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Publication
Journal: Journal of Biochemistry
March/3/1993
Abstract
We constructed an expression plasmid (pMAMCRR51) that carried the entire protein-coding sequence of the rabbit cardiac ryanodine receptor cDNA, linked to the dexamethasone-inducible mouse mammary tumor virus promoter and Escherichia coli xanthine-guanine phosphoribosyltransferase (gpt). Chinese hamster ovary (CHO) cells were transfected with pMAMCRR51 and mycophenolic acid-resistant cells showing caffeine-induced intracellular Ca2+ transients were selected. Immunoprecipitation with a monoclonal antibody against the canine cardiac ryanodine receptor revealed that the cell clones thus selected exhibited Ca(2+)-dependent [3H]ryanodine binding activity, which was stimulated by 5 mM ATP or 1 M KCl. The apparent dissociation constant (Kd) for [3H]ryanodine was 6.6 nM in 1 M KCl, which was similar to the Kd obtained with cardiac microsomes. Immunoprecipitation also demonstrated that these cell clones expressed a protein indistinguishable in M(r) from the ryanodine receptor in canine cardiac microsomes. The ryanodine binding activity expressed in CHO cells increased significantly after dexamethasone induction. In saponin-skinned CHO cells transfected with pMAMCRR51, micromolar Ca2+ or millimolar caffeine evoked rapid Ca2+ release from the intracellular Ca2+ stores. In skinned control CHO cells, we did not observe such Ca2+ release activity. These results clearly demonstrate that the cardiac ryanodine receptor is stably expressed in internal membranes of CHO cells and functions as Ca(2+)-induced Ca2+ release channels.
Publication
Journal: Transplant International
June/8/1997
Abstract
The present study was designed to examine the in vivo effect of ebselen on reperfusion injury to the liver. Lipid peroxidation and glutathione (GSH) levels of the reperfused liver tissue, as well as hepatocellular damage (serum GOT, GPT, LDH, and histology) were examined. The production of thiobarbituric acid-reactive substance did not increase in the 60-min-reperfused liver tissue in the ebselen group. Ebselen completely suppressed the increase in lipid hydroperoxide production in the reperfused liver tissue. After the tissue GSH level was reduced by buthionine sulphoximine, ebselen failed to suppress the lipid peroxidation of the reperfused liver tissue. Serum levels of GOT, GPT, and LDH, histological analysis, and the tissue level of GSH clearly showed that ebselen protects the reperfused liver tissue, both structurally and functionally. We conclude that ebselen's primary effect on ischemia-reperfusion injury may be due to a GSH-peroxidase-like effect and/or the inhibitory effect of leukocyte infiltration.
Publication
Journal: Medical Education
September/30/2010
Abstract
BACKGROUND
This study aimed to assess if an additional patient feedback training programme leads to better consultation skills in general practice trainees (GPTs) than regular communication skills training, and whether process measurements (intensity of participation in the programme) predict the effect of the intervention.
METHODS
We carried out a controlled trial in which two sub-cohorts of GPTs were allocated to an intervention group (n = 23) or a control group (n = 30), respectively. In 2006, allocated first-year GPTs in the VU University Medical Centre attended a patient feedback training programme in addition to the regular communication skills training. The control group attended only regular communication skills training. Trainees were assessed by simulated patients who visited the practices and videotaped the consultations at baseline and after 3 months. The videotapes were randomly assigned to eight trained staff members. The MAAS-Global Instrument (range 0-6) was used to assess (a change in) trainee consultation skills.
RESULTS
were analysed using a multi-level, linear mixed-model analysis. Results Data on 50 GPTs were available for the follow-up analysis. Both intervention group and control group GPTs improved their consultation skills: mean MAAS-Global scores for all participants were 3.29 (standard deviation [SD] 0.75) at baseline and 3.54 (SD 0.66) at follow-up (P = 0.047). The improvement in MAAS-Global scores in the intervention group did not differ significantly from the improvement in the control group. The analysis showed a trend for intensity of participation in the patient feedback programme to predict greater improvement in MAAS-Global scores.
CONCLUSIONS
Although the baseline scores were already in the high range, consultation skills in both groups improved significantly. This is reassuring for current teaching methods. The patient feedback programme did not improve consultation skills more than regular communication skills training. However, a subgroup of GPTs who participated intensively in the programme did improve their consultation skills further in comparison with the less motivated subgroup.
Publication
Journal: Environmental and Molecular Mutagenesis
July/21/2003
Abstract
Transgenic rodents are valuable models for investigating the genotoxicity of chemicals in vivo. Here, we report the establishment of a novel transgenic rat for genotoxicity analysis. In this model, about 10 copies of lambdaEG10 DNA carrying the gpt gene of E. coli and the red/gam genes of lambda phage are integrated per haploid genome of Sprague-Dawley rats at position 4q24-q31. After recovery of lambdaEG10 phage, point mutations in the gpt gene and deletions in the red/gam genes are identified by 6-thioguanine and Spi(-) selection, respectively. To examine the suitability of these rats for performing in vivo mutagenicity assays, rats were treated with single intraperitoneal injections of ethylnitrosourea (ENU; 100 mg/kg) or benzo[a]pyrene (B[a]P; 62.5 and 125 mg/kg), and the mutant frequencies (MFs) in the liver were determined 7 days after the treatment. ENU enhanced the gpt MF about 7-fold over the control while it did not significantly increase the Spi(-) MF. B[a]P increased both the gpt and Spi(-) MFs several-fold in a dose-dependent manner. To examine the kinetics of MF, ENU was administered (50 mg/kg/day for 5 successive days) and gpt MFs in the liver were determined 7, 21, 35, and 70 days after the last injection. The MF increased to 8-fold and 13-fold over the control at 7 and 35 days, respectively, after the last injection and then slightly declined at 70 days. These kinetics are similar to those reported for ENU-treated lacZ transgenic mice. This novel transgenic rat could be useful for investigating species differences between rats and mice in their response to genotoxic agents.
Publication
Journal: Alcohol (Fayetteville, N.Y.)
July/19/2015
Abstract
The administration of disulfiram raises blood acetaldehyde levels when ethanol is ingested, leading to an aversion to alcohol. This study was aimed at assessing the effect of fenofibrate on voluntary ethanol ingestion in rats. Fenofibrate reduces blood triglyceride levels by increasing fatty acid oxidation by liver peroxisomes, along with an increase in the activity of catalase, which can oxidize ethanol to acetaldehyde. UChB drinker rats were allowed to consume alcohol 10% v/v freely for 60 days, until consumption stabilized at around 7 g ethanol/kg/24 h. About 1-1.2 g ethanol/kg of this intake is consumed in the first 2 h of darkness of the circadian cycle. Fenofibrate subsequently administered (50 mg/kg/day by mouth [p.o.]) for 14 days led to a 60-70% (p < 0.001) reduction of 24-h ethanol consumption. When ethanol intake was determined within the first 2 h of darkness, the reduction was 85-90% (p < 0.001). We determined whether animals chronically allowed access to ethanol and subsequently treated with fenofibrate, would a) increase liver catalase activity, and b) increase blood acetaldehyde levels after a 24-h ethanol deprivation and the subsequent administration of 1 g ethanol/kg. The oral administration of 1 g ethanol/kg produced a rapid increase in blood (arterial) acetaldehyde in fenofibrate-treated animals versus controls also administered 1 g/kg ethanol (70 μM vs. 7 μM; p < 0.001). Liver catalase activity following fenofibrate treatment was increased 3-fold (p < 0.01). Other hepatic enzymes responsible for the metabolism of ethanol (alcohol dehydrogenase and aldehyde dehydrogenase) remained unchanged. No liver damage was induced, as measured by serum glutamic-pyruvic transaminase (GPT) activity. The effect of fenofibrate in reducing alcohol intake was fully reversible. Overall, in rats allowed chronic ethanol intake, by mouth (p.o.), fenofibrate administration increased liver catalase activity and reduced voluntary ethanol intake. The administration of 1 g ethanol/kg (p.o.) to these animals increased blood acetaldehyde levels in fenofibrate-treated animals, suggesting the possible basis for the reduction in ethanol intake.
Publication
Journal: Research in Veterinary Science
July/6/2009
Abstract
The objective of this study was to investigate the expression and localization of HSP60 in the heart, liver, and kidney of acutely heat-stressed broilers at various stressing times. The plasma creatine kinase (CK) and glutamic pyruvic transaminase (GPT) concentrations statistic increased following heat stress. After 2h of heat stress, the tissues showed histopathological changes. Hsp60 expressed mainly in the cytoplasm of parenchyma cells heat stress. The intensity of the cytoplasmic staining varied and exhibited an organ-specific distribution pattern. Hsp60 levels in the hearts of heat-stressed chickens gradually increased at 1h (p<0.05) and peaked (p<0.05) at 5h; Hsp60 levels in the liver gradually decreased at 3h (p<0.05); Hsp60 levels in the kidney had no fluctuation. It is suggested that Hsp60 expression is tissue-specific and this may be linked to tissue damage in response to heat stress. The Hsp60 level is distinct in diverse tissues, indicating that Hsp60 may exert its protective effect by a tissue- and time-specific mechanism.
Publication
Journal: Journal of the autonomic nervous system
June/24/1992
Abstract
The effects of the sympathetic nervous system on liver injury induced experimentally by carbon tetrachloride (CCl4) were examined in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). It was found that the SHR had an elevated catecholamine (CA) content in the adrenal gland without any treatment, and fluorescence histochemistry also revealed dense adrenergic innervations in the liver. Moreover, the SHR showed greater sensitivity to CCl4 stimulation in the sympathetic nervous system than the WKY, resulting in a decreased hepatic blood flow in the acute stage and a depleted CA in the adrenal gland, a lowered blood pressure (BP) and a released non-esterified fatty acid (NEFA) from peripheral adipose tissue in the chronic stage. Upon repetition of the CCl4 treatments twice a week for 4 weeks, the liver injury was more severe in the SHR than in the WKY. Plasma glutamate-pyruvate transaminase (GPT) activity was increased in both strains but more significantly in the SHR than in the WKY. Histological examination of the liver in the SHR showed established cirrhosis, whereas only bridging fibrosis was seen in the WKY. These results suggest that the pathogenesis of the liver damage induced by CCl4 in the SHR, is attributable to the enhanced response of the sympathetic nervous system that releases massive amounts of CA which then lead to vasoconstriction and metabolic changes that promote liver damage.
Authors
Publication
Journal: Zeitschrift fur Rechtsmedizin. Journal of legal medicine
October/29/1986
Abstract
This study was performed to examine the relationship between postmortem biochemical values and cause of death. The follow samples were taken from 399 corpses: cerebrospinal fluid (CSF; n = 376, suboccipital), blood (n = 158, femoral vein), and urine (n = 101, at autopsy). (See Table 1 for causes of death) All samples were stored at -80 degrees C. A further 100 samples of blood were later taken and stored at +4 degrees C before testing. Biochemical determinations made were: glucose in CSF, blood, and urine (hexokinase method); lactate (LDH/GPT) and free acetone (HS-gas chromatography) in CSF; hemoglobin A1 in blood (microcolumn technique). In 34 cases fatal diabetic coma was considered verified by morphological and chemical findings. One hundred cases of sudden cardiac death were chosen as the main control group. In 32 of the 34 cases defined above, the value of the formula of Traub (glucose + lactate in CSF) exceeded 415 mg/dl. It is not influenced significantly by hyperglycemia or hyperlactatemia due to factors other than diabetes (i.e., carbon monoxide, asphyxia). After death the value rose till the 30th hpm, then remained stable for at least 1 week. Fatal coma was defined as the ketoacidotic form if free acetone in CSF ranged above 21 mg/l. In these cases, CSF glucose and free acetone correlated positively. Hemoglobin A1 remained stable after death. Its amount was independent from postmortem blood glucose, postmortem interval and total hemoglobin. Furthermore, the manner of storage (-80 degrees or +4 degrees C) had no significant influence on its values. In 29 of 34 cases of fatal coma, Hb A1 exceeded 12.1%. Analysis of urine glucose showed elevated levels (over 500 mg/dl) in diabetic comas. On conclusion, fatal diabetic coma seems indicated as the cause of death if measured values of postmortem biochemistry exceed the following limits: CSF-Traub 415 mg/dl, free acetone (CSF) 21 mg/l; Hb A1 12.1%; urine glucose 500 mg/dl. Most important are the Traub formula and hemoglobin A1. Usually, in fatal coma both values are elevated. If both of them are normal, diabetic coma can nearly be excluded. Combined evaluation of all values is absolutely necessary. Morphology must also always be taken into account. Consequently, a diagnosis of fatal coma can be obtained by a process of elimination.
Publication
Journal: Nucleic Acids Research
September/24/2000
Abstract
We present evidence of formation of an intramolecular parallel triple helix with T*A.T and G*G.C base triplets (where * represents the hydrogen bonding interaction between the third strand and the duplex while. represents the Watson-Crick interactions which stabilize the duplex). The third GT strand, containing seven GpT/TpG steps, targets the polypurine sequence 5'-AGG-AGG-GAG-GAG-3'. The triple helix is obtained by the folding back twice of a 36mer, formed by three dodecamers tethered by hydroxyalkyl linkers (-L-). Due to the design of the oligonucleotide, the third strand orientation is parallel with respect to the polypurine strand. Triple helical formation has been studied in concentration conditions in which native gel electrophoresis experiments showed the absence of intermolecular structures. Circular dichroism (CD) and UV spectroscopy have been used to evidence the triplex structure. A CD spectrum characteristic of triple helical formation as well as biphasic UV and CD melting curves have been obtained in high ionic strength NaCl solutions in the presence of Zn(2+) ions. Specific interactions with Zn(2+) ions in low water activity conditions are necessary to stabilize the parallel triplex.
Publication
Journal: Naunyn-Schmiedeberg's Archives of Pharmacology
July/10/2005
Abstract
This study addressed the question of whether thaliporphine, a phenolic aporphine alkaloid obtained from Chinese herbs and possessing antioxidant and alpha-1 adrenoceptor antagonistic activity, has protective effects in endotoxaemic rats and we attempted to elucidate the mechanisms contributing to such protective effects. Injection of rats with endotoxin (E. coli lipopolysaccharide, LPS) induced severe hypotension and tachycardia as well as vascular hyporeactivity to noradrenaline. Pretreatment of LPS-treated rats with thaliporphine attenuated the delayed hypotension significantly whilst only a higher dose (1 mg/kg) of thaliporphine decreased LPS-induced tachycardia. LPS significantly increased nitric oxide (NO.) and superoxide anion (O(2).(-)) levels, a response that was reduced by pretreatment with 1 mg/kg thaliporphine. Endotoxaemia for 240 min resulted in a bell-shaped time course for the change of serum tumour necrosis factor-alpha (TNF-alpha) level with a peak at 60 min. Pretreatment of LPS-treated rats with 1 mg/kg thaliporphine significantly reduced the serum TNF-alpha level at 60 min. In addition, LPS caused a biphasic change in blood glucose and thaliporphine attenuated the late-phase decrease in blood glucose. Endotoxaemia induced multiple organ injury in the liver, kidney and heart, as indicated by increases of aspartate aminotransferase (GOT), alanine aminotransferase (GPT), creatinine (CRE), lactate dehydrogenase (LDH) and creatine phosphate kinase muscle-brain (CKMB) levels in serum. These increases of biochemical markers and inflammatory cell infiltration into injured tissues were reduced significantly by treatment with thaliporphine. In addition, thaliporphine increased the survival rate of LPS-treated mice dose-dependently. In conclusion, our results suggest that thaliporphine could be a novel agent for attenuating endotoxin-induced circulatory failure and multiple organ injury and may increase the survival rate. These beneficial effects of thaliporphine may be attributed to the suppression of TNF-alpha, NO. and O(2).(-) production.
Publication
Journal: Hepatology
August/12/1996
Abstract
The expression of the immediate early genes (IEGs) c-fos and e-jun have been hypothesized to potentially play key roles in mediating cellular responses following injury to the liver. In this study, we sought to evaluate the potential involvement of c-jun and c-fos as determinants either of cellular regeneration or programmed cell death following ischemia/reperfusion (I/R) in mouse liver. To this end, we have analyzed the in situ messenger RNA (mRNA) expression patterns of c-jun and c-fos following lobar I/R in mouse liver. The expression patterns of c-jun and c-fos were correlated with four criteria for tissue repair and injury, including: 1) morphological determinations of regeneration using immunocytochemical detection of proliferating cell nuclear antigen (PCNA), 2) programmed cell death (apoptosis) using the in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method, 3) histopathologic assessment of hepatocellular necrosis, and 4) serum glutamic pyruvic transaminase (GPT) levels. Increasing lengths of lobar ischemia for 3, 60, and 90 minutes followed by reperfusion directly correlated with the extent of liver injury as determined by serum transaminases and hepatocellular necrosis. PCNA expression in the liver was elevated at 1 to 6 hours following liver reperfusion and returned to baseline levels by 20 hours in both ischemic and nonischemic lobes. In contrast, apoptotic responses peaked only in ischemic lobes at 6 hours' postreperfusion and remained elevated out to 20 hours. Two distinct patterns of c-jun and c-fos expression were observed during the acute (1-3 hours) and subacute (6-20 hours) phases of liver responses to I/R including: 1) coexpression of c-jun and c-fos mRNA within damaged regions of the liver at 1 to 3 hours' postreperfusion, and 2) a decline in c-fos expression with sustained high levels of c-jun expression within a subset of cells bordering necrotic/apoptotic regions of the liver at 6 to 20 hours' postreperfusion. These findings suggest that coexpression of both c-jun and c-fos may be involved in mediating early tissue repair processes in liver remodeling following I/R. In contrast, the onset of hepatocellular apoptosis correlated with sustained c-jun expression, in the absence of c-fos, and suggests that these changes in the molecular profile of immediate early gene expression may regulate cellular responses that signal hepatocytes for programmed cell death.
Publication
Journal: Academic Emergency Medicine
March/9/2006
Abstract
OBJECTIVE
Hemorrhage initiates an inflammatory response that induces the systemic release of cytokines and sequestration of polymorphonuclear neutrophils. Sequestered polymorphonuclear neutrophils release proteases, including matrix metalloproteinases (MMPs) that degrade elements of the extracellular matrix, contributing to the morbidity and mortality seen from hemorrhage. Activation of MMPs may be associated with changes in transforming growth factor beta1 (TGF-beta1) and caspase-3 signaling pathways. In this study, the authors examined hemorrhage-induced changes in the expression of rat hepatic MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-l), TGF-beta1, and caspase-3 activities in the presence and absence of the MMP inhibitor hydroxamate.
METHODS
Hemorrhagic shock was induced in fasted, anesthetized, and cannulated rats by rapid phlebotomy to a mean arterial pressure level of 40 mm Hg, maintained for 90 minutes by withdrawal and infusion of blood, followed by a resuscitation period of lactated Ringer's infusion. Rats received either hydroxamate (25 mg/kg) or vehicle by gavage before hemorrhage. Twenty-four hours after resuscitation, plasma and liver samples were collected. Liver MMP-9, TGF-beta1, and caspase-3 levels were quantified by Western immunoblotting. Plasma glutamic oxaloacetic transaminase (GOT) and plasma glutamic pyruvic transaminase (GPT) were determined enzymatically.
RESULTS
Plasma GOT, plasma GPT, and liver MMP-9, TGF-beta1, and caspase-3 levels were all significantly elevated at 24 hours postresuscitation when compared with the control values. Hepatic TIMP-1, an in vivo inhibitor of MMP-9, was unaltered at 24 hours. Hydroxamate treatment reduced GOT, GPT, MMP-9, TGF-beta1, and caspase-3 levels at 24 hours. The mortality of hemorrhaged untreated rats was 29% after 24 hours, and pretreatment with hydroxamate reduced mortality to 0%.
CONCLUSIONS
These results indicate the beneficial effects of MMP inhibitor in preventing an increase in GOT, GPT, MMP-9, TGF-beta1, and caspase-3 activity with the potential for improvement of hepatic injury due to hemorrhage.
Publication
Journal: Pediatric Dermatology
September/1/1999
Abstract
The cutaneous signs of anorexia nervosa (AN) and bulimia nervosa (BN) have been described previously in adult patients. For the first time, we present here dermatologic findings in children and adolescents suffering from eating disorders. Thirty consecutive young anorexic and bulimic inpatients (8 to 17 years of age, mean 15.1 years) underwent a standardized dermatologic examination. Patients were checked for abnormalities of the skin including atopic stigmata, dermographism, hair, nails, and oral cavity. Serum was obtained for hemoglobin, iron, zinc, GPT, thyroid, and sex-hormone levels. In 13 patients, the total serum IgE was determined, and a prick test was carried out with defined type I allergens. Findings in order of frequency included xerosis of the skin, white dermographism, diffuse hypertrichosis, acrocyanosis, scars, diffuse effluvium, artifacts, brittle nails, and onychophagia. Significant co-relations were found between the presence of hypertrichosis and the existence of amenorrhea or a body mass index of less than 16. In 22 patients a low T3 level was found. In summary, children and adolescents suffering from AN or BN show dermatologic features similar to those reported in older patients. Special findings in this age group are extensive lanugo hair and signs of autoaggressive behavior.
Publication
Journal: Journal of Ethnopharmacology
June/17/2007
Abstract
The three purgative Cheng-Chi-Tang decoctions (CCTDs) including Ta-Cheng-Chi-Tang (TCCT), Xiao-Chen-Chi-Tang (XCCT), and Tiao-Wei-Chen-Chi-Tang (TWCCT) are used for treating gastrointestinal disorders, including liver diseases in traditional Chinese medicine. However, the underlying mechanisms as liver disease remedies are far from fully clarified. The objective of the study is to investigate and compare the antioxidant activity of the three purgative CCTDs in order to delineate their hepatic protective potential and mechanism. Antioxidant activity measured with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test indicated XCCT as the most potent preparation (IC(50) 8.94 microg/ml). In tert-butylhydroperoxide (TBH, 50mM)-induced lipid peroxidation in ICR mice liver homogenates, XCCT also showed stronger and dose-dependent inhibitory activity against TBH-induced malondialdehyde (MDA, a marker of lipid peroxidation) production (IC(50) 53.66 microg/ml). In addition, XCCT showed dose-dependent protective effect against TBH-induced cytotoxicity in normal human Chung liver cells Furthermore, in carbon tetrachloride (CCl(4))-induced acute liver injury model, mice pretreated with 0.2g/kg and 0.4 g/kg of XCCT extracts showed a decrease of 59.8 and 43.1% in serum glutamic oxaloactetic transaminase (GOT) level, 51.4 and 52% in glutamic pyruvate transaminase (GPT) level, along with a reduction of 31 and 15% in MDA level, respectively, similar to the effects exerted by silymarin. XCCT pretreated mice also showed milder necrotic changes in the microscopic picture of the liver. The results suggest that XCCT has significant antioxidant activity and hepatic protection potential.
Publication
Journal: Journal of Agricultural and Food Chemistry
June/22/2014
Abstract
This study investigated the influence of phenolic caffeic acid on obesity in mice fed a high fat diet and its underlying mechanisms base on adipose and hepatic lipid lipogenesis. C57BL/6 mice were fed a normal diet or a HFD (20% fat, w/w) with or without caffeic acid (0.02% and 0.08%, w/w) for 6 weeks. The effects of caffeic acid on hyperlipidemia, hyperglycemia, visceral fat accumulation, and related enzyme activities in HFD-mice are examined. The supplementation of caffeic acid significantly lowered body weight, visceral fat mass, plasma GOT and GPT levels, FAS activity, and free fatty acid compared to the HFD group. Caffeic acid also lowered triglyceride and cholesterol concentrations in plasma and liver. Furthermore, we showed that caffeic acid efficiently inhibited cholesterol biosynthesis as evidenced by 3-hydroxy-3-methylglutaryl CoA reductase in the liver. Caffeic acid supplementation suppressed the activity of lipogenesis via sterol regulatory element-binding protein 1 c and its target enzyme fatty acid synthase. In addition, caffeic acid resulted in increased phosphorylation of AMP-activated protein kinase and decreased acetyl carboxylase, a downstream target of AMPK, which are related to fatty acid β-oxidation in the liver. In conclusion, these results indicate that caffeic acid exhibits a significant potential as an antiobesity agent by suppression of lipogenic enzymes and hepatic lipid accumulation.
Publication
Journal: Biochemical Journal
September/9/2009
Abstract
PH1 (primary hyperoxaluria type 1) is a severe inborn disorder of glyoxylate metabolism caused by a functional deficiency of the peroxisomal enzyme AGXT (alanine-glyoxylate aminotransferase), which converts glyoxylate into glycine using L-alanine as the amino-group donor. Even though pre-genomic studies indicate that other human transaminases can convert glyoxylate into glycine, in PH1 patients these enzymes are apparently unable to compensate for the lack of AGXT, perhaps due to their limited levels of expression, their localization in an inappropriate cell compartment or the scarcity of the required amino-group donor. In the present paper, we describe the cloning of eight human cytosolic aminotransferases, their recombinant expression as His6-tagged proteins and a comparative study on their ability to transaminate glyoxylate, using any standard amino acid as an amino-group donor. To selectively quantify the glycine formed, we have developed and validated an assay based on bacterial GO (glycine oxidase); this assay allows the detection of enzymes that produce glycine by transamination in the presence of mixtures of potential amino-group donors and without separation of the product from the substrates. We show that among the eight enzymes tested, only GPT (alanine transaminase) and PSAT1 (phosphoserine aminotransferase 1) can transaminate glyoxylate with good efficiency, using L-glutamate (and, for GPT, also L-alanine) as the best amino-group donor. These findings confirm that glyoxylate transamination can occur in the cytosol, in direct competition with the conversion of glyoxylate into oxalate. The potential implications for the treatment of primary hyperoxaluria are discussed.
Publication
Journal: American Journal of Physical Anthropology
December/20/1982
Abstract
Allele frequencies are reported for 19 blood group, red cell enzyme, and serum protein loci (ABO, Rh, MN, Hb-A, LDH-A, LDH-B, SOD, PGM-1, PGM-2, 6PGD, GPT, ESD, ADA, ACP, PGK, MDH, Alb, Hp, and Tf) determined from 310 blood samples collected among the Gainj, a small population of tribal horticulturalists from highland Papua New Guniea. Fourteen of these loci display genetic variants, and ten of them are sufficiently polymorphic to permit a preliminary analysis of Gainj population structure. Patterns of variation among subdivisions of the population are analyzed using an approach analogous to a multivariate analysis of variance with unbalanced design, and weighted genetic distances are extracted from the results. The distance analysis indicates that patterns of genetic variation within this population reflect the geographical distribution of subdivisions, as well as subdivision size and movement among subdivisions. A parallel analysis of the Gainj and two other tribal groups from highland New Guinea, the Murapin Enga and the Simbai Valley Maring, suggests that the Gainj are both genetically divergent from neighboring populations and internally highly differentiated.
Publication
Journal: Journal of Ethnopharmacology
December/8/2008
Abstract
OBJECTIVE
Cajanus cajan Linn. (Leguminosae) is a nontoxic edible herb, widely used in Indian folk medicine for the prevention of various liver disorders. In the present study we have demonstrated that methanol-aqueous fraction (MAF2) of Cajanus cajan leaf extract could prevent the chronically treated alcohol induced rat liver damage.
METHODS
Chronic doses of alcohol (3.7 g/ kg) orally administered to rats for 28 days and liver function marker enzymes such as GPT, GOT, ALP and anti-oxidant enzyme activities were determined. Effect of MAF2 at a dose of 50mg/kg body weight on alcohol treated rats was noted.
RESULTS
Alcohol effected significant increase in liver marker enzyme activities and reduced the activities of anti-oxidant enzymes. Co-administration of MAF2 reversed the liver damage due to alcohol; it decreased the activities of liver marker enzymes and augmented antioxidant enzyme activities. We also demonstrate significant decrease of the phase II detoxifying enzyme, UDP-glucuronosyl transferase (UGT) activity along with a three- and two-fold decrease of UGT2B gene and protein expression respectively. MAF2 co-administration normalized UGT activity and revived the expression of UGT2B with a concomitant expression and nuclear translocation of Nrf2, a transcription factor that regulates the expression of many cytoprotective genes.
CONCLUSIONS
Cajanus cajan extract therefore shows a promise in therapeutic use in alcohol induced liver dysfunction.
Publication
Journal: Glycobiology
June/28/1998
Abstract
The gene for the human dolichol cycle GlcNAc-1-P transferase (ALG7/GPT) was cloned by screening a human lung fibroblast cDNA library. The library was constructed in a Saccharomyces cerevisiae expression vector, and the positive clone was identified by complementation of the conditional lethal S.cerevisiae strain YPH-A7-GAL. This strain was constructed by replacing the endogenous promoter of the GPT-gene by the stringently regulated GAL1-promoter. This construct allows to specifically suppress the endogenous enzyme activity. The insert of the positive clone displayed an open reading frame of 1200 nucleotides, coding for a putative protein of 400 amino acids with a calculated molecular weight of 44.7 kDa. The deduced protein sequence shows a homology of over 90% when compared with other mammalian GPT sequences, thus resembling the close phylogenetic relationship between mammalian species. This homology however decreases to 40-50% when compared to more distantly related organisms such as S.cerevisiae , Schizosaccharomyces pombe , or Leishmania amazonensis . Biochemical characterization of the recombinant protein showed that it is functionally expressed in the S.cerevisiae strain YPH-A7-GAL. GlcNAc- and GlcNAc2-PP-Dolichol biosynthesis could be shown with isolated S.cerevisiae membranes from cells harboring the recombinant plasmid and grown on glucose thus suppressing transcription of the endogenous gene. Synthesis could be stimulated by dolicholphosphate and was inhibited by tunicamycin. These results show that we have cloned the human GlcNAc-1-P transferase by heterologous complementation in S. cerevisiae, a strategy that may be useful for the cloning and characterization of glycosyltransferases from a variety of organisms.
Publication
Journal: Biological Trace Element Research
May/11/2015
Abstract
This experiment was performed in order to investigate the effects of chitosan-Zn chelate (CS-Zn) on activities of antioxidant enzymes and immune function in weaned piglets. One hundred and twenty weaned piglets (Duroc × Landrace × Yorkshire) with 7.12 ± 0.25 kg body weight were allotted to four treatments. A basal diet without Zn supplementation was used as control group. The other three treatments were fed the control diet supplemented with 100 mg/kg Zn as ZnSO4, 100 mg/kg Zn as CS-Zn, 100 mg/kg Zn as ZnSO4 and chitosan (the content of chitosan was the same as that of CS-Zn), respectively. The feeding trial lasted 30 days. Spleen index of pigs fed dietary CS-Zn was higher (p < 0.05) than that of control pigs. Thymus index and lymph node index did not differ among the pigs fed any diets (p>> 0.05). T-AOC levels, Cu-ZnSOD, and GSH-PX activities in serum or liver of the pigs receiving CS-Zn diet were higher than those of the pigs fed CS+ZnSO4 or ZnSO4 diets (p < 0.05). These pigs fed dietary CS-Zn also showed lower MDA content in liver compared with the pigs fed other diets (p < 0.05). Serum IgA, complement 3, and complement 4 levels of pig fed dietary CS-Zn was higher than those of the pigs fed other diets (p < 0.05). Supplemental dietary Zn did not change serum IgG and IgM levels (p>> 0.05). The ALP activity of pigs fed dietary CS-Zn was higher than those of the pigs fed other three diets (p < 0.05). No significant differences were founded in serum GOT or GPT activities of pigs fed dietary Zn (p>> 0.05). The results of the present study indicated that chitosan-Zn chelate could increase antioxidant capacity and improve immune function in weaned piglets compared with ZnSO4 or chitosan.
Publication
Journal: Bollettino chimico farmaceutico
April/22/1998
Abstract
Three different synthetic chocolate colourant agents (A, B and C) were administered to healthy adult male albino rats for 30 and 60 day periods to evaluate their effects on body weight, blood picture, liver and kidney functions, blood glucose, serum and liver lipids, liver nucleic acids (DNA and RNA), thyroid hormones (T3 and T4) and growth hormone. In addition, histopathological examinations of liver, kidney and stomach sections were studied. These parameters were also investigated 30 days after colourant stoppage (post effect). Ingestion of colourant C (brown HT and indigocarmine) significantly decreased rat body weight, serum cholesterol and HDL-cholesterol fraction, while, T4 hormone, liver RNA content, liver enzymes (S. GOT, S. GPT and alkaline phosphatase), total protein and globulin fractions were significantly elevated. Significant increases were observed in serum total lipids, cholesterol, triglycerides, total protein, globulin and serum transaminases in rats whose diets were supplemented with chocolate colours A and B (sunset yellow, tartrazine, carmoisine and brilliant blue in varying concentrations). Haematological investigations demonstrated selective neutropenia and lymphocytosis with no significant alterations of total white blood cell counts in all rat groups, while haemoglobin concentrations and red blood cell counts were significantly decreased in the rats who were administered food additives A and B. Eosinophilia was noted in rats fed on colourant A only. No changes were recorded for blood glucose, growth hormone and kidney function tests. Histopathological studies showed brown pigment deposition in the portal tracts and Van Küpffer cells of the liver as well as in the interstitial tissue and renal tubular cells of the kidney mainly induced by colourant A. Congested blood vessels and areas of haemorrhage in both liver and renal sections were revealed in those rats who were given colourants B and C. There were no-untoward-effects recorded in the stomach tissue.
Publication
Journal: Science of the Total Environment
December/6/2001
Abstract
The objective of this study was to assess the relationship between blood-lead levels (BLL), hematological, liver and renal indicators among workers in a lead battery factory in Taiwan over a 10-year period. Blood samples were taken periodically from 30 workers and BLL, HGB (hemoglobin), RBC (red blood cells), WBC (white blood cells) and HCT (hematocrit) were measured. Levels of GPT (alanine aminotransferase) and Crea (creatinine) in the blood were assessed to indicate liver and renal function, respectively. The results showed that there was a general decrease in BLL over the 10-year period (except for 1993). There was a similar trend for HCT, RBC and Crea. There was no significant trend for the other health indicators. Four generalized estimating equation (GEE) models [correlation model (A), threshold correlation model (B), instant change model (C) and lag change model (D)] were set up to demonstrate the causal relationship between BLL and the other health indicators. Models A and C showed that BLL correlated positively with RBC, but negatively with Crea. Model B showed that BLL correlated positively with GPT. There were no significant correlations of BLL with the other indicators. Models C and D, (GEE with logit link function to analyze the association between changes BLL and the other health indicators) showed that when BLL increased, RBC and HCT increased, both longitudinally and cross-sectionally. The authors conclude that long-term exposure to lead stimulates production of RBC and HCT, but the effect on liver and renal function was unclear.
Publication
Journal: Geophysical Research Letters
June/17/2015
Abstract
Up to now, state-of-the-art empirical slant delay modeling for processing observations from radio space geodetic techniques has been provided by a combination of two empirical models. These are <em>GPT</em> (Global Pressure and Temperature) and GMF (Global Mapping Function), both operating on the basis of long-term averages of surface values from numerical weather models. Weaknesses in <em>GPT</em>/GMF, specifically their limited spatial and temporal variability, are largely eradicated by a new, combined model <em>GPT</em>2, which provides pressure, temperature, lapse rate, water vapor pressure, and mapping function coefficients at any site, resting upon a global 5° grid of mean values, annual, and semi-annual variations in all parameters. Built on ERA-Interim data, <em>GPT</em>2 brings forth improved empirical slant delays for geophysical studies. Compared to <em>GPT</em>/GMF, <em>GPT</em>2 yields a 40% reduction of annual and semi-annual amplitude differences in station heights with respect to a solution based on instantaneous local pressure values and the Vienna mapping functions 1, as shown with a series of global VLBI (Very Long Baseline Interferometry) solutions.
Publication
Journal: Pharmacognosy Research
November/9/2011
Abstract
The present study reports protective activity of ethyl acetate fraction of methanol extract of stem bark of Ceiba pentandra against paracetamol-induced liver damage in rats. The ethyl acetate fraction (400 mg/kg) was administered orally to the rats with hepatotoxicity induced by paracetamol (3 gm/kg). Silymarin (100 mg/kg) was used as positive control. High performance thin layer chromatography (HPTLC) fingerprinting of ethyl acetate fraction revealed presence of its major chemical constituents. A significant (P < 0.05) reduction in serum enzymes GOT (ALT), aspartate aminotransferase (AST), GPT alkaline phosphatase (ALP), total bilirubin content and histopathological screening in the rats treated gave indication that ethyl acetate fraction of methanolic extract of Ceiba pentandra possesses hepatoprotective potential against paracetamol-induced hepatotoxicity in rats.
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