PubMed Health⌕ Search

Biomedical subjects

Jun Yang

Publications and source records attributed to Jun Yang.

At least 343 records · Page 19Linked to original sources
PubMed2003

[The incidence of ischemic and hemorrhagic stroke in Chinese populations].

OBJECTIVE: To study the ratio of ischemic to hemorrhagic stroke incidence in Chinese populations. METHODS: Fifteen populations in China, each including about 100,000 residents, were monitored from 1991 to 2000 for the occurrence of stroke. Stroke was classified as hemorrhagic, ischemic and unclassified based on the clinical data and CT scan results respectively. RESULTS: The average CT scan rate in stroke patients from 1996 to 2000 varied from 14.8% to 97.5% among the 15 population and the average ratio of ischemic to hemorrhagic stroke ranged from 0.23:1 to 4.38:1; the correlation coefficient between the ratio and CT scan rate is 0.7 (P = 0.003). In all the populations with CT scan rate greater than 80%, the ischemic to haemorrhagic ratios were all greater than 1.0. From 1991 to 2000 in 12 populations with complete data, the CT scan rate in stroke patients rose from 41.1% to 88.3% and the ischemic to hemorrhagic ratio rose from 1.25:1 to 1.85:1. The correlation coefficient between the ratio and the CT scan rate was 0.9 (P < 0.001). In patients having CT scan, the ischemic to hemorrhagic ratio was greater than 1.0 in all the years. CONCLUSION: The predominant type of stroke in Chinese population is ischemic. The low CT scan rate in some populations is the main reason for the false impression predominantly hemorrhagic stroke.

Adult↗
PubMed2003

[Recombinant Helicobacter pylori urease B subunit and its biological properties].

OBJECTIVE: To perform genetic recombination of the urease B subunit (UreB) of Helicobacter pylori (Hp) and examine the biological properties of the recombinant protein. METHODS: The gene fragment encoding Hp UreB was isolated clinically from Chinese subjects by means of PCR, and cloned subsequently into an expression vector pET-11C-UreB for the non-fusion protein expression in E.coli BL21 (DE3) strain. RESULTS: The expression of recombinant UreB was achieved in E.coli BL21 with a relative molecular weight of approximately 62,000 at the expression ratio of 26%, and the first 15 amino acids of recombinant UreB were MKKISREYVSMYGP. The results of peptide mapping and amino acid compositional analysis were consistent with previous theoretical prediction, and enzyme-linked immunosorbent assay together with Western blotting indicated strong immunogenicity and reactivity of the recombinant protein in BalB/c mice, which were specifically recognized by polyclonal BalB/c mice anti-Hp sera or human sera infected with Hp. CONCLUSION: The results of this study has laid an solid immunological foundation for incorporating recombinant UreB as a subunit vaccine component against Hp.

Animals↗
PubMed2003

[Experimental study on preparing chitosan-collagen matrix and subcutaneous implantation].

OBJECTIVE: To investigate the feasibility of the chitosan-collagen membrane (CCM) as a dermal substitute. METHODS: Fresh bovine tendo calcaneus collagen was dispersed in 0.5 mol/L acetic acid, co-precipitated with chitosan and lyophilized. Dry membranes were cross-linked in 0.05% glutaraldehyde for 24 hours. In vitro its degrading rate was measured by use of collagenase degrading test. The chitosan-collagen membrane was implanted to subcutaneous dorsal sites of SD rats. After implantation, histocompatibility, vascularity and degradation were observed in vivo. RESULTS: The chitosan-collagen membrane was yellowish, translucent, and porous. Pore size ranged 50-250 microns, and collagen fiber bundles were reticular arrangement in the membrane. It had slower degradation than pure collagen membrane by collagenase in vitro. Subcutaneous implantation test showed the minimal inflammation, good histocompatibility and earlier vascularization. The membrane degradation was slower in vivo. Eight weeks after implantation, organized collagen structure was retained. CONCLUSION: The chitosan-collagen membrane has better physical and biological properties, ideal histocompatibility, earlier vascularization and slower degradation. Therefore, It is an optimum substitute for dermal scaffold.

Animals↗
PubMed2003

[Long term observation in effects of potassium and calcium supplementation on arterial blood pressure and sodium metabolism in adolescents with higher blood pressure].

OBJECTIVE: To investigate the effects of potassium and calcium supplementation in table salt on reduction of arterial blood pressure and sodium metabolism in adolescents with higher blood pressure. METHODS: A single blind placebo-controlled trial was carried out for two years in 220 adolescents with higher blood pressure, aged 18 - 22 years, who were randomly divided into supplementary group (n = 110) and control group (n = 110). Each of the subjects in the supplementary group and their family members was given 10 mmol of potassium and 10 mmol of calcium mixed in their table salt daily for 24 months. RESULTS: Night urinary sodium and potassium excretion increased (urinary Na(+), P < 0.05; urinary K(+), P < 0.01) and blood pressure lowered by 5.3 mm Hg/1.8 mm Hg in average from the baseline in the supplementary group two years after potassium and calcium supplementation, as compared with that in the control group increased by (1.3/1.7) mm Hg. CONCLUSIONS: Adequate supplement of potassium and calcium in daily table salt intake was an effective way to prevent form hypertension and could promote their urinary sodium excretion and reduction of arterial blood pressure in adolescents with higher blood pressure.

Adolescent↗
PubMed2003

[Mean level of blood pressure and rate of hypertension among people with different levels of body mass index and waist circumference].

OBJECTIVE: To assess the relationship between body mass index (BMI), waist circumference (WC) and blood pressure (BP) including hypertension. METHODS: A total of 30 003 participants aged 35 - 59 from different parts of China were surveyed for cardiovascular disease risk factors in two independent cross-sectional studies that were carried out in 1992 - 1994 and in 1998. Data were pooled to analyze the levels of BP and rates of hypertension with different levels of BMI and WC. RESULTS: The level of BP and rate of hypertension were significantly increasing with rising of WC among the majority of BMI groups (P value for trend < 0.05) and significantly increasing with rising of BMI in all WC groups (P value for trend < 0.05). The age adjusted hypertension rate with BMI < 24.0 kg/m(2) and WC < 85/80 cm (men/women), BMI < 24.0 kg/m(2) and WC >or= 85/80 cm (M/W), BMI 24.0 - 27.9 kg/m(2) and WC < 85/80 cm (M/W), BMI 24.0 - 27.9 kg/m(2) and WC >or= 85/80 cm (M/W), BMI >or= 28 kg/m(2) and WC >or= 85/80 cm (M/W) were 16.5%, 29.8%, 29.6%, 39.2% and 57.5% for men and 14.1%, 20.6%, 24.7%, 30.3% and 43.3% for women, respectively. CONCLUSION: Independent influence of BMI or WC on BP was noticed. Keeping BMI and WC at normal level might effectively prevent the occurrence of hypertension.

Adult↗
PubMed2003

Prostate cancer cells-osteoblast interaction shifts expression of growth/survival-related genes in prostate cancer and reduces expression of osteoprotegerin in osteoblasts.

PURPOSE: Prostate cancer specifically metastasizes to bone where it leads to bone formation. We previously reported that coculturing MDA PCa 2b prostate cancer cells with primary mouse osteoblasts (PMOs) induced PMO proliferation and differentiation. An osteoblastic reaction was also observed in vivo after injection of MDA PCa 2b cells into the bones of severe combined immunodeficient disease mice. The aim of this study was to identify the sequence of events that leads to these osteoblastic lesions in vivo and, using this in vitro model, to define the contributions of various genes and cellular pathways in the pathophysiology of osteoblastic bone metastases of prostate cancer. EXPERIMENTAL DESIGN AND RESULTS: We show histological evidence of de novo bone formation as early as 2 weeks after injection of MDA PCa 2b cells in the bone of severe combined immunodeficient disease mice. In vitro, we show that PMOs induce MDA PCa 2b proliferation, suggesting a synergistic paracrine loop between these cells and PMOs. Endothelin (ET)-1, which is a mitogen for several cell types, is produced by all prostate cancer cell lines tested, and Atrasentan, an antagonist of ET-1 receptor A, partially reversed PMO proliferation induced by MDA PCa 2b cells. ET-1 is known to be comitogenic with a number of growth factors, including insulin-like growth factor (IGF)-I. In this study, we report that IGF-binding protein (IGFBP)-3 transcripts (that regulate levels of free IGF) are down-regulated in prostate cancer cells cocultured with PMO, whereas prostate-specific antigen (a protease known to cleave IGFBP-3) is detected in the 150-400 ng/ml range. Accordingly, IGFBP-3 has antiproliferative effects in PMOs, which were attenuated in our in vitro system. Taken together, our studies also implicate the IGF axis to play a role in this model of bone metastases. Secondly, the transcript level of mouse double minute 2 (a protein that regulate p53) was increased in prostate cancer cells grown with PMOs. The p53-dependent and -independent oncogenic activities of mouse double minute 2 suggest that osteoblasts induce a survival advantage in prostate cancer cells. Lastly, we show that expression of osteoprotegerin is decreased and of receptor activator of nuclear factor-kappaB ligand is increased in PMOs cultured in the presence of MDA PCa 2b cells, two events associated with osteoclast activation and bone resorption. CONCLUSIONS: Our results provide evidence that multiple and distinct molecular events affecting both bone formation and bone resorption concur to the increase bone mass in prostate cancer bone metastases. These data also provide a rationale for developing therapeutic strategies designed to target these molecular changes.

Alkaline Phosphatase↗
PubMed2003

[Preparation and application of the national reference panel for hepatitis B virus DNA].

OBJECTIVES: To calibrate the national hepatitis B virus (HBV) DNA standard according to world health organization's standard material and prepare the national reference panel for HBV DNA reagents. METHODS: Sera from blood donors and HBV patients were collected and detected by home-made HBV DNA PCR kits, HBsAg kits, and anti-HBc kits, and then confirmed by HBV DNA PCR kits produced by Roche in German, which was recognized by the world health organization. The stability of the panel was detected by acceleration method. RESULTS: The convinced copies of the sensitivity samples were gotten by seven independent experiments, the coefficients of variation of logarithm of the copies of L0-L5 were all less than 15%. Regarding the national reference panel as the standard, the quality of most domestic HBV DNA PCR kits was improved, while part of the kits should be further qualified. CONCLUSION: The national reference panel for HBV DNA reagents is developed. It contains eight negative, nine positive sera and seven samples for sensitivity test

DNA, Viral↗
PubMed2003

[Effect of smoking on the periodontium and the level of aspartate aminotransferase in gingival cervical fluid].

OBJECTIVE: To study the effect of smoking on the periodontium and level of aspartate aminotransferase in gingival cervical fluid (GCF-AST). METHODS: A proportion matched case-control filtration was performed in examined population, college students, outpatients from 1999 May to 2001 March 115 smokers aged from 23 to 65 years (102 men and 13 women) and 90 non-smokers aged from 25 to 70 years (80 men and 10 women) were chosen. Debris index (DI), calculus index (CI), periodontal disease index (PDI), GCF-AST were measured. RESULTS: No obvious differences were observed in DI in smokers (0 degrees, 27.2%; 5 degrees, 5.0%) and non-smokers (0 degrees, 27.8%; 5 degrees, 4.2%),whereas obvious differences were found in CI in smokers and non-smokers. The percentages of patients without calculus were lower in smokers (9.8%) than in non-smokers (20.0%). The percentages of patients with weighty calculus were higher in smokers (25.4%) than in non-smokers (12.8%). The PDI values in smokers were higher than in non-smokers. The percentages of their normal periodontium were lower in smokers (9.6%) than in non-smokers (20.8%). The percentages of their periodontitis were higher in smokers (38.5%) than in non-smokers (25.8%). The smoking quantity were positively related to periodontitis (P < 0.001). No obvious differences were found in the level of GCF-AST with same PDI (P > 0.05). CONCLUSION: Smoking is considered as one of the risk factors in the prevalence of periodontal disease, but may not have any direct effect on GCF-AST.

Adult↗
PubMed2003

[The emission of rare earth complex Eu(asprin)3phen].

Two kinds of electroluminescent devices were fabricated by doping the rare earth complex Eu(asprin)3phen into polymer PVK: (1) ITO/PVK:RE/LiF/Al; (2) ITO/PVK:RE/PBD/LiF/Al. A great difference in the EL spectrum was found between the two kinds of devices. In device (2) the intensity of 594 nm was rather weak compared with that of 614 nm. The spectrum was consistent with the photoluminescence (PL) spectrum under the state of thin film. But in device (1), the peak emission of 594 nm was comparable to that of 614 nm. Preliminary discuss on this phenomenon was made; in device (1), the recombination region was close to the metal cathode, effect of metal cathode on the electroluminescence of the rare earth complex caused the changes of the EL emission which was quite different from the TL emission. The phenomenon was not observed in device (2) whose recombination region was far from the cathode because an electron-transport layer was inserted.

Chelating Agents↗
PubMed2003

[Advance in signal analysis of auditory evoked potential].

Signal analysis of the auditory evoked potential (AEP) has been the interesting field in biomedicine and signal processing for a long time. Recent advances in the analytic method of AEP are summed up in this paper. Seven methods, including spectral analysis, adaptive filtering, wavelet transform, chaos theory, artificial neutral network, regularization, and independent component analysis are mainly introduced. All of them are promising for extracting the signal with less stimulation and adequate quality, and for displaying their efficient application in the analysis of AEP.

Electroencephalography↗
PubMed2003

[The effect of nuclear transcription factor-kappaB decoy oligodeoxynucleotides on the intimal hyperplasia in vein graft].

OBJECTIVE: To investigate the effect of nuclear transcription factor-kappaB decoy oligodeoxynucleotides (NFkappaB decoyODNs) on the intimal hyperplasia (IH) in vein graft in rats. METHODS: Autogenous vein graft model for 72 Wistar rats was established, and the interior jugular vein was transplanted to common jugular artery by microsurgical technique. The rats were divided into 6 groups according to different processing methods, including NFkappaB decoyODNs 50 microg and 200 microg, scramble decoyODNs 50 microg and 200 microg, control and lipofectin + pluronic teams. Vein graft samples were harvested in 1 or 2 weeks after surgery and ICAM-1 mRNA were measured by RT-PCR. Western blotting and immunohistochemistry methods were also employed to detect the expression of p65 and ICAM-1. IH was compared at the same time. RESULTS: The intimal hyperplasia was evident in 1 or 2 weeks after vein graft, and ameliorated by 50 microg of NFkappaB decoyODNs with inhibition rate from 22% to 31%, 200 microg of NFkappaB decoyODNs had a higher inhibition rate from 41% to 53%. However, no effect was found in the other teams. The expression of ICAM-1 mRNA was also inhibited significantly by NFkappaB decoyODNs and more obvious in 2 weeks after surgery. Expression of ICAM-1 and p65 decreased greatly in NFkappaB decoyODNs team, which has a inhibition rate from 30% to 57%. CONCLUSION: Transfection of NFkappaB decoyODNs can inhibit the IH after vein graft, which may be accomplished by the inhibition of gene expression of ICAM-1.

Animals↗
PubMed2003

[Relation of body mass index and waist circumference with clustering of other risk factors for cardiovascular disease].

OBJECTIVE: To assess the relationship of body mass index (BMI) and waist circumference (WC) with clustering of other risk factors for cardiovascular disease (CVD). METHODS: A total of 30 561 participants aged 35 - 59 from different parts of China were surveyed for risk factors of CVD in two independent cross-sectional studies carried out in 1992 - 1994 and 1998. Data were pooled to analyze clustering rate of risk factors for CVD and relative risk of their clustering at varied levels of BMI and WC. Clustering of other risk factors for CVD was defined as any participant who had any two or more risk factors, such as high blood pressure, high serum total cholesterol, low HDL-C, high fasting plasma glucose. Clustering rate of other risk factors for CVD at different levels of BMI and WC was estimated. RESULTS: Clustering rate of other risk factors for CVD significantly increased with rising of BMI and WC. In most of varied BMI groups, clustering rate of other risk factor increased with rise of WC in both men and women (P value for trend < 0.05), and in most of varied WC groups, clustering rate of other risk factor significantly increased with rise of BMI (P value for trend < 0.05). Clustering rate of other risk factors for CVD adjusted for age was 11.1% and 10.4% with BMI < 24.0 kg/m(2) and WC < 85/80 cm, 24.0% and 17.0% with BMI of 24 - 27.9 kg/m(2) and WC < 85/80 cm, 34.3% and 24.0% with BMI of 24 - 27.9 kg/m(2) and WC of 85 - 95.9/80 - 89.9 cm, 40.8% and 29.6% with BMI of 24 - 27.9 kg/m(2) and WC >/= 95/90 cm, 44.2% and 29.9% with BMI >/= 28 kg/m(2) and WC of 85 - 95.9/80 - 89.9 cm, and 54.7% and 35.4% with BMI >/= 28 kg/m(2) and WC >/= 95/90 cm, for men and women, respectively. CONCLUSIONS: BMI and WC were independently and positively associated with clustering rate of other risk factors for CVD. It is very important for health to keep both BMI and WC in normal level.

Body Constitution↗
PubMed2003

[Novobiocin inhibits angiogenesis and shows synergistic effect with vincristine].

AIM: To study the anti-angiogenic activity of novobiocin and its mechanism of action. METHODS: The anti-angiogenic activity of novobiocin was determined using chick embryo chorioallantoic membrane(CAM) assay. MTT assay, zymography and related assays were used to observe the effects of drugs on bovine aorta endothelial cells and human pulmonary carcinoma PG cells. RESULTS: Novobiocin at the doses of 100 and 200 micrograms/egg inhibited angiogenesis by 31.6% and 68.7% in CAM, respectively. The combination of novobiocin and vincristine enhanced the anti-angiogenic effect. Novobiocin inhibited the proliferation of bovine aortic endothelial cells in a concentration-dependent manner. In addition, novobiocin suppressed MMP-2 secretion, migration, and tube formation of endothelial cells. As determined by MTT assay, novobiocin in combination with vincristine displayed synergistic effect on the proliferation of PG cells, CONCLUSION: This study demonstrates that novobiocin is active in suppressing angiogenesis and the anti-angiogenic activity may be enhanced by combination with vincristine. The anti-angiogenic activity of novobiocin may be related, at least in part, to its inhibition of cell proliferation, cell migration, tube formation and secretion of matrix metalloproteinases.

Angiogenesis Inhibitors↗
PubMed2003

[Development of a gap ligase chain reaction for detection of Chlamydia trachomatis in newborn infants].

OBJECTIVE: To establish a gap ligase chain reaction (G-LCR) assay for the detection of Chlamydia trachomatis (Ct) in neonates with pneumonia. METHODS: A G-LCR DNA amplification assay that targeted the outer major membrane protein gene (omp1) of Ct was developed to detect Ct. The sensitivity and specificity of the G-LCR test was examined by the use of highly purified elementary bodies (EBs). Nasopharyngeal swabs taken from 328 neonates with pneumonia were analyzed by Gap-LCR and cell culture. RESULTS: The detection limit of G-LCR was 2 EBs. G-LCR could detect five species of Ct and was not cross-reacted with C psittaci and other bacteria. The prevalence of Ct in 328 neonates with pneumonia, using an expanded gold standard of a positive cell culture or two confirmed positive non-culture tests, was 21% (69/328). After analysis of discrepant results, the sensitivity, specificity, and positive and negative predictive values for the G-LCR were 98.6%, 100%, 100% and 99.6%, respectively; whereas those for culture were 86.9%, 100%, 100% and 96.6%, respectively. CONCLUSION: This study demonstrated that the G-LCR was a highly sensitive nonculture technique and good alternative test for the detection of chlamydial infections.

Chlamydia Infections↗
PubMed2003

[The correlation between Kawasaki disease and polymorphisms of Tumor necrosis factor alpha and interleukin-10 gene promoter].

OBJECTIVE: Kawasaki disease (KD) is an acute febrile vasculitic syndrome of unknown etiology that preferentially affects coronary artery. It has been suggested that proinflammatory cytokines like tumor necrosis factor alpha (TNF-alpha) and interleukin-10 (IL-10) are key players during acute KD. Recently, the polymorphisms relative to major transcriptional start site of TNF-alpha and IL-10 gene were shown to influence the level of TNF-alpha and IL-10 production in vitro. This study was aimed to investigate the genetic association of TNF-alpha and IL-10 promoter polymorphisms in juvenile patients of Han nationality with KD, and to investigate the possible associations with clinical manifestations of the disease. METHODS: Four polymorphism sites of TNF-alpha and IL-10 gene promoter regions from 96 children with KD were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). One hundred and sixty age-matched normal children of the Han nationality were used as control. All patients accepted Doppler echocardiography examination in order to differentiate coronary artery lesions. RESULTS: There was significant difference in allele frequencies of -308 (A/G) site of the TNF-alpha gene between children of the Han nationality and those of Japanese and Caucasian in America. There were significant differences in the allele frequencies of -1082 (G/A), -819 (C/T) and -592 (A/C) of IL-10 gene between children of the Han nationality and their British Counterparts (P < 0.01). There was no significant difference in allele frequencies of -308 (A/G) site of TNF-alpha gene between children with KD and normal controls. There was no significant difference in the haplotypes and the allele frequencies of the above three sites of IL-10 between the two groups. However, when clinical features were examined, the genotype frequency of TNF-alpha-308A was significantly higher in IVIG-resistant KD patients than that of TNF-alpha-308G genotype (67% vs 5%, chi(c)(2) = 90.48, P < 0.01). The genotype of TNF-alpha-308A was closely associated with IVIG-resistant KD (P < 0.01, relative risk 42.25, 95% confidence interval 15.81-112.88). The haplotype frequency of IL-10 -1082A/-819T/-592A was also higher in patients with coronary artery lesion (CAL) caused by KD than those of Non-ATA haplotype (52% vs 20%, chi(2) = 18.36, P < 0.01). The haplotypes of IL-10 -1082A/-819T/-592A was significantly associated with CAL caused by KD (P < 0.01, relative risk 4.26, 95% confidence interval 2.20-8.25). CONCLUSION: The genotype of TNF-alpha-308A is one of the important factors that probably influence the therapeutic effect of KD. The haplotypes (-1082/-819/-592) of IL-10 gene promoter might be related to the pathogenesis of coronary artery complication of KD and -1082A/-819T/-592A haplotypes might be regarded as a genetic marker of risk factor for coronary artery lesion in KD.

Child↗
PubMed2003

[Effects of yi-fu-ning soft capsule on sex hormone, NO, NOS, SOD and MDA levels in ovariectomized rat serum].

OBJECTIVE: Through investigating the changs of sex hormone, nitric oxide (NO), nitric oxide synthase (NOS), superoxide dismutase (SOD) and malonaldehyde (MDA) in the serum of ovariectomized, rats, the mechanism of cardiovascular disease occurring in post-menopause rats and the effect of Yi-Fu-Ning soft capsule (YFN) on above-menticned indexes were discussed. METHOD: Fifty female mature Sprague-Dawley rats were randomly divided into 5 groups: sham operation, ovariectomy (OVX), OVX with diethylstilbestrol tables (DT), OVX with YFN (high dose and low dose). After administrating drugs of 4 weeks, sex hormone, NO, NOS, SOD and MDA levels in rat serum were detected. RESULT: In ovariectomized rats serum, with the drop of E2 concentration, NO, NOS, SOD levels decreased, while MDA content increased. And the E2 concentration was correlated with other index levels. YFN can obviously regulate above-mentioned indexes. CONCLUSION: The cardiovascular disease occurring in post-menopause rats is possibly due to the decrease of serum sex hormone, which cause the disease through the loss of the NO and damage of the free radical. YFN can prevent and cure the cardiovascular disease by regulating above-mentioned indexes in post-menopause rats.

Animals↗