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Biomedical subjects

W Neumann

Publications and source records attributed to W Neumann.

At least 19 recordsLinked to original sources
PubMed1990

Forces on intraocular lens haptics induced by capsular fibrosis. An experimental study.

Electronic dynamometry measurements, performed upon intraocular lens (IOL) haptics of prototype one-piece three-loop silicone lenses, accurately defined the relationships between elastic force and haptic displacement. Lens implantations in the capsular bag of dogs (loop span equal to capsular bag diameter, loops underformed immediately after the operation) were evaluated macrophotographically 5-8 months postoperatively. The highly constant elastic property of silicon rubber permitted quantitative correlation of subsequent in vivo haptic displacement with the resultant force vectors responsible for tissue contraction. The lens optics were well centered in 17 (85%) and slightly offcenter in 3 (15%) of 20 implanted eyes. Of the 60 supporting loops, 28 could be visualized sufficiently well to permit reliable haptic measurement. Of these 28, 20 (71%) were clearly displaced, ranging from 0.45 mm away from to 1.4 mm towards the lens' optic center. These extremes represented resultant vector forces of 0.20 and 1.23 mN respectively. Quantitative vector analysis permits better understanding of IOL-capsular interactions.

Animals↗
PubMed1988

[Epibulbar melanoma in a cat].

In a nine-year-old female cat, the diagnostic procedure, therapy and differential diagnoses of a rare, primary, malignant, epibulbar melanoma are presented. Post-operatively no recidivation or metastases occurred within 18 months.

Animals↗
PubMed1987

[Refraction of the dog eye].

The refraction of 50 eyes of nonsedated dogs was measured by retinoscopy. The slightly hyperopic to middle-grade myopic refraction found in earlier studies was seen in individual cases; however the mean value of 0.5 D is close to emmetropy. The differences in the results of measurements made under non-influenced accommodation and cycloplegia were not significant. Keratometry with the Javal ophthalmometer showed a mean cornea radius of 8.77 mm. A average axial length of 20.9 mm was determined by sonography. In some instances the parameters examined varied considerably.

Accommodation, Ocular↗
PubMed1985

[Toxicologic studies with thymostimulin].

Thymostimulin (Tp-1 Serono) was tested toxicological in rats and monkeys during 6 weeks of repeated administration. Corresponding to the therapeutic use intended in man the substance was given to rats and monkeys intramuscularly in dosages of 10 or 100 mg/kg b.w. and due to technical reasons subcutaneously in a dosage of 1000 mg/kg b.w. No substance-related effects, either systemic or local, were observed in the monkeys. After treatment with the high dose level (1000 mg/kg b.w. s.c.) the rats exhibited inflammatory changes in the region of the injection sites.

Animals↗
PubMed1978

[Spongious cerebral dystrophy at an infant age (Canavan-Bogaert-Bertrand types) in three siblings of a non-Jewish family in upper Franconia (author's transl)].

A daughter and two sons of possibly consangineous parents died after motor and mental deterioration at 18, 16 and 15 months of age. Spongy degeneration of the CNS (Canavan-van-Bogaert-Bertrand type) was diagnosed on neuropathological examinationtion; the histological findings were almost identical in the patients. Own clinical experiences are compared with reports from the literature; data important in clinical and differential diagnosis are reviewed. Pathogenetical and etiological aspects are discussed; autosomal recessive inheritance has to be considered in genetic counselling.

Autopsy↗
PubMed1977

[Demonstration of the agent of bovine viral diarrhea-mucosal disease (BVD/MD) in comparison between organ fluoresence freezing method and the direct cultivation in tissue culture].

Organs of 100 calves whose clinical symptoms indicated a BVD/MD viral infection have been examined in the laboratory by different methods on BVD/MD virus in order to compare the effectivity of the single test-systems. By inoculation of organ material into tissue culture from foetal calf kidneys and additional staining with swine-fever conjugate in the CCSC-system 59 calves were detected as BVD/MD virus carriers. Taking this result for comparative purposes equal to 100% there could be stated an effectivity of 73% by inoculation of tissue cultures and judging cpe instead of staining with fluorescent antibody as above. Only 34% reactions could be demonstrated by means of heterotypic immunofluorescence in organ tissues. For diagnostic purposes a combination of the easy and quick method of heterotypic immunofluorescence in organ tissues and a cultural virus isolation from organ material with additional immunofluorescence is recommended.

Animals↗
PubMed1976

[Pharmacological investigations with the combination sulfamoxole/trimethoprim, a new broadspectrum chemotherapeutic agent (author's transl)].

Investigations were conducted with the combination of N1-(4,5-dimethyl-2-oxazolyl)-sulfanilamide (sulfamoxole) and 2,4-diamino-5-(3,4,5-trimethoxy-benzyl)-pyrimidine (trimethoprim) (CN 3123, Nevin, Supristol) in a dose ratio of 5:1, with respect to pharmacological activity and possible side effects. The effects obtained with the combination CN 3123 were compared with those of the single substances. In a dose range comparable to that as used in clinical treatment, there were no effects on cardiovascular or respiratory functions, on functions of autonomic and central nervous system, on contractility of smooth muscles and on data of clinical chemistry such as urine and electrolyte excretion, blood sugar, blood coagulation and liver function tests. Doses which are 5 to 10 times higher than the initial dose or 10 to 20 times higher than the maintenance dose used in man caused an increase of urine and sodium excretion without influencing potassium and chloride output. There were no signs of sedation as alteration of motility or EEG patterns, but in mice and rats there was an increase in both duration and depth of anaesthesia caused by barbiturates or ether. Only in a dose range 30 to 40 times higher than the initial dose for man there were some slight alterations with respect to cardiovascular system and liver function tests. In vitro, with high concentrations of CN 3123 there was a weak, unspecific spasmolytic effect on the isolated ureter and an increase in the refractory period of the guinea pig atrium. There were no hints that the side effects seen with separate administration of high or very high doses of sulfamoxole or trimethoprim were increased or poteniated by their simultaneous administration. Slight side effects in animals were only observed with doses exceeding the tenfold of the doses for therapeutic use in men. Therefore, the therapeutic range of CN 3123 seems to be more than adequate.

Animals↗
PubMed1976

[Toxicological investigations of the combination sulfamoxole/trimethoprim, a new broad-spectrum chemotherapeutic (author's transl)].

The chemotherapeutically effective 5:1 combination N1-(4,5-dimethyl-2-oxazolyl)-sulfanilamide (sulfamoxole) and 2,4-diamino-5-(3,4,5-trimethoxy-benzyl)-pyrimidine (trimethoprim) (CN 3123, Nevin, Supristol) was investigated to determine any evidence of toxicological potentiation or new toxic signs. It was found that CN 3123 had a very low acute toxicity when administered orally to mice, rats and dogs (oral LD50: mouse greater than 12 000 mg/kg; rat greater than 14 000 mg/kg; dog greater than 1000 mg/kg body weight). The combination was also tolerated by rats and dogs in repeated doses administered over a period of 4 or 26 weeks, that greatly exceeded the therapeutic dose. The only change observed occurred in the thyroid, which in all doses administered exhibited a dose-related increase in weight accompanied by histological changes indicating an activation of thyroid function and a hypersecretion of basophilic thyrotropic cells in the anterior lobe of the pituitary. Six weeks after discontinuation of treatment this condition showed a tendency to reversibility or had already returned to normal. In dogs there was a dose-related increase in iodine uptake by the thyroid and a decrease in serum thyroxine over a period of 6 months under the highest dosage of CN 3123 administered. Whereas the thyroid changes observed under the combination could be reproduced with sulfamoxole, no effect on thyroid weight was observed in rats and dogs in the subacute toxicity phase of a comparative investigation with trimethoprim. Moreover, trimethoprim did not increase the effect of sulfamoxole on the thyroid gland. The effect of sulfamoxole on the thyroid is discussed in detail with a review of the literature. It can be characterized as species-specific for sulfonamides in mice, rats, rabbits and dogs but not in monkeys or in man and appears to be caused by the inhibition of the organic binding of iodine in the thyroid, whereby the predisposing factors must vary considerably from species to species. The thyroid hypertrophy observed is due to the activation of the regulatory cycle via the anterior lobe of the pituitary. The following systemic changes occurred after 600 mg CN 3123/kg, a lethal-toxic dosage and the highest administered in the study: reduced body weight, decreased food consumption leading to cachexia, slightly increased SGPT and alkaline phosphatase, slight thrombocyte depression, enlargement and increased fatty degeneration of the liver, occurrence of necrotic areas in the liver, hemosiderin accumulation in Kupffer's cells, and an increase of reticular cells in the spleen. The acute toxicity of CN 3123 and all major functional and histological changes under repeated administration were due exclusively to sulfamoxole. The combination sulfamoxole/trimethoprim gives no indication of toxicological potentiation or new toxic signs.

Animals↗