed Mueller matrix parameters can distinguish the breaking down of birefringent normal tissues for cervical cancer, or the formation of birefringent surrounding structures accompanying the inflammatory reaction for liver cancer. With its simple structure, fast measurement and high precision, polarized light microscope based on Mueller matrix shows a good diagnosis application prospect. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cryotherapy simulator for localized prostate cancer.

PubMed

Hahn, James K; Manyak, Michael J; Jin, Ge; Kim, Dongho; Rewcastle, John; Kim, Sunil; Walsh, Raymond J

2002-01-01

Cryotherapy is a treatment modality that uses a technique to selectively freeze tissue and thereby cause controlled tissue destruction. The procedure involves placement of multiple small diameter probes through the perineum into the prostate tissue at selected spatial intervals. Transrectal ultrasound is used to properly position the cylindrical probes before activation of the liquid Argon cooling element, which lowers the tissue temperature below -40 degrees Centigrade. Tissue effect is monitored by transrectal ultrasound changes as well as thermocouples placed in the tissue. The computer-based cryotherapy simulation system mimics the major surgical steps involved in the procedure. The simulated real-time ultrasound display is generated from 3-D ultrasound datasets where the interaction of the ultrasound with the instruments as well as the frozen tissue is simulated by image processing. The thermal and mechanical simulations of the tissue are done using a modified finite-difference/finite-element method optimized for real-time performance. The simulator developed is a part of a comprehensive training program, including a computer-based learning system and hands-on training program with a proctor, designed to familiarize the physician with the technique and equipment involved.

Thermal modeling of lesion growth with radiofrequency ablation devices

PubMed Central

Chang, Isaac A; Nguyen, Uyen D

2004-01-01

Background Temperature is a frequently used parameter to describe the predicted size of lesions computed by computational models. In many cases, however, temperature correlates poorly with lesion size. Although many studies have been conducted to characterize the relationship between time-temperature exposure of tissue heating to cell damage, to date these relationships have not been employed in a finite element model. Methods We present an axisymmetric two-dimensional finite element model that calculates cell damage in tissues and compare lesion sizes using common tissue damage and iso-temperature contour definitions. The model accounts for both temperature-dependent changes in the electrical conductivity of tissue as well as tissue damage-dependent changes in local tissue perfusion. The data is validated using excised porcine liver tissues. Results The data demonstrate the size of thermal lesions is grossly overestimated when calculated using traditional temperature isocontours of 42°C and 47°C. The computational model results predicted lesion dimensions that were within 5% of the experimental measurements. Conclusion When modeling radiofrequency ablation problems, temperature isotherms may not be representative of actual tissue damage patterns. PMID:15298708

Numerical impact simulation of gradually increased kinetic energy transfer has the potential to break up folded protein structures resulting in cytotoxic brain tissue edema.

PubMed

von Holst, Hans; Li, Xiaogai

2013-07-01

Although the consequences of traumatic brain injury (TBI) and its treatment have been improved, there is still a substantial lack of understanding the mechanisms. Numerical simulation of the impact can throw further lights on site and mechanism of action. A finite element model of the human head and brain tissue was used to simulate TBI. The consequences of gradually increased kinetic energy transfer was analyzed by evaluating the impact intracranial pressure (ICP), strain level, and their potential influences on binding forces in folded protein structures. The gradually increased kinetic energy was found to have the potential to break apart bonds of Van der Waals in all impacts and hydrogen bonds at simulated impacts from 6 m/s and higher, thereby superseding the energy in folded protein structures. Further, impacts below 6 m/s showed none or very slight increase in impact ICP and strain levels, whereas impacts of 6 m/s or higher showed a gradual increase of the impact ICP and strain levels reaching over 1000 KPa and over 30%, respectively. The present simulation study shows that the free kinetic energy transfer, impact ICP, and strain levels all have the potential to initiate cytotoxic brain tissue edema by unfolding protein structures. The definition of mild, moderate, and severe TBI should thus be looked upon as the same condition and separated only by a gradual severity of impact.

3-d finite element model development for biomechanics: a software demonstration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollerbach, K.; Hollister, A.M.; Ashby, E.

1997-03-01

Finite element analysis is becoming an increasingly important part of biomechanics and orthopedic research, as computational resources become more powerful, and data handling algorithms become more sophisticated. Until recently, tools with sufficient power did not exist or were not accessible to adequately model complicated, three-dimensional, nonlinear biomechanical systems. In the past, finite element analyses in biomechanics have often been limited to two-dimensional approaches, linear analyses, or simulations of single tissue types. Today, we have the resources to model fully three-dimensional, nonlinear, multi-tissue, and even multi-joint systems. The authors will present the process of developing these kinds of finite element models,more » using human hand and knee examples, and will demonstrate their software tools.« less

The Co-Induced Effects of Molybdenum and Cadmium on the Trace Elements and the mRNA Expression Levels of CP and MT in Duck Testicles.

PubMed

Xia, Bing; Chen, Hua; Hu, Guoliang; Wang, Liqi; Cao, Huabin; Zhang, Caiying

2016-02-01

To investigate the chronic toxicity of molybdenum (Mo) and cadmium (Cd) on the trace elements and the mRNA expression levels of ceruloplasmin (CP) and metallothionein (MT) in duck testicles, 120 healthy 11-day-old male ducks were randomly divided into six groups with 20 ducks in each group. Ducks were treated with the diet containing different dosages of Mo or Cd. The source of Mo and Cd was hexaammonium molybdate ([(NH4)6Mo7O24·4H2O]) and cadmium sulfate (3CdSO4·8H2O), respectively, in this study. After being treated for 60 and 120 days, ten male birds in each group were randomly selected and euthanized and then testicles were aseptically collected for determining the mRNA expression levels of MT and CP, antioxidant indexes, and contents of trace elements in the testicle. In addition, testicle tissues at 120 days were subjected to histopathological analysis with the optical microscope. The results showed that co-exposure to Mo and Cd resulted in an increase in malondialdehyde (MDA) level while decrease in xanthine oxidase (XOD) and catalase (CAT) activities. The mRNA expression level of MT gene was upregulated while CP was decreased in combination groups. Contents of Mo, copper (Cu), iron (Fe), and zinc (Zn) decreased in combined groups while Cd increased in Cd and combined groups at 120 days. Furthermore, severe congestion, low sperm count, and malformation were observed in low dietary of Mo combined with Cd group and high dietary of Mo combined with Cd group. Our results suggested that Mo and Cd might aggravate testicular degeneration synergistically through altering the mRNA expression levels of MT and CP, increasing lipid peroxidation through inhibiting related enzyme activities and disturbing homeostasis of trace elements in testicles. Interaction of Mo and Cd may have a synergistic effect on the testicular toxicity.

Tissue- and Time-Specific Expression of Otherwise Identical tRNA Genes

PubMed Central

Adir, Idan; Dahan, Orna; Broday, Limor; Pilpel, Yitzhak; Rechavi, Oded

2016-01-01

Codon usage bias affects protein translation because tRNAs that recognize synonymous codons differ in their abundance. Although the current dogma states that tRNA expression is exclusively regulated by intrinsic control elements (A- and B-box sequences), we revealed, using a reporter that monitors the levels of individual tRNA genes in Caenorhabditis elegans, that eight tryptophan tRNA genes, 100% identical in sequence, are expressed in different tissues and change their expression dynamically. Furthermore, the expression levels of the sup-7 tRNA gene at day 6 were found to predict the animal’s lifespan. We discovered that the expression of tRNAs that reside within introns of protein-coding genes is affected by the host gene’s promoter. Pairing between specific Pol II genes and the tRNAs that are contained in their introns is most likely adaptive, since a genome-wide analysis revealed that the presence of specific intronic tRNAs within specific orthologous genes is conserved across Caenorhabditis species. PMID:27560950

Regulation of Auxin Homeostasis and Gradients in Arabidopsis Roots through the Formation of the Indole-3-Acetic Acid Catabolite 2-Oxindole-3-Acetic Acid[C][W][OPEN

PubMed Central

Pěnčík, Aleš; Simonovik, Biljana; Petersson, Sara V.; Henyková, Eva; Simon, Sibu; Greenham, Kathleen; Zhang, Yi; Kowalczyk, Mariusz; Estelle, Mark; Zažímalová, Eva; Novák, Ondřej; Sandberg, Göran; Ljung, Karin

2013-01-01

The native auxin, indole-3-acetic acid (IAA), is a major regulator of plant growth and development. Its nonuniform distribution between cells and tissues underlies the spatiotemporal coordination of many developmental events and responses to environmental stimuli. The regulation of auxin gradients and the formation of auxin maxima/minima most likely involve the regulation of both metabolic and transport processes. In this article, we have demonstrated that 2-oxindole-3-acetic acid (oxIAA) is a major primary IAA catabolite formed in Arabidopsis thaliana root tissues. OxIAA had little biological activity and was formed rapidly and irreversibly in response to increases in auxin levels. We further showed that there is cell type–specific regulation of oxIAA levels in the Arabidopsis root apex. We propose that oxIAA is an important element in the regulation of output from auxin gradients and, therefore, in the regulation of auxin homeostasis and response mechanisms. PMID:24163311

Computational Modeling of Airway and Pulmonary Vascular Structure and Function: Development of a “Lung Physiome”

PubMed Central

Tawhai, M. H.; Clark, A. R.; Donovan, G. M.; Burrowes, K. S.

2011-01-01

Computational models of lung structure and function necessarily span multiple spatial and temporal scales, i.e., dynamic molecular interactions give rise to whole organ function, and the link between these scales cannot be fully understood if only molecular or organ-level function is considered. Here, we review progress in constructing multiscale finite element models of lung structure and function that are aimed at providing a computational framework for bridging the spatial scales from molecular to whole organ. These include structural models of the intact lung, embedded models of the pulmonary airways that couple to model lung tissue, and models of the pulmonary vasculature that account for distinct structural differences at the extra- and intra-acinar levels. Biophysically based functional models for tissue deformation, pulmonary blood flow, and airway bronchoconstriction are also described. The development of these advanced multiscale models has led to a better understanding of complex physiological mechanisms that govern regional lung perfusion and emergent heterogeneity during bronchoconstriction. PMID:22011236

SULT2B1b Sulfotransferase: Induction by Vitamin D Receptor and Reduced Expression in Prostate Cancer

PubMed Central

Seo, Young-Kyo; Mirkheshti, Nooshin; Song, Chung S.; Kim, Soyoung; Dodds, Sherry; Ahn, Soon C.; Christy, Barbara; Mendez-Meza, Rosario; Ittmann, Michael M.; Abboud-Werner, Sherry

2013-01-01

An elevated tumor tissue androgen level, which reactivates androgen receptor in recurrent prostate cancer, arises from the intratumor synthesis of 5α-dihydrotestosterone through use of the precursor steroid dehydroepiandrosterone (DHEA) and is fueled by the steroidogenic enzymes 3β-hydroxysteroid dehydrogenase (3β-HSD1), aldoketoreductase (AKR1C3), and steroid 5-alpha reductase, type 1 (SRD5A1) present in cancer tissue. Sulfotransferase 2B1b (SULT2B1b) (in short, SULT2B) is a prostate-expressed hydroxysteroid SULT that converts cholesterol, oxysterols, and DHEA to 3β-sulfates. DHEA metabolism involving sulfonation by SULT2B can potentially interfere with intraprostate androgen synthesis due to reduction of free DHEA pool and, thus, conversion of DHEA to androstenedione. Here we report that in prostatectomy specimens from treatment-naive patients, SULT2B expression is markedly reduced in malignant tissue (P < .001, Mann-Whitney U test) compared with robust expression in adjacent nonmalignant glands. SULT2B was detected in formalin-fixed specimens by immunohistochemistry on individual sections and tissue array. Immunoblotting of protein lysates of frozen cancer and matched benign tissue confirmed immunohistochemistry results. An in-house–developed rabbit polyclonal antibody against full-length human SULT2B was validated for specificity and used in the analyses. Ligand-activated vitamin D receptor induced the SULT2B1 promoter in vivo in mouse prostate and increased SULT2B mRNA and protein levels in vitro in prostate cancer cells. A vitamin D receptor/retinoid X receptor-α–bound DNA element (with a DR7 motif) mediated induction of the transfected SULT2B1 promoter in calcitriol-treated cells. SULT2B knockdown caused an increased proliferation rate of prostate cancer cells upon stimulation by DHEA. These results suggest that the tumor tissue SULT2B level may partly control prostate cancer growth, and its induction in a therapeutic setting may inhibit disease progression. PMID:23579488

The influence of implantoplasty on the diameter, chemical surface composition, and biocompatibility of titanium implants.

PubMed

Schwarz, Frank; John, Gordon; Becker, Jürgen

2017-09-01

The objective of the study was to assess the influence of implantoplasty (IP) on the diameter, chemical surface composition, and biocompatibility of titanium implants in vitro. Twenty soft tissue-level (TL; machined transmucosal-M and rough endosseous part-SLA) and 20 bone-level (BL; SLA) implants were allocated to IP covering 3 or 6 mm of the structured surface (SLA) area. The samples were subjected to diameter, energy-dispersive X-ray spectroscopy (EDX), and cell viability (ginigval fibroblasts, 6 days) assessments. Median diameter reductions varied between 0.1 (TL 3 mm) and 0.2 mm (TL 6 mm). EDX analysis revealed that IP and M surfaces were characterized by a comparable quantity (Wt%) of elements C, O, Na, Cl, K, and Si, but a significantly different quantity of elements Ti and Al. When compared to SLA surfaces, significant differences were noted for elements C, O, Na, Ti, and Al. At BL implants, the extension of IP (i.e., 3 to 6 mm) was associated with a significant increase in cell viability. IP applied to SLA implants was associated with (i) a minimal diameter reduction, (ii) an undisturbed cell viability, and (iii) a chemical elemental composition comparable to M surfaces. This specific IP procedure appears to be suitable for the management of exposed SLA implant surfaces.

Transcriptional regulation of hepatic lipogenesis.

PubMed

Wang, Yuhui; Viscarra, Jose; Kim, Sun-Joong; Sul, Hei Sook

2015-11-01

Fatty acid and fat synthesis in the liver is a highly regulated metabolic pathway that is important for very low-density lipoprotein (VLDL) production and thus energy distribution to other tissues. Having common features at their promoter regions, lipogenic genes are coordinately regulated at the transcriptional level. Transcription factors, such as upstream stimulatory factors (USFs), sterol regulatory element-binding protein 1C (SREBP1C), liver X receptors (LXRs) and carbohydrate-responsive element-binding protein (ChREBP) have crucial roles in this process. Recently, insights have been gained into the signalling pathways that regulate these transcription factors. After feeding, high blood glucose and insulin levels activate lipogenic genes through several pathways, including the DNA-dependent protein kinase (DNA-PK), atypical protein kinase C (aPKC) and AKT-mTOR pathways. These pathways control the post-translational modifications of transcription factors and co-regulators, such as phosphorylation, acetylation or ubiquitylation, that affect their function, stability and/or localization. Dysregulation of lipogenesis can contribute to hepatosteatosis, which is associated with obesity and insulin resistance.

The beneficial effects of exercise on cartilage are lost in mice with reduced levels of ECSOD in tissues.

PubMed

Pate, Kathryn M; Sherk, Vanessa D; Carpenter, R Dana; Weaver, Michael; Crapo, Silvia; Gally, Fabienne; Chatham, Lillian S; Goldstrohm, David A; Crapo, James D; Kohrt, Wendy M; Bowler, Russell P; Oberley-Deegan, Rebecca E; Regan, Elizabeth A

2015-03-15

Osteoarthritis (OA) is associated with increased mechanical damage to joint cartilage. We have previously found that extracellular superoxide dismutase (ECSOD) is decreased in OA joint fluid and cartilage, suggesting oxidant damage may play a role in OA. We explored the effect of forced running as a surrogate for mechanical damage in a transgenic mouse with reduced ECSOD tissue binding. Transgenic mice heterozygous (Het) for the human ECSOD R213G polymorphism and 129-SvEv (wild-type, WT) mice were exposed to forced running on a treadmill for 45 min/day, 5 days/wk, over 8 wk. At the end of the running protocol, knee joint tissue was obtained for histology, immunohistochemistry, and protein analysis. Sedentary Het and WT mice were maintained for comparison. Whole tibias were studied for bone morphometry, finite element analysis, and mechanical testing. Forced running improved joint histology in WT mice. However, when ECSOD levels were reduced, this beneficial effect with running was lost. Het ECSOD runner mice had significantly worse histology scores compared with WT runner mice. Runner mice for both strains had increased bone strength in response to the running protocol, while Het mice showed evidence of a less robust bone structure in both runners and untrained mice. Reduced levels of ECSOD in cartilage produced joint damage when joints were stressed by forced running. The bone tissues responded to increased loading with hypertrophy, regardless of mouse strain. We conclude that ECSOD plays an important role in protecting cartilage from damage caused by mechanical loading. Copyright © 2015 the American Physiological Society.

Recent advances in computational mechanics of the human knee joint.

PubMed

Kazemi, M; Dabiri, Y; Li, L P

2013-01-01

Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling.

On the effects of leaflet microstructure and constitutive model on the closing behavior of the mitral valve

PubMed Central

Lee, Chung-Hao; Rabbah, Jean-Pierre; Yoganathan, Ajit P.; Gorman, Robert C.; Gorman, Joseph H.

2016-01-01

Recent long-term studies showed an unsatisfactory recurrence rate of severe mitral regurgitation 3–5 years after surgical repair, suggesting that excessive tissue stresses and the resulting strain-induced tissue failure are potential etiological factors controlling the success of surgical repair for treating mitral valve (MV) diseases. We hypothesized that restoring normal MV tissue stresses in MV repair techniques would ultimately lead to improved repair durability through the restoration of MV normal homeostatic state. Therefore, we developed a micro- and macro- anatomically accurate MV finite element model by incorporating actual fiber microstructural architecture and a realistic structure-based constitutive model. We investigated MV closing behaviors, with extensive in vitro data used for validating the proposed model. Comparative and parametric studies were conducted to identify essential model fidelity and information for achieving desirable accuracy. More importantly, for the first time, the interrelationship between the local fiber ensemble behavior and the organ-level MV closing behavior was investigated using a computational simulation. These novel results indicated not only the appropriate parameter ranges, but also the importance of the microstructural tuning (i.e., straightening and re-orientation) of the collagen/elastin fiber networks at the macroscopic tissue level for facilitating the proper coaptation and natural functioning of the MV apparatus under physiological loading at the organ level. The proposed computational model would serve as a logical first step toward our long-term modeling goal—facilitating simulation-guided design of optimal surgical repair strategies for treating diseased MVs with significantly enhanced durability. PMID:25947879

Recent Advances in Computational Mechanics of the Human Knee Joint

PubMed Central

Kazemi, M.; Dabiri, Y.; Li, L. P.

2013-01-01

Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling. PMID:23509602

Quantification of differences in the effective atomic numbers of healthy and cancerous tissues: A discussion in the context of diagnostics and dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, M. L.; Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne 3001

Purpose: There are a range of genetic and nongenetic factors influencing the elemental composition of different human tissues. The elemental composition of cancerous tissues frequently differs from healthy tissue of the same organ, particularly in high-Z trace element concentrations. For this reason, one could suggest that this may be exploited in diagnostics and perhaps even influence dosimetry. Methods: In this work, for the first time, effective atomic numbers are computed for common cancerous and healthy tissues using a robust, energy-dependent approach between 10 keV and 100 MeV. These are then quantitatively compared within the context of diagnostics and dosimetry. Results:more » Differences between effective atomic numbers of healthy and diseased tissues are found to be typically less than 10%. Fibrotic tissues and calcifications of the breast exhibit substantial (tens to hundreds of percent) differences to healthy tissue. Expectedly, differences are most pronounced in the photoelectric regime and consequently most relevant for kV imaging/therapy and radionuclides with prominent low-energy peaks. Cancerous tissue of the testes and stomach have lower effective atomic numbers than corresponding healthy tissues, while diseased tissues of the other organ sites typically have higher values. Conclusions: As dose calculation approaches improve in accuracy, there may be an argument for the explicit inclusion of pathologies. This is more the case for breast, penile, prostate, nasopharyngeal, and stomach cancer, less so for testicular and kidney cancer. The calculated data suggest dual-energy computed tomography could potentially improve lesion identification in the aforementioned organs (with the exception of testicular cancer), with most import in breast imaging. Ultimately, however, the differences are very small. It is likely that the assumption of a generic 'tissue ramp' in planning will be sufficient for the foreseeable future, and that the Z differences do not notably aid lesion detection beyond that already facilitated by differences in mass density.« less

Trace Metals in Noah's Ark Shells (Arca noae Linnaeus, 1758): Impact of Tourist Season and Human Health Risk.

PubMed

Ivanković, Dušica; Erk, Marijana; Župan, Ivan; Čulin, Jelena; Dragun, Zrinka; Bačić, Niko; Cindrić, Ana-Marija

2016-10-01

Commercially important bivalve Noah's Ark shell (Arca noae Linnaeus, 1758) represents a high-quality seafood product, but the data on levels of metal contaminants that could pose a human health risk and also on some essential elements that are important for health protection are lacking. This study examined the concentrations of Cd, Pb, Cr, Ni, Cu, Co, and Zn in the soft tissue of A. noae from harvesting area in the central Adriatic Sea, to survey whether heavy metals are within the acceptable limits for public health and whether tourism could have an impact on them. The concentrations of analysed metals varied for Cd: 0.15-0.74, Pb: 0.06-0.26, Cr: 0.11-0.34, Ni: 0.09-0.22, Cu: 0.65-1.95, Co: 0.04-0.09, and Zn: 18.3-74.7 mg/kg wet weight. These levels were lower than the permissible limits for safe consummation of seafood, and only for Cd, some precautions should be taken into account if older shellfish were consumed. Increase of Cd, Cr, and Cu in shell tissue was observed during the tourist season at the site closest to the marine traffic routes, indicating that metal levels in shellfish tissue should be monitored especially carefully during the peak tourist season to prevent eventual toxic effects due to increased intake of metals, specifically of Cd.

From single fiber to macro-level mechanics: A structural finite-element model for elastomeric fibrous biomaterials.

PubMed

D'Amore, Antonio; Amoroso, Nicholas; Gottardi, Riccardo; Hobson, Christopher; Carruthers, Christopher; Watkins, Simon; Wagner, William R; Sacks, Michael S

2014-11-01

In the present work, we demonstrate that the mesoscopic in-plane mechanical behavior of membrane elastomeric scaffolds can be simulated by replication of actual quantified fibrous geometries. Elastomeric electrospun polyurethane (ES-PEUU) scaffolds, with and without particulate inclusions, were utilized. Simulations were developed from experimentally-derived fiber network geometries, based on a range of scaffold isotropic and anisotropic behaviors. These were chosen to evaluate the effects on macro-mechanics based on measurable geometric parameters such as fiber intersections, connectivity, orientation, and diameter. Simulations were conducted with only the fiber material model parameters adjusted to match the macro-level mechanical test data. Fiber model validation was performed at the microscopic level by individual fiber mechanical tests using AFM. Results demonstrated very good agreement to the experimental data, and revealed the formation of extended preferential fiber orientations spanning the entire model space. We speculate that these emergent structures may be responsible for the tissue-like macroscale behaviors observed in electrospun scaffolds. To conclude, the modeling approach has implications for (1) gaining insight on the intricate relationship between fabrication variables, structure, and mechanics to manufacture more functional devices/materials, (2) elucidating the effects of cell or particulate inclusions on global construct mechanics, and (3) fabricating better performing tissue surrogates that could recapitulate native tissue mechanics. Copyright © 2014 Elsevier Ltd. All rights reserved.

A comparative study of the effectiveness of early and delayed loading of short tissue-level dental implants with hydrophilic surfaces placed in the posterior section of the mandible-A preliminary study.

PubMed

Makowiecki, Arkadiusz; Botzenhart, Ute; Seeliger, Julia; Heinemann, Friedhelm; Biocev, Peter; Dominiak, Marzena

2017-07-01

The objective of the present study was to compare the primary and secondary stability of tissue-level short dental titanium implants with polished necks and hydrophilic surfaces of two different designs and manufacturers. The first implant system used (SPI ® ELEMENT RC INICELL titanium implants, Thommen Medical AG, Grenchen, Switzerland), allowed functional loading 6 weeks after its placement, whereas the second implant system (RN SLActiv ® tissue-level titanium implants, Straumann GmbH, Fribourg, Germany), was loaded after 15 weeks. The degree of primary and secondary stability was determined using an Osstell ISQ measuring device. Marginal bone loss (MBL) was evaluated radiographically 12 and 24 weeks after implantation and the Wachtel's healing index as well as the patient's satisfaction with the treatment was registered on a VAS scale. The intergroup comparison revealed significant differences in terms of primary stability as well as differences in MBL 3 months after the procedure, but no significant differences could be found after 6 months and for secondary stability. The primary stability was significantly higher for Thommen ® compared to Straumann ® implants. Insertion of short dental implants with a hydrophilic conditioned surface significantly shortens patient treatment time. Copyright © 2017 Elsevier GmbH. All rights reserved.

Predicting cell viability within tissue scaffolds under equiaxial strain: multi-scale finite element model of collagen-cardiomyocytes constructs.

PubMed

Elsaadany, Mostafa; Yan, Karen Chang; Yildirim-Ayan, Eda

2017-06-01

Successful tissue engineering and regenerative therapy necessitate having extensive knowledge about mechanical milieu in engineered tissues and the resident cells. In this study, we have merged two powerful analysis tools, namely finite element analysis and stochastic analysis, to understand the mechanical strain within the tissue scaffold and residing cells and to predict the cell viability upon applying mechanical strains. A continuum-based multi-length scale finite element model (FEM) was created to simulate the physiologically relevant equiaxial strain exposure on cell-embedded tissue scaffold and to calculate strain transferred to the tissue scaffold (macro-scale) and residing cells (micro-scale) upon various equiaxial strains. The data from FEM were used to predict cell viability under various equiaxial strain magnitudes using stochastic damage criterion analysis. The model validation was conducted through mechanically straining the cardiomyocyte-encapsulated collagen constructs using a custom-built mechanical loading platform (EQUicycler). FEM quantified the strain gradients over the radial and longitudinal direction of the scaffolds and the cells residing in different areas of interest. With the use of the experimental viability data, stochastic damage criterion, and the average cellular strains obtained from multi-length scale models, cellular viability was predicted and successfully validated. This methodology can provide a great tool to characterize the mechanical stimulation of bioreactors used in tissue engineering applications in providing quantification of mechanical strain and predicting cellular viability variations due to applied mechanical strain.

Trace element levels in mollusks from clean and polluted coastal marine sites in the Mediterranean, Red and North Seas

NASA Astrophysics Data System (ADS)

Herut, Barak; Kress, Nurit; Shefer, Edna; Hornung, Hava

1999-12-01

The trace element contamination levels in mollusks were evaluated for different marine coastal sites in the Mediterranean (Israeli coast), Red (Israeli coast) and North (German coast) Seas. Three bivalve species (Mactra corallina, Donax sp, and Mytilus edulis) and two gastropod species (Patella sp.and Cellana rota) were sampled at polluted and relatively clean sites, and their soft tissue analyzed for Hg, Cd, Zn, Cu, Mn and Fe concentrations. Representative samples were screened for organic contaminants [(DDE), polychlorinated biphenyls PCBs and polycyclic aromatic hydrocarbons (PAHs)] which exhibited very low concentrations at all sites. In the Red Sea, the gastropod C. rota showed low levels of Hg (below detection limit) and similar Cd concentrations at all the examined sites, while other trace elements (Cu, Zn, Mn, Fe) were slightly enriched at the northern beach stations. Along the Mediterranean coast of Israel, Hg and Zn were enriched in two bivalves (M. corallina and Donax sp.) from Haifa Bay, both species undergoing a long-term decrease in Hg based on previous studies. Significant Cd and Zn enrichment was detected in Patella sp. from the Kishon River estuary at the southern part of Haifa Bay. In general, Patella sp. and Donax sp. specimens from Haifa Bay exhibited higher levels of Cd compared to other sites along the Israeli Mediterranean coast, attributed to the enrichment of Cd in suspended particulate matter. Along the German coast (North Sea) M. edulis exhibited higher concentrations of Hg and Cd at the Elbe and Eider estuaries, but with levels below those found in polluted sites elsewhere.

A hybrid computational model to explore the topological characteristics of epithelial tissues.

PubMed

González-Valverde, Ismael; García-Aznar, José Manuel

2017-11-01

Epithelial tissues show a particular topology where cells resemble a polygon-like shape, but some biological processes can alter this tissue topology. During cell proliferation, mitotic cell dilation deforms the tissue and modifies the tissue topology. Additionally, cells are reorganized in the epithelial layer and these rearrangements also alter the polygon distribution. We present here a computer-based hybrid framework focused on the simulation of epithelial layer dynamics that combines discrete and continuum numerical models. In this framework, we consider topological and mechanical aspects of the epithelial tissue. Individual cells in the tissue are simulated by an off-lattice agent-based model, which keeps the information of each cell. In addition, we model the cell-cell interaction forces and the cell cycle. Otherwise, we simulate the passive mechanical behaviour of the cell monolayer using a material that approximates the mechanical properties of the cell. This continuum approach is solved by the finite element method, which uses a dynamic mesh generated by the triangulation of cell polygons. Forces generated by cell-cell interaction in the agent-based model are also applied on the finite element mesh. Cell movement in the agent-based model is driven by the displacements obtained from the deformed finite element mesh of the continuum mechanical approach. We successfully compare the results of our simulations with some experiments about the topology of proliferating epithelial tissues in Drosophila. Our framework is able to model the emergent behaviour of the cell monolayer that is due to local cell-cell interactions, which have a direct influence on the dynamics of the epithelial tissue. Copyright © 2017 John Wiley & Sons, Ltd.

Computational Identification of Tissue-Specific Splicing Regulatory Elements in Human Genes from RNA-Seq Data.

PubMed

Badr, Eman; ElHefnawi, Mahmoud; Heath, Lenwood S

2016-01-01

Alternative splicing is a vital process for regulating gene expression and promoting proteomic diversity. It plays a key role in tissue-specific expressed genes. This specificity is mainly regulated by splicing factors that bind to specific sequences called splicing regulatory elements (SREs). Here, we report a genome-wide analysis to study alternative splicing on multiple tissues, including brain, heart, liver, and muscle. We propose a pipeline to identify differential exons across tissues and hence tissue-specific SREs. In our pipeline, we utilize the DEXSeq package along with our previously reported algorithms. Utilizing the publicly available RNA-Seq data set from the Human BodyMap project, we identified 28,100 differentially used exons across the four tissues. We identified tissue-specific exonic splicing enhancers that overlap with various previously published experimental and computational databases. A complicated exonic enhancer regulatory network was revealed, where multiple exonic enhancers were found across multiple tissues while some were found only in specific tissues. Putative combinatorial exonic enhancers and silencers were discovered as well, which may be responsible for exon inclusion or exclusion across tissues. Some of the exonic enhancers are found to be co-occurring with multiple exonic silencers and vice versa, which demonstrates a complicated relationship between tissue-specific exonic enhancers and silencers.

Simulation study of interaction of pulse laser with tumor-embedded gastric tissue using finite element analysis

NASA Astrophysics Data System (ADS)

Liu, Lantian; Li, Zhifang; Li, Hui

2018-01-01

The study of interaction of laser with tumor-embedded gastric tissue is of great theoretical and practical significance for the laser diagnosis and treatment of gastric cancer in medicine. A finite element (FE)-based simulation model has been developed incorporating light propagation and heat transfer in soft tissues using a commercial FE simulation package, COMSOL Multiphysics. In this study, FE model is composed of three parts of 1) homogeneous background soft tissues submerged in water, 2) tumor tissue inclusion, and 3) different wavelengths of short pulsed laser source (450nm, 550nm, 632nm and 800nm). The laser point source is placed right under the tissues submerged in water. This laser source light propagation through the multi-layer tissues using the diffusion equation and bioheat transfer in tissues is simulated using bioheat equation for temperature change. The simulation results show that the penetration depth and light energy distribution mainly depend on the optical parameters of the different wavelengths of the tissue. In the process of biological heat transfer, the temperature of the tissue decreases exponentially with the depth and the deep tissues are almost unaffected. The results are helpful to optimize the laser source in a photoacoustic imaging system and provide some significance for the further study of the early diagnosis of gastric cancer.

Regenerative endodontics as a tissue engineering approach: past, current and future.

PubMed

Malhotra, Neeraj; Mala, Kundabala

2012-12-01

With the reported startling statistics of high incidence of tooth decay and tooth loss, the current interest is focused on the development of alternate dental tissue replacement therapies. This has led to the application of dental tissue engineering as a clinically relevant method for the regeneration of dental tissues and generation of bioengineered whole tooth. Although, tissue engineering approach requires the three main key elements of stem cells, scaffold and morphogens, a conductive environment (fourth element) is equally important for successful engineering of any tissue and/or organ. The applications of this science has evolved continuously in dentistry, beginning from the application of Ca(OH)(2) in vital pulp therapy to the development of a fully functional bioengineered tooth (mice). Thus, with advances in basic research, recent reports and studies have shown successful application of tissue engineering in the field of dentistry. However, certain practical obstacles are yet to be overcome before dental tissue regeneration can be applied as evidence-based approach in clinics. The article highlights on the past achievements, current developments and future prospects of tissue engineering and regenerative therapy in the field of endodontics and bioengineered teeth (bioteeth). © 2012 The Authors. Australian Endodontic Journal © 2012 Australian Society of Endodontology.

Effect of bacoside A on brain antioxidant status in cigarette smoke exposed rats.

PubMed

Anbarasi, K; Vani, G; Balakrishna, K; Devi, C S Shyamala

2006-02-16

Free radicals mediated oxidative stress has been implicated in the pathogenesis of smoking-related diseases and antioxidant nutrients are reported to prevent the oxidative damage induced by smoking. Therefore, the present study was conducted to evaluate the antioxidant role of bacoside A (triterpenoid saponin isolated from Bacopa monniera) against chronic cigarette smoking induced oxidative damage in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with bacoside A (10 mg/kg b.w./day, p.o.). Antioxidant status of the brain was assessed from the levels of reduced glutathione, vitamin C, vitamin E, and vitamin A and the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The levels of copper, iron, zinc and selenium in brain and serum ceruloplasmin activity were also measured. Oxidative stress was evident from the diminished levels of both enzymatic and non-enzymatic antioxidants. Alterations in the levels of trace elements with accumulation of copper and iron, and depletion of zinc and selenium were also observed. Bacoside A administration improved the antioxidant status and maintained the levels of trace elements. These results suggest that chronic cigarette smoke exposure enhances oxidative stress, thereby disturbing the tissue defense system and bacoside A protects the brain from the oxidative damage through its antioxidant potential.

Cartilage and bone cells do not participate in skeletal regeneration in Ambystoma mexicanum limbs.

PubMed

McCusker, Catherine D; Diaz-Castillo, Carlos; Sosnik, Julian; Q Phan, Anne; Gardiner, David M

2016-08-01

The Mexican Axolotl is one of the few tetrapod species that is capable of regenerating complete skeletal elements in injured adult limbs. Whether the skeleton (bone and cartilage) plays a role in the patterning and contribution to the skeletal regenerate is currently unresolved. We tested the induction of pattern formation, the effect on cell proliferation, and contributions of skeletal tissues (cartilage, bone, and periosteum) to the regenerating axolotl limb. We found that bone tissue grafts from transgenic donors expressing GFP fail to induce pattern formation and do not contribute to the newly regenerated skeleton. Periosteum tissue grafts, on the other hand, have both of these activities. These observations reveal that skeletal tissue does not contribute to the regeneration of skeletal elements; rather, these structures are patterned by and derived from cells of non-skeletal connective tissue origin. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrosurgical vessel sealing tissue temperature: experimental measurement and finite element modeling.

PubMed

Chen, Roland K; Chastagner, Matthew W; Dodde, Robert E; Shih, Albert J

2013-02-01

The temporal and spatial tissue temperature profile in electrosurgical vessel sealing was experimentally measured and modeled using finite element modeling (FEM). Vessel sealing procedures are often performed near the neurovascular bundle and may cause collateral neural thermal damage. Therefore, the heat generated during electrosurgical vessel sealing is of concern among surgeons. Tissue temperature in an in vivo porcine femoral artery sealed using a bipolar electrosurgical device was studied. Three FEM techniques were incorporated to model the tissue evaporation, water loss, and fusion by manipulating the specific heat, electrical conductivity, and electrical contact resistance, respectively. These three techniques enable the FEM to accurately predict the vessel sealing tissue temperature profile. The averaged discrepancy between the experimentally measured temperature and the FEM predicted temperature at three thermistor locations is less than 7%. The maximum error is 23.9%. Effects of the three FEM techniques are also quantified.

Early diagnostics of temporomandibular joint structural elements injures caused by traumatic mandibular bone fractures.

PubMed

Pohranychna, Kh R; Stasyshyn, A R; Matolych, U D

2017-06-30

A rapidly increasing number of mandibular condylar fractures and some complications related to injuries of temporomandibular elements make this study important. Intra-articular disorders lead to secondary pathological findings such as osteoarthritis, deforming osteoarthrosis, and temporomandibular joint ankylosis that limits mouth opening, mastication, swallowing, breathing, and decreased/lost working capacity or disability. Early diagnosis of intra-articular disorders can prevent from long-lasting functional complications caused by temporomandibular joint injuries. This study was performed for the purpose of early detection and investigation of organic pathological changes in the cartilaginous and osseous tissues of the temporomandibular joint caused by traumatic fractures of the mandibular condyle. Twenty patients underwent a general clinical examination, magnetic resonance imaging (MRI), and immune-enzyme testing for biochemical markers of connective tissue injury (pyridinoline and deoxypyridinoline) in urine. Disk dislocation, deformation, adhesion, perforation or squeeze, tension or disruption of ligaments, and injury of articular surfaces are among complications of mandibular fractures that can be revealed on MRI. As regards biochemical findings, we revealed a sharp rise in the levels of pyridinoline and deoxypyridinoline before treatment and a lack of stabilization within 21 days of treatment.

An inverse finite-element model of heel-pad indentation.

PubMed

Erdemir, Ahmet; Viveiros, Meredith L; Ulbrecht, Jan S; Cavanagh, Peter R

2006-01-01

A numerical-experimental approach has been developed to characterize heel-pad deformation at the material level. Left and right heels of 20 diabetic subjects and 20 nondiabetic subjects matched for age, gender and body mass index were indented using force-controlled ultrasound. Initial tissue thickness and deformation were measured using M-mode ultrasound; indentation forces were recorded simultaneously. An inverse finite-element analysis of the indentation protocol using axisymmetric models adjusted to reflect individual heel thickness was used to extract nonlinear material properties describing the hyperelastic behavior of each heel. Student's t-tests revealed that heel pads of diabetic subjects were not significantly different in initial thickness nor were they stiffer than those from nondiabetic subjects. Another heel-pad model with anatomically realistic surface representations of the calcaneus and soft tissue was developed to estimate peak pressure prediction errors when average rather than individualized material properties were used. Root-mean-square errors of up to 7% were calculated, indicating the importance of subject-specific modeling of the nonlinear elastic behavior of the heel pad. Indentation systems combined with the presented numerical approach can provide this information for further analysis of patient-specific foot pathologies and therapeutic footwear designs.

Space Radiation and Risks to Human Health

NASA Technical Reports Server (NTRS)

Huff, Janice L.

2014-01-01

The radiation environment in space poses significant challenges to human health and is a major concern for long duration manned space missions. Outside the Earth's protective magnetosphere, astronauts are exposed to higher levels of galactic cosmic rays, whose physical characteristics are distinct from terrestrial sources of radiation such as x-rays and gamma-rays. Galactic cosmic rays consist of high energy and high mass nuclei as well as high energy protons; they impart unique biological damage as they traverse through tissue with impacts on human health that are largely unknown. The major health issues of concern are the risks of radiation carcinogenesis, acute and late decrements to the central nervous system, degenerative tissue effects such as cardiovascular disease, as well as possible acute radiation syndromes due to an unshielded exposure to a large solar particle event. The NASA Human Research Program's Space Radiation Program Element is focused on characterization and mitigation of these space radiation health risks along with understanding these risks in context of the other biological stressors found in the space environment. In this overview, we will provide a description of these health risks and the Element's research strategies to understand and mitigate these risks.

Dynamic finite element analysis and moving particle simulation of human enamel on a microscale.

PubMed

Yamaguchi, Satoshi; Coelho, Paulo G; Thompson, Van P; Tovar, Nick; Yamauchi, Junpei; Imazato, Satoshi

2014-12-01

The study of biomechanics of deformation and fracture of hard biological tissues involving organic matrix remains a challenge as variations in mechanical properties and fracture mode may have time-dependency. Finite element analysis (FEA) has been widely used but the shortcomings of FEA such as the long computation time owing to re-meshing in simulating fracture mechanics have warranted the development of alternative computational methods with higher throughput. The aim of this study was to compare dynamic two-dimensional FEA and moving particle simulation (MPS) when assuming a plane strain condition in the modeling of human enamel on a reduced scale. Two-dimensional models with the same geometry were developed for MPS and FEA and tested in tension generated with a single step of displacement. The displacement, velocity, pressure, and stress levels were compared and Spearman׳s rank-correlation coefficients R were calculated (p<0.001). The MPS and FEA were significantly correlated for displacement, velocity, pressure, and Y-stress. The MPS may be further developed as an alternative approach without mesh generation to simulate deformation and fracture phenomena of dental and potentially other hard tissues with complex microstructure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Muscle-driven finite element simulation of human foot movements.

PubMed

Spyrou, L A; Aravas, N

2012-01-01

This paper describes a finite element scheme for realistic muscle-driven simulation of human foot movements. The scheme is used to simulate human ankle plantar flexion. A three-dimensional anatomically detailed finite element model of human foot and lower leg is developed and the idea of generating natural foot movement based entirely on the contraction of the plantar flexor muscles is used. The bones, ligaments, articular cartilage, muscles, tendons, as well as the rest soft tissues of human foot and lower leg are included in the model. A realistic three-dimensional continuum constitutive model that describes the biomechanical behaviour of muscles and tendons is used. Both the active and passive properties of muscle tissue are accounted for. The materials for bones and ligaments are considered as homogeneous, isotropic and linearly elastic, whereas the articular cartilage and the rest soft tissues (mainly fat) are defined as hyperelastic materials. The model is used to estimate muscle tissue deformations as well as stresses and strains that develop in the lower leg muscles during plantar flexion of the ankle. Stresses and strains that develop in Achilles tendon during such a movement are also investigated.

The muscular force transmission system: role of the intramuscular connective tissue.

PubMed

Turrina, Andrea; Martínez-González, Miguel Antonio; Stecco, Carla

2013-01-01

The objective of this review is to analyze in detail the microscopic structure and relations among muscular fibers, endomysium, perimysium, epimysium and deep fasciae. In particular, the multilayer organization and the collagen fiber orientation of these elements are reported. The endomysium, perimysium, epimysium and deep fasciae have not just a role of containment, limiting the expansion of the muscle with the disposition in concentric layers of the collagen tissue, but are fundamental elements for the transmission of muscular force, each one with a specific role. From this review it appears that the muscular fibers should not be studied as isolated elements, but as a complex inseparable from their fibrous components. The force expressed by a muscle depends not only on its anatomical structure, but also the angle at which its fibers are attached to the intramuscular connective tissue and the relation with the epimysium and deep fasciae. Copyright © 2012 Elsevier Ltd. All rights reserved.

Retention of elements absorbed by juvenile fish (Menidia menidia, Menidia Beryllina) from zooplankton prey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinfelder, J.R.; Fisher, N.S.

1994-12-01

Radiolabeled copepods (Acartia spp.) were fed to juvenile silversides (Menidia menidia and Menidia beryllina) to study element absorption in the fish. Copepods were reared from nauplii in the presence of different radiotracers ({sup 14}C,{sup 109}Cd,{sup 57}Co,{sup 32}P,{sup 35}S,{sup 75}Se, o;r {sup 65}Zn) and were analyzed for relative concentrations of these elements in their tissue fractions. Copepod exoskeletons contained nearly all of the trace metals (>97%), 60% of the Se, and less than half of the C,P, and S accumulated by the copepods. Within the nonexoskeleton tissues of the copepods, nonpolar (CHCl{sub 3} extractable) material contained 34 and 24% of themore » total C and P, but only 8 and 2% of the total S and Se. Absorption efficiencies of trace metals in juvenile silversides (2.7% for Cd, 2.1% for Co, 6.2% for Zn) were an order of magnitude lower than those for nonmetals (29% for Se, 50% for S and C, 60% for P). The absorption efficiencies in the juvenile silversides of all seven elements studied were directly related to the percent of each element in the nonexoskeleton fractions of the copepod prey, indicating that the fish absorbed the soft tissues of the copepods and egested the chitinous exoskeleton and its associated elements. 32 refs., 1 fig., 2 tabs.« less

Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle's Mapping and Quantification in Organ Tissue

PubMed Central

Sancey, Lucie; Motto-Ros, Vincent; Kotb, Shady; Wang, Xiaochun; Lux, François; Panczer, Gérard; Yu, Jin; Tillement, Olivier

2014-01-01

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) performed on thin sections of rodent tissues: kidneys and tumor, allows the detection of inorganic elements such as (i) Na, Ca, Cu, Mg, P, and Fe, naturally present in the body and (ii) Si and Gd, detected after the injection of gadolinium-based nanoparticles. The animals were euthanized 1 to 24 hr after intravenous injection of particles. A two-dimensional scan of the sample, performed using a motorized micrometric 3D-stage, allowed the infrared laser beam exploring the surface with a lateral resolution less than 100 μm. Quantitative chemical images of Gd element inside the organ were obtained with sub-mM sensitivity. LIBS offers a simple and robust method to study the distribution of inorganic materials without any specific labeling. Moreover, the compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of the same biological tissue with different types of response: elemental, molecular, or cellular. PMID:24962015

Identification of Regulatory Elements That Control PPARγ Expression in Adipocyte Progenitors

PubMed Central

Chou, Wen-Ling; Galmozzi, Andrea; Partida, David; Kwan, Kevin; Yeung, Hui; Su, Andrew I.; Saez, Enrique

2013-01-01

Adipose tissue renewal and obesity-driven expansion of fat cell number are dependent on proliferation and differentiation of adipose progenitors that reside in the vasculature that develops in coordination with adipose depots. The transcriptional events that regulate commitment of progenitors to the adipose lineage are poorly understood. Because expression of the nuclear receptor PPARγ defines the adipose lineage, isolation of elements that control PPARγ expression in adipose precursors may lead to discovery of transcriptional regulators of early adipocyte determination. Here, we describe the identification and validation in transgenic mice of 5 highly conserved non-coding sequences from the PPARγ locus that can drive expression of a reporter gene in a manner that recapitulates the tissue-specific pattern of PPARγ expression. Surprisingly, these 5 elements appear to control PPARγ expression in adipocyte precursors that are associated with the vasculature of adipose depots, but not in mature adipocytes. Characterization of these five PPARγ regulatory sequences may enable isolation of the transcription factors that bind these cis elements and provide insight into the molecular regulation of adipose tissue expansion in normal and pathological states. PMID:24009687

Tissue Trace Elements and Lipid Peroxidation in Breeding Female Bank Voles Myodes glareolus.

PubMed

Bonda-Ostaszewska, Elżbieta; Włostowski, Tadeusz; Łaszkiewicz-Tiszczenko, Barbara

2018-04-27

Recent studies have demonstrated that reproduction reduces oxidative damage in various tissues of small mammal females. The present work was designed to determine whether the reduction of oxidative stress in reproductive bank vole females was associated with changes in tissue trace elements (iron, copper, zinc) that play an essential role in the production of reactive oxygen species. Lipid peroxidation (a marker of oxidative stress) and iron concentration in liver, kidneys, and skeletal muscles of reproducing bank vole females that weaned one litter were significantly lower than in non-reproducing females; linear regression analysis confirmed a positive relation between the tissue iron and lipid peroxidation. The concentrations of copper were significantly lower only in skeletal muscles of reproductive females and correlated positively with lipid peroxidation. No changes in tissue zinc were found in breeding females when compared with non-breeding animals. These data indicate that decreases in tissue iron and copper concentrations may be responsible for the reduction of oxidative stress in reproductive bank vole females.

Stromal cell-based immunotherapy in transplantation.

PubMed

Charles, Ronald; Lu, Lina; Qian, Shiguang; Fung, John J

2011-12-01

Organs are composed of parenchymal cells that characterize organ function and nonparenchymal cells that are composed of cells in transit, as well as tissue connective tissue, also referred to as tissue stromal cells. It was originally thought that these tissue stromal cells provided only structural and functional support for parenchymal cells and were relatively inert. However, we have come to realize that tissue stromal cells, not restricted to in the thymus and lymphoid organs, also play an active role in modulating the immune system and its response to antigens. The recognition of these elements and the elucidation of their mechanisms of action have provided valuable insight into peripheral immune regulation. Extrapolation of these principles may allow us to utilize their potential for clinical application. In this article, we will summarize a number of tissue stromal elements/cell types that have been shown to induce hyporesponsiveness to transplants. We will also discuss the mechanisms by which these stromal cells create a tolerogenic environment, which in turn results in long-term allograft survival.

Trace elements and organic compounds in sediment and fish tissue from the Great Salt Lake basins, Utah, Idaho, and Wyoming, 1998-99

USGS Publications Warehouse

Waddell, Kidd M.; Giddings, Elise M.

2004-01-01

A study to determine the occurrence and distribution of trace elements, organochlorine pesticides, polychlorinated biphenyls (PCBs), and semivolatile organic compounds in sediment and in fish tissue was conducted in the Great Salt Lake Basins study unit of the National Water-Quality Assessment (NAWQA) program during 1998-99. Streambed-sediment and fish-tissue samples were collected concurrently at 11 sites and analyzed for trace-element concentration. An additional four sites were sampled for streambed sediment only and one site for fish tissue only. Organic compounds were analyzed from streambed-sediment and fish-tissue samples at 15 sites concurrently.Bed-sediment cores from lakes, reservoirs, and Farmington Bay collected by the NAWQA program in 1998 and by other researchers in 1982 were used to examine historical trends in trace-element concentration and to determine anthropogenic sources of contaminants. Cores collected in 1982 from Mirror Lake, a high-mountain reference location, showed an enrichment of arsenic, cadmium, copper, lead, tin, and zinc in the surface sediments relative to the deeper sediments, indicating that enrichment likely began after about 1900. This enrichment was attributed to atmospheric deposition during the period of metal-ore mining and smelting. A core from Echo Reservoir, in the Weber River Basin, however, showed a different pattern of trace-element concentration that was attributed to a local source. This site is located downstream from the Park City mining district, which is the most likely historical source of trace elements. Cores collected in 1998 from Farmington Bay show that the concentration of lead began to increase after 1842 and peaked during the mid-1980s and has been in decline since. Recent sediments deposited during 1996-98 indicate a 41- to 62-percent reduction since the peak in the mid-1980s.The concentration of trace elements in streambed sediment was greatest at sites that have been affected by historic mining, including sites on Little Cottonwood Creek in the Jordan River basin, Silver Creek in the Weber River basin, and the Weber River below the confluence with Silver Creek. There was significant correlation of lead concentrations in streambed sediment and fish tissue, but other trace elements did not correlate well. Streambed sediment and fish tissue collected from sites in the Bear River basin, which is predominantly rangeland and agriculture, generally had low concentrations of most elements.Sediment-quality guidelines were used to assess the relative toxicity of streambed-sediment sites to aquatic communities. Sites affected by mining exceeded the Probable Effect Concentration (PEC), the concentration at which it is likely there will be a negative effect on the aquatic community, for arsenic, cadmium, copper, lead, silver, mercury, and zinc. Sites that were not affected by mining did not exceed these criteria. Concentrations of trace elements in samples collected from the Great Salt Lake Basins study unit (GRSL) are high compared to those of samples collected nationally with the NAWQA program. Nine of 15 streambed-sediment samples and 11 of 14 fish-tissue samples had concentrations of at least one trace element greater than the concentration of 90 percent of the samples collected nationally during 1993-2000.Organic compounds that were examined in streambed sediment and fish-tissue samples also were examined in bed-sediment cores. A bed-sediment core from Farmington Bay of Great Salt Lake showed an increase in total polycyclic aromatic hydrocarbon (PAH) concentrations coincident with the increase in population in Salt Lake Valley, which drains into this bay. Analysis of streambed-sediment samples showed that the highest concentrations of PAHs were detected at urban sites, including two sites in the lower Jordan River (the Jordan River flows into Farmington Bay), the Weber River at Ogden Bay, and the Provo River near Provo. Other organic compounds detected in streambed sediment in the lower Jordan River were PCBs, DDT compounds, and chlordane compounds.Organic compounds were detected more frequently in fish tissue than in streambed sediment. Chlordane compounds and PCBs were detected more frequently at urban sites. DDT compounds were detected at 13 of 15 sites including urban and agricultural sites. Concentrations of total DDT in fish tissue exceeded the guideline for protection of fish-eating wildlife at two urban sites. The concentration of organic compounds in the GRSL study unit is low compared with that of samples collected nationally.

Concentrations of mercury and other trace elements in walleye, smallmouth bass, and rainbow trout in Franklin D. Roosevelt Lake and the upper Columbia River, Washington, 1994

USGS Publications Warehouse

Munn, M.D.; Cox, S.E.; Dean, C.J.

1995-01-01

Three species of sportfish--walleye, smallmouth bass, and rainbow trout--were collected from Franklin D. Roosevelt Lake and the upstream reach of the Columbia River within the state of Washington, to determine the concentrations of mercury and other selected trace elements in fish tissue. Concentrations of total mercury in walleye fillets ranged from 0.11 to 0.44 milligram per kilogram, with the higher concentrations in the larger fish. Fillets of smallmouth bass and rainbow trout also contained mercury, but generally at lower concentrations. Other selected trace elements were found in fillet samples, but the concentrations were generally low depending on species and the specific trace element. The trace elements cadmium, copper, lead, and zinc were found in liver tissue of these same species with zinc consistently present in the highest concentration.

Multi-elemental imaging of paraffin-embedded human samples by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Moncayo, S.; Trichard, F.; Busser, B.; Sabatier-Vincent, M.; Pelascini, F.; Pinel, N.; Templier, I.; Charles, J.; Sancey, L.; Motto-Ros, V.

2017-07-01

Chemical elements play central roles for physiological homeostasis in human cells, and their dysregulation might lead to a certain number of pathologies. Novel imaging techniques that improve the work of pathologists for tissue analysis and diagnostics are continuously sought. We report the use of Laser-Induced Breakdown Spectroscopy (LIBS) to perform multi-elemental images of human paraffin-embedded skin samples on the entire biopsy scale in a complementary and compatible way with microscope histopathological examination. A specific instrumental configuration is proposed in order to detect most of the elements of medical interest (i.e. P, Al, Mg, Na, Zn, Si, Fe, and Cu). As an example of medical application, we selected and analysed skin biopsies, including healthy skin tissue, cutaneous metastasis of melanoma, Merkel-cell carcinoma and squamous cell carcinoma. Clear distinctions in the distribution of chemical elements are observed from the different samples investigated. This study demonstrates the high complementarity of LIBS elemental imaging with conventional histopathology, opening new opportunities for any medical application involving metals.

Autologous platelet-rich plasma as an adipocyte in vivo delivery system: case report.

PubMed

Azzena, Bruno; Mazzoleni, Francesco; Abatangelo, Giovanni; Zavan, Barbara; Vindigni, Vincenzo

2008-01-01

Tissue engineering has emerged as a promising alternative to current clinical treatments for restoration of soft tissue defects. A key element in the process of tissue engineering is an ideal implant that provides structural support and a favorable environment for growing cells. The authors hypothesized that autologous platelet-rich plasma (APRP) could be used as an in vivo adipocyte delivery system to favor cell survival and to stimulate early recruitment of microcapillaries to the site of implantation. Autologous fat was included in APRP and injected as a gel into a subcutaneous pocket created to correct a painful, adherent scar at the shoulder level in a 75-year-old woman. The surgical outcome was evaluated by histologic and immunohistochemical analysis as well as by ecography before and after surgery. The results were satisfactory, showing fat survival 1 year after surgery. The characteristics of this new material should stimulate research into future clinical applications for such cell constructs in plastic and reconstructive surgery.

Contaminants in sea ducks: metals, trace elements, petroleum, organic pollutants, and radiation: Chapter 6

USGS Publications Warehouse

Franson, J. Christian

2015-01-01

Exposure to lead and petroleum has caused deaths of sea ducks, but relatively few contaminants have been shown to cause mortality or be associated with population level effects. This chapter focuses primarily on field reports of contaminant concentrations in tissues of sea ducks in North America and Europe and results of some pertinent experimental studies. Much of the available interpretive data for contaminants in waterfowl come from studies of freshwater species. Limits of available data present a challenge for managers interested in sea ducks because field reports  have shown that marine birds may carry greater burdens of some pollutants than freshwater species, particularly metals. It is important, then, to distinguish poisoning due to a particular contaminant as a cause of death in sea ducks versus simple exposure based solely on tissue residues. A comprehensive approach that incorporates information on field circumstances, any observed clinical signs and lesions, and tissues residues is recommended when evaluating contaminant concentrations in sea ducks.

[Fluorides in the human bones – selected issues].

PubMed

Palczewska-Komsa, Mirona; Kalisińska, Elżbieta; Stogiera, Anna; Szmidt, Monika

Long -term intake of luoride leads to skeletal luorosis. The toxicity of luoride, not only for the human body, but also the entire ecosystem makes it necessary to constantly monitor their content in the environment. Accordingly, there is a need to control the level of luorides (F⁻) in humans, particularly in bone tissue, which relects long -term accumulation of these compounds. The aim of the study was to determine the concentration of luoride in the human bones depending on biological factors and environmental conditions on the basis of the published literature. Given the importance of bone tissue as the main reservoir of luoride ions is an important issue to continue to monitor the concentration of F⁻ in this tissue, particularly for people living in the polluted environment luorine compounds. There are numerous works on concentrations of this element in human bones in world literature which proves the great interest in the subject. It should be underlined the need for further study of this issue for people living in different regions of Poland.

3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP.

PubMed

Viana, R S; Agasthya, G A; Yoriyaz, H; Kapadia, A J

2013-09-07

This work describes a simulation study investigating the application of neutron stimulated emission computed tomography (NSECT) for noninvasive 3D imaging of renal cancer in vivo. Using MCNP5 simulations, we describe a method of diagnosing renal cancer in the body by mapping the 3D distribution of elements present in tumors using the NSECT technique. A human phantom containing the kidneys and other major organs was modeled in MCNP5. The element composition of each organ was based on values reported in literature. The two kidneys were modeled to contain elements reported in renal cell carcinoma (RCC) and healthy kidney tissue. Simulated NSECT scans were executed to determine the 3D element distribution of the phantom body. Elements specific to RCC and healthy kidney tissue were then analyzed to identify the locations of the diseased and healthy kidneys and generate tomographic images of the tumor. The extent of the RCC lesion inside the kidney was determined using 3D volume rendering. A similar procedure was used to generate images of each individual organ in the body. Six isotopes were studied in this work - (32)S, (12)C, (23)Na, (14)N, (31)P and (39)K. The results demonstrated that through a single NSECT scan performed in vivo, it is possible to identify the location of the kidneys and other organs within the body, determine the extent of the tumor within the organ, and to quantify the differences between cancer and healthy tissue-related isotopes with p ≤ 0.05. All of the images demonstrated appropriate concentration changes between the organs, with some discrepancy observed in (31)P, (39)K and (23)Na. The discrepancies were likely due to the low concentration of the elements in the tissue that were below the current detection sensitivity of the NSECT technique.

Enhanced focus steering abilities of multi-element therapeutic arrays operating in nonlinear regimes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuldashev, P., E-mail: petr@acs366.phys.msu.ru; Ilyin, S.; Gavrilov, L.

2015-10-28

Steering abilities of a typical HIFU therapeutic array operated in linear and nonlinear regimes were compared using numerical simulation with the 3D Westervelt equation. The array included 256 elements of 1.2 MHz frequency and 6.6 mm diameter distributed in a quasi-random pattern over a spherical shell with a 130 mm aperture and a focal length of 120 mm. In the case of linear focusing, thermal effects are proportional to the intensity level and the criterion for safe array operation is that the intensity in the grating lobes should be less than 10% of the intensity in the main focus. Inmore » the case of nonlinear focusing, the heating effect is no longer proportional to intensity; therefore the heat deposition rate was chosen as the relevant metric, using the same 10% threshold for the secondary lobe in comparison with the focal maximum. When steering the focus, the same linearly predicted intensity level at the main focus was maintained by increasing the array power. Numerical simulations of the acoustic field were performed for nonlinear propagation both in water and in tissue. It was shown that for shock-forming conditions in the main focus, the steering range of safe electronic focusing is larger than that for linear propagation conditions. Nonlinear sonication regimes therefore can be used to enlarge tissue volumes that can be sonicated using electronic steering of the focus of HIFU arrays.« less

Iron and oxygen sensing: a tale of 2 interacting elements?

PubMed

Simpson, Robert J; McKie, Andrew T

2015-02-01

Iron and oxygen metabolism are intimately linked with one another. A change in the level of either metabolite results in activation of common pathways. At the heart of these responses lies a group of iron and oxygen dependent enzymes called prolyl hydroxylases. Prolyl hydroxylases (PHDs) require both iron and oxygen for optimal activity and their biological activity is to carry out the critical post-translational modification of the addition of a hydroxyl group to specific proline residues within Hypoxia Inducible Factor (HIFs)-well known transcription factors originally thought to regulate responses to hypoxia but which are now known to regulate key iron metabolism proteins too. The addition of the hydroxyl group ultimately leads to the unbiquitylation and destruction of HIFs, thus PHDs control appropriate HIF transcriptional responses depending on cellular oxygen or iron levels. There are two major HIFs; HIF1α and HIF2α. In terms of responses to iron HIF2α is of major importance in key tissues such as the intestine where several iron transporters (Ferroportin, Dcytb) contain HREs within their promoters which bind HIF2α. Furthermore the recent discovery that HIF2α contains a 5' iron responsive element (IRE) has underlined the importance of HIF2α as a major player in iron metabolism. This review brings together recent findings with regard to the HIF2α/IRP network as well as other aspects of iron sensing in cells and tissues.

Development and Validation of a Statistical Shape Modeling-Based Finite Element Model of the Cervical Spine Under Low-Level Multiple Direction Loading Conditions

PubMed Central

Bredbenner, Todd L.; Eliason, Travis D.; Francis, W. Loren; McFarland, John M.; Merkle, Andrew C.; Nicolella, Daniel P.

2014-01-01

Cervical spinal injuries are a significant concern in all trauma injuries. Recent military conflicts have demonstrated the substantial risk of spinal injury for the modern warfighter. Finite element models used to investigate injury mechanisms often fail to examine the effects of variation in geometry or material properties on mechanical behavior. The goals of this study were to model geometric variation for a set of cervical spines, to extend this model to a parametric finite element model, and, as a first step, to validate the parametric model against experimental data for low-loading conditions. Individual finite element models were created using cervical spine (C3–T1) computed tomography data for five male cadavers. Statistical shape modeling (SSM) was used to generate a parametric finite element model incorporating variability of spine geometry, and soft-tissue material property variation was also included. The probabilistic loading response of the parametric model was determined under flexion-extension, axial rotation, and lateral bending and validated by comparison to experimental data. Based on qualitative and quantitative comparison of the experimental loading response and model simulations, we suggest that the model performs adequately under relatively low-level loading conditions in multiple loading directions. In conclusion, SSM methods coupled with finite element analyses within a probabilistic framework, along with the ability to statistically validate the overall model performance, provide innovative and important steps toward describing the differences in vertebral morphology, spinal curvature, and variation in material properties. We suggest that these methods, with additional investigation and validation under injurious loading conditions, will lead to understanding and mitigating the risks of injury in the spine and other musculoskeletal structures. PMID:25506051

Fluid-Structure Analysis of Opening Phenomena in a Collapsible Airway

NASA Astrophysics Data System (ADS)

Ghadiali, Samir N.; Banks, Julie; Swarts, J. Douglas

2003-11-01

Several physiological functions require the opening of collapsed respiratory airways. For example, the Eustachian tube (ET), which connects the nasopharynx with the middle ear (ME), must be periodically opened to maintain ambient ME pressures. These openings normally occur during swallowing when muscle contraction deforms the surrounding soft tissue. The inability to open the ET results in the most common and costly ear disease in children, Otitis Media. Although tissue-based treatments have been purposed, the influence of the various tissue mechanical properties on flow phenomena has not been investigated. A computational model of ET opening was developed using in-vivo structural data to investigate these fluid-structure interactions. This model accounts for both tissue deformation and the resulting airflow in a non-circular conduit. Results indicate that ET opening is more sensitive to the applied muscle forces than elastic tissue properties. These models have therefore identified how different tissue elements alter ET opening phenomena, which elements should be targeted for treatment and the optimal mechanical properties of these tissue constructs. Research supported by NIH grant DC005345.

Chemical disposition of boron in animals and humans.

PubMed Central

Moseman, R F

1994-01-01

Elemental boron was isolated in 1808. It typically occurs in nature as borates hydrated with varying amounts of water. Important compounds are boric acid and borax. Boron compounds are also used in the production of metals, enamels, and glasses. In trace amounts, boron is essential for the growth of many plants, and is found in animal and human tissues at low concentrations. Poisoning in humans has been reported as the result of accidental ingestion or use of large amounts in the treatment of burns. Boron as boric acid is fairly rapidly absorbed and excreted from the body via urine. The half-life of boric acid in humans is on the order of 1 day. Boron does not appear to accumulate in soft tissues of animals, but does accumulate in bone. Normal levels of boron in soft tissues, urine, and blood generally range from less than 0.05 ppm to no more than 10 ppm. In poisoning incidents, the amount of boric acid in brain and liver tissue has been reported to be as high as 2000 ppm. Recent studies at the National Institute of Environmental Health Sciences have indicated that boron may contribute to reduced fertility in male rodents fed 9000 ppm of boric acid in feed. Within a few days, boron levels in blood and most soft tissues quickly reached a plateau of about 15 ppm. Boron in bone did not appear to plateau, reaching 47 ppm after 7 days on the diet. Cessation of exposure to dietary boron resulted in a rapid drop in bone boron.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7889870

Morphological and ultrastructural comparative analysis of bone tissue after Er:YAG laser and surgical drill osteotomy.

PubMed

Panduric, Dragana Gabric; Juric, Ivona Bago; Music, Svetozar; Molčanov, Krešimir; Sušic, Mato; Anic, Ivica

2014-07-01

The purpose of this study was to analyze morphological, chemical, and crystallographic changes of bone tissue after osteotomy performed with an erbium:yttrium-aluminium-garnet (Er:YAG) laser and a low speed pilot drill. Bone blocks were prepared from porcine ribs, and on each block, two tunnel preparations were performed using the Er:YAG laser (pulse energy: 1000 mJ, pulse duration: 300 μs, pulse repetition rate: 20 Hz) or the low-speed surgical pilot drill. The morphological changes of the cortical and the spongious surface of the tunnel preparations were analyzed under the field emission scanning electron microscopy (FE-SEM) at low and high resolution. The distribution and the level of chemical elements in the treated surfaces were evaluated by qualitative and semiquantitative energy dispersive x-ray analysis (SEM-EDX). Diffraction x-ray analysis was used to detect any differences and thermally induced modifications of hydroxyapatite crystals. FE-SEM revealed sharp edges of the Er:YAG preparations, with empty intertrabecular spaces and no signs of carbonization. In the drill group, the surface of the preparations was smooth, completely covered with smear layer and microcracks, and with hairy-like irregularities on the edges. SEM-EDX analysis did not reveal any differences in the number of specific chemical elements between the laser and the drill group. There were no thermally induced modifications of hydroxyapatite crystal structure in the bone tissue in either group. The Er:YAG laser ablation did not cause any chemical or crystallographic changes of the bone tissue. Compared with the drill, Er:YAG laser created well-defined edges of the preparations, and cortical bone had no smear layer.

SERPINE1: A Molecular Switch in the Proliferation-Migration Dichotomy in Wound-“Activated” Keratinocytes

PubMed Central

Simone, Tessa M.; Higgins, Craig E.; Czekay, Ralf-Peter; Law, Brian K.; Higgins, Stephen P.; Archambeault, Jaclyn; Kutz, Stacie M.; Higgins, Paul J.

2014-01-01

Significance: A highly interactive serine protease/plasmin/matrix metalloproteinase axis regulates stromal remodeling in the wound microenvironment. Current findings highlight the importance of stringent controls on protease expression and their topographic activities in cell proliferation, migration, and tissue homeostasis. Targeting elements in this cascading network may lead to novel therapeutic approaches for fibrotic diseases and chronic wounds. Recent Advances: Matrix-active proteases and their inhibitors orchestrate wound site tissue remodeling, cell migration, and proliferation. Indeed, the serine proteases urokinase plasminogen activator and tissue-type plasminogen activator (uPA/tPA) and their major phsyiological inhibitor, plasminogen activator inhibitor-1 (PAI-1; serine protease inhibitor clade E member 1 [SERPINE1]), are upregulated in several cell types during injury repair. Coordinate expression of proteolytic enzymes and their inhibitors in the wound bed provides a mechanism for fine control of focal proteolysis to facilitate matrix restructuring and cell motility in complex environments. Critical Issues: Cosmetic and tissue functional consequences of wound repair anomalies affect the quality of life of millions of patients in the United States alone. The development of novel therapeutics to manage individuals most affected by healing anomalies will likely derive from the identification of critical, translationally accessible, control elements in the wound site microenvironment. Future Directions: Activation of the PAI-1 gene early after wounding, its prominence in the repair transcriptome and varied functions suggest a key role in the global cutaneous injury response program. Targeting PAI-1 gene expression and/or PAI-1 function with molecular genetic constructs, neutralizing antibodies or small molecule inhibitors may provide a novel, therapeutically relevant approach, to manage the pathophysiology of wound healing disorders associated with deficient or excessive PAI-1 levels. PMID:24669362

Quantitative evaluation of potential irradiation geometries for carbon-ion beam grid therapy.

PubMed

Tsubouchi, Toshiro; Henry, Thomas; Ureba, Ana; Valdman, Alexander; Bassler, Niels; Siegbahn, Albert

2018-03-01

Radiotherapy using grids containing cm-wide beam elements has been carried out sporadically for more than a century. During the past two decades, preclinical research on radiotherapy with grids containing small beam elements, 25 μm-0.7 mm wide, has been performed. Grid therapy with larger beam elements is technically easier to implement, but the normal tissue tolerance to the treatment is decreasing. In this work, a new approach in grid therapy, based on irradiations with grids containing narrow carbon-ion beam elements was evaluated dosimetrically. The aim formulated for the suggested treatment was to obtain a uniform target dose combined with well-defined grids in the irradiated normal tissue. The gain, obtained by crossfiring the carbon-ion beam grids over a simulated target volume, was quantitatively evaluated. The dose distributions produced by narrow rectangular carbon-ion beams in a water phantom were simulated with the PHITS Monte Carlo code. The beam-element height was set to 2.0 cm in the simulations, while the widths varied from 0.5 to 10.0 mm. A spread-out Bragg peak (SOBP) was then created for each beam element in the grid, to cover the target volume with dose in the depth direction. The dose distributions produced by the beam-grid irradiations were thereafter constructed by adding the dose profiles simulated for single beam elements. The variation of the valley-to-peak dose ratio (VPDR) with depth in water was thereafter evaluated. The separation of the beam elements inside the grids were determined for different irradiation geometries with a selection criterion. The simulated carbon-ion beams remained narrow down to the depths of the Bragg peaks. With the formulated selection criterion, a beam-element separation which was close to the beam-element width was found optimal for grids containing 3.0-mm-wide beam elements, while a separation which was considerably larger than the beam-element width was found advantageous for grids containing 0.5-mm-wide beam elements. With the single-grid irradiation setup, the VPDRs were close to 1.0 already at a distance of several cm from the target. The valley doses given to the normal tissue at 0.5 cm distance from the target volume could be limited to less than 10% of the mean target dose if a crossfiring setup with four interlaced grids was used. The dose distributions produced by grids containing 0.5- and 3.0-mm wide beam elements had characteristics which could be useful for grid therapy. Grids containing mm-wide carbon-ion beam elements could be advantageous due to the technical ease with which these beams can be produced and delivered, despite the reduced threshold doses observed for early and late responding normal tissue for beams of millimeter width, compared to submillimetric beams. The treatment simulations showed that nearly homogeneous dose distributions could be created inside the target volumes, combined with low valley doses in the normal tissue located close to the target volume, if the carbon-ion beam grids were crossfired in an interlaced manner with optimally selected beam-element separations. The formulated selection criterion was found useful for the quantitative evaluation of the dose distributions produced by the different irradiation setups. © 2018 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Emergence of Scaffold-free Approaches for Tissue Engineering Musculoskeletal Cartilages

PubMed Central

DuRaine, Grayson D.; Brown, Wendy E.; Hu, Jerry C.; Athanasiou, Kyriacos A.

2014-01-01

This review explores scaffold-free methods as an additional paradigm for tissue engineering. Musculoskeletal cartilages –for example articular cartilage, meniscus, temporomandibular joint disc, and intervertebral disc – are characterized by low vascularity and cellularity, and are amenable to scaffold-free tissue engineering approaches. Scaffold-free approaches, particularly the self-assembling process, mimic elements of developmental processes underlying these tissues. Discussed are various scaffold-free approaches for musculoskeletal cartilage tissue engineering, such as cell sheet engineering, aggregation, and the self-assembling process, as well as the availability and variety of cells used. Immunological considerations are of particular importance as engineered tissues are frequently of allogeneic, if not xenogeneic, origin. Factors that enhance the matrix production and mechanical properties of these engineered cartilages are also reviewed, as the fabrication of biomimetically suitable tissues is necessary to replicate function and ensure graft survival in vivo. The concept of combining scaffold-free and scaffold-based tissue engineering methods to address clinical needs is also discussed. Inasmuch as scaffold-based musculoskeletal tissue engineering approaches have been employed as a paradigm to generate engineered cartilages with appropriate functional properties, scaffold-free approaches are emerging as promising elements of a translational pathway not only for musculoskeletal cartilages but for other tissues as well. PMID:25331099

Residues of lead, cadmium, and arsenic in livers of Mexican free-tailed bats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thies, M.; Gregory, D.

Since 1936, the size of the summer population of Mexican free-tailed bats, Tadarida brasiliensisat Carlsbad Caverns, New Mexico, declined from an estimated 8.7 million to 700,000 in 1991. This decline has been attributed primarily to human disturbance and the heavy agricultural use of organochlorine pesticides. Members of this species forage extensively over heavily agricultural areas, feeding on insects potentially contaminated with high levels of insecticides and trace metals. However, contamination from elements such as lead, cadmium, and arsenic have not been examined. The accumulation of these elements in wild vertebrates is often a primary reflection of contamination of the foodmore » supply. The presence of elemental contaminants in body tissues of bats is poorly documented. The objectives of this study were to examine and compare lead, cadmium, and arsenic contamination in livers of adult T. Brasiliensis from Carlsbad Caverns and Vickery Cave, a maternity colony in northwestern Oklahoma. Lead, cadmium, and arsenic were specifically selected because of their documented toxic and/or reproductive effects and their potential availability to this species. Large quantities of tetraethyl lead have been released into the environment and other lead compounds continue to be released by industrial manufacturing and petroleum refinement processes. Cadmium is used in a number of industrial processes such as metal plating and fabrication of alloys and is released from phosphate fertilizers and combusted coals. Teratogenicity appears to be greater for cadmium than for other elements. Arsenical compounds have been commonly used as herbicides and defoliants. These compounds have been demonstrated to cause abnormal embryonic development, degenerative tissue changes, cancer, chromosomal damage, and death in domestic animals.« less

Trace elements and organic chemicals in stream-bottom sediments and fish tissues, Red River of the North basin, Minnesota, North Dakota, and South Dakota, 1992-95

USGS Publications Warehouse

Brigham, M.E.; Goldstein, R.M.; Tornes, L.H.

1998-01-01

Stream-bottom sediment and fish-tissue samples from the Red River of the North Basin, were analyzed for a large suite of chemical elements and organic chemicals. Cadmium, lead, and mercury were widespread in sediments, at concentrations not indicative of acute contamination. Mercury, the element of greatest health concern in the region, was detected at low concentrations in 38 of 43 sediment samples (<0.02-0.13 micrograms per gram) and all of eleven fish-liver samples (0.03-0.6 micrograms per gram dry weight, or 0.0066-0.13 micrograms per gram wet weight). Concentrations of many elements appeared to be controlled by mineral rather than anthropogenic sources. DDT and its metabolites were the most frequently detected synthetic organochlorines: p,p'-DDE was detected in 9 of 38 sediment samples (concentration range: <1-16 nanograms per gram) and also frequently in whole-fish samples. Total DDT (the sum of DDT and its metabolites) concentrations ranged from <5 to 217 nanograms per gram, and at least one component of total DDT was detected in 19 of 23 fish samples. Concentrations of DDT and its metabolites in stream sediments were significantly higher in the intensively cropped Red River Valley Lake Plain, compared to upland areas, probably because of greater historical DDT usage in the lake plain. Several polycyclic aromatic hydrocarbons were detected in stream-bottom sediments. Although the potentially toxic chemicals measured in this study were at low levels, relative to more contaminated areas of the Nation, maximum concentrations of some chemicals are of concern because of their possible effects on aquatic biota and human health.

Subject-Specific Finite Element Analysis of the Carpal Tunnel Cross-Sectional to Examine Tunnel Area Changes in Response to Carpal Arch Loading

PubMed Central

Walia, Piyush; Erdemir, Ahmet; Li, Zong-Ming

2017-01-01

Background Manipulating the carpal arch width (i.e. distance between hamate and trapezium bones) has been suggested as a means to increase carpal tunnel cross-sectional area and alleviate median nerve compression. The purpose of this study was to develop a finite element model of the carpal tunnel and to determine an optimal force direction to maximize area. Methods A planar geometric model of carpal bones at hamate level was reconstructed from MRI with inter-carpal joint spaces filled with a linear elastic surrogate tissue. Experimental data with discrete carpal tunnel pressures (50, 100, 150, and 200 mmHg) and corresponding carpal bone movements were used to obtain material property of surrogate tissue by inverse finite element analysis. The resulting model was used to simulate changes of carpal arch widths and areas with directional variations of a unit force applied at the hook of hamate. Findings Inverse finite element model predicted the experimental area data within 1.5% error. Simulation of force applications showed that carpal arch width and area were dependent on the direction of force application, and minimal arch width and maximal area occurred at 138° (i.e. volar-radial direction) with respect to the hamate-to-trapezium axis. At this force direction, the width changed to 24.4 mm from its initial 25.1 mm (3% decrease), and the area changed to 301.6 mm2 from 290.3 mm2 (4% increase). Interpretation The findings of the current study guide biomechanical manipulation to gain tunnel area increase, potentially helping reduce carpal tunnel pressure and relieve symptoms of compression median neuropathy. PMID:28073093