Biomedical subjects

P Zhou

Publications and source records attributed to P Zhou.

At least 55 records · Page 3Linked to original sources

PubMed2001

Identification of molecular genetic markers tightly linked to downy mildew resistant genes in grape.

Bulk segregant analysis (BSA), randomly amplified polymorphic DNA (RAPD) and sequence characterized amplified region (SCAR) methods were used to tag the downy mildew-resistant genes of grape with molecular markers. Parents and their 60 individuals of an F1 progeny resulting from a cross 88-110 between 83-4-96 (Vitis quinquangularis, downy mildew-resistant) and Muscat Rose (V. vinifera, downy mildew-susceptible), three F2 progenies resulting from three crosses of self-cross and inter-cross of 88-110 F1 seedlings, as well as another interspecific F1 hybrids of 88-84 cross [Xun-3 (V. quinquangularis, downy mildew-resistant) x Ugni Blanc (V. vinifera, downy mildew-susceptible)] and the wild grapes native to China were used for the study. Among 280 Operon primers, 160 gave distinct band patterns. One RAPD marker OPO06-1500 was tightly linked to a major gene resistant to Plasmopara viticola (RPv-1). Based on Mapmaker software analysis, the map distance between RPv-1 and OPO06-1500 was 1.7 cM. Marker OPO06-1500 was cloned and sequenced. According to the sequence, two specific primers were designed to amplify all plant materials. RAPD marker was converted into SCAR marker (SCO06-1500). One distinct single band only in resistant plants was amplified, whose size was the same as that of the RAPD marker. The SCAR marker's popularity was confirmed, and it could be used for the identification of hybrid resistant to P. viticola and will be potentially useful in the development of new resistant grape cultivars.

Genetic Markers↗

PubMed2001

Inhibition of hematopoietic progenitor cell proliferation by ethanol in human immunodeficiency virus type 1 tat-expressing transgenic mice.

BACKGROUND: A number of hematological abnormalities are associated with both human immunodeficiency virus type 1 (HIV-1) infection and alcohol abuse. There is little information on how alcohol abuse might further influence the survival and growth of hematopoietic progenitors in HIV-infected individuals in the presence of immune system abnormalities and anti-HIV drugs. Because there is evidence that viral transactivator Tat itself can induce hematopoietic suppression, in this study we examined the role of ethanol as a cofactor in transgenic mice that expressed HIV-1 Tat protein. METHODS: Tat transgenic mice and nontransgenic littermates were given ethanol (20% v/v) and the anti-HIV drug 3'-azido-3'-deoxythymidine (AZT; 1 mg/ml) in drinking water. Immunosuppression in mice was induced by weekly intraperitoneal injections of anti-CD4 antibody. Hematopoiesis was examined by erythroid colony forming unit (CFU-E) and granulocyte/macrophage colony-forming unit (CFU-GM) assays of the bone marrow progenitor cells. RESULTS: Administration of ethanol for 7 weeks resulted in a 50% decrease in the proliferative capacity of CFU-E- and CFU-GM-derived progenitors from transgenic mice compared with that of ethanol-treated nontransgenic controls. Similar decreases also were observed in transgenic mice treated with AZT or a combination of AZT and ethanol. Furthermore, ethanol and AZT were significantly more toxic to the granulopoietic progenitors (40-50% inhibition) than to the erythropoietic progenitors (10-20% inhibition) in Tat transgenic mice. Although a 10 day exposure of Tat transgenic and nontransgenic mice to a combination of ethanol and AZT had no suppressive effect on the erythropoietic and granulopoietic progenitor cells, there was a marked decrease (40-60%) in CFU-GM in mice made immunodeficient by CD4+ T-lymphocyte depletion. The ethanol-treated Tat transgenic mice but not the nontransgenic litter-mates also showed a significant decrease (25%) in CFU-GM. CONCLUSION: Our in vivo study strongly suggests that ethanol ingestion in HIV-1-infected individuals, particularly those on antiretroviral drugs, might increase bone marrow toxicity and contribute to HIV-1-associated hematopoietic impairment.

Animals↗

PubMed2001

[Establishment of suc2 signal sequence trap system].

The secretion of proteins depends on the signal peptide located to the N-terminal of the protein precursor. We established a genetic system in yeast to screen cDNA library for the signal peptide encoding sequences. To do it, we mutated genomic suc2 gene (encoding yeast invertase) of EGY48 by one-step gene disruption method, and got yeast cell lines without invertase expression (EGY48-delta suc). To get vector for library screening, we inserted suc2 gene encoding mature peptide of invertase downstream to yeast promoter P-ADH1, and multiple cloning sites for insertion of library is between suc2 and P-ADH1. EGY48-delta suc transformed with the vector can grow on the medium with glucose as carbon source, but not on the medium with raffinose. Signal peptide of suc2 and alpha chain of human interleukin-2 was fused in frame to suc2 gene, then the two resulting vectors were transformed into EGY48-delta suc, all the transformants can grow in the medium with either raffinose or glucose as carbon source. Hence, the system established here can discern cDNA encoding signal peptide from the one not encoding signal peptide.

Amino Acid Sequence↗

PubMed2001

[Identification of seeds of Cuscuta australis and C. chinensis by TLC and HPLC].

Identification of seeds of Cuscuta australis R. Br. and C. chinensis Lam. was carried out by TLC and HPLC. Polyamide membrane was used as stationary phase, MeOH-HOAc-H2O and CHCl3-MeOH-HOAc were used as mobile phase for TLC. For HPLC, Hypersil-ODS column was used; the mobile phase was MeOH-0.025 M H3PO4; the flow rate was 1.0 ml.min-1; detection wavelength was 360 nm; and column temperature was 40 degrees C. Both methods represented significant identification characteristics, and were simple, accurate and reproducible.

Chromatography, High Pressure Liquid↗

PubMed2001

[Distribution of 5'-nucleotidase activity in greater omentum of rats].

The aim of the present study is to demonstrate the cellular basis of 5'-nucleotidase (5'-Nase) activity in the greater omentum of rats. Enzyme histochemistry for 5'-Nase showed that lymphatic vessels in the omentum as well as lymphocytes in the milky spots were positively stained. Electron microscopic observation revealed-5'-Nase activity at the luminal surface of the lymphatic endothelial cells, pinocytotic vesicles in the endothelial cells and the surface of fibroblasts located at the intercellular space of adipose cells. Fibroblasts extended long cytoplasmic processes toward adipose cells and inflammatory cells. These findings suggest that lymphatic endothelial cells as well as fibroblasts in the omentum may play an important role in regulation of metabolism and immune mechanisms in the greater omentum by supplying adenosin.

5'-Nucleotidase↗

PubMed2001

[New advances in research of combined pollution].

Combined pollution has become one of the important directions of environmental science at present. In this paper, new advances of studies on combined pollution were summarized. The studies of inorganic combined pollution, inorganic-organic combined pollution and organic combined pollution were reviewed. The mechanisms of combined pollution were approached from chemistry, physiology, enzymology, cytology and molecular biology. Then some problems and developing aspects on the research of combined pollution were put forward.

Environmental Pollutants↗

PubMed2001

[Study on reclassification of extremely thermoacidophilic archaea strain S5].

The further study on thermoacidophilic archaea strain S5, with has been identified as Sulfosphaerellus thermoacidophilum gen.nov.,sp.nov, has shown it was able to grow facultatively aerobically by means of two sulfur-metabolizing modes of chemolithotrophy which is the characteristic of Acidianus. And the 16SrRNA gene of strain S5 was amplified, cloned and sequenced, a phylogenetic tree was constructed on the 16SrRNA gene sequences. The tree clearly indicated that strain S5 formed the same lineage with Acidianus brierleyi. Thus strain S5 should be the member of Acidianus. However, there are only 44%, 22% and 23% genomic DNA similarity between S5 and A. brierleyi. A. infernus and A. ambivalens, respectively. And the G + C content of S5 DNA is 38%, which is 5% ~ 7% higher than the reported G + C contents of the other Acidianus species (31% or 32.7%) . In addition, strain S5 is a strictly chemolithoautotrophs, which is obviously different from facultative chemolithotrophs of A brierleyi. Based on the observed differences, strain S5 represents a new species within the genus Acidianus. A new species name, Acidianus tengchongenses, was proposed for it. The type strain is designated S5.

Acidianus↗

PubMed2001

[Fermentation conditions for production of alkaline elastase by alkaliphilic Bacillus XE22-4-1].

A extracellular alkaline elastase producing bacterial strain Bacillus XE22-4-1, with the optimum pH of 10.0 for its growth, was isolated and screened from alkali lake of Tibet. 2% glucose and 0.25% yeast extract are respectively the appropriate carbon and nitrogen source on elastase production. Soymeal can promote elastase production. The fermentation conditions in a 2 L stirred tank were investigated. The results have revealed that the dissolved oxygen is the most effective factor on elastase production. The maximum elastolytic activity reached 266 u/mL among 48 hours of fermentation by combination of enhancing aeration and changing the mixing speed.

Bacillus↗

PubMed2001

[Identification and cloning of partial mbh2 gene cluster of hyperthermophile Aquifex pyrophilus].

A 0.8 kb fragment of mbhS2 gene of Aquifex pyrophilus was obtained by PCR with designed primers basing mbhS2 gene of A. aeolicus. It showed 85% homology with the corresponding region of A. aeolicus. Using it as probe, a 5.0 kb Nco I fragment was fished out from the partial genomic library of A. pyrophilus. Then this fragment was cloned, subcloned and sequenced. The result revealed that the fragment contains the full length gene for the mbhS2, the gene orf1 and the first 366 bp of orf2. Comparison with mbhS2 and orf963 of A. aeolicus shows 81% and 60% homologies in amino acid sequence, respectively.

Amino Acid Sequence↗

PubMed2001

[Serapharmacological effect of kangxian ruangan granula on the proliferation of hepatic stellate cells].

OBJECTIVE: To investigate the antifibrotic mechanism of kangxian ruangan granula (KXRGG) at cellular level. METHOD: HSC were isolated from the normal rats by enzyme digestion and density gradient centrifugation, cultured, identified and subcultured. The medicated sera were prepared to incubated with the subcultured HSC. Sodium chloride sera and colchicines sera were taken as control groups. HSC viability was observed by 3H-proline; cell proliferation was measured with 3H-TdR incorporation and MTT colorimetric assay. RESULT: KXRGG medicated serum had no effect on the cellular shape and elevated 3H-proline incorporation (P < 0.01). Drug serum obviously inhibited 3H-TdR incorporation and MTT transformation (P < 0.01), and the latter had a drug concentration-dependent tendency. CONCLUSIONS: KXRGG can elevate cellular viability and has no toxic effect. The formula can inhibit the proliferation of HSC, which may be one of the cellular mechanisms of its antifibrotic action.

Animals↗

PubMed2000

Cloning and heterologous expression of a sulfur oxygenase/reductase gene from the thermoacidophilic archaeon Acidianus sp. S5 in Escherichia coli.

A thermoacidophilic, obligately chemolithotrophic, facultatively aerobic archaebacterium, Acidianus sp. S5, was isolated from acidothermal springs in southwest China. The sulfur oxygenase/reductase (SOR) gene of Acidianus sp. S5 was cloned and expressed in Escherichia coli. Several primers were designed and successfully applied for detection and cloning of the sor gene. A 3.7-kb EcoRI fragment containing the sor gene and three neighboring open reading frames was sequenced. Sequence analysis indicated that the sor gene of Acidianus sp. S5 showed 81% identity to the sor gene of Acidianus ambivalens. E. coli cells carrying the sor gene on pBV220SOR were able to overproduce SOR upon a temperature shift from 30 to 42 degrees C. SOR produced in E. coli catalyzes the oxidation of elemental sulfur and concomitant production of sulfite, thiosulfate and hydrogen sulfide. The recombinant enzyme exhibits the same catalytic properties as the one from Acidianus S5.

Amino Acid Sequence↗

PubMed2000

Role of STAT4 and STAT6 signaling in allograft rejection and CTLA4-Ig-mediated tolerance.

STAT4(-/-) mice have impaired type 1 T cell differentiation, whereas STAT6(-/-) mice fail to generate type 2 responses. The role of type 1 and type 2 T cell differentiation in acute cardiac allograft rejection and in the induction of tolerance was examined in wild-type, STAT4(-/-), and STAT6(-/-) recipients. All recipients rejected the grafts promptly. Analysis of in situ cytokine gene expression in the allografts confirmed decreased levels of IFN-gamma in STAT4(-/-) recipients and undetectable levels of IL-4 and IL-5 in STAT6(-/-) mice. Blockade of the CD28/B7 costimulatory pathway prolonged cardiac graft survival for >100 days in 100% of wild-type and STAT4(-/-) mice. However, 14% of CTLA4-Ig-treated STAT6(-/-) mice rejected their grafts between 20 and 100 days. Moreover, of those animals followed past 100 days, 60% of the STAT6(-/-) mice rejected their grafts. Splenocytes harvested on day 145 posttransplant from CTLA4-Ig-treated rejecting STAT6(-/-) recipients were transfused into syngeneic SCID mice transplanted with donor or third party cardiac allografts. Both donor and third party grafts were rejected, indicating that the initial graft loss may be due to an immunological rejection. In contrast, when splenocytes from CTLA4-Ig-treated wild-type or nonrejecting STAT6(-/-) mice were transferred into SCID recipients, donor allografts were accepted, but third party hearts were rejected. Thus, long-term prolongation of cardiac allograft survival by CTLA4-Ig is STAT4-independent but, at least in part, STAT6-dependent. These data suggest that the balance of type 1 and type 2 T lymphocyte differentiation is not critical for acute rejection but influences the robust tolerance induced by CD28/B7 blockade in this model.

Abatacept↗

PubMed2000

[The study on serological epidemiology of Helicobacter pylori infection in medical staffs].

Serum anti- Helicobacter pylori (Hp) IgG was determined using ELISA in 633 medical staffs and 85 non-medical staffs(as controls) in order to know the prevalence of Hp infection. The results showed that Hp infection rate in medical staffs was significantly higher than that in non-medical staffs(P < 0.05). Among the medical staffs, the highest prevalence of Hp infection was found in gastroenterologists and dental doctors(P < 0.05). Also, Hp infection was significantly higher in subjects with dyspeptic symptoms than those without(P < 0.01). It is concluded that medical staffs, especially gastroenterologists and dental doctors, have occupational risk for Hp infection.

Adult↗

PubMed2000

Exon skipping in Mcl-1 results in a bcl-2 homology domain 3 only gene product that promotes cell death.

Mcl-1 is a member of the Bcl-2 family that is regulated transcriptionally and post-transcriptionally, with expression of the full-length Mcl-1-encoded gene product resulting in enhanced cell survival. As reported here, the human Mcl-1 gene can also undergo differential splicing, which yields an internally deleted, death-inducing gene product, Mcl-1(s/Delta)(TM). Whereas full-length Mcl-1 derives from three coding exons (instead of the two present in Bcl-2 and other anti-apoptotic members of this family), the Mcl-1(s/Delta)(TM) splice variant results from the joining of the first and third exons with skipping of the central exon. Because of the skipped exon and a shift in the reading frame downstream, the Bcl-2 homology domain (BH3) remains intact, whereas the BH1-, BH2-, and transmembrane-encoding domains do not. Mcl-1(s/Delta)(TM) thus has features similar to BH3 only, pro-apoptotic Bcl-2 family members and, accordingly, was found to promote cell death. In addition to a variety of other types of regulation, the Mcl-1 gene appears ideally designed for the generation of either a Bcl-2-like viability promoting or, as reported here, a BH3 only death-inducing gene product.

Amino Acid Sequence↗

PubMed2000

Absence of host B7 expression is sufficient for long-term murine vascularized heart allograft survival.

CD28 antagonists have been shown to promote long-term graft survival and induce donor-specific tolerance. In this study, the role of CD28/B7 costimulation and the relative importance of host versus donor B7 expression in allograft rejection was assessed in a murine abdominal vascularized heterotopic heart transplant model. Wild-type, CD28-deficient, or B7-1/B7-2-deficient C57BL/6 (B6) mice were grafted with allogeneic wild type or B7-1/B7-2-deficient hearts. The results demonstrate allogeneic heart grafts survive long-term in mCTLA4Ig-treated B6 and untreated B7-1/B7-2-deficient B6 recipients but not CD28KO B6 mice. B7-1/B7-2KO B6 recipients treated with anti-CD28 (PV-1) or recombinant human IL-2 rejected the heart transplants indicating that these mice are immunologically competent to reject grafts if costimulatory signals are supplied or bypassed. Finally, there was no difference in rejection between normal animals transplanted with wild-type versus B7-1/B7-2-deficient hearts. These results support a critical role for B7-expressing host antigen presenting cells in the rejection of heart allografts in mice and differences among B7KO and CD28KO animals.

Animals↗

PubMed2000

Blockade of U50488H on sodium currents in acutely isolated mice hippocampal CA3 pyramidal neurons.

The effect of opioid agonist U50488H on Na(+) currents was examined in freshly dissociated hippocampal neurons of mice using the whole-cell patch clamp technique. U50488H (1-100 microM) caused a concentration dependent reversible inhibition of the voltage-activated sodium currents. IC50 of 15.5 microM and Hill constant of 1.4 were calculated respectively. The inhibitory actions of U50488H on I(Na) were still observed in the presence of 30 microM naloxone. Moreover, under the action of U50488H, repetitive stimulation induced further inhibition which was frequency-dependent. The activation curve did not change before and after application of 10 microM U50488H. However, after exposure to 10 microM U50488H and repetitive depolarizing at 10 Hz, frequency-dependent inhibition occurred, and a mean shift of half-activation membrane potential by +20 mV could be induced. The inactivation curve was significantly changed toward negative membrane potential with 10 microM U50488H, and further negative shift was observed after repetitive depolarizing at 10 Hz. Our results indicate that U50488H could directly inhibit neuronal Na(+) currents without involvement in the activation of kappa-opioid receptors.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

PubMed2000

Dot-immunobinding assay using indirect photoacoustic measurement.

Dot-immunobinding assay of hepatitis B surface antigen (HBsAg) was performed by a conventionally dot-ELISA technique with 4-chloro-1-naphthol staining, and the quantitative results were measured by an indirect photoacoustic method. In this method, a 2-mW helium-neon laser was applied to provide the excitation beam, the blue spots on the membrane were detected in a piezoelectric transducer-based photoacoustic cell. The operational conditions of measurement were optimized. A significant difference from the negative human serum was obtained for 50 pg in HBsAg detection. The method proposed provides a sensitive quantitative technique for dot-immunobinding assay.

Coloring Agents↗

PubMed2000

Coumarins and bicoumarin from Ferula sumbul: anti-HIV activity and inhibition of cytokine release.

The methanol extract of the dried roots of Ferula sumbul afforded two furanocoumarin esters, fesumtuorin A, B, one bicoumarin, fesumtuorin C, five spirobicoumarins, fesumtuorin D, E, F, G and H, along with nineteen known coumarins. Their structures were established on the basis of spectroscopic studies. Some of the isolated compounds showed anti-HIV activity and very weak inhibition of cytokine release.

Anti-HIV Agents↗