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S Qin

Publications and source records attributed to S Qin.

At least 109 records · Page 6Linked to original sources
PubMed1996

Expression of monocyte chemoattractant protein-1 and interleukin-8 receptors on subsets of T cells: correlation with transendothelial chemotactic potential.

The differential expression of chemokine receptors may be an important mechanism for the regulation of T cell migration. To test this, we examined the expression and function of the monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-8 receptors on various population of T cells. Using a simple and reliable transendothelial chemotaxis assay, both MCP-1 and IL-8 were shown to be chemotactic for subsets of blood T cells, although the relative response varied from donor to donor. To examine receptor expression and correlate it with chemotaxis of T cell subsets, monoclonal antibodies (mAb) to the receptors were produced by immunizing mice either with synthetic peptides (MCP-1 receptor), or with receptor transfectants (IL-8 receptors A and B). A flow cytometric analysis of blood T cells with an anti-MCP-1 receptor mAb revealed low expression on the CD26hi subset and undetectable expression on other T cells. Staining of T cells with anti-Il-8RA and anti-IL-8RB showed much higher levels of expression, but only on a subset of CD3+ cells which were CD8+ and CD56+. That IL-8 and MCP-1 attracted distinct subsets of T cells was best illustrated using the CD26 marker, since IL-8R+ T cells were CD26-, whereas T cells expressing detectable MCP-1R or which responded to MCP-1 in chemotaxis assays were CD26hi. T cells activated in vitro with anti-CD3 up-regulated expression of the MCP-1 receptor, but not the IL-8 receptors, and were attracted to MCP-1 much more efficiently than resting T cells. These results show that there is a clear distinction between the IL-8 and MCP-1-responsive T cell populations and that chemokine receptor expression on T cells may be regulated with respect to linkage as well as cellular activation.

Antibodies, Monoclonal↗
PubMed1996

Biology of chemokine and classical chemoattractant receptors: differential requirements for adhesion-triggering versus chemotactic responses in lymphoid cells.

Several chemoattractant receptors can support agonist-induced, integrin-dependent arrest of rolling neutrophils in inflamed venules in vivo, as well as subsequent crawling into tissues. It has been hypothesized that receptors of the Galpha(i)-linked chemoattractant subfamilies, especially receptors for chemokines, may mediate parallel activation-dependent arrest of homing lymphocyte subsets. However, although several chemokines can attract subsets of B or T cells, robust chemoattractant triggering of resting lymphocyte adhesion to vascular ligands has not been observed. To study the biology of individual leukocyte chemoattractant receptors in a defined lymphoid environment, mouse L1/2 pre-B cells and/or human Jurkat T cells were transfected with alpha (IL-8 receptor A) or beta (MIP-1alpha/CC-CKR-1) chemokine receptors, or with the classical chemoattractant C5a (C5aR) or formyl peptide receptors (fPR). All receptors supported robust agonist-dependent alpha4beta1 integrin-mediated adhesion of lymphocytes to VCAM-1. L1/2 cells cotransfected with fPR and beta7 integrin were also induced to bind MAdCAM-1, suggesting common mechanisms coupling chemoattractant receptors to activation of distinct integrins. Adhesion was rapid but transient, with spontaneous reversion to unstimulated levels within 5 min after peak binding. When observed under flow conditions, alpha4beta1-mediated arrest occurred within seconds after initiation of contact and rolling of IL-8RA transfectants on VCAM-1/IL-8 co-coated surface; and arrest reversed spontaneously after a mean of 5 min with a return to rolling behavior. Each of the receptors also conferred agonist-specific chemotaxis; however, whereas strong adhesion required simultaneous occupancy of many receptors with maximal responses above the Kd, chemotaxis in each case was suppressed at high agonist concentrations. The findings indicate that alpha and beta chemokine as well as classical chemoattractant receptors can trigger robust adhesion as well as directed migration of lymphoid cells, but that the requirements for and kinetics of adhesion triggering and chemotaxis are distinct, thus permitting their independent regulation. They suggest that the discordance between proadhesive and chemoattractant responses of circulating lymphocytes to many chemokines may reflect quantitative aspects of receptor expression and/or coupling rather than qualitative differences in receptor signaling.

Animals↗
PubMed1996

Detection of PML-RAR alpha in patients with APL during follow-up period.

OBJECTIVE: To evaluate the significance of PML-RAR alpha transcripts in patients with acute promyelocytic leukemia (APL) during remission period and to follow up the patients through monitoring aberrant gene expression. PATIENTS AND METHODS: This study included 17 patients with APL (5 females and 12 males). Another 19 APL patients during relapse served as control. RNA extraction was obtained through the single-step method. By means of reverse transcriptase polymerase chain reaction (PCR), the PML-RAR alpha was detected in the sample mRNA. RESULTS: Nine out of 10 patients with complete remission (CR) duration shorter than 3 years were positive. Four cases became negative and three remained positive among 7 cases in a long remission of over 3 years. The difference of the positive rate of PML-RAR alpha transcripts between the 2 groups was significant (P < 0.05). Four among 12 positive cases relapsed. No evidence of relapse was present in the 5 negative patients after 9.6 +/- 3.9-month follow-up. Further treatment was therefore given to the 4 positive patients whose treatment was already ceased at that time. By this management they were all in CR during the following 10-month observation. CONCLUSIONS: RT-PCR detection for PML-RAR alpha transcripts was useful in monitoring MRD and guiding further treatment to obtain a long remission. Persistently positive transcripts were closely associated with the relapse.

Adolescent↗
PubMed1996

[Folk medicine of the Qiang nationality].

Based on a two-year investigation of folk medicine of the Qiang Nationality, systematic studies have been made on its formation and development, specific methods of physical therapy and experiences and features of clinical application.

China↗
PubMed1996

[Curcuma longa L. tuber yield simulation model and its application under combined agronomic measures for good-quality, high-yield and obvious economic results].

A design of second order orthogonal rotative regression was developed and field tested, and the tuber models for yield, quality and benefit were simulated and built. The effect of agronomic measures on the tuber yield is plant density > phosphorus > sowing date > nitrogen > potassium. There is a clear interrelation effect among agronomic measures. The results of simulation experiment have shown that the optimal combination of farming practices can greatly increase the tuber yield, quality and benefit, and is adjusted according to climate, soil, ferilizer or manure sources, and so on.

Computer Simulation↗
PubMed1996

[Effect of organic fertilizer and mineral fertilizer on the tuber yield of Curcuma longa L].

Regression method of orthogonal conic substitution with factors was employed to build up the tuber models for yield, quality and benefit. Three main measures affecting the tuber yield, quality and benefit were analyzed by these mathematical models. The effect of agronomic measures on the tuber yield is human and livestock excreta, rape cake > Ca3(PO4)2 > KCl. The optimal combination of farming practices has been obtained according to the analysis of these models.

Fertilizers↗
PubMed1996

[Electroanalytical characteristics of ofloxacin in micellar solution].

In a pH 6.30 buffer solution containing 0.001% Tween-80, ofloxacin (OFX) gives a sensitive polarographic wave at -1.46 V (vs SCE), which can be used for the determination of OFX down to 10(-8) mol.L-1. The linear range is from 1.39 x 10(-7) to 1.39 x 10(-5) mol.L-1. The proposed method was applied to determination of OFX in urine and serum samples with relative standard deviation less than 7.0%.

Humans↗
PubMed1995

Cyclic AMP-elevating agents negatively regulate the activation of p72syk in N-formyl-methionyl-leucyl-phenylalanine receptor signaling.

Here we investigated the involvement of the non-receptor protein-tyrosine kinase p72syk in formyl methionyl-leucyl-phenylalanine (fMLP) receptor signaling. The activity of p72syk began to rise from 15 s and reached to maximum within 2-5 min after 5 microM fMLP stimulation in porcine polymorphonuclear neutrophils (PMNs). Cyclic AMP (cAMP)-elevating agents, prostaglandin E2 (PGE2) and forskolin, or dibutyryl cAMP partially suppressed p72syk activities stimulated by fMLP in PMNs. Pretreatment with an inhibitor of cAMP-dependent protein kinase abolished the suppression of the fMLP-induced p72syk activation by these cAMP-elevating agents. It was also observed that cAMP-dependent protein kinase phosphorylates p72syk on serine residues in vitro. These results indicate a possibility that cAMP-dependent protein kinase negatively regulates the activation of p72syk in fMLP-receptor signaling.

Amino Acid Sequence↗
PubMed1995

Rapid construction of integrated maps using inner product mapping: YAC coverage of human chromosome 11.

Inner product mapping (IPM) has been proposed as a hybridization-based method for achieving low-cost, high-throughput, high-resolution radiation hybrid (RH) mapping of clones. Using Alu-PCR products of chromosome 11-specific clones, we serially hybridized a set of RHs against gridded filters of YACs having an average size of 350 kb. We then combined these hybridization data with preexisting RH map data to build an inner product map. This binning of 865 YACs provides the first high-resolution large-scale (> twofold redundancy) clonal coverage of human chromosome 11 and is the first inner product map ever constructed. We verified the accuracy and precision of this chromosome 11 map by performing a novel likelihood analysis on independent YAC hybridization data. These results establish that IPM is a highly rapid, inexpensive, accurate, and precise large-scale long-range mapping method, particularly when preexisting RH maps are available, and that IPM can replace or complement more conventional short-range mapping methods. IPM may enable the rapid construction of sequence-ready maps and the binning of expressed sequences.

Chromosome Mapping↗
PubMed1995

Activation and tyrosine phosphorylation of p72syk as well as calcium mobilization after hydrogen peroxide stimulation in peripheral blood lymphocytes.

To determine the regulatory role of p72syk in lymphocyte activation, peripheral blood lymphocytes were treated with 10 mM hydrogen peroxide. Hydrogen peroxide induced a rapid elevation of p72syk activity (4-6-fold) and a dramatic increase in tyrosine phosphorylation of a number of cellular proteins, including phospholipase C gamma 1 (PLC gamma 1) and p72syk. Monoclonal antibodies to PLC gamma 1 co-precipitated p72syk from hydrogen peroxide-stimulated cell lysates, but not from unstimulated cell lysates. Furthermore, we observed a rise in intracellular Ca2+, corresponding to the combination of extracellular Ca2+ influx and the release from intracellular Ca2+ stores. Extracellular Ca2+ influx was necessary for the sustenance of p72syk activity, but not for the initiation of p72syk activation induced by hydrogen peroxide. Taken together, these data suggested that one possible role of p72syk was to activate PLC gamma 1, at least in part through tyrosine phosphorylation, and then to trigger calcium mobilization in pig peripheral blood lymphocytes in response to hydrogen peroxide stimulation.

Animals↗
PubMed1995

Fibrocartilage associated with human tendons and their pulleys.

The presence of fibrocartilage in tendons that wrap around bony or fibrous pulleys is well known. It is an adaptation to resisting compression or shear, but the extent to which the structure of most human tendons is modified where they contact pulleys is less clear, for there has been no single comprehensive survey of a large number of sites. Less is known of the structure of the corresponding pulleys. In the present study, 38 regions of tendons that wrap around bony pulleys or pass beneath fibrous retinacula have been studied in routine histology sections taken from each of 2 or 3 elderly dissecting room cadavers. Most of the corresponding pulleys have also been examined. Fibrocartilage was present in 22 of the 38 tendon sites and it was most conspicuous where the tendons pressed predominantly against bone rather than retinacula and where they showed a large change in direction. Fibrocartilage was more characteristic of tendons at the ankle than the wrist, probably because the long axis of the foot is at right angles to that of the leg. There was considerable variation in the structure of tendon fibrocartilage. The most fibrocartilaginous tendons had oval or round cells embedded in a highly metachromatic matrix with interwoven or spiralling collagen fibres. At other sites, fibrocartilage cells were arranged in rows between parallel collagen fibres. The differences probably relate to differences in development. A single tendon could be modified at successive points along its length and fibrocartilage could be present in the endotenon and epitenon as well as in the tendon itself. Pathological changes seen in 'wrap around' tendons were fragmentation and partial delamination of the compressed surface, chondrocyte clustering, fatty infiltration and bone formation. Three types of pulleys were described for tendons--bony prominences and grooves, fibrous retinacula and synovial joints. The extent of cartilaginous differentiation on the periosteum of bony pulleys frequently mirrored that in the corresponding tendon. The cartilage or fibrocartilage prevents the tendon from 'sawing' through the bone. Some of the best known retinacula were largely fibrous, though the inferior peroneal retinaculum and the trochlea for the superior oblique were cartilaginous. The results underline the considerable regional heterogeneity in different tendons and their pulleys. They show that one tendon is not like another and that tendons may need to be carefully selected for particular surgical transfers or joint reconstructions.

Aged↗
PubMed1995

[Apolipoprotein (a) polymorphism in relation to coronary heart disease in Chinese Han nationality].

We investigated the association of apolipoprotein (a) [apo(a)]polymorphism with coronary heart disease in Chinese Han nationality. The effects of the apo(a) phenotypes on lipoprotein [Lp (a)], total cholesterol (TC), high density lipoprotein cholesterol (HDL), and triglyceride (TG) levels were also investigated. The CHD group consisted of 105 patients (85 were survivors from previous myocardial infarction and 20 had > or = 75% narrowing in at least one of the major coronary arteries found by coronary angiography). The control group included 102 healthy individuals who had no symptoms and clinical signs of cardiovascular diseases. Apo(a) phenotype was performed by SDS-polyacrylamide gel electrophoresis (PAGE) under reducing conditions followed by immunoblotting. Determination of (a) Lp(a) and other lipoproteins were also performed. The apo(a) low molecular weight phenotypes (B, S1, S2) were more frequent in the CHD patients than in the healthy individuals (30.5% vs 15.7%, P < 0.05). Lp(a) concentrations were significantly higher in the patients than in the controls (257 +/- 225 mg/L vs 145 +/- 157 mg/L, P < 0.001). The results from stepwise logistic regression analysis indicated that apo(a) phenotype was a significant predictor of CHD, independent of TC, LDL-C and HDL-C. But apo(a) molecular weight was inversely related to Lp(a) levels. The apo(a) low molecular weight phenotypes associated with elevated Lp(a) levels was a primary genetic risk factor for CHD in Han Chinese.

Aged↗