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X Gene (x + gene)
Selected AbstractsX chromosome number causes sex differences in gene expression in adult mouse striatumEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2009Xuqi Chen Abstract Previous research suggests that sex differences in the nigrostriatal system are created by direct effects of the sex chromosomes (XX vs. XY), independent of the action of gonadal hormones. Here we tested for sex chromosome effects on expression of three mRNAs in the striatum and nucleus accumbens of adult mice of the four core genotypes model (XX and XY gonadal males, XX and XY gonadal females). Mice were gonadectomized (GDX) at 47,51 days old to eliminate group differences in the levels of gonadal steroids. Three weeks later, mice were killed and brains collected for in situ hybridization of the striatum, or the striatum was dissected out for quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Expression in XX and XY mice was measured by in situ hybridization using riboprobes encoding the dynorphin precursor Pdyn (prodynorphin), the substance P precursor Tac1 (preprotachykinin) or dopamine D2 receptor. XX mice had higher expression, relative to XY mice of the same gonadal sex, of Pdyn and Tac1 mRNA in specific striatal regions. Quantitative PCR confirmed that GDX XX mice have higher Pdyn expression in striatum than XY mice, regardless of their gonadal sex. XX had higher Pdyn expression than XY or XO mice, indicating that the sex chromosome effect is the result of XX vs. XY differences in the number of X chromosomes, probably because of sex differences in the expression of X gene(s) that escape inactivation. We detected no sex chromosome effect on D2 receptor mRNA. [source] A study on sequence variations in pre-S/surface, X and enhancer II/core promoter/precore regions of occult hepatitis B virus in non-B, non-C hepatocellular carcinoma patients in TaiwanINTERNATIONAL JOURNAL OF CANCER, Issue 3 2009Chien-Hung Chen Abstract This study was to investigate the clinical significance and virologic factors of occult hepatitis B virus (HBV) infection in hepatocellular carcinoma (HCC) patients without hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (non-B, non-C) in Taiwan. Serum HBV DNA (occult HBV) was detected in 90 of 222 non-B, non-C HCC patients and 24 of 300 non-B, non-C controls without HCC. Of 90 occult HBV-infected HCC patients, the sequences of HBV pre-S/surface, X and enhancer II/core promoter/precore genes were analyzed from 40 patients. Direct sequencing of such genes was also performed in 24 non-B, non-C controls without HCC and 40 HBsAg-positive HCC controls. Compared with non-B, non-C controls without HCC, non-B, non-C subjects with HCC had significantly higher prevalence of occult HBV (p < 0.0001). Moreover, M1I and Q2K in pre-S2 gene and G1721A were more common in occult HBV-infected patients with HCC than in those without HCC. Compared with the HBsAg-positive HCC controls, occult HBV-infected HCC patients had higher frequencies of M1I and Q2K in pre-S2 gene, G185R and S210N in surface gene, A36T and A44L in X gene, and G1721A in enhancer II gene, and had lower rates of pre-S deletions and A1762T/G1764A, A1846T, G1896A and G1899A in core promoter/precore genes. Multivariate analysis showed Q2K in pre-S2 gene, G1721A and A1846T were independent factors for occult HBV-infected HCC. Our study suggested that the virological factors of HBV related to HCC were different between occult HBV-infected and HBsAg-positive patients. The G1721A, M1I and Q2K in pre-S2 gene may be useful viral markers for HCC in occult HBV carriers. © 2009 UICC [source] Hepatitis B virus BCP, precore/core, X gene mutations/genotypes and the risk of hepatocellular carcinoma in IndiaJOURNAL OF MEDICAL VIROLOGY, Issue 7 2010Mohammad Asim Abstract The study aims to characterize mutations of the HBV genome involving BCP, Precore/core and X regions and also defines HBV genotypes in patients of hepatocellular carcinoma (HCC). The study involved 150 HBV-related HCC cases and 136 HBV-related chronic liver disease patients without HCC as controls. HBV DNA was subjected to mutational analysis using SSCP technique, genotyping by RFLP, and direct nucleotide sequencing. HBV DNA was found in 58.7% (88/150) of the HCC cases and 74.3% (101/136) of controls. HBV mutants were observed in 44.3% of HCC cases and 43.2% of controls. HBV/D was prevalent amongst the patients and controls, followed by HBV/A. The prevalence of the TT1504 mutation in the X gene, the V1753 and T1762/A1764 mutations in the BCP region, and G1914 mutation in the core gene were significantly higher in the HCC group than in the non-HCC group. Multivariate analyses showed that the TT1504, V1753, A1762T/G1764A, and the G1914 mutations and the patient's age, sex, and HBeAg status increased the risk of HCC development significantly. Also, patients with HCC had lower levels of serum albumin, viral load, and platelet counts but higher values of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, bilirubin, and Alpha feto-protein than those of controls (P,<,0.001 for all comparisons). HBV/D was the predominant genotype associated with HCC cases seen in India. The presence of different types of HBV mutations, age, sex, HBeAg status, and viral load was found to increase significantly the risk of HCC development in India. J. Med. Virol. 82: 1115,1125, 2010. © 2010 Wiley-Liss, Inc. [source] Occult hepatitis B viral DNA in liver carcinomas from a region with a low prevalence of chronic hepatitis B infectionJOURNAL OF VIRAL HEPATITIS, Issue 4 2004R. Kannangai Summary., Occult hepatitis B is defined by the presence of hepatitis B viral (HBV) DNA in the serum or liver in persons lacking hepatitis B surface antigen (HBsAg) in the serum. A high prevalence of occult HBV has been reported in hepatocellular carcinoma (HCC) from Asia, but little information is available on the prevalence of occult HBV in HCC from regions with a low prevalence of typical chronic hepatitis B infection. In a retrospective study, 19 cases of primary liver cancer were investigated for the presence of occult HBV DNA by amplification of the surface, core, and X gene. In addition, HBV copy numbers were quantitated by real time polymerase chain reaction, genotyped, and samples tested for covalently closed circular HBV DNA, which is a marker of active viral replication. Occult HBV was found in three of 19 cases (16%). Genotyping was successful in two cases, both of which were genotype A. HBV DNA copy numbers were low, all less than 10 copies/,g liver DNA. No closed circular HBV DNA was detected. Thus, in this study occult HBV was of genotype A and was found in a low percentage of cases of HCC and was associated with low tissue HBV DNA copy numbers and no detectable evidence for viral replication. [source] Correlation of clinical characteristics with detection of hepatitis B virus X gene in liver tissue in HBsAg-negative, and HCV-negative hepatocellular carcinoma patientsLIVER INTERNATIONAL, Issue 5 2002Yoichiro Higashi Abstract: Purpose: We studied the clinical features and the etiology of hepatitis B virus surface antigen (HBsAg)-negative and antibody to hepatitis C virus (anti-HCV) negative patients with hepatocellular carcinoma. Methods: A total of 550 patients, hospitalized with an initial diagnosis of HCC were retrospectively studied. Eighty-one of these patients were HBsAg-positive (HB group), 404 patients were anti-HCV positive (HC group). The other 65 patients were negative for both HBsAg and for anti-HCV (NBNC group). We purified HBV-X gene from HCC or non-tumorous liver tissue of 23 NBNC patients using PCR. Results: Clinical features of NBNC as compared with HB and HC patients were as follows, respectively: non-cirrhosis rate (%): 57,37,15 (P = 0.02 for HB, P < 0.00001 for HC), the proportion of patients with normal ALT concentrations (%): 59,28,10 (P = 0.0002 for HB, P < 0.00001 for HC). Forty of 59 NBNC patients (68%) had anti-HBs and/or anti-HBc (healthy controls: 29%, P < 0.00001) and two of 56 had serum HBV DNA. Twelve of 23 NBNC patients had HBV-X gene in HCC and/or non-cancerous liver tissues (52%). None of 52 had serum HCV RNA. Conclusions: The NBNC patients with HCC had a higher frequency of non-cirrhotic liver without liver injury. The presence of the HBV-X gene in HCC suggests a possible role of past HBV infection in the development of HCC. About half of NBNC HCC is associated with seronegativity for HBsAg and positivity for the HBV-X gene in liver tissue. [source] Exceptional good cognitive and phenotypic profile in a male carrying a mosaic mutation in the FMR1 geneCLINICAL GENETICS, Issue 2 2007LCP Govaerts Fragile X (FRAX) syndrome is a commonly inherited form of mental retardation resulting from the lack of expression of the fragile X mental retardation protein (FMRP). It is caused by a stretch of CGG repeats within the fragile X gene, which can be unstable in length as it is transmitted from generation to generation. Once the repeat exceeds a threshold length, the FMR1 gene is methylated and no protein is produced resulting in the fragile X phenotype. The consequences of FMRP absence in the mechanisms underlying mental retardation are unknown. We have identified a male patient in a classical FRAX family without the characteristic FRAX phenotype. His intelligence quotient (IQ) is borderline normal despite the presence of a mosaic pattern of a pre-mutation (25%), full mutation (60%) and a deletion (15%) in the FMR1 gene. The cognitive performance was determined at the age of 28 by the Raven test and his IQ was 81. However, FMRP expression studies in both hair roots and lymphocytes, determined at the same time as the IQ test, were within the affected male range. The percentage of conditioned responses after delay eyeblink conditioning was much higher than the average percentage measured in FRAX studies. Moreover, this patient showed no correlation between FMRP expression and phenotype and no correlation between DNA diagnostics and phenotype. [source] From collagen chemistry towards cell therapy , a personal journeyINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2007Michael E. Grant Summary The Fell,Muir Award requires the recipient to deliver a lecture and a review manuscript which provides a personal overview of significant scientific developments in the field of matrix biology over the period of the recipient's career. In this context, this review considers the collagen family of structural proteins and the advances in biochemical, molecular biological and genetic techniques which led to the elucidation of the structure, synthesis and function of this important group of extracellular matrix constituents. Particular attention is focussed on early research on the identification and assembly of the soluble precursors of collagen types I and II, and the identification of the precursor of basement membrane collagen type IV. In subsequent studies investigating the maintenance of the chick chondrocyte phenotype in culture, the influence of the extracellular milieu was found to influence markedly both cell morphology and collagen gene expression. These studies led to the discovery of collagen type X whose expression is restricted to hypertrophic chondrocytes at sites of endochondral ossification. Such research provided a prelude to investigations of mammalian endochondral ossification which is known to be aberrant in a variety of human chondrodysplasias and is reactivated in bone fracture repair and in osteoarthritis. The cloning of bovine and then human collagen type X genes facilitated studies in relevant human diseases and contributed to the discovery of mutations in the COL10A1 gene in families with metaphyseal chondrodysplasia type Schmid. Clustering of mutations in the C-terminal domain of the type X collagen molecule has now been widely documented and investigations of the pathogenic mechanisms in animal models are beginning to suggest the prospect of novel treatment strategies. [source] Molecular evolutionary analysis and mutational pattern of full-length genomes of hepatitis B virus isolated from Belgian patients with different clinical manifestationsJOURNAL OF MEDICAL VIROLOGY, Issue 3 2010Mahmoud Reza Pourkarim Abstract Molecular evolutionary patterns of 62 HBV full-length genomes obtained from Belgian patients were characterized. Phylogenetic analysis revealed diverse HBV subgenotypes including A2 and A6 (46.8%), D1,D4 (38.8%), E (9.7%), C1 (1.6%), and B2 (1.6%). The study population consisted of patients with different ethnic origin (Caucasian, Turkish, Asian, Arab, and African). One HBV D/C recombinant isolate was identified, which encoded subtype adw2. An HBV subgenotype D4 with an aberrant subtype ayw4 was detected. Although none of the genotypes was associated with a specific disease outcome, several nucleotide substitutions, deletions and insertions were observed within the HBV preS1/S and X genes, particularly among patients with active chronic hepatitis B infection and patients with cirrhosis. Within the immunological domain of the HBsAg gene, the most frequent substitutions were sT125M and sT118A. High rates of precore and basal core promoter mutations were detected in patients infected with genotype D of HBV. Almost half of the patients who received lamivudine therapy for at least 1 year had HBV variants associated with lamivudine drug resistance. In conclusion, the most common HBV genotypes in West Europe (A and D) also prevail in Belgium. The highest degree of genetic diversity was detected in HBV genotype D. In addition, this study reveals the circulation of exotic HBV genotypes B, C, and E in Belgium. J. Med. Virol. 82:379,389, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||