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Biomedical subjects

X Yang

Publications and source records attributed to X Yang.

At least 1,027 records · Page 57Linked to original sources
PubMed1994

[Detection of B-cell clonality in paraffin-embedded bone marrow biopsy specimens by polymerase chain reaction].

In order to estimate the clonality of B-cell lymphoproliferative disorders, polymerase chain reaction (PCR) was used to detect the Ig heavy chain gene rearrangement in DNA extracted from formalin-fixed and paraffin-embedded bone marrow biopsies. 16 out of 19 cases (84%) of B-CLL (n = 9), multiple myeloma (n = 7) and B-non-Hodgkin's lymphoma (n = 3) showed sharp monoclonal bands, while polyclonal smears or no PCR-products were observed in non-neoplastic bone marrow or AML specimens. The results showed that the DNA from paraffin-embedded bone marrow biopsies could be used to detect monoclonal IgH rearrangement by PCR method. This forms the basis for the studies of minimal residual disease or B-ML bone marrow infiltrated diseases.

Biopsy↗
PubMed1994

[A study of method of repair of defects of nasal tip and ala].

Since 1957, the authors repaired 119 cases of nasal tip and alar defects using four kinds of method: (1) 27 cases by full-thickness skin graft; (2) 36 cases by free auricular composite graft; (3) 12 cases by local skin flap; (4) 44 cases by upper arm tube flap. The operation method was selected according to the size of nasal defect, available quantity of the remnant nasal tip and ala, and the soft tissue around the defect. The following problems were discussed in detail: (1) the principles of the selection of repairing method; (2) operative procedure; (3) the key points for the repair of nasal defects.

Burns↗
PubMed1994

[Study on urine ALb, serum and urine beta 2-m, IgG, and THP].

The urine ALb, serum and urine beta 2-m, IgG, and THP were serially determined with radioimmunoassay to assess the renal functions during various stages of burn in 52 patients with TBSA over 30% (mean +/- s 58.4% +/- 18.88%). It was found that the urine levels of ALb, IgG, and THP and the serum and urine levels of beta 2-m were remarkably increased and that the serum levels of IgG were decreased after burns. Our study suggested that the measurements of urine ALb, serum and urine beta 2-m, IgG, and THP using radioimmunoassay were sensitive in assessing renal glomerular permeability and tubular functions after burn. It is presumed that such methods might be used to help identify the location, the extent, and the severity of the renal abnormalities and provide valuable information about the differential diagnosis and the prognosis of the renal damage in patients with extensive burns.

Adolescent↗
PubMed1994

[Studies of the suppressive effect of cDNA RA538 on three human cancer cell lines].

As previously reported, transfer of RA538 into parental esophageal cancer EC8712 cell line induced its terminal differentiation and apoptosis. To further study the biological effects of this cDNA, an expression plasmid containing an insert of the putative coding fragment (about 0.3kb) of RA538 and neo resistance gene was constructed (designated pRA538-0.3-neo) and transferred into three different human cancer cell lines: EC8712, HL60 and GLC, a cell line derived from an adenocarcinoma of the lung. After selection in G418-containing culture media, the growth rate, 3H-thymidine incorporation rate, cell morphology, colony-formation in soft-agar, and heterotransplantation into nude mice of the surviving cell populations were tested. In situ hybridization verified the uptake and expression of the 0.3kb fragment of RA538 in these G418 resistant cell populations. Significant reduction in growth rate and suppression of malignant phenotype were observed in all these cells in comparison with their parental cancer cell lines.

Adenocarcinoma↗
PubMed1994

[Expression of cDNA RA538 induces terminal differentiation and apoptosis of its parental malignant cell line in vitro].

A full-length cDNA (RA538) was isolated from human esophageal cancer cell line EC8712 after retinoic acid treatment. An expression vector of this cDNA (pRA538) was cotransfected with the neo gene (pDORneo) into parental cancer cell line EC8712. The cell colonies obtained after selection in G418-containing culture medium showed very poor growth, reduced (by 68%-76%) 3H-TdR uptake and morphological changes characteristic of terminal differentiation and programmed cell death (apoptosis). In situ hybridization with RA538 probes revealed expression of mRNA of RA538 in the cytoplasm of the transfected cells. The cells transfected solely with pDORneo after G418 selection showed normal growth pattern and no RA538 expression. However, none of the control cells EC8712 survived the G418 selection. Thus the expression of cDNA RA538 has a similar effect on the esophageal cancer cell EC8712 as the retinoic acid does.

Animals↗
PubMed1994

A sensitivity analysis of repeat migration attrition in the study of migrant adjustment: the case of Bangkok.

Studies of migrant adjustment often conclude that results apply only to remaining migrants. This paper examines the potential bias in using the difference between remaining migrants and natives as a measure of migrant adjustment. The results document that differences between remaining migrants and natives contain bias caused by attrition due to repeat migration. Such bias is small, however, and is unlikely to change migrant-native comparisons. Unless one is concerned with details of differences between migrants and natives, it is unnecessary to be concerned about migration attrition bias in drawing conclusions from the observed differences.

Adult↗
PubMed1994

Fusion expression vectors for recombinant gene products processed easily and purified rapidly by affinity chromatography.

A DNA fragment encoding IgG-binding domain B,C (PABC) was separated from protein A gene, cloned into phage M13 and modified by oligo-directed mutagenesis at the hydroxylamine-cleaved site from Asn-Gly to Asn-Ala in domain B and C, respectively. The modified PABCm gene fragment was used to construct one set of fusion expression vectors in different reading frames. Processing sequences such as those recognized by enterkinase, collagenase, thrombin, activated factor X and cleaved by the hydroxylamine, N-chlorosuccinimide etc. can be created in the fusion site. Using the above vectors, fusion proteins such as PABCm-IGF-I, -hGRF, -bGRF and their derivatives were highly expressed in E. coli. The yield of fusion proteins is over 100 mg per liter cultured by analysis of SDS-PAGE. The PABC fusion proteins can be rapidly purified by the affinity chromatography with a IgG-sepharose column.

Base Sequence↗
PubMed1994

[Reconstruction of eyebrows by superficial temporal artery island flap (clinical analysis of 34 cases)].

The authors used the superficial temporal artery island flap in 34 cases for the reconstruction of the defective eyebrows and obtained good results. The present article introduces the operation technic and the following problems were discussed in detail: how to keep the grafted island flap survive; how to maintain the configuration of the reconstructed eyebrows; the principles of the operation designs.

Adolescent↗
PubMed1994

Effect of chronic central treatment with the acetylcholine analog methylcarbamylcholine on cortical nicotinic receptors: correlation between receptor changes and behavioral function.

Chronic administration of nicotine results in increased numbers of specific nicotinic acetylcholine receptors (nAChRs) within the central nervous system. The purpose of this study was to determine: 1) whether chronic administration of the nicotinic agonist, methylcarbamylcholine (MCC) or the competitive antagonist dihydro-beta-erythroidine (DHBE) in rats could alter brain nAChRs; 2) whether DHBE could inhibit the alterations produced by MCC and 3) whether such changes could be correlated with alterations in animal behavior. MCC (3-60 micrograms) or DHBE 6 or 60 micrograms) alone, or DHBE 15 min preceding MCC (30 micrograms) was injected via previously implanted i.c.v. guide cannulas, twice daily for 10 days. Chronic administration of MCC reversibly increased the apparent Bmax and Kd of cortical nAChRs in a dose- and time-dependent manner. Chronic central administration with DHBE also increased Bmax. Chronic i.c.v. pretreatment with DHBE inhibited the elevation in Bmax and Kd produced by chronic MCC injection. In freely behaving animals, MCC evoked the expression of a characteristic posture assumed in response to central nicotinic stimulation. Chronic administration of MCC resulted in tolerance to this behavioral response. DHBE pretreatment inhibited the MCC-induced behavioral changes. The time course of the development of tolerance to MCC as well as the extent of inhibition of DHBE were well correlated with the time course for receptor up-regulation and inhibition of the increase in binding parameters, respectively. Like chronic MCC treatment, chronic DHBE increased the number of [3H]cytisine binding sites but without concomitant development of behavioral tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Difference in the distribution and content of nucleolar protein B23 between interphase and mitotic HeLa cells].

Protein B23 is one of the two major protein components in eukaryocytic nucleolus. Previous studies indicate that the cellular content and distribution of protein B23 are correlated with the synthetic rate of ribosomal RNA (rRNA) and cell growth. It is more abundant in tumor and growing cells than in normal resting cells. It may translocate from nucleolus to nucleoplasm after serum deprivation, or after being treated with RNA inhibitors such as actinomycin D, toyocamycin, or doxorubicin. In order to search for the role of protein B23 in cell division, using an anti-B23 monoclonal antibody, we detect the cellular content and distribution of protein B23 in interphase and mitotic HeLa cells, respectively. Two microtubule drugs, colcemid and taxol, are used to arrest the mitotic cells. The results show the cellular content of protein B23 in mitotic cells is much higher than that in interphase cells. The intracellular distribution of protein B23 in mitotic cells is distinguished from that in interphase cells too.

Blotting, Western↗
PubMed1994

[Studies on the relationship between HPV and respiratory tract tumors. I. Correlation between HPV and laryngeal carcinoma].

In this paper, alpha-32P-dCTP-labeled HPV-11 and HPV-16 DNA were used as probe, and slot and Southern blot hybridization techniques were used to detect HPV-11 and HPV-16 DNA related sequences in 37 laryngeal carcinoma tissues taken from patients in Qingdao and Beijing. Using the slot blot technique, 86% (32/37) of the cases showed positive hybridization with HPV-11 probe, while 81% (30/37) showed positive results with HPV-16. Another 81% (30/37) showed positive hybridization with HPV-11 and HPV-16 simultaneously. Using Southern blot hybridization Pst digestion, the hybridization pattern corresponded to that of HPV-16 in 46; (13/28), and none corresponded to HPV-11. The results suggest that HPV-16 may induce laryngeal carcinoma.

Adult↗
PubMed1994

Schistosomiasis control in China.

Well-organized programmes combining local involvement and major government projects have been successful in controlling schistosomiasis to a large extent in China. The task is far from complete, however, especially in some lacustrine and mountainous areas, where conditions are highly favourable for the vector snails, and difficult to modify. A long-term programme of health education, medical care and infrastructure development is needed.

Animals↗
PubMed1994

[Investigation of the form of onset in 139 cases of insulin-dependent diabetes mellitus].

A retrospective study of 139 cases of IDDM patients (male 54 cases, female 85 cases) were investigated. Average age 31.74 +/- 12.20 yr. One third of all patients had virus infection before the onset of IDDM and the infection in upper respiratory system and intestine occupied most of the cases (85%). In two cases, the onset of the disease was induced after BCG vaccination. There is no relationship between virus infection and the occurrence of DKA as primary form of onset. The average age in the group of positive virus infection is significantly younger than in the group of negative virus infection (P < 0.02). About one fourth of all cases had positive family history of diabetes which is much higher than the similar reports in Western countries.

Adolescent↗
PubMed1994

[Chemiluminescent immunoassay for anti-granulocyte antibody IgG].

In this paper is reported solid phase competitive chemiluminescent immunoassay (CLIA) for anti-granulocyte antibody (AGAb) IgG with N-(4-amiobytul)-N-ethylisoluminol (ABEI) labelled rabbit antibody IgG against granulocyte competing with the analyte and ABEI-CoCl2-H2O2 as the chemiluminescent system. The absolute limit of detection was 3.0 x 10(-14) mol ABEI/tube. One hundred and thirty one individuals were divided into three groups: leukocytopenic group (n = 58), control group (n = 41) and normal group (n = 32). Chemiluminescent index (CLI) was used as the diagnostic criterion for AGAb in serum. The results showed that the positive rate of the leukocytopenic group was significantly higher than that of the control group (P < 0.005), and the sensitivity, specificity and accuracy of the method were 43.1%, 90.2% and 62.6%, respectively.

Granulocytes↗
PubMed1994

Clinical observation on needling extrachannel points in treating mental depression.

Totally 20 cases of mental depression were treated by needling extrachannel points with an effective rate of 90%; comparison of these cases with 21 controls treated with amitriptyline, showed no significant difference in effect (P > 0.05). Measured with Hamilton's scale, factors of anxiety somatization, cognitive disturbance, retardation, sleep disturbance and feeling of despair in both the needling and control groups showed obvious decrease in the mean value, and the change in anxiety somatization was markedly significant in the needling group as compared with that in the controls (P < 0.01). Our studies revealed that after 6 weeks of needling the power of slow wave delta decreased while that of the fast wave alpha increased, all significantly different as compared with that before and during the treatment (P < 0.05).

Acupuncture Points↗
PubMed1993

Alternative splicing in a novel tyrosine phosphatase gene (DPTP4E) of Drosophila melanogaster generates two large receptor-like proteins which differ in their carboxyl termini.

A novel Drosophila receptor-like protein tyrosine phosphatase gene, DPTP4E, was isolated and characterized. DPTP4E, located at cytological position 4E1-2, is comprised of 10 exons; its RNA products are widely expressed during embryonic development, including the developing central nervous system. DPTP4E produces three major developmentally regulated transcripts of 6.5, 7.0, and 7.5 kilobases. The two major embryonic transcripts arise as the result of the alternative splicing of exon IX; as a consequence, two proteins (200 and 183 kDa) are produced which differ in their carboxyl-terminal sequences. The deduced extracellular domain, which lies between two putative hydrophobic transmembrane segments, contains 11 fibronectin type III-like repeats and 25 putative N-glycosylation sites. A single conserved protein tyrosine phosphatase (PTPase) catalytic domain, which shows a high level of amino acid identity to the Drosophila PTPase DPTP10D and human HPTP beta, is found in the predicted intracellular domain; this PTPase domain, when expressed as a fusion protein in Escherichia coli, exhibits PTPase activity. The possible implications of these findings are discussed.

Alternative Splicing↗
PubMed1993

Expression and novel subunit isoforms of glutamate receptor genes GluR5 and GluR6.

Molecular heterogeneity of kainate-selective glutamate receptor subunits GluR5 and GluR6 was revealed by identification of a human cDNA, GluR5-1d, and a murine cDNA, GluR6-2, that each encode subunits with novel carboxy-terminal sequences. Both GluR5-1d and GluR6-2 appear to be generated by alternative splicing at analogous sites 14 codons following the fourth putative transmembrane segment. The principal transcripts of GluR5 and GluR6 were detected by Northern analyses of several regions of mammalian brains as 4 and 6 kb bands, respectively. Potential roles for these receptors in development are indicated by detection of their mRNAs in mouse embryos of 11 days gestation. These findings add to the description of the remarkable diversity of glutamate receptor gene expression.

Amino Acid Sequence↗