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Biomedical subjects

M Hermann

Publications and source records attributed to M Hermann.

At least 217 records · Page 12Linked to original sources
PubMed1980

Adaptation of the salmonella/mammalian microsome test to the determination of the mutagenic properties of mineral oils.

Two techniques allowing the determination of the mutagenicity of lipophilic compounds such as mineral oils with the Ames test have been developed by using benzo[a]pyrene (BP) dissolved in white oil as a synthetic reference oil. The first technique involves prior extraction of polynuclear aromatic hydrocarbons (PAH) with dimethyl sulfoxide. In the second method, which proved simpler and of more general use, the compounds to be tested are directly dispersed in aqueous medium with Tween 80. The use of these techniques made possible the study of mutagenicity of various kinds of mineral oil. Mutagenic activity was found in used crankcase oils, and also in petroleum distillates but much less in solvent-refined oils. A good correlation was observed between mutagenic activity and PAH content but not BP content of oils. Because of their peculiar response to the test, petroleum distillates were studied in more detail. When added in low amounts to pure PAH compounds such as BP, they enhanced its mutagenic activity (enhancement). When added in higher amounts, on the contrary, these oils completely inhibited BP mutagenic activity (inhibition effect). Both effects correlated well with the PAH content and the mutagenic activity of the petroleum distillates tested. These results explain the abnormal dose-response curves curves obtained with these petroleum distillates and the negative results regarding their mutagenic activity reported in earlier studies. A likely explanation is discussed for the enhancement and inhibition effects.

Dose-Response Relationship, Drug↗
PubMed1979

Fertility factors in Pseudomonas putida: selection and properties of high-frequency transfer and chromosome donors.

The octane plasmid (OCT) in Pseudomonas putida strains has been shown to be transferred at low frequency. However, bacteria which had newly received this plasmid showed a transient increase in donor ability. Using Octane+ P. putida as the donor, the transfer of most chromosomal markers was shown to be independent of OCT transfer, whereas the mobilization of the octanoate catabolism genes (octanoic and acetate) was dependent on OCT plasmid transfer. The presence of a fertility factor termed FPo has been postulated to explain these results. Strains carrying only this fertility factor have been obtained from strains carrying both OCT and FPo plasmids. Strains in which the OCT plasmid was transferred at high frequencies have also been isolated, and chromosome mobilization by OCT and FPo has been compared. A different gradient of transmission by OCT and FPo has been observed. It has also been shown that chromosome transfer by OCT was dependent on the bacterial recombination system, whereas the chromosome transfer by FPo was unaffected by the presence of a rec mutation in the donor strain.

Caprylates↗
PubMed1979

[Studies of the consecutive hydrolysis of dipeptidyl-4-(phenylazo)-phenylamides by an aminopeptidase from Brassica napus].

The relatively alanine-specific amino peptidase from Brassica napus hydrolyzes dipeptidyl-4-(phenylazo)-phenylamide according to a consecutive mechanism. Enzyme-kinetic studies of dipeptidyl-4-(phenylazo)-phenylamides carried out by means of spectrometrical procedures of measurement are only possible when the increase in the concentration of the fission product p-aminoazobenzene is recorded. For assessing the kinetic parameters of the intermediary steps of the hydrolysis of dipeptidyl-4-(phenylazo)-phenylamides a function is derived describing the dependence of the concentration of fission products of p-aminoazobenzene on reaction time. The satisfactory correspondence of the kinetic parameters calculated for the intermediary-originating substrate L-ala-4-(phenylazo)-phenylamide as substrate demonstrates the applicability of the procedure described in the present paper.

Aminopeptidases↗
PubMed1977

[Pharmacological effect of piprozoline on the exocrine pancreas of dogs (author's transl)].

Ethyl (Z)-(3-ethyl-4-oxo-5-piperidino-thiazolidin-2-ylidene)-acetate (piprozoline, Gö 919, Probilin) and its main metabolite Gö 3284 cause a long-acting stimulation of the ecbolic function of the exocrine pancreas in the dog after intraduodenal administration or after i.v. injection. This has been demonstrated by canulation of the ductus pancreaticus accessorius and by perfusion of the small bowel as well as by photometric evaluation of the perfusion streams and determinations of the activities of alpha-amylase, lipase and trypsin in the 2-min fractions thereafter. Piprozoline does not cause a rise of the bicarbonate secretion and volume. In its action to the exocrine pancreas it resembles very much cholecystokinin-pancreozymin. The value of piprozoline is discussed with regard to its stimulating effect on the ontogenetic unit of the epigastric region.

Amylases↗
PubMed1976

Rh-prophylaxis with immunoglobulin anti-D administered during pregnancy and after delivery.

During 1968-1973 510 Rh-negative, non-Rh-immunized primi- and multigravidae giving birth to Rh-positive infants, regardless of the ABO constellation, received 250 mug immunoglobulin anti-D post partum. In serological follow-ups using the indirect Coombs' test and the papain method more than six months after childbirth, Rh-antibodies were detected in two cases with papain but not at all with the indirect Coombs' test. Seventy women gave birth to Rh-positive babies in subsequent pregnancies. Twenty-six of these non-Rh-immunized women were given an intramuscular injection of 250 mug anti-D five to ten weeks before delivery and were included in a series comprising a total of 131 Rh-negative women who had received immunoglobulin anti-D in the estimated 32nd-34th week of pregnancy. Bilirubin and haemoglobin were determined in the neonates on cord blood and serum. The infants whose mothers had received immunoglobulin anti-D during pregnancy showed no signs of haematological abnormalities related to the administration of immunoglobulin anti-D. The determination of cord blood haemoglobin or bilirubin and serum bilirubin revealed no significant difference between Rh-positive infants and Rh-negative ones. Antibodies by the papain method were detected 41 of the women at the time of delivery (22 Rh-positive babies and 19 Rh-negative ones). There was no correlation between the time at which immunoglobulin anti-D was administered and the detection of antibodies at the time of delivery, regardless of the Rh group of the infant. The indirect Coombs' test was positive only in ten of the 48 Rh-negative infants examined. 250 mug immunoglobulin anti-D provides effective post partum prophylaxis, and the same dose administered to Rh-negative pregnant women prior to delivery did not cause any detectable haemolytic damage to the fetus.

Antibodies↗
PubMed1976

[Intrauterine gas gangrene in the 37th week of pregnancy].

A report is given on an infection of intrauterine gas gangrene of stage 2 according to Dieminger (Tumpania uteri) in the 37th week of pregnancy which turned out well. The clinical progress of gas gangrene is discussed. The abstention from a caesarian section by reason of indication of the child with suspicion of a severe intrauterine infection, the vaginal delivery which was forced subsequently, the prevailingly prophylactic administration of antibiotics, and the largely initiated infusion and transfusion therapy have in a high degree determined the positive end of the disease. The intensive observation of the woman in labor, who at first had only been clinically conspicuous, led to an early recognition of toxic symptoms, so that an aimed intensive therapy could be carried out.

Adult↗
PubMedDate not supplied

Using skin models to assess the effects of a protection cream on skin barrier function.

BACKGROUND: There is a basic necessity to understand the mechanisms of the protective effects of emulsions. This would promote the development of protective cosmetics and therefore improve the prevention and treatment of occupational skin diseases. However, for such studies, no reliable skin model is available. OBJECTIVE: An in vitro skin model test was developed to evaluate the protective mechanism of cosmetic ingredients. METHODS: The efficacy of three products was assessed by an in vivo test (Repetitive Occlusive Irritation Test) and then 3-dimensional skin model tests were carried out. RESULTS: In vivo test results demonstrate that the best protection against sodium dodecyl sulphate is offered by a multiple emulsion. In the case of a skin model test, sodium dodecyl sulphate led to cell damage, an increase in pro-inflammatory markers and some barrier lipids. The multiple emulsion increased the content of skin lipids, without inducing irritation or cell death. CONCLUSION: Skin models react similarly to sodium dodecyl sulphate compared to human skin and therefore they are suitable to study barrier repair after sodium dodecyl sulphate damage. It is likely that the superior protective effect of the multiple emulsion in vivo is based on the increased amount of skin barrier lipids.

Administration, Cutaneous↗
PubMedDate not supplied

Comparative anatomy of human and sheep laryngeal skeleton.

In a macroscopical study the dimensions of the adult laryngeal skeleton of man and sheep were compared. In both species the data for male and female were evaluated separately. In contrast to pronounced differences in size between male and female human larynges, the dimensions of both sexes in sheep proved to be very similar. In respect of 7 size values, the sheep larynx falls in the range between the male and female human larynx. This applies to most values for height, the antero-posterior diameter and the inferior breadth of the thyroid cartilage. In the sheep cricoid, the height of the lamina and the inner transverse diameter correspond closely to the human counterpart. The most conspicuous differences vis-à-vis the human larynx are the narrowing of the upper portion, the absent upper incisure of the thyroid and the relatively large dimensions of the arytenoid cartilages in sheep. Since in sheep the dimensions at the level of the glottis and of the subglottic space are within the range of the human larynx, the suitability of the sheep larynx as a model for experimental clinical laryngology is discussed.

Anatomy, Comparative↗
PubMedDate not supplied

Peritoneal mesothelial cells as a significant source of ascitic immunostimulatory protein 90K.

The tumor associated antigen 90K is known to possess cytokine-like modulatory properties on the cellular immune system, whereby accessory cells are the primary target of this molecule. In 67 ovarian cancer patients presenting with significant amounts of ascites, immunostimulatory protein 90K was detected in all ascitic fluid samples examined. Furthermore, 90K levels correlated to ascitic s-IL-2R content. To elucidate the source of protein 90K in ascitic fluid; its in vitro release was investigated in primary cultured normal human peritoneal mesothelial cells (HPMC). Peritoneal mesothelium was found to produce five-fold more 90K than ovarian cancer cells. Release of protein 90K was significantly increased by treatment with IFN-gamma in both mesothelial and ovarian cancer cells. In contrast neither IL-1 beta nor TNF-alpha treatment consistently influenced the secretion of 90K in either cell type.

Adult↗