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Biomedical subjects

Q Yang

Publications and source records attributed to Q Yang.

At least 289 records · Page 16Linked to original sources
PubMed1998

Epitope mapping of HTLV envelope seroreactivity in LGL leukaemia.

Sera from approximately 50% of patients with large granular lymphocyte (LGL) leukaemia react with a recombinant human T-cell leukaemia/lymphoma virus (HTLV) transmembrane envelope protein, p21e. Two immunodominant epitopes within env p21e have been defined by reactivity against recombinant proteins GD21 and BA21. In this study sera from 41 patients with LGL leukaemia were examined for reactivity against these recombinant HTLV env proteins. Overall, 21/41 (51%) sera reacted to p21e. Only two sera reacted to GD21. The predominant immunoreactivity against p21e was directed against the BA21 epitope, with 19/41 (46%) sera being BA21 positive. Seroconversion to BA21 protein was also documented. PCR analyses confirmed the low incidence of protypical HTLV sequences (2/41, 5%). These data document an association between BA21 seroreactivity and LGL leukaemia. This finding raises the possibility that such BA21 seroreactivity could be due to cross-reactivity to a cellular or retroviral antigen sharing some amino acid homology with the transmembrane glycoprotein of HTLV.

Adolescent↗
PubMed1998

A novel therapy for nocturnal polyuria: a double-blind randomized trial of frusemide against placebo.

OBJECTIVE: To report a randomized, double-blind, placebo-controlled trial of an afternoon dose of the diuretic frusemide, used to establish an early evening diuresis and so diminish nocturnal voiding frequency and voided volume in elderly men presenting with lower urinary tract symptoms (LUTS). PATIENTS AND METHODS: After a 2-week placebo run-in period, 49 men aged > 50 years were randomized to receive 40 mg of frusemide or placebo, taken 6 h before their usual bedtime. Day and night-time frequency and voided volume during the run-in and treatment periods were compared between the placebo and frusemide groups. RESULTS: In the 43 men completing the study, there was a significant reduction in night-time frequency (-0.5 and 0) and percentage night-time voided volume (-18% and 0%) in those taking frusemide compared with placebo. Of patients on active treatment, seven of 19 had a reduction in night-time frequency of > or = 1, compared with only one of 20 on placebo, and 14 of 21 felt that frusemide had helped their nocturia, compared with only five of 22 on placebo. CONCLUSION: Men with LUTS whose most prominent symptom is nocturia should complete a frequency-volume chart. In those with nocturnal polyuria, 40 mg of frusemide resulted in a significant reduction in night-time frequency and percentage voided volume.

Aged↗
PubMed1998

The ICS-'BPH' Study: uroflowmetry, lower urinary tract symptoms and bladder outlet obstruction.

OBJECTIVE: To explore the relationship between uroflow variables and lower urinary tract symptoms (LUTS): to define performance statistics (sensitivity, specificity, positive and negative predictive values) for maximum urinary flow rate (Qmax) with respect to bladder outlet obstruction (BOO) at various threshold values; and to investigate the diagnostic value of low-volume voids. PATIENTS AND METHODS: The study comprised 1271 men aged between 45 and 88 years recruited from 12 centres in Europe, Australia, Canada, Taiwan and Japan over a 2-year period. Symptom questionnaires, voiding diaries, uroflowmetry and pressure-flow data were recorded. The relationship between uroflow variables and symptoms, Qmax and BOO, and the diagnostic performance of low volume voids were analysed. RESULTS: The relationship between symptoms and uroflow variables was poor. The mean difference between home-recorded and clinic-recorded voided volumes was -48 mL. Qmax was significantly lower in those with BOO (9.7 mL/s for void 1) than in those with no obstruction (12.6mL/s; P<0.001) and Qmax was negatively correlated with obstruction grade (Spearman's correlation coefficient -0.3, P<0.001), even when controlling for the negative correlation between age and Qmax (Spearman's partial correlation coefficient -0.29, P<0.001). A threshold value of Qmax of 10 mL/s had a specificity of 70%, a positive predictive value (PPV) of 70% and a sensitivity of 47% for BOO. The specificity using a threshold Qmax of 15 mL/s was 38%, the PPV 67% and the sensitivity 82%. Those voiding <150 mL (n=225) had a 72% chance of BOO (overall prevalence of BOO 60%). In those voiding >150 mL the likelihood of BOO was 56%. The addition of a specific threshold of 10 mL/s to these higher volume voiders improved the PPV for BOO to 69%. CONCLUSION: While uroflowmetry cannot replace pressure-flow studies in the diagnosis of BOO. it can provide a valuable improvement over symptoms alone in the diagnosis of the cause of lower urinary tract dysfunction in men presenting with LUTS. This study provides performance statistics for Qmax with respect to BOO: such statistics may be used to define more accurately the presence or absence of BOO in men presenting with LUTS, so avoiding the need for formal pressure-flow studies in everyday clinical practice, while improving the likelihood of a successful outcome from prostatectomy. This study also shows that low-volume uroflowmetry can provide useful diagnostic information and that, as such, the data from such voids should not be discarded.

Aged↗
PubMed1998

Cytokine interactions promote synergistic fibronectin accumulation by mesangial cells.

BACKGROUND: The development of glomerulosclerosis has been associated with the presence of the cytokines transforming growth factor-beta 1 (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha) and/or interleukin-1 beta (IL-1 beta), at some stage in the glomerulus. To better understand the role of these cytokines in the scarring process their effect on rat mesangial cell fibronectin production was investigated. METHODS: Mesangial cells were exposed to 10 ng/ml of either TGF-beta 1, TNF-alpha, or IL-1 beta or to TGF-beta 1 in combination with TNF-alpha or IL-1 beta. Tissue culture supernatants and cell lysates were assayed for fibronectin. Supernatants were also assayed for TGF-beta 1. Northern blot analyses probing for fibronectin, transin, TIMP-1 and TGF-beta 1 were carried out on RNA extracted from mesangial cells exposed to individual and combinations of cytokines. RESULTS: Individually these cytokines were only able to induce modest increases in fibronectin protein levels. However, when mesangial cells were exposed to TGF-beta 1 in combination with either TNF-alpha or IL-1 beta then fibronectin levels were synergistically up-regulated approximately fivefold over unstimulated levels. Northern analysis demonstrated that fibronectin mRNA levels in the combination were also synergistically increased. In contrast, rat transin gene expression in the combinations was reduced to well below levels induced by TNF-alpha and IL-1 beta individually. In addition, synergistic up-regulation of both TGF-beta 1 protein and message by the cytokine combinations was also observed. TGF-beta 1: TNF-alpha and TGF-beta 1: IL-1 beta induced additive increases in TIMP-1 (tissue inhibitor of metalloproteinases-1) mRNA levels. CONCLUSIONS: These data illustrate that complex interactions can occur between cytokines within the glomerulus modulating both matrix synthetic and degradation pathways. These could initiate the scarring process and the development of glomerulosclerosis.

Animals↗
PubMed1998

Simple data from history and physical examination help to exclude bowel obstruction and to avoid radiographic studies in patients with acute abdominal pain.

OBJECTIVE: To assess the value of plain abdominal radiographs and of data from the medical history and physical examination in the diagnosis of acute abdominal pain in general and of bowel obstruction in particular. DESIGN: Prospective study. SETTING: 4 university and 2 community hospitals, Germany. SUBJECTS: 1254 patients with acute abdominal pain lasting less than 7 days, and with no history of abdominal injury including surgery. INTERVENTIONS: Standardised and structured medical history and physical examination, study of results of plain abdominal radiographs. MAIN OUTCOME MEASURES: Positive predictive value and sensitivity of clinical variables and abdominal film with respect to the diagnosis at discharge. RESULTS: 48 patients (3.8%) had bowel obstruction. 704 patients (56.1%) had plain abdominal films taken at the time of initial presentation. 111 studies (15.8%) showed important findings leading to diagnosis or immediate treatment, 455 (64.7%) showed unimportant or no findings. In 138 (19.6%) results of films were not reported. 16 of 45 single variables were of help in diagnosing bowel obstruction. The six with the highest sensitivity were distended abdomen, increased bowel sounds, history of constipation, previous abdominal surgery, age over 50, and vomiting. If only patients presenting with any two of these symptoms had had radiographs taken, 300 (42.6%) could have been avoided without loss in diagnostic accuracy. CONCLUSION: A considerable number of plain abdominal films taken for patients with acute abdominal pain could be avoided by focusing on clinical variables relevant to the diagnosis of bowel obstruction.

Abdominal Pain↗
PubMed1998

Relevance of extracellular matrix, its receptors, and cell adhesion molecules in mammalian nephrogenesis.

Mammalian nephrogenesis begins by the reciprocal interaction of the ureteric bud with the undifferentiated mesenchyme. The mesenchyme differentiates into an epithelial phenotype with the development of the glomerulus and proximal and distal tubules. At the same time, the mesenchyme stimulates the branching morphogenesis of the ureteric bud that differentiates into the collecting ducts. These inductive interactions and differentiation events are modulated by a number of macromolecules, including the extracellular matrix (ECM), integrin receptors, and cell adhesion molecules. Many of these macromolecules exhibit spatiotemporal developmental regulation in the metanephros. Some are expressed in the mesenchyme, whereas others appear in the ureteric bud epithelia. The molecules expressed in the mesenchyme or at the epithelial:mesenchymal interface may serve as ligands while those in the epithelia serve as the receptors. In such a scenario the ligand and the receptor would be ideally suited for epithelial:mesenchymal paracrine/juxtacrine interactions that are also influenced by RGD sequences and Ca2+ binding domains of the ECM proteins and their receptors. This review addresses the role of such interactions in metanephric development.

Animals↗
PubMed1998

Isolation of rat fibrillin-1 cDNA and its relevance in metanephric development.

The role of fibrillin-1 in metanephrogenesis was investigated. Fibrillin-1 cDNA was isolated from the rat kidney cDNA library and sequenced, and its spatiotemporal expression was studied. It had approximately 88% homology with human fibrillin-1 and had Ca2+ binding epidermal growth factor-like domains, transforming growth factor-beta binding protein motifs, and an RGD binding site. Northern blot analysis revealed an approximately 10-kb transcript, and fibrillin-1 expression was developmentally regulated. In situ hybridization and immunofluorescence studies indicated that at day 15 of gestation, fibrillin-1 is expressed in the metanephric mesenchyme. At day 18, its expression was confined to nascent blood vessels and glomeruli, and it increased in the newborn and neonatal kidneys. Immunoprecipitation revealed an approximately 300-kDa band by SDS-PAGE. Treatment with fibrillin-1 antisense oligodeoxynucleotide induced marked dysmorphogenesis of the embryonic metanephroi. Concomitantly, the fibrillin-1 mRNA, antibody reactivity in the metanephroi, and fibrillin-1-specific radioincorporation were reduced. These data indicate that, like alphavbeta3 integrin, a known morphogen and a putative receptor of fibrillin-1, the fibrillin-1 modulates events related to early organogenesis and possibly also the vascularization of the rat kidney.

Amino Acid Sequence↗
PubMed1998

Prediction of stroke outcome with echoplanar perfusion- and diffusion-weighted MRI.

OBJECTIVES: We examined the utility of echoplanar magnetic resonance perfusion imaging and diffusion-weighted imaging (DWI) in predicting stroke evolution and outcome in 18 patients with acute hemispheric infarction. METHODS: Patients were studied within 24 hours (mean, 12.2 hours), subacutely (mean, 4.7 days), and at outcome (mean, 84 days). Comparisons were made between infarction volumes as measured on perfusion imaging (PI) and isotropic DWI maps, clinical assessment scales (Canadian Neurological Scale, Barthel Index, and Rankin Scale), and final infarct volume (T2-weighted MRI). RESULTS: Acute PI lesion volumes correlated with acute neurologic state, clinical outcome, and final infarct volume. Acute DWI lesions correlated less robustly with acute neurologic state, but correlated well with clinical outcome and final infarct volume. Three of six possible patterns of abnormalities were seen: PI lesion larger than DWI lesion (65%), PI lesion smaller than DWI lesion (12%), and DWI lesion but no PI lesion (23%). A pattern of a PI lesion larger than the DWI lesion predicted DWI expansion into surrounding hypoperfused tissue (p < 0.05). In the other two patterns, DWI lesions did not enlarge, suggesting that no significant increase in ischemic lesion size occurs in the absence of a larger perfusion deficit. CONCLUSIONS: Combined early PI and DWI can define different acute infarct patterns, which may allow the selection of rational therapeutic strategies based on the presence or absence of potentially salvageable ischemic tissue.

Adult↗
PubMed1998

Mutation P291fsinsC in the transcription factor hepatocyte nuclear factor-1alpha is dominant negative.

The type 3 form of maturity-onset diabetes of the young (MODY3) results from mutations in the gene encoding the transcription factor, hepatocyte nuclear factor-1alpha (HNF-1alpha). The mechanism by which mutations in only one allele of the HNF-1alpha gene impair pancreatic beta-cell function is unclear. The functional form of HNF-1alpha is a dimer--either a homodimer or a heterodimer with the structurally related protein HNF-1beta--that binds to and activates transcription of the genes whose expression it regulates. HNF-1alpha is composed of three functional domains: an amino-terminal dimerization domain (amino acids 1-32), a DNA-binding domain with POU-like and homeodomain-like motifs (amino acids 150-280), and a COOH-terminal transactivation domain (amino acids 281-631). Because the dimerization domain is intact in many of the mutant forms of HNF-1alpha found in MODY subjects, these mutant proteins may impair pancreatic beta-cell function by forming nonproductive dimers with wild-type protein, thereby inhibiting its activity; that is, they are dominant-negative mutations. This hypothesis was tested by comparing the functional properties of the frameshift mutation P291fsinsC, the most common mutation identified to date in MODY3 patients, and wild-type HNF-1alpha. P291fsinsC-HNF-1alpha showed no transcriptional transactivation activity in HeLa cells, which lack endogenous HNF-1alpha. Overexpression of P291fsinsC-HNF-1alpha in MIN6 cells, a mouse beta-cell line, resulted in an approximately 40% inhibition of the endogenous HNF-1alpha activity in a dosage-dependent manner. Furthermore, heterodimer formation between wild-type and P291fsinsC mutant proteins were observed by electrophoretic mobility shift assay. These data suggest that the P291fsinsC mutation in HNF-1alpha functions as a dominant-negative mutation. However, other mutations, such as those in the promoter region and dimerization domain, may represent loss of function mutations. Thus mutations in the HNF-1alpha gene may lead to beta-cell dysfunction by two different mechanisms.

Animals↗
PubMed1998

[A case-control study on the risk factors of accidental injury among 0-14 year-old children].

To investigate the risk factors resulting in accidental injury in children and to provide basis for the prevention and reduction of such incidence, 468 cases of children with accidental injuries were studied through a one to one matched case-control study. Data was analysed with conditional logistic analysis. Results from single-factor analysis showed that such cases were associated with following factors: a) multiple children in the family with parents illiterate or low income; b) pesticide or raticide was stored inside the rooms; c) negligence of the dangerous environment risk around their houses. Results from multiple-factors analysis showed that children with illiterate parents, house that had pesticide stored in, low family income and whose houses were under vulnerable condition of collapse were most likely to suffer accidental injuries. Author concluded that the accidental injuries to children were caused by multiple factors which are preventable.

Accidents↗
PubMed1998

[Studies on stroke and blood lipid level].

OBJECTIVE: To elucidate the relationship between blood lipid levels and cerebrovascular diseases. METHODS: Seven indicators for blood lipid were determined in 208 patients with cerebrovascular diseases. Triglyceride (TG), total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) were measured with enzyme methods, apolipoprotein A-I, apolipoprotein B-100 (Apo-B100) and lipoprotein (alpha) [Lp(alpha)] were measured with immune multifocal method, and low-density lipoprotein-cholesterol (LDL-C) was calculated according to Friedewald formula. RESULTS: Levels of TG, TC, LDL-C, Apo-B100 and Lp(alpha) in patients with cerebral infarction were significantly higher than those in the controls, and levels of TG and Apo-B100 in them were also significantly higher than those in the patients with cerebral hemorrhage. There was no significant difference in blood lipid levels between the patients with cerebral hemorrhage and the controls. CONCLUSION: It suggests that disturbance of blood lipid metabolism is a risk factor for cerebral infarction.

Aged↗
PubMed1998

[Application of MEDPOR surgical implant in the craniofacial reconstruction].

Since November 1996, 20 cases of craniofacial deformities, either from congenital or traumatic, were treated with MEDPOR surgical implant made from a linear high density polythylene. The animal experiment had shown that the MEDPOR had good organotrophic characteristics allowing tissue ingrowth. The biocompatibility studies in vitro and in vivo had shown that the MEDPOR biomaterial was free from any observable systemic or cytotoxic effect. In the clinical application, it was found that the MEDPOR could be easily modeled and maintained. Because of the ability to induce tissuee ingrowth, the tenacity and stability of the material were enhanced. A total of seven cases of cranial defects, 8 cases of periobital defects or depressed periobital regions, 2 cases of traumatic auricular defects, 2 cases of traumatic saddle nose and 1 case of maldevelopment of mandible angle were treated. All of the cases were followed up for 6 months, the results were satisfactory.

Adult↗
PubMed1998

[A clinical analysis of 94 cases of recurrent stroke].

Ninety-four cases of recurrent stroke were analyzed retrospectively, and 290 cases of first stroke episode were selected as controls. Results showed that recurrent stroke mainly appeared within the first year after the initial episode males predominant. The clinical manifestations of recurrent stroke were variable and commonly more severe. No significant differences was observed between the groups with respect to a variety of factors including the presence of hypertension, diabetes, history of transient ischemic attack, or familial history of stroke, cardiac attacks, cigarette smoking and/or alcohol consumption. The risk factors for recurrent stroke were discussed.

Cerebral Hemorrhage↗
PubMed1998

[Effect of dietary intake on body mass index in middle aged and elderly population].

The paper investigated and analyzed the relationship between the nutrient intake and body mass index (BMI) of 200 middle-aged and elderly people(aged 35 - 74 years) in Changsha. The result showed that the constituent rate of underweight (BMI< 18.5) was 6.5% and that of over-weight (BMI<25.0) was 23.5%. The amount of fat intake constituted slightly higher proportion in energy intake. The stepwise regression analysis indicates that the body mass index increases with the increasing intake of carbohydrates.

Adult↗
PubMed1998

[Effect of mifepristone on the concentration of epidermal growth factor in serum and villi of early pregnant women].

OBJECTIVE: To investigate the change of epidermal growth factor (EGF) concentration in serum and villi of early pregnant women and its possible effects by mifepristone. METHODS: Twenty normal women as control and sixty-six early pregnant women were enrolled for study. Serum EGF, estradiol (E2) and progesterone (P) concentrations were measured with radioimmunoassay. EGF concentration in villi by surgical aspiration and mifepristone induced abortion were compared. RESULTS: Serum EGF concentration in early pregnant women was significantly higher than that in non-pregnant women (P < 0.01). The serum EGF, E2 and P concentrations increased as pregnancy advanced (P < 0.05). The growth rate of gestational sac declined and serum EGF and P concentrations decreased slightly after administration of mifepristone. Villi EGF content in mifepristone group was significantly lower than that in surgical group (P < 0.05). CONCLUSION: EGF may be involved in regulating embryo development. Mifepristone may interfere embryonic development via inhibiting EGF level.

Abortifacient Agents, Steroidal↗