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Biomedical subjects

S W Zhou

Publications and source records attributed to S W Zhou.

At least 19 recordsLinked to original sources
PubMed2001

Effect of tetrandrine on neutrophilic recruitment response to brain ischemia/reperfusion.

AIM: To investigate the effect of tetrandrine (Tet) on neutrophilic recruitment response to bain ischemia/reperfusion (I/R). METHODS: Middle cerebral artery (MCA) ischemia (2 h)/reperfusion model was built on rats (male). Brain water content, neutrophilic recruitment, the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and activation of NF-kappaB in cellular nucleus after brain I/R were measured with dry-wet weight, 51Cr-labeled neutrophil, reverse transcriptase polymerase chain reaction, and electrophoretic mobility shift assay, respectively. RESULTS: Brain water and neutrophilic recruitment were parallelly increased from 3 h to 24 h after reperfusion (P < 0.01). The expression of ICAM-1 mRNA was detected at 1 h after reperfusion (P < 0.01), increased to the highest peak at 12 h (P < 0.01), and at 24 h decreased to level at 3 h. The activation of NF-kappaB was detected at 0.5 h after reperfusion (P < 0.01), increased to the highest peak at 6 h (P < 0.01), and at 24 h decreased to level at 1 h. Tet 10 and 20 mg/kg decreased brain water content, neutrophilic recruitment, the expression of ICAM-1 mRNA, and the activation of NF-kappaB at 6 h, 12 h, and 24 h after reperfusion. CONCLUSION: Tet inhibited neutrophilic recruitment, expression of ICAM-1 mRNA, and activation of NF-kappaB after brain I/R.

Alkaloids↗
PubMed2001

[Determination of acyclovir in mouse plasma and tissues by reversed-phase high performance liquid chromatography].

The aim of this study was to establish an high performance liquid chromatographic method for determining acyclovir (ACV) concentration in mouse plasma and tissues. A solution of 0.25 mL 60 g/L perchloric acid and 0.25 mL acetonitrile was added into 0.2 mL plasma or 0.2 g tissues to precipitate proteins. Following centrifugation, the supernatant obtained was injected into a reversed-phase column. Operating conditions were Hypersil ODS column(250 mm x 4.6 mm i.d., 5 microns), methanol-water-acetic acid(1:99:0.5, volume ratio) solution as mobile phase at a flow rate of 1.5 mL/min, UV detection at 252 nm. The detection limit of ACV concentration in plasma was 20 micrograms/L and that in tissues was 50 ng/g. The standard curves for ACV were linear in plasma and homogenate of tissues (r > 0.99). The precision of the method was good and the recoveries of ACV were higher than 97.5%. So this method is rapid, accurate and convenient for determination of ACV concentrations in plasma and tissues.

Acyclovir↗
PubMed2000

Panax notoginseng saponins attenuated cisplatin-induced nephrotoxicity.

AIM: To study protective effects of Panax notoginseng saponins (PnS) against cisplatin-nephrotoxicity. METHODS: Cisplatin-induced nephrotoxicity in mice in vivo, and primary culture of rabbit proximal tubular cells (PTC) in vitro were established. Blood urea nitrogen, serum creatinine, cell viability, DNA interstrand cross-link, DNA-protein cross-link, and cytosolic free [Ca2+]i were assayed with diacetyl monoxime, alkaline picrate, trypan blue, ethidium bromide binding, 125I-postlabelling, and Fur 2-AM, respectively. RESULTS: With pretreatment for 2 d in mice, PnS 100 and 200 mg.kg-1.d-1 suppressed cisplatin-induced high blood urea nitrogen level to 83% and 31%, and serum creatinine level to 86% and 42%, respectively (P < 0.01). Preincubated with PTC for 24 h, PnS 10 and 100 mg.L-1 inhibited cisplatin-induced decrease of cell viability from 78% to 81% (P < 0.05) and 89% (P < 0.01), respectively. PnS 10 and 100 mg.L-1 suppressed formations of DNA interstrand cross-link to 47% and 40%, DNA-protein interstrand cross-link to 77% and 42%, and cytosolic free [Ca2+]i overload in PTC to 70% and 63%, respectively. (P < 0.01). CONCLUSION: PnS was a prophylactic for cisplatin-induced nephrotoxicity, and mechanisms were relevant to the effects that PnS reduced cisplatin-induced cytosolic free [Ca2+]i overload, and formations of DNA interstrand cross-link and DNA-protein cross-link.

Animals↗
PubMed1999

6,7-dimethoxycoumarin attenuated cisplatin-induced DNA interstrand crosslink and DNA-protein crosslink in primary cultured rabbit kidney proximal tubular cells.

AIM: To study the mechanism of cisplatin interaction with DNA, and the attenuating effects of 6,7-dimethoxycoumarin (DMOC) on crosslink. METHODS: Primary cultured rabbit kidney proximal tubular cells (PTC) were established. DNA interstrand crosslink was assayed with ethidium bromide binding and DNA-protein crosslink with 125I-postlabelling. PTC were incubated with cisplatin for 24 h. DMOC was preincubated with PTC for 24 h, and cisplatin (26 mumol.L-1) was added into culture and incubated for another 24 h. RESULTS: Cisplatin induced formation of DNA interstrand crosslink (13, 26, 52, and 78 mumol.L-1) and DNA-protein crosslink (26, 52, and 78 mumol.L-1) (P < 0.01). DNA interstrand crosslink in DMOC (0.4, 4, and 8 mg.L-1) and DNA-protein crosslink in DMOC (4, 8 mg.L-1) were less than those in cisplatin group (26 mumol.L-1), respectively (P < 0.01). CONCLUSION: The mechanisms of cisplatin interaction with DNA in PTC were DNA interstrand crosslink and DNA-protein crosslink, and DMOC attenuated these effects in vitro.

Animals↗
PubMed1997

Major origin of mutagenicity of chlorinated drinking water in China: humic acid or pollutants.

Since Loper and Glatz (J. Toxicol. Environ. Health, 4:919-938;1978) discovered the presence of the mutagenicity in drinking water after chlorination in 1978, humic acid (HA) has been considered as an important source. But our research results show that only 1/8 of observed direct frameshift mutagenicity in tap water originated from chlorination of HA isolated from raw water. Contamination from industrial waste and human settlement (night soil) are important potential sources of mutagenicity in chlorinated drinking water. The results show that mutagenicity from night soil after chlorination depended upon pH of sample. Production of mutagenicity at pH 6 is ten times of that at pH 8, and decomposition process is necessary condition for mutagenicity production. Season variation of mutagenicity of tap is also presented in the paper.

China↗
PubMed1996

[Determination of azathiopurine concentration in human serum by second derivative spectra method].

A sensitive and rapid method for the determination of azathiopurine concentration in human serum was established. By using ultraviolet second derivative spectra, the method eliminated background interference of biological sample and coexisting drugs. The serum sample was extracted with ethyl acetate, the extract was evaporated to dryness with a gentle N2 stream, and 0.25 ml of methanol was added to dissolve the residue. Quantitative calculation was made with analytical wavelength of 274 nm and 293 nm, and peak- to- valley method. The minimum detectable concentration of AZP in serum was 25 ng.ml-1 and average recovery was 99.3% +/- 5.9%.

Azathioprine↗
PubMed1995

Experience with repair of hypospadias using bladder mucosa in adolescents and adults.

From July 1984 to January 1994, 113 hypospadias operations were performed using a free bladder mucosa graft. There were 31 primary cases and 82 secondary cases in which prior operations had been done. The meatus was penile in 33 patients, penoscrotal in 72 and perineal in 8. The cosmetic and functional results were satisfactory. Postoperative complications included 8 fistulas that required closure and 6 cases of stenosis treated by dilation. Our results suggest that hypospadias repair with a bladder mucosa graft is feasible and reliable. The technique has been performed successfully in the most complex as well as simple cases in adults and adolescents.

Adolescent↗
PubMed1994

Effect of the extracts of pumpkin seeds on the urodynamics of rabbits: an experimental study.

Pumpkin seeds were prepared into oil n-butyle alcohol and ether extracts. The effects of the three extracts on the urodynamics of rabbits were observed. It was concluded that the oil preparation could remarkably reduce the bladder pressure, increase the bladder compliance, reduce the urethral pressure. Other two kinds of preparations had no effect in this experimental. The mechanisms of the effect of oil preparation on the urodynamics and the prospect of clinical use was discussed.

Animals↗
PubMed1993

Effects of thymosin on the secretion of the sexual hormone in rats with experimental varicocele.

Hormonal abnormality in experimental varicocele induced by partial ligation of left renal vein and the effect of thymosin (fraction 5) on the secretion of the sexual hormone were studied in rats. Serum testosterone level was lowered after varicocele formation, but could be reversed or increased by intraperitoneal administration of thymosin 5 mg/rat twice a week for 4 weeks with concomitant increase of testicular testosterone content. Changes in FSH and LH both in serum and testis, determined with immunoassay method as that of testosterone, were insignificant as compared with control or thymosin treated groups.

Animals↗
PubMed1992

[T-lineage acute lymphoblastic leukemia. Report of 23 cases].

23 cases of T-lineage acute lymphoblastic leukemia (TALL) were identified by multiple monoclonal antibodies. TALL was characterized by a younger age of the patients (average age 28 years), strong male preponderance (M:F, 4.8: 1), mediastinal mass (19%), higher leucocyte count (71.4%), hepatomegaly (76.2%) and splenomegaly (90.5%). Of 19 cases of TALL who were subclassified according to the criteria for subclassification of TALL proposed by Reinherz, 10 cases expressed a surface antigen pattern consistent with the early thymocyte stage of TALL development, 8 cases were of common thymocyte stage and 1 case was of mature thymocyte stage. The phenotypes of TALL cells appear to be considerably heterogeneous. 12 of 18 patients who received chemotherapy had achieved complete remission (67%).

Adolescent↗
PubMed1991

Immediate postpartum IUD insertions in a Chinese hospital--a two year follow-up.

A data set consisting of 199 immediate postpartum IUD insertions performed at the Xuan Wu Hospital, Beijing, China was analysed in terms of insertion route, category of inserting personnel and device type. IUD expulsion and continuation of use were the outcome events of interest in this study. Based on our findings, the following hypotheses were derived for future confirmative studies: lower expulsion rates and hence, higher continuation rates of immediate postpartum IUD insertions are associated with (1) insertions through the abdominal incision wound for women who had a cesarean delivery as compared to immediate (less than 10 min) vaginal insertions in women with vaginal delivery; (2) obstetrician insertions, as compared to midwife insertions, and (3) use of the Delta T, as compared to that of the Delta Loop. For the derivation of the latter two hypotheses, only the vaginal insertions were studied.

Adult↗
PubMed1991

[Effect of nitroquine on protein synthesis of Plasmodium yoelii in vitro].

The erythrocytic stages of Plasmodium yoelii (BY 265 strain) were incubated with nitroquine (0.2 pmol.L-1 - 20 mumol.L-1), cycloheximide (0.1-10 nmol.L-1) and aminopterin (0.2 pmol.L-1 - 20 mumol.L-1) during 8 h in vitro. The results showed that the incorporation of [3H]-isoleucine into the protein by Plasmodium yoelii was inhibited by nitroquine (0.2 pmol.L-1) and cycloheximide (0.1 nmol.L-1), the inhibitory effect of nitroquine (IC50 = 0.16 nmol.L-1) was 397 times higher than that of cycloheximide (IC50 = 63.5 nmol.L-1). However, the incorporation of [3H]isoleucine into protein was not affected during at least 8 h of exposure to aminopterin (20 mumol.L-1). The results suggest that the inhibition of protein synthesis by nitroquine is one of the mechanisms of the early antimalarial action.

Aminopterin↗
PubMed1990

The effect of phage T7 lysozyme on the production of biologically active porcine somatotropin in Escherichia coli from a gene transcribed by T7 RNA polymerase.

We have analyzed the inducible synthesis of recombinant porcine somatotropin (rPST) from the phage T7 gene 10 promotor on the vector pET3a [Rosenberg et al., Gene 56 (1987) 125-135]. Low-level synthesis of phage T7 lysozyme is crucial for high-level synthesis (40%) of rPST, which is greatly reduced if T7 lysozyme synthesis is absent or too high. The synthesis of rPST mRNA is optimized in those constructs coding for low levels of T7 lysozyme, with a reduction in mRNA levels in constructs coding for higher levels of T7 lysozyme or no lysozyme. The rPST can be readily purified following a single chromatographic step and is biologically active as determined by the tibia test following administration to hypophysectomized rats.

Animals↗
PubMed1989

Sequencing of porcine growth hormone cDNA.

Sequences for two pGH cDNAs are reported in this paper. The cDNAs were obtained by reverse transcription from porcine pituitary gland mRNA, cloned, and screened. The results are discussed and the two cDNA sequencings are compared with one by Seeburg et al. and another by Vize et al.

Amino Acid Sequence↗
PubMed1989

Ultrastructural investigation of changes of pulmonary surfactant system in experimental emphysema produced by intratracheal elastase instillation.

In this study the dynamic changes of the pulmonary surfactant system in guinea pigs were observed by scanning electron microscopy, transmission electron microscopy and special electron stain for surfactant. The results showed that in the early stage of instillation of elastase, the pulmonary surfactant decreased. After one week, it increased gradually. Type II epithelial cells proliferated and their secretion increased. By the 25th day, the pulmonary surfactant system tended to return to normal, indicating that the changes of the pulmonary surfactant system may have some effect during the developing process of emphysema.

Animals↗
PubMed1989

[Ultrastructural study of the surfactant system during emphysema induced by elastase in guinea pigs].

The dynamic changes of pulmonary surfactant system in guinea pigs with experimental emphysema were studied with scanning electron microscopy, transmission electron microscopy and special electron stain for surfactant. The results showed that the surfactant decreased significantly and the destruction of alveolar walls were observed after 72 hours of injection of elastase. After one week, surfactant increased gradually, the number of alveolar II cells increased and the secretion of these cells was flourishing. Until 25 days, the pulmonary surfactant system tended to normal. The destruction and dilation of respiratory units was getting worse during this period. This study suggests that the changes of surfactant system play some roles in the process of the development of emphysema.

Animals↗