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Biomedical subjects

J Bahr

Publications and source records attributed to J Bahr.

52 records · Page 3Linked to original sources
PubMed1979

Long term perifusion of rabbit ovarian follicles.

Preovulatory follicles were dissected from ovaries of estrous rabbits. Four follicles were placed in each chamber of a perifusion system. Medium 199, containing 10% rabbit serum and antibiotics, eluted through the chambers at a rate of 1 ml/10 min. Every 6 h for 36 h, 1 microgram of LH and 50 ng of FSH were injected into each chamber. P4, T and E2 were measured in the medium. P4 exhibited a peak after each of the injections at 6, 12, 18, 24 and 30 h. E2 and T gave major peaks after the injection at 0 time, with minor peaks after the injection at 6 h; thereafter T and E2 secretion gradually decreased to levels below those of baseline.

Animals↗
PubMed1979

[On the selectivity of the migration process in Latin America, illustrated by the example of the southern Chilean lake region].

"Migration is studied at Puerto Montt and Osorno [Chile] where the immigrants' origins are examined. The life cycle and the education of the migrants, and their economic activity and trades are examined. In all variables the immigrants differed from the locals: but the migrants vary much between themselves. They can be of different ages, and come from different areas."

Age Factors↗
PubMed1976

Plasma steroid concentrations in conscious and anesthetized rabbits.

The ovarian steroids, estrogen, androgen, and progestin, were measured in the peripheral plasma of adult female rabbits that were either conscious or anesthetized with sodium pentobarbital (nembutal) or halothane. Concentrations of estrogen, androgens, and progestin were determined before and at 10 and 45 min after systemic injection of either buffer or LH. In the controls androgen levels were significantly different between animals anesthetized with nembutal and halothane. However, the greatest treatment effect was noted in plasma progestin concentrations which were significantly elevated in halothane-anesthetized animals in comparison to the conscious and nembutal-anesthetized animals. Following LH, the androgen and progestin levels were significantly elevated over basal levels. Most likely the treatment effect observed in the controls was still present but was overridden by the increased release of steroids following gonadotrophin stimulation. This study suggests that halothane, in contrast to nembutal, does significantly elevate peripheral progestin and androgen levels.

Androgens↗
PubMedDate not supplied

[Polarization reversal in the development of Brazilian metropolises? An analysis based on demographic indicators, using the example of Sao Paulo].

"Using the example of Sao Paulo, this paper addresses itself to the question of how far the decrease in growth rates one observes in large Brazilian metropolises can be interpreted as a process of polarization reversal. The analysis is carried out on the basis of demographic data from small area units, which include the results from the most recent 1991 census. Although it had already been possible in the 1970s to discern first indications of such a process setting in, in the decade 1981-91 indicators of population growth and migration balances agree in pointing to a polarization reversal." (SUMMARY IN ENG)

Americas↗
PubMedDate not supplied

Estrogen receptor (alpha and beta) expression in the excurrent ducts of the adult male rat reproductive tract.

The understanding of estrogen's function in the male reproductive tract is limited, and estrogen receptor (ER) localization in the reproductive tract of the adult male rat has not been described. In the present study, ERalpha was localized by immunohistochemistry using ER21 antibody, which recognizes only ERalpha. Strongest immunoreactivity was seen in epithelia of ductuli efferentes and the initial segment of the epididymis. Nuclei of both ciliated and nonciliated cells were positive. The epithelium of the rete testis, and caput, corpus, and cauda epididymides stained less intensely for ERalpha. The vas deferens epithelium was ERalpha-negative. Stromal tissue in the excurrent ducts was also ERalpha-positive. Using 3H-estradiol autoradiography, specific binding of estradiol was seen in nuclei of ductuli efferentes. Estrogen receptor alpha mRNA expression was greatly enhanced in ductuli efferentes compared to other regions of the male tract and was 3.5x greater than in the uterus. For comparison, the presence of ERalpha was determined using reverse transcription-polymerase chain reaction (RT-PCR) amplification. Estrogen receptor beta mRNA was expressed throughout the male tract and in the prostate. These results indicate that all organs in the male excurrent ductal system of the rat express ERalpha and are potential targets of estrogen. However, the ductuli efferentes are the site of the most intense ERalpha expression. The role of ERbeta remains to be determined, but its expression appears ubiguitous in the male tract.

Animals↗