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Biomedical subjects

Y Shi

Publications and source records attributed to Y Shi.

At least 145 records · Page 8Linked to original sources
PubMed2001

[Automatic analysis and research on the trend of ST-T segment based on KL transform].

In view of the limitation of monitoring the trend of ST segment with the traditional method(ST level), we introduce a new monitor method based on KL transform. This method has overcome many disadvantages of ST level, e.g. the susceptibility to interference, a large variation of performance and the reflection of isolated characteristic. This method can characterize the signals stably and adequately. We have made experiment and analyzed the property of this method by using the standard database. The results indicate that the KL transform is of great clinical significance in detecting and monitoring the abnormality of the ST-T segment waveform over a long period of time, and the effect of monitor is also laid on the selection of KL series.

Electrocardiography↗
PubMed2001

Increased nitric oxide in peritoneal fluid from women with idiopathic infertility and endometriosis.

OBJECTIVE: To verify whether nitric oxide in peritoneal fluid is associated with endometriosis and infertility. STUDY DESIGN: Twenty-five women with idiopathic infertility and 38 with endometriosis were recruited, and 18 cases of uterine myomata and 2 cases of ovarian cyst served as controls. Peritoneal fluid samples were aspirated from the pouch of Douglas during laparoscopy or laparotomy. Metabolites of nitric oxide (nitrite and nitrate) in peritoneal fluid were determined by a method using nitrate reductase and the Griess reaction. RESULTS: Peritoneal concentrations of nitrate/nitrite in both infertile women (42.02 +/- 12.98 mmol/L) and patients with endometriosis (41.75 +/- 16.42 mmol/L) were significantly higher than that in controls (33.96 +/- 13.07, P < .05 for both). No significant difference in peritoneal nitrate/nitrite level was found between infertile women and patients with endometriosis (P > .5). Peritoneal levels of nitrate/nitrite were comparable among patients with endometriosis at different stages (P > .5). Patients with endometriosis had more peritoneal fluid than controls and idiopathic infertile women, while controls and idiopathic infertile women had comparable amounts of peritoneal fluid. CONCLUSION: An increased peritoneal level of nitric oxide is a common alteration in endometriosis, endometriosis-associated infertility and idiopathic infertility and may be associated with the pathogenesis of these diseases.

Adult↗
PubMed2001

[The follow-up of 12 pregnant women with anticoagulation therapy after mechanical heart valve replacement].

OBJECTIVE: The article discusses the effect of warfarin on pregnant women and their fetus, and the methods of anticoagulation therapy during pregnancy. METHODS: The pregnancy, delivery, and anticoagulation therapy of 12 pregnant women with mechanical heart valve replacement were followed-up. RESULTS: All the patients received oral anticoagulant therapy during pregnancy. The mean dose of imported warfarin was (2.71 +/- 1.24) mg/d (4 cases); domestic warfarin, (3.14 +/- 0.28) mg/d (6 cases); domestic acenocumarol tablet (3.14 +/- 1.08) mg/d (2 cases). No thromboembolism and major hemorrhage occurred. A total of 8 person/times had minor bleeding. Ten patients had term delivery, 2 had premature birth, No abnormal fetus was observed. Only 1 newborn had low birth weight (2,100 g). CONCLUSION: The anticoagulation therapy with low dosage of warfarin (< 5 mg/d) is safe and convenient for the mothers during pregnancy following mechanical heart valve replacement and has low fetus abnormal rate.

Adult↗
PubMed2001

[Influence of fertilization depth on root system senescence of upland wheat after anthesis].

A soil column study showed that fertilization in a depth of 20-40 cm sustained the activities of superoxide dismatase (SOD) and catalase (CAT) in root system at a high level, meanwhile the root system vigor, the soluble protein content in root system decreased slowly, and the content of malondiadehyde (MDA) in wheat root system decreased, which delayed its senescence. It is considered that the depth (20-40 cm) of fertilization could be used as an index for delaying senescence.

Catalase↗
PubMed2001

[Clear lens extraction with phacoemulsification and posterior chamber intraocular lens implantation for treatment of high myopia].

OBJECTIVE: To probe into the effectiveness and safety of clear lens extraction with phacoemulsification and implantation of posterior chamber intraocular lens (PC-IOL) to correct high myopia. METHODS: Phacoemulsification and implantation of PC-IOL through scleral tunnel incision was performed on 36 eyes of 26 high myopic patients with clear crystalline lens. The average age of patients was 53.9 years (36-67 years) old. The preoperative corrected visual acuity was 0.2-1.0. The mean preoperative spherical equivalent and astigmatism was (-13.11 +/- 4.33) D and (0.72 +/- 0.91) D respectively. The mean axial length was (28.02 +/- 2.14) mm. The mean diopter of IOL was (+8.62 +/- 4.76) D. RESULTS: The uncorrected visual acuity improved in all cases postoperatively, with 25 eyes (69.4%) achieving > or = 0.5. After surgery, the corrected visual acuity improved in 27 eyes (75.0%), and was > or = 0.5 in 35 eyes (97.2%). The mean postoperative spherical equivalent and astigmatism was (-1.51 +/- 0.60) D and (0.64 +/- 0.80) D respectively. The average follow-up was 23.5 months (7-35 months). The postoperative complication was posterior capsular opacification (5.6%). No retinal hole or detachment and cystoid macular edema were observed in this series. CONCLUSIONS: Clear lens phacoemulsification and PC-IOL implantation to correct high myopia is a safe, effective procedure serving as a refractive surgery. It is worth to spread due to good outcome of visual acuity, low incidence of complications, high predictability and stability.

Adult↗
PubMed2001

[Establishment and experimental study on mouse model of Chlamydia pneumoniae pneumonitis].

OBJECTIVE: To evaluate mice as experimental animals for Chlamydia pneumoniae (C. Pneumoniae) infection and investigate the pathogenesis of C. pneumoniae pneumonitis. METHODS: The Icr mice were inoculated with C. pneumoniae, strain CWL-029, by the intranasal or intravenous routes. After a single inoculation, mice were killed on the 1st, 3rd, 7th, 15th, 21th, 28th and 60th day separately. The pathological changes of lung tissue were analyzed. RESULTS: The Icr mice were shown to be susceptible to C. pneumoniae. Inoculation of mice with C. pneumoniae induced a prolonged course of lung infection, as demonstrated by persistence of lung pathology (60 days). In the intranasal inoculation of mice, the lung pathology was characterized by patchy interstitial pneumonitis with predominately neutrophil leukocyte infiltration in the early(7 days) and lyphocytes infiltration in the later stages(14 days later) of infection. After i.v. inoculation, a similarly interstitial pneumonitis was seen, but it was milder and more patchy, especially in the early stage. C. pneumoniae DNA was detected by polymerase chain reaction(PCR) intermittently in the lung tissue. Inoculated mice developed serum IgG antibody responses. CONCLUSIONS: The Icr mice were shown to be susceptible to C. pneumoniae and the pulmonary infection was characterized by interstitial pneumonitis, especially in mice of intranasal inoculation.

Animals↗
PubMed2001

Modulation of BmKAS-1 and BmK1-3-2 to sodium channel in rat dorsal root ganglion neurons.

OBJECTIVE: To investigate what effects BmKAS-1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal-muscle ryanodine receptor) and its upstream mixture BmK1-3-2 have on Na+ channels in dorsal root ganglion (DRG) small diameter neurons. METHODS: The whole-cell patch-clamp technique was used to investigate the effects of BmKAS-1 and BmK1-3-2 on Na+ current in rat small diameter DRG neurons. RESULTS: About 50% peak Na+ current was suppressed by 10 micrograms/ml of BmK1-3-2. 1.62 micrograms/ml of BmKAS-1 also blocked 50% peak Na+ current, and there was an obvious dose-dependent relationship. CONCLUSION: Both BmK1-3-2 and BmKAS-1 have a blocking effect on Na+ channels, and this may one of the mechanisms for the analgetic effect of BmK1-3-2 and BmKAS-1.

Animals↗
PubMed2001

Epidemiological investigation of Histoplasma capsulatum infection in China.

OBJECTIVE: To provide reliable information concerning the presence or the absence of Histoplasma capsulatum (H. capsulatum) infection in China, and data concerning this respect. METHODS: Three hundred normal people and 435 hospitalized patients, who lived in Hunan and Jiangsu provinces, and the Xinjiang Autonomous Region, were tested with yeast-phase histoplasmin (ALK/Berkerley Biologicals Laboratories, USA) and human pure protein derivative of tuberculin (PPD) on the volar surface of the forearm. Any reaction to the antigens over 5.0 mm in diameter of induration at 48-72 hours was considered positive. RESULTS: A total of 138 subjects (18.8%) in 735 patients reacted to histoplasmin with 5.0-45.0 (9.1 +/- 4.3) mm indurations. Significant differences of positive skin reaction rates in normal subjects were found in Hunan, Jiangsu and Xinjiang (8.9% vs 15.1% vs 2.1%). The overall positive rate of patients was 25.5%. Patients with tuberculosis [31.7% (78/246)] had a significantly higher positive skin reaction rate in comparison with those suffering from pneumonia [17.7% (11/62)], lung cancer [20.9% (9/43)], chronic obstructive pulmonary disease [17.3% (9/52)] and other diseases [12.5% (4/32)] (P < 0.01). Of 562 cases, 292 cases (52.0%) reacted to PPD with indurations of 5-50 (13.7 +/- 4.9) mm in diameter, 63 cases (11.2%) reacted to both histoplasmin and PPD, while 38 cases (6.9%) reacted to histoplasmin but not to PPD. CONCLUSIONS: The data suggest that there is H. capsulatum herd infection in China. The infection rate in Southeast China is higher than that in the Northwest, and the infection rate of patients with pulmonary tuberculosis is higher than that of normal persons and other pneumonopathy patients.

Adult↗
PubMed2001

Diagnosis and surgical treatment of temporal lobe epilepsy.

OBJECTIVE: To discuss the diagnosis and surgical treatment of temporal lobe epilepsy. METHODS: From 1996 to 1998, 36 patients presenting with medically intractable temporal lobe epilepsy were identified by EEG and MR, including volumetric MR, for hippocampal formation. Among them, 16 patients underwent anterior temporal lobectomy, while 20 patients accepted selective amygdalohippocampectomy. The results of surgical operation and follow-up are analyzed. RESULTS: With respect to seizure outcome, all patients benefited from surgery. The surgical results were satisfactory in 24 cases, notable in 11 cases, and good in 1 case, and there were no complications. CONCLUSION: MR is beneficial for the localization of epileptic foci. Surgery is an effective method for the treatment of temporal lobe epilepsy; selective amygdalohippocampectomy is the first choice for medial temporal lobe epilepsy. The transzygmatic-temporal lobe base approach presented in this study improved the safety of the surgery.

Adolescent↗
PubMed2001

Influence of growth hormone-insulin-like growth factor I axis on normal pregnancy.

OBJECTIVE: To investigate the role of growth hormone-insulin-like growth factor I (IGF-I) axis in normal pregnancy. METHODS: Totally, 116 normal pregnant women were recruited from January 1997 to June 1998, with 20 normal nonpregnant women as controls. Maternal growth hormone (GH) and IGF-I concentrations were assayed by RIA and enzyme-linked immunosorbent assay, respectively. RESULTS: Maternal serum levels of GH increased throughout gestation, reached a peak at 25 weeks of pregnancy and remained fairly high (chi 2 = 40.458, P < 0.0001). There was a significant difference between samples at 5-9 week gestational age and the controls (3.45 micrograms/L vs 1.61 micrograms/L, P < 0.05). The maternal serum levels of IGF-I increased rapidly throughout gestation from 29-week gestation and reached a peak of 188.86 micrograms/L at term delivery (chi 2 = 50.224, P < 0.0001). CONCLUSIONS: Maternal GH levels increased progressively throughout gestation, which correlated with fetal growth. Maternal GH may regulate nutrition supply among mother, placenta and the fetus and play an important role in transporting nutritional substrates by the placenta. The maternal IGF-I in the third trimester may promote fetal growth and placental functions.

Adult↗
PubMed2001

Vascular endothelial growth factor mRNA and its protein expression in decidua after terminating early pregnancy by mifepristone plus misoprostol.

OBJECTIVE: To investigate the action of mifepristone plus misoprostol on decidua at the level of vascular endothelial growth factor (VEGF) mRNA and its protein expression, as well as the mechanism of prolonged uterine hemorrhage after terminating early pregnancy with these drugs. METHODS: Forty-five decidua specimens were obtained from 45 pregnant women with amenorrhea of 6-7 weeks' duration, in which 15 women were treated with mifepristone and 15 were given mifepristone plus misoprostol. Enzyme-linked immunosorbant assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect VEGF protein and mRNA levels in decidua. RESULTS: In all three groups, only the VEGF121 amplification product of 452 bp was visualized. The mRNA and protein levels of VEGF showed no significant differences among the three groups (P > 0.05). CONCLUSION: In humans, early decidua VEGF121 mRNA is the main isoform. The action of mifepristone plus misoprostol on blood vessels in human decidua may be medicated by some factors other than VEGF.

Abortifacient Agents↗
PubMed2001

Tissue-type plasminogen activator and plasminogen activator inhibitor type-1 mRNA and their protein expression levels in human decidua after early pregnancy termination by mifepristone plus misoprostol.

OBJECTIVE: To investigate the mechanism of prolonged uterine hemorrhage after terminating early pregnancy by mifepristone plus misoprostol. METHODS: Forty-five decidua specimens were obtained from 45 pregnant women with amenorrhea of 6-7 week duration. Fifteen women were treated with mifepristone and 15 were treated with mifepristone plus misoprostol. The remaining 15 served as controls. The tPA and PAI-1 mRNA levels were estimated by reverse transcription-polymerase chain reaction. Chromogenic assay and enzyme-linked immunosorbent assay were used to detect tPA activity and PAI-1 protein level in decidua. RESULTS: The activities of tPA in the mifepristone plus misoprostol group and in the mifepristone group were 46.91 +/- 20.74 IU/mg.protein and 64.25 +/- 35.81 IU/mg.protein respectively, lower than those in the normal decidua group (99.76 +/- 58.61 IU/mg.protein, P < 0.05). tPA mRNA levels in the mifepristone plus misoprostol group were the highest (1.43 +/- 0.39) among the groups. In the mifepristone group, tPA mRNA level (0.90 +/- 0.16) was not significantly different from that in the normal decidua group (0.94 +/- 0.17). The protein and mRNA expression levels of PAI-1 were not significantly different among the three groups (P > 0.05). CONCLUSIONS: Mifepristone plus misoprostol decreased tPA activity in human early decidua by post-transcription pathways, which may influence decidua shedding, endometrial angiogenesis, endometrial remodeling, and cause prolonged uterine hemorrhage after drug abortion.

Abortifacient Agents, Nonsteroidal↗
PubMed2001

[Expression and function of protein kinase C-alpha and beta I isoenzymes in drug-resistant gastric cancer cells].

OBJECTIVE: To study the expression and function of PKC-alpha and beta I isoenzymes in drug-resistant cells of gastric cancer. METHODS: Two tumor cell lines were used in the study: gastric cancer SGC7901 and its drug-resistant counterpart SGC7901/VCR stepwise-selected by various concentrations of vincristine. The expression of PKC-alpha and beta I isoenzymes in SGC7901 and SGC7901/VCR was detected by immunohistochemistry, laser confocal scanning microscopy and Western blot. The effects of anti-PKC-alpha or beta I antibody on adriamycin accumulation in SGC7901/VCR cells were determined by flow cytometric analysis. RESULTS: SGC7901 cells exhibited positive staining of PKC-alpha. The staining of PKC-alpha in SGC7901/VCR was stronger than that in SGC7901 cells. The higher the concentrations of vincristine, the stronger staining of PKC-alpha was observed on SGC7901/VCR cells. Both SGC7901 and SGC7901/VCR cells were positive for PKC-beta I, but without difference in staining intensity. Comparing with SGC7901, SGC7901/VCR cells showed decreased adriamycin accumulation; the decrease was more marked with the increase in concentrations of vincristine for selection of cells. Increased adriamycin accumulation in SGC7901/VCR was observed when co-incubated with anti-PKC-alpha but not anti-PKC-beta I antibodies. CONCLUSION: PKC-alpha may play a role in multidrug resistance of gastric cancer cells SGC7901/VCR.

Blotting, Western↗
PubMed2001

[Clinical study of topotecan in the treatment of small cell lung cancer and recurrent ovarian cancer].

OBJECTIVE: To evaluate the effect and adverse reaction of China made topotecan in the treatment of small-cell lung cancer (ACLC) and recurrent ovarian cancer (OV). METHODS: From January to July, 2000, topotecan was used to treat 141 patients at a dose of 1.2 mg/m2, given daily as 30-min i.v. infusion for 5 days. Treatment was repeated once every 3 weeks. Of the 141 patients, 118 were evaluable for therapeutic efficacy. All the patients received a total of 286 cycles of treatment were assessable for analysis of adverse reactions. RESULTS: Among the evaluable patients, there were 5 CR, 35 PR, with an overall response rate (RR) of 33.8%. There were 3 CR and 26 PR in 89 patients with SCLC (RR 32.5%). The response rate of patients with or without prior chemotherapy was 15.6% and 50%, respectively. In 29 patients with recurrent OV, there were 2 CR and 9 PR (RR 37.9%). The major toxic effect was myelosuppression. Non-hematopoietic toxicities were mild and tolerable. CONCLUSION: Topotecan is an effective drug for the treatment of SCLC and recurrent OV. It is still efficacious in some patients who previously received standard chemotherapy. The major dose-limiting toxicity is myelosuppression. The response rate and toxicity of the domestically made topotecan are comparable with those of the imported one.

Adolescent↗
PubMed2001

[Differential display of vincristine-resistant proteins in gastric cancer cell line SGC7901].

OBJECTIVE: To find out new multidrug-resistant proteins in gastric cancer cells SGC7901 and to explain the new multidrug-resistant mechanism of gastric cancer cells. METHODS: Two-dimensional gel electrophoresis was used with immobilized pH gradients (IPG) to compare the differential expression of multidrug-resistant proteins in gastric cancer cells SGC7901 and Vincristine-resistant SGC7901 cells (SGC7901/VCR) induced by vincristine sulfate. 2-D gels were used to silver stain the protein. RESULTS: Approximately, 680 protein spots were identified in each of the 2-D gel patterns by silver stain. With most of them showing no difference in composition, shape or density, twenty-five proteins were found to differ in quantity (6 higher in SGC7901/VCR cells; 19 higher in 7901 cells). Five proteins were seen to be unique in one region or the others (3 in SGC7901/VCR cells, 2 in 7901 cells). The coordinate position of 30 protein spots in the 2-D gels were listed. CONCLUSION: The results suggest that these differential proteins be related to the vincristine-resistant mechanism in human gastric cancer cell line SGC7901/VCR.

Antineoplastic Agents, Phytogenic↗
PubMed2001

[Effect of hypoxia-ischemia on cysteinyl aspartate-specific proteinases activity in cerebral tissue of neonatal rat].

OBJECTIVE: To study the effect of hypoxia-ischemia on cysteinyl aspartate-specific proteinases (caspase-3) activity in cerebral tissue of neonatal rat and probe into its significance. METHODS: To induce hypoxio-ischemic brain damage (HIBD), the left carotid artery of rats at day 7 was ligated and animals were exposed to 8% oxygen for 2 hours. 0.5, 12, 24, and 48 hours after HIBD, both ipsilateral and contralateral cerebral tissue were ditected and homogenized, caspase-3 activity was measured by cleavage of the colorimetric substrate DEVD-pNA. RESULTS: Caspase-3 activity in ipsilateral cerebral tissue increased gradually after HIBD and peaked at 24 hours, and then decreased significantly at 48 hours(P < 0.001). There were no significant changes in caspase-3 activity in the contralateral tissue at all time points (P > 0.05). CONCLUSIONS: Significant activation of caspase-3 after cerebral hypoxia-ischemia strongly suggests that apoptosis is involved in HIBD. Application of caspase inhibitors or other anti-apoptotic agents may become a new therapeutics of HIBD.

Animals↗
PubMed2001

[Relationship between follicular development and insulin like growth factor I receptor in stimulated cycles].

OBJECTIVE: To investigate the number of follicles and insulin-like growth factor I receptor (IGF-I R) in stimulated cycles. METHOD: IGF-I R mRNA and IGF-I R in granulosa cells obtained during oocyte retrieval were respectively measured by reverse transcript polymerase chain reaction (RT-PCR) and Western blot technique. RESULTS: The expression of IGF-I R mRNA in poor responders (follicles < or = 3) was much lower than in normal responders (follicles 4-13) and high responders (follicles > or = 14) (1.70 +/- 0.23, 2.92 +/- 0.49, 4.22 +/- 1.50 respectively). Similar results were obtained for IGF-I R (1.32 +/- 0.31, 2.01 +/- 0.72, 4.39 +/- 2.31 respectively). CONCLUSION: The expression of IGF-I R correlated with the effects of gonadotropin hormone on follicular development.

Adult↗