An association between serum γ-glutamyltransferase and proteinuria in drinkers and non-drinkers: a Japanese nationwide cross-sectional survey.

PubMed

Ishigami, Toshihiro; Yamamoto, Ryohei; Nagasawa, Yasuyuki; Isaka, Yoshitaka; Rakugi, Hiromi; Iseki, Kunitoshi; Yamagata, Kunihiro; Tsuruya, Kazuhiko; Yoshida, Hideaki; Fujimoto, Shouichi; Asahi, Koichi; Kurahashi, Issei; Ohashi, Yasuo; Moriyama, Toshiki; Watanabe, Tsuyoshi

2014-12-01

The association between alcohol consumption and chronic kidney disease (CKD), characterized by reduced glomerular filtration rate and proteinuria, is controversial. Recent studies suggest that serum γ-glutamyltransferase (GGT) level, a conventional marker of excessive alcohol consumption, predicts the CKD incidence. Little information is available on the difference in the clinical impact of alcohol consumption and GGT on proteinuria. The present cross-sectional survey included 332,296 Japanese people aged ≥40 years in 2008. To examine the associations of GGT and alcohol consumption with proteinuria, 134,600 men and 197,696 women were classified into 20 categories based on GGT quartiles and alcohol consumption categories, and their prevalence rate ratios (PRR) of proteinuria defined as ≥1+ of dipstick urinary protein were calculated after adjusting for clinically relevant factors. Prevalence of proteinuria was 7.5 and 3.7 % in men and women, respectively. In both gender an association between alcohol consumption and proteinuria was in a J-shaped fashion with the lowest PRR of mild drinkers with ≤19 g/day of ethanol consumption, whereas an association between serum GGT level and proteinuria was linear. Compared with rare drinkers in the lowest GGT quartile, the subjects in higher GGT quartiles had a higher probability of proteinuria, irrespective of alcohol consumption. An optimal cutoff level of serum GGT was 43.6 and 23.2 IU/L in men and women, respectively. The subjects with higher serum GGT level had a higher probability of proteinuria, regardless of alcohol consumption, suggesting that GGT has a clinically greater impact on CKD than alcohol consumption.

Variation in the γ-glutamyltransferase 1 gene and risk of chronic pancreatitis.

PubMed

Brand, Harrison; Diergaarde, Brenda; O'Connell, Michael R; Whitcomb, David C; Brand, Randall E

2013-07-01

Individuals with chronic pancreatitis are at increased risk for pancreatic cancer. We hypothesized that genetic variation in the γ-glutamyltransferase 1 (GGT1) gene, which was recently reported associated with pancreatic cancer risk in a genome-wide association study, is also associated with risk of chronic pancreatitis. Associations between common polymorphisms in GGT1 and chronic pancreatitis were evaluated using data and samples from the North American Pancreatitis Study 2. Patients (n = 496) and control subjects (n = 465) were genotyped for 4 single-nucleotide polymorphisms: rs4820599, rs2017869, rs8135987, and rs5751901. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) for chronic pancreatitis risk were calculated using multiple logistic regression models. Interactions with cigarette smoking and alcohol use were explored. Single-nucleotide polymorphisms rs8135987 and rs4820599 were both statistically significantly associated with risk of chronic pancreatitis; compared with common allele homozygotes, individuals with at least 1 minor allele were at increased risk (rs8135987: OR, 1.36; 95% CI, 1.03-1.80 [P(trend) = 0.01]; rs4820599: OR, 1.39; 95% CI, 1.04-1.84 [P(trend) = 0.0]; adjusted for age, sex, race, smoking status, and alcohol use). No significant interactions with cigarette smoking and alcohol use were observed. Our results suggest that common variation in the GGT1 gene may also affect risk of chronic pancreatitis.

Gamma-glutamyltransferase and disability pension: a cohort study of construction workers in Germany.

PubMed

Claessen, Heiner; Brenner, Hermann; Drath, Christoph; Arndt, Volker

2010-02-01

Given the accumulating evidence that gamma-glutamyltransferase (gamma-GT) is not merely a sensitive marker for liver and bile disorders but also a risk marker for a multiplicity of other chronic diseases, gamma-GT may represent a promising risk indicator for occupational disability, which has emerged as an important public health problem. The association between gamma-GT and disability pension was examined in a cohort of 16,520 male construction workers in Württemberg, Germany, who participated in routine occupational health examinations from 1986 to 1992 and who were followed until 2005. Using the Cox proportional hazards model, hazard ratios were calculated with gamma-GT concentrations in the lowest quartile (1 to 24 U/L) as reference category after adjustment for age and further adjustment for potential confounding factors such as nationality, type of occupation, smoking, alcohol consumption, cholesterol, and body mass index (BMI). Overall, a monotonically increasing association of gamma-GT with all-cause disability pension (total number: n = 2,998 cases) was observed, with the steepest increase at lower levels of gamma-GT. Particularly strong associations were observed for participants in the highest quartile (>67 U/L) and disability pension due to musculoskeletal disorders, diseases of the digestive system, and cardiovascular as well as mental diseases (age-adjusted hazard ratios with 95% confidence intervals: 1.53, 1.27-1.85; 9.68, 3.10-30.21; 1.76, 1.28-2.42; and 1.83, 1.23-2.72, respectively). gamma-GT is a strong risk indicator of all-cause occupational disability even at levels of gamma-GT in the "normal range" and is in particular associated with disability pension due to diseases of the digestive system, musculoskeletal disorders, cardiovascular, and mental diseases.

Alcohol, metabolic risk and elevated serum gamma-glutamyl transferase (GGT) in Indigenous Australians.

PubMed

Haren, Matthew T; Li, Ming; Petkov, John; McDermott, Robyn A

2010-08-03

The interaction between overweight/obesity and alcohol intake on liver enzyme concentrations have been demonstrated. No studies have yet examined the interaction between metabolic syndrome or multiple metabolic risk factors and alcohol intake on liver enzymes. The aim of this study was to examine if alcohol consumption modifies the effect of metabolic risk on elevated serum GGT in Indigenous Australians. Data were from N = 2609 Indigenous Australians who participated in a health screening program in rural far north Queensland in 1999-2000 (44.5% response rate). The individual and interactive effects of metabolic risk and alcohol drinking on elevated serum GGT concentrations (>or=50 U/L) were analyzed using logistic regression. Overall, 26% of the population had GGT>or=50 U/L. Elevated GGT was associated with alcohol drinking (moderate drinking: OR 2.3 [95%CI 1.6 - 3.2]; risky drinking: OR 6.0 [4.4 - 8.2]), and with abdominal obesity (OR 3.7 [2.5 - 5.6]), adverse metabolic risk cluster profile (OR 3.4 [2.6 - 4.3]) and metabolic syndrome (OR 2.7 [2.1 - 3.5]) after adjustment for age, sex, ethnicity, smoking, physical activity and BMI. The associations of obesity and metabolic syndrome with elevated GGT were similar across alcohol drinking strata, but the association of an adverse metabolic risk cluster profile with elevated GGT was larger in risky drinkers (OR 4.9 [3.7 - 6.7]) than in moderate drinkers (OR 2.8 [1.6 - 4.9]) and abstainers (OR 1.6 [0.9 - 2.8]). In this Indigenous population, an adverse metabolic profile conferred three times the risk of elevated GGT in risky drinkers compared with abstainers, independent of sex and ethnicity. Community interventions need to target both determinants of the population's metabolic status and alcohol consumption to reduce the risk of elevated GGT.

Association of serum gamma-glutamyltransferase and alanine aminotransferase activities with risk of type 2 diabetes mellitus independent of fatty liver.

PubMed

Kim, Chul-Hee; Park, Joong-Yeol; Lee, Ki-Up; Kim, Jin-Ho; Kim, Hong-Kyu

2009-01-01

Although elevated serum concentrations of gamma-glutamyltrans- ferase (GGT) or alanine aminotransferase (ALT) have been associated with type 2 diabetes mellitus, it is unclear whether each is an independent predictor of type 2 diabetes or merely a surrogate marker for fatty liver or hepatic injury. We assessed clinical and laboratory findings in 3556 non-diabetic subjects (2217 men, 1339 women; age, 45.7 +/- 8.1 (range 20-79) years) without fatty liver or clinically significant hepatic dysfunction who underwent voluntary medical check-ups at a 5-year interval. The odds ratio of developing type 2 diabetes increased significantly with increasing GGT and ALT levels at baseline. In multiple logistic regression models adjusted for age, sex, alcohol consumption, smoking, body mass index (BMI), triglycerides, high-density lipoprotein (HDL)-cholesterol, fasting glucose, and ALT, the highest quartile of GGT remained significantly associated with type 2 diabetes. Compared with the first GGT quartile, the odds ratios of the second, third, and fourth GGT quartiles were 0.64 (95% CI, 0.25-1.65), 1.12 (0.45-2.78), and 3.07 (1.21-7.76), respectively. The adjusted odds ratios for the second, third, and fourth ALT quartiles in the same logistic regression model were 2.40 (0.83-6.94), 2.85 (1.03-7.90), and 4.31 (1.56-11.88), respectively. The risk of type 2 diabetes was additive with respect to GGT and ALT quartiles. Increased serum GGT and ALT levels are independent, additive risk factors for the development of type 2 diabetes mellitus in subjects without fatty liver or hepatic dysfunction. Copyright 2009 John Wiley & Sons, Ltd.

Is gamma-glutamyl transpeptidase a biomarker for oxidative stress in periodontitis?

PubMed Central

Sreeram, Meenakshi; Suryakar, Adinath Narayan; Dani, Nitin Hemchandra

2015-01-01

Context: Periodontal disease and oxidative stress (OS) are part of a vicious cycle with each causing a deleterious effect on the other causing changes in the levels of antioxidants, and enzymes of antioxidant defense. Biomarkers and methods used for measuring OS are very expensive. Aims: To see how gamma-glutamyltransferase (GGT) fares, as a biomarker for OS in periodontits along with other routinely used biomarkers. Design: A cross-sectional study involving 300 people of which 150 were cases and 150 were controls. Setting: Candidates enrolled were patients visiting the OPD of MGV's Dental College and Hospital, Nasik, India between January 2011 and December 2012. Materials and Methods: Serum samples of patients with periodontitis, and controls were analyzed for malondialdehyde, superoxide dismutase (SOD), glutathione peroxidase (GPx), uric acid, and GGT. Statistical Analysis Used: Analysis was performed using Student's t test. P <0.05 were considered to be significant. Results: Malondialdehyde values were found to be significantly higher cases, while SOD, GPx and uric acid levels were found to be lower than controls. GGT levels were significantly higher in cases as compared to controls. Conclusions: GGT may be used as a cheap, quick, easy and precise marker for measuring OS. PMID:26015663

Alcohol, metabolic risk and elevated serum gamma-glutamyl transferase (GGT) in Indigenous Australians

PubMed Central

2010-01-01

Background The interaction between overweight/obesity and alcohol intake on liver enzyme concentrations have been demonstrated. No studies have yet examined the interaction between metabolic syndrome or multiple metabolic risk factors and alcohol intake on liver enzymes. The aim of this study was to examine if alcohol consumption modifies the effect of metabolic risk on elevated serum GGT in Indigenous Australians. Methods Data were from N = 2609 Indigenous Australians who participated in a health screening program in rural far north Queensland in 1999-2000 (44.5% response rate). The individual and interactive effects of metabolic risk and alcohol drinking on elevated serum GGT concentrations (≥50 U/L) were analyzed using logistic regression. Results Overall, 26% of the population had GGT≥50 U/L. Elevated GGT was associated with alcohol drinking (moderate drinking: OR 2.3 [95%CI 1.6 - 3.2]; risky drinking: OR 6.0 [4.4 - 8.2]), and with abdominal obesity (OR 3.7 [2.5 - 5.6]), adverse metabolic risk cluster profile (OR 3.4 [2.6 - 4.3]) and metabolic syndrome (OR 2.7 [2.1 - 3.5]) after adjustment for age, sex, ethnicity, smoking, physical activity and BMI. The associations of obesity and metabolic syndrome with elevated GGT were similar across alcohol drinking strata, but the association of an adverse metabolic risk cluster profile with elevated GGT was larger in risky drinkers (OR 4.9 [3.7 - 6.7]) than in moderate drinkers (OR 2.8 [1.6 - 4.9]) and abstainers (OR 1.6 [0.9 - 2.8]). Conclusions In this Indigenous population, an adverse metabolic profile conferred three times the risk of elevated GGT in risky drinkers compared with abstainers, independent of sex and ethnicity. Community interventions need to target both determinants of the population's metabolic status and alcohol consumption to reduce the risk of elevated GGT. PMID:20682033

"Phylogenetic and evolutionary analysis of functional divergence among Gamma glutamyl transpeptidase (GGT) subfamilies".

PubMed

Verma, Ved Vrat; Gupta, Rani; Goel, Manisha

2015-09-14

γ-glutamyltranspeptidase (GGT) is a bi-substrate enzyme conserved in all three domains of life. It catalyzes the cleavage and transfer of γ-glutamyl moiety of glutathione to either water (hydrolysis) or substrates like peptides (transpeptidation). GGTs exhibit great variability in their enzyme kinetics although the mechanism of catalysis is conserved. Recently, GGT has been shown to be a virulence factor in microbes like Helicobacter pylori and Bacillus anthracis. In mammalian cells also, GGT inhibition prior to chemotherapy has been shown to sensitize tumors to the therapy. Therefore, lately both bacterial and eukaryotic GGTs have emerged as potential drug targets, but the efforts directed towards finding suitable inhibitors have not yielded any significant results yet. We propose that delineating the residues responsible for the functional diversity associated with these proteins could help in design of species/clade specific inhibitors. In the present study, we have carried out phylogenetic analysis on a set of 47 GGT-like proteins to address the functional diversity. These proteins segregate into various subfamilies, forming separate clades on the tree. Sequence conservation and motif prediction studies show that even though most of the highly conserved residues have been characterized biochemically in previous studies, a significant number of novel putative sites and motifs are discovered that vary in a clade specific manner. Many of the putative sites predicted during the functional divergence type I and type II analysis, lie close to the known catalytic residues and line the walls of the substrate binding cavity, reinforcing their role in modulating the substrate specificity, catalytic rates and stability of this protein. The study offers interesting insights into the evolution of GGT-like proteins in pathogenic vs. non-pathogenic bacteria, archaea and eukaryotes. Our analysis delineates residues that are highly specific to each GGT subfamily. We propose

Effects of the Dietary Detoxification Program on Serum γ-glutamyltransferase, Anthropometric Data and Metabolic Biomarkers in Adults.

PubMed

Kim, Ju Ah; Kim, Jin Young; Kang, Seung Wan

2016-09-01

Persistent Organic Pollutants (POPs) are well-known environmental contaminants which are associated with chronic diseases. As foods are the major sources of human exposure to toxic pollutants, we developed an integrated dietary and education program to eliminate the chemical toxin throughout the human body. The present study evaluated effects of the dietary detoxification program on serum γ -glutamyltransferase (GGT), anthropometric data and metabolic biomarkers in adults. Single-armed, pre-post study was conducted from June 2013 to June 2015 at a health examination center and a public health center in Seoul, Korea. Sixty eight subjects (mean age of 52.4 years) were recruited. Subjects participated 20 hours' dietary education sessions. On-line coaching with SNS was performed to enhance participants' proper protocol compliance. Physical and laboratory examinations were assessed at week 0 and 3. Changes of the serum GGT were correlated with reductions of the body fat percentage (r = .379, p = .001), body fat mass (r = .435, p = .000) and fasting blood glucose (r = .423, p = .000). Serum GGT, weight, body fat percentage, body fat mass, waist circumference, LDL-cholesterol, HDL-cholesterol, triglyceride, total cholesterol, and blood pressure of all participants were reduced with statistical significance in 3 weeks. In metabolic syndrome group, total cholesterol (p = .049), fasting blood glucose (p = .002), and systolic blood pressure (p = .001) were significantly reduced comparison to non-metabolic syndrome group. This dietary detoxification program might decrease serum GGT which indicated the overall toxic burden in the body. Anthropometric data and metabolic biomarkers were improved. The integrated dietary and education detoxification program seemed to be a protective intervention for elimination of toxicants from the body.

Gamma glutamyl transferase is an independent determinant for the association of insulin resistance with nonalcoholic fatty liver disease in Bangladeshi adults: Association of GGT and HOMA-IR with NAFLD.

PubMed

Hossain, Israt Ara; Rahman Shah, Md Mijanur; Rahman, Mohammad Khalilur; Ali, Liaquat

2016-01-01

Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver-related morbidity and is frequently associated with insulin resistance (HOMA-IR) syndrome. Recently serum gamma glutamyl transferase (GGT) has been considered as surrogate marker of NAFLD leading to oxidative stress and hepatocellular damage. In the present study we examined the association of serum GGT and HOMA-IR with NAFLD in Bangladeshi adult subjects. Under a cross-sectional analytical design a total of 110 subjects were recruited who came for their routine health check up in the BIHS Hospital, Darussalam, Dhaka, Bangladesh. After whole abdomen ultrasonography, 62 were diagnosed as non-NAFLD and 48 were NAFLD subjects. Serum glucose was measured by glucose-oxidase method, lipid profile and liver enzymes by enzymatic colorimetric method, glycosylated hemoglobin (HbA1c) was measured by high performance liquid chromatography (HPLC), serum insulin were measured by enzyme-linked immunosorbent assay. HOMA-IR was calculated by homeostasis model assessment (HOMA). NAFLD subjects had significantly higher levels of GGT and HOMA-IR as compared to their non-NAFLD counterparts. Multiple linear regression analysis showed a significant positive association of HOMA-IR with GGT after adjusting the effects of waist circumference (WC) and HbA1c. In binary logistic regression analysis, HOMA-IR and GGT were found to be significant determinants of NAFLD after adjusting the effects of WC and HbA1c. These results suggest that elevated levels of GGT and insulin resistance are more likely to develop NAFLD and thus support a role of these determinants in the pathogenesis of NAFLD in Bangladeshi adult subjects. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

γ-Glutamyltransferase Fractions in Obese Subjects with Type 2 Diabetes: Relation to Insulin Sensitivity and Effects of Bariatric Surgery.

PubMed

Franzini, Maria; Musetti, Veronica; Guarino, Daniela; Caponi, Laura; Paolicchi, Aldo; Emdin, Michele; Ferrannini, Ele; Nannipieri, Monica

2018-05-01

Gamma-glutamyltranspeptidase (GGT) levels are an independent risk marker for the development of type 2 diabetes (T2DM). We investigated the relationship between the newly identified serum GGT fractions and glucose metabolism in obese subjects before and after bariatric surgery. Twenty-nine T2DM subjects, wait-listed for Roux-en-Y gastric bypass (RYGB; n = 21) or laparoscopic sleeve gastrectomy (LSG; n = 8), received a 5-h mixed meal test before (T0), 15 days (T15), and 1 year after surgery (T365). Insulin sensitivity was assessed by the OGIS index and β-cell function by C-peptide analysis; fractional GGT (b-, s-, m-, and f-GGT) analysis was performed by gel-filtration chromatography. At T15, total GGT activity decreased by 40% after LSG (p = 0.007) but remained unchanged after RYGB. At T365, all patients showed a reduction in total GGT, in particular b-GGT (≥ 60%) and m-GGT (≥ 50%). In patients with biopsy-proven steatohepatitis (n = 10), total, b-, s-, and m-GGT fractions at T0 were significantly higher than in patients with low-grade steatosis (p = 0.016, 0.0003, and 0.005, respectively); at T365, there was a significant fall in total GGT as well as in each fraction in both groups. In a multiple regression model, b-GGT was the only fraction related to insulin sensitivity (p = 0.016; β coeff. = - 14.0) independently of BMI, fasting glucose, and triglycerides. While GGT activity is generally associated with impaired glucose metabolism, fractional GGT analysis showed that the b-GGT fraction specifically and independently tracks with insulin resistance.

Clinical utility of urine kidney injury molecule-1 (KIM-1) and gamma-glutamyl transferase (GGT) in the diagnosis of canine acute kidney injury.

PubMed

Lippi, Ilaria; Perondi, F; Meucci, V; Bruno, B; Gazzano, V; Guidi, G

2018-06-01

The aim of the present study was to evaluate the sensitivity and specificity of urine KIM-1 and urine GGT for the detection of naturally-occurring AKI, compared to healthy control dogs, dogs with stable chronic kidney disease (CKD), and dogs with lower urinary tract disorders (LUTD). The study included AKI grade 1 (n = 21), AKI grade 2 to 5 (n = 11), stable CKD (n = 11), LUTD (n = 15), and healthy dogs (n = 37). Urine KIM-1 (ng/mg) and GGT (U/l) were normalized to urine creatinine (uCr). Statistically significant difference in KIM/uCr (p = 0.0007) and GGT/uCr (p < 0.0001) was found among the study groups. Area under the curve (AUC) for KIM-1/uCr and GGT/uCr as predictors of AKI was 0.81 and 0.91 respectively. Values of KIM-1/uCr of 0.73 ng/mg and of GGT/uCr of 54.33 showed the best combination of sensitivity and specificity (75% and 75.6%; 85.7% and 89.1% respectively). A significant positive correlation (p < 0.0001) between KIM-1/uCr and GGT/uCr was found. Both urine KIM-1/uCr and GGT/uCr seemed to be potentially good markers for the diagnosis of AKI. Dogs with AKI showed significantly higher levels of urine KIM-1/uCr and urine GGT/uCr, compared with healthy dogs. Caution should be used in the evaluation of elevated urine KIM-1/uCr and GGT/uCr in dogs with pre-existing CKD and/or LUTD. Urine KIM-1/uCr and GGT/uCr might have a significant clinical utility, as complementary test, particularly in diagnosis early, non-azotemic stages of AKI.

Capsule Depolymerase Overexpression Reduces Bacillus anthracis Virulence

DTIC Science & Technology

2010-01-01

protein that autocatalytically forms a heterodimer consisting of 35 kDa and 15 kDa subunits. CapD shares 32 % identity with the Bacillus subtilis GGT and 35...Immun 49, 291–297. Kimura, K., Tran, L. S., Uchida, I. & Itoh, Y. (2004). Characterization of Bacillus subtilis gamma-glutamyltransferase and its...Capsule depolymerase overexpression reduces Bacillus anthracis virulence Angelo Scorpio,3 Donald J. Chabot, William A. Day,4 Timothy A. Hoover and

Serum γ-glutamyltransferase and associated damage among a She Chinese population.

PubMed

Lin, Y; Xu, Y; Chen, G; Huang, B; Yao, J; Chen, Z; Yao, L; Lin, F; Qiao, Y; Chen, Z; Zhu, S; Huang, H; Wen, J

2011-08-01

It has been suggested that serum γ-glutamyltransferase is independently associated with cardiovascular mortality and atherosclerosis. The present study is to investigate the relationship between serum γ-glutamyltransferase and potential associated damage in an adult She Chinese population. A multistage, stratified, cluster, random sampling method was used to select an ethnically representative group of individuals aged 20-80 years in the general population. Brachial-ankle pulse-wave velocity was used to assess arterial stiffness in the general population and the Toronto Clinical Neuropathy Scoring System was used to detect diabetic peripheral polyneuropathy among populations with diabetes. A total of 5385 subjects were entered into the analysis. Serum γ-glutamyltransferase levels were classified into four groups using the 25th, 50th and 75th percentiles as cut points (males: < 20, 20-29, 29-52 and > 52 U/l; females: < 13, 13-18, 18-25 and > 25 U/l). As compared with the first quartile, the relative risks of arterial stiffness were 1.418, 1.667 and 2.394 in the other three categories, respectively (test for trend P < 0.05). After adjustment in five models, serum γ-glutamyltransferase was still a risk factor of arterial stiffness. We found inverted U-shape curves in both genders and the third quartile (male: 29 52 U/l; female: 18-25 U/l) had the highest odds ratios of 1.640 and 1.529, respectively. We demonstrated that high serum γ-glutamyltransferase concentrations were directly associated with the increased risk of arterial stiffness, in general, and with peripheral polyneuropathy in subjects with diabetes in an ethnic She Chinese population. Alcohol use, gender, BMI and blood pressure were related to serum γ-glutamyltransferase and were involved in the relationship between serum γ-glutamyltransferase and brachial-ankle pulse-wave velocity. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

The genetic architecture of liver enzyme levels: GGT, ALT and AST.

PubMed

van Beek, Jenny H D A; de Moor, Marleen H M; de Geus, Eco J C; Lubke, Gitta H; Vink, Jacqueline M; Willemsen, Gonneke; Boomsma, Dorret I

2013-07-01

High levels of liver enzymes GGT, ALT and AST are predictive of disease and all-cause mortality and can reflect liver injury, fatty liver and/or oxidative stress. Variation in GGT, ALT and AST levels is heritable. Moderation of the heritability of these liver enzymes by age and sex has not often been explored, and it is not clear to what extent non-additive genetic and shared environmental factors may play a role. To examine the genetic architecture of GGT, ALT and AST, plasma levels were assessed in a large sample of twins, their siblings, parents and spouses (N = 8,371; age range 18-90). For GGT and ALT, but not for AST, genetic structural equation modeling showed evidence for quantitative sex differences in the genetic architecture. There was no evidence for qualitative sex differences, i.e. the same genes were expressed in males and females. Both additive and non-additive genetic factors were important for GGT in females (total heritability h(2) 60 %) and AST in both sexes (total h(2) 43 %). The heritability of GGT in males and ALT for both sexes was due to additive effects only (GGT males 30 %; ALT males 40 %, females 22 %). Evidence emerged for shared environmental factors influencing GGT in the male offspring generation (variance explained 28 %). Thus, the same genes influence liver enzyme levels across sex and age, but their relative contribution to the variation in GGT and ALT differs in males and females and for GGT across age. Given adequate sample sizes these results suggest that genome-wide association studies may result in the detection of new susceptibility loci for liver enzyme levels when pooling results over sex and age.

Extreme furfural tolerance of a soil bacterium Enterobacter cloacae GGT036.

PubMed

Choi, Sun Young; Gong, Gyeongtaek; Park, Hong-Sil; Um, Youngsoon; Sim, Sang Jun; Woo, Han Min

2015-01-10

Detoxification process of cellular inhibitors including furfural is essential for production of bio-based chemicals from lignocellulosic biomass. Here we isolated an extreme furfural-tolerant bacterium Enterobacter cloacae GGT036 from soil sample collected in Mt. Gwanak, Republic of Korea. Among isolated bacteria, only E. cloacae GGT036 showed cell growth with 35 mM furfural under aerobic culture. Compared to the maximal half inhibitory concentration (IC50) of well-known industrial strains Escherichia coli (24.9 mM furfural) and Corynebacterium glutamicum (10 mM furfural) based on the cell density, IC50 of E. cloacae GGT036 (47.7 mM) was significantly higher after 24 h, compared to E. coli and C. glutamicum. Since bacterial cell growth was exponentially inhibited depending on linearly increased furfural concentrations in the medium, we concluded that E. cloacae GGT036 is an extreme furfural-tolerant bacterium. Recently, the complete genome sequence of E. cloacae GGT036 was announced and this could provide an insight for engineering of E. cloacae GGT036 itself or other industrially relevant bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

Reversible skeletal abnormalities in gamma-glutamyl transpeptidase-deficient mice

NASA Technical Reports Server (NTRS)

Levasseur, Regis; Barrios, Roberto; Elefteriou, Florent; Glass, Donald A 2nd; Lieberman, Michael W.; Karsenty, Gerard

2003-01-01

Gamma-glutamyl transpeptidase (GGT) is a widely distributed ectopeptidase responsible for the degradation of glutathione in the gamma-glutamyl cycle. This cycle is implicated in the metabolism of cysteine, and absence of GGT causes a severe intracellular decrease in this amino acid. GGT-deficient (GGT-/-) mice have multiple metabolic abnormalities and are dwarf. We show here that this latter phenotype is due to a decreased of the growth plate cartilage total height resulting from a proliferative defect of chondrocytes. In addition, analysis of vertebrae and tibiae of GGT-/- mice revealed a severe osteopenia. Histomorphometric studies showed that this low bone mass phenotype results from an increased osteoclast number and activity as well as from a marked decrease in osteoblast activity. Interestingly, neither osteoblasts, osteoclasts, nor chondrocytes express GGT, suggesting that the observed defects are secondary to other abnormalities. N-acetylcysteine supplementation has been shown to reverse the metabolic abnormalities of the GGT-/- mice and in particular to restore the level of IGF-1 and sex steroids in these mice. Consistent with these previous observations, N-acetylcysteine treatment of GGT-/- mice ameliorates their skeletal abnormalities by normalizing chondrocytes proliferation and osteoblastic function. In contrast, resorbtion parameters are only partially normalized in GGT-/- N-acetylcysteine-treated mice, suggesting that GGT regulates osteoclast biology at least partly independently of these hormones. These results establish the importance of cysteine metabolism for the regulation of bone remodeling and longitudinal growth.

Association between liver function and metabolic syndrome in Chinese men and women

PubMed Central

Wang, Sen; Zhang, Jie; Zhu, Li; Song, Linlin; Meng, Zhaowei; Jia, Qiang; Li, Xue; Liu, Na; Hu, Tianpeng; Zhou, Pingping; Zhang, Qing; Liu, Li; Song, Kun; Jia, Qiyu

2017-01-01

Metabolic syndrome (MS) could be associated with liver function. Our study aimed to investigate the association between liver function and MS in a large cohort of Chinese men and women. We enrolled 32,768 ostensibly healthy participants. The associations between liver function and MS of both genders were analyzed separately after dividing total bilirubin (TBIL), gamma glutamyltransferase (GGT), alanine aminotransferase (ALT) into quartiles. Young males had significantly higher MS prevalence than females, yet after menopause, females had higher MS prevalence. We used TBIL, GGT and ALT quartiles as categorical variables in binary logistic regression models. Significantly decreased MS risks were demonstrated in TBIL quartiles 2 to 4 for males, and quartiles 3 to 4 for females. As to GGT and ALT, significantly increased MS risks were shown in high quartiles for both genders. Aging also resulted in significantly higher MS risks in both genders except for young females. This study displayed close associations between liver function and MS, which were influenced by gender and age. A high TBIL level had protective effect against MS, while high GGT and ALT levels were risk factors for MS. It is meaningful that liver function is used as clinical risk predictors for MS. PMID:28317840

[Prediction of histological liver damage in asymptomatic alcoholic patients by means of clinical and laboratory data].

PubMed

Iturriaga, H; Hirsch, S; Bunout, D; Díaz, M; Kelly, M; Silva, G; de la Maza, M P; Petermann, M; Ugarte, G

1993-04-01

Looking for a noninvasive method to predict liver histologic alterations in alcoholic patients without clinical signs of liver failure, we studied 187 chronic alcoholics recently abstinent, divided in 2 series. In the model series (n = 94) several clinical variables and results of common laboratory tests were confronted to the findings of liver biopsies. These were classified in 3 groups: 1. Normal liver; 2. Moderate alterations; 3. Marked alterations, including alcoholic hepatitis and cirrhosis. Multivariate methods used were logistic regression analysis and a classification and regression tree (CART). Both methods entered gamma-glutamyltransferase (GGT), aspartate-aminotransferase (AST), weight and age as significant and independent variables. Univariate analysis with GGT and AST at different cutoffs were also performed. To predict the presence of any kind of damage (Groups 2 and 3), CART and AST > 30 IU showed the higher sensitivity, specificity and correct prediction, both in the model and validation series. For prediction of marked liver damage, a score based on logistic regression and GGT > 110 IU had the higher efficiencies. It is concluded that GGT and AST are good markers of alcoholic liver damage and that, using sample cutoffs, histologic diagnosis can be correctly predicted in 80% of recently abstinent asymptomatic alcoholics.

Liver enzymes compared with alcohol consumption in predicting the risk of type 2 diabetes: the Kansai Healthcare Study.

PubMed

Sato, Kyoko Kogawa; Hayashi, Tomoshige; Nakamura, Yoshiko; Harita, Nobuko; Yoneda, Takeshi; Endo, Ginji; Kambe, Hiroshi

2008-06-01

It has been reported that moderate alcohol consumption decreased the risk of type 2 diabetes but that elevated liver enzymes increased it. The comparative importance of alcohol consumption and liver enzymes as predictors of type 2 diabetes remains unconfirmed. The participants included 8,576 Japanese men, aged 40-55 years, without type 2 diabetes at entry. Type 2 diabetes was diagnosed if a fasting plasma glucose level was >or=126 mg/dl or if participants were taking oral hypoglycemic medications or insulin. During the 4-year follow-up period, we confirmed 878 cases. In multivariate models, moderate daily alcohol consumption (16.4-42.6 g ethanol/day) decreased the risk of type 2 diabetes, and higher levels of gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT) increased the risk. In joint analyses of alcohol consumption and liver enzymes, moderate drinkers with the lowest tertile of GGT had the lowest risk of type 2 diabetes. Compared with them, nondrinkers with the highest GGT had the highest risk of type 2 diabetes (odds ratio 3.18 [95% CI 1.75-5.76]). At every level of GGT, moderate or heavy alcohol drinkers (>or=42.7 g ethanol/day) had a lower risk of type 2 diabetes than nondrinkers. The relationship of ALT and daily alcohol consumption with the risk of type 2 diabetes was almost the same as that of GGT. GGT, ALT, and daily alcohol consumption were independently associated with the risk of type 2 diabetes. Nondrinkers with the highest GGT or ALT had a high risk of type 2 diabetes.

A gamma-glutamyl transpeptidase-independent pathway of glutathione catabolism to glutamate via 5-oxoproline in Arabidopsis.

PubMed

Ohkama-Ohtsu, Naoko; Oikawa, Akira; Zhao, Ping; Xiang, Chengbin; Saito, Kazuki; Oliver, David J

2008-11-01

The degradation pathway of glutathione (GSH) in plants is not well understood. In mammals, GSH is predominantly metabolized through the gamma-glutamyl cycle, where GSH is degraded by the sequential reaction of gamma-glutamyl transpeptidase (GGT), gamma-glutamyl cyclotransferase, and 5-oxoprolinase to yield glutamate (Glu) and dipeptides that are subject to peptidase action. In this study, we examined if GSH is degraded through the same pathway in Arabidopsis (Arabidopsis thaliana) as occurs in mammals. In Arabidopsis, the oxoprolinase knockout mutants (oxp1-1 and oxp1-2) accumulate more 5-oxoproline (5OP) and less Glu than wild-type plants, suggesting substantial metabolite flux though 5OP and that 5OP is a major contributor to Glu steady-state levels. In the ggt1-1/ggt4-1/oxp1-1 triple mutant with no GGT activity in any organs except young siliques, the 5OP concentration in leaves was not different from that in oxp1-1, suggesting that GGTs are not major contributors to 5OP production in Arabidopsis. 5OP formation strongly tracked the level of GSH in Arabidopsis plants, suggesting that GSH is the precursor of 5OP in a GGT-independent reaction. Kinetics analysis suggests that gamma-glutamyl cyclotransferase is the major source of GSH degradation and 5OP formation in Arabidopsis. This discovery led us to propose a new pathway for GSH turnover in plants where GSH is converted to 5OP and then to Glu by the combined action of gamma-glutamyl cyclotransferase and 5-oxoprolinase in the cytoplasm.

Evaluation of passive transfer in captive greater kudu (Tragelaphus strepsiceros).

PubMed

Hammond, Elizabeth E; Fiorello, Christine V

2011-12-01

Failure of passive transfer (FPT) in captive greater kudu (Tragelaphus strepsiceros) calves can lead to increased morbidity and mortality. In this retrospective study, serum samples from neonatal kudu calves were tested for immunoglobulin using different tests validated for domestic ruminants, including measurement of gamma globulin (GG) measured by protein electrophoresis, total solids (TS) measured by calibrated refractometry, total protein (TP) and globulins measured by colorimetry, gamma glutamyltransferase (GGT), and the zinc sulfate turbidity test (ZSTT). In a logistic regression model, TP, TS, globulins, and the natural log transform of GGT were the only significant parameters associated with FPT. Various historic parameters related to the dam, as well as calf weight, sex, glucose, and packed cell volume, were not significant. Based on the results, FPT in greater kudu is defined as GG of < 0.5 g/dl, a value lower than that in domestic cattle. TS measured by refractometry has an 80% sensitivity and a 100% specificity for FPT in greater kudu. With FPT defined as GG < 0.5 g/dl, kudu calves with a TS < 4.8 g/dl and a negative ZSTT have an increased probability of requiring medical intervention and additional diagnostics may be warranted.

Structure of 6-diazo-5-oxo-norleucine-bound human gamma-glutamyl transpeptidase 1, a novel mechanism of inactivation.

PubMed

Terzyan, Simon S; Cook, Paul F; Heroux, Annie; Hanigan, Marie H

2017-06-01

Intense efforts are underway to identify inhibitors of the enzyme gamma-glutamyl transpeptidase 1 (GGT1) which cleaves extracellular gamma-glutamyl compounds and contributes to the pathology of asthma, reperfusion injury and cancer. The glutamate analog, 6-diazo-5-oxo-norleucine (DON), inhibits GGT1. DON also inhibits many essential glutamine metabolizing enzymes rendering it too toxic for use in the clinic as a GGT1 inhibitor. We investigated the molecular mechanism of human GGT1 (hGGT1) inhibition by DON to determine possible strategies for increasing its specificity for hGGT1. DON is an irreversible inhibitor of hGGT1. The second order rate constant of inactivation was 0.052 mM -1 min -1 and the K i was 2.7 ± 0.7 mM. The crystal structure of DON-inactivated hGGT1 contained a molecule of DON without the diazo-nitrogen atoms in the active site. The overall structure of the hGGT1-DON complex resembled the structure of the apo-enzyme; however, shifts were detected in the loop forming the oxyanion hole and elements of the main chain that form the entrance to the active site. The structure of hGGT1-DON complex revealed two covalent bonds between the enzyme and inhibitor which were part of a six membered ring. The ring included the OG atom of Thr381, the reactive nucleophile of hGGT1 and the α-amine of Thr381. The structure of DON-bound hGGT1 has led to the discovery of a new mechanism of inactivation by DON that differs from its inactivation of other glutamine metabolizing enzymes, and insight into the activation of the catalytic nucleophile that initiates the hGGT1 reaction. © 2017 The Protein Society.

Liver enzymes, the metabolic syndrome, and incident diabetes: the Mexico City diabetes study.

PubMed

Nannipieri, Monica; Gonzales, Clicerio; Baldi, Simona; Posadas, Rosalinda; Williams, Ken; Haffner, Steven M; Stern, Michael P; Ferrannini, Ele

2005-07-01

To test the hypothesis that enzymes conventionally associated with liver dysfunction (aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase [GGT], and alkaline phosphatase) may predict diabetes. From a population-based diabetes survey, we selected 1,441 men and women in whom serum enzyme levels were < or =3 SDs of the mean population value, alcohol intake was <250 g/week, and hepatitis B and C virus testing was negative. At follow-up (7 years), 94 subjects developed diabetes and 93 impaired glucose tolerance (IGT). At baseline, all four enzymes were related to most of the features of the metabolic syndrome. After controlling for sex, age, adiposity/fat distribution, alcohol intake, serum lipids, and blood pressure, higher alanine aminotransferase and GGT values were significantly (P < 0.01) associated with both IGT and diabetes, whereas alkaline phosphatase was associated with diabetes only (P = 0.0004) and aspartate aminotransferase with IGT only (P = 0.0001). Raised GGT alone was associated with all the features of the metabolic syndrome. Raised GGT was a significant predictor of either IGT or diabetes (odds ratio 1.62 [95% CI 1.08-2.42] top quartile vs. lower quartiles, P < 0.02) after controlling for sex, age, adiposity/fat distribution, alcohol consumption, fasting plasma insulin and proinsulin levels, and 2-h postglucose plasma glucose concentrations. Although mild elevations in liver enzymes are associated with features of the metabolic syndrome, only raised GGT is an independent predictor of deterioration of glucose tolerance to IGT or diabetes. As GGT signals oxidative stress, the association with diabetes may reflect both hepatic steatosis and enhanced oxidative stress.

High Liver Enzyme Concentrations are Associated with Higher Glycemia, but not with Glycemic Variability, in Individuals without Diabetes Mellitus.

PubMed

Noordam, Raymond; Vermond, Debbie; Drenth, Hermijntje; Wijman, Carolien A; Akintola, Abimbola A; van der Kroef, Sabrina; Jansen, Steffy W M; Huurman, Neline C; Schutte, Bianca A M; Beekman, Marian; Slagboom, P Eline; Mooijaart, Simon P; van Heemst, Diana

2017-01-01

Elevated concentrations of liver enzymes have been associated with an increased risk of developing type 2 diabetes mellitus. However, it remains unclear to which specific aspects of diurnal glucose metabolism these associate most. We aimed to investigate the associations between liver enzyme concentrations and 24 h-glucose trajectories in individuals without diabetes mellitus from three independent cohorts. This cross-sectional study included 436 participants without diabetes mellitus from the Active and Healthy Aging Study, the Switchbox Study, and the Growing Old Together Study. Fasting blood samples were drawn to measure gamma-glutamyltransferase (GGT), alanine transaminase, and aspartate transaminase. Measures of glycemia (e.g., nocturnal and diurnal mean glucose levels) and glycemic variability (e.g., mean amplitude of glucose excursions) were derived from continuous glucose monitoring. Analyses were performed separately for the three cohorts; derived estimates were additionally meta-analyzed. After meta-analyses of the three cohorts, elevated liver enzyme concentrations, and specifically elevated GGT concentrations, were associated with higher glycemia. More specific, participants in the highest GGT tertile (GGT ≥37.9 U/L) had a 0.39 mmol/L (95% confidence interval: 0.23, 0.56) higher mean nocturnal glucose (3:00 to 6:00 a.m.) and a 0.23 mmol/L (0.10, 0.36) higher diurnal glucose (6:00 to 0:00 a.m.) than participants in the lowest GGT tertile (GGT <21.23 U/L). However, elevated liver enzyme concentrations were not associated with a higher glycemic variability. Though elevated liver enzyme concentrations did not associate with higher glycemic variability in participants without diabetes mellitus, specifically, elevated GGT concentrations associated with higher glycemia.

Expression optimization and biochemical characterization of a recombinant gamma-glutamyltranspeptidase from Escherichia coli novablue.

PubMed

Yao, Ya-Feng; Weng, Yih-Ming; Hu, Hui-Yu; Ku, Kuo-Lung; Lin, Long-Liu

2006-09-01

A truncated Escherichia coli Novablue gamma-glutamyltranspeptidase (EcGGT) gene lacking the first 48-bp coding sequence for part of the signal sequence was amplified by polymerase chain reaction and cloned into expression vector pQE-30 to generate pQE-EcGGT. The maximum production of His(6)-tagged enzyme by E. coli M15 (pQE-EcGGT) was achieved with 0.1 mM IPTG induction for 12 h at 20 degrees C. The overexpressed enzyme was purified to homogeneity by nickel-chelate chromatography to a specific transpeptidase activity of 4.25 U/mg protein and a final yield of 83%. The molecular masses of the subunits of the purified enzyme were estimated to be 41 and 21 kDa respectively by SDS-PAGE, indicating EcGGT still undergoes the post-translational cleavage even in the truncation of signal sequence. The optimum temperature and pH for the recombinant enzyme were 40 degrees C and 9, respectively. The apparent K (m) and V (max) values for gamma-glutamyl-p-nitroanilide as gamma-glutamyl donor in the transpeptidation reaction were 37.9 microM and 53.7 x 10(-3) mM min(-1), respectively. The synthesis of L -theanine was performed in a reaction mixture containing 10 mM L -Gln, 40 mM ethylamine, and 1.04 U His(6)-tagged EcGGT/ml, pH 10, and a conversion rate of 45% was obtained.

A cluster version of the GGT sum rule

NASA Astrophysics Data System (ADS)

Hencken, Kai; Baur, Gerhard; Trautmann, Dirk

2004-03-01

We discuss the derivation of a "cluster sum rule" from the Gellmann-Goldberger-Thirring (GGT) sum rule as an alternative to the Thomas-Reiche-Kuhn (TRK) sum rule, which was used as the basis up to now. We compare differences in the assumptions and approximations. Some applications of the sum rule for halo nuclei, as well as, nuclei with a pronounced cluster structure are discussed.

Serum GGT activity and hsCRP level in patients with type 2 diabetes mellitus with good and poor glycemic control: An evidence linking oxidative stress, inflammation and glycemic control.

PubMed

Gohel, Mukesh G; Chacko, Anusha N

2013-12-20

Diabetes is undoubtedly one of the most challenging health problems in 21st century. Understanding the pathogenesis and preventing long term complications have been major goals of research in diabetes mellitus (DM). Research in the past few years has linked oxidative stress and inflammation to beta cell dysfunction. Aim of this study is to evaluate serum gamma-glutamyl transferase (GGT) activity (marker of oxidative stress) and high sensitivity C reactive protein (hsCRP) level (an inflammatory marker) in type 2 DM subjects with good and poor glycemic control. Further, we investigated correlation between serum GGT and hsCRP level with glycemic control (FBS, PP2BS, HbA1c) in subjects. A cross sectional study consists of 150 patients out of them 50 patients having type 2 DM with good control (Group II), 50 patients with type 2 DM with poor control (Group III) and 50 normal healthy control (Group I) were selected. Serum GGT, serum hsCRP, FBS, PP2BS, HbA1c, and other biochemical investigations include serum liver enzymes and lipids were measured. Mean serum GGT and hsCRP concentration were statistically significantly higher in group III patients compared to group I and group II subjects as well as increased in group II compared to group I (p < 0.001). Further significant positive correlation was observed between GGT and hsCRP concentration as well as both with HbA1c, FBS, and PP2BS. Oxidative stress and inflammation appears to be a key component and also associated with poor glycemic control and further pathogenesis of diabetes and its complications. All our finding suggesting a link between oxidative stress, inflammation and glycemic control in patient with type 2 diabetes mellitus.

Gamma glutamyl transferase and oxidative stress in obstructive sleep apnea: a study in 1744 patients.

PubMed

Sánchez-Armengol, A; Villalobos-López, P; Caballero-Eraso, C; Carmona-Bernal, C; Asensio-Cruz, M; Barbé, F; Capote, F

2015-09-01

We analyze a large population of patients to determine whether gamma glutamyl transferase (GGT) levels are increased in sleep apnea-hypopnea syndrome (OSA) and whether these levels are related to clinical characteristics or polygraphic indexes. A cross-sectional study in a population of 1744 patients referred for OSA suspicion was conducted. The following variables were determined: glucose, cholesterol, triglycerides, aspartate aminotransferase (GOT), alanine aminotransferase (GPT), GGT, body mass index, waist-hip ratio (WHR), and overnight sleep study. The 483 patients with GGT ≥40 IU/l were younger and more obese, and had a pattern of more centrally distributed fat than the 1261 with GGT <40 IU/l. Patients with high levels of GGT also consumed more alcohol, had a poorer biochemical profile, and had more respiratory and oximetric alterations during sleep. GGT levels were significantly correlated with AHI, DI, and CT90. In the binary regression test, WHR, glucose, cholesterol, triglycerides, and grams of alcohol consumed per day predicted GGT levels ≥40 IU/l, while none of the polygraphic variables had predictive value. High GGT levels were associated with the severity of OSA. However, this relationship seems to be due to the coexistence of other associated factors, mainly central obesity, rather than to the respiratory disorders found in this disease.

Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth.

PubMed

Dellero, Younès; Lamothe-Sibold, Marlène; Jossier, Mathieu; Hodges, Michael

2015-09-01

Metabolic and physiological analyses of glutamate:glyoxylate aminotransferase 1 (GGT1) mutants were performed at the global leaf scale to elucidate the mechanisms involved in their photorespiratory growth phenotype. Air-grown ggt1 mutants showed retarded growth and development, that was not observed at high CO2 (3000 μL L(-1) ). When compared to wild-type (WT) plants, air-grown ggt1 plants exhibited glyoxylate accumulation, global changes in amino acid amounts including a decrease in serine content, lower organic acid levels, and modified ATP/ADP and NADP(+) /NADPH ratios. When compared to WT plants, their net CO2 assimilation rates (An ) were 50% lower and this mirrored decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents. High CO2 -grown ggt1 plants transferred to air revealed a rapid decrease of An and photosynthetic electron transfer rate while maintaining a high energetic state. Short-term (a night period and 4 h of light) transferred ggt1 leaves accumulated glyoxylate and exhibited low serine contents, while other amino acid levels were not modified. RuBisCO content, activity and activation state were not altered after a short-term transfer while the ATP/ADP ratio was lowered in ggt1 rosettes. However, plant growth and RuBisCO levels were both reduced in ggt1 leaves after a long-term (12 days) acclimation to air from high CO2 when compared to WT plants. The data are discussed with respect to a reduced photorespiratory carbon recycling in the mutants. It is proposed that the low An limits nitrogen-assimilation, this decreases leaf RuBisCO content until plants attain a new homeostatic state that maintains a constant C/N balance and leads to smaller, slower growing plants. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Clinical usefulness of metabolic risk factors to identify young asymptomatic women adults with subclinical atherosclerosis: A cross-sectional study.

PubMed

Qin, Guangming; Chen, Zhihao; Su, Weiwei; Geng, Xiaoge; Chen, Xiaojun; Xu, Xiang; Pan, Wensheng

2017-03-01

Interventions of cardiovascular disease should be implemented in early ages. But most studies were performed in middle aged or elderly adults because of the low prevalence in young, especially for women. We investigate the association between metabolic risk factors and subclinical atherosclerosis in young asymptomatic women adults, using carotid intima-media thickness (CIMT) as a marker of the atherosclerotic process.We performed a cross-sectional study of 950 Chinese young asymptomatic women adults (37.28 ± 5.16 years) who underwent a routine health screening examination. Triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), fasting blood glucose (FBG), homocysteine (HCY), gamma glutamyltransferase (GGT), uric acid, and CIMT were measured.Out of 950 subjects, 16 (1.7%) were detected with increased CIMT. Significant differences existed in the indicators including age, body mass index (BMI), TC, TG, LDL-C, LDL-C/HDL-C, non-HDL-C, and TC/HDL-C. Although TG, LDL-C, non-HDL-C, TC/HDL-C, and TG/HDL-C were the significant indicators when adjusted for age only, age, LDL-C/HDL-C, FBG, and GGT were the only independent relative indicators of increased CMIT that entered the multivariate model. The area under receiver operating characteristic curve for a linear combination of age, LDL-C/HDL-C, FBG, and GGT was 0.809 (95% confidence interval = 0.712-0.906), superior to any of the variables taken alone (age, AUC = 0.707; FBG, AUC = 0.710; LDL-C/HDL-C, AUC = 0.695; GGT, AUC = 0.648).The combined assessment of age, LDL-C/HDL-C, FBG, and GGT contributes to an early detection for subclinical atherosclerosis, providing guidance to clinicians for women's early interventions of latent cardiovascular disease. Neither of the above four individual indicators is qualified alone.

gamma-Glutamyl transpeptidase overexpression increases metastatic growth of B16 melanoma cells in the mouse liver.

PubMed

Obrador, Elena; Carretero, Julian; Ortega, Angel; Medina, Ignacio; Rodilla, Vicente; Pellicer, José A; Estrela, José M

2002-01-01

B16 melanoma (B16M) cells with high glutathione (GSH) content show rapid proliferation in vitro and high metastatic activity in the liver in vivo. gamma-Glutamyl transpeptidase (GGT)-mediated extracellular GSH cleavage and intracellular GSH synthesis were studied in vitro in B16M cells with high (F10) and low (F1) metastatic potential. GGT activity was modified by transfection with the human GGT gene (B16MF1/Tet-GGT cells) or by acivicin-induced inhibition. B16MF1/Tet-GGT and B16MF10 cells exhibited higher GSH content (35 +/- 6 and 40 +/- 5 nmol/10(6) cells, respectively) and GGT activity (89 +/- 9 and 37 +/- 7 mU/10(6) cells, respectively) as compared (P <.05) with B16MF1 cells (10 +/- 3 nmol GSH and 4 mU GGT/10(6) cells). Metastasis (number of foci/100 mm(3) of liver) increased in B16MF1 cells pretreated with GSH ester ( approximately 3-fold, P <.01), and decreased in B16MF1/Tet-GGT and B16MF10 cells pretreated with the GSH synthesis inhibitor L-buthionine (S,R)-sulphoximine ( approximately 5-fold and 2-fold, respectively, P <.01). Liver, kidney, brain, lung, and erythrocyte GSH content in B16MF1/Tet-GGT- or B16MF10-bearing mice decreased as compared with B16MF1- and non-tumor-bearing mice. Organic anion transporting polypeptide 1-independent sinusoidal GSH efflux from hepatocytes increased in B16MF1/Tet-GGT- or B16MF10-bearing mice ( approximately 2-fold, P <.01) as compared with non-tumor-bearing mice. Our results indicate that tumor GGT activity and an intertissue flow of GSH can regulate GSH content of melanoma cells and their metastatic growth in the liver.

Association between gamma glutamyl transferase and insulin resistance markers in healthy obese children.

PubMed

Kaushik, Girdhar Gopal; Sharm, Sonali; Sharma, Reenu; Mittal, Prerna

2009-10-01

To study the relationship of gamma glutamyl transferase (GGT) with insulin resistance markers [fasting insulin and Homeostasis Model Assessment of-insulin resistance (HOMA-IR)] and to assess the role of GGT as a determinant of insulin resistance in healthy obese children. Fifty healthy obese children (boys and girls with mean age 9.2 +/- 0.73 and 8.8 +/- 0.74 years) born to diabetic mothers were studied. In all the subjects, anthropometric measurements viz, BMI and body weight were studied. The biochemical parameters analysed in fasting samples of subjects were plasma glucose, plasma insulin, serum GGT and calculation of HOMA-IR. The fifty studied subjects belonged to age group 8 to12 years. The difference in mean age of boys and girls was not significant (p = 0.09). Body weight values in all subjects ranged from 20 to 78 kgs and BMI values ranged from 14.5 to 42.1 Kg/m2. No significant difference was observed between body weight and BMI values when compared between boys and girls. A similar trend was observed in the values of biochemical parameters viz, fasting glucose, fasting insulin and HOMA-IR levels when compared between boys and girls (p = 0.72, p = 0.80, p = 0.59). Serum GGT correlated significantly with age, body weight, BMI, fasting insulin and HOMA-IR levels. HOMA-IR values also showed significant correlation with body weight, BMI, fasting glucose and fasting insulin levels. The association of GGT with fasting insulin and HOMA-IR levels was considerably significant compared to its association with other variables. The serum activity of GGT remained correlated with HOMA-IR even after removing the effect of BMI, weight and age on GGT values. The results showed that GGT is a determinant of HOMA-IR independently of age, BMI and weight. A correlation exists between GGT and insulin resistance markers. The observed correlation indicates that monitoring GGT and fasting insulin levels in obese children might serve to help prevent the development of diabetes in

Mediating effects of motor performance, cardiorespiratory fitness, physical activity, and sedentary behaviour on the associations of adiposity and other cardiometabolic risk factors with academic achievement in children.

PubMed

Haapala, Eero A; Lintu, Niina; Eloranta, Aino-Maija; Venäläinen, Taisa; Poikkeus, Anna-Maija; Ahonen, Timo; Lindi, Virpi; Lakka, Timo A

2018-03-09

We investigated the associations of cardiometabolic risk factors with academic achievement and whether motor performance, cardiorespiratory fitness, physical activity, or sedentary behaviour mediated these associations. Altogether 175 children 6-8 years-of-age participated in the study. We assessed body fat percentage (BF%), waist circumference, insulin, glucose, triglycerides, HDL cholesterol, and systolic and diastolic blood pressure, leptin, alanine aminotransferase, and gamma-glutamyltransferase (GGT). Reading fluency, reading comprehension, and arithmetic skills were assessed using standardized tests. Speed/agility, balance, and manual dexterity test results were used to calculate motor performance score and physical activity was assessed by combined heart rate and movement sensor and cardiorespiratory fitness by maximal cycle ergometer test. In boys, BF% was inversely associated with reading fluency (β = -0.262, P = 0.007) and reading comprehension (β = -0.216, P = 0.025). Motor performance mediated these associations. Leptin was inversely related to reading fluency (β = -0.272, P = 0.006) and reading comprehension (β = -0.287, P = 0.003). The inverse association of leptin with reading fluency was mediated by motor performance. In girls, GGT was inversely associated with reading fluency independent of confounders (β = -0.325, P = 0.007). The inverse association of BF% with academic achievement among boys was largely explained by motor performance. Leptin in boys and GGT in girls were inversely associated with academic achievement independent of confounding factors.

Serum Gamma-Glutamyl-Transferase Independently Predicts Outcome After Transarterial Chemoembolization of Hepatocellular Carcinoma: External Validation

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

Guiu, Boris, E-mail: boris.guiu@chu-dijon.fr; Deschamps, Frederic; Boulin, Mathieu

Purpose: An Asian study showed that gamma glutamyl transpeptidase (GGT) can predict survival after transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). This study was designed to validate in a European population this biomarker as an independent predictor of outcome after TACE of HCC and to determine a threshold value for clinical use. Methods: In 88 consecutive patients treated by TACE for HCC, the optimal threshold for GGT serum level was determined by a ROC analysis. Endpoints were time-to-treatment failure (TTTF) and overall survival (OS). All multivariate models were internally validated using bootstrapping (90 replications). Results: Median follow-up lasted 373 days,more » and median overall survival was 748 days. The optimal threshold for GGT was 165 U/L (sensitivity: 89.3%; specificity: 56.7%; area under the ROC curve: 0.7515). Median TTTF was shorter when GGT was {>=}165 U/L (281 days vs. 850 days; P < 0.001). GGT {>=}165 U/L (hazard ratio (HR) = 2.06; P = 0.02), WHO PS of 2 (HR = 5.4; P = 0.002), and tumor size (HR = 1.12; P = 0.014) were independently associated with shorter TTTF. Median OS was shorter when GGT was {>=}165 U/L (508 days vs. not reached; P < 0.001). GGT {>=} 165 U/L (HR = 3.05; P = 0.029), WHO PS of 2 (HR = 12.95; P < 0.001), alfa-fetoprotein (HR = 2.9; P = 0.01), and tumor size (HR = 1.096; P = 0.013) were independently associated with shorter OS. The results were confirmed by bootstrapping. Conclusions: Our results provide in a European population the external validation of GGT as an independent predictor of outcome after TACE of HCC. A serum level of GGT {>=} 165 U/L is independently associated with both shorter TTTF and OS.« less

Cerebrospinal fluid monocyte chemoattractant protein-1 in alcoholics: support for a neuroinflammatory model of chronic alcoholism.

PubMed

Umhau, John C; Schwandt, Melanie; Solomon, Matthew G; Yuan, Peixiong; Nugent, Allison; Zarate, Carlos A; Drevets, Wayne C; Hall, Samuel D; George, David T; Heilig, Markus

2014-05-01

Liver inflammation in alcoholism has been hypothesized to influence the development of a neuroinflammatory process in the brain characterized by neurodegeneration and altered cognitive function. Monocyte chemoattractant protein-1/chemokine (C-C motif) ligand 2 (MCP-1/CCL2) elevations have been noted in the alcoholic brain at autopsy and may have a role in this process. We studied cerebrospinal fluid (CSF) levels of MCP-1 as well as interleukin-1β and tumor necrosis factor-α in 13 healthy volunteers and 28 alcoholics during weeks 1 and 4 following detoxification. Serum liver enzymes were obtained as markers of alcohol-related liver inflammation. Compared to healthy volunteers, MCP-1 levels were significantly higher in alcoholics both on day 4 and day 25 (p < 0.0001). Using multiple regression analysis, we found that MCP-1 concentrations were positively associated with the liver enzymes gamma glutamyltransferase (GGT; p = 0.03) and aspartate aminotransferase/glutamic oxaloacetic transaminase (AST/GOT; p = 0.004). These preliminary findings are consistent with the hypothesis that neuroinflammation as indexed by CSF MCP-1 is associated with alcohol-induced liver inflammation, as defined by peripheral concentrations of GGT and AST/GOT. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Formation of Kokumi-Enhancing γ-Glutamyl Dipeptides in Parmesan Cheese by Means of γ-Glutamyltransferase Activity and Stable Isotope Double-Labeling Studies.

PubMed

Hillmann, Hedda; Behr, Jürgen; Ehrmann, Matthias A; Vogel, Rudi F; Hofmann, Thomas

2016-03-02

Recently, γ-glutamyl dipeptides (γ-GPs) were found to be responsible for the attractive kokumi flavor of Parmesan cheese (PC). Quantitation of γ-GPs and their parent amino acids in 13-, 24-, and 30-month ripened PC samples by LC-MS/MS and stable isotope dilution analysis (SIDA), in-cheese (13)C-labeling studies, followed by analysis of the γ-glutamyl transferase (GGT) activity revealed γ-GPs to be generated most efficiently after 24 months of ripening by a GGT-catalyzed transfer of the γ-glutamyl moiety of L-glutamine onto various acceptor amino acids released upon casein proteolysis. Following the identification of milk as a potential GGT source in PC, the functionality of the milk's GGT to generate the target γ-GPs was validated by stable isotope double-labeling (SIDL) experiments. Therefore, raw and heat-treated milk samples were incubated with L-glutamine-[U-(13)C] and acceptor amino acids (X) and the hetero- (γ-Glu-[(13)C5]-X) and homotranspeptidation products (γ-Glu-Gln-[(13)C10]) were quantitated by LC-MS/MS-SIDA using γ-Glu-Ala-[(13)C3] as the internal standard. High GGT activity to generate the γ-GPs and preference for L-phenylalanine and L-methionine as acceptor amino acids were found in raw milk and milk samples heat-treated for 10 min up to a maximum of 65 °C. In comparison, GGT activity and SIDL studies performed with inoculated Lactobacillus strains, including Lactobacillus harbinensis and Lactobacillus casei identified in PC by means of 16S rRNA gene sequencing, did not show any significant GGT activity and unequivocally demonstrated unpasteurized cow's milk, rather than microorganisms, as a key factor in γ-glutamyl dipeptide generation in Parmesan cheese.

Relationship between gamma-glutamyl transpeptidase activity and garlic greening, as controlled by temperature.

PubMed

Li, Lei; Hu, Dan; Jiang, Ying; Chen, Fang; Hu, Xiaosong; Zhao, Guanghua

2008-02-13

It was established that storage at low temperature (less than 10 degrees C) was required for garlic greening occurring either during processing or in the course of "Laba" garlic preparation while storage at high temperature (higher than 20 degrees C) inhibited its occurrence. However, the reason for this observation is unclear. To obtain insights into a tie connected between storage temperature and garlic greening, it was detected if the gamma-glutamyl transpeptidase (GGT) activity correlated with garlic greening because the activity of this enzyme is very sensitive to storage temperature. Results showed that garlic puree (which was prepared from fresh garlic) turned green upon addition of GGT but the color of garlic puree remained unchanged when either water or heat-treated GGT (which has no activity due to heat treatment) was used, a result giving a positive answer to the above proposal. Subsequently, to further clarify the relationship between the GGT activity and garlic greening, the GGT activity, the degree of garlic greening, and the concentration of total thiosulfinates in garlic bulbs were determined respectively after the garlic bulbs had been stored at 4 degrees C for up to 59 days followed by storage at 35 degrees C for up to 22 days. It was found that cold storage facilitated the GGT activity whereas warm storage inhibited the activity of this enzyme, just like the effect of storage temperature on greening, indicating that the increase of GGT activity could be a direct factor resulting in garlic greening. Consistent with this conclusion, the concentration of total thiosulfinates (the color developers) in garlic purees likewise exhibited a reversible change by moving garlic bulbs from one low storage temperature to a higher one; namely, it increased with increasing storage time during storage at 4 degrees C while decreasing as storage time increased during storage at 35 degrees C. The present study provided direct evidence that the GGT is involved in

Cross-sectional associations of total sitting and leisure screen time with cardiometabolic risk in adults. Results from the HUNT Study, Norway.

PubMed

Chau, Josephine Y; Grunseit, Anne; Midthjell, Kristian; Holmen, Jostein; Holmen, Turid L; Bauman, Adrian E; van der Ploeg, Hidde P

2014-01-01

To examine associations of total sitting time, TV-viewing and leisure-time computer use with cardiometabolic risk biomarkers in adults. Population based cross-sectional study. Waist circumference, BMI, total cholesterol, HDL cholesterol, blood pressure, non-fasting glucose, gamma glutamyltransferase (GGT) and triglycerides were measured in 48,882 adults aged 20 years or older from the Nord-Trøndelag Health Study 2006-2008 (HUNT3). Adjusted multiple regression models were used to test for associations between these biomarkers and self-reported total sitting time, TV-viewing and leisure-time computer use in the whole sample and by cardiometabolic disease status sub-groups. In the whole sample, reporting total sitting time ≥10 h/day was associated with poorer BMI, waist circumference, total cholesterol, HDL cholesterol, diastolic blood pressure, systolic blood pressure, non-fasting glucose, GGT and triglyceride levels compared to those reporting total sitting time <4h/day (all p<0.05). TV-viewing ≥4 h/day was associated with poorer BMI, waist circumference, total cholesterol, HDL cholesterol, systolic blood pressure, GGT and triglycerides compared to TV-viewing <1h/day (all p<0.05). Leisure-time computer use ≥1 h/day was associated with poorer BMI, total cholesterol, diastolic blood pressure, GGT and triglycerides compared with those reporting no leisure-time computing. Sub-group analyses by cardiometabolic disease status showed similar patterns in participants free of cardiometabolic disease, while similar albeit non-significant patterns were observed in those with cardiometabolic disease. Total sitting time, TV-viewing and leisure-time computer use are associated with poorer cardiometabolic risk profiles in adults. Reducing sedentary behaviour throughout the day and limiting TV-viewing and leisure-time computer use may have health benefits. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Independent and Co-morbid HIV Infection and Meth Use Disorders on Oxidative Stress Markers in the Cerebrospinal Fluid and Depressive Symptoms

PubMed Central

Panee, Jun; Pang, Xiaosha; Munsaka, Sody; Berry, Marla J.; Chang, Linda

2016-01-01

Both HIV infection and Methamphetamine (Meth) use disorders are associated with greater depressive symptoms and oxidative stress; whether the two conditions would show additive or interactive effects on the severity of depressive symptoms, and whether this is related to the level of oxidative stress in the CNS is unknown. 123 participants were evaluated, which included 41 HIV-seronegative subjects without substance use disorders (Control), 25 with recent (<6 months) moderate to severe Meth use disorders (Meth), 34 HIV-seropositive subjects without substance use disorders (HIV) and 23 HIV+Meth subjects. Depressive symptoms were assessed with the Center for Epidemiologic Studies-Depression Scale (CES-D), and oxidative stress markers were evaluated with glutathione (GSH), 4-hydroxynonenal (HNE), and activities of gamma-glutamyltransferase (GGT) and glutathione peroxidase (GPx) in the cerebrospinal fluid (CSF). Compared with Controls, HIV subjects had higher levels of HNE (+350 %) and GGT (+27 %), and lower level of GSH (−34 %), while Meth users had higher levels of GPx activity (+23 %) and GSH (+30 %). GGT correlated with GPx, and with age, across all subjects (p<0.0001). CES-D scores correlated with CSF HNE levels only in Control and HIV groups, but not in Meth and HIV+Meth groups. HIV and Meth use had an interactive effects on depressive symptoms, but did not show additive or interactive effects on oxidative stress. The differential relationship between depressive symptoms and oxidative stress response amongst the four groups suggest that depressive symptoms in these groups are mediated through different mechanisms which are not always related to oxidative stress. PMID:25575491

Independent and co-morbid HIV infection and Meth use disorders on oxidative stress markers in the cerebrospinal fluid and depressive symptoms.

PubMed

Panee, Jun; Pang, Xiaosha; Munsaka, Sody; Berry, Marla J; Chang, Linda

2015-03-01

Both HIV infection and Methamphetamine (Meth) use disorders are associated with greater depressive symptoms and oxidative stress; whether the two conditions would show additive or interactive effects on the severity of depressive symptoms, and whether this is related to the level of oxidative stress in the CNS is unknown. 123 participants were evaluated, which included 41 HIV-seronegative subjects without substance use disorders (Control), 25 with recent (<6 months) moderate to severe Meth use disorders (Meth), 34 HIV-seropositive subjects without substance use disorders (HIV) and 23 HIV+Meth subjects. Depressive symptoms were assessed with the Center for Epidemiologic Studies-Depression Scale (CES-D), and oxidative stress markers were evaluated with glutathione (GSH), 4-hydroxynonenal (HNE), and activities of gamma-glutamyltransferase (GGT) and glutathione peroxidase (GPx) in the cerebrospinal fluid (CSF). Compared with Controls, HIV subjects had higher levels of HNE (+350%) and GGT (+27%), and lower level of GSH (-34%), while Meth users had higher levels of GPx activity (+23%) and GSH (+30 %). GGT correlated with GPx, and with age, across all subjects (p < 0.0001). CES-D scores correlated with CSF HNE levels only in Control and HIV groups, but not in Meth and HIV+Meth groups. HIV and Meth use had an interactive effects on depressive symptoms, but did not show additive or interactive effects on oxidative stress. The differential relationship between depressive symptoms and oxidative stress response amongst the four groups suggest that depressive symptoms in these groups are mediated through different mechanisms which are not always related to oxidative stress.

Value of ethyl glucuronide in plasma as a biomarker for recent alcohol consumption in the emergency room.

PubMed

Neumann, Tim; Helander, Anders; Dahl, Helen; Holzmann, Tilly; Neuner, Bruno; Weiss-Gerlach, Edith; Müller, Christian; Spies, Claudia

2008-01-01

This emergency department (ED) study compared the value of plasma ethyl glucuronide (EtG) testing with the information about alcohol consumption obtained using the standard alcohol biomarkers gamma-glutamyltransferase (GGT) and carbohydrate-deficient transferring (CDT) and the AUDIT questionnaire. Minimally injured and clinically non-intoxicated male patients (n = 81) admitted to an ED were screened regarding their alcohol consumption, using the computerized AUDIT questionnaire and a paper-and-pencil assessment including the type, amount and time of alcohol intake. Blood samples were collected for determination of ethanol, EtG (LC-MS) and GGT in plasma and %CDT in serum (Axis-Shield %CDT immunoassay). Out of the 81 patients, 23 (28%) were positive (>/=8 points) on the AUDIT questionnaire. Only 3 (4%) showed a detectable ethanol concentration (range 0.01-0.07 g/L) but 31 (38%) showed a detectable EtG (0.16-39.5 mg/L). In four patients, EtG was detectable in plasma for >48 h after estimated completed elimination of ethanol. EtG was not correlated with the long-term biomarkers %CDT or GGT, or the AUDIT results, but with the time since estimated completed ethanol elimination. EtG testing in blood was found useful in the ED as a way to detect recent drinking, even in cases of a negative ethanol test, and to confirm abstinence from alcohol. This sensitive and specific short-term biomarker provides valuable additional information about individual drinking habits and might also be helpful to identify an alcohol hangover.

Are serum gamma-glutamyl transferase, high-sensitivity C-reactive protein, and ischaemia-modified albumin useful in diagnosing PCOS?

PubMed

Ozturk, Mustafa; Keskin, Ugur; Ozturk, Ozlem; Ulubay, Mustafa; Alanbay, İbrahim; Aydin, Aytekin; Yenen, Müfit Cemal

2016-10-01

We assessed the serum levels of gamma-glutamyl transferase (GGT), high-sensitivity C-reactive protein (hsCRP) and ischaemia-modified albumin (IMA) in patients with polycystic ovary syndrome (PCOS). Fifty-three patients with PCOS were included in our study along with 40 women with no PCOS as the control group. The patients were divided according to their body mass index (BMI). GGT levels were significantly higher in the women with PCOS than the women in the control group (p < 0.05). They were also significantly higher in the PCOS women who were normoweight and overweight than the normoweight and overweight women in the control group (p < 0.001). There was no significant difference in the circulating levels of hsCRP and IMA between the women with PCOS and the controls or between the normoweight and overweight subgroups. GGT may be associated with the diagnosis of PCOS when the threshold is set at >15.5 U/L. With the application of this threshold, raised GGT levels had 83% sensitivity (95% CI 0.70-0.90) and 67.5% specificity (95% CI 0.52-0.79), for the diagnosis of PCOS. In our study, GGT levels were elevated in the PCOS patients independent of BMI and could thus be an important marker of PCOS.

GGT (Gamma-Glutamyl Transferase) Test

MedlinePlus

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Hair mercury association with selenium, serum lipid spectrum, and gamma-glutamyl transferase activity in adults.

PubMed

Tinkov, Alexey A; Skalnaya, Margarita G; Demidov, Vasily A; Serebryansky, Eugeny P; Nikonorov, Alexandr A; Skalny, Anatoly V

2014-12-01

The primary objective of the research is to estimate the dependence between hair mercury content, hair selenium, mercury-to-selenium ratio, serum lipid spectrum, and gamma-glutamyl transferase (GGT) activity in 63 adults (40 men and 23 women). Serum triglyceride (TG) concentration in the high-mercury group significantly exceeded the values obtained for low- and medium-mercury groups by 72 and 42 %, respectively. Serum GGT activity in the examinees from high-Hg group significantly exceeded the values of the first and the second groups by 75 and 28 %, respectively. Statistical analysis of the male sample revealed similar dependences. Surprisingly, no significant changes in the parameters analyzed were detected in the female sample. In all analyzed samples, hair mercury was not associated with hair selenium concentrations. Significant correlation between hair mercury content and serum TG concentration (r = 0.531) and GGT activity (r = 0.524) in the general sample of the examinees was detected. The respective correlations were observed in the male sample. Hair mercury-to-selenium ratios significantly correlated with body weight (r = 0.310), body mass index (r = 0.250), serum TG (r = 0.389), atherogenic index (r = 0.257), and GGT activity (r = 0.393). The same correlations were observed in the male sample. Hg/Se ratio in women did not correlate with the analyzed parameters. Generally, the results of the current study show the following: (1) hair mercury is associated with serum TG concentration and GGT activity in men, (2) hair selenium content is not related to hair mercury concentration, and (3) mercury-to-selenium ratio correlates with lipid spectrum parameters and GGT activity.

Use of urinary γ-glutamyl transferase (GGT) to monitor the pattern of proteinuria in dogs with leishmaniasis treated with N-methylglucamine antimoniate.

PubMed

Paltrinieri, Saverio; Mangiagalli, Giulia; Ibba, Fabrizio

2018-05-25

The aim of this study was to assess if the coupled analysis of the urinary protein to creatinine (UPC) ratio and of the GGT/UC ratio (the ratio between urinary γ-glutamyl transferase activity and urinary creatinine) may be used in treated leishmaniotic dogs to differentiate dogs with transient impairment of tubular function from dogs with persistent tubular damage. To this aim, 40 urine from 10 proteinuric and leishmaniotic dogs that at the first visit had high GGT/UC ratio, consistent with tubular damage, were collected and analyzed before treatments and 2, 4 and 6 weeks after treatment with N-methylglucamine antimoniate and allopurinol. Compared with pre-treatment values, at the end of the study period the UPC ratio decreased only in 5/10 dogs, which, however, were still proteinuric or borderline proteinuric. Conversely, the GGT/CU ratio decreased in 8/10 dogs and in 3 of them the values at the end of the study period were below the threshold consistent with tubular proteinuria. The GGT/UC values at 6 weeks was significantly lower than before treatment. However, transient increases were frequent for both the analytes. These results indicate that in most of the dogs that remain proteinuric after treatment, likely due to the persistent glomerular damage, the GGT/UC ratio tends to normalize. This suggests that in these dogs tubular proteinuria at admission depends on functional impairment of tubular cells likely due to the overflow of proteins from damaged glomeruli. However, tubular proteinuria occasionally persists, suggesting that tubulointerstitial damages persist even in dogs responsive to treatments. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effects of Crataegus aronia var. dentata Browicz extract on biochemical indices and apoptosis in partially hepatectomized liver in rats.

PubMed

Keskin, Nazan; Mammadov, Ramazan; Ili, Pinar

2012-08-01

Crataegus species have been widely used in herbal medicine, especially for the hearth diseases. In the present study, the effect of Crataegus aronia var. dentata Browicz extract on partially hepatectomized rats was investigated with biochemical and TUNEL apoptosis assays. The extracts of the plant at the concentrations of 0.5 and 1 ml/100 g body weight/day were administered orally to the two experimental groups including partially hepatectomized rats for 42 days. At the end of the experimental period, animals were sacrificed, blood was collected for the assessment of serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), and the liver tissue was used for TUNEL assay. In biochemical assay, it was found a significant decrease in the levels of serum ALT and AST in the experimental groups. On the other hand, the plant extract did not cause any significant changes in the level of GGT in these groups. In apoptosis assay, TUNEL positive hepatocytes could not be detected in both experimental groups. The present findings can suggest that Crataegus aronia var. dentata Browicz extract can decrease the levels of serum ALT and AST and play a role in apoptosis of hepatocytes in the liver of partially hepatectomized rats. However, further studies are required to confirm the effects of the plant extract on hepatoprotection and apoptosis in the regenerating liver after partial hepatectomy in animal models.

Standardization of clinical enzyme analysis using frozen human serum pools with values assigned by the International Federation of Clinical Chemistry and Laboratory Medicine reference measurement procedures.

PubMed

Tong, Qing; Chen, Baorong; Zhang, Rui; Zuo, Chang

Variation in clinical enzyme analysis, particularly across different measuring systems and laboratories, represents a critical but long-lasting problem in diagnosis. Calibrators with traceability and commutability are imminently needed to harmonize analysis in laboratory medicine. Fresh frozen human serum pools were assigned values for alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), creatine kinase (CK) and lactate dehydrogenase (LDH) by six laboratories with established International Federation of Clinical Chemistry and Laboratory Medicine reference measurement procedures. These serum pools were then used across 76 laboratories as a calibrator in the analysis of five enzymes. Bias and imprecision in the measurement of the five enzymes tested were significantly reduced by using the value-assigned serum in analytical systems with open and single-point calibration. The median (interquartile range) of the relative biases of ALT, AST, GGT, CK and LDH were 2.0% (0.6-3.4%), 0.8% (-0.8-2.3%), 1.0% (-0.5-2.0%), 0.2% (-0.3-1.0%) and 0.2% (-0.9-1.1%), respectively. Before calibration, the interlaboratory coefficients of variation (CVs) in the analysis of patient serum samples were 8.0-8.2%, 7.3-8.5%, 8.1-8.7%, 5.1-5.9% and 5.8-6.4% for ALT, AST, GGT, CK and LDH, respectively; after calibration, the CVs decreased to 2.7-3.3%, 3.0-3.6%, 1.6-2.1%, 1.8-1.9% and 3.3-3.5%, respectively. The results suggest that the use of fresh frozen serum pools significantly improved the comparability of test results in analytical systems with open and single-point calibration.

Association of hepatic insulin resistance indexes to nonalcoholic fatty liver disease and related biomarkers.

PubMed

Sesti, G; Fiorentino, T V; Hribal, M L; Sciacqua, A; Perticone, F

2013-12-01

Nonalcoholic fatty liver disease (NAFLD) is linked with insulin resistance, however, if it is differentially associated with surrogate hepatic insulin resistance indexes is still undefined. We examined the relationship between these indexes, NAFLD and its related biomarkers (alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyltransferase [GGT], alkaline phosphatase [ALK], high-sensitive C reactive protein [hsCRP], insulin-like growth factor-1 [IGF-1]). 473 Caucasians subjects underwent liver ultrasonography and oral glucose tolerance tests; homeostasis model assessment (HOMA), glucose(0-30) (area under the curve [AUC]) × insulin(0-30) (AUC) and liver insulin resistance (liver IR) indexes were computed. Liver IR index correlated more strongly than HOMA with GGT, ALK, hsCRP, ALT and AST and more strongly than glucose(0-30) (AUC) × insulin(0-30) (AUC) index with ALT, AST, GGT, ALK, hsCRP, and IGF-1. The ability of these indexes to identify NAFLD was evaluated by the area under the ROC curve; the ROC AUC for liver IR index was higher (0.733) than the ones for HOMA (0.685) and glucose(0-30) (AUC) × insulin(0-30) (AUC) (0.663) indexes. In a logistic regression model subjects in the highest quartile of the three indexes had a higher risk of having NAFLD than those in the lowest quartile (9.85-, 5.12- or 3.99-fold higher for liver IR index, HOMA, glucose(0-30) (AUC) × insulin(0-30) (AUC) index respectively). we documented significant cross-sectional associations of NAFLD and liver biomarkers with three validated indexes of hepatic insulin resistance, with liver IR index showing the stronger correlation. © 2013 Elsevier B.V. All rights reserved.

Persistence of the benefit of an antioxidant therapy in children and teenagers with Down syndrome.

PubMed

Parisotto, Eduardo Benedetti; Giaretta, Andréia Gonçalves; Zamoner, Ariane; Moreira, Emilia Addison Machado; Fröde, Tânia Silvia; Pedrosa, Rozangela Curi; Filho, Danilo Wilhelm

2015-01-01

This study examined the effect of an antioxidant intervention in biomarkers of inflammation and oxidative stress (OS) in the blood of Down syndrome (DS) children and teenagers during four different stages. A control group was composed by healthy children (n=18), assessed once, and a Down group composed by DS patients (n=21) assessed at the basal period (t0), as well as after 6 months of antioxidant supplementation (t1), after 12 months (after interruption of the antioxidant intervention for 6 months) (t2), and again after further 6 months of antioxidant supplementation (t3). Biomarkers of inflammation (myeloperoxidase activity - MPO and levels of IL-1β and TNF-α) and OS (thiobarbituric acid reactive substances - TBARS, protein carbonyls - PC), reduced glutathione (GSH), uric acid (UA) and vitamin E levels, as well as antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and gamma-glutamyltransferase (GGT) activities, were measured after each period. After the antioxidant supplementation, the activities of SOD, CAT, GPx, GR, GGT and MPO were downregulated, while TBARS contents were strongly decreased, the contents of GSH and vitamin E were significantly increased, and no changes in G6PD and GST activity as well as in UA and PC levels were detected. After the interruption of the antioxidant therapy for 6 months, DS patients showed elevated GPx and GGT activities and also elevated UA and TBARS levels. No changes in SOD, CAT, GR, GST, G6PD and MPO activities as well as in GSH, vitamin E, PC, TNF-α and IL-1β levels were detected. The results showed that the antioxidant intervention persistently attenuated the systemic oxidative damage in DS patients even after a relatively long period of cessation of the antioxidant intervention. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lipid profile and thyroid hormone concentrations in children with epilepsy treated with oxcarbazepine monotherapy: a prospective long-term study.

PubMed

Garoufi, A; Koemtzidou, E; Katsarou, E; Dinopoulos, A; Kalimeraki, I; Fotinou, A; Drakatos, A; Attilakos, A

2014-01-01

To evaluate prospectively the changes and possible associations in lipid and thyroid profiles in children treated with oxcarbazepine (OXC) monotherapy. Serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), lipoprotein (a) [Lp(a)], free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH) and gamma-glutamyltransferase (GGT) concentrations were measured in 23 children with epilepsy, before and at 8 and 18 months of OXC monotherapy. Total cholesterol was significantly increased at 8 months (P = 0.033), whereas LDL-C was significantly increased at 8 and 18 months (P < 0.001 and P = 0.004, respectively) of treatment. Lp(a) was significantly increased at 8 months (P = 0.042) and borderline significantly increased at 18 months (P = 0.050) of treatment. FT4 was significantly decreased at 8 and 18 months (P < 0.001 and P = 0.002, respectively), and TSH levels were significantly increased at 8 and 18 months (P = 0.002 and P = 0.001, respectively) of OXC monotherapy. GGT levels were significantly increased at 8 and 18 months (P < 0.001) of treatment. There were no significant alterations in HDL-C, TGs and FT3 levels during the study. Significant positive correlations were found between GGT and LDL-C levels at 8 (r = 0.468, P = 0.024) and 18 months (r = 0.498, P = 0.016), and between TSH and TC at 18 months (r = 0.508, P = 0.013) of treatment. OXC monotherapy may cause significant and persistent alterations in lipid and thyroid profiles in children with epilepsy. The increase in LDL-C and TC levels may be associated with liver enzymes induction and thyroid dysfunction. Further long-term prospective studies are required to confirm these findings and to determine their clinical significance. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Relationship between obstructive sleep apnea and liver abnormalities in morbidly obese patients: a prospective study.

PubMed

Jouët, Pauline; Sabaté, Jean-Marc; Maillard, Dominique; Msika, Simon; Mechler, Charlotte; Ledoux, Séverine; Harnois, Florence; Coffin, Benoit

2007-04-01

Morbid obesity is a risk factor of nonalcoholic steatohepatitis (NASH). Obstructive sleep apnea (OSA) could also be an independent risk factor for elevated liver enzymes and NASH. The relationships between liver injuries and OSA in morbidly obese patients requiring bariatric surgery were studied prospectively. Every consecutive morbidly obese patient (BMI > or =40 kg/m2 or > or =35 kg/m2 with severe comorbidities) requiring bariatric surgery was included between January 2003 and October 2004. Polygraphic recording, serum aminotransferases (ALT, AST), gamma-glutamyltransferase (GGT) and liver biopsy were systematically performed. OSA was present when the apnea-hypopnea index (AHI) was >10/h. 62 patients (54 F; age 38.5 +/- 11.0 (SD) yrs; BMI 47.8 +/- 8.4 kg/m2) were included. Liver enzymes (AST, ALT or GGT) were increased in 46.6%. NASH was present in 34.4% and OSA in 84.7%. Patients with OSA were significantly older (P = 0.015) and had a higher BMI (P = 0.003). In multivariate analysis, risk factors for elevated liver enzymes were the presence of OSA and male sex. The presence of NASH was similar in patients with or without OSA (32.7% vs 44.4% of patients, P = 0.76). In this cohort of morbidly obese patients requiring bariatric surgery, one-third of patients had NASH, a prevalence similar to previous studies. OSA was found to be a risk factor for elevated liver enzymes but not for NASH.

Hepatic lipidosis in llamas and alpacas: 31 cases (1991-1997).

PubMed

Tornquist, S J; Van Saun, R J; Smith, B B; Cebra, C K; Snyder, S P

1999-05-01

To identify factors associated with hepatic lipidosis (HL) in llamas and alpacas. Retrospective case series. 30 llamas and 1 alpaca. Medical records were searched to identify llamas or alpacas in which a histologic diagnosis of HL was made. Information was retrieved on signalment, history, clinical and laboratory findings, and results of necropsy or examination of biopsy specimens. Data were analyzed using descriptive statistics and chi 2 analyses. Females were affected more often than males; however, the sex distribution was not different from that of the camelid population in the diagnostic laboratory's database. Fifty-four percent of the females were pregnant, and 46% were lactating. Most affected camelids were 6 to 10 years old. Anorexia and recent weight loss were common (51.6% of camelids). An infective agent was found in only one ilama, and toxins and mineral deficiencies were not identified. The most common abnormalities on serum biochemical analysis were a high concentration of bile acids, high activities of gamma-glutamyltransferase (GGT) and aspartate aminotransferase (AST), and hypoproteinemia. Concentrations of nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (beta-HB) were high in those camelids in which these compounds were assayed. Twenty-nine camelids did not survive. Sick camelids should be considered at risk for developing HL, especially those with anorexia or the metabolic demands of pregnancy and lactation. Other stresses also appear to contribute. High concentrations of NEFA, beta-HB, and bile acids; high activities of GGT and AST; and hypoproteinemia may indicate that HL has developed.

Simpler score of routine laboratory tests predicts liver fibrosis in patients with chronic hepatitis B.

PubMed

Zhou, Kun; Gao, Chun-Fang; Zhao, Yun-Peng; Liu, Hai-Lin; Zheng, Rui-Dan; Xian, Jian-Chun; Xu, Hong-Tao; Mao, Yi-Min; Zeng, Min-De; Lu, Lun-Gen

2010-09-01

In recent years, a great interest has been dedicated to the development of noninvasive predictive models to substitute liver biopsy for fibrosis assessment and follow-up. Our aim was to provide a simpler model consisting of routine laboratory markers for predicting liver fibrosis in patients chronically infected with hepatitis B virus (HBV) in order to optimize their clinical management. Liver fibrosis was staged in 386 chronic HBV carriers who underwent liver biopsy and routine laboratory testing. Correlations between routine laboratory markers and fibrosis stage were statistically assessed. After logistic regression analysis, a novel predictive model was constructed. This S index was validated in an independent cohort of 146 chronic HBV carriers in comparison to the SLFG model, Fibrometer, Hepascore, Hui model, Forns score and APRI using receiver operating characteristic (ROC) curves. The diagnostic values of each marker panels were better than single routine laboratory markers. The S index consisting of gamma-glutamyltransferase (GGT), platelets (PLT) and albumin (ALB) (S-index: 1000 x GGT/(PLT x ALB(2))) had a higher diagnostic accuracy in predicting degree of fibrosis than any other mathematical model tested. The areas under the ROC curves (AUROC) were 0.812 and 0.890 for predicting significant fibrosis and cirrhosis in the validation cohort, respectively. The S index, a simpler mathematical model consisting of routine laboratory markers predicts significant fibrosis and cirrhosis in patients with chronic HBV infection with a high degree of accuracy, potentially decreasing the need for liver biopsy.

Renal effects of carprofen administered to healthy dogs anesthetized with propofol and isoflurane.

PubMed

Ko, J C; Miyabiyashi, T; Mandsager, R E; Heaton-Jones, T G; Mauragis, D F

2000-08-01

To evaluate renal effects of carprofen in healthy dogs following general anesthesia. Randomized clinical trial. 10 English hound dogs (6 females and 4 males). Dogs were randomly assigned to control (n = 5) or carprofen (5) groups. Anesthesia was induced with propofol (6 to 8 mg/kg [2.7 to 3.6 mg/lb] of body weight, i.v.) and maintained with isoflurane (end-tidal concentration, 2.0%). Each dog underwent two 60-minute anesthetic episodes with 1 week between episodes, and mean arterial blood pressure was maintained between 60 and 90 mm Hg during each episode. Dogs in the carprofen group received carprofen (2.2 mg/kg [1 mg/lb], p.o.) at 9:00 AM and 6:00 PM the day before and at 7:00 AM the day of the second anesthetic episode. Glomerular filtration rates (GFR) were determined during each anesthetic episode by use of renal scintigraphy. Serum creatinine and BUN concentrations and the urine gamma-glutamyltransferase-to-creatinine concentration (urine GGT:creatinine) ratio were determined daily for 2 days before and 5 days after general anesthesia. Significant differences were not detected in BUN and serum creatinine concentrations, urine GGT:creatinine ratio, and GFR either between or within treatment groups over time. Carprofen did not significantly alter renal function in healthy dogs anesthetized with propofol and isoflurane. These results suggest that carprofen may be safe to use for preemptive perioperative analgesia, provided that normal cardiorespiratory function is maintained.

The effects of Crataegus aronia var. dentata Browicz extract on biochemical indices and apoptosis in partially hepatectomized liver in rats

PubMed Central

Keskin, Nazan; Mammadov, Ramazan; Ili, Pinar

2012-01-01

Crataegus species have been widely used in herbal medicine, especially for the hearth diseases. In the present study, the effect of Crataegus aronia var. dentata Browicz extract on partially hepatectomized rats was investigated with biochemical and TUNEL apoptosis assays. The extracts of the plant at the concentrations of 0.5 and 1 ml/100 g body weight/day were administered orally to the two experimental groups including partially hepatectomized rats for 42 days. At the end of the experimental period, animals were sacrificed, blood was collected for the assessment of serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), and the liver tissue was used for TUNEL assay. In biochemical assay, it was found a significant decrease in the levels of serum ALT and AST in the experimental groups. On the other hand, the plant extract did not cause any significant changes in the level of GGT in these groups. In apoptosis assay, TUNEL positive hepatocytes could not be detected in both experimental groups. The present findings can suggest that Crataegus aronia var. dentata Browicz extract can decrease the levels of serum ALT and AST and play a role in apoptosis of hepatocytes in the liver of partially hepatectomized rats. However, further studies are required to confirm the effects of the plant extract on hepatoprotection and apoptosis in the regenerating liver after partial hepatectomy in animal models. PMID:22938545

Preclinical Evaluation of a Potential GSH Ester Based PET/SPECT Imaging Probe DT(GSHMe)₂ to Detect Gamma Glutamyl Transferase Over Expressing Tumors.

PubMed

Khurana, Harleen; Meena, Virendra Kumar; Prakash, Surbhi; Chuttani, Krishna; Chadha, Nidhi; Jaswal, Ambika; Dhawan, Devinder Kumar; Mishra, Anil Kumar; Hazari, Puja Panwar

2015-01-01

Gamma Glutamyl Transferase (GGT) is an important biomarker in malignant cancers. The redox processes ensuing from GGT-mediated metabolism of extracellular GSH are implicated in critical aspects of tumor cell biology. Reportedly, Glutathione monoethyl ester (GSHMe) is a substrate of GGT, which has been used for its rapid transport over glutathione. Exploring GGT to be an important target, a homobivalent peptide system, DT(GSHMe)2 was designed to target GGT-over expressing tumors for diagnostic purposes. DT(GSHMe)2 was synthesized, characterized and preclinically evaluated in vitro using toxicity, cell binding assays and time dependent experiments. Stable and defined radiochemistry with 99mTc and 68Ga was optimized for high radiochemical yield. In vivo biodistribution studies were conducted for different time points along with scintigraphic studies of radiolabeled DT(GSHMe)2 on xenografted tumor models. For further validation, in silico docking studies were performed on GGT (hGGT1, P19440). Preclinical in vitro evaluations on cell lines suggested minimal toxicity of DT(GSHMe)2 at 100 μM concentration. Kinetic analysis revealed transport of 99mTc-DT(GSHMe)2 occurs via a saturable high-affinity carrier with Michaelis constant (Km) of 2.25 μM and maximal transport rate velocity (Vmax) of 0.478 μM/min. Quantitative estimation of GGT expression from western blot experiments showed substantial expression with 41.6 ± 7.07 % IDV for tumor. Small animal micro PET (Positron Emission Tomography)/CT(Computed Tomography) coregistered images depicted significantly high uptake of DT(GSHMe)2 at the BMG-1 tumor site. ROI analysis showed high tumor to contra lateral muscle ratio of 9.33 in PET imaging studies. Avid accumulation of radiotracer was observed at tumor versus inflammation site at 2 h post i.v. injection in an Ehrlich Ascites tumor (EAT) mice model, showing evident specificity for tumor. We propose DT(GSHMe)2 to be an excellent candidate for prognostication and tumor

Gamma-glutamyl transpeptidase (GGT) blood test

MedlinePlus

... test is used to detect diseases of the liver or bile ducts. It is also done with other tests (such ... and bilirubin tests) to tell the difference between liver or bile duct disorders and bone disease. It may also be ...

Serum gamma-glutamyl transferase activity is an independent predictor for cardiovascular disease in obstructive sleep apnea syndrome.

PubMed

Kanbay, Asiye; Kaya, Elif; Buyukoglan, Hakan; Ozdogan, Nezihe; Kaya, Mehmet Gungor; Oymak, Fatma Sema; Gulmez, Inci; Demir, Ramazan; Kokturk, Oguz

2011-04-01

Gamma glutamyl transferase (GGT) is a new marker for predicting myocardial infarction, stroke, cardiac death and inflammation. There is also a strong relationship between Obstructive Sleep Apnea Syndrome (OSAS) and cardiovascular disease. This study was designed to investigate the association between serum GGT levels and cardiovascular disease in patients with OSAS, and relationship between severity of OSAS and serum GGT level. We evaluated the medical records of 166 subjects who were admitted for sleep study. OSAS was diagnosed by polysomnography if Apnea-Hypopnea Index (AHI) > 5. According to AHI, individuals in whom AHI< 5 were recruited as group 1 (OSAS negative group), AHI = 5-15: group 2 (mild OSAS group), AHI = 15-30: group 3 (moderate OSAS group), AHI >30: group 4 (severe OSAS group). Cardiovascular disease was defined if the patients had heart failure, coronary artery disease or arrhythmia. Of the subjects, 112 (67.5%) were male and the mean age was 54.3 ± 12.2 years. There were 22 patients (13.2%), 17 patients (10.2%), 34 patients (20.4%) and 93 patients (56.2%) in group 1, 2, 3 and 4, respectively. There is a significant increase in serum GGT levels while AHI score increases (group 1 = 28.0 ± 10.1, group 2 = 33.8 ± 13.2, group 3 = 35.2 ± 8.5, group 4 = 40.0 ± 22.0; p for trend = 0.024). However, serum C-reactive protein (CRP), alanine aminotransferase and aspartate aminotransferase levels were similar in all groups (p > 0.05). There was a significant independent association between serum GGT levels and the severity of OSAS. Moreover, serum GGT levels were significantly high in patients with cardiovascular disease compared with patients without cardiovascular disease in severe-moderate-mild OSAS (p < 0.05) and OSAS negative groups while CRP levels were not. This was a significant independent association. The present study suggests that high serum GGT level, regardless of the other traditional risk factors, is an independent predictor of

Efficacy and safety of fermented garlic extract on hepatic function in adults with elevated serum gamma-glutamyl transpeptidase levels: a double-blind, randomized, placebo-controlled trial.

PubMed

Kim, Ha-Na; Kang, Sung-Goo; Roh, Yong Kyun; Choi, Min-Kyu; Song, Sang-Wook

2017-08-01

Alcoholic liver disease or non-alcoholic fatty liver disease/non-alcoholic steatohepatitis are well-known risk factors for liver fibrosis or cirrhosis and hepatocellular carcinoma; it is a major global health concern, but there are few effective and safe management options. Therefore, we aimed to investigate the effects of fermented garlic extracts (FGEs) on hepatic function in adults with mild hepatic dysfunction without underlying hepatic disease. In this double-blind, randomized, placebo-controlled study, seventy-five adults with elevated serum gamma-glutamyl transpeptidase (GGT) levels were included in a FGE-administered group (n = 36) or a placebo group (n = 39), and received either two sachets/day containing FGEs or placebo over a 12-week period. Primary endpoint was the change in serum GGT levels. Data were analysed using a generalized linear mixed effects model. Significant group × time interactions for serum levels of GGT (F = 3.98, P = 0.022) and alanine aminotransferase (ALT; F = 3.28, P = 0.043) were observed with an improvement in levels of GGT (P = 0.066) and ALT (P = 0.014) in the FGE group compared to that reported for the placebo group at the 12-week visits. There was no intergroup difference in the prevalence of adverse events. Intake of FGEs improved serum GGT and ALT levels in adults with mildly elevated serum GGT level without reported adverse side effects. FGEs might be effective and safe management options for mild hepatic dysfunction.

Proteomic identification of Drosophila melanogaster male accessory gland proteins, including a pro-cathepsin and a soluble gamma-glutamyl transpeptidase.

PubMed

Walker, Michael J; Rylett, Caroline M; Keen, Jeff N; Audsley, Neil; Sajid, Mohammed; Shirras, Alan D; Isaac, R Elwyn

2006-05-02

In Drosophila melanogaster, the male seminal fluid contains proteins that are important for reproductive success. Many of these proteins are synthesised by the male accessory glands and are secreted into the accessory gland lumen, where they are stored until required. Previous studies on the identification of Drosophila accessory gland products have largely focused on characterisation of male-specific accessory gland cDNAs from D. melanogaster and, more recently, Drosophila simulans. In the present study, we have used a proteomics approach without any sex bias to identify proteins in D. melanogaster accessory gland secretions. Thirteen secreted accessory gland proteins, including seven new accessory gland proteins, were identified by 2D-gel electrophoresis combined with mass spectrometry of tryptic fragments. They included protein-folding and stress-response proteins, a hormone, a lipase, a serpin, a cysteine-rich protein and two peptidases, a pro-enzyme form of a cathepsin K-like cysteine peptidase and a gamma-glutamyl transpeptidase. Enzymatic studies established that accessory gland secretions contain a cysteine peptidase zymogen that can be activated at low pH. This peptidase may have a role in the processing of female and other male-derived proteins, but is unlikely to be involved in the processing of the sex peptide. gamma-Glutamyl transpeptidases are type II integral membrane proteins; however, the identified AG gamma-glutamyl transpeptidase (GGT-1) is unusual in that it is predicted to be a soluble secreted protein, a prediction that is supported by biochemical evidence. GGT-1 is possibly involved in maintaining a protective redox environment for sperm. The strong gamma-glutamyl transpeptidase activity found in the secretions provides an explanation for the observation that glutamic acid is the most abundant free amino acid in accessory gland secretions of D. melanogaster. We have applied biochemical approaches, not used previously, to characterise

Evaluation of adverse effects of long-term orally administered carprofen in dogs.

PubMed

Raekallio, Marja R; Hielm-Björkman, Anna K; Kejonen, Johanna; Salonen, Hanna M; Sankari, Satu M

2006-03-15

To evaluate the adverse effects of carprofen in dogs after oral administration for 2 months. Prospective, randomized, blinded, placebo-controlled clinical trial. 22 dogs with osteoarthritis in the hip or elbow joint. 13 dogs received orally administered carprofen daily for 2 months, and 9 dogs received a placebo for 2 months. Dogs were weighed, and serum and urine samples were collected before initiation of treatment and 4 and 8 weeks after initiation of treatment. Serum concentrations of total protein, albumin, urea, and creatinine and serum activities of alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were measured. Urinary ALP-to-creatinine, gamma-glutamyltransferase (GGT)-to-creatinine, and protein-to-creatinine ratios were calculated. Dogs were observed by owners for adverse effects. Serum protein and albumin concentrations were lower in treated dogs than in those that received placebo at 4 weeks, but not at 8 weeks. No changes were observed in serum urea or creatinine concentrations; ALP or ALT activity; or urinary ALP-to-creatinine, GGT-to-creatinine, or protein-to-creatinine ratios. Dogs' weights did not change. Severity of vomiting, diarrhea, and skin reactions did not differ between groups, but appetite was better in dogs receiving carprofen than in dogs in the placebo group. It is possible that the transient decreases in serum protein and albumin concentrations in dogs that received carprofen were caused by altered mucosal permeability of the gastrointestinal tract because no indications of renal or hepatic toxicity were observed. Carprofen appeared to be well tolerated by dogs after 2 months of administration.

The effect of lead poisoning on hematologic and biochemical values in trumpeter swans and Canada geese.

PubMed

Katavolos, P; Staempfli, S; Sears, W; Gancz, A Y; Smith, D A; Bienzle, D

2007-12-01

Lead is a persistent contaminant in the environment, and waterfowl are susceptible to lead toxicity from ingestion of lead pellets and fishing weights. Lead affects numerous physiologic processes through inhibition of enzyme activity and protein function, but its effects on commonly assessed avian blood values are incompletely understood. Our aim was to evaluate hematologic and biochemical changes associated with blood lead concentrations in trumpeter swans and Canada geese. Data for CBCs, plasma biochemical profiles (total protein, albumin, glucose, cholesterol, total bilirubin, calcium, phosphorus, gamma-glutamyltransferase [GGT], aspartate aminotransferase, lactate dehydrogenase, glutamate dehydrogenase, creatine kinase, amylase, and lipase), and whole blood lead concentrations were retrospectively analyzed for 69 trumpeter swans and 52 Canada geese. Laboratory data obtained prospectively from an additional 20 trumpeter swans also were included. RBC morphology was semiquantitated in blood smears from 70 of the birds. Data were analyzed initially by ANOVA and covariance. A statistical model then was constructed to determine the relationship between each parameter and lead concentration. In both avian species, PCV, hemoglobin concentration, and MCHC decreased significantly (P < .05) with increasing blood lead concentration. Uric acid concentration and GGT activity were increased in trumpeter swans and phosphorus concentration was decreased in Canada geese in association with high blood lead concentration (P < .05). Lead toxicosis induced significant changes in the values of commonly measured hematologic parameters in waterfowl. These changes may be useful indicators of severe lead intoxication during routine laboratory assessment. Changes in clinical chemistry values, although statistically significant, were too inconsistent to serve as indicators of lead toxicosis.

Biochemical, anthropometric and body composition indicators as predictors of hepatic steatosis in obese adolescents

PubMed Central

Gobato, Amanda Oliva; Vasques, Ana Carolina J.; Yamada, Roberto Massao; Zambon, Mariana Porto; Barros-Filho, Antonio de Azevedo; Hessel, Gabriel

2014-01-01

OBJECTIVE: To describe the prevalence of hepatic steatosis and to assess the performance of biochemical, anthropometric and body composition indicators for hepatic steatosis in obese teenagers. METHODS: Cross-sectional study including 79 adolecents aged from ten to 18 years old. Hepatic steatosis was diagnosed by abdominal ultrasound in case of moderate or intense hepatorenal contrast and/or a difference in the histogram ≥7 on the right kidney cortex. The insulin resistance was determined by the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) index for values >3.16. Anthropometric and body composition indicators consisted of body mass index, body fat percentage, abdominal circumference and subcutaneous fat. Fasting glycemia and insulin, lipid profile and hepatic enzymes, such as aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase and alkaline phosphatase, were also evaluated. In order to assess the performance of these indicators in the diagnosis of hepatic steatosis in teenagers, a ROC curve analysis was applied. RESULTS: Hepatic steatosis was found in 20% of the patients and insulin resistance, in 29%. Gamma-glutamyltransferase and HOMA-IR were good indicators for predicting hepatic steatosis, with a cutoff of 1.06 times above the reference value for gamma-glutamyltransferase and 3.28 times for the HOMA-IR. The anthropometric indicators, the body fat percentage, the lipid profile, the glycemia and the aspartate aminotransferase did not present significant associations. CONCLUSIONS: Patients with high gamma-glutamyltransferase level and/or HOMA-IR should be submitted to abdominal ultrasound examination due to the increased chance of having hepatic steatosis. PMID:25119755

The association of nonalcoholic fatty liver disease with central and peripheral blood pressure in adolescence: findings from a cross-sectional study

PubMed Central

Patel, Sumaiya; Lawlor, Debbie A.; Ferreira, Diana L.S.; Hughes, Alun D.; Chaturvedi, Nish; Callaway, Mark; Day, Chris; Sattar, Naveed; Fraser, Abigail

2015-01-01

Objectives: We aimed to determine the association of nonalcoholic fatty liver disease (NAFLD) with central and peripheral blood pressure (BP), in a general adolescent population and to examine whether associations are independent of adiposity. Methods: Using cross-sectional data from a subsample (N = 1904) of a UK birth cohort, we assessed markers of NAFLD including ultrasound scan (USS) determined fatty liver, shear velocity (marker of liver fibrosis), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) at a mean age of 17.8 years. These were related to BP [central and peripheral SBP and DBP and mean arterial pressure (MAP)]. Results: Fatty liver was positively associated with central and peripheral SBP, DBP and MAP in models adjusting for age, sex, social class, puberty and alcohol intake. These positive associations were attenuated to the null when fat mass was included. For example, in confounder-adjusted models, not including fat mass, mean central SBP was 3.74 mmHg [95% confidence interval (CI) 1.12 to 6.36] higher in adolescents with USS fatty liver than in those without; with additional adjustment for fat mass, the association attenuated to the null value (−0.37 mmHg; 95% CI –3.09 to 2.36). Similar patterns were found for associations of ALT and GGT with central and peripheral BP. There was no consistent evidence of associations of shear velocity or AST with BP measurements. Fatty liver was not consistently associated with central pulse pressure (PP), peripheral PP and Aix@75. Conclusion: NAFLD is not associated with higher central or peripheral BP in adolescents once confounding by adiposity is taken into account. PMID:25426570

Longitudinal Changes in Serum Levels of Angiopoietin-Like Protein 6 and Selenoprotein P After Gastric Bypass Surgery.

PubMed

Lim, Jisun; Park, Hye Soon; Lee, Seul Ki; Jang, Yeon Jin; Lee, Yeon Ji; Heo, Yoonseok

2016-04-01

Bariatric surgery has beneficial effects on weight loss and metabolic profiles. Recent evidence suggests that liver-derived hepatokines play a role in the pathophysiology of metabolic diseases. However, few studies have reported longitudinal changes in hepatokines after gastric bypass surgery. We investigated changes in the serum levels of angiopoietin-like protein 6 (Angptl6) and selenoprotein P after gastric bypass surgery. We followed 10 patients who were treated with gastric bypass for weight loss. We measured metabolic parameters and the serum levels of Angptl6 and selenoprotein P before, 1 month after, and 9 months after surgery. We investigated the changes in those hepatokines after surgery and the associations between changes in Angptl6 and selenoprotein P, respectively, and metabolic parameters. Body mass index decreased linearly. Levels of hemoglobin A1c (HbA1c), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), total cholesterol, triglyceride, LDL cholesterol, and Angptl6 were significantly lower 1 and 9 months after surgery. Fasting plasma glucose was normal throughout the study. Fasting insulin decreased 1 month after surgery but increased 9 months post-surgery. Levels of selenoprotein P increased linearly. Significant correlations were detected between the levels of Angptl6 and LDL cholesterol and fasting insulin. Changes in Angptl6 levels were significantly correlated with changes in total cholesterol and LDL cholesterol. Selenoprotein P levels were inversely correlated with GGT, and changes in selenoprotein P were inversely correlated with changes in homeostasis model assessment for insulin resistance (HOMA-IR). Our results suggest that gastric bypass may alter the serum levels of hepatokines independent of weight loss, and these changes are related to certain hepatic metabolic changes.

Gemtuzumab ozogamicin-induced sinusoidal obstructive syndrome treated with defibrotide: a case report.

PubMed

Lannoy, D; Decaudin, B; Grozieux de Laguérenne, A; Barrier, F; Pignon, J M; Wetterwald, M; Odou, P

2006-08-01

New treatments for relapse of acute myeloid leukaemia (AML), include gemtuzumab ozogamicin (GO), an anti-CD33 monoclonal antibody. We describe a second case of GO-induced sinusoidal obstructive syndrome (SOS) effectively treated with defibrotide (DF). No stem-cell transplantation was involved. On day 23 after the first GO dose, a patient presented with ascites, weight gain, liver enlargement and pain in the right upper quadrant. Sudden hepatic cytolysis (transaminases at six times the normal range: grade 3) and cholestasis [alkaline phosphatase ALP and gamma-glutamyltransferase (GGT) respectively at four and eight times the normal range: grade 2] were observed but there was no evidence of increase serum bilirubin. Treatment with DF (Prociclide), Crinos; 10 mg/kg/day, or 200 mg, q.i.d.) improved the hepatic abnormality within a few days (serum transaminases decreased from 312 to 103 IU/L for aspartate aminotransferase (AST) and from 141 to 80 IU/L for alanine aminotransferase (ALT) within 3 days ALP increased from 253 to 383 IU/L and gamma-GT from 238 to 417 IU/L 4 days after administration of DF. The clinical and biological features of our case suggest a direct involvement of GO in causing SOS, even when used as monotherapy, without allogenic stem-cell transplantation. Low dose DF (10 mg/kg/day) given early during the development of SOS associated with GO was effective. Unfortunately, in our case the patient eventually died of multi-organ failure probably because of failure of GO.

Metabolic Syndrome and Serum Liver Enzymes Level at Patients with Type 2 Diabetes Mellitus

PubMed Central

Music, Miralem; Dervisevic, Amela; Pepic, Esad; Lepara, Orhan; Fajkic, Almir; Ascic-Buturovic, Belma; Tuna, Enes

2015-01-01

Objectives: The aim of this study was to evaluate liver function in patients with type 2 diabetes mellitus (T2DM) with and without metabolic syndrome (MS) by determining serum levels of gamma glutamyltransferase (GGT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We also investigated correlation between levels of liver enzymes and some components of MS in both groups of patients. Methods: This cross-sectional study included 96 patients (age 47–83 years) with T2DM. All patients were divided according to the criteria of the National Cholesterol Education Program (NCEP) in two groups: 50 patients with T2 DM and MS (T2DM-MS) and 46 patients with T2DM without MS (T2DM-Non MS). The analysis included blood pressure monitoring and laboratory tests: fasting blood glucose (FBG), total lipoprotein cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fibrinogen and liver enzymes: GGT, ALT and AST. T2DM-MS group included patients which had FBG ≥ 6,1 mmol/L, TG ≥ 1,7 mmol/L and blood pressure ≥ 130/85 mm Hg. Results: T2DM-MS patients had significant higher values of systolic blood pressure, diastolic blood pressure and medium arterial pressure compared to T2DM-Non MS patients. Serum levels of TC, TG, LDL-C, VLDL-C and FBG were significantly higher in the T2DM-MS group compared to the T2DM-Non MS group. Serum fibrinogen level and GGT level were significantly higher in patients with T2DM-MS compared to the serum fibrinogen level and GGT level in T2DM-Non MS patients. Mean serum AST and ALT level were higher, but not significantly, in patients with T2DM and MS compared to the patients with T2DM without MS. Significant negative correlations were observed between TC and AST (r= -0,28, p<0,05), as well as between TC and ALT level (r= -0,29, p<0,05) in T2DM-MS group of patients. Conclusion: These results suggest that patients with T2DM and MS have markedly elevated liver enzymes. T2DM and MS probably play a role in

Structure of 6-diazo-5-oxo-norleucine-bound human gamma-glutamyl transpeptidase 1, a novel mechanism of inactivation

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

Terzyan, Simon S.; Cook, Paul F.; Heroux, Annie

Intense efforts are underway to identify inhibitors of the enzyme gamma–glutamyl transpeptidase 1 (GGT1) which cleaves extracellular gamma–glutamyl compounds and contributes to the pathology of asthma, reperfusion injury and cancer. The glutamate analog, 6–diazo–5–oxo–norleucine (DON), inhibits GGT1. DON also inhibits many essential glutamine metabolizing enzymes rendering it too toxic for use in the clinic as a GGT1 inhibitor. We investigated the molecular mechanism of human GGT1 (hGGT1) inhibition by DON to determine possible strategies for increasing its specificity for hGGT1. DON is an irreversible inhibitor of hGGT1. The second order rate constant of inactivation was 0.052 m M –1 minmore » –1 and the K i was 2.7 ± 0.7 m M. The crystal structure of DON–inactivated hGGT1 contained a molecule of DON without the diazo–nitrogen atoms in the active site. The overall structure of the hGGT1–DON complex resembled the structure of the apo–enzyme; however, shifts were detected in the loop forming the oxyanion hole and elements of the main chain that form the entrance to the active site. The structure of hGGT1–DON complex revealed two covalent bonds between the enzyme and inhibitor which were part of a six membered ring. The ring included the OG atom of Thr381, the reactive nucleophile of hGGT1 and the α–amine of Thr381. As a result, the structure of DON–bound hGGT1 has led to the discovery of a new mechanism of inactivation by DON that differs from its inactivation of other glutamine metabolizing enzymes, and insight into the activation of the catalytic nucleophile that initiates the hGGT1 reaction.« less

Structure of 6-diazo-5-oxo-norleucine-bound human gamma-glutamyl transpeptidase 1, a novel mechanism of inactivation

DOE PAGES

Terzyan, Simon S.; Cook, Paul F.; Heroux, Annie; ...

2017-04-05

Intense efforts are underway to identify inhibitors of the enzyme gamma–glutamyl transpeptidase 1 (GGT1) which cleaves extracellular gamma–glutamyl compounds and contributes to the pathology of asthma, reperfusion injury and cancer. The glutamate analog, 6–diazo–5–oxo–norleucine (DON), inhibits GGT1. DON also inhibits many essential glutamine metabolizing enzymes rendering it too toxic for use in the clinic as a GGT1 inhibitor. We investigated the molecular mechanism of human GGT1 (hGGT1) inhibition by DON to determine possible strategies for increasing its specificity for hGGT1. DON is an irreversible inhibitor of hGGT1. The second order rate constant of inactivation was 0.052 m M –1 minmore » –1 and the K i was 2.7 ± 0.7 m M. The crystal structure of DON–inactivated hGGT1 contained a molecule of DON without the diazo–nitrogen atoms in the active site. The overall structure of the hGGT1–DON complex resembled the structure of the apo–enzyme; however, shifts were detected in the loop forming the oxyanion hole and elements of the main chain that form the entrance to the active site. The structure of hGGT1–DON complex revealed two covalent bonds between the enzyme and inhibitor which were part of a six membered ring. The ring included the OG atom of Thr381, the reactive nucleophile of hGGT1 and the α–amine of Thr381. As a result, the structure of DON–bound hGGT1 has led to the discovery of a new mechanism of inactivation by DON that differs from its inactivation of other glutamine metabolizing enzymes, and insight into the activation of the catalytic nucleophile that initiates the hGGT1 reaction.« less

Hepatoprotective effect of manganese chloride against CCl4-induced liver injury in rats.

PubMed

Eidi, Akram; Mortazavi, Pejman; Behzadi, Khodabakhsh; Rohani, Ali Haeri; Safi, Shahabeddin

2013-11-01

The aim of the present study is to evaluate the protective effect of manganese chloride against carbon tetrachloride (CCl4)-induced liver injury in rats. Manganese chloride (0.001, 0.01, 0.05 and 0.1 g/kg bw) was administered intragastrically for 28 consecutive days to male CCl4-treated rats. The hepatoprotective activity was assessed using various biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT) and superoxide dismutase (SOD). Histopathological changes in the liver of different groups were also studied. Administration of CCl4 increased the serum ALT, AST, ALP and GGT but decreased SOD levels in rats. Treatment with manganese chloride significantly attenuated these changes to nearly normal levels. The animals treated with manganese chloride have shown decreased necrotic zones and hepatocellular degeneration when compared to the liver exposed to CCl4 intoxication alone. Thus, the histopathological studies also supported the protective effect of manganese chloride. Therefore, the results of this study suggest that manganese chloride exerts hepatoprotection via promoting antioxidative properties against CCl4-induced oxidative liver damage.

Insulin-induced inhibition of gluconeogenesis genes, including glutamic pyruvic transaminase 2, is associated with reduced histone acetylation in a human liver cell line.

PubMed

Honma, Kazue; Kamikubo, Michiko; Mochizuki, Kazuki; Goda, Toshinao

2017-06-01

Hepatic glutamic pyruvic transaminase (GPT; also known as alanine aminotransferase) is a gluconeogenesis enzyme that catalyzes conversions between alanine and pyruvic acid. It is also used as a blood biomarker for hepatic damage. In this study, we investigated whether insulin regulates GPT expression, as it does for other gluconeogenesis genes, and if this involves the epigenetic modification of histone acetylation. Human liver-derived HepG2 cells were cultured with 0.5-100nM insulin for 8h, and the mRNA expression of GPT, glutamic-oxaloacetic transaminase (GOT), γ-glutamyltransferase (GGT), PCK1, G6PC and FBP1 was measured. We also investigated the extent of histone acetylation around these genes. Insulin suppressed the mRNA expression of gluconeogenesis genes (GPT2, GOT1, GOT2, GGT1, GGT2, G6PC, and PCK1) in HepG2 cells in a dose-dependent manner. mRNA levels of GPT2, but not GPT1, were decreased by insulin. Histone acetylation was also reduced around GPT2, G6PC, and PCK1 in response to insulin. The expression of GPT2 and other gluconeogenesis genes such as G6PC and PCK1 was suppressed by insulin, in association with decreases in histone H3 and H4 acetylation surrounding these genes. Copyright © 2017 Elsevier Inc. All rights reserved.

Qualification of the GASGUARD® SAS GGT Arsine Sub-Atmospheric Gas Delivery System for Ion Implantation

NASA Astrophysics Data System (ADS)

Dunn, James P.; Rolland, James L.; Grim, James S.; Machado, Reinaldo M.; Hartz, Christopher L.

2006-11-01

A beta level evaluation of the GASGUARD® SAS GGT Arsine ion implant dopant supply developed by Air Products and Chemicals, Inc. was conducted by Atmel Corporation. The evaluation included characterization of the normalized wafer yield, mass spectra, ionization efficiency, flow rate, beam current, extraction of usable material and cylinder lifetime. This new and novel sub-atmospheric dopant gas delivery system utilizes a unique electrochemical process, which can generate, on demand, high flows of arsine at a constant 400 torr pressure while limiting net inventory of arsine to only 1 gram. This paper illustrates how Atmel Corporation evaluated and released this new arsine dopant delivery system for commercial production and verified high delivery capacity, resulting in reduced gas costs and increased cylinder life compared to the traditional adsorbent based technology.

Heterogeneity of the Stearoyl-CoA desaturase-1 (SCD1) Gene and Metabolic Risk Factors in the EPIC-Potsdam Study

PubMed Central

Arregui, Maria; Buijsse, Brian; Stefan, Norbert; Corella, Dolores; Fisher, Eva; di Giuseppe, Romina; Coltell, Oscar; Knüppel, Sven; Aleksandrova, Krasimira; Joost, Hans-Georg; Boeing, Heiner; Weikert, Cornelia

2012-01-01

Background Stearoyl-CoA desaturase-1 (SCD1) is an enzyme involved in lipid metabolism. In mice and humans its activity has been associated with traits of the metabolic syndrome, but also with the prevention of saturated fatty acids accumulation and subsequent inflammation, whereas for liver fat content inconsistent results have been reported. Thus, variants of the gene encoding SCD1 (SCD1) could potentially modify metabolic risk factors, but few human studies have addressed this question. Methods In a sample of 2157 middle-aged men and women randomly drawn from the Potsdam cohort of the European Prospective Investigation into Cancer and Nutrition, we investigated the impact of 7 SCD1 tagging-single nucleotide polymorphisms (rs1502593, rs522951, rs11190480, rs3071, rs3793767, rs10883463 and rs508384) and 5 inferred haplotypes with frequency >5% describing 90.9% of the genotype combinations in our population, on triglycerides, body mass index (BMI), waist circumference (WC), glycated haemoglobin (HbA1c), high-sensitivity C-reactive protein (hs-CRP), gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT) and fetuin-A. Results No significant associations between any of the SNPs or haplotypes and BMI, WC, fetuin-A and hs-CRP were observed. Associations of rs10883463 with triglycerides, GGT and HbA1c as well as of rs11190480 with ALT activity, were weak and became non-significant after multiple-testing correction. Also associations of the haplotype harbouring the minor allele of rs1502593 with HbA1c levels, the haplotype harbouring the minor alleles of rs11190480 and rs508384 with activity of ALT, and the haplotype harbouring the minor alleles of rs522951, rs10883463 and rs508384 with triglyceride and HbA1C levels and GGT activities did not withstand multiple-testing correction. Conclusion These findings suggest that there are no associations between common variants of SCD1 or its inferred haplotypes and the investigated metabolic risk factors. However, given

Enzyme activities in plasma, liver, and kidney of black ducks and mallards

USGS Publications Warehouse

Franson, J. Christian

1982-01-01

Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine phosphokinase (CPK), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were measured in plasma, liver, and kidney, and gamma-glutamyl transferase (GGT) was measured in liver and kidney of black ducks (Anas rubripes). Activities of ALT, AST, GGT, and ornithine carbamyl transferase (OCT) were assayed in plasma, liver, and kidney of game-farm mallards (Anas platyrhynchos). Appreciable OCT and AST activity occurred in both liver and kidney. Activities of ALT, CPK, ALP and GGT were higher in kidney, while LDH was higher in liver, GGT was detected in plasma from one of four mallards.

Fatty acid ethyl ester concentrations in hair and self-reported alcohol consumption in 644 cases from different origin.

PubMed

Süsse, Silke; Selavka, Carl M; Mieczkowski, Tom; Pragst, Fritz

2010-03-20

For diagnosis of chronic alcohol abuse, fatty acid ethyl esters (FAEE) were determined in hair samples from 644 individuals, mainly parents from child protection cases. The analysis for ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate was performed according to a validated procedure consisting of external degreasing by two times washing with n-heptane, extraction with a mixture of dimethylsulfoxide and n-heptane, separation and evaporation of the n-heptane layer, headspace solid phase microextraction of the residue after addition of phosphate buffer pH 7.6 and gas chromatography-mass spectrometry using deuterated internal standards. For interpretation, the sum of the concentrations of the four esters C(FAEE) was used with the cut-off's 0.5 ng/mg for the proximal scalp hair segment 0-3 cm or less and 1.0 ng/mg for scalp hair samples with a length between 3 and 6 cm and for body hair. C(FAEE) ranged from 0.11 to 31 ng/mg (mean 1.77 ng/mg, median 0.82 ng/mg). The mean concentration ratio between the 4 esters was 8:45:38:9. 298 cases had C(FAEE) above the cut-off's. Self-reported drinking data were obtained in 553 of the cases in the categories abstinent (156 cases), moderate drinking (252 cases) and excessive drinking (145 cases). Median and box-plot data clearly demonstrate differentiation of these ingestor sub-populations by C(FAEE). However, in the abstinent and moderate groups the consumption was frequently underreported (37 and 110 cases positive) whereas in the group self-reported excessive drinking 32 cases were negative. Comparison of C(FAEE) with carbohydrate-deficient transferrin (CDT) in 139 cases and gamma-glutamyltransferase (GGT) in 136 cases showed a good agreement in CDT- and GGT positive cases (27/28 and 32/41) but a large portion of the negative CDT- and GGT-results with positive hair test (44/100 and 48/95) which is explained mainly by the much shorter time window of CDT and GGT. No significant correlation was found between persons

High-Dose Micafungin for Preterm Neonates and Infants with Invasive and Central Nervous System Candidiasis.

PubMed

Auriti, Cinzia; Falcone, Marco; Ronchetti, Maria Paola; Goffredo, Bianca Maria; Cairoli, Sara; Crisafulli, Rosamaria; Piersigilli, Fiammetta; Corsetti, Tiziana; Dotta, Andrea; Pai, Manjunath P

2016-12-01

High doses of micafungin are advocated in neonates with systemic candidiasis, but limited pharmacokinetic (PK) and safety data are available to support their use. Eighteen preterm neonates and infants with systemic candidiasis, three of whom had meningitis, were treated for at least 14 days with 8 to 15 mg/kg of body weight/day of intravenous micafungin. Plasma micafungin concentrations (four measurements for each patient) were determined after the third dose, and the cerebrospinal fluid (CSF) micafungin concentrations in three patients were also obtained. Population PK analyses were used to identify the optimal model, and the model was further validated using external data (n = 5). The safety of micafungin was assessed by measurement of the levels of liver and kidney function biomarkers. The mean age and weight at the initiation of treatment were 2.33 months (standard deviation [SD], 1.98 months) and 3.24 kg (SD, 1.61 kg), respectively. The optimal PK model was one that scaled plasma clearance to weight and the transaminase concentration ratio. The CSF of three patients was sampled, and the observed concentrations were between 0.80 and 1.80 mg/liter. The model-predicted mean micafungin area under the concentration-time curve over 24 h was 336 mg · h/liter (SD, 165 mg · h/liter) with the 10-mg/kg/day dosage. Eighteen of the 23 subjects (78.2%) had clinical resolution of their infection, but 5 had neurologic impairments. Among the transaminases, alkaline phosphatase measurements were significantly higher posttreatment, with a geometric mean ratio of 1.17 (90% confidence interval, 1.01, 1.37). Furthermore, marked elevations in the gamma-glutamyltransferase (GGT) level were observed in three patients treated with 10- to 15-mg/kg/day doses, and improvement of the GGT level was noted after a dose reduction. Higher weight-based doses of micafungin were generally well tolerated in neonates and infants and achieved pharmacokinetic profiles predictive of an effect

Effects of structural injure in the bile bacterial contamination after balloon transduodenal sphincteroplasty (papillary dilation) in dogs.

PubMed

Zavadinack Netto, Martin; Fagundes, Djalma José; Bandeira, César Orlando Peralta

2006-01-01

To evaluate, in dogs, the biliary sphincter subjected to dilation by hydrostatic balloon by the point of view of structural alterations of the papilla and the biochemestry and bacterial contamination of the bile. Twenty dogs were submitted to laparotomy, duodenotomy, and enlargement of the major duodenal papilla- GA(n=10) - with balloon of 8mm inflated with pressure of 0,5 atm, during 2 minutes or to the sham procedure - GB(n=10). Blood samples collected on times t(0 day), t(7 days) and t(28 days) were subjected to dosages of alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) for cholestasis evaluation. The collected material from the gall bladder at the same times were registered and numbered to be submitted to culture in BHI, blood agar (rich, non-selective element) and Mac Conkey (selective element for Gram-negative bacillus. On the 28th day three fragments of the papilla were tranversally cut by the choledoc axis 3mm from the duodenal papilla and the cuts, stained with hematoxylin-eosin and Masson's tricome, were evaluated according to their inflammatory reaction. The GGT and ALP averages on the three periods in the groups A and B did not show significant differences, not being characterizes the cholestasis. The bacterian contamination was significantly higher in GA (2,19) than in GB (1,96); the contamination was lower in the initial time compared with 7 and 28 days (t0

Probing the Donor and Acceptor Substrate Specificity of the Gamma-Glutamyl Transpeptidase

DTIC Science & Technology

2012-01-17

glutathione can function as a source of cysteine. Mutant strains of F. tularensis that lack functional GGT have been shown to have impaired intracellular...conservation of structure and function between human and bacterial GGT homologues, significant differences in acceptor substrate and inhibitor preferences are...with the lowest value of MODELER objective function . The three-dimensional (3D) fold of the generated models was verified with PROSA II,40 and

Excessive drinking--brief intervention by a primary health care nurse. A randomized controlled trial.

PubMed

Tomson, Y; Romelsjö, A; Aberg, H

1998-09-01

To evaluate the effect of a nurse-conducted intervention on excessive drinkers. Randomized, controlled trial. Vårby Health Centre, Stockholm. The intervention group visited a nurse three times during a 12-month period. The controls met once with a general practitioner (GP). Patients were recruited at a health screening on the basis of a raised gamma-glutamyl transferase (GGT). Of 2338 subjects, aged 25-54 years, 222 had a screening GGT of > or = 0.9 mukat/l. 100 were randomized to the treatment and 122 to the control group. GGT, self-reported alcohol consumption (g/week), sickness allowance and use of health care. After 2 years a reduction of GGT from 1.52 to 1.21 mukat/l (p = 0.02) had occurred in the treatment group. The controls increased their mean level of GGT from 1.75 to 2.16 mukat/l. Mean weekly alcohol consumption in the intervention group was reduced from 337 to 228 g/week (p = 0.02). The controls did not quantify their alcohol consumption initially, but reported a reduced weekly consumption at follow-up. The intervention had an impact on GGT and self-reported consumption. The controls also reported decreased consumption possibly because their appointment with the GP functioned as a very brief intervention.

Different Roles of 8‐Hydroxyguanine Formation and 2‐Thiobarbituric Acid‐reacting Substance Generation in the Early Phase of Liver Carcinogenesis Induced by a Choline‐deficient, l‐Amino Acid‐defined Diet in Rats

PubMed Central

Nakae, Dai; Mizumoto, Yasushi; Yoshiji, Hitoshi; Andoh, Nobuaki; Horiguchi, Kohsuke; Shiraiwa, Kazumi; Kobayashi, Eisaku; Endoh, Takehiro; Shimoji, Naoshi; Tamura, Kazutoshi; Tsujiuchi, Toshifumi; Denda, Ayumi

1994-01-01

The present study was performed to assess the roles of hepatocellular oxidative damage to DNA and constituents other than DNA in rat liver carcinogenesis caused by a choline‐deficient, l‐amino acid‐defined (CDAA) diet by examining the effects of the antioxidant N, N′‐diphenyl‐p‐phenylenediamine (DPPD). The parameters used for cellular oxidative damage were the level of 8‐hydroxyguanine (8‐OHGua) for DNA and that of 2‐thiobarbituric acid‐reacting substance (TBARS) for constituents other than DNA. A total of 40 male Fischer 344 rats, 6 weeks old, were fed the CDAA diet for 12 weeks with or without DPPD (0.05, 0.10 or 0.20%) or butylated hydroxytoluene (BHT, 0.25%). In the livers of the rats, the numbers and sizes of glutathione S‐transferasc (EC 2.5.1.18) placental form (GSTP)‐ and/or γ‐glutamyltransferase (GGT, EC 2.3.2.2)‐positive lesions and levels of 8‐OHGua and TBARS were determined. The GSTP‐positive lesions of 0.08 mm2 or larger were all stained positively for GGT as well in cross‐sectional area, whereas the smaller lesions were generally negative for GGT. DPPD and BHT reduced the size of the GSTP‐positive lesions without affecting their total numbers. At the same time, they reduced TBARS generation without affecting 8‐OHGua formation in DNA. The present results indicate that oxidative DNA damage (represented by 8‐OHGua formation) and damage to constituents other than DNA (represented by TBARS generation) may play different roles in rat liver carcinogenesis caused by the CDAA diet; the former appears to be involved in the induction of phenotypically altered hepatocyte populations while the latter may be related to the growth of such populations. PMID:8014108

[Relationship of visceral adiposity index with serum aminotransferase and nonalcoholic fatty liver disease in patients with sleep apnea].

PubMed

Qi, Jiachao; Lin, Qichang; Lin, Xin; Chen, Xiao

2015-11-10

To evaluate the relationship of visceral adiposity index (VAI) with serum aminotransferase levels and incidence of nonalcoholic fatty liver disease (NAFLD) in patients with sleep apnea (SA). Between January 2011 and December 2014, participants who were referred from Fujian Provincial Sleep-disordered Breathing (SDB) Clinic Center with repeated snoring or a clinical suspicion of SDB were recruited. All individuals underwent polysomnography (PSG) testing and an abdominal ultrasonography scan during this period. They were classified into four groups by apnea-hypopnea index (AHI), non-SA group, mild, moderate and severe group (AHI<5/h, 5-<15/h, 15-<30/h, ≥30/h, respectively). The differences in SA-related parameters, serum aminotransferase and VAI were tested, and the correlations of VAI with indices of PSG and serum aminotransferase were analyzed using Spearman coefficient. Receiver operating characteristic (ROC) curve was conducted to obtain a cut-off value of VAI for predicting NAFLD. Afterwards, logistic regression was performed to analyze VAI's predictive ability regarding incidence of NAFLD in SDB patients. A total of 152 participants including 110 males and 42 females were analyzed, with mean age (51.1±11.3) years. There were 20 subjects in non-SA group, 31 in mild, 39 in moderate and 62 in severe group, with 92 NAFLD patients and 60 controls. No differences in sex, age, alkaline phosphatase were observed among groups according to AHI. However, body mass index, waist circumference, AHI, lowest oxygen saturation, oxygen desaturation index(ODI), VAI, alanine aminotransferase (ALT), aspartate aminotransferase, gamma glutamyltransferase (GGT) and incidence of NAFLD were significantly different among groups. Significant positive relations were observed between VAI and AHI (β=0.222, P=0.006), ODI (β=0.216, P=0.008), ALT (β=0.237, P=0.003), GGT (β=0.238, P=0.003). As shown in ROC curve, the cut-off point of VAI for predicting NAFLD was 1.59 in all individuals

Naltrexone versus acamprosate: one year follow-up of alcohol dependence treatment.

PubMed

Rubio, G; Jiménez-Arriero, M A; Ponce, G; Palomo, T

2001-01-01

Naltrexone and acamprosate reduce relapse in alcohol dependence. They have not yet been compared in a published trial. The aim of this study was to compare the efficacy of these compounds in conditions similar to those in routine clinical practice. Random allocation to a year of treatment with naltrexone (50 mg/day) or acamprosate (1665-1998 mg/day) was made in 157 recently detoxified alcohol-dependent men with moderate dependence (evaluated using the Addictions Severity Index and Severity of Alcohol Dependence Scale). All were patients whom a member of the family would accompany regularly to appointments. Alcohol consumption, craving and adverse events were recorded weekly for the first 3 months, and then bi-weekly, by the treating psychiatrist who was not blinded. At 3-monthly intervals, investigators who were blinded to the treatment documented patients' alcohol consumption based on patients' accounts, information given by the psychiatrists when necessary, and reports from patients' families. Serum gamma-glutamyltransferase (GGT) was also measured. Efforts were made to sustain the blindness of the investigators. The same investigator did not assess the same patient twice. The integrity of the blindness was not checked. There was no difference between treatments in mean time to first drink (naltrexone 44 days, acamprosate 39 days) but the time to first relapse (five or more drinks in a day) was 63 days (naltrexone) versus 42 days (acamprosate) (P = 0.02). At the end of 1 year, 41% receiving naltrexone and 17% receiving acamprosate had not relapsed (P = 0.0009). The cumulative number of days of abstinence was significantly greater, and the number of drinks consumed at one time and severity of craving were significantly less, in the naltrexone group compared to the acamprosate group, as was the percentage of heavy drinking days (P = 0.038). More patients in the acamprosate than the naltrexone group were commenced on disulfiram during the study. Naltrexone patients

Gut epithelial barrier markers in patients with obstructive sleep apnea.

PubMed

Barceló, Antonia; Esquinas, Cristina; Robles, Juan; Piérola, Javier; De la Peña, Mónica; Aguilar, Irene; Morell-Garcia, Daniel; Alonso, Alberto; Toledo, Nuria; Sánchez-de la Torre, Manuel; Barbé, Ferran

2016-10-01

Obstructive sleep apnea (OSA) is now being recognized as an additional contributing factor to the pathogenesis of obesity-related comorbidities. At the same time, there is now increasing evidence to suggest that intestinal wall permeability plays a role in the development of metabolic syndrome. In the present study, circulating zonulin and fatty acid binding protein (I-FABP) were measured in association with metabolic, hepatic, and inflammatory parameters. Compared with controls, plasma I-FABP levels were significantly higher in patients with OSA (571 pg/mL [IQR 290-950] vs 396 pg/mL [IQR 234-559], p = 0.04). Zonulin levels were similar between groups. Significant relationships were observed between zonulin levels and waist circumference (p < 0.05), glucose (p < 0.05), and insulin (p < 0.05). In addition, in the OSA group, zonulin levels correlated negatively with the mean nocturnal oxygenation saturation (p < 0.05) and positively with total cholesterol (p < 0.05), alanine aminotransferase (ALT) (p < 0.005), aminotransferase (AST) (p < 0.01), gamma glutamyltransferase (GGT) (p < 0.005), and high-sensitivity C-reactive protein (hs-CRP) (p < 0.05). Multivariate analysis showed that associations between zonulin and ALT, AST, and hs-CRP were attenuated, but not eliminated, after adjustment for other variables. The results of this study suggest that OSA is a risk factor for intestinal damage, regardless of metabolic profile, and that intestinal permeability might be a possible contributor to nonalcoholic fatty liver disease in patients with OSA. Copyright © 2016 Elsevier B.V. All rights reserved.

Reference values for 34 frequently used laboratory tests in 80-year-old men and women.

PubMed

Helmersson-Karlqvist, Johanna; Ridefelt, Peter; Lind, Lars; Larsson, Anders

2016-10-01

Reference values are usually based on blood samples from healthy individuals in the age range 20-50 years. Most patients seeking health care are older than this reference population. Many reference intervals are age dependent and there is thus a need to have appropriate reference intervals also for elderly individuals. We analyzed a group of frequently used laboratory tests in an 80-year-old population (n=531, 266 females and 265 males). The 2.5th and 97.5th percentiles for these markers were calculated according to the International Federation of Clinical Chemistry guidelines on the statistical treatment of reference values. Reference values are reported for serum alanine transaminase (ALT), albumin, alkaline phosphatase, pancreatic amylase, apolipoprotein A1, apolipoprotein B, apolipoprotein B/apolipoprotein A1 ratio, aspartate aminotransferase (AST), AST/ALT ratio, bilirubin, calcium, calprotectin, cholesterol, HDL-cholesterol, creatinine kinase (CK), creatinine, creatinine estimated GFR, C-reactive protein, cystatin C, cystatin C estimated GFR, gamma-glutamyltransferase (GGT), iron, iron saturation, lactate dehydrogenase (LDH), magnesium, phosphate, transferrin, triglycerides, urate, urea, zinc, hemoglobin, platelet count and white blood cell count. The upper reference limit for creatinine and urea was significantly increased while the lower limit for iron and albumin was decreased in this elderly population in comparison with the population in the Nordic Reference Interval Project (NORIP). Reference values calculated from the whole population and a subpopulation without cardiovascular disease showed strong concordance. Several of the reference interval limits were outside the 90% confidence interval of NORIP. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Hypocaloric high-protein diet improves clinical and biochemical markers in patients with nonalcoholic fatty liver disease (NAFLD).

PubMed

Bezerra Duarte, Sebastião Mauro; Faintuch, Joel; Stefano, José Tadeu; Sobral de Oliveira, Maria Beatriz; de Campos Mazo, Daniel Ferraz; Rabelo, Fabiola; Vanni, Denise; Nogueira, Monize Aydar; Carrilho, Flair José; Marques Souza de Oliveira, Claudia Pinto

2014-01-01

To investigate the role of hypocaloric highprotein diet, a prospective clinical study was conducted in NAFLD patients. Pre-versus post-interventional data were analyzed in 48 stable NAFLD patients (submitted to a hypocaloric high-protein diet during 75 days. Variables included anthropometrics (body mass index/ BMI and waist circumference/WC), whole-body and segmental bioimpedance analysis and biochemical tests. Diet compliance was assessed by interviews every two weeks. BMI, WC and body fat mass remained relatively stable (-1.3%, -1.8% and -2.5% respectively, no significance). HDL- cholesterol increased (P < 0.05) whereas total, LDL and VLDL cholesterol, triglycerides, aspartate aminotransferase/ AST, gamma glutamyltransferase/GGT, alkaline phosphatase/ AP, fasting blood glucose and glycated hemoglobin/ HbA1c decreased (P < 0.05). When patients were stratified according to increase (22/48, 45.8%) and decrease (21/48, 43.8%) of BMI, association between weight decrease and liver benefit could be elicited in such circumstances for ALT, AP and AST/ALT ratio. No change could be demonstrated in patients who gained weight. Multivariate assessment confirmed that waist circumference, ferritin, triacylglycerol, and markers of glucose homeostasis were the most relevant associated with liver enzymes. Ours results are consistent with the literature of calorie restriction in the management of NAFLD. Changes in lifestyle and weight loss are recommended for NAFLD patients. European guidelines also support this recommendation. This is the first study that demonstrated that a high protein, hypocaloric diet were associated with improvement of lipid profile, glucose homeostasis and liver enzymes in NAFLD independent on BMI decrease or body fat mass reduction.

Stability of Chronic Hepatitis-Related Parameters in Serum Samples After Long-Term Storage.

PubMed

Yu, Rentao; Dan, Yunjie; Xiang, Xiaomei; Zhou, Yi; Kuang, Xuemei; Yang, Ge; Tang, Yulan; Liu, Mingdong; Kong, Weilong; Tan, Wenting; Deng, Guohong

2017-06-01

Serum samples are widely used in clinical research, but a comprehensive research of the stability of parameters relevant to chronic hepatitis and the effect of a relatively long-term (up to 10 years) storage on the stability have rarely been studied. To investigate the stability of chronic hepatitis-related parameters in serum samples after long-term storage. The storage stability of common clinical parameters such as total bile acid (TBA), total bilirubin (TBIL), potassium, cholesterol, and protein parameters such as alanine aminotransferase (ALT), creatine kinase (CK), γ-glutamyltransferase (GGT), albumin, high-density lipoprotein (HDL) and also hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA, hepatitis B surface antigen (HBsAg), and chemokine (C-X-C motif) ligand 10 (CXCL10) were tested in serum samples after storing at -20°C or -70°C for 1, 2, 3, 7, 8, and 10 years. Levels of TBA, TBIL, and protein parameters such as ALT, CK, GGT, HDL, and HBsAg decreased significantly, but levels of potassium and cholesterol increased significantly after long-term storage, whereas blood glucose and triglycerides were stable during storage. HBV DNA remained stable at -70°C but changed at -20°C, whereas HCV RNA was stable after 1-, 2-, and 3-year storage. CXCL10 was still detectable after 8-year storage. Low temperatures (-70°C/80°C) are necessary for storage of serum samples in chronic hepatitis B research after long-term storage.

Primary photosensitization caused by ingestion of Froelichia humboldtiana by dairy goats.

PubMed

Santos, Danielle S; Silva, Caio C B; Araújo, Valber O; de Fátima Souza, Maria; Lacerda-Lucena, Patrícia B; Simões, Sara V D; Riet-Correa, Franklin; Lucena, Ricardo B

2017-01-01

This study aimed to describe the first report of an outbreak of primary photosensitization in dairy goats caused by Froelichia humboldtiana. The disease occurred from March to May 2014, in a mixed flock of 15 Saanen, Alpine, and crossbred lactating goats. The entire flock was affected; however, the Saanen and cross-bred goats developed more severe lesions, and their milk production decreased by as much as 75%. Lesions were progressive and consisted of skin hyperemia, edema, and necrosis, especially in depigmented areas. An experimental study with two goats resulted in photodermatitis, similar to that observed in the natural cases, 10-14 days after the beginning of plant ingestion. Serum activities of aspartate aminotransferase (AST) and -glutamyltransferase (GGT) and, direct, indirect, and total bilirubin serum concentrations were within the normal ranges. In conclusion, F. humboldtiana causes primary photosensitization in goats with a negative impact on milk production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hb Hope [beta136(H14)Gly-->Asp (GGT-->GAT)]: interactions with Hb S [beta6(A3)Glu-->Val (GAG-->GTG)], other variant hemoglobins and thalassemia.

PubMed

Ingle, John; Adewoye, Adeboye; Dewan, Robert; Okoli, Michael; Rollins, Lamarr; Eung, Shawn H; Luo, Hong-Yuan; Chui, David H K; Steinberg, Martin H

2004-01-01

Hb Hope [beta136(H14)Gly-->Asp (GGT-->GAT)] was first described in an African-American family in 1965. Since then, it has been found in combination with several different globin gene mutations in many other families of divergent ethnic backgrounds. The basis for its relatively frequent occurrences remains unexplained. This variant hemoglobin (Hb) is mildly unstable and has reduced oxygen affinity, but is generally innocuous clinically. This variant Hb can present as a confounding factor in arriving at a correct diagnosis by either electrophoresis or high performance liquid chromatography (HPLC), particularly during the neonatal period. DNA-based diagnostics can help solve this potential problem.

Human γ-glutamyl transpeptidase 1: Structures of the free enzyme, inhibitor-bound tetrahedral transition states, and glutamate-bound enzyme reveal novel movement within the active site during catalysis [Human gamma-glutamyl transpeptidase: Inhibitor binding and movement within the active site

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

Terzyan, Simon S.; Burgett, Anthony W. G.; Heroux, Annie

γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within themore » active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. Lastly,tThese data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use.« less

Human γ-glutamyl transpeptidase 1: Structures of the free enzyme, inhibitor-bound tetrahedral transition states, and glutamate-bound enzyme reveal novel movement within the active site during catalysis [Human gamma-glutamyl transpeptidase: Inhibitor binding and movement within the active site

DOE PAGES

Terzyan, Simon S.; Burgett, Anthony W. G.; Heroux, Annie; ...

2015-05-26

γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within themore » active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. Lastly,tThese data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use.« less

A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women.

PubMed

Abazarfard, Zohreh; Eslamian, Ghazaleh; Salehi, Mousa; Keshavarzi, Sareh

2016-03-01

Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss. This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women. This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m(2)] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention. Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001). AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after an NFD in women.

A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women

PubMed Central

Abazarfard, Zohreh; Eslamian, Ghazaleh; Salehi, Mousa; Keshavarzi, Sareh

2016-01-01

Background: Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss. Objectives: This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women. Patients and Methods: This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m2] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention. Results: Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001). Conclusions: AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after

[Design of a preoperative predictive score for choledocholithiasis].

PubMed

Bueno Lledó, Jose; Ibáñez Cirión, Jose Luis; Torregrosa Gallud, Antonio; López Andújar, Rafael

2014-11-01

Choledocholithiasis is the most common cause of obstructive jaundice and occurs in 5-10% of patients with cholelithiasis. To design a preoperative predictive score for choledocholithiasis. A prospective study was carried out in 556 patients admitted to our department for biliary disease. Preoperative clinical, laboratory, and ultrasound variables were compared between patients without choledocholithiasis and 65 patients with this diagnosis. A multivariate logistic analysis was performed to obtain a predictive model of choledocholithiasis, determining sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Predictors of choledocholithiasis were the presence of a prior history of biliary disease (history of biliary colic, acute cholecystitis, choledocholithiasis or acute biliary pancreatitis) (p=0.021, OR=2.225, 95% CI: 1.130-4.381), total bilirubin values >4mg/dl (p=0.046, OR=2.403, 95% CI: 1.106-5.685), alkaline phosphatase values >150mg/dl (p=0.022 income, OR=2.631, 95%: 1.386-6.231), gamma-glutamyltransferase (GGT) values >100mg/dl (p=0.035, OR=2.10, 95% CI: 1.345-5.850), and an ultrasound finding of biliary duct >8mm (p=0.034, OR=3.063 95% CI: 1086-8649). A score superior to 5 had a specificity and PPV of 100% for detecting choledocholithiasis and a score less than 3 had a sensitivity and NPV of 100% for excluding this diagnosis. The preoperative score can exclude or confirm the presence of choledocholithiasis and allows patients to directly benefit from laparoscopic cholecystectomy (LC) or prior endoscopic retrograde cholangiopancreatography (ERCP). Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

Alcohol Biomarkers in Clinical and Forensic Contexts.

PubMed

Andresen-Streichert, Hilke; Müller, Alexander; Glahn, Alexander; Skopp, Gisela; Sterneck, Martina

2018-05-04

Biomarkers of alcohol consumption are important not only in forensic contexts, e.g., in child custody proceedings or as documentation of alcohol abstinence after temporary confiscation of a driver's license. They are increasingly being used in clinical medicine as well for verification of abstinence or to rule out the harmful use of alcohol. This review is based on pertinent publications that were retrieved by a selective literature search in PubMed concerning the direct and indirect alcohol markers discussed here, as well as on the authors' experience in laboratory analysis and clinical medicine. Alongside the direct demonstration of ethanol, the available markers of alcohol consumption include the classic indirect markers carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and mean corpuscular volume (MCV) as well as direct alcohol markers such as ethyl glucuronide (EtG) and ethyl sulfate (EtS) in serum and urine and EtG and fatty acid ethyl esters (FAEE) in hair. Phosphatidylethanol (PEth) is a promising parameter that com - plements the existing spectrum of tests with high specificity (48-89%) and sensi - tivity (88-100%). In routine clinical practice, the demonstration of positive alcohol markers often leads patients to admit previously denied alcohol use. This makes it possible to motivate the patient to undergo treatment for alcoholism. The available alcohol biomarkers vary in sensitivity and specificity with respect to the time period over which they indicate alcohol use and the minimum extent of alcohol use that they can detect. The appropriate marker or combination of markers should be chosen in each case according to the particular question that is to be answered by laboratory analysis.

Influence of training and a maximal exercise test in analytical variability of muscular, hepatic, and cardiovascular biochemical variables.

PubMed

Romagnoli, Marco; Alis, Rafael; Aloe, Rosalia; Salvagno, Gian Luca; Basterra, Javier; Pareja-Galeano, Helios; Sanchis-Gomar, Fabian; Lippi, Giuseppe

2014-04-01

Short, middle, and long-term exercise, as well as the relative intensity of the physical effort, may influence a broad array of laboratory results, and it is thereby of pivotal importance to appropriately differentiate the 'physiologic' from the 'pathological' effects of exercise. Therefore, the values of some biomarkers in physically active subjects may be cautiously interpreted since the results may fall outside the conventional reference ranges. It has been demonstrated that middle and long-term endurance and/or strenuous exercise triggers transient elevations of muscular and cardiac biomarkers. However, no data have been published about the effect of short-term maximal exercise test on the most useful muscular, hepatic and cardiovascular biomarkers. The aim of the present study was to assess the baseline concentrations of muscular, hepatic, and cardiovascular makers between trained and untrained subjects, along with changes induced by maximal exercise test. We measured C reactive protein (CRP), procalcitonin (PCT), gamma glutamyltransferase (GGT), creatine kinase-MB isoenzyme (CK-MB), Hs-TnT, NT-proBNP, CK, LDH, AST, and ALT in serum samples of physically active (trained) and physically inactive (sedentary) male collected before, immediately after a maximal exercise test and after a 30-min recovery period. Trained subjects tend to have significantly raised base concentrations of CK, CK-MB, ALT, and LDH compared to sedentary individuals, and this can be clearly interpreted as a mild injury of skeletal muscle. A single maximal exercise was also effective to transiently increase the concentrations of NT-proBNP, but not those of Hs-TnT, thus suggesting that the cardiac involvement is mostly benign in nature.

Incidence of Abnormal Liver Biochemical Tests in Hyperthyroidism

PubMed Central

Lin, Tiffany Y.; Shekar, Anshula O.; Li, Ning; Yeh, Michael W.; Saab, Sammy; Wilson, Mark; Leung, Angela M.

2017-01-01

Objective Abnormal serum liver function tests are common in patients with untreated thyrotoxicosis, even prior to the initiation of antithyroidal medications that may worsen their severity. There is a wide range of the incidence of these abnormalities in the published literature. The aim of this study was to assess the risks factors and threshold of thyrotoxicosis severity for developing an abnormal liver biochemical test upon the diagnosis of new thyrotoxicosis. Design Single-institution retrospective cohort study. Patients Patients ≥18 years old receiving medical care at a large, academic, urban U.S. medical center between 2002–2016. Measurements Inclusion criteria were a serum thyroid stimulating hormone [TSH] concentration < 0.3 mIU/L or ICD-9 code for thyrotoxicosis, with thyrotoxicosis confirmed by either a concurrent elevated serum triiodothyronine (T3) and/or thyroxine (T4) concentration [total or free] within 3 months), and an available liver biochemical test(s) within 6 months of thyrotoxicosis. The biochemical liver tests assessed were serum aspartate transaminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyltransferase (GGT), total bilirubin, and conjugated bilirubin concentrations. Results In this cohort of 1,514 subjects, the overall incidence of any biochemical liver test abnormality within 6 months of thyrotoxicosis was 39%. An initial serum TSH concentration <0.02 mIU/L, male gender, and African-American race were significant predictors of an abnormal serum liver biochemical test within 6 months of the diagnosis of new-onset untreated thyrotoxicosis. Conclusions This study identifies risk factors for patients who develop an abnormal serum liver biochemical test result within 6 months of a diagnosis of untreated thyrotoxicosis. PMID:28199740

Incidence of abnormal liver biochemical tests in hyperthyroidism.

PubMed

Lin, Tiffany Y; Shekar, Anshula O; Li, Ning; Yeh, Michael W; Saab, Sammy; Wilson, Mark; Leung, Angela M

2017-05-01

Abnormal serum liver function tests are common in patients with untreated thyrotoxicosis, even prior to the initiation of antithyroidal medications that may worsen the severity of the abnormal serum liver biochemistries. There is a wide range of the incidence of these abnormalities in the published literature. The aim of this study was to assess the risks factors and threshold of thyrotoxicosis severity for developing an abnormal liver biochemical test upon the diagnosis of new thyrotoxicosis. Single-institution retrospective cohort study. Patients of ≥18 years old receiving medical care at a large, academic, urban US medical centre between 2002-2016. Inclusion criteria were a serum thyroid stimulating hormone (TSH) concentration of <0·3 mIU/l or ICD-9 code for thyrotoxicosis, with thyrotoxicosis confirmed by either a concurrent elevated serum triiodothyronine (T3) or thyroxine (T4) concentration ([total or free] within 3 months), and an available liver biochemical test(s) within 6 months of thyrotoxicosis. The biochemical liver tests assessed were serum aspartate transaminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyltransferase (GGT), total bilirubin, and conjugated bilirubin concentrations. In this cohort of 1514 subjects, the overall incidence of any biochemical liver test abnormality within 6 months of thyrotoxicosis was 39%. An initial serum TSH concentration <0·02 mIU/l, male gender, and African-American race were significant predictors of an abnormal serum liver biochemical test within 6 months of the diagnosis of new-onset untreated thyrotoxicosis. This study identifies risk factors for patients who develop an abnormal serum liver biochemical test result within 6 months of a diagnosis of untreated thyrotoxicosis. © 2017 John Wiley & Sons Ltd.

Oxidative Stress as Estimated by Gamma-Glutamyl Transferase Levels Amplifies the Alkaline Phosphatase-Dependent Risk for Mortality in ESKD Patients on Dialysis

PubMed Central

Mattace-Raso, Francesco; van Saase, Jan L. C. M.; Postorino, Maurizio; Tripepi, Giovanni Luigi; Mallamaci, Francesca; PROGREDIRE Study Group

2016-01-01

Alkaline phosphatase (Alk-Phos) is a powerful predictor of death in patients with end-stage kidney disease (ESKD) and oxidative stress is a strong inducer of Alk-Phos in various tissues. We tested the hypothesis that oxidative stress, as estimated by a robust marker of systemic oxidative stress like γ-Glutamyl-Transpeptidase (GGT) levels, may interact with Alk-Phos in the high risk of death in a cohort of 993 ESKD patients maintained on chronic dialysis. In fully adjusted analyses the HR for mortality associated with Alk-Phos (50 IU/L increase) was progressively higher across GGT quintiles, being minimal in patients in the first quintile (HR: 0.89, 95% CI: 0.77–1.03) and highest in the GGT fifth quintile (HR: 1.13, 95% CI: 1.03–1.2) (P for the effect modification = 0.02). These findings were fully confirmed in sensitivity analyses excluding patients with preexisting liver disease, excessive alcohol intake, or altered liver disease biomarkers. GGT amplifies the risk of death associated with high Alk-Phos levels in ESKD patients. This observation is compatible with the hypothesis that oxidative stress is a strong modifier of the adverse biological effects of high Alk-Phos in this population. PMID:27525053

Effect of butaphosphan and cyanocobalamin on postpartum metabolism and milk production in dairy cows.

PubMed

Pereira, R A; Silveira, P A S; Montagner, P; Schneider, A; Schmitt, E; Rabassa, V R; Pfeifer, L F M; Del Pino, F A B; Pulga, M E; Corrêa, M N

2013-07-01

The aim of this study was to determine the effect of butaphosphan and cyanocobalamin (BTPC) supplementation on plasma metabolites and milk production in postpartum dairy cows. A total of fifty-two Holstein cows were randomly assigned to receive either: (1) 10 ml of saline (NaCl 0.9%, control group); (2) 1000 mg of butaphosphan and 0.5 mg of cyanocobalamin (BTPC1 group); and (3) 2000 mg of butaphosphan and 1.0 mg of cyanocobalamin (BTPC2 group). All cows received injections every 5 days from calving to 20 days in milk (DIM). Blood samples were collected every 15 days from calving until 75 DIM to determine serum concentration of glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), cholesterol, urea, calcium (Ca), phosphorus (P), magnesium (Mg), aminotransferase aspartate (AST) and γ-glutamyltransferase (GGT). The body condition score (BCS) and milk production were evaluated from calving until 90 DIM. Increasing doses of BTPC caused a linear reduction in plasma concentrations of NEFA and cholesterol. Supplementation of BTPC also reduced concentrations of BHB but it did not differ between the two treatment doses. Milk yield and milk protein had a linear increase with increasing doses of BTPC. A quadratic effect was detected for milk fat and total milk solids according to treatment dose, and BTPC1 had the lowest mean values. Concentrations of glucose, urea, P, Mg, AST, GGT, milk lactose and BCS were not affected by treatment. These results indicate that injections of BTPC during the early postpartum period can reduce NEFA and BHB concentrations and increase milk production in Holstein cows.

Serum phospholipid omega-3 polyunsaturated fatty acids and insulin resistance in type 2 diabetes mellitus and non-alcoholic fatty liver disease.

PubMed

Lou, Da-Jun; Zhu, Qi-Qian; Si, Xu-Wei; Guan, Li-Li; You, Qiao-Ying; Yu, Zhong-Ming; Zhang, Ai-Zhen

2014-01-01

To investigate the relationship between serum phospholipid omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and insulin resistance (IR) in patients with type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD). 51 patients with T2DM and NAFLD (T2DM+NAFLD group), 50 with T2DM alone (T2DM group), 45 with NAFLD alone (NAFLD group), and 42 healthy control subjects (NC group) were studied. Serum ω-3 PUFA profiles were analyzed by gas chromatography, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and serum lipid concentrations were measured. Insulin resistance was assessed by the homeostasis model assessment method (HOMA-IR). HOMA-IR levels were higher in the T2DM+NAFLD group than in the T2DM, NAFLD and NC groups (p<0.05), as were ALT, AST, GGT, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) concentrations (p<0.05). Conversely, serum ω-3 PUFA levels were significantly lower in the T2DM+NAFLD group than in the other groups (p<0.05). The ω-3 PUFA level was negatively correlated with HOMA-IR, TC, LDL-C and TG. Serum phospholipid ω-3 PUFA levels were significantly decreased in patients with T2DM and NAFLD, and were negatively related with insulin resistance. Thus, reduced ω-3 PUFAs may play an important role in the development of T2DM and NAFLD. Copyright © 2014 Elsevier Inc. All rights reserved.

Synergistic association of changes in serum uric acid and triglycerides with changes in insulin resistance after walking exercise in community-dwelling older women.

PubMed

Kawamoto, Ryuichi; Katoh, Takeaki; Ninomiya, Daisuke; Kumagi, Teru; Abe, Masanori; Kohara, Katsuhiko

2016-05-01

Serum uric acid (SUA) and triglyceride (TG) levels are strongly correlated with insulin resistance; however, the association after a walking exercise program in community-dwelling older women has not been investigated. The present study included 100 postmenopausal women (mean ± standard deviation, 68 ± 7 years) from a rural village in Japan. The Nordic walking program of 120 min per week was performed for 12 weeks. Before and after the intervention, SUA, TG, various relevant factors and homeostasis model assessment of insulin resistance (HOMA-IR) were measured. Multivariate linear regression analysis showed that baseline TG and γ-glutamyltransferase (GGT) were significantly associated with baseline HOMA-IR. After the 12-week training program, changes in TG, SUA and GGT were significantly associated with changes in HOMA-IR. In addition to their direct associations, we observed a synergistic association between changes in TG and SUA and changes in HOMA-IR. Participants were divided into three groups (tertiles) according to changes in TG and SUA. The tertiles of changes in SUA correlated significantly with changes in HOMA-IR in participants in the tertile with the greatest decrease in TG (r = 0.525, p = 0.001), but not in the other two tertiles of change in TG (r = 0.049, p = 0.699). There was a significant interaction between SUA and TG for changes in HOMA-IR (β = 0.281, p = 0.005). These results suggest that changes in TG and SUA are synergistic factors associated with changes in insulin resistance after a 12-week walking exercise program in community-dwelling older women.

[Predictive value of liver enzymes and alcohol consumption for risk of type 2 diabetes].

PubMed

Ma, Xiaokun; Wang, Qingzhu; Qin, Guijun; Zhao, Yanyan; Zhang, Yinghui; Ma, Xiaojun; Li, Zhizhen; Wang, Zhimin; Ren, Gaofei; Bi, Yufang; Wang, Weiqing; Ning, Guang

2015-01-01

To compare the predictive value of liver enzymes and alcohol consumption for determining risk of type 2 diabetes (T2DM). A cross-sectional study was conducted in Zhengzhou with a total of 2, 693 men.Participants' height, weight, and histories of smoking and drinking were recorded. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT) and blood glucose, as well as related metabolic indexes were detected. Moderate daily alcohol consumption (more than 35 g ethanol/week and less than 140 g ethanol/week) decreased the risk of type 2 diabetes (OR =0.376, 95% CI:0.306 -0.463, P less than 0.05) but increased risk for higher levels of GGT and ALT (OR GGT =3.012, 95% CI:2.357-3.849, Pless than 0.01; ORALT =1.473, 95% CI:1.043-2.081, Pless than 0.05). In joint analyses of alcohol consumption and liver enzymes, the group of nondrinkers/light drinkers (less than or equal to 35 g ethanol/week) in the fourth quartile of GGT levels had the highest risk for type 2 diabetes (OR =12.219, 95% CI:6.217-24.016, P less than 0.01). The relationship of ALT and daily alcohol consumption with the risk of type 2 diabetes was almost the same as that of GGT (nondrinkers/light drinkers in the fourth quartile of ALT levels (OR =5.357, 95% CI:3.070-9.350, P less than 0.0 1). GGT, ALT and daily alcohol consumption were independently associated with risk of type 2 diabetes. Nondrinkers/light drinkers with the highest levels ofGGT orALT were at high risk of type 2 diabetes.

Z{gamma}{gamma}{gamma} {yields} 0 Processes in SANC

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

Bardin, D. Yu., E-mail: bardin@nu.jinr.ru; Kalinovskaya, L. V., E-mail: kalinov@nu.jinr.ru; Uglov, E. D., E-mail: corner@nu.jinr.ru

2013-11-15

We describe the analytic and numerical evaluation of the {gamma}{gamma} {yields} {gamma}Z process cross section and the Z {yields} {gamma}{gamma}{gamma} decay rate within the SANC system multi-channel approach at the one-loop accuracy level with all masses taken into account. The corresponding package for numeric calculations is presented. For checking of the results' correctness we make a comparison with the other independent calculations.

Hepatoprotective and hypoglycemic effects of a tannin rich extract from Ximenia americana var. caffra root.

PubMed

Sobeh, Mansour; Mahmoud, Mona F; Abdelfattah, Mohamed A O; El-Beshbishy, Hesham A; El-Shazly, Assem M; Wink, Michael

2017-09-15

Liver diseases and diabetes are serious health disorders associated with oxidative stress and ageing. Some plant polyphenols can lower the risk of these diseases. We investigated the phytochemical profiling of a root extract from Ximenia americana var. caffra using HPLC-PDA-ESI-MS/MS. The antioxidant activities in vitro were investigated. The hepatoprotective activities were studied in rat models with d-galactosamine (d-GaIN)-induced hepatotoxicity and the antidiabetic activities in STZ-diabetic rats were also investigated. HPLC-PDA-ESI-MS/MS was used to identify plant phenolics. The antioxidant activities in vitro were determined using DPPH and FRAP assays. The in vivo hepatoprotective activities were determined for d-GaIN-induced hepatotoxicity in rats. We determined the liver markers alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), liver peroxidation product malondialdehyde (MDA), glutathione content (GSH), albumin and total bilirubin concentration. The histopathological changes in rat liver were also studied. The antidiabetic activities were also investigated in STZ-diabetic rats and serum glucose, serum insulin hormone, and lipid peroxides were determined. The root extract is rich in tannins with 20 compounds including a series of stereoisomers of (epi)catechin, (epi)catechin-(epi)catechin, (epi)catechin-(epi)catechin-(epi)catechin, and their galloyl esters. Promising antioxidant potential was observed in vitro in DPPH assay with EC 50 of 6.5 µg extract / 26 µg raw material and in FRAP assay with 19.54 mM FeSO 4 compared with ascorbic acid (EC 50 of 2.92 µg/ml) and quercetin (FeSO 4 24.04 mM/mg), respectively. Significant reduction of serologic enzymatic markers and hepatic oxidative stress markers such as ALT, AST, MDA, GGT, and total bilirubin, as well as elevation of GSH and albumin were observed in rats with d-galactosamine-induced liver damage treated with the extract. These findings agree

Sneaky Gamma-Rays: Using Gravitational Lensing to Avoid Gamma-Gamma-Absorption

NASA Astrophysics Data System (ADS)

Boettcher, Markus; Barnacka, Anna

2014-08-01

It has recently been suggested that gravitational lensing studies of gamma-ray blazars might be a promising avenue to probe the location of the gamma-ray emitting region in blazars. Motivated by these prospects, we have investigated potential gamma-gamma absorption signatures of intervening lenses in the very-high-energy gamma-ray emission from lensedblazars. We considered intervening galaxies and individual stars within these galaxies. We find that the collective radiation field of galaxies acting as sources of macrolensing are not expected to lead to significant gamma-gamma absorption. Individual stars within intervening galaxies could, in principle, cause a significant opacity to gamma-gamma absorption for VHE gamma-rays if the impact parameter (the distance of closest approach of the gamma-ray to the center of the star) is small enough. However, we find that the curvature of the photon path due to gravitational lensing will cause gamma-ray photons to maintain a sufficiently large distance from such stars to avoid significant gamma-gamma absorption. This re-inforces the prospect of gravitational-lensing studies of gamma-ray blazars without interference due to gamma-gamma absorption due to the lensing objects.

Liver Function Indicators Performed Better to Eliminate Cardioembolic Stroke than to Identify It from Stroke Subtypes.

PubMed

Tan, Ge; Yuan, Ruozhen; Hao, Zilong; Lei, Chunyan; Xiong, Yao; Xu, Mangmang; Liu, Ming

2017-01-01

Identifying the etiology of ischemic stroke is essential to acute management and secondary prevention. The value of liver function indicators in differentiating stroke subtypes remains to be evaluated. A total of 1333 acute ischemic stroke patients were included. Liver function indicators collected within 24 hours from stroke onset, including alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase, gamma-glutamyl transpeptidase (GGT), and bilirubin (BILI), were collapsed into quartiles (Q) and also dichotomized by Q1. Multivariate regression analysis was conducted to identify the independent association between liver function indicators and cardioembolic stroke (SCE). Area under the curve (AUC) of receiver operating characteristic analysis was conducted, and sensitivity (Sen), specificity (Spe), positive prospective value (PPV), and negative prospective value (NPV) were determined to evaluate the predictive value of liver function indicators for SCE. AST, GGT, and BILI were associated with SCE. After adjustment, only AST was related to SCE independently. The incidence of SCE in the Q1 of AST, GGT, and BILI, particularly in the Q1 of AST, was quite low. The ability of AST, GGT, and BILI to identify SCE was poor, with low AUC, Sen, and PPV. The value of AST, GGT, and BILI in eliminating SCE from stroke subtypes was good, with high Spe and moderate NPV, and was enhanced after combining each liver function indicator. Results of present study demonstrated that AST, GGT, and BILI, particularly AST, had a potential to eliminate SCE from stroke subtypes, and the ability of eliminating SCE would be strengthened after combining each liver function indicator together. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Dynamic of oxidative and nitrosative stress markers during the convalescent period of stroke patients undergoing rehabilitation.

PubMed

Manolescu, Bogdan Nicolae; Berteanu, M; Oprea, E; Chiriac, N; Dumitru, L; Vladoiu, S; Popa, O; Ianas, O

2011-07-01

Stroke patients have a redox imbalance, a consequence of both the cerebrovascular event and the associated pathological conditions. Our study was aimed to investigate the dynamic of some oxidative and nitrosative markers during the convalescent phase of postacute stroke patients undergoing rehabilitation. We assessed thiol, advanced oxidation protein product, protein carbonyl, 3-nitro-l-tyrosine, ceruloplasmin and oxidized LDL concentrations, as well as gamma-glutamyltranspeptidase (GGT) activity in 20 patients at the beginning of the hospitalization and at the discharge moment, respectively, and 24 apparently healthy controls. We found significantly increased values for GGT (P = 0.04), ceruloplasmin (P = 0.01) and protein carbonyl (P = 0.04) in stroke patients at the hospitalization moment when compared with healthy controls, while total thiols were significantly decreased (P = 0.002). Rehabilitation was associated with a significant decrease of protein carbonyl (P = 0.03) and oxidized LDL particle concentrations (P = 0.03), as well as GGT activity (P = 0.02). At the hospitalization moment, both GGT and ceruloplasmin were significantly negatively correlated with non-proteic thiols (r = -0.44, P = 0.049, and r = -0.53, P = 0.015, respectively) and significantly positively with protein carbonyls (r = +0.80, P < 0.001, and r = +0.69, P < 0.001, respectively) suggesting putative roles of GGT and ceruloplasmin in the redox imbalance. These results highlight the existence of a redox imbalance in postacute stroke patients, and the possible benefits of an antioxidant-based therapy for the recovery of these patients.

Prevalence and Predictors of Abnormal Liver Enzymes in Young Women with Anorexia Nervosa

PubMed Central

Fong, Hiu-fai; DiVasta, Amy D.; DiFabio, Diane; Ringelheim, Julie; Jonas, Maureen M.; Gordon, Catherine M.

2008-01-01

Objective To determine the prevalence and predictors of abnormal liver enzyme levels in ambulatory young women with anorexia nervosa (AN). Study design In this cross-sectional study of 53 females with AN, serum concentrations of liver enzymes and hormones were measured. Anthropometric, dietary, and body composition information was collected. Correlational analyses were performed between liver enzyme concentrations and these variables. Results Elevated alanine aminotransferase (ALT) and gamma-glutamyltranspeptidase (GGT) levels were found in 14 subjects (26%) and 5 subjects (9%), respectively. ALT and GGT were inversely correlated with body mass index (r = −0.27 to −0.30, p ≤ 0.049) and percentage body fat (r = −0.36 to −0.47, p ≤ 0.007), but showed no relationship with lean body mass. Subjects with percentage body fat < 18% had higher ALT levels than those above this threshold (median 26.5 vs. 18.0 U/L, p = 0.01). Liver enzyme concentrations did not correlate with dietary variables, except for GGT and percentage of calories from protein (r = 0.28, p = 0.04). Conclusions Serum ALT and GGT concentrations are inversely related to adiposity in young women with AN. Future studies are needed to determine if these liver enzyme elevation signify unrecognized, clinically relevant liver disease. PMID:18534220

The Z {yields} cc-bar {yields} {gamma}{gamma}*, Z {yields} bb-bar {yields} {gamma}{gamma}* triangle diagrams and the Z {yields} {gamma}{psi}, Z {yields} {gamma}Y decays

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

Achasov, N. N., E-mail: achasov@math.nsc.ru

2011-03-15

The approach to the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decay study is presented in detail, based on the sum rules for the Z {yields} cc-bar {yields} {gamma}{gamma}* and Z {yields} bb-bar {yields} {gamma}{gamma}* amplitudes and their derivatives. The branching ratios of the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decays are calculated for different hypotheses on saturation of the sum rules. The lower bounds of {Sigma}{sub {psi}} BR(Z {yields} {gamma}{psi}) = 1.95 Multiplication-Sign 10{sup -7} and {Sigma}{sub {upsilon}} BR(Z {yields} {gamma}Y) = 7.23 Multiplication-Sign 10{sup -7} are found. Deviations from the lower bounds are discussed, including the possibilitymore » of BR(Z {yields} {gamma}J/{psi}(1S)) {approx} BR(Z {yields} {gamma}Y(1S)) {approx} 10{sup -6}, that could be probably measured in LHC. The angular distributions in the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decays are also calculated.« less

Usefulness of indirect alcohol biomarkers for predicting recidivism of drunk-driving among previously convicted drunk-driving offenders: results from the recidivism of alcohol-impaired driving (ROAD) study.

PubMed

Maenhout, Thomas M; Poll, Anneleen; Vermassen, Tijl; De Buyzere, Marc L; Delanghe, Joris R

2014-01-01

In several European countries, drivers under the influence (DUI), suspected of chronic alcohol abuse are referred for medical and psychological examination. This study (the ROAD study, or Recidivism Of Alcohol-impaired Driving) investigated the usefulness of indirect alcohol biomarkers for predicting drunk-driving recidivism in previously convicted drunk-driving offenders. The ROAD study is a prospective study (2009-13) that was performed on 517 randomly selected drivers in Belgium. They were convicted for drunk-driving for which their licence was confiscated. The initial post-arrest blood samples were collected and analysed for percentage carbohydrate-deficient transferrin (%CDT), transaminsase activities [alanine amino transferase (ALT), aspartate amino transferase (AST)], gamma-glutamyltransferase (γGT) and red cell mean corpuscular volume (MCV). The observation time for each driver was 3 years and dynamic. A logistic regression analysis revealed that ln(%CDT) (P < 0.001), ln(γGT) (P < 0.01) and ln(ALT) (P < 0.05) were the best biochemical predictors of recidivism of drunk-driving. The ROAD index (which includes ln(%CDT), ln(γGT), -ln(ALT) and the sex of the driver) was calculated and had a significantly higher area under the receiver operator characteristic curve (0.71) than the individual biomarkers for drunk-driving recidivism. Drivers with a high risk of recidivating (ROAD index ≥ 25%; third tertile) could be distinguished from drivers with an intermediate risk (16% ≤ ROAD index < 25%; second tertile; P < 0.001) and a low recidivism risk (ROAD index < 16%; first tertile; P < 0.05). Of all routinely used indirect alcohol markers, percentage of carbohydrate-deficient transferrin is the major predictor of recidivism of drunk-driving. The association with gamma-glutamyltransferase, alanine amino transferase and the sex of the driver could have additional value for identifying drunk-drivers at intermediate risk of

The association between the 844ins68 polymorphism in the CBS gene and breast cancer

PubMed Central

Figuera-Villanueva, Luis Eduardo; Ramos-Silva, Adriana; Salas-González, Efraín; Puebla-Pérez, Ana María; Peralta-Leal, Valeria; García-Ortiz, José Elías; Dávalos-Rodríguez, Ingrid Patricia; Zúñiga-González, Guillermo Moisés

2014-01-01

Introduction The cystathionine beta synthase (CBS) gene plays an important role in homocysteine metabolism because it catalyzes the first step of the transsulfuration pathway, during which homocysteine is converted to cystathionine. Polymorphisms of CBS have been associated with cancer. Material and methods We examined the role of the 844ins68 polymorphism by comparing the genotypes of 371 healthy Mexican women with the genotypes of 323 Mexican women with breast cancer (BC). Results The observed genotype frequencies for controls and BC patients were 1% and 2% for Ins/Ins, 13% and 26% for W/Ins, and 86% and 72% for W/W, respectively. We found that the odds ratio (OR) was 2.2, with a 95% confidence interval (95% CI) of 1.5–3.3, p = 0.0001. The association was also evident when comparing the distribution of the W/Ins-Ins/Ins genotypes in patients in the following categories: 1) menopause and high γ-glutamyltransferase (GGT) levels (OR of 2.17, 95% CI: 1.17–4.26, p = 0.02), 2) chemotherapy response and high lactate dehydrogenase (LDH) levels (OR 2.2, 95% CI: 1.08–4.4, p = 0.027), 3) chemotherapy response and high GGT levels (OR 2.46, 95% CI: 1.2–4.8, p = 0.007), and 4) body mass index (BMI) and III–IV tumor stage (OR 3.2, 95% CI: 1.2–8.3, p = 0.013). Conclusions We conclude that the genotypes W/Ins-Ins/Ins of the 844ins68 polymorphism in the CBS gene contribute significantly to BC susceptibility in the analyzed sample from the Mexican population. PMID:25624861

Influence of boar breeds or hybrid genetic composition on semen quality and seminal plasma biochemical variables.

PubMed

Žaja, Ivona Žura; Samardžija, Marko; Vince, Silvijo; Majić-Balić, Ivanka; Vilić, Marinko; Đuričić, Dražen; Milinković-Tur, Suzana

2016-01-01

The enzyme concentrations of seminal plasma are important for spermatozoa metabolism and function in boars. The need has arisen for introducing a biochemical evaluation of semen, along with the usual standard semen analyses. There are no data on the influence of boar breeds on the seminal plasma biochemical variables investigated in this study. Therefore, the objective was to determine the influence of breed and hybrid genetic composition of boars on semen quality and seminal plasma biochemical variables. Semen samples of 27 boars (Swedish Landrace, German Landrace, Large White, Pietrain and Pig Improvement Company hybrid-PIC-hybrid), aged between 1.5 and 3 years, were collected. After evaluation of semen quality, the seminal plasma was separated from the spermatozoa by centrifugation of semen. The seminal plasma was subjected to spectrophotometric analysis to determine alkaline phosphatase (ALP), acid phosphatase (ACP), γ-glutamyltransferase (GGT), creatine kinase (CK) and lactate dehydrogenase (LDH) and to atomic absorption spectrophotometric analysis to measure the concentration of calcium and magnesium. Conventional semen quality variables differed depending on breed and PIC-hybrid genetic composition, though these differences were typically insignificant. In the seminal plasma, significant differences were determined in enzyme activity (ALP, GGT, CK and LDH) and in calcium concentration among boars of different breeds. There are, therefore, differences in semen quality and significant differences in the seminal plasma biochemical variables among boars of different breeds and PIC-hybrid genetic composition. The data and differences in semen variables detected in the present study provide knowledge for enhancing evaluation and monitoring of boar reproductive potential, semen quality and explain the potential causes of boar infertility. Copyright © 2015 Elsevier B.V. All rights reserved.

Recommendation to Exclude Bile-Duct-Cannulated Rats with Hyperbilirubinemia for Proper Conduct of Biliary Drug Excretion Studies.

PubMed

Kato, Koji; Hasegawa, Yoshitaka; Iwata, Katsuya; Ichikawa, Takuya; Yahara, Tohru; Tsuji, Satoshi; Sugiura, Masayuki; Yamaguchi, Jun-Ichi

2016-08-01

Hyperbilirubinemia (HB) is sometimes encountered following bile-duct cannulation in rats. It possibly originates from the reduced functioning of multidrug resistance-associated protein 2 (Mrp2) and subsequent adaptive alterations in the expression of Mrp3 and the organic anion transporting polypeptides (Oatps). Our aim was to clarify the importance of excluding bile-duct-cannulated (BDC) rats with HB for proper conduct of drug excretion studies. We detected HB [serum total bilirubin concentration (TBIL) ≥0.20 mg/dl] in 16% of all BDC rats prepared. The serum activities of aspartate aminotransferase, alanine aminotransferase, leucine aminopeptidase, and alkaline phosphatase were within the respective normal ranges in the BDC rats with mild HB (TBIL, 0.20-0.79 mg/dl), indicating the absence of hepatic failure. In the pharmacokinetics of pravastatin, an Oatps/Mrp2 probe drug in the BDC rats, the apparent volume of distribution and the clearance were smaller in the mild HB group as compared with the normal group, suggesting the reduction of apparent hepatic uptake and hepatobiliary elimination. The biliary excretion (percentage of dose) was significantly reduced by 54%, suggesting that the biliary efflux activity via Mrp2 was reduced to a greater extent relative to metabolic activity in hepatocytes. The serum γ-glutamyltransferase (GGT) activity correlated with TBIL and inversely correlated with biliary excretion of pravastatin, a finding which could serve as a clue to uncover the regulatory system involving cooperation between GGT and Mrp2. In conclusion, BDC rats with HB, however mild, should be excluded from drug excretion studies to avoid the risk of underestimation of the biliary excretion of drugs. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Liver enzymes and blood metabolites in a population of free-ranging red deer (Cervus elaphus) naturally infected with Fascioloides magna.

PubMed

Severin, K; Mašek, T; Janicki, Z; Konjević, D; Slavica, A; Marinculić, A; Martinković, F; Vengušt, G; Džaja, P

2012-06-01

We investigated the effects of Fascioloides magna infection on the serum biochemistry values of the naturally infected red deer population in eastern Croatia. The investigation was performed on 47 red deer with F. magna infection confirmed patho-anatomically in 27 animals (57.4%). Fibrous capsules and migratory lesions were found in 14 deer while only fibrous capsules without migratory lesions were found in 13 deer. In 13 deer both immature and mature flukes were found, in 5 deer only immature flukes were found and in 9 deer only mature flukes were found. Fascioloides magna infected deer with fibrous capsules and migratory lesions had significantly higher values for lactate dehydrogenase (LDH), glutamate dehydrogenase (GLDH) and globulin, and lower values for albumin/globulin ratio and glucose compared to uninfected deer. Fascioloides magna infected deer with fibrous capsules without the presence of migratory lesions had higher values for alanine aminotransferase (ALT) and globulin, and lower values for albumin/globulin ratio and glucose, than the uninfected deer. The number of immature flukes was positively correlated with values of aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), LDH, GLDH, urea and triglycerides. The number of migratory lesions was positively correlated with GGT, GLDH, globulin and urea values. The creatinine value was positively correlated with the number of mature flukes. The trial showed that F. magna infection causes significant changes in serum biochemistry. Moreover, these changes do not completely resemble changes following F. hepatica infection. Further investigation of changes in liver enzymes and other serum metabolites in controlled, experimentally induced fascioloidosis in red deer is needed to better understand the pathogenesis of F. magna.

Coagulation profile, haematological and biochemical changes in kids naturally infected with peste des petits ruminants.

PubMed

Sahinduran, Sima; Albay, Metin Koray; Sezer, Kenan; Ozmen, Ozlem; Mamak, Nuri; Haligur, Mehmet; Karakurum, Cagri; Yildiz, Ramazan

2012-03-01

The aim of this study was to examine the coagulation profile in peste des petits ruminant (PPR) in kids. Five kids from a group of 150 animals (72 goats and 78 kids) were brought to the Veterinary Medical Teaching Hospital from a farm in Burdur province (Turkey) with nasal and ocular discharges and diarrhea. Fifteen goats and 41 kids had died due to diarrhea and three kids were presented to the Department of Pathology for diagnosis. Blood samples were taken from 12 ill animals (infected group) for haematological and biochemical analysis. In addition, five healthy kids were examined from another healthy flock (control group). Leukocyte and lymphocyte numbers of infected group showed significant declinations in comparison to control group (≤0.001). Haemorrhages in all organs of digestive system and small haemorrhagic areas in liver were caused to decrease in erythrocyte and haematocrit values (p ≤ 0.001) in infected group. Concentrations of blood urea nitrogen (BUN) (p ≤ 0.01) and creatinine (p ≤ 0.001) in infected group were significantly higher than control group. Compared to control group, significant increases were determined in serum concentrations of alkaline phosphatase (ALP) (p ≤ 0.01), aspartate aminotransferase (AST) (p ≤ 0.001) and alanine aminotransferase (ALT) (p ≤ 0.001) in the infected group. No significant differences were observed between the infected and control groups for serum gamma glutamyl-transferase (GGT) concentration value. In our study, thrombocytopenia (p ≤ 0.001) together with prolonged activated partial thromboplastin time (APTT; p ≤ 0.01) and prothrombin time (PT; p ≤ 0.001) may show that disseminated intravascular coagulopathy which can occur in kids with PPR.

Carcinogenicity of by-products of disinfection in mouse and rat liver

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

Herren-Freund, S.L.; Pereira, M.A.

1986-11-01

By-products of disinfection were tested for initiating and/or promoting activity in rat liver by using the rat liver foci bioassay. The assay uses an increased incidence of ..gamma..-glutamyltranspeptidase-positive foci (GGT foci) as an indicator of carcinogenicity. The by-products of disinfection, including chloramine, halogenated humic acids, halogenated ethanes, halogenated acetonitriles, halogenated methanes, halogenated ethylene, and N-Cl piperidine, did not initiate GGT foci, which would indicate that they are not capable of initiating carcinogenesis. Chloroform and halogenated benzenes were tested in this assay for their ability to promote the occurrence of GGT foci and tumors initiated by diethylnitrosamine (DENA). Chloroform either hadmore » no effect or inhibited the occurrence of GGT foci when administered subsequent to a single dose of DENA. However, when the chloroform was administered in drinking water concurrently with weekly doses of DENA, it enhanced the formation of liver tumors. Of 20 halogenated benzenes tested, only 1,2,4,5-tetrachlorobenzene and hexachlorobenzene promoted the occurrence of DENA-initiated GGT foci. Thus in rat liver, the tested by-products of drinking water disinfection did not demonstrate tumor-initiating activity, although a few appeared to possess tumor-promoting activity. Chloroform was also tested for tumor-promoting activity in 15-days-old Swiss mice initiated with ethylnitrosourea (ENU). ENU at 5 and 20 ..mu..g/g caused a dose-dependent increase in liver tumors. In male mice, chloroform inhibited both spontaneous and ENU-induced liver tumors. When administered in the drinking water, chloroform inhibited, whereas phenobarbital promoted, hepatocarcinogenesis in mice.« less

PEDIATRIC VISCERAL ADIPOSITY INDEX ADAPTATION CORRELATES WITH HOMA-IR, MATSUDA, AND TRANSAMINASES.

PubMed

Hernández, María José Garcés; Klünder, Miguel; Nieto, Nayely Garibay; Alvarenga, Juan Carlos López; Gil, Jenny Vilchis; Huerta, Samuel Flores; Siccha, Rosa Quispe; Hernandez, Joselin

2018-03-01

Visceral adiposity index (VAI) is a mathematical model associated with cardiometabolic risk in adults, but studies on children failed to support this association. Our group has proposed a pediatric VAI model using pediatric ranges, but it has not yet been evaluated and needs further adjustments. The objective of this study was to further adjust the proposed pediatric VAI by age, creating a new pediatric metabolic index (PMI), and assess the correlation of the PMI with insulin resistance indexes and hepatic enzymes. A cross-sectional design with data from 396 children (age 5 to 17 years) was analyzed with a generalized linear model to find the coefficients for triglycerides, high-density-lipoprotein cholesterol, and waist circumference-body mass index quotient. The model was constructed according to sex and age and designated PMI. A cross-validation analysis was performed and a receiver operating characteristic curve was used to determine cut-off points. Significant moderate correlation was found between PMI and homeostatic model assessment of insulin resistance (HOMA-IR) ( r = 0.452; P = .003), Matsuda ( r = -0.366; P = .019), alanine aminotransferase ( r = 0.315, P = .045), and γ-glutamyltransferase ( r = 0.397; P = .010). A PMI score >1.7 was considered as risk. PMI correlates with HOMA-IR, Matsuda, and hepatic enzymes. It could be helpful for identifying children at risk for cardiometabolic diseases. ALT = alanine transaminase BMI = body mass index GGT = γ-glutamyltransferase HDL-C = high-density-lipoprotein cholesterol HOMA-IR = homeostatic model assessment of insulin resistance hs-CRP = high sensitivity C-reactive protein ISI = insulin sensitivity index NAFLD = nonalcoholic fatty liver disease PMI = pediatric metabolic index QUICKI = quantitative insulin sensitivity check index ROC = receiver operating characteristic TG = triglyceride TNF-α = tumor necrosis factor-alpha VAI = visceral adiposity index VAT = visceral adipose tissue WC = waist circumference.

Value of gamma-glutamyltranspeptidase-to-platelet ratio in diagnosis of hepatic fibrosis in patients with chronic hepatitis B

PubMed Central

Hu, Yan-Chao; Liu, Hao; Liu, Xiao-Yan; Ma, Li-Na; Guan, Yu-Hua; Luo, Xia; Ding, Xiang-Chun

2017-01-01

AIM To investigate the value of the gamma-glutamyltraspeptidase (GGT)-to-platelet (PLT) ratio (GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B (CHB). METHODS We included 390 untreated CHB patients in this study. The GPR, aspartate aminotransferase (AST)-to-PLT ratio index (APRI), and fibrosis-4 (FIB-4) of all patients were analysed to determine if these parameter were correlated with age, gender, medical history, liver function [total bilirubin (TBil), alanine aminotransferase (ALT), and AST], GGT, PLT count, or hepatic fibrosis stage. The GPR, APRI, and FIB-4, as well as the combination of the GPR and APRI or the GPR and FIB-4 were assessed in different cirrhosis stages using receiver operating characteristic (ROC) curve analysis to evaluate their value in diagnosing hepatic fibrosis in CHB patients. RESULTS The GPR, APRI, and FIB-4 were not correlated with CHB patients’ age, gender, or disease duration (P > 0.05), but all of these parameters were positively correlated with serum ALT, AST, GGT, and PLT count (P < 0.01). Additionally, the GPR, APRI, and FIB-4 were positively correlated with hepatic fibrosis (P < 0.01); the areas under the ROC curve for the GPR in F1, F2, F3, and F4 stages were 0.723, 0.741, 0.826, and 0.833, respectively, which were significantly higher than the respective values for the FIB-4 and APRI (F1: 0.581, 0.612; F2: 0.706, 0.711; F3: 0.73, 0.751; and F4: 0.799, 0.778). The respective diagnostic cut-off points for each stage were 0.402, 0.448, 0.548, and 0.833, respectively. The diagnostic sensitivity and specificity were, respectively, 88.8% and 87.5% in F1, 72.7% and 89.7% in F2, 81.3% and 98.6% in F3, and 80% and 97.4% in F4 when the GPR and APRI were connected in parallel; 86.6% and 90.2%, 78.4% and 96%, 78.6% and 97.4%, and 73.2% and 97.9%, respectively, when the GPR and APRI were connected in series; 80.2% and 89%, 65% and 89%, 70.3% and 98.5%, and 78.8% and 96.8%, respectively, when the GPR and FIB-4

Association between aldehyde dehydrogenase 2 polymorphisms and the incidence of diabetic retinopathy among Japanese subjects with type 2 diabetes mellitus.

PubMed

Morita, Kazunori; Saruwatari, Junji; Miyagawa, Haruna; Uchiyashiki, Yoshihiro; Oniki, Kentaro; Sakata, Misaki; Kajiwara, Ayami; Yoshida, Akira; Jinnouchi, Hideaki; Nakagawa, Kazuko

2013-09-13

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) detoxifies reactive aldehydes in the micro- and macrovasculature. These substrates, including methylglyoxal and 4-hydroxynonenal formed from glucose and lipids, cause protein carbonylation and mitochondrial dysfunction, forming advanced glycation end products (AGEs). The present study aimed to confirm the association between the inactive ALDH2*2 allele and diabetic retinopathy (DR). A retrospective longitudinal analysis was conducted, among 234 Japanese patients with type 2 diabetes mellitus (DM) (156 males and 78 females) who had no DR signs at baseline and were treated for more than half a year. The ALDH2*1/*2 alleles were determined using a real-time TaqMan allelic discrimination assay. Multivariate-adjusted hazard ratios (HRs) and 95% confidential intervals (CIs) for the cumulative incidence of the development of DR were examined using a Cox proportional hazard model, taking drinking habits and the serum γ-glutamyltransferase (GGT) level into consideration. The frequency of the ALDH2*2 allele was 22.3%. Fifty-two subjects cumulatively developed DR during the follow-up period of 5.5 ± 2.5 years. The ALDH2*2 allele carriers had a significantly higher incidence of DR than the non-carriers (HR: 1.92; P = 0.02). The incidence of DR was significantly higher in the drinkers with the ALDH2*2 allele than in those with the ALDH2*1/*1 genotype (HR: 2.61; P = 0.03), while the incidence of DR in the non-drinkers did not differ significantly between the ALDH2 genotype groups (P > 0.05). The incidence of DR was significantly higher in the ALDH2*2 allele carriers with a high GGT level than in the non-carriers with a high or low GGT level (HR: 2.45; P = 0.03; and HR: 2.63; P = 0.03, respectively). To the best of our knowledge, this is the first report of a significant association between the ALDH2*2 allele and the incidence of DR. These findings provide additional evidence that ALDH2 protects both microvasculature and

Anticonvulsant properties of alpha, gamma, and alpha, gamma-substituted gamma-butyrolactones.

PubMed

Klunk, W E; Covey, D F; Ferrendelli, J A

1982-09-01

Derivatives of gamma-butyrolactone (GBL) substituted on the alpha- and/or gamma-positions were synthesized and tested for their effects on behavior in mice, on the electroencephalographs and blood pressure of paralyzed-ventilated guinea pigs, and on electrical activity of incubated hippocampal slices. Several compounds, including alpha-ethyl-alpha-methyl GBL (alpha-EMGBL), alpha, alpha-dimethyl GBL, alpha, gamma-diethyl-alpha, gamma-dimethyl GBL, and gamma-ethyl-gamma-methyl GBL, prevented seizures induced by pentylenetetrazol, beta-ethyl-beta-methyl-gamma-butyrolactone (beta-EMGBL), picrotoxin, or all three compounds in mice and guinea pigs but had no effect on seizures induced by maximal electroshock or bicuculline. Neither gamma-hydroxybutyrate (GHB) nor alpha-isopropylidine GBL had any anticonvulsant activity. The anticonvulsant alpha-substituted compounds had a potent hypotensive effect and antagonized the hypertensive effect of beta-EMGBL, alpha-EMGBL was tested in incubated hippocampal slices and was found to depress basal activity and antagonize excitation induced by beta-EMGBL. These results demonstrate that alpha-alkyl-substituted GBL and, to a lesser extent, gamma-substituted derivatives are anticonvulsant agents and that their effects are strikingly different from those of GHB or beta-alkyl-substituted GBLs, which are epileptogenic. Possibly beta- and alpha-substituted GBLs act at the same site as agonists and antagonists, respectively.

The association of coffee intake with liver cancer risk is mediated by biomarkers of inflammation and hepatocellular injury: data from the European Prospective Investigation into Cancer and Nutrition.

PubMed

Aleksandrova, Krasimira; Bamia, Christina; Drogan, Dagmar; Lagiou, Pagona; Trichopoulou, Antonia; Jenab, Mazda; Fedirko, Veronika; Romieu, Isabelle; Bueno-de-Mesquita, H Bas; Pischon, Tobias; Tsilidis, Kostas; Overvad, Kim; Tjønneland, Anne; Bouton-Ruault, Marie-Christine; Dossus, Laure; Racine, Antoine; Kaaks, Rudolf; Kühn, Tilman; Tsironis, Christos; Papatesta, Eleni-Maria; Saitakis, George; Palli, Domenico; Panico, Salvatore; Grioni, Sara; Tumino, Rosario; Vineis, Paolo; Peeters, Petra H; Weiderpass, Elisabete; Lukic, Marko; Braaten, Tonje; Quirós, J Ramón; Luján-Barroso, Leila; Sánchez, María-José; Chilarque, Maria-Dolores; Ardanas, Eva; Dorronsoro, Miren; Nilsson, Lena Maria; Sund, Malin; Wallström, Peter; Ohlsson, Bodil; Bradbury, Kathryn E; Khaw, Kay-Tee; Wareham, Nick; Stepien, Magdalena; Duarte-Salles, Talita; Assi, Nada; Murphy, Neil; Gunter, Marc J; Riboli, Elio; Boeing, Heiner; Trichopoulos, Dimitrios

2015-12-01

Higher coffee intake has been purportedly related to a lower risk of liver cancer. However, it remains unclear whether this association may be accounted for by specific biological mechanisms. We aimed to evaluate the potential mediating roles of inflammatory, metabolic, liver injury, and iron metabolism biomarkers on the association between coffee intake and the primary form of liver cancer-hepatocellular carcinoma (HCC). We conducted a prospective nested case-control study within the European Prospective Investigation into Cancer and Nutrition among 125 incident HCC cases matched to 250 controls using an incidence-density sampling procedure. The association of coffee intake with HCC risk was evaluated by using multivariable-adjusted conditional logistic regression that accounted for smoking, alcohol consumption, hepatitis infection, and other established liver cancer risk factors. The mediating effects of 21 biomarkers were evaluated on the basis of percentage changes and associated 95% CIs in the estimated regression coefficients of models with and without adjustment for biomarkers individually and in combination. The multivariable-adjusted RR of having ≥4 cups (600 mL) coffee/d compared with <2 cups (300 mL)/d was 0.25 (95% CI: 0.11, 0.62; P-trend = 0.006). A statistically significant attenuation of the association between coffee intake and HCC risk and thereby suspected mediation was confirmed for the inflammatory biomarker IL-6 and for the biomarkers of hepatocellular injury glutamate dehydrogenase, alanine aminotransferase, aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and total bilirubin, which-in combination-attenuated the regression coefficients by 72% (95% CI: 7%, 239%). Of the investigated biomarkers, IL-6, AST, and GGT produced the highest change in the regression coefficients: 40%, 56%, and 60%, respectively. These data suggest that the inverse association of coffee intake with HCC risk was partly accounted for by biomarkers of

Effects of biometrics, location and persistent organic pollutants on blood clinical-chemical parameters in polar bears (Ursus maritimus) from Svalbard, Norway.

PubMed

Ciesielski, Tomasz Maciej; Sonne, Christian; Ormbostad, Ingunn; Aars, Jon; Lie, Elisabeth; Bytingsvik, Jenny; Jenssen, Bjørn Munro

2018-05-31

In the present study, blood clinical-chemical parameters (BCCPs) were analysed in 20 female and 18 male Svalbard polar bears (Ursus maritimus) captured in spring 2007. The aim was to study how age, body condition (BC), biometrics, plasma lipid content and geographical location may confound the relationship between persistent organic pollutants (POPs) including PCBs, HCB, chlordanes, DDTs, HCHs, mirex and OH-PCBs and the concentrations of 12 specific BCCPs (hematocrit [HCT], hemoglobin [HB], aspartate aminotransferase [ASAT], alanine aminotransferase [ALAT], γ-glutamyltransferase [GGT], creatine kinase [CK], triglycerides [TG], cholesterol [CHOL], high-density lipoprotein [HDL], creatinine (CREA], urea, potassium (K]), and to investigate if any of these BCCPs may be applied as potential biomarkers for POP exposure in polar bears. Initial PCA and O-PLS modelling showed that age, lipids, BC and geographical location (longitude and latitude) were important parameters explaining BCCPs in females. Following subsequent partial correlation analyses correcting for age and lipids, multiple POPs in females were still significantly correlated with HCT and HDL (all p < 0.05). In males, age, BM, BC and longitude were important parameters explaining BCCPs. Following partial correlation analyses correcting for age, biometrics, lipids and longitude in males, multiple POPs were significantly correlated with HCT, ASAT, GGT and CHOL (all p < 0.05). In conclusion, several confounding parameters has to be taken into account when studying the relations between BCCPs and POPs in polar bears. When correcting for these, in particular HCT may be used as a simple cost-efficient biomarker of POP exposure in polar bears. Furthermore, decreasing HDL concentrations and increasing CHOL concentration with increasing POP concentrations may indicate responses related to increased risk of cardiovascular disease. We therefore suggest to further study POP exposure and lipidome response to

Changes in markers of liver function in relation to changes in perfluoroalkyl substances - A longitudinal study.

PubMed

Salihovic, Samira; Stubleski, Jordan; Kärrman, Anna; Larsson, Anders; Fall, Tove; Lind, Lars; Lind, P Monica

2018-08-01

While it is known that perfluoroalkyl substances (PFASs) induce liver toxicity in experimental studies, the evidence of an association in humans is inconsistent. The main aim of the present study was to examine the association of PFAS concentrations and markers of liver function using panel data. We investigated 1002 individuals from Sweden (50% women) at ages 70, 75 and 80 in 2001-2014. Eight PFASs were measured in plasma using isotope dilution ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). Bilirubin and hepatic enzymes alanine aminotransferase (ALT), alkaline phosphatase (ALP), and γ-glutamyltransferase (GGT) were determined in serum using an immunoassay methodology. Mixed-effects linear regression models were used to examine the relationship between the changes in markers of liver function and changes in PFAS levels. The changes in majority of PFAS concentrations were positively associated with the changes in activity of ALT, ALP, and GGT and inversely associated with the changes in circulating bilirubin after adjustment for gender and the time-updated covariates LDL- and HDL-cholesterol, serum triglycerides, BMI, statin use, smoking, fasting glucose levels and correction for multiple testing. For example, changes in perfluorononanoic acid (PFNA) were associated with the changes liver function markers β BILIRUBIN  = -1.56, 95% confidence interval (CI) -1.93 to -1.19, β ALT  = 0.04, 95% CI 0.03-0.06, and β ALP  = 0.11, 95% CI 0.06-0.15. Our longitudinal assessment established associations between changes in markers of liver function and changes in plasma PFAS concentrations. These findings suggest a relationship between low-dose background PFAS exposure and altered liver function in the general population. Copyright © 2018 Elsevier Ltd. All rights reserved.

The association of coffee intake with liver cancer risk is mediated by biomarkers of inflammation and hepatocellular injury: data from the European Prospective Investigation into Cancer and Nutrition123

PubMed Central

Aleksandrova, Krasimira; Bamia, Christina; Drogan, Dagmar; Lagiou, Pagona; Trichopoulou, Antonia; Jenab, Mazda; Fedirko, Veronika; Romieu, Isabelle; Bueno-de-Mesquita, H Bas; Pischon, Tobias; Tsilidis, Kostas; Overvad, Kim; Tjønneland, Anne; Bouton-Ruault, Marie-Christine; Dossus, Laure; Racine, Antoine; Kaaks, Rudolf; Kühn, Tilman; Tsironis, Christos; Papatesta, Eleni-Maria; Saitakis, George; Palli, Domenico; Panico, Salvatore; Grioni, Sara; Tumino, Rosario; Vineis, Paolo; Peeters, Petra H; Weiderpass, Elisabete; Lukic, Marko; Braaten, Tonje; Quirós, J Ramón; Luján-Barroso, Leila; Sánchez, María-José; Chilarque, Maria-Dolores; Ardanas, Eva; Dorronsoro, Miren; Nilsson, Lena Maria; Sund, Malin; Wallström, Peter; Ohlsson, Bodil; Bradbury, Kathryn E; Khaw, Kay-Tee; Wareham, Nick; Stepien, Magdalena; Duarte-Salles, Talita; Assi, Nada; Murphy, Neil; Gunter, Marc J; Riboli, Elio; Boeing, Heiner; Trichopoulos, Dimitrios

2015-01-01

Background: Higher coffee intake has been purportedly related to a lower risk of liver cancer. However, it remains unclear whether this association may be accounted for by specific biological mechanisms. Objective: We aimed to evaluate the potential mediating roles of inflammatory, metabolic, liver injury, and iron metabolism biomarkers on the association between coffee intake and the primary form of liver cancer—hepatocellular carcinoma (HCC). Design: We conducted a prospective nested case-control study within the European Prospective Investigation into Cancer and Nutrition among 125 incident HCC cases matched to 250 controls using an incidence-density sampling procedure. The association of coffee intake with HCC risk was evaluated by using multivariable-adjusted conditional logistic regression that accounted for smoking, alcohol consumption, hepatitis infection, and other established liver cancer risk factors. The mediating effects of 21 biomarkers were evaluated on the basis of percentage changes and associated 95% CIs in the estimated regression coefficients of models with and without adjustment for biomarkers individually and in combination. Results: The multivariable-adjusted RR of having ≥4 cups (600 mL) coffee/d compared with <2 cups (300 mL)/d was 0.25 (95% CI: 0.11, 0.62; P-trend = 0.006). A statistically significant attenuation of the association between coffee intake and HCC risk and thereby suspected mediation was confirmed for the inflammatory biomarker IL-6 and for the biomarkers of hepatocellular injury glutamate dehydrogenase, alanine aminotransferase, aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and total bilirubin, which—in combination—attenuated the regression coefficients by 72% (95% CI: 7%, 239%). Of the investigated biomarkers, IL-6, AST, and GGT produced the highest change in the regression coefficients: 40%, 56%, and 60%, respectively. Conclusion: These data suggest that the inverse association of coffee intake

Pretreatment data is highly predictive of liver chemistry signals in clinical trials.

PubMed

Cai, Zhaohui; Bresell, Anders; Steinberg, Mark H; Silberg, Debra G; Furlong, Stephen T

2012-01-01

The goal of this retrospective analysis was to assess how well predictive models could determine which patients would develop liver chemistry signals during clinical trials based on their pretreatment (baseline) information. Based on data from 24 late-stage clinical trials, classification models were developed to predict liver chemistry outcomes using baseline information, which included demographics, medical history, concomitant medications, and baseline laboratory results. Predictive models using baseline data predicted which patients would develop liver signals during the trials with average validation accuracy around 80%. Baseline levels of individual liver chemistry tests were most important for predicting their own elevations during the trials. High bilirubin levels at baseline were not uncommon and were associated with a high risk of developing biochemical Hy's law cases. Baseline γ-glutamyltransferase (GGT) level appeared to have some predictive value, but did not increase predictability beyond using established liver chemistry tests. It is possible to predict which patients are at a higher risk of developing liver chemistry signals using pretreatment (baseline) data. Derived knowledge from such predictions may allow proactive and targeted risk management, and the type of analysis described here could help determine whether new biomarkers offer improved performance over established ones.

Relative tumour promoting activity of three polychlorinated biphenyls in rat liver.

PubMed

Hemming, H; Flodström, S; Wärngård, L; Bergman, A; Kronevi, T; Nordgren, I; Ahlborg, U G

1993-08-02

The relative tumour promoting activity of three structurally and toxicologically diverse polychlorinated biphenyls (3,4,5,3',4'-penta- 2,3,4,3',4'-penta- and 2,4,5,2',4',5'-hexachlorobiphenyl) was measured in an initiation/promotion assay in nitrosodiethylamine-initiated female Sprague-Dawley rats. The congeners under study were administered by once-weekly subcutaneous injections for 20 weeks. Evaluation of the development of gamma-glutamyl transpeptidase (GGT)- and glutation transferase P (GST-P)-positive hepatic foci showed that all congeners promoted altered hepatic foci, although 3,4,5,3',4'-pentachlorobiphenyl was far more potent. The volume fraction of the liver occupied by GGT-positive tissue in the 3,4,5,3',4'-pentachlorobiphenyl-treated animals (100 micrograms/kg per week) was 23%, while the volume fractions of altered liver tissue in the rats treated with 2,3,4,3',4'-pentachlorobiphenyl (5000 micrograms/kg per week) and 2,4,5,2',4',5'-hexaCB (20,000 micrograms/kg per week) were 1.2 and 2.3, respectively. The enhancement of GGT- and GST-P-positive foci was accompanied by an increased incidence of histological changes in the livers.

Motivational interviewing with hazardous drinkers.

PubMed

Beckham, Nancy

2007-02-01

To test the effectiveness of motivational interviewing in a population of hazardous drinkers utilizing community health care centers in rural southeastern Idaho. This study targeted rural people at risk for alcohol dependence utilizing low-income community health care centers in rural southeastern Idaho. The Alcohol Use Disorders Identification Test (AUDIT) was used to screen interested clients' alcohol use. Clients achieving an AUDIT score indicating hazardous alcohol use were recruited into the study and randomized into a control or treatment group. Twenty-six hazardous drinkers attending five low-income community health centers participated in the study. The experimental group participated in one motivational interviewing session with the investigator, a family nurse practitioner (NP). The comparison group received no treatment. Alcohol use was tracked for 6 weeks after successful recruitment into the program. Participants in the study significantly decreased their average number of drinks per day. At time 1 (pretreatment), the control group drank 4.37 drinks per day and the treatment group drank 4.65 drinks per day. At time 2 (posttest), the control group drank 3.77 drinks per day and the treatment group drank 1.95 drinks per day. The effects of the motivational interviewing treatment on hazardous drinking also were measured by serum gamma-glutamyltransferase (GGT), a liver function test. There was also a significant decrease in the GGT from pretest to posttest in the treatment group. The results of this investigation found that motivational interviewing shows promise as an effective intervention for hazardous drinkers attending low-income community clinics. Although other possible explanations could be postulated for the positive changes in sample participants, the data indicate that the motivational interviewing approach was responsible for a significant portion of the positive changes within the current sample. The information collected from the study adds

Low alanine aminotransferase levels and higher number of cardiovascular events in people with Type 2 diabetes: analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

PubMed

Williams, K H; Sullivan, D R; Veillard, A S; O'Brien, R; George, J; Jenkins, A J; Young, S; Ehnholm, C; Duffield, A; Twigg, S M; Keech, A C

2016-03-01

To determine whether alanine aminotransferase or gamma-glutamyltransferase levels, as markers of liver health and non-alcoholic fatty liver disease, might predict cardiovascular events in people with Type 2 diabetes. Data from the Fenofibrate Intervention and Event Lowering in Diabetes study were analysed to examine the relationship between liver enzymes and incident cardiovascular events (non-fatal myocardial infarction, stroke, coronary and other cardiovascular death, coronary or carotid revascularization) over 5 years. Alanine aminotransferase measure had a linear inverse relationship with the first cardiovascular event occurring in participants during the study period. After adjustment, for every 1 sd higher baseline alanine aminotransferase measure (13.2 U/l), the risk of a cardiovascular event was 7% lower (95% CI 4-13; P = 0.02). Participants with alanine aminotransferase levels below and above the reference range 8-41 U/l for women and 9-59 U/l for men, had hazard ratios for a cardiovascular event of 1.86 (95% CI 1.12-3.09) and 0.65 (95% CI 0.49-0.87), respectively (P = 0.001). No relationship was found for gamma-glutamyltransferase. The data may indicate that in people with Type 2 diabetes, which is associated with higher alanine aminotransferase levels because of prevalent non-alcoholic fatty liver disease, a low alanine aminotransferase level is a marker of hepatic or systemic frailty rather than health. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Hb Moscva [β24(B6)Gly→Asp (GGT>GAT), HBB: c.74G>A]: An Unstable Hemoglobin Newly Detected as a De Novo Mutation in a Mauritanian Patient.

PubMed

Ghaber, Sidi M; Trabelsi, Nawel; Salem, Mohamed L; Haddad, Faten; Abba, Aminetou; Darragi, Imen; Abbes, Salem

2018-01-01

Unstable hemoglobins (Hbs) are a group of Hb disorders that could be the origin of chronic hemolytic anemia. Most of these disorders are caused by point mutations taking place in the globin genes and affecting the stability of the Hb molecule. They are inherited as autosomal dominant diseases and described worldwide. Herein we report a new observation of an unstable variant in the Mauritanian population. The patient was a young girl of Mauritanian origin. She presented with chronic hemolytic anemia with an unknown etiology after being referred to several medical centers. Laboratory investigations based on routine analyses, capillary electrophoresis (CE), cation exchange high performance liquid chromatography (HPLC) and DNA sequencing revealed an abnormal unstable Hb known as Hb Moscva [β24(B6)Gly→Asp (GGT>GAT), HBB: c.74G>A] that occurred as a de novo mutation newly detected in an African girl of Mauritanian origin.

Plasma chemistry references values in psittaciformes.

PubMed

Lumeij, J T; Overduin, L M

1990-04-01

Reference values for 17 plasma chemical variables in African greys. Amazons, cockatoos and macaws were established for use in avian clinical practice. The inner limits are given for the percentiles P(2.5) and P(97.5) with a probability of 90%. The following variables were studied: urea, creatinine, uric acid, urea/uric acid ratio, osmolality, sodium, potassium, calcium, glucose, aspartate aminotransferase, alanine aminotransferase, gamma glutamyltransferase, lactate dehydrogenase, creatine kinase, bile acids, total protein, albumin/globulin ratio. Differences between methods used and values found in this study and those reported previously are discussed.

[Dynamic change study of dermatitis medicamentosa-like of trichloroethylene patients with liver damage].

PubMed

Liu, Wei; Zhang, Yan-fang; Zhang, Zhi-min; Li, Pei-mao; Jiang, Xiao-dong; Zhou, Gui-feng; Liu, Jian-jun

2011-10-01

Observing the dynamic change characteristics of serum liver function indexes in occupational dermatitis medicamentosa-like of trichloroethylene patients with liver damage, we can underlie for guiding therapy, prognosis and mechanism of dermatitis medicamentosa-like of trichloroethylene patients with liver damage. We collected serum of 10 cases of occupational dermatitis medicamentosa-like of trichloro-ethylene patients with liver damage from different time points since they were hospitalized, using automatic biochemistry analyzer to detect total protein (TP), albumin (ALB), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), albumin/globulin ratio etc 11 liver function biochemical indicators. We used Excel to establish database, professional drawing software gnuplot to draw dynamic variation diagram of each index. The variation range of 11 liver function indexes of 10 cases was TP 43.2-74.2 g/L, ALB 24.6-44.6 g/L, A/G 0.77-2.10, TBIL 3.7-268.2 umol/L, DBIL 1.0-166.0 umol/L, IBIL 2.4 -167.5 umol/L, ALT 11-5985 U/L, AST 14-5586 U/L, GGT 15-1500 U/L, ALP 35-309 U/L, S/L 0.07-1.94, respectively. TBIL, DBIL, ALT, AST, GGT, ALP concentration significantly increased, especially ALT, AST, GGT, ALT topped 5985 U/L, AST topped 5586 U/L, GGT topped 1500 U/L. But TP, ALB and S/L significantly decreased, TP lowest to 43.2 g/L, S/L lowest to 0.07. A/G basically remained unchanged, but IBIL didn't change regularly. The early liver damage in dermatitis medicamentosa-like of trichloroethylene patients was serious, and repeatedly attacked, so we should lead to enough attention to the clinical work and prevention. This also provided the basis for studying the mechanism of trichloroethylene poisoning.

Predictive factors for the severity of liver fibrosis in patients with chronic hepatitis C and moderate alcohol consumption.

PubMed

Vădan, Roxana; Gheorghe, Liana; Becheanu, Gabriel; Iacob, Răzvan; Iacob, Speranţa; Gheorghe, Cristian

2003-09-01

Among the histological lesions seen in chronic hepatitis C (CHC), the presence of steatosis, bile duct lesions and lymphoid aggregates are characteristic. Recent reports suggest that steatosis is an independent risk factor for liver fibrosis in CHC. The aim of our study was to determine the relative contribution of steatosis and moderate alcohol consumption to the severity of liver fibrosis in patients infected with genotype 1 hepatitis C virus. We evaluated the patients with biopsy proven CHC and no or only moderate alcohol intake (<40 g/day). The demographical parameters of the study population, the indices of alcohol consumption: erythrocyte median corpuscular volume (MCV), gamma-glutamyl transpeptidase (GGT), the histological characteristics were noted and a statistical analysis was performed in order to determine the factors independently associated with severe fibrosis and with severe steatosis. From the 200 patients included in the study, 82 were males and 118 females, with a mean age of 47.75+/-10.42 years. At univariate analysis, advanced (grade 2, 3) fibrosis correlated with: the age at the time of biopsy, increased inflammatory activity (HAI), moderate/severe steatosis, alcohol intake, elevated GGT and MCV values. After multivariate logistic regression only age, HAI and steatosis were independently associated with advanced fibrosis stage. Regarding hepatic steatosis, from the factors found to correlate with severe steatosis at univariate analysis (alcohol intake, elevated GGT and MCV levels, severe fibrosis), after multivariate logistic regression only the elevated level of GGT was an independent prognostic factor for severe steatosis. Steatosis is an important risk factor for the severity of liver disease in CHC patients. Among patients with genotype 1 hepatitis C virus infection and moderate alcohol intake, those with serum levels of GGT over two times the normal value are at high risk for severe steatosis.

Associated liver enzymes with hyperlipidemic profile in type 2 diabetes patients.

PubMed

Al-Jameil, Noura; Khan, Farah A; Arjumand, Sadia; Khan, Mohammad F; Tabassum, Hajera

2014-01-01

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia and is associated with dyslipidemia and disturbed liver function. Aim of the present work is to assess the liver enzymes and to find its association with hyperlipidemic profile in T2DM. Total of 157 subjects were studied and divided into two groups; diabetes (n=81) and non-diabetes (n=76). Various biochemical parameters like fasting glucose, post prandial glucose, HbA1c, total cholesterol (TC), triglycerides (Tg), high density lipoprotein cholesterol (HDL-C), alanine amino transferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transferase (GGT) were analyzed by ROCHE module Cobas 6000 (C501 & C601) analyzer, kits were procured by ROCHE diagnostics. Low density lipoprotein cholesterol (LDL-C) was estimated by Freidwald's formula. Statistical analysis was performed by applying student t test and Pearson's correlation coefficient, at 0.0001 and 0.05 level of significance, respectively. All the glycemic control parameters, lipid profile parameters except HDL-C and liver enzymes were found increased in diabetes group and significantly differ from non-diabetes group (p>0.0001). ALT showed significant positive correlation with fasting glucose, post prandial glucose, HbA1c, TC, Tg, LDL-C and GGT at p>0.05. AST showed very weak relation with all parameters while GGT was positively associated with fasting glucose, post prandial glucose, HbA1c, TC, Tg, LDL-C and ALT at p>0.05. In conclusion, T2DM incline to elevate liver enzymes, especially ALT and GGT were of significance. Routine screening of ALT and GGT in T2DM patients may assists early detection of liver abnormalities and to arrest the progress of disease.

The gamma-glutamyl transpeptidase to platelet ratio (GPR) predicts significant liver fibrosis and cirrhosis in patients with chronic HBV infection in West Africa.

PubMed

Lemoine, Maud; Shimakawa, Yusuke; Nayagam, Shevanthi; Khalil, Mustapha; Suso, Penda; Lloyd, Jo; Goldin, Robert; Njai, Harr-Freeya; Ndow, Gibril; Taal, Makie; Cooke, Graham; D'Alessandro, Umberto; Vray, Muriel; Mbaye, Papa Saliou; Njie, Ramou; Mallet, Vincent; Thursz, Mark

2016-08-01

Simple and inexpensive non-invasive fibrosis tests are highly needed but have been poorly studied in sub-Saharan Africa. Using liver histology as a gold standard, we developed a novel index using routine laboratory tests to predict significant fibrosis in patients with chronic HBV infection in The Gambia, West Africa. We prospectively assessed the diagnostic accuracy of the novel index, Fibroscan, aspartate transaminase-to-platelet ratio index (APRI), and Fib-4 in Gambian patients with CHB (training set) and also in French and Senegalese CHB cohorts (validation sets). Of 135 consecutive treatment-naïve patients with CHB who had liver biopsy, 39% had significant fibrosis (Metavir fibrosis stage ≥F2) and 15% had cirrhosis (F4). In multivariable analysis, gamma-glutamyl transpeptidase (GGT) and platelet count were independent predictors of significant fibrosis. Consequently, GGT-to-platelet ratio (GPR) was developed. In The Gambia, the area under the receiver operating characteristic curve (AUROC) of the GPR was significantly higher than that of APRI and Fib-4 to predict ≥F2, ≥F3 and F4. In Senegal, the AUROC of GPR was significantly better than Fib-4 and APRI for ≥F2 (0.73, 95% CI 0.59 to 0.86) and better than Fib-4 and Fibroscan for ≥F3 (0.93, 0.87 to 0.99). In France, the AUROC of GPR to diagnose ≥F2 (0.72, 95% CI 0.59 to 0.85) and F4 (0.87, 0.76 to 0.98) was equivalent to that of APRI and Fib-4. The GPR is a more accurate routine laboratory marker than APRI and Fib-4 to stage liver fibrosis in patients with CHB in West Africa. The GPR represents a simple and inexpensive alternative to liver biopsy and Fibroscan in sub-Saharan Africa. 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/

gamma-Hexachlorocyclohexane (gamma-HCH)

Integrated Risk Information System (IRIS)

gamma - Hexachlorocyclohexane ( gamma - HCH ) ; CASRN 58 - 89 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Asse

Unidentified Gamma-Ray Sources: Hunting Gamma-Ray Blazars

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

Massaro, F.; D'Abrusco, R.; Tosti, G.

2012-04-02

One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of the unidentified {gamma}-ray sources (UGSs). Despite the large improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one third of the Fermi-detected objects are still not associated to low energy counterparts. Recently, using the Wide-field Infrared Survey Explorer (WISE) survey, we discovered that blazars, the rarest class of Active Galactic Nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Basedmore » on this result, we designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated to the UGS sample of the second Fermi {gamma}-ray catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated to {gamma}-ray sources in the 2FGL catalog.« less

UNIDENTIFIED {gamma}-RAY SOURCES: HUNTING {gamma}-RAY BLAZARS

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

Massaro, F.; Ajello, M.; D'Abrusco, R.

2012-06-10

One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of unidentified {gamma}-ray sources (UGSs). Despite the major improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one-third of the Fermi-detected objects are still not associated with low-energy counterparts. Recently, using the Wide-field Infrared Survey Explorer survey, we discovered that blazars, the rarest class of active galactic nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Based on this result, wemore » designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated with the UGS sample of the second Fermi {gamma}-ray LAT catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart to each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated with {gamma}-ray sources in the 2FGL catalog.« less

Growth kinetics of gamma-prime precipitates in a directionally solidified eutectic, gamma/gamma-prime-delta

NASA Technical Reports Server (NTRS)

Tewari, S. N.

1976-01-01

A directionally solidified eutectic alloy (DSEA), of those viewed as potential candidates for the next generation of aircraft gas turbine blade materials, is studied for the gamma-prime growth kinetics, in the system Ni-Nb-Cr-Al, specifically: Ni-20 w/o Nb-6 w/o Cr-2.5 w/o Al gamma/gamma-prime-delta DSEA. Heat treatment, polishing and etching, and preparation for electron micrography are described, and the size distribution of gamma-prime phase following various anneals is plotted, along with gamma-prime growth kinetics in this specific DSEA, and the cube of gamma-prime particle size vs anneal time. Activation energies and coarsening kinetics are studied.

The neutron-gamma Feynman variance to mean approach: Gamma detection and total neutron-gamma detection (theory and practice)

NASA Astrophysics Data System (ADS)

Chernikova, Dina; Axell, Kåre; Avdic, Senada; Pázsit, Imre; Nordlund, Anders; Allard, Stefan

2015-05-01

Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma are evaluated experimentally for a weak 252Cf neutron-gamma source, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.

Inverse associations of total and decaffeinated coffee with liver enzyme levels in NHANES 1999–2010

PubMed Central

Xiao, Qian; Sinha, Rashmi; Graubard, Barry I.; Freedman, Neal D.

2014-01-01

Background Coffee may have hepatoprotective effects and higher coffee consumption has been associated inversely with levels of liver enzymatic markers. However, it is unclear whether decaffeinated coffee is also associated with liver enzymes. Methods The study population included 27,793 participants, age 20 or older, in the US National Health and Nutrition Examination Survey (1999–2010). Coffee intake was evaluated by 24-hour dietary recall. Serum levels of aminotransferase (ALT), aminotransferase (AST), alkaline phosphatase (ALP) and gamma glutamyl transaminase (GGT) were measured. We examined the relationship between coffee intake and enzymatic levels using weighted multiple variable logistic (abnormally elevated levels of enzymes) and linear regression (continuous enzymatic levels). Results Total coffee consumption was inversely associated with abnormal levels of all four liver enzymes and continuous levels of AST, ALP and GGT. Compared to those reporting no coffee consumption, participants reporting ≥3 cups per day had an odds ratio (OR) (95% confidence interval (CI)) of 0.75 (0.63, 0.89)), 0.82 (0.68, 0.98), 0.73 (0.55, 0.95) and 0.69 (0.57, 0.83) for abnormal levels of ALT, AST, ALP and GGT, respectively. Similar inverse associations were found with decaffeinated coffee intake and abnormal levels of ALT (OR≥2 vs 0 cup/d: 0.62 (0.41, 0.94)), AST (0.74 (0.49, 1.11)), and GGT (0.70, 0.49–1.00). Conclusion Higher intakes of coffee, regardless of its caffeine content, were associated with lower levels of liver enzymes. PMID:25124935

Very high-energy gamma rays from gamma-ray bursts.

PubMed

Chadwick, Paula M

2007-05-15

Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.

[Results transferability on RXL, ARX, X-Pand, BN2 (Dade Behring) and modular DP (Roche Diagnostics) analysers: application to component assays of fibrotest and Actitest].

PubMed

Imbert-Bismut, F; Messous, D; Raoult, A; Poynard, T; Bertrand, J J; Marie, P A; Louis, V; Audy, C; Thouy, J M; Hainque, B; Piton, A

2005-01-01

The follow up of patients with chronic liver diseases and the data from multicentric clinical studies are affected by the variability of assay results for the same parameter between the different laboratories. Today, the main objective in clinical chemistry throughout the world is to harmonise the assay results between the laboratories after the confirmation of their traceability, in relation to defined reference systems. In this context, the purpose of our study was to verify the homogeneity of haptoglobin, apolipoprotein A1, total bilirubin, GGT activity, ALAT activity results, which are combined in Fibrotest and Actitest, between Dimension Analysers RXL, ARX and X-PAND (Dade Behring Society). Moreover, we verified the transferability of Fibrotest and Actitest results between the RXL, and either the BN2 (haptoglobin and apolipoprotein A1) or the Modular DP (total bilirubin, GGT and ALAT activity concentrations). The serum samples from 150 hospitalised patients were analysed on the different analysers. Specific protein assays were calibrated using solutions standardised against reference material on Dimension and BN2 analysers. Total bilirubin assays were performed by a diazoreaction on Dimension and Modular DP analysers. The GGT and ALAT activity measurements on the Dimension analysers were performed in accordance with the reference methods defined by the International Federation of Clinical Chemisty and Laboratory Medicine (IFCC). On the Modular, enzyme activity measurements were performed according to the Szasz method (L-gamma- glutamyl-4-nitroanilide as substrate) modified by Persijn and van der Slik (L-gamma- glutamyl-3-carboxy- 4-nitroanilide as substrat) for GGT and according to the IFCC specifications for ALAT. The methods of enzymatic activity measurement were calibrated on the Modular only. Liver fibrosis and necroinflammatory activity indices were determined using calculation algorithms, after having adjusted each component's result of Fibrotest and

Pretreatment data is highly predictive of liver chemistry signals in clinical trials

PubMed Central

Cai, Zhaohui; Bresell, Anders; Steinberg, Mark H; Silberg, Debra G; Furlong, Stephen T

2012-01-01

Purpose The goal of this retrospective analysis was to assess how well predictive models could determine which patients would develop liver chemistry signals during clinical trials based on their pretreatment (baseline) information. Patients and methods Based on data from 24 late-stage clinical trials, classification models were developed to predict liver chemistry outcomes using baseline information, which included demographics, medical history, concomitant medications, and baseline laboratory results. Results Predictive models using baseline data predicted which patients would develop liver signals during the trials with average validation accuracy around 80%. Baseline levels of individual liver chemistry tests were most important for predicting their own elevations during the trials. High bilirubin levels at baseline were not uncommon and were associated with a high risk of developing biochemical Hy’s law cases. Baseline γ-glutamyltransferase (GGT) level appeared to have some predictive value, but did not increase predictability beyond using established liver chemistry tests. Conclusion It is possible to predict which patients are at a higher risk of developing liver chemistry signals using pretreatment (baseline) data. Derived knowledge from such predictions may allow proactive and targeted risk management, and the type of analysis described here could help determine whether new biomarkers offer improved performance over established ones. PMID:23226004

Gamma-sky.net: Portal to the gamma-ray sky

NASA Astrophysics Data System (ADS)

Voruganti, Arjun; Deil, Christoph; Donath, Axel; King, Johannes

2017-01-01

http://gamma-sky.net is a novel interactive website designed for exploring the gamma-ray sky. The Map View portion of the site is powered by the Aladin Lite sky atlas, providing a scalable survey image tesselated onto a three-dimensional sphere. The map allows for interactive pan and zoom navigation as well as search queries by sky position or object name. The default image overlay shows the gamma-ray sky observed by the Fermi-LAT gamma-ray space telescope. Other survey images (e.g. Planck microwave images in low/high frequency bands, ROSAT X-ray image) are available for comparison with the gamma-ray data. Sources from major gamma-ray source catalogs of interest (Fermi-LAT 2FHL, 3FGL and a TeV source catalog) are overlaid over the sky map as markers. Clicking on a given source shows basic information in a popup, and detailed pages for every source are available via the Catalog View component of the website, including information such as source classification, spectrum and light-curve plots, and literature references. We intend for gamma-sky.net to be applicable for both professional astronomers as well as the general public. The website started in early June 2016 and is being developed as an open-source, open data project on GitHub (https://github.com/gammapy/gamma-sky). We plan to extend it to display more gamma-ray and multi-wavelength data. Feedback and contributions are very welcome!

Construction of environmental risk score beyond standard linear models using machine learning methods: application to metal mixtures, oxidative stress and cardiovascular disease in NHANES.

PubMed

Park, Sung Kyun; Zhao, Zhangchen; Mukherjee, Bhramar

2017-09-26

There is growing concern of health effects of exposure to pollutant mixtures. We initially proposed an Environmental Risk Score (ERS) as a summary measure to examine the risk of exposure to multi-pollutants in epidemiologic research considering only pollutant main effects. We expand the ERS by consideration of pollutant-pollutant interactions using modern machine learning methods. We illustrate the multi-pollutant approaches to predicting a marker of oxidative stress (gamma-glutamyl transferase (GGT)), a common disease pathway linking environmental exposure and numerous health endpoints. We examined 20 metal biomarkers measured in urine or whole blood from 6 cycles of the National Health and Nutrition Examination Survey (NHANES 2003-2004 to 2013-2014, n = 9664). We randomly split the data evenly into training and testing sets and constructed ERS's of metal mixtures for GGT using adaptive elastic-net with main effects and pairwise interactions (AENET-I), Bayesian additive regression tree (BART), Bayesian kernel machine regression (BKMR), and Super Learner in the training set and evaluated their performances in the testing set. We also evaluated the associations between GGT-ERS and cardiovascular endpoints. ERS based on AENET-I performed better than other approaches in terms of prediction errors in the testing set. Important metals identified in relation to GGT include cadmium (urine), dimethylarsonic acid, monomethylarsonic acid, cobalt, and barium. All ERS's showed significant associations with systolic and diastolic blood pressure and hypertension. For hypertension, one SD increase in each ERS from AENET-I, BART and SuperLearner were associated with odds ratios of 1.26 (95% CI, 1.15, 1.38), 1.17 (1.09, 1.25), and 1.30 (1.20, 1.40), respectively. ERS's showed non-significant positive associations with mortality outcomes. ERS is a useful tool for characterizing cumulative risk from pollutant mixtures, with accounting for statistical challenges such as high

Resonance production in. gamma gamma. collisions

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

Renard, F.M.

1983-04-01

The processes ..gamma gamma.. ..-->.. hadrons can be depicted as follows. One photon creates a q anti q pair which starts to evolve; the other photon can either (A) make its own q anti q pair and the (q anti q q anti q) system continue to evolve or (B) interact with the quarks of the first pair and lead to a modified (q anti q) system in interaction with C = +1 quantum numbers. A review of the recent theoretical activity concerning resonance production and related problems is given under the following headings: hadronic C = +1 spectroscopy (qmore » anti q, qq anti q anti q, q anti q g, gg, ggg bound states and mixing effects); exclusive ..gamma gamma.. processes (generalities, unitarized Born method, VDM and QCD); total cross section (soft and hard contributions); q/sup 2/ dependence of soft processes (soft/hard separation, 1/sup +- +/ resonances); and polarization effects. (WHK)« less

Effects of Kombucha on oxidative stress induced nephrotoxicity in rats

PubMed Central

2009-01-01

Background Trichloroethylene (TCE) may induce oxidative stress which generates free radicals and alters antioxidants or oxygen-free radical scavenging enzymes. Methods Twenty male albino rats were divided into four groups: (1) the control group treated with vehicle, (2) Kombucha (KT)-treated group, (3) TCE-treated group and (4) KT/TCE-treated group. Kidney lipid peroxidation, glutathione content, nitric oxide (NO) and total blood free radical concentrations were evaluated. Serum urea, creatinine level, gamma-glutamyl transferase (GGT) and lactate dehydrogenase (LDH) activities were also measured. Results TCE administration increased the malondiahyde (MDA) and NO contents in kidney, urea and creatinine concentrations in serum, total free radical level in blood and GGT and LDH activities in serum, whereas it decreased the glutathione (GSH) level in kidney homogenate. KT administration significantly improved lipid peroxidation and oxidative stress induced by TCE. Conclusion The present study indicates that Kombucha may repair damage caused by environmental pollutants such as TCE and may be beneficial to patient suffering from renal impairment. PMID:19943946

Effects of Kombucha on oxidative stress induced nephrotoxicity in rats.

PubMed

Gharib, Ola Ali

2009-11-27

Trichloroethylene (TCE) may induce oxidative stress which generates free radicals and alters antioxidants or oxygen-free radical scavenging enzymes. Twenty male albino rats were divided into four groups: (1) the control group treated with vehicle, (2) Kombucha (KT)-treated group, (3) TCE-treated group and (4) KT/TCE-treated group. Kidney lipid peroxidation, glutathione content, nitric oxide (NO) and total blood free radical concentrations were evaluated. Serum urea, creatinine level, gamma-glutamyl transferase (GGT) and lactate dehydrogenase (LDH) activities were also measured. TCE administration increased the malondiahyde (MDA) and NO contents in kidney, urea and creatinine concentrations in serum, total free radical level in blood and GGT and LDH activities in serum, whereas it decreased the glutathione (GSH) level in kidney homogenate. KT administration significantly improved lipid peroxidation and oxidative stress induced by TCE. The present study indicates that Kombucha may repair damage caused by environmental pollutants such as TCE and may be beneficial to patient suffering from renal impairment.

γ-Glutamyl transferase 7 is a novel regulator of glioblastoma growth.

PubMed

Bui, Timothy T; Nitta, Ryan T; Kahn, Suzana A; Razavi, Seyed-Mostafa; Agarwal, Maya; Aujla, Parvir; Gholamin, Sharareh; Recht, Lawrence; Li, Gordon

2015-04-07

Glioblastoma (GBM) is the most malignant primary brain tumor in adults, with a median survival time of one and a half years. Traditional treatments, including radiation, chemotherapy, and surgery, are not curative, making it imperative to find more effective treatments for this lethal disease. γ-Glutamyl transferase (GGT) is a family of enzymes that was shown to control crucial redox-sensitive functions and to regulate the balance between proliferation and apoptosis. GGT7 is a novel GGT family member that is highly expressed in brain and was previously shown to have decreased expression in gliomas. Since other members of the GGT family were found to be altered in a variety of cancers, we hypothesized that GGT7 could regulate GBM growth and formation. To determine if GGT7 is involved in GBM tumorigenesis, we modulated GGT7 expression in two GBM cell lines (U87-MG and U138) and monitored changes in tumorigenicity in vitro and in vivo. We demonstrated for the first time that GBM patients with low GGT7 expression had a worse prognosis and that 87% (7/8) of primary GBM tissue samples showed a 2-fold decrease in GGT7 expression compared to normal brain samples. Exogenous expression of GGT7 resulted in a 2- to 3-fold reduction in proliferation and anchorage-independent growth under minimal growth conditions (1% serum). Decreasing GGT7 expression using either short interfering RNA or short hairpin RNA consistently increased proliferation 1.5- to 2-fold. In addition, intracranial injections of U87-MG cells with reduced GGT7 expression increased tumor growth in mice approximately 2-fold, and decreased mouse survival. To elucidate the mechanism by which GGT7 regulates GBM growth, we analyzed reactive oxygen species (ROS) levels in GBM cells with modulated GGT7 expression. We found that enhanced GGT7 expression reduced ROS levels by 11-33%. Our study demonstrates that GGT7 is a novel player in GBM growth and that GGT7 can play a critical role in tumorigenesis by regulating

A dose-up of ursodeoxycholic acid decreases transaminases in hepatitis C patients

PubMed Central

Sato, Shuichi; Miyake, Tatsuya; Tobita, Hiroshi; Oshima, Naoki; Ishine, Junichi; Hanaoka, Takuya; Amano, Yuji; Kinoshita, Yoshikazu

2009-01-01

AIM: To examine whether a dose-up to 900 mg of ursodeoxycholic acid (UDCA) decreases transaminases in hepatitis C patients. METHODS: From January to December 2007, patients with chronic hepatitis C or compensated liver cirrhosis with hepatitis C virus (HCV) (43-80 years old) showing positive serum HCV-RNA who had already taken 600 mg/d of UDCA were recruited into this study. Blood parameters were examined at 4, 8 and 24 wk after increasing the dose of oral UDCA from 600 to 900 mg/d. RESULTS: Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT) levels were significantly decreased following the administration of 900 mg/d as compared to 600 mg/d. The decrease in ALT from immediately before the dose-up of UDCA to 8 wk after the dose-up was 14.3 IU/L, while that for AST was 10.5 IU/L and for GGT was 9.8 IU/L. Platelet count tended to increase after the dose-up of UDCA, although it did not show a statistically significant level (P = 0.05). Minor adverse events were observed in 3 cases, although no drop-outs from the study occurred. CONCLUSION: Oral administration of 900 mg/d of UDCA was more effective than 600 mg/d for reducing ALT, AST, and GGT levels in patients with HCV-related chronic liver disease. PMID:19522030

Modeled Perfluorooctanoic Acid (PFOA) Exposure and Liver Function in a Mid-Ohio Valley Community.

PubMed

Darrow, Lyndsey A; Groth, Alyx C; Winquist, Andrea; Shin, Hyeong-Moo; Bartell, Scott M; Steenland, Kyle

2016-08-01

Perfluorooctanoic acid (PFOA or C8) has hepatotoxic effects in animals. Cross-sectional epidemiologic studies suggest PFOA is associated with liver injury biomarkers. We estimated associations between modeled historical PFOA exposures and liver injury biomarkers and medically validated liver disease. Participants completed surveys during 2008-2011 reporting demographic, medical, and residential history information. Self-reported liver disease, including hepatitis, fatty liver, enlarged liver and cirrhosis, was validated with healthcare providers. Alanine aminotransferase (ALT), γ-glutamyltransferase (GGT) and direct bilirubin, markers of liver toxicity, were obtained from blood samples collected in the C8 Health Project (2005-2006). Historically modeled PFOA exposure, estimated using environmental fate and transport models and participant residential histories, was analyzed in relation to liver biomarkers (n = 30,723, including 1,892 workers) and liver disease (n = 32,254, including 3,713 workers). Modeled cumulative serum PFOA was positively associated with ALT levels (p for trend < 0.0001), indicating possible liver toxicity. An increase from the first to the fifth quintile of cumulative PFOA exposure was associated with a 6% increase in ALT levels (95% CI: 4, 8%) and a 16% increased odds of having above-normal ALT (95% CI: odds ratio: 1.02, 1.33%). There was no indication of association with either elevated direct bilirubin or GGT; however, PFOA was associated with decreased direct bilirubin. We observed no evidence of an effect of cumulative exposure (with or without a 10-year lag) on all liver disease (n = 647 cases), nor on enlarged liver, fatty liver, and cirrhosis only (n = 427 cases). Results are consistent with previous cross-sectional studies showing association between PFOA and ALT, a marker of hepatocellular damage. We did not observe evidence that PFOA increases the risk of clinically diagnosed liver disease. Darrow LA, Groth AC, Winquist A, Shin HM

Does laboratory automation for the preanalytical phase improve data quality?

PubMed

Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Montagnana, Martina; Brocco, Giorgio; Voi, Monica; Picheth, Geraldo; Guidi, Gian Cesare

2013-10-01

Our aim was to evaluate whether automation for the preanalytical phase improves data quality. Blood from 100 volunteers was collected into two vacuum tubes. One sample from each volunteer was respectively assigned to (G1) traditional processing, starting with centrifugation at 1200 g for 10 min, and (G2) the MODULAR PRE-ANALYTICALS EVO-MPA system. The routine clinical chemistry tests were performed in duplicate on the same instrument Cobas 6000 module. G1 samples were uncapped manually and immediately placed into the instrument. G2 samples were directly fed from the MPA system to the instrument without further staff intervention. At the end, (1) the G1 samples were stored for 6 h at 4 °C as prescribed in our accredited laboratory and (2) the G2 samples were stored for 6 h in the MPA output buffer. Results from G1 and G2, before and after storage, were compared. Significant increases were observed in G1 compared with G2 samples as follows: (1) before storage for alkaline phosphatase (ALP), lactate dehydrogenase (LDH), phosphate (P), magnesium (MG), iron (FE), and hemolysis index and (2) after storage for total cholesterol (COL), triglycerides (TG), total protein (TP), albumin (ALB), blood urea nitrogen (BUN), creatinine (CRE), uric acid (UA), ALP, pancreatic amylase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), g-glutamyltransferase (GGT), LDH, creatine kinase (CK), calcium (CA), FE, sodium (NA), potassium (K), and hemolysis index. Moreover, significant increases were observed in (3) G1-after versus G1-before storage samples for COL, high-density lipoprotein cholesterol, TG, TP, ALB, BUN, CRE, UA, AST, ALT, GGT, LDH, P, CA, MG, FE, NA, K, and hemolysis index and (4) G2-after versus G2-before storage only for BUN, AST, LDH, P, and CA. In conclusion, our results show that the MPA system improves the quality of laboratory testing.

Genetic variations of the NPC1L1 gene associated with hepatitis C virus (HCV) infection and biochemical characteristics of HCV patients in China.

PubMed

Zhang, A-Mei; Zhang, Cheng-Lin; Song, Yuzhu; Zhao, Ping; Feng, Yue; Wang, Binghui; Li, Zheng; Liu, Li; Xia, Xueshan

2016-12-01

About 2% of the world population is infected with hepatitis C virus (HCV), a leading cause of hepatic cirrhosis and hepatocellular carcinoma. The Niemann-Pick C1-like 1 cholesterol absorption receptor (NPC1L1) was recently identified to be an important factor for HCV entry into host cells. Whether genetic variations of the NPC1L1 gene are associated with HCV infection is unknown. In this study, five single nucleotide polymorphisms (SNPs) of the NPC1L1 gene were analyzed in 261 HCV-infected individuals and 265 general controls from Yunnan Province, China. No significant differences were identified in genotypes or alleles of the SNPs between the two groups. After constructing haplotypes based on the five SNPs, a significant difference between HCV-infected individuals and general controls was shown for two haplotypes. Haplotype GCCTT appeared to be a protective factor and haplotype GCCCT was a risk factor for HCV-infected individuals. Genotypes of four SNPs correlated with biochemical characteristics of HCV-infected persons. Genotypes of SNPs rs799444 and rs2070607 were correlated with total bilirubin. Genotype TT of rs917098 was a risk factor for the gamma-glutamyltransferase level. Furthermore, HCV-infected individuals carrying genotype GG of rs41279633 showed statistically higher gamma-glutamyltransferase levels than HCV-infected persons with GT and TT. The results of this study identified the association between genetic susceptibility of the NPC1L1 gene and HCV infection, as well as biochemical characteristics of HCV-infected persons in Yunnan, China. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

NASA Astrophysics Data System (ADS)

Kheymits, M. D.; Leonov, A. A.; Zverev, V. G.; Galper, A. M.; Arkhangelskaya, I. V.; Arkhangelskiy, A. I.; Suchkov, S. I.; Topchiev, N. P.; Yurkin, Yu T.; Bakaldin, A. V.; Dalkarov, O. D.

2016-02-01

The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work.

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

NASA Technical Reports Server (NTRS)

Galper, A.M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A.I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu. V.;

Cosmic Gamma-Rays

Science.gov Websites

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Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

NASA Technical Reports Server (NTRS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.;

The use of iohexol in pediatric urography: a comparative study with meglumine diatrizoate.

PubMed

Bani, E; Federighi, F; Ghio, R; Marchitiello, M; Galigani, P; Palla, R

1985-01-01

In a prospective study the nephrotoxicity of iohexol, a new non-ionic contrast medium, was compared with meglumine diatrizoate. Plasma creatinine, BUN, creatinine clearance, urinalysis and the urinary excretion of N-acetyl glucosaminidase (NAG), gamma glutamyl transpeptidase (GGT) and muramidase (MU) were determined prior to and following intravenous pyelography. A significant rise in the enzyme excretion was observed in patients who received iohexol and diatrizoate. Statistical analysis failed to demonstrate any difference in nephrotoxicity between the two iodinated contrast media.

Assessing alcohol intake & its dose-dependent effects on liver enzymes by 24-h recall and questionnaire using NHANES 2001-2010 data

DOE PAGES

Agarwal, Sanjiv; Fulgoni, III, Victor L.; Lieberman, Harris R.

2016-06-22

Alcohol is a significant component of the diet with dose-dependent risks and benefits. High doses of alcohol damage the liver and early symptoms of liver disease include changes in routinely assessed liver enzymes. Less is known regarding the mechanisms responsible for the benefits of moderate alcohol consumption, including their effects on the liver. The objectives of this study were to examine alcohol’s dose-dependent effects on markers of liver function (alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), and bilirubin), as well as to compare the different methods of assessing alcohol intake using NHANES 2001–2010 adultmore » data (N =24,807). Three methods were used to estimate alcohol intake from all volunteers: 24-h recall; the National Cancer Institute (NCI) method of usual intake; and a specific alcohol intake questionnaire. Mean alcohol intake by 24-h recall, NCI method and questionnaire was 41.0 ± 0.8 g/d, 10.9 ± 0.2 g/d and 11.0 ± 0.2 g/d, respectively. Alcohol consumers had significantly lower levels of ALP and higher levels of AST, GGT and bilirubin compared to non-consumers (P < 0.01) and activities of ALT, AST, and GGT increased and of ALP decreased as alcohol intake increased, regardless of intake assessment method used. The most sensitive measure of alcohol consumption was GGT. Since alcohol had a graded linear effect on several liver enzymes, including at low and moderate doses, benefits as well as risks of alcohol intake may be related to liver function. In conclusion, since the NCI method and alcohol questionnaire yielded very similar alcohol intake estimates, this study cross-validated these methods and demonstrated the robustness of the NCI method for estimating intake of irregularly consumed foods.« less

Assessing alcohol intake & its dose-dependent effects on liver enzymes by 24-h recall and questionnaire using NHANES 2001-2010 data

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

Agarwal, Sanjiv; Fulgoni, III, Victor L.; Lieberman, Harris R.

Alcohol is a significant component of the diet with dose-dependent risks and benefits. High doses of alcohol damage the liver and early symptoms of liver disease include changes in routinely assessed liver enzymes. Less is known regarding the mechanisms responsible for the benefits of moderate alcohol consumption, including their effects on the liver. The objectives of this study were to examine alcohol’s dose-dependent effects on markers of liver function (alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), and bilirubin), as well as to compare the different methods of assessing alcohol intake using NHANES 2001–2010 adultmore » data (N =24,807). Three methods were used to estimate alcohol intake from all volunteers: 24-h recall; the National Cancer Institute (NCI) method of usual intake; and a specific alcohol intake questionnaire. Mean alcohol intake by 24-h recall, NCI method and questionnaire was 41.0 ± 0.8 g/d, 10.9 ± 0.2 g/d and 11.0 ± 0.2 g/d, respectively. Alcohol consumers had significantly lower levels of ALP and higher levels of AST, GGT and bilirubin compared to non-consumers (P < 0.01) and activities of ALT, AST, and GGT increased and of ALP decreased as alcohol intake increased, regardless of intake assessment method used. The most sensitive measure of alcohol consumption was GGT. Since alcohol had a graded linear effect on several liver enzymes, including at low and moderate doses, benefits as well as risks of alcohol intake may be related to liver function. In conclusion, since the NCI method and alcohol questionnaire yielded very similar alcohol intake estimates, this study cross-validated these methods and demonstrated the robustness of the NCI method for estimating intake of irregularly consumed foods.« less

[Liver enzymes elevation: etiologic study and efficiency of a single-act office visit].

PubMed

Bendezú García, Rogger Álvaro; Casado Martín, Marta; Lázaro Sáez, Marta; Patrón Román, Gustavo Óliver; Gálvez Miras, Alejandra; Rodríguez Laiz, Gonzalo P; González Sánchez, Mercedes; Vega Sáenz, José Luis

2013-01-01

Liver enzyme (LE) elevation is a common finding in routine blood analysis. There is very little information on the most prevalent causes of these alterations in our population. In addition, a number of tests and several visits to the specialist are required to reach a diagnosis. For these reasons, we designed a protocol to streamline the evaluation of patients with LE elevations in a single-act office visit. From March 2008 until June 2010, we studied all patients with incidental LE elevation (isolated transaminase elevation, combined elevation of alkaline phosphatase [FA] and gamma-glutamyl transpeptidase [GGT], or isolated elevation of GGT) who were referred by their primary care physicians. At the time of referral, a complete biochemistry analysis was performed (LE, viral serology, autoantibodies, ceruloplasmin, iron metabolism, alpha-1-antitrypsin and thyroid hormones) and the patients underwent an abdominal ultrasound scan on the day of the office evaluation by the hepatologist. A total of 427 patients were included in our study. The most common cause of transaminase elevation was non-alcoholic fatty liver disease (NAFLD) (40%), followed by alcohol intake (17%), and hepatitis C virus infection (13%). Elevated GGT levels were most commonly related to NAFLD (30%), closely followed by alcohol intake (27%), and hepatotoxicity (8%). Combined elevation of GGT and FA was associated with NAFLD (21%), alcohol (17%), and hepatotoxicity (11%). Self-limited elevation was seen in 9% of the patients and we could not identify a definite cause in 11%. A definitive diagnosis was reached in 79% of the patients. The single-act office visit has proven to be efficient, yielding a diagnosis in most of the patients. The most common cause of elevated LE was NAFLD. Transaminase elevation must be confirmed before a more thorough work-up is started. Copyright © 2013 Elsevier España, S.L. and AEEH y AEG. All rights reserved.

Influence of a Virgin Olive Oil versus Butter Plus Cholesterol-Enriched Diet on Testicular Enzymatic Activities in Adult Male Rats

PubMed Central

Segarra, Ana Belén; Martínez-Cañamero, Magdalena; Ramírez-Sánchez, Manuel

2017-01-01

The aim of the present work was to improve our knowledge on the mechanisms underlying the beneficial or deleterious effects on testicular function of the so-called Mediterranean and Western diet by analyzing glutamyl aminopeptidase (GluAP), gamma glutamyl transpeptidase (GGT) and dipeptidyl peptidase IV (DPP IV) activities in testis, as enzymes involved in testicular function. Male Wistar rats (6 months old) were fed for 24 weeks with three different diets: standard (S), an S diet supplemented with virgin-olive-oil (20%) (VOO), or a S diet enriched with butter (20%) plus cholesterol (0.1%) (Bch). At the end of the experimental period, plasma lipid profiled (total triglycerides, total cholesterol and cholesterol fractions (HDL, LDL and VDL)) were measured. Enzymatic activities were determined by fluorimetric methods in soluble (sol) and membrane-bound (mb) fractions of testicular tissue using arylamide derivatives as substrates. Results indicated an increase in plasmatic triglycerides, total cholesterol, LDL and VLDL in Bch. A significant increase of mb GluAP and GGT activities was also found in this diet in comparison with the other two diets. Furthermore, significant and positive correlations were established between these activities and plasma triglycerides and/or total cholesterol. These results support a role for testicular GluAP and GGT activities in the effects of saturated fat (Western diet) on testicular functions. In contrast, VOO increased sol DPP IV activity in comparison with the other two diets, which support a role for this activity in the effects of monounsaturated fat (Mediterranean diet) on testicular function. The present results strongly support the influence of fatty acids and cholesterol on testicular GluAP and GGT activities and also provide support that the reported beneficial influence of the Mediterranean diet in male fertility may be mediated in part by an increase of testicular sol DPP IV activity. PMID:28777292

Influence of a Virgin Olive Oil versus Butter Plus Cholesterol-Enriched Diet on Testicular Enzymatic Activities in Adult Male Rats.

PubMed

Domínguez-Vías, Germán; Segarra, Ana Belén; Martínez-Cañamero, Magdalena; Ramírez-Sánchez, Manuel; Prieto, Isabel

2017-08-04

The aim of the present work was to improve our knowledge on the mechanisms underlying the beneficial or deleterious effects on testicular function of the so-called Mediterranean and Western diet by analyzing glutamyl aminopeptidase (GluAP), gamma glutamyl transpeptidase (GGT) and dipeptidyl peptidase IV (DPP IV) activities in testis, as enzymes involved in testicular function. Male Wistar rats (6 months old) were fed for 24 weeks with three different diets: standard (S), an S diet supplemented with virgin-olive-oil (20%) (VOO), or a S diet enriched with butter (20%) plus cholesterol (0.1%) (Bch). At the end of the experimental period, plasma lipid profiled (total triglycerides, total cholesterol and cholesterol fractions (HDL, LDL and VDL)) were measured. Enzymatic activities were determined by fluorimetric methods in soluble (sol) and membrane-bound (mb) fractions of testicular tissue using arylamide derivatives as substrates. Results indicated an increase in plasmatic triglycerides, total cholesterol, LDL and VLDL in Bch. A significant increase of mb GluAP and GGT activities was also found in this diet in comparison with the other two diets. Furthermore, significant and positive correlations were established between these activities and plasma triglycerides and/or total cholesterol. These results support a role for testicular GluAP and GGT activities in the effects of saturated fat (Western diet) on testicular functions. In contrast, VOO increased sol DPP IV activity in comparison with the other two diets, which support a role for this activity in the effects of monounsaturated fat (Mediterranean diet) on testicular function. The present results strongly support the influence of fatty acids and cholesterol on testicular GluAP and GGT activities and also provide support that the reported beneficial influence of the Mediterranean diet in male fertility may be mediated in part by an increase of testicular sol DPP IV activity.

Optical gamma thermometer

DOEpatents

Koster, Glen Peter; Xia, Hua; Lee, Boon Kwee

2013-08-06

An optical gamma thermometer includes a metal mass having a temperature proportional to a gamma flux within a core of a nuclear reactor, and an optical fiber cable for measuring the temperature of the heated metal mass. The temperature of the heated mass may be measured by using one or more fiber grating structures and/or by using scattering techniques, such as Raman, Brillouin, and the like. The optical gamma thermometer may be used in conjunction with a conventional reactor heat balance to calibrate the local power range monitors over their useful in-service life. The optical gamma thermometer occupies much less space within the in-core instrument tube and costs much less than the conventional gamma thermometer.

Implications of Gamma-Ray Transparency Constraints in Blazars: Minimum Distances and Gamma-Ray Collimation

NASA Technical Reports Server (NTRS)

Becker, Peter A.; Kafatos, Menas

1995-01-01

We develop a general expression for the gamma - gamma absorption coefficient, alpha(sub gamma(gamma)) for gamma-rays propagating in an arbitrary direction at an arbitrary point in space above an X-ray-emitting accretion disk. The X-ray intensity is assumed to vary as a power law in energy and radius between the outer disk radius, R(sub 0), and the inner radius, R(sub ms) which is the radius of marginal stability for a Schwarzschild black hole. We use our result for alpha(sub gamma(gamma)) to calculate the gamma - gamma optical depth, tau(sub gamma(gamma)) for gamma - rays created at height z and propagating at angle Phi relative to the disk axis, and we show that for Phi = 0 and z greater than or approx equal to R(sub 0), tau(sub gamma(gamma)) proportional to Epsilon(sup alpha)z(sup -2(alpha) - 3), where alpha is the X-ray spectral index and Epsilon is the gamma - ray energy. As an application, we use our formalism to compute the minimum distance between the central black hole and the site of production of the gamma-rays detected by EGRET during the 1991 June flare of 3C 279. In order to obtain an upper limit, we assume that all of the X-rays observed contemporaneously by Ginga were emitted by the disk. Our results suggest that the observed gamma - rays may have originated within less than or approx equal to 45 GM/sq c from a black hole of mass greater than or approx equal to 10(exp 9) solar mass, perhaps in active plasma located above the central funnel of the accretion disk. This raises the possibility of establishing a direct connection between the production of the observed gamma - rays and the accretion of material onto the black hole. We also consider the variation of the optical depth as a function of the angle of propagation Phi. Our results indicate that the "focusing" of the gamma - rays along the disk axis due to pair production is strong enough to explain the observed degree of alignment in blazar sources. If the gamma - rays are produced isotropically

Design and performance of the GAMMA-400 gamma-ray telescope for dark matter searches

NASA Astrophysics Data System (ADS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu. V.; Kaplin, V. A.; Kachanov, V. A.; Kheymits, M. D.; Leonov, A. A.; Longo, F.; Mazets, E. P.; Maestro, P.; Marrocchesi, P.; Mereminskiy, I. A.; Mikhailov, V. V.; Moiseev, A. A.; Mocchiutti, E.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu.; Papini, P.; Picozza, P.; Rodin, V. G.; Runtso, M. F.; Sparvoli, R.; Spillantini, P.; Suchkov, S. I.; Tavani, M.; Topchiev, N. P.; Vacchi, A.; Vannuccini, E.; Yurkin, Yu. T.; Zampa, N.; Zverev, V. G.; Zirakashvili, V. N.

2013-02-01

The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ~0.01° (Eγ > 100 GeV), the energy resolution ~1% (Eγ > 10 GeV), and the proton rejection factor ~106. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

Increase in neutrophil Fc gamma receptor I expression following interferon gamma treatment in rheumatoid arthritis.

PubMed Central

Goulding, N J; Knight, S M; Godolphin, J L; Guyre, P M

1992-01-01

The therapeutic potential of interferon gamma (IFN gamma) in a number of disease states is still being explored, but progress is hampered by the lack of a suitable measure of in vivo biological activity. To assess the in vivo biological effects of recombinant human IFN gamma (rhIFN gamma), 14 patients were studied in a randomised, prospective, double blind, placebo controlled trial of this cytokine for the treatment of rheumatoid arthritis. The levels of Fc gamma receptors on peripheral blood neutrophils were measured at baseline and after 21 days of once daily, subcutaneous injections of rhIFN gamma or placebo. An induction of neutrophil Fc gamma receptor type I (Fc gamma RI) was seen in the group of patients receiving recombinant human rhIFN gamma but not in those receiving placebo. No change in the expression of Fc gamma RII or Fc gamma RIII was detected. The amount of induction of Fc gamma RI detected on the neutrophils of patients receiving rhIFN gamma did not correlate with clinical measures of response at either 21 days or at the end of the study (24 weeks). No significant clinical responses were observed in the rhIFN gamma group at these times. These data confirm that the reported in vitro effect of IFN gamma on human neutrophil Fc receptor expression can be reproduced in vivo. PMID:1534001

Increase in neutrophil Fc gamma receptor I expression following interferon gamma treatment in rheumatoid arthritis.

PubMed

Goulding, N J; Knight, S M; Godolphin, J L; Guyre, P M

1992-04-01

The therapeutic potential of interferon gamma (IFN gamma) in a number of disease states is still being explored, but progress is hampered by the lack of a suitable measure of in vivo biological activity. To assess the in vivo biological effects of recombinant human IFN gamma (rhIFN gamma), 14 patients were studied in a randomised, prospective, double blind, placebo controlled trial of this cytokine for the treatment of rheumatoid arthritis. The levels of Fc gamma receptors on peripheral blood neutrophils were measured at baseline and after 21 days of once daily, subcutaneous injections of rhIFN gamma or placebo. An induction of neutrophil Fc gamma receptor type I (Fc gamma RI) was seen in the group of patients receiving recombinant human rhIFN gamma but not in those receiving placebo. No change in the expression of Fc gamma RII or Fc gamma RIII was detected. The amount of induction of Fc gamma RI detected on the neutrophils of patients receiving rhIFN gamma did not correlate with clinical measures of response at either 21 days or at the end of the study (24 weeks). No significant clinical responses were observed in the rhIFN gamma group at these times. These data confirm that the reported in vitro effect of IFN gamma on human neutrophil Fc receptor expression can be reproduced in vivo.

Gamma Knife

MedlinePlus

... equipment? How is safety ensured? What is this equipment used for? The Gamma Knife® and its associated ... in size. top of page How does the equipment work? The Gamma Knife® utilizes a technique called ...

[Hereditary fructose intolerance (HFI) as cause of isolated gamma GT rise in a 5-year old boy with hepatomegaly].

PubMed

Wössmann, W; Wiemann, J; Körber, F; Gortner, L

2000-01-01

The diagnosis of HFI is easily missed during childhood. It should be suspected in children presenting with hepatomegaly and an isolated increase in GGT. A carefully taken nutritional history forms the basis of the diagnosis of HFI which can be confirmed by molecular analysis with a sensitivity of > 95%. I.v. fructose tolerance tests and liver biopsies often can be omitted.

Gamma-400 Science Objectives Built on the Current HE Gamma-Ray and CR Results

NASA Technical Reports Server (NTRS)

Moiseev, Alexander; Mitchell, John; Thompson, David

2012-01-01

The main scientific interest of the Russian Gamma-400 team: Observe gamma-rays above approximately 50 GeV with excellent energy and angular resolution with the goals of: (1) Studying the fine spectral structure of the isotropic high-energy gamma-radiation, (2) Attempting to identify the many still-unidentified Fermi-LAT gamma-ray sources. Gamma-400 will likely be the only space-based gamma-ray observatory operating at the end of the decade. In our proposed Gamma-400-LE version, it will substantially improve upon the capabilities of Fermi LAT and AGILE in both LE and HE energy range. Measuring gamma-rays from approx 20 MeV to approx 1 TeV for at least 7 years, Gamma-400-LE will address the topics of dark matter, cosmic ray origin and propagation, neutron stars, flaring pulsars, black holes, AGNs, GRBs, and actively participate in multiwavelength campaigns.

Genomic sequences of murine gamma B- and gamma C-crystallin-encoding genes: promoter analysis and complete evolutionary pattern of mouse, rat and human gamma-crystallins.

PubMed

Graw, J; Liebstein, A; Pietrowski, D; Schmitt-John, T; Werner, T

1993-12-22

The murine genes, gamma B-cry and gamma C-cry, encoding the gamma B- and gamma C-crystallins, were isolated from a genomic DNA library. The complete nucleotide (nt) sequences of both genes were determined from 661 and 711 bp, respectively, upstream from the first exon to the corresponding polyadenylation sites, comprising more than 2650 and 2890 bp, respectively. The new sequences were compared to the partial cDNA sequences available for the murine gamma B-cry and gamma C-cry, as well as to the corresponding genomic sequences from rat and man, at both the nt and predicted amino acid (aa) sequence levels. In the gamma B-cry promoter region, a canonical CCAAT-box, a TATA-box, putative NF-I and C/EBP sites were detected. An R-repeat is inserted 366 bp upstream from the transcription start point. In contrast, the gamma C-cry promoter does not contain a CCAAT-box, but some other putative binding sites for transcription factors (AP-2, UBP-1, LBP-1) were located by computer analysis. The promoter regions of all six gamma-cry from mouse, rat and human, except human psi gamma F-cry, were analyzed for common sequence elements. A complex sequence element of about 70-80 bp was found in the proximal promoter, which contains a gamma-cry-specific and almost invariant sequence (crygpel) of 14 nt, and ends with the also invariant TATA-box. Within the complex sequence element, a minimum of three further features specific for the gamma A-, gamma B- and gamma D/E/F-cry genes can be defined, at least two of which were recently shown to be functional. In addition to these four sequence elements, a subtype-specific structure of inverted repeats with different-sized spacers can be deduced from the multiple sequence alignment. A phylogenetic analysis based on the promoter region, as well as the complete exon 3 of all gamma-cry from mouse, rat and man, suggests separation of only five gamma-cry subtypes (gamma A-, gamma B-, gamma C-, gamma D- and gamma E/F-cry) prior to species separation.

Predicting diffusion paths and interface motion in gamma/gamma + beta, Ni-Cr-Al diffusion couples

NASA Technical Reports Server (NTRS)

Nesbitt, J. A.; Heckel, R. W.

1987-01-01

A simplified model has been developed to predict Beta recession and diffusion paths in ternary gamma/gamma + beta diffusion couples (gamma:fcc, beta: NiAl structure). The model was tested by predicting beta recession and diffusion paths for four gamma/gamma + beta, Ni-Cr-Al couples annealed for 100 hours at 1200 C. The model predicted beta recession within 20 percent of that measured for each of the couples. The model also predicted shifts in the concentration of the gamma phase at the gamma/gamma + beta interface within 2 at. pct Al and 6 at. pct Cr of that measured in each of the couples. A qualitative explanation based on simple kinetic and mass balance arguments has been given which demonstrates the necessity for diffusion in the two-phase region of certain gamma/gamma + beta, Ni-Cr-Al couples.

Comparison of gamma-gamma Phase Coarsening Responses of Three Powder Metal Disk Superalloys

NASA Technical Reports Server (NTRS)

Gabb, T. P.; Gayda, J.; Johnson, D. F.; MacKay, R. A.; Rogers, R. B.; Sudbrack, C. K.; Garg, A.; Locci, I. E.; Semiatin, S. L.; Kang, E.

2016-01-01

The phase microstructures of several powder metal (PM) disk superalloys were quantitatively evaluated. Contents, chemistries, and lattice parameters of gamma and gamma strengthening phase were determined for conventionally heat treated Alloy 10, LSHR, and ME3 superalloys, after electrolytic phase extractions. Several of long term heat treatments were then performed, to allow quantification of the precipitation, content, and size distribution of gamma at a long time interval to approximate equilibrium conditions. Additional coarsening heat treatments were performed at multiple temperatures and shorter time intervals, to allow quantification of the precipitation, contents and size distributions of gamma at conditions diverging from equilibrium. Modest differences in gamma and gamma lattice parameters and their mismatch were observed among the alloys, which varied with heat treatment. Yet, gamma coarsening rates were very similar for all three alloys in the heat treatment conditions examined. Alloy 10 had higher gamma dissolution and formation temperatures than LSHR and ME3, but a lower lattice mismatch, which was slightly positive for all three alloys at room temperature. The gamma precipitates of Alloy 10 appeared to remain coherent at higher temperatures than for LSHR and ME3. Higher coarsening rates were observed for gamma precipitates residing along grain boundaries than for those within grains in all three alloys, during slow-moderate quenching from supersolvus solution heat treatments, and during aging at temperatures of 843 C and higher.

Ursodeoxycholic Acid for Treatment of Enlarged Polycystic Liver.

PubMed

Iijima, Takashi; Hoshino, Junichi; Suwabe, Tatsuya; Sumida, Keiichi; Mise, Koki; Kawada, Masahiro; Imafuku, Aya; Hayami, Noriko; Hiramatsu, Rikako; Hasegawa, Eiko; Sawa, Naoki; Takaichi, Kenmei; Ubara, Yoshifumi

2016-02-01

Patients with autosomal dominant polycystic kidney disease and polycystic liver disease (PLD) often have elevated serum levels of alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (GGT). Ursodeoxycholic acid (UDCA) is used to treat biliary tract diseases, but its effect on PLD remains unclear. UDCA was administered for 1 year at a dose of 300 mg daily to seven PLD patients with elevated ALP or GGT levels who were selected for this treatment by experienced clinicians. Laboratory data and liver volumes were compared among three time points: 1 year before UDCA treatment, at the start of UDCA therapy, and 1 year after the start of therapy. Median GGT did not show a significant change between 1 year before UDCA (180 IU/L) and the start of UDCA therapy (209 IU/L), but it decreased significantly to 98 IU/L after 1 year of UDCA therapy (P = 0.015 vs. the start of therapy). ALP showed a significant increase from 1 year before UDCA (456 IU/L) to the start of UDCA therapy (561 IU/L), and then decreased significantly after 1 year of UDCA therapy (364 IU/L). Median liver volume did not show any significant changes among these three time points of assessment. UDCA may be effective for reducing biliary enzyme levels and inhibiting the growth of liver cysts in patients with PLD. © 2015 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

Determination of some enzymes and macro- and microelements in stallion seminal plasma and their correlations to semen quality.

PubMed

Pesch, Sandra; Bergmann, Martin; Bostedt, Hartwig

2006-07-15

Seminal plasma is very important for sperm metabolism as well as sperm function and survival and transport in the female genital tract. Analysis of enzyme activities and concentrations of elements can estimate integrity and function of sperm cell membranes. In man much data are available about biochemical analyses of seminal plasma. However, not many studies have been conducted in horses yet. We collected ejaculates from 72 stallions, measured the volume, obtained seminal plasma by centrifugation and examined spermatozoa with light microscopy for motility, concentration, for dead sperm and morphology. Of seminal plasma fluid, we measured activities of aspartate-amino-transferase (AST), gamma-glutamyl-transferase (GGT), alkaline phosphatase (AlP), acid phosphatase (AcP) and lactate-dehydrogenase (LDH) as well as concentrations of sodium (Na(+)), potassium (K(+)), total and ionised calcium (Ca(TOTAL)/Ca(2+)), magnesium (Mg(2+)), phosphate (P), chloride (Cl), copper (Cu), iron (Fe) and zinc (Zn). In addition, correlations among different parameters in light microscopy and seminal plasma were statistically examined by using the Spearman rank correlation coefficient. Median enzyme activities for AST, GGT, AlP, AcP and LDH were 80.0, 7,500, 30,200, 20.0, 81.0 IU/L, respectively. Concentrations of Na(+), K(+), Ca(TOTAL), Ca(2+), Mg(2+), P, Cl were 110.5, 22.1, 2.9, 1.7, 3.1, 1.1 and 114.5 mmol/L, and of microelements Cu, Fe and Zn were 17.8, 1.9 and 13.2 micromol/L, respectively. Furthermore, we found significant correlations between semen volume as well as sperm concentration and AST, GGT, AlP, AcP and LDH as well as Fe and Zn. This made us propose a primary testicular and epididymal origin of these parameters. Significant correlation between GGT and motility may be a sign for its function for cell protection against free radicals. LDH activity significantly correlates with motility and progressive motility, live:dead-ratio and pathomorphology. In our study, LDH seems to

The gamma-ray observatory

NASA Technical Reports Server (NTRS)

1991-01-01

An overview is given of the Gamma Ray Observatory (GRO) mission. Detection of gamma rays and gamma ray sources, operations using the Space Shuttle, and instruments aboard the GRO, including the Burst and Transient Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), and the Energetic Gamma Ray Experiment Telescope (EGRET) are among the topics surveyed.

High-frequency gamma oscillations coexist with low-frequency gamma oscillations in the rat visual cortex in vitro.

PubMed

Oke, Olaleke O; Magony, Andor; Anver, Himashi; Ward, Peter D; Jiruska, Premysl; Jefferys, John G R; Vreugdenhil, Martin

2010-04-01

Synchronization of neuronal activity in the visual cortex at low (30-70 Hz) and high gamma band frequencies (> 70 Hz) has been associated with distinct visual processes, but mechanisms underlying high-frequency gamma oscillations remain unknown. In rat visual cortex slices, kainate and carbachol induce high-frequency gamma oscillations (fast-gamma; peak frequency approximately 80 Hz at 37 degrees C) that can coexist with low-frequency gamma oscillations (slow-gamma; peak frequency approximately 50 Hz at 37 degrees C) in the same column. Current-source density analysis showed that fast-gamma was associated with rhythmic current sink-source sequences in layer III and slow-gamma with rhythmic current sink-source sequences in layer V. Fast-gamma and slow-gamma were not phase-locked. Slow-gamma power fluctuations were unrelated to fast-gamma power fluctuations, but were modulated by the phase of theta (3-8 Hz) oscillations generated in the deep layers. Fast-gamma was spatially less coherent than slow-gamma. Fast-gamma and slow-gamma were dependent on gamma-aminobutyric acid (GABA)(A) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and gap-junctions, their frequencies were reduced by thiopental and were weakly dependent on cycle amplitude. Fast-gamma and slow-gamma power were differentially modulated by thiopental and adenosine A(1) receptor blockade, and their frequencies were differentially modulated by N-methyl-D-aspartate (NMDA) receptors, GluK1 subunit-containing receptors and persistent sodium currents. Our data indicate that fast-gamma and slow-gamma both depend on and are paced by recurrent inhibition, but have distinct pharmacological modulation profiles. The independent co-existence of fast-gamma and slow-gamma allows parallel processing of distinct aspects of vision and visual perception. The visual cortex slice provides a novel in vitro model to study cortical high-frequency gamma oscillations.

A method to describe inelastic gamma field distribution in neutron gamma density logging.

PubMed

Zhang, Feng; Zhang, Quanying; Liu, Juntao; Wang, Xinguang; Wu, He; Jia, Wenbao; Ti, Yongzhou; Qiu, Fei; Zhang, Xiaoyang

2017-11-01

Pulsed neutron gamma density logging (NGD) is of great significance for radioprotection and density measurement in LWD, however, the current methods have difficulty in quantitative calculation and single factor analysis for the inelastic gamma field distribution. In order to clarify the NGD mechanism, a new method is developed to describe the inelastic gamma field distribution. Based on the fast-neutron scattering and gamma attenuation, the inelastic gamma field distribution is characterized by the inelastic scattering cross section, fast-neutron scattering free path, formation density and other parameters. And the contribution of formation parameters on the field distribution is quantitatively analyzed. The results shows the contribution of density attenuation is opposite to that of inelastic scattering cross section and fast-neutron scattering free path. And as the detector-spacing increases, the density attenuation gradually plays a dominant role in the gamma field distribution, which means large detector-spacing is more favorable for the density measurement. Besides, the relationship of density sensitivity and detector spacing was studied according to this gamma field distribution, therefore, the spacing of near and far gamma ray detector is determined. The research provides theoretical guidance for the tool parameter design and density determination of pulsed neutron gamma density logging technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of sub-acute methanol extract treatment of Calliandra portoricensis root bark on antioxidant defence capacity in an experimental rat model.

PubMed

Siemuri, Ese O; Akintunde, Jacob K; Salemcity, Anuoluwapo J

2015-07-01

The attendant side effects associated with some synthetic drugs used in the management of diseases have led to the search for safer alternative therapies that are relatively cheaper with minimal side effects. The methanol extract of Calliandra portoricensis root bark (CPRB) was orally administered at the doses of 5, 10, 20, and 25 mg/kg body weight for 14 consecutive days of 5 rats in each group. The control rats were given distilled water. The 95% methanol extract of CPRB significantly (p<0.05) scavenged NO• and OH• radicals compared to vitamin C. The level of lipid peroxidative products (malondialdehyde, MDA) was significantly (p<0.05) attenuated in a dose-dependent manner. Antioxidant enzymes including superoxide dismutase and catalase were significantly (p<0.05) exercabated in both liver and kidney in a dose-dependent manner. Furthermore, serum AST, alanine aminotransaminase and γ-glutamyltransferase (GGT) activity depicted non-significant (p>0.05) increase in the treated animals. The histological examination showed mild vacuolar, portal congestion and cell infiltration by mononuclear of the hepatic tissues. The study then concluded that a therapeutic dose of the methanol extract of CPRB triggered the antioxidant defence systems in male rats. It is, therefore, recommended that the doses should be carefully and clinically chosen because higher doses may cause some health risks.

Phosphatidylethanol Compared with Other Blood Tests as a Biomarker of Moderate Alcohol Consumption in Healthy Volunteers: A Prospective Randomized Study.

PubMed

Kechagias, Stergios; Dernroth, Dženeta Nezirević; Blomgren, Anders; Hansson, Therese; Isaksson, Anders; Walther, Lisa; Kronstrand, Robert; Kågedal, Bertil; Nystrom, Fredrik H

2015-07-01

It is generally agreed that traditional alcohol biomarkers lack in sensitivity to detect hazardous alcohol consumption. The present study was undertaken to evaluate the ability of phosphatidylethanol (PEth) and traditional alcohol markers to detect moderate alcohol consumption and to distinguish between moderate alcohol consumption and abstinence. Forty-four subjects, 32 females and 12 males, were included in the study. They were randomized to alcohol abstention or to alcohol consumption. Female participants consumed 150 ml of red wine (equivalent to 16 g of alcohol) per 24 h and the male participants double the amount. The study lasted for 3 months. Blood samples were drawn at the start and at the end of the study period. Blood samples were analysed for PEth, carbohydrate-deficient transferrin (CDT), mean corpuscular volume (MCV), γ-glutamyltransferase (GGT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). ROC curves for the various biochemical markers were plotted in order to assess their ability to discriminate between abstention and moderate daily consumption of alcohol. PEth and CDT were the only markers with AUROCs significantly higher than 0.5, and PEth was detected in all participants randomized to alcohol consumption. PEth was the only marker that could detect moderate intake and the present results also indicate that PEth probably can distinguish moderate alcohol consumption from abstinence. © The Author 2015. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Epidemiological, clinical, haematological and biochemical characteristics of canine hypothyroidism.

PubMed

Dixon, R M; Reid, S W; Mooney, C T

1999-10-23

Hypothyroidism was diagnosed in 50 dogs and excluded in 86 dogs suspected of hypothyroidism, on the basis of the results of bovine thyrotropin response tests. Breed, pedigree, sex or neutering status did not significantly influence the likelihood of the dogs being hypothyroid. The hypothyroid dogs were significantly older than the non-hypothyroid dogs referred to the University of Glasgow during the same period. However, when dogs under two years of age were excluded from the statistical analyses there was no significant difference in age between the two groups. The most common clinical characteristics associated with hypothyroidism were metabolic signs (84 per cent of cases), particularly lethargy (76 per cent), obesity or weight gain (44 per cent), and exercise intolerance (24 per cent); and dermatological abnormalities (80 per cent), including alopecia (56 per cent), poor coat quality (30 per cent) and hyperpigmentation (20 per cent). When compared with the laboratory reference limits the most common biochemical and haematological abnormalities were increased concentrations of triglycerides (88 per cent), cholesterol (78 per cent), glucose (49 per cent), and fructosamine (43 per cent), and increased activities of creatine kinase (35 per cent), and decreased concentrations of inorganic phosphate (63 per cent), and a low red blood cell count (40 per cent). When compared with reference limits derived from the euthyroid dogs the most common abnormalities were increased concentrations of gamma-glutamyltransferase (21 per cent), cholesterol (18 per cent), and aspartate aminotransferase (15 per cent) and a decreased red blood cell count (29 per cent), and decreased neutrophils (18 per cent) and decreased activity of creatine kinase (15 per cent). Assessment of cholesterol, creatine kinase, aspartate aminotransferase, gamma-glutamyltransferase, and red blood cell and neutrophil counts may be particularly useful in distinguishing hypothyroid dogs from euthyroid animals

Evaluation of liver regeneration diet supplemented with omega-3 fatty acids: experimental study in rats.

PubMed

Silva, Rosilda Mendes da; Malafaia, Osvaldo; Torres, Orlando Jorge Martins; Czeczko, Nicolau Gregori; Marinho Junior, Carlos Hespanha; Kozlowski, Ronaldo Kiviatcoski

2015-01-01

to evaluate liver regeneration in rats after partial hepatectomy of 60% with and without action diet supplemented with fatty acids through the study of the regenerated liver weight, laboratory parameters of liver function and histological study. thirty-six Wistar rats, males, adults were used, weighing between 195 and 330 g assigned to control and groups. The supplementation group received the diet by gavage and were killed after 24h, 72h and seven days. Evaluation of regeneration occurred through analysis of weight gain liver, serum aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltranspeptidase, and mitosis of the liver stained with H&E. the diet supplemented group showed no statistical difference (p>0.05) on the evolution of weights. Administration of fatty acids post-hepatectomy had significant reduction in gamma glutamyltransferase levels and may reflect liver regeneration. Referring to mitotic index, it did not differ between period of times among the groups. supplementation with fatty acids in rats undergoing 60% hepatic resection showed no significant interference related to liver regeneration.

The gamma cycle.

PubMed

Fries, Pascal; Nikolić, Danko; Singer, Wolf

2007-07-01

Activated neuronal groups typically engage in rhythmic synchronization in the gamma-frequency range (30-100 Hz). Experimental and modeling studies demonstrate that each gamma cycle is framed by synchronized spiking of inhibitory interneurons. Here, we review evidence suggesting that the resulting rhythmic network inhibition interacts with excitatory input to pyramidal cells such that the more excited cells fire earlier in the gamma cycle. Thus, the amplitude of excitatory drive is recoded into phase values of discharges relative to the gamma cycle. This recoding enables transmission and read out of amplitude information within a single gamma cycle without requiring rate integration. Furthermore, variation of phase relations can be exploited to facilitate or inhibit exchange of information between oscillating cell assemblies. The gamma cycle could thus serve as a fundamental computational mechanism for the implementation of a temporal coding scheme that enables fast processing and flexible routing of activity, supporting fast selection and binding of distributed responses. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

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

Vanderlaan, M.; Fong, S.; King, E.B.

To improve identification of preneoplastic bladder cancer cells, we have studied two enzyme histochemical changes in bladder tumors induced in male Fisher 344 rats by the carcinogen N-butyl-N-(4-hydroxybutyl)-nitrosamine. In early areas of focal nodular hyperplasia there was a dramatic increase in staining for NADH:menadione oxidoreductase (diaphorase) activity. In nonfocal areas as well, there were many individual cells with intense staining, while the controls were of uniform moderate staining. Large papillomas and carcinomas often showed heterogeneous staining, ..gamma..-Glutamyltranspeptidase (GGT) was absent from normal urothelium and from all tumors except the most advanced carcinomas and large papillomas. In old, carcinogen-exposed animals, GGTmore » activity was seen in the luminal surface of tumors and in the interlesion urothelium. In newborn rats and in rats with regenerative hyperplasia following wounding of the urothelium, the diaphorase staining was less than that in the untreated adult. Our findings suggest that increased diaphorase activity may serve to identify early islands of carcinogen-induced, enzymatically altered bladder cells, while GGT will not.« less

A Platinum-Enriched gamma+gamma' Two-Phase Bond Coat on Ni-Base Superalloys

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

Zhang, Ying; Pint, Bruce A; Haynes, James A

2005-01-01

Pt-enriched {gamma} + {gamma}{prime} two-phase coating was applied to directionally-solidified Ni-based superalloy Ren{acute e} 142 substrates with three different Hf levels (0.02, 0.76, and 1.37 wt.%). The coating was prepared by electroplating a thin layer of Pt on the superalloy followed by a diffusion treatment. The as-deposited coating exhibited a {gamma} + {gamma}{prime} two-phase microstructure with a major composition of Ni-16Al-18Pt-7Cr-9Co (in at.%) along with some incorporation of refractory elements from the substrates. Cyclic oxidation testing at 1100 C in air indicated improved oxidation resistance of the Ren{acute e} 142 alloys with the Pt-enriched {gamma} + {gamma}{prime} coatings. In addition,more » the oxidation resistance of both uncoated and coated alloys was proportional to the Hf content in the substrate. Compared with the single-phase {beta}-(Ni,Pt)Al coating, slightly higher mass gains and localized spallation were observed on the {gamma} + {gamma}{prime} two-phase coating, which might be due to the segregation of refractory elements and high sulfur levels in these superalloy substrates.« less

Gamma ray transients

NASA Technical Reports Server (NTRS)

Cline, Thomas L.

1987-01-01

The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

Expression of peroxisome proliferator-activated receptor gamma (PPAR-gamma) in canine nasal carcinomas.

PubMed

Paciello, O; Borzacchiello, G; Varricchio, E; Papparella, S

2007-10-01

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-gamma is expressed in multiple normal and neoplastic tissues, such as the breast, colon, lung, ovary and placenta. In addition to adipogenic and anti-inflammatory effects, PPAR-gamma activation has been shown to be anti-proliferative by its differentiation-promoting effect, suggesting that activation of PPAR-gamma may be useful in slowing or arresting the proliferation of de-differentiated tumour cells. In this study, we investigated the expression of PPAR-gamma in normal and neoplastic canine nasal epithelium. Twenty-five samples composed of five normal nasal epithelia and 20 canine nasal carcinomas, were immunohistochemically stained for PPAR-gamma. The specificity of the antibody was verified by Western Blot analysis. Confocal laser scanning microscopical investigation was also performed. In normal epithelium, the staining pattern was cytoplasmic and polarized at the cellular free edge. In carcinomas, the neoplastic cells showed mainly strong cytoplasmatic PPAR-gamma expression; moreover, perinuclear immunoreactivity was also detected and few neoplastic cells exhibited a nuclear positivity. Our results demonstrate different patterns of PPAR-gamma expression in normal canine nasal epithelium when compared with canine nasal carcinoma. The importance of this transcription factor in the pathophysiology of several different tumours has stimulated much research in this field and has opened new opportunities for the treatment of the tumours.

Pattern of γ-glutamyl transferase activity in cow milk throughout lactation and relationships with metabolic conditions and milk composition.

PubMed

Calamari, L; Gobbi, L; Russo, F; Cappelli, F Piccioli

2015-08-01

The main objective of this experiment was to study the γ-glutamyl transferase (GGT) activity in milk during lactation and its relationship with metabolic status of dairy cows, milk yield, milk composition, and cheesemaking properties. The study was performed in a tied stall barn and involved 20 lactations from 12 healthy multiparous Italian Friesian dairy cows. During lactation starting at d 10, milk samples were collected weekly and analyzed for composition, somatic cells count, titratable acidity, and milk coagulation properties. The GGT activity was measured in defatted samples. Blood samples were collected weekly to assess biochemical indicators related to energy, protein, and mineral metabolism, markers of inflammation and some enzyme activities. The lactations of each cow were retrospectively categorized into 2 groups according to their milk GGT activity value through lactation. A median value of GGT activity in the milk of all lactations was calculated (3,045 U/L), and 10 lactations with lower GGT activity were classified as low while 10 lactations with greater GGT activity were classified as high. The average value of milk GGT activity during lactation was 3,863 and 3,024 U/L for high and low, respectively. The GGT activity decreased in early lactation and reached minimum values in the second month (3,289 and 2,355 U/L for high and low, respectively). Thereafter GGT activity increased progressively, reaching values in late lactation of 4,511 and 3,540 U/L in high and low, respectively. On average, milk yield was 40.81 and 42.76 kg/d in high and low, respectively, and a negative partial correlation with milk GGT activity was observed. A greater milk protein concentration was observed in high (3.39%) compared with low (3.18%), and a positive partial correlation with milk GGT activity was observed. Greater titratable acidity in high than that in low (3.75 vs. 3.45 degrees Soxhlet-Henkel/50 mL, respectively) was also observed. Plasma glucose was greater in

Cloning, sequencing and expression of white rhinoceros (Ceratotherium simum) interferon-gamma (IFN-gamma) and the production of rhinoceros IFN-gamma specific antibodies.

PubMed

Morar, D; Tijhaar, E; Negrea, A; Hendriks, J; van Haarlem, D; Godfroid, J; Michel, A L; Rutten, V P M G

2007-01-15

Bovine tuberculosis (BTB) is endemic in African buffalo (Syncerus caffer) in the Kruger National Park (KNP). In addition to buffalo, Mycobacterium bovis has been found in at least 14 other mammalian species in South Africa, including kudu (Tragelaphus strepsiceros), Chacma baboon (Papio ursinus) and lion (Panthera leo). This has raised concern about the spillover into other potentially susceptible species like rhinoceros, thus jeopardising breeding and relocation projects aiming at the conservation of biodiversity. Hence, procedures to screen for and diagnose BTB in black rhinoceros (Diceros bicornis) and white rhinoceros (Ceratotherium simum) need to be in place. The Interferon-gamma (IFN-gamma) assay is used as a routine diagnostic tool to determine infection of cattle and recently African buffalo, with M. bovis and other mycobacteria. The aim of the present work was to develop reagents to set up a rhinoceros IFN-gamma (RhIFN-gamma) assay. The white rhinoceros IFN-gamma gene was cloned, sequenced and expressed as a mature protein. Amino acid (aa) sequence analysis revealed that RhIFN-gamma shares a homology of 90% with equine IFN-gamma. Monoclonal antibodies, as well as polyclonal chicken antibodies (Yolk Immunoglobulin-IgY) with specificity for recombinant RhIFN-gamma were produced. Using the monoclonals as capture antibodies and the polyclonal IgY for detection, it was shown that recombinant as well as native white rhinoceros IFN-gamma was recognised. This preliminary IFN-gamma enzyme-linked immunosorbent assay (ELISA), has the potential to be developed into a diagnostic assay for M. bovis infection in rhinoceros.

Measurements of the $$\\mathrm{ pp \\to W \\gamma\\gamma }$$ and $$\\mathrm{ pp \\to Z \\gamma\\gamma }$$ cross sections and limits on anomalous quartic gauge couplings at $$\\sqrt{s} =$$ 8 TeV

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

Sirunyan, A. M.; Tumasyan, A.; Adam, W.

Here, measurements are presented ofmore » $$ \\mathrm{ W \\gamma\\gamma } $$ and $$ \\mathrm{ Z \\gamma\\gamma } $$ production in proton-proton collisions. Fiducial cross sections are reported based on a data sample corresponding to an integrated luminosity of 19.4 fb$$^{-1}$$ collected with the CMS detector at a center-of-mass energy of 8 TeV. Signal is identified through the $$\\mathrm{ W } \\to \\ell\

Measurements of the $$\\mathrm{ pp \\to W \\gamma\\gamma }$$ and $$\\mathrm{ pp \\to Z \\gamma\\gamma }$$ cross sections and limits on anomalous quartic gauge couplings at $$\\sqrt{s} =$$ 8 TeV

DOE PAGES

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; ...

2017-10-11

Here, measurements are presented ofmore » $$ \\mathrm{ W \\gamma\\gamma } $$ and $$ \\mathrm{ Z \\gamma\\gamma } $$ production in proton-proton collisions. Fiducial cross sections are reported based on a data sample corresponding to an integrated luminosity of 19.4 fb$$^{-1}$$ collected with the CMS detector at a center-of-mass energy of 8 TeV. Signal is identified through the $$\\mathrm{ W } \\to \\ell\

Red-Emitting Fluorescent Probe for Detection of γ-Glutamyltranspeptidase and Its Application of Real-Time Imaging under Oxidative Stress in Cells and in Vivo.

PubMed

Liu, Feiyan; Wang, Zhen; Wang, Wenli; Luo, Jian-Guang; Kong, Lingyi

2018-06-19

γ-Glutamyltranspeptidase (GGT) plays critical roles in regulating various physiological/pathophysiological processes including the intracellular redox homeostasis. However, an effective fluorescent probe for dissecting the relationships between GGT and oxidative stress in vivo remains largely unexplored. Herein, we present a light-up fluorescent probe (DCDHF-Glu) with long wavelength emission (613 nm) for the highly sensitive and selective detection of GGT using dicyanomethylenedihydrofuran derivative as the fluorescent reporter and γ-glutamyl group as the enzyme-active trigger. DCDHF-Glu is competent to real-time image endogenous GGT in live cells and mice. In particular, DCDHF-Glu enables the direct real-time visualization of the upregulation of GGT under drug-induced oxidative stress in the HepG2 cells and the LO2 cells, as well as in vivo, vividly implying its excellent capacity in elucidation of GGT function in GGT-related biological events.

Basics of Gamma Ray Detection

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

Stinnett, Jacob; Venkataraman, Ram

The objective of this training is to explain the origin of x-rays and gamma rays, gamma ray interactions with matter, detectors and electronics used in gamma ray-spectrometry, and features of a gamma-ray spectrum for nuclear material that is safeguarded.

Dynamic gamma knife radiosurgery

NASA Astrophysics Data System (ADS)

Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

2009-03-01

Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

Galactic plane gamma-radiation

NASA Technical Reports Server (NTRS)

Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Fichtel, C. E.; Ogelman, H. B.; Tumer, T.; Ozel, M. E.

1979-01-01

Analysis of the SAS 2 data together with the COS B results shows that the distribution of galactic gamma-radiation has several similarities to that of other large-scale tracers of galactic structure. The radiation is primarily confined to a thin disc which exhibits offsets from b = 0 degrees similar to warping at radio frequencies. The principal distinction of the gamma-radiation is a stronger contrast in intensity between the region from 310 to 45 degrees in longitude and the regions away from the center that can be attributed to a variation in cosmic-ray density as a function of position in Galaxy. The diffuse galactic gamma-ray energy spectrum shows no significant variation in direction, and the spectrum seen along the plane is the same as that for the galactic component of the gamma-radiation at high altitudes. The uniformity of the galactic gamma-ray spectrum, the smooth decrease in intensity as a function of altitude, and the absence of any galactic gamma-ray sources at high altitudes indicate a diffuse origin for bulk of the galactic gamma-radiation rather than a collection of localized sources.

Gamma-ray burster recurrence timescales

NASA Technical Reports Server (NTRS)

Schaefer, B. E.; Cline, T. L.

1984-01-01

Three optical transients have been found which are associated with gamma-ray bursters (GRBs). The deduced recurrence timescale for these optical transients (tau sub opt) will depend on the minimum brightness for which a flash would be detected. A detailed analysis using all available data of tau sub opt as a function of E(gamma)/E(opt) is given. For flashes similar to those found in the Harvard archives, the best estimate of tau sub opt is 0.74 years, with a 99% confidence interval from 0.23 years to 4.7 years. It is currently unclear whether the optical transients from GRBs also give rise to gamma-ray events. One way to test this association is to measure the recurrence timescale of gamma-ray events tau sub gamma. A total of 210 gamma-ray error boxes were examined and it was found that the number of observed overlaps is not significantly different from the number expected from chance coincidence. This observation can be used to place limits on tau sub gamma for an assumed luminosity function. It was found that tau sub gamma is approx. 10 yr if bursts are monoenergetic. However, if GRBs have a power law luminosity function with a wide dynamic range, then the limit is tau sub gamma 0.5 yr. Hence, the gamma-ray data do not require tau sub gamma and tau sub opt to be different.

Gamma watermarking

DOEpatents

Ishikawa, Muriel Y.; Wood, Lowell L.; Lougheed, Ronald W.; Moody, Kenton J.; Wang, Tzu-Fang

2004-05-25

A covert, gamma-ray "signature" is used as a "watermark" for property identification. This new watermarking technology is based on a unique steganographic or "hidden writing" digital signature, implemented in tiny quantities of gamma-ray-emitting radioisotopic material combinations, generally covertly emplaced on or within an object. This digital signature may be readily recovered at distant future times, by placing a sensitive, high energy-resolution gamma-ray detecting instrument reasonably precisely over the location of the watermark, which location may be known only to the object's owner; however, the signature is concealed from all ordinary detection means because its exceedingly low level of activity is obscured by the natural radiation background (including the gamma radiation naturally emanating from the object itself, from cosmic radiation and material surroundings, from human bodies, etc.). The "watermark" is used in object-tagging for establishing object identity, history or ownership. It thus may serve as an aid to law enforcement officials in identifying stolen property and prosecuting theft thereof. Highly effective, potentially very low cost identification-on demand of items of most all types is thus made possible.

γ-Glutamyl transpeptidase has a role in the persistent colonization of the avian gut by Campylobacter jejuni

PubMed Central

Barnes, If H.A.; Bagnall, Mary C.; Browning, Darren D.; Thompson, Stuart A.; Manning, Georgina; Newell, Diane G.

2009-01-01

The contribution of γ-glutamyl transpeptidase (GGT) to Campylobacter jejuni virulence and colonization of the avian gut has been investigated. The presence of the ggt gene in C. jejuni strains directly correlated with the expression of GGT activity as measured by cleavage and transfer of the γ-glutamyl moiety. Inactivation of the monocistronic ggt gene in C. jejuni strain 81116 resulted in isogenic mutants with undetectable GGT activity; nevertheless, these mutants grew normally in vitro. However, the mutants had increased motility, a 5.4-fold higher invasion efficiency into INT407 cells in vitro and increased resistance to hydrogen peroxide stress. Moreover, the apoptosis-inducing activity of the ggt mutant was significantly lower than that of the parental strain. In vivo studies showed that, although GGT activity was not required for initial colonization of 1-day-old chicks, the enzyme was required for persistant colonization of the avian gut. PMID:17600669

The Gamma-ray Sky with Fermi

NASA Technical Reports Server (NTRS)

Thompson, David

2012-01-01

Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

Gamma Ray Astronomy

NASA Technical Reports Server (NTRS)

Wu, S. T.

2000-01-01

The project has progressed successfully during this period of performance. The highlights of the Gamma Ray Astronomy teams efforts are: (1) Support daily BATSE data operations, including receipt, archival and dissemination of data, quick-look science analysis, rapid gamma-ray burst and transient monitoring and response efforts, instrument state-of-health monitoring, and instrument commanding and configuration; (2) On-going scientific analysis, including production and maintenance of gamma-ray burst, pulsed source and occultation source catalogs, gamma-ray burst spectroscopy, studies of the properties of pulsars and black holes, and long-term monitoring of hard x-ray sources; (3) Maintenance and continuous improvement of BATSE instrument response and calibration data bases; (4) Investigation of the use of solid state detectors for eventual application and instrument to perform all sky monitoring of X-Ray and Gamma sources with high sensitivity; and (5) Support of BATSE outreach activities, including seminars, colloquia and World Wide Web pages. The highlights of this efforts can be summarized in the publications and presentation list.

Gamma ray detector shield

DOEpatents

Ohlinger, R.D.; Humphrey, H.W.

1985-08-26

A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

Investigations of the total flavonoids extracted from flowers of Abelmoschus manihot (L.) Medic against α-naphthylisothiocyanate-induced cholestatic liver injury in rats.

PubMed

Yan, Jia-Yin; Ai, Guo; Zhang, Xiao-Jian; Xu, Hai-Jiang; Huang, Zheng-Ming

2015-08-22

The decoction of the flowers of Abelmoschus manihot (L.) Medic was traditionally used for the treatment of jaundice and various types of chronic and acute hepatitis in Anhui and Jiangsu Provinces of China for hundreds of years. Phytochemical studies have indicated that total flavonoids extracted from flowers of A. manihot (L.) Medic (TFA) were the major constituents of the flowers. Our previous studies have investigated the hepatoprotective effects of the TFA against carbon tetrachloride (CCl4) induced hepatocyte damage in vitro and liver injury in vivo. This study aimed to investigate the protective effects and mechanisms of TFA on α-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury in rats. The hepatoprotective activities of TFA (125, 250 and 500mg/kg) were investigated on ANIT-induced cholestatic liver injury in rats. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were used as indices of hepatic cell damage and measured. Meanwhile, the serum levels of alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), total bilirubin (TBIL), direct bilirubin (DBIL), and total bile acid (TBA) were used as indices of biliary cell damage and cholestasis and evaluated. Hepatic malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione transferase (GST), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) were measured in the liver homogenates. The bile flow in 4h was estimated and the histopathology of the liver tissue was evaluated. Furthermore, the expression of transporters, bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), and Na(+)-taurocholate cotransporting polypeptide (NTCP) were studied by western blot and reverse transcription-quantitative real-time polymerase chain reaction (RT-PCR) to elucidate the protective mechanisms of TFA against ANIT-induced cholestasis. The oral administration of TFA to ANIT-treated rats could

Wetting characteristics and blood clotting on surfaces of copoly(gamma-Benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine).

PubMed

Yano, E; Komai, T; Kawasaki, T; Kaifu, K; Atsuta, T; Kubo, Y; Fujiwara, Y

1985-09-01

The film surface of poly(gamma-benzyl-L-glutamate) (PBLG) was modified with 2-aminoethanol to enhance its hydrophilicity. Controlling the reaction conditions of PBLG and 2-aminoethanol, various types of copoly(gamma-benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine) film surfaces were obtained. Surface free energy (gamma sv), the dispersive component of gamma sv (gamma dsv), the nondispersive component of gamma sv (gamma psv), and the interfacial free energy of polymer surface with water (gamma sw), which were obtained by using the contact angle measurement and calculation method proposed by Andrade et al., were changed remarkably by the aminolysis. The gamma sv value increased after 2 h of aminolysis from 48.2 (PBLG) to 65.3 dyn/cm and gradually increased to around 70 dyn/cm after 12 h reaction. (gamma dsv) and (gamma psv) changed from 31.0 and 17.2 dyn/cm (PBLG) to 26.5 and 44.3 dyn/cm, respectively. These parameters of the material surfaces, modified over 12 h reaction, were found to be similar to those of the surfaces of canine aorta, vein, and human fibrin membrane. Blood clotting times on these polymer surfaces were comparatively longer than on siliconized glass surfaces.

Identification and characterization of novel peroxisome proliferator-activated receptor-gamma (PPAR-gamma) transcriptional variants in pig and human.

PubMed

Omi, T; Brenig, B; Spilar Kramer, S; Iwamoto, S; Stranzinger, G; Neuenschwander, S

2005-04-01

The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the steroid/thyroid/retinoid receptor superfamily, and is primarily expressed in fat tissue. To date, two major PPAR-gamma isoforms have been identified in pig, PPAR-gamma1 and PPAR-gamma2. Porcine PPAR-gamma1a consists of two leader exons, designated A1 and A2, followed by six exons containing the open reading frame. Here, we report the isolation and characterization of three novel PPAR-gamma1 transcripts. PPAR-gamma1b is derived from exon A1, with exon A2 spliced out. PPAR-gamma1c and PPAR-gamma1d are derived from the new exon, A', containing exon A2 (gamma1c) or without exon A2 (gamma1d). Based on PCR analysis of PAC clones that included sequences from the 5'-untranslated region of the PPAR-gamma gene, the new A' exon is located between the known exons A1 and A2. We also isolated the human homologue to exon A', as well as the two new PPAR-gamma1c and -gamma1d splice variants, from human adipose tissue. Studies of the expression of porcine PPAR-gamma by real time reverse transcription-polymerase chain reaction analysis show that transcripts derived from exon A1 were not expressed at significantly different levels in visceral fat (lamina subserosa) or subcutaneous fat (back fat, inner and outer layer). In contrast, exon A'-derived transcripts were expressed at progressively higher levels in the inner and outer layers of subcutaneous fat than in visceral fat. The same expression pattern was also observed for PPAR-gamma2. We hypothesize that there are three promoters, which differentially regulate PPAR-gamma1 and PPAR-gamma2 gene expression, depending on the specific localization of the fat tissue.

Terrestrial Gamma-Ray Flashes (TGFs)

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2010-01-01

This slide presentation reviews the observation of Terrestrial Gamma Ray Flashes (TGFs) by Gamma-Ray Telescopes. These were: (1) BATSE /Compton Observatory, (2) Solar Spectroscopic Imager, (3) AGILE Gamma-ray Telescope, and (4) Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope. It contains charts which display the counts over time, a map or the TGFs observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). and a map showing the latitude and longitude of 85 of the TGFs observed by the Fermi GBM.

Gamma ray camera

DOEpatents

Perez-Mendez, Victor

1997-01-01

A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

Relation of serum γ-glutamyl transferase activity with copper in an adult population.

PubMed

Peng, You-Fan; Wang, Chun-Fang; Pan, Guo-Gang

2017-10-26

The aim of this study was to evaluate the relationship between serum γ-glutamyl transferase (γ-GGT) activity and serum copper in an adult population. We analyzed 281 adult subjects who regularly attended the physical examination center at the Affiliated Hospital of Youjiang Medical University for Nationalities. The demographic and laboratory data of the participants were divided into two groups according to the median of serum γ-GGT activity. Serum copper concentrations in individuals with higher γ-GGT levels were significantly increased compared with those with lower γ-GGT concentrations (9.9±2.41 vs. 11.2±3.36 μmol/L, p<0.001). There was a positive correlation between serum γ-GGT activity and copper in all eligible subjects (r=0.198, p=0.001). Further, serum γ-GGT maintained a positive correlation with serum copper in both males and females (r=0.322, p<0.001; r=0.230, p=0.010). The results of multiple linear regression analysis showed that serum γ-GGT maintained a significantly positive correlation with copper after adjusting for multiple potential confounders (b=0.464, p=0.001). This study suggests that serum γ-GGT activity is correlated with copper in the study population, indicating that serum γ-GGT may be a biomarker to evaluate serum copper levels in an adult population.

Formation of gamma'-Ni3Al via the Peritectoid Reaction: gamma plus beta (+Al2O3) equals gamma'(+Al2O3)

NASA Technical Reports Server (NTRS)

Copland, Evan

2008-01-01

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma'-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3) = gamma + beta (+ Al2O3), at 1640 plus or minus 1 K and a liquid composition of 24.8 plus or minus 0.2 at.%Al (at an unknown oxygen content). The {gamma + beta + Al2O3} phase field is stable over the temperature range 1633 - 1640 K, and gamma'-Ni3Al forms via the peritectiod, gamma + beta (+ Al2O3) = gamma'(+ Al2O3), at 1633 plus or minus 1 K. This behavior is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma'-Ni3Al phase field.

Elevated liver enzymes in women with a family history of diabetes.

PubMed

Inoue, Kazuo; Matsumoto, Masatoshi; Miyoshi, Yuji; Kobayashi, Yasuki

2008-03-01

Both elevated liver enzymes and a family history of diabetes mellitus (FHDM) are independent risk factors for type 2 diabetes. This study evaluates the epidemiological association between elevated liver enzymes and FHDM. Subjects included 3512 women workers without diabetes, hepatitis, a smoking habit, or a history of alcohol intake. Blood samples and personal data were collected from all subjects. Subjects with FHDM had a higher mean body mass index (BMI: 23.9kg/m(2) vs. 23.4kg/m(2); p=0.003). Laboratory testing also revealed higher mean fasting plasma glucose (FPG: 5.67mmol/L vs. 5.22mmol/L; p<0.001), asparate aminotransferase (AST: 20.0IU/L vs. 19.2IU/L; p=0.049), alanine aminotransferase (ALT: 18.4IU/L vs. 16.7IU/L; p=0.004), gamma-glutamyltranspeptidase (GGT: 24.1IU/L vs. 20.5IU/L; p<0.001), and triglycerides (TG: 1.09mmol/L vs. 1.00mmol/L; p=0.011) for FHDM subjects, when adjusted for age and BMI. Multiple linear regression analysis revealed that FHDM, age, BMI, FPG, and TG were correlated with GGT (p=0.004 for FHDM; p<0.001 for age, BMI, FPG, and TG). Elevated liver enzymes were associated with FHDM. In particular, elevated GGT was related to FHDM, independent of the other variables. Elevated liver enzymes, probably due to fat deposition in the liver, may play a role in increasing the risk of diabetes in individuals with FHDM.

Liraglutide attenuates partial warm ischemia-reperfusion injury in rat livers.

PubMed

Abdelsameea, Ahmed A; Abbas, Noha A T; Abdel Raouf, Samar M

2017-03-01

Ischemia-reperfusion (IR) injury constitutes the most important cause of primary dysfunction of liver grafts. In this study, we have addressed the possible hepatoprotective action of liraglutide against partial warm hepatic IR injury in male rats. Rats were randomly assigned into: sham, IR, and liraglutide-pretreated IR groups. Liraglutide was administered 50 μg/kg s.c. twice daily for 14 days, and then, hepatic IR was induced by clamping portal vein and hepatic artery to left and median lobes for 30 min followed by reperfusion for 24 h. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transferase (GGT) activities were determined. Malondialdehyde (MDA) level, reduced glutathione (GSH) content, tumor necrosis factor-α (TNF-α), phosphoralated Akt (p-Akt), and caspase-3 levels of the liver were determined. Hematoxylin and eosin (H&E) stained sections from liver were examined as well as immunohistochemical sections for detection of Bcl-2 expression. IR injury increased ALT, AST, and GGT while decreased GSH and p-Akt with increase in MDA, TNF-α, and caspase-3 levels in the liver with necrosis and inflammatory cellular infiltration with decreased Bcl-2 expression. Pretreatment with liraglutide decreased ALT, AST, and GGT activities while increased glutathione content and Akt activation with decrements in MDA, TNF-α, and caspase-3 levels with attenuation of necrosis and inflammation while enhanced Bcl-2 expression in the liver. Liraglutide protects against IR injury of the liver through antiinflammatory and antioxidant actions as well as inhibition of apoptosis.

Gamma-ray astrophysics

NASA Technical Reports Server (NTRS)

Stecker, F. W. (Editor); Trombka, J. I. (Editor)

1973-01-01

Conference papers on gamma ray astrophysics are summarized. Data cover the energy region from about 0.3 MeV to a few hundred GeV and theoretical models of production mechanisms that give rise to both galactic and extragalactic gamma rays.

The Gamma-ray Universe through Fermi

NASA Technical Reports Server (NTRS)

Thompson, David J.

2012-01-01

Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

Topics in gamma ray astronomy

NASA Technical Reports Server (NTRS)

Ramaty, R.; Lingenfelter, R. E.

1986-01-01

Observations of gamma rays from solar flares, gamma ray bursts, the Galactic center, galactic nucleosynthesis, SS433, and Cygnus X-3, and their effects on astrophysical problems are discussed. It is observed that gamma ray spectra from solar flares are applicable to the study of particle acceleration and confinement and the determination of chemical abundances in the solar atmosphere. The gamma ray lines from the compact galactic object SS433 are utilized to examine the acceleration of jets, and analysis of the gamma ray lines of Cygnus X-3 reveal that particles can be accelerated in compact sources to ultrahigh energies.

A study of interdiffusion in beta + gamma/gamma + gamma prime Ni-Cr-Al. M.S. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Carol, L. A.

1985-01-01

Ternary diffusion in the NiCrAl system at 1200 C was studied with beta + gamma/gamma + gamma prime infinite diffusion couples. Interdiffusion resulted in the formation of complex, multiphase diffusion zones. Concentration/distance profiles for Cr and Al in the phases present in the diffusion zone were measured after 200 hr. The Ni-rich portion of the NiCrAl phase diagram (1200 C) was also determined. From these data, bulk Cr and Al profiles were calculated and translated to diffusion paths on the ternary isotherm. Growth layer kinetics of the layers present in the diffusion zone were also measured.

Neutron monitoring systems including gamma thermometers and methods of calibrating nuclear instruments using gamma thermometers

DOEpatents

Moen, Stephan Craig; Meyers, Craig Glenn; Petzen, John Alexander; Foard, Adam Muhling

2012-08-07

A method of calibrating a nuclear instrument using a gamma thermometer may include: measuring, in the instrument, local neutron flux; generating, from the instrument, a first signal proportional to the neutron flux; measuring, in the gamma thermometer, local gamma flux; generating, from the gamma thermometer, a second signal proportional to the gamma flux; compensating the second signal; and calibrating a gain of the instrument based on the compensated second signal. Compensating the second signal may include: calculating selected yield fractions for specific groups of delayed gamma sources; calculating time constants for the specific groups; calculating a third signal that corresponds to delayed local gamma flux based on the selected yield fractions and time constants; and calculating the compensated second signal by subtracting the third signal from the second signal. The specific groups may have decay time constants greater than 5.times.10.sup.-1 seconds and less than 5.times.10.sup.5 seconds.

Liver biochemistry and associations with alcohol intake, hepatitis B virus infection and Inuit ethnicity: a population-based comparative epidemiological survey in Greenland and Denmark.

PubMed

Rex, Karsten Fleischer; Krarup, Henrik Bygum; Laurberg, Peter; Andersen, Stig

2016-01-01

Hepatitis B virus (HBV) infection is common in Arctic populations and high alcohol intake has been associated with an increased risk of a number of diseases. Yet, a description of the influence of alcohol intake in persons with HBV infection on liver biochemistry is lacking. We aimed to describe the association between reported alcohol intake and liver biochemistry taking into account also HBV infection, ethnicity, Inuit diet, body mass index (BMI), gender and age in an Arctic population. Population-based investigation of Inuit (n=441) and non-Inuit (94) in Greenland and Inuit living in Denmark (n=136). Participants filled in a questionnaire on alcohol intake and other life style factors. Blood samples were tested for aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin, albumin, hepatitis B surface antigen, hepatitis B surface antibody and hepatitis B core antibody. We also performed physical examinations. Participation rate was 95% in Greenland and 52% in Denmark. An alcohol intake above the recommended level was reported by 12.9% of non-Inuit in Greenland, 9.1% of Inuit in East Greenland, 6.1% of Inuit migrants and 3.4% of Inuit in the capital of Greenland (p=0.035). Alcohol intake was associated with AST (p<0.001) and GGT (p=0.001), and HBV infection was associated with ALP (p=0.001) but not with AST, GGT, bilirubin or albumin in the adjusted analysis. Inuit had higher AST (p<0.001), GGT (p<0.001) and ALP (p=0.001) values than non-Inuit after adjustment for alcohol, diet, BMI and HBV exposure. Ethnic origin modified the association between alcohol and AST, while HBV infection did not modify the associations between alcohol and liver biochemistry. Non-Inuit in Greenland reported a higher alcohol intake than Inuit. Ethnic origin was more markedly associated with liver biochemistry than was alcohol intake, and Greenlandic ethnicity modified the effect of alcohol intake on AST. HBV infection was slightly

Liver biochemistry and associations with alcohol intake, hepatitis B virus infection and Inuit ethnicity: a population-based comparative epidemiological survey in Greenland and Denmark

PubMed Central

Rex, Karsten Fleischer; Krarup, Henrik Bygum; Laurberg, Peter; Andersen, Stig

2016-01-01

Background Hepatitis B virus (HBV) infection is common in Arctic populations and high alcohol intake has been associated with an increased risk of a number of diseases. Yet, a description of the influence of alcohol intake in persons with HBV infection on liver biochemistry is lacking. Objective We aimed to describe the association between reported alcohol intake and liver biochemistry taking into account also HBV infection, ethnicity, Inuit diet, body mass index (BMI), gender and age in an Arctic population. Design and methods Population-based investigation of Inuit (n=441) and non-Inuit (94) in Greenland and Inuit living in Denmark (n=136). Participants filled in a questionnaire on alcohol intake and other life style factors. Blood samples were tested for aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin, albumin, hepatitis B surface antigen, hepatitis B surface antibody and hepatitis B core antibody. We also performed physical examinations. Results Participation rate was 95% in Greenland and 52% in Denmark. An alcohol intake above the recommended level was reported by 12.9% of non-Inuit in Greenland, 9.1% of Inuit in East Greenland, 6.1% of Inuit migrants and 3.4% of Inuit in the capital of Greenland (p=0.035). Alcohol intake was associated with AST (p<0.001) and GGT (p=0.001), and HBV infection was associated with ALP (p=0.001) but not with AST, GGT, bilirubin or albumin in the adjusted analysis. Inuit had higher AST (p<0.001), GGT (p<0.001) and ALP (p=0.001) values than non-Inuit after adjustment for alcohol, diet, BMI and HBV exposure. Ethnic origin modified the association between alcohol and AST, while HBV infection did not modify the associations between alcohol and liver biochemistry. Conclusions Non-Inuit in Greenland reported a higher alcohol intake than Inuit. Ethnic origin was more markedly associated with liver biochemistry than was alcohol intake, and Greenlandic ethnicity modified the effect

Gamma-ray astronomy

NASA Technical Reports Server (NTRS)

Ramaty, R.; Lingenfelter, R. E.

1982-01-01

Cosmic gamma rays, the physical processes responsible for their production and the astrophysical sites from which they were seen are reported. The bulk of the observed gamma ray emission is in the photon energy range from about 0.1 MeV to 1 GeV, where observations are carried out above the atmosphere. There are also, however, gamma ray observations at higher energies obtained by detecting the Cerenkov light produced by the high energy photons in the atmosphere. Gamma ray emission was observed from sources as close as the Sun and the Moon and as distant as the quasar 3C273, as well as from various other galactic and extragalactic sites. The radiation processes also range from the well understood, e.g. energetic particle interactions with matter, to the still incompletely researched, such as radiation transfer in optically thick electron positron plasmas in intense neutron star magnetic fields.

Simulated and measured neutron/gamma light output distribution for poly-energetic neutron/gamma sources

NASA Astrophysics Data System (ADS)

Hosseini, S. A.; Zangian, M.; Aghabozorgi, S.

2018-03-01

In the present paper, the light output distribution due to poly-energetic neutron/gamma (neutron or gamma) source was calculated using the developed MCNPX-ESUT-PE (MCNPX-Energy engineering of Sharif University of Technology-Poly Energetic version) computational code. The simulation of light output distribution includes the modeling of the particle transport, the calculation of scintillation photons induced by charged particles, simulation of the scintillation photon transport and considering the light resolution obtained from the experiment. The developed computational code is able to simulate the light output distribution due to any neutron/gamma source. In the experimental step of the present study, the neutron-gamma discrimination based on the light output distribution was performed using the zero crossing method. As a case study, 241Am-9Be source was considered and the simulated and measured neutron/gamma light output distributions were compared. There is an acceptable agreement between the discriminated neutron/gamma light output distributions obtained from the simulation and experiment.

Measuring the charged pion polarizability in the gamma gamma -> pi+pi- reaction

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

Lawrence, David W.; Miskimen, Rory A.; Mushkarenkov, Alexander Nikolaevich

2013-08-01

Development has begun of a new experiment to measure the charged pion polarizabilitymore » $$\\alpha_{\\pi}-\\beta_{\\pi}$$. The charged pion polarizability ranks among the most important tests of low-energy QCD presently unresolved by experiment. Analogous to precision measurements of $$\\pi^{\\circ}\\rightarrow\\gamma\\gamma$$ that test the intrinsic odd-parity (anomalous) sector of QCD, the pion polarizability tests the intrinsic even-parity sector of QCD. The measurement will be performed using the $$\\gamma\\gamma\\rightarrow\\pi^{+{}}\\pi^{-{}}$$ cross section accessed via the Primakoff mechanism on nuclear targets using the GlueX detector in Hall D at Jefferson Lab. The linearly polarized photon source in Hall-D will be utilized to separate the Primakoff cross-section from coherent $$\\rho^{\\circ}$$ production.« less

Future prospects for gamma-ray

NASA Technical Reports Server (NTRS)

Fichtel, C.

1980-01-01

Astrophysical phenomena discussed are: the very energetic and nuclear processes associated with compact objects; astrophysical nucleo-synthesis; solar particle acceleration; the chemical composition of the planets and other bodies of the solar system; the structure of our galaxy; the origin and dynamic pressure effects of the cosmic rays; the high energy particles and energetic processes in other galaxies, especially active ones; and the degree of matter antimater symmetry of the universe. The gamma ray results of GAMMA-I, the gamma ray observatory, the gamma ray burst network, solar polar, and very high energy gamma ray telescopes on the ground provide justification for more sophisticated telescopes.

Gamma ray camera

DOEpatents

Perez-Mendez, V.

1997-01-21

A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

Histaminergic regulation of interferon-gamma (IFN-gamma) production by human natural killer (NK) cells.

PubMed

Asea, A; Hansson, M; Czerkinsky, C; Houze, T; Hermodsson, S; Strannegård, O; Hellstrand, K

1996-08-01

Monocytes, recovered from human peripheral blood by counter-current centrifugal elutriation, effectively inhibit the production of IFN-gamma by CD3-/56+ NK cells in response to IL-2. This study aimed at defining the nature of the inhibitory signal, particularly the importance of monocyte-derived reactive metabolites of oxygen. It was found that monocytes recovered from patients with chronic granulomatous disease (CGD), a condition characterized by deficient NADPH-oxidase activity of phagocytes, did not inhibit IFN-gamma production by NK cells. Further, catalase, a scavenger of hydrogen peroxide, completely reversed the inhibitory signal whereas scavengers of the superoxide anion, hypohalous acids, the hydroxyl radical, or nitric oxide synthesis inhibitors such as L-NMMA were ineffective. Inhibition of IFN-gamma production was operating on a pretranslational level, as indicated by the inability of enriched NK cells to accumulate IFN-gamma mRNA in the presence of elutriated monocytes. Hydrogen peroxide, at micromolar concentrations, reconstituted the inhibition of IFN-gamma production when added to enriched NK cells. Histamine, a biogenic amine which inhibits the generation of reactive oxygen metabolites in monocytes, abrogated the inhibition of IFN-gamma production in NK cells; by this mechanism, histamine strongly synergized with IL-2 to induce IFN-gamma in mixtures of NK cells and monocytes. The synergizing effect of histamine was specifically mediated by H2-type histamine receptors. We conclude that: (i) the induction of IFN-gamma mRNA in NK cells is effectively down-regulated by products of the oxidative metabolism of monocytes; and (ii) histamine effectively enhances IFN-gamma production by preventing monocyte-induced oxidative damage to NK cells.

Gamma ray astrophysics to the year 2000. Report of the NASA Gamma Ray Program Working Group

NASA Technical Reports Server (NTRS)

1988-01-01

Important developments in gamma-ray astrophysics up to energies of 100 GeV during the last decade are reviewed. Also, the report seeks to define the major current scientific goals of the field and proposes a vigorous program to pursue them, extending to the year 2000. The goals of gamma-ray astronomy include the study of gamma rays which provide the most direct means of studying many important problems in high energy astrophysics including explosive nucleosynthesis, accelerated particle interactions and sources, and high-energy processes around compact objects. The current research program in gamma-ray astronomy in the U.S. including the space program, balloon program and foreign programs in gamma-ray astronomy is described. The high priority recommendations for future study include an Explorer-class high resolution gamma-ray spectroscopy mission and a Get Away Special cannister (GAS-can) or Scout class multiwavelength experiment for the study of gamma-ray bursts. Continuing programs include an extended Gamma Ray Observatory mission, continuation of the vigorous program of balloon observations of the nearby Supernova 1987A, augmentation of the balloon program to provide for new instruments and rapid scientific results, and continuation of support for theoretical research. Long term recommendations include new space missions using advanced detectors to better study gamma-ray sources, the development of these detectors, continued study for the assembly of large detectors in space, collaboration with the gamma-ray astronomy missions initiated by other countries, and consideration of the Space Station attached payloads for gamma-ray experiments.

The effect of alloying on gamma and gamma prime in nickel-base superalloys

NASA Technical Reports Server (NTRS)

Dreshfield, R. L.; Wallace, J. F.

1972-01-01

An investigation was conducted to determine the compositional limits of gamma and gamma prime phases in nickel-base superalloys. Fifty-one nickel-base alloys were melted under vacuum and heat treated for 4 hours at 1190 C followed by 1008 hours at 850 C. The alloys had the following composition ranges: A1 4.0 to 13 atomic percent, Cr 6.5 to 20.5 percent, Ti 0.25 to 4.75 percent, Mo 0.0 to 6.0 percent, and W 0.0 to 4.0 percent. The residues from the ammonium sulfate electrolytic extraction for the two-phase alloys were analyzed chemically and by X-ray diffraction. The results of the investigation were used to assemble a mathematical model of the gamma-gamma prime region of the Ni-Al-Cr-Ti-Mo-W system. A computer program was written to analyze the model of the phase diagram. Some of these results are also presented graphically. The resulting model is capable of satisfactorily predicting the compositions of conjugate gamma-gamma prime phases in the alloys investigated and twelve of fifteen commercial superalloys studied.

Status of the GAMMA-400 Project

NASA Technical Reports Server (NTRS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Gusakov, Yu. V.; Farber, M. O.;

Hyperproduction of γ-glutamyl transpeptidase from Bacillus licheniformis ER15 in the presence of high salt concentration.

PubMed

Bindal, Shruti; Gupta, Rani

2017-02-07

Microbial γ-glutamyl transpeptidases (GGTs) have been exploited in biotechnological, pharmaceutical, and food sectors for the synthesis of various γ-glutamyl compounds. But, till date, no bacterial GGTs are commercially available in the market because of lower levels of production from various sources. In the current study, production of GGT from Bacillus licheniformis ER15 was investigated to achieve high GGT titers. Hyperproduction of GGT from B. licheniformis ER15 was achieved with 6.4-fold enhancement (7921.2 ± 198.7 U/L) by optimization of culture medium following one-variable-at-a-time strategy and statistical approaches. Medium consisting of Na 2 HPO 4 : 0.32% (w/v); KH 2 PO 4 : 0.15% (w/v); starch: 0.1% (w/v); soybean meal: 0.5% (w/v); NaCl: 4.0% (w/v), and MgCl 2 : 5 mM was found to be optimal for maximum GGT titers. Maximum GGT titers were obtained, in the optimized medium at 37°C and 200 rpm, after 40 h. It was noteworthy that GGT production was a linear function of sodium chloride concentration, as observed during response surface methodology. While investigating the role of NaCl on GGT production, it was found that NaCl drastically decreased subtilisin concentration and indirectly increasing GGT recovery. B. licheniformis ER15 is proved to be a potential candidate for large-scale production of GGT enzyme and its commercialization.

Formation of fine {gamma} grain structure through fine {alpha}{sub 2}/{gamma} lamellar structure in Ti-rich TiAl alloy

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

Kumagai, T.; Abe, E.; Nakamura, M.

1997-12-31

Microstructural development of an extremely fine {alpha}{sub 2}-Ti{sub 32}Al/{gamma}-TiAl lamellar structure, which was formed by ice water quenching after solution-treatment in a high-temperature {alpha}-Ti phase field for a long period of time, was examined during isothermal treatment. In an as-quenched Ti-48at.%Al alloy, the massively transformed {gamma} ({gamma}{sub m}) and untransformed (meaning massively untransformed) fine {alpha}{sub 2}/{gamma} lamellar regions were observed. Fine {gamma} grains, which were similar to {gamma}{sub m}, were generated both within the fine {alpha}{sub 2}/{gamma} lamellae and at the boundary area between the {gamma}{sub m} and the fine {alpha}{sub 2}/{gamma} lamellar regions by aging at low-temperature (1,173 K)more » for a short time (180s). Further aging (1.8ks) caused the coarsening of these newly generated fine {gamma} grains. On the other hand, the coarsening of the {gamma} grains occurred by a high-temperature (1,323 K) aging treatment even for 180s. Fine {alpha}{sub 2} plates and particles, which were aligned to a particular direction, were observed in the {gamma} grain interiors, indicating that the newly generated {gamma} grains grew at the expense of the fine {alpha}{sub 2}/{gamma} lamellae. It can be considered that the {gamma} grain formation through the fine {alpha}{sub 2}/{gamma} lamellae is closely related to the {alpha}{sub 2}{yields}{gamma} reaction of the {alpha}{sub 2} plates sandwiched by the {gamma} plates, and needs the fast heating rate enough to overcome the {alpha}{sub 2}/{gamma}{yields}{gamma}/{gamma} lamellae reaction.« less

Cloning and expression of γ-glutamyl transpeptidase and its relationship to greening in crushed garlic (Allium sativum) cloves.

PubMed

Cho, Jungeun; Park, Minkyu; Choi, Doil; Lee, Seung Koo

2012-01-30

Garlic greening occurs when garlic cloves are stored at low temperature, increasing 1-propenyl cysteine sulfoxide, which is induced by γ-glutamyl transpeptidase (GGT) activity. Although the metabolism of the γ-glutamyl peptide is important for the biosynthesis of green pigments in crushed garlic cloves, garlic GGT is poorly characterised. For the analysis of GGT at the gene level, the garlic GGT sequence was partially cloned using an onion GGT sequence. The relationship between garlic greening and related gene expressions, depending on storage condition, was investigated using reverse transcription polymerase chain reaction for garlic GGT and alliinase. Three storage conditions were set: A, storage at a constant temperature of 20 °C; B, storage at 20 °C for 3 months and then transfer to 0 °C for an additional 3 months; C, storage at 0 °C for 3 months and then transfer to 20 °C for an additional 3 months. GGT expression increased under storage condition B and decreased under storage condition C. However, alliinase expression was not affected by storage condition. Greening in crushed garlic cloves increases with increasing GGT expression at low temperature, while alliinase expression is not affected. Copyright © 2011 Society of Chemical Industry.

Fusion gamma diagnostics

NASA Astrophysics Data System (ADS)

Medley, S. S.; Cecil, F. E.; Cole, D.; Conway, M. A.; Wilkinson, F. J., III

1985-05-01

Nuclear reactions of interest in fusion research often possess a branch yielding prompt emission of gamma radiation in excess of 15 MeV which can be exploited to provide a new fusion reaction diagnostic having applications similar to conventional neutron emission measurements. Conceptual aspects of fusion gamma diagnostics are discussed with emphasis on application to the Tokamak Fusion Test Reactor (TFTR) during deuterium neutral beam heating of D-T and D-3He plasmas. Recent measurements of the D (T, γ)5He, D(3He, γ)5Li, and D(D, γ)4He branching ratios at low center-of-mass energy (30-100 keV) and of the response of a large volume Ne226 detector for gamma detection in high neutron backgrounds are presented. Using a well-shielded Ne226 detector during 20 MW-120 kV deuterium beam heating of a tritium plasma in TFTR, the D(T, γ)5He gamma signal level is estimated to be 3.5×105 cps.

Age-Related DNA Methylation Changes and Neoplastic Transformation of the Human Prostate

DTIC Science & Technology

2011-07-01

Vol. 4 Issue 1 Figure 4. Methylation and expression analysis of the Sprouty1. (A) Representative program traces for Sprouty1. Gray colums represents...5’-ggt acc CCC TCC TGA GCT CAT GGT AAC CT-3’ Fwd 6 (-509) 5’-ggt acc CTT CTG GTT TGG AGC ACA GTG CAA AG-3’ Fwd 5 (-1318) 5’ggt acc AGA AGA CCT...CCC GAG GTG GAT GTT A-3’ Fwd3 (-2025) 5’-ggt acc CTG TCA ATC ACC GGG AGC-3’ Reverse (+8) 5’-gct agc AAT CCG CAC TGA ATA AAT AGT TGA C-3’. For

A gamma beam profile imager for ELI-NP Gamma Beam System

NASA Astrophysics Data System (ADS)

Cardarelli, P.; Paternò, G.; Di Domenico, G.; Consoli, E.; Marziani, M.; Andreotti, M.; Evangelisti, F.; Squerzanti, S.; Gambaccini, M.; Albergo, S.; Cappello, G.; Tricomi, A.; Veltri, M.; Adriani, O.; Borgheresi, R.; Graziani, G.; Passaleva, G.; Serban, A.; Starodubtsev, O.; Variola, A.; Palumbo, L.

2018-06-01

The Gamma Beam System of ELI-Nuclear Physics is a high brilliance monochromatic gamma source based on the inverse Compton interaction between an intense high power laser and a bright electron beam with tunable energy. The source, currently being assembled in Magurele (Romania), is designed to provide a beam with tunable average energy ranging from 0.2 to 19.5 MeV, rms energy bandwidth down to 0.5% and flux of about 108 photons/s. The system includes a set of detectors for the diagnostic and complete characterization of the gamma beam. To evaluate the spatial distribution of the beam a gamma beam profile imager is required. For this purpose, a detector based on a scintillator target coupled to a CCD camera was designed and a prototype was tested at INFN-Ferrara laboratories. A set of analytical calculations and Monte Carlo simulations were carried out to optimize the imager design and evaluate the performance expected with ELI-NP gamma beam. In this work the design of the imager is described in detail, as well as the simulation tools used and the results obtained. The simulation parameters were tuned and cross-checked with the experimental measurements carried out on the assembled prototype using the beam from an x-ray tube.

Gamma-Ray Bursts: An Overview

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

1995-01-01

A history and overview of the observed properties of gamma-ray bursts are presented. The phenomenon of gamma-ray bursts is without precedent in astronomy, having no observed property that would be a direct indicator of their distance and no counterpart object in another wavelength region. Their brief, random appearance only in the gamma-ray region has made their study difficult. The observed time profiles, spectral properties, and durations of gamma-ray bursts cover a wide range. All proposed models for their origin must be considered speculative. It is humbling to think that even after 25 years since their discovery, the distance scale of gamma-ray bursts is still very much debatable.

High energy gamma ray astronomy

NASA Technical Reports Server (NTRS)

Fichtel, Carl E.

1987-01-01

High energy gamma ray astronomy has evolved with the space age. Nonexistent twenty-five years ago, there is now a general sketch of the gamma ray sky which should develop into a detailed picture with the results expected to be forthcoming over the next decade. The galactic plane is the dominant feature of the gamma ray sky, the longitude and latitude distribution being generally correlated with galactic structural features including the spiral arms. Two molecular clouds were already seen. Two of the three strongest gamma ray sources are pulsars. The highly variable X-ray source Cygnus X-3 was seen at one time, but not another in the 100 MeV region, and it was also observed at very high energies. Beyond the Milky Way Galaxy, there is seen a diffuse radiation, whose origin remains uncertain, as well as at least one quasar, 3C 273. Looking to the future, the satellite opportunities for high energy gamma ray astronomy in the near term are the GAMMA-I planned to be launched in late 1987 and the Gamma Ray Observatory, scheduled for launch in 1990. The Gamma Ray Observatory will carry a total of four instruments covering the entire energy range from 30,000 eV to 3 x 10 to the 10th eV with over an order of magnitude increase in sensitivity relative to previous satellite instruments.

GammaM23K, gammaM232K, and gammaL77K single substitutions in the TF1-ATPase lower ATPase activity by disrupting a cluster of hydrophobic side chains.

PubMed

Bandyopadhyay, Sanjay; Allison, William S

2004-07-27

In crystal structures of the bovine F(1)-ATPase (MF(1)), the side chains of gammaMet(23), gammaMet(232), and gammaLeu(77) interact in a cluster. Substitution of the corresponding residues in the alpha(3)beta(3)gamma subcomplex of TF(1) with lysine lowers the ATPase activity to 2.3, 11, and 15%, respectively, of that displayed by wild-type. In contrast, TF(1) subcomplexes containing the gammaM(23)C, gammaM(232)C, and gammaL(77)C substitutions display 36, 36, and 130%, respectively, of the wild-type ATPase activity. The ATPase activity of the gammaM(23)C/gammaM(232)C double mutant subcomplex is 36% that of the wild-type subcomplex before and after cross-linking the introduced cysteines, whereas the ATPase activity of the gammaM(23)C/L(77)C double mutant increased from 50 to 85% that of wild-type after cross-linking the introduced cysteines. Only beta-beta cross-links formed when the alpha(3)(betaE(395)C)(3)gammaM(23)C double mutant was inactivated with CuCl(2). The overall results suggest that the attenuated ATPase of the mutant subcomplexes containing the gammaM(23)K, gammaL(77)K, and gammaM(232)K substitutions is caused by disruption of the cluster of hydrophobic amino acid side chains and that the midregion of the coiled-coil comprised of the amino- and carboxyl-terminal alpha helices of the gamma subunit does not undergo unwinding or major displacement from the side chain of gammaLeu(77) during ATP-driven rotation of the gamma subunit.

Compton Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

1991-01-01

This photograph shows the Compton Gamma-Ray Observatory (GRO) being deployed by the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-37 mission in April 1991. The GRO reentered Earth atmosphere and ended its successful mission in June 2000. For nearly 9 years, the GRO Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center (MSFC), kept an unblinking watch on the universe to alert scientists to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of stars, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in the BATSE science program.

Compton Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

1991-01-01

This photograph shows the Compton Gamma-Ray Observatory being released from the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-35 mission in April 1991. The GRO reentered the Earth's atmosphere and ended its successful mission in June 2000. For nearly 9 years, GRO's Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center, kept an unblinking watch on the universe to alert scientist to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of star, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in BATSE's science program.

Gamma Oscillations and Visual Binding

NASA Astrophysics Data System (ADS)

Robinson, Peter A.; Kim, Jong Won

2006-03-01

At the root of visual perception is the mechanism the brain uses to analyze features in a scene and bind related ones together. Experiments show this process is linked to oscillations of brain activity in the 30-100 Hz gamma band. Oscillations at different sites have correlation functions (CFs) that often peak at zero lag, implying simultaneous firing, even when conduction delays are large. CFs are strongest between cells stimulated by related features. Gamma oscillations are studied here by modeling mm-scale patchy interconnections in the visual cortex. Resulting predictions for gamma responses to stimuli account for numerous experimental findings, including why oscillations and zero-lag synchrony are associated, observed connections with feature preferences, the shape of the zero-lag peak, and variations of CFs with attention. Gamma waves are found to obey the Schroedinger equation, opening the possibility of cortical analogs of quantum phenomena. Gamma instabilities are tied to observations of gamma activity linked to seizures and hallucinations.

Space instrumentation for gamma-ray astronomy

NASA Astrophysics Data System (ADS)

Teegarden, B. J.

1999-02-01

The decade of the 1990s has witnessed a renaissance in the field of gamma-ray astronomy. The seminal event was the launch of the Compton Gamma-Ray Observatory (CGRO) in April 1991. There have been a flood of major discoveries from CGRO including breakthroughs in gamma-ray bursts, annihilation radiation, and blazars. The Italian SAX satellite was launched in April 1996. Although not primarily a gamma-ray mission, it has added a new dimension to our understanding of gamma-ray bursts. Along with these new discoveries a firm groundwork has been laid for missions and new technology development that should maintain a healthy and vigorous field throughout most of the next decade. These include the ESA INTEGRAL mission (INTErnational Gamma-Ray Astrophysics Laboratory, to be launched in mid-2001) and the NASA GLAST mission (Gamma-Ray Large Area Space Telescope) with a likely launch in the middle of the next decade. These two missions will extend the observational capabilities well beyond those of CGRO. New technologies (to gamma-ray astronomy), such as cooled germanium detectors, silicon strip detectors, and CdTe detectors are planned for these new missions. Additional promising new technologies such as CdZnTe strip detectors, scintillator fibers, and a gamma-ray lens for future gamma-ray astronomy missions are under development in laboratories around the world.

A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

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

Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P

2014-08-01

A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> etamore » p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.« less

Dose-effect relation between daily ethanol intake in the range 0-70 grams and %CDT value: validation of a cut-off value.

PubMed

Schellenberg, François; Schwan, Raymund; Mennetrey, Louise; Loiseaux, Marie-Nadia; Pagès, Jean Christophe; Reynaud, Michel

2005-01-01

To evaluate the ability to infer alcohol consumption using the %CDT (carbohydrate deficient transferrin) immunoassay (Axis Shield). One hundred and eighty-three healthy subjects (143 men, 40 women) undergoing a routine medical check-up at their workplace declared frequency and quantity of alcohol consumption covering the last 4 weeks. Seven sub-groups were made up from this population, according to daily ethanol intake and by increments of 10 g from 0 to 70 g/day. A reference group that consisted of 133 healthy teetotallers (74 men, 59 women) was recruited by occupational medicine in the same conditions as the 183 subjects of the study. Percentage CDT and gamma glutamyl transferase (GGT) were assayed on a fasting blood sample. There was a proportional dose-response effect of daily ethanol intake on %CDT values in the range of 0-70 g per day. A threshold effect on %CDT values for patients having an alcohol intake of over 40 g per day was found, an effect which was not observed for GGT activity. The kit has clinical usefulness, and the value of 2.6% proposed by the manufacturer for the cut-off for hazardous drinking in both sexes has been validated.

Zingiber officinale acts as a nutraceutical agent against liver fibrosis

PubMed Central

2011-01-01

Background/objective Zingiber officinale Roscoe (ginger) (Zingiberaceae) has been cultivated for thousands of years both as a spice and for medicinal purposes. Ginger rhizomes successive extracts (petroleum ether, chloroform and ethanol) were examined against liver fibrosis induced by carbon tetrachloride in rats. Results The evaluation was done through measuring antioxidant parameters; glutathione (GSH), total superoxide dismutase (SOD) and malondialdehyde (MDA). Liver marker enzymes; succinate and lactate dehydrogenases (SDH and LDH), glucose-6-phosphatase (G-6-Pase), acid phosphatase (AP), 5'- nucleotidase (5'NT) and liver function enzymes; aspartate and alanine aminotransferases (AST and ALT) as well as cholestatic markers; alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total bilirubin were estimated. Liver histopathological analysis and collagen content were also evaluated. Treatments with the selected extracts significantly increased GSH, SOD, SDH, LDH, G-6-Pase, AP and 5'NT. However, MDA, AST, ALT ALP, GGT and total bilirubin were significantly decreased. Conclusions Extracts of ginger, particularly the ethanol one resulted in an attractive candidate for the treatment of liver fibrosis induced by CCl4. Further studies are required in order to identify the molecules responsible of the pharmacological activity. PMID:21689445

Formation of gamma(sup prime)-Ni3Al via the Peritectoid Reaction: gamma + beta (+ Al2O3)=gamma(sup prime)(+ Al2O3)

NASA Technical Reports Server (NTRS)

Copeland, Evan

2008-01-01

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8-32 at.%Al and temperature range T=1400-1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma(sup prime)-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3)=gamma + Beta(+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%al (at an unknown oxygen content). The {gamma + Beta (+Al2O3} phase field is stable over the temperature range 1633-1640 K, and gamma(sup prime)-Ni3Al forms via the peritectoid, gamma + Beta (+ Al2O3)=gamma(sup prime) (+ Al2O3), at 1633 +/- 1 K. This behavior is consistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(sup prime)-Ni2Al phase field.

Ideal cardiovascular health predicts lower risk of abnormal liver enzymes levels in the Chilean National Health Survey (2009-2010).

PubMed

García-Hermoso, Antonio; Hackney, Anthony C; Ramírez-Vélez, Robinson

2017-01-01

High levels of gamma glutamyltransferase (gamma-GT) and alanine aminotransferase (ALT), as well as fatty liver index (FLI) has been associated with higher cardiovascular disease risk factors in adults. The aim of this study was to examine the relationship between gamma-GT, ALT, and fatty liver index FLI levels across a gradient number of ideal cardiovascular health metrics in a representative sample of adults from the Chilean National Health Survey 2009-2010. Data from 1,023 men and 1,449 women (≥ 15 years) from the Chilean Health Survey 2009-2010 were analyzed. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet adherence) and three factors (total cholesterol, blood pressure and fasting glucose). Adults were grouped into three categories according to their number of ideal cardiovascular health metrics: ideal (5-7 metrics), intermediate (3-4 metrics), and poor (0-2 metrics). Blood levels of gamma-GT and ALT were measured and the FLI was calculated. A higher number of ideal cardiovascular health index metric was associated with lower gamma-GT, ALT and FLI (p from trend analysis <0.001). Also, adults meeting at least 3-4 metrics were predicted less likely to have prevalence of abnormal levels of gamma-GT and FLI (p<0.001) compared to adults who met only 0-2 metrics. These findings reinforce the usefulness of the ideal cardiovascular health metrics proposed by the American Heart Association as a tool to identify target subjects and promote cardiovascular health in South-American adults.

Effect of lignin on oxidative stress in chickens fed a diet contaminated with zearalenone.

PubMed

Grešáková, L'ubomíra; Bořutová, Radka; Faix, Stefan; Plachá, Iveta; Cobanová, Klaudia; Košíková, Božena; Leng, L'ubomír

2012-03-01

The effect of lignin supplementation to a diet contaminated with zearalenone (ZEA) on antioxidant status was studied in female chickens of the ISA BROWN laying strain. From the day of hatching to 2 weeks of age, four groups of chickens were fed the same uncontaminated control diet. After 14 days, Group 1 (control) continued to receive the uncontaminated diet, while Group 2 was fed an identical diet enriched with 0.5% chemically modified lignin. Simultaneously, chickens of Group 3 were switched to a diet contaminated with 7.9 mg/kg ZEA and those of Group 4 to an identical contaminated diet supplemented with 0.5% lignin. At 6 weeks of age blood and tissue samples were collected. Feeding of a diet contaminated with a high level of ZEA resulted in elevated glutathione peroxidase (GPx) activity in the duodenal mucosa and kidney tissues, and an increased γ-glutamyltransferase (GGT) activity in the plasma, indicative of oxidative stress. In the liver tissue, no mycotoxin-induced response in GPx and thioredoxin reductase (TrxR) activities occurred, and the malondialdehyde (MDA) level was even reduced. Neither the plasma levels of retinol and α-tocopherol nor the activities of superoxide dismutase in erythrocytes and GPx in blood were affected in birds fed the contaminated diet. The only effect of lignin supplemented to the contaminated feed was that it prevented the increase of GPx activity in the duodenal mucosa as an indicator of oxidative stress.

Evaluation of gamma interferon (IFN-gamma)-induced protein 10 (IP-10) responses for detection of cattle infected with Mycobacterium bovis: comparisons to IFN-gamma responses

USDA-ARS?s Scientific Manuscript database

Gamma interferon (IFN-gamma)-induced protein 10 (IP-10) has recently shown promise as a diagnostic biomarker of Mycobacterium tuberculosis infection of humans. The aim of the current study was to compare IP-10 and IFN-gamma responses upon Mycobacterium bovis infection in cattle using archived sample...

Cell death is induced by ciglitazone, a peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonist, independently of PPAR{gamma} in human glioma cells

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

Lee, Myoung Woo; Kim, Dae Seong; Kim, Hye Ryung

Highlights: Black-Right-Pointing-Pointer Greater than 30 {mu}M ciglitazone induces cell death in glioma cells. Black-Right-Pointing-Pointer Cell death by ciglitazone is independent of PPAR{gamma} in glioma cells. Black-Right-Pointing-Pointer CGZ induces cell death by the loss of MMP via decreased Akt. -- Abstract: Peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) regulates multiple signaling pathways, and its agonists induce apoptosis in various cancer cells. However, their role in cell death is unclear. In this study, the relationship between ciglitazone (CGZ) and PPAR{gamma} in CGZ-induced cell death was examined. At concentrations of greater than 30 {mu}M, CGZ, a synthetic PPAR{gamma} agonist, activated caspase-3 and induced apoptosis inmore » T98G cells. Treatment of T98G cells with less than 30 {mu}M CGZ effectively induced cell death after pretreatment with 30 {mu}M of the PPAR{gamma} antagonist GW9662, although GW9662 alone did not induce cell death. This cell death was also observed when cells were co-treated with CGZ and GW9662, but was not observed when cells were treated with CGZ prior to GW9662. In cells in which PPAR{gamma} was down-regulated cells by siRNA, lower concentrations of CGZ (<30 {mu}M) were sufficient to induce cell death, although higher concentrations of CGZ ( Greater-Than-Or-Slanted-Equal-To 30 {mu}M) were required to induce cell death in control T98G cells, indicating that CGZ effectively induces cell death in T98G cells independently of PPAR{gamma}. Treatment with GW9662 followed by CGZ resulted in a down-regulation of Akt activity and the loss of mitochondrial membrane potential (MMP), which was accompanied by a decrease in Bcl-2 expression and an increase in Bid cleavage. These data suggest that CGZ is capable of inducing apoptotic cell death independently of PPAR{gamma} in glioma cells, by down-regulating Akt activity and inducing MMP collapse.« less

Comparative gene expression profiles induced by PPAR{gamma} and PPAR{alpha}/{gamma} agonists in rat hepatocytes

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

Rogue, Alexandra; Universite de Rennes 1, 35065 Rennes Cedex; Biologie Servier, 45520 Gidy

2011-07-01

Species-differential toxic effects have been described with PPAR{alpha} and PPAR{gamma} agonists between rodent and human liver. PPAR{alpha} agonists (fibrates) are potent hypocholesterolemic agents in humans while they induce peroxisome proliferation and tumors in rodent liver. By contrast, PPAR{gamma} agonists (glitazones) and even dual PPAR{alpha}/{gamma} agonists (glitazars) have caused idiosyncratic hepatic and nonhepatic toxicities in human without evidence of any damage in rodent during preclinical studies. The mechanisms involved in such differences remain largely unknown. Several studies have identified the major target genes of PPAR{alpha} agonists in rodent liver while no comprehensive analysis has been performed on gene expression changes inducedmore » by PPAR{gamma} and dual PPAR{alpha}/{gamma} agonists. Here, we investigated transcriptomes of rat hepatocytes after 24 h treatment with two PPAR{gamma} (troglitazone and rosiglitazone) and two PPAR{alpha}/{gamma} (muraglitazar and tesaglitazar) agonists. Although, hierarchical clustering revealed a gene expression profile characteristic of each PPAR agonist class, only a limited number of genes was specifically deregulated by glitazars. Functional analyses showed that many genes known as PPAR{alpha} targets were also modulated by both PPAR{gamma} and PPAR{alpha}/{gamma} agonists and quantitative differences in gene expression profiles were observed between these two classes. Moreover, most major genes modulated in rat hepatocytes were also found to be deregulated in rat liver after tesaglitazar treatment. Taken altogether, these results support the conclusion that differential toxic effects of PPAR{alpha} and PPAR{gamma} agonists in rodent liver do not result from transcriptional deregulation of major PPAR target genes but rather from qualitative and/or quantitative differential responses of a small subset of genes.« less

Gamma Ray Pulsars: Multiwavelength Observations

NASA Technical Reports Server (NTRS)

Thompson, David J.

2004-01-01

High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. For all the known gamma-ray pulsars, multiwavelength observations and theoretical models based on such observations offer the prospect of gaining a broad understanding of these rotating neutron stars. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2006, will provide a major advance in sensitivity, energy range, and sky coverage.

Chromosomal localization and partial genomic structure of the human peroxisome proliferator activated receptor-gamma (hPPAR gamma) gene.

PubMed

Beamer, B A; Negri, C; Yen, C J; Gavrilova, O; Rumberger, J M; Durcan, M J; Yarnall, D P; Hawkins, A L; Griffin, C A; Burns, D K; Roth, J; Reitman, M; Shuldiner, A R

1997-04-28

We determined the chromosomal localization and partial genomic structure of the coding region of the human PPAR gamma gene (hPPAR gamma), a nuclear receptor important for adipocyte differentiation and function. Sequence analysis and long PCR of human genomic DNA with primers that span putative introns revealed that intron positions and sizes of hPPAR gamma are similar to those previously determined for the mouse PPAR gamma gene[13]. Fluorescent in situ hybridization localized hPPAR gamma to chromosome 3, band 3p25. Radiation hybrid mapping with two independent primer pairs was consistent with hPPAR gamma being within 1.5 Mb of marker D3S1263 on 3p25-p24.2. These sequences of the intron/exon junctions of the 6 coding exons shared by hPPAR gamma 1 and hPPAR gamma 2 will facilitate screening for possible mutations. Furthermore, D3S1263 is a suitable polymorphic marker for linkage analysis to evaluate PPAR gamma's potential contribution to genetic susceptibility to obesity, lipoatrophy, insulin resistance, and diabetes.

Structure and creep rupture properties of directionally solidified eutectic gamma/gamma-prime-alpha alloy

NASA Technical Reports Server (NTRS)

Whittenberger, J. D.; Wirth, G.

1982-01-01

A simple ternary gamma/gamma-prime-alpha alloy of nominal composition (wt-%) Ni-32Mo-6Al has been directionally solidified at 17 mm/h and tested in creep rupture at 1073, 1173, and 1273 K. A uniform microstructure consisting of square-shaped Mo fibers in a gamma + gamma-prime matrix was found despite some variation in the molybdenum and aluminum concentrations along the growth direction. Although the steady-state creep rate is well described by the normal stress temperature equation, the stress exponent (12) and the activation energy (580 kJ/mol) are high. The rupture behavior is best characterized by the Larson-Miller parameter where the constant equals 20.

[Somatic treatments in psychiatry: A descriptive study of laboratory tests and systematic involvement in terms of overall care].

PubMed

Bensa, Q; Auxéméry, Y

2017-05-01

Somatic suffering concerns mental health in many ways, but numerous psychiatrists are still reluctant to take an interest in somatic care due to a supposed lack of expertise and an alteration of the psychotherapeutic link, whilst in parallel numerous fellow physicians are quite apprehensive about treating patients with mental disorders. We have undertaken a targeted clinical audit regarding the somatic treatment of in-patients in a psychiatric unit to propose the implementation of measures of improvement. Our study focused on the identification and treatment of abnormal liver function tests, a subject that has been overlooked in the literature, yet from clinical experience the results are often abnormal in psychiatric unit in-patients. We analysed retrospectively over a period of two years the medical records of psychiatric unit in-patients with abnormal results for at least one of the following hepatic markers: aspartate-aminotransferase (AST), alanine transaminase (ALT), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP) and bilirubin. In total, 188 liver test results were abnormal, with an average of 1.7 per patient. The abnormal test results were in decreasing order: elevation in GGT (80 % of patients), elevation in transaminases (65.5 % for each), elevation in ALP (19.1 %) and elevation in bilirubin (7.27 %). Abnormal transaminase levels were lower than 10N, with a peak between 1N and 3N for ALT and a peak between 1N and 5N for AST. The elevation in GGT was between 1N and 34N, although 71.6 % of these values were below 5N. ALP was below 3N. The medical history was traced in 93.6 % of the records. A somatic clinical examination was only reported in 39 records (35.5 %) and was carried out by a hepato-gastroenterologist (HGE) in 30.8 % of cases, the establishment's emergency physician in 25.7 % of cases and the psychiatrists in 12.9 % of cases. Patients with abnormal liver function test results frequently underwent other biological and

The development of gamma-gamma-prime lamellar structures in a nickel-base superalloy during elevated temperature mechanical testing

NASA Technical Reports Server (NTRS)

Mackay, R. A.; Ebert, L. J.

1985-01-01

The kinetics of the formation and subsequent development of the directional coarsening of the gamma-prime precipitate in model Ni-Al-Mo-Ta superalloy single crystals are examined during tensile creep under various stress levels at 982 and 1038 C. Special attention is given to the gamma and gamma-prime relation to creep time and strain in order to trace the changing gamma-gamma-prime morphology. Directional coarsening of gamma-prime is found to begin during primary creep and its rate is shown to increase with an increase in temperature or stress level. The length of gamma-prime thickness increased linearly with time up to a plateau reached after the onset of steady state creep. The raft thickness, equal to the gamma-prime size, remained constant at this initial value up through the onset of the tertiary creep. The interlaminar spacing indicates the stability of directionally coarsened structure.

Gamma-hadron families and scaling violation

NASA Technical Reports Server (NTRS)

Gaisser, T. K.; Stanev, T.; Wrotniak, J. A.

1985-01-01

For three different interaction models we have simulated gamma-hadron families, including the detector (Pamir emulsion chamber) response. Rates of gamma families, hadrons, and hadron-gamma ratios were compared with experiments.

The Gamma-Ray Imager GRI

NASA Astrophysics Data System (ADS)

Wunderer, Cornelia B.; GRI Collaboration

2006-09-01

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are the major science themes that are addressed in the gamma-ray regime. With the INTEGRAL observatory, ESA has provided a unique tool to the astronomical community revealing hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes. While INTEGRAL provides the global overview over the soft gamma-ray sky, there is a growing need to perform deeper, more focused investigations of gamma-ray sources. In soft X-rays a comparable step was taken going from the Einstein and the EXOSAT satellites to the Chandra and XMM/Newton observatories. Technological advances in the past years in the domain of gamma-ray focusing using Laue diffraction and multilayer coated mirror techniques have paved the way towards a gamma-ray mission, providing major improvements compared to past missions regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow to study particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

The Andromeda galaxy in gamma-rays

NASA Technical Reports Server (NTRS)

Oezel, M. E.; Berkhuijsen, E. M.

1987-01-01

Implications of high-energy gamma-ray observations of the Andromeda galaxy with the next generation of satellites Gamma-1 and GRO are discussed in the context of the origin of cosmic rays and gamma-ray processes. The present estimate of the total gamma-ray flux of this galaxy at energies above 100 MeV is a factor of about three less than previous estimates.

Structure of Bacillus subtilis γ-glutamyltranspeptidase in complex with acivicin: diversity of the binding mode of a classical and electrophilic active-site-directed glutamate analogue

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

Ida, Tomoyo; Suzuki, Hideyuki; Fukuyama, Keiichi

2014-02-01

The binding modes of acivicin, a classical and an electrophilic active-site-directed glutamate analogue, to bacterial γ-glutamyltranspeptidases were found to be diverse. γ-Glutamyltranspeptidase (GGT) is an enzyme that plays a central role in glutathione metabolism, and acivicin is a classical inhibitor of GGT. Here, the structure of acivicin bound to Bacillus subtilis GGT determined by X-ray crystallography to 1.8 Å resolution is presented, in which it binds to the active site in a similar manner to that in Helicobacter pylori GGT, but in a different binding mode to that in Escherichia coli GGT. In B. subtilis GGT, acivicin is bound covalentlymore » through its C3 atom with sp{sup 2} hybridization to Thr403 O{sup γ}, the catalytic nucleophile of the enzyme. The results show that acivicin-binding sites are common, but the binding manners and orientations of its five-membered dihydroisoxazole ring are diverse in the binding pockets of GGTs.« less

Directional gamma detector

DOEpatents

LeVert, Francis E.; Cox, Samson A.

1981-01-01

An improved directional gamma radiation detector has a collector sandwiched etween two layers of insulation of varying thicknesses. The collector and insulation layers are contained within an evacuated casing, or emitter, which releases electrons upon exposure to gamma radiation. Delayed electrons and electrons entering the collector at oblique angles are attenuated as they pass through the insulation layers on route to the collector.

Gamma ray pulsars

NASA Technical Reports Server (NTRS)

Oegelman, H.; Ayasli, S.; Hacinliyan, A.

1976-01-01

Recent data from the high energy gamma ray experiment have revealed the existence of four pulsars emitting photons above 35 MeV. An attempt is made to explain the gamma ray emission from these pulsars in terms of an electron-photon cascade that develops in the magnetosphere of the pulsar. Although there is very little material above the surface of the pulsar, the very intense magnetic fields correspond to many radiation lengths which cause electrons to emit photons via magnetic bremsstrahlung and these photons to pair produce. The cascade develops until the mean photon energy drops below the pair production threshold which happens to be in the gamma ray range; at this stage the photons break out from the source.

Highlights of GeV Gamma-Ray Astronomy

NASA Technical Reports Server (NTRS)

Thompson, David J.

2010-01-01

Because high-energy gamma rays are primarily produced by high-energy particle interactions, the gamma-ray survey of the sky by the Fermi Gamma-ray Space Telescope offers a view of sites of cosmic ray production and interactions. Gamma-ray bursts, pulsars, pulsar wind nebulae, binary sources, and Active Galactic Nuclei are all phenomena that reveal particle acceleration through their gamma-ray emission. Diffuse Galactic gamma radiation, Solar System gamma-ray sources, and energetic radiation from supernova remnants are likely tracers of high-energy particle interactions with matter and photon fields. This paper will present a broad overview of the constantly changing sky seen with the Large Area Telescope (LAT) on the Fermi spacecraft.

Hard gamma radiation background from coding collimator of gamma telescope under space experiment conditions

NASA Astrophysics Data System (ADS)

Aleksandrov, A. P.; Berezovoy, A. N.; Galper, A. M.; Grachev, V. M.; Dmitrenko, V. V.; Kirillov-Ugryumov, V. G.; Lebedev, V. V.; Lyakhov, V. A.; Moiseyev, A. A.; Ulin, S. Y.

1985-09-01

Coding collimators are used to improve the angular resolution of gamma-ray telescopes at energies above 50 MeV. However, the interaction of cosmic rays with the collimation material can lead to the appearance of a gamma-ray background flux which can have a deleterious effect on measurement efficiency. An experiment was performed on the Salyut-6-Soyuz spacecraft system with the Elena-F small-scale gamma-ray telescope in order to measure the magnitude of this background. It is shown that, even at a zenith angle of approximately zero degrees (the angle at which the gamma-ray observations are made), the coding collimator has only an insignificant effect on the background conditions.

Spontaneous apoptosis, oxidative status and immunophenotype markers in blood lymphocytes of AIDS patients.

PubMed

Losa, G A; Graber, R

2000-01-01

Peripheral blood mononuclear cells (PBMC) from 251 HIV-positive drug abusers of known clinical stage and from 40 healthy donors were tested for conventional immunologic markers (CD3, CD4, CD8, CD19, CD14, CD16/CD56, CD45 and HLA-DR). Additional cell parameters and the occurrence of spontaneous apoptosis (programmed cell death) were investigated on freshly isolated PBMC by flow cytometric measurement of either annexin-V bound to plasma membrane phosphatidylserine or propidium iodide uptake. The activity of gamma-glutamyltransferase (gamma-GT), an ectoenzyme contributing to the synthesis of the intracellular antioxidant glutathione (GSH) and involved in early apoptosis, was also determined in these cells. Immunocompetent T-cell counts were lower in HIV+ patients, with the exception of CD8+ and HLA-DR+ lymphocytes. The external binding of annexin-V was significantly higher in HIV+ PBMC and occurred in both CD8+ and CD4+ T-lymphocyte subsets. The activity of gamma-GT, was significantly lower in the PBMC from HIV+ patients, indicating that the redox status of PBMC may be affected in HIV+ individuals. Finally, the most dominant features characterising patients receiving antiretroviral therapy were greater long-term stability in the distribution of various cell parameters excepted the level of apoptosis.

Spontaneous Gamma Activity in Schizophrenia.

PubMed

Hirano, Yoji; Oribe, Naoya; Kanba, Shigenobu; Onitsuka, Toshiaki; Nestor, Paul G; Spencer, Kevin M

2015-08-01

A major goal of translational neuroscience is to identify neural circuit abnormalities in neuropsychiatric disorders that can be studied in animal models to facilitate the development of new treatments. Oscillations in the gamma band (30-100 Hz) of the electroencephalogram have received considerable interest as the basic mechanisms underlying these oscillations are understood, and gamma abnormalities have been found in schizophrenia (SZ). Animal models of SZ based on hypofunction of the N-methyl-d-aspartate receptor (NMDAR) demonstrate increased spontaneous broadband gamma power, but this phenomenon has not been identified clearly in patients with SZ. To examine spontaneous gamma power and its relationship to evoked gamma oscillations in the auditory cortex of patients with SZ. We performed a cross-sectional study including 24 patients with chronic SZ and 24 matched healthy control participants at the Veterans Affairs Boston Healthcare System from January 1, 2009, through December 31, 2012. Electroencephalograms were obtained during auditory steady-state stimulation at multiple frequencies (20, 30, and 40 Hz) and during a resting state in 18 participants in each group. Electroencephalographic activity in the auditory cortex was estimated using dipole source localization. Auditory steady-state response (ASSR) measures included the phase-locking factor and evoked power. Spontaneous gamma power was measured as induced (non-phase-locked) gamma power in the ASSR data and as total gamma power in the resting-state data. The ASSR phase-locking factor was reduced significantly in patients with SZ compared with controls for the 40-Hz stimulation (mean [SD], 0.075 [0.028] vs 0.113 [0.065]; F1,46 = 6.79 [P = .012]) but not the 20- or the 30-Hz stimulation (0.042 [0.038] vs 0.043 [0.034]; F1,46 = 0.006 [P = .938] and 0.084 [0.040] vs 0.098 [0.050]; F1,46 = 1.605 [P = .212], respectively), repeating previous findings. The mean [SD] broadband-induced (30

EFFICIENCY OF BORAGE SEEDS OIL AGAINST GAMMA IRRADIATION-INDUCED HEPATOTOXICITY IN MALE RATS: POSSIBLE ANTIOXIDANT ACTIVITY.

PubMed

Khattab, Hala A H; Abdallah, Inas Z A; Yousef, Fatimah M; Huwait, Etimad A

2017-01-01

Borage ( Borago officinal L.) is an annual herbaceous plant of great interest because its oil contains a high percentage of γ-linolenic acid (GLA). The present work was carried out to detect fatty acids composition of the oil extracted from borage seeds (BO) and its potential effectiveness against γ-irradiation- induced hepatotoxicity in male rats. GC-MS analysis of fatty acids methyl esters of BO was performed to identify fatty acids composition. Sixty rats were divided into five groups (12 rats each): Control, irradiated; rats were exposed to (6.5 Gy) of whole body γ-radiation, BO (50 mg/kg b.wt), irradiated BO post-treated and irradiated BO prepost-treated. Six rats from each group were sacrificed at two time intervals 7 and 15 days post-irradiation. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT) levels, lipids profile, as well as serum and hepatic reduced glutathione (GSH) and lipid peroxide (malondialdehyde) (MDA) levels were assessed. Histopathological examination of liver sections were also carried out. The results showed that the high contents of BO extracted by cold pressing, were linoleic acid (34.23%) and GLA (24.79%). Also, oral administration of BO significantly improved serum levels of liver enzymes, lipids profile, as well as serum and hepatic GSH and MDA levels (p<0.001) as compared with irradiated rats after 15 days post irradiation. Moreover, it exerted marked amelioration against irradiation-induced histopathological changes in liver tissues. The improvement was more pronounced in irradiated BO prepost-treated group than irradiated BO post-treated. BO has a beneficial role in reducing hepatotoxicity and oxidative stress induced by radiation exposure. Therefore, BO may be used as a beneficial supplement for patients during radiotherapy treatment.

Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources

DOE PAGES

Nesci, R.; Tosti, G.; Pursimo, T.; ...

2013-06-18

Context. We present that spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). Aims. In this paper we report the results of a one-year near-infrared (NIR) and optical monitoring of a sample of 22 AGN known to be gamma-ray emitters, aimed at discovering correlations between optical and gamma-ray emission. Methods. We observed our objects with the Rapid Eye Mount (REM) telescope in J,H,K, and R bands nearly twice every month during their visibility window and derived light curves and spectral indexes. We also analyzed the gamma-ray data from themore » Fermi gamma-ray Space Telescope, making weekly averages. Results. Six sources were never detected during our monitoring, proving to be fainter than their historical Two micron all sky survey (2MASS) level. All of the sixteen detected sources showed marked flux density variability, while the spectral indexes remained unchanged within our sensitivity limits. Steeper sources showed, on average, a larger variability. From the NIR light curves we also computed a variability speed index for each detected source. Only one source (PKS 0208-512) underwent an NIR flare during our monitoring. Half of the sources showed a regular flux density trend on a one-year time scale, but do not show any other peculiar characteristic. The broadband spectral index α ro appears to be a good proxy of the NIR spectral index only for BL Lac objects. No clear correlation between NIR and gamma-ray data is evident in our data, save for PKS 0537-441, PKS 0521-360, PKS 2155-304, and PKS 1424-418. In conclusion, the gamma-ray/NIR flux ratio showed a large spread, QSO being generally gamma-louder than BL Lac, with a marked correlation with the estimated peak frequency (ν peak) of the synchrotron emission.« less

Digital gamma-gamma coincidence HPGe system for environmental analysis.

PubMed

Marković, Nikola; Roos, Per; Nielsen, Sven Poul

2017-08-01

The performance of a new gamma-gamma coincidence spectrometer system for environmental samples analysis at the Center for Nuclear Technologies of the Technical University of Denmark (DTU) is reported. Nutech Coincidence Low Energy Germanium Sandwich (NUCLeGeS) system consists of two HPGe detectors in a surface laboratory with a digital acquisition system used to collect the data in time-stamped list mode with 10ns time resolution. The spectrometer is used in both anticoincidence and coincidence modes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selenium uptake through cystine transporter mediated by glutathione conjugation.

PubMed

Tobe, Takao; Ueda, Koji; Aoki, Akira; Okamoto, Yoshinori; Kojima, Nakao; Jinno, Hideto

2017-01-01

Selenium (Se) is an essential trace element and is regarded as a protective agent against cancer. In particular, antioxidant effects of selenoenzymes contribute to cancer prevention. Se can also produce reactive oxygen species and, thereby, exert cancer-selective cytotoxicity. Selenodiglutathione (SDG) is a primary Se metabolite conjugated to two glutathione (GSH) moieties. SDG increases intracellular Se accumulation and is more toxic than selenous acid (H 2 SeO 3 ), but the mechanisms for importing Se compounds into cells are not fully understood. Here, we propose a novel mechanism for importing Se, in the form of SDG. Cellular intake of Se compounds was assessed based on Se accumulation, as detected by ICP-MS. SDG incorporation was decreased in the presence of thiols (GSH, cysteine or their oxidized forms, GSSG and cystine), whereas H 2 SeO 3 uptake was increased by addition of GSH or cysteine. Cellular SDG uptake was decreased by pretreatment with specific inhibitors against gamma-glutamyl transpeptidase (GGT) or the cystine/glutamate antiporter (system x c - ). Furthermore, siRNA against xCT, which is the light chain component of system x c - , significantly decreased SDG incorporation. These data suggest an involvement of SDG in Se incorporation, with SDG processed at the cell surface by GGT, leading to formation of selenodicysteine which, in turn, is likely to be imported via xCT. Because GGT and xCT are highly expressed in cancer cells, these mechanisms mediated by the cystine transporter might underlie the cancer-selective toxicity of Se. In addition, the system described in our study appears to represent a physiological transport mechanism for the essential element Se.

High resolution mapping of the binding site on human IgG1 for Fc gamma RI, Fc gamma RII, Fc gamma RIII, and FcRn and design of IgG1 variants with improved binding to the Fc gamma R.

PubMed

Shields, R L; Namenuk, A K; Hong, K; Meng, Y G; Rae, J; Briggs, J; Xie, D; Lai, J; Stadlen, A; Li, B; Fox, J A; Presta, L G

2001-03-02

Immunoglobulin G (IgG) Fc receptors play a critical role in linking IgG antibody-mediated immune responses with cellular effector functions. A high resolution map of the binding site on human IgG1 for human Fc gamma RI, Fc gamma RIIA, Fc gamma RIIB, Fc gamma RIIIA, and FcRn receptors has been determined. A common set of IgG1 residues is involved in binding to all Fc gamma R; Fc gamma RII and Fc gamma RIII also utilize residues outside this common set. In addition to residues which, when altered, abrogated binding to one or more of the receptors, several residues were found that improved binding only to specific receptors or simultaneously improved binding to one type of receptor and reduced binding to another type. Select IgG1 variants with improved binding to Fc gamma RIIIA exhibited up to 100% enhancement in antibody-dependent cell cytotoxicity using human effector cells; these variants included changes at residues not found at the binding interface in the IgG/Fc gamma RIIIA co-crystal structure (Sondermann, P., Huber, R., Oosthuizen, V., and Jacob, U. (2000) Nature 406, 267-273). These engineered antibodies may have important implications for improving antibody therapeutic efficacy.

Gamma-ray line astrophysics

NASA Technical Reports Server (NTRS)

Lingenfelter, R. E.; Ramaty, R.

1986-01-01

Recent observations of gamma-ray line emission from solar flares, gamma-ray bursts, the galactic center, the interstellar medium and the jets of SS433 are reviewed. The implications of these observations on high energy processes in these sources are discussed.

Registered particles onboard identification in the various apertures of GAMMA-400 space gamma-telescope

NASA Astrophysics Data System (ADS)

Arkhangelskaja, Irene

2016-07-01

GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be the gamma-telescope onboard international satellite gamma-observatory designed for particle registration in the wide energy band. Its parameters are optimized for detection of gamma-quanta with the energy ˜ 100 GeV in the main aperture. The main scientific goals of GAMMA-400 are to investigate fluxes of γ-rays and the electron-positron cosmic ray component possibly generated by dark matter particles decay or annihilation and to search for and study in detail discrete γ-ray sources, to investigate the energy spectra of Galactic and extragalactic diffuse γ-rays, and to study γ-ray bursts and γ-emission from the active Sun. This article presents analysis of detected events identification procedures and energy resolution in three apertures provide particles registration both from upper and lateral directions based on GAMMA-400 modeling due special designed software. Time and segmentation methods are used to reject backsplash (backscattering particles created when high energy γ-rays interact with the calorimeter's matter and move in the opposite direction) in the main aperture while only energy deposition analysis allows to reject this effect in the additional and lateral ones. The main aperture provides the best angular (all strip layers information analysis) and energy (energy deposition in the all detectors studying) resolution in the energy range 0.1 - 3 × 10^{3} GeV. The energy resolution in this band is 1%. Triggers in the main aperture will be formed using information about particle direction provided by time of flight system and presence of charged particle or backsplash signal formed according to analysis of energy deposition in combination of all two-layers anticoincidence systems individual detectors. In the additional aperture gamma-telescope allows to register events in the energy band 10 × 10^{-3} - 3 × 10^{3} GeV. The additional aperture energy resolution provides due to

GRI: The Gamma-Ray Imager mission

NASA Astrophysics Data System (ADS)

Knödlseder, J.; Gri Consortium

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe While at lower wavebands the observed emission is generally dominated by thermal processes the gamma-ray sky provides us with a view on the non-thermal Universe Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood and nuclear reactions are synthesizing the basic constituents of our world Cosmic accelerators and cosmic explosions are the major science themes that are addressed in the gamma-ray regime With the INTEGRAL observatory ESA has provided a unique tool to the astronomical community and has put Europe in the lead in the field of gamma-ray astronomy INTEGRAL provides an unprecedented survey of the soft gamma-ray sky revealing hundreds of sources new classes of objects extraordinary views of antimatter annihilation in our Galaxy and fingerprints of recent nucleosynthesis processes While INTEGRAL has provided the global overview over the soft gamma-ray sky there is a growing need to perform deeper more focused investigations of gamma-ray sources In soft X-rays a comparable step was taken going from the Einstein satellite to the XMM Newton observatory Technological advances in the past years in the domain of gamma-ray focusing using Laue diffraction and multilayer-coated mirror techniques have paved the way towards a gamma-ray mission providing major improvements compared to past missions regarding sensitivity and angular resolution Such a

Gamma rays from Centaurus A

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

Gupta, Nayantara, E-mail: nayan@phy.iitb.ac.in

2008-06-15

Centaurus A, the cosmic ray accelerator a few Mpc away from us, is possibly one of the nearest sources of extremely high energy cosmic rays. We investigate whether the gamma ray data currently available from Centaurus A in the GeV-TeV energy band can be explained with only proton-proton interactions. We show that for a single power law proton spectrum, mechanisms of {gamma}-ray production other than proton-proton interactions are needed inside this radio-galaxy to explain the gamma ray flux observed by EGRET, upper limits from HESS/CANGAROO-III and the correlated extremely energetic cosmic ray events observed by the Pierre Auger experiment. Inmore » future, with better {gamma}-ray data, and simultaneous observation with {gamma}-ray and cosmic ray detectors, it will be possible to carry out such studies on different sources in more detail.« less

Application of gamma imaging techniques for the characterisation of position sensitive gamma detectors

NASA Astrophysics Data System (ADS)

Habermann, T.; Didierjean, F.; Duchêne, G.; Filliger, M.; Gerl, J.; Kojouharov, I.; Li, G.; Pietralla, N.; Schaffner, H.; Sigward, M.-H.

2017-11-01

A device to characterize position-sensitive germanium detectors has been implemented at GSI. The main component of this so called scanning table is a gamma camera that is capable of producing online 2D images of the scanned detector by means of a PET technique. To calibrate the gamma camera Compton imaging is employed. The 2D data can be processed further offline to obtain depth information. Of main interest is the response of the scanned detector in terms of the digitized pulse shapes from the preamplifier. This is an important input for pulse-shape analysis algorithms as they are in use for gamma tracking arrays in gamma spectroscopy. To validate the scanning table, a comparison of its results with a second scanning table implemented at the IPHC Strasbourg is envisaged. For this purpose a pixelated germanium detector has been scanned.

Simultaneous beta and gamma spectroscopy

DOEpatents

Farsoni, Abdollah T.; Hamby, David M.

2010-03-23

A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

Portable compton gamma-ray detection system

DOEpatents

Rowland, Mark S [Alamo, CA; Oldaker, Mark E [Pleasanton, CA

2008-03-04

A Compton scattered gamma-ray detector system. The system comprises a gamma-ray spectrometer and an annular array of individual scintillators. The scintillators are positioned so that they are arrayed around the gamma-ray spectrometer. The annular array of individual scintillators includes a first scintillator. A radiation shield is positioned around the first scintillator. A multi-channel analyzer is operatively connected to the gamma-ray spectrometer and the annular array of individual scintillators.

Very High-Energy Gamma-Ray Sources.

ERIC Educational Resources Information Center

Weekes, Trevor C.

1986-01-01

Discusses topics related to high-energy, gamma-ray astronomy (including cosmic radiation, gamma-ray detectors, high-energy gamma-ray sources, and others). Also considers motivation for the development of this field, the principal results to date, and future prospects. (JN)

Updated level scheme of 172Yb from 171Yb(nth, γ) reaction studied via gamma-gamma coincidence spectrometer

NASA Astrophysics Data System (ADS)

Nguyen, Ngoc Anh; Nguyen, Xuan Hai; Pham, Dinh Khang; Nguyen, Quang Hung; Ho, Huu Thang

2017-08-01

This paper provides the updated information on the level scheme of 172Yb nucleus studied via 171Yb(nth, γ) reaction using the gamma-gamma coincidence spectrometer at Dalat Nuclear Research Institute (Viet Nam). The latter is used because of its advantages in achieving the low Compton background as well as in identifying the correlated gamma transitions. We have detected in total the energies and intensities of 128 two-step gamma cascades corresponding to 79 primary transitions. By comparing the measured data with those extracted from the ENSDF library, 61 primary gamma transitions and corresponding energy levels together with 20 secondary gamma transitions are found to be the same as the ENSDF data. Beside that, 18 additional primary gamma transitions and corresponding energy levels plus 108 secondary ones are not found to currently exist in this library and they are therefore considered as the new data.

Measurement of the {sup 157}Gd(n,{gamma}) reaction with the DANCE {gamma} calorimeter array

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

Chyzh, A.; Dashdorj, D.; Lawrence Livermore National Laboratory, Livermore, California 94551

2011-07-15

The {sup 157}Gd(n,{gamma}) reaction was measured with the DANCE {gamma} calorimeter (consisting of 160 BaF{sub 2} scintillation detectors) at the Los Alamos Neutron Science Center. The multiplicity distributions of the {gamma} decay were used to determine the resonance spins up to E{sub n}=300 eV. The {gamma}-ray energy spectra for different multiplicities were measured for the s-wave resonances. The shapes of these spectra were compared with simulations based on the use of the DICEBOX statistical model code. Simulations showed that the scissors mode is required not only for the ground-state transitions but also for transitions between excited states.

Alcohol consumption and risk-factors for ischemic heart disease in Chuckchi inhabitants: clinical, biological and population studies.

PubMed

Chernobrovkina, T V; Arkavy, J V; Astakhova, T I

1991-01-01

Clinical, biochemical and epidemiological research has shown variations of serum enzymatic constellations (relatively high level of GGT in Chuckchi natives compared to nonnative newcomers). This difference leads to different unspecific body resistance to exogenous factors, particularly to histamine-liberators. The GGT system has also been linked to alcohol-induced clinical IHD. Based on these findings patients will be screened for GGT activity, which may serve as a marker for population phenotypes representative of high-risk groups. This deficiency in GGT may indicate a high risk for alcohol-related heart disease.

Lunar occultations for gamma-ray source measurements

NASA Technical Reports Server (NTRS)

Koch, David G.; Hughes, E. B.; Nolan, Patrick L.

1990-01-01

The unambiguous association of discrete gamma-ray sources with objects radiating at other wavelengths, the separation of discrete sources from the extended emission within the Galaxy, the mapping of gamma-ray emission from nearby galaxies and the measurement of structure within a discrete source cannot presently be accomplished at gamma-ray energies. In the past, the detection processes used in high-energy gamma-ray astronomy have not allowed for good angular resolution. This problem can be overcome by placing gamma-ray detectors on the moon and using the horizon as an occulting edge to achieve arcsec resolution. For purposes of discussion, this concept is examined for gamma rays above 100 MeV for which pair production dominates the detection process and locally-generated nuclear gamma rays do not contribute to the background.

Mercuric iodine room temperature gamma-ray detectors

NASA Technical Reports Server (NTRS)

Patt, Bradley E.; Markakis, Jeffrey M.; Gerrish, Vernon M.; Haymes, Robert C.; Trombka, Jacob I.

1990-01-01

high resolution mercuric iodide room temperature gamma-ray detectors have excellent potential as an essential component of space instruments to be used for high energy astrophysics. Mercuric iodide detectors are being developed both as photodetectors used in combination with scintillation crystals to detect gamma-rays, and as direct gamma-ray detectors. These detectors are highly radiation damage resistant. The list of applications includes gamma-ray burst detection, gamma-ray line astronomy, solar flare studies, and elemental analysis.

About cosmic gamma ray lines

NASA Astrophysics Data System (ADS)

Diehl, Roland

2017-06-01

Gamma ray lines from cosmic sources convey the action of nuclear reactions in cosmic sites and their impacts on astrophysical objects. Gamma rays at characteristic energies result from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. The gamma-ray line from the annihilation of positrons at 511 keV falls into the same energy window, although of different origin. We present here the concepts of cosmic gamma ray spectrometry and the corresponding instruments and missions, followed by a discussion of recent results and the challenges and open issues for the future. Among the lessons learned are the diffuse radioactive afterglow of massive-star nucleosynthesis in 26Al and 60Fe gamma rays, which is now being exploited towards the cycle of matter driven by massive stars and their supernovae; large interstellar cavities and superbubbles have been recognised to be of key importance here. Also, constraints on the complex processes making stars explode as either thermonuclear or core-collapse supernovae are being illuminated by gamma-ray lines, in this case from shortlived radioactivities from 56Ni and 44Ti decays. In particular, the three-dimensionality and asphericities that have recently been recognised as important are enlightened in different ways through such gamma-ray line spectroscopy. Finally, the distribution of positron annihilation gamma ray emission with its puzzling bulge-dominated intensity disctribution is measured through spatially-resolved spectra, which indicate that annihilation conditions may differ in different parts of our Galaxy. But it is now understood that a variety of sources may feed positrons into the interstellar medium, and their characteristics largely get lost during slowing down and propagation of positrons before annihilation; a recent microquasar flare was caught as an opportunity to see positrons annihilate at a source.

Detecting and Imaging of γ-Glutamytranspeptidase Activity in Serum, Live Cells, and Pathological Tissues with a High Signal-Stability Probe by Releasing a Precipitating Fluorochrome.

PubMed

Ou-Yang, Juan; Li, Yong-Fei; Wu, Ping; Jiang, Wen-Li; Liu, Hong-Wen; Li, Chun-Yan

2018-06-20

γ-Glutamytranspeptidase (GGT) is a significant tumor-related biomarker that overexpresses in several tumor cells. Accurate detection and imaging of GGT activity in serum, live cells, and pathological tissues hold great significance for cancer diagnosis, treatment, and management. Recently developed small molecule fluorescent probes for GGT tend to diffuse to the whole cytoplasm and then translocate out of live cells after enzymatic reaction, which make them fail to provide high spatial resolution and long-term imaging in biological systems. To address these problems, a novel fluorescent probe (HPQ-PDG) which releases a precipitating fluorochrome upon the catalysis of GGT is designed and synthesized. HPQ-PDG is able to detect GGT activity with high spatial resolution and good signal-stability. The large Stokes shift of the probe enables it to detect the activity of GGT in serum samples with high sensitivity. To our delight, the probe is used for imaging GGT activity in live cells with the ability of discriminating cancer cells from normal cells. What's more, we successfully apply it for pathological tissues imaging, with the results indicating that the potential application of HPQ-PDG in histopathological examination. All these results demonstrate the potential application of HPQ-PDG in the clinic.

75 FR 43099 - Airworthiness Directives; General Electric Company (GE) CT7-9C and -9C3 Turboprop Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

... GGT shaft for nonconforming land balance-cuts, and if found, removing the shaft from service. This... nonconforming GGT shaft land balance-cuts, which could result in the shaft failing before its published life... reports of 21 nonconforming land balance-cuts on GGT shafts, P/N 6068T44P02. The nonconforming land...

The relationship between gamma frequency and running speed differs for slow and fast gamma rhythms in freely behaving rats

PubMed Central

Zheng, Chenguang; Bieri, Kevin Wood; Trettel, Sean Gregory; Colgin, Laura Lee

2015-01-01

In hippocampal area CA1 of rats, the frequency of gamma activity has been shown to increase with running speed (Ahmed and Mehta, 2012). This finding suggests that different gamma frequencies simply allow for different timings of transitions across cell assemblies at varying running speeds, rather than serving unique functions. However, accumulating evidence supports the conclusion that slow (~25–55 Hz) and fast (~60–100 Hz) gamma are distinct network states with different functions. If slow and fast gamma constitute distinct network states, then it is possible that slow and fast gamma frequencies are differentially affected by running speed. In this study, we tested this hypothesis and found that slow and fast gamma frequencies change differently as a function of running speed in hippocampal areas CA1 and CA3, and in the superficial layers of the medial entorhinal cortex (MEC). Fast gamma frequencies increased with increasing running speed in all three areas. Slow gamma frequencies changed significantly less across different speeds. Furthermore, at high running speeds, CA3 firing rates were low, and MEC firing rates were high, suggesting that CA1 transitions from CA3 inputs to MEC inputs as running speed increases. These results support the hypothesis that slow and fast gamma reflect functionally distinct states in the hippocampal network, with fast gamma driven by MEC at high running speeds and slow gamma driven by CA3 at low running speeds. PMID:25601003

GammaLib and ctools. A software framework for the analysis of astronomical gamma-ray data

NASA Astrophysics Data System (ADS)

Knödlseder, J.; Mayer, M.; Deil, C.; Cayrou, J.-B.; Owen, E.; Kelley-Hoskins, N.; Lu, C.-C.; Buehler, R.; Forest, F.; Louge, T.; Siejkowski, H.; Kosack, K.; Gerard, L.; Schulz, A.; Martin, P.; Sanchez, D.; Ohm, S.; Hassan, T.; Brau-Nogué, S.

2016-08-01

The field of gamma-ray astronomy has seen important progress during the last decade, yet to date no common software framework has been developed for the scientific analysis of gamma-ray telescope data. We propose to fill this gap by means of the GammaLib software, a generic library that we have developed to support the analysis of gamma-ray event data. GammaLib was written in C++ and all functionality is available in Python through an extension module. Based on this framework we have developed the ctools software package, a suite of software tools that enables flexible workflows to be built for the analysis of Imaging Air Cherenkov Telescope event data. The ctools are inspired by science analysis software available for existing high-energy astronomy instruments, and they follow the modular ftools model developed by the High Energy Astrophysics Science Archive Research Center. The ctools were written in Python and C++, and can be either used from the command line via shell scripts or directly from Python. In this paper we present the GammaLib and ctools software versions 1.0 that were released at the end of 2015. GammaLib and ctools are ready for the science analysis of Imaging Air Cherenkov Telescope event data, and also support the analysis of Fermi-LAT data and the exploitation of the COMPTEL legacy data archive. We propose using ctools as the science tools software for the Cherenkov Telescope Array Observatory.

Observation of gamma ray bursts and flares by the EGRET telescope on the Compton Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Schneid, E. J.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kwok, P. W.; Mattox, J. R.; Sreekumar, P.; Thompson, D. J.; Kanbach, G.

1992-01-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory has observed energetic gamma ray bursts and flares. On May 3, 1991, EGRET detected a gamma ray burst both in the energy measuring NaI (Tl) scintillator and independently in the spark chamber imaging assembly. The NaI spectra were accumulated by a special BURST mode of EGRET. The spectra were measured over a range from 1 to 200 MeV, in three sequential spectra of 1,2, and 4 seconds. During the peak of the burst, six individual gamma rays were detected in the spark chamber, allowing a determination of the burst arrival direction. The intense flares of June were also detected. A solar flare on June 4 was observed to last for several minutes and for a brief time, less than a minute, had significant emission of gamma rays exceeding 150 MeV.

A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic (22)Na/(7)Be activity ratio measurement.

PubMed

Zhang, Weihua; Ungar, Kurt; Stukel, Matthew; Mekarski, Pawel

2014-04-01

In this study, a digital gamma-gamma coincidence/anticoincidence spectrometer was developed and examined for low-level cosmogenic (22)Na and (7)Be in air-filter sample monitoring. The spectrometer consists of two bismuth germanate scintillators (BGO) and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The spectrometer design allows a more selective measurement of (22)Na with a significant background reduction by gamma-gamma coincidence events processing. Hence, the system provides a more sensitive way to quantify trace amounts of (22)Na than normal high resolution gamma spectrometry providing a critical limit of 3 mBq within a 20 h count. The use of a list-mode data acquisition technique enabled simultaneous determination of (22)Na and (7)Be activity concentrations using a single measurement by coincidence and anticoincidence mode respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gamma Ray Spectroscopy and SASSYER

NASA Astrophysics Data System (ADS)

Pauerstein, Benjamin; Bonniwell, Cain; Allmond, J. M.; Beausang, C. W.

2009-10-01

An experiment was performed to study the Gd and Tb nuclei resulting from a 27 MeV proton beam on a 156Gd target. This was conducted at Lawrence Berkeley National Laboratory using the STARS/LIBERACE array. The main focus of the experiment was on charged particle channels (p,d) into 155Gd and (p,t) into 154Gd. However, the trigger was either gamma-gamma or particle-gamma so new data was also obtained on 155Tb nuclei following fusion evaporation reactions. Preliminary analysis was conducted at Wright Nuclear Structure Lab where RADWARE programs were used to analyze the data and search for unknown gamma rays. A second, separate, experiment was conducted using the SASSYER (a gas-filled separator at Yale). In this experiment, fission fragments from a 252Cf source were focused to a DSSD and a Ge detector was used to search for either gamma-decay from long lived isomers in the fission fragments or to find gammas from recoil-beta-decay tagging on the fission fragments. The data collection seems to have gone smoothly, and the data is currently being sorted for analysis. This work was supported by the US Department of Energy under grant numbers DE-FG02-52NA26206 and DE-FG02-05ER41379.

Gamma ray spectroscopy in astrophysics. [conferences

NASA Technical Reports Server (NTRS)

Cline, T. L. (Editor); Ramaty, R. (Editor)

1978-01-01

Experimental and theoretical aspects of gamma ray spectroscopy in high energy astrophysics are discussed. Line spectra from solar, stellar, planetary, and cosmic gamma rays are examined as well as HEAO investigations, the prospects of a gamma ray observatory, and follow-on X-ray experiments in space.

Attrition resistant gamma-alumina catalyst support

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

Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

2006-03-14

A .gamma.-alumina catalyst support having improved attrition resistance produced by a method comprising the steps of treating a particulate .gamma.-alumina material with an acidic aqueous solution comprising water and nitric acid and then, prior to adding any catalytic material thereto, calcining the treated .gamma.-alumina.

Pathophysiologic roles of the fibrinogen gamma chain.

PubMed

Farrell, David H

2004-05-01

Fibrinogen binds through its gamma chains to cell surface receptors, growth factors, and coagulation factors to perform its key roles in fibrin clot formation, platelet aggregation, and wound healing. However, these binding interactions can also contribute to pathophysiologic processes, including inflammation and thrombosis. This review summarizes the latest findings on the role of the fibrinogen gamma chain in these processes, and illustrates the potential for therapeutic intervention. Novel gamma chain epitopes that bind platelet integrin alpha IIbbeta3 and leukocyte integrin alphaMbeta2 have been characterized, leading to the revision of former dogma regarding the processes of platelet aggregation, clot retraction, inflammation, and thrombosis. A series of studies has shown that the gamma chain serves as a depot for fibroblast growth factor-2 (FGF-2), which is likely to play an important role in wound healing. Inhibition of gamma chain function with the monoclonal antibody 7E9 has been shown to interfere with multiple fibrinogen activities, including factor XIIIa crosslinking, platelet adhesion, and platelet-mediated clot retraction. The role of the enigmatic variant fibrinogen gamma chain has also become clearer. Studies have shown that gamma chain binding to thrombin and factor XIII results in clots that are mechanically stiffer and resistant to fibrinolysis, which may explain the association between gammaA/gamma' fibrinogen levels and cardiovascular disease. The identification of new interactions with gamma chains has revealed novel targets for the treatment of inflammation and thrombosis. In addition, several exciting studies have shown new functions for the variant gamma chain that may contribute to cardiovascular disease.

Resistance of a gamma/gamma prime - delta directionally solidified eutectic alloy to recrystallization

NASA Technical Reports Server (NTRS)

Tewari, S. N.; Scheuermann, C. M.; Andrews, C. W.

1975-01-01

The lamellar directionally solidified nickel-base eutectic alloy gamma/gamma prime-delta has potential as an advanced turbine blade material. The microstructural stability of this alloy was investigated. Specimens were plastically deformed by uniform compression or Brinell indentation, then annealed between 705 and 1120 C. Microstructural changes observed after annealing included gamma prime coarsening, pinch-off and spheroidization of delta lamellae, and the appearance of an unidentified blocky phase in surface layers. All but the first of these was localized in severely deformed regions, suggesting that microstructural instability is not a serious problem in the use of this alloy.

Gamma-ray astronomy: From Fermi up to the HAWC high-energy {gamma}-ray observatory in Sierra Negra

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

Carraminana, Alberto; Collaboration: HAWC Collaboration

Gamma-rays represent the most energetic electromagnetic window for the study of the Universe. They are studied both from space at MeV and GeV energies, with instruments like the Fermi{gamma}-ray Space Telescope, and at TeV energies with ground based instruments profiting of particle cascades in the atmosphere and of the Cerenkov radiation of charged particles in the air or in water. The Milagro gamma-ray observatory represented the first instrument to successfully implement the water Cerenkov technique for {gamma}-ray astronomy, opening the ground for the more sensitive HAWC {gamma}-ray observatory, currently under development in the Sierra Negra site and already providing earlymore » science results.« less

Joining of Gamma Titanium Aluminides

DTIC Science & Technology

2002-09-01

AFRL-ML-WP-TR-2003-4036 JOINING OF GAMMA TITANIUM ALUMINIDES LTC William A. Baeslack, III Metals Branch (AFRL/MLLM) Metals, Ceramics, and...GAMMA TITANIUM ALUMINIDES 5c. PROGRAM ELEMENT NUMBER 62102F 5d. PROJECT NUMBER MO2R 5e. TASK NUMBER 10 6. AUTHOR(S) LTC William A...comparatively discusses the results of research and development performed on the joining of gamma titanium aluminides during the past two decades. Although

Gamma-Ray Astronomy Technology Needs

NASA Technical Reports Server (NTRS)

Gehrels, N.; Cannizzo, J. K.

2012-01-01

In recent decades gamma-ray observations have become a valuable tool for studying the universe. Progress made in diverse 8re1lS such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complimented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space y-ray missions and discussion technology needs for- the next generation of space gamma-ray instruments.

Human γ-Glutamyl Transpeptidase 1: STRUCTURES OF THE FREE ENZYME, INHIBITOR-BOUND TETRAHEDRAL TRANSITION STATES, AND GLUTAMATE-BOUND ENZYME REVEAL NOVEL MOVEMENT WITHIN THE ACTIVE SITE DURING CATALYSIS.

PubMed

Terzyan, Simon S; Burgett, Anthony W G; Heroux, Annie; Smith, Clyde A; Mooers, Blaine H M; Hanigan, Marie H

2015-07-10

γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within the active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. These data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Prospects for future very high-energy gamma-ray sky survey: Impact of secondary gamma rays

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

Inoue, Yoshiyuki; Kalashev, Oleg E.; Kusenko, Alexander

2014-02-01

Very high-energy gamma-ray measurements of distant blazars can be well explained by secondary gamma rays emitted by cascades induced by ultra-high-energy cosmic rays. The secondary gamma rays will enable one to detect a large number of blazars with future ground based gamma-ray telescopes such as Cherenkov Telescope Array (CTA). We show that the secondary emission process will allow CTA to detect 100, 130, 150, 87, and 8 blazars above 30 GeV, 100 GeV, 300 GeV, 1 TeV, and 10 TeV, respectively, up to z~8 assuming the intergalactic magnetic field (IGMF) strength B=10-17 G and an unbiased all sky survey withmore » 0.5 h exposure at each field of view, where total observing time is ~540 h. These numbers will be 79, 96, 110, 63, and 6 up to z~5 in the case of B=10-15 G. This large statistics of sources will be a clear evidence of the secondary gamma-ray scenarios and a new key to studying the IGMF statistically. We also find that a wider and shallower survey is favored to detect more and higher redshift sources even if we take into account secondary gamma rays.« less

The control and data acquisition structure for the GAMMA-400 space gamma-telescope

NASA Astrophysics Data System (ADS)

Arkhangelskiy, Andrey

2016-07-01

The GAMMA-400 space project is intended for precision investigation of the cosmic gamma-emission in the energy band from keV region up to several TeV, electrons and positrons fluxes from ˜~1~GeV up to ˜~10~TeV and high energy cosmic-ray nuclei fluxes. A description of the control and data acquisition structure for gamma-telescope involved in the GAMMA 400 space project is given. The technical capabilities of all specialized equipment providing the functioning of the scientific instrumentation and satellite support systems are unified in a single structure. Control of the scientific instruments is maintained using one-time pulse radio commands and program commands transmitted via onboard control system and scientific data acquisition system. Up to 100~GByte of data per day can be transferred to the ground segment of the project. The correctness of the proposed and implemented structure, engineering solutions and electronic elemental base selection has been verified experimentally with the scientific complex prototype in the laboratory conditions.

Gamma-ray Output Spectra from 239 Pu Fission

DOE PAGES

Ullmann, John

2015-05-25

The gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. We found that a dependence of the gamma-raymore » spectrum on the gamma-ray multplicity was also observed. Finally, global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.« less

Gamma-Ray Pulsar Candidates for GLAST

NASA Technical Reports Server (NTRS)

Thompson, D. J.

2008-01-01

The Gamma-ray Large Area Space Telescope (GLAST) will be launched this year, and its Large Area Telescope (LAT) is expected to discover scores to hundreds of gamma-ray pulsars. This poster discusses which of the over 1700 known pulsars, mostly visible only at radio frequencies, are likely to emit greater than 100 MeV gamma rays with intensities detectable by the LAT. The main figure of merit used to select gamma-ray pulsar candidates is sqrt(E-dot)/d2, where E-dot is the energy loss due to rotational spin-down, and d is the distance to the pulsar. The figure of merit incorporates spin-down flux at earth (proportional to E-dot/d2) times efficiency, assumed proportional to l/sqrt(E-dot). A few individual objects are cited to illustrate the issues. Since large E-dot pulsars also tend to have large timing noise and occasional glitches, their ephemerides can become inaccurate in weeks to months. To detect and study the gamma-ray emission the photons must be accurately tagged with the pulse phase. With hours to days between gamma-ray photon arrival times from a pulsar and months to years of LAT exposure needed for good detections, GLAST will rely on radio and X-ray timing measurements throughout the continuous gamma-ray observations. The poster will describe efforts to coordinate pulsar timing of the candidate gamma-ray pulsars.

Gamma-Ray Pulsar Candidates for GLAST

NASA Technical Reports Server (NTRS)

Thompson, David J.; Smith, D. A.; Dumora, D.; Guillemot, L.; Parent, D.; Reposeur, T.; Grove, E.; Romani, R. W.; Thorsett, S. E.

2007-01-01

The Gamma-ray Large Area Space Telescope (GLAST) will be launched less than a year from now, and its Large Area Telescope (LAT) is expected to discover scores to hundreds of gamma-ray pulsars. This poster discusses which of the over 1700 known pulsars, mostly visible only at radio Erequencies, are likely to emit greater than l00 MeV gamma rays with intensities detectable by the LAT. The main figure of merit used to select gamma-ray pulsar candidates is sqrt(E-dot)/d^2, where E-dot is the energy loss due to rotational spindown, and d is the distance to the pulsar. The figure of merit incorporates spin-down flux at earth (proportional to E-dot/d^2) times efficiency, assumed proportional to 1/sqrt(E-dot). A few individual objects are cited to illustrate the issues. Since large E-dot pulsars also tend to have large timing noise and occasional glitches, their ephemerides can become inaccurate in weeks to months. To detect and study the gamma-ray emission the photons must be accurately tagged with the pulse phase. With hours to days between gamma-ray photon arrival times from a pulsar and months to years of LAT exposure needed for good detections, GLAST will need timing measurements throughout the continuous gamma-ray observations. The poster will describe efforts to coordinate pulsar timing of the candidate gamma-ray pulsars.

The structure, logic of operation and distinctive features of the system of triggers and counting signals formation for gamma-telescope GAMMA-400

NASA Astrophysics Data System (ADS)

Topchiev, N. P.; Galper, A. M.; Arkhangelskiy, A. I.; Arkhangelskaja, I. V.; Kheymits, M. D.; Suchkov, S. I.; Yurkin, Y. T.

2017-01-01

Scientific project GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) relates to the new generation of space observatories intended to perform an indirect search for signatures of dark matter in the cosmic-ray fluxes, measurements of characteristics of diffuse gamma-ray emission and gamma-rays from the Sun during periods of solar activity, gamma-ray bursts, extended and point gamma-ray sources, electron/positron and cosmic-ray nuclei fluxes up to TeV energy region by means of the GAMMA-400 gamma-ray telescope represents the core of the scientific complex. The system of triggers and counting signals formation of the GAMMA-400 gamma-ray telescope constitutes the pipelined processor structure which collects data from the gamma-ray telescope subsystems and produces summary information used in forming the trigger decision for each event. The system design is based on the use of state-of-the-art reconfigurable logic devices and fast data links. The basic structure, logic of operation and distinctive features of the system are presented.

Quantification of 235U and 238U activity concentrations for undeclared nuclear materials by a digital gamma-gamma coincidence spectroscopy.

PubMed

Zhang, Weihua; Yi, Jing; Mekarski, Pawel; Ungar, Kurt; Hauck, Barry; Kramer, Gary H

2011-06-01

The purpose of this study is to investigate the possibility of verifying depleted uranium (DU), natural uranium (NU), low enriched uranium (LEU) and high enriched uranium (HEU) by a developed digital gamma-gamma coincidence spectroscopy. The spectroscopy consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results demonstrate that the spectroscopy provides an effective method of (235)U and (238)U quantification based on the count rate of their gamma-gamma coincidence counting signatures. The main advantages of this approach over the conventional gamma spectrometry include the facts of low background continuum near coincident signatures of (235)U and (238)U, less interference from other radionuclides by the gamma-gamma coincidence counting, and region-of-interest (ROI) imagine analysis for uranium enrichment determination. Compared to conventional gamma spectrometry, the method offers additional advantage of requiring minimal calibrations for (235)U and (238)U quantification at different sample geometries. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

A link between prompt optical and prompt gamma-ray emission in gamma-ray bursts.

PubMed

Vestrand, W T; Wozniak, P R; Wren, J A; Fenimore, E E; Sakamoto, T; White, R R; Casperson, D; Davis, H; Evans, S; Galassi, M; McGowan, K E; Schier, J A; Asa, J W; Barthelmy, S D; Cummings, J R; Gehrels, N; Hullinger, D; Krimm, H A; Markwardt, C B; McLean, K; Palmer, D; Parsons, A; Tueller, J

2005-05-12

The prompt optical emission that arrives with the gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions with the surroundings. Until now, only GRB 990123 had been detected at optical wavelengths during the burst phase. Its prompt optical emission was variable and uncorrelated with the prompt gamma-ray emission, suggesting that the optical emission was generated by a reverse shock arising from the ejecta's collision with surrounding material. Here we report prompt optical emission from GRB 041219a. It is variable and correlated with the prompt gamma-rays, indicating a common origin for the optical light and the gamma-rays. Within the context of the standard fireball model of GRBs, we attribute this new optical component to internal shocks driven into the burst ejecta by variations of the inner engine. The correlated optical emission is a direct probe of the jet isolated from the medium. The timing of the uncorrelated optical emission is strongly dependent on the nature of the medium.

The solar gamma ray and neutron capabilities of COMPTEL on the Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Ryan, James M.; Lockwood, John A.

1989-01-01

The imaging Compton telescope COMPTEL on the Gamma Ray Observatory (GRO) has unusual spectroscopic capabilities for measuring solar gamma-ray and neutron emission. The launch of the GRO is scheduled for June 1990 near the peak of the sunspot cycle. With a 30 to 40 percent probability for the Sun being in the COMPTEL field-of-view during the sunlit part of an orbit, a large number of flares will be observed above the 800 keV gamma-ray threshold of the telescope. The telescope energy range extends to 30 MeV with high time resolution burst spectra available from 0.1 to 10 MeV. Strong Compton tail suppression of instrumental gamma-ray interactions will facilitate improved spectral analysis of solar flare emissions. In addition, the high signal to noise ratio for neutron detection and measurement will provide new neutron spectroscopic capabilities. Specifically, a flare similar to that of 3 June 1982 will provide spectroscopic data on greater than 1500 individual neutrons, enough to construct an unambiguous spectrum in the energy range of 20 to 200 MeV. Details of the instrument and its response to solar gamma-rays and neutrons will be presented.

The Mystery of Gamma-Ray Bursts

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2004-01-01

Gamma-ray bursts remain one of the greatest mysteries in astrophysics. Observations of gamma-ray bursts made by the BATSE experiment on the Compton Gamma-Ray Observatory will be described. Most workers in the field now believe that they originate from cosmological distances. This view has been reinforced by observations this year of several optical afterglow counterparts to gamma-ray bursts. A summary of these recent discoveries will be presented, along with their implications for models of the burst emission mechanism and the energy source of the bursts.

Quality assurance for gamma knives

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

Jones, E.D.; Banks, W.W.; Fischer, L.E.

1995-09-01

This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys,more » interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.« less

Regulation of PPAR{gamma} function by TNF-{alpha}

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

Ye Jianping

2008-09-26

The nuclear receptor PPAR{gamma} is a lipid sensor that regulates lipid metabolism through gene transcription. Inhibition of PPAR{gamma} activity by TNF-{alpha} is involved in pathogenesis of insulin resistance, atherosclerosis, inflammation, and cancer cachexia. PPAR{gamma} activity is regulated by TNF-{alpha} at pre-translational and post-translational levels. Activation of serine kinases including IKK, ERK, JNK, and p38 may be involved in the TNF-regulation of PPAR{gamma}. Of the four kinases, IKK is a dominant signaling molecule in the TNF-regulation of PPAR{gamma}. IKK acts through at least two mechanisms: inhibition of PPAR{gamma} expression and activation of PPAR{gamma} corepressor. In this review article, literature is reviewedmore » with a focus on the mechanisms of PPAR{gamma} inhibition by TNF-{alpha}.« less

Studying the High Energy Gamma Ray Sky with Gamma Ray Large Area Space Telescope (GLAST)

NASA Technical Reports Server (NTRS)

Kamae, T.; Ohsugi, T.; Thompson, D. J.; Watanabe, K.

1998-01-01

Building on the success of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the Gamma Ray Large Area Space Telescope (GLAST) will make a major step in the study of such subjects as blazars, gamma Ray bursts, the search for dark matter, supernova remnants, pulsars, diffuse radiation, and unidentified high energy sources. The instrument will be built on new and mature detector technologies such as silicon strip detectors, low-power low-noise LSI, and a multilevel data acquisition system. GLAST is in the research and development phase, and one full tower (of 25 total) is now being built in collaborating institutes. The prototype tower will be tested thoroughly at Stanford Linear Accelerator Center (SLAC) in the fall of 1999.

Ideal cardiovascular health predicts lower risk of abnormal liver enzymes levels in the Chilean National Health Survey (2009–2010)

PubMed Central

Hackney, Anthony C.

2017-01-01

High levels of gamma glutamyltransferase (gamma-GT) and alanine aminotransferase (ALT), as well as fatty liver index (FLI) has been associated with higher cardiovascular disease risk factors in adults. The aim of this study was to examine the relationship between gamma-GT, ALT, and fatty liver index FLI levels across a gradient number of ideal cardiovascular health metrics in a representative sample of adults from the Chilean National Health Survey 2009–2010. Data from 1,023 men and 1,449 women (≥ 15 years) from the Chilean Health Survey 2009–2010 were analyzed. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet adherence) and three factors (total cholesterol, blood pressure and fasting glucose). Adults were grouped into three categories according to their number of ideal cardiovascular health metrics: ideal (5–7 metrics), intermediate (3–4 metrics), and poor (0–2 metrics). Blood levels of gamma-GT and ALT were measured and the FLI was calculated. A higher number of ideal cardiovascular health index metric was associated with lower gamma-GT, ALT and FLI (p from trend analysis <0.001). Also, adults meeting at least 3–4 metrics were predicted less likely to have prevalence of abnormal levels of gamma-GT and FLI (p<0.001) compared to adults who met only 0–2 metrics. These findings reinforce the usefulness of the ideal cardiovascular health metrics proposed by the American Heart Association as a tool to identify target subjects and promote cardiovascular health in South-American adults. PMID:29049384

The Gamma-Ray Imager GRI

NASA Astrophysics Data System (ADS)

Wunderer, Cornelia B.; GRI Collaboration

2008-03-01

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are major science themes that are addressed in the gamma-ray regime. ESA's INTEGRAL observatory currently provides the astronomical community with a unique tool to investigate the sky up to MeV energies and hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes have been discovered. NASA's GLAST mission will similarly take the next step in surveying the high-energy ( GeV) sky, and NuSTAR will pioneer focusing observations at hard X-ray energies (to 80 keV). There will be clearly a growing need to perform deeper, more focused investigations of gamma-ray sources in the 100-keV to MeV regime. Recent technological advances in the domain of gamma-ray focusing using Laue diffraction and multilayer-coated mirror techniques have paved the way towards a gamma-ray mission, providing major improvements compared to past missions regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow the study of particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

Gamma Ray Bursts-Afterglows and Counterparts

NASA Technical Reports Server (NTRS)

Fishman, Gerald J

1998-01-01

Several breakthrough discoveries were made last year of x-ray, optical and radio afterglows and counterparts to gamma-ray bursts, and a redshift has been associated with at least one of these. These discoveries were made possible by the fast, accurate gamma-ray burst locations of the BeppoSAX satellite. It is now generally believed that the burst sources are at cosmological distances and that they represent the most powerful explosions in the Universe. These observations also open new possibilities for the study of early star formation, the physics of extreme conditions and perhaps even cosmology. This session will concentrate on recent x-ray, optical and radio afterglow observations of gamma-ray bursts, associated redshift measurements, and counterpart observations. Several review and theory talks will also be presented, along with a summary of the astrophysical implications of the observations. There will be additional poster contributions on observations of gamma-ray burst source locations at wavelengths other than gamma rays. Posters are also solicited that describe new observational capabilities for rapid follow-up observations of gamma-ray bursts.

Fermi Gamma-Ray Space Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie E.; Michelson, Peter F.; Paclesas, William S.; Ritz, Steven

2012-01-01

The Fermi Gamma-ray Space Telescope, launched in June 2008, is an observatory designed to survey the high-energy gamma-ray sky. The primary instrument, the Large Area Telescope (LAT), provides observations from 20 MeV to greater than 300 GeV. A second instrument, the Gamma-ray Burst Monitor (GBM), provides observations of transients from less than 10 keV to 40 MeV. We describe the design and performance of the instruments and their subsystems, the spacecraft and the ground system.

Haematinic Deficiency and Macrocytosis in Middle-Aged and Older Adults

PubMed Central

Harrington, Janas; Cadogan, Sharon; Honari, Bahman; Perera, Kanthi; Fitzgerald, Anthony P.; Perry, Ivan J.; Cahill, Mary R.

2013-01-01

Objective To assess the prevalence and determinants of haematinic deficiency (lack of B12 folate or iron) and macrocytosis in blood from a national population-based study of middle-aged and older adults. Methods A cross-sectional study involving 1,207 adults aged ≥45 years, recruited from a sub-study of the Irish National Survey of Lifestyle Attitudes and Nutrition (SLÁN 2007). Participants completed a health and lifestyle questionnaire and a standard food frequency questionnaire. Non-fasting blood samples were obtained for measurement of full blood count and expert morphological assessment, serum ferritin, soluble transferrin receptor assay (sTfR), B12, folate and coeliac antibodies. Blood samples were also assayed for thyroid function (T4, TSH), liver function, aminotransferase (AST) and gamma-glutamyl transferase (GGT). Results The overall prevalence (95% C.I.) of anaemia (Hb <13.5g/dl men and 11.3 g/dl women) was 4.6% (2.9%–6.4%) in men and 1.0% (0.2%–1.9%) in women. Iron deficiency (ferritin <17ng/ml men and <11ng/ml in women) was detected in 6.3% of participants (3.7% in males and 8.7% in females, p<0.001). Based on both low ferritin and raised sTfR (>21nmol/ml) only 2.3% were iron-deficient. 3.0% and 2.7% were found to have low levels of serum folate (<2.3ng/ml) and serum B12 (<120ng/l) respectively. Clinically significant macrocytosis (MCV>99fl) was detected in 8.4% of subjects. Strong, significant and independent associations with macrocytosis were observed for lower social status, current smoking status, moderate to heavy alcohol intake, elevated GGT levels, deficiency of folate and vitamin B12, hypothyroidism and coeliac disease. The population attributable fraction (PAF) for macrocytosis associated with elevated GGT (25.0%) and smoking (24.6%) was higher than for excess alcohol intake (6.3%), folate deficiency (10.5%) or vitamin B12 (3.4%). Conclusions Haematinic deficiency and macrocytosis are common in middle-aged/older adults in Ireland

Cortical volume and sex influence visual gamma.

PubMed

van Pelt, Stan; Shumskaya, Elena; Fries, Pascal

2018-06-05

Visually induced gamma-band activity (GBA) has been implicated in several central cognitive functions, in particular perceptual binding, the feedforward routing of attended stimulus information and memory encoding. Several studies have documented that the strength and frequency of GBA are influenced by both subject-intrinsic factors like age, and subject-extrinsic factors such as stimulus contrast. Here, we investigated the relative contributions of previously tested factors, additional factors, and their interactions, in a cohort of 158 subjects recorded with magnetoencephalography (MEG). In agreement with previous studies, we found that gamma strength and gamma peak frequency increase with stimulus contrast and stimulus velocity. Also in confirmation of previous findings, we report that gamma peak frequency declines with subject age. In addition, we found that gamma peak frequency is higher for subjects with thicker occipital cortex, but lower for larger occipital cortices. Also, gamma peak frequency is higher in female than male subjects. Extrinsic factors (stimulus contrast and velocity) and intrinsic factors (age, cortical thickness and sex) together explained 21% of the variance in gamma peak frequency and 20% of the variance in gamma strength. These results can contribute to our understanding of the mechanisms, by which gamma is generated, and the mechanisms, through which it affects the cognitive performance of a given individual subject. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

GRI: the gamma-ray imager mission

NASA Astrophysics Data System (ADS)

Knödlseder, Jürgen

2006-06-01

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are the major science themes that are addressed in the gamma-ray regime. With the INTEGRAL observatory, ESA has provided a unique tool to the astronomical community revealing hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes. While INTEGRAL provides the global overview over the soft gamma-ray sky, there is a growing need to perform deeper, more focused investigations of gamma-ray sources. In soft X-rays a comparable step was taken going from the Einstein and the EXOSAT satellites to the Chandra and XMM/Newton observatories. Technological advances in the past years in the domain of gamma-ray focusing using Laue diffraction and multilayer-coated mirror techniques hav paved the way towards a gamma-ray mission, providing major improvements compared to past missions regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow to study particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

Delayed Gamma Measurements in Different Nuclear Research Reactors Bringing Out the Importance of the Delayed Contribution in Gamma Flux Calculations

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

Fourmentel, D.; Radulovic, V.; Barbot, L.

Neutron and gamma flux levels are key parameters in nuclear research reactors. In Material Testing Reactors, such as the future Jules Horowitz Reactor, under construction at the French Alternative Energies and Atomic Energy Commission (CEA Cadarache, France), the expected gamma flux levels are very high (nuclear heating is of the order of 20 W/g at 100 MWth). As gamma rays deposit their energy in the reactor structures and structural materials it is important to take them into account when designing irradiation devices. There are only a few sensors which allow measurements of the nuclear heating ; a recent development atmore » the CEA Cadarache allows measurements of the gamma flux using a miniature ionization chamber (MIC). The measured MIC response is often compared with calculation using modern Monte Carlo (MC) neutron and photon transport codes, such as TRIPOLI-4 and MCNP6. In these calculations only the production of prompt gamma rays in the reactor is usually modelled thus neglecting the delayed gamma rays. Hence calculations and measurements are usually in better accordance for the neutron flux than for the gamma flux. In this paper we study the contribution of delayed gamma rays to the total MIC signal in order to estimate the systematic error in gamma flux MC calculations. In order to experimentally determine the delayed gamma flux contributions to the MIC response, we performed gamma flux measurements with CEA developed MIC at three different research reactors: the OSIRIS reactor (MTR - 70 MWth at CEA Saclay, France), the TRIGA MARK II reactor (TRIGA - 250 kWth at the Jozef Stefan Institute, Slovenia) and the MARIA reactor (MTR - 30 MWth at the National Center for Nuclear Research, Poland). In order to experimentally assess the delayed gamma flux contribution to the total gamma flux, several reactor shut down (scram) experiments were performed specifically for the purpose of the measurements. Results show that on average about 30 % of the MIC signal is

New Fermi-LAT event reconstruction reveals more high-energy gamma rays from gamma-ray bursts

DOE PAGES

Atwood, W. B.; Baldini, L.; Bregeon, J.; ...

2013-08-19

Here, based on the experience gained during the four and a half years of the mission, the Fermi-LAT Collaboration has undertaken a comprehensive revision of the event-level analysis going under the name of Pass 8. Although it is not yet finalized, we can test the improvements in the new event reconstruction with the special case of the prompt phase of bright gamma-ray bursts (GRBs), where the signal-to-noise ratio is large enough that loose selection cuts are sufficient to identify gamma rays associated with the source. Using the new event reconstruction, we have re-analyzed 10 GRBs previously detected by the Largemore » Area Telescope (LAT) for which an X-ray/optical follow-up was possible and found four new gamma rays with energies greater than 10 GeV in addition to the seven previously known. Among these four is a 27.4 GeV gamma ray from GRB 080916C, which has a redshift of 4.35, thus making it the gamma ray with the highest intrinsic energy (~147 GeV) detected from a GRB. We present here the salient aspects of the new event reconstruction and discuss the scientific implications of these new high-energy gamma rays, such as constraining extragalactic background light models, Lorentz invariance violation tests, the prompt emission mechanism, and the bulk Lorentz factor of the emitting region.« less

Process gg{yields}h{sub 0}{yields}{gamma}{gamma} in the Lee-Wick standard model

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

Krauss, F.; Underwood, T. E. J.; Zwicky, R.

2008-01-01

The process gg{yields}h{sub 0}{yields}{gamma}{gamma} is studied in the Lee-Wick extension of the standard model (LWSM) proposed by Grinstein, O'Connell, and Wise. In this model, negative norm partners for each SM field are introduced with the aim to cancel quadratic divergences in the Higgs mass. All sectors of the model relevant to gg{yields}h{sub 0}{yields}{gamma}{gamma} are diagonalized and results are commented on from the perspective of both the Lee-Wick and higher-derivative formalisms. Deviations from the SM rate for gg{yields}h{sub 0} are found to be of the order of 15%-5% for Lee-Wick masses in the range 500-1000 GeV. Effects on the rate formore » h{sub 0}{yields}{gamma}{gamma} are smaller, of the order of 5%-1% for Lee-Wick masses in the same range. These comparatively small changes may well provide a means of distinguishing the LWSM from other models such as universal extra dimensions where same-spin partners to standard model fields also appear. Corrections to determinations of Cabibbo-Kobayashi-Maskawa (CKM) elements |V{sub t(b,s,d)}| are also considered and are shown to be positive, allowing the possibility of measuring a CKM element larger than unity, a characteristic signature of the ghostlike nature of the Lee-Wick fields.« less

γ-glutamyl transpeptidase 1 specifically suppresses green-light avoidance via GABAA receptors in Drosophila.

PubMed

Liu, Jiangqu; Gong, Zhefeng; Liu, Li

2014-08-01

Drosophila larvae innately show light avoidance behavior. Compared with robust blue-light avoidance, larvae exhibit relatively weaker green-light responses. In our previous screening for genes involved in larval light avoidance, compared with control w(1118) larvae, larvae with γ-glutamyl transpeptidase 1 (Ggt-1) knockdown or Ggt-1 mutation were found to exhibit higher percentage of green-light avoidance which was mediated by Rhodopsin6 (Rh6) photoreceptors. However, their responses to blue light did not change significantly. By adjusting the expression level of Ggt-1 in different tissues, we found that Ggt-1 in malpighian tubules was both necessary and sufficient for green-light avoidance. Our results showed that glutamate levels were lower in Ggt-1 null mutants compared with controls. Feeding Ggt-1 null mutants glutamate can normalize green-light avoidance, indicating that high glutamate concentrations suppressed larval green-light avoidance. However, rather than directly, glutamate affected green-light avoidance indirectly through GABA, the level of which was also lower in Ggt-1 mutants compared with controls. Mutants in glutamate decarboxylase 1, which encodes GABA synthase, and knockdown lines of the GABAA receptor, both exhibit elevated levels of green-light avoidance. Thus, our results elucidate the neurobiological mechanisms mediating green-light avoidance, which was inhibited in wild-type larvae. © 2014 International Society for Neurochemistry.

Ionizing radiation potentiates the induction of nitric oxide synthase by interferon-gamma (Ifn-gamma) or Ifn-gamma and lipopolysaccharide in bnl cl.2 murine embryonic liver cells: role of hydrogen peroxide.

PubMed

Yoo, J C; Pae, H O; Choi, B M; Kim, W I; Kim, J D; Kim, Y M; Chung, H T

2000-02-01

The effects of ionizing irradiation on the nitric oxide (NO) production in murine embryonic liver cell line, BNL CL.2 cells, were investigated. Various doses (5-40 Gy) of radiation made BNL CL.2 cells responsive to interferon-gamma alone for the production of NO in a dose-dependent manner. Small amounts of lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) synergized with IFN-gamma in the production of NO from irradiated BNL CL.2 cells, even though LPS or TNF-alpha alone did not induce NO production from the same cells. Immunoblots showed parallel induction of inducible nitric oxide synthase (iNOS). NO production in irradiated BNL CL.2 cells by IFN-gamma or IFN-gamma plus LPS was decreased by the addition of catalase, suggesting that H(2)O(2) produced by ionizing irradiation primed the cells to trigger NO production in response to IFN-gamma or IFN-gamma plus LPS. Furthermore, the treatment of nongamma-irradiated BNL CL.2 cells with H(2)O(2) made the cells responsive to IFN-gamma or IFN-gamma plus LPS for the production of NO. This study shows that ionizing irradiation has the ability to induce iNOS gene expression in responsive to IFN-gamma via the formation of H(2)O(2) in BNL CL.2 murine embryonic liver cells.

Simultaneous optical/gamma-ray observations of GRBs

NASA Technical Reports Server (NTRS)

Greiner, J.; Wenzel, W.; Hudec, R.; Moskalenko, E. I.; Metlov, V.; Chernych, N. S.; Getman, V. S.; Ziener, Rainer; Birkle, K.; Bade, N.

1994-01-01

Details on the project to search for serendipitous time correlated optical photographic observations of Gamma Ray Bursters (GRB's) are presented. The ongoing photographic observations at nine observatories are used to look for plates which were exposed simultaneously with a gamma ray burst detected by the gamma ray instrument team (BATSE) and contain the burst position. The results for the first two years of the gamma ray instrument team operation are presented.

Regulation of the steady state level of Fc gamma RI mRNA by IFN-gamma and dexamethasone in human monocytes, neutrophils, and U-937 cells.

PubMed

Pan, L Y; Mendel, D B; Zurlo, J; Guyre, P M

1990-07-01

The high affinity IgG FcR Fc gamma RI, CD64, plays important roles in the immune response. Fc gamma RI is predominantly expressed on monocytes and macrophages, and barely detectable on neutrophils. rIFN-gamma markedly increases the expression of Fc gamma RI on neutrophils, monocytes, macrophages and myeloid cell lines such as U-937, HL-60, and THP-1. Glucocorticoids inhibit the augmentation of Fc gamma RI expression by rIFN-gamma on neutrophils and myeloid cell lines, but enhance the augmentation of Fc gamma RI expression by rIFN-gamma on monocytes. In this study, we examined the effect of rIFN-gamma and dexamethasone (Dex) on the steady state level of Fc gamma RI mRNA in U-937 cells, neutrophils, and monocytes by hybridizing total RNA with the Fc gamma RI cDNA probe, p135. We found that the amount of Fc gamma RI mRNA increased within 1 h of treatment with rIFN-gamma in all three cell types. This initial induction of Fc gamma RI mRNA by rIFN-gamma was completely blocked by an inhibitor of RNA synthesis, actinomycin D, suggesting that the rIFN-gamma-mediated induction of Fc gamma RI mRNA is dependent on gene transcription. Dex, used in combination with rIFN-gamma, partially blocked the induction of Fc gamma RI mRNA by rIFN-gamma in U-937 cells and neutrophils, but caused a synergistic increase in Fc gamma RI mRNA levels in monocytes. The inhibitory effect of Dex on the steady state level of Fc gamma RI mRNA in U-937 cells was blocked by an inhibitor of protein synthesis, cycloheximide, suggesting that Dex-induced proteins were involved in the regulation of Fc gamma RI expression. This study indicates that the regulation of Fc gamma RI expression on U-937 cells, neutrophils, and monocytes by rIFN-gamma and Dex occurs, at least in part, at the mRNA level. rIFN-gamma increases the steady state level of Fc gamma RI mRNA through a common pathway among U-937 cells, neutrophils, and monocytes, whereas the effect of Dex on rIFN-gamma-induced Fc gamma RI mRNA is cell

TEMPORAL EVOLUTION OF SUB-NANOMETER COMPOSITIONAL PROFILES ACROSS THE GAMMA/GAMMA' INTERFACE IN A MODEL Ni-Al-Cr SUPERALLOY

NASA Technical Reports Server (NTRS)

Sudbrack, Chantal K.; Noebe, Ronald D.; Seidman, David N.

2005-01-01

Early-stage phase separation in a Ni-5.2 Al-14.2 Cr at.% superalloy, isothermally decomposing at 873 K, is investigated with atom-probe tomography. Sub-nanometer scale compositional profiles across the gamma/gamma'(L12) interfaces demonstrate that both the gamma-matrix and the gamma'-precipitate compositions evolve with time. Observed chemical gradients of Al depletion and Cr enrichment adjacent to the gamma'-precipitates are transient, consistent with well-established model predictions for diffusion-limited growth, and mark the first detailed observation of this phenomenon. Furthermore, it is shown that Cr atoms are kinetically trapped in the growing precipitates.

Interferon-gamma (INF-gamma) release test can detect cutaneous adverse effects to statins.

PubMed

Goldberg, Ilan; Isman, Gila; Shirazi, Idit; Brenner, Sarah

2009-12-01

An increasing number of cutaneous adverse effects are being reported as use of statins becomes more widespread. A study was undertaken to establish the relationship between statin and a cutaneous reaction by the in vitro interferon-gamma (INF-gamma) release test. The lymphocytes of 20 patients with suspected drug-induced skin reaction were incubated with and without the drug. The level of INF-gamma from the supernatant was measured by enzyme-linked immunosorbent assay (ELISA), and the increase calculated. Response was positive in 27 (21.43%) of the 126 drugs. Statin was the only drug with a positive response in 80% of those cases. Nine of 20 patients (45.0%) had complete resolution after discontinuation of the drug; 6 (30.0%) who replaced one drug by another statin had partial or no resolution; and 5 (20.0%) had no resolution despite cessation of statins of all kinds. A positive INF-gamma release test was found in patients who developed skin reactions while taking statins; the test's reliability was strengthened by prompt improvement following elimination of the suspected drug in the majority of patients.

DSC studies on gamma irradiated poly(vinylidene fluoride) applied to high gamma dose dosimetry

NASA Astrophysics Data System (ADS)

Batista, Adriana S. M.; Faria, Luiz O.

2017-11-01

Poly(vinylidene fluoride) homopolymer (PVDF) was investigated for use on high gamma dose dosimetry. Samples were irradiated with gamma doses ranging from 100 kGy to 3000 kGy. Differential scanning calorimetry (DSC) was used to construct an unambiguous relationship between the melting transition latent heat (LM) and the absorbed dose (D). DSC thermograms were taken immediately, 1, 2 and 8 months after the irradiation process revealing that the LMx D relationship presented no change for doses ranging from 100 to 2750 kGy. FTIR and UV-Vis spectroscopy data revealed the radio-induction of C˭O and C˭C bonds. These radio-induced bonds were responsible by the chain stiffening and chain oxidation, respectively. SEM microscopy demonstrates that the spherulitic large crystalline structures present in pristine PVDF are destroyed with doses as low as 100 kGy. The DRX analysis revealed that the main effect of high gamma doses in the crystalline structure of PVDF is to provoke a change from the pristine PVDF α-phase to the γ-phase. Both the ability to detect gamma doses in a large dose range and the low fading features make PVDF homopolymers good candidates to be investigated as high gamma dose dosimeters.

Human EEG gamma oscillations in neuropsychiatric disorders.

PubMed

Herrmann, C S; Demiralp, T

2005-12-01

Due to their small amplitude, the importance of high-frequency EEG oscillations with respect to cognitive functions and disorders is often underestimated as compared to slower oscillations. This article reviews the literature on the alterations of gamma oscillations (about 30-80 Hz) during the course of neuropsychiatric disorders and relates them to a model for the functional role of these oscillations for memory matching. The synchronous firing of neurons in the gamma-band has been proposed to bind multiple features of an object, which are coded in a distributed manner in the brain, and is modulated by cognitive processes such as attention and memory. In certain neuropsychiatric disorders the gamma activity shows significant changes. In schizophrenic patients, negative symptoms correlate with a decrease of gamma responses, whereas a significant increase in gamma amplitudes is observed during positive symptoms such as hallucinations. A reduction is also observed in Alzheimer's Disease (AD), whereas an increase is found in epileptic patients, probably reflecting both cortical excitation and perceptual distortions such as déjà vu phenomena frequently observed in epilepsy. ADHD patients also exhibit increased gamma amplitudes. A hypothesis of a gamma axis of these disorders mainly based on the significance of gamma oscillations for memory matching is formulated.

Hepatoprotective Effects of Chinese Medicine Herbs Decoction on Liver Cirrhosis in Rats

PubMed Central

Lim, Tong-Hye; Nor-Amdan, Nur-Asyura

2017-01-01

Hepatoprotective and curative activities of aqueous extract of decoction containing 10 Chinese medicinal herbs (HPE-XA-08) were evaluated in Sprague–Dawley albino rats with liver damage induced by thioacetamide (TAA). These activities were assessed by investigating the liver enzymes level and also histopathology investigation. Increases in alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) levels were observed in rats with cirrhotic liver. No significant alterations of the liver enzymes were observed following treatment with HPE-XA-08. Histopathology examination of rats treated with HPE-XA-08 at 250 mg/kg body weight, however, exhibited moderate liver protective effects. Reduced extracellular matrix (ECM) proteins within the hepatocytes were noted in comparison to the cirrhotic liver. The curative effects of HPE-XA-08 were observed with marked decrease in the level of ALP (more than 3x) and level of GGT (more than 2x) in cirrhotic rat treated with 600 mg/kg body weight HPE-XA-08 in comparison to cirrhotic rat treated with just water diluent. Reversion of cirrhotic liver to normal liver condition in rats treated with HPE-XA-08 was observed. Results from the present study suggest that HPE-XA-08 treatment assisted in the protection from liver cirrhosis and improved the recovery of cirrhotic liver. PMID:28280515

Bioaccumulation of methyl parathion and its toxicology in several species of the freshwater community in Ignacio Ramirez dam in Mexico.

PubMed

De La Vega Salazar, M Y; Tabche, L M; García, C M

1997-10-01

Environmental contamination by pesticides, including the presence of chemical residues in aquatic wildlife, is a widespread ecological problem. Methyl parathion (MP), a widely used organophosphorate insecticide, is a potent neurotoxic in both vertebrates and invertebrates. The effect of a subchronic exposure to MP in aquatic organisms was evaluated in a natural ecosystem measuring acetyl cholinesterase (AChE) and gamma glutamil transpeptidase (GGT) activity. Two samples were conducted. Physicochemical characterization was done at each sampling time and organisms were collected. MP and metabolite 4-nitrophenol (4-NP) concentrations were measured in water sediment and organisms. The major differences in physical features between season were an increase of turbidity and salinity and depletion of dissolved oxygen in the rainy season. MP and 4-NP are bioconcentrated in organisms in response to environmental stress. MP concentration was measured in different size/age and reproductive stages separately. A significant concentration in reproductive tissues (plants)/unborn progeny (animals) was always found, and this can affect egg viability. The metabolite 4-NP is bioaccumulated and is toxic because it causes an increase of AChE activity. GGT activity was higher than that in controls. The increase in enzymatic activity provides a detoxification mechanism from chronic sublethal exposure, when hepatic glutation depletion occurs, and may be an indicator of liver damage.

Dietary antioxidant and anti-inflammatory intake modifies the effect of cadmium exposure on markers of systemic inflammation and oxidative stress.

PubMed

Colacino, Justin A; Arthur, Anna E; Ferguson, Kelly K; Rozek, Laura S

2014-05-01

Chronic cadmium exposure may cause disease through induction of systemic oxidative stress and inflammation. Factors that mitigate cadmium toxicity and could serve as interventions in exposed populations have not been well characterized. We used data from the 2003-2010 National Health and Nutrition Examination Survey to quantify diet׳s role in modifying associations between cadmium exposure and oxidative stress and inflammation. We created a composite antioxidant and anti-inflammatory diet score (ADS) by ranking participants by quintile of intake across a panel of 19 nutrients. We identified associations and effect modification between ADS, urinary cadmium, and markers of oxidative stress and inflammation by multiple linear regression. An interquartile range increase in urinary cadmium was associated with a 47.5%, 8.8%, and 3.7% increase in C-reactive protein (CRP), gamma glutamyl transferase (GGT), and alkaline phosphatase (ALP), respectively. An interquartile range increase in ADS was associated with an 7.4%, 3.3%, 5.2%, and 2.5% decrease in CRP, GGT, ALP, and total white blood cell count respectively, and a 3.0% increase in serum bilirubin. ADS significantly attenuated the association between cadmium exposure, CRP and ALP. Dietary interventions may provide a route to reduce the impact of cadmium toxicity on the population level. Copyright © 2014 Elsevier Inc. All rights reserved.

Dietary antioxidant and anti-inflammatory intake modifies the effect of cadmium exposure on markers of systemic inflammation and oxidative stress

PubMed Central

Colacino, Justin A.; Arthur, Anna E.; Ferguson, Kelly K.; Rozek, Laura S.

2014-01-01

Chronic cadmium exposure may cause disease through induction of systemic oxidative stress and inflammation. Factors that mitigate cadmium toxicity and could serve as interventions in exposed populations have not been well characterized. We used data from the 2003–2010 National Health and Nutrition Examination Survey to quantify diet’s role in modifying associations between cadmium exposure and oxidative stress and inflammation. We created a composite antioxidant and anti-inflammatory diet score (ADS) by ranking participants by quintile of intake across a panel of 19 nutrients. We identified associations and effect modification between ADS, urinary cadmium, and markers of oxidative stress and inflammation by multiple linear regression. An interquartile range increase in urinary cadmium was associated with a 47.5%, 8.8%, and 3.7% increase in C-reactive protein (CRP), gamma glutamyl transferase (GGT), and alkaline phosphatase (ALP), respectively. An interquartile range increase in ADS was associated with an 7.4%, 3.3%, 5.2%, and 2.5% decrease in CRP, GGT, ALP, and total white blood cell count respectively, and a 3.0% increase in serum bilirubin. ADS significantly attenuated the association between cadmium exposure, CRP and ALP. Dietary interventions may provide a route to reduce the impact of cadmium toxicity on the population level. PMID:24607659

Biochemical and histological responses of Rattus novergicus (Wistar) infected by Echinostoma paraensei (Trematoda: Echinostomatidae).

PubMed

Garcia, Juberlan S; Hooper, Cleber S; Simões, Raquel O; Dos Santos, Marcos Antônio J; Maldonado, Arnaldo; Pinheiro, Jairo

2011-05-31

Tests were performed to evaluate the biochemical alterations in Rattus norvegicus after infection by the intestinal trematode Echinostoma paraensei. The rodents received 150 metacercariae each, serum samples were collected and the parasite load was quantified weekly until the fifth week of infection. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALKP), gamma-glutamyl transferase (GGT), bilirubin, glucose, total proteins and fractions and hepatic glycogen were determined. All the animals exposed to the metacercariae were infected in the first week and worms were recovered up to the third week after infection. The levels of AST, ALT, GGT, bilirubin and globulin rose in the first and/or second week and declined thereafter to levels near those of the control group. In contrast, the level of total proteins in the plasma fell significantly in the first week while the ALKP activity went down only in the fourth and fifth weeks in relation to the control group. There was no significant difference in the levels of albumin, glycogen and glucose. Infection by E. paraensei in R. norvegicus causes changes in the hepatic function, possibly resulting from the cholestasis produced by the partial obstruction of the bile duct by the helminths. Copyright © 2011 Elsevier B.V. All rights reserved.

Fatigue crack propagation behaviour of unidirectionally solidified gamma/gamma-prime-delta eutectic alloys. [Ni-Nb-Al alloys

NASA Technical Reports Server (NTRS)

Bretz, P. E.; Hertzberg, R. W.

1979-01-01

Fatigue crack propagation studies were carried out on unidirectionally solidified gamma/gamma-prime-delta (Ni-Nb-Al) alloys over an aluminum content range of 1.5-2.5% by weight. The variation of Al content of as-grown alloys did not significantly affect the crack growth behavior of these eutectic composites. The results indicate that the addition of Al to the eutectic dramatically improved the FCP behavior. The gamma/gamma-prime-delta alloy exhibited crack growth rates for a given stress intensity range that are an order of magnitude lower than those for the gamma-delta alloy. It is suggested that this difference in FCP behavior can be explained on the basis of stacking fault energy considerations. Extensive delaminations at the crack tip were also revealed, which contributed to the superior fatigue response. Delamination was predominantly intergranular in nature.

Microstructural changes caused by thermal treatment and their effects on mechanical properties of a gamma/gamma prime - delta eutectic alloy

NASA Technical Reports Server (NTRS)

Tewari, S. N.; Dreshfield, R. L.

1976-01-01

Microstructural changes due to thermal treatments of a directionally solidified gamma/gamma'-delta eutectic alloy were investigated. Aging treatments of 8 to 48 hours and ranging from 750 to 1120 C were given to the alloy in both its as directionally solidified condition and after gamma' solutioning. Aging resulted in gamma' coarsening gamma precipitates in delta, and delta and gamma'' precipitates in delta. The tensile strength was increased about 12 percent at temperatures up to 900 C by a heat treatment. Times to rupture were essentially the same or greater than for as directionally solidified material. Tensile and rupture ductility in the growth direction of the alloy were reduced by the heat treatment.

Combination neutron-gamma ray detector

DOEpatents

Stuart, Travis P.; Tipton, Wilbur J.

1976-10-26

A radiation detection system capable of detecting neutron and gamma events and distinguishing therebetween. The system includes a detector for a photomultiplier which utilizes a combination of two phosphor materials, the first of which is in the form of small glass beads which scintillate primarily in response to neutrons and the second of which is a plastic matrix which scintillates in response to gammas. A combination of pulse shape and pulse height discrimination techniques is utilized to provide an essentially complete separation of the neutron and gamma events.

Gamma ray astrophysics. [emphasizing processes and absorption

NASA Technical Reports Server (NTRS)

Stecker, F. W.

1974-01-01

Gamma ray production processes are reviewed, including Compton scattering, synchrotron radiation, bremsstrahlung interactions, meson decay, nucleon-antinucleon annihilations, and pion production. Gamma ray absorption mechanisms through interactions with radiation and with matter are discussed, along with redshifts and gamma ray fluxes.

Comparison of efficacy of folic acid and silymarin in the management of antiepileptic drug induced liver injury: a randomized clinical trial.

PubMed

Asgarshirazi, Masoumeh; Shariat, Mamak; Sheikh, Mahdi

2017-06-01

Liver injury associated with antiepileptic drugs accounts for a large proportion of drug-induced liver injuries (DILI) in children. Although withdrawal of the causative agent is the only proved treatment for DILI, in some clinical situations it is not possible. Recent studies have reported promising results of using hepatoprotective drugs with antioxidant actions for the management of DILI. This study aimed to evaluate the efficacy of folic acid versus silymarin treatment in relation to decreasing liver enzymes in patients with DILI due to antiepileptic therapy. This randomized, open-label, clinical trial evaluated 55 children with epilepsy who were on antiepileptic treatment and experienced DILI. The children were randomized to receive either silymarin (5 mg/kg per day) or folic acid (1 mg per day) for one month and were followed up for three months. Liver enzymes significantly decreased in both groups. The decrease trend in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were stronger in the folic acid group compared to silymarin group (P=0.04 and P=0.007, respectively). At the end of the study patients in the folic acid group had significantly lower ALT (P=0.04), AST (P=0.02), and gamma-glutamyl transferase (GGT) (P<0.001) levels and also higher percentage of normal ALT (30.7% vs 3.4%, P=0.009) and AST (42.3% vs 0%, P<0.001), and GGT (23.1% vs 0%, P=0.008) values compared to the patients in the silymarin group. No rebound elevations in ALT, AST and GGT levels or adverse reactions were noted in neither of the study groups. Although both treatments were safe and effective in decreasing liver enzymes, folic acid seems to be superior to silymarin in the management of DILI.

Association between hepatic steatosis and serum liver enzyme levels with atrial fibrillation in the general population: The Study of Health in Pomerania (SHIP).

PubMed

Markus, Marcello Ricardo Paulista; Meffert, Peter J; Baumeister, Sebastian Edgar; Lieb, Wolfgang; Siewert, Ulrike; Schipf, Sabine; Koch, Manja; Kors, Jan A; Felix, Stephan Burkhard; Dörr, Marcus; Targher, Giovanni; Völzke, Henry

2016-02-01

Hepatic steatosis (HS) affects up to 35% of adults in the general population. Atrial fibrillation (AF) is the most prevalent sustained arrhythmia and has a substantial impact on healthcare costs. We analyzed cross-sectional associations of HS and serum liver enzyme levels with prevalent AF in a general population sample. We analyzed data from 3090 women and men, aged 20-81 years, from the population-based Study of Health in Pomerania. HS was determined by ultrasonography. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltranspeptidase (GGT) were measured photometrically. AF was determined by automatic electrocardiographic analysis software. The prevalences of HS and AF were 30.3% and 1.49%, respectively. ALT, AST and GGT showed a positive linear association with the risk of prevalent AF, after multivariable adjustment. The adjusted odds ratios for AF per 1-standard deviation increment in log-transformed serum liver enzyme levels were 1.65 (95% confidence interval [CI]: 1.16 to 2.35; p = 0.006) for ALT, 1.47 (95%CI: 1.07 to 2.02; p = 0.017) for AST and 2.17 (95%CI: 1.64 to 2.87; p < 0.001) for GGT. In contrast, ultrasonographic HS was not associated with AF. Our findings indicate that moderately elevated serum liver enzymes, but not sonographic liver hyperechogenicity, were associated with increased AF prevalence in the general adult population. The hepatic release of increased levels of serum liver enzymes might be accompanied by higher levels of pro-inflammatory, pro-coagulant and pro-fibronogenic mediators that might lead to structural and electrical remodeling of the atrium resulting in the development and persistence of AF. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Prospective association of liver function biomarkers with development of hepatobiliary cancers.

PubMed

Stepien, Magdalena; Fedirko, Veronika; Duarte-Salles, Talita; Ferrari, Pietro; Freisling, Heinz; Trepo, Elisabeth; Trichopoulou, Antonia; Bamia, Christina; Weiderpass, Elisabete; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Boutron-Ruault, Marie-Christine; Fagherazzi, Guy; Racine, Antoine; Kühn, Tilman; Kaaks, Rudolf; Aleksandrova, Krasimira; Boeing, Heiner; Lagiou, Pagona; Benetou, Vassiliki; Trichopoulos, Dimitrios; Palli, Domenico; Grioni, Sara; Tumino, Rosario; Naccarati, Alessio; Panico, Salvatore; Bueno-de-Mesquita, H Bas; Peeters, Petra H; Lund, Eiliv; Quirós, J Ramón; Nápoles, Osmel Companioni; Sánchez, María-José; Dorronsoro, Miren; Huerta, José María; Ardanaz, Eva; Ohlsson, Bodil; Sjöberg, Klas; Werner, Mårten; Nystrom, Hanna; Khaw, Kay-Tee; Key, Timothy J; Gunter, Marc; Cross, Amanda; Riboli, Elio; Romieu, Isabelle; Jenab, Mazda

2016-02-01

Serum liver biomarkers (gamma-glutamyl transferase, GGT; alanine aminotransferase, ALT; aspartate aminotransferase, AST; alkaline phosphatase, ALP; total bilirubin) are used as indicators of liver disease, but there is currently little data on their prospective association with risk of hepatobiliary cancers. A nested-case control study was conducted within the prospective EPIC cohort (>520,000 participants, 10 European countries). After a mean 7.5 mean years of follow-up, 121 hepatocellular carcinoma (HCC), 34 intrahepatic bile duct (IHBC) and 131 gallbladder and biliary tract (GBTC) cases were identified and matched to 2 controls each. Circulating biomarkers were measured in serum taken at recruitment into the cohort, prior to cancer diagnosis. Multivariable adjusted conditional logistic regression was used to calculate odds ratios and 95% confidence intervals (OR; 95%CI). In multivariable models, 1SD increase of each log-transformed biomarker was positively associated with HCC risk (OR(GGT)=4.23, 95%CI:2.72-6.59; OR(ALP)=3.43, 95%CI:2.31-5.10;OR(AST)=3.00, 95%CI:2.04-4.42; OR(ALT)=2.69, 95%CI:1.89-3.84; OR(Bilirubin)=2.25, 95%CI:1.58-3.20). Each liver enzyme (OR(GGT)=4.98; 95%CI:1.75-14.17; OR(AST)=3.10, 95%CI:1.04-9.30; OR(ALT)=2.86, 95%CI:1.26-6.48, OR(ALP)=2.31, 95%CI:1.10-4.86) but not bilirubin (OR(Bilirubin)=1.46,95%CI:0.85-2.51) showed a significant association with IHBC. Only ALP was significantly associated with GBTC risk (OR(ALP)=1.59, 95%CI:1.20-2.09). This study shows positive associations between circulating liver biomarkers in sera collected prior to cancer diagnoses and the risks of developing HCC or IHBC, but not GBTC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of epimorphin in bile duct formation of rat liver epithelial stem-like cells: involvement of small G protein RhoA and C/EBPβ.

PubMed

Jia, Yali; Yao, Hailei; Zhou, Junnian; Chen, Lin; Zeng, Quan; Yuan, Hongfeng; Shi, Lei; Nan, Xue; Wang, Yunfang; Yue, Wen; Pei, Xuetao

2011-11-01

Epimorphin/syntaxin 2 is a high conserved and very abundant protein involved in epithelial morphogenesis in various organs. We have shown recently that epimorphin (EPM), a protein exclusively expressed on the surface of hepatic stellate cells and myofibroblasts of the liver, induces bile duct formation of hepatic stem-like cells (WB-F344 cells) in a putative biophysical way. Therefore, the aim of this study was to present some of the molecular mechanisms by which EPM mediates bile duct formation. We established a biliary differentiation model by co-culture of EPM-overexpressed mesenchymal cells (PT67(EPM)) with WB-F344 cells. Here, we showed that EPM could promote WB-F344 cells differentiation into bile duct-like structures. Biliary differentiation markers were also elevated by EPM including Yp, Cx43, aquaporin-1, CK19, and gamma glutamyl transpeptidase (GGT). Moreover, the signaling pathway of EPM was analyzed by focal adhesion kinase (FAK), extracellular regulated kinase 1/2 (ERK1/2), and RhoA Western blot. Also, a dominant negative (DN) RhoA-WB-F344 cell line (WB(RhoA-DN)) was constructed. We found that the levels of phosphorylation (p) of FAK and ERK1/2 were up-regulated by EPM. Most importantly, we also showed that RhoA is necessary for EPM-induced activation of FAK and ERK1/2 and bile duct formation. In addition, a dual luciferase-reporter assay and CHIP assay was performed to reveal that EPM regulates GGT IV and GGT V expression differentially, possibly mediated by C/EBPβ. Taken together, these data demonstrated that EPM regulates bile duct formation of WB-F344 cells through effects on RhoA and C/EBPβ, implicating a dual aspect of this morphoregulator in bile duct epithelial morphogenesis. Copyright © 2011 Wiley-Liss, Inc.

Multiwavelength Study of Gamma-Ray Bright Blazars

NASA Astrophysics Data System (ADS)

Morozova, Daria; Larionov, V. M.; Hagen-Thorn, V. A.; Jorstad, S. G.; Marscher, A. P.; Troitskii, I. S.

2011-01-01

We investigate total intensity radio images of 6 gamma-ray bright blazars (BL Lac, 3C 279, 3C 273, W Com, PKS 1510-089, and 3C 66A) and their optical and gamma-ray light curves to study connections between gamma-ray and optical brightness variations and changes in the parsec-scale radio structure. We use high-resolution maps obtained by the BU group at 43 GHz with the VLBA, optical light curves constructed by the St.Petersburg State U. (Russia) team using measurements with the 0.4 m telescope of St.Petersburg State U. (LX200) and the 0.7 m telescope of the Crimean Astrophysical Observatory (AZT-8), and gamma-ray light curves, which we have constructed with data provided by the Fermi Large Area Telescope. Over the period from August 2008 to November 2009, superluminal motion is found in all 6 objects with apparent speed ranging from 2c to 40c. The blazars with faster apparent speeds, 3C 273, 3C 279, PKS 1510-089, and 3C 66A, exhibit stronger variability of the gamma-ray emission. There is a tendency for sources with sharply peaked gamma-ray flares to have faster jet speed than sources with gamma-ray light curves with no sharp peaks. Gamma-ray light curves with sharply peaked gamma-ray flares possess a stronger gamma-ray/optical correlations. The research at St.Petersburg State U. was funded by the Minister of Education and Science of the Russian Federation (state contract N#P123). The research at BU was funded in part by NASA Fermi Guest Investigator grant NNX08AV65G and by NSF grant AST-0907893. The VLBA is an instrument of the National Radio Astronomy Observatory, a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Accurate Wavelength Measurement of High-Energy Gamma Rays from the 35Cl(n,{gamma}) Reactions

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

Belgya, T.; Molnar, G.L.; Mutti, P.

2005-05-24

The energies of eight gamma rays in the 36Cl level scheme have been measured with high precision using the 35Cl(n,{gamma}) reaction and the GAMS4 spectrometer. From these energies, a skeleton decay scheme for 36Cl was constructed, and the binding energy of 36Cl was determined to higher precision than previously. It is shown that using this new information, binding energy determination from Ge detector experiments for other nuclei can also be made with higher precision than now available. The measurement of additional weaker 36Cl gamma rays is continuing.

Search of the energetic gamma-ray experiment telescope (EGRET) data for high-energy gamma-ray microsecond bursts

NASA Technical Reports Server (NTRS)

Fichtel, C. E.; Bertsch, D. L.; Dingus, B. L.; Esposito, J. A.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.; Mattox, J. R.

1994-01-01

Hawking (1974) and Page & Hawking (1976) investigated theoretically the possibility of detecting high-energy gamma rays produced by the quantum-mechanical decay of a small black hole created in the early universe. They concluded that, at the very end of the life of the small black hole, it would radiate a burst of gamma rays peaked near 250 MeV with a total energy of about 10(exp 34) ergs in the order of a microsecond or less. The characteristics of a black hole are determined by laws of physics beyond the range of current particle accelerators; hence, the search for these short bursts of high-energy gamma rays provides at least the possibility of being the first test of this region of physics. The Compton Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) has the capability of detecting directly the gamma rays from such bursts at a much fainter level than SAS 2, and a search of the EGRET data has led to an upper limit of 5 x 10(exp -2) black hole decays per cu pc per yr, placing constraints on this and other theories predicting microsecond high-energy gamma-ray bursts.

Gamma-ray transfer and energy deposition in supernovae

NASA Technical Reports Server (NTRS)

Swartz, Douglas A.; Sutherland, Peter G.; Harkness, Robert P.

1995-01-01

Solutions to the energy-independent (gray) radiative transfer equations are compared to results of Monte Carlo simulations of the Ni-56 and Co-56 decay gamma-ray energy deposition in supernovae. The comparison shows that an effective, purely absorptive, gray opacity, kappa(sub gamma) approximately (0. 06 +/- 0.01)Y(sub e) sq cm/g, where Y is the total number of electrons per baryon, accurately describes the interaction of gamma-rays with the cool supernova gas and the local gamma-ray energy deposition within the gas. The nature of the gamma-ray interaction process (dominated by Compton scattering in the relativistic regime) creates a weak dependence of kappa(sub gamma) on the optical thickness of the (spherically symmetric) supernova atmosphere: The maximum value of kappa(sub gamma) applies during optically thick conditions when individual gamma-rays undergo multiple scattering encounters and the lower bound is reached at the phase characterized by a total Thomson optical depth to the center of the atmosphere tau(sub e) approximately less than 1. Gamma-ray deposition for Type Ia supernova models to within 10% for the epoch from maximum light to t = 1200 days. Our results quantitatively confirm that the quick and efficient solution to the gray transfer problem provides an accurate representation of gamma-ray energy deposition for a broad range of supernova conditions.

Escherichia coli K-12 can utilize an exogenous gamma-glutamyl peptide as an amino acid source, for which gamma-glutamyltranspeptidase is essential.

PubMed

Suzuki, H; Hashimoto, W; Kumagai, H

1993-09-01

Escherichia coli K-12 can utilize a gamma-glutamyl peptide as an amino acid source, for which gamma-glutamyltranspeptidase (EC 2.3.2.2) is essential. We suggest that the gamma-glutamyl linkage of a gamma-glutamyl peptide is hydrolyzed by gamma-glutamyltranspeptidase located in the periplasmic space, and the released amino acid is taken up and utilized by E. coli.

Technical Note: Relationships between gamma criteria and action levels: Results of a multicenter audit of gamma agreement index results.

PubMed

Crowe, Scott B; Sutherland, Bess; Wilks, Rachael; Seshadri, Venkatakrishnan; Sylvander, Steven; Trapp, Jamie V; Kairn, Tanya

2016-03-01

The aim of this work was to use a multicenter audit of modulated radiotherapy quality assurance (QA) data to provide a practical examination of gamma evaluation criteria and action level selection. The use of the gamma evaluation method for patient-specific pretreatment QA is widespread, with most commercial solutions implementing the method. Gamma agreement indices were calculated using the criteria 1%/1 mm, 2%/2 mm, 2%/3 mm, 3%/2 mm, 3%/3 mm, and 5%/3 mm for 1265 pretreatment QA measurements, planned at seven treatment centers, using four different treatment planning systems, delivered using three different delivery systems (intensity-modulated radiation therapy, volumetric-modulated arc therapy, and helical tomotherapy) and measured using three different dose measurement systems. The sensitivity of each pair of gamma criteria was evaluated relative to the gamma agreement indices calculated using 3%/3 mm. A linear relationship was observed for 2%/2 mm, 2%/3 mm, and 3%/2 mm. This result implies that most beams failing at 3%/3 mm would also fail for those criteria, if the action level was adjusted appropriately. Some borderline plans might be passed or failed depending on the relative priority (tighter tolerance) used for dose difference or distance to agreement evaluation. Dosimeter resolution and treatment modality were found to have a smaller effect on the results of QA measurements than the number of dimensions (2D or 3D) over which the gamma evaluation was calculated. This work provides a method (and a large sample of results) for calculating equivalent action levels for different gamma evaluation criteria. This work constitutes a valuable guide for clinical decision making and a means to compare published gamma evaluation results from studies using different evaluation criteria. More generally, the data provided by this work support the recommendation that gamma criteria that specifically prioritize the property of greatest clinical importance for each

Characteristics of gamma-ray line flares

NASA Technical Reports Server (NTRS)

Bai, T.; Dennis, B.

1983-01-01

Observations of solar gamma rays by the Solar Maximum Mission (SMM) demonstrate that energetic protons and ions are rapidly accelerated during the impulsive phase. To understand the acceleration mechanisms for these particles, the characteristics of the gamma ray line flares observed by SMM were studied. Some very intense hard X-ray flares without detectable gamma ray lines were also investigated. Gamma ray line flares are distinguished from other flares by: (1) intense hard X-ray and microwave emissions; (2) delay of high energy hard X-rays; (3) emission of type 2 and/or type 4 radio bursts; and (4) flat hard X-ray spectra (average power law index: 3.1). The majority of the gamma ray line flares shared all these characteristics, and the remainder shared at least three of them. Positive correlations were found between durations of spike bursts and spatial sizes of flare loops as well as between delay times and durations of spike bursts.

GRI: The Gamma-Ray Imager mission

NASA Astrophysics Data System (ADS)

Knödlseder, Jürgen; GRI Consortium

With the INTEGRAL observatory ESA has provided a unique tool to the astronomical community revealing hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes. While INTEGRAL provides the global overview over the soft gamma-ray sky, there is a growing need to perform deeper, more focused investigations of gamma-ray sources. In soft X-rays a comparable step was taken going from the Einstein and the EXOSAT satellites to the Chandra and XMM/Newton observatories. Technological advances in the past years in the domain of gamma-ray focusing using Laue diffraction have paved the way towards a new gamma-ray mission, providing major improvements regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow studies of particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

GRI: The Gamma-Ray Imager mission

NASA Astrophysics Data System (ADS)

Knödlseder, Jürgen; GRI Consortium

2006-06-01

With the INTEGRAL observatory, ESA has provided a unique tool to the astronomical community revealing hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes. While INTEGRAL provides the global overview over the soft gamma-ray sky, there is a growing need to perform deeper, more focused investigations of gamma-ray sources. In soft X-rays a comparable step was taken going from the Einstein and the EXOSAT satellites to the Chandra and XMM/Newton observatories. Technological advances in the past years in the domain of gamma-ray focusing using Laue diffraction have paved the way towards a new gamma-ray mission, providing major improvements regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow the study of particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

Identification and characterization of gamma-glutamylamine cyclotransferase, an enzyme responsible for gamma-glutamyl-epsilon-lysine catabolism.

PubMed

Oakley, Aaron J; Coggan, Marjorie; Board, Philip G

2010-03-26

Gamma-glutamylamine cyclotransferase (GGACT) is an enzyme that converts gamma-glutamylamines to free amines and 5-oxoproline. GGACT shows high activity toward gamma-glutamyl-epsilon-lysine, derived from the breakdown of fibrin and other proteins cross-linked by transglutaminases. The enzyme adopts the newly identified cyclotransferase fold, observed in gamma-glutamylcyclotransferase (GGCT), an enzyme with activity toward gamma-glutamyl-alpha-amino acids (Oakley, A. J., Yamada, T., Liu, D., Coggan, M., Clark, A. G., and Board, P. G. (2008) J. Biol. Chem. 283, 22031-22042). Despite the absence of significant sequence identity, several residues are conserved in the active sites of GGCT and GGACT, including a putative catalytic acid/base residue (GGACT Glu(82)). The structure of GGACT in complex with the reaction product 5-oxoproline provides evidence for a common catalytic mechanism in both enzymes. The proposed mechanism, combined with the three-dimensional structures, also explains the different substrate specificities of these enzymes. Despite significant sequence divergence, there are at least three subfamilies in prokaryotes and eukaryotes that have conserved the GGCT fold and GGCT enzymatic activity.

GLAST and Ground-Based Gamma-Ray Astronomy

NASA Technical Reports Server (NTRS)

McEnery, Julie

2008-01-01

The launch of the Gamma-ray Large Area Space Telescope together with the advent of a new generation of ground-based gamma-ray detectors such as VERITAS, HESS, MAGIC and CANGAROO, will usher in a new era of high-energy gamma-ray astrophysics. GLAST and the ground based gamma-ray observatories will provide highly complementary capabilities for spectral, temporal and spatial studies of high energy gamma-ray sources. Joint observations will cover a huge energy range, from 20 MeV to over 20 TeV. The LAT will survey the entire sky every three hours, allowing it both to perform uniform, long-term monitoring of variable sources and to detect flaring sources promptly. Both functions complement the high-sensitivity pointed observations provided by ground-based detectors. Finally, the large field of view of GLAST will allow a study of gamma-ray emission on large angular scales and identify interesting regions of the sky for deeper studies at higher energies. In this poster, we will discuss the science returns that might result from joint GLAST/ground-based gamma-ray observations and illustrate them with detailed source simulations.

RoboPol: the optical polarization of gamma-ray-loud and gamma-ray-quiet blazars

NASA Astrophysics Data System (ADS)

Angelakis, E.; Hovatta, T.; Blinov, D.; Pavlidou, V.; Kiehlmann, S.; Myserlis, I.; Böttcher, M.; Mao, P.; Panopoulou, G. V.; Liodakis, I.; King, O. G.; Baloković, M.; Kus, A.; Kylafis, N.; Mahabal, A.; Marecki, A.; Paleologou, E.; Papadakis, I.; Papamastorakis, I.; Pazderski, E.; Pearson, T. J.; Prabhudesai, S.; Ramaprakash, A. N.; Readhead, A. C. S.; Reig, P.; Tassis, K.; Urry, M.; Zensus, J. A.

2016-12-01

We present average R-band optopolarimetric data, as well as variability parameters, from the first and second RoboPol observing season. We investigate whether gamma-ray-loud and gamma-ray-quiet blazars exhibit systematic differences in their optical polarization properties. We find that gamma-ray-loud blazars have a systematically higher polarization fraction (0.092) than gamma-ray-quiet blazars (0.031), with the hypothesis of the two samples being drawn from the same distribution of polarization fractions being rejected at the 3σ level. We have not found any evidence that this discrepancy is related to differences in the redshift distribution, rest-frame R-band luminosity density, or the source classification. The median polarization fraction versus synchrotron-peak-frequency plot shows an envelope implying that high-synchrotron-peaked sources have a smaller range of median polarization fractions concentrated around lower values. Our gamma-ray-quiet sources show similar median polarization fractions although they are all low-synchrotron-peaked. We also find that the randomness of the polarization angle depends on the synchrotron peak frequency. For high-synchrotron-peaked sources, it tends to concentrate around preferred directions while for low-synchrotron-peaked sources, it is more variable and less likely to have a preferred direction. We propose a scenario which mediates efficient particle acceleration in shocks and increases the helical B-field component immediately downstream of the shock.

30 CFR 57.5047 - Gamma radiation surveys.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Gamma radiation surveys. 57.5047 Section 57..., Radiation, Physical Agents, and Diesel Particulate Matter Radiation-Underground Only § 57.5047 Gamma radiation surveys. (a) Gamma radiation surveys shall be conducted annually in all underground mines where...

30 CFR 57.5047 - Gamma radiation surveys.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Gamma radiation surveys. 57.5047 Section 57..., Radiation, Physical Agents, and Diesel Particulate Matter Radiation-Underground Only § 57.5047 Gamma radiation surveys. (a) Gamma radiation surveys shall be conducted annually in all underground mines where...

Regulation of gamma-Secretase in Alzheimer's Disease

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

Zhou, Shuxia; Zhou, Hua; Walian, Peter

2007-02-07

The {gamma}-secretase complex is an intramembrane aspartyl protease that cleaves its substrates along their transmembrane regions. Sequential proteolytic processing of amyloid precursor protein by {beta}- and {gamma}-secretase produces amyloid {beta}-peptides, which are the major components of amyloid plaques in the brains of Alzheimer's disease patients. The {gamma}-secretase complex is therefore believed to be critical in the pathogenesis of Alzheimer's disease. Here we review the range of factors found to affect the nature and degree of {gamma}-secretase complex activity; these include {gamma}-secretase complex assembly and activation, the integral regulatory subunit CD147, transient or weak binding partners, the levels of cholesterol andmore » sphingolipids in cell membranes, and inflammatory cytokines. Integrated knowledge of the molecular mechanisms supporting the actions of these factors is expected to lead to a comprehensive understanding of the functional regulation of the {gamma}-secretase complex, and this, in turn, should facilitate the development of novel therapeutic strategies for the treatment of Alzheimer's disease.« less

Gamma-ray Albedo of the Moon

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

Moskalenko, Igor V.; Porter, Troy A.

2007-06-14

We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma-rays from the Moon is very steep with an effective cutoff around 3 GeV (600 MeV for the inner part of the Moon disc). Since it is the only (almost) black spot in the gamma-ray sky, it provides a unique opportunity for calibration of gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST).more » The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo -rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.« less

Measuring B to S Gamma, B to D Gamma and |V(Td)/V(Ts)| at BaBar

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

Bard, Deborah; /SLAC

2012-06-01

Using a sample of 471 million B{bar B} events collected with the BaBar detector, we study the sum of seven exclusive final states b {yields} X{sub s(d)}{gamma}, where X{sub s(d)} is a strange (non-strange) hadronic system with a mass of up to 2.0 Gev/c{sup 2}. After correcting for unobserved decay modes, we obtain a branching fraction for b {yields} d{gamma} of (9.2 {+-} 2.0(stat.) {+-} 2.3(syst.)) x 10{sup -6} in this mass range, and a branching fraction for b {yields} s{gamma} of (23.0 {+-} 0.8(stat.) {+-} 3.0(syst.)) x 10{sup -5} in the same mass range. We find BF(b {yields} d{gamma})/BF(bmore » {yields} s{gamma}) = 0.040 {+-} 0.009(stat.) {+-} 0.010(syst.), from which we determine |V{sub td}/V{sub ts}| = 0.199 {+-} 0.022(stat.) {+-} 0.024(syst.) {+-} 0.002(th.).« less

Hippocampal theta, gamma, and theta-gamma coupling: effects of aging, environmental change, and cholinergic activation

PubMed Central

Jacobson, Tara K.; Howe, Matthew D.; Schmidt, Brandy; Hinman, James R.; Escabí, Monty A.

2013-01-01

Hippocampal theta and gamma oscillations coordinate the timing of multiple inputs to hippocampal neurons and have been linked to information processing and the dynamics of encoding and retrieval. One major influence on hippocampal rhythmicity is from cholinergic afferents. In both humans and rodents, aging is linked to impairments in hippocampus-dependent function along with degradation of cholinergic function. Cholinomimetics can reverse some age-related memory impairments and modulate oscillations in the hippocampus. Therefore, one would expect corresponding changes in these oscillations and possible rescue with the cholinomimetic physostigmine. Hippocampal activity was recorded while animals explored a familiar or a novel maze configuration. Reexposure to a familiar situation resulted in minimal aging effects or changes in theta or gamma oscillations. In contrast, exploration of a novel maze configuration increased theta power; this was greater in adult than old animals, although the deficit was reversed with physostigmine. In contrast to the theta results, the effects of novelty, age, and/or physostigmine on gamma were relatively weak. Unrelated to the behavioral situation were an age-related decrease in the degree of theta-gamma coupling and the fact that physostigmine lowered the frequency of theta in both adult and old animals. The results indicate that age-related changes in gamma and theta modulation of gamma, while reflecting aging changes in hippocampal circuitry, seem less related to aging changes in information processing. In contrast, the data support a role for theta and the cholinergic system in encoding and that hippocampal aging is related to impaired encoding of new information. PMID:23303862

Refining the 22q11.2 deletion breakpoints in DiGeorge syndrome by aCGH

PubMed Central

Bittel, D.C.; Yu, S.; Newkirk, H.; Kibiryeva, N.; Holt, S.; Butler, M.G.; Cooley, L.D.

2009-01-01

Hemizygous deletions of the chromosome 22q11.2 region result in the 22q11.2 deletion syndrome also referred to as DiGeorge, Velocardiofacial or Shprintzen syndromes. The phenotype is variable but commonly includes conotruncal cardiac defects, palatal abnormalities, learning and behavioral problems, immune deficiency, and facial anomalies. Four distinct highly homologous blocks of low copy number repeat sequences (LCRs) flank the deletion region. Mispairing of LCRs during meiosis with unequal meiotic exchange is assumed to cause the recurrent and consistent deletions. The proximal LCR is reportedly located at 22q11.2 from 17.037 to 17.083 Mb while the distal LCR is located from 19.835 to 19.880 Mb. Although the chromosome breakpoints are thought to localize to the LCRs, the positions of the breakpoints have been investigated in only a few individuals. Therefore, we used high resolution oligonucleotide-based 244K microarray comparative genomic hybridization (aCGH) to resolve the breakpoints in a cohort of 20 subjects with known 22q11.2 deletions. We also investigated copy number variation (CNV) in the rest of the genome. The 22q11.2 breaks occurred on either side of the LCR in our subjects, although more commonly on the distal side of the reported proximal LCR. The proximal breakpoints in our subjects spanned the region from 17.036 to 17.398 Mb. This region includes the genes DGCR6 (DiGeorge syndrome critical region protein 6) and PRODH (proline dehydrogenase 1), along with three open reading frames that may encode proteins of unknown function. The distal breakpoints spanned the region from 19.788 to 20.122 Mb. This region includes the genes GGT2 (gamma-glutamyltransferase-like protein 2), HIC2 (hypermethylated in cancer 2), and multiple transcripts of unknown function. The genes in these two breakpoint regions are variably hemizygous depending on the location of the breakpoints. Our 20 subjects had 254 CNVs throughout the genome, 94 duplications and 160 deletions

Future Facilities for Gamma-Ray Pulsar Studies

NASA Technical Reports Server (NTRS)

Thompson, D. J.

2003-01-01

Pulsars seen at gamma-ray energies offer insight into particle acceleration to very high energies, along with information about the geometry and interaction processes in the magnetospheres of these rotating neutron stars. During the next decade, a number of new gamma-ray facilities will become available for pulsar studies. This brief review describes the motivation for gamma-ray pulsar studies, the opportunities for such studies, and some specific discussion of the capabilities of the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) for pulsar measurements.

Measurement of absolute gamma emission probabilities

NASA Astrophysics Data System (ADS)

Sumithrarachchi, Chandana S.; Rengan, Krish; Griffin, Henry C.

2003-06-01

The energies and emission probabilities (intensities) of gamma-rays emitted in radioactive decays of particular nuclides are the most important characteristics by which to quantify mixtures of radionuclides. Often, quantification is limited by uncertainties in measured intensities. A technique was developed to reduce these uncertainties. The method involves obtaining a pure sample of a nuclide using radiochemical techniques, and using appropriate fractions for beta and gamma measurements. The beta emission rates were measured using a liquid scintillation counter, and the gamma emission rates were measured with a high-purity germanium detector. Results were combined to obtain absolute gamma emission probabilities. All sources of uncertainties greater than 0.1% were examined. The method was tested with 38Cl and 88Rb.

Gamma Rays at Very High Energies

NASA Astrophysics Data System (ADS)

Aharonian, Felix

This chapter presents the elaborated lecture notes on Gamma Rays at Very High Energies given by Felix Aharonian at the 40th Saas-Fee Advanced Course on "Astrophysics at Very High Energies". Any coherent description and interpretation of phenomena related to gammarays requires deep knowledge of many disciplines of physics like nuclear and particle physics, quantum and classical electrodynamics, special and general relativity, plasma physics, magnetohydrodynamics, etc. After giving an introduction to gamma-ray astronomy the author discusses the astrophysical potential of ground-based detectors, radiation mechanisms, supernova remnants and origin of the galactic cosmic rays, TeV emission of young supernova remnants, gamma-emission from the Galactic center, pulsars, pulsar winds, pulsar wind nebulae, and gamma-ray loud binaries.

Strength of Gamma Rhythm Depends on Normalization

PubMed Central

Ray, Supratim; Ni, Amy M.; Maunsell, John H. R.

2013-01-01

Neuronal assemblies often exhibit stimulus-induced rhythmic activity in the gamma range (30–80 Hz), whose magnitude depends on the attentional load. This has led to the suggestion that gamma rhythms form dynamic communication channels across cortical areas processing the features of behaviorally relevant stimuli. Recently, attention has been linked to a normalization mechanism, in which the response of a neuron is suppressed (normalized) by the overall activity of a large pool of neighboring neurons. In this model, attention increases the excitatory drive received by the neuron, which in turn also increases the strength of normalization, thereby changing the balance of excitation and inhibition. Recent studies have shown that gamma power also depends on such excitatory–inhibitory interactions. Could modulation in gamma power during an attention task be a reflection of the changes in the underlying excitation–inhibition interactions? By manipulating the normalization strength independent of attentional load in macaque monkeys, we show that gamma power increases with increasing normalization, even when the attentional load is fixed. Further, manipulations of attention that increase normalization increase gamma power, even when they decrease the firing rate. Thus, gamma rhythms could be a reflection of changes in the relative strengths of excitation and normalization rather than playing a functional role in communication or control. PMID:23393427

Gamma-delta t-cell lymphomas.

PubMed

Foppoli, Marco; Ferreri, Andrés J M

2015-03-01

Gamma-delta T-cell lymphomas are aggressive and rare diseases originating from gamma-delta lymphocytes. These cells, which naturally play a role in the innate, non-specific immune response, develop from thymic precursor in the bone marrow, lack the major histocompatibility complex restrictions and can be divided into two subpopulations: Vdelta1, mostly represented in the intestine, and Vdelta2, prevalently located in the skin, tonsils and lymph nodes. Chronic immunosuppression such as in solid organ transplanted subjects and prolonged antigenic exposure are probably the strongest risk factors for the triggering of lymphomagenesis. Two entities are recognised by the 2008 WHO Classification: hepatosplenic gamma-delta T-cell lymphoma (HSGDTL) and primary cutaneous gamma-delta T-cell lymphoma (PCGDTL). The former is more common among young males, presenting with B symptoms, splenomegaly and thrombocytopenia, usually with the absence of nodal involvement. Natural behaviour of HSGDTL is characterised by low response rates, poor treatment tolerability, common early progression of disease and disappointing survival figures. PCGDTL accounts for <1% of all primary cutaneous lymphomas, occurring in adults with relevant comorbidities. Cutaneous lesions may vary, but its clinical behaviour is usually aggressive and long-term survival is anecdotal. Available literature on gamma-delta T-cell lymphomas is fractioned, mostly consisting of case reports or small cumulative series. Therefore, clinical suspicion and diagnosis are usually delayed, and therapeutic management remains to be established. This review critically analyses available evidence on diagnosis, staging and behaviour of gamma-delta T-cell lymphomas, provides recommendations for therapeutic management in routine practice and discusses relevant unmet clinical needs for future studies. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

AN ORIENTATIONAL RESPONSE TO WEAK GAMMA RADIATION

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

Brown, F.A. Jr.

1963-10-01

The common planarian worm, Duesia dorotocephsla, displays a significant orientational response to increase in Cs/sup 137/ gamma radiation when the increase is no greater than six times background. The worms are able to distinguish the direction of the weak gamma source, turning away from it, whether it is presented on the right or left side. The response sign is, therefore, the same as that of the response of these negatively phototactic worms to visible light. There is a clear compass-directional relationship of the responsiveness to the experimental gamma radiation. A conspicuous negative response is present when the worms are travelingmore » northward or southward in the earth's field with the gamma change in an east-west axis. No statistically significant mean turning response to the gamma radiation is found when the worms are traveling eastward or westward in the earth's field with the gamma change in a north-south axis. The previously observed annual fluctuation in the character of the monthly orientational rhythm of north-directed worms has been confirmed in an additional year of study. During colder months, the rhythm is monthly; during warmer months it is semi-monthly. There is a semi-monthly fluctuation in the response of Dugesia to weak gamma radiation during mid-morning hours, the worms turning away from the source for four days prior to new end full moon, and toward it for two days following new and full moon. The stronger the field strength, up to 9 times backgound, the larger the amplitude of the rhythm. There is a direct relationship between intensities of gamma radiation between that of background and nine times backgound, and the strength of the negative response of the worms. Evidence suggests that the negative response of Dugesia to a gamma source may be modified by experimental alteration of the natural ambient electrostatic field. Some possible biological significances of this remarkable responsiveness to gamma radiation, and its particular

Discoveries by the Fermi Gamma Ray Space Telescope

NASA Technical Reports Server (NTRS)

Gehrels, Neil

2011-01-01

Fermi is a large space gamma-ray mission developed by NASA and the DOE with major contributions from France, Germany, Italy, Japan and Sweden. It was launched in June 2008 and has been performing flawlessly since then. The main instrument is the Large Area Telescope (LAT) operating in the 20 MeV to 300 GeV range and a smaller monitor instrument is the Gamma-ray Burst Monitor (GBM) operating in the 8 keV to 40 MeV range. New findings are occurring every week. Some of the key discoveries are: 1) Discovery of many new gamma-ray pulsars, including gamma-ray only and millisecond pulsars. 2) Detection of high energy gamma-ray emission from globular clusters, most likely due to summed emission from msec pulsars. 3) Discovery of delayed and extended high energy gamma-ray emission from short and long gamma-ray busts. 4) Detection of approximately 250 gamma-ray bursts per year with the GBM instrument. 5) Most accurate measurement of the cosmic ray electron spectrum between 30 GeV and 1 TeV, showing some excess above the conventional diffusion model. The talk will present the new discoveries and their implications.

Human antirabies gamma globulin*

PubMed Central

Hosty, Thomas S.; Kissling, R. E.; Schaeffer, M.; Wallace, Gordon A.; Dibble, E. H.

1959-01-01

To obviate the foreign protein reactions experienced with the use of hyperimmune serum in rabies-exposed individuals, an attempt was made to produce a rabies antiserum of human origin. Five doses of an inactivated rabies virus duck-egg vaccine were administered to 34 volunteers at 4-day intervals (i.e., on days 0, 4, 8, 12 and 16). An additional dose of chick-embryo attenuated virus vaccine—Flury HEP (high egg passage)—was given on the 46th day, followed by a final booster dose of duck-egg vaccine on the 288th day. Twenty-four days later, i.e., on the 312th day after the first dose, the participants were bled and the serum pooled and converted to gamma globulin. These volunteers, having no initial antibody, responded with variable titres, the pooled serum having a titre of 1: 100 against 50 LD50 of rabies virus in neutralization tests and the gamma globulin prepared from this pool a titre of 1: 300. In five individuals inoculated with the antirabies gamma globulin, blood samples tested at intervals for residual antibody showed significant titres through 21 days. While the passive antibody levels resulting from the administration of a more potent immune horse serum were much higher than those achieved by the weaker human antirabies gamma globulin used, the decrease in titre was more gradual with the human globulin. With more booster inoculations in a larger group of human volunteers, it is believed that a human rabies immune gamma globulin could be produced which would be equal in effect to immune horse serum. The advantages of a human source of antibody in rabies prophylaxis are discussed. PMID:14403320

Increased visual gamma power in schizoaffective bipolar disorder.

PubMed

Brealy, J A; Shaw, A; Richardson, H; Singh, K D; Muthukumaraswamy, S D; Keedwell, P A

2015-03-01

Electroencephalography and magnetoencephalography (MEG) studies have identified alterations in gamma-band (30-80 Hz) cortical activity in schizophrenia and mood disorders, consistent with neural models of disturbed glutamate (and GABA) neuron influence over cortical pyramidal cells. Genetic evidence suggests specific deficits in GABA-A receptor function in schizoaffective bipolar disorder (SABP), a clinical syndrome with features of both bipolar disorder and schizophrenia. This study investigated gamma oscillations in this under-researched disorder. MEG was used to measure induced gamma and evoked responses to a visual grating stimulus, known to be a potent inducer of primary visual gamma oscillations, in 15 individuals with remitted SABP, defined using Research Diagnostic Criteria, and 22 age- and sex-matched healthy controls. Individuals with SABP demonstrated increased sustained visual cortical power in the gamma band (t 35 = -2.56, p = 0.015) compared to controls. There were no group differences in baseline gamma power, transient or sustained gamma frequency, alpha band responses or pattern onset visual-evoked responses. Gamma power is increased in remitted SABP, which reflects an abnormality in the cortical inhibitory-excitatory balance. Although an interaction between gamma power and medication can not be ruled out, there were no group differences in evoked responses or baseline measures. Further work is needed in other clinical populations and at-risk relatives. Pharmaco-magnetoencephalography studies will help to elucidate the specific GABA and glutamate pathways affected.

Cen A Optical Gamma Composite

NASA Image and Video Library

2017-12-08

NASA release April 1, 2010 The gamma-ray output from Cen A's lobes exceeds their radio output by more than ten times. High-energy gamma rays detected by Fermi's Large Area Telescope are depicted as purple in this gamma ray/optical composite of the galaxy. Credit: NASA/DOE/Fermi LAT Collaboration, Capella Observatory To learn more about these images go to: www.nasa.gov/mission_pages/GLAST/news/smokestack-plumes.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Gamma Ray Bursts

NASA Technical Reports Server (NTRS)

Gehrels, Neil; Meszaros, Peter

2012-01-01

Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day ,last typically lOs of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

Gamma-Terpinene Modulates Acute Inflammatory Response in Mice.

PubMed

Ramalho, Theresa Raquel de Oliveira; Oliveira, Maria Talita Pacheco de; Lima, Ana Luisa de Araujo; Bezerra-Santos, Claudio Roberto; Piuvezam, Marcia Regina

2015-09-01

The monoterpene gamma-terpinene is a natural compound present in essential oils of a wide variety of plants, including the Eucalyptus genus, which has been reported to possess anti-inflammatory activity. The goal of this study was to evaluate the effect of gamma-terpinene on several in vivo experimental models of acute inflammation. Swiss mice were pretreated with gamma-terpinene and subjected to protocols of paw edema with different phlogistic agents such as carrageenan, prostaglandin-E2, histamine, or bradykinin. The microvascular permeability was measured by intraperitoneal injection of acetic acid and measuring the amount of protein extravasation. Carrageenan-induced peritonitis was used to analyze the effect of gamma-terpinene on inflammatory cell migration and cytokine production. We also developed an acute lung injury protocol to define the anti-inflammatory effect of gamma-terpinene. Mice pretreated with gamma-terpinene displayed reduced paw edema induced by carrageenan from 1-24 h after challenge. A similar reduction was observed when gamma-terpinene was administered after stimulation with PGE2, bradykinin, and histamine. Treatment with gamma-terpinene also inhibited fluid extravasation in the acetic acid model of microvascular permeability. In a carrageenan-induced peritonitis model, gamma-terpinene treatment reduced neutrophil migration as well as the production of interleukin-1β and tumor necrosis factor-α when compared to nontreated animals, and in the acute lung injury protocol, gamma-terpinene diminished the neutrophil migration into lung tissue independently of the total protein extravasation in the lung. These data demonstrate that, in different models of inflammation, treatment with gamma-terpinene alleviated inflammatory parameters such as edema and pro-inflammatory cytokine production, as well as cell migration into the inflamed site, and that this monoterpene has anti-inflammatory properties. Georg Thieme Verlag KG Stuttgart · New York.

Impact of Image Noise on Gamma Index Calculation

NASA Astrophysics Data System (ADS)

Chen, M.; Mo, X.; Parnell, D.; Olivera, G.; Galmarini, D.; Lu, W.

2014-03-01

Purpose: The Gamma Index defines an asymmetric metric between the evaluated image and the reference image. It provides a quantitative comparison that can be used to indicate sample-wised pass/fail on the agreement of the two images. The Gamma passing/failing rate has become an important clinical evaluation tool. However, the presence of noise in the evaluated and/or reference images may change the Gamma Index, hence the passing/failing rate, and further, clinical decisions. In this work, we systematically studied the impact of the image noise on the Gamma Index calculation. Methods: We used both analytic formulation and numerical calculations in our study. The numerical calculations included simulations and clinical images. Three different noise scenarios were studied in simulations: noise in reference images only, in evaluated images only, and in both. Both white and spatially correlated noises of various magnitudes were simulated. For clinical images of various noise levels, the Gamma Index of measurement against calculation, calculation against measurement, and measurement against measurement, were evaluated. Results: Numerical calculations for both the simulation and clinical data agreed with the analytic formulations, and the clinical data agreed with the simulations. For the Gamma Index of measurement against calculation, its distribution has an increased mean and an increased standard deviation as the noise increases. On the contrary, for the Gamma index of calculation against measurement, its distribution has a decreased mean and stabilized standard deviation as the noise increases. White noise has greater impact on the Gamma Index than spatially correlated noise. Conclusions: The noise has significant impact on the Gamma Index calculation and the impact is asymmetric. The Gamma Index should be reported along with the noise levels in both reference and evaluated images. Reporting of the Gamma Index with switched roles of the images as reference and

Effects of aberrant gamma frequency oscillations on prepulse inhibition.

PubMed

Jones, Nigel C; Anderson, Paul; Rind, Gil; Sullivan, Caley; van den Buuse, Maarten; O'Brien, Terence J

2014-10-01

Emerging literature implicates abnormalities in gamma frequency oscillations in the pathophysiology of schizophrenia, with hypofunction of N-methyl-D-aspartate (NMDA) receptors implicated as a key factor. Prepulse inhibition (PPI) is a behavioural measure of sensorimotor gating, which is disrupted in schizophrenia. We studied relationships between ongoing and sensory-evoked gamma oscillations and PPI using pharmacological interventions designed to increase gamma oscillations (ketamine, MK-801); reduce gamma oscillations (LY379268); or disrupt PPI (amphetamine). We predicted that elevating ongoing gamma power would lead to increased 'neural noise' in cortical circuits, dampened sensory-evoked gamma responses and disrupted behaviour. Wistar rats were implanted with EEG recording electrodes. They received ketamine (5 mg/kg), MK-801 (0.16 mg/kg), amphetamine (0.5 mg/kg), LY379268 (3 mg/kg) or vehicle and underwent PPI sessions with concurrent EEG recording. Ketamine and MK-801 increased the power of ongoing gamma oscillations and caused time-matched disruptions of PPI, while amphetamine marginally affected ongoing gamma power. In contrast, LY379268 reduced ongoing gamma power, but had no effect on PPI. The sensory gamma response evoked by the prepulse was reduced following treatment with all psychotomimetics, associating with disruptions in PPI. This was most noticeable following treatment with NMDA receptor antagonists. We found that ketamine and MK-801 increase ongoing gamma power and reduce evoked gamma power, both of which are related to disruptions in sensorimotor gating. This appears to be due to antagonism of NMDA receptors, since amphetamine and LY379268 differentially impacted these outcomes and possess different neuropharmacological substrates. Aberrant gamma frequency oscillations caused by NMDA receptor hypofunction may mediate the sensory processing deficits observed in schizophrenia.

Fermi: The Gamma-Ray Large Area Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2015-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Fermi: The Gamma-Ray Large Area Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10 seconds of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Identification of the low affinity receptor for immunoglobulin E on mouse mast cells and macrophages as Fc gamma RII and Fc gamma RIII.

PubMed

Takizawa, F; Adamczewski, M; Kinet, J P

1992-08-01

In addition to their well characterized high affinity immunoglobulin E (IgE) receptors (Fc epsilon RI) mast cells have long been suspected to express undefined Fc receptors capable of binding IgE with low affinity. In this paper, we show that Fc gamma RII and Fc gamma RIII, but not Mac-2, on mouse mast cells and macrophages bind IgE-immune complexes. This binding is efficiently competed by 2.4G2, a monoclonal antibody against the extracellular homologous region of both Fc gamma RII and Fc gamma RIII. Furthermore, IgE-immune complexes bind specifically to Fc gamma RII or Fc gamma RIII transfected into COS-7 cells. The association constants of IgE binding estimated from competition experiments are about 3.1 x 10(5) M-1 for Fc gamma RII, and 4.8 x 10(5) M-1 for Fc gamma RIII. Engagement of Fc gamma RII and Fc gamma RIII with IgE-immune complexes (after blocking access to Fc epsilon RI) or with IgG-immune complexes triggers C57.1 mouse mast cells to release serotonin. This release is inhibited by 2.4G2, and at maximum, reaches 30-40% of the intracellular content, about half of the maximal release (60-80%) obtained after Fc epsilon RI engagement. These data demonstrate that mouse Fc gamma RII and Fc gamma RIII are not isotype specific, and that the binding of IgE-immune complexes to these receptors induces cell activation.

Fermi gamma-ray imaging of a radio galaxy.

PubMed

Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Celik, O; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Colafrancesco, S; Cominsky, L R; Conrad, J; Costamante, L; Cutini, S; Davis, D S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Finke, J; Focke, W B; Fortin, P; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Georganopoulos, M; Germani, S; Giebels, B; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hughes, R E; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Roth, M; Ryde, F; Sadrozinski, H F-W; Sambruna, R; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Stawarz, Ł; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wallace, E; Wang, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M; Hardcastle, M J; Kazanas, D

2010-05-07

The Fermi Gamma-ray Space Telescope has detected the gamma-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved gamma-ray image shows the lobes clearly separated from the central active source. In contrast to all other active galaxies detected so far in high-energy gamma-rays, the lobe flux constitutes a considerable portion (greater than one-half) of the total source emission. The gamma-ray emission from the lobes is interpreted as inverse Compton-scattered relic radiation from the cosmic microwave background, with additional contribution at higher energies from the infrared-to-optical extragalactic background light. These measurements provide gamma-ray constraints on the magnetic field and particle energy content in radio galaxy lobes, as well as a promising method to probe the cosmic relic photon fields.

Nuclear gamma rays from energetic particle interactions

NASA Technical Reports Server (NTRS)

Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

1978-01-01

Gamma ray line emission from nuclear deexcitation following energetic particle reactions is evaluated. The compiled nuclear data and the calculated gamma ray spectra and intensities can be used for the study of astrophysical sites which contain large fluxes of energetic protons and nuclei. A detailed evaluation of gamma ray line production in the interstellar medium is made.

Metabolic modulation of neuronal gamma-band oscillations.

PubMed

Vodovozov, Wadim; Schneider, Justus; Elzoheiry, Shehabeldin; Hollnagel, Jan-Oliver; Lewen, Andrea; Kann, Oliver

2018-05-28

Gamma oscillations (30-100 Hz) represent a physiological fast brain rhythm that occurs in many cortex areas in awake mammals, including humans. They associate with sensory perception, voluntary movement, and memory formation and require precise synaptic transmission between excitatory glutamatergic neurons and inhibitory GABAergic interneurons such as parvalbumin-positive basket cells. Notably, gamma oscillations are exquisitely sensitive to shortage in glucose and oxygen supply (metabolic stress), with devastating consequences for higher cognitive functions. Herein, we explored the robustness of gamma oscillations against changes in the availability of alternative energy substrates and amino acids, which is partially regulated by glial cells such as astrocytes. We used organotypic slice cultures of the rat hippocampus expressing acetylcholine-induced persistent gamma oscillations under normoxic recording conditions (20% oxygen fraction). Our main findings are (1) partial substitution of glucose with pyruvate and the ketone body β-hydroxybutyrate increases the frequency of gamma oscillations, even at different stages of neuronal tissue development. (2) Supplementation with the astrocytic neurotransmitter precursor glutamine has no effect on the properties of gamma oscillations. (3) Supplementation with glycine increases power, frequency, and inner coherence of gamma oscillations in a dose-dependent manner. (4) During these treatments switches to other frequency bands or pathological network states such as neural burst firing or synchronized epileptic activity are absent. Our study indicates that cholinergic gamma oscillations show general robustness against these changes in nutrient and amino acid composition of the cerebrospinal fluid; however, modulation of their properties may impact on cortical information processing under physiological and pathophysiological conditions.

More Gamma More Predictions: Gamma-Synchronization as a Key Mechanism for Efficient Integration of Classical Receptive Field Inputs with Surround Predictions

PubMed Central

Vinck, Martin; Bosman, Conrado A.

2016-01-01

During visual stimulation, neurons in visual cortex often exhibit rhythmic and synchronous firing in the gamma-frequency (30–90 Hz) band. Whether this phenomenon plays a functional role during visual processing is not fully clear and remains heavily debated. In this article, we explore the function of gamma-synchronization in the context of predictive and efficient coding theories. These theories hold that sensory neurons utilize the statistical regularities in the natural world in order to improve the efficiency of the neural code, and to optimize the inference of the stimulus causes of the sensory data. In visual cortex, this relies on the integration of classical receptive field (CRF) data with predictions from the surround. Here we outline two main hypotheses about gamma-synchronization in visual cortex. First, we hypothesize that the precision of gamma-synchronization reflects the extent to which CRF data can be accurately predicted by the surround. Second, we hypothesize that different cortical columns synchronize to the extent that they accurately predict each other’s CRF visual input. We argue that these two hypotheses can account for a large number of empirical observations made on the stimulus dependencies of gamma-synchronization. Furthermore, we show that they are consistent with the known laminar dependencies of gamma-synchronization and the spatial profile of intercolumnar gamma-synchronization, as well as the dependence of gamma-synchronization on experience and development. Based on our two main hypotheses, we outline two additional hypotheses. First, we hypothesize that the precision of gamma-synchronization shows, in general, a negative dependence on RF size. In support, we review evidence showing that gamma-synchronization decreases in strength along the visual hierarchy, and tends to be more prominent in species with small V1 RFs. Second, we hypothesize that gamma-synchronized network dynamics facilitate the emergence of spiking output that

Shear rupture of a directionally solidified eutectic gamma/gamma prime - alpha (Mo) alloy

NASA Technical Reports Server (NTRS)

Harf, F. H.

1978-01-01

Directionally solidified Mo alloys are evaluated to determine the shear rupture strength and to possibly improve it by microstructural and heat treatment variations. Bars of the alloy containing nominally 5.7% Al and 33.5% Mo by weight with balance Ni were directionally solidified at rates between 10 and 100 mm per hour in furnaces with thermal gradients at the liquid-solid interface of 250 or 100 C per cm. A limited number of longitudinal shear rupture tests were conducted at 760 C and 207 MPa in the as - solidified and in several heat treated conditions. It is shown that shear rupture failures are partly transgranular and that resistance to failure is prompted by good fiber alignment and a matrix structure consisting mainly of gamma prime. Well aligned as - solidified specimens sustained the shear stress for an average of 81 hours. A simulated coating heat treatment appeared to increase the transformation of gamma to gamma prime and raised the average shear life of aligned specimens to 111 hours. However, heat treatments at 1245 C and especially at 1190 C appeared to be detrimental by causing partial solutioning of the gamma prime, and reducing lives to 47 and 10 hours, respectively.

‘Gamma Anna’: a classroom demonstration for teaching the concepts of gamma imaging

NASA Astrophysics Data System (ADS)

Wolff, Nicola; Griffiths, Jennifer; Yerworth, Rebecca

2017-01-01

Gamma imaging is at the interface of medicine and physics and thus its teaching is important in both fields. Pedagogic literature highlights the benefits of interactive demonstrations in teaching: an increase in enjoyment and interest, as well as improvement in academic achievement. However gamma imaging uses radioactive sources, which are potentially dangerous and thus their use is tightly controlled. We have developed a demonstration which uses a localised exothermic reaction within a rag doll as an analogue of radioactivity. This can be safely used in classrooms to demonstrate the principles of gamma imaging. The tool is easy to make, cheap, robust and portable. The supplementary material in this paper gives teacher notes and a description of how to make the rag doll demonstrator. We have tested the tool using six participants, acting as ‘teachers’, who carried out the demonstration and described the doll as easy to use, and the ‘tumour’ clearly identifiable. The teaching tool was separately demonstrated to a group of 12 GCSE physics students and a group of 12 medical students. Feedback showed increased student engagement, enjoyment and understanding of gamma imaging. Previous research has shown that these benefits have an impact on learning and academic outcomes.

POCKET $beta$ AND $gamma$ RADIOMETER (in Russian)

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

Markelov, V.V.; Lushikhin, A.M.; Nikoforov, V.I.

A pocket BETA and gamma rate meter was designed by the Academy of Medical Sciences of U.S.S.R. for detecting gamma radiation of 0.25 to 2 Mev and for BETA particles of 0 to 50 and 0 to 500 particles/cm/sup 2/sec, with energies of 0.5 to 2 Mev. Measurements of BETA particles are made through the hack wall opening in the appuratus. The opening is closed durtng the recording of gamma radiation, which permits differentiation between the BETA and gamma radiation. The accuracy of the counter is within plus or minus 15%. (R.V.J.)

Gamma ray astronomy and black hole astrophysics

NASA Technical Reports Server (NTRS)

Liang, Edison P.

1990-01-01

The study of soft gamma emissions from black-hole candidates is identified as an important element in understanding black-hole phenomena ranging from stellar-mass black holes to AGNs. The spectra of Cyg X-1 and observations of the Galactic Center are emphasized, since thermal origins and MeV gamma-ray bumps are evident and suggest a thermal-pair cloud picture. MeV gamma-ray observations are suggested for studying black hole astrophysics such as the theorized escaping pair wind, the anticorrelation between the MeV gamma bump and the soft continuum, and the relationship between source compactness and temperature.

Stable homotopical algebra and [Gamma]-spaces

NASA Astrophysics Data System (ADS)

Schwede, Stefan

1999-03-01

In this paper we advertise the category of [Gamma]-spaces as a convenient framework for doing ‘algebra’ over ‘rings’ in stable homotopy theory. [Gamma]-spaces were introduced by Segal [Se] who showed that they give rise to a homotopy category equivalent to the usual homotopy category of connective (i.e. ([minus sign]1)-connected) spectra. Bousfield and Friedlander [BF] later provided model category structures for [Gamma]-spaces. The study of ‘rings, modules and algebras’ based on [Gamma]-spaces became possible when Lydakis [Ly] introduced a symmetric monoidal smash product with good homotopical properties. Here we develop model category structures for modules and algebras, set up (derived) smash products and associated spectral sequences and compare simplicial modules and algebras to their Eilenberg-MacLane spectra counterparts.

Human serum cholinesterase from liver pathological samples exhibit highly elevated aryl acylamidase activity.

PubMed

Boopathy, Rathanam; Rajesh, Ramanna Valmiki; Darvesh, Sultan; Layer, Paul G

2007-05-01

Although aspartate aminotransferase (AST) and gamma-glutamyltransferase (gamma GT) enzymes are widely used as markers for liver disorders, the ubiquitous enzyme butyrylcholinesterase (BChE), synthesized in liver is also used as marker in the assessment of liver pathophysiology. This BChE enzyme in addition to its esterase activity has yet another enzymatic function designated as aryl acylamidase (AAA) activity. It is determined in in vitro based on the hydrolysis of the synthetic substrate o-nitroacetanilide. In the present study, human serum cholinesterase (BChE) activity was studied with respect to its AAA activity on the BChE protein (AAA(BChE)) in patients with liver disorders. AST and gamma GT values were taken into account in this study as known markers for liver disorders. Blood samples were grouped into 3 based on esterase activity associated with BChE protein. They are normal, low, and very low BChE activity but with markedly increased AST and gamma GT levels. These samples were tested for their respective AAA function. Association of AAA with BChE from samples was proved using BChE monoclonal antibody precipitation experiment. The absolute levels of AAA were increased as BChE activity decreased while deviating from normal samples and such deviation was directly proportional to the severity of the liver disorder. Differences between these groups became prominent after determining the ratios of AAA(BChE) to BChE activities. Samples showing very high AAA(BChE) to BChE ratio were also showing high to very high gamma GT values. These findings establish AAA(BChE) as an independently regulated enzymatic activity on BChE especially in liver disorders. Moreover, since neither the low esterase activity of BChE by itself nor increased levels of AST/gamma GT are sufficient pathological indicators, this pilot study merits replication with large sample numbers.

The Effects of Composition and gamma'/gamma Lattice Parameter Mismatch on the Critical Resolved Shear Stresses for Octahedral and Cube Slip in NiAlCrX Alloys

NASA Technical Reports Server (NTRS)

Miner, R. V.

1997-01-01

Prototypical single-crystal NiAlCrX superalloys were studied to examine the effects of the common major alloying elements, Co, Mo, Nb, Ta, Ti, and W, on yielding behavior. The alloys contained about 10 at. pct Cr, 60 vol pct of the gamma' phase, and about 3 at. pct of X in the gamma'. The critical resolved shear stresses (CRSSs) for octahedral and primary cube slip were measured at 760 C, which is about the peak strength temperature. The CRSS(sub oct) and CRSS(sub cube) are discussed in relation to those of Ni, (Al, X) gamma' alloys taken from the literature and the gamma'/gamma lattice mismatch. The CRSS(sub oct) of the gamma + gamma' alloys reflected a similar compositional dependence to that of both the CRSS(sub cube) of the gamma' phase and the gamma'/gamma lattice parameter mismatch. The CRSS(sub cube) of the gamma + gamma' alloys also reflected the compositional dependence of the gamma'/gamma mismatch, but bore no similarity to that of CRSS(sub cube) for gamma' alloys since it is controlled by the gamma matrix. The ratio of CRSS(sub cube)/CRSS(sub oct) was decreased by all alloying elements except Co, which increased the ratio. The decrease in CRSS(sub cube)/CRSS(sub oct) was related to the degree in which elements partition to the gamma' rather than the gamma phase.

Gamma-gamma coincidence performance of LaBr 3:Ce scintillation detectors vs HPGe detectors in high count-rate scenarios

DOE PAGES

Drescher, A.; Yoho, M.; Landsberger, S.; ...

2017-01-15

In this study, a radiation detection system consisting of two cerium doped lanthanum bromide (LaBr 3:Ce) scintillation detectors in a gamma-gamma coincidence configuration has been used to demonstrate the advantages that coincident detection provides relative to a single detector, and the advantages that LaBr 3:Ce detectors provide relative to high purity germanium (HPGe) detectors. Signal to noise ratios of select photopeak pairs for these detectors have been compared to high-purity germanium (HPGe) detectors in both single and coincident detector configurations in order to quantify the performance of each detector configuration. The efficiency and energy resolution of LaBr 3:Ce detectors havemore » been determined and compared to HPGe detectors. Coincident gamma-ray pairs from the radionuclides 152Eu and 133Ba have been identified in a sample that is dominated by 137Cs. Gamma-gamma coincidence successfully reduced the Compton continuum from the large 137Cs peak, revealed several coincident gamma energies characteristic of these nuclides, and improved the signal-to-noise ratio relative to single detector measurements. LaBr 3:Ce detectors performed at count rates multiple times higher than can be achieved with HPGe detectors. The standard background spectrum consisting of peaks associated with transitions within the LaBr 3:Ce crystal has also been significantly reduced. Finally, it is shown that LaBr 3:Ce detectors have the unique capability to perform gamma-gamma coincidence measurements in very high count rate scenarios, which can potentially benefit nuclear safeguards in situ measurements of spent nuclear fuel.« less

Gamma-gamma coincidence performance of LaBr 3:Ce scintillation detectors vs HPGe detectors in high count-rate scenarios

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

Drescher, A.; Yoho, M.; Landsberger, S.

In this study, a radiation detection system consisting of two cerium doped lanthanum bromide (LaBr 3:Ce) scintillation detectors in a gamma-gamma coincidence configuration has been used to demonstrate the advantages that coincident detection provides relative to a single detector, and the advantages that LaBr 3:Ce detectors provide relative to high purity germanium (HPGe) detectors. Signal to noise ratios of select photopeak pairs for these detectors have been compared to high-purity germanium (HPGe) detectors in both single and coincident detector configurations in order to quantify the performance of each detector configuration. The efficiency and energy resolution of LaBr 3:Ce detectors havemore » been determined and compared to HPGe detectors. Coincident gamma-ray pairs from the radionuclides 152Eu and 133Ba have been identified in a sample that is dominated by 137Cs. Gamma-gamma coincidence successfully reduced the Compton continuum from the large 137Cs peak, revealed several coincident gamma energies characteristic of these nuclides, and improved the signal-to-noise ratio relative to single detector measurements. LaBr 3:Ce detectors performed at count rates multiple times higher than can be achieved with HPGe detectors. The standard background spectrum consisting of peaks associated with transitions within the LaBr 3:Ce crystal has also been significantly reduced. Finally, it is shown that LaBr 3:Ce detectors have the unique capability to perform gamma-gamma coincidence measurements in very high count rate scenarios, which can potentially benefit nuclear safeguards in situ measurements of spent nuclear fuel.« less

Identification of the low affinity receptor for immunoglobulin E on mouse mast cells and macrophages as Fc gamma RII and Fc gamma RIII

PubMed Central

1992-01-01

In addition to their well characterized high affinity immunoglobulin E (IgE) receptors (Fc epsilon RI) mast cells have long been suspected to express undefined Fc receptors capable of binding IgE with low affinity. In this paper, we show that Fc gamma RII and Fc gamma RIII, but not Mac-2, on mouse mast cells and macrophages bind IgE-immune complexes. This binding is efficiently competed by 2.4G2, a monoclonal antibody against the extracellular homologous region of both Fc gamma RII and Fc gamma RIII. Furthermore, IgE-immune complexes bind specifically to Fc gamma RII or Fc gamma RIII transfected into COS-7 cells. The association constants of IgE binding estimated from competition experiments are about 3.1 x 10(5) M-1 for Fc gamma RII, and 4.8 x 10(5) M-1 for Fc gamma RIII. Engagement of Fc gamma RII and Fc gamma RIII with IgE-immune complexes (after blocking access to Fc epsilon RI) or with IgG-immune complexes triggers C57.1 mouse mast cells to release serotonin. This release is inhibited by 2.4G2, and at maximum, reaches 30-40% of the intracellular content, about half of the maximal release (60-80%) obtained after Fc epsilon RI engagement. These data demonstrate that mouse Fc gamma RII and Fc gamma RIII are not isotype specific, and that the binding of IgE-immune complexes to these receptors induces cell activation. PMID:1386873

Experimental review of light quark spectroscopy from e/sup +/e/sup -/ production and. gamma gamma. collisions

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

Toki, W.H.

1987-07-01

This is an experimental review of light quark spectroscopy from e/sup +/e/sup -/ production and ..gamma gamma.. collision results presented at the 2nd International Conference on Hadron Spectroscopy at KEK, Japan. The recent results in ..gamma gamma.. production have evidence for the J/sup PC/ = 1/sup + +/, E/f/sub 1/(1420) and D/f/sub 1/(1285), mesons from the TPC and Mark II collaborations and upper limits for pseudoscalar resonances from the Crystal Ball collaboration. The results in J/psi reactions include D/f/sub 1/(1285) meson production in radiative decays and a complete measurement of the hadronic decays into pseudoscalar-vector pairs from the DM2 collaborationmore » and evidence for phi phi production in radiative decays and a study of the iota line shape from the Mark III collaboration. A short review of simple theoretical ideas is presented.« less

Fluorescence-Assisted Gamma Spectrometry for Surface Contamination Analysis

NASA Astrophysics Data System (ADS)

Ihantola, Sakari; Sand, Johan; Perajarvi, Kari; Toivonen, Juha; Toivonen, Harri

2013-02-01

A fluorescence-based alpha-gamma coincidence spectrometry approach has been developed for the analysis of alpha-emitting radionuclides. The thermalization of alpha particles in air produces UV light, which in turn can be detected over long distances. The simultaneous detection of UV and gamma photons allows detailed gamma analyses of a single spot of interest even in highly active surroundings. Alpha particles can also be detected indirectly from samples inside sealed plastic bags, which minimizes the risk of cross-contamination. The position-sensitive alpha-UV-gamma coincidence technique reveals the presence of alpha emitters and identifies the nuclides ten times faster than conventional gamma spectrometry.

Absence of Fc epsilonRI alpha chain results in upregulation of Fc gammaRIII-dependent mast cell degranulation and anaphylaxis. Evidence of competition between Fc epsilonRI and Fc gammaRIII for limiting amounts of FcR beta and gamma chains.

PubMed Central

Dombrowicz, D; Flamand, V; Miyajima, I; Ravetch, J V; Galli, S J; Kinet, J P

1997-01-01

In mouse mast cells, both Fc epsilonRI and Fc gammaRIII are alpha beta gamma2 tetrameric complexes in which different alpha chains confer IgE or IgG ligand recognition while the signaling FcR beta and gamma chains are identical. We used primarily noninvasive techniques (changes in body temperature, dye extravasation) to assess systemic anaphylactic responses in nonanesthetized wild-type, Fc epsilonRI alpha chain -/- and FcR gamma chain -/- mice. We confirm that systemic anaphylaxis in mice can be mediated largely through IgG1 and Fc gammaRIII and we provide direct evidence that these responses reflect activation of Fc gammaRIII rather than Fc gammaRI. Furthermore, we show that Fc gammaRIII-dependent responses are more intense in normal than in congenic mast cell-deficient KitW/KitW-v mice, indicating that Fc gammaRIII responses have mast cell-dependent and -independent components. Finally, we demonstrate that the upregulation of cell surface expression of Fc gammaRIII seen in Fc epsilonRI alpha chain -/- mice corresponds to an increased association of Fc gammaRIII alpha chains with FcR beta and gamma chains and is associated with enhanced Fc gammaRIII-dependent mast cell degranulation and systemic anaphylactic responses. Therefore, the phenotype of the Fc epsilonRI alpha chain -/- mice suggests that expression of Fc epsilonRI and Fc gammaRIII is limited by availability of the FcR beta and gamma chains and that, in normal mice, changes in the expression of one receptor (Fc epsilonRI) may influence the expression of functional responses dependent on the other (Fc gammaRIII). PMID:9062349

Gamma-ray Astrophysics with AGILE

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

Longo, Francesco; Tavani, M.; Barbiellini, G.

2007-07-12

AGILE will explore the gamma-ray Universe with a very innovative instrument combining for the first time a gamma-ray imager and a hard X-ray imager. AGILE will be operational in spring 2007 and it will provide crucial data for the study of Active Galactic Nuclei, Gamma-Ray Bursts, unidentified gamma-ray sources. Galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. The AGILE instrument is designed to simultaneously detect and image photons in the 30 MeV - 50 GeV and 15 - 45 keV energy bands with excellent imaging and timing capabilities, and a large field of view coveringmore » {approx} 1/5 of the entire sky at energies above 30 MeV. A CsI calorimeter is capable of GRB triggering in the energy band 0.3-50 MeV AGILE is now (March 2007) undergoing launcher integration and testing. The PLSV launch is planned in spring 2007. AGILE is then foreseen to be fully operational during the summer of 2007.« less

Comparison of penumbra regions produced by ancient Gamma knife model C and Gamma ART 6000 using Monte Carlo MCNP6 simulation.

PubMed

Banaee, Nooshin; Asgari, Sepideh; Nedaie, Hassan Ali

2018-07-01

The accuracy of penumbral measurements in radiotherapy is pivotal because dose planning computers require accurate data to adequately modeling the beams, which in turn are used to calculate patient dose distributions. Gamma knife is a non-invasive intracranial technique based on principles of the Leksell stereotactic system for open deep brain surgeries, invented and developed by Professor Lars Leksell. The aim of this study is to compare the penumbra widths of Leksell Gamma Knife model C and Gamma ART 6000. Initially, the structure of both systems were simulated by using Monte Carlo MCNP6 code and after validating the accuracy of simulation, beam profiles of different collimators were plotted. MCNP6 beam profile calculations showed that the penumbra values of Leksell Gamma knife model C and Gamma ART 6000 for 18, 14, 8 and 4 mm collimators are 9.7, 7.9, 4.3, 2.6 and 8.2, 6.9, 3.6, 2.4, respectively. The results of this study showed that since Gamma ART 6000 has larger solid angle in comparison with Gamma Knife model C, it produces better beam profile penumbras than Gamma Knife model C in the direct plane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pulsed high-energy gamma rays from PSR 1055-52

NASA Technical Reports Server (NTRS)

Fierro, J. M.; Bertsch, D. L.; Brazier, K. T.; Chiang, J.; D'Amico, N.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Johnston, S.; Kanbach, G.

1993-01-01

The Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory has detected a high-energy gamma-ray source at a position coincident with that of the radio pulsar PSR 1055-52. Analysis of the EGRET data at the radio pulsar period of 197 ms has revealed pulsed gamma-radiation at energies above 300 MeV, making PSR 1055-52 the fifth detected high-energy gamma-ray pulsar. The pulsed radiation from PSR 1055-52 has a very hard photon spectral index of -1.18 +/- 0.16 and a high efficiency for converting its rotational energy into gamma-rays. No unpulsed emission was observed.

Resistance of a directionally solidified gamma/gamma prime-delta eutectic alloy to recrystallization. [Ni-base alloy

NASA Technical Reports Server (NTRS)

Tewari, S. N.; Scheuermann, C. M.; Andrews, C. W.

1976-01-01

A lamellar nickel-base directionally-solidified eutectic gamma/gamma prime-delta alloy has potential as an advanced gas turbine blade material. The microstructural stability of this alloy was investigated. Specimens were plastically deformed by uniform compression or Brinell indentation, then annealed between 750 and 1120 C. Microstructural changes observed after annealing included gamma prime coarsening, pinch-off and spheroidization of delta lamellae, and appearance of an unidentified blocky phase in surface layers. All but the first of these was localized in severely deformed regions, suggesting that microstructural instability may not be a serious problem in the use of this alloy.

Thermal-neutron capture gamma-rays. Volume 1

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

Tuli, J.K.

1997-05-01

The energy and photon intensity of gamma rays as seen in thermal-neutron capture are presented in ascending order of gamma energy. All those gamma-rays with intensity of {ge} 2% of the strongest transition are included. The two strongest transitions seen for the target nuclide are indicated in each case. Where the target nuclide mass number is indicated as nat the natural target was used. The gamma energies given are in keV. The gamma intensities given are relative to 100 for the strongest transition. All data for A > 44 are taken from Evaluated Nuclear Structure Data File (4/97), a computermore » file of evaluated nuclear structure data maintained by the National Nuclear Data Center, Brookhaven National Laboratory, on behalf of the Nuclear Structure and Decay and Decay Data network, coordinated by the International Atomic Energy Agency, Vienna. These data are published in Nuclear Data Sheets, Academic Press, San Diego, CA. The data for A {le} 44 is taken from ``Prompt Gamma Rays from Thermal-Neutron Capture,`` M.A. Lone, R.A. Leavitt, D.A. Harrison, Atomic Data and Nuclear Data Tables 26, 511 (1981).« less

The supernova-gamma-ray burst-jet connection.

PubMed

Hjorth, Jens

2013-06-13

The observed association between supernovae and gamma-ray bursts represents a cornerstone in our understanding of the nature of gamma-ray bursts. The collapsar model provides a theoretical framework for this connection. A key element is the launch of a bipolar jet (seen as a gamma-ray burst). The resulting hot cocoon disrupts the star, whereas the (56)Ni produced gives rise to radioactive heating of the ejecta, seen as a supernova. In this discussion paper, I summarize the observational status of the supernova-gamma-ray burst connection in the context of the 'engine' picture of jet-driven supernovae and highlight SN 2012bz/GRB 120422A--with its luminous supernova but intermediate high-energy luminosity--as a possible transition object between low-luminosity and jet gamma-ray bursts. The jet channel for supernova explosions may provide new insights into supernova explosions in general.

Search for medium-energy gamma-ray pulsars

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

Sweeney, W.E. Jr.

1987-01-01

Results are presented from a search for pulsed gamma rays from four radio pulsars, chosen for their interest to gamma-ray astronomers in previous studies. The data set used for the search consists of gamma-ray events at energies of 1-30 MeV, detected during a 40-hour balloon flight of the UCR double Compton scatter telescope launched at the National Scientific Balloon Facility in Palestine, Texas, USA on September 30, 1978. No statistically significant signals were detected from any of the pulsars. Three sigma upper limits to pulsed 1-30 MeV gamma ray flux from PSR 0950+08, PSR 1822+09, PSR 1929+10, and PSR 1953+29more » are presented. Two complete exposures to PSR 0950+08 were obtained. The reported tentative detection of 1-20 MeV gamma rays from PSR 0950+08 is not confirmed.« less

Self-induced intracerebral gamma oscillations in the human cortex.

PubMed

Corlier, Juliana; Rimsky-Robert, Daphné; Valderrama, Mario; Lehongre, Katia; Adam, Claude; Clémenceau, Stéphane; Charpier, Stéphane; Bastin, Julien; Kahane, Philippe; Lachaux, Jean-Philippe; Navarro, Vincent; Le Van Quyen, Michel

2016-12-01

Gamma oscillations play a pivotal role in multiple cognitive functions. They enable coordinated activity and communication of local assemblies, while abnormalities in gamma oscillations exist in different neurological and psychiatric diseases. Thus, a specific rectification of gamma synchronization could potentially compensate the deficits in pathological conditions. Previous experiments have shown that animals can voluntarily modulate their gamma power through operant conditioning. Using a closed-loop experimental setup, we show in six intracerebrally recorded epileptic patients undergoing presurgical evaluation that intracerebral power spectrum can be increased in the gamma frequency range (30-80 Hz) at different fronto-temporal cortical sites in human subjects. Successful gamma training was accompanied by increased gamma power at other cortical locations and progressively enhanced cross-frequency coupling between gamma and slow oscillations (3-12 Hz). Finally, using microelectrode targets in two subjects, we report that upregulation of gamma activities is possible also in spatial micro-domains, without the spread to macroelectrodes. Overall, our findings indicate that intracerebral gamma modulation can be achieved rapidly, beyond the motor system and with high spatial specificity, when using micro targets. These results are especially significant because they pave the way for use of high-resolution therapeutic approaches for future clinical applications. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A New View of the High Energy Gamma-Ray Sky with the Ferrni Gamma-Ray Space Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2009-01-01

Following its launch in June 2008, high energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have opened a new and important window on a wide variety of phenomena, including pulsars, black holes and active galactic nuclei, gamma-ray bursts, supernova remnants and the origin of cosmic rays, and searches for hypothetical new phenomena such as super symmetric dark matter annihilations. In this talk I will describe the current status of the Fermi observatory and review the science highlights from the first year of observations.

Analogues of methotrexate and aminopterin with gamma-methylene and gamma-cyano substitution of the glutamate side chain: synthesis and in vitro biological activity.

PubMed

Rosowsky, A; Bader, H; Freisheim, J H

1991-01-01

Analogues of methotrexate (MTX) and aminopterin (AMT) modified at the gamma-position of the glutamate side chain were synthesized and evaluated as dihydrofolate reductase (DHFR) inhibitors and tumor cell growth inhibitors. Condesations of 4-amino-4-deoxy-N10-methylpteroic acid (mAPA) with dimethyl DL-4-methyleneglutamate in the presence of diethyl phosphorocyanidate (DEPC) followed by alkaline hydrolysis yielded N-(4-amino-4-deoxy-N10-methylpteroyl)-DL-4-methyleneglutamic acid (gamma-methyleneMTX). Condensation of 4-amino-4-deoxy-N10-formylpteroic acid (fAPA) with dimethyl-DL-4-methyleneglutamate by the mixed carboxylic-carbonic anhydride method yielded N-4-amino-4-deoxypteroyl)-DL-4-methyleneglutamic acid (gamma-methyleneAMT). Also prepared via DEPC coupling was a mixture of the four possible diastereomers of N-(4-amino-4-deoxy-N10-methylpteroyl)-4-cyanoglutamic acid (gamma-cyanoMTX). The requisite intermediate gamma-tert-butyl alpha-methyl 4-cyanoglutamate, as a DL-threo/DL-erythro mixture, was prepared from methyl N alpha-Boc-O-tosyl-L-serinate by reaction with sodium tert-butyl cyanoacetate followed by mild trifluoroacetic treatment to selectively remove the Boc group. The gamma-methylene derivatives of MTX and AMT are attractive because of their potential to act as Michael acceptors within the DHFR active site. gamma-CyanoMTX may be viewed as a congener of the nonpolyglutamated MTX analogue gamma-fluoroMTX. In vitro bioassay data for the gamma-methylene and gamma-cyano compounds support the idea that the active site of DHFR, already known for its ability to tolerate modification of the gamma-carboxyl group of MTX and AMT, can likewise accommodate substitution on the gamma-carbon itself.

Effects of Correlated and Uncorrelated Gamma Rays on Neutron Multiplicity Counting

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

Cowles, Christian C.; Behling, Richard S.; Imel, George R.

Neutron multiplicity counting relies on time correlation between neutron events to assay the fissile mass, (α,n) to spontaneous fission neutron ratio, and neutron self-multiplication of samples. Gamma-ray sensitive neutron multiplicity counters may misidentify gamma rays as neutrons and therefore miscalculate sample characteristics. Time correlated and uncorrelated gamma-ray-like signals were added into gamma-ray free neutron multiplicity counter data to examine the effects of gamma ray signals being misidentified as neutron signals on assaying sample characteristics. Multiplicity counter measurements with and without gamma-ray-like signals were compared to determine the assay error associated with gamma-ray-like signals at various gamma-ray and neutron rates. Correlatedmore » and uncorrelated gamma-ray signals each produced consistent but different measurement errors. Correlated gamma-ray signals most strongly led to fissile mass overestimates, whereas uncorrelated gamma-ray signals most strongly lead to (α,n) neutron overestimates. Gamma-ray sensitive neutron multiplicity counters may be able to account for the effects of gamma-rays on measurements to mitigate measurement uncertainties.« less

Neurofeedback training of gamma band oscillations improves perceptual processing.

PubMed

Salari, Neda; Büchel, Christian; Rose, Michael

2014-10-01

In this study, a noninvasive electroencephalography-based neurofeedback method is applied to train volunteers to deliberately increase gamma band oscillations (40 Hz) in the visual cortex. Gamma band oscillations in the visual cortex play a functional role in perceptual processing. In a previous study, we were able to demonstrate that gamma band oscillations prior to stimulus presentation have a significant influence on perceptual processing of visual stimuli. In the present study, we aimed to investigate longer lasting effects of gamma band neurofeedback training on perceptual processing. For this purpose, a feedback group was trained to modulate oscillations in the gamma band, while a control group participated in a task with an identical design setting but without gamma band feedback. Before and after training, both groups participated in a perceptual object detection task and a spatial attention task. Our results clearly revealed that only the feedback group but not the control group exhibited a visual processing advantage and an increase in oscillatory gamma band activity in the pre-stimulus period of the processing of the visual object stimuli after the neurofeedback training. Results of the spatial attention task showed no difference between the groups, which underlines the specific role of gamma band oscillations for perceptual processing. In summary, our results show that modulation of gamma band activity selectively affects perceptual processing and therefore supports the relevant role of gamma band activity for this specific process. Furthermore, our results demonstrate the eligibility of gamma band oscillations as a valuable tool for neurofeedback applications.

Gamma-ray lens development status for a European gamma-ray imager

NASA Astrophysics Data System (ADS)

Frontera, F.; Pisa, A.; Carassiti, V.; Evangelisti, F.; Loffredo, G.; Pellicciotta, D.; Andersen, K. H.; Courtois, P.; Amati, L.; Caroli, E.; Franceschini, T.; Landini, G.; Silvestri, S.; Stephen, J. B.

2006-06-01

A breakthrough in the sensitivity level of the hard X-/gamma-ray telescopes, which today are based on detectors that view the sky through (or not) coded masks, is expected when focusing optics will be available also in this energy range. Focusing techniques are now in an advanced stage of development. To date the most efficient technique to focus hard X-rays with energies above 100 keV appears to be the Bragg diffraction from crystals in transmission configuration (Laue lenses). Crystals with mosaic structure appear to be the most suitable to build a Laue lens with a broad passband, even though other alternative structures are being investigated. The goal of our project is the development of a broad band focusing telescope based on gamma-ray lenses for the study of the continuum emission of celestial sources from 60 keV up to >600 keV. We will report details of our project, its development status and results of our assessment study of a lens configuration for the European Gamma Ray Imager (GRI) mission now under study for the ESA plan Cosmic Vision 2015-2025.

X-ray and gamma ray astronomy detectors

NASA Technical Reports Server (NTRS)

Decher, Rudolf; Ramsey, Brian D.; Austin, Robert

1994-01-01

X-ray and gamma ray astronomy was made possible by the advent of space flight. Discovery and early observations of celestial x-rays and gamma rays, dating back almost 40 years, were first done with high altitude rockets, followed by Earth-orbiting satellites> once it became possible to carry detectors above the Earth's atmosphere, a new view of the universe in the high-energy part of the electromagnetic spectrum evolved. Many of the detector concepts used for x-ray and gamma ray astronomy were derived from radiation measuring instruments used in atomic physics, nuclear physics, and other fields. However, these instruments, when used in x-ray and gamma ray astronomy, have to meet unique and demanding requirements related to their operation in space and the need to detect and measure extremely weak radiation fluxes from celestial x-ray and gamma ray sources. Their design for x-ray and gamma ray astronomy has, therefore, become a rather specialized and rapidly advancing field in which improved sensitivity, higher energy and spatial resolution, wider spectral coverage, and enhanced imaging capabilities are all sought. This text is intended as an introduction to x-ray and gamma ray astronomy instruments. It provides an overview of detector design and technology and is aimed at scientists, engineers, and technical personnel and managers associated with this field. The discussion is limited to basic principles and design concepts and provides examples of applications in past, present, and future space flight missions.

The Gamma-Ray Albedo of the Moon

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

Moskalenko, I.V.; /Stanford U., HEPL /KIPAC, Menlo Park; Porter, T.A.

2008-03-25

We use the GEANT4 Monte Carlo framework to calculate the {gamma}-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of {gamma}-rays from the Moon is very steep with an effective cutoff around 3-4 GeV (600 MeV for the inner part of the Moon disk) and exhibits a narrow pion-decay line at 67.5 MeV, perhaps unique in astrophysics. Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalization; this makesmore » it a useful 'standard candle' for {gamma}-ray telescopes. The steep albedo spectrum also provides a unique opportunity for energy calibration of {gamma}-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). Since the albedo flux depends on the incident CR spectrum which changes over the solar cycle, it is possible to monitor the CR spectrum using the albedo {gamma}-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo {gamma}-rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the LAT to monitor the CR spectrum near the Earth beyond the lifetime of the PAMELA.« less

The Gamma-ray Albedo of the Moon

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

Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.

2007-09-28

We use the GEANT4 Monte Carlo framework to calculate the {gamma}-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of {gamma}-rays from the Moon is very steep with an effective cutoff around 3-4 GeV (600 MeV for the inner part of the Moon disk) and exhibits a narrow pion-decay line at 67.5 MeV, perhaps unique in astrophysics. Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalization; this makesmore » it a useful 'standard candle' for {gamma}-ray telescopes. The steep albedo spectrum also provides a unique opportunity for energy calibration of {gamma}-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). Since the albedo flux depends on the incident CR spectrum which changes over the solar cycle, it is possible to monitor the CR spectrum using the albedo {gamma}-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo {gamma}-rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the LAT to monitor the CR spectrum near the Earth beyond the lifetime of the PAMELA.« less

The gamma knife in ophthalmology. Part One--Uveal melanoma.

PubMed

Wygledowska-Promieńska, Dorota; Jurys, Małgorzata; Wilczyński, Tomasz; Drzyzga, Łukasz

2014-01-01

The Gamma Knife was designed by Lars Leksell in the early 1950's. It gave rise to a new discipline of medicine--stereotactic radiosurgery. Primarily dedicated to neurosurgery, the Gamma Knife has become an alternative, widely used surgery technique. According to Elekta's statistics, approximately 60,000 people are treated with Leksell Gamma Knife every year and it is the most extensively studied stereotactic radiosurgery system in the world. The Leksell Gamma Knife can also be used in ophthalmology. The gamma ray beam concentration enables effective treatment of uveal melanoma, choroidal hemangioma, orbital tumors or even choroidal neovascularization. The virtue of Leksell Gamma Knife is its extreme precision, non-invasiveness and the possibility of outpatient treatment, which significantly reduces costs and diminishes post-operative complications. Innovative solutions shorten a single session to a minimum, which is very comfortable and safe for both staff and patients. Advantages and possible side effects of gamma knife radiosurgery are well-documented in the professional literature. The objective of this review is to present the recognized applications of Leksell Gamma Knife in ophthalmology.

The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope

ScienceCinema

Isabelle Grenier

2018-04-17

The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008.  In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

Terrestrial gamma-ray flashes

NASA Astrophysics Data System (ADS)

Marisaldi, Martino; Fuschino, Fabio; Labanti, Claudio; Tavani, Marco; Argan, Andrea; Del Monte, Ettore; Longo, Francesco; Barbiellini, Guido; Giuliani, Andrea; Trois, Alessio; Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo

2013-08-01

Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models.

Gamma ray constraints on the Galactic supernova rate

NASA Technical Reports Server (NTRS)

Hartmann, D.; The, L.-S.; Clayton, Donald D.; Leising, M.; Mathews, G.; Woosley, S. E.

1991-01-01

We perform Monte Carlo simulations of the expected gamma ray signatures of Galactic supernovae of all types to estimate the significance of the lack of a gamma ray signal due to supernovae occurring during the last millenium. Using recent estimates of the nuclear yields, we determine mean Galactic supernova rates consistent with the historic supernova record and the gamma ray limits. Another objective of these calculations of Galactic supernova histories is their application to surveys of diffuse Galactic gamma ray line emission.

Gamma ray constraints on the galactic supernova rate

NASA Technical Reports Server (NTRS)

Hartmann, D.; The, L.-S.; Clayton, D. D.; Leising, M.; Mathews, G.; Woosley, S. E.

1992-01-01

Monte Carlo simulations of the expected gamma-ray signatures of galactic supernovae of all types are performed in order to estimate the significance of the lack of a gamma-ray signal due to supernovae occurring during the last millenium. Using recent estimates of nuclear yields, we determine galactic supernova rates consistent with the historic supernova record and the gamma-ray limits. Another objective of these calculations of galactic supernova histories is their application to surveys of diffuse galactic gamma-ray line emission.

Hepatobiliary magnetic resonance imaging in patients with liver disease: correlation of liver enhancement with biochemical liver function tests.

PubMed

Kukuk, Guido M; Schaefer, Stephanie G; Fimmers, Rolf; Hadizadeh, Dariusch R; Ezziddin, Samer; Spengler, Ulrich; Schild, Hans H; Willinek, Winfried A

2014-10-01

To evaluate hepatobiliary magnetic resonance imaging (MRI) using Gd-EOB-DTPA in relation to various liver function tests in patients with liver disorders. Fifty-one patients with liver disease underwent Gd-EOB-DTPA-enhanced liver MRI. Based on region-of-interest (ROI) analysis, liver signal intensity was calculated using the spleen as reference tissue. Liver-spleen contrast ratio (LSCR) and relative liver enhancement (RLE) were calculated. Serum levels of total bilirubin, gamma glutamyl transpeptidase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), serum albumin level (AL), prothrombin time (PT), creatinine (CR) as well as international normalised ratio (INR) and model for end-stage liver disease (MELD) score were tested for correlation with LSCR and RLE. Pre-contrast LSCR values correlated with total bilirubin (r = -0.39; p = 0.005), GGT (r = -0.37; p = 0.009), AST (r = -0.38; p = 0.013), ALT (r = -0.29; p = 0.046), PT (r = 0.52; p < 0.001), GLDH (r = -0.55; p = 0.044), INR (r = -0.42; p = 0.003), and MELD Score (r = -0.53; p < 0.001). After administration of Gd-EOB-DTPA bilirubin (r = -0.45; p = 0.001), GGT (r = -0.40; p = 0.004), PT (r = 0.54; p < 0.001), AST (r = -0.46; p = 0.002), ALT (r = -0.31; p = 0.030), INR (r = -0.45; p = 0.001) and MELD Score (r = -0.56; p < 0.001) significantly correlated with LSCR. RLE correlated with bilirubin (r = -0.40; p = 0.004), AST (r = -0.38; p = 0.013), PT (r = 0.42; p = 0.003), GGT (r = -0.33; p = 0.020), INR (r = -0.36; p = 0.011) and MELD Score (r = -0.43; p = 0.003). Liver-spleen contrast ratio and relative liver enhancement using Gd-EOB-DTPA correlate with a number of routinely used biochemical liver function tests, suggesting that hepatobiliary MRI may serve as a

The EGRET high energy gamma ray telescope

NASA Technical Reports Server (NTRS)

Hartman, R. C.; Bertsch, D. L.; Fichtel, C. E.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.

1992-01-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (GRO) is sensitive in the energy range from about 20 MeV to about 30,000 MeV. Electron-positron pair production by incident gamma photons is utilized as the detection mechanism. The pair production occurs in tantalum foils interleaved with the layers of a digital spark chamber system; the spark chamber records the tracks of the electron and positron, allowing the reconstruction of the arrival direction of the gamma ray. If there is no signal from the charged particle anticoincidence detector which surrounds the upper part of the detector, the spark chamber array is triggered by two hodoscopes of plastic scintillators. A time of flight requirement is included to reject events moving backward through the telescope. The energy of the gamma ray is primarily determined by absorption of the energies of the electron and positron in a 20 cm deep NaI(Tl) scintillator.

The EGRET high energy gamma ray telescope

NASA Astrophysics Data System (ADS)

Hartman, R. C.; Bertsch, D. L.; Fichtel, C. E.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.; Michelson, P. F.; von Montigny, C.; Nolan, P. L.; Pinkau, K.; Rothermel, H.; Schneid, E.; Sommer, M.; Sreekumar, P.; Thompson, D. J.

1992-02-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (GRO) is sensitive in the energy range from about 20 MeV to about 30,000 MeV. Electron-positron pair production by incident gamma photons is utilized as the detection mechanism. The pair production occurs in tantalum foils interleaved with the layers of a digital spark chamber system; the spark chamber records the tracks of the electron and positron, allowing the reconstruction of the arrival direction of the gamma ray. If there is no signal from the charged particle anticoincidence detector which surrounds the upper part of the detector, the spark chamber array is triggered by two hodoscopes of plastic scintillators. A time of flight requirement is included to reject events moving backward through the telescope. The energy of the gamma ray is primarily determined by absorption of the energies of the electron and positron in a 20 cm deep NaI(Tl) scintillator.

Solar Gamma Rays Above 8 MeV

NASA Technical Reports Server (NTRS)

Crannell, C. J.; Crannell, H.; Ramaty, R.

1978-01-01

Processes which lead to the production of gamma rays with energy greater than 8 MeV in solar flares are reviewed and evaluated. Excited states produced by inelastic scattering, charge exchange, and spallation reactions in the abundant nuclear species are considered in order to identify nuclear lines which may contribute to the Gamma ray spectrum of solar flares. The flux of 15.11 MeV Gamma rays relative to the flux of 4.44 MeV Gamma rays from the de-excitation of the corresponding states in C12 is calculated for a number of assumed distributions of exciting particles. This flux ratio is a sensitive diagnostic of accelerated particle spectra. Other high energy nuclear levels are not so isolated as the 15.11 MeV state and are not expected to be so strong. The spectrum of Gamma rays from the decay of Pi dey is sensitive to the energy distribution of particles accelerated to energies greater than 100 MeV.

Gamma ray energy tracking in GRETINA

NASA Astrophysics Data System (ADS)

Lee, I. Y.

2011-10-01

The next generation of stable and exotic beam accelerators will provide physics opportunities to study nuclei farther away from the line of stability. However, these experiments will be more demanding on instrumentation performance. These come from the lower production rate for more exotic beams, worse beam impurities, and large beam velocity from the fragmentation and inverse reactions. Gamma-ray spectroscopy will be one of the most effective tools to study exotic nuclei. However, to fully exploit the physics reach provided by these new facilities, better gamma-ray detector will be needed. In the last 10 years, a new concept, gamma-ray energy tracking array, was developed. Tracking arrays will increase the detection sensitivity by factors of several hundred compared to current arrays used in nuclear physics research. Particularly, the capability of reconstructing the position of the interaction with millimeters resolution is needed to correct the Doppler broadening of gamma rays emitted from high velocity nuclei. GRETINA is a gamma-ray tracking array which uses 28 Ge crystals, each with 36 segments, to cover ¼ of the 4 π of the 4 π solid angle. The gamma ray tracking technique requires detailed pulse shape information from each of the segments. These pulses are digitized using 14-bit 100 MHz flash ADCs, and digital signal analysis algorithms implemented in the on-board FPGAs provides energy, time and selection of pulse traces. A digital trigger system, provided flexible trigger functions including a fast trigger output, and also allows complicated trigger decisions to be made up to 20 microseconds. Further analyzed, carried out in a computer cluster, determine the energy, time, and three-dimensional positions of all gamma-ray interactions in the array. This information is then utilized, together with the characteristics of Compton scattering and pair-production processes, to track the scattering sequences of the gamma rays. GRETINA construction is completed in

Gamma-Ray Astrophysics: New Insight Into the Universe

NASA Technical Reports Server (NTRS)

Fichtel, Carl E.; Trombka, Jacob I.

1997-01-01

During the 15 years that have passed since the first edition of this book was published, there has been a major increase in our knowledge of gamma-ray astronomy. Much of this advance arises from the extensive results that have been forthcoming from the Compton Gamma-Ray Observatory. There has been the discovery of a new class of gamma-ray objects, namely high-energy gamma- ray-emitting blazars, a special class of Active Galactic Nuclei, whose basic high-energy properties now seem to be understood. A much improved picture of our galaxy now exists in the frequency range of gamma rays. The question of whether cosmic rays are galactic or metagalactic now seems settled with certainty. Significant new information exists on the gamma-ray properties of neutron star pulsars, Seyfert galaxies, and gamma-ray bursts. Substantial new insight has been obtained on solar phenomena through gamma-ray observations. Hence, this seemed to be an appropriate time to write a new edition of this book to add the important scientific implications of these many new findings. The special importance of gamma-ray astrophysics had long been recognized by many physicists and astronomers, and theorists had pursued many aspects of the subject well before the experimental results began to become available. The slower development of the experimental side was not because of a lack of incentive, but due to the substantial experimental difficulties that had to be overcome. Thus, as the gamma-ray results became available in much greater number and detail, it was possible to build upon the theoretical work that already existed and to make substantial progress in the study of many of the phenomena involved. Consequently, a much better understanding of many of the astrophysical phenomena mentioned here and others is now possible. Our principal aims in writing this book are the same as they were for the first edition: to provide a text which describes the significance of gamma-ray astrophysics and to assemble

Gamma Radiation from PSR B1055-52

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Bailes, M.; Bertsch, D. L.; Cordes, J.; DAmico, N. D.; Esposito, J. A.; Finley, J.; Hartman, R. C.; Hermsen, W.; Kanbach, G.;