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Biomedical subjects

A Köhler

Publications and source records attributed to A Köhler.

At least 19 recordsLinked to original sources
PubMed1991

Lysosomal perturbations in fish liver as indicators for toxic effects of environmental pollution.

1. Lysomones play a key role in liver injury in fish caused by organic and inorganic xenobiotics. The lysosomal stability test was transferred to fish liver with the aim of testing responsive and practicable methods for biological-effects monitoring. 2. A two-step response of lysosomes in fish liver could be discerned, reflected by the activity (number and size of lysosomes) and the injury (membrane destabilisation) of the lysosomal detoxifying system. 3. Significant differences, with respect to lysosomal enlargement, membrane stability and pathological lipid accumulation, were found along a pollution gradient throughout the year. 4. The lysosomal tests clearly reflect the breakdown of the adaptive capacity of the fish liver to toxic injury. Therefore, a test battery measuring lysosomal perturbations should be recommended for the biological-effects monitoring.

Animals↗
PubMed1989

Investigations of chorionic villi after chorionic villus sampling (CVS). Correlation of morphological with clinical and laboratory data.

This report documents the first 262 cases of chorionic villus sampling (CVS) performed in parallel with cytogenetic and morphological investigations. Histomorphological examination of these CVS specimens gave suitable results in about 96% (251 cases). Of the latter, 201 samples (80.1%) exhibited villi and 176 (70.1%), maternal tissue. Viability and maturation of the chorionic villi were determined light microscopically even in cases with few villus trees. Smooth avascular villi with poorly defined margins observed under an inverted microscope, less than 10 mitoses after short-term incubation, and reduced growth of cell cultures were significantly correlated with sampling at the chorion laeve by means of histomorphologic criteria. Villi from cases exhibiting cytogenetically proved chromosomal abnormalities were characterized by molar degeneration or stromal fibrosis, or both, in 4 out of 9 cases, including 3 mosaics. In early abortions (within 3 weeks after CVS), an unexpectedly high rate of pathohistological changes within maternal tissue was evident. These results need further confirmation by investigation of a greater number of samples with immunohistochemical and morphometric methods.

Adult↗
PubMed1988

Feto-maternal transfusion after chorionic villus sampling. Evaluation by maternal serum alphafetoprotein measurement.

The alphafetoprotein (AFP) concentration in maternal serum was determined before and after chorionic villus sampling (CVS). A significant increase of 20% or more in the pre-CVS level was noted immediately after sampling in 59% of 837 pregnancies indicating some degree of feto-maternal haemorrhage. The increase in the AFP concentration in maternal serum was correlated with the weight of the tissue sample but not with the number of sampling attempts. A correlation of AFP increase and frequency of spontaneous abortions following CVS was suggested only in the group with an AFP increase of more than 100% or with a continuing rise in the first hour following CVS. CVS in early pregnancy obviously did not interfere with maternal serum AFP screening for neural tube defects in the second trimester. Although AFP measurement before and after CVS seems to have no immediate diagnostic application, in the research phase of CVS it may help to identify those procedures that are the least traumatic.

Abortion, Spontaneous↗
PubMed1986

[Hormone therapy of metastasizing breast cancer with tamoxifen].

Out of 79 patients with metastasized carcinoma of the breast in 33% (6 patients) a response to a Tamoxifen therapy could be observed. For complete remissions the remission periods were 12.3 months, for partial remissions 9.9 months and in the group of constant findings 4.9 months. Preferably metastases of the soft parts respond to the therapy. The side effects are very insignificant. The indications for the tamoxifen therapy are represented as well as the importance of the determination of hormone receptors.

Adult↗
PubMed1986

[Effectiveness and side effects of low-molecular weight heparin-dihydroergotamine in preventing thromboembolism in abdominal surgery].

Low-molecular heparin-dihydroergotamine had been applied once a day to 103 patients and heparin-dihydroergotamine twice a day to 97 patients as part of a double-blind, controlled, consecutive, and randomised clinical study, with 200 abdominal surgery patients being involved. High-risk patients above 40 years of age and potentially affected by thrombotically predisposing factors were almost equally represented in both groups. Evidence to postoperative thrombosis was phlebographically produced in either group. No fatal pulmonary embolism was found to be among ten deaths. No significant differences of clinical relevance were found to exist between both groups with regard to coagulative values, intra-operative and postoperative blood and drainage loss, and complications due to bleeding. No accumulated occurrence of major postoperative complications was recordable from either group. The vascular status of all patients was unchanged from beginning to end of the period of observation. The following conclusion was drawn as a result of the study: One single NMH/DHE injection daily is comparable with two HDHE applications per die for action and undesired side-effects.

Abdomen↗
PubMed1986

Acceleration of p-aminohippurate excretion in immature rats by dexamethasone treatment.

In 5-, 10- and 15-day-old rats repeated administration of dexamethasone caused a dose-dependent increase of p-aminohippurate (PAH) excretion. Remarkably, dexamethasone has no influence on PAH excretion in adult rats. The effect of treatment in young rats cannot be explained by an increase in the glomerular filtration rate. In 10-day-old rats GFR shows a tendency to increase. In renal cortical slices from 5-day-old rats PAH transport is increased following dexamethasone treatment, whereas in 10- and 15-day-old rats an increase of kidney mass seems to be responsible for acceleration of renal excretion of PAH after administration of dexamethasone. In 5-day-old rats only the protein content is statistically significantly increased after dexamethasone treatment.

Aging↗
PubMed1982

Studies on the mechanism by which ACTH stimulates renin activity and angiotensin II formation in man.

Ten IU of ACTH (1-24) per day was infused for 34 h (starting at 7 a.m.) into 8 normal men on a constant diet containing 135 mM Na+ per day. All subjects retained between 152 and 181 mM of sodium. Potassium balance was negative. Plasma renin activity (PRA) and plasmaangiotensin II (P-A-II) started to rise in most subjects after 6 to 8 h of infusion, reached a maximum after 24 h and then tended to decline. As shown previously, the rise in PRA is not due to a rise in plasma renin substrate concentration. Systolic, but not diastolic blood pressure increased significantly on the second day of ACTH-infusion. Plasma cortisol (P-F) was continuously stimulated by ACTH. Plasma aldosterone (P-aldo) increased rapidly 1 h after ACTH administration, then tended to fall, and increased again in most subjects, roughly in parallel with PRA. No significant changes in electrolyte balance, PRA, P-A II, P-F, and P-aldo occurred in 3 subjects receiving 'sham' infusions. Additional experiments in subjects treated with propranolol or indomethacin allowed the conclusion that the effect of ACTH on PRA and P-A II is not mediated by renal beta-adrenergic receptors, but perhaps (partially?) by prostaglandins. Since the infusion rate of ACTH was not much higher than the secretion rate of ACTH in the early morning hours, it is possible that ACTH is physiologically involved in the regulation of renin secretion.

Adrenocorticotropic Hormone↗
PubMed1981

ACTH stimulates plasma renin and angiotensin II in man.

1. Adrenocorticotropic hormone (ACTH; 10 i.u./day) was infused for 34 h into normal male subjects. Some subjects were additionally treated with propranolol or indomethacin. Others received sham infusions or hydrocortisone infusions instead of ACTH. 2. ACTH, but not sham or hydrocortisone infusions, led to a significant increase in plasma renin activity and angiotensin II concentration with a lag period of 7--10 h and a maximum response after 24 h. ACTH may be a physiological regulator of renin secretion, perhaps through a 'trophic' effect on the juxtaglomerular apparatus. 3. The effect of ACTH on renin is not mediated by a rise in plasma renin substrate, probably not by renal beta-adrenoreceptors, but perhaps by prostaglandins. 4. A dissociation between plasma cortisol and aldosterone during ACTH infusion suggests that ACTH, in this dosage, stimulates aldosterone on the second day through renin and angiotensin II, before its secretion is finally suppressed during more prolonged infusion.

Adrenocorticotropic Hormone↗