Biomedical subjects

W Yan

Publications and source records attributed to W Yan.

At least 73 records · Page 4Linked to original sources

PubMed2000

[Evaluation of autonomic nervous function with heart rate variability and cardiovascular reflex tests in type II diabetes mellitus patients].

OBJECTIVE: To evaluate autonomic nervous function in simple diabetes mellitus patients, diabetic nephropathy(DN) patients and diabetes mellitus patients with accompanying coronary heart disease(DC) by studying heart rate variability (HRV) and cardiovascular reflex tests. METHODS: 57 type II diabetes mellitus patients were divided into 3 groups: 29 of simple diabetes mellitus, 17 of DC, and 11 of DN. The three groups were matched to 15 healthy controls for age, HRV and three cardiovascular reflex tests were performed in all the patients. RESULTS: The overall frequency of abnormal autonomic nervous function in 57 diabetes mellitus patients was 45.6%. All the diabetes mellitus groups especially the DN group were lower than a normal control group in time domain indexes and nonlinear dynamics indexes. As the patterns of R-R interval Poincare plots were concerned, the control group was mainly of comet-shaped pattern, the simple diabetes mellitus group was mainly of torpedo-shaped pattern, while the DN group and the DC group had more irregular patterns. CONCLUSION: Decrease in HRV is an early clinical marker for evolving diabetic autonomic neuropathy. This method may be helpful for evaluating organ dysfunction in diabetes mellitus patients.

Adult↗

PubMed2000

Epidemiology of human ancylostomiasis among rural villagers in Nanlin County (Zhongzhou Village), Anhui Province, China: II. Seroepidemiological studies of the age relationships of serum antibody levels and infection status.

Anti-hookworm antibody serologic responses were measured in residents of an Anhui provincial Chinese village where Ancylostoma duodenale is the predominant hookworm. Antibody responses were measured against either soluble infective third-stage larval (L3) or adult antigens. Immunoglobulins of the IgG class, especially IgG4 correlated with both the prevalence and intensity of A. duodenale hookworm infections. In contrast, there was an inverse correlation with IgM, but no correlation with IgA or IgE. Circulating IgG4 antibody responses might serve as a surrogate marker for active A. duodenale hookworm infection.

Ancylostomiasis↗

PubMed2000

[Treatment of acute lymphoblastic leukemia by autologous stem cell transplantation: an analysis of 30 cases].

OBJECTIVE: To evaluate the clinical outcome of autologous stem cell transplantation (ASCT) in acute lymphoblastic leukemia (ALL) and the affected factors. METHODS: Data of 30 ALL patients received ASCT in our hospital between July 1987 and December 1997 were retrospectively analyzed. Twenty-four of them were in the first complete remission (CR(1)) and six in the second complete remission (CR(2)) or early relapse (ER). Conditioning regimens were CTX 120 mg/kg + single total body irradiation 9 - 10 Gy (sTBI) or Bu 16 mg/kg of Mel 140 - 180 mg/m(2) + Ara-c 2 - 4 g/m(2). RESULTS: All patients reconstituted hematopoiesis. The median follow-up duration was 504 (18-3043) days. Transplant-related mortality was 10%. The probabilities of 3 year disease-free survival (DFS) for ALL in CR(1) and CR(2) were 67.7% +/- 10.3% and 16.7% +/- 15.2%, respectively (P = 0.00547); the 3 year DFS was significantly better with posttransplant treatment than without it (92.3% +/- 7.4% vs 50.0% +/- 17.7%, P = 0.0130). CONCLUSION: Acute lymphoblastic leukemia patients without HLA-matched related donor are recommended for ASCT in CR(1). To reduce relapse and improve the outcome, adoptive immunotherapy or maintenance chemotherapy should be given after ASCT.

Adolescent↗

PubMed2000

[The impact of hepatitis B virus infected patients or donors on the outcome of hematopoietic stem cell transplantation].

OBJECTIVE: To investigate the impact of recipients and/or donors infected with hepatitis B on the outcome of hematopoietic stem cells transplantation (HSCT). METHODS: We analyzed retrospectively the transplantation outcome in 26 of 164 hematological diseases patients who and whose donors were infected with hepatitis prior to transplantation. RESULTS: (1) Three of the 26 patients developed VOD after HSCT, the incidence (11.5%) is significant higher than that in patients and donors who did not infected with HBV (P < 0.05). (2) Two of 5 patients transfused hematopoietic stem cells from HBsAg + donors developed hepatitis B. (3) Four patients with allogeneic stem cell transplantation developed hepatic failure (HF) which occurred during cyclosporin (CsA) being tapered off or withdrawal. The incidence of HF in patients and/or donors infected with HBV (15.4%) is obviously higher than that in patients and donors who did not (0.08%, P < 0.01). (4) In 4 patients with HbeAg +, 2 patients died of HF after allogeneic HSCT, the other 2 patients survived after autologous HSCT. CONCLUSION: Donors and recipients infected with hepatitis B are not contraindication of HSCT, but patients with allogeneic HSCT are in danger to develop LF during CsA being tapered off or withdrawal.

Adolescent↗

PubMed2000

[The expression and mechanism study of BMP in pleomorphic adenoma].

OBJECTIVE: One important pathological character of pleomorphic adenomas is that there is chorndriod component in the epithelial tumors. It is well known that bone morphogenetic protein (BMPs) plays important roles in the morphogenesis of hard tissue by inducing mesenchymal cells to differentiate into osteoblasts and chondroblasts in vivo. So we examined the expression of BMP and BMP2 mRNA in pleomorphic adenomas to study the pathological mechanism of chorndriod tissue formation. METHODS: Using ABC immunohistochemistry method, 6 specimens of pleomorphic adenomas were examined with BMP antibody. Reverse transcriptase-polymerase chain reaction (RT-PCR) methods were developed for detecting BMP2 mRNA expression with special primers used to amplify the BMP2 cDNA mature domain fragment. The total RNA was extracted from frozen 6 specimens of pleomorphic adenoma and then reversed to cDNA by reverse transcription using AMV reverse transcriptase. PCR conditions were 94 degrees C for 20 seconds, 60 degrees C for 30 seconds, and 72 degrees C for 1 minute, 40 cycles, followed by extension for 30 minute at 72 degrees C. The reaction products were analyzed by electrophoresis. RESULTS: BMP expression could be found in all of the specimens of pleomorphic adenoma examined by immunohistochemistry method. BMP2 RT-PCR product was detected in only 5 specimens that showed BMP2 mRNA existed in 5 specimens. CONCLUSION: These results may be helpful to study the mechanism of pleomorphic adenoma. It is speculated that BMP secreted by tumor cells may play important roles in origin of osteoid tissue in pleomorphic adenoma by inducing neoplastic myoepithelial cells to differentiate to chondrocytes.

Adenoma, Pleomorphic↗

PubMed2000

[Value of condensation and rarefaction click evoked action potential latency difference in the diagnosis of Meniere's disease].

OBJECTIVE: To study the value of condensation and rarefaction clicks evoked action potential (AP) latency difference (LD) in diagnosis of Meniere's disease. METHODS: AP was recorded with ECochG in controls (50 ears) and patients with Meniere's disease(90 ears) and sensorineural hearing loss(SNHL) of other origins(60 ears). LD was calculated and analyzed. RESULTS: LD in patients with Meniere's disease was (0.30 +/- 0.15) ms, which was significantly larger than that of controls(0.18 +/- 0.07) ms and of patients with SNHL of other origins(0.20 +/- 0.10) ms (P < 0.01). In the group of Meniere's disease, LD in patients with the mild and moderate hearing impairment was larger than those with severe hearing loss(P < 0.01) and LD in patients with low tone or high tone auditory sensation curve was larger than those with flat auditory sensation curve(P < 0.01). Positive rate was 4/60(6.7%) in other SNHL patients and 58/90(64.0%) in Meniere's disease group respectively. CONCLUSION: The increase in condensation and rarefaction click evoked AP latency difference can be an objective parameter in diagnosis of Meniere's disease.

Action Potentials↗

PubMed1999

Trypanosoma cruzi contains major pyrophosphate stores, and its growth in vitro and in vivo is blocked by pyrophosphate analogs.

High field (31)P nuclear magnetic resonance spectroscopy showed that inorganic pyrophosphate (P(2)O(7)(4-)) is more abundant than ATP in Trypanosoma cruzi, the causative agents of Chagas' disease. These results were confirmed by specific analytical assays, which showed that in epimastigotes, the concentrations of inorganic pyrophosphate and ATP were 194.7 +/- 25.9 and 37.6 +/- 5.5 nmol/mg of protein, respectively, and for the amastigote form, the corresponding concentrations were 358.0 +/- 17.0 and 36.0 +/- 1.9 nmol/mg of protein. High performance liquid chromatographic analysis of perchloric acid extracts of epimastigotes labeled for 3 h with (32)P-orthophosphate showed a significant incorporation of the precursor into inorganic pyrophosphate. Inorganic pyrophosphate was not uniformly distributed in T. cruzi but was shown by (31)P-NMR and chemical analysis to be particularly associated with acidocalcisomes, organelles shown previously to contain large amounts of phosphorus and various elements. Electron microscopy analysis of pyrophosphatase-treated permeabilized epimastigotes showed disappearance of the electron density of the acidocalcisomes. Nonmetabolizable analogs of pyrophosphate, currently used for the treatment of bone resorption disorders, selectively inhibited the proliferation of intracellular T. cruzi amastigotes and produced a profound suppression in the number of circulating trypomastigotes in mice with an acute infection of T. cruzi, offering a potentially new route to chemotherapy.

Animals↗

PubMed1999

Id1 and Id3 are required for neurogenesis, angiogenesis and vascularization of tumour xenografts.

Id proteins may control cell differentiation by interfering with DNA binding of transcription factors. Here we show that targeted disruption of the dominant negative helix-loop-helix proteins Id1 and Id3 in mice results in premature withdrawal of neuroblasts from the cell cycle and expression of neural-specific differentiation markers. The Id1-Id3 double knockout mice also display vascular malformations in the forebrain and an absence of branching and sprouting of blood vessels into the neuroectoderm. As angiogenesis both in the brain and in tumours requires invasion of avascular tissue by endothelial cells, we examined the Id knockout mice for their ability to support the growth of tumour xenografts. Three different tumours failed to grow and/or metastasize in Id1+/- Id3-/- mice, and any tumour growth present showed poor vascularization and extensive necrosis. Thus, the Id genes are required to maintain the timing of neuronal differentiation in the embryo and invasiveness of the vasculature. Because the Id genes are expressed at very low levels in adults, they make attractive new targets for anti-angiogenic drug design.

Animals↗

PubMed1999

tRNA discrimination at the binding step by a class II aminoacyl-tRNA synthetase.

Aminoacyl-tRNA synthetases preserve the fidelity of decoding genetic information by accurately joining amino acids to their cognate transfer RNAs. Here, tRNA discrimination at the level of binding by Escherichia coli histidyl-tRNA synthetase is addressed by filter binding, analytical ultracentrifugation, and iodine footprinting experiments. Competitive filter binding assays show that the presence of an adenylate analogue 5'-O-[N-(L-histidyl)sulfamoyl]adenosine, HSA, decreased the apparent dissociation constant (K(D)) for cognate tRNA(His) by more than 3-fold (from 3.87 to 1.17 microM), and doubled the apparent K(D) for noncognate tRNA(Phe) (from 7.3 to 14.5 microM). By contrast, no binding discrimination against mutant U73 tRNA(His) was observed, even in the presence of HSA. Additional filter binding studies showed tighter binding of both cognate and noncognate tRNAs by G405D mutant HisRS [Yan, W., Augustine, J., and Francklyn, C. (1996) Biochemistry 35, 6559], which possesses a single amino acid change in the C-terminal anticodon binding domain. Discrimination against noncognate tRNA was also observed in sedimentation velocity experiments, which showed that a stable complex was formed with the cognate tRNA(His) but not with noncognate tRNA(Phe). Footprinting experiments on wild-type versus G405D HisRS revealed characteristic alterations in the pattern of protection and enhancement of iodine cleavage at phosphates 5' to tRNA nucleotides in the anticodon and hinge regions. Together, these results suggest that the anticodon and core regions play major roles in the initial binding discrimination between cognate and noncognate tRNAs, whereas acceptor stem nucleotides, particularly at position 73, influence the reaction at steps after binding of tRNA.

Adenosine↗

PubMed1999

RGD-CAP ((beta)ig-h3) enhances the spreading of chondrocytes and fibroblasts via integrin alpha(1)beta(1).

In previous studies, RGD-CAP (collagen-associated protein containing the RGD sequence) isolated from a collagen fiber-rich fraction of pig cartilage was found to be orthologous to human (beta)ig-h3, which is synthesized by lung adenocarcinoma cells in response to transforming growth factor-beta. In the present study, we examined the effect of recombinant chick RGD-CAP on the spreading of chondrocytes and fibroblasts using RGD-CAP-coated dishes. When rabbit articular chondrocytes, chick embryonic sternal chondrocytes, rabbit peritoneal fibroblasts or human MRC5 fibroblasts were seeded on plastic dishes coated with RGD-CAP, cell spreading was enhanced compared with that on control dishes (bovine serum albumin- or beta-galactosidase-coated dishes). The effect of RGD-CAP on the cell spreading required divalent cations (Mg(2+) or Mn(2+)), and was reduced by EDTA. Monoclonal antibodies (mAbs) to the human integrin alpha(1) or beta(1) subunit, but not to the alpha(2), alpha(3), alpha(5) or beta(2) subunits, suppressed the RGD-CAP-induced spreading of human MRC5 fibroblasts. In a parallel experiment, the mAb to the alpha(5) subunit, but not the mAb to the alpha(1) subunit, suppressed fibronectin-induced spreading of these cells. These findings suggest that RGD-CAP is a novel ligand for integrin alpha(1)beta(1) that dose not bind to the RGD motif. Accordingly, an RGD-CAP fragment, which carries a deletion in the C-terminal region containing the RGD motif, was still capable of stimulating cell spreading.

Animals↗

PubMed1999

Corin, a mosaic transmembrane serine protease encoded by a novel cDNA from human heart.

A novel cDNA has been identified from human heart that encodes an unusual mosaic serine protease, designated corin. Corin has a predicted structure of a type II transmembrane protein and contains two frizzled-like cysteine-rich motifs, seven low density lipoprotein receptor repeats, a macrophage scavenger receptor-like domain, and a trypsin-like protease domain in the extracellular region. Northern analysis showed that corin mRNA was highly expressed in the human heart. In mice, corin mRNA was detected by in situ hybridization in the cardiac myocytes of the embryonic heart as early as embryonic day (E) 9.5. By E11.5-13.5, corin mRNA was most abundant in the primary atrial septum and the trabecular ventricular compartment. Expression in the heart was maintained through the adult. In addition, mouse corin mRNA was also detected in the prehypertrophic chrondrocytes in developing bones. By fluorescent in situ hybridization analysis, the human corin gene was mapped to 4p12-13 where a congenital heart disease locus, total anomalous pulmonary venous return, had been previously localized. The unique domain structure and specific embryonic expression pattern suggest that corin may have a function in cell differentiation during development. The chromosomal localization of the human corin gene makes it an attractive candidate gene for total anomalous pulmonary venous return.

Amino Acid Sequence↗

PubMed1999

Dentate granule cell function after neonatal treatment with parachloroamphetamine or 5,7-dihydroxytryptamine.

In vitro, extracellular electrophysiological recording was used to test granule cell responses in P60 rats after neonatal PCA and 5, 7-DHT. Granule cell population EPSP and spike responses were in the normal range for both PCA and 5,7-DHT groups. However, the degree of paired pulse facilitation was reduced in both of these groups relative to control, reflecting a diminished synaptic drive. Synaptic potentiation in the 5,7-DHT group was not different from control, but was significantly reduced in slices from PCA-treated rats.

5,7-Dihydroxytryptamine↗

PubMed1999

Enhancement of cell adhesion and spreading by a cartilage-specific noncollagenous protein, cartilage matrix protein (CMP/Matrilin-1), via integrin alpha1beta1.

Cartilage matrix protein (CMP; also known as matrilin-1), one of the major noncollagenous proteins in most cartilages, binds to aggrecan and type II collagen. We examined the effect of CMP on the adhesion of chondrocytes and fibroblasts using CMP-coated dishes. The CMP coating at 10-20 micrograms/ml enhanced the adhesion and spreading of rabbit growth plate, resting and articular chondrocytes, and fibroblasts and human epiphyseal chondrocytes and MRC5 fibroblasts. The effect of CMP on the spreading of chondrocytes was synergistically increased by native, but not heated, type II collagen (gelatin). The monoclonal antibody to integrin alpha1 or beta1 abolished CMP-induced cell adhesion and spreading, whereas the antibody to integrin alpha2, alpha3, alpha5, beta2, alpha5beta1, or alphaVbeta5 had little effect on cell adhesion or spreading. The antibody to integrin alpha1, but not to other subunits, coprecipitated 125I-CMP that was added to MRC5 cell lysates, indicating the association of CMP with the integrin alpha1 subunit. Unlabeled CMP competed for the binding to integrin alpha1 with 125I-CMP. These findings suggest that CMP is a potent adhesion factor for chondrocytes, particularly in the presence of type II collagen, and that integrin alpha1beta1 is involved in CMP-mediated cell adhesion and spreading. Since CMP is expressed almost exclusively in cartilage, this adhesion factor, unlike fibronectin or laminin, may play a special role in the development and remodeling of cartilage.

Animals↗

PubMed1999

A testis-specific androgen receptor coregulator that belongs to a novel family of nuclear proteins.

We have characterized a novel partner for androgen receptor (AR), termed ARIP3, that interacts with the DNA-binding domain/zinc finger region of AR and is predominantly expressed in the testis. Rat ARIP3 is a nuclear protein comprising 572 amino acids. It modulates AR-dependent but not basal transcription, suggesting that ARIP3 acts as an AR transcriptional coregulator. Except for the C-terminal AR-interacting domain, ARIP3 contains distinct regions that are also present in two recently described proteins, a protein inhibitor of activated Stat3 and an RNA helicase II-interacting protein (Gu/RH-II binding protein). Conserved structural features of these proteins indicate the existence of a gene family involved in the regulation of various transcription factors. Collectively, ARIP3 belongs to a novel nuclear protein family and is perhaps the first tissue-specific coregulator of androgen receptor.

Amino Acid Sequence↗

PubMed1999

Regulation of endothelin-1 synthesis by endothelin-converting enzyme-1 during wound healing.

Endothelin-1 (ET-1) is involved in the pathogenesis of a number of diseases, including wound healing. In cirrhosis, the wounding response of the liver, circulating ET-1 levels are elevated; moreover, ET-1 has potent effects on hepatic stellate cells, the key effectors of cirrhosis. In this study, we have examined the regulatory role of ECE-1, a critical enzyme involved in ET-1 synthesis, in the two major cellular sources of hepatic ET-1. ET-1 release from normal hepatic endothelial cells was 25-fold higher than that from normal stellate cells. However, after liver injury, ET-1 release was increased in stellate cells but markedly decreased in endothelial cells. The two major isoforms of ECE-1, ECE-1alpha/1beta, made up 80% and 20%, respectively, of total ECE-1 in both stellate and endothelial cells. Following liver injury, ECE-1alpha mRNA was decreased by 44.2% in stellate cells, and by 16.1% in endothelial cells. ECE-1beta mRNA expression remained unchanged after injury. In contrast to ECE-1 mRNA, ECE-1 protein expression was increased by 43.9% in stellate cells but decreased in endothelial cells, while relative ECE-1 enzymatic activity was unchanged. In mRNA stability experiments, the half-life of ECE-1alpha mRNA in normal stellate cells was 13 h compared with 38 h in cells from injured livers. Thus, during hepatic wound healing, differential regulation of ECE-1 mRNA and protein appears to be critical in controlling ET-1 production.

Animals↗

PubMed1999

Allele frequencies of eight STRs in Japanese and Chinese.

Allele frequencies for the eight STR loci Hum-CSF1P0, F13A01, F13B, FES/FPS, LPL, TH01, TPOX and VWA were investigated in Japanese and Chinese populations. No significant deviations from Hardy-Weinberg equilibrium could be found for all loci. In the Japanese population VWA, CSF1PO, TH01, FES/FPS and TPOX were found to be useful for forensic applications and in the Chinese population, VWA, CSF1PO, TH01 and TPOX were found to be useful. Allele distributions were similar between both populations except for FES/FPS.

Alleles↗

PubMed1999

Ggamma13 colocalizes with gustducin in taste receptor cells and mediates IP3 responses to bitter denatonium.

Gustducin is a transducin-like G protein selectively expressed in taste receptor cells. The alpha subunit of gustducin (alpha-gustducin) is critical for transduction of responses to bitter or sweet compounds. We identified a G-protein gamma subunit (Ggamma13) that colocalized with alpha-gustducin in taste receptor cells. Of 19 alpha-gustducin/Ggamma13-positive taste receptor cells profiled, all expressed the G protein beta3 subunit (Gbeta3); approximately 80% also expressed Gbeta1. Gustducin heterotrimers (alpha-gustducin/Gbeta1/Ggamma13) were activated by taste cell membranes plus bitter denatonium. Antibodies against Ggamma13 blocked the denatonium-induced increase of inositol trisphosphate (IP3) in taste tissue. We conclude that gustducin heterotrimers transduce responses to bitter and sweet compounds via alpha-gustducin's regulation of phosphodiesterase (PDE) and Gbetagamma's activation of phospholipase C (PLC).

Amino Acid Sequence↗

PubMed1999

Recombinant fusion protein and DNA vaccines against foot and mouth disease virus infection in guinea pig and swine.

In this study, we provide evidence that a recombinant fusion protein containing beta-galactosidase and a tandem repeat peptide of immunogenic dominant epitope of foot-and-mouth disease virus (FMDV) VP1 protein elicits high levels of neutralizing antibody and protects both guinea pigs and swine against infection. Vaccination with this fusion protein induced a FMDV-specific proliferative T-cell response and a neutralizing antibody response. The immunized guinea pigs and swine were protected against FMD type O virus infection. Two DNA plasmids expressing genes of foot-and-mouth disease were constructed. Both plasmids pBO1 and pCO1 contain a signal sequence of the swine immunoglobulin G (IgG) gene and fusion protein gene of pXZ84. The signal sequence and fusion protein gene were under the control of a metallothionein promoter in the case of the pBO1 plasmid and under the control of a cytomegalovirus immediate early promoter in the case of pCO1 plasmid. When pBO1 and pCO1 were inoculated intramuscularly into guinea pigs, both plasmids elicited a neutralizing antibody response and spleen cell proliferation increased following stimulation with FMDV antigen, but animals were not protected from viral challenge.

Animals↗