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Biomedical subjects

U Widmer

Publications and source records attributed to U Widmer.

54 records · Page 3Linked to original sources

[Are cephalosporins more active than penicillin G in poisoning with the deadly Amanita?].

High dose penicillin-G has been found empirically to be effective against liver cell damage in amanita mushroom poisoning. We have recently found that betalactam antibiotics inhibit eukaryotic DNA polymerase-alpha, penicillins being more active than cephalosporins, and this may explain the antagonistic effect of penicillin-G against amanitin toxicity. Preliminary experiments in liver cell cultures and in mice are summarized, as well as first clinical experience pointing to the possibility that cephalosporins may be more effective against amanita mushroom toxicity than penicillin-G.

Animals↗

Effects of insulin-like growth factors on chick embryo hepatocytes.

Biological effects of insulin-like growth factors (IGF) I and II on primary cultures of chick embryo liver cells have been investigated and compared 1) with the biological effect of insulin and 2) with competitive binding of the three hormones to their respective binding sites. IGF I and II stimulate the incorporation of D[U-14C]-glucose into liver cell glycogen in a time- and dose-dependent manner, but with a 5-10-fold lower potency than insulin. Both IGFs also lead to enhanced incorporation of 5-[3H]uridine and L[U-14C]valine into trichloroacetic acid (TCA) insoluble material and to activation of ornithine decarboxylase activity. Their potency in stimulating RNA synthesis and ornithine decarboxylase activity is comparable to that of insulin. Protein synthesis is maximally stimulated at 3 nM by all three hormones. In the competitive binding studies, IGF I and II are 10-fold less potent than insulin in competing for [125I]insulin binding, but 100-fold more potent than insulin in competing for [125I]IGF I or II binding. These studies show that IGF I and II stimulate the same metabolic indices as insulin in the chick embryo liver. By comparing these biological effects with competitive binding data it appears that IGFs act on glucose metabolism in the chick embryo liver via the insulin receptor, whereas stimulation of growth indices by IGFs and insulin appears to be mediated by their own specific receptors.

Animals↗

Is extrapancreatic tumor hypoglycemia associated with elevated levels of insulin-like growth factor II?

We have tried to answer the still controversial question of whether or not extrapancreatic tumor hypoglycemia is associated with elevated levels of insulin-like growth factor II (IGF II), keeping in mind that controversial results may be due to methodological differences. Serum levels of IGF II were determined by a rat liver membrane radioreceptor assay and by RIA. Serum samples were gel filtered at acidic pH, and some sera were also tested after acid-ethanol extraction as an alternative method for dissociating and separating IGF from the IGF carrier protein. Additionally, the radioreceptor assay was performed with a labeled partially purified IGF preparation [nonsuppressible insulin-like activity soluble in acid-ethanol (NSILA-s "70")] that was used by a group reporting elevated NSILA-s levels in about 40% of their patients with tumor hypoglycemia. Mean serum levels of receptor-reactive IGF II and immunoreactive IGF II (+/- SD) were 436 +/- 169 and 540 +/- 256 ng/ml in 22 patients with tumor hypoglycemia, as compared with 578 +/- 155 and 647 +/- 217 ng/ml in 28 normal adults. This pattern of slightly, but not significantly lower mean IGF II values in tumor hypoglycemia was unchanged when a less pure IGF preparation (NSILA-s 70) was used as a tracer or when the sera were extracted with acid-ethanol. Thus, hypoglycemia resulting from extrapancreatic tumors is not likely to be associated with increased receptorreactive or immunoreactive IGF II levels.

Adolescent↗

[Pheochromocytoma in childhood. Report of a case of a familial type in an 8-year-old boy].

A case of right adrenal pheochromocytoma in an 8-yr-old boy and its successful surgical management are described. Clinical and statistical data are given for this form and its symptomatology and aetiopathogenesis are illustrated. Particular stress is laid on the occasionally misunderstood importance of the part played by continuous hypertension. Early diagnosis and surgery are essential to avoid the onset of serious cardiocirclatory complications.

Adrenal Gland Neoplasms↗

[The behavior of the hospitalized child awaiting a surgical operation].

The literature and personal experience are referred to in an assessment of psycho-affective situations in hospitalised children awaiting non-emergency surgery (appendicectomy, adenotonsillectomy, inguinal hernia, phymosis, hypospadias, cryptorchidism). Psychological and somatic damage resulting from an absence of preparation before hospitalisation and during admission immediately prior to surgery is described. A method whereby this may be avoided as far as possible with the aid of relatives is described.

Affective Symptoms↗

Native and prosthetic valve endocarditis caused by Rothia dentocariosa: diagnostic and therapeutic considerations.

Three cases, one each of native valve, prosthetic valve and composite graft endocarditis caused by Rothia dentocariosa are described. The first patient presented with multiple brain abscesses and severe congestive heart failure due to destructive endocarditis with large vegetations on the mitral valve. He died shortly after emergency valve replacement. Gram-positive coccoid rods were identified in the vegetations of the excised mitral valve. The second patient had a R. dentocariosa endocarditis of a prosthetic aortic valve that was treated empirically with netilmicin and teicoplanin, due to an allergy to penicillin. Both antibiotics were replaced according to susceptibility testing in vitro with rifampin and ciprofloxacin, and the endocarditis was cured within 9 weeks. The third patient presented with a circular root abscess of an aortic composite graft that was successfully treated with rifampin and ceftriaxone without surgery. All patients had extensive periodontal disease which was thought to be responsible for hematogenic spread and seeding of the microorganism. The microbiological identification and antibiotic resistance pattern of the isolates, as well as therapeutic implications are discussed.

Actinomycetales↗