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Q Yang

Publications and source records attributed to Q Yang.

At least 415 records · Page 23Linked to original sources
PubMed1995

[Prognostic factors in curative resection of stomach carcinoma. A uni- and multivariate analysis].

The TNM system, including tumor infiltration (T category), lymph node infiltration (N category) and metastasis (M category), is a well-established system of prognostic factors. To evaluate the prognostic importance of patient characteristics and tumor parameters 5 clinical and 13 pathological factors were analyzed. Data on 200 consecutive patients with histologically verified stomach cancer were prospectively recorded using a standardized form. In the subgroup with curative resection (R0, n = 108) a uni- and multivariate analysis was performed with respect to 5-year survival. In the univariate analysis statistical significance was demonstrated for the following factors: tumor size, tumor localization, T category, N category, number of infiltrated lymph nodes infiltrated, lymph node compartments, tumor stage, lymph node ratio: infiltrated/inspected. Multivariate analysis, taking into consideration the interaction between prognostic factors, revealed only two factors as statistically significant: number of infiltrated lymph nodes and tumor size. Our results and those in the literature indicate that the infiltration of lymph nodes is the most relevant prognostic factor. In addition to the TNM system the number of infiltrated lymph nodes seems to be of prognostic importance.

Adult↗
PubMed1995

Phosphorylated and non-phosphorylated neurofilament proteins: distribution in the rat hippocampus and early changes after kainic acid induced seizures.

The regional distribution of neurofilament proteins in the rat hippocampus and their early changes after kainic acid induced seizures were investigated immunocytochemically with antibodies against light weight neurofilament, phosphorylated and non-phosphorylated heavy weight neurofilament. The light weight and non-phosphorylated heavy weight neurofilaments were distributed more unevenly than the phosphorylated neurofilament. The perikarya and processes of pyramidal cells in the CA3 field contained the highest light weight and non-phosphorylated heavy weight neurofilaments, while the perikarya of granule cells contained only few light weight neurofilament and the perikarya of CA1 pyramidal cells were even devoid of immunoreactivity of both light and heavy weight neurofilaments. The fiber staining of the light weight and non-phosphorylated heavy weight neurofilaments, especially the former, was less in the CA1 field and molecular layer of dentate gyrus. The phosphorylated neurofilament immunoreactivity was identified only in axons. Mossy fibers, the axons of granule cells, contained the light weight and phosphorylated heavy weight neurofilaments, but not the non-phosphorylated neurofilament. Seven days after the kainic acid induced seizures, the phosphorylated neurofilament staining was greatly reduced in the CA1 and inner molecular layer of the dentate gyrus, probably resulting from the axonal degeneration of the Schaffer collaterals and the commissural/associational fibers. Furthermore, the nonphosphorylated neurofilament appeared in the mossy fibers of the CA3 stratum lucidum, which normally do not express such immunoreactivity. The results indicate that the neurofilaments are altered following the neuronal degeneration and postlesional plasticity caused by the kainic acid administration. Therefore, the examination of various phosphorylated neurofilaments may offer a comprehensive understanding of major hippocampal pathways, axonal plasticity and the possible roles of neurofilaments in the hippocampus following excitotoxic insults.

Animals↗
PubMed1995

Electrocardiographic interactions between pinacidil, a potassium channel opener and class I antiarrhythmic agents in guinea-pig isolated perfused heart.

1. Drugs that shorten action potential duration could decrease the Na-channel blocking effect of class I antiarrhythmic agents by reducing the availability of Na channel in the inactivated state. 2. This hypothesis was tested in guinea-pig perfused heart, measuring the surface ECG effects of three class I drugs endowed with different binding kinetics (15 microM mexiletine, 10 microM quinidine and 3 microM flecainide) in the presence of increasing concentrations of pinacidil (10 microM, 30 microM, 50 microM), a potassium channel opener that shortens action potential duration. 3. The ECG parameters measured were: the QRS interval, i.e. the intraventricular conduction time; the JT interval, which reflects the duration of ventricular repolarization; the ratio between JT peak (the time from the end of QRS and the peak of T wave) and JT interval, which quantifies changes in the morphology of the T wave. 4. At the concentrations tested all the antiarrhythmic drugs widened the QRS complex by 55-60%. Flecainide did not significantly change JT interval, but quinidine prolonged and mexiletine shortened it. Mexiletine also decreased the JT peak/JT ratio. Pinacidil by itself decreased the JT interval and the JT peak/JT ratio in a dose-dependent way, but did not affect QRS duration. 5. In the presence of fixed antiarrhythmic drug concentrations, however, pinacidil decreased the QRS prolongation induced by mexiletine (-17%) and quinidine (-8%), but not that induced by flecainide: this effect was already maximal at the lower concentration tested (10 microM) and there was no relationship between pinacidil-induced JT shortening and QRS changes. To explain this unexpected result it has been supposed that, at the driving frequency used (4 Hz), myocardial cells were partially depolarized and that pinacidil could repolarize them, thus decreasing the number of inactivated Na channels and the effects of drugs that (mainly or partly) block the channels in the inactivated state. In agreement with this hypothesis, an additional series of experiments carried out with 15 microM mexiletine at a lower stimulation rate (2 Hz) showed only a negligible loss of QRS effect (- 2.3%) at any pinacidil concentration.6. Flecainide, but not quinidine and mexiletine, antagonized the JT shortening induced by pinacidil;furthermore, no drug modified the JTp/JT decrease induced by pinacidil.7. These results indicate that: (a) an antagonism between class I antiarrhythmic drugs and pinacidil is possible; (b) mexiletine is the most involved among the drugs tested; (c) the interaction is not related to pinacidil-induced repolarization shortening, but probably to changes in membrane resting potential. The possible clinical implications need to be defined.

Action Potentials↗
PubMed1995

CD3 and CD2 ligation alters CD49d epitope expression.

The combination of anti-CD2 plus anti-CD3 monoclonal antibodies (mAbs) synergistically prolongs allograft survival and induces antigen-specific tolerance. Since altered expression of cell surface molecules might be important for tolerance induction, the effect of anti-CD2 and anti-CD3 mAbs on the expression of adhesion molecules was analyzed on splenic T cells with an in vitro model. The anti-CD2 mAb, 12-15, alone had no effect on the expression of integrin alpha 4-chain epitopes recognized by two anti-CD49d (VLA-4 alpha) mAbs, R1-2 and PS/2. The anti-CD3 mAb, 2C11, caused R1-2 epitope expression to decrease, while PS/2 epitope expression remained unchanged. The combination of anti-CD2 and anti-CD3 mAbs further decreased R1-2 epitope expression while preserving PS/2 epitope expression. The expression of integrin beta 1 and beta 7 chains, each of which form heterodimers with alpha 4 chains, also remained unchanged. Expression of other integrin, selectin, or immunoglobulin superfamily molecules (CD11a, CD18, CD44, CD45, CD48, CD54 and CD62L) were all significantly increased by anti-CD2 or anti-CD3 mAbs. Decreased R1-2 epitope expression was anti-CD3 dependent and specifically augmented by anti-CD2 mAb. CD2-regulated decreases in R1-2 epitope expression correlated with increased cAMP and could be prevented by addition of high doses of IL-2 but was not affected by the addition of other cytokines. R1-2 alpha 4 epitope expression could be specifically restored by the divalent cation Mn2+, which also increased functional binding to the VCAM-1 ligand. Significantly, the R1-2 but not the PS/2 mAb prolonged graft survival in a cardiac allograft model. These results show that anti-CD2 and anti-CD3 mAbs selectively decrease integrin alpha 4 chain epitope expression on T cells through conformational regulation. Decreased expression of a CD49d epitope is unique in comparison to the up-modulation of other T-cell adhesion receptors. These changes correlate with functional effects and provide an additional mechanistic explanation for the synergistic effect of anti-CD2 plus anti-CD3 in producing tolerance.

Animals↗
PubMed1995

Increased cAMP and cAMP-dependent protein kinase activity mediate anti-CD2 induced suppression of anti-CD3-driven interleukin-2 production and CD25 expression.

Anti-CD2 monoclonal antibody (mAb) can act synergistically with anti-CD3 to produce tolerance and diminish the anti-CD3-induced cytokine syndrome. Since interleukin(IL)-2 production and IL-2 receptor (IL-2R; CD25) expression are important determinants of CD3-driven T cell activation, the effects of anti-CD2 on anti-CD3-induced CD25 expression and IL-2 production were analyzed and related mechanistically to CD2-stimulated cAMP signaling with an in vitro model of T cell activation. The anti-CD2 mAb, 12-15, alone had no effect on splenic T cell CD25 expression and IL-2 production, while the anti-CD3 mAb, 145-2C11, caused significant increases in both CD25 expression and IL-2 production. The addition of anti-CD2 inhibited anti-CD3-induced increases in CD25 and IL-2. The inhibitory signal delivered by anti-CD2 was effective in many forms of T cell activation, since other stimuli which increased CD25, such as concanavalin A, phytohemagglutinin, and Staphylococcal enterotoxin B (SEB), could also be inhibited by anti-CD2. The inhibitory effect of anti-CD2 on CD25 could not be reversed by high doses of supplemental IL-2 added to the culture. Anti-CD2 increased cytoplasmic cAMP in a dose- and time-dependent manner. Reagents that increased cytoplasmic cAMP such as forskolin, cholera toxin, and 3'-isobutyl-1-methylxanthine could mimic the inhibitory effect of anti-CD2 on anti-CD3-driven CD25 expression. Anti-CD2 also increased the activity of cAMP-dependent protein kinase (PKA). H8, a PKA antagonist, blocked the inhibitory effect of anti-CD2 on CD25 expression, further confirming the role of PKA in CD2-induced negative signaling. The use of paired agonists to PKA demonstrated that a type I PKA was the preferential enzyme isoform stimulated by CD2 ligation. These findings show that increased cAMP and PKA activity mediate anti-CD2-induced suppression of anti-CD3-driven IL-2 production and CD25 expression, and provide mechanisms for anti-CD2-induced immunosuppression and inhibition of the cytokine syndrome associated with anti-CD3 treatment.

Animals↗
PubMed1995

Characterization of LDL and VLDL binding sites on human basophils and mast cells.

Recent data suggest that basophils and mast cells play a potential role in the processing and accumulation of plasma lipoproteins. This study investigated the interactions of 111In-low-density lipoprotein (LDL), 111In-acetyl-LDL, and 111In-very-low-density lipoprotein (VLDL) with purified primary human blood basophils, immortalized human basophils (KU812 cell line), and a human mast cell line, HMC-1. Binding sites for 111In-LDL resolved into curvilinear Scatchard plots indicating two classes of specific binding sites on primary basophils (Bmax1, 7404 sites/cell; Kd1, 1.9 nmol/L; Bmax2, 39,611 sites/cell; Kd2, 29 nmol/L), on KU812 cells (Bmax1, 8290 +/- 2690 sites/cell; Kd1, 2.4 +/- 0.6 nmol/L; Bmax2, 46,470 sites/cell; Kd2, 33.4 +/- 7.8 nmol/L), and on HMC-1 cells (Bmax1, 7840 +/- 360 sites/cell; Kd1, 1.8 +/- 0.8 nmol/L; Bmax2, 61,450 +/- 9900 sites/cell; Kd2, 28.4 +/- 9.4 nmol/L). On KU812 cells, binding of 111In-LDL was displaced by apolipoprotein (apo)-E-rich high-density lipoprotein (HDL) (IC50, 14 +/- 6 nmol/L), LDL (IC50, 29 +/- 11 nmol/L), VLDL (IC50, 55 +/- 21 nmol/L), HDL2 (IC50, 420 +/- 140 nmol/L), and heparin (IC50, 67 +/- 28 nmol/L), whereas no competition was produced by HDL, HDL3, or acetyl-LDL (IC50, > 1 mumol/L). Western blot analysis using the monoclonal antibody C7 confirmed the presence of the LDL receptor on human basophils and HMC-1 cells. 111In-acetyl-LDL binding sites (scavenger receptor) could be detected neither on human basophils nor on HMC-1 cells. 111In-VLDL bound to a single class of high-affinity binding sites on primary basophils (Bmax, 4320 sites/cell; Kd, 10 nmol/L), KU812 cells (Bmax, 4020 +/- 840 sites/cell; Kd, 8 +/- 3 nmol/L), and HMC-1 cells (Bmax, 6143 +/- 1866 sites/cell; Kd, 4 +/- 2 nmol/L). 111In-VLDL binding was displaced by VLDL > LDL > apoE-rich HDL but not by heparin (IC50 > 1 mmol/L). In the presence of prostaglandin E1, the number of 111In-LDL receptors increased by 150% (P < .05) in the high-affinity range and by 170% (P < .01) in the low-affinity range, whereas the number of 111In-VLDL binding sites remained unchanged. VLDL, LDL, HDL, and the subclasses HDL2 and HDL3 inhibited immunological histamine release by primary normal basophils (n = 3) and mast cells (n = 3). Our results provide evidence for the existence of LDL and VLDL binding sites on human basophils and HMC-1 mast cells. The exact biological and pathophysiological roles of these sites remain to be elucidated.

Basophils↗
PubMed1995

[Alteration of phospholamban phosphatase activity associated with cardiac sarcoplasmic reticulum during sepsis in rats].

In the present study, rat cardiac sarcoplasmic reticulum (SR) phospholamban (PLB) phosphatase was partially purified by chromatography on DEAE-Sephacel. This PLB phosphatase was indentical to phosphatase-1. It was shown on electrophoresis of SDS-PAGE autoradiography that the PLB phosphatase in rats during early sepsis (ES) depressed dephosphorylation of substrates (32P-phosphorylase a and 32P-SR). However, dephosphorylation of the substrates by the partially purified phosphatase during late sepsis (LS) was same as that in control rats. The partially purified PLB phosphatase activity in ES rats was significantly decreased, but showed no change in LS rats. The results above were confirmed by a studing of the substrate concentration (enzyme concentration, time)--enzyme reaction velocity curve in showing that both affinity and maximum initial velocity (Vmax) of the phosphatase in the ES rats were decreased, but had no change in those in the LS rats.

Adenosine Triphosphatases↗
PubMed1995

[Study on effect of polysaccharides of ginseng on peripheral blood mononuclear cell induced interleukin-2 production and activity of its receptors in vitro].

To study the effect of polysaccharides of Ginseng (PSG) on cellular-immunity from healthy subjects and patients of kidney disease, the peripheral blood mononuclear cell (PBMC) induced interleukin-2 (IL-2) were assayed in vitro. It was found that the PSG could prommote the PBMC induced IL-2 in the healthy subjects and patients with kidney diseases and was dose-dependent. This study revealed that PSG was worthwhile to be further studied as an approach of biological responsive modifier therepy in treating human immunodeficiency diseases.

Adolescent↗
PubMed1995

Diagnostic scores for acute appendicitis. Abdominal Pain Study Group.

OBJECTIVE: To assess the value of predictive scores in the diagnosis of acute appendicitis. DESIGN: Multicentre evaluation with a prospective database. SUBJECTS: 1254 patients with acute abdominal pain. SETTING: 6 departments of surgery, Germany. INTERVENTIONS: To measure the performance of 10 scores on one database using standardised criteria and to compare the results with published data. MAIN OUTCOME MEASURES: The ability of a score to fulfill standardised criteria: an initial negative appendicectomy rate of 15% or less, a potential perforation rate of 35% or less, an initial missed perforation rate of 15% or less, and a missed appendicitis rate of 5% or less. RESULTS: Reevaluation of the published data showed that the Alvarado score fulfilled all four criteria and the Lindberg, the Fenyö and the Christian scores fulfilled two criteria each. If applied to our database (acute abdominal pain, suspected appendicitis), none of the scores fulfilled any of the given criteria, even if the cut-off point was varied systematically. There were significant differences among the scores. CONCLUSIONS: The original published data seemed to comply with our standardised criteria but evaluation of the scores on our database resulted in poor performances for all of them. Published data seem to be optimistically biased whereas our evaluation gives more realistic estimates of the routine performance in different clinical environments. Further well designed large scale trials are needed to investigate the clinical benefit of diagnostic scoring in acute appendicitis.

Abdominal Pain↗
PubMed1995

[Antitussive, expectorant and anti-asthmatic effects of Cynanchum glaucescens (Decne.) Hand. -Mazz].

The water, ethanol and ether extracts from Cynanchum glaucescems administrated orally showed significant antitussive effect in ammonia-induced cough model in mice. The water and ethanol extracts had obvious expectorant effect. The filtered solution of water decoction injected intraperitoneally could effectively prevent guinea pigs from asthma induced by acetulcholine and histamine mixture, and also inhibit the ear inflammation in mice caused by croton oil. All these effects showed close dose-effect relationship.

Animals↗
PubMed1995

[A study on the mechanism of the cardiac adenylyl cyclase activity alteration in septic rats].

The present work showed that cardiac sarcolemmal (SL) adenylyl cyclase (AC) and purified AC maximal activity of septic rat (cecal ligaation and puncture, CLP) were significantly increased during the early sepsis (ES, CLP 9 h) but decreased in the late sepsis (LS, CLP 18 h). Similar alterations were observed in cardiac sarcolemmal protein kinase C (PKC) activity. Sensitization and desensitization of rat SL adenylyl cyclase during ES and LS were respectively correlated with activition and inhibition of PKC. The biphasic changes of AC and PKC were independent of beta- and alpha 1-adrenergic receptor systems. The rat cardiac sarcolemmal PKC activation and AC sensitization during ES is related to M-cholinergic receptor system. The system, however, is not involved during the LS PKC inhibition and AC desensitization.

Adenylyl Cyclases↗
PubMed1995

[Diagnostic score for acute appendicitis].

Scoring systems seem to be ideal for supporting diagnosis of acute appendicitis because they are non invasive, require no special equipment and can be used in clinical routine. Several scores for appendicitis have been developed with good results in the original publications. Unfortunately these good results could not be reproduced on a German data base. Therefore we developed a new score using multivariate statistics and a quality controlled prospective data base. The score covers 8 variables: tenderness, rebound tenderness, micturition, type of pain, leucocytes, age, relocation of pain, rigidity. Independent evaluation of the score on a Dutch database resulted in a negative appendicectomy rate of 21% and a missing appendicitis rate of 2%. The results are encouraging, so that further testing and clinical application can be recommended.

Acute Disease↗
PubMed1995

[A comparative study on the effect of absorbable components of several drugs on the growth and population doublings of rat diploid fibroblast].

Embryonic skin fibroblast of Sprague-Dawley rats cultivated in vitro was used in this experiment. The cultural medium was added with absorbable components of several drugs. The result reveals that Yan Shou recipe, vitamin E and Huan Jing Jian have conspicuous promotive effect on the growth of diploid fibroblast and also help to increase population doublings. The experiment suggests that all these drugs possess anti-aging effect on the skin diploid fibroblast of rats.

Aging↗
PubMed1995

Genetic resistance against acute toxoplasmosis depends on the strain of Toxoplasma gondii.

The role of the strain of Toxoplasma gondii in genetic control of resistance against acute infection with T. gondii was studied with 2 strains of T. gondii, which differ in their virulence and genotype. Following peroral infection with 10 cysts of the C56 strain, C57BL/6 (H-2b) and C3H/HeN (H-2k) mice died significantly earlier than BALB/c mice (H-2d) mice, although all of the mice eventually died of acute toxoplasmosis from 10 to 23 days after infection. There was no significant difference in time to death between C57BL/6 mice and C3H/HeN mice. In peroral infection with 100 cysts of the less virulent ME49 strain, all C57BL/6 mice died of acute toxoplasmosis from 7 to 10 days after infection. C57BL/6 mice died significantly earlier following infection with the ME49 strain than with the C56 strain, whereas all C3H/HeN mice infected with the ME49 strain survived as did BALB/c mice. These results indicate that genetic control of resistance against acute infection with T. gondii differs depending on the strain of T. gondii.

Acute Disease↗
PubMed1995

High-level expression of human beta-interferon gene in the silkworm with new constructed BmNPV vector.

Bombyx mori nuclear polyhedrosis virus (BmNPV) and Bombyx mori cells as well as silkworm larvae were used successfully for the production of biologically active recombinant proteins. There are only a few types of BmNPV general vectors. Here a new type of vector plasmid pBm92 was constructed in this experiment. The translational initiation codon ATG of the polyhedrin gene in Pbm92 was changed into ATT, and then five cloning sites of a foreign gene were ligated after the +12 bp site of the polyhedrin gene. Human beta-interferon (HuIFN-beta) gene was cloned into Pbm92 to construct pBmIFN +12; meanwhile we constructed the transfer vector Pbmifn-3 in which HuIFN-beta was cloned after the -3 bp site of the polyhedrin gene. BM-N cells were cotransfected with the two types of transfer vector plasmid DNAs and BmNPV genomic DNA. Recombinant viruses that were screened did not produce polyhedrin inclusion bodies in the virus plaque assay, and were identified by the hybridization of recombinant virus DNA with HuIFN-b gene probe. IFN activity of the culture media of Bm-N cells infected with recombinant virus BmIFN +12 was 2.0 x 10(6) IU/mL, and IFN activity of hemolymph of silkworm larvae infected with BmIFN +12 was 5.0 x 10(7) IU/mL. Expression level of BmIFN +12 was two to four times more than that of BmIFN -3. The rHuIFN-beta produced by BM-N cells and silkworm larvae has an antigenicity identical to that of the native HuIFN-beta.

Animals↗