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Biomedical subjects

R Wu

Publications and source records attributed to R Wu.

At least 217 records · Page 12Linked to original sources
PubMed1996

Induction of human cytotoxic T lymphocytes by oxidized low density lipoproteins.

Oxidized low density lipoproteins (oxLDL) stimulated human blood T cells to a specific cytotoxic response with autologous PHA activated blood mononuclear cells which had been pre-incubated with oxLDL. The cytotoxic reaction was exerted by CD8+ enriched cells but not by CD4+ enriched cells. Allogeneic target cells from HLA mismatched donors were not damaged and the reaction was consistently inhibited by monoclonal antibody against HLA class I. Antigen-specific cytotoxic T cells might contribute to lysis of cells in the atherosclerotic plaque that have taken up oxLDL and thus participate in the inflammatory process associated with atherosclerosis.

Cytotoxicity Tests, Immunologic↗
PubMed1996

De novo 46,XX, dir dup (11)(q133.3-->q14.2) in a patient with mental retardation, congenital cardiopathy and thrombopenia.

A 31-year-old female is reported with mild to moderate mental retardation, facial dysmorphy, congenital cardiopathy, and mild thrombocytopenia as the most important clinical findings. Chromosome analysis in lymphocytes showed a de novo dir dup (11)(q13.3-->14.2), by both G-banding and FISH techniques. Previously reported constitutional duplications of 11q are mostly the result of unbalanced translocations involving chromosome 11q, and are associated with a partial monosomy or trisomy of the translocation partner chromosome. In case of an unbalanced translocation it is not clear which clinical findings result from the chromosome 11 duplication and which result from the abnormality on the translocation partner chromosome. This is the first report on a constitutional duplication of chromosome region 11q13.3-->14.2 without involvement of other chromosomes.

Adult↗
PubMed1996

Isolation and characterization of nucleolin gene as one of the vitamin A-responsive genes in airway epithelium by a palindromic primer-based mRNA differential display method.

A palindromic primer-based mRNA differential display method has been used to isolate various vitamin A-responsive genes from primary cultures of monkey tracheobronchial epithelial cells. This method, as compared with the original mRNA differential display (mDD) method described by Liang and Pardee, used only one arbitrarily designed primer instead of two in the polymerase chain reaction. The single-primer mDD method has several advantages over the two-primer mDD system, especially in the reamplification and the selection of 5'-end cDNA clone. To verify the usefulness of this approach, one of these differential display bands, M34, was initially chosen for further amplification and cloning. The clone derived from the M34 band has a DNA sequence with > 90% homology to the human nucleolin gene. Furthermore, DNA sequencing confirms that both 5' and 3' ends of the insert of M34 contain the invertly repetitive nucleotide sequence that was used to direct this cloning. Nucleolin is a multifunctional phosphoprotein that plays an important role in ribosome biogenesis and mRNA stability. Northern blot analysis demonstrated that in addition to the elevation by vitamin A, the level of nucleolin message is significantly higher in fetal than in adult tracheobronchial epithelial cultures. Furthermore, in situ hybridization demonstrated that the amount of nucleolin message is significantly higher in both basal and ciliated cell types than in mucous and intermediary cell types. These results support the feasibility that the single-primer mDD technique can be used to isolate vitamin A-responsive genes with a palindromic nature.

Animals↗
PubMed1996

Open trial of fluvoxamine treatment for combat-related posttraumatic stress disorder.

A 10-week open-label trial of fluvoxamine was conducted for male Vietnam combat veterans with chronic PTSD. Subjects were excluded if they met full current criteria for panic disorder or agoraphobia, and lifetime criteria for psychosis, bipolar disorder, or organic mental syndrome. Repeated MANOVA was performed to determine change over time. Fluvoxamine was well tolerated; side effects were observed primarily early in treatment with headache, insomnia, sedation, and gastrointestinal distress being most frequent. Fluvoxamine was effective for treating the core intrusion, avoidance, and arousal symptoms of PTSD. Large treatment effects were seen by 4-6 weeks, and maintained at 10 weeks. The magnitude of change was greater than has been previously reported for antidepressant treatment of male Vietnam combat veterans with PTSD.

Ambulatory Care↗
PubMed1996

Conserved structure and adjacent location of the thrombin receptor and protease-activated receptor 2 genes define a protease-activated receptor gene cluster.

BACKGROUND: Thrombin is a serine protease that elicits a variety of cellular responses. Molecular cloning of a thrombin receptor revealed a G protein-coupled receptor that is activated by a novel proteolytic mechanism. Recently, a second protease-activated receptor was discovered and dubbed PAR2. PAR2 is highly related to the thrombin receptor by sequence and, like the thrombin receptor, is activated by cleavage of its amino terminal exodomain. Also like the thrombin receptor, PAR2 can be activated by the hexapeptide corresponding to its tethered ligand sequence independent of receptor cleavage. Thus, functionally, the thrombin receptor and PAR2 constitute a fledgling receptor family that shares a novel proteolytic activation mechanism. To further explore the relatedness of the two known protease-activated receptors and to examine the possibility that a protease-activated gene cluster might exist, we have compared the structure and chromosomal locations of the thrombin receptor and PAR2 genes. MATERIALS AND METHODS: The genomic structures of the two protease-activated receptor genes were determined by analysis of lambda phage, P1 bacteriophage, and bacterial artificial chromosome (BAC) genomic clones. Chromosomal location was determined with fluorescent in situ hybridization (FISH) on metaphase chromosomes, and the relative distance separating the two genes was evaluated both by means of two-color FISH and analysis of YACs and BACs containing both genes. RESULTS: Analysis of genomic clones revealed that the two protease-activated receptor genes share a two-exon genomic structure in which the first exon encodes 5'-untranslated sequence and signal peptide, and the second exon encodes the mature receptor protein and 3'-untranslated sequence. The two receptor genes also share a common locus with the two human genes located at 5q13 and the two mouse genes at 13D2, a syntenic region of the mouse genome. These techniques also suggest that the physical distance separating these two genes is less than 100 kb. CONCLUSIONS: The fact that the thrombin receptor and PAR2 genes share an identical structure and are located within approximately 100 kb of each other in the genome demonstrates that these genes arose from a gene duplication event. These results define a new protease-activated receptor gene cluster in which new family members may be found.

Amino Acid Sequence↗
PubMed1996

The replacement of water with deuterium oxide significantly improves the thermal stability of the oral poliovirus vaccine.

The poliomyelitis eradication programme relies largely on the massive administration of the oral poliovirus vaccine (OPV). The major difficulty in assuring good vaccine coverage, especially in hot climates, is the thermostability of the vaccine. Several attempts have been made to stabilize the OPV with limited benefits. In this report, we describe a heavy water based stabilization procedure, which has been shown to increase the thermostability of the vaccine, notably at temperatures which are commonly encountered during usual transportation in conditions of cold chain failure. Safety considerations regarding the human use of heavy water containing bioproducts are discussed.

Animals↗
PubMed1996

Physician's profile: fact or fiction?

Many physicians are bombarded with endless reams of data regarding their performance. In the current climate, the data frequently have a more implicit financial viewpoint. In an effort to economize healthcare delivery, several factors are under investigation. Manpower, resource use, and product delivery are just a few examples of factors investigated. Managerial trends have led to the development of numerical data on how specific physicians treat particular disease processes on a dollar-and-cents basis. Physicians need a better understanding of these managerial data. Integrated healthcare delivery systems are developing in most regions of the country. External customers are using physician profile data for exclusion or inclusion criteria in contract negotiation. The purpose of this study was to illustrate a situation in which physician profile data are a more appropriate reflection of the integrated healthcare system's profile.

Aged↗
PubMed1996

[Treating STZ-induced diabetic rats with agarose microcapsulated porcine islets].

OBJECTIVE: To study the function of microencapsulated porcine islets in vitro and in vivo. METHODS: Consecutive perfusion of collagenase via pancreatic ducts was used to isolate porcine islet of langerhans. The micro encapsulates were made by phase-separation method with Chinese-made agarose as immunoisolation membrane, 21 diabetic rats were used, 6 for comparing and 15 for transplantation. Six received intraperitoneally uncapsulated islets, 6 received intraperitoneally capsulated islets, and 3 injected uncapsulated islets under kidney capsules. RESULTS: The islets could secrete insulin consecutively for a month, and the cells in capsules survived very well without autolysis. In the early two days' culture, the islets had marked reactions to the stimulation from glucose in high concentration and theophylline. The amount of insulin released was 1.83 times and 2.28 times as much as that of glucose in low concentration respectively (P < 0.01). 2000-3000 microencapsulated islets per rat were transplanted intraperitoneally in six diabetic rats without the use of immunosuppressive drugs. On the 4th day, blood sugar dropped significantly until the 7th day, when it was in normal range. The concentration of blood sugar remained for 30 days. CONCLUSION: The agarose microcapsule processes a better function of immunoisolation, which may lay a foundation of treating IDDM with encapsulated porcine islets grafting.

Animals↗
PubMed1996

Different susceptibility of cervical keratinocytes containing human papillomavirus to cell-mediated cytotoxicity.

OBJECTIVE: To detect the factors responsible for the susceptibility of cervical keratinocytes infected with human papillomavirus (HPV) to non-specific lysis mediated by natural killer (NK) and lymphokine activated killer (LAK) cells. MATERIALS AND METHODS: Five cervical keratinocyte lines: CaSki, SiHa, HeLa (representing high grade squamous intraepithelial lesion (HSIL) ), W12 (representing low grade squamous intraepithelial lesion (LSIL) ) and NCx, (normal cervix) were used as target cells in the four-hour lactate dehydrogenase (LDH) release cytotoxicity assay. The effector cells were NK and LAK. The modulatory effects of interferon gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha) pretreatment of keratinocytes were investigated by adding IFN gamma or TNF alpha into the flasks of target cells 48 hours before the cytotoxicity assays. The blocking effects of anti-intercellular adhesion molecule-1 (ICAM-1) and anti-lymphocyte function-associated antigen-1 (LFA-1) monoclonal antibodies (Mabs) were also studied. RESULTS: All the 5 cervical keratinocytes were susceptible to LAK, but not to NK. The sensitivity varied among the cell lines. LAK had better killing effects on HSIL than on LSIL. Pretreatment of target cells with IFN gamma and TNF alpha increased the killing mediated by LAK, but had little effect on NK activity. Anti-ICAM-1 and anti-LFA-1 Mabs inhibited LAK-mediated cytotoxicity. CONCLUSIONS: All the HPV infected keratinocytes used in the experiments are NK-resistant and LAK-sensitive cells. IL-2, IFN gamma and TNF alpha play some critical roles in the regulation of the susceptibility of cervical keratinocytes, especially HSIL to LAK-mediated cytotoxicity in vitro.

Cells, Cultured↗
PubMed1996

[Changes in endothelin-1 and atrial natriuretic peptide in peritoneal fluid of pelvic venous congestion syndrome after tubal sterilization].

OBJECTIVE: To demonstrate the presence of endothelin-1 (ET-1), atrial natriuretic peptide (ANP) in peritoneal fluid of women and their effects on pathogenesis of pelvic venous congestion syndrome after sterilization (PVCSS). METHODS: This randomized controlled study determined the concentrations of ET-1 and ANP in both peritoneal fluid and plasma, counts of macrophage in peritoneal fluid and volumes of peritoneal fluid in 21 cases of PVCSS. 12 normal women after sterilization and 11 normal women as control in early follicular phase by radioimmunoassay. RESULTS: concentrations of ET-1, ratio of ET-1/ANP and counts of macrophage in peritoneal fluid with PVCSS were lower than those in control (P < 0.005, P < 0.001, P < 0.001) and all had significant negative correlation with scores quantifying the severity of PVCSS (P < 0.05), but volumes of peritoneal fluid in PVCSS were larger than that in control (P < 0.001); counts of macrophage in peritoneal fluid had significant positive correlation with the concentrations of ET-1 of peritoneal fluid in all the three groups (P < 0.05); plasma concentrations of ET-1 and ANP didn't show any significant differences among the three groups (P > 0.05). CONCLUSIONS: ET-1 was present in peritoneal fluid of normal women. Lower concentrations of ET-1 and (or) lower ratio of ET-1/ANP in peritoneal fluid contributed to the pathogenesis of PVCSS.

Adult↗
PubMed1996

[The experience in applying bovine pericardial patch in the correction of tetralogy of Fallot].

From January 1982 to December 1994, 432 patients with tetralogy of Fallot underwent the corrective operation. We extended the right ventricular outflow tract (RVOT) in 271 of the patients by using bovine pericardial patch treated by glutaraldehyde. The results were satisfactory. We emphasize that bovine pericardial patch is good material for extending RVOT, because it has many merits including high intensity, satisfied suture, no leakage, and abundant supply. Long-term follow up (maximum 12 years and 3 months) showed no ventricular aneurysm due to the degeneration of bovine pericardial patch.

Adolescent↗
PubMed1995

Photoaffinity labeling of a cell surface polyamine binding protein.

Intracellular polyamine pools are partially maintained by an active transport apparatus that is specific for and regulated by polyamines. Although mammalian transport activity has been characterized by kinetic studies, the actual protein itself has yet to be identified, purified, or cloned. As one approach to this problem, we attempted photoaffinity labeling of plasma membrane proteins using two specifically designed and synthesized polyamine conjugates as photoprobes. The first is a spermidine conjugate bearing the photoreactive moiety 4-azidosalicylic acid at the N4 position via an alkyl linkage, and the second is a norspermine conjugate with 4-azidosalicylic acid at the N4 position via an acyl linkage. Labeling of murine L1210 lymphocytic leukemia cells was carried out at 4 degrees C to promote selective alkylation of cell surface proteins. Separation of plasma membrane proteins from cells cross-linked with the N4-spermidine conjugate by SDS-polyacrylamide gel electrophoresis revealed two heavily labeled proteins at approximately 118 and approximately 50 kDa (designated p118 and p50, respectively). Band p118 was more well defined and much more intensely labeled. Analogous proteins were also observed in human U937 lymphoma cells. Specificity of labeling was strongly suggested by competition with polyamines and analogs during labeling and further indicated by the nearly identical labeling of the same protein by the N1-norspermine photoprobe but not by the unconjugated photoreagent. Neuraminidase pretreatment of L1210 cells increased mobility of the p118, suggesting that it was glycosylated and, thus, of plasma membrane origin. In transport-deficient L1210 cells, p118 and p50 were found to have a slightly higher molecular mass and were accompanied by a less distinct protein band (approximately 100 kDa). These findings indicate the presence of a polyamine binding protein at the surface of murine and human leukemia cells, which could be directly or indirectly related to the polyamine transport apparatus.

Affinity Labels↗
PubMed1995

DNA damage in human respiratory tract epithelial cells: damage by gas phase cigarette smoke apparently involves attack by reactive nitrogen species in addition to oxygen radicals.

Treatment of human respiratory tract tracheobronchial epithelial cells with gas-phase cigarette smoke led to dose-dependent DNA strand breakage that was highly correlated with multiple chemical modifications of all four DNA bases. The pattern of base damage suggests attack by hydroxyl radicals (OH.). However, by far the most important base damage in quantitative terms was formation of xanthine and hypoxanthine, presumably resulting from deamination of guanine and adenine respectively. Hence, DNA damage by cigarette smoke may involve reactive nitrogen species as well as reactive oxygen species.

Adenine↗
PubMed1995

Expression of human squamous cell differentiation marker, SPR1, in tracheobronchial epithelium depends on JUN and TRE motifs.

Tracheobronchial epithelial (TBE) cells that normally do not express the squamous cell differentiation marker gene, SPR1, can be induced to produce it by 12-O-tetradecanoylphorbol-13-acetate (TPA). The regulation of SPR1 gene expression by TPA occurs, in part, at the transcriptional level in primary human and monkey TBE cells. Using a transient transfection assay, we observed that TPA stimulates the activity of the reporter gene, chloramphenicol acetyltransferase, by 2-4-fold in transfected TBE cells. However, this chloramphenicol acetyltransferase activity is cell type-specific with significantly less activity in transformed epithelial cell lines and no activity in non-epithelial cell types. TPA-dependent stimulation can also be demonstrated by co-transfection with plasmid DNAs that overexpress the JUN family of proteins, especially c-JUN. Overexpression of c-JUN and TPA treatment synergistically stimulate the SPR1 promoter activity by more than 40-fold. Deletion analysis of the promoter region demonstrates that the DNA fragment of the first 98 base pairs of the 5'-flanking region contains the basal promoter activity, while the region between -162 and -96 contains the cis-enhancer elements for both the basal and TPA/c-JUN-stimulating promoter activities. This observation is supported by in vivo genomic footprinting studies that reveal persistent protections in the following motifs of this region: -141 TRE, -131 GT, -123 ETS-like, and -111 TRE-like motifs and in the enhanced protections in -141 TRE and -111 TRE-like motifs in cells after the TPA treatment. Site-directed mutagenesis in this region demonstrates the involvement of both -141 TRE and -111 TRE-like motifs in TPA/c-JUN-dependent stimulation as well as enhanced basal transcriptional activity. However, it is primarily the -111 TRE-like motif that is involved in the mediation of the enhanced basal promoter activity of the human SPR1 gene. These results are further supported by gel mobility shift assays that demonstrate the involvement of c-JUN and these TRE motifs in the formation of the DNA-protein complex.

Amino Acid Sequence↗
PubMed1995

DNA strand breakage and base modification induced by hydrogen peroxide treatment of human respiratory tract epithelial cells.

Treatment of human respiratory tract epithelial cells with H2O2 led to concentration-dependent DNA strand breakage that was highly-correlated with multiple chemical modifications of all four DNA bases, suggesting that damage is due to hydroxyl radical, OH. However, the major base damage occurred to adenine. Hence, conclusions made about the occurrence and the extent of oxidative DNA damage on the basis only of changes in 8-hydroxyguanine should be approached with caution.

Bronchi↗
PubMed1995

Effects of exposure to environmental tobacco smoke on a human tracheobronchial epithelial cell line.

BEAS-2B cells, a human bronchial epithelial line immortalized by viral transformation, were exposed to sidestream tobacco smoke (STS) as a surrogate for environmental tobacco smoke (ETS) under biphasic culture conditions where the apical portion of the cells was in direct contact with the gas phase. Dose-dependent cytotoxicity was observed. In addition, induction of an as yet uncharacterized protein of molecular weight 45,000 was associated with exposure to STS. This protein might be part of a protective response of exposed cells, which do not show a classical heat shock response when exposed to STS. We conclude that STS and ETS can be directly cytotoxic to human airway epithelial cells in biphasic culture at concentrations not unreasonable for smoky indoor atmospheres. The model system described in this paper should be useful for studying the detailed mechanisms of cytotoxicity of, and protection from, ETS exposure in the human cells most directly exposed to ETS in vivo.

Bronchi↗