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Biomedical subjects

I Weiss

Publications and source records attributed to I Weiss.

At least 55 records · Page 3Linked to original sources
PubMed1976

Effects of in vivo administered B. pertussis and other adjuvants on the mitotic responses of lymphocytes in vitro.

Intraperitoneal treatment of mice with adjuvants affects the in vitro response of their lymphocytes toward class-specific mitogen. Spleen cells from animals injected with Corynebacterium parvum organisms showed in some cases an increase in their response to all mitogens, while in other experiments, a moderate decrease in the reaction to T-specific mitogens (concanavalin A and phytohemagglutinin) was found. Injection of lipopolysaccharide (LPS) and in particular Bordetella pertussis bacteria, brought about a marked reduction in the response of spleen cells to B mitogens (LPS and PPD) but had little or no effect on the reaction to the T mitogens. Intraperitoneal administration of B. pertussis caused a marked depletion of lymph nodes and a high level of lymphocytosis. Blood cells of the treated mice showed an increased response to T mitogens, whereas mesenterial lymph node cultures reacted higher than the controls to LPS and without stimulation. No change was noted in the responses of cells from the axillary lymph nodes of these pertussis-treated mice.

Adjuvants, Immunologic↗
PubMed1975

[Ribonuclease activity following partial hepatectomy in the liver of healthy and alloxan diabetic rats and histological findings in the islets of Langerhans (author's transl)].

QUESTION: What changes in the level of ribonuclease activity (RNase activity) can be observed in the regenerating liver of healthy and alloxan diabetic rats following partial hepatectomy? What coincidental alterations of the ratio A-cells to B-cells do occur in the islets of Langerhans? MATERIALS AND METHODS: 120 male Wistar rats of averagely 180 g body weight were fed a standard diet ("Rehbrücke") with drinking water ad libitum. After deprivation of food for 15 hours the animals were sacrificed by heart puncture under ether anesthesia. The caudal part of the body was rinsed free from blood by ice-cooled physiological saline via the aorta. After removal of the livers each 2 g of liver tissue were homogenized in 0.25 M saccharose or 70% ethyl alcohol. For the study of impairment of ribonuclease activity in the liver following different lesions the animals were divided into 3 test groups of 35 animals each: group 1: alloxan diabetes; group 2: liver regeneration after partial hepatectomy; group 3: alloxan diabetes in combination with liver regeneration after partial hepatectomy. From each group always 4 to 6 animals were sacrificed at the following time intervals: 2nd day and 4th day as well as after 3, 4 and 6 weeks. In 8 animals the enzymatic activity was not influenced. RNA content and dry weight of the livers of all test animals were determined. In liver homogenates with saccharose the ribonuclease activity was measured according to the method of FIERS (1961) using highly purified yeast RNA for substrate. This technique is especially suitable for raw tissue homogenates. After 30 min incubation at 37 degrees C and precipitation of the high-molecular polynucleotides as well as of protein by means of methylglycol and barium perchlorate the not precipitable low-molecular oligonucleotides which were produced by ribonuclease action, were spectrophotometrically measured in the supernatant at 260 nm. The deltaE-value was calculated for the employed quantity of RNA related to mg of protein brought into action. Demonstration and determination of the ribonuclease inhibitor was abandoned. Two different RNA substrate concentrations were used; in the higher concentration the activity was measured at pH 5.5 to 6 and 7.5, in the lower concentrations at pH 7. Protein measurement was performed after the method of LOWREY (LOWREY et al. 1951) as modified by GLASER and KLEINE (1962); blood sugar was determined in tail vein blood by means of o-toluidine technique. In the liver homogenate with ethyl alcohol the RNA extraction was modified according to the data given by OGUR and ROSEN (1950); RNA determination was done colorimetrically using orcin hydrochloric acid. For dry weight determination the same homogenate was used. Alloxan diabetes was induced by injecting the rats 175 mg/kg b.w. of alloxan after fasting for 24 hours. The 5% alloxan solution in citrate buffer (pH = 4) was prepared immediately before injection. For further experimentation only those animals with blood sugar values of greater than 300 mg/100 ml were employed...

Animals↗
PubMedDate not supplied

In vitro pancreatic B-cell response of hyperinsulinemic rats. Differences between pregnancy and VMH-lesions.

We investigated in vitro the pancreatic B-cell response of hyperinsulinemic animals compared to that of controls with the aim of clarifying if the hyperinsulinemia is related to an alteration of the islet insulin secretion. Hyperinsulinemia was induced by pregnancy (observation at 19.5 days) and electrolytic lesions of the hypothalamic nucleus ventromedialis (2 days after lesion). The kinetics of the glucose dose/response curves (measured during a 60 min incubation period) differed markedly in the two hyperinsulinemic conditions. Whereas the islets from pregnant rats were characterized by a lowered glucose threshold, an enhanced half-maximal and maximal secretion rate, those of lesioned rats showed only an increased half-maximal and maximal secretion response in spite of a comparable islet insulin content. When culturing islets of hyperinsulinemic animals up to 6 days, the insulin secretion of those prepared from VMH-lesioned rats behaved identically to controls, whereas the islets of pregnant rats maintained their enhanced sensitivity at a glucose concentration of 5 mmol/l. These results confirm that the pancreatic B-cell response contributed significantly to the hyperinsulinemia, but different mechanisms are likely to be responsible for the altered B-cell secretion.

Animals↗
PubMedDate not supplied

Comorbid anxiety and affective disorder in alcohol-dependent patients seeking treatment: the first Multicentre Study in Germany.

The goals of this study were to describe demographic variables, drinking history, and the 6-month prevalence of Axis I comorbidity among alcohol-dependent subjects in GERMANY: The variables: amount of alcohol consumption, age at onset of the first alcohol consumed, age at onset of daily alcohol consumption, age at onset of withdrawal symptoms and number of detoxifications were related to the different comorbid disorders and gender. In this study, 556 patients from 25 alcohol treatment centres were enrolled between 1 January 1999 and 30 April 1999. After a minimum of 10 days of sobriety patients who fulfilled ICD-10 and DSM-IV criteria of alcohol dependence were interviewed for data collection using the Mini-DIPS (German version of the Anxiety Disorders Interview Schedule) and a standardized psychosocial interview. The 6-month prevalence of comorbid Axis I disorders was 53.1%. Among the patients with comorbidity, affective and anxiety disorders were most frequent. Comorbid stress disorder was associated with an early start of drinking, an early beginning of withdrawal symptoms, highest number of detoxifications, and the highest amount of alcohol consumed. Female patients with anxiety disorder consumed more alcohol and started earlier than females without this comorbid disorder. The data do not answer the question of the pathogenesis of comorbid disorders and alcoholism, but indicate that stress disorders in alcoholic patients and anxiety disorders in female alcoholics influence the course and severity of alcoholism.

Adult↗