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Biomedical subjects

A Müller

Publications and source records attributed to A Müller.

At least 523 records · Page 29Linked to original sources
PubMed1988

[Oxygen partial pressure after rectal oxygen insufflation-- experimental animal studies].

An oxygen diffusion through the mucosa of the colon into the vessels of the submucous coat was provable after rectal insufflation of an oxygen-gas mixture by animal experimental investigations in rabbits. Significantly higher pO2 values in the blood of the mesocolon veins, the portal vein, in the arterial and venous mixed blood of the liver parenchyma, and in the arterial vessels of the mesocolon are measurable after rectal application of oxygen during a time of 40 minutes. The oxygen therapy after rectal oxygen insufflation is established by animal experiments.

Administration, Rectal↗
PubMed1988

[Changes in the pharmacokinetics of gentamycin during nephrotoxic therapy].

Nephrotoxicity secondary to aminoglycoside antibiotic therapy is a well-known complication in clinical medicine. We have analysed the influence of a 10-day gentamicin treatment with 3.40 mg/d on pharmacokinetic parameters and renal excretion of electrolyses and beta-NAG in 10 patients (9 female, 1 males) with UTJ. Using compartment-independent methods the following kinetic parameters at the first and 10th day of treatment were estimated: total body clearance from 100 to 80 ml/min (-20%), mean residence time from 2.7 to 3.5 h (+28%) and AUC from 6.7 to 9.4 mg/l.h (+41%). Similar results could be obtained using a linear two-compartment model: k13 is changed from 0.74 to 0.54 h-1 (-27%). Vdss approximately 16 1, k12 and k21 are not significantly influenced. There was no significant difference between the first and 10th day for renal excretion electrolyses, urine volume and osmolality with the exception of beta-NAG, which increased from 7.2 to 11.7 U/l (p less than 0.05). From the results it can be concluded that even a ten day gentamicin treatment with normal doses and serum concentrations in the therapeutic range less than 5 mg/l induce nephrotoxic effects at the glomerular and tubular side of the nephron. For quantification of the nephrotoxic effects we propose a nonlinear two-compartment model with a new pharmacokinetic parameter for renal damage. This new model allows to predict and to compare the nephrotoxic effects for different aminoglycoside antibiotics and different modes of treatment.

Electrolytes↗
PubMed1987

Aluminium induced damage of the lysosomes in the liver, spleen and kidneys of rats.

The influence of repeated aluminium (Al) administration (0.05 or 0.5 mg 100 g-1 b.w.t. i.p. 5 times weekly for 12 weeks) on the lysosomal enzymes N-acetyl-beta-D-glucosaminidase (beta-NAG) and beta-glucuronidase (beta-Gluc) in serum, liver, spleen and kidneys of adult female rats with intact kidneys, (NR), or following partial nephrectomy (5/6 NX) was investigated. After A1 loading, at the high dose only, the beta-NAG in serum and the free beta-NAG in liver, spleen and kidneys increased. Latent beta-NAG levels decreased in all three organs the effect being dose related. Following A1 loading no elevation in total enzyme activity was observed, with one exception. Depending on A1 doses the spleen of the non-operated animals, the liver of both groups of animals and the serum showed a decrease in beta-Gluc activity. No effect on beta-Gluc activity was observed in the spleen of 5/6 NX animals or in the kidneys of either group of animals. The results confirm that high doses of Al induce toxic effects and damage the lysosomes in the liver, the spleen and the kidneys. The results indicate that the extent of lysosomal damage correlates with dose and duration of Al loading. Repeated administration of Al also interferes selectively with enzyme synthesis.

Acetylglucosamine↗
PubMed1987

Isolation and characterization of Nicotiana plumbaginifolia nitrate reductase-deficient mutants: genetic and biochemical analysis of the NIA complementation group.

Two hundred and eleven nitrate reductase-deficient mutants (NR-) were isolated from mutagenized Nicotiana plumbaginifolia protoplast cultures by chlorate selection and regenerated into plant. More than 40% of these clones were classified as cnx and presumed to be affected in the biosynthesis of the molybdenum cofactor, the remaining clones being classified as nia mutants. A genetic analysis of the regenerated plants confirmed this proportion of nia and cnx clones. All mutants regenerated were found to carry monogenic recessive mutations that impaired growth on nitrate as sole nitrogen source. Mutants propagated by grafting on N. tabacum systematically displayed a chlorotic leaf phenotype. This chlorosis was therefore related to the NR deficiency. The observation of leaves with NR- chlorotic sectors surrounded by NR+ wild-type tissues suggests that an NR deficiency is not corrected by diffusible factors. Periclinal chimeras between wild-type tobacco and the NR- graft were also observed. In this type of chimeric tissue chlorosis was no longer detectable when NR+ cells were in the secondmost (L2) layer, but was still detectable when NR- cells were in the secondmost layer. The genetic analysis of nia mutants revealed that they belong to a single complementation group. However three nia mutants were found to complement some of the other nia mutants. The apoenzyme of nitrate reductase was immunologically detected in several nia mutants but not in other members of this complementation group. Some of the nia mutants, although they were NR-, still displayed methylviologen-nitrate reductase activity at a high level. These data show that the nia complementation group corresponds to the structural gene of nitrate reductase. Some of the mutations affecting this structural gene result in the overproduction of an inactive nitrate reductase, suggesting a feedback regulation of the level of the apoenzyme in the wild type.

Chimera↗
PubMed1987

Immunohistochemical detection of cathepsin D in human neuroontogenesis.

An antiserum against rat liver cathepsin D, which was previously found to cross-react with human brain cathepsin(s) D, was used to immunolocalize the enzyme in developing CNS man. Cathepsin D protein was found in neurons as well as in glial cells. The aerliest occurrence of cathepsin D was observed in neuroblasts at the 12th gestational week. During pre-, peri-, and postnatal neuroontogenesis, there is a strong increase in the amount of immunoreactive material.

Brain↗
PubMed1987

Fluorescein dilaurate serum test: a rapid tubeless pancreatic function test.

The value of a modified fluorescein dilaurate (FDL) serum test for the detection of pancreatic exocrine insufficiency was investigated in 89 patients with and without pancreatic disease. This test modification with fluorescein serum determination following metoclopramide (10 mg) and secretin (1 U/kg) i.v. injection appeared efficacious in a pilot study in six healthy volunteers. Individual peak fluorescein serum concentration was achieved within 180 min after the test meal in 96% of all subjects studied. Peak fluorescein serum concentration within this time period allowed the best discrimination between normal and abnormal pancreatic function. Sensitivity in detection of chronic pancreatitis was 86% (38 of 44 patients) when the lower normal fluorescein serum concentration was considered 4.5 micrograms/ml (this value corresponds to mean - 2 SD). The specificity of this test in detecting chronic pancreatitis was 100% when healthy controls were considered, but fell to 78% when patients with different gastrointestinal disorders, including those with secondary pancreatic insufficiency, were included. The correlation between serum and urinary fluorescein determination was significant (r = 0.61; p less than 0.01). Duodenal bicarbonate output/h after secretin also showed a significant correlation with peak fluorescein serum concentration (r = 0.79; p less than 0.001).

Adolescent↗
PubMed1987

[Cryopreservation of bone marrow for the autologous transplantation in children].

In preparing the autologous transplantation of children a method for cryoconservation of bone-marrow was developed by means of investigating the donor's bone-marrow. This method is adapted to our conditions, can easily be practised and is cell-preserving. Quantity and quality of the stored bone-marrow cells were evaluated concerning their proliferation capability by means of CFU-c assays. The highest recovery in CFU-c (78%) and cells (98%) was observed if isolated mononuclear cells with cryoprotective addition of 5% DMSO, 20% of human albumin, and 20% of serum were slowly frozen at a controllable rate, stored in liquid oxygen and thawed very quickly. According to the elaborated method the remission marrow was taken from 15 children affected with malignant diseases for autologous reinfusion. The data gained here confirm the experimental experiences.

Adolescent↗
PubMed1987

[Elimination of T lymphocytes from the bone marrow in HLA-incompatible bone marrow transplantation].

The method presented is very well suited to eliminate T-lymphocytes from great amounts of bone-marrow. The stem cells required to reconstitute the bone-marrow are enriched in this way. It can be completely performed in a closed system. Any contamination with germs is excluded. It can be reproduced well and learnt quickly. It takes 10 hours for two trained co-workers to process 1,500 ml of bone-marrow. The vitality of cells is very good (100%). Its suitability for transplantation has still to be checked.

Bone Marrow Cells↗
PubMed1987

Alcohol, aldehydes and lipid peroxidation: current notions.

The relations between membrane damage, lipid peroxidation and the effects of alcohol have attracted longstanding interest. In vitro studies showed that parameters of lipid peroxidation were positive. However, in vivo studies did not always provide clearcut conclusions. Our interest and that of a number of other groups, therefore, has centered on the intact organ and intact animal, using noninvasive indicators of lipid peroxidation such as ethane or pentane release and low-level chemiluminescence. The studies were mainly carried out with the isolated perfused rat liver, and there is substantial evidence for aldehydes being crucial in promoting lipid peroxidation. The range of aldehydes was extended from acetaldehyde to longer-chain aldehydes; in particular, aldehydes which themselves can originate from polyunsaturated fatty acid breakdown, e.g. 4-hydroxynonenal and congeners, were studied and were found to be potent in supporting lipid peroxidation.

Aldehydes↗