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Biomedical subjects

J Wu

Publications and source records attributed to J Wu.

At least 829 records · Page 46Linked to original sources
PubMed1998

[Development of human fetal preantral follicles in vitro].

OBJECTIVE: To study oocyte maturation of human fetal preantral follicles in vitro, the effects of different factors on oocyte maturation. METHODS: Preantral follicles were obtained from fetal ovaries from termination of 20-28 weeks gestation. Factors involved in the development, maturation of fetal preantral follicles were studied in tissue and cell culture by means of Northern blot, and RT-PCR (nested). RESULTS: (1) Preantral follicles obtained from fetal ovary increased in size to more than 120 microns in diameter without antrum formation and with increasing time the preantral oocytes became mature with extrusion of 1st polar body, insulin-like growth factor 1 (IGF-1) had a more marked effect on oocyte maturation, as compared with epidermal growth factor (EGF). (2) Expression of alpha fetoprotein mRNA occurred in fetal follicles on day 5, 15, 25, 35 of culture, and became negative on day 45 of culture. (3) Medium consisted of 1. human menopasual gonadotropin (hMG), 2. follicular fluid, 3. IGF-1, 4. EGF increased the expression of bcl-2 mRNA by 17.6%, 22.4%, 47.1% and 37.5% respectively in fetal follicular cells, and down-regulated the expression of p53 mRNA by 19.8%, 22.1%, 42.6% and 31.6% respectively. CONCLUSIONS: (1) The development and maturation of fetal preantral follicles in vitro differed from those in vivo. (2) Expression of bcl-2 mRNA increased and expression of wild-type p53 mRNA decreased during follicular development and maturation.

Cells, Cultured↗
PubMed1998

[WAF1/CIP1/p21 gene in wild type p53 and mutant p53 human breast cancer cell lines in relation to its cytobiological features].

OBJECTIVE: To study the WAF1/CIP1 gene DNA status, mRNA and protein expressions in human breast cancer cell line and its significance. METHODS: Using cell culture, molecular biological techniques such as Southern blot, Northern blot and immunocytochemical methods, the WAF1/CIP1 gene DNA status, mRNA and protein expression levels in MCF-7 expressing wild type p53(wtp53) and MDA-MB-231 expressing mutant p53 (mtp53) human breast cancer cell lines were detected respectively. The p53 and mdm-2 protein expression levels and cytobiological features of the 2 cell lines were compared and correlated to their WAF1/CIP1 gene expression levels. RESULTS: (1) There was no difference in WAF1/CIP1 gene DNA status in the two breast cancer cell lines. Neither of them showed gene amplificatian or deletion. However, the WAF1/CIP1 mRNA and p21WAF1/CIP1 protein expression levels of MCF-7 cells were higer than those of MDA-MB-231 cells (P < 0.05). (2) The character and cellular distribution of p53 protein in the two cell lines were clearly different. The expression level of mdm-2 proteion was significantly higher in MCE-7 than in MDA-MB-231 cells (P < 0.05). (3) Compered to the other breast cancer cell line, MCF-7 cells were better differentiated, grew more slowly and adhered more closely with each other. CONCLUSION: The WAF1/CIP1 gene expression at mRNA and protein levels is associated with p53 phenotype and some cytobiological features of human breast cancer.

Breast Neoplasms↗
PubMed1998

Effects of nerve growth factor on intracellular free Ca2+ in oxygen/glucose-deprived cultures from cerebral cortex of fetal rats.

OBJECTIVE: To explore the involvement of calcium in the mechanism of hypoxic/hypoglycemic insults and nerve growth factor (NGF) protection. METHODS: Neuron viability and lactate dehydrogenase (LDH) efflux in the bathing medium in cerebral cortex cultures from fetal rats were measured. Calcium fluorescent indicator Fura-2/AM was used to measure the intracellular free calcium ([Ca2+]i). RESULTS: Massive neuronal death occurred 16-24 h following the onset of hypoxia/hypoglycemia. NGF (3-100 micrograms.L-1) dose-dependently attenuated 24 h hypoxia/hypoglycemia-induced efflux of LDH and elevated the number of surviving neurons. Hypoxia/hypoglycemia induced a reduction in [Ca2+]i in early stage and a large elevation of [Ca2+]i in later period. NGF 50 micrograms.L-1 increased [Ca2+]i to normal limits during the early stages of hypoxia/hypoglycemia and prevented the later elevation in [Ca2+]i. CONCLUSION: The [Ca2+]i elevation may be responsible for the cell damage in oxygen/glucose deprived cultures. NGF protects cerebral cortical neurons against hypoxic/hypoglycemic insults via stabilizing [Ca2+]i level or preventing the late rise in [Ca2+]i.

Animals↗
PubMed1998

[Solid adsorption and stability of essential oil from pericarp of Gaultheria yunnaensis (Franch.) Rehd].

Experiments have been made on the solid adsorption and stability of the essential oil extracted from Gaultheria yunnanensis. The results show that among the chemical constituents of the oil, methyl salicylate accounts for 99.66%. Grain adsorbents of aluminum hydroxide gel have been proved useful in obtaining higher release rates of the oil at required temperatures as well as keeping the oil stable at room temperature.

Adsorption↗
PubMed1998

[Chemical constituents of the root of Epimedium acumiantum Franch].

Four known flavonol glycosides, ikarisoside A(I), 2"-O-rhamnosyl-icariside II (II), 2"-O-rhamnosyl-ikarisoside A(III) and ikarisoside B(IV) were isolated from the ethyl acetate extract of the root of Epimedium acuminatum. Their structures were elucidated by spectroscopic and chemical methods. II, III and IV were isolated from this plant for the first time.

Drugs, Chinese Herbal↗
PubMed1998

[Application of mitomycin C in glaucoma filtration surgery].

OBJECTIVE: To investigate the efficacy and the complication of glaucoma filtration surgery with intraoperative mitomycin C. METHODS: Between April 1994 and February 1996, 33 eyes of 28 patients underwent filtration procedures with intraoperative mitomycin C. Then a follow up of mean 6.65 months (range, 1-12 months) was taken. RESULTS: The Class I success rate was 72.7% when the intraocular pressure (IOP) was less or equal to 2.79 kPa without glaucoma medicine. The Class II success rate was 24.2% when the IOP was controlled with topical glaucoma medicine. In the postoperative period, persistant hypotony developed in 4 eyes, and hypotony-related maculopathy developed in 2 of these eyes. No conjunctival wound leak and endophthalmitis was present. CONCLUSIONS: Intraoperative mitomycin C in glaucoma filtration surgery can increase the success rate, while it is associated with a higher incidence of complications such as hypotony.

Adolescent↗
PubMed1998

[The timing and mode of surgery in patients with severe acute pancreatitis].

OBJECTIVE: To investigate the timing and mode of surgical management in patients with severe acute pancreatitis (SAP). METHOD: The timing, mode of operation and mortality were reviewed retrospectively in 50 SAP cases undergoing laparotomy in our hospital from 1985 to 1994. RESULT: The overall mortality was 14% and 85.7% of the mortality falls on the age between 40 to 60 years, with no difference in etiology and sex. The operative mortality reduced gradually in patients with longer duration of illness (P > 0.05). The operative mortality of 31.8% in patients undergoing laparotomy within 12 h after hospitalization was significantly higher (P < 0.05) than in these operated on later. When the number of injured extra-pancreatic organs increased, the mortality also increased significantly (chi(2) = 5.99, P < 0.05). The related mortality with shock, pancreatic necrosis and multiorgan failure (MOF) was 31.8%, 31.6% and 28%, respectively (P < 0.05). The main procedures of surgical management were pancreatic debridement and/or drainage, and combined surgical measures. CONCLUSION: The laparotomy timing is an important factor influencing mortality as well as the severity of pancreatic necrosis, sepsis, and MOF. Delayed laparotomy and 24 h preoperative management is recommended. Surgery adopted should be simple, efficient in drainage and debridement.

Adolescent↗
PubMed1998

[Long-term results of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension].

OBJECTIVE: To investigate the long-term effects of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension. METHOD: We analysed retrospectively the follow-up results of 140 portal hypertensive patients undergoing the combined therapy in our hospital from April 1978 to April 1997. Changes of portal hemodynamics were studied by Doppler Flowmeter and DSA pre- and-postoperatively and direct FPP measurement intraoperatively. RESULT: The operative mortality was 3.6%. No rebleeding was noted in a short period and rebleeding rate was 8.3% in a long term follow-up. The rate of postoperative hepatic encephalopathy was 5.0%. The long-term survival rate of 5-, 10- and 15-years was 83.6%, 64.5% and 54.5%, respectively. After operation FPP and PVP decreased significantly (P < 0.01) and FPP maintained at the level of 3.2 +/- 0.4 kPa. CONCLUSION: The combined procedure is a rational and practical procedure for the treatment of patients with portal hypertension.

Adolescent↗
PubMed1998

[Effects of freeze on Ca2+ and cyclic 3', 5'-adenosine monophosphate level in cultured human retinal pigment epithelial cells].

OBJECTIVE: To investigate the mechanism of retinal pigment epithelial (RPE) cell migration and proliferation at molecular level by measuring the concentrations of intracellular cyclic 3', 5'-adenosine monophosphate (cAMP) and calcium ion (Ca(2+)) level of frozen cultured RPE cells. METHODS: The culture of human RPE cells was frozen for 0s, 15s, 30s, 45s, 60s respectively at -70 degrees C. The concentrations of cAMP and Ca(2+) in cultured human cells were measured by Fura-2/AM fluorescent technique and endogenous protein combination method. RESULTS: After freeze for 15 s, the contents of cAMP and Ca(2+) in RPE cells were not changed significantly compared with the control (no freeze). After freeze for 30s, 45s, 60s respectively, the level of intracellular cAMP was significantly decreased, while the concentration of cytoplasmic free Ca(2+) was markedly increased, showing that the concentration of cAMP and Ca(2+) being antagonistic to each other. With the re-vitalization of RPE cells for 60 minutes, the intracellular free Ca(2+) gradually reduced. CONCLUSIONS: The decreased concentration of cAMP and increased concentration of free Ca(2+) in RPE cells may be the effective mechanism of RPE cell migration and proliferation after cryotherapy, and it possibly plays an important role in the formation of proliferative vitreoretinopathy.

Adolescent↗
PubMed1998

[The role of oxygen free radical in experimental keratitis].

OBJECTIVE: To test a possible role of active oxygen species in corneal inflammation. METHODS: A keratitis model was induced by an intrastromal injection of lipopolysaccharide (LPS) in one eye of New Zealand albino rabbits. During the inflammation process, the activity of corneal superoxide dismutase (SOD), an enzymatic scavenger of the superoxide free radical, was measured by chemoluminescent test, the level of corneal malonaldehyde (MDA), the final product of lipid peroxidation, was determined by thiobarbituric acid test, and the clinical and histopathological changes in cornea were observed. All the results of inflammatory cornea were compared with that of saline injected cornea. RESULTS: It was found that: (1) Significant decrease in SOD activity (P < 0.001) and increase in MDA level (P = 0.001) were observed in inflammatory cornea when compared with the controls. In the period of corneal inflammation, the increase in MDA level occurred after the decrease in SOD activity. (2) The severity of corneal inflammation was negatively correlated with the corneal SOD activity (r = -0.954, P < 0.001) and positively with corneal MDA level (r = 0.734, P < 0.001). Also a statistically significant negative correlation existed between SOD activity and MDA level in the inflammatory cornea (r = -0.623, P < 0.01). CONCLUSION: These findings suggest that active oxygen species play a role in LPS-induced keratitis and cause corneal injury by lipid peroxidation reactions on the polyunsaturated fatty acid of biological membranes.

Animals↗
PubMed1998

[Expression of bFGF in primary human lens epithelial cells].

OBJECTIVE: To study the mechanism of after cataract formation and investigate the expression of basic fibroblast growth factor (bFGF) in primary human lens epithelial cells (PHLECs). METHODS: Human lens epithelial cells were cultured in vitro, and the expression of bFGF was detected with immunohistochemistry and in situ hybridization. RESULTS: PHLECs express bFGF in protein and mRNA levels. CONCLUSION: Based on bFGF promoting PHLEC growth and differentiation, the results suggest that bFGF from PHLECs take part in promoting such cell growth and differentiation.

Epithelial Cells↗
PubMed1998

[Experimental observation of foreign gene transfer with lipofectin to the primary human lens epithelial cells].

OBJECTIVE: To determine whether an exogenous gene carried by lipofectin can be introduced into the primary human lens epithelial cells. METHODS: Plasmid DNA with beta-galactosidase gene carried by lipofectin was applied to primary cultured human lens epithelial cells. Gene expression was detected by enzymatic color reaction using X-gal as a substrate in the 2 and 6 days of expression after 12, 24, 36 hours of transfection respectively. The gene transfer positive rate of the lens epithelial cells was counted. RESULTS: The foreign gene could be transferred into primary human lens epithelial cells by lipofectin. In the expression of 2 days, transfer positive rate was up to 48% after 24 hours of transfection. CONCLUSIONS: Efficient and stable transfer of the functional gene can be achieved by lipofectin into the lens epithelial cells. Lipofectin is an available and a promising vehicle for delivering aim gene and studying on the mechanism of physiology and pathology of lens epithelial cells.

Epithelial Cells↗
PubMed1998

[Effect of neurotropin on brain edema induced by permanent focal cerebral ischemia in rats and collateral ventricular injection of carrageenan in mice].

Neurotropin, an inhibitor of the kallikrein-kinin system, has been used as an analgesic and anti-allergic drug in the clinic. The aims of this study are to evaluate the effect of neurotropin on brain edema induced by permanent focal cerebral ischemia in rats and collateral ventricular injection of carrageenan in mice and its mechanism. Drugs were given i.v. 15 minutes after middle cerebral artery occlusion in rats and immediately after carrageenan injection in mice. Brain water content was determined by wet/dry weight ratio. Results showed that neurotropin could reduce the brain edema induced by permanent focal cerebral ischemia in rats and collateral ventricular injection of carrageenan in mice at doses of 3.0, 6.0, 30.0 and 30.0 NU.kg-1 body weight. It also suggests that neurotropin reduced ischemic brain edema via inhibiting the kallikrein-kinin system.

Animals↗
PubMed1998

[The protective effects of nerve growth factor on peripheral nerve injury].

The protective effects of nerve growth factor (NGF) on peripheral nerve injury and sensory neuron growth were studied in three models: peripheral sympathetic nerve injury induced by intraperitoneal injection of 6-hydrodopamine (6-OHDA), mechanically injured ulnar nerve and cultured dorsal root ganglion (DRG) of newborn rats in vitro. The results indicate that NGF dose-dependently increased norepinephrine content in mouse submandibular gland and cell numbers of C7 (seventh cervical vertebra), T1 (first thoracic vertebra) dorsal root ganglion in rabbits, and also dramatically promoted the growth of neuronal projections in cultured DRG. These results suggest that NGF has significant neuroprotective action in peripheral nerve injury and a strong neuronutrition on sensory neuron.

Animals↗
PubMed1998

[Effects of nerve growth factor on intracellular free Ca2+ in oxygen/glucose-deprived cultures from cerebral cortex of fetal rats].

Oxygen/glucose deprived cortical cell cultures were used to explore the involvement of calcium in the mechanism of hypoxic/hypoglycemic insults and protection of nerve growth factor (NGF). Neuron viability and lactate dehydrogenase(LDH) efflux in the bathing medium of cerebral cortex cultures of fetal rats were measured as indication of the NGF effect. Calcium fluorescence indicator Fura-2/AM was used to measure free intracellular calcium([Ca2+]i). When cultures were deprived of oxygen/glucose, massive neuronal death occurred 16-24 h following the onset of hypoxia/hypoglycemia. NGF(3-100 micrograms.L-1) dose-dependenly attenuated the 24 h hypoxia/hypoglycemia-induced efflux of LDH and elevated the number of surviving neurons. Hypoxia/hypoglycemia induced a reduction in [Ca2+]i in early stage and then a large elevation of [Ca2+]i in 12-24 h. NGF 50 micrograms.L-1 brought [Ca2+]i to normal limits during the early stage of hypoxia/hypoglycemia and prevented the later elevation in [Ca2+]i. The [Ca2+]i elevation may be involved in the cell damage in hypoxia/hypoglycemia deprived cultures. It is believed that NGF protect cerebral cortical neurons against hypoxic/hypoglycemic insults via 'stabilizing' [Ca2+]i level or preventing the late rise in [Ca2+]i.

Animals↗