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Biomedical subjects

B Beck

Publications and source records attributed to B Beck.

At least 19 recordsLinked to original sources
PubMed1992

Enzyme activities of D-glucose metabolism in the fission yeast Schizosaccharomyces pombe.

The activities of key enzymes that are members of D-glucose metabolic pathways in Schizosaccharomyces pombe undergoing respirative, respirofermentative, and fermentative metabolisms are monitored. The steady-state activities of glycolytic enzymes, except phosphofructokinase, decrease with a reduced efficiency in D-glucose utilization by yeast continuous culture. On the other hand, the enzymic activities of pentose monophosphate pathway reach the maximum when the cell mass production of the cultures is optimum. Enzymes of tricarboxylate cycle exhibit the maximum activities at approximately the washout rate. The steady-state activity of pyruvate dehydrogenase complex increases rapidly when D-glucose is efficiently utilized. By comparison, the activity of pyruvate decarboxylase begins to increase only when ethanol production occurs. Depletion of dissolved oxygen suppresses the activity of pyruvate dehydrogenase complex but facilitates that of pyruvate decarboxylase. Acetate greatly enhances the acetyl CoA synthetase activity. Similarly, ethanol stimulates alcohol dehydrogenase and aldehyde dehydrogenase activities. Evidence for the existence of alcohol dehydrogenase isozymes in the fission yeast is presented.

Cell Division↗
PubMed1992

[Prospective examinations concerning the effect of exposure to aromatic hydrocarbons on health status].

The purpose of the study was to evaluate the general and toxicological status of footwear factory workers exposed to toluene, benzene and trace amounts of chromium. The subjects were 80 persons who worked with the glue, and were professionally exposed to aromatic hydrocarbons such as toluene and benzene AT amounts not exceeding the TLVs. The mean age of the subjects was 46.89 years and the mean period of work 20.26 years. Complete internal and neurological examinations were carried out. The following parameters were determined: hematocrit, hemoglobin, erythrocytes, leukocytes, platelets, reticulocytes, chromium, copper, zinc in serum and hippuric acid in urine (in 30 persons). In the examined group no changes in the leukocyte system were found. Two women had a lower hemoglobin level and erythrocyte count. In three persons thrombocytopenia was observed (3.75%). The mean metal levels in serum were within normal values. Only in 4 persons (5.0%) elevated levels of phenol in urine were found which indicated exposure to benzene. In 30 subjects (18 women and 12 men) (most exposed to toluene) the hippuric acid level in urine was examined. It was found to range from 130 mg/l to 2080 mg/l. In the control group not exposed to either of the solvents the level of hippuric acid in urine varied from 190 to 330 mg/l. There was little effect of aromatic hydrocarbons on hematopoiesis. The increased absorption of benzene or toluene found in the examined persons would indicate a necessity for biological monitoring of this group.

Benzene↗
PubMed1992

Chronic and continuous intracerebroventricular infusion of neuropeptide Y in Long-Evans rats mimics the feeding behaviour of obese Zucker rats.

Neuropeptide Y (NPY), a member of the pancreatic polypeptide family, strongly stimulates food intake when injected centrally in animals. It is found in abundance in the brain and particularly in areas involved in the regulation of feeding behaviour. Moreover, in these areas, NPY concentrations are higher in the obese hyperphagic Zucker rat. The aim of the present experiment was to reproduce in normal Long-Evans rats the high central levels of NPY measured in Zucker rats. We therefore continuously infused NPY in the brain lateral ventricle through osmotic mini-pumps and studied the effects of this infusion on different parameters of the feeding behaviour. Male adult Long-Evans rats were fed ad libitum on a high carbohydrate (HC) diet and on a high fat (HF) diet given simultaneously in two separate cups. NPY was infused at a rate of 0.44 micrograms/h (n = 11) and rats infused with artificial cerebrospinal fluid (n = 11) served as controls. The infusions lasted 14 days. Total food intake markedly increased in NPY infused rats starting on the first day after pump installation (33.7 +/- 1.7 vs. 14.8 +/- 0.6 g/day; P less than 0.0001). This effect lasted for nine days. In these rats, the average food intake during the infusion period (21.0 +/- 1.6 g/day) was also significantly greater than during the pre-infusion period (13.1 +/- 0.5 g/day; P less than 0.0001) and the post-infusion period (10.6 +/- 0.4 g/day; P less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Changes in hypothalamic neurotensin concentrations and food intake in rats fed a high fat diet.

Neurotensin (NT), a peptide present both in the brain and in the gastrointestinal tract, has potent anorexigenic effects when centrally injected in rats and is secreted after fat ingestion. High fat diets are often associated with increased energy intake. The aim of this study was therefore to evaluate the role of neurotensin in the feeding behaviour of rats fed on a high fat (HF) diet. Adult Long-Evans rats were fed for two weeks either a control (C) well-balanced diet (n = 10) or a fat-rich diet containing about two-thirds of its energy as fat (margarine and peanut oil; n = 10). Neurotensin was measured by a specific radioimmunoassay in the plasma and in several microdissected brain nuclei involved in the regulation of feeding behaviour. Ingestion of the HF diet induced an increased body weight gain (47.6 +/- 7.7 g (HF) vs. 37.6 +/- 9.3 g (C); P less than 0.05) and an increased energy intake (+ 7.2%; P less than 0.05). Plasma fasting NT concentrations were not affected by the HF diet. In the hypothalamus, significant decreases in NT concentrations were measured in the HF rats in two nuclei important in the regulation of food intake, i.e. the paraventricular nucleus (1.72 +/- 0.16 (HF) vs. 2.27 +/- 0.15 (C) ng/mg protein; P less than 0.05) and the lateral hypothalamus (1.87 +/- 0.16 (HF) vs. 2.37 +/- 0.19 (C) ng/mg protein; P less than 0.05). On the other hand, no variations were measured in the ventral tegmental area, an important site for the metabolism and regulatory action of neurotensin and in other hypothalamic nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

High molecular weight substances with insulin immunoreactivity.

Substances which react with anti-insulin antibodies, but have a higher molecular weight than insulin are described. They have been studied by various authors in pancreatic adenomas, pancreas extracts, serum and cell-free systems. Proinsulin was the first of these products to be discovered, followed by its precursor, pre-proinsulin, and subsequently by a whole series of substances of ill-defined composition and more or less similar properties, grouped under the heading of "high molecular weight immunoreactive insulin" (HWIRI).

Adenoma↗
PubMed1979

[Extrathoracic mesothelioma by inhalation of asbestos dust (author's transl)].

Report on 22 cases of malign peritoneal mesothelioma, their occupational, epidemiological, differentialdiagnostic, and oncologic aspects being discussed. For expert opinion the special criteria for acknowledging a peritoneal mesothelioma as an occupational disease are formulated (time and level to asbestos exposition, presence of pulmonary asbestosis and/or asbestos needles, latency time of about 20 years, and malignancy of the very often diffuse peritoneal mesothelioma).

Asbestos↗
PubMed1978

Inpatient audit simplified.

One hospital's audit program identifies the necessary procedures for selecting criteria, performing audits, and conducting follow-up and shows how they can be accomplished most effectively and efficiently. In addition, it shows that a useful emergency department/outpatient audit can be conducted using data from telephone follow-up for the patients.

Anti-Bacterial Agents↗
PubMed1978

[Oxygen consumption of the spontaneous and artificially induced skincycle at different times of day (author's transl)].

In the "clean" rat skin purified from the panniculus carnosus the oxygen consumption of the spontaneous and artificially induced skincycle was measured at different times of day. The level of oxygen consumption correlated to diurnal and nocturnal periods. During the skincycle the oxygen consumption showed fluctuations. There were indications that the value of oxygen consumption of the early anagen is influenced by that phase of the cycle at which the new cycle is artificially induced. Furthermore, it was found that a certain decrease of oxygen consumption stimulates the quiescent hair follicles to spontaneous proliferation. During the katagen the peak value of the oxygen consumption seemed to be correlated with specially morphofunctional perifollicular changes. The application of these findings to the pathophysiology of human hair growth disturbances is discussed.

Animals↗
PubMed1978

Cystic fibrosis: cell culture classes in a Danish population.

The cystic fibrosis (CF) culture phenotype of dermal fibroblasts (metachromasia, metabolic cooperation) of a group of 131 Danish CF patients and their families were studied to determine the distribution of the two CF culture classes and their prognostic significance. Of these, 62.6% (82) were Class I, 31.3% (41) Class II and 61.1% (8) were proposed to be genetic compounds. The occurrence of Class II was twice that found in a group of patients from New York (13%) and Minnesota (18%). The prognosis for Class II CF patients was considered to be poorer as: (1) The initial diagnosis was made earlier in Class II than in Class I or the compounds (63% of Class II were diagnosed in the first year of life, as compared to 35% in Class I and 13% of the compounds). (2) Only 5% of the Class II patients survived over the age of 15 years, both being deceased at the end of the study in 1976, whereas 24% of Class I and 63% of the compounds were over 15 years at the end of the study. This research added further evidence for genetic heterogeneity within the clinical syndrome, cystic fibrosis.

Age Factors↗
PubMed1978

Properties and subcellular distribution of acyl-CoA: cholesterol acyltransferase (ACAT) in guinea-pig liver.

The optimal in vivo conditions for measuring liver acyl-CoA:cholesterol acyltransferase, EC.2.2.1.26 (ACAT) activity in cytoplasmic extract from guinea-pigs have been examined. ACAT in liver from ordinarily fed guinea-pigs is very low. The effect of different compounds on ACAT activity was evaluated. Sodium fluoride, oligomycin, divalent cations, oleyl-CoA, and bile acids were all shown to inhibit ACAT activity markedly. Albumin stimulated the cholesterol esterification independently of the presence of fatty acids. Subcellular distribution of liver ACAT in relation to different marker enzymes shows that the bulk of ACAT activity is present in the microsomal fraction. By comparing the esterification of exogenous and endogenous cholesterol, the results indicate that these two substrates are not esterified to the same extent. Both the 'enzyme" level and substrate quality are of importance for the high ACAT activity found in rat-liver homogenates compared to guinea-pig.

Acyl Coenzyme A↗
PubMed1977

Pseudomonas aeruginosa infection in cystic fibrosis. Diagnostic and prognostic significance of Pseudomonas aeruginosa precipitins determined by means of crossed immunoelectrophoresis.

A total of 133 patients with cystic fibrosis have been followed for up to 5 years with monthly examinations including bacteriological examinations of sputum. Sera from the patients were examined by means of crossed immunoelectrophoresis for the occurence and number of precipitating antibody specificites against Pseudomonas aeruginosa. Poor prognosis in cystic fibrosis was associated with chronic colonization (9 months - more than 5 years) of the respiratory tract with mucoid Pseudomonas aeruginosa, and with an onset of the chronic colonization before puberty. Among the patients with chronic Pseudomonas aeruginosa colonization, poor prognosis was associated with high numbers of precipitins against antigens from these bacteria (up to 61). The number of Pseudomonas aeruginosa precipitins increased on an average with five per year in chronically colonized patients. Rapidly increasing number of precipitins was associated with poor prognosis. Patients with any degree of impairment of the ventilatory function and any changes on the chest radiographs could contract chronic Pseudomonas aeruginosa colonization. Poor ventilatory function and severe changes on the chest radiographs was associated with high numbers of Pseudomonas aeruginosa precipitins and with poor prognosis. Although many O groups of Pseudomonas aeruginosa were found in the chronically colonized group of patients, 53% of the patients harboured strains belonging to O group 3 or 3/9, and the highest numbers of precipitins were found in serum from these patients.

Antibodies, Bacterial↗
PubMed1976

[Silicosis and scleroderma--attempt at synopsis].

Progressive systemic sclerosis obviously more frequently appears in men working under silica dust exposure than in professionally not selected groups. Moreover, silicosis and sclerosis frequently occur combined. Pathogenetic association with regard to immunologic patterns may give an explanation for this phenomenon. Sclerosis occuring in the course of silicosis ought to be included when impairment for compensation purposes is taken into consideration.

Antibody Formation↗