Gamma-glutamyl Transpeptidase Activity Research Articles

Experimental protoporphyria: effect of bile acids on liver damage induced by griseofulvin.

The effect of bile acids administration to an experimental mice model of Protoporphyria produced by griseofulvin (Gris) was investigated. The aim was to assess whether porphyrin excretion could be accelerated by bile acids treatment in an attempt to diminish liver damage induced by Gris. Liver damage markers, heme metabolism, and oxidative stress parameters were analyzed in mice treated with Gris and deoxycholic (DXA), dehydrocholic (DHA), chenodeoxycholic, or ursodeoxycholic (URSO). The administration of Gris alone increased the activities of glutathione reductase (GRed), superoxide dismutase (SOD), alkaline phosphatase (AP), gamma glutamyl transpeptidase (GGT), and glutathione-S-transferase (GST), as well as total porphyrins, glutathione (GSH), and cytochrome P450 (CYP) levels in liver. Among the bile acids studied, DXA and DHA increased PROTO IX excretion, DXA also abolished the action of Gris, reducing lipid peroxidation and hepatic GSH and CYP levels, and the activities of GGT, AP, SOD, and GST returned to control values. However, porphyrin accumulation was not prevented by URSO; instead this bile acid reduced ALA-S and the antioxidant defense enzymes system activities. In conclusion, we postulate that DXA acid would be more effective to prevent liver damage induced by Gris.

Effect of Repeated Administration of Cefquinome on Biochemical and Hematological Parameters in Buffalo Calves.

Aim:Cefquinome, a fourth generation of cephalosporins have been developed for use in animals. Similar to other species, it may also have some adverse reactions in buffalo calves at therapeutic dosage. In the present study, effect of repeated administration of cefquinome on biochemical and hematological parameters was studied in buffalo calves.Materials and Methods:Animals were divided into two groups having three animals in each group. Group 1 was kept as control and animals of Group 2 were given cefquinome at dose rate of 2 mg.kg−1 body weight by intramuscular route for continuously 7 days. Blood samples were collected daily and 3 days post treatment.Results:The values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGTP), and alkaline phosphatase (ALKP) in control animals were in the range of 127.7–148.3 IU/L,49.0–55.6 IU/L, 14.0–17.3 IU/L, and 111.0–134.3 IU/L, respectively. The repeated administration of cefquinome did not influence the plasma activities of AST, ALT, GGTP, and ALKP in treated animals. The level of blood urea nitrogen (BUN) and creatinine before treatment was 14.3 ± 0.88 mg/dl and1.70 ± 0.04 mg/dl, which significantly increased on 3rd day (21.0 ± 1.53 mg/dl) and 2nd day (2.33 ± 0.07 mg/dl), respectively. Among hematological parameters, there was significant variation in levels of hemoglobin (Hb), total erythrocyte count (TEC), erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) in treated animals. No abnormal clinical symptoms were observed in any animal.Conclusion:The results revealed that clinically, the therapy of cefquinome may be continued up to 7 days.

An algorithm that predicts the viability and the yield of human hepatocytes isolated from remnant liver pieces obtained from liver resections.

Isolated human primary hepatocytes are an essential in vitro model for basic and clinical research. For successful application as a model, isolated hepatocytes need to have a good viability and be available in sufficient yield. Therefore, this study aims to identify donor characteristics, intra-operative factors, tissue processing and cell isolation parameters that affect the viability and yield of human hepatocytes. Remnant liver pieces from tissue designated as surgical waste were collected from 1034 donors with informed consent. Human hepatocytes were isolated by a two-step collagenase perfusion technique with modifications and hepatocyte yield and viability were subsequently determined. The accompanying patient data was collected and entered into a database. Univariate analyses found that the viability and the yield of hepatocytes were affected by many of the variables examined. Multivariate analyses were then carried out to confirm the factors that have a significant relationship with the viability and the yield. It was found that the viability of hepatocytes was significantly decreased by the presence of fibrosis, liver fat and with increasing gamma-glutamyltranspeptidase activity and bilirubin content. Yield was significantly decreased by the presence of liver fat, septal fibrosis, with increasing aspartate aminotransferase activity, cold ischemia times and weight of perfused liver. However, yield was significantly increased by chemotherapy treatment. In conclusion, this study determined the variables that have a significant effect on the viability and the yield of isolated human hepatocytes. These variables have been used to generate an algorithm that can calculate projected viability and yield of isolated human hepatocytes. In this way, projected viability can be determined even before isolation of hepatocytes, so that donors that result in high viability and yield can be identified. Further, if the viability and yield of the isolated hepatocytes is lower than expected, this will highlight a methodological problem that can be addressed.

Biochemical characterization of preovulatory and cystic ovarian follicular fluid of sow

Aim: The present study was designed to biochemically characterize ovarian cyst follicular fluid of sows and to relate possible changes in relation to preovulatory ovarian follicular fluid of sows. Materials and Methods: Ovaries were collected from adult and non-pregnant slaughtered sow (Hampshire X local cross). A total of 16 pairs of ovaries were investigated, and they were classified according to their pathological and physiological status into two categories i.e. preovulatory and cystic follicle (diameter >25 mm with turbid appearance). Fluid was aspirated from the follicles and stored at −20°C prior to assaying. Follicular fluid samples were analyzed for glucose, total protein, cholesterol, triglycerides, blood urea nitrogen (BUN), urea, creatinine, uric acid. The activities of the enzymes aspartate transaminase, alanine transaminase (ALT), alkaline phosphatase (ALP), creatine kinase (CK) and gamma-glutamyl transpeptidase (GGT) were also estimated by spectrophotometric methods. The data were statistically analyzed using the SPSS software. Results: As follicles became cystic, the concentrations of glucose, cholesterol, triglyceride, total protein and albumin showed a significant (p<0.05) increased while BUN decreased significantly (p<0.05). The enzyme activities of ALT, ALP and CK increased significantly (p<0.05), but the activity of GGT significantly (p<0.05) decreased. Conclusion: Results obtained showed that there was a significant change in most of the cystic follicular fluid metabolites.

Ameliorating effect of chicory (Chichorium intybus L.) fruit extract against 4-tert-octylphenol induced liver injury and oxidative stress in male rats

The current study was carried out to elucidate the modulating effect of chicory (Cichorium intybus L.) fruit extract (CFR) against 4-tert-OP induced oxidative stress and hepatotoxicity in male rats. Rats were divided into four groups and treated for 8weeks as follow: group 1: normal control-treated (saline); group 2: chicory fruit extract-treated (100mg/kg); group 3: 4-tert-OP treated; group 4: 4-tert-OP plus chicory fruit extract. The obtained results revealed that rats which received 4-tert-OP showed a significant increase in liver TBARS and bilirubin, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (GGTP) activities. While a significant decrease in the levels of GSH, SOD, catalase recorded. On the other hand, CFR extract succeeded to modulate these observed abnormalities resulting from 4-tert-OP as indicated by the reduction of TBARS and the pronounced improvement of the investigated biochemical and antioxidant parameters. Histopathological evidence, together with observed PCNA and DNA fragmentation, supported the detrimental effect of 4-tert-OP and the ameliorating effect of CFR extract on liver toxicity. So, it could be concluded that chicory has a promising role and it worth to be considered as a natural substance for ameliorating the oxidative stress and hepatic injury induced by 4-tert-OP compound.

Role of Campylobacter jejuni gamma-glutamyl transpeptidase on epithelial cell apoptosis and lymphocyte proliferation.

BackgroundA gamma-glutamyl transpeptidase (GGT) is produced by up to 31% of strains of Campylobacter jejuni isolates. C. jejuni GGT is close to Helicobacter pylori GGT suggesting a conserved activity but unlike the latter, C. jejuni GGT has not been studied extensively. In line with the data available for H. pylori, our objectives were to purify C. jejuni GGT from the bacteria, and to evaluate its inhibitory and proapoptotic activities on epithelial cells and human lymphocytes.MethodsC. jejuni GGT was purified from culture supernatants by chromatography. After verification of the purity by using mass spectrometry of the purified enzyme, its action on two epithelial cell lines and human lymphocytes was investigated. Cell culture as well as flow cytometry experiments were developed for these purposes.ResultsThis study demonstrated that C. jejuni GGT is related to Helicobacter GGTs and inhibits the proliferation of epithelial cells with no proapoptotic activity. C. jejuni GGT also inhibits lymphocyte proliferation by causing a cell cycle arrest in the G0/G1 phase. These effects are abolished in the presence of a specific pharmacological inhibitor of GGT.ConclusionC. jejuni GGT activity is comparable to that of other Epsilonproteobacteria GGTs and more generally to Helicobacter bilis (inhibition of epithelial cell and lymphocyte proliferation, however with no proapoptotic activity). It could therefore be considered as a pathogenicity factor and promote, via the inhibition of lymphocyte proliferation, the persistence of the bacteria in the host. These observations are consistent with a role of this enzyme in the pathophysiology of chronic infections associated with C. jejuni.

MYO5B and bile salt export pump contribute to cholestatic liver disorder in microvillous inclusion disease

Microvillous inclusion disease (MVID) is a congenital disorder of the enterocyte related to mutations in the MYO5B gene, leading to intractable diarrhea often necessitating intestinal transplantation (ITx). Among our cohort of 28 MVID patients, 8 developed a cholestatic liver disease akin to progressive familial intrahepatic cholestasis (PFIC). Our aim was to investigate the mechanisms by which MYO5B mutations affect hepatic biliary function and lead to cholestasis in MVID patients. Clinical and biological features and outcome were reviewed. Pretransplant liver biopsies were analyzed by immunostaining and electron microscopy. Cholestasis occurred before (n = 5) or after (n = 3) ITx and was characterized by intermittent jaundice, intractable pruritus, increased serum bile acid (BA) levels, and normal gamma-glutamyl transpeptidase activity. Liver histology showed canalicular cholestasis, mild-to-moderate fibrosis, and ultrastructural abnormalities of bile canaliculi. Portal fibrosis progressed in 5 patients. No mutation in ABCB11/BSEP or ATP8B1/FIC1 genes were identified. Immunohistochemical studies demonstrated abnormal cytoplasmic distribution of MYO5B, RAB11A, and BSEP in hepatocytes. Interruption of enterohepatic BA cycling after partial external biliary diversion or graft removal proved the most effective to ensure long-term remission. MVID patients are at risk of developing a PFIC-like liver disease that may hamper outcome after ITx. Our results suggest that cholestasis in MVID patients results from (1) impairment of the MYO5B/RAB11A apical recycling endosome pathway in hepatocytes, (2) altered targeting of BSEP to the canalicular membrane, and (3) increased ileal BA absorption. Because cholestasis worsens after ITx, indication of a combined liver ITx should be discussed in MVID patients with severe cholestasis. Future studies will need to address more specifically the effect of MYO5B dysfunction in BA homeostasis.

An integrated approach combining chemical analysis and an in vivo bioassay to assess the estrogenic potency of a municipal solid waste landfill leachate in Qingdao.

Various adverse effects related to landfill leachate have made leachates an important issue in past decades, and it has been demonstrated that landfill leachate is an important source of environmental estrogens. In this study, we employed chemical analysis of some already evaluated estrogenic substances, in combination with a bioassay using several specific biomarkers (e.g., plasma vitellogenin and sex steroids, enzyme activity of gonad gamma-glutamyl transpeptidase, and gonadosomatic index) to evaluate the estrogenic activities in outlets from different stages of the leachate treatment process. The results indicated that 5 environmental estrogens (4-t-octylphenol, bisphenol A, di-ethyl phthalate, di-n-butyl phthalate, and diethylhexyl phthalate) were detected by a gas chromatography-mass spectrometry, and the concentrations in leachate samples were 6153 ng/L, 3642 ng/L, 2139 ng/L, 5900 ng/L, and 9422 ng/L, respectively. Leachate (1∶200 diluted) induced the synthesis of plasma vitellogenin and led to decreased enzyme activity of gonad gamma-glutamyl transpeptidase and gonadosomatic index in male goldfish (Carassius auratus) after a 28-day exposure, while increased circulating 17β-estradiol level was also observed in males exposed to treated effluent. Although the target EEs were partially removed with removal rates varying from 87.2% to 99.77% by the “membrane bioreactor+reverse osmosis+aeration zeolite biofilter” treatment process, the treated effluent is still estrogenic to fish. The method combined chemical techniques with the responses of test organisms allowing us to identify the group of estrogen-like chemicals so that we were able to evaluate the overall estrogenic effects of a complex mixture, avoiding false negative assessments.

Potentiation of cisplatin-induced nephrotoxicity by repeated exposure to diesel exhaust particles: An experimental study in rats.

Several epidemiological and clinical studies have shown that exposure to particulate air pollution is associated with increases in morbidity and mortality, and this is more evident in patients with renal diseases. However, the basis of the possible exacerbating effect of particulate air pollution on animal model of renal injury has received scant attention. Here, we assessed the effect of repeated exposure to diesel exhaust particles (DEP) on cisplatin (CP)-induced nephrotoxicity in rats. DEP (0.5 m/kg) was intratracheally (i.t.) instilled every second day for eight days (a total of five exposures). CP, 6 mg/kg was given 1 h before the third exposure to DEP. Two days following the last exposure to either DEP or saline (control), various renal endpoints were measured. Water intake, urine volume, and relative kidney weight were significantly increased in CP + DEP versus DEP and CP + saline versus saline. Plasma creatinine increased and creatinine clearance decreased in CP + DEP versus DEP and CP + saline versus saline. Interestingly, blood urea nitrogen, albumin concentrations, and gamma-glutamyl transpeptidase (GGT) activity in urine were significantly increased in DEP + CP compared with either DEP or saline + CP. The combination of DEP and CP enhanced kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, 8-isoprostane and total nitric oxide in the kidney compared with either saline + CP or DEP. Similarly, systolic blood pressure was increased in CP + DEP versus CP + saline or DEP. The renal tubular necrosis observed in kidneys of CP-treated rats was aggravated by the combination of CP + DEP. We conclude that repeated exposure to DEP potentiated CP-induced nephrotoxicity. Our data provide experimental evidence that patients with kidney injury could be at higher risk than the general population.

Oral isotretinoin therapy of acne patients decreases serum paraoxonase-1 activity through increasing oxidative stress

Objectives: There are only a few earlier studies suggesting relationship between isotretinoin treatment and oxidative stress however, their results are conflicting. Therefore we aimed to concretize the influence of isotretinoin treatment on oxidant/antioxidant status together with paraoxonase-1 (PON1) activity for the first time. Methods: The study was performed on serum samples obtained from 35 acne vulgaris patients before and after three months of isotretinoin treatment. PON1 activity, total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI) and some routine biochemical parameters were monitored. Results: Dramatically decreased PON1 activity (p < 0.001), increased TOS level and OSI value (p < 0.001 and p < 0.001; respectively) as well as slightly diminished TAC level were noted in posttreatment stage. Moreover significant increases were observed in lactate dehydrogenase and gamma glutamyl transpeptidase activities and levels of total cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, triglycerides, low density lipoprotein cholesterol/high density lipoprotein cholesterol ratio respectively (p < 0.05, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001 and p < 0.001) while marked decrease was seen in high density lipoprotein cholesterol (p < 0.01). Conclusion: This study revealed that decreased PON1 activity and increased oxidative stress may have a crucial role in the pathogenesis of isotretinoin’s side effects. Further studies on a large number of patients are needed to verify these results.

Glycine Stabilize the Tissue Fatty Acid Composition in an Experimental Model of Alcohol-Induced Hepatotoxicity

Background and Aim: The aim of the present study was to investigate the effect of the administration of glycine, a non-essential amino acid on tissue fatty acid composition in experimental rats.Methods: Liver cell damage was induced by the administration of ethanol (7.9 g/kg b.w.) for 30 days by intragastric intubation. Control rats were given isocaloric glucose solution. Glycine was subsequently administered at a dose of 0.6 g/kg bodyweight every day by intragastric intubation for the next 30 days.Results: Feeding alcohol significantly elevated the activities of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatases (ALP) and gamma-glutamyl transpeptidase (GGT) and altered the liver and brain fatty acid composition compared with control rats. Subsequently, glycine supplementation to alcohol-fed rats significantly lowered the activities of serum AST, ALT, ALP, GGT and normalized the liver fatty acid composition compared with untreated alcohol-fed rats.Conclusion: The present study demonstrates that oral administration of glycine confers a significant protective effect against alcohol-induced hepatotoxicity by virtue of its ability to optimize the activities of serum AST, ALT, ALP and GGT, as well as the tissue fatty acid composition. Background and Aim: The aim of the present study was to investigate the effect of the administration of glycine, a non-essential amino acid on tissue fatty acid composition in experimental rats. Methods: Liver cell damage was induced by the administration of ethanol (7.9 g/kg b.w.) for 30 days by intragastric intubation. Control rats were given isocaloric glucose solution. Glycine was subsequently administered at a dose of 0.6 g/kg bodyweight every day by intragastric intubation for the next 30 days. Results: Feeding alcohol significantly elevated the activities of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatases (ALP) and gamma-glutamyl transpeptidase (GGT) and altered the liver and brain fatty acid composition compared with control rats. Subsequently, glycine supplementation to alcohol-fed rats significantly lowered the activities of serum AST, ALT, ALP, GGT and normalized the liver fatty acid composition compared with untreated alcohol-fed rats. Conclusion: The present study demonstrates that oral administration of glycine confers a significant protective effect against alcohol-induced hepatotoxicity by virtue of its ability to optimize the activities of serum AST, ALT, ALP and GGT, as well as the tissue fatty acid composition.

An algorithm that predicts the viability and the yield of isolated human hepatocytes from surgical remnant tissues

Introduction: The liver is an organ that carries out a wide range of functions, such as detoxification, metabolism and homeostasis. As such, hepatocytes are an important model for a large variety of research questions. In particular, the use of hepatocytes is especially important in the fields of pharmacokinetics, toxicology and translational research. In order to obtain hepatocytes suitable for use as a model, hepatocytes with high viability and yield must be isolated. Therefore, this study aims to identify donor characteristics, intra-operative factors, tissue processing and cell isolation parameters that affect the viability and yield of human hepatocytes. Methods: Remnant liver pieces from tissue designated as surgical waste was collected from 1034 donors with informed consent. Corresponding data on donor characteristics, medical histories, operations, tissue processing and cell isolation parameters were collected and entered into a database. Human hepatocytes were isolated by a two-step collagenase perfusion technique with modifications. Hepatocyte yield and viability were then subsequently determined using a hemocytometer-based trypan blue exclusion assay. Univariate and multivariate analyses were carried out using Software R. Results: Univariate analyses found that the viability and the yield of hepatocytes were affected by many of the variables examined. Multivariate analyses were then carried out to confirm the factors that have a significant relationship with the viability and the yield. It was found that the viability of hepatocytes was significantly decreased by the presence of fibrosis, liver fat and with increasing gamma-glutamyltranspeptidase activity and bilirubin content. Yield was significantly decreased by the presence of liver fat, septal fibrosis, with increasing aspartate aminotransferase activity, cold ischemia times and weight of perfused liver. However, yield was significantly increased by chemotherapy treatment. Discussion: In conclusion, this study determined the variables that have a significant effect on the viability and the yield of isolated human hepatocytes. These variables have been used to generate an algorithm that can calculate projected viability and yield of isolated human hepatocytes. In this way, projected viability can be determined even before isolation of hepatocytes, so that donors that result in high viability and yield can be identified as candidates for isolating hepatocytes. These isolated hepatocytes can be then used for studying cellular metabolism, pharmacokinetics, toxicology of xenobiotics, translational research etc. The use of human hepatocytes also remains an important model for validating research done in animal models and can also reduce the number of animals used for research in line with the 3R ethical framework. Further, if the viability and yield of the isolated hepatocytes is lower than expected, this will highlight a methodological problem that can be addressed.

Antioxidant and hepatoprotective effects of &lt;i&gt;Lithocarpus polystachyus&lt;/i&gt; against carbon tetrachloride-induced injuries in rat

The present study aims to investigate the hepatoprotective and antioxidant effects of the total flavonoid of Lithocarpus polystachyus Rehd.(LP-F) in vitro and in vivo. The in vitro anti-oxidant property of total flavonoids was investigated by employing various established systems. Rats with carbon tetrachloride-induced liver injury were used to assess the hepatoprotective and anti-oxidant effect of total flavonoids in vivo. The level of activity of glutamate pyruvate transaminase, aspartate aminotransferase, alkaline phosphatase and gamma-glutamyl transpeptidase, total bilirubin, total cholesterol, triglycerides total protein and albumin contents in the serum and malondialdehyde, superoxide dismutase, catalase, and glutathione in the liver and kidney of the rats were assayed using standard procedures. The results showed the total flavonoids of L. polystachyus has strong hepatoprotective and anti-oxidant activity in vitro and in vivo. These data were supplemented with histopathological studies of rat liver sections. This suggests that the hepatoprotective activity of formulation is possibly attributed to its free radical scavenging properties.

Gamma-glutamyl transpeptidase as the marker of kidney graft function.

Gamma-glutamyl transpeptidase (GGT) is a glycoprotein of the external surface of various cell types. The activity of GGT has been observed in cells and tissues with secretory activity, such as the proximal tubular cells in kidneys. GGT also plays an important pro-oxidant role, stimulating the generation of hydroxyl radicals, and increases membrane lipid peroxidation. In this study we examined whether the monitoring of GGT activity in urine may be a prognostic factor of kidney allograft function. The study enrolled 107 Caucasian renal transplant recipients. Urine samples were collected for GGT and creatinine analysis on the 1st day after transplantation, and then in the 3rd and 12th month. Higher urine GGT activity in the 3rd month after transplantation was associated with significantly higher risk of graft failure (HR=1.063 per each U/g creatinine; 95%Cl:1.004-1.127; p=0.037) in the Cox proportional hazards model. Moreover, there were positive correlations between urine GGT and the grade of interstitial fibrosis (Rs=0.64, p=0.01) and tubular atrophy (Rs=0.54, p=0.056) in specimens collected in the 3rd month after transplantation. Our results suggest that higher urine GGT activity in the 3rd month after transplantation may be a prognostic factor of graft failure.

Subchronic toxicity study in rats of two new ethyl-carbamates with ixodicidal activity.

Female and male Wistar rats were used to determine the subchronic oral toxicities of two new ethyl-carbamates with ixodicidal activities (ethyl-4-bromphenyl-carbamate and ethyl-4-chlorphenyl-carbamate). The evaluated carbamates were administered in the drinking water (12.5, 25 and 50 mg/kg/day) for 90 days. Exposure to the evaluated carbamates did not cause mortality or clinical signs and did not affect food consumption or weight gain. However, exposure to these carbamates produced alterations in water consumption, hematocrit, percentages of reticulocytes, plasma proteins, some biochemical parameters (aspartate aminotransferase, gamma-glutamyl transpeptidase, cholinesterase, and creatinine activities), thiobarbituric acid reactive substances, and the relative weight of the spleen. Histologically, slight pathological alterations were found in the liver that were consistent with the observed biochemical alterations. The nonobserved adverse effect levels (NOAELs) of the evaluated carbamates were 12.5 mg/kg/day for both the female and male rats. The low severity and reversibility of the majority of the observed alterations suggest that the evaluated carbamates have low subchronic toxicity.

Bilateral acute pyogenic conjunctivitis with iritis induced by unilateral topical application of bacterial peptidoglycan muramyl dipeptide in adult rabbits

The factors responsible for the conjunctivitis and iritis associated with acute ocular infection and post enteric inflammatory disease are not fully known. The pro-inflammatory activity of unilateral topical application of muramyl dipeptide (MDP; the smallest bio-active Gram-positive and Gram-negative bacterial cell wall component) was investigated in adult rabbits. The resultant bilateral conjunctivitis/iritis and pyogenic responses were characterized. Bilateral symptoms were graded by slit lamp examinations; tear fluid, Schirmer tests (tear production), blood and aqueous humor (AH) samples were obtained from MDP-treated and untreated rabbits. MDP concentration, gamma-glutamyltranspeptidase activity (GGT; key enzyme in glutathione recapture, xenobiotic detoxification, eicosanoid synthesis and neutrophil function), protein concentration, and tear cell density, cytology, and immunofluorescent antibody reactivity to GGT and calreticulin (CRT; MDP-binding protein) were determined. MDP was cleared from ipsilateral tears and serum by 6 h, but was undetected in mock-treated contralateral tears. Bilateral signs of acute transient pyogenic conjunctivitis, characterized by tearing, lid edema, conjunctival hyperemia, chemosis and leukocytic infiltrate with iritis (erythema and aqueous flare) were detected. Milder symptoms occurred in the mock-treated contralateral eyes. Bilateral symptoms, tear production, tear protein, GGT activity, and mucopurulent discharge (containing up to 2.5–5.0 × 106 cells/mL) were elevated 4–8 h post MDP and resolved to near pre-treatment levels by 24 h. Tear GGT activity and protein levels were higher in MDP-treated and mock-treated contralateral eyes than in eyes of untreated adult rabbits (p's < 0.001). Elevated tear GGT activity was associated with histopathology and increased vascular and epithelial permeability to serum protein, GGT-positive epithelia cells, macrophages and heterophils. Repeat MDP applications induced recurrent induction and resolution patterns of bilateral conjunctivitis/iritis and tear GGT activity, but ipsilateral GGT responses were lower. The results suggest unilateral topical MDP application to adult rabbit eyes induces a bilateral acute pyogenic conjunctivitis/iritis (PCI) characterized by increased vascular and epithelial permeability similar to acute bacterial conjunctivitis in man. The detection of CRT/GGT positive heterophils in tears suggests efferocytosis (phagocytosis of dead/dying cells). Tear GGT activity may be a useful means to quantify MDP-induced toxicity and extraocular inflammation.

Lactobacillus plantarum TN627 significantly reduces complications of alloxan-induced diabetes in rats

This study aimed to assess the potential of the probiotic strain Lactobacillus plantarum TN627 for preventing alloxan-induced diabetes in rats. The oral administration of this probiotic was noted to significantly improve the immunological parameters, protect the pancreatic tissues, and reduce the pancreatic and plasmatic α-amylase activities and level of plasma glucose in the treated as compared to the control group of rats. Furthermore, this probiotic treatment was observed to markedly reduce pancreatic and plasmatic lipase activities and serum triglyceride and LDL-cholesterol rates and to increase the level of HDL-Cholesterol. It also exerted efficient protective effects on the liver and kidney functions evidenced by significant decreases in serum aspartate transaminase, alanine transaminase, lactate dehydrogenase, and gamma-glutamyl transpeptidase activities, as well as creatinine and urea contents. Taken together, the findings indicate that L. plantarum TN627 exhibits attractive in vivo antidiabetic effects that may be helpful in preventing diabetic complications in adult rats.

Is there evidence of early vascular disease in patients with obstructive sleep apnoea without known comorbidities? Preliminary findings.

We evaluated early atherosclerotic lesions in 20 non-smokers with newly diagnosed Obstructive Sleep Apnoea (OSA) and without known comorbidities by measuring common carotid artery intima media thickness (CCA-IMT), transcranial Doppler ultrasound (TCD), and ankle brachial index (ABI). These were compared with 20 healthy age- and BMI-matched controls. In OSA patients, CCA-IMT was not significantly higher vs. controls (0.74±0.17 vs. 0.66±0.12 mm, p=0.201) and it was positively correlated with neck circumference (r=0.466, p=0.039), arousal index (r=0.663, p=0.001), gamma-glutamyl transpeptidase activity (r=0.474, p=0.035) while it was negatively correlated with Forced Expiratory Volume in 1 sec (r=-0.055, p=0.012). No difference was noted between patients and controls in terms of vascular stenosis on TCD examination, while asymptomatic peripheral artery disease was found in one patient with OSA. In conclusion, OSA patients without known comorbidities exhibit a non-significant increase in CCA-IMT without further evidence of vascular disease, but additional experience in a larger patient series is needed.

Inhibition of key enzymes related to diabetes and hypertension by Eugenol in vitro and in alloxan-induced diabetic rats

The present study investigated the effect of treating diabetic rats with eugenol (EG). In vitro enzyme activity was measured in the presence of eugenol, and it was found to inhibit pancreatic α-amylase (IC50 = 62.53 µg/mL) and lipase (IC50 = 72.34 µg/mL) as well as angiotensin converting enzyme (ACE) activity (IC50 = 130.67 µg/mL). In vivo, EG reduced the activity of amylase in serum, pancreas and intestine also the peak level of glucose by 60% compared to diabetic rats. Furthermore, eugenol similar to acarbose reduced serum glycosylated hemoglobin (HbA1c), lipase and ACE levels. In addition, treatments with EG showed notable decrease in serum total-cholesterol, triglycerides and low density lipoprotein-cholesterol levels with an increase of high density lipoprotein-cholesterol. Overall, EG significantly reverted back to near normal the values of the biochemical biomarkers such as transaminases (AST&ALT), alkaline phosphatase (ALP), creatine phosphokinase (CPK) and gamma-glutamyl transpeptidase (GGT) activities, total-bilirubin, creatinine, urea and uric acid rates.

Helicobacter pylori–Induced Loss of Survivin and Gastric Cell Viability Is Attributable to Secreted Bacterial Gamma-Glutamyl Transpeptidase Activity

Helicobacter pylori is the etiologic agent of a series of gastric pathologies that may culminate in the development of gastric adenocarcinoma. An initial step in this process is the loss of glandular structures in the gastric mucosa, presumably as the consequence of increased apoptosis and reduced cellular regeneration, which may be attributed to the combination of several bacterial and host factors and to an unfavorable proinflammatory environment. In a previous study, we showed that survivin, a member of the inhibitor of apoptosis protein family, is expressed in the normal human gastric mucosa and that its levels decrease in the mucosa of infected patients and in gastric cells exposed in culture to the bacteria, coincident with increased cell death in the latter case. We investigated the bacterial factors responsible for loss of survivin in gastric cells exposed to H. pylori. The results of this study indicated that the loss of survivin due to H. pylori infection involves proteasome-mediated degradation of the protein. Studies with isogenic mutants deficient in either CagA, VacA, lipopolysaccharide, or gamma-glutamyl transpeptidase (GGT) implicated the latter in H. pylori-induced loss of survivin and cell viability. Moreover, experiments with the GGT inhibitor 6-diazo-5-oxo-l-norleucine and purified recombinant GGT protein indicated that secreted bacterial GGT activity was required and sufficient to induce these effects.