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Biomedical subjects

Yuan Yang

Publications and source records attributed to Yuan Yang.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Novel mutations of cathepsin C gene in two Chinese patients with Papillon-Lefèvre syndrome].

OBJECTIVE: To investigate the mutational characteristics of cathepsin C (CTSC) gene in two Chinese patients with Papillon-Lefèvre syndrome (PLS), and provide molecular basis for research of the pathogenesis of PLS. METHODS: Peripheral blood samples were obtained from patients and their parents respectively. Genomic DNA were extracted after consents. Polymerase chain reaction, direct DNA sequencing and restriction enzyme reaction were performed to screen mutations of CTSC gene. RESULTS: Compound heterozygous mutations of CTSC gene were identified in the two patients. Patient I carried the G139R and S260P mutations, patient II had the R250X and C258W mutations. The parents were heterozygous carriers without the clinical feature of PLS. None of the mutations were detected in normal controls. Furthermore, the S260P and C258W changes were novel mutations of CTSC gene, which had not been reported previously. CONCLUSIONS: Mutations of CTSC gene are responsible for the phenotype of Papillon-Lefèvre syndrome in two Chinese patients. The results extend the mutation spectrum of CTSC gene and also provide basis for gene diagnosis of PLS in China.

Asian People↗
PubMed2006

[Mitochondrial DNA4568 deletions in guinea-pig associated with presbycusis].

OBJECTIVE: To determine weather or not the mtDNA(4568) deletions in guinea-pig contribute to the development of presbycusis. METHODS: Forty-four guinea-pigs were divided into 2 groups: group A (young control group, normal hearing, 22 guineas) and group B (aged group). The group B was subdivided into group B(1) (old normal hearing, 6 guineas) and group B(2) (old hearing loss, 16 guineas). First the guineas were tested by auditory brainstem response (ABR), and then the Cortis's tissues, auditory nerve tissues, brain and blood were harvested and the total DNA was extracted. The mtDNA(4568) deletion was analyzed by PCR. RESULTS: Hearing loss was occurred with age. The mtDNA(4568) deletion incidence of aged group in all tissues was significant higher than that of young control group (P< 0.05). The incidence of mtDNA deletion in Cortis's and auditory nerve with presbycusis (B(2) group) were significant higher than that of aged normal hearing group (B(1) group) (P< 0.05). The incidence of mtDNA deletion in brain and blood was not significantly different between presbycusis and aged normal hearing group (P> 0.05). CONCLUSION: mtDNA(4568) deletion of guinea-pig possibly contributes to aging and mtDNA(4568) deletion in Cortis's and auditory nerve tissues of guinea-pig may be associated with presbycusis. There is no enough evidence to prove that the mtDNA(4568) deletions in brain and blood are related with presbycusis.

Age Factors↗
PubMed2005

Single nucleotide polymorphisms of the gonadotrophin-regulated testicular helicase (GRTH) gene may be associated with the human spermatogenesis impairment.

BACKGROUND: Gonadotropin-regulated testicular RNA helicase (GRTH) is a testis-specific RNA helicase that is essential for completion of spermatogenesis and is involved in pathogenesis of impaired spermatogenesis in mouse. It is therefore reasonable to postulate that human GRTH gene may also play a role in impaired spermatogenesis in humans. To test this hypothesis, we investigated the possible association between the variations of the GRTH gene and human spermatogenesis impairment. METHODS: Mutation screening of exons and intron/exon boundaries of GRTH gene was carried out by denaturing high-performance liquid chromatography (DHPLC) in 347 infertile patients with idiopathic azoospermia and severe oligozoospermia as well as 201 fertile men. RESULTS: Four single nucleotide polymorphisms (SNP), namely IVS6+55G-->T, ISV8+10A-->C, c.852C-->T and c.927G-->A, were identified. Among them, significant differences in polymorphism frequencies were observed at the polymorphic IVS6+55G-->T and c.852C-->T loci between the patients and controls, and a significant association between haplotypes of these two loci and male infertility with impaired spermatogenesis was detected. CONCLUSIONS: Results of the present study indicate that SNP IVS6+55G-->T and c.852C-->T of GRTH gene may be associated with male infertility with azoospermia or severe oligozoospermia, suggesting that variations in GRTH gene may contribute to susceptibility to spermatogenic impairment in humans.

Base Sequence↗
PubMed2005

The common variant N372H in BRCA2 gene may be associated with idiopathic male infertility with azoospermia or severe oligozoospermia.

OBJECTIVE: To explore the possible association between the common single nucleotide polymorphism N372H in human breast cancer susceptibility gene 2 (BRCA2) and the idiopathic male infertility with azoospermia or severe oligozoospermia. STUDY DESIGN: The study included 240 infertile patients with idiopathic azoospermia or severe oligozoospermia and 250 fathered controls. The allele and genotype frequencies of the polymorphism N372H in BRCA2 gene were investigated in both patients and controls using denaturing high performance liquid chromatography analysis (DHPLC). RESULTS: The frequency of allele H of the polymorphism N372H in patients was significantly higher than that of the controls (23.5% versus 17.6%, OR = 1.49, 95% CI 1.06-1.97, P = 0.02) and the subjects bearing rare allele H (NH + HH) significantly increased in patients compared with controls (41.7% versus 32.4%, 95% CI 1.03-2.15, P = 0.03). CONCLUSION: The results of this study suggested that the polymorphism N372H in BRCA2 gene may be associated with idiopathic male infertility with azoospermia or severe oligozoospermia.

Chromatography, High Pressure Liquid↗
PubMed2005

Screening of hepatocyte proteins binding to F protein of hepatitis C virus by yeast two-hybrid system.

AIM: To investigate the biological function of F protein by yeast two-hybrid system. METHODS: We constructed F protein bait plasmid by cloning the gene of F protein into pGBKT7, then recombinant plasmid DNA was transformed into yeast AH109 (a type). The transformed yeast AH109 was mated with yeast Y187 (alpha type) containing liver cDNA library plasmid in 2XYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing X-alpha-gal for selection and screening. After extracting and sequencing plasmids from positive (blue) colonies, we underwent sequence analysis by bioinformatics. RESULTS: Thirty-six colonies were selected and sequenced. Among them, 11 colonies were zymogen granule protein, 5 colonies were zinc finger protein, 4 colonies were zinc-alpha-2-glycoprotein, 1 colony was sialyltransferase, 1 colony was complement control protein factor I, 1 colony was vitronectin, and 2 colonies were new genes with unknown function. CONCLUSION: The yeast two-hybrid system is an effective method for identifying hepatocyte proteins interacting with F protein of hepatitis C virus. F protein may bind to different proteins.

Cell Line, Tumor↗
PubMed2005

Screening of genes of proteins interacting with p7 protein of hepatitis C virus from human liver cDNA library by yeast two-hybrid system.

AIM: To investigate the biological function of p7 protein and to look for proteins interacting with p7 protein in hepatocytes. METHODS: We constructed p7 protein bait plasmid by cloning the gene of p7 protein into pGBKT7, then transformed it into yeast AH109 (a type). The transformed yeast was mated with yeast Y187 (alpha type) containing liver cDNA library plasmid, pACT2 in 2XYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-alpha-gal for selection and screening. After extracting and sequencing of plasmids from blue colonies, we performed sequence analysis by bioinformatics. RESULTS: Fifty colonies were selected and sequenced. Among them, one colony was Homo sapiens signal sequence receptor, seven colonies were Homo sapiens H19, seven colonies were immunoglobulin superfamily containing leucine-rich repeat, three colonies were spermatid peri-nuclear RNA binding proteins, two colonies were membrane-spanning 4-domains, 24 colonies were cancer-associated antigens, four colonies were nucleoporin 214 ku and two colonies were CLL-associated antigens. CONCLUSION: The successful cloning of gene of protein interacting with p7 protein paves a way for the study of the physiological function of p7 protein and its associated protein.

Base Sequence↗
PubMed2005

[Possible association between 278C/A single nucleotide polymorphism of FKBP6 and idiopathic azoospermia].

OBJECTIVE: To investigate 2 polymorphism sites in exon 3 and intron 2 of FKBP6 in Chinese population, while screening the gene mutations and polymorphisms in exons 3, 4 of FKBP6, and the association of these polymorphisms with azoospermia. METHODS: Possible variations of exons 3, 4 and genotypes and frequencies of 2 polymorphic loci were examined by denaturing high-performance liquid chromatography(DHPLC) and PCR-restriction fragment length polymorphism(PCR-RFLP) technique in 177 azoospermia patients and 231 control individuals. RESULTS: The observed allele frequencies conformed well to Hardy-Weinberg equilibrium. The frequency of 278A allele was significantly higher in controls than that in patients (P<0.05). C/T(s7797242) polymorphism was not found in either group and variations in exons 3, 4 were not detected. CONCLUSION: 278A polymorphism of FKBP6 gene was associated with idiopathic azoospermia, while C/T, 370G/A, 430G/C, 467T/C, 468G/A polymorphisms might be very rare in Chinese population.

Azoospermia↗
PubMed2005

[Relationship between the increase of hepatic D-bifunctional protein activity and bile acid biosynthesis in rats].

OBJECTIVE: To determine the physiological role of D-bifunctional protein (DBP) in bile acid biosynthesis through investigating the effect of increasing activity of DBP on bile acid biosynthesis. METHODS: Twenty male Wistar rats were divided into two groups: diethylhexyl phthalate (DEHP) group (n = 10) and control group (n = 10). Serum triglyceride, total cholesterol, hepatic DBP activity, and fecal bile acids were assayed. The mRNA levels of hepatic peroxisome proliferator-activated receptor alpha (PPARalpha), DBP, and cholesterol 7alpha-hydroxylase (CYP7A1) were detected by RT-PCR. RESULTS: Compared with control group, serum triglyceride level was decreased significantly and PPARalphamRNA level was increased significantly in DEHP group (P < 0.01). Together with a sharp induction of DBP mRNA expression and DBP activity in DEHP group (P < 0.01), the levels of CYP7A1 mRNA and fecal bile acids were significantly increased by 1.9 times and 1.6 times respectively compared to control group (P < 0.01). There was a significantly positive correlation between DBP mRNA level or DBP activity and CYP7A1 mRNA level (r = 0.89, P < 0.01; r = 0.95, P < 0.01). CONCLUSION: The up-regulation of DBP mRNA and activity in liver can result in the increase in CYP7A1 mRNA expression and bile acid biosynthesis, suggesting that DBP may be involved in bile acid biosynthesis together with CYP7A1.

17-Hydroxysteroid Dehydrogenases↗
PubMed2005

[Important genetic etiology of infertile Chinese males: chromosome abnormality and deletion of DAZ gene copy in the AZFc region of Y chromosome].

OBJECTIVE: To investigate the correlation of male infertility with abnormality of chromosomal quantity and construction and with the deletion of DAZ gene copy in the AZFc region of Y chromosome. METHODS: Included in the study were 247 azoospermic and 206 severe oligozoospermic patients, as well as 210 fertile men as controls. Multi-PCR and PCR-RFLP were used to analyze the deletion of DAZ gene copies in the AZFc region of Y chromosome. Chromosomal quantity and construction were detected by G-band in the 453 patients. RESULTS: In the azoospermic and severe oligozoospermic patients, the incidences of chromosomal abnormality were 12.6% and 8.3%; the rates of complete DAZ deletion were 7.7% and 11.2%, and the rates of DAZ1/DAZ2 deletion were 7.3% and 4.9% respectively, but no deletion was detected in the controls. CONCLUSION: There is a high frequency of chromosomal abnormality and DAZ gene copy deletion in patients with azoospermia and oligospermia, which suggests that chromosomal abnormality and partial and complete deletion of DAZ gene copy might be important genetic causes of Chinese male infertility.

China↗
PubMed2005

[Genomic analysis of a familial clustering of chronic hepatitis B patients].

OBJECTIVE: To investigate the peripheral blood monocyte (PBMC) gene expression profile in a familial clustering of patients with chronic hepatitis B (CHB). METHODS: cRNA prepared from PBMC in a family with 5 CHB patients and 4 normal controls was hybridized to high-density oligouncleotide arrays (HG-U133A 2.0 Human GeneChips, Affymetrix), which interrogate the expression of approximately 22,000 human ESTs. Primary image obtained from scanning was analysed with a DNT software package. Real-time PCR was employed to confirm the gene chip results. RESULTS: 55 genes out of 22,000 ESTs were identified differently. Among the 55 genes 14 showed increased expression and 41 showed decreased expression in the familial clustering CHB patients compared with those in normal controls. Most of the genes (57%) were involved in immunity, inflammation, apoptosis, signaling transduction, and cell cycle. CONCLUSION: These results suggest that the hosts with this broad range of gene expression alterations are susceptible to hepatic B infection.

Cluster Analysis↗
PubMed2004

Novel biodegradable polymers as gene carriers.

This study investigated two new biodegradable polymers as gene controlled-released coatings for gene transfer. Poly(ethylene glycol)-co-poly(D,L-lactic acid) (PELA) and poly(ethylene glycol)-co-poly(lactic acid)-co-poly(glycolic acid) random copolymer (PELGA) were synthesized and used as microspheres matrices with encapsulated plasmid pCH110. The plasmid loading efficiency, cytotoxicity, transfection efficiency and in vitro degradation and release profiles of microsphere complexes were evaluated in details. The biodegradable polymers showed high DNA loading efficiency and low cytotoxicity as gene controlled-released coatings, and the poly(ethylene glycol) (PEG) contents of polymer matrices influenced the diameter, loading efficiency and transfection efficiency of plasmid DNA within the microspheres. The average diameters of PELA and PELGA microspheres were between 0.5 and 1.5 microm, and the plasmid loading efficiency was 62 and 73% for PELA and PELGA microspheres with 10% PEG content, respectively. In vitro testing showed a gradual release profile of DNA from polymeric matrices. The polymers/DNA microspheres had high transfection efficiency and early gene expression and maintenance of gene expression level for up to 96 h, although transfection efficiency were slightly lower than that of liposome in the initial 24 h. The biodegradable polymeric materials possess potential superiority as gene carriers.

Animals↗
PubMed2004

Expression of mitogen-activated protein kinase phosphatase 1, a negative regulator of the mitogen-activated protein kinases, in rheumatoid arthritis: up-regulation by interleukin-1beta and glucocorticoids.

OBJECTIVE: Mitogen-activated protein kinases (MAPKs) are activated by proinflammatory stimuli. MAPK phosphatases (MKPs), in particular MKP-1, have been identified as endogenous negative regulators of MAPK activation. Since MAPKs are known to be important in rheumatoid arthritis (RA) synoviocyte activation, this study assessed the expression, regulation, and function of MKP-1 in RA. METHODS: MKP-1 expression was measured by Western blotting (WB) and real-time polymerase chain reaction (PCR). RA fibroblast-like synoviocytes (FLS) were treated with interleukin-1beta (IL-1beta), tumor necrosis factor alpha, fetal calf serum, and dexamethasone. Expression of MAPKs in RA FLS was analyzed by WB using phosphospecific antibodies, while IL-6 expression was assessed by real-time PCR. RESULTS: MKP-1 protein and messenger RNA were detected in cultured RA FLS. IL-1beta rapidly up-regulated MKP-1, coinciding with reciprocal down-regulation of ERK, JNK, and p38 MAPK phosphorylation. Dexamethasone rapidly and sustainably up-regulated MKP-1, and this also coincided with down-regulation of ERK, JNK, and p38 MAPK phosphorylation. In addition, dexamethasone augmented IL-1beta-induced up-regulation of MKP-1, and this was associated with inhibition of ERK, JNK, and p38 MAPK phosphorylation and IL-6 expression. Dexamethasone had no effect on the phosphorylation of upstream kinases such as MEKK-3/6. In the presence of glucocorticoid (GC) receptor antagonist RU 486, the dexamethasone-mediated up-regulation of MKP-1 was impaired. Moreover, inhibition of MKP-1 expression impaired dexamethasone-mediated inhibition of MAPK phosphorylation. CONCLUSION: This study demonstrates the expression of MKP-1 in RA FLS. Cytokine and GC regulation of MKP-1 may be important in determining the magnitude of the inflammatory response in RA that is mediated via MAPKs. The effects of GCs in RA may be mediated, in part, via GC receptor-dependent up-regulation of MKP-1.

Arthritis, Rheumatoid↗
PubMed2004

[Preparation and transfection of GFP plasmid DNA/cationic liposome complex].

OBJECTIVE: This work was directed at obtaining a better gene carrier to improve the effects of gene delivery. METHODS: Cationic liposomes made from cholesterol, lecithin and Eighteenth Amic by reverse evaporation technique were used for encapsulating plasmid DNA containing gfp gene. The DNA/liposome complexes differed in quantity of plasmid DNA. The sizes of complexes and the efficiency of encapsulation were detected. MTT assay was used to measure the cytotoxicities of complexes. The efficiency of transfection into COS1 cells was shown by observation of green fluorescent and measurement of fluorescent intensity. RESULTS: The average size of complexes was 562 nm, the encapsulating efficiency of DNA in microspheres reached 55%-65%. These DNA/Cationic liposome complexes could be transfected into mammalian cells, but they were different from each other in efficiency of transfection. The cytotoxicities of these complexes varied with the concentration of DNA in complexes, the quantities of complexes and the time of treatment by complexes. CONCLUSION: DNA/Cationic liposome complexes prepared by reverse evaporation technique could be applied in DNA delivery system.

Cations↗
PubMed2004

[Clinical application of linkage analysis for vWD family].

OBJECTIVE: To explore the application of amplified fragment length polymorphism (amp-FLP) of short tandem repeat (STR) within intron 40 of vWF gene in the gene diagnosis and genetic consulting service for von Willebrand disease (vWD). METHODS: We isolated DNA from the blood of members in 8 families with vWD, measured the relative parameters of vWD simultaneously; and amplified the fragment length polymorphism of two loci (nt1890-1990 and nt2215-2380) within intron 40 of vWF gene using PCR. The RCR products were analyzed by means of polyacrylamide gel electrophoresis (PAGE) and silver staining. RESULTS: Five types of amp-FLP were identified on nt1890-1990 and nt2215-2380 respectively. Haplotypes could be identified to link with defective vWF gene in these families. CONCLUSION: Combination of PCR and PAGE is a fast and practical method for carrying out family analysis of inherited disease; nt1980-1990 and nt2215-2380 of vWF gene are two ideal genetic labels in linkage analysis and hereditary consultation of vWD family.

Adult↗
PubMed2004

[Enhancement of the bystander effect by tanshinone IIA in HSV-tK/GCV system is related to expression of connexin 43 mRNA].

OBJECTIVE: To investigate enhancement of the bystander effect by tanshinone IIA (Tan) in HSV-tK/GCV system and the correlation with expression of connexin 43 mRNA. METHODS: The cytotoxic effect in HSV-tK/GCV in cervical carcinoma cell line ME180 (ME) and ME/TK was examined by MTT assays. Cx43 mRNA expression was detected by fluor-quantitative RT-PCR. RESULTS: Tan markedly increased sensitivity of ME/TK cells for GCV in HSV-tK/GCV system. In the presence of 2 micro g/ml GCV, compared with the absence of Tan (0 mol/L), an obvious decrease in survival rate was seen at any given mixture of ME and ME/TK cells exposed to 1.3 x 10(-9) mol/L Tan. Statistics showed significant difference (P < 0.05). However, enhancement of bystander mediated cell killing occurred only in the range of Tan concentrations used (1.3 x 10(-8), 1.3 x 10(-9) mol/L). RT-PCR showed that the ratio of relative copy number of Cx43 mRNA increased by 8.83 and 8.47-fold in ME cells exposed to 1.3 x 10(-8) and 1.3 x 10(-9) mol/L Tan, respectively. CONCLUSION: For the first time we report that in cervical carcinoma ME180 cell line, Tan possesses a remarkable enhancing role on the bystander effect in the HSV-tK/GCV system. It is associated with up-regulation of Cx43 mRNA expression.

Abietanes↗