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Biomedical subjects

H Zeng

Publications and source records attributed to H Zeng.

At least 109 records · Page 6Linked to original sources
PubMed1999

Evaluation of cardiac beta-adrenergic receptor function in children by dobutamine stress echocardiography.

OBJECTIVE: To investigate the role of dobutamine stress echocardiography in evaluating cardiac beta-adrenergic receptor (beta-AR) function and responsiveness in children. METHODS: Left ventricular ejection fraction (EF), fractional shortening (FS), left ventricular end systolic volume index (ESVI), the ratio of systolic blood pressure and ESVI (SP/ESVI) were measured by dobutamine stress echocardiography (DSE) in 30 children with beta-AR hypersensitivity, 15 children with dilated cardiomyopathy and 30 normal children respectively. RESULTS: Before pharmacological stress, EF and FS were 0.72 and 0.39 respectively in beta-AR hypersensitivity group versus 0.70 and 0.35 respectively in control group. There was no difference of the indices between the two groups (P > 0.05). SP/ESVI was 0.76, higher than the value of 0.66 in control group (P < 0.05); EF, FS and SP/ESVI were 0.41, 0.15 and 0.10 respectively, which were significantly lower than those in control group. After dobutamine stress of 5 micrograms.kg-1.min-1 and 10 micrograms.kg-1.min-1, EF, FS and SP/ESVI were significantly increased in patients with beta-AR hypersensitivity and there were no changes in children with dilated cardiomyopathy compared with values of baseline. CONCLUSION: Cardiac beta-AR function and responsiveness can be evaluated by dobutamine stress echocardiography.

Adolescent↗
PubMed1999

[Cloning of a new cDNA: responded to all-trans retinoic acid in HL-60 cell differentiation].

In this paper a new type of cDNA fragment named as W-1 gene was first cloned and sequenced from ATRA induced HL-60 cells by using differential display PCR (DD-PCR) and DNA sequencing techniques. These differentially expressing products of the gene responding to ATRA were further confirmed by Northern blotting analysis. The results showed that the expressing level of this gene induced by ATRA (10(-6) mol.L-1) for 16 hrs was much higher than that in the control HL-60 cells, but its expression in HL-60 was reduced to an unestimable level after induction of ATRA (10(-6) mol.L-1) for 24 hrs. It suggests that ATRA may increase the expression of W-1 gene during the early stage of HL-60 cell differentiation. The exact mechanism of action is being studied further.

Antineoplastic Agents↗
PubMed1999

[Taxonomy of the producing strain of agricultural antibiotic 2-16].

In screening process of new agricultural, a streptomycetes, 2-16, was isolated from the soil sample collected in Huangsan. The secondary metabolites produced by the strain had strong inhibition to Sclerotinia sclerotiorum. By identification, this strain was regarded as new variety of Streptomyces ahygroscopicus and was called Streptomyces ahygroscopicus var. huangsanensis.

Agrochemicals↗
PubMed1999

[To evaluate the examinations both colour Doppler flow image and CT for orbital pseudotumors].

PURPOSE: To explore the values of colour doppler flow image(CDFI) technique and computer tomographic(CT) scan in diagnosising orbital pseudotumors. METHODS: CDFI and CT were used for examining 67 cases of orbital pseudotumors demonstrated with surgery and pathaology. The results were treated with self-match design Chi-square test. RESULTS: The diagnosis validities for 29 mass-type cases with CDFI and CT were 44.8% and 82.8%, respectively, with significant difference (chi 2 = 5.88, P < 0.05). The validities for 25 diffuse-type cases were 84.0% and 56.0%, respectively, with significant difference. (chi 2 = 4.0, P < 0.05). The validities for 19 mixture-type cases were 63.2% and 78.9%, respectively, with no significant difference (chi 2 = 1.63, P > 0.05). The diagnosis validities for all 67 cases were 63.0% and 72.7%, respectively, with no significant difference (chi 2 = 1.16, P > 0.05). CONCLUSION: The diagnosis validities with both imaging methods were not different for diagnosis of orbital pseudotumors. But the values for diagnosing various pseudotumors were different. The validity with CDFI was superior to CT in diffuse type; CT was superior to CDFI in mass type; while the validity with CDFI and CT were not significant different in mixture type.

Adolescent↗
PubMed1998

[Effect of allicin on ethanol-induced hepatotoxicity in mice].

To study the effect of allicin, an effective component of garlic, on ethanol-induced hepatotoxicity in mice. The results showed that allicin (10 mg/kg ig, qd x 10) could reverse the higher activities of serum ALT and glutathione s-transferase (GST) in ethanol-treated mice. Furthermore, allicin could significantly enhance the content of hepatic reduced glutathione (GSH), and the activities of hepatic glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Re) and GST in ethanol-induced hepatotoxicity mice. There were no remarkable changes in the hepatic catalase (Cat) and superoxide dismutase(SOD) activities. These results suggested that allicin have the effective hepato-protection on ethanol-induced hepatotoxicity, which is related to its selective effect on the glutathione-related enzyme system.

Animals↗
PubMed1998

A role for persisting antigen, antigen presentation, and ICAM-1 in increased renal graft survival after oral or portal vein donor-specific immunization.

BACKGROUND: We studied the mechanism behind increased renal allotransplant survival when C3H mice received donor-specific portal vein or oral immunization with C57BL/6 cells. Both regimens lead to donor-specific increased graft survival, in association with decreased production of cytotoxic T lymphocytes and altered cytokine production from host lymphocytes (decreased interleukin [IL]-2 production; increased IL-4, IL-10, and transforming growth factor-beta). METHODS: We examined a role for persistent donor-derived antigen, in association with host dendritic cells, as well as a role for intercellular adhesion molecule-1 (ICAM-1), in the maintenance of unresponsiveness in host C3H spleen cells to donor antigen. We investigated whether there was a cooperative interaction between donor dendritic cells (DC) and host hepatic mononuclear cells in the induction of immunoregulation in C3H cells. RESULTS: In mice with surviving renal grafts, donor antigen, in association with host DC, induced the recall of cytotoxicity from C57BL/6 immune C3H spleen cells and IL-4 but not IL-2 production, despite the decreased cytotoxicity seen in the renal transplant recipients themselves. Fresh donor DC induced IL-2 but not IL-4 production. Blocking expression of ICAM-1 on donor grafts, either with anti-ICAM-1 monoclonal antibodies after renal grafting or using grafts from ICAM-1 "knockout" mice, led to further increased survival. Cultured C3H responder spleen cells, incubated with C57BL/6 DC and C3H hepatic cells, transferred hyporesponsiveness to C57BL/6 cells in vitro and in vivo (as assayed by survival of C57BL/6 renal allografts). CONCLUSIONS: Our data suggest a role for ICAM-1, persistent donor antigen (on host DC), and accessory hepatic monocytes in the induction and maintenance of tolerance after portal vein immunization.

Administration, Oral↗
PubMed1998

Cloning and characterization of a novel binding factor (GMEB-2) of the glucocorticoid modulatory element.

The 21-base pair glucocorticoid modulatory element (GME) of the rat tyrosine aminotransferase gene is the only cis-acting element known to modulate the transcriptional activity of receptors bound to glucocorticoid response elements. Specifically, the GME increases the activity of complexes bound both by physiological concentrations of glucocorticoids, due to a left shift in the dose-response curve, and by saturating concentrations of anti-glucocorticoids. For this reason, the nuclear protein(s) that has been demonstrated to bind to the GME is of major interest as a possible transcription factor with hitherto undescribed properties. Subsequent studies indicated that not one but two proteins of 88 and 67 kDa (= GMEB-1 and -2, respectively) formed a heteromeric complex with double-stranded GME oligonucleotides in gel shift assays and participated in the expression of GME activity (Oshima, H., Szapary, D., and Simons, S. S., Jr. (1995) J. Biol. Chem. 270, 21893-21910). Here, we report the use of polymerase chain reaction of degenerate oligonucleotides and 5'- and 3'-rapid amplification of cDNA ends to clone two cDNAs of 2. 0 and 1.9 kilobase pairs that probably result from alternative splicing. Both cDNAs encoded open reading frames containing all four previously sequenced peptides. The longer 2.0-kilobase pair cDNA encoded an open reading frame for an acidic, 529-amino acid protein and afforded a major 67-kDa and a minor 58-kDa protein after in vitro transcription/translation. Both proteins were recognized by a mono-epitopic antibody raised against a peptide of GMEB-2. The in vitro translated protein bound to GME DNA in gel shift assays. However, the binding to GME DNA increased markedly after mixing with authentic GMEB-1 to give a gel-shifted complex that was similar to that derived from HTC cell cytosol. GMEB-2 shares a unique domain (KDWKR) with proteins derived from diverse organisms as follows: Drosophila (DEAF-I), rat (Suppressin), and Caenorhabditis elegans (three unknown open reading frames). Collectively, these data suggest that the 67-kDa GMEB-2 not only is an important factor for the modulation of glucocorticoid receptor bound to glucocorticoid response elements but also may belong to a novel family of transcription factors.

Amino Acid Sequence↗
PubMed1998

Increased expression of the novel molecule OX-2 is involved in prolongation of murine renal allograft survival.

BACKGROUND: Portal venous (p.v.) peritransplant immunization with dendritic cells from bone marrow cultures, along with cyclosporine (10 mg/kg), produces antigen-specific increased renal allograft survival compared with recipients receiving intravenous (i.v.) immunization. Increased survival is associated with altered cytokine production from recipient T cells restimulated with donor antigen. We used a suppressive subtractive hybridization approach to explore a role in the regulation of transplant rejection for other genes differentially expressed after p.v. immunization. METHODS: Subtractive hybridization was performed using tissue from p.v. and i.v. immunized mice and a novel polymerase chain reaction-based approach. A gene-bank search was used to identify the source of the differentially expressed cDNAs. One product, the mouse homologue of rat OX-2, was further analyzed using Western gels and FACS analysis of dendritic cells (NLDC145+) isolated from p.v.-immunized mice. RESULTS: Eighty cDNA clones were obtained by suppressive subtractive hybridization. Differential expression was confirmed in Northern RNA blots. One clone showed sequence homology to a gene encoding a molecule on rat dendritic cells (MRC OX-2), with homology to genes encoding the costimulatory molecules CD80 (B7-1) and CD86 (B7-2). In p.v.-immunized mice, a monoclonal antibody to the rat OX-2 molecule identified, by Western blot analysis, increased expression of a molecule with molecular weight (43 kDa) analogous to rat MRC-OX-2; labels (by FACS analysis) indentified increased numbers of a population of cells staining with NLDC145; and blocks indentified increased graft survival. CONCLUSION: Our data suggest that OX-2 is functionally important in the increased graft survival seen in p.v.-immunized mice receiving renal allografts.

Animals↗
PubMed1998

Sjögren's autoimmunity: how perturbation of recognition in endomembrane traffic may provoke pathological recognition at the cell surface.

CD4 T cell antigen recognition requires presentation by major histocompatibility complex Class II molecules (MHC II). B cell surface immunoglobulins recognize antigens independently of MHC II, but activation typically requires CD4 cell cytokines as accessory signals. Plasma membrane-endomembrane traffic in lacrimal gland acinar cells, targets of autoimmune activity in Sjögren's syndrome, may satisfy both requirements. The Golgi protein galactosyltransferase and the lysosomal proteins cathepsin B and cathepsin D appear at the plasma membranes during sustained secretomotor stimulation. The RNA transcription termination factor La, a frequent target of Sjögren's autoantibodies, appears in the acinar cell cytoplasm and plasma membranes during viral infection and during in vitro exposure to cytokines. MHC II cycle through endomembrane compartments which contain La, galactosyltransferase, cathepsin B and cathepsin D and which are sites of proteolysis. This traffic may permit trilateral interactions in which B cells recognize autoantigens at the surface membranes, CD4 T cells recognize peptides presented by MHC II, B cells provide accessory signals to CD4 T cells, and CD4 T cells provide cytokines that activate B cells. Acinar cells stimulate lymphocyte proliferation in autologous mixed cell reactions, confirming that they are capable of provoking autoimmune responses.

Animals↗
PubMed1998

Biodegradation of tricalcium phosphate ceramics by osteoclasts.

Biodegradation of tricalcium phosphate (TCP) ceramics was observed through mixed culture of osteoclasts and TCP discs in vitro in this study. Osteoclasts were isolated from newborn SD rat's marrow of long bone and cultured on TCP discs. The culture terminated at the 48th h and 96th h respectively. Under an inverted microscope, the osteoclasts imparted round or oval body with multinuclear and many thin processes. These cells were positively stained for tartrate-resistance acid phosphatase (TRAP). Scanning electron microscope showed that many resorption lacunae on TCP disc surface and their diameters were smaller than 20 microns. Osteoclasts were located in the lacunae. At the 96th h, the resorption lacunae become larger and osteoclasts showed degeneration. It is suggested that osteoclasts possess ability to re-absorb TCP ceramics under in vitro culturing condition.

Animals↗
PubMed1998

TCR diversity in gammadeltaTCR+ hybridomas derived from mice given portal vein donor-specific pre-immunization and skin allografts.

Portal venous (p.v.) immunization with multiple minor histoincompatible cells leads to antigen-specific increased skin allograft survival. GammadeltaTCR+ hybridoma cells, prepared from mesenteric lymphocytes of p.v. immunized animals, can adoptively transfer this increased graft survival to naive animals. We have analyzed VgammaVdelta gene usage, and TCR gamma-chain junctional diversity in gammadeltaTCR+ hybridomas from mice immunized with different antigen combinations by p.v. or conventional lateral tail vein (i.v.) immunization. Following p.v. immunization two independent sets of hybridoma cells were derived, one expressing a common gamma-chain junctional sequence which was also found in > 85% of the hybridomas derived following i.v. immunization, while the other set showed remarkable gamma-chain junctional sequence diversity. The diversity seen in these latter hybridomas was associated with the antigen specificity of the hybridoma cells. Cells expressing these 'unique' TCR junctional sequences were stimulated to produce cytokines both by hsp and by minor-histocompatibility-specific irradiated peritoneal cells. Cells expressing TCR with a common gamma-chain junctional sequence were stimulated to cytokine production by MHC-matched but minor-histocompatibility mismatched (as well as matched) peritoneal cells, but not by hsp. We suggest that p.v. immunization results in stimulation of both antigen-specific and non-specific regulatory gammadeltaTCR+ cells, which can be distinguished by gamma-chain TCR sequence diversity.

Adoptive Transfer↗
PubMed1998

Analysis of cytokine production and V beta T-cell receptor subsets in irradiated recipients receiving portal or peripheral venous reconstitution with allogeneic bone marrow cells, with or without additional anti-cytokine monoclonal antibodies.

Irradiated (800 rads) AKR mice received intravenous (i.v.) reconstitution with a mixture of B10.BR T-depleted bone marrow cells and spleen cells. Only in groups of mice treated additionally with i.v. cyclophosphamide (Cy; 150 mg/kg), 24 hr before transplantation, was long-term (> 60% at 50 days) survival seen. In mice receiving only irradiation all animals died by 30 days post-transplantation. Histological changes consistent with graft-versus-host disease (GVHD) were seen in the liver of reconstituted mice at 30 days, along with an organ-specific increase in V beta 3 T-cell receptor-positive (TCR+) cells. No such increase in V beta 3 TCR+ cells was seen in the spleen from the same mice. These data are consistent with a tissue antigen-driven expansion of V beta 3 TCR+ cells associated with GVHD in the liver in this model. When we analysed cytokine production in vitro from CD3+ cells restimulated with 'host' (AKR) antigen-presenting cells (APC), we found a transition in cytokine production from preferential synthesis of type-1 cytokines [interleukin-2 (IL-2) and interferon-gamma (IFN-gamma)] at early times (day 15) post-reconstitution to increased production of type-2 cytokines [IL-4, transforming growth factor-beta (TGF-beta) and IL-10] at later times (day 30) post-reconstitution in Cy-treated recipients. Animals not receiving Cy did not show this 'switch' in cytokine production at later time points. We have observed a similar polarization in cytokine production, along with increased graft survival, in recipients of vascularized and non-vascularized allografts after portal venous (p.v.), but not i.v., pretransplant donor-specific immunization. We next studied AKR mice receiving 800 rads and subsequently reconstituted with B10.BR stem cells via the p.v. route. Again these mice showed prolonged survival (> 50% at 50 days), with polarization to IL-4, IL-10 and TGF-beta on restimulation of CD3+ cells in vitro at 30 days post-transplant and increased V beta 3 TCR+ cells in the liver. Infusion of anti-IL-12 monoclonal antibodies into irradiated mice receiving i.v. cell reconstitution produced a similar pattern of changes to those seen after p.v. reconstitution, while a combination of anti-IL-10 and anti-TGF-beta monoclonal antibodies reversed the changes seen after p.v. reconstitution. These data are consistent with an important role for differential cytokine production in the regulation of GVHD following allogeneic bone marrow transplantation.

Animals↗
PubMed1998

Psoriatic plaques exhibit red autofluorescence that is due to protoporphyrin IX.

In evaluating the autofluorescence properties of normal and diseased skin we discovered that psoriatic plaques can emit a distinct red fluorescence when illuminated with UVA or blue light. Using a macrospectrofluorometer equipped with a 442 nm excitation laser, a sharp in vivo fluorescence emission peak around 635 nm could be demonstrated within the plaques of 34 of 75 (45%) patients with psoriasis. This peak was absent from normal appearing skin of psoriatic patients and also from the skin of 66 patients with other dermatologic diseases. A microspectrofluorometer coupled with the same excitation laser was used to obtain emission spectra of separated epidermal sheets and dermis from plaques demonstrating macroscopic red autofluorescence. An emission peak around 635 nm was observed in all three patients thus studied, but only on spectra obtained from the epidermis. Additional spectra of vertical microscopic sections of intact psoriatic skin from five other patients revealed that the peak originated from the stratum corneum. Emission spectra from other microlocations including the mid-epidermis and dermis of psoriatic and normal skin, as well as the stratum corneum of normal skin, failed to demonstrate a 635 nm peak. The excitation and emission fluorescence spectra of acid extracts of psoriatic scale from five patients were all similar to those of protoporphyrin IX in acid solution. High performance liquid chromatography identified the presence of protoporphyrin IX in the acid extracts from psoriatic scale of the same patients. We conclude that native psoriatic plaques can exhibit red autofluorescence that is due to elevated levels of protoporphyrin IX within scales.

Fluorescence↗
PubMed1998

Low ubiquinone content in Escherichia coli causes thiol hypersensitivity.

Thiol hypersensitivity in a mutant of Escherichia coli (IS16) was reversed by complementation with a plasmid that carried the ubiX gene. The mutant had low ubiquinone content. Complementation elevated the ubiquinone level and eliminated thiol hypersensitivity. Analysis of chromosomal ubiX genes indicated that both parent and mutant strains were ubiX mutants. The low ubiquinone content of IS16 was possibly caused by a ubiD ubiX genotype. A ubiA mutant also exhibited thiol hypersensitivity. Neither IS16 nor the ubiA mutant strain could produce alkaline phosphatase (in contrast to their parent strains) after 2 h of induction, thus showing Dsb- phenotypes. The phenomena of thiol hypersensitivity and low ubiquinone content may be linked by their connections to the periplasmic disulfide bond redox machinery.

Amino Acid Sequence↗
PubMed1998

Synergetic protective effects of combined blockade by two kinds of autolesion mediator receptor on neurological function after cervical cord injury.

OBJECTIVE: To investigate the effects of combined blockade by platelet activating factor (PAF) receptor antagonist BN52021 in combination with opiate receptor antagonist naloxone on neurological function and neurological tissue damage after cervical cord injury. METHODS: Spinal cord contusion at C6 segment was made with Allen method in cats, which were randomly divided into four groups: saline control group; BN52021 group; naloxone group; and combined treatment group with BN52021 and naloxone. Alteration of cervical cord blood flow, blood barrier permeability of the spinal cord, cervical cord tissue pathology and neurological functional scores were studied after experimental cervical cord injury. RESULTS: The animals treated with BN52021 or naloxone had significantly better functional scores than saline controls 6 weeks after injury (P < 0.05). Moreover, the combined treatment showed significantly better neurologic recovery than either naloxone or BN52021 treated animals (P < 0.05). The other indexes in combined treatment animals were also superior to those in naloxone or BN52021 treated animals. CONCLUSIONS: Combined blockade by two kinds of autolesion mediator receptor can more effectively inhibit secondary damage production and development after cervical cord injury and improve neurologic function.

Animals↗
PubMed1998

[Expression and significance of interleukin 6, interleukin 8 and their receptors in acute promyelocytic leukemia during all-trans retinoic acid induction treatment].

OBJECTIVE: To evaluate the expression and clinical significance of interleukin 6, soluble glycoprotein 130 (sgp 130), interleukin 8 and type A interleukin 8 receptor (IL-8RA) in acute promyelocytic leukemia (APL) patients during all-trans retinoic acid (ATRA) treatment. METHODS: Serum and bone marrow mononuclear cell (MNC) culture supernatant IL-6, sgp 130, IL-8 concentrations of 18 cases APL patients were measured (ELISA). Bone marrow MNC IL-8RA was measured by flow cytometry after cultured with ATRA (10(-6) mmol/L). RESULTS: Serum IL-6, sgp130, IL-8 levels were higher than normal (P < 0.05), IL-6, sgp130 levels correlated with white blood cell (WBC) counts (P < 0.05) while IL-8 level correlated with body temperature (P < 0.05) at initial diagnosis after 72-hour incubation with ATRA, concentration of IL-6 of bone marrow MNC culture supenatant did not change, that of sgp130 mildly decreased, and IL-8 significantly decreased while the positive rate of IL-8RA on bone marrow MNC increased. During ATRA treatment, serum IL-6 changes were correlated with WBC changes. Peak level of IL-6 and WBC was lower in patients received intermittent therapy than continuous therapy. Serum IL-6 and IL-8 increased when complicated with infection and increase in IL-8 seemed more sensitive. CONCLUSION: Serum levels of IL-6, sgp130, IL-8 may reflect patient's responsiveness to ATRA treatment, predict hyperleukocytosis and intercurrent infection. ATRA induces APL cell differentiation possibly via gp130 signal transduction.

Adolescent↗