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Biomedical subjects

S Li

Publications and source records attributed to S Li.

At least 739 records · Page 41Linked to original sources
PubMed1999

[The vision distribution and causes of blindness in elderly population in Doumen county].

OBJECTIVE: To investigate the vision distribution and the leading cause of blindness in farmer aged >or= 50 years in Doumen county. METHODS: Cluster sampling size was estimated within an error bound of 0.35% with 95% confidence limit, 1.25 design effect and 85% response rate. Presenting visual acuity was measured by ETDRS (early treatment diabetic retinopathy study) tumbling chart. Eye examinations of external eye, anterior chamber, lens, fundus and intraocular pressure were carried out by ophthalmologists. A diagnosis of the principal cause for all the eyes with presenting visual acuity less than 0.3 was made as well. The field survey was conducted by two teams after pilot agreement testing. RESULT: 5,342 individuals were examined in 36 sampling units. The prevalence of blindness was five-fold in the group aged >or= 70 years than in the group 50 - 59 years. The rate of blindness in the group with less education was higher than the group with 5 years schooling. The leading causes of blindness were cataract (44.90%), cornea opacity (16.36%), globe disorders (10.76%), refractive error (7.08%) and glaucoma (5.88%). CONCLUSIONS: The prevalence of blindness and low vision was 2.67% and 19.91%, respectively in farmers aged >or= 50 years. The leading cause of blindness was cataract.

Age Distribution↗
PubMed1999

[A study on visual function and quality of life in elderly population].

OBJECTIVE: To evaluate the visual impairment by visual function and quality of life assessment in elderly population. METHOD: All subjects aged >or= 50 years were identified by randomly clustering sampling. Visual Function and Quality of Life Questionnaire (VF/QOL) was administered by 5 interviewers for all subjects with presenting visual acuity less than 0.1 in at least one eye (as visual impairment group) and part of the subjects with presenting visual acuity better than 0.3 in both eyes (as control group). RESULTS: Five hundred and thirty-five eligible visual impairment subjects (90.8%) and 119 control subjects were successfully interviewed. In a 0 - 100 scores' scale, the subjective VF and QOL mean scores were 51.0 and 65.9 respectively. The mean score was correlated with age, sex and education. Mean VF and QOL scores decreased from 84.4 and 93.4 to 14.6 and 31.2 along with the visual status worsening from normal to severe blindness respectively. In stepwise linear regression model, the VF and QOL scores were significantly correlated with age and education instead of sex. CONCLUSIONS: In elderly population with visual impairment, subjective visual function and quality of lift status are deteriorated substantially. Their scores are significantly correlated with age and education.

Aged↗
PubMed1999

[Long-term effect of extra-trabeculectomy in treatment of congenital glaucoma].

OBJECTIVE: To assess the long-term effect of extra-trabeculectomy in treatment of congenital glaucoma. METHODS: 29 patients (47 eyes) with congenital glaucoma having undergone extra-trabeculectomy were followed up for over 5 years. RESULTS: Success rates after single surgery were 70.2% at 6 months, 63.8% at 12 months, 57.5% at 18 months and 55.3% at 24 months. Re-elevation of intraocular pressure (IOP) all happened within 2 years after surgery. 14 eyes underwent second trabeculectomy, and 7 eyes (50.0%) were successful the total success rate was 70.2%. The naked visual acuity of 12 eyes (36.0%) among successful eyes was >or= 0.5. All the diseased eyes were myopic (-0.50 to -25.00 D). CONCLUSION: Follow-up of trabeculectomy should be emphasized within 2 years after surgery. Ametropic and anisometropic amblyopia should be corrected promptly after surgery.

Child, Preschool↗
PubMed1999

[The prevalence of cataract in Doumen County, Guangdong Province].

OBJECTIVE: To investigate the prevalence of cataract, cataract blindness and the cataract burden in population aged >or= 50 years in Doumen County. METHOD: 5,759 individuals aged >or= 50 were identified from sampling units. The definition of cataract was the vision < 0.7 caused by lens opacity in either eye, among them the person whose vision in both eyes was < 0.1 was cataract burden and whose vision in both eyes was < 0.05 was cataract blindness. RESULT: The response rate was 92.76%. The prevalence of cataract, cataract blindness and cataract burden was 20.93%, 1.67% and 3.86%, respectively. CONCLUSION: The huge community necessary for cataract surgery still remains as a great challenge in China.

Age Factors↗
PubMed1999

[Effects of methylmercury on embryonic cell behavior and expression of related gene].

OBJECTIVE: To explore the mechanism of embryonic developmental toxicity of methyl mercury at cellular and gene levels. METHODS: Effects of methylmercury on embryonic cell behavior and gene expression in rats were observed with in vitro (0, 0.05, 0.10, 0.20, 0.40, 0.80 and 1.60 mg/L of methylmercury) and in vivo (0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg/L of methylmercury) rat models, in situ hybridization and TdT-induced dUTP nick end labeling techniques. RESULTS: Methylmercury could pass through yolk-sac placenta quickly, and inhibit placenta development and blood vessel differentiation there at higher concentration. There was a dose-response relationship between concentration of methylmercury and its embryonic developmental toxicity. Its developmental toxicity mainly characterized as patent neural tube and anomalous flexion. Methylmercury could induce excessive apoptosis of embryonic cells, inhibit apparently the synthesis of cellular DNA and RNA and damage its cellular ultrastructure. It also could induce significantly the expression of heat shock protein 70 mRNA and inhibit the expression of fibronectin and p16 mRNA. There was relationship between heat shock protein 70 mRNA, Ca(2+), apoptosis and teratogenesis. CONCLUSION: Disturbance of embryonic cell behavior and related gene expression played important roles in developmental toxicity caused by methylmercury.

Animals↗
PubMed1999

[Effects of homocysteine on cardiovascular development in early chicken embryo].

OBJECTIVE: To study the relationship between homocysteine (HCY) and cardiovascular development in the early embryo and to determine whether folic acid and cobalamine (Vit B(12)) can reduce the developmental toxicity of HCY to cardiovascular system. METHODS: Incubation test for chicken embryo, electron microscopy, methylgreen-pyronine stain, in situ fragment end labeling, and intervention trial with folic acid and vitamin B(12) were used in the study. RESULTS: Treatment of 0 - 16.0 micromol of HCY/per embryo could disturb their heart development and differentiation of blood vessels at fetal ages of two and four days, in a dose-response pattern, with 24.1% and 25.0% of heart defect and 60.7% of inhibition of blood vessels of yolk sac in 8.0 micromol of HCY, respectively. A dose of more than four micromol/per embryo could damage the structure of myocardial cells and organelle, and inhibit the synthesis of cellular DNA and RNA. It was the first time to find that 8.0 micromol of HCY could induce excessive apoptosis of myocardial cells (2.7%), significantly higher than that in the normal control group. Folic acid could antagonize the cardiovascular toxicity caused by HCY, stronger than what Vit B(12) could do. CONCLUSION: HCY was a new risk factor which could damage cardiovascular development, and folic acid could effectively antagonize its developmental toxicity. Cellular apoptosis might relate to cardiovascular defect.

Animals↗
PubMed1999

[A case-control study on cerebral palsy in children].

OBJECTIVE: To identify the risk factors for cerebral palsy (CP) in children. METHODS: A population-based 1:2 matched case-control study was conducted during May to June 1997 in southern Jiangsu Province of China. RESULTS: Risk factors for CP in children could be summarized into four categories, i.e.; (1) fetal growth retardation, preterm delivery and low birth weight; (2) asphyxia at birth, intracranial hemorrhage, ischemic and hypoxic encephalopathy and hyperbilirubinemic encephalopathy; (3) delivery with vaccum suction and traumatic brain injury; and (4) other prenatal factors. CONCLUSION: The first and second categories of risk factors correlated strongly and reproducibly with CP in children. It is emphasized that antenatal care be enforced to prevent occurrence of risk factors, such as low birth weight, etc., and the newborns with asphyxia be vigorously rescued and put under close supervision. For risk factors in the third category, the key measures should be obstetric practice and health education for the parents. But, little about the knowledge of the risk factors in the fourth category has been understood, which could be associated with those in the first two categories.

Asphyxia Neonatorum↗
PubMed1999

[Studies on male reproductive toxicity caused by hexavalent chromium].

OBJECTIVE: To study male reproductive toxicity caused by hexavalent chromium (Cr(VI +)). METHODS: Morphology of semen and spermatozoa was observed and chromium level in blood, chromium and zinc level in sperm plasma, leuteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in serum were determined for male workers exposed to (Cr(VI +)) (CrO(3)X = 0.0195 mg/m(3)) with occupational epidemiologic investigation and laboratory analysis. RESULTS: For the exposed workers, their seminal counting was (52.21 +/- 45.51) x 10(9)/L, and zinc level in seminal plasma (4,811.85 +/- 1,401.88) micromol/L, significantly lower than those in controls (88.96 +/- 74.82) x 10(9)/L and (5 718.49 +/- 2 827.90) micromol/L, respectively, P < 0.05. Serum FSH was (7.34 +/- 6.88) IU/L in the exposed groups, significantly higher than that of controls (2.41 +/- 1.69) IU/L, P < 0.01. There were no significant difference in semen volume, semen liquefaction time, prevalence of teratospermia, serum Cr(VI +) and LH level in seminal plasma between exposed group and control group (P > 0.05). Prevalence of teratospermia was 0.24 +/- 0.09, and serum LH and FSH were (7.94 +/- 2.67) IU/L and FSH (9.33 +/- 6.47) IU/L, respectively, in workers exposed to high concentration of Cr(VI +) (CrO(3)X = 0.2351 mg/m(3)) significantly higher than those exposed to lower concentration of Cr(VI +) (CrO(3)X = 0.0172 mg/m(3)), with 0.17 +/- 0.06 of prevalence of teratospermia, (5.05 +/- 3.05) IU/L of LH, and (3.74 +/- 3.04) IU/L of FSH, respectively (P < 0.05). CONCLUSION: The results suggested that damage to convoluted seminiferous tubules epithelium, reduction of spermatozoa formation and increase in prevalence of teratospermia could be caused by exposure to certain concentration of Cr(VI +).

Adult↗
PubMed1999

[Diagnosis and differential diagnosis of primary carcinoma of female peritoneum].

OBJECTIVE: Histogenesis and morphological features of 6 primary carcinomas of female peritoneum were studied. METHODS: H&E staining, histochemical stainings and immunohistochemical stainings were used. RESULTS: Among 6 primary carcinomas there were 4 cases of serous papillary carcinomas, 1 case of endometrioid carcinoma and 1 case of transitional cell carcinoma. CONCLUSION: Primary carcinomas of the female peritoneum were histologically identical to that of the similar epithelial carcinomas arising from the ovaries. The diagnosis was made only when the ovaries are not involved and without no any evidence of similar epithelial carcinoma obtained in the ovaries, uterus or urinary organs. These tumors are considered arising from the secondary Mullerian system. D-PAS and CEA staining are helpful as the accessory criteria for the differential diagnosis between primary carcinoma of the peritoneum and malignant mesothelioma.

Adult↗
PubMed1999

[Effects of p21WAF1/CIP1 gene introduction on a human lung cancer cell line with p53 mutation].

OBJECTIVE: To study the effects of p21WAF1/CIP1 gene expression on the biological hehavior of cancer cells with p53 gene mutation. METHODS: Expression of p21 vehicle was constructed and introduced into a human lung cancer cell ling PG with p53 gene mutation, the morphological and growth characteristics of the transfectant were then analysed. The CDK4 and PCNA levels were evaluated and the response to genotoxic agents were observed. RESULTS: The PG cells with mutant p53 were transfected with ectopic p21 gene which resulted in overexpression of p21 (6-fold of the control). The transfectants presented decreased nuclear irregularity and thinner membrane in nuclear atypia, with delayed growth rate and contact growth inhibition. The transfectant also displayed high serum requirement in culture and increased anchorage dependence. Both levels of CDK4 and PCNA were decreased. However, the cisplatin induced cell apoptosis was delayed. CONCLUSIONS: Expression of p21WAF1/CIP1 gene was effective in cancer suppression even in p53 gene mutation. This may have been achieved through lowering of CDK4 or PCNA levels and not involving the apoptosis mechanism. Activation of p21WAF1/CIP1 gene may be considered a bypass for restoration of p53 gene function in cancer cells with p53 gene mutation.

Antineoplastic Agents↗
PubMed1999

[Use of color Doppler esophageal ultrasonography for assessing hemodynamics of the lower esophageal veins before and after endoscopic esophageal variceal ligation].

Using color Doppler esophageal ultrasonography(CDEUS) with water balloon, we examined the lower esophageal veins of 24 patients with portal hypertension and esophageal varices. The results showed that CDEUS with water balloon could clearly display the lower esophageal veins and could effectively evaluate the changes of hemodynamics of the lower esophageal veins before and after endoscopic esophageal variceal ligation. The maximum blood velocity of peri-esophageal vein in the active bleeding group was higher than that in the non-active bleeding group.

Endoscopy, Digestive System↗
PubMed1999

[Relationship between the effect of carbamazepine on SCE frequencies and folic acid in epileptic patients].

Peripheral blood lymphocyte sister chromatid exchange(SCE) frequencies, serum folic acid(FA) levels were examined in 15 epileptic patients treated with carbamazepine(CBZ), and another 15 epileptic patients treated with CBZ and folic acid(FA). The untreated epileptic patients and the healthy subjects served as control. The results showed that SCE frequencies were significantly higher in CBZ Group, compared with CBZ plus FA Group and control(P < 0.01). Serum FA levels were lower in CBZ Group compared with healthy control(P < 0.01). It suggests that CBZ can induce the increase of SCE frequencies. Supplementation with FA may effectively prevent chromosome DNA damage induced by CBZ.

Adolescent↗
PubMed1999

[Studies on chemical constituents in the fruit of Canarium album Raeusch].

OBJECTIVE: To study the chemical constituents in the fruit of Canarium album. METHOD: Compounds were isolated by chromatography and elucidated on the basis of spectroscopic analysis. RESULT: The compounds obtained were determined as scoparone, scopoletin, (E)-3,3'-dihydroxy-4,4'-dimethoxystilbene and gallic acid. CONCLUSION: All the compounds, except gallic acid, were obtained from this plant for the first time.

Burseraceae↗
PubMed1999

[Effect of puerarin on coronary collateral circulation in dogs with experimental acute myocardial infarction].

OBJECTIVE: To evaluate the effect and mechanism of puerarin on coronary collateral circulation in dogs with experimental acute myocardial infarction. METHOD: Twelve dogs were randomly divided into puerarin (Gegen su, G) group and control(C) group, the acute myocardial infarction model was built in all dogs. Puerarin or saline was administered for 21 days. Coronary angiography was performed before and after ligating coronary artery. The capillaries and distribution vessel density in tissue sections of myocardium were assessed. RESULT: Angiography on hour 2 and day 22 after ligating coronary artery revealed significant augmentation of collateral vessels in G group versus controls. Capillaries and distribution vessel density in ischemic and infarctive zone on day 22 revealed statistically significant augmentation in G group versus controls (P < 0.05 and P < 0.01). CONCLUSION: Puerarin might improve the opening and forming of coronary collateral circulation to ischemic myocardium in dogs and protect ischemic myocardium.

Animals↗
PubMed1999

[Studies on variations of alkaloids in zhebeimu (Fritillaria thunbergii Miq.) by improved colormetric determination].

OBJECTIVE: To find out the seasonal variation of active alkaloids in Zhebeimu(F. thunbergii) collected from Zhejiang Ninbo and Jiangsu Nantong, and confirm the suitable harvesting time for the crude drug. METHOD: Determining the alkaloid contents in the samples of Zebeimu collected monthly from the above-said twoplaces by improved colormetric method. RESULT: The alkaloid accumulation patterns of the samples from two places are very similar, with the highest contents appearing in samples collected in January of February, and the absolute amounts in samples harvested in May. CONCLUSION: The optimum time for harvesting Zhebeimu is in May.

Alkaloids↗
PubMed1999

[The RYR1 genotype of the pigs from Neijiang of China].

The aim of this study was to test the RYR1 genotype of 25 Neijiang pigs ao as to provide data for the selective breeding of medical experimental pig strains. PCR-RFLP technique was used. The results showed that the RYR1 genotype of all the 25 porcine cases was HALNN and all of the 25 porcine cases were Halothane Negative. These suggested that Neijiang pig could be one of the porcine strains selectively bred for medical experiments and clinically for pig-to-human xenotransplantation. PCR-RFLP technique is a reliable and simple method for RYR1 gene testing.

Animals↗