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Biomedical subjects

J Bauer

Publications and source records attributed to J Bauer.

At least 523 records · Page 29Linked to original sources

Alpha 2-macroglobulin synthesis in an astrocyte subpopulation.

The proteinase inhibitor alpha 2-macroglobulin (alpha 2-M) is an acute phase protein in the adult rat. During inflammatory events, it is synthesized in the liver and secreted into the bloodstream to remove proteases that are released on injury. Recently, its occurrence in fetal rat brain has been reported. Its cellular origin and biological function in the developing brain, however, remained obscure. In this article, it is shown that astroglial cells cultured from newborn rat brain synthesize and secrete alpha 2-M. Its synthesis markedly increases with time in culture. Immunocytochemical studies reveal that only a subpopulation of astrocytes is alpha 2-M positive, alpha 2-M synthesis in the developing brain by neuroectoderm-derived cells asks for a broader definition of its function in the body. Since interactions of proteases and protease inhibitors appear to play a crucial role in cell migration and neurite outgrowth, alpha 2-M expression in astrocytes is discussed not only in relation to its potential role in the acute phase response to injury in the adult brain but also in regard to its possible involvement in brain development.

Animals↗

[Changes in the genital tract of female swine after feeding with practice-relevant amounts of zearalenone].

Zearalenone is one of the most frequent, naturally occurring mycotoxins in feedstuffs: 13.9% of 710 samples analyzed contained zearalenone in concentrations of 1.0 to 1,725 micrograms/kg. Trial feeding with female pigs demonstrated that a zearalenone concentration of 250 micrograms/kg feed produced distinct redness and swelling of the vulva, slight swelling of the mamma and numerous vesicular follicles and some cystic follicles on the ovaria. The symptoms on the external genital tract were not observed when the zearalenone concentration in the feedstuff, was 50 micrograms/kg but the section also established that vesicular follicles on the ovaria of these animals were more frequent than on the ovaria of the control animal.

Animal Feed↗

Predictors of MCAT scores for black Americans.

If minority students likely to score low on the Medical College Admissions Test (MCAT) can be identified in advance, they can be advised to take existing preparatory programs, or programs can be developed to meet their needs. Correlation coefficients for a number of available independent variables with MCAT scores were determined for a population of premedical students at Xavier University of Louisiana. American College Testing (ACT) and Scholastic Aptitude Test (SAT) scores were found to have similar ability to predict MCAT scores, with a correlation coefficient of 0.64 between ACT composite and MCAT total scores. Correlations of sophomore year grade point average (GPA) with MCAT scores were only slightly weaker. Use of subtest scores for the ACT and SAT, grades in science courses, and Nelson-Denny Reading Test scores did not improve prediction to any real extent, either when used alone or in multiple linear regression analysis. In contrast to some previous studies, predictions for black men were as good as those for black women. Use of only ACT composite and sophomore year GPA together gave correlations only slightly weaker than predictions using a full range of variables; data from ACT composite and sophomore year GPA can be used for calculating predictive equations on many available micro-computers. These procedures may not be applicable to minority students at majority institutions.

Black or African American↗

[Reversible functional disorders of the intestinal tract caused by abdominal radiotherapy].

In 20 patients with malignancies receiving abdominal radiotherapy, tests for disturbed intestinal functions were performed at the beginning and at the end of the therapy and after 6 to 12 month following radiation. Four noninvasive tests were performed: 75Se-homotaurocholate (75SeHCAT) test for estimation of bile acid malabsorption; Schillings test for quantification of vitamin B12 absorption; H2-breath analysis before and after a test meal containing lactose as a parameter of lactose malabsorption; and 51Cr-EDTA test for estimation of intestinal permeability. Both bile acid and vitamin B12 absorption decreased significantly towards the end of abdominal radiotherapy in more than 50% of patients. Only one patient developed lactose malabsorption. After 6 to 12 month, these abnormalities had completely disappeared. In contrast, small intestinal permeability did not increase during radiotherapy but was significantly elevated 6 to 12 month following treatment as the only indication of chronic injury of small intestinal mucosa. During radiotherapy, a significant correlation existed between the severity of diarrhea and the degree of bile acid malabsorption.

Diarrhea↗

Feather and beak dystrophy and necrosis in cockatoos: clinicopathologic evaluations.

Several species of imported and captive-bred southeast Asian cockatoos with feather and beak disease (FBD) were evaluated. In recently emerging stained feathers from affected birds, intracytoplasmic magenta to basophilic inclusions of various sizes were found in macrophages and basophil-like cells within the pulp and feather epidermis. Occasionally, amphophilic intranuclear inclusions were seen within degenerated feather epidermal cells. On the basis of electron microscopic findings, intracytoplasmic inclusions were not membrane bound and consisted of crystalline arrays of viral particles (17 to 22 nm in diameter). On the basis of size and conformation, viral particles most closely resembled those of parvovirus or picornavirus. Consistent hematologic or serum enzyme differences were not found among affected or healthy cockatoos. Compared with findings in healthy cockatoos, cockatoos with FBD had significantly lower serum protein concentrations, and results of serum protein electrophoresis indicated that birds with FBD had significantly lower concentrations of prealbumin and gamma-globulin fractions. Mean pre- and post-ACTH plasma corticosterone concentrations of cockatoos with FBD were not significantly different from those of healthy cockatoos. In 8 of 9 affected cockatoos evaluated, serum T4 concentrations before and after thyrotropin stimulation were considered normal.

Animals↗

Identification of glucuronide metabolites of T-2 toxin and diacetoxyscirpenol in the bile of isolated perfused rat liver.

Isolated rat livers were perfused with either 2 mg T-2 toxin or diacetoxyscirpenol (DAS) in a recirculating perfusion system. To identify glucuronide conjugates, equal amounts of bile samples were incubated with and without (control) a beta-glucuronidase preparation and analyzed by capillary gas liquid chromatography-chemical ionization mass spectrometry. Enzyme treatment of bile obtained from liver perfused with T-2 toxin resulted in the detection of a total of 954 micrograms HT-2 toxin (control 6 micrograms), demonstrating that excretion into the bile was mainly as glucuronide conjugates. Minor metabolites of T-2 toxin in bile were identified as 3'-hydroxy HT-2 toxin (TC-3), 3'-hydroxy-7-hydroxy HT-2 toxin (TC-6), and the glucuronide form of T-2 triol (trace amount). The glucuronide conjugates of monoacetoxyscirpenol (340 micrograms) and scirpenetriol (10 micrograms) were found in bile obtained from liver perfused with DAS, while nonconjugated metabolites were not detected. It is assumed that considerable amounts of T-2 toxin and DAS were metabolized biphasically. In phase I both trichothecenes were deacetylated, in phase II the metabolites were conjugated giving rise to the glucuronic acid adducts.

Animals↗