PubMed Health⌕ Search

Biomedical subjects

H Zhang

Publications and source records attributed to H Zhang.

At least 469 records · Page 26Linked to original sources
PubMed2001

[A sinorhizobium fredll strain that effectively nodulate Medicago sativa].

Sinorhizobium fredii 042BS was isolated from root nodules of alfalfa (Medicago sativa) from Xinjiang Region. Nodulation experiments showed that both soybean and alfalfa were nodulated by 042BS effectively. The 16S rDNA PCR-RFLP analysis was carried out by four restriction endonucleases, and the restriction maps of strain 042BS were identical with those of S. fredii USDA205. The DNA G + C mol% of strain 042BS was 60.0. The DNA homology between 042BS and S. fredii USDA205 and USDA191 were 84.9% and 89.6%, respectively. To prove the capability of 042BS to nodulate both soybean and alfalfa, constitutively expressed green fluorescence protein gene(gfp) was introduced to 042BS, and the recombinant strain 042BSG was obtained. The reisolates from nodules of the soybean and alfalfa inoculated with 042BSG were observed using the confocal laser-scanning microscope, and the expressions of gfp were detected, respectively. 042BS showed various nodulation capacities with different alfalfa cultivars used.

Base Sequence↗
PubMed2001

[Homologous recombination in Streptomyces lincolnensis B48].

To study frequency and mechanism of homologous recombination in Streptomyces, an E. coli plasmid which cannot replicate in Streptomyces was transformed into Streptomyces lincolnensis B48. After homologous recombination between delta lincomycin biosynthetic genes inactivated by thiostrepton resistant gene (tsr) carried on pYYE04al and homologous sequences on the chromosome, S. lincolnensis YY1 and S. lincolnensis, YY2 were obtained on SMA with low thiostrepton concentration. Hybridization of chromosomal DNA samples of S. lincolnensis YY1, S. lincolnensis YY2, standard S. lincolnensis and S. lincolnensis YYc digested with SmaI with the probe of tsr gene gave signal corresponding to a fragment of 1.5 kb in the former two; Nevertheless, hybridization of chromosomal DNA digested with Hind III and Sma I using the probe of delta lacZ' gene resulted in positive fragment of 4.4 kb only in S. lincolnensis YY2. Southern hybridizations indicate that S. lincolnensis YY1 is the result of homologous exchange while S. lincolnensis YY2 comes from bomologous recombination. To prove the existence of E. coli replicon and ampicillin resistant gene on the chromosome of S. lincolnensis YY2, its DNA digested with SphI was ligated and then transformed into E. coli JM83 competent cell. Two transformants named pSLE1 grew on the plate containing ampicillin. It's confirmed that pSLE1 is a part of pYYE04a1 from its digestion with different enzymes.

Chromosomes, Bacterial↗
PubMed2001

[Study on the elimination of bacterial endotoxins by ultrafiltration device].

An external-pressed polysulfone hollow fiber UF membrane, was made by phase inversion method. The cutoff molecular weight was 6000. The water permeation rate of this membrane module (psi 90 x 500 mm) is more than 150 L/hr.atm. The operating results show that the elimination of bacterial endotoxins by this membrane has reached the national standard in pharmacopoeia, and this technology is worthy to be extended over to medical industry. In addition, the essence of pyreotogen, the quantification units and measure methods for pyreotogen, and the operating conditions of UF device in the process of eliminating pyreotogen are introduced. Some critical points in operation was discussed.

Animals↗
PubMed2001

[Study on reference laboratory diagnostic index of liver-fire ascending syndrome].

OBJECTIVE: To explore the binding point of Syndrome Differentiation of TCM and disease differentiation by western medicine. METHODS: Selected laboratory diagnostic indexes were tested in 59 cases of Liver-Fire Ascending Syndrome (LFAS). Referring to clinical typing and staging, the data obtained were analysed by same syndrome with different diseases and same disease with different syndrome as well as the values determined in related syndrome-types were compared. RESULTS: The levels of prostaglandin F2 alpha (PGF2 alpha) and arginine vasopressin (AVP) in patients of LFAS were higher than those in patients with Liver-Kidney Yin-Deficiency Syndrome and Liver-Yang Hyperactivity Syndrome. As for linking between Syndrome-type and stage of disease, most cases (70%) of herpes simplex viral keratitis of LFAS were deep matrix layer type; and 100% hypertension patients with LFAS belonged to stage II. CONCLUSION: PGF2 alpha and AVP could be used as the reference laboratory diagnostic indexes of LFAS.

Adult↗
PubMed2001

[Effects of quanjia yangshen capsule on rate of polychromatic erythrocytic micronucleus formation and peripheral blood picture in mice treated by cyclophosphamide].

OBJECTIVE: To observe the effect of Quanjia Yangshen capsule (QJYS) on cyclophosphamide (Cy) induced teratogenesis and bone marrow in mice and to explore the mechanism of its clinical therapeutic effect. METHODS: Mice were separately administered with QJYS solely, Cy solely and QJYS + Cy and the effect on polychromatic erythrocytic (PE) micronucleus formation rate in the bone marrow of mice, and peripheral blood picture were observed and compared with the control group. RESULTS: High dosage of QJYS has no apparent effect on PE micronucleus formation rate and peripheral blood picture in the normal mice; Cy can obviously raise PE micronucleus formation rate (P < 0.01), and lowered WBC, RBC and Hb obviously (P < 0.01) in mice. After taking QJYS, the Cy induced micronucleus formation rate increasing and blood picture parameters lowering were controlled. The improvement in the high and middle dose QJYS group was significantly higher in comparing to that in the sole Cy group (P < 0.01); while the low dose QJYS group in comparing with Cy group also showed significant improvement (P < 0.01), except Hb value. CONCLUSION: QJYS could significantly antagonize teratogenic effect and inhibition to bone marrow of Cy, i.e., play an antagonistic role against the toxic and side-effects of Cy.

Animals↗
PubMed2001

[The design of ultrasound subsystem in PACS/HIS environment].

Playing an important role in PACS, ultrasound subsystem together with CT and X-radiography subsystems works as the image Provider and image processing center. In this paper, we propose a novel scheme on how to construct ultrasound subsystem and explain it with detailed work flow and software frame. We also give a discussion on how to expand such a subsystem.

Computer Communication Networks↗
PubMed2001

[Effects of isocarbophos on the integrity of epidermic cell membrane of human skin].

OBJECTIVE: To investigate the effects of isocarbophos, a new and highly effective organophosphorus pesticide on the membranes of keratinocytes. METHODS: The epidermic cells of human skin cultured in the medium were adopted as a biological material. The activity of lactate dehydrogenase (LDH) was used as an indicator. We tested the activities of LDH and alkaline phosphatase (ALP) in the medium in different isocarbophos dosage conditions. RESULTS: It was found that the activity of LDH in the medium decreased with the increase of isocarbophos dosage. The LDH activities of the dosage groups were statistically different from those of the positive and negative groups. The ALP activities were of no significant difference between the groups. CONCLUSION: The above findings reveal that isocarbophos does not damage the membranes of keratinocytes directly, however it inhibits the LDH of human skin keratinocytes; thus it is suggested that isocarbophos like most organophosphorus pesticides used widely can pass through the intact human skin and poison the body before the skin is damaged. Therefore, protection during work hours is of paramount importance.

Alkaline Phosphatase↗
PubMed2001

[Roles of CD43, CD20 and local IgE in the pathogenesis of nasal polyps].

OBJECTIVE: To estimate the roles of CD43, CD20 and total IgE in the pathogenesis of nasal polyps. METHOD: Twenty-six cases of nasal polyps and 20 cases of mucosa of middle turbinates were used in present study. RESULTS: The number of CD43+ cells, CD20+ cells and plasma cells in nasal polyps were significantly more than that in middle turbinates (P < 0.01). The positive rate of local IgE+ cells in nasal polyps was significantly higher than in middle turbinate (P < 0.01). CONCLUSION: There were active cellular immunity and humoral immunity in nasal polyps. Local allergy may play a role in the pathogenesis of nasal polyps.

Adolescent↗
PubMed2001

[Expression of vascular endothelial growth factor and transforming growth factor-beta 1 in nasal polyps].

OBJECTIVE: To study the expression and significance of vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) and transforming growth factor-beta 1(TGF-beta 1) in nasal polyps. METHODS: Expression of VEGF/VPF and TGF-beta 1 in nasal polyps from 34 patients and middle turbinates from 30 patients with deviation of nasal septum was prospectively studied with immunohistochemistry. Tissue sections were observed under optical microscope. RESULTS: (1) The VEGF/VPF positivity in vascular endothelium and in glandular cell was significantly higher in nasal polyps than in middle turbinates (P < 0.01 and P < 0.05, respectively); (2) The TGF-beta 1 positivity in extracellular matrix and in cells in the stroma was significantly higher in nasal polyps than in middle turbinates(P < 0.005); (3) The distribution and shape of TGF-beta 1 expressing cells in nasal polyps were similar to that of eosinophil, their positivities were significantly correlative; (4) The positivity of VEGF/VPF and TGF-beta 1 did not correlate with clinical type in nasal polyps (P > 0.05). CONCLUSION: (1) The VEGF/VPF may play a key role in the formation of heavy edema of nasal polyps; (2) The TGF-beta 1 may contribute to some of the pathologic changes observed in nasal polyps, such as thickening of the epithelial basement membrane and stromal fibrosis; (3) Eosinophils in nasal polyps represent a major source of TGF-beta 1.

Adolescent↗
PubMed2001

[Effect of mm-LDL on NF-kB activation in endothelial cell].

OBJECTIVE: To investigate the signal transduction pathway of NF-kB activated by minimally modified low density lipoprotein (mm-LDL) in endothelial cells and the effect of NF-kB on platelet derived growth factor b (PDGFb) mRNA expression. METHODS: mm-LDL was prepared through iron oxidation by dialyzing the native LDL against FeSO4 in PBS. Endothelial cells were incubated in a medium containing mm-LDL, TNF, and IL-1 respectively and electrophoretic mobility shift assay (EMSA) was displayed to check on the activation of NF-kB. Luciferase reporter gene was analysed to investigate the effect of nuclear factor inducing kinase (NIK), inhibitor of NF-kB kinase alpha (IKK alpha) and inhibitor of NF-kB kinase beta (IKK beta) on NF-kB activation. In addition, endothelial cells were transfected using PDGFb promoter-luciferase for reporter gene analysis or transfected with mut-NIK for slot blot analysis to study the effect of NF-kB on PDGFb mRNA expression. RESULTS: mm-LDL was able to activate NF-kB in endothelial cells. mut-NIK and mut-IKK beta inhibited luciferase activity induced by mm-LDL. mm-LDL could also enhance luciferase activity controlled by upstream sequence of PDGFb promoter which contains element interacting with NF-kB. Result of slot blot showed inhibition of PDGFb mRNA expression by mut-NIK in the endothelial cells stimulated by mm-LDL. CONCLUSION: mm-LDL may activate NF-kB through NIK-IKK beta pathway and promote PDGFb mRNA expression in endothelial cells.

Cells, Cultured↗
PubMed2001

[The Raman spectra study on crystal-octadecyl hydrogen succinate crystal].

Raman spectra of crystal-octadecyl hydrogen succinate (OHS), whose geometric disposition of the experiment has y(zx)y, y(zz)y, and y(xz)y,y(xx)y respectively, have been recorded and analyzed with the purpose of understanding the structure of OHS crystal. It shows that some of the Raman-active modes of alkyl chain appear polarization. The analysis for crystal structure indicates that the molecular of OHS arrange in layers along [100] and [001] by the mode of dimers, and the molecular layers of chain pile up along [010]. The other groups of OHS corresponding Raman vibration peaks have been analyzed as well.

English Abstract↗
PubMed2001

[Effects of low frequency pulsed electric field on insulin studied by fluorescent spectrum].

Insulin, an intercellular signal molecular, plays a critical role in transferring life information. The studies on effects of pulsed electric fields on insulin molecular are meaningful for explaining the mechanism of biological effects of electromagnetic fields. The experiment results demonstrate that the conformation of insulin molecular has been altered by electric fields exposure for 30 minutes or by heat exposure for 50 hours. The results suggest that pulsed electric field exposure as heat exposure will after conformation of insulin molecular by breaking some hydrogen bonds and recombining another hydrogen bonds. The intercellular signal molecular may be an important target of electromagnetic fields.

Electricity↗
PubMed2001

[Spectrum studies on titania photocatalysts].

The nano-sized TiO2 photocatalysts were prepared by sol-gel method and characterized by FTIR spectroscopy, FT-Raman spectroscopy and diffuse reflectance spectroscopy(DRS). Photocatalytic degradation of oleic acid over the TiO2 catalysts was investigated. The result showed that calcination temperature has strong effect on crystal structure, energy band structure, optical adsorption and photocatalytic activity of the TiO2 catalysts. It was found that the TiO2 photocatalyst calcined at 400 degrees C has the best apparent optical adsorption, the biggest band edge position and the highest photoactivity. The effect of calcination temperature on photocatalytic activity of TiO2 catalysts has been ascribed to the changes in structure and optical property of catalyst such as crystal size, content of rutile, residual NO3-, and band-edge position of light adsorption.

Adsorption↗
PubMed2001

[Determination of Pd, Pt and Au by microwave plasma torch atomic emission spectrometry using an on-line clean-up].

In this paper, in the presence of Li+, Na+, K+, Ca2+ and Mg2+, determinations of Pd, Pt and Au by microwave plasma torch atomic emission spectrometry (MPT-AES) using an on-line clean-up were studied. It was shown from the experiments that these interfering matrix elements might be removed with the strong acidic cation exchange resin. The method was applied to the analysis of some practical samples and the results obtained were satisfactory.

Cation Exchange Resins↗
PubMed2001

[ATR-FTIR studies on the packing film].

FTIR and ATR-FTIR of the packing film have been studied. The dimension of thickness is about 0.034 m/m, the right and wrong sides of this packing film is composed of polypropylene and polyethylene glycol terephthalate, respectively.

English Abstract↗
PubMed2001

[A primary study on the relationship between condyle position and anterior distraction for cross bite caused by cleft lip and palate].

OBJECTIVE: To evaluate the changes of the position of the mandibular condyle in cleft lip and palate patients with secondary bony cross-bite deformity after early orthodontic treatment with extraoral bow and facial mask. METHODS: The TMJ topograph 6 months before and after treatment was investigated in 8 patients. The width of the anterior,superior and posterior space of the TMJ was compared prior to and post treatment. RESULTS: The results showed that there was no significant difference in the width of the three spaces of the TMJ before and after treatment. CONCLUSION: The position of the mandibular condyle had no significant change after maxillary anterior distraction with extraoral bow and facial mask.

English Abstract↗