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41.
So MT Leon TY Cheng G Tang CS Miao XP Cornes BK Diem NN Cui L Ngan ES Lui VC Wu XZ Wang B Wang H Yuan ZW Huang LM Li L Xia H Zhu D Liu J Nguyen TL Chan IH Chung PH Liu XL Zhang R Wong KK Sham PC Cherny SS Tam PK Garcia-Barcelo MM 《PloS one》2011,6(12):e28986
Rare (RVs) and common variants of the RET gene contribute to Hirschsprung disease (HSCR; congenital aganglionosis). While RET common variants are strongly associated with the commonest manifestation of the disease (males; short-segment aganglionosis; sporadic), rare coding sequence (CDS) variants are more frequently found in the lesser common and more severe forms of the disease (females; long/total colonic aganglionosis; familial).Here we present the screening for RVs in the RET CDS and intron/exon boundaries of 601 Chinese HSCR patients, the largest number of patients ever reported. We identified 61 different heterozygous RVs (50 novel) distributed among 100 patients (16.64%). Those include 14 silent, 29 missense, 5 nonsense, 4 frame-shifts, and one in-frame amino-acid deletion in the CDS, two splice-site deletions, 4 nucleotide substitutions and a 22-bp deletion in the intron/exon boundaries and 1 single-nucleotide substitution in the 5' untranslated region. Exonic variants were mainly clustered in RET the extracellular domain. RET RVs were more frequent among patients with the most severe phenotype (24% vs. 15% in short-HSCR). Phasing RVs with the RET HSCR-associated haplotype suggests that RVs do not underlie the undisputable association of RET common variants with HSCR. None of the variants were found in 250 Chinese controls. 相似文献
42.
Ferdinand Bohlmann Karl-Heinz Knoll Christa Zdero Pradip Kumar Mahanta Michael Grenz Albert Suwita Dorothea Ehlers Ngo Le Van Wolf-Rainer Abraham Arvind Anant Natu 《Phytochemistry》1977,16(7):965-985
Investigation of about 50 Senecio species has afforded many new substances, in addition to known compounds. Present in these plants are 23 fura 相似文献
43.
Besides coumarin, nobiletin, lucidin dimethyl ether and 5,6,7,3′,4′-pentamethoxyflavone, two new highly oxygenated flavones were isolated from Eupatorium coelestinum. Their structures were determined by spectroscopic methods and alkaline degradations as 5,6,7,8,3′,4′,5′ -heptamethoxyflavone and 5,6,7,8,5′-pentamethoxy-3′,4′-methylenedioxyflavone. 相似文献
44.
Jindamorakot S Am-In S Thuy TT Duy ND Kawasaki H Potacharoen W Limtong S Tanticharoen M Nakase T 《The Journal of General and Applied Microbiology》2004,50(5):261-269
Six strains of anamorphic yeasts isolated from insect frass collected in several regions of Thailand were assigned to the genus Candida based on the conventional taxonomic criteria used for yeast classification. These strains have Q-7 as the major ubiquinone and are suggested to have close relationships to the genus Pichia. Three strains, ST-225, ST-228 and ST-229, have identical nucleotide sequences in the D1/D2 domain of 26S rDNA and are closely related to Pichia japonica, but differ by six nucleotides (1.1% ) from this species. These three strains are considered to represent a single new species, which is described as Candida easanensis sp. nov. Two strains, ST-311 and ST-320, have identical sequences in the D1/D2 domain and resemble Pichia veronae and Pichia fabianii but differ from them by nine nucleotides (1.6%) in D1/D2 sequences. The two strains are described as Candida pattaniensis sp. nov. The remaining strain, ST-37, is related to Pichia americana and Pichia bimundalis but differs by six(1.1%) and seven (1.2%) nucleotides from these species, respectively. This strain is described as Candida nakhonratchasimensis sp. nov. 相似文献
45.
T.V. Nguyen S. Vigneswaran H.H. Ngo D. Pokhrel T. Viraraghavan 《Engineering in Life Science》2006,6(1):86-90
Arsenic (As) is a highly toxic metalloid found in ground and surface water. Arsenic contamination in drinking water leads to harmful effects on human health. To eliminate arsenic from drinking water, several technologies such as coagulation, adsorption, ion exchange, filtration, membrane processes, etc., have been used. In this study, three technologies were evaluated for arsenic removal. Results from batch kinetic experiments showed that iron coated sand (IOCS‐2) can remove more than 90 % of As from synthetic water. Experiments were conducted with three different pH values (6, 7, and 8) and an initial As concentration of 260 μg/L. A new material, developed in this study, namely iron coated sponge (IOCSp), was found to have a high capacity in removing both As (V) and As (III). Each gram of IOCSp adsorbed about 160 μg of As within a 9‐hour contact period of IOCSp with As solution. Low pressure nanofiltration removed more than 94 % of As from an influent containing 440 μg/L As. The applied pressure was varied from 85 to 500 kPa. 相似文献
46.
Kathy T. Ngo Markus Junker Gloria Vo John M. Olson Volker Hartenstein 《Developmental biology》2010,346(2):284-43
The optic lobe forms a prominent compartment of the Drosophila adult brain that processes visual input from the compound eye. Neurons of the optic lobe are produced during the larval period from two neuroepithelial layers called the outer and inner optic anlage (OOA, IOA). In the early larva, the optic anlagen grow as epithelia by symmetric cell division. Subsequently, neuroepithelial cells (NE) convert into neuroblasts (NB) in a tightly regulated spatio-temporal progression that starts at the edges of the epithelia and gradually move towards its centers. Neuroblasts divide at a much faster pace in an asymmetric mode, producing lineages of neurons that populate the different parts of the optic lobe. In this paper we have reconstructed the complex morphogenesis of the optic lobe during the larval period, and established a role for the Notch and Jak/Stat signaling pathways during the NE-NB conversion. After an early phase of complete overlap in the OOA, signaling activities sort out such that Jak/Stat is active in the lateral OOA which gives rise to the lamina, and Notch remains in the medial cells that form the medulla. During the third instar, a wave front of enhanced Notch activity progressing over the OOA from medial to lateral controls the gradual NE-NB conversion. Neuroepithelial cells at the medial edge of the OOA, shortly prior to becoming neuroblasts, express high levels of Delta, which activates the Notch pathway and thereby maintains the OOA in an epithelial state. Loss of Notch signaling, as well as Jak/Stat signaling, results in a premature NE-NB conversion of the OOA, which in turn has severe effects on optic lobe patterning. Our findings present the Drosophila optic lobe as a useful model to analyze the key signaling mechanisms controlling transitions of progenitor cells from symmetric (growth) to asymmetric (differentiative) divisions. 相似文献
47.
Duc HN van Trommel NE Sweep FC Massuger LF Thomas CM 《The International journal of biological markers》2006,21(1):45-49
OBJECTIVE: Human chorionic gonadotropin (hCG) is widely used in the management of hydatidiform mole and persistent trophoblastic disease (PTD). Studies on hyperglycosylated human chorionic gonadotropin (invasive trophoblast antigen, ITA) in PTD are limited. In serum samples taken before evacuation of molar pregnancies we measured the concentrations of free hCG beta-subunit (free hCGbeta), "total" hCG (hCG+hCGbeta) and ITA, and determined whether ITA, the two other hCG analytes, or the calculated ratios of hCGbeta/hCG+hCGbeta, hCGbeta/ITA and hCG+hCGbeta/ITA could predict the later development of PTD. DESIGN: A retrospective study based on blood specimens collected in the Dutch Central Registry for Hydatidiform Moles. The study group comprised 97 patients with hydatidiform moles who did not develop PTD after mole evacuation and 33 patients who did develop PTD. Methods: Serum samples from 130 patients with hydatidiform mole with or without PTD were assayed using specific (radio)immunoassays for free hCGbeta, total hCG, and ITA. From these analytes we also calculated the ratios hCGbeta/hCG+hCGbeta, hCGbeta/ITA, and hCG+hCGbeta/ITA. To predict the development of PTD from these analytes and parameters we performed receiver-operating characteristic (ROC) curve analysis, resulting in areas under the curve (AUCs) that represented the diagnostic accuracy which was rated in a range from excellent (AUC >0.9 or <0.1) to poor (AUC 0.4-0.6). Results: The diagnostic accuracy of ITA was moderate (0.618) and not different from that of free hCGbeta (0.610) and hCG+hCGbeta (0.622). CONCLUSIONS: ITA as well as the other analytes and parameters in serum taken prior to evacuation from patients with molar pregnancies cannot be used to predict the subsequent development of persistent trophoblastic disease. 相似文献
48.
Oligoribonuclease is a common downstream target of lithium-induced pAp accumulation in Escherichia coli and human cells 总被引:1,自引:1,他引:0 下载免费PDF全文
We identified Oligoribonuclease (Orn), an essential Escherichia coli protein and the only exonuclease degrading small ribonucleotides (5mer to 2mer) and its human homologue, small fragment nuclease (Sfn), in a screen for proteins that are potentially regulated by 3′-phosphoadenosine 5′-phosphate (pAp). We show that both enzymes are sensitive to micromolar amounts of pAp in vitro. We also demonstrate that Orn can degrade short DNA oligos in addition to its activity on RNA oligos, similar to what was documented for Sfn. pAp was shown to accumulate as a result of inhibition of the pAp-degrading enzyme by lithium, widely used to treat bipolar disorder, thus its regulatory targets are of significant medical interest. CysQ, the E.coli pAp-phosphatase is strongly inhibited by lithium and calcium in vitro and is a main target of lithium toxicity in vivo. Our findings point to remarkable conservation of the connection between sulfur- and RNA metabolism between E.coli and humans. 相似文献
49.
Ngo Mbing J Enguehard-Gueiffier C Atchadé Ade T Allouchi H Gangoué-Piéboji J Mbafor JT Tih RG Pothier J Pegnyemb DE Gueiffier A 《Phytochemistry》2006,67(24):2666-2670
The leaves of Ouratea nigroviolacea (Ochnaceae) afforded two biflavonoids, ouratine A and B together with agathisflavone and stigmasterol. The biflavonoids were characterized as 4'-O-methylated apigeninyl-(I-6, II-8)-4'-O-methylatedapigenin and 4'-O-methylated apigeninyl-(I-6, II-8) apigenin by spectral and chemical transformation studies. 相似文献
50.
The collection of IR spectra through microscope optics and the visualization of the IR data by IR imaging represent a visualization approach, which uses infrared spectral features as a native intrinsic contrast mechanism. To illustrate the potential of this spectroscopic methodology in breast cancer research, we have acquired IR-microspectroscopic data from benign and malignant lesions in breast tissue sections by point microscopy with spot sizes of 30-40 μm. Four classes of distinct breast tissue spectra were defined and stored in the data base: fibroadenoma (a total of 1175 spectra from 14 patients), ductal carcinoma in situ (a total of 1349 spectra from 8 patients), connective tissue (a total of 464 spectra), and adipose tissue (a total of 146 spectra). Artifical neural network analysis, a supervised pattern recognition method, was used to develop an automated classifier to separate the four classes. After training the artifical neural network classifier, infrared spectra of independent external validation data sets (“unknown spectra”) were analyzed. In this way, all spectra (a total of 386) taken from micro areas inside the epithelium of fibroadenomas from 4 patients were correctly classified. Out of the 421 spectra taken from micro areas of the in situ component of invasive ductal carcinomas of 3 patients, 93% were correctly identified. Based on these results, the potential of the IR-microspectroscopic approach for diagnosing breast tissue lesions is discussed. 相似文献