Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and N-linolenoyl-L-glutamine, originally identified in the regurgitant of Spodoptera exigua, induce damaged corn leaves to release volatile compounds which enable parasitic wasps to locate host caterpillars. Here we demonstrate the in vitro biosynthesis of volicitin for the first time by using gut tissues of Spodoptera litura larvae, as well as N-linolenoyl-L-glutamine. When crop, midgut tissues, peritrophic membrane and gut contents isolated from S.
View Article and Find Full Text PDFCEM15 (or APOBEC3G) has recently been identified as an inhibitor of human immunodeficiency virus type 1 (HIV-1) replication in vitro. To evaluate the impact of its genetic variations on the progression of acquired immunodeficiency syndrome (AIDS), we have performed an extensive genetic analysis of CEM15. We have sequenced CEM15 in a cohort of 327 HIV-1-seropositive patients with extreme disease progression phenotypes--either slow progression or rapid progression--and in 446 healthy control subjects, all of white descent.
View Article and Find Full Text PDFPeriod (Per) genes are involved in regulation of the circadian clock and are thought to modulate several brain functions. We demonstrate that Per2(Brdm1) mutant mice, which have a deletion in the PAS domain of the Per2 protein, show alterations in the glutamatergic system. Lowered expression of the glutamate transporter Eaat1 is observed in these animals, leading to reduced uptake of glutamate by astrocytes.
View Article and Find Full Text PDFComplete reversal of diastereoselectivity was observed in the SmI(2)-promoted ketyl-olefin coupling cyclizations of the hydroxy ketone or aldehyde and its acetate. For example, the stereodivergent synthesis of the epimeric five-membered-ring alcohols 2 and 4 has been accomplished through the SmI(2)-induced ketyl-olefin coupling cyclizations of the delta-hydroxy ketone 1 and delta-acetoxy ketone 3.
View Article and Find Full Text PDFJ Bioinform Comput Biol
July 2003
The single nucleotide polymorphism (SNP) is the difference of the DNA sequence between individuals and provides abundant information about genetic variation. Large scale discovery of high frequency SNPs is being undertaken using various methods. However, the publicly available SNP data sometimes need to be verified.
View Article and Find Full Text PDFOat leaves produce phytoalexins, avenanthramides, in response to infection by pathogens or treatment with elicitors. The metabolism of avenanthramides was investigated using low molecular weight, partially deacetylated chitin as an elicitor. When oat leaf segments are floated on the elicitor solution, avenanthramides accumulate in the solution.
View Article and Find Full Text PDFBackground: We have demonstrated that carbohydrates in Cry j 1, the major allergen of Cryptomeria japonica pollen, play a major role in promoting Cry j 1-specific Th2 response. However, little is known as to whether the carbohydrates directly participate in allergic responses.
Objective: We sought to determine whether Cry j 1-related oligosaccharides function as IgE and/or T cell epitopes.
A method for quantifying two toxic glycoalkaloids, alpha-solanine and alpha-chaconine, in potato (Solanum tuberosum) tuber tissue was developed using HPLC-electrospray ionisation (ESI)/MS. Potato samples were extracted with 5% aqueous acetic acid, and the extracts were subjected directly to HPLC-ESI/MS after filtration. By determining the intensities of the protonated molecules of alpha-solanine (m/z 868) and alpha-chaconine (m/z 852) using selected ion monitoring (positive ion mode), a sensitive assay was attained with detection limits of 38 and 14 ppb for the two glycoalkaloids, respectively.
View Article and Find Full Text PDFApoptosis has been suggested as a major mechanism for the CD4(+) T-lymphocyte depletion observed in patients infected with human immunodeficiency virus 1 (HIV-1). To evaluate the impact of genetic variations to apoptosis during progression of acquired immunodeficiency syndrome (AIDS), we have performed an extensive genetic analysis of Fas and Fas ligand ( FasL) genes. The coding regions and promoters of these genes were resequenced in a cohort of 212 HIV-1-seropositive patients presenting extreme disease phenotypes and 155 healthy controls of Caucasian origin.
View Article and Find Full Text PDFAnti-TSH receptor antibodies (TRAbs) have been known to be involved in Graves' disease and primary hypothyroidism. We previously isolated and reconstituted immunoglobulin (Ig) genes of Epstein-Barr virus-transformed B cell clones producing monoclonal TRAbs obtained from Graves' patients. In the present study, we performed a similar experiment using a B cell clone, 32A-5, derived from a patient with primary hypothyroidism.
View Article and Find Full Text PDFInterferon-tau (IFNtau) is a protein secreted from the embryonic trophectoderm of ruminant ungulates during peri-implantation period. This protein acts on the uterine endometrium, which indirectly maintains corpus luteum function, and is therefore considered essential for the process of maternal recognition of pregnancy. Transcriptional regulation of IFNtau genes had been examined using human choriocarcinoma cell lines, JEG-3 or JAR, however, molecular mechanisms by which cell and term specific IFNtau expression are regulated have not been elucidated.
View Article and Find Full Text PDF[reaction: see text] A general, efficient, and experimentally simple method for generating medium rings utilizing the SmI(2)-mediated Barbier-type coupling has been developed. Various eight- and nine-membered carbocycles and heterocycles are assembled with high efficiency via this protocol. Amazingly, the process does not require high-dilution conditions and almost quantitative yields of the frequently inaccessible medium-sized rings are obtained.
View Article and Find Full Text PDFPolymorphisms of Th1-Th2 cytokine genes have previously been implicated in the rate of progression to AIDS in seropositive patients. To evaluate further the impact of these genes in the development of AIDS, we have performed an extensive genetic analysis of IL2, IL4, IL6, IL10, IL12p35 and p40, IL13 and IFNgamma. The coding regions and promoters of these genes were sequenced in a Caucasian cohort of 337 HIV-1 seropositive extreme patients (the GRIV cohort) consisting of patients with slow progression and rapid progression, and up to 470 healthy controls.
View Article and Find Full Text PDFHypogonadotropic hypogonadism is defined as a deficiency of the pituitary secretion of follicle-stimulating hormone and luteinizing hormone, which results in the impairment of pubertal maturation and of reproductive function. In the absence of pituitary or hypothalamic anatomical lesions and of anosmia (Kallmann syndrome), hypogonadotropic hypogonadism is referred to as isolated hypogonadotropic hypogonadism (IHH). A limited number of IHH cases are due to loss-of-function mutations of the gonadotropin-releasing hormone receptor.
View Article and Find Full Text PDFGraves' disease (GD) is an organ-specific autoimmune disease characterized by hyperthyroidism. Agonistic anti-thyrotropin receptor antibodies (thyroid-stimulating antibodies, TSAb), which mimic the thyrotropin (TSH) action, are thought to cause GD. The precise immunological mechanism of TSAb production, however, remains elusive.
View Article and Find Full Text PDFMultiple sclerosis is a chronic inflammatory disease of the central nervous system with a genetic component. Until now, the more consistent association with the disease is found with the major histocompatibility complex, especially HLA-DRB1*1501-DQB1*0602 haplotype. In this report, we demonstrate the interaction of Cytotoxic T Lymphocyte-associated antigen 4 (CTLA-4 [CD152]) gene with DRB1*15 haplotype in multiple sclerosis genetic susceptibility.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2003
The efficiency of single-nucleotide polymorphism haplotype analysis may be increased by DNA pooling, which can dramatically reduce the number of genotyping assays. We develop a method for obtaining maximum likelihood estimates of haplotype frequencies for different pool sizes, assess the accuracy of these estimates, and show that pooling DNA samples is efficient in estimating haplotype frequencies. Although pooling K individuals increases ambiguities, at least for small pool size K and small numbers of loci, the uncertainty of estimation increases
The metabolic flux of two phenylpropanoid metabolites, N-p-coumaroyloctopamine (p-CO) and chlorogenic acid (CGA), in the wound-healing potato tuber tissue was quantitatively analyzed by a newly developed method based upon the tracer experiment using stable isotope-labeled compounds and LC-MS. Tuber disks were treated with aqueous solution of L-phenyl-d(5)-alanine, and the change in the ratio of stable isotope-labeled compound to non-labeled (isotope abundance) was monitored for p-CO and CGA in the tissue extract by LC-MS. The time-dependent change in the isotope abundance of each metabolite was fitted to an equation that was derived from the formation and conversion kinetics of each compound.
View Article and Find Full Text PDFBackground: DNA pooling is a technique to reduce genotyping effort while incurring only minor losses in accuracy of allele frequency estimates for single nucleotide polymorphism (SNP) markers.
Results: We present an algorithm for reconstructing haplotypes (alleles for multiple SNPs on same chromosome) from pools of two individual DNAs, in which Hardy-Weinberg equilibrium conditions or other assumptions are not required. The program outputs, in addition to inferred haplotypes, a minimal number of haplotype-tagging SNPs that are identified after an exhaustive search procedure.
Kindler syndrome is a rare autosomal-recessive genodermatosis characterized by bullous poikiloderma with photosensitivity. We report the localization to chromosome 20p12.3 by homozygosity mapping and the identification of a new gene, which we propose to name kindlerin.
View Article and Find Full Text PDFStudies of ovine interferon-tau (oIFNtau) gene regulation, an anti-luteolytic factor produced by conceptuses of the ruminant ungulates, have been carried out, but a definitive mechanism for its spatial-temporal transcription has not been elucidated. Recently, specific binding regions for transcription factors AP-1 and Ets-2 on the oIFNtau gene were identified; however, a molecular mechanism by which these factors regulate oIFNtau gene transcription has not been characterized. In the present study, we investigated the potential relationship between AP-1 and Ets-2, and their association with a coactivator, cAMP-response element binding protein-binding protein (CBP), on oIFNtau gene transcription in a transient transfection system using human choriocarcinoma JEG3 cells.
View Article and Find Full Text PDFChromosome 14 is one of five acrocentric chromosomes in the human genome. These chromosomes are characterized by a heterochromatic short arm that contains essentially ribosomal RNA genes, and a euchromatic long arm in which most, if not all, of the protein-coding genes are located. The finished sequence of human chromosome 14 comprises 87,410,661 base pairs, representing 100% of its euchromatic portion, in a single continuous segment covering the entire long arm with no gaps.
View Article and Find Full Text PDFUp to now, the identification of gene mutations causing infertility in humans remains poorly investigated. Temporal progression through meiosis and meiosis specific genes had been extensively characterized in yeast. Recently some mammalian homologous were found.
View Article and Find Full Text PDFWe previously described a reduced expression of the protein tyrosine kinase Lck in T-cells from type 1 diabetic patients, the origin of which is still unknown. The human lck gene, located on chromosome 1p35-34.3, was evaluated as a candidate susceptibility gene for type 1 diabetes.
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