ABCA1 gene polymorphisms and their associations with coronary artery disease and plasma lipids in males from three ethnic populations in Singapore.

Mutations in the ATP-binding cassette transporter ABCA1 underlie Tangier disease and familial hypoalphaliproteinemia (FHA), disorders that are characterised by reduced high-density lipoprotein-cholesterol (HDL-C) concentration and cholesterol efflux, and increased coronary artery disease (CAD). We explored if polymorphisms in the ABCA1 gene are associated with CAD and variations in plasma lipid levels, especially HDL-C, and whether the associations may depend on ethnicity. Male cases and controls from the Singapore Chinese, Malay and Indian populations were genotyped for five ABCA1 single nucleotide polymorphisms.

Mitochondrial DNA analysis reveals diverse histories of tribal populations from India.

We analyzed 370 bp of the first hypervariable region of the mitochondrial DNA (mtDNA) control region in 752 individuals from 17 tribal and four nontribal groups from the Indian subcontinent, to address questions concerning the origins, genetic structure and relationships of these groups. Southern Indian tribes showed reduced diversity and large genetic distances, both among themselves and when compared with other groups, and no signal of prehistoric demographic expansions. These results probably reflect enhanced genetic drift because of small population sizes and/or bottlenecks in these groups.

A double staining flow cytometric assay for the detection of steroid induced apoptotic leucocytes in common carp (Cyprinus carpio).

Steroid hormones play an important role in the regulation of the immune system through different ways. In this in vitro study, the effects of steroid hormones on the apoptosis of leucocytes were evaluated to understand the involvement of this process in the immunocompetence of common carp. Prior to the investigation, a double staining flow cytometric assay using fluorescein diacetate (FDA), which reacts with esterases of viable cells, and propidium iodide (PI), an acid dye that binds with nuclear DNA, was established.

Development of short non-CpG phosphodiester oligonucleotides as immune stimulatory agents.

We have previously reported that DNA isolated from Mycobacterium phlei (M. phlei) stimulates the synthesis of cytokines by monocytes and macrophages independently of the presence of unmethylated CpG motifs. Oligonucleotides as small as five to six bases isolated from M.

Tat stimulates cotranscriptional capping of HIV mRNA.

Here we investigated how capping and methylation of HIV pre-mRNAs are coupled to Pol II elongation. Stable binding of the capping enzyme (Mce1) and cap methyltransferase (Hcm1) to template-engaged Pol II depends on CTD phosphorylation, but not on nascent RNA. Both Mce1 and Hcm1 travel with Pol II during elongation.

STM imaging of flux line arrangements in the peak effect regime.

We present the results of a study of vortex arrangements in the peak-effect regime of 2H-NbSe2 by scanning tunneling microscopy. By slowly increasing the temperature in a constant magnetic field, we observed a sharp transition from collective vortex motion to positional fluctuations of individual vortices at the temperature which coincides with the onset of the peak effect in ac susceptibility. We conclude that the peak effect is a disorder driven transition, with the pinning energy winning against the elastic energy.

Anthelmintic efficacy of Flemingia vestita: genistein-induced effect on the activity of nitric oxide synthase and nitric oxide in the trematode parasite, Fasciolopsis buski.

The root-tuber peel of Flemingia vestita, an indigenous leguminous plant of Meghalaya (Northeast India), has usage in local traditional medicine as curative against worm infections. The peel and its active component, genistein, have been shown to cause flaccid paralysis, deformity of tegumental architecture and alterations in the activity of several enzymes in platyhelminth parasites. To investigate further the mode of action and anthelmintic efficacy of the plant-derived components, the crude peel extract of F.

Effect of alkalinity (pH 10) on ureogenesis in the air-breathing walking catfish, Clarias batrachus.

Exposure of fish to alkaline conditions inhibits the rate of ammonia excretion, leading to ammonia accumulation and toxicity. The purpose of this study was to determine the role of ureogenesis via the urea cycle, to avoid the accumulation of ammonia to a toxic level during chronic exposure to alkaline conditions, for the air-breathing walking catfish, Clarias batrachus, where a full complement of urea cycle enzyme activity has been documented. The walking catfish can survive in water with a pH up to 10.

Genotype associations of factor VII gene with plasma factor VII coagulant activity and antigen levels in healthy Chinese.

A raised plasma factor VII (FVII) level is one of the risk factors for coronary artery disease. The R353Q polymorphism at codon 353 and the 10 base pair (bp) insertion (0/10 bp) polymorphism of the FVII gene have been reported to be associated with plasma FVII levels in several populations. We investigated these two polymorphisms in 209 male and 214 female healthy Chinese.

NO nerves in trematodes, too! NADPH-diaphorase activity in adult Fasciolopsis buski.

The free radical nitric oxide (NO) is a unique molecule with an avidity to react with other molecules and is known to function as a neuronal messenger. This nitrergic transmitter with diverse functions in signal transduction, being a gas, is not stored in synaptic vesicles but is generated in various neuronal cells by a family of nitric oxide synthases (NOSs). The NADPH-d histochemical reaction is regarded as a selective marker for NOS in the neuronal tissue.

Effects of alanine cluster mutations in the D12 subunit of vaccinia virus mRNA (guanine-N7) methyltransferase.

The (guanine-N7)-methyltransferase domain of the vaccinia virus mRNA capping enzyme is a heterodimer composed of a catalytic subunit D1(498-844) bound to a stimulatory subunit D12. To identify structural elements of the 287-amino-acid D12 subunit that participate in binding and activation of the catalytic subunit, we introduced 12 double-alanine mutations at vicinal residues that are conserved in the D12 homologs of other vertebrate poxviruses. His-tagged D12 mutants were coexpressed in bacteria with the D1(498-544) subunit, and the recombinant D1(498-844)/His-D12 heterodimers were purified.

Immune related genetic polymorphisms and schizophrenia among the Chinese.

Genetic association studies were conducted among two independent cohorts of Chinese ethnicity. The samples consisted of cases and unrelated controls, ascertained from Guangzhou, China, and Singapore. The studies were prompted by our earlier report of an association between schizophrenia and HLA DQB1 alleles (HLA DQB1*0602 and HLA DQB1*0303) in the Singapore sample.

Variations in the promoter region of the apolipoprotein A-1 gene influence plasma lipoprotein(a) levels in Asian Indian neonates from Singapore.

We studied the influence of two DNA polymorphisms (-75 bp G/A and +83 bp C/T) in the promoter region of the apolipoprotein A-1 (apoA1) gene on cord plasma level of lipoprotein(a) [Lp(a)] in 1076 newborns of both genders from the three major ethnic groups in Singapore-Chinese, Malays, and Asian Indians. The frequency of the A: allele at -75 bp in the Indians was significantly lower than the Chinese and Malays. There was no linkage disequilibrium between the two sites studied.

Evaluation of intramolecular equilibria in complexes formed between substituted imidazole ligands and nickel (II), copper (II) or zinc (II).

The metal ion-binding properties of imidazole-4-acetate (ImA-), 4(5)-aminoimidazole-5(4)-carboxamide (AImC), 2,2'biimidazole(BiIm) (I. Török et al., J.

Role of ureogenesis in the mud-dwelled Singhi catfish (Heteropneustes fossilis) under condition of water shortage.

The air-breathing Singhi catfish Heteropneustes fossilis was kept inside moist peat for 1 month mimicking their normal habitat in summer and the role of ureogenesis for their survival in a water-restricted condition was studied. The ammonia excretion rate by the mud-dwelled fish increased transiently between 6 and 12 h of re-immersion in water to approximately between eight and 10-fold, followed by a sharp decrease almost to the normal level at the later part of re-immersion. The urea-N excretion by the mud-dwelled fish increased to approximately 11-fold within 0-3 h of re-immersion, followed by a gradual decrease from 9 h onwards.

Racial and genetic determinants of plasma factor XIII activity.

Factor XIII (F XIII), a plasma transglutaminase, is essential for normal hemostasis and fibrinolysis. Plasma F XIII consists of two catalytic A (F XIIIA) and two non-catalytic B (F XIIIB) subunits. Activated F XIII is involved in the formation of fibrin gel by covalently crosslinking fibrin monomers.

Lactase haplotype diversity in the Old World.

Lactase persistence, the genetic trait in which intestinal lactase activity persists at childhood levels into adulthood, varies in frequency in different human populations, being most frequent in northern Europeans and certain African and Arabian nomadic tribes, who have a history of drinking fresh milk. Selection is likely to have played an important role in establishing these different frequencies since the development of agricultural pastoralism approximately 9,000 years ago. We have previously shown that the element responsible for the lactase persistence/nonpersistence polymorphism in humans is cis-acting to the lactase gene and that lactase persistence is associated, in Europeans, with the most common 70-kb lactase haplotype, A.

Characterization of the mRNA capping apparatus of Candida albicans.

The mRNA capping apparatus of the pathogenic fungus Candida albicans consists of three components: a 520- amino acid RNA triphosphatase (CaCet1p), a 449-amino acid RNA guanylyltransferase (Cgt1p), and a 474-amino acid RNA (guanine-N7-)-methyltransferase (Ccm1p). The fungal guanylyltransferase and methyltransferase are structurally similar to their mammalian counterparts, whereas the fungal triphosphatase is mechanistically and structurally unrelated to the triphosphatase of mammals. Hence, the triphosphatase is an attractive antifungal target.

Structure-function analysis of yeast mRNA cap methyltransferase and high-copy suppression of conditional mutants by AdoMet synthase and the ubiquitin conjugating enzyme Cdc34p.

Here we present a genetic analysis of the yeast cap-methylating enzyme Abd1p. To identify individual amino acids required for Abd1p function, we introduced alanine mutations at 35 positions of the 436-amino acid yeast protein. Two new recessive lethal mutations, F256A and Y330A, were identified.

Polynesian origins: insights from the Y chromosome.

The question surrounding the colonization of Polynesia has remained controversial. Two hypotheses, one postulating Taiwan as the putative homeland and the other asserting a Melanesian origin of the Polynesian people, have received considerable attention. In this work, we present haplotype data based on the distribution of 19 biallelic polymorphisms on the Y chromosome in a sample of 551 male individuals from 36 populations living in Southeast Asia, Taiwan, Micronesia, Melanesia, and Polynesia.