Iodinated Contrast Media Can Induce Long-Lasting Oxidative Stress in Hemodialysis Patients

PubMed Central

Hwang, Seun Deuk; Kim, Yoon Ji; Lee, Sang Heun; Cho, Deok Kyu; Cho, Yun Hyeong; Moon, Sung Jin; Lee, Sang Choel

2013-01-01

Purpose Due to their comorbidities, dialysis patients have many chances to undergo radiologic procedures using iodinated contrast media. We aimed to assess time-sequenced blood oxidative stress level after contrast exposure in hemodialysis (HD) patients compared to those in the non-dialysis population. Materials and Methods We included 21 anuric HD patients [HD-coronary angiography (CAG) group] and 23 persons with normal renal function (nonHD-CAG group) scheduled for CAG, and assessed 4 oxidative stress markers [advanced oxidation protein products (AOPP); catalase; 8-hydroxydeoxyguanosine; and malondialdehyde] before and after CAG, and subsequently up to 28 days. Results In the nonHD-CAG group, only AOPP increased immediately after CAG and returned to baseline within one day. However, in the HD-CAG group, all four oxidative stress markers were significantly increased starting one day after CAG, and remained elevated longer than those in the nonHD-CAG group. Especially, AOPP level remained elevated for a month after contrast exposure. Conclusion Our study showed that iodinated contrast media induces severe and prolonged oxidative stress in HD patients. PMID:24142649

Effect of Intravenous Administration of Contrast Media on Serum Creatinine Levels in Neonates.

PubMed

Bedoya, Maria A; White, Ammie M; Edgar, J Christopher; Pradhan, Madhura; Raab, Elisabeth L; Meyer, James S

2017-08-01

Purpose To assess the effect of intravenous contrast media on renal function in neonates. Materials and Methods Institutional review board approval was obtained with waiver of consent. Electronic health records from January 2011 to April 2013 were reviewed retrospectively. Measures of renal function were obtained in inpatient neonates who underwent magnetic resonance (MR) imaging or computed tomography (CT) and for whom serum creatinine (Cr) levels were obtained within 72 hours before imaging and at least one time after imaging (>1 day after administration of contrast material). A total of 140 neonates who received contrast material (59 who underwent CT with iohexol or iodixanol and 81 who underwent MR imaging with gadopentetate dimeglumine) were identified. These neonates were frequency matched according to sex, gestational and postnatal age, and preimaging serum Cr levels with neonates who underwent unenhanced MR imaging or CT. Cr levels and glomerular filtration rates (GFRs) were grouped according to when they were obtained (before imaging, 1-2 days after imaging, 3-5 days after imaging, 6-9 days after imaging, 10-45 days after imaging, and more than 45 days after imaging). Serum Cr levels and GFRs for each time period were compared between groups by using hierarchic regressions or χ 2 or Fisher exact tests and with repeated-measures analysis of variance to compare groups on the rate of change in serum Cr levels and GFRs from before to after imaging. Results Cr levels decreased and GFRs increased in both groups from before to after imaging (CT group, P ≤ .01; MR imaging group, P ≤ .01). The neonates who underwent contrast material-enhanced imaging and the neonates who underwent unenhanced imaging showed similar serum Cr levels at all examined time periods. Groups also did not differ in the proportion of neonates with serum Cr levels higher than the reference range (>0.4 mg/dL) at any time point (iodine- [P > .12] or gadolinium-based [P > .13] contrast material). Similar findings were observed for GFRs. None of the neonates developed nephrogenic systemic fibrosis. Conclusion In the absence of known renal failure, neonates receiving standard inpatient care do not appear to be at increased risk for developing renal toxicity due to administration of intravenous iodine- and gadolinium-based contrast material. © RSNA, 2017.

The effects of belongingness on the Simultaneous Lightness Contrast: a virtual reality study.

PubMed

Soranzo, Alessandro; Lugrin, Jean-Luc; Wilson, Christopher J

2013-06-28

Simultaneous Lightness Contrast (SLC) is the phenomenon whereby a grey patch on a dark background appears lighter than an equal patch on a light background. Interestingly, the lightness difference between these patches undergoes substantial augmentation when the two backgrounds are patterned, thereby forming the articulated-SLC display. There are two main interpretations of these phenomena: The mid-level interpretation maintains that the visual system groups the luminance within a set of contiguous frameworks, whilst the high-level one claims that the visual system splits the luminance into separate overlapping layers corresponding to separate physical contributions. This research aimed to test these two interpretations by systematically manipulating the viewing distance and the horizontal distance between the backgrounds of both the articulated and plain SLC displays. An immersive 3D Virtual Reality system was employed to reproduce identical alignment and distances, as well as isolating participants from interfering luminance. Results showed that reducing the viewing distance resulted in increased contrast in both the plain- and articulated-SLC displays and that, increasing the horizontal distance between the backgrounds resulted in decreased contrast in the articulated condition but increased contrast in the plain condition. These results suggest that a comprehensive lightness theory should combine the two interpretations. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Fluorescent Affibody Molecule Administered In Vivo at a Microdose Level Labels EGFR Expressing Glioma Tumor Regions.

PubMed

de Souza, Ana Luiza Ribeiro; Marra, Kayla; Gunn, Jason; Samkoe, Kimberley S; Hoopes, P Jack; Feldwisch, Joachim; Paulsen, Keith D; Pogue, Brian W

2017-02-01

Fluorescence guidance in surgical oncology provides the potential to realize enhanced molecular tumor contrast with dedicated targeted tracers, potentially with a microdose injection level. For most glioma tumors, the blood brain barrier is compromised allowing some exogenous drug/molecule delivery and accumulation for imaging. The aberrant overexpression and/or activation of epidermal growth factor receptor (EGFR) is associated with many types of cancers, including glioblastoma, and so the use of a near-infrared (NIR) fluorescent molecule targeted to the EGFR receptor provides the potential for improving tumor contrast during surgery. Fluorescently labeled affibody molecule (ABY-029) has high EGFR affinity and high potential specificity with reasonably fast plasma clearance. In this study, ABY-29 was evaluated in glioma versus normal brain uptake from intravenous injection at a range of doses, down to a microdose injection level. Nude rats were inoculated with the U251 human glioma cell line in the brain. Tumors were allowed to grow for 3-4 weeks. ABY-029 fluorescence ex vivo imaging of brain slices was acquired at different time points (1-48 h) and varying injection doses from 25 to 122 μg/kg (from human protein microdose equivalent to five times microdose levels). The tumor was most clearly visualized at 1-h post-injection with 8- to 16-fold average contrast relative to normal brain. However, the tumor still could be identified after 48 h. In all cases, the ABY-029 fluorescence appeared to localize preferentially in EGFR-positive regions. Increasing the injected dose from a microdose level to five times, a microdose level increased the signal by 10-fold, and the contrast was from 8 to 16, showing that there was value in doses slightly higher than the microdose restriction. Normal tissue uptake was found to be affected by the tumor size, indicating that edema was a likely factor affecting the expected tumor to normal tissue contrast. These results suggest that the NIR-labeled affibody molecules provide an excellent potential to increase surgical visualization of EGFR-positive tumor regions.

Does the use of an iodine-containing contrast agent to visualise the PICC tip in preterm babies cause hypothyroidism? A randomised controlled trial.

PubMed

Rath, Chandra Prakash; Thomas, Mary; Sullivan, Drew; Kluckow, Martin

2018-05-28

To compare thyroid function tests in preterm neonates (<30 weeks and >48 hour old) exposed to iodine-based contrast with controls and ascertain the certainty of peripherally inserted central catheter (PICC) tip position. Infants requiring a PICC were randomised to receive 0.3 mL of iodine-containing contrast or normal saline. The primary outcome was the difference in thyroid-stimulating hormone (TSH) levels on day 14 post PICC insertion and on day 28 of life. 41 infants were randomised with no significant differences in TSH level (mIU/L) at day 14 post PICC insertion (3.1 vs 2) or on day 28 of life (2.2 vs 1.7). The PICC tip was more easily localised in the contrast group (85% vs 55%). Urinary iodine levels were significantly increased in the contrast-exposed group. Use of contrast did not suppress subsequent thyroid function and helped visualise the PICC tip with more certainty. ACTRN 12614000560695, pre-result. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Molecular Imaging of Vasa Vasorum Neovascularization via DEspR-targeted Contrast-enhanced Ultrasound Micro-imaging in Transgenic Atherosclerosis Rat Model

PubMed Central

Decano, Julius L.; Moran, Anne Marie; Ruiz-Opazo, Nelson; Herrera, Victoria L. M.

2011-01-01

Purpose Given that carotid vasa vasorum neovascularization is associated with increased risk for stroke and cardiac events, the present in vivo study was designed to investigate molecular imaging of carotid artery vasa vasorum neovascularization via target-specific contrast-enhanced ultrasound (CEU) micro-imaging. Procedures Molecular imaging was performed in male transgenic rats with carotid artery disease and non-transgenic controls using dual endothelin1/VEGFsp receptor (DEspR)-targeted microbubbles (MBD) and the Vevo770 micro-imaging system and CEU imaging software. Results DEspR-targeted CEU-positive imaging exhibited significantly higher contrast intensity signal (CIS)-levels and pre-/post-destruction CIS-differences in seven of 13 transgenic rats, in contrast to significantly lower CIS-levels and differences in control isotype-targeted microbubble (MBC)-CEU imaging (n =8) and in MBD CEU-imaging of five non-transgenic control rats (P<0.0001). Ex vivo immunofluorescence analysis demonstrated binding of MBD to DEspR-positive endothelial cells; and association of DEspR-targeted increased contrast intensity signals with DEspR expression in vasa vasorum neovessel and intimal lesions. In vitro analysis demonstrated dose-dependent binding of MBD to DEspR-positive human endothelial cells with increasing %cells bound and number of MBD per cell, in contrast to MBC or non-labeled microbubbles (P<0.0001). Conclusion In vivo DEspR-targeted molecular imaging detected increased DEspR-expression in carotid artery lesions and in expanded vasa vasorum neovessels in transgenic rats with carotid artery disease. Future studies are needed to determine predictive value for stroke or heart disease in this transgenic atherosclerosis rat model and translational applications. PMID:20972637

Impact of iso-osmolar versus low-osmolar contrast agents on contrast-induced nephropathy and tissue reperfusion in unselected patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention (from the Contrast Media and Nephrotoxicity Following Primary Angioplasty for Acute Myocardial Infarction [CONTRAST-AMI] Trial).

PubMed

Bolognese, Leonardo; Falsini, Giovanni; Schwenke, Carsten; Grotti, Simone; Limbruno, Ugo; Liistro, Francesco; Carrera, Arcangelo; Angioli, Paolo; Picchi, Andrea; Ducci, Kenneth; Pierli, Carlo

2012-01-01

Conflicting data have been reported on the effects of low-osmolar and iso-osmolar contrast media on contrast-induced acute kidney injury (CI-AKI). In particular, no clinical trial has yet focused on the effect of contemporary contrast media on CI-AKI, epicardial flow, and microcirculatory function in patients with ST-segment elevation acute myocardial infarction who undergo primary percutaneous coronary intervention. The Contrast Media and Nephrotoxicity Following Coronary Revascularization by Angioplasty for Acute Myocardial Infarction (CONTRAST-AMI) trial is a prospective, randomized, single-blind, parallel-group, noninferiority study aiming to evaluate the effects of the low-osmolar contrast medium iopromide compared to the iso-osmolar agent iodixanol on CI-AKI and tissue-level perfusion in patients with ST-segment elevation acute myocardial infarction. Four hundred seventy-five consecutive, unselected patients who underwent primary percutaneous coronary intervention were randomized to iopromide (n = 239) or iodixanol (n = 236). All patients received high-dose N-acetylcysteine and hydration. The primary end point was the proportion of patients with serum creatinine (sCr) increases ≥25% from baseline to 72 hours. Secondary end points were Thrombolysis In Myocardial Infarction (TIMI) myocardial perfusion grade, increase in sCr ≥50%, increase in sCr ≥0.5 or ≥1 mg/dl, and 1-month major adverse cardiac events. The primary end point occurred in 10% of the iopromide group and in 13% of the iodixanol group (95% confidence interval -9% to 3%, p for noninferiority = 0.0002). A TIMI myocardial perfusion grade of 0 or 1 was present in 14% of patients in the 2 groups. No differences between the 2 groups were found in any of the secondary analyses of sCr increase. No significant difference in 1-month major adverse cardiac events was found (8% vs 6%, p = 0.37). In conclusion, in a population of unselected patients with ST-segment elevation acute myocardial infarction who underwent primary percutaneous coronary intervention, iopromide was not inferior to iodixanol in the occurrence of CI-AKI; no significant differences were found in terms of tissue-level reperfusion and major adverse cardiac events between the 2 contrast agents. Copyright © 2012 Elsevier Inc. All rights reserved.

Generalized image contrast enhancement technique based on the Heinemann contrast discrimination model

NASA Astrophysics Data System (ADS)

Liu, Hong; Nodine, Calvin F.

1996-07-01

This paper presents a generalized image contrast enhancement technique, which equalizes the perceived brightness distribution based on the Heinemann contrast discrimination model. It is based on the mathematically proven existence of a unique solution to a nonlinear equation, and is formulated with easily tunable parameters. The model uses a two-step log-log representation of luminance contrast between targets and surround in a luminous background setting. The algorithm consists of two nonlinear gray scale mapping functions that have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of the gray-level distribution of the given image, and can be uniquely determined once the previous three are set. Tests have been carried out to demonstrate the effectiveness of the algorithm for increasing the overall contrast of radiology images. The traditional histogram equalization can be reinterpreted as an image enhancement technique based on the knowledge of human contrast perception. In fact, it is a special case of the proposed algorithm.

Effects of contrast on smooth pursuit eye movements.

PubMed

Spering, Miriam; Kerzel, Dirk; Braun, Doris I; Hawken, Michael J; Gegenfurtner, Karl R

2005-05-20

It is well known that moving stimuli can appear to move more slowly when contrast is reduced (P. Thompson, 1982). Here we address the question whether changes in stimulus contrast also affect smooth pursuit eye movements. Subjects were asked to smoothly track a moving Gabor patch. Targets varied in velocity (1, 8, and 15 deg/s), spatial frequency (0.1, 1, 4, and 8 c/deg), and contrast, ranging from just below individual thresholds to maximum contrast. Results show that smooth pursuit eye velocity gain rose significantly with increasing contrast. Below a contrast level of two to three times threshold, pursuit gain, acceleration, latency, and positional accuracy were severely impaired. Therefore, the smooth pursuit motor response shows the same kind of slowing at low contrast that was demonstrated in previous studies on perception.

Lip colour affects perceived sex typicality and attractiveness of human faces.

PubMed

Stephen, Ian D; McKeegan, Angela M

2010-01-01

The luminance contrast between facial features and facial skin is greater in women than in men, and women's use of make-up enhances this contrast. In black-and-white photographs, increased luminance contrast enhances femininity and attractiveness in women's faces, but reduces masculinity and attractiveness in men's faces. In Caucasians, much of the contrast between the lips and facial skin is in redness. Red lips have been considered attractive in women in geographically and temporally diverse cultures, possibly because they mimic vasodilation associated with sexual arousal. Here, we investigate the effects of lip luminance and colour contrast on the attractiveness and sex typicality (masculinity/femininity) of human faces. In a Caucasian sample, we allowed participants to manipulate the colour of the lips in colour-calibrated face photographs along CIELab L* (light--dark), a* (red--green), and b* (yellow--blue) axes to enhance apparent attractiveness and sex typicality. Participants increased redness contrast to enhance femininity and attractiveness of female faces, but reduced redness contrast to enhance masculinity of men's faces. Lip blueness was reduced more in female than male faces. Increased lightness contrast enhanced the attractiveness of both sexes, and had little effect on perceptions of sex typicality. The association between lip colour contrast and attractiveness in women's faces may be attributable to its association with oxygenated blood perfusion indicating oestrogen levels, sexual arousal, and cardiac and respiratory health.

Long-term changes in retinal contrast sensitivity in chicks from frosted occluders and drugs: relations to myopia?

PubMed

Diether, S; Schaeffel, F

1999-07-01

Experiments in animal models have shown that the retinal analyzes the image to identify the position of the plane of focus and fine-tunes the growth of the underlying sclera. It is fundamental to the understanding of the development of refractive errors to know which image features are processed. Since the position of the image plane fluctuates continuously with accommodative status and viewing distance, a meaningful control of refractive development can only occur by an averaging procedure with a long time constant. As a candidate for a retinal signal for enhanced eye growth and myopia we propose the level of contrast adaptation which varies with the average amount of defocus. Using a behavioural paradigm, we have found in chickens (1) that contrast adaptation (CA, here referred to as an increase in contrast sensitivity) occurs at low spatial frequencies (0.2 cyc/deg) already after 1.5 h of wearing frosted goggles which cause deprivation myopia, (2) that CA also occurs with negative lenses (-7.4D) and positive lenses (+6.9D) after 1.5 h, at least if accommodation is paralyzed and, (3) that CA occurs at a retinal level or has, at least, a retinal component. Furthermore, we have studied the effects of atropine and reserpine, which both suppress myopia development, on CA. Quisqualate, which causes retinal degeneration but leaves emmetropization functional, was also tested. We found that both atropine and reserpine increase contrast sensitivity to a level where no further CA could be induced by frosted goggles. Quisqualate increased only the variability of refractive development and of contrast sensitivity. Taken together, CA occurring during extended periods of defocus is a possible candidate for a retinal error signal for myopia development. However, the situation is complicated by the fact that there must be a second image processing mode generating a powerful inhibitory growth signal if the image is in front of the retina, even with poor images (Diether, S., & Schaeffel, F. (1999).

Contextual effects on perceived contrast: figure-ground assignment and orientation contrast.

PubMed

Self, Matthew W; Mookhoek, Aart; Tjalma, Nienke; Roelfsema, Pieter R

2015-02-02

Figure-ground segregation is an important step in the path leading to object recognition. The visual system segregates objects ('figures') in the visual scene from their backgrounds ('ground'). Electrophysiological studies in awake-behaving monkeys have demonstrated that neurons in early visual areas increase their firing rate when responding to a figure compared to responding to the background. We hypothesized that similar changes in neural firing would take place in early visual areas of the human visual system, leading to changes in the perception of low-level visual features. In this study, we investigated whether contrast perception is affected by figure-ground assignment using stimuli similar to those in the electrophysiological studies in monkeys. We measured contrast discrimination thresholds and perceived contrast for Gabor probes placed on figures or the background and found that the perceived contrast of the probe was increased when it was placed on a figure. Furthermore, we tested how this effect compared with the well-known effect of orientation contrast on perceived contrast. We found that figure-ground assignment and orientation contrast produced changes in perceived contrast of a similar magnitude, and that they interacted. Our results demonstrate that figure-ground assignment influences perceived contrast, consistent with an effect of figure-ground assignment on activity in early visual areas of the human visual system. © 2015 ARVO.

Early renal dysfunction after contrast media administration despite prophylactic hydration.

PubMed

Burchardt, Pawel; Guzik, Przemyslaw; Tabaczewski, Piotr; Synowiec, Tomasz; Bogdan, Monika; Faner, Paula; Chmielarz-Sobocińska, Anna; Palasz, Anna

2013-06-01

The actual incidence of renal dysfunction after contrast media administration seems to be underestimated, especially in the context of epidemiological data. There are only few data concerning the monitoring of impaired kidney function within a few hours after iodine contrast medium application. Hence, the purpose of this study is to observe the incidence of early renal function deterioration within 12-18 h after administration of iodine contrast media in patients scheduled for elective coronary angiography, who were intravenously and orally hydrated. In addition, the project aims to reclassify the contrast induced nephropathy phenomenon, by identification of early markers of renal dysfunction. Morphology, electrolytes, blood urea nitrogen (BUN), creatinine, low-density lipoprotein cholesterol, triglycerides, high-density lipoprotein, and total cholesterol levels were assessed with the use of typical laboratory techniques in 319 patients referred for coronary angiography. We demonstrated that early deterioration of renal function in patients 12-18 h after administration of contrast during imaging tests (even when appropriate prophylactic hydration was used), may occurred just as an increase (or no change) of serum creatinine level and BUN level and a decrease of creatinine clearance and glomerular filtration rate. Depending on the parameter, the phenomenon can be found in 13-28 % of all respondents. Early renal function impairment defined as above was almost 2 and 2.22 × 10(3) times (respectively) more frequently observed in our study than contrast induced nephropathy defined by current definitions.

High resolution microendoscopy with structured illumination and Lugol's iodine staining for evaluation of breast cancer architecture

NASA Astrophysics Data System (ADS)

Dobbs, Jessica; Kyrish, Matthew; Krishnamurthy, Savitri; Grant, Benjamin; Kuerer, Henry; Yang, Wei; Tkaczyk, Tomasz; Richards-Kortum, Rebecca

2016-03-01

Intraoperative margin assessment to evaluate resected tissue margins for neoplastic tissue is performed to prevent reoperations following breast-conserving surgery. High resolution microendoscopy (HRME) can rapidly acquire images of fresh tissue specimens, but is limited by low image contrast in tissues with high optical scattering. In this study we evaluated two techniques to reduce out-of-focus light: HRME image acquisition with structured illumination (SI-HRME) and topical application of Lugol's Iodine. Fresh breast tissue specimens from 19 patients were stained with proflavine alone or Lugol's Iodine and proflavine. Images of tissue specimens were acquired using a confocal microscope and an HRME system with and without structured illumination. Images were evaluated based on visual and quantitative assessment of image contrast. The highest mean contrast was measured in confocal images stained with proflavine. Contrast was significantly lower in HRME images stained with proflavine; however, incorporation of structured illumination significantly increased contrast in HRME images to levels comparable to that in confocal images. The addition of Lugol's Iodine did not increase mean contrast significantly for HRME or SI-HRME images. These findings suggest that structured illumination could potentially be used to increase contrast in HRME images of breast tissue for rapid image acquisition.

Contrast Gain Control in Auditory Cortex

PubMed Central

Rabinowitz, Neil C.; Willmore, Ben D.B.; Schnupp, Jan W.H.; King, Andrew J.

2011-01-01

Summary The auditory system must represent sounds with a wide range of statistical properties. One important property is the spectrotemporal contrast in the acoustic environment: the variation in sound pressure in each frequency band, relative to the mean pressure. We show that neurons in ferret auditory cortex rescale their gain to partially compensate for the spectrotemporal contrast of recent stimulation. When contrast is low, neurons increase their gain, becoming more sensitive to small changes in the stimulus, although the effectiveness of contrast gain control is reduced at low mean levels. Gain is primarily determined by contrast near each neuron's preferred frequency, but there is also a contribution from contrast in more distant frequency bands. Neural responses are modulated by contrast over timescales of ∼100 ms. By using contrast gain control to expand or compress the representation of its inputs, the auditory system may be seeking an efficient coding of natural sounds. PMID:21689603

Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images.

PubMed

Gandhamal, Akash; Talbar, Sanjay; Gajre, Suhas; Hani, Ahmad Fadzil M; Kumar, Dileep

2017-04-01

Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images. Copyright © 2017 Elsevier Ltd. All rights reserved.

Diazepam prophylaxis of contrast media-induced seizures during computed tomography of patients with brain metastases

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

Pagani, J.J.; Hayman, L.A.; Bigelow, R.H.

1983-04-01

The effect of 5 mg of intravenous diazepam (Valium) on contrast media-associated seizer incidence was studied in a randomized controlled trial involving 284 patients with known or suspected brain metastases undergoing cerebral computed tomography. Of these patients, 188 were found to have brain metastases, and it is estimated that for this subgroup prophylactic diazepam reduces the risk of contrast-assocated seizure by a factor of 0.26. Seizures occurred in three of 96 patients with metastases on diazepam and in 14 of 92 patients with metastases but without diazepam. Factors related to increased risk of contrast media-associated seizures are: (1) prior seizuremore » history due to brain metatases and/or prior contrast, (2) progressive cerebral metastases, and (3) prior or concurrent brain antineoplastic therapy. Factors not related to an increased risk of these seizures are: (1) contrast media dosage, chemical composition, or osmolarity, (2) computed tomographic appearance of metastases, and (3) type of primary malignancy. Concomitant therapeutic levels of diphenylhydantoin (Dilantin) do not protect completely against contrast media-associated seizures. Pathophysiology of contrast media-associated seizures is discussed in view of the risk factors determined by this study.« less

Atorvastatin attenuates experimental contrast-induced acute kidney injury: a role for TLR4/MyD88 signaling pathway.

PubMed

Yue, Rongzheng; Zuo, Chuan; Zeng, Jing; Su, Baihai; Tao, Ye; Huang, Songmin; Zeng, Rui

2017-11-01

To investigate the protective effect of different atorvastatin doses on contrast-induced acute kidney injury and the related mechanism. Healthy male Sprague-Dawley (SD) rats were randomly divided into the blank control group, experimental control group and different-dose atorvastatin groups. A rat model of contrast-induced acute kidney injury was established. We detected changes in serum creatinine (Scr) and blood urea nitrogen (BUN) before and after model establishment, observed and scored renal tubular injury, analyzed rat renal cell apoptosis, and measure the expression of signal pathway proteins and downstream inflammatory factors. After contrast agent injection, the Scr and BUN levels of the experimental control group were significantly increased, the different doses applied in the atorvastatin group significantly reduced the Scr and BUN levels (p < .05) and ameliorated the contrast-induced acute kidney injury (p < .05) and significantly reduced Toll-like receptor 4 (TLR4), Myeloid differentiation factor 88 (Myd88), and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) protein expression and relative mRNA expression levels (p < .05) and significantly decreased expression levels of downstream inflammatory factors (p < .05). Different atorvastatin doses have protective effects on contrast-induced acute renal tubular injury in rats, possibly by targeting TLR4, suppressing TLR4 expression, regulating the TLR4/Myd88 signaling pathway, and inhibiting the expression of downstream inflammatory factors.

Object detectability at increased ambient lighting conditions.

PubMed

Pollard, Benjamin J; Chawla, Amarpreet S; Delong, David M; Hashimoto, Noriyuki; Samei, Ehsan

2008-06-01

Under typical dark conditions encountered in diagnostic reading rooms, a reader's pupils will contract and dilate as the visual focus intermittently shifts between the high luminance display and the darker background wall, resulting in increased visual fatigue and the degradation of diagnostic performance. A controlled increase of ambient lighting may, however, reduce the severity of these pupillary adjustments by minimizing the difference between the luminance level to which the eyes adapt while viewing an image (L(adp)) and the luminance level of diffusely reflected light from the area surrounding the display (L(s)). Although ambient lighting in reading rooms has conventionally been kept at a minimum to maintain the perceived contrast of film images, proper Digital Imaging and Communications in Medicine (DICOM) calibration of modern medical-grade liquid crystal displays can compensate for minor lighting increases with very little loss of image contrast. This paper describes two psychophysical studies developed to evaluate and refine optimum reading room ambient lighting conditions through the use of observational tasks intended to simulate real clinical practices. The first study utilized the biologic contrast response of the human visual system to determine a range of representative L(adp) values for typical medical images. Readers identified low contrast horizontal objects in circular foregrounds of uniform luminance (5, 12, 20, and 30 cd/m2) embedded within digitized mammograms. The second study examined the effect of increased ambient lighting on the detection of subtle objects embedded in circular foregrounds of uniform luminance (5, 12, and 35 cd/m2) centered within a constant background of 12 cd/m2 luminance. The images were displayed under a dark room condition (1 lux) and an increased ambient lighting level (50 lux) such that the luminance level of the diffusely reflected light from the background wall was approximately equal to the image L(adp) value of 12 cd/m2. Results from the first study demonstrated that observer true positive and false positive detection rates and true positive detection times were considerably better while viewing foregrounds at 12 and 20 cd/m2 than at the other foreground luminance levels. Results from the second study revealed that under increased room illuminance, the average true positive detection rate improved a statistically significant amount from 39.3% to 55.6% at 5 cd/m2 foreground luminance. Additionally, the true positive rate increased from 46.4% to 56.6% at 35 cd/m2 foreground luminance, and decreased slightly from 90.2% to 87.5% at 12 cd/m2 foreground luminance. False positive rates at all foreground luminance levels remained approximately constant with increased ambient lighting. Furthermore, under increased room illuminance, true positive detection times declined at every foreground luminance level, with the most considerable decrease (approximately 500 ms) at the 5 cd/m2 foreground luminance. The first study suggests that L(adp) of typical mammograms lies between 12 and 20 cd/m2, leading to an optimum reading room illuminance of approximately 50-80 lux. Findings from the second study provide psychophysical evidence that ambient lighting may be increased to a level within this range, potentially improving radiologist comfort, without deleterious effects on diagnostic performance.

Tests of the Aversive Summation Hypothesis in Rats: Effects of Restraint Stress on Consummatory Successive Negative Contrast and Extinction in the Barnes Maze

ERIC Educational Resources Information Center

Ortega, Leonardo A.; Prado-Rivera, Mayerli A.; Cardenas-Poveda, D. Carolina; McLinden, Kristina A.; Glueck, Amanda C.; Gutierrez, German; Lamprea, Marisol R.; Papini, Mauricio R.

2013-01-01

The present research explored the effects of restraint stress on two situations involving incentive downshift: consummatory successive negative contrast (cSNC) and extinction of escape behavior in the Barnes maze. First, Experiment 1 confirmed that the restraint stress procedure used in these experiments increased levels of circulating…

Effects of aniracetam on extracellular levels of transmitter amino acids in the hippocampus of the conscious gerbils: an intracranial microdialysis study.

PubMed

Yu, Siming; Cai, Jingxia

2003-03-27

The effects of aniracetam on extracellular amino acid levels in the hippocampus of conscious gerbils, with or without transient cerebral ischemia/reperfusion, were measured by microdialysis and reverse phase-high performance liquid chromatography. Increased extracellular levels of aspartate and glutamate that were observed in the hippocampus of conscious gerbils during transient global forebrain ischemia were reversed by aniracetam. In contrast, the level of extracellular gamma-aminobutyric acid was increased, while taurine was maintained at a higher level than other amino acids by administration of aniracetam (100 mg/kg, p.o.) 60 min before ischemia. Further, in contrast to ischemic animals, administration of aniracetam (100 mg/kg, p.o.) enhanced the release of glutamate and aspartate in the normal gerbil hippocampus. The results suggest that these effects might be due to a partial calcium agonist activity of aniracetam, and that the effects of aniracetam on amino acid levels might be a mechanism of protection against delayed neuronal death in the ischemic hippocampus, thereby improving memory dysfunction induced by ischemia/reperfusion.

Unattended processing of hierarchical pitch variations in spoken sentences.

PubMed

Li, Xiaoqing; Chen, Yiya

2018-05-16

An auditory oddball paradigm was employed to examine the unattended processing of pitch variation which functions to signal hierarchically different levels of meaning contrasts. Four oddball conditions were constructed by varying the pitch contour of critical words embedded in a Mandarin Chinese sentence. Two conditions included lexical-level word meaning contrasts (i.e. TONE condition) and the other two sentence-level information-status contrasts (i.e. ACCENTUATION condition). Both included stimuli with early vs. late acoustic cue divergence points. Results showed that the two early-cue conditions elicited earlier Mismatch Negativities, regardless of their functional hierarchy. The deviant stimuli induced theta-band power increases in the TONE condition but beta-band power decreases in the ACCENTUATIION condition, regardless of the timing of their acoustic cues. These results suggest that, in an unattentive state, the human brain can functionally disentangle hierarchically different levels of pitch variation, and the brain responses to these pitch variations are time-locked to the presence of the acoustic cues. Copyright © 2018. Published by Elsevier Inc.

Objective assessment of chromatic and achromatic pattern adaptation reveals the temporal response properties of different visual pathways.

PubMed

Robson, Anthony G; Kulikowski, Janus J

2012-11-01

The aim was to investigate the temporal response properties of magnocellular, parvocellular, and koniocellular visual pathways using increment/decrement changes in contrast to elicit visual evoked potentials (VEPs). Static achromatic and isoluminant chromatic gratings were generated on a monitor. Chromatic gratings were modulated along red/green (R/G) or subject-specific tritanopic confusion axes, established using a minimum distinct border criterion. Isoluminance was determined using minimum flicker photometry. Achromatic and chromatic VEPs were recorded to contrast increments and decrements of 0.1 or 0.2 superimposed on the static gratings (masking contrast 0-0.6). Achromatic increment/decrement changes in contrast evoked a percept of apparent motion when the spatial frequency was low; VEPs to such stimuli were positive in polarity and largely unaffected by high levels of static contrast, consistent with transient response mechanisms. VEPs to finer achromatic gratings showed marked attenuation as static contrast was increased. Chromatic VEPs to R/G or tritan chromatic contrast increments were of negative polarity and showed progressive attenuation as static contrast was increased, in keeping with increasing desensitization of the sustained responses of the color-opponent visual pathways. Chromatic contrast decrement VEPs were of positive polarity and less sensitive to pattern adaptation. The relative contribution of sustained/transient mechanisms to achromatic processing is spatial frequency dependent. Chromatic contrast increment VEPs reflect the sustained temporal response properties of parvocellular and koniocellular pathways. Cortical VEPs can provide an objective measure of pattern adaptation and can be used to probe the temporal response characteristics of different visual pathways.

A neuroendocrine predisposition for homosexuality in men.

PubMed

Dörner, G; Rohde, W; Stahl, F; Krell, L; Masius, W G

1975-01-01

In male rats, androgen deficiency during a critical hypothalamic organizational period was shown to give rise to a predominantly female-differentiated brain, homosexual behavior, and demonstration of a positive estrogen feedback effect. A positive estrogen feedback effect was also induced in intact homosexual men in contrast to intact heterosexual and bisexual men. Thus in 21 homosexual men an intravenous injection of 20 mg Presomen (Premarin) produced a significant decrease of serum LH levels followed by an increase above initial LH values. In 20 heterosexual and in five bisexual men, by contrast, intravenous estrogen administration, while producing a significant decrease of the serum LH level, was not followed by an increase above the initial LH values. Using a radioimmunoassay, plasma testosterone levels and 24-hr urinary excretions of unconjugated testosterone of adult homosexual men were found to be in the normal range as observed in heterosexual men. This finding suggests that homosexual men possess a predominantly female-differentiated brain which may be activated to homosexual behavior by normal or approximately normal androgen levels in adulthood.

Contrast discrimination, non-uniform patterns and change blindness.

PubMed Central

Scott-Brown, K C; Orbach, H S

1998-01-01

Change blindness--our inability to detect large changes in natural scenes when saccades, blinks and other transients interrupt visual input--seems to contradict psychophysical evidence for our exquisite sensitivity to contrast changes. Can the type of effects described as 'change blindness' be observed with simple, multi-element stimuli, amenable to psychophysical analysis? Such stimuli, composed of five mixed contrast elements, elicited a striking increase in contrast increment thresholds compared to those for an isolated element. Cue presentation prior to the stimulus substantially reduced thresholds, as for change blindness with natural scenes. On one hand, explanations for change blindness based on abstract and sketchy representations in short-term visual memory seem inappropriate for this low-level image property of contrast where there is ample evidence for exquisite performance on memory tasks. On the other hand, the highly increased thresholds for mixed contrast elements, and the decreased thresholds when a cue is present, argue against any simple early attentional or sensory explanation for change blindness. Thus, psychophysical results for very simple patterns cannot straightforwardly predict results even for the slightly more complicated patterns studied here. PMID:9872004

Development and evaluation of a method of calibrating medical displays based on fixed adaptation

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

Sund, Patrik, E-mail: patrik.sund@vgregion.se; Månsson, Lars Gunnar; Båth, Magnus

2015-04-15

Purpose: The purpose of this work was to develop and evaluate a new method for calibration of medical displays that includes the effect of fixed adaptation and by using equipment and luminance levels typical for a modern radiology department. Methods: Low contrast sinusoidal test patterns were derived at nine luminance levels from 2 to 600 cd/m{sup 2} and used in a two alternative forced choice observer study, where the adaptation level was fixed at the logarithmic average of 35 cd/m{sup 2}. The contrast sensitivity at each luminance level was derived by establishing a linear relationship between the ten pattern contrastmore » levels used at every luminance level and a detectability index (d′) calculated from the fraction of correct responses. A Gaussian function was fitted to the data and normalized to the adaptation level. The corresponding equation was used in a display calibration method that included the grayscale standard display function (GSDF) but compensated for fixed adaptation. In the evaluation study, the contrast of circular objects with a fixed pixel contrast was displayed using both calibration methods and was rated on a five-grade scale. Results were calculated using a visual grading characteristics method. Error estimations in both observer studies were derived using a bootstrap method. Results: The contrast sensitivities for the darkest and brightest patterns compared to the contrast sensitivity at the adaptation luminance were 37% and 56%, respectively. The obtained Gaussian fit corresponded well with similar studies. The evaluation study showed a higher degree of equally distributed contrast throughout the luminance range with the calibration method compensated for fixed adaptation than for the GSDF. The two lowest scores for the GSDF were obtained for the darkest and brightest patterns. These scores were significantly lower than the lowest score obtained for the compensated GSDF. For the GSDF, the scores for all luminance levels were statistically separated from the average value; three were lower and two were higher. For the compensated GSDF, three of the scores could not be separated from the average value. Conclusions: An observer study using clinically relevant displays and luminance settings has demonstrated that the calibration of displays according to the GSDF causes the perceived contrast to be unevenly distributed when using displays with a high luminance range. As the luminance range increases, the perceived contrast in the dark and bright regions will be significantly lower than the perceived contrast in the middle of the luminance range. A new calibration method that includes the effect of fixed adaptation was developed and evaluated in an observer study and was found to distribute the contrast of the display more evenly throughout the grayscale than the GSDF.« less

Patterns and drivers of daily bed-level dynamics on two tidal flats with contrasting wave exposure.

PubMed

Hu, Zhan; Yao, Peng; van der Wal, Daphne; Bouma, Tjeerd J

2017-08-02

Short-term bed-level dynamics has been identified as one of the main factors affecting biota establishment or retreat on tidal flats. However, due to a lack of proper instruments and intensive labour involved, the pattern and drivers of daily bed-level dynamics are largely unexplored in a spatiotemporal context. In this study, 12 newly-developed automatic bed-level sensors were deployed for nearly 15 months on two tidal flats with contrasting wave exposure, proving an unique dataset of daily bed-level changes and hydrodynamic forcing. By analysing the data, we show that (1) a general steepening trend exists on both tidal flats, even with contrasting wave exposure and different bed sediment grain size; (2) daily morphodynamics level increases towards the sea; (3) tidal forcing sets the general morphological evolution pattern at both sites; (4) wave forcing induces short-term bed-level fluctuations at the wave-exposed site, but similar effect is not seen at the sheltered site with smaller waves; (5) storms provoke aggravated erosion, but the impact is conditioned by tidal levels. This study provides insights in the pattern and drivers of daily intertidal bed-level dynamics, thereby setting a template for future high-resolution field monitoring programmes and inviting in-depth morphodynamic modelling for improved understanding and predictive capability.

Characterization of the effects of reuptake and hydrolysis inhibition on interstitial endocannabinoid levels in the brain: an in vivo microdialysis study.

PubMed

Wiskerke, Joost; Irimia, Cristina; Cravatt, Benjamin F; De Vries, Taco J; Schoffelmeer, Anton N M; Pattij, Tommy; Parsons, Loren H

2012-05-16

The present experiments employed in vivo microdialysis to characterize the effects of commonly used endocannabinoid clearance inhibitors on basal and depolarization-induced alterations in interstitial endocannabinoid levels in the nucleus accumbens of rat brain. Compounds targeting the putative endocannabinoid transporter and hydrolytic enzymes (FAAH and MAGL) were compared. The transporter inhibitor AM404 modestly enhanced depolarization-induced increases in 2-arachidonoyl glycerol (2-AG) levels but did not alter levels of N-arachidonoyl-ethanolamide (anandamide, AEA). The transport inhibitor UCM707 did not alter dialysate levels of either endocannabinoid. The FAAH inhibitors URB597 and PF-3845 robustly increased AEA levels during depolarization without altering 2-AG levels. The MAGL inhibitor URB602 significantly enhanced depolarization-induced increases in 2-AG, but did not alter AEA levels. In contrast, the MAGL inhibitor JZL184 did not alter 2-AG or AEA levels under any condition tested. Finally, the dual FAAH/MAGL inhibitor JZL195 significantly enhanced depolarization-induced increases in both AEA and 2-AG levels. In contrast to the present observations in rats, prior work in mice has demonstrated a robust JZL184-induced enhancement of depolarization-induced increases in dialysate 2-AG. Thus, to further investigate species differences, additional tests with JZL184, PF-3845, and JZL195 were performed in mice. Consistent with prior reports, JZL184 significantly enhanced depolarization-induced increases in 2-AG without altering AEA levels. PF-3845 and JZL195 produced profiles in mouse dialysates comparable to those observed in rats. These findings confirm that interstitial endocannabinoid levels in the brain can be selectively manipulated by endocannabinoid clearance inhibitors. While PF-3845 and JZL195 produce similar effects in both rats and mice, substantial species differences in JZL184 efficacy are evident, which is consistent with previous studies.

Bird diversity and environmental heterogeneity in North America: A test of the area-heterogeneity trade-off

Treesearch

Rachel Chocron; Curtis H. Flather; Ronen Kadmon

2015-01-01

Aim: Deterministic niche theory predicts that increasing environmental heterogeneity increases species richness. In contrast, a recent stochastic model suggests that heterogeneity has a unimodal effect on species richness since high levels of heterogeneity reduce the effective area available per species, thereby increasing the likelihood of stochastic...

Modeling the effects of contrast enhancement on target acquisition performance

NASA Astrophysics Data System (ADS)

Du Bosq, Todd W.; Fanning, Jonathan D.

2008-04-01

Contrast enhancement and dynamic range compression are currently being used to improve the performance of infrared imagers by increasing the contrast between the target and the scene content, by better utilizing the available gray levels either globally or locally. This paper assesses the range-performance effects of various contrast enhancement algorithms for target identification with well contrasted vehicles. Human perception experiments were performed to determine field performance using contrast enhancement on the U.S. Army RDECOM CERDEC NVESD standard military eight target set using an un-cooled LWIR camera. The experiments compare the identification performance of observers viewing linearly scaled images and various contrast enhancement processed images. Contrast enhancement is modeled in the US Army thermal target acquisition model (NVThermIP) by changing the scene contrast temperature. The model predicts improved performance based on any improved target contrast, regardless of feature saturation or enhancement. To account for the equivalent blur associated with each contrast enhancement algorithm, an additional effective MTF was calculated and added to the model. The measured results are compared with the predicted performance based on the target task difficulty metric used in NVThermIP.

Facial contrast is a cue for perceiving health from the face.

PubMed

Russell, Richard; Porcheron, Aurélie; Sweda, Jennifer R; Jones, Alex L; Mauger, Emmanuelle; Morizot, Frederique

2016-09-01

How healthy someone appears has important social consequences. Yet the visual cues that determine perceived health remain poorly understood. Here we report evidence that facial contrast-the luminance and color contrast between internal facial features and the surrounding skin-is a cue for the perception of health from the face. Facial contrast was measured from a large sample of Caucasian female faces, and was found to predict ratings of perceived health. Most aspects of facial contrast were positively related to perceived health, meaning that faces with higher facial contrast appeared healthier. In 2 subsequent experiments, we manipulated facial contrast and found that participants perceived faces with increased facial contrast as appearing healthier than faces with decreased facial contrast. These results support the idea that facial contrast is a cue for perceived health. This finding adds to the growing knowledge about perceived health from the face, and helps to ground our understanding of perceived health in terms of lower-level perceptual features such as contrast. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Effect of glare on simple reaction time.

PubMed

Aguirre, Rolando C; Colombo, Elisa M; Barraza, José F

2008-07-01

We systematized the study of the effect of glare on reaction time (RT), for visual conditions similar to the ones found during night driving: Mesopic range of adaptation (0.14 cd/m2), glare levels of the order of those produced by car headlights (E(G)=15, 60 lx), suprathreshold luminance contrasts, and a variety of spatial frequencies covering the selected range of visibility (1, 2, 4, and 8 c/deg). We found that for the no-glare situation, RT increases with decreasing contrast and increasing spatial frequency, which agrees with previous findings. When data are plotted as a function of the inverse of contrast, RT varies linearly, with k--the RT-contrast factor of Pieron's law--representing the slope of the lines. The effect of glare on RT is an increase in the slope of these lines. This effect is different for each spatial frequency, which cannot be accounted for in the classic approach considering that glare can be replaced by a single veiling luminance. We show that the effect of glare on RT must be modeled by an equivalent glare luminance that depends on spatial frequency.

Visual and ocular changes associated with exposure to two tertiary amines

PubMed Central

Page, E; Cook, C; Hater, M; Mueller, C; Grote, A; Mortimer, V

2003-01-01

Aims: To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes. Methods: Questionnaires, eye examinations (visual acuity, contrast sensitivity at 2.5% and 1.25% contrast, slit lamp biomicroscopy, and pachymetry), and industrial hygiene monitoring for DMIPA and DMAE were performed over a two week period. Results: Eighty nine per cent of line workers reported having experienced blurry vision while at work in the past 12 months, compared to 12.5% of prime workers. A total of 108 full shift personal breathing zone (PBZ) air samples for the amines were collected. The mean time weighted average (TWA) concentration of DMIPA was significantly higher in the line division than in the prime division, as was the mean TWA concentration for total amines. The mean TWA concentration of DMAE was higher in the prime division than the line division. Higher levels of total amines were associated with increased risk of reporting blurry vision, halo vision, and blue-grey vision. The risk of corneal opacity rose with increasing exposure to total amines. The prevalence of corneal opacity also increased with increasing concentration of total amines. Median corneal thickness increased with increasing grades of corneal opacity. There was a statistically significant relation between total amine concentration and increased risk of reduced bilateral visual acuity and 2.5% contrast sensitivity. Conclusions: Exposure to tertiary amines was associated with blurry, halo, and blue-grey vision, corneal opacity, and decrements in visual acuity and contrast sensitivity at 2.5% contrast. PMID:12499461

Temporal subtraction contrast-enhanced dedicated breast CT

NASA Astrophysics Data System (ADS)

Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.

2016-09-01

The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was implemented using a parallel processing architecture resulting in rapid execution time for the iterative segmentation and intensity-adaptive registration techniques. Characterization of contrast-enhanced lesions is improved using temporal subtraction contrast-enhanced dedicated breast CT. Adaptation of Demons registration forces as a function of contrast-enhancement levels provided a means to accurately align breast tissue in pre- and post-contrast image acquisitions, improving subtraction results. Spatial subtraction of the aligned images yields useful diagnostic information with respect to enhanced lesion morphology and uptake.

WE-D-18A-04: How Iterative Reconstruction Algorithms Affect the MTFs of Variable-Contrast Targets in CT Images

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

Dodge, C.T.; Rong, J.; Dodge, C.W.

2014-06-15

Purpose: To determine how filtered back-projection (FBP), adaptive statistical (ASiR), and model based (MBIR) iterative reconstruction algorithms affect the measured modulation transfer functions (MTFs) of variable-contrast targets over a wide range of clinically applicable dose levels. Methods: The Catphan 600 CTP401 module, surrounded by an oval, fat-equivalent ring to mimic patient size/shape, was scanned on a GE HD750 CT scanner at 1, 2, 3, 6, 12 and 24 mGy CTDIvol levels with typical patient scan parameters: 120kVp, 0.8s, 40mm beam width, large SFOV, 2.5mm thickness, 0.984 pitch. The images were reconstructed using GE's Standard kernel with FBP; 20%, 40% andmore » 70% ASiR; and MBIR. A task-based MTF (MTFtask) was computed for six cylindrical targets: 2 low-contrast (Polystyrene, LDPE), 2 medium-contrast (Delrin, PMP), and 2 high-contrast (Teflon, air). MTFtask was used to compare the performance of reconstruction algorithms with decreasing CTDIvol from 24mGy, which is currently used in the clinic. Results: For the air target and 75% dose savings (6 mGy), MBIR MTFtask at 5 lp/cm measured 0.24, compared to 0.20 for 70% ASiR and 0.11 for FBP. Overall, for both high-contrast targets, MBIR MTFtask improved with increasing CTDIvol and consistently outperformed ASiR and FBP near the system's Nyquist frequency. Conversely, for Polystyrene at 6 mGy, MBIR (0.10) and 70% ASiR (0.07) MTFtask was lower than for FBP (0.18). For medium and low-contrast targets, FBP remains the best overall algorithm for improved resolution at low CTDIvol (1–6 mGy) levels, whereas MBIR is comparable at higher dose levels (12–24 mGy). Conclusion: MBIR improved the MTF of small, high-contrast targets compared to FBP and ASiR at doses of 50%–12.5% of those currently used in the clinic. However, for imaging low- and mediumcontrast targets, FBP performed the best across all dose levels. For assessing MTF from different reconstruction algorithms, task-based MTF measurements are necessary.« less

Contrast media-induced nephropathy: how has Italy contributed in the past 30 years? A systematic review.

PubMed

Sessa, Maurizio; Rossi, Claudia; Mascolo, Annamaria; Scavone, Cristina; di Mauro, Gabriella; Grassi, Roberto; Sportiello, Liberata; Cappabianca, Salvatore; Rafaniello, Concetta

2017-01-01

The use of contrast media in Italy has exponentially increased in the past 3 decades. However, it is unknown whether there has been an increase in clinical research evaluating the risks associated with contrast media usage, especially regarding contrast-induced nephropathy. To fill this gap in knowledge, we performed a systematic review. Meta-analyses, observational studies, and clinical trials assessing contrast media-induced nephropathy as the safety outcome, in which at least one author was affiliated with an Italian university/health care structure, were eligble. Ovid MEDLINE, Ovid Embase, Cochrane Methodology Register, and Web of Science were screened. Men and women exposed to contrast media. In total, 60 original articles were retrieved with an incremental trend between 1990 and 2017. Cohort studies were the most common study design represented. In total, 45 of 60 (75.0%) studies were monocenter studies and 41 of 60 (68.3%) received no funding. In all, 91.7% of studies disclosed no conflicts of interest and 81.7% had no external collaboration. Most of the studies provided a level of evidence of III-2 (32/60; 53.3%) and II (23/60; 38.3%). In total, 50 of 60 studies (83.3%) were published in a scientific journal ranked in the first quartile of their subject area. There was an increased number of studies evaluating contrast-induced nephropathy in Italy during the last three decades. These studies covered procedures to prevent contrast-induced nephropathy or aimed to identify risk factors, biomarkers, and scores, and their related prognosis.

Optimum viewing distance for target acquisition

NASA Astrophysics Data System (ADS)

Holst, Gerald C.

2015-05-01

Human visual system (HVS) "resolution" (a.k.a. visual acuity) varies with illumination level, target characteristics, and target contrast. For signage, computer displays, cell phones, and TVs a viewing distance and display size are selected. Then the number of display pixels is chosen such that each pixel subtends 1 min-1. Resolution of low contrast targets is quite different. It is best described by Barten's contrast sensitivity function. Target acquisition models predict maximum range when the display pixel subtends 3.3 min-1. The optimum viewing distance is nearly independent of magnification. Noise increases the optimum viewing distance.

The contrast media and nephrotoxicity following coronary revascularization by primary angioplasty for acute myocardial infarction study: design and rationale of the CONTRAST-AMI study.

PubMed

Bolognese, Leonardo; Falsini, Giovanni; Grotti, Simone; Limbruno, Ugo; Liistro, Francesco; Carrera, Arcangelo; Angioli, Paolo; Picchi, Andrea; Ducci, Kenneth; Pierli, Carlo

2010-03-01

Contrast-induced acute kidney injury (CI-AKI) is a complex syndrome of acute renal failure occurring after the administration of contrast media and contributing to prolonged hospital stay and mortality. The risk of CI-AKI is higher among patients undergoing primary percutaneous coronary interventions for acute myocardial infarction (AMI), but its clinical relevance in such setting has only been evaluated by small sample size single-center studies and retrospective or observational analyses. Furthermore, whereas high-osmolar contrast media was shown to have direct nephrotoxicity, the role of low-osmolar and iso-osmolar agents is still debated. The CONTRAST-AMI study is a prospective, multicenter, controlled, randomized, single-blind, parallel-group trial, designed to show the noninferiority of the effects of iopromide (low-osmolar) compared with iodixanol (iso-osmolar) contrast media on the incidence of CI-AKI and tissue-level perfusion in patients with AMI. All consecutive patients admitted to participating centers for ST-segment elevation AMI undergoing primary percutaneous coronary intervention will be enrolled. All patients will be treated with high-dose N-acetylcysteine (1200 mg intravenously during the procedure and 1200 mg orally two times daily for the next 48 h after percutaneous coronary intervention) and hydration according to a standardized protocol. The primary endpoint is the proportion of patients with a relative increase in serum creatinine (sCr) of at least 25% from baseline to 72 h after agent administration. The secondary endpoints are absolute and relative increases in sCr of at least 50%, thrombolysis in myocardial infarction (TIMI) perfusion grade, and major adverse cardiac events at 1, 6, and 12 months. The CONTRAST-AMI study will provide information on the effects of iodixanol and iopromide on the incidence of CI-AKI and tissue-level perfusion in patients with AMI.

Contrast volume to creatinine clearance ratio for the prediction of contrast-induced nephropathy in patients undergoing coronary angiography or percutaneous intervention.

PubMed

Barbieri, Lucia; Verdoia, Monica; Marino, Paolo; Suryapranata, Harry; De Luca, Giuseppe

2016-06-01

Contrast-induced nephropathy is a common complication of procedures that are likely to use contrast media. The identification of high-risk patients and preventive optimal hydration are key measures to reduce the incidence of contrast-induced nephropathy. The aim of this study was to evaluate the role of the contrast volume to creatinine clearance ratio (V/CrCl) in the prediction of contrast-induced nephropathy after coronary angiography or percutaneous coronary intervention. Our population consisted of 2308 consecutive patients undergoing coronary angiography and/or percutaneous coronary intervention. The risk of contrast-induced nephropathy was evaluated across quartiles of the V/CrCl. Receiver operating characteristic curves were used to identify the best predictive value. Contrast-induced nephropathy was defined as an absolute increase of 0.5 mg/dL or a relative increase of >25% in creatinine levels 24-48 hours after the procedure. The total incidence of contrast-induced nephropathy was 12.2% and was significantly higher in the fourth quartile (first quartile 8.8%, second quartile 8.9%, third quartile 11.6% and fourth quartile 19.4%; P < 0.001). Using receiver operating characteristic curves we identified V/CrCl ≥ 6.15 as the best discriminant value for the prediction of contrast-induced nephropathy, which occurred in 25.1% of patients with V/CrCl ≥ 6.15 versus 9.7% in patients with V/CrCl < 6.15. These results were also confirmed at multivariate analysis after correction for all baseline confounders (adjusted odds ratio (AOR) (95% confidence interval (CI)) 1.81 (1.19-2.76); P = 0.005). The association between V/CrCl > 6.15 and an increased risk of contrast-induced nephropathy was confirmed among diabetic (11% vs. 27.7%; p P < 0.001) and non-diabetic patients (8.9% vs. 23%; Pp < 0.001), also after correction for all baseline confounders. This is one of the largest studies evaluating the association between the V/CrCl ratio and the risk of contrast-induced nephropathy in patients undergoing coronary angiography or percutaneous coronary intervention. We found that a V/CrCl ratio >6.15 was independently associated with an increased risk of contrast-induced nephropathy. © The European Society of Cardiology 2015.

Oxidative stress and damage in liver, but not in brain, of Fischer 344 rats subjected to dietary iron supplementation with lipid-soluble [(3,5,5-trimethylhexanoyl)ferrocene].

PubMed

Lykkesfeldt, Jens; Morgan, Evan; Christen, Stephan; Skovgaard, Lene Theil; Moos, Torben

2007-01-01

Accumulation of iron probably predisposes the aging brain to progressive neuronal loss. We examined various markers of oxidative stress and damage in the brain and liver of 3- and 24-month-old rats following supplementation with the lipophilic iron derivative [(3,5,5-trimethylhexanoyl)ferrocene] (TMHF), which is capable of crossing the blood-brain barrier. At both ages, iron concentration increased markedly in the liver but failed to increase in the brain. In the liver of TMHF-treated young rats, levels of alpha- and gamma-tocopherols and glutathione (GSH) were also higher. In contrast, the brain displayed unaltered levels of the tocopherols and GSH. Malondialdehyde (MDA) level was also higher in the cerebrospinal fluid (CSF) and the liver but not in the brain. In old rats, the absence of an increase in iron concentration in the brain was reflected by unaltered concentrations of GSH, tocopherols, and MDA as compared to that in untreated rats. In the aging liver, concentrations of GSH and MDA increased with TMHF treatment. Morphological studies revealed unaltered levels of iron, ferritin, heme oxygenase-1 (HO-1), nitrotyrosine (NT), or MDA in the brains of both young and old rats treated with TMHF. In contrast, TMHF treatment increased the level of HO-1 in Kupffer cells, NT in hepatic endothelial cells, and MDA and ferritin in hepatocytes. Although these results demonstrated an increase in the biochemical markers of oxidative stress and damage in response to increasing concentrations of iron in the liver, they also demonstrated that the brain is well protected against dietary iron overload by using iron in a lipid-soluble formulation.

Visual Contrast Sensitivity Improvement by Right Frontal High-Beta Activity Is Mediated by Contrast Gain Mechanisms and Influenced by Fronto-Parietal White Matter Microstructure

PubMed Central

Quentin, Romain; Elkin Frankston, Seth; Vernet, Marine; Toba, Monica N.; Bartolomeo, Paolo; Chanes, Lorena; Valero-Cabré, Antoni

2016-01-01

Behavioral and electrophysiological studies in humans and non-human primates have correlated frontal high-beta activity with the orienting of endogenous attention and shown the ability of the latter function to modulate visual performance. We here combined rhythmic transcranial magnetic stimulation (TMS) and diffusion imaging to study the relation between frontal oscillatory activity and visual performance, and we associated these phenomena to a specific set of white matter pathways that in humans subtend attentional processes. High-beta rhythmic activity on the right frontal eye field (FEF) was induced with TMS and its causal effects on a contrast sensitivity function were recorded to explore its ability to improve visual detection performance across different stimulus contrast levels. Our results show that frequency-specific activity patterns engaged in the right FEF have the ability to induce a leftward shift of the psychometric function. This increase in visual performance across different levels of stimulus contrast is likely mediated by a contrast gain mechanism. Interestingly, microstructural measures of white matter connectivity suggest a strong implication of right fronto-parietal connectivity linking the FEF and the intraparietal sulcus in propagating high-beta rhythmic signals across brain networks and subtending top-down frontal influences on visual performance. PMID:25899709

Quality of abdominal computed tomography angiography: hand versus mechanical intravenous contrast administration in children.

PubMed

Ayyala, Rama S; Zurakowski, David; Lee, Edward Y

2015-11-01

Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent. To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population. We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age. We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand administration of IV contrast agent and 30 (65%; 10.2 ± 4.2 years; range 4-18 years) had mechanical administration of IV contrast agent. All 46 abdominal CT angiography studies were of diagnostic quality based on qualitative evaluation (all ≥3). All abdominal CT angiography studies from both groups showed diagnostic quality of contrast enhancement (>150 HU) at both the celiac axis and the inferior mesenteric artery (IMA) levels. The contrast enhancement of the abdominal aorta was not significantly different between the IV contrast administration methods at either the celiac axis level (360 ± 158 vs. 353 ± 116, P = 0.24) or the IMA level (340 ± 140 vs. 351 ± 90, P = 0.27), adjusting for age. Diagnostic-quality abdominal CT angiography can be achieved using hand administration of IV contrast agent in infants and young children (≤5 years).

Why is Light Text Harder to Read Than Dark Text?

NASA Technical Reports Server (NTRS)

Scharff, Lauren V.; Ahumada, Albert J.

2005-01-01

Scharff and Ahumada (2002, 2003) measured text legibility for light text and dark text. For paragraph readability and letter identification, responses to light text were slower and less accurate for a given contrast. Was this polarity effect (1) an artifact of our apparatus, (2) a physiological difference in the separate pathways for positive and negative contrast or (3) the result of increased experience with dark text on light backgrounds? To rule out the apparatus-artifact hypothesis, all data were collected on one monitor. Its luminance was measured at all levels used, and the spatial effects of the monitor were reduced by pixel doubling and quadrupling (increasing the viewing distance to maintain constant angular size). Luminances of vertical and horizontal square-wave gratings were compared to assess display speed effects. They existed, even for 4-pixel-wide bars. Tests for polarity asymmetries in display speed were negative. Increased experience might develop full letter templates for dark text, while recognition of light letters is based on component features. Earlier, an observer ran all conditions at one polarity and then switched. If dark and light letters were intermixed, the observer might use component features on all trials and do worse on the dark letters, reducing the polarity effect. We varied polarity blocking (completely blocked, alternating smaller blocks, and intermixed blocks). Letter identification responses times showed polarity effects at all contrasts and display resolution levels. Observers were also more accurate with higher contrasts and more pixels per degree. Intermixed blocks increased the polarity effect by reducing performance on the light letters, but only if the randomized block occurred prior to the nonrandomized block. Perhaps observers tried to use poorly developed templates, or they did not work as hard on the more difficult items. The experience hypothesis and the physiological gain hypothesis remain viable explanations.

The Effects of Dietary Carotenoid Supplementation and Retinal Carotenoid Accumulation on Vision-Mediated Foraging in the House Finch

PubMed Central

Toomey, Matthew B.; McGraw, Kevin J.

2011-01-01

Background For many bird species, vision is the primary sensory modality used to locate and assess food items. The health and spectral sensitivities of the avian visual system are influenced by diet-derived carotenoid pigments that accumulate in the retina. Among wild House Finches (Carpodacus mexicanus), we have found that retinal carotenoid accumulation varies significantly among individuals and is related to dietary carotenoid intake. If diet-induced changes in retinal carotenoid accumulation alter spectral sensitivity, then they have the potential to affect visually mediated foraging performance. Methodology/Principal Findings In two experiments, we measured foraging performance of house finches with dietarily manipulated retinal carotenoid levels. We tested each bird's ability to extract visually contrasting food items from a matrix of inedible distracters under high-contrast (full) and dimmer low-contrast (red-filtered) lighting conditions. In experiment one, zeaxanthin-supplemented birds had significantly increased retinal carotenoid levels, but declined in foraging performance in the high-contrast condition relative to astaxanthin-supplemented birds that showed no change in retinal carotenoid accumulation. In experiments one and two combined, we found that retinal carotenoid concentrations predicted relative foraging performance in the low- vs. high-contrast light conditions in a curvilinear pattern. Performance was positively correlated with retinal carotenoid accumulation among birds with low to medium levels of accumulation (∼0.5–1.5 µg/retina), but declined among birds with very high levels (>2.0 µg/retina). Conclusion/Significance Our results suggest that carotenoid-mediated spectral filtering enhances color discrimination, but that this improvement is traded off against a reduction in sensitivity that can compromise visual discrimination. Thus, retinal carotenoid levels may be optimized to meet the visual demands of specific behavioral tasks and light environments. PMID:21747917

Generalized image contrast enhancement technique based on Heinemann contrast discrimination model

NASA Astrophysics Data System (ADS)

Liu, Hong; Nodine, Calvin F.

1994-03-01

This paper presents a generalized image contrast enhancement technique which equalizes perceived brightness based on the Heinemann contrast discrimination model. This is a modified algorithm which presents an improvement over the previous study by Mokrane in its mathematically proven existence of a unique solution and in its easily tunable parameterization. The model uses a log-log representation of contrast luminosity between targets and the surround in a fixed luminosity background setting. The algorithm consists of two nonlinear gray-scale mapping functions which have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of gray scale distribution of the image, and can be uniquely determined once the previous three are given. Tests have been carried out to examine the effectiveness of the algorithm for increasing the overall contrast of images. It can be demonstrated that the generalized algorithm provides better contrast enhancement than histogram equalization. In fact, the histogram equalization technique is a special case of the proposed mapping.

Unloading-induced bone loss was suppressed in gold-thioglucose treated mice.

PubMed

Hino, K; Nifuji, A; Morinobu, M; Tsuji, K; Ezura, Y; Nakashima, K; Yamamoto, H; Noda, M

2006-10-15

Loss of mechanical stress causes bone loss. However, the mechanisms underlying the unloading-induced bone loss are largely unknown. Here, we examined the effects of gold-thioglucose (GTG) treatment, which destroys ventromedial hypothalamus (VMH), on unloading-induced bone loss. Unloading reduced bone volume in control (saline-treated) mice. Treatment with GTG-reduced bone mass and in these GTG-treated mice, unloading-induced reduction in bone mass levels was not observed. Unloading reduced the levels of bone formation rate (BFR) and mineral apposition rate (MAR). GTG treatment also reduced these parameters and under this condition, unloading did not further reduce the levels of BFR and MAR. Unloading increased the levels of osteoclast number (Oc.N/BS) and osteoclast surface (Oc.S/BS). GTG treatment did not alter the basal levels of these bone resorption parameters. In contrast to control, GTG treatment suppressed unloading-induced increase in the levels of Oc.N/BS and Oc.S/BS. Unloading reduced the levels of mRNA expression of the genes encoding osteocalcin, type I collagen and Cbfa1 in bone. In contrast, GTG treatment suppressed such unloading-induced reduction of mRNA expression. Unloading also enhanced the levels of fat mass in bone marrow and mRNA expression of the genes encoding PPARgamma2, C/EBPalpha, and C/EBPbeta in bone. In GTG-treated mice, unloading did not increase fat mass and the levels of fat-related mRNA expression. These results indicated that GTG treatment suppressed unloading-induced alteration in bone loss. 2006 Wiley-Liss, Inc.

Quantitative trait loci that control plasma lipid levels in an F2 intercross between C57BL/6J and DDD.Cg-A(y) inbred mouse strains.

PubMed

Suto, Jun-ichi

2012-04-01

The objectives of this study were to characterize plasma lipid phenotypes and dissect the genetic basis of plasma lipid levels in an obese DDD.Cg-A(y) mouse strain. Plasma triglyceride (TG) levels were significantly higher in the DDD.Cg-A(y) strain than in the B6.Cg-A(y) strain. In contrast, plasma total-cholesterol (CHO) levels did not substantially differ between the two strains. As a rule, the A(y) allele significantly increased TG levels, but did not increase CHO levels. Quantitative trait locus (QTL) analyses for plasma TG and CHO levels were performed in two types of F(2) female mice [F(2)A(y) (F(2) mice carrying the A(y) allele) and F(2) non- A(y) mice (F(2) mice without the A(y) allele)] produced by crossing C57BL/6J females and DDD.Cg-A(y) males. Single QTL scan identified one significant QTL for TG levels on chromosome 1, and two significant QTLs for CHO levels on chromosomes 1 and 8. When the marker nearest to the QTL on chromosome 1 was used as covariates, four additional significant QTLs for CHO levels were identified on chromosomes 5, 6, and 17 (two loci). In contrast, consideration of the agouti locus genotype as covariates did not detect additional QTLs. DDD.Cg-A(y) showed a low CHO level, although it had Apoa2(b), which was a CHO-increasing allele at the Apoa2 locus. This may have been partly due to the presence of multiple QTLs, which were associated with decreased CHO levels, on chromosome 8.

Human hypocretin and melanin-concentrating hormone levels are linked to emotion and social interaction.

PubMed

Blouin, Ashley M; Fried, Itzhak; Wilson, Charles L; Staba, Richard J; Behnke, Eric J; Lam, Hoa A; Maidment, Nigel T; Karlsson, Karl Æ; Lapierre, Jennifer L; Siegel, Jerome M

2013-01-01

The neurochemical changes underlying human emotions and social behaviour are largely unknown. Here we report on the changes in the levels of two hypothalamic neuropeptides, hypocretin-1 and melanin-concentrating hormone, measured in the human amygdala. We show that hypocretin-1 levels are maximal during positive emotion, social interaction and anger, behaviours that induce cataplexy in human narcoleptics. In contrast, melanin-concentrating hormone levels are minimal during social interaction, but are increased after eating. Both peptides are at minimal levels during periods of postoperative pain despite high levels of arousal. Melanin-concentrating hormone levels increase at sleep onset, consistent with a role in sleep induction, whereas hypocretin-1 levels increase at wake onset, consistent with a role in wake induction. Levels of these two peptides in humans are not simply linked to arousal, but rather to specific emotions and state transitions. Other arousal systems may be similarly emotionally specialized.

Nephrotoxicity of high- and low-osmolar contrast media. The protective role of amlodipine in a rat model.

PubMed

Duan, S B; Liu, F Y; Luo, J A; Wu, H W; Liu, R H; Peng, Y M; Yang, X L

2000-09-01

To evaluate the nephrotoxicity of high- and low-osmolar contrast media (HOCM, LOCM) on kidneys in Sprague-Dawley rats. The protective role of amlodipine was studied. Forty rats of both sexes were randomly divided into 5 groups (n=8/group) and glycerine for inducing renal failure was given to all rats except controls. In diatrizoate-injected rats, blood urea nitrogen (BUN) and serum creatinine (SCr) were increased; levels of phospholipase A2 (PLA2), lipid peroxide (LPO) and calcium were also increased in renal tissues. There was no significant difference between LOCM (iohexol) animals and glycerol controls either in the renal levels of PLA2, LPO and calcium or in the levels of BUN and SCr. The histologic changes were milder in the LOCM animals than in the HOCM animals. In the group pretreated with amlodipine, no increase in the levels of BUN or SCr was discovered and the renal content of PLA2, LPO and calcium were significantly lower than in the HOCM group; the renal injuries induced by diatrizoate were alleviated. The HOCM, diatrizoate, was more toxic to rat kidneys than the LOCM iohexol; PLA2, LPO and calcium load played a role in producing renal function impairment induced by diatrizoate meglumine; amlodipine protected the renal tissue from nephrotoxicity induced by diatrizoate.

Overexpression of SnoN/SkiL, amplified at the 3q26.2 locus, in ovarian cancers: A role in ovarian pathogenesis

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

Nanjundan, Meera; Cheng, Kwai Wa; Zhang, Fan

2008-07-18

High-resolution array comparative genomic hybridization of 235 serous epithelial ovarian cancers demonstrated a regional increase at 3q26.2 encompassing SnoN/SkiL, a coregulator of SMAD/TGF{beta} signaling. SnoN RNA transcripts were elevated in {approx}80% of advanced stage serous epithelial ovarian cancers. In both immortalized normal (TIOSE) and ovarian carcinoma cell lines (OVCA), SnoN RNA levels were increased by TGF{beta} stimulation and altered by LY294002 and JNK II inhibitor treatment suggesting that the PI3K and JNK signaling pathways may regulate TGF{beta}-induced increases in SnoN RNA. In TIOSE, SnoN protein levels were reduced 15min post TGF{beta}-stimulation, likely by proteosome-mediated degradation. In contrast, in OVCA, SnoNmore » levels were elevated 3h post-stimulation potentially as a result of inhibition of the proteosome. To elucidate the role of SnoN in ovarian tumorigenesis, we explored the effects of both increasing and decreasing SnoN levels. In both TIOSE and OVCA, SnoN siRNA decreased cell growth between 20 and 50% concurrent with increased p21 levels. In TIOSE, transient expression of SnoN repressed TGF{beta} induction of PAI-1 promoters with little effect on the p21 promoter or resultant cell growth. In contrast to the effects of transient expression, stable expression of SnoN in TIOSE led to growth arrest through induction of senescence. Collectively, these results implicate SnoN levels in multiple roles during ovarian carcinogenesis: promoting cellular proliferation in ovarian cancer cells and as a positive mediator of cell cycle arrest and senescence in non-transformed ovarian epithelial cells.« less

No simple answers for the Finnish and Russian Karelia allergy contrast: Methylation of CD14 gene.

PubMed

Khoo, Siew-Kim; Mäkelä, Mika; Chandler, David; Schultz, En Nee; Jamieson, Sarra E; Goldblatt, Jack; Haahtela, Tari; LeSouëf, Peter; Zhang, Guicheng

2016-11-01

Finnish and Russian Karelian children have a highly contrasting occurrence of asthma and allergy. In these two environments, we studied associations between total serum immunoglobulin E (IgE) with methylation levels in cluster of differentiation 14 (CD14). Five hundred Finnish and Russian Karelian children were included in four groups: Finnish children with high IgE (n = 126) and low IgE (n = 124) as well as Russian children with high IgE (n = 125) and low IgE (n = 125). DNA was extracted from whole blood cells and pyrosequenced. Three CpG sites were selected in the promoter region of CD14. Methylation levels in two of the three CpG sites were higher in the Finnish compared to Russian Karelian children. In the promoter area of CD14, the Finnish compared to Russian children with low IgE had a significant (p < 0.0001) increase in methylation levels at the Amp5Site 2. Likewise, the Finnish compared to Russian children with high IgE had a significant (p = 0.003) increase in methylation levels at the Amp5Site 3. In Russian children with low vs. high IgE, there were significant differences in methylation levels, but this was not the case on the Finnish side. In the regression analysis, adding the methylation variation of CD14 to the model did not explain the higher asthma and allergy risk in the Finnish children. The methylation levels in the promoter region of CD14 gene were higher in the Finnish compared to Russian Karelian children. However, the methylation variation of this candidate gene did not explain the asthma and allergy contrast between these two areas. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Contrast media-induced nephropathy: how has Italy contributed in the past 30 years? A systematic review

PubMed Central

Mascolo, Annamaria; Scavone, Cristina; di Mauro, Gabriella; Grassi, Roberto; Sportiello, Liberata; Cappabianca, Salvatore; Rafaniello, Concetta

2017-01-01

Background and objective The use of contrast media in Italy has exponentially increased in the past 3 decades. However, it is unknown whether there has been an increase in clinical research evaluating the risks associated with contrast media usage, especially regarding contrast-induced nephropathy. To fill this gap in knowledge, we performed a systematic review. Study eligibility criteria Meta-analyses, observational studies, and clinical trials assessing contrast media-induced nephropathy as the safety outcome, in which at least one author was affiliated with an Italian university/health care structure, were eligble. Data sources Ovid MEDLINE, Ovid Embase, Cochrane Methodology Register, and Web of Science were screened. Participants Men and women exposed to contrast media. Results In total, 60 original articles were retrieved with an incremental trend between 1990 and 2017. Cohort studies were the most common study design represented. In total, 45 of 60 (75.0%) studies were monocenter studies and 41 of 60 (68.3%) received no funding. In all, 91.7% of studies disclosed no conflicts of interest and 81.7% had no external collaboration. Most of the studies provided a level of evidence of III-2 (32/60; 53.3%) and II (23/60; 38.3%). In total, 50 of 60 studies (83.3%) were published in a scientific journal ranked in the first quartile of their subject area. Conclusion There was an increased number of studies evaluating contrast-induced nephropathy in Italy during the last three decades. These studies covered procedures to prevent contrast-induced nephropathy or aimed to identify risk factors, biomarkers, and scores, and their related prognosis. PMID:29123405

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

Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu; Garrett, John

Purpose: Statistical model based iterative reconstruction (MBIR) methods have been introduced to clinical CT systems and are being used in some clinical diagnostic applications. The purpose of this paper is to experimentally assess the unique spatial resolution characteristics of this nonlinear reconstruction method and identify its potential impact on the detectabilities and the associated radiation dose levels for specific imaging tasks. Methods: The thoracic section of a pediatric phantom was repeatedly scanned 50 or 100 times using a 64-slice clinical CT scanner at four different dose levels [CTDI{sub vol} =4, 8, 12, 16 (mGy)]. Both filtered backprojection (FBP) and MBIRmore » (Veo{sup ®}, GE Healthcare, Waukesha, WI) were used for image reconstruction and results were compared with one another. Eight test objects in the phantom with contrast levels ranging from 13 to 1710 HU were used to assess spatial resolution. The axial spatial resolution was quantified with the point spread function (PSF), while the z resolution was quantified with the slice sensitivity profile. Both were measured locally on the test objects and in the image domain. The dependence of spatial resolution on contrast and dose levels was studied. The study also features a systematic investigation of the potential trade-off between spatial resolution and locally defined noise and their joint impact on the overall image quality, which was quantified by the image domain-based channelized Hotelling observer (CHO) detectability index d′. Results: (1) The axial spatial resolution of MBIR depends on both radiation dose level and image contrast level, whereas it is supposedly independent of these two factors in FBP. The axial spatial resolution of MBIR always improved with an increasing radiation dose level and/or contrast level. (2) The axial spatial resolution of MBIR became equivalent to that of FBP at some transitional contrast level, above which MBIR demonstrated superior spatial resolution than FBP (and vice versa); the value of this transitional contrast highly depended on the dose level. (3) The PSFs of MBIR could be approximated as Gaussian functions with reasonably good accuracy. (4) Thez resolution of MBIR showed similar contrast and dose dependence. (5) Noise standard deviation assessed on the edges of objects demonstrated a trade-off with spatial resolution in MBIR. (5) When both spatial resolution and image noise were considered using the CHO analysis, MBIR led to significant improvement in the overall CT image quality for both high and low contrast detection tasks at both standard and low dose levels. Conclusions: Due to the intrinsic nonlinearity of the MBIR method, many well-known CT spatial resolution and noise properties have been modified. In particular, dose dependence and contrast dependence have been introduced to the spatial resolution of CT images by MBIR. The method has also introduced some novel noise-resolution trade-off not seen in traditional CT images. While the benefits of MBIR regarding the overall image quality, as demonstrated in this work, are significant, the optimal use of this method in clinical practice demands a thorough understanding of its unique physical characteristics.« less

Statistical model based iterative reconstruction (MBIR) in clinical CT systems. Part II. Experimental assessment of spatial resolution performance.

PubMed

Li, Ke; Garrett, John; Ge, Yongshuai; Chen, Guang-Hong

2014-07-01

Statistical model based iterative reconstruction (MBIR) methods have been introduced to clinical CT systems and are being used in some clinical diagnostic applications. The purpose of this paper is to experimentally assess the unique spatial resolution characteristics of this nonlinear reconstruction method and identify its potential impact on the detectabilities and the associated radiation dose levels for specific imaging tasks. The thoracic section of a pediatric phantom was repeatedly scanned 50 or 100 times using a 64-slice clinical CT scanner at four different dose levels [CTDIvol =4, 8, 12, 16 (mGy)]. Both filtered backprojection (FBP) and MBIR (Veo(®), GE Healthcare, Waukesha, WI) were used for image reconstruction and results were compared with one another. Eight test objects in the phantom with contrast levels ranging from 13 to 1710 HU were used to assess spatial resolution. The axial spatial resolution was quantified with the point spread function (PSF), while the z resolution was quantified with the slice sensitivity profile. Both were measured locally on the test objects and in the image domain. The dependence of spatial resolution on contrast and dose levels was studied. The study also features a systematic investigation of the potential trade-off between spatial resolution and locally defined noise and their joint impact on the overall image quality, which was quantified by the image domain-based channelized Hotelling observer (CHO) detectability index d'. (1) The axial spatial resolution of MBIR depends on both radiation dose level and image contrast level, whereas it is supposedly independent of these two factors in FBP. The axial spatial resolution of MBIR always improved with an increasing radiation dose level and/or contrast level. (2) The axial spatial resolution of MBIR became equivalent to that of FBP at some transitional contrast level, above which MBIR demonstrated superior spatial resolution than FBP (and vice versa); the value of this transitional contrast highly depended on the dose level. (3) The PSFs of MBIR could be approximated as Gaussian functions with reasonably good accuracy. (4) Thez resolution of MBIR showed similar contrast and dose dependence. (5) Noise standard deviation assessed on the edges of objects demonstrated a trade-off with spatial resolution in MBIR. (5) When both spatial resolution and image noise were considered using the CHO analysis, MBIR led to significant improvement in the overall CT image quality for both high and low contrast detection tasks at both standard and low dose levels. Due to the intrinsic nonlinearity of the MBIR method, many well-known CT spatial resolution and noise properties have been modified. In particular, dose dependence and contrast dependence have been introduced to the spatial resolution of CT images by MBIR. The method has also introduced some novel noise-resolution trade-off not seen in traditional CT images. While the benefits of MBIR regarding the overall image quality, as demonstrated in this work, are significant, the optimal use of this method in clinical practice demands a thorough understanding of its unique physical characteristics.

Quantitative assessment of cerebrospinal fluid hydrodynamics using a phase-contrast cine MR image in hydrocephalus.

PubMed

Kim, D S; Choi, J U; Huh, R; Yun, P H; Kim, D I

1999-09-01

This investigation was undertaken to characterize CSF flow at the level of the aqueduct of Sylvius with a phase-contrast cine MR pulse sequence in 28 healthy volunteers. Sixteen patients with obstructive hydrocephalus and 11 patients with normal pressure hydrocephalus (NPH) were investigated with the same sequence before and after CSF diversion. The peak CSF flow velocity and stroke volume in the aqueduct increased significantly in the NPH group and decreased significantly in the obstructive hydrocephalus group. After lumboperitoneal shunting in the NPH group, the retrograde flow of CSF was anterogradely converted and the peak flow velocities decreased somewhat. The clinical diagnosis of NPH was well correlated with the results of cine MRI. After endoscopic III ventriculostomy in the obstructive hydrocephalus group we noted increased CSF flow velocity with markedly increased stroke volume at the prepontine cistern. Phase-contrast cine MR is useful in evaluating CSF dynamics in patients with hyperdynamic aqueductal CSF or aqueductal obstruction.

Contrast invariance of orientation tuning in the lateral geniculate nucleus of the feline visual system.

PubMed

Viswanathan, Sivaram; Jayakumar, Jaikishan; Vidyasagar, Trichur R

2015-09-01

Responses of most neurons in the primary visual cortex of mammals are markedly selective for stimulus orientation and their orientation tuning does not vary with changes in stimulus contrast. The basis of such contrast invariance of orientation tuning has been shown to be the higher variability in the response for low-contrast stimuli. Neurons in the lateral geniculate nucleus (LGN), which provides the major visual input to the cortex, have also been shown to have higher variability in their response to low-contrast stimuli. Parallel studies have also long established mild degrees of orientation selectivity in LGN and retinal cells. In our study, we show that contrast invariance of orientation tuning is already present in the LGN. In addition, we show that the variability of spike responses of LGN neurons increases at lower stimulus contrasts, especially for non-preferred orientations. We suggest that such contrast- and orientation-sensitive variability not only explains the contrast invariance observed in the LGN but can also underlie the contrast-invariant orientation tuning seen at the level of the primary visual cortex. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Improved CT Detection of Acute Herpes Simplex Virus Type 1 Encephalitis Based on a Frequency-Selective Nonlinear Blending: Comparison With MRI.

PubMed

Bongers, Malte Niklas; Bier, Georg; Ditt, Hendrik; Beck, Robert; Ernemann, Ulrike; Nikolaou, Konstantin; Horger, Marius

2016-11-01

The purpose of this study is to compare the diagnostic efficacy of a new CT postprocessing tool based on frequency-selective nonlinear blending (best-contrast CT) with that of standard linear blending of unenhanced head CT in patients with herpes simplex virus type 1 and herpes simplex virus encephalitis (HSE), using FLAIR MRI sequences as the standard of reference. Fifteen consecutive patients (six women and nine men; mean [± SD] age, 60 ± 19 years) with proven HSE (positive polymerase chain reaction results from CSF analysis and the presence of neurologic deficits) were retrospectively enrolled. All patients had undergone head CT and MRI (mean time interval, 2 ± 2 days). After standardized unenhanced head CT scans were read, presets of the best-contrast algorithm were determined (center, 30 HU; delta, 5 HU; slope, 5 nondimensional), and resulting images were analyzed. Contrast enhancement was objectively measured by ROI analysis, comparing contrast-to-noise ratios (CNRs) of unenhanced CT and best-contrast CT. FLAIR and DWI MRI sequences were analyzed, and FLAIR was considered as the standard of reference. For assessment of disease extent, a previously reported 50-point score (HSE score) was used. CNR values for unenhanced head CT (CNR, 5.42 ± 2.77) could be statistically significantly increased using best-contrast CT (CNR, 9.62 ± 4.28) (p = 0.003). FLAIR sequences yielded a median HSE score of 9.0 (range, 6-17) and DWI sequences yielded HSE scores of 6.0 (range, 5-17). By comparison, unenhanced head CT resulted in a median HSE score of 3.5 (range, 1-6). The median best-contrast CT HSE score was 7.5 (range, 6-10). Agreement between FLAIR and unenhanced CT was 54.44%, that between DWI and best-contrast CT was 95.36%, and that between FLAIR and best-contrast CT was 85.21%. The most frequently overseen findings were located at the level of the upper part of the mesencephalon and at the subthalamic or insular level. Frequency-selective nonlinear blending significantly increases contrast and detects brain parenchymal involvement in HSE more sensitively compared with unenhanced CT. The sensitivity of best-contrast CT seems to be equal to that of DWI and almost as good as that of FLAIR.

Maximizing noise energy for noise-masking studies.

PubMed

Jules Étienne, Cédric; Arleo, Angelo; Allard, Rémy

2017-08-01

Noise-masking experiments are widely used to investigate visual functions. To be useful, noise generally needs to be strong enough to noticeably impair performance, but under some conditions, noise does not impair performance even when its contrast approaches the maximal displayable limit of 100 %. To extend the usefulness of noise-masking paradigms over a wider range of conditions, the present study developed a noise with great masking strength. There are two typical ways of increasing masking strength without exceeding the limited contrast range: use binary noise instead of Gaussian noise or filter out frequencies that are not relevant to the task (i.e., which can be removed without affecting performance). The present study combined these two approaches to further increase masking strength. We show that binarizing the noise after the filtering process substantially increases the energy at frequencies within the pass-band of the filter given equated total contrast ranges. A validation experiment showed that similar performances were obtained using binarized-filtered noise and filtered noise (given equated noise energy at the frequencies within the pass-band) suggesting that the binarization operation, which substantially reduced the contrast range, had no significant impact on performance. We conclude that binarized-filtered noise (and more generally, truncated-filtered noise) can substantially increase the energy of the noise at frequencies within the pass-band. Thus, given a limited contrast range, binarized-filtered noise can display higher energy levels than Gaussian noise and thereby widen the range of conditions over which noise-masking paradigms can be useful.

Investigating the procedural variables that determine whether rats will display negative anticipatory contrast or positive induction.

PubMed

Weatherly, Jeffrey N; Nurnberger, Jeri T; Hanson, Brent C

2005-08-31

Previous studies have demonstrated that consumption of a low-valued food substance may decrease if access to a high-valued substance will soon be available (negative anticipatory contrast). Research has also demonstrated that responding for a low-valued reinforcer may increase if responding for a high-valued reinforcer will soon be possible (positive induction). The present experiment employed rats to respond in a procedure similar to that typically used to produce negative anticipatory contrast. The goal was to determine what factors contribute to when a contrast or an induction effect will occur. Based on previous research, the influence of auditory cues, temporal delays, food deprivation, and location of substance delivery were investigated. Auditory cues and temporal delays did little to influence whether subjects increased or decreased their consumption of 1% sucrose when access to 32% sucrose was upcoming. The appearance of contrast or induction was related to level of deprivation, with deprivation promoting induction. Which effect occurred also depended on whether subjects consumed the two substances from one spout in one location (induction) or from two different spouts in two different locations (contrast). The present results help identify the procedural link(s) between these two effects. They also provide insight to why positive induction may occur (i.e., higher-order place conditioning).

Temporal subtraction contrast-enhanced dedicated breast CT

PubMed Central

Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.

2016-01-01

Purpose To develop a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. Methods An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, Intensity Difference Adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using Normalized Cross Correlation (NCC), Symmetric Uncertainty Coefficient (SUC), Normalized Mutual Information (NMI), Mean Square Error (MSE) and Target Registration Error (TRE). Results The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE(0–16%), NCC (0–6%), NMI (0–13%) and TRE (0–34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was implemented using a parallel processing architecture resulting in rapid execution time for the iterative segmentation and intensity-adaptive registration techniques. Conclusion Characterization of contrast-enhanced lesions is improved using temporal subtraction contrast-enhanced dedicated breast CT. Adaptation of Demons registration forces as a function of contrast-enhancement levels provided a means to accurately align breast tissue in pre- and post-contrast image acquisitions, improving subtraction results. Spatial subtraction of the aligned images yields useful diagnostic information with respect to enhanced lesion morphology and uptake. PMID:27494376

Regulation of fish growth hormone transcription.

PubMed

Farchi-Pisanty, O; Hackett, P B; Moav, B

1995-09-01

Regulation of endogenous fish growth hormone transcription was studied using carp pituitaries in vitro. It was demonstrated that thyroid hormone (T3) and 9-cis retinoic acid have increased the steady state levels of growth hormone messenger RNA in pituitary cells, as compared with beta-actin messenger RNA levels. In contrast, estrogen failed to increase growth hormone mRNA levels. The possible involvement of thyroid hormone receptor in pituitary gene expression was demonstrated by in situ localization of both growth hormone mRNA and thyroid hormone receptor mRNA in the pituitaries as early as 4 days after fertilization.

Novel route synthesis of porous and solid gold nanoparticles for investigating their comparative performance as contrast agent in computed tomography scan and effect on liver and kidney function.

PubMed

Aziz, Farooq; Ihsan, Ayesha; Nazir, Aalia; Ahmad, Ishaq; Bajwa, Sadia Zafar; Rehman, Asma; Diallo, Abdoulaye; Khan, Waheed S

2017-01-01

Gold nanoparticles (GNPs) with dimension in the range of 1-100 nm have a prominent role in a number of biomedical applications like imaging, drug delivery, and cancer therapy owing to their unique optical features and biocompatibility. In this work, we report a novel technique for the synthesis of two types of GNPs namely porous gold nanoparticles (PGNPs) and solid gold nanoparticles (SGNPs). PGNPs of size 35 nm were fabricated by reduction of gold (III) solution with lecithin followed by addition of L-ascorbic acid and tri-sodium citrate, whereas SGNPs with a dimension of 28 nm were prepared by reflux method using lecithin as a single reducing agent. Comparative studies using PGNPs (λ max 560 nm) and SGNPs (λ max 548 nm) were conducted for evaluating their use as a contrast agent. These studies reveled that in direct computed tomography scan, PGNPs exhibited brighter contrast (45 HU) than SGNPs (26 HU). To investigate the effect of PGNPs and SGNPs on the liver and kidney profile, male rabbits were intravenously injected with an equal dose of 1 mg/kg weight of PGNPs and SGNPs. The effect on biochemical parameters was evaluated 72 hours after intravenous (IV) injection including liver function profile, renal (kidney) function biomarker, random blood glucose value, and cholesterol level. During one comparison of contrast in CT scan, PGNPs showed significantly enhanced contrast in whole-rabbit and organ CT scan as compared to SGNPs 6 hours after injection. Our findings suggested that the novel PGNPs enhance CT scan image with higher efficacy as compared to SGNPs. The results showed that IV administration of synthesized PGNPs increases the levels of aspartate aminotransferase (AST), alkaline phosphate (ALP), serum creatinine, and blood glucose, whereas that of SGNPs increases the levels of AST, ALP, and blood glucose.

[Effectiveness of nephroprotection by the selection of contrast media used during vascular interventions in patients with chronic renal failure?].

PubMed

Schönefeld, E; Höwler, S; Osada, N; Torsello, G

2011-10-01

The increasing number of endovascular procedures made aware of a kidney disease induced by contrast media (CM). Contrast-induced nephropathy (= CIN) can develop in 0.6-44 % of the treated patients by angiography and / or endovascular intervention. The incidence in high-risk patients ranges from 50 to 70 %. In most cases CIN is inconspicuous and reversible. But pre-existing chronic kidney disease, diabetes mellitus, age and variable different risk factors (e. g., PAOD) can induce irreversible renal impairment. The purpose of the presented trial is to investigate incidence, predictors, and out-come of CIN in chronic renal failure patients using two different CM; one non-ionic isoosmolar -iodixanol and the other non-ionic low-osmolar iopromide. To evaluate the incidence of CIN after endovascular diagnostics and intervention two collectives of 100  patients with chronic renal insufficiency were treated with different contrast media (CM). Inclusion followed prospectively in two collectives. One collective received iopromide (Ultravist™, Bayer Health Care, Lever-kusen, Germany), and the second hundred patients received iodixanol (Visipaque™, Nycomed Amersham, Princeton, New Jersey). Demographics, comorbidities, procedure-related data were completed by serum creatinine levels and GFR (= glomerular filtration rate). Inclusion criteria were a serum creatinine level ≥ 1.5 mg% and a GFR ≤ 60 mL / min. Those parameters were measured twice pre-interventionally, and one time 48-72  hours after the endovascular procedure. Collectives were homogenous and comparable concerning pre-existing risk factors, age and gender. Renal function stayed at a constant level and was independent of contrast medium selection, repectively. Average creatinine levels ranged around 1.77 mg% ± 0.75  standard deviation (SD) pre-interventionally; postinterventional measurement exposed a creatinine level of 1.74 mg% ± 0.74 SD as mean of both collectives. GFR (preinterventional 39.64 mL / min ± 12.48 SD) increased non-significantly to 45.48 mL / min ± 16.82 SD. Pre-existing chronic kidney disease had no effect on renal function parameters; no other risk factors could be evaluated. According to cost-effectiveness a low-osmolar monomeric contrast medium (LOCM) is a sufficient selection, under careful renal function control. © Georg Thieme Verlag KG Stuttgart ˙ New York.

Comparison of low-contrast detectability between two CT reconstruction algorithms using voxel-based 3D printed textured phantoms.

PubMed

Solomon, Justin; Ba, Alexandre; Bochud, François; Samei, Ehsan

2016-12-01

To use novel voxel-based 3D printed textured phantoms in order to compare low-contrast detectability between two reconstruction algorithms, FBP (filtered-backprojection) and SAFIRE (sinogram affirmed iterative reconstruction) and determine what impact background texture (i.e., anatomical noise) has on estimating the dose reduction potential of SAFIRE. Liver volumes were segmented from 23 abdominal CT cases. The volumes were characterized in terms of texture features from gray-level co-occurrence and run-length matrices. Using a 3D clustered lumpy background (CLB) model, a fitting technique based on a genetic optimization algorithm was used to find CLB textures that were reflective of the liver textures, accounting for CT system factors of spatial blurring and noise. With the modeled background texture as a guide, four cylindrical phantoms (Textures A-C and uniform, 165 mm in diameter, and 30 mm height) were designed, each containing 20 low-contrast spherical signals (6 mm diameter at nominal contrast levels of ∼3.2, 5.2, 7.2, 10, and 14 HU with four repeats per signal). The phantoms were voxelized and input into a commercial multimaterial 3D printer (Object Connex 350), with custom software for voxel-based printing (using principles of digital dithering). Images of the textured phantoms and a corresponding uniform phantom were acquired at six radiation dose levels (SOMATOM Flash, Siemens Healthcare) and observer model detection performance (detectability index of a multislice channelized Hotelling observer) was estimated for each condition (5 contrasts × 6 doses × 2 reconstructions × 4 backgrounds = 240 total conditions). A multivariate generalized regression analysis was performed (linear terms, no interactions, random error term, log link function) to assess whether dose, reconstruction algorithm, signal contrast, and background type have statistically significant effects on detectability. Also, fitted curves of detectability (averaged across contrast levels) as a function of dose were constructed for each reconstruction algorithm and background texture. FBP and SAFIRE were compared for each background type to determine the improvement in detectability at a given dose, and the reduced dose at which SAFIRE had equivalent performance compared to FBP at 100% dose. Detectability increased with increasing radiation dose (P = 2.7 × 10 -59 ) and contrast level (P = 2.2 × 10 -86 ) and was higher in the uniform phantom compared to the textured phantoms (P = 6.9 × 10 -51 ). Overall, SAFIRE had higher d' compared to FBP (P = 0.02). The estimated dose reduction potential of SAFIRE was found to be 8%, 10%, 27%, and 8% for Texture-A, Texture-B, Texture-C and uniform phantoms. In all background types, detectability was higher with SAFIRE compared to FBP. However, the relative improvement observed from SAFIRE was highly dependent on the complexity of the background texture. Iterative algorithms such as SAFIRE should be assessed in the most realistic context possible.

Introducing mixotrophy into a biogeochemical model describing an eutrophied coastal ecosystem: The Southern North Sea

NASA Astrophysics Data System (ADS)

Ghyoot, Caroline; Lancelot, Christiane; Flynn, Kevin J.; Mitra, Aditee; Gypens, Nathalie

2017-09-01

Most biogeochemical/ecological models divide planktonic protists between phototrophs (phytoplankton) and heterotrophs (zooplankton). However, a large number of planktonic protists are able to combine several mechanisms of carbon and nutrient acquisition. Not representing these multiple mechanisms in biogeochemical/ecological models describing eutrophied coastal ecosystems can potentially lead to different conclusions regarding ecosystem functioning, especially regarding the success of harmful algae, which are often reported as mixotrophic. This modelling study investigates the implications for trophic dynamics of including 3 contrasting forms of mixotrophy, namely osmotrophy (using alkaline phosphatase activity, APA), non-constitutive mixotrophy (acquired phototrophy by microzooplankton) and also constitutive mixotrophy. The application is in the Southern North Sea, an ecosystem that faced, between 1985 and 2005, a significant increase in the nutrient supply N:P ratio (from 31 to 81 mol N:P). The comparison with a traditional model shows that, when the winter N:P ratio in the Southern North Sea is above 22 molN molP-1 (as occurred from mid-1990s), APA allows a 3-32% increase of annual gross primary production (GPP). In result of the higher GPP, the annual sedimentation increases as well as the bacterial production. By contrast, APA does not affect the export of matter to higher trophic levels because the increased GPP is mainly due to Phaeocystis colonies, which are not grazed by copepods. Under high irradiance, non-constitutive mixotrophy appreciably increases annual GPP, transfer to higher trophic levels, sedimentation, and nutrient remineralisation. In this ecosystem, non-constitutive mixotrophy is also observed to have an indirect stimulating effect on diatoms. Constitutive mixotrophy in nanoflagellates appears to have little influence on this ecosystem functioning. An important conclusion from this work is that contrasting forms of mixotrophy have different impacts on system dynamics and, due to the complex interactions in the ecosystem, their combined effect is not exactly the addition of the effects individually observed. It is thus important to describe such contrasting forms in an appropriate fashion.

Phonological False Memories in Children and Adults: Evidence for a Developmental Reversal

ERIC Educational Resources Information Center

Swannell, Ellen R.; Dewhurst, Stephen A.

2012-01-01

False memories created by the Deese/Roediger-McDermott (DRM) procedure typically show a developmental reversal whereby levels of false recall increase with age. In contrast, false memories produced by phonological lists have been shown to decrease as age increases. In the current study we show that phonological false memories, like semantic false…

Directional sexual selection on chroma and within-pattern colour contrast in Labeotropheus fuelleborni.

PubMed

Pauers, Michael J; McKinnon, Jeffrey S; Ehlinger, Timothy J

2004-12-07

Speciation via intersexual selection on male nuptial colour pattern is thought to have been a major force in promoting the explosive speciation of African haplochromine cichlids, yet there is very little direct empirical evidence of directional preferences within populations. In this study, we used objective spectrophotometry and analyses based on visual physiology to determine whether females of the Katale population of Labeotropheus fuelleborni, a Lake Malawi haplochromine, prefer males that have higher chroma and more within-pattern colour contrast. In paired male preference tests, female Katale L. fuelleborni showed increasing preferences for males with more relatively saturated colours on their flanks. They also showed increasing preferences for males with relatively higher contrast levels among flank elements. This is the first empirical evidence, to our knowledge, for male colour as a directionally sexually selected trait within a haplochromine cichlid population.

Directional sexual selection on chroma and within-pattern colour contrast in Labeotropheus fuelleborni.

PubMed Central

Pauers, Michael J; McKinnon, Jeffrey S; Ehlinger, Timothy J

2004-01-01

Speciation via intersexual selection on male nuptial colour pattern is thought to have been a major force in promoting the explosive speciation of African haplochromine cichlids, yet there is very little direct empirical evidence of directional preferences within populations. In this study, we used objective spectrophotometry and analyses based on visual physiology to determine whether females of the Katale population of Labeotropheus fuelleborni, a Lake Malawi haplochromine, prefer males that have higher chroma and more within-pattern colour contrast. In paired male preference tests, female Katale L. fuelleborni showed increasing preferences for males with more relatively saturated colours on their flanks. They also showed increasing preferences for males with relatively higher contrast levels among flank elements. This is the first empirical evidence, to our knowledge, for male colour as a directionally sexually selected trait within a haplochromine cichlid population. PMID:15801599

Study on polarization image methods in turbid medium

NASA Astrophysics Data System (ADS)

Fu, Qiang; Mo, Chunhe; Liu, Boyu; Duan, Jin; Zhang, Su; Zhu, Yong

2014-11-01

Polarization imaging detection technology in addition to the traditional imaging information, also can get polarization multi-dimensional information, thus improve the probability of target detection and recognition.Image fusion in turbid medium target polarization image research, is helpful to obtain high quality images. Based on visible light wavelength of light wavelength of laser polarization imaging, through the rotation Angle of polaroid get corresponding linear polarized light intensity, respectively to obtain the concentration range from 5% to 10% of turbid medium target stocks of polarization parameters, introduces the processing of image fusion technology, main research on access to the polarization of the image by using different polarization image fusion methods for image processing, discusses several kinds of turbid medium has superior performance of polarization image fusion method, and gives the treatment effect and analysis of data tables. Then use pixel level, feature level and decision level fusion algorithm on three levels of information fusion, DOLP polarization image fusion, the results show that: with the increase of the polarization Angle, polarization image will be more and more fuzzy, quality worse and worse. Than a single fused image contrast of the image be improved obviously, the finally analysis on reasons of the increase the image contrast and polarized light.

Rapid developing of Ektaspeed dental film by increase of temperature.

PubMed

Fredholm, U; Julin, P

1987-01-01

Three rapid developing solutions and one standard solution were tested for contrast and fog with Ektaspeed film at temperatures ranging from 15 degrees to 30 degrees C. Temperatures below 18 degrees C were found to give extremely long developing times, more than 3 minutes with rapid developers, and were not recommended. In the interval between 21 degrees C and 24 degrees C the standard developer needed 3.5-2.5 minutes to get optimum contrast. Two rapid developers needed 1.5 minutes and the fastest 1 minute to get satisfactory contrast throughout this temperature range. A further increase of the temperature gave only a marginal time saving with the rapid solutions and was not considered worthwhile. The relation between developing time and temperature for the rapid developers had a very steep gradient below 21 degrees C, while it levelled out at room temperature. For the standard developer the time/temperature function had a more even gradient from 7.5 minutes at 15 degrees C to 1.5 minutes at 27 degrees C, i.e. an average reduction of 0.5 minute per degree. Between 27 degrees C and 30 degrees C the gradient levelled out. The fog did not increase significantly until at 30 degrees C or at more than double the optimal developing time at room temperature. Recommendations of optimal developing time of Ektaspeed film at different temperatures are given for the four tested developing solutions.

Investigating the dependence of BOLD contrast on oxidative metabolism.

PubMed

Schwarzbauer, C; Heinke, W

1999-03-01

Most functional magnetic resonance imaging (fMRI) studies are based on measuring the changes in the blood oxygenation level-dependent (BOLD) contrast that arise from a complex interplay between cerebral hemodynamics and oxidative metabolism. To separate these effects, we consecutively applied two different stimuli: visual stimulation (black/white checkerboard alternating with a frequency of 8 Hz) and hypercapnia (inspiration of 5% CO2). Changes in cerebral blood flow (deltaCBF) and the effective transverse relaxation time (T2*) were measured in an interleaved manner by combining a previously described spin-labeling technique with BOLD-based fMRI. In six healthy volunteers, T2* was significantly longer during hypercapnia than during visual stimulation, whereas the corresponding deltaCBF values were the same at the given level of significance (P<0.01). This finding is explained by a significant increase in oxygen consumption under visual stimulation. The average T2* changes in the visual cortex related to cerebral hemodynamics and oxidative metabolism were 10.6+/-3.0% and -4.7+/-1.2%, respectively, resulting in a net increase of 5.9+/-2.3%. Although the hemodynamic effect is dominant, the increase in oxidative metabolism gives rise to a significant decrease in BOLD contrast. The calculated average change in the cerebral metabolic rate of oxygen (CMRO2), 4.4+/-1.1% (N = 6), is in excellent agreement with previous results obtained by positron emission tomography.

Immunological, anti-angiogenic and clinical effects of intratumoral interleukin 12 electrogene therapy combined with metronomic cyclophosphamide in dogs with spontaneous cancer: A pilot study.

PubMed

Cicchelero, Laetitia; Denies, Sofie; Vanderperren, Katrien; Stock, Emmelie; Van Brantegem, Leen; de Rooster, Hilde; Sanders, Niek N

2017-08-01

The immunological, anti-angiogenic and clinical effects of metronomic cyclophosphamide and 3 consecutive intratumoral interleukin (IL)-12 gene therapy (electrogene therapy (EGT)) treatments were evaluated in 6 dogs with spontaneous cancer. In all dogs, a decrease in peripheral leukocytes 2 days after IL-12 EGT coincided with erythema and swelling of the tumor. In the tumor, a transient increase in IL-12 levels was measured, whereas a continuous increase in interferon γ (IFNγ) and thrombospondin 1 (TSP-1) were determined in contrast to a continuous decrease in vascular endothelial growth factor (VEGF). In the serum, a transient increase in IL-12 and IL-10 levels were noted in contrast to a transient decrease in VEGF and TSP-1. The treatment resulted in a significant anti-angiogenic effect. Although all primary tumors continued to progress in time, this progression was slower than before treatment according to the contrast-enhanced ultrasound data. Besides the encouraging immunostimulatory and anti-angiogenic effects observed in all dogs we also noticed in 4 out of 6 dogs clinically relevant improvements in quality of life and weight. These results hold great promise for combinatorial strategies of IL-12 EGT and metronomic chemotherapy with conventional antitumor (immuno)therapies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Non-visual spatial tasks reveal increased interactions with stance postural control.

PubMed

Woollacott, Marjorie; Vander Velde, Timothy

2008-05-07

The current investigation aimed to contrast the level and quality of dual-task interactions resulting from the combined performance of a challenging primary postural task and three specific, yet categorically dissociated, secondary central executive tasks. Experiments determined the extent to which modality (visual vs. auditory) and code (non-spatial vs. spatial) specific cognitive resources contributed to postural interference in young adults (n=9) in a dual-task setting. We hypothesized that the different forms of executive n-back task processing employed (visual-object, auditory-object and auditory-spatial) would display contrasting levels of interactions with tandem Romberg stance postural control, and that interactions within the spatial domain would be revealed as most vulnerable to dual-task interactions. Across all cognitive tasks employed, including auditory-object (aOBJ), auditory-spatial (aSPA), and visual-object (vOBJ) tasks, increasing n-back task complexity produced correlated increases in verbal reaction time measures. Increasing cognitive task complexity also resulted in consistent decreases in judgment accuracy. Postural performance was significantly influenced by the type of cognitive loading delivered. At comparable levels of cognitive task difficulty (n-back demands and accuracy judgments) the performance of challenging auditory-spatial tasks produced significantly greater levels of postural sway than either the auditory-object or visual-object based tasks. These results suggest that it is the employment of limited non-visual spatially based coding resources that may underlie previously observed visual dual-task interference effects with stance postural control in healthy young adults.

Metabolic and cardiorespiratory responses of summer flounder Paralichthys dentatus to hypoxia at two temperatures.

PubMed

Capossela, K M; Brill, R W; Fabrizio, M C; Bushnell, P G

2012-08-01

To quantify the tolerance of summer flounder Paralichthys dentatus to episodic hypoxia, resting metabolic rate, oxygen extraction, gill ventilation and heart rate were measured during acute progressive hypoxia at the fish's acclimation temperature (22° C) and after an acute temperature increase (to 30° C). Mean ±s.e. critical oxygen levels (i.e. the oxygen levels below which fish could not maintain aerobic metabolism) increased significantly from 27 ± 2% saturation (2·0 ± 0·1 mg O(2) l(-1)) at 22° C to 39 ± 2% saturation (2·4 ± 0·1 mg O(2) l(-1)) at 30° C. Gill ventilation and oxygen extraction changed immediately with the onset of hypoxia at both temperatures. The fractional increase in gill ventilation (from normoxia to the lowest oxygen level tested) was much larger at 22° C (6·4-fold) than at 30° C (2·7-fold). In contrast, the fractional decrease in oxygen extraction (from normoxia to the lowest oxygen levels tested) was similar at 22° C (1·7-fold) and 30° C (1·5-fold), and clearly smaller than the fractional changes in gill ventilation. In contrast to the almost immediate effects of hypoxia on respiration, bradycardia was not observed until 20 and 30% oxygen saturation at 22 and 30° C, respectively. Bradycardia was, therefore, not observed until below critical oxygen levels. The critical oxygen levels at both temperatures were near or immediately below the accepted 2·3 mg O(2) l(-1) hypoxia threshold for survival, but the increase in the critical oxygen level at 30° C suggests a lower tolerance to hypoxia after an acute increase in temperature. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Cortical Gene Expression After a Conditional Knockout of 67 kDa Glutamic Acid Decarboxylase in Parvalbumin Neurons.

PubMed

Georgiev, Danko; Yoshihara, Toru; Kawabata, Rika; Matsubara, Takurou; Tsubomoto, Makoto; Minabe, Yoshio; Lewis, David A; Hashimoto, Takanori

2016-07-01

In the cortex of subjects with schizophrenia, expression of glutamic acid decarboxylase 67 (GAD67), the enzyme primarily responsible for cortical GABA synthesis, is reduced in the subset of GABA neurons that express parvalbumin (PV). This GAD67 deficit is accompanied by lower cortical levels of other GABA-associated transcripts, including GABA transporter-1, PV, brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B, somatostatin, GABAA receptor α1 subunit, and KCNS3 potassium channel subunit mRNAs. In contrast, messenger RNA (mRNA) levels for glutamic acid decarboxylase 65 (GAD65), another enzyme for GABA synthesis, are not altered. We tested the hypothesis that this pattern of GABA-associated transcript levels is secondary to the GAD67 deficit in PV neurons by analyzing cortical levels of these GABA-associated mRNAs in mice with a PV neuron-specific GAD67 knockout. Using in situ hybridization, we found that none of the examined GABA-associated transcripts had lower cortical expression in the knockout mice. In contrast, PV, BDNF, KCNS3, and GAD65 mRNA levels were higher in the homozygous mice. In addition, our behavioral test battery failed to detect a change in sensorimotor gating or working memory, although the homozygous mice exhibited increased spontaneous activities. These findings suggest that reduced GAD67 expression in PV neurons is not an upstream cause of the lower levels of GABA-associated transcripts, or of the characteristic behaviors, in schizophrenia. In PV neuron-specific GAD67 knockout mice, increased levels of PV, BDNF, and KCNS3 mRNAs might be the consequence of increased neuronal activity secondary to lower GABA synthesis, whereas increased GAD65 mRNA might represent a compensatory response to increase GABA synthesis. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Interrupted infusion of echocardiographic contrast as a basis for accurate measurement of myocardial perfusion: ex vivo validation and analysis procedures.

PubMed

Toledo, Eran; Collins, Keith A; Williams, Ursula; Lammertin, Georgeanne; Bolotin, Gil; Raman, Jai; Lang, Roberto M; Mor-Avi, Victor

2005-12-01

Echocardiographic quantification of myocardial perfusion is based on analysis of contrast replenishment after destructive high-energy ultrasound impulses (flash-echo). This technique is limited by nonuniform microbubble destruction and the dependency on exponential fitting of a small number of noisy time points. We hypothesized that brief interruptions of contrast infusion (ICI) would result in uniform contrast clearance followed by slow replenishment and, thus, would allow analysis from multiple data points without exponential fitting. Electrocardiographic-triggered images were acquired in 14 isolated rabbit hearts (Langendorff) at 3 levels of coronary flow (baseline, 50%, and 15%) during contrast infusion (Definity) with flash-echo and with a 20-second infusion interruption. Myocardial videointensity was measured over time from flash-echo sequences, from which characteristic constant beta was calculated using an exponential fit. Peak contrast inflow rate was calculated from ICI data using analysis of local time derivatives. Computer simulations were used to investigate the effects of noise on the accuracy of peak contrast inflow rate and beta calculations. ICI resulted in uniform contrast clearance and baseline replenishment times of 15 to 25 cardiac cycles. Calculated peak contrast inflow rate followed the changes in coronary flow in all hearts at both levels of reduced flow (P < .05) and had a low intermeasurement variability of 7 +/- 6%. With flash-echo, contrast clearance was less uniform and baseline replenishment times were only 4 to 6 cardiac cycles. beta Decreased significantly only at 15% flow, and had intermeasurement variability of 42 +/- 33%. Computer simulations showed that measurement errors in both perfusion indices increased with noise, but beta had larger errors at higher rates of contrast inflow. ICI provides the basis for accurate and reproducible quantification of myocardial perfusion using fast and robust numeric analysis, and may constitute an alternative to the currently used techniques.

Serum concentrations of fibroblast growth factors 19 and 21 in women with gestational diabetes mellitus: association with insulin resistance, adiponectin, and polycystic ovary syndrome history.

PubMed

Wang, Dongyu; Zhu, Wenjing; Li, Jieming; An, Chongyou; Wang, Zilian

2013-01-01

Fibroblast growth factor 19 (FGF19) and FGF21 are considered to be novel adipokines that improve glucose tolerance and insulin sensitivity. In the current study, we investigated serum FGF19 and FGF21 levels in patients with gestational diabetes mellitus (GDM) and explored their relationships with anthropometric and endocrine parameters. Serum FGF19 and FGF21 levels were determined by enzyme-linked immunosorbent assay (ELISA) in patients with GDM (n = 30) and healthy pregnant controls (n = 60) matched for maternal and gestational age. Serum FGF19 and FGF21 levels were correlated with anthropometric, metabolic, and endocrine parameters. Circulating levels of FGF19 were significantly reduced in patients with GDM relative to healthy pregnant subjects, whereas FGF21 levels were increased in GDM patients. Serum FGF19 levels independently and inversely correlated with insulin resistance (increased homeostasis model assessment of insulin resistance, HOMA-IR) and were positively related to serum adiponectin in both groups. In contrast, serum FGF21 levels independently and positively correlated with insulin resistance and serum triglycerides and were inversely related to serum adiponectin. In addition, in the combined population of both groups, those women with preconception polycystic ovary syndrome (PCOS) history had the lowest levels of FGF19, which were significantly lower than those in GDM patients without PCOS history and those in controls without PCOS history. Circulating FGF19 levels are reduced in GDM patients, in contrast with FGF21 levels. Both serum FGF19 and FGF21 levels are strongly related to insulin resistance and serum levels of adiponectin. Considering the different situation between FGF19 and FGF21, we suggest that reduced serum FGF19 levels could be involved in the pathophysiology of GDM, while increased serum FGF21 levels could be in a compensatory response to this disease.

Benzene metabolite levels in blood and bone marrow of B6C3F{sub 1} mice after low-level exposure

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

Bechtold, W.E.; Strunk, M.R.; Thornton-Manning, J.R.

1995-12-01

Studies at the Inhalation Toxicology Research Institute (ITRI) have explored the species-specific uptake and metabolism of benzene. Results have shown that metabolism is dependent on both dose and route of administration. Of particular interest were shifts in the major metabolic pathways as a function of exposure concentration. In these studies, B6C3F{sub 1} mice were exposed to increasing levels of benzene by either gavage or inhalation. As benzene internal dose increased, the relative amounts of muconic acid and hydroquinone decreased. In contrast, the relative amount of catechol increased with increasing exposure. These results show that the relative levels of toxic metabolitesmore » are a function of exposure level. Based on these results and assuming a linear relationship between exposure concentration and levels of bone marrow metabolites, it would be difficult to detect an elevation of any phenolic metabolites above background after occupational exposures to the OSHA Permissible Exposure Limit of 1 ppm benzene.« less

Transcatheter aortic-valve implantation with one single minimal contrast media injection.

PubMed

Arrigo, Mattia; Maisano, Francesco; Haueis, Sabine; Binder, Ronald K; Taramasso, Maurizio; Nietlispach, Fabian

2015-06-01

Performing transcatheter aortic valve implantation (TAVI) with the use of minimal contrast in patients at high-risk for acute kidney injury (AKI). Contrast-induced nephropathy (CIN) is a major cause of AKI following TAVI and is associated with increased morbidity and mortality. The amount of contrast media used increases the risk for CIN. Computed tomography was omitted during the screening process. For the procedure transfemoral access was default. The self-expanding CoreValve prosthesis was chosen in all patients to minimize the risk of annular rupture in case of oversizing. Valve sizing was based on echocardiography, aortography, calcification on fluoroscopy, as well as weight and height of the patient. A single contrast injection was performed to confirm correct position of the pigtail catheter at the level of the annulus. The pigtail then served as the marker for the device landing zone. Intraprocedural assessment of the implantation result relied on echocardiography and hemodynamics. Five patients with severe aortic stenosis and at high risk for developing CIN were included. Device success was achieved in all patients and no major complications occurred. The median dose of injected contrast media was 8 ml (4-9). All but one patient had improved renal function after the intervention compared to baseline. Our study shows feasibility of performing TAVI with a single minimal contrast media injection, using a self-expandable valve. This technique has the potential to reduce the incidence of CIN. © 2015 Wiley Periodicals, Inc.

The Role of Student Loan Programs in Higher Education Policy in the United States

ERIC Educational Resources Information Center

Amatya, Sachi

2009-01-01

The increasing cost of higher education, coupled with the inability of federal and state governments to sustain parallel increases in levels of funding for student financial aid, has led to significant growth of student loans. This project analyzes the multidimensional student loans space in the US. This project also compares and contrasts some of…

Contrast Enhanced Spectral Mammography: A Review.

PubMed

Patel, Bhavika K; Lobbes, M B I; Lewin, John

2018-02-01

Contrast-enhanced spectral mammography (CESM) provides low-energy 2D mammographic images comparable to standard digital mammography and a post-contrast recombined image to assess tumor neovascularity similar to magnetic resonance imaging (MRI). The utilization of CESM in the United States is currently low but could increase rapidly given many potential indications for clinical use. This article discusses historical background and literature review of indications and diagnostic accuracy of CESM to date. CESM is a growing technique for breast cancer detection and diagnosis that has levels of sensitivity and specificity on par with contrast-enhanced breast MRI. Because of its similar performance and ease of implementation, CESM is being adopted for multiple indications previously reserved for MRI, such as problem-solving, disease extent in newly diagnosed patients, and evaluating the treatment response of neoadjuvant chemotherapy. Copyright © 2018 Elsevier Inc. All rights reserved.

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

DeVelice, R.L.; Hubbard, C.; Potkin, M.

This study documents ecological characteristics of areas in the Exxon Valdez oil spill area in southcentral Alaska with contrasting marbled murelet (Brachyramphus marmoratus) detection levels. A total of 73 vegetation and 41 physical site variables were evaluated. Marbled murrelet activity level (number of detections) and the frequency of occupied behavior (behaviors indicative of nesting) increased with increasing area of coniferous forest. There was a positive relationship between activity level and the number of mossy platforms in trees. Significant correlations with an index of incoming solar radiation are interpreted as indicating a preference of marbled murrelets for sites sheltered from highmore » winds and severe cold during the nesting period.« less

Protein Breakdown and Formation of Protease in Attached and Detached Cotyledons of Phaseolus vulgaris L.

PubMed

Yomo, H; Srinivasan, K

1973-12-01

In contrast to earlier reported results of similar experiments in peas, in which almost no increase in protease activity occurred in incubated detached cotyledons, we report here an increase in protease activity in both attached and detached bean cotyledons. Detached bean cotyledons showed continually increasing protease activity up to the 12th day, while that in attached cotyledons declined after 6 days. The free amino acid level in detached cotyledons reached a maximum at the 11th day; protease formation leveled off after 50% of the original seed protein was digested. These data suggest that high free amino acid levels may inhibit protease formation.The activity of partially purified protease in aqueous extracts was enhanced by 10 mm 2-mercaptoethanol or cysteine, indicating a sulfhydryl requirement for activation. Protease formation in detached cotyledons was inhibited 30% by 10 mug/ml cycloheximide and 50% by 100 mum abscisic acid. In contrast, alpha-amylase formation was inhibited 90% by 10 mug/ml cycloheximide and 95% by 20 mum abscisic acid. The cycloheximide data suggest that only a part of the protease, but all of the alpha-amylase, is synthesized de novo; the similar pattern of inhibition by abscisic acid emphasizes the concept that protease may exist in two forms.

Protein Breakdown and Formation of Protease in Attached and Detached Cotyledons of Phaseolus vulgaris L. 12

PubMed Central

Yomo, Harugoro; Srinivasan, Komala

1973-01-01

In contrast to earlier reported results of similar experiments in peas, in which almost no increase in protease activity occurred in incubated detached cotyledons, we report here an increase in protease activity in both attached and detached bean cotyledons. Detached bean cotyledons showed continually increasing protease activity up to the 12th day, while that in attached cotyledons declined after 6 days. The free amino acid level in detached cotyledons reached a maximum at the 11th day; protease formation leveled off after 50% of the original seed protein was digested. These data suggest that high free amino acid levels may inhibit protease formation. The activity of partially purified protease in aqueous extracts was enhanced by 10 mm 2-mercaptoethanol or cysteine, indicating a sulfhydryl requirement for activation. Protease formation in detached cotyledons was inhibited 30% by 10 μg/ml cycloheximide and 50% by 100 μm abscisic acid. In contrast, α-amylase formation was inhibited 90% by 10 μg/ml cycloheximide and 95% by 20 μm abscisic acid. The cycloheximide data suggest that only a part of the protease, but all of the α-amylase, is synthesized de novo; the similar pattern of inhibition by abscisic acid emphasizes the concept that protease may exist in two forms. PMID:16658628

Glucocorticoid receptor polymorphism in obesity and glucose homeostasis.

PubMed

Majer-Łobodzińska, Agnieszka; Adamiec-Mroczek, Joanna

2017-01-01

Glucocorticoid receptor (GR) activity plays a significant role in the etiology of obesity and is essential for glucose homeostasis, the development of hyperinsulinaemia and subsequent increased fat deposition. Several polymorphisms in the GR gene have been described, and at least three of them seem to be associated with altered glucocorticoid sensitivity and changes in glucose homeostasis, and other metabolic parameters. The N363S polymorphism has been associated with increased sensitivity to glucocorticoides, increased insulin response to dexamethasone and increased plasma glucose level. BclI polymorphism is associated with increased abdominal obesity, hyperinsulinaemia and increased insulin resistance. Another polymorphism, ER22/23EK, in contrast to the others, is associated with relative resistance to glucocoricides actions and more beneficial metabolic profile-lower insulin resistance level, decreased lower cardiovascular risk and subseuent prolongation of life time. More research is still needed to understand the mechanisms behind these associations at the molecular level.

A multiresolution processing method for contrast enhancement in portal imaging.

PubMed

Gonzalez-Lopez, Antonio

2018-06-18

Portal images have a unique feature among the imaging modalities used in radiotherapy: they provide direct visualization of the irradiated volumes. However, contrast and spatial resolution are strongly limited due to the high energy of the radiation sources. Because of this, imaging modalities using x-ray energy beams have gained importance in the verification of patient positioning, replacing portal imaging. The purpose of this work was to develop a method for the enhancement of local contrast in portal images. The method operates in the subbands of a wavelet decomposition of the image, re-scaling them in such a way that coefficients in the high and medium resolution subbands are amplified, an approach totally different of those operating on the image histogram, widely used nowadays. Portal images of an anthropomorphic phantom were acquired in an electronic portal imaging device (EPID). Then, different re-scaling strategies were investigated, studying the effects of the scaling parameters on the enhanced images. Also, the effect of using different types of transforms was studied. Finally, the implemented methods were combined with histogram equalization methods like the contrast limited adaptive histogram equalization (CLAHE), and these combinations were compared. Uniform amplification of the detail subbands shows the best results in contrast enhancement. On the other hand, linear re-escalation of the high resolution subbands increases the visibility of fine detail of the images, at the expense of an increase in noise levels. Also, since processing is applied only to detail subbands, not to the approximation, the mean gray level of the image is minimally modified and no further display adjustments are required. It is shown that re-escalation of the detail subbands of portal images can be used as an efficient method for the enhancement of both, the local contrast and the resolution of these images. © 2018 Institute of Physics and Engineering in Medicine.

Regulation of Bovine Leukemia Virus tax and pol mRNA Levels by Interleukin-2 and -10

PubMed Central

Pyeon, Dohun; Splitter, Gary A.

1999-01-01

Recently, particular cytokines have been identified to affect progression of a variety of diseases and retrovirus infections. Previously, we demonstrated that interleukin-2 (IL-2), IL-12, and gamma interferon increased in peripheral blood mononuclear cells (PBMCs) from animals with early disease and decreased in PBMCs from animals with late disease stages of bovine leukemia virus (BLV) infection. In contrast, IL-10 increased with disease progression. To examine the effects of these cytokines on BLV expression, BLV tax and pol mRNA and p24 protein were quantified by competitive PCR and immunoblotting, respectively. IL-10 inhibited BLV tax and pol mRNA levels in BLV-infected PBMCs; however, the inhibitory effect of IL-10 was prevented in PBMCs depleted of monocytes and/or macrophages (monocyte/macrophages). To determine whether these factors were secreted or monocyte/macrophage associated, monocyte/macrophage-depleted PBMCs were cultured with isolated monocyte/macrophages in transwells where contact between monocyte/macrophages and nonadherent PBMCs was blocked. BLV tax and pol mRNA levels increased in transwell cultures similar to cultures containing nonseparated cells, and IL-10 addition inhibited the increase of BLV tax and pol mRNA. These results suggest that monocyte/macrophages secrete soluble factor(s) that increases BLV mRNA levels and that secretion of these soluble factor(s) could be inhibited by IL-10. In contrast, IL-2 increased BLV tax and pol mRNA and p24 protein production. Thus, IL-10 production by BLV-infected animals with late stage disease may serve to control BLV mRNA levels, while IL-2 may increase BLV mRNA in the early disease stage. To determine a correlation between cell proliferation and BLV expression, the effect of IL-2 and IL-10 on PBMC proliferation was tested. As anticipated, IL-2 stimulated while IL-10 suppressed antigen-specific PBMC proliferation. The present study, combined with our previous findings, suggests that increased IL-10 production in late disease stages suppresses BLV mRNA levels, while IL-2-activated immune responses stimulate BLV expression by BLV-infected B cells. PMID:10482594

Spatial covert attention increases contrast sensitivity across the CSF: support for signal enhancement

NASA Technical Reports Server (NTRS)

Carrasco, M.; Penpeci-Talgar, C.; Eckstein, M.

2000-01-01

This study is the first to report the benefits of spatial covert attention on contrast sensitivity in a wide range of spatial frequencies when a target alone was presented in the absence of a local post-mask. We used a peripheral precue (a small circle indicating the target location) to explore the effects of covert spatial attention on contrast sensitivity as assessed by orientation discrimination (Experiments 1-4), detection (Experiments 2 and 3) and localization (Experiment 3) tasks. In all four experiments the target (a Gabor patch ranging in spatial frequency from 0.5 to 10 cpd) was presented alone in one of eight possible locations equidistant from fixation. Contrast sensitivity was consistently higher for peripherally- than for neutrally-cued trials, even though we eliminated variables (distracters, global masks, local masks, and location uncertainty) that are known to contribute to an external noise reduction explanation of attention. When observers were presented with vertical and horizontal Gabor patches an external noise reduction signal detection model accounted for the cueing benefit in a discrimination task (Experiment 1). However, such a model could not account for this benefit when location uncertainty was reduced, either by: (a) Increasing overall performance level (Experiment 2); (b) increasing stimulus contrast to enable fine discriminations of slightly tilted suprathreshold stimuli (Experiment 3); and (c) presenting a local post-mask (Experiment 4). Given that attentional benefits occurred under conditions that exclude all variables predicted by the external noise reduction model, these results support the signal enhancement model of attention.

Study on accumulated crystallization characteristics of amorphous Ge2Sb2Te5 induced by multi-pulsed laser irradiations with different fluences

NASA Astrophysics Data System (ADS)

Fan, T.; Liu, F. R.; Li, W. Q.; Guo, J. C.; Wang, Y. H.; Sun, N. X.; Liu, F.

2018-07-01

Accumulated crystallization characteristics of amorphous Ge2Sb2Te5 (a-GST) films induced by multi-pulsed laser irradiations with different fluences were investigated by x-ray diffraction (XRD), Raman spectroscopy and spectrophotometer. Solid-state transformation was performed at low fluence (LF, 30.5 mJ cm‑2), whereas melting-cooling transformation dominated at medium and high fluence (MF, 45.7 and HF, 61 mJ cm‑2). Solid-state transformation induced by subsequent LF pulses promoted the growth and coalescence of grains, linearly increasing the average grain size, accordingly causing blue-shifts of the Raman spectral peaks. For MF/HF pulse irradiated films, the relatively high laser fluence increased the melting depth and reduced the volume fraction of the crystalline state induced by individual pulses, thereby increasing the threshold of laser pulse numbers for XRD detectable crystallization. However, the remelting depth induced by subsequent MF/HF laser pulse progressively decreased. The remelting-recrystallization process refined grain sizes, which improved the red-shifts of Raman spectral peaks. Moreover, optical contrast increased dramatically compared to single laser irradiation and five-level storage could be realized for a linear increase of optical contrast. The present study is fundamental for realizing the potential of multi-level devices.

High dynamic range vision sensor for automotive applications

NASA Astrophysics Data System (ADS)

Grenet, Eric; Gyger, Steve; Heim, Pascal; Heitger, Friedrich; Kaess, Francois; Nussbaum, Pascal; Ruedi, Pierre-Francois

2005-02-01

A 128 x 128 pixels, 120 dB vision sensor extracting at the pixel level the contrast magnitude and direction of local image features is used to implement a lane tracking system. The contrast representation (relative change of illumination) delivered by the sensor is independent of the illumination level. Together with the high dynamic range of the sensor, it ensures a very stable image feature representation even with high spatial and temporal inhomogeneities of the illumination. Dispatching off chip image feature is done according to the contrast magnitude, prioritizing features with high contrast magnitude. This allows to reduce drastically the amount of data transmitted out of the chip, hence the processing power required for subsequent processing stages. To compensate for the low fill factor (9%) of the sensor, micro-lenses have been deposited which increase the sensitivity by a factor of 5, corresponding to an equivalent of 2000 ASA. An algorithm exploiting the contrast representation output by the vision sensor has been developed to estimate the position of a vehicle relative to the road markings. The algorithm first detects the road markings based on the contrast direction map. Then, it performs quadratic fits on selected kernel of 3 by 3 pixels to achieve sub-pixel accuracy on the estimation of the lane marking positions. The resulting precision on the estimation of the vehicle lateral position is 1 cm. The algorithm performs efficiently under a wide variety of environmental conditions, including night and rainy conditions.

Increased levels of IAA are required for system 2 ethylene synthesis causing fruit softening in peach (Prunus persica L. Batsch)

PubMed Central

Tatsuki, Miho

2013-01-01

The fruit of melting-flesh peach (Prunus persica L. Batsch) cultivars produce high levels of ethylene caused by high expression of PpACS1 (an isogene of 1-aminocyclopropane-1-carboxylic acid synthase), resulting in rapid fruit softening at the late-ripening stage. In contrast, the fruit of stony hard peach cultivars do not soften and produce little ethylene due to low expression of PpACS1. To elucidate the mechanism for suppressing PpACS1 expression in stony hard peaches, a microarray analysis was performed. Several genes that displayed similar expression patterns as PpACS1 were identified and shown to be indole-3-acetic acid (IAA)-inducible genes (Aux/IAA, SAUR). That is, expression of IAA-inducible genes increased at the late-ripening stage in melting flesh peaches; however, these transcripts were low in mature fruit of stony hard peaches. The IAA concentration increased suddenly just before harvest time in melting flesh peaches exactly coinciding with system 2 ethylene production. In contrast, the IAA concentration did not increase in stony hard peaches. Application of 1-naphthalene acetic acid, a synthetic auxin, to stony hard peaches induced a high level of PpACS1 expression, a large amount of ethylene production and softening. Application of an anti-auxin, α-(phenylethyl-2-one)-IAA, to melting flesh peaches reduced levels of PpACS1 expression and ethylene production. These observations indicate that suppression of PpACS1 expression at the late-ripening stage of stony hard peach may result from a low level of IAA and that a high concentration of IAA is required to generate a large amount of system 2 ethylene in peaches. PMID:23364941

Characterization of the Fate and Biotransformation of Fluorochemicals in AFFF-Contaminated Groundwater at Fire/Crash Testing Military Sites

DTIC Science & Technology

2017-04-10

L that remain above health advisory 56 levels of 1 µg/L 11. These areas also may serve as reservoirs for fluorinated compounds because 57 partially...in direct contrast to anionic pesticide sorption experiments, which found an increase in Kd with increasing AEC.37,79 The sorption of the...are less frequently studied, but zwitterionic pesticide sorption experiments found either an increase80 or no change81 in sorption with increasing

Gene expression of regulatory enzymes of glycolysis/gluconeogenesis in regenerating rat liver.

PubMed Central

Rosa, J L; Bartrons, R; Tauler, A

1992-01-01

Levels of mRNA for glucokinase, L-pyruvate kinase, fructose-1,6-bisphosphatase and phosphoenolpyruvate carboxykinase were analysed during liver regeneration. Levels of mRNA for glycolytic enzymes (glucokinase and L-pyruvate kinase) decreased rapidly after partial hepatectomy. Glucokinase mRNA increased at 16-24 h, returning to normal values after this time. L-pyruvate kinase mRNA recovered control levels at 168 h. In contrast, phosphoenolpyruvate carboxykinase mRNA increased rapidly after liver resection and remained high during the regenerative process. However, the levels of fructose-1,6-bisphosphatase mRNA were not modified significantly. These results correlate with the reported increased rate of gluconeogenesis and changes in enzyme levels after partial hepatectomy. The effect of stress on the mRNA levels was also studied. All enzymes showed variations in their mRNA levels after the surgical stress. In general, the differences were more pronounced in regenerating liver than in sham-operated animals, being practically normalized at 24 h. Images Fig. 2. Fig. 3. PMID:1329724

Comparing the Effectiveness of Traditional and Active Learning Methods in Business Statistics: Convergence to the Mean

ERIC Educational Resources Information Center

Weltman, David; Whiteside, Mary

2010-01-01

This research shows that active learning is not universally effective and, in fact, may inhibit learning for certain types of students. The results of this study show that as increased levels of active learning are utilized, student test scores decrease for those with a high grade point average. In contrast, test scores increase as active learning…

Estimated demand for lumber and plywood in Hawaii by the year 2000

Treesearch

George D. Frazier

1965-01-01

By the year 2000, total lumber consumption in Hawaii is expected to be between 78 and 128 million board feet. Hardwood lumber consumption is expected to exceed 16 million board feet — an increase of nearly 2½ times the present level of use. In contrast, softwood lumber use is expected to remain at about the present level of 79 million board feet. Plywood...

Evaluation of oxidative status in patients with brucellosis.

PubMed

Serefhanoglu, Kivanc; Taskin, Abdullah; Turan, Hale; Timurkaynak, Funda Ergin; Arslan, Hande; Erel, Ozcan

2009-08-01

Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. We aimed to determine total antioxidant capacity (TAC), total peroxide, malondialdehyde and catalase levels in plasma samples, and calculation of oxidative stress index (OSI) in patients with brucellosis to evaluate their oxidative status using a novel automated method. Sixty-nine patients with brucellosis and 69 healthy control subjects were included in the present study. Plasma levels of total peroxide and malondialdehyde were significantly increased in patients as compared with healthy controls (p<0.001 and p<0.001, respectively). In contrast, TAC level was significantly lower in patients as compared with controls (p<0.001). There was no statistically significant difference between the catalase results of the two groups (p>0.05). OSI level was significantly increased in patients as compared with healthy controls (p<0.001). In conclusion, oxidants were increased and antioxidants were decreased in patients with brucellosis. Oxidative stress was increased in patients with brucellosis.

Evaluation of Personal Cooling Systems in Conjunction with Explosive Ordnance Disposal Suits

DTIC Science & Technology

1992-06-01

of thermal comfort and perceived exertion. The results indicated that wearing the EOD suit produces significant increases in thermal physiological...indicated reduced perceived exertion levels and improved thermal comfort when wearing the liquid-cooling garment with a EOD suit. In contrast, the ribbed

The Effect of Community Uninsurance Rates on Access to Health Care

PubMed Central

Sabik, Lindsay M

2012-01-01

Objective To investigate the effect of local uninsurance rates on access to health care for the uninsured and insured and improve on recent studies by controlling for time-invariant differences across markets. Data Sources Individual-level data from the 1996 and 2003 Community Tracking Study, and market-level data from other sources, including the Area Resource File and the Bureau of Primary Healthcare. Study Design Market-level fixed effects models estimate the effect of changes in uninsurance rates within markets on access to care, measured by whether individuals report forgoing necessary care. Instrumental variables models are also estimated. Principal Findings Increases in the rate of uninsurance are associated with poorer access to necessary care among the uninsured. In contrast with recent evidence, increases in uninsurance had no effect on access to care among the insured. Instrumental variables results are similar, although not statistically significant. Conclusions Changes in rates of insurance coverage are likely to affect access to care for both previously and continuously uninsured. In contrast with earlier studies, there is no evidence of spillover effects on the insured, suggesting that such policy changes may have little effect on access for those who are already insured. PMID:22172046

Effect of experimental hyperthyroidism on protein turnover in skeletal and cardiac muscle.

PubMed

Carter, W J; Van Der Weijden Benjamin, W S; Faas, F H

1980-10-01

Since experimental hyperthyroidism reduces skeletal muscle mass while simultaneously increasing cardiac muscle mass, the effect of hyperthyroidism on muscle protein degradation was compared in skeletal and cardiac muscle. Pulse-labeling studies using (3H) leucine and (14C) carboxyl labeled aspartate and glutamate were carried out. Hyperthyroidism caused a 25%-29% increase in protein breakdown in both sarcoplasmic and myofibrillar fractions of skeletal muscle. Increased muscle protein degradation may be a major factor in the development of skeletal muscle wasting and weakness in hyperthyroidism. In contrast, protein breakdown appeared to be reduced 22% in the sarcoplasmic fraction of hyperthyroid heart muscle and was unchanged in the myofibrillar fraction. Possible reasons for the contrasting effects of hyperthyroidism on skeletal and cardiac muscle include increased sensitivity of the hyperthyroid heart to catecholamines, increased cardiac work caused by the hemodynamic effects of hyperthyroidism, and a different direct effect of thyroid hormone at the nuclear level in cardiac as opposed to skeletal muscle.

Effects of developer exhaustion on Kodak EKTASPEED Plus, Ektaspeed, and Ultra-speed dental films.

PubMed

Thunthy, K H; Weinberg, R

1995-01-01

In 1994, Eastman Kodak Co. (Rochester, N.Y.) replaced its Ektaspeed film with the EKTASPEED Plus film. The manufacturer claims that one of the advantages of the new film is that it is not strongly affected by exhausted (depleted plus aged) processing solutions. The objective of the experiment was to test this claim. In exhausted solutions, EKTASPEED Plus film lost its speed more rapidly than Ultra-speed film but less rapidly than Ektaspeed film; that is, Ultra-speed film had the most stable speed. EKTASPEED Plus film lost contrast for 2 weeks before stabilizing, whereas Ultra-speed and Ektaspeed films continued to lose contrast for 3 weeks. Overall, EKTASPEED Plus film held its contrast over the other two films. EKTASPEED Plus film stopped increasing its film latitude after 2 weeks, whereas Ultra-speed and Ektaspeed films continued to increase film latitudes. In conclusion, for the three films studied, EKTASPEED Plus maintained the most constant levels of contrast and latitude in progressively exhausted solutions. All three films lost speed in exhausted solutions; EKTASPEED Plus film was the fastest but Ultra-speed film had the most stable speed.

Equilibrium climate response of the East Asian summer monsoon to forcing of anthropogenic aerosol species

NASA Astrophysics Data System (ADS)

Wang, Zhili; Wang, Qiuyan; Zhang, Hua

2017-12-01

We used an online aerosol-climate model to study the equilibrium climate response of the East Asian summer monsoon (EASM) to increases in anthropogenic emissions of sulfate, organic carbon, and black carbon aerosols from 1850 to 2000. Our results show that each of these aerosol species has a different effect on the EASM as a result of changes in the local sea-land thermal contrast and atmospheric circulation. The increased emission of sulfate aerosol leads to a decrease in the thermal contrast between the land and ocean, a southward shift of the East Asian subtropical jet, and significant northerly wind anomalies at 850 hPa over eastern China and the ambient oceans, markedly dampening the EASM. An increase in organic carbon aerosol results in pronounced surface cooling and the formation of an anomalous anticyclone over the oceans north of 30°N. These effects cause a slight increase in the sea-land thermal contrast and southerly flow anomalies to the west of the anticyclonic center, strengthening the northern EASM. An increase in organic carbon emission decreases the sea-land thermal contrast over southern China, which weakens the southern EASM. The response of the summer 850-hPa winds and rainfall over the East Asian monsoon region to an increase in black carbon emission is generally consistent with the response to an increase in organic carbon. The increase in black carbon emission leads to a strengthening of the northern EASM north of 35°N and a slight weakening of the southern EASM south of 35°N. The simulated response of the EASM to the increase in black carbon emission is unchanged when the emission of black carbon is scaled up by five times its year 2000 levels, although the intensities of the response is enhanced. The increase in sulfate emission primarily weakens the EASM, whereas the increases in black carbon and organic carbon emissions mitigate weakening of the northern EASM.

Four kingdoms on glacier ice: convergent energetic processes boost energy levels as temperatures fall.

PubMed Central

Napolitano, Michael J; Shain, Daniel H

2004-01-01

A diverse group of glacially obligate organisms coexist on temperate glaciers between Washington State and Alaska. A fundamental challenge for these and other cold-adapted species is the necessity to maintain an energy flux capable of sustaining life at low physiological temperatures. We show here that ice-adapted psychrophiles from four kingdoms (Animalia, Eubacteria, Fungi, Protista) respond to temperature fluctuations in a similar manner; namely, ATP levels and the total adenylate pool increase as temperatures fall (within their viable temperature limits, respectively), yet growth rate increases with temperature. By contrast, mesophilic representatives of each kingdom respond in an opposite manner (i.e. adenylates increase with temperature). These observations suggest that elevated adenylate levels in psychrophiles may offset inherent reductions in molecular diffusion at low physiological temperatures. PMID:15503992

Motion-Induced Blindness and Troxler Fading: Common and Different Mechanisms

PubMed Central

Bonneh, Yoram S.; Donner, Tobias H.; Cooperman, Alexander; Heeger, David J.; Sagi, Dov

2014-01-01

Extended stabilization of gaze leads to disappearance of dim visual targets presented peripherally. This phenomenon, known as Troxler fading, is thought to result from neuronal adaptation. Intense targets also disappear intermittently when surrounded by a moving pattern (the “mask”), a phenomenon known as motion-induced blindness (MIB). The similar phenomenology and dynamics of these disappearances may suggest that also MIB is, likewise, solely due to adaptation, which may be amplified by the presence of the mask. Here we directly compared the dependence of both phenomena on target contrast. Observers reported the disappearance and reappearance of a target of varying intensity (contrast levels: 8%–80%). MIB was induced by adding a mask that moved at one of various different speeds. The results revealed a lawful effect of contrast in both MIB and Troxler fading, but with opposite trends. Increasing target contrast increased (doubled) the rate of disappearance events for MIB, but decreased the disappearance rate to half in Troxler fading. The target mean invisible period decreased equally strongly with target contrast in MIB and in Troxler fading. The results suggest that both MIB and Troxler are equally affected by contrast adaptation, but that the rate of MIB is governed by an additional mechanism, possibly involving antagonistic processes between neuronal populations processing target and mask. Our results link MIB to other bi-stable visual phenomena that involve neuronal competition (such as binocular rivalry), which exhibit an analogous dependency on the strength of the competing stimulus components. PMID:24658600

Cerebral Hemodynamics in Patients with Hemolytic Uremic Syndrome Assessed by Susceptibility Weighted Imaging and Four-Dimensional Non-Contrast MR Angiography.

PubMed

Löbel, Ulrike; Forkert, Nils Daniel; Schmitt, Peter; Dohrmann, Thorsten; Schroeder, Maria; Magnus, Tim; Kluge, Stefan; Weiler-Normann, Christina; Bi, Xiaoming; Fiehler, Jens; Sedlacik, Jan

2016-01-01

Conventional magnetic resonance imaging (MRI) of patients with hemolytic uremic syndrome (HUS) and neurological symptoms performed during an epidemic outbreak of Escherichia coli O104:H4 in Northern Europe has previously shown pathological changes in only approximately 50% of patients. In contrast, susceptibility-weighted imaging (SWI) revealed a loss of venous contrast in a large number of patients. We hypothesized that this observation may be due to an increase in cerebral blood flow (CBF) and aimed to identify a plausible cause. Baseline 1.5T MRI scans of 36 patients (female, 26; male, 10; mean age, 38.2±19.3 years) were evaluated. Venous contrast was rated on standard SWI minimum intensity projections. A prototype four-dimensional (time resolved) magnetic resonance angiography (4D MRA) assessed cerebral hemodynamics by global time-to-peak (TTP), as a surrogate marker for CBF. Clinical parameters studied were hemoglobin, hematocrit, creatinine, urea levels, blood pressure, heart rate, and end-tidal CO2. SWI venous contrast was abnormally low in 33 of 36 patients. TTP ranged from 3.7 to 10.2 frames (mean, 7.9 ± 1.4). Hemoglobin at the time of MRI (n = 35) was decreased in all patients (range, 5.0 to 12.6 g/dL; mean, 8.2 ± 1.4); hematocrit (n = 33) was abnormally low in all but a single patient (range, 14.3 to 37.2%; mean, 23.7 ± 4.2). Creatinine was abnormally high in 30 of 36 patients (83%) (range, 0.8 to 9.7; mean, 3.7 ± 2.2). SWI venous contrast correlated significantly with hemoglobin (r = 0.52, P = 0.0015), hematocrit (r = 0.65, P < 0.001), and TTP (r = 0.35, P = 0.036). No correlation of SWI with blood pressure, heart rate, end-tidal CO2, creatinine, and urea level was observed. Findings suggest that the loss of venous contrast is related to an increase in CBF secondary to severe anemia related to HUS. SWI contrast of patients with pathological conventional MRI findings was significantly lower compared to patients with normal MRI (mean SWI score, 1.41 and 2.05, respectively; P = 0.04). In patients with abnormal conventional MRI, mean TTP (7.45), mean hemoglobin (7.65), and mean hematocrit (22.0) were lower compared to patients with normal conventional MRI scans (mean TTP = 8.28, mean hemoglobin = 8.63, mean hematocrit = 25.23). In contrast to conventional MRI, almost all patients showed pathological changes in cerebral hemodynamics assessed by SWI and 4D MRA. Loss of venous contrast on SWI is most likely the result of an increase in CBF and may be related to the acute onset of anemia. Future studies will be needed to assess a possible therapeutic effect of blood transfusions in patients with HUS and neurological symptoms.

High-dose MVCT image guidance for stereotactic body radiation therapy

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

Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D.

Purpose: Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance. Methods: Two nonstandard, high-dose imaging modes were created on a tomotherapy machinemore » by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison. Results: MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp/mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable. Conclusions: High-dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3-5 fractions.« less

High-dose MVCT image guidance for stereotactic body radiation therapy.

PubMed

Westerly, David C; Schefter, Tracey E; Kavanagh, Brian D; Chao, Edward; Lucas, Dan; Flynn, Ryan T; Miften, Moyed

2012-08-01

Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance. Two nonstandard, high-dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison. MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp∕mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable. High-dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3-5 fractions.

Factoring the brain signatures of anesthesia concentration and level of arousal across individuals.

PubMed

Barttfeld, Pablo; Bekinschtein, Tristan A; Salles, Alejo; Stamatakis, Emmanuel A; Adapa, Ram; Menon, David K; Sigman, Mariano

2015-01-01

Combining resting-state functional magnetic resonance imaging (fMRI) connectivity and behavioral analysis during sedation, we factored out general effects of the anesthetic drug propofol and a specific index of conscious report, participants' level of responsiveness. The factorial analysis shows that increasing concentration of propofol in blood specifically decreases the connectivity strength of fronto-parietal cortical loops. In contrast, loss of responsiveness is indexed by a functional disconnection between the thalamus and the frontal cortex, balanced by an increase in connectivity strength of the thalamus to the occipital and temporal regions of the cortex.

Factoring the brain signatures of anesthesia concentration and level of arousal across individuals

PubMed Central

Barttfeld, Pablo; Bekinschtein, Tristan A.; Salles, Alejo; Stamatakis, Emmanuel A.; Adapa, Ram; Menon, David K.; Sigman, Mariano

2015-01-01

Combining resting-state functional magnetic resonance imaging (fMRI) connectivity and behavioral analysis during sedation, we factored out general effects of the anesthetic drug propofol and a specific index of conscious report, participants’ level of responsiveness. The factorial analysis shows that increasing concentration of propofol in blood specifically decreases the connectivity strength of fronto-parietal cortical loops. In contrast, loss of responsiveness is indexed by a functional disconnection between the thalamus and the frontal cortex, balanced by an increase in connectivity strength of the thalamus to the occipital and temporal regions of the cortex. PMID:26509121

Treatment options for hypertriglyceridemia: from risk reduction to pancreatitis

PubMed Central

Berglund, Lars; Brunzell, John D.; Goldberg, Anne C.; Goldberg, Ira J.; Stalenhoef, Anton

2013-01-01

While there has been considerable focus on the role and treatment of LDL cholesterol levels, a definitive role of triglycerides in the management of cardiovascular disease has been uncertain. Notably, with increasing triglyceride levels, there is a parallel increase in cholesterol levels carried by triglyceride-rich lipoproteins, which has prompted interest in the use of non-HDL cholesterol levels as a tool guiding interventions. Recent studies have provided evidence for an independent role of triglyceride levels as a cardiovascular risk factor, and recently, an Endocrine Society guideline was published for treatment of hypertriglyceridemia. In contrast to the relative uncertainty regarding triglycerides and cardiovascular disease, a role of very high triglyceride levels as a risk factor for pancreatitis has been well known. The present paper summarizes the underlying evidence for a risk role for triglyceride levels in cardiovascular disease and pancreatitis, current treatment recommendations and areas of future research. PMID:24840268

Ecological correlates of depression and self-esteem in rural youth.

PubMed

Smokowski, Paul R; Evans, Caroline B R; Cotter, Katie L; Guo, Shenyang

2014-10-01

The current study examines individual-, social-, and school-level characteristics influencing symptoms of depression and self-esteem among a large sample (N = 4,321) of U.S. youth living in two rural counties in the South. Survey data for this sample of middle-school students (Grade 6 to Grade 8) were part of the Rural Adaptation Project. Data were analyzed using ordered logistic regression. Results show that being female, having a low income, and having negative relationships with parents and peers are risk factors that increase the probability of reporting high levels of depressive symptoms and low levels of self-esteem. In contrast, supportive relationships with parents and peers, high religious orientation, ethnic identity, and school satisfaction increased the probability of reporting low levels of depressive symptoms and high levels of self-esteem. There were few school-level characteristics associated with levels of depressive symptoms and self-esteem. Implications are discussed.

Comparison of effects of isotonic sodium chloride with diltiazem in prevention of contrast-induced nephropathy.

PubMed

Beyazal, Hatice; Caliskan, Zuhal; Utaç, Cengiz

2014-04-01

Contrast-induced nephropathy (CIN) significantly increases the morbidity and mortality of patients. The aim of this study is to investigate and compare the protective effects of isotonic sodium chloride with sodium bicarbonate infusion and isotonic sodium chloride infusion with diltiazem, a calcium channel blocker, in preventing CIN. Our study included patients who were administered 30-60 mL of iodinated contrast agent for percutaneous coronary angiography (PCAG), all with creatinine values between 1.1 and 3.1 mg/dL. Patients were divided into three groups and each group had 20 patients. The first group of patients was administered isotonic sodium chloride; the second group was administered a solution that of 5% dextrose and sodium bicarbonate, while the third group was administered isotonic sodium chloride before and after the contrast injection. The third group received an additional injection of diltiazem the day before and first 2 days after the contrast injection. All of the patients' plasma blood urea nitrogen (BUN) and creatinine levels were measured on the second and seventh day after the administration of intravenous contrast material. The basal creatinine levels were similar for all three groups (p > 0.05). Among a total of 60 patients included in the study, 16 patients developed acute renal failure (ARF) on the second day after contrast material was injected (26.6%). The number of patients who developed ARF on the second day after the injection in the first group was five (25%), in the second group was six (30%) and the third group was five (25%) (p > 0.05). There was no significant difference between isotonic sodium chloride, sodium bicarbonate and isotonic sodium chloride with diltiazem application in prevention of CIN.

Effect of radiographic contrast media on markers of complement activation and apoptosis in patients with chronic coronary artery disease undergoing coronary angiography.

PubMed

Deftereos, Spyridon; Giannopoulos, Georgios; Kossyvakis, Charalampos; Raisakis, Konstantinos; Kaoukis, Andreas; Driva, Metaxia; Ntzouvara, Olga; Panagopoulou, Vasiliki; Rentoukas, Ilias; Nikas, Dimitrios J; Pyrgakis, Vlasios; Alpert, Martin A

2009-09-01

The effects of radiographic contrast media on markers of complement activation and apoptosis in patients with chronic coronary artery disease (CAD) are unknown. The purpose of this study was to assess the comparative effects of ionic high-osmolar and non-ionic iso-osmolar radiographic contrast media on plasma markers of complement activation and apoptosis in patients with chronic CAD undergoing coronary angiography. Forty-four patients undergoing coronary angiography for chronic CAD were randomly assigned to receive the ionic high-osmolar radiographic contrast agent diatrizoate (Group A), or the non-ionic iso-osmolar contrast agent iodixanol (Group B) during angiography. Complement component 5 (C5a) and apoptotic markers sFas and sFasL were measured just prior to angiography and 1 hour after completion of angiography. Comparison of mean pre- and post-angiography plasma marker levels showed significantly greater increases in plasma levels in Group A than in Group B of C5a (29.30 +/- 5.45 ng/ml for Group A and 0.47 +/- 0.70 ng/ml for Group B (p < 0.00001), sFas (2.36 +/- 1.63 ng/ml for Group A and 0.23 +/- 0.90 ng/ml for Group B (p < 0.00001) and sFasL (14.00 +/- 5.41 pg/ml for Group A and 0.01 +/- 1.00 pg/ml for Group B (p < 0.00001). The results suggest that in patients with chronic CAD, the use of ionic high-osmolar radiographic contrast media during coronary angiography is associated with a more robust inflammatory and apoptotic milieu than that associated with the use of non-ionic iso-osmolar radiographic contrast media.

Preserving older adults' routine outdoor activities in contrasting neighborhood environments through a physical activity intervention

USDA-ARS?s Scientific Manuscript database

While neighborhood design can potentially influence routine outdoor physical activities (PA), little is known concerning its effects on such activities among older adults attempting to increase their PA levels. We evaluated the effects of living in neighborhoods differing in compactness on changes i...

SU-E-I-33: Initial Evaluation of Model-Based Iterative CT Reconstruction Using Standard Image Quality Phantoms

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

Gingold, E; Dave, J

2014-06-01

Purpose: The purpose of this study was to compare a new model-based iterative reconstruction with existing reconstruction methods (filtered backprojection and basic iterative reconstruction) using quantitative analysis of standard image quality phantom images. Methods: An ACR accreditation phantom (Gammex 464) and a CATPHAN600 phantom were scanned using 3 routine clinical acquisition protocols (adult axial brain, adult abdomen, and pediatric abdomen) on a Philips iCT system. Each scan was acquired using default conditions and 75%, 50% and 25% dose levels. Images were reconstructed using standard filtered backprojection (FBP), conventional iterative reconstruction (iDose4) and a prototype model-based iterative reconstruction (IMR). Phantom measurementsmore » included CT number accuracy, contrast to noise ratio (CNR), modulation transfer function (MTF), low contrast detectability (LCD), and noise power spectrum (NPS). Results: The choice of reconstruction method had no effect on CT number accuracy, or MTF (p<0.01). The CNR of a 6 HU contrast target was improved by 1–67% with iDose4 relative to FBP, while IMR improved CNR by 145–367% across all protocols and dose levels. Within each scan protocol, the CNR improvement from IMR vs FBP showed a general trend of greater improvement at lower dose levels. NPS magnitude was greatest for FBP and lowest for IMR. The NPS of the IMR reconstruction showed a pronounced decrease with increasing spatial frequency, consistent with the unusual noise texture seen in IMR images. Conclusion: Iterative Model Reconstruction reduces noise and improves contrast-to-noise ratio without sacrificing spatial resolution in CT phantom images. This offers the possibility of radiation dose reduction and improved low contrast detectability compared with filtered backprojection or conventional iterative reconstruction.« less

The Nature of The Propagation of Sea Breeze Fronts in Central California

DTIC Science & Technology

1990-09-01

propagation vector % ith stations in the southern portion of Monterey Bay shows that the front is curved on the mesoscale. 20 Distribution Availabilit of...solar radiation warms the land more than the adjacent water . The resulting temperature contrast produces a slight variation in pressure. The isobaric...surfaces bend upward over the land, producing an upper-level high. The upper-level air flows seaward increasing the surface pressure over the water . The

Differential effects of two MRI contrast agents on the integrity and distribution of rAAV2 and rAAV5 in the rat striatum

PubMed Central

Osting, Sue; Bennett, Antonette; Power, Shelby; Wackett, Jordan; Hurley, Samuel A; Alexander, Andrew L; Agbandje-Mckena, Mavis; Burger, Corinna

2014-01-01

Intraoperative magnetic resonance imaging (MRI) has been proposed as a method to optimize intracerebral targeting and for tracking infusate distribution in gene therapy trials for nervous system disorders. We thus investigated possible effects of two MRI contrast agents, gadoteridol (Gd) and galbumin (Gab), on the distribution and levels of transgene expression in the rat striatum and their effect on integrity and stability of recombinant adeno-associated virus (rAAV) particles. MRI studies showed that contrast agent distribution did not predict rAAV distribution. However, green fluorescent protein (GFP) immunoreactivity revealed an increase in distribution of rAAV5-GFP, but not rAAV2-GFP, in the presence of Gd when compared with viral vector injected alone. In contrast, Gab increased the distribution of rAAV2-GFP not rAAV5-GFP. These observations pointed to a direct effect of infused contrast agent on the rAAV particles. Negative-stain electron microscopy (EM), DNAase treatment, and differential scanning calorimetry (DSC) were used to monitor rAAV2 and rAAV5 particle integrity and stability following contrast agent incubation. EMs of rAAV2-GFP and rAAV5-GFP particles pretreated with Gd appear morphologically similar to the untreated sample; however, Gab treatment resulted in surface morphology changes and aggregation. A compromise of particle integrity was suggested by sensitivity of the packaged genome to DNAase treatment following Gab incubation but not Gd for both vectors. However, neither agent significantly affected particle stability when analyzed by DSC. An increase in Tm was observed for AAV2 in lactated Ringer’s buffer. These results thus highlight potential interactions between MRI contrast agents and AAV that might affect vector distribution and stability, as well as the stabilizing effect of lactated Ringer’s solution on AAV2. PMID:26015943

Oxygen-induced frequency shifts in hyperoxia: a significant component of BOLD signal.

PubMed

Song, Youngkyu; Cho, Gyunggoo; Chun, Song-I; Baek, Jin Hee; Cho, HyungJoon; Kim, Young Ro; Park, Sung Bin; Kim, Jeong Kon

2014-07-01

In comparison to the well-documented significance of intravascular deoxyhemoglobin (deoxyHgb), the effects of dissolved oxygen on the blood-oxygen-level-dependent (BOLD) signal have not been widely reported. Based on the fact that the prolonged inspiration of high oxygen fraction gas can result in up to a sixfold increase of the baseline tissue oxygenation, the current study focused on the influence of dissolved oxygen on the BOLD signal during hyperoxia. As results, our in vitro study revealed that the r1 and r2 (relaxivities) of the oxygen-treated serum were 0.22 mM(-1) · s(-1) and 0.19 mM(-1) · s(-1) , respectively. In an in vivo experiment, hyperoxic respiration induced negative BOLD contrast (i.e. signal decrease) in 18-42% of measured brain regions, voxels with accompanying significant decreases in both the T(*)2 (-12.1% to -19.4%) and T1 (-5.8% to -3.3%) relaxation times. In contrast, the T(*)2 relaxation time significantly increased (11.2% to 14.0%) for the voxels displaying positive BOLD contrast (in 41-50% of the measured brain), which reflected a hyperoxygenation-induced reduction in tissue deoxyHgb concentration. These data imply that hyperoxia-driven BOLD signal changes are primarily determined by the counteracting effects of extravascular oxygen and intravascular deoxyHgb. Oxygen-induced magnetic susceptibility was further demonstrated by the study of 1 min hypoxia, which induced BOLD signal changes opposite to those under hyperoxia. Vasoconstriction was more common in voxels with negative BOLD contrast than in voxels with positive contrast (% change of blood volume, -9.8% to -12.8% versus 2.0% to 2.2%), which further suggests that negative BOLD contrast is mainly evoked by an increase in extravascular oxygen concentration. Conclusively, frequency shifts, which are induced by the accumulation of oxygen molecules and associated magnetic field inhomogeneity, are a significant source of the negative BOLD contrast during hyperoxia. Copyright © 2014 John Wiley & Sons, Ltd.

F-Box Protein FBX92 Affects Leaf Size in Arabidopsis thaliana

PubMed Central

Baute, Joke; Polyn, Stefanie; De Block, Jolien; Blomme, Jonas; Van Lijsebettens, Mieke

2017-01-01

F-box proteins are part of one of the largest families of regulatory proteins that play important roles in protein degradation. In plants, F-box proteins are functionally very diverse, and only a small subset has been characterized in detail. Here, we identified a novel F-box protein FBX92 as a repressor of leaf growth in Arabidopsis. Overexpression of AtFBX92 resulted in plants with smaller leaves than the wild type, whereas plants with reduced levels of AtFBX92 showed, in contrast, increased leaf growth by stimulating cell proliferation. Detailed cellular analysis suggested that AtFBX92 specifically affects the rate of cell division during early leaf development. This is supported by the increased expression levels of several cell cycle genes in plants with reduced AtFBX92 levels. Surprisingly, overexpression of the maize homologous gene ZmFBX92 in maize had no effect on plant growth, whereas ectopic expression in Arabidopsis increased leaf growth. Expression of a truncated form of AtFBX92 showed that the contrasting effects of ZmFBX92 and AtFBX92 gain of function in Arabidopsis are due to the absence of the F-box-associated domain in the ZmFBX92 gene. Our work reveals an additional player in the complex network that determines leaf size and lays the foundation for identifying putative substrates. PMID:28340173

Comparison of Oogenesis and Sex Steroid Profiles between Twice and Once Annually Spawning of Rainbow Trout Females (Oncorhynchus mykiss)

PubMed Central

Estay, Francisco; Colihueque, Nelson; Araneda, Cristian

2012-01-01

This study compares the gonadosomatic index (GSI), oocyte growth (OG), gonadal histology, and plasma level concentrations of sex hormones (estradiol-17β (E2) and vitellogenin (V)) of twice-spawning (T-SP) and once-spawning (O-SP) females of rainbow trout throughout the additional and the normal reproductive cycle, respectively. In T-SP, the GSI values rapidly increase from May to November, in contrast to O-SP, which showed low and constant GSI values (1.19 to 14.5 and 1.19 to 0.63, resp.). T-SP exhibited a marked increase of OG in the same period, reaching a maximum diameter of 4,900 ± 141.42 μm, in contrast to O-SP, which presented a slow OG. The gonadal histology of T-SP agreed with the general pattern of ovogenesis observed for O-SP (vitellogenesis, ovulation, and recrudescence); however, this process was nonsynchronous between the two breeder groups. Plasma steroid levels showed significant variation during oogenesis, which agreed with the GSI, OG, and gonadal histology patterns. The level of E2 increased to a maximum value of 26.2 ng/mL and 36.0 ng/mL in O-SP and T-SP, respectively, one or two months before the spawning event where vitellogenesis was fully active. The V concentrations followed a pattern similar to those of E2. PMID:23213308

[Diet in pathogenesis of acne vulgaris].

PubMed

Ozdarska, Katarzyna; Osucha, Karolina; Savitskyi, Stepan; Malejczyk, Jacek; Galus, Ryszard

2017-10-23

Acne vulgaris is one of the most common dermatologic condition especially among adolescents. Acne is related to excess sebum production by sebaceous glands, inflammation both within and adjacent to the comedones, hyperproliferation of Propionibacterium acnes. Some of investigations show association between acne and diet. Milk increases the level of IGF-1 leading to the synthesis of androgen-mediated increases sebum production. Chocolate predispose to hyperglycemia and insulinemia which aggravate of acne vulgaris. High levels of omega-6 fatty acids have been associated with increase of acne in contrast to omega-3 fatty acids, which decrease inflammation. Food have huge impact on development and severity of acne and may exert beneficial effect in the treatment of this disorder.

The Effects of Iodine Attenuation on Pulmonary Nodule Volumetry using Novel Dual-Layer Computed Tomography Reconstructions.

PubMed

den Harder, A M; Bangert, F; van Hamersvelt, R W; Leiner, T; Milles, Julien; Schilham, A M R; Willemink, M J; de Jong, P A

2017-12-01

To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions. A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel dual-layer spectral CT system. Conventional reconstructions as well as VNC and mono-energetic images at different keV levels were used for nodule volumetry. Twenty-four patients with a total of 63 nodules were included. Conventional reconstructions showed a median (interquartile range) volume and diameter of 174 (87 - 253) mm 3 and 6.9 (5.4 - 9.9) mm, respectively. VNC reconstructions resulted in a significant volume reduction of 5.5% (2.6 - 11.2%; p<0.001). Mono-energetic reconstructions showed a correlation between nodule attenuation and nodule volume (Spearman correlation 0.77, (0.49 - 0.94)). Lowering the keV resulted in increased volumes while higher keV levels resulted in decreased pulmonary nodule volumes compared to conventional CT. Novel dual-layer spectral CT offers the possibility to reconstruct VNC and mono-energetic images. Those reconstructions show that higher pulmonary nodule attenuation results in larger nodule volumes. This may explain the reported underestimation in nodule volume on non-contrast enhanced compared to contrast-enhanced acquisitions. • Pulmonary nodule volumes were measured on virtual non-contrast and mono-energetic reconstructions • Mono-energetic reconstructions showed that higher attenuation results in larger volumes • This may explain the reported nodule volume underestimation on non-contrast enhanced CT • Mostly metastatic pulmonary nodules were evaluated, results might differ for benign nodules.

Osteopontin plays a pivotal role in increasing severity of respiratory syncytial virus infection

PubMed Central

Sampayo-Escobar, Viviana; Green, Ryan; Cheung, Michael B.; Bedi, Raminder; Mohapatra, Subhra

2018-01-01

The molecular mechanisms underlying susceptibility to severe respiratory syncytial virus (RSV) infection remain poorly understood. Herein, we report on the role of osteopontin (OPN) in regulation of RSV infection in human epithelial cells and how interleukin-1 beta (IL-1β), a cytokine secreted soon after RSV infection, when persistently expressed can induce OPN expression leading to increased viral infection. We first compared OPN expression in two human epithelial cell lines: HEK-293 and HEp-2. In contrast to HEp-2, HEK-293 expresses low levels of pro-caspase-1 resulting in decreased IL-1β expression in response to RSV infection. We found a correlation between low IL-1β levels and a delay in induction of OPN expression in RSV-infected HEK-293 cells compared to HEp-2. This phenomenon could partially explain the high susceptibility of HEp-2 cells to RSV infection versus the moderate susceptibility of HEK-293 cells. Also, HEK-293 cells expressing low levels of pro-caspase-1 exhibit decreased IL-1β expression and delayed OPN expression in response to RSV infection. HEK-293 cells incubated with human rIL-1β showed a dose-dependent increase in OPN expression upon RSV infection. Also, incubation with rOPN increased RSV viral load. Moreover, HEp-2 cells or mice infected with a mucogenic RSV strain RSV-L19F showed elevated levels of OPN in contrast to mice infected with the laboratory RSV strain rA2. This correlated with elevated levels of OPN following infection with RSV-L19F compared to rA2. Together, these results demonstrate that increased OPN expression is regulated in part by IL-1β, and the interplay between IL-1β and OPN signaling may play a pivotal role in the spread of RSV infection. PMID:29677209

A CloudSat-CALIPSO View of Cloud and Precipitation Properties Across Cold Fronts over the Global Oceans

NASA Technical Reports Server (NTRS)

Naud, Catherine M.; Posselt, Derek J.; van den Heever, Susan C.

2015-01-01

The distribution of cloud and precipitation properties across oceanic extratropical cyclone cold fronts is examined using four years of combined CloudSat radar and CALIPSO lidar retrievals. The global annual mean cloud and precipitation distributions show that low-level clouds are ubiquitous in the post frontal zone while higher-level cloud frequency and precipitation peak in the warm sector along the surface front. Increases in temperature and moisture within the cold front region are associated with larger high-level but lower mid-/low level cloud frequencies and precipitation decreases in the cold sector. This behavior seems to be related to a shift from stratiform to convective clouds and precipitation. Stronger ascent in the warm conveyor belt tends to enhance cloudiness and precipitation across the cold front. A strong temperature contrast between the warm and cold sectors also encourages greater post-cold-frontal cloud occurrence. While the seasonal contrasts in environmental temperature, moisture, and ascent strength are enough to explain most of the variations in cloud and precipitation across cold fronts in both hemispheres, they do not fully explain the differences between Northern and Southern Hemisphere cold fronts. These differences are better explained when the impact of the contrast in temperature across the cold front is also considered. In addition, these large-scale parameters do not explain the relatively large frequency in springtime post frontal precipitation.

Theoretical study of metal noble-gas positive ions

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.

1989-01-01

Theoretical calculations have been performed to determine the spectroscopic constant for the ground and selected low-lying electronic states of the transition-metal noble-gas ions Var(+), FeAr(+), CoAr(+), CuHe(+), CuAr(+), and CuKr(+). Analogous calculations have been performed for the ground states of the alkali noble-gas ions LiAr(+), LiKr(+), NaAr(+), and KAr(+) and the alkaline-earth noble-gas ion MgAr(+) to contrast the difference in binding energies between the simple and transition-metal noble-gas ions. The binding energies increase with increasing polarizability of the noble-gas ions, as expected for a charge-induced dipole bonding mechanism. It is found that the spectroscopic constants of the X 1Sigma(+) states of the alkali noble-gas ions are well described at the self-consistent field level. In contrast, the binding energies of the transition-metal noble-gas ions are substantially increased by electron correlation.

Fires in Non-drought Conditions in Indonesia: the Role of Increasing Temperatures

NASA Astrophysics Data System (ADS)

Fernandes, K.; Verchot, L. V.; Baethgen, W.; Gutierrez-Velez, V.; Pinedo-Vasquez, M.; Martius, C.

2017-12-01

In Indonesia, drought driven fires occur typically during the warm phase of the El Niño Southern Oscillation (ENSO), such as those of 1997 and 2015 that resulted in months-long hazardous atmospheric pollution levels in Equatorial Asia and record greenhouse gas emissions. Nonetheless, anomalously active fire seasons have also been observed in non-drought years. In this work, we investigated whether fires are impacted by temperature anomalies and if so, if the responses differ under contrasting precipitation regimes. Our findings show that when the July-October dry-season is anomalously dry, the sensitivity of fires to temperature anomalies is similar regardless of the sign of the anomalies. In contrast, in wet condition, fire risk increases sharply when the dry season is anomalously warm. We also present a characterization of near-term regional climate projections over the next few decades and the implications of continuing global temperature increase in future fire probability in Indonesia.

Heightened fire risk in Indonesia in response to increasing temperature

NASA Astrophysics Data System (ADS)

Fernandes, K.; Baethgen, W.; Verchot, L. V.; Gutierrez-Velez, V.; Pinedo-Vasquez, M.

2016-12-01

In Indonesia, drought driven fires occur typically during the warm phase of the El Niño Southern Oscillation (ENSO), such as those of 1997 and 2015 that resulted in months-long hazardous atmospheric pollution levels in Equatorial Asia and record greenhouse gas emissions. Nonetheless, anomalously active fire seasons have also been observed in non-drought years. In this work, we investigated whether fires are impacted by temperature anomalies and if so, if the responses differ under contrasting precipitation regimes. Our findings show that when the July-October dry-season is anomalously dry, the sensitivity of fires to temperature anomalies is similar regardless of the sign of the anomalies. In contrast, in wet condition, fire risk increases sharply when the dry season is anomalously warm. We also present a characterization of near-term regional climate projections over the next few decades and the implications of continuing global temperature increase in future fire probability in Indonesia.

Do changes in grazing pressure and the degree of shrub encroachment alter the effects of individual shrubs on understorey plant communities and soil function?

PubMed

Soliveres, Santiago; Eldridge, David J

2014-04-01

Shrub canopies in semi-arid environments often produce positive effects on soil fertility, and on the richness and biomass of understorey plant communities. However, both positive and negative effects of shrub encroachment on plant and soil attributes have been reported at the landscape-level. The contrasting results between patch- and landscape-level effects in shrublands could be caused by differences in the degree of shrub encroachment or grazing pressure, both of which are likely to reduce the ability of individual shrubs to ameliorate their understorey environment.We examined how grazing and shrub encroachment (measured as landscape-level shrub cover) influence patch-level effects of shrubs on plant density, biomass and similarity in species composition between shrub understories and open areas, and on soil stability, nutrient cycling, and infiltration in two semi-arid Australian woodlands.Individual shrubs had consistently positive effects on all plant and soil variables (average increase of 23% for all variables). These positive patch-level effects persisted with increasing shrub cover up to our maximum of 50% cover. Heavy grazing negatively affected most of the variables studied (average decline of 11%). It also altered, for some variables, how individual shrubs affected their sub-canopy environment with increasing shrub cover. Thus for species density, biomass and soil infiltration, the positive effect of individual shrubs with increasing shrub cover diminished under heavy grazing. Our study refines predictions of the effects of woody encroachment on ecosystem structure and functioning by showing that heavy grazing, rather than differences in shrub cover, explains the contrasting effects on ecosystem structure and function between individual shrubs and those in dense aggregations. We also discuss how species-specific traits of the encroaching species, such as their height or its ability to fix N, might influence the relationship between their patch-level effects and their cover within the landscape.

Do changes in grazing pressure and the degree of shrub encroachment alter the effects of individual shrubs on understorey plant communities and soil function?

PubMed Central

Soliveres, Santiago; Eldridge, David J.

2015-01-01

Summary Shrub canopies in semi-arid environments often produce positive effects on soil fertility, and on the richness and biomass of understorey plant communities. However, both positive and negative effects of shrub encroachment on plant and soil attributes have been reported at the landscape-level. The contrasting results between patch- and landscape-level effects in shrublands could be caused by differences in the degree of shrub encroachment or grazing pressure, both of which are likely to reduce the ability of individual shrubs to ameliorate their understorey environment. We examined how grazing and shrub encroachment (measured as landscape-level shrub cover) influence patch-level effects of shrubs on plant density, biomass and similarity in species composition between shrub understories and open areas, and on soil stability, nutrient cycling, and infiltration in two semi-arid Australian woodlands. Individual shrubs had consistently positive effects on all plant and soil variables (average increase of 23% for all variables). These positive patch-level effects persisted with increasing shrub cover up to our maximum of 50% cover. Heavy grazing negatively affected most of the variables studied (average decline of 11%). It also altered, for some variables, how individual shrubs affected their sub-canopy environment with increasing shrub cover. Thus for species density, biomass and soil infiltration, the positive effect of individual shrubs with increasing shrub cover diminished under heavy grazing. Synthesis Our study refines predictions of the effects of woody encroachment on ecosystem structure and functioning by showing that heavy grazing, rather than differences in shrub cover, explains the contrasting effects on ecosystem structure and function between individual shrubs and those in dense aggregations. We also discuss how species-specific traits of the encroaching species, such as their height or its ability to fix N, might influence the relationship between their patch-level effects and their cover within the landscape. PMID:25914435

Internal curvature signal and noise in low- and high-level vision

PubMed Central

Grabowecky, Marcia; Kim, Yee Joon; Suzuki, Satoru

2011-01-01

How does internal processing contribute to visual pattern perception? By modeling visual search performance, we estimated internal signal and noise relevant to perception of curvature, a basic feature important for encoding of three-dimensional surfaces and objects. We used isolated, sparse, crowded, and face contexts to determine how internal curvature signal and noise depended on image crowding, lateral feature interactions, and level of pattern processing. Observers reported the curvature of a briefly flashed segment, which was presented alone (without lateral interaction) or among multiple straight segments (with lateral interaction). Each segment was presented with no context (engaging low-to-intermediate-level curvature processing), embedded within a face context as the mouth (engaging high-level face processing), or embedded within an inverted-scrambled-face context as a control for crowding. Using a simple, biologically plausible model of curvature perception, we estimated internal curvature signal and noise as the mean and standard deviation, respectively, of the Gaussian-distributed population activity of local curvature-tuned channels that best simulated behavioral curvature responses. Internal noise was increased by crowding but not by face context (irrespective of lateral interactions), suggesting prevention of noise accumulation in high-level pattern processing. In contrast, internal curvature signal was unaffected by crowding but modulated by lateral interactions. Lateral interactions (with straight segments) increased curvature signal when no contextual elements were added, but equivalent interactions reduced curvature signal when each segment was presented within a face. These opposing effects of lateral interactions are consistent with the phenomena of local-feature contrast in low-level processing and global-feature averaging in high-level processing. PMID:21209356

Immunophenotyping of Monocytes During Human Sepsis Shows Impairment in Antigen Presentation: A Shift Toward Nonclassical Differentiation and Upregulation of FcγRi-Receptor.

PubMed

Ferreira da Mota, Nadijane Valeria; Brunialti, Milena Karina Colo; Santos, Sidneia Sousa; Machado, Flavia Ribeiro; Assunçao, Murillo; de Azevedo, Luciano Cesar Pontes; Salomao, Reinaldo

2017-12-05

Monocytes and macrophages are pivotal in the host response to sepsis, recognizing the infecting microorganism and triggering an inflammatory response. These functions are, at least in part, modulated by the expression of cell surface receptors. We aimed to characterize the monocyte phenotype from septic patients during an ongoing sepsis process and its association with clinical outcomes. Sixty-one septic patients and 31 healthy volunteers (HVs) were enrolled in the study. Samples were obtained from patients at baseline (D0, N = 61), and after 7 (D7, N = 36) and 14 days of therapy (D14, N = 22). Monocytes from septic patients presented decreased expression of CD86, HLA-DR, CD200R, CCR2, CXCR2, and CD163 compared with HV monocytes. In contrast, the PD-1, PD-L1, CD206, CD64, and CD16 expression levels were upregulated in patients. HLA-DR, CD64, PD-1, and PD-L1 expression levels were higher in survivors than in nonsurvivors. Increased CD86, HLA-DR, and CXCR2 expression levels were observed in follow-up samples; in contrast, CD64 and CD16 GMFI decreased over time. In conclusion, monocytes from septic patients show antigen presentation impairment as characterized by decreased HLA-DR and costimulatory CD86 expression and increased PD-1 and PD-L1 expression. On the contrary, increased monocyte inflammatory and phagocytic activities may be inferred by the increased CD16 and CD64 expression. We found conflicting results regarding differentiation toward the M2 phenotype, with increased CD206 expression and decreased CD163 expression on monocytes from septic patients, whereas the subset of nonclassical monocytes was demonstrated by increased CD16.

Distribution and activity levels of matrix metalloproteinase 2 and 9 in canine and feline osteosarcoma

PubMed Central

Gebhard, Christiane; Fuchs-Baumgartinger, Andrea; Razzazi-Fazeli, Ebrahim; Miller, Ingrid; Walter, Ingrid

2016-01-01

Overexpression of matrix metalloproteinases (MMPs) has been associated with increased tumor aggressiveness and metastasis dissemination. We investigated whether the contrasting metastatic behavior of feline and canine osteosarcoma is related to levels and activities of MMP2 and MMP9. Zymography and immunohistochemistry were used to determine expression levels of MMP2 and MMP9 in canine and feline osteosarcoma. Using immunohistochemistry, increased MMP9 levels were identified in most canine osteosarcomas, whereas cat samples more often displayed moderate levels. High levels of pro-MMP9, pro-MMP2, and active MMP2 were detected by gelatin zymography in both species, with significantly higher values for active MMP2 in canine osteosarcoma. These findings indicate that MMP2 is probably involved in canine and feline osteosarcoma and their expression and activity could be associated with the different metastatic behavior of canine and feline osteosarcoma. PMID:26733734

Distribution and activity levels of matrix metalloproteinase 2 and 9 in canine and feline osteosarcoma.

PubMed

Gebhard, Christiane; Fuchs-Baumgartinger, Andrea; Razzazi-Fazeli, Ebrahim; Miller, Ingrid; Walter, Ingrid

2016-01-01

Overexpression of matrix metalloproteinases (MMPs) has been associated with increased tumor aggressiveness and metastasis dissemination. We investigated whether the contrasting metastatic behavior of feline and canine osteosarcoma is related to levels and activities of MMP2 and MMP9. Zymography and immunohistochemistry were used to determine expression levels of MMP2 and MMP9 in canine and feline osteosarcoma. Using immunohistochemistry, increased MMP9 levels were identified in most canine osteosarcomas, whereas cat samples more often displayed moderate levels. High levels of pro-MMP9, pro-MMP2, and active MMP2 were detected by gelatin zymography in both species, with significantly higher values for active MMP2 in canine osteosarcoma. These findings indicate that MMP2 is probably involved in canine and feline osteosarcoma and their expression and activity could be associated with the different metastatic behavior of canine and feline osteosarcoma.

A double-blind, placebo-controlled study on the effects of lutein and zeaxanthin on photostress recovery, glare disability, and chromatic contrast.

PubMed

Hammond, Billy R; Fletcher, Laura M; Roos, Franz; Wittwer, Jonas; Schalch, Wolfgang

2014-12-02

Past studies have shown that higher macular pigment optical density (MPOD) and lutein (L) and zeaxanthin (Z) supplementation are related to improvements in glare disability, photostress recovery, and chromatic contrast. This study assessed those links using a randomized, double-blind, placebo-controlled design. The visual effects of 1 year of supplementing L (10 mg/d) and Z (2 mg/d) were investigated. One hundred fifteen young, healthy subjects were recruited and randomized into the study (58 received placebo, 57 L+Z). Several dependent measures were collected at baseline and then once every 3 months: serum L and Z measured by HPLC chromatography; MPOD measured using customized heterochromatic flicker photometry; photostress recovery assessed by measuring the time needed to recover visual acquisition of a grating target after 30 seconds of an intense xenon white flash exposure; glare disability evaluated as the energy in a surrounding annulus necessary to veil a central grating target; and chromatic contrast assessed by measuring thresholds for a yellow grating target superposed on a 460-nm background. Macular pigment optical density increased significantly versus placebo at all eccentricities (10, 30, 60, and 105 minutes from the center of the macula). Serum L and Z also increased significantly by the first follow-up visit (at 3 months), and remained elevated throughout the intervention period of 1 year. Chromatic contrast and photostress recovery time improved significantly versus placebo. Glare disability was correlated with macular pigment density throughout the study period but did not increase significantly in the treated group. Daily supplementation with L+Z resulted in significant increase in serum levels and MPOD and improvements in chromatic contrast and recovery from photostress. These results are consistent with past studies showing that increasing MPOD leads to improved visual performance. (ClinicalTrials.gov number, NCT00909090.). Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Prenatal glucocorticoid programming of brain corticosteroid receptors and corticotrophin-releasing hormone: possible implications for behaviour.

PubMed

Welberg, L A; Seckl, J R; Holmes, M C

2001-01-01

Glucocorticoids may underlie the association between low birth weight and adult disorders such as hypertension, type 2 diabetes and affective dysfunction. We investigated the behavioural and molecular consequences of two paradigms of prenatal dexamethasone administration in rats. Rats received dexamethasone (100 microg/kg per day) throughout pregnancy (DEX1-3), in the last third of pregnancy only (DEX3) or vehicle. Both dexamethasone treatments reduced birth weight, only DEX1-3 offspring had reduced body weight in adulthood. In adult offspring, both prenatal dexamethasone paradigms reduced exploratory behaviour in an open field. In contrast, only DEX3 reduced exploration in an elevated plus-maze and impaired behavioural responses and learning in a forced-swim test. This behavioural inhibition may reflect increased baseline corticotrophin-releasing hormone mRNA levels (30% higher) in the central nucleus of the amygdala in both dexamethasone-exposed groups. Adult DEX3 offspring also showed increased corticotrophin-releasing hormone mRNA with unaltered glucocorticoid receptor mRNA in the hypothalamic paraventricular nucleus and reduced hippocampal glucocorticoid- and mineralocorticoid receptor mRNA expression, suggesting reduced hippocampal sensitivity to glucocorticoid suppression of the stress axis. In contrast, DEX1-3 rats had no changes in hippocampal corticosteroid receptors, but showed increased mRNA levels for both receptors in the basolateral nucleus of the amygdala. From this data we suggest that prenatal glucocorticoid exposure programs behavioural inhibition perhaps via increased amygdalar corticotrophin-releasing hormone levels, while DEX3 also impairs coping and learning in aversive situations, possibly via altered hippocampal corticosteroid receptor levels. Overexposure to glucocorticoids, especially late in gestation, may explain the link between reduced early growth and adult affective dysfunction.

Carotenoid accumulation in postharvest "Cara Cara" navel orange (Citrus sinensis Osbeck) fruits stored at different temperatures was transcriptionally regulated in a tissue-dependent manner.

PubMed

Tao, Nengguo; Wang, Changfeng; Xu, Juan; Cheng, Yunjiang

2012-09-01

The main objective of this work was to investigate the effect of storage temperature (4 and 20 °C) on carotenoid accumulation and on the expression levels of seven carotenoid biosynthetic genes (Psy, Pds, Zds, Lcyb, Lcye, Hyb and Zep) in postharvest 'Cara Cara' navel orange (C. sinensis Osbeck) fruits. Storage at 20 °C rapidly increased the carotenoid content in the peel, whereas the content remained unchanged in the pulp before 35 days of storage. By contrast, storage at 4 °C maintained the carotenoid content in the peel before 35 days of storage, after which it slightly increased as time progressed. However, the content in the pulp gradually increased over the entire storage period. In the peel, the gene expressions of Psy and Lcyb were up-regulated at 20 °C but remained unchanged at 4 °C. In addition, the gene expressions of Zds, Hyb, and Zep were repressed at both temperatures before the early storage, followed by a rapid increase only at 20 °C. Then the expressions remained constant level at both temperatures, with the expression level at 20 °C higher than that at 4 °C. Low temperature (4 °C) apparently induced the expression of all the test carotenoid biosynthetic genes in the pulp, in contrast to the nearly stable level at 20 °C. Our present study suggests that the carotenoid biosynthesis in postharvest 'Cara Cara' fruits is transcriptionally regulated, and storage temperature affects the carotenoid accumulation and gene expression in a tissue-dependent manner. Temperature could affect the carotenoid biosynthesis in postharvest 'Cara Cara' fruits in a tissue-dependent manner. The carotenoid biosynthesis in postharvest 'Cara Cara' fruits was transcriptionally regulated by correlated genes.

Benefits and Limitations of Low-kV Macromolecular Imaging of Frozen-Hydrated Biological Samples

PubMed Central

Majorovits, Endre; Angert, Isabel; Kaiser, Ute; Schröder, Rasmus R.

2016-01-01

Object contrast is one of the most important parameters of macromolecular imaging. Low-voltage transmission electron microscopy has shown an increased atom contrast for carbon materials, indicating that amplitude contrast contributions increase at a higher rate than phase contrast and inelastic scattering. Here, we studied image contrast using ice-embedded tobacco mosaic virus particles as test samples at 20–80 keV electron energy. The particles showed the expected increase in contrast for lower energies, but at the same time the 2.3-nm-resolution measure decayed more rapidly. We found a pronounced signal loss below 60 keV, and therefore we conclude that increased inelastic scattering counteracts increased amplitude contrast. This model also implies that as long as the amplitude contrast does not increase with resolution, beam damage and multiple scattering will always win over increased contrast at the lowest energies. Therefore, we cannot expect that low-energy imaging of conventionally prepared samples would provide better data than state-of-the-art 200–300 keV imaging. PMID:26910420

Dynamics of vitellogenin and vitellogenesis-inhibiting hormone levels in adult and subadult whiteleg shrimp, Litopenaeus vannamei: relation to molting and eyestalk ablation.

PubMed

Kang, Bong Jung; Okutsu, Tomoyuki; Tsutsui, Naoaki; Shinji, Junpei; Bae, Sun-Hye; Wilder, Marcy N

2014-01-01

Levels of vitellogenin (VG) and vitellogenesis-inhibiting hormone (VIH) in the whiteleg shrimp, Litopenaeus vannamei, were measured by time-resolved fluoroimmunoassay in relation to the molting cycle and ovarian maturation induced by eyestalk ablation. During the molt cycle, VG mRNA expression levels and VG concentrations showed similar patterns of fluctuation. VG levels increased significantly at early intermolt (stage C0) in adults, but not in subadults. Unilateral and bilateral eyestalk ablation increased VG levels in adults, whereas only bilateral eyestalk ablation affected subadults. VIH levels showed contrasting patterns between adults and subadults. In adults, levels were high in late postmolt adults (stage B) and then low thereafter, whereas they increased from postmolt (stage A) to intermolt (stage C0) in subadults and remained high. Unilateral eyestalk ablation increased VIH levels 10 days following ablation in adults, after which levels decreased at 20 days. VIH levels decreased from 10 to 20 days after bilateral ablation. Both unilateral and bilateral ablation led to increased VIH levels in subadults. Eyestalk ablation induced ovarian maturation, but did not reduce VIH concentrations in the hemolymph. This phenomenon was perhaps due to other crustacean hyperglycemic hormone peptides having cross-reactivity with VIH antibodies. This is the first report to quantify concentrations of VG and VIH together in L. vannamei hemolymph, and to examine their relative dynamics.

Functionally distinct roles for different miR-155 expression levels through contrasting effects on gene expression, in acute myeloid leukaemia.

PubMed

Narayan, N; Morenos, L; Phipson, B; Willis, S N; Brumatti, G; Eggers, S; Lalaoui, N; Brown, L M; Kosasih, H J; Bartolo, R C; Zhou, L; Catchpoole, D; Saffery, R; Oshlack, A; Goodall, G J; Ekert, P G

2017-04-01

Enforced expression of microRNA-155 (miR-155) in myeloid cells has been shown to have both oncogenic or tumour-suppressor functions in acute myeloid leukaemia (AML). We sought to resolve these contrasting effects of miR-155 overexpression using murine models of AML and human paediatric AML data sets. We show that the highest miR-155 expression levels inhibited proliferation in murine AML models. Over time, enforced miR-155 expression in AML in vitro and in vivo, however, favours selection of intermediate miR-155 expression levels that results in increased tumour burden in mice, without accelerating the onset of disease. Strikingly, we show that intermediate and high miR-155 expression also regulate very different subsets of miR-155 targets and have contrasting downstream effects on the transcriptional environments of AML cells, including genes involved in haematopoiesis and leukaemia. Furthermore, we show that elevated miR-155 expression detected in paediatric AML correlates with intermediate and not high miR-155 expression identified in our experimental models. These findings collectively describe a novel dose-dependent role for miR-155 in the regulation of AML, which may have important therapeutic implications.

Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

PubMed

Livingstone, I A T; Tarbert, C M; Giardini, M E; Bastawrous, A; Middleton, D; Hamilton, R

2016-01-01

Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out-performed ETDRS charts in terms of photometric compliance with high contrast acuity standards.

Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices

PubMed Central

Livingstone, I. A. T.; Tarbert, C. M.; Giardini, M. E.; Bastawrous, A.; Middleton, D.; Hamilton, R.

2016-01-01

Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer’s recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out-performed ETDRS charts in terms of photometric compliance with high contrast acuity standards. PMID:27002333

Leakage detection on CT myelography for targeted epidural blood patch in spontaneous cerebrospinal fluid leaks: calcified or ossified spinal lesions ventral to the thecal sac.

PubMed

Yoshida, Hiroki; Takai, Keisuke; Taniguchi, Makoto

2014-09-01

The purpose of this study was to describe significant CT myelography findings for determination of the leak site and outcome of targeted epidural blood patch (EBP) in patients with spontaneous CSF leaks. During 2005-2013, spontaneous CSF leaks were diagnosed for 12 patients with orthostatic headaches. The patients received targeted EBP on the basis of CT myelography assessments. Computed tomography myelograms revealed ventral extradural collection of contrast medium distributed over multiple spinal levels (average 16 levels). Intraforaminal contrast medium extravasations were observed at multiple spinal levels (average 8.2 levels). For 8 (67%) of 12 patients, spinal lesions were noted around the thecal sac and included calcified discs with osteophytes, an ossified posterior longitudinal ligament, and an ossified yellow ligament; lesions were mostly located ventral to the thecal sac and were in close contact with the dura mater. The levels of these spinal lesions were considered potential leak sites and were targeted for EBP. For the remaining 4 patients who did not have definite spinal lesions around the thecal sac, leak site determination was based primarily on the contrast gradient hypothesis. The authors hypothesized that the concentration of extradural contrast medium would be the greatest and the same as that of intradural contrast medium at the leak site but that it would decrease with increased distance from the leak site according to the contrast gradient. Epidural blood patch was placed at the level of spinal lesions and/or of the greatest and same concentration of contrast medium between the intradural and extradural spaces. For 10 of the 12 patients, the orthostatic headaches decreased significantly within a week of EBP and disappeared within a month. For the remaining 2 patients, headaches persisted and medical treatment was required for several months. For 3 patients, thick chronic subdural hematomas caused severe headaches and/or disturbed consciousness because of the mass effect of the hematomas, which were removed by bur hole drainage surgery. For 1 patient, bur hole drainage before EBP on the day of admission to hospital resulted in subdural tension pneumocephalus. The patient's headache immediately disappeared after EBP, and the hematoma did not recur. The other 2 patients underwent EBP followed by bur hole drainage, which resulted in improvements and disappearance of the hematomas. Over the follow-up period (mean 39 months), no CSF leaks or chronic subdural hematomas had recurred in any patient after EBP; by the final follow-up visit, all patients had returned to their jobs. The most significant finding of this study was that spinal ventral calcified or ossified lesions, which may be associated with a dural tear, were present in approximately 70% of patients. Targeted EBP to these lesions resulted in good outcomes.

Alcohol Withdrawal-Induced Seizure Susceptibility is Associated with an Upregulation of CaV1.3 Channels in the Rat Inferior Colliculus

PubMed Central

Akinfiresoye, Luli R.; Allard, Joanne S.; Lovinger, David M.

2015-01-01

Background: We previously reported increased current density through L-type voltage-gated Ca2+ (CaV1) channels in inferior colliculus (IC) neurons during alcohol withdrawal. However, the molecular correlate of this increased CaV1 current is currently unknown. Methods: Rats received three daily doses of ethanol every 8 hours for 4 consecutive days; control rats received vehicle. The IC was dissected at various time intervals following alcohol withdrawal, and the mRNA and protein levels of the CaV1.3 and CaV1.2 α1 subunits were measured. In separate experiments, rats were tested for their susceptibility to alcohol withdrawal–induced seizures (AWS) 3, 24, and 48 hours after alcohol withdrawal. Results: In the alcohol-treated group, AWS were observed 24 hours after withdrawal; no seizures were observed at 3 or 48 hours. No seizures were observed at any time in the control-treated rats. Compared to control-treated rats, the mRNA level of the CaV1.3 α1 subunit was increased 1.4-fold, 1.9-fold, and 1.3-fold at 3, 24, and 48 hours, respectively. In contrast, the mRNA level of the CaV1.2 α1 subunit increased 1.5-fold and 1.4-fold at 24 and 48 hours, respectively. At 24 hours, Western blot analyses revealed that the levels of the CaV1.3 and CaV1.2 α1 subunits increased by 52% and 32%, respectively, 24 hours after alcohol withdrawal. In contrast, the CaV1.2 and CaV1.3 α1 subunits were not altered at either 3 or 48 hours during alcohol withdrawal. Conclusions: Expression of the CaV1.3 α1 subunit increased in parallel with AWS development, suggesting that altered L-type CaV1.3 channel expression is an important feature of AWS pathogenesis. PMID:25556199

Tolvaptan rescue contrast-induced acute kidney injury: A case report.

PubMed

Lee, Wei-Chieh; Fang, Hsiu-Yu; Fang, Chih-Yuan

2018-04-01

Contrast-induced acute kidney injury is one of the most serious adverse effects of contrast media and is related to three distinct but interacting mechanisms: medullary ischemia, formation of reactive oxygen species and direct tubular cell toxicity, especially in the patients with chronic kidney disease. The strategies of treatment, including stabilization of hemodynamic parameters and maintenance of normal fluid and electrolyte balance, were similar to the management of other types of acute kidney injury. A 58-year-old woman experienced acute oligouria after complex percutaneous coronary intervention for multiple vessel coronary artery disease. Chest radiography showed pulmonary congestion and hyponatremia was noted after fluid hydration for suspicious contrast-induced nephropathy. Oral tolvaptan, at 15mg per day, was used for three days. Urine output increased gradually and symptoms relieved one day later after using tolvaptan. Serum creatinine also improved to baseline level one week later after this event. Here, we reported an interesting case about contrast-induced acute kidney injury and hypervolemic hyponatremia, where tolvaptan was used to rescue the oliguric phase. Tolvaptan could be considered to use for contrast-induced acute kidney injury and had possibility of prevention from hemodialysis. Larger studies are still needed to investigate the role of tolvaptan in rescuing the oliguric phase in contrast-induced acute kidney injury.

Polyploidization without mitosis improves in vivo liver transduction with lentiviral vectors.

PubMed

Pichard, Virginie; Couton, Dominique; Desdouets, Chantal; Ferry, Nicolas

2013-02-01

Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy.

Polyploidization Without Mitosis Improves In Vivo Liver Transduction With Lentiviral Vectors

PubMed Central

Couton, Dominique; Desdouets, Chantal; Ferry, Nicolas

2013-01-01

Abstract Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy. PMID:23249390

Heat shock protein defenses in the neo- and allocortex of the telencephalon

PubMed Central

Posimo, Jessica M.; Weilnau, Justin N.; Gleixner, Amanda M.; Broeren, Matthew T.; Weiland, Nicole L.; Brodsky, Jeffrey L.; Wipf, Peter; Leak, Rehana K.

2015-01-01

The telencephalic allocortex develops protein inclusions before the neocortex in many age-related proteinopathies. One major defense mechanism against proteinopathic stress is the heat shock protein (Hsp) network. We therefore contrasted Hsp defenses in stressed primary neo- and allocortical cells. Neocortical neurons were more resistant to the proteasome inhibitor MG132 than neurons from three allocortical subregions: entorhinal cortex, piriform cortex, and hippocampus. However, allocortical neurons exhibited higher MG132-induced increases in Hsp70 and Hsc70. MG132-treated allocortical neurons also exhibited greater levels of protein ubiquitination. Inhibition of Hsp70/Hsc70 activity synergistically exacerbated MG132 toxicity in allocortical neurons more than neocortical neurons, suggesting that the allocortex is more reliant on these Hsp defenses. In contrast, astrocytes harvested from neo- or allocortex did not differ in their response to Hsp70/Hsc70 inhibition. Consistent with the idea that chaperones are maximally engaged in allocortical neurons, an increase in Hsp70/Hsc70 activity was protective only in neocortical neurons. Finally, the levels of select Hsps were altered in neocortex and allocortex in vivo with aging. PMID:25771395

Optimal CO2 mitigation under damage risk valuation

NASA Astrophysics Data System (ADS)

Crost, Benjamin; Traeger, Christian P.

2014-07-01

The current generation has to set mitigation policy under uncertainty about the economic consequences of climate change. This uncertainty governs both the level of damages for a given level of warming, and the steepness of the increase in damage per warming degree. Our model of climate and the economy is a stochastic version of a model employed in assessing the US Social Cost of Carbon (DICE). We compute the optimal carbon taxes and CO2 abatement levels that maximize welfare from economic consumption over time under different risk states. In accordance with recent developments in finance, we separate preferences about time and risk to improve the model's calibration of welfare to observed market interest. We show that introducing the modern asset pricing framework doubles optimal abatement and carbon taxation. Uncertainty over the level of damages at a given temperature increase can result in a slight increase of optimal emissions as compared to using expected damages. In contrast, uncertainty governing the steepness of the damage increase in temperature results in a substantially higher level of optimal mitigation.

Progesterone receptor knockout mice have an improved glucose homeostasis secondary to -cell proliferation

NASA Astrophysics Data System (ADS)

Picard, Frédéric; Wanatabe, Mitsuhiro; Schoonjans, Kristina; Lydon, John; O'Malley, Bert W.; Auwerx, Johan

2002-11-01

Gestational diabetes coincides with elevated circulating progesterone levels. We show that progesterone accelerates the progression of diabetes in female db/db mice. In contrast, RU486, an antagonist of the progesterone receptor (PR), reduces blood glucose levels in both female WT and db/db mice. Furthermore, female, but not male, PR-/- mice had lower fasting glycemia than PR+/+ mice and showed higher insulin levels on glucose injection. Pancreatic islets from female PR-/- mice were larger and secreted more insulin consequent to an increase in -cell mass due to an increase in -cell proliferation. These findings demonstrate an important role of progesterone signaling in insulin release and pancreatic function and suggest that it affects the susceptibility to diabetes.

Gut hormone release after intestinal resection.

PubMed Central

Besterman, H S; Adrian, T E; Mallinson, C N; Christofides, N D; Sarson, D L; Pera, A; Lombardo, L; Modigliani, R; Bloom, S R

1982-01-01

To investigate the possible role of gut and pancreatic hormones in the adaptive responses to gut resection, plasma concentrations of the circulating hormones were measured, in response to a test breakfast, in patients with either small or large intestinal resection and in healthy control subjects. In 18 patients with partial ileal resection a significant threefold rise was found in basal and postprandial levels of pancreatic polypeptide, a fourfold increase in motilin, and more than a twofold increase in gastrin and enteroglucagon levels compared with healthy controls. In contrast, nine patients with colonic resection had a threefold rise in levels of pancreatic polypeptide only. One or more of these peptides may have a role in stimulating the adaptive changes found after gut resection. PMID:7117905

Lipid profiles in the untreated patients with Hashimoto thyroiditis and the effects of thyroxine treatment on subclinical hypothyroidism with Hashimoto thyroiditis.

PubMed

Tagami, Tetsuya; Tamanaha, Tamiko; Shimazu, Satoko; Honda, Kyoko; Nanba, Kazutaka; Nomura, Hidenari; Yoriko, Sakane Ueda; Usui, Takeshi; Shimatsu, Akira; Naruse, Mitsuhide

2010-01-01

To evaluate the prevalence of dyslipidemia in the population of Hashimoto thyroiditis, we reviewed medical records on the consecutive 1181 cases with adult Hashimoto thyroiditis and 830 cases were adopted for the study. First, the serum TSH level increased and serum free T4 level decreased, slightly but significantly, with increasing age. There were significant positive correlations between serum TSH levels and lipid parameters such as total cholesterol (TC), triglyceride (TG), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), non-HDL-C and LDL-C/HDL-C ratio (L/H). In contrast, there were significant negative correlations between serum free T4 levels and all of these lipid parameters. According to the thyroid function, the cases were classified into 4 groups such as thyrotoxicosis (TT), euthyroidism (EU), subclinical hypothyroidism (SH) and overt hypothyroidism (OH). TC, HDL-C, non-HDL-C and LDL-C of TT were significantly lower than those in EU. In contrast, TC, TG, non-HDL-C, LDL-C, L/H and age of OH were significantly higher than those in EU. Interestingly, LDL-C and L/H of SH were significantly higher compared with EU. Thirty-two of SH patients were treated with small doses of levothyroxine and the effects on the lipid profile were examined. The TC, non-HDL-C, LDL-C and L/H were significantly decreased after treatment. In conclusion, the prevalence of dyslipidemia increases along with hypofunction of the thyroid and T4 replacement therapy may improve lipid profile in the cases of SH with Hashimoto thyroiditis.

Regional TNFα mapping in the brain reveals the striatum as a neuroinflammatory target after ventricular fibrillation cardiac arrest in rats☆

PubMed Central

Janata, Andreas; Magnet, Ingrid A.M.; Uray, Thomas; Stezoski, Jason P.; Janesko-Feldman, Keri; Tisherman, Samuel A.; Kochanek, Patrick M.; Drabek, Tomas

2014-01-01

Cardiac arrest (CA) triggers neuroinflammation that could play a role in a delayed neuronal death. In our previously established rat model of ventricular fibrillation (VF) CA characterized by extensive neuronal death, we tested the hypothesis that individual brain regions have specific neuroinflammatory responses, as reflected by regional brain tissue levels of tumor necrosis factor (TNF)α and other cytokines. In a prospective study, rats were randomized to 6 min (CA6), 8 min (CA8) or 10 min (CA10) of VF CA, or sham group. Cortex, striatum, hippocampus and cerebellum were evaluated for TNFα and interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12 and interferon gamma at 3 h, 6 h or 14 d after CA by ELISA and Luminex. Immunohistochemistry was used to determine the cell source of TNFα. CA resulted in a selective TNFα response with significant regional and temporal differences. At 3 h after CA, TNFα-levels increased in all regions depending on the duration of the insult. The most pronounced increase was observed in striatum that showed 20-fold increase in CA10 vs. sham, and 3-fold increase vs. CA6 or CA8 group, respectively (p < 0.01). TNFα levels in striatum decreased between 3 h and 6 h, but increased in other regions between 3 h and 14 d. TNFα levels remained twofold higher in CA6 vs. shams across brain regions at 14 d (p < 0.01). In contrast to pronounced TNFα response, other cytokines showed only a minimal increase in CA6 and CA8 groups vs. sham in all brain regions with the exception that IL-1β increased twofold in cerebellum and striatum (p < 0.01). TNFα colocalized with neurons. In conclusion, CA produced a duration-dependent acute TNFα response, with dramatic increase in the striatum where TNFα colocalized with neurons. Increased TNFα levels persist for at least two weeks. This TNFα surge contrasts the lack of an acute increase in other cytokines in brain after CA. Given that striatum is a selectively vulnerable brain region, our data suggest possible role of neuronal TNFα in striatum after CA and identify therapeutic targets for future experiments. PMID:24530249

[Features of influence adenosine, AMP and hyperadrenalinemiya on the immune status, metabolic enzymes of purine nucleotides and the antioxidant defense system].

PubMed

Tapbergenov, S O; Sovetov, B S; Tapbergenov, A T

2016-11-01

Administration of a large dose of adrenaline (4 mg/kg 60 min before analysis) increased blood levels of total leukocytes, lymphocytes, decreased T-cell suppressors, leukocyte migration inhibition reaction (LMIR) and NBT test, but increased the level of conjugated dienes (CD). Administration of AMPand adenosine increased levels of total leukocytes, lymphocytes, T- lymphocytes, T-helpers, decreased the level of malondialdehyde (MDA), LMIR, and T-cell suppressors. Sympathetic hyperactivation induced by administration of a large dose of adrenaline (4 mg/kg 60 min before analysis) was accompanied by an increase in heart and liver activities of glutathione peroxidase (GPx), catalase, AMP deaminase (AMPD), and adenosine deaminase (AD). Administration of AMP or adenosine caused a decrease in activities of glutathione reductase (GR), GPx, catalase, a decrease in the MDA level and an increase in activities of AMPD and AD in the heart. In the liver AMP and adenosine also caused a decrease in activities of glutathione reductase (GR), GPx, a decrease in the MDA level and an increase in activities of AMPD and AD. The data obtained suggest that administration of adrenaline, AMP, and adenosine influences activity of enzymes involved in purine nucleotide metabolism. However, in contrast to adrenaline, administration of AMP or adenosine does not provoke stress reaction.

SU-E-I-65: The Joint Commission's Requirements for Annual Diagnostic Physics Testing of Nuclear Medicine Equipment, and a Clinically Relevant Methodology for Testing Low-Contrast Resolution

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

West, W. Geoffrey; Gray, David Clinton

Purpose: To introduce the Joint Commission's requirements for annual diagnostic physics testing of all nuclear medicine equipment, effective 7/1/2014, and to highlight an acceptable methodology for testing lowcontrast resolution of the nuclear medicine imaging system. Methods: The Joint Commission's required diagnostic physics evaluations are to be conducted for all of the image types produced clinically by each scanner. Other accrediting bodies, such as the ACR and the IAC, have similar imaging metrics, but do not emphasize testing low-contrast resolution as it relates clinically. The proposed method for testing low contrast resolution introduces quantitative metrics that are clinically relevant. The acquisitionmore » protocol and calculation of contrast levels will utilize a modified version of the protocol defined in AAPM Report #52. Results: Using the Rose criterion for lesion detection with a SNRpixel = 4.335 and a CNRlesion = 4, the minimum contrast levels for 25.4 mm and 31.8 mm cold spheres were calculated to be 0.317 and 0.283, respectively. These contrast levels are the minimum threshold that must be attained to guard against false positive lesion detection. Conclusion: Low contrast resolution, or detectability, can be properly tested in a manner that is clinically relevant by measuring the contrast level of cold spheres within a Jaszczak phantom using pixel values within ROI's placed in the background and cold sphere regions. The measured contrast levels are then compared to a minimum threshold calculated using the Rose criterion and a CNRlesion = 4. The measured contrast levels must either meet or exceed this minimum threshold to prove acceptable lesion detectability. This research and development activity was performed by the authors while employed at West Physics Consulting, LLC. It is presented with the consent of West Physics, which has authorized the dissemination of the information and/or techniques described in the work.« less

Task effects on BOLD signal correlates of implicit syntactic processing

PubMed Central

Caplan, David

2010-01-01

BOLD signal was measured in sixteen participants who made timed font change detection judgments in visually presented sentences that varied in syntactic structure and the order of animate and inanimate nouns. Behavioral data indicated that sentences were processed to the level of syntactic structure. BOLD signal increased in visual association areas bilaterally and left supramarginal gyrus in the contrast of sentences with object- and subject-extracted relative clauses without font changes in which the animacy order of the nouns biased against the syntactically determined meaning of the sentence. This result differs from the findings in a non-word detection task (Caplan et al, 2008a), in which the same contrast led to increased BOLD signal in the left inferior frontal gyrus. The difference in areas of activation indicates that the sentences were processed differently in the two tasks. These differences were further explored in an eye tracking study using the materials in the two tasks. Issues pertaining to how parsing and interpretive operations are affected by a task that is being performed, and how this might affect BOLD signal correlates of syntactic contrasts, are discussed. PMID:20671983

Task effects on BOLD signal correlates of implicit syntactic processing.

PubMed

Caplan, David

2010-07-01

BOLD signal was measured in sixteen participants who made timed font change detection judgments in visually presented sentences that varied in syntactic structure and the order of animate and inanimate nouns. Behavioral data indicated that sentences were processed to the level of syntactic structure. BOLD signal increased in visual association areas bilaterally and left supramarginal gyrus in the contrast of sentences with object- and subject-extracted relative clauses without font changes in which the animacy order of the nouns biased against the syntactically determined meaning of the sentence. This result differs from the findings in a non-word detection task (Caplan et al, 2008a), in which the same contrast led to increased BOLD signal in the left inferior frontal gyrus. The difference in areas of activation indicates that the sentences were processed differently in the two tasks. These differences were further explored in an eye tracking study using the materials in the two tasks. Issues pertaining to how parsing and interpretive operations are affected by a task that is being performed, and how this might affect BOLD signal correlates of syntactic contrasts, are discussed.

A painful reminder: the role of level and salience of attitude importance in cognitive dissonance.

PubMed

Starzyk, Katherine B; Fabrigar, Leandre R; Soryal, Ashley S; Fanning, Jessie J

2009-01-01

In his seminal book, L. Festinger (1957) emphasized the role of attitude importance in cognitive dissonance. This study (N = 308) explored whether people's use of dissonance reduction strategies differs as a function of level of attitude importance and whether the personal importance of an attitude is salient. Results showed that level and salience of attitude importance interacted to affect high-choice (HC) participants' tendency to use attitude change and trivialization to reduce dissonance. When HC participants were not reminded of the personal importance of their attitude (i.e., it was not salient), they changed their attitudes equally irrespective of attitude importance, but engaged in greater trivialization with increasing levels of importance. In contrast, when attitude importance was salient, HC participants changed their attitudes less with increasing attitude importance and showed no evidence of trivializing under any level of importance.

The regulated in development and DNA damage response 2 (REDD2) gene mediates human monocyte cell death through a reduction in thioredoxin-1 expression.

PubMed

Imen, Jguirim-Souissi; Billiet, Ludivine; Cuaz-Pérolin, Clarisse; Michaud, Nadège; Rouis, Mustapha

2009-05-15

In a previous study, we identified the regulated in development and DNA damage response 2 (REDD2) gene as a highly expressed gene in human atherosclerotic lesions in comparison to normal artery, as well as in cultured human macrophages, and showed its implication in oxidized low-density lipoprotein (LDL)-induced macrophage death sensitivity. In this article, we attempt to identify the mechanism by which REDD2 induces such a phenomenon. Transient transfection of U-937 monocytic cells with a pCI.CMV.REDD2 expression vector increased by approximately twofold the mRNA levels of REDD2 in comparison to control cells transfected with pCI.CMV.GFP. Reactive oxygen species (ROS) production was significantly induced in REDD2-transfected cells compared with control cells (157+/-48 and 100+/-8 arbitrary units/mg cell protein, respectively; p<0.05). Moreover, a significant increase in parameters known to reflect the oxidative modifications of LDL was observed. Among enzymes involved in ROS production or degradation, we found a specific reduction in thioredoxin-1 (Trx-1) mRNA ( approximately 52+/-7% decrease, p<0.01 vs control cells) and protein ( approximately 60+/-4% decrease, p<0.001 vs control cells) levels in cells overexpressing REDD2 in comparison to control cells. In contrast, transfection of U-937 cells with siRNA against REDD2 decreased the mRNA levels of REDD2 by approximately 60% and increased Trx-1 mRNA and protein levels. Moreover, we observed no or a moderate increase in Bax (proapoptotic) and a significant decrease in Bcl2 (antiapoptotic) gene expression in cells that overexpress REDD2 compared to control cells. In addition, we showed that Trx-1 mRNA and protein levels were increased at low H(2)O(2) doses and decreased at higher doses. Interestingly, macrophages isolated from human atherosclerotic lesions differentially express REDD2 and Trx-1. Indeed, in certain patients, levels of REDD2 mRNA were low and those of Trx-1 mRNA were high. In contrast, in other patients, levels of REDD2 were high and levels of Trx-1 mRNA were low.

Isoflurane in contrast to propofol promotes fluid extravasation during cardiopulmonary bypass in pigs.

PubMed

Brekke, Hege Kristin; Hammersborg, Stig Morten; Lundemoen, Steinar; Mongstad, Arve; Kvalheim, Venny Lise; Haugen, Oddbjørn; Husby, Paul

2013-10-01

A highly positive intraoperative fluid balance should be prevented as it negatively impacts patient outcome. Analysis of volume-kinetics has identified an increase in interstitial fluid volume after crystalloid fluid loading during isoflurane anesthesia. Isoflurane has also been associated with postoperative hypoxemia and may be associated with an increase in alveolar epithelial permeability, edema formation, and hindered oxygen exchange. In this article, the authors compare fluid extravasation rates before and during cardiopulmonary bypass (CPB) with isoflurane- versus propofol-based anesthesia. Fourteen pigs underwent 2 h of tepid CPB with propofol (P-group; n = 7) or isoflurane anesthesia (I-group; n = 7). Fluid requirements, plasma volume, colloid osmotic pressures in plasma and interstitial fluid, hematocrit levels, and total tissue water content were recorded, and fluid extravasation rates calculated. Fluid extravasation rates increased in the I-group from the pre-CPB level of 0.27 (0.13) to 0.92 (0.36) ml·kg·min, but remained essentially unchanged in the P-group with significant between-group differences during CPB (pb = 0.002). The results are supported by corresponding changes in interstitial colloid osmotic pressure and total tissue water content. During CPB, isoflurane, in contrast to propofol, significantly contributes to a general increase in fluid shifts from the intravascular to the interstitial space with edema formation and a possible negative impact on postoperative organ function.

Contrasting fire responses to climate and management: insights from two Australian ecosystems.

PubMed

King, Karen J; Cary, Geoffrey J; Bradstock, Ross A; Marsden-Smedley, Jonathan B

2013-04-01

This study explores effects of climate change and fuel management on unplanned fire activity in ecosystems representing contrasting extremes of the moisture availability spectrum (mesic and arid). Simulation modelling examined unplanned fire activity (fire incidence and area burned, and the area burned by large fires) for alternate climate scenarios and prescribed burning levels in: (i) a cool, moist temperate forest and wet moorland ecosystem in south-west Tasmania (mesic); and (ii) a spinifex and mulga ecosystem in central Australia (arid). Contemporary fire activity in these case study systems is limited, respectively, by fuel availability and fuel amount. For future climates, unplanned fire incidence and area burned increased in the mesic landscape, but decreased in the arid landscape in accordance with predictions based on these limiting factors. Area burned by large fires (greater than the 95th percentile of historical, unplanned fire size) increased with future climates in the mesic landscape. Simulated prescribed burning was more effective in reducing unplanned fire activity in the mesic landscape. However, the inhibitory effects of prescribed burning are predicted to be outweighed by climate change in the mesic landscape, whereas in the arid landscape prescribed burning reinforced a predicted decline in fire under climate change. The potentially contrasting direction of future changes to fire will have fundamentally different consequences for biodiversity in these contrasting ecosystems, and these will need to be accommodated through contrasting, innovative management solutions. © 2012 Blackwell Publishing Ltd.

Contrast gain control: a bilinear model for chromatic selectivity.

PubMed

Singer, B; D'Zmura, M

1995-04-01

We report the results of psychophysical experiments on color contrast induction. In earlier work [Vision Res. 34, 3111 (1994)], we showed that modulating the spatial contrast of an annulus in time induces an apparent modulation of the contrast of a central disk, at isoluminance. Here we vary the chromatic properties of disk and annulus systematically in a study of the interactions among the luminance and the color-opponent channels. Results show that induced contrast depends linearly on both disk and annulus contrast, at low and moderate contrast levels. This dependence leads us to propose a bilinear model for color contrast gain control. The model predicts the magnitude and the chromatic properties of induced contrast. In agreement with experimental results, the model displays chromatic selectivity in contrast gain control and a negligible effect of contrast modulation at isoluminance on the appearance of achromatic contrast. We show that the bilinear model for chromatic selectivity may be realized as a feed-forward multiplicative gain control. Data collected at high contrast levels are fit by embellishing the model with saturating nonlinearities in the contrast gain control of each color channel.

F-Box Protein FBX92 Affects Leaf Size in Arabidopsis thaliana.

PubMed

Baute, Joke; Polyn, Stefanie; De Block, Jolien; Blomme, Jonas; Van Lijsebettens, Mieke; Inzé, Dirk

2017-05-01

F-box proteins are part of one of the largest families of regulatory proteins that play important roles in protein degradation. In plants, F-box proteins are functionally very diverse, and only a small subset has been characterized in detail. Here, we identified a novel F-box protein FBX92 as a repressor of leaf growth in Arabidopsis. Overexpression of AtFBX92 resulted in plants with smaller leaves than the wild type, whereas plants with reduced levels of AtFBX92 showed, in contrast, increased leaf growth by stimulating cell proliferation. Detailed cellular analysis suggested that AtFBX92 specifically affects the rate of cell division during early leaf development. This is supported by the increased expression levels of several cell cycle genes in plants with reduced AtFBX92 levels. Surprisingly, overexpression of the maize homologous gene ZmFBX92 in maize had no effect on plant growth, whereas ectopic expression in Arabidopsis increased leaf growth. Expression of a truncated form of AtFBX92 showed that the contrasting effects of ZmFBX92 and AtFBX92 gain of function in Arabidopsis are due to the absence of the F-box-associated domain in the ZmFBX92 gene. Our work reveals an additional player in the complex network that determines leaf size and lays the foundation for identifying putative substrates. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Sclerostin as a potential novel biomarker for aortic valve calcification: an in-vivo and ex-vivo study.

PubMed

Koos, Ralf; Brandenburg, Vincent; Mahnken, Andreas Horst; Schneider, Rebekka; Dohmen, Guido; Autschbach, Rüdiger; Marx, Nikolaus; Kramann, Rafael

2013-05-01

Sclerostin is a key negative regulator of bone formation. It was hypothesized that sclerostin might also play a potential role in the development of aortic valve calcification (AVC). The study aim was to evaluate serum sclerostin levels in patients with different degrees of AVC compared to a healthy control group, and to investigate local sclerostin expression in explanted calcified and non-calcified aortic valves. A prospective cross-sectional study was performed in 115 patients (mean age 74 +/- 7 years) with echocardiographically proven AVC. Sclerostin serum levels were measured using ELISA and compared to values obtained from a healthy control population. For quantification of AVC, all patients of the study cohort underwent non-contrast-enhanced dual-source computed tomography (DSCT). Immunohistochemistry (IHC) staining for sclerostin and mRNA sclerostin expression was analyzed in 10 calcified aortic valves and 10 non-calcified age-matched control valves. Patients with AVC showed significantly higher sclerostin serum levels as compared to healthy controls (0.94 +/- 0.45 versus 0.58 +/- 0.26 ng/ml, p < 0.001). A significant correlation between sclerostin serum levels and Agatston AVC scores as assessed by DSCT was observed (r = 0.62, p < 0.001) in the study cohort. IHC revealed positive sclerostin staining in nine calcified valves, in contrast to negative staining for sclerostin in all non-calcified valves. Quantitative real-time PCR confirmed the increased sclerostin expression on mRNA level, with a significant up-regulation of sclerostin mRNA (fold change 150 +/- 52, p < 0.001) expression being shown in calcified aortic valves compared to non-calcified control valves. Co-staining experiments revealed that sclerostin-expressing cells co-express the major osteogenic transcription factor Runx2 and the extracellular matrix protein osteocalcin. Patients with AVC showed increased sclerostin serum levels compared to a healthy reference population, and it was revealed that the severity of AVC may be linked to increased sclerostin serum levels. Moreover, the PCR and staining data demonstrated an increased sclerostin expression in parallel to prototypic markers of osteogenic transdifferentiation, indicating a role of sclerostin in the valvular calcification process.

Enhanced tocopherol levels during early germination events in Chamaerops humilis var. humilis seeds.

PubMed

Siles, Laura; Alegre, Leonor; Tijero, Verónica; Munné-Bosch, Sergi

2015-10-01

Most angiosperms accumulate vitamin E in the form of tocopherols in seeds, exerting a protective antioxidant role. However, several palm trees principally accumulate tocotrienols, rather than tocopherols, in seeds, as it occurs in other monocots. To unravel the protective role of either tocopherols or tocotrienols against lipid peroxidation during seed germination in Chamaerops humilis var. humilis; seed viability, natural and induced germination capacity, seed water content, malondialdehyde levels (as an indicator of the extent of lipid peroxidation) and vitamin E levels (including both tocopherols and tocotrienols) were examined at various germination phases in a simulated, natural seed bank. At the very early stages of germination (operculum removal), malondialdehyde levels increased 2.8-fold, to decrease later up to 74%, thus indicating a transient lipid peroxidation at early stages of germination. Tocopherol levels were absent in quiescent seeds and did not increase during operculum removal, but increased later presumably dampening malondialdehyde accumulation. Thereafter, tocopherols continued increasing, while lipid peroxidation levels decreased. By contrast, tocotrienols levels remained constant or even decreased as germination progressed, showing no correlation with lipid peroxidation levels. We hypothesize that despite their high tocotrienol content, seeds synthesize tocopherols during germination to protect lipids from peroxidation events. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of spatial attention on invisible stimuli.

PubMed

Shin, Kilho; Stolte, Moritz; Chong, Sang Chul

2009-10-01

The influence of selective attention on visual processing is widespread. Recent studies have demonstrated that spatial attention can affect processing of invisible stimuli. However, it has been suggested that this effect is limited to low-level features, such as line orientations. The present experiments investigated whether spatial attention can influence both low-level (contrast threshold) and high-level (gender discrimination) adaptation, using the same method of attentional modulation for both types of stimuli. We found that spatial attention was able to increase the amount of adaptation to low- as well as to high-level invisible stimuli. These results suggest that attention can influence perceptual processes independent of visual awareness.

Inhibition of deprivation-induced food intake by GABA(A) antagonists: roles of the hypothalamic, endocrine and alimentary mechanisms.

PubMed

Kamatchi, Ganesan L; Rathanaswami, Palaniswami

2012-07-01

The role of gamma amino butyric acid A receptors/neurons of the hypothalamic, endocrine and alimentary systems in the food intake seen in hunger was studied in 20 h food-deprived rats. Food deprivation decreased blood glucose, serum insulin and produced hyperphagia. The hyperphagia was inhibited by subcutaneous or ventromedial hypothalamic administration of gamma amino butyric acid A antagonists picrotoxin or bicuculline. Although results of blood glucose was variable, insulin level was increased by picrotoxin or bicuculline. In contrast, lateral hypothalamic administration of these agents failed to reproduce the above changes. Subcutaneous administration of picrotoxin or bicuculline increased gastric content, decreased gastric motility and small bowel transit. In contrast, ventromedial or lateral hypothalamic administration of picrotoxin or bicuculline failed to alter the gastric content but decreased the small bowel transit. The results of alimentary studies suggest that gamma amino butyric acid neurons of both ventromedial and lateral hypothalamus selectively regulate small bowel transit but not the gastric content. It may be concluded that ventromedial hypothalamus plays a dominant role in the regulation of food intake and that picrotoxin or bicuculline inhibited food intake by inhibiting gamma amino butyric acid receptors of the ventromedial hypothalamus, increasing insulin level and decreasing the gut motility.

Inhibition of deprivation-induced food intake by GABAA antagonists: roles of the hypothalamic, endocrine and alimentary mechanisms

PubMed Central

Kamatchi, Ganesan L.; Rathanaswami, Palaniswami

2012-01-01

The role of gamma amino butyric acid A receptors/neurons of the hypothalamic, endocrine and alimentary systems in the food intake seen in hunger was studied in 20 h food-deprived rats. Food deprivation decreased blood glucose, serum insulin and produced hyperphagia. The hyperphagia was inhibited by subcutaneous or ventromedial hypothalamic administration of gamma amino butyric acid A antagonists picrotoxin or bicuculline. Although results of blood glucose was variable, insulin level was increased by picrotoxin or bicuculline. In contrast, lateral hypothalamic administration of these agents failed to reproduce the above changes. Subcutaneous administration of picrotoxin or bicuculline increased gastric content, decreased gastric motility and small bowel transit. In contrast, ventromedial or lateral hypothalamic administration of picrotoxin or bicuculline failed to alter the gastric content but decreased the small bowel transit. The results of alimentary studies suggest that gamma amino butyric acid neurons of both ventromedial and lateral hypothalamus selectively regulate small bowel transit but not the gastric content. It may be concluded that ventromedial hypothalamus plays a dominant role in the regulation of food intake and that picrotoxin or bicuculline inhibited food intake by inhibiting gamma amino butyric acid receptors of the ventromedial hypothalamus, increasing insulin level and decreasing the gut motility. PMID:22798708

Effect of Light on Anthocyanin Levels in Submerged, Harvested Cranberry Fruit

PubMed Central

Singh, Bal Ram

2004-01-01

Anthocyanins are a group of plant antioxidants known for their therapeutic use. The effects of natural light, red light, and far-red light on individual as well as total anthocyanin content in cranberry fruit (Vaccinium macrocarpon Ait) were examined in an experimental setting designed to mimic water-harvesting conditions. The reversed-phase high-performance liquid chromatography (HPLC) method was used to separate and analyze the anthocyanins. In contrast to the case of the control sample that was kept in the dark, natural light increased the total anthocyanin level by 75.3% and 87.2% after 24 and 48 hours of water immersion, respectively. Red light and far-red light increased the total anthocyanin level by 41.5% and 34.7%, respectively. The amount of each individual anthocyanin increased differently under natural light, red light, and far-red light, suggesting that expressions of enzymes that catalyze the anthocyanin biosynthesis are regulated differently by environments. PMID:15577187

The Economics of Direct versus Indirect Cost Recovery in Sponsored Research. AIR Annual 1984 Forum Paper.

ERIC Educational Resources Information Center

Kutina, Kenneth L.; And Others

The effect of reduced reimbursements by the federal government for indirect research costs was analyzed for the typical academic medical center. The effects of simply cutting indirect cost reimbursement were contrasted with the impact of securing compensating levels of increased direct project support. To determine if the consequences differed as…

Optimism, Social Support, and Adjustment in African American Women with Breast Cancer

PubMed Central

Shelby, Rebecca A.; Crespin, Tim R.; Wells-Di Gregorio, Sharla M.; Lamdan, Ruth M.; Siegel, Jamie E.; Taylor, Kathryn L.

2013-01-01

Past studies show that optimism and social support are associated with better adjustment following breast cancer treatment. Most studies have examined these relationships in predominantly non-Hispanic White samples. The present study included 77 African American women treated for nonmetastatic breast cancer. Women completed measures of optimism, social support, and adjustment within 10-months of surgical treatment. In contrast to past studies, social support did not mediate the relationship between optimism and adjustment in this sample. Instead, social support was a moderator of the optimism-adjustment relationship, as it buffered the negative impact of low optimism on psychological distress, well-being, and psychosocial functioning. Women with high levels of social support experienced better adjustment even when optimism was low. In contrast, among women with high levels of optimism, increasing social support did not provide an added benefit. These data suggest that perceived social support is an important resource for women with low optimism. PMID:18712591

Megavoltage planar and cone-beam imaging with low-Z targets: dependence of image quality improvement on beam energy and patient separation.

PubMed

Robar, James L; Connell, Tanner; Huang, Weihong; Kelly, Robin G

2009-09-01

The purpose of this study is to investigate the improvement of megavoltage planar and cone-beam CT (CBCT) image quality with the use of low atomic number (Z) external targets in the linear accelerator. In this investigation, two experimental megavoltage imaging beams were generated by using either 3.5 or 7.0 MeV electrons incident on aluminum targets installed above the level of the carousel in a linear accelerator (2100EX, Varian Medical, Inc., Palo Alto, CA). Images were acquired using an amorphous silicon detector panel. Contrast-to-noise ratio (CNR) in planar and CBCT images was measured as a function of dose and a comparison was made between the imaging beams and the standard 6 MV therapy beam. Phantoms of variable diameter were used to examine the loss of contrast due to beam hardening. Porcine imaging was conducted to examine qualitatively the advantages of the low-Z target approach in CBCT. In CBCT imaging CNR increases by factors as high as 2.4 and 4.3 for the 7.0 and 3.5 MeV/Al beams, respectively, compared to images acquired with 6 MV. Similar factors of improvement are observed in planar imaging. For the imaging beams, beam hardening causes a significant loss of the contrast advantage with increasing phantom diameter; however, for the 3.5 MeV/Al beam and a phantom diameter of 25 cm, a contrast advantage remains, with increases of contrast by factors of 1.5 and 3.4 over 6 MV for bone and lung inhale regions, respectively. The spatial resolution is improved slightly in CBCT images for the imaging beams. CBCT images of a porcine cranium demonstrate qualitatively the advantages of the low-Z target approach, showing greater contrast between tissues and improved visibility of fine detail. The use of low-Z external targets in the linear accelerator improves megavoltage planar and CBCT image quality significantly. CNR may be increased by a factor of 4 or greater. Improvement of the spatial resolution is also apparent.

Iron-Regulated Expression of Alginate Production, Mucoid Phenotype, and Biofilm Formation by Pseudomonas aeruginosa

PubMed Central

Wiens, Jacinta R.; Vasil, Adriana I.; Schurr, Michael J.; Vasil, Michael L.

2014-01-01

ABSTRACT Pseudomonas aeruginosa strains of non-cystic fibrosis (non-CF) origin do not produce significant amounts of extracellular alginate and are nonmucoid. In CF, such isolates can become mucoid through mutation of one of the genes (mucA, mucB, mucC, or mucD) that produce regulatory factors that sequester AlgU, required for increased expression of alginate genes. Mutation of the muc genes in the nonmucoid PAO1, PA14, PAKS-1, and Ps388 strains led to increased levels of extracellular alginate and an obvious mucoid phenotype, but only under iron-limiting growth conditions (≤5 µM), not under iron-replete conditions (≥10 µM). In contrast, >50% of P. aeruginosa isolates from chronic CF pulmonary infections expressed increased levels of alginate and mucoidy both under iron-limiting and iron-replete conditions (i.e., iron-constitutive phenotype). No single iron regulatory factor (e.g., Fur, PvdS) was associated with this loss of iron-regulated alginate expression and mucoidy in these CF isolates. However, the loss of only pyoverdine production, or its uptake, abrogated the ability of P. aeruginosa to produce a robust biofilm that represents the Psl-type of biofilm. In contrast, we show that mutation of the pyoverdine and pyochelin biosynthesis genes and the pyoverdine receptor (FpvA) lead to iron-constitutive expression of the key alginate biosynthesis gene, algD, and an explicitly mucoid phenotype in both iron-limiting and iron-replete conditions. These data indicate that alginate production and mucoidy, in contrast to other types of biofilms produced by P. aeruginosa, are substantially enhanced under iron limitation. These results also have compelling implications in relation to the use of iron chelators in the treatment of P. aeruginosa CF infections. PMID:24496793

Cosmetics alter biologically-based factors of beauty: evidence from facial contrast.

PubMed

Jones, Alex L; Russell, Richard; Ward, Robert

2015-02-28

The use of cosmetics by women seems to consistently increase their attractiveness. What factors of attractiveness do cosmetics alter to achieve this? Facial contrast is a known cue to sexual dimorphism and youth, and cosmetics exaggerate sexual dimorphisms in facial contrast. Here, we demonstrate that the luminance contrast pattern of the eyes and eyebrows is consistently sexually dimorphic across a large sample of faces, with females possessing lower brow contrasts than males, and greater eye contrast than males. Red-green and yellow-blue color contrasts were not found to differ consistently between the sexes. We also show that women use cosmetics not only to exaggerate sexual dimorphisms of brow and eye contrasts, but also to increase contrasts that decline with age. These findings refine the notion of facial contrast, and demonstrate how cosmetics can increase attractiveness by manipulating factors of beauty associated with facial contrast.

Small-animal CT: Its difference from, and impact on, clinical CT

NASA Astrophysics Data System (ADS)

Ritman, Erik L.

2007-10-01

For whole-body computed tomography (CT) images of small rodents, a voxel resolution of at least 10 -3 mm 3 is needed for scale-equivalence to that currently achieved in clinical CT scanners (˜1 mm 3) in adult humans. These "mini-CT" images generally require minutes rather than seconds to complete a scan. The radiation exposure resulting from these mini-CT scans, while higher than clinical CT scans, is below the level resulting in acute tissue damage. Hence, these scans are useful for performing clinical-type diagnostic and monitoring scans for animal models of disease and their response to treatment. "Micro-CT", with voxel size <10 -5 mm 3, has been useful for imaging isolated, intact organs at an almost cellular level of resolution. Micro-CT has the great advantage over traditional microscopic methods in that it generates detailed three-dimensional images in relatively large, opaque volumes such as an intact rodent heart or kidney. The radiation exposure needed in these scans results in acute tissue damage if used in living animals. Experience with micro-CT is contributing to exploration of new applications for clinical CT imaging by providing insights into different modes of X-ray image formation as follows: Spatial resolution should be sufficient to detect an individual Basic Functional Unit (BFU, the smallest collection of diverse cells, such as hepatic lobule, that behaves like the organ), which requires voxels ˜10 -3 mm 3 in volume, so that the BFUs can be counted. Contrast resolution sufficient to allow quantitation of: New microvascular growth, which manifests as increased tissue contrast due to X-ray contrast agent in those vessels' lumens during passage of injected contrast agent in blood. Impaired endothelial integrity which manifests as increased opacification and delayed washout of contrast from tissues. Discrimination of pathological accumulations of metals such as Fe and Ca, which occur in the arterial wall following hemorrhage or tissue damage. Micro-CT can also be used as a test bed for exploring the utility of several modes of X-ray image formation, such as the use of dual-energy X-ray subtraction, X-ray scatter, phase delay and refraction-based imaging for increasing the contrast amongst soft tissue components. With the recent commercial availability of high speed, multi-slice CT scanners which can be operated in dual-energy mode, some of these micro-CT scanner capabilities and insights are becoming implementable in those CT scanners. As a result, the potential diagnostic spectrum that can be addressed with those scanners is broadened considerably.

Cold acclimation induces distinctive changes in the chromatin state and transcript levels of COR genes in Cannabis sativa varieties with contrasting cold acclimation capacities.

PubMed

Mayer, Boris F; Ali-Benali, Mohamed Ali; Demone, Jordan; Bertrand, Annick; Charron, Jean-Benoit

2015-11-01

Little is known about the capacity of Cannabis sativa to cold-acclimate and develop freezing tolerance. This study investigates the cold acclimation (CA) capacity of nine C. sativa varieties and the underlying genetic and epigenetic responses. The varieties were divided into three groups based on their contrasting CA capacities by comparing the survival of non-acclimated and cold-acclimated plants in whole-plant freeze tests. In response to the CA treatment, all varieties accumulated soluble sugars but only the varieties with superior capacity for CA could maintain higher levels throughout the treatment. In addition, the varieties that acclimated most efficiently accumulated higher transcript levels of cold-regulated (COR) genes and genes involved in de novo DNA methylation while displaying locus- and variety-specific changes in the levels of H3K9ac, H3K27me3 and methylcytosine (MeC) during CA. Furthermore, these hardy C. sativa varieties displayed significant increases in MeC levels at COR gene loci when deacclimated, suggesting a role for locus-specific DNA methylation in deacclimation. This study uncovers the molecular mechanisms underlying CA in C. sativa and reveals higher levels of complexity regarding how genetic, epigenetic and environmental factors intertwine. © 2014 Scandinavian Plant Physiology Society.

A HIF-1alpha-related gene involved in cell protection from hypoxia by suppression of mitochondrial function.

PubMed

Kakinuma, Yoshihiko; Katare, Rajesh G; Arikawa, Mikihiko; Muramoto, Kazuyo; Yamasaki, Fumiyasu; Sato, Takayuki

2008-01-23

Recently, we reported that acetylcholine-induced hypoxia-inducible factor-1alpha protects cardiomyocytes from hypoxia; however, the downstream factors reducing hypoxic stress are unknown. We identified apoptosis inhibitor (AI) gene as being differentially expressed between von Hippel Lindau (VHL) protein-positive cells with high levels of GRP78 expression and VHL-negative cells with lower GRP levels, using cDNA subtraction. AI decreased GRP78 level, suppressed mitochondrial function, reduced oxygen consumption and, ultimately, suppressed hypoxia-induced apoptosis. By contrast, knockdown of the AI gene increased mitochondrial function. Hypoxic cardiomyocytes and ischemic myocardium showed increased AI mRNA expression. These findings suggest that AI is involved in suppressing mitochondrial function, thereby leading to cellular stress eradication and consequently to protection during hypoxia.

A mechanism for deep chromospheric heating during solar flares

NASA Technical Reports Server (NTRS)

Machado, M. E.; Emslie, A. G.; Mauas, P. J.

1986-01-01

The role of the negative hydrogen ion, H(-), in the energy balance of the deep solar chromosphere is reexamined and it is found, in contrast with earlier authors, that H(-) is a source of heating at these levels. The response of this region to an ionizing flux of flare-associated UV radiation (1500 to 1900 A) is then addressed: it is found that the excess ionization of Si to Si(+) increases the local electron number density considerably, since most species are largely neutral at deep chromospheric levels. This in turn increases the electron-hydrogen atom association rate, the H(-) abundance, and the rate of absorption of photospheric radiation by this ion. It is found that the excess absorption by this process may lead to a substantial temperature enhancement at temperature minimum levels during flares.

Urokinase injection-triggered clearance enhancement of a 4-arm PEG-conjugated 64Cu-bombesin analog tetramer: A novel approach for the improvement of PET imaging contrast.

PubMed

Matsumura, Kazushi; Zouda, Maki; Wada, Yasuhiro; Yamashita, Fumiyoshi; Hashida, Mitsuru; Watanabe, Yasuyoshi; Mukai, Hidefumi

2018-05-07

Radiolabeled antibodies, polyethylene glycol-conjugated (PEGylated) peptides, liposomes, and other materials were investigated as positron-emission tomography (PET) probes. These substances accumulate in tumors but often remain too long in circulation. We investigated the combination of intravenous urokinase injection and its substrate linker as a triggered radioisotope clearance enhancement system to improve imaging contrast. To this end, we synthesized a four-arm PEGylated 64 Cu-bombesin analog tetramer with a urokinase substrate linker. In mouse blood, it was almost perfectly cleaved and degraded into smaller radioactive fragments in vitro with urokinase (≥20,000 IU/mL). In mouse blood circulation, ∼50-65% of the probe was rapidly degraded after the urokinase injection and the radioactive fragments were eliminated mainly from the kidney. In contrast, tumor radioactivity levels did not change, and therefore, the tumors were clearly visualized. The tumor/blood ratio, an indicator of imaging contrast, increased 2.5 times, while elimination of the radioisotope from the blood was enhanced. This approach has the potential to improve imaging contrast using various PET probes. It could also shorten the time required to obtain sufficient contrast and decrease patient radiation exposure. Copyright © 2018 Elsevier B.V. All rights reserved.

Optimization of contrast-enhanced spectral mammography depending on clinical indication

PubMed Central

Dromain, Clarisse; Canale, Sandra; Saab-Puong, Sylvie; Carton, Ann-Katherine; Muller, Serge; Fallenberg, Eva Maria

2014-01-01

Abstract. The objective is to optimize low-energy (LE) and high-energy (HE) exposure parameters of contrast-enhanced spectral mammography (CESM) examinations in four different clinical applications for which different levels of average glandular dose (AGD) and ratios between LE and total doses are required. The optimization was performed on a Senographe DS with a SenoBright® upgrade. Simulations were performed to find the optima by maximizing the contrast-to-noise ratio (CNR) on the recombined CESM image using different targeted doses and LE image quality. The linearity between iodine concentration and CNR as well as the minimal detectable iodine concentration was assessed. The image quality of the LE image was assessed on the CDMAM contrast-detail phantom. Experiments confirmed the optima found on simulation. The CNR was higher for each clinical indication than for SenoBright®, including the screening indication for which the total AGD was 22% lower. Minimal iodine concentrations detectable in the case of a 3-mm-diameter round tumor were 12.5% lower than those obtained for the same dose in the clinical routine. LE image quality satisfied EUREF acceptable limits for threshold contrast. This newly optimized set of acquisition parameters allows increased contrast detectability compared to parameters currently used without a significant loss in LE image quality. PMID:26158058

Optimization of contrast-enhanced spectral mammography depending on clinical indication.

PubMed

Dromain, Clarisse; Canale, Sandra; Saab-Puong, Sylvie; Carton, Ann-Katherine; Muller, Serge; Fallenberg, Eva Maria

2014-10-01

The objective is to optimize low-energy (LE) and high-energy (HE) exposure parameters of contrast-enhanced spectral mammography (CESM) examinations in four different clinical applications for which different levels of average glandular dose (AGD) and ratios between LE and total doses are required. The optimization was performed on a Senographe DS with a SenoBright® upgrade. Simulations were performed to find the optima by maximizing the contrast-to-noise ratio (CNR) on the recombined CESM image using different targeted doses and LE image quality. The linearity between iodine concentration and CNR as well as the minimal detectable iodine concentration was assessed. The image quality of the LE image was assessed on the CDMAM contrast-detail phantom. Experiments confirmed the optima found on simulation. The CNR was higher for each clinical indication than for SenoBright®, including the screening indication for which the total AGD was 22% lower. Minimal iodine concentrations detectable in the case of a 3-mm-diameter round tumor were 12.5% lower than those obtained for the same dose in the clinical routine. LE image quality satisfied EUREF acceptable limits for threshold contrast. This newly optimized set of acquisition parameters allows increased contrast detectability compared to parameters currently used without a significant loss in LE image quality.

Biochemical analysis of reactive oxygen species production and antioxidative responses in unripe avocado (Persea americana Mill var Hass) fruits in response to wounding.

PubMed

Castro-Mercado, E; Martinez-Diaz, Y; Roman-Tehandon, N; Garcia-Pineda, E

2009-03-01

We analyzed the production of reactive oxygen species (ROS) and of detoxifying enzymes and enzymes of the ascorbate (ASC) acid cycle in avocado fruit (Pesea Americana Mill cv Hass) in response to wounding. The levels of superoxide anion (O(2-), hydroxyl radicals (OH.) and hydrogen peroxide (H(2)O(2)) increased at 15 min and 2 and 15 h post-wounding. Peroxidase (POD) activity had increased to high levels 24 h after wounding; in contrast, catalase and superoxide dismutase (SOD) levels hat decreased significantly at 24 h post-treatment. Basic POD was the major POD form induced, and the levels of at least three apoplastic POD isozymes -increased following wounding. Using specific inhibitors, we characterized one MnSOD and two CuZnSOD isozymes. CuZnSOD activities decreased notably 12 h after treatment. The activities of dehydroascorbate reductase and glutathione reductase increased dramatically following the wounding treatment, possibly as a means to compensate for the redox changes due to ROS production.

An in vivo, MRI-integrated real-time model of active contrast extravasation in acute intracerebral hemorrhage.

PubMed

Aviv, R I; Huynh, T; Huang, Y; Ramsay, D; Van Slyke, P; Dumont, D; Asmah, P; Alkins, R; Liu, R; Hynynen, K

2014-09-01

The "spot sign" or contrast extravasation is strongly associated with hematoma formation and growth. An animal model of contrast extravasation is important to test existing and novel therapeutic interventions to inform present and future clinical studies. The purpose of this study was to create an animal model of contrast extravasation in acute intracerebral hemorrhage. Twenty-eight hemispheres of Yorkshire male swine were insonated with an MR imaging-guided focused sonography system following lipid microsphere infusion and mean arterial pressure elevation. The rate of contrast leakage was quantified by using dynamic contrast-enhanced MR imaging and was classified as contrast extravasation or postcontrast leakage by using postcontrast T1. Hematoma volume was measured on gradient recalled-echo MR imaging performed 2 hours postprocedure. Following this procedure, sacrificed brain was subjected to histopathologic examination. Power level, burst length, and blood pressure elevation were correlated with leakage rate, hematoma size, and vessel abnormality extent. Median (intracerebral hemorrhage) contrast extravasation leakage was higher than postcontrast leakage (11.3; 6.3-23.2 versus 2.4; 1.1-3.1 mL/min/100 g; P<.001). Increasing burst length, gradient recalled-echo hematoma (ρ=0.54; 95% CI, 0.2-0.8; P=.007), and permeability were correlated (ρ=0.55; 95% CI, 0.1-0.8; P=.02). Median permeability (P=.02), gradient recalled-echo hematoma (P=.02), and dynamic contrast-enhanced volumes (P=.02) were greater at 1000 ms than at 10 ms. Within each burst-length subgroup, incremental contrast leakage was seen with mean arterial pressure elevation (ρ=0.2-0.8). We describe a novel MR imaging-integrated real-time swine intracerebral hemorrhage model of acute hematoma growth and contrast extravasation. © 2014 by American Journal of Neuroradiology.

Attention enhances contrast appearance via increased input baseline of neural responses

PubMed Central

Cutrone, Elizabeth K.; Heeger, David J.; Carrasco, Marisa

2014-01-01

Covert spatial attention increases the perceived contrast of stimuli at attended locations, presumably via enhancement of visual neural responses. However, the relation between perceived contrast and the underlying neural responses has not been characterized. In this study, we systematically varied stimulus contrast, using a two-alternative, forced-choice comparison task to probe the effect of attention on appearance across the contrast range. We modeled performance in the task as a function of underlying neural contrast-response functions. Fitting this model to the observed data revealed that an increased input baseline in the neural responses accounted for the enhancement of apparent contrast with spatial attention. PMID:25549920

Differential expression of genes associated with lipid metabolism in longissimus dorsi of Korean bulls and steers.

PubMed

Bong, Jin Jong; Jeong, Jin Young; Rajasekar, Panchamoorthy; Cho, Young Moo; Kwon, Eung Gi; Kim, Hyeong Cheol; Paek, Bong Hyun; Baik, Myunggi

2012-07-01

The objective of this study was to compare expression of genes associated with lipid deposition and removal between bulls and steers in the longissimus dorsi muscle (LM) tissue of Korean cattle. Castration increased the expression of lipid uptake lipoprotein lipase, fatty acid translocase, and fatty acid transport protein 1 in LM. Castration increased lipogenic gene expression of both acetyl-CoA carboxylase and fatty acid synthase. In contrast, castration downregulated lipolytic gene expression of both adipose triglyceride lipase (ATGL) and monoglyceride lipase. Steers showed higher expression levels of insulin signaling phospho-v-akt murine thymoma viral oncogene homolog 1 than bulls but lower protein levels of nuclear Forkhead box O 1 (FoxO1) than bulls, suggesting that increased insulin signaling following castration decreases nuclear FoxO1 levels, leading to downregulation of ATGL gene expression. These findings suggest that castration contributes to increases in lipid uptake and lipogenesis and a decrease in lipolysis, resulting in improved marbling. Copyright © 2012 Elsevier Ltd. All rights reserved.

Feasibility of spatial frequency-domain imaging for monitoring palpable breast lesions

NASA Astrophysics Data System (ADS)

Robbins, Constance M.; Raghavan, Guruprasad; Antaki, James F.; Kainerstorfer, Jana M.

2017-12-01

In breast cancer diagnosis and therapy monitoring, there is a need for frequent, noninvasive disease progression evaluation. Breast tumors differ from healthy tissue in mechanical stiffness as well as optical properties, which allows optical methods to detect and monitor breast lesions noninvasively. Spatial frequency-domain imaging (SFDI) is a reflectance-based diffuse optical method that can yield two-dimensional images of absolute optical properties of tissue with an inexpensive and portable system, although depth penetration is limited. Since the absorption coefficient of breast tissue is relatively low and the tissue is quite flexible, there is an opportunity for compression of tissue to bring stiff, palpable breast lesions within the detection range of SFDI. Sixteen breast tissue-mimicking phantoms were fabricated containing stiffer, more highly absorbing tumor-mimicking inclusions of varying absorption contrast and depth. These phantoms were imaged with an SFDI system at five levels of compression. An increase in absorption contrast was observed with compression, and reliable detection of each inclusion was achieved when compression was sufficient to bring the inclusion center within ˜12 mm of the phantom surface. At highest compression level, contrasts achieved with this system were comparable to those measured with single source-detector near-infrared spectroscopy.

An Increase in Postural Load Facilitates an Anterior Shift of Processing Resources to Frontal Executive Function in a Postural-Suprapostural Task

PubMed Central

Huang, Cheng-Ya; Chang, Gwo-Ching; Tsai, Yi-Ying; Hwang, Ing-Shiou

2016-01-01

Increase in postural-demand resources does not necessarily degrade a concurrent motor task, according to the adaptive resource-sharing hypothesis of postural-suprapostural dual-tasking. This study investigated how brain networks are organized to optimize a suprapostural motor task when the postural load increases and shifts postural control into a less automatic process. Fourteen volunteers executed a designated force-matching task from a level surface (a relative automatic process in posture) and from a stabilometer board while maintaining balance at a target angle (a relatively controlled process in posture). Task performance of the postural and suprapostural tasks, synchronization likelihood (SL) of scalp EEG, and graph-theoretical metrics were assessed. Behavioral results showed that the accuracy and reaction time of force-matching from a stabilometer board were not affected, despite a significant increase in postural sway. However, force-matching in the stabilometer condition showed greater local and global efficiencies of the brain networks than force-matching in the level-surface condition. Force-matching from a stabilometer board was also associated with greater frontal cluster coefficients, greater mean SL of the frontal and sensorimotor areas, and smaller mean SL of the parietal-occipital cortex than force-matching from a level surface. The contrast of supra-threshold links in the upper alpha and beta bands between the two stance conditions validated load-induced facilitation of inter-regional connections between the frontal and sensorimotor areas, but that contrast also indicated connection suppression between the right frontal-temporal and the parietal-occipital areas for the stabilometer stance condition. In conclusion, an increase in stance difficulty alters the neurocognitive processes in executing a postural-suprapostural task. Suprapostural performance is not degraded by increase in postural load, due to (1) increased effectiveness of information transfer, (2) an anterior shift of processing resources toward frontal executive function, and (3) cortical dissociation of control hubs in the parietal-occipital cortex for neural economy. PMID:27594830

Application of a Noise Adaptive Contrast Sensitivity Function to Image Data Compression

NASA Astrophysics Data System (ADS)

Daly, Scott J.

1989-08-01

The visual contrast sensitivity function (CSF) has found increasing use in image compression as new algorithms optimize the display-observer interface in order to reduce the bit rate and increase the perceived image quality. In most compression algorithms, increasing the quantization intervals reduces the bit rate at the expense of introducing more quantization error, a potential image quality degradation. The CSF can be used to distribute this error as a function of spatial frequency such that it is undetectable by the human observer. Thus, instead of being mathematically lossless, the compression algorithm can be designed to be visually lossless, with the advantage of a significantly reduced bit rate. However, the CSF is strongly affected by image noise, changing in both shape and peak sensitivity. This work describes a model of the CSF that includes these changes as a function of image noise level by using the concepts of internal visual noise, and tests this model in the context of image compression with an observer study.

The influence of acute resistance exercise on cyclooxygenase-1 and -2 activity and protein levels in human skeletal muscle.

PubMed

Carroll, Chad C; O'Connor, Devin T; Steinmeyer, Robert; Del Mundo, Jonathon D; McMullan, David R; Whitt, Jamie A; Ramos, Jahir E; Gonzales, Rayna J

2013-07-01

This study evaluated the activity and content of cyclooxygenase (COX)-1 and -2 in response to acute resistance exercise (RE) in human skeletal muscle. Previous work suggests that COX-1, but not COX-2, is the primary COX isoform elevated with resistance exercise in human skeletal muscle. COX activity, however, has not been assessed after resistance exercise in humans. It was hypothesized that RE would increase COX-1 but not COX-2 activity. Muscle biopsies were taken from the vastus lateralis of nine young men (25 ± 1 yr) at baseline (preexercise), 4, and 24 h after a single bout of knee extensor RE (three sets of 10 repetitions at 70% of maximum). Tissue lysate was assayed for COX-1 and COX-2 activity. COX-1 and COX-2 protein levels were measured via Western blot analysis. COX-1 activity increased at 4 h (P < 0.05) compared with preexercise, but returned to baseline at 24 h (PRE: 60 ± 10, 4 h: 106 ± 22, 24 h: 72 ± 8 nmol PGH2·g total protein(-1)·min(-1)). COX-2 activity was elevated at 4 and 24 h after RE (P < 0.05, PRE: 51 ± 7, 4 h: 100 ± 19, 24 h: 98 ± 14 nmol PGH2·g total protein(-1)·min(-1)). The protein level of COX-1 was not altered (P > 0.05) with acute RE. In contrast, COX-2 protein levels were nearly 3-fold greater (P > 0.05) at 4 h and 5-fold greater (P = 0.06) at 24 h, compared with preexercise. In conclusion, COX-1 activity increases transiently with exercise independent of COX-1 protein levels. In contrast, both COX-2 activity and protein levels were elevated with exercise, and this elevation persisted to at least 24 h after RE.

The diagnostic value of CRP, IL-8, PCT, and sTREM-1 in the detection of bacterial infections in pediatric oncology patients with febrile neutropenia.

PubMed

Miedema, Karin G E; de Bont, Eveline S J M; Elferink, Rob F M Oude; van Vliet, Michel J; Nijhuis, Claudi S M Oude; Kamps, Willem A; Tissing, Wim J E

2011-10-01

In this study, we evaluated C-reactive protein (CRP), interleukin (IL)-8, procalcitonin (PCT), and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) as predictors for bacterial infection in febrile neutropenia, plus their usefulness in febrile neutropenia during chemotherapy-induced gastrointestinal mucositis. Plasma was obtained from pediatric oncology patients at presentation with febrile neutropenia (n = 43) and 24-48 h later (n = 17). The patients were classified as having or not having a bacterial infection. Plasma was also obtained of patients in the absence and in the presence of mucositis (n = 26). At presentation with febrile neutropenia, median IL-8 and PCT levels were significantly increased in patients with a bacterial infection, in contrast to CRP and sTREM-1. IL-8 was the most sensitive marker for the early detection of bacterial infection, in combination with clinical parameters or PCT the sensitivity reached 100%. After 24-48 h, only PCT was significantly elevated during bacterial infection. IL-8 levels were significantly increased during mucositis. Mucositis did not cause considerable changes in PCT levels. IL-8 is the most useful marker for the early detection of bacterial infections, compared with CRP, PCT, and sTREM-1. IL-8 in combination with clinical parameters or PCT might be even more useful. Gastrointestinal mucositis alone does not affect PCT levels, in contrast to IL-8 levels, and therefore, PCT might be more useful for the detection of bacterial infections during mucositis than IL-8.

Chronic nicotine treatment leads to induction of tyrosine hydroxylase in locus ceruleus neurons: the role of transcriptional activation.

PubMed

Sun, Baoyong; Chen, Xiqun; Xu, Lu; Sterling, Carol; Tank, A William

2004-10-01

Chronic nicotine treatment (two daily subcutaneous injections administered approximately 12 h apart for 14 days) is associated with long-term inductions of tyrosine hydroxylase (TH) protein and TH mRNA in locus ceruleus (LC) neurons. These increases persist for at least 3 days after the final nicotine injection in LC cell bodies and for at least 7 to 10 days in LC nerve terminal regions. We tested whether this long-term response is due to sustained stimulation of TH gene transcription rate. A semiquantitative reverse transcription-polymerase chain reaction assay was developed to assess changes in the levels of TH RNA primary transcripts; these changes are an indirect measurement of changes in TH gene transcription rate. TH RNA primary transcript levels increase rapidly in the LC after a single nicotine administration and return to basal levels by 24 h. A similar rapid and transient induction of LC TH RNA primary transcripts occurs after chronic nicotine administration. In contrast, TH RNA primary transcript levels remain elevated for a sustained period of time (at least 1 day) in the adrenal medulla after chronic nicotine administration. Similar rapid, but transient changes in LC TH RNA primary transcript levels are observed after repeated immobilization stress. These results suggest that TH gene transcription rate in the LC is stimulated rapidly after each nicotine injection; however, in contrast to the adrenal medulla, there is no sustained transcriptional response elicited by chronic nicotine treatment or repeated immobilization stress in the LC, suggesting that post-transcriptional mechanisms may also play a role in these long-term responses.

Neural bases of rhythmic entrainment in humans: critical transformation between cortical and lower-level representations of auditory rhythm.

PubMed

Nozaradan, Sylvie; Schönwiesner, Marc; Keller, Peter E; Lenc, Tomas; Lehmann, Alexandre

2018-02-01

The spontaneous ability to entrain to meter periodicities is central to music perception and production across cultures. There is increasing evidence that this ability involves selective neural responses to meter-related frequencies. This phenomenon has been observed in the human auditory cortex, yet it could be the product of evolutionarily older lower-level properties of brainstem auditory neurons, as suggested by recent recordings from rodent midbrain. We addressed this question by taking advantage of a new method to simultaneously record human EEG activity originating from cortical and lower-level sources, in the form of slow (< 20 Hz) and fast (> 150 Hz) responses to auditory rhythms. Cortical responses showed increased amplitudes at meter-related frequencies compared to meter-unrelated frequencies, regardless of the prominence of the meter-related frequencies in the modulation spectrum of the rhythmic inputs. In contrast, frequency-following responses showed increased amplitudes at meter-related frequencies only in rhythms with prominent meter-related frequencies in the input but not for a more complex rhythm requiring more endogenous generation of the meter. This interaction with rhythm complexity suggests that the selective enhancement of meter-related frequencies does not fully rely on subcortical auditory properties, but is critically shaped at the cortical level, possibly through functional connections between the auditory cortex and other, movement-related, brain structures. This process of temporal selection would thus enable endogenous and motor entrainment to emerge with substantial flexibility and invariance with respect to the rhythmic input in humans in contrast with non-human animals. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Modulation of apelin and APJ receptor in normal and preeclampsia-complicated placentas.

PubMed

Cobellis, L; De Falco, M; Mastrogiacomo, A; Giraldi, D; Dattilo, D; Scaffa, C; Colacurci, N; De Luca, A

2007-01-01

Apelin is an endogenous ligand of the human orphan receptor APJ. This peptide is produced through processing from the C-terminal portion in the pre-pro-protein consisting of 77 amino acid residues and exists in multiple molecular forms. Although the main physiological functions of apelin have not yet been clarified, it is known that apelin is involved in the regulation of blood pressure, blood flow and central control of body fluid homeostasis in different organs. Since human placenta is a tissue where vasculogenesis, blood pressure and flow are dramatically important to allow a normal embryonic and fetal growth and development, the aim of the present study was to investigate the immunohistochemical distribution of apelin and APJ in normal placentas throughout pregnancy and in preeclampsia-complicated placentas. Specifically, we observed that in normal placentas the expression levels of apelin decreased from the first to the third trimester of gestation in both cytotrophoblast and syncytiotrophoblast cells and in the stroma of placental villi, in contrast with increased expression levels of APJ in the cytoplasm of cytotrophoblast cells and in the cytoplasm of endothelial cells of normal placenta samples. In contrast, in preeclampsia-complicated pregnancies, we observed a very strong increase of expression levels of both apelin and APJ receptor in all the placental compartments, cytotrophoblast, syncytiotrophoblast and stroma with a particular increase in endothelial cells inside preeclamptic placental villi. Our data seem to indicate an important role of apelin and APJ in the regulation of fetal development through a correct regulation of human placenta formation during pregnancy. Moreover, the strong expression levels of apelin and APJ in preeclamptic placentas, suggest their possible involvement in the onset of this pathology.

Salivary alpha-amylase and cortisol responsiveness following electrical stimulation stress in major depressive disorder patients.

PubMed

Tanaka, Yoshihiro; Ishitobi, Yoshinobu; Maruyama, Yoshihiro; Kawano, Aimi; Ando, Tomoko; Okamoto, Shizuko; Kanehisa, Masayuki; Higuma, Haruka; Ninomiya, Taiga; Tsuru, Jusen; Hanada, Hiroaki; Kodama, Kensuke; Isogawa, Koichi; Akiyoshi, Jotaro

2012-03-30

Major depressive disorder (MDD) is often associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis by chronic stress. In comparison, psychosocial stress-induced activation of salivary α-amylase (sAA) functions as a marker of sympathoadrenal medullary system (SAM) activity. However, in contrast to salivary cortisol, sAA has been less extensively studied in MDD patients. The present study measured sAA and salivary cortisol levels in patients with MDD. The authors determined Profile of Mood State (POMS) and State-Trait anxiety Inventory (STAI) scores, Heart Rate Variability (HRV), and sAA and salivary cortisol levels in 88 patients with MDD and 41 healthy volunteers following the application of electrical stimulation stress. Patients with major depressive disorder were 8 points or more on Hamilton Depression Scale (HAM-D) scores. Tension-Anxiety, Depression-Dejection, Anger-Hostility, Fatigue, and Confusion scores in patients with major depressive disorder were significantly increased compared to healthy controls. In contrast, Vigor scores in patients with MDD were significantly decreased compared with healthy controls. There was no difference in heart rate variability measures between MDD patients and healthy controls. The threshold of electrical stimulation applied in MDD patients was lower than that in healthy controls. SAA levels in female MDD patients were significantly elevated relative to controls both before and after electrical stimulation. Finally, there were no differences in salivary cortisol levels between major depressive patients and controls. In the present study only three time points were explored. Furthermore, the increased secretion of sAA before and after stimulation could allude to an increased responsiveness of novel and uncontrollable situations in patients with MDD. These preliminary results suggest that sAA might be a useful biological marker of MDD. Copyright © 2011 Elsevier Inc. All rights reserved.

Shear-driven dynamic clusters in a colloidal glass

NASA Astrophysics Data System (ADS)

Eisenmann, Christoph; Kim, Chanjoong; Mattsson, Johan; Weitz, David

2007-03-01

We investigate the effect of shear applied to a colloidal glass on a microscopic level using a shear device that can be mounted on top of a confocal microscope. We find that the glass yields at a critical strain of about 10%, independently of the shear rate. Surprisingly, the yielding is accompanied by an increase of cooperative particle movements and a formation of dynamic clusters which is in contrast to the normal glass transition where one typically finds heterogeneity increasing whilst moving towards the glass transition.

High energy x-ray phase contrast CT using glancing-angle grating interferometers

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

Sarapata, A., E-mail: adrian.sarapata@tum.de; Stayman, J. W.; Siewerdsen, J. H.

Purpose: The authors present initial progress toward a clinically compatible x-ray phase contrast CT system, using glancing-angle x-ray grating interferometry to provide high contrast soft tissue images at estimated by computer simulation dose levels comparable to conventional absorption based CT. Methods: DPC-CT scans of a joint phantom and of soft tissues were performed in order to answer several important questions from a clinical setup point of view. A comparison between high and low fringe visibility systems is presented. The standard phase stepping method was compared with sliding window interlaced scanning. Using estimated dose values obtained with a Monte-Carlo code themore » authors studied the dependence of the phase image contrast on exposure time and dose. Results: Using a glancing angle interferometer at high x-ray energy (∼45 keV mean value) in combination with a conventional x-ray tube the authors achieved fringe visibility values of nearly 50%, never reported before. High fringe visibility is shown to be an indispensable parameter for a potential clinical scanner. Sliding window interlaced scanning proved to have higher SNRs and CNRs in a region of interest and to also be a crucial part of a low dose CT system. DPC-CT images of a soft tissue phantom at exposures in the range typical for absorption based CT of musculoskeletal extremities were obtained. Assuming a human knee as the CT target, good soft tissue phase contrast could be obtained at an estimated absorbed dose level around 8 mGy, similar to conventional CT. Conclusions: DPC-CT with glancing-angle interferometers provides improved soft tissue contrast over absorption CT even at clinically compatible dose levels (estimated by a Monte-Carlo computer simulation). Further steps in image processing, data reconstruction, and spectral matching could make the technique fully clinically compatible. Nevertheless, due to its increased scan time and complexity the technique should be thought of not as replacing, but as complimentary to conventional CT, to be used in specific applications.« less

Hormonal regulation of serum Lp (a) levels. Opposite effects after estrogen treatment and orchidectomy in males with prostatic carcinoma.

PubMed Central

Henriksson, P; Angelin, B; Berglund, L

1992-01-01

Serum concentrations of lipoprotein (a) [Lp (a)] were determined in two groups of elderly males suffering from prostatic carcinoma, who were randomized to treatment with estrogen (n = 15) or orchidectomy (n = 16). Estrogen was given as oral ethinylestradiol, 150 micrograms daily, combined with intramuscular polyestradiol phosphate, 80 mg/mo. The baseline levels were similar in both groups, but 6 mo after initiation of therapy, serum Lp (a) levels were decreased approximately 50% in the estrogen-treated group (P less than 0.001) in contrast to a 20% increase (P less than 0.01) in the orchidectomized group. Concomitantly, LDL cholesterol decreased by 30% and HDL cholesterol increased by almost 60% in the estrogen-treated patients. There was no relationship between the change in LDL cholesterol and Lp (a) reduction. In conclusion, Lp (a) levels in males were found to drastically decrease upon estrogen treatment and to increase after orchidectomy, suggesting that sex hormones, and particularly estrogens, exert a regulatory role on the serum Lp (a) level in man. Images PMID:1532586

Effects of exercise training on glucose control, lipid metabolism, and insulin sensitivity in hypertriglyceridemia and non-insulin dependent diabetes mellitus.

PubMed

Lampman, R M; Schteingart, D E

1991-06-01

Exercise training has potential benefits for patients with hyperlipidemia and/or non-insulin dependent diabetes mellitus. In nondiabetic, nonobese subjects with hypertriglyceridemia, exercise training alone increased insulin sensitivity, improved glucose tolerance, and lowered serum triglyceride and cholesterol levels. These improvements did not occur when exercise training alone was given to similar patients with impaired glucose tolerance. In severely obese (X = 125 kg) subjects without diabetes melitus, a 600 calorie diet alone decreased glucose and insulin concentrations and improved glucose tolerance but did not increase insulin sensitivity. The addition of exercise training improved insulin sensitivity. Obese, non-insulin dependent diabetes mellitus subjects on sulfonylurea therapy alone increased insulin levels but failed to improve insulin sensitivity or glucose levels. In contrast, the addition of exercise training to this medication resulted in improved insulin sensitivity and lowered glucose levels. We conclude that exercise training has major effects on lowering triglyceride levels in hyperlipidemic subjects and can potentiate the effect of diet or drug therapy on glucose metabolism in patients with non-insulin dependent diabetes mellitus.

Non-invasive imaging using reporter genes altering cellular water permeability

NASA Astrophysics Data System (ADS)

Mukherjee, Arnab; Wu, Di; Davis, Hunter C.; Shapiro, Mikhail G.

2016-12-01

Non-invasive imaging of gene expression in live, optically opaque animals is important for multiple applications, including monitoring of genetic circuits and tracking of cell-based therapeutics. Magnetic resonance imaging (MRI) could enable such monitoring with high spatiotemporal resolution. However, existing MRI reporter genes based on metalloproteins or chemical exchange probes are limited by their reliance on metals or relatively low sensitivity. Here we introduce a new class of MRI reporters based on the human water channel aquaporin 1. We show that aquaporin overexpression produces contrast in diffusion-weighted MRI by increasing tissue water diffusivity without affecting viability. Low aquaporin levels or mixed populations comprising as few as 10% aquaporin-expressing cells are sufficient to produce MRI contrast. We characterize this new contrast mechanism through experiments and simulations, and demonstrate its utility in vivo by imaging gene expression in tumours. Our results establish an alternative class of sensitive, metal-free reporter genes for non-invasive imaging.

Changes caused by haloperidol are blocked by music in Wistar rat.

PubMed

Tasset, Inmaculada; Quero, Ismael; García-Mayórgaz, Ángel D; del Río, Manuel Causse; Túnez, Isaac; Montilla, Pedro

2012-06-01

This study sought to evaluate the effect of classical music, using Mozart's sonata for two pianos (K. 448), on changes in dopamine (DA) levels in the striatal nucleus (SN), prefrontal cortex (PFC) and mesencephalon, and on prolactin (PRL) and corticosterone secretion in adult male Wistar rats. Rats were divided into four groups: (1) control, (2) haloperidol treatment (single dose of 2 mg/kg s.c.), (3) music (two 2-h sessions per day) and (4) haloperidol plus music. Rats were sacrificed 2 h after haloperidol injection. Music prompted a fall in plasma PRL and corticosterone levels in healthy rats (P < 0.05) and prevented the increase in levels triggered by haloperidol (P < 0.001). Moreover, exposure to music was associated with a significant increase in DA levels in all groups, with the increase being particularly marked in PFC and SN (P < 0.001). Haloperidol is a recognised D2 receptor antagonist, and these findings suggest that music, by contrast, enhances DA activity and turnover in the brain. The results obtained here bear out reports that music triggers a reduction in systolic pressure and an increase in mesencephalon dopamine levels in human and rats treated with ecstasy, through a calmodulin-dependent system.

Explaining levels of within-group wage inequality in U.S. labor markets.

PubMed

McCall, L

2000-11-01

Most research on earnings inequality has focused on the growing gap between workers of different races and at different education, age, and income levels, but a large portion of the increasing inequality has actually occurred within these groups. This article focuses on the extent and sources of "within-group" wage inequality in more than 500 labor markets in the United States in 1990. In addition to documenting that within-group wage inequality across regions varies more widely today than over the past several decades, the analysis reveals that two frequently cited explanations of rising wage inequality over time have little impact on within-group wage inequality when measured at the local labor market level: (1) industrial shifts and (2) increased technology and trade. By contrast, flexible and insecure employment conditions (e.g., unemployment, contingent work, and immigration) are associated strongly with high local levels of within-group wage inequality, especially among women.

Influence of HLA-C Expression Level on HIV Control

PubMed Central

Apps, Richard; Qi, Ying; Carlson, Jonathan M.; Chen, Haoyan; Gao, Xiaojiang; Thomas, Rasmi; Yuki, Yuko; Del Prete, Greg Q.; Goulder, Philip; Brumme, Zabrina L.; Brumme, Chanson J.; John, Mina; Mallal, Simon; Nelson, George; Bosch, Ronald; Heckerman, David; Stein, Judy L.; Soderberg, Kelly A.; Moody, M. Anthony; Denny, Thomas N.; Zeng, Xue; Fang, Jingyuan; Moffett, Ashley; Lifson, Jeffrey D.; Goedert, James J.; Buchbinder, Susan; Kirk, Gregory D.; Fellay, Jacques; McLaren, Paul; Deeks, Steven G.; Pereyra, Florencia; Walker, Bruce; Michael, Nelson L.; Weintrob, Amy; Wolinsky, Steven; Liao, Wilson; Carrington, Mary

2013-01-01

A variant upstream of human leukocyte antigen C (HLA-C) shows the most significant genome-wide effect on HIV control in European Americans and is also associated with the level of HLA-C expression. We characterized the differential cell surface expression levels of all common HLA-C allotypes and tested directly for effects of HLA-C expression on outcomes of HIV infection in 5243 individuals. Increasing HLA-C expression was associated with protection against multiple outcomes independently of individual HLA allelic effects in both African and European Americans, regardless of their distinct HLA-C frequencies and linkage relationships with HLA-B and HLA-A. Higher HLA-C expression was correlated with increased likelihood of cytotoxic T lymphocyte responses and frequency of viral escape mutation. In contrast, high HLA-C expression had a deleterious effect in Crohn’s disease, suggesting a broader influence of HLA expression levels in human disease. PMID:23559252

Urinary renin, but not angiotensinogen or aldosterone, reflects the renal renin-angiotensin-aldosterone system activity and the efficacy of renin-angiotensin-aldosterone system blockade in the kidney.

PubMed

van den Heuvel, Mieke; Batenburg, Wendy W; Jainandunsing, Sjaam; Garrelds, Ingrid M; van Gool, Jeanette M G; Feelders, Richard A; van den Meiracker, Anton H; Danser, A H Jan

2011-11-01

To study which renin-angiotensin-aldosterone system (RAAS) component best reflects renal RAAS activity. We measured urinary and plasma renin, prorenin, angiotensinogen, aldosterone, albumin and creatinine in 101 diabetic and nondiabetic patients with or without hypertension. Plasma prorenin was elevated in diabetic patients. Urinary prorenin was undetectable. Urinary albumin and renin were higher in diabetic patients. Men had higher plasma renin/prorenin levels, and lower plasma angiotensinogen levels than women. Plasma creatinine and albumin were also higher in men. Urinary RAAS components showed no sexual dimorphism, whereas urinary creatinine and albumin were higher in men. Angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers increased plasma renin and decreased plasma angiotensinogen, without altering plasma aldosterone. In contrast, in urine, these drugs decreased renin and aldosterone without affecting angiotensinogen. When analyzing all patients together, urinary angiotensinogen excretion closely mimicked that of albumin, whereas urinary angiotensinogen and albumin levels both were 0.05% or less of their concomitant plasma levels. This may reflect the identical glomerular filtration and tubular handling of both proteins, which have a comparable molecular weight. In contrast, urinary renin excretion did not correlate with urinary albumin excretion, and the urinary/plasma concentration ratio of renin was more than 200 times the ratio of albumin, despite its comparable molecular weight. Urinary aldosterone excretion closely followed urinary creatinine excretion. The increased urinary renin levels in diabetes and the decreased urinary renin levels following RAAS blockade, occurring independently of changes in plasma renin, reflect the activated renal RAAS in diabetes and the success of RAAS blockade in the kidney, respectively. Urinary renin, therefore, more closely reflects renal RAAS activity than urinary angiotensinogen or aldosterone.

Autonomous rock detection on mars through region contrast

NASA Astrophysics Data System (ADS)

Xiao, Xueming; Cui, Hutao; Yao, Meibao; Tian, Yang

2017-08-01

In this paper, we present a new autonomous rock detection approach through region contrast. Unlike current state-of-art pixel-level rock segmenting methods, new method deals with this issue in region level, which will significantly reduce the computational cost. Image is firstly splitted into homogeneous regions based on intensity information and spatial layout. Considering the high-water memory constraints of onboard flight processor, only low-level features, average intensity and variation of superpixel, are measured. Region contrast is derived as the integration of intensity contrast and smoothness measurement. Rocks are then segmented from the resulting contrast map by an adaptive threshold. Since the merely intensity-based method may cause false detection in background areas with different illuminations from surroundings, a more reliable method is further proposed by introducing spatial factor and background similarity to the region contrast. Spatial factor demonstrates the locality of contrast, while background similarity calculates the probability of each subregion belonging to background. Our method is efficient in dealing with large images and only few parameters are needed. Preliminary experimental results show that our algorithm outperforms edge-based methods in various grayscale rover images.

High fat diet feeding results in gender specific steatohepatitis and inflammasome activation.

PubMed

Ganz, Michal; Csak, Timea; Szabo, Gyongyi

2014-07-14

To develop an animal model that encompasses the different facets of non-alcoholic steatohepatitis (NASH), which has been a challenge. In this study, we used a high fat diet (HFD) feeding supplemented with fructose and sucrose in the water mimicking the high-fructose corn syrup that is abundant in the diet in the United States. We used C57Bl/6 wild-type mice for short and long-term feedings of 6 and 16 wk respectively, and evaluated the extent of liver damage, steatosis, and inflammasome activation. Our methods included histopathological analysis to assess liver damage and steatosis, which involved H and E and oil-red-o staining; biochemical studies to look at ALT and triglyceride levels; RNA analysis using quantitative polymerase chain reaction; and cytokine analysis, which included the enzyme-linked immunosorbent assay method to look at interleukin (IL)-1β and tumor necrosis factor-α (TNFα) levels. Furthermore, at each length of feeding we also looked at insulin resistance and glucose tolerance using insulin tolerance tests (ITT) and glucose tolerance tests. There was no insulin resistance, steatosis, or inflammasome activation at 6 wk. In contrast, at 16 wk we found significant insulin resistance demonstrated by impaired glucose and ITT in male, but not female mice. In males, elevated alanine aminotransferase and triglyceride levels, indicated liver damage and steatosis, respectively. Increased liver TNFα and monocyte chemoattractant protein-1 mRNA and protein, correlated with steatohepatitis. The inflammasome components, adaptor molecule, Aim2, and NOD-like receptor 4, increased at the mRNA level, and functional inflammasome activation was indicated by increased caspase-1 activity and IL-1β protein levels in male mice fed a long-term HFD. Male mice on HFD had increased α-smooth muscle actin and pro-collagen-1 mRNA indicating evolving fibrosis. In contrast, female mice displayed only elevated triglyceride levels, steatosis, and no fibrosis. Our data indicate gender differences in NASH. Male mice fed a long-term HFD display steatohepatitis and inflammasome activation, whereas female mice have steatosis without inflammation.

Separate But Equal? A Levels and GNVQs. Further Education Series.

ERIC Educational Resources Information Center

Edwards, Tony; Fitz-Gibbon, Carol Taylor; Hardman, Frank; Haywood, Roy; Meagher, Nick

This book contrasts British programs for vocationally and academically minded students and looks at differences and similarities in practice in General National Vocational Qualifications (GNVQs) and Advanced level (A level) courses. "Contrasts in Learning?" (Tony Edwards) provides background. "Educating Leaders and Training…

FDG-Avid Portal Vein Tumor Thrombosis from Hepatocellular Carcinoma in Contrast-Enhanced FDG PET/CT

PubMed Central

Nguyen, Xuan Canh; Nguyen, Dinh Song Huy; Ngo, Van Tan; Maurea, Simone

2015-01-01

Objective(s): In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan. Methods: In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis. Results: Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%). PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001). FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001). PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6%) had no extrahepatic metastasis, 3 cases (33.3%) had metastasis of regional lymph nodes, and 1 case (11.1%) presented with distant metastasis. The median estimated survival time of patients was 5 months. Conclusion: The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are findings of FDG-avid PVTT from HCC in contrast-enhanced FDG PET/CT. PMID:27408876

Relationship between contrast sensitivity test and disease severity in multiple sclerosis patients.

PubMed

Soler García, A; González Gómez, A; Figueroa-Ortiz, L C; García-Ben, A; García-Campos, J

2014-09-01

To assess the importance of the Pelli-Robson contrast sensitivity test in multiple sclerosis patients according to the Expanded Disability Status Scale (EDSS). A total of 62 patients with multiple sclerosis were included in a retrospective study. Patients were enrolled from the Neurology Department to Neuroophthalmology at Virgen de la Victoria Hospital. Patients were classified into 3 groups according to EDSS: group A) lower than 1.5, group B) between 1.5 and 3.5 and group C) greater than 3.5. Visual acuity and monocular and binocular contrast sensitivity were performed with Snellen and Pelli-Robson tests respectively. Twelve disease-free control participants were also recruited. Correlations between parameter changes were analyzed. The mean duration of the disease was 81.54±35.32 months. Monocular and binocular Pelli-Robson mean values in the control group were 1.82±0.10 and 1.93±0.43 respectively, and 1.61±0.29 and 1.83±0.19 in multiple sclerosis patients. There were statistically significant differences in the monocular analysis for a level of significance P<.05. Mean monocular and binocular Pelli-Robson values in relation to gravity level were, in group A: 1.66±0.24 and 1.90±0.98, group B: 1.64±0.21 and 1.82±0.16, and group C: 1.47±0.45 and 1.73±0.32 respectively. Group differences were statistically significant in both tests: P=.05 and P=.027. Monocular and binocular contrast discrimination analyzed using the Pelli-Robson test was found to be significantly lower when the severity level, according EDSS, increases in multiple sclerosis patients. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Contrasting models of driver behaviour in emergencies using retrospective verbalisations and network analysis.

PubMed

Banks, Victoria A; Stanton, Neville A

2015-01-01

Automated assistance in driving emergencies aims to improve the safety of our roads by avoiding or mitigating the effects of accidents. However, the behavioural implications of such systems remain unknown. This paper introduces the driver decision-making in emergencies (DDMiEs) framework to investigate how the level and type of automation may affect driver decision-making and subsequent responses to critical braking events using network analysis to interrogate retrospective verbalisations. Four DDMiE models were constructed to represent different levels of automation within the driving task and its effects on driver decision-making. Findings suggest that whilst automation does not alter the decision-making pathway (e.g. the processes between hazard detection and response remain similar), it does appear to significantly weaken the links between information-processing nodes. This reflects an unintended yet emergent property within the task network that could mean that we may not be improving safety in the way we expect. This paper contrasts models of driver decision-making in emergencies at varying levels of automation using the Southampton University Driving Simulator. Network analysis of retrospective verbalisations indicates that increasing the level of automation in driving emergencies weakens the link between information-processing nodes essential for effective decision-making.

Contrasting SWAT predictions of watershed-level streamflow and nutrient loss resulting from static versus dynamic atmospheric CO2 inputs

USDA-ARS?s Scientific Manuscript database

Past climate observations have indicated a rapid increase in global atmospheric CO2 concentration during late 20th century (13 ppm/decade), and models project further rise throughout the 21st century (24 ppm/decade and 69 ppm/decade in the best and worst case scenario, respectively). We modified SWA...

Understanding the Increase in Parents' Involvement in Organized Youth Sports

ERIC Educational Resources Information Center

Stefansen, Kari; Smette, Ingrid; Strandbu, Åse

2018-01-01

As part of an ethnographic study on young people and learning (the knowledge in motion across contexts of learning project, set in Norway), we interviewed a diverse sample of parents of young teenagers, many of whom were active in organized sports. The parents described their level of involvement in sport in a way that contrasted sharply to our…

Retention and Graduation Rates: Insights from an Extended Longitudinal View

ERIC Educational Resources Information Center

Boden, Gary T.

2012-01-01

This study examines a 118-year continuous record of retention and graduation rates at a public university for long-term trends not observable in shorter studies. While the first year retention rates stayed level over much of this period, second year rates increased steadily by 1.2% per decade. In contrast, graduation rates at 4 years compared to 6…

Low salinity and high-level UV-B radiation reduce single-cell activity in antarctic sea ice bacteria.

PubMed

Martin, Andrew; Hall, Julie; Ryan, Ken

2009-12-01

Experiments simulating the sea ice cycle were conducted by exposing microbes from Antarctic fast ice to saline and irradiance regimens associated with the freeze-thaw process. In contrast to hypersaline conditions (ice formation), the simulated release of bacteria into hyposaline seawater combined with rapid exposure to increased UV-B radiation significantly reduced metabolic activity.

Effects of short-term hypothermal and contrast exposure on immunophysiological parameters of laboratory animals.

PubMed

Kalenova, L F; Fisher, T A; Suhovey, J G; Besedin, I M

2009-05-01

Experiments on inbred animals showed that short-term exposure in cold water significantly modified structural and functional parameters of the immune system at different levels of its organization, from bone marrow hemopoiesis to effector stage of the immune response to antigen. The thermal factor caused changes in nonspecific and specific mechanisms of the immune system. Hypothermal exposure (7-9 degrees C, 5 sec) increased the thymic index and bone marrow lymphocyte count, reduced absorption capacity and stimulated metabolic activity of phagocytes, stimulated cell-mediated and suppressed humoral immunity. Contrast exposure in cold and hot water (7-9 degrees C, 5 sec/40-42 degrees C, 30 sec) increased monocyte count in bone marrow and reduced it in the their peripheral blood, reduced metabolic activity of phagocytes, stimulated cell-mediated and suppressed humoral immunity. These data demonstrate physiological mechanisms of interactions between the thermoregulatory and immune systems.

Growth habit and leaf economics determine gas exchange responses to high elevation in an evergreen tree, a deciduous shrub and a herbaceous annual

PubMed Central

Shi, Zuomin; Haworth, Matthew; Feng, Qiuhong; Cheng, Ruimei; Centritto, Mauro

2015-01-01

Plant growth at high elevations necessitates physiological and morphological plasticity to enable photosynthesis (A) under conditions of reduced temperature, increased radiation and the lower partial pressure of atmospheric gases, in particular carbon dioxide (pCO2). Previous studies have observed a wide range of responses to elevation in plant species depending on their adaptation to temperature, elevational range and growth habit. Here, we investigated the effect of an increase in elevation from 2500 to 3500 m above sea level (a.s.l.) on three montane species with contrasting growth habits and leaf economic strategies. While all of the species showed identical increases in foliar δ13C, dark respiration and nitrogen concentration with elevation, contrasting leaf gas exchange and photosynthetic responses were observed between species with different leaf economic strategies. The deciduous shrub Salix atopantha and annual herb Rumex dentatus exhibited increased stomatal (Gs) and mesophyll (Gm) conductance and enhanced photosynthetic capacity at the higher elevation. However, evergreen Quercus spinosa displayed reduced conductance to CO2 that coincided with lower levels of photosynthetic carbon fixation at 3500 m a.s.l. The lower Gs and Gm values of evergreen species at higher elevations currently constrains their rates of A. Future rises in the atmospheric concentration of CO2 ([CO2]) will likely predominantly affect evergreen species with lower specific leaf areas (SLAs) and levels of Gm rather than deciduous species with higher SLA and Gm values. We argue that climate change may affect plant species that compose high-elevation ecosystems differently depending on phenotypic plasticity and adaptive traits affecting leaf economics, as rising [CO2] is likely to benefit evergreen species with thick sclerophyllous leaves. PMID:26433706

Functional Trait Trade-Offs for the Tropical Montane Rain Forest Species Responding to Light from Simulating Experiments

PubMed Central

Mao, Peili; Zang, Runguo; Shao, Hongbo; Yu, Junbao

2014-01-01

Differences among tropical tree species in survival and growth to light play a key role in plant competition and community composition. Two canopy species with contrasting functional traits dominating early and late successional stages, respectively, in a tropical montane rain forest of Hainan Island, China, were selected in a pot experiment under 4 levels of light intensity (full, 50%, 30%, and 10%) in order to explore the adaptive strategies of tropical trees to light conditions. Under each light intensity level, the pioneer species, Endospermum chinense (Euphorbiaceae), had higher relative growth rate (RGR), stem mass ratio (SMR), specific leaf area (SLA), and morphological plasticity while the shade tolerant climax species, Parakmeria lotungensis (Magnoliaceae), had higher root mass ratio (RMR) and leaf mass ratio (LMR). RGR of both species was positively related to SMR and SLA under each light level but was negatively correlated with RMR under lower light (30% and 10% full light). The climax species increased its survival by a conservative resource use strategy through increasing leaf defense and root biomass investment at the expense of growth rate in low light. In contrast, the pioneer increased its growth by an exploitative resource use strategy through increasing leaf photosynthetic capacity and stem biomass investment at the expense of survival under low light. There was a trade-off between growth and survival for species under different light conditions. Our study suggests that tree species in the tropical rainforest adopt different strategies in stands of different successional stages. Species in the earlier successional stages have functional traits more advantageous to grow faster in the high light conditions, whereas species in the late successional stages have traits more favorable to survive in the low light conditions. PMID:25019095

Pediatric Patients Demonstrate Progressive T1-Weighted Hyperintensity in the Dentate Nucleus following Multiple Doses of Gadolinium-Based Contrast Agent.

PubMed

Roberts, D R; Chatterjee, A R; Yazdani, M; Marebwa, B; Brown, T; Collins, H; Bolles, G; Jenrette, J M; Nietert, P J; Zhu, X

2016-12-01

While there have been recent reports of brain retention of gadolinium following gadolinium-based contrast agent administration in adults, a retrospective series of pediatric patients has not previously been reported, to our knowledge. We investigated the relationship between the number of prior gadolinium-based contrast agent doses and increasing T1 signal in the dentate nucleus on unenhanced T1-weighted MR imaging. We hypothesized that despite differences in pediatric physiology and the smaller gadolinium-based contrast agent doses that pediatric patients are typically administered based on weighted-adjusted dosing, the pediatric brain would also demonstrate dose-dependent increasing T1 signal in the dentate nucleus. We included children with multiple gadolinium-based contrast agent administrations at our institution. A blinded reader placed ROIs within the dentate nucleus and adjacent cerebellar white matter. To eliminate reader bias, we also performed automated ROI delineation of the dentate nucleus, cerebellar white matter, and pons. Dentate-to-cerebellar white matter and dentate-to pons ratios were compared with the number of gadolinium-based contrast agent administrations. During 20 years at our institution, 280 patients received at least 5 gadolinium-based contrast agent doses, with 1 patient receiving 38 doses. Sixteen patients met the inclusion/exclusion criteria for ROI analysis. Blinded reader dentate-to-cerebellar white matter ratios were significantly associated with gadolinium-based contrast agent doses (r s = 0.77, P = .001). The dentate-to-pons ratio and dentate-to-cerebellar white matter ratios based on automated ROI placement were also significantly correlated with gadolinium-based contrast agent doses (t = 4.98, P < .0001 and t = 2.73, P < .02, respectively). In pediatric patients, the number of prior gadolinium-based contrast agent doses is significantly correlated with progressive T1-weighted dentate hyperintensity. Definitive confirmation of gadolinium deposition requires tissue analysis. Any potential clinical sequelae of gadolinium retention in the developing brain are unknown. Given this uncertainty, we suggest taking a cautious stance, including the use, in pediatric patients, of higher stability, macrocyclic agents, which in both human and animal studies have been shown to be associated with lower levels of gadolinium deposition, and detailed documentation of dosing. Most important, a patient should not be deprived of a well-indicated contrasted MR examination. © 2016 by American Journal of Neuroradiology.

Metal artefact reduction with cone beam CT: an in vitro study

PubMed Central

Bechara, BB; Moore, WS; McMahan, CA; Noujeim, M

2012-01-01

Background Metal in a patient's mouth has been shown to cause artefacts that can interfere with the diagnostic quality of cone beam CT. Recently, a manufacturer has made an algorithm and software available which reduces metal streak artefact (Picasso Master 3D® machine; Vatech, Hwaseong, Republic of Korea). Objectives The purpose of this investigation was to determine whether or not the metal artefact reduction algorithm was effective and enhanced the contrast-to-noise ratio. Methods A phantom was constructed incorporating three metallic beads and three epoxy resin-based bone substitutes to simulate bone next to metal. The phantom was placed in the centre of the field of view and at the periphery. 10 data sets were acquired at 50–90 kVp. The images obtained were analysed using a public domain software ImageJ (NIH Image, Bethesda, MD). Profile lines were used to evaluate grey level changes and area histograms were used to evaluate contrast. The contrast-to-noise ratio was calculated. Results The metal artefact reduction option reduced grey value variation and increased the contrast-to-noise ratio. The grey value varied least when the phantom was in the middle of the volume and the metal artefact reduction was activated. The image quality improved as the peak kilovoltage increased. Conclusion Better images of a phantom were obtained when the metal artefact reduction algorithm was used. PMID:22241878

Hormones, Nicotine and Cocaine: Clinical Studies

PubMed Central

Mello, Nancy K.

2009-01-01

Nicotine and cocaine each stimulate hypothalamic-pituitary-adrenal and -gonadal axis hormones, and there is increasing evidence that the hormonal milieu may modulate the abuse-related effects of these drugs. This review summarizes some clinical studies of the acute effects of cigarette smoking or IV cocaine on plasma drug and hormone levels, and subjective effects ratings. The temporal covariance between these dependent measures was assessed with a rapid (two min) sampling procedure in nicotine-dependent volunteers or current cocaine users. Cigarette smoking and IV cocaine each stimulated a rapid increase in LH and ACTH, followed by gradual increases in cortisol and DHEA. Positive subjective effects ratings increased immediately after initiation of cigarette smoking or IV cocaine administration. However, in contrast to cocaine’s sustained positive effects (< 20 min), ratings of “High” and “Rush” began to decrease within one or two puffs of a high nicotine cigarette while nicotine levels were increasing. Peak nicotine levels increased progressively after each of three successive cigarettes smoked at 60 min intervals, but the magnitude of the subjective effects ratings and peak ACTH and cortisol levels diminished. Only DHEA increased consistently after successive cigarettes. The possible influence of neuroactive hormones on nicotine dependence and cocaine abuse, and implications for treatment of these addictive disorders is discussed. PMID:19835877

The effect of altitude on cycling performance: a challenge to traditional concepts.

PubMed

Hahn, A G; Gore, C J

2001-01-01

Acute exposure to moderate altitude is likely to enhance cycling performance on flat terrain because the benefit of reduced aerodynamic drag outweighs the decrease in maximum aerobic power [maximal oxygen uptake (VO2max)]. In contrast, when the course is mountainous, cycling performance will be reduced at moderate altitude. Living and training at altitude, or living in an hypoxic environment (approximately 2500 m) but training near sea level, are popular practices among elite cyclists seeking enhanced performance at sea level. In an attempt to confirm or refute the efficacy of these practices, we reviewed studies conducted on highly-trained athletes and, where possible, on elite cyclists. To ensure relevance of the information to the conditions likely to be encountered by cyclists, we concentrated our literature survey on studies that have used 2- to 4-week exposures to moderate altitude (1500 to 3000 m). With acclimatisation there is strong evidence of decreased production or increased clearance of lactate in the muscle, moderate evidence of enhanced muscle buffering capacity (beta m) and tenuous evidence of improved mechanical efficiency (ME) of cycling. Our analysis of the relevant literature indicates that, in contrast to the existing paradigm, adaptation to natural or simulated moderate altitude does not stimulate red cell production sufficiently to increase red cell volume (RCV) and haemoglobin mass (Hb(mass)). Hypoxia does increase serum erthyropoietin levels but the next step in the erythropoietic cascade is not clearly established; there is only weak evidence of an increase in young red blood cells (reticulocytes). Moreover, the collective evidence from studies of highly-trained athletes indicates that adaptation to hypoxia is unlikely to enhance sea level VO2max. Such enhancement would be expected if RCV and Hb(mass) were elevated. The accumulated results of 5 different research groups that have used controlled study designs indicate that continuous living and training at moderate altitude does not improve sea level performance of high level athletes. However, recent studies from 3 independent laboratories have consistently shown small improvements after living in hypoxia and training near sea level. While other research groups have attributed the improved performance to increased RCV and VO2max, we cite evidence that changes at the muscle level (beta m and ME) could be the fundamental mechanism. While living at altitude but training near sea level may be optimal for enhancing the performance of competitive cyclists, much further research is required to confirm its benefit. If this benefit does exist, it probably varies between individuals and averages little more than 1%.

A smart magnetic resonance contrast agent for selective copper sensing.

PubMed

Que, Emily L; Chang, Christopher J

2006-12-20

We describe the synthesis and properties of Copper-Gad-1 (CG1), a new type of smart magnetic resonance (MR) sensor for selective detection of copper. CG1 is composed of a gadolinium contrast agent core tethered to copper-selective recognition motif. Cu2+-induced modulation of inner-sphere water access to the Gd3+ center provides a sensing mechanism for reporting Cu2+ levels by reading out changes in longitudinal proton relaxivity values. CG1 features good selectivity for Cu2+ over abundant biological cations and a 41% increase in relaxivity upon Cu2+ binding and is capable of detecting micromolar changes in Cu2+ concentrations in aqueous media.

Regional TNFα mapping in the brain reveals the striatum as a neuroinflammatory target after ventricular fibrillation cardiac arrest in rats.

PubMed

Janata, Andreas; Magnet, Ingrid A M; Uray, Thomas; Stezoski, Jason P; Janesko-Feldman, Keri; Tisherman, Samuel A; Kochanek, Patrick M; Drabek, Tomas

2014-05-01

Cardiac arrest (CA) triggers neuroinflammation that could play a role in a delayed neuronal death. In our previously established rat model of ventricular fibrillation (VF) CA characterized by extensive neuronal death, we tested the hypothesis that individual brain regions have specific neuroinflammatory responses, as reflected by regional brain tissue levels of tumor necrosis factor (TNF)α and other cytokines. In a prospective study, rats were randomized to 6min (CA6), 8min (CA8) or 10min (CA10) of VF CA, or sham group. Cortex, striatum, hippocampus and cerebellum were evaluated for TNFα and interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12 and interferon gamma at 3h, 6h or 14 d after CA by ELISA and Luminex. Immunohistochemistry was used to determine the cell source of TNFα. CA resulted in a selective TNFα response with significant regional and temporal differences. At 3h after CA, TNFα-levels increased in all regions depending on the duration of the insult. The most pronounced increase was observed in striatum that showed 20-fold increase in CA10 vs. sham, and 3-fold increase vs. CA6 or CA8 group, respectively (p<0.01). TNFα levels in striatum decreased between 3h and 6h, but increased in other regions between 3h and 14 d. TNFα levels remained twofold higher in CA6 vs. shams across brain regions at 14 d (p<0.01). In contrast to pronounced TNFα response, other cytokines showed only a minimal increase in CA6 and CA8 groups vs. sham in all brain regions with the exception that IL-1β increased twofold in cerebellum and striatum (p<0.01). TNFα colocalized with neurons. In conclusion, CA produced a duration-dependent acute TNFα response, with dramatic increase in the striatum where TNFα colocalized with neurons. Increased TNFα levels persist for at least two weeks. This TNFα surge contrasts the lack of an acute increase in other cytokines in brain after CA. Given that striatum is a selectively vulnerable brain region, our data suggest possible role of neuronal TNFα in striatum after CA and identify therapeutic targets for future experiments. This study was approved by the University of Pittsburgh IACUC 1002340A-3. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

17β-Estradiol Alters Oxidative Stress Response Protein Expression and Oxidative Damage in the Uterus

PubMed Central

Yuan, Lisi; Dietrich, Alicia K.; Nardulli, Ann M.

2014-01-01

The steroid hormone 17β-estradiol (E2) has profound effects on the uterus. However, with the E2-induced increase in uterine cell proliferation and metabolism comes increased production of reactive oxygen species (ROS). We examined the expression of an interactive network of oxidative stress response proteins including thioredoxin (Trx), Cu/Zn superoxide dismutase (SOD1), apurinic endonuclease (Ape1), and protein disulfide isomerase (PDI). We demonstrated that treatment of ovariectomized C57BL/6J female mice with E2 increased the mRNA and protein levels of Trx, but decreased SOD1 and Ape1 mRNA and protein expression. In contrast, E2 treatment increased PDI protein levels but had no effect on PDI transcript levels.Interestingly, E2 treatment also increased two markers of cellular damage, lipid peroxidation and protein carbonylation. Our studies suggest that the decreased expression of SOD1 and Ape1 caused by E2 treatment may in the long term result in disruption of ROS regulation and play a role in endometrial carcinogenesis. PMID:24103313

Renal effects of metallothionein induction by zinc in vitro and in vivo.

PubMed

Schanz, Moritz; Schaaf, Lea; Dippon, Juergen; Biegger, Dagmar; Fritz, Peter; Alscher, Mark Dominik; Kimmel, Martin

2017-03-16

Metallothionein (MTT) is an endogenous antioxidant that can be induced by both zinc (Zn) and ischemia. In kidneys, increased MTT expression exerts a putative protective role in diabetes and hypoxia. Our goal was to further investigate the behavior of MTT under the influence of Zn and hypoxia in vitro and in vivo. MTT expression was measured in vitro in cell cultures of proximal tubular cells (LCC-PK1) by immune-histochemistry and real-time PCR after incubation with increasing concentrations of Zn under hypoxic and non-hypoxic conditions. In addition, in vivo studies were carried out in 54 patients to study MTT induction through Zn. This is a sub-study of a prospective, randomized, double-blind trial on prevention of contrast-media-induced nephropathy using Placebo, Zn and N-Acetylcysteine. Blood samples were obtained before and after 2 days p.o. treatment with or without Zn (60 mg). ELISA-based MTT level measurements were done to evaluate the effects of Zn administration. For in vivo analysis, we considered the ratio of MTT to baseline MTT (MTT 1 /MTT 0 ) and the ratio of eGFR (eGFR 1 /eGFR 0 ), correspondingly. In vitro quantitative immuno-histochemical analysis (IHC) and real-time PCR showed that at increasing levels of Zn (5, 10, and 15 μg/ml) led to a progressive increase of MTTs: Median (IQR) expression of IHC also increased progressively from 0.10 (0.09-0.12), 0.15 (0.12-0.18), 0.25 (0.25-0.27), 0.59 (0.48-0.70) (p < 0.0001). Median (IQR) expression of PCR: 0.59 (0.51-1.72), 1.62 (1.38-4.70), 3.58 (3.06-10.42) and 10.81 (9.24-31.47) (p < 0.0001). In contrast, hypoxia did not change MTT-levels in vitro (p > 0.05). In vivo no significant differences (p = 0.96) occurred in MTT-levels after 2 days of Zn administration compared with no Zn intake. Nevertheless, there was a significant correlation between MTT (MTT 1 /MTT 0 ) and eGFR (eGFR 1 /eGFR 0 ) in case of Zn administration (rho = -0.49; 95%-CI: -0.78 to -0.03; p = 0.04). We found that Zn did induce MTTs in vitro, whereas hypoxia had no significant impact. In contrast, no significant increase of MTTs was detected after in vivo administration of Zn. However, there was a significant negative correlation between MTT and eGFR in vivo in case of Zn administration, this could indicate a protective role of MTTs in a setting of reduced kidney function, which is possibly influenced by Zn. ClinicalTrials.gov Identifier: NCT00399256 . Retrospectively registered 11/13/2006.

A modified commercial ultrasound scanner used for in vivo photoacoustic imaging of nude mice injected with non-targeted contrast agents

NASA Astrophysics Data System (ADS)

Jankovic, Ladislav; Shahzad, Khalid; Wang, Yao; Burcher, Michael; Scholle, Frank-Detlef; Hauff, Peter; Mofina, Sabine; Skobe, Mihaela

2008-02-01

Photoacoustic (PA) experiments were performed using a modified commercial ultrasound scanner equipped with an array transducer and a Nd:YAG pumped OPO laser. The contrast agent SIDAG (Bayer Schering Pharma AG, Germany), used to enhance the optical absorption, demonstrated an expected pharmacokinetic behavior of the dye in the tumor and in the bladder of the nude mice. A typical behavior in the tumor consisted of an initial linear increase in PA signal followed by an exponential decay. PA signal approached the pre-injection level after about one hour following the dye injection, which was consistent with the behavior for such contrast agents when used in other imaging modalities, such as fluorescence imaging. The in-vivo spectral PA data from the mouse bladder, conducted 1.5 hours after the dye injection, clearly demonstrated presence of the dye. The multi-spectral PA data was obtained at 760nm, 784nm and 850nm laser excitations. The PA intensities obtained at these three wavelengths accurately matched the dye absorption spectrum. In addition, in the kidney, a clearance organ for this contrast agent, both in-vivo and ex-vivo results demonstrated a significant increase (~ 40%) in the ratio of PA signal at 760nm (the peak of the dye absorption) relative to the signal at 850nm (<1% absorption), indicating significant amounts of the dye in this organ. Our initial results confirm the desired photoacoustic properties of the contrast agent, indicating its great potential to be used for imaging with a commercial array-based ultrasound scanner.

Cytokine pattern in blister fluid and serum of patients with bullous pemphigoid: relationships with disease intensity.

PubMed

Ameglio, F; D'Auria, L; Bonifati, C; Ferraro, C; Mastroianni, A; Giacalone, B

1998-04-01

Few and contrasting data are available in the literature concerning the levels of various cytokines in blister fluid (BF) and in the serum of patients affected with bullous pemphigoid (BP). Using commercially available ELISA kits, this study reports the levels of 11 cytokines detected both in BF and sera of 15 BP patients and compares them with those of 15 control subjects' sera. Generally, no significant differences were observed in BP and control sera. In contrast, interleukin (IL) 1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) showed increased BF levels as compared with BP sera. Two cytokines, IL-11 and IL-12 did not show significant differences between BP BF and sera, while an opposite behaviour was observed for transforming growth factor beta 1 (TGF-beta 1), whose serum levels were higher than the concentrations in BF. Using the number of lesions of the patients as a possible disease intensity marker, significant correlations were found with the BF levels of IL-1 beta, IL-8, TNF-alpha and, most closely, IL-5. These data may have pathogenetic relevance and suggest the possibility that these biological modulators may be used as a quantitative marker of disease intensity.

Search for novel contrast materials in dual-energy x-ray breast imaging using theoretical modeling of contrast-to-noise ratio

NASA Astrophysics Data System (ADS)

Karunamuni, R.; Maidment, A. D. A.

2014-08-01

Contrast-enhanced (CE) dual-energy (DE) x-ray breast imaging uses a low- and high-energy x-ray spectral pair to eliminate soft-tissue signal variation and thereby increase the detectability of exogenous imaging agents. Currently, CEDE breast imaging is performed with iodinated contrast agents. These compounds are limited by several deficiencies, including rapid clearance and poor tumor targeting ability. The purpose of this work is to identify novel contrast materials whose contrast-to-noise ratio (CNR) is comparable or superior to that of iodine in the mammographic energy range. A monoenergetic DE subtraction framework was developed to calculate the DE signal intensity resulting from the logarithmic subtraction of the low- and high-energy signal intensities. A weighting factor is calculated to remove the dependence of the DE signal on the glandularity of the breast tissue. Using the DE signal intensity and weighting factor, the CNR for materials with atomic numbers (Z) ranging from 1 to 79 are computed for energy pairs between 10 and 50 keV. A group of materials with atomic numbers ranging from 42 to 63 were identified to exhibit the highest levels of CNR in the mammographic energy range. Several of these materials have been formulated as nanoparticles for various applications but none, apart from iodine, have been investigated as CEDE breast imaging agents. Within this group of materials, the necessary dose fraction to the LE image decreases as the atomic number increases. By reducing the dose to the LE image, the DE subtraction technique will not provide an anatomical image of sufficient quality to accompany the contrast information. Therefore, materials with Z from 42 to 52 provide nearly optimal values of CNR with energy pairs and dose fractions that provide good anatomical images. This work is intended to inspire further research into new materials for optimized CEDE breast functional imaging.

Search for novel contrast materials in dual-energy x-ray breast imaging using theoretical modeling of contrast-to-noise ratio.

PubMed

Karunamuni, R; Maidment, A D A

2014-08-07

Contrast-enhanced (CE) dual-energy (DE) x-ray breast imaging uses a low- and high-energy x-ray spectral pair to eliminate soft-tissue signal variation and thereby increase the detectability of exogenous imaging agents. Currently, CEDE breast imaging is performed with iodinated contrast agents. These compounds are limited by several deficiencies, including rapid clearance and poor tumor targeting ability. The purpose of this work is to identify novel contrast materials whose contrast-to-noise ratio (CNR) is comparable or superior to that of iodine in the mammographic energy range. A monoenergetic DE subtraction framework was developed to calculate the DE signal intensity resulting from the logarithmic subtraction of the low- and high-energy signal intensities. A weighting factor is calculated to remove the dependence of the DE signal on the glandularity of the breast tissue. Using the DE signal intensity and weighting factor, the CNR for materials with atomic numbers (Z) ranging from 1 to 79 are computed for energy pairs between 10 and 50 keV. A group of materials with atomic numbers ranging from 42 to 63 were identified to exhibit the highest levels of CNR in the mammographic energy range. Several of these materials have been formulated as nanoparticles for various applications but none, apart from iodine, have been investigated as CEDE breast imaging agents. Within this group of materials, the necessary dose fraction to the LE image decreases as the atomic number increases. By reducing the dose to the LE image, the DE subtraction technique will not provide an anatomical image of sufficient quality to accompany the contrast information. Therefore, materials with Z from 42 to 52 provide nearly optimal values of CNR with energy pairs and dose fractions that provide good anatomical images. This work is intended to inspire further research into new materials for optimized CEDE breast functional imaging.

Google Glass Glare: disability glare produced by a head-mounted visual display.

PubMed

Longley, Chris; Whitaker, David

2016-03-01

Head mounted displays are a type of wearable technology - a market that is projected to expand rapidly over the coming years. Probably the most well known example is the device Google Glass (or 'Glass'). Here we investigate the extent to which the device display can interfere with normal visual function by producing monocular disability glare. Contrast sensitivity was measured in two normally sighted participants, 32 and 52 years of age. Data were recorded for the right eye, the left eye and then again in a binocular condition. Measurements were taken both with and without the Glass in place, across a range of stimulus luminance levels using a two-alternative forced-choice methodology. The device produced a significant reduction in contrast sensitivity in the right eye (>0.5 log units). The level of disability glare increased as stimulus luminance was reduced in a manner consistent with intraocular light scatter, resulting in a veiling retinal illuminance. Sensitivity in the left eye was unaffected. A significant reduction in binocular contrast sensitivity occurred at lower luminance levels due to a loss of binocular summation, although binocular sensitivity was not found to fall below the sensitivity of the better monocular level (binocular inhibition). Head mounted displays such as Google Glass have the potential to cause significant disability glare in the eye exposed to the visual display, particularly under conditions of low luminance. They can also cause a more modest binocular reduction in sensitivity by eliminating the benefits of binocular summation. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

Effects of the magnetic resonance imaging contrast agent Gd-DTPA on plant growth and root imaging in rice.

PubMed

Liu, Zan; Qian, Junchao; Liu, Binmei; Wang, Qi; Ni, Xiaoyu; Dong, Yaling; Zhong, Kai; Wu, Yuejin

2014-01-01

Although paramagnetic contrast agents have a wide range of applications in medical studies involving magnetic resonance imaging (MRI), these agents are seldom used to enhance MRI images of plant root systems. To extend the application of MRI contrast agents to plant research and to develop related techniques to study root systems, we examined the applicability of the MRI contrast agent Gd-DTPA to the imaging of rice roots. Specifically, we examined the biological effects of various concentrations of Gd-DTPA on rice growth and MRI images. Analysis of electrical conductivity and plant height demonstrated that 5 mmol Gd-DTPA had little impact on rice in the short-term. The results of signal intensity and spin-lattice relaxation time (T1) analysis suggested that 5 mmol Gd-DTPA was the appropriate concentration for enhancing MRI signals. In addition, examination of the long-term effects of Gd-DTPA on plant height showed that levels of this compound up to 5 mmol had little impact on rice growth and (to some extent) increased the biomass of rice.

Effects of escitalopram, R-citalopram, and reboxetine on serum levels of tumor necrosis factor-α, interleukin-10, and depression-like behavior in mice after lipopolysaccharide administration.

PubMed

Dong, Chao; Zhang, Ji-chun; Yao, Wei; Ren, Qian; Yang, Chun; Ma, Min; Han, Mei; Saito, Ryo; Hashimoto, Kenji

2016-05-01

Inflammation plays a role in the pathophysiology of depression. The purpose of this study is to examine whether the selective serotonin reuptake inhibitor (SSRI) escitalopram, its inactive enantiomer R-citalopram, and selective noradrenaline reuptake inhibitor (NRI) reboxetine, show anti-inflammatory and antidepressant effects in an inflammation-induced model of depression. Pretreatment with escitalopram (1, 3, or 10mg/kg, i.p.) markedly blocked an increase in the serum levels of pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), after a single administration of lipopolysaccharide (LPS; 0.5mg/kg). Furthermore, escitalopram (3 or 10mg/kg) significantly increased the serum levels of the anti-inflammatory cytokine interleukin-10 (IL-10) by a single administration of LPS. In contrast, pretreatment with R-citalopram (10mg/kg, i.p.) or reboxetine (10mg/kg, i.p.) did not affect the alterations in serum levels of TNF-α and IL-10 after LPS administration. Co-administration of reboxetine with escitalopram did not show anti-inflammatory effects. Pretreatment with escitalopram (10mg/kg) significantly attenuated LPS-induced increase of the immobility time in the tail-suspension test (TST) and forced swimming test (FST). In contrast, pretreatment with R-citalopram (10mg/kg), or reboxetine (10mg/kg) did not alter LPS-induced increase of immobility time of TST and FST. Interestingly, co-administration of reboxetine with escitalopram did not show antidepressant effect in this model. These findings suggest that escitalopram, but not R-citalopram and reboxetine, has anti-inflammatory and antidepressant effects in LPS-treated model of depression, and that reboxetine can antagonize the effects of escitalopram in the inflammation model. Therefore, it is likely that serotonergic system plays a key role in the pathophysiology of inflammation-induced depression. Copyright © 2016 Elsevier Inc. All rights reserved.

Fluctuations in Nucleus Accumbens Extracellular Glutamate and Glucose during Motivated Glucose-drinking Behavior: Dissecting the Neurochemistry of Reward

PubMed Central

Wakabayashi, Ken T.; Myal, Stephanie E.; Kiyatkin, Eugene A.

2015-01-01

While motivated behavior involves multiple neurochemical systems, few studies have focused on the role of glutamate, the brain’s excitatory neurotransmitter, and glucose, the energetic substrate of neural activity in reward-related neural processes. Here, we used high-speed amperometry with enzyme-based substrate-sensitive and control, enzyme-free biosensors to examine second-scale fluctuations in the extracellular levels of these substances in the nucleus accumbens shell during glucose-drinking behavior in trained rats. Glutamate rose rapidly after the presentation of a glucose-containing cup and before the initiation of drinking (reward seeking), decreased more slowly to levels below baseline during consumption (sensory reward), and returned to baseline when the ingested glucose reached the brain (metabolic reward). When water was substituted for glucose, glutamate rapidly increased with cup presentation and in contrast to glucose drinking, increased above baseline after rats tasted the water and refused to drink further. Therefore, extracellular glutamate show distinct changes associated with key events of motivated drinking behavior and opposite dynamics during sensory and metabolic components of reward. In contrast to glutamate, glucose increased at each stimulus and behavioral event, showing a sustained elevation during the entire behavior and a robust post-ingestion rise that correlated with the gradual return of glutamate levels to their baseline. By comparing active drinking with passive intra-gastric glucose delivery, we revealed that fluctuations in extracellular glucose are highly dynamic, reflecting a balance between rapid delivery due to neural activity, intense metabolism, and the influence of ingested glucose reaching the brain. PMID:25393775

Effects of external potassium (k) supply on drought tolerances of two contrasting winter wheat cultivars.

PubMed

Wei, Jiguang; Li, Caihong; Li, Yong; Jiang, Gaoming; Cheng, Guanglei; Zheng, Yanhai

2013-01-01

Drought is a common stress limiting crops growth and productivities worldwide. Water deficit may increase cellular membrane permeability, resulting in K outflow. Internal K starvation may disorder plant metabolism and limit plant growth. However, it is seldom reported about the effects of external K on drought tolerance of contrasting wheat cultivars. A hydroponics experiment was carried out in a non-controlled greenhouse. Seedlings of drought-tolerant SN16 and intolerant JM22 were simultaneously treated by five levels of K2CO3 (0, 2.5, 5, 7.5, 10 mM) and two levels of PEG6000 (0, 20%) for 7 days. External K2CO3 significantly increased shoot K(+) content, water potential, chlorophyll content as well as gas exchange, but decreased electrolyte leakage (EL) and MDA content in both cultivars under PEG6000 stress. Antioxidant enzymes activities were up-regulated by PEG6000 while external K2CO3 reduced those changes. Molecular basis was explained by measuring the expression levels of antioxidant enzymes related genes. Shoot and root biomass were also increased by K2CO3 supply under drought stress. Although adequate K2CO3 application enhanced plant growth for both cultivars under drought stress, SN16 was better than JM22 due to its high drought tolerance. Adequate external K may effectively protect winter wheat from drought injuries. We conclude that drought-tolerant wheat combined with adequate external K supply may be a promising strategy for better growth in arid and semi-arid regions.

Anti-VEGF treatment reduces blood supply and increases tumor cell invasion in glioblastoma.

PubMed

Keunen, Olivier; Johansson, Mikael; Oudin, Anaïs; Sanzey, Morgane; Rahim, Siti A Abdul; Fack, Fred; Thorsen, Frits; Taxt, Torfinn; Bartos, Michal; Jirik, Radovan; Miletic, Hrvoje; Wang, Jian; Stieber, Daniel; Stuhr, Linda; Moen, Ingrid; Rygh, Cecilie Brekke; Bjerkvig, Rolf; Niclou, Simone P

2011-03-01

Bevacizumab, an antibody against vascular endothelial growth factor (VEGF), is a promising, yet controversial, drug in human glioblastoma treatment (GBM). Its effects on tumor burden, recurrence, and vascular physiology are unclear. We therefore determined the tumor response to bevacizumab at the phenotypic, physiological, and molecular level in a clinically relevant intracranial GBM xenograft model derived from patient tumor spheroids. Using anatomical and physiological magnetic resonance imaging (MRI), we show that bevacizumab causes a strong decrease in contrast enhancement while having only a marginal effect on tumor growth. Interestingly, dynamic contrast-enhanced MRI revealed a significant reduction of the vascular supply, as evidenced by a decrease in intratumoral blood flow and volume and, at the morphological level, by a strong reduction of large- and medium-sized blood vessels. Electron microscopy revealed fewer mitochondria in the treated tumor cells. Importantly, this was accompanied by a 68% increase in infiltrating tumor cells in the brain parenchyma. At the molecular level we observed an increase in lactate and alanine metabolites, together with an induction of hypoxia-inducible factor 1α and an activation of the phosphatidyl-inositol-3-kinase pathway. These data strongly suggest that vascular remodeling induced by anti-VEGF treatment leads to a more hypoxic tumor microenvironment. This favors a metabolic change in the tumor cells toward glycolysis, which leads to enhanced tumor cell invasion into the normal brain. The present work underlines the need to combine anti-angiogenic treatment in GBMs with drugs targeting specific signaling or metabolic pathways linked to the glycolytic phenotype.

Children's Communication of Basic Level and Subordinate Level Semantic Contrasts.

ERIC Educational Resources Information Center

Kossan, Nancy E.

Developmental differences in preschool children's abilities to communicate about basic and subordinate level semantic contrasts were examined in a referential communication situation. Twenty-four three, four, and five-year-old children communicated with children of the same age and adults about pictures' referents. Speakers talked about one…

Evaluation of the spline reconstruction technique for PET

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

Kastis, George A., E-mail: gkastis@academyofathens.gr; Kyriakopoulou, Dimitra; Gaitanis, Anastasios

2014-04-15

Purpose: The spline reconstruction technique (SRT), based on the analytic formula for the inverse Radon transform, has been presented earlier in the literature. In this study, the authors present an improved formulation and numerical implementation of this algorithm and evaluate it in comparison to filtered backprojection (FBP). Methods: The SRT is based on the numerical evaluation of the Hilbert transform of the sinogram via an approximation in terms of “custom made” cubic splines. By restricting reconstruction only within object pixels and by utilizing certain mathematical symmetries, the authors achieve a reconstruction time comparable to that of FBP. The authors havemore » implemented SRT in STIR and have evaluated this technique using simulated data from a clinical positron emission tomography (PET) system, as well as real data obtained from clinical and preclinical PET scanners. For the simulation studies, the authors have simulated sinograms of a point-source and three digital phantoms. Using these sinograms, the authors have created realizations of Poisson noise at five noise levels. In addition to visual comparisons of the reconstructed images, the authors have determined contrast and bias for different regions of the phantoms as a function of noise level. For the real-data studies, sinograms of an{sup 18}F-FDG injected mouse, a NEMA NU 4-2008 image quality phantom, and a Derenzo phantom have been acquired from a commercial PET system. The authors have determined: (a) coefficient of variations (COV) and contrast from the NEMA phantom, (b) contrast for the various sections of the Derenzo phantom, and (c) line profiles for the Derenzo phantom. Furthermore, the authors have acquired sinograms from a whole-body PET scan of an {sup 18}F-FDG injected cancer patient, using the GE Discovery ST PET/CT system. SRT and FBP reconstructions of the thorax have been visually evaluated. Results: The results indicate an improvement in FWHM and FWTM in both simulated and real point-source studies. In all simulated phantoms, the SRT exhibits higher contrast and lower bias than FBP at all noise levels, by increasing the COV in the reconstructed images. Finally, in real studies, whereas the contrast of the cold chambers are similar for both algorithms, the SRT reconstructed images of the NEMA phantom exhibit slightly higher COV values than those of FBP. In the Derenzo phantom, SRT resolves the 2-mm separated holes slightly better than FBP. The small-animal and human reconstructions via SRT exhibit slightly higher resolution and contrast than the FBP reconstructions. Conclusions: The SRT provides images of higher resolution, higher contrast, and lower bias than FBP, by increasing slightly the noise in the reconstructed images. Furthermore, it eliminates streak artifacts outside the object boundary. Unlike other analytic algorithms, the reconstruction time of SRT is comparable with that of FBP. The source code for SRT will become available in a future release of STIR.« less

Image mottle in abdominal CT.

PubMed

Ende, J F; Huda, W; Ros, P R; Litwiller, A L

1999-04-01

To investigate image mottle in conventional CT images of the abdomen as a function of radiographic technique factors and patient size. Water-filled phantoms simulating the abdomens of adult (32 cm in diameter) and pediatric (16 cm in diameter) patients were used to investigate image mottle in CT as a function of x-ray tube potential and mAs. CT images from 39 consecutive patients with noncontrast liver scans and 49 patients with iodine contrast scans were analyzed retrospectively. Measurements were made of the mean liver parenchyma Hounsfield unit value and the corresponding image mottle. For a given water phantom and x-ray tube potential, image mottle was proportional to the mAs-0.5. Increasing the phantom diameter from 16 cm (pediatric) to 32 cm increased the mottle by a factor of 2.4, and increasing the x-ray tube potential from 80 kVp to 140 kVp reduced the mottle by a factor of 2.5. All patients were scanned at 120 kVp, with no correlation between patient size and the x-ray tube mAs. The mean mottle level was 7.8 +/- 2.2 and 10.0 +/- 2.5 for the noncontrast and contrast studies, respectively. An increase in patient diameter of 3 cm would require approximately 65% more mAs to maintain the same level of image mottle. The mottle in abdominal CT images may be controlled by adjusting radiographic technique factors, which should be adjusted to take into account the size of the patient undergoing the examination.

Responses of Englemann spruce forests to nitrogen fertilization in the Colorado Rocky Mountains

USGS Publications Warehouse

Rueth, H.M.; Baron, Jill S.; Allstott, E.J.

2003-01-01

Two old-growth coniferous forests in Colorado with differing initial soil conditions responded differently to four years of low-level fertilization with ammonium nitrate. The site (Fraser) with an average initial organic horizon soil C:N ratio of 36 and nitrogen (N) pool of 605 kg/ha showed no significant increase in net N mineralization rates. At the Fraser site, foliar and organic horizon soil percentage N increased significantly. In contrast, N mineralization rates and inorganic soil N increased significantly at the site (Loch Vale) with greater soil N (C:N of 24, N pool of 991 kg/ha), while foliar N and soil percentage N in the organic layer did not change. We predict continued fertilization at Fraser will narrow the soil C:N ratio to a point where increases in biogeochemical N cycling and fluxes will be detected. Additional N inputs to the site with already low soil C:N ratios will enhance N mineralization rates and leaching losses. The coniferous forests at Fraser and Loch Vale are similar in species composition, stand age, substrate, aspect, and climate. The differences in soil conditions strong enough to cause contrasting responses to fertilization could be due to differences in atmospheric N deposition. Regardless of the reason, the size of the organic soil N pool and C:N ratio of mature coniferous forests in Colorado controls the responsiveness of N pools and fluxes to fertilization, and even low levels of fertilization are sufficient to initiate measurable biogeochemical changes.

Selective activation of mesolimbic and mesocortical dopamine metabolism in rat brain by infusion of a stable substance P analogue into the ventral tegmental area.

PubMed

Elliott, P J; Alpert, J E; Bannon, M J; Iversen, S D

1986-01-15

Microinfusion of the metabolically stable substance P (SP) agonist, [pGlu5,MePhe8,Sar9]-SP5-11 (DiMe-C7), into the ventral tegmental area (VTA) of rat brain increased levels of the dopamine (DA) metabolite dihydroxyphenylacetic acid in the prefrontal cortex (+ 120%) and nucleus accumbens (+30%) but not in other regions of forebrain. In contrast, infusions of DiMe-C7 or SP into the lateral ventricles or microinfusions of SP into VTA failed to elicit increases in DOPAC levels in forebrain. DA levels were unaffected by SP or DiMe-C7 regardless of the route of administration. These data and previous studies suggest a role for endogenous SP in the modulation of mesocortical and mesolimbic DA neurones.

THE PATHOGENESIS OF HYPERLIPEMIA INDUCED BY MEANS OF SURFACE-ACTIVE AGENTS

PubMed Central

Hirsch, Robert L.; Kellner, Aaron

1956-01-01

Rabbits subjected to subtotal hepatectomy failed to develop increased serum cholesterol levels following parenteral injection of triton WR 1339, the finding indicating that the liver is essential for the establishment of the hypercholesterolemia induced by surface-active agents. The cholesterol content of the livers of rabbits rendered hyperlipemic by means of triton remained unchanged both during the rapid rise of the serum cholesterol levels and during the return to normal values. By contrast, the cholesterol content of the livers of rabbits fed cholesterol rose progressively over a period of 5 weeks, concommittant with the increase in serum cholesterol levels. The findings provide support for the hypothesis that surface-active agents bring about hyperlipemia by altering the circulating lipoproteins in some manner so that they are retained in the circulating body fluids. PMID:13332177

Effects of arginine treatment on nutrition, growth and urea cycle function in seven Japanese boys with late-onset ornithine transcarbamylase deficiency.

PubMed

Nagasaka, Hironori; Yorifuji, Tohru; Murayama, Kei; Kubota, Mitsuru; Kurokawa, Keiji; Murakami, Tomoko; Kanazawa, Masaki; Takatani, Tomozumi; Ogawa, Atsushi; Ogawa, Emi; Yamamoto, Shigenori; Adachi, Masanori; Kobayashi, Kunihiko; Takayanagi, Masaki

2006-09-01

The aim of this study was to investigate the effects of arginine on nutrition, growth and urea cycle function in boys with late-onset ornithine transcarbamylase deficiency (OTCD). Seven Japanese boys with late-onset OTCD enrolled in this study resumed arginine treatment after the cessation of this therapy for a few years. Clinical presentations such as vomiting and unconsciousness, plasma amino acids and urinary orotate excretion were followed chronologically to evaluate urea cycle function and protein synthesis with and without this therapy. In addition to height and body weight, blood levels of proteins, lipids, growth hormone (GH), insulin-like growth factor-I (IGF-I) and IGF-binding protein -3 (IGFBP-3) were monitored. The frequency of hyperammonemic attacks and urinary orotate excretion decreased significantly following the resumption of arginine treatment. Despite showing no marked change in body weight, height increased gradually. Extremely low plasma arginine increased to normal levels, while plasma glutamine and alanine levels decreased considerably. Except for a slight increase in high-density lipoprotein cholesterol level, blood levels of markers for nutrition did not change. In contrast, low serum IGF-I and IGFBP-3 levels increased to age-matched control levels, and normal urinary GH secretion became greater than the level observed in the controls. Arginine treatment is able to reduces attacks of hyperammonemia in boys with late-onset OTCD and to increase their growth.

Premium growth and its effect on employer-sponsored insurance.

PubMed

Vistnes, Jessica; Selden, Thomas

2011-03-01

We use variation in premium inflation and general inflation across geographic areas to identify the effects of downward nominal wage rigidity on employers' health insurance decisions. Using employer level data from the 2000 to 2005 Medical Expenditure Panel Survey-Insurance Component, we examine the effect of premium growth on the likelihood that an employer offers insurance, eligibility rates among employees, continuous measures of employee premium contributions for both single and family coverage, and deductibles. We find that small, low-wage employers are less likely to offer health insurance in response to increased premium inflation, and if they do offer coverage they increase employee contributions and deductible levels. In contrast, larger, low-wage employers maintain their offers of coverage, but reduce eligibility for such coverage. They also increase employee contributions for single and family coverage, but not deductibles. Among high-wage employers, all but the largest increase deductibles in response to cost pressures.

Tissue-specific induction of Hsp90 mRNA and plasma cortisol response in chinook salmon following heat shock, seawater challenge, and handling challenge

USGS Publications Warehouse

Palmisano, Aldo N.; Winton, J.R.; Dickhoff, Walton W.

2000-01-01

In studying the whole-body response of chinook salmon (Oncorhynchus tshawytscha) to various stressors, we found that 5-hour exposure to elevated temperature (mean 21.6??C; + 10.6??C over ambient) induced a marked increase in Hsp90 messenger RNA accumulation in heart, brain, gill, muscle, liver, kidney, and tail fin tissues. The most vital tissues (heart, brain, gill, and muscle) showed the greatest Hsp90-mRNA response, with heart tissue increasing approximately 35-fold, Heat shock induced no increase in plasma cortisol. In contrast, a standard handling challenge induced high plasma cortisol levels, but no elevation in Hsp90 mRNA in any tissue, clearly separating the physiological and cellular stress responses. We saw no increase either in tissue Hsp90 mRNA levels or in plasma cortisol concentrations after exposing the fish to seawater overnight.

Left ventricle size quantification using non-contrast-enhanced cardiac computed tomography--association with cardiovascular risk factors and coronary artery calcium score in the general population: The Heinz Nixdorf Recall Study.

PubMed

Dykun, Iryna; Mahabadi, Amir A; Lehmann, Nils; Bauer, Marcus; Moebus, Susanne; Jöckel, Karl-Heinz; Möhlenkamp, Stefan; Erbel, Raimund; Kälsch, Hagen

2015-08-01

Increased left ventricular (LV) size is associated with cardiovascular mortality and morbidity. Once non-contrast cardiac computed tomography (CT) is performed for other purposes, information of LV size is readily available. To determine the association of gated CT-derived LV size with cardiovascular risk factors and coronary artery calcification (CAC) and to describe age- and gender-specific normative values in a general population cohort. LV area was quantified from non-contrast-enhanced CT in axial, end-diastolic images at a mid-ventricular slice in participants of the population-based Heinz Nixdorf Recall Study, free of known cardiovascular disease. LV index (LVI) was calculated by the quotient of LV area and body surface area (BSA). Crude and adjusted regression analyses were used to determine the association of LVI with risk factors and CAC. Overall, 3926 subjects (age 59 ± 8 years, 53% women) were included in this analysis. From quantification in end-diastolic phase, men had larger LV index (2232 ± 296 mm(2)/m(2) vs. 2088 ± 251 mm(2)/m(2), both P < 0.0001). LVI was strongly correlated systolic blood pressure (men, PE [95% CI]: 22.8 [15.5-30.2] mm(2)/10 mmHg; women, 23.4 [18.1-28.6]), and antihypertensive medication (men, 45.2 [14.7-75.8] mm(2); women: 46.5 [22.7-70.2], all P < 0.005). Cholesterol levels were associated with LVI in univariate analysis, however, correlations were low (R(2) ≤ 0.04). In multivariable regression, blood pressure, antihypertensive medication and cholesterol levels, remained associated with LVI (P < 0.05). LVI was linked with CAC in unadjusted (men, increase of CAC + 1 by 13.0% [1.4-25.8] with increased LVI by 1 standard deviation of LVI, P = 0.03; women, 20.7% [10.0-32.3], P < 0.0001) and risk factor adjusted models (men, 14.6% [3.7-26.6], P = 0.007); women, 17.4% [7.8-27.8], P = 0.0002). Non-contrast cardiac CT derived LV index is associated with body size and hypertension. LVI is weakly linked with CAC-score. Further studies need to evaluate whether assessment of LV dimensions from cardiac CT helps identifying subjects with increased cardiovascular risk. © The Foundation Acta Radiologica 2014.

Reduction in cab and psb A RNA transcripts in response to supplementary ultraviolet-B radiation.

PubMed

Jordan, B R; Chow, W S; Strid, A; Anderson, J M

1991-06-17

The cab and psb A RNA transcript levels have been determined in Pisum sativum leaves exposed to supplementary ultraviolet-B radiation. The nuclear-encoded cab transcripts are reduced to low levels after only 4 h of UV-B treatment and are undetectable after 3 days exposure. In contrast, the chloroplast-encoded psb A transcript levels, although reduced, are present for at least 3 days. After short periods of UV-B exposure (4 h or 8 h), followed by recovery under control conditions, cab RNA transcript levels had not recovered after 1 day, but were re-established to ca. 60% of control levels after 2 more days. Increased irradiance during exposure to UV-B reduced the effect upon cab transcripts, although the decrease was still substantial. These results indicate rapid changes in the cellular regulation of gene expression in response to supplementary UV-B and suggest increased UV-B radiation may have profound consequences for future productivity of sensitive crop species.

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

Alhenc-Gelas, F.; Weare, J.A.; Johnson, R.L. Jr.

CE was purified from human lung, and antisera were raised in rabbits. Antisera inhibited the activity of the purified enzyme from lung and kidney and the plasma CE of normal persons and sarcoid patients. With antisera at a titer of 1:100,000, a sensitive, direct RIA was developed. CE purified from lung or kidney and CE present in normal and in sarcoid plasma gave parallel logit-log displacement lines, suggesting immunological identity. The level of CE in normal human plasma was 400 +/- 131 ng/ml. In untreated sarcoid patients, the enzyme level and activity increased in parallel. There was a negative correlationmore » (r . -0.81) between enzyme level and diffusing capacity of the lung for CO in sarcoid patients. Synthetic inhibitors such as captopril or MK 421 did not interfere with the RIA, permitting enzyme levels to be monitored in patients undergoing acute inhibitor therapy. During administration of MK 421, CE activity was negligible and plasma levels of CE did not change. In contrast, renin activity increased eightfold during the inhibitor therapy.« less

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

Alhenc-Gelas, F.; Weare, J.A.; Johnson, R.L. Jr.

CE (converting enzyme) was purified from human lung, and antisera were raised in rabbits. Antisera inhibited the activity of the purified enzyme from lung and kidney and the plasma CE of normal persons and sarcoid patients. With antisera at a titer of 1:100,000, a sensitive, direct RIA was developed. CE purified from lung or kidney and CE present in normal and in sarcoid plasma gave parallel logit-log displacement lines, suggesting immunological identity. The level of CE in normal human plasma was 400 +/- 131 ng/ml. In untreated sarcoid patients, the enzyme level and activity increased in parallel. There was amore » negative correlation between enzyme level and diffusing capacity of the lung for CO in sarcoid patients. Synthetic inhibitors such as captopril or MK 421 did not interfere with the RIA, permitting enzyme levels to be monitored in patients undergoing acute inhibitor therapy. During administration of MK 421, CE activity was negligible and plasma levels of CE did not change. In contrast, renin activity increased eightfold during the inhibitor therapy.« less

Stress profile influences learning approach in a marine fish

PubMed Central

Trompf, Larissa; Williamson, Jane E.; Brown, Culum

2017-01-01

The spatial learning skills of high and low stress juvenile mulloway (Argyrosomus japonicus) were tested in a dichotomous choice apparatus. Groups of fish were formed based on background blood cortisol levels and required to learn the location of a food reward hidden in one of two compartments. Low stress fish characterised by low background levels of the stress hormone cortisol had higher activity levels and entered both rewarded and unrewarded rooms frequently. Within the first week of exposure, however, their preference for the rewarded room increased, indicative of learning. Fish that had high background levels of cortisol, in contrast, showed low levels of activity but when they chose between the two rooms they chose the rewarded room most often but showed less improvement over time. After 12 days in the apparatus, both low and high stress fish had similar ratios of rewarded vs unrewarded room entrances. Our results suggest that proactive coping styles may increase exposure to novel contexts and thus favour faster learning but at the cost of reduced initial accuracy. PMID:28607840

N-Acetylcysteine added to volume expansion with sodium bicarbonate does not further prevent contrast-induced nephropathy: results from the cardiac angiography in renally impaired patients study.

PubMed

Staniloae, Cezar S; Doucet, Serge; Sharma, Samin K; Katholi, Richard E; Mody, Kanika R; Coppola, John T; Solomon, Richard

2009-06-01

We reviewed data from the multicenter CARE (Cardiac Angiography in Renally Impaired Patients) study to see if benefit could be shown for N-acetylcysteine (NAC) in patients undergoing cardiac angiography who all received intravenous bicarbonate fluid expansion. Four hundred fourteen patients with moderate-to-severe chronic kidney disease were randomized to receive intra-arterial administration of iopamidol-370 or iodixanol-320. All patients were prehydrated with isotonic sodium bicarbonate solution. Each site chose whether or not to administer NAC 1,200 mg twice daily to all patients. Serum creatinine (SCr) levels and estimated glomerular filtration rate were assessed at baseline and 2-5 days after receiving contrast. The primary outcome was a postdose SCr increase 0.5 mg/dL (44.2 mumol/L) over baseline. Secondary outcomes were a postdose SCr increase 25% and the mean peak change in SCr. The NAC group received significantly less hydration (892 +/- 236 mL vs. 1016 +/- 328 mL; P < 0.001) and more contrast volume (146 +/- 74 mL vs. 127 +/- 71 mL; P = 0.009) compared with no-NAC group. SCr increases 0.5 mg/dL occurred in 4.2% (7 of 168 patients) in NAC group and 6.5% (16 of 246 patients) in no-NAC group (P = 0.38); rates of SCr increases 25% were 11.9% and 10.6%, respectively (P = 0.75); mean post-SCr increases were 0.07 mg/dL in NAC group versus 0.11 mg/dL in no-NAC group (P = 0.14). In conclusion, addition of NAC to fluid expansion with sodium bicarbonate failed to reduce the rate of contrast-induced nephropathy (CIN) after the intra-arterial administration of iopamidol or iodixanol to high-risk patients with chronic kidney disease.

The Effects of Betaine on the Nuclear Fractal Dimension, Chromatin Texture, and Proliferative Activity in Hepatocytes in Mouse Model of Nonalcoholic Fatty Liver Disease.

PubMed

Vesković, Milena; Labudović-Borović, Milica; Zaletel, Ivan; Rakočević, Jelena; Mladenović, Dušan; Jorgačević, Bojan; Vučević, Danijela; Radosavljević, Tatjana

2018-04-01

The effects of betaine on hepatocytes chromatin architecture changes were examined by using fractal and gray-level co-occurrence matrix (GLCM) analysis in methionine/choline-deficient (MCD) diet-induced, nonalcoholic fatty liver disease (NAFLD). Male C57BL/6 mice were divided into groups: (1) Control: standard diet; (2) BET: standard diet and betaine supplementation through drinking water (solution 1.5%); (3) MCD group: MCD diet for 6 weeks; (4) MCD+BET: fed with MCD diet + betaine for 6 weeks. Liver tissue was collected for histopathology, immunohistochemistry, and determination of fractal dimension and GLCM parameters. MCD diet induced diffuse micro- and macrovesicular steatosis accompanied with increased Ki67-positive hepatocyte nuclei. Steatosis and Ki67 immunopositivity were less prominent in the MCD+BET group compared with the MCD group. Angular second moment (ASM) and inverse difference moment (IDM) (textural homogeneity markers) were significantly increased in the MCD+BET group versus the MCD group (p<0.001), even though no difference between the MCD and the control group was evident. Heterogeneity parameters, contrast, and correlation were significantly increased in the MCD group versus the control (p<0.001). On the other hand, betaine treatment significantly reduced correlation, contrast, and entropy compared with the MCD group (p<0.001). Betaine attenuated MCD diet-induced NAFLD by reducing fat accumulation and inhibiting hepatocyte proliferation. Betaine supplementation increased nuclear homogeneity and chromatin complexity with reduction of entropy, contrast, and correlation.

Undergraduate Research Program in Atmospheric Science: Houston Ozone Studies

NASA Astrophysics Data System (ADS)

Morris, P. A.; Balimuttajjo, M.; Damon, D.; Herridge, A.; Hromis, A. G.; Litwin, D.; Wright, J. M.

2011-12-01

The Minority University Consortium for Earth and Space Sciences (MUCESS) composed of the University of Houston-Downtown (UHD), Medgar Evers College (City University of New York), South Carolina State University, is an undergraduate atmospheric science program funded by NSF. The program's goal is to increase the participation of minority universities in STEM activities and careers by providing students with the knowledge and skills needed to perform weather balloon launches, interpret ozone and temperature variations in the troposphere and stratosphere. Ozone profiles up to 30 km altitude are obtained via an instrument payload attached to a weather balloon. The payload instrumentation consists of an EN-SCI ECC ozonesonde and an iMET radiosonde. The data is transmitted to a base station in real time and includes pressure, temperature, humidity, and GPS coordinates This presentation is directed towards comparing our 2011 Houston data to data that either UHD or the University of Houston (UH) has collected. Our launches are primarily on Sunday, and UH's on Friday. Our primary objective is to identify ground level ozone variations on Sunday and compare with weekday levels as tropospheric ozone is largely controlled by anthropogenic activities. Ozone levels vary depending on the time of year, temperature, rain, wind direction, chemical plant activities, private and commercial traffic patterns.etc. Our limited Friday launches, supported by UH data, indicate that ground level ozone is generally elevated in contrast to Sunday data, For example, our Friday July 2011 launch detected elevated low-altitude ozone levels with ground level ozone levels of 42 nb that increased to 46 nb from 500 m to 1 km. Other peaks are at 2.7 km (44 nb) and 6km (41 nb), decreasing to 17 nb at the tropopause (12 km). Overall, Sunday low altitude ozone levels are generally lower. Our Sunday ground level ozone data ranges from a low of 25 nb on July 11 to a high of 50 nb on August 1. A combination of wind direction and industrial output variations are likely responsible for the these differences. On July 11, ozone levels decrease slightly from the ground-level values up to 2 km. Above this altitude, significant fluctuations in ozone values ranging from 20 to 40nb occur from 2 to 7 km. These fluctuations inversely correlate with humidity. Relative humidity of 20% corresponding to high ozone and 60% humidity values for low ozone. This probably reflects dilution of ozone with water vapor. In contrast, on August 1 ozone values decrease abruptly at 800 meters to 35 nb with only minor fluctuations with increasing altitude to the tropopause. For both days, the change from ground-level ozone values to the higher altitude patterns correlates with a slight temperature inversion. The Stratospheric ozone also shows a significant contrast on the two days. At 22 km altitude an ozone value of 150 nb is seen on August 1 cf the more typical 110 nb on July 11. The high value seen on August 1 is coincident with a major solar flare. These variations are typical of the range of stratospheric ozone levels seen throughout the year and may be attributable to short-term fluctuations in solar activity.

Knowledge-based iterative model reconstruction: comparative image quality and radiation dose with a pediatric computed tomography phantom.

PubMed

Ryu, Young Jin; Choi, Young Hun; Cheon, Jung-Eun; Ha, Seongmin; Kim, Woo Sun; Kim, In-One

2016-03-01

CT of pediatric phantoms can provide useful guidance to the optimization of knowledge-based iterative reconstruction CT. To compare radiation dose and image quality of CT images obtained at different radiation doses reconstructed with knowledge-based iterative reconstruction, hybrid iterative reconstruction and filtered back-projection. We scanned a 5-year anthropomorphic phantom at seven levels of radiation. We then reconstructed CT data with knowledge-based iterative reconstruction (iterative model reconstruction [IMR] levels 1, 2 and 3; Philips Healthcare, Andover, MA), hybrid iterative reconstruction (iDose(4), levels 3 and 7; Philips Healthcare, Andover, MA) and filtered back-projection. The noise, signal-to-noise ratio and contrast-to-noise ratio were calculated. We evaluated low-contrast resolutions and detectability by low-contrast targets and subjective and objective spatial resolutions by the line pairs and wire. With radiation at 100 peak kVp and 100 mAs (3.64 mSv), the relative doses ranged from 5% (0.19 mSv) to 150% (5.46 mSv). Lower noise and higher signal-to-noise, contrast-to-noise and objective spatial resolution were generally achieved in ascending order of filtered back-projection, iDose(4) levels 3 and 7, and IMR levels 1, 2 and 3, at all radiation dose levels. Compared with filtered back-projection at 100% dose, similar noise levels were obtained on IMR level 2 images at 24% dose and iDose(4) level 3 images at 50% dose, respectively. Regarding low-contrast resolution, low-contrast detectability and objective spatial resolution, IMR level 2 images at 24% dose showed comparable image quality with filtered back-projection at 100% dose. Subjective spatial resolution was not greatly affected by reconstruction algorithm. Reduced-dose IMR obtained at 0.92 mSv (24%) showed similar image quality to routine-dose filtered back-projection obtained at 3.64 mSv (100%), and half-dose iDose(4) obtained at 1.81 mSv.

Tree resistance to Lymantria dispar caterpillars: importance and limitations of foliar tannin composition.

PubMed

Barbehenn, Raymond V; Jaros, Adam; Lee, Grace; Mozola, Cara; Weir, Quentin; Salminen, Juha-Pekka

2009-04-01

The ability of foliar tannins to increase plant resistance to herbivores is potentially determined by the composition of the tannins; hydrolyzable tannins are much more active as prooxidants in the guts of caterpillars than are condensed tannins. By manipulating the tannin compositions of two contrasting tree species, this work examined: (1) whether increased levels of hydrolyzable tannins increase the resistance of red oak (Quercus rubra L.), a tree with low resistance that produces mainly condensed tannins, and (2) whether increased levels of condensed tannins decrease the resistance of sugar maple (Acer saccharum Marsh.), a tree with relatively high resistance that produces high levels of hydrolyzable tannins. As expected, when Lymantria dispar L. caterpillars ingested oak leaves coated with hydrolyzable tannins, levels of hydrolyzable tannin oxidation increased in their midgut contents. However, increased tannin oxidation had no significant impact on oxidative stress in the surrounding midgut tissues. Although growth efficiencies were decreased by hydrolyzable tannins, growth rates remained unchanged, suggesting that additional hydrolyzable tannins are not sufficient to increase the resistance of oak. In larvae on condensed tannin-coated maple, no antioxidant effects were observed in the midgut, and levels of tannin oxidation remained high. Consequently, neither oxidative stress in midgut tissues nor larval performance were significantly affected by high levels of condensed tannins. Post hoc comparisons of physiological mechanisms related to tree resistance revealed that maple produced not only higher levels of oxidative stress in the midgut lumen and midgut tissues of L. dispar, but also decreased protein utilization efficiency compared with oak. Our results suggest that high levels of hydrolyzable tannins are important for producing oxidative stress, but increased tree resistance to caterpillars may require additional factors, such as those that produce nutritional stress.

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

Aschengrau, A.; Zierler, S.; Cohen, A.

To investigate the relationship between community drinking water quality and spontaneous abortion, we compared trace element levels in the drinking water of 286 women having a spontaneous abortion through 27 wk gestation with that of 1,391 women having live births. Trace element levels were gathered from analyses of public tap water supplies from the communities where the women resided during pregnancy. After adjustment for potential confounders, an increase in the frequency of spontaneous abortion was associated with detectable levels of mercury; high levels of arsenic, potassium, and silica; moderately hard water, and surface water. In contrast, a decrease in themore » frequency of spontaneous abortion was associated with high levels of alkalinity and sulfate, and any detectable level of nitrate. These results require further corroboration because there is a paucity of data investigating this issue.« less

Thyroid hormones in the elderly sick: "T4 euthyroidism".

PubMed

Burrows, A W; Shakespear, R A; Hesch, R D; Cooper, E; Aickin, C M; Burke, C W

1975-11-22

Thyroid function and serum levels of triiodothyronine (T3) and thyroxine (T4) were investigated in 79 euthyroid geriatric patients. Of the 59 inpatients and 20 outpatients 35 (59%) and 2, respectively, had low T3 levels. In contrast, 7 (12%) and 6 (30%), respectively, had raised T4 levels. Two further patients were excluded from the study because of raised levels of thyroid-stimulating hormone. Thyroxine-binding globulin was greatly increased in both groups of patients, but low serum albumin levels were present in 31 (39%). Despite these changes free T3 and T4 indices closely followed total T3 and T4 levels. The difference between the two groups of patients did not correlate with body weight, diagnostic categories, age, drug treatment, or duration of stay in hospital.

Thyroid hormones in the elderly sick: "T4 euthyroidism".

PubMed Central

Burrows, A W; Shakespear, R A; Hesch, R D; Cooper, E; Aickin, C M; Burke, C W

1975-01-01

Thyroid function and serum levels of triiodothyronine (T3) and thyroxine (T4) were investigated in 79 euthyroid geriatric patients. Of the 59 inpatients and 20 outpatients 35 (59%) and 2, respectively, had low T3 levels. In contrast, 7 (12%) and 6 (30%), respectively, had raised T4 levels. Two further patients were excluded from the study because of raised levels of thyroid-stimulating hormone. Thyroxine-binding globulin was greatly increased in both groups of patients, but low serum albumin levels were present in 31 (39%). Despite these changes free T3 and T4 indices closely followed total T3 and T4 levels. The difference between the two groups of patients did not correlate with body weight, diagnostic categories, age, drug treatment, or duration of stay in hospital. PMID:811313

Contrast-enhanced digital mammography (CEDM): imaging modeling, computer simulations, and phantom study

NASA Astrophysics Data System (ADS)

Chen, Biao; Jing, Zhenxue; Smith, Andrew

2005-04-01

Contrast enhanced digital mammography (CEDM), which is based upon the analysis of a series of x-ray projection images acquired before/after the administration of contrast agents, may provide physicians critical physiologic and morphologic information of breast lesions to determine the malignancy of lesions. This paper proposes to combine the kinetic analysis (KA) of contrast agent uptake/washout process and the dual-energy (DE) contrast enhancement together to formulate a hybrid contrast enhanced breast-imaging framework. The quantitative characteristics of materials and imaging components in the x-ray imaging chain, including x-ray tube (tungsten) spectrum, filter, breast tissues/lesions, contrast agents (non-ionized iodine solution), and selenium detector, were systematically modeled. The contrast-noise-ration (CNR) of iodinated lesions and mean absorbed glandular dose were estimated mathematically. The x-ray techniques optimization was conducted through a series of computer simulations to find the optimal tube voltage, filter thickness, and exposure levels for various breast thicknesses, breast density, and detectable contrast agent concentration levels in terms of detection efficiency (CNR2/dose). A phantom study was performed on a modified Selenia full field digital mammography system to verify the simulated results. The dose level was comparable to the dose in diagnostic mode (less than 4 mGy for an average 4.2 cm compressed breast). The results from the computer simulations and phantom study are being used to optimize an ongoing clinical study.

Influence of age and splanchnic nerve on the action of melatonin in the adrenomedullary catecholamine content and blood glucose level in the avian group.

PubMed

Mahata, S K; Mandal, A; Ghosh, A

1988-01-01

A single intraperitoneal (IP) melatonin injection (0.5 mg/100 g body wt.) caused an increase in norepinephrine (NE) fluorescence and elevation of NE content in newly-hatched pigeons (Columba livia), but a reduction of NE fluorescence and depletion of NE content in the adrenal medulla of newly-hatched crows (Corvus splendens) after 0.5 h of treatment. In contrast, in adults melatonin caused increase in NE fluorescence and elevation of NE content only in the parakeet (Psittacula krameri). Half an hour of IP melatonin treatment (0.5 mg/100 g body wt.) induced release of epinephrine (E) from the adrenal medulla of newly-hatched pigeon and parakeet. In contrast, in the adults melatonin caused more than a two-fold increase in E in the pigeon, and a significant increase in the crow. Single IP melatonin injection (0.5 mg/100 g body wt.) caused hypoglycemia in the newly-hatched parakeet and adult pigeon, and hyperglycemia in newly-hatched pigeon after 0.5 h of treatment. Melatonin failed to regulate glucose homoeostasis in newly-hatched and adult crow. Splanchnic denervation of the left adrenal gland was performed in the adult pigeon. The right adrenal served as the innervated gland. Melatonin-induced modulation of catecholamines following a single IP injection (0.5 mg/100 g body wt.) revealed significant increases in NE fluorescence and NE content at 4 and 12 h after treatment in the denervated gland only, which gradually approached normal levels 9 days after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Remarkable Reproducibility of Enzyme Activity Profiles in Tomato Fruits Grown under Contrasting Environments Provides a Roadmap for Studies of Fruit Metabolism1[W][OPEN

PubMed Central

Biais, Benoît; Bénard, Camille; Beauvoit, Bertrand; Colombié, Sophie; Prodhomme, Duyên; Ménard, Guillaume; Bernillon, Stéphane; Gehl, Bernadette; Gautier, Hélène; Ballias, Patricia; Mazat, Jean-Pierre; Sweetlove, Lee; Génard, Michel; Gibon, Yves

2014-01-01

To assess the influence of the environment on fruit metabolism, tomato (Solanum lycopersicum ‘Moneymaker’) plants were grown under contrasting conditions (optimal for commercial, water limited, or shaded production) and locations. Samples were harvested at nine stages of development, and 36 enzyme activities of central metabolism were measured as well as protein, starch, and major metabolites, such as hexoses, sucrose, organic acids, and amino acids. The most remarkable result was the high reproducibility of enzyme activities throughout development, irrespective of conditions or location. Hierarchical clustering of enzyme activities also revealed tight relationships between metabolic pathways and phases of development. Thus, cell division was characterized by high activities of fructokinase, glucokinase, pyruvate kinase, and tricarboxylic acid cycle enzymes, indicating ATP production as a priority, whereas cell expansion was characterized by enzymes involved in the lower part of glycolysis, suggesting a metabolic reprogramming to anaplerosis. As expected, enzymes involved in the accumulation of sugars, citrate, and glutamate were strongly increased during ripening. However, a group of enzymes involved in ATP production, which is probably fueled by starch degradation, was also increased. Metabolites levels seemed more sensitive than enzymes to the environment, although such differences tended to decrease at ripening. The integration of enzyme and metabolite data obtained under contrasting growth conditions using principal component analysis suggests that, with the exceptions of alanine amino transferase and glutamate and malate dehydrogenase and malate, there are no links between single enzyme activities and metabolite time courses or levels. PMID:24474652

Evaluation of reconstruction techniques in regional cerebral blood flow SPECT using trade-off plots: a Monte Carlo study.

PubMed

Olsson, Anna; Arlig, Asa; Carlsson, Gudrun Alm; Gustafsson, Agnetha

2007-09-01

The image quality of single photon emission computed tomography (SPECT) depends on the reconstruction algorithm used. The purpose of the present study was to evaluate parameters in ordered subset expectation maximization (OSEM) and to compare systematically with filtered back-projection (FBP) for reconstruction of regional cerebral blood flow (rCBF) SPECT, incorporating attenuation and scatter correction. The evaluation was based on the trade-off between contrast recovery and statistical noise using different sizes of subsets, number of iterations and filter parameters. Monte Carlo simulated SPECT studies of a digital human brain phantom were used. The contrast recovery was calculated as measured contrast divided by true contrast. Statistical noise in the reconstructed images was calculated as the coefficient of variation in pixel values. A constant contrast level was reached above 195 equivalent maximum likelihood expectation maximization iterations. The choice of subset size was not crucial as long as there were > or = 2 projections per subset. The OSEM reconstruction was found to give 5-14% higher contrast recovery than FBP for all clinically relevant noise levels in rCBF SPECT. The Butterworth filter, power 6, achieved the highest stable contrast recovery level at all clinically relevant noise levels. The cut-off frequency should be chosen according to the noise level accepted in the image. Trade-off plots are shown to be a practical way of deciding the number of iterations and subset size for the OSEM reconstruction and can be used for other examination types in nuclear medicine.

Influence of contrast agent dose and ultrasound exposure on cardiomyocyte injury induced by myocardial contrast echocardiography in rats.

PubMed

Miller, Douglas L; Li, Peng; Dou, Chunyan; Gordon, David; Edwards, Chris A; Armstrong, William F

2005-10-01

To detect specific cardiomyocyte injury induced by myocardial contrast material-enhanced echocardiography (ie, myocardial contrast echocardiography) in rats and to ascertain the influences of contrast material dose and ultrasound exposure on this injury. All animal procedures were approved by the university committee for the use and care of animals. Myocardial contrast echocardiography with 1:4 electrocardiographic (ECG) triggering was performed at 1.5 MHz in 61 anesthetized rats. Evans blue (EB) dye was injected as the vital stain for cardiomyocyte injury. At the start of myocardial contrast echocardiography, which lasted 10 minutes, perflutren lipid microsphere-based contrast material was infused through the tail vein for 5 minutes. Premature heartbeats were counted from the ECG record. The numbers of EB-stained cells counted on sections of heart specimens obtained 24 hours after myocardial contrast echocardiography and then either fresh frozen or embedded in paraffin were determined by using fluorescence microscopy. Results were compared statistically by using t tests and Mann-Whitney rank sum tests. EB-stained cells were concentrated in the anterior region of the myocardium. In the paraffin-embedded specimens, EB-stained cells were often accompanied by but largely separate from areas of inflammatory cell infiltration. At end-systolic triggering with a 50 microL/kg dose of microsphere contrast material, the EB-stained cell count increased with increasing peak rarefactional pressure amplitude, with significantly increased cell counts at 1.6 MPa (P < .02) and 2.0 MPa (P < .005) relative to the cell counts at sham myocardial contrast echocardiography. Premature heartbeats had a similar exposure-response relationship; however, number of premature heartbeats and EB-stained cell count did not appear to be directly related (coefficient of determination r2 = 0.03). The EB-stained cell counts at end-diastolic triggering were not significantly different from those at end-systolic triggering (P > .1). EB-stained cell counts increased with increasing contrast material dose, from 10 to 50 microL/kg, at 2.0 MPa. Cardiomyocyte injury was induced by the interaction of ultrasound pulses with contrast agent microbubbles during myocardial contrast echocardiography in rats, and the numbers of injured cells increased with increasing contrast agent dose and ultrasound exposure. RSNA, 2005

Molecular mechanism of brain impairment caused by drinking-acquired fluorosis and selenium intervention.

PubMed

Zheng, Xiangren; Sun, Yan; Ke, Lulu; Ouyang, Wei; Zhang, Zigui

2016-04-01

This study investigated the molecular mechanism of brain impairment induced by drinking fluoridated water and selenium intervention. Results showed that the learning and memory of rats in NaF group significantly decreased. Moreover, the number of apoptotic cells, the expression levels of Cytc mRNA and protein, and the expression levels of Caspase-9 and Caspase-3 mRNA significantly increased; by contrast, Caspase-9 and Caspase-3 protein levels significantly decreased. Compared with the NaF group, the mRNA levels of Cytc and Caspase-9, as well as the protein levels of Cytc in NaF+Se group, significantly decreased. Conversely, the protein levels of Caspase-3 and Caspase-9, as well as the mRNA levels of Caspase-3, significantly increased. Thus, the mitochondrial CytC-Caspase-9-Caspase-3 apoptosis pathway in the hippocampus was one of the mechanisms leading to fluorosis-induced brain damage. Furthermore, the Cytc signaling molecules were possibly the key target molecules in fluorosis-induced apoptosis, and selenium could alleviate fluorosis-induced brain injury. Copyright © 2016 Elsevier B.V. All rights reserved.

Safety of cerebral angiography and neuroendovascular therapy in patients with chronic kidney disease.

PubMed

Kim, Jae; Male, Shailesh; Jagadeesan, Bharathi D; Streib, Christopher; Tummala, Ramachandra P

2018-05-01

Contrast-induced nephropathy is a common clinical concern in patients undergoing neuroendovascular procedures, especially in those with pre-existent kidney disease. We aimed to define the incidence of contrast-induced nephropathy in these high-risk patients in our practice. We analyzed data retrospectively from patients undergoing neuroendovascular procedures at two academic medical centers over a 4-year period. Contrast-induced nephropathy was determined by an absolute increase in serum creatinine of 0.5 mg/dL or a rise from its baseline value by ≥ 25%, at 48-72 h after exposure to contrast agent after excluding other causes of renal impairment. High-risk patients were identified as those with pre-procedural estimated glomerular filtration rate < 60 mL/min irrespective of creatinine level, corresponding to stages 3-5 of chronic kidney disease. One hundred eighty-five high-risk patients undergoing conventional cerebral angiography and neuroendovascular interventions were identified. Only 1 out of 184 (0.54%) high-risk patients developed contrast-induced nephropathy. That one patient had stage 5 chronic kidney disease and multiple other risk factors. We have observed a very low rate of renal injury in patients with chronic kidney disease, traditionally considered high risk for neuroendovascular procedures. Multiple factors may be responsible in the risk reduction of contrast-induced nephropathy in this patient population.

Nicotinamide megadosing increases hepatic poly(ADP-ribose) levels in choline-deficient rats.

PubMed

ApSimon, M M; Rawling, J M; Kirkland, J B

1995-07-01

Previous work in our laboratory has shown that dietary megadoses of nicotinamide, used in the prevention of diabetes, cause increases in hepatic poly(ADP-ribose). Poly(ADP-ribose) is synthesized from NAD+ by a nuclear enzyme, poly(ADP-ribose)polymerase, which is activated by DNA strand breaks. The nicotinamide-induced increase in poly(ADP-ribose) could result from an increase in substrate, NAD+, or the induction of strand breaks in DNA. Strand breaks may result from the depletion of single carbon groups, through the excretion of methylated derivatives of nicotinamide. To differentiate between these mechanisms, a 3 x 3 factorial experiment was conducted in which rats were fed diets containing various supplements of choline bitartrate (0, 2, 20 g/kg diet) and nicotinamide (0, 1, 2 g/kg diet). At the conclusion of treatments, blood NAD+ and liver lipid, NAD+ and poly(ADP-ribose) levels were determined. Choline deficiency caused the characteristic accumulation of fat in the liver at all levels of nicotinamide. In choline deficient rats, nicotinamide supplements further increased liver lipid concentration. Blood and liver NAD+ concentrations were increased by nicotinamide supplementation, irrespective of choline status. In contrast, liver poly(ADP-ribose) levels were increased by nicotinamide supplementation only in choline deficient rats. These results show that nicotinamide-induced increases in poly(ADP-ribose) levels appear to be dependent on decreased methyl donor status and suggest that adequate choline status is important for preventing some deleterious effects of nicotinamide treatment.

Diagnostic value of quantitative contrast-enhanced ultrasound (CEUS) for early detection of renal hyperperfusion in diabetic kidney disease.

PubMed

Wang, Ling; Wu, Jian; Cheng, Jia-Fen; Liu, Xin-Ying; Ma, Fang; Guo, Le-Hang; Xu, Jun-Mei; Wu, Tianfu; Mohan, Chandra; Peng, Ai; Xu, Hui-Xiong; Song, Ya-Xiang

2015-12-01

To investigate the diagnostic value of quantitative contrast-enhanced ultrasound (CEUS) for early detection of renal hyperperfusion in diabetic kidney disease (DKD). 55 DKD patients with estimated glomerular filtration rate (eGFR) >30 ml/min/1.73 m(2) and 26 normal controls (NCs) were enrolled. Clinical data was well documented. Blood samples were drawn for evaluation of renal function including blood urea nitrogen (BUN), serum creatinine (SCr) and serum uric acid (SUA), and urine samples were assayed for total protein quantification, and various microprotein markers. According to eGFR level, DKD patients were divided into early-stage DKD (eGFR ≥90 ml/min/1.73 m(2), n = 18) and middle-stage DKD (eGFR 30-90 ml/min/1.73 m(2), n = 37). Based on urinary microalbumin/creatinine ratio (MALB/UCR), early-stage DKD patients were further classified into two groups: MALB/UCR <10 g/mol (n = 11) and MALB/UCR ≥10 g/mol (n = 7). Then, CEUS was performed to observe the real-time renal perfusion, and low acoustic power contrast-specific imaging was used for quantitative analysis. The renal perfusion images of CEUS were well developed successively. The corresponding perfusion curves based on echo-power signals in time series were constructed. Quantitative analysis showed that area under the descending curve (AUC2) was significantly increased in early-stage DKD compared to middle-stage DKD (p < 0.05), but AUC showed no significant difference. Further comparison between different MALB/UCR levels of early-stage DKD showed that patients with MALB/UCR ≥10 g/mol had significantly increased levels of AUC, AUC2 and proteinuria than patients with low MALB/UCR (p < 0.05). Also, high MALB/UCR DKD patients had increased proteinuria but similar eGFR compared to low MALB/UCR patients. Renal microvascular hyperperfusion may be responsible for overt proteinuria until decline of renal filtration in DKD. AUC2 could be an early and sensitive marker for early renal injury and renal microvascular hyperperfusion in DKD.

Technological aspects of lactose-hydrolyzed milk powder.

PubMed

Torres, Jansen Kelis Ferreira; Stephani, Rodrigo; Tavares, Guilherme M; de Carvalho, Antônio Fernandes; Costa, Renata Golin Bueno; de Almeida, Carlos Eduardo Rocha; Almeida, Mariana Ramos; de Oliveira, Luiz Fernando Cappa; Schuck, Pierre; Perrone, Ítalo Tuler

2017-11-01

Few reports describe the effect of lactose hydrolysis on the properties of milk powder during production and storage. Hence, the aim of this study was to evaluate the effects of five different levels of enzymatic lactose hydrolysis during the production and storage of milk powder. As the lactose hydrolysis rate increased, adhesion to the drying chamber also increased, due to higher levels of particle agglomeration. Additionally, more brown powder was obtained when the lactose hydrolysis rate was increased, which in turn negatively affected rehydration ability. Using Raman spectroscopy, crystallization of the lactose residues in various samples was assessed over 6weeks of accelerated aging at a room temperature environment with 75.5% of air moisture. Products with 25% or greater lactose hydrolysis showed no signs of crystallization, in contrast to the non-hydrolyzed sample. Copyright © 2017. Published by Elsevier Ltd.

Molecular mechanisms of continuous light inhibition of Atlantic salmon parr-smolt transformation

USGS Publications Warehouse

Stefansson, S.O.; Nilsen, Tom O.; Ebbesson, Lars O.E.; Wargelius, A.; Madsen, Steffen S.; Bjornsson, B. Th; McCormick, S.D.

2007-01-01

Atlantic salmon (Salmo salar) rely on changes in photoperiod for the synchronization of the developmental events constituting the parr-smolt transformation. In the absence of photoperiod cues, parr-smolt transformation is incomplete, and such 'pseudo-smolts' normally fail to adapt to seawater. The present study addresses the endocrine and molecular mechanisms controlling the development of hypo-osmoregulatory ability and how artificial photoperiod can disrupt these changes. Juvenile Atlantic salmon reared under constant light (LL) from first feeding, were separated into two groups, and exposed to either LL or simulated natural photoperiod (LDN) from October, eight months prior to the expected completion of smoltification. Juveniles reared on LL grew well, but failed to show the smolt-related reduction in condition factor in spring. Gill mRNA levels of Na+, K+-ATPase (NKA) isoform ??1a decreased in LDN fish through completion of parr-smolt transformation, while levels remained unchanged in the LL group. In contrast, ??1b expression increased 6-fold in the LDN group between February and May, again with no change in the LL group. Further, Na+, K+, 2Cl- co-transporter (NKCC) showed a transient increase in expression in smolts on LDN between February and May, while no changes in mRNA levels were seen in juveniles under LL. Consequently, gill NKA activity and NKA ?? and NKCC protein abundance were significantly lower in juveniles on LL than in smolts on LDN. LL fish in spring had lower circulating levels of thyroid hormones (THs), growth hormone (GH) and cortisol. Gill GH-receptor mRNA levels, determined by quantitative PCR, were less than 50% of controls. In contrast, circulating levels of IGF-1 and gill IGF-1 receptor expression, were comparable to controls. Our findings show that continuous light prevents the completion of parr-smolt transformation at a very basic level, disrupting the natural up-regulation of key elements of the endocrine system involved in the regulation of the parr-smolt transformation, and consequently inhibiting the smoltification-related increase in expression, abundance and activity of gill ion transport proteins. ?? 2007 Elsevier B.V. All rights reserved.

Computed radiography utilizing laser-stimulated luminescence: detectability of simulated low-contrast radiographic objects.

PubMed

Higashida, Y; Moribe, N; Hirata, Y; Morita, K; Doudanuki, S; Sonoda, Y; Katsuda, N; Hiai, Y; Misumi, W; Matsumoto, M

1988-01-01

Threshold contrasts of low-contrast objects with computed radiography (CR) images were compared with those of blue and green emitting screen-film systems by employing the 18-alternative forced choice (18-AFC) procedure. The dependence of the threshold contrast on the incident X-ray exposure and also the object size was studied. The results indicated that the threshold contrasts of CR system were comparable to those of blue and green screen-film systems and decreased with increasing object size, and increased with decreasing incident X-ray exposure. The increase in threshold contrasts was small when the relative incident exposure decreased from 1 to 1/4, and was large when incident exposure was decreased further.

Comparison of effects of dose on image quality in digital breast tomosynthesis across multiple vendors

NASA Astrophysics Data System (ADS)

Zhao, Amy; Santana, Maira; Samei, Ehsan; Lo, Joseph

2017-03-01

In traditional radiography and computed tomography (CT), contrast is an important measure of image quality that, in theory, does not vary with dose. While increasing dose may increase the overall contrast-to-noise ratio (CNR), the contrast in an image should be primarily dependent on variation in tissue density and attenuation. We investigated the behavior of all three currently FDA-approved vendors' 3D DBT systems (Siemens, Hologic, and General Electric (GE)) using the Computerized Imaging Reference Systems (CIRS) Model 011A Breast Phantom and found that for both Siemens and Hologic systems, contrast increased with dose across multiple repeated trials. For these two systems, experimental CNR also appeared to increase above the expected CNR, which suggests that these systems seem to have introduced post-processing by manipulation of contrast, and thus DBT data cannot be used to reliably quantify tissue characteristics. Additional experimentation with both 2D mammography and 3D DBT systems from GE in addition to the previously mentioned vendors, however, suggested that this relationship is not true for all systems. An initial comparison of contrast vs. dose showed no relationship between contrast and dose for 2D mammography, with the contrast remaining relatively constant in the dose range of 33% of the automatic exposure control setting (AEC) to 300% AEC for all three vendors. The GE DBT system also did not exhibit increased contrast with increased dose, suggesting that the behavior of 3D DBT systems is vendor-specific.

Vitamin E, γ-tocotrienol, Protects Against Buthionine Sulfoximine-Induced Cell Death by Scavenging Free Radicals in SH-SY5Y Neuroblastoma Cells.

PubMed

Tan, Jen-Kit; Then, Sue-Mian; Mazlan, Musalmah; Jamal, Rahman; Ngah, Wan Zurinah Wan

2016-01-01

The induction of reactive oxygen species (ROS) to selectively kill cancer cells is an important feature of radiotherapy and various chemotherapies. Depletion of glutathione can induce apoptosis in cancer cells or sensitize them to anticancer treatments intended to modulate ROS levels. In contrast, antioxidants protect cancer cells from oxidative stress-induced cell death by scavenging ROS. The role of exogenous antioxidants in cancer cells under oxidative insults remains controversial and unclear. This study aimed to identify protective pathways modulated by γ-tocotrienol (γT3), an isomer of vitamin E, in human neuroblastoma SH-SY5Y cells under oxidative stress. Using buthionine sulfoximine (BSO) as an inhibitor of glutathione synthesis, we found that BSO treatment reduced the viability of SH-SY5Y cells. BSO induced cell death by increasing apoptosis, decreased the level of reduced glutathione (GSH), and increased ROS levels in SH-SY5Y cells. Addition of γT3 increased the viability of BSO-treated cells, suppressed apoptosis, and decreased the ROS level induced by BSO, while the GSH level was unaffected. These results suggest that decreasing GSH levels by BSO increased ROS levels, leading to apoptosis in SH-SY5Y cells. γT3 attenuated the BSO-induced cell death by scavenging free radicals.

The effect of major adverse renal cardiovascular event (MARCE) incidence, procedure volume, and unit cost on the hospital savings resulting from contrast media use in inpatient angioplasty.

PubMed

Keuffel, Eric; McCullough, Peter A; Todoran, Thomas M; Brilakis, Emmanouil S; Palli, Swetha R; Ryan, Michael P; Gunnarsson, Candace

2018-04-01

To determine the net economic impact of switching from low-osmolar contrast media (LOCM) to iso-osmolar contrast media (IOCM; iodixanol) in patients undergoing inpatient coronary or peripheral angioplasty in the United States (US). A budget impact model (BIM) was developed from a hospital perspective. Nationally representative procedural and contrast media prevalence rates, along with MARCE (major adverse renal cardiovascular event) incidence and episode-related cost data were derived from Premier Hospital Data (October 2014 to September 2015). A previously estimated relative risk reduction in MARCE associated with IOCM usage (9.3%) was applied. The higher cost of IOCM was included when calculating the net impact estimates at the aggregate, hospital type, and per hospital levels. One-way (±25%) and probabilistic sensitivity analyses identified the model's most important inputs. Based on weighted analysis, 513,882 US inpatient angioplasties and 35,610 MARCE cases were estimated annually. Switching to an "IOCM only" strategy from a "LOCM only" strategy increases contrast media cost, but prevents 2,900 MARCE events. The annual budget impact was an estimated saving of $30.71 million, aggregated across all US hospitals, $6,316 per hospital, or $60 per procedure. Net savings were maintained across all univariate sensitivity analyses. While MARCE/event-free cost differential was the most important factor driving total net savings for hospitals in the Northeast and West, procedural volume was important in the Midwest and rural locations. Switching to an "IOCM only" strategy from a "LOCM only" approach yields substantial net global savings to hospitals, both at the national level and within hospital sub-groups. Hospital administrators should maintain awareness of the factors that are likely to be more influential for their hospital and recognize that purchasing on the basis of lower contrast media cost may result in higher overall costs for patients undergoing inpatient angioplasty.

A Third-Generation Adaptive Statistical Iterative Reconstruction Technique: Phantom Study of Image Noise, Spatial Resolution, Lesion Detectability, and Dose Reduction Potential.

PubMed

Euler, André; Solomon, Justin; Marin, Daniele; Nelson, Rendon C; Samei, Ehsan

2018-06-01

The purpose of this study was to assess image noise, spatial resolution, lesion detectability, and the dose reduction potential of a proprietary third-generation adaptive statistical iterative reconstruction (ASIR-V) technique. A phantom representing five different body sizes (12-37 cm) and a contrast-detail phantom containing lesions of five low-contrast levels (5-20 HU) and three sizes (2-6 mm) were deployed. Both phantoms were scanned on a 256-MDCT scanner at six different radiation doses (1.25-10 mGy). Images were reconstructed with filtered back projection (FBP), ASIR-V with 50% blending with FBP (ASIR-V 50%), and ASIR-V without blending (ASIR-V 100%). In the first phantom, noise properties were assessed by noise power spectrum analysis. Spatial resolution properties were measured by use of task transfer functions for objects of different contrasts. Noise magnitude, noise texture, and resolution were compared between the three groups. In the second phantom, low-contrast detectability was assessed by nine human readers independently for each condition. The dose reduction potential of ASIR-V was estimated on the basis of a generalized linear statistical regression model. On average, image noise was reduced 37.3% with ASIR-V 50% and 71.5% with ASIR-V 100% compared with FBP. ASIR-V shifted the noise power spectrum toward lower frequencies compared with FBP. The spatial resolution of ASIR-V was equivalent or slightly superior to that of FBP, except for the low-contrast object, which had lower resolution. Lesion detection significantly increased with both ASIR-V levels (p = 0.001), with an estimated radiation dose reduction potential of 15% ± 5% (SD) for ASIR-V 50% and 31% ± 9% for ASIR-V 100%. ASIR-V reduced image noise and improved lesion detection compared with FBP and had potential for radiation dose reduction while preserving low-contrast detectability.

Multi-Model Assessment of the Factors Driving Stratospheric Ozone Evolution Over the 21st Century

NASA Technical Reports Server (NTRS)

Oman, L. D.; Plummer, D. A.; Waugh, D. W.; Austin, J.; Scinocca, J.; Douglass, A. R.; Salawitch, R. J.; Canty, T.; Akiyoshi, H.; Bekki, S.;

A thyroid hormone receptor mutation that dissociates thyroid hormone regulation of gene expression in vivo

PubMed Central

Machado, Danielle S.; Sabet, Amin; Santiago, Leticia A.; Sidhaye, Aniket R.; Chiamolera, Maria I.; Ortiga-Carvalho, Tania M.; Wondisford, Fredric E.

2009-01-01

Resistance to thyroid hormone (RTH) is most often due to point mutations in the β-isoform of the thyroid hormone (TH) receptor (TR-β). The majority of mutations involve the ligand-binding domain, where they block TH binding and receptor function on both stimulatory and inhibitory TH response elements. In contrast, a few mutations in the ligand-binding domain are reported to maintain TH binding and yet cause RTH in certain tissues. We introduced one such naturally occurring human RTH mutation (R429Q) into the germline of mice at the TR-β locus. R429Q knock-in (KI) mice demonstrated elevated serum TH and inappropriately normal thyroid-stimulating hormone (TSH) levels, consistent with hypothalamic–pituitary RTH. In contrast, 3 hepatic genes positively regulated by TH (Dio1, Gpd1, and Thrsp) were increased in R429Q KI animals. Mice were then rendered hypothyroid, followed by graded T3 replacement. Hypothyroid R429Q KI mice displayed elevated TSH subunit mRNA levels, and T3 treatment failed to normally suppress these levels. T3 treatment, however, stimulated pituitary Gh levels to a greater degree in R429Q KI than in control mice. Gsta, a hepatic gene negatively regulated by TH, was not suppressed in R429Q KI mice after T3 treatment, but hepatic Dio1 and Thrsp mRNA levels increased in response to TH. Cardiac myosin heavy chain isoform gene expression also showed a specific defect in TH inhibition. In summary, the R429Q mutation is associated with selective impairment of TH-mediated gene repression, suggesting that the affected domain, necessary for TR homodimerization and corepressor binding, has a critical role in negative gene regulation by TH. PMID:19439650

Nicotinamide extends replicative lifespan of human cells.

PubMed

Kang, Hyun Tae; Lee, Hyung Il; Hwang, Eun Seong

2006-10-01

We found that an ongoing application of nicotinamide to normal human fibroblasts not only attenuated expression of the aging phenotype but also increased their replicative lifespan, causing a greater than 1.6-fold increase in the number of population doublings. Although nicotinamide by itself does not act as an antioxidant, the cells cultured in the presence of nicotinamide exhibited reduced levels of reactive oxygen species (ROS) and oxidative damage products associated with cellular senescence, and a decelerated telomere shortening rate without a detectable increase in telomerase activity. Furthermore, in the treated cells growing beyond the original Hayflick limit, the levels of p53, p21WAF1, and phospho-Rb proteins were similar to those in actively proliferating cells. The nicotinamide treatment caused a decrease in ATP levels, which was stably maintained until the delayed senescence point. Nicotinamide-treated cells also maintained high mitochondrial membrane potential but a lower respiration rate and superoxide anion level. Taken together, in contrast to its demonstrated pro-aging effect in yeast, nicotinamide extends the lifespan of human fibroblasts, possibly through reduction in mitochondrial activity and ROS production.

Reciprocal Longitudinal Associations Between Adolescent Twin Gambling and Delinquency.

PubMed

Vitaro, Frank; C Hartl, Amy; Laursen, Brett; Brendgen, Mara; Dionne, Ginette; Boivin, Michel

2015-12-01

This study examined sibling influence over gambling involvement and delinquency in a sample of 628 twins (151 male dyads, 163 female dyads). Self-reports of gambling involvement and delinquency were collected for each twin at ages 13, 14 and 15 years. Results revealed evidence of between-twin influence. Higher levels of an adolescent's delinquency predicted an increase in his or her co-twin's delinquency from age 13 to age 14 and from age 14 to age 15. In contrast, gambling behavior was unaffected by the co-twin's gambling involvement. Within-twins, higher initial levels of delinquency predicted a subsequent increase in gambling behavior from age 13 to age 14 and again from age 14 to age 15, and higher initial levels of gambling involvement predicted an increase in delinquency from age 14 to age 15. Between and within siblings effects are discussed in light of the scant literature on (a) sibling influence on gambling, and (b) the links between gambling and delinquency.

Acquiring skill at medical image inspection: learning localized in early visual processes

NASA Astrophysics Data System (ADS)

Sowden, Paul T.; Davies, Ian R. L.; Roling, Penny; Watt, Simon J.

1997-04-01

Acquisition of the skill of medical image inspection could be due to changes in visual search processes, 'low-level' sensory learning, and higher level 'conceptual learning.' Here, we report two studies that investigate the extent to which learning in medical image inspection involves low- level learning. Early in the visual processing pathway cells are selective for direction of luminance contrast. We exploit this in the present studies by using transfer across direction of contrast as a 'marker' to indicate the level of processing at which learning occurs. In both studies twelve observers trained for four days at detecting features in x- ray images (experiment one equals discs in the Nijmegen phantom, experiment two equals micro-calcification clusters in digitized mammograms). Half the observers examined negative luminance contrast versions of the images and the remainder examined positive contrast versions. On the fifth day, observers swapped to inspect their respective opposite contrast images. In both experiments leaning occurred across sessions. In experiment one, learning did not transfer across direction of luminance contrast, while in experiment two there was only partial transfer. These findings are consistent with the contention that some of the leaning was localized early in the visual processing pathway. The implications of these results for current medical image inspection training schedules are discussed.

Time-Dependent Changes in Increased Levels of Plasma Irisin and Muscle PGC-1α and FNDC5 after Exercise in Mice.

PubMed

Pang, Minhui; Yang, Jianwei; Rao, Jiaming; Wang, Haiqing; Zhang, Jiayi; Wang, Shengyong; Chen, Xiongfei; Dong, Xiaomei

2018-02-01

Exercise induces the expression of peroxisome proliferator-activated receptor gamma co-activator 1-α (PGC-1α) in skeletal muscle, which promotes the cleavage of fibronectin type III domain-containing protein 5 (FNDC5) to irisin. To explore the relationship between irisin and its regulators, we analyzed the plasma irisin levels and the muscle levels of FNDC5 and PGC-1α after exercise. Male C57BL/6J mice underwent a treadmill exercise (60% of VO 2max ) for 30 min or one hour (h), and blood and gastrocnemius samples were collected before exercise (pre-exercise), immediately after exercise, and during 24-h recovery after 1-h exercise. We found that plasma irisin levels were significantly increased during exercise (P < 0.05), while FNDC5 protein levels were not significantly increased. Moreover, PGC-1α mRNA and protein levels were significantly increased during 30-min exercise, but were decreased during 1-h exercise. After 1-h exercise, the irisin levels peaked at 6 h (20.71 ± 0.25 ng/ml) and decreased to pre-exercise levels by 24 h (15.45 ± 0.27 ng/ml). Likewise, PGC-1α mRNA and protein levels were increased at 1 h and maintained at elevated levels for 6 h; thereafter, the expression levels of PGC1-α protein were decreased to pre-exercise levels at 12 h. Thus, the restoration of PGC-1α expression to the pre-exercise levels was followed by the decrease in plasma irisin levels. By contrast, during 24-h recovery, the expression levels of FNDC5 mRNA and protein were maintained at elevated levels. These results suggest that the coordinated expression of FNDC5 and PGC-1α may contribute to the increased levels of plasma irisin after exercise.

Prenatal Loud Music and Noise: Differential Impact on Physiological Arousal, Hippocampal Synaptogenesis and Spatial Behavior in One Day-Old Chicks

PubMed Central

Sanyal, Tania; Kumar, Vivek; Nag, Tapas Chandra; Jain, Suman; Sreenivas, Vishnu; Wadhwa, Shashi

2013-01-01

Prenatal auditory stimulation in chicks with species-specific sound and music at 65 dB facilitates spatial orientation and learning and is associated with significant morphological and biochemical changes in the hippocampus and brainstem auditory nuclei. Increased noradrenaline level due to physiological arousal is suggested as a possible mediator for the observed beneficial effects following patterned and rhythmic sound exposure. However, studies regarding the effects of prenatal high decibel sound (110 dB; music and noise) exposure on the plasma noradrenaline level, synaptic protein expression in the hippocampus and spatial behavior of neonatal chicks remained unexplored. Here, we report that high decibel music stimulation moderately increases plasma noradrenaline level and positively modulates spatial orientation, learning and memory of one day-old chicks. In contrast, noise at the same sound pressure level results in excessive increase of plasma noradrenaline level and impairs the spatial behavior. Further, to assess the changes at the molecular level, we have quantified the expression of functional synapse markers: synaptophysin and PSD-95 in the hippocampus. Compared to the controls, both proteins show significantly increased expressions in the music stimulated group but decrease in expressions in the noise group. We propose that the differential increase of plasma noradrenaline level and altered expression of synaptic proteins in the hippocampus are responsible for the observed behavioral consequences following prenatal 110 dB music and noise stimulation. PMID:23861759

Oil and gas developments in Far East in 1984

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

Soeparjadi, R.A.; Valachi, L.Z.; Sosromihardjo, S.

1985-10-01

In 1984, the Far East region was no exception to the general worldwide slowdown in petroleum activities, although exploration and production were maintained at relatively high rates. Exploratory drilling decreased by 14%, and development drilling was down by 7%. The slowdown in Indonesia, the most active country for which data are available, was the main reason for the overall decline. In contrast, Brunei, Burma, Pakistan significantly increased their exploration drilling. Seismic activity in the region was up by 6%. A significant increase in marine seismic acquisition occurred in India, whereas Indonesia, Burma, and Brunei had a slowdown. As in themore » past, Indonesia maintained its role as the most active country in the region. No detailed exploration data were available for the People's Republic of China. The bulk of the exploration efforts in the region took place in relatively mature areas; frontier areas had a relatively low level of activity. There were no major oil or gas discoveries in the region, although Brunei, Burma, India, Indonesia, Malaysia, Pakistan, and Thailand had multiple successes in finding modest hydrocarbon reserves. Record acreage awards were made in Pakistan and Thailand, in contrast to Indonesia where awards were at the lowest level in recent years. A general increase of farm-out offering reflected the need to spread the risk of large exploration commitments. Production of both oil and gas increased significantly. Output of crude and condensate was up by 10% (an increase of 445,000 BOPD). A 21% increase was achieved in gas production, mainly due to expansions at Mobil's Arun and Huffcoi's Bontang LNG plants in North Sumatra and East Kalimantan, respectively. 31 figures, 9 tables.« less

Oil and gas developments in Far East in 1984

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

Soeparjadi, R.A.; Sosromihardjo, S.; Valachi, L.Z.

1985-10-01

In 1984, the Far East region was no exception to the general worldwide slowdown in petroleum activities, although exploration and production were maintained at relatively high rates. Exploratory drilling decreased by 14%, and development drilling was down by 7%. The slowdown in Indonesia, the most active country for which data are available, was the main reason for the overall decline. In contrast, Brunei, Burma, and Pakistan significantly increased their exploration drilling. Seismic activity in the region was up by 6%. A significant increase in marine seismic acquisition occurred in India, whereas Indonesia, Burma, and Brunei had a slowdown. As inmore » the past, Indonesia maintained its role as the most active country in the region. No detailed exploration data were available for the People's Republic of China. The bulk of the exploration efforts in the region took place in relatively mature areas; frontier areas had a relatively low level of activity. There were no major oil or gas discoveries in the region, although Brunei, Burma, India, Indonesia, Malaysia, Pakistan, and Thailand had multiple successes in finding modest hydrocarbon reserves. Record acreage awards were made in Pakistan and Thailand, in contrast to Indonesia where awards were at the lowest level in recent years. A general increase in farm-out offerings reflected the need to spread the risk of large exploration commitments. Production of both oil and gas increased significantly. Output of crude and condensate was up by 10% (an increase of 445,000 BOPD). A 21% increase was achieved in gas production, mainly due to expansions at Mobil's Arun and Huffco's Bontang LNG plants in North Sumatra and East Kalimantan, respectively.« less

Lung imaging in rodents using dual energy micro-CT

NASA Astrophysics Data System (ADS)

Badea, C. T.; Guo, X.; Clark, D.; Johnston, S. M.; Marshall, C.; Piantadosi, C.

2012-03-01

Dual energy CT imaging is expected to play a major role in the diagnostic arena as it provides material decomposition on an elemental basis. The purpose of this work is to investigate the use of dual energy micro-CT for the estimation of vascular, tissue, and air fractions in rodent lungs using a post-reconstruction three-material decomposition method. We have tested our method using both simulations and experimental work. Using simulations, we have estimated the accuracy limits of the decomposition for realistic micro-CT noise levels. Next, we performed experiments involving ex vivo lung imaging in which intact lungs were carefully removed from the thorax, were injected with an iodine-based contrast agent and inflated with air at different volume levels. Finally, we performed in vivo imaging studies in (n=5) C57BL/6 mice using fast prospective respiratory gating in endinspiration and end-expiration for three different levels of positive end-expiratory pressure (PEEP). Prior to imaging, mice were injected with a liposomal blood pool contrast agent. The mean accuracy values were for Air (95.5%), Blood (96%), and Tissue (92.4%). The absolute accuracy in determining all fraction materials was 94.6%. The minimum difference that we could detect in material fractions was 15%. As expected, an increase in PEEP levels for the living mouse resulted in statistically significant increases in air fractions at end-expiration, but no significant changes in end-inspiration. Our method has applicability in preclinical pulmonary studies where various physiological changes can occur as a result of genetic changes, lung disease, or drug effects.

Methyl farnesoate couples environmental changes to testicular development in the crab Carcinus maenas.

PubMed

Nagaraju, G P C; Borst, D W

2008-09-01

Carcinus maenas males have two major color phases. Green-phase males molt frequently and tend to live in brackish estuaries during the summer. After becoming red-phase males, they molt infrequently, have higher mating success, and live in cooler, deeper water. We found profound differences between these two phases in the way salinity and temperature affect hemolymph levels of methyl farnesoate (MF), a hormone that affects crustacean reproduction. Few green-phase males (<10%) had detectable MF in 33 ppt seawater (SW) at 11 or 18 degrees C. By contrast, about 30% of the red-phase males had detectable MF at either temperature. After transfer to 5 ppt SW, none of the green-phase males had detectable MF at 11 degrees C whereas 100% of green-phase males did at 18 degrees C. By contrast, 100% of the red-phase males had detectable MF in 5 ppt SW at either temperature. At 11 degrees C, green-phase males had detectable MF after eyestalk ablation (ESA), showing that they can produce MF. There was no additional increase in MF levels when ESA animals of either color phase were transferred to 5 ppt SW, suggesting that the eyestalk is the primary regulator of the MF response to low salinity. MF levels of green-phase males were increased by injecting MF, by ESA, or by exposure to 5 ppt SW at 18 degrees C. The testicular index of these treated animals nearly doubled after two weeks. Our results strongly suggest that environmental conditions such as temperature and salinity, affect testicular development in this crab by changing its MF levels.

[Diagnostic Significance of BAT in Anaphylaxis to Non-ionic Contrast Media].

PubMed

Zhang, Hao-yue; Xu, Su-jun; Tang, Xiao-xian; Niu, Ji-jun; Guo, Xiang-jie; Gao, Cai-rong

2015-06-01

To investigate the diagnostic significance of basophil activation test (BAT) in anaphylaxis to non-ionic contrast media through testing the content of CD63, mast cell-carboxypeptidase A3 (MC-CPA3), and terminal complement complex SC5b-9 of the individuals by testing their levels in the normal immune group and the anaphylaxis groups to β-lactam drugs and non -ionic contrast media. The CD63 expression of basophilic granulocyte in blood was detected by flow cytometry. The levels of MC-CPA3 in blood serum and SC5b-9 in blood plasma were detected by ELISA. The CD63 expression of basophilic granulocyte in blood, the levels of MC-CPA3 and SC5b-9 of anaphylaxis to non-ionic contrast media and β-lactam drugs were significantly higher than that in normal immune group (P < 0.05). There is activation of basophilic granulocytes, mast cells and complement system in anaphylaxis to non-ionic contrast media. BAT can be used to diagnose the anaphylaxis to non-ionic contrast media.

Method for Assessing Contrast Performance under Lighting Conditions such as Entering a Tunnel on Sunny Day.

PubMed

Huang, Y; Menozzi, M

2015-04-01

Clinical assessment of dark adaptation is time consuming and requires a specialised instrumentation such as a nyktometer. It is therefore not surprising that dark adaptation is rarely tested in practice. As for the case of testing fitness of a driver, demands on adaptation in daily driving tasks mostly depart from settings in a nyktometer. In daily driving, adaptation is stressed by high and fast transitions of light levels, and the period of time which is relevant to safe driving starts right after a transition and ends several seconds later. In the nyktometer dark adaptation is tested after completion of the adaptation process. RESULTS of a nyktometer test may therefore deliver little information about adaptation shortly after light transitions. In an attempt to develop a clinical test aiming to fulfill both a short measurement time and offering test conditions comparable to conditions in driving, we conducted a preliminary study in which contrast sensitivity thresholds were recorded for light transitions as found in daily driving tasks and for various times after transition onsets. Contrast sensitivity performance is compared to dark adaptation performance as assessed by a myktometer. Contrast sensitivity thresholds were recorded in 17 participants by means of a twin projection apparatus. The apparatus enabled the projection of an adapting field and of a Landolt ring both with a variable luminance. Five different stepwise transitions in levels of adapting luminance were tested. All transitions occurred from bright to dark. The Landolt ring was flashed 100 or 500 ms after the transition had occurred. Participants were instructed to report the orientation of the Landolt ring. A Rodenstock Nyktometer, Plate 501, was used to record dark adaptation threshold. Experimental data from the proposed test revealed a noticeably increasing contrast detection threshold measured in dark adaptation in the stronger transition from 14 000 to 8 cd/m2 than in the weaker transition from 2000 to 8 cd/m2. By raising the dark adaption luminance level from 8 to 60 cd/m2 in the stronger transition case, the contrast detection threshold was then improved by a factor of four. Another main finding showed that for the adaptation process from strong glare stimuli to the dark adaptation, a peak deterioration in contrast sensitivity occurred at the light adaptation level of 6000 cd/m2. Comparing the contrast performance assessed by the proposed test with that of the nyktometer test, there was no clear correlation between the two methods. Our suggested method to assess dark adaptation performance proved to be practical in use and, since the patient does not have to spend a long time to attain complete dark adaptation, the method required a short time for measurement. Our negative experience in the use of the myktometer was in agreement with reported experience in the literature. Georg Thieme Verlag KG Stuttgart · New York.

Tyrosine levels are associated with insulin resistance in patients with nonalcoholic fatty liver disease

PubMed Central

Kawanaka, Miwa; Nishino, Ken; Oka, Takahito; Urata, Noriyo; Nakamura, Jun; Suehiro, Mitsuhiko; Kawamoto, Hirofumi; Chiba, Yasutaka; Yamada, Gotaro

2015-01-01

Objective Amino acid imbalance is often found in patients with cirrhosis, and this imbalance is associated with insulin resistance. However, the mechanism underlying the relationship between amino acid imbalance and insulin resistance remains unclear. We evaluated serum amino acid concentrations in patients with nonalcoholic fatty liver disease to determine if any of the levels of amino acids were associated with the biochemical markers and fibrosis stage of nonalcoholic steatohepatitis (NASH). Methods In 137 patients with nonalcoholic fatty liver disease who underwent liver biopsy, plasma levels of branched-chain amino acid (BCAA), tyrosine (Tyr), and the BCAA-to-Tyr ratio values were determined using mass spectroscopy. These values were then assessed for associations with fibrosis stage, anthropometric markers (age, sex, and body mass index), biochemical markers (alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase, albumin, platelet count, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and glycosylated hemoglobin), and relevant disease-specific biomarkers (homeostasis model assessment of insulin resistance [HOMA-IR], serum iron, ferritin, leptin, adiponectin, high-sensitivity C-reactive protein, and hyaluronic acid). Results Serum albumin levels, plasma BCAA levels, and BCAA-to-Tyr ratio values were negatively associated with the fibrosis stage. In contrast, Tyr levels increased with increasing fibrotic staging. Tyr levels were also correlated with HOMA-IR results. Conclusion Plasma BCAA levels in patients with NASH decreased with increasing liver fibrosis, while Tyr levels increased with increasing fibrotic stage. These results suggest that amino acid imbalance and insulin resistance are intimately involved in a complex pathogenic mechanism for NASH. PMID:26082668

Imaging the cardiac blood flow during CPR with EBCT in an animal model

NASA Astrophysics Data System (ADS)

Recheis, Wolfgang A.; Schuster, Antonius H.; Pallwein-Prettner, Leo; Kleinsasser, Axel; Loeckinger, Alexander; Hoermann, Christoph; zur Nedden, Dieter

2002-04-01

There are open questions concerning the hemodynamics during cardiopulmonary resuscitation (CPR). The purpose was to evaluate a model of the blood flow during CPR in specified anatomic regions. After cardiac arrest, one intubated swine under full intensive care supervision was scanned during CPR using an automated resuscitation device. CT scans were performed with an EBCT in the 50ms modus at eight levels, therefore covering most of the heart and pulmonary vessels. 50ml contrast agent was administered with 10ml/sec and a delay of five seconds to visualize the contrast agent passage through the heart and pulmonary circulation. The gray-value changes in previously specified ROIs were directly correlated with the resuscitation device position in respect to the thorax. The effects of CPR on the blood flow could be visualized dynamically by quantifying the contrast enhancement. The increase of gray values could be estimated with different delays, depending on the anatomical situation. The inflow and outflow dependent on thumper dynamics could be estimated. At the onset of contrast medium inflow, turbulence could be visualized in the right ventricle, which are caused by the inhomogeneous contrast medium distribution. Triggered EBCT during CPR offers the opportunity to study regional blood flow depending on chest compression.

Endoscopic ultrasound for the characterization and staging of rectal cancer. Current state of the method. Technological advances and perspectives.

PubMed

Gersak, Mariana M; Badea, Radu; Graur, Florin; Hajja, Nadim Al; Furcea, Luminita; Dudea, Sorin M

2015-06-01

Endoscopic ultrasound is the most accurate type of examination for the assessment of rectal tumors. Over the years, the method has advanced from gray-scale examination to intravenous contrast media administration and to different types of elastography. The multimodal approach of tumors (transrectal, transvaginal) is adapted to each case. 3D ultrasound is useful for spatial representation and precise measurement of tumor formations, using CT/MR image reconstruction; color elastography is useful for tumor characterization and staging; endoscopic ultrasound using intravenous contrast agents can help study the amount of contrast agent targeted at the level of the tumor formations and contrast wash-in/wash-out time, based on the curves displayed on the device. The transvaginal approach often allows better visualization of the tumor than the transrectal approach. Performing the procedure with the rectal ampulla distended with contrast agent may be seen as an optimization of the examination methodology. All these aspects are additional methods for gray-scale endoscopic ultrasound, capable of increasing diagnostic accuracy. This paper aims at reviewing the progress of transrectal and transvaginal ultrasound, generically called endoscopic ultrasound, for rectal tumor diagnosis and staging, with emphasis on the current state of the method and its development trends.

Association Between Contrast Media Volume-Glomerular Filtration Rate Ratio and Contrast-Induced Acute Kidney Injury After Primary Percutaneous Coronary Intervention.

PubMed

Celik, Omer; Ozturk, Derya; Akin, Fatih; Ayca, Burak; Yalcın, Ahmet Arif; Erturk, Mehmet; Bıyık, Ismail; Ayaz, Ahmet; Akturk, Ibrahim Faruk; Enhos, Asım; Aslan, Serkan

2015-07-01

We hypothesized that contrast media volume-estimated glomerular filtration rate (CV-e-GFR) ratio may be a predictor of contrast media-induced acute kidney injury (CI-AKI). We investigated the associations between CV-e-GFR ratio and CI-AKI in 597 patients undergoing primary percutaneous coronary intervention (pPCI). An absolute ≥0.3 mg/dL increase in serum creatinine compared with baseline levels within 48 hours after the procedure was considered as CI-AKI; 78 (13.1%) of the 597 patients experienced CI-AKI. The amount of contrast during procedure was higher in the CI-AKI group than in those without CI-AKI (153 vs 135 mL, P = .003). The CV-e-GFR ratio was significantly higher in patients with CI-AKI than without (2.3 vs 1.5, P < .001). In multivariate analysis, independent predictors of CI-AKI were low left ventricular ejection fraction (P = .018, odds ratio [OR] = 0.966), e-GFR <60 mL/min (P = .012, OR = 2.558), and CV-e-GFR >2 (P < .001, OR = 5.917). In conclusion, CV-e-GFR ratio is significantly associated with CI-AKI after pPCI. © The Author(s) 2014.

Cadherin-11 Regulation of Fibrosis through Modulation of Epithelial-to-Mesenchymal Transition: Implications for Pulmonary Fibrosis in Scleroderma

DTIC Science & Technology

2013-10-01

4A, TGFbeta decreased E- cadherin expression and increase Col1a1 expression in MLE12 cells. Soluble Cad11 Fc fusion protein inhibited EMT induced by...TGFbeta as noted my higher E-cadherin levels and a significant reduction in Col1a1 mRNA. In contrast, when Cad11 Fc fusion protein was immobilized...Fc fusion protein alone was able to induce Col1a1 expression at the 50 ug/ml concentration, although E-cadherin expression was also increased. In

Protection from experimental asthma by an endogenous bronchodilator.

PubMed

Que, Loretta G; Liu, Limin; Yan, Yun; Whitehead, Gregory S; Gavett, Stephen H; Schwartz, David A; Stamler, Jonathan S

2005-06-10

Mechanisms that protect against asthma remain poorly understood. S-nitrosoglutathione (GSNO), an endogenous bronchodilator, is depleted from asthmatic airways, suggesting a protective role. We report that, following allergen challenge, wild-type mice exhibiting airway hyperresponsivity have increased airway levels of the enzyme GSNO reductase (GSNOR) and are depleted of lung S-nitrosothiols (SNOs). In contrast, mice with genetic deletion of GSNOR exhibit increases in lung SNOs and are protected from airway hyperresponsivity. Our results indicate that endogenous SNOs, governed by GSNOR, are critical regulators of airway responsivity and may provide new therapeutic approaches to asthma.

Characterization of a new generation of computed radiography system based on line scanning and phosphor needles

NASA Astrophysics Data System (ADS)

Dragusin, Octavian; Rogge, Frank; Pauwels, Herman; Marchal, Guy; Bosmans, Hilde

2006-03-01

A new generation CR system that is based on phosphor needles and that uses a digitizer with line scan technology was compared to a clinically used CR system. Purely technical and more clinically related tests were run on both systems. This included the calculation of the DQE, signal-to-noise and contrast to noise ratios from Aluminum inserts, contrast detail analysis with the CDRAD phantom and the use of anthropomorphic phantoms (wrist, chest and skull) with scoring by a radiologist. X-ray exposures with various dose levels and 50kV, 70kV and 125kV were acquired. For detector doses above 0.8 μGy, all noise related measurements showed the superiority of the new technology. The MTF confirmed the improvement in sharpness: between 1 and 3 lp/mm increases ranged from 20 to 50%. Further work should be devoted to the determination of the required dose levels in the plate for the different radiological applications.

The hemodynamics in intracranial aneurysm ruptured region with active contrast leakage during computed tomography angiography

NASA Astrophysics Data System (ADS)

Li, Ming-Lung; Wang, Yi-Chou; Liou, Tong-Miin; Lin, Chao-An

2014-10-01

Precise locations of rupture region under contrast agent leakage of five ruptured cerebral artery aneurysms during computed tomography angiography, which is to our knowledge for the first time, were successfully identified among 101 patients. These, together with numerical simulations based on the reconstructed aneurysmal models, were used to analyze hemodynamic parameters of aneurysms under different cardiac cyclic flow rates. For side wall type aneurysms, different inlet flow rates have mild influences on the shear stresses distributions. On the other hand, for branch type aneurysms, the predicted wall shear stress (WSS) correlates strongly with the increase of inlet vessel velocity. The mean and time averaged WSSes at rupture regions are found to be lower than those over the surface of the aneurysms. Also, the levels of the oscillatory shear index (OSI) are higher than the reported threshold value, supporting the assertion that high OSI correlates with rupture of the aneurysm. However, the present results also indicate that OSI level at the rupture region is relatively lower.

Temperature Regulation of Endogenous Gibberellin Activity and Development of Tulipa gesneriana L. 1

PubMed Central

Aung, L. H.; De Hertogh, A. A.; Staby, G.

1969-01-01

The changes in the contents of free and bound gibberellin-like activity (GA) of Tulipa gesneriana L. cv. Ralph during development under 2 temperature conditions were studied. The results show that the content of free GA of bulbs grown at 18° increased by 67% over the initial level during development. The bound GA showed a slight initial increase and was followed by a rapid decrease. In contrast, bulbs treated at 13° showed a marked decline in free GA and a 2-fold increase in the content of bound GA. However, after the transfer of these bulbs from 13° to 18° the free GA increased to the initial level while the bound GA decreased to a low level. The rate of floral shoot and root development and time of flowering were accelerated at 18° as compared to 13°. From the data obtained, it was suggested that a temperature-sensitive interconversion mechanism between free and bound GA exists in tulip bulbs and that there is apparent synthesis or transformation of these phytohormones during development of the bulbs. PMID:16657075

Ecophysiological response of native and exotic salt marsh vegetation to waterlogging and salinity: Implications for the effects of sea-level rise.

PubMed

Li, Shi-Hua; Ge, Zhen-Ming; Xie, Li-Na; Chen, Wei; Yuan, Lin; Wang, Dong-Qi; Li, Xiu-Zhen; Zhang, Li-Quan

2018-02-05

The ecophysiological characteristics of native Phragmites australis and exotic Spartina alterniflora grown under waterlogging and salinity were investigated to explore their adaptation potential to sea level rise. The seasonal course of phenotypic traits, photosynthetic activity and chlorophyll fluorescence parameters of P. australis did not change remarkably under shallow flooding, whereas these variables were sensitive to increasing salinity. Waterlogging exacerbated the negative effects of salinity on shoot growth and photosynthetic activity of P. australis, and the combined stresses led to an absence of tassel and reproductive organs. By contrast, S. alterniflora performed well under both stresses and showed an obvious adaptation of salt secretion with increasing salinity. Light salinity was the optimal condition for S. alterniflora, and the tassel growth, chlorophyll content and fluorescence characters under moderate stresses did not differ notably. The Na + and Cl - concentrations in leaves of both species increased, and the K + content decreased in response to salinity. Under moderate and high saline levels, the ion concentrations in S. alterniflora were maintained at relatively consistent levels with increased salt secretion. We expect the degradation of P. australis and further colonization of S. alterniflora under prolonged flooding and saltwater intrusion from sea level rise on the coastline of China.

The effect of cellobiose on the health status of growing rabbits depends on the dietary level of soluble fiber.

PubMed

Ocasio-Vega, César; Delgado, Rebeca; Abad-Guamán, Rodrigo; Carabaño, Rosa; Carro, Maria Dolores; Menoyo, David; García, Javier

2018-05-04

The aim of this study was to examine whether the combination of dietary soluble fiber and cellobiose exerts a synergistic effect on growth performance, health status, fermentation traits, and immune response in rabbits. Six treatments in a 3 × 2 factorial arrangement were used: 3 cellobiose concentrations in drinking water (0.0, 7.5, and 15.0 g/L) × 2 dietary levels of soluble fiber (84.0 and 130 g/kg DM, for the low soluble fiber [LSF] and high soluble fiber [HSF] diets, respectively). A total of 318 young rabbits (53/treatment) were weaned at 34 d of age and had ad libitum access to feed and water. At 46 d of age, 9 rabbits/treatment were slaughtered and ileal and cecal digesta were collected to analyze VFA profile and the immune response in the cecal appendix mucosa. At 48 d of age, the cellobiose supplementation was withdrawn and the experimental diets were replaced by a standard commercial diet until 61 d of age. From 34 to 48 d of age, there was a linear increase of mortality with the level of cellobiose in the HSF group (0% vs. 17.1%; P = 0.017). In contrast, a quadratic effect of cellobiose level on mortality was observed in the LSF group, the rabbits offered 7.5-cellobiose showing the lowest mortality (5.7% vs. 21.4%; P = 0.030). Cellobiose level had a quadratic effect on ADFI, ADG, and G:F in this period (P ≤ 0.047), with the 7.5-cellobiose groups having the best growth performance. In contrast, only minor changes on these traits were observed from 48 d of age onwards. Cellobiose level influenced quadratically the ileal VFA concentrations (P = 0.014), showing the maximal value in the 7.5-cellobiose groups. In rabbits fed 7.5-cellobiose-LSF, a change of acetate to propionate, butyrate, and valerate was observed in the ileum. Increasing cellobiose levels reduced linearly cecal VFA concentrations in HSF fed rabbits, but no effect was detected in LSF groups (P = 0.046). The level of soluble fiber increased VFA concentrations in both the ileum (by 22%; P < 0.001), and the cecum (by 11%; P = 0.005). The relative gene expression of IL-6, IL-10, TNF-α, iNOS, MUC-1, and toll-like receptors (TLR-2 and TLR-4) in the cecal appendix increased linear and quadratically with increasing levels of cellobiose (P ≤ 0.063). In conclusion, in rabbits fed LSF diets, a dose of 7.5 g cellobiose/L drinking water would be recommended, whereas these levels of cellobiose supplementation should be avoided in rabbits fed HSF diets.

Measurement of peak CSF flow velocity at cerebral aqueduct, before and after lumbar CSF drainage, by use of phase-contrast MRI: utility in the management of idiopathic normal pressure hydrocephalus.

PubMed

Sharma, Ashwani Kumar; Gaikwad, Shailesh; Gupta, Vipul; Garg, Ajay; Mishra, Nalini K

2008-04-01

Since it was first described, normal pressure hydrocephalus (NPH) and its treatment by means of cerebrospinal fluid (CSF) shunting have been the focus of much investigation. Whatever be the cause of NPH, it has been hypothesized that in this disease there occurs decreased arterial expansion and an increased brain expansion leading to increased transmantle pressure. We cannot measure the latter, but fortunately the effect of these changes (increased peak flow velocity through the aqueduct) can be quantified with cine phase-contrast magnetic resonance imaging (MRI). This investigation was thus undertaken to characterize and measure CSF peak flow velocity at the level of the aqueduct, before and after lumbar CSF drainage, by means of a phase-contrast cine MRI and determine its role in selecting cases for shunt surgery. 37 patients with clinically suspected NPH were included in the study. Changes in the hyperdynamic peak CSF flow velocity with 50 ml lumbar CSF drainage (mimicking shunt) were evaluated in them for considering shunt surgery. 14 out of 15 patients who were recommended for shunt surgery, based on changes peak flow velocity after lumbar CSF drainage, improved after shunt surgery. None of the cases which were not recommended for shunt surgery, based on changes in CSF peak flow velocity after lumbar CSF drainage, improved after shunt surgery (2 out of 22 cases). The study concluded that the phase-contrast MR imaging, done before and after CSF drainage, is a sensitive method to support the clinical diagnosis of normal pressure hydrocephalus, selecting patients of NPH who are likely to benefit from shunt surgery, and to select patients of NPH who are not likely to benefit from shunt surgery.

Functional Magnetic Resonance Imaging to Assess the Neurobehavioral Impact of Dysphotopsia with Multifocal Intraocular Lenses.

PubMed

Rosa, Andreia M; Miranda, Ângela C; Patrício, Miguel; McAlinden, Colm; Silva, Fátima L; Murta, Joaquim N; Castelo-Branco, Miguel

2017-09-01

To investigate the association between dysphotopsia and neural responses in visual and higher-level cortical regions in patients who recently received multifocal intraocular lens (IOL) implants. Cross-sectional study. Thirty patients 3 to 4 weeks after bilateral cataract surgery with diffractive IOL implantation and 15 age- and gender-matched control subjects. Functional magnetic resonance imaging (fMRI) was performed when participants viewed low-contrast grating stimuli. A light source surrounded the stimuli in half of the runs to induce disability glare. Visual acuity, wavefront analysis, Quality of Vision (QoV) questionnaire, and psychophysical assessment were performed. Cortical activity (blood oxygen level dependent [BOLD] signal) in the primary visual cortex and in higher-level brain areas, including the attention network. When viewing low-contrast stimuli under glare, patients showed significant activation of the effort-related attention network in the early postoperative period, involving the frontal, middle frontal, parietal frontal, and postcentral gyrus (multisubject random-effects general linear model (GLM), P < 0.03). In contrast, controls showed only relative deactivation (due to lower visibility) of visual areas (occipital lobe and middle occipital gyrus, P < 0.03). Patients also had relatively stronger recruitment of cortical areas involved in learning (anterior cingulate gyrus), task planning, and solving (caudate body). Patients reporting greater symptoms induced by dysphotic symptoms showed significantly increased activity in several regions in frontoparietal circuits, as well as cingulate gyrus and caudate nucleus (q < 0.05). We found no correlation between QoV questionnaire scores and optical properties (total and higher order aberration, modulation transfer function, and Strehl ratio). This study shows the association between patient-reported subjective difficulties and fMRI outcomes, independent of optical parameters and psychophysical performance. The increased activity of cortical areas dedicated to attention (frontoparietal circuits), to learning and cognitive control (cingulate), and to task goals (caudate) likely represents the beginning of the neuroadaptation process to multifocal IOLs. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Methylphenidate attenuates limbic brain inhibition after cocaine-cues exposure in cocaine abusers.

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

Volkow, N.D.; Wang, G.; Volkow, N.D.

Dopamine (phasic release) is implicated in conditioned responses. Imaging studies in cocaine abusers show decreases in striatal dopamine levels, which we hypothesize may enhance conditioned responses since tonic dopamine levels modulate phasic dopamine release. To test this we assessed the effects of increasing tonic dopamine levels (using oral methylphenidate) on brain activation induced by cocaine-cues in cocaine abusers. Brain metabolism (marker of brain function) was measured with PET and {sup 18}FDG in 24 active cocaine abusers tested four times; twice watching a Neutral video (nature scenes) and twice watching a Cocaine-cues video; each video was preceded once by placebo andmore » once by methylphenidate (20 mg). The Cocaine-cues video increased craving to the same extent with placebo (68%) and with methylphenidate (64%). In contrast, SPM analysis of metabolic images revealed that differences between Neutral versus Cocaine-cues conditions were greater with placebo than methylphenidate; whereas with placebo the Cocaine-cues decreased metabolism (p<0.005) in left limbic regions (insula, orbitofrontal, accumbens) and right parahippocampus, with methylphenidate it only decreased in auditory and visual regions, which also occurred with placebo. Decreases in metabolism in these regions were not associated with craving; in contrast the voxel-wise SPM analysis identified significant correlations with craving in anterior orbitofrontal cortex (p<0.005), amygdala, striatum and middle insula (p<0.05). This suggests that methylphenidate's attenuation of brain reactivity to Cocaine-cues is distinct from that involved in craving. Cocaine-cues decreased metabolism in limbic regions (reflects activity over 30 minutes), which contrasts with activations reported by fMRI studies (reflects activity over 2-5 minutes) that may reflect long-lasting limbic inhibition following activation. Studies to evaluate the clinical significance of methylphenidate's blunting of cue-induced limbic inhibition may help identify potential benefits of this medication in cocaine addiction.« less

Methylphenidate Attenuates Limbic Brain Inhibition after Cocaine-Cues Exposure in Cocaine Abusers

PubMed Central

Volkow, Nora D.; Wang, Gene-Jack; Tomasi, Dardo; Telang, Frank; Fowler, Joanna S.; Pradhan, Kith; Jayne, Millard; Logan, Jean; Goldstein, Rita Z.; Alia-Klein, Nelly; Wong, Christopher

2010-01-01

Dopamine (phasic release) is implicated in conditioned responses. Imaging studies in cocaine abusers show decreases in striatal dopamine levels, which we hypothesize may enhance conditioned responses since tonic dopamine levels modulate phasic dopamine release. To test this we assessed the effects of increasing tonic dopamine levels (using oral methylphenidate) on brain activation induced by cocaine-cues in cocaine abusers. Brain metabolism (marker of brain function) was measured with PET and 18FDG in 24 active cocaine abusers tested four times; twice watching a Neutral video (nature scenes) and twice watching a Cocaine-cues video; each video was preceded once by placebo and once by methylphenidate (20 mg). The Cocaine-cues video increased craving to the same extent with placebo (68%) and with methylphenidate (64%). In contrast, SPM analysis of metabolic images revealed that differences between Neutral versus Cocaine-cues conditions were greater with placebo than methylphenidate; whereas with placebo the Cocaine-cues decreased metabolism (p<0.005) in left limbic regions (insula, orbitofrontal, accumbens) and right parahippocampus, with methylphenidate it only decreased in auditory and visual regions, which also occurred with placebo. Decreases in metabolism in these regions were not associated with craving; in contrast the voxel-wise SPM analysis identified significant correlations with craving in anterior orbitofrontal cortex (p<0.005), amygdala, striatum and middle insula (p<0.05). This suggests that methylphenidate's attenuation of brain reactivity to Cocaine-cues is distinct from that involved in craving. Cocaine-cues decreased metabolism in limbic regions (reflects activity over 30 minutes), which contrasts with activations reported by fMRI studies (reflects activity over 2–5 minutes) that may reflect long-lasting limbic inhibition following activation. Studies to evaluate the clinical significance of methylphenidate's blunting of cue-induced limbic inhibition may help identify potential benefits of this medication in cocaine addiction. PMID:20634975

Contrasting medial moraine development at adjacent temperate, maritime glaciers: Fox and Franz Josef Glaciers, South Westland, New Zealand

NASA Astrophysics Data System (ADS)

Brook, Martin; Hagg, Wilfried; Winkler, Stefan

2017-08-01

Medial moraines form important pathways for sediment transportation in valley glaciers. Despite the existence of well-defined medial moraines on several glaciers in the New Zealand Southern Alps, medial moraines there have hitherto escaped attention. The evolving morphology and debris content of medial moraines on Franz Josef Glacier and Fox Glacier on the western flank of the Southern Alps is the focus of this study. These temperate maritime glaciers exhibit accumulation zones of multiple basins that feed narrow tongues flowing down steep valleys and terminate 400 m above sea level. The medial moraines at both glaciers become very prominent in the lower ablation zones, where the medial moraines widen, and develop steeper flanks coeval with an increase in relative relief. Medial moraine growth appears somewhat self-limiting in that relief and slope angle increase eventually lead to transport of debris away from the medial moraine by mass-movement-related processes. Despite similarities in overall morphologies, a key contrast in medial moraine formation exists between the two glaciers. At Fox Glacier, the medial moraine consists of angular rockfall-derived debris, folded to varying degrees along flow-parallel axes throughout the tongue. The debris originates above the ELA, coalesces at flow-unit boundaries, and takes a medium/high level transport pathway before subsequently emerging at point-sources aligned with gently dipping fold hinges near the snout. In contrast at Franz Josef Glacier, the medial moraine emerges farther down-glacier immediately below a prominent rock knob. Clasts show a mix of angular to rounded shapes representing high level transport and subglacially transported materials, the latter facies possibly also elevated by supraglacial routing of subglacial meltwater. Our observations confirm that a variety of different debris sources, transport pathways, and structural glaciological processes can interact to form medial moraines within New Zealand's Southern Alps.

The Nature of Exposure Drives Transmission of Nipah Viruses from Malaysia and Bangladesh in Ferrets

PubMed Central

Clayton, Bronwyn A.; Middleton, Deborah; Arkinstall, Rachel; Frazer, Leah; Wang, Lin-Fa; Marsh, Glenn A.

2016-01-01

Person-to-person transmission is a key feature of human Nipah virus outbreaks in Bangladesh. In contrast, in an outbreak of Nipah virus in Malaysia, people acquired infections from pigs. It is not known whether this important epidemiological difference is driven primarily by differences between NiV Bangladesh (NiV-BD) and Malaysia (NiV-MY) at a virus level, or by environmental or host factors. In a time course study, ferrets were oronasally exposed to equivalent doses of NiV-BD or NiV-MY. More rapid onset of productive infection and higher levels of virus replication in respiratory tract tissues were seen for NiV-BD compared to NiV-MY, corroborating our previous report of increased oral shedding of NiV-BD in ferrets and suggesting a contributory mechanism for increased NiV-BD transmission between people compared to NiV-MY. However, we recognize that transmission occurs within a social and environmental framework that may have an important and differentiating role in NiV transmission rates. With this in mind, ferret-to-ferret transmission of NiV-BD and NiV-MY was assessed under differing viral exposure conditions. Transmission was not identified for either virus when naïve ferrets were cohoused with experimentally-infected animals. In contrast, all naïve ferrets developed acute infection following assisted and direct exposure to oronasal fluid from animals that were shedding either NiV-BD or NiV-MY. Our findings for ferrets indicate that, although NiV-BD may be shed at higher levels than NiV-MY, transmission risk may be equivalently low under exposure conditions provided by cohabitation alone. In contrast, active transfer of infected bodily fluids consistently results in transmission, regardless of the virus strain. These observations suggest that the risk of NiV transmission is underpinned by social and environmental factors, and will have practical implications for managing transmission risk during outbreaks of human disease. PMID:27341030

The Nature of Exposure Drives Transmission of Nipah Viruses from Malaysia and Bangladesh in Ferrets.

PubMed

Clayton, Bronwyn A; Middleton, Deborah; Arkinstall, Rachel; Frazer, Leah; Wang, Lin-Fa; Marsh, Glenn A

2016-06-01

Person-to-person transmission is a key feature of human Nipah virus outbreaks in Bangladesh. In contrast, in an outbreak of Nipah virus in Malaysia, people acquired infections from pigs. It is not known whether this important epidemiological difference is driven primarily by differences between NiV Bangladesh (NiV-BD) and Malaysia (NiV-MY) at a virus level, or by environmental or host factors. In a time course study, ferrets were oronasally exposed to equivalent doses of NiV-BD or NiV-MY. More rapid onset of productive infection and higher levels of virus replication in respiratory tract tissues were seen for NiV-BD compared to NiV-MY, corroborating our previous report of increased oral shedding of NiV-BD in ferrets and suggesting a contributory mechanism for increased NiV-BD transmission between people compared to NiV-MY. However, we recognize that transmission occurs within a social and environmental framework that may have an important and differentiating role in NiV transmission rates. With this in mind, ferret-to-ferret transmission of NiV-BD and NiV-MY was assessed under differing viral exposure conditions. Transmission was not identified for either virus when naïve ferrets were cohoused with experimentally-infected animals. In contrast, all naïve ferrets developed acute infection following assisted and direct exposure to oronasal fluid from animals that were shedding either NiV-BD or NiV-MY. Our findings for ferrets indicate that, although NiV-BD may be shed at higher levels than NiV-MY, transmission risk may be equivalently low under exposure conditions provided by cohabitation alone. In contrast, active transfer of infected bodily fluids consistently results in transmission, regardless of the virus strain. These observations suggest that the risk of NiV transmission is underpinned by social and environmental factors, and will have practical implications for managing transmission risk during outbreaks of human disease.

Observations Of General Learning Patterns In An Upper-Level Thermal Physics Course

NASA Astrophysics Data System (ADS)

Meltzer, David E.

2009-11-01

I discuss some observations from using interactive-engagement instructional methods in an upper-level thermal physics course over a two-year period. From the standpoint of the subject matter knowledge of the upper-level students, there was a striking persistence of common learning difficulties previously observed in students enrolled in the introductory course, accompanied, however, by some notable contrasts between the groups. More broadly, I comment on comparisons and contrasts regarding general pedagogical issues among different student sub-populations, for example: differences in the receptivity of lower- and upper-level students to diagrammatic representations; varying receptivity to tutorial-style instructional approach within the upper-level population; and contrasting approaches to learning among physics and engineering sub-populations in the upper-level course with regard to use of symbolic notation, mathematical equations, and readiness to employ verbal explanations.

Stepwise emergence of the face-sensitive N170 event-related potential component.

PubMed

Jemel, Boutheina; Schuller, Anne-Marie; Cheref-Khan, Yasémine; Goffaux, Valérie; Crommelinck, Marc; Bruyer, Raymond

2003-11-14

The present study used a parametric design to characterize early event-related potentials (ERP) to face stimuli embedded in gradually decreasing random noise levels. For both N170 and the vertex positive potential (VPP) there was a linear increase in amplitude and decrease in latency with decreasing levels of noise. In contrast, the earlier visual P1 component was stable across noise levels. The P1/N170 dissociation suggests not only a functional dissociation between low and high-level visual processing of faces but also that the N170 reflects the integration of sensorial information into a unitary representation. In addition, the N170/VPP association supports the view that they reflect the same processes operating when viewing faces.

Can spectro-temporal complexity explain the autistic pattern of performance on auditory tasks?

PubMed

Samson, Fabienne; Mottron, Laurent; Jemel, Boutheina; Belin, Pascal; Ciocca, Valter

2006-01-01

To test the hypothesis that level of neural complexity explain the relative level of performance and brain activity in autistic individuals, available behavioural, ERP and imaging findings related to the perception of increasingly complex auditory material under various processing tasks in autism were reviewed. Tasks involving simple material (pure tones) and/or low-level operations (detection, labelling, chord disembedding, detection of pitch changes) show a superior level of performance and shorter ERP latencies. In contrast, tasks involving spectrally- and temporally-dynamic material and/or complex operations (evaluation, attention) are poorly performed by autistics, or generate inferior ERP activity or brain activation. Neural complexity required to perform auditory tasks may therefore explain pattern of performance and activation of autistic individuals during auditory tasks.

Air pollution: a tale of two countries.

PubMed

Haryanto, Budi; Franklin, Peter

2011-01-01

The fast growing economies and continued urbanization in Asian countries have increased the demand for mobility and energy in the region, resulting in high levels of air pollution in cities from mobile and stationary sources. In contrast, low level of urbanization in Australia produces low level of urban air pollution. The World Health Organization estimates that about 500,000 premature deaths per year are caused by air pollution, leaving the urban poor particularly vulnerable since they live in air pollution hotspots, have low respiratory resistance due to bad nutrition, and lack access to quality health care. Identifying the differences and similarities of air pollution levels and its impacts, between Indonesia and Australia, will provide best lesson learned to tackle air pollution problems for Pacific Basin Rim countries.

Detecting Climate Signals in Precipitation Extremes from TRMM (1998-2013) - Increasing Contrast Between Wet and Dry Extremes During the "Global Warming Hiatus"

NASA Technical Reports Server (NTRS)

Wu, Huey-Tzu Jenny; Lau, William K.-M.

2016-01-01

We investigate changes in daily precipitation extremes using Tropical Rainfall Measuring Mission (TRMM) data (1998-2013), which coincides with the "global warming hiatus." Results show a change in probability distribution functions of local precipitation events (LPEs) during this period consistent with previous global warming studies, indicating increasing contrast between wet and dry extremes, with more intense LPE, less moderate LPE, and more dry (no rain) days globally. Analyses for land and ocean separately reveal more complex and nuanced changes over land, characterized by a strong positive trend (+12.0% per decade, 99% confidence level (c.l.)) in frequency of extreme LPEs over the Northern Hemisphere extratropics during the wet season but a negative global trend (-6.6% per decade, 95% c.l.) during the dry season. A significant global drying trend (3.2% per decade, 99% c.l.) over land is also found during the dry season. Regions of pronounced increased dry events include western and central U.S., northeastern Asia, and Southern Europe/Mediterranean.

Alteration of Hormonal Levels in a Rootless Epiphytic Bromeliad in Different Phenological Phases.

PubMed

Mercier; Endres

1999-11-01

Major changes in indole-3-acetic acid (IAA) and cytokinin (CK) levels occur at different phenological phases of Tillandsia recurvata shoots. This epiphytic rootless bromeliad was chosen as suitable material for hormonal analysis because CK synthesis is restricted to the shoots, thus avoiding problems in the interpretation of results caused by translocation and interconversion of CK forms between roots and leaves encountered in plants with both organs. Young plants of T. recurvata have weak apical dominance because side shoots appeared early in development, and branch growth was correlated with a strong increase in the level of zeatin. The flowering phase was characterized by a significant increase in free base CKs, zeatin, and isopentenyladenine compared with the levels found in adult vegetative shoots. In contrast, both free-base CKs declined in the fruiting phenological phase, and the IAA level increased dramatically. It was concluded that in phases characterized by intense organ formation, such as in the juvenile and flowering stages, there was an enhancement of CK content, mainly caused by zeatin, leading to a lower IAA/CK ratio. Higher ratios were correlated with phases that showed no organogenesis, such as adult and fruiting phenologies.

Contrasted Reactivity to Oxygen Tensions in Frankia sp. Strain CcI3 throughout Nitrogen Fixation and Assimilation

PubMed Central

Ghodhbane-Gtari, Faten; Hezbri, Karima; Ktari, Amir; Sbissi, Imed; Beauchemin, Nicholas; Gtari, Maher; Tisa, Louis S.

2014-01-01

Reconciling the irreconcilable is a primary struggle in aerobic nitrogen-fixing bacteria. Although nitrogenase is oxygen and reactive oxygen species-labile, oxygen tension is required to sustain respiration. In the nitrogen-fixing Frankia, various strategies have been developed through evolution to control the respiration and nitrogen-fixation balance. Here, we assessed the effect of different oxygen tensions on Frankia sp. strain CcI3 growth, vesicle production, and gene expression under different oxygen tensions. Both biomass and vesicle production were correlated with elevated oxygen levels under both nitrogen-replete and nitrogen-deficient conditions. The mRNA levels for the nitrogenase structural genes (nifHDK) were high under hypoxic and hyperoxic conditions compared to oxic conditions. The mRNA level for the hopanoid biosynthesis genes (sqhC and hpnC) was also elevated under hyperoxic conditions suggesting an increase in the vesicle envelope. Under nitrogen-deficient conditions, the hup2 mRNA levels increased with hyperoxic environment, while hup1 mRNA levels remained relatively constant. Taken together, these results indicate that Frankia protects nitrogenase by the use of multiple mechanisms including the vesicle-hopanoid barrier and increased respiratory protection. PMID:24987692

Brain magnetic resonance imaging with contrast dependent on blood oxygenation

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

Ogawa, S.; Lee, T.M.; Kay, A.R.

1990-12-01

Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high yields, the authors demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normalmore » physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complement other techniques that are attempting to provide position emission tomography-like measurements related to regional neural activity.« less

Brain Magnetic Resonance Imaging with Contrast Dependent on Blood Oxygenation

NASA Astrophysics Data System (ADS)

Ogawa, S.; Lee, T. M.; Kay, A. R.; Tank, D. W.

1990-12-01

Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high fields, we demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normal physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complements other techniques that are attempting to provide positron emission tomography-like measurements related to regional neural activity.

Mechanism of insulin-stimulated clearance of plasma nonesterified fatty acids in humans.

PubMed

Carpentier, André C; Frisch, Frédérique; Brassard, Pascal; Lavoie, François; Bourbonnais, Annie; Cyr, Denis; Giguère, Robert; Baillargeon, Jean-Patrice

2007-03-01

Insulin increases plasma nonesterified fatty acid (NEFA) clearance in humans, but whether this is independent of change in plasma NEFA appearance is currently unknown. Nine nondiabetic men (age: 28+/-3 yr, body mass index: 27.2+/-1.7 kg/m2) underwent euglycemic clamps to maintain low (LINS) vs. high (HINS) physiological insulin levels for 6 h. An intravenous infusion of heparin+Intralipid (HI) was performed during 4 of the 6 h of the clamps (in the last 4 h at LINS and in the first 4 h at HINS), whereas saline infusion (SAL) was administered in the remaining 2 h to modulate plasma NEFA levels independently of plasma insulin levels. Four experimental conditions were obtained in each individual: LINS with saline (LINS/SAL) and with HI infusion (LINS/HI) and HINS with saline (HINS/SAL) and with HI infusion (HINS/HI). Plasma palmitate appearance during HINS/SAL was lower than during the three other experimental conditions (P<0.05). In contrast, plasma linoleate appearance, as expected, was increased by HI independently of insulin level (P<0.02). Plasma palmitate clearance during HINS/SAL was higher than LINS/SAL and LINS/HI (P<0.008), and this increase was blunted during HINS/HI. We observed a linear decrease in plasma palmitate clearance with increasing plasma NEFA appearance independent of insulin levels. Plasma NEFA levels increased exponentially with increase in plasma NEFA appearance. We conclude that insulin stimulates plasma NEFA clearance by reducing the endogenous appearance rate of NEFA. The relationship between plasma NEFA level and appearance rate is nonlinear.

Calibrating the response to health warnings: limiting both overreaction and underreaction with self-affirmation.

PubMed

Griffin, Dale W; Harris, Peter R

2011-05-01

Self-affirmation, reflecting on one's defining personal values, increases acceptance of threatening information, but does it do so at the cost of inducing undue alarm in people at low risk of harm? We contrast an alarm model, wherein self-affirmation simply increases response to threat, with a calibration model, wherein self-affirmation increases sensitivity to the self-relevance of health-risk information. Female seafood consumers (N = 165) completed a values self-affirmation or control task before reading a U.S. Food and Drug Administration brochure on mercury in seafood. Findings support the calibration model: Among frequent seafood consumers, self-affirmation generally increased concern (reports of depth of thought, personal message relevance, perceived risk, and negative affect) for those high in defensiveness and reduced it for those low in defensiveness. Among infrequent consumers of seafood, self-affirmation typically reduced concern. Thus, self-affirmation increased the sensitivity with which women at different levels of risk, and at different levels of defensiveness, responded cognitively and affectively to the materials.

Enhanced performance configuration for fast-switching deformed helix ferroelectric liquid crystal continuous tunable Lyot filter.

PubMed

Tam, A M W; Qi, G; Srivastava, A K; Wang, X Q; Fan, F; Chigrinov, V G; Kwok, H S

2014-06-10

In this paper, we present a novel design configuration of double DHFLC wave plate continuous tunable Lyot filter, which exhibits a rapid response time of 185 μs, while the high-contrast ratio between the passband and stop band is maintained throughout a wide tunable range. A DHFLC tunable filter with a high-contrast ratio is attractive for realizing high-speed optical processing devices, such as multispectral and hyperspectral imaging systems, real-time remote sensing, field sequential color display, and wavelength demultiplexing in the metro network. In this work, an experimental prototype for a single-stage DHFLC Lyot filter of this design has been fabricated using photoalignment technology. We have demonstrated that the filter has a continuous tunable range of 30 nm for a blue wavelength, 45 nm for a green wavelength, and more than 50 nm for a red wavelength when the applied voltage gradually increases from 0 to 8 V. Within this tunable range, the contrast ratio of the proposed double wave plate configuration is maintained above 20 with small deviation in the transmittance level. Simulation and experimental results showed the proposed double DHFLC wave plate configuration enhances the contrast ratio of the tunable filter and, thus, increases the tunable range of the filter when compared with the Lyot filter using a single DHFLC wave plate. Moreover, we have proposed a polarization insensitive configuration for which the efficiency of the existing prototype can theoretically be doubled by the use of polarization beam splitters.

Differential effects of voluntary and forced exercise on stress responses after traumatic brain injury.

PubMed

Griesbach, Grace S; Tio, Delia L; Vincelli, Jennifer; McArthur, David L; Taylor, Anna N

2012-05-01

Voluntary exercise increases levels of brain-derived neurotrophic factor (BDNF) after traumatic brain injury (TBI) when it occurs during a delayed time window. In contrast, acute post-TBI exercise does not increase BDNF. It is well known that increases in glucocorticoids suppress levels of BDNF. Moreover, recent work from our laboratory showed that there is a heightened stress response after fluid percussion injury (FPI). In order to determine if a heightened stress response is also observed with acute exercise, at post-injury days 0-4 and 7-11, corticosterone (CORT) and adrenocorticotropic hormone (ACTH) release were measured in rats running voluntarily or exposed to two daily 20-min periods of forced running wheel exercise. Forced, but not voluntary exercise, continuously elevated CORT. ACTH levels were initially elevated with forced exercise, but decreased by post-injury day 7 in the control, but not the FPI animals. As previously reported, voluntary exercise did not increase BDNF in the FPI group as it did in the control animals. Forced exercise did not increase levels of BDNF in any group. It did, however, decrease hippocampal glucocorticoid receptors in the control group. The results suggest that exercise regimens with strong stress responses may not be beneficial during the early post-injury period.

Papers and Studies in Contrastive Linguistics, Volume Twenty-Two. The Polish-English Contrastive Project.

ERIC Educational Resources Information Center

Fisiak, Jacek, Ed.

1988-01-01

Fifteen articles are presented in this collection on contrastive linguistics: "On Syntactic Levels--One Tertium Comparison is in Contrastive Linguistics" (L. F. Jakobsen and J. Olsen); "Equivalence in Bilingual Lexicography: From Correspondence Relation to Communicative Strategy" (R. R. K. Hartmann); "How Useful Are Word…

A comparison between temporal and subband minimum variance adaptive beamforming

NASA Astrophysics Data System (ADS)

Diamantis, Konstantinos; Voxen, Iben H.; Greenaway, Alan H.; Anderson, Tom; Jensen, Jørgen A.; Sboros, Vassilis

2014-03-01

This paper compares the performance between temporal and subband Minimum Variance (MV) beamformers for medical ultrasound imaging. Both adaptive methods provide an optimized set of apodization weights but are implemented in the time and frequency domains respectively. Their performance is evaluated with simulated synthetic aperture data obtained from Field II and is quantified by the Full-Width-Half-Maximum (FWHM), the Peak-Side-Lobe level (PSL) and the contrast level. From a point phantom, a full sequence of 128 emissions with one transducer element transmitting and all 128 elements receiving each time, provides a FWHM of 0.03 mm (0.14λ) for both implementations at a depth of 40 mm. This value is more than 20 times lower than the one achieved by conventional beamforming. The corresponding values of PSL are -58 dB and -63 dB for time and frequency domain MV beamformers, while a value no lower than -50 dB can be obtained from either Boxcar or Hanning weights. Interestingly, a single emission with central element #64 as the transmitting aperture provides results comparable to the full sequence. The values of FWHM are 0.04 mm and 0.03 mm and those of PSL are -42 dB and -46 dB for temporal and subband approaches. From a cyst phantom and for 128 emissions, the contrast level is calculated at -54 dB and -63 dB respectively at the same depth, with the initial shape of the cyst being preserved in contrast to conventional beamforming. The difference between the two adaptive beamformers is less significant in the case of a single emission, with the contrast level being estimated at -42 dB for the time domain and -43 dB for the frequency domain implementation. For the estimation of a single MV weight of a low resolution image formed by a single emission, 0.44 * 109 calculations per second are required for the temporal approach. The same numbers for the subband approach are 0.62 * 109 for the point and 1.33 * 109 for the cyst phantom. The comparison demonstrates similar resolution but slightly lower side-lobes and higher contrast for the subband approach at the expense of increased computation time.

Effects of Tribulus terrestris saponins on exercise performance in overtraining rats and the underlying mechanisms.

PubMed

Yin, Liang; Wang, Qian; Wang, Xiaohui; Song, Liang-Nian

2016-06-22

The objective of this study was to determine the effects of Tribulus terrestris L. (TT) saponins on exercise performance and the underlying mechanisms. A rat overtraining model was established and animals were treated with TT extracts (120 mg/kg body mass) 30 min before each training session. Serum levels of testosterone and corticosterone and levels of androgen receptor (AR) and insulin growth factor-1 receptor (IGF-1R) in the liver, gastrocnemius, and soleus were determined by ELISA and Western blot. Treatment of rats with TT saponins significantly improved the performance of the overtraining rats, reflected by the extension of time to exhaustion, with a concomitant increase in body mass, relative mass, and protein levels of gastrocnemius. Overtraining alone induced a significant decrease in the serum level of testosterone. In contrast, treatment with TT saponins dramatically increased the serum level of testosterone in overtraining rats to about 150% of control and 216% of overtraining groups, respectively. In addition, TT saponins resulted in a further significant increase in AR in gastrocnemius and significantly suppressed the overtraining-induced increase in IGF-1R in the liver. These results indicated that TT saponins increased performance, body mass, and gastrocnemius mass of rats undergoing overtraining, which might be attributed to the changes in androgen-AR axis and IGF-1R signaling.

Effect of descriptive information and experience on automation reliance.

PubMed

Yuviler-Gavish, Nirit; Gopher, Daniel

2011-06-01

The present research addresses the issue of reliance on decision support systems for the long-term (DSSLT), which help users develop decision-making strategies and long-term planning. It is argued that providing information about a system's future performance in an experiential manner, as compared with a descriptive manner, encourages users to increase their reliance level. Establishing appropriate reliance on DSSLT is contingent on the system developer's ability to provide users with information about the system's future performance. A sequence of three studies contrasts the effect on automation reliance of providing descriptive information versus experience for DSSLT with two different positive expected values of recommendations. Study I demonstrated that when automation reliance was determined solely on the basis of description, it was relatively low, but it increased significantly when a decision was made after experience with 50 training simulations. Participants were able to learn to increase their automation reliance levels when they encountered the same type of recommendation again. Study 2 showed that the absence of preliminary descriptive information did not affect the automation reliance levels obtained after experience. Study 3 demonstrated that participants were able to generalize their learning about increasing reliance levels to new recommendations. Using experience rather than description to give users information about future performance in DSSLT can help increase automation reliance levels. Implications for designing DSSLT and decision support systems in general are discussed.

Supplementation with Ca salts of soybean oil interacts with concentrate level in grazing dairy cows: intake, ingestive behavior, and ruminal parameters.

PubMed

Macedo, Fernanda Lopes; Batistel, Fernanda; de Souza, Jonas; Chagas, Lucas Jado; Santos, Flávio Augusto Portela

2016-12-01

In this study, we investigated the associative effects of concentrate levels and Ca salts of soybean oil (CSSO) supplementation on performance and ruminal parameters of mid-lactation dairy cows grazing on tropical pasture. Twenty-four Jersey × Holstein cows were used in a randomized block design and assigned to four treatments arranged in a 2 × 2 factorial design. Factors evaluated were concentrate levels (low, 3 kg/day vs. high, 7 kg/day of concentrate) and CSSO supplementation (without CSSO vs. with 250 g CSSO cow/day). All cows grazed on elephant grass (Pennisetum purpureum cv. Cameroon) and received the supplemental treatments for a 90-day period. The high concentrate level decreased forage intake and grazing time. In addition, the high concentrate level increased rumen propionate concentration and microbial synthesis and tended to decrease ammonia-N compared with low concentrate level. The addition of CSSO tended to decrease valerate, isobutyrate, isovalerate, and microbial synthesis. In conclusion, feeding CSSO for mid lactating cows grazing on tropical pasture had negative effects on rumen function. In contrast, CSSO supplementation tended to interact with concentrate level and increased energy intake when fed at low concentrate level. Feeding the high level of concentrate was an effective strategy to increase energy intake and microbial synthesis and improve N utilization.

[Static and dynamic contrast sensitivity of myopic eyes before and after laser in situ keratomileusis].

PubMed

Liu, Xiao-wei; Pang, Guo-xiang; Liu, Xi-pu; Jiang, Ru-xin; Jin, Yu-mei; Sun, Yu-min; Wang, Zhong-hai

2003-10-01

To evaluate the static and dynamic contrast sensitivity changes in myopic patients before and after laser in situ keratomileusis (LASIK). Seventy-three eyes in 37 patients with myopia (with or without astigmatism) who received LASIK were tested for static and dynamic contrast sensitivities using the METRO VISION MON ELEC I system at 0.7, 1.4, 2.7, 5.5, 11, and 22 cpd and cps prior to LASIK, and at one-, three-, and six-month intervals after LASIK. All eyes gained naked visual acuity of more than 0.5 after LASIK. The contrast sensitivity was depressed at all frequencies 1 month after LASIK, as compared to one week prior to LASIK. The depression at 2.7, 5.5, 11 (P < 0.01) and 22 cpd (P < 0.05) was statistically significant for static contrast sensitivity, and also at 5.5 (P < 0.01) and 11 cps (P < 0.05) for dynamic contrast sensitivity. Myopic eyes between 6.25 D and 14.0 D, and astigmatic eyes 2 DC and more, suffered more static and dynamic contrast sensitivity depression than the myopic eyes between 1.25 D and 6.00 D and astigmatic eyes less than 2 DC. Contrast sensitivities were improved and exceeded preoperative levels 3 months after LASIK, and improved even more 6 months after LASIK. All sequences were statistically significant for static contrast sensitivity (P < 0.01), while only 2.7, 5.5, and 11 cps were statistically significant for dynamic contrast sensitivity (P < 0.01). The astigmatic eyes 2 DC and more showed less improvement, even below the preoperative level at 1.4 cps of dynamic contrast sensitivity. While temporary depression of contrast sensitivity for myopic eyes after LASIK was seen, contrast sensitivity soon returned to exceed preoperative levels at 3 months after LASIK, while improving even more 6 months after LASIK.

Different Signal Enhancement Pathways of Attention and Consciousness Underlie Perception in Humans.

PubMed

van Boxtel, Jeroen J A

2017-06-14

It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms. SIGNIFICANCE STATEMENT The relationship between attention and consciousness is still debated. Mapping contrast response functions (CRFs) has allowed (neuro)scientists to gain important insights into the mechanistic underpinnings of visual processing. Here, the influence of both attention and consciousness on these functions were measured and they displayed a strong dissociation. First, attention lowered CRFs, whereas consciousness raised them. Second, attention manifests itself as a response-gain function, whereas consciousness manifests itself as a contrast-gain function. Extensive model comparisons show that these results are best explained in a two-level normalization model in which consciousness affects only the first level, whereas attention affects only the second level. These findings show dissociations between both the computational mechanisms behind attention and consciousness and the perceptual consequences that they induce. Copyright © 2017 the authors 0270-6474/17/375912-11$15.00/0.

A comparison of three methods to estimate evapotranspiration in two contrasting loblolly pine plantations: age-related changes in water use and drought sensitivity of evapotranspiration components

Treesearch

Jean-Christophe Domec; Ge Sun; Asko Noormets; Michael J. Gavazzi; Emrys A. Treasure; Erika Cohen; Jennifer J. Swenson; Steve G. McNulty; John S. King

2012-01-01

Increasing variability of rainfall patterns requires detailed understanding of the pathways of water loss from ecosystems to optimize carbon uptake and management choices. In the current study we characterized the usability of three alternative methods of different rigor for quantifying stand-level evapotranspiration (ET), partitioned ET into tree transpiration (T),...

Oral immunization of rainbow trout (Salmo gairdneri) against an etiologic agent of "redmouth disease"

USGS Publications Warehouse

1965-01-01

Rainbow trout were fed a pelleted diet containing killed cells of the etiologic agent of a bacterial disease, redmouth. These fish in addition to appropriate controls were subsequently challenged with virulent homologous organisms. Ninety per cent of the redmouth immunized fish survived the basic challenge using virulent organisms in contrast to 20% survival for the controls. Multiple challenge doses at increased levels also are discussed.

Contrasting apoptotic responses of conjugated linoleic acid in the liver of obese Zucker rats fed palm oil or ovine fat.

PubMed

Lopes, Paula A; Martins, Susana V; Viana, Ricardo S J; Ramalho, Rita M; Alfaia, Cristina M; Pinho, Mário S; Jerónimo, Eliana; Bessa, Rui J B; Castro, Matilde F; Rodrigues, Cecília M P; Prates, José A M

2011-08-01

We hypothesized that reducing weight properties of conjugated linoleic acid (CLA) are due to adipocyte apoptosis and that CLA differentially modulates the apoptotic responses in hepatic lipotoxicity from rats fed saturated fat diets. Obese Zucker rats were fed atherogenic diets (2%w/w of cholesterol) formulated with high (15%w/w) saturated fat, from vegetable or animal origin, supplemented or not with 1% of a mixture (1:1) of cis-9, trans-11 and trans-10, cis-12 CLA isomers for 14 weeks. CLA induced no changes on retroperitoneal fat depot weight, which was in line with similar levels of apoptosis. Interestingly, CLA had a contrasting effect on cell death in the liver according to the dietary fat. CLA increased hepatocyte apoptosis, associated with upregulation of Fas protein in rats fed palm oil, compared to rats receiving palm oil alone. However, rats fed ovine fat alone displayed the highest levels of hepatic cell death, which were decreased in rats fed ovine fat plus CLA. This reducing effect of CLA was related to positively restoring endoplasmic reticulum (ER) ATF-6α, BiP and CHOP protein levels and increasing phosphorylated c-Jun NH(2)-terminal kinase (JNK) and c-Jun, thus suggesting an adaptive response of cell survival. These findings reinforce the role of CLA as regulator of apoptosis in the liver. Moreover, the dietary fat composition is a key factor in activation of apoptosis. Copyright © 2011 Elsevier Ltd. All rights reserved.

New technologies lead to a new frontier: cognitive multiple data representation

NASA Astrophysics Data System (ADS)

Buffat, S.; Liege, F.; Plantier, J.; Roumes, C.

2005-05-01

The increasing number and complexity of operational sensors (radar, infrared, hyperspectral...) and availability of huge amount of data, lead to more and more sophisticated information presentations. But one key element of the IMINT line cannot be improved beyond initial system specification: the operator.... In order to overcome this issue, we have to better understand human visual object representation. Object recognition theories in human vision balance between matching 2D templates representation with viewpoint-dependant information, and a viewpoint-invariant system based on structural description. Spatial frequency content is relevant due to early vision filtering. Orientation in depth is an important variable to challenge object constancy. Three objects, seen from three different points of view in a natural environment made the original images in this study. Test images were a combination of spatial frequency filtered original images and an additive contrast level of white noise. In the first experiment, the observer's task was a same versus different forced choice with spatial alternative. Test images had the same noise level in a presentation row. Discrimination threshold was determined by modifying the white noise contrast level by means of an adaptative method. In the second experiment, a repetition blindness paradigm was used to further investigate the viewpoint effect on object recognition. The results shed some light on the human visual system processing of objects displayed under different physical descriptions. This is an important achievement because targets which not always match physical properties of usual visual stimuli can increase operational workload.

BOLD magnetic resonance imaging in nephrology

PubMed Central

Hall, Michael E; Jordan, Jennifer H; Juncos, Luis A; Hundley, W Gregory; Hall, John E

2018-01-01

Magnetic resonance (MR) imaging, a non-invasive modality that provides anatomic and physiologic information, is increasingly used for diagnosis of pathophysiologic conditions and for understanding renal physiology in humans. Although functional MR imaging methods were pioneered to investigate the brain, they also offer powerful techniques for investigation of other organ systems such as the kidneys. However, imaging the kidneys provides unique challenges due to potential complications from contrast agents. Therefore, development of non-contrast techniques to study kidney anatomy and physiology is important. Blood oxygen level-dependent (BOLD) MR is a non-contrast imaging technique that provides functional information related to renal tissue oxygenation in various pathophysiologic conditions. Here we discuss technical considerations, clinical uses and future directions for use of BOLD MR as well as complementary MR techniques to better understand renal pathophysiology. Our intent is to summarize kidney BOLD MR applications for the clinician rather than focusing on the complex physical challenges that functional MR imaging encompasses; however, we briefly discuss some of those issues. PMID:29559807

The influence of ambient light on the driver

NASA Astrophysics Data System (ADS)

Klinger, Karsten D.; Lemmer, Uli

2008-04-01

Increasingly, cars are fitted with interior ambient lighting which is switched on while driving. This special kind of interior light emphasizes the interior design of the car, it makes a car look special and gives the buyers a new option to personalize their automobiles. But how does ambient interior light influence the driver? We conducted a series of over 50 tests to study the influence of interior ambient light on contrast perception under different illumination levels, colors and positions of the illuminated areas. Our tests show that in many cases the ambient lighting can improve the visual contrast for seeing objects in the headlamp beam. But the test persons mentioned that the tested brightness looked too bright and that they felt glared. The measured values instead proved that no disability glare exists. Therefore, provided that the drivers can adjust the intensity of the ambient light to avoid glare, the ambient light has no negative effect on the drivers' contrast perception.

Effects of Transportation on Antioxidant Status in Cynomolgus Macaques (Macaca fascicularis).

PubMed

Pan, Xueying; Lu, Liang; Zeng, Xiancheng; Chang, Yan; Hua, Xiuguo

2016-01-01

To evaluate the effects of transportation on oxidative stress in cynomolgus monkeys, we measured serum levels of reduced glutathione (GSH), malondialdehyde, and protein carbonyl (PC) and the activities of total antioxidant capacity (TAOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase in cynomolgus macaques before transportation (day 0), on the day of arrival (day 1), and on days 7, 14, and 21 after transportation. Compared with that on day 0, TAOC and catalase activities on days 1, 7, and 14 after transportation were significantly decreased, reached their nadirs on day 7, and increased thereafter to reach their pretransportation levels by day 21 after transportation. Compared with day 0 levels, mean SOD activity and GSH concentration were decreased significantly on day 1; they thereafter increased to reach their pretransportation measures by day 7 after transportation. In contrast, PC and malondialdehyde concentrations in serum and the activity of GSH-Px were increased on day 1 compared with day 0 and thereafter decreased to reach their pretransportation levels by day 14 after transportation. In summary, GSH, TAOC, catalase, and SOD levels decreased and malondialdehyde, PC, and GSH-Px concentrations increased in cynomolgus macaques after transportation. These results suggest that transportation might imbalance oxidant and antioxidant levels to create excess oxidative stress in cynomolgus macaques. Therefore, cynomolgus macaques should have at least 21 d to recover after transportation and regain their healthy status.

Effects of Transportation on Antioxidant Status in Cynomolgus Macaques (Macaca fascicularis)

PubMed Central

Pan, Xueying; Lu, Liang; Zeng, Xiancheng; Chang, Yan; Hua, Xiuguo

2016-01-01

To evaluate the effects of transportation on oxidative stress in cynomolgus monkeys, we measured serum levels of reduced glutathione (GSH), malondialdehyde, and protein carbonyl (PC) and the activities of total antioxidant capacity (TAOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase in cynomolgus macaques before transportation (day 0), on the day of arrival (day 1), and on days 7, 14, and 21 after transportation. Compared with that on day 0, TAOC and catalase activities on days 1, 7, and 14 after transportation were significantly decreased, reached their nadirs on day 7, and increased thereafter to reach their pretransportation levels by day 21 after transportation. Compared with day 0 levels, mean SOD activity and GSH concentration were decreased significantly on day 1; they thereafter increased to reach their pretransportation measures by day 7 after transportation. In contrast, PC and malondialdehyde concentrations in serum and the activity of GSH-Px were increased on day 1 compared with day 0 and thereafter decreased to reach their pretransportation levels by day 14 after transportation. In summary, GSH, TAOC, catalase, and SOD levels decreased and malondialdehyde, PC, and GSH-Px concentrations increased in cynomolgus macaques after transportation. These results suggest that transportation might imbalance oxidant and antioxidant levels to create excess oxidative stress in cynomolgus macaques. Therefore, cynomolgus macaques should have at least 21 d to recover after transportation and regain their healthy status. PMID:27657707

Dopamine induces soluble α-synuclein oligomers and nigrostriatal degeneration.

PubMed

Mor, Danielle E; Tsika, Elpida; Mazzulli, Joseph R; Gould, Neal S; Kim, Hanna; Daniels, Malcolm J; Doshi, Shachee; Gupta, Preetika; Grossman, Jennifer L; Tan, Victor X; Kalb, Robert G; Caldwell, Kim A; Caldwell, Guy A; Wolfe, John H; Ischiropoulos, Harry

2017-11-01

Parkinson's disease (PD) is defined by the loss of dopaminergic neurons in the substantia nigra and the formation of Lewy body inclusions containing aggregated α-synuclein. Efforts to explain dopamine neuron vulnerability are hindered by the lack of dopaminergic cell death in α-synuclein transgenic mice. To address this, we manipulated both dopamine levels and α-synuclein expression. Nigrally targeted expression of mutant tyrosine hydroxylase with enhanced catalytic activity increased dopamine levels without damaging neurons in non-transgenic mice. In contrast, raising dopamine levels in mice expressing human A53T mutant α-synuclein induced progressive nigrostriatal degeneration and reduced locomotion. Dopamine elevation in A53T mice increased levels of potentially toxic α-synuclein oligomers, resulting in conformationally and functionally modified species. Moreover, in genetically tractable Caenorhabditis elegans models, expression of α-synuclein mutated at the site of interaction with dopamine prevented dopamine-induced toxicity. These data suggest that a unique mechanism links two cardinal features of PD: dopaminergic cell death and α-synuclein aggregation.

TH-AB-207A-01: Contrast-Enhanced CT: Correlation of Radiation Dose and Biological Effect

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

Abadi, E; Sanders, J; Agasthya, G

2016-06-15

Purpose: The potential risk from CT is generally characterized in terms of radiation dose. The presence of iodinated-contrast medium increases radiation dose. However, it is unclear how much of this increase is biologically relevant. The purpose of this study was to establish the contribution of dose increase from iodine to biological effect. Methods: Radiation organ dose was estimated in 58 human (XCAT) phantoms “undergoing” chest CT examination (120 kVp, 9 mGy CTDI) on a simulated CT system (Definition Flash, Siemens) with and without iodinated-contrast agent (62.5 mL of iodine per subject). The dose without and with the presence of iodinemore » was compared to the increase in foci per cell (a surrogate of DNA damage) measured before and after similar CT exams without and with contrast agent (Piechowiak et al. 2015). The data were analyzed to ascertain how the enhancement in biological effect in contrast-enhanced CTs correlated with the increase in dose due to the presence of iodine. Results: The presence of iodinated-contrast in CT increased the organ doses by 2% to 50% on average. Typical values were heart (50%±7%), kidney (19%±7%), and liver (2%±3%). The corresponding increase in the average foci per cell was 107%±19%, indicating biological effect of iodine was greater than what would be anticipated from the iodine-initiated increase in radiation dose alone. Conclusion: Mean foci per cell and organ dose both increase in the presence of contrast agent. The former, however, is at least twice as large as the latter, indicating that iodine contributes to an increase in the probability of DNA damage not only as a consequence of increased x-ray energy deposition but also from other mechanisms. Hence iodine radiation dose, while relevant to be included in estimating the risk associated with contrast-enhanced CT, still can underestimate the biological effects.« less

Space Station Freedom resource allocation accommodation of technology payload requirements

NASA Technical Reports Server (NTRS)

Avery, Don E.; Collier, Lisa D.; Gartrell, Charles F.

1990-01-01

An overview of the Office of Aeronautics, Exploration, and Technology (OAET) Space Station Freedom Technology Payload Development Program is provided, and the OAET Station resource requirements are reviewed. The requirements are contrasted with current proposed resource allocations. A discussion of the issues and conclusions are provided. It is concluded that an overall 20 percent resource allocation is appropriate to support OAET's technology development program, that some resources are inadequate even at the 20 percent level, and that bartering resources among U.S. users and international partners and increasing the level of automation may be viable solutions to the resource constraint problem.

Maternal dietary intake of polyunsaturated fatty acids modifies association between prenatal DDT exposure and child neurodevelopment: A cohort study.

PubMed

Ogaz-González, Rafael; Mérida-Ortega, Ángel; Torres-Sánchez, Luisa; Schnaas, Lourdes; Hernández-Alcaraz, César; Cebrián, Mariano E; Rothenberg, Stephen J; García-Hernández, Rosa María; López-Carrillo, Lizbeth

2018-07-01

Maternal 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) serum levels during pregnancy have been negatively linked to child neurodevelopment in contrast to intake of omega-3 and -6 (ω-3 and ω-6) fatty acids. To assess whether maternal dietary intake of ω-3 and ω-6 during pregnancy modifies the association between exposure to DDE and child neurodevelopment from age 42-60 months. Prospective cohort study with 142 mother-child pairs performed in Mexico. DDE serum levels were determined by electron capture gas chromatography. Dietary ω-3 and ω-6 intake was estimated by questionnaire. Child neurodevelopment was assessed by McCarthy Scales. Docosahexaenoic (DHA) fatty acid intake significantly modified the association between DDE and motor component: increased maternal DDE was associated with lower motor development in children whose mothers had lower DHA intake (β log2DDE  = -1.25; 95% CI: -2.62, 0.12), in contrast to the non-significant increase among children whose mothers had higher DHA intake (β log2DDE-motor  = 0.50; 95% CI: 0.55, 1.56). Likewise, arachidonic fatty acid (ARA) intake modified the association between DDE and memory component: increased maternal DDE was associated with a significantly larger reduction in the memory component in children whose mothers had lower ARA intake (β log2DDE  = -1.31; 95% CI: -2.29, -0.32) than children whose mothers had higher ARA intake (β log2DDE-memory  = 0.17; 95% CI: -0.78, 1.11). Dietary intake of DHA and ARA during pregnancy may protect against child neurodevelopment damage associated with prenatal maternal DDE levels. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fluctuations in nucleus accumbens extracellular glutamate and glucose during motivated glucose-drinking behavior: dissecting the neurochemistry of reward.

PubMed

Wakabayashi, Ken T; Myal, Stephanie E; Kiyatkin, Eugene A

2015-02-01

While motivated behavior involves multiple neurochemical systems, few studies have focused on the role of glutamate, the brain's excitatory neurotransmitter, and glucose, the energetic substrate of neural activity in reward-related neural processes. Here, we used high-speed amperometry with enzyme-based substrate-sensitive and control, enzyme-free biosensors to examine second-scale fluctuations in the extracellular levels of these substances in the nucleus accumbens shell during glucose-drinking behavior in trained rats. Glutamate rose rapidly after the presentation of a glucose-containing cup and before the initiation of drinking (reward seeking), decreased more slowly to levels below baseline during consumption (sensory reward), and returned to baseline when the ingested glucose reached the brain (metabolic reward). When water was substituted for glucose, glutamate rapidly increased with cup presentation and in contrast to glucose drinking, increased above baseline after rats tasted the water and refused to drink further. Therefore, extracellular glutamate show distinct changes associated with key events of motivated drinking behavior and opposite dynamics during sensory and metabolic components of reward. In contrast to glutamate, glucose increased at each stimulus and behavioral event, showing a sustained elevation during the entire behavior and a robust post-ingestion rise that correlated with the gradual return of glutamate levels to their baseline. By comparing active drinking with passive intra-gastric glucose delivery, we revealed that fluctuations in extracellular glucose are highly dynamic, reflecting a balance between rapid delivery because of neural activity, intense metabolism, and the influence of ingested glucose reaching the brain. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Proteomic profiling of the antifungal drug response of Aspergillus fumigatus to voriconazole.

PubMed

Amarsaikhan, Nansalmaa; Albrecht-Eckardt, Daniela; Sasse, Christoph; Braus, Gerhard H; Ogel, Zumrut B; Kniemeyer, Olaf

2017-10-01

Antifungal resistance is an emerging problem and one of the reasons for treatment failure of invasive aspergillosis (IA). Voriconazole has become a standard therapeutic for the treatment of this often fatal infection. We studied the differentially expressed proteins as a response of Aspergillus fumigatus to voriconazole by employing the two-dimensional difference gel electrophoresis (DIGE) technique. Due to addition of drug, a total of 135 differentially synthesized proteins were identified by MALDI-TOF/TOF-mass spectrometry. In particular, the level of proteins involved in the general stress response and cell detoxification increased prominently. In contrast, cell metabolism and energy proteins were down-regulated, which suggests the cellular effort to maintain balance in energy utilization while trying to combat the cellular stress exerted by the drug. We detected several so-far uncharacterized proteins which may play a role in stress response and drug metabolism and which could be future targets for antifungal treatment. A mutant strain, which is deleted in the cross-pathway control gene cpcA, was treated with voriconazole to investigate the contribution of the general control of amino acid biosynthesis to drug resistance. We compared the mutant strain's protein expression profile with the wild-type strain. The absence of CpcA led to an increased resistance to voriconazole and a reduced activation of some general stress response proteins, while the transcript level of the triazole target gene erg11A (cyp51A) remained unchanged. In contrast, the sensitivity of strain ΔcpcA to terbinafine and amphotericin B was slightly increased. These findings imply a role of CpcA in the cellular stress response to azole drugs at the post transcriptional level. Copyright © 2017 Elsevier GmbH. All rights reserved.

Proximate composition and lipid stability of dourado (Salminus brasilensis, Cuvier, 1817) fillets exposed to different levels of ammonia and oxygen in vivo.

PubMed

Veeck, Ana Paula L; Garcia, Luciano O; Baldisserotto, Bernardo; Zaniboni Filho, Evoy; Emanuelli, Tatiana

2013-08-15

The ammonia and oxygen levels of water are physicochemical parameters that affect fish physiology. Thus, we hypothesized that in vivo exposure to stressful ammonia and oxygen levels will affect the post-mortem quality of the fish. Therefore, in this study, the effects of in vivo exposure to stressful ammonia and oxygen levels on the composition and content of thiobarbituric acid reactive substances in fillets from dourado (Salminus brasiliensis) and on the lipid oxidation of these fillets during frozen storage were evaluated. Short-term exposure (12 h) to stressful environmental conditions (low oxygen and high ammonia levels) did not change the composition of the flesh. However, longer exposure (15 days) to these stressful conditions caused significant changes in the composition of the flesh. Exposure to a stressful ammonia level before slaughtering increased the susceptibility of the fish fillets to lipid oxidation during frozen storage. In contrast, exposure to low oxygen levels did not increase the lipid oxidation rate of the fillets. These results indicate that the in vivo exposure to high ammonia levels may reduce the quality and stability of dourado fillets. © 2013 Society of Chemical Industry.

Spectral variability of photospheric radiation due to faculae. I. The Sun and Sun-like stars

NASA Astrophysics Data System (ADS)

Norris, Charlotte M.; Beeck, Benjamin; Unruh, Yvonne C.; Solanki, Sami K.; Krivova, Natalie A.; Yeo, Kok Leng

2017-09-01

Context. Stellar spectral variability on timescales of a day and longer, arising from magnetic surface features such as dark spots and bright faculae, is an important noise source when characterising extra-solar planets. Current 1D models of faculae do not capture the geometric properties and fail to reproduce observed solar facular contrasts. Magnetoconvection simulations provide facular contrasts accounting for geometry. Aims: We calculate facular contrast spectra from magnetoconvection models of the solar photosphere with a view to improve (a) future parameter determinations for planets with early G type host stars and (b) reconstructions of solar spectral variability. Methods: Regions of a solar twin (G2, log g = 4.44) atmosphere with a range of initial average vertical magnetic fields (100 to 500 G) were simulated using a 3D radiation-magnetohydrodynamics code, MURaM, and synthetic intensity spectra were calculated from the ultraviolet (149.5 nm) to the far infrared (160 000 nm) with the ATLAS9 radiative transfer code. Nine viewing angles were investigated to account for facular positions across most of the stellar disc. Results: Contrasts of the radiation from simulation boxes with different levels of magnetic flux relative to an atmosphere with no magnetic field are a complicated function of position, wavelength and magnetic field strength that is not reproduced by 1D facular models. Generally, contrasts increase towards the limb, but at UV wavelengths a saturation and decrease are observed close to the limb. Contrasts also increase strongly from the visible to the UV; there is a rich spectral dependence, with marked peaks in molecular bands and strong spectral lines. At disc centre, a complex relationship with magnetic field was found and areas of strong magnetic field can appear either dark or bright, depending on wavelength. Spectra calculated for a wide variety of magnetic fluxes will also serve to improve total and spectral solar irradiance reconstructions.

Assessing the effect of football play on knee articular cartilage using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

PubMed

Wei, Wenbo; Lambach, Becky; Jia, Guang; Flanigan, David; Chaudhari, Ajit M W; Wei, Lai; Rogers, Alan; Payne, Jason; Siston, Robert A; Knopp, Michael V

2017-06-01

The prevalence of cartilage lesions is much higher in football athletes than in the general population. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been shown to quantify regional variations of glycosaminoglycan (GAG) concentrations which is an indicator of early cartilage degeneration. The goal of this study is to determine whether dGEMRIC can be used to assess the influence in cartilage GAG concentration due to college level football play. Thirteen collegiate football players with one to four years of collegiate football play experience were recruited and both knee joints were scanned using a dedicated 8-channel phased array knee coil on a 3T MRI system. The contrast concentrations within cartilage were calculated based on the T 1 values from dGEMRIC scans. No substantial differences were found in the contrast concentrations between the pre- and post-season across all the cartilage compartments. One year collegiate football players presented an average contrast concentration at the pre-season of 0.116±0.011mM and post-season of 0.116±0.011mM. In players with multiple years of football play, contrast uptake was elevated to 0.141±0.012mM at the pre-season and 0.139±0.012mM at the post-season. The pre-season 0.023±0.016mM and post-season 0.025±0.016mM increase in contrast concentration within the group with multiple years of experience presented with a >20% increase in contrast uptake. This may indicate the gradual, cumulative damage of football play to the articular cartilage over years, even though the effect may not be noticeable after a season of play. Playing collegiate football for a longer period of time may lead to cartilage microstructural alterations, which may be linked to early knee cartilage degeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Gadolinium-Based Contrast Agents for MR Cancer Imaging

PubMed Central

Zhou, Zhuxian; Lu, Zheng-Rong

2013-01-01

Magnetic resonance imaging (MRI) is a clinical imaging modality effective for anatomical and functional imaging of diseased soft tissues, including solid tumors. MRI contrast agents have been routinely used for detecting tumor at an early stage. Gadolinium based contrast agents are the most commonly used contrast agents in clinical MRI. There have been significant efforts to design and develop novel Gd(III) contrast agents with high relaxivity, low toxicity and specific tumor binding. The relaxivity of the Gd(III) contrast agents can be increased by proper chemical modification. The toxicity of Gd(III) contrast agents can be reduced by increasing the agents’ thermodynamic and kinetic stability, as well as optimizing their pharmacokinetic properties. The increasing knowledge in the field of cancer genomics and biology provides an opportunity for designing tumor-specific contrast agents. Various new Gd(III) chelates have been designed and evaluated in animal models for more effective cancer MRI. This review outlines the design and development, physicochemical properties, and in vivo properties of several classes of Gd(III)-based MR contrast agents for tumor imaging. PMID:23047730

Neonatal Overnutrition Increases Testicular Size and Expression of Luteinizing Hormone β-Subunit in Peripubertal Male Rats

PubMed Central

Argente-Arizón, Pilar; Castro-González, David; Díaz, Francisca; Fernández-Gómez, María J.; Sánchez-Garrido, Miguel A.; Tena-Sempere, Manuel; Argente, Jesús; Chowen, Julie A.

2018-01-01

Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition) or 12 pups (controls) per dam. Leptin was administered sc (3 µg/g body weight) at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH) beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but with no change in testosterone levels. In conclusion, the advancement in pubertal onset in males with neonatal overnutrition does not appear to be related to overt modifications in the central response to exogenous leptin during the peripubertal period. PMID:29706935

Neonatal Overnutrition Increases Testicular Size and Expression of Luteinizing Hormone β-Subunit in Peripubertal Male Rats.

PubMed

Argente-Arizón, Pilar; Castro-González, David; Díaz, Francisca; Fernández-Gómez, María J; Sánchez-Garrido, Miguel A; Tena-Sempere, Manuel; Argente, Jesús; Chowen, Julie A

2018-01-01

Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition) or 12 pups (controls) per dam. Leptin was administered sc (3 µg/g body weight) at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH) beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but with no change in testosterone levels. In conclusion, the advancement in pubertal onset in males with neonatal overnutrition does not appear to be related to overt modifications in the central response to exogenous leptin during the peripubertal period.

Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings.

PubMed

Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

2017-01-01

Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H 2 O 2 ) under chilling stress conditions using tomato seedlings [( Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 24 h), the application of spermidine (Spd) and spermine (Spm) elevated NO and H 2 O 2 levels, enhanced nitrite reductase (NR), nitric oxide synthase (NOS)-like, and polyamine oxidase activities, and upregulated LeNR relative expression, but did not influence LeNOS1 expression. In contrast, putrescine (Put) treatment had no obvious impact. During the recovery period (25/15°C, 10 h), the above-mentioned parameters induced by the application of PAs were restored to their control levels. Seedlings pretreated with sodium nitroprusside (SNP, an NO donor) showed elevated Put and Spd levels throughout the treatment period, consistent with increased expression in leaves of genes encoding arginine decarboxylase ( LeADC. LeADC1 ), ornithine decarboxylase ( LeODC ), and Spd synthase ( LeSPDS ) expressions in tomato leaves throughout the treatment period. Under chilling stress, the Put content increased first, followed by a rise in the Spd content. Exogenously applied SNP did not increase the expression of genes encoding S -adenosylmethionine decarboxylase ( LeSAMDC ) and Spm synthase ( LeSPMS ), consistent with the observation that Spm levels remained constant under chilling stress and during the recovery period. In contrast, exogenous Put significantly increased the ABA content and the 9- cis -epoxycarotenoid dioxygenase ( LeNCED1 ) transcript level. Treatment with ABA could alleviate the electrolyte leakage (EL) induced by D-Arg (an inhibitor of Put). Taken together, it is concluded that, under chilling stress, Spd and Spm enhanced the production of NO in tomato seedlings through an H 2 O 2 -dependent mechanism, via the NR and NOS-like pathways. ABA is involved in Put-induced tolerance to chilling stress, and NO could increase the content of Put and Spd under chilling stress.

Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings

PubMed Central

Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

2017-01-01

Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H2O2) under chilling stress conditions using tomato seedlings [(Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 24 h), the application of spermidine (Spd) and spermine (Spm) elevated NO and H2O2 levels, enhanced nitrite reductase (NR), nitric oxide synthase (NOS)-like, and polyamine oxidase activities, and upregulated LeNR relative expression, but did not influence LeNOS1 expression. In contrast, putrescine (Put) treatment had no obvious impact. During the recovery period (25/15°C, 10 h), the above-mentioned parameters induced by the application of PAs were restored to their control levels. Seedlings pretreated with sodium nitroprusside (SNP, an NO donor) showed elevated Put and Spd levels throughout the treatment period, consistent with increased expression in leaves of genes encoding arginine decarboxylase (LeADC. LeADC1), ornithine decarboxylase (LeODC), and Spd synthase (LeSPDS) expressions in tomato leaves throughout the treatment period. Under chilling stress, the Put content increased first, followed by a rise in the Spd content. Exogenously applied SNP did not increase the expression of genes encoding S-adenosylmethionine decarboxylase (LeSAMDC) and Spm synthase (LeSPMS), consistent with the observation that Spm levels remained constant under chilling stress and during the recovery period. In contrast, exogenous Put significantly increased the ABA content and the 9-cis-epoxycarotenoid dioxygenase (LeNCED1) transcript level. Treatment with ABA could alleviate the electrolyte leakage (EL) induced by D-Arg (an inhibitor of Put). Taken together, it is concluded that, under chilling stress, Spd and Spm enhanced the production of NO in tomato seedlings through an H2O2-dependent mechanism, via the NR and NOS-like pathways. ABA is involved in Put-induced tolerance to chilling stress, and NO could increase the content of Put and Spd under chilling stress. PMID:28261254

Contrast Induced by a Static Magnetic Field for Improved Detection in Nanodiamond Fluorescence Microscopy

NASA Astrophysics Data System (ADS)

Singam, Shashi K. R.; Motylewski, Jaroslaw; Monaco, Antonina; Gjorgievska, Elena; Bourgeois, Emilie; Nesládek, Milos; Giugliano, Michele; Goovaerts, Etienne

2016-12-01

Diamond nanoparticles with negatively charged nitrogen-vacancy (NV) centers are highly efficient nonblinking emitters that exhibit spin-dependent intensity. An attractive application of these emitters is background-free fluorescence microscopy exploiting the fluorescence quenching induced either by resonant microwaves (RMWs) or by an applied static magnetic field (SMF). Here, we compare RMW- and SMF-induced contrast measurements over a wide range of optical excitation rates for fluorescent nanodiamonds (FNDs) and for NV centers shallowly buried under the (100)-oriented surface of a diamond single crystal (SC). Contrast levels are found to be systematically lower in the FNDs than in the SC. At low excitation rates, the RMW contrast initially rises to a maximum (up to 7% in FNDs and 13% in the SC) but then decreases steadily at higher intensities. Conversely, the SMF contrast increases from approximately 12% at low excitation rates to high values of 20% and 38% for the FNDs and SC, respectively. These observations are well described in a rate-equations model for the charged NV defect using parameters in good agreement with the literature. The SMF approach yields higher induced contrast in image collection under commonly applied optical excitation. Unlike the RMW method, there is no thermal load exerted on the aqueous media in biological samples in the SMF approach. We demonstrate imaging by SMF-induced contrast in neuronal cultures incorporating FNDs (i) in a setup for patch-clamp experiments in parallel with differential-interference-contrast microscopy, (ii) after a commonly used staining procedure as an illustration of the high selectivity against background fluorescence, and (iii) in a confocal fluorescence microscope in combination with bright-field microscopy.

Contrasts in Seismicity Along the 1964 Great Alaska Earthquake Rupture Zone

NASA Astrophysics Data System (ADS)

Doser, D. I.; Veilleux, A. M.; Flores, C.; Brown, W. A.

2004-12-01

We have examined seismicity occurring over 35 years prior to and following the 1964 great Alaska earthquake. These studies indicate that the regions associated with the Prince William Sound (PWS) and Kodiak asperities have behaved very different seismically over time. Prior to 1964, the PWS region experienced an increase in crustal seismicity, especially in the region located down-dip of maximum slip in 1964. Since 1964 this same region has been aseismic at the M> 3 level. PWS intraslab seismicity has remained relatively constant, although down-dip migration of M > 4.5 events was observed following the 1964 mainshock. Low-level seismicity has occurred at the northeastern end of the Kodiak asperity throughout the past 70 years, but much of the central Kodiak asperity has been aseismic at the M > 5 level. In contrast, the southwestern edge of the Kodiak asperity has been associated with moderate to large (Mw 5.5 to 7) crustal, interplate, and intraslab events throughout the past 70 years. These changes in seismic behavior along the 1964 rupture zone are consistent with GPS/geodesy estimates of seismic coupling across the interface and with known changes in plate geometry.

BRD4 inhibitor IBET upregulates p27kip/cip protein stability in neuroendocrine tumor cells.

PubMed

Wang, Lei; Matkar, Smita; Xie, Gengchen; An, Chiying; He, Xin; Kong, Xiangchen; Liu, Xiuheng; Hua, Xianxin

2017-04-03

The prevalence of neuroendocrine tumors (NETs) has recently been increasing. Although various drugs such as Octreotide and its analogs show certain efficacy, NETs in many patients progress and metastasize. It is desirable to develop new interventions to improve the therapy. Here we show that human neuroendocrine tumor BON cells are resistant to several drugs commonly used for NET therapy, including Octreotide that activates somatostatin receptor-induced anti-proliferation, and Capecitabine and Temozolimide that damage DNA. In contrast, an inhibitor (IBET) to an epigenetic regulator, Brd4 that binds acetylated histones and upregulates transcription of multiple genes including protooncogene c-Myc, potently inhibited the NET cells. We found that IBET increased the protein levels of cyclin-dependent kinase (CDK) inhibitor p27 kip/cip (or p27), but not its mRNA levels. Moreover, the p27 induction at protein level by IBET was at least partly through increasing the protein stability of p27. The increased protein stability of p27 likely resulted from IBET-mediated suppression of Skp2, an E3 ligase that can mediate p27 degradation by increasing its ubiquitinylation. These findings unravel a new mechanism whereby the IBET-induced repression of proliferation of neuroendocrine cells.

Increased Circulating FGF23 Does Not Lead to Cardiac Hypertrophy in the Male Hyp Mouse Model of XLH.

PubMed

Liu, Eva S; Thoonen, Robrecht; Petit, Elizabeth; Yu, Binglan; Buys, Emmanuel S; Scherrer-Crosbie, Marielle; Demay, Marie B

2018-05-01

Serum levels of fibroblast growth factor 23 (FGF23) markedly increase with renal impairment, with FGF23 levels correlating with the presence of left ventricular hypertrophy (LVH) and mortality in patients with chronic kidney disease (CKD). FGF23 activates calcineurin/nuclear factor of activated T cell (NFAT) signaling and induces hypertrophy in murine cardiomyocytes. X-linked hypophosphatemia (XLH) is characterized by high circulating levels of FGF23 but, in contrast to CKD, is associated with hypophosphatemia. The cardiac effects of high circulating levels of FGF23 in XLH are not well defined. Thus, studies were undertaken to define the cardiac phenotype in the mouse model of XLH (Hyp mice). Echocardiographic and histological analyses demonstrated that Hyp left ventricles (LVs) are smaller than those of wild-type mice. Messenger RNA expression of cardiac hypertrophy markers was not altered in the LV or right ventricle of Hyp mice. However, the Hyp LVs had increased expression of the NFAT target genes NFATc1 and RCAN1. To determine whether phosphate alone can induce markers of hypertrophy, differentiated C2C12 myocytes were treated with phosphate. Phosphate treatment increased expression of cardiac hypertrophy markers, supporting a primary role for phosphate in inducing LVH. Although previous studies showed that increased circulating FGF23 and phosphate levels are associated with LVH, our results demonstrated that in XLH, high circulating levels of FGF23 in the setting of hypophosphatemia do not induce cardiac hypertrophy.

Accounting for correlation in network meta-analysis with multi-arm trials.

PubMed

Franchini, A J; Dias, S; Ades, A E; Jansen, J P; Welton, N J

2012-06-01

Multi-arm trials (trials with more than two arms) are particularly valuable forms of evidence for network meta-analysis (NMA). Trial results are available either as arm-level summaries, where effect measures are reported for each arm, or as contrast-level summaries, where the differences in effect between arms compare with the control arm chosen for the trial. We show that likelihood-based inference in both contrast-level and arm-level formats is identical if there are only two-arm trials, but that if there are multi-arm trials, results from the contrast-level format will be incorrect unless correlations are accounted for in the likelihood. We review Bayesian and frequentist software for NMA with multi-arm trials that can account for this correlation and give an illustrative example of the difference in estimates that can be introduced if the correlations are not incorporated. We discuss methods of imputing correlations when they cannot be derived from the reported results and urge trialists to report the standard error for the control arm even if only contrast-level summaries are reported. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.

Landscape-level controls on dissolved carbon flux from diverse catchments of the circumboreal

USGS Publications Warehouse

Tank, Suzanne; Frey, Karen E.; Striegl, Robert G.; Raymond, Peter A.; Holmes, R. Max; McClelland, James W.; Peterson, Bruce J.

2012-01-01

While much of the dissolved organic carbon (DOC) within rivers is destined for mineralization to CO2, a substantial fraction of riverine bicarbonate (HCO3-) flux represents a CO2 sink, as a result of weathering processes that sequester CO2 as HCO3-. We explored landscape-level controls on DOC and HCO3- flux in subcatchments of the boreal, with a specific focus on the effect of permafrost on riverine dissolved C flux. To do this, we undertook a multivariate analysis that partitioned the variance attributable to known, key regulators of dissolved C flux (runoff, lithology, and vegetation) prior to examining the effect of permafrost, using riverine biogeochemistry data from a suite of subcatchments drawn from the Mackenzie, Yukon, East, and West Siberian regions of the circumboreal. Across the diverse catchments that we study, controls on HCO3- flux were near-universal: runoff and an increased carbonate rock contribution to weathering (assessed as riverwater Ca:Na) increased HCO3- yields, while increasing permafrost extent was associated with decreases in HCO3-. In contrast, permafrost had contrasting and region-specific effects on DOC yield, even after the variation caused by other key drivers of its flux had been accounted for. We used ionic ratios and SO4 yields to calculate the potential range of CO2 sequestered via weathering across these boreal subcatchments, and show that decreasing permafrost extent is associated with increases in weathering-mediated CO2 fixation across broad spatial scales, an effect that could counterbalance some of the organic C mineralization that is predicted with declining permafrost.

Dynamics of lineage commitment revealed by single-cell transcriptomics of differentiating embryonic stem cells.

PubMed

Semrau, Stefan; Goldmann, Johanna E; Soumillon, Magali; Mikkelsen, Tarjei S; Jaenisch, Rudolf; van Oudenaarden, Alexander

2017-10-23

Gene expression heterogeneity in the pluripotent state of mouse embryonic stem cells (mESCs) has been increasingly well-characterized. In contrast, exit from pluripotency and lineage commitment have not been studied systematically at the single-cell level. Here we measure the gene expression dynamics of retinoic acid driven mESC differentiation from pluripotency to lineage commitment, using an unbiased single-cell transcriptomics approach. We find that the exit from pluripotency marks the start of a lineage transition as well as a transient phase of increased susceptibility to lineage specifying signals. Our study reveals several transcriptional signatures of this phase, including a sharp increase of gene expression variability and sequential expression of two classes of transcriptional regulators. In summary, we provide a comprehensive analysis of the exit from pluripotency and lineage commitment at the single cell level, a potential stepping stone to improved lineage manipulation through timing of differentiation cues.

Elevated carbon dioxide increases salicylic acid in Glycine max.

PubMed

Casteel, Clare L; Segal, Lauren M; Niziolek, Olivia K; Berenbaum, May R; DeLucia, Evan H

2012-12-01

Concentrations of carbon dioxide (CO(2)) are increasing in the atmosphere, affecting soybean (Glycine max L.) phytohormone signaling and herbivore resistance. Whether the impact of elevated CO(2) on phytohormones and induced defenses is a generalized response within this species is an open question. We examined jasmonic acid (JA) and salicylic acid (SA) under ambient and elevated CO(2) concentrations with and without Japanese beetle (Popillia japonica Newman) damage and artificial damage across six soybean cultivars (HS93-4118, Pana, IA 3010, Loda, LN97-15076, and Dwight). Elevated CO(2) reduced constitutive levels of JA and related transcripts in some but not all soybean cultivars. In contrast to the variation in JA, constitutive levels of salicylic were increased universally among soybean cultivars grown under elevated CO(2). Variation in hormonal signaling may underpin observed variation in the response of insect herbivores and pathogens to plants grown under elevated CO(2).

Pairwise comparisons of ten porcine tissues identify differential transcriptional regulation at the gene, isoform, promoter and transcription start site level

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

Farajzadeh, Leila; Hornshøj, Henrik; Momeni, Jamal

Highlights: •Transcriptome sequencing yielded 223 mill porcine RNA-seq reads, and 59,000 transcribed locations. •Establishment of unique transcription profiles for ten porcine tissues including four brain tissues. •Comparison of transcription profiles at gene, isoform, promoter and transcription start site level. •Highlights a high level of regulation of neuro-related genes at both gene, isoform, and TSS level. •Our results emphasize the pig as a valuable animal model with respect to human biological issues. -- Abstract: The transcriptome is the absolute set of transcripts in a tissue or cell at the time of sampling. In this study RNA-Seq is employed to enable themore » differential analysis of the transcriptome profile for ten porcine tissues in order to evaluate differences between the tissues at the gene and isoform expression level, together with an analysis of variation in transcription start sites, promoter usage, and splicing. Totally, 223 million RNA fragments were sequenced leading to the identification of 59,930 transcribed gene locations and 290,936 transcript variants using Cufflinks with similarity to approximately 13,899 annotated human genes. Pairwise analysis of tissues for differential expression at the gene level showed that the smallest differences were between tissues originating from the porcine brain. Interestingly, the relative level of differential expression at the isoform level did generally not vary between tissue contrasts. Furthermore, analysis of differential promoter usage between tissues, revealed a proportionally higher variation between cerebellum (CBE) versus frontal cortex and cerebellum versus hypothalamus (HYP) than in the remaining comparisons. In addition, the comparison of differential transcription start sites showed that the number of these sites is generally increased in comparisons including hypothalamus in contrast to other pairwise assessments. A comprehensive analysis of one of the tissue contrasts, i.e. cerebellum versus heart for differential variation at the gene, isoform, and transcription start site (TSS), and promoter level showed that several of the genes differed at all four levels. Interestingly, these genes were mainly annotated to the “electron transport chain” and neuronal differentiation, emphasizing that “tissue important” genes are regulated at several levels. Furthermore, our analysis shows that the “across tissue approach” has a promising potential when screening for possible explanations for variations, such as those observed at the gene expression levels.« less

Sea level and turbidity controls on mangrove soil surface elevation change

USGS Publications Warehouse

Lovelock, Catherine E.; Fernanda Adame, Maria; Bennion, Vicki; Hayes, Matthew; Reef, Ruth; Santini, Nadia; Cahoon, Donald R.

2015-01-01

Increases in sea level are a threat to seaward fringing mangrove forests if levels of inundation exceed the physiological tolerance of the trees; however, tidal wetlands can keep pace with sea level rise if soil surface elevations can increase at the same pace as sea level rise. Sediment accretion on the soil surface and belowground production of roots are proposed to increase with increasing sea level, enabling intertidal habitats to maintain their position relative to mean sea level, but there are few tests of these predictions in mangrove forests. Here we used variation in sea level and the availability of sediments caused by seasonal and inter-annual variation in the intensity of La Nina-El Nino to assess the effects of increasing sea level on surface elevation gains and contributing processes (accretion on the surface, subsidence and root growth) in mangrove forests. We found that soil surface elevation increased with mean sea level (which varied over 250 mm during the study) and with turbidity at sites where fine sediment in the water column is abundant. In contrast, where sediments were sandy, rates of surface elevation gain were high, but not significantly related to variation in turbidity, and were likely to be influenced by other factors that deliver sand to the mangrove forest. Root growth was not linked to soil surface elevation gains, although it was associated with reduced shallow subsidence, and therefore may contribute to the capacity of mangroves to keep pace with sea level rise. Our results indicate both surface (sedimentation) and subsurface (root growth) processes can influence mangrove capacity to keep pace with sea level rise within the same geographic location, and that current models of tidal marsh responses to sea level rise capture the major feature of the response of mangroves where fine, but not coarse, sediments are abundant.

Magnetomotive Molecular Nanoprobes

PubMed Central

John, Renu; Boppart, Stephen A.

2012-01-01

Tremendous developments in the field of biomedical imaging in the past two decades have resulted in the transformation of anatomical imaging to molecular-specific imaging. The main approaches towards imaging at a molecular level are the development of high resolution imaging modalities with high penetration depths and increased sensitivity, and the development of molecular probes with high specificity. The development of novel molecular contrast agents and their success in molecular optical imaging modalities have lead to the emergence of molecular optical imaging as a more versatile and capable technique for providing morphological, spatial, and functional information at the molecular level with high sensitivity and precision, compared to other imaging modalities. In this review, we discuss a new class of dynamic contrast agents called magnetomotive molecular nanoprobes for molecular-specific imaging. Magnetomotive agents are superparamagnetic nanoparticles, typically iron-oxide, that are physically displaced by the application of a small modulating external magnetic field. Dynamic phase-sensitive position measurements are performed using any high resolution imaging modality, including optical coherence tomography (OCT), ultrasonography, or magnetic resonance imaging (MRI). The dynamics of the magnetomotive agents can be used to extract the biomechanical tissue properties in which the nanoparticles are bound, and the agents can be used to deliver therapy via magnetomotive displacements to modulate or disrupt cell function, or hyperthermia to kill cells. These agents can be targeted via conjugation to antibodies, and in vivo targeted imaging has been shown in a carcinogen-induced rat mammary tumor model. The iron-oxide nanoparticles also exhibit negative T2 contrast in MRI, and modulations can produce ultrasound imaging contrast for multimodal imaging applications. PMID:21517766

Doxorubicin Delivery into Tumor Cells by Stable Cavitation without Contrast Agents.

PubMed

Chettab, Kamel; Mestas, Jean-Louis; Lafond, Maxime; Saadna, Djamel Eddine; Lafon, Cyril; Dumontet, Charles

2017-02-06

Doxorubicin, alone or in combination with other anticancer agents, is one of the most widely used chemotherapeutic agents and is administered in a wide range of cancers. However, the use of doxorubicin is limited due to its potential serious adverse reactions. Previous studies have established the ability of high intensity focused ultrasound (HIFU) in combination with various contrast agents to increase intracellular doxorubicin delivery in a targeted and noninvasive manner. In this study, we developed a new sonoporation device generating and monitoring acoustic cavitation bubbles without any addition of contrast agents. The device was used to potentiate the delivery of active doxorubicin into both adherent and suspended cell lines. Combining doxorubicin with ultrasound resulted in a significant enhancement of doxorubicin intracellular delivery and a decrease in cell viability at 48 and 72 h, in comparison to doxorubicin alone. More importantly and unlike previous investigations, our procedure does not require the addition of contrast agents to generate acoustic cavitation and to achieve high levels of doxorubicin delivery. The successful translation of this approach for an in vivo application may allow a significant reduction in the dosage and the adverse effects of doxorubicin therapy in patients.

Removal of gadolinium by peritoneal dialysis.

PubMed

Murashima, M; Drott, H R; Carlow, D; Shaw, L M; Milone, M; Bachman, M; Tsai, D E; Yang, S-L; Bloom, R D

2008-05-01

An association between gadolinium-containing contrast and the development of nephrogenic systemic fibrosis (NSF) has been increasingly recognized. For patients receiving hemodialysis (HD) who are exposed to gadolinium, the Federal Drug Administration (FDA) recommends HD to remove this contrast agent in order to minimize the risk of NSF. This study examines if gadolinium can be removed by frequent exchanges by peritoneal dialysis (PD). Following administration of 0.1 mmol/kg of gadodiamide to a patient with end-stage renal disease, the serum clearance of this contrast agent by automated PD was examined. 10 and 15 exchanges of PD using an automated cycler were respectively performed during the first and second 24-hour periods after gadolinium exposure. Serum gadolinium levels were measured 1 hour after the gadolinium administration, then at 24 and 48 hours after PD was initiated. 90% of the gadolinium was removed from the circulation in 2 days with a regimen of 10-15 exchanges per day of PD. For patients on chronic maintenance PD who receive gadolinium, our case suggests that a temporary intensive automated PD regimen, aimed at maximizing clearance of this contrast agent immediately after exposure, could be an effective alternative when institution of HD is problematic.

Effects of Lactobacillus rhamnosus GG on the maturation and differentiation of dendritic cells in rotavirus-infected mice.

PubMed

Jiang, Y; Ye, L; Cui, Y; Yang, G; Yang, W; Wang, J; Hu, J; Gu, W; Shi, C; Huang, H; Wang, C

2017-08-24

Rotavirus-related diarrhoea is considered one of the most important diseases in field animal production. In addition to the classic vaccine strategy, a number of studies have utilised probiotics, such as Lactobacillus rhamnosus GG (LGG), to prevent rotavirus-induced diarrhoea. Although it has been partially revealed that Toll-like receptors (TLRs) are involved in the LGG-mediated protection against rotavirus infection, the details of the underlying immunologic mechanisms remain largely unknown. In this study, three-to-four-week-old female BALB/c mice were divided into three groups and orally administered phosphate buffered saline (PBS), PBS plus rotavirus or LGG plus rotavirus, respectively. The differentiation and maturation of dendritic cells (DCs) were then determined by FACS, the expression levels of TLR-3 and nuclear factor kappa beta (NF-κB) were evaluated using real time PCR, and the production of inflammatory cytokines in mesenteric lymph nodes (MLNs) were determined by ELISA. The results demonstrated that rotavirus infection significantly increased the percentage of CD11c + CD11b + CD8a - DCs and decreased the percentage of CD11c + CD11b - CD8a + DCs in MLNs. By contrast, the presence of LGG significantly decreased the percentage of CD11c + CD11b + CD8a - DCs and increased the percentage of CD11c + CD11b - CD8a + DCs, which indicates that the differentiation of DCs is involved in the protective effects of LGG. Rotavirus infection also resulted in the increased expression of surface markers such as CD40, CD80 and MHC-II in DCs, and the administration of LGG significantly increased the expression level further. The mRNA levels of TLR-3 and NF-κB in the intestine and MLNs were also significantly increased in the presence of rotavirus, which was further increased in the presence of LGG. The production of inflammatory cytokines was also determined, and the results showed that rotavirus caused the increased production of interleukin (IL)-12 and tumour necrosis factor alpha; this effect was further enhanced by LGG. Meanwhile, although rotavirus infection led to the increased production of IL-6 and IL-10, the presence of LGG significantly decreased the mRNA levels of these cytokines. By contrast, rotavirus infection resulted in the decreased production of interferon gamma (IFN-γ), and the administration of LGG significantly increased the levels of IFN-γ. Taken together, the protective effects of LGG were partially due to the modulation of the differentiation and maturation of DCs, the increased production of TLR-3 and NF-κB, and the modulation of inflammatory cytokines.

Ribbon synapses compute temporal contrast and encode luminance in retinal rod bipolar cells

PubMed Central

Oesch, Nicholas W.; Diamond, Jeffrey S.

2011-01-01

Contrast is computed throughout the nervous system to encode changing inputs efficiently. The retina encodes luminance and contrast over a wide range of visual conditions and so must adapt its responses to maintain sensitivity and avoid saturation. Here we show how one type of adaptation allows individual synapses to compute contrast and encode luminance in biphasic responses to step changes in light levels. Light-evoked depletion of the readily releasable vesicle pool (RRP) at rod bipolar cell (RBC) ribbon synapses in rat retina limits the dynamic range available to encode transient but not sustained responses, thereby allowing the transient and sustained components of release to compute temporal contrast and encode mean light levels, respectively. A release/replenishment model shows that a single, homogeneous pool of synaptic vesicles is sufficient to generate this behavior and reveals that the dominant mechanism shaping the biphasic contrast/luminance response is the partial depletion of the RRP. PMID:22019730

Effects of color combination and ambient illumination on visual perception time with TFT-LCD.

PubMed

Lin, Chin-Chiuan; Huang, Kuo-Chen

2009-10-01

An empirical study was carried out to examine the effects of color combination and ambient illumination on visual perception time using TFT-LCD. The effect of color combination was broken down into two subfactors, luminance contrast ratio and chromaticity contrast. Analysis indicated that the luminance contrast ratio and ambient illumination had significant, though small effects on visual perception. Visual perception time was better at high luminance contrast ratio than at low luminance contrast ratio. Visual perception time under normal ambient illumination was better than at other ambient illumination levels, although the stimulus color had a confounding effect on visual perception time. In general, visual perception time was better for the primary colors than the middle-point colors. Based on the results, normal ambient illumination level and high luminance contrast ratio seemed to be the optimal choice for design of workplace with video display terminals TFT-LCD.

The potential use of biomarkers in predicting contrast-induced acute kidney injury

PubMed Central

Andreucci, Michele; Faga, Teresa; Riccio, Eleonora; Sabbatini, Massimo; Pisani, Antonio; Michael, Ashour

2016-01-01

Contrast-induced acute kidney injury (CI-AKI) is a problem associated with the use of iodinated contrast media, causing kidney dysfunction in patients with preexisting renal failure. It accounts for 12% of all hospital-acquired kidney failure and increases the length of hospitalization, a situation that is worsening with increasing numbers of patients with comorbidities, including those requiring cardiovascular interventional procedures. So far, its diagnosis has relied upon the rise in creatinine levels, which is a late marker of kidney damage and is believed to be inadequate. Therefore, there is an urgent need for biomarkers that can detect CI-AKI sooner and more reliably. In recent years, many new biomarkers have been characterized for AKI, and these are discussed particularly with their use in known CI-AKI models and studies and include neutrophil gelatinase-associated lipocalin, cystatin C (Cys-C), kidney injury molecule-1, interleukin-18, N-acetyl-β-d-glucosaminidase, and L-type fatty acid-binding protein (L-FABP). The potential of miRNA and metabolomic technology is also mentioned. Early detection of CI-AKI may lead to early intervention and therefore improve patient outcome, and in future any one or a combination of several of these markers together with development in technology for their analysis may prove effective in this respect. PMID:27672338

Differential effects of eNOS uncoupling on conduit and small arteries in GTP-cyclohydrolase I-deficient hph-1 mice.

PubMed

d'Uscio, Livius V; Smith, Leslie A; Katusic, Zvonimir S

2011-12-01

In the present study, we used the hph-1 mouse, which displays GTP-cyclohydrolase I (GTPCH I) deficiency, to test the hypothesis that loss of tetrahydrobiopterin (BH(4)) in conduit and small arteries activates compensatory mechanisms designed to protect vascular wall from oxidative stress induced by uncoupling of endothelial nitric oxide synthase (eNOS). Both GTPCH I activity and BH(4) levels were reduced in the aortas and small mesenteric arteries of hph-1 mice. However, the BH(4)-to-7,8-dihydrobiopterin ratio was significantly reduced only in hph-1 aortas. Furthermore, superoxide anion and 3-nitrotyrosine production were significantly enhanced in aortas but not in small mesenteric arteries of hph-1 mice. In contrast to the aorta, protein expression of copper- and zinc-containing superoxide dismutase (CuZnSOD) was significantly increased in small mesenteric arteries of hph-1 mice. Protein expression of catalase was increased in both aortas and small mesenteric arteries of hph-1 mice. Further analysis of endothelial nitric oxide synthase (eNOS)/cyclic guanosine monophosphate (cGMP) signaling demonstrated that protein expression of phosphorylated Ser(1177)-eNOS as well as basal cGMP levels and hydrogen peroxide was increased in hph-1 aortas. Increased production of hydrogen peroxide in hph-1 mice aortas appears to be the most likely mechanism responsible for phosphorylation of eNOS and elevation of cGMP. In contrast, upregulation of CuZnSOD and catalase in resistance arteries is sufficient to protect vascular tissue from increased production of reactive oxygen species generated by uncoupling of eNOS. The results of our study suggest that anatomical origin determines the ability of vessel wall to cope with oxidative stress induced by uncoupling of eNOS.

Reduced inflammatory response and increased microcirculatory disturbances during hepatic ischemia-reperfusion injury in steatotic livers of ob/ob mice

PubMed Central

Hasegawa, Tadashi; Ito, Yoshiya; Wijeweera, Jayanthika; Liu, Jie; Malle, Ernst; Farhood, Anwar; McCuskey, Robert S.; Jaeschke, Hartmut

2016-01-01

Steatosis is a major risk factor for complications after liver surgery. Since neutrophil cytotoxicity is critical for ischemia-reperfusion injury in normal livers, the aim of the present study was to evaluate whether an exaggerated inflammatory response could cause the increased injury in steatotic livers. In C57Bl/6 mice, 60 min of warm hepatic ischemia triggered a gradual increase in hepatic neutrophil accumulation during reperfusion with peak levels of 100-fold over baseline at 12 h of reperfusion. Neutrophil extravasation and a specific neutrophil-induced oxidant stress (immunostaining for hypochlorous acid-modified epitopes) started at 6 h of reperfusion and peaked at 12–24 h. Ob/ob mice, which had a severe macrovesicular steatosis, suffered significantly higher injury (alanine transaminase activity: 18,000 ± 2,100 U/l; 65% necrosis) compared with lean littermates (alanine transaminase activity: 4,900 ± 720 U/l; 24% necrosis) at 6 h of reperfusion. However, 62% fewer neutrophils accumulated in steatotic livers. This correlated with an attenuated increase in mRNA levels of several proinflammatory genes in ob/ob mice during reperfusion. In contrast, sham-operated ob/ob mice had a 50% reduction in liver blood flow and 35% fewer functional sinusoids compared with lean littermates. These deficiencies in liver blood flow and the microcirculation were further aggravated only in ob/ob mice during reperfusion. The attenuated inflammatory response and reduced neutrophil-induced oxidant stress observed in steatotic livers during reperfusion cannot be responsible for the dramatically increased injury in ob/ob mice. In contrast, the aggravated injury appears to be mediated by ischemic necrosis due to massive impairment of blood and oxygen supply in the steatotic livers. PMID:17307725

Macrophages clear refrigerator storage-damaged red blood cells and subsequently secrete cytokines in vivo, but not in vitro, in a murine model.

PubMed

Wojczyk, Boguslaw S; Kim, Nina; Bandyopadhyay, Sheila; Francis, Richard O; Zimring, James C; Hod, Eldad A; Spitalnik, Steven L

2014-12-01

In mice, refrigerator-stored red blood cells (RBCs) are cleared by extravascular hemolysis and induce cytokine production. To enhance understanding of this phenomenon, we sought to model it in vitro. Ingestion of refrigerator-stored murine RBCs and subsequent cytokine production were studied using J774A.1 mouse macrophage cells and primary murine splenic macrophages. Wild-type and Ccl2-GFP reporter mice were used for RBC clearance in vivo. Although J774A.1 cells and primary macrophages preferentially ingested refrigerator-stored RBCs in vitro, compared to freshly isolated RBCs, neither produced increased cytokines after erythrophagocytosis. In contrast, phagocytosis of refrigerator-stored RBCs in vivo induced increases in circulating monocyte chemoattractant protein-1 (MCP-1) and keratinocyte chemoattractant (KC) and correspondingly increased mRNA levels in mouse spleen and liver. In the spleen, these were predominantly expressed by CD11b+ cells. Using Ccl2-GFP reporter mice, the predominant splenic population responsible for MCP-1 mRNA production was tissue-resident macrophages (i.e., CD45+, CD11b+, F4/80+, Ly6c+, and CD11c(low) cells). J774A.1 cells and primary macrophages selectively ingested refrigerator-stored RBCs by phagocytosis. Although cytokine expression was not enhanced, this approach could be used to identify the relevant receptor-ligand combination(s). In contrast, cytokine levels increased after phagocytosis of refrigerator-stored RBCs in vivo. These were primarily cleared in the liver and spleen, which demonstrated increased MCP-1 and KC mRNA expression. Finally, in mouse spleen, tissue-resident macrophages were predominantly involved in MCP-1 mRNA production. The differences between cytokine production in vitro and in vivo are not yet well understood. © 2014 AABB.

Macrophages clear refrigerator storage-damaged RBCs and subsequently secrete cytokines in vivo, but not in vitro, in a murine model

PubMed Central

Wojczyk, Boguslaw S.; Kim, Nina; Bandyopadhyay, Sheila; Francis, Richard O.; Zimring, James C.; Hod, Eldad A.; Spitalnik, Steven L.

2014-01-01

BACKGROUND In mice, refrigerator-stored red blood cells (RBCs) are cleared by extravascular hemolysis and induce cytokine production. To enhance understanding of this phenomenon, we sought to model it in vitro. STUDY DESIGN AND METHODS Ingestion of refrigerator-stored murine RBCs and subsequent cytokine production were studied using J774A.1 mouse macrophage cells and primary murine splenic macrophages. Wild-type and Ccl2-GFP-reporter mice were used for RBC clearance in vivo. RESULTS Although J774A.1 cells and primary macrophages preferentially ingested refrigerator-stored RBCs in vitro, as compared to freshly-isolated RBCs, neither produced increased cytokines following erythrophagocytosis. In contrast, phagocytosis of refrigerator-stored RBCs in vivo induced increases in circulating monocyte chemoattractant protein-1 (MCP-1) and keratinocyte chemoattractant (KC), and correspondingly increased mRNA levels in mouse spleen and liver. In the spleen, these were predominantly expressed by CD11b+ cells. Using Ccl2-GFP-reporter mice, the predominant splenic population responsible for MCP-1 mRNA production were tissue-resident macrophages (i.e., CD45+, CD11b+, F4/80+, Ly6c+, CD11clow cells). CONCLUSION J774A.1 cells and primary macrophages selectively ingested refrigerator-stored RBCs by phagocytosis. Although cytokine expression was not enhanced, this approach could be used to identify the relevant receptor-ligand combination(s). In contrast, cytokine levels increased following phagocytosis of refrigerator-stored RBCs in vivo. These were primarily cleared in the liver and spleen, which demonstrated increased MCP-1 and KC mRNA expression. Finally, in mouse spleen, tissue-resident macrophages were predominantly involved in MCP-1 mRNA production. The differences between cytokine production in vitro and in vivo are not yet well understood. PMID:25041478

Differential changes in sphingolipids between TNF-induced necroptosis and apoptosis in U937 cells and necroptosis-resistant sublines.

PubMed

Sawai, Hirofumi; Ogiso, Hideo; Okazaki, Toshiro

2015-09-01

Differential changes in various sphingolipids between TNF-induced necroptosis and apoptosis were investigated using liquid chromatography-tandem mass spectrometry. A marked increase in d18:1/16:0 ceramide was detected in U937 cells treated with TNF in the presence of Z-VAD-fmk (VAD). The level of d18:1/16:0 ceramide in necroptosis was almost twice as high as that in apoptosis after 4h, while an increase in PI-positive cells was observed only in necroptosis within 4h. Necroptosis-resistant U937 (UNR) sublines were established to more clearly discriminate between necroptosis and apoptosis. All three UNR sublines were almost completely resistant to the treatment with TNF/VAD, but were as sensitive to TNF-induced apoptosis as parental cells. The expression of RIP3, a pivotal kinase in necroptosis, was lost in all three UNR sublines. In contrast with the large increase in ceramide levels in TNF/VAD-treated parental cells, they were only slightly increased in UNR cells. Although intracellular levels of reactive oxygen species (ROS) were elevated in both necroptosis and apoptosis, the treatment with butylated hydroxyanisole, an antioxidant, significantly inhibited increases in ceramide levels and PI-positive cells only in necroptosis. These results implicate that the ROS-induced large increase in ceramide levels may play a role in plasma membrane permeabilization in TNF-induced necroptosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

N-Acetyl-L-cysteine protects thyroid cells against DNA damage induced by external and internal irradiation.

PubMed

Kurashige, Tomomi; Shimamura, Mika; Nagayama, Yuji

2017-11-01

We evaluated the effect of the antioxidant N-acetyl-L-cysteine (NAC) on the levels of reactive oxygen species (ROS), DNA double strand breaks (DSB) and micronuclei (MN) induced by internal and external irradiation using a rat thyroid cell line PCCL3. In internal irradiation experiments, ROS and DSB levels increased immediately after 131 I addition and then gradually declined, resulting in very high levels of MN at 24 and 48 h. NAC administration both pre- and also post- 131 I addition suppressed ROS, DSB and MN. In external irradiation experiments with a low dose (0.5 Gy), ROS and DSB increased shortly and could be prevented by NAC administration pre-, but not post-irradiation. In contrast, external irradiation with a high dose (5 Gy) increased ROS and DSB in a bimodal way: ROS and DSB levels increased immediately after irradiation, quickly returned to the basal levels and gradually rose again after >24 h. The second phase was in parallel with an increase in 4-hydroxy-2-nonenal. The number of MN induced by the second wave of ROS/DSB elevations was much higher than that by the first peak. In this situation, NAC administered pre- and post-irradiation comparably suppressed MN induced by a delayed ROS elevation. In conclusion, a prolonged ROS increase during internal irradiation and a delayed ROS increase after external irradiation with a high dose caused serious DNA damage, which were efficiently prevented by NAC. Thus, NAC administration even both after internal or external irradiation prevents ROS increase and eventual DNA damage.

High levels of the Mps1 checkpoint protein are protective of aneuploidy in breast cancer cells

PubMed Central

Daniel, Jewel; Coulter, Jonathan; Woo, Ju-Hyung; Wilsbach, Kathleen; Gabrielson, Edward

2011-01-01

Most human cancers are aneuploid and have chromosomal instability, which contrasts to the inability of human cells to normally tolerate aneuploidy. Noting that aneuploidy in human breast cancer correlates with increased expression levels of the Mps1 checkpoint gene, we investigated whether these high levels of Mps1 contribute to the ability of breast cancer cells to tolerate this aneuploidy. Reducing Mps1 levels in cultured human breast cancer cells by RNAi resulted in aberrant mitoses, induction of apoptosis, and decreased ability of human breast cancer cells to grow as xenografts in nude mice. Remarkably, breast cancer cells that survive reductions in levels of Mps1 have relatively less aneuploidy, as measured by copies of specific chromosomes, compared with cells that have constitutively high levels of Mps1. Thus, high levels of Mps1 in breast cancer cells likely contribute to these cells tolerating aneuploidy. PMID:21402910

High levels of the Mps1 checkpoint protein are protective of aneuploidy in breast cancer cells.

PubMed

Daniel, Jewel; Coulter, Jonathan; Woo, Ju-Hyung; Wilsbach, Kathleen; Gabrielson, Edward

2011-03-29

Most human cancers are aneuploid and have chromosomal instability, which contrasts to the inability of human cells to normally tolerate aneuploidy. Noting that aneuploidy in human breast cancer correlates with increased expression levels of the Mps1 checkpoint gene, we investigated whether these high levels of Mps1 contribute to the ability of breast cancer cells to tolerate this aneuploidy. Reducing Mps1 levels in cultured human breast cancer cells by RNAi resulted in aberrant mitoses, induction of apoptosis, and decreased ability of human breast cancer cells to grow as xenografts in nude mice. Remarkably, breast cancer cells that survive reductions in levels of Mps1 have relatively less aneuploidy, as measured by copies of specific chromosomes, compared with cells that have constitutively high levels of Mps1. Thus, high levels of Mps1 in breast cancer cells likely contribute to these cells tolerating aneuploidy.

Elevated Expression of Osteopontin May Be Related to Adipose Tissue Macrophage Accumulation and Liver Steatosis in Morbid Obesity

PubMed Central

Bertola, Adeline; Deveaux, Vanessa; Bonnafous, Stéphanie; Rousseau, Déborah; Anty, Rodolphe; Wakkach, Abdelilah; Dahman, Moncef; Tordjman, Joan; Clément, Karine; McQuaid, Siobhán E.; Frayn, Keith N.; Huet, Pierre-Michel; Gugenheim, Jean; Lotersztajn, Sophie; Le Marchand-Brustel, Yannick; Tran, Albert; Gual, Philippe

2009-01-01

OBJECTIVE—Osteopontin (OPN) plays an important role in the development of insulin resistance and liver complications in dietary murine models. We aimed to determine the expression pattern of OPN and its receptor CD44 in obese patients and mice according to insulin resistance and liver steatosis. RESEARCH DESIGN AND METHODS—OPN and CD44 expressions were studied in 52 morbidly obese patients and in mice. Cellular studies were performed in HepG2 cells. RESULTS—Hepatic OPN and CD44 expressions were strongly correlated with liver steatosis and insulin resistance in obese patients and mice. This increased OPN expression could be due to the accumulation of triglycerides, since fat loading in HepG2 promotes OPN expression. In contrast, OPN expression in adipose tissue (AT) was enhanced independently of insulin resistance and hepatic steatosis in obese patients. The elevated OPN expression in AT was paralleled with the AT macrophage infiltration, and both phenomena were reversed after weight loss. The circulating OPN level was slightly elevated in obese patients and was not related to liver steatosis. Further, AT did not appear to secrete OPN. In contrast, bariatric surgery–induced weight loss induced a strong increase in circulating OPN. CONCLUSIONS—The modestly elevated circulating OPN levels in morbidly obese patients were not related to liver steatosis and did not appear to result from adipose tissue secretion. In subcutaneous AT, expression of OPN was directly related to macrophage accumulation independently from liver complications. In contrast, hepatic OPN and CD44 expressions were related to insulin resistance and steatosis, suggesting their local implication in the progression of liver injury. PMID:18952835

Improvements to image quality using hybrid and model-based iterative reconstructions: a phantom study.

PubMed

Aurumskjöld, Marie-Louise; Ydström, Kristina; Tingberg, Anders; Söderberg, Marcus

2017-01-01

The number of computed tomography (CT) examinations is increasing and leading to an increase in total patient exposure. It is therefore important to optimize CT scan imaging conditions in order to reduce the radiation dose. The introduction of iterative reconstruction methods has enabled an improvement in image quality and a reduction in radiation dose. To investigate how image quality depends on reconstruction method and to discuss patient dose reduction resulting from the use of hybrid and model-based iterative reconstruction. An image quality phantom (Catphan® 600) and an anthropomorphic torso phantom were examined on a Philips Brilliance iCT. The image quality was evaluated in terms of CT numbers, noise, noise power spectra (NPS), contrast-to-noise ratio (CNR), low-contrast resolution, and spatial resolution for different scan parameters and dose levels. The images were reconstructed using filtered back projection (FBP) and different settings of hybrid (iDose 4 ) and model-based (IMR) iterative reconstruction methods. iDose 4 decreased the noise by 15-45% compared with FBP depending on the level of iDose 4 . The IMR reduced the noise even further, by 60-75% compared to FBP. The results are independent of dose. The NPS showed changes in the noise distribution for different reconstruction methods. The low-contrast resolution and CNR were improved with iDose 4 , and the improvement was even greater with IMR. There is great potential to reduce noise and thereby improve image quality by using hybrid or, in particular, model-based iterative reconstruction methods, or to lower radiation dose and maintain image quality. © The Foundation Acta Radiologica 2016.

Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism

PubMed Central

Kissoudis, Christos; Sunarti, Sri; van de Wiel, Clemens; Visser, Richard G.F.; van der Linden, C. Gerard; Bai, Yuling

2016-01-01

Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of different levels of salt stress ranging from mild to severe (50, 100, and 150mM NaCl) on powdery mildew resistance and overall performance of tomato introgression lines with contrasting levels of partial resistance, as well as near-isogenic lines (NILs) carrying the resistance gene Ol-1 (associated with a slow hypersensitivity response; HR), ol-2 (an mlo mutant associated with papilla formation), and Ol-4 (an R gene associated with a fast HR). Powdery mildew resistance was affected by salt stress in a genotype- and stress intensity-dependent manner. In susceptible and partial resistant lines, increased susceptibility was observed under mild salt stress (50mM) which was accompanied by accelerated cell death-like senescence. In contrast, severe salt stress (150mM) reduced disease symptoms. Na+ and Cl− accumulation in the leaves was linearly related to the decreased pathogen symptoms under severe stress. In contrast, complete resistance mediated by ol-2 and Ol-4 was unaffected under all treatment combinations, and was associated with a decreased growth penalty. Increased susceptibility and senescence under combined stress in NIL-Ol-1 was associated with the induction of ethylene and jasmonic acid pathway genes and the cell wall invertase gene LIN6. These results highlight the significance of stress severity and resistance type on the plant’s performance under the combination of abiotic and biotic stress. PMID:27436279

fMRI neurofeedback of amygdala response to aversive stimuli enhances prefrontal-limbic brain connectivity.

PubMed

Paret, Christian; Ruf, Matthias; Gerchen, Martin Fungisai; Kluetsch, Rosemarie; Demirakca, Traute; Jungkunz, Martin; Bertsch, Katja; Schmahl, Christian; Ende, Gabriele

2016-01-15

Down-regulation of the amygdala with real-time fMRI neurofeedback (rtfMRI NF) potentially allows targeting brain circuits of emotion processing and may involve prefrontal-limbic networks underlying effective emotion regulation. Little research has been dedicated to the effect of rtfMRI NF on the functional connectivity of the amygdala and connectivity patterns in amygdala down-regulation with neurofeedback have not been addressed yet. Using psychophysiological interaction analysis of fMRI data, we present evidence that voluntary amygdala down-regulation by rtfMRI NF while viewing aversive pictures was associated with increased connectivity of the right amygdala with the ventromedial prefrontal cortex (vmPFC) in healthy subjects (N=16). In contrast, a control group (N=16) receiving sham feedback did not alter amygdala connectivity (Group×Condition t-contrast: p<.05 at cluster-level). Task-dependent increases in amygdala-vmPFC connectivity were predicted by picture arousal (β=.59, p<.05). A dynamic causal modeling analysis with Bayesian model selection aimed at further characterizing the underlying causal structure and favored a bottom-up model assuming predominant information flow from the amygdala to the vmPFC (xp=.90). The results were complemented by the observation of task-dependent alterations in functional connectivity of the vmPFC with the visual cortex and the ventrolateral PFC in the experimental group (Condition t-contrast: p<.05 at cluster-level). Taken together, the results underscore the potential of amygdala fMRI neurofeedback to influence functional connectivity in key networks of emotion processing and regulation. This may be beneficial for patients suffering from severe emotion dysregulation by improving neural self-regulation. Copyright © 2015 Elsevier Inc. All rights reserved.

Elevated Squamous Cell Carcinoma Antigen, Cytokeratin 19 Fragment, and Carcinoembryonic Antigen Levels in Diabetic Nephropathy

PubMed Central

Chen, Jianzhong; Zhang, Bin; Chen, Qingguang; Qiu, Yan; Luo, Qian; Gen, Yanna; Meng, Jiali

2017-01-01

Objective We aimed to explore whether squamous cell carcinoma antigen (SCC), cytokeratin 19 fragment (Cyfra21-1), neuron-specific enolase (NSE), and carcinoembryonic antigen (CEA) are elevated in diabetic nephropathy (DN) and the association between urinary albumin-to-creatinine ratio (UACR) and tumor markers in diabetic patients. Methods Nondialysis patients with diabetes (n = 261) and 90 healthy controls were enrolled. DN was defined as an UACR ≥ 30 mg/g in the absence of a urinary tract infection or other renal abnormalities. Results Patients with DN had significantly higher serum SCC, Cyfra21-1, and CEA levels than those with normoalbuminuria and healthy controls. The rates of positive SCC, Cyfra21-1, and CEA significantly increased with increasing urinary albumin excretion (all P for trend < 0.001). In contrast, NSE was not affected by DN. SCC, Cyfra21-1, and CEA were significantly and positively correlated with UACR. In logistic regression, after multivariable adjustment, increased UACR was associated with increased odds ratio of elevated tumor marker levels (all P for trend < 0.05). Conclusions Serum levels of SCC, Cyfra21-1, and CEA are markedly increased with increasing urinary albumin excretion, which affects the specificity for diagnosis for lung cancer. Appropriate interpretation of tumor markers in diabetic patients is mandatory to avoid unnecessary and even hazardous biopsies. PMID:28744310

Mitochondrial fusion increases the mitochondrial DNA copy number in budding yeast.

PubMed

Hori, Akiko; Yoshida, Minoru; Ling, Feng

2011-05-01

Mitochondrial fusion plays an important role in mitochondrial DNA (mtDNA) maintenance, although the underlying mechanisms are unclear. In budding yeast, certain levels of reactive oxygen species (ROS) can promote recombination-mediated mtDNA replication, and mtDNA maintenance depends on the homologous DNA pairing protein Mhr1. Here, we show that the fusion of isolated yeast mitochondria, which can be monitored by the bimolecular fluorescence complementation-derived green fluorescent protein (GFP) fluorescence, increases the mtDNA copy number in a manner dependent on Mhr1. The fusion event, accompanied by the degradation of dissociated electron transport chain complex IV and transient reductions in the complex IV subunits by the inner membrane AAA proteases such as Yme1, increases ROS levels. Analysis of the initial stage of mitochondrial fusion in early log-phase cells produced similar results. Moreover, higher ROS levels in mitochondrial fusion-deficient mutant cells increased the amount of newly synthesized mtDNA, resulting in increases in the mtDNA copy number. In contrast, reducing ROS levels in yme1 null mutant cells significantly decreased the mtDNA copy number, leading to an increase in cells lacking mtDNA. Our results indicate that mitochondrial fusion induces mtDNA synthesis by facilitating ROS-triggered, recombination-mediated replication and thereby prevents the generation of mitochondria lacking DNA. © 2011 The Authors. Journal compilation © 2011 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

Selective exposure to information: how different modes of decision making affect subsequent confirmatory information processing.

PubMed

Fischer, Peter; Fischer, Julia; Weisweiler, Silke; Frey, Dieter

2010-12-01

We investigated whether different modes of decision making (deliberate, intuitive, distracted) affect subsequent confirmatory processing of decision-consistent and inconsistent information. Participants showed higher levels of confirmatory information processing when they made a deliberate or an intuitive decision versus a decision under distraction (Studies 1 and 2). As soon as participants have a cognitive (i.e., deliberate cognitive analysis) or affective (i.e., intuitive and gut feeling) reason for their decision, the subjective confidence in the validity of their decision increases, which results in increased levels of confirmatory information processing (Study 2). In contrast, when participants are distracted during decision making, they are less certain about the validity of their decision and thus are subsequently more balanced in the processing of decision-relevant information.

Membrane of Functionalized Reduced Graphene Oxide Nanoplates with Angstrom-Level Channels

PubMed Central

Lee, Byeongho; Li, Kunzhou; Yoon, Hong Sik; Yoon, Jeyong; Mok, Yeongbong; Lee, Yan; Lee, Hong H.; Kim, Yong Hyup

2016-01-01

Membranes with atomic level pores or constrictions are valuable for separation and catalysis. We report a graphene-based membrane with an interlayer spacing of 3.7 angstrom (Å). When graphene oxide nanoplates are functionalized and then reduced, the laminated reduced graphene oxide (rGO) nanoplates or functionalized rGO membrane is little affected by an intercalated fluid, and the interlayer spacing of 3.7 Å increases only to 4.4 Å in wetted state, in contrast to the graphene oxide (GO) membrane whose interlayer spacing increases from 9 Å to 13 Å in wetted state. When applied to ion separation, this membrane reduced the permeation rate of small ions such as K+ and Na+ by three orders of magnitude compared to the GO membrane. PMID:27306853

Comparison of potential risks of lactic acidosis induction by biguanides in rats.

PubMed

Bando, Kiyoko; Ochiai, Shoko; Kunimatsu, Takeshi; Deguchi, Jiro; Kimura, Juki; Funabashi, Hitoshi; Seki, Takaki

2010-10-01

Lactic acidosis has been considered to be a side effect of some biguanides, after phenformin was withdrawn from the market because of its association with lactic acidosis. The potential of lactic acidosis induced by biguanides at human therapeutic exposure levels, however, has not been examined. Then, we compared the risk of lactic acid at doses providing exposure levels comparable to human therapeutic doses. Metformin and phenformin were orally administered to rats for up to 28 days, and plasma drug concentrations and blood lactic acid levels were examined. Metformin did not elevate lactic acid levels at the dose corresponding to higher systemic drug exposure than human therapeutic level, even for repeated doses. In contrast, phenformin elevated lactic acid levels at the dose corresponding to lower exposure than human therapeutic level, and sustained high levels were observed up to 24h post-dose; furthermore, these changes were enhanced by repeated doses. Direct comparison at each rat equivalent dose clearly indicated that lactic acid levels of phenformin were higher than those of metformin. These non-clinical findings suggest that metformin dose not increase lactic acid levels like phenformin does, and therefore may not increase the risk for lactic acidosis at human therapeutic exposure level. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Interoception drives increased rational decision-making in meditators playing the ultimatum game.

PubMed

Kirk, Ulrich; Downar, Jonathan; Montague, P Read

2011-01-01

Human decision-making is often conceptualized as a competition between cognitive and emotional processes in the brain. Deviations from rational processes are believed to derive from inclusion of emotional factors in decision-making. Here, we investigate whether experienced Buddhist meditators are better equipped to regulate emotional processes compared with controls during economic decision-making in the Ultimatum Game. We show that meditators accept unfair offers on more than half of the trials, whereas controls only accept unfair offers on one-quarter of the trials. By applying fMRI we show that controls recruit the anterior insula during unfair offers. Such responses are powerful predictors of rejecting offers in social interaction. By contrast, meditators display attenuated activity in high-level emotional representations of the anterior insula and increased activity in the low-level interoceptive representations of the posterior insula. In addition we show that a subset of control participants who play rationally (i.e., accepts >85% unfair offers) recruits the dorsolateral prefrontal cortex presumably reflecting increased cognitive demands, whereas rational meditators by contrast display elevated activity in the somatosensory cortex and posterior superior temporal cortex. In summary, when assessing unfairness in the Ultimatum Game, meditators activate a different network of brain areas compared with controls enabling them to uncouple negative emotional reactions from their behavior. These findings highlight the clinically and socially important possibility that sustained training in mindfulness meditation may impact distinct domains of human decision-making.

Monitoring the Wet-Heat Inactivation Dynamics of Single Spores of Bacillus Species by Using Raman Tweezers, Differential Interference Contrast Microscopy, and Nucleic Acid Dye Fluorescence Microscopy▿

PubMed Central

Zhang, Pengfei; Kong, Lingbo; Wang, Guiwen; Setlow, Peter; Li, Yong-qing

2011-01-01

Dynamic processes during wet-heat treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis at 80 to 90°C were investigated using dual-trap Raman spectroscopy, differential interference contrast (DIC) microscopy, and nucleic acid stain (SYTO 16) fluorescence microscopy. During spore wet-heat treatment, while the spores' 1:1 chelate of Ca2+ with dipicolinic acid (CaDPA) was released rapidly at a highly variable time Tlag, the levels of spore nucleic acids remained nearly unchanged, and the Tlag times for individual spores from the same preparation were increased somewhat as spore levels of CaDPA increased. The brightness of the spores' DIC image decreased by ∼50% in parallel with CaDPA release, and there was no spore cortex hydrolysis observed. The lateral diameters of the spores' DIC image and SYTO 16 fluorescence image also decreased in parallel with CaDPA release. The SYTO 16 fluorescence intensity began to increase during wet-heat treatment at a time before Tlag and reached maximum at a time slightly later than Trelease. However, the fluorescence intensities of wet-heat-inactivated spores were ∼15-fold lower than those of nutrient-germinated spores, and this low SYTO 16 fluorescence intensity may be due in part to the low permeability of the dormant spores' inner membranes to SYTO 16 and in part to nucleic acid denaturation during the wet-heat treatment. PMID:21602365

Profound differences between humans and rodents in the ability to concentrate salivary nitrate: Implications for translational research.

PubMed

Montenegro, Marcelo F; Sundqvist, Michaela L; Nihlén, Carina; Hezel, Michael; Carlström, Mattias; Weitzberg, Eddie; Lundberg, Jon O

2016-12-01

In humans dietary circulating nitrate accumulates rapidly in saliva through active transport in the salivary glands. By this mechanism resulting salivary nitrate concentrations are 10-20 times higher than in plasma. In the oral cavity nitrate is reduced by commensal bacteria to nitrite, which is subsequently swallowed and further metabolized to nitric oxide (NO) and other bioactive nitrogen oxides in blood and tissues. This entero-salivary circulation of nitrate is central in the various NO-like effects observed after ingestion of inorganic nitrate. The very same system has also been the focus of toxicologists studying potential carcinogenic effects of nitrite-dependent nitrosamine formation. Whether active transport of nitrate and accumulation in saliva occurs also in rodents is not entirely clear. Here we measured salivary and plasma levels of nitrate and nitrite in humans, rats and mice after administration of a standardized dose of nitrate. After oral (humans) or intraperitoneal (rodents) sodium nitrate administration (0.1mmol/kg), plasma nitrate levels increased markedly reaching ~300µM in all three species. In humans ingestion of nitrate was followed by a rapid increase in salivary nitrate to >6000µM, ie 20 times higher than those found in plasma. In contrast, in rats and mice salivary nitrate concentrations never exceeded the levels in plasma. Nitrite levels in saliva and plasma followed a similar pattern, ie marked increases in humans but modest elevations in rodents. In mice there was also no accumulation of nitrate in the salivary glands as measured directly in whole glands obtained after acute administration of nitrate. This study suggests that in contrast to humans, rats and mice do not actively concentrate circulating nitrate in saliva. These apparent species differences should be taken into consideration when studying the nitrate-nitrite-nitric oxide pathway in rodents, when calculating doses, exploring physiological, therapeutic and toxicological effects and comparing with human data. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

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

Stone, J.P.; Holtsman, S.; Shellabarger, C.J.

Pellets containing 5 mg (/sup 3/H) diethylstilbestrol (DES) and 15 mg cholesterol were implanted S.C. in 84-day-old female Sprague-Dawley (S-D) and ACl rats. DES was released from the implanted pellets exponentially, and the release was not significantly different in S-D rats than in ACl rats. No mammary tumors developed in any treated or untreated S-D rats. In contrast, 90% of the DES-treated ACl rats developed mammary adenocarcinomas. A significant increase in the weight of the pituitary was noted in DES-treated ACl rats. The pituitarities of the treated ACl rats were 2 to 7 times as heavy as were controls, andmore » plasma prolactin levels were 10 to 40 times higher than in controls. In contrast, the pituitaries of treated S-D rats did not significantly increase in weight, and plasma prolactin levels were only 3 to 5 times higher than controls. The uteri of treated S-D rats were significantly heavier than those of control rats and contained large amounts of fluid. This effect was not seen in ACl rats. Although the release of DES from the implanted pellet was essentially the same in ACl and S-D rats, three distinctive strain differences in response to DES were noted: mammary adenocarcinomas were found only in treated ACl rats; pituitary prolactin-cell adenomas and associated elevated plasma prolactins levels were seen only in treated ACl rats; and pyometritis was induced only in treated S-D rats. Mammary adenocarcinomas and prolactin-cell adenoma responses in the treated ACl rats appear to be correlated with the increasing levels of plasma prolactin. This study demonstrates that the prolonged estrogen treatment of ACl and S-D female rats produces distinctly different mammary and pituitary neoplastic responses. This disparity in neoplastic responses appears to be reflected in the difference of degree to which the hypophysical prolactin cells are stimulated to grow and secrete hormone.« less

Can contrast media increase organ doses in CT examinations? A clinical study.

PubMed

Amato, Ernesto; Salamone, Ignazio; Naso, Serena; Bottari, Antonio; Gaeta, Michele; Blandino, Alfredo

2013-06-01

The purpose of this article is to quantify the CT radiation dose increment in five organs resulting from the administration of iodinated contrast medium. Forty consecutive patients who underwent both un-enhanced and contrast-enhanced thoracoabdominal CT were included in our retrospective study. The dose increase between CT before and after contrast agent administration was evaluated in the portal phase for the thyroid, liver, spleen, pancreas, and kidneys by applying a previously validated method. An increase in radiation dose was noted in all organs studied. Average dose increments were 19% for liver, 71% for kidneys, 33% for spleen and pancreas, and 41% for thyroid. Kidneys exhibited the maximum dose increment, whereas the pancreas showed the widest variance because of the differences in fibro-fatty involution. Finally, thyroids with high attenuation values on unenhanced CT showed a lower Hounsfield unit increase and, thus, a smaller increment in the dose. Our study showed an increase in radiation dose in several parenchymatous tissues on contrast-enhanced CT. Our method allowed us to evaluate the dose increase from the change in attenuation measured in Hounsfield units. Because diagnostic protocols require multiple acquisitions after the contrast agent administration, such a dose increase should be considered when optimizing these protocols.

The pathogenesis of ethanol versus methionine and choline deficient diet-induced liver injury.

PubMed

Gyamfi, Maxwell Afari; Damjanov, Ivan; French, Samuel; Wan, Yu-Jui Yvonne

2008-02-15

The differences and similarities of the pathogenesis of alcoholic (ASH) and non-alcoholic steatohepatitis (NASH) were examined. Mice (six/group) received one of four Lieber-Decarli liquid diets for 6 weeks: (1) paired-fed control diet; (2) control diet with ethanol (ethanol); (3) paired-fed methionine/choline deficient (MCD) diet; and (4) MCD plus ethanol (combination). Hepatotoxicity, histology, and gene expression changes were examined. Both MCD and ethanol induced macrovesicular steatosis. However, the combination diet produced massive steatosis with minor necrosis and inflammation. MCD and combination diets, but not ethanol, induced serum ALT levels by 1.6- and 10-fold, respectively. MCD diet, but not ethanol, also induced serum alkaline phosphatase levels suggesting bile duct injury. Ethanol increased liver fatty acid binding protein (L-FABP) mRNA and protein levels. In contrast, the combination diet decreased L-FABP mRNA and protein levels and increased hepatic free fatty acid and lipid peroxide levels. Ethanol, but not MCD, reduced hepatic S-adenosylmethionine (SAM) and GSH levels. Hepatic TNFalpha protein levels were increased in all treatment groups, however, IL-6, a hepatoprotective cytokine which promotes liver regeneration was increased in ethanol-fed mice (2-fold), but decreased in the combination diet-treated mice. In addition, the combination diet reduced phosphorylated STAT3 and Bcl-2 levels. While MCD diet might cause bile duct injury and cholestasis, ethanol preferentially interferes with the SAM-GSH oxidative stress pathway. The exacerbated liver injury induced by the combination diet might be explained by reduced L-FABP, increased free fatty acids, oxidative stress, and decreased IL-6 protein levels. The combination diet is an efficient model of steatohepatitis.

Accuracy in contouring of small and low contrast lesions: Comparison between diagnostic quality computed tomography scanner and computed tomography simulation scanner-A phantom study

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

Ho, Yick Wing, E-mail: mpr@hksh.com; Wong, Wing Kei Rebecca; Yu, Siu Ki

2012-01-01

To evaluate the accuracy in detection of small and low-contrast regions using a high-definition diagnostic computed tomography (CT) scanner compared with a radiotherapy CT simulation scanner. A custom-made phantom with cylindrical holes of diameters ranging from 2-9 mm was filled with 9 different concentrations of contrast solution. The phantom was scanned using a 16-slice multidetector CT simulation scanner (LightSpeed RT16, General Electric Healthcare, Milwaukee, WI) and a 64-slice high-definition diagnostic CT scanner (Discovery CT750 HD, General Electric Healthcare). The low-contrast regions of interest (ROIs) were delineated automatically upon their full width at half maximum of the CT number profile inmore » Hounsfield units on a treatment planning workstation. Two conformal indexes, CI{sub in}, and CI{sub out}, were calculated to represent the percentage errors of underestimation and overestimation in the automated contours compared with their actual sizes. Summarizing the conformal indexes of different sizes and contrast concentration, the means of CI{sub in} and CI{sub out} for the CT simulation scanner were 33.7% and 60.9%, respectively, and 10.5% and 41.5% were found for the diagnostic CT scanner. The mean differences between the 2 scanners' CI{sub in} and CI{sub out} were shown to be significant with p < 0.001. A descending trend of the index values was observed as the ROI size increases for both scanners, which indicates an improved accuracy when the ROI size increases, whereas no observable trend was found in the contouring accuracy with respect to the contrast levels in this study. Images acquired by the diagnostic CT scanner allow higher accuracy on size estimation compared with the CT simulation scanner in this study. We recommend using a diagnostic CT scanner to scan patients with small lesions (<1 cm in diameter) for radiotherapy treatment planning, especially for those pending for stereotactic radiosurgery in which accurate delineation of small-sized, low-contrast regions is important for dose calculation.« less

Effect of chymosin and salt reduction on the quality of ultrafiltrated white-salted cheese.

PubMed

Al-Otaibi, Mutlag M; Wilbey, R Andrew

2005-05-01

This study demonstrated that both chymosin and salt-in-moisture (SM) were important factors for proteolysis in the manufacture of ultrafiltrated white-salted cheese, with significant effects on water-soluble nitrogen and nitrogen soluble in trichloroacetic acid. In contrast, the levels of free amino acids were not significantly affected by chymosin and salt treatments. The cheeses made, using high levels of chymosin with low SM had lower levels of residual alpha(S1)- and beta-casein at the end of ripening. On texture profile analysis, the hardness and fracturability of the cheeses significantly increased with SM and decreased during ripening. Increases in chymosin significantly contributed to the overall weakening of the structure throughout ripening. Bitter flavour was detected after 12 weeks in the cheese made with the higher chymosin level and lower SM, which could be the result of accumulation of gamma-casein fractions. The sensory data indicated that the hedonic responses for low chymosin with low SM cheeses were good and acceptable in flavour, which may be due to the moderate levels of proteolysis products.

The response of MRI contrast parameters in in vitro tissues and tissue mimicking phantoms to fractionation by histotripsy

NASA Astrophysics Data System (ADS)

Allen, Steven P.; Vlaisavljevich, Eli; Shi, Jiaqi; Hernandez-Garcia, Luis; Cain, Charles A.; Xu, Zhen; Hall, Timothy L.

2017-09-01

Histotripsy is a non-invasive, focused ultrasound lesioning technique that can ablate precise volumes of soft tissue using a novel mechanical fractionation mechanism. Previous research suggests that magnetic resonance imaging (MRI) may be a sensitive image-based feedback mechanism for histotripsy. However, there are insufficient data to form some unified understanding of the response of the MR contrast mechanisms in tissues to histotripsy. In this paper, we investigate the response of the MR contrast parameters R1, R2, and the apparent diffusion coefficient (ADC) to various treatment levels of histotripsy in in vitro porcine liver, kidney, muscle, and blood clot as well in formulations of bovine red blood cells suspended in agar gel. We also make a histological analysis of histotripsy lesions in porcine liver. We find that R2 and the ADC are both sensitive to ablation in all materials tested here, and the degree of response varies with tissue type. Correspondingly, under histologic analysis, the porcine liver exhibited various levels of mechanical disruption and necrotic debris that are characteristic of histotripsy. While the area of intact red blood cells and nuclei found within these lesions both decreased with increasing amounts of treatment, the area of red blood cells decreased much more rapidly than the area of intact nuclei. Additionally, the decrease in area of intact red blood cells saturated at the same treatment levels at which the response of the R2 saturated while the area of intact nuclei appeared to vary linearly with the response of the ADC.

Optical functional performance of the osteo-odonto-keratoprosthesis.

PubMed

Lee, Richard M H; Ong, Gek L; Lam, Fook Chang; White, Joy; Crook, David; Liu, Christopher S C; Hull, Chris C

2014-10-01

The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP). Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities. The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.

ROS production, intracellular HSP70 levels and their relationship in human neutrophils: effects of age.

PubMed

Kovalenko, Elena I; Boyko, Anna A; Semenkov, Victor F; Lutsenko, Gennady V; Grechikhina, Maria V; Kanevskiy, Leonid M; Azhikina, Tatyana L; Telford, William G; Sapozhnikov, Alexander M

2014-12-15

ROS production and intracellular HSP70 levels were measured in human neutrophils for three age groups: young (20-59 years), elders (60-89 years) and nonagenarians (90 years and older). Elders showed higher levels of spontaneous intracellular ROS content compared with young and nonagenarian groups, which had similar intracellular ROS levels. Zymosan-induced (non-spontaneous) extracellular ROS levels were also similar for young and nonagenarians but were lower in elders. However, spontaneous extracellular ROS production increased continuously with age. Correlation analysis revealed positive relationships between HSP70 levels and zymosan-stimulated ROS production in the elder group. This was consistent with a promoting role for HSP70 in ROS-associated neutrophils response to pathogens. No positive correlation between ROS production and intracellular HSP70 levels was found for groups of young people and nonagenarians. In contrast, significant negative correlations of some ROS and HSP70 characteriscics were found for neutrophils from young people and nonagenarians. The observed difference in ROS and HSP70 correlations in elders and nonagenarians might be associated with an increased risk of mortality in older individuals less than 90 years old.

Effects of contour enhancement on low-vision preference and visual search.

PubMed

Satgunam, Premnandhini; Woods, Russell L; Luo, Gang; Bronstad, P Matthew; Reynolds, Zachary; Ramachandra, Chaithanya; Mel, Bartlett W; Peli, Eli

2012-09-01

To determine whether image enhancement improves visual search performance and whether enhanced images were also preferred by subjects with vision impairment. Subjects (n = 24) with vision impairment (vision: 20/52 to 20/240) completed visual search and preference tasks for 150 static images that were enhanced to increase object contours' visual saliency. Subjects were divided into two groups and were shown three enhancement levels. Original and medium enhancements were shown to both groups. High enhancement was shown to group 1, and low enhancement was shown to group 2. For search, subjects pointed to an object that matched a search target displayed at the top left of the screen. An "integrated search performance" measure (area under the curve of cumulative correct response rate over search time) quantified performance. For preference, subjects indicated the preferred side when viewing the same image with different enhancement levels on side-by-side high-definition televisions. Contour enhancement did not improve performance in the visual search task. Group 1 subjects significantly (p < 0.001) rejected the High enhancement, and showed no preference for medium enhancement over the original images. Group 2 subjects significantly preferred (p < 0.001) both the medium and the low enhancement levels over original. Contrast sensitivity was correlated with both preference and performance; subjects with worse contrast sensitivity performed worse in the search task (ρ = 0.77, p < 0.001) and preferred more enhancement (ρ = -0.47, p = 0.02). No correlation between visual search performance and enhancement preference was found. However, a small group of subjects (n = 6) in a narrow range of mid-contrast sensitivity performed better with the enhancement, and most (n = 5) also preferred the enhancement. Preferences for image enhancement can be dissociated from search performance in people with vision impairment. Further investigations are needed to study the relationships between preference and performance for a narrow range of mid-contrast sensitivity where a beneficial effect of enhancement may exist.

Moderate perinatal thyroid hormone insufficiency alters visual system function in adult rats.

PubMed

Boyes, William K; Degn, Laura; George, Barbara Jane; Gilbert, Mary E

2018-04-21

Thyroid hormone (TH) is critical for many aspects of neurodevelopment and can be disrupted by a variety of environmental contaminants. Sensory systems, including audition and vision are vulnerable to TH insufficiencies, but little data are available on visual system development at less than severe levels of TH deprivation. The goal of the current experiments was to explore dose-response relations between graded levels of TH insufficiency during development and the visual function of adult offspring. Pregnant Long Evans rats received 0 or 3 ppm (Experiment 1), or 0, 1, 2, or 3 ppm (Experiment 2) of propylthiouracil (PTU), an inhibitor of thyroid hormone synthesis, in drinking water from gestation day (GD) 6 to postnatal day (PN) 21. Treatment with PTU caused dose-related reductions of serum T4, with recovery on termination of exposure, and euthyroidism by the time of visual function testing. Tests of retinal (electroretinograms; ERGs) and visual cortex (visual evoked potentials; VEPs) function were assessed in adult offspring. Dark-adapted ERG a-waves, reflecting rod photoreceptors, were increased in amplitude by PTU. Light-adapted green flicker ERGs, reflecting M-cone photoreceptors, were reduced by PTU exposure. UV-flicker ERGs, reflecting S-cones, were not altered. Pattern-elicited VEPs were significantly reduced by 2 and 3 ppm PTU across a range of stimulus contrast values. The slope of VEP amplitude-log contrast functions was reduced by PTU, suggesting impaired visual contrast gain. Visual contrast gain primarily reflects function of visual cortex, and is responsible for adjusting sensitivity of perceptual mechanisms in response to changing visual scenes. The results indicate that moderate levels of pre-and post-natal TH insufficiency led to alterations in visual function of adult rats, including both retinal and visual cortex sites of dysfunction. Copyright © 2018. Published by Elsevier B.V.

Does angiography increase the risk of impairment in renal function during non-operative management of patients with blunt splenic injuries? A cross-sectional study in southern Taiwan

PubMed Central

Hsieh, Ting-Min; Tsai, Tzu-Hsien; Lin, Chih-Che; Hsieh, Ching-Hua

2016-01-01

Objectives The aim of the present study was to assess whether angiography after contrast-enhanced CT (CECT) as per the policy of non-operative management would add to the risk of acute kidney injury in patients with blunt splenic injuries (BSIs). Design Cross-sectional study. Setting Taiwan. Participants Patients with BSI aged >16 years, admitted to a level I trauma centre during the period of January 2004 to December 2014, were retrospectively reviewed. A total of 326 patients with BSI with CECT were included in the study, of whom 100 underwent subsequent angiography and 226 did not. Main outcome measures Incidence of contrast-induced nephropathy (CIN) and renal function as measured by the 48-hour serum creatinine (SCr) levels. Results No significant difference between the patients who underwent angiography and those who did not in terms of the initial haemoglobin (Hb), SCr or estimated glomerular filtration rate (eGFR) level on arrival at the emergency department, 48 hours later, or at discharge. No significant difference in the incidence of CIN was found between these two groups of patients regardless of the criteria for identifying CIN. In the group of patients aged ≥55 years, those who underwent angiography had a significantly worse 48-hour SCr level than those who did not undergo the treatment. In addition, there was no significant difference in the 48-hour SCr level between the two groups of patients when subgrouping the patients according to sex, large haemoperitoneum revealed on CT, systolic blood pressure, initial Hb, initial SCr and initial eGFR levels. Conclusions This study demonstrated that angiography does not increase the incidence of CIN, and was not a risk factor to renal function impairment in patients with BSI who had undergone CECT. PMID:27798008

Does angiography increase the risk of impairment in renal function during non-operative management of patients with blunt splenic injuries? A cross-sectional study in southern Taiwan.

PubMed

Hsieh, Ting-Min; Tsai, Tzu-Hsien; Lin, Chih-Che; Hsieh, Ching-Hua

2016-10-21

The aim of the present study was to assess whether angiography after contrast-enhanced CT (CECT) as per the policy of non-operative management would add to the risk of acute kidney injury in patients with blunt splenic injuries (BSIs). Cross-sectional study. Taiwan. Patients with BSI aged >16 years, admitted to a level I trauma centre during the period of January 2004 to December 2014, were retrospectively reviewed. A total of 326 patients with BSI with CECT were included in the study, of whom 100 underwent subsequent angiography and 226 did not. Incidence of contrast-induced nephropathy (CIN) and renal function as measured by the 48-hour serum creatinine (SCr) levels. No significant difference between the patients who underwent angiography and those who did not in terms of the initial haemoglobin (Hb), SCr or estimated glomerular filtration rate (eGFR) level on arrival at the emergency department, 48 hours later, or at discharge. No significant difference in the incidence of CIN was found between these two groups of patients regardless of the criteria for identifying CIN. In the group of patients aged ≥55 years, those who underwent angiography had a significantly worse 48-hour SCr level than those who did not undergo the treatment. In addition, there was no significant difference in the 48-hour SCr level between the two groups of patients when subgrouping the patients according to sex, large haemoperitoneum revealed on CT, systolic blood pressure, initial Hb, initial SCr and initial eGFR levels. This study demonstrated that angiography does not increase the incidence of CIN, and was not a risk factor to renal function impairment in patients with BSI who had undergone CECT. 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/.

Uridine Affects Liver Protein Glycosylation, Insulin Signaling, and Heme Biosynthesis

PubMed Central

Urasaki, Yasuyo; Pizzorno, Giuseppe; Le, Thuc T.

2014-01-01

Purines and pyrimidines are complementary bases of the genetic code. The roles of purines and their derivatives in cellular signal transduction and energy metabolism are well-known. In contrast, the roles of pyrimidines and their derivatives in cellular function remain poorly understood. In this study, the roles of uridine, a pyrimidine nucleoside, in liver metabolism are examined in mice. We report that short-term uridine administration in C57BL/6J mice increases liver protein glycosylation profiles, reduces phosphorylation level of insulin signaling proteins, and activates the HRI-eIF-2α-ATF4 heme-deficiency stress response pathway. Short-term uridine administration is also associated with reduced liver hemin level and reduced ability for insulin-stimulated blood glucose removal during an insulin tolerance test. Some of the short-term effects of exogenous uridine in C57BL/6J mice are conserved in transgenic UPase1 −/− mice with long-term elevation of endogenous uridine level. UPase1 −/− mice exhibit activation of the liver HRI-eIF-2α-ATF4 heme-deficiency stress response pathway. UPase1 −/− mice also exhibit impaired ability for insulin-stimulated blood glucose removal. However, other short-term effects of exogenous uridine in C57BL/6J mice are not conserved in UPase1 −/− mice. UPase1 −/− mice exhibit normal phosphorylation level of liver insulin signaling proteins and increased liver hemin concentration compared to untreated control C57BL/6J mice. Contrasting short-term and long-term consequences of uridine on liver metabolism suggest that uridine exerts transient effects and elicits adaptive responses. Taken together, our data support potential roles of pyrimidines and their derivatives in the regulation of liver metabolism. PMID:24918436

Gender and Gonadal Status Differences in Zona Reticularis Expression in Marmoset Monkey Adrenals: Cytochrome b5 Localization With Respect To Cytochrome P450 17,20-Lyase Activity.

PubMed Central

Pattison, J Christina; Saltzman, Wendy; Abbott, David H; Hogan, Brynn K; Nguyen, Ann D; Husen, Bettina; Einspanier, Almuth; Conley, Alan J; Bird., Ian M

2007-01-01

Neonatal marmosets express an adrenal fetal zone comparable to humans. While adult males fail to express a functional ZR, with barely detectable blood DHEA levels, females produce higher levels of DHEA than males in adulthood. We investigated the presence of a putative functional ZR in adult female marmosets. In contrast to males, immunohistochemical analysis showed the ZR marker cytochrome b5 was elevated in the innermost zone in cycling females (compared to testis-intact males), further elevated in the adrenals from anovulatory females, and substantially elevated and continuous in ovariectomized females. As a functional test in vivo, following overnight dexamethasone treatment, cycling and anovulatory females showed higher levels of DHEA relative to males, but DHEA failed to increase in response to ACTH. In direct contrast, while ovariectomized females exhibited lower initial DHEA levels, clear increases were detectable after ACTH administration (p<0.05), suggesting an adrenal origin. The apparent differences in cytochrome b5 expression between groups were also further verified by western blotting of adrenal microsomes, and compared to 17,20-lyase activity; the two parameters were positively correlated (p<0.01) across multiple treatment groups. We conclude that the cycling female marmoset expresses a rudimentary ZR with at least a capacity for DHEA production that becomes significantly ACTH-responsive after anovulation. Expression of cytochrome b5 in this region may be directly or indirectly controlled by gonadal function, and is, at least in part, a critical determinant in the development of an adrenal ZR that is more defined and significantly ACTH-responsive. PMID:17222503

How Does Exposure to Cigarette Advertising Contribute to Smoking in Adolescents? The Role of the Developing Self-Concept and Identification with Advertising Models

PubMed Central

Shadel, William G.; Tharp-Taylor, Shannah; Fryer, Craig S.

2009-01-01

Increased exposure to cigarette advertisements is associated with increases in adolescent smoking but the reasons for this association are not well established. This study evaluated whether self-concept development (operationalized as level of self-conflict) and identifying with the models used in cigarette print advertising contributed to smoking intentions among adolescents. Ninety-five adolescents (ages 11-17) participated in this two session study. In session 1, they rated the extent to which they identified with the models used in 10 current cigarette print ads (the models were isolated digitally from the cigarette advertisements) and their level of self-conflict was assessed. In session 2, participants viewed each of the 10 cigarette advertisements from which the models were drawn and rated their intentions to smoke following exposure to each ad. Model identification was associated with similar levels of post ad exposure smoking intentions for both younger and older adolescents when they also exhibited no self-conflict. A contrasting set of findings emerged for younger and older adolescents when they exhibited high levels of self-conflict: Young adolescents who strongly identified with the models used in cigarette advertisements had higher post ad exposure smoking intentions compared to younger adolescents who weakly identified with the models used in the advertisements; in contrast, older adolescents who weakly identified with the models used in cigarette advertisements had stronger post ad exposure smoking intentions compared to older adolescents who strongly identified with the models used in the advertisements. These results point to the importance of examining developmentally-relevant moderators for the effects of cigarette advertising exposure. PMID:19505768

How does exposure to cigarette advertising contribute to smoking in adolescents? The role of the developing self-concept and identification with advertising models.

PubMed

Shadel, William G; Tharp-Taylor, Shannah; Fryer, Craig S

2009-11-01

Increased exposure to cigarette advertisements is associated with increases in adolescent smoking but the reasons for this association are not well established. This study evaluated whether self-concept development (operationalized as level of self-conflict) and identifying with the models used in cigarette print advertising contributed to smoking intentions among adolescents. Ninety-five adolescents (ages 11-17) participated in this two session study. In session 1, they rated the extent to which they identified with the models used in 10 current cigarette print ads (the models were isolated digitally from the cigarette advertisements) and their level of self-conflict was assessed. In session 2, participants viewed each of the 10 cigarette advertisements from which the models were drawn and rated their intentions to smoke following exposure to each ad. Model identification was associated with similar levels of post ad exposure smoking intentions for both younger and older adolescents when they also exhibited no self-conflict. A contrasting set of findings emerged for younger and older adolescents when they exhibited high levels of self-conflict: Young adolescents who strongly identified with the models used in cigarette advertisements had higher post ad exposure smoking intentions compared to younger adolescents who weakly identified with the models used in the advertisements; in contrast, older adolescents who weakly identified with the models used in cigarette advertisements had stronger post ad exposure smoking intentions compared to older adolescents who strongly identified with the models used in the advertisements. These results point to the importance of examining developmentally-relevant moderators for the effects of cigarette advertising exposure.

In Search of the Optimal Heart Perfusion Ultrasound Imaging Platform.

PubMed

Grishenkov, Dmitry; Gonon, Adrian; Janerot-Sjoberg, Birgitta

2015-09-01

Quantification of myocardial perfusion by contrast echocardiography remains a challenge. Existing imaging phantoms used to evaluate the performance of ultrasound scanners do not comply with perfusion basics in the myocardium, where perfusion and motion are inherently coupled. To contribute toward an improvement, we developed a contrast echocardiographic perfusion imaging platform based on an isolated rat heart coupled to an ultrasound scanner. Perfusion was assessed by using 3 different types of contrast agents: dextran-based Promiten (Meda AB, Solna, Sweden), phospholipid-shelled SonoVue (Bracco Diagnostics, Inc, Princeton, NJ), and polymer-shelled MB-pH5-RT, developed in-house. The myocardial video intensity was monitored over time from contrast agent administration to peak, and 2 characteristic constants were calculated by using an exponential fit: A, representing capillary volume; and β, representing inflow velocity. Acquired experimental evidence demonstrates that the application of all 3 contrast agents allows sonographic estimation of myocardial perfusion in the isolated rat heart. Video intensity maps show that an increase in contrast concentration increases the late-plateau values, A, mimicking increased capillary volume. Estimated values of the flow, proportional to A × β, increase when the pressure of the perfusate column increases from 80 to 110 cm of water. This finding is in agreement with the true values of the coronary flow increase measured by a flowmeter attached to the aortic cannula. The contrast echocardiographic perfusion imaging platform described holds promise for standardized evaluation and optimization of contrast perfusion ultrasound imaging in which real-time inflow curves at low acoustic power semiquantitatively reflect coronary flow. © 2015 by the American Institute of Ultrasound in Medicine.

Groundwater level changes in a deep well in response to a magma intrusion event on Kilauea Volcano, Hawai'i

USGS Publications Warehouse

Hurwitz, S.; Johnston, M.J.S.

2003-01-01

On May 21, 2001, an abrupt inflation of Kilauea Volcano's summit induced a rapid and large increase in compressional strain, with a maximum of 2 ??strain recorded by a borehole dilatometer. Water level (pressure) simultaneously dropped by 6 cm. This mode of water level change (drop) is in contrast to that expected for compressional strain from poroelastic theory, and therefore it is proposed that the stress applied by the intrusion has caused opening of fractures or interflows that drained water out of the well. Upon relaxation of the stress recorded by the dilatometer, water levels have recovered at a similar rate. The proposed model has implications for the analysis of ground surface deformation and for mechanisms that trigger phreatomagmatic eruptions.

Nationwide forestry applications program: Ten-Ecosystem Study (TES) site 5 report, Kershaw County, South Carolina, report 4

NASA Technical Reports Server (NTRS)

Dillman, R. D. (Principal Investigator)

1978-01-01

The author has identified the following significant results. The Kershaw County site, South Carolina, was selected to be representative of both the oak-pine ecosystem and the southeastern pine ecosystem. The following processing results have concluded that: (1) early spring LANDSAT data provide the best contrast between forest features; (2) level 2 forest features (softwood, hardwood, grassland, and water) can be classified with an accuracy of 70% + or - 5.7% at the 90% confidence level; (3) level 3 species classification was inconclusive; (4) temporal data did not provide a significant increase in classification accuracy of level 2 features, over single date classification to warrant the additional processing; and (5) training fields from only 10% of the site can be used to classify the entire site.

Contrasting Academic Behavioural Confidence in Mexican and European Psychology Students

ERIC Educational Resources Information Center

Ochoa, Alma Rosa Aguila; Sander, Paul

2012-01-01

Introduction: Research with the Academic Behavioural Confidence scale using European students has shown that students have high levels of confidence in their academic abilities. It is generally accepted that people in more collectivist cultures have more realistic confidence levels in contrast to the overconfidence seen in individualistic European…

The Quantized Geometry of Visual Space: The Coherent Computation of Depth, Form, and Lightness. Revised Version.

DTIC Science & Technology

1982-08-01

of sensitivity with background luminance, and the finitE capacity of visual short term memory are discussed in terms of a small set of ...binocular rivalry, reflectance rivalry, Fechner’s paradox, decrease of threshold contrast with increased number of cycles in a grating pattern, hysteresis...adaptation level tuning, Weber law modulation, shift of sensitivity with background luminance, and the finite capacity of visual

Regulation of CD4+ T-Cell Function by Membrane Cholesterol

DTIC Science & Technology

2012-03-13

hypercholesterolemia in mice was associated with an increased number of 97 splenic CD4 T-cells [65]. In contrast, Atorvastatin -induced inhibition of HMG...Mauri C, Ehrenstein MR (2006) Atorvastatin restores Lck expression and lipid raft-associated signaling in T cells from patients with systemic lupus...J, Rehm C, et al. (2011) High dose atorvastatin decreases cellular markers of immune activation without affecting HIV-1 RNA levels: results of a

Genotoxic effect of ethacrynic acid and impact of antioxidants

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

Ward, William M.; Hoffman, Jared D.; Loo, George, E-mail: g_loo@uncg.edu

It is known that ethacrynic acid (EA) decreases the intracellular levels of glutathione. Whether the anticipated oxidative stress affects the structural integrity of DNA is unknown. Therefore, DNA damage was assessed in EA-treated HCT116 cells, and the impact of several antioxidants was also determined. EA caused both concentration-dependent and time-dependent DNA damage that eventually resulted in cell death. Unexpectedly, the DNA damage caused by EA was intensified by either ascorbic acid or trolox. In contrast, EA-induced DNA damage was reduced by N-acetylcysteine and by the iron chelator, deferoxamine. In elucidating the DNA damage, it was determined that EA increased themore » production of reactive oxygen species, which was inhibited by N-acetylcysteine and deferoxamine but not by ascorbic acid and trolox. Also, EA decreased glutathione levels, which were inhibited by N-acetylcysteine. But, ascorbic acid, trolox, and deferoxamine neither inhibited nor enhanced the capacity of EA to decrease glutathione. Interestingly, the glutathione synthesis inhibitor, buthionine sulfoxime, lowered glutathione to a similar degree as EA, but no noticeable DNA damage was found. Nevertheless, buthionine sulfoxime potentiated the glutathione-lowering effect of EA and intensified the DNA damage caused by EA. Additionally, in examining redox-sensitive stress gene expression, it was found that EA increased HO-1, GADD153, and p21mRNA expression, in association with increased nuclear localization of Nrf-2 and p53 proteins. In contrast to ascorbic acid, trolox, and deferoxamine, N-acetylcysteine suppressed the EA-induced upregulation of GADD153, although not of HO-1. Overall, it is concluded that EA has genotoxic properties that can be amplified by certain antioxidants. - Highlights: • Ethacrynic acid (EA) caused cellular DNA damage. • EA-induced DNA damage was potentiated by ascorbic acid or trolox. • EA increased ROS production, not inhibited by ascorbic acid or trolox. • EA decreased glutathione levels, not prevented by ascorbic acid or trolox. • Buthionine sulfoxime intensified the DNA damage caused by EA.« less

Evaluation of contrast-enhanced power Doppler imaging for measuring blood flow

NASA Astrophysics Data System (ADS)

Ansaloni, Sara; Arger, Peter H.; Cary, Ted W.; Sehgal, Chandra M.

2005-04-01

Power Doppler ultrasound enhanced by microbubble contrast agent has been used to image tissue vascularity and blood flow for the assessment of antivascular therapies. We have proposed a multigating technique that measures bubble concentration as a function of ultrasound exposure for deriving tumor blood flow and vascularity.1 Techniques using ultrasound contrast agent are known to be sensitive to the choice of imaging parameters like mechanical index and tissue attenuation. In this paper, the roles of mechanical index (MI) and tissue attenuation were evaluated experimentally in a rubber tubing flow phantom connected to a mixing chamber and a variable speed pump. The contrast was injected in the mixing chamber and the flow rate was measured using power Doppler imaging. The measurements were repeated at different MIs (0.1 to 1.3), and at different levels of attenuation, obtained with solutions of glycerol-water (10-20%). True flow was measured by collecting liquid flowing out of the phantom over a fixed duration. At low MI (<0.5), the grayscale and Doppler signal were weak, making these images unsuitable for analysis. At higher MI (> 0.8), there was a well-defined enhancement by contrast agent resulting in reproducible flow measurements at variable MIs. A balance between the number of bubbles destroyed and the echo they generate must be achieved for optimal imaging. The increased attenuation of ultrasound by the overlying medium did not influence the flow measurements.

Comparative Analysis of Metallic Nanoparticles as Exogenous Soft Tissue Contrast for Live In Vivo Micro-Computed Tomography Imaging of Avian Embryonic Morphogenesis

PubMed Central

Gregg, Chelsea L.; Butcher, Jonathan T.

2016-01-01

Background Gestationally survivable congenital malformations arise during mid-late stages of development that are inaccessible in vivo with traditional optical imaging for assessing long term abnormal patterning. MicroCT is an attractive technology to rapidly and inexpensively generate quantitative 3D datasets but requires exogenous contrast media. Here we establish dose dependent toxicity, persistence, and biodistribution of three different metallic nanoparticles in day 4 chick embryos. Results We determined that 110nm alkaline earth metal particles were non-toxic and persisted in the chick embryo for up to 24 hours post injection with contrast enhancement levels at high as 1600HU. 15nm gold nanoparticles persisted with x-ray attenuation higher than that of the surrounding yolk and albumen for up to 8 hours post injection, while 1.9nm particles resulted in lethality by 8 hours. We identified spatial and temporally heterogeneous contrast enhancement ranging from 250-1600HU. With the most optimal 110nm alkaline earth metal particles, we quantified an exponential increase in the tissue perfusion versus distance from the dorsal aorta into the flank over 8 hours with a peak perfusion rate of 0.7um2/s measured at a distance of 0.3mm. Conclusion These results demonstrate the safety, efficacy, and opportunity of nanoparticle based contrast media in live embryos for quantitative analysis of embryogenesis. PMID:27447729

Fuzzy entropy thresholding and multi-scale morphological approach for microscopic image enhancement

NASA Astrophysics Data System (ADS)

Zhou, Jiancan; Li, Yuexiang; Shen, Linlin

2017-07-01

Microscopic images provide lots of useful information for modern diagnosis and biological research. However, due to the unstable lighting condition during image capturing, two main problems, i.e., high-level noises and low image contrast, occurred in the generated cell images. In this paper, a simple but efficient enhancement framework is proposed to address the problems. The framework removes image noises using a hybrid method based on wavelet transform and fuzzy-entropy, and enhances the image contrast with an adaptive morphological approach. Experiments on real cell dataset were made to assess the performance of proposed framework. The experimental results demonstrate that our proposed enhancement framework increases the cell tracking accuracy to an average of 74.49%, which outperforms the benchmark algorithm, i.e., 46.18%.

Multimodel Assessment of the Factors Driving Stratospheric Ozone Evolution over the 21st Century

NASA Technical Reports Server (NTRS)

Oman, L. D.; Plummer, D. A.; Waugh, D. W.; Austin, J.; Scinocca, J. F.; Douglass, A. R.; Salawitch, R. J.; Canty, T.; Akiyoshi, H.; Bekki, S.;

Association of outdoor recreation availability with physical activity and weight status in Minnesota youth.

PubMed

Wilhelm Stanis, Sonja A; Oftedal, Andrew; Schneider, Ingrid

2014-03-01

Examine macro-level associations of youth physical activity (PA) and weight status with availability of outdoor recreation resources (i.e., parkland, forestland, natural preserves, nonmotorized trails, and motorized trails) across counties in Minnesota. Hierarchical regression models examined if availability of recreation resources significantly improved prediction of PA and weight status of 9th and 12th grade boys and girls (2010) across Minnesota counties. The inclusion of county-level densities of recreational land variables did not produce a significant increase in R(2) for any of the models predicting 9th grade outcomes, yet county-level densities of recreational trails did significantly increase R(2) for both levels of PA and weight status. In contrast, the inclusion of recreational trails did not produce any significant increases in R(2) for 12th grade outcomes, although the inclusion of recreational land did significantly increase the R(2) for 12th grade girls achieving 30min of PA 5 or more days of the week. Findings indicate that various recreational land and trail types may have different impacts on and associations with PA and health outcomes. As such, it is important that future studies focus not only on parks, but also on other types of recreational lands and trails as well. Copyright © 2013 Elsevier Inc. All rights reserved.

γδ T cells affect IL-4 production and B-cell tolerance

PubMed Central

Huang, Yafei; Heiser, Ryan A.; Detanico, Thiago O.; Getahun, Andrew; Kirchenbaum, Greg A.; Casper, Tamara L.; Aydintug, M. Kemal; Carding, Simon R.; Ikuta, Koichi; Huang, Hua; Cambier, John C.; Wysocki, Lawrence J.; O’Brien, Rebecca L.; Born, Willi K.

2015-01-01

γδ T cells can influence specific antibody responses. Here, we report that mice deficient in individual γδ T-cell subsets have altered levels of serum antibodies, including all major subclasses, sometimes regardless of the presence of αβ T cells. One strain with a partial γδ deficiency that increases IgE antibodies also displayed increases in IL-4–producing T cells (both residual γδ T cells and αβ T cells) and in systemic IL-4 levels. Its B cells expressed IL-4–regulated inhibitory receptors (CD5, CD22, and CD32) at diminished levels, whereas IL-4–inducible IL-4 receptor α and MHCII were increased. They also showed signs of activation and spontaneously formed germinal centers. These mice displayed IgE-dependent features found in hyper-IgE syndrome and developed antichromatin, antinuclear, and anticytoplasmic autoantibodies. In contrast, mice deficient in all γδ T cells had nearly unchanged Ig levels and did not develop autoantibodies. Removing IL-4 abrogated the increases in IgE, antichromatin antibodies, and autoantibodies in the partially γδ-deficient mice. Our data suggest that γδ T cells, controlled by their own cross-talk, affect IL-4 production, B-cell activation, and B-cell tolerance. PMID:25535377

γδ T cells affect IL-4 production and B-cell tolerance.

PubMed

Huang, Yafei; Heiser, Ryan A; Detanico, Thiago O; Getahun, Andrew; Kirchenbaum, Greg A; Casper, Tamara L; Aydintug, M Kemal; Carding, Simon R; Ikuta, Koichi; Huang, Hua; Cambier, John C; Wysocki, Lawrence J; O'Brien, Rebecca L; Born, Willi K

2015-01-06

γδ T cells can influence specific antibody responses. Here, we report that mice deficient in individual γδ T-cell subsets have altered levels of serum antibodies, including all major subclasses, sometimes regardless of the presence of αβ T cells. One strain with a partial γδ deficiency that increases IgE antibodies also displayed increases in IL-4-producing T cells (both residual γδ T cells and αβ T cells) and in systemic IL-4 levels. Its B cells expressed IL-4-regulated inhibitory receptors (CD5, CD22, and CD32) at diminished levels, whereas IL-4-inducible IL-4 receptor α and MHCII were increased. They also showed signs of activation and spontaneously formed germinal centers. These mice displayed IgE-dependent features found in hyper-IgE syndrome and developed antichromatin, antinuclear, and anticytoplasmic autoantibodies. In contrast, mice deficient in all γδ T cells had nearly unchanged Ig levels and did not develop autoantibodies. Removing IL-4 abrogated the increases in IgE, antichromatin antibodies, and autoantibodies in the partially γδ-deficient mice. Our data suggest that γδ T cells, controlled by their own cross-talk, affect IL-4 production, B-cell activation, and B-cell tolerance.

Allo-parental care in Damaraland mole-rats is female biased and age dependent, though independent of testosterone levels.

PubMed

Zöttl, Markus; Vullioud, Philippe; Goddard, Katy; Torrents-Ticó, Miquel; Gaynor, David; Bennett, Nigel C; Clutton-Brock, Tim

2018-05-02

In Damaraland mole-rats (Fukomys damarensis), non-breeding subordinates contribute to the care of offspring born to the breeding pair in their group by carrying and retrieving young to the nest. In social mole-rats and some cooperative breeders, dominant females show unusually high testosterone levels and it has been suggested that high testosterone levels may increase reproductive and aggressive behavior and reduce investment in allo-parental and parental care, generating age and state-dependent variation in behavior. Here we show that, in Damaraland mole-rats, allo-parental care in males and females is unaffected by experimental increases in testosterone levels. Pup carrying decreases with age of the non-breeding helper while the change in social status from non-breeder to breeder has contrasting effects in the two sexes. Female breeders were more likely than female non-breeders to carry pups but male breeders were less likely to carry pups than male non-breeders, increasing the sex bias in parental care compared to allo-parental care. Our results indicate that testosterone is unlikely to be an important regulator of allo-parental care in mole-rats. Copyright © 2018. Published by Elsevier Inc.

Does increasing rotation length lead to greater forest carbon storage?

NASA Astrophysics Data System (ADS)

Ter-Mikaelian, M. T.; Colombo, S. J.; Chen, J.

2016-12-01

Forest management is a key factor affecting climate change mitigation by forests. Increasing the age of harvesting (also referred to as rotation length) is a management practice that has been proposed as a means of increasing forest carbon sequestration and storage. However, studies of the effects of increasing harvest age on forest carbon stocks have mostly been limited to forest plantations. In contrast, this study assesses the effects of increased harvest age of managed natural forests of Ontario (Canada) at two scales. At the stand level, we assess merchantable volume yield curves to differentiate those for which increasing the age of harvest results in an increase in total forest carbon stocks versus those for which increased harvest age reduces carbon stocks. The stand level results are then applied to forest landscapes to demonstrate that the effect of increasing the age of harvest on forest carbon storage is specific to the forest growth rates for a given forest landscape and depends on the average age at which forests are harvested under current (business-as-usual) management practice. We discuss the implications of these results for forest management aimed at mitigating climate change.

Juvenile Hormone Biosynthesis Gene Expression in the corpora allata of Honey Bee (Apis mellifera L.) Female Castes

PubMed Central

Rosa, Gustavo Conrado Couto; Moda, Livia Maria; Martins, Juliana Ramos; Bitondi, Márcia Maria Gentile; Hartfelder, Klaus; Simões, Zilá Luz Paulino

2014-01-01

Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution. PMID:24489805

The Influence of Flightless I on Toll-Like-Receptor-Mediated Inflammation in a Murine Model of Diabetic Wound Healing

PubMed Central

Ruzehaji, Nadira; Mills, Stuart J.; Melville, Elizabeth; Arkell, Ruth; Fitridge, Robert; Cowin, Allison J.

2013-01-01

Impaired wound healing and ulceration represent a serious complication of both type 1 and type 2 diabetes. Cytoskeletal protein Flightless I (Flii) is an important inhibitor of wound repair, and reduced Flii gene expression in fibroblasts increased migration, proliferation, and adhesion. As such it has the ability to influence all phases of wound healing including inflammation, remodelling and angiogenesis. Flii has the potential to modulate inflammation through its interaction with MyD88 which it an adaptor protein for TLR4. To assess the effect of Flii on the inflammatory response of diabetic wounds, we used a murine model of streptozocin-induced diabetes and Flii genetic mice. Increased levels of Flii were detected in Flii transgenic murine wounds resulting in impaired healing which was exacerbated when diabetes was induced. When Flii levels were reduced in diabetic wounds of Flii-deficient mice, healing was improved and decreased levels of TLR4 were observed. In contrast, increasing the level of Flii in diabetic mouse wounds led to increased TLR4 and NF-κB production. Treatment of murine diabetic wounds with neutralising antibodies to Flii led to an improvement in healing with decreased expression of TLR4. Decreasing the level of Flii in diabetic wounds may therefore reduce the inflammatory response and improve healing. PMID:23555084

Lung autophagic response following exposure of mice to whole body irradiation, with and without amifostine

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

Zois, Christos E.; Giatromanolaki, Alexandra; Kainulainen, Heikki

2011-01-07

Research highlights: {yields} We investigated the effect 6 Gy of WBI on the autophagic machinery of normal mouse lung. {yields} Irradiation induces dysfunction of the autophagic machinery in normal lung, characterized by decreased transcription of the LC3A/Beclin-1 mRNA and accumulation of the LC3A, and p62 proteins. {yields} The membrane bound LC3A-II protein levels increased in the cytosolic fraction (not in the pellet), contrasting the patterns noted after starvation-induced autophagy. {yields} Administration of amifostine, reversed all the LC3A and p62 findings, suggesting protection of the normal autophagic function. -- Abstract: Purpose: The effect of ionizing irradiation on the autophagic response ofmore » normal tissues is largely unexplored. Abnormal autophagic function may interfere the protein quality control leading to cell degeneration and dysfunction. This study investigates its effect on the autophagic machinery of normal mouse lung. Methods and materials: Mice were exposed to 6 Gy of whole body {gamma}-radiation and sacrificed at various time points. The expression of MAP1LC3A/LC3A/Atg8, beclin-1, p62/sequestosome-1 and of the Bnip3 proteins was analyzed. Results: Following irradiation, the LC3A-I and LC3A-II protein levels increased significantly at 72 h and 7 days. Strikingly, LC3A-II protein was increased (5.6-fold at 7 days; p < 0.001) only in the cytosolic fraction, but remained unchanged in the membrane fraction. The p62 protein, was significantly increased in both supernatant and pellet fraction (p < 0.001), suggesting an autophagosome turnover deregulation. These findings contrast the patterns of starvation-induced autophagy up-regulation. Beclin-1 levels remained unchanged. The Bnip3 protein was significantly increased at 8 h, but it sharply decreased at 72 h (p < 0.05). Administration of amifostine (200 mg/kg), 30 min before irradiation, reversed all the LC3A and p62 findings on blots, suggesting restoration of the normal autophagic function. The LC3A and Beclin1 mRNA levels significantly declined following irradiation (p < 0.01), whereas Bnip3 levels increased. Conclusions: It is suggested that irradiation induces dysfunction of the autophagic machinery in normal lung, characterized by decreased transcription of the LC3A/Beclin-1 mRNA and accumulation of the LC3A, and p62 proteins. Whether this is due to defective maturation or to aberrant degradation of the autophagosomes requires further investigation.« less

Refining Stimulus Parameters in Assessing Infant Speech Perception Using Visual Reinforcement Infant Speech Discrimination: Sensation Level.

PubMed

Uhler, Kristin M; Baca, Rosalinda; Dudas, Emily; Fredrickson, Tammy

2015-01-01

Speech perception measures have long been considered an integral piece of the audiological assessment battery. Currently, a prelinguistic, standardized measure of speech perception is missing in the clinical assessment battery for infants and young toddlers. Such a measure would allow systematic assessment of speech perception abilities of infants as well as the potential to investigate the impact early identification of hearing loss and early fitting of amplification have on the auditory pathways. To investigate the impact of sensation level (SL) on the ability of infants with normal hearing (NH) to discriminate /a-i/ and /ba-da/ and to determine if performance on the two contrasts are significantly different in predicting the discrimination criterion. The design was based on a survival analysis model for event occurrence and a repeated measures logistic model for binary outcomes. The outcome for survival analysis was the minimum SL for criterion and the outcome for the logistic regression model was the presence/absence of achieving the criterion. Criterion achievement was designated when an infant's proportion correct score was >0.75 on the discrimination performance task. Twenty-two infants with NH sensitivity participated in this study. There were 9 males and 13 females, aged 6-14 mo. Testing took place over two to three sessions. The first session consisted of a hearing test, threshold assessment of the two speech sounds (/a/ and /i/), and if time and attention allowed, visual reinforcement infant speech discrimination (VRISD). The second session consisted of VRISD assessment for the two test contrasts (/a-i/ and /ba-da/). The presentation level started at 50 dBA. If the infant was unable to successfully achieve criterion (>0.75) at 50 dBA, the presentation level was increased to 70 dBA followed by 60 dBA. Data examination included an event analysis, which provided the probability of criterion distribution across SL. The second stage of the analysis was a repeated measures logistic regression where SL and contrast were used to predict the likelihood of speech discrimination criterion. Infants were able to reach criterion for the /a-i/ contrast at statistically lower SLs when compared to /ba-da/. There were six infants who never reached criterion for /ba-da/ and one never reached criterion for /a-i/. The conditional probability of not reaching criterion by 70 dB SL was 0% for /a-i/ and 21% for /ba-da/. The predictive logistic regression model showed that children were more likely to discriminate the /a-i/ even when controlling for SL. Nearly all normal-hearing infants can demonstrate discrimination criterion of a vowel contrast at 60 dB SL, while a level of ≥70 dB SL may be needed to allow all infants to demonstrate discrimination criterion of a difficult consonant contrast. American Academy of Audiology.

Regulation of bone sialoprotein mRNA by steroid hormones

PubMed Central

1989-01-01

In this report we demonstrate an increase in the steady-state level of bone sialoprotein (BSP) mRNA in rat calvaria and a rat osteosarcoma cell line (ROS 17/2.8) after treatment with the synthetic glucocorticoid, dexamethasone. In contrast, 1.25-dihydroxyvitamin D3 reduced the amount of BSP mRNA in calvaria and inhibited the dexamethasone induction in ROS 17/2.8 cells. The increase in BSP mRNA is most likely due to an increase in the transcriptional rate. The stability of mRNA was unchanged after dexamethasone treatment with a half-life of approximately 5 h. Nuclear transcription experiments with nuclei isolated from ROS 17/2.8 cells showed an increased BSP mRNA synthesis in cells treated with dexamethasone. PMID:2592421

T-cell receptor excision circles (TREC) in CD4+ and CD8+ T-cell subpopulations in atopic dermatitis and psoriasis show major differences in the emission of recent thymic emigrants.

PubMed

Just, Helle L; Deleuran, Mette; Vestergaard, Christian; Deleuran, Bent; Thestrup-Pedersen, Kristian

2008-01-01

We used T-cell receptor excision circles (TREC) to evaluate thymic function in adult patients with atopic dermatitis and psoriasis. We observed that men, but not women, with atopic dermatitis had a significantly faster decline in TREC content with increasing age compared with healthy men. In contrast, both men and women with psoriasis had significantly reduced TREC levels, which were, on average, only 30% of that of healthy persons. In atopic dermatitis the levels of TREC declined with increasing levels of IgE, disease intensity and extent of eczema. Furthermore, patients with atopic dermatitis showed signs of altered thymus function, as they had a significantly greater variation in TREC content measured over time than healthy controls, especially within the CD8+ T-cell subpopulation. Because both atopic dermatitis and psoriasis patients have an increased number of T-cells, this indicates that atopic dermatitis patients can have compensatory emissions of thymic emigrants, whereas psoriatic patients do not, thus supporting different thymic function in these two diseases.

The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

NASA Astrophysics Data System (ADS)

Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

2011-06-01

The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

Insulin-Like Growth Factor Binding Proteins Increase Intracellular Calcium Levels in Two Different Cell Lines

PubMed Central

Seurin, Danielle; Lombet, Alain; Babajko, Sylvie; Godeau, François; Ricort, Jean-Marc

2013-01-01

Background Insulin-like growth factor binding proteins (IGFBPs) are six related secreted proteins that share IGF-dependent and -independent functions. If the former functions begin to be well described, the latter are somewhat more difficult to investigate and to characterize. At the cellular level, IGFBPs were shown to modulate numerous processes including cell growth, differentiation and apoptosis. However, the molecular mechanisms implicated remain largely unknown. We previously demonstrated that IGFBP-3, but not IGFBP-1 or IGFBP-5, increase intracellular calcium concentration in MCF-7 cells (Ricort J-M et al. (2002) FEBS lett 527: 293–297). Methodology/Principal Findings We perform a global analysis in which we studied, by two different approaches, the binding of each IGFBP isoform (i.e., IGFBP-1 to -6) to the surface of two different cellular models, MCF-7 breast adenocarcinoma cells and C2 myoblast proliferative cells, as well as the IGFBP-induced increase of intracellular calcium concentration. Using both confocal fluorescence microscopy and flow cytometry analysis, we showed that all IGFBPs bind to MCF-7 cell surface. By contrast, only four IGFBPs can bind to C2 cell surface since neither IGFBP-2 nor IGFBP-4 were detected. Among the six IGFBPs tested, only IGFBP-1 did not increased intracellular calcium concentration whatever the cellular model studied. By contrast, IGFBP-2, -3, -4 and -6, in MCF-7 cells, and IGFBP-3, -5 and -6, in C2 proliferative cells, induce a rapid and transient increase in intracellular free calcium concentration. Moreover, IGFBP-2 and -3 (in MCF-7 cells) and IGFBP-5 (in C2 cells) increase intracellular free calcium concentration by a pertussis toxin sensitive signaling pathway. Conclusions Our results demonstrate that IGFBPs are able to bind to cell surface and increase intracellular calcium concentration. By characterizing the IGFBPs-induced cell responses and intracellular couplings, we highlight the cellular specificity and complexity of the IGF-independent actions of these IGF binding proteins. PMID:23527161

Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging

NASA Astrophysics Data System (ADS)

Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L.; Leung, Ben Y. C.; Goertz, David E.; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F.; Kim, Chulhong

2014-01-01

Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging.

PubMed

Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L; Leung, Ben Y C; Goertz, David E; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F; Kim, Chulhong

2014-01-01

Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

Spatially Pooled Contrast Responses Predict Neural and Perceptual Similarity of Naturalistic Image Categories

PubMed Central

Groen, Iris I. A.; Ghebreab, Sennay; Lamme, Victor A. F.; Scholte, H. Steven

2012-01-01

The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs) in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis). Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task. PMID:23093921

What is the underestimation of radiation dose to the pediatric thyroid gland from contrast enhanced CT, if contrast medium uptake is not taken into account?

PubMed

Perisinakis, Kostas; Pouli, Styliani; Tzedakis, Antonis; Spanakis, Kostas; Hatzidakis, Adam; Raissaki, Maria; Damilakis, John

2018-05-01

To assess the underestimation of radiation dose to the thyroid of children undergoing contrast enhanced CT if contrast medium uptake is not taken into account. 161 pediatric head, head & neck and chest CT examinations were retrospectively studied to identify those involving pre- and post-contrast imaging and thyroid inclusion in imaged volume. CT density of thyroid tissue in HU was measured in non-enhanced (NECT) and corresponding contrast-enhanced CT (CECT) images. Resulting CT number increase (ΔHU) was recorded for each patient and corresponded to a % w/w iodine concentration. The relation of %w/w iodine concentration to %dose increase induced by iodinated contrast uptake was derived by Monte Carlo simulation experiments. The thyroid gland was visible in 11 chest and 3 neck CT examinations involving both pre- and post-contrast imaging. The %w/w concentration of iodine in the thyroid tissue at the time of CECT acquisition was found to be 0.13%-0.58% w/w (mean = 0.26%). The %increase of dose to thyroid tissue was found to be linearly correlated to%w/w iodine uptake. The increase in radiation dose to thyroid due to contrast uptake ranged from 12% to 44%, with a mean value of 23%. The radiation dose to the pediatric thyroid from CECT exposure may be underestimated by up to 44% if contrast medium uptake is not taken into account. Meticulous demarcation of imaged volume in pediatric chest CT examinations is imperative to avoid unnecessary direct exposure of thyroid, especially in CT examinations following intravenous administration of contrast medium. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

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

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

Protein Markers of Neurotransmitter Synthesis and Release in Postmortem Schizophrenia Substantia Nigra.

PubMed

Schoonover, Kirsten E; McCollum, Lesley A; Roberts, Rosalinda C

2017-01-01

The substantia nigra (SN) provides the largest dopaminergic input to the brain, projects to the striatum (the primary locus of action for antipsychotic medication), and receives GABAergic and glutamatergic inputs. This study used western blot analysis to compare protein levels of tyrosine hydroxylase (TH), glutamate decarboxylase (GAD67), and vesicular glutamate transporters (vGLUT1 and vGLUT2) in postmortem human SN in schizophrenia subjects (n=13) and matched controls (n=12). As a preliminary analysis, the schizophrenia group was subdivided by (1) treatment status: off medication (n=4) or on medication (n=9); or (2) treatment response: treatment resistant (n=5) or treatment responsive (n=4). The combined schizophrenia group had higher TH and GAD67 protein levels than controls (an increase of 69.6%, P=0.01 and 19.5%, P=0.004, respectively). When subdivided by medication status, these increases were found in the on-medication subjects (TH 88.3%, P=0.008; GAD67 40.6%, P=0.003). In contrast, unmedicated schizophrenia subjects had higher vGLUT2 levels than controls (an increase of 28.7%, P=0.041), but vGLUT2 levels were similar between medicated schizophrenia subjects and controls. Treatment-resistant subjects had significantly higher TH and GAD67 levels than controls (an increase of 121.0%, P=0.0003 and 58.7%, P=0.004, respectively). These data suggest increases in dopamine and GABA transmission in the SN in schizophrenia, with a potential relation to treatment and response.

MRI and CT contrast media extravasation: A systematic review.

PubMed

Heshmatzadeh Behzadi, Ashkan; Farooq, Zerwa; Newhouse, Jeffery H; Prince, Martin R

2018-03-01

This systematic review combines data from multiple papers on contrast media extravasation to identify factors contributing to increased extravasation risk. Data were extracted from 17 papers reporting 2191 extravasations in 1,104,872 patients (0.2%) undergoing computed tomography (CT) or magnetic resonance imaging (MRI). Extravasation rates were 0.045% for gadolinium-based contrast agents (GBCA) and nearly 6-fold higher, 0.26% for iodinated contrast agents. Factors associated with increased contrast media extravasations included: older age, female gender, using an existing intravenous (IV) instead of placing a new IV in radiology, in-patient status, use of automated power injection, high injection rates, catheter location, and failing to warm up the more viscous contrast media to body temperature. Contrast media extravasation is infrequent but nearly 6 times less frequent with GBCA for MRI compared with iodinated contrast used in CT.

Risk of Acute Kidney Injury After Intravenous Contrast Media Administration.

PubMed

Hinson, Jeremiah S; Ehmann, Michael R; Fine, Derek M; Fishman, Elliot K; Toerper, Matthew F; Rothman, Richard E; Klein, Eili Y

2017-05-01

The study objective was to determine whether intravenous contrast administration for computed tomography (CT) is independently associated with increased risk for acute kidney injury and adverse clinical outcomes. This single-center retrospective cohort analysis was performed in a large, urban, academic emergency department with an average census of 62,179 visits per year; 17,934 ED visits for patients who underwent contrast-enhanced, unenhanced, or no CT during a 5-year period (2009 to 2014) were included. The intervention was CT scan with or without intravenous contrast administration. The primary outcome was incidence of acute kidney injury. Secondary outcomes included new chronic kidney disease, dialysis, and renal transplantation at 6 months. Logistic regression modeling and between-groups odds ratios with and without propensity-score matching were used to test for an independent association between contrast administration and primary and secondary outcomes. Treatment decisions, including administration of contrast and intravenous fluids, were examined. Rates of acute kidney injury were similar among all groups. Contrast administration was not associated with increased incidence of acute kidney injury (contrast-induced nephropathy criteria odds ratio=0.96, 95% confidence interval 0.85 to 1.08; and Acute Kidney Injury Network/Kidney Disease Improving Global Outcomes criteria odds ratio=1.00, 95% confidence interval 0.87 to 1.16). This was true in all subgroup analyses regardless of baseline renal function and whether comparisons were made directly or after propensity matching. Contrast administration was not associated with increased incidence of chronic kidney disease, dialysis, or renal transplant at 6 months. Clinicians were less likely to prescribe contrast to patients with decreased renal function and more likely to prescribe intravenous fluids if contrast was administered. In the largest well-controlled study of acute kidney injury following contrast administration in the ED to date, intravenous contrast was not associated with an increased frequency of acute kidney injury. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Inhibition of di(2-ethylhexyl) phthalate (DEHP)-induced endocrine disruption by co-treatment of vitamins C and E and their mechanism of action.

PubMed

Choi, Seul Min; Lim, Duck Soo; Kim, Min Kook; Yoon, Sungpil; Kacew, Sam; Kim, Hyung Sik; Lee, Byung-Mu

2018-05-29

The endocrine disrupting actions of di(2-ethylhexyl) phthalate (DEHP) on testicular functions are postulated to involve excess free radical generation. Thus the aim of this study was to examine the ability of antioxidant vitamins C and E to prevent DEHP-induced testicular disruption in male Sprague-Dawley (SD) rats. SD male rats were administered DEHP alone or DEHP with vitamin C and/or vitamin E for 30 days. DEHP alone increased the levels of testosterone (T) and reduced estradiol (E 2 ) concentrations. Supplementation with antioxidant vitamins diminished or restored serum T levels noted in DEHP-treated rats to control values. In contrast vitamins C and E increased E 2 levels to control in rats administered DEHP. Antioxidants significantly improved the decreased testicular levels of reduced glutathione and activity of superoxide dismutase compared to DEHP-treatment alone. Co-treatment of vitamins C and E also markedly improved the reduced epididymal sperm head counts and elevated levels of malondialdehyde (MDA) or 8-hydroxydeoxyguanosine (8-OHdG) induced by DEHP treatment. These results support the concept that the adverse actions of DEHP may be related to increased free radical generation while co-treatment with vitamins C and E significantly blocked the actions of DEHP on male testicular functions.

Striatal MPP+ levels do not necessarily correlate with striatal dopamine levels after MPTP treatment in mice.

PubMed

Vaglini, F; Fascetti, F; Tedeschi, D; Cavalletti, M; Fornai, F; Corsini, G U

1996-06-01

The present study offers confirmation of the fact that an MAO-B inhibitor, (-) deprenyl and a DA uptake blocker, GBR-12909, prevent MPTP-induced striatal DA decrease. This protective effect is accompanied by an almost complete prevention of MPP+ production induced by (-) deprenyl and an accelerated MPP+ clearance induced by GBR-12909 within the striatum. Similarly, the MPTP toxicity enhancers, DDC and acetaldehyde, both increase striatal MPP+ levels, as previously reported. On the contrary, the treatment with MK 801, although uneffective in preventing the long-term MPTP-induced striatal DA decrease, causes an increase in the striatal amount of MPP+. In a similar way, the administration of nicotine in combination with MPTP produces a significant increase in the levels of striatal MPP+, which does not elicit any effect on striatal DA. The effect of clonidine is consistent with these results and in sharp contrast with the current belief that a direct relationship exists between striatal MPP+ concentrations and the degree of MPTP-induced depletion of striatal DA. In this study, using different treatments, we failed to confirm the correlation between MPP+ striatal levels and dopaminergic lesions after MPTP administration in mice. We suggest that this correlation is not a rule and exceptions may depend on a different compartimentalization of the toxic metabolite.

Monitoring therapy with MEK inhibitor U0126 in a novel Wilms tumor model in Wt1 knockout Igf2 transgenic mice using 18F-FDG PET with dual-contrast enhanced CT and MRI: early metabolic response without inhibition of tumor growth.

PubMed

Flores, Leo G; Yeh, Hsin-Hsien; Soghomonyan, Suren; Young, Daniel; Bankson, James; Hu, Qianghua; Alauddin, Mian; Huff, Vicki; Gelovani, Juri G

2013-04-01

The understanding of the role of genetic alterations in Wilms tumor development could be greatly advanced using a genetically engineered mouse models that can replicate the development and progression of this disease in human patients and can be monitored using non-invasive structural and molecular imaging optimized for renal tumors. Repetitive dual-contrast computed tomography (CT; intravenous and intraperitoneal contrast), T2-weighted magnetic resonance imaging (MRI), and delayed 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) positron emission tomography (PET) were utilized for characterization of Igf2 biallelic expression/Wt1 knockout mouse model of Wilms tumor. For CT imaging, Ioversol 678 mg/ml in 200 μl was administered i.p. followed by 100 μl injected intravenously at 20 and 15 min prior to imaging, respectively. Static PET imaging studies were acquired at 1, 2, and 3 h after i.v. administration of (18)F-FDG (400 μCi). Coronal and sagittal T1-weighted images (TE/TR 8.5/620 ms) were acquired before and immediately after i.v. injection of 0.4 ml/kg gadopentetate dimeglumine followed by T2-weighted images (TE/TR 60/300 ms). Tumor tissue samples were characterized by histopathology and immunohistochemistry for Glut1, FASN, Ki67, and CD34. In addition, six Wt1-Igf2 mice were treated with a mitogen-activated protein kinase (MEK) inhibitor U0126 (50 μmol/kg i.p.) every 4 days for 6 weeks. (18)F-FDG PET/CT imaging was repeated at different days after initiation of therapy with U0126. The percent change of initial tumor volume and SUV was compared to non-treated historic control animals. Overall, the best tumor-to-adjacent kidney contrast as well as soft tissue contrast for other abdominal organs was achieved using T2-weighted MRI. Delayed (18)F-FDG PET (3-h post (18)F-FDG administration) and dual-contrast CT (intravenous and intraperitoneal contrast) provided a more accurate anatomic and metabolic characterization of Wilms tumors in Wt1-Igf2 mice during early development and progression of renal tumors. Over the 8-month period, 46 Wt1-Igf2 mice and 8 littermate control mice were studied. Renal tumors were identified in 54.3 % of Wt1-Igf2 mice between post-natal 50-100 days. In 35.6 % of Wt1-Igf2 mice, tumors were localized in the right kidney; in 24 %, in the left kidney, while 40.4 % of Wt1-Igf2 mice had bilateral kidney tumors. Metastatic lesions were identified in 15.4 % of Wt1-Igf2 mice. Increased levels of Glut1 and IGF1R expression, high Ki67 labeling index, and a dense network of CD34+ microvessels in renal tumors was consistent with increased (18)F-FDG accumulation. Treatment with a MEK 1/2 inhibitor U0126 did not cause the inhibition of tumor growth as compared to untreated animals. However, after the first three to four doses (~2 weeks of treatment), a decrease in (18)F-FDG SUV was observed, as compared to pre-treatment levels (p < 0.05, paired Student t test), which constitutes a metabolic response. Six weeks later, despite continuing therapy, the (18)F-FDG SUV increased again to previous levels. The optimized dual contrast PET/CT imaging with early post i.v. and i.p. contrast CT and 3 h delayed PET imaging after (18)F-FDG administration provides a sensitive and reliable method for detecting early tumor lesions in this endogenous mouse model of Wilms tumor and for monitoring their growth in response to targeted therapies. Therapy with MEK inhibitor U0126 produces only a transient inhibition of tumor glycolytic activity but does not inhibit tumor growth, which is due to continuing IGF2-induced signaling from IGF1R through the PI3K-AKT-mTOR pathway.

Changes of air-tissue ratio evaluated by EBCT after cardiopulmonary resuscitation (CPR): validation in swine

NASA Astrophysics Data System (ADS)

Recheis, Wolfgang A.; Schuster, Antonius H.; Kleinsasser, Axel; Loeckinger, Alexander; Hoermann, Christoph; zur Nedden, Dieter

2001-05-01

The purpose was to evaluate changes of the air-tissue ratio (ATR) in previously defined regions of interest after cardiopulmonary resuscitation (CPR) in porcine model. Eight anesthetized and ventilated pigs we scanned in supine position before and 30 minutes after CPR at two different constant PEEP levels (5 cm H2O, 15 cm H2O). Volume scans were obtained using 6 mm slices. The gray values of the lung were divided into steps of 100 HU in order to get access to the changes of ATR. ATR was evaluated in ventral, intermediate and dorsal regions of the lung. CPR for 9 minutes led to an uneven distribution of ventilation. In the ventral region, areas with high ATR increased. Areas with normal ATR decreased. In contrast the dorsal regions with low ATR increased. ATR in the intermediate regions remained almost unchanged. Using the higher PEEP level, areas with normal ATR showed a marked increase accompanied by a decrease of areas with low ATR. After CPR, an uneven distribution of lung aeration was detected. According to the impaired hemodynamics, areas with normal ATR decreased and areas with high and low ATR increased. Using higher PEEP levels improved lung aeration.

Non-intromissive mating stimuli are sufficient to enhance sexual behaviors in ovariectomized female rats.

PubMed

Blaustein, Jeffrey D; Farrell, Sara; Ghavami, Gila; Laroche, Julie; Mohan, Govini

2009-03-01

When ovariectomized/adrenalectomized female rats, injected with subthreshold doses of estradiol are given copulatory stimulation by a male rat at half hour intervals, the level of lordosis gradually increases over the course of a few hours. We tested the hypothesis that paracopulatory behaviors (behaviors that occur repetitively prior to and between mounts), also generally considered to be heavily dependent on progesterone, are enhanced by this stimulation as well. We have reported previously that the enhancement of copulatory behavior is dependent to a large extent on intromissive stimulation by the male. In the present study, mating stimulation induced high levels of paracopulatory behaviors, as well as lordosis. Surprisingly, though, and in contrast to previous findings, this increase was seen not only in rats receiving intromissive stimulation, but in those receiving non-intromissive stimulation as well. Furthermore, intromissive stimulation induced high levels of rejection behavior. In a subsequent experiment, experimenter-induced, mechanical stimulation increased only rejection behaviors, not copulatory behavior. The results collectively demonstrate that, under the conditions used in these experiments, non-intromissive stimulation is sufficient for inducing both copulatory and paracopulatory behaviors in estradiol-primed rats. However, under the conditions used in these studies, intromissive stimulation increases rejection behaviors.

Physical stress primes the immune response of Galleria mellonella larvae to infection by Candida albicans.

PubMed

Mowlds, Peter; Barron, Aoife; Kavanagh, Kevin

2008-05-01

Larvae of the greater wax moth (Galleria mellonella) that had been subjected to physical stress by shaking in cupped hands for 2 min showed reduced susceptibility to infection by Candida albicans when infected 24 h after the stress event. Physically stressed larvae demonstrated an increase in haemocyte density and elevated mRNA levels of galiomicin and an inducible metalloproteinase inhibitor (IMPI) but not transferrin or gallerimycin. In contrast, previous work has demonstrated that microbial priming of larvae resulted in the induction of all four genes. Examination of the expression of proteins in the insect haemolymph using 2D electrophoresis and MALDI TOF analysis revealed an increase in the intensity of a number of peptides showing some similarities with proteins associated with the insect immune response to infection. This study demonstrates that non-lethal physical stress primes the immune response of G. mellonella and this is mediated by elevated haemocyte numbers, increased mRNA levels of genes coding for two antimicrobial peptides and the appearance of novel peptides in the haemolymph. This work demonstrates that physical priming increases the insect immune response but the mechanism of this priming is different to that induced by low level exposure to microbial pathogens.

Characterizing visual asymmetries in contrast perception using shaded stimuli.

PubMed

Chacón, José; Castellanos, Miguel Ángel; Serrano-Pedraza, Ignacio

2015-01-01

Previous research has shown a visual asymmetry in shaded stimuli where the perceived contrast depended on the polarity of their dark and light areas (Chacón, 2004). In particular, circles filled out with a top-dark luminance ramp were perceived with higher contrast than top-light ones although both types of stimuli had the same physical contrast. Here, using shaded stimuli, we conducted four experiments in order to find out if the perceived contrast depends on: (a) the contrast level, (b) the type of shading (continuous vs. discrete) and its degree of perceived three-dimensionality, (c) the orientation of the shading, and (d) the sign of the perceived contrast alterations. In all experiments the observers' tasks were to equate the perceived contrast of two sets of elements (usually shaded with opposite luminance polarity), in order to determine the subjective equality point. Results showed that (a) there is a strong difference in perceived contrast between circles filled out with luminance ramp top-dark and top-light that is similar for different contrast levels; (b) we also found asymmetries in contrast perception with different shaded stimuli, and this asymmetry was not related with the perceived three-dimensionality but with the type of shading, being greater for continuous-shading stimuli; (c) differences in perceived contrast varied with stimulus orientation, showing the maximum difference on vertical axis with a left bias consistent with the bias found in previous studies that used visual-search tasks; and (d) asymmetries are consistent with an attenuation in perceived contrast that is selective for top-light vertically-shaded stimuli.

Inner-city older blacks have high levels of functional disability.

PubMed

Miller, D K; Carter, M E; Miller, J P; Fornoff, J E; Bentley, J A; Boyd, S D; Rogers, J H; Cox, M N; Morley, J E; Lui, L Y; Coe, R M

1996-10-01

To describe the frequency and severity of functional problems in two groups of noninstitutionalized inner-city blacks aged 70 years and older contrasted with results from appropriate groups of white and black older adults and with the goals of the Healthy People 2000 program. Cross-sectional descriptive study. Community-based samples. A population-based sample of 416 older adults living in a 3.5-square mile catchment area in north St. Louis (NSL), Missouri, and a sample of 197 older residents living in public housing in East St. Louis (ESL), Illinois. Health status, preventive health activities, health services utilization, and risks for progressive frailty were assessed by self report and observation using well validated, standardized instruments. Whenever possible, comparison data were derived from national datasets, original samples used to validate the measures, and other useful comparison groups. The NSL sample had somewhat better health status and risk for progressive disability than the ESL sample. However, compared with national or regional reference groups using age-gender adjustments, both study groups demonstrated increased levels of dependence in intermediate activities of daily living, restricted activity days, inability to walk one-half mile without assistance, reported poor vision, living alone, and limited income compared with both older whites and blacks, and increased levels of worsening health, inability to perform heavy work around the house, never walking a mile or more, and currently unmarried versus whites with variable decrements versus blacks. Contrasted with other comparison groups, the two samples had increased body fat; consistent decrements in gait speed, timed chair stands, timed one-leg balance, and frequency of preventive exercise; and lower levels of dental care; results relative to physician visits and hospital days were mixed. They also had high levels of measured visual and hearing impairments, unmet needs for home delivered meals, and problems with false teeth. Deficiencies compared with the goals of Healthy People 2000 were large. The special attributes of inner-city blacks, including poverty and access to and acceptance of remedial programs, will have to be considered if the goals of Healthy People 2000 are to be met in this important and growing segment of older Americans. 44:0000-0000, 1996.

Quantitative assessment of placental perfusion by contrast-enhanced ultrasound in macaques and human subjects

PubMed Central

Roberts, Victoria HJ; Lo, Jamie O; Salati, Jennifer A; Lewandowski, Katherine S; Lindner, Jonathan R; Morgan, Terry K; Frias, Antonio E

2016-01-01

Background The utero-placental vascular supply is a critical determinant of placental function and fetal growth. Current methods for the in vivo assessment of placental blood flow are limited. Objective Here we demonstrate the feasibility of utilizing contrast-enhanced ultrasound to visualize and quantify perfusion kinetics in the intervillous space of the primate placenta. Study design Pregnant Japanese macaques were studied at mid second trimester and in the early third trimester. Markers of injury were assessed in placenta samples from animals with or without contrast-enhanced ultrasound exposure (n=6/group). Human subjects were recruited immediately prior to scheduled first trimester pregnancy termination. All studies were performed with maternal intravenous infusion of lipid-shelled octofluoropropane microbubbles with image acquisition using a multipulse contrast-specific algorithm with destruction-replenishment analysis of signal intensity for assessment of perfusion. Results In macaques, rate of perfusion in the intervillous space was increased with advancing gestation. No evidence of microvascular hemorrhage or acute inflammation was found in placental villous tissue and expression levels of caspase-3, nitrotyrosine and HSP70 as markers of apoptosis, nitrative and oxidative stress respectively were unchanged by contrast-enhanced ultrasound exposure. In humans, placental perfusion was visualized at 11wks gestation and preliminary data reveal regional differences in intervillous space perfusion within an individual placenta. By electron microscopy, we demonstrate no evidence of ultrastructure damage to the microvilli on the syncytiotrophoblast following first trimester ultrasound studies. Conclusions Use of contrast-enhanced ultrasound did not result in placental structural damage, and was able to identify intervillous space perfusion rate differences within a placenta. Contrast-enhanced ultrasound may offer a safe clinical tool for the identification of pregnancies at-risk for vascular insufficiency; early recognition may facilitate intervention and improved pregnancy outcomes. PMID:26928151

Acute mental stress but not enforced muscle activity transiently increases natural cytotoxicity in spontaneously hypertensive rats.

PubMed

Jonsdottir, I H; Johansson, C; Asea, A; Hellstrand, K; Hoffmann, P

1996-08-01

The influence of acute mental stress and the effect of electrically induced skeletal muscle contractions on natural cytotoxicity in vivo was investigated in spontaneously hypertensive rats Natural cytotoxicity in vivo was measured as the clearance of injected 51Cr-labelled YAC-1 lymphoma cells from the lungs, which are specifically lysed by natural killer cells. The mental stress consisted of an air jet directed towards the animals in their cage for 25 min. During the mental stress there was a significant increase in natural cytotoxicity. Thus, retained radioactivity in the lungs was decreased to 74 +/- 6% of the control levels which was set to 100% (P < 0.01). This augmentation of YAC-1-cell clearance could be blocked with the beta-adrenergic receptor antagonist Timolol. Two hours after termination of the air stress, in vivo cytotoxicity had returned to control levels. In contrast, acute physical stress, consisting of electrically induced muscle contractions for 60 min, had no significant effects on in vivo cytotoxicity, either during the stimulation or 1, 2 or 24 h after the stimulation. Further, significantly increased plasma levels of adrenaline were seen after the air jet stress, but not after muscle stimulation. There were no significant changes in plasma noradrenaline levels either after air stress or muscle stimulation. These results indicate that changes in in vivo cytotoxicity after mild mental stress are dependent on increased plasma catecholamine levels while acute physical stress without changes in catecholamine levels, does not influence in vivo cytotoxicity.

Effect of atmospheric carbon dioxide levels and nitrate fertilization on glucosinolate biosynthesis in mechanically damaged Arabidopsis plants.

PubMed

Paudel, Jamuna Risal; Amirizian, Alexandre; Krosse, Sebastian; Giddings, Jessica; Ismail, Shoieb Akaram Arief; Xia, Jianguo; Gloer, James B; van Dam, Nicole M; Bede, Jacqueline C

2016-03-22

Increased atmospheric carbon dioxide (CO2) levels predicted to occur before the end of the century will impact plant metabolism. In addition, nitrate availability will affect metabolism and levels of nitrogen-containing defense compounds, such as glucosinolates (GSLs). We compared Arabidopsis foliar metabolic profile in plants grown under two CO2 regimes (440 vs 880 ppm), nitrate fertilization (1 mM vs 10 mM) and in response to mechanical damage of rosette leaves. Constitutive foliar metabolites in nitrate-limited plants show distinct global patterns depending on atmospheric CO2 levels; in contrast, plants grown under higher nitrate fertilization under elevated atmospheric CO2 conditions have a unique metabolite signature. Nitrate fertilization dampens the jasmonate burst in response to wounding in plants grown at elevated CO2 levels. Leaf GSL profile mirrors the jasmonate burst; in particular, indole GSLs increase in response to damage in plants grown at ambient CO2 but only in nitrate-limited plants grown under elevated CO2 conditions. This may reflect a reduced capacity of C3 plants grown under enriched CO2 and nitrate levels to signal changes in oxidative stress and has implications for future agricultural management practices.

Winners and losers as mangrove, coral and seagrass ecosystems respond to sea-level rise in Solomon Islands

NASA Astrophysics Data System (ADS)

Albert, Simon; Saunders, Megan I.; Roelfsema, Chris M.; Leon, Javier X.; Johnstone, Elizabeth; Mackenzie, Jock R.; Hoegh-Guldberg, Ove; Grinham, Alistair R.; Phinn, Stuart R.; Duke, Norman C.; Mumby, Peter J.; Kovacs, Eva; Woodroffe, Colin D.

2017-09-01

A 2007 earthquake in the western Solomon Islands resulted in a localised subsidence event in which sea level (relative to the previous coastal settings) rose approximately 30-70 cm, providing insight into impacts of future rapid changes to sea level on coastal ecosystems. Here, we show that increasing sea level by 30-70 cm can have contrasting impacts on mangrove, seagrass and coral reef ecosystems. Coral reef habitats were the clear winners with a steady lateral growth from 2006-2014, yielding a 157% increase in areal coverage over seven years. Mangrove ecosystems, on the other hand, suffered the largest impact through a rapid dieback of 35% (130 ha) of mangrove forest in the study area after subsidence. These forests, however, had partially recovered seven years after the earthquake albeit with a different community structure. The shallow seagrass ecosystems demonstrated the most dynamic response to relative shifts in sea level with both losses and gains in areal extent at small scales of 10-100 m. The results of this study emphasize the importance of considering the impacts of sea-level rise within a complex landscape in which winners and losers may vary over time and space.

Aqueous extract of pecan nut shell (Carya illinoensis [Wangenh.] K. Koch) exerts protection against oxidative damage induced by cyclophosphamide in rat testis.

PubMed

Benvegnu, Dalila M; Barcelos, Raquel C S; Roversi, Katiane; Boufleur, Nardelli; Pase, Camila S; Trevizol, Fabiola; Segat, Hecson J; Dias, Verônica T; Dolci, Geisa S; Antoniazzi, Caren T D; Reckziegel, Patricia; Lima, Fernanda; de Lima, Luiz A R; de Carvalho, Leandro M; da Silva Junior, Valdemiro A; Burger, Marilise E

2013-01-01

This study investigated the protective effect of pecan nut (Carya illinoensis) shell aqueous extract (AE) on the oxidative and morphological status of rat testis treated with cyclophosphamide (CP). Wistar rats received water or AE (5%) ad libitum for 37 days. On day 30, half of each group received a single intraperitoneal administration of vehicle or CP 200 mg/kg. After 7 days, the animals were killed and their testis removed. Rats treated with CP presented reduced levels of lactate dehydrogenase, vitamin C, and gluthatione, as well as decreased catalase activity, increased lipid peroxidation levels and superoxide dismutase activity, no alteration in carbonyl protein levels, and a loss of morphological testicular integrity. In contrast, cotreatment with pecan shell AE totally prevented the decrease of lactate dehydrogenase and vitamin C levels and catalase activity and partially prevented the depletion of gluthatione levels. Moreover, it totally prevented the increase in superoxide dismutase activity and lipid peroxidation levels and maintained testicular integrity. These findings show the protective role of pecan shell AE in CP-induced testicular toxicity. The use of this phytotherapy may be considered to minimize deleterious effects related to this chemotherapy.

Influence of time, temperature and coagulation on the measurement of C3, C3 split products and C4.

PubMed

Sinosich, M J; Teisner, B; Brandslund, I; Fisher, M; Grudzinskas, J G

1982-11-26

Quantitative and qualitative immunoelectrophoretic analyses of circulating C3, C3 split products and C4 were performed in matched EDTA plasma and serum obtained from 5 normal subjects and stored for up to 48 h at room temperature (18 degrees C-22 degrees C) and 4 degrees C. Fluctuations in apparent levels of C3 were greater in serum than plasma stored at room temperature, a fall in levels seen by 24 h being followed by a significant increase. By contrast, levels of C3 did not alter if stored at 4 degrees C. C4 levels in both EDTA plasma and serum remained unchanged for 24 h, a slight decrease being seen at 48 h. Levels of C4 remained constant if samples were stored at 4 degrees C. Crossed immunoelectrophoresis revealed a significant progressive decrease in C3 levels and a simultaneous increase in C3c occurring after 4 h in serum and 8 h in EDTA plasma, stored at room temperature. In studies conducted at 4 degrees C, similar but delayed fluctuations were seen. A progressive and significant increase in C3d levels was seen in both plasma and serum samples stored at room temperature, levels rising to 276% (plasma) and 308% (serum) of levels seen at zero time. At 4 degrees C marginal increases in C3d levels only were observed. These results suggest that in vitro degradation of C3 and C4 are readily facilitated by temperature, time and coagulation, and that conditions of collection and storage of samples must be optimized for the accurate definition of activation of the complement cascade.

Using Lymphocyte and Plasma Hsp70 as Biomarkers for Assessing Coke Oven Exposure among Steel Workers

PubMed Central

Yang, Xiaobo; Zheng, Jinping; Bai, Yun; Tian, Fengjie; Yuan, Jing; Sun, Jianya; Liang, Huashan; Guo, Liang; Tan, Hao; Chen, Weihong; Tanguay, Robert M.; Wu, Tangchun

2007-01-01

Background Hsp70, an early-response protein induced when organisms are confronted with simple or complicated environmental stresses, can act as either a cellular protector or a danger signal. Objectives The goal of this study was to evaluate levels of lymphocyte and/or plasma Hsp70 as biomarkers for assessing exposure response to complex coke oven emissions (COEs). Methods We recruited 101 coke oven workers and determined levels of polycyclic aromatic hydrocarbon (PAH) exposure, urinary 1-hydroxypyrene (1-OHP), genotoxic damage by comet assay and micronuclei test, and other markers of damage, including plasma malondialdehyde (MDA) and lactate dehydrogenase (LDH). These were compared to levels of lymphocyte (intra-cellular) and plasma (extracellular) Hsp70 using Western blots and enzyme-linked immunosorbent assays (ELISA), respectively. Results We observed a COEs-related dose-dependent increase in levels of DNA damage, micronuclei rate, MDA concentration, and LDH activity. Lymphocyte Hsp70 levels increased in the intermediate-exposure group (1.39 ± 0.88) but decreased in the high-exposure group (1.10 ± 0.55), compared with the low-exposure group. In contrast, plasma Hsp70 levels progressively increased as the dose of exposure increased. Negative correlations were seen between lymphocyte Hsp70 levels and olive tail moment and LDH activity in the intermediate- and high-exposure groups. However, we observed positive correlations between plasma Hsp70 levels and LDH activity in the low and intermediate groups. Conclusions In workers exposed to COEs, high lymphocyte Hsp70 levels may provide protection and high plasma Hsp70 levels may serve as a danger marker. Larger validation studies are needed to establish the utility of Hsp70 as a response marker. PMID:18007987

Effects of gut microbiota and time of treatment on tissue levels of green tea polyphenols in mice.

PubMed

Liu, Anna B; Tao, Siyao; Lee, Mao-Jung; Hu, Qi; Meng, Xiaofeng; Lin, Yong; Yang, Chung S

2018-05-08

The previous studies have shown that tea polyphenols are metabolized by gut microbiota. This study investigated the effect of gut microbiota on the bioavailability, tissue levels, and degradation of tea polyphenols. Mice were treated with antibiotics (ampicillin/sulfamethoxazole/trimethoprim) in drinking water and the control mice received water for 11 days, and they were given an AIN93M diet enriched with 0.32% of Polyphenon E. The levels of catechins and their metabolites (if present) in the serum, liver, urine, and fecal samples were determined by high-performance liquid chromatography. The results showed that treatment with antibiotics significantly increased the levels of the major polyphenol, (-)-epigallocatechin-3-gallate (EGCG), in serum and liver samples. Antibiotics also raised the levels of some catechins in urine and fecal samples but decreased the levels of their metabolites. These results suggest that antibiotics eliminated gut microbes and increased the bioavailabilities of these tea catechins. In a second study, mice were given different concentrations of green tea infusions as the drinking fluid. The plasma levels of EGCG and (-)-epicatechin-3-gallate (ECG) at day 112 were significantly lower than those at day 5. The urine levels of EGCG and ECG increased in the first 4 or 5 days, and then decreased to much lower levels at day 23 and beyond. In contrast, the levels of (-)-epigallocatechin and (-)-epicatechin showed a trend of increase during the 112-day experiment, likely owing to microbial hydrolysis of EGCG and ECG. Both sets of experiments support the idea that the degradation of EGCG and ECG by gut microbiota decreases their bioavailabilities. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Loss of adiabaticity with increasing tunneling gap in nonintegrable multistate Landau-Zener models

NASA Astrophysics Data System (ADS)

Malla, Rajesh K.; Raikh, M. E.

2017-09-01

We consider the simplest nonintegrable model of the multistate Landau-Zener transition. In this model, two pairs of levels in two tunnel-coupled quantum dots are swept past each other by the gate voltage. Although this 2 ×2 model is nonintegrable, it can be solved analytically in the limit when the interlevel energy distance is much smaller than their tunnel splitting. The result is contrasted to the similar 2 ×1 model, in which one of the dots contains only one level. The latter model does not allow interference of the virtual transition amplitudes, and it is exactly solvable. In the 2 ×1 model, the probability for a particle, residing at time t →-∞ in one dot, to remain in the same dot at t →∞ , falls off exponentially with tunnel coupling. By contrast, in the 2 ×2 model, this probability grows rapidly with tunnel coupling. The physical origin of this growth is the formation of the tunneling-induced collective states in the system of two dots. This can be viewed as a manifestation of the Dicke effect.

Hearing in noisy environments: noise invariance and contrast gain control

PubMed Central

Willmore, Ben D B; Cooke, James E; King, Andrew J

2014-01-01

Contrast gain control has recently been identified as a fundamental property of the auditory system. Electrophysiological recordings in ferrets have shown that neurons continuously adjust their gain (their sensitivity to change in sound level) in response to the contrast of sounds that are heard. At the level of the auditory cortex, these gain changes partly compensate for changes in sound contrast. This means that sounds which are structurally similar, but have different contrasts, have similar neuronal representations in the auditory cortex. As a result, the cortical representation is relatively invariant to stimulus contrast and robust to the presence of noise in the stimulus. In the inferior colliculus (an important subcortical auditory structure), gain changes are less reliably compensatory, suggesting that contrast- and noise-invariant representations are constructed gradually as one ascends the auditory pathway. In addition to noise invariance, contrast gain control provides a variety of computational advantages over static neuronal representations; it makes efficient use of neuronal dynamic range, may contribute to redundancy-reducing, sparse codes for sound and allows for simpler decoding of population responses. The circuits underlying auditory contrast gain control are still under investigation. As in the visual system, these circuits may be modulated by factors other than stimulus contrast, forming a potential neural substrate for mediating the effects of attention as well as interactions between the senses. PMID:24907308

Diffuse radiation increases global ecosystem-level water-use efficiency

NASA Astrophysics Data System (ADS)

Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

2012-12-01

Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

Cosmos 1887 mission overview - Effects of microgravity on rat body and adrenal weights and plasma constituents

NASA Technical Reports Server (NTRS)

Grindeland, R. E.; Vasques, M.; Arnaud, S. B.; Popova, I. A.

1990-01-01

Tissues of male, specific pathogen-free Wistar rats flown on the Cosmos 1887 biosatellite are studied. First the mission is described, and then analytical methods are outlined. It is noted that flight rats grew more slowly and had larger adrenal glands than earth gravity controls. Analysis of plasma reveals increased concentrations of hepatic alkaline phosphatase, glucose, urea nitrogen, and creatinine in flight rats. In contrast, electrolytes, total protein, albumin, corticosteron, prolactin, and immunoreactive growth hormone levels are unchanged. However, testosterone concentration is marginally decreased after flight and thyroid hormone levels are suggestive of reduced thyroid function.

mRNA Transcript Abundance during Plant Growth and the Influence of Li + Exposure

DOE PAGES

Duff, M. C.; Kuhne, W. W.; Halverson, N. V.; ...

2014-10-23

Lithium (Li) toxicity in plants is, at a minimum, a function of Li + concentration, exposure time, species and growth conditions. Most plant studies with Li + focus on short-term acute exposures. This study examines short- and long-term effects of Li + exposure in Arabidopsis with Li + uptake studies and measured shoot mRNA transcript abundance levels in treated and control plants. Stress, pathogen-response and arabinogalactan protein genes were typically more up-regulated in older (chronic, low level) Li +-treatment plants and in the much younger plants from acute high-level exposures. The gene regulation behavior of high-level Li + resembled priormore » studies due to its influence on: inositol synthesis, 1-aminocyclopropane-1-carboxylate synthases and membrane ion transport. In contrast, chronically-exposed plants had gene regulation responses that were indicative of pathogen, cold, and heavy-metal stress, cell wall degradation, ethylene production, signal transduction, and calcium-release modulation. Acute Li + exposure phenocopies magnesium-deficiency symptoms and is associated with elevated expression of stress response genes that could lead to consumption of metabolic and transcriptional energy reserves and the dedication of more resources to cell development. In contrast, chronic Li + exposure increases expression signal transduction genes. The identification of new Li +-sensitive genes and a gene-based “response plan” for acute and chronic Li + exposure are delineated.« less

Innovation and social transmission in experimental micro-societies: exploring the scope of cumulative culture in young children.

PubMed

McGuigan, Nicola; Burdett, Emily; Burgess, Vanessa; Dean, Lewis; Lucas, Amanda; Vale, Gillian; Whiten, Andrew

2017-12-05

The experimental study of cumulative culture and the innovations essential to it is a young science, with child studies so rare that the scope of cumulative cultural capacities in childhood remains largely unknown. Here we report a new experimental approach to the inherent complexity of these phenomena. Groups of 3-4-year-old children were presented with an elaborate array of challenges affording the potential cumulative development of a variety of techniques to gain increasingly attractive rewards. In contrast to a prior study, we found evidence for elementary forms of cumulative cultural progress, with inventions of solutions at lower levels spreading to become shared innovations, and some children then building on these to create more advanced but more rewarding innovations. This contrasted with markedly more constrained progress when children worked only by themselves, or if groups faced only the highest-level challenges from the start. Further experiments that introduced higher-level inventions via the inclusion of older children, or that created ecological change, with the easiest habitual solutions no longer possible, encouraged higher levels of cumulative innovation. Our results show children are not merely 'cultural sponges', but when acting in groups, display the beginnings of cycles of innovation and observational learning that sustain cumulative progress in problem solving.This article is part of the themed issue 'Process and pattern in innovations from cells to societies'. © 2017 The Author(s).

mRNA Transcript abundance during plant growth and the influence of Li(+) exposure.

PubMed

Duff, M C; Kuhne, W W; Halverson, N V; Chang, C-S; Kitamura, E; Hawthorn, L; Martinez, N E; Stafford, C; Milliken, C E; Caldwell, E F; Stieve-Caldwell, E

2014-12-01

Lithium (Li) toxicity in plants is, at a minimum, a function of Li(+) concentration, exposure time, species and growth conditions. Most plant studies with Li(+) focus on short-term acute exposures. This study examines short- and long-term effects of Li(+) exposure in Arabidopsis with Li(+) uptake studies and measured shoot mRNA transcript abundance levels in treated and control plants. Stress, pathogen-response and arabinogalactan protein genes were typically more up-regulated in older (chronic, low level) Li(+)-treatment plants and in the much younger plants from acute high-level exposures. The gene regulation behavior of high-level Li(+) resembled prior studies due to its influence on: inositol synthesis, 1-aminocyclopropane-1-carboxylate synthases and membrane ion transport. In contrast, chronically-exposed plants had gene regulation responses that were indicative of pathogen, cold, and heavy-metal stress, cell wall degradation, ethylene production, signal transduction, and calcium-release modulation. Acute Li(+) exposure phenocopies magnesium-deficiency symptoms and is associated with elevated expression of stress response genes that could lead to consumption of metabolic and transcriptional energy reserves and the dedication of more resources to cell development. In contrast, chronic Li(+) exposure increases expression signal transduction genes. The identification of new Li(+)-sensitive genes and a gene-based "response plan" for acute and chronic Li(+) exposure are delineated. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The stress hormone cortisol blocks perceptual learning in humans.

PubMed

Dinse, Hubert R; Kattenstroth, J C; Lenz, M; Tegenthoff, M; Wolf, O T

2017-03-01

Cortisol, the primary glucocorticoid (GC) in humans, influences neuronal excitability and plasticity by acting on mineralocorticoid and glucocorticoid receptors. Cellular studies demonstrated that elevated GC levels affect neuronal plasticity, for example through a reduction of hippocampal long-term potentiation (LTP). At the behavioural level, after treatment with GCs, numerous studies have reported impaired hippocampal function, such as impaired memory retrieval. In contrast, relatively little is known about the impact of GCs on cortical plasticity and perceptual learning in adult humans. Therefore, in this study, we explored the impact of elevated GC levels on human perceptual learning. To this aim, we used a training-independent learning approach, where lasting changes in human perception can be induced by applying passive repetitive sensory stimulation (rss), the timing of which was determined from cellular LTP studies. In our placebo-controlled double-blind study, we used tactile LTP-like stimulation to induce improvements in tactile acuity (spatial two-point discrimination). Our results show that a single administration of hydrocortisone (30mg) completely blocked rss-induced changes in two-point discrimination. In contrast, the placebo group showed the expected rss-induced increase in two-point discrimination of over 14%. Our data demonstrate that high GC levels inhibit rss-induced perceptual learning. We suggest that the suppression of LTP, as previously reported in cellular studies, may explain the perceptual learning impairments observed here. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Predictors for contrast media-induced nephropathy and long-term survival: Prospectively assessed data from the randomized controlled Dialysis-Versus-Diuresis (DVD) trial

PubMed Central

Hölscher, Birgit; Heitmeyer, Christine; Fobker, Manfred; Breithardt, Günter; Schaefer, Roland M; Reinecke, Holger

2008-01-01

BACKGROUND: Among the numerous studies concerning contrast media-induced nephropathy (CIN), there was no prospective trial that provided data on the long-term outcomes. OBJECTIVES: To prospectively assess predictors of CIN and long-term outcomes of affected patients. METHODS: Four hundred twelve consecutive patients with serum creatinine levels of 115 μmol/L to 309 μmol/L (1.3 mg/dL to 3.5 mg/dL) undergoing elective coronary angiography were included. Patients were randomly assigned to periprocedural hydration alone, hydration plus onetime hemodialysis or hydration plus N-acetylcysteine. RESULTS: Multivariate logistic regression identified the following as predictors of CIN within 72 h (equivalent to an increase in creatinine 44.2 μmol/L [0.5 mg/dL] or more) : prophylactic postprocedural hemodialysis (OR 2.86, 95% CI 1.07 to 7.69), use of angiotensin-converting enzyme inhibitors (OR 6.16, 95% CI 2.01 to 18.93), baseline glomerular filtration rate (OR 0.94, 95% CI 0.90 to 0.98) and the amount of contrast media given (OR 1.01, 95% CI 1.00 to 1.01). With regard to long-term outcome (mean follow-up 649 days), multivariate Cox regression models found elevated creatinine levels at 30 days (hazard rate ratio [HRR] 5.48, 95% CI 2.85 to 10.53), but not CIN within 72 h (HRR 1.12, 95% CI 0.63 to 2.02), to be associated with increased mortality. In addition, independent predictors for death during follow-up included left ventricular ejection fraction lower than 35% (HRR 4.01, 95% CI 2.22 to 7.26), serum phosphate (HRR 1.64, 95% CI 1.10 to 2.43) and hemoglobin (HRR 0.80, 95% CI 0.67 to 0.96). CONCLUSION: From the present prospective trial, performance of post-procedural hemodialysis, use of angiotensin-converting enzyme inhibitors, reduced baseline glomerular filtration rate and amount of contrast media were independent predictors of CIN within 72 h after catheterization. Assessing renal function after 30 days, rather than within 72 h, seemed to be more predictive for patients’ long-term survival. PMID:18987758

Younger and older adults' perception of the Wundt-Hering illusion as a function of display illumination and reflectance contrast.

PubMed

Astor-Stetson, E; Lane, S

1991-08-01

Reflectance contrast (i.e., black as compared to grey figures on white ground) and display illumination were manipulated to vary the brightness contrast of Wundt-Hering figures. 16 college students and 16 older adults were presented with high, medium, and low reflectance contrast figures. For half the participants, display illumination was manipulated by covering the figures with a .5 yellow neutral density filter. Magnitude of the illusion increased significantly with increased reflectance contrast for college students, and college students were significantly more susceptible to the high contrast figures than were older adults. Display illumination had no effect on the performance of either group.

Effect of fat content and homogenization under conventional or ultra-high-pressure conditions on interactions between proteins in rennet curds.

PubMed

Zamora, A; Trujillo, A J; Armaforte, E; Waldron, D S; Kelly, A L

2012-09-01

The objective of this study was to investigate the influence of conventional and ultra-high-pressure homogenization on interactions between proteins within drained rennet curds. The effect of fat content of milk (0.0, 1.8, or 3.6%) and homogenization treatment on dissociation of proteins by different chemical agents was thus studied. Increasing the fat content of raw milk increased levels of unbound whey proteins and calcium-bonded caseins in curds; in contrast, hydrophobic interactions and hydrogen bonds were inhibited. Both homogenization treatments triggered the incorporation of unbound whey proteins in the curd, and of caseins through ionic bonds involving calcium salts. Conventional homogenization-pasteurization enhanced interactions between caseins through hydrogen bonds and hydrophobic interactions. In contrast, ultra-high-pressure homogenization impaired hydrogen bonding, led to the incorporation of both whey proteins and caseins through hydrophobic interactions and increased the amount of unbound caseins. Thus, both homogenization treatments provoked changes in the protein interactions within rennet curds; however, the nature of the changes depended on the homogenization conditions. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Structure analyses of the explosive extratropical cyclone: A case study over the Northwestern Pacific in March 2007

NASA Astrophysics Data System (ADS)

Wang, Shuai; Fu, Gang; Pang, Huaji

2017-12-01

The synoptic situation and mesoscale structure of an explosive extratropical cyclone over the Northwestern Pacific in March 2007 are investigated through weather station observations and data reanalysis. The cyclone is located beneath the poleward side of the exit of a 200 hPa jet, which is a strong divergent region aloft. At mid-level, the cyclone lies on the downstream side of a well-developed trough, where a strong ascending motion frequently occurs. Cross-section analyses with weather station data show that the cyclone has a warm and moist core. A `nose' of the cold front, which is characterized by a low-level protruding structure in the equivalent potential temperature field, forms when the cyclone moves offshore. This `nose' structure is hypothesized to have been caused by the heating effect of the Kuroshio Current. Two low-level jet streams are also identified on the western and eastern sides of the cold front. The western jet conveys cold and dry air at 800-900 hPa. The wind in the northern part is northeasterly, and the wind in the southern part is northwesterly. By contrast, the eastern jet carries warm and moist air into the cyclone system, ascending northward from 900 hPa to 600-700 hPa. The southern part is dominated by the southerly wind, and the wind in the northern part is southwesterly. The eastern and western jets significantly increase the air temperature and moisture contrast in the vicinity of the cold front. This increase could play an important role in improving the rapid cyclogenesis process.

Npr1 Ser/Thr Protein Kinase Links Nitrogen Source Quality and Carbon Availability with the Yeast Nitrate Transporter (Ynt1) Levels*

PubMed Central

Martín, Yusé; González, Yelvis V.; Cabrera, Elisa; Rodríguez, Celia; Siverio, José M.

2011-01-01

Ynt1, the single high affinity nitrate and nitrite transporter of the yeast Hansenula polymorpha, is regulated by the quality of nitrogen sources. Preferred nitrogen sources cause Ynt1 dephosphorylation, ubiquitinylation, endocytosis, and vacuolar degradation. In contrast, under nitrogen limitation Ynt1 is phosphorylated and sorted to the plasma membrane. We show here the involvement of the Ser/Thr kinase HpNpr1 in Ynt1 phosphorylation and regulation of Ynt1 levels in response to nitrogen source quality and the availability of carbon. In Δnpr1, Ynt1 phosphorylation does not take place, although Ynt1 ubiquitin conjugates increase. As a result, in this strain Ynt1 is sorted to the vacuole, from both plasma membrane and the later biosynthetic pathway in nitrogen-free conditions and nitrate. In contrast, overexpression of NPR1 blocks down-regulation of Ynt1, increasing Ynt1 phosphorylation at Ser-244 and -246 and reducing ubiquitinylation. Furthermore, Npr1 is phosphorylated in response to the preferred nitrogen sources, and indeed it is dephosphorylated in nitrogen-free medium. Under conditions where Npr1 is phosphorylated, Ynt1 is not and vice versa. We show for the first time that carbon starvation leads to Npr1 phosphorylation, whereas Ynt1 is dephosphorylated and degraded in the vacuole. Rapamycin prevents this, indicating a possible role of the target of rapamycin signaling pathway in this process. We concluded that Npr1 plays a key role in adapting Ynt1 levels to the nitrogen quality and availability of a source of carbon. PMID:21652715

Assessment of thermal stress adaptation by monitoring Hsp70 and MnSOD in the freshwater gastropod, Bellamya bengalensis (Lamark 1882).

PubMed

Dutta, Sangita Maiti; Mustafi, Soumyajit Banerjee; Raha, Sanghamitra; Chakraborty, Susanta Kumar

2014-12-01

Expression of the stress biomarkers 70-kDa heat shock proteins (Hsp70) and manganese superoxide dismutase (MnSOD) was measured as the molecular basis of adaptive response against increased experimental temperatures (32-40 °C for a span of 24-72 h) on the fresh water molluscan species, Bellamya bengalensis (Lamark 1882). The experimental snail specimens were collected during summer and winter seasons from two contrasting wetlands: an ecorestored (free from human interference) site (SI) and other experiencing anthropogenic stresses (SII). The mortality rate of the B. bengalensis and the immunoblotting of MnSOD and Hsp70 of their digestive glands were performed at regular intervals during the period of heat stress. The SI provided a lower stress environment based on physicochemical parameters such as pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), and alkalinity for the survival of test species, although both sites experienced mortality due to thermal stresses. The parity in protein expressions displayed a uniform mode of adaptive impact to temperature elevations in both field and laboratory exposure. The Hsp70 expression was minimal at lower thermal stress, but increased with a rise in temperature. It is very likely that higher Hsp70 levels are not directly related to survival or adaptation. In contrast, MnSOD levels appeared to be an indicator of adaptive responses vis-a-vis survival of the animals. So, the expression levels of a universal free radical scavenger like MnSOD are recognized as a potential biomarker in a bioindicator species like Bellamya.

Airway lipoxin A4 generation and lipoxin A4 receptor expression are decreased in severe asthma.

PubMed

Planagumà, Anna; Kazani, Shamsah; Marigowda, Gautham; Haworth, Oliver; Mariani, Thomas J; Israel, Elliot; Bleecker, Eugene R; Curran-Everett, Douglas; Erzurum, Serpil C; Calhoun, William J; Castro, Mario; Chung, Kian Fan; Gaston, Benjamin; Jarjour, Nizar N; Busse, William W; Wenzel, Sally E; Levy, Bruce D

2008-09-15

Airway inflammation is common in severe asthma despite antiinflammatory therapy with corticosteroids. Lipoxin A(4) (LXA(4)) is an arachidonic acid-derived mediator that serves as an agonist for resolution of inflammation. Airway levels of LXA(4), as well as the expression of lipoxin biosynthetic genes and receptors, in severe asthma. Samples of bronchoalveolar lavage fluid were obtained from subjects with asthma and levels of LXA(4) and related eicosanoids were measured. Expression of lipoxin biosynthetic genes was determined in whole blood, bronchoalveolar lavage cells, and endobronchial biopsies by quantitative polymerase chain reaction, and leukocyte LXA(4) receptors were monitored by flow cytometry. Individuals with severe asthma had significantly less LXA(4) in bronchoalveolar lavage fluids (11.2 +/- 2.1 pg/ml) than did subjects with nonsevere asthma (150.1 +/- 38.5 pg/ml; P < 0.05). In contrast, levels of cysteinyl leukotrienes were increased in both asthma cohorts compared with healthy individuals. In severe asthma, 15-lipoxygenase-1 mean expression was decreased fivefold in bronchoalveolar lavage cells. In contrast, 15-lipoxgenase-1 was increased threefold in endobronchial biopsies, but expression of both 5-lipoxygenase and 15-lipoxygenase-2 in these samples was decreased. Cyclooxygenase-2 expression was decreased in all anatomic compartments sampled in severe asthma. Moreover, LXA(4) receptor gene and protein expression were significantly decreased in severe asthma peripheral blood granulocytes. Mechanisms underlying pathological airway responses in severe asthma include lipoxin underproduction with decreased expression of lipoxin biosynthetic enzymes and receptors. Together, these results indicate that severe asthma is characterized, in part, by defective lipoxin counterregulatory signaling circuits.

Effect of beta-phenylethylamine on extracellular concentrations of dopamine in the nucleus accumbens and prefrontal cortex.

PubMed

Murata, Mikio; Katagiri, Nobuyuki; Ishida, Kota; Abe, Kenji; Ishikawa, Masago; Utsunomiya, Iku; Hoshi, Keiko; Miyamoto, Ken-ichi; Taguchi, Kyoji

2009-05-07

It is known that psychostimulants stimulate dopamine transmission in the nucleus accumbens. In the present study, we examined the effects of systemically administered beta-phenylethylamine (beta-PEA), a psychomotor-stimulating trace amine, on dopamine concentrations in the nucleus accumbens and prefrontal cortex in freely moving rats, using an in vivo microdialysis technique. Intraperitoneal administration of beta-PEA (12.5 and 25 mg/kg) significantly increased extracellular dopamine levels in the nucleus accumbens shell. The observed increase in the dopamine concentration in nucleus accumbens shell dialysate after intraperitoneal administration of 25 mg/kg beta-PEA was inhibited by pre-treatment with a dopamine uptake inhibitor, GBR12909 (10 mg/kg, i.p.). In contrast, beta-PEA (25 mg/kg, i.p.) did not affect dopamine release in the nucleus accumbens core. Although a high dose of beta-PEA (50 mg/kg) significantly increased dopamine levels in the nucleus accumbens core, the dopamine increasing effect of beta-PEA was more potent in the nucleus accumbens shell. Systemic administration of 12.5 and 25 mg/kg beta-PEA also increased extracellular dopamine levels in the prefrontal cortex of rats. However, systemic 25 mg/kg beta-PEA-induced increases in extracellular dopamine levels were not blocked by GBR12909 within the prefrontal cortex. These results suggest that beta-PEA has a greater effect in the shell than in the core and low-dose beta-PEA stimulates dopamine release in the nucleus accumbens shell through uptake by a dopamine transporter. Similarly, beta-PEA increased extracellular dopamine levels in the prefrontal cortex. Thus, beta-PEA may increase extracellular dopamine concentrations in the mesocorticolimbic pathway.

Increase of EPA-derived hydroxy, epoxy and dihydroxy fatty acid levels in human plasma after a single dose of long-chain omega-3 PUFA.

PubMed

Schuchardt, Jan Philipp; Schneider, Inga; Willenberg, Ina; Yang, Jun; Hammock, Bruce D; Hahn, Andreas; Schebb, Nils Helge

2014-06-01

Several supplementation studies with long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) describe an increase of EPA-derived hydroxy, epoxy and dihydroxy fatty acids in blood, while changes in levels of other LC n-3 and n-6 PUFA-derived oxylipins were minor. In order to investigate the kinetics of changes in oxylipin levels in response to LC n-3 PUFA ingestion, we conducted a single dose treatment study with healthy subjects. In the present kinetic study, we compared patterns of hydroxy, epoxy and dihydroxy fatty acids in plasma of 6 healthy men before and after 6, 8, 24, and 48h of fish oil (1008mg EPA and 672mg DHA) ingestion. Levels of EPA- as well as other LC PUFA-derived hydroxy, epoxy and dihydroxy fatty acids were analyzed in plasma by LC-MS. Additionally, levels of these oxylipins were compared with their parent PUFA levels in plasma phospholipids. All EPA-derived oxylipin levels were significantly increased 6h after LC n-3 PUFA ingestion and gradually drop thereafter reaching the baseline levels about 48h after treatment. The relative increase in EPA plasma phospholipid levels highly correlated with the increase of plasma EPA-derived oxylipin levels at different time points. In contrast, plasma levels of arachidonic acid- and DHA-derived oxylipins as well as parent PUFA levels in plasma phospholipids were hardly changed. Our findings demonstrate that a single dose of LC n-3 PUFAs can rapidly induce a shift in the EPA oxylipin profile of healthy subjects within a few hours. Taking the high biological activity of the EPA-derived epoxy fatty acids into account, even short-term treatment with LC n-3 PUFAs may cause systemic effects, which warrant further investigation. Copyright © 2014 Elsevier Inc. All rights reserved.

Sloths like it hot: ambient temperature modulates food intake in the brown-throated sloth (Bradypus variegatus).

PubMed

Cliffe, Rebecca N; Haupt, Ryan J; Avey-Arroyo, Judy A; Wilson, Rory P

2015-01-01

Sloths are considered to have one of the lowest mass-specific metabolic rates of any mammal and, in tandem with a slow digestive rate, have been theorized to have correspondingly low rates of ingestion. Here, we show in a study conducted over five months, that three captive Bradypus variegatus (Brown-throated sloths) had a remarkably low mean food intake of 17 g kg(-1)day(-1) (SD 4.2). Food consumption was significantly affected by ambient temperature, with increased intake at higher temperatures. We suggest that the known fluctuation of sloth core body temperature with ambient temperature affects the rate at which gut fauna process digesta, allowing for increased rates of fermentation at higher temperatures. Since Bradypus sloths maintain a constantly full stomach, faster rates of fermentation should enhance digestive throughput, increasing the capacity for higher levels of food intake, thereby allowing increased energy acquisition at higher ambient temperatures. This contrasts with other mammals, which tend to show increased levels of food intake in colder conditions, and points to the importance of temperature in regulating all aspects of energy use in sloths.

The relationship between UV-irradiance, photoprotective compounds and DNA damage in two intertidal invertebrates with contrasting mobility characteristics.

PubMed

Cubillos, Victor Mauricio; Burritt, David J; Lamare, Miles D; Peake, Barrie M

2015-08-01

The photoprotective role of mycosporine-like amino acids (MAA) against the generation of DNA cyclobutane pyrimidine dimers (CPD) was studied in the sessile intertidal anemone Actinia tenebrosa and the mobile intertidal gastropod Diloma aethiops through 27months at a mid-latitude New Zealand location. MAA were sequestered by A. tenebrosa and D. aethiops from their diet, although maximum total MAA levels in both species were not correlated with seasonal variation in maximum ambient UV-B levels recorded at the collection site. Temporal changes in total MAA in A. tenebrosa showed a six months lag-time in their concentration regarding to the environmental UV-B levels. This lag period corresponded to an observed increase in CPD production from spring to summer; suggesting that MAA do not completely protect the anemone from UV-B during summer. For D. aethiops, total MAA concentrations did not change significantly during the study, although qualitative changes in MAA were apparent. A month lag-time in MAA concentration in D. aethiops and possibly the physical barrier that the shell confers to the animal, can explain reduced CPD levels in comparative terms with A. tenebrosa. Although MAA are used by invertebrates for photoprotection, contrasting mobility characteristics and the presence of physical adaptations can confer them important protection levels during temporal changes of UV-B at mid-latitude places of the Southern Hemisphere. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of eccentricity on color contrast.

PubMed

Vanston, John E; Crognale, Michael A

2018-04-01

Using near-threshold stimuli, human color sensitivity has been shown to decrease across the visual field, likely due in part to physiological differences between the fovea and periphery. It remains unclear to what extent this holds true for suprathreshold stimuli. The current study used suprathreshold contrast matching to examine how perceived contrast varies with eccentricity along the cardinal axes in a cone-opponent space. Our data show that, despite increasing stimulus size in the periphery, the LM axis stimuli were still perceived as reduced in contrast, whereas the S axis perceived contrast was observed to increase with eccentricity.

Contrast enema as a guide for senna-based laxatives in managing overflow retentive stool incontinence in pediatrics.

PubMed

Radwan, Ahmed Bassiuony; El-Debeiky, Mohammed Soliman; Abdel-Hay, Sameh

2015-08-01

Overflow retentive stool incontinence (ORSI) is secondary to constipation and fecal loading. In our study, the dose and duration of senna-based laxatives (SBL) treatment to achieve full defecatory control will be examined for possible correlation with new parameters measured from the initial contrast enema. Initially, an observational study was conducted prospectively on a group of patient with ORSI to define the optimum dose of SBL to achieve full defecatory control with measurement of six parameters in the initial contrast enema (level of colonic dilatation, recto-anal angle, ratio of maximal diameter of dilated colon to last lumbar spine, ratio of maximum diameter of dilated colon to normal descending colon, immediate and after 24-h post-evacuation residual contrast). The result was analyzed statistically to reach a correlation between the radiological data and prescribed dose. Over 2 and half years, 72 patients were included in the study; their mean age was 6.3 ± 3.33 years. The mean effective starting dose of SBL was 57 ± 18.13 mg/day and the mean effective ending dose was 75 ± 31.68 mg/day. Time lapsed till full defecatory control ranged from 1 to 16 weeks. Statistical correlation revealed that mean effective ending dose of SBL treatment significantly increased with higher levels of colonic dilatation. A weak positive correlation was found for both the mean effective starting and ending doses with the ratio of maximum colonic diameter to last lumbar spine and descending colonic diameters ratio. Senna-based laxatives are effective treatment for overflow retentive stool incontinence and their doses can be adjusted initially depending on the analysis of the radiological data.

Environmental influences on neural systems of relational complexity

PubMed Central

Kalbfleisch, M. Layne; deBettencourt, Megan T.; Kopperman, Rebecca; Banasiak, Meredith; Roberts, Joshua M.; Halavi, Maryam

2013-01-01

Constructivist learning theory contends that we construct knowledge by experience and that environmental context influences learning. To explore this principle, we examined the cognitive process relational complexity (RC), defined as the number of visual dimensions considered during problem solving on a matrix reasoning task and a well-documented measure of mature reasoning capacity. We sought to determine how the visual environment influences RC by examining the influence of color and visual contrast on RC in a neuroimaging task. To specify the contributions of sensory demand and relational integration to reasoning, our participants performed a non-verbal matrix task comprised of color, no-color line, or black-white visual contrast conditions parametrically varied by complexity (relations 0, 1, 2). The use of matrix reasoning is ecologically valid for its psychometric relevance and for its potential to link the processing of psychophysically specific visual properties with various levels of RC during reasoning. The role of these elements is important because matrix tests assess intellectual aptitude based on these seemingly context-less exercises. This experiment is a first step toward examining the psychophysical underpinnings of performance on these types of problems. The importance of this is increased in light of recent evidence that intelligence can be linked to visual discrimination. We submit three main findings. First, color and black-white visual contrast (BWVC) add demand at a basic sensory level, but contributions from color and from BWVC are dissociable in cortex such that color engages a “reasoning heuristic” and BWVC engages a “sensory heuristic.” Second, color supports contextual sense-making by boosting salience resulting in faster problem solving. Lastly, when visual complexity reaches 2-relations, color and visual contrast relinquish salience to other dimensions of problem solving. PMID:24133465

Bone Fractures with Sodium-Glucose Co-transporter-2 Inhibitors: How Real is the Risk?

PubMed

Mannucci, Edoardo; Monami, Matteo

2017-02-01

This article succinctly summarizes the available evidence on the risk of bone fractures with sodium-glucose co-transporter-2 inhibitors. The US Food and Drug Administration has strengthened the warning for canagliflozin related to the increased risk of bone fractures, and added new information about decreased bone mineral density. The agency has also said that it will evaluate the risk of bone fractures with other drugs in the sodium-glucose co-transporter-2 inhibitor class. Increases in parathyroid hormone levels and decreases in 1,25-dihydroxyvitamin D levels have been postulated as possible mechanisms. In contrast, some studies with dapagliflozin have shown no effects on bone health. Because a consensus has not been reached, we believe that an expert opinion on how to interpret the available evidence would be of great benefit for clinicians.

Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster.

PubMed

Reshef, Noam; Walbaum, Natasha; Agam, Nurit; Fait, Aaron

2017-01-01

Vineyards are characterized by their large spatial variability of solar irradiance (SI) and temperature, known to effectively modulate grape metabolism. To explore the role of sunlight in shaping fruit composition and cluster uniformity, we studied the spatial pattern of incoming irradiance, fruit temperature and metabolic profile within individual grape clusters under three levels of sunlight exposure. The experiment was conducted in a vineyard of Cabernet Sauvignon cv. located in the Negev Highlands, Israel, where excess SI and midday temperatures are known to degrade grape quality. Filtering SI lowered the surface temperature of exposed fruits and increased the uniformity of irradiance and temperature in the cluster zone. SI affected the overall levels and patterns of accumulation of sugars, organic acids, amino acids and phenylpropanoids, across the grape cluster. Increased exposure to sunlight was associated with lower accumulation levels of malate, aspartate, and maleate but with higher levels of valine, leucine, and serine, in addition to the stress-related proline and GABA. Flavan-3-ols metabolites showed a negative response to SI, whereas flavonols were highly induced. The overall levels of anthocyanins decreased with increased sunlight exposure; however, a hierarchical cluster analysis revealed that the members of this family were grouped into three distinct accumulation patterns, with malvidin anthocyanins and cyanidin-glucoside showing contrasting trends. The flavonol-glucosides, quercetin and kaempferol, exhibited a logarithmic response to SI, leading to improved cluster uniformity under high-light conditions. Comparing the within-cluster variability of metabolite accumulation highlighted the stability of sugars, flavan-3-ols, and cinnamic acid metabolites to SI, in contrast to the plasticity of flavonols. A correlation-based network analysis revealed that extended exposure to SI modified metabolic coordination, increasing the number of negative correlations between metabolites in both pulp and skin. This integrated study of micrometeorology and metabolomics provided insights into the grape-cluster pattern of accumulation of 70 primary and secondary metabolites as a function of spatial variations in SI. Studying compound-specific responses against an extended gradient of quantified conditions improved our knowledge regarding the modulation of berry metabolism by SI, with the aim of using sunlight regulation to accurately modulate fruit composition in warm and arid/semi-arid regions.

Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster

PubMed Central

Reshef, Noam; Walbaum, Natasha; Agam, Nurit; Fait, Aaron

2017-01-01

Vineyards are characterized by their large spatial variability of solar irradiance (SI) and temperature, known to effectively modulate grape metabolism. To explore the role of sunlight in shaping fruit composition and cluster uniformity, we studied the spatial pattern of incoming irradiance, fruit temperature and metabolic profile within individual grape clusters under three levels of sunlight exposure. The experiment was conducted in a vineyard of Cabernet Sauvignon cv. located in the Negev Highlands, Israel, where excess SI and midday temperatures are known to degrade grape quality. Filtering SI lowered the surface temperature of exposed fruits and increased the uniformity of irradiance and temperature in the cluster zone. SI affected the overall levels and patterns of accumulation of sugars, organic acids, amino acids and phenylpropanoids, across the grape cluster. Increased exposure to sunlight was associated with lower accumulation levels of malate, aspartate, and maleate but with higher levels of valine, leucine, and serine, in addition to the stress-related proline and GABA. Flavan-3-ols metabolites showed a negative response to SI, whereas flavonols were highly induced. The overall levels of anthocyanins decreased with increased sunlight exposure; however, a hierarchical cluster analysis revealed that the members of this family were grouped into three distinct accumulation patterns, with malvidin anthocyanins and cyanidin-glucoside showing contrasting trends. The flavonol-glucosides, quercetin and kaempferol, exhibited a logarithmic response to SI, leading to improved cluster uniformity under high-light conditions. Comparing the within-cluster variability of metabolite accumulation highlighted the stability of sugars, flavan-3-ols, and cinnamic acid metabolites to SI, in contrast to the plasticity of flavonols. A correlation-based network analysis revealed that extended exposure to SI modified metabolic coordination, increasing the number of negative correlations between metabolites in both pulp and skin. This integrated study of micrometeorology and metabolomics provided insights into the grape-cluster pattern of accumulation of 70 primary and secondary metabolites as a function of spatial variations in SI. Studying compound-specific responses against an extended gradient of quantified conditions improved our knowledge regarding the modulation of berry metabolism by SI, with the aim of using sunlight regulation to accurately modulate fruit composition in warm and arid/semi-arid regions. PMID:28203242

Effect of K+ATP channel and adenosine receptor blockade during rest and exercise in congestive heart failure.

PubMed

Traverse, Jay H; Chen, YingJie; Hou, MingXiao; Li, Yunfang; Bache, Robert J

2007-06-08

K(+)(ATP) channels are important metabolic regulators of coronary blood flow (CBF) that are activated in the setting of reduced levels of ATP or perfusion pressure. In the normal heart, blockade of K(+)(ATP) channels results in a approximately 20% reduction in resting CBF but does not impair the increase in CBF that occurs during exercise. In contrast, adenosine receptor blockade fails to alter CBF or myocardial oxygen consumption (MVO(2)) in the normal heart but contributes to the increase in CBF during exercise when vascular K(+)(ATP) channels are blocked. Congestive heart failure (CHF) is associated with a decrease in CBF that is matched to a decrease in MVO(2) suggesting downregulation of myocardial energy utilization. Because myocardial ATP levels and coronary perfusion pressure are reduced in CHF, this study was undertaken to examine the role of K(+)(ATP) channels and adenosine in dogs with pacing-induced CHF. Myocardial blood flow (MBF) and MVO(2) were measured during rest and treadmill exercise before and after K(+)(ATP) channel blockade with glibenclamide (50 microg/kg/min ic) or adenosine receptor blockade with 8-phenyltheophylline (8-PT; 5 mg/kg iv). Inhibition of K(+)(ATP) channels resulted in a decrease in CBF and MVO(2) at rest and during exercise without a change in the relationship between CBF and MVO(2). In contrast, adenosine receptor blockade caused a significant increase in CBF that occurred secondary to an increase of MVO(2). These findings demonstrate that coronary K(+)(ATP) channel activity contribute to the regulation of resting MBF in CHF, and that endogenous adenosine may act to inhibit MVO(2) in the failing heart.

Effect of variable tinted spectacle lenses on visual performance in control subjects.

PubMed

Lee, Jason E; Stein, Jonathan J; Prevor, Meredith B; Seiple, William H; Holopigian, Karen; Greenstein, Vivienne C; Stenson, Susan M

2002-04-01

To evaluate quantitatively the effects of tinted spectacle lenses on visual performance in individuals without visual pathology. Twenty-five subjects were assessed by measuring contrast sensitivity with and without glare. Gray, brown, yellow, green, purple, and blue lens tints were evaluated. Measurements were repeated with each lens tint and with a clear lens, and the order was counterbalanced within and between subjects. Glare was induced with a modified brightness acuity tester. All subjects demonstrated an increase in contrast thresholds under glare conditions for all lens tints. However, purple and blue lens tints resulted in the least amount of contrast threshold increase; the yellow lens tint resulted in the largest contrast threshold increase. Purple and blue lens tints may improve contrast sensitivity in control subjects under glare conditions.

Contrast of slightly complex patterns: computing the perceived contrast of Gabor patches

NASA Astrophysics Data System (ADS)

Peli, Eli

1996-04-01

The local contrast in an image may be approximated by the contrast of a Gabor patch of varying phase and bandwidth. In a search for a metric for such local contrast, perceived (apparent) contrast, as indicated by matching of such patterns, were compared here to the physical contrast calculated by a number of methods. The 2 cycles/deg 1-octave Gabor patch stimuli of different phases were presented side by side separated by 4 degrees. During each session the subjects (n equals 5) were adapted to the average luminance, and four different contrast levels (0.1, 0.3, 0.6, and 0.8) were randomly interleaved. The task was repeated at four mean luminance levels between 0.75 and 37.5 cd/m2. The subject's task was to indicate which of the two patterns was lower in contrast. Equal apparent contrast was determined by fitting a psychometric function to the data from 40 to 70 presentations. There was no effect of mean luminance on the subjects settings. The matching results rejected the hypothesis that either the Michelson formula or the King-Smith & Kulikowski contrast (CKK equals (Lmax-Laverage)/Laverage) was used by the subjects to set the match. The use of the Nominal contrast (the Michelson contrast of the underlying sinusoid) as an estimate of apparent contrast could not be rejected. In a second experiment the apparent contrast of a 1-octave Gabor patch was matched to the apparent contrast of a 2-octave Gabor patch (of Nominal contrast of 0.1, 0.3, 0.6, 0.8) using the method of adjustment. The result of this experiment rejected the prediction of the Nominal contrast definition. The local band limited contrast measure (Peli, 1990), when used with the modifications suggested by Lubin (1995), as an estimate of apparent contrast could not be rejected by the results of either experiment. These results suggest that a computational contrast measure based on multi scale bandpass filtering is a better estimate of apparent perceived contrast than any of the other measures tested.

Contrast-enhanced ultrasound (CEUS) in blunt abdominal trauma

PubMed Central

Piccolo, Claudia Lucia; Galluzzo, Michele; Ianniello, Stefania; Sessa, Barbara; Trinci, Margherita

2016-01-01

Baseline ultrasound is essential in the early assessment of patients with a huge haemoperitoneum undergoing an immediate abdominal surgery; nevertheless, even with a highly experienced operator, it is not sufficient to exclude parenchymal injuries. More recently, a new ultrasound technique using second generation contrast agents, named contrast-enhanced ultrasound (CEUS) has been developed. This technique allows all the vascular phase to be performed in real time, increasing ultrasound capability to detect parenchymal injuries, enhancing some qualitative findings, such as lesion extension, margins and its relationship with capsule and vessels. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients with low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. Several studies demonstrated its ability to detect lesions occurring in the liver, spleen, pancreas and kidneys and also to recognize active bleeding as hyperechoic bands appearing as round or oval spots of variable size. Its role seems to be really relevant in paediatric patients, thus avoiding a routine exposure to ionizing radiation. Nevertheless, CEUS is strongly operator dependent, and it has some limitations, such as the cost of contrast media, lack of panoramicity, the difficulty to explore some deep regions and the poor ability to detect injuries to the urinary tract. On the other hand, it is timesaving, and it has several advantages, such as its portability, the safety of contrast agent, the lack to ionizing radiation exposure and therefore its repeatability, which allows follow-up of those traumas managed conservatively, especially in cases of fertile females and paediatric patients. PMID:26607647

Relationship of postprandial nonesterified fatty acids, adipokines, and insulin across gender in human immunodeficiency virus-positive patients undergoing highly active antiretroviral therapy.

PubMed

Lu, Guijing; Thomas-Geevarghese, Asha; Anuurad, Erdembileg; Raghavan, Subhashree; Minolfo, Robert; Ormsby, Bernard; Karmally, Wahida; El-Sadr, Wafaa M; Albu, Jeanine; Berglund, Lars

2009-06-01

Metabolic derangements are common in human immunodeficiency virus (HIV)-positive subjects undergoing antiretroviral therapy, but little is known about postprandial conditions. We investigated the relationship between leptin, adiponectin, nonesterified fatty acids (NEFA), and insulin in response to a day-long meal pattern and evaluated gender differences in HIV-positive men (n = 12) and women (n = 13) undergoing highly active antiretroviral therapy (HAART). For both men and women, a significant decrease in postprandial NEFA levels was observed following breakfast (0.53 vs. 0.22 mmol/L, P < 0.001, baseline and at 3 hours, respectively), whereas day-long postprandial leptin and adiponectin levels showed small nonsignificant oscillations. In contrast to NEFA and adiponectin, postprandial leptin levels were significantly higher among women compared to men (P < 0.05). Postprandial NEFA levels correlated positively with fasting insulin levels (r(2) = 0.25, P = 0.016), and the postbreakfast decrease in NEFA levels correlated significantly with the postbreakfast increase in insulin levels (r(2) = 0.17, P = 0.038). No significant association between postprandial adipokines and insulin was observed. In HAART-treated, HIV-infected men and women, levels of NEFA, but not adipokines, showed significant postprandial variation. Furthermore, food intake resulted in significant NEFA suppression in proportion to the food-stimulated insulin increase.

Drilling and operational sounds from an oil production island in the ice-covered Beaufort sea.

PubMed

Blackwell, Susanna B; Greene, Charles R; Richardson, W John

2004-11-01

Recordings of sounds underwater and in air, and of iceborne vibrations, were obtained at Northstar Island, an artificial gravel island in the Beaufort Sea near Prudhoe Bay (Alaska). The aim was to document the levels, characteristics, and range dependence of sounds and vibrations produced by drilling and oil production during the winter, when the island was surrounded by shore-fast ice. Drilling produced the highest underwater broadband (10-10,000 Hz) levels (maximum= 124 dB re: 1 microPa at 1 km), and mainly affected 700-1400 Hz frequencies. In contrast, drilling did not increase broadband levels in air or ice relative to levels during other island activities. Production did not increase broadband levels for any of the sensors. In all media, broadband levels decreased by approximately 20 dB/tenfold change in distance. Background levels underwater were reached by 9.4 km during drilling and 3-4 km without. In the air and ice, background levels were reached 5-10 km and 2-10 km from Northstar, respectively, depending on the wind but irrespective of drilling. A comparison of the recorded sounds with harbor and ringed seal audiograms showed that Northstar sounds were probably audible to seals, at least intermittently, out to approximately 1.5 km in water and approximately 5 km in air.

Corticosterone and dehydroepiandrosterone in songbird plasma and brain: effects of season and acute stress

PubMed Central

Newman, Amy E. M.; Soma, Kiran K.

2010-01-01

Prolonged increases in plasma glucocorticoids can exacerbate neurodegeneration. In rats, these neurodegenerative effects can be reduced by dehydroepiandrosterone (DHEA), an androgen precursor with anti-glucocorticoid actions. In song sparrows, season and acute restraint stress affect circulating levels of corticosterone and DHEA, and the effects of stress differ in plasma collected from the brachial and jugular veins. Jugular plasma is an indirect index of the neural steroidal milieu. Here, we directly measured corticosterone and DHEA in several brain regions and jugular plasma, and examined the effects of season and acute restraint stress (30 min) (n = 571 samples). Corticosterone levels were up to 10× lower in brain than in jugular plasma. In contrast, DHEA levels were up to 5× higher in brain than in jugular plasma and were highest in the hippocampus. Corticosterone and DHEA concentrations were strongly seasonally regulated in plasma but, surprisingly, not seasonally regulated in brain. Acute stress increased corticosterone levels in plasma and brain, except during the molt, when stress unexpectedly decreased corticosterone levels in the hippocampus. Acute stress increased DHEA levels in plasma during the molt but had no effects on DHEA levels in brain. This is the first study to measure (i) corticosterone or DHEA levels in the brain of adult songbirds and (ii) seasonal changes in corticosterone or DHEA levels in the brain of any species. These results highlight several critical differences between systemic and local steroid concentrations and the difficulty of using circulating steroid levels to infer local steroid levels within the brain. PMID:19473242

A Forest Tent Caterpillar Outbreak Increased Resource Levels and Seedling Growth in a Northern Hardwood Forest.

PubMed

Rozendaal, Danaë M A; Kobe, Richard K

2016-01-01

In closed-canopy forests, gap formation and closure are thought to be major drivers of forest dynamics. Crown defoliation by insects, however, may also influence understory resource levels and thus forest dynamics. We evaluate the effect of a forest tent caterpillar outbreak on understory light availability, soil nutrient levels and tree seedling height growth in six sites with contrasting levels of canopy defoliation in a hardwood forest in northern lower Michigan. We compared resource levels and seedling growth of six hardwood species before, during and in the three years after the outbreak (2008-2012). Canopy openness increased strongly during the forest tent caterpillar outbreak in the four moderately and severely defoliated sites, but not in lightly defoliated sites. Total inorganic soil nitrogen concentrations increased in response to the outbreak in moderately and severely defoliated sites. The increase in total inorganic soil nitrogen was driven by a strong increase in soil nitrate, and tended to become stronger with increasing site defoliation. Seedling height growth increased for all species in the moderately and severely defoliated sites, but not in lightly defoliated sites, either during the outbreak year or in the year after the outbreak. Growth increases did not become stronger with increasing site defoliation, but were strongest in a moderately defoliated site with high soil nutrient levels. Growth increases tended to be strongest for the shade intolerant species Fraxinus americana and Prunus serotina, and the shade tolerant species Ostrya virginiana. The strong growth response of F. americana and P. serotina suggests that recurring forest tent caterpillar outbreaks may facilitate the persistence of shade intolerant species in the understory in the absence of canopy gaps. Overall, our results suggest that recurrent canopy defoliation resulting from cyclical forest insect outbreaks may be an additional driver of dynamics in temperate closed-canopy forests.

A Forest Tent Caterpillar Outbreak Increased Resource Levels and Seedling Growth in a Northern Hardwood Forest

PubMed Central

Rozendaal, Danaë M. A.; Kobe, Richard K.

2016-01-01

In closed-canopy forests, gap formation and closure are thought to be major drivers of forest dynamics. Crown defoliation by insects, however, may also influence understory resource levels and thus forest dynamics. We evaluate the effect of a forest tent caterpillar outbreak on understory light availability, soil nutrient levels and tree seedling height growth in six sites with contrasting levels of canopy defoliation in a hardwood forest in northern lower Michigan. We compared resource levels and seedling growth of six hardwood species before, during and in the three years after the outbreak (2008–2012). Canopy openness increased strongly during the forest tent caterpillar outbreak in the four moderately and severely defoliated sites, but not in lightly defoliated sites. Total inorganic soil nitrogen concentrations increased in response to the outbreak in moderately and severely defoliated sites. The increase in total inorganic soil nitrogen was driven by a strong increase in soil nitrate, and tended to become stronger with increasing site defoliation. Seedling height growth increased for all species in the moderately and severely defoliated sites, but not in lightly defoliated sites, either during the outbreak year or in the year after the outbreak. Growth increases did not become stronger with increasing site defoliation, but were strongest in a moderately defoliated site with high soil nutrient levels. Growth increases tended to be strongest for the shade intolerant species Fraxinus americana and Prunus serotina, and the shade tolerant species Ostrya virginiana. The strong growth response of F. americana and P. serotina suggests that recurring forest tent caterpillar outbreaks may facilitate the persistence of shade intolerant species in the understory in the absence of canopy gaps. Overall, our results suggest that recurrent canopy defoliation resulting from cyclical forest insect outbreaks may be an additional driver of dynamics in temperate closed-canopy forests. PMID:27870897

Noisy Spiking in Visual Area V2 of Amblyopic Monkeys.

PubMed

Wang, Ye; Zhang, Bin; Tao, Xiaofeng; Wensveen, Janice M; Smith, Earl L; Chino, Yuzo M

2017-01-25

Interocular decorrelation of input signals in developing visual cortex can cause impaired binocular vision and amblyopia. Although increased intrinsic noise is thought to be responsible for a range of perceptual deficits in amblyopic humans, the neural basis for the elevated perceptual noise in amblyopic primates is not known. Here, we tested the idea that perceptual noise is linked to the neuronal spiking noise (variability) resulting from developmental alterations in cortical circuitry. To assess spiking noise, we analyzed the contrast-dependent dynamics of spike counts and spiking irregularity by calculating the square of the coefficient of variation in interspike intervals (CV 2 ) and the trial-to-trial fluctuations in spiking, or mean matched Fano factor (m-FF) in visual area V2 of monkeys reared with chronic monocular defocus. In amblyopic neurons, the contrast versus response functions and the spike count dynamics exhibited significant deviations from comparable data for normal monkeys. The CV 2 was pronounced in amblyopic neurons for high-contrast stimuli and the m-FF was abnormally high in amblyopic neurons for low-contrast gratings. The spike count, CV 2 , and m-FF of spontaneous activity were also elevated in amblyopic neurons. These contrast-dependent spiking irregularities were correlated with the level of binocular suppression in these V2 neurons and with the severity of perceptual loss for individual monkeys. Our results suggest that the developmental alterations in normalization mechanisms resulting from early binocular suppression can explain much of these contrast-dependent spiking abnormalities in V2 neurons and the perceptual performance of our amblyopic monkeys. Amblyopia is a common developmental vision disorder in humans. Despite the extensive animal studies on how amblyopia emerges, we know surprisingly little about the neural basis of amblyopia in humans and nonhuman primates. Although the vision of amblyopic humans is often described as being noisy by perceptual and modeling studies, the exact nature or origin of this elevated perceptual noise is not known. We show that elevated and noisy spontaneous activity and contrast-dependent noisy spiking (spiking irregularity and trial-to-trial fluctuations in spiking) in neurons of visual area V2 could limit the visual performance of amblyopic primates. Moreover, we discovered that the noisy spiking is linked to a high level of binocular suppression in visual cortex during development. Copyright © 2017 the authors 0270-6474/17/370922-14$15.00/0.

MRI and CT contrast media extravasation

PubMed Central

Heshmatzadeh Behzadi, Ashkan; Farooq, Zerwa; Newhouse, Jeffery H.; Prince, Martin R.

2018-01-01

Abstract Background: This systematic review combines data from multiple papers on contrast media extravasation to identify factors contributing to increased extravasation risk. Methods: Data were extracted from 17 papers reporting 2191 extravasations in 1,104,872 patients (0.2%) undergoing computed tomography (CT) or magnetic resonance imaging (MRI). Results: Extravasation rates were 0.045% for gadolinium-based contrast agents (GBCA) and nearly 6-fold higher, 0.26% for iodinated contrast agents. Factors associated with increased contrast media extravasations included: older age, female gender, using an existing intravenous (IV) instead of placing a new IV in radiology, in-patient status, use of automated power injection, high injection rates, catheter location, and failing to warm up the more viscous contrast media to body temperature. Conclusion: Contrast media extravasation is infrequent but nearly 6 times less frequent with GBCA for MRI compared with iodinated contrast used in CT. PMID:29489663