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Biomedical subjects

Jun Yang

Publications and source records attributed to Jun Yang.

At least 253 records · Page 14Linked to original sources
PubMed2004

Transcriptional regulation of cardiac sarcoplasmic reticulum calcium-ATPase gene during the progression of sepsis.

Changes in sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) gene expression in the rat heart during different phases of sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). Septic rats were divided into two groups: the early hyperdynamic (9 h after CLP, early sepsis) and the late hypodynamic (18 h after CLP; late sepsis) groups. Western blot analyses reveal that SERCA2a protein level remained unaltered during early sepsis but was decreased by 59% during late sepsis. Northern blot analyses show that the steady-state level of SERCA2a mRNA stayed unchanged during the early phase but was decreased by 43% during the late phase of sepsis. Nuclear runoff assays show that the transcription rate of SERCA2a gene transcript remained unaffected during early sepsis but was decreased by 34% during late sepsis. The actinomycin D pulse-chase studies indicate that the half-life of SERCA2a mRNA was unaffected during the early and the late phases of sepsis. These findings demonstrate that during the early phase of sepsis, the protein level, the mRNA abundance, and the transcription rate of SERCA2a remained unaltered, whereas during the late phase of sepsis, the rate of transcription of SERCA2a was decreased, and the decreased transcription rate was associated with decreases in SERCA2a mRNA abundance and SERCA2a protein level in the rat heart. Based on these data, it is concluded that SERCA2a gene expression decreased during the late phase of sepsis in the rat heart and that the decreased expression was regulated at the transcriptional level.

Animals↗
PubMed2004

Interactions amongst rabies virus nucleoprotein, phosphoprotein and genomic RNA in virus-infected and transfected cells.

Previous in vitro studies have indicated that rabies virus (RV) phosphoprotein (P), by interacting with the nucleoprotein (N), confers the specificity of genomic RNA encapsidation by N. In this study, interactions amongst N, P and the genomic RNA in virus-infected as well as in transfected cells were studied. The results showed that when N was expressed alone, it bound non-specific RNA, particularly the N mRNA. When N and P were co-expressed, they formed N-P complexes that did not bind to non-specific RNA. When N and P were co-expressed together with (mini-)genomic RNA, N-P complexes preferentially bound the (mini-)genomic RNA. This demonstrated that RV P, by binding to N, does indeed confer specificity of genomic RNA encapsidation by N in vivo. Furthermore, the role of N phosphorylation in the N, P and RNA interactions was investigated. It was found that only N that bound to RNA was phosphorylated, while N in the N-P complex prior to RNA encapsidation was not, suggesting that RV P, by binding to nascent N, prevents the immediate phosphorylation of de novo-synthesized N. However, mutation at the phosphorylation site of N did not alter the pattern of N-P and N-RNA interactions, indicating that N phosphorylation per se does not play a direct role in N-P interaction and RNA encapsidation.

Animals↗
PubMed2004

Gene expression signatures in chronic and aggressive periodontitis: a pilot study.

This pilot study examined gene expression signatures in pathological gingival tissues of subjects with chronic or aggressive periodontitis, and explored whether new subclasses of periodontitis can be identified based on gene expression profiles. A total of 14 patients, seven with chronic and seven with aggressive periodontitis, were examined with respect to clinical periodontal status, composition of subgingival bacterial plaque assessed by checkerboard hybridizations, and levels of serum IgG antibodies to periodontal bacteria assayed by checkerboard immunoblotting. In addition, at least two pathological pockets/patient were biopsied, processed for RNA extraction, amplification and labeling, and used to study gene expression using Affymetrix U-133 A arrays. Based on a total of 35 microarrays, no significantly different gene expression profiles appeared to emerge between chronic and aggressive periodontitis. However, a de novo grouping of the 14 subjects into two fairly robust clusters was possible based on similarities in gene expression. These two groups had similar clinical periodontal status and subgingival bacterial profiles, but differed significantly with respect to serum IgG levels against the important periodontal pathogens Porphyromonas gingivalis, Tannerella forsythensis and Campylobacter rectus. These early data point to the usefulness of gene expression profiling techniques in the identification of subclasses of periodontitis with common pathobiology.

Acute Disease↗
PubMed2004

Characterization of the common wheat (Triticum aestivum L.) mutation line producing three pistils in a floret.

In a normal wheat (Triticum ssp.L.) spike, one floret carries only one pistil that will further develop into one grain after fertilization. The cultivated common wheat (T. aestivum L.) mutation line Three Pistils (TP) carried three pistils in a floret. Although one or two of the pistils died out before seed set in some florets, there were exist many florets that set three seeds. Normally, it was observed that there were one to three seeds in different florets of the same spike. Therefore, this mutation trait could raise considerably the number of grains per spike. The weight of 100 grains in three seeds set florets was lower than that of in one seed set florets. But three seeds set florets were significantly to surpass the one seed set florets in grain(s) weight per floret. Based on these results, the three pistils trait was suggested to be an interesting germplasm resource. Localisation of the gene controlling the three pistils trait was carried out by the method of crossing TP with the Chinese Spring disomic substitutions. F2 population segregation analysis revealed that only the 5B F2 population did not show homogeneity to control population. chi2-test analysis indicated that 5B F2 population, and only this population, was deviated from the Mendelian segregation ratio (3:1). As a conclusion, the gene for three pistils trait was located on chromosome 5B. According to the Recommended rules for gene symbolization in wheat, the name of the dominant gene for three pistils trait in the line TP was suggested as Pis1.

Genes, Plant↗
PubMed2004

Trends in prevalence, awareness, treatment and control of hypertension in the middle-aged population of China, 1992-1998.

The objective of this study was to analyze the trends in prevalence, awareness, treatment and control of hypertension in the middle-aged population of China. There were about 1,000 participants each from 13 different study populations that were examined in surveys conducted from 1992-1994 (n=18,746) and in 1998 (n=13,504) in conjunction with the China Multi-Center Study of Cardiovascular Epidemiology. Half the subjects were men and half were women; their ages ranged from 35 to 59 years. Hypertension was defined as systolic blood pressure > or =140 mmHg, diastolic blood pressure > or =90 mmHg, and/or current treatment with antihypertensive medications. Hypertension awareness and treatment were assessed with a standardized questionnaire. Hypertension control was defined as blood pressure measurements of less than 140/90 mmHg. The results showed that 24.0% of participants had hypertension in 1998, an increase of 2.3% from 1992-1994 (p <0.05). The prevalence of hypertension was 25.4% higher in urban than in rural areas, and was higher in men than in women. Among hypertensives, 42.6% were aware of their hypertension (a 5.3% increase compared with 1992-1994, p <0.05), 31.1% were treated (a 3.8% increase, p <0.05), and 6.0% were controlled (a 2.6% increase, p <0.05). The rates of awareness, treatment and control were higher in women than men, and higher in urban than rural areas. For treated hypertensives, the rate of control increased from 12.7% in 1992-1994 to 19.9% in 1998 (p <0.05). These findings indicate that hypertension prevalence is increasing in China. Control rates, while improving, still remain low. This implies that effective public health measures are needed to enhance the awareness, treatment, and control rates in the Chinese population.

Adult↗
PubMed2004

Ceramide and other sphingolipids in cellular responses.

Formerly considered to serve only as structural components, sphingolipids are emerging as an important group of signaling molecules involved in many cellular events, including cell growth, senescence, meiotic maturation, and cell death. They are also implicated in functions such as inflammation and the responses to heat shock and genotoxic stress. Defects in the metabolism of sphingolipids are related to various genetic disorders, and sphingolipids have the potential to serve as therapeutic agents for human diseases such as colon cancer and viral or bacterial infections. The best-studied member of this family, ceramide, which also serves as the structural backbone for other sphingolipids, is an important mediator in multiple cellular signaling pathways. The metabolism and functions of sphingolipids are discussed in this review, with a focus on ceramide regulation in various cellular responses.

Apoptosis↗
PubMed2004

Oligomeric beta-structure of the membrane-bound HIV-1 fusion peptide formed from soluble monomers.

The human immunodeficiency virus type 1 (HIV-1) fusion peptide serves as a useful model system for understanding viral/target cell fusion, at least to the lipid mixing stage. Previous solid-state NMR studies have shown that the peptide adopts an oligomeric beta-strand structure when associated with a lipid and cholesterol mixture close to that of membranes of host cells of the virus. In this study, this structure was further investigated using four different peptide constructs. In aqueous buffer solution, two of the constructs were primarily monomeric whereas the other two constructs had significant populations of oligomers/aggregates. NMR measurements for all membrane-associated peptide constructs were consistent with oligomeric beta-strand structure. Thus, constructs that are monomeric in solution can be converted to oligomers as a result of membrane association. In addition, samples prepared by very different methods had very similar NMR spectra, which indicates that the beta-strand structure is an equilibrium rather than a kinetically trapped structure. Lipid mixing assays were performed to assess the fusogenicities of the different constructs, and there was not a linear correlation between the solution oligomeric state and fusogenicity. However, the functional assays do suggest that small oligomers may be more fusogenic than either monomers or large aggregates.

Cholesterol↗
PubMed2004

[Determination of luteolin and luteolin-7-beta-D-glucoside in Chrysanthemum morfolium Ramat. from different collection time by RP-HPLC].

OBJECTIVE: To observe the content variation of luteolin and luteolin-7-beta-D-glucoside in Chrysanthemum morifolium Ramat. (CMR) from different collection time. METHODS: RP-HPLC was used to analyze these two components in CMR collected in 2001 and 2002. RESULT: The content of luteolin was significantly lower than that of luteolin-7-beta-D-glucoside. Furthermore, the former showed no marked changes during collection, while the latter did not varied markedly in early collection but decreased significantly in later collection. CONCLUSION: The content of luteolin-7-beta-D-glucoside reflects the quality of Chrysanthemum morifolium Ramat. more viably than that of luteolin.

Chromatography, High Pressure Liquid↗
PubMed2004

[Protective effect of continuous veno-venous hemofiltration on tissue and organ damage in patients with severe acute pancreatitis].

OBJECTIVE: To explore the protective effect of continuous veno-venous hemofiltration (CVVH) on tissue and organ damage induced by severe acute pancreatitis (SAP). METHODS: Thirty-seven SAP patients were randomly divided into CVVH group (n=22) and control group (n=15). Patients in control group were treated with conventional therapy, while patients in CVVH group were treated with conventional therapy combined with CVVH. Serum amylase (AMS) and lipase (Lip), the plasma levels of endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and C-reactive protein (CRP), and faecal occult blood test and blood serum leukocyte were determined. Functions of brain, kidney, liver, heart and lung were observed. RESULTS: The treatment effect was better in CVVH group than that in normal group. The mortality rate was lower and the number of hospitalization day was decreased in CVVH group than those in normal group, they were 18.2 percent vs. 33.3 percent and (18.3+/-5.7) days vs. (27.5+/-8.6) days. CONCLUSION: CVVH has a significant protective effect against tissue and organ damage induced by SAP.

Acute Disease↗
PubMed2004

Expression of human alpha-galactosidase and alpha1,2-fucosyltransferase genes modifies the cell surface Galalpha1,3Gal antigen and confers resistance to human serum-mediated cytolysis.

OBJECTIVE: To explore the strategies which reduce the amount of xenoantigen Galalpha1,3Gal. METHODS: Human alpha-galactosidase gene and alpha1,2-fucosyltransferase gene were transferred into cultured porcine vascular endothelial cells PEDSV.15 and human alpha-galactosidase transgenic mice were produced. The Galalpha1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed. RESULTS: Human alpha-galactosidase gene alone reduced 78% of Galalpha1,3Gal on PEDSV.15 cell surface while human alpha-galactosidase combined with alpha1,2-fucosyltransferase genes removed Galalpha1,3Gal completely. Decrease of Galalpha1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of alpha-galactosidase gene and alpha1,2-fucosyltransferase gene. RT-PCR indicated positive human alpha-galactosidase gene expression in all organs of positive human alpha-galactosidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galalpha1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by complement-mediated lysis compared with 24% of those from normal mice. CONCLUSIONS: Human alpha-galactosidase gene and alpha1,2-fucosyltransferase gene effectively reduce the expression of Galalpha1,3Gal antigens on endothelial cell surface and confers resistance to human serum-mediated cytolysis. The expression of human alpha-galactosidase in mice can also eliminate the Galalpha1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis.

Animals↗
PubMed2004

[Chemical components of Vetiveria zizanioides volatiles].

The chemical components of the volatiles from Vetiveria zizanioides were analyzed by SPME and GC-MS. In the roots, the main component was valencene (30.36%), while in the shoots and leaves, they were 9-octadecenamide (33.50%), 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene (27.46%), and 1,2-benzendicarboxylic acid, diisooctyl ester(18.29%). The results showed that there were many terpenoids in the volatils. In shoot volatiles, there existed 3 monoterpenes, 2 sequiterpenes and 1 triterpene. Most of the volatiles in roots were sesquiterpenes.

Gas Chromatography-Mass Spectrometry↗
PubMed2004

[Correlation between mannose-binding lectin gene codon 54 polymorphism and susceptibility of Kawasaki disease].

OBJECTIVE: Human mannose-binding lectin (MBL) is a C-type serum lectin synthesized by the liver as an acute-phase protein. MBL can bind to glycoproteins terminated with mannose and N-acetylglucosamine present in the cell walls on a variety of microorganisms. Therefore, MBL appears to play an important role in the immune system. Low levels of MBL in human have been associated with a susceptibility to recurrent infections. MBL deficiency and low serum MBL levels are strongly associated with the presence of three point mutations at codon 52, 54 and 57 of exon 1 in the human MBL gene, and in Chinese population, the codon-54 mutation occurs at a frequency of 0.11 - 0.17. The data suggested that MBL insufficiency might also predispose to the development of autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). The possibility that Kawasaki disease (KD) is an infectious disease has been discussed and investigated for decades, in light of the implication that infections are involved in the pathogenesis of KD. It has been suggested that MBL insufficiency might predispose to the occurrence of KD. This study was aimed to investigate the genetic association of MBL codon-54 polymorphism in patients with KD, and to investigate possible associations with clinical manifestations of the disease. METHODS: There were 95 patients with KD and 160 healthy subjects in the study. The genotype of MBL gene 54 codon was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Clinical characteristics and biochemical examination were also performed. RESULTS: The genotype frequency of heterozygote (GGC/GAC) was significantly higher in KD group than that in healthy subjects (45.2% vs 25.0%, P < 0.01), and the allele frequency of GAC mutation was also higher in KD patients than that in control group (0.258 vs 0.138, P < 0.01). The variant allele (GAC) was markedly associated with KD (OR = 2.18, 95% CI = 1.38 approximately 3.44, P < 0.05). But there was no significant difference in the allele frequency of GAC between patients with and without coronary artery lesion (CAL) in KD cases (0.281 vs 0.246, P > 0.05). In addition, in cases of KD, more patients carrying the variant allele (GAC) had episodes of upper respiratory or gastrointestinal infections prior to the onset of KD than wild homozygotes (P < 0.01). CONCLUSION: The codon 54 polymorphism of MBL gene was associated with KD. It is possible that MBL gene codon 54 mutation might be related to the pathogenesis of KD.

Child↗
PubMed2004

[Antisense human telomerase reverse transcriptase inhibits leukemia cell proliferation in vitro].

OBJECTIVE: To study the inhibitory effect of antisense human telomerase reverse transcriptase (hTERT) on leukemia cell proliferation in vitro. METHODS: Sense and antisense hTERT eukaryotic expression vectors previously constructed were transfected into leukemia cell line HL(60) using SuperFect transfection reagent (Qiagen) to obtain HL(60)-s and HL(60)-as, and the G418-resistant colonies were identified for the presence of hTERT insert by PCR with T7 and pcDNA3.1/BGH reverse primers. Endogenous hTERT mRNA expression and telomerase activity were then detected by quantitative real-time RT-PCR and telomerase associated protein -silver staining in each cell line. MTT cellular proliferation assay, soft agar colony formation assay and flow cytometry were also employed to analyze the changes in proliferation capacity of leukemia cell in vitro and apoptosis of the tumor cells induced by antisense hTERT. RESULTS: Antisense hTERT remarkably reduced endogenous hTERT mRNA expression (P<0.01) and down-regulated telomerase activity in HL(60), as compared with the blank control and sense hTERT. After 25 passages of the 3 cell lines, a 7-day cell growth curve and the numbers (size) of soft agar colony formation showed that the proliferation rates and the anchorage-independent growth ability of HL(60)-as cells were significantly decreased in comparison with HL(60) and HL(60)-s cells, but a significant increase in apoptosis of HL(60)-as cells occurred as determined by flow cytometry. CONCLUSIONS: Antisense hTERT can obviously inhibit leukemia cell growth and proliferation in vitro, and this telomerase-targeted molecular biotherapy may be achieved by apoptosis pathway through down-regulation of hTERT mRNA and telomerase activity.

Antisense Elements (Genetics)↗
PubMed2004

[Trends in prevalence, awareness, treatment and control of hypertension in middle-aged Chinese population].

OBJECTIVE: To analyze the trends in prevalence, awareness, treatment, control of hypertension among middle-aged Chinese. METHODS: The study comprised two cross-sectional surveys including urban and rural residents, manual workers, farmers and fishermen in different southern and northern parts of China. There were 13 populations under research with comparable data. 18 746 (in 1992 - 1994) and 13 504 (in 1998) participants, aged 35 through 59 years, equal number of men and women, were examined in each of the surveys, on blood pressure measurement, in 1992 - 1994 and in 1998. Hypertension was defined as systolic pressure >/= 140 mm Hg, and/or diastolic pressure >/= 90 mm Hg, and/or reported treatment with antihypertensive medications. Awareness and treatment on hypertension were assessed with standardized questions. Hypertension control was defined as measured blood pressure of less than 140/90 mm Hg. Awareness, treatment and control of hypertension were standardized according to the WHO world standard population. RESULTS: In 1998, 24.0% of participants had hypertension, an increase of 2.3% from 1992 - 1994. Prevalence of hypertension was higher in urban area (25.4%), increasing with age, and higher in men among the younger groups and lower in women among the older groups. Overall, in 1998, 42.6% were aware of their hypertensive status (increase of 5.3%), 31.3% were treated (increase of 3.8%), and the rate under control was 6.0% (increase of 2.6%). The rates of awareness, treatment and control, which tended to increase with age except those aged above 55 years, which were higher in urban areas and women compared with rural areas and men. For people with treated hypertension, the rates of those under control were ranged from 12.7% in 1992 - 1994, to 19.9% in 1998. CONCLUSION: Prevalence of hypertension was increasing in China, while the rates of control, although improving, continued to be low. This implied that effective public measures needed to be developed to enhance the awareness and rates of treatment.

Adult↗
PubMed2004

[Construction and screening of the human phage antibody library from a patient with melanoma].

AIM: To construct and screen the human phage antibody library from a patient with melanoma. METHODS: Total RNA was extracted from the peripheral blood mononuclear cells (PBMCs) of a patient with melanoma who has survived for twenty years. The heavy chain Fd fragments and kappa light chains were amplified by RT-PCR. The amplified products were cloned into phagemid vector to construct Fab antibody library. The library was panned with two kinds of melanoma cells for 4 rounds. RESULTS: Antibody library contained 1.2 x 10(8) different clones. Specific phage antibodies against one of the two melanoma cells were obtained after 4 rounds of panning. CONCLUSION: Specific human phage antibodies against melanoma cells were obtained.

Antibodies, Neoplasm↗
PubMed2004

[Antisense hTERT inhibits gene expression and functional activity of telomerase in leukemia cell lines].

OBJECTIVE: To explore the inhibitory effects of gene expression and functional activity of telomerase in leukemia cell lines by in vitro antisense hTERT treatment. METHODS: An antisense hTERT eukaryotic expression vector was constructed by using gene recombination technique, targeting the 5' end mRNA sequence of the telomerase catalytic subunit. The vector expression in leukemia cell lines (HL60 and K562) was achieved by transfection using the SuperFect transfection reagent (Qiagen). After transfection, ectopic expression of the telomerase catalytic subunit was analyzed by quantitative fluorescence real-time RT-PCR, and cellular apoptosis and cell cycle parameters were evaluated by flow cytometry respectively. RESULTS: An antisense pcDNA-hTERT eukaryotic expression vector was successfully constructed. Leukemia cell lines transfected with antisense hTERT constructed displayed a significant inhibition of gene expression of telomerase and its activity in vitro, as compared with the result of the control groups (without transfection and vector control). CONCLUSION: In-vitro antisense hTERT expression may down-regulate the gene expression and biological activity of telomerase in leukemia cells, suggesting a possibility of gene therapy against human malignancy through the telomerase-targeted molecular mechanism.

Apoptosis↗