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Biomedical subjects

L He

Publications and source records attributed to L He.

At least 19 recordsLinked to original sources
PubMed2004

Insulin-degrading enzyme and Alzheimer disease: a genetic association study in the Han Chinese.

BACKGROUND: The gene for insulin-degrading enzyme (IDE) represents a strong positional and biologic candidate for late-onset Alzheimer disease (LOAD) susceptibility. IDE is located on chromosome 10q23.3 close to a region of linkage for LOAD. In addition, many studies have identified a possible role of IDE in the degradation of amyloid beta-protein and the intracellular amyloid precursor protein (APP) domain released by gamma-secretase processing. OBJECTIVE: To examine the association of IDE with AD in the Han Chinese. METHODS: Four IDE polymorphisms (three in 5'-untranslated region and one in intron 21) were analyzed, using a population of 210 patients with LOAD and 200 control subjects well matched for age, sex, and ethnic background. RESULTS: Among the four polymorphisms studied, only the C allele of single-nucleotide polymorphism (SNP) IDE2 showed association with AD (p = 0.005). Stratification of the data by APOE epsilon4 status indicated that the association between IDE2 and AD was confined to APOE epsilon4 carriers only. No association was found between all variants studied and AD within APOE epsilon4-negative subjects. The global haplotype frequencies showed significant differences between AD patients and control subjects. Furthermore, overrepresentation of GCTG haplotype in the AD group was found. It may be a risk haplotype for AD. CONCLUSIONS: These results suggest a possible synergic interaction between IDE and APOE epsilon4 in the risk to develop late-onset sporadic AD. IDE might modify the effect of the APOE epsilon4 risk factor in the Han Chinese population.

Age of Onset↗
PubMed2004

Acupuncture for Bell's palsy.

BACKGROUND: Bell's palsy or idiopathic facial palsy is an acute facial paralysis due to inflammation of the facial nerve. A number of studies published in China have suggested acupuncture is beneficial for facial palsy. OBJECTIVES: The objective of this review was to examine the efficacy of acupuncture in hastening recovery and reducing long-term morbidity from Bell's palsy. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Register, MEDLINE (January 1966 to December 2002), EMBASE (January 1980 to December 2002), LILACS (from January 1982 to December 2002) and the Chinese Biomedical Retrieval System (January 1978 to December 2002) for randomised controlled trials using 'Bell's palsy' and its synonyms, 'idiopathic facial paralysis' or 'facial palsy' as well as search terms including 'acupuncture'. Chinese journals in which we thought we might find randomised controlled trials or controlled clinical trials relevant to our study were handsearched. We reviewed the bibliographies of the randomised trials and contacted the authors and known experts in the field to identify additional published or unpublished data. SELECTION CRITERIA: We included all randomised or quasi-randomised controlled trials involving acupuncture in the treatment of Bell's palsy irrespective of any language restrictions. DATA COLLECTION AND ANALYSIS: Two reviewers identified potential articles from the literature search and extracted data independently using a data extraction form. The assessment of methodological quality included allocation concealment, patient blinding, differences at baseline of the experimental groups and completeness of follow-up. Two reviewers assessed quality independently. All disagreements were resolved by discussion between the reviewers. MAIN RESULTS: Three studies including a total of 238 patients met the inclusion criteria. Two of them used acupuncture while the third used acupuncture combined with drugs. No trials reported on the outcomes specified for this review. Three included studies showed that the therapeutic effect of acupuncture alone was superior to that of medication or that acupuncture combined with medication was better than medication alone. Harmful side-effects were not reported in any of the trials. Flaws in study design or reporting (particularly uncertain allocation concealment and substantial loss to follow-up) and clinical differences between trials prevented a meta-analysis. REVIEWER'S CONCLUSIONS: The quality of the included trials was inadequate to allow any conclusion about the efficacy of acupuncture. More research with high quality trials is needed.

Acupuncture Therapy↗
PubMed2004

Enhancement of suicidal DNA vaccine potency by delaying suicidal DNA-induced cell death.

DNA-based alphaviral RNA replicon vectors, also called suicidal DNA vectors, alleviate the concerns of integration or transformation related to conventional DNA vectors since suicidal DNA vectors eventually cause apoptosis of transfected cells. However, the expression of inserted genes in these vectors is transient and the potency of suicidal DNA vaccines may be compromised because of apoptotic cell death. Therefore, to enhance the immune response to the human papillomavirus type 16 (HPV-16) E7 antigen, we generated a DNA-based Semliki Forest virus vector, pSCA1, encoding E7 fused with BCL-xL, an antiapoptotic member of the BCL-2 family. Our results indicated that pSCA1 encoding E7/BCL-xL fusion protein delayed cell death in the pSCA1-transfected dendritic cell line and generated significantly higher E7-specific CD8(+) T-cell-mediated immune responses and better antitumor effects than pSCA1 encoding wild-type E7 gene in vaccinated mice. The antiapoptotic function of BCL-xL is important for the enhancement of antigen-specific CD8(+) T-cell responses in vaccinated mice, because a point mutant of BCL-xL lacking antiapoptotic function was ineffective. These results suggest that strategies to delay suicidal DNA-induced cell death using antiapoptotic proteins may greatly enhance the potency of suicidal DNA.

Animals↗
PubMed2004

Comparison of HPV DNA vaccines employing intracellular targeting strategies.

Intradermal vaccination via gene gun efficiently delivers DNA vaccines into dendritic cells (DCs) of the skin, resulting in the activation and priming of antigen-specific T cells in vivo. In the context of DNA vaccines, we previously used the gene gun approach to test several intracellular targeting strategies that are able to route a model antigen, such as the human papillomavirus type-16 (HPV-16) E7, to desired subcellular compartments in order to enhance antigen processing and presentation to T cells. These strategies include the use of the sorting signal of lysosome-associated membrane protein (LAMP-1), Mycobacterium tuberculosis heat-shock protein 70 (HSP70), calreticulin (CRT) and the translocation domain (dII) of Pseudomonas aeruginosa exotoxin A (ETA). Vaccination with DNA vaccines encoding E7 antigen linked to any of these molecules all led to a significant enhancement of E7-specific CD8(+) T-cell immune responses and strong antitumor effects against an E7-expressing tumor, TC-1. However, we were interested in identifying the most potent DNA vaccine for our future clinical trials. Thus, we performed a series of experiments to directly compare the potency of the various DNA vaccines. Among the DNA vaccines we tested, we found that vaccination with pcDNA3-CRT/E7 generated the highest number of E7-specific CD8(+) T cells and potent long-term protection and treatment effects against E7-expressing tumors in mice. Interestingly, we observed that pcDNA3-CRT/E7 is also capable of protecting against an E7-expressing tumor with downregulated MHC class I expression, a common feature associated with most HPV-associated cervical cancers. Our data suggest that the DNA vaccine linking CRT to E7 (CRT/E7) may be a suitable candidate for human trials for the control of HPV infections and HPV-associated lesions.

Animals↗
PubMed2004

Association of SNPs and haplotypes in GABAA receptor beta2 gene with schizophrenia.

Disturbances in GABAergic system have been observed in schizophrenics. In the present study, population association analysis was performed on 19 SNPs in the alpha(1), beta(2), gamma(2), epsilon and pi subunit genes of GABA(A) receptor. Five SNPs in GABRB2, namely B2I7G1584T, rs1816071, rs194072, rs252944 and rs187269, were found to be significantly associated, and their haplotypes in linkage disequilibrium, with schizophrenia. This represents the first report on any disease association of SNPs in the human GABA(A) receptor genes, and focuses attention on the GABAergic hypothesis of schizophrenia etiology.

Amino Acid Sequence↗
PubMed2004

Positive association of the DIO2 (deiodinase type 2) gene with mental retardation in the iodine-deficient areas of China.

BACKGROUND: Iodine deficiency is the commonest cause of preventable mental retardation (MR) worldwide. However, in iodine-deficient areas not everyone is affected and familial aggregation is common. This suggests that genetic factors may also contribute. Thyroid hormone (TH) plays an important role in fetal and early postnatal brain development. The pro-hormone T4 (3,3',5,5'-triiodothyronine) is converted in the brain to its active form, T3, or its inactive metabolite, reverse T3, mainly by the action of deiodinase type 2 (DIO2). METHODS: To investigate the potential genetic contribution of the DIO2 gene, we performed a case-control association study using three common SNPs in the gene (rs225014, rs225012, and rs225010) that were in strong linkage disequilibrium with each other. RESULTS: Single marker analysis showed a positive association of MR with rs225012 and rs225010. Particularly with rs255012 [corrected], CC [corrected] genotype frequency was significantly higher in MR cases than in controls (chi squared [corrected] = 9.18, p = 0.00246). When we compared the distributions of common haplotypes, we also found significant differences between mental retardation and controls in the haplotype combination of rs225012 and rs225010 (chi2 = 15.04, df 2, global p = 0.000549). This association remained significant after Bonferroni correction (p = 0.0016470). CONCLUSION: We conclude that allelic variation in the DIO2 gene may affect the amount of T3 available and in an iodine-deficient environment may partly determine overall risk of MR.

Adolescent↗
PubMed2003

Novel germanium-based magnetic semiconductors.

Epitaxial synthesis and properties of novel Co and Mn-doped Ge magnetic semiconductors were studied. Epitaxial growth of high quality films with high doping concentrations has been stabilized by the use of two dopants. The magnetic and transport properties of the system exhibit high T(C) and large magnetoresistance effects that can be controlled systematically by the doping concentration. The maximum T(C) achieved in the semiconducting materials is approximately 270 K at a composition of Co0.12Mn0.03Ge0.85.

Journal Article↗
PubMed2003

Apolipoprotein E -491 promoter polymorphism is an independent risk factor for Alzheimer's disease in the Chinese population.

Polymorphisms at positions -491, -427 and -219 in the promoter region of the Apolipoprotein E APOE gene have been variously reported to confer an increased risk of developing Alzheimer's disease (AD) independent of the effect of epsilon 2, 3 or 4 alleles in exon 4. In order to assess APOE promoter polymorphisms as independent risk factors in AD we have compared results in 183 definite or probable AD cases with 133 controls. We assayed markers at sites -491, -427, -219, and +113 in APOE gene and a polymorphic Hha1 site in the nearby APOC1 gene. We found that APOE promoter polymorphisms and APOC1 insertion alleles were significantly associated with AD. However, after stratification for epsilon 4 allele, only the A allele at -491 in APOE remained significantly associated with AD. The effects of the other markers depended almost entirely upon linkage disequilibrium with epsilon 4 allele, and only trends remained when cases and controls were stratified for the presence or absence of epsilon 4 allele. This occurred irrespective of whether markers were examined separately or together as haplotypes. So in the Chinese population only APOE -491 promoter alleles confer significant risk of AD independent of epsilon 4 status.

Aged↗
PubMed2003

Proteomic analysis of the cerebrospinal fluid of patients with schizophrenia.

We applied proteomics technologies to analyze the cerebrospinal fluid of patients with schizophrenia. Such an analysis can result in the identification of proteins, which may play a role in the disease progress and thus lead to the discovery of clues of the etiology of schizophrenia. Cerebrospinal fluid from patients and controls was analyzed by two-dimensional gels and the proteins were identified by matrix-assisted laser desorption ionization mass spectrometry (MS) in the MS and MS/MS mode. 54 different gene products were identified, which were mainly plasma proteins. The level of apolipoprotein A-IV was significantly decreased in the schizophrenic patients compared to that in the controls. Little is known about the function of this apolipoprotein in the central nervous system. The levels of certain other proteins, like haptoglobin, fibrinogen, complement component 3, and Gc-globulin, were altered in the disease group as well, however, the changes did not reach a statistical significance.

Apolipoproteins A↗
PubMed2003

CD8+ T cells, NK cells and IFN-gamma are important for control of tumor with downregulated MHC class I expression by DNA vaccination.

One of the major hurdles facing cancer immunotherapy is that cancers may downregulate expression of MHC class I molecules. The development of a suitable tumor model with downregulated MHC class I expression is critical for designing vaccines and immunotherapeutic strategies to control such tumors. We developed an E7-expressing murine tumor model with downregulated MHC class I expression, TC-1 P3 (A15). Using this model, we tested DNA and vaccinia vaccines for their ability to control tumors with downregulated MHC class I expression. We found that vaccination with DNA encoding E7 linked to Mycobacterial heat shock protein 70 (HSP70) generated a significant antitumor effect against TC-1 P3 (A15), while vaccination with E7/HSP70 vaccinia did not generate an appreciable antitumor effect. Lymphocyte depletion experiments revealed that both CD8+ T cells and NK cells were essential for the antitumor effect generated by E7/HSP70 DNA against TC-1 P3 (A15). Furthermore, tumor protection experiments using IFN-gamma knockout mice revealed that IFN-gamma was essential for the antitumor effect generated by E7/HSP70 DNA against TC-1 P3 (A15). Our results demonstrate that vaccination with E7/HSP70 DNA results in a significant antitumor effect against a neoplasm with downregulated MHC class I expression and the importance of CD8+ T cells, NK cells, and IFN-gamma in generating this antitumor effect.

Animals↗
PubMed2003

Somatic mitochondrial DNA mutations in adult-onset leukaemia.

Mitochondrial genome instability has recently been demonstrated in a wide variety of human tumours and is implicated in the development of the myelodysplastic syndromes, a heterogeneous group of haematological disorders with an increased risk of malignant transformation. We therefore investigated the incidence of somatic mitochondrial DNA (mtDNA) mutations in patients with adult-onset leukaemia. We sequenced the entire mitochondrial genome from both normal tissue (buccal epithelial cells) and the leukaemia from 24 patients with adult-onset leukaemia. Somatic mtDNA mutation was present in nine individuals ( approximately 40%) and in each case the tumour genome differed from the normal genome sequence by a single sequence change. Using PCR-RFLP analysis and real-time PCR, we have studied in detail the mutation present in one patient with acute lymphatic leukaemia, demonstrating that the mutation is associated specifically with the leukaemia.

Adolescent↗