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91.
de Monbrison F Raynaud D Latour-Fondanaiche C Staal A Favre S Kaiser K Peyron F Picot S 《Journal of microbiological methods》2003,54(3):391-401
Plasmodium falciparum drug resistance is a major problem in malaria endemic areas. Molecular markers and in vitro tests have been developed to study and monitor drug resistance. However, none, used alone, can provide sufficient data concerning the level of drug resistance and to issue precise guidelines for drug use policies in endemic areas. We propose real-time PCR for the simultaneous detection of pfcrt and pfmdr1 genes mutations and to determine the half-maximal inhibitory response (IC(50)) of antimalarial drug. Using hybridization probes and SybrGreen technology on LightCycler instrument, point mutations of pfcrt and pfmdr1 genes have been successfully detected in 161 human blood samples and determination of IC values was applied to chloroquine-sensitive and chloroquine-resistant strains. Moreover, mixed infections caused by P. falciparum clones with wild-type or mutant alleles could be efficiency separated. The aim of this study was not to provide definitive data concerning the rate of mutations in an endemic area, but to describe a powerful method allowing the quantification of DNA for IC(50) determination and the detection of major pfmdr1 and pfcrt mutations. 相似文献
92.
Boutin P Dina C Vasseur F Dubois S Corset L Séron K Bekris L Cabellon J Neve B Vasseur-Delannoy V Chikri M Charles MA Clement K Lernmark A Froguel P 《PLoS biology》2003,1(3):E68
The gene GAD2 encoding the glutamic acid decarboxylase enzyme (GAD65) is a positional candidate gene for obesity on Chromosome 10p11–12, a susceptibility locus for morbid obesity in four independent ethnic populations. GAD65 catalyzes the formation of γ-aminobutyric acid (GABA), which interacts with neuropeptide Y in the paraventricular nucleus to contribute to stimulate food intake. A case-control study (575 morbidly obese and 646 control subjects) analyzing GAD2 variants identified both a protective haplotype, including the most frequent alleles of single nucleotide polymorphisms (SNPs) +61450 C>A and +83897 T>A (OR = 0.81, 95% CI [0.681–0.972], p = 0.0049) and an at-risk SNP (−243 A>G) for morbid obesity (OR = 1.3, 95% CI [1.053–1.585], p = 0.014). Furthermore, familial-based analyses confirmed the association with the obesity of SNP +61450 C>A and +83897 T>A haplotype (χ2 = 7.637, p = 0.02). In the murine insulinoma cell line βTC3, the G at-risk allele of SNP −243 A>G increased six times GAD2 promoter activity (p < 0.0001) and induced a 6-fold higher affinity for nuclear extracts. The −243 A>G SNP was associated with higher hunger scores (p = 0.007) and disinhibition scores (p = 0.028), as assessed by the Stunkard Three-Factor Eating Questionnaire. As GAD2 is highly expressed in pancreatic β cells, we analyzed GAD65 antibody level as a marker of β-cell activity and of insulin secretion. In the control group, −243 A>G, +61450 C>A, and +83897 T>A SNPs were associated with lower GAD65 autoantibody levels (p values of 0.003, 0.047, and 0.006, respectively). SNP +83897 T>A was associated with lower fasting insulin and insulin secretion, as assessed by the HOMA-B% homeostasis model of β-cell function (p = 0.009 and 0.01, respectively). These data support the hypothesis of the orexigenic effect of GABA in humans and of a contribution of genes involved in GABA metabolism in the modulation of food intake and in the development of morbid obesity. 相似文献
93.
Provost AC Péquignot MO Sainton KM Gadin S Sallé S Marchant D Hales DB Abitbol M 《Comptes rendus biologies》2003,326(9):841-851
The class-B type-I scavenger receptor (SR-BI) plays a key role in cholesterol homeostasis; it mediates the selective uptake of lipoprotein cholesterol to steroidogenic tissues. We show by RT-PCR, western blot, in situ hybridization and immunohistochemistry analysis that SR-BI is highly expressed in different neuro-retinal and non-neuronal cells types on rat eye. Immunohistochemistry of the steroidogenic acute regulatory protein (StAR) involved in neurosteroid production showed the same expression pattern than SR-BI in rat eye. Our results may suggest a key role of these genes in the ocular cholesterol metabolism for membranes biosynthesis and neurosteroidogenesis. 相似文献
94.
Auclair K Huang HW Moënne-Loccoz P Ortiz de Montellano PR 《Protein expression and purification》2003,28(2):340-349
The YLR205c gene of Saccharomyces cerevisiae does not show significant sequence identity to any known gene, except for heme oxygenase (22% to human HO-1). The YLR205 ORF was cloned and overexpressed in both Escherichia coli and S. cerevisiae. Both expression systems yielded proteins that bound heme tightly. The isolated YLR205c protein underwent reduction in the presence of either NADPH-cytochrome P450 reductase or NADH-putidaredoxin-putidaredoxin reductase but did not exhibit heme oxygenase activity. The protein exhibited modest H(2)O(2)-dependent peroxidase activities with guaiacol, potassium iodide, and 2,2(')-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS). Thus, YLR205c codes for a hemoprotein of unknown physiological function that exhibits peroxidase activity. 相似文献
95.
96.
dos Santos Fagundes I Rotta LN Schweigert ID Valle SC de Oliveira KR Huth Krüger A Souza KB Souza DO Perr ML 《Neurochemical research》2001,26(3):245-249
We have investigated the glycine, serine and leucine metabolism in slices of various rat brain regions of 14-day-old or adult rats, using [1-14C]glycine, [2-14C]glycine, L-[3-14C]serine and L-[U-14C]leucine. We showed that the [1-14C]glycine oxidation to CO2 in all regions studied occurs almost exclusively through its cleavage system (GCS) in brains of both 14-day-old and adults rats. In 14-day-old rats, the highest oxidation of [1-14C]glycine was in cerebellum and the lowest in medulla oblongata. In these animals, the L-[U-14C]leucine oxidation was lower than the [1-14C]glycine oxidation, except in medulla oblongata where both oxidations were the same. Serine was the amino acid that showed lowest oxidation to CO2 in all structure studied. In adult rats brains, the highest oxidation of [1-14C]glycine was in cerebral cortex and the lowest in medulla oblongata. We have not seen difference in the lipid synthesis from both glycine labeled, neither in 14-day-old rats nor in adult ones, indicating that the lipids formed from glycine were not neutral. Lipid synthesis from serine was significantly high than lipid synthesis and from all other amino acids studied in all studied structures. Protein synthesis from L-[U-14C]leucine was significantly higher than that from glycine in all regions and ages studied. 相似文献
97.
Female Osmia repeatedly return to their nest to provision it with food and building material. The present study investigates the bees' nest localization performance by modifying visual cues in the near-vicinity of the nest. Each of several arrays of nesting holes was surrounded by four geometrical shapes. Removing some or all of the shapes reduced the proportion of direct returns but never prevented a bee from finding the appropriate array and, within that array, its own nest. The more the pattern was modified, the higher was the error score and the longer the delay, but no bee failed finally to find its nest. Shifting the pattern as well as the whole array of holes shifted homing orientation accordingly. There was no effect of the positions of the removed shapes, of contrast inversion, or of modifying the holes array. Our data are discussed in the light of the snapshot theory. 相似文献
98.
Cecile-Marie Denis Karine Guyot Ann E. Wakefield Daniel Dive Eduardo Dei-Cas Daniel Camus Carmen Odberg-Ferragut 《The Journal of eukaryotic microbiology》1998,45(5):475-483
This work reports the isolation and characterization of a gene encoding a superoxide dismutase (SOD. EC.1.15.1.1.) from Pneumocystis carinii derived from rat. Sense and antisense oligonucleotides, deduced from SOD amino acid sequences from a wide variety of organisms, allowed amplification of a 669 bp genomic DNA fragment specific to this P. carinii. RACE-PCR was used to obtain the major pan of the complementary DNA; the 5- and 3'-genomic regions were obtained respectively from a Mbo I subgenomic library and from an amplified fragment using oligonucleotides designed from the cDNA sequence. Comparison of genomic and cDNA sequences showed an open reading frame of 660 bp interrupted by seven small introns. The deduced amino acid sequence contained 220 residues. Protein sequence alignment demonstrated the highest homology (50.5% identity. 70.3% similarity) with Saccharomyces cerevisiae manganese-SOD (MnSOD) suggesting that P. carinii SOD belongs to the mitochondrial MnSOD group. A putative targeting peptide found at the 5'-end of the P. carinii SOD sequence also suggested its mitochondrial localization. 相似文献
99.
Stéphanie Finet Françoise Bonneté Jean Frouin Karine Provost Annette Tardieu 《European biophysics journal : EBJ》1998,27(3):263-271
A combination of small angle X-ray scattering and gel techniques was used to follow the kinetics of protein crystal growth
as a function of time. Hen egg white lysozyme, at different protein concentrations, was used as a model system. A new sample
holder was designed, in which supersaturation is induced in the presence of salt by decreasing the temperature. It had been
shown previously that a decrease in temperature and/or an increase in crystallizing agent induces an increase in the attractive
interactions present in the lysozyme solutions, the lysozyme remaining monomeric. In the present paper we show that similar
behaviour is observed in NaCl when agarose gels are used. During crystal growth, special attention was paid to determine whether
oligomers were formed as the protein in solution was incorporated in the newly formed crystals. From these first series of
experiments, we did not find any indication of oligomer formation between monomer in solution and crystal. The results obtained
are in agreement with the hypothesis that lysozyme crystals in NaCl grow by addition of monomeric particles.
Received: 28 July 1997 / Revised version: 4 December 1997 / Accepted: 5 December 1997 相似文献
100.
Different cis-Acting Elements Are Involved in the Regulation of TRP1 and TRP2 Promoter Activities by Cyclic AMP: Pivotal Role of M Boxes (GTCATGTGCT) and of Microphthalmia 总被引:7,自引:0,他引:7 下载免费PDF全文