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Biomedical subjects

S F Zhang

Publications and source records attributed to S F Zhang.

At least 55 records · Page 3Linked to original sources
PubMed1989

Biological activity in the repopulating rat spermatocyte after the withdrawal of gossypol treatment: I. The activity for DNA synthesis.

Mature male rats were treated with gossypol for various lengths of time after which the treatment was stopped to allow the arrested spermatogonia to revive. Fifteen days after withdrawal of the drug treatment, the arrested spermatogonia entered into the meiotic division and then reached the pachytene stage. The meiotic cells derived from the arrested spermatogonia were the first generation of the differentiated germ cells after long-term gossypol treatment. Centrifugal elutriation technique was used to isolate the repopulating pachytene spermatocytes (RPS) or the control pachytene spermatocytes (CPS) from the rat testis with or without receiving gossypol pretreatment. In vitro culture condition for RPS and CPS was established for the synthesis of DNA by the measurement of 3H-thymidine incorporation. The activity for DNA synthesis in RPS was studied and compared to that of the CPS. It was concluded that after gossypol treatment for various times, the incorporation of 3H-thymidine into the cellular thymidine pool of RPS was not affected. However, the activity for DNA synthesis in RPS was significantly lower than that in the CPS. The synthetic activity for DNA was reduced by 14%, 26%, 42%, 40%, and 40% in the RPS for the gossypol pretreatment of 3, 4, 6, 7, and 8 weeks, respectively.

Animals↗
PubMed1989

Biological activity in the repopulating rat spermatocyte after the withdrawal of gossypol treatment: II. The activity for the synthesis of cellular and nuclear basic proteins.

The synthesis of cellular and nuclear basic proteins in the first generation of the repopulated pachytene spermatocyte (RPS) and the control pachytene spermatocyte (CPS) was studied by the incorporation of 3H-arginine into proteins. After pretreatment with gossypol for various lengths of time, the synthetic activity for cellular protein in the RPS was slightly inhibited. In comparison to CPS, on the other hand, the inhibition ranged from 12% to 26% (for gossypol pretreatment from 3 to 12 weeks, respectively). However, the synthetic activity for nuclear basic protein in the RPS was drastically reduced in comparison to that of the CPS. The reduction ranged from 46% to 61% in RPS after receiving gossypol pretreatment for 3 to 12 weeks, respectively. Gel electrophoretic separation of the basic protein extracted from the pachytene cell indicated that the major basic proteins are nucleosomal linker and core proteins, i.e., histone H1, H2A,B, H3, and H4, and with a lesser amount of sperm-specific BP and X1 proteins. After gossypol treatment in the RPS, the synthesis of sperm-specific proteins (BP and X1) and core histones (H2A and H4) became drastically reduced. Finally, the effect of gossypol on the ratio of nuclear basic protein to DNA in RPS and the direct correlation of this ratio to nucleosomal spacing and chromatin structure are discussed.

Animals↗
PubMed1989

[Diagnosis and treatment of hiatal hernia and gastroesophageal reflux].

From 1962 to 1988, 17 patients with esophageal hiatal hernia with or without gastroesophageal reflux were treated. Among these, 14 patients received various types of gastroesophageal junction reconstructive procedures. Experience demonstrated that the clinical studies including gastroesophagography, endoscopy and intraluminal pressure patterns of esophagus are important diagnostic measures. It also seems, to us that intraluminal esophageal pressure monitoring during surgical operation is particularly useful in determining the adequacy of gastroesophageal reconstruction and may provide a dynamic evaluation of function of the gastroesophageal junction area. Some aspects of diagnosis and surgical treatment are discussed in detail.

Adolescent↗
PubMed1989

[Scleral buckling operation for primary retinal detachment and secondary acute angle-closure glaucoma].

Of 233 eyes (215 patients) operated on for primary retinal detachment with scleral buckling, 38 eyes (16.3%) developed angle-closure glaucoma. The authors found no correlation between onset of the post-operative IOP elevation and the age of the patient, the preoperative IOP, the width of the chamber angle, refraction, the duration of operation, and the number of operations. The clinical characteristics of this type of glaucoma, its pathogenetic mechanism, and management are discussed.

Acute Disease↗
PubMed1989

[Steroid diabetes: an analysis of 28 cases].

During a survey period of 28 years a total of 449 patients suffering respectively from pemphigus, systemic lupus erythematous and chronic nephritis was admitted to the hospital. Of the 286 patients who received glucocorticoid treatment 28 were found to have steroid diabetes (9.8%). The incidences of steroid diabetes in these diseases were as follows: pemphigus 20% (7/35), systemic lupus erythematous 12.5% (14/112), chronic nephritis 5% (7/139). Two thirds of the diabetic subjects appeared asymptomatic, while the remainder showed polydipsia and polyuria. Renal glucosuria was seen in 3 cases and hyperosmolar hyperglycemia in 4. Blood glucose level in 10 out of the 21 remaining cases was 8.9 +/- 1.5 mmol/L and in the other 11 cases 14.8 +/- 2.4 mmol/L. Generally, the treatment of steroid diabetes is not intricate. Satisfactory improvement was seen in about 80% of the patients if a strict line of therapy against primary diabetes was oriented. In this series 18 patients did well under the treatment either with reduction of steroid or with use of oral hypoglycemic agents or insulin or both. Their blood glucose levels returned to normal and urine sugar disappeared rapidly. Four of the 5 deaths were caused by their primary diseases. One died of pemphigus complicated with infection and shock exhibiting an ante mortem blood glucose level as high as 31.7 mmol/L, obviously hyperosmolar status being the predisposing factor. Due to the fact that most of the steroid diabetic patients were clinically asymptomatic, delayed or misbranded diagnosis was not infrequently seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Diet and cancer of the stomach: a case-control study in China.

A case-control study focusing on the role of single food items was undertaken in the Heilongjiang area, 241 patients with histologically verified stomach cancer and an equal number of controls (with non-neoplastic diseases) matched by age, sex and area of residence being interviewed during a 2-year period. Questions asked covered economic status, occupation, histories of smoking and drinking, diet and dietary habits and disease history. Data concerning the average frequency and quantity of consumption of single food items were obtained by the same interviewer. An inverse association between the consumption of vegetables and stomach cancer was observed whereas high intake of potatoes and of salted and fermented soya paste appeared to be high-risk factors. Specifically, Chinese cabbage plays an important role in reducing the risk of developing stomach cancer.

Adult↗
PubMed1988

Synthesis and testing of quinone-based bis(2,2-dimethyl-1-aziridinyl)phosphinyl carbamates as radiation-potentiating antitumor agents.

Two new drug candidates, in which a quinonoid moiety is linked to the reactive bis(2,2-dimethyl-1-aziridinyl)phosphinyl function, have been prepared and tested in vivo for antitumor activity and in vitro as potentiators of the cytotoxic effect of X-irradiation. Without irradiation only moderate effectiveness against leukemia P-388 in mice was exhibited by one of the quinonoid compounds that had sufficient water solubility to be used in the in vivo screening. However, both compounds were shown to potentiate the effect of X-irradiation in vitro by a colony-forming cell culture assay under hypoxic conditions.

Animals↗
PubMed1987

Antithymocyte globulin stimulates human hematopoietic progenitor cells.

Antithymocyte globulin (ATG), a horse antihuman thymus antiserum highly effective in the majority of patients with aplastic anemia, was studied for its in vitro effects on hematopoietic progenitor cells. Marrow cells isolated by an immunoadherence technique with the HPCA-1 (human progenitor cell antigen) monoclonal antibody after removal of contaminating T cells and macrophages formed erythroid colonies in methyl cellulose media in the presence of ATG at concentrations of 25-50 micrograms/ml. ATG also stimulated continuous production of hemoglobin-containing erythroid colonies beyond 35 days of culture when it was added to the culture weekly. ATG also had an indirect effect on myeloid (granulocytic and macrophagic) colony growth in vitro. At a concentration of 10 micrograms/ml, ATG stimulated late but not early myeloid progenitor cells to form mature colonies. This effect required the participation of lymphocytes containing the Leu-11 antigen and macrophages or supernatant fluids made from these two types of cells that had been preincubated with ATG for 3 hr and then cultured for 5 additional days. The supernatant fluids produced in such a manner showed characteristics similar to granulocyte colony-stimulating factor and had an activity peak that eluted at a volume corresponding to a 20,000 Da molecular mass protein by high-resolution liquid chromatography.

Antibodies, Monoclonal↗