Intake of dietary salt and drinking water: Implications for the development of age-related macular degeneration.

PubMed

Bringmann, Andreas; Hollborn, Margrit; Kohen, Leon; Wiedemann, Peter

2016-01-01

Systemic hypertension is a risk factor of age-related retinal diseases such as diabetic retinopathy and age-related macular degeneration. High intake of dietary salt and low intake of water increase extracellular osmolality resulting in hypertension, in particular in salt-sensitive individuals. This review summarizes the present knowledge regarding the impact of salt and water intake on the regulation of blood pressure, retinal function, and the development of age-related retinal diseases. A literature search of the Medline database and a summary of recent studies that used human RPE cells. The salt sensitivity of the blood pressure and plasma osmolality increase with age, and body water deficits are common in older individuals. High plasma osmolality has adverse effects in the retina. In RPE cells, high osmolality induces expression and secretion of angiogenic factors, such as vascular endothelial growth factor (VEGF), placental growth factor, and basic fibroblast growth factor, and expression of aquaporin-5, a water channel implicated in transepithelial water transport. The transcriptional activities of hypoxia-inducible factor-1 (HIF-1) and nuclear factor of activated T cell 5 (NFAT5) are critical for the production of VEGF in response to salt-induced osmotic stress. Salt-induced osmotic stress also induces priming of the NLRP3 inflammasome and activates inflammatory enzymes in RPE cells. Raised plasma osmolality may aggravate age-related retinal diseases by stimulation of local inflammation and angiogenic factor production in the RPE. Alterations in salt and water consumption, and of minerals that stimulate renal salt excretion, may offer nutritional approaches to prevent age-related retinal disorders, in particular in salt-sensitive individuals and individuals who show signs of body dehydration.

Age Decline in the Activity of the Ca2+-sensitive K+ Channel of Human Red Blood Cells

PubMed Central

Tiffert, Teresa; Daw, Nuala; Etzion, Zipora; Bookchin, Robert M.; Lew, Virgilio L.

2007-01-01

The Ca2+-sensitive K+ channel of human red blood cells (RBCs) (Gardos channel, hIK1, hSK4) was implicated in the progressive densification of RBCs during normal senescence and in the mechanism of sickle cell dehydration. Saturating RBC Ca2+ loads were shown before to induce rapid and homogeneous dehydration, suggesting that Gardos channel capacity was uniform among the RBCs, regardless of age. Using glycated hemoglobin as a reliable RBC age marker, we investigated the age–activity relation of Gardos channels by measuring the mean age of RBC subpopulations exceeding a set high density boundary during dehydration. When K+ permeabilization was induced with valinomycin, the oldest and densest cells, which started nearest to the set density boundary, crossed it first, reflecting conservation of the normal age–density distribution pattern during dehydration. However, when Ca2+ loads were used to induce maximal K+ fluxes via Gardos channels in all RBCs (F max), the youngest RBCs passed the boundary first, ahead of the older RBCs, indicating that Gardos channel F max was highest in those young RBCs, and that the previously observed appearance of uniform dehydration concealed a substantial degree of age scrambling during the dehydration process. Further analysis of the Gardos channel age–activity relation revealed a monotonic decline in F max with cell age, with a broad quasi-Gaussian F max distribution among the RBCs. PMID:17470662

Plasma serpinB1 is related to insulin sensitivity but not pancreatic β-Cell function in non-diabetic adults.

PubMed

Glicksman, Michael; Asthana, Asha; Abel, Brent S; Walter, Mary F; Skarulis, Monica C; Muniyappa, Ranganath

2017-03-01

Pancreatic β -cell dysfunction because of reduced β -cell mass and function is a primary determinant in the progression of diabetes. Increase in β -cell mass and compensatory hyperinsulinaemia is frequently associated with insulin-resistant states. Although the humoral factors mediating this compensatory response are unknown, serpinB1, a protease inhibitor, has recently been proposed to be one such factor. In this study, we examine the relationships between plasma serpinB1, insulin sensitivity, and pancreatic β -cell function in non-diabetic individuals. 117 subjects (women, n  = 50, men, n  = 67; age= 37.6 ± 10.8; BMI=31.1 ± 7.7 kg/m 2 ) underwent an insulin-modified frequently sampled intravenous glucose tolerance test (FSIVGTT) at the NIH Clinical Research Center. Acute insulin response (AIR) and insulin sensitivity index (SI) were obtained from the FSIVGTT with MINMOD analysis. The Quantitative Insulin Sensitivity Check Index (QUICKI) was calculated from fasting insulin and glucose values. Plasma serpinB1 levels were measured using an ELISA assay. Simple linear correlation analyses were performed to evaluate the relationship between serpinB1 and measures of insulin sensitivity and β -cell function. Circulating serpinB1 levels were unrelated to age, sex, race, BMI, or percent body fat. SI but not AIR significantly correlated with circulating serpinB1 levels ( r  = 0.23, P  < 0.05). QUICKI tended to positively correlate with serpinB1 ( r  = 0.16, P  = 0.09). Circulating serpinB1 is directly associated with insulin sensitivity but not β -cell function in non-diabetic adults. Whether this modest association plays a role in insulin sensitivity in humans remains to be clarified. Published [2017]. This article is a U.S. Government work and is in the public domain in the USA.

A comparison of cell-free placental messenger ribonucleic acid and color Doppler ultrasound for the prediction of placental invasion in patients with placenta accreta

PubMed Central

Naghshineh, Elham; Khorvash, Elahe; Kamali, Sara

2015-01-01

Background: The aim of the present study was to comparison between cell-free placental messenger ribonucleic acid (mRNA) and Doppler ultrasound for the prediction of placental invasion in women with placenta accreta. Materials and Methods: In this cross-sectional study, 50 pregnant women at risk for placenta accreta underwent color Doppler and assessment of cell-free placental mRNA. Real-time reverse-transcription polymerase chain reaction was used for measurement of cell-free placental mRNA in maternal plasma. Based on the findings at cesarean delivery and histological examination, patients were divided into two groups of women with and without placenta accrete. To compare of the mean of mRNA levels between the two groups we used independent t-test and to compare of the mean of age and gestational age at sonography we used Mann-Whitney test. For determination of sensitivity and specificity and the cut-off point of mRNA levels we used the receiver operating characteristic curve. Results: A total of 50 women with a mean age of 30.24 ± 4.905 years entered the study and 12 (24%) patients were diagnosed with placenta accreta. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Doppler ultrasound were 83.3%, 78.9%, 56% and 94%, respectively. Results of our study showed if we consider a cut-off point equal to 3.325, with sensitivity and specificity of 0.917 and 0.789, respectively and the sensitivity, specificity, PPV and NPV of mRNA with were cut-off point of 3.325 were 91.7%, 78.9%, 57.9% and 96.8%, respectively. Conclusions: Cell-free mRNA is an acceptable, easy made, functional test with sensitivity, specificity, PPV and NPV more than Doppler ultrasound for diagnosis and prediction of incidence of placenta accrete and we recommend the use of cell-free mRNA test for diagnosis of placenta accreta. PMID:25709996

A comparison of cell-free placental messenger ribonucleic acid and color Doppler ultrasound for the prediction of placental invasion in patients with placenta accreta.

PubMed

Naghshineh, Elham; Khorvash, Elahe; Kamali, Sara

2015-01-01

The aim of the present study was to comparison between cell-free placental messenger ribonucleic acid (mRNA) and Doppler ultrasound for the prediction of placental invasion in women with placenta accreta. In this cross-sectional study, 50 pregnant women at risk for placenta accreta underwent color Doppler and assessment of cell-free placental mRNA. Real-time reverse-transcription polymerase chain reaction was used for measurement of cell-free placental mRNA in maternal plasma. Based on the findings at cesarean delivery and histological examination, patients were divided into two groups of women with and without placenta accrete. To compare of the mean of mRNA levels between the two groups we used independent t-test and to compare of the mean of age and gestational age at sonography we used Mann-Whitney test. For determination of sensitivity and specificity and the cut-off point of mRNA levels we used the receiver operating characteristic curve. A total of 50 women with a mean age of 30.24 ± 4.905 years entered the study and 12 (24%) patients were diagnosed with placenta accreta. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Doppler ultrasound were 83.3%, 78.9%, 56% and 94%, respectively. Results of our study showed if we consider a cut-off point equal to 3.325, with sensitivity and specificity of 0.917 and 0.789, respectively and the sensitivity, specificity, PPV and NPV of mRNA with were cut-off point of 3.325 were 91.7%, 78.9%, 57.9% and 96.8%, respectively. Cell-free mRNA is an acceptable, easy made, functional test with sensitivity, specificity, PPV and NPV more than Doppler ultrasound for diagnosis and prediction of incidence of placenta accrete and we recommend the use of cell-free mRNA test for diagnosis of placenta accreta.

Action of caffeine on x-irradiated HeLa cells. III. enhancement of x-ray-induced killing during G/sub 2/ arrest

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

Busse, P.M.; Bose, S.K.; Jones, R.W.

1978-11-01

The ability of caffeine to enhance the expression of potentially lethal x-ray damage in HeLa S3 cells was examined as a function of the age of the cells in the generation cycle. Synchronous populations were irradiated at different times after mitotic collection and treated for various intervals with 1 mM caffeiene, which causes negligible killing of unirradiated cells. The response was thereby determined as a function of cell age at both the time of irradiation and the time of exposure to caffeine. The amount of cell killing depends strongly on when in the cycle caffeine is present and only weaklymore » on when the cells are irradiated. If cells are irradiated in early G/sub 1/, caffeine treatment enhances killing for 2 to 3 hr. No additional enhancement is observed until 16 to 17 hr postcollection, corresponding to G/sub 2/; here they enter a second period of much greater sensitivity. Similarly, fluorodeoxyuridine resynchronized cells irradiated during S and treated with caffeine suffer no enhanced killing until they pass into this sensitive phase in G/sub 2/, approximately 7 hr after release from the fluorodeoxyuridine block. The sensitive period appears to coincide with G/sub 2/ arrest. The rate and extent of killing during this period are dependent upon the x-ray dose and the caffeine concentration. In the absence of caffeine, cells irradiated in G/sub 1/ lose sensitivity to caffeine in about 9 hr; they do so faster in G/sub 2/. It is concluded that the potentially lethal x-ray damage expressed on treatment with caffeine is retained for many hours in the presence of caffeine and is maximally manifested by G/sub 2/-arrested cells.« less

Age-associated loss of selectivity in human olfactory sensory neurons

PubMed Central

Rawson, Nancy E.; Gomez, George; Cowart, Beverly J.; Kriete, Andres; Pribitkin, Edmund; Restrepo, Diego

2011-01-01

We report a cross-sectional study of olfactory impairment with age based on both odorant-stimulated responses of human olfactory sensory neurons (OSNs) and tests of olfactory threshold sensitivity. A total of 621 OSNs from 440 subjects in two age groups of younger ( 45 years) and older (≥60 years) subjects were investigated using fluorescence intensity ratio fura-2 imaging. OSNs were tested for responses to two odorant mixtures, as well as to subsets of and individual odors in those mixtures. Whereas cells from younger donors were highly selective in the odorants to which they responded, cells from older donors were more likely to respond to multiple odor stimuli, despite a loss in these subjects’ absolute olfactory sensitivity, suggesting a loss of specificity. This degradation in peripheral cellular specificity may impact odor discrimination and olfactory adaptation in the elderly. It is also possible that chronic adaptation as a result of reduced specificity contributes to observed declines in absolute sensitivity. PMID:22074806

[Regulation of age-dependent phenomena. Influence of C6-substituted purines on cell aggregation and cell migration in primary cultures of lense epithelial cells].

PubMed

Glässer, D; Iwig, M; Weber, E

1975-01-01

The existence of an age dependent latent period of cell emigration has been proved in the primary culture of epithelial cells of bovine lenses. The previously described aggregation phenomenon as well as the latent period of the cell emigration increase with the age of the sponsor animals. Extracellular adenine and other C6-substituted purines, isolated from the cells themselves and added to the medium, act the same way on the lens cells in the primary culture as the increasing age of the sponsor animals. Adenine stimulates cell aggregation and inhibits the adhesion of the cells to the substratum, the cell flattening and the cell migration. The adenine action has been proved down to a concentration of 3 X 10(-6) M. During the primary culture, the lens cells gradually los the adenine sensitivity. The adenine action also occurs on single cells, isolated by trypsination, it differs from the reaction of ouabain and can be removed at low concentration by washing procedures. The results favour the suggestion C6-substituted purines to be involved in cell ageing.

Identifying Candidate Genes that Underlie Cellular pH Sensitivity in Serotonin Neurons Using Transcriptomics: A Potential Role for Kir5.1 Channels

PubMed Central

Puissant, Madeleine M.; Mouradian, Gary C.; Liu, Pengyuan; Hodges, Matthew R.

2017-01-01

Ventilation is continuously adjusted by a neural network to maintain blood gases and pH. Acute CO2 and/or pH regulation requires neural feedback from brainstem cells that encode CO2/pH to modulate ventilation, including but not limited to brainstem serotonin (5-HT) neurons. Brainstem 5-HT neurons modulate ventilation and are stimulated by hypercapnic acidosis, the sensitivity of which increases with increasing postnatal age. The proper function of brainstem 5-HT neurons, particularly during post-natal development is critical given that multiple abnormalities in the 5-HT system have been identified in victims of Sudden Infant Death Syndrome. Here, we tested the hypothesis that there are age-dependent increases in expression of pH-sensitive ion channels in brainstem 5-HT neurons, which may underlie their cellular CO2/pH sensitivity. Midline raphe neurons were acutely dissociated from neonatal and mature transgenic SSePet-eGFP rats [which have enhanced green fluorescent protein (eGFP) expression in all 5-HT neurons] and sorted with fluorescence-activated cell sorting (FACS) into 5-HT-enriched and non-5-HT cell pools for subsequent RNA extraction, cDNA library preparation and RNA sequencing. Overlapping differential expression analyses pointed to age-dependent shifts in multiple ion channels, including but not limited to the pH-sensitive potassium ion (K+) channel genes kcnj10 (Kir4.1), kcnj16 (Kir5.1), kcnk1 (TWIK-1), kcnk3 (TASK-1) and kcnk9 (TASK-3). Intracellular contents isolated from single adult eGFP+ 5-HT neurons confirmed gene expression of Kir4.1, Kir5.1 and other K+ channels, but also showed heterogeneity in the expression of multiple genes. 5-HT neuron-enriched cell pools from selected post-natal ages showed increases in Kir4.1, Kir5.1, and TWIK-1, fitting with age-dependent increases in Kir4.1 and Kir5.1 protein expression in raphe tissue samples. Immunofluorescence imaging confirmed Kir5.1 protein was co-localized to brainstem neurons and glia including 5-HT neurons as expected. However, Kir4.1 protein expression was restricted to glia, suggesting that it may not contribute to 5-HT neuron pH sensitivity. Although there are caveats to this approach, the data suggest that pH-sensitive Kir5.1 channels may underlie cellular CO2/pH chemosensitivity in brainstem 5-HT neurons. PMID:28270749

Age Dependent Variability in Gene Expression in Fischer 344 ...

EPA Pesticide Factsheets

Recent evidence suggests older adults may be a sensitive population with regard to environmental exposure to toxic compounds. One source of this sensitivity could be an enhanced variability in response. Studies on phenotypic differences have suggested that variation in response does increase with age. However, few reports address the question of variation in gene expression as an underlying cause for increased variability of phenotypic response in the aged. In this study, we utilized global analysis to compare variation in constitutive gene expression in the retinae of young (4 mos), middle-aged (11 mos) and aged (23 mos) Fischer 344 rats. Three hundred and forty transcripts were identified in which variance in expression increased from 4 to 23 mos of age, while only twelve transcripts were found for which it decreased. Functional roles for identified genes were clustered in basic biological categories including cell communication, function, metabolism and response to stimuli. Our data suggest that population stochastically-induced variability should be considered in assessing sensitivity due to old age. Recent evidence suggests older adults may be a sensitive population with regard to environmental exposure to toxic compounds. One source of this sensitivity could be an enhanced variability in response. Studies on phenotypic differences have suggested that variation in response does increase with age. However, few reports address the question of variation in

The comet assay: Reflections on its development, evolution and applications.

PubMed

Singh, Narendra P

2016-01-01

The study of DNA damage and its repair is critical to our understanding of human aging and cancer. This review reflects on the development of a simple technique, now known as the comet assay, to study the accumulation of DNA damage and its repair. It describes my journey into aging research and the need for a method that sensitively quantifies DNA damage on a cell-by-cell basis and on a day-by-day basis. My inspirations, obstacles and successes on the path to developing this assay and improving its reliability and sensitivity are discussed. Recent modifications, applications, and the process of standardizing the technique are also described. What was once untried and unknown has become a technique used around the world for understanding and monitoring DNA damage. The comet assay's use has grown exponentially in the new millennium, as emphasis on studying biological phenomena at the single-cell level has increased. I and others have applied the technique across cell types (including germ cells) and species (including bacteria). As it enters new realms and gains clinical relevance, the comet assay may very well illuminate human aging and its prevention. Copyright © 2016. Published by Elsevier B.V.

Effects of aging and sensory loss on glial cells in mouse visual and auditory cortices.

PubMed

Tremblay, Marie-Ève; Zettel, Martha L; Ison, James R; Allen, Paul D; Majewska, Ania K

2012-04-01

Normal aging is often accompanied by a progressive loss of receptor sensitivity in hearing and vision, whose consequences on cellular function in cortical sensory areas have remained largely unknown. By examining the primary auditory (A1) and visual (V1) cortices in two inbred strains of mice undergoing either age-related loss of audition (C57BL/6J) or vision (CBA/CaJ), we were able to describe cellular and subcellular changes that were associated with normal aging (occurring in A1 and V1 of both strains) or specifically with age-related sensory loss (only in A1 of C57BL/6J or V1 of CBA/CaJ), using immunocytochemical electron microscopy and light microscopy. While the changes were subtle in neurons, glial cells and especially microglia were transformed in aged animals. Microglia became more numerous and irregularly distributed, displayed more variable cell body and process morphologies, occupied smaller territories, and accumulated phagocytic inclusions that often displayed ultrastructural features of synaptic elements. Additionally, evidence of myelination defects were observed, and aged oligodendrocytes became more numerous and were more often encountered in contiguous pairs. Most of these effects were profoundly exacerbated by age-related sensory loss. Together, our results suggest that the age-related alteration of glial cells in sensory cortical areas can be accelerated by activity-driven central mechanisms that result from an age-related loss of peripheral sensitivity. In light of our observations, these age-related changes in sensory function should be considered when investigating cellular, cortical, and behavioral functions throughout the lifespan in these commonly used C57BL/6J and CBA/CaJ mouse models. Copyright © 2012 Wiley Periodicals, Inc.

Effects of aging and sensory loss on glial cells in mouse visual and auditory cortices

PubMed Central

Tremblay, Marie-Ève; Zettel, Martha L.; Ison, James R.; Allen, Paul D.; Majewska, Ania K.

2011-01-01

Normal aging is often accompanied by a progressive loss of receptor sensitivity in hearing and vision, whose consequences on cellular function in cortical sensory areas have remained largely unknown. By examining the primary auditory (A1) and visual (V1) cortices in two inbred strains of mice undergoing either age-related loss of audition (C57BL/6J) or vision (CBA/CaJ), we were able to describe cellular and subcellular changes that were associated with normal aging (occurring in A1 and V1 of both strains) or specifically with age-related sensory loss (only in A1 of C57BL/6J or V1 of CBA/CaJ), using immunocytochemical electron microscopy and light microscopy. While the changes were subtle in neurons, glial cells and especially microglia were transformed in aged animals. Microglia became more numerous and irregularly distributed, displayed more variable cell body and process morphologies, occupied smaller territories, and accumulated phagocytic inclusions that often displayed ultrastructural features of synaptic elements. Additionally, evidence of myelination defects were observed, and aged oligodendrocytes became more numerous and were more often encountered in contiguous pairs. Most of these effects were profoundly exacerbated by age-related sensory loss. Together, our results suggest that the age-related alteration of glial cells in sensory cortical areas can be accelerated by activity-driven central mechanisms that result from an age-related loss of peripheral sensitivity. In light of our observations, these age-related changes in sensory function should be considered when investigating cellular, cortical and behavioral functions throughout the lifespan in these commonly used C57BL/6J and CBA/CaJ mouse models. PMID:22223464

NK cells of the oldest seniors represent constant and resistant to stimulation high expression of cellular protective proteins SIRT1 and HSP70.

PubMed

Kaszubowska, Lucyna; Foerster, Jerzy; Kaczor, Jan Jacek; Schetz, Daria; Ślebioda, Tomasz Jerzy; Kmieć, Zbigniew

2018-01-01

Natural killer cells (NK cells) are cytotoxic lymphocytes of innate immunity that reveal some immunoregulatory properties, however, their role in the process of ageing is not completely understood. The study aimed to analyze the expression of proteins involved in cellular stress response: sirtuin 1 (SIRT1), heat shock protein 70 (HSP70) and manganese superoxide dismutase (SOD2) in human NK cells with reference to the process of ageing. Non-stimulated and stimulated with IL-2, LPS or PMA with ionomycin cells originated from peripheral blood samples of: seniors aged over 85 ('the oldest'; n  = 25; 88.5 ± 0.5 years, mean ± SEM), seniors aged under 85 ('the old'; n  = 30; 75.6 ± 0.9 years) and the young ( n  = 31; 20.9 ± 0.3 years). The relationships between the levels of expression of cellular protective proteins in the studied population were also analyzed. The concentrations of carbonyl groups and 8-isoprostanes, markers of oxidative stress, in both stimulated and non-stimulated cultured NK cells were measured to assess the level of the oxidative stress in the cells. The oldest seniors varied from the other age groups by significantly higher expression of SIRT1 and HSP70 both in non-stimulated and stimulated NK cells. These cells also appeared to be resistant to further stimulations with IL-2, LPS or PMA with ionomycin. Highly positive correlations between SIRT1 and intracellular HSP70 in both stimulated and non-stimulated NK cells were observed. SOD2 presented low expression in non-stimulated cells, whereas its sensitivity to stimulation increased with age of donors. High positive correlations between SOD2 and surface HSP70 were observed. We found that the markers of oxidative stress in NK cells did not change with ageing. The oldest seniors revealed well developed adaptive stress response in NK cells with increased, constant levels of SIRT1 and intracellular HSP70. They presented also very high positive correlations between expression of these cellular protective proteins both in stimulated and non-stimulated cells. These phenomena may contribute to the long lifespan of this group of elderly. Interestingly, in NK cells SOD2 revealed a distinct role in cellular stress response since it showed sensitivity to stimulation increasing with age of participants. These observations provide novel data concerning the role of NK cells in the process of ageing.

DNA damage, metabolism and aging in pro-inflammatory T cells: Rheumatoid arthritis as a model system.

PubMed

Li, Yinyin; Goronzy, Jörg J; Weyand, Cornelia M

2018-05-01

The aging process is the major driver of morbidity and mortality, steeply increasing the risk to succumb to cancer, cardiovascular disease, infection and neurodegeneration. Inflammation is a common denominator in age-related pathologies, identifying the immune system as a gatekeeper in aging overall. Among immune cells, T cells are long-lived and exposed to intense replication pressure, making them sensitive to aging-related abnormalities. In successful T cell aging, numbers of naïve cells, repertoire diversity and activation thresholds are preserved as long as possible; in maladaptive T cell aging, protective T cell functions decline and pro-inflammatory effector cells are enriched. Here, we review in the model system of rheumatoid arthritis (RA) how maladaptive T cell aging renders the host susceptible to chronic, tissue-damaging inflammation. In T cells from RA patients, known to be about 20years pre-aged, three interconnected functional domains are altered: DNA damage repair, metabolic activity generating energy and biosynthetic precursor molecules, and shaping of plasma membranes to promote T cell motility. In each of these domains, key molecules and pathways have now been identified, including the glycolytic enzymes PFKFB3 and G6PD; the DNA repair molecules ATM, DNA-PKcs and MRE11A; and the podosome marker protein TKS5. Some of these molecules may help in defining targetable pathways to slow the T cell aging process. Copyright © 2017 Elsevier Inc. All rights reserved.

The sensitivity of the QuantiFERON®-TB Gold Plus assay in Zambian adults with active tuberculosis.

PubMed

Telisinghe, L; Amofa-Sekyi, M; Maluzi, K; Kaluba-Milimo, D; Cheeba-Lengwe, M; Chiwele, K; Kosloff, B; Floyd, S; Bailey, S-L; Ayles, H

2017-06-01

To investigate the sensitivity of the new interferon-gamma release assay (IGRA), QuantiFERON®-TB Gold Plus (QFT-Plus), for active TB (used as a surrogate for latent tuberculous infection) in a Zambian TB clinic. Consecutive smear or Xpert® MTB/RIF-positive adult (age 18 years) pulmonary TB patients were recruited between June 2015 and March 2016. Venous blood was tested using QFT-Plus. The sensitivity was defined as the number positive divided by the total number tested. Using logistic regression, factors associated with positive QFT-Plus results were explored. Of 108 patients (median age 32 years, interquartile range 27-38; 73% male; 63% human immunodeficiency virus [HIV] positive), 90 were QFT-Plus-positive, 11 were negative and seven had indeterminate results; sensitivity was 83% (95%CI 75-90). There was no difference in sensitivity by HIV status (HIV-positive 85%, 95%CI 75-93; n = 68 vs. HIV-negative 80%, 95%CI 64-91; n = 40; P = 0.59). In models adjusted for age alone, CD4 cell count <100 cells/μl (OR 0.15, 95%CI 0.02-0.96; P = 0.05) and body mass index <18.5 kg/m2 (OR 0.27, 95%CI 0.08-0.91; P = 0.02) were associated with decreased odds of positive QFT-Plus results. Overall, the sensitivity of QFT-Plus is similar to that of the tuberculin skin test and other IGRAs. While overall sensitivity is not affected by HIV status, QFT-Plus sensitivity was lower among people living with HIV/acquired immune-deficiency syndrome with severe immunosuppression.

Serine- and Threonine/Valine-Dependent Activation of PDK and Tor Orthologs Converge on Sch9 to Promote Aging

PubMed Central

Fabrizio, Paola; Wei, Min; Hu, Jia; Longo, Valter D.

2014-01-01

Dietary restriction extends longevity in organisms ranging from bacteria to mice and protects primates from a variety of diseases, but the contribution of each dietary component to aging is poorly understood. Here we demonstrate that glucose and specific amino acids promote stress sensitization and aging through the differential activation of the Ras/cAMP/PKA, PKH1/2 and Tor/S6K pathways. Whereas glucose sensitized cells through a Ras-dependent mechanism, threonine and valine promoted cellular sensitization and aging primarily by activating the Tor/S6K pathway and serine promoted sensitization via PDK1 orthologs Pkh1/2. Serine, threonine and valine activated a signaling network in which Sch9 integrates TORC1 and Pkh signaling via phosphorylation of threonines 570 and 737 and promoted intracellular relocalization and transcriptional inhibition of the stress resistance protein kinase Rim15. Because of the conserved pro-aging role of nutrient and growth signaling pathways in higher eukaryotes, these results raise the possibility that similar mechanisms contribute to aging in mammals. PMID:24516402

Age-Related Hearing Loss: Quality of Care for Quality of Life

ERIC Educational Resources Information Center

Li-Korotky, Ha-Sheng

2012-01-01

Age-related hearing loss (ARHL), known as presbycusis, is characterized by progressive deterioration of auditory sensitivity, loss of the auditory sensory cells, and central processing functions associated with the aging process. ARHL is the third most prevalent chronic condition in older Americans, after hypertension and arthritis, and is a…

Ultra-sensitive Sequencing Identifies High Prevalence of Clonal Hematopoiesis-Associated Mutations throughout Adult Life.

PubMed

Acuna-Hidalgo, Rocio; Sengul, Hilal; Steehouwer, Marloes; van de Vorst, Maartje; Vermeulen, Sita H; Kiemeney, Lambertus A L M; Veltman, Joris A; Gilissen, Christian; Hoischen, Alexander

2017-07-06

Clonal hematopoiesis results from somatic mutations in hematopoietic stem cells, which give an advantage to mutant cells, driving their clonal expansion and potentially leading to leukemia. The acquisition of clonal hematopoiesis-driver mutations (CHDMs) occurs with normal aging and these mutations have been detected in more than 10% of individuals ≥65 years. We aimed to examine the prevalence and characteristics of CHDMs throughout adult life. We developed a targeted re-sequencing assay combining high-throughput with ultra-high sensitivity based on single-molecule molecular inversion probes (smMIPs). Using smMIPs, we screened more than 100 loci for CHDMs in more than 2,000 blood DNA samples from population controls between 20 and 69 years of age. Loci screened included 40 regions known to drive clonal hematopoiesis when mutated and 64 novel candidate loci. We identified 224 somatic mutations throughout our cohort, of which 216 were coding mutations in known driver genes (DNMT3A, JAK2, GNAS, TET2, and ASXL1), including 196 point mutations and 20 indels. Our assay's improved sensitivity allowed us to detect mutations with variant allele frequencies as low as 0.001. CHDMs were identified in more than 20% of individuals 60 to 69 years of age and in 3% of individuals 20 to 29 years of age, approximately double the previously reported prevalence despite screening a limited set of loci. Our findings support the occurrence of clonal hematopoiesis-associated mutations as a widespread mechanism linked with aging, suggesting that mosaicism as a result of clonal evolution of cells harboring somatic mutations is a universal mechanism occurring at all ages in healthy humans. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Cold hypersensitivity increases with age in mice with sickle cell disease.

PubMed

Zappia, Katherine J; Garrison, Sheldon R; Hillery, Cheryl A; Stucky, Cheryl L

2014-12-01

Sickle cell disease (SCD) is associated with acute vaso-occlusive crises that trigger painful episodes and frequently involves ongoing, chronic pain. In addition, both humans and mice with SCD experience heightened cold sensitivity. However, studies have not addressed the mechanism(s) underlying the cold sensitization or its progression with age. Here we measured thermotaxis behavior in young and aged mice with severe SCD. Sickle mice had a marked increase in cold sensitivity measured by a cold preference test. Furthermore, cold hypersensitivity worsened with advanced age. We assessed whether enhanced peripheral input contributes to the chronic cold pain behavior by recording from C fibers, many of which are cold sensitive, in skin-nerve preparations. We observed that C fibers from sickle mice displayed a shift to warmer (more sensitive) cold detection thresholds. To address mechanisms underlying the cold sensitization in primary afferent neurons, we quantified mRNA expression levels for ion channels thought to be involved in cold detection. These included the transient receptor potential melastatin 8 (Trpm8) and transient receptor potential ankyrin 1 (Trpa1) channels, as well as the 2-pore domain potassium channels, TREK-1 (Kcnk2), TREK-2 (Kcnk10), and TRAAK (Kcnk4). Surprisingly, transcript expression levels of all of these channels were comparable between sickle and control mice. We further examined transcript expression of 83 additional pain-related genes, and found increased mRNA levels for endothelin 1 and tachykinin receptor 1. These factors may contribute to hypersensitivity in sickle mice at both the afferent and behavioral levels. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Quercetin Protects Yeast Saccharomyces cerevisiae pep4 Mutant from Oxidative and Apoptotic Stress and Extends Chronological Lifespan.

PubMed

Alugoju, Phaniendra; Janardhanshetty, Sudharshan Setra; Subaramanian, Subasri; Periyasamy, Latha; Dyavaiah, Madhu

2018-05-01

The yeast Saccharomyces cerevisiae PEP4 gene encodes vacuolar endopeptidase proteinase A (Pep4p), which is a homolog of the human CTSD gene that encodes cathepsin D. Mutation of CTSD gene in human resulted in a number of neurodegenerative diseases. In this study, we have shown that yeast pep4 mutant cells are highly sensitive to oxidative and apoptotic stress induced by hydrogen peroxide and acetic acid, respectively. pep4∆ cells also showed accumulation of reactive oxygen species (ROS), apoptotic markers, and reduced chronological lifespan. In contrast, quercetin pretreatment protected the pep4 mutant from oxidative and apoptotic stress-induced sensitivity by scavenging ROS and reducing apoptotic markers. The percentage viability of quercetin-treated pep4∆ cells was more pronounced and increased stress resistance against oxidant, apoptotic, and heat stress during chronological aging. From our experimental results, we concluded that quercetin protects yeast pep4 mutant cells from oxidative stress and apoptosis, thereby increasing viability during chronological aging.

Exaggerated neurobiological sensitivity to threat as a mechanism linking anxiety with increased risk for diseases of aging

PubMed Central

O’Donovan, Aoife; Slavich, George M; Epel, Elissa S.; Neylan, Thomas C

2015-01-01

Anxiety disorders increase risk for the early development of several diseases of aging. Elevated inflammation, a common risk factor across diseases of aging, may play a key role in the relationship between anxiety and physical disease. However, the neurobiological mechanisms linking anxiety with elevated inflammation remain unclear. In this review, we present a neurobiological model of the mechanisms by which anxiety promotes inflammation. Specifically we propose that exaggerated neurobiological sensitivity to threat in anxious individuals may lead to sustained threat perception, which is accompanied by prolonged activation of threat-related neural circuitry and threat-responsive biological systems including the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system (ANS), and inflammatory response. Over time, this pattern of responding can promote chronic inflammation through structural and functional brain changes, altered sensitivity of immune cell receptors, dysregulation of the HPA axis and ANS, and accelerated cellular aging. Chronic inflammation, in turn, increases risk for diseases of aging. Exaggerated neurobiological sensitivity to threat may thus be a treatment target for reducing disease risk in anxious individuals. PMID:23127296

The sensitivity of the QuantiFERON®-TB Gold Plus assay in Zambian adults with active tuberculosis

PubMed Central

Amofa-Sekyi, M.; Maluzi, K.; Kaluba-Milimo, D.; Cheeba-Lengwe, M.; Chiwele, K.; Kosloff, B.; Floyd, S.; Bailey, S-L.; Ayles, H.

2017-01-01

SUMMARY SETTING AND OBJECTIVE: To investigate the sensitivity of the new interferon-gamma release assay (IGRA), QuantiFERON®-TB Gold Plus (QFT-Plus), for active TB (used as a surrogate for latent tuberculous infection) in a Zambian TB clinic. DESIGN: Consecutive smear or Xpert® MTB/RIF-positive adult (age ⩾18 years) pulmonary TB patients were recruited between June 2015 and March 2016. Venous blood was tested using QFT-Plus. The sensitivity was defined as the number positive divided by the total number tested. Using logistic regression, factors associated with positive QFT-Plus results were explored. RESULTS: Of 108 patients (median age 32 years, interquartile range 27–38; 73% male; 63% human immunodeficiency virus [HIV] positive), 90 were QFT-Plus-positive, 11 were negative and seven had indeterminate results; sensitivity was 83% (95%CI 75–90). There was no difference in sensitivity by HIV status (HIV-positive 85%, 95%CI 75–93; n = 68 vs. HIV-negative 80%, 95%CI 64–91; n = 40; P = 0.59). In models adjusted for age alone, CD4 cell count <100 cells/μl (OR 0.15, 95%CI 0.02–0.96; P=0.05) and body mass index <18.5 kg/m2 (OR 0.27, 95%CI 0.08–0.91; P = 0.02) were associated with decreased odds of positive QFT-Plus results. CONCLUSION: Overall, the sensitivity of QFT-Plus is similar to that of the tuberculin skin test and other IGRAs. While overall sensitivity is not affected by HIV status, QFT-Plus sensitivity was lower among people living with HIV/acquired immune-deficiency syndrome with severe immunosuppression. PMID:28482964

Advanced glycation endproducts alter functions and promote apoptosis in endothelial progenitor cells through receptor for advanced glycation endproducts mediate overpression of cell oxidant stress.

PubMed

Chen, Jianfei; Song, Minbao; Yu, Shiyong; Gao, Pan; Yu, Yang; Wang, Hong; Huang, Lan

2010-02-01

Endothelial progenitor cells (EPCs) play an important role in preventing atherosclerosis. The factors that regulate the function of EPCs are not completely clear. Increased formation of advanced glycation endproducts (AGEs) is generally regarded as one of the main mechanisms responsible for vascular damage in patients with diabetes and atherosclerosis. AGEs lead to the generation of reactive oxygen species (ROS) and part of the regenerative capacity of EPCs seems to be due to their low baseline ROS levels and reduced sensitivity to ROS-induced cell apoptosis. Therefore, we tested the hypothesis that AGEs can alter functions and promote apoptosis in EPCs through overpress cell oxidant stress. EPCs, isolated from bone marrow, were cultured in the absence or presence of AGEs (50, 100, and 200 microg/ml). A modified Boyden's chamber was used to assess the migration of EPCs and the number of recultured EPCs was counted to measure the adhesiveness function. MTT assay was used to determine the proliferation function. ROS were analyzed using the ROS assay kit. A spectrophotometer was used to assess superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity, and PCR was used to test mRNA expression of SOD and GSH-PX. SiRNA was used to block receptor for advanced glycation endproducts (RAGEs) expression. Apoptosis was evaluated by Annexin V immunostaining and TUNEL staining. Co-culturing with AGEs increases ROS production, decreases anti-oxidant defenses, overpresses oxidant stress, inhibits the proliferation, migration, and adhesion of EPCs, and induces EPCs apoptosis. In addition, these effects were attenuated during block RAGE protein expression by siRNA. AGEs may serve to impair EPCs functions through RAGE-mediate oxidant stress, and promote EPCs sensitivity toward oxidative-stress-mediated apoptosis, which indicates a new pathophysiological mechanism of disturbed vascular adaptation in atherosclerosis and suggests that lower levels of AGEs might improve the success of progenitor cell therapy.

Roles of O-GlcNAc in chronic diseases of aging.

PubMed

Banerjee, Partha S; Lagerlöf, Olof; Hart, Gerald W

2016-10-01

O-GlcNAcylation, a dynamic nutrient and stress sensitive post-translational modification, occurs on myriad proteins in the cell nucleus, cytoplasm and mitochondria. O-GlcNAcylation serves as a nutrient sensor to regulate signaling, transcription, translation, cell division, metabolism, and stress sensitivity in all cells. Aberrant protein O-GlcNAcylation plays a critical role both in the development, as well as in the progression of a variety of age related diseases. O-GlcNAcylation underlies the etiology of diabetes, and changes in specific protein O-GlcNAc levels and sites are responsible for insulin expression and sensitivity and glucose toxicity. Abnormal O-GlcNAcylation contributes directly to diabetes related dysfunction of the heart, kidney and eyes and affects progression of cardiomyopathy, nephropathy and retinopathy. O-GlcNAcylation is a critical modification in the brain and plays a role in both plaque and tangle formation, thus making its study important in neurodegenerative disorders. O-GlcNAcylation also affects cellular growth and metabolism during the development and metastasis of cancer. Finally, alterations in O-GlcNAcylation of transcription factors in macrophages and lymphocytes affect inflammation and cytokine production. Thus, O-GlcNAcylation plays key roles in many of the major diseases associated with aging. Elucidation of its specific functions in both normal and diseased tissues is likely to uncover totally novel avenues for therapeutic intervention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Telomere length analysis.

PubMed

Canela, Andrés; Klatt, Peter; Blasco, María A

2007-01-01

Most somatic cells of long-lived species undergo telomere shortening throughout life. Critically short telomeres trigger loss of cell viability in tissues, which has been related to alteration of tissue function and loss of regenerative capabilities in aging and aging-related diseases. Hence, telomere length is an important biomarker for aging and can be used in the prognosis of aging diseases. These facts highlight the importance of developing methods for telomere length determination that can be employed to evaluate telomere length during the human aging process. Telomere length quantification methods have improved greatly in accuracy and sensitivity since the development of the conventional telomeric Southern blot. Here, we describe the different methodologies recently developed for telomere length quantification, as well as their potential applications for human aging studies.

Dietery acai fruit improves cognition in aged rats

USDA-ARS?s Scientific Manuscript database

Açai is a black-purple fruit (genus Euterpe) cultivated in the Amazon delta and in Brazil (Euterpe oleracea Mart.; EO), as well as Bolivia (Euterpe precatoria Mart.; EP). The fruit’s pulp is known to be rich in polyphenolics that may affect cell-to-cell signaling, receptor sensitivity, inflammatory...

Olive (Olea europaea L.) leaf polyphenols improve insulin sensitivity in middle-aged overweight men: a randomized, placebo-controlled, crossover trial.

PubMed

de Bock, Martin; Derraik, José G B; Brennan, Christine M; Biggs, Janene B; Morgan, Philip E; Hodgkinson, Steven C; Hofman, Paul L; Cutfield, Wayne S

2013-01-01

Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans. To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol per day) on insulin action and cardiovascular risk factors in middle-aged overweight men. Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.4 ± 5.5 years and BMI 28.0 ± 2.0 kg/m(2)) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks, crossing over to other treatment after a 6-week washout. Primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness. Treatment evaluations were based on the intention-to-treat principle. All participants took >96% of prescribed capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to placebo. There was also a 28% improvement in pancreatic β-cell responsiveness (p = 0.013). OLE supplementation also led to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were however, no effects on interleukin-8, TNF-α, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function. Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic β-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome.

Insulin Sensitivity and Secretion in Obese Type 2 Diabetic Women after Various Bariatric Operations

PubMed Central

Vrbikova, Jana; Kunesova, Marie; Kyrou, Ioannis; Tura, Andrea; Hill, Martin; Grimmichova, Tereza; Dvorakova, Katerina; Sramkova, Petra; Dolezalova, Karin; Lischkova, Olga; Vcelak, Josef; Hainer, Vojtech; Bendlova, Bela; Kumar, Sudhesh; Fried, Martin

2017-01-01

Objective To compare the effects of biliopancreatic diversion (BPD) and laparoscopic gastric banding (LAGB) on insulin sensitivity and secretion with the effects of laparoscopic gastric plication (P). Methods A total of 52 obese women (age 30-66 years) suffering from type 2 diabetes mellitus (T2DM) were prospectively recruited into three study groups: 16 BPD; 16 LAGB, and 20 P. Euglycemic clamps and mixed meal tolerance tests were performed before, at 1 month and at 6 months after bariatric surgery. Beta cell function derived from the meal test parameters was evaluated using mathematical modeling. Results Glucose disposal per kilogram of fat free mass (a marker of peripheral insulin sensitivity) increased significantly in all groups, especially after 1 month. Basal insulin secretion decreased significantly after all three types of operations, with the most marked decrease after BPD compared with P and LAGB. Total insulin secretion decreased significantly only following the BPD. Beta cell glucose sensitivity did not change significantly post-surgery in any of the study groups. Conclusion We documented similar improvement in insulin sensitivity in obese T2DM women after all three study operations during the 6-month postoperative follow-up. Notably, only BPD led to decreased demand on beta cells (decreased integrated insulin secretion), but without increasing the beta cell glucose sensitivity. PMID:27951535

Epigenetic regulation of cell fate reprogramming in aging and disease: A predictive computational model.

PubMed

Folguera-Blasco, Núria; Cuyàs, Elisabet; Menéndez, Javier A; Alarcón, Tomás

2018-03-01

Understanding the control of epigenetic regulation is key to explain and modify the aging process. Because histone-modifying enzymes are sensitive to shifts in availability of cofactors (e.g. metabolites), cellular epigenetic states may be tied to changing conditions associated with cofactor variability. The aim of this study is to analyse the relationships between cofactor fluctuations, epigenetic landscapes, and cell state transitions. Using Approximate Bayesian Computation, we generate an ensemble of epigenetic regulation (ER) systems whose heterogeneity reflects variability in cofactor pools used by histone modifiers. The heterogeneity of epigenetic metabolites, which operates as regulator of the kinetic parameters promoting/preventing histone modifications, stochastically drives phenotypic variability. The ensemble of ER configurations reveals the occurrence of distinct epi-states within the ensemble. Whereas resilient states maintain large epigenetic barriers refractory to reprogramming cellular identity, plastic states lower these barriers, and increase the sensitivity to reprogramming. Moreover, fine-tuning of cofactor levels redirects plastic epigenetic states to re-enter epigenetic resilience, and vice versa. Our ensemble model agrees with a model of metabolism-responsive loss of epigenetic resilience as a cellular aging mechanism. Our findings support the notion that cellular aging, and its reversal, might result from stochastic translation of metabolic inputs into resilient/plastic cell states via ER systems.

Key role of T cell defects in age-related vulnerability to West Nile virus.

PubMed

Brien, James D; Uhrlaub, Jennifer L; Hirsch, Alec; Wiley, Clayton A; Nikolich-Zugich, Janko

2009-11-23

West Nile virus (WNV) infection causes a life-threatening meningoencephalitis that becomes increasingly more prevalent over the age of 50 and is 40-50x more prevalent in people over the age of 70, compared with adults under the age of 40. In a mouse model of age-related vulnerability to WNV, we demonstrate that death correlates with increased viral titers in the brain and that this loss of virus control with age was the result of defects in the CD4 and CD8 T cell response against WNV. Specific age-related defects in T cell responses against dominant WNV epitopes were detected at the level of cytokine and lytic granule production, each of which are essential for resistance against WNV, and in the ability to generate multifunctional anti-WNV effector T cells, which are believed to be critical for robust antiviral immunity. In contrast, at the peak of the response, old and adult T cells exhibited superimposable peptide sensitivity. Most importantly, although the adult CD4 or CD8 T cells readily protected immunodeficient mice upon adoptive transfer, old T cells of either subset were unable to provide WNV-specific protection. Consistent with a profound qualitative and quantitative defect in T cell immunity, old brains contained at least 12x fewer total effector CD8 T cells compared with adult mice at the peak of brain infection. These findings identify potential targets for immunomodulation and treatment to combat lethal WNV infection in the elderly.

Dietary acai fruit improves cognition and mobility in aged rats

USDA-ARS?s Scientific Manuscript database

Açai is a black-purple fruit (genus Euterpe) cultivated in the Amazon delta and in Brazil (Euterpe oleracea Mart. -EO), as well as Bolivia (Euterpe precatoria Mart. - EP), and it is known to be rich in polyphenolics that may affect cell-to-cell signaling, receptor sensitivity, inflammatory enzyme ac...

β-Cell lipotoxicity after an overnight intravenous lipid challenge and free fatty acid elevation in African American versus American white overweight/obese adolescents.

PubMed

Hughan, Kara S; Bonadonna, Riccardo C; Lee, SoJung; Michaliszyn, Sara F; Arslanian, Silva A

2013-05-01

Overweight/obese (OW/OB) African American (AA) adolescents have a more diabetogenic insulin secretion/sensitivity pattern compared with their American white (AW) peers. The present study investigated β-cell lipotoxicity to test whether increased free fatty acid (FFA) levels result in greater β-cell dysfunction in AA vs AW OW/OB adolescents. Glucose-stimulated insulin secretion was modeled, from glucose and C-peptide concentrations during a 2-hour hyperglycemic (225 mg/dL) clamp in 22 AA and 24 AW OW/OB adolescents, on 2 occasions after a 12-hour overnight infusion of either normal saline or intralipid (IL) in a random sequence. β-Cell function relative to insulin sensitivity, the disposition index (DI), was examined during normal saline and IL conditions. Substrate oxidation was evaluated with indirect calorimetry and body composition and abdominal adiposity with dual-energy X-ray absorptiometry and magnetic resonance imaging at L4-L5, respectively. Age, sex, body mass index, total and sc adiposity were similar between racial groups, but visceral adiposity was significantly lower in AAs. During IL infusion, FFAs and fat oxidation increased and insulin sensitivity decreased similarly in AAs and AWs. β-Cell glucose sensitivity of first- and second-phase insulin secretion did not change significantly during IL infusion in either group, but DI in each phase decreased significantly and similarly in AAs and AWs. Overweight/obese AA and AW adolescents respond to an overnight fat infusion with significant declines in insulin sensitivity, DI, and β-cell function relative to insulin sensitivity, suggestive of β-cell lipotoxicity. However, contrary to our hypothesis, there does not seem to be a race differential in β-cell lipotoxicity. Longer durations of FFA elevation may unravel such race-related contrasts.

To call or not to call--that is the question (while driving).

PubMed

Tractinsky, Noam; Ram, Efrat Soffer; Shinar, David

2013-07-01

We studied whether decisions to engage in cell phone conversation while driving and the consequences of such decisions are related to the driver's age, to the road conditions (demands of the driving task), and to the driver's role in initiating the phone call (i.e. the driver as caller vs. as receiver). Two experiments were performed in a driving simulator in which driver age, road conditions and phone conversation, as a secondary task, were manipulated. Engagement in cell phone conversations, performance in the driving and the conversation tasks, and subjective effort assessment were recorded. In general, drivers were more willing to accept incoming calls than to initiate calls. In addition, older and younger drivers were more susceptible to the deleterious effects of phone conversations while driving than middle aged/experienced drivers. While older drivers were aware of this susceptibility by showing sensitivity to road conditions before deciding whether to engage in a call or not, young drivers showed no such sensitivity. The results can guide the development of young driver training programs and point at the need to develop context-aware management systems of in-vehicle cell phone conversations. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Pellett, O.L.; Smith, M.L.; Greene, A.A.

Cystinosis is an autosomal recessive disease in which three clinical forms are recognized: infantile nephropathic, with renal tubular damage by 1 year of age and progressive glomerular insufficiency; intermediate, with tubular and glomerular insufficiency beginning at a later age; benign, with no kidney damage. Skin fibroblasts cultured from patients with all types of cystinosis show increased intralysosomal free (nonprotein) cystine; however, fibroblasts from heterozygotes have normal free-cystine values. To determine whether genetic complementation occurs between the different forms, somatic cell hybrids were constructed between cells from a patient with infantile nephropathic cystinosis and cells from patients with other types ofmore » cystinosis. If complementation occurred, the hybrids would be expected to have normal cystine levels. To construct hybrid cells, a universal parent cell type (TG1-neo), which was hypoxanthine/aminopterin/thymidine (HAT) sensitive and G418 resistant was constructed from an infantile nephropathic cystinosis fibroblast strain. Polyethylene glycol fusion of TG1-neo with other cells that are not HAT sensitive or G418 resistant allowed for selection of hybrid cells in a medium containing HAT and the aminoglycoside G418. As indicated by elevated cystine levels, complementation did not occur between TG1-neo and two different benign cystinosis strains, an intermediate cystinosis strain, or another nephropathic cystinosis cell strain. When a normal fibroblast strain was fused with TG1-neo, all 15 hybrid clones studied contained normal amounts of intracellular free cystine.« less

Sputum colour can identify patients with neutrophilic inflammation in asthma

PubMed Central

Gibson, Peter; Lochrin, Alyssa J; Wood, Lisa; Baines, Katherine J; Simpson, Jodie L

2017-01-01

Introduction Sputum colour is associated with neutrophilic inflammation in chronic bronchitis and chronic obstructive pulmonary disease (COPD). Neutrophilia and sputum expectoration is notable in asthma, but whether sputum colour is associated with and predicts the presence of neutrophilic inflammation in asthma is unknown. The objective of the study is to assess the ability of sputum colour in distinguishing asthma inflammatory phenotypes. Methods Induced sputum samples collected from 271 adults with stable asthma were retrospectively assessed. Sputum colour was determined using the BronkoTest sputum colour chart and correlated to differential cell counts and CXCL-8 concentration. Neutrophilic inflammation was defined as an age-corrected sputum neutrophil proportion (≥61.6% for age 20–40 years; ≥63.2% for age 40–60 and ≥67.2% for age >60 years), whereas neutrophilic bronchitis (NB) was defined as high total cell count (≥5.1×106 cells/mL) plus an increased age-corrected neutrophil proportion. The optimal cut-off for sputum colour to predict neutrophilic inflammation and NB was determined using receiver operator characteristic curve analysis. Results A sputum colour score of ≥3 represented and predicted neutrophilic inflammation with modest accuracy (area under the curve (AUC)=0.64; p<0.001, specificity=78.4%, sensitivity=49.2%). Participants with a sputum colour score of ≥3 had significantly (p<0.05) higher CXCL-8, total cells and neutrophil number and proportion. Sputum colour score was also positively correlated with these factors. Sputum colour score ≥3 predicted NB with reasonably good accuracy (AUC=0.79, p<0.001, specificity=79.3%, sensitivity=70.7%). Conclusions Visual gradation of sputum colour in asthma relates to high total cell count and neutrophilic inflammation. Assessment of sputum colour can identify adults with asthma who are likely to have NB without the need for sputum processing and differential cell count, which may facilitate asthma management. PMID:29071085

Microglial K+ Channel Expression in Young Adult and Aged Mice

PubMed Central

Schilling, Tom; Eder, Claudia

2015-01-01

The K+ channel expression pattern of microglia strongly depends on the cells' microenvironment and has been recognized as a sensitive marker of the cells' functional state. While numerous studies have been performed on microglia in vitro, our knowledge about microglial K+ channels and their regulation in vivo is limited. Here, we have investigated K+ currents of microglia in striatum, neocortex and entorhinal cortex of young adult and aged mice. Although almost all microglial cells exhibited inward rectifier K+ currents upon membrane hyperpolarization, their mean current density was significantly enhanced in aged mice compared with that determined in young adult mice. Some microglial cells additionally exhibited outward rectifier K+ currents in response to depolarizing voltage pulses. In aged mice, microglial outward rectifier K+ current density was significantly larger than in young adult mice due to the increased number of aged microglial cells expressing these channels. Aged dystrophic microglia exhibited outward rectifier K+ currents more frequently than aged ramified microglia. The majority of microglial cells expressed functional BK-type, but not IK- or SK-type, Ca2+-activated K+ channels, while no differences were found in their expression levels between microglia of young adult and aged mice. Neither microglial K+ channel pattern nor K+ channel expression levels differed markedly between the three brain regions investigated. It is concluded that age-related changes in microglial phenotype are accompanied by changes in the expression of microglial voltage-activated, but not Ca2+-activated, K+ channels. PMID:25472417

Sensitivity to neurotoxic stress is not increased in progranulin-deficient mice.

PubMed

Petkau, Terri L; Zhu, Shanshan; Lu, Ge; Fernando, Sarah; Cynader, Max; Leavitt, Blair R

2013-11-01

Loss-of-function mutations in the progranulin (GRN) gene are a common cause of autosomal dominant frontotemporal lobar degeneration, a fatal and progressive neurodegenerative disorder common in people less than 65 years of age. In the brain, progranulin is expressed in multiple regions at varying levels, and has been hypothesized to play a neuroprotective or neurotrophic role. Four neurotoxic agents were injected in vivo into constitutive progranulin knockout (Grn(-/-)) mice and their wild-type (Grn(+/+)) counterparts to assess neuronal sensitivity to toxic stress. Administration of 3-nitropropionic acid, quinolinic acid, kainic acid, and pilocarpine induced robust and measurable neuronal cell death in affected brain regions, but no differential cell death was observed between Grn(+/+) and Grn(-/-) mice. Thus, constitutive progranulin knockout mice do not have increased sensitivity to neuronal cell death induced by the acute chemical models of neuronal injury used in this study. Copyright © 2013. Published by Elsevier Inc.

Squamous cell and basal cell carcinoma of the skin in relation to radiation therapy and potential modification of risk by sun exposure.

PubMed

Karagas, Margaret R; Nelson, Heather H; Zens, Michael S; Linet, Martha; Stukel, Therese A; Spencer, Steve; Applebaum, Katie M; Mott, Leila; Mabuchi, Kiyohiko

2007-11-01

Epidemiologic studies consistently find enhanced risk of basal cell carcinoma of the skin among individuals exposed to ionizing radiation, but it is unclear whether the radiation effect occurs for squamous cell carcinoma. It is also not known whether subgroups of individuals are at greater risk, eg, those with radiation sensitivity or high ultraviolet radiation exposure. We analyzed data from a case-control study of keratinocyte cancers in New Hampshire. Incident cases diagnosed in 1993-1995 and 1997-2000 were identified through a state-wide skin cancer surveillance system, and controls were identified through the Department of Transportation and Center for Medicare and Medicaid Service Files (n = 1121 basal cell carcinoma cases, 854 squamous cell carcinoma cases, and 1049 controls). We found an association between history of radiation treatment and basal cell carcinoma. The association was especially strong for basal cell carcinomas arising within the radiation treatment field (odds ratio = 2.6; 95% confidence interval = 1.5-4.3), and among those treated with radiation therapy before age 20 (3.4; 1.8-6.4), those whose basal cell carcinomas occurred 40 or more years after radiation treatment (3.2; 1.8-5.8), and those treated with radiation for acne (11; 2.7-49). Similar age and time patterns of risk were observed for squamous cell carcinoma, although generally with smaller odds ratios. For basal cell carcinoma, early exposure to radiation treatment was a risk factor largely among those without a history of severe sunburns, whereas for squamous cell carcinoma, radiation treatment was a risk factor primarily among those with a sun-sensitive skin type (ie, a tendency to sunburn). Radiation treatment, particularly if experienced before age 20, seems to increase the long-term risk of both basal and squamous cell carcinomas of the skin. These risks may differ by sun exposure or host response to sunlight exposure.

Leaf age and methodology impact assessments of thermotolerance of Coffea arabica

Treesearch

Danielle E. Marias; Frederick C. Meinzer; Christopher Still

2017-01-01

Key message Mature Coffea arabica leaves were more heat tolerant than expanding leaves, longer recovery time yielded more accurate thermotolerance assessments, and photochemistry was more heat sensitive than cell membranes. Abstract Given...

Mitochondrial-Associated Cell Death Mechanisms Are Reset to an Embryonic-Like State in Aged Donor-Derived iPS Cells Harboring Chromosomal Aberrations

PubMed Central

Prigione, Alessandro; Hossini, Amir M.; Lichtner, Björn; Serin, Akdes; Fauler, Beatrix; Megges, Matthias; Lurz, Rudi; Lehrach, Hans; Zouboulis, Christos C.

2011-01-01

Somatic cells reprogrammed into induced pluripotent stem cells (iPSCs) acquire features of human embryonic stem cells (hESCs) and thus represent a promising source for cellular therapy of debilitating diseases, such as age-related disorders. However, reprogrammed cell lines have been found to harbor various genomic alterations. In addition, we recently discovered that the mitochondrial DNA of human fibroblasts also undergoes random mutational events upon reprogramming. Aged somatic cells might possess high susceptibility to nuclear and mitochondrial genome instability. Hence, concerns over the oncogenic potential of reprogrammed cells due to the lack of genomic integrity may hinder the applicability of iPSC-based therapies for age-associated conditions. Here, we investigated whether aged reprogrammed cells harboring chromosomal abnormalities show resistance to apoptotic cell death or mitochondrial-associated oxidative stress, both hallmarks of cancer transformation. Four iPSC lines were generated from dermal fibroblasts derived from an 84-year-old woman, representing the oldest human donor so far reprogrammed to pluripotency. Despite the presence of karyotype aberrations, all aged-iPSCs were able to differentiate into neurons, re-establish telomerase activity, and reconfigure mitochondrial ultra-structure and functionality to a hESC-like state. Importantly, aged-iPSCs exhibited high sensitivity to drug-induced apoptosis and low levels of oxidative stress and DNA damage, in a similar fashion as iPSCs derived from young donors and hESCs. Thus, the occurrence of chromosomal abnormalities within aged reprogrammed cells might not be sufficient to over-ride the cellular surveillance machinery and induce malignant transformation through the alteration of mitochondrial-associated cell death. Taken together, we unveiled that cellular reprogramming is capable of reversing aging-related features in somatic cells from a very old subject, despite the presence of genomic alterations. Nevertheless, we believe it will be essential to develop reprogramming protocols capable of safeguarding the integrity of the genome of aged somatic cells, before employing iPSC-based therapy for age-associated disorders. PMID:22110631

Panels of tumor-derived RNA markers in peripheral blood of patients with non-small cell lung cancer: their dependence on age, gender and clinical stages.

PubMed

Chian, Chih-Feng; Hwang, Yi-Ting; Terng, Harn-Jing; Lee, Shih-Chun; Chao, Tsui-Yi; Chang, Hung; Ho, Ching-Liang; Wu, Yi-Ying; Perng, Wann-Cherng

2016-08-02

Peripheral blood mononuclear cell (PBMC)-derived gene signatures were investigated for their potential use in the early detection of non-small cell lung cancer (NSCLC). In our study, 187 patients with NSCLC and 310 age- and gender-matched controls, and an independent set containing 29 patients for validation were included. Eight significant NSCLC-associated genes were identified, including DUSP6, EIF2S3, GRB2, MDM2, NF1, POLDIP2, RNF4, and WEE1. The logistic model containing these significant markers was able to distinguish subjects with NSCLC from controls with an excellent performance, 80.7% sensitivity, 90.6% specificity, and an area under the receiver operating characteristic curve (AUC) of 0.924. Repeated random sub-sampling for 100 times was used to validate the performance of classification training models with an average AUC of 0.92. Additional cross-validation using the independent set resulted in the sensitivity 75.86%. Furthermore, six age/gender-dependent genes: CPEB4, EIF2S3, GRB2, MCM4, RNF4, and STAT2 were identified using age and gender stratification approach. STAT2 and WEE1 were explored as stage-dependent using stage-stratified subpopulation. We conclude that these logistic models using different signatures for total and stratified samples are potential complementary tools for assessing the risk of NSCLC.

Alteration of functional state of peripheral blood erythrocytes in women of different age groups at dislipidemia conditions.

PubMed

Ratiani, L; Intskirveli, N; Ormotsadze, G; Sanikidze, T

2011-12-01

The aim of the study was identification of statistically reliable correlations and the cause-effect relationships between viability of red blood cells and dislipidema parametres and/or metabolic disorders, induced by age related alterations of estrogen content, in women of different ages (reproductive, menopausal) On the basis of the analysis of research results we can conclude that in the different age groups of women with atherosclerosis-induced cardiovascular diseases revealed estrogen-related dependence between Tg-s and HDL content, functional status of phereperial blood erytrotcites and severity of dislipidemia. The aterogenic index Tg/HD proved to be sensitive marker of dislipidemia in reproductive aging women, but does't reflect disorders of lipid metabolism in postmenosal women. It was proved the existence of reliable corelation between red blood cells dysfunction indicator, spherulation quality, and atherogenic index Tg/HDL highlights; however, the correlation coefficient is 2 times higher in the reproductive age as in menopause. Spherulation quality of red blood cells at low HDL content showd fast growth rate in reproductive-aged women, and was unsensetive to HDL content in postmenopasal women. It was concluded that age-related lack of estrogens in postmenopausal women indirectly contributes to decrease protection of red blood cells against oxidative damage, reduces their deformabelity and disturbances the rheological properties. So, Spherulation quality of red blood cells may be used as a diagnostic marker of severity of atherosclerosis.

Effects of Combined Calcium and Vitamin D Supplementation on Insulin Secretion, Insulin Sensitivity and β-Cell Function in Multi-Ethnic Vitamin D-Deficient Adults at Risk for Type 2 Diabetes: A Pilot Randomized, Placebo-Controlled Trial

PubMed Central

Gagnon, Claudia; Daly, Robin M.; Carpentier, André; Lu, Zhong X.; Shore-Lorenti, Catherine; Sikaris, Ken; Jean, Sonia; Ebeling, Peter R.

2014-01-01

Objectives To examine whether combined vitamin D and calcium supplementation improves insulin sensitivity, insulin secretion, β-cell function, inflammation and metabolic markers. Design 6-month randomized, placebo-controlled trial. Participants Ninety-five adults with serum 25-hydroxyvitamin D [25(OH)D] ≤55 nmol/L at risk of type 2 diabetes (with prediabetes or an AUSDRISK score ≥15) were randomized. Analyses included participants who completed the baseline and final visits (treatment n = 35; placebo n = 45). Intervention Daily calcium carbonate (1,200 mg) and cholecalciferol [2,000–6,000 IU to target 25(OH)D >75 nmol/L] or matching placebos for 6 months. Measurements Insulin sensitivity (HOMA2%S, Matsuda index), insulin secretion (insulinogenic index, area under the curve (AUC) for C-peptide) and β-cell function (Matsuda index x AUC for C-peptide) derived from a 75 g 2-h OGTT; anthropometry; blood pressure; lipid profile; hs-CRP; TNF-α; IL-6; adiponectin; total and undercarboxylated osteocalcin. Results Participants were middle-aged adults (mean age 54 years; 69% Europid) at risk of type 2 diabetes (48% with prediabetes). Compliance was >80% for calcium and vitamin D. Mean serum 25(OH)D concentration increased from 48 to 95 nmol/L in the treatment group (91% achieved >75 nmol/L), but remained unchanged in controls. There were no significant changes in insulin sensitivity, insulin secretion and β-cell function, or in inflammatory and metabolic markers between or within the groups, before or after adjustment for potential confounders including waist circumference and season of recruitment. In a post hoc analysis restricted to participants with prediabetes, a significant beneficial effect of vitamin D and calcium supplementation on insulin sensitivity (HOMA%S and Matsuda) was observed. Conclusions Daily vitamin D and calcium supplementation for 6 months may not change OGTT-derived measures of insulin sensitivity, insulin secretion and β-cell function in multi-ethnic adults with low vitamin D status at risk of type 2 diabetes. However, in participants with prediabetes, supplementation with vitamin D and calcium may improve insulin sensitivity. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN12609000043235 PMID:25299668

Age-dependent reductions in mitochondrial respiration are exacerbated by calcium in the female rat heart.

PubMed

Hunter, J Craig; Machikas, Alexandra M; Korzick, Donna H

2012-06-01

Cardiovascular disease mortality increases rapidly after menopause by poorly defined mechanisms. Because mitochondrial function and Ca(2+) sensitivity are important regulators of cell death after myocardial ischemia, we sought to determine whether aging and/or estrogen deficiency (ovariectomy) increased mitochondrial Ca(2+) sensitivity. Mitochondrial respiration was measured in ventricular mitochondria isolated from adult (6 months; n = 26) and aged (24 months; n = 25), intact or ovariectomized female rats using the substrates α-ketoglutarate/malate (complex I); succinate/rotenone (complex II); ascorbate/N,N,N',N'-tetramethyl-p-phenylenediamine/antimycin (complex IV). State 2 and 3 respiration was initiated by sequential addition of mitochondria and adenosine diphosphate. Ca(2+) sensitivity was assessed by Ca(2+)-induced swelling of de-energized mitochondria and reduction in state 3 respiration. Propylpyrazole triol (PPT) was administered intraperitoneally 45 minutes before euthanasia to assess mitochondrial protective effects through estrogen receptor (ER) α activation. Aging decreased the respiratory control index (RCI; state 3/state 2) for complexes I and II by 12% and 8%, respectively, independent of ovary status (P < 0.05). Of interest, Ca(2+) induced a greater decrease (18%-30%; P < 0.05) in complex I state 3 respiration in aged and ovariectomized animals, and mitochondrial swelling occurred twice as quickly in aged (vs adult) female rats (P < 0.05). Pretreatment with PPT increased RCI by 8% and 7% at complexes I and II, respectively (P < 0.05) but surprisingly increased Ca(2+) sensitivity. Age-dependent decreases in RCI and sensitization to Ca(2+) may explain in part the age-associated reductions in female ischemic tolerance; however, protection afforded by ER agonism involves more complex mechanisms. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

Age-Dependent Reductions in Mitochondrial Respiration are Exacerbated by Calcium in the Female Rat Heart

PubMed Central

Hunter, J. Craig; Machikas, Alexandra M.; Korzick, Donna H.

2012-01-01

Cardiovascular disease mortality increases rapidly following menopause by poorly defined mechanisms. Since mitochondrial function and Ca2+ sensitivity are important regulators of cell death following myocardial ischemia, we sought to determine if aging and/or estrogen deficiency (ovx) increased mitochondrial Ca2+ sensitivity. Mitochondrial respiration was measured in ventricular mitochondria isolated from adult (6mo; n=26) and aged (24mo; n=25), intact or ovariectomized female rats using the substrates: α-ketoglutarate/malate (Complex I); succinate/rotenone (Complex II); ascorbate/TMPD/Antimycin (Complex IV). State 2 and State 3 respiration was initiated by sequential addition of mitochondria and ADP. Ca2+ sensitivity was assessed by Ca2+-induced swelling of de-energized mitochondria and reduction in state 3 respiration. Propylpyrazole triol (PPT) was administered i.p. 45 min prior to euthanasia to assess mitochondrial protective effects through estrogen receptor (ER) α activation. Aging decreased the respiratory control index (RCI; state 3/state 2) for Complexes I and II by 12% and 8%, respectively, independent of ovary status (p<0.05). Of interest, Ca2+ induced a greater decrease (18–30%; p<0.05) in Complex I state 3 respiration in aged and ovx animals, and mitochondrial swelling occurred twice as quickly in aged (vs. adult) female rats (p<0.05). Pretreatment with PPT increased RCI by 8% and 7% at Complexes I and II, respectively (p<0.05) but surprisingly increased Ca2+ sensitivity. Age-dependent decreases in RCI and sensitization to Ca2+ may explain in part the age-associated reductions in female ischemic tolerance; however protection afforded by ER agonism involves more complex mechanisms. PMID:22555015

Control of growth of juvenile leaves of Eucalyptus globulus: effects of leaf age.

PubMed

Metcalfe, J C; Davies, W J; Pereira, J S

1991-12-01

Biophysical variables influencing the expansion of plant cells (yield threshold, cell wall extensibility and turgor) were measured in individual Eucalyptus globulus leaves from the time of emergence until cessation of growth. Leaf water relations variables and growth rates were determined as relative humidity was changed on an hourly basis. Yield threshold and cell wall extensibility were estimated from plots of leaf growth rate versus turgor. Cell wall extensibility was also measured by the Instron technique, and yield threshold was determined experimentally both by stress relaxation in a psychrometer chamber and by incubation in a range of polyethylene glycol solutions. Once emerging leaves reached approximately 5 cm(2) in size, increases in leaf area were rapid throughout the expansive phase and varied little between light and dark periods. Both leaf growth rate and turgor were sensitive to changes in humidity, and in the longer term, both yield threshold and cell wall extensibility changed as the leaf aged. Rapidly expanding leaves had a very low yield threshold and high cell wall extensibility, whereas mature leaves had low cell wall extensibility. Yield threshold increased with leaf age.

Immune Regulatory Properties of CD117pos Amniotic Fluid Stem Cells Vary According to Gestational Age

PubMed Central

Di Trapani, Mariano; Bassi, Giulio; Fontana, Emanuela; Giacomello, Luca; Pozzobon, Michela; Guillot, Pascale V.; De Coppi, Paolo

2015-01-01

Amniotic Fluid Stem (AFS) cells are broadly multipotent fetal stem cells derived from the positive selection and ex vivo expansion of amniotic fluid CD117/c-kitpos cells. Considering the differentiation potential in vitro toward cell lineages belonging to the three germ layers, AFS cells have raised great interest as a new therapeutic tool, but their immune properties still need to be assessed. We analyzed the in vitro immunological properties of AFS cells from different gestational age in coculture with T, B, and natural killer (NK) cells. Nonactivated (resting) first trimester-AFS cells showed lower expression of HLA class-I molecules and NK-activating ligands than second and third trimester-AFS cells, whose features were associated with lower sensitivity to NK cell-mediated lysis. Nevertheless, inflammatory priming with interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) enhanced resistance of all AFS cell types to NK cytotoxicity. AFS cells modulated lymphocyte proliferation in a different manner according to gestational age: first trimester-AFS cells significantly inhibited T and NK cell proliferation, while second and third trimester-AFS cells were less efficient. In addition, only inflammatory-primed second trimester-AFS cells could suppress B cell proliferation, which was not affected by the first and third trimester-AFS cells. Indolamine 2,3 dioxygenase pathway was significantly involved only in T cell suppression mediated by second and third trimester-AFS cells. Overall, this study shows a number of significant quantitative differences among AFS cells of different gestational age that have to be considered in view of their clinical application. PMID:25072397

Brain aging and neurodegeneration: from a mitochondrial point of view.

PubMed

Grimm, Amandine; Eckert, Anne

2017-11-01

Aging is defined as a progressive time-related accumulation of changes responsible for or at least involved in the increased susceptibility to disease and death. The brain seems to be particularly sensitive to the aging process since the appearance of neurodegenerative diseases, including Alzheimer's disease, is exponential with the increasing age. Mitochondria were placed at the center of the 'free-radical theory of aging', because these paramount organelles are not only the main producers of energy in the cells, but also to main source of reactive oxygen species. Thus, in this review, we aim to look at brain aging processes from a mitochondrial point of view by asking: (i) What happens to brain mitochondrial bioenergetics and dynamics during aging? (ii) Why is the brain so sensitive to the age-related mitochondrial impairments? (iii) Is there a sex difference in the age-induced mitochondrial dysfunction? Understanding mitochondrial physiology in the context of brain aging may help identify therapeutic targets against neurodegeneration. This article is part of a series "Beyond Amyloid". © 2017 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.

Diminished circadian rhythms in hippocampal microglia may contribute to age-related neuroinflammatory sensitization

PubMed Central

Fonken, Laura K.; Kitt, Meagan M.; Gaudet, Andrew D.; Barrientos, Ruth M.; Watkins, Linda R.; Maier, Steven F.

2016-01-01

Aged animals exhibit diminished circadian rhythms, and both aging and circadian disruption sensitize neuroinflammatory responses. Microglia –the innate immune cell of the CNS – possess endogenous timekeeping mechanisms that regulate immune responses. Here, we explored whether aging is associated with disrupted diurnal rhythms in microglia and neuroinflammatory processes. First, hippocampal microglia isolated from young rats (4 mos. F344XBN) rhythmically expressed circadian clock genes, whereas microglia isolated from the hippocampus of aged rats (25 mos.) had aberrant Per1 and Per2 rhythms. Unstimulated microglia from young rats exhibited robust rhythms of TNFα and IL-1β mRNA expression, whereas those from aged rats had flattened and tonically-elevated cytokine expression. Similarly, microglial activation markers were diurnally regulated in the hippocampus of young but not aged rats and diurnal differences in responsiveness to both ex vivo and in vivo inflammatory challenges were abolished in aged rats. Corticosterone is an entraining signal for extra-SCN circadian rhythms. Here, corticosterone stimulation elicited similar Per1 induction in aged and young microglia. Overall, these results indicate that aging dysregulates circadian regulation of neuroinflammatory functions. PMID:27568094

Olive (Olea europaea L.) Leaf Polyphenols Improve Insulin Sensitivity in Middle-Aged Overweight Men: A Randomized, Placebo-Controlled, Crossover Trial

PubMed Central

de Bock, Martin; Derraik, José G. B.; Brennan, Christine M.; Biggs, Janene B.; Morgan, Philip E.; Hodgkinson, Steven C.; Hofman, Paul L.; Cutfield, Wayne S.

2013-01-01

Background Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans. Objective To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol per day) on insulin action and cardiovascular risk factors in middle-aged overweight men. Design Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.4±5.5 years and BMI 28.0±2.0 kg/m2) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks, crossing over to other treatment after a 6-week washout. Primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness. Results Treatment evaluations were based on the intention-to-treat principle. All participants took >96% of prescribed capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to placebo. There was also a 28% improvement in pancreatic β-cell responsiveness (p = 0.013). OLE supplementation also led to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were however, no effects on interleukin-8, TNF-α, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function. Conclusions Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic β-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome. Trial Registration Australian New Zealand Clinical Trials Registry #336317. PMID:23516412

Intracellular human papillomavirus E6, E7 mRNA quantification predicts CIN 2+ in cervical biopsies better than Papanicolaou screening for women regardless of age.

PubMed

Pierry, Deirdre; Weiss, Gerald; Lack, Benjamin; Chen, Victor; Fusco, Judy

2012-08-01

Cervical cancer screening in women younger than 30 years relies on cervical cytology because of the poor performance of human papillomavirus (HPV) DNA testing in this age group. To determine the performance of in-cell HPV E6, E7 mRNA quantification (HPV OncoTect) for the detection of high-grade cervical intraepithelial neoplasia in women younger than 30 years. We analyzed 3133 cytology specimens from a screening population of women aged 19-75 years investigate HPV OncoTect as a triage/secondary screening test for atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cytology in women younger than 30 years. Test results were compared to histology in 246 cases. The sensitivity of E6, E7 mRNA was 89% for CIN 2+ and 100% for CIN 3+ lesions in women 30 years and older. In women younger than 30 years, the sensitivity of E6, E7 mRNA for CIN 2+ lesions was 88% for CIN 2+ and 92% for CIN 3+ lesions. Abnormal cytology (≥ASCUS) exhibited a sensitivity of 89% for CIN 2+ and 100% for CIN 3+ in women 30 years and older and 96% sensitivity for CIN 2+ and 93% sensitivity for CIN 3+ in women younger than 30. The specificity of E6, E7 mRNA was >80% for CIN 2+ and CIN 3+ in both groups of women compared to a specificity of abnormal cytology of <10% for CIN 2+ and CIN 3+ in both groups. HPV OncoTect demonstrates a performance that would be effective for ASCUS/LSIL triage in women including those younger than 30 years.

Acquisition of relative interstrand crosslinker resistance and PARP inhibitor sensitivity in Fanconi anemia head and neck cancers

PubMed Central

Lombardi, Anne J.; Hoskins, Elizabeth E.; Foglesong, Grant D.; Wikenheiser-Brokamp, Kathryn A.; Wiesmüller, Lisa; Hanenberg, Helmut; Andreassen, Paul R.; Jacobs, Allison J.; Olson, Susan B.; Keeble, Winifred W.; Hays, Laura E.; Wells, Susanne I.

2015-01-01

Purpose Fanconi anemia (FA) is an inherited disorder associated with a constitutional defect in the FA DNA repair machinery that is essential for resolution of DNA interstrand crosslinks. Individuals with FA are predisposed to formation of head and neck squamous cell carcinomas (HNSCCs) at a young age. Prognosis is poor, partly due to patient intolerance of chemotherapy and radiation requiring dose reduction, which may lead to early recurrence of disease. Experimental Design Using HNSCC cell lines derived from the tumors of FA patients, and murine HNSCC cell lines derived from the tumors of wild type and Fancc−/− mice, we sought to define FA-dependent chemosensitivity and DNA repair characteristics. We utilized DNA repair reporter assays to explore the preference of FA HNSCC cells for non-homologous end joining (NHEJ). Results Surprisingly, interstrand crosslinker (ICL) sensitivity was not necessarily FA-dependent in human or murine cell systems. Our results suggest that the increased Ku-dependent NHEJ that is expected in FA cells did not mediate relative ICL resistance. ICL exposure resulted in increased DNA damage sensing and repair by poly(ADP-ribose) polymerase (PARP) in FA-deficient cells. Moreover, human and murine FA HNSCC cells were sensitive to PARP inhibition, and sensitivity of human cells was attenuated by FA gene complementation. Conclusions The observed reliance upon PARP-mediated mechanisms reveals a means by which FA HNSCCs can acquire relative resistance to the ICL-based chemotherapy that is a foundation of HNSCC treatment, as well as a potential target for overcoming chemoresistance in the chemosensitive individual. PMID:25609062

Circadian rhythm of the Leydig cells endocrine function is attenuated during aging.

PubMed

Baburski, Aleksandar Z; Sokanovic, Srdjan J; Bjelic, Maja M; Radovic, Sava M; Andric, Silvana A; Kostic, Tatjana S

2016-01-01

Although age-related hypofunction of Leydig cells is well illustrated across species, its circadian nature has not been analyzed. Here we describe changes in circadian behavior in Leydig cells isolated from adult (3-month) and aged (18- and 24-month) rats. The results showed reduced circadian pattern of testosterone secretion in both groups of aged rats despite unchanged LH circadian secretion. Although arrhythmic, the expression of Insl3, another secretory product of Leydig cells, was decreased in both groups. Intracellular cAMP and most important steroidogenic genes (Star, Cyp11a1 and Cyp17a1), together with positive steroidogenic regulator (Nur77), showed preserved circadian rhythm in aging although rhythm robustness and expression level were attenuated in both aged groups. Aging compromised cholesterol mobilization and uptake by Leydig cells: the oscillatory transcription pattern of genes encoding HDL-receptor (Scarb1), hormone sensitive lipase (Lipe, enzyme that converts cholesterol esters from lipid droplets into free cholesterol) and protein responsible for forming the cholesterol esters (Soat2) were flattened in 24-month group. The majority of examined clock genes displayed circadian behavior in expression but only a few of them (Bmal1, Per1, Per2, Per3 and Rev-Erba) were reduced in 24-month-old group. Furthermore, aging reduced oscillatory expression pattern of Sirt1 and Nampt, genes encoding key enzymes that connect cellular metabolism and circadian network. Altogether circadian amplitude of Leydig cell's endocrine function decreased during aging. The results suggest that clock genes are more resistant to aging than genes involved in steroidogenesis supporting the hypothesis about peripheral clock involvement in rhythm maintenance during aging. Copyright © 2015 Elsevier Inc. All rights reserved.

β-Cell Lipotoxicity After an Overnight Intravenous Lipid Challenge and Free Fatty Acid Elevation in African American Versus American White Overweight/Obese Adolescents

PubMed Central

Hughan, Kara S.; Bonadonna, Riccardo C.; Lee, SoJung; Michaliszyn, Sara F.

2013-01-01

Objective: Overweight/obese (OW/OB) African American (AA) adolescents have a more diabetogenic insulin secretion/sensitivity pattern compared with their American white (AW) peers. The present study investigated β-cell lipotoxicity to test whether increased free fatty acid (FFA) levels result in greater β-cell dysfunction in AA vs AW OW/OB adolescents. Research Design and Methods: Glucose-stimulated insulin secretion was modeled, from glucose and C-peptide concentrations during a 2-hour hyperglycemic (225 mg/dL) clamp in 22 AA and 24 AW OW/OB adolescents, on 2 occasions after a 12-hour overnight infusion of either normal saline or intralipid (IL) in a random sequence. β-Cell function relative to insulin sensitivity, the disposition index (DI), was examined during normal saline and IL conditions. Substrate oxidation was evaluated with indirect calorimetry and body composition and abdominal adiposity with dual-energy X-ray absorptiometry and magnetic resonance imaging at L4-L5, respectively. Results: Age, sex, body mass index, total and sc adiposity were similar between racial groups, but visceral adiposity was significantly lower in AAs. During IL infusion, FFAs and fat oxidation increased and insulin sensitivity decreased similarly in AAs and AWs. β-Cell glucose sensitivity of first- and second-phase insulin secretion did not change significantly during IL infusion in either group, but DI in each phase decreased significantly and similarly in AAs and AWs. Conclusions: Overweight/obese AA and AW adolescents respond to an overnight fat infusion with significant declines in insulin sensitivity, DI, and β-cell function relative to insulin sensitivity, suggestive of β-cell lipotoxicity. However, contrary to our hypothesis, there does not seem to be a race differential in β-cell lipotoxicity. Longer durations of FFA elevation may unravel such race-related contrasts. PMID:23526462

Conjunctivally administered NGF antibody reduces pain sensitivity and anxiety-like behavioral responses in aged female mice.

PubMed

Berry, Alessandra; Aloe, Luigi; Rossi, Simona; Bonsignore, Luca T; Capone, Francesca; Alleva, Enrico; Cirulli, Francesca

2010-07-11

This study reports that peripheral administration of Nerve Growth Factor antibodies (ANA) affects behavior in aged female CD-1 mice. ANA increased the propensity of mice to stay and perform behaviors in the anxiogenic open arms of the maze, lowered pain sensitivity and reduced behavioral flexibility in a Morris water maze task, also reducing ChAT immunoreactivity in the basal forebrain. These findings support the hypothesis that topical eye application can represent an alternative route for delivering biologically active compounds into the brain allowing studying the role of NGF on brain cell function. Copyright 2010 Elsevier B.V. All rights reserved.

Effects of social support on glucocorticoid sensitivity of lymphocytes in socially deprived piglets.

PubMed

Tuchscherer, Margret; Kanitz, Ellen; Tuchscherer, Armin; Puppe, Birger

2016-05-01

There is growing evidence that social support given by a conspecific attenuates stress responses of a socially deprived animal. We hypothesized that the presence of a familiar social partner modulates the effectiveness of social buffering as assessed by an altered glucocorticoid sensitivity of immune cells. The current study investigated the effects of a 4-h social deprivation procedure on stress hormone responses and immune cell functions in 7-, 21- and 35-day-old piglets (52 males and 56 females). Within each of the three age categories, nine piglets were deprived of their mother and littermates either alone or with a familiar or unfamiliar age-matched piglet. Compared to non-deprived controls, piglets that were alone displayed significant increases in plasma adrenocorticotropic hormone and cortisol concentrations, and all socially deprived piglets showed a greater in vitro proliferative response of peripheral blood mononuclear cells (PBMCs) to lipopolysaccharide (LPS)-stimulation than controls. Concanavalin A (ConA)-induced in vitro proliferation was not affected by social treatment. Additionally, both the ConA- and LPS-stimulated PBMCs from piglets that experienced any of the deprivation treatments were more resistant to the inhibitory effects of cortisol than PBMCs from the controls in each of the three age categories. Irrespective of the mitogen used, the presence of an age-matched conspecific during deprivation attenuated the dose-dependent cortisol resistance. Here, familiarity between the piglets clearly improved the effectiveness of social support in an age-dependent manner. Collectively, our findings emphasize the benefits of social partners regarding stress coping abilities, with positive implications for animal welfare and health.

Thiazolidinedione treatment and constitutive-PPARγ activation induces ectopic adipogenesis and promotes age-related thymic involution

PubMed Central

Youm, Yun-Hee; Yang, Hyunwon; Amin, Raj; Smith, Steven R.; Leff, Todd; Dixit, Vishwa Deep

2010-01-01

Age-related thymic involution is characterized by reduction in T cell production together with ectopic adipocyte development within the hematopoietic and thymic niches. PPARγ is required for adipocyte development, glucose homeostasis and is a target for several insulin-sensitizing drugs. Our prior studies showed that age-related elevation of PPARγ expression in thymic stromal cells is associated with thymic involution. Here, using clinically relevant pharmacological and genetic manipulations in mouse models, we provide evidence that activation of PPARγ leads to reduction in thymopoiesis. Treatment of aged mice with anti-hyperglycemic PPARγ-ligand class of Thiazolidinedione drug, Rosiglitazone caused robust thymic expression of classical pro-adipogenic transcripts. Rosiglitazone reduced thymic cellularity, lowered the naïve T cell number and T cell receptor excision circles (TRECs) indicative of compromised thymopoiesis. To directly investigate whether PPARγ activation induces thymic involution, we created transgenic mice with constitutive-active PPARγ (CA-PPARg) fusion protein in cells of adipogenic lineage. Importantly, CA-PPARγ transgene was expressed in thymus and in Fibroblast Specific Protein-1/S100A4 (FSP1+) cells, a marker of secondary mesenchymal cells. The CAPPARγ fusion protein mimicked the liganded PPARγ receptor and the transgenic mice displayed increased ectopic thymic adipogenesis and reduced thymopoiesis. Furthermore, the reduction in thymopoiesis in CA-PPARγ mice was associated with higher bone marrow adiposity and lower hematopoietic stem cell progenitor pool. Consistent with lower thymic output, CAPPARγ transgenic mice had restricted T cell receptor (TCR) repertoire diversity. Collectively, our data suggest that activation of PPARγ accelerates thymic aging and thymus-specific PPARγ antagonist may forestall age-related decline in T cell diversity. PMID:20374200

Immune deficiency could be an early risk factor for altered insulin sensitivity in antiretroviral-naive HIV-1-infected patients: the ANRS COPANA cohort.

PubMed

Boufassa, Faroudy; Goujard, Cécile; Viard, Jean-Paul; Carlier, Robert; Lefebvre, Bénédicte; Yeni, Patrick; Bouchaud, Olivier; Capeau, Jacqueline; Meyer, Laurence; Vigouroux, Corinne

2012-01-01

The relationships between immunovirological status, inflammatory markers, insulin resistance and fat distribution have not been studied in recently diagnosed (<1 year) antiretroviral-naive HIV-1-infected patients. We studied 214 antiretroviral-naive patients at enrolment in the metabolic substudy of the ANRS COPANA cohort. We measured clinical, immunovirological and inflammatory parameters, glucose/insulin during oral glucose tolerance test (OGTT), adipokines, subcutaneous and visceral fat surfaces (subcutaneous adipose tissue [SAT] and visceral adipose tissue [VAT], assessed by computed tomography) and the body fat distribution based on dual-energy X-ray absorptiometry (DEXA). Median age was 36 years; 28% of the patients were female and 35% of sub-Saharan origin; 20% had low CD4(+) T-cell counts (≤200/mm(3)). Patients with low CD4(+) T-cell counts were older and more frequently of sub-Saharan Africa origin, had lower body mass index (BMI) but no different SAT/VAT ratio and fat distribution than other patients. They also had lower total, low-density lipoprotein and high-density lipoprotein cholesterolaemia, higher triglyceridaemia and post-OGTT glycaemia, higher markers of insulin resistance (insulin during OGTT and homeostasis model assessment of insulin resistance) and of inflammation (high-sensitivity C-reactive protein, IL-6, tumour necrosis factor (TNF)-α, sTNFR1 and sTNFR2). After adjustment for age, sex, geographic origin, BMI and waist circumference, increased insulin resistance was not related to any inflammatory marker. In multivariate analysis, low CD4(+) T-cell count was an independent risk factor for altered insulin sensitivity (β-coefficient for HOMA-IR: +0.90; P=0.001; CD4(+) T-cell count >500/mm(3) as the reference), in addition to older age (β: +0.26 for a 10-year increase; P=0.01) and higher BMI (β: +0.07 for a 1-kg/m(2) increase; P=0.003). In ART-naive patients, severe immune deficiency but not inflammation could be an early risk factor for altered insulin sensitivity.

The expanding universe of neurotrophic factors: therapeutic potential in aging and age-associated disorders.

PubMed

Lanni, C; Stanga, S; Racchi, M; Govoni, S

2010-01-01

Multiple molecular, cellular, structural and functional changes occur in the brain during aging. Neural cells may respond to these changes adaptively by employing multiple mechanisms in order to maintain the integrity of nerve cell circuits and to facilitate responses to environmental demands. Otherwise, they may succumb to neurodegenerative cascades that result in disorders such as Alzheimer's and Parkinson's diseases. An important role in this balancement is played by neurotrophic factors, which are central to many aspects of nervous system function since they regulate the development, maintenance and survival of neurons and neuron-supporting cells such as glia and oligodendrocytes. A vast amount of evidence indicates that alterations in levels of neurotrophic factors or their receptors can lead to neuronal death and contribute to aging as well as to the pathogenesis of diseases of abnormal trophic support (such as neurodegenerative diseases and depression) and diseases of abnormal excitability (such as epilepsy and central pain sensitization). Cellular and molecular mechanisms by which neurotrophic factors may influence cell survival and excitability are also critically examined to provide novel concepts and targets for the treatment of physiological changes bearing detrimental functional alterations and of different diseases affecting the central nervous system during aging.

p16/ki-67 dual-stain cytology in the triage of ASCUS and LSIL papanicolaou cytology: results from the European equivocal or mildly abnormal Papanicolaou cytology study.

PubMed

Schmidt, Dietmar; Bergeron, Christine; Denton, Karin J; Ridder, Ruediger

2011-06-25

The objective of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual-stain protocol, which simultaneously detects p16(INK4a) and Ki-67 expression in cervical cytology samples, for identifying high-grade cervical intraepithelial neoplasia (CIN2+) in women with Papanicolaou (Pap) cytology results categorized as atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesions (LSIL). Residual liquid-based cytology material from 776 retrospectively collected ASCUS/LSIL cases that were available from a recent study evaluating p16 cytology and HPV testing were subjected to p16/Ki-67 dual staining. The presence of 1 or more double-immunoreactive cell(s) was regarded as a positive test outcome, irrespective of morphology. Test results were correlated to histology follow-up. Sensitivity of p16/Ki-67 dual-stain cytology for biopsy-confirmed CIN2+ was 92.2% (ASCUS) and 94.2% (LSIL), while specificity rates were 80.6% (ASCUS) and 68.0% (LSIL), respectively. Similar sensitivity/specificity profiles were found for both age groups of women aged <30 years versus women aged ≥30 years. Dual-stain cytology showed comparable sensitivity, but significantly higher specificity, when compared with human papillomavirus (HPV) testing. The results of this study show that p16/Ki-67 dual-stain cytology provided a high sensitivity for the detection of underlying CIN2+ in women with ASCUS or LSIL Pap cytology results, comparable to the rates previously reported for HPV testing and p16 single-stain cytology. However, the specificity of this morphology-independent interpretation of p16/Ki-67 dual-stain cytology testing was further improved compared with the earlier p16 single-stain cytology approach, which required morphology interpretation, and it is significantly higher when compared with HPV testing. Copyright © 2011 American Cancer Society.

National collection of embryo morphology data into Society for Assisted Reproductive Technology Clinic Outcomes Reporting System: associations among day 3 cell number, fragmentation and blastomere asymmetry, and live birth rate.

PubMed

Racowsky, Catherine; Stern, Judy E; Gibbons, William E; Behr, Barry; Pomeroy, Kimball O; Biggers, John D

2011-05-01

To evaluate the validity of collecting day 3 embryo morphology variables into the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS). Retrospective. National database-SART CORS. Fresh autologous assisted reproductive technology (ART) cycles from 2006-2007 in which embryos were transferred singly (n=1,020) or in pairs (n=6,508) and embryo morphology was collected. None. Relationship between live birth, maternal age, and morphology of transferred day 3 embryos as defined by cell number, fragmentation, and blastomere symmetry. Logistic multiple regressions and receiver operating characteristic curve analyses were applied to determine specificity and sensitivity for correctly classifying embryos as either failures or successes. Live birth rate was positively associated with increasing cell number up to eight cells (<6 cells: 2.9%; 6 cells: 9.6%; 7 cells: 15.5%; 8 cells: 24.3%; and >8 cells: 16.2%), but was negatively associated with maternal age, increasing fragmentation, and asymmetry scores. An area under the receiver operating curve of 0.753 (95% confidence interval 0.740-0.766) was derived, with a sensitivity of 45.0%, a specificity of 83.2%, and 76.4% of embryos being correctly classified with a cutoff probability of 0.3. This analysis provides support for the validity of collecting morphology fields for day 3 embryos into SART CORS. Standardization of morphology collections will assist in controlling for embryo quality in future database analyses. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Differential impact of glucose levels and advanced glycation end-products on tubular cell viability and pro-inflammatory/profibrotic functions.

PubMed

Franko, Benoit; Brault, Julie; Jouve, Thomas; Beaumel, Sylvain; Benhamou, Pierre-Yves; Zaoui, Philippe; Stasia, Marie José

2014-09-05

High glucose (HG) or synthetic advanced glycation end-products (AGE) conditions are generally used to mimic diabetes in cellular models. Both models have shown an increase of apoptosis, oxidative stress and pro-inflammatory cytokine production in tubular cells. However, the impact of the two conditions combined has rarely been studied. In addition, the impact of glucose level variation due to cellular consumption is not clearly characterized in such experiments. Therefore, the aim of this study was to compare the effect of HG and AGE separately and of both on tubular cell phenotype changes in the HK2 cell line. Moreover, glucose consumption was monitored every hour to maintain the glucose level by supplementation throughout the experiments. We thus observed a significant decrease of apoptosis and H2O2 production in the HK2 cell. HG or AGE treatment induced an increase of total and mitochondrial apoptosis as well as TGF-β release compared to control conditions; however, AGE or HG led to apoptosis preferentially involving the mitochondria pathway. No cumulative effect of HG and AGE treatment was observed on apoptosis. However, a pretreatment with RAGE antibodies partially abolished the apoptotic effect of HG and completely abolished the apoptotic effect of AGE. In conclusion, tubular cells are sensitive to the lack of glucose as well as to the HG and AGE treatments, the AGE effect being more deleterious than the HG effect. Absence of a potential synergistic effect of HG and AGE could indicate that they act through a common pathway, possibly via the activation of the RAGE receptors. Copyright © 2014 Elsevier Inc. All rights reserved.

Acquisition of Relative Interstrand Crosslinker Resistance and PARP Inhibitor Sensitivity in Fanconi Anemia Head and Neck Cancers.

PubMed

Lombardi, Anne J; Hoskins, Elizabeth E; Foglesong, Grant D; Wikenheiser-Brokamp, Kathryn A; Wiesmüller, Lisa; Hanenberg, Helmut; Andreassen, Paul R; Jacobs, Allison J; Olson, Susan B; Keeble, Winifred W; Hays, Laura E; Wells, Susanne I

2015-04-15

Fanconi anemia is an inherited disorder associated with a constitutional defect in the Fanconi anemia DNA repair machinery that is essential for resolution of DNA interstrand crosslinks. Individuals with Fanconi anemia are predisposed to formation of head and neck squamous cell carcinomas (HNSCC) at a young age. Prognosis is poor, partly due to patient intolerance of chemotherapy and radiation requiring dose reduction, which may lead to early recurrence of disease. Using HNSCC cell lines derived from the tumors of patients with Fanconi anemia, and murine HNSCC cell lines derived from the tumors of wild-type and Fancc(-/-) mice, we sought to define Fanconi anemia-dependent chemosensitivity and DNA repair characteristics. We utilized DNA repair reporter assays to explore the preference of Fanconi anemia HNSCC cells for non-homologous end joining (NHEJ). Surprisingly, interstrand crosslinker (ICL) sensitivity was not necessarily Fanconi anemia-dependent in human or murine cell systems. Our results suggest that the increased Ku-dependent NHEJ that is expected in Fanconi anemia cells did not mediate relative ICL resistance. ICL exposure resulted in increased DNA damage sensing and repair by PARP in Fanconi anemia-deficient cells. Moreover, human and murine Fanconi anemia HNSCC cells were sensitive to PARP inhibition, and sensitivity of human cells was attenuated by Fanconi anemia gene complementation. The observed reliance upon PARP-mediated mechanisms reveals a means by which Fanconi anemia HNSCCs can acquire relative resistance to the ICL-based chemotherapy that is a foundation of HNSCC treatment, as well as a potential target for overcoming chemoresistance in the chemosensitive individual. ©2015 American Association for Cancer Research.

Recombinant HSP70 and mild heat shock stimulate growth of aged mesenchymal stem cells.

PubMed

Andreeva, N V; Zatsepina, O G; Garbuz, D G; Evgen'ev, M B; Belyavsky, A V

2016-07-01

Heat shock proteins including the major stress protein HSP70 support intracellular homeostasis and prevent protein damage after a temperature increase and other stressful environmental stimuli, as well as during aging. We have shown earlier that prolonged administration of recombinant human HSP70 to mice exhibiting Alzheimer's-like neurodegeneration as well as during sepsis reduces the clinical manifestations of these pathologies. Herein, we studied the action of recombinant human HSP70 on young and aged mouse mesenchymal stem cells (MSCs) in culture. The results obtained indicate that HSP70 at concentrations of 2 μg/ml and higher significantly stimulates growth of aged but not young MSCs. A similar effect is produced by application of a mild heat shock (42 °C 5 min) to the cells. Importantly, responses of young and aged MSCs to heat shock treatment of various durations differed drastically, and aged MSCs were significantly more sensitive to higher heat stress exposures than the young cells. Western blotting and protein labeling experiments demonstrated that neither mild heat shock nor exogenous HSP70 administration resulted in significant endogenous HSP70 induction in young and aged MSCs, whereas mild heat shock increased HSC70 levels in aged MSCs. The results of this study suggest that the administration of exogenous HSP70 and the application of mild heat stress may produce a certain "rejuvenating" effect on MSCs and possibly other cell types in vivo, and these interventions may potentially be used for life extension by delaying various manifestations of aging at the molecular and cellular level.

Activation of Akt by Advanced Glycation End Products (AGEs): Involvement of IGF-1 Receptor and Caveolin-1

PubMed Central

Yang, Su-Jung; Chen, Chen-Yu; Chang, Geen-Dong; Wen, Hui-Chin; Chen, Ching-Yu; Chang, Shi-Chuan; Liao, Jyh-Fei; Chang, Chung-Ho

2013-01-01

Diabetes is characterized by chronic hyperglycemia, which in turn facilitates the formation of advanced glycation end products (AGEs). AGEs activate signaling proteins such as Src, Akt and ERK1/2. However, the mechanisms by which AGEs activate these kinases remain unclear. We examined the effect of AGEs on Akt activation in 3T3-L1 preadipocytes. Addition of AGEs to 3T3-L1 cells activated Akt in a dose- and time-dependent manner. The AGEs-stimulated Akt activation was blocked by a PI3-kinase inhibitor LY 294002, Src inhibitor PP2, an antioxidant NAC, superoxide scavenger Tiron, or nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase inhibitor DPI, suggesting the involvement of Src and NAD(P)H oxidase in the activation of PI3-kinase-Akt pathway by AGEs. AGEs-stimulated Src tyrosine phosphorylation was inhibited by NAC, suggesting that Src is downstream of NAD(P)H oxidase. The AGEs-stimulated Akt activity was sensitive to Insulin-like growth factor 1 receptor (IGF-1R) kinase inhibitor AG1024. Furthermore, AGEs induced phosphorylation of IGF-1 receptorβsubunit (IGF-1Rβ) on Tyr1135/1136, which was sensitive to PP2, indicating that AGEs stimulate Akt activity by transactivating IGF-1 receptor. In addition, the AGEs-stimulated Akt activation was attenuated by β-methylcyclodextrin that abolishes the structure of caveolae, and by lowering caveolin-1 (Cav-1) levels with siRNAs. Furthermore, addition of AGEs enhanced the interaction of phospho-Cav-1 with IGF-1Rβ and transfection of 3T3-L1 cells with Cav-1 Y14F mutants inhibited the activation of Akt by AGEs. These results suggest that AGEs activate NAD(P)H oxidase and Src which in turn phosphorylates IGF-1 receptor and Cav-1 leading to activation of IGF-1 receptor and the downstream Akt in 3T3-L1 cells. AGEs treatment promoted the differentiation of 3T3-L1 preadipocytes and addition of AG1024, LY 294002 or Akt inhibitor attenuated the promoting effect of AGEs on adipogenesis, suggesting that IGF-1 receptor, PI3-Kinase and Akt are involved in the facilitation of adipogenesis by AGEs. PMID:23472139

DNA damage response at telomeres contributes to lung aging and chronic obstructive pulmonary disease

PubMed Central

Birch, Jodie; Anderson, Rhys K.; Correia-Melo, Clara; Jurk, Diana; Hewitt, Graeme; Marques, Francisco Madeira; Green, Nicola J.; Moisey, Elizabeth; Birrell, Mark A.; Belvisi, Maria G.; Black, Fiona; Taylor, John J.; Fisher, Andrew J.; De Soyza, Anthony

2015-01-01

Cellular senescence has been associated with the structural and functional decline observed during physiological lung aging and in chronic obstructive pulmonary disease (COPD). Airway epithelial cells are the first line of defense in the lungs and are important to COPD pathogenesis. However, the mechanisms underlying airway epithelial cell senescence, and particularly the role of telomere dysfunction in this process, are poorly understood. We aimed to investigate telomere dysfunction in airway epithelial cells from patients with COPD, in the aging murine lung and following cigarette smoke exposure. We evaluated colocalization of γ-histone protein 2A.X and telomeres and telomere length in small airway epithelial cells from patients with COPD, during murine lung aging, and following cigarette smoke exposure in vivo and in vitro. We found that telomere-associated DNA damage foci increase in small airway epithelial cells from patients with COPD, without significant telomere shortening detected. With age, telomere-associated foci increase in small airway epithelial cells of the murine lung, which is accelerated by cigarette smoke exposure. Moreover, telomere-associated foci predict age-dependent emphysema, and late-generation Terc null mice, which harbor dysfunctional telomeres, show early-onset emphysema. We found that cigarette smoke accelerates telomere dysfunction via reactive oxygen species in vitro and may be associated with ataxia telangiectasia mutated-dependent secretion of inflammatory cytokines interleukin-6 and -8. We propose that telomeres are highly sensitive to cigarette smoke-induced damage, and telomere dysfunction may underlie decline of lung function observed during aging and in COPD. PMID:26386121

Articular Cartilage Aging-Potential Regenerative Capacities of Cell Manipulation and Stem Cell Therapy

PubMed Central

Placek, Waldemar

2018-01-01

Changes in articular cartilage during the aging process are a stage of natural changes in the human body. Old age is the major risk factor for osteoarthritis but the disease does not have to be an inevitable consequence of aging. Chondrocytes are particularly prone to developing age-related changes. Changes in articular cartilage that take place in the course of aging include the acquisition of the senescence-associated secretory phenotype by chondrocytes, a decrease in the sensitivity of chondrocytes to growth factors, a destructive effect of chronic production of reactive oxygen species and the accumulation of the glycation end products. All of these factors affect the mechanical properties of articular cartilage. A better understanding of the underlying mechanisms in the process of articular cartilage aging may help to create new therapies aimed at slowing or inhibiting age-related modifications of articular cartilage. This paper presents the causes and consequences of cellular aging of chondrocytes and the biological therapeutic outlook for the regeneration of age-related changes of articular cartilage. PMID:29470431

Performance evaluation of the Sysmex XN-1000 hematology analyzer in assessment of the white blood cell count differential in pediatric specimens.

PubMed

Becker, P-H; Fenneteau, O; Da Costa, L

2016-02-01

The automated XN-1000 hematology analyzer enables to perform a blood cell count and a leukocyte differential. When abnormal cells were detected, a flag was generated by the analyzer and a manual microscopic examination of the corresponding blood film was performed. We compared the white blood cell differentials provided by the automated hematology analyzer XN-1000 in a pediatric population (n = 765) with those obtained through microscopic examination by cytologists and those obtained using a previous version of this analyzer, the XE-2100. Leukocytes count as well as flags sensitivity and specificity was analyzed. The leukocytes count provided by the analyzer is in good accordance with the differential obtained by manual count in children older than 3 months. The sensitivity for blast detection is 99% and the detection of reactive cells is 63%. The flag specificity remains low (<35%) for blood samples collected from infants between 8 days and 2 years of age, but increases up to 67% thereafter. The results obtained with the XN-1000 analyzer show an improvement in comparison with those obtained with the XE-2100 analyzer. The automated WBC differential provided by the XN-1000 analyzer in the pediatric setting is accurate, but a meticulous microscopic examination of blood smears remains necessary for infants up to 3 months of age to validate the analyzer flags. © 2015 John Wiley & Sons Ltd.

Primary Prevention of Asthma: Age and Sex Influence Sensitivity to Allergen-Induced Airway Inflammation and Contribute to Asthma Heterogeneity in Guinea Pigs

PubMed Central

Regal, Jean F.; Regal, Ronald R.; Meehan, Jessica L.; Mohrman, Margaret E.

2010-01-01

Background Limiting allergen exposure in the sensitization phase has been proposed as a means of primary prevention of asthma, but its effectiveness is debated. Hypothesis Primary prevention of asthma is more effective in limiting asthma symptoms in young guinea pigs compared with adults, whether males or females. Methods The following experimental groups were used: young/young, sensitized and challenged before sexual maturity; young/adult, sensitized young and challenged after sexual maturity; adult/adult, sensitized and challenged after sexual maturity. Males and females were sensitized intraperitoneally with varying doses of ovalbumin (OVA) and challenged intratracheally with a constant OVA dose. Cellular infiltration into lung and lavage fluid as well as airway hyperresponsiveness to intravenous methacholine was determined 24 h later. Results In unsensitized animals, density of resident inflammatory cells as well as baseline pulmonary function differed with age and sex. Maximum OVA-induced eosinophilia in females occurred at a lower sensitizing dose of OVA than in males, and the slopes of the dose-response relationship differed significantly between sexes. Young females had more pronounced increases in eosinophils compared with some adult treatment groups. The concentrations of OVA-specific antibodies were not directly related to differences in cellular infiltration. Airway hyperresponsiveness to methacholine challenge was observed in all treatment groups. Conclusion Young animals require major reductions in allergen exposure compared with adults to effectively limit airway inflammation in primary prevention. Heterogeneity of asthma symptoms seen with age and sex suggests that primary prevention by limiting allergen exposure or treatment with anti-inflammatory or bronchodilator drugs may be more effective strategies for specific age and gender populations. PMID:16931886

Deterioration of autonomic neuronal receptor signaling and mechanisms intrinsic to heart pacemaker cells contribute to age-associated alterations in heart rate variability in vivo.

PubMed

Yaniv, Yael; Ahmet, Ismayil; Tsutsui, Kenta; Behar, Joachim; Moen, Jack M; Okamoto, Yosuke; Guiriba, Toni-Rose; Liu, Jie; Bychkov, Rostislav; Lakatta, Edward G

2016-08-01

We aimed to determine how age-associated changes in mechanisms extrinsic and intrinsic to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating intervals (BIs) were measured in aged (23-25 months) and adult (3-4 months) C57BL/6 male mice (i) via ECG in vivo during light anesthesia in the basal state, or in the presence of 0.5 mg mL(-1) atropine + 1 mg mL(-1) propranolol (in vivo intrinsic conditions), and (ii) via a surface electrogram, in intact isolated pacemaker tissue. BIV was quantified in both time and frequency domains using linear and nonlinear indices. Although the average basal BI did not significantly change with age under intrinsic conditions in vivo and in the intact isolated pacemaker tissue, the average BI was prolonged in advanced age. In vivo basal BIV indices were found to be reduced with age, but this reduction diminished in the intrinsic state. However, in pacemaker tissue BIV indices increased in advanced age vs. adults. In the isolated pacemaker tissue, the sensitivity of the average BI and BIV in response to autonomic receptor stimulation or activation of mechanisms intrinsic to pacemaker cells by broad-spectrum phosphodiesterase inhibition declined in advanced age. Thus, changes in mechanisms intrinsic to pacemaker cells increase the average BIs and BIV in the mice of advanced age. Autonomic neural input to pacemaker tissue compensates for failure of molecular intrinsic mechanisms to preserve average BI. But this compensation reduces the BIV due to both the imbalance of autonomic neural input to the pacemaker cells and altered pacemaker cell responses to neural input. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Defining age- and lactocrine-sensitive elements of the neonatal porcine uterine microRNA–mRNA interactome†,‡

PubMed Central

George, Ashley F.; Rahman, Kathleen M.; Camp, Meredith E.; Prasad, Nripesh; Bartol, Frank F.; Bagnell, Carol A.

2017-01-01

Abstract Factors delivered to offspring in colostrum within 2 days of birth support neonatal porcine uterine development. The uterine mRNA transcriptome is affected by age and nursing during this period. Whether uterine microRNA (miRNA) expression is affected similarly is unknown. Objectives were to (1) determine effects of age and nursing on porcine uterine miRNA expression between birth and postnatal day (PND) 2 using miRNA sequencing (miRNAseq) and; (2) define affected miRNA–mRNA interactions and associated biological processes using integrated target prediction analysis. At birth (PND 0), gilts were euthanized, nursed ad libitum, or gavage-fed milk replacer for 48 h. Uteri were collected at birth or 50 h postnatal. MicroRNAseq data were validated using quantitative real-time PCR. Targets were predicted using an established mRNA database generated from the same tissues. For PND 2 versus PND 0 comparisons, 31 differentially expressed (DE) miRNAs were identified for nursed, and 42 DE miRNAs were identified for replacer-fed gilts. Six DE miRNAs were identified for nursed versus replacer-fed gilts on PND 2. Target prediction for inversely correlated DE miRNA–mRNA pairings indicated 20 miRNAs targeting 251 mRNAs in nursed, versus 29 miRNAs targeting 585 mRNAs in replacer-fed gilts for PND 2 versus PND 0 comparisons, and 5 miRNAs targeting 81 mRNAs for nursed versus replacer-fed gilts on PND 2. Biological processes predicted to be affected by age and nursing included cell-to-cell signaling, cell morphology, and tissue morphology. Results indicate novel age- and lactocrine-sensitive miRNA–mRNA relationships associated with porcine neonatal uterine development between birth and PND 2. PMID:28203709

Targeting aging for disease modification in osteoarthritis.

PubMed

Collins, John A; Diekman, Brian O; Loeser, Richard F

2018-01-01

Age is a key risk factor for the development of osteoarthritis and age-related changes within the joint might represent targets for therapy. The recent literature was reviewed to find studies that provide new insight into the role of aging in osteoarthritis, with a focus on the potential for disease modification. Preclinical studies using isolated cells and animal models provide evidence that two hallmarks of aging (cellular senescence and mitochondrial dysfunction) contribute to the development of osteoarthritis. Senescent cells secrete pro-inflammatory mediators and matrix degrading enzymes, and killing these cells with 'senolytic' compounds has emerged as a potential disease-modifying therapy. Mitochondrial dysfunction is associated with increased levels of reactive oxygen species (ROS) that can promote osteoarthritis by disrupting homeostatic intracellular signaling. Reducing ROS production in the mitochondria, stimulating antioxidant gene expression through Nrf2 activation, or inhibiting specific redox-sensitive signaling proteins represent additional approaches to disease modification in osteoarthritis that require further investigation. Although no human clinical trials for osteoarthritis have specifically targeted aging, preclinical studies suggest that targeting cellular senescence and/or mitochondrial dysfunction and the effects of excessive ROS may lead to novel interventions that could slow the progression of osteoarthritis.

Prolonged Growth Hormone/Insulin/Insulin-like Growth Factor Nutrient Response Signaling Pathway as a Silent Killer of Stem Cells and a Culprit in Aging.

PubMed

Ratajczak, Mariusz Z; Bartke, Andrzej; Darzynkiewicz, Zbigniew

2017-08-01

The dream of slowing down the aging process has always inspired mankind. Since stem cells are responsible for tissue and organ rejuvenation, it is logical that we should search for encoded mechanisms affecting life span in these cells. However, in adult life the hierarchy within the stem cell compartment is still not very well defined, and evidence has accumulated that adult tissues contain rare stem cells that possess a broad trans-germ layer differentiation potential. These most-primitive stem cells-those endowed with pluripotent or multipotent differentiation ability and that give rise to other cells more restricted in differentiation, known as tissue-committed stem cells (TCSCs) - are of particular interest. In this review we present the concept supported by accumulating evidence that a population of so-called very small embryonic-like stem cells (VSELs) residing in adult tissues positively impacts the overall survival of mammals, including humans. These unique cells are prevented in vertebrates from premature depletion by decreased sensitivity to growth hormone (GH), insulin (INS), and insulin-like growth factor (IGF) signaling, due to epigenetic changes in paternally imprinted genes that regulate their resistance to these factors. In this context, we can envision nutrient response GH/INS/IGF signaling pathway as a lethal factor for these most primitive stem cells and an important culprit in aging.

SUV39H1 downregulation induces deheterochromatinization of satellite regions and senescence after exposure to ionizing radiation

PubMed Central

Sidler, Corinne; Li, Dongping; Wang, Bo; Kovalchuk, Igor; Kovalchuk, Olga

2014-01-01

While the majority of cancer patients are exposed to ionizing radiation during diagnostic and therapeutic procedures, age-dependent differences in radiation sensitivity are not yet well understood. Radiation sensitivity is characterized by the appearance of side effects to radiation therapy, such as secondary malignancies, developmental deficits, and compromised immune function. However, the knowledge of the molecular mechanisms that trigger these side effects is incomplete. Here we used an in vitro system and showed that low-senescent normal human diploid fibroblasts (WI-38) senesce in response to 5 Gy IR, while highly senescent cultures do not show changes in cell cycle regulation and only a slight increase in the percentage of senescent cells. Our study shows that this is associated with changes in the expression of genes responsible for cell cycle progression, apoptosis, DNA repair, and aging, as well as transcriptional and epigenetic regulators. Furthermore, we propose a role of the downregulation of SUV39H1 expression, a histone methyltransferase that specifically trimethylates H3K9, and the corresponding reduction in H3K9me3 levels in the establishment of IR-induced senescence. PMID:25484892

Age-Dependent Netrin-1 Signaling Regulates NG2+ Glial Cell Spatial Homeostasis in Normal Adult Gray Matter

PubMed Central

Birey, Fikri

2015-01-01

Neuron–glial antigen 2-positive (NG2+) glial cells are the most proliferative glia type in the adult CNS, and their tile-like arrangement in adult gray matter is under tight regulation. However, little is known about the cues that govern this unique distribution. To this end, using a NG2+ glial cell ablation model in mice, we examined the repopulation dynamics of NG2+ glial cells in the mature and aged mice gray matter. We found that some resident NG2+ glial cells that escaped depletion rapidly enter the cell cycle to repopulate the cortex with altered spatial distribution. We reveal that netrin-1 signaling is involved in the NG2+ glial cell early proliferative, late repopulation, and distribution response after ablation in the gray matter. However, ablation of NG2+ glial cell in older animals failed to stimulate a similar repopulation response, possibly because of a decrease in the sensitivity to netrin-1. Our findings indicate that endogenous netrin-1 plays a role in NG2+ glial cell homeostasis that is distinct from its role in myelination. PMID:25926469

Postnatal Pancreatic Islet β Cell Function and Insulin Sensitivity at Different Stages of Lifetime in Rats Born with Intrauterine Growth Retardation

PubMed Central

Liu, Cuiping; Xu, Kuanfeng; Mao, Xiaodong; Liu, Chao

2011-01-01

Epidemiological studies have linked intrauterine growth retardation (IUGR) to the metabolic diseases, consisting of insulin resistance, type 2 diabetes, obesity and coronary artery disease, during adult life. To determine the internal relationship between IUGR and islet β cell function and insulin sensitivity, we established the IUGR model by maternal nutrition restriction during mid- to late-gestation. Glucose tolerance test and insulin tolerance test(ITT) in vivo and glucose stimulated insulin secretion(GSIS) test in vitro were performed at different stages in IUGR and normal groups. Body weight, pancreas weight and pancreas/body weight of IUGR rats were much lower than those in normal group before 3 weeks of age. While the growth of IUGR rats accelerated after 3 weeks, pancreas weight and pancreas/body weight remained lower till 15 weeks of age. In the newborns, the fasting glucose and insulin levels of IUGR rats were both lower than those of controls, whereas glucose levels at 120 and 180 min after glucose load were significantly higher in IUGR group. Between 3 and 15 weeks of age, both the fasting glucose and insulin levels were elevated and the glucose tolerance was impaired with time in IUGR rats. At age 15 weeks, the area under curve of insulin(AUCi) after glucose load in IUGR rats elevated markedly. Meanwhile, the stimulating index of islets in IUGR group during GSIS test at age 15 weeks was significantly lower than that of controls. ITT showed no significant difference in two groups before 7 weeks of age. However, in 15-week-old IUGR rats, there was a markedly blunted glycemic response to insulin load compared with normal group. These findings demonstrate that IUGR rats had both impaired pancreatic development and deteriorated glucose tolerance and insulin sensitivity, which would be the internal causes why they were prone to develop type 2 diabetes. PMID:22022381

Norepinephrine Modulates Pyramidal Cell Synaptic Properties in the Anterior Piriform Cortex of Mice: Age-Dependent Effects of β-adrenoceptors

PubMed Central

Ghosh, Abhinaba; Purchase, Nicole C.; Chen, Xihua; Yuan, Qi

2015-01-01

Early odor preference learning in rodents occurs within a sensitive period [≤postnatal day (P)10–12], during which pups show a heightened ability to form an odor preference when a novel odor is paired with a tactile stimulation (e.g., stroking). Norepinephrine (NE) release from the locus coeruleus during stroking mediates this learning. However, in older pups, stroking loses its ability to induce learning. The cellular and circuitry mechanisms underpinning the sensitive period for odor preference learning is not well understood. We first established the sensitive period learning model in mice – odor paired with stroking induced odor preference in P8 but not P14 mice. This learning was dependent on NE-β-adrenoceptors as it was prevented by propranolol injection prior to training. We then tested whether there are developmental changes in pyramidal cell excitability and NE responsiveness in the anterior piriform cortex (aPC) in mouse pups. Although significant differences of pyramidal cell intrinsic properties were found in two age groups (P8–11 and P14+), NE at two concentrations (0.1 and 10 μM) did not alter intrinsic properties in either group. In contrast, in P8–11 pups, NE at 0.1 μM presynaptically decreased miniature IPSC and increased miniature EPSC frequencies. These effects were reversed with a higher dose of NE (10 μM), suggesting involvement of different adrenoceptor subtypes. In P14+ pups, NE at higher doses (1 and 10 μM) acted both pre- and postsynaptically to promote inhibition. These results suggest that enhanced synaptic excitation and reduced inhibition by NE in the aPC network may underlie the sensitive period. PMID:26635530

Insulin sensitivity and β-cell function in normoglycemic offspring of individuals with type 2 diabetes mellitus: Impact of line of inheritance.

PubMed

Praveen, Edavan P; Sahoo, Jayaprakash; Khurana, Madan L; Kulshreshtha, Bindu; Khadgawat, Rajesh; Gupta, Nandita; Dwivedi, Sada Nand; Kumar, Guresh; Prabhakaran, Dorairaj; Ammini, Ariachery C

2012-01-01

The aim was to study the effect of family history of type 2 diabetes mellitus (T2DM) on insulin sensitivity and β-cell function in normoglycemic offspring. Offspring of T2DM patients (cases) and individuals without family history of T2DM (controls) were the subjects for this cross-sectional study. All participants underwent 75 g OGTT and samples were collected for plasma insulin, C-peptide, and proinsulin at 0, 30, 60, and 120 minutes. A total of 271 cases (age 22 ± 10 years; 53% males) and 259 controls (28 ± 10 years, 66% males) were enrolled for the study. BMI, plasma insulin, C-peptide, proinsulin, HOMA-IR, and insulinogenic index (0-120) were significantly higher and whole-body insulin sensitivity (WBISI) and disposition index (0-120) [DI 120] were lower in cases compared to controls. After adjusting for BMI, proinsulin at 120 minutes, area under the curve (AUC) of proinsulin (during OGTT) and AUC proinsulin/AUC C-peptide were significantly higher in cases. Cases were subdivided into four groups according to inheritance pattern; paternal DM (PDM), maternal DM (MDM), grandparental DM (GPDM), and both parents DM (BPDM). The magnitude of differences varied with relationship (greater when both parents and grandparents were affected). Mean HOMA-IR was higher by 127% and 50% and DI 120 was lower by 33% and 18% (adjusted for age and gender) in the BPDM and GPDM groups respectively compared to controls. We observed higher BMI, plasma insulin, C-peptide, and proinsulin and lower insulin sensitivity and β-cell compensation in normoglycemic offspring of T2DM subjects compared to controls. Differences were greater when both parents and grandparents had T2DM.

Checkpoint Kinase-Dependent Regulation of DNA Repair and Genome Instability in Breast Cancer

DTIC Science & Technology

2007-06-01

cells reduces radiosensitivity. Cancer J 9:277-85. 15. Lehmann, A. R. 2003. DNA repair-deficient diseases, xeroderma pigmentosum , Cockayne syndrome...in NER give rise to the autosomal recessive disorder xeroderma pigmentosum (XP), which is characterized by ex- treme sun sensitivity, premature aging...mediated ubiquitination and deg- radation. J. Biol. Chem. 276:48175–48182. 14. Chu, G., and E. Chang. 1988. Xeroderma pigmentosum group E cells lack a

The variable role of SIRT1 in the maintenance and differentiation of mesenchymal stem cells.

PubMed

Zainabadi, Kayvan

2018-04-01

SIRT1 is an NAD + -dependent deacetylase that acts as a nutrient sensitive regulator of longevity. SIRT1 also acts as a key regulator of mesenchymal stem cells (MSCs), adult stem cells that give rise to tissues such as bone, fat, muscle and cartilage. This review focuses on how SIRT1 regulates the self-renewal, multipotency and differentiation of MSCs. The variable role of SIRT1 in promoting the differentiation of MSCs towards certain lineages, while repressing others, will be examined within the broader context of aging, calorie restriction, and regenerative medicine. Finally, recent animal and human studies will be highlighted which paint an overall salutary role for SIRT1 in protecting MSCs (and resulting tissues) from age-related atrophy and dysfunction.

Correlation of Cellular Immune Responses with Protection against Culture-Confirmed Influenza Virus in Young Children▿

PubMed Central

Forrest, Bruce D.; Pride, Michael W.; Dunning, Andrew J.; Capeding, Maria Rosario Z.; Chotpitayasunondh, Tawee; Tam, John S.; Rappaport, Ruth; Eldridge, John H.; Gruber, William C.

2008-01-01

The highly sensitive gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISPOT) assay permits the investigation of the role of cell-mediated immunity (CMI) in the protection of young children against influenza. Preliminary studies of young children confirmed that the IFN-γ ELISPOT assay was a more sensitive measure of influenza memory immune responses than serum antibody and that among seronegative children aged 6 to <36 months, an intranasal dose of 107 fluorescent focus units (FFU) of a live attenuated influenza virus vaccine (CAIV-T) elicited substantial CMI responses. A commercial inactivated influenza virus vaccine elicited CMI responses only in children with some previous exposure to related influenza viruses as determined by detectable antibody levels prevaccination. The role of CMI in actual protection against community-acquired, culture-confirmed clinical influenza by CAIV-T was investigated in a large randomized, double-blind, placebo-controlled dose-ranging efficacy trial with 2,172 children aged 6 to <36 months in the Philippines and Thailand. The estimated protection curve indicated that the majority of infants and young children with ≥100 spot-forming cells/106 peripheral blood mononuclear cells were protected against clinical influenza, establishing a possible target level of CMI for future influenza vaccine development. The ELISPOT assay for IFN-γ is a sensitive and reproducible measure of CMI and memory immune responses and contributes to establishing requirements for the future development of vaccines against influenza, especially those used for children. PMID:18448618

Phenotypic and Gene Expression Modification with Normal Brain Aging in GFAP-Positive Astrocytes and Neural Stem Cells

PubMed Central

Bernal, Giovanna M.; Peterson, Daniel A.

2011-01-01

Summary Astrocytes secrete growth factors that are both neuroprotective and supportive for the local environment. Identified by glial fibrillary acidic protein (GFAP) expression, astrocytes exhibit heterogeneity in morphology and in expression of phenotypic markers and growth factors throughout different adult brain regions. In adult neurogenic niches, astrocytes secrete vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) within the neurogenic niche, and are also a source of special GFAP-positive multipotent neural stem cells (NSCs). Normal aging is accompanied by a decline in CNS function and reduced neurogenesis. We asked if a decreased availability of astrocyte-derived factors may contribute to the age-related decline in neurogenesis. Determining alterations of astrocytic activity in the aging brain is crucial for understanding CNS homeostasis in aging and for assessing appropriate therapeutic targets for an aging population. We found region-specific alterations in gene expression of GFAP, VEGF and FGF-2 and their receptors in the aged brain corresponding to changes in astrocytic reactivity, supporting astrocytic heterogeneity and demonstrating a differential aging effect. We found that GFAP-positive NSCs uniquely coexpress both VEGF and its key mitotic receptor Flk-1 in both young and aged hippocampus, indicating a possible autocrine/paracrine signaling mechanism. VEGF expression is lost once NSCs commit to a neuronal fate, but Flk-1-mediated sensitivity to VEGF signaling is maintained. We propose that age-related astrocytic changes result in reduced VEGF and FGF-2 signaling, which in turn limits neural stem cell and progenitor cell maintenance and contributes to decreased neurogenesis. PMID:21385309

Cellular models and therapies for age-related macular degeneration

PubMed Central

Forest, David L.; Johnson, Lincoln V.; Clegg, Dennis O.

2015-01-01

ABSTRACT Age-related macular degeneration (AMD) is a complex neurodegenerative visual disorder that causes profound physical and psychosocial effects. Visual impairment in AMD is caused by the loss of retinal pigmented epithelium (RPE) cells and the light-sensitive photoreceptor cells that they support. There is currently no effective treatment for the most common form of this disease (dry AMD). A new approach to treating AMD involves the transplantation of RPE cells derived from either human embryonic or induced pluripotent stem cells. Multiple clinical trials are being initiated using a variety of cell therapies. Although many animal models are available for AMD research, most do not recapitulate all aspects of the disease, hampering progress. However, the use of cultured RPE cells in AMD research is well established and, indeed, some of the more recently described RPE-based models show promise for investigating the molecular mechanisms of AMD and for screening drug candidates. Here, we discuss innovative cell-culture models of AMD and emerging stem-cell-based therapies for the treatment of this vision-robbing disease. PMID:26035859

Kinetic approach to degradation mechanisms in polymer solar cells and their accurate lifetime predictions

NASA Astrophysics Data System (ADS)

Arshad, Muhammad Azeem; Maaroufi, AbdelKrim

2018-07-01

A beginning has been made in the present study regarding the accurate lifetime predictions of polymer solar cells. Certain reservations about the conventionally employed temperature accelerated lifetime measurements test for its unworthiness of predicting reliable lifetimes of polymer solar cells are brought into light. Critical issues concerning the accelerated lifetime testing include, assuming reaction mechanism instead of determining it, and relying solely on the temperature acceleration of a single property of material. An advanced approach comprising a set of theoretical models to estimate the accurate lifetimes of polymer solar cells is therefore suggested in order to suitably alternate the accelerated lifetime testing. This approach takes into account systematic kinetic modeling of various possible polymer degradation mechanisms under natural weathering conditions. The proposed kinetic approach is substantiated by its applications on experimental aging data-sets of polymer solar materials/solar cells including, P3HT polymer film, bulk heterojunction (MDMO-PPV:PCBM) and dye-sensitized solar cells. Based on the suggested approach, an efficacious lifetime determination formula for polymer solar cells is derived and tested on dye-sensitized solar cells. Some important merits of the proposed method are also pointed out and its prospective applications are discussed.

Generation of Transplantable Retinal Pigmented Epithelial (RPE) Cells for Treatment of Age-Related Macular Degeneration (AMD).

PubMed

Surendran, Harshini; Rathod, Reena J; Pal, Rajarshi

2018-06-13

Age-related macular degeneration (AMD) is the foremost cause of blindness in people over the age of 60 worldwide. Clinically, this disease starts with distortion in central vision eventually leading to legal blindness. Vision loss has a significant impact on quality of life and incurs a substantial cost to the economy. Furthermore, AMD is a complex and progressive neurodegenerative disorder that triggers visual impairment due to the loss of retinal pigmented epithelium (RPE) and the light-sensitive photoreceptors that they support, protect and provide nutrition. Currently, there is no curative treatment for the most common form of this disease, i.e., dry AMD. A novel approach to treat AMD involves the transplantation of RPE cells derived from human induced pluripotent stem cells (iPSCs) in the outer retina. These iPSC-derived RPE cells not only show characteristics similar to native RPE but also could replace as well as regenerate damaged pathologic RPE and produce supportive growth factors and cytokines. Several clinical trials are being conducted taking advantage of a variety of cell- and tissue engineering-based approaches. Here, we present a simple, cost effective, and scalable cell-culture model for generation of purified RPE thus providing the foundation for developing an allogeneic cell therapy for AMD.

Is Erythrocyte Protoporphyrin a Better Single Screening Test for Iron Deficiency Compared to Hemoglobin or Mean Cell Volume in Children and Women?

PubMed

Mei, Zuguo; Flores-Ayala, Rafael C; Grummer-Strawn, Laurence M; Brittenham, Gary M

2017-05-31

Hemoglobin (Hb), mean cell volume (MCV), and erythrocyte protoporphyrin (EP) are commonly used to screen for iron deficiency (ID), but systematic evaluation of the sensitivity and specificity of these tests is limited. The objective of this study is to determine the sensitivity and specificity of Hb, MCV, and EP measurements in screening for ID in preschool children, non-pregnant women 15-49 years of age, and pregnant women. Data from the National Health and Nutrition Examination Surveys (NHANES) (NHANES 2003-2006: n = 861, children three to five years of age; n = 3112, non-pregnant women 15 to 49 years of age. NHANES 1999-2006: n = 1150, pregnant women) were examined for this purpose. Children or women with blood lead ≥10 µg/dL or C-reactive protein (CRP) >5.0 mg/L were excluded. ID was defined as total body iron stores <0 mg/kg body weight, calculated from the ratio of soluble transferrin receptor (sTfR) to serum ferritin (SF). The receiver operating characteristic (ROC) curve was used to characterize the sensitivity and specificity of Hb, MCV, and EP measurements in screening for ID. In detecting ID in children three to five years of age, EP (Area under the Curve (AUC) 0.80) was superior to Hb (AUC 0.62) ( p < 0.01) but not statistically different from MCV (AUC 0.73). In women, EP and Hb were comparable (non-pregnant AUC 0.86 and 0.84, respectively; pregnant 0.77 and 0.74, respectively), and both were better than MCV (non-pregnant AUC 0.80; pregnant 0.70) ( p < 0.01). We concluded that the sensitivity and specificity of EP in screening for ID were consistently superior to or at least as effective as those of Hb and MCV in each population examined. For children three to five years of age, EP screening for ID was significantly better than Hb and similar to MCV. For both non-pregnant and pregnant women, the performance of EP and Hb were comparable; both were significantly superior to MCV.

Hormone replacement therapy diminishes hearing in peri-menopausal mice.

PubMed

Price, Katharine; Zhu, Xiaoxia; Guimaraes, Patricia F; Vasilyeva, Olga N; Frisina, Robert D

2009-06-01

We recently discovered that progestin in hormone replacement therapy (HRT) for post-menopausal women has detrimental effects on the ear and central auditory system [Guimaraes, P., Frisina, S.T., Mapes, F., Tadros, S.F., Frisina, D.R., Frisina, R.D., 2006. Progestin negatively affects hearing in aged women. Proc. Natl. Acad. Sci. - PNAS 103, 14246-14249]. To start determining the generality and neural bases of these human findings, the present study examined the effects of combination HRT (estrogen+progestin) and estrogen alone on hearing in peri-menopausal mice. Specifically, auditory brainstem responses (ABRs-sensitivity of the auditory system) and distortion-product otoacoustic emissions (DPOAEs-cochlear outer hair cell system) were employed. Middle age female CBA mice received either a time-release, subcutaneous implanted pellet of estrogen+progestin, estrogen alone, or placebo. Longitudinal comparisons of ABR threshold data obtained at 4 months of treatment revealed statistically significant declines in auditory sensitivity over time for the combined estrogen+progestin treatment group, with the estrogen only group revealing milder changes at 3, 6 and 32 kHz. DPOAE testing revealed statistically significant differences for the estrogen+progestin treatment group in the high and middle frequency ranges (15-29 and 30-45 kHz) after as early as 2 months of treatment (p<0.01 and p<0.001, respectively). Statistically significant changes were also seen at 4 months of treatment across all frequencies for the combined HRT group. These data suggest that estrogen+progestin HRT therapy of 4 months duration impairs outer hair cell functioning and overall auditory sensitivity. These findings indicate that estrogen+progestin HRT may actually accelerate age-related hearing loss, relative to estrogen monotherapy; findings that are consistent with the clinical hearing loss observed in aging women that have taken combination HRT.

Nomograms Predicting Platinum Sensitivity, Progression-Free Survival, and Overall Survival Using Pretreatment Complete Blood Cell Counts in Epithelial Ovarian Cancer

PubMed Central

Paik, E Sun; Sohn, Insuk; Baek, Sun-Young; Shim, Minhee; Choi, Hyun Jin; Kim, Tae-Joong; Choi, Chel Hun; Lee, Jeong-Won; Kim, Byoung-Gie; Lee, Yoo-Young; Bae, Duk-Soo

2017-01-01

Purpose This study was conducted to evaluate the prognostic significance of pre-treatment complete blood cell count (CBC), including white blood cell (WBC) differential, in epithelial ovarian cancer (EOC) patients with primary debulking surgery (PDS) and to develop nomograms for platinum sensitivity, progression-free survival (PFS), and overall survival (OS). Materials and Methods We retrospectively reviewed the records of 757 patients with EOC whose primary treatment consisted of surgical debulking and chemotherapy at Samsung Medical Center from 2002 to 2012. We subsequently created nomograms for platinum sensitivity, 3-year PFS, and 5-year OS as prediction models for prognostic variables including age, stage, grade, cancer antigen 125 level, residual disease after PDS, and pre-treatment WBC differential counts. The models were then validated by 10-fold cross-validation (CV). Results In addition to stage and residual disease after PDS, which are known predictors, lymphocyte and monocyte count were found to be significant prognostic factors for platinum-sensitivity, platelet count for PFS, and neutrophil count for OS on multivariate analysis. The area under the curves of platinum sensitivity, 3-year PFS, and 5-year OS calculated by the 10-fold CV procedure were 0.7405, 0.8159, and 0.815, respectively. Conclusion Prognostic factors including pre-treatment CBC were used to develop nomograms for platinum sensitivity, 3-year PFS, and 5-year OS of patients with EOC. These nomograms can be used to better estimate individual outcomes. PMID:27669704

Nomograms Predicting Platinum Sensitivity, Progression-Free Survival, and Overall Survival Using Pretreatment Complete Blood Cell Counts in Epithelial Ovarian Cancer.

PubMed

Paik, E Sun; Sohn, Insuk; Baek, Sun-Young; Shim, Minhee; Choi, Hyun Jin; Kim, Tae-Joong; Choi, Chel Hun; Lee, Jeong-Won; Kim, Byoung-Gie; Lee, Yoo-Young; Bae, Duk-Soo

2017-07-01

This study was conducted to evaluate the prognostic significance of pre-treatment complete blood cell count (CBC), including white blood cell (WBC) differential, in epithelial ovarian cancer (EOC) patients with primary debulking surgery (PDS) and to develop nomograms for platinum sensitivity, progression-free survival (PFS), and overall survival (OS). We retrospectively reviewed the records of 757 patients with EOC whose primary treatment consisted of surgical debulking and chemotherapy at Samsung Medical Center from 2002 to 2012. We subsequently created nomograms for platinum sensitivity, 3-year PFS, and 5-year OS as prediction models for prognostic variables including age, stage, grade, cancer antigen 125 level, residual disease after PDS, and pre-treatment WBC differential counts. The models were then validated by 10-fold cross-validation (CV). In addition to stage and residual disease after PDS, which are known predictors, lymphocyte and monocyte count were found to be significant prognostic factors for platinum-sensitivity, platelet count for PFS, and neutrophil count for OS on multivariate analysis. The area under the curves of platinum sensitivity, 3-year PFS, and 5-year OS calculated by the 10-fold CV procedure were 0.7405, 0.8159, and 0.815, respectively. Prognostic factors including pre-treatment CBC were used to develop nomograms for platinum sensitivity, 3-year PFS, and 5-year OS of patients with EOC. These nomograms can be used to better estimate individual outcomes.

Regionally distinct responses of microglia and glial progenitor cells to whole brain irradiation in adult and aging rats.

PubMed

Hua, Kun; Schindler, Matthew K; McQuail, Joseph A; Forbes, M Elizabeth; Riddle, David R

2012-01-01

Radiation therapy has proven efficacy for treating brain tumors and metastases. Higher doses and larger treatment fields increase the probability of eliminating neoplasms and preventing reoccurrence, but dose and field are limited by damage to normal tissues. Normal tissue injury is greatest during development and in populations of proliferating cells but also occurs in adults and older individuals and in non-proliferative cell populations. To better understand radiation-induced normal tissue injury and how it may be affected by aging, we exposed young adult, middle-aged, and old rats to 10 Gy of whole brain irradiation and assessed in gray- and white matter the responses of microglia, the primary cellular mediators of radiation-induced neuroinflammation, and oligodendrocyte precursor cells, the largest population of proliferating cells in the adult brain. We found that aging and/or irradiation caused only a few microglia to transition to the classically "activated" phenotype, e.g., enlarged cell body, few processes, and markers of phagocytosis, that is seen following more damaging neural insults. Microglial changes in response to aging and irradiation were relatively modest and three markers of reactivity - morphology, proliferation, and expression of the lysosomal marker CD68- were regulated largely independently within individual cells. Proliferation of oligodendrocyte precursors did not appear to be altered during normal aging but increased following irradiation. The impacts of irradiation and aging on both microglia and oligodendrocyte precursors were heterogeneous between white- and gray matter and among regions of gray matter, indicating that there are regional regulators of the neural response to brain irradiation. By several measures, the CA3 region of the hippocampus appeared to be differentially sensitive to effects of aging and irradiation. The changes assessed here likely contribute to injury following inflammatory challenges like brain irradiation and represent important end-points for analysis in studies of therapeutic strategies to protect patients from neural dysfunction.

Premature aging of the hippocampal neurogenic niche in adult Bmal1-deficient mice.

PubMed

Ali, Amira A H; Schwarz-Herzke, Beryl; Stahr, Anna; Prozorovski, Timour; Aktas, Orhan; von Gall, Charlotte

2015-06-01

Hippocampal neurogenesis undergoes dramatic age-related changes. Mice with targeted deletion of the clock geneBmal1 (Bmal1(-/-)) show disrupted regulation of reactive oxygen species homeostasis, accelerated aging, neurodegeneration and cognitive deficits. As proliferation of neuronal progenitor/precursor cells (NPCs) is enhanced in young Bmal1(-/-) mice, we tested the hypothesis that this results in premature aging of hippocampal neurogenic niche in adult Bmal1(-/-) mice as compared to wildtype littermates. We found significantly reduced pool of hippocampal NPCs, scattered distribution, enhanced survival of NPCs and an increased differentiation of NPCs into the astroglial lineage at the expense of the neuronal lineage. Immunoreaction of the redox sensitive histone deacetylase Sirtuine 1, peroxisomal membrane protein at 70 kDa and expression of the cell cycle inhibitor p21(Waf1/CIP1) were increased in adult Bmal1(-/-) mice. In conclusion, genetic disruption of the molecular clockwork leads to accelerated age-dependent decline in adult neurogenesis presumably as a consequence of oxidative stress.

Long-Term Stability of WC-C Peritectic Fixed Point

NASA Astrophysics Data System (ADS)

Khlevnoy, B. B.; Grigoryeva, I. A.

2015-03-01

The tungsten carbide-carbon peritectic (WC-C) melting transition is an attractive high-temperature fixed point with a temperature of . Earlier investigations showed high repeatability, small melting range, low sensitivity to impurities, and robustness of WC-C that makes it a prospective candidate for the highest fixed point of the temperature scale. This paper presents further study of the fixed point, namely the investigation of the long-term stability of the WC-C melting temperature. For this purpose, a new WC-C cell of the blackbody type was built using tungsten powder of 99.999 % purity. The stability of the cell was investigated during the cell aging for 50 h at the cell working temperature that tooks 140 melting/freezing cycles. The method of investigation was based on the comparison of the WC-C tested cell with a reference Re-C fixed-point cell that reduces an influence of the probable instability of a radiation thermometer. It was shown that after the aging period, the deviation of the WC-C cell melting temperature was with an uncertainty of.

Phenotypic and gene expression modification with normal brain aging in GFAP-positive astrocytes and neural stem cells.

PubMed

Bernal, Giovanna M; Peterson, Daniel A

2011-06-01

Astrocytes secrete growth factors that are both neuroprotective and supportive for the local environment. Identified by glial fibrillary acidic protein (GFAP) expression, astrocytes exhibit heterogeneity in morphology and in the expression of phenotypic markers and growth factors throughout different adult brain regions. In adult neurogenic niches, astrocytes secrete vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) within the neurogenic niche and are also a source of special GFAP-positive multipotent neural stem cells (NSCs). Normal aging is accompanied by a decline in CNS function and reduced neurogenesis. We asked whether a decreased availability of astrocyte-derived factors may contribute to the age-related decline in neurogenesis. Determining alterations of astrocytic activity in the aging brain is crucial for understanding CNS homeostasis in aging and for assessing appropriate therapeutic targets for an aging population. We found region-specific alterations in the gene expression of GFAP, VEGF, and FGF-2 and their receptors in the aged brain corresponding to changes in astrocytic reactivity, supporting astrocytic heterogeneity and demonstrating a differential aging effect. We found that GFAP-positive NSCs uniquely coexpress both VEGF and its key mitotic receptor Flk-1 in both young and aged hippocampus, indicating a possible autocrine/paracrine signaling mechanism. VEGF expression is lost once NSCs commit to a neuronal fate, but Flk-1-mediated sensitivity to VEGF signaling is maintained. We propose that age-related astrocytic changes result in reduced VEGF and FGF-2 signaling, which in turn limits NSC and progenitor cell maintenance and contributes to decreased neurogenesis. © 2011 The Authors. Aging Cell © 2011 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

Influence of aging in the modulation of epigenetic biomarkers of carcinogenesis after exposure to air pollution.

PubMed

Fougère, Bertrand; Landkocz, Yann; Lepers, Capucine; Martin, Perrine J; Armand, Lucie; Grossin, Nicolas; Verdin, Anthony; Boulanger, Eric; Gosset, Pierre; Sichel, François; Shirali, Pirouz; Billet, Sylvain

2018-05-31

Classified as carcinogenic to humans by the IARC in 2013, fine air particulate matter (PM 2.5 ) can be inhaled and retained into the lung or reach the systemic circulation. This can cause or exacerbate numerous pathologies to which the elderly are often more sensitive. In order to estimate the influence of age on the development of early cellular epigenetic alterations involved in carcinogenesis, peripheral blood mononuclear cells sampled from 90 patients from three age classes (25-30, 50-55 and 75-80 years old) were ex vivo exposed to urban PM 2.5 . Particles exposure led to variations in telomerase activity and telomeres length in all age groups without any influence of age. Conversely, P16 INK4A gene expression increased significantly with age after exposure to PM 2.5 . Age could enhance MGMT gene expression after exposure to particles, by decreasing the level of promoter methylation in the oldest people. Hence, our results demonstrated several tendencies in cells modification depending on age, even if all epigenetic assays were carried out after a limited exposure time allowing only one or two cell cycles. Since lung cancer symptoms appear only at an advanced stage, our results underline the needs for further investigation on the studied biomarkers for early diagnosis of carcinogenesis to improve survival. Copyright © 2018 Elsevier Inc. All rights reserved.

Aeroallergen sensitization predicts acute chest syndrome in children with sickle cell anaemia.

PubMed

Willen, Shaina M; Rodeghier, Mark; Strunk, Robert C; Bacharier, Leonard B; Rosen, Carol L; Kirkham, Fenella J; DeBaun, Michael R; Cohen, Robyn T

2018-02-01

Asthma is associated with higher rates of acute chest syndrome (ACS) and vaso-occlusive pain episodes among children with sickle cell anaemia (SCA). Aeroallergen sensitization is a risk factor for asthma. We hypothesized that aeroallergen sensitization is associated with an increased incidence of hospitalizations for ACS and pain. Participants in a multicentre, longitudinal cohort study, aged 4-18 years with SCA, underwent skin prick testing to ten aeroallergens. ACS and pain episodes were collected from birth until the end of the follow-up period. The number of positive skin tests were tested for associations with prospective rates of ACS and pain. Multivariable models demonstrated additive effects of having positive skin tests on future rates of ACS (incidence rate ratio (IRR) for each positive test 1·23, 95% confidence interval [CI] 1·11-1·36, P < 0·001). Aeroallergen sensitization was not associated with future pain (IRR 1·14, 95%CI 0·97-1·33, P = 0·11). Our study demonstrated that children with SCA and aeroallergen sensitization are at increased risk for future ACS. Future research is needed to determine whether identification of specific sensitizations and allergen avoidance and treatment reduce the risk of ACS for children with SCA. © 2018 John Wiley & Sons Ltd.

Age-Dependent Netrin-1 Signaling Regulates NG2+ Glial Cell Spatial Homeostasis in Normal Adult Gray Matter.

PubMed

Birey, Fikri; Aguirre, Adan

2015-04-29

Neuron-glial antigen 2-positive (NG2(+)) glial cells are the most proliferative glia type in the adult CNS, and their tile-like arrangement in adult gray matter is under tight regulation. However, little is known about the cues that govern this unique distribution. To this end, using a NG2(+) glial cell ablation model in mice, we examined the repopulation dynamics of NG2(+) glial cells in the mature and aged mice gray matter. We found that some resident NG2(+) glial cells that escaped depletion rapidly enter the cell cycle to repopulate the cortex with altered spatial distribution. We reveal that netrin-1 signaling is involved in the NG2(+) glial cell early proliferative, late repopulation, and distribution response after ablation in the gray matter. However, ablation of NG2(+) glial cell in older animals failed to stimulate a similar repopulation response, possibly because of a decrease in the sensitivity to netrin-1. Our findings indicate that endogenous netrin-1 plays a role in NG2(+) glial cell homeostasis that is distinct from its role in myelination. Copyright © 2015 the authors 0270-6474/15/356946-06$15.00/0.

Aging up-regulates ARA55 in stromal cells, inducing androgen-mediated prostate cancer cell proliferation and migration.

PubMed

Zou, Qingsong; Cui, Di; Liang, Shengjie; Xia, Shujie; Jing, Yifeng; Han, Bangmin

2016-06-01

Stromal cells in the peripheral zone (PZ) of the prostate from older males (PZ-old) could significantly promote Prostate cancer (PCa) growth compared with stromal cells from young males (PZ-young). But the mechanism is still unknown. In the co-culture system with PZ-old cells, Pc3/Du145 cells showed advanced proliferation and migration after Dihydrotestosterone (DHT) incubation, but DHT didn't show the similar effect in PZ-young co-culture system. Also, higher androgen/AR signal pathway activity and AR-related cytokines secretion (FGF-2, KGF, IGF-1) were found in PZ-old cells. As AR exprssison was equivalent in PZ-old and PZ-young cells, we focused on Androgen receptor associated protein-55(ARA55), a stromal-specific androgen receptor (AR) coactivator. ARA55 expression was higher in PZ-old cells compared with PZ-young cells in vitro. After knocking down ARA55 expression in PZ-old cells, the PCa growth- promoting effect from the PZ-old cells was diminished, which may be explained by the decreased the progressive cytokines secretion (FGF-2, KGF, IGF-1) from PZ-old stromal cells. In vivo, the consistent results were also found: PZ-old cells promoted prostate cancer cells growth, but this effect receded when knocking down ARA55 expression in PZ-old cells. From our study, we found PZ stromal cells presented age-related effects in proliferation and migration of prostate cancer cells in the androgen/AR dependent manner. As aging increased, more ARA55 were expressed in PZ stromal cells, leading to more sensitive androgen/androgen receptor (AR) signal pathway, then constituting a more feasible environment to cancer cells.

TRPV1 may increase the effectiveness of estrogen therapy on neuroprotection and neuroregeneration.

PubMed

Ramírez-Barrantes, Ricardo; Marchant, Ivanny; Olivero, Pablo

2016-08-01

Aging induces physical deterioration, loss of the blood brain barrier, neuronal loss-induced mental and neurodegenerative diseases. Hypotalamus-hypophysis-gonad axis aging precedes symptoms of menopause or andropause and is a major determinant of sensory and cognitive integrated function. Sexual steroids support important functions, exert pleiotropic effects in different sensory cells, promote regeneration, plasticity and health of the nervous system. Their diminution is associated with impaired cognitive and mental health and increased risk of neurodegenerative diseases. Then, restoring neuroendocrine axes during aging can be key to enhance brain health through neuroprotection and neuroregeneration, depending on the modulation of plasticity mechanisms. Estrogen-dependent transient receptor potential cation channel, subfamily V, member 1 (TRPV1) expression induces neuroprotection, neurogenesis and regeneration on damaged tissues. Agonists of TRPV1 can modulate neuroprotection and repair of sensitive neurons, while modulators as other cognitive enhancers may improve the survival rate, differentiation and integration of neural stem cell progenitors in functional neural network. Menopause constitutes a relevant clinical model of steroidal production decline associated with progressive cognitive and mental impairment, which allows exploring the effects of hormone therapy in health outcomes such as dysfunction of CNS. Simulating the administration of hormone therapy to virtual menopausal individuals allows assessing its hypothetical impact and sensitivity to conditions that modify the effectiveness and efficiency.

Inhibiting Polo-like kinase 1 causes growth reduction and apoptosis in pediatric acute lymphoblastic leukemia cells

PubMed Central

Hartsink-Segers, Stefanie A.; Exalto, Carla; Allen, Matthew; Williamson, Daniel; Clifford, Steven C.; Horstmann, Martin; Caron, Huib N.; Pieters, Rob; Den Boer, Monique L.

2013-01-01

This study investigated Polo-like kinase 1, a mitotic regulator often over-expressed in solid tumors and adult hematopoietic malignancies, as a potential new target in the treatment of pediatric acute lymphoblastic leukemia. Polo-like kinase 1 protein and Thr210 phosphorylation levels were higher in pediatric acute lymphoblastic leukemia (n=172) than in normal bone marrow mononuclear cells (n=10) (P<0.0001). High Polo-like kinase 1 protein phosphorylation, but not expression, was associated with a lower probability of event-free survival (P=0.042) and was a borderline significant prognostic factor (P=0.065) in a multivariate analysis including age and initial white blood cell count. Polo-like kinase 1 was necessary for leukemic cell survival, since short hairpin-mediated Polo-like kinase 1 knockdown in acute lymphoblastic leukemia cell lines inhibited cell proliferation by G2/M cell cycle arrest and induced apoptosis through caspase-3 and poly (ADP-ribose) polymerase cleavage. Primary patient cells with a high Polo-like kinase 1 protein expression were sensitive to the Polo-like kinase 1-specific inhibitor NMS-P937 in vitro, whereas cells with a low expression and normal bone marrow cells were resistant. This sensitivity was likely not caused by Polo-like kinase 1 mutations, since only one new mutation (Ser335Arg) was found by 454-sequencing of 38 pediatric acute lymphoblastic leukemia cases. This mutation did not affect Polo-like kinase 1 expression or NMS-P937 sensitivity. Together, these results indicate a pivotal role for Polo-like kinase 1 in pediatric acute lymphoblastic leukemia and show potential for Polo-like kinase 1-inhibiting drugs as an addition to current treatment strategies for cases expressing high Polo-like kinase 1 levels. PMID:23753023

Encapsulation materials research

NASA Technical Reports Server (NTRS)

Willis, P. B.

1984-01-01

Encapsulation materials for solar cells were investigated. The different phases consisted of: (1) identification and development of low cost module encapsulation materials; (2) materials reliability examination; and (3) process sensitivity and process development. It is found that outdoor photothermal aging devices (OPT) are the best accelerated aging methods, simulate worst case field conditions, evaluate formulation and module performance and have a possibility for life assessment. Outdoor metallic copper exposure should be avoided, self priming formulations have good storage stability, stabilizers enhance performance, and soil resistance treatment is still effective.

The effect of growth hormone treatment on metabolic and cardiovascular risk factors is similar in preterm and term short, small for gestational age children.

PubMed

de Kort, Sandra W K; Willemsen, Ruben H; van der Kaay, Danielle C M; Hokken-Koelega, Anita C S

2009-07-01

We previously reported that short, small for gestational age (SGA) children who were born preterm have a lower body fat percentage and a higher blood pressure, insulin secretion and disposition index than short SGA children born at term. Whether preterm birth also influences these parameters during GH treatment is unknown. To compare blood pressure, insulin sensitivity, beta-cell function and body composition during 4 years of GH treatment, between preterm and term short SGA children. A total of 404 prepubertal non-GH-deficient short SGA children were divided into 143 preterm (< 36 weeks) and 261 term children. Height, blood pressure (n = 404), body composition measured by dual energy X-ray absorptiometry (DXA) (n = 138) and insulin sensitivity and beta-cell function calculated from a frequent sampling intravenous glucose tolerance test (FSIGT) with tolbutamide (n = 74) or from the homeostasis model assessment of insulin resistance (HOMA-IR) (n = 204). In preterm and term children, GH treatment resulted in a similar decrease in systolic and diastolic blood pressure, body fat percentage, limb fat/total fat ratio and insulin sensitivity, and a similar increase in insulin secretion and disposition index. Lean body mass (LBM) corrected for gender and height increased in term children and did not change in preterm children. Multiple regression analysis revealed that this difference in GH effect on LBM was not associated with gestational age. The effect of GH treatment on metabolic and cardiovascular risk factors is similar in preterm and term short, SGA children.

Tif1γ regulates the TGF-β1 receptor and promotes physiological aging of hematopoietic stem cells.

PubMed

Quéré, Ronan; Saint-Paul, Laetitia; Carmignac, Virginie; Martin, Romain Z; Chrétien, Marie-Lorraine; Largeot, Anne; Hammann, Arlette; Pais de Barros, Jean-Paul; Bastie, Jean-Noël; Delva, Laurent

2014-07-22

The hematopoietic system declines with age. Myeloid-biased differentiation and increased incidence of myeloid malignancies feature aging of hematopoietic stem cells (HSCs), but the mechanisms involved remain uncertain. Here, we report that 4-mo-old mice deleted for transcription intermediary factor 1γ (Tif1γ) in HSCs developed an accelerated aging phenotype. To reinforce this result, we also show that Tif1γ is down-regulated in HSCs during aging in 20-mo-old wild-type mice. We established that Tif1γ controls TGF-β1 receptor (Tgfbr1) turnover. Compared with young HSCs, Tif1γ(-/-) and old HSCs are more sensitive to TGF-β signaling. Importantly, we identified two populations of HSCs specifically discriminated by Tgfbr1 expression level and provided evidence of the capture of myeloid-biased (Tgfbr1(hi)) and myeloid-lymphoid-balanced (Tgfbr1(lo)) HSCs. In conclusion, our data provide a new paradigm for Tif1γ in regulating the balance between lymphoid- and myeloid-derived HSCs through TGF-β signaling, leading to HSC aging.

Age-related modifications of type I collagen impair DDR1-induced apoptosis in non-invasive breast carcinoma cells.

PubMed

Charles, Saby; Hassan, Rammal; Kevin, Magnien; Emilie, Buache; Sylvie, Brassart-Pasco; Laurence, Van-Gulick; Pierre, Jeannesson; Erik, Maquoi; Hamid, Morjani

2018-05-07

Type I collagen and DDR1 axis has been described to decrease cell proliferation and to initiate apoptosis in non-invasive breast carcinoma in three-dimensional cell culture matrices. Moreover, MT1-MMP down-regulates these effects. Here, we address the effect of type I collagen aging and MT1-MMP expression on cell proliferation suppression and induced-apoptosis in non-invasive MCF-7 and ZR-75-1 breast carcinoma. We provide evidence for a decrease in cell growth and an increase in apoptosis in the presence of adult collagen when compared to old collagen. This effect involves a differential activation of DDR1, as evidenced by a higher DDR1 phosphorylation level in adult collagen. In adult collagen, inhibition of DDR1 expression and kinase function induced an increase in cell growth to a level similar to that observed in old collagen. The impact of aging on the sensitivity of collagen to MT1-MMP has been reported recently. We used the MT1-MMP expression strategy to verify whether, by degrading adult type I collagen, it could lead to the same phenotype observed in old collagen 3D matrix. MT1-MMP overexpression abrogated the proliferation suppression and induced-apoptosis effects only in the presence of adult collagen. This suggests that differential collagen degradation by MT1-MMP induced a structural disorganization of adult collagen and inhibits DDR1 activation. This could in turn impair DDR1-induced cell growth suppression and apoptosis. Taken together, our data suggest that modifications of collagen structural organization, due to aging, contribute to the loss of the growth suppression and induced apoptosis effect of collagen in luminal breast carcinoma. MT1-MMP-dependent degradation and aging of collagen have no additive effects on these processes.

Redox Signaling and Persistent Pulmonary Hypertension of the Newborn.

PubMed

Sharma, Megha; Afolayan, Adeleye J

2017-01-01

Reactive oxygen species (ROS) are redox-signaling molecules that are critically involved in regulating endothelial cell functions, host defense, aging, and cellular adaptation. Mitochondria are the major sources of ROS and important sources of redox signaling in pulmonary circulation. It is becoming increasingly evident that increased mitochondrial oxidative stress and aberrant signaling through redox-sensitive pathways play a direct causative role in the pathogenesis of many cardiopulmonary disorders including persistent pulmonary hypertension of the newborn (PPHN). This chapter highlights redox signaling in endothelial cells, antioxidant defense mechanism, cell responses to oxidative stress, and their contributions to disease pathogenesis.

Markers of inflammation, oxidative stress, and endothelial dysfunction and the 20-year cumulative incidence of early age-related macular degeneration: the Beaver Dam Eye Study.

PubMed

Klein, Ronald; Myers, Chelsea E; Cruickshanks, Karen J; Gangnon, Ronald E; Danforth, Lorraine G; Sivakumaran, Theru A; Iyengar, Sudha K; Tsai, Michael Y; Klein, Barbara E K

2014-04-01

IMPORTANCE Modifying levels of factors associated with age-related macular degeneration (AMD) may decrease the risk for visual impairment in older persons. OBJECTIVE To examine the relationships of markers of inflammation, oxidative stress, and endothelial dysfunction to the 20-year cumulative incidence of early AMD. DESIGN, SETTING, AND PARTICIPANTS This longitudinal population-based cohort study involved a random sample of 975 persons in the Beaver Dam Eye Study without signs of AMD who participated in the baseline examination in 1988-1990 and up to 4 follow-up examinations in 1993-1995, 1998-2000, 2003-2005, and 2008-2010. EXPOSURES Serum markers of inflammation (high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and white blood cell count), oxidative stress (8-isoprostane and total carbonyl content), and endothelial dysfunction (soluble vascular cell adhesion molecule-1 and soluble intercellular adhesion molecule-1) were measured. Interactions with complement factor H (rs1061170), age-related maculopathy susceptibility 2 (rs10490924), complement component 3 (rs2230199), and complement component 2/complement factor B (rs4151667) were examined using multiplicative models. Age-related macular degeneration was assessed from fundus photographs. MAIN OUTCOMES AND MEASURES Early AMD defined by the presence of any size drusen and the presence of pigmentary abnormalities or by the presence of large-sized drusen (≥125-μm diameter) in the absence of late AMD. RESULTS The 20-year cumulative incidence of early AMD was 23.0%. Adjusting for age, sex, and other risk factors, high-sensitivity C-reactive protein (odds ratio comparing fourth with first quartile, 2.18; P = .005), tumor necrosis factor-α receptor 2 (odds ratio, 1.78; P = .04), and interleukin-6 (odds ratio, 1.78; P = .03) were associated with the incidence of early AMD. Increased incidence of early AMD was associated with soluble vascular cell adhesion molecule-1 (odds ratio per SD on the logarithmic scale, 1.21; P = .04). CONCLUSIONS AND RELEVANCE We found modest evidence of relationships of serum high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and soluble vascular cell adhesion molecule-1 to the 20-year cumulative incidence of early AMD independent of age, smoking status, and other factors. It is not known whether these associations represent a cause and effect relationship or whether other unknown confounders accounted for the findings. Even if inflammatory processes are a cause of early AMD, it is not known whether interventions that reduce systemic inflammatory processes will reduce the incidence of early AMD.

Hematopoietic Cell Transplantation for Systemic Mature T-Cell Non-Hodgkin Lymphoma

PubMed Central

Smith, Sonali M.; Burns, Linda J.; van Besien, Koen; LeRademacher, Jennifer; He, Wensheng; Fenske, Timothy S.; Suzuki, Ritsuro; Hsu, Jack W.; Schouten, Harry C.; Hale, Gregory A.; Holmberg, Leona A.; Sureda, Anna; Freytes, Cesar O.; Maziarz, Richard Thomas; Inwards, David J.; Gale, Robert Peter; Gross, Thomas G.; Cairo, Mitchell S.; Costa, Luciano J.; Lazarus, Hillard M.; Wiernik, Peter H.; Maharaj, Dipnarine; Laport, Ginna G.; Montoto, Silvia; Hari, Parameswaran N.

2013-01-01

Purpose To analyze outcomes of hematopoietic cell transplantation (HCT) in T-cell non-Hodgkin lymphoma. Patients and Methods Outcomes of 241 patients (112 anaplastic large-cell lymphoma, 102 peripheral T-cell lymphoma not otherwise specified, 27 angioimmunoblastic T-cell lymphoma) undergoing autologous HCT (autoHCT; n = 115; median age, 43 years) or allogeneic HCT (alloHCT; n = 126; median age, 38 years) were analyzed. Primary outcomes were nonrelapse mortality (NRM), relapse/progression, progression-free survival (PFS), and overall survival (OS). Patient, disease, and HCT-related variables were analyzed in multivariate Cox proportional hazard models to determine association with outcomes. Results AutoHCT recipients were more likely in first complete remission (CR1; 35% v 14%; P = .001) and with chemotherapy-sensitive disease (86% v 60%; P < .001), anaplastic large-cell histology (53% v 40%; P = .04), and two or fewer lines of prior therapy (65% v 44%; P < .001) compared with alloHCT recipients. Three-year PFS and OS of autoHCT recipients beyond CR1 were 42% and 53%, respectively. Among alloHCT recipients who received transplantations beyond CR1, 31% remained progression-free at 3 years, despite being more heavily pretreated and with more refractory disease. NRM was 3.5-fold higher (95% CI, 1.80 to 6.99; P < .001) for alloHCT. In multivariate analysis, chemotherapy sensitivity (hazard ratio [HR], 1.8; 95% CI, 1.16 to 2.87) and two or fewer lines of pretransplantation therapy (HR, 5.02; 95% CI, 2.15 to 11.72) were prognostic of survival. Conclusion These data describe the roles of autoHCT and alloHCT in T-cell non-Hodgkin lymphoma and suggest greater effectiveness earlier in the disease course, and limited utility in multiply relapsed disease. Notably, autoHCT at relapse may be a potential option for select patients, particularly those with anaplastic large-cell lymphoma histology. PMID:23897963

Protective Properties of Radio-Chemoresistant Glioblastoma Stem Cell Clones Are Associated with Metabolic Adaptation to Reduced Glucose Dependence

PubMed Central

Yamada, Kazunari; Tso, Jonathan L.; Menjivar, Jimmy C.; Tian, Jane Y.; Yong, William H.; Schaue, Dörthe; Mischel, Paul S.; Cloughesy, Timothy F.; Nelson, Stanley F.; Liau, Linda M.; McBride, William; Tso, Cho-Lea

2013-01-01

Glioblastoma stem cells (GSC) are a significant cell model for explaining brain tumor recurrence. However, mechanisms underlying their radiochemoresistance remain obscure. Here we show that most clonogenic cells in GSC cultures are sensitive to radiation treatment (RT) with or without temozolomide (TMZ). Only a few single cells survive treatment and regain their self-repopulating capacity. Cells re-populated from treatment-resistant GSC clones contain more clonogenic cells compared to those grown from treatment-sensitive GSC clones, and repeated treatment cycles rapidly enriched clonogenic survival. When compared to sensitive clones, resistant clones exhibited slower tumor development in animals. Upregulated genes identified in resistant clones via comparative expression microarray analysis characterized cells under metabolic stress, including blocked glucose uptake, impaired insulin/Akt signaling, enhanced lipid catabolism and oxidative stress, and suppressed growth and inflammation. Moreover, many upregulated genes highlighted maintenance and repair activities, including detoxifying lipid peroxidation products, activating lysosomal autophagy/ubiquitin-proteasome pathways, and enhancing telomere maintenance and DNA repair, closely resembling the anti-aging effects of caloric/glucose restriction (CR/GR), a nutritional intervention that is known to increase lifespan and stress resistance in model organisms. Although treatment–introduced genetic mutations were detected in resistant clones, all resistant and sensitive clones were subclassified to either proneural (PN) or mesenchymal (MES) glioblastoma subtype based on their expression profiles. Functional assays demonstrated the association of treatment resistance with energy stress, including reduced glucose uptake, fatty acid oxidation (FAO)-dependent ATP maintenance, elevated reactive oxygen species (ROS) production and autophagic activity, and increased AMPK activity and NAD+ levels accompanied by upregulated mRNA levels of SIRT1/PGC-1α axis and DNA repair genes. These data support the view that treatment resistance may arise from quiescent GSC exhibiting a GR-like phenotype, and suggest that targeting stress response pathways of resistant GSC may provide a novel strategy in combination with standard treatment for glioblastoma. PMID:24260384

THE EFFECT OF POLIOMYELITIS VIRUS ON HUMAN BRAIN CELLS IN TISSUE CULTURE

PubMed Central

Hogue, M. J.; McAllister, R.; Greene, A. E.; Coriell, L. L.

1955-01-01

Poliomyelitis virus I, Mahoney strain, affected human brain cells grown in tissue cultures usually causing death of the cells in 3 days. The neurons reacted in different ways to the virus, some died with their neurites extended, others contracted one or more of their neurites. Terminal bulbs were frequently formed at the tips of the neurites when they were being drawn into the cell body. The final contraction of the cell body and the change into a mass of granules were often very sudden. Vacuoles often developed in the neuron. There was no recovery. Astrocytes, oligodendroglia, and macrophages were affected by the virus but not as quickly as the neurons. The age of the tissue culture was not a factor when the cells were in good condition. The age of the individual donor of the brain tissue was a factor; the fetal brain cells appeared to be more sensitive to the virus than the adult brain cells. The fetal neurons often reacted ½ hour after inoculation while the adult neurons reacted more slowly, 2 to 24 hours after inoculation. All these changes seemed to be caused by virus infection because they were prevented by specific antiserum or by preheating the virus. PMID:14392238

Collapsing Aged Culture of the Cyanobacterium Synechococcus elongatus Produces Compound(s) Toxic to Photosynthetic Organisms

PubMed Central

Cohen, Assaf; Sendersky, Eleonora; Carmeli, Shmuel; Schwarz, Rakefet

2014-01-01

Phytoplankton mortality allows effective nutrient cycling, and thus plays a pivotal role in driving biogeochemical cycles. A growing body of literature demonstrates the involvement of regulated death programs in the abrupt collapse of phytoplankton populations, and particularly implicates processes that exhibit characteristics of metazoan programmed cell death. Here, we report that the cell-free, extracellular fluid (conditioned medium) of a collapsing aged culture of the cyanobacterium Synechococcus elongatus is toxic to exponentially growing cells of this cyanobacterium, as well as to a large variety of photosynthetic organisms, but not to eubacteria. The toxic effect, which is light-dependent, involves oxidative stress, as suggested by damage alleviation by antioxidants, and the very high sensitivity of a catalase-mutant to the conditioned medium. At relatively high cell densities, S. elongatus cells survived the deleterious effect of conditioned medium in a process that required de novo protein synthesis. Application of conditioned medium from a collapsing culture caused severe pigment bleaching not only in S. elongatus cells, but also resulted in bleaching of pigments in a cell free extract. The latter observation indicates that the elicited damage is a direct effect that does not require an intact cell, and therefore, is mechanistically different from the metazoan-like programmed cell death described for phytoplankton. We suggest that S. elongatus in aged cultures are triggered to produce a toxic compound, and thus, this process may be envisaged as a novel regulated death program. PMID:24959874

GABAergic miniature postsynaptic currents in septal neurons show differential allosteric sensitivity after binge-like ethanol exposure.

PubMed

DuBois, Dustin W; Trzeciakowski, Jerome P; Parrish, Alan R; Frye, Gerald D

2006-05-17

Binge-like ethanol treatment of septal neurons blunts GABAAR-mediated miniature postsynaptic currents (mPSCs), suggesting it arrests synaptic development. Ethanol may disrupt postsynaptic maturation by blunting feedback signaling through immature GABAARs. Here, the impact of ethanol on the sensitivity of mPSCs to zolpidem, zinc and 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha-OH-DHP) was tested. The decay phase of mPSCs showed concentration-dependent potentiation by zolpidem (0.03-100 microM), which was substantially blunted after ethanol exposure. Since zolpidem potentiation exhibited a substantial age-dependent increase in untreated neurons, this finding supported the idea that ethanol arrests synaptic development. GABAAR alpha1 subunit protein also increased with age in untreated neurons, paralleling enhanced sensitivity to zolpidem. Surprisingly, alpha1 levels were not reduced by binge ethanol even though mPSCs were relatively zolpidem-insensitive. Zinc (3-30 microM) decreased mPSC parameters in a concentration- and age-related manner with older untreated cells showing less inhibition. However, there was no increase in mPSC zinc sensitivity after binge ethanol as would be expected if a general arrest of synaptic maturation had occurred. 3alpha-OH-DHP (3-1000 nM) induced concentration-dependent potentiation of mPSC decay. Although potentiation was age-independent, binge ethanol treatment exaggerated sensitivity to this neurosteroid. Finally, chronic picrotoxin pretreatment (100 microM) intended to mimic GABAAR inhibition from ethanol pretreatment did not significantly change mPSC modulation by zolpidem, zinc or 3alpha-OH-DHP. These results suggest that binge ethanol treatment selectively arrests a subset of processes important for maturation of postsynaptic GABAA Rs. However, it is unlikely that ethanol causes a broad arrest of postsynaptic development through a direct inhibition of GABAAR signaling.

Fisetin and luteolin protect human retinal pigment epithelial cells from oxidative stress-induced cell death and regulate inflammation

PubMed Central

Hytti, Maria; Piippo, Niina; Korhonen, Eveliina; Honkakoski, Paavo; Kaarniranta, Kai; Kauppinen, Anu

2015-01-01

Degeneration of retinal pigment epithelial (RPE) cells is a clinical hallmark of age-related macular degeneration (AMD), the leading cause of blindness among aged people in the Western world. Both inflammation and oxidative stress are known to play vital roles in the development of this disease. Here, we assess the ability of fisetin and luteolin, to protect ARPE-19 cells from oxidative stress-induced cell death and to decrease intracellular inflammation. We also compare the growth and reactivity of human ARPE-19 cells in serum-free and serum-containing conditions. The absence of serum in the culture medium did not prevent ARPE-19 cells from reaching full confluency but caused an increased sensitivity to oxidative stress-induced cell death. Both fisetin and luteolin protected ARPE-19 cells from oxidative stress-induced cell death. They also significantly decreased the release of pro-inflammatory cytokines into the culture medium. The decrease in inflammation was associated with reduced activation of MAPKs and CREB, but was not linked to NF- κB or SIRT1. The ability of fisetin and luteolin to protect and repair stressed RPE cells even after the oxidative insult make them attractive in the search for treatments for AMD. PMID:26619957

Role of interleukins, IGF and stem cells in BPH

PubMed Central

McLaren, Ian D.; Jerde, Travis J.; Bushman, Wade

2013-01-01

The condition known as benign prostatic hyperplasia may be defined as a benign enlargement of the prostate gland resulting from a proliferation of both benign epithelial and stromal elements. It might also be defined clinically as a constellation of lower urinary tract symptoms (LUTSs) in aging men. The purpose of this review is to consider the ways in which inflammatory cytokines belonging to the interleukin family, members of the IFG family, and stem cells may contribute to the development and progression of BPH-LUTS. This might occur in three mechanisms: One, interleukin signaling, IFG signaling and stem cells may contribute to reactivation of developmental growth mechanisms in the adult prostate leading to tissue growth. Two, given that epidemiologic studies indicate an increased incidence of BPH-LUTS in association with obesity and diabetes, IFG signaling may provide the mechanistic basis for the effect of diabetes and obesity on prostate growth. Three, expression of interleukins in association with inflammation in the prostate may induce sensitization of afferent fibers innervating the prostate and result in increased sensitivity to pain and noxious sensations in the prostate and bladder and heightened sensitivity to bladder filling. PMID:21864972

Maillard reaction products enriched food extract reduce the expression of myofibroblast phenotype markers.

PubMed

Ruhs, Stefanie; Nass, Norbert; Somoza, Veronika; Friess, Ulrich; Schinzel, Reinhard; Silber, Rolf-Edgar; Simm, Andreas

2007-04-01

Advanced glycation end products (AGE) are associated with a wide range of degenerative diseases. The present investigation aimed at analysing the influence of AGE containing nutritional extracts on cardiac fibroblasts (CFs) as the major cell type responsible for cardiac fibrosis. Mice CFs were treated with bread crust extract (BCE) which contained significant amounts of a variety of AGE modifications. BCE treatment with up to 30 mg/mL did not impair cell viability. Furthermore, BCE induced a moderate elevation of reactive oxygen species (ROS) production and activation of redox sensitive pathways like the p42/44(MAPK), p38(MAPK) and NF-kappaB but did not alter Akt kinase phosphorylation. Expression of smooth muscle alpha-actin and tropomyosin-1, which represent markers for myofibroblast differentiation, was reduced after bread crust treatment. These data suggest a putative antifibrotic effect of melanoidin-rich food.

Changes in glycolytic enzyme activities in aging erythrocytes fractionated by counter-current distribution in aqueous polymer two-phase systems.

PubMed Central

Jimeno, P; Garcia-Perez, A I; Luque, J; Pinilla, M

1991-01-01

Human and rat erythrocytes were fractionated by counter-current distribution in charge-sensitive dextran/poly(ethylene glycol) two-phase systems. The specific activities of the key glycolytic enzymes (hexokinase, phosphofructokinase and pyruvate kinase) declined along the distribution profiles, although the relative positions of the activity profiles were reversed in the two species. These enzymes maintained their normal response to specific regulatory effectors in all cell fractions. No variations were observed for phosphoglycerate kinase and bisphosphoglycerate mutase activities. Some correlations between enzyme activities (pyruvate kinase/hexokinase, pyruvate kinase/phosphofructokinase, pyruvate kinase/pyruvate kinase plus phosphoglycerate kinase, pyruvate kinase/bisphosphoglycerate mutase and phosphoglycerate kinase/bisphosphoglycerate mutase ratios) were studied in whole erythrocyte populations as well as in cell fractions. These results strongly support the fractionation of human erythrocytes according to cell age, as occurs with rat erythrocytes. PMID:1656939

The ΔF508 Mutation in the Cystic Fibrosis Transmembrane Conductance Regulator Is Associated With Progressive Insulin Resistance and Decreased Functional β-Cell Mass in Mice.

PubMed

Fontés, Ghislaine; Ghislain, Julien; Benterki, Isma; Zarrouki, Bader; Trudel, Dominique; Berthiaume, Yves; Poitout, Vincent

2015-12-01

Cystic fibrosis (CF) is the result of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). CF-related diabetes affects 50% of adult CF patients. How CFTR deficiency predisposes to diabetes is unknown. Herein, we examined the impact of the most frequent cftr mutation in humans, deletion of phenylalanine at position 508 (ΔF508), on glucose homeostasis in mice. We compared ΔF508 mutant mice with wild-type (WT) littermates. Twelve-week-old male ΔF508 mutants had lower body weight, improved oral glucose tolerance, and a trend toward higher insulin tolerance. Glucose-induced insulin secretion was slightly diminished in ΔF508 mutant islets, due to reduced insulin content, but ΔF508 mutant islets were not more sensitive to proinflammatory cytokines than WT islets. Hyperglycemic clamps confirmed an increase in insulin sensitivity with normal β-cell function in 12- and 18-week-old ΔF508 mutants. In contrast, 24-week-old ΔF508 mutants exhibited insulin resistance and reduced β-cell function. β-Cell mass was unaffected at 11 weeks of age but was significantly lower in ΔF508 mutants versus controls at 24 weeks. This was not associated with gross pancreatic pathology. We conclude that the ΔF508 CFTR mutation does not lead to an intrinsic β-cell secretory defect but is associated with insulin resistance and a β-cell mass deficit in aging mutants. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Aging of mice is associated with p16(Ink4a)- and β-galactosidase-positive macrophage accumulation that can be induced in young mice by senescent cells

PubMed Central

Hall, Brandon M.; Balan, Vitaly; Gleiberman, Anatoli S.; Strom, Evguenia; Krasnov, Peter; Virtuoso, Lauren P.; Rydkina, Elena; Vujcic, Slavoljub; Balan, Karina; Gitlin, Ilya; Leonova, Katerina; Polinsky, Alexander; Chernova, Olga B.; Gudkov, Andrei V.

2016-01-01

Senescent cells (SCs) have been considered a source of age-related chronic sterile systemic inflammation and a target for anti-aging therapies. To understand mechanisms controlling the amount of SCs, we analyzed the phenomenon of rapid clearance of human senescent fibroblasts implanted into SCID mice, which can be overcome when SCs were embedded into alginate beads preventing them from immunocyte attack. To identify putative SC killers, we analyzed the content of cell populations in lavage and capsules formed around the SC-containing beads. One of the major cell types attracted by secretory factors of SCs was a subpopulation of macrophages characterized by p16(Ink4a) gene expression and β-galactosidase activity at pH6.0 (β-galpH6), thus resembling SCs. Consistently, mice with p16(Ink4a) promoter-driven luciferase, developed bright luminescence of their peritoneal cavity within two weeks following implantation of SCs embedded in alginate beads. p16(Ink4a)/β-galpH6-expressing cells had surface biomarkers of macrophages F4/80 and were sensitive to liposomal clodronate used for the selective killing of cells capable of phagocytosis. At the same time, clodronate failed to kill bona fide SCs generated in vitro by genotoxic stress. Old mice with elevated proportion of p16(Ink4a)/β-galpH6-positive cells in their tissues demonstrated reduction of both following systemic clodronate treatment, indicating that a significant proportion of cells previously considered to be SCs are actually a subclass of macrophages. These observations point at a significant role of p16(Ink4a)/β-galpH6-positive macrophages in aging, which previously was attributed solely to SCs. They require re-interpretation of the mechanisms underlying rejuvenating effects following eradication of p16(Ink4a)/β-galpH6-positive cells and reconsideration of potential cellular target for anti-aging treatment. PMID:27391570

Na and K Dependence of the Na/K Pump in Cystic Fibrosis Fibroblasts

NASA Astrophysics Data System (ADS)

Reznik, Vivian M.; Schneider, Jerry A.; Mendoza, Stanley A.

1981-11-01

The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fibrosis, the Na/K pump had a significantly lower affinity for K (Km = 1.6 mM) when compared to normals (Km = 0.9 mM). This difference was demonstrated by using two independent experimental designs.

Early decrease of insulin sensitivity in offspring of individuals with type 2 diabetes. The Mexican Diabetes Prevention Study.

PubMed

Pérez-Fuentes, Ricardo; Baez-Duarte, Blanca G; Zamora-Ginez, Irma; Ruiz-Vivanco, Guadalupe; Pulido-Pérez, Patricia; Nieva-Vázquez, Adriana; Gonzalez-Mejia, M Elba; Torres-Rasgado, Enrique

2014-04-01

Defects in insulin sensitivity (IS) and insulin secretion have been recognized as risk factors for type 2 diabetes (T2D) and its complications. We undertook this study to establish the relationship between healthy type 2 diabetic offspring (OFD) from a Mexican population with IS. A total of 602 Mexican subjects, 359 first-degree offspring of T2D (OFD+) and 243 first-degree non-offspring of T2D (OFD-) were classified as young adults (age range, 18-44 years) and middle-aged adults (age range, 45-65 years). Groups were clinically and biochemically characterized. Quantitative insulin sensitivity check index (QUICKI) was used to estimate IS and the homeostasis model assessment B (HOMA-B) was used to estimate B cell function. IS decreased significantly (p <0.05) in OFD+ middle-aged (QUICKI 0.330 ± 0.03) compared with OFD- (0. 370 ± 0.03). Middle-aged adults (OFD+) had the highest prevalence of increased fasting insulin levels (FIL) (13.6%) and decreased IS (22.9%) compared with OFD- groups (3.2%). A binary regression analysis showed the association of OFD+ with increased FIL (odds ratio [OR], 3.71; 95% confidence interval [95% CI], 1.68-8.2; p = 0.001), and QUICKI (OR, 10.87; 95% CI, 2.36-44.69; p <0.01) adjusted by gender, age, and obesity. Our results suggest that decreased IS itself could be recognized as one of the earliest detectable abnormalities in middle-aged adults. Moreover, prevalence increases with age and is associated with type 2 diabetic offspring, regardless of obesity. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

Biorevitalizing effect of a novel facial serum containing apple stem cell extract, pro-collagen lipopeptide, creatine, and urea on skin aging signs.

PubMed

Sanz, Maria Teresa; Campos, Celia; Milani, Massimo; Foyaca, Monica; Lamy, Amandine; Kurdian, Karine; Trullas, Carles

2016-03-01

Epithelial regeneration in skin is achieved by the constant turnover and differentiation of keratinocytes. Epidermal and dermal stem cells compartments are fundamental for the continuous renewal of the skin. Adult stem cells are the unique source for skin tissue renewal. Plants have stem cells and plant derived stem cell extracts are now used in topical products for their potential anti-ageing and anti-wrinkle effects. A new dermocosmetic product containing apple stem cell extract, urea, creatine and palmitoyl tripeptide-38 (Ureadin Fusion Serum Lift Antiarrugas, ISDIN S.A), has been recently developed to target different aspects involved in skin aging. To assess in vitro the effects of this new serum on the metabolic functions of human senescent fibroblasts and in vivo the anti-aging effects by clinical and instrumental evaluation. We evaluated the effects of the serum on the mitochondrial ROS (reactive oxygen species) production in human senescent cultured fibroblasts measured at 0.1% and 1% using the Mitoread AntiOx mtROS method. In addition we evaluated the anti-ageing in vivo effect of this new serum applied on the face twice daily for 28 consecutive days and assessed by clinical and instrumental evaluation in 32 women with sensitive skin bearing wrinkles on crow's feet. The tested serum both at 0.1% and 1% induces a significant increase in 02 consumption, cellular ATP level and a reduction in extra-cellular lactate concentration. The product reduces also significantly the mitochondrial ROS production. The clinical study shows a relevant anti-wrinkle effect in 71% of the treated women with visible effects in 68% of the subjects as soon as 7 days of treatment. A significant increase in dermal density and skin elasticity was also observed. The use of this novel anti-aging serum demonstrated a significant improvement of aging skin signs with first visible results achieved after one week of use. The product seemed to optimize the metabolic functions in human senescent cultured fibroblast restoring a more efficient cell metabolism therefore contributing to the anti-aging properties of the product. © 2015 The Authors. Journal of Cosmetic Dermatology Published by Wiley Periodicals, Inc.

Dose-dependent effects of 6-hydroxy dopamine on deprivation myopia, electroretinograms, and dopaminergic amacrine cells in chickens.

PubMed

Li, X X; Schaeffel, F; Kohler, K; Zrenner, E

1992-11-01

We found that a single intravitreal injection of 6-hydroxy dopamine (6-OHDA) is highly efficient in blocking the development of deprivation-induced myopia in young chickens. To investigate the effects of 6-OHDA on retinal function, we studied electroretinograms (ERGs) in chickens aged 15-25 days, 4 days subsequent to the injection. Both spectral sensitivity and oscillatory potentials were tested. In addition, a histological examination was performed of dopaminergic amacrine cells labeled by a monoclonal antibody against tyrosine hydroxylase. We found that, at doses of 6-OHDA sufficient to suppress deprivation myopia entirely, no effect could be detected on either the ERGs or on the density and appearance of dopaminergic amacrine cells. For higher doses, spectral sensitivity and the number of dopaminergic amacrine cells declined gradually. In contrast, as doses increased, oscillatory potentials 1 and 2 grew in amplitude only to decline at the highest doses. The results indicate that (1) development of deprivation myopia requires normal retinal function and that (2) slight changes in the gains of dopaminergic pathways are sufficient to block the development of deprivation myopia.

Validation of World Health Organisation HIV/AIDS clinical staging in predicting initiation of antiretroviral therapy and clinical predictors of low CD4 cell count in Uganda.

PubMed

Baveewo, Steven; Ssali, Francis; Karamagi, Charles; Kalyango, Joan N; Hahn, Judith A; Ekoru, Kenneth; Mugyenyi, Peter; Katabira, Elly

2011-05-12

The WHO clinical guidelines for HIV/AIDS are widely used in resource limited settings to represent the gold standard of CD4 counts for antiviral therapy initiation. The utility of the WHO-defined stage 1 and 2 clinical factors used in WHO HIV/AIDS clinical staging in predicting low CD4 cell count has not been established in Uganda. Although the WHO staging has shown low sensitivity for predicting CD4<200 cells/mm(3), it has not been evaluated at for CD4 cut-offs of <250 cells/mm(3) or <350 cells/mm(3). To validate the World Health Organisation HIV/AIDS clinical staging in predicting initiation of antiretroviral therapy in a low-resource setting and to determine the clinical predictors of low CD4 cell count in Uganda. Data was collected on 395 participants from the Joint Clinical Research Centre, of whom 242 (61.3%) were classified as in stages 1 and 2 and 262 (68%) were females. Participants had a mean age of 36.8 years (SD 8.5). We found a significant inverse correlation between the CD4 lymphocyte count and WHO clinical stages. The sensitivity the WHO clinical staging at CD4 cell count of 250 cells/mm(3) and 350 cells/mm(3) was 53.5% and 49.1% respectively. Angular cheilitis, papular pruritic eruptions and recurrent upper respiratory tract infections were found to be significant predictors of low CD4 cell count among participants in WHO stage 1 and 2. The WHO HIV/AIDS clinical staging guidelines have a low sensitivity and about half of the participants in stages 1 and 2 would be eligible for ART initiation if they had been tested for CD4 count. Angular cheilitis and papular pruritic eruptions and recurrent upper respiratory tract infections may be used, in addition to the WHO staging, to improve sensitivity in the interim, as access to CD4 machines increases in Uganda.

Aerobic Exercise Training Attenuates Tumor Growth and Reduces Insulin Secretion in Walker 256 Tumor-Bearing Rats

PubMed Central

Moreira, Veridiana Mota; da Silva Franco, Claudinéia Conationi; Prates, Kelly Valério; Gomes, Rodrigo Mello; de Moraes, Ana Maria Praxedes; Ribeiro, Tatiane Aparecida; Martins, Isabela Peixoto; Previate, Carina; Pavanello, Audrei; Matiusso, Camila Cristina Ianoni; Almeida, Douglas Lopes; Francisco, Flávio Andrade; Malta, Ananda; Tófolo, Laize Peron; da Silva Silveira, Sandra; Saavedra, Lucas Paulo Jacinto; Machado, Katia; da Silva, Paulo Henrique Olivieri; Fabrício, Gabriel S.; Palma-Rigo, Kesia; de Souza, Helenir Medri; de Fátima Silva, Flaviane; Biazi, Giuliana Regina; Pereira, Taís Susane; Vieira, Elaine; Miranda, Rosiane Aparecida; de Oliveira, Júlio Cezar; da Costa Lima, Luiz Delmar; Rinaldi, Wilson; Ravanelli, Maria Ida; de Freitas Mathias, Paulo Cezar

2018-01-01

Aerobic exercise training can improve insulin sensitivity in many tissues; however, the relationship among exercise, insulin, and cancer cell growth is unclear. We tested the hypothesis that aerobic exercise training begun during adolescence can attenuate Walker 256 tumor growth in adult rats and alter insulin secretion. Thirty-day-old male Wistar rats engaged in treadmill running for 8 weeks, 3 days/week, 44 min/day, at 55–65% VO2max until they were 90 days old (TC, Trained Control). An equivalently aged group was kept inactive during the same period (SC, Sedentary Control). Then, half the animals of the SC and TC groups were reserved as the control condition and the other half were inoculated with Walker 256 cancer cells, yielding two additional groups (Sedentary Walker and Trained Walker). Zero mortalities were observed in tumor-bearing rats. Body weight (BW), food intake, plasma glucose, insulin levels, and peripheral insulin sensitivity were analyzed before and after tumor cell inoculation. We also evaluated tumor growth, metastasis and cachexia. Isolated pancreatic islets secretory activity was analyzed. In addition, we evaluated mechanic sensibility. Our results showed improved physical performance according to the final workload and VO2max and reduced BW in trained rats at the end of the running protocol. Chronic adaptation to the aerobic exercise training decreased tumor weight, cachexia and metastasis and were associated with low glucose and insulin levels and high insulin sensitivity before and after tumor cell inoculation. Aerobic exercise started at young age also reduced pancreatic islet insulin content and insulin secretion in response to a glucose stimulus, without impairing islet morphology in trained rats. Walker 256 tumor-bearing sedentary rats also presented reduced pancreatic islet insulin content, without changing insulin secretion through isolated pancreatic islets. The mechanical sensitivity test indicated that aerobic exercise training did not cause injury or trigger inflammatory processes prior to tumor cell inoculation. Taken together, the current study suggests that aerobic exercise training applied during adolescence may mitigate tumor growth and related disorders in Walker 256 tumor-bearing adult rats. Improved insulin sensibility, lower glucose and insulin levels and/or reduced insulin secretion stimulated by glucose may be implicated in this tumor attenuation.

Aerobic Exercise Training Attenuates Tumor Growth and Reduces Insulin Secretion in Walker 256 Tumor-Bearing Rats.

PubMed

Moreira, Veridiana Mota; da Silva Franco, Claudinéia Conationi; Prates, Kelly Valério; Gomes, Rodrigo Mello; de Moraes, Ana Maria Praxedes; Ribeiro, Tatiane Aparecida; Martins, Isabela Peixoto; Previate, Carina; Pavanello, Audrei; Matiusso, Camila Cristina Ianoni; Almeida, Douglas Lopes; Francisco, Flávio Andrade; Malta, Ananda; Tófolo, Laize Peron; da Silva Silveira, Sandra; Saavedra, Lucas Paulo Jacinto; Machado, Katia; da Silva, Paulo Henrique Olivieri; Fabrício, Gabriel S; Palma-Rigo, Kesia; de Souza, Helenir Medri; de Fátima Silva, Flaviane; Biazi, Giuliana Regina; Pereira, Taís Susane; Vieira, Elaine; Miranda, Rosiane Aparecida; de Oliveira, Júlio Cezar; da Costa Lima, Luiz Delmar; Rinaldi, Wilson; Ravanelli, Maria Ida; de Freitas Mathias, Paulo Cezar

2018-01-01

Aerobic exercise training can improve insulin sensitivity in many tissues; however, the relationship among exercise, insulin, and cancer cell growth is unclear. We tested the hypothesis that aerobic exercise training begun during adolescence can attenuate Walker 256 tumor growth in adult rats and alter insulin secretion. Thirty-day-old male Wistar rats engaged in treadmill running for 8 weeks, 3 days/week, 44 min/day, at 55-65% VO 2max until they were 90 days old (TC, Trained Control). An equivalently aged group was kept inactive during the same period (SC, Sedentary Control). Then, half the animals of the SC and TC groups were reserved as the control condition and the other half were inoculated with Walker 256 cancer cells, yielding two additional groups (Sedentary Walker and Trained Walker). Zero mortalities were observed in tumor-bearing rats. Body weight (BW), food intake, plasma glucose, insulin levels, and peripheral insulin sensitivity were analyzed before and after tumor cell inoculation. We also evaluated tumor growth, metastasis and cachexia. Isolated pancreatic islets secretory activity was analyzed. In addition, we evaluated mechanic sensibility. Our results showed improved physical performance according to the final workload and VO 2max and reduced BW in trained rats at the end of the running protocol. Chronic adaptation to the aerobic exercise training decreased tumor weight, cachexia and metastasis and were associated with low glucose and insulin levels and high insulin sensitivity before and after tumor cell inoculation. Aerobic exercise started at young age also reduced pancreatic islet insulin content and insulin secretion in response to a glucose stimulus, without impairing islet morphology in trained rats. Walker 256 tumor-bearing sedentary rats also presented reduced pancreatic islet insulin content, without changing insulin secretion through isolated pancreatic islets. The mechanical sensitivity test indicated that aerobic exercise training did not cause injury or trigger inflammatory processes prior to tumor cell inoculation. Taken together, the current study suggests that aerobic exercise training applied during adolescence may mitigate tumor growth and related disorders in Walker 256 tumor-bearing adult rats. Improved insulin sensibility, lower glucose and insulin levels and/or reduced insulin secretion stimulated by glucose may be implicated in this tumor attenuation.

Cytokine Profile of Patients with Allergic Rhinitis Caused by Pollen, Mite, and Microbial Allergen Sensitization.

PubMed

Tyurin, Yury A; Lissovskaya, Svetlana A; Fassahov, Rustem S; Mustafin, Ilshat G; Shamsutdinov, Anton F; Shilova, Marina A; Rizvanov, Albert A

2017-01-01

Allergic rhinitis (AR) is especially prevalent among the population of large cities. Immunologically, the airway epithelium is a region where the population of allergen-presenting cells concentrates. These cells actively express a group of receptors of the innate immune system. A specific cytokine profile is its representation. The study was aimed at evaluating the cytokine profile in patients with seasonal and perennial allergic rhinitis. The cytokine profile of nasal secretion and blood serum of 44 patients with AR was studied. 24 of them had seasonal allergic rhinitis (SAR), and 20 patients suffered from perennial allergic rhinitis (PAR). The patients' age ranged from 4 to 60 years. It was determined in our study that the activation of the GM-CSF production retained in patients with PAR sensitized to mite allergen components ( Dermatophagoides pteronyssinus ). There was a higher production profile of TNF- α and TSLP in nasal secretion in the patients with perennial allergic rhinitis and additional high sensitization to SEs. Sensitization to mold fungal allergen components significantly increases in patients with seasonal allergic rhinitis. They demonstrated high level of sensitization to the Aspergillus fumigatus component m3. Thus, along with other clinical trials, the study performed would clarify some aspects of molecular pathogenesis of human allergic rhinitis.

Association between KIR genes and dust mite sensitization in a Brazilian population.

PubMed

Caniatti, Marcela Caleffi da Costa Lima; Borelli, Sueli Donizete; Guilherme, Ana Lúcia Falavigna; Franzener, Soraya Barrionuevo; Tsuneto, Luiza Tamie

2018-01-01

Killer cell immunoglobulin-like receptors (KIRs), found on the surface of natural killer (NK) cells, play a key role in controlling the innate response. Such response depends on a series of cellular interactions between these receptors and HLA activating/inhibiting ligands. Atopic diseases have been associated with genes that regulate cytokine production and HLA genes, which may either protect or predispose to hypersensitivity. To verify an association study of KIR genes with sensitization to the following mites: Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Blomia tropicalis. A total of 341 children aged up to 14 years, were classified as mite-sensitive or mite-insensitive after undergoing a skin prick test for immediate allergic reactions. The presence/absence of KIR genes and their human leukocyte antigen (HLA) ligands was determined by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) with the commercial kit LabType™ using Luminex™. The frequencies of KIR genes and their respective class I HLA ligands and the frequency of haplotypes were performed in sensitive and insensitive individuals, and no significant differences were found. Our results suggest no influence of KIR genes on resistance/susceptibility to sensitization to dust mites. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

[Influence of tissue-specific superoxide dismutase genes expression in brain cells on Drosophila melanogaster sensitivity to oxidative stress and viability].

PubMed

Vitushynska, M V; Matiytsiv, N P; Chernyk, Y

2015-01-01

The study has shown that both functional gene knockout Sodl and Sod2 and their overexpression in neurons and glial tissue increase the sensitivity of Drosophila melanogaster to oxidative stress (OS) conditions. The lowest survival rate was only 20.5% in insects with Sod2 knockout in neurons. Comparative analysis of the survival curves showed that adults with altered tissue-specific expression of the studied genes had reduced average and maximum life span. Under OS conditions induced by 5% hydrogen peroxide the life spans of wild type Oregon R and transgenic insects were significantly reduced. Altered Sod gene expression in glial tissue leads to degenerative changes in Drosophila brain at the young age. During the aging of insects and the action of pro-oxidants increasing of neurodegenerative phenotype is observed.

Highly transparent carbon counter electrode prepared via an in situ carbonization method for bifacial dye-sensitized solar cells.

PubMed

Bu, Chenghao; Liu, Yumin; Yu, Zhenhua; You, Sujian; Huang, Niu; Liang, Liangliang; Zhao, Xing-Zhong

2013-08-14

A facile in situ carbonization method was demonstrated to prepare the highly transparent carbon counter electrode (CE) with good mechanical stability for bifacial dye-sensitized solar cells (DSCs). The optical and electrochemical properties of carbon CEs were dramatically affected by the composition and concentration of the precursor. The well-optimized carbon CE exhibited high transparency and sufficient catalytic activity for I3(-) reduction. The bifacial DSC with obtained carbon CE achieved a high power conversion efficiency (PCE) of 5.04% under rear-side illumination, which approaches 85% that of front-side illumination (6.07%). Moreover, the device shows excellent stability as confirmed by the aging test. These promising results reveal the enormous potential of this transparent carbon CE in scaling up and commercialization of low cost and effective bifacial DSCs.

Developmental Regulation of Mitochondrial Apoptosis by c-Myc Governs Age- and Tissue-Specific Sensitivity to Cancer Therapeutics.

PubMed

Sarosiek, Kristopher A; Fraser, Cameron; Muthalagu, Nathiya; Bhola, Patrick D; Chang, Weiting; McBrayer, Samuel K; Cantlon, Adam; Fisch, Sudeshna; Golomb-Mello, Gail; Ryan, Jeremy A; Deng, Jing; Jian, Brian; Corbett, Chris; Goldenberg, Marti; Madsen, Joseph R; Liao, Ronglih; Walsh, Dominic; Sedivy, John; Murphy, Daniel J; Carrasco, Daniel Ruben; Robinson, Shenandoah; Moslehi, Javid; Letai, Anthony

2017-01-09

It is not understood why healthy tissues can exhibit varying levels of sensitivity to the same toxic stimuli. Using BH3 profiling, we find that mitochondria of many adult somatic tissues, including brain, heart, and kidneys, are profoundly refractory to pro-apoptotic signaling, leading to cellular resistance to cytotoxic chemotherapies and ionizing radiation. In contrast, mitochondria from these tissues in young mice and humans are primed for apoptosis, predisposing them to undergo cell death in response to genotoxic damage. While expression of the apoptotic protein machinery is nearly absent by adulthood, in young tissues its expression is driven by c-Myc, linking developmental growth to cell death. These differences may explain why pediatric cancer patients have a higher risk of developing treatment-associated toxicities. Copyright © 2017 Elsevier Inc. All rights reserved.

Stochastic multi-scale models of competition within heterogeneous cellular populations: Simulation methods and mean-field analysis.

PubMed

Cruz, Roberto de la; Guerrero, Pilar; Spill, Fabian; Alarcón, Tomás

2016-10-21

We propose a modelling framework to analyse the stochastic behaviour of heterogeneous, multi-scale cellular populations. We illustrate our methodology with a particular example in which we study a population with an oxygen-regulated proliferation rate. Our formulation is based on an age-dependent stochastic process. Cells within the population are characterised by their age (i.e. time elapsed since they were born). The age-dependent (oxygen-regulated) birth rate is given by a stochastic model of oxygen-dependent cell cycle progression. Once the birth rate is determined, we formulate an age-dependent birth-and-death process, which dictates the time evolution of the cell population. The population is under a feedback loop which controls its steady state size (carrying capacity): cells consume oxygen which in turn fuels cell proliferation. We show that our stochastic model of cell cycle progression allows for heterogeneity within the cell population induced by stochastic effects. Such heterogeneous behaviour is reflected in variations in the proliferation rate. Within this set-up, we have established three main results. First, we have shown that the age to the G1/S transition, which essentially determines the birth rate, exhibits a remarkably simple scaling behaviour. Besides the fact that this simple behaviour emerges from a rather complex model, this allows for a huge simplification of our numerical methodology. A further result is the observation that heterogeneous populations undergo an internal process of quasi-neutral competition. Finally, we investigated the effects of cell-cycle-phase dependent therapies (such as radiation therapy) on heterogeneous populations. In particular, we have studied the case in which the population contains a quiescent sub-population. Our mean-field analysis and numerical simulations confirm that, if the survival fraction of the therapy is too high, rescue of the quiescent population occurs. This gives rise to emergence of resistance to therapy since the rescued population is less sensitive to therapy. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Assessment of contrast gain signature in inferred magnocellular and parvocellular pathways in patients with glaucoma

PubMed Central

Sun, Hao; Swanson, William H.; Arvidson, Brian; Dul, Mitchell W.

2010-01-01

PURPOSE Contrast gain signatures of inferred magnocellular and parvocellular postreceptoral pathways were assessed for patients with glaucoma using a contrast discrimination paradigm developed by Pokorny and Smith. The potential causes for changes in contrast gain signature were investigated using model simulations of ganglion cell contrast responses. METHODS Foveal contrast discrimination thresholds were measured with a pedestal-Δ-pedestal paradigm developed by Pokorny and Smith (1997). Stimuli were 27 msec luminance increments superimposed on 227 msec pulsed Δ-pedestals. Contrast thresholds and contrast gain signatures mediated by the inferred magnocellular (MC) and parvocellular (PC) pathways were assessed using linear fits to contrast discrimination thresholds at either lower or higher Δ-pedestal contrasts, respectively. Twenty-seven patients with glaucoma were tested, as well as 16 age-similar control subjects free of eye disease. RESULTS Contrast sensitivity and contrast gain signature mediated by the inferred MC pathway were lower for the glaucoma group, and reduced contrast gain signature was correlated with reduced contrast sensitivity (r2=45%, p<0.0005). These two parameters mediated by the inferred PC pathway were little affected for the glaucoma group. Model simulations suggest that the reduced contrast sensitivity and contrast gain signature were consistent with the hypothesis that reduced MC ganglion cell dendritic complexity can lead to reduced effective retinal illuminance, and hence increased semi-saturation contrast of the ganglion cell contrast response functions. CONCLUSIONS The contrast sensitivity and contrast gain signature of the inferred MC pathway were reduced in patients with glaucoma. The results were consistent with a model of ganglion cell dysfunction due to reduced synaptic density. PMID:18501947

Changes in visceral adipose tissue plasma membrane lipid composition in old rats are associated with adipocyte hypertrophy with aging.

PubMed

Bonzón-Kulichenko, Elena; Moltó, Eduardo; Pintado, Cristina; Fernández, Alejandro; Arribas, Carmen; Schwudke, Dominik; Gallardo, Nilda; Shevchenko, Andrej; Andrés, Antonio

2018-04-16

Increased adiposity, through adipocyte hypertrophy and/or hyperplasia, characterizes aging and obesity. Both are leptin-resistant states, associated to disturbed lipid metabolism, reduced insulin sensitivity and inflammation. Nevertheless, fat tissue dysfunction appears earlier in obesity than in normal aging. In contrast, lipodystrophy is accompanied by diabetes, and improving the fat cell capacity to expand rescues the diabetic phenotype. Fat tissue dysfunction is extensively studied in the diet-induced obesity, but remains relatively neglected in the aging-associated obesity. In the Wistar rat, as occurs in humans, early or middle aging is accompanied by an increase in adiposity. Using this experimental model, we describe the molecular mechanisms contributing to the white adipose tissue (WAT) hypertrophy. WAT from middle-old age rats is characterized by decreased basal lipogenesis and lipolysis, increased esterification, as demonstrated by the higher TAG and cholesterol content in visceral WAT, and the maintenance of total ceramide levels within normal values. In addition, we describe alterations in the adipose tissue plasma membrane lipid composition, as increased total ether-phosphatidylcholine, sphingomyelin and free cholesterol levels that favor an enlarged fat cell size with aging. All these metabolic changes may be regarded as a survival advantage that prevents the aged rats from becoming overtly diabetic.

Recent developments in testicular germ cell tumor research.

PubMed

van de Geijn, Gert-Jan M; Hersmus, Remko; Looijenga, Leendert H J

2009-03-01

Testicular germ cell tumors of adolescents and adults (TGCTs; the so-called type II variant) are the most frequent malignancies found in Caucasian males between 20 and 40 years of age. The incidence has increased over the last decades. TGCTs are divided into seminomas and nonseminomas, the latter consisting of the subgroups embryonal carcinoma, yolk-sac tumor, teratoma, and choriocarcinoma. The pathogenesis starts in utero, involving primordial germ cells/gonocytes that are blocked in their differentiation, and develops via the precursor lesion carcinoma in situ toward invasiveness. TGCTs are totipotent and can be considered as stem cell tumors. The developmental capacity of their cell of origin, the primordial germ cells/gonocyte, is demonstrated by the different tumor histologies of the invasive TGCTs. Seminoma represents the germ cell lineage, and embryonal carcinoma is the undifferentiated component, being the stem cell population of the nonseminomas. Somatic differentiation is seen in the teratomas (all lineages), whereas yolk-sac tumors and choriocarcinoma represent extra-embryonal differentiation. Seminomas are highly sensitive to irradiation and (DNA damaging) chemotherapy, whereas most nonseminomatous elements are less susceptible to radiation, although still sensitive to chemotherapy, with the exception of teratoma. To allow early diagnosis and follow up, appropriate markers are mandatory to discriminate between the different subgroups. In this review, a summary will be given related to several recent developments in TGCT research, especially selected because of their putative clinical impact.

Evaluation of the performance of Human Papillomavirus testing in paired urine and clinician-collected cervical samples among women aged over 30 years in Bhutan.

PubMed

Tshomo, Ugyen; Franceschi, Silvia; Tshokey, Tshokey; Tobgay, Tashi; Baussano, Iacopo; Tenet, Vanessa; Snijders, Peter J F; Gheit, Tarik; Tommasino, Massimo; Vorsters, Alex; Clifford, Gary M

2017-04-08

Urine sampling may offer a less invasive solution than cervical sampling to test for human papillomavirus (HPV) for HPV vaccine impact monitoring. Paired samples of urine and exfoliated cervical cells were obtained for 89 women with history of high-risk (HR) HPV-positive normal cytology in Bhutan. Urine sampling protocol included self-collection of first-void urine immediately into a conservation medium and procedures to optimize DNA yield. Colposcopical abnormalities were biopsied. Two HPV assays were used: a multiplex type-specific PCR (E7-MPG) and a less analytically sensitive GP5+/6+ PCR followed by reverse line blot. HPV positivity for 21 types common to both assays was similar in urine and cells by E7-MPG (62.9% and 57.3%, respectively, p = 0.32) but lower in urine by GP5+/6+ (30.3% and 40.4%, p = 0.05). HPV6/11/16/18 positivity did not significantly differ between urine and cells by either assay. Sensitivity of urine (using cells as gold standard) to detect 21 HPV types was 80% and 58% for E7-MPG and GP5+/6+, respectively, with specificity 61% and 89%. HPV type distribution in urine and cells was similar, regardless of assay. The 5 detected CIN3+ were HR-HPV positive in cells by both assays, compared to 4 and 3 by E7-MPG and GP5+/6+, respectively, in urine samples. For the monitoring of vaccine impact, we demonstrate validity of a urine sampling protocol to obtain HPV prevalence data that are broadly comparable to that from cervical cells. However, detection of HPV in urine varies according to assay sensitivity, presumably because low level infections are frequent.

The Soybean Peptide Vglycin Preserves the Diabetic β-cells through Improvement of Proliferation and Inhibition of Apoptosis.

PubMed

Jiang, Hua; Tong, Yuxing; Yan, Dongjing; Jia, Shaohui; Ostenson, Claes-Goran; Chen, Zhengwang

2015-10-29

Replenishment of insulin-producing pancreatic β-cells would be beneficial in diabetes. The number of β-cells is maintained primarily by self-neogenesis to compensate for β-cell failure, loss or dedifferentiation. We present here a polypeptide vglycin, which was isolated and purified from germinating pea seeds. Vglycin exhibited positive effects in our diabetic models by promoting the proliferation and suppressing the apoptosis and dedifferentiation of β-cells. Vglycin promoted the restoration of β-cells in both young streptozotocin (STZ)-induced type 1 diabetic SD rats and in aged high-fat diet with (or without) STZ-induced type 2 diabetic C57BL/6 mice. We demonstrated that vglycin triggers this positive signaling by activating the insulin receptor and corresponding transcription factors. Impaired insulin sensitivity and glucose tolerance in aged T2DM mice were dramatically improved after long-term vglycin treatment, consistent with the altered level of inflammatory factor IL-1β/6. In addition, energy expenditure and body weights were significantly decreased in the mouse models after vglycin therapy. These results provide insight into the protective effects of vglycin on ameliorating β-cell function in standing glucolipotoxicity. Thus, vglycin may represent a new therapeutic agent for preventing and treating diabetes by replenishing endogenous insulin-positive cells.

An ultra-sensitive biophysical risk assessment of light effect on skin cells.

PubMed

Bennet, Devasier; Viswanath, Buddolla; Kim, Sanghyo; An, Jeong Ho

2017-07-18

The aim of this study was to analyze photo-dynamic and photo-pathology changes of different color light radiations on human adult skin cells. We used a real-time biophysical and biomechanics monitoring system for light-induced cellular changes in an in vitro model to find mechanisms of the initial and continuous degenerative process. Cells were exposed to intermittent, mild and intense (1-180 min) light with On/Off cycles, using blue, green, red and white light. Cellular ultra-structural changes, damages, and ECM impair function were evaluated by up/down-regulation of biophysical, biomechanical and biochemical properties. All cells exposed to different color light radiation showed significant changes in a time-dependent manner. Particularly, cell growth, stiffness, roughness, cytoskeletal integrity and ECM proteins of the human dermal fibroblasts-adult (HDF-a) cells showed highest alteration, followed by human epidermal keratinocytes-adult (HEK-a) cells and human epidermal melanocytes-adult (HEM-a) cells. Such changes might impede the normal cellular functions. Overall, the obtained results identify a new insight that may contribute to premature aging, and causes it to look aged in younger people. Moreover, these results advance our understanding of the different color light-induced degenerative process and help the development of new therapeutic strategies.

Impaired osteogenic differentiation and enhanced cellular receptor of advanced glycation end products sensitivity in patients with type 2 diabetes.

PubMed

Phimphilai, Mattabhorn; Pothacharoen, Peraphan; Kongtawelert, Prachya; Chattipakorn, Nipon

2017-11-01

Preclinical studies have demonstrated impaired osteoblast differentiation in type 2 diabetes (T2DM), which is related to skeletal accumulation of advanced glycation end products (AGEs). However, the role of AGE in osteoblast differentiation in patients with T2DM is unclear. This cross-sectional study was performed to investigate osteoblast differentiation and its association with serum pentosidine and soluble receptor of AGEs (sRAGE). Twenty-seven patients with T2DM and 15 age-matched controls were included to measure sRAGE and osteogenic differentiation in mononuclear cells derived from peripheral blood. The mononuclear cells isolated from patients with T2DM showed a significantly lower rate of osteogenic differentiation (7.4% vs 86.7%, p < 0.0001) with a lower level of ALPL, COL1A1, and BGLAP expression than those of controls by 11-, 44-, and 15-fold respectively, together with nonvisualized mineralization by alizarin red S staining. The levels of pentosidine and sRAGE were comparable in both groups. AGER expression was significantly higher in the T2DM group. BAX expression was also significantly higher in the T2DM group, and showed a strong correlation with AGER expression (r = 0.86, p < 0.0001). Fasting plasma glucose (FPG) level, AGER expression, and BAX expression showed a strong correlation with osteogenic differentiation defects on univariate analysis. However, only FPG showed a correlation with this defect in a multivariate analysis. In conclusion, patients with T2DM showed impairment of osteoblast differentiation, and FPG was an independent risk factor for this impairment. Moreover, T2DM showed a higher cellular sensitivity for activation of receptor of AGEs and higher cellular apoptosis, which may contribute to the defect in osteoblast differentiation.

Differential Effects of Ethanol on c-Jun N-Terminal Kinase, 14-3-3 Proteins, and Bax in Postnatal Day 4 and Postnatal Day 7 Rat Cerebellum

PubMed Central

Heaton, Marieta Barrow; Paiva, Michael; Kubovic, Stacey; Kotler, Alexandra; Rogozinski, Jonathan; Swanson, Eric; Madorsky, Vladimir; Posados, Michelle

2011-01-01

These studies investigated ethanol effects on upstream cellular elements and interactions which contribute to Bax-related apoptosis in neonatal rat cerebellum at ages of peak ethanol sensitivity (postnatal day 4 [P4]), compared to later ages of relative resistance (P7). Analyses were made of basal levels of the pro-apoptotic c-jun N-termimal kinase (JNK), Bax, and the 14-3-3 anchoring proteins, as well as the responsiveness of these substances to ethanol at P4 versus P7. Dimerization of Bax with 14-3-3 was also investigated at the two ages following ethanol treatment, a process which sequesters Bax in the cytosol, thus inhibiting its mitochondrial translocation and disruption of the mitochondrial membrane potential. Cultured cerebellar granule cells were used to examine the protective potential of JNK inhibition on ethanol-mediated cell death. Basal levels of JNK were significantly higher at P4 than P7, but no differences in the other proteins were found. Activated JNK, and cytosolic and mitochondrially-translocated Bax were increased in P4 but not P7 animals following ethanol exposure, while protective 14-3-3 proteins were increased only at P7. Ethanol treatment resulted in decreases in Bax:14-3-3 heterodimers at P4, but not at P7. Inhibition of JNK activity in vitro provided partial protection against ethanol neurotoxicity. Thus, differential temporal vulnerability to ethanol in this CNS region correlates with differences in both levels of apoptosis-related substances (e.g., JNK), and differential cellular responsiveness, favoring apoptosis at the most sensitive age and survival at the resistant age. The upstream elements contributing to this vulnerability can be targets for future therapeutic strategies. PMID:22169498

Circulating endothelial progenitor cells in obese children and adolescents.

PubMed

Pires, António; Martins, Paula; Paiva, Artur; Pereira, Ana Margarida; Marques, Margarida; Castela, Eduardo; Sena, Cristina; Seiça, Raquel

2015-01-01

This study aimed to investigate the relationship between circulating endothelial progenitor cell count and endothelial activation in a pediatric population with obesity. Observational and transversal study, including 120 children and adolescents with primary obesity of both sexes, aged 6-17 years, who were recruited at this Cardiovascular Risk Clinic. The control group was made up of 41 children and adolescents with normal body mass index. The variables analyzed were: age, gender, body mass index, systolic and diastolic blood pressure, high-sensitivity C-reactive protein, lipid profile, leptin, adiponectin, homeostasis model assessment-insulin resistance, monocyte chemoattractant protein-1, E-selectin, asymmetric dimethylarginine and circulating progenitor endothelial cell count. Insulin resistance was correlated to asymmetric dimethylarginine (ρ=0.340; p=0.003), which was directly, but weakly correlated to E-selectin (ρ=0.252; p=0.046). High sensitivity C-reactive protein was not found to be correlated to markers of endothelial activation. Systolic blood pressure was directly correlated to body mass index (ρ=0.471; p<0.001) and the homeostasis model assessment-insulin resistance (ρ=0.230; p=0.012), and inversely correlated to adiponectin (ρ=-0.331; p<0.001) and high-density lipoprotein cholesterol (ρ=-0.319; p<0.001). Circulating endothelial progenitor cell count was directly, but weakly correlated, to body mass index (r=0.211; p=0.016), leptin (ρ=0.245; p=0.006), triglyceride levels (r=0.241; p=0.031), and E-selectin (ρ=0.297; p=0.004). Circulating endothelial progenitor cell count is elevated in obese children and adolescents with evidence of endothelial activation, suggesting that, during infancy, endothelial repairing mechanisms are present in the context of endothelial activation. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

In vitro induction of monoclonal antibody-defined T-cell markers in lymphocytes from immunodeficient children by synthetic serum thymic factor (FTS).

PubMed Central

Bene, M C; Faure, G; Bordigoni, P; Olive, D; Duheille, J

1982-01-01

Lymphocytes from five children suffering from ataxia telangectasia or various unclassified immune deficiencies were tested in vitro for their sensitivity to synthetic serum thymic factor (FTS). The percentages of cells bearing T cell markers were elevated after incubation with FTS at graded concentrations (0.25, 2.5 and 25 ng/ml), by microlymphocytotoxicity or indirect immunofluorescence, using monoclonal anti-Lyt1 antibodies. In four cases, more than 30% of the non-T non-B cells acquired the Lyt1 T cell marker. These four children had low levels of circulating FTS. In the fifth child, who had a normal serum FTS level, and in two age-matched controls, there was no significant increase in the percentage of cells bearing the T marker. PMID:7049454

Characterization of vitamin D insensitive prostate cancer cells

PubMed Central

Alagbala, Adebusola A.; Johnson, Candace S.; Trump, Donald L.; Foster, Barbara A.

2007-01-01

The antitumor effects of 1,25-dihydroxyvitamin D3 (calcitriol) are being exploited for prevention and treatment of prostate cancer (CaP). These studies examined antitumor effects of calcitriol in primary cell cultures derived from transgenic adenocarcinoma of mouse prostate (TRAMP) mice chronically treated with calcitriol (20μg/kg) or vehicle 3x/week (MWF) from 4 weeks-of-age until palpable tumors developed. This is a report on the response of 2 representative control (vitamin D naïve, naïve) and calcitriol-treated (vitamin D insensitive, VDI) cells to calcitriol. VDI cells were less sensitive to calcitriol based on less cell growth inhibition and less inhibition of DNA synthesis as measured by MTT and BrdU incorporation assays. Similarly, VDI cells were also less sensitive to growth inhibition by the vitamin analog, 19-nor-1α,25-dihydroxyvitamin D2 (paricalcitol). There was no change in apoptosis following treatment of naïve and VDI cells with calcitriol. Vitamin D receptor (VDR) expression was up-regulated by calcitriol in both naïve and VDI cells. Calcitriol induced the vitamin D metabolizing enzyme, 24-hydroxylase (cyp24) mRNA and enzyme activity similarly in naïve and VDI cells as measured by RT-PCR and HPLC respectively. In summary, VDI cells are less responsive to the antiproliferative effects of calcitriol. Understanding vitamin D insensitivity will further clinical development of vitamin D compounds for prevention and treatment of CaP. PMID:17280828

Evaluating cytology for the detection of invasive cervical cancer.

PubMed

Landy, R; Castanon, A; Hamilton, W; Lim, A W W; Dudding, N; Hollingworth, A; Sasieni, P D

2016-06-01

To assess the sensitivity, the number needed to screen (NNS) and the positive predictive value (PPV) of cervical cytology for the diagnosis of cancer by age in a screening population. A retrospective cohort of women with invasive cervical cancer nested within a census of cervical cytology. All (c. 8 million) women aged 20-64 years with cervical cytology (excluding tests after an earlier abnormality). From April 2007 to March 2010, 3372 women had cervical cancer diagnosed within 12 months of such cytology in England. The sensitivity of cervical cytology to cancer, NNS to detect one cancer and predictive values of cytology were calculated for various 'referral' thresholds. These were calculated for ages 20-24, 25-34, 35-49 and 50-64 years. The sensitivity of at least moderate dyskaryosis [equivalent to a high-grade squamous intraepithelial lesion (HSIL) or worse] for cancer of 89.4% [95% confidence interval (CI) 88.3-90.4%] in women offered screening was independent of age. At all ages, women with borderline-early recall or mild dyskaryosis on cytology (equivalent to ASC-US and LSIL, respectively, in the Bethesda system) had a similar risk of cervical cancer to the risk in all women tested. The PPV of severe dyskaryosis/?invasive and ?glandular neoplasia cytology (equivalent to squamous cell carcinoma and adenocarcinoma/adenocarcinoma in situ, respectively, in the Bethesda System) were 34% and 12%, respectively; the PPV of severe dyskaryosis (HSIL: severe dysplasia) was 4%. The NNS was lowest when the incidence of cervical cancer was highest, at ages 25-39 years, but the proportion of those with abnormal cytology who have cancer was also lowest in younger women. The PPV of at least severe dyskaryosis (HSIL: severe dysplasia) for cancer was 4-10% of women aged 25-64 years, justifying a 2-week referral to colposcopy and demonstrating the importance of failsafe monitoring for such patients. The sensitivity of cytology for cervical cancer was excellent across all age groups. © 2015 The Authors Cytopathology Published by John Wiley & Sons Ltd.

Hyperandrogenism sensitizes mononuclear cells to promote glucose-induced inflammation in lean reproductive-age women

PubMed Central

Nair, K. Sreekumaran; Daniels, Janice K.; Basal, Eati; Schimke, Jill M.

2012-01-01

Hyperandrogenism and chronic low-grade inflammation are related in polycystic ovary syndrome (PCOS), but it is unknown whether hyperandrogenemia can activate inflammation. We determined the effect of oral androgen administration on fasting and glucose-stimulated nuclear factor-κB (NF-κB) activation and expression and related markers of inflammation in mononuclear cells (MNC) of lean reproductive-age women. Sixteen lean, ovulatory reproductive-age women were treated with 130 mg of DHEA or placebo (n = 8 each) for 5 days in a randomized, controlled, double-blind fashion. Nuclear activation of NF-κB, p65 and p105 NF-κB subunit RNA, TNFα and IL-1β mRNA, and NF-κB p65 and inhibitory-κB (IκB) protein were quantified from MNC obtained while fasting and 2 h after glucose ingestion, before and after DHEA or placebo administration. Before treatment, subjects receiving DHEA or placebo exhibited no differences in androgens or any inflammatory markers while fasting and after glucose ingestion. Compared with placebo, DHEA administration raised levels of testosterone, androstenedione, and DHEA-S, increased the percent change in fasting and glucose-challenged activated NF-κB, p65, p105, TNFα, and IL-1β RNA and p65 protein, and decreased the percent change in fasting and glucose-challenged IκB protein. We conclude that elevation of circulating androgens to the range observed in PCOS upregulates the NF-κB inflammation pathway in lean reproductive-age women. Thus, hyperandrogenemia activates and sensitizes MNC to glucose in this population. PMID:22045316

Hyperandrogenism sensitizes mononuclear cells to promote glucose-induced inflammation in lean reproductive-age women.

PubMed

González, Frank; Nair, K Sreekumaran; Daniels, Janice K; Basal, Eati; Schimke, Jill M

2012-02-01

Hyperandrogenism and chronic low-grade inflammation are related in polycystic ovary syndrome (PCOS), but it is unknown whether hyperandrogenemia can activate inflammation. We determined the effect of oral androgen administration on fasting and glucose-stimulated nuclear factor-κB (NF-κB) activation and expression and related markers of inflammation in mononuclear cells (MNC) of lean reproductive-age women. Sixteen lean, ovulatory reproductive-age women were treated with 130 mg of DHEA or placebo (n = 8 each) for 5 days in a randomized, controlled, double-blind fashion. Nuclear activation of NF-κB, p65 and p105 NF-κB subunit RNA, TNFα and IL-1β mRNA, and NF-κB p65 and inhibitory-κB (IκB) protein were quantified from MNC obtained while fasting and 2 h after glucose ingestion, before and after DHEA or placebo administration. Before treatment, subjects receiving DHEA or placebo exhibited no differences in androgens or any inflammatory markers while fasting and after glucose ingestion. Compared with placebo, DHEA administration raised levels of testosterone, androstenedione, and DHEA-S, increased the percent change in fasting and glucose-challenged activated NF-κB, p65, p105, TNFα, and IL-1β RNA and p65 protein, and decreased the percent change in fasting and glucose-challenged IκB protein. We conclude that elevation of circulating androgens to the range observed in PCOS upregulates the NF-κB inflammation pathway in lean reproductive-age women. Thus, hyperandrogenemia activates and sensitizes MNC to glucose in this population.

Association of Androgen Excess with Glucose Intolerance in Women with Polycystic Ovary Syndrome.

PubMed

Zhang, Bingjie; Wang, Jing; Shen, Shanmei; Liu, Jiayi; Sun, Jie; Gu, Tianwei; Ye, Xiao; Zhu, Dalong; Bi, Yan

2018-01-01

Women with polycystic ovary syndrome (PCOS) show high prevalence of glucose intolerance. This study aimed to investigate the association of androgen excess with glucose intolerance in PCOS. A total of 378 women with PCOS participated in the study. Free androgen index (FAI) was selected as indicator of hyperandrogenism. Insulin sensitivity was assessed by 1/homeostasis model assessment of insulin resistance (1/HOMA-IR) and Matsuda insulin sensitivity index (ISI M ); β -cell function was assessed by disposition index (DI). We found that women with glucose intolerance had higher FAI levels compared to women with normal glucose tolerance (NGT) (prediabetes 6.2, T2DM 7.9 versus NGT 5.0, resp.; p < 0.001). Furthermore, there was a direct association between FAI levels and frequency of glucose intolerance (OR = 2.480, 95% CI 1.387-4.434), even after adjusting for age, BMI, waist circumference, hypertension, fasting insulin, testosterone, SHBG, and family history of diabetes. In addition, with FAI increase, glycosylated hemoglobin (HbA1c), plasma glucose concentrations, and serum insulin levels increased, while insulin sensitivity and β -cell function decreased. Our results suggested that androgen excess indicated by high FAI levels might serve as indicator of glucose intolerance, as it might promote insulin resistance and β -cell dysfunction in women with PCOS.

Long-lived crowded-litter mice exhibit lasting effects on insulin sensitivity and energy homeostasis.

PubMed

Sadagurski, Marianna; Landeryou, Taylor; Blandino-Rosano, Manuel; Cady, Gillian; Elghazi, Lynda; Meister, Daniel; See, Lauren; Bartke, Andrzej; Bernal-Mizrachi, Ernesto; Miller, Richard A

2014-06-01

The action of nutrients on early postnatal growth can influence mammalian aging and longevity. Recent work has demonstrated that limiting nutrient availability in the first 3 wk of life [by increasing the number of pups in the crowded-litter (CL) model] leads to extension of mean and maximal lifespan in genetically normal mice. In this study, we aimed to characterize the impact of early-life nutrient intervention on glucose metabolism and energy homeostasis in CL mice. In our study, we used mice from litters supplemented to 12 or 15 pups and compared those to control litters limited to eight pups. At weaning and then throughout adult life, CL mice are significantly leaner and consume more oxygen relative to control mice. At 6 mo of age, CL mice had low fasting leptin concentrations, and low-dose leptin injections reduced body weight and food intake more in CL female mice than in controls. At 22 mo, CL female mice also have smaller adipocytes compared with controls. Glucose and insulin tolerance tests show an increase in insulin sensitivity in 6 mo old CL male mice, and females become more insulin sensitive later in life. Furthermore, β-cell mass was significantly reduced in the CL male mice and was associated with reduction in β-cell proliferation rate in these mice. Together, these data show that early-life nutrient intervention has a significant lifelong effect on metabolic characteristics that may contribute to the increased lifespan of CL mice.

Roles of the Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR pathways in controlling growth and sensitivity to therapy-implications for cancer and aging

PubMed Central

Steelman, Linda S.; Chappell, William H.; Abrams, Stephen L.; Kempf, C. Ruth; Long, Jacquelyn; Laidler, Piotr; Mijatovic, Sanja; Maksimovic-Ivanic, Danijela; Stivala, Franca; Mazzarino, Maria C.; Donia, Marco; Fagone, Paolo; Malaponte, Graziella; Nicoletti, Ferdinando; Libra, Massimo; Milella, Michele; Tafuri, Agostino; Bonati, Antonio; Bäsecke, Jörg; Cocco, Lucio; Evangelisti, Camilla; Martelli, Alberto M.; Montalto, Giuseppe; Cervello, Melchiorre; McCubrey, James A.

2011-01-01

Dysregulated signaling through the Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR pathways is often the result of genetic alterations in critical components in these pathways or upstream activators. Unrestricted cellular proliferation and decreased sensitivity to apoptotic-inducing agents are typically associated with activation of these pro-survival pathways. This review discusses the functions these pathways have in normal and neoplastic tissue growth and how they contribute to resistance to apoptotic stimuli. Crosstalk and commonly identified mutations that occur within these pathways that contribute to abnormal activation and cancer growth will also be addressed. Finally the recently described roles of these pathways in cancer stem cells, cellular senescence and aging will be evaluated. Controlling the expression of these pathways could ameliorate human health. PMID:21422497

Manifestations of Dynamic Strain Aging in Soft-Oriented NiAl Single Crystals

NASA Technical Reports Server (NTRS)

Weaver, M. L.; Kaufman, M. J.; Noebe, R. D.

1996-01-01

The tensile and compressive properties of six NiAl-base single-crystal alloys have been investigated at temperatures between 77 and 1200 K. The normalized critical resolved shear stresses (CRSS/E) and work-hardening rates (Theta/E) for these alloys generally decreased with increasing temperature. However, anomalous peaks or plateaus for these properties were observed in conventional purity (CPNiAl), Si-doped (NiAl-Si), C-doped low Si (UF-NiAl1), and Mo-doped (NiAl-Mo) alloys at intermediate temperatures (600 to 1000 K). This anomalous behavior was not observed in high-purity, low interstitial material (HP-NiAl). Low or negative strain-rate sensitivities (SRS) also were observed in all six alloys in this intermediate temperature range. Coincident with the occurrence of negative strain-rate sensitivities was the observation of serrated stress-strain curves in the CPNiAl and NiAl-Si alloys. These phenomena have been attributed to dynamic strain aging (DSA). Chemical analysis of the alloys used in this study suggests that the main specie responsible for strain aging in NiAl is C but indicate that residual Si impurities can enhance the strain aging effects. The corresponding dislocation microstructures at low temperatures (300 to 600 K) were composed of well-defined cells. At intermediate temperatures (600 to 900 K), either poorly defined cells or coarse bands of localized slip, reminiscent of the vein structures observed in low-cycle fatigue specimens deformed in the DSA regime, were observed in conventional purity, Si-doped, and in Mo-doped alloys. In contrast, a well-defined cell structure persisted in the low interstitial, high-purity alloy. At elevated temperatures (greater than or equal to 1000 K), more uniformly distributed dislocations and sub-boundaries were observed in all alloys. These observations are consistent with the occurrence of DSA in NiAl single-crystal alloys at intermediate temperatures.

Optically transparent cathode for Co(III/II) mediated dye-sensitized solar cells based on graphene oxide.

PubMed

Kavan, Ladislav; Yum, Jun-Ho; Graetzel, Michael

2012-12-01

Thin semitransparent films were fabricated on F-doped SnO(2) (FTO) from single-layer graphene oxide (GO) either pure or in a composite with graphene nanoplatelets. Electrocatalytic activity of prepared films was tested for the Co(bpy)(3)(3+/2+) redox couple in acetonitrile electrolyte solution. Pristine GO showed almost no activity, resembling the properties of basal plane pyrolytic graphite. However, electrochemical performance of graphene oxide improved dramatically upon chemical reduction with hydrazine and/or heat treatment. All GO-containing films were firmly bonded to FTO, which contrasted with the poor adhesion of sole graphene nanoplatelets to this support. The activity loss during long-term aging was considerably improved, too. Enhanced stability of GO-containing films together with high electrocatalytic activity is beneficial for application in a new generation of dye-sensitized solar cells employing Co(bpy)(3)(3+/2+) as the redox shuttle.

Ethanol Influences on Bax Associations with Mitochondrial Membrane Proteins in Neonatal Rat Cerebellum

PubMed Central

Heaton, Marieta Barrow; Siler-Marsiglio, Kendra; Paiva, Michael; Kotler, Alexandra; Rogozinski, Jonathan; Kubovec, Stacey; Coursen, Mary; Madorsky, Vladimir

2012-01-01

These studies investigated interactions taking place at the mitochondrial membrane in neonatal rat cerebellum following ethanol exposure, and focused on interactions between pro-apoptotic Bax and proteins of the permeability transition pore (PTP), voltage-dependent anion channel (VDAC), and adenine nucleotide translocator (ANT), of the outer and inner mitochondrial membranes, respectively. Cultured cerebellar granule cells were used to assess the role of these interactions in ethanol neurotoxicity. Analyses were made at the age of maximal cerebellar ethanol vulnerability (P4), compared to the later age of relative resistance (P7), to determine whether differential ethanol sensitivity was mirrored by differences in these molecular interactions. We found that following ethanol exposure, Bax pro-apoptotic associations with both VDAC and ANT were increased, particularly at the age of greater ethanol sensitivity, and these interactions were sustained at this age for at least two hours post-exposure. Since Bax:VDAC interactions disrupt protective VDAC interactions with mitochondrial hexokinase (HXK), we also assessed VDAC:HXK associations following ethanol treatment, and found such interactions were altered by ethanol treatment, but only at two-hours post-exposure, and only in the P4, ethanol-sensitive cerebellum. Ethanol neurotoxicity in cultured neuronal preparations was abolished by pharmacological inhibition of both VDAC and ANT interactions with Bax, but not by a Bax channel blocker. Therefore, we conclude that at this age, within the constraints of our experimental model, a primary mode of Bax-induced initiation of the apoptosis cascade following ethanol insult involves interactions with proteins of the PTP complex, and not channel formation independent of PTP constituents. PMID:22767450

Association of Sleep Deprivation With Reduction in Insulin Sensitivity as Assessed by the Hyperglycemic Clamp Technique in Adolescents.

PubMed

De Bernardi Rodrigues, Ana Maria; da Silva, Cleliani de Cassia; Vasques, Ana Carolina Junqueira; Camilo, Daniella Fernandes; Barreiro, Francieli; Cassani, Roberta Soares Lara; Zambon, Mariana Porto; Antonio, Maria Ângela Reis de Góes Monteiro; Geloneze, Bruno

2016-05-01

The association between short sleep duration and decreased insulin sensitivity in adolescents has been described. However, to our knowledge, no studies have investigated this association measuring insulin sensitivity by the hyperglycemic clamp technique. To compare the distributions of parameters of insulin resistance in adolescents with sleep deprivation vs adequate sleep, and to investigate the association between sleep deprivation and insulin sensitivity. Cross-sectional multicenter study using data from the Brazilian Metabolic Syndrome Study conducted from June 29, 2011, to December 3, 2014, at an obesity outpatient clinic at the University of Campinas and public schools, with a convenience sample of 615 adolescents aged 10 to 19.9 years with a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) for age and sex at the fifth percentile or higher. A subsample of 81 adolescents underwent the hyperglycemic clamp technique. The self-reported sleep duration was used to classify the population into 2 groups: adolescents with sleep deprivation (<8 hours/night) and adolescents with adequate sleep (≥8 hours/night). Insulin sensitivity was assessed using the hyperglycemic clamp technique. Among the 615 adolescents (56.3% female; median age, 15.9 years [interquartile range, 12.9-17.8 years]) included in the sample, the mean (SD) sleep duration was 7.9 (1.7) hours/night. The adolescents with sleep deprivation (n = 257) compared with those with adequate sleep (n = 358) had a higher median (interquartile range) age (17.0 [15.4-18.3] vs 14.1 [11.8-16.9] years), BMI (25.0 [21.2-29.3] vs 23.1 [19.5-27.6]), waist circumference (83.0 [73.5-95.4] vs 79.0 [68.5-91.0] cm), sagittal abdominal diameter (17.9 [15.8-20.8] vs 17.0 [15.0-19.8] cm), neck circumference (35.2 [33.0-38.0] vs 33.0 [30.0-35.5] cm), uric acid level (4.9 [4.0-5.8] vs 4.5 [3.7-5.5] mg/dL), and white blood cell count (7000 [5900-8200] vs 6600 [5600-7800] cells/μL) (all P < .05). Moreover, the adolescents with sleep deprivation had a lower median (interquartile range) insulin sensitivity index compared with those with adequate sleep (0.10 [0.05-0.21] vs 0.21 [0.09-0.33] mg · kgfat-free mass-1 · min-1 · mU/L × 100, respectively; difference, -0.01; 95% CI, -0.01 to -0.00; P = .02). After controlling for age and sex in the multivariate regression model, sleep deprivation remained an independent predictor for those variables. In the sleep deprivation group, BMI and central distribution of fat were higher in all categories of adiposity. Sleep deprivation (<8 hours of sleep per night) is associated with centripetal distribution of fat and decreased insulin sensitivity in adolescents. Therefore, investigations of sleep duration and sleep quality in adolescents should be included in clinical practice to promote, through health education, the eradication of the health risks associated with sleep restriction.

RasGRP1 confers the phorbol ester-sensitive phenotype to EL4 lymphoma cells.

PubMed

Han, Shujie; Knoepp, Stewart M; Hallman, Mark A; Meier, Kathryn E

2007-01-01

The murine EL4 lymphoma cell line exists in variants that are either sensitive or resistant to the tumor promoter phorbol 12-myristate 13-acetate (PMA). In sensitive EL4 cells, PMA causes robust Erk mitogen-activated protein kinase activation that results in growth arrest. In resistant cells, PMA induces minimal Erk activation, without growth arrest. PMA stimulates IL-2 production in sensitive, but not resistant, cells. The role of RasGRP1, a PMA-activated guanine nucleotide exchange factor for Ras, in EL4 phenotype was examined. Endogenous RasGRP1 protein is expressed at much higher levels in sensitive than in resistant cells. PMA-induced Ras activation is observed in sensitive cells but not in resistant cells lacking Ras-GRP1. PMA induces down-regulation of RasGRP1 protein in sensitive cells but increases RasGRP1 in resistant cells. Transfection of RasGRP1 into resistant cells enhances PMA-induced Erk activation. In the reverse experiment, introduction of small interfering RNA (siRNA) for RasGRP1 suppresses PMA-induced Ras and Erk activations in sensitive cells. Sensitive cells incubated with siRNA for RasGRP1 exhibit the PMA-resistant phenotype, in that they are able to proliferate in the presence of PMA and do not secrete IL-2 when stimulated with PMA. These studies indicate that the PMA-sensitive phenotype, as previously defined for the EL4 cell line, is conferred by endogenous expression of RasGRP1 protein.

Aging and the genetic road towards the positivity effect in memory.

PubMed

Mammarella, Nicola; Di Domenico, Alberto; Fairfield, Beth

2016-09-01

Better memory for positive information compared to negative and neutral information has been repeatedly associated with successful aging. The main psychological explanations for this so-called "positivity effect" in memory principally rely on emotional, motivational, and cognitive mechanisms that make older adults' cognition highly sensitive to positive information according to ultimate goals of well-being. However, emerging evidence also delineates a genetic profile for positivity effects in memory, which may render some older adults more prone than others to encoding and remembering positive memories. First, we present a brief overview of behavioral and neuroimaging studies about the positivity effect in aging. Subsequently, we report studies on candidate genes associated with positive memories. In particular, we review work to date on several candidate genes that are sensitive to stimulus valence such as ADRA2B, COMT, and 5HTTLPR. Finally, we propose that the future approach to the study of genetic correlates of positivity effects in memory should also include mitochondrial functioning (TOMM40). Altogether, the study of genetics and cell biology of positivity effects in memory can help us to reveal the underlying bottom-up pathways to positive affect in healthy aging. Copyright © 2016 Elsevier Inc. All rights reserved.

Safety and Utility of Quantitative Sensory Testing among Adults with Sickle Cell Disease: Indicators of Neuropathic Pain?

PubMed Central

Ezenwa, Miriam O.; Molokie, Robert E.; Wang, Zaijie Jim; Yao, Yingwei; Suarez, Marie L.; Pullum, Cherese; Schlaeger, Judith M.; Fillingim, Roger B.; Wilkie, Diana J.

2014-01-01

Objectives Pain is the hallmark symptom of sickle cell disease (SCD), yet the types of pain that these patients experience, and the underlying mechanisms, have not been well characterized. The study purpose was to determine the safety and utility of a mechanical and thermal quantitative sensory testing (QST) protocol and the feasibility of utilizing neuropathic pain questionnaires among adults with SCD. Methods A convenience sample (N=25, 18 women, mean age 38.5 ± 12.5 [20–58 years]) completed self-report pain and quality-of-life tools. Subjects also underwent testing with the TSA-II NeuroSensory Analyzer and calibrated von Frey microfilaments. Results We found that the QST protocol was safe and did not stimulate a SCD pain crisis. There was evidence of central sensitization (n=15), peripheral sensitization (n=1), a mix of central and peripheral sensitization (n=8), or no sensitization (n=1). The neuropathic pain self-report tools were feasible with evidence of construct validity; 40% of the subjects reported S-LANSS scores that were indicative of neuropathic pain and had evidence of central, peripheral or mixed sensitization. Discussion The QST protocol can be safely conducted in adults with SCD and provides evidence of central or peripheral sensitization, which is consistent with a neuropathic component to SCD pain. These findings are novel, warrant a larger confirmatory study, and indicate the need for normative QST data from African American adults and older adults. PMID:25581383

Differential sensitivity of melanoma cell lines with BRAFV600E mutation to the specific Raf inhibitor PLX4032

PubMed Central

2010-01-01

Blocking oncogenic signaling induced by the BRAFV600E mutation is a promising approach for melanoma treatment. We tested the anti-tumor effects of a specific inhibitor of Raf protein kinases, PLX4032/RG7204, in melanoma cell lines. PLX4032 decreased signaling through the MAPK pathway only in cell lines with the BRAFV600E mutation. Seven out of 10 BRAFV600E mutant cell lines displayed sensitivity based on cell viability assays and three were resistant at concentrations up to 10 μM. Among the sensitive cell lines, four were highly sensitive with IC50 values below 1 μM, and three were moderately sensitive with IC50 values between 1 and 10 μM. There was evidence of MAPK pathway inhibition and cell cycle arrest in both sensitive and resistant cell lines. Genomic analysis by sequencing, genotyping of close to 400 oncogeninc mutations by mass spectrometry, and SNP arrays demonstrated no major differences in BRAF locus amplification or in other oncogenic events between sensitive and resistant cell lines. However, metabolic tracer uptake studies demonstrated that sensitive cell lines had a more profound inhibition of FDG uptake upon exposure to PLX4032 than resistant cell lines. In conclusion, BRAFV600E mutant melanoma cell lines displayed a range of sensitivities to PLX4032 and metabolic imaging using PET probes can be used to assess sensitivity. PMID:20406486

Autophagy in the eye: Development, degeneration, and aging.

PubMed

Boya, Patricia; Esteban-Martínez, Lorena; Serrano-Puebla, Ana; Gómez-Sintes, Raquel; Villarejo-Zori, Beatriz

2016-11-01

Autophagy is a catabolic pathway that promotes the degradation and recycling of cellular components. Proteins, lipids, and even whole organelles are engulfed in autophagosomes and delivered to the lysosome for elimination. In response to stress, autophagy mediates the degradation of cell components, which are recycled to generate the nutrients and building blocks required to sustain cellular homeostasis. Moreover, it plays an important role in cellular quality control, particularly in neurons, in which the total burden of altered proteins and damaged organelles cannot be reduced by redistribution to daughter cells through cell division. Research has only begun to examine the role of autophagy in the visual system. The retina, a light-sensitive tissue, detects and transmits electrical impulses through the optic nerve to the visual cortex in the brain. Both the retina and the eye are exposed to a variety of environmental insults and stressors, including genetic mutations and age-associated alterations that impair their function. Here, we review the main studies that have sought to explain autophagy's importance in visual function. We describe the role of autophagy in retinal development and cell differentiation, and discuss the implications of autophagy dysregulation both in physiological aging and in important diseases such as age-associated macular degeneration and glaucoma. We also address the putative role of autophagy in promoting photoreceptor survival and discuss how selective autophagy could provide alternative means of protecting retinal cells. The findings reviewed here underscore the important role of autophagy in maintaining proper retinal function and highlight novel therapeutic approaches for blindness and other diseases of the eye. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microglial cell dysregulation in brain aging and neurodegeneration

PubMed Central

von Bernhardi, Rommy; Eugenín-von Bernhardi, Laura; Eugenín, Jaime

2015-01-01

Aging is the main risk factor for neurodegenerative diseases. In aging, microglia undergoes phenotypic changes compatible with their activation. Glial activation can lead to neuroinflammation, which is increasingly accepted as part of the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD). We hypothesize that in aging, aberrant microglia activation leads to a deleterious environment and neurodegeneration. In aged mice, microglia exhibit an increased expression of cytokines and an exacerbated inflammatory response to pathological changes. Whereas LPS increases nitric oxide (NO) secretion in microglia from young mice, induction of reactive oxygen species (ROS) predominates in older mice. Furthermore, there is accumulation of DNA oxidative damage in mitochondria of microglia during aging, and also an increased intracellular ROS production. Increased ROS activates the redox-sensitive nuclear factor kappa B, which promotes more neuroinflammation, and can be translated in functional deficits, such as cognitive impairment. Mitochondria-derived ROS and cathepsin B, are also necessary for the microglial cell production of interleukin-1β, a key inflammatory cytokine. Interestingly, whereas the regulatory cytokine TGFβ1 is also increased in the aged brain, neuroinflammation persists. Assessing this apparent contradiction, we have reported that TGFβ1 induction and activation of Smad3 signaling after inflammatory stimulation are reduced in adult mice. Other protective functions, such as phagocytosis, although observed in aged animals, become not inducible by inflammatory stimuli and TGFβ1. Here, we discuss data suggesting that mitochondrial and endolysosomal dysfunction could at least partially mediate age-associated microglial cell changes, and, together with the impairment of the TGFβ1-Smad3 pathway, could result in the reduction of protective activation and the facilitation of cytotoxic activation of microglia, resulting in the promotion of neurodegenerative diseases. PMID:26257642

Assessment of contrast gain signature in inferred magnocellular and parvocellular pathways in patients with glaucoma.

PubMed

Sun, Hao; Swanson, William H; Arvidson, Brian; Dul, Mitchell W

2008-11-01

Contrast gain signatures of inferred magnocellular and parvocellular postreceptoral pathways were assessed for patients with glaucoma using a contrast discrimination paradigm developed by Pokorny and Smith. The potential causes for changes in contrast gain signature were investigated using model simulations of ganglion cell contrast responses. Foveal contrast discrimination thresholds were measured with a pedestal-Delta-pedestal paradigm developed by Pokorny and Smith [Pokorny, J., & Smith, V. C. (1997). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain. Journal of the Optical Society of America A, 14(9), 2477-2486]. Stimuli were 27 ms luminance increments superimposed on 227 ms pulsed Delta-pedestals. Contrast thresholds and contrast gain signatures mediated by the inferred magnocellular (MC) and parvocellular (PC) pathways were assessed using linear fits to contrast discrimination thresholds at either lower or higher Delta-pedestal contrasts, respectively. Twenty-seven patients with glaucoma were tested, as well as 16 age-similar control subjects free of eye disease. Contrast sensitivity and contrast gain signature mediated by the inferred MC pathway were lower for the glaucoma group, and reduced contrast gain signature was correlated with reduced contrast sensitivity (r(2)=45%, p<.0005). These two parameters mediated by the inferred PC pathway were little affected for the glaucoma group. Model simulations suggest that the reduced contrast sensitivity and contrast gain signature were consistent with the hypothesis that reduced MC ganglion cell dendritic complexity can lead to reduced effective retinal illuminance, and hence increased semi-saturation contrast of the ganglion cell contrast response functions. The contrast sensitivity and contrast gain signature of the inferred MC pathway were reduced in patients with glaucoma. The results were consistent with a model of ganglion cell dysfunction due to reduced synaptic density.

Role of advanced glycation on aggregation and DNA binding properties of α-synuclein.

PubMed

Padmaraju, Vasudevaraju; Bhaskar, Jamuna J; Prasada Rao, Ummiti J S; Salimath, Paramahans V; Rao, K S

2011-01-01

Parkinson's disease (PD) is a neurodegenerative disease with multiple etiologies. Advanced glycation end products (AGEs) accumulate in the aging brain and could be one of the reasons for age-related diseases like PD. Oxidative stress also leads to the formation of AGEs and may be involved in neurodegeneration by altering the properties of proteins. α-Synuclein is involved in pathogenesis of PD and there are limited studies on the role of AGE-α-synuclein in neurodegeneration. We studied the aggregation and DNA binding ability of AGE-α-synuclein in vitro. α-Synuclein is glycated using methylglyoxal and formation of AGE-α-synuclein is characterized using fluorescence studies, intrinsic tyrosine fluorescence, and fructosamine estimation. The results indicated that AGE-α-synuclein aggregates into smaller globular-like aggregates compared to fibrils formed with native α-synuclein. Further, it is found that AGE-α-synuclein induced conformational changes in scDNA from B-form to B-C-A mixed conformation. Additionally, AGE-α-synuclein altered DNA integrity as evidenced by the melting temperature, ethidium bromide, and DNAse I sensitivity studies. AGE-α-synuclein converted biphasic Tm to higher monophasic Tm. The Tm of AGE-α-synuclein-scDNA complex is more than that of native α-synuclein-scDNA complex, indicating that AGE-α-synuclein stabilized the uncoiled scDNA. AGE-α-synuclein could stabilize the uncoiled scDNA, as shown by the decrease in the number of ethidium bromide binding molecules per base pair of DNA. DNAse I sensitive studies indicated that both AGE-α-synuclein-scDNA and α-synuclein-scDNA are resistant to DNAse I digestion. The relevance of these findings to neuronal cell death is discussed.

Hypersensitivity of skin fibroblasts from basal cell nevus syndrome patients to killing by ultraviolet B but not by ultraviolet C radiation

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

Applegate, L.A.; Goldberg, L.H.; Ley, R.D.

Basal cell nevus syndrome (BCNS) is an autosomal dominant genetic disorder in which the afflicted individuals are extremely susceptible to sunlight-induced skin cancers, particularly basal cell carcinomas. However, the cellular and molecular basis for BCNS is unknown. To ascertain whether there is any relationship between genetic predisposition to skin cancer and increased sensitivity of somatic cells from BCNS patients to killing by UV radiation, we exposed skin fibroblasts established from unexposed skin biopsies of several BCNS and age- and sex-matched normal individuals to either UV-B (280-320 nm) or UV-C (254 nm) radiation and determined their survival. The results indicated thatmore » skin fibroblasts from BCNS patients were hypersensitive to killing by UV-B but not UV-C radiation as compared to skin fibroblasts from normal individuals. DNA repair studies indicated that the increased sensitivity of BCNS skin fibroblasts to killing by UV-B radiation was not due to a defect in the excision repair of pyrimidine dimers. These results indicate that there is an association between hypersensitivity of somatic cells to killing by UV-B radiation and the genetic predisposition to skin cancer in BCNS patients. In addition, these results suggest that DNA lesions (and repair processes) other than the pyrimidine dimer are also involved in the pathogenesis of sunlight-induced skin cancers in BCNS patients. More important, the UV-B sensitivity assay described here may be used as a diagnostic tool to identify presymptomatic individuals with BCNS.« less

Barn owls have ageless ears.

PubMed

Krumm, Bianca; Klump, Georg; Köppl, Christine; Langemann, Ulrike

2017-09-27

We measured the auditory sensitivity of the barn owl ( Tyto alba ), using a behavioural Go/NoGo paradigm in two different age groups, one younger than 2 years ( n = 4) and another more than 13 years of age ( n = 3). In addition, we obtained thresholds from one individual aged 23 years, three times during its lifetime. For computing audiograms, we presented test frequencies of between 0.5 and 12 kHz, covering the hearing range of the barn owl. Average thresholds in quiet were below 0 dB sound pressure level (SPL) for frequencies between 1 and 10 kHz. The lowest mean threshold was -12.6 dB SPL at 8 kHz. Thresholds were the highest at 12 kHz, with a mean of 31.7 dB SPL. Test frequency had a significant effect on auditory threshold but age group had no significant effect. There was no significant interaction between age group and test frequency. Repeated threshold estimates over 21 years from a single individual showed only a slight increase in thresholds. We discuss the auditory sensitivity of barn owls with respect to other species and suggest that birds, which generally show a remarkable capacity for regeneration of hair cells in the basilar papilla, are naturally protected from presbycusis. © 2017 The Author(s).

Aging of mice is associated with p16(Ink4a)- and β-galactosidase-positive macrophage accumulation that can be induced in young mice by senescent cells.

PubMed

Hall, Brandon M; Balan, Vitaly; Gleiberman, Anatoli S; Strom, Evguenia; Krasnov, Peter; Virtuoso, Lauren P; Rydkina, Elena; Vujcic, Slavoljub; Balan, Karina; Gitlin, Ilya; Leonova, Katerina; Polinsky, Alexander; Chernova, Olga B; Gudkov, Andrei V

2016-07-01

Senescent cells (SCs) have been considered a source of age-related chronic sterile systemic inflammation and a target for anti-aging therapies. To understand mechanisms controlling the amount of SCs, we analyzed the phenomenon of rapid clearance of human senescent fibroblasts implanted into SCID mice, which can be overcome when SCs were embedded into alginate beads preventing them from immunocyte attack. To identify putative SC killers, we analyzed the content of cell populations in lavage and capsules formed around the SC-containing beads. One of the major cell types attracted by secretory factors of SCs was a subpopulation of macrophages characterized by p16(Ink4a) gene expression and β-galactosidase activity at pH6.0 (β-gal(pH6)), thus resembling SCs. Consistently, mice with p16(Ink4a) promoter-driven luciferase, developed bright luminescence of their peritoneal cavity within two weeks following implantation of SCs embedded in alginate beads. p16(Ink4a)/β-gal(pH6)-expressing cells had surface biomarkers of macrophages F4/80 and were sensitive to liposomal clodronate used for the selective killing of cells capable of phagocytosis. At the same time, clodronate failed to kill bona fide SCs generated in vitro by genotoxic stress. Old mice with elevated proportion of p16(Ink4a)/β-gal(pH6)-positive cells in their tissues demonstrated reduction of both following systemic clodronate treatment, indicating that a significant proportion of cells previously considered to be SCs are actually a subclass of macrophages. These observations point at a significant role of p16(Ink4a)/β-gal(pH6)-positive macrophages in aging, which previously was attributed solely to SCs. They require re-interpretation of the mechanisms underlying rejuvenating effects following eradication of p16(Ink4a)/β-gal(pH6)-positive cells and reconsideration of potential cellular target for anti-aging treatment.

Xeroderma pigmentosum neurological abnormalities correlate with colony-forming ability after ultraviolet radiation

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

Andrews, A.D.; Barrett, S.F.; Robbins, J.H.

1978-04-01

Xeroderma pigmentosum is an autosomal recessive disease in which DNA repair processes are defective. All xeroderma pigmentosum patients develop premature aging of sun exposed skin, and some develop neurological abnormalities due to premature death of nerve cells. Sensitivity to ultraviolet radiation of 24 xeroderma pigmentosum fibroblast strains was studied in vitro by measuring each strain's ability to divide and form colonies after irradiation. The most sensitive strains were derived from patients who had an early onset of neurological abnormalities; less sensitive strains were from patients with a later onset; and the most resistant strains were from patients without neurological abnormalities.more » The uv sensitivities of strains from each member of a sibling pair with xeroderma pigmentosum were identical, indicating that uv sensitivity of xeroderma pigmentosum strains is determined by the patient's inherited DNA repair defect. The results suggest that effective DNA repair is required to maintain the functional integrity of the human nervous system by preventing premature death of neurons.« less

Cell-mediated immunity in an ageing population.

PubMed Central

Girard, J P; Paychère, M; Cuevas, M; Fernandes, B

1977-01-01

Eight hundred and eighty patients hospitalized in a geriatric hospital were routinely tested with 2, 10, 30 and 100 i.u. tuberculin. Among these, fifty-four patients were selected on the basis of negative skin tests and absence of evident diseases interfering with the function of the immune apparatus. A battery of tests analysing cell-mediated immunity was applied to those fifty-four patients. It appears that elderly patients having a negative test to 100 i.u. tuberculin show very infrequent sensitization to three other thymus-dependent antigens. The capacity of this selected population to become sensitized to DNCB is poor (20%). Furthermore they exhibit a low per cent of peripheral blood T cells (36%) and a poor capacity to respond in vitro to mitogens such as PHA. Testing the in vitro response to a battery of antigens demonstrates a good correlation with the results of the skin tests. Finally the leucocytes of 25% of this selected population failed to produce LIF in vitro in the presence of PHA. These results suggest not only an absolute decrease in the population of circulating T lymphocytes in those elderly humans; but very likely, at least in some cases, a functional impairment of T cells. PMID:321161

Application of a whole blood mycobacterial growth inhibition assay to study immunity against Mycobacterium tuberculosis in a high tuberculosis burden population

PubMed Central

Smit, Erica; Erasmus, Mzwandile; Day, Jonathan; Makhethe, Lebohang; de Kock, Marwou; Hughes, E. Jane; van Rooyen, Michele; Stone, Lynnett; Hanekom, Willem; Brennan, Michael J.; Wallis, Robert S.; Hatherill, Mark; Scriba, Thomas J.

2017-01-01

The determinants of immunological protection against Mycobacterium tuberculosis (M.tb) infection in humans are not known. Mycobacterial growth inhibition assays have potential utility as in vitro surrogates of in vivo immunological control of M.tb. We evaluated a whole blood growth inhibition assay in a setting with high burden of TB and aimed to identify immune responses that correlate with control of mycobacterial growth. We hypothesized that individuals with underlying M.tb infection will exhibit greater M.tb growth inhibition than uninfected individuals and that children aged 4 to 12 years, an age during which TB incidence is curiously low, will also exhibit greater M.tb growth inhibition than adolescents or adults. Neither M.tb infection status, age of the study participants, nor M.tb strain was associated with differential control of mycobacterial growth. Abundance and function of innate or T cell responses were also not associated with mycobacterial growth. Our data suggest that this assay does not provide a useful measure of age-associated differential host control of M.tb infection in a high TB burden setting. We propose that universally high levels of mycobacterial sensitization (through environmental non-tuberculous mycobacteria and/or universal BCG vaccination) in persons from high TB burden settings may impart broad inhibition of mycobacterial growth, irrespective of M.tb infection status. This sensitization may mask the augmentative effects of mycobacterial sensitization on M.tb growth inhibition that is typical in low burden settings. PMID:28886145

Change in Photosystem II Photochemistry During Algal Growth Phases of Chlorella vulgaris and Scenedesmus obliquus.

PubMed

Oukarroum, Abdallah

2016-06-01

Sensitivity of photosynthetic processes towards environmental stress is used as a bioanalytical tool to evaluate the responses of aquatic plants to a changing environment. In this paper, change of biomass density, chlorophyll a fluorescence and photosynthetic parameters during growth phases of two microalgae Chlorella vulgaris and Scenedesmus obliquus were studied. The photosynthetic growth behaviour changed significantly with cell age and algae species. During the exponential phase of growth, the photosynthesis capacity reached its maximum and decreased in ageing algal culture during stationary phase. In conclusion, the chlorophyll a fluorescence OJIP method and the derived fluorescence parameters would be an accurate method for obtaining information on maximum photosynthetic capacities and monitoring algal cell growth. This will contribute to more understanding, for example, of toxic actions of pollutants in microalgae test.

An Early Sensitive Period Induces Long-Lasting Plasticity in the Honeybee Nervous System

PubMed Central

Grosso, Juan P.; Barneto, Jesica A.; Velarde, Rodrigo A.; Pagano, Eduardo A.; Zavala, Jorge A.; Farina, Walter M.

2018-01-01

The effect of early experiences on the brain during a sensitive period exerts a long-lasting influence on the mature individual. Despite behavioral and neural plasticity caused by early experiences having been reported in the honeybee Apis mellifera, the presence of a sensitive period in which associative experiences lead to pronounced modifications in the adult nervous system is still unclear. Laboratory-reared bees were fed with scented food within specific temporal windows and were assessed for memory retention, in the regulation of gene expression related to the synaptic formation and in the olfactory perception of their antennae at 17 days of age. Bees were able to retain a food-odor association acquired 5–8 days after emergence, but not before, and showed better retention than those exposed to an odor at 9–12 days. In the brain, the odor-rewarded experiences that occurred at 5–8 days of age boosted the expression levels of the cell adhesion proteins neurexin 1 (Nrx1) and neuroligin 2 (Nlg2) involved in synaptic strength. At the antennae, the experiences increased the electrical response to a novel odor but not to the one experienced. Therefore, a sensitive period that induces long-lasting behavioral, functional and structural changes is found in adult honeybees. PMID:29449804

An Early Sensitive Period Induces Long-Lasting Plasticity in the Honeybee Nervous System.

PubMed

Grosso, Juan P; Barneto, Jesica A; Velarde, Rodrigo A; Pagano, Eduardo A; Zavala, Jorge A; Farina, Walter M

2018-01-01

The effect of early experiences on the brain during a sensitive period exerts a long-lasting influence on the mature individual. Despite behavioral and neural plasticity caused by early experiences having been reported in the honeybee Apis mellifera , the presence of a sensitive period in which associative experiences lead to pronounced modifications in the adult nervous system is still unclear. Laboratory-reared bees were fed with scented food within specific temporal windows and were assessed for memory retention, in the regulation of gene expression related to the synaptic formation and in the olfactory perception of their antennae at 17 days of age. Bees were able to retain a food-odor association acquired 5-8 days after emergence, but not before, and showed better retention than those exposed to an odor at 9-12 days. In the brain, the odor-rewarded experiences that occurred at 5-8 days of age boosted the expression levels of the cell adhesion proteins neurexin 1 ( Nrx1 ) and neuroligin 2 ( Nlg2 ) involved in synaptic strength. At the antennae, the experiences increased the electrical response to a novel odor but not to the one experienced. Therefore, a sensitive period that induces long-lasting behavioral, functional and structural changes is found in adult honeybees.

Insulin sensitivity and beta-cell function after carbohydrate oral loading in hip replacement surgery: a double-blind, randomised controlled clinical trial.

PubMed

Ljunggren, Stefan; Hahn, Robert G; Nyström, Thomas

2014-06-01

Surgery initiates a series of physiological stress processes in the body, inducing transient insulin resistance. Preoperative carbohydrate treatment can reduce the latter phenomenon. We investigated the effects of carbohydrate loading on insulin sensitivity and beta-cell function after elective hip replacement. Twenty-three nondiabetic patients (mean age of 68 years) who underwent elective hip replacement surgery participated in this double-blind controlled study. The patients were randomised to a nutrition group, which ingested a carbohydrate-rich fluid (50 kcal/100 ml) (Preop(®)), or a control group (tap water flavoured with lemon) 800 ml + 400 ml before the surgery. The insulin response (beta-cell function) and the insulin sensitivity were measured with an intravenous glucose tolerance test (IVGTT) and a hyperinsulinaemic euglycaemic glucose clamp, respectively, one day before and two days after the surgery. Insulin sensitivity decreased by 51% (median; 25-75th percentiles 35-61) after ingesting Preop(®) and by 39% (21-51) after ingesting in the control group (n.s.). The postoperative IVGTT in the nutrition group was followed by a significantly larger area under the curve (AUC) for plasma insulin (+54% versus the preoperative IVGTT) compared to the control group (+7%). This difference was already apparent during the first phase (0-10 min) of insulin secretion (+20 and -21%, respectively; P < 0.05). The patients randomised to the carbohydrate oral fluid or the water prior to the surgery demonstrated a significant but similar decrease in insulin sensitivity. The carbohydrates increased the beta-cell function as a compensatory response to the disposition index, resulting in a smaller reduction in surgery-induced insulin resistance compared to the tap water. The study was registered at http://www.clinicaltrials.gov (NCT01774084). Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Early life rhinovirus wheezing, allergic sensitization, and asthma risk at adolescence.

PubMed

Rubner, Frederick J; Jackson, Daniel J; Evans, Michael D; Gangnon, Ronald E; Tisler, Christopher J; Pappas, Tressa E; Gern, James E; Lemanske, Robert F

2017-02-01

Early life rhinovirus (RV) wheezing illnesses and aeroallergen sensitization increase the risk of asthma at school age. Whether these remain risk factors for the persistence of asthma out to adolescence is not established. We sought to define the relationships among specific viral illnesses and the type and timing of aeroallergen sensitization with the persistence of asthma into adolescence. A total of 217 children were followed prospectively from birth to age 13 years. The etiology and timing of viral wheezing illnesses during the first 3 years of life were assessed along with patterns of allergen sensitization. The associations between viral wheezing illnesses, presence and pattern of aeroallergen sensitization, and asthma diagnosis at age 13 years were evaluated. When adjusted for all viral etiologies, wheezing with RV (odds ratio = 3.3; 95% CI, 1.5-7.1), but not respiratory syncytial virus (odds ratio = 1.0; 95% CI, 0.4-2.3), was associated with asthma at age 13 years. Age of aeroallergen sensitization also influenced asthma risk; 65% of children sensitized by age 1 year had asthma at age 13 years, compared with 40% of children not sensitized at age 1 year but sensitized by age 5 years, and 17% of children not sensitized at age 5 years. Early life aeroallergen sensitization and RV wheezing had additive effects on asthma risk at adolescence. In a high-risk birth cohort, the persistence of asthma at age 13 years was most strongly associated with outpatient wheezing illnesses with RV and aeroallergen sensitization in early life. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Metabolomic Profiling of Amino Acids and β-Cell Function Relative to Insulin Sensitivity in Youth

PubMed Central

Michaliszyn, Sara F.; Sjaarda, Lindsey A.; Mihalik, Stephanie J.; Lee, SoJung; Bacha, Fida; Chace, Donald H.; De Jesus, Victor R.; Vockley, Jerry

2012-01-01

Context: In longitudinal studies of adults, elevated amino acid (AA) concentrations predicted future type 2 diabetes mellitus (T2DM). Objective: The aim of the present investigation was to examine whether increased plasma AA concentrations are associated with impaired β-cell function relative to insulin sensitivity [i.e. disposition index (DI)], a predictor of T2DM development. Design, Setting, and Participants: Metabolomic analysis for fasting plasma AAs was performed by tandem mass spectrometry in 139 normal-weight and obese adolescents with and without dysglycemia. First-phase insulin secretion was evaluated by a hyperglycemic (∼225 mg/dl) clamp and insulin sensitivity by a hyperinsulinemic-euglycemic clamp. DI was calculated as the product of first-phase insulin and insulin sensitivity. Results: DI was positively associated with branched-chain AAs (leucine/isoleucine and valine; r = 0.27 and 0.29, P = 0.001), neutrally transported AAs (phenylalanine and methionine; r = 0.30 and 0.35, P < 0.001), basic AAs (histidine and arginine; r = 0.28 and 0.23, P ≤ 0.007), serine (r = 0.35, P < 0.001), glycine (r = 0.26, P = 0.002), and branched-chain AAs-derived intermediates C3, C4, and C5 acylcarnitine (range r = 0.18–0.19, P ≤ 0.04). Conclusion: In youth, increased plasma AA concentrations are not associated with a heightened metabolic risk profile for T2DM; rather, they are positively associated with β-cell function relative to insulin sensitivity. These contrasting observations between adults and youth may be a reflection of developmental differences along the lifespan dependent on the combined impact of the aging process together with the impact of progressive obesity. PMID:22977272

Effects of Exenatide Plus Rosiglitazone on β-Cell Function and Insulin Sensitivity in Subjects With Type 2 Diabetes on Metformin

PubMed Central

DeFronzo, Ralph A.; Triplitt, Curtis; Qu, Yongming; Lewis, Michelle S.; Maggs, David; Glass, Leonard C.

2010-01-01

OBJECTIVE Study the effects of exenatide (EXE) plus rosiglitazone (ROSI) on β-cell function and insulin sensitivity using hyperglycemic and euglycemic insulin clamp techniques in participants with type 2 diabetes on metformin. RESEARCH DESIGN AND METHODS In this 20-week, randomized, open-label, multicenter study, participants (mean age, 56 ± 10 years; weight, 93 ± 16 kg; A1C, 7.8 ± 0.7%) continued their metformin regimen and received either EXE 10 μg b.i.d. (n = 45), ROSI 4 mg b.i.d. (n = 45), or EXE 10 μg b.i.d. + ROSI 4 mg b.i.d. (n = 47). Seventy-three participants underwent clamp procedures to quantitate insulin secretion and insulin sensitivity. RESULTS A1C declined in all groups (P < 0.05), but decreased most with EXE+ROSI (EXE+ROSI, −1.3 ± 0.1%; ROSI, −1.0 ± 0.1%, EXE, −0.9 ± 0.1%; EXE+ROSI vs. EXE or ROSI, P < 0.05). ROSI resulted in weight gain, while EXE and EXE+ROSI resulted in weight loss (EXE, −2.8 ± 0.5 kg; EXE+ROSI, −1.2 ± 0.5 kg; ROSI, + 1.5 ± 0.5 kg; P < 0.05 between and within all groups). At week 20, 1st and 2nd phase insulin secretion was significantly higher in EXE and EXE+ROSI versus ROSI (both P < 0.05). Insulin sensitivity (M value) was significantly higher in EXE+ROSI versus EXE (P = 0.014). CONCLUSIONS Therapy with EXE+ROSI offset the weight gain observed with ROSI and elicited an additive effect on glycemic control with significant improvements in β-cell function and insulin sensitivity. PMID:20107105

Effects of periodontal therapy on C-reactive protein and HDL in serum of subjects with periodontitis.

PubMed

Leite, Anne Carolina Eleutério; Carneiro, Valéria Martins de Araújo; Guimarães, Maria do Carmo Machado

2014-01-01

To investigate the effects of nonsurgical periodontal therapy on levels of high-sensitivity C-reactive protein in the sera and its association with body mass index and high density lipoprotein in subjects with severe periodontitis. Sera from 28 subjects (mean age: 34.36±6.24; 32% men) with severe periodontitis and 27 healthy controls (mean age: 33.18±6.42; 33% men) were collected prior to periodontal therapy. Blood samples were obtained from 23 subjects who completed therapy (9-12 months). Oral and systemic parameters such as the number of blood cells, glucose examination, lipid profile, and high-sensitivity C-reactive protein levels accessed by high-sensitivity immunonephelometry assay, were included. Before therapy, in the periodontitis group, the ratio of subjects with high-sensitivity C-reactive protein <0.3 mg/dL was statistically lower than in the control group (P<0.0216). After therapy, the ratio of subjects with high-sensitivity C-reactive protein <0.3 mg/dL was significantly higher (65.22%) (P<0.0339). The mean value for body mass index was statistically lower in subjects with high-sensitivity C-reactive protein <0.3 mg/dL (24.63±4.19), compared with those with high-sensitivity C-reactive protein >0.3 mg/dL (28.91±6.03) (P<0.0411). High density lipoprotein presented a mean value statistically higher after therapy (P<0.0027). In systemically healthy subjects with periodontitis, periodontal therapy was associated with decreased levels of circulating high-sensitivity C-reactive protein and increase of high density lipoprotein in serum. The clinical trial was registered at http://www.clinicaltrials.gov.br/, No. RBR-24T799.

[Abnormality of blood coagulation indexes in patients with de novo acute leukemia and its clinical significance].

PubMed

Xiao, Fang-Fang; Hu, Kai-Xun; Guo, Mei; Qiao, Jian-Hui; Sun, Qi-Yun; Ai, Hui-Sheng; Yu, Chang-Lin

2013-04-01

To explore hemorrhage risk and the clinical significance of abnormal change of prothrombin time (PT), activated partial thromboplastin time (APTT), plasma fibrinogen (FIB), plasma thrombin time (TT) and d-dimer (D-D) in de novo acute leukemia (except for APL), the different bleeding manifestations of 114 cases of de novo acute leukemia with different coagulation indexes were analyzed retrospectively. The correlation between these blood coagulation indexes and the possible correlative clinical characteristics were analysed, including age, sex, type of acute leukemia, initial white blood cell(WBC) and platelet(Plt) count, the proportion of blast cells in bone marrow and cytogenetic abnormality of patients at diagnosis. The results indicated that the incidence of abnormal blood coagulation was as high as 78.1% for de novo AL patients. These patients with 5 normal blood coagulation indexes may have mild bleeding manifestation, but the more abnormal indexes, the more severe bleeding. Both PT and D-D were sensitive indexes for diagnosis of level II bleeding. Incidence of abnormal blood coagulation significantly correlates with the proportion of blast cells in bone marrow (χ(2) = 4.184, OR = 1.021, P < 0.05) and more with D-D (P < 0.01), while age, sex, type of AL, WBC count, Plt count and abnormality of cytogenetics did not correlate with abnormal blood coagulation. It is concluded that the coagulation and fibrinolysis are abnormal in most patients with de novo acute leukemia. More abnormal indexes indicate more severe bleeding, and both PT and D-D are sensitive indexes for diagnosis of level II bleeding. Higher proportion of blast cells in bone marrow predicts higher incidence of abnormal blood clotting. Acute leukemia with elderly age, high white blood cell count and adverse cytogenetics do not predict severer abnormal blood clotting. Detection of PT, APTT, TT, FIB, and D-D may help to judge whether the patients are in a state of hypercoagulability or disseminated intravenous coagulation, which will provide experiment evidences for early intervention and medication.

Azelaic Acid Exerts Antileukemic Activity in Acute Myeloid Leukemia

PubMed Central

Pan, Yunbao; Liu, Dong; Wei, Yongchang; Su, Dan; Lu, Chenyang; Hu, Yanchao; Zhou, Fuling

2017-01-01

Acute myeloid leukemia (AML) is an acute leukemia common in most adults; its prevalence intensifies with age. The overall survival of AML is very poor because of therapeutic resistance. Azelaic acid (AZA) is non-toxic, non-teratogenic, and non-mutagenic and its antitumor effect on various tumor cells is well established; Nonetheless, its therapeutic effects in AML cells are largely unknown. In this study, it was shown that AZA significantly inhibits the cell viability and induces apoptosis in AML cells in a dose-dependent manner. Additionally, AZA suppressed the expression of phosphorylated Akt, Jab1 and Trx, and this suppression was enhanced by treatment with Jab1 siRNA. Furthermore, AZA sensitized AML cells to Ara-c chemotherapy. The suppressive effect of AZA on tumor growth was examined in vivo by subcutaneously inoculated AML cells in a tumor model using nude mice. These findings indicate that AZA is useful as an effective ingredient in antineoplastic activity. PMID:28659796

Azelaic Acid Exerts Antileukemic Activity in Acute Myeloid Leukemia.

PubMed

Pan, Yunbao; Liu, Dong; Wei, Yongchang; Su, Dan; Lu, Chenyang; Hu, Yanchao; Zhou, Fuling

2017-01-01

Acute myeloid leukemia (AML) is an acute leukemia common in most adults; its prevalence intensifies with age. The overall survival of AML is very poor because of therapeutic resistance. Azelaic acid (AZA) is non-toxic, non-teratogenic, and non-mutagenic and its antitumor effect on various tumor cells is well established; Nonetheless, its therapeutic effects in AML cells are largely unknown. In this study, it was shown that AZA significantly inhibits the cell viability and induces apoptosis in AML cells in a dose-dependent manner. Additionally, AZA suppressed the expression of phosphorylated Akt, Jab1 and Trx, and this suppression was enhanced by treatment with Jab1 siRNA. Furthermore, AZA sensitized AML cells to Ara-c chemotherapy. The suppressive effect of AZA on tumor growth was examined in vivo by subcutaneously inoculated AML cells in a tumor model using nude mice. These findings indicate that AZA is useful as an effective ingredient in antineoplastic activity.

A human life-stage physiologically based pharmacokinetic and pharmacodynamic model for chlorpyrifos: development and validation.

PubMed

Smith, Jordan Ned; Hinderliter, Paul M; Timchalk, Charles; Bartels, Michael J; Poet, Torka S

2014-08-01

Sensitivity to some chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to predict disposition of chlorpyrifos and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, previously measured age-dependent metabolism of chlorpyrifos and chlorpyrifos-oxon were integrated into age-related descriptions of human anatomy and physiology. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ⩾0.6mg/kg of chlorpyrifos (100- to 1000-fold higher than environmental exposure levels), 6months old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent doses. At lower doses more relevant to environmental exposures, simulations predict that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict chlorpyrifos disposition and biological response over various postnatal life stages. Copyright © 2013 Elsevier Inc. All rights reserved.

Salinomycin sensitizes antimitotic drugs-treated cancer cells by increasing apoptosis via the prevention of G2 arrest

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

Kim, Ju-Hwa; Yoo, Hye-In; Kang, Han Sung

Highlights: Black-Right-Pointing-Pointer Sal sensitizes antimitotic drugs-treated cancer cells. Black-Right-Pointing-Pointer Sal sensitizes them by prevention of G2 arrest and reduced cyclin D1 levels. Black-Right-Pointing-Pointer Sal also sensitizes them by increasing DNA damage and reducing p21 level. Black-Right-Pointing-Pointer A low concentration of Sal effectively sensitized the cancer cells to antimitotic drugs. -- Abstract: Here, we investigated whether Sal could sensitize cancer cells to antimitotic drugs. We demonstrated that Sal sensitized paclitaxcel (PAC)-, docetaxcel (DOC)-, vinblastin (VIN)-, or colchicine (COL)-treated cancer cell lines, suggesting that Sal has the ability to sensitize the cells to any form of microtubule-targeting drugs. Sensitization to the antimitoticmore » drugs could be achieved with very low concentrations of Sal, suggesting that there is a possibility to minimize Sal toxicity associated with human cancer patient treatments. Sensitization by Sal increased apoptosis, which was observed by C-PARP production. Sal sensitized the cancer cells to antimitotic drugs by preventing G2 arrest, suggesting that Sal contributes to the induction of mitotic catastrophe. Sal generally reduced cyclin D1 levels in PAC-, DOC-, and VIN-treated cells. In addition, Sal treatment increased pH2AX levels and reduced p21 levels in antimitotic drugs-treated cells. These observations suggest that the mechanisms underlying Sal sensitization to DNA-damaging compounds, radiation, and microtubule-targeting drugs are similar. Our data demonstrated that Sal sensitizes cancer cells to antimitotic drugs by increasing apoptosis through the prevention of G2 arrest via conserved Sal-sensitization mechanisms. These results may contribute to the development of Sal-based chemotherapy for cancer patients treated with antimitotic drugs.« less

Ageing sensitized by iPLA2β deficiency induces liver fibrosis and intestinal atrophy involving suppression of homeostatic genes and alteration of intestinal lipids and bile acids.

PubMed

Jiao, Li; Gan-Schreier, Hongying; Zhu, Xingya; Wei, Wang; Tuma-Kellner, Sabine; Liebisch, Gerhard; Stremmel, Wolfgang; Chamulitrat, Walee

2017-12-01

Ageing is a major risk factor for various forms of liver and gastrointestinal (GI) disease and genetic background may contribute to the pathogenesis of these diseases. Group VIA phospholipase A2 or iPLA 2 β is a homeostatic PLA 2 by playing a role in phospholipid metabolism and remodeling. Global iPLA 2 β -/- mice exhibit aged-dependent phenotypes with body weight loss and abnormalities in the bone and brain. We have previously reported the abnormalities in these mutant mice showing susceptibility for chemical-induced liver injury and colitis. We hypothesize that iPLA 2 β deficiency may sensitize with ageing for an induction of GI injury. Male wild-type and iPLA 2 β -/- mice at 4 and 20-22months of age were studied. Aged, but not young, iPLA 2 β -/- mice showed increased hepatic fibrosis and biliary ductular expansion as well as severe intestinal atrophy associated with increased apoptosis, pro-inflammation, disrupted tight junction, and reduced number of mucin-containing globlet cells. This damage was associated with decreased expression of intestinal endoplasmic stress XBP1 and its regulator HNF1α, FATP4, ACSL5, bile-acid transport genes as well as nuclear receptors LXRα and FXR. By LC/MS-MS profiling, iPLA 2 β deficiency in aged mice caused an increase of intestinal arachidonate-containing phospholipids concomitant with a decrease in ceramides. By the suppression of intestinal FXR/FGF-15 signaling, hepatic bile-acid synthesis gene expression was increased leading to an elevation of secondary and hydrophobic bile acids in liver, bile, and intestine. In conclusions, ageing sensitized by iPLA 2 β deficiency caused a decline of key intestinal homeostatic genes resulting in the development of GI disease in a gut-to-liver manner. Copyright © 2017 Elsevier B.V. All rights reserved.

Field comparison of optical and clark cell dissolved-oxygen sensors

USGS Publications Warehouse

Fulford, J.M.; Davies, W.J.; Garcia, L.

2005-01-01

Three multi-parameter water-quality monitors equipped with either Clark cell type or optical type dissolved-oxygen sensors were deployed for 30 days in a brackish (salinity <10 parts per thousand) environment to determine the sensitivity of the sensors to biofouling. The dissolved-oxygen sensors compared periodically to a hand-held dissolved oxygen sensor, but were not serviced or cleaned during the deployment. One of the Clark cell sensors and the optical sensor performed similarly during the deployment. The remaining Clark cell sensor was not aged correctly prior to deployment and did not perform as well as the other sensors. All sensors experienced substantial biofouling that gradually degraded the accuracy of the dissolved-oxygen measurement during the last half of the deployment period. Copyright ASCE 2005.

Are newborn rat-derived neural stem cells more sensitive to lead neurotoxicity?★

PubMed Central

Chan, Yan Ho; Gao, Mingyong; Wu, Wutian

2013-01-01

Lead ion (Pb2+) has been proven to be a neurotoxin due to its neurotoxicity on mammalian nervous system, especially for the developing brains of juveniles. However, many reported studies involved the negative effects of Pb2+ on adult neural cells of humans or other mammals, only few of which have examined the effects of Pb2+ on neural stem cells. The purpose of this study was to reveal the biological effects of Pb2+ from lead acetate [Pb (CH3COO)2] on viability, proliferation and differentiation of neural stem cells derived from the hippocampus of newborn rats aged 7 days and adult rats aged 90 days, respectively. This study was carried out in three parts. In the first part, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT viability assay) was used to detect the effects of Pb2+ on the cell viability of passage 2 hippocampal neural stem cells after 48-hour exposure to 0–200 μM Pb2+. In the second part, 10 μM bromodeoxyuridine was added into the culture medium of passage 2 hippocampal neural stem cells after 48-hour exposure to 0–200 μM Pb2+, followed by immunocytochemical staining with anti-bromodeoxyuridine to demonstrate the effects of Pb2+ on cell proliferation. In the last part, passage 2 hippocampal neural stem cells were allowed to grow in the differentiation medium with 0–200 μM Pb2+. Immunocytochemical staining with anti-microtubule-associated protein 2 (a neuron marker), anti-glial fibrillary acidic protein (an astrocyte marker), and anti-RIP (an oligodendrocyte marker) was performed to detect the differentiation commitment of affected neural stem cells after 6 days. The data showed that Pb2+ inhibited not only the viability and proliferation of rat hippocampal neural stem cells, but also their neuronal and oligodendrocyte differentiation in vitro. Moreover, increased activity of astrocyte differentiation of hippocampal neural stem cells from both newborn and adult rats was observed after exposure to high concentration of lead ion in vitro. These findings suggest that hippocampal neural stem cells of newborn rats were more sensitive than those from adult rats to Pb2+ cytotoxicity. PMID:25206702

Comparison of the peripheral blood leukocyte population between Japanese Black and Holstein calves.

PubMed

Ohtsuka, Hiromichi; Ono, Maiko; Saruyama, Yumi; Mukai, Machiko; Kohiruimaki, Masayuki; Kawamura, Seiichi

2011-02-01

Japanese black (JB) calves have greater susceptibility to infectious diseases compared to Holstein (Hol) calves. In order to clarify the differences in cellular immune status between JB and Hol calves, the leukocyte population and lymphocyte proliferative ability were analyzed. In total 200 healthy calves, 1 day to 14 weeks of age, were examined: 105 JB and 95 Hol calves. Lower numbers in peripheral blood and percentage in peripheral blood mononuclear cells of CD3(+)TcR1-N12(+) T cells and major histocompatibility complex class-II(+)CD14(-) B cells were observed in the JB compared to the Hol. The percentage of TcR1-N12(+)CD25(+) T cell in the JB was significantly lower than that of the Hol at 4-6, and 8-10 weeks. Interleukin (IL)-2 sensitivity in the JB was lower than that in the Hol, and significant differences were observed in age groups of 6-8 weeks and 10-14 weeks. These findings indicated that the lower numbers of γδ T cells and B cells in the JB compared to the Hol might be associated with the specificity of the immune systems in JB calves. © 2011 The Authors. Journal compilation © 2011 Japanese Society of Animal Science.

IGF1R signalling in testicular germ cell tumour cells impacts on cell survival and acquired cisplatin resistance.

PubMed

Selfe, Joanna; Goddard, Neil C; McIntyre, Alan; Taylor, Kathryn R; Renshaw, Jane; Popov, Sergey D; Thway, Khin; Summersgill, Brenda; Huddart, Robert A; Gilbert, Duncan C; Shipley, Janet M

2018-02-01

Testicular germ cell tumours (TGCTs) are the most frequent malignancy and cause of death from solid tumours in the 20- to 40-year age group. Although most cases show sensitivity to cis-platinum-based chemotherapy, this is associated with long-term toxicities and chemo-resistance. Roles for receptor tyrosine kinases other than KIT are largely unknown in TGCT. We therefore conducted a phosphoproteomic screen and identified the insulin growth factor receptor-1 (IGF1R) as both highly expressed and activated in TGCT cell lines representing the nonseminomatous subtype. IGF1R was also frequently expressed in tumour samples from patients with nonseminomas. Functional analysis of cell line models showed that long-term shRNA-mediated IGF1R silencing leads to apoptosis and complete ablation of nonseminoma cells with active IGF1R signalling. Cell lines with high levels of IGF1R activity also showed reduced AKT signalling in response to decreased IGF1R expression as well as sensitivity to the small-molecule IGF1R inhibitor NVP-AEW541. These results were in contrast to those in the seminoma cell line TCAM2 that lacked IGF1R signalling via AKT and was one of the two cell lines least sensitive to the IGF1R inhibitor. The dependence on IGF1R activity in the majority of nonseminomas parallels the known role of IGF signalling in the proliferation, migration, and survival of primordial germ cells, the putative cell of origin for TGCT. Upregulation of IGF1R expression and signalling was also found to contribute to acquired cisplatin resistance in an in vitro nonseminoma model, providing a rationale for targeting IGF1R in cisplatin-resistant disease. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Effects of aging on resistance to Trichinella spiralis infection in rodents exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

PubMed

Luebke, R W; Copeland, C B; Andrews, D L

1999-08-13

Immune function, including resistance to infection, decreases as humans and rodents age. We have shown that preinfection exposure of young (9-11 weeks) mice or rats to TCDD decreased resistance to Trichinella spiralis (Ts) infection, expressed as delayed onset or completion of parasite elimination and as increased muscle burdens of larvae. It has also been shown that aged mice express lower constitutive levels of resistance to Ts infection, compared to young adult animals. This study tested the hypothesis that the age-related decrease in constitutive levels of resistance to Ts infection exacerbates the decreased resistance to infection that follows TCDD exposure. This hypothesis addresses the concern that TCDD may pose a greater threat to the elderly than to the population at large. Animals were given a single oral dose of 1, 10, or 30 microg TCDD/kg, 7 days before infection. Eleven days later, young (approximately 10 weeks) control rodents had eliminated a greater proportion of the original parasite burden from the intestine than aged control animals. Nevertheless, parasite elimination was decreased by TCDD exposure only in young rodents. The effect of TCDD exposure on numbers of encysted larvae was evaluated only in rats. Increased larvae burdens occurred in young rats at 30 microg TCDD/kg and at 10 or 30 microg TCDD/kg in aged rats. Parasite-specific splenocyte and lymph node cell proliferation was suppressed following dioxin exposure in young mice; cells from aged mice were markedly less responsive to stimulation, yet less sensitive to TCDD exposure. The response to parasite antigens was not affected in aged rats exposed to TCDD, although elevated mitogen-driven B-cell proliferation was observed. These results indicate that age-related constitutive immunosuppression did not exacerbate TCDD-induced suppression of T-cell mediated adult parasite expulsion; rather, advanced age provided some degree of protection. On the other hand, a lower dose of TCDD was required in aged rats to suppress the combined humoral and cellular responses that limit the burden of encysted larvae, compared to young rats. These model-dependent results preclude acceptance or rejection of the tested hypothesis.

Sustained NFκB inhibition improves insulin sensitivity but is detrimental to muscle health.

PubMed

Zhang, Ning; Valentine, Joseph M; Zhou, You; Li, Mengyao E; Zhang, Yiqiang; Bhattacharya, Arunabh; Walsh, Michael E; Fischer, Katherine E; Austad, Steven N; Osmulski, Pawel; Gaczynska, Maria; Shoelson, Steven E; Van Remmen, Holly; Chen, Hung I; Chen, Yidong; Liang, Hanyu; Musi, Nicolas

2017-08-01

Older adults universally suffer from sarcopenia and approximately 60-70% are diabetic or prediabetic. Nonetheless, the mechanisms underlying these aging-related metabolic disorders are unknown. NFκB has been implicated in the pathogenesis of several aging-related pathologies including sarcopenia and type 2 diabetes and has been proposed as a target against them. NFκB also is thought to mediate muscle wasting seen with disuse, denervation, and some systemic diseases (e.g., cancer, sepsis). We tested the hypothesis that lifelong inhibition of the classical NFκB pathway would protect against aging-related sarcopenia and insulin resistance. Aged mice with muscle-specific overexpression of a super-repressor IκBα mutant (MISR) were protected from insulin resistance. However, MISR mice were not protected from sarcopenia; to the contrary, these mice had decreases in muscle mass and strength compared to wild-type mice. In MISR mice, NFκB suppression also led to an increase in proteasome activity and alterations in several genes and pathways involved in muscle growth and atrophy (e.g., myostatin). We conclude that the mechanism behind aging-induced sarcopenia is NFκB independent and differs from muscle wasting due to pathologic conditions. Our findings also indicate that, while suppressing NFκB improves insulin sensitivity in aged mice, this transcription factor is important for normal muscle mass maintenance and its sustained inhibition is detrimental to muscle function. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Dissecting Long-Term Glucose Metabolism Identifies New Susceptibility Period for Metabolic Dysfunction in Aged Mice

PubMed Central

Koch, Franziska; Ibrahim, Saleh M.; Vera, Julio; Wolkenhauer, Olaf; Tiedge, Markus

2015-01-01

Metabolic disorders, like diabetes and obesity, are pathogenic outcomes of imbalance in glucose metabolism. Nutrient excess and mitochondrial imbalance are implicated in dysfunctional glucose metabolism with age. We used conplastic mouse strains with defined mitochondrial DNA (mtDNA) mutations on a common nuclear genomic background, and administered a high-fat diet up to 18 months of age. The conplastic mouse strain B6-mtFVB, with a mutation in the mt-Atp8 gene, conferred β-cell dysfunction and impaired glucose tolerance after high-fat diet. To our surprise, despite of this functional deficit, blood glucose levels adapted to perturbations with age. Blood glucose levels were particularly sensitive to perturbations at the early age of 3 to 6 months. Overall the dynamics consisted of a peak between 3–6 months followed by adaptation by 12 months of age. With the help of mathematical modeling we delineate how body weight, insulin and leptin regulate this non-linear blood glucose dynamics. The model predicted a second rise in glucose between 15 and 21 months, which could be experimentally confirmed as a secondary peak. We therefore hypothesize that these two peaks correspond to two sensitive periods of life, where perturbations to the basal metabolism can mark the system for vulnerability to pathologies at later age. Further mathematical modeling may perspectively allow the design of targeted periods for therapeutic interventions and could predict effects on weight loss and insulin levels under conditions of pre-diabetic obesity. PMID:26540285

Triage of women with atypical squamous cells of undetermined significance (ASC-US): results of an Italian multicentric study.

PubMed

Del Mistro, Annarosa; Frayle-Salamanca, Helena; Trevisan, Rossana; Matteucci, Mario; Pinarello, Antonella; Zambenedetti, Pamela; Buoso, Rita; Fantin, Gian Piero; Zorzi, Manuel; Minucci, Daria

2010-04-01

To compare the performance of immediate colposcopy, repeat Pap test and HPV test as triage options for women diagnosed as having atypical squamous cells of undetermined significance (ASC-US) while attending organised screening for cervical carcinoma in five centres of the Veneto region. Women consecutively diagnosed as having ASC-US were included in a prospective study, and underwent colposcopy and collection of cervico-vaginal cells for conventional Pap test and HPV test (Hybrid Capture 2, High-risk probe set, Digene). Repetition of all three tests was scheduled for 12 months later. DNA was subsequently extracted from residual cells of positive samples, and analysed by polymerase chain reaction with several primers for typing of HPV sequences. Sensitivity, specificity and positive predictive value (PPV) of the different triage options for histology-confirmed cervical intraepithelial neoplasia, grade 2 or worse (CIN2+) were calculated among all women and by age (under and above 35 years). Seven hundred forty-nine women 25-64 years old (median age 42 years) were enrolled in the study. Pap smears at enrolment were read as ASC-US or more severe in 211 (29.4%) cases, colposcopy disclosed an atypical transformation zone in 254 (34.2%) women, and HPV test was positive in 181 (24.2%). High-grade cervical lesions developed in 29/749 (3.9%) women. HPV typing was possible in 163 (90%) of the samples, and carcinogenic types were present in 123. HPV test showed the best performance; overall, it had the highest sensitivity (92.3%), specificity (78.6%) and PPV (14.9%). Copyright 2009 Elsevier Inc. All rights reserved.

Method for rapid isolation of sensitive mutants

DOEpatents

Freyer, James P.

1997-01-01

Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned.

Method for rapid isolation of sensitive mutants

DOEpatents

Freyer, J.P.

1997-07-29

Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned. 15 figs.

Reduced Expression of the Liver/Beta-Cell Glucose Transporter Isoform in Glucose-Insensitive Pancreatic Beta Cells of Diabetic Rats

NASA Astrophysics Data System (ADS)

Thorens, Bernard; Weir, Gordon C.; Leahy, John L.; Lodish, Harvey F.; Bonner-Weir, Susan

1990-09-01

Rats injected with a single dose of streptozocin at 2 days of age develop non-insulin-dependent diabetes 6 weeks later. The pancreatic beta islet cells of these diabetic rats display a loss of glucose-induced insulin secretion while maintaining sensitivity to other secretagogues such as arginine. We analyzed the level of expression of the liver/beta-cell glucose transporter isoform in diabetic islets by immunofluorescence staining of pancreas sections and by Western blotting of islet lysates. Islets from diabetic animals have a reduced expression of this beta-cell-specific glucose transporter isoform and the extent of reduction is correlated with the severity of hyperglycemia. In contrast, expression of this transporter isoform in liver is minimally modified by the diabetes. Thus a decreased expression of the liver/beta-cell glucose transporter isoform in beta cells is associated with the impaired glucose sensing characteristic of diabetic islets; our data suggest that this glucose transporter may be part of the beta-cell glucose sensor.

Effects of salinity on the transcriptome of growing maize leaf cells point at cell-age specificity in the involvement of the antioxidative response in cell growth restriction

PubMed Central

2013-01-01

Background Salinity inhibits growth and development of most plants. The response to salinity is complex and varies between plant organs and stages of development. It involves challenges of ion toxicities and deficiencies as well as osmotic and oxidative stresses. The range of functions affected by the stress is reflected in elaborate changes to the transcriptome. The mechanisms involved in the developmental-stage specificity of the inhibitory responses are not fully understood. The present study took advantage of the well characterized developmental progression that exists along the maize leaf, for identification of salinity induced, developmentally-associated changes to the transcriptome. Differential subtraction screening was conducted for cells of two developmental stages: from the center of the growth zone where the expansion rate is highest, and from older cells at a more distal location of the growing zone where the expansion rate is lower and the salinity restrictive effects are more pronounced. Real-Time PCR analysis was used for validation of the expression of selected genes. Results The salinity-induced changes demonstrated an age-related response of the growing tissue, with elevation of salinity-damages with increased age. Growth reduction, similar to the elevation of percentage dry matter (%DM), and Na and Cl concentrations were more pronounced in the older cells. The differential subtraction screening identified genes encoding to proteins involved in antioxidant defense, electron transfer and energy, structural proteins, transcription factors and photosynthesis proteins. Of special interest is the higher induced expression of genes involved in antioxidant protection in the young compared to older cells, which was accompanied by suppressed levels of reactive oxygen species (H2O2 and O2-). This was coupled with heightened expression in the older cells of genes that enhance cell-wall rigidity, which points at reduced potential for cell expansion. Conclusions The results demonstrate a cell-age specificity in the salinity response of growing cells, and point at involvement of the antioxidative response in cell growth restriction. Processes involved in reactive oxygen species (ROS) scavenging are more pronounced in the young cells, while the higher growth sensitivity of older cells is suggested to involve effects on cell-wall rigidity and lower protein protection. PMID:23324477

Plectin deficiency in liver cancer cells promotes cell migration and sensitivity to sorafenib treatment.

PubMed

Cheng, Chiung-Chi; Chao, Wei-Ting; Liao, Chen-Chun; Tseng, Yu-Hui; Lai, Yen-Chang Clark; Lai, Yih-Shyong; Hsu, Yung-Hsiang; Liu, Yi-Hsiang

2018-01-02

Plectin involved in activation of kinases in cell signaling pathway and plays important role in cell morphology and migration. Plectin knockdown promotes cell migration by activating focal adhesion kinase and Rac1-GTPase activity in liver cells. Sorafenib is a multi-targeting tyrosine kinase inhibitor that improves patient survival on hepatocellular carcinoma. The aim of this study is to investigate the correlation between the expression of plectin and cell migration as well as the sensitivity of hepatoma cell lines exposing to sorafenib. Hepatoma cell lines PLC/PRF/5 and HepG2 were used to examine the level of plectin expression and cell migration in comparison with Chang liver cell line. In addition, sensitivity of the 3 cell lines to sorafenib treatment was also measured. Expression of plectin was lower in PLC/PRF/5 and HepG2 hepatoma cells than that of Chang liver cells whereas HepG2 and PLC/PRF/5 cells exhibit higher rate of cell migration in trans-well migration assay. Immunohistofluorecent staining on E-cadherin revealed the highest rate of collective cell migration in HepG2 cells and the lowest was found in Chang liver cells. Likewise, HepG2 cell line was most sensitive to sorafenib treatment and Chang liver cells exhibited the least sensitivity. The drug sensitivity to sorafenib treatment showed inverse correlation with the expression of plectin. We suggest that plectin deficiency and increased E-cadherin in hepatoma cells were associated with higher rates of cell motility, collective cell migration as well as higher drug sensitivity to sorafenib treatment.

Bone mineral density, growth, pubertal development and other parameters in Brazilian children and young adults with sickle cell anaemia.

PubMed

Meeuwes, M; Souza de Carvalho, T F; Cipolotti, R; Gurgel, R Q; Ferrão, T O; Peters, M; Agyemang, C

2013-12-01

To evaluate the occurrence of low bone mineral density (BMD) and its relationship with clinical and laboratorial characteristics in children and young adults with sickle cell anaemia living in Northeast-Brazil, and to assess the role of radiography in diagnosing low BMD. Bone mineral density of lumbar spine was measured by dual energy X-ray absorptiometry (DXA) in 27 patients with Sickle cell anaemia (SCA) aged 7-28 years. Clinical history, calcium and calorie intake, laboratory measurements, anthropometrics and pubertal development were assessed, and X-rays were obtained. Z-scores and T-scores for weight, height, Body Mass Index (BMI) and BMD were calculated using age and gender matched reference data. Mean lumbar spine BMD Z-scores and T-scores were -1.81 SD in boys and -0.80 SD in girls. BMD Z-scores were below -2 SD in 33.3% of girls and in 46.7% of boys. Low BMD (<-2 SD) occurred significantly more in patients with low height-for-age (P = 0.02), low weight-for-age (P = 0.001) and low BMI-for-age (P = 0.006). No significant relationships were found between BMD and other clinical and laboratory parameters. Radiography had a sensitivity of 75% and a specificity of 36% to detect low BMD, and was considered not useful in this context. Patients with low height and/or low weight-for-age seem to be at high risk for developing low BMD. © 2013 John Wiley & Sons Ltd.

Evaluation of somatostatin receptors in large cell pulmonary neuroendocrine carcinoma with 99mTc-EDDA/HYNIC-TOC scintigraphy.

PubMed

Nocuń, Anna; Chrapko, Beata; Gołębiewska, Renata; Stefaniak, Bogusław; Czekajska-Chehab, Elżbieta

2011-06-01

Large cell pulmonary neuroendocrine carcinoma (LCNEC) is a poorly differentiated and high-grade neoplasm. It is positioned between an atypical carcinoid and small cell neuroendocrine carcinoma of the lung in a distinct family of pulmonary neuroendocrine tumors. The aim of our study was to detect somatostatin receptors in this uncommon malignancy and to evaluate the sensitivity of somatostatin receptor scintigraphy (SRS) in LCNEC staging. We analyzed data of 26 patients (mean age: 61.5±7.9 years) with histologically confirmed diagnosis of LCNEC, including 18 cases not treated surgically and eight patients after the resection of the primary tumor. SRS was carried out with technetium-99m ethylene diamine-diacetic acid/hydrazinonicotinyl-Tyr3-octreotide (Tc-TOC). A visual analysis of scintigraphic images was done with reference to conventional imaging modalities (computed tomography and bone sicintigraphy). SRS sensitivity for the detection of primary lesions, supradiaphragmatic metastases, and infradiaphragmatic metastases was 100, 83.3%, and 0%, respectively. Five out of 13 metastases to the liver appeared on SRS as photopenic foci, visible on the background of physiological hepatic activity. Only one of the nine metastases to the skeletal system was found by SRS with sensitivity as low as 11.1%. The overall SRS sensitivity for the detection of secondary lesions and of all lesions was 54.8 and 62.2%, respectively. Within a rather large series of LCNEC, the primary tumor showed an uptake of Tc-TOC in all cases, whereas some metastases did show Tc-TOC uptake and some others did not.

Factors affecting red blood cell storage age at the time of transfusion.

PubMed

Dzik, Walter H; Beckman, Neil; Murphy, Michael F; Delaney, Meghan; Flanagan, Peter; Fung, Mark; Germain, Marc; Haspel, Richard L; Lozano, Miguel; Sacher, Ronald; Szczepiorkowski, Zbigniew; Wendel, Silvano

2013-12-01

Clinical trials are investigating the potential benefit resulting from a reduced maximum storage interval for red blood cells (RBCs). The key drivers that determine RBC age at the time of issue vary among individual hospitals. Although progressive reduction in the maximum storage period of RBCs would be expected to result in smaller hospital inventories and reduced blood availability, the magnitude of the effect is unknown. Data on current hospital blood inventories were collected from 11 hospitals and three blood centers in five nations. A general predictive model for the age of RBCs at the time of issue was developed based on considerations of demand for RBCs in the hospital. Age of RBCs at issue is sensitive to the following factors: ABO group, storage age at the time of receipt by the hospital, the restock interval, inventory reserve, mean demand, and variation in demand. A simple model, based on hospital demand, may serve as the basis for examining factors affecting the storage age of RBCs in hospital inventories. The model suggests that the age of RBCs at the time of their issue to the patient depends on factors external to the hospital transfusion service. Any substantial change in the expiration date of stored RBCs will need to address the broad variation in demand for RBCs while attempting to balance considerations of availability and blood wastage. © 2013 American Association of Blood Banks.

Conserved features of cancer cells define their sensitivity of HAMLET-induced death; c-Myc and glycolysis

PubMed Central

Storm, Petter; Puthia, Manoj Kumar; Aits, Sonja; Urbano, Alexander; Northen, Trent; Powers, Scott; Bowen, Ben; Chao, Yinxia; Reindl, Wolfgang; Lee, Do Yup; Sullivan, Nancy Liu; Zhang, Jianping; Trulsson, Maria; Yang, Henry; Watson, James; Svanborg, Catharina

2014-01-01

HAMLET is the first member of a new family of tumoricidal protein-lipid complexes that kill cancer cells broadly, while sparing healthy, differentiated cells. Many and diverse tumor cell types are sensitive to the lethal effect, suggesting that HAMLET identifies and activates conserved death pathways in cancer cells. Here we investigated the molecular basis for the difference in sensitivity between cancer cells and healthy cells. Using a combination of small hairpin RNA inhibition, proteomic and metabolomic technology we identified the c-Myc oncogene as one essential determinant of HAMLET sensitivity. Increased c-Myc expression levels promoted the sensitivity to HAMLET and shRNA knockdown of c-Myc suppressed the lethal response, suggesting that oncogenic transformation with c-Myc creates a HAMLET-sensitive phenotype. Furthermore, the HAMLET sensitivity was modified by the glycolytic state of the tumor cells. Glucose deprivation sensitized tumor cells to HAMLET-induced cell death and in the shRNA screen Hexokinase 1, PFKFB1 and HIF1α modified HAMLET sensitivity. Hexokinase 1 was shown to bind HAMLET in a protein array containing approximately 8000 targets and Hexokinase activity decreased within 15 minutes of HAMLET treatment, prior to morphological signs of tumor cell death. In parallel, HAMLET triggered rapid metabolic paralysis in carcinoma cells. The glycolytic machinery was modified and glycolysis was shifted towards the pentose phosphate pathway. Tumor cells were also shown to contain large amounts of oleic acid and its derivatives already after 15 minutes. The results identify HAMLET as a novel anti-cancer agent that kills tumor cells by exploiting unifying features of cancer cells such as oncogene-addiction or the Warburg effect. PMID:21643007

Conserved features of cancer cells define their sensitivity to HAMLET-induced death; c-Myc and glycolysis.

PubMed

Storm, P; Aits, S; Puthia, M K; Urbano, A; Northen, T; Powers, S; Bowen, B; Chao, Y; Reindl, W; Lee, D Y; Sullivan, N L; Zhang, J; Trulsson, M; Yang, H; Watson, J D; Svanborg, C

2011-12-01

HAMLET is the first member of a new family of tumoricidal protein-lipid complexes that kill cancer cells broadly, while sparing healthy, differentiated cells. Many and diverse tumor cell types are sensitive to the lethal effect, suggesting that HAMLET identifies and activates conserved death pathways in cancer cells. Here, we investigated the molecular basis for the difference in sensitivity between cancer cells and healthy cells. Using a combination of small-hairpin RNA (shRNA) inhibition, proteomic and metabolomic technology, we identified the c-Myc oncogene as one essential determinant of HAMLET sensitivity. Increased c-Myc expression levels promoted sensitivity to HAMLET and shRNA knockdown of c-Myc suppressed the lethal response, suggesting that oncogenic transformation with c-Myc creates a HAMLET-sensitive phenotype. Furthermore, HAMLET sensitivity was modified by the glycolytic state of tumor cells. Glucose deprivation sensitized tumor cells to HAMLET-induced cell death and in the shRNA screen, hexokinase 1 (HK1), 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 1 and hypoxia-inducible factor 1α modified HAMLET sensitivity. HK1 was shown to bind HAMLET in a protein array containing ∼8000 targets, and HK activity decreased within 15 min of HAMLET treatment, before morphological signs of tumor cell death. In parallel, HAMLET triggered rapid metabolic paralysis in carcinoma cells. Tumor cells were also shown to contain large amounts of oleic acid and its derivatives already after 15 min. The results identify HAMLET as a novel anti-cancer agent that kills tumor cells by exploiting unifying features of cancer cells such as oncogene addiction or the Warburg effect.

Multiple cutaneous malignancies in a patient of xeroderma pigmentosum.

PubMed

Grampurohit, Vandana U; Dinesh, U S; Rao, Ravikala

2011-01-01

Xeroderma pigmentosum is a genodermatosis characterized by photosensitivity and the development of cutaneous and internal malignancies at an early age. The basic defect underlying the clinical manifestations is a nucleotide excision repair defect, leading to defective repair of DNA damaged by ultraviolet radiation. These patients exhibit enhanced sensitivity to ionizing radiation. Patients with xeroderma pigmentosum who are younger than 20 years of age have a greater than 1000-fold increased risk of developing skin cancer. Early detection of these malignancies is necessary because they are fast growing, metastasize early and lead to death. Although, early detection and treatment of cutaneous malignancies will reduce the morbidity and mortality, genetic counseling remains the most important measure for preventing xeroderma pigmentosum. We report a case of xeroderma pigmentosum in an 18-year-old male presenting with multiple cutaneous malignancies: squamous cell carcinoma, malignant melanoma and pigmented basal cell carcinoma.

Investigation of Strain Aging in the Ordered Intermetallic Compound beta-NiAl. Ph.D. Thesis Final Contractor Report

NASA Technical Reports Server (NTRS)

Weaver, Mark Lovell

1995-01-01

The phenomenon of strain aging has been investigated in polycrystalline and single crystal NiAl alloys at temperatures between 300 and 1200 K. Static strain aging studies revealed that after annealing at 1100 K for 7200 s (i.e., 2h) followed by furnace cooling, high purity, nitrogen-doped and titanium-doped polycrystalline alloys exhibited continuous yielding, while conventional-purity and carbon-doped alloys exhibited distinct yield points and Luders strains. Prestraining by hydrostatic pressurization removed the yield points, but they could be reintroduced by further annealing treatments. Yield points could be reintroduced more rapidly if the specimens were prestrained uniaxially rather than hydrostatically, owing to the arrangement of dislocations into cell structures during uniaxial deformation. The time dependence of the strain aging events followed at t(exp 2/3) relationship suggesting that the yield points observed in polycrystalline NiAl were the result of the pinning of mobile dislocations by interstitials, specifically carbon. Between 700 and 800 K, yield stress plateaus, yield stress transients upon a ten-fold increase in strain rate, work hardening peaks, and dips in the strain rate sensitivity (SRS) have been observed in conventional-purity and carbon-doped polycrystals. In single crystals, similar behavior was observed; in conventional-purity single crystals, however, the strain rate sensitivity became negative resulting in serrated yielding, whereas, the strain rate sensitivity stayed positive in high purity and in molybdenum-doped NiAl. These observations are indicative of dynamic strain aging (DSA) and are discussed in terms of conventional strain aging theories. The impact of these phenomena on the composition-structure-property relations are discerned. Finally, a good correlation has been demonstrated between the properties of NiAl alloys and a recently developed model for strain aging in metals and alloys developed by Reed-Hill et al.

The Relative Associations of β-Cell Function and Insulin Sensitivity with Glycemic Status and Incident Glycemic Progression in Migrant Asian Indians in the United States: the MASALA study

PubMed Central

Gujral, UP; Narayan, KMV; Kahn, SE; Kanaya, AM

2013-01-01

AIMS We assessed the relative associations of β-cell dysfunction and insulin sensitivity with baseline glycemic status and incident glycemic progression among Asian Indians in the United States. METHODS A 5-sample oral glucose tolerance test was obtained at baseline. Normoglycemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes (T2DM) were defined by ADA criteria. The Matsuda Index (ISIM) estimated insulin sensitivity, and the Disposition Index (DIo) estimated β-cell function. Visceral fat was measured by abdominal CT. After 2.5 years, participants underwent a 2-sample oral glucose tolerance test. Standardized polytomous logistic regression was used to examine associations with prevalent and incident glycemia. RESULTS Mean age was 57±8 years and BMI 26.1±4.6 kg/m2. Log ISIM and log DIo were associated with prediabetes and T2DM after adjusting for age, sex, BMI, family history of diabetes, hypertension, and smoking. After adjusting for visceral fat, only DIo remained associated with prediabetes (OR per SD 0.17, 95% CI: 0.70, 0.41) and T2DM (OR 0.003, 95% CI: 0.0001, 0.03). Incidence rates (per 1,000 person-year) were: normoglycemia to IGT: 82.0, 95% CI (40, 150); to IFG: 8.4, 95% CI (0, 41); to T2DM: 8.6, 95% CI (0, 42); IGT to T2DM: 55.0, 95% CI (17, 132); IFG to T2DM: 64.0, 95% CI (3, 316). The interaction between sex and the change in waist circumference (OR 1.8, per SD 95% CI: 1.22, 2.70) and the change in log HOMA-β(OR 0.37, per SD 95% CI: 0.17, 0.81) were associated with glycemic progression. CONCLUSIONS The association of DIo with baseline glycemia after accounting for visceral fat as well as the association of the change in log HOMA-β with incident glycemic progression implies innate β-cell susceptibility in Asian Indians for glucose intolerance or dysglycemia. PMID:24211090

The Biology of Pichia membranifaciens Killer Toxins

PubMed Central

Belda, Ignacio; Ruiz, Javier; Alonso, Alejandro; Marquina, Domingo; Santos, Antonio

2017-01-01

The killer phenomenon is defined as the ability of some yeast to secrete toxins that are lethal to other sensitive yeasts and filamentous fungi. Since the discovery of strains of Saccharomyces cerevisiae capable of secreting killer toxins, much information has been gained regarding killer toxins and this fact has substantially contributed knowledge on fundamental aspects of cell biology and yeast genetics. The killer phenomenon has been studied in Pichia membranifaciens for several years, during which two toxins have been described. PMKT and PMKT2 are proteins of low molecular mass that bind to primary receptors located in the cell wall structure of sensitive yeast cells, linear (1→6)-β-d-glucans and mannoproteins for PMKT and PMKT2, respectively. Cwp2p also acts as a secondary receptor for PMKT. Killing of sensitive cells by PMKT is characterized by ionic movements across plasma membrane and an acidification of the intracellular pH triggering an activation of the High Osmolarity Glycerol (HOG) pathway. On the contrary, our investigations showed a mechanism of killing in which cells are arrested at an early S-phase by high concentrations of PMKT2. However, we concluded that induced mortality at low PMKT2 doses and also PMKT is indeed of an apoptotic nature. Killer yeasts and their toxins have found potential applications in several fields: in food and beverage production, as biocontrol agents, in yeast bio-typing, and as novel antimycotic agents. Accordingly, several applications have been found for P. membranifaciens killer toxins, ranging from pre- and post-harvest biocontrol of plant pathogens to applications during wine fermentation and ageing (inhibition of Botrytis cinerea, Brettanomyces bruxellensis, etc.). PMID:28333108

Sickle Mice Are Sensitive to Hypoxia/Ischemia-Induced Stroke but Respond to Tissue-Type Plasminogen Activator Treatment.

PubMed

Sun, Yu-Yo; Lee, Jolly; Huang, Henry; Wagner, Mary B; Joiner, Clinton H; Archer, David R; Kuan, Chia-Yi

2017-12-01

The effects of lytic stroke therapy in patients with sickle cell anemia are unknown, although a recent study suggested that coexistent sickle cell anemia does not increase the risk of cerebral hemorrhage. This finding calls for systemic analysis of the effects of thrombolytic stroke therapy, first in humanized sickle mice, and then in patients. There is also a need for additional predictive markers of sickle cell anemia-associated vasculopathy. We used Doppler ultrasound to examine the carotid artery of Townes sickle mice tested their responses to repetitive mild hypoxia-ischemia- and transient hypoxia-ischemia-induced stroke at 3 or 6 months of age, respectively. We also examined the effects of tPA (tissue-type plasminogen activator) treatment in transient hypoxia-ischemia-injured sickle mice. Three-month-old sickle cell (SS) mice showed elevated resistive index in the carotid artery and higher sensitivity to repetitive mild hypoxia-ischemia-induced cerebral infarct. Six-month-old SS mice showed greater resistive index and increased flow velocity without obstructive vasculopathy in the carotid artery. Instead, the cerebral vascular wall in SS mice showed ectopic expression of PAI-1 (plasminogen activator inhibitor-1) and P-selectin, suggesting a proadhesive and prothrombotic propensity. Indeed, SS mice showed enhanced leukocyte and platelet adherence to the cerebral vascular wall, broader fibrin deposition, and higher mortality after transient hypoxia-ischemia. Yet, post-transient hypoxia-ischemia treatment with tPA reduced thrombosis and mortality in SS mice. Sickle mice are sensitive to hypoxia/ischemia-induced cerebral infarct but benefit from thrombolytic treatment. An increased resistive index in carotid arteries may be an early marker of sickle cell vasculopathy. © 2017 American Heart Association, Inc.

Expression of the p53 target CDIP correlates with sensitivity to TNFα-induced apoptosis in cancer cells.

PubMed

Brown-Endres, Lauren; Schoenfeld, David; Tian, Fang; Kim, Hyung-Gu; Namba, Takushi; Muñoz-Fontela, César; Mandinova, Anna; Aaronson, Stuart A; Lee, Sam W

2012-05-01

TNFα is a pleiotropic cytokine that signals for both survival and apoptotic cell fates. It is still unclear that the dual role of TNFα can be regulated in cancer cells. We previously described an apoptotic pathway involving p53→CDIP→TNFα that was activated in response to genotoxic stress. This pathway operated in the presence of JNK activation; therefore, we postulated that CDIP itself could sensitize cells to a TNFα apoptotic cell fate, survival, or death. We show that CDIP mediates sensitivity to TNFα-induced apoptosis and that cancer cells with endogenous CDIP expression are inherently sensitive to the growth-suppressive effects of TNFα in vitro and in vivo. Thus, CDIP expression correlates with sensitivity of cancer cells with TNFα, and CDIP seems to be a regulator of the p53-mediated death versus survival response of cells to TNFα. This CDIP-mediated sensitivity to TNFα-induced apoptosis favors pro- over antiapoptotic program in cancer cells, and CDIP may serve as a predictive biomarker for such sensitivity. ©2012 AACR

Expression of the p53 target CDIP correlates with sensitivity to TNF-alpha induced apoptosis in cancer cells

PubMed Central

Brown-Endres, Lauren; Schoenfeld, David; Tian, Fang; Kim, Hyung-Gu; Namba, Takushi; Muñoz-Fontela, César; Mandinova, Anna; Aaronson, Stuart A.; Lee, Sam W.

2012-01-01

TNFα is a pleiotropic cytokine that signals for both survival and apoptotic cell fates. It is still unclear that the dual role of TNFα can be regulated in cancer cells. We previously described an apoptotic pathway involving p53→CDIP→TNFα that was activated in response to genotoxic stress. This pathway operated in the presence of JNK activation; therefore, we postulated that CDIP itself could sensitize cells to a TNFα apoptotic cell fate, survival or death. We show that CDIP mediates sensitivity to TNFα-induced apoptosis, and that cancer cells with endogenous CDIP expression are inherently sensitive to the growth suppressive effects of TNFα in vitro and in vivo. Thus, CDIP expression correlates with sensitivity of cancer cells with TNFα, and CDIP appears to be a regulator of the p53-mediated death versus survival response of cells to TNFα. This CDIP-mediated sensitivity to TNFα-induced apoptosis favors pro-over anti-apoptotic program in cancer cells and CDIP may serve as a predictive biomarker for such sensitivity. PMID:22549949

Chronic Opioid Therapy and Central Sensitization in Sickle Cell Disease

PubMed Central

Carroll, C. Patrick; Lanzkron, Sophie; Haywood, Carlton; Kiley, Kasey; Pejsa, Megan; Moscou-Jackson, Gyasi; Haythornthwaite, Jennifer A.; Campbell, Claudia M.

2016-01-01

Chronic opioid therapy (COT) for chronic non-cancer pain is frequently debated, and its effectiveness is unproven in sickle cell disease (SCD). The authors conducted a descriptive study among 83 adult SCD patients and compared severity of disease and pain symptoms among those who were prescribed COT (n=29) with those who were not using COT. All patients completed baseline laboratory pain assessment and questionnaires between January 2010 and June 2014. Thereafter, participants recorded daily pain, crises, function, and healthcare utilization for 90 days using electronic diaries. Analyses were conducted shortly after the final diary data collection period. Patients on COT did not differ on age, sex, or measures of disease severity. However, patients on COT exhibited greater levels of clinical pain (particularly non-crisis), central sensitization, depression, and increased diary measures of pain severity, function, and healthcare utilization on crisis and non-crisis diary days, as well as a greater proportion of days in crisis. Including depressive symptoms in multivariate models did not change the associations between COT and pain, interference, central sensitization, or utilization. Additionally, participants not on COT displayed the expected positive relationship between central sensitization and clinical pain, whereas those on COT demonstrated no such relationship, despite having both higher central sensitization and higher clinical pain. Overall, the results point out a high symptom burden in SCD patients on COT, including those on high-dose COT, and suggest that nociceptive processing in SCD patients on COT differs from those who are not. PMID:27320469

Aging properties of Kodak type 101 emulsions

NASA Technical Reports Server (NTRS)

Dohne, B.; Feldman, U.; Neupert, W.

1984-01-01

Aging tests for several batches of Kodak type 101 emulsion show that storage conditions significantly influence how well the film will maintain its sensitometric properties, with sensitivity and density increasing to a maximum during this period. Any further aging may result in higher fog levels and sensitivity loss. It is noted that storage in an environment free of photographically active compounds allows film property optimization, and that film batches with different sensitivities age differently. Emulsions with maximum 1700-A sensitivity are 2.5 times faster than those at the low end of the sensitivity scale. These sensitive emulsions exhibit significantly accelerated changes in aging properties. Their use in space applications requires careful consideration of time and temperature profiles, encouraging the use of less sensitive emulsions when the controllability of these factors is limited.

Increased Na+/H+ exchanger activity on the apical surface of a cilium-deficient cortical collecting duct principal cell model of polycystic kidney disease

PubMed Central

Olteanu, Dragos; Liu, Xiaofen; Liu, Wen; Roper, Venus C.; Sharma, Neeraj; Yoder, Bradley K.; Satlin, Lisa M.; Schwiebert, Erik M.

2012-01-01

Pathophysiological anomalies in autosomal dominant and recessive forms of polycystic kidney disease (PKD) may derive from impaired function/formation of the apical central monocilium of ductal epithelia such as that seen in the Oak Ridge polycystic kidney or orpk (Ift88Tg737Rpw) mouse and its immortalized cell models for the renal collecting duct. According to a previous study, Na/H exchanger (NHE) activity may contribute to hyperabsorptive Na+ movement in cilium-deficient (“mutant”) cortical collecting duct principal cell monolayers derived from the orpk mice compared with cilium-competent (“rescued”) monolayers. To examine NHE activity, we measured intracellular pH (pHi) by fluorescence imaging with the pH-sensitive dye BCECF, and used a custom-designed perfusion chamber to control the apical and basolateral solutions independently. Both mutant and rescued monolayers exhibited basolateral Na+-dependent acid-base transporter activity in the nominal absence of CO2/HCO3−. However, only the mutant cells displayed appreciable apical Na+-induced pHi recoveries from NH4+ prepulse-induced acid loads. Similar results were obtained with isolated, perfused collecting ducts from orpk vs. wild-type mice. The pHi dependence of basolateral cariporide/HOE-694-sensitive NHE activity under our experimental conditions was similar in both mutant and rescued cells, and 3.5- to 4.5-fold greater than apical HOE-sensitive NHE activity in the mutant cells (pHi 6.23–6.68). Increased apical NHE activity correlated with increased apical NHE1 expression in the mutant cells, and increased apical localization in collecting ducts of kidney sections from orpk vs. control mice. A kidney-specific conditional cilium-knockout mouse produced a more acidic urine compared with wild-type littermates and became alkalotic by 28 days of age. This study provides the first description of altered NHE activity, and an associated acid-base anomaly in any form of PKD. PMID:22301060

[Knockdown of ATG5 enhances the sensitivity of human renal carcinoma cells to sunitinib].

PubMed

Li, Peng; Han, Qi; Tang, Ming; Zhang, Keqin

2017-03-01

Objective To investigate the expression levels of autophagy-related gene 5 (ATG5) and microtubule-associated protein 1 light chain 3 (LC3) and their effects on sunitinib resistance in human renal carcinoma cells. Methods After clinic-pathologic feature and survival analysis, 99 renal clear cell carcinoma tissues with different histological grades were used to detect the expression of ATG5 and LC3 by immunohistochemistry. Renal carcinoma cell line A-498 was infected with lentivirus-mediated ATG5 shRNA. Western blot analysis was performed to confirm the efficiency of ATG5 knockdown. Proliferation rate of A-498 cells in control group and ATG5 low expression group was determined by flow cytometry. Finally, the survival rate was detected by MTT assay after A-498 cells were treated with different concentrations of sunitinib. Results The expression levels of ATG5 and LC3 in renal clear cell carcinoma tissues were significantly higher than those in para-tumor tissues. The expression levels of ATG5 and LC3 were associated with classification, histological grade, TNM stage and survival rate, rather than gender, age, location, tumor size. Compared with the control group, the protein expressions of ATG5 and LC3 significantly decreased in A-498 cells with ATG5 low expression. The cell proliferation rate in ATG5 downregulation group was lower than that in the control group. Compared with control group, the survival rate in ATG5 low expression group were significantly reduced in a dose-dependent manner after sunitinib treatment. Conclusion Autophagy is active in renal clear cell carcinoma, and the drug sensitivity to sunitinib in renal cancer cells can be enhanced by the downregulation of ATG5.

Aldolase B knockdown prevents high glucose-induced methylglyoxal overproduction and cellular dysfunction in endothelial cells.

PubMed

Liu, Jianghai; Mak, Timothy Chun-Ping; Banigesh, Ali; Desai, Kaushik; Wang, Rui; Wu, Lingyun

2012-01-01

We used cultured endothelial cells as a model to examine whether up-regulation of aldolase B and enhanced methylglyoxal (MG) formation play an important role in high glucose-induced overproduction of advanced glycosylation endproducts (AGEs), oxidative stress and cellular dysfunction. High glucose (25 mM) incubation up-regulated mRNA levels of aldose reductase (an enzyme converting glucose to fructose) and aldolase B (a key enzyme that catalyzes MG formation from fructose) and enhanced MG formation in human umbilical vein endothelial cells (HUVECs) and HUVEC-derived EA. hy926 cells. High glucose-increased MG production in EA. hy926 cells was completely prevented by siRNA knockdown of aldolase B, but unaffected by siRNA knockdown of aldolase A, an enzyme responsible for MG formation during glycolysis. In addition, inhibition of cytochrome P450 2E1 or semicarbazide-sensitive amine oxidase which produces MG during the metabolism of lipid and proteins, respectively, did not alter MG production. Both high glucose (25 mM) and MG (30, 100 µM) increased the formation of N(ε)-carboxyethyl-lysine (CEL, a MG-induced AGE), oxidative stress (determined by the generation of oxidized DCF, H(2)O(2), protein carbonyls and 8-oxo-dG), O-GlcNAc modification (product of the hexosamine pathway), membrane protein kinase C activity and nuclear translocation of NF-κB in EA. hy926 cells. However, the above metabolic and signaling alterations induced by high glucose were completely prevented by knockdown of aldolase B and partially by application of aminoguanidine (a MG scavenger) or alagebrium (an AGEs breaker). In conclusion, efficient inhibition of aldolase B can prevent high glucose-induced overproduction of MG and related cellular dysfunction in endothelial cells.

Deficiency of CB2 cannabinoid receptor in mice improves insulin sensitivity but increases food intake and obesity with age.

PubMed

Agudo, J; Martin, M; Roca, C; Molas, M; Bura, A S; Zimmer, A; Bosch, F; Maldonado, R

2010-12-01

The endocannabinoid system has a key role in energy storage and metabolic disorders. The endocannabinoid receptor 2 (CB2R), which was first detected in immune cells, is present in the main peripheral organs responsible for metabolic control. During obesity, CB2R is involved in the development of adipose tissue inflammation and fatty liver. We examined the long-term effects of CB2R deficiency in glucose metabolism. Mice deficient in CB2R (Cb2 ( -/- ) [also known as Cnr2]) were studied at different ages (2-12 months). Two-month-old Cb2 (-/-) and wild-type mice were treated with a selective CB2R antagonist or fed a high-fat diet. The lack of CB2R in Cb2 (-/-) mice led to greater increases in food intake and body weight with age than in Cb2 (+/+) mice. However, 12-month-old obese Cb2 (-/-) mice did not develop insulin resistance and showed enhanced insulin-stimulated glucose uptake in skeletal muscle. In agreement, adipose tissue hypertrophy was not associated with inflammation. Similarly, treatment of wild-type mice with CB2R antagonist resulted in improved insulin sensitivity. Moreover, when 2-month-old Cb2 (-/-) mice were fed a high-fat diet, reduced body weight gain and normal insulin sensitivity were observed. These results indicate that the lack of CB2R-mediated responses protected mice from both age-related and diet-induced insulin resistance, suggesting that these receptors may be a potential therapeutic target in obesity and insulin resistance.

Redox signaling in skeletal muscle: role of aging and exercise.

PubMed

Ji, Li Li

2015-12-01

Skeletal muscle contraction is associated with the production of ROS due to altered O2 distribution and flux in the cell. Despite a highly efficient antioxidant defense, a small surplus of ROS, such as hydrogen peroxide and nitric oxide, may serve as signaling molecules to stimulate cellular adaptation to reach new homeostasis largely due to the activation of redox-sensitive signaling pathways. Recent research has highlighted the important role of NF-κB, MAPK, and peroxisome proliferator-activated receptor-γ coactivator-1α, along with other newly discovered signaling pathways, in some of the most vital biological functions, such as mitochondrial biogenesis, antioxidant defense, inflammation, protein turnover, apoptosis, and autophagy. There is evidence that the inability of the cell to maintain proper redox signaling underlies some basic mechanisms of biological aging, during which inflammatory and catabolic pathways eventually predominate. Physical exercise has been shown to activate various redox signaling pathways that control the adaptation and remodeling process. Although this stimulatory effect of exercise declines with aging, it is not completed abolished. Thus, aged people can still benefit from regular physical activity in the appropriate forms and at proper intensity to preserve muscle function. Copyright © 2015 The American Physiological Society.

Consuming a Diet Supplemented with Resveratrol Reduced Infection-Related Neuroinflammation and Deficits in Working Memory in Aged Mice

PubMed Central

Abraham, Jayne

2009-01-01

Abstract Aged mice treated peripherally with lipopolysaccharide (LPS) show an exaggerated neuroinflammatory response and cognitive deficits compared to adults. Considerable evidence suggests resveratrol, a polyphenol found in red grapes, has potent antiinflammatory effects in the periphery, but its effects on the central inflammatory response and cognitive behavior are unknown. Therefore, the current study investigated if resveratrol dietary supplementation would inhibit neuroinflammation as well as behavioral and cognitive deficits in aged mice given LPS to mimic a peripheral infection. In initial studies, adult (3–6 months) and aged (22–24 months) mice were provided control or resveratrol-supplemented diet for 4 weeks and then injected intraperitoneally (i.p.) with saline or LPS, and locomotor activity and spatial working memory were assessed. As anticipated, deficits in locomotor activity and spatial working memory indicated aged mice are more sensitive to LPS compared to adults. More importantly, the LPS-induced deficits in aged animals were mitigated by dietary supplementation of resveratrol. In addition, resveratrol consumption reduced LPS-induced interleukin-1β (IL-1β) in plasma and the IL-1β mRNA in the hippocampus of aged mice. Finally, pretreatment of BV-2 microglial cells with resveratrol potently inhibited LPS-induced IL-1β production. These data show that aged mice are more sensitive than adult mice to both the inflammatory and cognitive effects of peripheral immune stimulation and suggest that resveratrol may be useful for attenuating acute cognitive disorders in elderly individuals with an infection. PMID:20041738

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

Hu, Zhi; Huang, Ge; Sadanandam, Anguraj

Introduction: HJURP (Holliday Junction Recognition Protein) is a newly discovered gene reported to function at centromeres and to interact with CENPA. However its role in tumor development remains largely unknown. The goal of this study was to investigate the clinical significance of HJURP in breast cancer and its correlation with radiotherapeutic outcome. Methods: We measured HJURP expression level in human breast cancer cell lines and primary breast cancers by Western blot and/or by Affymetrix Microarray; and determined its associations with clinical variables using standard statistical methods. Validation was performed with the use of published microarray data. We assessed cell growthmore » and apoptosis of breast cancer cells after radiation using high-content image analysis. Results: HJURP was expressed at higher level in breast cancer than in normal breast tissue. HJURP mRNA levels were significantly associated with estrogen receptor (ER), progesterone receptor (PR), Scarff-Bloom-Richardson (SBR) grade, age and Ki67 proliferation indices, but not with pathologic stage, ERBB2, tumor size, or lymph node status. Higher HJURP mRNA levels significantly decreased disease-free and overall survival. HJURP mRNA levels predicted the prognosis better than Ki67 proliferation indices. In a multivariate Cox proportional-hazard regression, including clinical variables as covariates, HJURP mRNA levels remained an independent prognostic factor for disease-free and overall survival. In addition HJURP mRNA levels were an independent prognostic factor over molecular subtypes (normal like, luminal, Erbb2 and basal). Poor clinical outcomes among patients with high HJURP expression werevalidated in five additional breast cancer cohorts. Furthermore, the patients with high HJURP levels were much more sensitive to radiotherapy. In vitro studies in breast cancer cell lines showed that cells with high HJURP levels were more sensitive to radiation treatment and had a higher rate of apoptosis than those with low levels. Knock down of HJURP in human breast cancer cells using shRNA reduced the sensitivity to radiation treatment. HJURP mRNA levels were significantly correlated with CENPA mRNA levels. Conclusions: HJURP mRNA level is a prognostic factor for disease-free and overall survival in patients with breast cancer and is a predictive biomarker for sensitivity to radiotherapy.« less

Isolation of uv-sensitive variants of human FL cells by a viral suicide method

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

Shiomi, T.; Sato, K.

A new method (viral suicide method) for the isolation of uv-sensitive mutants is described. Colonies of mutagenized human FL cells were infected with uv-irradiated Herpes simplex viruses and surviving ones which seemed to be deficient in host cell reactivation (HCR) were examined for their uv sensitivity. Nineteen of 238 clones examined were sensitive to uv irradiation at the time of the isolation. After recloning, four of these clones have been studied and two (UVS-1 and UVS-2) of them are stable in their uv sensitivity for 4 months in culture. uv sensitivity of UVS-1, UVS-2, and the parental FL cells aremore » as follows: the extrapolation numbers (n) are 2.2, 2.1, and 1.8 and mean lethal doses (DO) are 2.9, 3.7, and 7.8 J/m/sup 2/ for UVS-1, UVS-2, and the parental FL cells, respectively. They are no more sensitive than FL cells to x-irradiation. The ability of HCR in UVS-2 cells is apparently lower than that in FL cells, whereas UVS-1 cells are the same as FL cells in the ability.« less

Mouse Tmem135 mutation reveals a mechanism involving mitochondrial dynamics that leads to age-dependent retinal pathologies

PubMed Central

Lee, Wei-Hua; Higuchi, Hitoshi; Ikeda, Sakae; Macke, Erica L; Takimoto, Tetsuya; Pattnaik, Bikash R; Liu, Che; Chu, Li-Fang; Siepka, Sandra M; Krentz, Kathleen J; Rubinstein, C Dustin; Kalejta, Robert F; Thomson, James A; Mullins, Robert F; Takahashi, Joseph S; Pinto, Lawrence H; Ikeda, Akihiro

2016-01-01

While the aging process is central to the pathogenesis of age-dependent diseases, it is poorly understood at the molecular level. We identified a mouse mutant with accelerated aging in the retina as well as pathologies observed in age-dependent retinal diseases, suggesting that the responsible gene regulates retinal aging, and its impairment results in age-dependent disease. We determined that a mutation in the transmembrane 135 (Tmem135) is responsible for these phenotypes. We observed localization of TMEM135 on mitochondria, and imbalance of mitochondrial fission and fusion in mutant Tmem135 as well as Tmem135 overexpressing cells, indicating that TMEM135 is involved in the regulation of mitochondrial dynamics. Additionally, mutant retina showed higher sensitivity to oxidative stress. These results suggest that the regulation of mitochondrial dynamics through TMEM135 is critical for protection from environmental stress and controlling the progression of retinal aging. Our study identified TMEM135 as a critical link between aging and age-dependent diseases. DOI: http://dx.doi.org/10.7554/eLife.19264.001 PMID:27863209

Results at recruitment from a randomized controlled trial comparing human papillomavirus testing alone with conventional cytology as the primary cervical cancer screening test.

PubMed

Ronco, Guglielmo; Giorgi-Rossi, Paolo; Carozzi, Francesca; Confortini, Massimo; Dalla Palma, Paolo; Del Mistro, Annarosa; Gillio-Tos, Anna; Minucci, Daria; Naldoni, Carlo; Rizzolo, Raffaella; Schincaglia, Patrizia; Volante, Renza; Zappa, Marco; Zorzi, Manuel; Cuzick, Jack; Segnan, Nereo

2008-04-02

In the first recruitment phase of a randomized trial of cervical cancer screening methods (New Technologies for Cervical Cancer Screening [NTCC] study), we compared screening with conventional cytology with screening by human papillomavirus (HPV) testing in combination with liquid-based cytology. HPV-positive women were directly referred to colposcopy if aged 35 or older; if younger, they were retested after 1 year. In the second recruitment phase of NTCC, we randomly assigned women to conventional cytology (n = 24,661) with referral to colposcopy if cytology indicated atypical squamous cells of undetermined significance or more severe abnormality or to testing for high-risk HPV DNA alone by Hybrid Capture 2 (n = 24,535) with referral to colposcopy if the test was positive at a concentration of HPV DNA 1 pg/mL or greater. For the main endpoint of the study, histologic detection of cervical intraepithelial neoplasia of grade 2 or more (CIN2+), we calculated and compared sensitivity and positive predictive value (PPV) of the two screening methods using HPV DNA cutoffs of 1 pg/mL and 2 pg/mL. All statistical tests were two-sided. For women aged 35-60 years, the relative sensitivity of HPV testing for detection of CIN2+ at a cutoff of 1 pg/mL vs conventional cytology was 1.92 (95% CI = 1.28 to 2.87) and the relative PPV was 0.80 (95% CI = 0.55 to 1.18). At a cutoff of 2 pg/mL HPV DNA, the relative sensitivity was 1.81 (95% CI = 1.20 to 2.72) and the relative PPV was 0.99 (95% CI = 0.67 to 1.46). In this age group, there was no evidence of heterogeneity between study phases. Among women aged 25-34 years, the relative sensitivity for detection of CIN2+ of HPV testing at a cutoff of 1 pg/mL vs cytology was 3.50 (95% CI = 2.11 to 5.82), statistically significantly larger (P = .019) than that observed in phase 1 at this age (1.58; 95% CI = 1.03 to 2.44). For women aged 35-60 years, HPV testing with a cutoff of 2 pg/mL achieves a substantial gain in sensitivity over cytology with only a small reduction in PPV. Among women aged 25-34 years, the large relative sensitivity of HPV testing compared with conventional cytology and the difference between relative sensitivity during phases 1 and 2 suggests that there is frequent regression of CIN2+ that are detected by direct referral of younger HPV-positive women to colposcopy. Thus, triage test or repeat testing is needed if HPV is to be used for primary testing in this context.

Dysregulation of glucose metabolism even in Chinese PCOS women with normal glucose tolerance.

PubMed

Li, Weiping; Li, Qifu

2012-01-01

To clarify the necessity of improving glucose metabolism in polycystic ovary syndrome (PCOS) women as early as possible, 111 PCOS women with normal glucose tolerance and 92 healthy age-matched controls were recruited to investigate glucose levels distribution, insulin sensitivity and β cell function. 91 PCOS women and 33 controls underwent hyperinsulinemic-euglycemic clamp to assess their insulin sensitivity, which was expressed as M value. β cell function was estimated by homeostatic model assessment (HOMA)-β index after adjusting insulin sensitivity (HOMA-βad index). Compared with lean controls, lean PCOS women had similar fasting plasma glucose (FPG), higher postprandial plasma glucose (PPG) (6.03±1.05 vs. 5.44±0.97 mmol/L, P<0.05), lower M value but similar HOMA-βad index, while overweight/obese PCOS women had higher levels of both FPG (5.24±0.58 vs. 4.90±0.39, P<0.05) and PPG (6.15±0.84 vs. 5.44±0.97 mmol/L, P<0.05), and lower levels of both M value and HOMA-βad index. Linear regression and ROC analysis found BMI was independently associated with M value and HOMA-βad index in PCOS women separately, and the cutoff of BMI indicating impaired β cell function of PCOS women was 25.545kg/m². In conclusion, insulin resistance and dysregulation of glucose metabolism were common in Chinese PCOS women with normal glucose tolerance. BMI ≥ 25.545kg/m² indicated impaired β cell function in PCOS women with normal glucose tolerance.

Adipocyte Triglyceride Turnover Is Independently Associated With Atherogenic Dyslipidemia

PubMed Central

Frayn, Keith; Bernard, Samuel; Spalding, Kirsty; Arner, Peter

2012-01-01

Background Inappropriate storage of fatty acids as triglycerides in adipocytes and their removal from adipocytes through lipolysis and subsequent oxidation may cause the atherogenic dyslipidemia phenotype of elevated apolipoprotein B levels and subsequent hypertriglyceridemia. We tested whether turnover of triglycerides in fat cells was related to dyslipidemia. Methods and Results The age of triglycerides (reflecting removal) and triglyceride storage in adipocytes was determined under free living conditions by measuring incorporation of atmospheric 14C into these lipids within the adipocytes in 47 women and 26 men with a large interindividual variability in body mass index. Because limited 14C data were available, triglyceride age was also determined in 97 men and 233 women by using an algorithm based on adipocyte lipolysis, body fat content, waist‐to‐hip ratio, and insulin sensitivity. This cohort consisted of nonobese subjects since obesity per se is related to all components in the algorithm. Triglyceride turnover (age and storage) was compared with plasma levels of apolipoproteins and lipids. Plasma levels of apolipoprotein B and triglycerides were positively related to triglyceride age in adipocytes, when measured directly using radiocarbon analyses (r=0.45 to 0.47; P<0.0001). This effect was independent of subject age, waist circumference measures, and insulin sensitivity (partial r=0.29 to 0.45; P from 0.03 to <0.0001). Triglyceride storage showed no independent correlation (partial r=0.02 to 0.11; P=0.42 to 0.91). Algorithm‐based values for adipocyte removal of triglycerides were positively associated with plasma triglycerides and apolipoprotein B (r=0.44 to 0.45; P<0.0001) and (also positively) with the inflammation status of adipose tissue (r=0.39 to 0.47; P<0.05). These correlations were statistically independent of subject age and observed in men and women as well as in lean and overweight subjects when subgroups were examined separately. Conclusions Decreased removal of adipocyte triglycerides (as indicated by a high triglyceride age in fat cells) is independently associated with circulating apolipoprotein B and triglycerides. This suggests a hitherto unknown role of triglyceride turnover in adipocytes for the development and/or maintenance of atherogenic dyslipidemia. PMID:23316323

KRAS Mutation Is a Predictor of Oxaliplatin Sensitivity in Colon Cancer Cells

PubMed Central

Lin, Yu-Lin; Ou, Da-Liang; Lin, Liang-In; Tseng, Li-Hui; Chang, Yih-Leong; Yeh, Kun-Huei; Cheng, Ann-Lii

2012-01-01

Molecular biomarkers to determine the effectiveness of targeted therapies in cancer treatment have been widely adopted in colorectal cancer (CRC), but those to predict chemotherapy sensitivity remain poorly defined. We tested our hypothesis that KRAS mutation may be a predictor of oxaliplatin sensitivity in CRC. KRAS was knocked-down in KRAS-mutant CRC cells (DLD-1G13D and SW480G12V) by small interfering RNAs (siRNA) and overexpressed in KRAS-wild-type CRC cells (COLO320DM) by KRAS-mutant vectors to generate paired CRC cells. These paired CRC cells were tested by oxaliplatin, irinotecan and 5FU to determine the change in drug sensitivity by MTT assay and flow cytometry. Reasons for sensitivity alteration were further determined by western blot and real-time quantitative reverse transcriptase polymerase chain reaction (qRT -PCR). In KRAS-wild-type CRC cells (COLO320DM), KRAS overexpression by mutant vectors caused excision repair cross-complementation group 1 (ERCC1) downregulation in protein and mRNA levels, and enhanced oxaliplatin sensitivity. In contrast, in KRAS-mutant CRC cells (DLD-1G13D and SW480G12V), KRAS knocked-down by KRAS-siRNA led to ERCC1 upregulation and increased oxaliplatin resistance. The sensitivity of irinotecan and 5FU had not changed in the paired CRC cells. To validate ERCC1 as a predictor of sensitivity for oxaliplatin, ERCC1 was knocked-down by siRNA in KRAS-wild-type CRC cells, which restored oxaliplatin sensitivity. In contrast, ERCC1 was overexpressed by ERCC1-expressing vectors in KRAS-mutant CRC cells, and caused oxaliplatin resistance. Overall, our findings suggest that KRAS mutation is a predictor of oxaliplatin sensitivity in colon cancer cells by the mechanism of ERCC1 downregulation. PMID:23209813

Kex1 protease is involved in yeast cell death induced by defective N-glycosylation, acetic acid, and chronological aging.

PubMed

Hauptmann, Peter; Lehle, Ludwig

2008-07-04

N-glycosylation in the endoplasmic reticulum is an essential protein modification and highly conserved in evolution from yeast to humans. The key step of this pathway is the transfer of the lipid-linked core oligosaccharide to the nascent polypeptide chain, catalyzed by the oligosaccharyltransferase complex. Temperature-sensitive oligosaccharyltransferase mutants of Saccharomyces cerevisiae at the restrictive temperature, such as wbp1-1, as well as wild-type cells in the presence of the N-glycosylation inhibitor tunicamycin display typical apoptotic phenotypes like nuclear condensation, DNA fragmentation, phosphatidylserine translocation, caspase-like activity, and reactive oxygen species accumulation. Since deletion of the yeast metacaspase YCA1 did not abrogate this death pathway, we postulated a different proteolytic process to be responsible. Here, we show that Kex1 protease is involved in the programmed cell death caused by defective N-glycosylation. Its disruption decreases caspase-like activity, production of reactive oxygen species, and fragmentation of mitochondria and, conversely, improves growth and survival of cells. Moreover, we demonstrate that Kex1 contributes also to the active cell death program induced by acetic acid stress or during chronological aging, suggesting that Kex1 plays a more general role in cellular suicide of yeast.

CIP2A down regulation enhances the sensitivity of pancreatic cancer cells to gemcitabine.

PubMed

Xu, Peng; Yao, Jie; He, Jin; Zhao, Long; Wang, Xiaodong; Li, Zhennan; Qian, Jianjun

2016-03-22

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein which participates in inhibiting tumor apoptosis in pancreatic cancer cells. Using immunohistochemical staining, we investigated the expression of CIP2A protein in 72 cases of human pancreatic ductal adenocarcinoma (PDAC) tissue and 27 cases of adjacent normal pancreatic tissue. The positive rate of CIP2A protein expression in pancreatic cancer tissue was70.83 %, which was significantly higher than that in adjacent non- cancerous pancreatic tissue (11.11%). The expression of CIP2A was found to be correlated with TNM stage, but not correlated with age, gender, tumor location, smoking status, alcohol consumption, diabetes, high blood pressure, BMI, tumor size, lymph node metastasis or distant metastases. Kaplan- Meier survival analysis showed that patients with positive CIP2A protein expression had a lower overall survival rate than patients without CIP2A expression. COX regression analysis indicated that expression of CIP2A was an independent prognostic factor for pancreatic ductal adenocarcinoma. In addition, down-regulation of CIP2A inhibited cell proliferation and increased sensitivity to gemcitabine in pancreatic cancer cells by decreasing AKT signaling pathway. Our results indicated that down-regulation of CIP2A could be a novel therapeutic strategy for pancreatic cancer.

MYCN amplification confers enhanced folate dependence and methotrexate sensitivity in neuroblastoma

PubMed Central

Lau, Diana T.; Flemming, Claudia L.; Gherardi, Samuele; Perini, Giovanni; Oberthuer, André; Fischer, Matthias; Juraeva, Dilafruz; Brors, Benedikt; Xue, Chengyuan; Norris, Murray D.; Marshall, Glenn M.; Haber, Michelle

2015-01-01

MYCN amplification occurs in 20% of neuroblastomas and is strongly related to poor clinical outcome. We have identified folate-mediated one-carbon metabolism as highly upregulated in neuroblastoma tumors with MYCN amplification and have validated this finding experimentally by showing that MYCN amplified neuroblastoma cell lines have a higher requirement for folate and are significantly more sensitive to the antifolate methotrexate than cell lines without MYCN amplification. We have demonstrated that methotrexate uptake in neuroblastoma cells is mediated principally by the reduced folate carrier (RFC; SLC19A1), that SLC19A1 and MYCN expression are highly correlated in both patient tumors and cell lines, and that SLC19A1 is a direct transcriptional target of N-Myc. Finally, we assessed the relationship between SLC19A1 expression and patient survival in two independent primary tumor cohorts and found that SLC19A1 expression was associated with increased risk of relapse or death, and that SLC19A1 expression retained prognostic significance independent of age, disease stage and MYCN amplification. This study adds upregulation of folate-mediated one-carbon metabolism to the known consequences of MYCN amplification, and suggests that this pathway might be targeted in poor outcome tumors with MYCN amplification and high SLC19A1 expression. PMID:25860940

A systematic study on drug-response associated genes using baseline gene expressions of the Cancer Cell Line Encyclopedia

NASA Astrophysics Data System (ADS)

Liu, Xiaoming; Yang, Jiasheng; Zhang, Yi; Fang, Yun; Wang, Fayou; Wang, Jun; Zheng, Xiaoqi; Yang, Jialiang

2016-03-01

We have studied drug-response associated (DRA) gene expressions by applying a systems biology framework to the Cancer Cell Line Encyclopedia data. More than 4,000 genes are inferred to be DRA for at least one drug, while the number of DRA genes for each drug varies dramatically from almost 0 to 1,226. Functional enrichment analysis shows that the DRA genes are significantly enriched in genes associated with cell cycle and plasma membrane. Moreover, there might be two patterns of DRA genes between genders. There are significantly shared DRA genes between male and female for most drugs, while very little DRA genes tend to be shared between the two genders for a few drugs targeting sex-specific cancers (e.g., PD-0332991 for breast cancer and ovarian cancer). Our analyses also show substantial difference for DRA genes between young and old samples, suggesting the necessity of considering the age effects for personalized medicine in cancers. Lastly, differential module and key driver analyses confirm cell cycle related modules as top differential ones for drug sensitivity. The analyses also reveal the role of TSPO, TP53, and many other immune or cell cycle related genes as important key drivers for DRA network modules. These key drivers provide new drug targets to improve the sensitivity of cancer therapy.

Mitochondrial DNA common deletion in the human eye: a relation with corneal aging.

PubMed

Gendron, Sébastien P; Mallet, Justin D; Bastien, Nathalie; Rochette, Patrick J

2012-01-01

The most frequent mitochondrial DNA (mtDNA) mutation is a 4977 bp deletion known as the common deletion (mtDNA(CD4977)). mtDNA(CD4977) is related to skin photo-aging and to chronological aging of cells with high-energy demands such as neurons and muscle cells. The human eye contains both sun-exposed (cornea, iris) and high-energy demand structures (retina). In this study, we employed a highly sensitive quantitative PCR technique to determine mtDNA(CD4977) occurrence in different structures of the human eye. We found that the cornea, the most anterior structure of the eye, contains the highest amount of mtDNA(CD4977) (2.6%, 0.25% and 0.06% for the cornea, iris and retina, respectively). Within the cornea, mtDNA(CD4977) is almost exclusively found in the stroma, the cellular layer conferring transparency and rigidity to the human cornea (8.59%, 0.13% and 0.05% in the stroma, endothelium and epithelium, respectively). Moreover, we show that mtDNA(CD4977) accumulates with age in the corneal stroma. Taken together, our results suggest that mtDNA(CD4977) is related to photo-aging rather than chronological aging in the human eye. Similar to the involvement of mtDNA(CD4977) in skin photo-aging phenotypes, we believe that the clinical manifestations of corneal aging, including clouding and stiffening, are associated with the accumulation of mtDNA(CD4977) in the corneal stroma. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA.

PubMed

Gao, Qiuqiang; Liou, Liang-Chun; Ren, Qun; Bao, Xiaoming; Zhang, Zhaojie

2014-03-03

The yeast cell wall plays an important role in maintaining cell morphology, cell integrity and response to environmental stresses. Here, we report that salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA (ρ 0 ). Upon salt treatment, the cell wall is thickened, broken and becomes more sensitive to the cell wall-perturbing agent sodium dodecyl sulfate (SDS). Also, SCW11 mRNA levels are elevated in ρ 0 cells. Deletion of SCW11 significantly decreases the sensitivity of ρ 0 cells to SDS after salt treatment, while overexpression of SCW11 results in higher sensitivity. In addition, salt stress in ρ 0 cells induces high levels of reactive oxygen species (ROS), which further damages the cell wall, causing cells to become more sensitive towards the cell wall-perturbing agent.

Alternative rapamycin treatment regimens mitigate the impact of rapamycin on glucose homeostasis and the immune system.

PubMed

Arriola Apelo, Sebastian I; Neuman, Joshua C; Baar, Emma L; Syed, Faizan A; Cummings, Nicole E; Brar, Harpreet K; Pumper, Cassidy P; Kimple, Michelle E; Lamming, Dudley W

2016-02-01

Inhibition of the mechanistic target of rapamycin (mTOR) signaling pathway by the FDA-approved drug rapamycin has been shown to promote lifespan and delay age-related diseases in model organisms including mice. Unfortunately, rapamycin has potentially serious side effects in humans, including glucose intolerance and immunosuppression, which may preclude the long-term prophylactic use of rapamycin as a therapy for age-related diseases. While the beneficial effects of rapamycin are largely mediated by the inhibition of mTOR complex 1 (mTORC1), which is acutely sensitive to rapamycin, many of the negative side effects are mediated by the inhibition of a second mTOR-containing complex, mTORC2, which is much less sensitive to rapamycin. We hypothesized that different rapamycin dosing schedules or the use of FDA-approved rapamycin analogs with different pharmacokinetics might expand the therapeutic window of rapamycin by more specifically targeting mTORC1. Here, we identified an intermittent rapamycin dosing schedule with minimal effects on glucose tolerance, and we find that this schedule has a reduced impact on pyruvate tolerance, fasting glucose and insulin levels, beta cell function, and the immune system compared to daily rapamycin treatment. Further, we find that the FDA-approved rapamycin analogs everolimus and temsirolimus efficiently inhibit mTORC1 while having a reduced impact on glucose and pyruvate tolerance. Our results suggest that many of the negative side effects of rapamycin treatment can be mitigated through intermittent dosing or the use of rapamycin analogs. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Feedback regulation of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 via ATM/Chk2 pathway contributes to the resistance of MCF-7 breast cancer cells to cisplatin.

PubMed

Lv, Juan; Qian, Ying; Ni, Xiaoyan; Xu, Xiuping; Dong, Xuejun

2017-03-01

The methyl methanesulfonate and ultraviolet-sensitive gene clone 81 protein is a structure-specific nuclease that plays important roles in DNA replication and repair. Knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 has been found to sensitize cancer cells to chemotherapy. However, the underlying molecular mechanism is not well understood. We found that methyl methanesulfonate and ultraviolet-sensitive gene clone 81 was upregulated and the ATM/Chk2 pathway was activated at the same time when MCF-7 cells were treated with cisplatin. By using lentivirus targeting methyl methanesulfonate and ultraviolet-sensitive gene clone 81 gene, we showed that knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 enhanced cell apoptosis and inhibited cell proliferation in MCF-7 cells under cisplatin treatment. Abrogation of ATM/Chk2 pathway inhibited cell viability in MCF-7 cells in response to cisplatin. Importantly, we revealed that ATM/Chk2 was required for the upregulation of methyl methanesulfonate and ultraviolet-sensitive gene clone 81, and knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 resulted in inactivation of ATM/Chk2 pathway in response to cisplatin. Meanwhile, knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 activated the p53/Bcl-2 pathway in response to cisplatin. These data suggest that the ATM/Chk2 may promote the repair of DNA damage caused by cisplatin by sustaining methyl methanesulfonate and ultraviolet-sensitive gene clone 81, and the double-strand breaks generated by methyl methanesulfonate and ultraviolet-sensitive gene clone 81 may activate the ATM/Chk2 pathway in turn, which provide a novel mechanism of how methyl methanesulfonate and ultraviolet-sensitive gene clone 81 modulates DNA damage response and repair.

Evaluation of the skin sensitization potential of chemicals using expression of co-stimulatory molecules, CD54 and CD86, on the naive THP-1 cell line.

PubMed

Yoshida, Y; Sakaguchi, H; Ito, Y; Okuda, M; Suzuki, H

2003-04-01

It has been known that dendritic cells (DCs) including Langerhans cells (LCs) play a critical role in the skin sensitization process. Many attempts have been made to develop in vitro sensitization tests that employ DCs derived from peripheral blood mononuclear cells (PBMC-DC) or CD34+ hematopoietic progenitor cells (CD34+ HPC) purified from cord blood or bone marrow. However, the use of the DCs in in vitro methods has been difficult due to the nature of these cells such as low levels in the source and/or donor-to-donor variability. In our studies, we employed the human monocytic leukemia cell line, THP-1, in order to avoid some of these difficulties. At the start, we examined whether treatment of the cells with various cytokines could produce DCs from THP-1. Treatment of THP-1 cells with cytokines such as GM-CSF, IL-4, TNF-alpha, and/or PMA did induce some phenotypic changes in THP-1 cells that were characteristic of DCs. Subsequently, responses to a known sensitizer, dinitrochlorobenzene (DNCB), and a non-sensitizer, dimethyl sulfoxide (DMSO) or sodium lauryl sulfate (SLS), on the expression of co-stimulatory molecules, CD54 and CD86, were examined between the naive cells and the cytokine-treated cells. Interestingly, the naive THP-1 cells responded only to DNCB and the response to the sensitizer was more distinct than cytokine-treated THP-1 cells. Similar phenomena were also observed in the human myeloid leukemia cell line, KG-1. Furthermore, with treatment of DNCB, naive THP-1 cells showed augmented expression of HLA, CD80 and secretion of IL-1 beta. The response of THP-1 cells to a sensitizer was similar to that of LCs/DCs. Upon demonstrating the differentiation of monocyte cells in our system, we then evaluated a series of chemicals, including known sensitizers and non-sensitizers, for their potential to augment CD54 and CD86 expression on naive THP-1 cells. Indeed, known sensitizers such as PPD and 2-MBT significantly augmented CD54 and CD86 expression in a dose-dependent manner while non-sensitizers, such as SLS and methyl salicylate (MS), did not. To note, the metal allergens such as (NH(4))(2)[PtCl(4)], NiSO(4) and CoSO(4) augmented significantly only CD54 expression. Taking advantage of a cultured cell line, measurement of the co-stimulatory molecules, CD54 and CD86, on naive THP-1 cells following chemical exposure shows promise for the development of a simple, short-term in vitro sensitization test.

Sensitivity, predictive values, pretest-posttest probabilities, and likelihood ratios of presurgery clinical diagnosis of nonmelanoma skin cancers.

PubMed

Ermertcan, Aylin Türel; Oztürk, Ferdi; Gençoğlan, Gülsüm; Eskiizmir, Görkem; Temiz, Peyker; Horasan, Gönül Dinç

2011-03-01

The precision of clinical diagnosis of skin tumors is not commonly measured and, therefore, very little is known about the diagnostic ability of clinicians. This study aimed to compare clinical and histopathologic diagnoses of nonmelanoma skin cancers with regard to sensitivity, predictive values, pretest-posttest probabilities, and likelihood ratios. Two hundred nineteen patients with 241 nonmelanoma skin cancers were enrolled in this study. Of these patients, 49.4% were female and 50.6% were male. The mean age ± standard deviation (SD) was 63.66 ± 16.44 years for the female patients and 64.77 ± 14.88 years for the male patients. The mean duration of the lesions was 20.90 ± 32.95 months. One hundred forty-eight (61.5%) of the lesions were diagnosed as basal cell carcinoma (BCC) and 93 (38.5%) were diagnosed as squamous cell carcinoma (SCC) histopathologically. Sensitivity, positive predictive value, and posttest probability were calculated as 75.96%, 87.77%, and 87.78% for BCC and 70.37%, 37.25%, and 37.20% for SCC, respectively. The correlation between clinical and histopathologic diagnoses was found to be higher in BCC. Knowledge of sensitivity, predictive values, likelihood ratios, and posttest probabilities may have implications for the management of skin cancers. To prevent unnecessary surgeries and achieve high diagnostic accuracies, multidisciplinary approaches are recommended.

Mitochondrial Metabolism in Aging Heart

PubMed Central

Lesnefsky, Edward J.; Chen, Qun; Hoppel, Charles L.

2016-01-01

Altered mitochondrial metabolism is the underlying basis for the increased sensitivity in the aged heart to stress. The aged heart exhibits impaired metabolic flexibility, with a decreased capacity to oxidize fatty acids and enhanced dependence on glucose metabolism. Aging impairs mitochondrial oxidative phosphorylation, with a greater role played by the mitochondria located between the myofibrils, the interfibrillar mitochondria. With aging, there is a decrease in activity of complexes III and IV, which account for the decrease in respiration. Furthermore, aging decreases mitochondrial content among the myofibrils. The end result is that in the interfibrillar area there is an approximate 50% decrease in mitochondrial function, affecting all substrates. The defective mitochondria persist in the aged heart, leading to enhanced oxidant production and oxidative injury and the activation of oxidant signaling for cell death. Aging defects in mitochondria represent new therapeutic targets, whether by manipulation of the mitochondrial proteome, modulation of electron transport, activation of biogenesis or mitophagy, or the regulation of mitochondrial fission and fusion. These mechanisms provide new ways to attenuate cardiac disease in elders by preemptive treatment of age-related defects, in contrast to the treatment of disease-induced dysfunction. PMID:27174952

Oxidative Stress Function in Women over 40 Years of Age, Considering Their Lifestyle.

PubMed

Gonçalves Mota, Maria Paula; Santos, Zirlene; Soares, Jorge; Pereira, Ana; Fonseca, Sandra; Peixoto, Francisco; Gaivão, Isabel; Oliveira, Maria

2017-01-01

Aging is dependent on biological processes that determine the aging of the organism at the cellular level. The Oxidative Stress Theory of Aging might explain some of the age-related changes in cell macromolecules. Moreover, exposome and lifestyle may also induce changes in cell damage induced by oxidative stress. The aim of the present study was to analyze the related redox changes in lymphocyte function of healthy women over 40 years old. Three groups: younger (YG: 40-49 years), middle aged (MAG: 50-59 years), and older (OG: ≥60 years) were evaluated on anthropometric variables, blood pressure, cardiovascular fitness, lifestyle habits, perceived stress, DNA damage, malondialdehyde, catalase activity, and total antioxidant capacity. Physical activity and cardiovascular fitness were significantly higher in YG and MAG as compared to the OG. Systolic blood pressure increased significantly with group age. Frequency and total amount of alcohol intake were lower in the OG and higher in the MAG. No significant differences were observed between the three groups in oxidative stress parameters. Only alcohol consumption was associated with the higher DNA FPG-sensitive sites, and only in the YG ( p  < 0.05). Healthy lifestyle is critical to avoiding major ailments associated with aging. This may be inferred from the lack of significant differences in the various oxidative stress parameters measured in the healthy women over the age of 40 who took part in the study. Conscious lifestyle behaviors (decrease in alcohol and smoking habits) could have impaired the expected age-related oxidative stress increase.

Peripheral leukocyte populations and oxidative stress biomarkers in aged dogs showing impaired cognitive abilities.

PubMed

Mongillo, Paolo; Bertotto, Daniela; Pitteri, Elisa; Stefani, Annalisa; Marinelli, Lieta; Gabai, Gianfranco

2015-06-01

In the present study, the peripheral blood leukocyte phenotypes, lymphocyte subset populations, and oxidative stress parameters were studied in cognitively characterized adult and aged dogs, in order to assess possible relationships between age, cognitive decline, and the immune status. Adult (N = 16, 2-7 years old) and aged (N = 29, older than 8 years) dogs underwent two testing procedures, for the assessment of spatial reversal learning and selective social attention abilities, which were shown to be sensitive to aging in pet dogs. Based on age and performance in cognitive testing, dogs were classified as adult not cognitively impaired (ADNI, N = 12), aged not cognitively impaired (AGNI, N = 19) and aged cognitively impaired (AGCI, N = 10). Immunological and oxidative stress parameters were compared across groups with the Kruskal-Wallis test. AGCI dogs displayed lower absolute CD4 cell count (p < 0.05) than ADNI and higher monocyte absolute count and percentage (p < 0.05) than AGNI whereas these parameters were not different between AGNI and ADNI. AGNI dogs had higher CD8 cell percentage than ADNI (p < 0.05). Both AGNI and AGCI dogs showed lower CD4/CD8 and CD21 count and percentage and higher neutrophil/lymphocyte and CD3/CD21 ratios (p < 0.05). None of the oxidative parameters showed any statistically significant difference among groups. These observations suggest that alterations in peripheral leukocyte populations may reflect age-related changes occurring within the central nervous system and disclose interesting perspectives for the dog as a model for studying the functional relationship between the nervous and immune systems during aging.

The relevance of memory sensitivity for psychological well-being in aging.

PubMed

Toffalini, Enrico; Borella, Erika; Cornoldi, Cesare; De Beni, Rossana

2016-08-01

In the present study, we investigated the relationship between memory sensitivity, which describes a positive attitude to autobiographical memory and the presence of behaviors devoted to saving memories of the personal past, and psychological well-being; in particular, we tested whether their relationship would change across age groups. Three hundred eighteen participants, divided in four groups: young to middle-aged adults (20-55 years old), young-old adults (65-74 years old), old adults (75-84 years old), and old-old adults (85-97 years old), completed questionnaires on their memory sensitivity and psychological well-being. Memory sensitivity slightly decreased with age and had a positive relationship with psychological well-being that was critically moderated by age. Specifically, the relationship between memory sensitivity and psychological well-being became increasingly stronger as age increased. While memory sensitivity may have little or no particular relevance in the case of young to middle-aged adults, it has an increasingly important positive relationship with psychological well-being at later age. It is thus suggested that memory sensitivity represents a dimension that should be considered in the study and interventions on quality of life in the elderly population.

The influence of L-opsin gene polymorphisms and neural ageing on spatio-chromatic contrast sensitivity in 20-71 year olds.

PubMed

Dees, Elise W; Gilson, Stuart J; Neitz, Maureen; Baraas, Rigmor C

2015-11-01

Chromatic contrast sensitivity may be a more sensitive measure of an individual's visual function than achromatic contrast sensitivity. Here, the first aim was to quantify individual- and age-related variations in chromatic contrast sensitivity to a range of spatial frequencies for stimuli along two complementary directions in color space. The second aim was to examine whether polymorphisms at specific amino acid residues of the L- and M-opsin genes (OPN1LW and OPN1MW) known to affect spectral tuning of the photoreceptors could influence spatio-chromatic contrast sensitivity. Chromatic contrast sensitivity functions were measured in 50 healthy individuals (20-71 years) employing a novel pseudo-isochromatic grating stimulus. The spatio-chromatic contrast sensitivity functions were found to be low pass for all subjects, independent of age and color vision. The results revealed a senescent decline in spatio-chromatic contrast sensitivity. There were considerable between-individual differences in sensitivity within each age decade for individuals 49 years old or younger, and age did not predict sensitivity for these age decades alone. Forty-six subjects (including a color deficient male and eight female carriers) were genotyped for L- and M-opsin genes. The Ser180Ala polymorphisms on the L-opsin gene were found to influence the subject's color discrimination and their sensitivity to spatio-chromatic patterns. The results expose the significant role of neural and genetic factors in the deterioration of visual function with increasing age. Copyright © 2015 Elsevier Ltd. All rights reserved.

Probiotic treatment during neonatal age provides optimal protection against experimental asthma through the modulation of microbiota and T cells.

PubMed

Nunes, Caroline Fraga; Nogueira, Jeane S; Vianna, Pedro Henrique Oliveira; Ciambarella, Bianca Torres; Rodrigues, Patrícia Machado; Miranda, Karla Rodrigues; Lobo, Leandro Araújo; Domingues, Regina Maria Cavalcanti Pillotto; Busch, Mileane; Atella, Georgia Correa; Vale, André Macedo; Bellio, Maria; Nóbrega, Alberto; Canto, Fábio B; Fucs, Rita

2018-04-03

The incidence of allergic diseases, which increased to epidemic proportions in developed countries over the last few decades, has been correlated with altered gut microbiota colonization. Although probiotics may play a critical role in the restoration of gut homeostasis, their efficiency in the control of allergy is controversial. Here, we aimed to investigate the effects of probiotic treatment initiated at neonatal or adult ages on the suppression of experimental ovalbumin (OVA)-induced asthma. Neonatal or adult mice were orally treated with probiotic bacteria and subjected to OVA-induced allergy. Asthma-like symptoms, microbiota composition and frequencies of the total CD4+ T lymphocytes and CD4+Foxp3+ regulatory T (Treg) cells were evaluated in both groups. Probiotic administration to neonates, but not to adults, was necessary and sufficient for the absolute prevention of experimental allergen-induced sensitization. The neonatally acquired tolerance, transferrable to probiotic-untreated adult recipients by splenic cells from tolerant donors, was associated with modulation of gut bacterial composition, augmented levels of cecum butyrate and selective accumulation of Treg cells in the airways. Our findings reveal that a cross-talk between a healthy microbiota and qualitative features inherent to neonatal T cells, especially in the Treg cell subset, might support the beneficial effect of perinatal exposure to probiotic bacteria on the development of long-term tolerance to allergens.

Murine maternal cell microchimerism: analysis using real-time PCR and in vivo imaging1

PubMed Central

Su, Eric C.; Johnson, Kirby L.; Tighiouart, Hocine; Bianchi, Diana W.

2009-01-01

In humans, maternal cells are present in the affected tissues of children with inflammatory myopathy, scleroderma, and neonatal lupus. It is unknown if maternal cell microchimerism (MCM) contributes to the pathology of disease. We sought to understand the factors that affect MCM to serve as a baseline for future mechanistic studies. Using a mouse model, we bred female mice transgenic for the luciferase (Luc) reporter gene to wild type (WT) males. The WT offspring were sacrificed at various postnatal ages. DNA was extracted from multiple organs and real-time PCR amplification was used to quantify Luc transgene as a marker for maternally derived cells. Sensitivity was 1 to 2 transgenic cells per 100,000 WT cells. MCM was noted in 85% of mice and 45% of tissues assayed. The average quantity of MCM was 158 maternal cells per 100,000 neonatal cells. The organs displaying the highest frequency and quantity of MCM were heart and lung (p<0.001). Postnatal age up to 21 days did not appear to affect levels of MCM (p=0.47), whereas increasing parity may increase levels of MCM. The data show that MCM is a common occurrence in healthy newborn mice, is present in their major organs, and that there are organ specific differences. This may represent differential migration of maternal cells, or varying receptivity of specific fetal organs to microchimerism. Pregnancy history appears to play a role in maternal cell trafficking. The role of MCM in pregnancy and disease pathogenesis remains to be elucidated. PMID:18256332

Spectral and Polarization Sensitivity of the Dipteran Visual System

PubMed Central

McCann, Gilbert D.; Arnett, David W.

1972-01-01

Spectral and polarization sensitivity measurements were made at several levels (retina, first and third optic ganglion, cervical connective, behavior) of the dipteran visual nervous system. At all levels, it was possible to reveal contributions from the retinular cell subsystem cells 1 to 6 or the retinular cell subsystem cells 7 and 8 or both. Only retinular cells 1 to 6 were directly studied, and all possessed the same spectral sensitivity characterized by two approximately equal sensitivity peaks at 350 and 480 nm. All units of both the sustaining and on-off variety in the first optic ganglion exhibited the same spectral sensitivity as that of retinular cells 1 to 6. It was possible to demonstrate for motion detection and optomotor responses two different spectral sensitivities depending upon the spatial wavelength of the stimulus. For long spatial wavelengths, the spectral sensitivity agreed with retinular cells 1 to 6; however, the spectral sensitivity at short spatial wavelengths was characterized by a single peak at 465 nm reflecting contributions from the (7, 8) subsystem. Although the two subsystems exhibited different spectral sensitivities, the difference was small and no indication of color discrimination mechanisms was observed. Although all retinular cells 1 to 6 exhibited a preferred polarization plane, sustaining and on-off units did not. Likewise, motion detection and optomotor responses were insensitive to the polarization plane for long spatial wavelength stimuli; however, sensitivity to select polarization planes was observed for short spatial wavelengths. PMID:5027759

The interplay of maternal sensitivity and toddler engagement of mother in predicting self-regulation.

PubMed

Ispa, Jean M; Su-Russell, Chang; Palermo, Francisco; Carlo, Gustavo

2017-03-01

Using data from the Early Head Start Research and Evaluation Project, a cross-lag mediation model was tested to examine longitudinal relations among low-income mothers' sensitivity; toddlers' engagement of their mothers; and toddler's self-regulation at ages 1, 2, and 3 years (N = 2,958). Age 1 maternal sensitivity predicted self-regulation at ages 2 and 3 years, and age 2 engagement of mother mediated the relation between age 1 maternal sensitivity and age 3 self-regulation. Lagged relations from toddler self-regulation at ages 1 and 2 years to later maternal sensitivity were not significant, suggesting stronger influence from mother to toddler than vice versa. Model fit was similar regardless of child gender and depth of family poverty. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Poor repair of skeletal muscle in aging mice reflects a defect in local, interleukin-33-dependent, accumulation of regulatory T cells

PubMed Central

Kuswanto, Wilson; Burzyn, Dalia; Panduro, Marisella; Wang, Kathy K.; Jang, Young Charles; Wagers, Amy J.; Benoist, Christophe; Mathis, Diane

2016-01-01

SUMMARY Normal repair of skeletal muscle requires local expansion of a special population of Foxp3+CD4+ regulatory T (Treg) cells. Such cells failed to accumulate in acutely injured muscle of old mice, known to undergo ineffectual repair. This defect reflected reduced recruitment of Treg cells to injured muscle, as well as less proliferation and retention therein. Interleukin (IL)-33 regulated muscle Treg cell homeostasis in young mice, and its administration to old mice ameliorated their deficits in Treg cell accumulation and muscle regeneration. The major IL-33-expressing cells in skeletal muscle displayed a constellation of markers diagnostic of fibro/adipogenic progenitor cells, and were often associated with neural structures, including nerve fibers, nerve bundles and muscle spindles, which are stretch-sensitive mechanoreceptors important for proprioception. IL-33+ cells were more frequent after muscle injury, and were reduced in old mice. IL-33 is well situated to relay signals between the nervous and immune systems within the muscle context. PMID:26872699

Spectral sensitization of nanocrystalline solar cells

DOEpatents

Spitler, Mark T.; Ehret, Anne; Stuhl, Louis S.

2002-01-01

This invention relates to dye sensitized polycrystalline photoelectrochemical solar cells for use in energy transduction from light to electricity. It concerns the utility of highly absorbing organic chromophores as sensitizers in such cells and the degree to which they may be utilized alone and in combination to produce an efficient photoelectrochemical cell, e.g., a regenerative solar cell.

Interfacial Effects in Solid-Liquid Electrolytes for Improved Stability and Performance of Dye-Sensitized Solar Cells.

PubMed

Bella, Federico; Popovic, Jelena; Lamberti, Andrea; Tresso, Elena; Gerbaldi, Claudio; Maier, Joachim

2017-11-01

With the purpose of achieving stable dye-sensitized solar cells (DSSCs) with high efficiency, a new type of soft matter electrolyte is tested in which specific amounts of nanosized silica particles are finely dispersed in short-chained polyethylene glycol dimethylether encompassing an iodide/triiodide redox mediator. This results in a solid-liquid composite having synergistic electrical and favorable mechanical properties. The combination of interfacial effects and particle network formation promotes enhanced ion transport, which directly impacts the short-circuit photocurrent density. Thorough analysis reveals that this newly elaborated class of electrolytes is able to improve, at the same time, the thermal and long-term stability of DSSCs, as well as power conversion efficiency under standard and lower irradiation intensities. Lab-scale devices with champion efficiency exceeding 11% under attenuated sunlight (20 mW cm -2 , with a compact TiO 2 blocking layer) are obtained, along with impressively stable performance under both thermal stress and light soaking in an indoor environment (>96% performance retention after 2500 h of accelerated aging under full sun alternated with thermal ramps), matching the durability criteria applied to silicon solar cells for outdoor applications. The new findings might foster widespread practical application of DSSCs.

Resveratrol-Sensitized UVA Induced Apoptosis in Human Keratinocytes through Mitochondrial Oxidative Stress and Pore Opening

PubMed Central

Boyer, Jean Z; Jandova, Jana; Janda, Jaroslav; Vleugels, Frank R; Elliott, David; Sligh, James E

2012-01-01

Resveratrol (3, 5, 4′-trihydroxy- trans- stilbene), a polyphenol compound, is derived from natural products such as the skin of red grapes, blueberries and cranberries. Resveratrol not only exhibits antioxidant, cardioprotection, and anti-aging properties, but can also inhibit cancer cell growth and induce apoptosis. It has been shown that resveratrol inhibits the activation of Nf-kB and subsequently down regulates the expression of Nf-kB regulated genes such as interleukin-2 and Bcl-2, leading to cell cycle arrest and increased apoptosis in multiple myeloma cells. In the skin, resveratrol has been reported to sensitize keratinocytes to UVA induced apoptosis. However, the effect of resveratrol on opening of the mitochondrial permeability transition pore has not been previously examined. Our data show that UVA (14J/cm2) along with resveratrol causes massive oxidative stress in mitochondria. As a consequence of oxidative stress, the mitochondrial membrane potential decreases which results in opening of the mitochondrial pores ultimately leading to apoptosis in human keratinocytes. These results may have clinical implications for development of future chemotherapeutic treatment for tumors of the skin. PMID:22673012

Sensitization by heat treatment of Escherichia coli K-12 cells to hydrophobic antibacterial compounds.

PubMed Central

Tsuchido, T; Takano, M

1988-01-01

The sensitivities of intact and heat-injured cells of Escherichia coli K-12 to several antibacterial compounds were measured by the prolongation of growth delay. Cells exposed to sublethal heat became more sensitive to various hydrophobic compounds, such as medium-chain fatty acids, alkyl esters of p-hydroxybenzoic acid, and some kinds of antibiotics or dyes, than unheated cells; but there was a smaller or no increase in sensitivity to short-chain fatty acids, chloramphenicol, and vancomycin. The destruction by heat of a permeability barrier of the outer membrane may have sensitized the cells to hydrophobic compounds. The sensitization was much lower for a strain defective in lipopolysaccharide, which is important as a barrier against hydrophobic compounds. PMID:3075437

RAGE-dependent activation of gene expression of superoxide dismutase and vanins by AGE-rich extracts in mice cardiac tissue and murine cardiac fibroblasts.

PubMed

Leuner, Beatrice; Ruhs, Stefanie; Brömme, Hans-Jürgen; Bierhaus, Angelika; Sel, Saadettin; Silber, Rolf-Edgar; Somoza, Veronika; Simm, Andreas; Nass, Norbert

2012-10-01

Advanced glycation end products (AGEs) are stable compounds formed from initial Maillard reaction products. They are considered as markers for ageing and often associated with age-related, degenerative diseases. Bread crust represents an established model for nutritional compounds rich in AGEs and is able to induce antioxidative defense genes such as superoxide dismutases and vanins in cardiac cells. The aim of this study was to investigate to what extend the receptor for AGEs (RAGE) contributes to this response. Signal transduction in response to bread crust extract was analysed in cardiac fibroblasts derived from C57/B6-NCrl (RAGE +/+) and the corresponding RAGE-knock out C57/B6-NCrl mouse strain (RAGE -/-). Activation of superoxide dismutases in animals was then analysed upon bread crust feeding in these two mice strains. Cardiac fibroblasts from RAGE -/- mice did not express RAGE, but the expression of AGER-1 and AGER-3 was up-regulated, whereas the expression of SR-B1 was down-regulated. RAGE -/- cells were less sensitive to BCE in terms of MAP-kinase phosphorylation and NF-κB reporter gene activation. Bread crust extract induced mRNA levels of MnSOD and Vnn-1 were also reduced in RAGE -/- cells, whereas Vnn-3 mRNA accumulation seemed to be RAGE receptor independent. In bread crust feeding experiments, RAGE -/- mice did not exhibit an activation of MnSOD-mRNA and -protein accumulation as observed for the RAGE +/+ animals. In conclusion, RAGE was clearly a major factor for the induction of antioxidant defense signals derived from bread crust in cardiac fibroblast and mice. Nevertheless higher doses of bread crust extract could overcome the RAGE dependency in cell cultures, indicating that additional mechanisms are involved in BCE-mediated activation of SOD and vanin expression.

Differential Regulation of Mouse B Cell Development by Transforming Growth Factor β1

PubMed Central

Kaminski, Denise A.; Letterio, John J.; Burrows, Peter D.

2002-01-01

Transforming growth factor β (TGFβ) can inhibit the in vitro proliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1-/- mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1- pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1+ pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell development in vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation. PMID:12739785

Optimizing cryopreservation of human spermatogonial stem cells: comparing the effectiveness of testicular tissue and single cell suspension cryopreservation

PubMed Central

Yango, Pamela; Altman, Eran; Smith, James F.; Klatsky, Peter C.; Tran, Nam D.

2015-01-01

Objective To determine whether optimal human spermatogonial stem cell (SSC) cryopreservation is best achieved with testicular tissue or single cell suspension cryopreservation. This study compares the effectiveness between these two approaches by using testicular SSEA-4+ cells, a known population containing SSCs. Design In vitro human testicular tissues. Setting Academic research unit. Patients Adult testicular tissues (n = 4) collected from subjects with normal spermatogenesis and normal fetal testicular tissues (n = 3). Intervention(s) Testicular tissue vs. single cell suspension cryopreservation. Main Outcome Measures Cell viability, total cell recovery per milligram of tissue, as well as, viable and SSEA-4+ cell recovery. Results Single cell suspension cryopreservation yielded higher recovery of SSEA-4+ cells enriched in adult SSCs whereas fetal SSEA-4+ cell recovery was similar between testicular tissue and single cell suspension cryopreservation. Conclusions Adult and fetal human SSEA-4+ populations exhibited differential sensitivity to cryopreservation based on whether they were cryopreserved in situ as testicular tissues or as single cells. Thus, optimal preservation of human SSCs depends on the patient age, type of samples cryopreserved, and end points of therapeutic applications. PMID:25241367

Fatty Acid Synthase Cooperates with Glyoxalase 1 to Protect against Sugar Toxicity

PubMed Central

Garrido, Damien; Rubin, Thomas; Poidevin, Mickael; Maroni, Brigitte; Le Rouzic, Arnaud; Parvy, Jean-Philippe; Montagne, Jacques

2015-01-01

Fatty acid (FA) metabolism is deregulated in several human diseases including metabolic syndrome, type 2 diabetes and cancers. Therefore, FA-metabolic enzymes are potential targets for drug therapy, although the consequence of these treatments must be precisely evaluated at the organismal and cellular levels. In healthy organism, synthesis of triacylglycerols (TAGs)—composed of three FA units esterified to a glycerol backbone—is increased in response to dietary sugar. Saturation in the storage and synthesis capacity of TAGs is associated with type 2 diabetes progression. Sugar toxicity likely depends on advanced-glycation-end-products (AGEs) that form through covalent bounding between amine groups and carbonyl groups of sugar or their derivatives α-oxoaldehydes. Methylglyoxal (MG) is a highly reactive α-oxoaldehyde that is derived from glycolysis through a non-enzymatic reaction. Glyoxalase 1 (Glo1) works to neutralize MG, reducing its deleterious effects. Here, we have used the power of Drosophila genetics to generate Fatty acid synthase (FASN) mutants, allowing us to investigate the consequence of this deficiency upon sugar-supplemented diets. We found that FASN mutants are lethal but can be rescued by an appropriate lipid diet. Rescued animals do not exhibit insulin resistance, are dramatically sensitive to dietary sugar and accumulate AGEs. We show that FASN and Glo1 cooperate at systemic and cell-autonomous levels to protect against sugar toxicity. We observed that the size of FASN mutant cells decreases as dietary sucrose increases. Genetic interactions at the cell-autonomous level, where glycolytic enzymes or Glo1 were manipulated in FASN mutant cells, revealed that this sugar-dependent size reduction is a direct consequence of MG-derived-AGE accumulation. In summary, our findings indicate that FASN is dispensable for cell growth if extracellular lipids are available. In contrast, FA-synthesis appears to be required to limit a cell-autonomous accumulation of MG-derived-AGEs, supporting the notion that MG is the most deleterious α-oxoaldehyde at the intracellular level. PMID:25692475

Reducing mTOR augments parietal epithelial cell density in a model of acute podocyte depletion and in aged kidneys

PubMed Central

McNicholas, Bairbre A.; Eng, Diana G.; Lichtnekert, Julia; Rabinowitz, Peter S.; Pippin, Jeffrey W.

2016-01-01

Parietal epithelial cell (PEC) response to glomerular injury may underlie a common pathway driving fibrogenesis following podocyte loss that typifies several glomerular disorders. Although the mammalian target of rapamycin (mTOR) pathway is important in cell homeostasis, little is known of the biological role or impact of reducing mTOR activity on PEC response following podocyte depletion, nor in the aging kidney. The purpose of these studies was to determine the impact on PECs of reducing mTOR activity following abrupt experimental depletion in podocyte number, as well as in a model of chronic podocyte loss and sclerosis associated with aging. Podocyte depletion was induced by an anti-podocyte antibody and rapamycin started at day 5 until death at day 14. Reducing mTOR did not lead to a greater reduction in podocyte density, despite greater glomerulosclerosis. However, mTOR inhibition lead to an increase in PEC density and PEC-derived crescent formation. Additionally, markers of epithelial-to-mesenchymal transition (platelet-derived growth factor receptor-β, α-smooth muscle actin, Notch-3) and PEC activation (CD44, collagen IV) were further increased by mTOR reduction. Aged mice treated with rapamycin for 1, 2, and 10 wk before death at 26.5 mo (≈75-yr-old human age) had increased the number of glomeruli with a crescentic appearance. mTOR inhibition at either a high or low level lead to changes in PEC phenotype, indicating PEC morphology is sensitive to changes mediated by global mTOR inhibition. PMID:27440779

Aptamer-Functionalized Fluorescent Silica Nanoparticles for Highly Sensitive Detection of Leukemia Cells

NASA Astrophysics Data System (ADS)

Tan, Juntao; Yang, Nuo; Hu, Zixi; Su, Jing; Zhong, Jianhong; Yang, Yang; Yu, Yating; Zhu, Jianmeng; Xue, Dabin; Huang, Yingying; Lai, Zongqiang; Huang, Yong; Lu, Xiaoling; Zhao, Yongxiang

2016-06-01

A simple, highly sensitive method to detect leukemia cells has been developed based on aptamer-modified fluorescent silica nanoparticles (FSNPs). In this strategy, the amine-labeled Sgc8 aptamer was conjugated to carboxyl-modified FSNPs via amide coupling between amino and carboxyl groups. Sensitivity and specificity of Sgc8-FSNPs were assessed using flow cytometry and fluorescence microscopy. These results showed that Sgc8-FSNPs detected leukemia cells with high sensitivity and specificity. Aptamer-modified FSNPs hold promise for sensitive and specific detection of leukemia cells. Changing the aptamer may allow the FSNPs to detect other types of cancer cells.

Aging in Sensory and Motor Neurons Results in Learning Failure in Aplysia californica.

PubMed

Kempsell, Andrew T; Fieber, Lynne A

2015-01-01

The physiological and molecular mechanisms of age-related memory loss are complicated by the complexity of vertebrate nervous systems. This study takes advantage of a simple neural model to investigate nervous system aging, focusing on changes in learning and memory in the form of behavioral sensitization in vivo and synaptic facilitation in vitro. The effect of aging on the tail withdrawal reflex (TWR) was studied in Aplysia californica at maturity and late in the annual lifecycle. We found that short-term sensitization in TWR was absent in aged Aplysia. This implied that the neuronal machinery governing nonassociative learning was compromised during aging. Synaptic plasticity in the form of short-term facilitation between tail sensory and motor neurons decreased during aging whether the sensitizing stimulus was tail shock or the heterosynaptic modulator serotonin (5-HT). Together, these results suggest that the cellular mechanisms governing behavioral sensitization are compromised during aging, thereby nearly eliminating sensitization in aged Aplysia.

Immune suppression with supraoptimal doses of antigen in contact sensitivity. I. Demonstration of suppressor cells and their sensitivity to cyclophosphamide.

PubMed

Sy, M S; Miller, S D; Claman, H N

1977-07-01

Immunologic suppression was induced in a mouse model of contact sensitization to DNFB by using supraoptimal doses of antigen. In these studies, in vivo measurement of ear swelling as an indication of immunologic responsiveness correlated well with measurement of in vitro antigen-induced cell proliferation. This unresponsiveness was specific, since supraoptimal doses of DNFB did not interfere with the development of contact sensitivity to another contactant, oxazolone. The decrease in responsiveness is a form of active suppression, as lymphoid cells from supraoptimally sensitized donors transferred suppression to normal recipients. Furthermore, pretreatment with cyclophosphamide (Cy) reversed the suppression seen in supraoptimally sensitized animals but had no effect on the optimal sensitization regimen. These results indicate that supraoptimal doses of contactants can activate suppressor cells and that precursors of these cells are sensitive to Cy. Such suppressors regenerate within 7 to 14 days after Cy treatment. The ability of Cy pretreatment to affect supraoptimal sensitization without affecting optimal sensitization confirms other reports indicating that the observed results of Cy treatment depend critically upon the dose of antigen used.

The metabolites in peripheral blood mononuclear cells showed greater differences between patients with impaired fasting glucose or type 2 diabetes and healthy controls than those in plasma.

PubMed

Kim, Minjoo; Kim, Minkyung; Han, Ji Yun; Lee, Sang-Hyun; Jee, Sun Ha; Lee, Jong Ho

2017-03-01

To determine differences between peripheral blood mononuclear cells and the plasma metabolites in patients with impaired fasting glucose or type 2 diabetes and healthy controls. In all, 65 nononobese patients (aged 30-70 years) with impaired fasting glucose or type 2 diabetes and 65 nonobese sex-matched healthy controls were included, and fasting peripheral blood mononuclear cell and plasma metabolomes were profiled. The diabetic or impaired fasting glucose patients showed higher circulating and peripheral blood mononuclear cell lipoprotein phospholipase A 2 activities, high-sensitivity C-reactive protein and tumour necrosis factor-α than controls. Compared with controls, impaired fasting glucose or diabetic subjects showed increases in 11 peripheral blood mononuclear cell metabolites: six amino acids (valine, leucine, methionine, phenylalanine, tyrosine and tryptophan), l-pyroglutamic acid, two fatty acid amides containing palmitic amide and oleamide and two lysophosphatidylcholines. In impaired fasting glucose or diabetic patients, peripheral blood mononuclear cell lipoprotein phospholipase A 2 positively associated with peripheral blood mononuclear cell lysophosphatidylcholines and circulating inflammatory markers, including tumour necrosis factor-α, high-sensitivity C-reactive protein and lipoprotein phospholipase A 2 activities. In plasma metabolites between patients and healthy controls, we observed significant increases in only three amino acids (proline, valine and leucine) and decreases in only five lysophosphatidylcholines. This study demonstrates significant differences in the peripheral blood mononuclear cell metabolome in patients with impaired fasting glucose or diabetes compared with healthy controls. These differences were greater than those observed in the plasma metabolome. These data suggest peripheral blood mononuclear cells as a useful tool to better understand the inflammatory pathophysiology of diabetes.

Validation of a Low-Cost Paper-Based Screening Test for Sickle Cell Anemia

PubMed Central

Piety, Nathaniel Z.; Yang, Xiaoxi; Kanter, Julie; Vignes, Seth M.; George, Alex; Shevkoplyas, Sergey S.

2016-01-01

Background The high childhood mortality and life-long complications associated with sickle cell anemia (SCA) in developing countries could be significantly reduced with effective prophylaxis and education if SCA is diagnosed early in life. However, conventional laboratory methods used for diagnosing SCA remain prohibitively expensive and impractical in this setting. This study describes the clinical validation of a low-cost paper-based test for SCA that can accurately identify sickle trait carriers (HbAS) and individuals with SCA (HbSS) among adults and children over 1 year of age. Methods and Findings In a population of healthy volunteers and SCA patients in the United States (n = 55) the test identified individuals whose blood contained any HbS (HbAS and HbSS) with 100% sensitivity and 100% specificity for both visual evaluation and automated analysis, and detected SCA (HbSS) with 93% sensitivity and 94% specificity for visual evaluation and 100% sensitivity and 97% specificity for automated analysis. In a population of post-partum women (with a previously unknown SCA status) at a primary obstetric hospital in Cabinda, Angola (n = 226) the test identified sickle cell trait carriers with 94% sensitivity and 97% specificity using visual evaluation (none of the women had SCA). Notably, our test permits instrument- and electricity-free visual diagnostics, requires minimal training to be performed, can be completed within 30 minutes, and costs about $0.07 in test-specific consumable materials. Conclusions Our results validate the paper-based SCA test as a useful low-cost tool for screening adults and children for sickle trait and disease and demonstrate its practicality in resource-limited clinical settings. PMID:26735691

The effects of topically applied glycolic acid and salicylic acid on ultraviolet radiation-induced erythema, DNA damage and sunburn cell formation in human skin.

PubMed

Kornhauser, Andrija; Wei, Rong-Rong; Yamaguchi, Yuji; Coelho, Sergio G; Kaidbey, Kays; Barton, Curtis; Takahashi, Kaoruko; Beer, Janusz Z; Miller, Sharon A; Hearing, Vincent J

2009-07-01

alpha-Hydroxy acids (alphaHAs) are reported to reduce signs of aging in the skin and are widely used cosmetic ingredients. Several studies suggest that alphaHA can increase the sensitivity of skin to ultraviolet radiation. More recently, beta-hydroxy acids (betaHAs), or combinations of alphaHA and betaHA have also been incorporated into antiaging skin care products. Concerns have also arisen about increased sensitivity to ultraviolet radiation following use of skin care products containing beta-HA. To determine whether topical treatment with glycolic acid, a representative alphaHA, or with salicylic acid, a betaHA, modifies the short-term effects of solar simulated radiation (SSR) in human skin. Fourteen subjects participated in this study. Three of the four test sites on the mid-back of each subject were treated daily Monday-Friday, for a total of 3.5 weeks, with glycolic acid (10%), salicylic acid (2%), or vehicle (control). The fourth site received no treatment. After the last treatment, each site was exposed to SSR, and shave biopsies from all four sites were obtained. The endpoints evaluated in this study were erythema (assessed visually and instrumentally), DNA damage and sunburn cell formation. Treatment with glycolic acid resulted in increased sensitivity of human skin to SSR, measured as an increase in erythema, DNA damage and sunburn cell formation. Salicylic acid did not produce significant changes in any of these biomarkers. Short-term topical application of glycolic acid in a cosmetic formulation increased the sensitivity of human skin to SSR, while a comparable treatment with salicylic acid did not.

The Effects of Topically Applied Glycolic Acid and Salicylic Acid on Ultraviolet Radiation-Induced Erythema, DNA Damage and Sunburn Cell Formation in Human Skin

PubMed Central

Kornhauser, Andrija; Wei, Rong-Rong; Yamaguchi, Yuji; Coelho, Sergio G.; Kaidbey, Kays; Barton, Curtis; Takahashi, Kaoruko; Beer, Janusz Z.; Miller, Sharon A.; Hearing, Vincent J.

2009-01-01

Background α-Hydroxy acids (αHA) are reported to reduce signs of aging in the skin and are widely used cosmetic ingredients. Several studies suggest that αHA can increase the sensitivity of skin to ultraviolet radiation. More recently, β-hydroxy acids (βHA), or combinations of αHA and βHA have also been incorporated into antiaging skin care products. Concerns have also arisen about increased sensitivity to ultraviolet radiation following use of skin care products containing β-HA. Objective To determine whether topical treatment with glycolic acid, a representative αHA, or with salicylic acid, a βHA, modifies the short-term effects of solar simulated radiation (SSR) in human skin. Methods Fourteen subjects participated in this study. Three of the four test sites on the mid-back of each subject were treated daily Monday - Friday, for a total of 3.5 weeks, with glycolic acid (10%), salicylic acid (2%), or vehicle (control). The fourth site received no treatment. After the last treatment, each site was exposed to SSR, and shave biopsies from all 4 sites were obtained. The endpoints evaluated in this study were erythema (assessed visually and instrumentally), DNA damage and sunburn cell formation. Results Treatment with glycolic acid resulted in increased sensitivity of human skin to SSR, measured as an increase in erythema, DNA damage and sunburn cell formation. Salicylic acid did not produce significant changes in any of these biomarkers. Conclusions Short-term topical application of glycolic acid in a cosmetic formulation increased the sensitivity of human skin to SSR, while a comparable treatment with salicylic acid did not. PMID:19411163

Improved Mitochondrial Function in Brain Aging and Alzheimer Disease – the New Mechanism of Action of the Old Metabolic Enhancer Piracetam

PubMed Central

Leuner, Kristina; Kurz, Christopher; Guidetti, Giorgio; Orgogozo, Jean-Marc; Müller, Walter E.

2010-01-01

Piracetam, the prototype of the so-called nootropic drugs’ is used since many years in different countries to treat cognitive impairment in aging and dementia. Findings that piracetam enhances fluidity of brain mitochondrial membranes led to the hypothesis that piracetam might improve mitochondrial function, e.g., might enhance ATP synthesis. This assumption has recently been supported by a number of observations showing enhanced mitochondrial membrane potential, enhanced ATP production, and reduced sensitivity for apoptosis in a variety of cell and animal models for aging and Alzheimer disease. As a specific consequence, substantial evidence for elevated neuronal plasticity as a specific effect of piracetam has emerged. Taken together, this new findings can explain many of the therapeutic effects of piracetam on cognition in aging and dementia as well as different situations of brain dysfunctions. PMID:20877425

Application of rat mast cell incubates as a possible short-time test for sensitizing occupational chemicals.

PubMed

Diel, F; Neidhart, B; Oprée, W

1981-01-01

The direct action of sensitizing occupational chemicals (formaldehyde, phenol, phenylhydrazine, p-aminophenol) on rat mast cells was investigated by determination of histamine using HPLC separation and fluorimetric detection. It turned out that dispensed mast cells from immunized and non-immunized Wistar-rats are more sensitive than small-cut lung tissue slices. Passive cutaneous anaphylaxis was negative after a fortnight sensitizing experiment with the here described occupational chemicals. Short-time tests with rat mast cells reflect anaphylactoid response and are suitable for the screening of sensitizing chemicals.

How to use … the Monospot and other heterophile antibody tests.

PubMed

Marshall-Andon, Tess; Heinz, Peter

2017-08-01

Epstein-Barr virus (EBV) is a highly prevalent virus, transmitted via saliva, which often causes asymptomatic infection in children but frequently results in infectious mononucleosis in adolescents. Heterophile antibody tests, including the Monospot test, are red cell or latex agglutination assays, which detect antired cell antibodies produced as part of a polyclonal antibody response occurring during EBV infection. Heterophile antibody tests are rapid, cheap and specific tests that can be performed from the onset of symptoms of infectious mononucleosis. In adolescents, heterophile antibody tests have high specificity and sensitivity in the diagnosis of primary acute EBV infection. However, the tests have low sensitivity and low negative predictive value in young children and are not useful under the age of 4. Heterophile tests may be positive in other viral infections, autoimmune disease and haematological malignancies, but do not appear to be positive in primary bacterial infection. Virus-specific serology is required in children under the age of 4 or if an older child is heterophile negative. Virus-specific serology allows diagnosis and the pattern of positivity and negativity enables the clinician to stage the EBV infection. Virus-specific serology appears to have better sensitivity in young children, but there is cross-reaction with other herpesvirus infections, a longer turnaround time and it is more expensive to perform. Further research is needed to establish which children benefit from and hence require testing for heterophile antibodies, the cost-effectiveness of EBV investigations and whether heterophile titres have predictive value for the severity of infection and the likelihood of complications. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

FAP-1 and NF-κB expressions in oral squamous cell carcinoma as potential markers for chemo-radio sensitivity and prognosis.

PubMed

Nariai, Y; Mishima, K; Yoshimura, Y; Sekine, J

2011-04-01

This study was designed to investigate the feasibility of using Fas-associated phosphatase-1 (FAP-1), nuclear factor kappa B (NF-κB) and p53 as markers for chemo-radio sensitivity in oral squamous cell carcinoma (OSCC). FAP-1 plays a role as an anti-apoptotic factor through Fas-dependent apoptosis after chemo-radiotherapy. NF-κB and p53 might be involved in modulation of FAP-1 expression. FAP-1, NF-κB and p53 expression were immunohistochemically examined using biopsy specimens in 50 OSCC patients treated with chemotherapy and/or radiotherapy. FAP-1 was expressed in 52%, NF-κB in 52% and p53 in 46% of patients. There was no significant difference in FAP-1, p53 or NF-κB expression according to the clinicopathological features. No correlation was found among FAP-1, p53 or NF-κB expression. FAP-1-positive cases showed a poorer survival rate than FAP-1-negative cases (P = 0.0409) and NF-κB-positive cases showed a poorer survival rate than NF-κB-negative cases (P = 0.0018). Multivariate analysis showed that FAP-1 expression, NF-κB expression, clinical stage and age were significant independent variables for survival (clinical stage: P = 0.0016; age: P = 0.0016; NF-κB: P = 0.0314; FAP-1: P = 0.0366). These results suggest that FAP-1 and NF-κB might play a role as chemo-radioresistant factor during chemo-radiotherapy, and FAP-1 and NF-κB expression in OSCC would be feasible markers for chemo-radio sensitivity and prognosis. Copyright © 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Proximal Gut Mucosal Epithelial Homeostasis in Aged IL-1 Type I Receptor Knockout Mice After Starvation

DTIC Science & Technology

2011-08-01

increases whole-body lean mass and insulin sensitivity in elderly subjects with sarcopenia . Am J Cardiol. 2008; 101:69E. [PubMed: 18157968] 11. Iwakiri R...nutritional deficiencies in the elderly can be corrected by nutritional supplementation [5-7], especially among patients who are fed enterally [8-10...mechanistic approach regarding intestinal cell dysfunction in the elderly . Starvation causes mucosal atrophy and loss of mucosal height [32], and glutamine

[Simultaneous onset of steroid-sensitive nephrotic syndrome and type 1 diabetes].

PubMed

Rego Filho, Eduardo A; Mello, Solange F R; Omuro, André M; Loli, José O C

2003-01-01

We describe the case of a boy with steroid-sensitive nephrotic syndrome coexisting with type-1 diabetes mellitus. Nephrotic syndrome was diagnosed in a boy (age 3 years and 11 months) with generalized edema. Marked weight loss (23 to 16 kg), polyuria, polydipsia and weakness were observed after three weeks of treatment with prednisone 2 mg/kg/day. Diabetic ketoacidosis was confirmed by laboratory tests: hyperglycemia (glucose 657 mg/dl), glycosuria without proteinuria, acidosis and ketonuria. Therapy with insulin and prednisone was started. He was then maintained on a daily dose of NPH insulin. At age 4 years and 1 month a new episode of ketoacidosis without proteinuria occurred in association with a viral infection of the upper airways. At age 4 years and 4 months nephrotic syndrome relapsed, but the child responded well to steroid therapy. There was another relapse three months later, when prednisone treatment was interrupted. This led to the introduction of cyclophosphamide, with good results. Since then, the patient (now 5 years and 6 months old) has been taking insulin daily and nephrotic syndrome has not relapsed. Plasma levels of C3 and C4 and renal function are normal. Hematuria is occasionally present. Anti-GAD antibodies (glutamic decarboxilase) are normal and anti-islet cell antibodies are positive. HLA antigens: A2; B44; B52; DR4; DR8; DR53. The simultaneous occurrence of steroid-sensitive nephrotic syndrome and type-1 diabetes mellitus is rare.

Near-infrared sensitization in dye-sensitized solar cells.

PubMed

Park, Jinhyung; Viscardi, Guido; Barolo, Claudia; Barbero, Nadia

2013-01-01

Dye-sensitized solar cells (DSCs) are a low cost and colorful promising alternative to standard silicon photovoltaic cells. Though many of the highest efficiencies have been associated with sensitizers absorbing only in the visible portion of the solar radiation, there is a growing interest for NIR sensitization. This paper reviews the efforts made so far to find sensitizers able to absorb efficiently in the far-red NIR region of solar light. Panchromatic sensitizers as well as dyes absorbing mainly in the 650-920 nm region have been considered.

Risk factors of periodontal disease in maintenance hemodialysis patients

PubMed Central

Hou, Yue; Wang, Xin; Zhang, Cong-Xiao; Wei, Yu-Dan; Jiang, Li-Li; Zhu, Xiao-Yu; Du, Yu-Jun

2017-01-01

Abstract To explore the characteristics and relevant risk factors of periodontal disease (PD) among hemodialysis patients. Uremic patients on maintenance hemodialysis from November 2015 to March 2016 were retrospectively reviewed. Patients were divided into a PD group and a non-PD group. Demographic and laboratory data were collected and analyzed. In all, 136 uremic patients (79 males and 57 females, aged 50.8 ± 15.3 years) on maintenance hemodialysis were included in this study. The incidence of PD increased with age. Hemodialysis patients most likely developed PD if they were male, smokers, or diabetic (P = .009, <.001, and <.001, respectively). Patients brushing their teeth twice daily had significantly less chance of developing PD as compared with those only brushing once daily (P < .001). Hemodialysis patients in the PD group had significantly higher levels of total cholesterol, high-sensitivity C-reactive protein, fasting blood glucose, and peripheral white blood cell counts, compared with the non-PD group (all P < .001). Logistic regression analysis revealed that diabetes, total cholesterol, high-sensitivity C-reactive protein, and peripheral white blood cell count were independent risk factors for developing PD, whereas teeth brushing twice daily and serum calcium were favorable factors for maintenance hemodialysis patients against PD. Identification of risk factors provides a theoretical basis for prevention and improvement of PD among maintenance hemodialysis patients. PMID:28858105

Concanavalin A-mediated polyclonal helper assay of normal thymocytes and its use for the analysis of ontogeny.

PubMed

Kina, T; Nishikawa, S; Amagai, T; Katsura, Y

1987-01-01

A concanavalin A (Con A)-mediated polyclonal helper assay system was established by using the thymus cells or splenic T cells as a source of helper T cells. When splenic B cells were cocultured with thymus cells or splenic Lyt-2- T cells in the presence of an optimal dose of Con A, B Cells were polyclonally activated and differentiated into immunoglobulin-secreting cells. This Con A-mediated helper activity was completely inhibited by the addition of alpha-methyl-D-mannoside and could not be substituted by culture supernatant of Con A-stimulated thymocytes or splenic T cells. Almost all the activity of the thymus cells was carried by peanut agglutinin low binding population. Genetic restriction between T and B cells was not observed in this helper function. In ontogeny, Con A-mediated helper activity in the thymus was first detected at a few days after birth and reached the adult level at about 1 week of age. The polyclonal helper assay system developed in the present study provides a sensitive system to analyse the helper function of thymus cells and also to delineate the early phase of the differentiation of helper T cell population.

Method for characterizing the upset response of CMOS circuits using alpha-particle sensitive test circuits

NASA Technical Reports Server (NTRS)

Buehler, Martin G. (Inventor); Nixon, Robert H. (Inventor); Soli, George A. (Inventor); Blaes, Brent R. (Inventor)

1995-01-01

A method for predicting the SEU susceptibility of a standard-cell D-latch using an alpha-particle sensitive SRAM, SPICE critical charge simulation results, and alpha-particle interaction physics. A technique utilizing test structures to quickly and inexpensively characterize the SEU sensitivity of standard cell latches intended for use in a space environment. This bench-level approach utilizes alpha particles to induce upsets in a low LET sensitive 4-k bit test SRAM. This SRAM consists of cells that employ an offset voltage to adjust their upset sensitivity and an enlarged sensitive drain junction to enhance the cell's upset rate.

Metal-free and Oxygen-free Graphene as Oxygen Reduction Catalysts for Highly Efficient Fuel Cells

DTIC Science & Technology

2013-06-30

electrocatalysts for ORR in fuel cells and other applications, including dye-sensitized solar cells (DSSCs). Introduction Instead of burning...fuel cells and other applications, including dye-sensitized solar cells (DSSCs). 15. SUBJECT TERMS nano materials, nano science and technology...dye sensitized solar cells (DSSCs) have attracted much attention since Oregan and Grätzel’s seminal report in 1991. A typical DSSC device consists

Mediterranean Diet and Phase Angle in a Sample of Adult Population: Results of a Pilot Study

PubMed Central

Barrea, Luigi; Muscogiuri, Giovanna; Macchia, Paolo Emidio; Di Somma, Carolina; Falco, Andrea; Savanelli, Maria Cristina; Colao, Annamaria; Savastano, Silvia

2017-01-01

The Mediterranean diet is a healthy dietary pattern known to actively modulate the cell membrane properties. Phase angle (PhA) is a direct measure by Bioelectrical Impedance Analysis (BIA) used as marker of cell membrane integrity. Both food behaviour and PhA are influenced by age, sex and body weight. The aim of this study was to cross-sectionally evaluate the association between the adherence to Mediterranean diet and PhA in 1013 healthy adult patients stratified according to sex, age, and body mass index (BMI). The adherence to the Mediterranean diet was evaluated using the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. PhA was calculated by BIA phase-sensitive system (50 kHz BIA 101 RJL, Akern Bioresearch, Florence, Italy Akern). In both sexes, at ROC analysis a PREDIMED score ≥ 6 predicted a PhA beyond the median value. At the multivariate analysis, among PREDIMED score, age, and BMI, the PREDIMED score was the major determinant of PhA, explaining 44.5% and 47.3% of PhA variability, in males and females respectively (p < 0.001). A novel association was reported between the adherence to the Mediterranean diet and PhA, independently of sex, age, and body weight. This association uncovered a new potential benefit of the Mediterranean diet on health outcomes, as in both sexes higher adherence to the Mediterranean diet was associated to larger PhAs, as expression of cell membrane integrity. PMID:28218645

Mediterranean Diet and Phase Angle in a Sample of Adult Population: Results of a Pilot Study.

PubMed

Barrea, Luigi; Muscogiuri, Giovanna; Macchia, Paolo Emidio; Di Somma, Carolina; Falco, Andrea; Savanelli, Maria Cristina; Colao, Annamaria; Savastano, Silvia

2017-02-17

The Mediterranean diet is a healthy dietary pattern known to actively modulate the cell membrane properties. Phase angle (PhA) is a direct measure by Bioelectrical Impedance Analysis (BIA) used as marker of cell membrane integrity. Both food behaviour and PhA are influenced by age, sex and body weight. The aim of this study was to cross-sectionally evaluate the association between the adherence to Mediterranean diet and PhA in 1013 healthy adult patients stratified according to sex, age, and body mass index (BMI). The adherence to the Mediterranean diet was evaluated using the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. PhA was calculated by BIA phase-sensitive system (50 kHz BIA 101 RJL, Akern Bioresearch, Florence, Italy Akern). In both sexes, at ROC analysis a PREDIMED score ≥ 6 predicted a PhA beyond the median value. At the multivariate analysis, among PREDIMED score, age, and BMI, the PREDIMED score was the major determinant of PhA, explaining 44.5% and 47.3% of PhA variability, in males and females respectively ( p < 0.001). A novel association was reported between the adherence to the Mediterranean diet and PhA, independently of sex, age, and body weight. This association uncovered a new potential benefit of the Mediterranean diet on health outcomes, as in both sexes higher adherence to the Mediterranean diet was associated to larger PhAs, as expression of cell membrane integrity.

Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration

PubMed Central

Wertheimer, Tobias; Velardi, Enrico; Tsai, Jennifer; Cooper, Kirsten; Xiao, Shiyun; Kloss, Christopher C.; Ottmüller, Katja J.; Mokhtari, Zeinab; Brede, Christian; deRoos, Paul; Kinsella, Sinéad; Palikuqi, Brisa; Ginsberg, Michael; Young, Lauren F.; Kreines, Fabiana; Lieberman, Sophia R.; Lazrak, Amina; Guo, Peipei; Malard, Florent; Smith, Odette M.; Shono, Yusuke; Jenq, Robert R.; Hanash, Alan M.; Nolan, Daniel J.; Butler, Jason M.; Beilhack, Andreas; Manley, Nancy R.; Rafii, Shahin; Dudakov, Jarrod A; van den Brink, Marcel RM

2018-01-01

The thymus is extremely sensitive to damage but also has a remarkable ability to repair itself. However, the mechanisms underlying this endogenous regeneration remain poorly understood and this capacity diminishes considerably with age. Here we show that thymic endothelial cells (ECs) comprise a critical pathway of regeneration, via their production of BMP4. ECs increased their production of BMP4 after thymic damage, and abrogating BMP4 signalling or production by either pharmacologic or genetic inhibition impaired thymic repair. EC-derived BMP4 acted on thymic epithelial cells (TECs) to increase their expression of Foxn1, a key transcription factor involved in TEC development, maintenance and regeneration; and its downstream targets such as Dll4, itself a key mediator of thymocyte development and regeneration. These studies demonstrate the importance of the BMP4 pathway in endogenous tissue regeneration and offer a potential clinical approach to enhance T cell immunity. PMID:29330161

Impact of variations in triage cytology interpretation on human papillomavirus-based cervical screening and implications for screening algorithms.

PubMed

Ronco, Guglielmo; Zappa, Marco; Franceschi, Silvia; Tunesi, Sara; Caprioglio, Adele; Confortini, Massimo; Del Mistro, Annarosa; Carozzi, Francesca; Segnan, Nereo; Zorzi, Manuel; Giorgi-Rossi, Paolo

2016-11-01

Women positive to human papillomavirus (HPV+) testing at cervical screening need triage, typically cytology and immediate colposcopy in case of atypical squamous cells of undetermined significance (ASCUS) or worse (ASCUS+) or, in cytology-normal HPV+ women, HPV test repeat after 1 year and colposcopy referral if still HPV+. Our hypothesis was that substantial variations in triage positivity and sensitivity may produce little variation in overall referral to colposcopy and on sensitivity of the entire screening process. Centre- and age-aggregated data from 72,869 women aged 35-64 years were derived from 10 organised screening programmes which have piloted HPV screening in Italy since 2012. Overall colposcopy referral was evaluated as a function of immediate colposcopy referral and overall CIN2+ detection as a function of the proportion of all CIN2+ detected by immediate referral (a proxy of cytology's sensitivity). We fitted additive regression models, adjusted for centre, age, compliance to HPV retesting and to colposcopy, by generalised estimation equations. The proportion of HPV+ women directly referred to colposcopy varied across programmes (20-57%; average 37%) and so did CIN2+ detection (49-94%; average 77%). Overall, 63% (range 41-75%) of HPV+ were referred to colposcopy either immediately or at HPV repeat. An absolute 10% increase in immediate colposcopy referral resulted in 4.2% (95% CI: 3.3-5.1%) increase in overall referral. An absolute 10% increase in cytology's sensitivity resulted in a 1.1% (95% CI: 0.1-2.0%) increase in overall CIN2+ detection. Repeat HPV testing limits the effect of subjectivity of cytology interpretation on overall referral and sensitivity. These will change only slightly when replacing cytology with another test if the interval to HPV repeat remains unchanged. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Studies of the antibody nature of the rheumatoid factor

PubMed Central

Aho, K.; Harboe, M.; Leikola, J.

1964-01-01

The reaction of the rheumatoid factor (RF) with 7S γ-globulin antibodies of nine persons immunized with sheep erythrocytes was studied. All of a panel of rheumatoid sera with high Waaler-Rose titres agglutinated sheep cells sensitized with the human anti-sheep cell antibodies and O Rh positive cells sensitized with the `diagnostic' anti-CD serum Ripley. The RF measurable with these systems could be absorbed to diphtheria toxoid—human antitoxin precipitate, whereas the absorption with egg albumin—rabbit anti-egg albumin precipitate did not result in any appreciable titre reduction. However, the eluate from the rabbit precipitate was highly active in these systems, whereas Rh positive cells sensitized with anti-Rh sera suitable for Gm(a) typing were not regularly agglutinated. A markedly greater concentration of native than of heat-aggregated γ-globulin was needed for inhibition of the agglutination by the RF of cells heavily sensitized with the human anti-sheep cell antibodies. No appreciable difference in this respect was seen when using lightly sensitized cells. Only the heavily sensitized cells fixed complement. The `natural' 7S γ-globulin antibodies against sheep cells were neither suited for demonstration of RF nor did they fix complement. Sheep cells coated with 7S γ-globulin antibodies of a Gm(a+) person were agglutinated by a non-rheumatoid anti-Gm(a) serum, and this system was well suited for Gm(a) typing, whereas cells coated with antibodies of a Gm(a-) person were not agglutinated. Rheumatoid anti-Gm(a) sera agglutinated cells sensitized with antibodies of both Gm(a+) and Gm(a-) persons. Using cells coated with Gm(a+) antibodies, some distinction between Gm(a+) and Gm(a-) sera could be obtained under carefully controlled conditions. The use of a Gm(a-) coat resulted in a slight difference in the inhibiting capacity, which had no relation to the serum's Gm(a) type. The results suggest that the reaction of the RF with sheep cells heavily sensitized with human anti-sheep cell antibodies is essentially an interaction of the RF with immune aggregated γ-globulin, whereas when using lightly sensitized cells the individual γ-globulin molecules play a prominent role. PMID:14193154

Journal Club: Comparison of assessment of preoperative pulmonary vasculature in patients with non-small cell lung cancer by non-contrast- and 4D contrast-enhanced 3-T MR angiography and contrast-enhanced 64-MDCT.

PubMed

Ohno, Yoshiharu; Nishio, Mizuho; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Seki, Shinichiro; Sugimura, Kazuro

2014-03-01

The purpose of this article is to prospectively and directly compare the capabilities of non-contrast-enhanced MR angiography (MRA), 4D contrast-enhanced MRA, and contrast-enhanced MDCT for assessing pulmonary vasculature in patients with non-small cell lung cancer (NSCLC) before surgical treatment. A total of 77 consecutive patients (41 men and 36 women; mean age, 71 years) with pathologically proven and clinically assessed stage I NSCLC underwent thin-section contrast-enhanced MDCT, non-contrast-enhanced and contrast-enhanced MRA, and surgical treatment. The capability for anomaly assessment of the three methods was independently evaluated by two reviewers using a 5-point visual scoring system, and final assessment for each patient was made by consensus of the two readers. Interobserver agreement for pulmonary arterial and venous assessment was evaluated with the kappa statistic. Then, sensitivity, specificity, and accuracy for the detection of anomalies were directly compared among the three methods by use of the McNemar test. Interobserver agreement for pulmonary artery and vein assessment was substantial or almost perfect (κ=0.72-0.86). For pulmonary arterial and venous variation assessment, there were no significant differences in sensitivity, specificity, and accuracy among non-contrast-enhanced MRA (pulmonary arteries: sensitivity, 77.1%; specificity, 97.4%; accuracy, 87.7%; pulmonary veins: sensitivity, 50%; specificity, 98.5%; accuracy, 93.2%), 4D contrast-enhanced MRA (pulmonary arteries: sensitivity, 77.1%; specificity, 97.4%; accuracy, 87.7%; pulmonary veins: sensitivity, 62.5%; specificity, 100.0%; accuracy, 95.9%), and thin-section contrast-enhanced MDCT (pulmonary arteries: sensitivity, 91.4%; specificity, 89.5%; accuracy, 90.4%; pulmonary veins: sensitivity, 50%; specificity, 100.0%; accuracy, 95.9%) (p>0.05). Pulmonary vascular assessment of patients with NSCLC before surgical resection by non-contrast-enhanced MRA can be considered equivalent to that by 4D contrast-enhanced MRA and contrast-enhanced MDCT.

Responses of glomus cells to hypoxia and acidosis are uncoupled, reciprocal and linked to ASIC3 expression: selectivity of chemosensory transduction

PubMed Central

Lu, Yongjun; Whiteis, Carol A; Sluka, Kathleen A; Chapleau, Mark W; Abboud, François M

2013-01-01

Carotid body glomus cells are the primary sites of chemotransduction of hypoxaemia and acidosis in peripheral arterial chemoreceptors. They exhibit pronounced morphological heterogeneity. A quantitative assessment of their functional capacity to differentiate between these two major chemical signals has remained undefined. We tested the hypothesis that there is a differential sensory transduction of hypoxia and acidosis at the level of glomus cells. We measured cytoplasmic Ca2+ concentration in individual glomus cells, isolated in clusters from rat carotid bodies, in response to hypoxia ( mmHg) and to acidosis at pH 6.8. More than two-thirds (68%) were sensitive to both hypoxia and acidosis, 19% were exclusively sensitive to hypoxia and 13% exclusively sensitive to acidosis. Those sensitive to both revealed significant preferential sensitivity to either hypoxia or to acidosis. This uncoupling and reciprocity was recapitulated in a mouse model by altering the expression of the acid-sensing ion channel 3 (ASIC3) which we had identified earlier in glomus cells. Increased expression of ASIC3 in transgenic mice increased pH sensitivity while reducing cyanide sensitivity. Conversely, deletion of ASIC3 in the knockout mouse reduced pH sensitivity while the relative sensitivity to cyanide or to hypoxia was increased. In this work, we quantify functional differences among glomus cells and show reciprocal sensitivity to acidosis and hypoxia in most glomus cells. We speculate that this selective chemotransduction of glomus cells by either stimulus may result in the activation of different afferents that are preferentially more sensitive to either hypoxia or acidosis, and thus may evoke different and more specific autonomic adjustments to either stimulus. PMID:23165770

Effects of quench rate and natural ageing on the age hardening behaviour of aluminium alloy AA6060

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

Strobel, Katharina, E-mail: katharina.strobel@aol.com; Lay, Matthew D.H., E-mail: mlay@fbrice.com; Easton, Mark A., E-mail: mark.easton@rmit.edu.au

Quench sensitivity in Al–Mg–Si alloys has been largely attributed to the solute loss at the heterogeneous nucleation sites, primarily dispersoids, during slow cooling after extrusion. As such, the number density of dispersoids, the solute type and concentration are considered to be the key variables for the quench sensitivity. In this study, quench sensitivity and the influence of natural ageing in a lean Al–Mg–Si alloy, AA6060, which contains few dispersoids, have been investigated by hardness measurement, thermal analysis, transmission electron microscopy (TEM) and positron annihilation lifetime spectroscopy (PALS). It is shown that the quench sensitivity in this alloy is associated withmore » the degree of supersaturation of vacancies after cooling. Due to vacancy annihilation and clustering during natural ageing, the quench sensitivity is more pronounced after a short natural ageing time (30 min) compared to a longer natural ageing time (24 h). Therefore, prolonged natural ageing not only leads to an increase in hardness, but can also have a positive effect on the quench sensitivity of lean Al–Mg–Si alloys. - Highlights: • Significant quench sensitivity observed in AA6060 alloy after 30 min natural ageing • Prolonged natural ageing increased hardness and reduced QS. • Low dispersoid density leads to insignificant QS from non-hardening precipitates. • Vacancy supersaturation identified as a contributor to QS.« less

Glutamic acid decarboxylase autoantibody-positivity post-partum is associated with impaired β-cell function in women with gestational diabetes mellitus.

PubMed

Lundberg, T P; Højlund, K; Snogdal, L S; Jensen, D M

2015-02-01

To investigate whether the presence of glutamic acid decarboxylase (GAD) autoantibodies post-partum in women with prior gestational diabetes mellitus was associated with changes in metabolic characteristics, including β-cell function and insulin sensitivity. During 1997-2010, 407 women with gestational diabetes mellitus were offered a 3-month post-partum follow-up including anthropometrics, serum lipid profile, HbA1c and GAD autoantibodies, as well as a 2-h oral glucose tolerance test (OGTT) with blood glucose, serum insulin and C-peptide at 0, 30 and 120 min. Indices of insulin sensitivity and insulin secretion were estimated to assess insulin secretion adjusted for insulin sensitivity, disposition index (DI). Twenty-two (5.4%) women were positive for GAD autoantibodies (GAD+ve) and the remainder (94.6%) were negative for GAD autoantibodies (GAD-ve). The two groups had similar age and prevalence of diabetes mellitus. Women who were GAD+ve had significantly higher 2-h OGTT glucose concentrations during their index-pregnancy (10.5 vs. 9.8 mmol/l, P = 0.001), higher fasting glucose (5.2 vs. 5.0 mmol/l, P = 0.02) and higher 2-h glucose (7.8 vs. 7.1 mmol/l, P = 0.05) post-partum. Fasting levels of C-peptide and insulin were lower in GAD+ve women compared with GAD-ve women (520 vs. 761 pmol/l, P = 0.02 and 33 vs. 53 pmol/l, P = 0.05) Indices of insulin sensitivity were similar in GAD+ve and GAD-ve women, whereas all estimates of DI were significantly reduced in GAD+ve women. GAD+ve women had higher glucose levels and impaired insulin secretion adjusted for insulin sensitivity (DI) compared with GAD-ve women. The combination of OGTT and GAD autoantibodies post-partum identify women with impaired β-cell function. These women should be followed with special focus on development of Type 1 diabetes. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.

Chronic Opioid Therapy and Central Sensitization in Sickle Cell Disease.

PubMed

Carroll, C Patrick; Lanzkron, Sophie; Haywood, Carlton; Kiley, Kasey; Pejsa, Megan; Moscou-Jackson, Gyasi; Haythornthwaite, Jennifer A; Campbell, Claudia M

2016-07-01

Chronic opioid therapy (COT) for chronic non-cancer pain is frequently debated, and its effectiveness is unproven in sickle cell disease (SCD). The authors conducted a descriptive study among 83 adult SCD patients and compared the severity of disease and pain symptoms among those who were prescribed COT (n=29) with those who were not using COT. All patients completed baseline laboratory pain assessment and questionnaires between January 2010 and June 2014. Thereafter, participants recorded daily pain, crises, function, and healthcare utilization for 90 days using electronic diaries. Analyses were conducted shortly after the final diary data collection period. Patients on COT did not differ on age, sex, or measures of disease severity. However, patients on COT exhibited greater levels of clinical pain (particularly non-crisis); central sensitization; and depression and increased diary measures of pain severity, function, and healthcare utilization on crisis and non-crisis diary days, as well as a greater proportion of days in crisis. Including depressive symptoms in multivariate models did not change the associations between COT and pain, interference, central sensitization, or utilization. Additionally, participants not on COT displayed the expected positive relationship between central sensitization and clinical pain, whereas those on COT demonstrated no such relationship, despite having both higher central sensitization and higher clinical pain. Overall, the results point out a high symptom burden in SCD patients on COT, including those on high-dose COT, and suggest that nociceptive processing in SCD patients on COT differs from those who are not. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

MHC-I modulation due to changes in tumor cell metabolism regulates tumor sensitivity to CTL and NK cells

PubMed Central

Catalán, Elena; Charni, Seyma; Jaime, Paula; Aguiló, Juan Ignacio; Enríquez, José Antonio; Naval, Javier; Pardo, Julián; Villalba, Martín; Anel, Alberto

2015-01-01

Tumor cells have a tendency to use glucose fermentation to obtain energy instead of mitochondrial oxidative phosphorylation (OXPHOS). We demonstrated that this phenotype correlated with loss of ERK5 expression and with reduced MHC class I expression. Consequently, tumor cells could evade cytotoxic T lymphocyte (CTL)-mediated immune surveillance, but also increase their sensitivity to natural killer (NK) cells. These outcomes were evaluated using two cellular models: leukemic EL4 cells and L929 transformed fibroblasts and their derived ρ° cell lines, which lack mitochondrial DNA. We have also used a L929 cell sub-line that spontaneously lost matrix attachment (L929dt), reminiscent of metastasis generation, that also downregulated MHC-I and ERK5 expression. MHC-I expression is lower in ρ° cells than in the parental cell lines, but they were equally sensitive to CTL. On the contrary, ρ° cells were more sensitive to activated NK cells than parental cells. On the other hand, L929dt cells were resistant to CTL and NK cells, showed reduced viability when forced to perform OXPHOS, and surviving cells increased MHC-I expression and became sensitive to CTL. The present results suggest that when the reduction in MHC-I levels in tumor cells due to glycolytic metabolism is partial, the increase in sensitivity to NK cells seems to predominate. However, when tumor cells completely lose MHC-I expression, the combination of treatments that increase OXPHOS with CTL-mediated immunotherapy could be a promising therapeutic approach. PMID:25949869

MHC-I modulation due to changes in tumor cell metabolism regulates tumor sensitivity to CTL and NK cells.

PubMed

Catalán, Elena; Charni, Seyma; Jaime, Paula; Aguiló, Juan Ignacio; Enríquez, José Antonio; Naval, Javier; Pardo, Julián; Villalba, Martín; Anel, Alberto

2015-01-01

Tumor cells have a tendency to use glucose fermentation to obtain energy instead of mitochondrial oxidative phosphorylation (OXPHOS). We demonstrated that this phenotype correlated with loss of ERK5 expression and with reduced MHC class I expression. Consequently, tumor cells could evade cytotoxic T lymphocyte (CTL)-mediated immune surveillance, but also increase their sensitivity to natural killer (NK) cells. These outcomes were evaluated using two cellular models: leukemic EL4 cells and L929 transformed fibroblasts and their derived ρ° cell lines, which lack mitochondrial DNA. We have also used a L929 cell sub-line that spontaneously lost matrix attachment (L929dt), reminiscent of metastasis generation, that also downregulated MHC-I and ERK5 expression. MHC-I expression is lower in ρ° cells than in the parental cell lines, but they were equally sensitive to CTL. On the contrary, ρ° cells were more sensitive to activated NK cells than parental cells. On the other hand, L929dt cells were resistant to CTL and NK cells, showed reduced viability when forced to perform OXPHOS, and surviving cells increased MHC-I expression and became sensitive to CTL. The present results suggest that when the reduction in MHC-I levels in tumor cells due to glycolytic metabolism is partial, the increase in sensitivity to NK cells seems to predominate. However, when tumor cells completely lose MHC-I expression, the combination of treatments that increase OXPHOS with CTL-mediated immunotherapy could be a promising therapeutic approach.

Hybrid generative-discriminative approach to age-invariant face recognition

NASA Astrophysics Data System (ADS)

Sajid, Muhammad; Shafique, Tamoor

2018-03-01

Age-invariant face recognition is still a challenging research problem due to the complex aging process involving types of facial tissues, skin, fat, muscles, and bones. Most of the related studies that have addressed the aging problem are focused on generative representation (aging simulation) or discriminative representation (feature-based approaches). Designing an appropriate hybrid approach taking into account both the generative and discriminative representations for age-invariant face recognition remains an open problem. We perform a hybrid matching to achieve robustness to aging variations. This approach automatically segments the eyes, nose-bridge, and mouth regions, which are relatively less sensitive to aging variations compared with the rest of the facial regions that are age-sensitive. The aging variations of age-sensitive facial parts are compensated using a demographic-aware generative model based on a bridged denoising autoencoder. The age-insensitive facial parts are represented by pixel average vector-based local binary patterns. Deep convolutional neural networks are used to extract relative features of age-sensitive and age-insensitive facial parts. Finally, the feature vectors of age-sensitive and age-insensitive facial parts are fused to achieve the recognition results. Extensive experimental results on morphological face database II (MORPH II), face and gesture recognition network (FG-NET), and Verification Subset of cross-age celebrity dataset (CACD-VS) demonstrate the effectiveness of the proposed method for age-invariant face recognition well.

Insensitive parenting may accelerate the development of the amygdala-medial prefrontal cortex circuit.

PubMed

Thijssen, Sandra; Muetzel, Ryan L; Bakermans-Kranenburg, Marian J; Jaddoe, Vincent W V; Tiemeier, Henning; Verhulst, Frank C; White, Tonya; Van Ijzendoorn, Marinus H

2017-05-01

This study examined whether the association between age and amygdala-medial prefrontal cortex (mPFC) connectivity in typically developing 6- to 10-year-old children is correlated with parental care. Resting-state functional magnetic resonance imaging scans were acquired from 124 children of the Generation R Study who at 4 years old had been observed interacting with their parents to assess maternal and paternal sensitivity. Amygdala functional connectivity was assessed using a general linear model with the amygdalae time series as explanatory variables. Higher level analyses assessing Sensitivity × Age as well as exploratory Sensitivity × Age × Gender interaction effects were performed restricted to voxels in the mPFC. We found significant Sensitivity × Age interaction effects on amygdala-mPFC connectivity. Age was related to stronger amygdala-mPFC connectivity in children with a lower combined parental sensitivity score (b = 0.11, p = .004, b = 0.06, p = .06, right and left amygdala, respectively), but not in children with a higher parental sensitivity score, (b = -0.07, p = .12, b = -0.06, p = .12, right and left amygdala, respectively). A similar effect was found for maternal sensitivity, with stronger amygdala-mPFC connectivity in children with less sensitive mothers. Exploratory (parental, maternal, paternal) Sensitivity × Age × Gender interaction analyses suggested that this effect was especially pronounced in girls. Amygdala-mPFC resting-state functional connectivity has been shown to increase from age 10.5 years onward, implying that the positive association between age and amygdala-mPFC connectivity in 6- to 10-year-old children of less sensitive parents represents accelerated development of the amygdala-mPFC circuit.

Characterization of screen-printed dye-sensitized nanocrystalline TiO2 solar cells

NASA Astrophysics Data System (ADS)

Gupta, Tapan K.; Cirignano, Leonard J.; Shah, Kanai S.; Moy, Larry P.; Kelly, David J.; Squillante, Michael R.; Entine, Gerald; Smestad, Greg P.

1999-10-01

Titanium dioxide (TiO2) films have been deposited on SnO2 coated glass substrates by screen-printing. Film morphology and structure have been characterized by scanning electron microscopy, x-ray diffraction and BET analysis. Dye-sensitized TiO2 photoelectrochemical cells have been assembled and characterized. Cells sensitized with anthocyanin and a ruthenium complex have been investigated. A 0.77 cm2 ruthenium dye sensitized cell with 6.1% power conversion efficiency under Air Mass (AM1.5) conditions was obtained. Results obtained with a pure anthocyanin dye and dye extracted from blackberries were compared. Finally, a natural gel was found to improve the stability of anthocyanin sensitized cells.

Asymptomatic bacteriuria of pregnancy in Ibadan, Nigeria: a re-assessment.

PubMed

Akinloye, O; Ogbolu, D O; Akinloye, O M; Terry Alli, O A

2006-01-01

Asymptomatic bacteriuria in pregnancy is the major risk factor for developing symptomatic urinary tract infection during pregnancy. In the present study, 300 pregnant women are screened for significant asymptomatic bacteriuria in order to provide an insight into the prevalence in developing countries, reassessment of some predisposing factors and aetiological agents and their susceptibility tests. The mean age of the patients in the study is 26.8 years (SD: 5.8 years, range: 16-40 years). Using 10(3) organisms/mL as a significant level of bacteriuria, the prevalence was found to be 21.0%. One hundred and fifty-eight samples had no pus cells, with 25 showing significant bacteriuria, 116 samples contained 1-4 pus cells/high power field (hpf) with 25 showing significant bacteriuria, while 26 samples had > or = 5 pus cells/hpf with 13 showing significant bacteriuria. There was no particular trend associated with age and rate of infection. However, there was a decline in the rate of infection in the 26-30 age group, with a sharp increase as age increased. There was high incidence of bacteriuria during the third trimester of pregnancy (21.9%) compared with that in the first trimester (7.7%), while the level in the second trimester was 22.5%. Multiparity is associated with increased bacteriuria in pregnancy. Thirty-one (49.2%) isolates grew Gram-negative bacilli; 27 (42.9%) grew Gram-positive cocci and the remainder (7.9%) grew yeast-like cells. Staphylococcus aureus was the most frequent pathogen (41.3%), followed by Klebsiella species (33.3%) and Escherichia coli (11.1%). Bacterial isolates from this study were most sensitive to ceftazidime, followed by ceftriazone, and least susceptible to co-trimoxazole.

Ozone and allergen exposure during postnatal development alters the frequency and airway distribution of CD25+ cells in infant rhesus monkeys

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

Miller, Lisa A.; California National Primate Research Center, University of California, Davis, CA 95616; Gerriets, Joan E.

2009-04-01

The epidemiologic link between air pollutant exposure and asthma has been supported by experimental findings, but the mechanisms are not understood. In this study, we evaluated the impact of combined ozone and house dust mite (HDM) exposure on the immunophenotype of peripheral blood and airway lymphocytes from rhesus macaque monkeys during the postnatal period of development. Starting at 30 days of age, monkeys were exposed to 11 cycles of filtered air, ozone, HDM aerosol, or ozone + HDM aerosol. Each cycle consisted of ozone delivered at 0.5 ppm for 5 days (8 h/day), followed by 9 days of filtered air;more » animals received HDM aerosol during the last 3 days of each ozone exposure period. Between 2-3 months of age, animals co-exposed to ozone + HDM exhibited a decline in total circulating leukocyte numbers and increased total circulating lymphocyte frequency. At 3 months of age, blood CD4+/CD25+ lymphocytes were increased with ozone + HDM. At 6 months of age, CD4+/CD25+ and CD8+/CD25+ lymphocyte populations increased in both blood and lavage of ozone + HDM animals. Overall volume of CD25+ cells within airway mucosa increased with HDM exposure. Ozone did not have an additive effect on volume of mucosal CD25+ cells in HDM-exposed animals, but did alter the anatomical distribution of this cell type throughout the proximal and distal airways. We conclude that a window of postnatal development is sensitive to air pollutant and allergen exposure, resulting in immunomodulation of peripheral blood and airway lymphocyte frequency and trafficking.« less

Live-Cell Imaging of Phagosome Motility in Primary Mouse RPE Cells.

PubMed

Hazim, Roni; Jiang, Mei; Esteve-Rudd, Julian; Diemer, Tanja; Lopes, Vanda S; Williams, David S

2016-01-01

The retinal pigment epithelium (RPE) is a post-mitotic epithelial monolayer situated between the light-sensitive photoreceptors and the choriocapillaris. Given its vital functions for healthy vision, the RPE is a primary target for insults that result in blinding diseases, including age-related macular degeneration (AMD). One such function is the phagocytosis and digestion of shed photoreceptor outer segments. In the present study, we examined the process of trafficking of outer segment disk membranes in live cultures of primary mouse RPE, using high speed spinning disk confocal microscopy. This approach has enabled us to track phagosomes, and determine parameters of their motility, which are important for their efficient degradation.

Cell Electrosensitization Exists Only in Certain Electroporation Buffers.

PubMed

Dermol, Janja; Pakhomova, Olga N; Pakhomov, Andrei G; Miklavčič, Damijan

2016-01-01

Electroporation-induced cell sensitization was described as the occurrence of a delayed hypersensitivity to electric pulses caused by pretreating cells with electric pulses. It was achieved by increasing the duration of the electroporation treatment at the same cumulative energy input. It could be exploited in electroporation-based treatments such as electrochemotherapy and tissue ablation with irreversible electroporation. The mechanisms responsible for cell sensitization, however, have not yet been identified. We investigated cell sensitization dynamics in five different electroporation buffers. We split a pulse train into two trains varying the delay between them and measured the propidium uptake by fluorescence microscopy. By fitting the first-order model to the experimental results, we determined the uptake due to each train (i.e. the first and the second) and the corresponding resealing constant. Cell sensitization was observed in the growth medium but not in other tested buffers. The effect of pulse repetition frequency, cell size change, cytoskeleton disruption and calcium influx do not adequately explain cell sensitization. Based on our results, we can conclude that cell sensitization is a sum of several processes and is buffer dependent. Further research is needed to determine its generality and to identify underlying mechanisms.

Cell Electrosensitization Exists Only in Certain Electroporation Buffers

PubMed Central

Dermol, Janja; Pakhomova, Olga N.; Pakhomov, Andrei G.; Miklavčič, Damijan

2016-01-01

Electroporation-induced cell sensitization was described as the occurrence of a delayed hypersensitivity to electric pulses caused by pretreating cells with electric pulses. It was achieved by increasing the duration of the electroporation treatment at the same cumulative energy input. It could be exploited in electroporation-based treatments such as electrochemotherapy and tissue ablation with irreversible electroporation. The mechanisms responsible for cell sensitization, however, have not yet been identified. We investigated cell sensitization dynamics in five different electroporation buffers. We split a pulse train into two trains varying the delay between them and measured the propidium uptake by fluorescence microscopy. By fitting the first-order model to the experimental results, we determined the uptake due to each train (i.e. the first and the second) and the corresponding resealing constant. Cell sensitization was observed in the growth medium but not in other tested buffers. The effect of pulse repetition frequency, cell size change, cytoskeleton disruption and calcium influx do not adequately explain cell sensitization. Based on our results, we can conclude that cell sensitization is a sum of several processes and is buffer dependent. Further research is needed to determine its generality and to identify underlying mechanisms. PMID:27454174

The cytokine-dependent MUTZ-3 cell line as an in vitro model for the screening of contact sensitizers

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

Azam, Philippe; Peiffer, Jean-Luc; Chamousset, Delphine

2006-04-01

Langerhans cells (LC) are key mediators of contact allergenicity in the skin. However, no in vitro methods exist which are based on the activation process of LC to predict the sensitization potential of chemicals. In this study, we have evaluated the performances of MUTZ-3, a cytokine-dependent human monocytic cell line, in its response to sensitizers. First, we compared undifferentiated MUTZ-3 cells with several standard human cells such as THP-1, KG-1, HL-60, K-562, and U-937 in their response to the strong sensitizer DNCB and the irritant SDS by monitoring the expression levels of HLA-DR, CD54, and CD86 by flow cytometry. Onlymore » MUTZ-3 and THP-1 cells show a strong and specific response to sensitizer, while other cell lines showed very variable responses. Then, we tested MUTZ-3 cells against a wider panel of sensitizers and irritants on a broader spectrum of cell surface markers (HLA-DR, CD40, CD54, CD80, CD86, B7-H1, B7-H2, B7-DC). Of these markers, CD86 proved to be the most reliable since it detected all sensitizers, including benzocaine, a classical false negative in local lymph node assay (LLNA) but not irritants. We confirmed the MUTZ-3 response to DNCB by real-time PCR analysis. Taken together, our data suggest that undifferentiated MUTZ-3 cells may represent a valuable in vitro model for the screening of potential sensitizers.« less

The BCL2 antagonist of cell death pathway influences endometrial cancer cell sensitivity to cisplatin.

PubMed

Chon, Hye Sook; Marchion, Douglas C; Xiong, Yin; Chen, Ning; Bicaku, Elona; Stickles, Xiaomang Ba; Bou Zgheib, Nadim; Judson, Patricia L; Hakam, Ardeshir; Gonzalez-Bosquet, Jesus; Wenham, Robert M; Apte, Sachin M; Lancaster, Johnathan M

2012-01-01

To identify pathways that influence endometrial cancer (EC) cell sensitivity to cisplatin and to characterize the BCL2 antagonist of cell death (BAD) pathway as a therapeutic target to increase cisplatin sensitivity. Eight EC cell lines (Ishikawa, MFE296, RL 95-2, AN3CA, KLE, MFE280, MFE319, HEC-1-A) were subjected to Affymetrix Human U133A GeneChip expression analysis of approximately 22,000 probe sets. In parallel, endometrial cell line sensitivity to cisplatin was quantified by MTS assay, and IC(50) values were calculated. Pearson's correlation test was used to identify genes associated with response to cisplatin. Genes associated with cisplatin responsiveness were subjected to pathway analysis. The BAD pathway was identified and subjected to targeted modulation, and the effect on cisplatin sensitivity was evaluated. Pearson's correlation analysis identified 1443 genes associated with cisplatin resistance (P<0.05), which included representation of the BAD-apoptosis pathway. Small interfering RNA (siRNA) knockdown of BAD pathway protein phosphatase PP2C expression was associated with increased phosphorylated BAD (serine-155) levels and a parallel increase in cisplatin resistance in Ishikawa (P=0.004) and HEC-1-A (P=0.02) cell lines. In contrast, siRNA knockdown of protein kinase A expression increased cisplatin sensitivity in the Ishikawa (P=0.02) cell line. The BAD pathway influences EC cell sensitivity to cisplatin, likely via modulation of the phosphorylation status of the BAD protein. The BAD pathway represents an appealing therapeutic target to increase EC cell sensitivity to cisplatin. Copyright © 2011 Elsevier Inc. All rights reserved.

Clinical implications of proliferation activity in T1 or T2 male gastric cancer patients.

PubMed

Kim, Young-Woo; Eom, Bang Wool; Kook, Myeong-Cherl; Kim, Han-Seong; Kim, Mi-Kyung; Hwang, Hai-Li; Chandra, Vishal; Poojan, Shiv; Song, Yura; Koh, Jae-Soo; Bae, Chang-Dae; Ro, Jungsil; Hong, Kyeong-Man

2015-11-06

Proliferation activity has already been established as a prognostic marker or as a marker for anticancer drug sensitivity. In gastric cancer, however, the prognostic significance of proliferation activity is still being debated. Several studies evaluating proliferation activity using Ki-67 have shown controversial results in terms of the relationship between proliferation activity and overall survival (OS) or drug sensitivity in gastric cancer patients. Because cytoskeleton-associated protein 2 (CKAP2) staining has recently been introduced as a marker of proliferation activity, we analyzed 437 gastric cancer tissues through CKAP2 immunohistochemistry, and we evaluated the chromatin CKAP2-positive cell count (CPCC) for proliferation activity. Although the CPCC did not show any significant correlation with OS in the male, female or total number of cases, it did show a significant correlation in the T1 or T2 male patient subgroup, according to log-rank tests (P=0.001) and univariate analysis (P=0.045). Additionally, multivariate analysis with the Cox proportional hazard regression model showed a significant correlation between the CPCC and OS (P=0.039) for the co-variables of age, gender, T stage, N stage, histology, tumor location, tumor size and adjuvant chemotherapy. In male gastric cancer cell lines, faster-growing cancer cells showed higher sensitivity to cisplatin than slow-growing cells. Thus our study indicates that CPCC-measured proliferation activity demonstrates a significantly worse prognosis in T1 or T2 male gastric cancer patients. The CPCC will help to more precisely classify gastric cancer patients and to select excellent candidates for adjuvant chemotherapy, which in turn will facilitate further clinical chemotherapeutic trials.

Parental Interpersonal Sensitivity and Youth Social Problems: A Mediational Role for Child Emotion Dysregulation

ERIC Educational Resources Information Center

Suveg, Cynthia; Jacob, Marni L.; Payne, Mary

2010-01-01

We examined the relations between parental interpersonal sensitivity and youth social problems and explored the mediational role of child emotion dysregulation. Mothers (N = 42; M age = 39.38) and fathers (N = 41; M age = 39.38) of youth aged 7-12 (N = 42; M age = 9.12) completed measures of their own interpersonal sensitivity and reported on…

Age- and sex-related characteristics of tonic GABA currents in the rat substantia nigra pars reticulata.

PubMed

Chudomel, O; Hasson, H; Bojar, M; Moshé, S L; Galanopoulou, A S

2015-04-01

Previous studies have shown that the pharmacologic effects of GABAergic drugs and the postsynaptic phasic GABAAergic inhibitory responses in the anterior part of the rat substantia nigra pars reticulata (SNRA) are age- and sex-specific. Here, we investigate whether there are age- and sex-related differences in the expression of the δ GABAA receptor (GABAAR) subunit and GABAAR mediated tonic currents. We have used δ-specific immunochemistry and whole cell patch clamp to study GABAAR mediated tonic currents in the SNRA of male and female postnatal day (PN) PN5-9, PN11-16, and PN25-32 rats. We observed age-related decline, but no sex-specific changes, in bicuculline (BIM) sensitive GABAAR tonic current density, which correlated with the decline in δ subunit in the SNRA between PN15 and 30. Furthermore, we show that the GABAAR tonic currents can be modified by muscimol (GABAAR agonist; partial GABACR agonist), THIP (4,5,6,7-tetrahydroisoxazolo (5,4-c)pyridin-3-ol: α4β3δ GABAARs agonist and GABACR antagonist), and zolpidem (α1-subunit selective GABAAR agonist) in age- and sex-dependent manner specific for each drug. We propose that the emergence of the GABAAR-sensitive anticonvulsant effects of the rat SNRA during development may depend upon the developmental decline in tonic GABAergic inhibition of the activity of rat SNRA neurons, although other sex-specific factors are also involved.

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

Smith, Jordan N.; Hinderliter, Paul M.; Timchalk, Charles

Sensitivity to chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to computationally predict disposition of CPF and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, age-dependent body weight was calculated from a generalized Gompertz function, and compartments (liver, brain, fat, blood, diaphragm, rapid, and slow) were scaled based on body weight from polynomial functions on a fractional body weight basis. Bloodmore » flows among compartments were calculated as a constant flow per compartment volume. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Model simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ≥ 0.55 mg/kg of chlorpyrifos (significantly higher than environmental exposure levels), 6 mo old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent oral doses of chlorpyrifos. At lower doses that are more relevant to environmental exposures, the model predicts that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict CPF disposition and biological response over various postnatal life-stages.« less

Utility of the serum C-reactive protein for detection of occult bacterial infection in children.

PubMed

Isaacman, Daniel J; Burke, Bonnie L

2002-09-01

To assess the utility of serum C-reactive protein (CRP) as a screen for occult bacterial infection in children. Febrile children ages 3 to 36 months who visited an urban children's hospital emergency department and received a complete blood cell count and blood culture as part of their evaluation were prospectively enrolled from February 2, 2000, through May 30, 2001. Informed consent was obtained for the withdrawal of an additional 1-mL aliquot of blood for use in CRP evaluation. Logistic regression and receiver operator characteristic (ROC) curves were modeled for each predictor to identify optimal test values, and were compared using likelihood ratio tests. Two hundred fifty-six patients were included in the analysis, with a median age of 15.3 months (range, 3.1-35.2 months) and median temperature at triage 40.0 degrees C (range, 39.0 degrees C-41.3 degrees C). Twenty-nine (11.3%) cases of occult bacterial infection (OBI) were identified, including 17 cases of pneumonia, 9 cases of urinary tract infection, and 3 cases of bacteremia. The median white blood cell count in this data set was 12.9 x 10(3)/ micro L [corrected] (range, 3.6-39.1 x10(3)/ micro L) [corrected], the median absolute neutrophil count (ANC) was 7.12 x 10(3)/L [corrected] (range, 0.56-28.16 x10(3)/L) [corrected], and the median CRP level was 1.7 mg/dL (range, 0.2-43.3 mg/dL). The optimal cut-off point for CRP in this data set (4.4 mg/dL) achieved a sensitivity of 63% and a specificity of 81% for detection of OBI in this population. Comparing models using cut-off values from individual laboratory predictors (ANC, white blood cell count, and CRP) that maximized sensitivity and specificity revealed that a model using an ANC of 10.6 x10(3)/L [corrected] (sensitivity, 69%; specificity, 79%) was the best predictive model. Adding CRP to the model insignificantly increased sensitivity to 79%, while significantly decreasing specificity to 50%. Active monitoring of emergency department blood cultures drawn during the study period from children between 3 and 36 months of age showed an overall bacteremia rate of 1.1% during this period. An ANC cut-off point of 10.6 x10(3)/L [corrected] offers the best predictive model for detection of occult bacterial infection using a single test. The addition of CRP to ANC adds little diagnostic utility. Furthermore, the lowered incidence of occult bacteremia in our population supports a decrease in the use of diagnostic screening in this population.

Enhanced antitumor reactivity of tumor-sensitized T cells by interferon alfa

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

Vander Woude, D.L.; Wagner, P.D.; Shu, S.

Tumor-draining lymph node cells from mice bearing the methylcholanthrene-induced MCA 106 tumors can be sensitized in vitro to acquire antitumor reactivity. We examined the effect of interferon alfa on the function of cells that underwent in vitro sensitization in adoptive immunotherapy. Interferon alfa increased the antitumor reactivity of in vitro sensitized cells in the treatment of MCA 106 pulmonary metastases. This effect was evident in irradiated mice, indicating that a host response to the interferon alfa was not required. Interferon alfa treatment increased class I major histocompatibility complex antigen expression on tumor cells and increased their susceptibility to lysis bymore » in vitro sensitized cells. These results suggest that interferon alfa enhancement of adoptive immunotherapy was mediated by its effect on tumor cells. Interferon alfa may be a useful adjunct to the adoptive immunotherapy of human cancer.« less

Endothelial glucocorticoid receptor promoter methylation according to dexamethasone sensitivity

PubMed Central

Mata-Greenwood, Eugenia; Jackson, P Naomi; Pearce, William J; Zhang, Lubo

2016-01-01

We have previously shown that in vitro sensitivity to dexamethasone (DEX) stimulation in human endothelial cells is positively regulated by the glucocorticoid receptor (NR3C1, GR). The present study determined the role of differential GR transcriptional regulation in glucocorticoid sensitivity. We studied 25 human umbilical vein endothelial cells (HUVECs) that had been previously characterized as DEX-sensitive (n = 15), or resistant (n = 10). Real-time PCR analysis of GR 5′UTR mRNA isoforms showed that all HUVECs expressed isoforms 1B, 1C, 1D, 1F, and 1H, and isoforms 1B and 1C were predominantly expressed. DEX-resistant cells expressed higher basal levels of the 5′UTR mRNA isoforms 1C and 1D, but lower levels of the 5′UTR mRNA isoform 1F than DEX-sensitive cells. DEX treatment significantly decreased GRα and GR-1C mRNA isoform expression in DEX-resistant cells only. Reporter luciferase assays indicated that differential GR mRNA isoform expression was not due to differential promoter usage between DEX-sensitive and DEX-resistant cells. Analysis of promoter methylation, however, showed that DEX-sensitive cells have higher methylation levels of promoter 1D and lower methylation levels of promoter 1F than DEX-resistant cells. Treatment with 5-aza-2-deoxycytidine abolished the differential 5′UTR mRNA isoform expression between DEX-sensitive and DEX-resistant cells. Finally, both GRα overexpression and 5-aza-2-deoxycytidine treatment eliminated the differences between sensitivity groups to DEX-mediated downregulation of endothelial nitric oxide synthase (NOS3), and upregulation of plasminogen activator inhibitor 1 (SERPINE1). In sum, human endothelial GR 5′UTR mRNA expression is regulated by promoter methylation with DEX-sensitive and DEX-resistant cells having different GR promoter methylation patterns. PMID:26242202

Priming of microglia in a DNA-repair deficient model of accelerated aging.

PubMed

Raj, Divya D A; Jaarsma, Dick; Holtman, Inge R; Olah, Marta; Ferreira, Filipa M; Schaafsma, Wandert; Brouwer, Nieske; Meijer, Michel M; de Waard, Monique C; van der Pluijm, Ingrid; Brandt, Renata; Kreft, Karim L; Laman, Jon D; de Haan, Gerald; Biber, Knut P H; Hoeijmakers, Jan H J; Eggen, Bart J L; Boddeke, Hendrikus W G M

2014-09-01

Aging is associated with reduced function, degenerative changes, and increased neuroinflammation of the central nervous system (CNS). Increasing evidence suggests that changes in microglia cells contribute to the age-related deterioration of the CNS. The most prominent age-related change of microglia is enhanced sensitivity to inflammatory stimuli, referred to as priming. It is unclear if priming is due to intrinsic microglia ageing or induced by the ageing neural environment. We have studied this in Ercc1 mutant mice, a DNA repair-deficient mouse model that displays features of accelerated aging in multiple tissues including the CNS. In Ercc1 mutant mice, microglia showed hallmark features of priming such as an exaggerated response to peripheral lipopolysaccharide exposure in terms of cytokine expression and phagocytosis. Specific targeting of the Ercc1 deletion to forebrain neurons resulted in a progressive priming response in microglia exemplified by phenotypic alterations. Summarizing, these data show that neuronal genotoxic stress is sufficient to switch microglia from a resting to a primed state. Copyright © 2014 Elsevier Inc. All rights reserved.

Age dependence of clinical and pathological manifestations of autoimmune demyelination. Implications for multiple sclerosis.

PubMed

Smith, M E; Eller, N L; McFarland, H F; Racke, M K; Raine, C S

1999-10-01

A prominent feature of the clinical spectrum of multiple sclerosis (MS) is its high incidence of onset in the third decade of life and the relative rarity of clinical manifestations during childhood and adolescence, features suggestive of age-related restriction of clinical expression. Experimental allergic encephalomyelitis (EAE), a model of central nervous system (CNS) autoimmune demyelination with many similarities to MS, has a uniform rapid onset and a high incidence of clinical and pathological disease in adult (mature) animals. Like MS, EAE is most commonly seen and studied in female adults. In this study, age-related resistance to clinical EAE has been examined with the adoptive transfer model of EAE in SJL mice that received myelin basic protein-sensitized cells from animals 10 days (sucklings) to 12 weeks (young adults) of age. A variable delay before expression of clinical EAE was observed between the different age groups. The preclinical period was longest in the younger (<14 days of age) animals, and shortest in animals 6 to 8 weeks old at time of transfer. Young animals initially resistant to EAE eventually expressed well-developed clinical signs by 6 to 7 weeks of age. This was followed by a remitting, relapsing clinical course. For each age at time of sensitization, increased susceptibility of females compared to males was observed. Examination of the CNS of younger animal groups during the preclinical period showed lesions of acute EAE. Older age groups developed onset of signs coincident with acute CNS lesions. This age-related resistance to clinical EAE in developing mice is reminiscent of an age-related characteristic of MS previously difficult to study in vivo. The associated subclinical CNS pathology and age-related immune functions found in young animals may be relevant to the increasing clinical expression of MS with maturation, and may allow study of factors associated with the known occasional poor correlation of CNS inflammation and demyelination and clinical changes in this disease.

[Clinical features of Enterococcus faecium meningitis in children].

PubMed

Wang, Li-Yuan; Cai, Xiao-Tang; Wang, Zhi-Ling; Liu, Shun-Li; Xie, Yong-Mei; Zhou, Hui

2018-03-01

To summarize the clinical features of Enterococcus faecium meningitis in children. The clinical data of nine children with Enterococcus faecium meningitis were analyzed. In all the nine children, Enterococcus faecium was isolated from blood, cerebrospinal fluid, or peripherally inserted central catheters; 6 (67%) patients were neonates, 2 (22%) patients were younger than 6 months, and 1 (11%) patient was three years and four months of age. In those patients, 56% had high-risk factors before onset, which included intestinal infection, resettlement of drainage tube after surgery for hydrocephalus, skull fracture, perinatal maternal infection history, and catheter-related infection. The main symptoms were fever and poor response. In those patients, 22% had seizures; no child had meningeal irritation sign or disturbance of consciousness. The white blood cell count and level of C-reactive protein were normal or increased; the nucleated cell count in cerebrospinal fluid was normal or mildly elevated; the protein level was substantially elevated; the glucose level was decreased. The drug sensitivity test showed that bacteria were all sensitive to vancomycin and the vancomycin treatment was effective. Only one child had the complication of hydrocephalus. Enterococcus faecium meningitis occurs mainly in neonates and infants. The patients have atypical clinical features. A high proportion of patients with Enterococcus faecium meningitis have high-risk factors. Enterococcus faecium is sensitive to vancomycin.

Solid polymeric electrolyte based dye-sensitized solar cell with improved stability

NASA Astrophysics Data System (ADS)

Prasad, Narottam; Kumar, Manish; Patel, K. R.; Roy, M. S.

2018-05-01

The impact of polymeric electrolyte was investigated over the performance of dye-sensitized solar cell made with Rose Bengal as sensitizer. Further, the selective influence of TiCl4 treatment and pre-sensitizer deoxycholic acid on nc-TiO2 photoanode was determined in terms of improvement in conversion efficiency of the cell. It is found that the effect of TiCl4 treatment was comparatively more than pre-sensitization with de-oxy cholic acid towards improving the efficiency of the cell. The conversion efficiency on TiCl4 treatment was 0.2% whereas on pre-sensitization with deoxy chollic acid it was 0.1%. The combined effect of both TiCl4 treatment & pre-sensitization with deoxycholic acid leads conversion efficiency to 0.33%.

STUDIES ON TUBERCULIN FEVER. 3. MECHANISMS INVOLVED IN THE RELEASE OF ENDOGENOUS PYROGEN IN VITRO.

PubMed

ATKINS, E; HEIJN, C

1965-08-01

In a search for the source of the circulating endogenous pyrogen (EP) that mediates tuberculin-induced fever, tuberculin was incubated in vitro with various tissues of rabbits sensitized by intravenous infection with BCG. Evidence was obtained that tuberculin specifically stimulates cells in the blood of sensitized rabbits to generate pyrogen in vitro, whereas both lymph node and spleen cells from the same donors were inactive. Since normal blood cells, incubated in plasma of sensitized donors, were similarly activated, it is postulated that circulating antibodies play a role in sensitizing cells (presumably granulocytes) to release pyrogen on contact with tuberculin) both in vitro and in vivo. Release of endogenous pyrogen in vitro may be a sensitive means of detecting immunologic reactions between antigen and specifically sensitized blood cells-in other allergic states accompanied by fever.

Transcriptional effect of an Aframomum angustifolium seed extract on human cutaneous cells using low-density DNA chips.

PubMed

Bonnet-Duquennoy, Mathilde; Dumas, Marc; Debacker, Adeline; Lazou, Kristell; Talbourdet, Sylvie; Franchi, Jocelyne; Heusèle, Catherine; André, Patrice; Schnebert, Sylvianne; Bonté, Frédéric; Kurfürst, Robin

2007-06-01

Studying photoexposed and photoprotected skin biopsies from young and aged women, it has been found that a specific zone, composed of the basal layers of the epidermis, the dermal epidermal junction, and the superficial dermis, is major target of aging and reactive oxygen species. We showed that this zone is characterized by significant variations at a transcriptional and/or protein levels. Using low-density DNA chip technology, we evaluated the effect of a natural mixture of Aframomum angustifolium seed extract containing labdane diterpenoids on these aging markers. Expression profiles of normal human fibroblasts (NHF) were studied using a customized cDNA macroarray system containing genes covering dermal structure, inflammatory responses, and oxidative stress defense mechanisms. For normal human keratinocyte (NHK) investigations, we chose OLISA technique, a sensitive and quantitative method developed by BioMérieux specifically designed to investigate cell death, proliferation, epidermal structure, differentiation, and oxidative stress defense response. We observed that this extract strongly modified gene expression profiles of treated NHK, but weakly for NHF. This extract regulated antioxidant defenses, dermal-epidermal junction components, and epidermal renewal-related genes. Using low-density DNA chip technology, we identified new potential actions of A. angustifolium seed extract on skin aging.

3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines.

PubMed

Qin, J-Z; Xin, H; Nickoloff, B J

2010-05-28

Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Krüppel-Like Factor 4 Enhances Sensitivity of Cisplatin to Esophageal Squamous Cell Carcinoma (ESCC) Cells

PubMed Central

Chen, Chuangui; Ma, Zhao; Zhang, Hongdian; Liu, Xiaoqiong; Yu, Zhentao

2017-01-01

Background The aim of this study was to elucidate the role of Krüppel-Like factor 4 (KLF4) in cisplatin resistance in esophageal squamous cell carcinoma (ESCC) cells, which may eventually help to improve the treatment efficacy. Material/Methods Human esophageal squamous cell carcinoma (ESCC) cell line CaEs-17, TE-1, EC109, KYSE510, KYSE140, KYSE70, and KYSE30 were selected to detect their sensitivity to cisplatin. 5-Azacytidine-2′-deoxycytidine (5′-Aza-CdR) treatment and methylation-specific PCR (MS-PCR) were used to detect the methylation status for KLF4. Cell viability, apoptosis, and cell cycle were measured using methyl thiazolyl tetrazolium (MTT) assay, Annexin V affinity assay, and flow cytometry, respectively. Results The sensitivity to cisplatin was different in the seven ESCC cell lines, with TE-1 having the lowest sensitivity and KYSE140 having the highest sensitivity. Interestingly, the level of KLF4 was relatively low in TE-1 cells; while it was high in KYSE140 cells. These results suggested that KLF4 may be involved in cisplatin resistance. The promoter region was mostly unmethylated in KYSE140 cells; while it was hypermethylated in TE-1 cells. After treatment with demethylation reagent 5-Aza-CdR, cisplatin sensitivities were significantly increased after upregulation of KLF4, as the IC50 values were significantly decreased in the TE-1 cell treated with 5-Aza-CdR. Furthermore, upregulation of KLF4 induced cell apoptosis and cell cycle arrest at S phase. Conclusions KLF4 enhances the sensitivity of cisplatin to ESCC cells through apoptosis induction and cell cycle arrest. Our data provided a novel insight to the mechanism of cisplatin resistance; overexpression of KLF4 may be a potential therapeutic strategy for cisplatin resistance in human ESCC. PMID:28694421

Krüppel-Like Factor 4 Enhances Sensitivity of Cisplatin to Esophageal Squamous Cell Carcinoma (ESCC) Cells.

PubMed

Chen, Chuangui; Ma, Zhao; Zhang, Hongdian; Liu, Xiaoqiong; Yu, Zhentao

2017-07-11

BACKGROUND The aim of this study was to elucidate the role of Krüppel-Like factor 4 (KLF4) in cisplatin resistance in esophageal squamous cell carcinoma (ESCC) cells, which may eventually help to improve the treatment efficacy. MATERIAL AND METHODS Human esophageal squamous cell carcinoma (ESCC) cell line CaEs-17, TE-1, EC109, KYSE510, KYSE140, KYSE70, and KYSE30 were selected to detect their sensitivity to cisplatin. 5-Azacytidine-2'-deoxycytidine (5'-Aza-CdR) treatment and methylation-specific PCR (MS-PCR) were used to detect the methylation status for KLF4. Cell viability, apoptosis, and cell cycle were measured using methyl thiazolyl tetrazolium (MTT) assay, Annexin V affinity assay, and flow cytometry, respectively. RESULTS The sensitivity to cisplatin was different in the seven ESCC cell lines, with TE-1 having the lowest sensitivity and KYSE140 having the highest sensitivity. Interestingly, the level of KLF4 was relatively low in TE-1 cells; while it was high in KYSE140 cells. These results suggested that KLF4 may be involved in cisplatin resistance. The promoter region was mostly unmethylated in KYSE140 cells; while it was hypermethylated in TE-1 cells. After treatment with demethylation reagent 5-Aza-CdR, cisplatin sensitivities were significantly increased after upregulation of KLF4, as the IC50 values were significantly decreased in the TE-1 cell treated with 5-Aza-CdR. Furthermore, upregulation of KLF4 induced cell apoptosis and cell cycle arrest at S phase. CONCLUSIONS KLF4 enhances the sensitivity of cisplatin to ESCC cells through apoptosis induction and cell cycle arrest. Our data provided a novel insight to the mechanism of cisplatin resistance; overexpression of KLF4 may be a potential therapeutic strategy for cisplatin resistance in human ESCC.

Age at the time of sulfonylurea initiation influences treatment outcomes in KCNJ11-related neonatal diabetes.

PubMed

Thurber, Brian W; Carmody, David; Tadie, Elizabeth C; Pastore, Ashley N; Dickens, Jazzmyne T; Wroblewski, Kristen E; Naylor, Rochelle N; Philipson, Louis H; Greeley, Siri Atma W

2015-07-01

Individuals with heterozygous activating mutations of the KCNJ11 gene encoding a subunit of the ATP-sensitive potassium channel (KATP) can usually be treated with oral sulfonylurea (SU) pills in lieu of insulin injections. The aim of this study was to test our hypothesis that younger age at the time of initiation of SU therapy is correlated with lower required doses of SU therapy, shorter transition time and decreased likelihood of requiring additional diabetes medications. We performed a retrospective cohort study using data on 58 individuals with neonatal diabetes due to KCNJ11 mutations identified through the University of Chicago Monogenic Diabetes Registry ( http://monogenicdiabetes.uchicago.edu/registry ). We assessed the influence of age at initiation of SU therapy on treatment outcomes. HbA1c fell from an average of 8.5% (69 mmol/mol) before transition to 6.2% (44 mmol/mol) after SU therapy (p < 0.001). Age of initiation of SU correlated with the dose (mg kg(-1) day(-1)) of SU required at follow-up (r = 0.80, p < 0.001). Similar associations were observed across mutation subtypes. Ten participants required additional glucose-lowering medications and all had initiated SU at age 13 years or older. No serious adverse events were reported. Earlier age at initiation of SU treatment is associated with improved response to SU therapy. Declining sensitivity to SU may be due to loss of beta cell mass over time in those treated with insulin. Our data support the need for early genetic diagnosis and appropriate personalised treatment in all cases of neonatal diabetes.

Redox sensing: Orthogonal control in cell cycle and apoptosis signaling

PubMed Central

Jones, Dean P.

2010-01-01

Living systems have three major types of cell signaling systems that are dependent upon high-energy chemicals, redox environment and transmembranal ion gating mechanisms. Development of integrated systems biology descriptions of cell signaling require conceptual models incorporating all three. Recent advances in redox biology show that thiol/disulfide redox systems are regulated under dynamic, non-equilibrium conditions, progressively oxidized with the life cycle of cells and distinct in terms of redox potentials among subcellular compartments. The present article uses these observations as a basis to distinguish “redox-sensing” mechanisms, which are more global biologic redox control mechanisms, from “redox signaling”, which involves conveyance of discrete activating or inactivating signals. Both redox sensing and redox signaling use sulfur switches, especially cysteine (Cys) residues in proteins which are sensitive to reversible oxidation, nitrosylation, glutathionylation, acylation, sulfhydration or metal binding. Unlike specific signaling mechanisms, the redox-sensing mechanisms provide means to globally affect the rates and activities of the high-energy, ion gating and redox-signaling systems by controlling sensitivity, distribution, macromolecular interactions and mobility of signaling proteins. Effects mediated through Cys residues not directly involved in signaling means redox-sensing control can be orthogonal to the signaling mechanisms. This provides a capability to integrate signals according to cell cycle and physiologic state without fundamentally altering the signaling mechanisms. Recent findings that thiol/disulfide pools in humans are oxidized with age, environmental exposures and disease risk suggest that redox-sensing thiols could provide a central mechanistic link in disease development and progression. PMID:20964735

Plasma stable, pH-sensitive fusogenic polymer-modified liposomes: A promising carrier for mitoxantrone.

PubMed

Ghanbarzadeh, Saeed; Arami, Sanam; Pourmoazzen, Zhaleh; Ghasemian-Yadegari, Javad; Khorrami, Arash

2014-07-01

pH-sensitive liposomes are designed to undergo acid-triggered destabilization. In the present study, we prepared polymer-modified, plasma stable, pH-sensitive fusogenic mitoxantrone liposomes to increase efficacy and selectivity on cancer cell lines. Conventional liposomes were prepared using cholesterol and dipalmitoyl-sn-glycero-3-phosphatidylethanolamine. Dioleoylphosphatidylethanolamine and a cholesteryl derivative, poly(monomethylitaconate)-co-poly(N,N-dimethylaminoethyl methacrylate) (PMMI-co-PDMAEMA), were used for the preparation of pH-sensitive fusogenic liposomes. Using polyethylene glycol (PEG)-poly(monomethylitaconate)-CholC6 (PEG-PMMI-CholC6) copolymers instead of cholesterol introduced pH-sensitive and plasma stability properties simultaneously in prepared liposomes. All formulations were prepared by thin film hydration method and subsequently, pH-sensitivity and stability in human serum were evaluated. The ability of pH-sensitive fusogenic liposomes to enhance the mitoxantrone cytotoxicity and selectivity in cancerous cell lines was assessed in vitro compared to normal cell line using human breast cancer cell line (MCF-7), human prostate cancer cell line (PC-3), and human umbilical vein endothelial cells line. Results revealed that both PMMI-co-PDMAEMA and PEG-PMMI-CholC6-based formulations showed pH-sensitive property and were found to rapidly release mitoxantrone under mildly acidic conditions. Nevertheless, only the PEG-PMMI-CholC6-based liposomes preserved pH-sensitivity after incubation in plasma. Mitoxantrone loaded-pH-sensitive fusogenic liposomes exhibited a higher cytotoxicity than the control conventional liposomes on MCF-7 and PC-3 cell lines. On the contrary, both pH-sensitive fusogenic liposomes showed lower cytotoxic effect on human umbilical vein endothelial cell line. Plasma stable, pH-sensitive fusogenic liposomes are promising carriers for enhancing the efficiency and selectivity, besides reduction of the side effects of anticancer agents. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Age-related sensitivity to endotoxin-induced liver inflammation: Implication of inflammasome/IL-1β for steatohepatitis

PubMed Central

Chung, Ki Wung; Lee, Eun Kyeong; Kim, Dae Hyun; An, Hye Jin; Kim, Nam Deuk; Im, Dong Soon; Lee, Jaewon; Yu, Byung Pal; Chung, Hae Young

2015-01-01

Aging is associated with increased vulnerability to inflammatory challenge. However, the effects of altered inflammatory response on the metabolic status of tissues or organs are not well documented. In this study, we present evidence demonstrating that lipopolysaccharide (LPS)-induced upregulation of the inflammasome/IL-1β pathway is accompanied with an increased inflammatory response and abnormal lipid accumulation in livers of aged rats. To monitor the effects of aging on LPS-induced inflammation, we administered LPS (2 mg kg−1) to young (6-month old) and aged (24-month old) rats and found abnormal lipid metabolism in only aged rats with increased lipid accumulation in the liver. This lipid accumulation in the liver was due to the dysregulation of PPARα and SREBP1c. We also observed severe liver inflammation in aged rats as indicated by increased ALT levels in serum and increased Kupffer cells in the liver. Importantly, among many inflammation-associated factors, the aged rat liver showed chronically increased IL-1β production. Increased levels of IL-1β were caused by the upregulation of caspase-1 activity and inflammasome activation. In vitro studies with HepG2 cells demonstrated that treatment with IL-1β significantly induced lipid accumulation in hepatocytes through the regulation of PPARα and SREBP1c. In summary, we demonstrated that LPS-induced liver inflammation and lipid accumulation were associated with a chronically overactive inflammasome/IL-1β pathway in aged rat livers. Based on the present findings, we propose a mechanism of aging-associated progression of steatohepatitis induced by endotoxin, delineating a pathogenic role of the inflammasome/IL-1β pathway involved in lipid accumulation in the liver. PMID:25847140

Factors Released from Endothelial Cells Exposed to Flow Impact Adhesion, Proliferation, and Fate Choice in the Adult Neural Stem Cell Lineage.

PubMed

Dumont, Courtney M; Piselli, Jennifer M; Kazi, Nadeem; Bowman, Evan; Li, Guoyun; Linhardt, Robert J; Temple, Sally; Dai, Guohao; Thompson, Deanna M

2017-08-15

The microvasculature within the neural stem cell (NSC) niche promotes self-renewal and regulates lineage progression. Previous work identified endothelial-produced soluble factors as key regulators of neural progenitor cell (NPC) fate and proliferation; however, endothelial cells (ECs) are sensitive to local hemodynamics, and the effect of this key physiological process has not been defined. In this study, we evaluated adult mouse NPC response to soluble factors isolated from static or dynamic (flow) EC cultures. Endothelial factors generated under dynamic conditions significantly increased neuronal differentiation, while those released under static conditions stimulated oligodendrocyte differentiation. Flow increases EC release of neurogenic factors and of heparin sulfate glycosaminoglycans that increase their bioactivity, likely underlying the enhanced neuronal differentiation. Additionally, endothelial factors, especially from static conditions, promoted adherent growth. Together, our data suggest that blood flow may impact proliferation, adhesion, and the neuron-glial fate choice of adult NPCs, with implications for diseases and aging that reduce flow.

Inhibition of WEE1 kinase and cell cycle checkpoint activation sensitizes head and neck cancers to natural killer cell therapies.

PubMed

Friedman, Jay; Morisada, Megan; Sun, Lillian; Moore, Ellen C; Padget, Michelle; Hodge, James W; Schlom, Jeffrey; Gameiro, Sofia R; Allen, Clint T

2018-06-21

Natural killer (NK) cells recognize and lyse target tumor cells in an MHC-unrestricted fashion and complement antigen- and MHC-restricted killing by T-lymphocytes. NK cells and T-lymphocytes mediate early killing of targets through a common granzyme B-dependent mechanism. Tumor cell resistance to granzyme B and how this alters NK cell killing is not clearly defined. Tumor cell sensitivity to cultured murine KIL and human high affinity NK (haNK) cells in the presence or absence of AZD1775, a small molecule inhibitor of WEE1 kinase, was assessed via real time impedance analysis. Mechanisms of enhanced sensitivity to NK lysis were determined and in vivo validation via adoptive transfer of KIL cells into syngeneic mice was performed. Cultured murine KIL cells lyse murine oral cancer 2 (MOC2) cell targets more efficiently than freshly isolated peripheral murine NK cells. MOC2 sensitivity to granzyme B-dependent KIL cell lysis was enhanced by inhibition of WEE1 kinase, reversing G2/M cell cycle checkpoint activation and resulting in enhanced DNA damage and apoptosis. Treatment of MOC2 tumor-bearing wild-type C57BL/6 mice with AZD1775 and adoptively transferred KIL cells resulted in enhanced tumor growth control and survival over controls or either treatment alone. Validating these findings in human models, WEE1 kinase inhibition sensitized two human head and neck cancer cell lines to direct lysis by haNK cells. Further, WEE1 kinase inhibition sensitized these cell lines to antibody-dependent cell-mediated cytotoxicity when combined with the anti-PD-L1 IgG1 mAb Avelumab. Tumor cell resistance to granzyme B-induced cell death can be reversed through inhibition of WEE1 kinase as AZD1775 sensitized both murine and human head and neck cancer cells to NK lysis. These data provide the pre-clinical rationale for the combination of small molecules that reverse cell cycle checkpoint activation and NK cellular therapies.

Comparative DNA microarray analysis of human monocyte derived dendritic cells and MUTZ-3 cells exposed to the moderate skin sensitizer cinnamaldehyde

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

Python, Francois; Goebel, Carsten; Aeby, Pierre

2009-09-15

The number of studies involved in the development of in vitro skin sensitization tests has increased since the adoption of the EU 7th amendment to the cosmetics directive proposing to ban animal testing for cosmetic ingredients by 2013. Several studies have recently demonstrated that sensitizers induce a relevant up-regulation of activation markers such as CD86, CD54, IL-8 or IL-1{beta} in human myeloid cell lines (e.g., U937, MUTZ-3, THP-1) or in human peripheral blood monocyte-derived dendritic cells (PBMDCs). The present study aimed at the identification of new dendritic cell activation markers in order to further improve the in vitro evaluation ofmore » the sensitizing potential of chemicals. We have compared the gene expression profiles of PBMDCs and the human cell line MUTZ-3 after a 24-h exposure to the moderate sensitizer cinnamaldehyde. A list of 80 genes modulated in both cell types was obtained and a set of candidate marker genes was selected for further analysis. Cells were exposed to selected sensitizers and non-sensitizers for 24 h and gene expression was analyzed by quantitative real-time reverse transcriptase-polymerase chain reaction. Results indicated that PIR, TRIM16 and two Nrf2-regulated genes, CES1 and NQO1, are modulated by most sensitizers. Up-regulation of these genes could also be observed in our recently published DC-activation test with U937 cells. Due to their role in DC activation, these new genes may help to further refine the in vitro approaches for the screening of the sensitizing properties of a chemical.« less

Neurotrophic Properties, Chemosensory Responses and Neurogenic Niche of the Human Carotid Body.

PubMed

Ortega-Sáenz, Patricia; Villadiego, Javier; Pardal, Ricardo; Toledo-Aral, Juan José; López-Barneo, José

2015-01-01

The carotid body (CB) is a polymodal chemoreceptor that triggers the hyperventilatory response to hypoxia necessary for the maintenance of O(2) homeostasis essential for the survival of organs such as the brain or heart. Glomus cells, the sensory elements in the CB, are also sensitive to hypercapnia, acidosis and, although less generally accepted, hypoglycemia. Current knowledge on CB function is mainly based on studies performed on lower mammals, but the information on the human CB is scant. Here we describe the structure, neurotrophic properties, and cellular responses to hypoxia and hypoglycemia of CBs dissected from human cadavers. The adult CB parenchyma contains clusters of chemosensitive glomus (type I) and sustentacular (type II) cells as well as nestin-positive progenitor cells. This organ also expresses high levels of the dopaminotrophic glial cell line-derived neurotrophic factor (GDNF). GDNF production and the number of progenitor and glomus cells were preserved in the CBs of human subjects of advanced age. As reported for other mammalian species, glomus cells responded to hypoxia by external Ca(2+)-dependent increase of cytosolic [Ca(2+)] and quantal catecholamine release. Human glomus cells are also responsive to hypoglycemia and together the two stimuli, hypoxia and hypoglycemia, can potentiate each other's effects. The chemo-sensory responses of glomus cells are also preserved at an advanced age. Interestingly, a neurogenic niche similar to that recently described in rodents is also preserved in the adult human CB. These new data on the cellular and molecular physiology of the CB pave the way for future pathophysiological studies involving this organ in humans.

NK sensitivity of neuroblastoma cells determined by a highly sensitive coupled luminescent method

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

Ogbomo, Henry; Hahn, Anke; Geiler, Janina

2006-01-06

The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe,more » and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients.« less

Plant and Animal Gravitational Biology. Part 2

NASA Technical Reports Server (NTRS)

1997-01-01

Session WA2 includes short reports concerning: (1) The Asymmetrical Growth of Otoliths in Fish Affected by Altered Gravity and Causes Kinetosis; (2) Neurobiological Responses of Fish to Altered Gravity conditions: A Review; (3) An Age-Dependent Sensitivity of the Roll-Induced Vestibulocular Reflex to Hypergravity Exposure of Several Days in an Amphibian (Xenopus Laevis); (4) Mechanically-Induced Membrane Wounding During Parabolic Flight; and (5) Erythropoietin Stimulates Increased F Cell Numbers in Bone Marrow Cultures Established in Gravity and Microgravity Conditions.

CD4 T lymphocytes from patients with chronic fatigue syndrome have decreased interferon-gamma production and increased sensitivity to dexamethasone.

PubMed

Visser, J; Blauw, B; Hinloopen, B; Brommer, E; de Kloet, E R; Kluft, C; Nagelkerken, L

1998-02-01

A disturbed hypothalamus-pituitary-adrenal gland axis and alterations at the immune system level have been observed in patients with chronic fatigue syndrome (CFS). Glucocorticoids are known to modulate T cell responses; therefore, purified CD4 T cells from CFS patients were studied to determine whether they have an altered sensitivity to dexamethasone (DEX). CD4 T cells from CFS patients produced less interferon-gamma than did cells from controls; by contrast, interleukin-4 production and cell proliferation were comparable. With CD4 T cells from CFS patients (compared with cells from controls), a 10- to 20-fold lower DEX concentration was needed to achieve 50% inhibition of interleukin-4 production and proliferation, indicating an increased sensitivity to DEX in CFS patients. Surprisingly, interferon-gamma production in patients and controls was equally sensitive to DEX. A differential sensitivity of cytokines or CD4 T cell subsets to glucocorticoids might explain an altered immunologic function in CFS patients.

Stem cells: Balancing resistance and sensitivity to DNA damage

PubMed Central

Liu, Julia C.; Lerou, Paul H.; Lahav, Galit

2015-01-01

Embryonic stem cells are known to be very sensitive to DNA damage and undergo rapid apoptosis even after low damage doses. In contrast, adult stem cells show variable sensitivity to damage. Here we describe the multiple pathways that have been proposed to affect the sensitivity of stem cells to damage, including proximity to the apoptotic threshold (mitochondrial priming) and the p53 signaling pathway, through activation of transcription or direct interaction with pro apoptotic proteins in the cytoplasm. We also discuss which cellular factors might connect mitochondrial priming with pluripotency and the potential therapeutic advances that can be achieved by better understanding the molecular mechanisms leading to sensitivity or resistance of embryonic or adult stem cells from different tissues. PMID:24721782

Disordered vascular compliance in haemochromatosis.

PubMed

Cash, W J; O'Neill, S; O'Donnell, M E; McCance, D R; Young, I S; McEneny, J; Cadden, I S; McDougall, Neil I; Callender, M E

2014-06-01

A relationship may exist between body iron stores, endothelial dysfunction and overall cardiovascular risk. To compare vascular compliance, biochemical endothelial function and antioxidant status between patients with homozygous hereditary haemochromatosis and healthy controls. Haemochromatosis patients and healthy controls were recruited. Measures of vascular compliance were assessed by applanation tonometry. Serological markers of endothelial function (plasma lipid hydroperoxides, cell adhesion molecules), antioxidant levels (ascorbate, lipid soluble antioxidants) and high-sensitivity C-reactive protein (CRP) were also measured. Thirty-five hereditary haemochromatosis patients (ten females, mean age 54.6) and 36 controls (27 female, mean age 54.0) were recruited. Haemochromatosis patients had significantly higher systolic and diastolic blood pressures. Pulse wave velocity (PWV) was significantly higher in male haemochromatosis patients (9.90 vs. 8.65 m/s, p = 0.048). Following adjustment for age and blood pressure, male haemochromatosis patients continued to have a trend for higher PWVs (+1.37 m/s, p = 0.058). Haemochromatosis patients had significantly lower levels of ascorbate (46.11 vs. 72.68 μmol/L, p = 0.011), retinol (1.17 vs. 1.81 μmol/L, p = 0.001) and g-tocopherol (2.51 vs. 3.14 μmol/L, p = 0.011). However, there was no difference in lipid hydroperoxides (0.46 vs. 0.47 nmol/L, p = 0.94), cell adhesion molecule levels (ICAM: 348.12 vs. 308.03 ng/mL, p = 0.32 and VCAM: 472.78 vs. 461.31 ng/mL, p = 0.79) or high-sensitivity CRP (225.01 vs. 207.13 mg/L, p = 0.32). Haemochromatosis is associated with higher PWVs in males and diminished antioxidants across the sexes but no evidence of endothelial dysfunction or increased lipid peroxidation.

Histone deacetylase inhibitor treatment induces ‘BRCAness’ and synergistic lethality with PARP inhibitor and cisplatin against human triple negative breast cancer cells

PubMed Central

Ha, Kyungsoo; Bhaskara, Srividya; Cerchietti, Leandro; Devaraj, Santhana G. T.; Shah, Bhavin; Sharma, Sunil; Chang, Jenny C.; Melnick, Ari M.; Hiebert, Scott; Bhalla, Kapil N.

2014-01-01

There is an unmet need to develop new, more effective and safe therapies for the aggressive forms of triple negative breast cancers (TNBCs). While up to 20% of women under 50 years of age with TNBC harbor germline mutations in BRCA1, and these tumors are sensitive to treatment with poly(ADP) ribose polymerase inhibitors, a majority of TNBCs lack BRCA1 mutations or loss of expression. Findings presented here demonstrate that by attenuating the levels of DNA damage response and homologous recombination proteins, pan-histone deacetylase inhibitor (HDI) treatment induces ‘BRCAness’ and sensitizes TNBC cells lacking BRCA1 to lethal effects of PARP inhibitor or cisplatin. Treatment with HDI also induced hyperacetylation of nuclear hsp90. Similar effects were observed following shRNA-mediated depletion of HDAC3, confirming its role as the deacetylase for nuclear HSP90. Furthermore, cotreatment with HDI and ABT-888 induced significantly more DNA strand breaks than either agent alone, and synergistically induced apoptosis of TNBC cells. Notably, co-treatment with HDI and ABT-888 significantly reduced in vivo tumor growth and markedly improved the survival of mice bearing TNBC cell xenografts. These findings support the rationale to interrogate the clinical activity of this novel combination against human TNBC, irrespective of its expression of mutant BRCA1. PMID:25026298

Redox Signaling and Bioenergetics Influence Lung Cancer Cell Line Sensitivity to the Isoflavone ME-344

PubMed Central

Manevich, Yefim; Reyes, Leticia; Britten, Carolyn D.; Townsend, Danyelle M.

2016-01-01

ME-344 [(3R,4S)-3,4-bis(4-hydroxyphenyl)-8-methyl-3,4-dihydro-2H-chromen-7-ol] is a second-generation derivative natural product isoflavone presently under clinical development. ME-344 effects were compared in lung cancer cell lines that are either intrinsically sensitive or resistant to the drug and in primary immortalized human lung embryonic fibroblasts (IHLEF). Cytotoxicity at low micromolar concentrations occurred only in sensitive cell lines, causing redox stress, decreased mitochondrial ATP production, and subsequent disruption of mitochondrial function. In a dose-dependent manner the drug caused instantaneous and pronounced inhibition of oxygen consumption rates (OCR) in drug-sensitive cells (quantitatively significantly less in drug-resistant cells). This was consistent with targeting of mitochondria by ME-344, with specific effects on the respiratory chain (resistance correlated with higher glycolytic indexes). OCR inhibition did not occur in primary IHLEF. ME-344 increased extracellular acidification rates in drug-resistant cells (significantly less in drug-sensitive cells), implying that ME-344 targets mitochondrial proton pumps. Only in drug-sensitive cells did ME-344 dose-dependently increase the intracellular generation of reactive oxygen species and cause oxidation of total (mainly glutathione) and protein thiols and the concomitant immediate increases in NADPH levels. We conclude that ME-344 causes complex, redox-specific, and mitochondria-targeted effects in lung cancer cells, which differ in extent from normal cells, correlate with drug sensitivity, and provide indications of a beneficial in vitro therapeutic index. PMID:27255112

Three distinct cell phenotypes of induced-TNF cytotoxicity and their relationship to apoptosis

NASA Technical Reports Server (NTRS)

Woods, K. M.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1993-01-01

We have identified three distinct cell phenotypes with respect to the conditions under which cells became susceptible to TNF-mediated lysis. These conditions include: 1) treatment with the protein synthesis inhibitor, cycloheximide; 2) contact with activated macrophages, and 3) infection with vaccinia virus. Whereas vaccinia virus-infected 3T3 cells became sensitive to soluble TNF, F5b cells required contact with activated macrophages. We showed that the "macrophage-resistant" F5m cells did not become sensitive to TNF or to killing by activated macrophages after infection with vaccinia virus. Therefore, vaccinia infection does not sensitize all cells to TNF. We also determined the pathways of lysis for cells after sensitization. Whereas 3T3, LM929, and F5b cells were killed by the process of necrosis, F5m cells lysis was characterized by the release of low mol wt DNA fragments (apoptosis).

Chronic stress from adolescence to aging in the prefrontal cortex: A neuroimmune perspective.

PubMed

Macht, Victoria A; Reagan, Lawrence P

2018-04-01

The development of the organism is a critical variable which influences the magnitude, duration, and reversibility of the effects of chronic stress. Such factors are relevant to the prefrontal cortex (PFC), as this brain region is the last to mature, the first to decline, and is highly stress-sensitive. Therefore, this review will examine the intersection between the nervous system and immune system at glutamatergic synapses in the PFC across three developmental periods: adolescence, adulthood, and aging. Glutamatergic synapses are tightly juxtaposed with microglia and astrocytes, and each of these cell types exhibits their own developmental trajectory. Not only does chronic stress differentially impact each of these cell types across development, but chronic stress also alters intercellular communication within this quad-partite synapse. These observations suggest that developmental shifts in both neural and immune function across neurons, microglia, and astrocytes mediate shifting effects of chronic stress on glutamatergic transmission. Copyright © 2018 Elsevier Inc. All rights reserved.

A Global Approach for Quantitative Super Resolution and Electron Microscopy on Cryo and Epoxy Sections Using Self-labeling Protein Tags.

PubMed

Müller, Andreas; Neukam, Martin; Ivanova, Anna; Sönmez, Anke; Münster, Carla; Kretschmar, Susanne; Kalaidzidis, Yannis; Kurth, Thomas; Verbavatz, Jean-Marc; Solimena, Michele

2017-02-02

Correlative light and electron microscopy (CLEM) is a powerful approach to investigate the molecular ultrastructure of labeled cell compartments. However, quantitative CLEM studies are rare, mainly due to small sample sizes and the sensitivity of fluorescent proteins to strong fixatives and contrasting reagents for EM. Here, we show that fusion of a self-labeling protein to insulin allows for the quantification of age-distinct insulin granule pools in pancreatic beta cells by a combination of super resolution and transmission electron microscopy on Tokuyasu cryosections. In contrast to fluorescent proteins like GFP organic dyes covalently bound to self-labeling proteins retain their fluorescence also in epoxy resin following high pressure freezing and freeze substitution, or remarkably even after strong chemical fixation. This enables for the assessment of age-defined granule morphology and degradation. Finally, we demonstrate that this CLEM protocol is highly versatile, being suitable for single and dual fluorescent labeling and detection of different proteins with optimal ultrastructure preservation and contrast.

Bone morphogenetic protein-7 (BMP-7) augments insulin sensitivity in mice with type II diabetes mellitus by potentiating PI3K/AKT pathway.

PubMed

Chattopadhyay, Tandrika; Singh, Rajiv Ranjan; Gupta, Sarika; Surolia, Avadhesha

2017-03-01

A direct link between development of insulin resistance and the presence of chronic inflammation, in case of obesity exists, with cytokines playing an important role in glucose metabolism. Members of TGF-β superfamily, including bone morphogenetic proteins (BMPs), have been shown to be involved in islet morphogenesis, establishment of β-cell mass and adipose cell fate determination. Here, we demonstrate a novel and direct role of BMP-4 and -7 in the regulation of glucose homeostasis and insulin resistance. An age-dependent increase in serum BMP-4 and decrease in serum BMP-7 levels was observed in animal models of type II diabetes. In this study, BMP-7 and -4 have been demonstrated to have antagonistic effects on insulin signaling and thereby on glucose homeostasis. BMP-7 augmented glucose uptake in the insulin sensitive tissues such as the adipose and muscle by increasing Glut4 translocation to the plasma membrane through phosphorylation and activation of PDK1 and Akt, and phosphorylation and translocation of FoxO1 to the cytoplasm in liver/HepG2 cells. Restoration of BMP-7 levels in serum of diabetic animals resulted in decreased blood glucose levels in contrast to age matched untreated control groups, opening up a new therapeutic avenue for diabetes. On the contrary, BMP-4 inhibited insulin signaling through activation of PKC-θ isoform, and resulted in insulin resistance through the attenuation of insulin signaling. BMP-7 therefore is an attractive candidate for tackling a multifaceted disease such as diabetes, since it not only reduces body fat, but also strengthens insulin signaling, causing improved glucose uptake and ameliorating peripheral insulin resistance. © 2017 BioFactors, 43(2):195-209, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Spatial contrast sensitivity - Effects of age, test-retest, and psychophysical method

NASA Technical Reports Server (NTRS)

Higgins, Kent E.; Jaffe, Myles J.; Caruso, Rafael C.; Demonasterio, Francisco M.

1988-01-01

Two different psychophysical methods were used to test the spatial contrast sensitivity in normal subjects from five age groups. The method of adjustment showed a decline in sensitivity with increasing age at all spatial frequencies, while the forced-choice procedure showed an age-related decline predominantly at high spatial frequencies. It is suggested that a neural component is responsible for this decline.

Epidemiology of pediatric nickel sensitivity: Retrospective review of North American Contact Dermatitis Group (NACDG) data 1994-2014.

PubMed

Warshaw, Erin M; Aschenbeck, Kelly A; DeKoven, Joel G; Maibach, Howard I; Taylor, James S; Sasseville, Denis; Belsito, Donald V; Fowler, Joseph F; Zug, Kathryn A; Zirwas, Matthew J; Fransway, Anthony F; DeLeo, Vincent A; Marks, James G; Pratt, Melanie D; Mathias, Toby

2018-04-14

Nickel is a common allergen responsible for allergic contact dermatitis. To characterize nickel sensitivity in children and compare pediatric cohorts (≤5, 6-12, and 13-18 years). Retrospective, cross-sectional analysis of 1894 pediatric patients patch tested by the North American Contact Dermatitis Group from 1994 to 2014. We evaluated demographics, rates of reaction to nickel, strength of nickel reactions, and nickel allergy sources. The frequency of nickel sensitivity was 23.7%. Children with nickel sensitivity were significantly less likely to be male (P < .0001; relative risk, 0.63; 95% confidence interval, 0.52-0.75) or have a history of allergic rhinitis (P = .0017; relative risk, 0.74; 95% confidence interval, 0.61-0.90) compared with those who were not nickel sensitive. In the nickel-sensitive cohort, the relative proportion of boys declined with age (44.8% for age ≤5, 36.6% for age 6-12, and 22.6% for age 13-18 years). The most common body site distribution for all age groups sensitive to nickel was scattered/generalized, indicating widespread dermatitis. Jewelry was the most common source associated with nickel sensitivity (36.4%). As a cross-sectional study, no long-term follow-up was available. Nickel sensitivity in children was common; the frequency was significantly higher in girls than in boys. Overall, sensitivity decreased with age. The most common source of nickel was jewelry. Published by Elsevier Inc.

Luminol-dependent chemiluminescence in antibody-sensitized neutrophils stimulated with protein A-bearing staphylococci.

PubMed

Nishihara, S; Seki, K; Ikigai, H; Masuda, S

1988-01-01

When mouse polymorphonuclear leukocytes (PMNs) sensitized with rabbit antibody to mouse Ehrlich ascites tumor cells were stimulated by Staphylococcus aureus Cowan I cells, a conspicuous luminol-dependent chemiluminescence was observed in the absence of opsonin. The profile of the chemiluminescence (CL) response evoked by staphylococcal cells from antibody-sensitized PMNs had two peaks. An initial peak, observed within 1 min after stimulation, was sharp and high and a second peak, observed about 5 min after stimulation, was low and extended. The CL response of antibody-sensitized PMNs stimulated by S. aureus Cowan I cells was dose-dependently blocked by preincubation with soluble SpA. Cells of a mutant derived from S. aureus Cowan I strain with trace amounts of cell-bound SpA failed to stimulate the antibody-sensitized PMNs to generate the CL response. The antibody-sensitized PMNs were found to phagocytize SpA-bearing S. aureus cells even in the absence of opsonic serum. These results suggest that the observation presented here might provide a useful tool for the investigation of CL response of PMNs.

Effects of protein kinase C activators on phorbol ester-sensitive and -resistant EL4 thymoma cells.

PubMed

Sansbury, H M; Wisehart-Johnson, A E; Qi, C; Fulwood, S; Meier, K E

1997-09-01

Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester-resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells.

Susceptibility of ATM-deficient pancreatic cancer cells to radiation.

PubMed

Ayars, Michael; Eshleman, James; Goggins, Michael

2017-05-19

Ataxia telangiectasia mutated (ATM) is inactivated in a significant minority of pancreatic ductal adenocarcinomas and may be predictor of treatment response. We determined if ATM deficiency renders pancreatic cancer cells more sensitive to fractionated radiation or commonly used chemotherapeutics. ATM expression was knocked down in three pancreatic cancer cell lines using ATM-targeting shRNA. Isogenic cell lines were tested for sensitivity to several chemotherapeutic agents and radiation. DNA repair kinetics were analyzed in irradiated cells using the comet assay. We find that while rendering pancreatic cancer cells ATM-deficient did not significantly change their sensitivity to several chemotherapeutics, it did render them exquisitely sensitized to radiation. Pancreatic cancer ATM status may help predict response to radiotherapy.

Insulin receptor substrate 1 expression enhances the sensitivity of 32D cells to chemotherapy-induced cell death

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

Porter, Holly A., E-mail: hport001@umaryland.edu; Molecular Medicine Program, University of Maryland School of Medicine, Baltimore, MD 21201; Carey, Gregory B., E-mail: gcarey@som.umaryland.edu

2012-08-15

The adapters IRS1 and IRS2 link growth factor receptors to downstream signaling pathways that regulate proliferation and survival. Both suppress factor-withdrawal-induced apoptosis and have been implicated in cancer progression. However, recent studies suggest IRS1 and IRS2 mediate differential functions in cancer pathogenesis. IRS1 promoted breast cancer proliferation, while IRS2 promoted metastasis. The role of IRS1 and IRS2 in controlling cell responses to chemotherapy is unknown. To determine the role of IRS1 and IRS2 in the sensitivity of cells to chemotherapy, we treated 32D cells lacking or expressing IRS proteins with various concentrations of chemotherapeutic agents. We found that expression ofmore » IRS1, in contrast to IRS2, enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. When IRS2 was expressed with IRS1, the cells no longer showed enhanced sensitivity. Expression of IRS1 did not alter the expression of pro- and anti-apoptotic proteins; however, 32D-IRS1 cells expressed higher levels of Annexin A2. In 32D-IRS1 cells, IRS1 and Annexin A2 were both located in cytoplasmic and membrane fractions. We also found that IRS1 coprecipitated with Annexin A2, while IRS2 did not. Decreasing Annexin A2 levels reduced 32D-IRS1 cell sensitivity to chemotherapy. These results suggest IRS1 enhances sensitivity to chemotherapy in part through Annexin A2. -- Highlights: Black-Right-Pointing-Pointer IRS1 enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. Black-Right-Pointing-Pointer This sensitivity is abrogated by the expression of IRS2. Black-Right-Pointing-Pointer Expressing IRS1 in 32D cells increased levels of Annexin A2. Black-Right-Pointing-Pointer Both IRS1 and Annexin A2 were located in cytoplasmic and membrane fractions. Black-Right-Pointing-Pointer Decreasing Annexin A2 in 32D-IRS1 cells abated their sensitivity to chemotherapy.« less

Increased lipolysis, diminished adipose tissue insulin sensitivity and impaired B-cell function relative to adipose tissue insulin sensitivity in obese youth with impaired glucose tolerance (IGT)

USDA-ARS?s Scientific Manuscript database

Despite evidence of insulin resistance and B-cell dysfunction in glucose metabolism in youth with prediabetes, the relationship between adipose tissue insulin sensitivity (ATIS) and B-cell function remains unknown. We investigated whole-body lipolysis, ATIS and B-cell function relative to ATIS [adip...

Experimental characterization of recurrent ovarian immature teratoma cells after optimal surgery.

PubMed

Tanaka, Tetsuji; Toujima, Saori; Utsunomiya, Tomoko; Yukawa, Kazunori; Umesaki, Naohiko

2008-07-01

Minimal optimal surgery without chemotherapy is often performed for patients with ovarian immature teratoma, which frequently occurs in young women who hope for future pregnancies. If tumors recur after the operation, anticancer drug chemotherapy is often administered, although few studies have highlighted differences between the recurrent and the primary tumor cells. Therefore, we have established experimental animal models of recurrent ovarian immature teratoma cells after optimal surgery and characterized the anticancer drug sensitivity and antigenicity of the recurrent tumors. Surgically-excised tumor cells of a grade II ovarian immature teratoma were cultured in vitro and transplanted into nude mice to establish stable cell lines. Differential drug sensitivity and antigenicity of the tumor cells were compared between the primary and the nude mouse tumors. Nude mouse tumor cells showed a normal 46XX karyotype. Cultured primary cells showed a remarkably high sensitivity to paclitaxel, docetaxel, adriamycin and pirarubicin, compared to peritoneal cancer cells obtained from a patient with ovarian adenocarcinomatous peritonitis. The drug sensitivity of teratoma cells to 5-fluorouracil, bleomycin or peplomycin was also significantly higher. However, there was no significant difference in sensitivity to platinum drugs between the primary teratoma and the peritoneal adenocarcinoma cells. As for nude mouse tumor cells, sensitivity to 12 anticancer drugs was significantly lower than that of the primary tumor cells, while there was little difference in sensitivity to carboplatin or peplomycin between the primary and nude mouse tumor cells. Flow cytometry showed that the expression of smooth muscle actin (SMA) significantly decreased in nude mouse tumor cells when compared to cultured primary cells. In conclusion, ovarian immature teratomas with normal karyotypes have a malignant potential to recur after minimal surgery. During nude mouse transplantation, SMA-overexpressing cells appeared to be selectively excluded and nude mouse tumor cells were less sensitive to the majority of anticancer drugs than the primary tumor cells. These results indicate that after optimal surgery for ovarian immature teratoma, recurrent cells can be more resistant to anticancer drugs than the primary tumors. Therefore, it is likely that adjuvant chemotherapy lowers the risk of ovarian immature teratomas recurring after optimal surgery. BEP and PBV regimens are frequently given to teratoma patients. However, paclitaxel/carboplatin or docetaxel/carboplatin, which are the most effective chemotherapy treatments for epithelial ovarian cancer patients, are considered to be an alternative regimen, especially in the prevention of reproductive toxicity.

3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines

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

Qin, J.-Z.; Xin, H.; Nickoloff, B.J., E-mail: bnickol@lumc.edu

2010-05-28

Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cellmore » killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.« less

Older Subjects with β-cell Dysfunction have an Accentuated Incretin Release.

PubMed

Garduno-Garcia, José de Jesús; Gastaldelli, Amalia; DeFronzo, Ralph A; Lertwattanarak, Raweewan; Holst, Jens J; Musi, Nicolas

2018-04-16

Insulin secretion declines with age and this contributes to the increased risk of developing impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) in older subjects. Insulin secretion is regulated by the incretin hormones glucagon-like peptide (GLP) 1 and glucose-dependent insulinotropic peptide (GIP). Here we tested the hypotheses that incretin release is reduced in older subjects, and that this decline is associated with β-cell dysfunction. 40 young (25±3 y) and 53 older (74±7 y) lean non-diabetic subjects underwent a 2 h oral glucose tolerance test (OGTT). Based on the OGTT, subjects were divided in 3 groups: young normal glucose tolerant (Y-NGT, n=40), older with NGT (O-NGT, n=32), and older with IGT (O-IGT, n=21). Plasma insulin, C-peptide, GLP-1, and GIP concentrations were measured every 15-30 min. We quantitated insulin sensitivity (Matsuda index) and insulin secretory rate (ISR) by deconvolution of C-peptide with the calculation of β-cell glucose sensitivity. Matsuda index, early phase ISR (0-30min) and parameters of β-cell function were reduced in O-IGT vs. Y-NGT, but not in O-NGT. GLP-1 concentrations were elevated in both older groups [GLP-1_AUC0-120 was 2.8±0.1 in Y-NGT, 3.8±0.5 in O-NGT, and 3.7±0.4 nmol/l∙120 min in O-IGT (P<0.05)] while GIP secretion was elevated in O-NGT vs. Y-NGT [GIP_AUC0-120 was 4.7±0.3 in Y-NGT, 6.0±0.4 in O-NGT, and 4.8±0.3 nmol/l∙120 min in O-IGT (P<0.05)]. Aging is associated with an exaggerated GLP-1 secretory response. However, this was not sufficient to increase insulin first phase release in O-IGT and overcome insulin resistance.

Constitutive and Stress-induced Expression of CCL5 Machinery in Rodent Retina

PubMed Central

Duncan, D'Anne S.; McLaughlin, William M.; Vasilakes, Noah; Echevarria, Franklin D.; Formichella, Cathryn R.; Sappington, Rebecca M.

2017-01-01

Signaling by inflammatory cytokines and chemokines is associated with neurodegeneration in disease and injury. Here we examined expression of the β-chemokine CCL5 and its receptors in the mouse retina and evaluated its relevance in glaucoma, a common optic neuropathy associated with sensitivity to intraocular pressure (IOP). Using quantitative PCR, fluorescent in situ hybridization, immunohistochemistry and quantitative image analysis, we found CCL5 mRNA and protein was constitutively expressed in the inner retina and synaptic layers. CCL5 appeared to associate with Müller cells and RGCs as well as synaptic connections between horizontal cells and bipolar cells in the OPL and amacrine cells, bipolar cells and RGCs in the IPL. Although all three high-affinity receptors (CCR5, CCR3, CCR1) for CCL5 were expressed constitutively, CCR5 expression was significantly higher than CCR3, which was also markedly greater than CCR1. Localization patterns for constitutive CCR5, CCR3 and CCR1 expression differed, particularly with respect to expression in inner retinal neurons. Stress-related expression of CCL5 was primarily altered in aged DBA/2 mice with elevated IOP. In contrast, changes in expression and localization of both CCR3 and CCR5 were evident not only in aged DBA/2 mice, but also in age-matched control mice and young DBA/2 mice. These groups do not exhibit elevated IOP, but possess either the aging stress (control mice) or the genetic predisposition to glaucoma (DBA/2 mice). Together, these data indicate that CCL5 and its high-affinity receptors are constitutively expressed in murine retina and differentially induced by stressors associated with glaucomatous optic neuropathy. Localization patterns further indicate that CCL5 signaling may be relevant for modulation of synapses in both health and disease, particularly in the inner plexiform layer. PMID:28936366

Attenuation of Replication Stress–Induced Premature Cellular Senescence to Assess Anti-Aging Modalities

PubMed Central

Zhao, Hong; Darzynkiewicz, Zbigniew

2014-01-01

Described is an in vitro model of premature senescence in pulmonary adenocarcinoma A549 cells induced by persistent DNA replication stress in response to treatment with the DNA damaging drug mitoxantrone (Mxt). The degree of cellular senescence, based on characteristic changes in cell morphology, is measured by laser scanning cytometry. Specifically, the flattening of cells grown on slides (considered the hallmark of cellular senescence) is measured as the decline in local intensity of DNA-associated DAPI fluorescence (represented by maximal pixels). This change is paralleled by an increase in nuclear area. Thus, the ratio of mean intensity of maximal pixels to nuclear area provides a very sensitive morphometric biomarker for the degree of senescence. This analysis is combined with immunocytochemical detection of senescence markers, such as overexpression of cyclin kinase inhibitors (e.g., p21WAF1) and phosphorylation of ribosomal protein S6 (rpS6), a key marker associated with aging/senescence that is detected using a phospho-specific antibody. These biomarker indices are presented in quantitative terms defined as a senescence index (SI), which is the fraction of the marker in test cultures relative to the same marker in exponentially growing control cultures. This system can be used to evaluate the anti-aging potential of test agents by assessing attenuation of maximal senescence. As an example, the inclusion of berberine, a natural alkaloid with reported anti-aging properties and a long history of use in traditional Chinese medicine, is shown to markedly attenuate the Mxt-induced SI and phosphorylation of rpS6. The multivariate analysis of senescence markers by laser scanning cytometry offers a promising tool to explore the potential anti-aging properties of a variety agents. PMID:24984966

Tumor-suppressive effects of natural-type interferon-β through CXCL10 in melanoma

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

Kobayashi, Hikaru; Nobeyama, Yoshimasa, E-mail: nobederm@jikei.ac.jp; Nakagawa, Hidemi

2015-08-21

Introduction: Type 1 interferon is in widespread use as adjuvant therapy to inhibit melanoma progression. Considering the tumor-suppressive effects of local administration of interferon-β (IFN-β) on lymphatic metastasis, the present study was conducted to identify melanoma-suppressive molecules that are up-regulated by IFN-β treatment of lymphatic endothelial cells. Materials and methods: Lymphatic endothelial cells, fibroblasts, and melanoma cells were treated with natural-type IFN-β, and melanoma cells were treated with CXCL10. Genome-wide oligonucleotide microarray analysis was performed using lymphatic endothelial cells with or without IFN-β treatment. Quantitative real-time reverse transcription-PCR and an enzyme-linked immunosorbent assay were performed to examine CXCL10 expression. Amore » proliferation assay was performed to examine the effects of IFN-β and CXCL10 in melanoma cells. Results: Genome-wide microarray analyses detected CXCL10 as a gene encoding a secretory protein that was up-regulated by IFN-β in lymphatic endothelial cells. IFN-β treatment significantly induced CXCL10 in dermal lymphatic endothelial cells and melanoma cells that are highly sensitive to IFN-β. CXCL10 reduced melanoma cell proliferation in IFN-β-sensitive cells as well as resistant cells. Melanoma cells in which CXCL10 was knocked down were sensitive to IFN-β. CXCR3-B, which encodes the CXCL10 receptor, was up-regulated in melanoma cells with high sensitivity to IFN-β and down-regulated in melanoma cells with medium to low sensitivity. Conclusions: Our data suggest that IFN-β suppresses proliferation and metastasis from the local lymphatic system and melanoma cells via CXCL10. Down-regulation of CXCR3-B by IFN-β may be associated with resistance to IFN-β. - Highlights: • We search melanoma-suppressive molecules induced by IFN-β. • IFN-β induces a high amount of CXCL10 from lymphatic endothelial cells. • CXCL10 induction level in melanoma cells is correlated with the sensitivity to IFN-β. • CXCL10 reduces proliferation in IFN-β-sensitive cells as well as resistant cells. • CXCR3-B is down-regulated by IFN-β exclusively in IFN-β-resistant cells.« less

Sensitivity of GBM cells to cAMP agonist-mediated apoptosis correlates with CD44 expression and agonist resistance with MAPK signaling.

PubMed

Daniel, Paul M; Filiz, Gulay; Mantamadiotis, Theo

2016-12-01

In some cell types, activation of the second messenger cAMP leads to increased expression of proapoptotic Bim and subsequent cell death. We demonstrate that suppression of the cAMP pathway is a common event across many cancers and that pharmacological activation of cAMP in glioblastoma (GBM) cells leads to enhanced BIM expression and apoptosis in specific GBM cell types. We identified the MAPK signaling axis as the determinant of cAMP agonist sensitivity in GBM cells, with high MAPK activity corresponding to cAMP resistance and low activity corresponding to sensitization to cAMP-induced apoptosis. Sensitive cells were efficiently killed by cAMP agonists alone, while targeting both the cAMP and MAPK pathways in resistant GBM cells resulted in efficient apoptosis. We also show that CD44 is differentially expressed in cAMP agonist-sensitive and -resistant cells. We thus propose that CD44 may be a useful biomarker for distinguishing tumors that may be sensitive to cAMP agonists alone or cAMP agonists in combination with other pathway inhibitors. This suggests that using existing chemotherapeutic compounds in combination with existing FDA-approved cAMP agonists may fast track trials toward improved therapies for difficult-to-treat cancers, such as GBM.

The Aging Navigational System.

PubMed

Lester, Adam W; Moffat, Scott D; Wiener, Jan M; Barnes, Carol A; Wolbers, Thomas

2017-08-30

The discovery of neuronal systems dedicated to computing spatial information, composed of functionally distinct cell types such as place and grid cells, combined with an extensive body of human-based behavioral and neuroimaging research has provided us with a detailed understanding of the brain's navigation circuit. In this review, we discuss emerging evidence from rodents, non-human primates, and humans that demonstrates how cognitive aging affects the navigational computations supported by these systems. Critically, we show 1) that navigational deficits cannot solely be explained by general deficits in learning and memory, 2) that there is no uniform decline across different navigational computations, and 3) that navigational deficits might be sensitive markers for impending pathological decline. Following an introduction to the mechanisms underlying spatial navigation and how they relate to general processes of learning and memory, the review discusses how aging affects the perception and integration of spatial information, the creation and storage of memory traces for spatial information, and the use of spatial information during navigational behavior. The closing section highlights the clinical potential of behavioral and neural markers of spatial navigation, with a particular emphasis on neurodegenerative disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Efficacy and safety of cytotoxic drug chemotherapy after first-line EGFR-TKI treatment in elderly patients with non-small-cell lung cancer harboring sensitive EGFR mutations.

PubMed

Imai, Hisao; Minemura, Hiroyuki; Sugiyama, Tomohide; Yamada, Yutaka; Kaira, Kyoichi; Kanazawa, Kenya; Kasai, Takashi; Kaburagi, Takayuki; Minato, Koichi

2018-05-08

Epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is effective as first-line chemotherapy for patients with advanced non-small-cell lung cancer (NSCLC) harboring sensitive EGFR mutations. However, whether the efficacy of second-line cytotoxic drug chemotherapy after first-line EGFR-TKI treatment is similar to that of first-line cytotoxic drug chemotherapy in elderly patients aged ≥ 75 years harboring sensitive EGFR mutations is unclear. Therefore, we aimed to investigate the efficacy and safety of cytotoxic drug chemotherapy after first-line EGFR-TKI treatment in elderly patients with NSCLC harboring sensitive EGFR mutations. We retrospectively evaluated the clinical effects and safety profiles of second-line cytotoxic drug chemotherapy after first-line EGFR-TKI treatment in elderly patients with NSCLC harboring sensitive EGFR mutations (exon 19 deletion/exon 21 L858R mutation). Between April 2008 and December 2015, 78 elderly patients with advanced NSCLC harboring sensitive EGFR mutations received first-line EGFR-TKI at four Japanese institutions. Baseline characteristics, regimens, responses to first- and second-line treatments, whether or not patients received subsequent treatment, and if not, the reasons for non-administration were recorded. Overall, 20 patients with a median age of 79.5 years (range 75-85 years) were included in our analysis. The overall response, disease control, median progression-free survival, and overall survival rates were 15.0, 60.0%, 2.4, and 13.2 months, respectively. Common adverse events included leukopenia, neutropenia, anemia, thrombocytopenia, malaise, and anorexia. Major grade 3 or 4 toxicities included leukopenia (25.0%) and neutropenia (45.0%). No treatment-related deaths were noted. Second-line cytotoxic drug chemotherapy after first-line EGFR-TKI treatment among elderly patients with NSCLC harboring sensitive EGFR mutations was effective and safe and showed equivalent outcomes to first-line cytotoxic drug chemotherapy.

Mitochondrial genome-knockout cells demonstrate a dual mechanism of action for the electron transport complex I inhibitor mycothiazole.

PubMed

Meyer, Kirsten J; Singh, A Jonathan; Cameron, Alanna; Tan, An S; Leahy, Dora C; O'Sullivan, David; Joshi, Praneta; La Flamme, Anne C; Northcote, Peter T; Berridge, Michael V; Miller, John H

2012-04-01

Mycothiazole, a polyketide metabolite isolated from the marine sponge Cacospongia mycofijiensis, is a potent inhibitor of metabolic activity and mitochondrial electron transport chain complex I in sensitive cells, but other cells are relatively insensitive to the drug. Sensitive cell lines (IC(50) 0.36-13.8 nM) include HeLa, P815, RAW 264.7, MDCK, HeLa S3, 143B, 4T1, B16, and CD4/CD8 T cells. Insensitive cell lines (IC(50) 12.2-26.5 μM) include HL-60, LN18, and Jurkat. Thus, there is a 34,000-fold difference in sensitivity between HeLa and HL-60 cells. Some sensitive cell lines show a biphasic response, suggesting more than one mechanism of action. Mitochondrial genome-knockout ρ(0) cell lines are insensitive to mycothiazole, supporting a conditional mitochondrial site of action. Mycothiazole is cytostatic rather than cytotoxic in sensitive cells, has a long lag period of about 12 h, and unlike the complex I inhibitor, rotenone, does not cause G(2)/M cell cycle arrest. Mycothiazole decreases, rather than increases the levels of reactive oxygen species after 24 h. It is concluded that the cytostatic inhibitory effects of mycothiazole on mitochondrial electron transport function in sensitive cell lines may depend on a pre-activation step that is absent in insensitive cell lines with intact mitochondria, and that a second lower-affinity cytotoxic target may also be involved in the metabolic and growth inhibition of cells.

Improving Accuracy of Influenza-Associated Hospitalization Rate Estimates

PubMed Central

Reed, Carrie; Kirley, Pam Daily; Aragon, Deborah; Meek, James; Farley, Monica M.; Ryan, Patricia; Collins, Jim; Lynfield, Ruth; Baumbach, Joan; Zansky, Shelley; Bennett, Nancy M.; Fowler, Brian; Thomas, Ann; Lindegren, Mary L.; Atkinson, Annette; Finelli, Lyn; Chaves, Sandra S.

2015-01-01

Diagnostic test sensitivity affects rate estimates for laboratory-confirmed influenza–associated hospitalizations. We used data from FluSurv-NET, a national population-based surveillance system for laboratory-confirmed influenza hospitalizations, to capture diagnostic test type by patient age and influenza season. We calculated observed rates by age group and adjusted rates by test sensitivity. Test sensitivity was lowest in adults >65 years of age. For all ages, reverse transcription PCR was the most sensitive test, and use increased from <10% during 2003–2008 to ≈70% during 2009–2013. Observed hospitalization rates per 100,000 persons varied by season: 7.3–50.5 for children <18 years of age, 3.0–30.3 for adults 18–64 years, and 13.6–181.8 for adults >65 years. After 2009, hospitalization rates adjusted by test sensitivity were ≈15% higher for children <18 years, ≈20% higher for adults 18–64 years, and ≈55% for adults >65 years of age. Test sensitivity adjustments improve the accuracy of hospitalization rate estimates. PMID:26292017

[Meta-analysis of risk factors of recurrence in patients with giant cell tumor on extremities].

PubMed

Li, Rongrui; Hu, Yongcheng

2014-12-23

To explore the risk factors of giant cell tumor on extremities for patients with postoperative recurrence. The literature reports published before June 2014 were searched in the electronic databases of CBM, CNKI, PUBNED, MEDLINE and EMBASE. Meta-analysis was performed by software Review Manager (Version 5.3). The odds ratios (OR) of gender, age, tumor site, Campanacci Classification, pathological fracture, selection of treatment and soft tissue invasion were analyzed with heterogeneity test. Publication bias were tested by funnel plot and fail-safe number.Sensitivity analysis was performed to assess the stability. A total of 15 case-control studies were identified. Age, location and type of surgery were associated with tumor recurrence. The combined OR (95%CI) was 1.83 (1.04-3.24) P = 0.04 for aged <20 years, 0.52(0.31-0.86) P = 0.01 for aged >40 years, 1.60 (1.06-2.42) P = 0.02 for distal radius, 0.35 (0.14-0.90) P = 0.03 for proximal humerus, 3.64 (1.88-7.04) P = 0.0001 for curettage,0.56 (0.35-0.91) P = 0.02 for curettage with PMMA, 1.79 (1.11-2.88) P = 0.02 for curettage with bone graft and adjuvant and 0.29 (0.12-0.66) P = 0.003 for resection respectively. There were not significant relationship between tumor recurrence and gender, tumor location (distal femur, proximal femur, distal tibia, proximal tibia), Jaffe staging, Campanacci classification,Enneking classification, pathological fracture, soft tissue invasion, extensive curettage, curettage with bone graft, curettage with polymethylmethacrylate and adjuvant (P > 0.05). Youth (aged <20 years), distal radius, curettage and curettage with bone graft and adjuvant are the risk factors for recurrence of giant cell tumor.However, advanced age (aged >40 years), proximal tibia, curettage with PMMA and resection appear to have lower risks for tumor recurrence.

Vitamin E Supplementation Reduces Cellular Loss in the Brain of a Premature Aging Mouse Model.

PubMed

La Fata, G; van Vliet, N; Barnhoorn, S; Brandt, R M C; Etheve, S; Chenal, E; Grunenwald, C; Seifert, N; Weber, P; Hoeijmakers, J H J; Mohajeri, M H; Vermeij, W P

2017-01-01

Aging is a highly complex biological process driven by multiple factors. Its progression can partially be influenced by nutritional interventions. Vitamin E is a lipid-soluble anti-oxidant that is investigated as nutritional supplement for its ability to prevent or delay the onset of specific aging pathologies, including neurodegenerative disorders. We aimed here to investigate the effect of vitamin E during aging progression in a well characterized mouse model for premature aging. Xpg-/- animals received diets with low (~2.5 mg/kg feed), medium (75 mg/kg feed) or high (375 mg/kg feed) vitamin E concentration and their phenotype was monitored during aging progression. Vitamin E content was analyzed in the feed, for stability reasons, and in mouse plasma, brain, and liver, for effectiveness of the treatment. Subsequent age-related changes were monitored for improvement by increased vitamin E or worsening by depletion in both liver and nervous system, organs sensitive to oxidative stress. Mice supplemented with high levels of vitamin E showed a delayed onset of age-related body weight decline and appearance of tremors when compared to mice with a low dietary vitamin E intake. DNA damage resulting in liver abnormalities such as changes in polyploidy, was considerably prevented by elevated amounts of vitamin E. Additionally, immunohistochemical analyses revealed that high intake of vitamin E, when compared with low and medium levels of vitamin E in the diet, reduces the number of p53-positive cells throughout the brain, indicative of a lower number of cells dying due to DNA damage accumulated over time. Our data underline a neuroprotective role of vitamin E in the premature aging animal model used in this study, likely via a reduction of oxidative stress, and implies the importance of improved nutrition to sustain health.

Detection of Bladder Cancer Via Microfluidic Immunoassay and Single-Cell DNA Copy Number Alteration Analysis of Captured Urinary Exfoliated Tumor Cells.

PubMed

Chen, Anqi; Fu, Guanghou; Xu, Zhijie; Sun, Yukun; Chen, Xiaoyi; Cheng, Kok Suen; Neoh, Kuang Hong; Tang, Zhewen; Chen, Shifu; Liu, Ming; Huang, Tanxiao; Dai, Yun; Wang, Qibo; Jin, Jing; Jin, Baiye; Han, Ray P S

2018-05-22

The increasing incidence of bladder cancer (BC) and its high rate of recurrence over a 5-year period necessitate the need for diagnosis and surveillance amelioration. Cystoscopy and urinary cytology are the current tools, and molecular techniques such as BTA stat, NMP22, survivin mRNA, and urovysion FISH have attracted attention, however, they suf-fer from insufficient sensitivity or specificity. We developed a novel microfluidic approach for harvesting intact urinary-exfoliated tumor cells (UETCs), either individually or in clus-ters, in a clean and segregated environment, which is crucial to minimize cross-contamination and misreads. To reliably and accurately identify UETC, our quantitative immunoassay involved concurrent use of two oncoproteins CK20 and CD44v6 antigen. CK20 is an intermediate filament protein overexpressed in urothelial tumors, and CD44v6 is a membrane adhesion molecule closely associated with cell invasion, tumor progression and metastatic spread. Single-cell whole-genome sequencing on 12 captured UETCs and copy number alteration analysis showed that 11/12 (91.7%) of the immunofluorescence-identified UETCs possessed genomic instability. A total of 79 BC patients and 43 age-matched normal controls (NC) were enrolled in the study. We detected considerably high-er UETC counts in BC patients versus the NC group [53.3 (10.7-1001.9) vs. 0.0 (0-3.0) UETCs/10 mL; p < 0.0001]. For BC detection, a stratified 10-fold cross-validation of train-ing data reveals an overall predictive accuracy of 0.84 (95%CI: 0.76-0.93) with a 89.8% (95%CI: 71.5-86.4%) for sensitivity and 71.5% (95%CI: 59.7-83.3%) for specificity. Overall, the microfluidic immunoassay demonstrates increased sensitivity and specificity com-pared to other techniques for the detection of bladder cancer. Copyright ©2018, American Association for Cancer Research.

To probe the equivalence and opulence of nanocrystal and nanotube based dye-sensitized solar cells

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

Jyoti, Divya, E-mail: divyabathla17@gmail.com; Mohan, Devendra

2016-05-06

Dye-Sensitized solar cells based on TiO{sub 2} nanocrystal and TiO{sub 2} nanotubes have been fabricated by a simple sol-gel hydrothermal process and their performances have been compared. Current density and voltage (JV) characteristics and incident photon to current conversion efficiency (IPCE) plots have been set as criterion to check which one is better as a photoanode candidate in dye-sensitized solar cell. It has been observed that although open circuit voltage values for both type of cells do not differ much still, nanotube based dye-sensitized solar cells are more successful having an efficiency value of 7.28%.

Variation of solar cell sensitivity and solar radiation on tilted surfaces

NASA Technical Reports Server (NTRS)

Klucher, T. M.

1978-01-01

The validity is studied that one of various insolation models used to compute solar radiation incident on tilted surfaces from global data measured on horizontal surfaces. The variation of solar cell sensitivity to solar radiation is determined over a wide range of atmospheric condition. A new model was formulated that reduced the deviations between measured and predicted insolation to less than 3 percent. Evaluation of solar cell sensitivity data indicates small change (2-3 percent) in sensitivity from winter to summer for tilted cells. The feasibility of using such global data as a means for calibrating terrestrial solar cells is discussed.

3′-Phosphoadenosine 5′-phosphosulfate synthase 1 (PAPSS1) knockdown sensitizes non-small cell lung cancer cells to DNA damaging agents

PubMed Central

Leung, Ada W. Y.; Dragowska, Wieslawa H.; Ricaurte, Daniel; Kwok, Brian; Mathew, Veena; Roosendaal, Jeroen; Ahluwalia, Amith; Warburton, Corinna; Laskin, Janessa J.; Stirling, Peter C.; Qadir, Mohammed A.; Bally, Marcel B.

2015-01-01

Standard treatment for advanced non-small cell lung cancer (NSCLC) with no known driver mutation is platinum-based chemotherapy, which has a response rate of only 30–33%. Through an siRNA screen, 3′-phosphoadenosine 5′-phosphosulfate (PAPS) synthase 1 (PAPSS1), an enzyme that synthesizes the biologically active form of sulfate PAPS, was identified as a novel platinum-sensitizing target in NSCLC cells. PAPSS1 knockdown in combination with low-dose (IC10) cisplatin reduces clonogenicity of NSCLC cells by 98.7% (p < 0.001), increases DNA damage, and induces G1/S phase cell cycle arrest and apoptosis. PAPSS1 silencing also sensitized NSCLC cells to other DNA crosslinking agents, radiation, and topoisomerase I inhibitors, but not topoisomerase II inhibitors. Chemo-sensitization was not observed in normal epithelial cells. Knocking out the PAPSS1 homolog did not sensitize yeast to cisplatin, suggesting that sulfate bioavailability for amino acid synthesis is not the cause of sensitization to DNA damaging agents. Rather, sensitization may be due to sulfation reactions involved in blocking the action of DNA damaging agents, facilitating DNA repair, promoting cancer cell survival under therapeutic stress or reducing the bioavailability of DNA damaging agents. Our study demonstrates for the first time that PAPSS1 could be targeted to improve the activity of multiple anticancer agents used to treat NSCLC. PMID:26220590

Silencing of secretory clusterin sensitizes NSCLC cells to V-ATPase inhibitors by downregulating survivin.

PubMed

Kim, Young-Sun; Jin, Hyeon-Ok; Hong, Sung-Eun; Song, Jie-Young; Hwang, Chang-Sun; Park, In-Chul

2018-01-08

Secretory clusterin (sCLU) is a stress-associated protein that confers resistance to therapy when overexpressed. In this study, we observed that the V-ATPase inhibitors bafilomycin A1 and concanamycin A significantly stimulated sCLU protein expression. Knockdown of sCLU with siRNA sensitized non-small cell lung cancer (NSCLC) cells to bafilomycin A1, suggesting that sCLU expression renders cells resistant to V-ATPase inhibitors. The dual PI3K/AKT and mTOR inhibitor BEZ235 suppressed sCLU expression and enhanced cell sensitivity induced by bafilomycin A1. Notably, sCLU knockdown further decreased the expression of the survivin protein by bafilomycin A1, and the ectopic expression of survivin alleviated the cell sensitivity by bafilomycin A1 and sCLU depletion, suggesting that increased sensitivity to sCLU depletion in the cells with V-ATPase inhibitors is due, at least in part, to the down-regulation of survivin. Taken together, we demonstrated that the depletion of sCLU expression enhances the sensitivity of NSCLC cells to V-ATPase inhibitors by decreasing survivin expression. Inhibition of the PI3K/AKT/mTOR pathway enhances the sensitivity of NSCLC cells to V-ATPase inhibitors, leading to decreased sCLU and survivin expression. Thus, we suggest that a combination of PI3K/AKT/mTOR inhibitors with V-ATPase inhibitors might be an effective approach for NSCLC treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

CdS/CdSe quantum dots and ZnPc dye co-sensitized solar cells with Au nanoparticles/graphene oxide as efficient modified layer.

PubMed

Chen, Cong; Cheng, Yu; Jin, Junjie; Dai, Qilin; Song, Hongwei

2016-10-15

Co-sensitization by using two or more sensitizers with complementary absorption spectra to expand the spectral response range is an effective approach to enhance device performance of quantum dot sensitized solar cells (QDSSCs). To improve the light-harvesting in the visible/near-infrared (NIR) region, organic dye zinc phthalocyanine (ZnPc) was combined with CdS/CdSe quantum dots (QDs) for co-sensitized solar cells based on ZnO inverse opals (IOs) as photoanode. The resulting co-sensitized device shows an efficient panchromatic spectral response feature to ∼750nm and presents an overall conversion efficiency of 4.01%, which is superior to that of the individual ZnPc-sensitized solar cells and CdS/CdSe-sensitized solar cells. Meanwhile, an Au nanoparticles/graphene oxide (Au NPs/GO) composite layer was successfully prepared to modify Cu2S counter electrode for the co-sensitized solar cells. Reducing the carrier recombination process by GO and catalytic process of Au NPs leads to increased power conversion efficiency(PCE) from 4.01 to 4.60% and sustainable stability remains ∼85% of its original value after 60min light exposure. In this paper, introduction of the organic dyes as co-sensitizer and Au NPs/GO as counter electrode modified layer has been proved to be an effective route to improve the performance of QDSSCs. Copyright © 2016 Elsevier Inc. All rights reserved.

Infra-red photoresponse of mesoscopic NiO-based solar cells sensitized with PbS quantum dot

PubMed Central

Raissi, Mahfoudh; Pellegrin, Yann; Jobic, Stéphane; Boujtita, Mohammed; Odobel, Fabrice

2016-01-01

Sensitized NiO based photocathode is a new field of investigation with increasing scientific interest in relation with the development of tandem dye-sensitized solar cells (photovoltaic) and dye-sensitized photoelectrosynthetic cells (solar fuel). We demonstrate herein that PbS quantum dots (QDs) represent promising inorganic sensitizers for NiO-based quantum dot-sensitized solar cells (QDSSCs). The solar cell sensitized with PbS quantum dot exhibits significantly higher photoconversion efficiency than solar cells sensitized with a classical and efficient molecular sensitizer (P1 dye = 4-(Bis-{4-[5-(2,2-dicyano-vinyl)-thiophene-2-yl]-phenyl}-amino)-benzoic acid). Furthermore, the system features an IPCE (Incident Photon-to-Current Efficiency) spectrum that spreads into the infra-red region, reaching operating wavelengths of 950 nm. The QDSSC photoelectrochemical device works with the complexes tris(4,4′-ditert-butyl-2,2′-bipyridine)cobalt(III/II) redox mediators, underscoring the formation of a long-lived charge-separated state. The electrochemical impedance spectrocopy measurements are consistent with a high packing of the QDs upon the NiO surface, the high density of which limits the access of the electrolyte and results in favorable light absorption cross-sections and a significant hole lifetime. These notable results highlight the potential of NiO-based photocathodes sensitized with quantum dots for accessing and exploiting the low-energy part of the solar spectrum in photovoltaic and photocatalysis applications. PMID:27125454

Autoimmune oophoritis in thymectomized mice: T cell requirement in adoptive cell transfer.

PubMed Central

Taguchi, O; Nishizuka, Y

1980-01-01

Experimental autoimmune oophoritis characterized by rapid loss of oocytes with infiltration of lymphocytes and circulating anti-oocyte antibodies could be induced in (C57Bl/6Cr x A/JCr)F1 mice after thymectomy (Tx) at a critical age of 3 days (Tx-3) but not 0. or 7 days after birth without any sensitization. The lesion of the ovary was passively transferred into neonatal, but not adult, mice 7 days after intraperitoneal (i.p.) injection of spleen cells (10(7)) obtained from syngeneic donors with oophoritis. In contrast, the lesion was never evoked in the recipient ovaries when spleen cells were prepared from Tx-3 mice ovariectomized at day 0. The spleen cells prepared from Tx-3 donors, depleted of T cells by incubation with anti-Thy 1.2 antiserum plus guinea-pig complement (GPC), showed no transfer capacity. However, the spleen cells prepared from the same donors, depleted of B cells with anti-Ig antiserum plus GPC, still kept the capacity to induce oophoritis. The results indicate the presence of autoreactive T cells against ovarian tissues in Tx-3 mice which are capable of inducing oophoritis. Images Fig. 1 Fig. 2 Fig. 3 PMID:6970639

GALLIUM CITRATE, A NEW SENSITIZER OF CELLS TO HYPERTHERMIA

PubMed Central

Shinohara, Kunio; Kawakami, Noriko; Kugotani, Maho; Nakano, Hisako

1988-01-01

The killing effects of heat were studied on cultured mammalian cells (L5178Y) pre‐incubated with gallium (Ga) citrate, which is a popular tumor‐imaging diagnostic agent. The cells showed higher sensitivity to heat when they were pre‐incubated with Ga‐citrate. The pre‐incubated cells showed decreased ATP levels, and this may be responsible for the heat‐sensitizing effect. PMID:3128502

Development of a high-sensitivity and portable cell using Helmholtz resonance for noninvasive blood glucose-level measurement based on photoacoustic spectroscopy.

PubMed

Tachibana, K; Okada, K; Kobayashi, R; Ishihara, Y

2016-08-01

We describe the possibility of high-sensitivity noninvasive blood glucose measurement based on photoacoustic spectroscopy (PAS). The demand for noninvasive blood glucose-level measurement has increased due to the explosive increase in diabetic patients. We have developed a noninvasive blood glucose-level measurement based on PAS. The conventional method uses a straight-type resonant cell. However, the cell volume is large, which results in a low detection sensitivity and difficult portability. In this paper, a small-sized Helmholtz-type resonant cell is proposed to improve detection sensitivity and portability by reducing the cell dead volume. First, the acoustic property of the small-sized Helmholtz-type resonant cell was evaluated by performing an experiment using a silicone rubber. As a result, the detection sensitivity of the small-sized Helmholtz-type resonant cell was approximately two times larger than that of the conventional straight-type resonant cell. In addition, the inside volume was approximately 30 times smaller. Second, the detection limits of glucose concentration were estimated by performing an experiment using glucose solutions. The experimental results showed that a glucose concentration of approximately 1% was detected by the small-sized Helmholtz-type resonant cell. Although these results on the sensitivity of blood glucose-level measurement are currently insufficient, they suggest that miniaturization of a resonance cell is effective in the application of noninvasive blood glucose-level measurement.

Production of interferon-gamma by in vivo tumor-sensitized T cells: Association with active antitumor immunity

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

Bursuker, I.; Pearce, M.T.

1990-02-01

The state of active immunity to Meth A fibrosarcoma in mice immunized with an admixture of Meth A cells and Propionibacterium acnes is associated with possession by the host of spleen cells capable of producing interferon-gamma (IFN-gamma) upon in vitro restimulation with irradiated tumor cells. The ability of spleen cells from immunized mice to produce IFN-gamma in response to irradiated Meth A cells decays as active antitumor immunity is replaced by a state of immunological memory. The IFN-producing cells are L3T4+Ly2+, cyclophosphamide-sensitive and radiosensitive T cells, as determined by their sensitivity to corresponding monoclonal antibodies and complement. The induction ofmore » IFN-gamma production by in vivo tumor-sensitized T cells is tumor specific, in that spleen cells from mice immunized against Meth A fibrosarcoma can produce IFN in response to irradiated Meth A cells but not in response to another syngeneic tumor M109 lung carcinoma.« less

The AAA protein Msp1 mediates clearance of excess tail-anchored proteins from the peroxisomal membrane

PubMed Central

Weir, Nicholas R; Kamber, Roarke A; Martenson, James S

2017-01-01

Msp1 is a conserved AAA ATPase in budding yeast localized to mitochondria where it prevents accumulation of mistargeted tail-anchored (TA) proteins, including the peroxisomal TA protein Pex15. Msp1 also resides on peroxisomes but it remains unknown how native TA proteins on mitochondria and peroxisomes evade Msp1 surveillance. We used live-cell quantitative cell microscopy tools and drug-inducible gene expression to dissect Msp1 function. We found that a small fraction of peroxisomal Pex15, exaggerated by overexpression, is turned over by Msp1. Kinetic measurements guided by theoretical modeling revealed that Pex15 molecules at mitochondria display age-independent Msp1 sensitivity. By contrast, Pex15 molecules at peroxisomes are rapidly converted from an initial Msp1-sensitive to an Msp1-resistant state. Lastly, we show that Pex15 interacts with the peroxisomal membrane protein Pex3, which shields Pex15 from Msp1-dependent turnover. In sum, our work argues that Msp1 selects its substrates on the basis of their solitary membrane existence. PMID:28906250

[Can MRI be used to distinguish between superficial and invasive transitional cell bladder cancer?].

PubMed

Tillou, X; Grardel, E; Fourmarier, M; Bernasconi, T; Demailly, M; Hakami, F; Saint, F; Petit, J

2008-07-01

To determine the sensitivity and specificity of MRI to distinguish between superficial and invasive transitional cell bladder cancer. Sixty patients (52 men and eight women) with a mean age of 66.8 years were assessed by bladder MRI between May 2002 and November 2005 for a primary bladder cancer diagnosed by endoscopy, followed by transurethral resection and histological examination of the bladder cancer. Patients presenting a discordance between MRI findings and histological examination were analysed. Imaging and pathology staging was concordant for 49 bladder cancers (40 superficial and nine invasive). Ten tumours considered to be invasive on MRI were superficial on histological examination and six of them relapsed at the resection scar at one or three months. The sensitivity of MRI was 80% for a specificity of 90% and a positive predictive value of 97.5%. MRI is a reliable examination to confirm the superficial nature of bladder cancer. When MRI and histological examination of a bladder cancer resection specimen are discordant, second look surgery is recommended to treat residual disease, which was present in 60% of cases in the present series.

Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation

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

Shirai, Hidenori; Fujimori, Hiroaki; Gunji, Akemi

Highlights: •Parg{sup −/−} ES cells were more sensitive to γ-irradiation than Parp-1{sup −/−} ES cells. •Parg{sup −/−} cells were more sensitive to carbon-ion irradiation than Parp-1{sup −/−} cells. •Parg{sup −/−} cells showed defects in DSB repair after carbon-ion irradiation. •PAR accumulation was enhanced after carbon-ion irradiation compared to γ-irradiation. -- Abstract: Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme involved in poly(ADP-ribose) degradation. Here, the effects of Parg deficiency on sensitivity to low and high linear-energy-transfer (LET) radiation were investigated in mouse embryonic stem (ES) cells. Mouse Parg{sup −/−} and poly(ADP-ribose) polymerase-1 deficient (Parp-1{sup −/−}) ES cells were used and responsesmore » to low and high LET radiation were assessed by clonogenic survival and biochemical and biological analysis methods. Parg{sup −/−} cells were more sensitive to γ-irradiation than Parp-1{sup −/−} cells. Transient accumulation of poly(ADP-ribose) was enhanced in Parg{sup −/−} cells. Augmented levels of phosphorylated H2AX (γ-H2AX) from early phase were observed in Parg{sup −/−} ES cells. The induction level of p53 phophorylation at ser18 was similar in wild-type and Parp-1{sup −/−} cells and apoptotic cell death process was mainly observed in the both genotypes. These results suggested that the enhanced sensitivity of Parg{sup −/−} ES cells to γ-irradiation involved defective repair of DNA double strand breaks. The effects of Parg and Parp-1 deficiency on the ES cell response to carbon-ion irradiation (LET13 and 70 keV/μm) and Fe-ion irradiation (200 keV/μm) were also examined. Parg{sup −/−} cells were more sensitive to LET 70 keV/μm carbon-ion irradiation than Parp-1{sup −/−} cells. Enhanced apoptotic cell death also accompanied augmented levels of γ-H2AX in a biphasic manner peaked at 1 and 24 h. The induction level of p53 phophorylation at ser18 was not different between wild-type and Parg{sup −/−} cells. The augmented level of poly(ADP-ribose) accumulation was noted after carbon-ion irradiation compared to γ-irradiation even in the wild-type cells. An enhanced poly(ADP-ribose) accumulation was further observed in Parg{sup −/−} cells. Both Parg{sup −/−} cells and Parp-1{sup −/−} cells did not show sensitization to Fe-ion irradiation. Parg deficiency sensitizes mouse ES cells to a wide therapeutic range of LET radiation through the effects on DNA double strand break repair responses and enhanced cell death.« less

Collapse of proteostasis represents an early molecular event in Caenorhabditis elegans aging.

PubMed

Ben-Zvi, Anat; Miller, Elizabeth A; Morimoto, Richard I

2009-09-01

Protein damage contributes prominently to cellular aging. To address whether this occurs at a specific period during aging or accumulates gradually, we monitored the biochemical, cellular, and physiological properties of folding sensors expressed in different tissues of C. elegans. We observed the age-dependent misfolding and loss of function of diverse proteins harboring temperature-sensitive missense mutations in all somatic tissues at the permissive condition. This widespread failure in proteostasis occurs rapidly at an early stage of adulthood, and coincides with a severely reduced activation of the cytoprotective heat shock response and the unfolded protein response. Enhancing stress responsive factors HSF-1 or DAF-16 suppresses misfolding of these metastable folding sensors and restores the ability of the cell to maintain a functional proteome. This suggests that a compromise in the regulation of proteostatic stress responses occurs early in adulthood and tips the balance between the load of damaged proteins and the proteostasis machinery. We propose that the collapse of proteostasis represents an early molecular event of aging that amplifies protein damage in age-associated diseases of protein conformation.

A Hybrid Tandem Solar Cell Combining a Dye-Sensitized and a Polymer Solar Cell.

PubMed

Shao, Zhipeng; Chen, Shuanghong; Zhang, Xuhui; Zhu, Liangzheng; Ye, Jiajiu; Dai, Songyuan

2016-06-01

A hybrid tandem solar cell was assambled by connecting a dye sensitized solar cell and a polymer solar cell in series. A N719 sensitized TiO2 was used as photocathode in dye-sensitized subcell, and a MEH-PPV/PCBM composite was used as active layer in the polymer subcell. The polymer subcell fabricated on the counter electrode of the dye sensitized solar cell. A solution processed TiO(x) layer was used as electron collection layer of the polymer sub cell and the charge recombination layer. The effects of the TiO(x) interlayer and the spectral overlap between the two sub cells have been studied and optimized. The results shows that a proper thickness of the TiO(x) layer is needed for tandem solar cells. Thick TiO(x) will enhance the series resistance, but too thin TiO(x), layer will damage the hole blocking effect and its hydrophilic. The resulting optimized tandem solar cells exhibited a power conversion efficiency of 1.28% with a V(oc) of 0.95 V under simulated 100 mW cm(-2) AM 1.5 illumination.

Redox Signaling and Bioenergetics Influence Lung Cancer Cell Line Sensitivity to the Isoflavone ME-344.

PubMed

Manevich, Yefim; Reyes, Leticia; Britten, Carolyn D; Townsend, Danyelle M; Tew, Kenneth D

2016-08-01

ME-344 [(3R,4S)-3,4-bis(4-hydroxyphenyl)-8-methyl-3,4-dihydro-2H-chromen-7-ol] is a second-generation derivative natural product isoflavone presently under clinical development. ME-344 effects were compared in lung cancer cell lines that are either intrinsically sensitive or resistant to the drug and in primary immortalized human lung embryonic fibroblasts (IHLEF). Cytotoxicity at low micromolar concentrations occurred only in sensitive cell lines, causing redox stress, decreased mitochondrial ATP production, and subsequent disruption of mitochondrial function. In a dose-dependent manner the drug caused instantaneous and pronounced inhibition of oxygen consumption rates (OCR) in drug-sensitive cells (quantitatively significantly less in drug-resistant cells). This was consistent with targeting of mitochondria by ME-344, with specific effects on the respiratory chain (resistance correlated with higher glycolytic indexes). OCR inhibition did not occur in primary IHLEF. ME-344 increased extracellular acidification rates in drug-resistant cells (significantly less in drug-sensitive cells), implying that ME-344 targets mitochondrial proton pumps. Only in drug-sensitive cells did ME-344 dose-dependently increase the intracellular generation of reactive oxygen species and cause oxidation of total (mainly glutathione) and protein thiols and the concomitant immediate increases in NADPH levels. We conclude that ME-344 causes complex, redox-specific, and mitochondria-targeted effects in lung cancer cells, which differ in extent from normal cells, correlate with drug sensitivity, and provide indications of a beneficial in vitro therapeutic index. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Cancer-specific production of N-acetylaspartate via NAT8L overexpression in non-small cell lung cancer and its potential as a circulating biomarker

PubMed Central

Lou, Tzu-Fang; Sethuraman, Deepa; Dospoy, Patrick; Srivastva, Pallevi; Kim, Hyun Seok; Kim, Joongsoo; Ma, Xiaotu; Chen, Pei-Hsuan; Huffman, Kenneth E.; Frink, Robin E.; Larsen, Jill E.; Lewis, Cheryl; Um, Sang-Won; Kim, Duk-Hwan; Ahn, Jung-Mo; DeBerardinis, Ralph J.; White, Michael A.; Minna, John D.; Yoo, Hyuntae

2015-01-01

In order to identify new cancer-associated metabolites that may be useful for early detection of lung cancer, we performed a global metabolite profiling of a non-small cell lung cancer (NSCLC) line and immortalized normal lung epithelial cells from the same patient. Among several metabolites with significant cancer/normal differences, we identified a unique metabolic compound, N-acetylaspartate (NAA) in cancer cells — undetectable in normal lung epithelium. NAA’s cancer-specific detection was validated in additional cancer and control lung cells as well as selected NSCLC patient tumors and control tissues. NAA’s cancer-specificity was further supported in our analysis of NAA synthetase (gene symbol: NAT8L) gene expression levels in The Cancer Genome Atlas: elevated NAT8L expression in approximately 40% of adenocarcinoma and squamous cell carcinoma cases (N=577), with minimal expression in all non-malignant lung tissues (N=74). We then showed that NAT8L is functionally involved in NAA production of NSCLC cells through siRNA-mediated suppression of NAT8L, which caused selective reduction of intracellular and secreted NAA. Our cell culture experiments also indicated that NAA biosynthesis in NSCLC cells depends on glutamine availability. For preliminary evaluation of NAA’s clinical potential as a circulating biomarker, we developed a sensitive NAA blood assay and found that NAA blood levels were elevated in 46% of NSCLC patients (N=13) in comparison with age-matched healthy controls (N=21) among individuals aged 55 years or younger. Taken together, these results indicate that NAA is produced specifically in NSCLC tumors through NAT8L overexpression and its extracellular secretion can be detected in blood. PMID:26511490

Pancreatic islet amyloidosis, β-cell apoptosis, and α-cell proliferation are determinants of islet remodeling in type-2 diabetic baboons

PubMed Central

Guardado-Mendoza, Rodolfo; Davalli, Alberto M.; Chavez, Alberto O.; Hubbard, Gene B.; Dick, Edward J.; Majluf-Cruz, Abraham; Tene-Perez, Carlos E.; Goldschmidt, Lukasz; Hart, John; Perego, Carla; Comuzzie, Anthony G.; Tejero, Maria Elizabeth; Finzi, Giovanna; Placidi, Claudia; La Rosa, Stefano; Capella, Carlo; Halff, Glenn; Gastaldelli, Amalia; DeFronzo, Ralph A.; Folli, Franco

2009-01-01

β-Cell dysfunction is an important factor in the development of hyperglycemia of type-2 diabetes mellitus, and pancreatic islet amyloidosis (IA) has been postulated to be one of the main contributors to impaired insulin secretion. The aim of this study was to evaluate the correlation of IA with metabolic parameters and its effect on islets of Langerhans remodeling and relative endocrine-cell volume in baboons. We sequenced the amylin peptide, determined the fibrillogenic propensities, and evaluated pancreatic histology, clinical and biochemical characteristics, and endocrine cell proliferation and apoptosis in 150 baboons with different metabolic status. Amylin sequence in the baboon was 92% similar to humans and showed superimposable fibrillogenic propensities. IA severity correlated with fasting plasma glucose (FPG) (r = 0.662, P < 0.001) and HbA1c (r = 0.726, P < 0.001), as well as with free fatty acid, glucagon values, decreased homeostasis model assessment (HOMA) insulin resistance, and HOMA-B. IA severity was associated with a decreased relative β-cell volume, and increased relative α-cell volume and hyperglucagonemia. These results strongly support the concept that IA and β-cell apoptosis in concert with α-cell proliferation and hypertrophy are key determinants of islets of Langerhans “dysfunctional remodeling” and hyperglycemia in the baboon, a nonhuman primate model of type-2 diabetes mellitus. The most important determinants of IA were age and FPG (R2 = 0.519, P < 0.0001), and different FPG levels were sensitive and specific to predict IA severity. Finally, a predictive model for islet amyloid severity was generated with age and FPG as required variables. PMID:19666551

Particle sensor array

NASA Technical Reports Server (NTRS)

Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor); Lieneweg, Udo (Inventor)

1994-01-01

A particle sensor array which in a preferred embodiment comprises a static random access memory having a plurality of ion-sensitive memory cells, each such cell comprising at least one pull-down field effect transistor having a sensitive drain surface area (such as by bloating) and at least one pull-up field effect transistor having a source connected to an offset voltage. The sensitive drain surface area and the offset voltage are selected for memory cell upset by incident ions such as alpha-particles. The static random access memory of the present invention provides a means for selectively biasing the memory cells into the same state in which each of the sensitive drain surface areas is reverse biased and then selectively reducing the reversed bias on these sensitive drain surface areas for increasing the upset sensitivity of the cells to ions. The resulting selectively sensitive memory cells can be used in a number of applications. By way of example, the present invention can be used for measuring the linear energy transfer of ion particles, as well as a device for assessing the resistance of CMOS latches to Cosmic Ray induced single event upsets. The sensor of the present invention can also be used to determine the uniformity of an ion beam.

Sensitivity of solar-cell performance to atmospheric variables. 2: Dissimilar cells at several locations

NASA Technical Reports Server (NTRS)

Klucher, T. M.; Hart, R. E.

1976-01-01

Several solar cells having dissimilar spectral response curves and cell construction were measured at various locations in the United States to determine sensitivity of cell performance to atmospheric water vapor and turbidity. The locations selected represent a broad range of summer atmospheric conditions, from clear and dry to turbid and humid. Cell short circuit current under direct normal incidence sunlight, the intensity, water vapor and turbidity were measured. Regression equations were developed from the limited data base in order to provide a single method of prediction of cell current sensitivity to the atmospheric variables.

Diagnostic accuracy of the urinalysis for urinary tract infection in infants <3 months of age.

PubMed

Schroeder, Alan R; Chang, Pearl W; Shen, Mark W; Biondi, Eric A; Greenhow, Tara L

2015-06-01

The 2011 American Academy of Pediatrics urinary tract infection (UTI) guideline suggests incorporation of a positive urinalysis (UA) into the definition of UTI. However, concerns linger over UA sensitivity in young infants. Infants with the same pathogenic organism in the blood and urine (bacteremic UTI) have true infections and represent a desirable population for examination of UA sensitivity. We collected UA results on a cross-sectional sample of 276 infants <3 months of age with bacteremic UTI from 11 hospital systems. Sensitivity was calculated on infants who had at least a partial UA performed and had ≥50 000 colony-forming units per milliliter from the urine culture. Specificity was determined by using a random sample of infants from the central study site with negative urine cultures. The final sample included 245 infants with bacteremic UTI and 115 infants with negative urine cultures. The sensitivity of leukocyte esterase was 97.6% (95% confidence interval [CI] 94.5%-99.2%) and of pyuria (>3 white blood cells/high-power field) was 96% (95% CI 92.5%-98.1%). Only 1 infant with bacteremic UTI (Group B Streptococcus) and a complete UA had an entirely negative UA. In infants with negative urine cultures, leukocyte esterase specificity was 93.9% (95% CI 87.9 - 97.5) and of pyuria was 91.3% (84.6%-95.6%). In young infants with bacteremic UTI, UA sensitivity is higher than previous reports in infants with UTI in general. This finding can be explained by spectrum bias or by inclusion of faulty gold standards (contaminants or asymptomatic bacteriuria) in previous studies. Copyright © 2015 by the American Academy of Pediatrics.

Photodynamic inactivation of Candida albicans sensitized by tri- and tetra-cationic porphyrin derivatives.

PubMed

Cormick, M Paula; Alvarez, M Gabriela; Rovera, Marisa; Durantini, Edgardo N

2009-04-01

The photodynamic action of 5-(4-trifluorophenyl)-10,15,20-tris(4-trimethylammoniumphenyl)porphyrin iodide (TFAP(3+)) and 5,10,15,20-tetra(4-N,N,N-trimethylammonium phenyl)porphyrin p-tosylate (TMAP(4+)) has been studied in vitro on Candida albicans. The results of these cationic porphyrins were compared with those of 5,10,15,20-tetra(4-sulphonatophenyl)porphyrin (TPPS(4-)), which characterizes an anionic sensitizer. In vitro investigations show that these cationic porphyrins are rapidly bound to C. albicans cells, reaching a value of approximately 1.4 nmol/10(6) cells, when the cellular suspensions were incubated with 5 microM sensitizer for 30 min. In contrast, TPPS(4-) is poorly uptaken by yeast cells. The fluorescence spectra of these sensitizers into the cells confirm this behaviour. The amount of porphyrin binds to cells is dependent on both sensitizer concentrations (1-5 microM) and cells densities (10(6)-10(8) cells/mL). Photosensitized inactivation of C. albicans cellular suspensions increases with sensitizer concentration, causing a approximately 5 log decrease of cell survival, when the cultures are treated with 5 microM of cationic porphyrin and irradiated for 30 min. However, the photocytotoxicity decreases with an increase in the cell density, according to its low binding to cells. Under these conditions, the photodynamic activity of TFAP(3+) is quite similar to that produced by TMAP(4+), whereas no important inactivation effect was found for TPPS(4)(-). The high photodynamic activity of cationic porphyrins was confirmed by growth delay experiments. Thus, C. albicans cell growth was not detected in the presence of 5 microM TFAP(3+). Photodynamic inactivation capacities of these sensitizers were also evaluated on C. albicans cells growing in colonies on agar surfaces. Cationic porphyrins produce a growth delay of C. albicans colonies and viability of cells was not observed after 3 h irradiation, indicating a complete inactivation of yeast cells. Therefore, these results indicate that these cationic porphyrins are interesting sensitizers for photodynamic inactivation of yeasts in liquid suspensions or in localized foci of infection.

A NEW SENSITIVE ASSAY FOR ANTIBODY AGAINST CELL SURFACE ANTIGENS BASED ON INHIBITION OF CELL-DEPENDENT ANTIBODY-MEDIATED CYTOTOXICITY

PubMed Central

Halloran, Phil; Schirrmacher, Volker; Festenstein, Hilliard

1974-01-01

Inhibition of cell-dependent antibody-mediated cytotoxicity has been investigated as a new assay for antibody against cell surface antigens. The cytotoxicity system consisted of effector cells (normal mouse spleen cells), target cells (61Cr-labeled chicken erythrocytes), and antitarget cell antibody. Addition of antibody against cell surface antigens in the effector cell population regularly inhibited the cytotoxicity measured in this system. This cytotoxicity inhibition assay (CIA) detected antibody with a variety of specificities: anti-H-2, anti-Thy 1.2, anti-immunoglobulin, and antimouse bone marrow-derived lymphocyte antigen. When the inhibition by anti-H-2 sera was analyzed using effector cells from congenic mice, the activity was found to be directed against specificities mapping in the H-2K, H-2D, and I regions of the H-2 complex, correlating well with the specificities characterized by complement-dependent assays. A comparison between the sensitivity of the CIA and complement-dependent lysis revealed that the CIA was 2–11 times more sensitive for anti-H-2 antisera and 20–780 times more sensitive for certain antisera against subpopulations of the spleen cells (i.e., T cells or B cells). The CIA proved to be precise, sensitive, and reliable. It may become a very useful antibody assay in various species including man. PMID:4547657

Calcium influences sensitivity to growth inhibition induced by a cell surface sialoglycopeptide

NASA Technical Reports Server (NTRS)

Betz, N. A.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

1994-01-01

While studies concerning mitogenic factors have been an important area of research for many years, much less is understood about the mechanisms of action of cell surface growth inhibitors. We have purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) which can reversibly inhibit the proliferation of diverse cell types. The studies discussed in this article show that three mouse keratinocyte cell lines exhibit sixty-fold greater sensitivity than other fibroblasts and epithelial-like cells to CeReS-18-induced growth inhibition. Growth inhibition induced by CeReS-18 treatment is a reversible process, and the three mouse keratinocyte cell lines exhibited either single or multiple cell cycle arrest points, although a predominantly G0/G1 cell cycle arrest point was exhibited in Swiss 3T3 fibroblasts. The sensitivity of the mouse keratinocyte cell lines to CeReS-18-induced growth inhibition was not affected by the degree of tumorigenic progression in the cell lines and was not due to differences in CeReS-18 binding affinity or number of cell surface receptors per cell. However, the sensitivity of both murine fibroblasts and keratinocytes could be altered by changing the extracellular calcium concentration, such that increased extracellular calcium concentrations resulted in decreased sensitivity to CeReS-18-induced proliferation inhibition. Thus the increased sensitivity of the murine keratinocyte cell lines to CeReS-18 could be ascribed to the low calcium concentration used in their propagation. Studies are currently under way investigating the role of calcium in CeReS-18-induced growth arrest. The CeReS-18 may serve as a very useful tool to study negative growth control and the signal transduction events associated with cell cycling.

Polychromatic Light (480-3400 nm) Upregulates Sensitivity of Tumor Cells to Lysis by Natural Killers.

PubMed

Knyazev, Nickolay A; Samoilova, Kira A; Abrahamse, Heidi; Filatova, Natalia A

2016-09-01

This study evaluates the participation of immunological mechanisms of downregulation of murine hepatoma cells MH22a after direct exposure to polychromatic polarized light. Previous studies have shown that exposure to a combination of visible (VIS) and infrared (IR) light leads to decreased tumorigenicity of the murine hepatoma cells MH22a, which correlated with an increase in the amount of cells with reorganized cytoskeleton in the submembrane region. The mechanism of tumor inhibition and elimination has not been determined. Polychromatic light (480-3400 nm) has been used at doses of 4.8 and 9.6 J/cm(2) to determine the sensitivity of murine MH22a cells and human erythroleukemia cells K562 exposed to this light, to lysis by effector cells of innate immunity (NK cells), and enhancement of the glycocalyx of the studied tumor cells. This was determined using flow cytometry, the H(3)-uridine cytotoxic test followed by spectrophotometry. VIS-IR light increases the sensitivity of MH-22a cells at a dose 4.8 J/cm(2) and K562 cells at 9.6 J/cm(2). The enhancement of sensitivity of tumor cells to NK lysis changed their ability to absorb alcian blue, reflecting a change in the expression of the glycocalyx. Increasing the sensitivity of the murine tumor cells MH22a and human K562 irradiated VIS-IR light correlated with a change in the expression of their glycocalyx. The results of the present study demonstrate that the reduction of tumorigenicity of irradiated tumor cells is due to their sensitivity to lysis by NK cells of the immune system.

Pregnancy at early age is associated with a reduction of progesterone-responsive cells and epithelial Wnt signaling in human breast tissue.

PubMed

Muenst, Simone; Mechera, Robert; Däster, Silvio; Piscuoglio, Salvatore; Ng, Charlotte K Y; Meier-Abt, Fabienne; Weber, Walter P; Soysal, Savas D

2017-04-04

Pregnancy at early age is the most significant modifiable factor which consistently decreases lifetime breast cancer risk. However, the underlying mechanisms haven't been conclusively identified. Studies in mice suggest a reduction in progesterone-receptor (PR) sensitive epithelial cells as well as a downregulation of the Wnt signaling pathway as being one of the main mechanisms for the protective effect of early pregnancy. The aim of our study was to validate these findings in humans. We collected benign breast tissue of 125 women who had been stratified according to age at first pregnancy and the occurrence of subsequent breast cancer, and performed immunohistochemistry for PR, Wnt4 and the Wnt-target Versican. The number of PR positive epithelial cells was significantly lower in the group of women with early pregnancy and no subsequent breast cancer compared to the group of nulliparous women with subsequent invasive breast cancer (p = 0.0135). In women with early pregnancy, expression of Versican and Wnt4 was significantly lower compared to nulliparous women (p = 0.0036 and p = 0.0241 respectively), and Versican expression was also significant lower compared to women with late pregnancy (p < 0.0001). Our results confirm prior observations in mice and suggest a role of downregulation of epithelial Wnt signaling in the protective effect of early pregnancy in humans. This results in a decreased proliferation of stem/progenitor cells; therefore, the Wnt signaling pathway may represent a potential target for breast cancer prevention in humans.

Targeting cholesterol synthesis increases chemoimmuno-sensitivity in chronic lymphocytic leukemia cells

PubMed Central

2014-01-01

Background Cholesterol plays an important role in cancer development, drug resistance and chemoimmuno-sensitivity. Statins, cholesterol lowering drugs, can induce apoptosis, but also negatively interfere with CD-20 and rituximab-mediated activity. Our goal is to identify the alternative targets that could reduce cholesterol levels but do not interfere with CD-20 in chemo immunotherapy of chronic lymphocytic leukemia (CLL). Methods MEC-2 cells, a CLL cell line, and the peripheral blood mononuclear cells (PBMCs) from CLL patients were treated with cholesterol lowering agents, and analyzed the effect of these agents on cholesterol levels, CD-20 expression and distribution, and cell viability in the presence or absence of fludarabine, rituximab or their combinations. Results We found that MEC-2 cells treated with cholesterol lowering agents (BIBB-515, YM-53601 or TAK-475) reduced 20% of total cellular cholesterol levels, but also significantly promoted CD-20 surface expression. Furthermore, treatment of cells with fludarabine, rituximab or their combinations in the presence of BIBB-515, YM-53601 or TAK-475 enhanced MEC-2 cell chemoimmuno-sensitivity measured by cell viability. More importantly, these cholesterol lowering agents also significantly enhanced chemoimmuno-sensitivity of the PBMCs from CLL patients. Conclusion Our data demonstrate that BIBB-515, YM53601 and TAK-475 render chemoimmuno-therapy resistant MEC-2 cells sensitive to chemoimmuno-therapy and enhance CLL cell chemoimmuno-sensitivity without CD-20 epitope presentation or its downstream signaling. These results provide a novel strategy which could be applied to CLL treatment. PMID:25401046

Targeting cholesterol synthesis increases chemoimmuno-sensitivity in chronic lymphocytic leukemia cells.

PubMed

Benakanakere, Indira; Johnson, Tyler; Sleightholm, Richard; Villeda, Virgilio; Arya, Monika; Bobba, Ravi; Freter, Carl; Huang, Chunfa

2014-01-01

Cholesterol plays an important role in cancer development, drug resistance and chemoimmuno-sensitivity. Statins, cholesterol lowering drugs, can induce apoptosis, but also negatively interfere with CD-20 and rituximab-mediated activity. Our goal is to identify the alternative targets that could reduce cholesterol levels but do not interfere with CD-20 in chemo immunotherapy of chronic lymphocytic leukemia (CLL). MEC-2 cells, a CLL cell line, and the peripheral blood mononuclear cells (PBMCs) from CLL patients were treated with cholesterol lowering agents, and analyzed the effect of these agents on cholesterol levels, CD-20 expression and distribution, and cell viability in the presence or absence of fludarabine, rituximab or their combinations. We found that MEC-2 cells treated with cholesterol lowering agents (BIBB-515, YM-53601 or TAK-475) reduced 20% of total cellular cholesterol levels, but also significantly promoted CD-20 surface expression. Furthermore, treatment of cells with fludarabine, rituximab or their combinations in the presence of BIBB-515, YM-53601 or TAK-475 enhanced MEC-2 cell chemoimmuno-sensitivity measured by cell viability. More importantly, these cholesterol lowering agents also significantly enhanced chemoimmuno-sensitivity of the PBMCs from CLL patients. Our data demonstrate that BIBB-515, YM53601 and TAK-475 render chemoimmuno-therapy resistant MEC-2 cells sensitive to chemoimmuno-therapy and enhance CLL cell chemoimmuno-sensitivity without CD-20 epitope presentation or its downstream signaling. These results provide a novel strategy which could be applied to CLL treatment.

Specific down-regulation of XIAP with RNA interference enhances the sensitivity of canine tumor cell-lines to TRAIL and doxorubicin

PubMed Central

Spee, Bart; Jonkers, Martijn DB; Arends, Brigitte; Rutteman, Gerard R; Rothuizen, Jan; Penning, Louis C

2006-01-01

Background Apoptosis resistance occurs in various tumors. The anti-apoptotic XIAP protein is responsible for inhibiting apoptosis by reducing caspase-3 activation. Our aim is to evaluate whether RNA inhibition against XIAP increases the sensitivity of canine cell-lines for chemotherapeutics such as TRAIL and doxorubicin. We used small interfering RNA's (siRNA) directed against XIAP in three cell-lines derived from bile-duct epithelia (BDE), mammary carcinoma (P114), and osteosarcoma (D17). These cell-lines represent frequently occurring canine cancers and are highly comparable to their human counterparts. XIAP down-regulation was measured by means of quantitative PCR (Q-PCR) and Western blotting. The XIAP depleted cells were treated with a serial dilution of TRAIL or doxorubicin and compared to mock- and nonsense-treated controls. Viability was measured with a MTT assay. Results All XIAP siRNA treated cell-lines showed a mRNA down-regulation over 80 percent. Western blot analysis confirmed mRNA measurements. No compensatory effect of IAP family members was seen in XIAP depleted cells. The sensitivity of XIAP depleted cells for TRAIL was highest in BDE cells with an increase in the ED50 of 14-fold, compared to mock- and nonsense-treated controls. The sensitivity of P114 and D17 cell-lines increased six- and five-fold, respectively. Doxorubicin treatment in XIAP depleted cells increased sensitivity in BDE cells more than eight-fold, whereas P114 and D17 cell-lines showed an increase in sensitivity of three- and five-fold, respectively. Conclusion XIAP directed siRNA's have a strong sensitizing effect on TRAIL-reduced cell-viability and a smaller but significant effect with the DNA damaging drug doxorubicin. The increase in efficacy of chemotherapeutics with XIAP depletion provides the rationale for the use of XIAP siRNA's in insensitive canine tumors. PMID:16953886

Mechanisms of insulin resistance in obesity

PubMed Central

Ye, Jianping

2014-01-01

Obesity increases the risk for type 2 diabetes through induction of insulin resistance. Treatment of type 2 diabetes has been limited by little translational knowledge of insulin resistance although there have been several well-documented hypotheses for insulin resistance. In those hypotheses, inflammation, mitochondrial dysfunction, hyperinsulinemia and lipotoxicity have been the major concepts and have received a lot of attention. Oxidative stress, endoplasmic reticulum (ER) stress, genetic background, aging, fatty liver, hypoxia and lipodystrophy are active subjects in the study of these concepts. However, none of those concepts or views has led to an effective therapy for type 2 diabetes. The reason is that there has been no consensus for a unifying mechanism of insulin resistance. In this review article, literature is critically analyzed and reinterpreted for a new energy-based concept of insulin resistance, in which insulin resistance is a result of energy surplus in cells. The energy surplus signal is mediated by ATP and sensed by adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. Decreasing ATP level by suppression of production or stimulation of utilization is a promising approach in the treatment of insulin resistance. In support, many of existing insulin sensitizing medicines inhibit ATP production in mitochondria. The effective therapies such as weight loss, exercise, and caloric restriction all reduce ATP in insulin sensitive cells. This new concept provides a unifying cellular and molecular mechanism of insulin resistance in obesity, which may apply to insulin resistance in aging and lipodystrophy. PMID:23471659

Effect of Iron Chelation Therapy on Glucose Metabolism in Non-Transfusion-Dependent Thalassaemia.

PubMed

Chuansumrit, Ampaiwan; Pengpis, Pimprae; Mahachoklertwattana, Pat; Sirachainan, Nongnuch; Poomthavorn, Preamrudee; Sungkarat, Witaya; Kadegasem, Praguywan; Khlairit, Patcharin; Wongwerawattanakoon, Pakawan

2017-01-01

To compare insulin sensitivity, β-cell function and iron status biomarkers in non-transfusion-dependent thalassaemia (NTDT) with iron excess during pre- and post-iron chelation. Subjects with NTDT, aged older than 10 years, with serum ferritin >300 ng/ml, were included. Iron chelation with deferasirox (10 mg/kg/day) was prescribed daily for 6 months. Ten patients with a median age of 17.4 years were enrolled. The comparison between pre- and post-chelation demonstrated significantly lower iron load: median serum ferritin (551.4 vs. 486.2 ng/ml, p = 0.047), median TIBC (211.5 vs. 233.5 µg/dl, p = 0.009) and median non-transferrin binding iron (5.5 vs. 1.4 µM, p = 0.005). All patients had a normal oral glucose tolerance test (OGTT) both pre- and post-chelation. However, fasting plasma glucose was significantly reduced after iron chelation (85.0 vs.79.5 mg/dl, p = 0.047). MRI revealed no significant changes of iron accumulation in the heart and liver after chelation, but there was a significantly lower iron load in the pancreas, assessed by higher T2* at post-chelation compared with pre-chelation (41.9 vs. 36.7 ms, p = 0.047). No adverse events were detected. A trend towards improving insulin sensitivity and β-cell function as well as a reduced pancreatic iron load was observed following 6 months of iron chelation (TCTR20160523003). © 2016 S. Karger AG, Basel.

Utility of quantitative sensory testing and screening tools in identifying HIV-associated peripheral neuropathy in Western Kenya: pilot testing.

PubMed

Cettomai, Deanna; Kwasa, Judith; Kendi, Caroline; Birbeck, Gretchen L; Price, Richard W; Bukusi, Elizabeth A; Cohen, Craig R; Meyer, Ana-Claire

2010-12-08

Neuropathy is the most common neurologic complication of HIV but is widely under-diagnosed in resource-constrained settings. We aimed to identify tools that accurately distinguish individuals with moderate/severe peripheral neuropathy and can be administered by non-physician healthcare workers (HCW) in resource-constrained settings. We enrolled a convenience sample of 30 HIV-infected outpatients from a Kenyan HIV-care clinic. A HCW administered the Neuropathy Severity Score (NSS), Single Question Neuropathy Screen (Single-QNS), Subjective Peripheral Neuropathy Screen (Subjective-PNS), and Brief Peripheral Neuropathy Screen (Brief-PNS). Monofilament, graduated tuning fork, and two-point discrimination examinations were performed. Tools were validated against a neurologist's clinical assessment of moderate/severe neuropathy. The sample was 57% male, mean age 38.6 years, and mean CD4 count 324 cells/µL. Neurologist's assessment identified 20% (6/30) with moderate/severe neuropathy. Diagnostic utilities for moderate/severe neuropathy were: Single-QNS--83% sensitivity, 71% specificity; Subjective-PNS-total--83% sensitivity, 83% specificity; Subjective-PNS-max and NSS--67% sensitivity, 92% specificity; Brief-PNS--0% sensitivity, 92% specificity; monofilament--100% sensitivity, 88% specificity; graduated tuning fork--83% sensitivity, 88% specificity; two-point discrimination--75% sensitivity, 58% specificity. Pilot testing suggests Single-QNS, Subjective-PNS, and monofilament examination accurately identify HIV-infected patients with moderate/severe neuropathy and may be useful diagnostic tools in resource-constrained settings.

INF-γ sensitizes head and neck squamous cell carcinoma cells to chemotherapy-induced apoptosis and necroptosis through up-regulation of Egr-1.

PubMed

Xu, Bei; Shu, Yongqian; Liu, Peng

2014-11-01

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Acquired resistance to standard chemotherapy accounts for most of treatment failure. Here we demonstrate that Interferon-γ (INF-γ) may up-regulate Egr-1 gene expression in HNSCC cell line SCC-25. Forced expression of Egr-1 sensitizes SCC-25 cells to chemotherapy-induced apoptosis and necroptosis, a novel form of programmed cell death. Egr-1 up-regulation also significantly increases the production of Thrombospondin-1 (TSP-1), a matricellular glycoprotein which has been described to induce cell death in HNSCC. Moreover, INF-γ-induced sensitization of cells to chemotherapy-mediated cell death and TSP-1 production could be markedly abolished by Egr-1 silencing. The present investigation provides the first evidence that INF-γ may sensitize HNSCC cells to chemotherapy-induced apoptosis and necroptosis through up-regulation of Egr-1. These data support the combination use of INF-γ and cytotoxic drugs for HNSCC Therapy.

In Vitro Detection of Characteristic Differences in Radiation Sensitivity of Female Genital Cancers

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

LUDOVICI, PETER P.; MILLER, NORMAN F.

1962-01-01

BS>By a standardized assay technic in which cell monolayers were irradiated at different dose levels (100 to 1200 r) on the 4th culture day and cell counts carried out 4 days later, the radiation sensitivities of 37 cell strains, derived from female patients with various genital cancers and from normal individuals, were assessed. These 37 cell strains had certain patterns of radiation sensitivity which, in general, appear to be consistent with the generally accepted radiosensitivity of the tumors from which the cell strains arose. Cell strains from squamous-cell carcinomas of the cervix as a group were at least twice asmore » sensitive as those from other squamous-cell carcinomas of the female genital tract. Cell strains derived from carcinomas of the ovary, vagina, and vulva were almost equally resistant to radiation. As expected, cell strains derived from benign tissues were the most highly resistant to radiation, normal fibroblastic strains being more resistant than normal epithelial strains. (H.H.D.)« less

Role of bone marrow cells in the growth inhibition of transplanted methylcholanthrene-induced sarcoma (MCA). [/sup 137/Cs

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

Scuderi, P.; Rosse, C.

1981-03-01

The operation of various antitumor mechanisms in vivo remains largely unknown. The presence of specific sensitized cells in the spleen and lymph node of tumor-bearing and tumor-immune animals has been demonstrated. Such cells are more effectively revealed by secondary sensitization of the splenocytes of tumor-immune animals in vitro by reexposing them to the tumor. Tumor-immune in vitro sensitized splenocytes (ISS) are highly effective in retarding the in vivo growth of the sensitizing tumor when they are transplated together with tumor cells into normal recipient mice. However, if the same cell transfer is made into lethally irradiated mice, the tumor willmore » grow rapidly in 100% of recipients. The objective of the present study is to explore this phenomenon and to determine the origin of the host cells that are capable of collaborating with tumor-immune in vitro sensitized splenocytes in the regulation of tumor growth. We designed experiments to test whether the host cells involved in tumor growth regulation are derived from the spleen, thymus, or the bone marrow and set out to determine whether or not collaboration of the host cells with ISS was specific as far as the sensitizing tumor was concerned.« less

High-efficiency dye-sensitized solar cells with ferrocene-based electrolytes.

PubMed

Daeneke, Torben; Kwon, Tae-Hyuk; Holmes, Andrew B; Duffy, Noel W; Bach, Udo; Spiccia, Leone

2011-03-01

Dye-sensitized solar cells based on iodide/triiodide (I(-)/I(3)(-)) electrolytes are viable low-cost alternatives to conventional silicon solar cells. However, as well as providing record efficiencies of up to 12.0%, the use of I(-)/I(3)(-) in such solar cells also brings about certain limitations that stem from its corrosive nature and complex two-electron redox chemistry. Alternative redox mediators have been investigated, but these generally fall well short of matching the performance of conventional I(-)/I(3)(-) electrolytes. Here, we report energy conversion efficiencies of 7.5% (simulated sunlight, AM1.5, 1,000 W m(-2)) for dye-sensitized solar cells combining the archetypal ferrocene/ferrocenium (Fc/Fc(+)) single-electron redox couple with a novel metal-free organic donor-acceptor sensitizer (Carbz-PAHTDTT). These Fc/Fc(+)-based devices exceed the efficiency achieved for devices prepared using I(-)/I(3)(-) electrolytes under comparable conditions, revealing the great potential of ferrocene-based electrolytes in future dye-sensitized solar cells applications. This improvement results from a more favourable matching of the redox potential of the ferrocene couple with that of the new donor-acceptor sensitizer.

Targeting protein-trafficking pathways alters melanoma treatment sensitivity

PubMed Central

Huang, Zhi-ming; Chinen, Milka; Chang, Philip J.; Xie, Tong; Zhong, Lily; Demetriou, Stephanie; Patel, Mira P.; Scherzer, Rebecca; Sviderskaya, Elena V.; Bennett, Dorothy C.; Millhauser, Glenn L.; Oh, Dennis H.; Cleaver, James E.; Wei, Maria L.

2012-01-01

Protein-trafficking pathways are targeted here in human melanoma cells using methods independent of oncogene mutational status, and the ability to up-regulate and down-regulate tumor treatment sensitivity is demonstrated. Sensitivity of melanoma cells to cis-diaminedichloroplatinum II (cDDP, cis-platin), carboplatin, dacarbazine, or temozolomide together with velaparib, an inhibitor of poly (ADP ribose) polymerase 1, is increased by up to 10-fold by targeting genes that regulate both protein trafficking and the formation of melanosomes, intracellular organelles unique to melanocytes and melanoma cells. Melanoma cells depleted of either of the protein-trafficking regulators vacuolar protein sorting 33A protein (VPS33A) or cappuccino protein (CNO) have increased nuclear localization of cDDP, increased nuclear DNA damage by platination, and increased apoptosis, resulting in increased treatment sensitivity. Depleted cells also exhibit a decreased proportion of intracellular, mature melanosomes compared with undepleted cells. Modulation of protein trafficking via cell-surface signaling by binding the melanocortin 1 receptor with the antagonist agouti-signaling protein decreased the proportion of mature melanosomes formed and increased cDDP sensitivity, whereas receptor binding with the agonist melanocyte-stimulating hormone resulted in an increased proportion of mature melanosomes formed and in decreased sensitivity (i.e., increased resistance) to cDDP. Mutation of the protein-trafficking gene Hps6, known to impair the formation of mature melanosomes, also increased cDDP sensitivity. Together, these results indicate that targeting protein-trafficking molecules markedly increases melanoma treatment sensitivity and influences the degree of melanosomes available for sequestration of therapeutic agents. PMID:22203954

Effects of hydroquinone on retinal and vascular cells in vitro

PubMed Central

Sharma, Ashish; Patil, Jayaprakash A; Gramajo, Ana L; Seigel, Gail M; Kuppermann, Baruch D; Kenney, Cristina M

2012-01-01

Aim: To explore the molecular pathophysiology that might explain the epidemiologic association between cigarette smoke and age-related macular degeneration (AMD) by examining the effects of hydroquinone (HQ), a toxic compound present in high concentration in cigarette smoke-related tar, on human retinal pigment epithelial cells (ARPE-19), rat retinal neurosensory cells (R-28), and human microvascular endothelial cells (HMVEC). Materials and Methods: ARPE-19, R-28, and HMVEC were treated for 24 h with four different concentrations of HQ (500 μM, 200 μM, 100 μM, 50 μM). Cell viability, caspase-3/7 activation, DNA laddering patterns, and lactate dehydrogenase (LDH) levels were analyzed. Results: At 50 μM HQ, R-28 cells showed a significant decrease in cell viability compared with the dimethyl sulfoxide (DMSO)-treated controls. At the 100–500 μM concentrations, all three cell lines showed significant cell death (P < 0.001). In the ARPE-19, R-28, and HMVEC cultures, the caspase-3/7 activities were not increased at any of the HQ concentration. Conclusion: Our findings suggest that the mechanism of cell death in all three cell lines was through non-apoptotic pathway. In addition, neuroretinal R-28 cells were more sensitive to HQ than the ARPE-19 and HMVEC cultures. PMID:22569379

Application of recombinant fluorescent mammalian cells as a toxicity biosensor.

PubMed

Kim, E J; Lee, Y; Lee, J E; Gu, M B

2002-01-01

With respect to developing a more sensitive biosensor, a recombinant fluorescent Chinese Hamster Ovary cell line was used for the monitoring of various toxicants. Both cell lines, EFC-500 and KFC-A10, were able to detect toxicants sensitively. They were characterized with mitomycin C and gamma-ray as genotoxicants and bisphenol A, nonylphenol, ziram and methyl bromide as possible and known EDCs. When compared to each other, the response of KFC-A10 was generally more informative and sensitive. Compared to typical bacterial biosensor systems, these cell lines offered a sensitivity of 2- to 50-fold greater for the tested chemicals. Based on these results, the use of mammalian cells offers a sensitive biosensor system that is not only fast, cheap and reproducible but also capable of monitoring the endocrine-like characteristics of environmental toxicants.

Electrical characterization of dye sensitized nano solar cell using natural pomegranate juice as photosensitizer

NASA Astrophysics Data System (ADS)

Adithi, U.; Thomas, Sara; Uma, V.; Pradeep, N.

2013-02-01

This paper shows Electrical characterization of Dye Sensitized Solar Cell using natural dye, extracted from the pomegranate as a photo sensitizer and ZnO nanoparticles as semiconductor. The constituents of fabricated dye sensitized solar cell were working electrode, dye, electrolyte and counter electrode. ZnO nanoparticles were synthesized and used as semiconductor in working electrode. Carbon soot was used as counter electrode. The resistance of ZnO film on ITO film was found out. There was an increase in the resistance of the film and film changes from conducting to semiconducting. Photovoltaic parameters of the fabricated cell like Short circuit current, open circuit voltage, Fill factor and Efficiency were found out. This paper shows that usage of natural dyes like pomegranate juice as sensitizer enables faster and simpler production of cheaper and environmental friendly solar cell.

Immunohistochemical Evaluation of Androgen Receptor and Nerve Structure Density in Human Prepuce from Patients with Persistent Sexual Side Effects after Finasteride Use for Androgenetic Alopecia

PubMed Central

Di Loreto, Carla; La Marra, Francesco; Mazzon, Giorgio; Belgrano, Emanuele; Trombetta, Carlo; Cauci, Sabina

2014-01-01

Finasteride is an inhibitor of 5-α-reductase used against male androgenetic alopecia (AGA). Reported side effects of finasteride comprise sexual dysfunction including erectile dysfunction, male infertility, and loss of libido. Recently these effects were described as persistent in some subjects. Molecular events inducing persistent adverse sexual symptoms are unexplored. This study was designed as a retrospective case-control study to assess if androgen receptor (AR) and nerve density in foreskin prepuce specimens were associated with persistent sexual side effects including loss of sensitivity in the genital area due to former finasteride use against AGA. Cases were 8 males (aged 29–43 years) reporting sexual side effects including loss of penis sensitivity over 6 months after discontinuation of finasteride who were interviewed and clinically visited. After informed consent they were invited to undergo a small excision of skin from prepuce. Controls were 11 otherwise healthy matched men (aged 23–49 years) who undergone circumcision for phimosis, and who never took finasteride or analogues. Differences in AR expression and nerve density in different portions of dermal prepuce were evaluated in the 2 groups. Density of nuclear AR in stromal and epithelial cells was higher in cases (mean 40.0%, and 80.6% of positive cells, respectively) than controls (mean 23.4%, and 65.0% of positive cells, respectively), P = 0.023 and P = 0.043, respectively. Conversely, percentage of vessel smooth muscle cells positive for AR and density of nerves were similar in the 2 groups. The ratio of AR positive stromal cells % to serum testosterone concentrations was 2-fold higher in cases than in controls (P = 0.001). Our findings revealed that modulation of local AR levels might be implicated in long-term side effects of finasteride use. This provides the first evidence of a molecular objective difference between patients with long-term adverse sexual effects after finasteride use versus drug untreated healthy controls in certain tissues. PMID:24959691

Alginate foam-based three-dimensional culture to investigate drug sensitivity in primary leukaemia cells.

PubMed

Karimpoor, Mahroo; Yebra-Fernandez, Eva; Parhizkar, Maryam; Orlu, Mine; Craig, Duncan; Khorashad, Jamshid S; Edirisinghe, Mohan

2018-04-01

The development of assays for evaluating the sensitivity of leukaemia cells to anti-cancer agents is becoming an important aspect of personalized medicine. Conventional cell cultures lack the three-dimensional (3D) structure of the bone marrow (BM), the extracellular matrix and stromal components which are crucial for the growth and survival of leukaemia stem cells. To accurately predict the sensitivity of the leukaemia cells in an in vitro assay a culturing system containing the essential components of BM is required. In this study, we developed a porous calcium alginate foam-based scaffold to be used for 3D culture. The new 3D culture was shown to be cell compatible as it supported the proliferation of both normal haematopoietic and leukaemia cells. Our cell differential assay for myeloid markers showed that the porous foam-based 3D culture enhanced myeloid differentiation in both leukaemia and normal haematopoietic cells compared to two-dimensional culture. The foam-based scaffold reduced the sensitivity of the leukaemia cells to the tested antileukaemia agents in K562 and HL60 leukaemia cell line model and also primary myeloid leukaemia cells. This observation supports the application of calcium alginate foams as scaffold components of the 3D cultures for investigation of sensitivity to antileukaemia agents in primary myeloid cells. © 2018 The Author(s).

Heteromeric Slick/Slack K+ channels show graded sensitivity to cell volume changes

PubMed Central

Hashem, Nadia; Calloe, Kirstine; Klaerke, Dan A.

2017-01-01

Slick and Slack high-conductance K+ channels are found in the CNS, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. They are both activated by Na+ and Cl- but show a differential regulation by cell volume changes. Slick has been shown to be regulated by cell volume changes, whereas Slack is insensitive. α-subunits of these channels form homomeric as well as heteromeric channels. It is the aim of this work to explore whether the subunit composition of the Slick/Slack heteromeric channel affects the response to osmotic challenges. In order to provide with the adequate water permeability to the cell membrane of Xenopus laevis oocytes, mRNA of aquaporin 1 was co-expressed with homomeric or heteromeric Slick and Slack α-subunits. Oocytes were superfused with hypotonic or hypertonic buffers and changes in currents were measured by two-electrode voltage clamp. This work presents the first heteromeric K+ channel with a characteristic graded sensitivity to small and fast changes in cell volume. Our results show that the cell volume sensitivity of Slick/Slack heteromeric channels is dependent on the number of volume sensitive Slick α-subunits in the tetrameric channels, giving rise to graded cell volume sensitivity. Regulation of the subunit composition of a channel may constitute a novel mechanism to determine volume sensitivity of cells. PMID:28222129

Heteromeric Slick/Slack K+ channels show graded sensitivity to cell volume changes.

PubMed

Tejada, Maria A; Hashem, Nadia; Calloe, Kirstine; Klaerke, Dan A

2017-01-01

Slick and Slack high-conductance K+ channels are found in the CNS, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. They are both activated by Na+ and Cl- but show a differential regulation by cell volume changes. Slick has been shown to be regulated by cell volume changes, whereas Slack is insensitive. α-subunits of these channels form homomeric as well as heteromeric channels. It is the aim of this work to explore whether the subunit composition of the Slick/Slack heteromeric channel affects the response to osmotic challenges. In order to provide with the adequate water permeability to the cell membrane of Xenopus laevis oocytes, mRNA of aquaporin 1 was co-expressed with homomeric or heteromeric Slick and Slack α-subunits. Oocytes were superfused with hypotonic or hypertonic buffers and changes in currents were measured by two-electrode voltage clamp. This work presents the first heteromeric K+ channel with a characteristic graded sensitivity to small and fast changes in cell volume. Our results show that the cell volume sensitivity of Slick/Slack heteromeric channels is dependent on the number of volume sensitive Slick α-subunits in the tetrameric channels, giving rise to graded cell volume sensitivity. Regulation of the subunit composition of a channel may constitute a novel mechanism to determine volume sensitivity of cells.

Aptamer-aided target capturing with biocatalytic metal deposition: an electrochemical platform for sensitive detection of cancer cells.

PubMed

Yi, Zi; Li, Xiao-Yan; Gao, Qing; Tang, Li-Juan; Chu, Xia

2013-04-07

A novel aptamer biosensor for cancer cell assay has been reported on the basis of ultrasensitive electrochemical detection. Cancer cell capturing is first accomplished via aptamer-aided recognition, and the cell-aptamer binding events then mediate an alkaline phosphatase-catalyzed silver deposition reaction which can be probed by electrochemical detection. Following biocatalytic silver deposition, an efficient amplification approach for sensitive electrochemical measurements is demonstrated, for cell detection with high sensitivity. Ramos cell are used as a model case, a typical biomarker of the acute blood cell cancer, Burkitt's lymphoma. The results reveal that the developed technique displays desirable selectivity in Ramos cell discrimination, and linear response range from 10 to 10(6) cells with a detection limit as low as 10 cells. Due to the simple procedures, label-free and electrochemistry based detection format, this technique is simple and cost-effective, and exhibits excellent compatibility with miniaturization technologies. The electrochemical cell detection strategy may create an intrinsically specific and sensitive platform for cancer cell assay and associated studies.

Interleukin-4-dependent innate collaboration between iNKT cells and B-1 B cells controls adaptative contact sensitivity

PubMed Central

Campos, Regis A; Szczepanik, Marian; Itakura, Atsuko; Lisbonne, Mariette; Dey, Neelendu; Leite-de-Moraes, Maria C; Askenase, Philip W

2006-01-01

We showed that hepatic Vα14+ invariant natural killer T (iNKT) cells, via their rapid interleukin (IL)-4 production, activate B-1 cells to initiate contact sensitivity (CS). This innate collaboration was absent in IL-4–/– and signal transducer and activator of transcription (STAT)-6–/– mice and was inhibited by anti-IL-4 treatment. These mice have defective CS because they fail to locally recruit the sensitized effector T cells of acquired immunity. Their CS is reconstituted by transfer of downstream-acting 1-day immune B-1 cells from wild-type mice. Responses were not reconstituted with B-1 cells from IL-4 receptor-α–/– or STAT-6–/– mice, nor by IL-4 treatment of B cell-deficient mice at immunization. Finally, IL-4 was preferentially and transiently produced by hepatic iNKT cells within 7 min after sensitization to mediate collaboration between innate-like iNKT cells and the B-1 B cells that participate in the recruitment of effector T cells in vivo. PMID:16556268

Involvement of the DNA mismatch repair system in cisplatin sensitivity of testicular germ cell tumours.

PubMed

Rudolph, Christiane; Melau, Cecilie; Nielsen, John E; Vile Jensen, Kristina; Liu, Dekang; Pena-Diaz, Javier; Rajpert-De Meyts, Ewa; Rasmussen, Lene Juel; Jørgensen, Anne

2017-08-01

Testicular germ cell tumours (TGCT) are highly sensitive to cisplatin-based chemotherapy, but patients with tumours containing differentiated teratoma components are less responsive to this treatment. The cisplatin sensitivity in TGCT has previously been linked to the embryonic phenotype in the majority of tumours, although the underlying mechanism largely remains to be elucidated. The aim of this study was to investigate the role of the DNA mismatch repair (MMR) system in the cisplatin sensitivity of TGCT. The expression pattern of key MMR proteins, including MSH2, MSH6, MLH1 and PMS2, were investigated during testis development and in the pathogenesis of TGCT, including germ cell neoplasia in situ (GCNIS). The TGCT-derived cell line NTera2 was differentiated using retinoic acid (10 μM, 6 days) after which MMR protein expression and activity, as well as cisplatin sensitivity, were investigated in both undifferentiated and differentiated cells. Finally, the expression of MSH2 was knocked down by siRNA in NTera2 cells after which the effect on cisplatin sensitivity was examined. MMR proteins were expressed in proliferating cells in the testes, while in malignant germ cells MMR protein expression was found to coincide with the expression of the pluripotency factor OCT4, with no or low expression in the more differentiated yolk sac tumours, choriocarcinomas and teratomas. In differentiated NTera2 cells we found a significantly (p < 0.05) lower expression of the MMR and pluripotency factors, as well as a reduced MMR activity and cisplatin sensitivity, compared to undifferentiated NTera2 cells. Also, we found that partial knockdown of MSH2 expression in undifferentiated NTera2 cells resulted in a significantly (p < 0.001) reduced cisplatin sensitivity. This study reports, for the first time, expression of the MMR system in fetal gonocytes, from which GCNIS cells are derived. Our findings in primary TGCT specimens and TGCT-derived cells suggest that a reduced sensitivity to cisplatin in differentiated TGCT components could result from a reduced expression of MMR proteins, in particular MSH2 and MLH1, which are involved in the recognition of cisplatin adducts and in activation of the DNA damage response pathway to initiate apoptosis.

Proliferation inhibitory effect of human alpha interferon on primary explants of Burkitt lymphoma: inverse relationship to patient survival.

PubMed

Ernberg, I; Einhorn, S; Strander, H; Klein, G

1981-11-01

Eleven biopsies from 9 patients with Burkitt's lymphoma were tested for their sensitivity to the cell multiplication inhibitory activity of interferon. Three were resistant to interferon while 8 were sensitive to various degrees. Different biopsies from the same patient did not differ in interferon sensitivity. These results indicate that Burkitt's lymphoma cells might be resistant to interferon already in vivo as previously shown for some derived cell lines tested in vitro. The results imply an inverse relationship between patient survival and interferon sensitivity of the tumor cells.

Changes in subcutaneous fat cell volume and insulin sensitivity after weight loss.

PubMed

Andersson, Daniel P; Eriksson Hogling, Daniel; Thorell, Anders; Toft, Eva; Qvisth, Veronica; Näslund, Erik; Thörne, Anders; Wirén, Mikael; Löfgren, Patrik; Hoffstedt, Johan; Dahlman, Ingrid; Mejhert, Niklas; Rydén, Mikael; Arner, Erik; Arner, Peter

2014-07-01

Large subcutaneous fat cells associate with insulin resistance and high risk of developing type 2 diabetes. We investigated if changes in fat cell volume and fat mass correlate with improvements in the metabolic risk profile after bariatric surgery in obese patients. Fat cell volume and number were measured in abdominal subcutaneous adipose tissue in 62 obese women before and 2 years after Roux-en-Y gastric bypass (RYGB). Regional body fat mass by dual-energy X-ray absorptiometry; insulin sensitivity by hyperinsulinemic-euglycemic clamp; and plasma glucose, insulin, and lipid profile were assessed. RYGB decreased body weight by 33%, which was accompanied by decreased adipocyte volume but not number. Fat mass in the measured regions decreased and all metabolic parameters were improved after RYGB (P < 0.0001). Whereas reduced subcutaneous fat cell size correlated strongly with improved insulin sensitivity (P = 0.0057), regional changes in fat mass did not, except for a weak correlation between changes in visceral fat mass and insulin sensitivity and triglycerides. The curve-linear relationship between fat cell size and fat mass was altered after weight loss (P = 0.03). After bariatric surgery in obese women, a reduction in subcutaneous fat cell volume associates more strongly with improvement of insulin sensitivity than fat mass reduction per se. An altered relationship between adipocyte size and fat mass may be important for improving insulin sensitivity after weight loss. Fat cell size reduction could constitute a target to improve insulin sensitivity. © 2014 by the American Diabetes Association.

ATR inhibition broadly sensitizes ovarian cancer cells to chemotherapy independent of BRCA status

PubMed Central

Huntoon, Catherine J.; Flatten, Karen S.; Wahner Hendrickson, Andrea E.; Huehls, Amelia M.; Sutor, Shari L.; Kaufmann, Scott H.; Karnitz, Larry M.

2013-01-01

Replication stress and DNA damage activate the ATR-CHK1 checkpoint signaling pathway that licenses repair and cell survival processes. In this study, we examined the respective roles of the ATR and CHK1 kinases in ovarian cancer cells using genetic and pharmacological inhibitors of in combination with cisplatin, topotecan, gemcitabine and the poly(ADP-ribose)-polymerase (PARP) inhibitor veliparib (ABT-888), four agents with clinical activity in ovarian cancer. RNAi-mediated depletion or inhibition of ATR sensitized ovarian cancer cells to all four agents. In contrast, while cisplatin, topotecan and gemcitabine each activated CHK1, RNAi-mediated depletion or inhibition of this kinase in cells sensitized them only to gemcitabine. Unexpectedly, we found that neither the ATR kinase inhibitor VE-821 or the CHK1 inhibitor MK-8776 blocked ATR-mediated CHK1 phosphorylation or autophosphorylation, two commonly used readouts for inhibition of the ATR-CHK1 pathway. Instead, their ability to sensitize cells correlated with enhanced CDC25A levels. Additionally, we also found that VE-821 could further sensitize BRCA1-depleted cells to cisplatin, topotecan and veliparib beyond the potent sensitization already caused by their deficiency in homologous recombination. Taken together, our results established that ATR and CHK1 inhibitors differentially sensitize ovarian cancer cells to commonly used chemotherapy agents, and that CHK1 phosphorylation status may not offer a reliable marker for inhibition of the ATR-CHK1 pathway. A key implication of our work is the clinical rationale it provides to evaluate ATR inhibitors in combination with PARP inhibitors in BRCA1/2-deficient cells. PMID:23548269

THP-1 monocytes but not macrophages as a potential alternative for CD34{sup +} dendritic cells to identify chemical skin sensitizers

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

Lambrechts, Nathalie; Verstraelen, Sandra; Lodewyckx, Hanne

2009-04-15

Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34{sup +} progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expressionmore » profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (L-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After a cross-validation of a discriminant analysis of the gene expression profiles in the THP-1 monocytes, this cell model demonstrated to also have a capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals.« less

Enhanced photovoltaic performance of a quantum dot-sensitized solar cell using a Nb-doped TiO2 electrode.

PubMed

Jiang, Lei; You, Ting; Deng, Wei-Qiao

2013-10-18

In this work Nb-doped anatase TiO2 nanocrystals are used as the photoanode of quantum-dot-sensitized solar cells. A solar cell with CdS/CdSe quantum dots co-sensitized 2.5 mol% Nb-doped anatase TiO2 nanocrystals can achieve a photovoltaic conversion efficiency of 3.3%, which is almost twice as high as the 1.7% obtained by a cell based on undoped TiO2 nanocrystals. The incident photon-to-current conversion efficiency can reach as high as 91%, which is a record for all quantum-dot-sensitized solar cells. Detailed analysis shows that such an enhancement is due to improved lifetime and diffusion length of electrons in the solar cell.

Development of an in vitro skin sensitization test based on ROS production in THP-1 cells.

PubMed

Saito, Kazutoshi; Miyazawa, Masaaki; Nukada, Yuko; Sakaguchi, Hitoshi; Nishiyama, Naohiro

2013-03-01

Recently, it has been reported that reactive oxygen species (ROS) produced by contact allergens can affect dendritic cell migration and contact hypersensitivity. The aim of the present study was to develop a new in vitro assay that could predict the skin sensitizing potential of chemicals by measuring ROS production in THP-1 (human monocytic leukemia cell line) cells. THP-1 cells were pre-loaded with a ROS sensitive fluorescent dye, 5-(and 6-)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), for 15min, then incubated with test chemicals for 30min. The fluorescence intensity was measured by flow cytometry. For the skin sensitizers, 25 out of 30 induced over a 2-fold ROS production at more than 90% of cell viability. In contrast, increases were only seen in 4 out of 20 non-sensitizers. The overall accuracy for the local lymph node assay (LLNA) was 82% for 50 chemicals tested. A correlation was found between the estimated concentration showing 2-fold ROS production in the ROS assay and the EC3 values (estimated concentration required to induce positive response) of the LLNA. These results indicated that the THP-1 cell-based ROS assay was a rapid and highly sensitive detection system able to predict skin sensitizing potentials and potency of chemicals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Reduced DIDS-sensitive chloride conductance in Ae1-/- mouse erythrocytes

PubMed Central

Alper, Seth L.; Vandorpe, David H.; Peters, Luanne L.; Brugnara, Carlo

2008-01-01

The resting membrane potential of the human erythrocyte is largely determined by a constitutive Cl- conductance ∼100-fold greater than the resting cation conductance. The 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS)-sensitive electroneutral Cl- transport mediated by the human erythroid Cl-/HCO3- exchanger, AE1 (SLC4A1, band 3) is ≥10,000-fold greater than can be accounted for by the Cl- conductance of the red cell. The molecular identities of conductive anion pathways across the red cell membrane remain poorly defined. We have examined red cell Cl- conductance in the Ae1-/- mouse as a genetic test of the hypothesis that Ae1 mediates DIDS-sensitive Cl- conductance in mouse red cells. We report here that wildtype mouse red cell membrane potential resembles that of human red cells in the predominance of its Cl- conductance. We show with four technical approaches that the DIDS-sensitive component of erythroid Cl- conductance is reduced or absent from Ae1-/- red cells. These results are consistent with the hypothesis that the Ae1 anion exchanger polypeptide can operate infrequently in a conductive mode. However, the fragile red cell membrane of the Ae1-/- mouse red cell exhibits reduced abundance or loss of multiple polypeptides. Thus, loss of one or more distinct, DIDS-sensitive anion channel polypeptide(s) from the Ae1-/- red cell membrane cannot be ruled out as an explanation for the reduced DIDS-sensitive anion conductance. PMID:18329299

Characterization of glioma stem cells through multiple stem cell markers and their specific sensitization to double-strand break-inducing agents by pharmacological inhibition of ataxia telangiectasia mutated protein.

PubMed

Raso, Alessandro; Vecchio, Donatella; Cappelli, Enrico; Ropolo, Monica; Poggi, Alessandro; Nozza, Paolo; Biassoni, Roberto; Mascelli, Samantha; Capra, Valeria; Kalfas, Fotios; Severi, Paolo; Frosina, Guido

2012-09-01

Previous studies have shown that tumor-driving glioma stem cells (GSC) may promote radio-resistance by constitutive activation of the DNA damage response started by the ataxia telangiectasia mutated (ATM) protein. We have investigated whether GSC may be specifically sensitized to ionizing radiation by inhibiting the DNA damage response. Two grade IV glioma cell lines (BORRU and DR177) were characterized for a number of immunocytochemical, karyotypic, proliferative and differentiative parameters. In particular, the expression of a panel of nine stem cell markers was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. Overall, BORRU and DR177 displayed pronounced and poor stem phenotypes, respectively. In order to improve the therapeutic efficacy of radiation on GSC, the cells were preincubated with a nontoxic concentration of the ATM inhibitors KU-55933 and KU-60019 and then irradiated. BORRU cells were sensitized to radiation and radio-mimetic chemicals by ATM inhibitors whereas DR177 were protected under the same conditions. No sensitization was observed after cell differentiation or to drugs unable to induce double-strand breaks (DSB), indicating that ATM inhibitors specifically sensitize glioma cells possessing stem phenotype to DSB-inducing agents. In conclusion, pharmacological inhibition of ATM may specifically sensitize GSC to DSB-inducing agents while sparing nonstem cells. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

Insulin receptor substrate 1 expression enhances the sensitivity of 32D cells to chemotherapy-induced cell death

PubMed Central

Porter, Holly A.; Carey, Gregory B.; Keegan, Achsah D.

2012-01-01

The adaptors IRS1 and IRS2 link growth factor receptors to downstream signaling pathways that regulate proliferation and survival. Both suppress factor-withdrawal-induced apoptosis and have been implicated in cancer progression. However, recent studies suggest IRS1 and IRS2 mediate differential functions in cancer pathogenesis. IRS1 promoted breast cancer proliferation, while IRS2 promoted metastasis. The role of IRS1 and IRS2 in controlling cell responses to chemotherapy is unknown. To determine the role of IRS1 and IRS2 in the sensitivity of cells to chemotherapy, we treated 32D cells lacking or expressing IRS proteins with various concentrations of chemotherapeutic agents. We found that expression of IRS1, in contrast to IRS2, enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. When IRS2 was expressed with IRS1, the cells no longer showed enhanced sensitivity. Expression of IRS1 did not alter the expression of pro- and anti-apoptotic proteins; however, 32D-IRS1 cells expressed higher levels of Annexin A2. In 32D-IRS1 cells, IRS1 and Annexin A2 were both located in cytoplasmic and membrane fractions. We also found that IRS1 coprecipitated with Annexin A2, while IRS2 did not. Decreasing Annexin A2 levels reduced 32D-IRS1 cell sensitivity to chemotherapy. These results suggest IRS1 enhances sensitivity to chemotherapy in part through Annexin A2. PMID:22652453

Improved Cell Sensitivity and Longevity in a Rapid Impedance-based Toxicity Sensor

DTIC Science & Technology

2009-01-06

sensitivity and longevity in a rapid impedance-based toxicity sensor† Improved cell sensitivity and longevityTheresa M. Curtis,a** Joel Tabb,a Lori...Romeo,a Steven J. Schwager,b Mark W. Widderc* and William H. van der Schaliec ABSTRACT: A number of toxicity sensors for testing field water using a...range of eukaryotic cell types have been proposed, but it has been difficult to identify sensors with both appropriate sensitivity to toxicants and the

Changes in functional properties of the caffeine-sensitive Ca2+ store during differentiation of human SH-SY5Y neuroblastoma cells.

PubMed

Riddoch, Fiona C; Brown, Anna M; Rowbotham, Sophie E; Redfern, Christopher P F; Cheek, Timothy R

2007-03-01

We have used single cell fluorescence imaging techniques to examine how functional properties of the caffeine-sensitive Ca(2+) store change during differentiation of a sub-population of caffeine-sensitive SH-SY5Y cells. Application of caffeine (30 mM) 1-10.5 min after a 'priming' depolarisation pulse of 55 mM K(+) revealed that the caffeine-sensitive store in undifferentiated cells remained replete, whereas that in 9-cis retinoic acid (9cRA)-differentiated cells spontaneously dissipated with a t(1/2) of 2.8 min, and was essentially completely depleted approximately 10 min after priming. In 9cRA-differentiated cells that were stimulated with methacholine (10 microM) 1 min after priming, the amplitude, rate of rise and propagation velocity of the Ca(2+) wave in the neurites were all constant, whereas these kinetic parameters all progressively decreased as the wave travelled along the neurites in cells that were stimulated 10 min after priming. Use-dependent block with ryanodine inhibited the global Ca(2+) signal in 9cRA-differentiated cells stimulated with methacholine 1 min after priming (71+/-8%) but not 10 min after priming. Depolarisation was more effective at priming the caffeine-sensitive Ca(2+) store in 9cRA-differentiated cells, which lack a functional store-operated Ca(2+) entry pathway. We conclude that differentiation of caffeine-sensitive SH-SY5Y cells is accompanied by an increase in lability of the caffeine-sensitive Ca(2+) store, and that spontaneous dissipation of Ca(2+) from the store limits the time course of its molecular 'memory' during which it can amplify the hormone-induced Ca(2+) signal by Ca(2+)-induced Ca(2+) release.

Dim-light sensitivity of cells in the awake cat's lateral geniculate and medial interlaminar nuclei: a correlation with behavior.

PubMed

Kang, Incheol; Malpeli, Joseph G

2009-08-01

Contrast thresholds of cells in the dorsal lateral geniculate (LGNd) and medial interlaminar (MIN) nuclei of awake cats were measured for scotopic and mesopic vision with drifting sine gratings (1/8, 2, and 4 cycles/deg [cpd]; 4-Hz temporal frequency). Thresholds for mean firing rate (F0) and temporally modulated responses (F1) were derived with receiver-operating-characteristic analyses and compared with behavioral measures recently reported by Kang and colleagues. Behavioral sensitivity was predicted by the neural responses of the most sensitive combinations of cell class and response mode: Y-cell F1 responses for 1/8 cpd, X-cell F1 responses for 2 cpd, and Y-cell F0 responses for 4 cpd. All previous estimates of neural scotopic increment thresholds in animal models fell between Weber's law (proportional to retinal illuminance) and the deVries-Rose law (proportional to the square root of illuminance). However, psychophysical experiments suggest that under appropriate conditions human scotopic vision follows the deVries-Rose law. If behavioral sensitivity is assumed to be determined by the most sensitive class of cells, this discrepancy is resolved. Under scotopic conditions, off-center Y cells were the most sensitive and these followed the deVries-Rose law fairly closely. MIN Y cells were, on average, 0.25 log units more sensitive than LGNd Y cells under scotopic conditions, supporting a previous proposal that the MIN is a specialization of the carnivore for dim-light vision. We conclude that both physiologically and behaviorally, cat and human scotopic vision are fundamentally similar, including adherence to the deVries-Rose law for detection of Gabor functions.

Genetic influence on contrast sensitivity in middle-aged male twins.

PubMed

Cronin-Golomb, Alice; Panizzon, Matthew S; Lyons, Michael J; Franz, Carol E; Grant, Michael D; Jacobson, Kristen C; Eisen, Seth A; Laudate, Thomas M; Kremen, William S

2007-07-01

Contrast sensitivity is strongly associated with daily functioning among older adults, but the genetic and environmental contributions to this ability are unknown. Using the classical twin method, we addressed this issue by examining contrast sensitivity at five spatial frequencies (1.5-18 cycles per degree) in 718 middle-aged male twins from the Vietnam Era Twin Study of Aging (VETSA). Heritability estimates were modest (14-38%), whereas individual-specific environmental influences accounted for 62-86% of the variance. Identifying the types of individual-specific events that impact contrast sensitivity may suggest interventions to modulate this ability and thereby improve overall quality of life as adults age.

Exploring the Health Needs of Aging LGBT Adults in the Cape Fear Region of North Carolina.

PubMed

Rowan, Noell L; Beyer, Kelsey

2017-01-01

This study explored issues of culturally sensitive healthcare practice and needs among lesbian, gay, bisexual and transgender aging adults in coastal North Carolina. Survey data results indicated the largest problem was a history of verbally harassment and need for culturally sensitive healthcare. In conclusion, culturally sensitive interventions are needed to address the health disparities and unique needs of LGBT aging adults. Cultural sensitivity training for service providers is suggested as a vital step in addressing health disparities of aging LGBT adults. Implications for research include further exploration of health related needs of these often hidden and underserved population groups.

Laboratory aspects of asymptomatic bacteriuria in pregnancy.

PubMed

Mohammad, Marlyn; Mahdy, Zaleha A; Omar, Jamil; Maan, Noorashikin; Jamil, M A

2002-09-01

A total of 1,661 pregnant women aged between 13 and 45 years were screened for bacteriuria by urine culture. Of the 1,661 culture results, 615 (37%) yielded no growth; 728 (43.8%) yielded no significant growth (presence of <10(5) organisms/ml urine of one or more types of bacteria); 286 (17.2%) yielded mixed growth (presence of >10(5) organisms/ml urine of more than one type of bacteria) and only 32 (1.9%) showed significant growth (presence of >10(5) organisms/ml urine of a single bacterium). Urine microscopy was also conducted. Two hundred and twenty-four (13.5%) specimens had >10 white blood cells/ml urine, of which 66 had >100 white blood cells; 13 were from the significant growth group. Three hundred and seventy-four (22.5%) specimens showed the presence of bacteria, 42 (2.5%) had red blood cells, 370 (22.3%) had epithelial cells, 58 (3.5%) had crystals, and 14 (0.8%) had yeasts. The most common bacterium isolated was Escherichia coli (12; 40%); the others included group B Streptococcus (5; 15%), Klebsiella spp (5; 15%), Diphtheroids (2), and Candida albicans (2). Fifty-two percent of tested strains were sensitive to ampicillin; 24 of 28 strains (85.7%) were sensitive to ciprofloxacin; all 7 strains tested were sensitive to nitrofurantoin and all 20 strains tested were sensitive to cotrimoxazole; 14/20 (70%) and 16/17 (94.1%) were sensitive to cephalexin and cefuroxime respectively. This study shows that asymptomatic bacteriuria does occur in pregnant women, albeit at a very low rate in an urban setting like Cheras. Urine microscopy is not specific and only serves as a guide to bacteriuria. The commonest causative organisms are those from the gastrointestinal tract and vagina. The antibiogram showed that cefuroxime and cephalexin are likely to be effective in treating bacteriuria: ampicillin must be reserved for Gram-negative organisms. For Gram-positive organisms, of which Group B Streptococcus is important, ampicillin is still effective in vitro. Nitrofurantion and cotrimoxazole have excellent activity in vitro and should be considered for therapy. 17.2% of the urine culture yielded mixed growth: likely to indicate that contamination of urine specimens still happens despite the strict instructions given to patients about the collection of a midstream urine specimen. Proper collection, appropriate transport, and the early processing of urine specimens remain essential.

Efficient iodine-free dye-sensitized solar cells employing truxene-based organic dyes.

PubMed

Zong, Xueping; Liang, Mao; Chen, Tao; Jia, Jiangnan; Wang, Lina; Sun, Zhe; Xue, Song

2012-07-07

Two new truxene-based organic sensitizers (M15 and M16) featuring high extinction coefficients were synthesized for dye-sensitized solar cells employing cobalt electrolyte. The M16-sensitized device displays a 7.6% efficiency at an irradiation of AM1.5 full sunlight.

Effect of culture age on 1,3-dinitrobenzene metabolism and indicators of cellular toxicity in rat testicular cells.

PubMed

Brown, C D; Miller, M G

1991-01-01

The metabolism and toxicity of 1,3-dinitrobenzene(1,3-DNB) were examined in rat testicular cells that had been cultured for various amounts of time. The three cell systems utilized were: freshly isolated suspensions of Sertoli/germ cells; the same Sertoli/germ cells co-cultured for 24 hr; and Sertoli cell-enriched monolayers derived from the co-cultures and cultured for 96 hr. Indicators of toxicity were MTT reduction, neutral red incorporation, cellular ATP levels and lactate secretion into the media. 1,3-DNB (5-50 mum) caused a significant concentration-dependent decline in cellular ATP levels in the fresh cell suspension, but not in the cells that had been cultured for longer. No changes were observed either in MTT reduction or neutral red incorporation. Increased secretion of lactate into the media also did not prove to be a sensitive indicator of toxicity. Interestingly, 1,3-DNB metabolism to nitroaniline, nitroacetanilide and a covalently bound species was two to three times greater in the fresh cells, compared with either the 24- or 96-hr cell cultures. The data indicate that time in culture may have significant effects on both the capacity of testicular cells to metabolize 1,3-DNB and susceptibility to toxicity.

Deterioration of the useful visual field with age and sleep deprivation: insight from signal detection theory.

PubMed

Rogé, Joceline; Gabaude, Catherine

2009-08-01

The goal of this study was to establish whether the deterioration of the useful visual field due to sleep deprivation and age in a screen monitoring activity could be explained by a decrease in perceptual sensitivity and/or a modification of the participant's decision criterion (two indices derived from signal detection theory). In the first experiment, a comparison of three age groups (young, middle-aged, elderly) showed that perceptual sensitivity decreased with age and that the decision criterion became more conservative. In the second experiment, measurement of the useful visual field was carried out on participants who had been deprived of sleep the previous night or had a complete night of sleep. Perceptual sensitivity significantly decreased with sleep debt, and sleep deprivation provoked an increase in the participants' decision criterion. Moreover, the comparison of two age groups (young, middle-aged) indicated that sensitivity decreased with age. The value of using these two indices to explain the deterioration of useful visual field is discussed.

Effectiveness of imatinib mesylate over etoposide in the treatment of sensitive and resistant chronic myeloid leukaemia cells in vitro.

PubMed

Husaini, Roslina; Ahmad, Munirah; Zakaria, Zubaidah

2017-06-01

Chronic myeloid leukaemia (CML) is a form of leukaemia derived from the myeloid cell lineage. Imatinib mesylate, the breakpoint cluster region-abelson murine leukeamia kinase inhibitor, is a specific reagent used in the clinical treatment of CML. The DNA topoisomerase II inhibitor, etoposide, is also employed as a therapeutic, though it is used to a lesser extent. The present study aims to evaluate the effects of CML-targeted therapy, utilising imatinib mesylate and etoposide in the in vitro treatment of parental sensitive and adriamycin-resistant CML in the K562 and K562/ADM cell lines, respectively. Preliminary work involved the screening of multidrug resistant (MDR) gene expression, including MDR1, MRP1 and B-cell lymphoma 2 (BCL-2) at the mRNA levels. The sensitive and resistant CML cell lines expressed the MRP1 gene, though the sensitive K562 cells expressed low, almost undetectable levels of MDR1 and BCL-2 genes relative to the K562/ADM cells. Following treatment with imatinib mesylate or etoposide, the IC50 for imatinib mesylate did not differ between the sensitive and resistant cell lines (0.492±0.024 and 0.378±0.029, respectively), indicating that imatinib mesylate is effective in the treatment of CML regardless of cell chemosensitivity. However, the IC50 for etoposide in sensitive K562 cells was markedly lower than that of K562/ADM cells (50.6±16.5 and 194±8.46 µM, respectively), suggesting that the higher expression levels of MDR1 and/or BCL-2 mRNA in resistant cells may be partially responsible for this effect. This is supported by terminal deoxynucleotidyl transferase dUTP nick-end labeling data, whereby a higher percentage of apoptotic cells were found in the sensitive and resistant K562 cells treated with imatinib mesylate (29.3±0.2 and 31.9±16.7%, respectively), whereas etoposide caused significant apoptosis of sensitive K562 cells (18.3±8.35%) relative to K562/ADM cells (5.17±3.3%). In addition, the MDR genes in K562/ADM cells were knocked down by short interfering RNAs. The percentage knockdowns were 15.4% for MRP1, 17.8% for MDR and 30.7% for BCL-2, which resulted in a non-significant difference in the half maximal inhibitory concentration value of K562/ADM cells relative to K562 cells upon treatment with etoposide.

Ku70 inhibits gemcitabine-induced DNA damage and pancreatic cancer cell apoptosis

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

Ma, Jiali; Hui, Pingping; Meng, Wenying

The current study focused on the role of Ku70, a DNA-dependent protein kinase (DNA-PK) complex protein, in pancreatic cancer cell resistance to gemcitabine. In both established cell lines (Mia-PaCa-2 and PANC-1) and primary human pancreatic cancer cells, shRNA/siRNA-mediated knockdown of Ku70 significantly sensitized gemcitabine-induced cell death and proliferation inhibition. Meanwhile, gemcitabine-induced DNA damage and subsequent pancreatic cancer cell apoptosis were also potentiated with Ku70 knockdown. On the other hand, exogenous overexpression of Ku70 in Mia-PaCa-2 cells suppressed gemcitabine-induced DNA damage and subsequent cell apoptosis. In a severe combined immune deficient (SCID) mice Mia-PaCa-2 xenograft model, gemcitabine-induced anti-tumor activity was remarkably pontificatedmore » when combined with Ku70 shRNA knockdown in the xenografts. The results of this preclinical study imply that Ku70 might be a primary resistance factor of gemcitabine, and Ku70 silence could significantly chemo-sensitize gemcitabine in pancreatic cancer cells. - Highlights: • Ku70 knockdown sensitizes gemcitabine-induced killing of pancreatic cancer cells. • Ku70 knockdown facilitates gemcitabine-induced DNA damage and cell apoptosis. • Ku70 overexpression deceases gemcitabine's sensitivity in pancreatic cancer cells. • Ku70 knockdown sensitizes gemcitabine-induced anti-tumor activity in vivo.« less

Overexpression of Nitrogen Permease Regulator Like-2 (NPRL2) Enhances Sensitivity to Irinotecan (CPT-11) in Colon Cancer Cells by Activating the DNA Damage Checkpoint Pathway.

PubMed

Liu, Shasha; Liu, Bingrong

2018-03-09

BACKGROUND Colorectal cancer (CRC) is the third most common cancer worldwide, making it is a serious threat to human health. It is imperative to develop new therapeutics to improve the CRC treatment efficiency. The aim of this study was to investigate the role of NPRL2 in improving sensitivity to CPT-11 in colon cancer cells. MATERIAL AND METHODS NPRL2 overexpression was established by transfecting the recombinant lentivirus-encoding NPRL2 gene into HCT116 colon cancer cells. Cell proliferation was identified using Cell Counting Kit-8 (CCK8) assay. Cell cycle and apoptosis were examined by flow cytometry. An immunofluorescence staining assay was conducted to examine the expression of γ-H2AX. Wound-healing and Transwell assays were utilized to show cell migration and invasion capability. The expression of apoptosis-related proteins (cleaved caspase-3, caspase-9, cleaved PARP, BAX, and Bcl-2), invasion-related proteins (MMP2, MMP9, p-PI3K, and p-AKT), and DNA damage checkpoint pathway proteins (p-ATM, p-Chk2, Cdc25C, Cdc2, and Cyclin B1) were quantified by Western blotting. RESULTS A CCK8 assay revealed that the overexpression of NPRL2 improved the sensitivity of CPT-11 in HCT116 cells (P<0.05). Functionally, NPRL2 overexpression elevated the sensitivity of CPT-11 by preventing colon cancer cell proliferation, cell movement, and invasion, and promoting cell apoptosis and G2/M cell cycle arrest. Mechanistically, NPRL2 overexpression enhanced CPT-11 sensitivity by activating the DNA damage checkpoint pathway. CONCLUSIONS NPRL2 overexpression enhances sensitivity to CPT-11 treatment in colon cancer cells, and it may serve as a molecular therapeutic agent to treat patients with CRC.

Evaluation of selected biomarkers for the detection of chemical sensitization in human skin: a comparative study applying THP-1, MUTZ-3 and primary dendritic cells in culture.

PubMed

Hitzler, Manuel; Bergert, Antje; Luch, Andreas; Peiser, Matthias

2013-09-01

Dendritic cells (DCs) exhibit the unique capacity to induce T cell differentiation and proliferation, two processes that are crucially involved in allergic reactions. By combining the exclusive potential of DCs as the only professional antigen-presenting cells of the human body with the well known handling advantages of cell lines, cell-based alternative methods aimed at detecting chemical sensitization in vitro commonly apply DC-like cells derived from myeloid cell lines. Here, we present the new biomarkers programmed death-ligand 1 (PD-L1), DC immunoreceptor (DCIR), IL-16, and neutrophil-activating protein-2 (NAP-2), all of which have been detectable in primary human DCs upon exposure to chemical contact allergens. To evaluate the applicability of DC-like cells in the prediction of a chemical's sensitization potential, the expression of cell surface PD-L1 and DCIR was analyzed. In contrast to primary DCs, only minor subpopulations of MUTZ-3 and THP-1 cells presented PD-L1 or DCIR at their surface. After exposure to increasing concentrations of nickel and cinnamic aldehyde, the expression level of PD-L1 and DCIR revealed much stronger affected on monocyte-derived DCs (MoDCs) or Langerhans cells (MoLCs) when compared to THP-1 and MUTZ-3 cells. Applying protein profiler arrays we further identified the soluble factors NAP-2, IL-16, IL-8 and MIP-1α as sensitive biomarkers showing the capacity to discriminate sensitizing from non-sensitizing chemicals or irritants. An allergen-specific release of IL-8 and MIP-1α could be detected in the supernatants of MoDCs and MoLCs and also in MUTZ-3 and THP-1 cells, though at much lower levels. On the protein and transcriptional level, NAP-2 and IL-16 indicated sensitizers most sensitively and specifically in MoDCs. Altogether, we have proven the reciprocal regulated surface molecules PD-L1 and DCIR and the soluble factors MIP-1α, NAP-2 and IL-16 as reliable biomarkers for chemical sensitization. We further show that primary DCs are significantly different in their phenotype and function compared to DC-like cell lines. Since they demonstrated higher absolute values and a broader range in biomarker expression, we propose that MoDCs represent an optimal and robust sensor test system well suited to identify and classify chemicals with an allergic potential. Copyright © 2013 Elsevier Ltd. All rights reserved.

Probing lithium-ion batteries' state-of-charge using ultrasonic transmission - Concept and laboratory testing

NASA Astrophysics Data System (ADS)

Gold, Lukas; Bach, Tobias; Virsik, Wolfgang; Schmitt, Angelika; Müller, Jana; Staab, Torsten E. M.; Sextl, Gerhard

2017-03-01

For electrically powered applications such as consumer electronics and especially for electric vehicles a precise state-of-charge estimation for their lithium-ion batteries is desired to reduce aging, e.g. avoiding detrimental states-of-charge. Today, this estimation is performed by battery management systems that solely rely on charge bookkeeping and cell voltage measurements. In the present work we introduce a new, physical probe for the state-of-charge based on ultrasonic transmission. Within the simple experimental setup raised cosine pulses are applied to lithium-ion battery pouch cells, whose signals are sensitive to changes in porosity of the graphite anode during charging/dis-charging and, therefore, to the state-of-charge. The underlying physical principle can be related to Biot's theory about propagation of waves in fluid saturated porous media and by including scattering by boundary layers inside the cell.

Highly sensitive and specific colorimetric detection of cancer cells via dual-aptamer target binding strategy.

PubMed

Wang, Kun; Fan, Daoqing; Liu, Yaqing; Wang, Erkang

2015-11-15

Simple, rapid, sensitive and specific detection of cancer cells is of great importance for early and accurate cancer diagnostics and therapy. By coupling nanotechnology and dual-aptamer target binding strategies, we developed a colorimetric assay for visually detecting cancer cells with high sensitivity and specificity. The nanotechnology including high catalytic activity of PtAuNP and magnetic separation & concentration plays a vital role on the signal amplification and improvement of detection sensitivity. The color change caused by small amount of target cancer cells (10 cells/mL) can be clearly distinguished by naked eyes. The dual-aptamer target binding strategy guarantees the detection specificity that large amount of non-cancer cells and different cancer cells (10(4) cells/mL) cannot cause obvious color change. A detection limit as low as 10 cells/mL with detection linear range from 10 to 10(5) cells/mL was reached according to the experimental detections in phosphate buffer solution as well as serum sample. The developed enzyme-free and cost effective colorimetric assay is simple and no need of instrument while still provides excellent sensitivity, specificity and repeatability, having potential application on point-of-care cancer diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Omega-3 Polyunsaturated Fatty Acids Eicosapentaenoic Acid and Docosahexaenoic Acid Enhance Dexamethasone Sensitivity in Multiple Myeloma Cells by the p53/miR-34a/Bcl-2 Axis.

PubMed

Dai, Xianping; Li, Mengshun; Geng, Feng

2017-07-01

Dexamethasone is widely used in multiple myeloma (MM) for its cytotoxic effects on lymphoid cells. However, many MM patients are resistant to dexamethasone, although some can benefit from dexamethasone treatment. In this study, we noted that ω-3 polyunsaturated fatty acids (PUFAs) enhanced the dexamethasone sensitivity of MM cells by inducing cell apoptosis. q-PCR analysis revealed that miR-34a could be significantly induced by PUFAs in U266 and primary MM cells. Transfection with miR-34a antagonist or miR-34a agomir could restore or suppress the dexamethasone sensitivity in U266 cells. Both luciferase reporter assay and Western blot showed that Bcl-2 is the direct target of miR-34a in MM cells. In addition, we observed that PUFAs induced p53 protein expression in MM cells under dexamethasone administration. Furthermore, suppressing p53 by its inhibitor, Pifithrin-α, regulated the miR-34a expression and modulated the sensitivity to dexamethasone in U266 cells. In summary, these results suggest that PUFAs enhance dexamethasone sensitivity to MM cells through the p53/miR-34a axis with a likely contribution of Bcl-2 suppression.

Characterization of ibrutinib-sensitive and -resistant mantle lymphoma cells.

PubMed

Ma, Jiao; Lu, Pin; Guo, Ailin; Cheng, Shuhua; Zong, Hongliang; Martin, Peter; Coleman, Morton; Wang, Y Lynn

2014-09-01

Ibrutinib inhibits Bruton tyrosine kinase (BTK), a key component of early B-cell receptor (BCR) signalling pathways. A multicentre phase 2 trial of ibrutinib in patients with relapsed/refractory mantle cell lymphoma (MCL) demonstrated a remarkable response rate. However, approximately one-third of patients have primary resistance to the drug while other patients appear to lose response and develop secondary resistance. Understanding the molecular mechanisms underlying ibrutinib sensitivity is of paramount importance. In this study, we investigated cell lines and primary MCL cells that display differential sensitivity to ibrutinib. We found that the primary cells display a higher BTK activity than normal B cells and MCL cells show differential sensitivity to BTK inhibition. Genetic knockdown of BTK inhibits the growth, survival and proliferation of ibrutinib-sensitive but not resistant MCL cell lines, suggesting that ibrutinib acts through BTK to produce its anti-tumour activities. Interestingly, inhibition of ERK1/2 and AKT, but not BTK phosphorylation per se, correlates well with cellular response to BTK inhibition in cell lines as well as in primary tumours. Our study suggests that, to prevent primary resistance or to overcome secondary resistance to BTK inhibition, a combinatory strategy that targets multiple components or multiple pathways may represent the most effective approach. © 2014 John Wiley & Sons Ltd.

Fabrication of dye-sensitized solar cell using chlorophylls pigment from sargassum

NASA Astrophysics Data System (ADS)

Ridwan, M. A.; Noor, E.; Rusli, M. S.; Akhiruddin

2018-04-01

Dye-sensitized solar cell (DSSC) is a new generation of the solar cell. Its development in the dye-sensitized system is varied. Natural dyes have been the choice in developing DSSC. This study used a dye-sensitized chlorophyll pigment from Sargassum sp. as a dye-sensitized solar cell. This study aims to obtain chlorophyll pigment extract to be used as a dye in DSSC and to obtain the best energy conversion efficiency from DSSC. The chlorophyll pigments were extracted using APHA method (2012), and the TiO2 coating method used was doctor blade method. The two fabricated cells have an area of 1 cm2 immersed with chlorophyll dye for 30 hours. Then these cells were tested using direct sun radiation. The concentration value of chlorophyll in acetone solution was 61.176 mg/L. The efficiency value obtained was 1.50% with VOC of 241 mV, ISC 2.9 x 10-4 mA and fill factor 0.432.

ATM-Deficient Colorectal Cancer Cells Are Sensitive to the PARP Inhibitor Olaparib.

PubMed

Wang, Chen; Jette, Nicholas; Moussienko, Daniel; Bebb, D Gwyn; Lees-Miller, Susan P

2017-04-01

The ataxia telangiectasia mutated (ATM) protein kinase plays a central role in the cellular response to DNA damage. Loss or inactivation of both copies of the ATM gene (ATM) leads to ataxia telangiectasia, a devastating childhood condition characterized by neurodegeneration, immune deficiencies, and cancer predisposition. ATM is also absent in approximately 40% of mantle cell lymphomas (MCLs), and we previously showed that MCL cell lines with loss of ATM are sensitive to poly-ADP ribose polymerase (PARP) inhibitors. Next-generation sequencing of patient tumors has revealed that ATM is altered in many human cancers including colorectal, lung, prostate, and breast. Here, we show that the colorectal cancer cell line SK-CO-1 lacks detectable ATM protein expression and is sensitive to the PARP inhibitor olaparib. Similarly, HCT116 colorectal cancer cells with shRNA depletion of ATM are sensitive to olaparib, and depletion of p53 enhances this sensitivity. Moreover, HCT116 cells are sensitive to olaparib in combination with the ATM inhibitor KU55933, and sensitivity is enhanced by deletion of p53. Together our studies suggest that PARP inhibitors may have potential for treating colorectal cancer with ATM dysfunction and/or colorectal cancer with mutation of p53 when combined with an ATM kinase inhibitor. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

AGEs/sRAGE, a novel risk factor in the pathogenesis of end-stage renal disease.

PubMed

Prasad, Kailash; Dhar, Indu; Zhou, Qifeng; Elmoselhi, Hamdi; Shoker, Muhammad; Shoker, Ahmed

2016-12-01

Interaction of advanced glycation end products (AGEs) with its cell-bound receptor (RAGE) results in cell dysfunction through activation of nuclear factor kappa-B, increase in expression and release of inflammatory cytokines, and generation of oxygen radicals. Circulating soluble receptors, soluble receptor (sRAGE), endogenous secretory receptor (esRAGE) and cleaved receptor (cRGAE) act as decoy for RAGE ligands and thus have cytoprotective effects. Low levels of sRAGE and esRAGE have been proposed as biomarkers for many diseases. However sRAGE and esRAGE levels are elevated in diabetes and chronic renal diseases and still tissue injury occurs. It is possible that increases in levels of AGEs are greater than increases in the levels of soluble receptors in these two diseases. Some new parameters have to be used which could be an universal biomarkers for cell dysfunction. It is hypothesized that increases in serum levels of AGEs are greater than the increases in the soluble receptors, and that the levels of AGEs is correlated with soluble receptors and that the ratios of AGEs/sRAGE, AGEs/esRAGE and AGEs/cRAGE are elevated in patients with end-stage renal disease (ESRD) and would serve as an universal risk marker for ESRD. The study subject comprised of 88 patients with ESRD and 20 healthy controls. AGEs, sRAGE and esRAGE were measured using commercially available enzyme linked immune assay kits. cRAGE was calculated by subtracting esRAGE from sRAGE. The data show that the serum levels of AGEs, sRAGE, cRAGE are elevated and that the elevation of AGEs was greater than those of soluble receptors. The ratios of AGEs/sRAGE, AGEs/esRAGE and AGEs/cRAGE were elevated and the elevation was similar in AGEs/sRAGE and AGEs/cRAGE but greater than AGEs/esRAGE. The sensitivity, specificity, accuracy, and positive and negative predictive value of AGEs/sRAGE and AGEs/cRAGE were 86.36 and 84.88 %, 86.36 and 80.95 %, 0.98 and 0.905, 96.2 and 94.8 %, and 61.29 and 56.67 % respectively. There was a positive correlation of sRAGE with esRAGE and cRAGE, and AGEs with esRAGE; and negative correlation between sRAGE and AGEs/sRAGE, esRAGE and AGES/esRAGE, and cRAGE and AGES/cRAGE. In conclusion, AGEs/sRAGE, AGEs/cRAGE and AGEs/esRAGE may serve as universal risk biomarkers for ESRD and that AGEs/sRAGE and AGEs/cRAGE are better risk biomarkers than AGEs/esRAGE.

Divergent Pseudomonas exotoxin A sensitivity in normal and transformed liver cells is correlated with low-density lipoprotein receptor-related protein expression.

PubMed

Laithwaite, J E; Benn, S J; Marshall, W S; FitzGerald, D J; LaMarre, J

2001-09-01

Pseudomonas exotoxin A (PEA) is an extracellular virulence factor produced by the opportunistic human pathogen Pseudomonas aerguinosa. PEA intoxification begins when PEA binds to the low-density lipoprotein receptor-related protein (LRP). The liver is the primary target of systemic PEA, due largely to the high levels of functional LRP expressed by liver cells. Using a 3H-leucine incorporation assay to measure inhibition of protein synthesis we have demonstrated that normal (BNL CL.2) and transformed (BNL 1ME A7R.1) liver cells exhibit divergent PEA sensitivity; with BNL 1ME A7R.1 cells demonstrating greater PEA sensitivity than their non-transformed counterparts. The receptor-associated protein, a LRP antagonist, decreased PEA toxicity in BNL 1ME A7R.1 cells, confirming the importance of the LRP in PEA intoxification in this cell type. Increased PEA sensitivity in BNL 1ME A7R.1 cells was associated with increased functional cell surface LRP expression, as measured by alpha2-macroglobulin binding and internalization studies, and increased LRP mRNA levels, as determined by Northern blot analysis. Interestingly, BNL CL.2 cells were more sensitive than BNL 1ME A7R.1 cells to conjugate and mutant PEA toxins that do not utilize the LRP for cellular entry. These data demonstrate that increased LRP expression is an important mechanism by which PEA sensitivity is increased in BNL 1ME A7R.1 transformed liver cells.

Enhanced yield of chromosome aberrations after CT examinations in paediatric patients.

PubMed

Stephan, G; Schneider, K; Panzer, W; Walsh, L; Oestreicher, U

2007-05-01

To determine whether computed tomography (CT) could enhance the chromosome aberration yields in paediatric patients. Blood samples were taken before and after CT scans from 10 children for whom the medical justifications for CT examinations were accidental injuries and not diseases as investigated in earlier studies. Chromosome analysis was carried out in lymphocytes by fluorescence plus Giemsa (FPG) staining exclusively in metaphases of the first cell cycle in vitro. The mean blood dose of the 10 children was about 12.9 mGy which was determined by a newly developed dose estimation. Based on more than 20,000 analyzed cells it was found that after CT examination the frequencies of dicentrics (dic) and excess acentric fragments (ace) in lymphocytes were significantly increased. By subdividing the children into two age groups, those with an age from 0.4 years to 9 years and from 10 - 15 years, it became obvious that the observed increase in chromosome aberrations was mainly contributed by the younger age group. In this group the frequency of dicentrics was significantly increased whereas in the older group the observed increase was not significant. Our results demonstrate that CT examinations enhance the dicentrics yields in peripheral lymphocytes of children aged up to 15 years. Since in particular significantly increased dicentric yields could be observed in children with an age from 0.4 - 9 years, it can be assumed that children younger than 10 years may be more radiation sensitive than older subjects.

Der p 1 suppresses indoleamine 2, 3-dioxygenase in dendritic cells from house dust mite-sensitive patients with asthma.

PubMed

Maneechotesuwan, Kittipong; Wamanuttajinda, Valla; Kasetsinsombat, Kanda; Huabprasert, Sukit; Yaikwawong, Metha; Barnes, Peter J; Wongkajornsilp, Adisak

2009-01-01

Indoleamine 2, 3-dioxygenase (IDO), a tryptophan-degrading enzyme in dendritic cells (DCs), mediates an immunosuppressive effect on activated T lymphocytes. However, little is known about the effect of Der p 1 on IDO in human DCs. The aim was to investigate the effect of Der p 1 on the expression and activity of IDO in monocyte-derived DCs from house dust mite (HDM)-sensitive patients with asthma. Using real-time RT-PCR and HPLC, the expression and activity of IDO were assessed in TNF-alpha-induced mature DCs from HDM-sensitive and nonatopic patients with asthma in response to Der p 1 exposure ex vivo. We also monitored the alteration of IDO activity in Der p 1-pulsed DCs after the coincubation with autologous T cells. With a reliance on its protease activity, Der p 1 suppressed functional IDO in DCs from HDM-sensitive patients with asthma but enhanced IDO activity in DCs from nonatopic patients with asthma. This suppression was maintained by the reciprocally induced IL-4 from the coculturing autologous HDM-sensitive T cells. Conversely, the upregulation of IDO activity in Der p 1-pulsed DCs was maintained by IFN-gamma released from autologous nonatopic T cells and the regulatory T-cell subset. Der p 1 pulsation to sensitive DCs failed to raise regulatory T cells but raised progenitor fractions from cloned HDM-sensitive CD4(+) cells through direct contact and soluble mediators. House dust mite-sensitive DCs exposed to Der p 1 downregulated IDO activity and tipped the T(H)1/T(H)2 cytokine balance toward IL-4, resulting in sustainable IDO suppression.

Sensitivity to Stroke Emerges in Kindergartners Reading Chinese Script.

PubMed

Li, Su; Yin, Li

2017-01-01

To what extent are young children sensitive to individual stroke, the smallest unit of writing in Chinese that carries no phonological or semantic information? The present study examined Chinese kindergartners' sensitivity to stroke and the contribution of reading ability and age to stroke sensitivity. Fifty five children from Beijing, including 28 4-year-olds ( M age = 4.55 years, SD = 0.28, 16 males) and 29 5-year-olds ( M age = 5.58 years, SD = 0.30, 14 males), were administered an orthographic matching task and assessed on non-verbal IQ and Chinese word reading. In the orthographic matching task, children were asked to decide whether two items were exactly the same or different in three conditions, with stimuli being correctly written characters (e.g., "), stroke-missing or redundant characters (e.g., "), and Tibetan alphabets (e.g., "), respectively. The stimuli were presented with E-prime 2.0 software and were displayed on a Surface Pro. Children responded by touching the screen and reaction time was used as a measure of processing efficiency. The 5-year-olds but not the 4-year-olds processed correctly written characters more efficiently than stroke-missing/redundant characters, suggesting emergence of stroke sensitivity from age 5. The 4- and 5-year-olds both processed correctly written characters more efficiently than Tibetan alphabets, ruling out the possibility that the 5 year olds' sensitivity to stroke was due to the unusual look of the stimuli. Hierarchical regression analyses showed that Chinese word reading explained 10% additional variance in stroke sensitivity after having statistically controlled for age. Age did not account for additional variance in stroke sensitivity after having considered Chinese word reading. Taken together, findings of this study revealed that despite the visually highly complex nature of Chinese and the fact that individual stroke carries no phonological or semantic information, children develop sensitivity to stroke from age 5 and such sensitivity is significantly associated with reading experience.

CD8+ T cells stimulate Na-Cl co-transporter NCC in distal convoluted tubules leading to salt-sensitive hypertension.

PubMed

Liu, Yunmeng; Rafferty, Tonya M; Rhee, Sung W; Webber, Jessica S; Song, Li; Ko, Benjamin; Hoover, Robert S; He, Beixiang; Mu, Shengyu

2017-01-09

Recent studies suggest a role for T lymphocytes in hypertension. However, whether T cells contribute to renal sodium retention and salt-sensitive hypertension is unknown. Here we demonstrate that T cells infiltrate into the kidney of salt-sensitive hypertensive animals. In particular, CD8 + T cells directly contact the distal convoluted tubule (DCT) in the kidneys of DOCA-salt mice and CD8 + T cell-injected mice, leading to up-regulation of the Na-Cl co-transporter NCC, p-NCC and the development of salt-sensitive hypertension. Co-culture with CD8 + T cells upregulates NCC in mouse DCT cells via ROS-induced activation of Src kinase, up-regulation of the K + channel Kir4.1, and stimulation of the Cl - channel ClC-K. The last event increases chloride efflux, leading to compensatory chloride influx via NCC activation at the cost of increasing sodium retention. Collectively, these findings provide a mechanism for adaptive immunity involvement in the kidney defect in sodium handling and the pathogenesis of salt-sensitive hypertension.

CD8+ T cells stimulate Na-Cl co-transporter NCC in distal convoluted tubules leading to salt-sensitive hypertension

PubMed Central

Liu, Yunmeng; Rafferty, Tonya M.; Rhee, Sung W.; Webber, Jessica S.; Song, Li; Ko, Benjamin; Hoover, Robert S.; He, Beixiang; Mu, Shengyu

2017-01-01

Recent studies suggest a role for T lymphocytes in hypertension. However, whether T cells contribute to renal sodium retention and salt-sensitive hypertension is unknown. Here we demonstrate that T cells infiltrate into the kidney of salt-sensitive hypertensive animals. In particular, CD8+ T cells directly contact the distal convoluted tubule (DCT) in the kidneys of DOCA-salt mice and CD8+ T cell-injected mice, leading to up-regulation of the Na-Cl co-transporter NCC, p-NCC and the development of salt-sensitive hypertension. Co-culture with CD8+ T cells upregulates NCC in mouse DCT cells via ROS-induced activation of Src kinase, up-regulation of the K+ channel Kir4.1, and stimulation of the Cl− channel ClC-K. The last event increases chloride efflux, leading to compensatory chloride influx via NCC activation at the cost of increasing sodium retention. Collectively, these findings provide a mechanism for adaptive immunity involvement in the kidney defect in sodium handling and the pathogenesis of salt-sensitive hypertension. PMID:28067240

Metabolic health of young adults who were born small for gestational age and treated with growth hormone, after cessation of growth hormone treatment: a 5-year longitudinal study.

PubMed

van der Steen, Manouk; Smeets, Carolina C J; Kerkhof, Gerthe F; Hokken-Koelega, Anita C S

2017-02-01

Growth hormone treatment reduces fat mass and insulin sensitivity and increases lean body mass. Data are only available for short-term longitudinal changes after cessation of growth hormone treatment in young adults born small for gestational age. We aimed to assess long-term changes over a 5-year period following cessation of growth hormone treatment. We did a longitudinal study of young adults born small for gestational age and previously treated with growth hormone. Individuals were followed up for 5 years after attainment of adult height, when growth hormone treatment was discontinued: assessments were done at cessation of growth hormone treatment and at 6 months, 2 years, and 5 years thereafter. Data 5 years after cessation of growth hormone were compared with untreated age-matched controls. We used dual-energy x-ray absorptiometry to assess body composition, and did frequently sampled intravenous glucose tolerance tests to assess insulin sensitivity, acute insulin response, and the disposition index (a measure of β-cell function). This study is registered with ISRCTN, numbers ISRCTN96883876 and ISRCTN65230311. Between April, 2004, and April, 2016, we followed up 199 young adults born small for gestational age and previously treated with growth hormone, during the 5 years after cessation of growth hormone treatment. Data at 5 years for these individuals were compared with those for 51 untreated adults born small for gestational age with short stature, 92 untreated adults born small for gestational age with spontaneous catch-up growth, and 142 adults born appropriate for gestational age and unexposed to growth hormone treatment. In young adults born small for gestational age and previously treated with growth hormone, 5 years after cessation of growth hormone treatment, there were increases in fat mass (estimated marginal mean 10·73 kg [95% CI 9·95-11·50] at cessation of treatment vs 16·12 kg [14·77-17·46] at 5 years; p<0·0001), trunk fat (5·34 kg [4·94-5·73] vs 7·86 kg [7·12-8·60]; p<0·0001), and limb fat (4·87 kg [4·49-5·25] vs 7·41 kg [6·78-8·05]; p<0·0001); furthermore, lean body mass had decreased (42·41 kg [95% CI 41·09-43·73] at cessation of treatment vs 41·42 kg [40·17-42·66] at 5 years; p=0·0013). Insulin sensitivity increased within 6 months of cessation and was sustained 5 years after treatment cessation (estimated marginal mean 4·14 mU/L [95% CI 3·79-4·53] at cessation of treatment vs 6·15 mU/L [5·21-7·24] at 5 years; p<0·0001), and acute insulin response was diminished at 6 months, which persisted at 5 year follow-up (597·63 mU/L [539·62-661·86] vs 393·69 mU/L [337·56-459·15]; p<0·0001). The disposition index was increased 6 months after treatment but values at 5 years were similar to those at cessation of treatment (2483·94 [95% CI 2233·43-2762·54] at cessation of treatment vs 2367·83 [2033·43-2757·22] at 5 years; p=0·49). 5 years after cessation of growth hormone treatment, adults born small for gestational age and previously treated with growth hormone had fat mass, insulin sensitivity, and disposition index similar to those of untreated adults born small for gestational age with short stature, but lean body mass (adjusted for sex and height) was lower (46·47 kg [44·95-48·00] in those born small for gestational age with short stature vs 44·32 kg [43·35-45·30] in those born small for gestational age and treated with growth hormone; p=0·007). In adults previously treated with growth hormone born small for gestational age, at 5 years after cessation of growth hormone treatment, compared with adults born small for gestational age with spontaneous catch-up growth and adults born appropriate for gestational age, lean body mass was lower and results from frequently sampled intravenous glucose tolerance tests were similar. Significant changes in body composition and insulin sensitivity were recorded 5 years after cessation of growth hormone treatment in adults born small for gestational age, reflecting a loss of pharmacological effects of growth hormone. 5 years after cessation of treatment, fat mass, insulin sensitivity, and β-cell function of previously treated adults were similar to untreated adults born small for gestational age with short stature, indicating that long-term growth hormone treatment in children born small for gestational age has no unfavourable effects on metabolic health in early adulthood. Novo Nordisk Farma BV (Netherlands). Copyright © 2017 Elsevier Ltd. All rights reserved.

Selection of optimal sensors for predicting performance of polymer electrolyte membrane fuel cell

NASA Astrophysics Data System (ADS)

Mao, Lei; Jackson, Lisa

2016-10-01

In this paper, sensor selection algorithms are investigated based on a sensitivity analysis, and the capability of optimal sensors in predicting PEM fuel cell performance is also studied using test data. The fuel cell model is developed for generating the sensitivity matrix relating sensor measurements and fuel cell health parameters. From the sensitivity matrix, two sensor selection approaches, including the largest gap method, and exhaustive brute force searching technique, are applied to find the optimal sensors providing reliable predictions. Based on the results, a sensor selection approach considering both sensor sensitivity and noise resistance is proposed to find the optimal sensor set with minimum size. Furthermore, the performance of the optimal sensor set is studied to predict fuel cell performance using test data from a PEM fuel cell system. Results demonstrate that with optimal sensors, the performance of PEM fuel cell can be predicted with good quality.

Discrimination of skin sensitizers from non-sensitizers by interleukin-1α and interleukin-6 production on cultured human keratinocytes.

PubMed

Jung, Daun; Che, Jeong-Hwan; Lim, Kyung-Min; Chun, Young-Jin; Heo, Yong; Seok, Seung Hyeok

2016-09-01

In vitro testing methods for classifying sensitizers could be valuable alternatives to in vivo sensitization testing using animal models, such as the murine local lymph node assay (LLNA) and the guinea pig maximization test (GMT), but there remains a need for in vitro methods that are more accurate and simpler to distinguish skin sensitizers from non-sensitizers. Thus, the aim of our study was to establish an in vitro assay as a screening tool for detecting skin sensitizers using the human keratinocyte cell line, HaCaT. HaCaT cells were exposed to 16 relevant skin sensitizers and 6 skin non-sensitizers. The highest dose used was the dose causing 75% cell viability (CV75) that we determined by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The levels of extracellular production of interleukin-1α (IL-1α) and IL-6 were measured. The sensitivity of IL-1α was 63%, specificity was 83% and accuracy was 68%. In the case of IL-6, sensitivity: 69%, specificity: 83% and accuracy: 73%. Thus, this study suggests that measuring extracellular production of pro-inflammatory cytokines IL-1α and IL-6 by human HaCaT cells may potentially classify skin sensitizers from non-sensitizers. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Genetic reduction of mitochondrial complex I function does not lead to loss of dopamine neurons in vivo.

PubMed

Kim, Hyung-Wook; Choi, Won-Seok; Sorscher, Noah; Park, Hyung Joon; Tronche, François; Palmiter, Richard D; Xia, Zhengui

2015-09-01

Inhibition of mitochondrial complex I activity is hypothesized to be one of the major mechanisms responsible for dopaminergic neuron death in Parkinson's disease. However, loss of complex I activity by systemic deletion of the Ndufs4 gene, one of the subunits comprising complex I, does not cause dopaminergic neuron death in culture. Here, we generated mice with conditional Ndufs4 knockout in dopaminergic neurons (Ndufs4 conditional knockout mice [cKO]) to examine the effect of complex I inhibition on dopaminergic neuron function and survival during aging and on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment in vivo. Ndufs4 cKO mice did not show enhanced dopaminergic neuron loss in the substantia nigra pars compacta or dopamine-dependent motor deficits over the 24-month life span. These mice were just as susceptible to MPTP as control mice. However, compared with control mice, Ndufs4 cKO mice exhibited an age-dependent reduction of dopamine in the striatum and increased α-synuclein phosphorylation in dopaminergic neurons of the substantia nigra pars compacta. We also used an inducible Ndufs4 knockout mouse strain (Ndufs4 inducible knockout) in which Ndufs4 is conditionally deleted in all cells in adult to examine the effect of adult onset, complex I inhibition on MPTP sensitivity of dopaminergic neurons. The Ndufs4 inducible knockout mice exhibited similar sensitivity to MPTP as control littermates. These data suggest that mitochondrial complex I inhibition in dopaminergic neurons does contribute to dopamine loss and the development of α-synuclein pathology. However, it is not sufficient to cause cell-autonomous dopaminergic neuron death during the normal life span of mice. Furthermore, mitochondrial complex I inhibition does not underlie MPTP toxicity in vivo in either cell autonomous or nonautonomous manner. These results provide strong evidence that inhibition of mitochondrial complex I activity is not sufficient to cause dopaminergic neuron death during aging nor does it contribute to dopamine neuron toxicity in the MPTP model of Parkinson's disease. These findings suggest the existence of alternative mechanisms of dopaminergic neuron death independent of mitochondrial complex I inhibition. Copyright © 2015 Elsevier Inc. All rights reserved.

α-Lipoic Acid Treatment Improves Vision-Related Quality of Life in Patients with Dry Age-Related Macular Degeneration.

PubMed

Tao, Yuan; Jiang, Pengfei; Wei, Yuhua; Wang, Ping; Sun, Xiaoling; Wang, Hong

2016-11-01

Dry form of age-related macular degeneration (AMD) constitutes 90% of AMD cases, and it is characterized by the formation of drusen under the retina and the slow breakdown of the light-sensing cells in the macula, which causes a gradual loss of central vision. Since oxidative stress is involved in the pathogenesis of dry AMD, α-lipoic acid (LA) with antioxidant properties was selected, and its effect on anti-oxidative markers and visual quality in patients with dry AMD was assessed. A total of 100 dry AMD patients (60-83 years old) were randomly assigned to LA treatment group (n = 50) and placebo control group (n = 50). We measured the serum superoxide dismutase (SOD) activity, an important marker of antioxidant defense, best-corrected visual acuity (BCVA), contrast sensitivity, and Chinese-Version Low Vision Quality of Life (CLVQOL) before and after LA or placebo intervention. Pearson correlation coefficients were calculated to explore the relationship between contrast sensitivity values and CLVQOL scores. There was a statistically significant increase in serum SOD activity after LA intervention. The CLVQOL score was improved significantly after LA treatment. The contrast sensitivity measured at middle and low spatial frequency was significantly higher after LA treatment. CLVQOL scores were positively correlated with contrast sensitivity at low spatial frequency (3 cyc/degree) in LA-treated group. These results indicate that LA treatment improves vision-related quality of life in patients with dry AMD probably by increasing antioxidant activity. Thus, LA can be regarded as a promising agent for the treatment of AMD.

Sensitivity to chromosomal breakage as risk factor in young adults with oral squamous cell carcinoma.

PubMed

Braakhuis, Boudewijn J M; Nieuwint, Aggie W M; Oostra, Anneke B; Joenje, Hans; Flach, Géke B; Graveland, A Peggy; Brakenhoff, Ruud H; Leemans, C René

2016-03-01

Oral squamous cell carcinoma (OSCC) may develop in young adults. In contrast to older patients, the well-known etiological factors, exposure to tobacco and alcohol, play a minor role in the carcinogenesis in this patient group. It has been suggested that an intrinsic susceptibility to environmental genotoxic exposures plays a role in the development of OSCC in these patients. The hypothesis was tested whether young OSCC patients have an increased sensitivity to induced chromosomal damage. Fourteen OSCC patients with an average age of 32 years (range 20-42) were selected. Peripheral blood lymphocytes and skin fibroblasts of patients and 14 healthy controls were subjected to the chromosome breakage test with Mitomycin C. This test is routinely used to identify Fanconi anemia patients, who are well-known for their inherited high sensitivity to this type of DNA damage, but also for the high risk to develop OSCC. Human papilloma virus status of the carcinomas was also determined. None of the 14 young patients with OSCC had an increased response in the MMC-chromosomal breakage test. All tumors tested negative for human papilloma virus. No evidence was obtained for the existence of a constitutional hypersensitivity to DNA chromosomal damage as a potential risk factor for OSCC in young adults. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A beta cell ATGL-lipolysis/adipose tissue axis controls energy homeostasis and body weight via insulin secretion in mice.

PubMed

Attané, Camille; Peyot, Marie-Line; Lussier, Roxane; Poursharifi, Pegah; Zhao, Shangang; Zhang, Dongwei; Morin, Johane; Pineda, Marco; Wang, Shupei; Dumortier, Olivier; Ruderman, Neil B; Mitchell, Grant A; Simons, Brigitte; Madiraju, S R Murthy; Joly, Erik; Prentki, Marc

2016-12-01

To directly assess the role of beta cell lipolysis in insulin secretion and whole-body energy homeostasis, inducible beta cell-specific adipose triglyceride lipase (ATGL)-deficient (B-Atgl-KO) mice were studied under normal diet (ND) and high-fat diet (HFD) conditions. Atgl flox/flox mice were cross-bred with Mip-Cre-ERT mice to generate Mip-Cre-ERT /+ ;Atgl flox/flox mice. At 8 weeks of age, these mice were injected with tamoxifen to induce deletion of beta cell-specific Atgl (also known as Pnpla2), and the mice were fed an ND or HFD. ND-fed male B-Atgl-KO mice showed decreased insulinaemia and glucose-induced insulin secretion (GSIS) in vivo. Changes in GSIS correlated with the islet content of long-chain saturated monoacylglycerol (MAG) species that have been proposed to be metabolic coupling factors for insulin secretion. Exogenous MAGs restored GSIS in B-Atgl-KO islets. B-Atgl-KO male mice fed an HFD showed reduced insulinaemia, glycaemia in the fasted and fed states and after glucose challenge, as well as enhanced insulin sensitivity. Moreover, decreased insulinaemia in B-Atgl-KO mice was associated with increased energy expenditure, and lipid metabolism in brown (BAT) and white (WAT) adipose tissues, leading to reduced fat mass and body weight. ATGL in beta cells regulates insulin secretion via the production of signalling MAGs. Decreased insulinaemia due to lowered GSIS protects B-Atgl-KO mice from diet-induced obesity, improves insulin sensitivity, increases lipid mobilisation from WAT and causes BAT activation. The results support the concept that fuel excess can drive obesity and diabetes via hyperinsulinaemia, and that an islet beta cell ATGL-lipolysis/adipose tissue axis controls energy homeostasis and body weight via insulin secretion.

Temporal and long-term gut microbiota variation in allergic disease: A prospective study from infancy to school age.

PubMed

Simonyté Sjödin, Kotryna; Hammarström, Marie-Louise; Rydén, Patrik; Sjödin, Andreas; Hernell, Olle; Engstrand, Lars; West, Christina E

2018-05-22

Compositional changes of the early life gut microbiota have been implicated in IgE-associated allergic disease but there is lack of longitudinal studies. We examined gut microbiota development from infancy to school age in relation to onset of IgE-associated allergic diseases. At 8 years of age, we also examined the relationship between gut microbiota and T-cell regulation, estimated as responses to polyclonal T-cell activation. Stool samples were collected from 93 children at 4, 6 and 13 months, and 8 years of age. The gut microbiota was profiled using 16S rRNA gene sequencing. Peripheral blood was drawn from all children and mononuclear cells were polyclonally activated. Levels of IL-10 and FOXP3 mRNA copies were determined using real-time quantitative reverse transcriptase-PCR. At 8 years of age 21 children were diagnosed with IgE-associated allergic disease and 90% displayed allergic comorbidity. Seventy-two children were non-allergic and non-sensitized. Statistical tests with multiple testing corrections demonstrated temporal underrepresentation of Ruminococcus and consistent underrepresentation of Bacteroides, Prevotella and Coprococcus in allergic compared to non-allergic children from infancy to school age. The gut microbiota of the allergic 8-year-olds was enriched in Bifidobacterium and depleted of Lactobacillus, Enterococcus and Lachnospira. In allergic 8-year-olds, Faecalibacterium correlated with IL-10 mRNA levels (r s =0.49 , P adj= 0.02) with the same trend for FOXP3 (r s =0.39 , P adj= 0.08). We identified both temporal and long-term variation in the differential abundance of specific bacterial genera in children developing IgE-associated allergic disease. Improved dietary interventions aiming at expanding immune-modulatory taxa could be studied for prevention of allergic disease. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Comparison of the diagnostic accuracy, sensitivity and specificity of four odontological methods for age evaluation in Italian children at the age threshold of 14 years using ROC curves.

PubMed

Pinchi, Vilma; Pradella, Francesco; Vitale, Giulia; Rugo, Dario; Nieri, Michele; Norelli, Gian-Aristide

2016-01-01

The age threshold of 14 years is relevant in Italy as the minimum age for criminal responsibility. It is of utmost importance to evaluate the diagnostic accuracy of every odontological method for age evaluation considering the sensitivity, or the ability to estimate the true positive cases, and the specificity, or the ability to estimate the true negative cases. The research aims to compare the specificity and sensitivity of four commonly adopted methods of dental age estimation - Demirjian, Haavikko, Willems and Cameriere - in a sample of Italian children aged between 11 and 16 years, with an age threshold of 14 years, using receiver operating characteristic curves and the area under the curve (AUC). In addition, new decision criteria are developed to increase the accuracy of the methods. Among the four odontological methods for age estimation adopted in the research, the Cameriere method showed the highest AUC in both female and male cohorts. The Cameriere method shows a high degree of accuracy at the age threshold of 14 years. To adopt the Cameriere method to estimate the 14-year age threshold more accurately, however, it is suggested - according to the Youden index - that the decision criterion be set at the lower value of 12.928 for females and 13.258 years for males, obtaining a sensitivity of 85% and specificity of 88% in females, and a sensitivity of 77% and specificity of 92% in males. If a specificity level >90% is needed, the cut-off point should be set at 12.959 years (82% sensitivity) for females. © The Author(s) 2015.

Variability of Offending Allergens of Allergic Rhinitis According to Age: Optimization of Skin Prick Test Allergens

PubMed Central

Lee, Ji-Eun; Ahn, Jae-Chul; Han, Doo Hee; Kim, Dong-Young; Kim, Jung-Whun; Cho, Sang-Heon; Park, Heung-Woo

2014-01-01

Purpose This study evaluates offending allergens in patients with allergic rhinitis (AR) according to age that establish a minimal panel for skin prick test (SPT) allergens required to identify if a patient is sensitized. Methods We retrospectively analyzed SPT results according to age to determine the minimum test battery panel necessary to screen at least 93%-95% of AR patients. Allergic skin tests (common airborne indoor and outdoor allergens) were performed on 7,182 patients from January 2007 to June 2011. All patients were classified into 9 groups according to age; subsequently, we investigated offending allergens by age group. Results A total of 5,032 (70.1%) patients were found sensitized to at least one of the 55 aeroallergen extracts tested. The annual ranking of offending allergens was not significantly different from each other over the past 5 years. House dust mites (HDM) were the most prevalent allergens ranked from first to third for all 5 years. The allergens in the minimum test panel differed slightly among all age groups; in addition, the types of sensitized allergen sources were more diverse in the older versus younger age group. HDM covered a larger proportion of the sensitized allergens in the younger age group versus the older age group. Testing with 5 allergens (Dermatophagoides farinae, Tetranychus urticae, oak, mugwort and cockroach) adequately identified over 90% of the sensitized patients. Conclusions A SPT with around 5-7 allergens adequately detected most of the sensitization in the majority of the age groups in Korea. However, this study suggests that physicians perform the SPT with appropriately selected allergens in each age category for the screening of AR. PMID:24404393

Variability of offending allergens of allergic rhinitis according to age: optimization of skin prick test allergens.

PubMed

Lee, Ji-Eun; Ahn, Jae-Chul; Han, Doo Hee; Kim, Dong-Young; Kim, Jung-Whun; Cho, Sang-Heon; Park, Heung-Woo; Rhee, Chae-Seo

2014-01-01

This study evaluates offending allergens in patients with allergic rhinitis (AR) according to age that establish a minimal panel for skin prick test (SPT) allergens required to identify if a patient is sensitized. We retrospectively analyzed SPT results according to age to determine the minimum test battery panel necessary to screen at least 93%-95% of AR patients. Allergic skin tests (common airborne indoor and outdoor allergens) were performed on 7,182 patients from January 2007 to June 2011. All patients were classified into 9 groups according to age; subsequently, we investigated offending allergens by age group. A total of 5,032 (70.1%) patients were found sensitized to at least one of the 55 aeroallergen extracts tested. The annual ranking of offending allergens was not significantly different from each other over the past 5 years. House dust mites (HDM) were the most prevalent allergens ranked from first to third for all 5 years. The allergens in the minimum test panel differed slightly among all age groups; in addition, the types of sensitized allergen sources were more diverse in the older versus younger age group. HDM covered a larger proportion of the sensitized allergens in the younger age group versus the older age group. Testing with 5 allergens (Dermatophagoides farinae, Tetranychus urticae, oak, mugwort and cockroach) adequately identified over 90% of the sensitized patients. A SPT with around 5-7 allergens adequately detected most of the sensitization in the majority of the age groups in Korea. However, this study suggests that physicians perform the SPT with appropriately selected allergens in each age category for the screening of AR.

Gene sensitizes cancer cells to chemotherapy drugs

Cancer.gov

NCI scientists have found that a gene, Schlafen-11 (SLFN11), sensitizes cells to substances known to cause irreparable damage to DNA.  As part of their study, the researchers used a repository of 60 cell types to identify predictors of cancer cell respons

Species-specific sensitivity to selenium-induced impairment of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis)

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

Miller, L.L., E-mail: lana.miller@uleth.ca; Hontela, A.

Species differences in physiological and biochemical attributes exist even among closely related species and may underlie species-specific sensitivity to toxicants. Rainbow trout (RT) are more sensitive than brook trout (BT) to the teratogenic effects of selenium (Se), but it is not known whether all tissues exhibit this pattern of vulnerability. In this study, primary cultures of RT and BT adrenocortical cells were exposed to selenite (Na{sub 2}SO{sub 3}) and selenomethionine (Se-Met) to compare cell viability and ACTH-stimulated cortisol secretion in the two fish species. Cortisol, the primary stress hormone in fish, facilitates maintenance of homeostasis when fish are exposed tomore » stressors, including toxicants. Cell viability was not affected by Se, but selenite impaired cortisol secretion, while Se-Met did not (RT and BT EC{sub 50} > 2000 mg/L). RT cells were more sensitive (EC{sub 50} = 8.7 mg/L) to selenite than BT cells (EC{sub 50} = 90.4 mg/L). To identify the targets where Se disrupts cortisol synthesis, selenite-impaired RT and BT cells were stimulated with ACTH, dbcAMP, OH-cholesterol, and pregnenolone. Selenite acted at different steps in the cortisol biosynthesis pathway in RT and BT cells, confirming a species-specific toxicity mechanism. To test the hypothesis that oxidative stress mediates Se-induced toxicity, selenite-impaired RT cells were exposed to NAC, BSO and antioxidants (DETCA, ATA, Vit A, and Vit E). Inhibition of SOD by DETCA enhanced selenite-induced cortisol impairment, indicating that oxidative stress plays a role in Se toxicity; however, modifying GSH content of the cells did not have an effect. The results of this study, with two closely related salmonids, provided additional evidence for species-specific differences in sensitivity to Se which should be considered when setting thresholds and water quality guidelines. - Research Highlights: > We investigated species-specific sensitivity to Se in trout adrenocortical cells. > Selenite, not Se-Met, disrupts cortisol secretion in trout adrenocortical cells. > Rainbow trout cells are more sensitive than brook trout cells to selenite toxicity. > Superoxide dismutase may protect adrenocortical cells from selenite toxicity.« less

Aging and sleep deprivation induce the unfolded protein response in the pancreas: implications for metabolism

PubMed Central

Naidoo, Nirinjini; Davis, James G; Zhu, Jingxu; Yabumoto, Maya; Singletary, Kristan; Brown, Marishka; Galante, Raymond; Agarwal, Beamon; Baur, Joseph A

2014-01-01

Sleep disruption has detrimental effects on glucose metabolism through pathways that remain poorly defined. Although numerous studies have examined the consequences of sleep deprivation (SD) in the brain, few have directly tested its effects on peripheral organs. We examined several tissues in mice for induction of the unfolded protein response (UPR) following acute SD. In young animals, we found a robust induction of BiP in the pancreas, indicating an active UPR. At baseline, pancreata from aged animals exhibited a marked increase in a pro-apoptotic transcription factor, CHOP, that was amplified by SD, whereas BiP induction was not observed, suggesting a maladaptive response to cellular stress with age. Acute SD increased plasma glucose levels in both young and old animals. However, this change was not overtly related to stress in the pancreatic beta cells, as plasma insulin levels were not lower following acute SD. Accordingly, animals subjected to acute SD remained tolerant to a glucose challenge. In a chronic SD experiment, young mice were found to be sensitized to insulin and have improved glycemic control, whereas aged animals became hyperglycemic and failed to maintain appropriate plasma insulin concentrations. Our results show that both age and SD cooperate to induce the UPR in pancreatic tissue. While changes in insulin secretion are unlikely to play a major role in the acute effects of SD, CHOP induction in pancreatic tissues suggests that chronic SD may contribute to the loss or dysfunction of endocrine cells and that these effects may be exacerbated by normal aging. PMID:24102714

Enhanced photovoltaic performance of Sb2S3-sensitized solar cells through surface treatments

NASA Astrophysics Data System (ADS)

Ye, Qing; Xu, Yafeng; Chen, Wenyong; Yang, Shangfeng; Zhu, Jun; Weng, Jian

2018-05-01

Efficient antimony sulfide (Sb2S3)-sensitized solar cells were obtained by a sequential treatment with thioacetamide (TA) and 1-decylphosphonic acid (DPA). Compared with the untreated Sb2S3-sensitized solar cells, the power conversion efficiency of the treated Sb2S3 solar cells was improved by 1.80% to 3.23%. The TA treatment improved the Sb2S3 films by reducing impurities and decreasing the film's surface defects, which inhibited the emergence of recombination centers. The DPA treatment reduced the recombination between hole transport materials (HTMs) and the Sb2S3. Therefore, we have presented an efficient strategy to improve the performance of Sb2S3-sensitized solar cells.

Binaural interaction in low-frequency neurons in inferior colliculus of the cat. II. Effects of changing rate and direction of interaural phase.

PubMed

Yin, T C; Kuwada, S

1983-10-01

We used the binaural beat stimulus to study the interaural phase sensitivity of inferior colliculus (IC) neurons in the cat. The binaural beat, produced by delivering tones of slightly different frequencies to the two ears, generates continuous and graded changes in interaural phase. Over 90% of the cells that exhibit a sensitivity to changes in the interaural delay also show a sensitivity to interaural phase disparities with the binaural beat. Cells respond with a burst of impulses with each complete cycle of the beat frequency. The period histogram obtained by binning the poststimulus time histogram on the beat frequency gives a measure of the interaural phase sensitivity of the cell. In general, there is good correspondence in the shapes of the period histograms generated from binaural beats and the interaural phase curves derived from interaural delays and in the mean interaural phase angle calculated from them. The magnitude of the beat frequency determines the rate of change of interaural phase and the sign determines the direction of phase change. While most cells respond in a phase-locked manner up to beat frequencies of 10 Hz, there are some cells tht will phase lock up to 80 Hz. Beat frequency and mean interaural phase angle are linearly related for most cells. Most cells respond equally in the two directions of phase change and with different rates of change, at least up to 10 Hz. However, some IC cells exhibit marked sensitivity to the speed of phase change, either responding more vigorously at low beat frequencies or at high beat frequencies. In addition, other cells demonstrate a clear directional sensitivity. The cells that show sensitivity to the direction and speed of phase changes would be expected to demonstrate a sensitivity to moving sound sources in the free field. Changes in the mean interaural phase of the binaural beat period histograms are used to determine the effects of changes in average and interaural intensity on the phase sensitivity of the cells. The effects of both forms of intensity variation are continuously distributed. The binaural beat offers a number of advantages for studying the interaural phase sensitivity of binaural cells. The dynamic characteristics of the interaural phase can be varied so that the speed and direction of phase change are under direct control. The data can be obtained in a much more efficient manner, as the binaural beat is about 10 times faster in terms of data collection than the interaural delay.

IgE sensitization in relation to preschool eczema and filaggrin mutation.

PubMed

Johansson, Emma Kristin; Bergström, Anna; Kull, Inger; Lind, Tomas; Söderhäll, Cilla; van Hage, Marianne; Wickman, Magnus; Ballardini, Natalia; Wahlgren, Carl-Fredrik

2017-12-01

Eczema (atopic dermatitis) is associated with an increased risk of having IgE antibodies. IgE sensitization can occur through an impaired skin barrier. Filaggrin gene (FLG) mutation is associated with eczema and possibly also with IgE sensitization. We sought to explore the longitudinal relation between preschool eczema (PSE), FLG mutation, or both and IgE sensitization in childhood. A total of 3201 children from the BAMSE (Children Allergy Milieu Stockholm Epidemiology) birth cohort recruited from the general population were included. Regular parental questionnaires identified children with eczema. Blood samples were collected at 4, 8, and 16 years of age for analysis of specific IgE. FLG mutation analysis was performed on 1890 of the children. PSE was associated with IgE sensitization to both food allergens and aeroallergens up to age 16 years (overall adjusted odds ratio, 2.30; 95% CI, 2.00-2.66). This association was even stronger among children with persistent PSE. FLG mutation was associated with IgE sensitization to peanut at age 4 years (adjusted odds ratio, 1.88; 95% CI, 1.03-3.44) but not to other allergens up to age 16 years. FLG mutation and PSE were not effect modifiers for the association between IgE sensitization and PSE or FLG mutation, respectively. Sensitized children with PSE were characterized by means of polysensitization, but no other specific IgE sensitization patterns were found. PSE is associated with IgE sensitization to both food allergens and aeroallergens up to 16 years of age. FLG mutation is associated with IgE sensitization to peanut but not to other allergens. Sensitized children with preceding PSE are more often polysensitized. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Radiosensitivity profiles from a panel of ovarian cancer cell lines exhibiting genetic alterations in p53 and disparate DNA-dependent protein kinase activities

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

Langland, Gregory T.; Yannone, Steven M.; Langland, Rachel A.

2009-09-07

The variability of radiation responses in ovarian tumors and tumor-derived cell lines is poorly understood. Since both DNA repair capacity and p53 status can significantly alter radiation sensitivity, we evaluated these factors along with radiation sensitivity in a panel of sporadic human ovarian carcinoma cell lines. We observed a gradation of radiation sensitivity among these sixteen lines, with a five-fold difference in the LD50 between the most radiosensitive and the most radioresistant cells. The DNA-dependent protein kinase (DNA-PK) is essential for the repair of radiation induced DNA double-strand breaks in human somatic cells. Therefore, we measured gene copy number, expressionmore » levels, protein abundance, genomic copy and kinase activity for DNA-PK in all of our cell lines. While there were detectable differences in DNA-PK between the cell lines, there was no clear correlation with any of these differences and radiation sensitivity. In contrast, p53 function as determined by two independent methods, correlated well with radiation sensitivity, indicating p53 mutant ovarian cancer cells are typically radioresistant relative to p53 wild-type lines. These data suggest that the activity of regulatory molecules such as p53 may be better indicators of radiation sensitivity than DNA repair enzymes such as DNAPK in ovarian cancer.« less

MMR Deficiency Does Not Sensitize or Compromise the Function of Hematopoietic Stem Cells to Low and High LET Radiation.

PubMed

Patel, Rutulkumar; Qing, Yulan; Kennedy, Lucy; Yan, Yan; Pink, John; Aguila, Brittany; Desai, Amar; Gerson, Stanton L; Welford, Scott M

2018-04-14

One of the major health concerns on long-duration space missions will be radiation exposure to the astronauts. Outside the earth's magnetosphere, astronauts will be exposed to galactic cosmic rays (GCR) and solar particle events that are principally composed of protons and He, Ca, O, Ne, Si, Ca, and Fe nuclei. Protons are by far the most common species, but the higher atomic number particles are thought to be more damaging to biological systems. Evaluation and amelioration of risks from GCR exposure will be important for deep space travel. The hematopoietic system is one of the most radiation-sensitive organ systems, and is highly dependent on functional DNA repair pathways for survival. Recent results from our group have demonstrated an acquired deficiency in mismatch repair (MMR) in human hematopoietic stem cells (HSCs) with age due to functional loss of the MLH1 protein, suggesting an additional risk to astronauts who may have significant numbers of MMR deficient HSCs at the time of space travel. In the present study, we investigated the effects gamma radiation, proton radiation, and 56 Fe radiation on HSC function in Mlh1 +/+ and Mlh1 -/- marrow from mice in a variety of assays and have determined that while cosmic radiation is a major risk to the hematopoietic system, there is no dependence on MMR capacity. Stem Cells Translational Medicine 2018. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Apigenin sensitizes BEL-7402/ADM cells to doxorubicin through inhibiting miR-101/Nrf2 pathway

PubMed Central

Gao, Ai-Mei; Zhang, Xiao-Yu; Ke, Zun-Ping

2017-01-01

Chemo-resistance is one of the main obstacle in hepatocellular carcinoma therapy. Apigenin as a natural bioflavonoid has been exhibited anti-cancer properties in various malignant cancers. The aim of this study is to evaluate the potential chemo-sensitization effect of apigenin in doxorubicin-resistant hepatocellular carcinoma cell line BEL-7402/ADM and to investigate its possible mechanism. We found that apigenin significantly reversed doxorubicin sensitivity and induced caspase-dependent apoptosis in BEL-7402/ADM cells. Furthermore, apigenin induced miR-101 expression, and overexpression of miR-101 mimicked the doxorubicin-sensitizing effect of apigenin. Importantly, we showed that miR-101 was able to target the 3′-UTR of Nrf2. The results suggested that apigenin sensitizes BEL-7402/ADM cells to doxorubicin through miR-101/Nrf2 pathway, which furtherly supports apigenin as a potential chemo-sensitizer for hepatocellular carcinoma. PMID:29137246

Synthesis of zinc chlorophyll materials for dye-sensitized solar cell applications

NASA Astrophysics Data System (ADS)

Erten-Ela, Sule; Vakuliuk, Olena; Tarnowska, Anna; Ocakoglu, Kasim; Gryko, Daniel T.

2015-01-01

To design sensitizers for dye sensitized solar cells (DSSCs), a series of zinc chlorins with different substituents were synthesized. Novel zinc methyl 3-devinyl-3-hydroxymethyl-20-phenylacetylenylpyropheophorbide-a (ZnChl-1), zinc methyl 20-bromo-3-devinyl-3-hydroxymethylpyropheophorbide-a (ZnChl-2), zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-3), zinc propyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-4) were synthesized and their photovoltaic performances were evaluated in dye-sensitized solar cells. Photoelectrodes with a 7 μm thick nanoporous layer and a 5 μm thick light-scattering layer were used to fabricate dye sensitized solar cells. The best efficiency was obtained with ZnChl-2 sensitizer. ZnChl-2 gave a Jsc of 3.5 mA/cm2, Voc of 412 mV, FF of 0.56 and an overall conversion efficiency of 0.81 at full sun (1000 W m-2).

Telomerase antagonist imetelstat increases radiation sensitivity in esophageal squamous cell carcinoma

PubMed Central

Wu, Xuping; Zhang, Jing; Yang, Sijun; Kuang, Zhihui; Tan, Guolei; Yang, Gang; Wei, Qichun; Guo, Zhigang

2017-01-01

The morbidity and mortality of esophageal cancer is one of the highest around the world and the principal therapeutic method is radiation. Thus, searching for sensitizers with lower toxicity and higher efficiency to improve the efficacy of radiation therapy is critical essential. Our research group has previously reported that imetelstat, the thio-phosphoramidate oligonucleotide inhibitor of telomerase, can decrease cell proliferation and colony formation ability as well as increase DNA breaks induced by radiation in esophageal cancer cells. Further study in this project showed that imetelstat significantly sensitized esophageal cancer cells to radiation in vitro. Later study showed that imetelstat leads to increased cell apoptosis. We also measured the expression level of several DNA repair and apoptosis signaling proteins. pS345 CHK1, γ-H2AX, p53 and caspase3 expression were up-regulated in imetelstat treated cells, identifying these factors as molecular markers. Mouse in vivo model using imetelstat at clinically achievable concentrations and fractionated irradiation scheme yielded results demonstrating radiosensitization effect. Finally, TUNEL assay, caspase 3 and Ki67 staining in tumor tissue proved that imetelstat sensitized esophageal cancer to radiation in vivo through promoting cell apoptosis and inhibiting cell proliferation. Our study supported imetelstat increase radiation sensitivity of esophageal squamous cell carcinoma through inducing cell apoptosis and the specific inhibitor of telomerase might serve as a potential novel therapeutic tool for esophageal squamous cell carcinoma therapy. PMID:28099140

Telomerase antagonist imetelstat increases radiation sensitivity in esophageal squamous cell carcinoma.

PubMed

Wu, Xuping; Zhang, Jing; Yang, Sijun; Kuang, Zhihui; Tan, Guolei; Yang, Gang; Wei, Qichun; Guo, Zhigang

2017-02-21

The morbidity and mortality of esophageal cancer is one of the highest around the world and the principal therapeutic method is radiation. Thus, searching for sensitizers with lower toxicity and higher efficiency to improve the efficacy of radiation therapy is critical essential. Our research group has previously reported that imetelstat, the thio-phosphoramidate oligonucleotide inhibitor of telomerase, can decrease cell proliferation and colony formation ability as well as increase DNA breaks induced by radiation in esophageal cancer cells. Further study in this project showed that imetelstat significantly sensitized esophageal cancer cells to radiation in vitro. Later study showed that imetelstat leads to increased cell apoptosis. We also measured the expression level of several DNA repair and apoptosis signaling proteins. pS345 CHK1, γ-H2AX, p53 and caspase3 expression were up-regulated in imetelstat treated cells, identifying these factors as molecular markers. Mouse in vivo model using imetelstat at clinically achievable concentrations and fractionated irradiation scheme yielded results demonstrating radiosensitization effect. Finally, TUNEL assay, caspase 3 and Ki67 staining in tumor tissue proved that imetelstat sensitized esophageal cancer to radiation in vivo through promoting cell apoptosis and inhibiting cell proliferation. Our study supported imetelstat increase radiation sensitivity of esophageal squamous cell carcinoma through inducing cell apoptosis and the specific inhibitor of telomerase might serve as a potential novel therapeutic tool for esophageal squamous cell carcinoma therapy.

Target of Rapamycin (TOR) in Nutrient Signaling and Growth Control

PubMed Central

Loewith, Robbie; Hall, Michael N.

2011-01-01

TOR (Target Of Rapamycin) is a highly conserved protein kinase that is important in both fundamental and clinical biology. In fundamental biology, TOR is a nutrient-sensitive, central controller of cell growth and aging. In clinical biology, TOR is implicated in many diseases and is the target of the drug rapamycin used in three different therapeutic areas. The yeast Saccharomyces cerevisiae has played a prominent role in both the discovery of TOR and the elucidation of its function. Here we review the TOR signaling network in S. cerevisiae. PMID:22174183

Value of parents' estimates of children's developmental ages.

PubMed

Glascoe, F P; Sandler, H

1995-11-01

To determine whether parents' estimates of children's developmental ages can function as a prescreening technique. Parents of 234 children from birth to 77 months of age seeking well-child care in pediatric offices were queried in two separate studies. In the first study, parents were asked to give an estimate of their child's overall developmental age and, in the second study, to estimate ages in each of six developmental domains. Children were administered a range of screening measures of intelligence, speech-language, and adoptive behavior. The overall age-estimate, if less than chronologic age, was 75% sensitive to likely developmental problems and, if equal to or greater than chronologic age, was 90% specific in identifying children likely to have typical development. Age estimates for each developmental domain were 81% sensitive to likely developmental problems if less than chronologic age in the domains of fine motor, language, grass motor, or behavior, and 62% specific if equal to or greater than chronologic age. Estimates at or below chronologic age in receptive language or personal-social domains were 90% sensitive and 43% specific in identifying likely behavior problems. There were no differences in the accuracy of parents estimates on the basis of children's age, gender, race, parents' level of education, or parenting experience. Parents' overall age-estimates provided a sensitive and specific indicator of global developmental status, but insufficient information about strengths and weaknesses to enable focused referrals for services. In contrast, discrete patterns of age estimates in each developmental domain sensitively discriminated children with developmental versus behavioral problems, although specificity was limited. Age estimates appear to be a potentially helpful method for identifying a subset of children in need of thorough screening, although further research is needed on a larger sample given diagnostic rather than screening tests.

A sensitive ELISA for measuring the adhesion of leukocytic cells to human endothelial cells.

PubMed

Krakauer, T

1994-12-28

A new, sensitive ELISA using monoclonal antibodies reactive with surface molecules specific for various leukocytes was devised to measure the attachment of these cells to cultured monolayers of human umbilical vein endothelial cells. Preparations of peripheral blood mononuclear cells, a human monocytic cell line (THP-1) and a human lymphoblastic T cell line (MOLT-4) were used to test the sensitivity of this method and compare it with the conventional 51Cr-radiolabeled cell assay. The extent of adhesion to endothelial cells was assayed by measuring the optical density produced by a complex of peroxidase-labeled streptavidin, biotin-conjugated F(ab')2 anti-mouse Ig and monoclonal antibody on fixed leukocytic cells that had adhered to endothelial cells. This method is fast and sensitive, eliminates the use of radioisotopes, and, because the detection uses a specific marker on the cell of interest, can be used in preparations of unseparated mixtures of cells. As this is a microassay, using relatively small number of cells and reagents, the methodology can be applied to screen a large number of therapeutic agents that may regulate adhesion. Using this method, the anti-inflammatory corticosteroid, dexamethasone, was found to inhibit the adhesion of THP-1 and MOLT-4 cells to cytokine-activated endothelial cells.

Mitochondrial Energy Metabolism and Redox Signaling in Brain Aging and Neurodegeneration

PubMed Central

Yin, Fei; Boveris, Alberto

2014-01-01

Abstract Significance: The mitochondrial energy-transducing capacity is essential for the maintenance of neuronal function, and the impairment of energy metabolism and redox homeostasis is a hallmark of brain aging, which is particularly accentuated in the early stages of neurodegenerative diseases. Recent Advances: The communications between mitochondria and the rest of the cell by energy- and redox-sensitive signaling establish a master regulatory device that controls cellular energy levels and the redox environment. Impairment of this regulatory devise is critical for aging and the early stages of neurodegenerative diseases. Critical Issues: This review focuses on a coordinated metabolic network—cytosolic signaling, transcriptional regulation, and mitochondrial function—that controls the cellular energy levels and redox status as well as factors which impair this metabolic network during brain aging and neurodegeneration. Future Directions: Characterization of mitochondrial function and mitochondria-cytosol communications will provide pivotal opportunities for identifying targets and developing new strategies aimed at restoring the mitochondrial energy-redox axis that is compromised in brain aging and neurodegeneration. Antioxid. Redox Signal. 20, 353–371. PMID:22793257

Metabolic determinants of cancer cell sensitivity to glucose limitation and biguanides

NASA Astrophysics Data System (ADS)

Birsoy, Kıvanç; Possemato, Richard; Lorbeer, Franziska K.; Bayraktar, Erol C.; Thiru, Prathapan; Yucel, Burcu; Wang, Tim; Chen, Walter W.; Clish, Clary B.; Sabatini, David M.

2014-04-01

As the concentrations of highly consumed nutrients, particularly glucose, are generally lower in tumours than in normal tissues, cancer cells must adapt their metabolism to the tumour microenvironment. A better understanding of these adaptations might reveal cancer cell liabilities that can be exploited for therapeutic benefit. Here we developed a continuous-flow culture apparatus (Nutrostat) for maintaining proliferating cells in low-nutrient media for long periods of time, and used it to undertake competitive proliferation assays on a pooled collection of barcoded cancer cell lines cultured in low-glucose conditions. Sensitivity to low glucose varies amongst cell lines, and an RNA interference (RNAi) screen pinpointed mitochondrial oxidative phosphorylation (OXPHOS) as the major pathway required for optimal proliferation in low glucose. We found that cell lines most sensitive to low glucose are defective in the OXPHOS upregulation that is normally caused by glucose limitation as a result of either mitochondrial DNA (mtDNA) mutations in complex I genes or impaired glucose utilization. These defects predict sensitivity to biguanides, antidiabetic drugs that inhibit OXPHOS, when cancer cells are grown in low glucose or as tumour xenografts. Notably, the biguanide sensitivity of cancer cells with mtDNA mutations was reversed by ectopic expression of yeast NDI1, a ubiquinone oxidoreductase that allows bypass of complex I function. Thus, we conclude that mtDNA mutations and impaired glucose utilization are potential biomarkers for identifying tumours with increased sensitivity to OXPHOS inhibitors.

Selective synthesis and characterization of chlorins as sensitizers for photodynamic therapy

NASA Astrophysics Data System (ADS)

Montforts, Franz-Peter; Kusch, Dirk; Hoper, Frank; Braun, Stefan; Gerlach, Benjamin; Brauer, Hans-Dieter; Schermann, Guido; Moser, Joerg G.

1996-04-01

Chlorin type sensitizers have ideal photophysical properties for an application in PDT. The basic chlorin framework of these sensitizers has to be modified by attachment of lipophilic and hydrophilic residues to achieve a good cell uptake and tumor enrichment. In the present study we describe the selective synthesis of amphiphilic chlorins starting from the readily accessible red blood pigment heme. The photophysical properties of the well defined synthetic chlorins are characterized by photophysical investigations. The kinetic of cell uptake, the localization in the cell and the photodynamic behavior of the amphiphilic sensitizers are demonstrated by incubation of A 375 cancer cell lines with structurally different chlorins.

Efficient PbS/CdS co-sensitized solar cells based on TiO2 nanorod arrays

PubMed Central

2013-01-01

Narrow bandgap PbS nanoparticles, which may expand the light absorption range to the near-infrared region, were deposited on TiO2 nanorod arrays by successive ionic layer adsorption and reaction method to make a photoanode for quantum dot-sensitized solar cells (QDSCs). The thicknesses of PbS nanoparticles were optimized to enhance the photovoltaic performance of PbS QDSCs. A uniform CdS layer was directly coated on previously grown PbS-TiO2 photoanode to protect the PbS from the chemical attack of polysulfide electrolytes. A remarkable short-circuit photocurrent density (approximately 10.4 mA/cm2) for PbS/CdS co-sensitized solar cell was recorded while the photocurrent density of only PbS-sensitized solar cells was lower than 3 mA/cm2. The power conversion efficiency of the PbS/CdS co-sensitized solar cell reached 1.3%, which was beyond the arithmetic addition of the efficiencies of single constituents (PbS and CdS). These results indicate that the synergistic combination of PbS with CdS may provide a stable and effective sensitizer for practical solar cell applications. PMID:23394609

Highly sensitive fetal goat tongue cell line for detection and isolation of foot-and-mouth disease virus.

PubMed

Brehm, K E; Ferris, N P; Lenk, M; Riebe, R; Haas, B

2009-10-01

A fetal goat cell line (ZZ-R 127) supplied by the Collection of Cell Lines in Veterinary Medicine of the Friedrich Loeffler Institute was examined for susceptibility to infection by foot-and-mouth disease (FMD) virus (FMDV) and by two other viruses causing clinically indistinguishable vesicular conditions, namely, the viruses of swine vesicular disease and vesicular stomatitis. Primary bovine thyroid (BTY) cells are generally the most sensitive cell culture system for FMDV detection but are problematic to produce, particularly for laboratories that infrequently perform FMD diagnostic tests and for those in countries where FMD is endemic that face problems in sourcing thyroid glands from FMD-negative calves. Strains representing all seven serotypes of FMDV could be isolated in ZZ-R 127 cells with a sensitivity that was considerably higher than that of established cell lines and within 0.5 log of that for BTY cells. The ZZ-R 127 cell line was found to be a sensitive, rapid, and convenient tool for the isolation of FMDV and a useful alternative to BTY cells for FMD diagnosis.

Glomerular Hyperfiltration in Adult Sickle Cell Anemia: A Frequent Hemolysis Associated Feature

PubMed Central

Stankovic, Katia; Levy, Pierre; Avellino, Virginie; Tharaux, Pierre-Louis; Letavernier, Emmanuel; Grateau, Gilles; Baud, Laurent; Girot, Robert; Lionnet, François

2010-01-01

Background and objectives: Sickle cell anemia-associated nephropathy is a growing matter of concern because renal failure affects most aging sickle cell anemia patients. Glomerular damage is a common feature revealed by a microalbuminuria or a macroalbuminuria. Although glomerular hyperfiltration has been described for decades in this population, its prevalence in young adults is unknown. Design, setting, participants, & measurements: To address this issue, as well as the clinical and biologic correlates of hyperfiltration, a single-center, cross-sectional study of 280 homozygous SS disease patients was performed. Results: The prevalence of hyperfiltration assessed by Modification of Diet in Renal Disease estimated GFR was 51%. Among patients with hyperfiltration, 49% had hyperfiltration alone, whereas 36% and 15% had an associated microalbuminuria or macroalbuminuria, respectively. Estimated GFR sensitivity and specificity for hyperfiltration were 94% and 63%, respectively, in a selected subgroup of 48 patients (measured GFR was assessed by urinary 51Cr EDTA clearance). In patients with no albuminuria, hyperfiltration status was significantly associated with a young age (years), the absence of alpha thalassemia, a lower hemoglobin level (g/dl), and a lower fetal hemoglobin. The role of chronic hemolysis was further strengthened by multivariate analysis showing a correlation between estimated GFR and a low plasma fetal hemoglobin level, a young age, and a high reticulocyte count (r2 = 0.54). Conclusions: Together, the data suggest that the pathophysiology of hyperfiltration would rather be attributable to the hemolysis-associated vasculopathy rather than a viscosity-vaso-occlusive process. PMID:20185605

Diagnostic performance of optical coherence tomography ganglion cell--inner plexiform layer thickness measurements in early glaucoma.

PubMed

Mwanza, Jean-Claude; Budenz, Donald L; Godfrey, David G; Neelakantan, Arvind; Sayyad, Fouad E; Chang, Robert T; Lee, Richard K

2014-04-01

To evaluate the glaucoma diagnostic performance of ganglion cell inner-plexiform layer (GCIPL) parameters used individually and in combination with retinal nerve fiber layer (RNFL) or optic nerve head (ONH) parameters measured with Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). Prospective cross-sectional study. Fifty patients with early perimetric glaucoma and 49 age-matched healthy subjects. Three peripapillary RNFL and 3 macular GCIPL scans were obtained in 1 eye of each participant. A patient was considered glaucomatous if at least 2 of the 3 RNFL or GCIPL scans had the average or at least 1 sector measurement flagged at 1% to 5% or less than 1%. The diagnostic performance was determined for each GCIPL, RNFL, and ONH parameter as well as for binary or-logic and and-logic combinations of GCIPL with RNFL or ONH parameters. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR). Among GCIPL parameters, the minimum had the best diagnostic performance (sensitivity, 82.0%; specificity, 87.8%; PLR, 6.69; and NLR, 0.21). Inferior quadrant was the best RNFL parameter (sensitivity, 74%; specificity, 95.9%; PLR, 18.13; and NLR, 0.27), as was rim area (sensitivity, 68%; specificity, 98%; PLR, 33.3; and NLR, 0.33) among ONH parameters. The or-logic combination of minimum GCIPL and average RNFL provided the overall best diagnostic performance (sensitivity, 94%; specificity, 85.7%; PRL, 6.58; and NLR, 0.07) as compared with the best RNFL, best ONH, and best and-logic combination (minimum GCIPL and inferior quadrant RNFL; sensitivity, 64%; specificity, 100%; PLR, infinity; and NPR, 0.36). The binary or-logic combination of minimum GCIPL and average RNFL or rim area provides better diagnostic performances than those of and-logic combinations or best single GCIPL, RNFL, or ONH parameters. This finding may be clinically valuable for the diagnosis of early glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Photodynamic therapy (PDT) as a biological modifier

NASA Astrophysics Data System (ADS)

Obochi, Modestus; Tao, Jing-Song; Hunt, David W. C.; Levy, Julia G.

1996-04-01

The capacity of photosensitizers and light to ablate cancerous tissues and unwanted neovasculature constitutes the classical application of photodynamic therapy (PDT). Cell death results from either necrotic or apoptotic processes. The use of photosensitizers and light at doses which do not cause death has been found to affect changes in certain cell populations which profoundly effect their expression of cell surface molecules and secretion of cytokines, thereby altering the functional attributes of the treated cells. Cells of the immune system and the skin may be sensitive to modulation by 'sub-lethal PDT.' Ongoing studies have been conducted to assess, at the molecular level, changes in both lymphocytes and epidermal cells (EC) caused by treatment with low levels of benzoporphyrin derivative monoacid ring A (BPD) (a photosensitizer currently in clinical trials for cancer, psoriasis, endometriosis and age-related macular degeneration) and light. Treatment of skin with BPD and light, at levels which significantly enhanced the length of murine skin allograft acceptance, have been found to down-regulate the expression of Langerhans cell (LC) surface antigen molecules [major histocompatibility complex (MHC) class II and intracellular adhesion molecule (ICAM)-1] and the formation of some cytokines (tumor necrosis factor-alpha (TNF- (alpha) ).

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.

High Resolution Measurement of the Glycolytic Rate

PubMed Central

Bittner, Carla X.; Loaiza, Anitsi; Ruminot, Iván; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutiérrez, Robin; Córdova, Alex; Valdebenito, Rocío; Frommer, Wolf B.; Barros, L. Felipe

2010-01-01

The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

Tracking degradation in lithium iron phosphate batteries using differential thermal voltammetry

NASA Astrophysics Data System (ADS)

Shibagaki, Toshio; Merla, Yu; Offer, Gregory J.

2018-01-01

Diagnosing the state-of-health of lithium ion batteries in-operando is becoming increasingly important for multiple applications. We report the application of differential thermal voltammetry (DTV) to lithium iron phosphate (LFP) cells for the first time, and demonstrate that the technique is capable of diagnosing degradation in a similar way to incremental capacity analysis (ICA). DTV has the advantage of not requiring current and works for multiple cells in parallel, and is less sensitive to temperature introducing errors. Cells were aged by holding at 100% SOC or cycling at 1C charge, 6D discharge, both at an elevated temperature of 45 °C under forced air convection. Cells were periodically characterised, measuring capacity fade, resistance increase (power fade), and DTV fingerprints. The DTV results for both cells correlated well with both capacity and power, suggesting they could be used to diagnose SOH in-operando for both charge and discharge. The DTV peak-to-peak capacity correlated well with total capacity fade for the cycled cell, suggesting that it should be possible to estimate SOC and SOH from DTV for incomplete cycles within the voltage hysteresis region of an LFP cell.

A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests

PubMed Central

2011-01-01

Background Allergic contact dermatitis is an inflammatory skin disease that affects a significant proportion of the population. This disease is caused by an adverse immune response towards chemical haptens, and leads to a substantial economic burden for society. Current test of sensitizing chemicals rely on animal experimentation. New legislations on the registration and use of chemicals within pharmaceutical and cosmetic industries have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization. The aim is to replace animal experiments with in vitro tests displaying a higher predictive power. Results We have developed a novel cell-based assay for the prediction of sensitizing chemicals. By analyzing the transcriptome of the human cell line MUTZ-3 after 24 h stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, we have identified a biomarker signature of 200 genes with potent discriminatory ability. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization. Conclusions A gene signature predicting sensitization, using a human cell line in vitro, has been identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests. PMID:21824406

Modulating cell-to-cell variability and sensitivity to death ligands by co-drugging

NASA Astrophysics Data System (ADS)

Flusberg, Deborah A.; Sorger, Peter K.

2013-06-01

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) holds promise as an anti-cancer therapeutic but efficiently induces apoptosis in only a subset of tumor cell lines. Moreover, even in clonal populations of responsive lines, only a fraction of cells dies in response to TRAIL and individual cells exhibit cell-to-cell variability in the timing of cell death. Fractional killing in these cell populations appears to arise not from genetic differences among cells but rather from differences in gene expression states, fluctuations in protein levels and the extent to which TRAIL-induced death or survival pathways become activated. In this study, we ask how cell-to-cell variability manifests in cell types with different sensitivities to TRAIL, as well as how it changes when cells are exposed to combinations of drugs. We show that individual cells that survive treatment with TRAIL can regenerate the sensitivity and death-time distribution of the parental population, demonstrating that fractional killing is a stable property of cell populations. We also show that cell-to-cell variability in the timing and probability of apoptosis in response to treatment can be tuned using combinations of drugs that together increase apoptotic sensitivity compared to treatment with one drug alone. In the case of TRAIL, modulation of cell-to-cell variability by co-drugging appears to involve a reduction in the threshold for mitochondrial outer membrane permeabilization.

Ability of primary auditory cortical neurons to detect amplitude modulation with rate and temporal codes: neurometric analysis

PubMed Central

Johnson, Jeffrey S.; Yin, Pingbo; O'Connor, Kevin N.

2012-01-01

Amplitude modulation (AM) is a common feature of natural sounds, and its detection is biologically important. Even though most sounds are not fully modulated, the majority of physiological studies have focused on fully modulated (100% modulation depth) sounds. We presented AM noise at a range of modulation depths to awake macaque monkeys while recording from neurons in primary auditory cortex (A1). The ability of neurons to detect partial AM with rate and temporal codes was assessed with signal detection methods. On average, single-cell synchrony was as or more sensitive than spike count in modulation detection. Cells are less sensitive to modulation depth if tested away from their best modulation frequency, particularly for temporal measures. Mean neural modulation detection thresholds in A1 are not as sensitive as behavioral thresholds, but with phase locking the most sensitive neurons are more sensitive, suggesting that for temporal measures the lower-envelope principle cannot account for thresholds. Three methods of preanalysis pooling of spike trains (multiunit, similar to convergence from a cortical column; within cell, similar to convergence of cells with matched response properties; across cell, similar to indiscriminate convergence of cells) all result in an increase in neural sensitivity to modulation depth for both temporal and rate codes. For the across-cell method, pooling of a few dozen cells can result in detection thresholds that approximate those of the behaving animal. With synchrony measures, indiscriminate pooling results in sensitive detection of modulation frequencies between 20 and 60 Hz, suggesting that differences in AM response phase are minor in A1. PMID:22422997

Inhibition by 6-mercaptopurine of purine phosphoribosyltransferases from Ehrlich ascites-tumour cells that are resistant to this drug

PubMed Central

Atkinson, M. R.; Murray, A. W.

1965-01-01

1. A strain of Ehrlich ascites-tumour cells that showed little inhibition of growth in the presence of 6-mercaptopurine accumulated less than 5% as much 6-thioinosine 5′-phosphate in vivo, in the presence of 6-mercaptopurine, as did the sensitive strain from which it was derived. 2. Specific activities of the phosphoribosyltransferases that convert adenine, guanine, hypoxanthine and 6-mercaptopurine into AMP, GMP, IMP and 6-thioinosine 5′-phosphate were similar in extracts of the resistant and the sensitive cells. 3. As found previously with sensitive cells, 6-mercaptopurine is a competitive inhibitor of guanine phosphoribosyltransferase and hypoxanthine phosphoribosyltransferase from the resistant cells and does not inhibit the adenine phosphoribosyltransferase from these cells. Michaelis constants and inhibitor constants of the purine phosphoribosyltransferases from resistant cells did not differ significantly from those measured with the corresponding enzymes from sensitive cells. 4. Resistance to 6-mercaptopurine in this case is probably not due to qualitative or quantitative changes in these transferases. PMID:14342251

Real-space observation of unbalanced charge distribution inside a perovskite-sensitized solar cell.

PubMed

Bergmann, Victor W; Weber, Stefan A L; Javier Ramos, F; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Li, Dan; Domanski, Anna L; Lieberwirth, Ingo; Ahmad, Shahzada; Berger, Rüdiger

2014-09-22

Perovskite-sensitized solar cells have reached power conversion efficiencies comparable to commercially available solar cells used for example in solar farms. In contrast to silicon solar cells, perovskite-sensitized solar cells can be made by solution processes from inexpensive materials. The power conversion efficiency of these cells depends substantially on the charge transfer at interfaces. Here we use Kelvin probe force microscopy to study the real-space cross-sectional distribution of the internal potential within high efficiency mesoscopic methylammonium lead tri-iodide solar cells. We show that the electric field is homogeneous through these devices, similar to that of a p-i-n type junction. On illumination under short-circuit conditions, holes accumulate in front of the hole-transport layer as a consequence of unbalanced charge transport in the device. After light illumination, we find that trapped charges remain inside the active device layers. Removing these traps and the unbalanced charge injection could enable further improvements in performance of perovskite-sensitized solar cells.

Development of cytotoxicity-sensitive human cells using overexpression of long non-coding RNAs.

PubMed

Tani, Hidenori; Torimura, Masaki

2015-05-01

Biosensors using live cells are analytical devices that have the advantage of being highly sensitive for their targets. Although attention has primarily focused on reporter gene assays using functional promoters, cell viability assays are still efficient. We focus on long non-coding RNAs (lncRNAs) that are involved in the molecular mechanisms associated with responses to cellular stresses as a new biological material. Here we have developed human live cells transfected with lncRNAs that can be used as an intelligent sensor of cytotoxicity for a broad range of environmental stresses. We identified three lncRNAs (GAS5, IDI2-AS1, and SNHG15) that responded to cycloheximide in HEK293 cells. Overexpression of these lncRNAs sensitized human cells to cell death in response to various stresses (cycloheximide, ultraviolet irradiation, mercury II chloride, or hydrogen peroxide). In particular, dual lncRNA (GAS5 plus IDI2-AS1, or GAS5 plus SNHG15) overexpression sensitized cells to cell death by more cellular stresses. We propose a method for highly sensitive biosensors using overexpression of lncRNAs that can potentially measure the cytotoxicity signals of various environmental stresses. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Sensitization of human carcinoma cells to alkylating agents by small interfering RNA suppression of 3-alkyladenine-DNA glycosylase.

PubMed

Paik, Johanna; Duncan, Tod; Lindahl, Tomas; Sedgwick, Barbara

2005-11-15

One of the major cytotoxic lesions generated by alkylating agents is DNA 3-alkyladenine, which can be excised by 3-alkyladenine DNA glycosylase (AAG). Inhibition of AAG may therefore result in increased cellular sensitivity to chemotherapeutic alkylating agents. To investigate this possibility, we have examined the role of AAG in protecting human tumor cells against such agents. Plasmids that express small interfering RNAs targeted to two different regions of AAG mRNA were transfected into HeLa cervical carcinoma cells and A2780-SCA ovarian carcinoma cells. Stable derivatives of both cell types with low AAG protein levels were sensitized to alkylating agents. Two HeLa cell lines with AAG protein levels reduced by at least 80% to 90% displayed a 5- to 10-fold increase in sensitivity to methyl methanesulfonate, N-methyl-N-nitrosourea, and the chemotherapeutic drugs temozolomide and 1,3-bis(2-chloroethyl)-1-nitrosourea. These cells showed no increase in sensitivity to UV light or ionizing radiation. After treatment with methyl methanesulfonate, AAG knockdown HeLa cells were delayed in S phase but accumulated in G2-M. Our data support the hypothesis that ablation of AAG activity in human tumor cells may provide a useful strategy to enhance the efficacy of current chemotherapeutic regimens that include alkylating agents.

Ubc9 is required for damage-tolerance and damage-induced interchromosomal homologous recombination in S. cerevisiae.

PubMed

Maeda, Daisuke; Seki, Masayuki; Onoda, Fumitoshi; Branzei, Dana; Kawabe, Yoh-Ichi; Enomoto, Takemi

2004-03-04

Ubc9 is an enzyme involved in the conjugation of small ubiquitin related modifier (SUMO) to target proteins. A Saccharomyces cerevisiae ubc9 temperature sensitive (ts) mutant showed higher sensitivity to various DNA damaging agents such as methylmethanesulfonate (MMS) and UV at a semi-permissive temperature than wild-type cells. The sensitivity of ubc9ts cells was not suppressed by the introduction of a mutated UBC9 gene, UBC9-C93S, whose product is unable to covalently bind to SUMO and consequently fails to conjugate SUMO to target proteins. Diploid ubc9ts cells were more sensitive to various DNA damaging agents than haploid ubc9ts cells suggesting the involvement of homologous recombination in the sensitivity of ubc9ts cells. The frequency of interchromosomal recombination between heteroalleles, his1-1/his1-7 loci, in wild-type cells was remarkably increased upon exposure to MMS or UV. Although the frequency of spontaneous interchromosomal recombination between the heteroalleles in ubc9ts cells was almost the same as that of wild-type cells, no induction of interchromosomal recombination was observed in ubc9ts cells upon exposure to MMS or UV. Copyright 2003 Elsevier B.V.

Influence of polar solvents on photovoltaic performance of Monascusred dye-sensitized solar cell

NASA Astrophysics Data System (ADS)

Lee, Jae Wook; Kim, Tae Young; Ko, Hyun Seok; Han, Shin; Lee, Suk-Ho; Park, Kyung Hee

Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from Monascus red pigment as a sensitizer. In this work, we studied the adsorption characteristics for harvesting sunlight and the electrochemical behavior for electron transfer in Monascus red DSSC using different solvents. The effect of polar aprotic and protic solvents including water, ethanol, and dimethylsulfoxide (DMSO) used in the sensitization process was investigated for the improvement in conversion efficiency of a cell. As for the Monascus red dye-sensitized electrode in DMSO solvent, the solar cell yields a short-circuit current density (Jsc) of 1.23 mA/cm2, a photovoltage (Voc) of 0.75 V, and a fill factor of 0.72, corresponding to an energy conversion efficiency (η) of 0.66%.

Improvement of the antiproliferative effect of rapamycin on tumor cell lines by poly (monomethylitaconate)-based pH-sensitive, plasma stable liposomes.

PubMed

Ghanbarzadeh, Saeed; Arami, Sanam; Pourmoazzen, Zhaleh; Khorrami, Arash

2014-03-01

pH-responsive polymers produce liposomes with pH-sensitive property which can release their encapsulated drug under mild acidic conditions found inside the cellular endosomes, inflammatory tissues and cancerous cells. The aim of this study was preparing pH-sensitive and plasma stable liposomes in order to enhance the selectivity and antiproliferative effect of Rapamycin. In the present study we used PEG-poly (monomethylitaconate)-CholC6 (PEG-PMMI-CholC6) copolymer and Oleic acid (OA) to induce pH-sensitive property in Rapamycin liposomes. pH-sensitive liposomal formulations bearing copolymer PEG-PMMI-CholC6 and OA were characterized in regard to physicochemical stability, pH-responsiveness and stability in human plasma. The ability of pH-sensitive liposomes in enhancing the cytotoxicity of Rapamycin was evaluated in vitro by using colon cancer cell line (HT-29) and compared with its cytotoxicity on human umbilical vein endothelial cell (HUVEC) line. Both formulations were found to release their contents under mild acidic conditions rapidly. However, unlike OA-based liposomes, the PEG-PMMI-CholC6 bearing liposomes preserved their pH-sensitivity in plasma. Both types of pH-sensitive Rapamycin-loaded liposomes exhibited high physicochemical stability and could deliver antiproliferative agent into HT-29 cells much more efficiently in comparison with conventional liposomes. Conversely, the antiproliferative effect of pH-sensitive liposomes on HUVEC cell line was less than conventional liposomes. This study showed that both OA and PEG-PMMI-CholC6-based vesicles could submit pH-sensitive property, however, only PEG-PMMI-CholC6-based liposomes could preserve pH-sensitive property after incubation in plasma. As a result pH-sensitive PEG-PMMI-CholC6-based liposomal formulation can improve the selectivity, stability and antiproliferative effect of Rapamycin. Copyright © 2014 Elsevier B.V. All rights reserved.

RB1 status in triple negative breast cancer cells dictates response to radiation treatment and selective therapeutic drugs.

PubMed

Robinson, Tyler J W; Liu, Jeff C; Vizeacoumar, Frederick; Sun, Thomas; Maclean, Neil; Egan, Sean E; Schimmer, Aaron D; Datti, Alessandro; Zacksenhaus, Eldad

2013-01-01

Triple negative breast cancer (TNBC) includes basal-like and claudin-low subtypes for which only chemotherapy and radiation therapy are currently available. The retinoblastoma (RB1) tumor suppressor is frequently lost in human TNBC. Knockdown of RB1 in luminal BC cells was shown to affect response to endocrine, radiation and several antineoplastic drugs. However, the effect of RB1 status on radiation and chemo-sensitivity in TNBC cells and whether RB1 status affects response to divergent or specific treatment are unknown. Using multiple basal-like and claudin-low cell lines, we hereby demonstrate that RB-negative TNBC cell lines are highly sensitive to gamma-irradiation, and moderately more sensitive to doxorubicin and methotrexate compared to RB-positive TNBC cell lines. In contrast, RB1 status did not affect sensitivity of TNBC cells to multiple other drugs including cisplatin (CDDP), 5-fluorouracil, idarubicin, epirubicin, PRIMA-1(met), fludarabine and PD-0332991, some of which are used to treat TNBC patients. Moreover, a non-biased screen of ∼3400 compounds, including FDA-approved drugs, revealed similar sensitivity of RB-proficient and -deficient TNBC cells. Finally, ESA(+)/CD24(-/low)/CD44(+) cancer stem cells from RB-negative TNBC lines were consistently more sensitive to gamma-irradiation than RB-positive lines, whereas the effect of chemotherapy on the cancer stem cell fraction varied irrespective of RB1 expression. Our results suggest that patients carrying RB-deficient TNBCs would benefit from gamma-irradiation as well as doxorubicin and methotrexate therapy, but not necessarily from many other anti-neoplastic drugs.

Genetic Influence on Contrast Sensitivity in Middle-Aged Male Twins

PubMed Central

Cronin-Golomb, Alice; Panizzon, Matthew S.; Lyons, Michael J.; Franz, Carol E.; Grant, Michael D.; Jacobson, Kristen C.; Eisen, Seth A.; Laudate, Thomas M.; Kremen, William S.

2007-01-01

Contrast sensitivity is strongly associated with daily functioning among older adults, but the genetic and environmental contributions to this ability are unknown. Using the classical twin method, we addressed this issue by examining contrast sensitivity at five spatial frequencies (1.5–18 cycles per degree) in 718 middle-aged male twins from the Vietnam Era Twin Study of Aging (VETSA). Heritability estimates were modest (14%–38%), whereas individual-specific environmental influences accounted for 62%–86% of the variance. Identifying the types of individual-specific events that impact contrast sensitivity may suggest interventions to modulate this ability and thereby improve overall quality of life as adults age. PMID:17604073

Small-volume cavity cell using hollow optical fiber for Raman scattering-based gas detection

NASA Astrophysics Data System (ADS)

Okita, Y.; Katagiri, T.; Matsuura, Y.

2011-03-01

The highly sensitive Raman cell based on the hollow optical fiber that is suitable for the real-time breath analysis is reported. Hollow optical fiber with inner coating of silver is used as a gas cell and a Stokes light collector. A very small cell whose volume is only 0.4 ml or less enables fast response and real-time measurement of trace gases. To increase the sensitivity the cell is arranged in a cavity which includes of a long-pass filter and a high reflective mirror. The sensitivity of the cavity cell is more than two times higher than that of the cell without cavity.

A cockspur for the DSS cells: Erythrina crista-galli sensitizers

NASA Astrophysics Data System (ADS)

Enciso, Paula; Decoppet, Jean-David; Grätzel, Michael; Wörner, Michael; Cabrerizo, Franco M.; Cerdá, María Fernanda

2017-04-01

Dye sensitized solar cells were assembled employing a mixture of anthocyanins extracted from red ceibo's flowers. At the literature different extraction procedures are reported to extract anthocyanins from natural products and sensitize the cells. In order to compare them, different methods were followed to set the cells under the same conditions. Assembled cells showed very interesting conversion efficiency values, reaching a 0.73% value for extracts purified using C18 column, in open cells under illumination using a solar light simulator, 1 sun, 1.5 AM. Data reported herein prove that anthocyanins obtained from ceibo's flower, after simple further purification, might represent an excellent, cheap and clean alternative for the development of DSS cells.

Allergenic food introduction and risk of childhood atopic diseases.

PubMed

Elbert, Niels J; Kiefte-de Jong, Jessica C; Voortman, Trudy; Nijsten, Tamar E C; de Jong, Nicolette W; Jaddoe, Vincent W V; de Jongste, Johan C; Gerth van Wijk, Roy; Duijts, Liesbeth; Pasmans, Suzanne G M A

2017-01-01

The role of timing and diversity of allergenic food introduction in the development of childhood allergic sensitization and atopic diseases is controversial. To examine whether timing and diversity of allergenic food introduction are associated with allergic sensitization, allergy and eczema in children until age 10 years. This study among 5,202 children was performed in a population-based prospective cohort. Timing (age ≤6 months vs. >6 months) and diversity (0, 1, 2 and ≥3 foods) of allergenic food (cow's milk, hen's egg, peanut, tree nuts, soy and gluten) introduction were assessed by questionnaires at ages 6 and 12 months. At age 10 years, inhalant and food allergic sensitization were measured by skin prick tests, and physician-diagnosed inhalant and food allergy by questionnaire. Data on parental-reported physician-diagnosed eczema were obtained from birth until age 10 years. Children introduced to gluten at age ≤6 months had a decreased risk of eczema (aOR (95% CI): 0.84 (0.72, 0.99)), compared with children introduced to gluten at age >6 months. However, timing of allergenic food introduction was not associated with allergic sensitization or physician-diagnosed allergy. Children introduced to ≥3 allergenic foods at age ≤6 months had a decreased risk of physician-diagnosed inhalant allergy (0.64 (0.42, 0.98)), compared with children not introduced to any allergenic food at age ≤6 months. However, diversity of allergenic food introduction was not associated with allergic sensitization, physician-diagnosed food allergy or eczema. Neither timing nor diversity of allergenic food introduction was consistently associated with childhood allergic sensitization, allergy or eczema.

Synthesis of zinc phthalocyanine with large steric hindrance and its photovoltaic performance for dye-sensitized solar cells.

PubMed

Lin, Li; Peng, Bosi; Shi, Wenye; Guo, Yingying; Li, Renjie

2015-03-28

A zinc phthalocyanine (ZnPc) derivative (Zn-tri-PcNc-8) containing tri-benzonaphtho-condensed porphyrazine with one carboxylic and six diphenylphenoxy peripheral substitutions was designed and synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). For the purpose of extending the absorption spectra while minimizing the formation of ZnPc molecular aggregates, bulky 2,6-diphenylphenoxy groups were used as electron donor moieties, and the carboxylic group as an anchoring group to graft the sensitizer onto the semiconductor. It was found that a TiO2-based solar cell sensitized by Zn-tri-PcNc-8 shows a maximum incident photon-to-current conversion efficiency in the red/near-IR light range (650-750 nm), and a solar cell sensitized at near room temperature (30 °C) for 48 h exhibits the best efficiency (3.01%). The efficiency was much higher than that (1.96%) for a solar cell sensitized by its analogue (Zn-tri-PcNc-2) having one carboxyl and three tert-butyl groups without chenodeoxycholic acid (CDCA), indicating that the introduction of six bulky diphenylphenoxy substitutions with large steric hindrance in the ZnPc macrocycle can effectively suppress the molecular aggregates, thus resulting in an improved conversion efficiency. The present results shed light on an effective solution to adjust the ZnPc property via chemical modification such as changing the "push-pull" effect and adding large steric hindrance substituents to further improve the efficiency of the phthalocyanine-sensitized solar cell.

IL-23 secreted by bronchial epithelial cells contributes to allergic sensitization in asthma model: role of IL-23 secreted by bronchial epithelial cells.

PubMed

Lee, Hyun Seung; Park, Da-Eun; Lee, Ji-Won; Chang, Yuna; Kim, Hye Young; Song, Woo-Jung; Kang, Hye-Ryun; Park, Heung-Woo; Chang, Yoon-Seok; Cho, Sang-Heon

2017-01-01

IL-23 has been postulated to be a critical mediator contributing to various inflammatory diseases. Dermatophagoides pteronyssinus (Der p) is one of the most common inhalant allergens. However, the role of IL-23 in Der p-induced mouse asthma model is not well understood, particularly with regard to the development of allergic sensitization in the airways. The objective of this study was to evaluate roles of IL-23 in Der p sensitization and asthma development. BALB/c mice were repeatedly administered Der p intranasally to develop Der p allergic sensitization and asthma. After Der p local administration, changes in IL-23 expression were examined in lung tissues and primary epithelial cells. Anti-IL-23p19 antibody was given during the Der p sensitization period, and its effects were examined. Effects of anti-IL-23p19 antibody at bronchial epithelial levels were also examined in vitro. The expression of IL-23 at bronchial epithelial layers was increased after Der p local administration in mouse. In Der p-induced mouse models, anti-IL-23p19 antibody treatment during allergen sensitization significantly diminished Der p allergic sensitization and several features of allergic asthma including the production of Th2 cytokines and the population of type 2 innate lymphoid cells in lungs. The activation of dendritic cells in lung-draining lymph nodes was also reduced by anti-IL-23 treatment. In murine lung alveolar type II-like epithelial cell line (MLE-12) cells, IL-23 blockade prevented cytokine responses to Der p stimulation, such as IL-1α, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-33, and also bone marrow-derived dendritic cell activation. In conclusion, IL-23 is another important bronchial epithelial cell-driven cytokine which may contribute to the development of house dust mite allergic sensitization and asthma. Copyright © 2017 the American Physiological Society.