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Biomedical subjects

F Wang

Publications and source records attributed to F Wang.

At least 505 records · Page 28Linked to original sources
PubMed1996

[Displaying of infrared thermogram of temperature character on meridians].

In this work we have observed the skin temperature of central line of the back and chest-abdomen on the human body truck by the infrared thermography. Here care the results: (a) Of all the volunteers, 57.1% central lines of the back and 7.7% central lines of the chest-abdomen of the volunteers are the longitudinal high thermal lines in normal state. (b) After moxibustion at Mingmen (GV 4) point, the temperature of 70.4% central lines of the back is going up. After moxibustion at Zhongwan (CV 12) point, the temperature of 56.0% central lines of the chest-abdomen is going up. The high thermal lines are longer and their continuity is hotter after moxibustion. (C) The lines on the back which are about 20 approximately 50 centimetres are longer than those on the chest-abdomen which are about 10-30 centimetres. The results suggest that the high thermal lines are the objective display of the temperature character on the Governor and Conception vessel. The formation of high thermal line may have some relationship with the compact connective tissue or microcirculation.

Acupuncture Points↗
PubMed1996

Serum haptoglobin suppresses T-lymphocyte functions following burns.

It is well known that serum immunosuppressive factors play an important role in the mechanism of postburn immunosuppression. This study was intended to investigate the effect of haptoglobin, purified from the serum of burned patients by affinity chromatography, on the proliferation and interleukin-2 (IL-2) secretion of normal murine thymocytes induced by ConA and the proliferation of IL-2 dependent cell line (CTLL-2) stimulated by recombinant human IL-2, so as to elucidate the role of serum haptoglobin in postburn T-lymphocyte dysfunction. The results showed that purified haptoglobin, at the level equivalent to the concentration found in serum of burned patients, significantly inhibited the proliferation and IL-2 secretion of normal murine thymocytes as well as CTLL-2 proliferation; whereas it exhibited no immunosuppressive effects at the level equivalent to the concentration found in serum of normal volunteers. According to the results reported here, it is suggested that extraordinary increase in serum haptoglobin level may be an important factor of impaired T-lymphocyte responses following burns.

Animals↗
PubMed1996

[Effect of acupuncture on regional cerebral blood flow and cerebral functional activity evaluated with single-photon emission computed tomography].

Observation on effect of acupuncture on regional cerebral blood flow (RCBF) and cerebral functional activity was conducted in 11 healthy volanteers and 9 patients with cerebral vascular disease by using single-photon emission computed tomography. Results showed a significant difference in effect of needle retention and electro-acupuncture stimulation on contralateral cerebral hemisphere cortex and thalamus, ipsilateral basal ganglion and bilateral cerebella, the change on cerebral blood flow induced by electroacupuncture was greater than that induced by the former method. It is speculated that the improvement of cerebral blood supply and stimulation of functional activity of brain nerve cells induced by acupuncture on point of extremities depend on the regulatory function of central nerve system. Stimulations were transmitted in mainly through specific and non-specific sensory afferent systems, also the involvement of extrapyramidal system and cerebellum. Patients with cerebral vascular diseases are more sensitive to electro-acupuncture than healthy subjects.

Acupuncture Therapy↗
PubMed1996

[Pathologic study on heart and lung transplants].

In order to investigate the pathologic features of cardiac and pulmonary allografts, endomyocardial biopsies (EMB) and transbronchial lung biopsies (TBLB) were studied in 3 patients after lung and heart transplantation. 2 autopsy examinations after a cardiac and a combined heart and lung transplantation were included in this study. The results demonstrated that the presence and the severity of allograft rejection were closely related to the degree of interstitial and perivascular lymphocyte infiltration. Parenchymal injuries may sometimes be a concomitant sign. One patients died suddenly 7 months after cardiac transplantation because of acute severe allograft rejection in combination with allograft coronary disease. Another patient who received combined heart and lung transplant died early after the operation due to coronary thromboembolism. The patient who received a single lung transplant has already survived 16 months. TBLB at 11 and 13 months after the operation showed the recurrence of pulmonary sarcoidosis in the donor lung. Our study confirmed that EMB and TBLB provided useful information for acute allograft rejection after heart and lung transplantation.

Adolescent↗
PubMed1996

[Analysis of changes in human embryo fibroblasts with long-term exposure to drinking water in gastric cancer prevalent areas by flow cytometry].

Cell cycle distribution, cell proliferation index (PI) and DNA index (DI) were analyzed with flow cytometry (FCM) to study changes in human embryo fibroblast exposed to drinking water in gastric cancer prevalent areas for a long time. Results showed both proportion of cells in S and G2M phases and PI increased significantly, DI were beyond its normal range, and cells revealed morphologically abnormal. It suggests drinking water in gastric cancer prevalent areas may contain carcinogenic substances, and correlate closely to high incidence of gastric cancer.

Carcinogenicity Tests↗
PubMed1996

[Histochemical study of lectin receptor and cell morphometric analysis on oral leukoplakias, epithelial dysplasia and squamous carcinoma].

The histochemical study of lectin receptor and the cell morphometric analysis were applied to cases to oral mucosal leukoplakias in order to find the differences between abnormal and normal cells in premalignant tissues. Results showed that the cell morphological change and glycosyl change of the cell surface in leukoplakias with severe epithelial dysplasia were similar to those of carcinoma, which suggests that the above methods may be used to differentiate the degree of the epithelial dysplasia of oral mucosal leukoplakias.

Carcinoma, Squamous Cell↗
PubMed1996

Refractive changes in chicks with form-deprivation myopia.

PURPOSE: To study the refractive changes of form deprivation of myopia. METHODS: Haisaik chickens were used to establish the animal models of myopia. Monocular eyelids were sutured for form deprivation on the 5th day after chickens birth. The chickens were examined by optometer and the anteroposterior axis, transverse and vertical diameters were measured by verniermicrometer. RESULTS: Form deprivation leads to myopic refractive abnormality (P < 0.001). The ocular anteroposterior axis (P < 0.005), transverse and vertical diameters lengthen (P < 0.05). CONCLUSION: Form deprivation is the main cause of the development of myopia.

Animals↗
PubMed1996

[Spasmolytic effects of crebanine on isolated gallbladder and Oddi's sphincter in vitro].

The study has shown that the contraction induced by histamine, Ca2+ and K+ in the biliary system of guinea-pigs is antagonized by crebanine in vitro. The antagonism presents a depression of the maximal response of the dose-response curve for the agonists in a non-competitive manner. Crebanine blocks the release of calcium from intracellular storage on isolated gall-bladder. The spontaneous activity of the oddi's sphincter in vitro is inhibited by crebanine. The initial phasic and the ionic contraction induced by K+ (40 mmol/L) in the isolated oddi's sphincters of guinea-pigs are inhibited by crebanine.

Animals↗
PubMed1995

A pregnancy-specific glycoprotein is expressed in the brain and serves as a receptor for mouse hepatitis virus.

Mouse hepatitis virus (MHV), a murine coronavirus known to cause encephalitis and demyelination, uses murine homologues of carcinoembryonic antigens as receptors. However, the expression of these receptors is extremely low in the brain. By low-stringency screening of a mouse brain cDNA library, we have identified a member of the pregnancy-specific glycoprotein (PSG) subgroup of the carcinoembryonic antigen gene family. Unlike other PSG that are expressed in the placenta, it is expressed predominantly in the brain. Transfection of the cDNA into COS-7 cells, which lack a functional MHV receptor, conferred susceptibility to infection by some MHV strains, including A59, MHV-2, and MHV-3, but not JHM. Thus, this is a virus strain-specific receptor. The detection of multiple receptors for MHV suggests the flexibility of this virus in receptor utilization. The identification of this virus in receptor utilization. The identification of a PSG predominantly expressed in the brain also expands the potential functions of these molecules.

Amino Acid Sequence↗
PubMed1995

Platelet factor 3 in plasma fractions: its relation to microparticle size and thromboses.

Platelet factor 3 (PF3) was assayed by Russell's viper venom (RVV) in three plasma fractions, platelet-rich plasma (PRP), platelet poor plasma (PPP), and 0.1 microns particle-filtered plasma (PFP), in 42 healthy controls, 34 patients with recent cerebrovascular accidents (CVA) and 28 with recent ischemic events from coronary artery disease (CAD). Platelet microparticles (PMP) were assayed in PPP by flow cytometry. Relative to controls, the RVV clotting times were shortened in all three plasma fractions in both patient groups, p < 0.001. PMP were also elevated in both patient groups, p < 0.001. Linear regression analysis showed that the RVV times of PPP are inversely correlated with PMP, p < 0.005, in patient groups but not in controls. There was no correlation of RVV time with PT, APTT or FIB. After converting RVV times to units of PF3 activity, it could be shown that only about 1/4 of the total PF3 activity was contributed by platelets. The major contribution to the PF3 activity in controls was from microparticles < 0.1 microns but in patients was due mainly to microparticles > 0.1 microns. The RVV time was superior to routine coagulation tests in discriminating thrombotic patients from healthy controls.

Adolescent↗
PubMed1995

Regulation of the balance of cytokine production and the signal transducer and activator of transcription (STAT) transcription factor activity by cytokines and inflammatory synovial fluids.

The balance between type 1 and 2 T helper cell cytokine production plays an important role in several animal models of autoimmunity, and skewed patterns of cytokine expression have been described in human inflammatory diseases. Many cytokines activate signal transducer and activation of transcription (STAT) transcription factors, which, in turn, activate transcription of inflammatory effector genes. We used mononuclear cell priming cultures and inflammatory synovial fluids (SFs) derived from arthritis patients to examine the regulation of cytokine production and STAT activity by an inflammatory synovial microenvironment. Exposure to SFs during priming resulted in an 81% inhibition of interferon (IFN)-gamma, but not interleukin (IL) 4, production by effector cells generated in priming cultures. SF suppression was mediated by IL-4 and IL-10 and inhibition of IL-12 expression, and it was reversed in a dominant fashion by exogenous IL-12. SFs blocked the sustained activity of transcription factor Stat1, but not Stat3, during the priming period, and Stat1 activity was differentially regulated by cytokines in parallel with their positive or negative regulation of IFN-gamma production. Active Stat3, but not Stat1, was detected in cells from inflamed joints. These results suggest a role for altered balance of Stat1 and Stat3 transcriptional activity in the regulation of T cell differentiation and in the pathogenesis of inflammatory synovitis.

Arthritis, Rheumatoid↗
PubMed1995

Stimulatory antibody-induced activation and selective translocation of protein kinase C isoenzymes in human platelets.

A novel stimulatory monoclonal antibody (Mab) termed Mab.F11 induces granular secretion and subsequent aggregation of human platelets. Mab.F11 recognizes a unique 32 and 35 kDa protein duplex on the platelet membrane surface, called the F11 receptor; binding of Mab.F11 to its receptor results in increased intracellular phosphorylation of P47, the known protein kinase C (PKC) substrate pleckstrin. In order to determine whether the mechanism of action of Mab.F11 involves direct activation of PKC, two types of functional assays for measuring PKC activity were performed. Measurement of PKC activity in digitonin-permeabilized platelets revealed that Mab.F11 produced a rapid, 2-3 fold increase in the control value in the phosphorylation of the PKC peptide substrate, PKC(19-31) Ser25. The increase in PKC activity induced by Mab.F11 was found to be associated with the platelet membrane; a 1.6-fold control value increase in membrane PKC activity occurred rapidly, within 10 s of the addition of Mab.F11. The translocation from the cytoplasm to the membrane induced by Mab.F11 in PKC isoenzymes alpha and zeta was reversible, whereas translocation of the PKC isoenzymes delta, beta, eta' and theta was irreversible, with PKC levels remaining elevated in the membrane for at least 15 min. Taken together, our results demonstrate that in the initial stages of platelet activation by this stimulatory antibody, the enhanced membrane PKC activity reflects the presence of all six isoenzymes. At later stages, PKC activity is reflective of four isoenzymes. These results demonstrate that separate groups of PKC isoenzymes must be involved in different aspects of platelet activation. The long lag period and prolonged activation time of platelets by Mab.F11 renders this agonist most suitable for identifying the isoenzymes and their specific endogenous protein substrates involved in platelet secretion and aggregation induced by platelet membrane protein antibodies.

Amino Acid Sequence↗
PubMed1995

Cell cycle control of c-kit+IL-7R+ B precursor cells by two distinct signals derived from IL-7 receptor and c-kit in a fully defined medium.

An important goal for the investigation of the proliferation of mammalian cells is to establish a fully defined condition for culturing them in vitro. Here, we report establishment of a fully defined culture condition that supports the primary culture of normal c-kit+IL-7 receptor (IL-7R)+ B precursor cells without the aid of stromal cell lines. This defined culture condition contains IL-7, the ligand for c-kit, transferrin, insulin, and bovine serum albumin as protein components. By using the cell lines derived from RAG2(-/-) mice, which do not differentiate into c-kit- stage, we have evaluated the role of each protein in the cell cycle progression of c-kit+IL-7R+ B precursor cells. Since B precursor cells can grow without insulin, c-kit remains a sole functional receptor tyrosine kinase for their growth. While both c-kit ligand (KL) and IL-7 are the requisite molecules for sustained proliferation of B precursor cells, each molecule plays distinct roles. IL-7 starvation results in prompt arrest of the cells at G1. An accumulation of the cells in the mitotic phase was also detected. Thus, the major role of IL-7 is to regulate the G1/S transition and the process of cytokinesis of B precursor cells. Although prolonged KL starvation over 48 h resulted in accumulation of G1 cells, its effect could not be detected within 24 h, which is long enough for all the cells to complete one cell cycle. This suggests that KL might be involved in the cell cycle progression of B precursor cells in a manner that its signal could still be effective in the one or two cell cycles that follow. Although molecular nature of the signals underlying the present observation awaits future investigation, the method described in this report would provide a useful model system for investigating the signaling pathways that are involved in the cell cycle progression of B precursor cells.

Animals↗
PubMed1995

Desmopressin (DDAVP) acts on platelets to generate platelet microparticles and enhanced procoagulant activity.

Desmopressin (DDAVP), an analog of vasopressin (AVP), has wide clinical application as an anti-hemorrhagic (AH) agent. DDAVP in vivo releases vWF from endothelial cells but is reported to have little action on platelets. However, DDAVP is often used to improve hemostasis in platelet dysfunctions. We examined the effect of DDAVP on platelet microparticle (PMP) formation and procoagulant activity in vitro using platelets from normal volunteers and in vivo in six patients receiving DDAVP therapy. In the former, platelets were incubated with DDAVP (0.5 to 25 nM) and PMP released were stained with FITC-labeled MAb alpha-GP IIb/IIIa for flow cytometry. Procoagulant activity was measured in a clot-based assay using Russel's viper venom (RVV) calibrated with cephalin. A mean increase of 2-3 fold was observed in both PMP and procoagulant activity. Parallel to these observations was a dose-dependent rise in organelle-associated Ca2+. The assays were also performed on six patients prior to and at one hour after infusion of DDAVP, and similar but lesser effects were observed. We conclude that DDAVP acts on platelets in vitro, and that these effects may contribute to the hemostatic action of DDAVP in platelet dysfunctions in vivo.

Adult↗
PubMed1995

Generation and assembly of secretory antibodies in plants.

Four transgenic Nicotiana tabacum plants were generated that expressed a murine monoclonal antibody kappa chain, a hybrid immunoglobulin A-G heavy chain, a murine joining chain, and a rabbit secretory component, respectively. Successive sexual crosses between these plants and filial recombinants resulted in plants that expressed all four protein chains simultaneously. These chains were assembled into a functional, high molecular weight secretory immunoglobulin that recognized the native streptococcal antigen I/II cell surface adhesion molecule. In plants, single cells are able to assemble secretory antibodies, whereas two different cell types are required in mammals. Transgenic plants may be suitable for large-scale production of recombinant secretory immunoglobulin A for passive mucosal immunotherapy. Plant cells also possess the requisite mechanisms for assembly and expression of other complex recombinant protein molecules.

Amino Acid Sequence↗
PubMed1995

Ligand-specific structural domains in the fibroblast growth factor receptor.

Two tandem immunoglobulin-like disulfide loops (Loops II and III) linked by a short connecting sequence in the ectodomain of the fibroblast growth factor receptor kinase compose the binding sites for glycosaminoglycan and fibroblast growth factor (FGF) ligands. Alternate splicing of exons IIIb and IIIc coding for the COOH-terminal half of Loop III confers high affinity for FGF-7 or FGF-2, respectively, on the fibroblast growth factor receptor ectodomain without effect on the binding of FGF-1. Here we show that a 139-amino acid fragment composed of Loop II, the inter-Loop II/III sequence, and a short segment of the NH2 terminus of Loop III is sufficient and near the minimal requirement for binding of FGF-1, FGF-2, and FGF-7. Extension of the fragment by five additional highly conserved residues (SD(P/A)QP) within a distinct constitutive structural domain (fl1) in Loop III restricts the binding of FGF-7 without effect on FGF-1 and FGF-2. Since the presence of exon IIIc in the full-length ectodomain does not change this ligand binding profile, we suggest that alternately spliced exon IIIc plays no active role in binding of the three ligands. In contrast, exon IIIb actively abrogates the restriction on the binding of FGF-7 and concurrently lowers the affinity for FGF-2.

Alternative Splicing↗