Biomedical subjects
Publications and source records attributed to M Wang.
In vitro, inhibition of 5 compounds from Bidens bipinnata on two leukemia cells HL-60 and V397 is presented by determination of MTT living cell in this paper. The result show that the compounds have the action of inhibition, IC50 on V937 < or = 60 micrograms/ml.
Ampelopsis cantoniensis (Hook. et Arn.) Planch. is a Chinese herbal medicine rich in flavonoids. A method to determine flavonoids in the herbal was studied. After the herbal was extracted in hot water, Ampelopsin and myricetin in the extract were separated by polyamide column with eluent of ethanol-water and measured by spectrophotometry. As results, 100 g of the dry herbal contains 25.2 g of ampelopsin (RSD = 1.7%, recovery = 97.0%) and 1.77 g of myricetin (RSD = 3.3%, recovery = 103%).
An influenza virus was isolated in May, 1991 from a child with acute respiratory disease. The identification results with serologic method have revealed that the isolate was A/PR/8/34 (H1N1)-like virus. The analyses of nucleotide sequences in HA1 domain showed that there were 12 different positions on nucleotide sequences between the isolate and the A/PR/8/34 (H1N1) virus. These differences induced substitutions of 4 amino acids in HA1 protein molecule of isolate as compared with that of A/PR/8/34 (H1N1) virus. The oligonucleotide analyses of viral genome revealed that there were 11 different points between isolate and A/PR/8/34 (H1N1) virus, e. g. 2 deleted and 9 inserted in genome of isolate as compared with A/PR/8/34 (H1N1) strain. Therefore, the isolate possibly derived from A/PR/8/34 (H1N1) virus by laboratory contamination could be ruled out. However, where did A/Guangdong/6/91 (H1N1) virus come from? This question will be settled by further study.
Three strains of influenza A virus were isolated from patients suffering from influenza like disease in Railway Hygiene and Anti-epidemic Station of Taiyuan in January 1996. The identification results by serological method indicated that the isolates were different from H1N2 subtype of influenza A virus isolated from men in 1989 and 1992 and that their HA antigenicity was similar to that of A/RP/8/34 (H1N1) virus, but distinguishable from that of influenza A (H1N1) virus circulating in mans recently. The comparison of migration patterns of the RNA among the isolates, the A/PR//34 (H1N1) and the A/Wuhan/359/95 (H3N2) viruses revealed that the migration patterns of RNA 1-4 segments of the isolates were similar to those of A/PR/8/34 (H1N1) virus, but those of RNA 5-6 segments were indistinguishable from those of A/Wuhan/359/95 (H3N2) strain. However, the migration patterns of RNA 7-8 segments of the isolates were not only different from those of A/PR/8/34 (H1N1) virus, but also distingrasgable from those of A/Wuhan/359/95 (H3N2) strain. Therefore, it could be considered that the isolates were a novel reassortant H1N2 influenza A virus.
Virus isolation was carried out from mosquitoes and ticks captured in nature from Hainan Island of China from 1983-1988. Twenty-eight non-dengue and non-Japanese encephalitis viral strains were isolated from different places, of which 27 strains were recovered from different species of mosquitoes and 1 strain from ticks. At the Division of Vector-Bore Viral Diseases, National Center for Infectious Diseases, Centers for Disease Control, USA, identification of virus family and virus genus on these 28 viral strains was conducted by the use of a complete set of internationally standardized antibodies against arboviruses and by means of indirect immunofluorescence. Results proved that all these 28 viral strains belonged to the Genus Alphavirus of the Family Togaviridae.
The brains of suckling mice and suspension of Vero-E6 cells inoculated with Chen's strain of hemorrhagic fever with renal syndrome virus (HFRSV) were obtained and prepared into high titre hemagglutinin (HAN). The crude HAN was purified by high pressure liquid chromatography. The molecular weight of the purified HAN is 56600 and has higher titre of hemagglutinin activity. It has been proved that the purified HAN has homogeneous molecular weight and buoyant density through SDS-PAGE and sucrose gradient ultracenrifugation. Nine monoclonal antibodies (McAb) from varions HFRS virus have been used for analyzing the epitope of purified HAN by ELISA. It was demonstrated that the purified HAN has epitopes of hemagglutinin and neutralizing antigens. The Balb/C mice could be induce specific antibody against HFRSV by immunization with purified HAN. The titre of neutralization was 40 and titre of hemagglutinin inhibition was 64. Some problems concerning the HAN of HFRS virus were discussed.
OBJECTIVE: To investigate the effect of histamine type II (H2) receptors on the inhibition of hematopoiesis by CD8+ cells from aplastic anemia (AA) patients. METHODS: The effects of CD8+ cells and/or cimetidine, alone or in combination, on normal human CFU-GM growth were studied by using CFU-GM assay. RESULTS: The CD8+ cells from the peripheral blood of AA patients significantly suppressed the growth of normal allogeneic CFU-GM. This inhibitory effect could be blocked by 0.5 x 10(-5) mol/L or 1.0 x 10(-5) mol/L cimetidine. 1.0 x 10(-5) mol/L cimetidine alone slightly inhibited the growth of normal CFU-GM, but 0.5 x 10(-5) mol/L cimetidine did not. CONCLUSION: H2 receptor antagonist cimetidine abolished the suppressive effect of AA patients CDB+ cells on the growth of normal CFU-GM.
In the past few years, much attention has been focused on the studies of the chirality recognition properties of chiral crown ether hosts containing the binaphthyl unit. The application of chiral 1,1'-binaphthyl-2,2'-diol (1) in asymmetric synthesis has been proved fruitful. Consequently, the preparation of optically active binaphthol and the determination of its enantiomeric purity is of current interest. In this paper, an efficient HPLC method for determination of enantiomeric purity of 1,1'-binaphthyl-2,2'-diol (1) through formation of a couple of diastereomers, (R)-1,1'-binaphthyl-2,2'-diyl-N-(S)-(alpha-methylbenzyl) phosphoramidate (R,S)-2 and (S)-1,1'-binaphthyl-2,2'-diyl-N-(S)-(alpha-methylbenzyl)phosphoramidate (S,S)-2, is described by using Micropak Si-5 column, petroleum and ethanol (7:3, V/V) as eluate and UV detector (lambda = 300nm). The method is convenient, rapid and accurate. The accuracy was between 98.6%-101.6%, and the average deviation was 1.01%.
Ibuprofen is an excellent anti inflammatory and analgesic drug. It possesses a chiral carbon atom in its molecule. For the two enantiomers, only the S(+)-isomer is highly active, whereas the R(-)-isomer has very low activity. S-isomer can be isolated by resolution from its racemoid and the R-isomer can be racemized under basic condition. Consequently it is highly important to determine its enantiomeric purity. In this paper, an efficient HPLC method for determination of enantiomeric purity for ibuprofen (1) through the formation of a couple of diastereomers, N-(S)-(alpha-methylbenzyl)-alpha-methyl-4-(alpha-methylpropyl)benzeneacetic amide [R,S-(2)], and (S)-(alpha-methylbenzyl)-alpha-methyl-4-(2-methyl-propyl)benzeneacetic amide [S,S-(2)], was developed using Micropak Si-5 column, petroleum ether and ethyl ether (1:1 volume) as eluate and UV detector (lambda = 300 nm). The method is convenient, rapid and accurate. The accuracy was between 99.71%-100.25%, and the average deviation was 0.064%.
To investigate the prevalence of human polyomaviruses in Taiwan, urine samples from immunocompetent (healthy), transient immunocompromised (pregnant), and prolonged immunosuppressed (autoimmune disease) individuals were collected throughout the island. The viral DNA in the urine was detected by the polymerase chain reaction (PCR) and Southern blot. The viral genotypes were determined by DNA sequencing within the regulatory region. The overall results, including cases reported previously, show that 13.3% (10/75) of immunocompetent individuals, 26.0% (20/77) of pregnant women, and 37.5% (18/48) of autoimmune disease patients are JCV positive. All of the immunocompetent individuals are BKV negative, but 3.9% (3/77) of the pregnant women and 6.2% (3/48) of autoimmune disease patients are BKV positive. Twenty-four percent (48/200) of the examined urine samples were JCV positive, but only 3% (6/200) were BKV positive. JCV positive individuals were mainly infected with CY (42%) and TW-1 (52%) subtypes. These results suggest that the incidence of urinary excretion of human polyomaviruses in immunosuppressed individuals is higher than that of immunocompetent individuals. The prevalence of JCV appears to be higher than that of BKV in Taiwan. In addition, CY and TW-1 are the predominant subtypes of JCV prevalent in the Taiwanese population.
Four different-strains of human polyomavirus JC virus (JCV), CY, Taiwan-1, Taiwan-2, and Taiwan-3, have been found in pregnant women and autoimmune disease patients in Taiwan. In this study, we report the cloning and sequencing of the Taiwan-3 JCV, virus isolated from the urine of an immunosuppressed patient with rheumatoid arthritis. The viral genome was amplified by polymerase chain reaction and then cloned into a prokaryotic replicative plasmid, pGEM-7Zf(-). The genomic DNA was sequenced and found to comprise 5,111 base pairs. The enhancer-promoter region of the viral genome lacks a copy of pentanucleotide-A (GGGAA) and pentanucleotide-B (AAAGC) compared to the CY archetypal JCV. There are 108 nucleotides altered in the total genome, excluding the variable part of the enhancer-promoter region, between Mad-1 (the prototype JC virus) and Taiwan-3. The enhancer-promoter region has approximately 25% of the altered nucleotides, resulting in amino acid changes in the open reading frames for I.T. capsid proteins (VP1, VP2, and VP3), and the agno protein. The cloned Taiwan-3, genome will provide an source for physiologic and pathologic investigation of the JCV virus in the future.
Explore the source record for details and available documents.
The molecular mechanism by which IL-10 inhibits metastases was examined using a SCID mouse model. Human PC-3 ML subclones normally metastasize to the lumbar vertebrae (approximately 70% mice injected, n = 14/20) following intravenous injection in severe combined immunodeficient (SCID) mice. IL-10 treatment of the PC-3 ML cells (15 ng/ml for 36 h) and the SCID mice (0.03 mg/kg/day for 30 days) reduced the number of metastases to 5% of the mice (n = 1/20). More importantly, following discontinuation of IL-10 treatment on day 30, the mice remained tumor-free and mouse survival rates increased dramatically (from < 30% in untreated mice) to about 85% in IL-10-treated mice. IL-10 did not appear to alter the growth rates or colony-forming ability of the PC-3 ML cells in vitro. Likewise, the growth of subcutaneous tumors and established bone marrow metastases was not inhibited by IL-10 treatment of the SCID mice. However IL-10 may inhibit the production of matrix metalloproteases (MMP) and prevent the establishment of metastasis. We therefore examined the influence of IL-10 on PC-3 ML production of MMP-2/MMP-9 and the tissue inhibitors of metalloproteinases (TIMP-1/2). Enzyme-linked immunosandwich assays (ELISAs) revealed that IL-10 (15 ng/ml for 36 h) treatment of the PC-3 ML cells down-regulated MMP-2 and MMP-9 while up-regulating TIMP-1 (not TIMP-2) expression. Likewise, IL-10-treated mice exhibited similar changes in TIMP-1 and MMP-2/MMP-9 expression. The IL-10 effects were blocked by IL-10 receptor antibodies. In comparison to IL-10, IL-4 failed to influence metastasis or the expression of TIMP-1, TIMP-2, MMP-2 and MMP-9 by PC-3 ML cells. We suggest that IL-10-regulated increases in the molar ratio of TIMP-1/MMP-9 and TIMP-2/MMP-2 might inhibit processes critical to the establishment of bone marrow metastasis.
Explore the source record for details and available documents.
A new microcomputerized Fetal Electrocardiograph (FECG) is presented in this paper. A two-grade configuration (front-end & back-end) is designed for the instrument. The front-end processor is based on a Digital Signal Processor (DSP) TMS32010 and the Adaptive Noise Cancelling (ANC) algorithm to extract FECG with non-invasive method. The processed results are sent to the back-end personal computer for real time display, analysis and record. Clinical tests show the instrument is designed smartly and operated easily, and can be applied widely to many medical situations.
OBJECTIVE: To explore whether myocardial mitogen-activated protein kinase (MAPK) play an important role in hypertensive cardiac remodeling. METHODS: We compared myocardial MAPK activity by phosphocellular method and its localization and distribution by immunohistology in hypertrophic myocardium in SHRsp at age of 34 weeks (34 w group) and 54 weeks (54 w group) with age matched WKY served as control. RESULTS: SHRsp was compared with WKY. The heart weight to body weight ratio was significantly increased in both groups. Myocardial MAPK activity increased 1.81 fold in the 34 w group and 1.46 fold in the 54 w group. MAPK expressed abundantly in hypertrophic myocardium, mainly localized in interstitial cells. CONCLUSION: MAPK might be a major pathway of transducing hypertrophic signals.
The recombinant wild-type p53 adenovirus has been proven effective against the growth of human head and neck squamous cell cancer (SCCHN) cell lines iir vitro and in a nude mouse model. The addition of a FLAG peptide sequence was used in this study, along with the p53 adenovirus vector as a marker of the site of the gene therapy activity. It provides clear evidence of the exogenous gene product within the transduced carcinoma cells. No alterations in transcription or translation of the p53 gene product were noted with the addition of the FLAG sequence to the original p53 adenovirus vector. Immunohistochemical analysis displayed simultaneous expression of the p53 and FLAG proteins in the infected cells. The p53 protein remained localized to the nucleus, whereas the FLAG protein was additionally noted in the cytoplasm. In vitro growth suppression assays and in vivo microscopic residual tumor model experiments in nude mice showed a similar tumoricidal effect with the p53-FLAG adenovirus vector to that with the previously studied p53 adenovirus vector without the addition of the FLAG sequence. We conclude that the addition of the FLAG octapeptide sequence allows identification of those cells that have been affected by the molecular therapy independent of the endogenous gene expression of the cells. This novel molecular tracer may prove useful in characterizing infection efficiency and in gene therapy trials.
The tissue inhibitors of metalloproteinases (TIMPs) constitute a family of proteins, of which three members have so far been described. Using the expressed sequence tag sequencing approach, we have identified a novel TIMP-related cDNA fragment and subsequently cloned a fourth human TIMP (TIMP-4) from a human heart cDNA library. The open reading frame encodes a 224-amino acid precursor including a 29-residue secretion signal. The predicted structure of the new protein shares 37% sequence identity with TIMP-1 and 51% identity with TIMP-2 and -3. The protein has a predicted isoelectric point of 7.34. The open reading frame-directed expression of TIMP-4 protein in MDA-MB-435 human breast cancer cells showed metalloproteinase inhibitory activity on reverse zymography. By Northern analysis, only the adult heart showed abundant TIMP-4 transcripts with a 1. 4-kilobase predominant transcript band; very low levels of the transcripts were detected in the kidney, placenta, colon, and testes, and no transcripts were detected in the liver, brain, lung, thymus, and spleen. This unique expression pattern suggests that TIMP-4 may function in a tissue-specific fashion in extracellular matrix homeostasis.