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Biomedical subjects

W Xu

Publications and source records attributed to W Xu.

At least 469 records · Page 26Linked to original sources
PubMed1995

[Influence of SmI lesion on acupuncture-induced analgesia in thalamic Pf neurons and effects of iontophoretic ACh on their nociceptive responses].

This study aimed to investigate the role of ACh in SmI emanating descending modulation of thalamic Pf neurons in acupuncture analgesia. Multi-micropipettes were used for both extracellularly recording responses of thalamic Pf neurons to noxious stimulation of the plantar area and drug application in rats. It was found that (1) lesion of SmI obviously attenuated the inhibitory effect of EA applied at "Zusanli" and "Huantiao" points on nociceptive responses in Pfneurons; (2) after lesion of SmI iontophoretic application of ACh markedly suppressed the nociceptive responses of Pf neurons, which was significantly different from the effect of iontophoretic NaCl (as the control) showing no influence on them; (3) the inhibition induced by iontophoretic ACh applied in the rats with lesion of SmI was similar to that produced by EA applied in those with SmI intact. It is indicated that EA can activate SmI to release ACh to exert descending modulation, in which ACh is involved in SmI originating descending regulation of Pf neruons in acupuncture analgesia.

Acetylcholine↗
PubMed1995

[The analgesic extensiveness and specificity of EA at different points on nociceptive response of trigeminal convergent neurons (TCN)].

Our privious work have demonstrated that eletroacupuncture (EA) at acupoints seemed to have no specific effects. The present work is to observe whether the analgesic extensiveness and specificity of EA at points is related to EA intensity and the sites of points. Experiments were carried out on rats anaesthetized with Urathane. The spontaneous discharges and nociceptive responses of convergent neurons on right trigeminal dorsl horn to noxious stimulation at receptive field (cheek) were recorded extracellarly with glass micro-electrode. EA was applied at ipsilateral "Xiaguan" (on face) or "Zusanli" (on shank) point with low (2V) and high (18V) intensity. The nociceptive response of TCN could be inhibited by low intensity EA applied at "Xiaguan" but not "Zusanli", showing the specificity of points. High intensity EA at either "Xiaguan" or "Zusanli" also reduced the responses, showing the analgesic extensiveness of points. We suggest that "the gate of control" mechanism plays an important role in low intensity EA and "DNIC" mechanism does so in high intensity EA. The results suggest that we must pay attention to the manipulation and the intensity of acupuncture in the clinic work.

Acupuncture Analgesia↗
PubMed1995

[p53 gene deletion and abnormal expression in gastric carcinoma].

We studied p53 gene at the DNA and protein level in human gastric cancer tissues and corresponding normal gastric mucosae from 20 cases of patients undergone radical surgery. By Southern blotting, the p53 gene was found to be partially deleted in 30% (6/20) of gastric cancer tissues. ABC immunohistochemical study of p53 expression was carried out on cryostat sections using monoclonal antibodies (PAb 1801) to p53. High level expression of mutated p53 protein was detected in 55% (11/20) gastric cancer tissues. The staining pattern was intranuclear and/or intracytoplamic. There was no detectable staining of any of the normal gastric tissues with 1801 antibody. The positive rate of p53 overexpression was higher in poorly-differenciated glandular carcinomas than well-differenciated cancer (P = 0.0116). Highly significant association exists between high level p53 expression and allele deletion (r = 0.59). The date indicate that inactivation of p53 gene is important in human gastric carcinogenesis and tumor progression. The assay of p53 gene structure and products may provide new biologically relevant tumor marks for predicting the behavior of gastric carcinomas, identifying more aggressive tumors, determining prognosis of the patients and guiding treatment.

Adenocarcinoma↗
PubMed1995

Metabolic approach for regulation of IL-1 beta in vivo.

IL-1 beta, the autoantibodies to IL-1 beta and IL-1 beta-containing immune complex in pleural effusion and cerebrospinal fluid were detected using anti-recombinant human IL-1 beta monoclonal antibody. The results indicate that IL-1 beta is detectable in some cases, and the amounts decrease gradually with the chemotherapy following the autoantibodies and the specific detectable immune complex. These autoantibodies may have a feedback effect, inhibiting the IL-1 beta activity, and forming the immune complex to speed the clearance of activated IL-1 beta.

Antibodies, Monoclonal↗
PubMed1995

[Inhibition of antisense DNA and its derivative on gastric transformed cell carcinogenicity].

In this study, an antisense c-Ha-ras DNA was synthesized. It was a complementary oligonucleotide chain to the sequence of initiation position of c-Ha-ras gene transcription. We found that the antisense DNA blocked the gene expression at the level of transcription and translation and partially reverted the malignant phenotyped of gastric transformed cells, including their growth rate, colonies formation in soft agar, tumorigenicity in nude mice and different grade. When the 5'-end of the antisense DNA was covalently linked with psoralen group, its biological effects were significantly enhanced. No effect of tumor inhibition was found in control oligonucleotide chains not complete complementary to the sequence of target gene. These results indicate that antisense DNA and its derivative are effective in tumor gene therapy.

Animals↗
PubMed1995

[A comparative study on the effect of absorbable components of several drugs on the growth and population doublings of rat diploid fibroblast].

Embryonic skin fibroblast of Sprague-Dawley rats cultivated in vitro was used in this experiment. The cultural medium was added with absorbable components of several drugs. The result reveals that Yan Shou recipe, vitamin E and Huan Jing Jian have conspicuous promotive effect on the growth of diploid fibroblast and also help to increase population doublings. The experiment suggests that all these drugs possess anti-aging effect on the skin diploid fibroblast of rats.

Aging↗
PubMed1995

[In vitro antibacterial activity of sulperazone on multi-resistant strains of bacteria from burn wounds].

Sulperazone (SLP), a combination of sulbactam (beta-lactamase inhibitor) with cefoperazone (CFP), was studied in vitro for its sensitivity to multi-resistant strains of bacteria isolated from burn wounds. The results showed that the sensitive rate of gram-negative bacteria to SLP was 77.3% (n = 163), higher than that of CFP (45.0%, n = 169) (P < 0.01). The rate of pseudomonas aeruginosa which was common among the gram-negative bacteria was 88.9% (n = 45), much higher than that of CFP (71.7%, n = 46) (P < 0.05). The rate of bacterium anitratum was 100%, and it was resistant to CFP (P < 0.01). The sensitive rate of gram-positive bacteria to SLP was 37.5% (n = 128) but to CFP was 24.6% (n = 126) (P < 0.05). The rate of staphylococcus aureus which was common in gram-positive bacteria was 42.6% (n = 61), much higher than that of CFP (21.3%, n = 61) (P < 0.05). It is indicated that sulbactam inhibits most beta-lactamases produced by common bacterial pathogens and makes antibiotics restore the sensitivity to resistant strains. Sulperazone is promising in the treatment of burn infection.

Anti-Bacterial Agents↗
PubMed1995

Human obesity does not segregate with the chromosomal regions of Prader-Willi, Bardet-Biedl, Cohen, Borjeson or Wilson-Turner syndromes.

Prader-Willi, Bardet-Biedl, Cohen, Borjeson and Wilson-Turner syndromes are genetic disorders characterized by obesity and other diverse abnormalities. These disorders have been mapped to their respective chromosomal regions, and we hypothesize that each region contains a gene or genes important in the regulation of body weight. We tested this hypothesis by genotyping sibling pairs (n = 207; 17 markers) from 44 families who were segregating an extreme obesity phenotype but were otherwise clinically normal. The number of alleles shared between siblings from these chromosomal regions did not correlate with similarity in body mass index (kg/m2). If genes in these regions contribute to non-syndromal obesity, the prevalence is low and the corresponding alleles are rare.

Adult↗
PubMed1995

[An investigation and design of apparatus for measuring fetal lung maturity].

Clinically, the authorized method for determing fetal lung maturity is the measurement of the ratio of surface-active L/S in amniotic fluid. To set up new, simple, rapid and accurate method, an apparatus for measuring fetal lung maturity was made. The paper describes the basic principle and working procedure of the apparatus. 148 amniotic fluid specimens from different pregnancies were measured by means of the apparatus. The result was compared with the L/S. The sensitivity of measurement was 95%, specificity 91%, and accuracy 93%. The operation of the apparatus is simple, convenient and rapid. A small quantity of amniotic fluid is needed. In conclusion, the expected result was attained. The apparatus is of great importance to clinical application.

Amniotic Fluid↗
PubMed1995

Mutations at three sites in the Escherichia coli 23S ribosomal RNA binding region for protein L11 cause UGA-specific suppression and conditional lethality.

A single nucleotide change, G to A, at nucleotide position 1093 of E. coli 23S ribosomal RNA was found to cause UGA-specific suppression (D.K. Jemiolo, F.T. Pagel and E.J. Murgola, Proc. Natl. Acad. Sci. USA, in press). To obtain new kinds of UGA-specific suppressors in 23S rRNA, we used segment-directed mutagenic PCR, and targeted first the 1405 nucleotide SnaBI/I-CeuI segment, which includes position 1093, of the rrnB operon cloned into a multicopy plasmid. The mutagenized fragments were subcloned into the plasmid vector and used to transform to ampicillin resistance (Ampr) a recipient strain containing a UGA mutation in trpA. The Ampr transformants were then screened for suppression of UGA. After purification, Trp+ transformants were tested for association of the suppressor phenotype first with the plasmid and then specifically with the SnaBI/I-CeuI fragment. In one screening, four different kinds of mutational change were found, all at three sites within a highly conserved hexanucleotide loop in domain II of 23S rRNA. This region is part of the site for binding of the large subunit protein L11, which has been shown to be involved in peptide chain termination in a specific way. All of the mutants (G1093A, G1093 delta, A1095 delta, and U1097 delta) suppress UGA mutations, but not UAA or UAG mutations, and all four types exhibit high-temperature conditional lethality when highly expressed. Several mechanisms can be suggested for the UGA-specific suppression exhibited by these mutants, including altered interaction with protein L11, Second-site mutations that overcome the conditional lethality of G1093A indicate that intramolecular interactions within 23S rRNA may play a role in peptide chain termination at the UGA stop codon.

Bacterial Proteins↗
PubMed1995

[p53 gene point mutation in human colorectal carcinoma].

We introduced two modified assay systems, PCR-SSCP and PCR-direct sequencing for the identification of structure aberration at p53 exon 7 in 22 colorectal carcinomas and 1 metastatic lymph node. The data indicated that 27.2% (6/22) colorectal carcinomas and one metastatic lymph node were shown to contain the point mutations in codons 245, 251, 259 and 260 of exon 7. One half of all the mutations was G:c to A:T transition in codon 245. Other mutation patterns were base insertion and deletion. All positive point mutations of p53 exon 7 existed in colon carcinomas in this study. The point mutation in p53 exon 7 was usually associated with poorly differentiated primary carcinomas (P = 0.0178) and the mutation rate of was higher in Duckes C stage of the disease than in stage Duckes A and B (P = 0.0361). Thus p53 exon 7 point mutation in primary colorectal tumors and regional lymph nodes may identity a subgroup of colorectal cancer patients with more aggressive disease and may be as a new tumor markers for assessing the prognosis of colorectal carcinomas.

Adult↗
PubMed1995

[Total pelvic exenteration for local advanced rectal carcinoma: analysis of 20 patients].

20 patients of total pelvic extenteration (TPE) were performed from 1989 to 1995 for local advanced rectal carcinoma. The incidence of operative complications was 65% with a mortality of 5%. 19 patients were followed up for 3-42 months, 7 patients died with an average life-span of 14.1 months. It seemed to us that the results of conservative therapy was usually disappointing for local advanced rectal carcinoma and and TPE is the better management of choice for relieving patient's symptoms and improving their survival rates.

Adenocarcinoma↗
PubMed1995

[Hemodynamic study of distal splenorenal shunt (DSRS)].

Color-flow Doppler sonography (FDS) was used for assessing the hemodynamic changes in 8 patients undergoing distal splenorenal shunt (DSRS). Results were compared with 14 patients with portal-azygos disconnection (PAD). It was found that 3 weeks after DSRS portal venous flow (PVF) decreased by 50%, and at least in some patients the reduction of the PVF was a continuous process during the period of two years in the DSRS group. The postoperative decrease in PVF in DSRS patients was in sharp contrast to that in PAD patients (P < 0.001), hence PAD is superior to DSRS in remaining satisfactory PVF.

Adult↗
PubMed1995

[Medicinal plant resources of Berberis L. in Guizhou province].

Based on field investigation and identification of 19 species and one variety of medicinal plant of Berberis produced in Guizhou Province, it has been found out that among these species 3 is found to be new ,4 species and one variety are discovered for the first time in Guizhou province. Geographical distribution, perpendicular distribution and medicinal uses of these species are spelled out and a key for their identification is given.

China↗
PubMed1995

[Influence of microiontophoretic morphine on nociceptive responses of Pf neurons after lesion of SmI].

Neuronal responses in thalamic nucleus parafasciculus (Pf) to microiontophoretic morphine were examined in 20 wistar rats after lesion of SmI. Extracellular recordings were made with five-barreled glass microelectrodes. The results showed that the spontaneous responses of Pf neurons were not statistically changed (n = 11, P > 0.05), but their nociceptive responses were attenuated at 0-8 minutes after iontophoretic morphine (n = 11, P < 0.05). There were statistically significant differences in nociceptive responses between morphine and saline groups at 0-8 minutes after iontophoresis. The results suggest that morphine may be involved in corticofugal modulation of nociceptive responses in thalamic Pf neurons.

Animals↗
PubMed1995

[Cloning of the diapause hormone gene of the silkworm (Bombyx mori)].

A silkworm genomic library was screened with radiolabelled cDNA of Bombyx mori diapause hormone (Bom DH). Three positive clones were isolated from approximately 4 x 10(5) plaques, and subjected to further analyses. The DNA inserts excised from positive clones with SalI were ligated into pBluescript KS(+) vector and grown in E. coli XL1 cells. The DNA fragments obtained by EcoRI digest form the insert were subcloned into the same vectors. The nucleotide sequence analysis showed that these clones involved the Bom DH gene. Genomic Southern analysis suggested that the Bom DH is encoded by a single gene. The present study which is the first one on cloning of the Bom DH gene.

Animals↗
PubMed1994

The tsA58 simian virus 40 large tumor antigen disrupts megakaryocyte differentiation in transgenic mice.

Thrombocytopenia is a condition of multiple etiologies affecting the megakaryocyte lineage. To perturb this lineage in transgenic mice, the tsA58 mutation of the simian virus 40 large tumor antigen was targeted to megakaryocytes using the platelet factor 4 promoter. Ten of 17 transgenic lines generated exhibited low platelet levels, each line displaying a distinct, heritable level of thrombocytopenia. Within a line, the degree of the platelet reduction correlated directly with transgene zygosity. The platelet level could be further reduced by the inactivation of one copy of the endogenous retinoblastoma gene. Western blot analysis detected large tumor antigen protein in the most severely affected lines; less affected lines were below the level of detection. Platelets and megakaryocytes from thrombocytopenic mice exhibited morphological abnormalities. Mice with either normal or reduced platelet levels developed megakaryocytic malignancies with a mean age of onset of about 8 months. There was no correlation between severity of thrombocytopenia and onset of malignancy. These mice provide a defined genetic model for thrombocytopenia, and for megakaryocytic neoplasia, and implicate the retinoblastoma protein in the process of megakaryocyte differentiation.

Animals↗