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Biomedical subjects

Y H Yang

Publications and source records attributed to Y H Yang.

At least 109 records · Page 6Linked to original sources
PubMed1997

Exacerbation of adjuvant arthritis by adrenalectomy is associated with reduced leukocyte lipocortin 1.

OBJECTIVE: Lipocortin 1 is a mediator of the antiinflammatory actions of therapeutic glucocorticoids. ENdogenous glucocorticoids modulate inflammatory arthritides including rheumatoid and adjuvant arthritis (AA), but the role of lipocortin 1 in this phenomenon is not known. We studied the effects of endogenous glucocorticoids on adjuvant arthritis and leukocyte lipocortin 1 content. METHODS: Adrenalectomy of sham adrenalectomy was performed 2 days before adjuvant injection in 170 g inbred Sprague-Dawley rats. Peripheral blood was obtained and disease severity assessed by delta paw volume and clinical score 14 days later. Leukocyte subset lipocortin 1 content was determined by double labeling permeabilization flow cytometry using specific monoclonal antibodies. RESULTS: Lipocortin 1 fluorescence was readily detected in control rat peripheral blood cells labeled with OX-1 (pan-leukocyte), OX-19 (CD5), W3/25 (CD4), and OX-8 (CD8). Lipocortin 1 fluorescence was significantly greater in polymorphonuclear leukocytes (PMN) (RP3; p < 0.01). Induction of AA was accompanied by significant increases in lipocortin 1 (p < 0.001) in all subsets. Sham adrenalectomy induced no significant change in AA rat leukocyte lipocortin 1. Adrenalectomy induced significant exacerbation of AA disease severity compared to sham operation (delta paw volume 1.43 +/- 0.1 vs 1.13 +/- 0 ml; p < 0.05). Adrenalectomy was also associated with significant reduction in lipocortin 1 content in all leukocyte subsets except PMN. Leukocyte lipocortin 1 content exhibited significant negative correlation with clinical disease severity (R2 = -0.55; p < 0.05). CONCLUSION: Endogenous glucocorticoids modulate leukocyte expression of lipocortin 1 in inflammatory disease, and reduced lipocortin 1 may be involved in the exacerbation of AA by adrenalectomy.

Adrenalectomy↗
PubMed1996

Heterogeneity of the human Secretor alpha(1,2)fucosyltransferase gene among Lewis(a+b-) non-secretors.

The human Secretor alpha (1,2)fucosyltransferase gene determines the ABH secretor status and influences the Lewis phenotype of an individual. Two different se alleles with point mutations, C571 to T and G849 to A respectively, in the coding region were identified in Le(a+b-) non-secretors from one of the Taiwanese indigenous groups. The base substitutions predict the alteration of Arg191 and Trp283 to stop codons respectively, resulting in deletion of the Secretor enzyme's C-terminal segment. Both alleles of the Secretor locus in all Le(a+b-) non-secretors, but not in Le(a+b-) secretors, were further demonstrated to be either one of these two se alleles with nonsense mutations. These results suggest two new molecular bases for the null se allele responsible for the formation of the non-secretor phenotype.

ABO Blood-Group System↗
PubMed1996

Identification and characterization of the acoD gene encoding a dihydrolipoamide dehydrogenase of the Klebsiella pneumoniae acetoin dehydrogenase system.

The acoD gene, which encodes a dihydrolipoamide dehydrogenase component of the acetoin dehydrogenase enzyme system of Klebsiella pneumoniae was isolated and the nucleotide sequence determined. The gene is capable of encoding a protein of 465 amino acid residues with conserved binding domains for NAD and FAD, and two redox-active cysteine residues. The acoD gene product exhibited a Michaelis constant of 170 microM for NAD, while NADP can not be used as a substrate. The purified enzyme appeared to be a dimer of the acoD gene product. It did not associate tightly with the E1 and E2 components of either acetoin dehydrogenase or 2-oxoglutarate dehydrogenase to form an active multi-enzyme complex.

Acetoin Dehydrogenase↗
PubMed1996

Chorionic villus sampling: clinical experience of the initial 750 cases.

OBJECTIVE: To assess the factors that might influence the success rate, safety and reliability of chorionic villus sampling (CVS) and to evaluate the relationship between CVS and other congenital anomalies. DESIGN: Analysis of the outcome of 750 cases of CVS (730 cases with transcervical and 20 cases with transabdominal). SETTING: The outpatient prenatal genetic clinic of a university tertiary care center. SUBJECT: Seven hundred and fifty pregnant women that underwent CVS for prenatal genetic diagnosis from 7 to 12 weeks of gestation. RESULTS: Advanced maternal age was the most common indication for CVS (32.8%). The overall sampling success rate was 98.0% (735/750), representing 93.9% at 7 to 8 weeks, 98.1% at 9 to 10 weeks, and 98.3% at 11 to 12 weeks of gestation. The majority of cases (93.1%) required one or two aspirations. Cytogenetic analysis routinely included direct overnight and long-term culture methods which revealed 16 abnormalities (2.2%). Of 735 cases in which CVS was successful, 700 advanced to normal offspring, 17 had therapeutic termination, and 18 resulted in spontaneous abortions; there was an overall fetal loss rate of 2.4% (18/750). CONCLUSION: CVS in early pregnancy is a relatively safe and reliable method of prenatal genetic diagnosis capable of replacing genetic amniocentesis. However, it must be done by experienced personnel. No congenital anomalies were found to be related to CVS in this series.

Adult↗
PubMed1996

[Vaginal colonization of group B Streptococcus: a study in 267 cases of factory women].

An epidemiologic study on vaginal colonization of group B streptococcus (GBS) from non-pregnancy women was carried out. Two hundred sixty seven female workers were studied. The carrier rate of GBS in vaginal specimens was 10.86%. Women aged 45 years old and above had more cases with genital tract GBS colonization. Women with vaginal colonization had more history of miscarriage and using IUD. We did not find the positive correlations between vaginal colonization and oral contraceptive, ovarian cyst, hysteromyoma in our study group. Women with gynecologic inflammation had more cases with vaginal GBS colonization. There is a significant increase for women with vaginitis and cervicitis. Serotyping study showed that types III and II were the most frequent GBS types isolated from the carriers. Antibiotic sensitivity test showed that more than half GBS strains were resistant to oxcillin and amikacin.

Adult↗
PubMed1995

Correlation of a missense mutation in the human Secretor alpha 1,2-fucosyltransferase gene with the Lewis(a+b+) phenotype: a potential molecular basis for the weak Secretor allele (Sew).

A missense mutation (A385 to T), predicting an Ile129 to Phe substitution, in the human Secretor alpha 1,2-fucosyltransferase gene was present in double dose in Lewis(a+b+) individuals, but not in Lewis(a-b+) individuals. Co-segregation of the Lewis(a+b+) phenotype with homozygosity for the mutation was also verified. These results yield a potential molecular basis for the weak Secretor allele (Sew) accounting for the Lewis(a+b+) phenotype.

Alleles↗
PubMed1995

Rapid chromosome analysis and prenatal diagnosis using fluid from the cystic hygroma, hydrothorax and isolated ascites: new source for chromosome analysis.

OBJECTIVE: To determine whether abnormally collected fetal body fluid could be used as alternative cell sources for cytogenetic assessment. METHOD: Using modified lymphocyte culture, the abnormal fetal body fluids obtained from the five fetal anomaly cases (3 cystic hygromas, 1 hydrothorax, and 1 isolated ascites) were analyzed in order to determine their karyotypes. RESULTS: Two cases showed 45, X and 46, XX/45, X and the other three showed a normal karyotype. CONCLUSION: The cytogenetic analysis from body fluid aspiration yields a rapid and accurate result within 96 hours. This method could be helpful when cordocentesis or placental biopsy is not feasible or when time requirement for amniotic fluid cell culture is burdensome to patient management.

Adult↗
PubMed1995

CDEBP, a site-specific DNA-binding protein of the 'APP-like' family, is required during the early development of the mouse.

A murine protein, termed CDEBP, was previously shown to bind the double-stranded DNA motif GTCACATG, identical to the yeast centromeric element CDEI. The cDNA sequence showed three domains with extensive similarities to the amyloid beta precursor protein (APP). The protein is homologous over its entire length to the human protein designated APPH. In situ immunofluorescence assays using antibodies raised against distinct parts of CDEBP detected discrete sites of accumulation inside the interphase nucleus, and the bulk of the protein was not associated with mitotic chromosomes. One of the complexes with double-stranded CDEI oligonucleotides detected by gel shift assay was not present when the protein had been selectively removed from nuclear extracts by immunoprecipitation. We reported previously that microinjection into one-cell mouse embryos of DNA fragments including the CDEI sequence results in an early arrest of development with abnormal nuclei containing variable amounts of DNA. The same characteristic figures were observed when embryos were treated with antisense oligonucleotides complementary to parts of the CDEBP coding region. Complexes between the CDEBP protein and CDEI sites in the mouse genome thus appear to play a critical role in the replication/segregation of the embryonic genome.

3T3 Cells↗
PubMed1995

Prenatal fetal sex determination from maternal peripheral blood using polymerase chain reaction.

We have investigated the use of a nested polymerase chain reaction(PCR) assay with Y-specific sequence from the DYS 14 locus on the short arm of Y-chromosome for prenatal sex determination in the peripheral blood of 22 pregnant women who participated in the antenatal genetic diagnosis program. The sensitivity and specificity of the nested PCR using DYS 14 locus primers(Y1.5,Y1.6, and Y1.7,Y1.8) were 76.4% and 55.5%, respectively. In terms of gestational age, positive predictive values of 66.6%, 66.6%, and 80% were obtained for the first, second, and third trimester respectively. The corresponding negative predictive values were 50%, 50%, and 100% respectively. Male specific band was positive in three of the six cases of female bearing women and male specific band was negative in three of the seven cases of male bearing women during 9-16 gestational weeks showing low sensitivity. But all cases except one show the male specific band during the male fetus and all female fetuses did not show the male specific 198 base pair band during 18 approximately 40 gestational weeks. This study suggests that prenatal sex determination by PCR employing maternal peripheral blood was usually possible in late pregnancy but less reliable in early pregnancy. It seems that if we used a method separating fetal cells from maternal blood and then run PCR on these cells with DYS 14 locus primers we could make a fairly accurate fetal sex determination.

Base Sequence↗
PubMed1995

Cytogenetic study employing chorionic villi in ectopic pregnancy.

Maternal factors such as salpingitis and peritubal adhesion are known to be associated with ectopic pregnancy; however, a few studies have considered the chromosomal complements of ectopic conceptuses. We studied 16 ectopic conceptuses obtained by surgical resection. The karyotyping of chorionic villi was performed using direct and culture technique. Among 16 studied cases, 14 cases showed normal karyotype (nine with 46, XY; five with 46, XX). One case showed trisomy 16(47, XY, + 16) and another showed variation from normal chromosomal complement (46, XY, 14s+), resulting in 6.3% incidence of the structural abnormalities of the chromosome. On the basis of our study, we determined the possibility of chorionic villi karyotyping in ectopic pregnancy. This ectopic conceptuses are no more likely to show chromosomal abnormalities than in utero conceptuses of comparable gestational age. Therefore, maternal factors such as salpingitis and peritubal adhesion are the most likely explanations for ectopic pregnancy.

Adult↗
PubMed1995

[Perinatal colonization of group B streptococcus: a study in 600 cases in Beijing Tiantan Hospital].

An epidemiologic study of perinatal colonization of group B streptococcus (GBS) was carried out. Six hundred mother-infant pairs were studied at Beijing Tiantan Hospital. Maternal carriage rate of GBS was 8% with a neonatal colonization rate of 6.7%. Overall perinatal carriage rate was 13%. Women with perinatal colonization showed prone to have more premature and low birth weight babies. We did not find that perinatal colonization was associated with prolonged rupture of membranes and IUGR in our study group. Serotypical study showed that most frequent GBS type isolated from the carriers was III, followed by I a. Antibiotic sensitivity study showed that more than half of the GBS strains were resistant to the antibiotics a severe problem which might have caused by abuse in this country.

Female↗
PubMed1994

Flow cytometric detection of anti-neutrophil cytoplasmic autoantibodies.

An intracytoplasmic immunofluorescence staining technique which allows the detection and quantification of anti-neutrophil cytoplasmic autoantibodies (ANCA) by flow cytometry is described. A polymorph neutrophil population from human peripheral blood was used in this study as indicator cells. These were fixed and permeabilized by paraformaldehyde, Tween 20 and saponin, to allow ANCA in the patients sera to reach their intracellular antigen targets. The numbers of indicator cells remained unaltered by the permeabilization protocol and no cell aggregation or loss of intracellular antigenicity was observed. An excellent agreement (91% (207/228)) between ANCA detection by immunofluorescence microscopy (IF) and flow cytometry was noted. Compared with IF assay, the flow cytometric method has a sensitivity of 93% (42/45) and a specificity of 90% (165/183). Although not able to discriminate between P-ANCA or C-ANCA, this flow cytometric method has the advantage of providing an objective, reproducible and quantitative measure of ANCA, which makes it an ideal technique for screening of patients sera for ANCA reactivities.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

Cloning and sequencing of the major rainbow trout constitutive cytochrome P450 (CYP2K1): identification of a new cytochrome P450 gene subfamily and its expression in mature rainbow trout liver and trunk kidney.

We have cloned and sequenced a full-length cDNA encoding the major constitutive rainbow trout liver cytochrome P450 that we had earlier designated as cytochrome P450 LMC2 (Arch. Biochem. Biophys. 268, 227, 1989). The 1859-bp cDNA was isolated from a male rainbow trout liver cDNA library and contained an open reading frame encoding for a protein of 504 amino acids and having a calculated molecular weight of 56,795. From nucleotide and amino acid sequence comparisons, the trout P450 LMC2 has been assigned to a new cytochrome P450 gene subfamily designated P4502K1 or CYP2K1. Marked differences in the sex- and tissue-specific expression of this gene were found at both the transcriptional and translational level in sexually mature rainbow trout liver and trunk kidney. Transcriptional expression investigated by Northern analysis of total RNA using a 440-bp 3'-terminal cDNA probe (2K1,7c) showed sexual and organ differences. Mature male trunk kidney expressed 2K1,7c-hybridizable mRNA to a substantially greater extent than did female trunk kidney, with multiple mRNA bands appearing in approximately the 2.8- and 1.9-kb region. While the livers of some males displayed separate 2.8-kb hybridizable bands, such bands were generally undetectable in female liver samples. By contrast, 1.9-kb mRNA bands were found at generally similar concentrations in the livers of both sexes. Taking into consideration the individual biological variabilities, it was apparent that mature male trout expressed the 2.8-kb mRNA much more strongly in trunk kidney than in liver. Translational expression, analyzed by Western blotting of microsomes separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and probed with rabbit polyclonal antibody and two different monoclonal antibodies prepared against P450 LMC2, demonstrated corresponding sex- and organ-related differences in P450 protein expression. Southern analysis of sexually mature male trout genomic DNA suggested that CYP2K1 is not a single copy gene, thus providing additional evidence for the complexity of the CYP2K1 system in rainbow trout.

Aging↗
PubMed1994

Inactivation and elimination of viruses during preparation of human intravenous immunoglobulin.

We report here the results of our evaluation of virus inactivation during the manufacturing steps of two intravenous immunoglobulin (IGIV) preparations. Virus inactivation and/or removal by processing steps, such as ethanol fractionation and polyethylene glycol precipitation, and deliberate virucidal steps, such as solvent/detergent treatment and pasteurization, were tested on a variety of human pathogenic and experimental model viruses, including human immunodeficiency, Hepatitis C, Mumps, Vaccinia, Chikungunya, Vesicular Stomatitis, Sindbis, and ECHO viruses. All viruses were successfully inactivated and/or eliminated by the processing steps studied. In some cases, however, multiple steps were required. We conclude that the incorporation of steps deliberately designed to inactivate or remove viruses during the production of IGIV provides an extra measure of viral safety.

Alphavirus↗
PubMed1994

Antibody Fc functional activity of intravenous immunoglobulin preparations treated with solvent-detergent for virus inactivation.

We report here results of in vitro comparisons of the Fc functional activity of a second-generation intravenous immunoglobulin (IGIV) preparation (Venoglobulin-I) and a third-generation IGIV product that includes a deliberate virus-inactivation step (Venoglobulin-S). Both formulations showed equivalent Fc-mediated function against viral antigens (rubella, influenza A, and influenza B) by single-radial hemolysis test, and against group B Streptococcus, Staphylococcus aureus and Escherichia coli by opsonophagocytosis assay. In addition, we showed by three different immunochemical reactions and by HPLC analysis that both preparations consisted of mostly monomeric IgG and contained very low levels of complement-fixing IgG aggregates. However, IgG aggregation induced by heating at 63 degrees C markedly enhanced fixation of Clq and C3 and binding to Raji cells, indicating that the IgG molecules retained their complement-fixing capacity. Thus, the incorporation of a virus inactivation step in the manufacture of our third-generation IGIV did not alter the Fc functional activities of the IgG, as measured by these in vitro assay systems.

Antibodies, Bacterial↗
PubMed1994

[The hemodynamic and oxygen dynamic effects of mechanical ventilation in chronic cor pulmonale].

Observation by using Swan-Ganz catheter on hemodynamic and oxygen dynamic changes before and after assisted volume controlled mechanical ventilation (MV) was carried out in 11 cases of chronic cor pulmonale complicated with pulmonary encephalopathy. Pulmonary vascular resistance and pulmonary artery pressure were significantly decreased by the relief of hypoxia pulmonary vasoconstriction after MV. Because of the relax of sympathetic tension, the heart rate, arterial blood pressure, pulmonary capillary wedge pressure and central venous pressure reduced simultaneously. Left and right ventricular stroke work decreased after MV, without significant change in cardiac output. Venous admixture (Qs/Qt) was markedly reduced by MV and oxygen supply-demand ratio raised. It is thus shown that marked improvement of hemodynamic and oxygen dynamic status can be induced by mechanical ventilation at an opportune moment.

Aged↗