945 research outputs found
Nucleotide diversity and association genetics of Xyloglucan Endotransglycosylase/hydrolase (XTH) and cellulose synthase (CesA) genes in Neolamarckia cadamba.
A detailed study was carried out to discover single nucleotide polymorphisms (SNPs) from Neolamarckia cadamba partial XTH (~1283bp) and CesA (778bp) DNA sequences and further associates those SNPs with basic wood density. Primers were designed in flanking the partial XTH and CesA genes from 15 N. cadamba trees. The amplified DNA fragments were sequenced and the basic wood density measurements were determined for each tree. The sequence variation analyses revealed that 34 SNPs (2.65% occurrence) and 3 SNPs (0.39% occurrence) were found in 15 partial genomic DNA sequences of NcXTH1 and NcCesA1, respectively. All the SNPs were discovered in both exon and intron regions. NcXTH1 examined sites showed higher nucleotide diversities of π = 0.00402 and θw = 8.919 when compared to NcCesA1 (π = 0.00127; θw = 0.9226). The LD decayed slowly with distance of polymorphic sites in a linear pattern with the mean R2 value of 0.000687. Association genetics study showed that 2 SNPs from NcXTH1 genes were significantly associated with basic wood density (p<0.05) of N. cadamba. Once the gene-associated SNP markers in NcXTH1 genes are validated, it could be potentially used as a tool in Gene-Assisted Selection (GAS) of N. cadamba trees. This study has also demonstrated that the candidate-gene based association genetics is a powerful approach to dissect complex adaptive traits for organism lacking a genome sequence or reference genomic resources
Involvement of claudin-7 in HIV infection of CD4(-) cells
BACKGROUND: Human immunodeficiency virus (HIV) infection of CD4(-) cells has been demonstrated, and this may be an important mechanism for HIV transmission. RESULTS: We demonstrated that a membrane protein, claudin-7 (CLDN-7), is involved in HIV infection of CD4(-) cells. A significant increase in HIV susceptibility (2- to 100-fold) was demonstrated when CLDN-7 was transfected into a CD4(-) cell line, 293T. In addition, antibodies against CLDN-7 significantly decreased HIV infection of CD4(-) cells. Furthermore, HIV virions expressing CLDN-7 on their envelopes had a much higher infectivity for 293T CD4(-) cells than the parental HIV with no CLDN-7. RT-PCR results demonstrated that CLDN-7 is expressed in both macrophages and stimulated peripheral blood leukocytes, suggesting that most HIV virions generated in infected individuals have CLDN-7 on their envelopes. We also found that CLDN-7 is highly expressed in urogenital and gastrointestinal tissues. CONCLUSION: Together these results suggest that CLDN-7 may play an important role in HIV infection of CD4(-) cells
Plasma Bmil mRNA as a potential prognostic biomarker for distant metastasis in colorectal cancer patients
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Characterization of a potent non-cytotoxic shRNA directed to the HIV-1 co-receptor CCR5
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
A 10-year study reveals clinical and laboratory evidence for the 'semi-invasive' properties of chronic pulmonary aspergillosis
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Clinical and functional effects of mutations in the DAX-1 gene in patients with adrenal hypoplasia congenita
Adrenal hypoplasia congenita (AHC) is an X-linked disorder caused by mutations in a gene referred to as DAX-1. AHC is characterized by adrenal insufficiency and failure to undergo puberty because of hypogonadotropic hypogonadism. The DAX-1 protein is structurally related to orphan nuclear receptors, although it lacks the characteristic zinc finger DNA-binding domain that is highly conserved in other members of this family. In this report, we describe the clinical features and genetic alterations in six families with AHC. These patients reveal the variable clinical presentation of adrenal insufficiency in AHC and underscore the importance of considering this diagnosis. Nonsense mutations that introduce a stop codon were found in three cases (W171X, W171X, Y399X). Frameshift mutations (405delT, 501delA, and 702delC), each of which resulted in a premature stop codon at amino acid 263, were found in the other three families. Three of these mutations (Y399X, 405delT, 702delC) are novel. Using transient gene expression assays to assess DAX-1 function, these mutations were shown to eliminate the ability of DAX-1 to repress the transcription of genes that are stimulated by a related nuclear receptor, steroidogenic factor-1. These studies reveal the variable clinical presentation of DAX-1 mutations and emphasize the value genetic testing in boys with primary adrenal insufficiency and suspected X-linked AHC
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Predicting first-episode psychosis patients who will never relapse over 10 years.
BACKGROUND: Although relapse in psychosis is common, a small proportion of patients will not relapse in the long term. We examined the proportion and predictors of patients who never relapsed in the 10 years following complete resolution of positive symptoms from their first psychotic episode. METHOD: Patients who previously enrolled in a 12-month randomized controlled trial on medication discontinuation and relapse following first-episode psychosis (FEP) were followed up after 10 years. Relapse of positive symptoms was operationalized as a change from a Clinical Global Impression scale positive score of <3 for at least 3 consecutive months to a score of ⩾3 (mild or more severe). Baseline predictors included basic demographics, premorbid functioning, symptoms, functioning, and neurocognitive functioning. RESULTS: Out of 178 first-episode patients, 37 (21%) never relapsed during the 10-year period. Univariate predictors (p ⩽ 0.1) of patients who never relapsed included a duration of untreated psychosis (DUP) ⩽30 days, diagnosed with non-schizophrenia spectrum disorders, having less severe negative symptoms, and performing better in logical memory immediate recall and verbal fluency tests. A multivariate logistic regression analysis further suggested that the absence of any relapsing episodes was significantly related to better short-term verbal memory, shorter DUP, and non-schizophrenia spectrum disorders. CONCLUSIONS: Treatment delay and neurocognitive function are potentially modifiable predictors of good long-term prognosis in FEP. These predictors are informative as they can be incorporated into an optimum risk prediction model in the future, which would help with clinical decision making regarding maintenance treatment in FEP
Crystal Structure of a Novel Esterase Rv0045c from Mycobacterium tuberculosis
There are at least 250 enzymes in Mycobacterium tuberculosis (M. tuberculosis) involved in lipid metabolism. Some of the enzymes are required for bacterial survival and full virulence. The esterase Rv0045c shares little amino acid sequence similarity with other members of the esterase/lipase family. Here, we report the 3D structure of Rv0045c. Our studies demonstrated that Rv0045c is a novel member of α/β hydrolase fold family. The structure of esterase Rv0045c contains two distinct domains: the α/β fold domain and the cap domain. The active site of esterase Rv0045c is highly conserved and comprised of two residues: Ser154 and His309. We proposed that Rv0045c probably employs two kinds of enzymatic mechanisms when hydrolyzing C-O ester bonds within substrates. The structure provides insight into the hydrolysis mechanism of the C-O ester bond, and will be helpful in understanding the ester/lipid metabolism in M. tuberculosis
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