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Biomedical subjects

X Liu

Publications and source records attributed to X Liu.

At least 613 records · Page 34Linked to original sources
PubMed2000

Deployment and the probability of spousal aggression by U.S. Army soldiers.

OBJECTIVE: To determine the relationship between length of soldier deployment and self-reports of moderate and severe spousal violence. METHODS: The Conflict Tactics Scale was used to measure self-reports of behaviors exhibited in marital conflict. Surveys were administered to a 15% random sample of 26,835 deployed and nondeployed married active duty U.S. Army men and women in the 50 United States during the period 1990 to 1994. Multinomial logistic regression and ordered probit analysis were used to estimate the probabilities of moderate and severe violence by length of deployment. RESULTS: After controlling for demographic variables, the probability of severe aggression was significantly greater for soldiers who had deployed in the past year compared with soldiers who had not deployed. CONCLUSIONS: Deployment contributes a significant but small increase to the probability of self-reported spousal aggression during a 1-year period. Although deployment is a military operation, similar effects may be observed in certain civilian occupations.

Adult↗
PubMed2000

Behavioral and emotional problems in Chinese children: teacher reports for ages 6 to 11.

This study examined the applicability of the Chinese Version of Teacher's Report Form (TRF-CV) and estimated the prevalence of behavioral problems in a general population sample of 2,936 children aged 6 through 11 years in the Shandong Province of China. Teachers completed the TRF-CV and the Conners Hyperkinesis Index (CHI). The TRF-CV total scale showed satisfactory 2-week test-retest reliability (r = .83) and internal consistency (Cronbach's alpha = .94). The TRF-CV Total Problems, Attention Problems, Delinquent Behavior, and Aggressive Behavior had acceptable concurrent validity with the CHI (mean r = .62). With the TRF-CV Total Problems score of 26 as a cutoff, an overall correct classification rate of 90% for clinical sample and nonreferral required children was obtained. Exploratory factor analysis yielded six syndromes: Aggressive/Delinquent Behavior, Withdrawn/Depressed, Somatic Complaints, Attention Problems, Social Problems, and Thought Problems, with significant correlations with corresponding American cross-informant syndromes (mean r = .84). The overall prevalence rate of behavioral problems was 15.5% (95% CI = 14.2-16.8%), with a boy-to-girl ratio of 2.0:1 (chi2 = 59.70, p < .001). Younger boys exhibited more externalizing problems. These findings indicate that the TRF-CV is applicable for Chinese children, and the prevalence of behavioral problems shown by it among Chinese children seems comparable to that found in other countries. Although most of the American syndromes were well replicated, the differences in the present subjects, when submitted to principal components analysis, from American samples from whom the original syndromes were derived, could have prevented the study from replicating distinctions between aggressive vs. delinquent and depressed vs. withdrawn syndromes.

Affect↗
PubMed2000

[Genetic polymorphism of 5 STR loci on chromosome 14 in Chinese Han].

OBJECTIVE: To understand the distribution of genes and genotypes of 5 STR loci on chromosome 14 in Chinese Han. METHODS: PCR and polyacrylamide gel electrophoresis were used to analyze the polymorphism of 5 STR loci (D14S742, D14S306, D14S606, D14S617, D14S611) on chromosome 14 in Chinese Han. RESULTS: 5 alleles and 13 genotypes, 5 alleles and 13 genotypes, 6 alleles and 13 genotypes, 9 alleles and 21 genotypes, and 6 alleles and 13 genotypes were observed at D14S742, D14S306, D14S606, D14S617 and D14S611, respectively. The frequencies of the most common allele at these five loci were 0.31, 0.31, 0.47, 0.35 and 0.29 respectively. CONCLUSION: These five loci are highly polymorphic in Chinese Han and their allele distribution is in good agreement with Hardy-Weinberg equilibrium.

China↗
PubMed2000

Genetic polymorphism of 4 STR loci on chromosome 17 in Chinese Han.

OBJECTIVE: To analyze genetic polymorphism of D17S1290, D17S1293, D17S1303 and D17S1308 in Chinese Hans. METHODS: Fifty unrelated individuals were analyzed by PCR amplification fragment length polymorphism analysis method. RESULTS: 9, 7, 5, 5 alleles were observed at these 4 STR loci respectively, the genotypes distributions in Chinese Hans were in accordance with Hardy-Weinberg equilibrium, the expected heterozygosities for these loci were 0.770, 0.828, 0.608, 0.669 respectively, the polymorphism information contents(PIC) were 0.763, 0.820, 0.602, 0.662 respectively. CONCLUSION: The results demonstrate these 4 STR loci can be used for genetic analysis.

China↗
PubMed2000

[A self-adaptable system for acquiring and processing animal ECG parameters].

The present authors have developed a computerized system for acquiring and processing the animal ECG. The system provides many functions in the software design and the users can compile the parameter-analyzing formulae by themselves according to the characteristics of ECG. The system is much more accurate and flexible in analyzing the ECG parameters and can significantly avoid the processing mistakes caused by signal variations and interference. It is especially suitable for continuous ECG monitoring and analysis of animal experiments in physiology, pharmacology and toxicology.

Animals↗
PubMed2000

Spouse abuse recidivism in the U.S. Army by gender and military status.

Recidivism by spouse abusers was investigated using records of offenders in the U.S. Army Central Registry. Recidivism by gender and military status (active-duty or civilian spouse) was compared over a 70-month period. Between fiscal years 1989-1997, 48,330 offenders were identified in initial and recidivist incidents. Recidivism was analyzed by means of a Cox proportional hazard rate model, controlling for age, race, number of dependents, education, and substance abuse. Two different sets of survival curves were obtained: (a) Men were much more likely than women to have a recurrence and (b) within gender, civilians were more likely to have a recurrence than were active-duty military personnel. At 70 months, 30% of the male civilian offenders and 27% of the male active-duty offenders had committed a subsequent spouse abuse incident compared with 20% of the female civilian offenders and 18% of the female active-duty offenders, controlling for other variables.

Adult↗
PubMed2000

Pattern recognition of genomic features with microarrays: site typing of Mycobacterium tuberculosis strains.

Mycobacterium tuberculosis (M. tb.) strains differ in the number and locations of a transposon-like insertion sequence known as IS6110. Accurate detection of this sequence can be used as a fingerprint for individual strains, but can be difficult because of noisy data. In this paper, we propose a non-parametric discriminant analysis method for predicting the locations of the IS6110 sequence from microarray data. Polymerase chain reaction extension products generated from primers specific for the insertion sequence are hybridized to a microarray containing targets corresponding to each open reading frame in M. tb. To test for insertion sites, we use microarray intensity values extracted from small windows of contiguous open reading frames. Rank-transformation of spot intensities and first-order differences in local windows provide enough information to reliably determine the presence of an insertion sequence. The nonparametric approach outperforms all other methods tested in this study.

Genome, Bacterial↗
PubMed2000

Variation in managing asthma: experience at the medical group level in California.

OBJECTIVE: To explore the degree of variation in the quality of asthma management among physician groups participating in a managed care network. STUDY DESIGN: Cross-sectional observation. PATIENTS AND METHODS: The study population consisted of patients with moderate or severe asthma identified through a pharmacy database from a managed care plan in 1996. The patients were surveyed to obtain their assessments of asthma care, including components on quality of care, quality of service, and outcomes of care. We selected 47 physician groups that provided services for at least 35 asthma patients who responded to the survey. Variations in the outcome variables across physician groups were described by quartile, range, and histogram. RESULTS: Compliance with national guidelines varied among physician groups but was generally low. Physician group rates for patient use of steroid inhalers ranged from 10.7% to 45.5% and daily peak flow meter use ranged from 0% to 13.1%. Satisfaction ratings were higher, with overall satisfaction with the quality of asthma care ranging from 74.6% to 94.3%. Outcomes also showed considerable variation among groups. One-month absenteeism rates ranged from 32% to 61%, and 65.7% to 94.3% of respondents did not have an emergency room visit in the past year. CONCLUSION: The quality of asthma care and service varied significantly across physician groups. Such reports for different physician groups make evidence-based outcomes information directly available to patients and physician groups, help patients make informed healthcare decisions, and stimulate quality improvement efforts by physician groups.

Adolescent↗
PubMed2000

Functional analyses of patient-derived IgG monoclonal anticardiolipin antibodies using in vivo thrombosis and in vivo microcirculation models.

Antiphospholipid antibodies (aPL) have been associated with thrombosis and pregnancy losses in patients diagnosed with antiphospholipid syndrome (APS) and enhance thrombus formation in vivo in mice, but the mechanism of thrombosis by aPL is not completely understood. It has been proposed that aPL may affect endothelial cell (EC) function and/or induce their activation, transforming their anticoagulant surface into procoagulant, thus predisposing to thrombosis. It has been proposed that aPL may affect EC cell function and/or induce their activation, transforming their anticoagulant surface into procoagulant, thus predisposing to thrombosis. This study proposes to test the hypotheses that some IgG anticardiolipins (IgG aCL) with thrombogenic properties in mice, exert their effects through activation of endothelium. We studied seven patient-derived monoclonal aCL for their thrombogenic properties in an in vivo pinch-induced thrombosis model, and their functional activities in activating EC by analyzing in vivo leukocyte adhesion to endothelium in microcirculation in venules in exposed murine cremaster muscle and in vitro adhesion molecule expression in cultured EC. The binding of the monoclonal aCL to EC was also tested. In addition to the previous identified thrombogenic IS2, four of the five new more IgG monoclonal aCL (from two patients) were found to be thrombogenic. Of these five thrombogenic aCL, three caused more in vivo leukocyte adhesion to EC in microcirculation, as compared to that induced by the H2 control human monoclonal IgG, and enhanced expression of adhesion molecules (particularly VCAM-1) on cultured EC. These data show that about 2/3 patient-derived IgG monoclonal aCL are thrombogenic and suggest that some thrombogenic IgG aCL exert their effects through activating EC.

Adult↗
PubMed2000

Progress in the molecular genetic research of multinodular goiter.

Multinodular goiter is a worldwide-distributed disease, but yet its pathology and genetic etiology are not clear. At present, most researches have been restrained to traditional epidemiological survey and the disease has been rarely studied at the level of molecular genetics. The pathogenesis of multinodular goiter, as is generally accepted by most researchers, can be attributed to many factors such as hormones, growth factors and the inherent functional heterogeneity of thyroid follicles. Since hormone and iodine metabolization are widely recognized as a major mechanism in determining the formation of multinodular goiter, some reports in literature are mainly focused on such genes that are responsible for hormone synthesis and iodine metabolization. Mapping experimental data were available to support location of multinodular goiter gene(s) onto chromosome 14q by whole genome scanning in a large pedigree analysis. Additional data, particularly those extracted from large scaled marker-assisted mapping experiments, are important so as to confirm the gene location, to improve resolution of the location, and finally to dissect the genes underlying the disease at molecular level.

Chromosome Mapping↗
PubMed2000

[Regulation of transcription factors c-myb and liver activator protein on expression of alpha1(I) collagen gene in activated hepatic stellate cells].

OBJECTIVE: To elucidate the role of two transcription factors, c-myb and liver activator protein (LAP, a member of the C/EBP family) in the expression of alpha1(I) collagen gene in activated hepatic stellate cells (HSCs). METHODS: Rat HSCs were prepared from SD rats by in situ perfusion and single-step density Nycodenz gradient. Two chimeric luciferase reporter gene plasmids containing the human collagen alpha1(I) gene promoter fragments (-804 approximately +1452 or -804 approximately +222) were constructed. Culture-activated HSCs were co-transfected with the reporter gene constructs and mammalian vectors expressing c-myb or/and LAP using the cationic-liposome mediated method. RESULTS: Transient transfection of the vector expressing LAP significantly increased basal transcription from PGL(3)-col and PGL(3)-col (intron) reporter gene vectors [(587 +/- 62)U/mg protein vs (315 +/- 45)U/mg protein and (326 +/- 52)U vs (220 +/- 70)U, t=10.4 and 3.6, respectively, both P<0.05]. C-myb showed no transactivation to both PGL(3)-col and PGL(3)-col (intron) reporter gene vectors. But co-expression of LAP and c-myb increased basal transcription from PGL(3)-col reporter gene by approximate 3 fold (1261 +/- 130)U vs (315 +/- 45)U, t=20.6, P<0.01. Moreover, co-expression of a specific c-myb antisense vector with the LAP vector inhibited the transactivation of LAP to collagen alpha1(I) gene promoter activity (334 +/- 29)U vs (315 +/- 45)U, t=1.06, P>0.05), which was observed only in PGL(3)-col plasmids. CONCLUSION: The transcription factor LAP transactivates collagen alpha1(I) gene in activated HSCs. C-myb plays an important role in transcriptional regulation of alpha1(I) collagen gene in HSCs and this effect is mediated by the transcription factor LAP and the cis-acting element in the first intron of alpha1(I) collagen gene.

Animals↗
PubMed2000

[Progress in the studies on the molecular genetics of schizophrenia].

Although population genetic studies have long confirmed the genetic vulnerability of schizophrenia,ongoing advances in molecular genetic technology and biostatistic analysis are only now making it possible to search for the susceptibility gene of the disease. This article reviewed some of the recent findings in this area: (1) The heritability of schizophrenia is estimated around 60%-80%. The phenotype differentiation is based on standard diagnostic scales and symptom rating scales. (2) The two main approaches to finding the genes that influence the disorder are now genomic scan and candidate gene detection. Affected sib-pair (ASP) method and transmission disequilibrium test(TDT) are considered promising analyses. (3) The positive candidate regions with some independent replicable reports concentrated on 6p, 22q and 8p. Positive findings of candidate gene research involved 5-HT2A receptor, DRD3, NT-3, etc. Further directions to identify the susceptibility genes include: Applying more precise instruments to define clinical phenotype of the disease. Application of proper biological markers such as electrophysiologic parameters and brain imaging will be a prospective approach. Using larger sample to increase statistic power and developing more powerful statistic analysis, and performing advanced molecular genetic technique such as DNA pooling, DNA chips, genomic mismatch scanning (GMS), representational difference analysis(RDA), comparative genomic hybridization(CGH) and two-dimensional DNA typing methods will also facilitate this research area to greater perspective.

Chromosome Aberrations↗
PubMed2000

[Study of the correlation between in vitro and in vivo evaluation methods on biomaterials--DNA test and muscular implant test].

With the wide-spread use of biomaterials, the safety evaluation on biomaterials has become a very important step. This study on the correlation between DNA test and muscular implant test was done for finding out good in vitro evaluation method. The tissue toxicities of seven biomaterials were examined. Good correlation between DNA test and muscular implant test was demonstrated by Spearman sequential correlation analysis.

Animals↗
PubMed2000

[E-cadherin expression and its clinical significance in cervical cancer].

OBJECTIVE: To study the clinical significance of E-cadherin (E-CD) expression in cervical cancer. METHODS: Specimens of 60 cervical cancer, 10 normal cervical epithelia and 12 cervical intraepithelial neoplasia(CIN) were examined for E-CD expression by immunohistochemical staining. RESULTS: E-CD was expressed in all of 10 specimens of normal cervical epithelia. Positive staining was seen in 66.7% of CIN, 46.7% of cervical cancer. In cervical cancer, the frequency of abnormal E-CD expression was correlated to pathologic grade, lymph node metastasis and clinical stage (P < 0.05). The higher the pathologic grade of tumor, the lower was the expression of E-CD. Negative E-CD expression was significantly more frequent in the advanced stage of cervical cancer with lymph node metastasis. CONCLUSION: Decreased expression of E-CD is a useful parameter of cervical malignancy.

Adult↗
PubMed2000

Basic fibroblast growth factor up-regulates the expression of vascular endothelial growth factor in primary cultured rat astrocytes.

AIM: To examine the effect of recombinant human basic fibroblast growth factor (bFGF) on the expression of vascular endothelial growth factor (VEGF) in primary cultured rat astrocytes. METHODS: Semiquantification PCR (SQ-PCR) and immunocytochemistry were used to investigate the effect of bFGF on VEGF mRNA level and protein level, respectively. RESULTS: Treatment with bFGF dose-dependently increased the VEGF mRNA level in astrocytes. The up-regulation of VEGF mRNA induced by bFGF (10 micrograms/L) was detected as short as 3-h treatment. The increase of VEGF mRNA level reached the maximum after 24-h treatment with bFGF. The immunocytochemical staining showed that the VEGF protein level in astrocytes also increased after the cells were incubated with bFGF. CONCLUSION: bFGF induced a marked time- and concentration-dependent increase in VEGF expression in primary cultured astrocytes, suggesting that the effect of bFGF on angiogenesis in brain may act partly by up-regulating VEGF expression in astrocytes.

Animals↗
PubMed2000

Evaluation of therapeutic effect of maneuver-dominated method in 30 cases of cervical spondylotic myelopathy.

Thirty cases of cervical spondylotic myelopathy (CSM) were treated by a maneuver-dominated non-surgical therapy. Eighteen cases were recovered to grade E according to the criteria set by the American Spinal Injury Association. The effect was definite. Indications and contraindications of the maneuver were proposed on the basis of the pathogenesis of CSM and the principles of this manual method.

Adult↗
PubMed2000

[The study on biologic manner and clinical management of intravenous uterine leiomyoma].

OBJECTIVE: To investigate the biologic manner of intravenous uterine myoma and the clinical management. METHODS: Analysed 11 cases of intravenous leiomyoma retrospectively from 1994 to 1998, of which all specimens of intravenous leiomyoma were confirmed by pathologic examination. The estrogen receptor was measured by immunohistochemistry. RESULTS: Nine patients (81.8%) presented menorrhagia, two patients (18.2%) appeared anemia. The size of uterus more than three pregnancy months was seen in seven cases (63.6%), of which six patients (6/7) showed uterine multiple nodule and abundant blood flow by ultrasound compared with those whose uterine size smaller than three pregnancy months (P > 0.05). The correct diagnosis before operation was 0 percent, 63.6% of the patients was diagnosed during operation (P < 0.05). Seven patients (63.6%) had classical pathological appearance of intravenous leiomyoma. Positive estrogen receptors were detected in six patients. One patient (9.1%) was recurred. CONCLUSIONS: Uterine intravenous leiomyoma has typical clinical and pathologic feature. The adverse biologic manner and the clinical treatment are related to prognosis.

Adult↗