Biomedical subjects

N Li

Publications and source records attributed to N Li.

At least 145 records · Page 8Linked to original sources

PubMed2001

[Study of the association between human papillomavirus infection and cervical cancer in Xianguan county, Shanxi province].

OBJECTIVE: To investigate human papillomavirus (HPV) prevalence in the high incidence areas of cervical cancer in Shanxi and to study the association between HPV infection and cervical cancer. METHODS: Cells exfoliated from cervix (collected by clinician) and from vagina (collected by subject herself) of 1997 women aged 35-45 from Xiangyuan county, Shanxi province were analyzed blindly by Hybrid Capture Assay (HC-II), which could detect 13 HPV types of high-risk. Unconditional logistics regression model was used to analyze the relation between HPV and cervical cancer/cervical intraepithelial neoplasia (CIN). Kappa coefficient was used to compare the agreement of the two tests. RESULTS: HPV DNA detection rate in the population was 20.8% while HPV infection rates increased with the seriousness of cervical lesions (chi 2 = 444.04, P = 0.000). Rates of the two groups (35-39 and 40-45) had no significant difference (20.9%: 20.6%, chi 2 = 0.03, P = 0.86). Unconditional logistic regression analysis showed, when comparing with the normal subjects, the risk odds ratio of HPV infection with cervical cancer/high grade CIN and low grade CIN were 254.2 and 26.4 respectively, with attributable risk proportions (ARP) 98.1% and 83.6% respectively. The sensitivity of self-collected vaginal swabs assayed for HPV DNA was lower than that of clinician-collected cervical samples assayed for HPV DNA (84%: 98%, chi 2 = 5.92, P = 0.015). No significant difference in specificity was seen between them (86%: 85%, chi 2 = 0.00, P = 0.997) and there was fair agreement between the two tests (kappa = 0.74). CONCLUSION: High-risk HPV infection in female genital tract was the major risk factor of cervical cancer and CIN in the areas. Prevention and control of cervical cancer should be focused on avoiding HPV infection, screening women for HPV infection and monitoring population infected by high-risk HPV. Self-collected vaginal swabs assayed for HPV DNA seemed a more practical method in primary screening for cervical cancer.

Adult↗

PubMed2001

[The research of pancadherin and beta-catenin expression in pulmonary tissue of mice with bleomycin-induced pulmonary fibrosis].

OBJECTIVE: To investigate the changes of pancadherin(Pan-cd) and beta-catenin(beta-cat) expression in pulmonary tissue of mice with bleomycin (BLM)-induced pulmonary injury and explore the relation between the Pan-cd/beta-cat expression and pulmonary fibrosis. METHOD: A single dose of BLM was intratracheally injected to induce pulmonary fibrosis of mice. Animals were killed and immunohistochemical methods were used with polyclonal anti-Pan-cd and anti-beta-cat antiserum. RESULTS: The expression of Pan-cd in type I alveolar cells was down-regulation. The expression of Pan-cd in type II alveolar cells was induced. The expression of Pan-cd and beta-cat in small airway epithelial cells were all down-regulation and were repeated with the way of down-regulation-reparation-down-regulation. The expression of Pan-cd on membrane in small airway epithelial cells decreased, whereas the cytoplasmic expression increased and was repeatedly alternated between cytoplasma with membrane. The expression of Pan-cd in alveolar macrophage and interstitial cells increased. CONCLUSION: The abnormal expression of cadherin and beta-cat may play a role in the pathogenesis of pulmonary fibrosis after pulmonary injury.

Animals↗

PubMed2001

[Study on the prevalence rate of primary osteopenia in the middle-aged and the elderly population in some parts of China].

OBJECTIVE: To understand the distribution of prevalence rate of primary osteopenia (POPA) in the middle-aged and the elderly in some parts of China. METHODS: Bone mineral density (BMD) was measured and questionnaire was administered to 5 600 people aged above 40 in five administrative areas in China, through a stritified-multi-steps-cluster sampling method. RESULTS: The total prevalence rate of primary osteopenia in some parts of China was 15.8%, according to the most significant parts of the rate of loss. Of them, the prevalence rate of males was 20.0% compared to 12.4% in females (P < 0.01); There were also differences on POPA prevalence among provinces, age groups and areas between urban and rural (P < 0.01). CONCLUSION: Although prevention and treatment of primary osteopenia were important strategy in males however it should not be ignored in females as well.

Adult↗

PubMed2001

[A survey and treatment of blindness in Gejiu City of Yunnan Province].

OBJECTIVE: To calculate the percentage of blindness in the mass and evaluate the current conditions of treatment for cataract. METHODS: In accordance with the national unified standards and procedures, a clue survey of the people aged under 40 years and a general survey of the people over 40 years in Gejiu city, Yunnan province were carried out. In the mean time, operations were performed for the patients with cataract. RESULTS: Of the total 361 214 persons being surveyed, there were binocular blindness in 1 037 cases (0.29%) and monocular one in 983 cases (0.27%). Of the cases with binocular blindness, 593 cases (57.18%), and of the monocular blindness, 617 cases (62.77%) could be treated. The leading causes of 1037 cases with binocular blindness were cataract (51.98%), injuries of the eye (19.96%), corneal opacity (16.00%), glaucoma (10.03%), refractive error and other ocular diseases (2.03%). The average prevalence rate in the female cases was higher than that of male cases (chi(2) = 53.48, P < 0.01). Blindness was associated with older age There were variations in the prevalence rates in different aboriginals and in cases with different occupations. Cataract was the main disease to cause both the monocular and binocular blindness. Among the patients with cataract 539 cases (90.98%) of binocular blindness and 500 cases (81.03%) of monocular blindness were curable. The cataract operation was performed on 738 cases with cataract, including 396 cases with binocular blindness and 342 cases with monocular blindness. At postoperative 3 months, the rate of the best corrected visual acuity (eye sight > 0.05) was accounted for 97.73%, the rate of the eye sight > 0.3, 86.36% and the rate of wearing glasses (including implantation of intraocular lens), 85.60%. CONCLUSION: The prevalence of blindness is associated with the aboriginal, occupation, age and the sex. The leading cause of blindness is cataract. So the surgical restoration of vision in cases with cataract is the main measure in the prevention of blindness.

Adolescent↗

PubMed2001

[An experimental study on subconjunctival interleukin-1 receptor antagonist for promotion of corneal transplant survival].

OBJECTIVE: To determine whether the subconjunctival application of interleukin-1 receptor antagonist (IL-1ra) can prolong the corneal graft survival in the rat model of orthotopic penetrating keratoplasty. METHODS: For all experiments, F344 corneas were transplanted into LOU (major histocompatibility-disparate) eyes. Experimental groups received subconjunctival injection of 50, 100 and 200 microg IL-1ra respectively, and the control group received the same volume of 0.9% normal saline instead for consecutive 2 weeks. All transplants were evaluated for 4 weeks after surgery for signs of rejection. RESULTS: The mean survival time (MST) of the grafts of the experimental groups was increased significantly (t = 0.00, P < 0.01) in comparison with the control group. The MST of the IL-1ra 200 microg group was increased significantly than that of the IL-1ra 50 microg group (t = 0.00, P < 0.01). Furthermore, the IL-1ra-treated grafts had significantly less corneal inflammation, infiltration, lower levels of opacity, edema, neovascularization and rejection index compared with the control group. CONCLUSIONS: Subconjunctival treatment of IL-1ra has a significantly positive effect on promoting corneal allograft survival. And its effect is dosage-dependent.

Animals↗

PubMed2001

[Intramandibular course and anatomic structure of the inferior alveolar nerve canal].

OBJECTIVE: To study the intramandibular course and anatomic structure of mandibular canal. METHODS: The intramandibular course of mandibular canal and its dimension were measured in 15 adults mandibles with teeth; the relationship between blood vessel and nerve was observed in 4 fresh samples in which the artery was filled. RESULTS: The mandibular canal was close to the lingual side and the inferior margin of the mandible. The blood vessel lay above nerve in the mandibular canal. CONCLUSIONS: In implant operation performed according to normal anatomy, injury to inferior alveolar nerve may be avoided. Hemorrhage is the earliest manifestation suggesting that continuing drill may damage the inferior alveolar nerve.

Adult↗

PubMed2001

[Study on the genetic variations of the major neutralization antigen VP7 of group A rotavirus type G1 in China].

OBJECTIVE: To study the genetic variations of the major neutralization antigen VP7 of group A rotavirus, type G1 in China. METHODS: Twenty-three isolates derived from seven cities (Beijing, Shenyang, Xinxiang, Shanghai, Shenzhen, Guangzhou and Chongqing) during the period of 1988-1998 were analyzed for the VP7 cDNA sequences. RESULTS: An obvious homology was observed in amino acid sequences of VP7 in the 23 isolates. Compared with the standard strain Wa, the variations were found at the position of aa 41, 49, 57, 65, 68, 74, 94, 97, 147, 170, 217, 218, 268, 281 and 291, respectively, and all of these were located in the variable region(VR)3,4,5,7,8 as well as in the C-terminal of the peptide. There seemed to be no remarkable divergence among the samples collected from different cities and all of them shared the same genetic lineage with the strain Jpn-417, though there might be one or two amino acid substitutions as time passed. When detected simultaneously with ELISA using G1 serotype-specific monoclonal antibody, the location of amino acid 91 was found presumably related to the neutralization epitope in VP7 of the type G1. Variations at some position may be resulted in the change of electropherotype. CONCLUSIONS: The results indicated that the recent isolates with representative genetic and antigenic features should be used to develop effective vaccines, and the antigenic variations should be monitored periodically.

Amino Acid Sequence↗

PubMed2001

[Preliminary investigation of the relationship between liver lesion and relevant factors in young children with rotavirus diarrhea].

OBJECTIVE: To investigate the possibility of liver lesion and its relationship with the relative factors in young children with rotavirus(RV) diarrhea. METHODS: The values of ALT and AST in sera of young children with RV diarrhea were measured to be compared with those of common diarrhea and were analyzed with the multifactors about diarrhea. The genomes of RV from blood serum were tested with reverse-nest polymerase chain reaction. RESULTS: Of the 41 young children with RV diarrhea, 15(36.6%) and 32 cases (75.6%) were abnormally higher in the level of ALT and AST respectively and both the ratio and degree of increase were significant in comparison with that in control group. There was no significant relation between the changes of the values of ALT and AST and the clinical manifestation of diarrhea. 4 out of 41 cases were found to be positive of viremia. CONCLUSION: RV infection might spread from intestine to blood and to other organs resulting in viremia, and the liver may be one of the organs involved.

Child, Preschool↗

PubMed2001

[Assessing health state utility using the short form 36].

OBJECTIVE: To explore the methods of utility assessment using the short form 36. METHODS: The authors selected 70 people stratified by age, sex, and occupation in a city in Sichuan province, and investigated the preference of the population on each domain or item by paired comparison with other domains or items. Based on the preference, the weights of the domains and items were calculated. RESULTS: The weights of all the 8 domains and the items within 7 domains except the first domain "physical functions" were identified. The total score and the scores of the domains calculated by weighted adding method were significantly different from those calculated by simple adding method. However, only little variation of the scores of the domains between the two methods appeared. CONCLUSION: Utility calculated by weighted adding method may reflect people's preference to the health states more accurately. However, the value is limited in using weighted adding method for calculating the scores of domains.

Activities of Daily Living↗

PubMed2001

[High concentration ethanol continuous fermentation using yeast flocs].

Continuous ethanol fermentation using yeast flocs was carried out in 4 air-lift suspended-bed bioreactors operated in series. Drafted by CO2, with complete recycle of ethanol distilled effluent broth and at the dilution rate of 0.2/h, the average ethanol concentration of the fermentation broth was 96.6 g/L, while the average concentration of residual total sugar was 4.1 g/L and residual reducing sugar was 1.2 g/L.

Bioreactors↗

PubMed2001

[In vitro metabolic studies of the novel anti-anxietic drug AF-5 and its metabolites in human liver microsome incubation system].

AIM: To study the metabolism of a novel anti-anxietic drug AF-5 and its metabolites (I, II) in human liver microsome incubation system. METHODS: Human liver microsomes were prepared, the enzyme activity was determined to be 8.79 mg.mL-1 by Lowry's method. The human liver microsome incubation system consisted of: human liver microsomes 2 mg.mL-1, glucose-6-phosphate (G-6-P) 0.01 mmol.mL-1, glucose-6-phosphate dehydrogenase (G-6-PDH) 1 U.mL-1, magnesium chloride (MgCl2) 4.0 mumol.mL-1, coenzyme II in oxidized form (NADP) 0.5 mumol.mL-1, and coenzyme I in reduced form (NADH) 1.0 mumol.mL-1. Two milligrams of AF-5 solubilized by Tween 80 was then added, the mixture was diluted to 5 mL with Tris-HCl solution and the mixture was incubated in a 37 degrees C water bath with shaking. Oxygen was passed over the liquid surface for 0.5 min every 20 minutes. The incubation was carried out for 40 min and 100 min respectively. Three volumes of ethyl ether were added to stop the metabolism, and more ethyl ether was used to extract the metabolites for 3 times. The ether extracts were pooled together, dried with anhydrous sodium sulfate, then evaporated to dryness. The residue was dissolved in 0.5 mL n-hexane and analyzed by GC/MS under the following conditions: 150 degrees C (1 min)[formula: see text]180 degrees C (1 min)[formula: see text]260 degrees C (2 min), in the total ion current mode, EI: 70 eV, interface temperature: 250 degrees C, ion source temperature: 200 degrees C. RESULTS: Two major metabolites were found and identified in this incubation system, and demonstrated that the in vitro metabolic pathway was that the carbon 4 was first oxidized to hydroxyl group, then further oxidized to a carbonyl group. CONCLUSION: In human liver microsome incubation system AF-5 was completely metabolized in 100 min to the hydroxy derivative I and carbonyl derivative II, with hydroxymetabolite as the major metabolite. Metabolite I was further transformed to metabolite II, which was not metabolized any further by the human liver microsomes.

Anti-Anxiety Agents↗

PubMed2001

[Factors that influence the quality of life of Sichuan population].

OBJECTIVE: To investigate the risk factors influencing quality of life with the aim of providing evidence for valid health promotion measures. METHODS: The authors used the short form 36 to assess the quality of life of 2249 residents in Sichuan Province. The data of potential risk factors including social economic status, culture, chronic condition and personal characteristics were collected. The Student t test, variance analysis, and stepwise multivariate regression methods were used to test the impacts of different risk factors on quality of life. RESULTS: Chronic condition, age, sex, educational level, marital status, occupation, personal income, number of family members, number of generation in a family, inhabitant places (urban or rural), and way of payment of medical expenditure were correlated with all or most of the domains of the short form 36 in t-test or one-way variance analysis. When the effect of interaction between factors were excluded by use of multivariate regression, the chronic condition, personal income, inhabitant places, age, and educational level remained to be significant risk factors. Marital status also had impacts on a few domains. CONCLUSION: The key steps of promoting the quality of life should include the prevention and control of chronic conditions, the development of economy, and the improvement of people's income and educational level. It is necessary to provide norms of the short form 36 stratified by inhabitant's place and age. Further research would be needed to provide evidence for the necessity of norms stratified by sex.

Adolescent↗

PubMed2001

[Assessing the quality of life of people with chronic diseases using SF-36].

OBJECTIVE: To analyze the influence of chronic diseases on the quality of life by using short form of 36 (SF-36). METHODS: Four hundred and thirty-eight people with chronic diseases were surveyed in a township and a city in Sichuan Province. The diseases were classified according to ICD-9 and the quality of life of people with chronic diseases of different systems was analyzed. RESULTS: The quality of life of people with chronic diseases of different systems was lower than that of general people aged 40 or above. The quality of life varied among people with chronic diseases of different systems in four fields, namely PF, SF, VT and MH. The main diseases that influenced the quality of life were mental disorders, infectious and parasitic diseases, the diseases of blood and blood-forming organs. CONCLUSION: The chronic diseases have decreased the quality of life. The diseases of different systems have had different influences on the quality of life. SF-36 is suitable for assessing the quality of life of people with chronic diseases. Quality of life should be taken as an important health index in chronic disease control and prevention.

China↗

PubMed2001

[Scaling the SF-36 in a Chinese population].

OBJECTIVE: To facilitate the cross-cultural comparison, we employed the principles of fuzzy mathematics in scaling the SF-36 in a Chinese population. METHODS: We stratified an urban population according to the age, sex, and occupation, and selected 650 people to participate in the study. A total of 646 valid questionnaires were returned. In the 8 domains of the SF-36, the interval estimation of the scores of different alternative answers of 6 domains which have more than 2 alternative answers were conducted. RESULTS: The fuzzy degrees of most interval estimations were less than 0.5, except 4 estimations in the domain "physical functions". The ordering of the scores of 8 domains was more similar to the original assumption by our scaling criteria than by the US scaling criteria. CONCLUSION: The scaling criteria set in this study is more suitable for use in Chinese population and we suggest that the alternative answers of the domain "physical functions" be simplified to "yes" and "no".

Activities of Daily Living↗

PubMed2001

[Feasibility of using short form 36 in Chinese population].

OBJECTIVE: To explore the feasibility of using the SF-36 in Chinese population. METHODS: We tested the reliability and validity of the SF-36 in 1603 rural residents, 646 urban residents, 70 high school girls, 122 patients with osteoporosis, and 150 stroke patients. RESULTS: The reliability and validity of the SF-36 in general were acceptable, however, the reliability and validity varied among different domains and in different populations. The reliability and validity of the domains "limitations in physical activities", "limitations in usual role activities because of physical health problems", "bodily pain", and "general health perception" were better than those of the domains "vitality", "limitations in social activities", "limitations in usual role activities because of emotional problems", and "mental health". CONCLUSION: The results indicate that we can use the SF-36 in Chinese population, but we have to pay attentions to the variance of the reliability and validity in different populations, especially for the interpretation of the results of the domains related to mental and social functions.

Activities of Daily Living↗

PubMed2001

[The norms of SF-36 scale scores in urban and rural residents of Sichuan province].

OBJECTIVE: To develop the norms of SF-36 in Sichuan, China. METHODS: A total of 1603 rural residents and 646 urban residents were surveyed. Both the US scaling criteria and China scaling criteria were used to score the 8 domains of the SF-36 and compared with the norms of Hong Kong and US populations. RESULTS: The scores of the 8 domains of the SF-36 using China scaling criteria were highly correlated with those using the US scaling criteria, with correlation coefficients greater than 0.98, however, the mean scores using the two scaling criteria were different significantly. The norms of the Sichuan population were more similar to the Hong Kong norms than the US norms. The scores of the SF-36 were different between different age and sex groups and between urban and rural populations. CONCLUSION: We have developed the norms of SF-36 by age/sex groups in urban and rural population of Sichuan, China.

Activities of Daily Living↗

PubMed2001

[Glutamate induced modulation of free Ca2+ in isolated inner hair cells of the guinea pig cochlea].

OBJECTIVE: To investigate the modulation effect of glutamate (Glu) on intracellular free Ca2+ concentration([Ca2+]i) of inner hair cell (IHC). METHODS: Using the laser scanning confocal microscope (LSCM), the exogenous Glu-induced changes in [Ca2+]i of isolated 10 IHCs and 10 OHCs of guinea pig cochlea were observed with fluo-3, a fluorescent probe for [Ca2+]i. RESULTS: The IHCs were identified by their unique flask shape with a distinct neck and spherical base and a large spherical nucleus. In most cases, normal cell shapes could be maintained about two hours after isolation. The images of [Ca2+]i from LSCM were similar to those from inverted microscopy. Fluorescence of Fluo-3 distributed in the isolated IHCs with brighter staining in the nucleus. In the presence of low concentration of Glu (3.85 mumol/L), there was an increase of [Ca2+]i in IHCs, whereas no change in OHCs was found. Of the 10 IHCs, increases of [Ca2+]i were observed in 9 and no change in 1. Of the 10 OHCs, 7 showed no [Ca2+]i change and only 3 showed minor reduction of [Ca2+]i. An increase of the Glu concentration (21.88 mumol/L) induced a corresponding increase of [Ca2+]i in IHCs, but eventually resulted in a gradual decrease of [Ca2+]i with a distortion of the normal shape, which indicated that the IHCs were degenerated and swelling. CONCLUSION: These results suggested that exogenous Glu is capable of modulating [Ca2+]i of IHC and may be act on autoreceptor in a positive feedback manner. Excessive Glu induced the accumulation of IHC [Ca2+]i which finally resulted in the degeneration and edema of IHC and the reduction of IHC [Ca2+]i.

Animals↗

PubMed2000

Identification and characterization of a novel gene KE04 differentially expressed by activated human dendritic cells.

To better understand the molecular mechanisms of dendritic cells (DC) function, we isolated differentially expressed genes in Ag-activated DC by a PCR-based subtractive hybridization technique. A novel full-length cDNA, KE04, was thus isolated from KLH-activated human PBMC-derived DC. KE04 cDNA encoded a 346-aa protein devoid of functionally indicative motifs. KE04 protein showed 64% identity with a Caenorhabditis elegans protein and 83% identity with a human putative protein. Distant relationship was also found with other prokaryotic and eukaryotic proteins. Differential expression of KE04 in activated DC other than nonactivated DC was confirmed at both mRNA and protein levels. KE04 mRNA expression was detectable in various human tissues and cell lines by Northern blot and RT-PCR. Western blot and confocal microscopy analysis indicated that its cytolocalization was intracellular. Our data suggest the potential involvement of KE04 in DC activation and will facilitate the research of molecular mechanism of DC function.

Amino Acid Sequence↗