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Biomedical subjects

J Eshchar

Publications and source records attributed to J Eshchar.

At least 37 records · Page 2Linked to original sources

B-N-acetyl hexosaminidase (B-NAH) serum levels after endotoxin administration into the portal vein in the rat.

Endotoxin was injected directly into the portal vein in rats with and without common bile duct (CBD) ligation. B-N-acetyl hexosaminidase (B-NAH) activity levels in the serum were found to be significantly elevated 24 h later in both groups. Serum bile acid levels were found to be significantly higher in the endotoxin-injected groups of rats compared to controls. Thus, endotoxin, as well as bile acids, may cause damage to Kupffer cell membranes, resulting in accumulation of B-NAH in rat serum.

Animals↗

Hepatotoxicity induced by the Oriental hornet (Vespa orientalis) venom sac extract.

Experiments were performed to investigate the nature of the in vitro and human liver damage exposed to hornets' acute or repeated stings. The hornet investigated is the one ubiquitous in Israel - Vespa orientalis. Experiments were performed in living cats and rats, after single or multiple exposures to venom-sac extracts (VSE) and in various doses. The injury was demonstrated by the increased levels of enzymes, bile acids and cholesterol in serum. Also measured was Beta-N-acetyl hexosaminidase (BNAH) which probably is the only biochemical indicator available of Kupffer-cell function. This, too, was found increased. Other experiments consisted of perfusion of the isolated, intact, rat liver in situ with measurements of enzyme leakage into perfusate and of bile flow. Another set of experiments involved the effects of VSE on in vitro monolayer tissue culture of rat embryos' livers. We examined damage to organelles and compared the damage produced by intact VSE with that produced by the venom sac extract after treatment by heat or dialysis. Light morphology, special stains, electron microscopy and morphometry were all performed. In the first set of experiments no shock was observed in cats and rats exposed to VSE. The increases in enzymes' activity in serum and liver perfusion fluid were significant. Histochemistry indicated decrease of hepatic glycogen and of cellular succinic dehydrogenase as well as hepatic fat infiltration and an increase of alkaline phosphatase activity in liver cells close to the bile capillaries.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Hepatotoxicity of oriental hornet venom].

Reports of hepatic damage following multiple stings by hornets led to this study of the effects of venom sac extract (VSE) from the oriental hornet. We used in-vivo models (serum of cats following a single exposure, and of rats following repeated exposures), in-situ models (perfusion of intact livers) and in-vitro models (monolayers of fetal rat liver tissue culture). Enzyme activities were measured in serum, in perfusates, and in media of cultures, as well as in liver fractions obtained by ultracentrifugation. In cats, levels of albumin, total proteins, electrolytes, urea, cholesterol, bilirubin and blood gases were determined. Bile acids were determined in bile secreted from perfused rat livers. Histologic, histochemical and electron-microscopic studies were also performed. It is concluded that VSE is the first animal product known to possess hepatotoxic properties. The venom mainly damages hepatic cellular membranes, and mitochondria are the organelles most severely injured; cholestasis also results. The damage is partially reversible, and occurs in mammals, including man.

Animals↗

Hepatotoxic effects of repeated administration of oriental hornet (Vespa orientalis) venom.

Venom sac extract (VSE) of the Oriental hornet (Vespa orientalis) has been shown to exert a toxic effect on hepatic cells. The present work set out to examine its effect on liver cells using serum levels of a lysosomal hydrolase as a marker of injury in rats. Serum activities of beta-N-acetyl hexosaminidase (BNAH; EC 3.2.1.30) were found to be positively correlated with the number of treatments received by the rats. The maximal elevation occurred from the third to the sixth day and comprised a 2-3-fold increase over the control mean level. This enhancement effect was reversible. The rat envenomend for 2 wk showed 3.5 times as much BNAH activity as in control rats. Biochemical analysis revealed increased specific activity of the lysosomal enzyme in rats treated repeatedly with VSE.

Animals↗

Aeromonas in adult diarrhea: an enteropathogen or an innocent bystander?

This is a study from a district hospital in Israel serving a population of 250,000. During 1986-1987, 1,005 stool specimens were cultured from 932 adult inpatients with acute diarrhea. Seventeen yielded Aeromonas species. Of the 12 strains phenotyped, 10 qualified as enteropathogenic. Five hundred stool specimens from asymptomatic control subjects, inhabitants of the same region, were negative for Aeromonas. The finding of Aeromonas as the apparently sole pathogen in acute adult diarrhea in a geographical area with a negligible asymptomatic carriage rate lends support to the possibility that Aeromonas is an enteropathogen in adults.

Adolescent↗

Inflammatory bowel disease and serum beta-N-acetylhexosaminidase.

Serum beta-N-acetylhexosaminidase levels in 49 patients with inflammatory bowel disease (IBD; 23 patients with ulcerative colitis, 10 with Crohn's disease, and 16 with ileostomy after total proctocolectomy) as well as in healthy normal controls were determined. They were found to be significantly elevated in 91% of all patients, disregarding the state of activity of the disease. It seems most likely that activated macrophages are the source of this lysosomal hydrolase in the serum of IBD patients since other theoretical possibilities, like damaged hepatocytes or elevated serum bile acid levels, are not relevant for these patients.

Adolescent↗

Serum-beta-N-acetyl hexosaminidase (beta-NAH) in the elderly.

Serum levels of beta-N-Acetyl Hexosaminidase (beta-NAH) provide information on the normal non-phagocytic function of Kupffer cells in the liver. Beta-NAH can thus be used as an indicator for non-parenchymal non-phagocytic liver cell function, whereas most of the more routine liver function tests measure hepatocytic status or function. Serum beta-NAH activity levels found in 49 patients and 10 healthy individuals above the age of 65 did not differ significantly from those found in younger controls. The results clearly indicate that beta-NAH serum activity in the aged is within normal limits and, if accepted as a routine measure of the non-phagocytic function of non-parenchymal liver cells, could be used in all adults.

Aged↗

A comparison of metronidazole and sulfasalazine in the maintenance of remission in patients with ulcerative colitis.

In a double-blind, randomized trial, we tested the effectiveness of metronidazole (0.6 g/day) against sulfasalazine (2 g/day) in the maintenance of remission in patients with ulcerative colitis. The patients were in remission for 1-11 months at entry to trial, which lasted for 12 months. Forty patients entered the trial and 33 completed it. Metronidazole was found to be slightly more effective than sulfasalazine, a difference statistically significant only at 12 months. Six patients also completed a crossover trial. Remission was maintained for 12 months in 3 patients by metronidazole and in none of the 6 by sulfasalazine. No significant side effects were noted, and in particular, no paresthesias were reported. This trial, as well as our previous one, suggests that metronidazole may be useful in the maintenance of remission in patients with ulcerative colitis, but that it is ineffective in the therapy of the acute attack.

Clinical Trials as Topic↗

Duodenal ulcer in the elderly.

Of 333 duodenal ulcer (DU) patients 75 (22.5%) were aged 65-93 years (study group). Ninety-two percent (306 patients) of the entire group were diagnosed endoscopically, and all were followed prospectively. In the study group of the older patients there were fewer smokers, but more patients used steroids and other nonsteroidal antiinflammatory drugs (NSAIDs) and had more arteriosclerotic heart disease than the younger control group. Presenting signs and symptoms were similar in both age groups, although painless upper gastrointestinal bleeding was more common in the elderly, and pain, when present, tended to be milder. Bleeding episodes were more prevalent in the older age group. Another difference between the groups was the larger incidence of concurrent gastric ulcer and DU observed endoscopically in the study population. Steroids and NSAIDs could be etiologically connected to bleeding in the older patients, as well as to their relative lack of pain. We conclude that DU in the elderly tended to present atypically and that pain was not the major symptom of activity. This places a different emphasis on diagnostic and therapeutic criteria.

Adult↗

Attitude of hospital personnel toward hepatitis B vaccination.

During a 1-yr period (November 1985-86), a free-of-charge vaccination program against hepatitis B was offered to 809 of the 1200 medical workers in a 650-bed general and regional hospital in Israel. Three hundred and eighteen (39.3%) accepted the offer and were vaccinated. The higher rates of acceptance were among cleaning personnel (96.3%) and student nurses (63.9%). The lower rates of acceptance were among physicians (46.5%) and nurses (24.9%). Different types of fear, as well as lack of knowledge, were the reasons responsible for 73.3% of all refusals. More specific and continuous health educational efforts among high-risk groups should be initiated for voluntary vaccination programs in Israel.

Attitude of Health Personnel↗

Liver damage induced by Oriental hornet venom sac extract at the level of subcellular fractions.

The hepatotoxic effect of venom sac extract (VSE) of the Oriental hornet has already been demonstrated using the well-known models of experimental toxicology: in vivo, isolated in situ and in vitro. The present work deals with a series of 48 rats treated daily with 5 mg VSE/kg body weight for 1-14 days. Serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) were measured. Liver tissue fractionation was performed. Detailed information on the topographical and functional aspects of some enzyme changes was obtained in respect to the number of envenomations. The biochemical alterations are partially reversible. The biochemically proven liver damage induced by VSE correlated well with previous electron microscopic observations of damage to mitochondria and cell membranes.

Alanine Transaminase↗