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Feng Jin

Publications and source records attributed to Feng Jin.

At least 19 recordsLinked to original sources
PubMed2006

Association analysis of NAD(P)H:quinone oxidoreductase gene 609 C/T polymorphism with Alzheimer's disease.

Alterations of the NAD(P)H:quinone oxidoreductase (NQO1) activity are associated with Alzheimer's disease (AD). A polymorphism consisting of a single nucleotide (C-->T) change at position 609 of NQO1 influences the NQO1 activity. Therefore the NQO1 C609T polymorphism may confer susceptibility for AD developing. To test the hypothesis, we have performed an association study between the NQO1 gene polymorphism C609T and late-onset Alzheimer's disease (LOAD) in Chinese population. Totally 104 LOAD patients and 128 controls were enrolled in our data set. All subjects were genotyped for NQO1 and Apolipoprotein E (APOE). There were no significant differences in NQO1 genotype or allele frequencies between cases and controls. Likewise, with the stratification of APOE psilon4 status, no statistical difference was observed between cases and controls. Our findings suggested that this polymorphism might not represent additional genetic risk factor for LOAD. However, the present study cannot exclude NQO1 as a possible candidate for LOAD. Further study in a larger population and biological functional analysis of NQO1 gene is required to verify the role of NQO1 in LOAD.

Aged↗
PubMed2006

Role of detection of microsatellite instability in Chinese with hereditary nonpolyposis colorectal cancer or ordinary hereditary colorectal cancer.

AIM: To detect microsatellite instability (MSI) in patients with hereditary nonpolyposis colorectal cancer or ordinary hereditary colorectal cancer and to provide criteria for screening the kindreds with hereditary nonpolyposis colorectal cancer at molecular level. METHODS: MSI was detected in the specimens from 20 cases with HNPCC, 20 cases with ordinary hereditary colorectal cancer and 20 cases with sporadic colorectal cancer by means of polymerase chain reaction-single strand conformation polymorphism. RESULTS: The positive rate of MSI was 85% (17/20) in HNPCC group, 40% (8/20) in ordinary hereditary colorectal cancer group and 10% (2/20) in the sporadic colorectal cancer group respectively. The differences were significant. The mean ages of the three groups were 43.6, 52.2, and 61.8 years respectively, which increased gradually. The incidence of right hemicolon cancer was 64.7%, 37.5%, and 0% respectively, which decreased gradually and had significant difference. The expression ratio of BAT26 and BAT25 was 94.1% respectively, which was highest in the 5 gene sites studied. The incidence of poorly differentiated adenocarcinoma was 70.6% in HNPCC group among high frequency microsatellite instability (MSI-H), which was higher than the other two groups, which had 50% and 50% respectively. CONCLUSION: The incidence of MSI-H is higher in HNPCC group. The detection of MSI is simple and economical and has high correlation with the clinicopathologic feature of HNPCC and can be used as a screening method to detect the germ line mutation of the mismatch repair gene.

Adult↗
PubMed2006

Identification of novel functional variants of the melanocortin 1 receptor gene originated from Asians.

Human melanocortin 1 receptor (MC1R) is a seven transmembrane G-coupled protein receptor that upregulates the cAMP pathway. Several functional variants of MC1R that show an impaired ability to activate the cAMP pathway are strongly associated with fair skin and red hair in Europeans and European descendants. The sequence variations of the MC1R gene were repeatedly investigated against worldwide populations; however, there was no evidence that functional variant of MC1R exists in non-European descendants. We report the presence of novel functional variants of MC1R with Asian origins. Three novel variants of MC1R, Phe147Delta, Thr157Ile, and Pro159Thr, were identified in our screening for the sequence variations of the MC1R gene against 995 individuals from 30 Asian and Oceanian populations; there was a single case for the Pro159Thr variant allele and two instances of Phe147Delta and Thr157Ile variant alleles. Our pharmacological assay revealed that Phe147Delta, Thr157Ile, and Pro159Thr variant showed similar or more dramatically impaired activities in comparison with Arg151Cys, which is a major functional variant of MC1R in Europeans. These functional variant alleles were geographically localized in relatively high latitudes, which suggest that the adaptation to ambient UV light intensity may play an important role in shaping the geographical distribution of MC1R alleles in Asia and Oceania.

Animals↗
PubMed2006

Pharmacokinetic and pharmacodynamic effects of high-dose monoclonal antibody therapy in a rat model of immune thrombocytopenia.

Intravenous administration of pooled, polyvalent human immunoglobulin (IVIG) has been used for over 20 years as a therapy for immune thrombocytopenia (ITP). IVIG is available in limited quantities, and clinical preparations have been associated with the transfer of human pathogens. We have proposed that high-dose monoclonal antibody may be used in lieu of IVIG to achieve beneficial effects in the treatment of ITP. The current study investigates the effects of high-dose monoclonal antibody therapy in a rat model of ITP. Hybridoma cells secreting a murine monoclonal antiplatelet antibody (7E3) and murine monoclonal anti-methotrexate IgG (AMI) were grown in serum-free media. Next, 7E3, 8 mg kg(-1), was administered intravenously to rats following pretreatment with saline or AMI (1 g kg(-1) IV). AMI and 7E3 plasma concentrations were determined via enzyme-linked immunosorbent assay, and platelet count was determined with a Cell-Dyne hematology analyzer. Severe, transient thrombocytopenia was induced by 7E3. Platelet counts dropped to approximately 8% of initial values within 1 hour after 7E3 administration. AMI pretreatment dramatically affected 7E3-induced thrombocytopenia, significantly altering the time course of thrombocytopenia (P < .05) and significantly decreasing the severity of 7E3-induced thrombocytopenia (ie, following AMI pretreatment, nadir platelet count was greater than 8-fold that of the control group, P < .05). In addition, AMI pretreatment induced a 57% increase in 7E3 clearance (1.13 +/- 0.13 mL h(-1) kg(-1) vs 0.72 +/- 0.08 mL h(-1) kg(-1), P < .05). Consequently, high-dose monoclonal antibody therapy attenuated thrombocytopenia and produced a moderate increase in the clearance of antiplatelet antibodies in a rat model of ITP.

Animals↗
PubMed2006

[Myopia and genetics].

The physiological manifestation of myopia is error of refraction. The incidence of myopia in Asian population is increasing much more rapidly compared with several decades ago. Most of the people in the relatively developed Chinese cities are developing or have developed myopia. Recently, researches reported six loci related to myopia. Viewing from the modern civilization and development of China, the sharp increase of the size of the population with myopia and the unbalanced change could not be explained only by gene mutation or any model of Mendelian inheritance. The comparison of the disparity of the economic and educational levels between in urban and rural areas showed that the onset of myopia might be influenced by both environmental and genetic factors. Special attention should be paid to myopia now to prevent severe physical problem in the Chinese urban population.

China↗
PubMed2006

[Level of urocortin mRNA during labor and effect of urocortin on myometrial contractility in vitro].

OBJECTIVE: To examine the expression of urocortin mRNA during labor and the effect of urocortin on myometrial contractility, and to investigate its role in the onset and progress of labor. METHODS: (1) Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), using beta-actin as internal standard was applied to determine the levels of urocortin mRNA in human placenta and myometrium from the group of cesarean section before (10 cases) and during (10 cases in latent phase and 10 cases in active phase) labor. (2) The isolated myometrial strips of pregnant women (n = 24) were prepared. The effects of urocortin with or without prostaglandin F(2alpha) (PGF(2alpha)) and oxytocin on myometrial contractility were evaluated by areas under the curve. RESULTS: (1) Semi-quantitative RT-PCR showed that the expression level of urocortin mRNA in placenta and myometrium after the onset of labor were higher than before labor (1.23 +/- 0.52, 1.32 +/- 0.22; 0.83 +/- 0.38, 0.94 +/- 0.13, respectively, P < 0.05). (2) Urocortin itself did not affect myometrial tension development at all concentrations tested, but it markedly increased PGF(2alpha)-induced myometrial contractility. The average area under the curve of controls was (2.12 +/- 0.15) cm(2) and of study strips was (3.90 +/- 0.33) cm(2) (P < 0.05); urocortin did not increase the myometrial response to oxytocin compared with controls (P > 0.05). CONCLUSION: The study indicates urocortin may indirectly modulate myometrial contractility during labor.

Adult↗
PubMed2005

Phylogenetic relationship of the populations within and around Japan using 105 short tandem repeat polymorphic loci.

We have analyzed 105 autosomal polymorphic short tandem repeat (STR) loci for nine East and South-eastern Asian populations (two Japanese, five Han Chinese, Thai, and Burmese populations) and a Caucasian population using a multiplex PCR typing system. All the STR loci are genomewide tetranucleotide repeat markers of which the total number of observed alleles and the observed heterozygosity were 756 and 0.743, respectively, for Japanese populations. Phylogenetic analysis for these allele frequency data suggested that the Japanese populations are more closely related with southern Chinese populations than central and/or northern ones. STRUCTURE program analysis revealed the almost clearly divided and accountable population structure at K=2-6, that the two Japanese populations always formed one group separated from the other populations and never belong to different groups at K> or =3. Furthermore, our new allele frequency data for 91 loci were analyzed with those for 52 worldwide populations published by previous studies. Phylogenetic and multidimensional scaling (MDS) analyses indicated that Asian populations with large population size (six Han Chinese, three Japanese, two Southeast Asia) formed one distinct cluster and are closer to each other than other ethnic minorities in east and Southeast Asia. This pattern may be the caviar of comparing populations with greatly differing population sizes when STR loci were analyzed.

Asia, Southeastern↗
PubMed2005

Founder SVA retrotransposal insertion in Fukuyama-type congenital muscular dystrophy and its origin in Japanese and Northeast Asian populations.

Fukuyama-type congenital muscular dystrophy (FCMD), one of the most common autosomal recessive disorders in Japan, is characterized by congenital muscular dystrophy associated with brain malformation due to a defect in neuronal migration. Previously, we identified the gene responsible for FCMD, which encodes the fukutin protein. Most FCMD-bearing chromosomes (87%) are derived from a single ancestral founder, who lived 2,000-2,500 years ago and whose mutation consisted of a 3-kb retrotransposal insertion in the 3' non-coding region of the fukutin gene. Here we show, through detailed sequence analysis, that the founder insertion is derived from the SINE-VNTR-Alu (SVA) retroposon. To enable rapid detection of this insertion, we have developed a PCR-based diagnostic method that uses three primers simultaneously. We used this method to investigate the distribution and origin of the founder insertion, screening a total of 4,718 control DNA samples from Japanese and other Northeast Asian populations. Fifteen founder chromosomes were detected among 2,814 Japanese individuals. Heterozygous carriers were found in various regions throughout Japan, with an averaged ratio of 1 in 188. In Korean populations, we detected one carrier in 935 individuals. However, we were unable to detect any heterozygous alleles in 203 Mongolians and 766 Mainland Chinese populations. These data largely rule out the possibility that a single ancestor bearing an insertion-chromosome immigrated to Japan from Korea or Mainland China and appear to confirm that FCMD carriers are rare outside of Japan.

Asia↗
PubMed2005

Removal of SO2 from O2-containing flue gas by activated carbon fiber (ACF) impregnated with NH3.

Adsorption of SO(2) from the O(2)-containing flue gas by granular activated carbons (GACs) and activated carbon fibers (ACFs) impregnated with NH(3) was studied in this technical note. Experimental results showed that the ACFs were high-quality adsorbents due to their unique textural properties. In the presence of moisture, the desulphurization efficiency for the ACFs was improved significantly due to the formation of sulfuric acid. After NH(3) impregnation of ACF samples, nitrogen-containing functional groups (pyridyl C(5)H(4)N- and pyrrolyl C(4)H(4)N-) were detected on the sample surface by using an X-ray photoelectron spectrometer. These functional groups accounted for the enhanced SO(2) adsorption via chemisorption and/or catalytic oxidization.

Adsorption↗
PubMed2005

Investigation of scattering of elastic waves by cylinders in 1-3 piezocomposites.

The scattering behavior of P-waves in piezoelectric composites with 1-3 connectivity is studied. The method of wave function expansion is adopted for the theoretical derivations. Analytical expressions are obtained for the distributions of mechanical displacement in z-direction along the circumferences of piezoelectric cylinders. These solutions are used to study the influence of each element of the stiffness matrix and the piezoelectric matrix on the various resonant modes of vibration. Numerical results obtained indicate that perturbations of the elements c44 and e15 significantly affect resonant frequencies and amplitudes, perturbations of c11 and c12 have pronounced effects on resonant modes of high frequencies also. However, the resonant modes are not so sensitive to the perturbations of c13, e31 and e33. The dynamic characteristics of 1-3 connectivity piezoelectric composites exposed here are meaningful for the design and manufacture of sensor/actuator elements by this kind of composites as well as the on-line health monitoring of the mechanical properties variations of the composites itself.

Ceramics↗
PubMed2005

[The study of the minimum number of examined lymph nodes for the TNM classification of gastric cancer].

OBJECTIVE: To determine the minimum number of lymph nodes that should be examined for the UICC/AJCC TNM classification of gastric cancer. METHODS: The clinical and pathological data of four hundred and thirty-six patients underwent curative resection for gastric cancer were analyzed by Chi-square and Student-Newman-Keuls test. RESULTS: The pN0 patients with 1 to 4, 5 to 9 examined nodes showed significantly lower survival rate than those with 10 to 14, 15 or more examined nodes (P < 0.05), and the patients with 10 to 14 examined nodes had as good a prognosis as those with 15 or more examined nodes. In the pN1, pN2 categories, the patients with 1 to 4, 5 to 9 and 10 to 14 examined nodes tended toward significantly lower survival rates than those with 15 or more examined nodes (P < 0.05). Among the patients who were classified as stage II, the survival rate of those with 10 to 19 examined nodes was significantly lower than that with 20 or more examined nodes. Among the patients classified as stage III, those with 5 to 9, 10 to 19 and 20 to 29 examined nodes had significantly lower survival rates than those with 30 or more examined nodes (P < 0.05). CONCLUSIONS: The number of lymph nodes examined has significant prognostic impact within each pN category of gastric carcinoma. The minimum number of lymph nodes to examine in order to determine pN0 classification can be reduced from 15 to 10. For tumor with lymph node metastasis, the minimum number should be 15. In stage II, 20 or more nodes should be examined, and in stage III and IV 30 or more.

Adult↗
PubMed2005

Molecular cloning and characterization of a novel human C4orf13 gene, tentatively a member of the sodium bile acid cotransporter family.

By large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a novel human cDNA (C4orf13). This cDNA is 2706 bp in length, encoding a 340-amino-acid polypeptide that contains a typical SBF (sodium bile acid cotransporter family) domain and ten possible transmembrane segments. The putative protein C4orf13 shows high similarity with its orthologs in Mus musculus and Xenopus laevis. Human C4orf13 is mapped to chromosome 4q31.2 and contains 12 exons. RT-PCR analysis shows that human C4orf13 is widely expressed in human tissues, and the expression levels in liver and lung are relatively high, expression levels in placenta, kidney, spleen, and thymus are moderate, low levels of expression are detected in heart, prostate, and testis.

Amino Acid Sequence↗
PubMed2005

Mechanisms of intravenous immunoglobulin action in immune thrombocytopenic purpura.

The use of high-dose intravenous gamma immunoglobulin (IVIG) for the treatment of immune thrombocytopenic purpura (ITP) was first reported more than two decades ago. After the therapeutic benefit of IVIG was established in ITP, it was then successfully used to treat many other autoimmune diseases. Although a complete definition of the mechanism of IVIG action is still lacking, extensive research suggests that IVIG may achieve its therapeutic effects through multiple mechanisms. IVIG exerts immunomodulatory effects that may include antiidiotypic neutralization of antiplatelet antibodies, stimulation of Fcgamma receptor IIB expression, and inhibition of Fcgamma receptor-mediated platelet destruction. Recent work suggests that a large fraction of the benefit provided by IVIG may be the result of competitive inhibition of neonatal Fc receptor (FcRn) and IVIG-induced acceleration of antiplatelet antibody elimination. This review provides an overview and critical discussion of mechanisms that may be responsible of IVIG effects in ITP.

Animals↗
PubMed2005

Genetic association of BACE1 gene polymorphism C786G with late-onset Alzheimer's disease in Chinese.

Beta-amyloid (Abeta) peptides are derived from the endoproteolytic processing of amyloid precursor protein (APP) and play a key role in the pathogenesis of Alzheimer's disease (AD). Beta-site APP-cleaving enzyme 1 ([BACE1] also known as beta-secretase) is responsible for cleaving APP to generate neurotoxic Abeta peptides in patients with AD. The BACE1 gene is located on chromosome 11q23.3, near the recently identified region with increased lod scores for AD. The biological functional and genetic association studies indicated that the BACE1 gene might be a genetic risk factor for late-onset Alzheimer's disease (LOAD). To investigate an association between the BACE1 C786G polymorphism and sporadic LOAD in Chinese, we examined 105 LOAD patients and 130 healthy controls. Our results showed higher frequency of the 786G-allele in LOAD patients (38.6%) than that in controls (28.5%), and a statistical significance was observed for an association of the G-allele with LOAD (odds ratio [OR] = 1.58, 95% confidence interval [CI] 1.07-2.23, p = 0.02). We also found a synergetic interaction between the G-allele and apolipoprotein E allele 4 (APOE e4) status on the risk of LOAD (OR = 1.91, 95% CI 1.23-2.95, p = 0.003). These results suggest that BACE1 gene polymorphism C786G might act as an APOE epsilon4 allele-dependent risk factor for developing LOAD in Chinese.

Adult↗
PubMed2005

Association of MTHFR gene polymorphism C677T with susceptibility to late-onset Alzheimer's disease.

Increased total plasma homocysteine (t-Hcy) levels are found to be associated with Alzheimer's disease (AD). Because the methylenetetrahydrofolate reductase (MTHFR) gene encodes a key enzyme that influences the metabolism of homocysteine, it has been considered as a possible genetic risk factor for AD. Although the MTHFR gene C677T polymorphism has a significant impact on reducing enzyme activity and increasing t-Hcy concentrations, the association between the C677T polymorphism and AD remains inconclusive. To determine whether the MTHFR gene C677T polymorphism contributes to the risk for late-onset AD (LOAD) in Chinese, we have investigated 104 sporadic LOAD patients and 130 healthy controls. The strong associations of the TT genotype and T-allele with LOAD (p 0.001, OR 5.73 95% CI 1.85-17.72, and p 0.002, OR 1.89 95% CI 1.25-2.86) were found. After stratifying by apolipoprotein E allele 4 (APOE epsilon4) status, increased LOAD risks associated with the TT genotype only in the APOE epsilon4 noncarriers (chi2=8.92, df=1, p=0.003) and with the T-allele in either group (chi2=5.18, df=1, p=0.023 and chi2=5.53, df=1, p=0.019) were seen. These results suggest that as an APOE epsilon4 allele-dependent risk factor, the MTHFR gene C677T polymorphism is involved in developing LOAD in Chinese.

Aged↗
PubMed2005

[Progress in the molecular mechanisms of nuclear coactivator PGC-1].

Peroxisome proliferators-activated receptor-gamma coactivator-1 is broadly involved in several key cellular pathways including mitochondrial biogenesis, hepatic gluconeogenesis via interacting with many transcription factors, which is highly valuable to maintain the energy balance of organisms. This review especially focuses on the recent progress in the molecular docking, histone acetylation, RNA processing basing on the structure of PGC-1 gene and amino acid sequence. Besides, the prospect of PGC-1 in applications of metabolic syndromes has been discussed also.

Acetylation↗
PubMed2005

[Dynamic observation on serum sialic acid in nasopharyngeal carcinoma patients].

OBJECTIVE: To discuss the diagnostic value and possibility to be a dynamic monitoring index of serum sialic acid (SA) in nasopharyngeal carcinoma (NPC) patients. METHODS: Serum SA and Epstein-Barr virus-viral coat antigens-IgA (EBV-VCA-IgA) were detected in 50 cases of NPC before treatment, after clinical recovery and recurrence. Healthy adult and patients of benign lesions of head and neck were also detected as controls. RESULTS: SA and EBV-VCA-IgA were positively related significantly in different periods of NPC patients. SA was significantly varied dynamically before and after radiation and chemical therapy in NPC patients. The positive rate of SA was 94.0% (47/50) before treatment, 2.0% (1/50) after clinical recovery, 96.2% (25/26) in recurrent patient and 4.2% (1/24) in patients without recurrence. The reaction of EBV-VCA-IgA was slow and its corresponding positive rates were 90.0%, 90.0%, 84.6%, 0% and 75.0% respectively. The sensitivity of SA in pre-treated NPC patients was 94.0%, higher than EBV-VCA-IgA (90.0%). The specificity of serum SA was 93.0% in this series, lower than that of EBV-VCA-IgA (96.0%). CONCLUSION: Dynamic detections of serum SA combined with EBV-VCA-IgA can be used as indices in dictating the changes in NPC patients and screening of high-risk population, judgment of curative effect and prediction of prognosis.

Adult↗