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Biomedical subjects

H Hoffmann

Publications and source records attributed to H Hoffmann.

At least 271 records · Page 15Linked to original sources
PubMed1981

Failing effect of digoxin on myocardial uptake of violamycin B1.

The effect of digoxin on both the negative inotropic action and the myocardial uptake of a new anthracycline antibiotic violamycin B1 has been studied in isolated guinea pig atria. In concentrations upto 2.0 X 10(-7) M/l digoxin did not prevent the negative inotropic effect of violamycin B1 caused by the concentrations of 0.7 and 5.0 X 10(-4) M/l. Corresponding to these findings, the uptake of violamycin B1 into the atrial tissue was not influenced by digoxin. However, violamycin B1 in the cardiotoxic concentration of 5.0 X 10(-4) M/l decreased the atrial uptake of digoxin. It is suggested that no competition seems to exist in myocardial uptake of anthracycline antibiotics and cardiac glycosides.

Aminoglycosides↗
PubMed1981

Toxic effects of violamycin Bi, carminomycin and daunorubicin on the myocardium of rabbits.

Cardiac toxicity of the new anthracycline antitumour antibiotics violamycin BI (V) and carminomycin (C) was studied in comparison with daunorubicin (D). Rabbits were intravenously given total doses of 0.1-1.5 mg/kg V or C, and 0.64-18 mg/kg D, respectively, twice weekly for one month. When examined two to six days, two and four weeks, respectively, after the last drug administration the gross findings consisted of hydropericard, hydrothorax and ascites in some animals. Histologically, loss of striation and focal necrosis of cardiac muscle cells and subsequently chronic inflammatory reactions and/or proliferation of mesenchyma cells were mostly found. These alterations were somewhat more pronounced in rabbits treated with V than in animals received D or C. At equitoxic doses of the antibiotics tested the ultrastructural lesion in the myocardial cells were altogether less marked after treatment with D than with C or V.

Aminoglycosides↗
PubMed1980

[Clearance determination with 131I-labelled hippurate (author's transl)].

The effect of the iodine not bound to the nuclear drug 131I hippurate on nuclear medical renal diagnosis by means of whole body clearance has been investigated. The results show that whatever clearance method is used, the tubular secretion performance decreases with increasing free iodine. This results in considerable error if the free iodine in the nuclear drug is not taken into account in the clearance calculation.

Adult↗
PubMed1980

Lysozyme (muramidase) and hemolytic complement (CH50U) in sera of beagle dogs and minipigs after longterm application of different preparations of estrogens and gestagens.

In studies for the chronic toxicity of estrogens and gestagens, lysozyme and hemolytic complement (CH50U) in sera of beagle dogs and minipigs were measured. Various doses of the sexsteroids were given: 0.01 mg, 0.1 mg and 1.0 mg/kg respectively. The influence of the steroids on the tested parameters after an application for 6 months was not significant, only in a single series with unphysiologically, high dosages of the preparations were some values changed significantly.

Animals↗
PubMed1980

Modification of toxicity of violamycin BI (VBI) by complex formation with DNA, metal ions, and by pretreatment with alpha-tocopherol.

In connection with studies on lowering the toxicity of violamycin BI (VBI) the intravenous (i.v.) LD50 values were determined in mice for VBI, VBI complexed with DNA, Fe3+ or Pt2+, and after pretreatment with alpha-tocopherol. The results indicate that the toxicity of VBI is reduced by complex formation with DNA or ferric ions including a partial decrease of the antimicrobial and antiviral activity.

Aminoglycosides↗
PubMed1980

Comparative studies on cardiotoxicity of some anthracycline antitumor antibiotics.

Isolated atria of guinea-pigs showed negative inotropic and negative chronotropic responses after violamycin B I (V), carminomycin (C) and daunomycin (D), respectively. The mean effective concentrations in reducing amplitude (IC50) were 5.9 x 10(-4) mol x 1(-1) for V and 1.3 x 10(-4) mol x 1(-1) for C and D. In rabbits, intravenous injections of different doses of the antibiotics twice weekly for one month produced histopathological alterations in the myocardial tissue, which were smaller after D than after C or V.

Animals↗
PubMed1980

Dietary influence on serum and urinary oxalate in healthy subjects and oxalate stone formers.

With a new enzymatic method, the dietary influence of oxalate, glycine, protein, and ascorbic acid on serum and urinary oxalate has been examined. Healthy and oxalate stone-forming subjects were compared. Two doses of sodium oxalate (130 and 400 mg daily) were administered. The high dose induced significant hyperoxaluria. No changes of serum oxalate were seen. Neither glycine (4.5 g daily) nor protein (50 g daily, 50% animal protein) had any effect on serum or urinary oxalate. Urinary oxalate excretion did not increase upon ingestion of large amounts of ascorbic acid (1--6 g daily), but serum oxalate levels were significantly elevated. The value of severe dietary restrictions concerning the compounds examined here seems to be questionable, as a significant increase of urinary oxalate excretion is lacking.

Ascorbic Acid↗
PubMed1979

[Partial effects of estrogens and 19-nortestoron derivatives].

In the present review the extragenital effects of steroidal estrogens and 19-norandrogen derivatives on mammalian organs and tissues are described. In detail experimental and clinical findings concerning the influence of these compounds on carbohydrate-, lipid- and protein metabolism, on the cardio-vascular system, the blood coagulation, the bone-tissue, the connective-tissue, the central nervous system and the immune system are summarised. These effects are mainly discussed as possible side effects and also as base for new therapeutic concepts.

Blood Coagulation↗