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Biomedical subjects

Jun Yang

Publications and source records attributed to Jun Yang.

At least 415 records · Page 23Linked to original sources
PubMed2002

[Inter-population and inter-individual effect of education attainment on men's behavior of smoking: China multi-center study of cardiovascular epidemiology].

OBJECTIVE: To study the inter-population and inter-individual effect of education attainment on men's behavior of smoking in China. METHOD: A cross-sectional study of 7,415 men, aged 35-59 years, from 15 population samples was carried out in 1998. Information on education attainment and smoking was collected by standardized questionnaires. The population samples were divided into 2 groups according to the proportion of men with college or above education attainment: group I had an average 25.8% of men with college or above education attainment, and group II had an average 2.0% of men with college or above education attainment. RESULTS: (1) In group I, the percent of ever smokers, current smokers, deeper smoker, and ever smokers with cessation due to disease and the average number of cigarettes per day for the smokers were significantly lower than in group II (66.2%, 56.4%, 34.4%, 47.8%, 17.2 cigarettes/day vs 75.8%, 64.4%, 40.3%, 58.4%, 20.4 cigarettes/day, respectively). (2) The percent of current smokers and the number of cigarettes decreased with increased education attainment in both groups. Taking the men with college or above education attainment in group I as reference, the odd ratio of smoking for those with high school education in group I was 1.8 (95% CI: 1.5-2.1), for those with middle school or lower education in group I was 2.0(95% CI: 1.7-2.5), for those with college or above education in group II was 1.4(95% CI: 0.9-2.1), for those with high school education in group II was 1.7(95% CI: 1.4-2.1), and for those with middle school or lower education in group II was 2.4 (95% CI: 2.1-2.8). CONCLUSION: Smoking behavior was affected by both individual education attainment and population education level. Smoking cessation measures should be focused on the development of better anti-smoking environment, such as education development, health promotion, etc.

Adult↗
PubMed2002

[Synthesis and spectroscopic characterization of complexes of trivalent lanthanide ions Eu(III) and Tb(III)].

Two coordination compounds formed between Eu(III) and Tb(III) with ofloxacin have been synthesized. Molecular formula Ln(oflo)3Cl3.8H2O has been deduced from elemental chemical analysis and ICP.FTIR spectroscopy shows that both carbonyl and carboxy groups may coordinate the lanthanide cation(Eu3+/Tb3+) to form a stable six-membered ring. The reaction between lanthanide and ofloxacin can be accomplished without any additional base since FTIR suggests the proton transportation from the carboxyl group to the tertiary nitrogen. The complex containing Eu3+ was proved to be excited with the broad band from 200 to 450 nm. Between the two complexes is studied, Eu3+ is the most efficiently sensitized by ofloxacin, while Tb3+ is the least. The disappearance of the ligand fluorescence and the strong emitting of Eu3+ in the complex, which is ascribed to the transitions 5D0-7F0, 5D0-7F1, 5D0-7F2 respectively, make it clear that some well energy transfer has happened. But complex Tb(oflo)3Cl3.8H2O irradiates lights from both ligand and Tb3+.

Anti-Infective Agents↗
PubMed2002

Enhancement patterns of small hepatocellular carcinoma shown by dynamic MRI and CT.

OBJECTIVES: To study prospectively the enhancement features of small hepatocellular carcinoma (SHCC) with multi-phase scanning of dynamic MRI and spiral CT, and discuss the superiority of dynamic MRI to spiral CT. METHODS: Multi-phase dynamic contrast scanning of high field MRI and spiral CT were performed in 53 patients with SHCC. The arterial phase, portal venous phase and delayed phase scanning of spiral CT was done after the pre-contrast scanning of the entire liver. MRI was performed with SE sequence and fast multiplanar spoiled gradient-recalled sequence dynamic multi-phase contrast scanning. RESULTS: Seventy-six lesions were found in all 53 patients. Sixty-nine and 54 of the 76 lesions enhanced obviously in MRI and spiral CT arterial phase scanning respectively. The typical enhancement patterns of SHCC in the arterial phase, portal venous phase and delayed phase scanning of MRI and spiral CT were hyper-hypo-hypointense (dense) and hyper-iso-hypointense (dense). Atypical enhancement patterns were hyper-hyper-hyperintense (dense), hyper-iso-isointense (dense) and hypo-hypo-hypointense (dense). CONCLUSIONS: Both MRI and spiral CT multi-phase dynamic contrast-enhanced scanning could demonstrate the enhancement features of SHCC, and arterial phase scan of MRI was superior to spiral CT in reflecting the hypervascular characterization of SHCC. In addition, MRI was better than spiral CT in characterization of hepatic lesions combined with SE sequence.

Adult↗
PubMed2002

[Percutaneous visceral tumor puncture director].

A percutaneous visceral tumor puncture director is introduced in this paper, which can be used for needle biopsy and brush biopsy in kinds of visceral tumor. The clinical informations show that the application of the director can increase the positive ratio of puncture, and it has important clinical value. The director is safe, practical and easy to operate.

Biopsy, Needle↗
PubMed2001

Dendron-Controlled Nucleation and Growth of Gold Nanoparticles We thank the University of Arizona and the Research Corporation for financial support. Acknowledgement is also made to the donors of the Petroleum Research Fund, administered by the American Chemical Society, for partial support of this research. The X-ray diffractometer was purchased with support from the U.S. National Science Foundation (CHEM-9610374). We thank Dr. K. Nebesny for help with the XPS experiments.

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Journal Article↗
PubMed1999

Group II Phospholipase A(2) Activity and Its Molecular Regulation in Rat Heart during Sepsis.

Changes of activity and content of myocardial group II phospholipase A(2) and its mRNA transcription and stability during rat sepsis were investigated. Results showed that, compared with control group,myocardial group II phospholipase A(2) activity in early and late sepsis decreased by 25.0%(P<0.05) and increased by 47.6%(P<0.01),respectively group II phospholipase A(2) protein concentration reduced by 27.0% and augmented by 48.0%(P<0.01),respectively. Myocardial group II phospholipase A(2) mRNA transcription rate and content showed similar two-phases changes. The mRNA transcription rate during early and late sepsis decreased by 45.0% and increased by 70.0%(P<0.01),respectively. The mRNA content decreased by 34.1% in early sepsis and increased by 157.0% in late sepsis(P<0.01), respectively. The half-life of group II phospholipase A(2) mRNA remained unchanged notably during early and late stage of sepsis. These data suggest that myocardial group II phospholipase A(2) activity decreased in early stage of sepsis and increased in its late stage, and these changes were regulated transcriptionally.

Journal Article↗
PubMed1997

Analysis of Activation Activity of Yeast PHO2, PHO4 Protein and Their Interaction.

Both PHO2 and PHO4 are positive regulatory factors of yeast PHO5 gene. Here we show that the PHO2 fused to yeast transcriptional factor GAL4 DNA-binding domain activates the expression of the reporter gene (lacZ), and the lacZ activities were regulated by Pi concentration, therefore it could be suggested that there are acidic activation domains on the PHO2 protein. Acidic amino acid rich region of 287-326 aa in PHO2 is not a transcriptional activation domain. PHO2 maintained its activation activity only if Ser230 is phosphorylated, thus the phosphorylated site may play a key role in the transcriptional activation function of PHO2. PHO4 fused to the GAL4 DNA-binding domain also activates the expression of lacZ. A segment of 1-97 aa at its N-terminal is responsible for the transcriptional activation activity. A two-hybrid assay reveals that there exists interaction between PHO2 and PHO4 protein, and the interaction affects their transcriptional activation function.

Journal Article↗
PubMed1996

The Effect of Yeast Transcriptional Factor PHO2 on the Gene Expression of PHO5, HIS4 and HO.

Yeast PHO2 protein plays a role in the expression of several different genes and acts as a multiple global activator. Here we report the comparison of the effect of PHO2 protein on the expression of PHO5, HIS4 and Ho genes. In the PHO2 defective yeast strain, PHO5 gene could not be depressed in low Pi and the expression of the HIS4 and HO genes was decrease to 25% and 40% of the normal level respectively. When the PHO2 gene carried by low copy shuttle vector was transformed into this strain, the expression of the three genes could be restored. Previously the PHO2 gene was mutated on its conspicuous regions with site-directed mutagenesis, deletion and linker insertion. Here the effects of these mutations on these genes were compared.

Journal Article↗
PubMed1996

Studies on the Potential Phosphorylation Sites of the Yeast PHO2 Factor.

We report here that PHO2 protein is also phosphorylated by an unidentified protein kinase. A Ser-230 to Ala mutation in the consensus sequence (SPIK) recognized by cc2/CDC28-related kinase in the PHO2 protein led to the complete loss of its ability to activate the transcription of PHO5 gene. Further work showed that Pro-231 to Ser mutation inactivated PHO2 protein as well, while Ser-230 to Asp mutation did not affect PHO2 activity. Since PHO2 Asp-230 mutant mimics Ser-230 phosphorylated PHO2, we postulate that only phosphorylated PHO2 protein could activate the transcription of the PHO5 gene. The results of in vitro phospho-labelling experiments showed that the whole cell extract of the YPH499 strain grown under low phosphate conditions phosphorylated GST (glutathione S-transferase)- PHO2 (wild type) fusion protein, but not the GST-PHO2 mutant (Pro-231 to Ser) protein in which the putative phosphorylation sequence was destroyed. We therefore propose that the PHO2 protein may also be phosphorylated in vitro at Ser-230, and the phosphorylation of this site may be necessary for its function in controlling PHO5 gene expression.

Journal Article↗
PubMed1996

Interaction of the Yeast PH02 Protein or Its Mutants with the PHO5 UAS in vitro.

The GST gene fusion system was used to express PHO2 gene and its mutants in E. coli Gel retardation assays showed that PHO2 fusion protein can bind to the upstream activation sequence (UAS) of the acid phosphatase gene PHO5. The homeodomain of PHO2 protein has such structure as alpha-helix 2-beta-turn-alpha-helix 3, which acts as the DNA binding domain of the transcriptional factor. The Mutation of lle 123 to Pro in helix 3 or the insertion of 4 amino acids (PDPD) between 112 and 113 in alpha-helix 2 led to the complete loss of DNA-binding activity of PHO2, while the mutation of Pro 117 to Ala in beta-turn did not affect the binding activity significantly. Deletions of the PHO80 homologous region, acidic region or C-terminal 132 residues had no great effect on the DNA-binding activity, although these mutants had lost the ability to activate PHO5 expression in vivo.

Journal Article↗
PubMedDate not supplied

Molecularly imprinted polymer for monocrotophos and its binding characteristics for organophosphorus pesticides.

In this study, molecular imprinting was used to develop a method based on noncovalent interaction for the synthesis of a monocrotophos-specific polymer. The selective binding characteristics of the template polymer were evaluated by 1H NMR study. The result was consistent with the existence of multi-molecular complexes formed by hydrogen-bonding interactions. Batch rebinding studies in acetonitrile were undertaken to quantitatively evaluate the affinity of the polymer for monocrotophos. The experimental binding isotherms were fitted to the Freundlich isotherm and the total number of binding sites of the polymer can be calculated to be 4.046 micromol g(-1). The induced affinity and selectivity by imprinting were examined chromatographically. The polymer gave more than 15 times longer retention for monocrotophos than the nonimprinted polymer with the same chemical composition. Other organophosphorus pesticides under study were eluted close to the void volume on the polymer column.

Environmental Monitoring↗
PubMedDate not supplied

Cytokines in Mycoplasma pneumoniae infections.

Mycoplasma pneumoniae (M. pneumoniae) is one of the smallest free-living bacteria known. Along with other unique characteristics of this genus, it lacks the typical peptidoglycan cell wall of most eubacteria. Best known for causing tracheobronchitis and atypical pneumonia in humans, this pathogen also causes a number of extrapulmonary syndromes such as meningitis/encephalitis and arthritis. Recent studies also suggest that infection may be associated with chronic conditions such as asthma. Although the mechanisms of M. pneumoniae pathogenesis remain to be elucidated, one important component of M. pneumoniae infections is the induction of proinflammatory and other cytokines in both acute and chronic conditions. In this review, we survey the induction of cytokines by M. pneumoniae in different model systems, and we discuss the possible role of induced cytokines in M. pneumoniae pathogenesis.

Animals↗
PubMedDate not supplied

Up-regulation of the expression of cocaine and amphetamine-regulated transcript peptide by electroacupuncture in the arcuate nucleus of diet-induced obese rats.

It was reported that acupuncture or electro-acupuncture (EA) is effective in reducing the body weight for obese patients, although the mechanisms remain obscure. In a previous study, we have found that rats fed with high-fat (HIF) diet developed diet-induced obesity (DIO) with a concomitant decrease in the hypothalamic content of the cocaine and amphetamine-regulated transcript (CART) peptide, a peptide with anorexiogenic effect. To assess the central effect of EA on DIO rat, we revealed that EA up-regulated the expression of CART peptide in the arcuate nucleus (ARC) of the DIO rats. After feeding with HIF diet for 14 weeks, the DIO rats received EA stimulation three times per week for 4 weeks. The expression of CART peptide in ARC was measured using immunohistochemistry. The plasma ACTH was measured with ELISA. EA caused a reduction of both body weight and energy intake in DIO rats and increased the expression of CART peptide in ARC. The plasma ACTH was increased in response to restraint stress, but EA produced no further increase in ACTH levels. The results suggest that EA can up-regulate the expression of CART peptide to approach normal level, resulting in an inhibition of food intake and a reduction of body weight in DIO rats.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Pancreatic elastase induces liver injury by activating cytokine production within Kupffer cells via nuclear factor-Kappa B.

Liver injury is a manifestation of the systemic inflammatory response during acute pancreatitis. We have demonstrated that elastase induces macrophage tumor necrosis factor (TNF) production in distant organs, thus mimicking pancreatitis-associated organ injury. The aim of this study was to determine the mechanism by which elastase induces hepatic cytokine production. Rat livers (n = 40) were perfused with elastase +/- gadolinium (Gd) to inhibit Kupffer cells. Liver parenchymal enzymes and TNF were measured in the effluent. In vitro, rat hepatocytes or Kupffer cells were treated with elastase (1 U/ml) +/- Gd (0.5 mg/ml) or pyrrolidine dithiocarbamate (PDTC; 0.5 mg/ml). TNF protein, TNF messenger RNA, and NF-kappa B activation were determined. In vivo, Gd blunted the elastase-induced TNF production and decreased AST, ALT, LDH, and nonviable cells (propidium iodide) (P < or= 0.03 vs. elastase). In vitro, elastase induced TNF production from Kupffer cells (P < 0.001 vs. control) but not from hepatocytes. Gd or PDTC significantly attenuated the elastase-induced TNF production (P < 0.001). Elastase-induced overexpression of TNF messengerRNA and activation of NF-kappa B was attenuated by Gd. Pancreatic elastase induces a pattern of liver injury similar to that seen during acute pancreatitis by activating cytokine production and gene expression within Kupffer cells via NF-kappa B. Gd exhibits a protective effect against elastase-induced liver injury by inhibiting activation of NF-kappa B.

Animals↗
PubMedDate not supplied

Use of monofilament in the detection of foot lesions in older adults.

The purpose of this study was to compare Semmes-Weinstein monofilament testing between elderly and young patients in both a diabetic and nondiabetic population. Monofilament mapping (10 g) was performed on 115 patients: 74 who were greater than 60 years of age (47 with diabetes) and 41 who were younger than 60 years (20 with diabetes). Sensations were assessed at 15 predefined pressure/risk points. Sensations were found to have perfect correlation between the same point on the left and right foot (r = 1.0) for each of the 15 points. The data for the 15 points were divided in 2 subsets: one for 8 points similar to a validated method and another with 7 new points on the dorsum and ankle area. Scores on both subsets differed significantly by age group (P < .0001) and diabetes status (P < .001), with older patients and patients with diabetes having higher scores. Analysis of covariance was used to estimate 15-point scores for the 4 combinations of age group and diabetes status, adjusting for foot ulceration, callus, deformity, and ischemia. In older patients without diabetes, each subset score was used to detect future neuropathy if 4 or more points were insensitive. The detections agreed in 37 of 47 cases. In all 10 cases of disagreement, the 7-point subset detected no neuropathy, suggesting that inclusion of the additional points could improve diagnostic specificity. The significant differences noted between young and old patients suggest the importance of aging-related changes, and raise questions about current scoring methods for detection of neuropathy in older adults with diabetes.

Adult↗
PubMedDate not supplied

Identification, cloning, and characterization of microsatellite DNA in Euglena gracilis.

Microsatellite DNA has been developed into one of the most popular genetic markers. We have identified and cloned microsatellite loci in the genome of a free-living protozoan Euglena gracilis FACHB-848, using the random amplified microsatellites method (RAMS). The digoxigenin-labelled oligonucleotides (CT)10 and (GT)10 served as probes to detect complementary sequences in the randomly amplified polymorphic DNA (RAPD) fingerprints produced by means of Southern blotting. Subsequently, positive RAPD fragments were cloned. From a total of 31 RAPD primer profiles, eight microsatellite loci of E. gracilis were detected and characterized. Further, six sites (i.e. EGMS1, EGMS3, EGMS4, EGMS5, EGMS6, and EGMS7) showed polymorphisms. We found a GT or CT microsatellite every 10.5 kb in the genome of E. gracilis, and similar to animal genomes, the (GT)(n) motif was much more abundant than the (CT)(n) motif. These polymorphic microsatellite DNA will serve as advantageous molecular markers for studying the genetic diversity and molecular ecology of Euglena.

Animals↗
PubMedDate not supplied

Population genetic structure of Carchesium polypinum (Ciliophora: Peritrichia) in four Chinese lakes inferred from ISSR fingerprinting: high diversity but low differentiation.

Although the peritrichous ciliate Carchesium polypinum is common in freshwater, its population genetic structure is largely unknown. We used inter-simple sequence repeat (ISSR) fingerprinting to analyze the genetic structure of 48 different isolates of the species from four lakes in Wuhan, central China. Using eight polymorphic primers, 81 discernible DNA fragments were detected, among which 76 (93.83%) were polymorphic, indicating high genetic diversity at the isolate level. Further, Nei's gene diversity (h) and Shannon's Information index (I) between the different isolates both revealed a remarkable genetic diversity, higher than previously indicated by their morphology. At the same time, substantial gene flow was found. So the main factors responsible for the high level of diversity within populations are probably due to conjugation (sexual reproduction) and wide distribution of swarmers. Analysis of molecular variance (AMOVA) showed that there was low genetic differentiation among the four populations probably due to common ancestry and flooding events. The cluster analysis and principal component analysis (PCA) suggested that genotypes isolated from the same lake displayed a higher genetic similarity than those from different lakes. Both analyses separated C. polypinum isolates into subgroups according to the geographical locations. However, there is only a weak positive correlation between the genetic distance and geographical distance, suggesting a minor effect of geographical distance on the distribution of genetic diversity between populations of C. polypinum at the local level. In conclusion, our studies clearly demonstrated that a single morphospecies may harbor high levels of genetic diversity, and that the degree of resolution offered by morphology as a marker for measuring distribution patterns of genetically distinct entities is too low.

Animals↗