Search PubMed⌕ Search

Biomedical subjects

Peng Wang

Publications and source records attributed to Peng Wang.

At least 109 records · Page 6Linked to original sources
PubMed2005

Effects of slow-release urea fertilizers on urease activity, microbial biomass, and nematode communities in an aquic brown soil.

A field experiment was carried out at the Shenyang Experimental Station of Ecology (CAS) in order to study the effects of slow-release urea fertilizers high polymer-coated urea (SRU1), SRU1 mixed with dicyandiamide DCD (SRU2), and SRU1 mixed with calcium carbide CaC2 (SRU3) on urease activity, microbial biomass C and N, and nematode communities in an aquic brown soil during the maize growth period. The results demonstrated that the application of slow-release urea fertilizers inhibits soil urease activity and increases the soil NH4+-N content. Soil available N increment could promote its immobilization by microorganisms. Determination of soil microbial biomass N indicated that a combined application of coated urea and nitrification inhibitors increased the soil active N pool. The population of predators/omnivores indicated that treatment with SRU2 could provide enough soil NH4+-N to promote maize growth and increased the food resource for the soil fauna compared with the other treatments.

Acetylene↗
PubMed2005

Study on remodeling of astrocytes in facial neuclus after peripheral injury.

To observe the glial reactions surrounding facial motor neurons following facial nerve anastomosis. At 1, 7, 21 and 60 d following facial nerve anastomosis, the recovery process of facial movement was observed, the glial fibrillary acidic protein (GFAP) immunoreactivity was analyzed by a combined method of fluorescent retrograde tracing and immunofluorescent histochemical staining, and the ultrastructure of astrocytes were observed under a transmission electron microscope (TEM), respectively. Postoperatively the function of facial muscles could not return to normal, often accompanied with hyperkinetic syndromes such as synkinesis at the late stage. Motor neurons in every facial subnucleus could be retrogradely labeled by fluoro-gold (FG), and displayed an evident somatotopic organization. Normally there was a considerable number of GFAP-positive cells in nonnucleus regions but few inside the facial nucleus region. Postoperatively the GFAP immunoreactivity in the anastomotic side increased significantly, but gradually decreased at the late stage. The ultrastructure of astrocytes in our experiment showed that the sheet-like process of astrocytes invested and protected the injured facial motor neurons. The present study shows that reactive astrocytes undergo some characteristic changes during the process of facial nerve injury and regeneration. The plastic change at the late stage may be involved in the mechanism of synkinesis.

Animals↗
PubMed2005

Molecular cloning and characterization of AAAS-V2, a novel splice variant of human AAAS.

Triple-A syndrome (MIM 231550; also known as Allgrove syndrome) is an autosomal recessive disorder characterized by adrenocorticotropin hormone (ACTH)-resistant adrenal insufficiency, achalasia of the oesophageal cardia and alacrima. Much initial molecular analysis supported that Triple-A syndrome was caused by mutations in AAAS, a WD-repeat protein gene. Here we report cloning and characterization of a novel splice variant of human AAAS, which we named AAAS-v2, which is located on the human chromosome 12p13. The cDNA is 1703 bp, encoding a 513-amino acid polypeptide, which contains three WD40 domains, one less than the original which we called AAAS-v1 (Gen Bank: NM_015665.3). RT-PCR analysis in our work revealed that AAAS-v2 and AAAS-v1 were ubiquitously detected in human multiple tissue cDNA (MTC) panels (CLONTECH).

Alternative Splicing↗
PubMed2005

Chitinase genes in lake sediments of Ardley Island, Antarctica.

A sediment core spanning approximately 1,600 years was collected from a lake on Ardley Island, Antarctica. The sediment core had been greatly influenced by penguin guano. Using molecular methods, the chitinolytic bacterial community along the sediment core was studied over its entire length. Primers targeting conserved sequences of the catalytic domains of family 18 subgroup A chitinases detected group A chitinases from a wide taxonomic range of bacteria. Using quantitative competitive PCR (QC-PCR), chitinase gene copies in each 1-cm section of the whole sediment column were quantified. QC-PCR determination of the chitinase gene copies indicated significant correlation with phosphorus and total organic carbon concentration, suggesting a historical connection between chitinase gene copies and the amount of penguin guano input into the lake sediment. Most of the chitinase genes cloned from the historic sediment core were novel. Analysis of the chitinase gene diversity in selected sediment layers and in the fresh penguin deposits indicated frequent shifts in the chitinolytic bacterial community over time. Sequence analysis of the 16S rRNA genes of chitinolytic bacteria isolated from the lake sediment revealed that the isolates belonged to Janthinobacterium species, Stenotrophomonas species of gamma-Proteobacteria, Cytophaga species of the Cytophaga-Flexibacter-Bacteroides group, and Streptomyces and Norcardiopsis species of Actinobacteria. Chitinase gene fragments were cloned and sequenced from these cultivated chitinolytic bacteria. The phylogeny of the chitinase genes obtained from the isolates did not correspond well to that of the isolates, suggesting acquisition via horizontal gene transfer.

Antarctic Regions↗
PubMed2005

[Experimental study on effects of shengmai injection: enhancing 5-FU anti-tumor efficacy and reducing its toxicity].

OBJECTIVE: To observe the effects of Shengmai Injection on enhancing efficacy and reducing toxicity of 5-fluorouracil (5-FU). METHODS: Fifty hepatoma 22 bearing mice were randomly divided into five groups: control group, 5-Fu group, Shengmai Injection (low, medium and high dose) combined with 5-FU groups. There were 10 mice in each group. Mice in the five groups were injected introperitoneally the same amount of normal saline, 5-FU (20 mg.kg(-1).d(-1)) and Shengmai Injection (3.5 ml.kg(-1).d(-1), 7 ml.kg(-1).d(-1) and 14 ml.kg(-1).d(-1)) combined with 5-FU respectively, once a day for 14 days. After that, all mice were killed and the tumor inhibiting rates, index of immunological function, liver and kidney function and the blood cells in the peripheral blood were observed. RESULTS: The tumor inhibiting rates were higher in each Shengmai Injection combined with 5-FU group than that in the 5-FU group (P<0.05). The levels of CD3, CD4, CD4/CD8, IgG, IgM in 5-FU group were lower (P<0.05), while those in the three Shengmai Injection combined with 5-FU groups were higher than those in the control group (P<0.05). The level of serum alanine aminotransferase (ALT) was higher and the WBC and PLT counts in the peripheral blood were lower in 5-FU group than those in the control group (P<0.05). But the levels of serum ALT in the three Shengmai Injection combined with 5-FU groups were consistent with that in the control group and the amounts of WBC decreased slightly. CONCLUSION: Shengmai Injection can enhance the anti-tumor effect of 5-FU. It can also improve the immunological function and reduce the adverse reactions of chemotherapy.

Animals↗
PubMed2005

[Studies on the system for the exclusive control substance in traditional Chinese herbal medicines].

OBJECTIVE: To establish the system for the exclusive control substance of plant drug (CSPD) in traditional Chinese herbal medicines (TCHM) for the purpose of original identification. METHOD: Three kinds of representative TCHMs were selected and their exclusive CSPDs were obtained by standardized procedure. The expression of the total chemical characteristic of the CSPDs were achieved with the comparative analysis of the 1H-NMR spectra for the CSPDs of the samples of the same species collected from different regions as well as the isolation and elucidation of the chemical constituents. RESULT: The 1H-NMR spectra of the CSPDs for three kinds of representative TCHMs have highly characteristic features and reproducibility, and showed mainly the resonance signals of the characteristic constituents of each species. These 1H-NMR spectra were strictly correlative with the origin of the species. CONCLUSION: By using the procedure of this paper, the exclusive CSPDs can be obtained for most of TCHMs, which have important significance and can be regarded as references in the original identification of TCHMs.

Alkaloids↗
PubMed2005

[Progress on the vaccine for anthrax].

Bacillus anthracis is the causative organism of the potentially fatal disease anthrax, and the used vaccines have some disadvantages. There are new developments appeared for the Bacillus anthracis in recent years, such as anti-PA antibody kills the spore of Bacillus anthracis, mucosal immunization induces immune responses in both systemic and secretory immune compartments, Poly (gamma-D-PGA) protein induce IgG antibodies to the vegetative bacteria, new pathogens were found by genomic analysis. The DNA vaccine and live vector vaccine will be the next generation vaccines for anthrax. It will have a shorter immunization schedule and will be greater protective efficacy than before.

Anthrax↗
PubMed2005

[Selection behavior of Cuscuta japonica on their hosts].

A field investigation on the selection behavior of Cuscuta japonica on their hosts showed that among the test plant communities, the number of coiling, the time of haustorium occurring, and the rate of coiling of C. japonica on hosts followed the order of B. papyrifera, W. chinensis, I. cairica, and L. camara; but the length of the elongation of C. japonica growing tips from coiling to haustorium occurring was with the order of L. camara, I. cairica, W. chinensis, and B. papyrifera. Furthermore, the growing tips of C. japonica coiled 3 circles in left direction on all selected hosts in 12 hrs, but grew away after contacting PVC rods within 24 hrs. The host diversity of C. japonic was beneficial to the survival of both C. japonica and its hosts. The selection behavior of C. japonica on their hosts had no correlation with the total N contents of different hosts. It could be postulated that the secondary metabolites of hosts made a contribution to the selection behavior of C. japonica on their hosts.

Broussonetia↗
PubMed2005

[Papillary renal cell carcinoma: clinico-pathologic studies of 33 cases].

OBJECTIVE: To investigate the morphologic features, differential diagnosis, prognosis and histogenesis of papillary renal cell carcinoma (PRCC). METHODS: Tumors composed of at least 50% papillae and > 1 cm in diameter were included in this study. Light microscopic observation, immunohistochemical assay of EMA, CK7, CD10, Vim, 34 beta E12 by tissue chip were performed. RESULTS: Among 516 cases of renal epithelial tumors 33 cases of PRCC were detected. Grossly, hemorrhage, necrosis and multifocality were commonly seen. Besides typical papillae, inconspicuous papillary patterns, such as trabecular, tubular, micronodular and pseudostratified patterns could be seen. Foam cells and psammoma bodies in stroma, and hemosiderin in tumor cells were characteristic. Tumors were of two major types: basophilic type (n = 10), with small cuboid cell and pale cytoplasm (n = 10), 9 of them were low in Fuhrman grading; eosinophilic type (n = 22) with large columnar cells, rich in eosinophilic cytoplasm, 19 of them were high in Fuhrman grading. The remaining case was of clear cell type. The basophilic tumors were all positive for distal tubule marker EMA/CK7, none for proximal tubule marker CD10, 7 tumors positive for Vim. Eosinophilic tumors were positive for EMA/CK7 (9/22), CD10 (10/22) and Vim (6/22). All the tumors studied were negative for 34 beta E12. Follow-up data were available for 24 cases (mean 37 months) with 3-year survival rate of 64.3%, 5-year survival rate of 50%. CONCLUSION: PRCC was a distinct malignant entity with unique pathological features. The prognosis of PRCC was worse than that of chromophobe renal cell carcinoma.

Adult↗
PubMed2005

[Clinicopathological study of 4 renal juxtaglomerular cell tumors].

OBJECTIVE: To investigate the clinical characteristics, morphologic and immunohistochemical features, diagnosis, differential diagnosis, histogenesis and prognosis of renal juxtaglomerular cell tumor (JGCT). METHODS: Light microscopic observation; immunohistochemical assay of CK8, E-cadherin/CK7, CD10, Vim, Actin, CD34, S100, HMB45, CD31, Chr, Syn and CD117, EM; and follow-up were done on all 4 surgically treated JGCT patients. RESULTS: All 4 JGCT were observed in young adult with clinically uncontrolled severe hypertension. Grossly, the tumor was encapsulated and small in size. Microscopically, the tumor cells grew in sheets predominantly, but papillary and onion-like pattern could also be seen. The stroma contained prominent vasculature that consisted of numerous thin-wall vessels clustering around thick-walled vessels. Tumor cells were rather small, polygonal, with slightly eosinophilic cytoplasm and ill-defined cell border. Nuclei were uniform in size but nuclear atypia and mitosis could be seen. Numerous mast cells were scattered among the tumor cells, and tubules were identified in 3 of 4 cases with positive expression of distal tubule marker of E-cadherin/CK7. Tumor cells positively expressed Vim, Actin, calponin, and CD34. All cases presented ultrastructural features of distinct rhomboid-shaped crystal. There was no recurrence or metastasis but hypertension persisted in three during follow-up (mean 37 months) for all 4 JGCT patients. CONCLUSION: JGCT, originating from the juxtaglomerular cell, has a distinct benign entity, and it is typically found in young adults with severe hypertension. It has a unique morphology and ultrastructure features and positive immunoreactivity to Vim, Actin, calponin and CD34.

Actins↗
PubMed2005

[Clinicopathologic study of 369 B-cell non-Hodgkin lymphoma cases, with reference to the 2001 World Health Organization classification of lymphoid neoplasms].

OBJECTIVE: To describe the relative frequency, morphologic features, immunophenotype and clinical data of different types of B-cell non-Hodgkin lymphoma (B-NHL) and to evaluate the practical application of the 2001 World Health Organization (WHO) classification of lymphoid neoplasms. METHODS: 369 documented cases of B-NHL were further subtyped according to the 2001 WHO classification of lymphoid neoplasms, on the basis of hematoxylin and eosin staining, immunohistochemistry and in-situ hybridization techniques. RESULTS: Amongst the 369 cases of B-NHL studied, 353 cases could be further classified into 11 subtypes. Diffuse large B-cell lymphoma, extranodal marginal zone lymphoma and follicular lymphoma were the commonest subtypes, accounting for 51.2% (189 cases), 14.9% (55 cases) and 10.6% (39 cases) of all cases respectively. Tumors in lymph nodes were seen in 158 cases (42.8%) and in extra node in 211 cases (57.2%). B-cell prolymphocytic leukemia and hairy cell leukemia were not identified. When comparing the diagnosis based on morphologic examination alone with the diagnosis based on both morphology and immunophenotype, there was a 80% concordance rate. Immunohistochemical study was helpful in reaching the correct diagnosis in many cases and could improve the overall diagnostic accuracy by about 20%. CONCLUSIONS: Amongst cases of B-NHL, diffuse large B-cell lymphoma is the commonest subtype, followed by MALToma and follicular lymphoma. While morphologic examination forms the basis for lymphoma diagnosis, immunohistochemical study also plays an important role in further subtyping. A combination of both modalities are sufficient for arriving at an accurate diagnosis in most cases of B-NHL, in keeping with the recommendation of the 2001 WHO classification of lymphoid neoplasms.

Adolescent↗
PubMed2005

[Synthesis, characterization and blood compatibility studies of waterproof breathable polyurethanes].

Adopting the two-step method and changing the proportion between PEG (Polyethylene glycol) and PTMG (poly (tetrahydrofuran), we used the MDI (4,4'-diphenylmethane diisocyanate) and short chain extender BDO (1,4-butanediol) as hard segment, the PTMG and PEG as soft segment, and hence prepared a series of polyether-based thermoplastic polyurethanes. FTIR showed the structure character of these polyurethanes. The determination of mechanics property and water contact angles revealed their good mechanics properties and hydrophilicity. Blood compatibility was evaluated by hemolysis test and platelet adhesion test, which revealed their good hemocompatibility. So those polyurethanes may be of wide application in the future.

Animals↗
PubMed2005

[Observation on therapeutic effect of warming acupuncture and moxibustion combined with Chinese drugs on ovarian cysts].

OBJECTIVE: To observe the therapeutic effect of acupuncture and moxibustion combined with Chinese herbs on ovarian cysts. METHODS: Forty-six cases were randomly divided into a treatment group of 26 cases and a control group of 20 cases. The treatment group were treated with warming acupuncture and moxibustion at Zigong (EX CA 1), Qihai (CV 6), Sanyinjiao (SP 6), etc. and oral administration of Chinese herbs Quyu Decoction, and the control group were treated with Quyu Decoction only. One month later, their therapeutic effects were observed. RESULTS: The cured rate and the effective rate were 53.8% and 88.4% in the treatment group, and 15.0% and 85.0% in the control group, respectively, the cured rate in the treatment group being significantly better than that in the control group (P<0.01). CONCLUSION: Warming acupuncture plus moxibustion combined with oral administration of Quyu Decoction can significantly increase the cured rate for ovarian cysts.

Acupuncture Therapy↗
PubMed2005

[The effect of gap blocker 1-heptanol on function and morphology of guinea pig cochlea].

OBJECTIVE: To investigate the role of gap junctions in hearing function of guinea pig in vivo. METHOD: Seven guinea pigs were inoculated with 1-heptanol into perilymphatic space after a small hole was drilled in the bony wall near tympanic scala of the base turn. Auditory brainstem response (ABR) was recorded before, 30 min, 60 min, 90 min 120 min after operation. Two hours after surgery, all the animals were killed and the ultrastructure of guinea cochlea was observed by making electron microscopy specimens. RESULT: The application of 1-heptanol into guinea pig cochlea resulted in large increase in ABR threshold, which showed 30 to 40 dB elevation in guinea pig. And 1-heptanol could destroy the gap conjunction structure between hair cells and Deiter's cells in guinea cochlea. CONCLUSION: The gap blocker 1-heptanol might significantly influence the guinea pig's hearing function, and the gap conjunction might play an important role in normal cochlear function and K+ recycle in inner ear of guinea pig.

Animals↗
PubMed2005

Dye removal from wastewater using the adsorbent developed from sewage sludge.

Sewage sludge was used to develop an effective carbon adsorbent. This adsorbent was employed for the removal of azo dye such as Direct Dark Brown M and Acid Mordant Brown RH. The adsorption of dyes on this adsorbent was studied as a function of contact time, concentration, pH and temperature by batch method. The equilibrium adsorption capacity of a carbonaceous adsorbent prepared from city wastewater treatment plant was 502, and 329.7 mg/g of Direct Dark Brown M and Acid Mordant Brown RH, respectively. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. Equilibrium data fitted well with the Langmuir model. The rates of adsorption were found to conform to the Lagergren second-order kinetics with good correlation. The equilibrium adsorption capacity of the carbonaceous adsorbents was determined with the Langmuir equation as well as the Lagergren second-order rate equation. The most ideal pH for adsorption of two dyes onto adsorbents was found to be 3 and below. The results indicate that the carbonaceous adsorbents could be employed as a low cost adsorbent in the removal of dyes from wastewater.

Adsorption↗
PubMed2005

[High level expression of PNGase F in Escherichia coli and its bioactivities].

In order to obtain active recombinant PNGase F in Escherichia coli, a prokaryotic expression vector pET28a/PNGase F was constructed. Amplification of PNGase F was obtained using PCR technique employing suitable primers designed according to the PNGase F gene sequence from Flavobacterium nmeningosepticum. The expression of PNGase F gene in LB medium or M9 medium led to the formation of inclusion body and soluble protein, respectively. The refolding of the denatured inclusion body was successful by gradual dilution. Further purification of the refolded protein and soluble crude extract from M9 medium with Ni2+ -NTA argarose resulted a 90% purified PNGase F. The purified protein catalyzed the complete and intact cleavage of N-linked oligosaccharides from various glycoproteins. The efficiency of this cleavage was affected by the substrate status in the reaction system. In summary, we have developed an enzyme production system where PNGase F was over-expressed in recombinant E. coli. This system can provide more than 15 mg/L purified active PNGase F. This purified active PNGase F can be used as tools in analyzing the oligosaccharide structure.

Bacterial Proteins↗