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Biomedical subjects

J Tang

Publications and source records attributed to J Tang.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Allele sequences and population genetics of pentanucleotide tandem repeat D6S957].

OBJECTIVE: Pentanucleotide tandem repeat loci are useful markers of short tandem repeat (STR) for genetic analysis. We focused on the analysis of the DNA sequence for each allele at the pentanucleotide STR locus D6S957 in order to understand their structures in the human genome and to construct human allelic ladder, which is necessary for forensic DNA typing. In order to evaluate the forensic applicability of D6S957, we investigated the genotype distributions and allele frequencies in major ethnic groups. METHODS: A total of 230 samples from unrelated individuals were analyzed by PCR. Allele determination was carried out by comparison with a sequenced human allelic ladder made in-house. An example of each allele was sequenced on an ABI 377 automated sequencer. RESULTS: This pentanucleotide STR exhibited a minimal amount of stutter and provided easily interpretable results. Eight alleles were found in these populations. No evidence of deviation from Hardy-Weinberg equilibrium was observed. In 64 confirmed father/mother/child triplets no mutation events were observed. The mutation rate was indirectly estimated at 2.5 x 10(-5) using a maximum likelihood method. CONCLUSION: D6S957 is a useful marker for forensic casework and paternity analysis.

Alleles↗
PubMed2001

Genotyping and preparation of the recombinant nucleocapsid protein antigen of hantavirus.

OBJECTIVE: To identify new recombinant antigens with potential for diagnosis of hemorrhagic fever with renal syndrome (HFRS) and establish reverse transcription-polymerase chain reaction-restriction fragments length polymorphism (RT-PCR-RFLP) for genotyping of hantavirus. METHODS: One group of primers was used to clone the full-length S genome segment and the partial S genome segment of the N-terminal. The two cloned genes were both fusionally expressed and non-fusionally expressed in the T7 system. The other group of primers was used to establish a RT-PCR method to detect RNAs in 37 virus isolates, 2 positive standard virus strains of hantavirus and 5 negative controls. The method for typing RFLP was set up by digesting the PCR products of 20 virus isolates with Ras I and Hind III. RESULTS: The non-fusionally expressed products with a working concentration of 1:10,000 by chapping enzyme-linked immunosorbent assay (cELISA), presented good biological activity though yields were lower than that of the fusionally expressed products. The specific component of the hantavirus genome (299 bp or 577 bp) was seen in all viral samples. The genotyping of hantavirus showed that 9 out of the total were Hantann (HTN) viruses, 8 were seoul (SEO) viruses and 3 were not determined. CONCLUSIONS: The good working titrer of expressed recombinant antigen showed that it has the potential to replace the natural antigen for detecting hantavirus antibodies. On comparison with cELISA, the detection rates for these two methods were 100% and 84.6%, and the coincidence rate was 84.6%. The former had a 15.4% higher sensitivity than the latter. The typing efficiency of RT-PCR-RFLP and sero-typing method was 85% (17/20) and 55% (11/20), respectively, showing that the former was 30% higher than the latter, while their results were highly consistent.

Antibodies, Viral↗
PubMed2001

Intravascular local gene transfer mediated by protein-coated metallic stent.

OBJECTIVE: To assess the feasibility, efficiency and selectivity of adenovirus-mediated gene transfer to local arterial wall by protein-coated metallic stent. METHODS: A replication-defective recombinant adenovirus carrying the Lac Z reporter gene for nuclear-specific beta-galactosidase (Ad-beta gal) was used in this study. The coating for metallic stent was made by immersing it in a gelatin solution containing crosslinker. The coated stents were mounted on a 4.0 or 3.0 mm percutaneous transluminal coronary angioplasty (PTCA) balloon and submersed into a high-titer Ad-beta gal viral stock (2 x 10(10) pfu/ml) for 3 min, and then implanted into the carotid arteries in 4 mini-swines and into the left anterior descending branch of the coronary artery in 2 mini-swines via 8F large lumen guiding catheters. The animals were sacrificed 7 (n = 4), 14 (n = 1) and 21 (n = 1) days after implantation, respectively. The beta-galactosidase expression was assessed by X-gal staining. RESULTS: The results showed that the expression of transgene was detected in all animal. In 1 of carotid artery with an intact intima, the beta-gal expression was limited to endothelial cells. In vessels with denuded endothelium, gene expression was found in the sub-intima, media and adventitia. The transfection efficiency of medial smooth muscle cells was 38.6%. In 2 animals sacrificed 7 days after transfection, a microscopic examination of X-gal-stained samples did not show evidence of transfection in remote organs and arterial segments adjacent to the treated arterial site. CONCLUSIONS: Adenovirus-mediated arterial gene transfer to endothelial, smooth muscle cells and adventitia by protein-coated metallic stent is feasible. The transfection efficiency is higher. The coated stent may act as a good carrier of adenovirus-mediated gene transfer and have a potential to prevent restenosis following PTCA.

Adenoviridae↗
PubMed2001

Identification of variants of CYP3A4 and characterization of their abilities to metabolize testosterone and chlorpyrifos.

CYP3A4 is the most abundant isoform of cytochrome P450 (CYP) in adult human liver. It metabolizes numerous clinically, physiologically, and toxicologically important compounds. The expression of CYP3A4 varies 40-fold in individual human livers, and metabolism of CYP3A4 substrates varies at least 10-fold in vivo. Single nucleotide polymorphisms (SNPs) in CYP3A4 were identified by direct sequencing of genomic DNA in 72 individuals from three different ethnic groups, including Caucasians, Blacks (African-Americans and African pygmies), and Asians. A total of 28 SNPs were identified, including five which produced coding changes M445T (CYP3A4*3), R162Q (CYP3A4*15), F189S (CYP3A4*17), L293P (CYP3A4*18), and P467S (CYP3A4*19). The latter four represent new alleic variants. Racial variability was observed for the frequency of individual SNPs. CYP3A R162Q was identified only in Black populations with an allelic frequency of 4%. CYP3A4 F189S and CYP3A4 M445T were identified in Caucasians with allelic frequencies 2% and 4%, respectively. L293P and P467S were only observed in Asians at allelic frequencies of 2%. The cDNAs for the F189S, L293P, M445T, and P467S mutant alleles were constructed by site-directed mutagenesis and expressed in an Escherichia coli expression system. Testosterone and the insecticide chlorpyrifos were used to assess the catalytic activities of the most common CYP3A4 allele (CYP3A4*1) and its allelic variants. CYP3A4 F189S exhibited lower turnover numbers for testosterone and chlorpyrifos, while CYP3A4 L293P had higher turnover numbers for both substrates. The turnover numbers of the CYP3A4 M445T and P467S alleles to metabolize these compounds were not significantly different from those of wild-type CYP3A4.

Alleles↗
PubMed2001

[Causal factors of decline disease in exotic pine (Pinus taeda and P. elliottii) plantations].

Investigation on the cause of the decline of exotic pine plantations in Anhui Province was carried out from 1995 to 2000. The results showed that the cause might develop from the interaction of three or more sets of factors. The first group of factors called as predisposing factors were high and low temperature and rainfall, poor soil fertility, and excessive soil bulk density, soil moisture, and of stand density; the second group of factors called as inciting factors were insect defoliators, damaging diseases of needles, late spring frost, severe drought, and excessive resin-tapping, and the third group of factors called as contributing factors were several biotic agents such as shoot blight infected by Sphaeropsis sapinea, decay wood and root rot by fungi, and bark beetles and wood borers.

Causality↗
PubMed2001

The role of hypertension-related gene in aortic vascular smooth muscle cells from mice and rats.

OBJECTIVE: To study the role of hypertension-related gene (HRG-1) in cardiovascular disease. METHODS: The expression of HRG-1 was analyzed with RT-PCR and Northern blotting. Vascular smooth muscle cell (VSMC) proliferation was measured with 3H-TdR incorporation and was confirmed with histological analysis. RESULTS: Northern blot analysis showed that HRG-1 mRNA was expressed not only in VSMC, but also in various rat tissues (heart, brain, lung, kidney, and liver). In addition, the expression of HRG-1 mRNA in heart, brain, kidney and liver of spontaneously hypertensive rat (SHR) was lower than that in the same tissues of Wistar-Kyotorat (WKY). Semi-quantitative RT-PCR and histological analysis showed that the expression of HRG-1 mRNA in ApoE-knockout mice and in animal models of restenosis was decreased and neointimal formation was observed in both models. ET, AII, and IL-1 stimulating VSMC proliferation reduced the expression of HRG-1 mRNA of VSMC. Atrial natriuretic factor (ANF), calcitonin gene-related peptide and adrenomedullin, inhibited VSMC proliferation and elevated the expression of HRG-1 mRNA. These effects could be blocked or attenuated by their corresponding antagonists or antibodies. CONCLUSION: HRG-1 is a gene related to VSMC proliferation. It may play an important role in several occlusive cardiovascular diseases including atherosclerosis, restenosis and hypertension.

Animals↗
PubMed2001

[Transrectal ultrasound examination of the prostate in 100 cases of prostate cancer].

OBJECTIVE: To evaluate the clinical value of transrectal ultrasound (TRUS) examination of the prostate in the diagnosis of prostate cancer (PCA). METHODS: The sonographic and clinical data of 100 patients with PCA were analyzed retrospectively. RESULTS: There was single lesion in 59 patients, diffuse lesion in 17 patients. The size of tumor in 35 patients was < or = 1.5 cm. TRUS in the diagnosis of PCA had an accuracy of 76.0%, specificity of 89.4%, false positive rate of 10.6% and negative predictive value of 88.9%. The level of prostate specific antigen (PSA) increased with the increase in the size of the tumor (P < 0.05). The PSA level of patients with poorly differentiated PCA was significantly higher than that in patients with well differentiated PCA. CONCLUSION: TRUS examination is a convenient procedure for the diagnosis of PCA in its early stage.

Aged↗
PubMed2001

[Physiological indices for evaluating iron-toxicity tolerance of rice (Oryza sativa L.)].

This paper studied the content malodialdehyde (MDA) and the leakage rate of electrolyte in leaves of various rice varieties with different iron-toxicity tolerance and of Echinochloa crusgalli under excessive Fe2+ (160 mg.L-1) stress. The results showed that both the MDA content and the leakage rate of electrolyte in leaves of plants were significantly and negatively correlated with the tolerance of test plants to iron toxicity. It was suggested that both MDA content and leakage rate of electrolyte could be used as the index for evaluating the tolerance to iron toxicity.

Biomass↗
PubMed2001

[The predomination of rotavirus G3 serotype among children with diarrhea in Lulong County in 1998].

OBJECTIVE: To investigate the epidemiology of rotavirus diarrhea among children in rural population. METHODS: 120 stool specimens collected from children with diarrhea during the winter of 1998 in Lulong County, Hebei Province were examined for rotavirus by PAGE and ELISA and for serotype by ELISA and PCR. RESULTS: Rotavirus was detected in children aged between 2-24 months. The positive rate of rotavirus was 39.2% and the ratio of male to female was 1-1.47. All rotavirus RNA profiles were long pattern. The distribution of rotavirus serotypes was type 3(61.7%), followed by type 1(36.2%), and type 4(6.4%). CONCLUSIONS: The epidemiology of rotavirus diarrhea during 1998 rotavirus season in Lulong County was similar to that of other regions in China, but rotavirus serotype G3 was a prevalent strain in Lulong County, which was uncommon and different from the predominant G1 in other places throughout China.

Child, Preschool↗
PubMed2001

[Detection of TT virus DNA and sequence analysis of TTV gene in sera from young children in Nanjing].

OBJECTIVE: To investigate the prevalence of TTV genomes in young children from Nanjing and establish the PCR method for detecting TTV DNA. METHODS: A hemi-nested polymerase chain reaction (PCR) assay was established to detect TTV DNA in 110 young children and two PCR-amplified products were sequenced and the data were analyzed with the computer programs. RESULTS: TTV DNA was detected in 14 out of 110 children, and 222 bp sequences of 2 isolates from the children were analyzed. Compared with representative of published isolates, they have the nucleotide identity of 93.7%-98.6% with TX011. CONCLUSIONS: The infection rate of TTV in children is 12.73%, and 2 isolates from children belong to subgroup G1b. Our results indicates that TTV could be transmitted via other pathway besides hematogenous one, and TTV could be carried by healthy population.

Base Sequence↗
PubMed2001

[Studies on insulin-like growth factor I receptor in fetal rats with intrauterine growth retardation].

OBJECTIVE: This study was conducted to detect the localization of the insulin-like growth factor I receptor (IGF-I R) in the cells and tissues in the rats with intrauterine growth retardation (IUGR) and normal growth rats. METHODS: 21 pregnant rats were randomly divided into the experimental group (IUGR) (n = 12) and the control group (n = 9). Animal models for IUGR were established by clamping the uterine vasculature of pregnant rats for 20 minutes on day 14 of gestation. The control group rats were subjected to Sham-operation. On day 22 of gestation, fetal rats were delivered by cesarean section. Immunohistochemical assay was performed to detect the IGF-I R expression on liver and lung using specific polyclonal antibodies to rat IGF-I R. RESULTS: In the experimental group, the IUGR rats' body weight, height, and the weight of their liver, lung and the placenta were significantly lower than those in the control group. In the IUGR rats' liver, the area ratio of IGF-I R was increased and the average gray level was decreased, compared with those in the control group. In the IUGR rats' lung, the area ratio of IGF-I R was increased, compared with that in the control group, but no difference of average gray level was observed between the two groups. CONCLUSION: The increased expression of IGF-I R in rats with IUGR, may be due to the decrease of IGF-I and the compensative mechanism of the body.

Animals↗
PubMed2001

[Diagnostic significance of audiological and vestibular function examination in the pontocerebellar angle tumor].

OBJECTIVE: To study the diagnostic value of audiological and vestibular function examination in the pontocerebellar angle tumor. METHOD: The data of audiological and vestibular function test were analized retrospectively in 20 subjects with tumors of the pontocerebellar angle. RESULT: Pure tone and ABR waveforms were abnormal in 20 subjects (21 ears), moreover acoustic stapedius reflex and the vestibular function were abnormal in 19 subjects. CONCLUSION: It's valuable that audiological and vestibular function examinations are able to diagnosis the pontocerebellar angle tumor.

Adult↗
PubMed2001

[Plasma cell granuloma of maxillary sinuses].

OBJECTIVE: To study the clinical features and treatment of plasma cell granuloma in maxillary sinuses. METHOD: The clinical information of 3 cases was reported and the literatures were also reviewed. RESULT: All of the 3 cases were cured after Caldwell-Luc operation combined with oral corticosteroids and antiallergic agent. Recurrence hasn't been found in half to 2 years follow-up period. CONCLUSION: Plasma cell granuloma of maxillary sinus is a chronic inflammatory lesion with unknown origin. In almost all of the cases, CT images showed some degree of involvement of the bony wall of the maxillary sinuses. The imaging findings mimicker malignant tumors. But the prognosis were quite well in most of the patients.

Combined Modality Therapy↗
PubMed2001

[Study on the analytical methods of catechins in tea and green tea polyphenol samples by high performance liquid chromatography].

Hypersil BDS C18 and Zorbax SB C18, suitable to separate simultaneously seven kinds of catechins and caffeine, were screened out from seven brands of reversed-phase columns. Mobile phase was a solution of methanol-water-acetic acid (or trifluoro acetic acid). Seven kinds of catechins in tea samples from six places in China and three green tea polyphenol(GTP) samples from different producers were separated and determined in 30 min by isocratic and gradient elutions. The effects of mobile phase components and temperature of column on retention parameters of catechins and caffeine are reviewed. Chromatographic conditions and pretreatment methods of samples were optimized. Gallocatechin gallate(GCG) and (-)-catechin gallate(CG) were identified by electrospray ionization mass spectrometry(ESI-MS) and prepared by high performance liquid chromatography for quantitative analysis. The other catechins, (-)-epigallocatechin (EGC), (+)-catechin (D-C), (-)-epicatechin(EC), (-)-epigallocatechin gallate(EGCG), (-)-epicatechin gallate(ECG) were identified with standards.

Caffeine↗
PubMed2001

[Local recurrence of nasopharyngeal carcinoma with normal mucous membrane after radiation therapy: MR imaging findings].

OBJECTIVE: The purpose of this work was to investigate and analyze the MR imaging features of postradiation local recurrence of nasopharyngeal carcinoma (NPC) with normal mucous membrane. METHODS: 24 such cases were studied. The diagnosis of NPC recurrence was pathologically confirmed in 15 patients, and was corroborated by repeated radiation therapy and serial follow-ups in 9 patients. MR imaging routine procedures and Gd-DTPA enhancement were performed for all patients. RESULTS: The MR imaging findings were as follows: 1. The recurrent tumor mass was located in the prestyloid space in 8 patients, with skull base erosion and intracranial infiltration in 7 patients; 2. Retrostyloid space recurrence in 2 patients; 3. Direct bony erosion of the skull base in 7 patients; 4. Recurrence in nasal cavity and ethmoid sinuses in 3 patients; 5. Submucous cystic recurrence in 2 patients; 6. Mixed patterns of recurrence in 2 patients. Except 2 cases of cystic tumor recurrence, all cases exhibited slight hypo- or iso-intensity on T1-weighted images, slight hyper-intensity on T2-weighted images, and moderate to marked enhancement after Gd-DTPA administration. CONCLUSION: There are several special patterns of local NPC tumor recurrence after radiation therapy in the presence of normal nasopharyngeal mucosa. MR imaging is the method of choice to depict the location and extent of NPC tumor recurrence.

Adult↗
PubMed2001

[The intraoperative application of neural response telemetry with the nucleus CI24M cochlear implant].

OBJECTIVE: To test device integrity and objective auditory reaction for cochlear implant patients intraoperatively. METHODS: Our protocol for intraoperative testing of the implant device includes device electrode impedance test and neural response telemetry (NRT), which measures the electrically evoked auditory nerve compound action potentials (ECAP). RESULTS: We completed electrode integrity tests and NRT intraoperatively on 40 patients with the Nucleus CI24M cochlear implant. We have measured normal implant function on all 40 patients and obtained ECAP results from 39 patients. Out of 33 patients with normal inner ear, typical ECAPs were recorded in 195 electrodes in all 198 testing electrodes(98.5%). In 7 patients with inner ear Mondini dysphasia, affirmative ECAP waveforms were recorded in 26 electrodes in all 42 testing electrodes. The basal electrode ECAP threshold was higher than that of the epical one. CONCLUSIONS: The intraoperative measurements of device function and NRT are quite simple, quick and with high accuracy. Inner ear malformation is an important factor that may affect NRT results.

Action Potentials↗
PubMed2001

[An IR study of ion solvation and association of lithium perchlorate in some organic solvents].

The infrared (IR) spectra of propylene carbonate (PC), gamma-butyrolactone (BL) and diethyl carbonate (DEC) in the presence of LiClO4 have been investigated. It is shown that the interactions between Li+ and these solvents occur on the oxygen atoms of the carbonyl of solvent molecules. On the other hand, spectral curve fitting for band shape of perchlorate anion shows the presence of ion association in these solutions.

4-Butyrolactone↗