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Biomedical subjects

Bo Wang

Publications and source records attributed to Bo Wang.

At least 127 records · Page 7Linked to original sources
PubMed2005

[Study of sonochemical degradation of microcystins].

Sonochemical degradation of microcystins (MC) produced by microcystis in water and the influence of various ultrasonic parameters were studied. The results show that microcystins could be effectively degraded in ultrasonic fields. 150 kHz is the best ultrasound frequency for microcystins degradation, and the removal ratio of microcystins reached 70% after 20 min ultrasonic irradiation at 150 kHz and 40 W. Furthermore, ultraviolet irradiation strengthened the ultrasonic degradation of microcystins.

Microcystins↗
PubMed2004

FADD-dependent apoptosis induction in Jurkat leukemia T-cells by the resveratrol analogue, 3,4,5-trihydroxy-trans-stilbene.

The plant-produced compound, resveratrol (3,5,4'-trihydroxy-trans-stilbene, 3,4,5-THS), induces apoptosis in various human leukemia cell types in vitro, and thus appears to be a promising anti-leukemia agent. In this study, we observed that treatment of resveratrol-resistant Jurkat cells with the resveratrol analogue, 3,4,5-trihydroxy-trans-stilbene (3,4,5-THS), rapidly induced extensive apoptosis, indicating that the apoptotic activity of the analogue differed from that of the parental compound resveratrol. Indeed, we found that treatment of Jurkat cells with 3,4,5-THS, unlike treatment with resveratrol, induced activation of caspase-8 and apoptosis by a Fas-associated death domain (FADD) protein-dependent mechanism without involving the known death ligands CD95 ligand (CD95L), tumor necrosis factor alpha (TNFalpha) and TNF-related apoptosis-inducing ligand (TRAIL). Therefore, 3,4,5-THS induced activation of a FADD-dependent apoptotic mechanism that was unresponsive to the parental compound resveratrol. Therefore, the ability of 3,4,5-THS, but not resveratrol, to induce apoptosis demonstrates a structure-associated apoptotic activity of the resveratrol analogue.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Nitric oxide mediates inhibitory effect of leptin on insulin-like growth factor I augmentation of 17beta-estradiol production in human granulosa cells.

In the present study the authors investigated if the inhibitory effect of leptin in the ovary was mediated via nitric oxide (NO) using human granulosa cells (GCs). Human GCs were obtained from preovulatory follicles of women who underwent IVF. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that human GCs expressed mRNA of leptin and mRNA of isoforms of leptin receptor, including one long form and two types of short forms. Exposure of human GCs to leptin at concentrations of 3-30 ng/ml for 60 min dose-dependently increased the fluorescence of 4,5-diaminofluorescein (DAF-2), an NO-sensitive dye. The effect of leptin on DAF-2 fluorescence was inhibited by pretreatment of human GCs with 100 microM nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase (NOS), indicating that the increase in DAF-2 fluorescence properly reflected the intracellular NO production. FSH (1 ng/ ml) and IGF-I (30 ng/ml) stimulated 17beta-estradiol (E2) production in human GCs, respectively. FSH plus IGF-I induced a further increase in E2 production. Leptin did not significantly alter basal or FSH-dependent E2 production, but it inhibited the effect of IGF-I on E2 production and the synergistic effect of IGF-I on FSH-stimulated E2 production. The inhibitory effect of leptin on IGF-I argumentation of E2 production was attenuated by pretreatment of human GCs with 100 microM L-NAME. In conclusion, leptin could induce NO production in human GCs. The inhibitory effect of leptin on IGF-I augmentation of E2 production in human GCs was attenuated by L-NAME, strongly suggesting that NO may mediate the action of leptin in human GCs.

Cells, Cultured↗
PubMed2004

Design, synthesis, and biological evaluation of novel 4-alkylamino-1-hydroxymethylimidazo[1,2-a]quinoxalines as adenosine A(1) receptor antagonists.

A series of 4-alkylamino-1-hydroxymethylimidazo[1,2-a]quinoxalines have been synthesized and evaluated for their adenosine A(1) receptor inhibitory activity in the radioligand binding assays. The compounds were tested for the inhibition percent (IP) and the affinity toward A(1)AR (K(i)) that IP were more than 90% in the nanomolar range. 4-Cyclopentylamino-7,8-dichloro-1-hydroxymethylimidazo[1,2-a]quinoxaline 18 is the most potent compound in this series, having K(i)=7nM, which is remarkably higher than that of IRFI-165 (K(i)=48). 1-Hydroxymethyl groups of the tricyclic heteroarmatic compounds displayed the potent affinities toward A(1)AR.

Adenosine A1 Receptor Antagonists↗
PubMed2004

Effect of structure of PEO-PPO-PEO copolymers on reverse micelle formation induced by compressed CO2.

The micellization of PEO-PPO-PEO block copolymers in p-xylene has been studied in the presence of CO2. With the application of CO2, some copolymers with suitable molecular weights and EO ratios can form reverse micelles with critical micellization pressure up to 5.8 MPa. For the copolymers with the same length of PO block, higher EO ratios facilitate reverse micelle formation. For the copolymers with the same composition, higher molecular weight is favorable to form reverse micelles. With the suitable composition and molecular weight, the critical micelle pressure (CMP) of copolymers decreases with the increase in the lengths of PEO and PPO blocks due to the hydrophilic and folding effects, respectively. Both the EO ratios and the molecular weights are important for the formation of reverse micelle. The reverse micelle solution can solubilize water with W0 (molar ratio of water to EO segment) up to 3.3.

Journal Article↗
PubMed2004

Construction and selection of subtracted cDNA library of mouse hepatocarcinoma cell lines with different lymphatic metastasis potential.

AIM: In order to elucidate the molecular mechanism of lymphatic metastasis of hepatocarcinoma, we detected the difference of gene expression between mouse hepatocarcinoma cell lines Hca-F and Hca-P with different lymphatic metastasis potential. METHODS: cDNA of Hca-F cells was used as a tester and cDNA of Hca-P cells was used as a driver. cDNAs highly expressed in Hca-F cells were isolated by the suppression subtractive hybridization (SSH) method. The isolated cDNA was cloned into T/A cloning vector. The ligation products were transformed into DH5alpha competent cells. Individual clones were randomly selected and used for PCR amplification. Vector DNA from positive clones was isolated for sequencing. RESULTS: There were 800 positive clones in amplified subtracted cDNA library. Random analysis of 160 clones with PCR showed that 95% of the clones contained 100-700 bp inserts. Analysis of 20 sequenced cDNA clones randomly picked from the SSH library revealed 4 known genes (mouse heat shock protein 84 ku, DNA helicase, ribosomal protein S13, ethanol induced 6 gene) and 3 expressed sequence tags (ESTs). Four cDNAs showed no homology and presumably represent novel genes. CONCLUSION: A subtracted cDNA library of differentially expressed genes in mouse heptocarcinoma cell lines with different lymphatic metastasis potential was successfully constructed with SSH and T/A cloning techniques. The library is efficient and lays a solid foundation for searching new lymphatic metastasis related genes. The expression of mouse heat shock protein gene, DNA helicase and other 4 novel gene may be different between mouse heptocarcinoma cell lines with different lymphatic metastasis potential.

Animals↗
PubMed2004

A novel process for inking the stamp with biomacromolecule solution used in reactive microcontact printing.

This paper describes a novel process for inking the stamp with biomacromolecule solution used in reactive microcontact printing. The stamp was first coated with biomacromolecule solution such as bovine serum albumin (BSA) solution for 20 min, and then dried by soft nitrogen flow. After cooling the stamp below the dew point for 1 min and incubated at room temperature for 10 s, a thin layer of condensed water was formed on the stamp surface. Then, an aldehyde functionalized glass slide was pressed immediately onto the stamp for certain time, yielding the covalently patterning of the biomacromolecules on the aldehyde-containing surface. A notable feature of this process is that the biomacromolecule solution can be inked onto the stamp at a controlled state, neither too "dry" nor too "wet". As a result, the covalently grafting reaction can occur at a comparable speed with those in solution, while avoiding the contamination caused by dispersal of excessive solvent.

Biopolymers↗
PubMed2004

Human amyloidogenic light chains directly impair cardiomyocyte function through an increase in cellular oxidant stress.

Primary amyloidosis is a systemic disorder characterized by the clonal production and tissue deposition of immunoglobulin light chain (LC) proteins. Congestive heart failure remains the greatest cause of death in primary amyloidosis, due to the development of a rapidly progressive amyloid cardiomyopathy. Amyloid cardiomyopathy is largely unresponsive to current heart failure therapies, and is associated with a median survival of less than 6 months and a 5-year survival of less than 10%. The mechanisms underlying this disorder, however, remain unknown. In this report, we demonstrate that physiological levels of human amyloid LC proteins, isolated from patients with amyloid cardiomyopathy (cardiac-LC), specifically alter cellular redox state in isolated cardiomyocytes, marked by an increase in intracellular reactive oxygen species and upregulation of the redox-sensitive protein, heme oxygenase-1. In contrast, vehicle or control LC proteins isolated from patients without cardiac involvement did not alter cardiomyocyte redox status. Oxidant stress imposed by cardiac-LC proteins further resulted in direct impairment of cardiomyocyte contractility and relaxation, associated with alterations in intracellular calcium handling. Cardiomyocyte dysfunction induced by cardiac-LC proteins was independent of neurohormonal stimulants, vascular factors, or extracellular fibril deposition, and was prevented through treatment with a superoxide dismutase/catalase mimetic. This study suggests that cardiac dysfunction in amyloid cardiomyopathy is directly mediated by LC protein-induced cardiomyocyte oxidant stress and alterations in cellular redox status, independent of fibril deposition. Antioxidant therapies or treatment strategies aimed at eliminating circulating LC proteins may therefore be beneficial in the treatment of this fatal disease.

Amyloid↗
PubMed2004

Increased myocardial dysfunction after ischemia-reperfusion in mice lacking glucose-6-phosphate dehydrogenase.

BACKGROUND: Free radical injury contributes to cardiac dysfunction during ischemia-reperfusion. Detoxification of free radicals requires maintenance of reduced glutathione (GSH) by NADPH. The principal mechanism responsible for generating NADPH and maintaining GSH during periods of myocardial ischemia-reperfusion remains unknown. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the pentose phosphate pathway, generates NADPH in a reaction linked to the de novo production of ribose. We therefore hypothesized that G6PD is essential for maintaining GSH levels and protecting the heart during ischemia-reperfusion injury. METHODS AND RESULTS: Susceptibility to myocardial ischemia-reperfusion injury was determined in Langendorff-perfused hearts isolated from wild-type mice (WT) and mice lacking G6PD (G6PD(def)) (20% of WT myocardial G6PD activity). During global zero-flow ischemia, cardiac function was similar between WT and G6PD(def) hearts. On reperfusion, however, cardiac relaxation and contractile performance were greatly impaired in G6PD(def) myocardium, as demonstrated by elevated end-diastolic pressures and decreased percent recovery of developed pressure relative to WT hearts. Contractile dysfunction in G6PD(def) hearts was associated with depletion of total glutathione stores and impaired generation of GSH from its oxidized form. Increased ischemia-reperfusion injury in G6PD(def) hearts was reversed by treatment with the antioxidant MnTMPyP but unaffected by supplementation of ribose stores. CONCLUSIONS: These results demonstrate that G6PD is an essential myocardial antioxidant enzyme, required for maintaining cellular glutathione levels and protecting against oxidative stress-induced cardiac dysfunction during ischemia-reperfusion.

Animals↗
PubMed2004

Effects of a community-based sex education and reproductive health service program on contraceptive use of unmarried youths in Shanghai.

PURPOSE: To evaluate the effectiveness of a youth-friendly intervention in promoting one safe sex behavior-contraception and condom use among unmarried young people aged 15-24 years in Shanghai, China. METHODS: The study was conducted in two towns of a suburban area of Shanghai (one as the intervention and the other as the control), with comparable socio-cultural-economic and demographic characteristics. The intervention intended to build awareness and offer counseling and services related to sexuality and reproduction among unmarried youths, in addition to the routine program activities, which were exclusively provided in the control site. Baseline surveys were conducted in both sites before the implementation of the intervention, and similar surveys were conducted in both sites 20 months after the intervention had been initiated to test the feasibility and effectiveness of the intervention. In total, 1220 unmarried young people from the intervention site and 1007 from the control site, including 1304 out-of-school youths and 923 high school students, were recruited, and about 92% of them were successfully followed up. Four main measures were examined (i.e., ever contraceptive use, current regular contraceptive use, ever condom use, and contraceptive use at onset of sexual intercourse-if it occurred during the course of the intervention). The reasons for nonuse of contraceptives, the status of joint decision on contraception and the first method used were also assessed. Data were analyzed using Logistic regression models with dichotomous measures of contraceptive use and Generalized Estimating Equations (GEEs) with repeated measures. RESULTS: At baseline, there was no statistical difference in contraceptive use between the intervention and control groups. After intervention, the proportions reporting regular contraceptive use and condom use in the intervention group were much higher than that in the control group (p <.001). A group x time interaction effect (p <.0001) was found for regular contraceptive use and ever condom use. Logistic regression analysis with dichotomous measures of contraceptive use and GEEs with repeated measures showed similar results. The regular contraceptive use and ever condom use were correlated with subject's occupation and family economic status, respectively. After adjusting for demographic factors, the subjects from the intervention group were 14.58 (OR) times as likely to use contraceptives at onset of intercourse as those from the control group (95%CI: 8.55-24.87, p <.0001). Similar results were found for both females and males. CONCLUSIONS: A multifaceted intervention program that provided information and skills, as well as counseling and services, appears to have positive influences on contraceptive practice and condom use among unmarried young females and males in suburban Shanghai.

Adolescent↗
PubMed2004

Fusarium species and Fusarium wilt pathogens associated with native Gossypium populations in Australia.

Fusarium isolates were extracted from stems and rhizosphere soils of 79 populations of four Gossypium species native to two regions of inland Australia in 2001. Six Fusarium species were isolated from 31 (3%) of the 919 stem samples. F. semitectum was predominant, occurring mostly in G. bickii populations and accounting for 81% of the isolates recovered. Twenty Fusarium species were isolated from 68 (87%) of the 78 composite soil samples, with F. solani (71%), F. compactum (8%), F. oxysporum (5%), F. graminearum (3%), and F. crookwellense (3%) being the most prevalent. Significant differences in the relative densities indicated that F. solani was more common in the soil from G. sturtianum populations than from G. bickii populations, and that F. crookwellense was more common in South Australian soils than in Queensland and Northern Territory soils. Fusarium oxysporum had a relatively greater relative density in the rhizosphere soils of G. australe plants than in that of sympatrically growing G. sturtianum plants. Fifteen (17%) of the 89 F. oxrysporum isolates produced typical Fusarium wilt symptoms on cultivated cotton (G. hirsutum cv. 'Siokra 1-4'), therefore they were classified as wild Fov. Soil samples collected from G. sturtianum populations in the Arkaroola-Leigh Creek region in South Australia had the highest incidence of wild Fov (24%). Two wild Fov isolates were similar in virulence to a cotton field Fov isolate in the glasshouse experiments, indicating that they could incite Fusarium wilt disease in cotton fields. The presence of wild Fov in native Gossypium populations suggests that the Fov occurring in Australian cotton fields may be of indigenous origins.

Fusarium↗
PubMed2004

Termitomyces bulborhizus sp. nov. from China, with a key to allied species.

The new species, Termitomyces bulborhizus, is described from south-west China. The stipe of the basidiome is swollen into a prominent bulbous base at ground level, and this, together with the floccules on the stipe surface, distinguishes this species within the genus. T. bulborhizus is compared with closely related species, including three originally described from China, and a key to T. bulborhizus and related species is provided.

Agaricales↗
PubMed2004

Biochemical properties of V91G calmodulin: A calmodulin point mutation that deregulates muscle contraction in Drosophila.

A mutation (Cam7) to the single endogenous calmodulin gene of Drosophila generates a mutant protein with valine 91 changed to glycine (V91G D-CaM). This mutation produces a unique pupal lethal phenotype distinct from that of a null mutation. Genetic studies indicate that the phenotype reflects deregulation of calcium fluxes within the larval muscles, leading to hypercontraction followed by muscle failure. We investigated the biochemical properties of V91G D-CaM. The effects of the mutation on free CaM are minor: Calcium binding, and overall secondary and tertiary structure are indistinguishable from those of wild type. A slight destabilization of the C-terminal domain is detectable in the calcium-free (apo-) form, and the calcium-bound (holo-) form has a somewhat lower surface hydrophobicity. These findings reinforce the indications from the in vivo work that interaction with a specific CaM target(s) underlies the mutant defects. In particular, defective regulation of ryanodine receptor (RyR) channels was indicated by genetic interaction analysis. Studies described here establish that the putative CaM binding region of the Drosophila RyR (D-RyR) binds wild-type D-CaM comparably to the equivalent CaM-RyR interactions seen for the mammalian skeletal muscle RyR channel isoform (RYR1). The V91G mutation weakens the interaction of both apo- and holo-D-CaM with this binding region, and decreases the enhancement of the calcium-binding affinity of CaM that is detectable in the presence of the RyR target peptide. The predicted functional consequences of these changes are consonant with the in vivo phenotype, and indicate that D-RyR is one, if not the major, target affected by the V91G mutation in CaM.

Animals↗
PubMed2004

[Study on the replication of Hepatitis B Virus in primary hepatocytes from heterogenous species].

OBJECTIVES: By studying the possibility and degree of the replication and expression of human hepatitis B virus (HBV) genes in normal liver cells from heterogenous species, such as primary duck hepatocytes (PDH) and primary rat hepatocytes (PRH), to investigate the species-specificity of HBV infection and replication. METHODS: PDH and PRH isolated by in situ perfusion with low concentration collagenase were transfected with complete HBV genome by electroporation (transfection group, about 1.19 10(12) copies of linear HBV DNA/1 10(7) PRH/PDH). From 1 day to 15 days after transfection, HBsAg and HBeAg in the supernatants and lysates of PRH/PDH were measured with IMX System, HBcAg was assayed with western blotting, Immunol dot blotting and Immunocytochemistry. Moreover, HBV S-mRNA and X-mRNA were tested with RT-PCR. Meanwhile, replicative intermediates of HBV DNA were analyzed by Southern blotting and Dot blotting. PRH/PDH electroporated only was used as control group. RESULTS: HBsAg in the lysates of transfected PDH group were 15.24 (1day), 14.55 (3 days) and 5.13 ( 5 days; P/N values, positive>or=2.1), HBeAg all was negative (<2.1), and both were negative in the supernatants of transfected group. Viral antigen production in transfected rat hepatocytes: HBsAg in the lysates of transfected hepatocytes was positive, P/N values ranging from 2.17 to 93.41, The average P/N values was 14.74+/-31.82, and could be maintained for 15 days after transfection. Whereas, HBsAg in the supernatants of transfected group was only found positive on 1 day after transfection, which P/N value was 6.66. HBeAg and HBcAg in the lysates of PRH of transfection group were positive during the first 3 days following transfection, P/N values was around 2.8. The total amount of HBV DNA in the transfected PDH and PRH groups was strongly positive by dot blotting, whereas that of the control group was negative. Southern blot analysis of intracellular total HBV DNA indicated that there were relaxed circular (RC), covalently closed circular (ccc) and single-stranded (SS) HBV DNA replicative intermediates in the transfected PDH and PRH groups, there was no integrated HBV DNA in the cellular genome. Control groups were negative at all. CONCLUSION: Expression of HBV genes and production can occur in hepatocytes from nonmammalian species or mammalian species, which strongly supports the idea that replication of HBV has no critical species-specificity, and yet it depends on the endoenvironment of hepatocyte.

Animals↗
PubMed2004

[Clinical analysis of 5 cases with acute intravascular hemolysis caused by puerarin].

OBJECTIVE: To explore the clinical characteristics of acute intravascular hemolysis caused by puerarin so as to help our prevention, diagnosis and treatment. METHODS: Analysis of 5 cases of acute intravascular hemolysis caused by puerarin was made and literature review conducted. RESULTS: All patients had the history of administering puerarin, with the pre-symptoms of acute hemolysis; the clinical characteristics of acute intravascular hemolysis were observed:sudden attacks of lumber and abdominal pain, chill, fever dyspnea, temporary conciousness loss, dark urine or hematuria, low hemoglobin, high reticular red blood cell, positive of Coombs' test. CONCLUSION: When sudden attacks of the above symptoms appear, the acute intravascular hemolysis should be taken into consideration first and the giving of the puerarin intravenously be immediately stopped Active and proper treatment should be made.

Adult↗
PubMed2004

[The analysis of HLA-B15 and B40 antigen polymorphism in Xi'an].

AIM: To study the distribution character of HLA-B15 and B40 in Xi'an population. METHODS: PCR-SSP and reverse PCR-SSOP reaction pattern were used to type the HLA-B15 and B40 alleles of 3 601 blood samples in Xi an. RESULTS: HLA-B15 and B40 gene frequencies were 0.1483 and 0.1414, respectively, among 3 601 blood samples from Xi'an population which take up 57.91% in HLA-B alleles. CONCLUSION: The distribution character of HLA-B15 and B40 alleles in Xi'an population were different compared with other populations.

Black or African American↗
PubMed2004

CDNA cloning of a short isoform of human liver NADP (H) -dependent retinol dehydrogenase/reductase and analysis of its characteristics.

In this report we found a new short PCR product when we amplified a 635 bp of NRDR fragment by RT-PCR. With 3'-Race and 5'-Race,we obtained two full-length cDNA sequences from human liver tissue,one 1 261 bp NRDR cDNA,another 1 003 bp NRDR isoform (NRDRiso,GenBank accession number:AY071856). The NRDR gene comprises eight exons and seven introns. The NRDRiso cDNA is produced by alternative splicing of NRDR cDNA, with the removal of 4, 5, 6 exons composed of consecutive 258 bp. The open reading frames of the NRDRiso cDNA predict a single polypeptide of 174 amino acids with the calculated minimum molecular mass of 18.6 kDa.

Alcohol Oxidoreductases↗