Search PubMed⌕ Search

Biomedical subjects

X Tang

Publications and source records attributed to X Tang.

At least 271 records · Page 15Linked to original sources
PubMed1994

Epithelial inclusion cysts in an intrapancreatic accessory spleen.

A 38 year old male underwent distal pancreatectomy for benign cystic pancreatic tumor. The pancreas tail contained a 2.3 x 2.1 cm accessory spleen associated with multiple epithelial inclusion cysts. The cysts were of varying sizes (max: 1.4 cm), lined by non-keratinizing squamous epithelium with a few mucin-producing cells, and filled with serous material. This is the fifth reported case of so-called 'epidermoid' cysts in the intrapancreatic accessory spleen.

Adult↗
PubMed1994

Mixed tumor of the external auditory canal.

A mixed tumor with apocrine differentiation seen in the external auditory canal of a 39 year old male is reported. The well demarcated polypoid tumor showed proliferation of elongated gland-like or duct-like structures lined by two rows of epithelial cells, occasionally accompanied by foci of keratinization. There were fat cells in the myxoid stroma, in which no chondroid elements were seen. This neoplasm is considered to have arisen from the ceruminous gland, the modified apocrine gland of the skin.

Actins↗
PubMed1994

Screening anti-HIV Chinese materia medica with HIV and equine infectious anemic virus reverse transcriptase.

The inhibitory activities of human immunodeficiency virus reverse transcriptase (HIV-RT) inhibitors PFA and Suramin against HIV-RT and equine infectious anemic virus reverse transcriptase (EIAV-RT) were studied in this paper. The 50% inhibitory concentration (IC50) of HIV-RT and EIAV-RT treated by PFA and Suramin were 0.2 mumol, 9.8 mumol and 17 mumol, 19.9 mumol, respectively. More than thirty Chinese medicines, including recipes, herbs, extracts of traditional materia medica and isolated compounds were tested using HIV-RT and EIAV-RT as target enzymes. It was found that 5 crude extracts such as Rhizoma Polygoni Cuspidati, and Radix Notoginseng, 7 isolated compounds like Flavone of Ramulus Visci, Flavone of Ajuga Decumbens Thumb, and Aristolochic acid, as well as the extract of the complex prescription Xiao Chai Hu Tang have shown various inhibitory actions on these two enzymes. The activities of the two enzymes were comparable, but HIV-RT was more sensitive, suggesting that HIV-RT can be used as index for the screening of anti-aids drugs.

Animals↗
PubMed1994

[Evaluation of posttraumatic hearing loss].

In this study a comprehensive audiometry was applied to detect the hearing loss in 400 patients (531 ears) with difficult-to-test hearing loss induced by ear or skull injury. It was found that the real PTA detectable rate reached 95.29% and the incidence of hearing loss was 82.11%, of which 68.81% were related to injury. The incidence of nonorganic deafness was 77.59%, i.e., the incidence of hearing loss exaggerated by patients was 57.25% (tested ears), simulated deafness was 16.20% and functional deafness was 4.14%. The principle of dealing with nonorganic deafness was discussed.

Adolescent↗
PubMed1994

[Risk factors of prostate cancer--a matched case-control study].

A 1:2 matched case-control study was used to determine the risk factors of prostate cancer. Twenty-seven cases of prostate cancer were matched with an equal number of other malignant tumor cases (non-urological tumor) and other urological cases (non-malignant tumor). Both study and control groups were the same in age, sex, race, and day of admission. All of these patients were treated in the First Affiliated Hospital of West China University of Medical Sciences. The questionnaire was used to survey the both groups of patients. Such data as diet, lifestyle, marital status and past history of other prostate diseases were obtained. Single factor analysis and multiple conditional logistic regression analysis were used to estimate the relative risk (RR), 95% confidence interval (95% CI) and P values. Statistical analysis was performed using the Egret, Epilog soft ware. The results were as follows: 1. Increasing dietary vitamin A was associated with a significant decrease in the risk of prostate cancer (RR = 0.948, 95% CI = 0.9309-0.9947, P = 0.029). This factor also showed dose response gradients. The relative risk was decreasing with exposure dose increasing. 2. The positive previous prostate history, such as prostatitis and benign prostate hyperplasia, increased the risk of prostate cancer (RR = 6.385, 95% CI = 1.046-38.97, P = 0.045). 3. Another finding in the widower, divorce and remarried men (RR = 4.312, 95% CI = 1.367-13.6, P = 0.013). And 4. There was no relationship between the risk of prostate cancer and dietary fat intake, vasectomy, socioeconomic status, familial malignant tumor history, smoking and alcohol consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Negative regulation of the gene for H-2Kb class I antigen by adenovirus 12-E1A is mediated by a CAA repeated element.

Both positive and negative regulatory elements responsive to the product of the adenovirus type 12 E1A gene are located in the promoter region of the gene for mouse H-2Kbm1 major histocompatibility complex (MHC) class I antigen (1). We have analyzed the negative regulatory element that is affected by E1A and identified a target CAA repeated motif, CAA(A)CAAA, within -1725 to -1705 and -1591 to -1568 in a 316-bp sequence located in the far upstream region of H-2Kb promoter (-1837 to -1522; +1 refers to the cap site). The extent of cell surface expression of the MHC class 1 antigen was significantly decreased in the case of transfectants obtained by introducing an expression plasmid that included MHC class 1 cDNA with the CAA repeated element, as compared with that of a plasmid with mutated CAA repeats. We have also characterized the nuclear proteins that bind to this motif. The analysis of the effects of mutations during competition assays of in vivo and gel retardation competition assays demonstrated that the CAA repeated element is essential not only for E1A-dependent repression of transcription but also for the cell surface expression of the product of the mouse H-2Kb class I gene, presumably through nuclear proteins that specifically bind to it.

Adenovirus E1A Proteins↗
PubMed1993

Organization and structure of the 1-aminocyclopropane-1-carboxylate oxidase gene family from Petunia hybrida.

In this paper we present the structural analysis of the 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene family from Petunia hybrida. Southern blot analysis and restriction endonuclease mapping showed that two cloned regions of the petunia genome contained sequences highly homologous to a previously isolated ACC oxidase cDNA clone. Nucleotide sequencing of these two regions of the genome showed that each contained two tandemly arranged genes designated ACO1, ACO2, ACO3 and ACO4. Comparison of the nucleotide sequences of the cloned genomic regions with the cDNA clone pPHEFE indicated that ACO1 encoded the transcript in 4 exons interrupted by 3 introns. The other three members of the petunia ACC oxidase gene family shared identical intron numbers and positions with ACO1 and their exons were greater than 80% homologous. Nucleotide substitutions and deletions in the ACO2 gene indicate that it likely represents a pseudogene. Overall homology between ACO1 and ACO2 indicates that this gene cluster arose by a more recent duplication event than the gene duplication giving rise to the ACO3 and ACO4 cluster. The 5-flanking sequences share little overall homology between members of this gene family. However, sequences which likely make up the core promoter of these genes including the TATA box are highly homologous. RNA-based PCR amplification of ACC oxidase cDNAs from ethylene-treated corollas and wounded leaves revealed transcripts for ACO1, ACO3 and ACO4 indicating that a least three of these genes are transcriptionally active. The proteins encoded by ACO1, ACO3 and ACO4 share more than 90% identity with one another and more than 70% identity with ACC oxidases from other species. The ACC oxidase proteins share significant sequence homology with other enzymes that require Fe(II) and ascorbate for catalytic activity.

Amino Acid Oxidoreductases↗
PubMed1993

A mathematically designed STS primer without any mismatches for direct sequencing of cosmid DNA clones.

We report here a new method for the direct sequencing of large DNA inserts of cosmid clones from human chromosomes using STS primers of 14 nucleotides without any mismatches, which are designed from results of a mathematical analysis. It is clear that STS primer of 14 nucleotides is optimum for direct sequencing of cosmid recombinant DNA clones. We also provide examples of direct sequencing of cosmid clones of human chromosome 21 using these STS primers.

Animals↗
PubMed1993

[The effect of stimulating the auricular liver-gall point on the size of gallbladder of the rabbit].

After stimulating the auricular liver-gall point of rabbit with electrode. We observed marked contraction of gallbladder. Only one minute after stimulation, the contraction began. About ten minutes after stimulation the contraction was marked and the contraction lasted for 30-40 minutes. The average product of the length and width of gallbladder (15-25 minutes after stimulation) is markedly smaller than that of control (pre-stimulation). This result proves the liver-gall point of rabbit corresponds with its internal organ-gallbladder. The result also present a theoretic basis for clinical therapy of press over the auricular liver-gall point induced the excretion of gallstones.

Acupuncture Points↗
PubMed1993

[Quantitative study of transmitral flow by spectral Doppler echocardiography].

The aim of this study is to find an accurate and simple method for measuring the transmitral flow by pulsed Doppler echocardiography (PDE). Four parameters were measured: (1) anteroposterior dimension of the mitral valve annulus (MVA) (a); (2) mediolateral dimension of MVA (b); (3) a and b of MVA to calculate the area of MVA (elliptical method); (4) the area of the mitral valve orifice (MVO). The transmitral flow calculated by the use of (3) and (4) were compared with the aortic blood flow. The findings suggested that the MVA calculated with elliptical method is accurate and simple in measuring the transmitral flow.

Adolescent↗
PubMed1993

Endometrium-myometrium ratio: a newly proposed diagnostic parameter on magnetic resonance imaging assessment of myometrial invasion by endometrial cancer.

In order to improve the accuracy of magnetic resonance (MR) imaging assessment of myometrial invasion by endometrial cancer, the usefulness of a new diagnostic parameter, the endometrium-myometrium (EM) ratio has been evaluated. EM ratio is the proportion of the widest length of endometrium to the length of myometrium measured at the same line, this being vertical to the parallel of the long axis of the uterine body in the sagittal plane of the MR images. Myometrial invasion was defined as a value of the EM ratio > 1, and the tumor was limited to the endometrium for values < 1. In 25 consecutive patients, both the EM ratio-based assessment and the well-established junctional zone-based assessment with T2-weighted MR imaging and enhanced MR imaging with gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) were compared with the results from pathological examinations of postoperative specimens. In identifying myometrial invasion by endometrial cancer, the sensitivity of the EM ratio-based assessment was better than that of the junctional zone-based assessment. The overall sensitivity of the former was 96% in both the T2-weighted and enhanced MR imaging with Gd-DTPA, whereas that of the latter was 84% in the T2-weighted MR imaging and 72% (P < 0.05) in the enhanced MR imaging. The use of the EM ratio with MR imaging improves the ability to assess myometrial invasion by endometrial cancer.

Adult↗
PubMed1993

[Genotoxicity of herbicide 83-1 in yeast assay system].

The genotoxicity of Herbicide 83-1 (Dichloronitrophenolamide, DCNPA) was detected by the yeast D61.M and D7 assay with multi-endpoint. We noted that the frequency of cyhR (resistance to cycloheximide) colonies of D61.M treated with DCNPA on cycloheximide medium was much higher than that of the control (P < 0.01) and that there was a dose-response relationship. These showed that the positivity responsed to the mitotic crossing-over endpoint. To the remaining endpoints in the D61.M and D7 assay, however, the negative response was obtained. The results have demonstrated that Herbicide 83-1 is a DNA damage agent.

Benzamides↗