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Biomedical subjects

W Zhu

Publications and source records attributed to W Zhu.

At least 91 records · Page 5Linked to original sources
PubMed2001

Presence of endogenous morphine and morphine 6 glucuronide in human heart tissue.

Human atria contain the opiate alkaloids morphine and morphine 6 glucuronide as determined by high performance liquid chromatography coupled to electrochemical detection. This method found endogenous morphine and morphine 6 glucuronide at 106.28+/-61.58 and 48.32+/-24.63 (+/- SD) ng/gm wet weight, respectively. Identification of these opiates was confirmed by nano electrospray ionization double quadrupole orthogonal acceleration time of flight mass spectrometry. Furthermore, human saphenous vein fragments did not contain morphine as determined by these methods. Fragmentation from a selected precursor ion by collision-induced dissociation of endogenous morphine 6 glucuronide (462.14 da) yields morphine (286.14 Da) obtained from the heart tissues and with the authentic material, further demonstrating the presence of endogenous morphine. Thus, vascular tissues appear to contain endogenous opiate alkaloids.

Chromatography, High Pressure Liquid↗
PubMed2001

[Pharmacognostical studies on cortex Indigoferae Pseudotinctoriae].

This paper reported the studies on descriptions, microscopical characteristics of cross section and podwer, chemical examination and TLC of Cortex indigoferae pseudotinctoriae. These studies provided referential information for clinics, quality control, development and identification of this crude drug.

Drugs, Chinese Herbal↗
PubMed2001

[The prevalence of renal artery stenosis in patients with coronary artery disease].

OBJECTIVE: To understand the prevalence of renal artery stenosis(RAS) in patients with coronary artery disease(CAD) and the relations among coronary artery disease, renal artery stenosis, hypertension and renal insufficiency. METHODS: 280 patients with coronary artery disease or suspected coronary disease were carried out renal artery angiography after coronary angiography over 1 year period. RESULTS: Of the total patient cohort, 43(15.3%) had significant RAS (> or = 50%), 3(1.0%) were obstructed and 14 (5.0%) were bilateral. 36 (19.1%) were diagnosed as having significant RAS among 188 CAD patients. 7 patients with significant RAS were found among 92 patients without significant coronary artery stenosis, all of them were found in the group of 22 patients with mild coronary artery atheroscloresis. The prevalence of significant RAS was 19.6% and 7.9% as referred to with or without hypertension, P < 0.05. 10 patients (55.6%) had significant RAS in 18 patients with mild renal insufficiency as compared to 33 patients (12.6%) had significant RAS in 262 patients with normal renal function, P < 0.05. In the subgroup of CAD, the prevalence of significant RAS were 15.3%, 17.1%, 25.4% in single vessel disease, two vessel disease and triple vessel disease patients, P < 0.05. 35 patients (81.4%) had hypertension among these 43 patients with RAS with 24 (56.0%) patient's blood pressure difficult to control. CONCLUSIONS: RAS is a frequent finding in patients with CAD, especially in triple vessel disease patients. Hypertension is closely related to RAS, it should be the risk factor of RAS, and can be the clinical manifestation of RAS. CAD patients with renal insufficiency but without history of chronic glomerulonephritis may indicate RAS.

Adult↗
PubMed2001

[Relationship between gene polymorphism at the apolipoprotein E locus and serum lipid profile in urban children of school age in Beijing].

OBJECTIVE: To study the relationship between gene polymorphism at the apolipoprotein E (ApoE) locus and serum lipid levels in children of school age. METHODS: Blood samples were collected from 307 normal children aged 7 to 11 years, including 150 boys and 157 girls, and their serum lipid profile, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), apolipoprotein B(apoB), apoprotein A1 (ApoA I) and lipoptoein alpha[LP (alpha)], were detected and their ApoE-Hha I gene polymorphism were tested by the PCR-RFLP method. RESULTS: The detection rates for the most frequent genotype ApoE3/3 was 54.7%, other genotypes E4/3, E4/4, E3/2, E4/2 and E2/2 were 23.8%, 9.1%, 8.1%, 3.9% and 0.3%, respectively, in 307 children, with no significant difference between girls and boys(P > 0.05). Frequency of the often seen allele E3 was 70.7%, and that of E4 and E2 was 23.0% and 6.4, respectively, with E4 significantly higher than and E2 similar to that in the other domestic reports. The levels of TC, LDL-C, ApoA I and ApoB were higher in boys with genotypes E4/3 and E3/3 than those with genotypes E3/2 and E4/2. Levels of TC and ApoA I in the boys with genotype E3/2 were higher, with TC of 4.28 mmol/L and ApoA I of 3.41 mmol/L. There were no significant difference in serum lipid levels of girls with different genotypes(P > 0.05). There also was no significant difference in the ApoE-Hha I genotype distribution between normal children and those with high TC. ApoE2 could decrease the level of TC by 0.377 mmol/L, and LDL-C by 0.329 mmol/L. CONCLUSIONS: Serum level of TC associated with polymorphism of ApoE gene carrier in boys, with the lowest levels of TC, LDL-C and ApoE in three with allele E2.

Apolipoprotein A-I↗
PubMed2001

[Development of a diagnostic kit of enzyme-linked immunoassay for detecting serum anti-hepatitis E virus IgG].

OBJECTIVE: To develop a diagnostic kit for detecting serum anti-hepatitis E virus (HEV) IgG with enzyme-linked immunoassay (ELISA). METHODS: The diagnostic kit of detecting anti-HEV IgG with ELISA was prepared by two synthetic HEV peptides used for coating the solid-phase to capture the antibody against HEV in serum, and then by horseradish peroxidase antihuman IgG (gamma chain) added as the second antibody to bind the anti-HEV IgG in serum. Its sensitivity, specificity, precision and stability were measured and clinically evaluated. RESULTS: The sensitivity, specificity, and precision of the diagnostic kit detected by the China National Institute for the Control of Pharmaceutical and Biological Products were 90% (1/10), 100% (0/30) and < 15%, respectively, meeting the national standards for detecting serum anti-HEV IgG with ELISA. The ELISA Kit is stable for 1 year at least under 4 degrees C. The total consistency rates were 100% (43/43) and 96.6% (86/89), as compared with Genelabs and Singaporean DBL kits. This diagnostic kit for detecting serum anti-HEV IgG with ELISA was evaluated and approved by the State Drug Administration, China and a certificate was conferred in 1998. CONCLUSIONS: The diagnostic kit for detecting anti-HEV IgG with ELISA can be used for epidemiological studies and clinical diagnosis of HEV infection.

Antibodies, Viral↗
PubMed2001

[Influence of fluid shear stress on the expression of monocyte chemotactic protein-1 by vascular endothelial cells].

OBJECTIVE: To study the effect of fluid shear stress on the expression of monocyte chemotactic protein-1(MCP-1) by vascular endothelial cells and its role in the early stages of atherogenesis(AS). METHODS: Parallel plate flow chamber was used to expose vascular endothelial cells to different shear stress. Sandwich ELISA (enzyme-linked immunosorbent assay) and RT-PCR (reverse transcription polymerase chain reaction) were applied to detect MCP-1 protein and mRNA respectively. RESULTS: Under 0.72 Pa shear stress, MCP-1 mRNA expression in endothelial cells reached a high level in 5 hours, but decreased to below the control level (P < 0.001) after 12 hours. The expression of MCP-1 mRNA showed a time dependent increase, which became slower 5 hours later. When different shear stress (0.30, 0.72, 2.40 Pa) was loaded for the same period of time (5 h), MCP-1 increased to above twice the control level, while its mRNA expression increased threefold as compared to the static control. CONCLUSIONS: The expression of MCP-1 reacts strongly to fluid shear stress. The steady laminar flow down regulates the gene expression of MCP-1. These results may help to explain why AS lesions tends to occur at the site of turbulent blood flow.

Cells, Cultured↗
PubMed2001

[Morphological changes and quantitative DNA analysis of Schwann cells in peripheral nerves after high voltage electrical injury].

OBJECTIVE: To explore the characteristics and the mechanism of the injury of Schwann cells and nerve fibres of the peripheral nerves inflicted by high voltage electricity. METHODS: Rabbits injured by high voltage electricity were employed as the model. Thirty rabbits were randomly divided into control (9) and experimental (21) groups. The dynamic quantitative DNA analysis and the change of the morphology and structure of the sciatic nerve were observed with LM and EM on 0, 3, 7, 10, 14 and 21 postburn days (PBDs), respectively. RESULTS: There was continuous degeneration of the axon and medullary sheath of sciatic nerve tissue and its neogenesis was inhibited. The DNA synthesis in Schwann cell initiated on 3 postburn day (PBD). The distribution of the current was heterogeneous on the cross section of peripheral nerve fibres. CONCLUSION: The obvious features of peripheral nerve injured by high voltage electricity included delayed initiation of the DNA synthesis of Schwann cell and the secondary necrosis and inhibition of neogenesis process of Schwann cell.

Animals↗
PubMed2001

Effects of acidum vitamin A on tyrosinase activity.

OBJECTIVE: To investigate the effect of acidum vitamin A on tyrosinase activity and provide experimental evidence for therapy of pigment disorder of skin. METHODS: Tyrosinase activity was estimated by measuring the rate of oxidation of DL-dopa. RESULTS: The levels of tyrosinase activity in the acidum vitamin A group were significantly greater than those of the control group (P < 0.01). CONCLUSION: Tyrosinase activity can be increasingly induced by acidum vitamin A.

Humans↗
PubMed2001

[The mechanism of percutaneous transluminal balloon angioplasty as assessed by intracoronary ultrasound].

OBJECTIVE: To elucidate the mechanism of coronary balloon angioplasty intracoronary ultrasound imaging. METHOD: Intracoronary ultrasound imaging was performed in 68 coronary arteries of 52 patients. Ultrasound images obtained at the treatment site before and after balloon angioplasty were analyzed quantitatively for cross-sectional lumen area, area enclosed by internal elastic lamina (IELA) and plaque area. Qualitative analysis included assessment of presence of dissection, plaque composition and plaque topography. RESULTS: The internal elastic lamina area was significantly enlarged after balloon angioplasty [(6.67 +/- 1.45) mm(2) vs (8.14 +/- 1.13) mm(2), P < 0.05]. The difference between IELA before and after balloon angioplasty DeltaIELA was different among different plaques (fatty plaque 1.84 mm(2), fibrous plaque 1.52 mm(2), calcified plaque 0.40 mm(2), mixed plaque 1.23 mm(2)). 85% of the lesions had dissection in some degree after PTCA. Severe dissections occurred mostly in calcified lesions. CONCLUSION: The improvement in lumen dimensions after coronary balloon angioplasty is a result of both vessel stretch, as demonstrated by a larger internal elastic lamina area at the treated site, and dissection. Calcified lesions will have less vessel stretch and severer dissection after balloon angioplasty.

Adult↗
PubMed2001

[An experimental study of the sciatic nerve injury by high voltage electricity in rabbits].

OBJECTIVE: To explore the pathological and myoelectric-physiological changes and the mechanism of the early postburn sciatic nerve injury by high voltage electricity in rabbits. METHODS: Apparatus producing high electricity was established with a special-designed microrecorder of digital reserve. The electrical current values were determined by computer responsive analysis system with the concomitant determination of myoelectric-physiology and pathomorphology. RESULTS: When the current was set to be 50 HZ, the average indentical resistance value of the nerve tissue was (5.99 +/- 0.88) k omega and the average current value was 83.5 mA/cm2. There exhibited different degrees of sciatic nerve injury when examined by myoelectric-physiological and pathophysiological measures. CONCLUSION: Peripheral nerve could be injured by current of high voltage electricity.

Animals↗
PubMed2001

[Role of epithelial cell proliferation and apoptosis in human middle ear cholesteatoma].

OBJECTIVE: To determine the role of middle ear epithelial cell proliferation and apoptosis in the pathogenesis of human cholesteatoma. METHOD: 33 cholesteatoma, 25 auditory meatal skin of cholesteatoma and 10 normal human auditory meatal skin were detected by using immunohistochemistry analysis for cell proliferation with Ki 67, PCNA and PCNA antibody and TUNTEL methods for cell apoptosis. RESULT: PCNA expression and apoptosis cells exists different quantity in cholesteatoma, auditory metal skin of cholesteatoma and normal human auditory meatal skin and distributes in various cell layer. There were positive correlation between p53 and PCNA as well as negative correlation between p53 and apoptosis. CONCLUSION: The dyregulation of proliferation and apoptosis in keratinocyte is important in pathogenesis of cholesteatoma.

Adolescent↗
PubMed2001

[Gene polymorphism at apoB locus and the serum lipids profile in children].

The relations of gene polymorphism at the apolipoprotein B locus and serum lipid profile in children was studied in 308 normal 7-11 year-old children, including 151 boys and 157 girls. Blood samples were collected for all subjects, and then the serum and blood clot were separated. Serum lipids, including TC, TG, LDL-C, HDL-C, apoB, apoA I and Lp(a) were detected. Genome DNA was extracted from blood clot, then apoB-Xba I gene polymorphism were tested by PCR-RFLP method. The results showed that the distribution of apoB-Xba I genotype in 308 children accorded with Hardy-Weiberg inheritance equilibrium law. The frequency of heterozygote(+/-) was 13.3%, allele(+) was 0.067. The frequency of allele(+) was closed to the internal and Japanese reports (0.033 and 0.04), but much less than the Caucasians (0.50). This showed a ethnic and population difference in the inheritance variation. The average LDL-C levels of the heterozygotes(+/-) were 2.17 mmol/L, no difference compared with homozygotes(-/-) (2.21 mmol/L, P > 0.05). There was also no difference for the genotype distribution between the hyperlipidemia group and control group, which may be the results of no enough sample size and the sample selection, and so on. On the other hand, in normal children, serum lipids controlled by many genes, the effect of a single gene might be small. More studies and analysis on the relationship between serum lipids and multiple genes in multisites should be the next step.

Apolipoproteins B↗
PubMed2001

[Expression of matrix metalloproteinasa-2,9 in cholesteatoma and middle ear cancer].

OBJECTIVE: To study various expressions and roles of MMP-2, 9 in cholesteatoma and middle ear cancer. METHODS: MMP-2 and MMP-9 were detected with immunohistochemical methods using monoclonal antibody in 36 cholesteatomas, 10 CAMS and 16 middle ear cancer. RESULTS: The stain in cholesteatoma was stronger than that in CAMS and NAMS. Expressions of MMP-2, 9 were seen in all layers of the epithelium in CA and the stain was strongest in basement membrane. The positive rates of stain was 83% and 50% in CA and CAMS respectively. There was weak stain in 2 NAMS. In middle ear cancer, the expression rates of MMP-9 and MMP-2 were 50% (8/16) and 56.25% (9/16) respectively. The expression level was correlated with tumor differentiation and its clinical stage. Expressions of MMP-2 and MMP-9 were closely related in cholesteatoma. There was no relationship between expressions of MMP-2 and MMP-9 in middle ear cancer. CONCLUSION: Cholesteatoma has a similar feature with middle ear cancer in invading surrounding of surround bone matrix. The disorder between MMPs and its inhibitor was one of reasons for bone absorption of cholesteatoma and middle ear cancer.

Adolescent↗
PubMed2001

[Determination of beryllium in atmospheric particulate by graphite furnace atomic absorption spectrophotometer using aluminium as a matrix modifier agent sampling with micropore filter membrane].

Beryllium in the atmospheric particulates is collected with 0.22 micron pore diameter micropore filter membrane, which is determined by graphite furnace atomic absorption spectrophotometer using aluminium as a matrix modifier agent. This sampling method shown several advantages: easy, complete and fast digestion; low membrane blank; high elution recovery, standard addition recovery, precision and accuracy. The addition of 800 mg.L-1 aluminium to beryllium solution allows ashing temperature of 2,000 degrees C. The detection limit of 13.5 ng was obtained.

Air Pollutants↗
PubMed2000

Insulin prevents cardiomyocytes from oxidative stress-induced apoptosis through activation of PI3 kinase/Akt.

BACKGROUND: Loss of cardiomyocytes by apoptosis is proposed to cause heart failure. Reactive oxygen species induce apoptosis in many types of cells including cardiomyocytes. Because insulin has been reported to have protective effects, we examined whether insulin prevents cardiomyocytes from oxidative stress-induced apoptotic death. METHODS AND RESULTS: Cultured cardiomyocytes of neonatal rats were stimulated by hydrogen peroxide (H(2)O(2)). Apoptosis was evaluated by means of the TUNEL method and DNA laddering. Incubation with 100 micromol/L H(2)O(2) for 24 hours increased the number of TUNEL-positive cardiac myocytes (control, approximately 4% versus H(2)O(2), approximately 23%). Pretreatment with 10(-)(6) mol/L insulin significantly decreased the number of H(2)O(2)-induced TUNEL-positive cardiac myocytes (approximately 12%) and DNA fragmentation induced by H(2)O(2). Pretreatment with a specific phosphatidylinositol 3 kinase (PI3K) inhibitor, wortmannin, and overexpression of dominant negative mutant of PI3K abolished the cytoprotective effect of insulin. Insulin strongly activated both PI3K and the putative downstream effector AKT: Moreover, a proapoptotic protein, BAD:, was significantly phosphorylated and inactivated by insulin through PI3K. CONCLUSIONS: These results suggest that insulin protects cardiomyocytes from oxidative stress-induced apoptosis through the PI3K pathway.

Animals↗
PubMed2000

Functional analyses of three Csx/Nkx-2.5 mutations that cause human congenital heart disease.

A homeodomain-containing transcription factor Csx/Nkx-2.5 is an important regulator of cardiogenesis in mammals. Three different mutants, Gln170ter (designated A) and Thr178Met (designated B) in the helix 2 of the homeodomain and Gln198ter mutation (designated C) just after homeodomain, have been reported to cause atrial septal defect with atrial ventricular block. We here examined the functions of these three mutants of Csx/Nkx-2.5. The atrial natriuretic peptide (ANP) promoter was activated by wild type Csx/Nkx-2.5 (WT, approximately 8-fold), B ( approximately 2-fold), and C ( approximately 6-fold) but not by A. When A, B, or C was cotransfected into COS-7 cells with the same amount of WT, WT-induced activation of the ANP promoter was attenuated by A and B (A > B), whereas C further enhanced the activation. Immunocytochemical analysis using anti-Myc tag antibody indicated that transfected Myc-tagged WT, B, and C were localized in the nucleus of both COS-7 cells and cardiomyocytes of neonatal rats, whereas A was distributed diffusely in the cytoplasm and nucleus in COS-7 cells. Electrophoretic mobility shift assay showed that Csx/Nkx-2.5-binding sequences were bound strongly by WT and C, weakly by B, but not by A. Immunoprecipitation and GST pull-down assay revealed that WT and all mutants interacted with GATA-4. The synergistic activation of the ANP promoter by WT and GATA-4 was further enhanced by C but was inhibited by A and B. In the cultured cardiomyocytes, overexpression of C but not WT, A, or B, induced apoptosis. These results suggest that although the three mutants induce the same cardiac phenotype, transactivation ability and DNA binding ability are different among the three mutants and that apoptosis may be a cause for C-induced cardiac defect.

Animals↗
PubMed2000

The roles played by crucial free radicals like lipid free radicals, nitric oxide, and enzymes NOS and NADPH in CCl(4)-induced acute liver injury of mice.

Mice were administered a single dose of carbon tetrachloride (CCl(4)) to induce acute liver injury. We found that lactate dehydrogenase (LDH) and glutamic pyruvic transaminase (GPT) levels in serum, as well as the level of thiobarbituric acid reaction substances (TBARS) in liver homogenate increased significantly in a manner both dose dependent and time dependent after CCl(4) administration. Such results suggest that the liver is susceptible to CCl(4) treatment and that lipid peroxidation is associated with CCl(4)-induced liver injury. The spin-trapping electron paramagnetic resonance (EPR) method was used to detect nitric oxide (NO) level in liver. The chemiluminescence method was also employed to measure the NO(2)(-)/NO(3)(-) concentration in serum. The NO levels in liver tissues and NO(2)(-)/NO(3)(-) concentration in serum were found to decrease significantly both in a dose-dependent manner and in time course after CCl(4) treatment. The nitric oxide synthase (NOS) II activity in the liver, in contrast, was found to increase significantly. Our study suggests that not only should the expression of NOS be analyzed but NO organ and blood concentration must be measured in the study of diseases involving nitric oxide. L-arginine treatment had no significant effect on the liver function of CCl(4)-treated mice. It was found that NO donor sodium nitroprusside (SNP; 50 or 100 microg/kg) treatment resulted in decreases of LDH, GPT, and TBARS levels, leading to a protective effect on CCl(4)-treated mice. On the other hand, N(G)-nitro-L-arginine methyl ester (L-NAME, 100 or 300 mg/kg) treatment caused more severe liver damage. Moreover, we have found in an in vitro EPR study that SNP could scavenge lipid peroxyl radical LOO&z.rad;. The above results together suggest that NO may protect CCl(4)-induced liver injury through scavenging lipid radical, inhibiting the lipid peroxidation chain reaction. On the basis of our analysis, we put forth two explanations for the stated discrepancy between NOS II and NO production: (i) NO was used up gradually in terminating lipid peroxidation and (ii) NADPH was depleted (on the basis of correlation evidence only).

Alanine Transaminase↗