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J H Tang

Publications and source records attributed to J H Tang.

14 recordsLinked to original sources
PubMed2006

Identification and mapping of Rf-I an inhibitor of the Rf5 restorer gene for Cms-C in maize (Zea mays L.).

The restoration of the C-type cytoplasmic male sterility (Cms) has been a common agriculture practice in the production of hybrid seed for many years. In this study, a series of crosses between select sterile and restorer lines, as well as a backcross population of (Cms-C77 x 6233) x 6233, were used to investigate the restoration of C-type Cms. Our results demonstrated that there was an inhibitor of the Rf5 restorer gene. This inhibitor gene, Rf-I, maps to chromosome 7 and is tightly linked with SSR markers, umc2326 and umc2327, at a genetic distance 4.7 and 3.4 cM, respectively. After analyzing our data combined with previous studies, we propose that the restoration of C-type Cms has two dominant genes, Rf4 and Rf5. Rf4 has the ability to restore all genotypes of Cms-C lines; however, there exists an inhibitor for the other restorer gene, Rf5; thus, it can restore only those genotypes of Cms-C lines lacking the Rf-I inhibitor.

Genes, Plant↗
PubMed2006

Genetic analyses and mapping of a new thermo-sensitive genic male sterile gene in maize.

The present study describes a novel thermo-sensitive genic male sterile (TGMS) line, Qiong68ms. To analyse the mode of fertility inheritance and tag the TGMS gene, a set of F2, BC1 and F(2:3) populations derived from a cross between Qiong68ms and K12 were evaluated for a period of 2 years. Classical genetic analyses and QTL mapping using the mean restoration percentage of the F(2:3) populations revealed that the fertility of Qiong68ms was likely to be governed by a single recessive gene, which was named tms3; the tms3 gene was mapped to a location between SSR markers umc2129 and umc1041, at a distance of 3.7 cM form umc2129 and 1.5 cM form umc1041. The molecular markers tightly linked with tms3 gene will aid in the transfer of the TGMS gene to various background inbred lines using the MAS method.

Chromosome Mapping↗
PubMed2003

Preliminary measurements of aromatic VOCs in public transportation modes in Guangzhou, China.

This study examined the exposure level of aromatic volatile organic compounds (VOCs) in public transportation modes in Guangzhou, China. A total of 40 VOC samples were conducted in four popular public commuting modes (subway, taxis, non-air-conditioned buses and air-conditioned buses) while traversing in urban areas of Guangzhou. Traffic-related VOCs (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene) were collected on adsorbent tubes and analyzed by thermal desorption (TD) and gas chromatography/mass-selective detector (GC/MSD) technique. The results indicate that commuter exposure to VOCs is greatly influenced by the choice of public transport. For the benzene measured, the mean exposure level in taxis (33.6 microg/m(3)) was the highest and was followed by air-conditioned buses (13.5 microg/m(3)) and non-air-conditioned buses (11.3 microg/m(3)). The exposure level in the subway (7.6 microg/m(3)) is clearly lower than that in roadway transports. The inter-microenvironment variations of other target compounds were similar to that of benzene. The target VOCs were well correlated to each other in all the measured transports. The concentration profile of the measured transport was also investigated and was found to be similar to each other. Based on the experiment results, the average B/T/E/X found in this study was about (1.0/4.3/0.7/1.4). In this study, the VOC levels measured in evening peak hours were only slightly higher than those in afternoon non-peak hours. This is due to the insignificant change of traffic volume on the measured routes between these two set times. The out-dated vehicle emission controls and slow-moving traffic conditions may be the major reasons leading elevated in-vehicle exposure level in some public commuting journeys.

Air Pollutants↗
PubMed2001

[Preliminary study of the gene structure of human glycosylphosphatidylinositol specific phospholipase D].

To explore the cDNA and its genomic gene structure of human glycosylphosphatidylinositol specific phospholipase D (GPI-PLD), the stromal cells from human bone marrow were cultured, and the GPI-PLD cDNA was successfully cloned from stromal cells (GenBank Accession AY007546). After analyzing this cDNA, we found that it codes the signal peptide as well as the mature peptide (817 AA) of GPI-PLD. Compared with the cDNA cloned from human pancreas and liver, the homology of the cDNA is 99% and 95% respectively. After searching GenBank, we aligned the genomic gene of the GPI-PLD by DNATools software, and found that the GPI-PLD genomic gene was located in the human 6p22.1-22.3 and contained 25 exons, TATA box, CAAT box, enhancer and the sequence binding homo domain of Pit-1/GHF-1.

Bone Marrow Cells↗
PubMed2001

Methylation of the p15(INK4B) gene in myelodysplastic syndrome: it can be detected early at diagnosis or during disease progression and is highly associated with leukaemic transformation.

To investigate the time sequence of occurrence of p15(INK4B) gene methylation in myelodysplastic syndrome (MDS) and its correlation with leukaemic transformation and survival of patients, the methylation status of the p15(INK4B) promoter region was analysed in 50 patients and was serially studied in 22 of them. Of the 50 patients, 17 (34%) showed p15(INK4B) gene methylation, first demonstrated at diagnosis or during follow-up. When FAB subtypes at the time of study were used in the analysis, the incidence of (p15INK4B) methylation in each risk group of MDS remained stable throughout the course: 0% for low-risk MDS [refractory anaemia (RA) and RA with ring sideroblasts] and from 23% at diagnosis to 30% for high-risk MDS [RA with excess of blasts (RAEB), RAEB in transformation and chronic myelomonocytic leukaemia] respectively. The incidence of p15(INK4B) methylation rose to 60% at initial study and, finally, to 75% in cases of acute myeloid leukaemia (AML) evolved from MDS. Most patients (69%) with p15(INK4B) methylation showed disease progression to AML; it could be detected before, at the time or after the diagnosis of leukaemic transformation. p15(INK4B) methylation in MDS patients implicated a shorter survival time in univariate analyses, but its prognostic significance disappeared in multivariate analyses. In conclusion, p15(INK4B) methylation can be detected early at the diagnosis of MDS or acquired during disease progression. It may play an important role in the pathogenesis of some high-risk MDS and is related to leukaemic transformation of MDS.

Acute Disease↗
PubMed2000

Amino acid substitutions in codons 9-11 of hepatitis C virus core protein lead to the synthesis of a short core protein product.

BACKGROUND: Previous in vitro experiments have indicated that if the ninth codon of the hepatitis C virus (HCV) core gene is mutated from arginine to lysine, a short 16-kDa (P16) instead of a 21-kDa (P21) core protein will be produced. In this study, we aimed to investigate whether similar mutations existed in patients with chronic HCV infection and whether such mutations led to the expression of P16. METHODS: The core gene was isolated from patients' sera by reverse transcription-polymerase chain reaction and sequenced. RESULTS: Three of 10 patients with hepatocellular carcinoma were found to have mutant viruses with missense mutations at codons 9-11: arginine-to-glycine mutation at codon 9 (case 1); lysine-to-glutamine mutation at codon 10 (case 5); and lysine-to-asparagine/threonine-to-alanine double mutations at codons 10 and 11 (case 8). Site-directed mutagenesis and in vitro translation experiments revealed that P16 was expressed by all three mutants. Using gel-purified P21 and P16 proteins obtained from transformed Escherichia coli, the serum titres of anti-P21 and anti-P16 were assayed. Unequal titres of anti-P16 and anti-P21 were found in only cases 1, 5 and 8. A rabbit antibody directed against P16 but not P21 was thus generated for immunohistochemical analysis. P16 was detected in the nuclei of hepatocytes in the peri-hepatoma tissue of a single case (case 1). CONCLUSIONS: These data indicate that missense mutations at codons 9-11 can occur during chronic HCV infection, which results in the expression of P16 core protein.

Aged↗
PubMed1999

Age, gender, and local geographic variations of viral etiology of hepatocellular carcinoma in a hyperendemic area for hepatitis B virus infection.

BACKGROUND: There are etiologic variations of hepatocellular carcinoma (HCC) in different geographic areas. Taiwan is a hyperendemic area for hepatitis B virus (HBV) infection. Hepatitis C virus (HCV) infection also plays an important role in HCC development in Taiwan. Identification of local HCV-endemic areas is important to keep HCV from spreading. This study investigated the etiologic variations of HCC in different geographic areas of Taiwan. METHODS: The authors evaluated the hepatitis B surface antigen (HBsAg) and antibodies to HCV (anti-HCV) status of 284 patients (232 male, 52 female) with HCC. They also evaluated the gender ratio and mean age of these patients. RESULTS: The mean age of HBsAg positive patients was significantly lower than the mean age of HBsAg negative patients (52.6 +/- 12.3 vs. 61.3 +/- 11.2 years) (P < 0.05). The male-to-female ratio was 4.5:1 for all HCC patients, 7:1 for HBsAg positive HCC patients, and 2.8:1 for anti-HCV positive HCC patients. In Chaiyi County in southern Taiwan, the prevalence of anti-HCV in male HCC patients was 52%, significantly greater than that of Taiwan as a whole (27.6%) (P = 0.07). However, the prevalence of anti-HCV in male HCC patients in Taipei County in northern Taiwan was 8.7%, significantly less than that of Taiwan as a whole (P = 0.043). Of a total of 65 Chiayi-based HCC patients, 55.4% were anti-HCV positive and 46.2% were HBsAg positive. In the Chiayi area, results of multiple logistic regression showed that the HCC patients who were age 60 years or older or who were living in the city area both had highly HCV-related disease. CONCLUSIONS: The mean age of patients with HBV-related HCC was significantly lower than that of patients with non-HBV-related HCC. The male-to-female ratio for patients with HBV-related HCC was significantly higher than that of patients with HCV-related HCC. The authors identified an area of Taiwan in which HCV-related HCC was prevalent.

Age Factors↗
PubMed1998

Emergence of an S gene mutant during thymosin alpha1 therapy in a patient with chronic hepatitis B.

The presence of a hepatitis B virus S gene mutant was investigated in a patient being treated with thymosin alpha1. He was seropositive for hepatitis B e antigen throughout therapy but was intermittently seronegative for hepatitis B surface antigen (HBsAg) by an RIA. Sequence analysis revealed an S gene mutant in HBsAg-seronegative serum with two consecutive amino acid substitutions: threonine115-to-isoleucine and threonine116-to-asparagine, whereas no amino acid substitution or deletion was found in the pre-S region. A site-directed mutagenesis experiment confirmed that these mutations were responsible for the failure to detect HBsAg. In summary, an S gene mutant was identified in an HBsAg-seronegative patient. The mutations were located outside the putative "a" determinant. The emergence of an S gene mutant during thymosin alpha1 treatment suggests that enhanced host immunity against HBsAg may play a role in its antiviral activity.

Adult↗
PubMed1997

Causes of blindness among Navajo Indians: an update.

BACKGROUND: The causes of blindness among Navajo Indians, an ethnically distinct community within the United States, were last studied in 1982. This article presents an updated report on the causes of blindness among the Navajo. METHODS: Staff optometrists at each of the hospitals and clinics on the Navajo Reservation collected information for each affected eye: date of onset, cause, blinding process, and best visual acuity. In terms of the total number of eyes affected, it was found that the most frequently encountered etiology was trauma, followed by congenital causes, diabetes mellitus, primary open-angle glaucoma, age-related macular degeneration, and trachoma. CONCLUSIONS: Considering raw numbers as well as preventability, it is suggested that trauma, diabetes mellitus, and primary open-angle glaucoma be targeted for a focused intervention of patient-as well as public-education aimed at reducing blindness from these causes.

Adolescent↗
PubMed1989

[Study on the mechanism of glucose intolerance and insulin resistance in epidemic hemorrhagic fever].

Intravenous glucose tolerance test (ivGTT) and insulin releasing test (IRT) were performed in 32 cases with epidemic hemorrhagic fever (EHF). 23 patients had impaired glucose tolerance, 17 patients showed hyperinsulinemia in fasting state, 12 patients had flat insulin response curves and most patients had higher plasma levels of growth hormone (GH), cortisol (F), norepinephrine (NE) and epinephrine (E) in critical stage than in convalescent stage. These data suggest that in EHF there are disturbed glucose metabolism and insulin resistance due to decreased pancreatic B cell reservoir and increased insulin antagonists such as GH, F, NE, E etc. It is suggested that use of insulin in addition to intravenous glucose infusion may be beneficial to glucose utilization in EHF.

Adolescent↗