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Biomedical subjects

C Zhao

Publications and source records attributed to C Zhao.

At least 73 records · Page 4Linked to original sources
PubMed2001

Three new glycosides from Sinopodophyllum emodi (Wall.) Ying.

Tow new aryltetralin-type lignan glycosides: methyl epipodophyllate 7'-O-beta-D-glucopyranoyl-(1-->6)-beta-D-glucopyranoside (1), 4-demethylepipodophyllotoxin 7'-O-beta-D-glucopyranoside (2), and a new phenyl ethanol glycoside: phenyl ethanol 4-O-beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside (3), along with three known compounds: junipetriolosides (4), 3,4-dihydroxy-phenyl ethanol (5), and 4-hydroxy-phenyl ethanol (6) were isolated and identified from the n-butanol extract of the roots and rhizomes of Sinopodophyllum emodi (Wall.) Ying. The structures of the above were established by means of spectral data and chemical methods.

Glycosides↗
PubMed2001

Two new podophyllotoxin glucosides from Sinopodophyllum emodi (Wall.) Ying.

Two new aryltetralin-type lignans, isopodophyllotoxin 7'-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1) and 4-demethyl-picropodophyllotoxin 7'-O-beta-D-glucopyranoside (2), along with eight known podophyllotoxin derivatives: 4-demethyl-podophyllotoxin 7'-O-beta-D-glucopyranoside (3), podophyllotoxin 7'-O-beta-D-glucopyranoside (4), deoxypodophyllotoxin (5), picropodophyllotoxin (6), podophyllotoxin (7), 4-demethyl-picropodophyllotoxin (8), 4-demethyl-podophyllotoxin (9), and 4-demethyl-deoxypodophyllotoxin (10), were isolated from the roots and rhizomes of Sinopodophyllum emodi (Wall.) Ying (Berberidaceae). Their structures were identified based on NMR spectral data and chemical evidence.

Glucosides↗
PubMed2001

Expression and distribution of lactate/monocarboxylate transporter isoforms in pancreatic islets and the exocrine pancreas.

Transport of lactate across the plasma membrane of pancreatic islet beta-cells is slow, as described by Sekine et al. (J Biol Chem 269:4895-4902, 1994), which is a feature that may be important for normal nutrient-induced insulin secretion. Although eight members of the monocarboxylate transporter (MCT) family have now been identified, the expression of these isoforms within the exocrine and endocrine pancreas has not been explored in detail. Using immunocytochemical analysis of pancreatic sections fixed in situ, we demonstrated three phenomena. First, immunoreactivity of the commonly expressed lactate transporter isoform MCT1 is near zero in both alpha- and beta-cells but is abundant in the pancreatic acinar cell plasma membrane. No MCT2 or MCT4 was detected in any pancreatic cell type. Second, Western analysis of purified beta- and non-beta-cell membranes revealed undetectable levels of MCT1 and MCT4. In derived beta-cell lines, MCT1 was absent from MIN6 cells and present in low amounts in INS-1 cell membranes and at high levels in RINm5F cells. MCT4 was weakly expressed in MIN6 beta-cells. Third, CD147, an MCT-associated chaperone protein, which is closely colocalized with MCT1 on acinar cell membranes, was absent from islet cell membranes. CD147 was also largely absent from MIN6 and INS-1 cells but abundant in RINm5F cells. Low expression of MCT1, MCT2, and MCT4 contributes to the enzymatic configuration of beta-cells, which is poised to ensure glucose oxidation and the generation of metabolic signals and may also be important for glucose sensing in islet non-beta-cells. MCT overexpression throughout the islet could contribute to deranged hormone secretion in some forms of type 2 diabetes.

Animals↗
PubMed2001

[The sieving performance of a new polyethersulfone hollow fiber plasma fractionation membrane].

Plasma fractionation membrane is very important in double filtration plasmapheresis. We studied a new polyethersulfone hollow fiber membrane plasma fractionator and evaluated the effect of time, transmembrane pressure (TMP) and mean shear rate on the sieving coefficient (SC) during membrane plasma fractionation. The sieving coefficients of various proteins reached their maximum values at 40 min at the plasma flow rate QI = 30 ml/min and plasma filtrated flow rate QF = 20 ml/min. The QF increased with the increase of TMP, and the point of the intersection of the curve of the QF vs. TMP and the SC vs. TMP was regarded as the ideal condition for plasma fractionation. The plasma filtrated rate PFR = QF/QI = 0.6-0.7. The TMP changed with the change of the mean shear rate, and the mean shear rate had little effect on the SC. The data is of significance to the application of plasma fractionation membrane.

Membranes, Artificial↗
PubMed2001

[Influence of environmental factors on CH4 emission from Reed Wetland].

Determination of CH4 emission from reed wetland in Liaohe delta, China using closed chamber(enclosure area 0.64 m2) technique showed that average emission rate of CH4 was 520 micrograms.m-2.h-1 with significant seasonal patterns. When soil redox potential reached -110 mV, CH4 occured and increased with its decrease. CH4 emission was also influenced by water management and reduced with deep water cover. During the period of measurement, there was positive relation between temperature and CH4 flux(R2 = 0.196, n = 21, P < 0.05). In addition, the experimental result also showed that the methanogenic activites in 0-5 cm soil layer were higher and decreased obviously with soil deepening.

Methane↗
PubMed2001

Comparison of cardiac sympathetic nervous function with left ventricular function and perfusion in cardiomyopathies by (123)I-MIBG SPECT and (99m)Tc-tetrofosmin electrocardiographically gated SPECT.

UNLABELLED: The objective of this study was to clarify the relationship between cardiac sympathetic nervous function (CSNF) and left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). METHODS: Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y), consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and (99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake and wall thickening on electrocardiographically gated SPECT. As quantitative parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum ratio (H/M) and percentage washout were calculated from early and delayed planar images. As quantitative regional parameters, the regional uptake and percentage washout of MIBG were calculated from SPECT images dividing the left ventricle into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction were calculated as the parameters of global LV perfusion and function. As quantitative regional parameters, the regional uptake and wall thickening were also calculated for the 12 myocardial segments using the quantitative gated SPECT software. Multiple linear regression analysis was performed to investigate the correlations between the parameters from the 2 studies. RESULTS: In DCM and HCM, multiple linear regression analysis of the regional parameters showed significant correlations between LV function and CSNF (P < 0.0001) and between LV perfusion and CSNF (P < 0.0001). According to the partial correlation coefficients, washout and early uptake of MIBG were the most significant factors for predicting LV function and LV perfusion, respectively. CONCLUSION: In cardiomyopathies, CSNF was closely related to LV function. The quantitative parameters of MIBG washout could reflect cardiac functional impairment. Early MIBG uptake might be determined by myocardial perfusion in cardiomyopathies.

3-Iodobenzylguanidine↗
PubMed2001

[The growth hormone and insulin-like growth factors axis in liver failure patients].

OBJECTIVE: To measure circulating concentration of growth hormone (GH), insulin-like growth factors 1 (IGF-1), and it's binding protein 1 (IGFBP1) and binding protein 3 (IGFBP3) in patients with sever hepatitis, and to survey the clinical significance of GH-IGFS axis. METHODS: The study population consisted of 18 patients with liver failure caused by serious virous hepatitis, and of 20 normal volunteers. Serum concentration of GH, IGF-1, IGFBP1 and IGFBP3 was determined by ELISA. Liver biochemistric functions were measured by routine methods. RESULTS: Serum concentrations of IGF-1 and IGFBP3 were equally reduced (5.5microgram/ml +/- 6.2 microgram/ml vs 17.6 microgram/ml +/-7.0 microgram/ml, and 2.4 microgram/ml +/-1.3 microgram/ml vs 9.4 microgram/ml +/- 1.7microgram/ml, P<0.001, respectively); increased serum GH and IGFBP1 were observed (9.1ng/ml +/-12.4ng/ml vs 1.6ng/ml +/-2.4ng/ml, P<0.05; 67.9ng/ml+/-50.2ng/ml vs 45.8ng/ml+/-33.1ng/ml, P<0.01) in liver failure patients as compared with the controls. The positive relationship between IGF-1 and IGFBP3 (r=0.91, P<0.001) was observed. The closed relation between the serum IGF-1 and the prognosis of patients was also obtained. IGF-1<10 microgram/ml was in accord with 90% accurate rate of predicted death. CONCLUSIONS: The GH-IGFs axis is significantly abnormal in liver failure patients, suggesting the existence of GH resistance in these patients. Serum IGF-1 may act as a predictor for their prognosis.

Adult↗
PubMed2001

[A prospective study on histological and serological changes after interferon alpha-2b treatment in patients with chronic hepatitis B infection].

OBJECTIVE: To investigate the histological changes in liver biopsies and HBV DNA changes in sera induced by 18 weeks of interferon alpha-2b therapy in patients with chronic hepatitis B infection. METHODS: Twenty-two patients were enrolled into this prospective study. All patients had a liver biopsy within 1 week before starting interferon therapy. Interferon alpha-2b was given at a dose of 3MU thrice a week for 18 weeks. A second liver biopsy was taken for comparison at the end of week 18. Blinded biopsies were scored according to Knodell's histology activity index (HAI), and examined for HBsAg, HBeAg, HBcAg and alpha - SMA by immunohistochemistry. The serum samples corresponding with liver biopsies were collected and HBV DNA, e-antigen were measured. RESULTS: Histological assessment revealed a significant improvement in intralobular inflammation and periportal necrosis after treatment(P<0.01). Fifty-five percent (12/22) patients had a reduction of hepatic necroinflammatory HAI score at the end of 18 weeks of interferon alpha-2b therapy compared to pretreatment values, but periportal inflammation and fibrosis failed to show improvement. HBeAg disappeared from liver tissues in 7 from 13 cases(53.8%)and a significant reduction of activated liver stellate cells was demonstrated in biopsies performed after suspending the interferon treatment(P=0.0004). Serum HBV DNA levels decreased significantly after treatment (P<0.01). The clearance rate of HBeAg was 42.9% after treatment. There was no significant difference between HBeAg positive and negative patients either in liver histological improvements or declining level of serum HBV DNA. CONCLUSIONS: Interferon alpha-2b may decrease the level of serum HBV DNA in the patients with chronic hepatitis B infection, and improve their necroinflammation in liver tissues.

Adult↗
PubMed2001

Circular minidefensins and posttranslational generation of molecular diversity.

We purified two new minidefensins (RTD-2 and RTD-3) from the bone marrow of rhesus monkeys. Both were circular octadecapeptides that contained three intramolecular disulfide bonds and were homologous to RTD-1, a circular (theta) defensin previously described by Tang et al. (Science, 286, 498-502, 1999). However, whereas the 18 residues of RTD-1 represent spliced nonapeptide fragments derived from two different demidefensin precursors, RTD-2 and -3 comprise tandem nonapeptide repeats derived from only one of the RTD-1 precursors. Thus, circular minidefensins are products of a novel posttranslational system that generates effector molecule diversity without commensurate genome expansion. A system wherein two demidefensin genes can produce three circular minidefensins might allow n such genes to produce (n/2)(n+1) peptides.

Amino Acid Sequence↗
PubMed2001

[A comparative study on clinical and pathological diagnosis in patients with chronic viral hepatitis].

OBJECTIVE: To provide some suggestions for revision of "1995's program on prevention and treatment of viral hepatitis", a study on the correlation between clinical and pathological diagnosis of chronic hepatitis was performed. METHODS: The main clinical symptoms, signs, and laboratory data taken from 664 patients with mild, moderate and severe chronic viral hepatitis were analyzed and compared with their corresponding pathological findings. RESULTS: The incidence of symptoms such as fatigue, poor appetite, nausea and flatulence was 51.5% to 91.2% in the order of the severity of hepatopathological damage. Splenomegaly and spider nevus showed a close correlation with the degree of pathological changes, especially with the former the incidence being 25.4%, 35.8% and 41.1% among the mild, moderate and severe groups respectively (P < 0.01). In addition to ALT and other five laboratory parameters listed in the program, a remarkable difference of AST and platelet count was also shown in the three groups. There was a better correlation between laboratory results and pathological findings in mild chronic hepatitis, and each one might attain from 65.4% to 93.6%, but this was not so in moderate except for A/G(53.2%) and in severe except for ALT(30.2%) according to the "1995's program on prevention and treatment of viral hepatitis". CONCLUSIONS: A comprehensive judgment for the diagnosis of chronic viral hepatitis should combine clinical symptoms, signs and laboratory results. Great attention should be paid to the significance of clinical symptoms and splenomegaly. AST and platelet count might be included as diagnostic parameters in the new revised program on prevention and treatment of viral hepatitis.

Adult↗
PubMed2001

Human stem cell model to study signal transduction and molecular regulation mechanisms in CML.

OBJECTIVE: To develop a primary human hematopoietic stem/progenitor cell model for chronic myeloid leukemia (CML) and study signal transduction and molecular regulation mechanisms in CML. METHODS: We developed a human model of p210BCR/ABL positive CML by transducing normal human umbilical cord blood CD34+ cells with a retroviral vector containing the b3a2 bcr/abl cDNA. We also examined whether this model recreated the cellular phenotype of CML by assessing cell adhesion, cell migration, cell proliferation and cell survival. RESULTS: We found that significantly more myeloid colony forming units grew from p210BCR/ABL expressing cells, adhesion of p210BCR/ABL expressing CD34+ cells to fibronectin was decreased but migration over fibronectin was enhanced compared with mock transduced CD34+ cells. In this model, we showed that the presence of p210BCR/ABL leads to elevated levels of p27kip in p210BCR/ABL expressing CD34+ cells. We also showed that multidrug resistance-1 (MDR-1) Pgp was upregulated in the p210BCR/ABL expressing cells which correlates with the expression of p210BCR/ABL. CONCLUSION: This primary human CML model recreates most of the features of CML and provides a useful tool to study signal transduction and downstream molecular regulation drived by the p210BCR/ABL oncogene in normal CD34+ cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Clavaspirin, an antibacterial and haemolytic peptide from Styela clava.

We cloned the precursor of a novel peptide from a cDNA library prepared from pharyngeal tissues of the tunicate, Styela clava. Its sequence predicted a histidine-rich, amidated 23-residue peptide (FLRF(IG)SVIHGIGHLVHHIGVAL-NH2) that we named clavaspirin. A synthetic clavaspirin was prepared and it was found that it killed Gram-positive and Gram-negative bacteria, permeabilized the outer and inner membranes of Escherichia coli, lysed phosphatidylglycerol (POPG) liposomes, and was potently haemolytic towards human and bovine erythrocytes. Each of these activities was performed more effectively at an acidic pH. Circular dichroism measurements of synthetic clavaspirin revealed a largely alpha-helical structure and polarized and residue-specific FTIR spectrometry showed that its association with phospholipid membranes was influenced by pH. Peptides such as clavaspirin may equip tunicate haemocytes to mediate cytotoxicity and participate in antimicrobial defence.

Amino Acid Sequence↗
PubMed2001

[Detection of interleukin-6 in gingival crevicular fluid from active and non-active adult periodontitis sites].

OBJECTIVE: To reveal the relationship between IL-6 and the activity of periodontitis. METHODS: The concentration of IL-6 in gingival crevicular fluid (GCF) was measure by ELISA. Sixty teeth from 39 patients with adult periodontitis were sampled, among which there were 29 teeth in active phase, while the rest were in non-active phase. RESULTS: Significant difference was found in the level of IL-6 in GCF between the active group (10.65 +/- 22.05 ng/ml) and the non-active group (1.73 +/- 0.53 ng/ml, P < 0.05). CONCLUSION: The level of IL-6 in GCF may be a useful indicator of the activity of periodontitis.

Adult↗
PubMed2001

[Interleukin-6 levels in the gingival crevicular fluid before and after periodontal treatment].

OBJECTIVE: The aim of this study therefore is to determine if periodontal scaling and root planning could affect the IL-6 level in the GCF of teeth with periodontitis. METHODS: 12 teeth from 12 patients with severe periodontitis were clinically examined and sampled before therapy. 2 weeks after the periodontal scaling and root planning, the same 12 teeth were examined and sampled again. The IL-6 levels in GCF were detected using ELISA method. There are some evidences that the interleukin-6 (IL-6) levels in the periodontal tissue and gingival crevicular fluid (GCF) of periodontitis sites are significantly higher than that of healthy periodontal sites. RESULTS: The IL-6 levels in GCF from the teeth declined and the periodontal clinical indices of these teeth also apparently dropped down. CONCLUSION: Periodontal treatment, including periodontal scaling and root planning could affect the IL-6 levels in GCF of teeth with periodontitis.

Adult↗
PubMed2001

[Effects of air pollution from burning coal on respiratory diseases in adults].

A cross sectional epidemiological study on the effect of air pollution from burning coal on the occurrence of respiratory symptoms and diseases in adults was carried out in Taiyuan city of Shanxi province. Adult residents above 25 year-old living in three areas with different degrees of pollution were selected. The results showed that the prevalence of respiratory symptoms and diseases increased with the extent of air pollution after age, sex, occupation, smoking, indoor coal-burning and history of diseases were adjusted with Logistic model.

Adult↗
PubMed2001

[Effects of zinc deficiency on the distribution of elements in the tissue of pregnant rats and their fetuses].

The influence of zinc(Zn) deficiency on the distribution of elements in tissues of pregnant rats and their fetuses was investigated. Pregnant Wistar rats were divided into zinc deficiency (ZD), pair-fed(PF), zinc supplement (ZS) and control (C) groups. ZD rats were fed for 21 days a zinc deficient (0.7 mg/kg) diet and other rats were fed a similar diet supplemented with zinc (100 mg/kg). On the 21st day of gestation, blood was drawn from heart, laparotomy was performed, and liver, spleen, kidney, placentas, fetuses were removed for analysing on zinc, copper (Cu), iron (Fe), manganese (Mn) and calcium (Ca). The results showed that the element levels in blood, organs and fetuses from ZD rats were significantly lower than those from ZS and C rats. Furthermore, the levels of Cu, Fe, Mn in blood, liver, spleen, kidney of ZD rats were significantly lower than those of PF rats. It suggests that there are some coordination relationships in intestinal absorption and tissue distribution between Zn and other elements, and the decrease of elements in the body does not mainly result from the reduction of dietary intake caused by zinc deficiency. The Fe content in placentas and Fe, Ca content in fetuses of ZD rats showed a significant increase as compared with those of rats in other groups. There may be a competitive mechanism on the transportation of Zn and Fe in the placenta of rats. In brief, the distribution of minerals in maternal tissues induced by zinc deficiency might be different from those in fetuses.

Animals↗