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Biomedical subjects

X X Liu

Publications and source records attributed to X X Liu.

27 records · Page 2Linked to original sources
PubMed1991

A genetic study of retinoblastoma.

Eight patients with retinoblastoma (RB) were studied by high resolution chromosome R-banding technique, and the esterase D was quantitatively determined in red blood cells of the patients. Among these patients, 2 showed 13q14 deletion mosaicism, 1 showed a monosomy 13q14.1-q14.2, and the remaining 5 had normal karyotype. Our findings indicated that 1) the RB gene is located at 13q14.1. The result confirmed previous data; 2) 13q deletion is an important event in the development of RB; and 3) esterase D determination is an important diagnostic tool in the detection of 13q deletion, useful for prenatal diagnosis and genetic counselling.

Adolescent↗
PubMed1990

Characterization of castration-induced cell death in the rat prostate by immunohistochemical localization of cathepsin D.

Activities of cathepsin D (EC 3.4.23.5) were determined in three lobes of the prostate during their involution by both biochemical and immunohistochemical procedures. The activity of cathepsin D in noncastrated rats was 0.9 +/- 0.2 (mean +/- SE) 5.7 +/- 0.6, and 13.1 +/- 0.8 units/mg protein for the ventral, lateral, dorsal lobes, respectively. Following castration, there was a significant increase in enzymatic activity in all three lobes within 2-3 days. In the ventral lobe, the activity peaked in 5 days to 6.2 +/- 0.9 units/mg protein and declined slightly thereafter. In the lateral and dorsal lobes, the activity remained elevated (14-20 units/mg protein) throughout the postcastration period studied. Immunohistochemical staining of cathepsin D was localized in the cytoplasm of prostatic epithelial cells as fine discrete lysosomal granules. These granules were larger and more abundant in the dorsal and lateral lobes than in the ventral lobe and were not detected in prostatic stromal cells and seldom in the luminal fluid. Castration resulted in an immediate increase in the size and number of these granules in the epithelial cells, followed by a sudden further increase in cathepsin D staining in some but not all epithelial cells. Lysosomal granules gradually coalesced in these cells to form large vacuoles that fit the characteristic description of apoptotic bodies. Finally, after day 7 postcastration, collapse and disintegration of the entire glandular structure was noted. Using this procedure to localize cathepsin D as a tool, we were able to follow the morphological events of prostatic cell death during castration-induced involution in the rat at the light microscopic level.

Analysis of Variance↗
PubMedDate not supplied

Demonstration of the role of prostate-specific antigen in semen liquefaction by two-dimensional electrophoresis.

Two-dimensional protein profiles of human semen, prostatic fluid, and seminal vesicle fluid were compared to demonstrate changes in the protein composition of human semen before and after liquefaction. Semen specimens were obtained from a volunteer. Prostatic fluid specimens were collected by rectal massage from patients visiting a urology clinic. Samples of seminal vesicle fluid were collected by needle aspiration from isolated seminal vesicles, which were removed at surgery. All specimens were prepared and processed according to the ISO-DALT system for separation of proteins in two-dimensional gels. Following electrophoresis, protein spots in the gels were visualized by silver staining. Prostatic fluid and seminal vesicle fluid showed their characteristic protein profiles. The protein profile of human semen contained specific proteins of both prostatic fluid and seminal vesicle fluid. One major group of proteins in seminal vesicle fluid (Mw 28,000-68,000 daltons), designated as seminal vesicle-specific antigen, was observed in freshly ejaculated human semen, but disappeared from the two-dimensional profile when the ejaculate was allowed to stand at room temperature for 30 min. When prostatic fluid or prostate-specific antigen was mixed with seminal vesicle fluid and incubated at 37C for 30 min, the seminal vesicle-specific antigen also disappeared from the two-dimensional profiles. The findings indicate that seminal vesicle-specific antigen, a group of predominant proteins in seminal vesicle fluid, is the structural component of seminal coagulum, and that prostate-specific antigen is the enzyme which digests seminal vesicle-specific antigen and liquifies semen coagulum.

Adult↗