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Biomedical subjects

F Weber

Publications and source records attributed to F Weber.

At least 253 records · Page 14Linked to original sources
PubMed1984

Uptake of ascorbic acid by human granulocytes.

The uptake of ascorbic acid by isolated human granulocytes is investigated under different conditions. The rate of uptake depends on the concentration of ascorbic acid in the incubation medium as well as on temperature, with a maximum at 40 degrees C. At 0 degrees C no uptake can be observed. N-formylated peptides being known to stimulate human granulocytes, considerably increase ascorbic acid uptake, but the non-formylated methionyl-leucyl-phenylalanine is without effect. Glucose is a strong inhibitor of ascorbate uptake with a Ki of 3.7 mM and a stoichiometry of 1:1. Fructose does not inhibit at all and galactose only at elevated concentrations. Phlorizin, a known inhibitor of glucose transport, inhibits the uptake of ascorbic acid to the same extent as that of glucose. Elevated glucose levels do not induce a release of ascorbic acid out of the cells. It is concluded that ascorbic acid is actively accumulated in human granulocytes and that stimulated cells respond with a pronounced increase of ascorbate uptake. The site of ascorbic acid transport across the membrane is probably the same as of glucose.

Ascorbic Acid↗
PubMed1983

Association between transplantation antigens and a viral membrane protein synthesized from a mammalian expression vector.

Cells infected or transformed by adenovirus-2 express complexes of the viral E19 protein and class I transplantation antigens. To eliminate the complication of the numerous metabolic changes in adenovirus-infected and -transformed cells, we detached the E19 gene from its viral background by constructing transient expression vectors where the E19 coding sequence is flanked by the SV40 early promoter and the 3' region of the rabbit beta-globulin gene. E19 production was assayed 2 days after transfection of monkey COS or human HeLa cells with vector DNA. Efficient E19 gene expression depends on the presence of an intron (the second beta-globin intron), and the E19 protein is properly processed and anchored in the plasma membrane of transfected cells. The vector-synthesized E19 protein is also associated with class I transplantation antigens in human cells, since a fraction of it is coprecipitated both with antiserum against HLA antigens and with monoclonal antibodies against beta 2-microglobulin.

Adenoviridae↗
PubMed1983

Effects of a high-complex-carbohydrate, low-fat diet and daily exercise on individuals 70 years of age and older.

Data were obtained from 70 individuals (M age = 78.7, SE = 4.1 years) who attended the Pritikin Longevity Center's 26-day residential program where they were exposed to a high-complex-carbohydrate, low-fat diet, and daily exercise. During the 26-day program, serum cholesterol was reduced from 222 (SE = 5) to 179 (SE = 5) mg/dl, and triglycerides were reduced from 156 (SE = 10) to 141 (SE = 7) mg/dl. Body weight was reduced an average of 2.2 kg. Treadmill performance increased from 3.7 (SE = .1) to 5.5 (SE = .2) METs. During the final week of the program, average daily walking was 5.1 (SE = .3) km. Forty-six hypertensive patients reduced their pressure from 154/80 to 150/77 mmHg, with 9 of 18 patients discontinuing their antihypertensive medication. Thirteen type II diabetic patients reduced their fasting serum glucose from 164 (SE = 4) to 120 (SE = 2) mg/dl.

Aged↗
PubMed1983

Subclassification of human beta-adrenergic receptors mediating renin release.

To determine the beta-adrenoceptor subtype controlling renin release from the kidneys, several beta-adrenoceptor subtype selective agonists and antagonists were administered to 15 healthy volunteers. While isoprenaline infusion (1, 2 and 4 micrograms/min for 5 min each) markedly increased plasma renin activity (PRA), the beta 2-selective agonist fenoterol failed to change PRA. The isoprenaline induced rise in PRA could be completely prevented by the beta 1-selective antagonists metoprolol (10 mg i.v. 45 min prior to isoprenaline infusion) and betaxolol (5 mg i.v. 45 min prior to infusion) indicating that renin release is mediated by beta 1-adrenoceptors. Binding studies with the highly specific beta-adrenoceptor radioligand (+/-)-125iodocyanopindolol demonstrated that membranes from human kidney cortical slices contain predominantly, if not exclusively, beta 1-adrenoceptors. These in vivo and in vitro results support the view that the beta-adrenoceptor mediating renin release from the human kidney is of the beta 1-subtype.

Adrenergic beta-Agonists↗
PubMed1983

[The cerebral lesions in congenital toxoplasmosis. Study of 9 personal cases and 61 cases in the literature].

This study is a review of 70 cases of congenital toxoplasmosis; all of the patients were dead between birth and the age of nine. The anatomo-pathological examination of 9 personal cases (6 acute, 1 subacute, 2 chronic) is presented and compared with that of 61 cases from the literature. After a parasitological survey concerning the infectious agent, the author summarizes the macroscopic and the microscopic lesions of his personal cases. Those data are subsequently confronted to those referred to in the literature. The author makes an attempt to entangle the terminological confusion that exists between the different terms: cyst, pseudocyst, microglial nodule and granuloma. The frequency, the localization and the mechanisms of the main alterations - granuloma, necrosis, calcification, hydrocephaly - are studied as well as the vulnerability factors and the resistance of the subjects. The presence in 8 of the 9 chronic cases of calcified scar lesions in the inferior portion of the external wall of the lateral ventricles suggests a particular vulnerability of the spongioblasts in that area. In the acute cases the extensive necroses in the cerebral hemispheres seem to result from immunological reactions in an immature organism rather than from vascular thromboses that appear to be more a secondary phenomenon.

Acute Disease↗
PubMed1982

Catecholamines, growth hormone, cortisol, insulin, and sex hormones in anaerobic and aerobic exercise.

Seventeen male physical education students performed three types of treadmill exercise: (1) progressive exercise to exhaustion, (2) prolonged exercise of 50 min duration at the anaerobic threshold of 4 mmol . l-1 blood lactate (AE), (3) a single bout of short-term high-intensity exercise at 156% of maximal exercise capacity in the progressive test, leading to exhaustion within 1.5 min (ANE). Immediately before and after ANE and before, during, and after AE adrenaline, noradrenaline, growth hormone, cortisol, insulin, testosterone, and oestradiol were determined in venous blood, and glucose and lactate were determined in arterialized blood from the earlobe. Adrenaline and noradrenaline increased 15 fold during ANE and 3--4 fold and 6--9 fold respectively during AE. The adrenaline/noradrenaline ratio was 1 : 3 during ANE and 1 : 10 during AE. Cortisol increased by 35% in ANE (12% of which appeared in the postexercise period) and 54% in AE. Insulin increased during ANE but decreased during AE. Testosterone and oestradiol increased by 14% and 16% during ANE and by 22% and 28% during AE. The results point to a markedly higher emotional stress and higher sympatho-adrenal activity in anaerobic exercise. Growth hormone and cortisol appear to be the more affected by intense prolonged exercise. Taking plasma volume changes and changes of metabolic clearance rates into consideration, neither of the exercise tests appeared to affect secretion of testosterone and oestradiol.

Adult↗
PubMed1982

[Alterations of sleep stage patterns in humans and carry-over effects under estazolam / 1st comm.: effects of estazolam on sleep disturbed by jet fly-over noise (author's transl)].

Effects of the benzodiazepine derivative 8-chloro-6-phenyl-4H-s-triazolo(4,3-a)-(1,4)benzodiazepine (estazolam, BAY k 4200) on sleep stage patterns of 10 subjects were studied in the laboratory under double-blind conditions during quiet and noise-disturbed nights. The noise of 17-20 jet fly-overs was presented during sleep. The mean peak level of the noise was 97 dB(A) measured indoors near the sleeper's head. Intermittent wakefulness, stage 1 and movement time (MT) increased during noise-disturbed nights. Estazolam suppressed the phases of intermittent wakefulness during the quiet night and reduced stage 1 and MT. Arousal reactions by jet noise were milder and shorter under estazolam. Both effects resulted in equal amounts of intermittent wakefulness, stage 1 and MT during the noise-disturbed night under estazolam and during the quiet night under placebo. The dosage of 2 mg estazolam had no significant effect on stage REM, but delta-sleep decreased. Hints of carry-over effects were found in the sleep stage patterns. Effects of estazolam were seen in the estimations of sleep quality and mood by the subjects in the morning after awakening.

Adult↗
PubMed1982

[Simultaneous cutaneous and choroidal melanomas (author's transl)].

In patients with both cutaneous and ocular malignant melanomas it is most important for prognosis and therapy to know whether they are distinct tumors developing simultaneously or whether one of the tumors represents a metastasis of the other. In the case reported here, two distinct tumours developed independently from pre-existing benign melanocytic lesions. Cases of this type, which are extremely rare, are discussed as well as the differential diagnosis between primary choroidal malignant melanoma and choroidal metastases from melanomas of different origin.

Choroid Neoplasms↗
PubMed1982

Acute endocarditis in drug addicts: surgical treatment for gram-negative sepsis.

We studied 37 consecutive patients, all drug addicts, who underwent 48 valve operations from 1976 through 1981. GN bacteria were the major organisms in 25 patients (64%), compared with a previous reported incidence of 10%. Operative indications were uncontrolled sepsis in 49%, embolism in 27% and heart failure in 24% of the patients. Primary operations included nine tricuspid valvectomies and 14 aortic, 10 mitral and four aortic/mitral valve replacements. Early (30-day) mortality was 2.7% (one of 37 patients); five of nine patients who had 11 reoperations survived. Long-term follow-up revealed a late mortality of 39% (11 of 28) in patients with left-sided disease; eight of the 11 patients who died had GN infection with perivalvular abscess. Thus, the subgroup with GN sepsis and left-sided disease had a combined early and late mortality of 50%, with all deaths occurring within 8 months postoperatively. We conclude that valve replacement in the presence of active sepsis can be safely performed, but GN sepsis in addicts increases the risk of early reinfection and late mortality.

Acute Disease↗