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121.
Kim SU Lee KM Park SK Yoo KY Noh DY Choe KJ Ahn SH Hirvonen A Kang D 《Journal of biochemistry and molecular biology》2004,37(5):582-585
To evaluate the potential association between the GSTP1 genotype and the development of breast cancer, a hospital based case-control study was conducted on Korean women. The study population consisted of 171 histologically confirmed incident breast cancer cases and 171 age-matched controls with no present or previous history of cancer. PCR-RFLP was used for the GSTP1 genotyping and statistical evaluations were performed using an unconditional logistic regression model. Postmenopausal women with the GSTP1 Val allele were found to have a reduced risk of breast cancer (OR = 0.3, 95 % CI = 0.10-0.74). A significant interaction was observed between the GSTP1 genotype and alcohol consumption (p for interaction = 0.01); compared with never-drinking women with Ile/Ile genotype, ever-drinking women with the GSTP1 Val allele had almost a three-fold risk of breast cancer (OR = 2.9, 95 % CI = 1.05-7.85), whereas never-drinking women with Val allele had half this risk (OR = 0.5, 95 % CI = 0.27-0.93). Our findings suggest that the GSTP1 polymorphism influences individual susceptibility to breast cancer in the Korean women and this effect may be modified by alcohol consumption. 相似文献
122.
Twelve mecoprop-degrading bacteria were isolated from soil samples, and their genetic and phenotypic characteristics were investigated. Analysis of 16S rDNA sequences indicated that the isolates were related to members of the genus Sphingomonas. Ten different chromosomal DNA patterns were obtained by polymerase-chain-reaction (PCR) amplification of repetitive extragenic palindromic (REP) sequences from the 12 isolates. The isolates were found to be able to utilize the chiral herbicide mecoprop as a sole source of carbon and energy. While seven of the isolates were able to degrade both (R)- and (S)-mecoprop, four isolates exhibited enantioselective degradation of the (S)-type and one isolate could degrade only the (R)-enantiomer. All of the isolates were observed to possess plasmid DNAs. When certain plasmids were removed from isolates MP11, MP15, and MP23, those strains could no longer degrade mecoprop. This compelling result suggests that plasmid DNAs, in this case, conferred the ability to degrade the herbicide. The isolates MP13, MP15, and MP24 were identified as the same strain; however, they exhibited different plasmid profiles. This indicates that these isolates acquired different mecoprop-degradative plasmids in different soils through natural gene transfer. 相似文献
123.
124.
Various thioacetal artemisinin derivatives can inhibit the angiogenesis and might be angiogenesis inhibitors. In particular, 10 alpha-phenylthiodihydroartemisinins (5), 10 beta-benzenesulfonyl-9-epi-dihydroartemisinin (11) and 10 alpha-mercaptodihydroartemisinin (13) exhibit strong growth inhibition activity against HUVEC proliferation. Compound 11 have a good inhibitiory activity upon HUVEC tube formation, and 5 and 11 show a strong inhibitory effect on angiogenesis using CAM assay at 5 microg/egg by 90%. 相似文献
125.
The class C beta-lactamase of Enterobacter cloacae P99 is known to catalyze the hydrolysis of certain acyclic (thio)esters. Previous experiments have employed thioglycolate, m-hydroxybenzoate, and phenylphosphate leaving groups. The relative effectiveness of these leaving groups has now been quantitatively assessed by employment of a series of compounds with common acyl groups, and found to rank in the order phenylphosphate >m-hydroxybenzoate >thioglycolate. Structural models suggest that these leaving groups interact during acylation principally with Tyr 150, Lys 315, and Thr 316 of the beta-lactamase active site. The positions of the leaving group carboxylates in these models is compared with those in published crystal structures of complexes of class C beta-lactamases with beta-lactams. The particular effectiveness of the acyl phosphate indicates the positions of two oxyanions that strongly interact with the active site. This information should be useful in the design of inhibitors of class C beta-lactamases. 相似文献
126.
The distribution and morphology of neurons containing neuronal nitric oxide synthase (NOS), and calcium-binding proteins calbindin D28K and calretinin in the hamster visual cortex were compared by immunocytochemistry. Staining for NOS, calbindin D28K and calretinin was seen both in the specific layers and in the selective cell types. The densest concentration of anti-NOS-immunoreactive (IR) neurons was found in layer VI. Most of the calbindin D28K-IR neurons were located in layers II/III and V while the calretinin-IR neurons were predominantly located in layers II/III. The labeled neurons varied in morphology. The large majority of NOS-IR neurons were round or oval cells with many dendrites coursing in all directions. The majority of the calbindin D28K-IR neurons were stellate and round or oval cells with multipolar dendrites. The majority of the calretinin-IR neurons were vertical fusiform cells with long processes traveling perpendicular to the pial surface. Our study showed that 14.7% and 27.5% of the NOS-IR cells in the hamster visual cortex contained calbindin D28K or calretinin, respectively. These results indicate that NOS, calbindin and calretinin are located in specific layers and specific cell types and the vast majority of NOS-containing neurons are limited to neurons that do not express calbindin D28K or calretinin. 相似文献
127.
The DNA repair machinery must locate and repair DNA damage all over the genome. As nucleosomes inhibit DNA repair in vitro, it has been suggested that chromatin remodeling might be required for efficient repair in vivo. To investigate a possible contribution of nucleosome dynamics and chromatin remodeling to the repair of UV-photoproducts in nucleosomes, we examined the effect of a chromatin remodeling complex on the repair of UV-lesions by Micrococcus luteus UV endonuclease (ML-UV endo) and T4-endonuclease V (T4-endoV) in reconstituted mononucleosomes positioned at one end of a 175-bp long DNA fragment. Repair by ML-UV endo and T4-endoV was inefficient in mononucleosomes compared with naked DNA. However, the human nucleosome remodeling complex, hSWI/SNF, promoted more homogeneous repair by ML-UV endo and T4-endo V in reconstituted nucleosomes. This result suggests that recognition of DNA damage could be facilitated by a fluid state of the chromatin resulting from chromatin remodeling activities. 相似文献
128.
Inhibin is a gonadal hormone which is composed of an alpha-subunit and one of two related beta-subunits (betaA, betaB). Inhibin is important for pituitary FSH regulation, normal follicle development and maintenance of the estrous cycle in the female, whereas the role of inhibin in the male is less clear. Thus, we examined the expression of the inhibin-alpha gene in testis during sexual maturation in male mice, to try to gain insight into its functions in the male. Male mice of the ICR strain attained fertility at 6 weeks of age, and histological analysis revealed that a functional testis was formed, with seminiferous tubules which contain mature sperm and with an abundant population of Leydig cells. Parallel with this sexual maturation, inhibin-alpha subunit protein synthesis increased, whereas synthesis of the activin betaA and activin betaB followed with a delayed time course. Inhibin-alpha mRNA also increased during this critical period, and this corresponded to a change in the methylation status of the inhibin-alpha gene. Taken together, our data reveal that activation of inhibin-alpha gene during testis development correlated with the histological maturation of the testis and the acquisition of fertility in male mice. 相似文献
129.
Slama M Susic D Varagic J Ahn J Frohlich ED 《American journal of physiology. Heart and circulatory physiology》2003,284(2):H691-H697
The systematic evaluation of different transthoracic echocardiographic (TTE) methods to determine cardiac output (CO) and the effect of changes in intravascular volume on echocardiographically determined indexes of cardiovascular structure in the rat has not been documented. With the use of 11 Wistar rats, simultaneous echocardiographic and thermodilution measurements of CO were compared at baseline and after blood withdrawal or transfusion at 43 different levels of intravascular volume and using 10 different echocardiographic approaches. The best correlation (r = 0.93; P < 0.0001), least bias (-3 ml/min), and best precision (16 ml/min) between thermodilution and echocardiographic methods were obtained at the level of aortic annulus using pulsed Doppler. In conclusion, CO could be accurately assessed in rats using TTE and pulsed Doppler at the level of the aortic annulus. This annulus was demonstrated to remain stable, but pulmonary annulus, thoracic aorta, mitral valve, and left ventricular diameters were found to be more modifiable during volumic changes. 相似文献
130.
The enzyme HemK (or PrmC) is one of the first identified methyltransferases that modify glutamine. It methylates the highly conserved GGQ motif in class I release factors (RF1 and RF2) in Escherichia coli. HemK from Thermotoga maritima was over-expressed and crystallized in the presence of S-adenosylmethionine at 296 K using ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.5 A resolution from a native crystal. The crystal is orthorhombic, belonging to the space group I222 (or I2(1)2(1)2(1)), with unit-cell parameters of a = 104.24, b = 118.73, and c = 146.62 A. Two (or three) monomers of recombinant HemK are likely to be present in the crystallographic asymmetric unit, giving a V(M) of 3.62 A3 Da(-1) (or 2.41 A3 Da(-1)), with a solvent content of 62.7% (or 44.0%). 相似文献