PubMed Health⌕ Search

Biomedical subjects

Z C Yang

Publications and source records attributed to Z C Yang.

At least 19 recordsLinked to original sources
PubMed2001

[Changes of serum soluble tumor necrosis factor receptor I in patients with rheumatic fever].

OBJECTIVE: To study the changes and the effects of soluble tumor necrosis factor receptor I (sT-NFR I) in patients with rheumatic fever, and to find out the laboratorial marker of clinic activity in patients with rheumatic fever. METHODS: The serum concentrations of sTNFR I in 16 patients with ARF, 16 patients with chronic inactive rheumatic heart disease (CRHD) and 15 healthy controls were measured by methods of ELISA and the relationship between sTNFR I and ESR or CRP were studied. RESULTS: The sTNFR I serum concentrations in patients with ARF (3.92 +/- 1.28) ng.ml-1 were significantly higher than those with CRHD (1.43 +/- 0.66) ng.ml-1 and healthy controls (1.06 +/- 0.42) ng.ml-1 (all P < 0.01). The serum concentrations of sTNFR I in patients with CRHD were almost the same with those in healthy controls (P > 0.05); Their positive correlation was significantly observed between sTNFR I and CRP(P < 0.001), and wasn't observed between sTNFR I and ESR. CONCLUSION: The Patients with ARF have high serum levels of sTNFR I. It may be used as the laboratorial marker in the clinic assessment of activity in patients with rheumatic fever.

Adolescent↗
PubMed2001

[Modification of membrane lipid of human umbilical vein endothelia cells after direct lipopolysaccharide injury].

Our previous study showed that the membrane viscosity of human umbilical vein endothelial cells (HUVECs) increased with lipopolysaccharide (LPS) concentration after direct LPS damaging, implying that LPS could change the membrane structure and composition of HUVECs. The purpose of the present study was to investigate the modification of HUVECs membrane lipid by LPS under direct LPS injury to HUVECs. Phospholipid components of HUVEC membrane were determined with high performance capillary electrophoresis (HPCE), and HUVECs were directly damaged by LPS of different concentrations: 0, 0.313, 0.625, 1.25, 2.5, 5 and 10 microgram/ml for 3 h, and by 0.625 microgram/ml for 1, 3, 6, 12, 24 and 48 h. The results show that total phospholipid content of HUVECs increased with the increase of LPS concentration at 3 h, and decreased with the duration of LPS effect at 0.625 microgram/ml. Phosphatidylinositol (PI) and phosphatidylcholine (PC) contents increased with the increase of LPS concentration and decreased with the duration of LPS effect; LPS contents and its effect duration had slight effect on sphingomyelin (SM), phosphatidylethanolamine (PE) or phosphatidylserine (PS) contents. The LPS activating effect of HUVEC membrane lipid showed a typical property of enzymatic dynamics. These experimental results indicate that LPS directly activates the metabolism of HUVEC membrane lipid and induces the modification of HUVEC membrane phospholipid, which implies that the mechanism of the impairment of HUVECs by LPS may be related to the membrane structure of HUVECs and the metabolism of HUVEC membrane lipid.

Cells, Cultured↗
PubMed2000

[A new signal receptor family--a review of the current progress of Toll/IL-1R family].

Toll receptor was first identified in studies of dorsalventral polarity formation of drosophila embryo. As its similarity in structure, function and signal transduction pathway to the IL-1 receptor, Toll becomes a member of a new signal receptor family--the Toll/IL-1R family. Besides participating in embryonic development, this signal receptor family also plays a key role in triggering innate defenses against pathogens, in which the function of human Toll protein in the pathogenesis of LPS is especially interested.

Amino Acid Sequence↗
PubMed1999

Reptilian chemistry: characterization of dianeackerone, a secretory product from a crocodile.

The major volatile component in the paracloacal glandular secretion of the adult African dwarf crocodile (Osteolaemus tetraspis) was isolated and characterized as a 19-carbon aromatic ketone, dianeackerone (3,7-diethyl-9-phenyl-2-nonanone). This ketone is absent from the secretion of immatures. Careful examination of dianeackerone samples isolated from individual adults revealed that this ketone occurs as both the (3S, 7S) and (3S, 7R) stereoisomers, with different individuals presenting strikingly different ratios of the isomeric forms. Our initial suspicion that the stereoisomeric dianeackerones might be indicators of gender proved untenable, leaving the role of these glandular constituents a challenge for future study.

Alligators and Crocodiles↗
PubMed1999

Improvement of early postburn cardiac function by use of Panax notoginseng and immediate total eschar excision in one operation.

Cardiac dysfunction development in the early stage postburn has been an important problem in burn treatment. However, no effective therapies are available for use in clinical practice. In this study, we sought to determine whether early total eschar excision (EEE) in one operation and the traditional Chinese herb Panax notoginseng (PNS) would be helpful in improving early postburn cardiac function. 160 Wistar rats were randomly divided into burn (burn group, n = 50), burn treated with EEE (EEE group, n = 50), burn treated with PNS (PNS group, n = 50) groups and normal controls (n = 10). All rats except the normal control were given a 30% TBSA full skin thickness burn and resuscitated with Ringer's lactate. EEE was performed immediately after the burn group received the first intraperitoneal injection of Ringer's lactate. The wound was covered with homoskin from normal rats. In the PNS group, two doses of PNS (200 mg/kg for each dose) were given intraperitoneally immediately and 4 h postburn. Cardiac contractile function and cardiac troponin T (TnT) were determined at 1, 3, 6, 12 and 24 h postburn. Results showed that cardiac contractile parameters including AOSP, AODP, LVSP and +dp/dt(max) all declined and were still significantly lower than the control values at 24 h postburn. Cardiac TnT was elevated markedly and reached a level 25 times higher than control at 12 h postburn. In EEE and PNS groups, the reduction of cardiac contractile function was limited as compared with that in the burn group. Levels of TnT in both EEE and PNS groups were significantly lower than in the burn group 6 h postburn later. The findings of this study demonstrated that both EEE and PNS were effective in improving early postburn cardiac function.

Animals↗
PubMed1999

Pathogenesis of early cardiac myocyte damage after severe burns.

BACKGROUND: The importance of early cardiac myocyte damage during postburn trauma has been emphasized in recent years. However, its pathogenesis, prevention, and treatment have not been fully clarified. The aim of this study is to define its pathogenesis. METHODS: Rats with 30% third-degree burns were used. Cardiac biochemical markers reflecting cardiac myocyte damage including troponin T, cardiac myosin light chain 1, creatinine kinase and its cardiac-specific isoenzyme compound, as well as inflammatory mediators such as tumor necrosis factor, endothelin/nitric oxide ratio, malondialdehyde, and superoxide dismutase, were determined. RESULTS: Cardiac biochemical markers reflecting cardiac myocyte damage, including troponin T, cardiac myosin light chain 1, cardiac-specific isoenzyme compound, were all significantly elevated between 3 hours and 24 hours after burn. Changes in tumor necrosis factor, endothelin/nitric oxide ratio, and malondialdehyde were similar to those of cardiac biochemical markers. In contrast, levels of superoxide dismutase declined markedly after burn. CONCLUSION: The findings of this study showed that considerable amounts of myocardial constructive protein degradation and release due to destruction of cardiac myocytes occurred early after severe burns. The inflammatory mediators released after burn injury may be involved in the pathogenesis of myocardial destruction.

Animals↗
PubMed1998

Mirasorvone: a masked 20-ketopregnane from the defensive secretion of a diving beetle (Thermonectus marmoratus).

The sunburst diving beetle, Thermonectus marmoratus, ejects a milky fluid from its prothoracic defensive glands when disturbed. Two major volatile components of this secretion are steroids; cybisterone (structure 7) constitutes about 20% of the volatiles, and a new steroid, mirasorvone, about 50%. Mirasorvone is assigned an 18-oxygenated pregnane structure (structure 9) on the basis of extensive spectroscopic data. Although no 18-oxygenated steroid has been described previously from an insect source, a closely related hormone with mineralocorticoid activity, 18-hydroxydeoxycorticosterone (structure 13), has been isolated from the adrenal glands of rats.

Animals↗
PubMed1998

Serial experimental and clinical studies on the pathogenesis of multiple organ dysfunction syndrome (MODS) in severe burns.

These serial clinical and experimental studies were designed to clarify the pathogenesis of postburn MODS. Both animal and clinical studies were performed. In animal experiments, 46 male cross-bred dogs were cannulated with Swan-Ganz catheters and 39 of them were inflicted with 50% TBSA third degree burns (7 were used as controls). The burned dogs were randomly divided into 4 groups: immediate infusion, delayed infusion, delayed fast infusion and delayed fast infusion combined with ginsenosides. All dogs were kept under constant barbiturate sedation during the whole study period. Hemodynamics, visceral MDA, mitochondrial respiratory control rate (RCR) and ADP/O ratio, ATP, succinic dehydrogenase (SDH), organ water content as well as light and electron microscopy of visceral tissues were determined. In the clinical study, 61 patients with extensive deep burns were chosen, of which 16 sustained MODS. Plasma TXB2/6-keto-PGF1alpha ratio, TNF, SOD, MDA, circulatory platelet aggregate ratio (CPAR), PGE2, interleukin-1, total organ water content and pathological observations of visceral tissues from patients who died of MODS were carried out. Results demonstrated that ischemic-reperfusion damage due to severe shock, sepsis and inhalation injury are three main causes of postburn death. All inflammatory mediators increased markedly in both animals and patients who sustained organ damage or MODS. SDH, RCR, ADP/O and ATP decreased significantly. These findings suggested that ischemic damage and systemic inflammatory response syndrome (SIRS) initiated by mediators or cytokines might be important in the pathogenesis of postburn MODS.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

N-Glycosylation of pig flavin-containing monooxygenase form 1: determination of the site of protein modification by mass spectrometry.

By using a combination of biochemical methods (i.e., endoglycosidase H digestion and immunoblot and plant lectin binding studies), it was verified that pig flavin-containing monooxygenase (FMO1) was N-glycosylated. By using mass spectrometry approaches [i.e., peptide mapping, gas chromatography/mass spectrometry, microbore HPLC/electrospray ionization mass spectrometry (LC/ESI/MS), chemical ionization gas chromatography/mass spectrometry (CI/GC/MS), and matrix-assisted laser desorption mass spectrometry (MALDI/MS)], we were able to confirm that pig FMO1 was N-glycosylated and we were able to identify the site of N-glycosylation. Pig FMO1 contains two putative consensus sites of N-glycosylation. The results showed that pig FMO1 amino acid Asn120 was selectively N-glycosylated. Highly purified pig FMO1 avidly bound concanavalin A and reacted positively for carbohydrates by the periodic acid/Schiff's base method of analysis. In addition, treatment of pig FMO1 with endo-N-acetylglucosaminidase converted the enzyme to another species with a molecular mass approximately 5000 Da lower than that of the parent protein as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot experiments. Peptide mapping of pig FMO1 showed that the protein used in the study was not contaminated with another glycoprotein. MALDI/MS experiments showed that pig FMO1 was present with the expected molecular mass but that higher-molecular mass forms consistent with the presence of N-linked high-mannose oligosaccharide structures were also covalently attached to the enzyme. The presence of N-acetylglucosamine isolated from acid hydrolysates of the N-linked high-mannose oligosaccharide of pig FMO1 was confirmed by high-pH anion exchange HPLC studies and verified by CI/GC/MS studies of derivatized monosaccharide fractions. Further analysis of pig FMO1 proteolytic peptides by LC/ESI/MS showed that the only residue that was N-glycosylated in pig FMO1 was Asn120. Knowledge of the structural aspects of FMO may be useful in understanding the membrane association properties of the enzyme.

Amino Acid Sequence↗
PubMed1998

[The development of endothelial cell-to-cell junctions].

The endothelium forms the main barrier to the passage of macromolecules and circulating cells from blood to tissues. Endothelial permeability is in large part regulated by intercellular junction. The article here dicusses the development of endothelial cell-to-cell junction. The types of endothelial junctions, transduction, regulation of changes of endothelial cell-to-cell junction, the effects of the flow in vasculature and the leukocytic extravasation have been discussed. It was emphasized that the changes of endothelial junctions and skeleton were important in regulating endothelial permeability, leukocyte extravasation and reorganization of vascular endothelial cell-to-cell junction.

Adherens Junctions↗
PubMed1996

Clinical significance of the changes in serum fibronectin in severely burned patients.

The Agar gel single diffusion technique was used to investigate the changes in serum fibronectin (FN) in severely burned patients, and coupled with the study of simultaneous changes in the internal organ function, the development of MOF and severe systemic infection. The results suggested that the deficiency or decrease in serum FN made the host more prone to severe systemic infection, even to MOF.

Adolescent↗
PubMed1996

Clinical significance of the alterations of plasma prostaglandin E2 (PGE2) in severely burned patients.

Agar gel single diffusion and radio immunological analyses were employed to determine the levels of serum C3c, C4, IgA, IgM, IgG and plasma PGE2 in 24 severely burned patients. The results were compared with the development of postburn immunosuppression, severe infection and MOF. There were marked decreases in serum C3c, C4 and Ig, which were especially marked in patients with MOF. Furthermore, plasma PGE2 decreased markedly in patients with MOF and/or severe systemic infection. The results suggest that the decrease of deficiency in plasma PGE2 was closely related to the immunosuppression and the development of severe systemic infection and/or MOF, which supported the hypothesis that PGE2 might play a role in immunoprotection, but not immunosuppression, in burned patients.

Adolescent↗
PubMed1996

[An analysis of YPLL, WYPLL and VYPLL in Guangzhou, 1983-1994].

In order to assess the health status and risk of various diseases in the population of Guangzhou, the surveillance data of death in 1983-1994 in Guangzhou was analyzed by indicesas: year of potential life lost (YPLL), work year of lost (WYPLL) and valued year of potential life lost (VYPLL). It was indicated that both Chinese standardized mortality rates (CSMR) and Chinese standardized rates (CSYPLLR) had been declined from 448.2 x 10(-5) and 53.16/1000 to 398.6 x 10(-5) and 42.29/1000 during 1983-1994, respectively. It was suggested that the health status of inhabitants in Guangzhou had been gradually improved. Cancer lesion and poisoning, cardiovascular diseases rank top in CSYPLLR, were the most important diseases affecting life span of the inhabitants. Lesion and poisoning, infectious disease, psychotic disease, ranked the first in Chinese tandardized WYPLL rates (CSWYPLLR) and Chinese standardized VYPLL rates (CSVYPLLR), were important factors that periled the society labor force and economic development. By comparison of sex, both CSMR and CSYPLLR were higher in male than in female (u = 14.76, P < 0.01; u = 27.05, P < 0.01, respectively). Although both values of CSWYPLLR and CSVYPLLR were negative, they were still higher in male than in female. The zero-age-group was far more higher than all the other age groups in CSPLLR, CSWYPLLR and CSVYPLLR.

Adolescent↗
PubMed1996

Effects of m-nisoldipine on aortic calcium accumulation in rats with vascular calcium overload.

AIM: To study the effects of a novel calcium channel blocker, m-nisoldipine, on vascular calcium overload (VCO) at both tissue and cellular levels. METHODS: VCO was induced in Wistar rats by treatment with colecalciferol (Col, 400,000 IU.kg-1, p.o.) and an aqueous mixture of ethanol and polyethyleneglycol-400 for 3 d. The tissue and subcellular calcium contents of aorta were determined by atomic absorption spectrometer and electron probe microanalysis, respectively. RESULTS: Chronic treatment with m-nisoldipine (m-Nis, 1-15 mg.kg-1, p.o., bid) only had mild inhibition on the elevation of total calcium in aorta, and the dose-response relationship of m-Nis displayed a bell shape, with inhibition ratio of 24% only for m-Nis 2.5 mg.kg-1. The effect of verapamil (12.5 mg.kg-1, p.o., bid) was a little better than that of m-Nis. The intracellular VCO in medial smooth muscle cells of aorta were remarkably inhibited by m-Nis (2.5 mg.kg-1), with inhibition ratios of 72% for cytoplasm and 76% for mitochondrion. The calcium accumulation in nucleus was reduced to a lesser degree than those in cytoplasm and mitochondrion. CONCLUSION: As for aorta in VCO rats, m-Nis mainly had conspicuous inhibition on intracellular VCO in medial smooth muscle cells, particularly in cytoplasm and mitochondrion, but with little effect on extracellular calcium deposition at tissue level.

Animals↗
PubMed1996

Electrophysiological effects of felodipine on guinea pig papillary muscles.

AIM: To determine whether felodipine (Fel) has Ca2+ channel blocking effect in mammalian myocardium in comparison with those of nifedipine (Nif) and verapamil (Ver). METHODS: The action potentials (AP), the slow AP and the inward slow Ca2+ currents of guinea pig papillary muscles were studied using intracellular microelectrodes and voltage-clamp techniques. RESULTS: Fel 1, 3, and 10 mumol.L-1 concentration-dependently shortened APD30, APD50, and APD90 of the AP, while Vmax and APA were not affected. The effect of Fel was not reversible on washout. At 0.1, 1, 3, and 10 mumol.L-1, Fel depressed Vmax, APA, APD30, APD50, and APD90 of the slow AP in a dose-dependent manner. The inward slow Ca2+ currents were reduced by Fel 3 mumol.L-1. APD30, APD50, and APD90 of the first AP after rest were still shortened by Fel. When the stimulation frequency was elevated, the effect of Fel on the AP and slow AP decreased. The effect of Fel 3 mumol.L-1 on the slow AP was abolished in preparation pretreated with trifluoperazine. The threshold concentrations of Nif and Ver for the inhibition of APD50 of the slow AP (P < 0.05) were 0.1 and 1 mumol.L-1, respectively. The effect of Ver 3 mumol.L-1 on the fast AP was not reversible on washout, but that of Nif 3 mumol.L-1 was. When the stimulation frequency was elevated from 0.5 to 2 Hz, the effect of Nif 3 mumol.L-1 on the fast AP was reduced, but that of Ver 3 mumol.L-1 was increased. CONCLUSION: Fel inhibited mainly the resting state of the cardiac Ca2+ channel. The potency of Fel was about the same as that of Nif and about 10 times more potent than that of Ver.

Action Potentials↗