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Biomedical subjects

S H Zhang

Publications and source records attributed to S H Zhang.

At least 19 recordsLinked to original sources
PubMed2006

The common -318C/T polymorphism in the promoter region of CTLA4 gene is associated with reduced risk of ophthalmopathy in Chinese Graves' patients.

Studies in the past have clearly established that CTLA4 is a susceptible gene for Graves' disease (GD). However, association studies between CTLA4 and the risk of developing Graves' ophthalmopathy (GO) in GD patients have shown conflicting results. In this study, associations of five CTLA4 single nucleotide polymorphisms (-1722A/G, -1661A/G, -318C/T, +49G/A, CT60) with GD risk and GO susceptibility in GD patients were investigated in a Chinese population. Our results showed that either +49A/G or CT60 polymorphism was associated with GD susceptibility in the Chinese population. Significant differences in the distribution of the genotypes or alleles evaluated between GD patients with and without clinically evident GO were only found for -318C/T polymorphism (P = 0.03). Multiple logistic regressions revealed that the -318T allele was negatively associated with GO under both additive and dominant genetic models (adjusted OR = 0.56, 95%CI 0.35-0.89, P = 0.014; adjusted OR = 0.51, 95%CI 0.30-0.84, P = 0.009, respectively). Stratification analysis according to gender demonstrated different scenarios concerning the role of the -318T allele in GO risk: a significant protective role for GO was only confirmed in male but not in female GD patients. Haplotype analyses showed that only the haplotypes containing the -318T allele played a protective role in GO. In conclusion, results from this study suggested that the -318T allele might play a protective role in GO susceptibility for GD patients at least in the Chinese population. However, extended analyses with larger sample size should be carried out in patients from different ethnic origins to further verify this association.

Adult↗
PubMed2005

Determination of levodopa methyl ester and its metabolites in rat serum by CZE with amperometric detection.

A reliable and reproducible method, capillary zone electrophoresis with amperometric detection (CZE-AD), has been developed for separation and quantification of levodopa methyl ester (LDME) and its biotransformation products levodopa (L-DOPA) and dopamine (DA) in rat serum. A carbon-disk electrode was used as working electrode. The optimum conditions for CZE detection were 50 mmol L(-1) phosphate solution at pH 7.0 as running buffer, 17 kV as separation voltage, 1.0 V (vs Ag/AgCl, 3.0 mol L(-1)) as detection potential, and sample injection for 8 s at 17 kV. The linear ranges were from 2.4 x 10(-2) to 2.2 microg mL(-1) for LDME, 2.9 x 10(-1) to 49.5 microg mL(-1) for L-DOPA, and 1.4 x 10(-2) to 1.5 microg mL(-1) for DA with correlation coefficients of 0.9997, 0.9994, and 0.9999, respectively. The detection limits for LDME, L-DOPA, and DA were 14.6, 98.0, and 9.7 ng mL(-1), respectively. Recoveries were 80.3% for LDME, 93.5% for L-DOPA, and 86.5% for DA. This method was applied to serum samples after intravenous injection of LDME and L-DOPA to rats.

Animals↗
PubMed2005

Acupuncture for acute stroke.

BACKGROUND: Acupuncture-like sensory stimulation activates multiple efferent (nerve) pathways leading to altered activity in numerous neural systems. Acupuncture is widely accepted by Chinese people and it is increasingly requested by patients and their relatives in Western countries. OBJECTIVES: To assess the effectiveness and safety of acupuncture in patients with acute stroke. SEARCH STRATEGY: We searched the Cochrane Stroke Group trials register (last searched August 2003), the Chinese Stroke Trials Register (August 2003) and the Chinese Acupuncture Trials Register (August 2003). Electronic searches were performed in the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2003), MEDLINE (1966 to 2003), EMBASE (1980 to 2003), Alternative Medicine Database (1985 to 2003), CINAHL (1982 to 2003) and the Chinese Biological Medicine Database (1981 to 2003). Reference lists of systematic reviews and identified trials were handsearched. SELECTION CRITERIA: Randomised and quasi-randomised trials of acupuncture started within 30 days of stroke onset, compared with placebo/sham acupuncture or open control in patients with acute ischaemic and/or haemorrhagic stroke. Needling into skin was required for acupuncture. DATA COLLECTION AND ANALYSIS: Two reviewers selected trials for inclusion, assessed trial quality, and extracted the data independently. Authors of trials were contacted for missing data. MAIN RESULTS: Fourteen trials involving 1208 patients were included. Ten trials included patients with only ischaemic stroke. When acupuncture was compared with sham acupuncture or open control, there was a borderline significant trend towards fewer patients being dead or dependent (Odds ratio (OR) 0.66, 95% confidence interval (CI) 0.43 to 0.99), and significantly fewer being dead or needing institutional care (OR 0.58, 95% CI 0.35 to 0.96) in the acupuncture group after three months or more. There was also a significant difference favouring acupuncture in the mean change of global neurological deficit score during the treatment period (standardized mean difference (SMD) 1.17, 95% CI 0.30 to 2.04). Comparison of acupuncture with sham acupuncture only showed a statistically significant difference on death or requiring institutional care (OR 0.49, 95% CI 0.25 to 0.96), but not on death or dependency (OR 0.67, 95% CI 0.40 to 1.12), or change of global neurological deficit score (SMD 0.01, 95% CI -0.55 to 0.57). Severe adverse events with acupuncture (dizziness, intolerable pain and infection of acupoints) were rare (6/386, 1.55%). AUTHORS' CONCLUSIONS: Acupuncture appeared to be safe but without clear evidence of benefit. The number of patients is too small to be certain whether acupuncture is effective for treatment of acute ischaemic or haemorrhagic stroke. Larger, methodologically-sound trials are required.

Acupuncture Therapy↗
PubMed2005

Rosiglitazone, an agonist of peroxisome proliferator-activated receptor gamma, reduces pulmonary inflammatory response in a rat model of endotoxemia.

OBJECTIVE: The effect of rosiglitazone, a potent peroxisome proliferator-activated receptor gamma (PPAR-gamma) agonist, on pulmonary inflammation in endotoxemia was investigated. MATERIALS AND METHODS: Male Wistar rats were given either lipopolysaccharide (LPS, 6 mg/kg i.v.) or saline, pretreated with rosiglitazone (0.3 mg/kg i.v.) or its vehicle (dimethyl sulphoxide) 30 min before LPS. The selective PPAR-gamma antagonist GW9662 (0.3 mg/kg i.v.) was given 20 min before rosiglitazone. Wet/dry weight (W/D) ratio, myeloperoxidase (MPO) activity, malondialdehyde (MDA) as well as TNF-alpha and CINC-1 concentrations were measured in lung tissues 4 h after LPS injection. Expression of ICAM-1, NF-kappaB p65 and PPAR-gamma were also determined by immunohistochemistry or Western blot analysis. RESULTS: Rosiglitazone pretreatment significantly attenuated the increases in W/D ratio, MPO activity and MDA levels, and reduced pulmonary overproduction of TNF-alpha and CINC-1 as well as expression of ICAM-1 following endotoxemia. Rosiglitazone also inhibited the nuclear localization of NF-kappaB and up-regulated the expression of PPAR-gamma protein. The specific PPAR-gamma antagonist GW9662 abolished the effect of rosiglitazone. CONCLUSION: These findings suggest that PPAR-gamma agonists might be used as therapeutic agents in the therapy of inflammatory lung injury related to endotoxemia.

Anilides↗
PubMed2001

Quantitative determination of hydroxycinnamic acids in wheat, rice, rye, and barley straws, maize stems, oil palm frond fiber, and fast-growing poplar wood.

A new method has been developed for the quantitative determination of hydroxycinnamic acids participating in ester or ether linkages to the cell wall polymers. The method is based on mild alkaline hydrolysis followed by acid hydrolysis or mild alkaline hydrolysis, which partially removed esterified phenolic acids, and high-temperature concentrated alkaline treatment, which cleaved both the ester and ether linkages. It was found that traditional mild alkaline hydrolysis and acid hydrolysis released only part of the ester- and ether-linked phenolic acids, respectively. Approximately half (44.0-47.9%) of the total ester-linked p-coumaric acid and 18.2-32.6% of the total esterified ferulic acid remained ester-linked to the mild alkali-soluble lignin polymers, and 55.0-72.0% of the total ether-linked p-coumaric acid and 37.5-53.8% of the total ether-linked ferulic acid remained ether-linked to the solubilized lignin molecules after the acid hydrolysis. To correct this, a second mild alkaline hydrolysis of the alkali-soluble lignin preparations and acid hydrolysis of the solubilized lignin fractions, obtained from the first acid hydrolysis of the cell wall materials, was investigated. On the basis of this new method, a majority of the cell wall p-coumaric acid (55.8-81.5%) was found to be ester-linked to cell wall components, mainly to lignin, and about half of the cell wall ferulic acid is etherified through its phenolic oxygen to the cell wall lignin component, whereas the remainder is esterified to the cell wall hemicelluloses and/or lignin in different plant materials.

Chromatography, High Pressure Liquid↗
PubMed2001

Neurotrophin 3 is increased in the spontaneously hypertensive rat.

OBJECTIVE: To determine whether the noradrenergic sympathetic hyperinnervation in the spontaneously hypertensive rat (SHR), a genetic model of essential hypertension, is associated with changes in neurotrophin 3 (NT3) concentrations. METHODS: NT3 levels were measured using a sensitive enzyme-linked immunosorbent assay (ELISA) in the superior cervical ganglia (SCG), heart, mesenteric artery (MA) and blood of postnatal and mature SHR and normotensive Wistar-Kyoto (WKY) rats. RESULTS AND CONCLUSIONS: NT3 levels in SHR are significantly higher in the SCG during the first 4 postnatal weeks, and in the heart and MA from 2 to 10 weeks of age, compared with levels in WKY rats. The elevated NT3 found in the sympathetic ganglia and hyperinnervated organs of SHR indicates that NT3 may play an important role in the development of hyperinnervation, possibly by enhancing the survival and/or nerve sprouting of sympathetic neurons.

Aging↗
PubMed2001

Arterial remodeling in chronic sinoaortic-denervated rats.

The spontaneous variation of blood pressure is defined as "blood pressure variability" (BPV). The chronic sinoaortic-denervated (SAD) rat is a model of high BPV without sustained hypertension. Little is known about vascular remodeling in this model. In the present study, we examined blood pressure, vascular remodeling, and aortic angiotensin II concentration in chronic SAD rats in separate experiments. In experiment 1, intra-arterial blood pressure was continuously recorded in conscious unrestrained rats. The 16-week SAD rats had a significant increase in BPV and no change in the mean level of blood pressure over a 24-h period. In experiment 2, we measured structural changes of seven kinds of arteries by histologic method and computer image analysis and functional changes of thoracic aortas by isolated artery preparation. Structural remodeling after 16-week sinoaortic denervation was characterized by increase in wall thickness, wall area, and ratio of wall thickness to internal diameter, with different changes in internal diameter and external diameter in different arteries, indicating that arterial structural remodeling expresses itself mainly as vascular growth. This vascular growth might be caused by medial smooth muscle cell growth and collagen accumulation. Aortic contraction induced by norepinephrine was potentiated, whereas aortic relaxation induced by acetylcholine was attenuated after sinoaortic denervation. In experiment 3, plasma and aortic angiotensin II concentrations were determined by radioimmunoassay. The former remained unchanged, whereas the latter was significantly increased in 10-week SAD rats. It is concluded that in rats chronic sinoaortic denervation can produce vascular remodeling that might be related to increased BPV and an activated tissue renin-angiotensin system.

Angiotensin II↗
PubMed2001

Subcellular expression of UGT1A6 and CYP1A1 responsible for propofol metabolism in human brain.

AIM: To observe the subcellular expression of UDP-glucuronosyltransferase 1A6 (UGT1A6) and cytochrome P-450 1A1 (CYP1A1) mRNA in the human brain and investigate the effect of brain on extrahepatic metabolism of propofol. METHODS: Fifteen patients scheduled for craniotomy under propofol anesthesia were selected. Brain tis sue was taken and blood samples from the radial artery and the internal jugular vein were drawn simultaneously. PCR technique was used to detect UGT1A6 and CYP1A1 mRNA in the microsomes and mitochondria. Enzymatic activities were assayed. Blood propofol and propofol-glucuronide concentrations were measured with HPLC and GC, respectively. RESULTS: UGT1A6 mRNA was located mainly in the microsomes, and CYP1A1 mRNA was mainly in the mitochondria. The higher blood concentration of propofol and lower blood concentration of propofol-glucuronide were observed from the radial artery than from the internal jugular vein, respectively. The Km of UGT1A6 and CYP1A1 was (0.74 +/- 0.21) mmol and (548 +/- 50) mmol, respectively. The Vmax was (536 +/- 98) nmol . h-1 . mg-1 and (37 +/- 5) nmol . h-1 . mg-1, respectively. CONCLUSION: The human brain is an important organ for extrahepatic metabolism of propofol. The metabolism occurs within microsomes and mitochondria in brain.

Adult↗
PubMed2001

Synergistic effects of geldanamycin and antitumor drugs.

AIM: To study the effect of geldanamycin (GDM) on cell-cycle of human hepatoma BEL-7402 cells and the antitumor activity of cisplatin and mitomycin C in combination with GDM in vitro and in vivo. METHODS: MTT assay was used to determine the growth inhibition of hepatoma BEL-7402 cells. Cell cycle was analyzed by flow cytometry. Transplantable murine hepatoma 22 model was used to evaluate the antitumor activity of drugs in vivo. RESULTS: The IC50 value of GDM for hepatoma BEL-7402 cells by MTT assay was found to be 0.28 mumol.L-1. At concentrations of 0.1, 1.0, and 10 mumol.L-1, GDM reduced the proportion of S phase and induced G2/M arrest in BEL-7402 cells. At relatively low cytotoxic concentration, 0.1 or 0.2 mumol.L-1, GDM markedly potentiated the cytotoxicity of a series of chemotherapeutic agents including cisplatin, mitomycin C, adriamycin and cytarabine against BEL-7402 cells. The inhibition of tumor growth by cisplatin and mitomycin C was also enhanced in transplantable hepatoma 22-bearing mice when these agents were administered in combination with GDM 0.38 mg.kg-1. The synergistic effects were very significant with CDI < 0.7. CONCLUSION: These results suggest that GDM, as a biochemical modulator targeting Hsp90 function, may be potentially useful in cancer chemotherapy.

Animals↗
PubMed2001

[Compound EPSPs and action potential of mauthner cell evoked by skin stimulation in crucian carp].

OBJECTIVE: To investigate the effects of afferent excitatory inputs from skin on the excitability of Mauthner cell (M cell) of crucian carp. METHODS: Multiple-site intracellular recordings on the soma and the ventral dendrite (VD) of M cell and direct current stimulation on the skin surface of the fish's trunk were employed. RESULTS: Direct stimulation of the skin evoked 3 groups of compound excitatory postsynaptic potentials (EPSPs) on soma and VD of M cell. Group a EPSP had the lowest amplitude (< or = 0.35 mV), which was insensitive to high-frequency stimulation. It had the shortest latency (mean 1.9 ms) and could be recorded on the soma and the proximal end of VD. Group b EPSP had the highest amplitude (< or = 9.7 mV), which was increased when the recording electrode was moved from the soma to the distal end of VD. The latency of Group b (mean 4.5 ms) was shorter than that of Group c, but longer than that of Group a. We firstly found that action potential could be induced on the basis of Group b in M cell by skin stimulation. Group c EPSP was our new finding, which could only be evoked by higher intensity (noxious) stimulus (> or = 100 V). It had the longest latency (mean 13.5 ms) with amplitude between those of a and b, and was very sensitive to high frequency stimulation. All the three groups of EPSPs were superimposed with spike-like transient potentials, which were believed to be the sign of electrical synapse activities. CONCLUSIONS: (1) Action potential can be induced on M cell by skin stimulation, which is in controversy with previous reports; (2) the noxious skin stimulation can induce a late EPSP (Group c) in M cell; (3) the neural pathway projecting from skin to M cell is composed of a set of neuronal chains with different number of synaptic relays, in which short chains projected concentrically to the soma and the proximal part of VD, while long chains projected mainly to the distal part of VD; (4) both electrical and chemical synapses may exist in short and long pathways.

Afferent Pathways↗
PubMed2000

Preservation of the saphenous vein during inguinal lymphadenectomy decreases morbidity in patients with carcinoma of the vulva.

BACKGROUND: Traditional inguinal lymphadenectomy includes the removal of a portion of the saphenous vein. The authors hypothesized that preserving the saphenous vein would decrease morbidity without affecting treatment outcome. METHODS: A retrospective review of 83 patients with carcinoma of the vulva who underwent inguinal lymphadenectomy between 1990-1998 was performed. Postoperative short term and long term complications were evaluated. RESULTS: A total of 139 inguinal dissections were performed in 83 patients. The saphenous vein was preserved in 62 patients and ligated in 77 patients. The clinical characteristics of the patients, the operating time, and the estimated blood loss were not significantly different between the two groups. The incidence rate of short term complications including fever, seroma, phlebitis, lymphocyst, and deep venous thrombosis also was similar. Cellulitis occurred in 39% of the patients who underwent vein ligation compared with 18% of the patients who underwent a vein-sparing procedure (P = 0.006). Short term (< 6 months) lower extremity lymphedema occurred in 70% of the vein-ligated group compared with 32% of the vein-spared group (P < 0. 001). Chronic edema (>/= 2 years) was present in only 3% of the patients who underwent saphenous vein preservation compared with 32% of those who underwent vein ligation (P = 0.003). Chronic lymphedema in the vein-spared group was observed in only one patient who received postoperative radiation. Overall, individuals with preservation of the saphenous vein were less likely to develop complications (56% vs. 23%; P < 0.001). There was no difference in the rate of incidence of recurrent disease between the two groups. CONCLUSIONS: Preservation of the saphenous vein during inguinal lymphadenectomy reduces both the short term and long term postoperative complications without affecting treatment outcome. The saphenous vein should be preserved routinely in patients undergoing inguinal lymphadenectomy.

Aged↗
PubMed2000

[Comparison of genetic diversity among maize inbred lines based on RFLPs, SSRs, AFLPs and RAPDs].

RFLPs, SSRs, AFLPs and RAPDs were used to detect the genetic diversity among 15 maize inbred lines. A total of 56 probe enzyme combinations, 66 SSR primers, 20 RAPD primers and 9 AFLP primer combinations were identified with polymorphism among the entries, which produced 167, 201, 180 and 87 alleles respectively. SSR markers have the highest polymorphism information content (PIC, 0.47) and AFLP markers have the lowest value (0.36), while AFLP markers possess the highest assay efficiency index (Ai, 32.4). A comparison of genetic similarity matrices revealed that the estimates of correlation coefficients based on RFLPs, SSRs, AFLPs and RAPDs were significantly correlated, but the correlation of RAPD maker data with other markers was lower. These inbred lines were classified into five groups based on four molecular markers data, which are Tangsipingtou, Luda Red Cob, Lancaster, Reid, and PN group. They are consistent with the grouping based on the available pedigree data. Based on the results, we recommend RFLPs and SSRs for genetic diversity analysis among maize germplasm.

Genetic Variation↗
PubMed2000

[Studies on quality standards for Pollen Typhae(puhuang)].

OBJECTIVE: To work out quality standards for Pollen Typhae(Puhuang). METHOD: Isorhamnetin-3-O-neohesperidoside, typhaneoside, isorhamnetin and beta-sitosterol in Pollen Typhae marketed in ten cities of China were identified by TLC. The contents of isorhamnetin-3-O-neohesperidoside and typhaneoside were determined by HPLC. RESULT: The method is sensitive and specific for identifying isorhamnetin-3-O-neohesperidoside, typhaneoside, isorhamnetin and beta-sitosterol. The linear ranges of isorhamnetin-3-O-neohesperidoside and typhaneoside were 0.188-0.940 microgram with and average recovery of 97.77%; and 0.164-0.820 microgram with an average recovery of 98.42% respectively. CONCLUSION: The method can be used both qualitatively and quantitatively as standards for the quality control of Pollen Typhae.

Drugs, Chinese Herbal↗
PubMed2000

[Influence of monkshood root-peony root combination on inflamation-induced agents and free radicals].

OBJECTIVE: To find out the effect of monkshood root and peony root on inflammation-induced agents and free radicals when used separately and in combination. METHOD: Two drugs were made into decoctions separately and in combination, i.p., qd, for 7 d, red blood cell SOD and serum LPO were analysed and the anti-inflammatory actions were observed. RESULTS: In an experimental rat model with inflamed paw edema induced by carrageenin or formaldehyde and in a mouse model with ear swelling induced by xylene, the anti-inflammatory effect appeared stronger when the two drugs were used in combination, especially in comparison with the use of monkshood root alone. The exudation of blood capillaries and the contents of inflammation medium PGE2 were lowered; The activity of SOD extracted from rat or mouse red blood cells was enhanced, and the serum LPO, which was high in level when monkshood root was used alone, could be declined when the two drugs were used in combination. CONCLUSION: The drug combination is more effective in inhibiting inflammation and scavenging free radicals.

Aconitum↗
PubMed1999

Measurement of neurotrophin 4/5 in rat tissues by a sensitive immunoassay.

Neurotrophin 4/5 (NT4/5) is a member of the neurotrophin family known to exert survival and other effects on a variety of neurons including those within the motor, sensory and central populations. Although mRNA(NT4/5) has been found in various effector tissues of the rat and human, the concentration of NT4/5 protein in tissues has not been reported previously due to lack of suitable methodology. We present here a quantitative two-site enzyme-linked immunosorbent assay for the estimation of NT4/5 in pre- and postnatal rat tissues. The assay was performed using a combination of polyclonal and monoclonal antibodies to recombinant human NT4/5. Tissue samples were extracted at neutral pH. Results show that the assay is highly specific for NT4/5 with a sensitivity of 1 pg/ml, and reproducible with intra- and inter-assay variation coefficients of 3.0 and 6.3%, respectively. NT4/5 was found in most embryonic tissues examined at gestation day 17 and 21, but was rarely detectable in postnatal tissues, with the notable exception of the testis. The availability of an immunoassay for the estimation of NT4/5 protein in rat tissues should contribute to the understanding of the physiology of this little understood neurotrophic factor.

Aging↗
PubMed1999

Identification of the cell cycle regulator VCP (p97/CDC48) as a substrate of the band 4.1-related protein-tyrosine phosphatase PTPH1.

The human band 4.1-related protein-tyrosine phosphatase PTPH1 was introduced into NIH3T3 cells under the control of a tetracycline-repressible promoter. Ectopic expression of wild type PTPH1 dramatically inhibited cell growth, whereas a catalytically impaired mutant showed no effect. To identify the direct target of PTPH1 in the cell, we generated a substrate-trapping mutant, in which an invariant aspartate residue was changed to alanine (D811A in PTPH1). The PTPH1-D811A mutant trapped primarily a 97-kDa tyrosine-phosphorylated protein, which was determined to be VCP (also named p97 or yeast CDC48), from various cell lysates in vitro. However, when expressed in mammalian cells, the D811A mutant was observed to contain high levels of phosphotyrosine and did not trap substrates. Mutation of tyrosine 676 to phenylalanine (Y676F) in the PTPH1-D811A mutant led to a marked reduction in phosphotyrosine content. Furthermore, this double mutant specifically trapped VCP in vivo and recognized the C-terminal tyrosines of VCP, whose phosphorylation is important for cell cycle progression in yeast. Like wild type PTPH1, this double mutant also inhibited cell proliferation. Moreover, induction of wild type PTPH1 resulted in specific dephosphorylation of VCP without changing the overall phosphotyrosine profile of the cells. VCP has been implicated in control of a variety of membrane functions, including membrane fusions, and is a regulator of the cell cycle. Our results suggest that PTPH1 may exert its effects on cell growth through dephosphorylation of VCP, thus implicating tyrosine phosphorylation as an important regulator of VCP function.

3T3 Cells↗