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Biomedical subjects

B Hesse

Publications and source records attributed to B Hesse.

At least 109 records · Page 6Linked to original sources

Skin tumor formation in the European hamster (Cricetus cricetus L.) after topical initiation with 7,12-dimethylbenz[a]anthracene (DMBA) and promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA).

Initiation with the carcinogen 7,12-dimethylbenz[a]anthracene followed by promotion with the hyperplasiogenic phorbol ester 12-O-tetradecanoylphorbol-13-acetate carried out on the dorsal skin of European hamsters (Cricetus cricetus L.) led to the formation of a broad spectrum of skin tumors in terms of a two-stage principle. Tumor formation involved the epidermis and its appendages, the connective tissue, and the vascular and pigmentary system. With regard to the sensitivity to initiation with DMBA alone and initiation with DMBA and promotion with TPA the European hamster occupies a special position since all of the DMBA-TPA sensitive two-stage target organs known from the mouse, rabbit, Syrian golden hamster and rat are combined in this animal.

9,10-Dimethyl-1,2-benzanthracene↗

Evaluation of intravenous radionuclide angiography in detection of occlusive disease of the iliac arteries.

Radionuclide angiography (angioscintigraphy) of the iliac arteries was performed in 173 patients consecutively referred for arterial insufficiency of the legs. In 83 of the patients femoral angiography was also performed. The interobserver variation was evaluated by the agreement indices, kappa (K) and weighted kappa (Kw). For angiography the interobserver agreement was high (K and Kw 0.65 and 0.77 respectively). For angioscintigraphy the agreement between observers was fair (K = 0.52, Kw = 0.68), and equal to the intraobserver agreement (K = 0.55, Kw = 0.65). The comparison between angioscintigraphy and angiography gave K-values of 0.22-0.31 and Kw-values of 0.37-0.48. The nosographic sensitivity of angioscintigraphy was 61%, the nosographic specificity was 93%, and the predictive value for both a positive and a negative test was 83%. The prevalence of occlusion or severe stenosis was 34%. Inguinal pulse palpation detected 48% of iliac occlusions. It is concluded that the reliability of angioscintigraphy in the diagnosis of iliac arterial occlusive disease is acceptable for a non-invasive, rapid, inexpensive and widely available screening procedure. Although anatomical details are not visualized the information obtained is useful for the detailed planning and choice of subsequent diagnostic and therapeutic procedures. The method is well suited for repeat studies and may be modified to include the femoral arteries.

Adult↗

The influence of ACE-inhibition by captopril on renal formation and metabolism of angiotensins I and II in patients with renovascular hypertension.

Fourteen patients with hypertension of presumed renovascular etiology were studied by renal vein catheterization. Unilateral renin secretion was found in 8 patients. In 4 of these patients a positive veno-arterial difference of plasma angiotensin I concentration (PAI) across the affected kidney increased markedly after a single dose of captopril. Across the contralateral kidney the net veno-arterial PAI difference changed from about zero before captopril to clearly negative values after captopril. The PAI values in the remaining 4 patients, who were already on captopril before the catheterization, were similar to those observed after a single dose of captopril. In patients with bilateral renin secretion the renal veno-arterial PAI differences across the kidneys were positive or close to zero before captopril. After captopril both positive and negative veno-arterial differences of PAI were observed. The plasma angiotensin II concentrations decreased after captopril to low values. These low values together with extremely high PAI values demonstrate effective ACE-inhibition. A high generation rate of angiotensin I in the affected kidney in patients with unilateral renin secretion after captopril is probably explained by activation of the local renin secretion. The angiotensin I "consumption" in the contralateral kidney after captopril in spite of no angiotensin II formation suggests the presence of alternative degradation processes for angiotensin I in the human kidney.

Adult↗

Haemodynamic and clinical effects of isosorbide-dinitrate in patients with severe effort angina on beta-blocking treatment.

The effect of isosorbide-dinitrate (ISDN) 20 mg 4 times daily against placebo has been tested in 12 patients with stable effort induced angina pectoris receiving prophylactic treatment with metoprolol. ISDN did not decrease the attack rate or nitroglycerine consumption, nor was exercise tolerance increased after it. Left ventricular function, assessed by radionuclide ventriculography, increased in 6 out of 8 patients (p less than 0.1). It is concluded that ISDN has no place in the treatment of haemodynamically intact patients with severe angina pectoris in spite of beta-blocking treatment, but that it may be of value in the treatment of patients with left ventricular failure, including those whose left ventricular failure has been brought about by beta-blocking treatment necessitated by angina pectoris.

Adult↗

Electrolyte and glucose metabolism in VX-2 carcinoma of the rabbit.

Biochemical and other parameters in VX-2 carcinoma in rabbits were evaluated. VX-2 carcinoma not only produced hypercalcemia but also hypophosphatemia and 25-OH-vitamin D deficiency. An increased turnover of 25-OH-vitamin D seems likely. Serum parathyroid hormone and urinary cyclic AMP did not increase. Hypokalemia occurred in association with hypophosphatemia and lowered blood glucose within 1 week after tumor transplantation. At the end of the experiment glucose and insulin were both below the control range. It is concluded that VX-2 carcinoma in rabbits yields much more complex biochemical alterations than reported before on calcium metabolism.

Animals↗

On the persistence of tumor initiation in two-stage carcinogenesis on mouse skin.

The persistence of the initiated state during two-step carcinogenesis in mouse epidermis is a generally accepted phenomenon, however, conflicting results exist with regard to the degree of irreversibility relative to the age of the animals. Several factors such as age-dependent alterations in the response of the epidermis to the promoter and skin damage following the initiation step have been proposed to account for the observed discrepancies. In the present investigation we have tried to circumvent skin-damaging effects of topically applied 7,12-dimethylbenz[a]anthracene by intragastric administration of the drug. Tumor production by topical promotion with 12-O-tetradecanoylphorbol-13-acetate was subsequently determined in 600 female NMRI mice using intervals of 4, 8, 16, 24, 32 and 40 weeks between initiation and promotion. Independent of the delay between the initiating and promoting step, we observed a similar time course and extent of tumor production in the different experimental groups. This indirectly proves that the promoting capacity of 12-O-tetradecanoylphorbol-13-acetate is age-independent and that during aging no substantial loss of initiated cells occurs in mouse epidermis.

9,10-Dimethyl-1,2-benzanthracene↗

Generation and elimination of angiotensins I and II in the kidney, liver and lung.

Inflow and outflow concentrations of angiotensins I (AI) and II (AII) from both kidneys, the liver and the lung were measured in 30 hypertensive patients, the majority having lateralization of the renin secretion. In the renin secreting kidney the data indicated a high generation rate of AI. In the contralateral kidney and splanchnic region both AI and AII were 'eliminated', and in the lungs the results confirmed previous evidence of converting enzyme activity.

Adolescent↗

[Results of the Maquet/Bandi tibial tuberosity ventralization].

From 1975 to summer 1980, 87 patients suffering from chondropathy of the patella underwent 95 operations according to the method of Maquet-Bandi. 79 patients could be followed up 1,5 year after the operation. Additional procedures for restoring the knee joint had to be performed in 54 cases. The results obtained were good in 83%.

Adolescent↗

Effects of antimalarial drugs on several rat-liver lysosomal enzymes involved in phosphatidylethanolamine catabolism.

The effects of three cationic amphiphilic antimalarial drugs (chloroquine, mepacrine and primaquine) on the intralysosomal catabolism of phosphatidylethanolamine and several of its metabolites were studied with rat-liver lysosomes which had been isolated from animals previously treated with Triton WR-1339. The activities of each of the various enzymes involved in the main pathways of intralysosomal phosphatidylethanolamine degradation (Kunze, H., Hesse, B. and Bohn, E. (1982) Biochim. Biophys. Acta 711, 10-18) exhibited almost identical inhibitory sensitivities towards mepacrine and primaquine. In contrast, chloroquine inhibited the activities of the various enzymes to different extents, lysophospholipid acylhydrolase (EC 3.1.1.5) being the most sensitive enzyme, followed by phospholipase A1 (EC 3.1.1.32) and monoacylglycerol lipase, and eventually lysophospholipid monoacylglycerol hydrolase as the least sensitive enzyme. The relative inhibitory potencies towards phospholipase A1 activity of chloroquine were increased with increasing pH, and the mode of inhibition was competitive. In contrast, the inhibitory potencies towards monoacylglycerol lipase activity of chloroquine increased only up to pH 5 but decreased above this value, and the mode of inhibition was noncompetitive.

Animals↗

Hydrolytic degradation of phosphatidylethanolamine and phosphatidylcholine by isolated rat-liver lysosomes.

Lysosomal catabolism of radioactively labelled phosphatidylethanolamine, phosphatidylcholine and several potential metabolites of these diacylphospholipids was studied using rat-liver lysosomes which had been isolated from Triton WR-1339-treated animals. Hydrolysis of these lipids seems to be restricted to the soluble lysosomal compartment. The initial intralysosomal degradation is predominantly catalysed by phospholipase A1 (EC 3.1.1.32) followed by lysophospholipase (EC 3.1.1.5). The end products of this pathway are free fatty acids and glycerophosphorylethanolamine or glycerophosphorylcholine. These phosphodiesters are not hydrolysed further in lysosomes, as has been shown previously (Fowler, S. and De Duve, C. (1969) J. Biol. Chem. 144, 471-481). The intermediary lysophospholipids, however, are also hydrolysed by an alternative pathway, i.e. by a lysophospholipase which catalyses the hydrolysis of the glycerophosphate ester bond, followed by a monoacylglycerol lipase and a phosphomonoesterase (EC 3.1.3.2), respectively. Besides these two catabolic routes of intralysosomal hydrolysis of phosphatidylethanolamine and phosphatidylcholine, additional pathways are possible, which seem, however, to be of minor importance, at least in the substrate concentration ranges employed in these studies. These additional reactions include attack by a phospholipase A2 (EC 3.1.1.4) and--as discovered recently (Matsuzawa, Y. and Hostetler, K.Y. (1980) J. Biol. Chem. 255, 646-652)--by a phospholipase C (EC 3.1.4.3). Cations such as Mg2+, Ca2+, K+ and Na+ inhibit preferentially deacylation reactions.

Animals↗