Dynamics and administrative behavior of a multi-disciplinary medical center

Fifteen-second exposure of rabbit kidneys to 2 MHz focused ultrasound with approximately 900 w/sq cm acoustic power consistently produced localized parenchymal destruction. Evolution of the lesions was followed histologically over a one-year period. The lesions were sharply delineated from outlying renal tissue and had a concentric multizonal structure. Resorption of the damaged tissue with scarring was completed in 6 to 12 months following intermediate phases characterized by cellular infiltration. The lesions are compared to other models of renal injury, particularly with respect to cellular infiltration. A combination of mechanical, thermal, and ischemic factors seem to be responsible for development of ultrasonic lesions. The sharply circumscribed nature and ultimate complete scarring of the lesions suggest the feasibility of ultrasound in achieving selective complete destruction of renal parenchyma.     

Endoscopic sclerotization of the oesophagus wall or transhepatic thrombosis of the coronary vein: Alternative or complementary therapy of bleeding oesophageal varices in portal hypertension (author's transl)

Endoscopic sclerotization of esophageal wall has been performed in 48 patients with bleeding of esophageal varices. The mortality rate in the acute bleeding was 29,2%. There was no mortality, if sclerotherapy was done in the non hemorrhagic interval. Of the 48 patients 25 are still alive, 8 more than 2 years without bleeding. In 12 cases we performed transhepatic obliteration of the V. coronaria ventriculi. Only in 3 of them no further hemorrhage occurred within 6 months. Fibrosclerotization seems to be superior to the transhepatic obliteration, because the primary mortality and complications are lower and long term results better.     

Influence of strophanthin and 2,4-dinitrophenol to the scopolamine-evoked acetylcholine release in rat cortex]

In rats narcotized by urethan we investigated the effect of 2,4-dinitrophenol and ouabain with regard to the cortical release of acetylcholine stimulated by scopolamine and to the acetylcholine content of telencephalon changed in that way. Dinitrophenol increased the liberating effect of scopolamine. In the presence of dinitrophenol and scopolamine ouabain reduced acetylcholine synthesis resulting in an strong decrease of acetylcholine content on persistent diminished increase of acetylcholine release.     

Usability for genetic evaluations of records from herds participating in progeny test programs of artificial insemination organizations

Thirteen AI organizations provided identification of herds that participated in their progeny test programs in 1989 and 1990; 15% of those herds participated in programs of more than one AI organization, but only 2.6% participated in programs of more than two AI organizations. Of the 19,589 participating herds, 82 and 76% were enrolled in DHI test plans that were considered to be usable for genetic evaluations during 1991 and 1992. For herds that had participated in AI progeny test programs, mean percentages of usable records were 77% in 1991 and 78% in 1992; the mean percentages of usable records for nonparticipating herds were 62% in 1991 and 60% in 1992. Participating herds had larger mean herd sizes, higher means and standard deviations of milk yields, younger cows, and a lower percentage of registered cows than did nonparticipating herds. Analysis of variance was used to explain the variation in the percentage of records that were usable for genetic evaluations. Herds that participated in AI progeny test programs or that had smaller herd sizes, higher mean milk yields, younger cows, or larger percentages of registered cows had higher percentages of records that were usable for genetic evaluations. Improved usability of records for genetic evaluations would increase the efficiency of AI progeny testing, and consideration of herd characteristics associated with higher percentages of usable records should aid AI organizations in evaluating prospective herds for progeny test programs.     

Attachment of Cryptosporidium parvum sporozoites to human intestinal epithelial cells

An enzyme-linked immunosorbent assay-based attachment model using the human intestinal cell line Caco-2A was developed to study attachment of Cryptosporidium parvum sporozoites in vitro and to assess potential inhibitors of sporozoite binding. In this system, attachment was related to sporozoite dose, incubation time, and host cell differentiation status. Polyclonal antibodies to C. parvum as well as glycoprotein inhibitors of a sporozoite lectin reduced attachment. This model will be a valuable tool in elucidating specific molecules and mechanisms involved in sporozoite-host cell attachment.     

On the mechanism of ascorbic acid induced methemoglobin reduction of human erythrocytes (author's transl)

Ascorbic acid and dehydroascorbic acid penetrate the human erythrocyte membrane. In vitro methemoglobin is reduced nonenzymatically by both substances in concentrations of 10(-2) M to 10(-3) M. Dehydroascorbic acid is reduced nonenzymatically to ascorbic acid by GSH, even with low GSH-content of erythrocytes. Under physiological conditions ascorbic acid induced methemoglobin reduction is far less important than reduction by the NADH dependent methemoglobin reductase system. In methemoglobinemic conditions caused by toxic effects or by congenital methemoglobin reductase deficiency treatment with ascorbic acid is possible. However, critically increased methemoglobin content of the blood higher than 30% makes therapy with methylene blue necessary.