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D B Lubahn

Publications and source records attributed to D B Lubahn.

115 records · Page 7Linked to original sources
PubMed1983

Silver staining of histones in Triton-acid-urea gels.

A reliable method for silver staining histones in Triton-acid-urea gels was developed. Optimum staining is achieved by treating the gels either with amido black or a colorless, water-soluble analog of amido black, 2,7-naphthalenedisulfonic acid, prior to staining with ammoniacal silver. Staining of purified calf thymus histones H2A, H2B, H3, and H4 by this method is 30 times more sensitive than staining with amido black alone, allowing the detection of each histone and its modified forms down to the nanogram level. The use of 2,7-naphthalenedisulfonic acid dramatically shortens the procedure permitting histone patterns to be visualized within 5 h.

Acetates↗
PubMed1980

Sex steroid receptor analysis in human melanoma.

Melanomas from 20 patients were evaluated for estrogen and progesterone receptors. No restriction as to patient's age, sex, race, or menstrual status was made. Fifteen of the tumors were melanin producing. Of the 20 tumors examined, seven contained more than 3 fm/mg protein of specifically inhibitable estrogen binding. None of the tumors reported here demonstrated either a 4S or 8S binding protein as shown by sucrose density gradient analysis. All tumors in which estradiol binding was observed were melanin producing, whereas none of the amelanotic melanomas (five tumors) bound this steroid. Purified tyrosinase appeared to mimic the estrogen binding detected in melanoma cytosols, as demonstrated with the dextran-coated charcoal technique. Although the binding of estradiol to tyrosinase was inhibited by DOPA, the binding of estradiol to estrogen receptor preparations was not. These studies represent an extensive of previous studies of sex steroid binding in melanomas and suggest that gradient analysis and DOPA inhibition studies should be included in the evaluation of the estrogen binding phenomenon in human melanoma.

Adult↗
PubMedDate not supplied

The androgen receptor gene is located on a highly conserved region of the X chromosomes of marsupial and monotreme as well as eutherian mammals.

The androgen receptor gene (AR), which is located on the long arm of the human X chromosome, was mapped by somatic cell analysis and in situ hybridization in marsupial and monotreme species. Both methods demonstrated that it was located on the X chromosome in each marsupial species, and also in the platypus. We conclude that this gene is part of a highly conserved region of the mammalian X, represented by the human Xq, which formed part of the X chromosome in a mammalian ancestor 150 million years ago. Since this gene is located proximally on the long arm of the monotreme X, which is G-band homologous to the Y and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on its isolation by X-Y differentiation or on X inactivation.

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PubMedDate not supplied

Morphologic changes in efferent ductules and epididymis in estrogen receptor-alpha knockout mice.

Estrogen has been shown to have an important role in fluid reabsorption in efferent ductules of the testis. Our previous study of the estrogen receptor-alpha knockout mouse (ERKO) showed that the efferent ductules and rete testis were primary targets of estrogen receptor function. In the present study, a more comprehensive evaluation of the ERKO male reproductive tract was performed to determine the severity of effects in efferent ductules as well as the epididymis. The following observations were found in ERKO males: 1) blind-ending efferent ductules were more prevalent in ERKO than in wild type (WT) tissues; 2) glycogen-containing cells were observed at the rete testis-efferent ductule junction; 3) the tubular diameters of the efferent ductules and initial segment epididymides were dilated; 4) efferent ductules were dilated between 130 to 300% over wild type ductules; 5) efferent ductule epithelial height was reduced nearly 50%; 6) microvilli of nonciliated cells of efferent ductules were 64% shorter in length; 7) cilia were reduced in number; 8) initial segment epithelium was displaced into regions adjacent to the rete testis and in short segments of the common region of efferent ductule; 9) apical, narrow, and clear cells of the epididymis also were abnormal in some regions; 10) in the corpus and cauda regions, sperm granulomas were noted in one third of the ERKO males. In conclusion, the entire reproductive tract is affected in ERKO males. The cells showing the greatest effects were estrogen receptor-positive cells. It appears that in the ERKO mouse there are developmental anomalies that must be considered separately from adult dysfunctional changes in the male reproductive tract.

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PubMedDate not supplied

Morphometric study of the gubernaculum in male estrogen receptor mutant mice.

To determine role of estrogen receptors in testicular descent, a morphometric study of the testis and structures derived from the gubernaculum was made in sexually mature male mice having an estrogen receptor disrupted gene mutation (ERKO). Macroscopic dissections and sagittal serial sections were made of the pelvis of four wild-type mice, four mice heterozygous for the ERKO mutation, and four homozygous ERKO males. By external morphological examination the testes appeared to be descended in all three genotypes. All mice had development of a cremaster sac, which is derived from the gubernaculum, but this was twice as large in wild-type mice than in both the heterozygote or homozygote ERKO groups. The cause for the smaller cremaster sac appeared to be excessive development of the cremaster muscle in ERKO mice. The thickened muscle was associated with postmortem retraction of the testes into the inguinal canal or abdomen. Spermatogenesis and testicular volume were deficient in homozygous ERKO mice at this age. This study demonstrates that estrogen has a previously unknown role in masculine sexual development of the gubernaculum and the structures derived from it, such as the cremaster muscle.

Animals↗
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.

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