Biomedical subjects

G Wu

Publications and source records attributed to G Wu.

At least 217 records · Page 12Linked to original sources

PubMed2000

[Primary research on interface ecology in agroforestrial ecosystems].

In this paper, the fundamental conception, major research content of interface ecology and its application in agroforestrial systems were discussed. The action mechanism between trees and crops in agroforestrial systems mainly embodied aboveground interface for competitve light, quantity of heat and water, and underground interface for competitiye nutrient and water. It was showed in the interchange and transmission of nutrient, energy and information through interface.

Biomass↗

PubMed2000

[Relationship between human activities and survival of rare and endangered species Davidia involucrata].

In recent years, the increasing intensity of human activities and the increase of regional developing items led to a sharp decrease of natural distributed area and natural population number of rare and endangered species Davidia involucrata, and now, its natural distributed population is on the point of extinction. This paper analyzed the geographic distribution situation of Davidia involucrata in different geologic and historical periods, and discussed the major reasons for forming the geographic distribution and dynamic changes of population. Through many field investigations and references, some protecting measures were presented.

Ecosystem↗

PubMed2000

[Consideration for ecological planning in mining areas].

On the basis of summarizing the status and trend of domestic and overseas ecological planning research, the necessity and significance of ecological planning research in mining areas were analyzed and its characteristics, research objectives, contents and methods were discussed. It is pointed out that establishing the theory and methodology of ecological planning in mining area is not only the requirement of their sustainable development, but also the requirement of active participation and cooperation of the researchers from different disciplines.

Conservation of Natural Resources↗

PubMed2000

Anti-fecundity immunity in mice immunized with anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum.

OBJECTIVE: To observe the effects of anti-fecundity and anti-embryonation immunity of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum on female adult worm. METHODS: The active immunization of C57BL/6 mice was conducted by means of three intraperitoneal injections of NP30. The control group was injected with SP2/0 ascites intraperitoneally. RESULTS: On the twenty-seventh day after challenge infection, the number of eggs in the liver tissue and in uterus of the group immunized with NP30 decreased by 30.91% and by 38.55%, respectively. On the thirty-ninth day after the challenge infection, the number of mature eggs in the liver tissue of the group immunized with NP30 decreased by 66.63% and the number of dead eggs increased by 60.66%. CONCLUSIONS: NP30, with which mice were actively immunized, possesses double effects of anti-fecundity and anti-embryonation immunity on female adult worm of Schistosoma japonicum, therefore it can be used as a promising candidate of anti-pathologic vaccine molecule against Schistosomiasis japonica.

Animals↗

PubMed2000

[Experimental study on effect of antagonizing platelet-activating factor and histamine of synthetic ginkgolide F in guinea-pigs].

OBJECTIVE: To investigate the antagonizing effect of synthetic Ginkgolide F (SGF) on platelet-activating factor (PAF) and histamine (HA) in guinea-pigs. METHODS: The contraction rate of isolated lung tissue of guinea-pig and the change of pulmonary function of sensitized guinea-pig after SGF treatment were examined. RESULTS: (1) The contraction rate of guinea-pigs' isolated trachea and lung strip induced by HA reduced from (50.97 +/- 16.00)% and (54.24 +/- 12.17)% to (21.69 +/- 3.85)% and (22.97 +/- 17.78)% after SGF treatment (P < 0.05). (2) PAF induced relative contraction of isolated guinea-pig lung strip was reduced from (89.49 +/- 16.00)% to (46.21 +/- 14.23)% in presence of SGF (P < 0.05). (3) The pulmonary function of sensitized animal had a tendency of being improved by SGF. CONCLUSION: SGF can antagonize the contraction of isolated lung tissue induced by HA or PAF in vitro, and has a tendency to improve the pulmonary function of sensitized guinea-pig, therefore, it may be a promising drug in treatment of bronchial asthma.

Animals↗

PubMed2000

[Clinical application of magnetic resonance angiography in the body].

OBJECTIVE: To identify the accuracy and reliability of magnetic resonance angiography (MRA) in evaluating patients with vascular lesions in the body. METHODS: 171 patients with suspected vascular lesions in the body were examined by MRA and compared with the results of X-ray angiography (XRA) or operation. RESULTS: MRA showed abnormal vein in 12 patients and normal in 6 corresponding to XRA or operation. MRA revealed aneurysm in 54 patients: aortic dissection (26), aortic aneurysm (15) and peripheral aneurysm (13). Two peripheral aneurysms could not only be found by MRA. The sensitivity of MRA was 97% for aneurysm lesions. The sensitivity of MRA in the diagnosis of suspicious peripheral artery stenosis in 84 patients was 95%, the specificity 89%, and the accuracy 92% in comparison with those of XRA and operation. CONCLUSION: MRA is accurate and reliable in evaluating vascular lesion in the body and can replace XRA in many cases.

Adolescent↗

PubMed2000

[Fiberoptic ductoscopy for patients with intraductal papillary lesions].

OBJECTIVE: To investigate the clinical significance of fiberoptic ductoscopy in patients with intraductal papillary lesions. METHODS: Fiberoptic ductoscopy was applied to patients with nipple discharge. The characteristics of those with intraductal papillary lesion were analysed. RESULTS: 92 patients were found to have intraductal papillary lesions. 68 patients were revealed to have single papillomas and 21 multiple papilloma. Three patients were diagnosed with papillomatosis. A total of 114 lesions were observed. 29.8% of these lesions were located in the segmental duct. 43.9% lesions were located in the first branch of the segmental duct and 17.5% in the second branch. Only 7.9% and 0.9% lesions were located in the third and the fourth branch. The average distance from lacteous pore to papillary lesion was 2.7 cm. Fiberoptic ductoscopy did not find lesions in 5 patients. CONCLUSIONS: Fiberoptic ductoscopy can be used to diagnose and locate intraductal papillary lesions. It is an effective diagnostic method for nipple discharge.

Adult↗

PubMed2000

[A case control study on the distribution of apolipoprotein AI gene polymorphisms in the survivors of atherosclerosis cerebral infarction].

OBJECTIVE: To investigate the frequency of the restrict fragment length polimorphisms (RFLP) at 2 MspI sites in the 5' - end of apolipoprotein AI (ApoAI) gene and its potential interaction to atherosclerotic cerebral infarction (ACI) in Chinese Han population. METHOD: Polymerase chain reaction (PCR) technique was used in a sample of 199 cases with documented ACI and 204 healthy matched by age and sex individuals selected from Chinese Han nationality in Beijing. The studied loci include promoter region (-75 bp) and the intron - 1 (+83 bp). RESULTS: (1) Both ACI and control groups M1 + + and M1 + - were major frequent genotypes in Beijng area, M2 + + were major frequent genotypes in intron - 1; (2) M1 + - genotype appeared more common among patients than in controls (0.487 vs 0.368, P < 0.05, OR = 1.64); (3) Individuals with M1 + -/M2 + + haplotype were significantly increased in patients compared with controls (0.437 vs 0.314, P < 0.05, OR = 1.70). CONCLUSION: It is suggested that both M1 + - genotype and M1 + -/M2 + + haplotype of ApoAI gene might associate with ACI in our study.

Apolipoprotein A-I↗

PubMed2000

[Studies on three types of natural foci of tsutsugamushi disease in eastern part of China].

OBJECTIVE: In order to identify the types of natural foci of tsutsugamushi disease to provide basis for prevention, a series of studies were carried out in Fujian, Zhejiang and Jiangsu Provinces. METHODS: (1) Representative points for investigation in three Provinces were selected. (2) Data on geographical landscape and epidemiology were collected. (3) Field survey and experimental studies on rats and chigger mites in relation to the disease. RESULTS: Three representative types of natural foci of tsutsugamushi disease were demonstrated. They were (1) Coastal island type, mainly in Fujian with major reservoir host as Rattus losea and major vector mite as L. deliense; prevalent season: summer; type of Rt: Gilliam: (2) Inland mountain - forest type in Zhejiang with major reservoir host as R. confucianus and major vector miteas L. gaohuense; prevalent season: summer; type of Rt: Gilliam. (3) Inland plain - hills type in Jiangsu with major reservoir hosts: Apodemus agrarius, R. confucianus, R. norvegicus and Crocidura lasiura; major vector mite: L. scutellare; prevalent seasons: autumn and winter; type of Rt: Kawasaki. CONCLUSION: The types of Rt, reservoir hosts, vector chigger mites and epidemiological features of tsutsugamushi disease in Fujian, Zhejiang and Jiangsu Province were found different. Thus, the preventive measures should also be distinct from one another.

Animals↗

PubMed2000

[Determination of lidocaine in human spinal cord by high-performance liquid chromatography].

A RPHPLC method for determining lidocaine in human's spinal cord. Was established. The linear range of the method was 0.20-20.0 micrograms/ml(r = 0.9999). The detection limit was 0.02 ng/ml(S/N > or = 3) and the clean-up recovery of lidocaine in human spinal cord was 82.4%-92.7%. The CV% were no more than 6.0% (N = 4). No interfere by other compounds was observed in study results using this method. RPHPLC method shows an excellent recovery, high sensitivity and good precision.

Anesthesia, Epidural↗

PubMed2000

[Screening DPPH radical scavengers from Monascus sp].

A strain belongs to Monascus sp. was separated from hongqu(Chinese beni-coji) which was used to brew red wine in Changxin county, Zhejiang province, and its DPPH radical scavenging metabolites were studied. Results showed that the yield and radical scavenging activity of neutral extract with EtOAc were higher than that of acid and basic extract. After shaken at 30 degrees C, 100 r/min for 5 days, this strain produced largest amount of neutral extract. Further partitioning the neutral fraction with silica gel column chromatograph, LH-20 column chromatograph, MPLC and HPLC, we screened 15 free radical scavengers whose yield was more than 2 mg and purity was higher than 85% in HPLC (260 nm absorption). Several of them were analyzed with 1H-NMR and 13C-NMR spectrum from which we concluded that B1-3 and C3-1-7 were two kinds of substitute of benzene, and C3-1-7 may be 3-OH-4-OCH3-benzoic acid. The scavenging activity of 40 mumol/L B1-3 was about 65%, and that of C3-1-7 was lower than 56%, while as the control the scavenging activity of 40 mumol/L Vc and Ve was 80.4% and 78.4% respectively.

Benzene Derivatives↗

PubMed2000

[Effect of Cordyceps sinensis on the Th1/Th2 cytokines in patients with Condyloma Acuminatum].

OBJECTIVE: To investigate the effect of cordyceps sinensis (CS) on the Th1/Th 2 cytokines and recurrence in patients with Condyloma Acuminatum (CA). METHOD: Double-antibody sandwich ELISA was used to study the serum level of IL-2 and IL-10 in 34 patients treated with CS(CS group) and 29 patients in control group. The recurrence rate of CA was observed. RESULT: After treated with CS, the serum levels of IL-2 and IL-10 significantly increased and decreased respectively (P < 0.05 or 0.01). No significant change occurred in control group. The recurrence times of CA in patients of CS group after electrocauterization were significantly lower than control group (P < 0.05). CONCLUSION: CS might recover the balance of Th1/Th2 cytokines and enhance Th 1 immune response in patients with CA, and reduced the recurrence of CA.

Adjuvants, Immunologic↗

PubMed2000

[Interactions between domains within the NH2- and COOH-terminal fragments of presenilins].

OBJECTIVE: To analyze the interactions between domains within the NH2- and COOH-terminal regions of presenilins. METHODS: The various constructions corresponding to NH2-terminal fragment (NTF) and COOH-terminal fragment (CTF) derivatives of presenilin 1 (PS1) and presenilin 2 (PS2) were generated by RT-PCR, and their interactions were assayed by yeast two-hybrid system. RESULTS: Domains within the NH- and COOH-terminal fragments of presenilins could directly interact with each other, and therefore form high molecular weight complex. The interaction site between domains within PS1 located at amino acid 361-447 of PS1 CTF, without the involvement of other partners. Similar interaction was not observed between PS11-360 and PS2341-448, PS2(1)-340 and PS1(361)-467. CONCLUSIONS: Intramolecular interaction between domains within the NH2- and COOH-terminal regions of presenilins may be critical to the folding and assembly of mature PS molecules.

Binding Sites↗

PubMed2000

[Alternative splicing of de novo methyltransferase gene 3b in adult and newborn mice].

OBJECTIVE: To unravel the biological significance of the alternative splicing of de novo methyltransferase 3b, expression of the Dnmt3b gene in various tissues and developmental stages was investigated in postnatal mice. METHODS: RT-PCR and capillary electrophoresis were employed to analyze the alternative splicing pattern of Dnmt3b in tissues of newborn and adult mice. The results had been further reaffirmed by repeating and statistics analysis. Bioinformatics tools were used to predict the structure and hydrophobicity of the Dnmt3b exon10 coding sequence. RESULTS: Isoform with Dnmt3b exon10 was the abundant form in lung of newborn mice and in liver of both newborn and adult mice, while in other tissues of newborn and adult mice, the spliced isoform was presented as the predominant one. Peptide encoded by Dnmt3b exon10 was mainly random coil on the surface of Dnmt3b protein. CONCLUSIONS: The data demonstrate that the specific expression of Dnmt3b exists in tissues and developmental stages of postnatal mice. The alternative splicing of the exon 10 of Dnmt3b is possibly involved in the regulation of Dnmt3b's catalytic function. These results provide an insight into the developmental regulation and physiological function of the alternative splicing of the Dnmt3b gene.

Alternative Splicing↗

PubMed2000

[The comparison of luminescence properties for Ce3+, Tb3+ ions in the fluorides].

The matrix K3AlF6 was prepared with a reaction of mixture of solution K2CO3 upon certain solution of Al(OH)3 plus HF (40%), dehydrating at 100 degrees C and annealing for 48 h at 600 degrees C. A series of phosphors for Ce3+, Tb3+ ions in complex fluorides KBF4 and K3AlF6 were synthesized by a solid reaction method. Their excitation and emission spectra were determined, compared with phosphors KAlF4: Ce, Tb, CaF2: Ce, Tb and AlF3: Ce, Tb. The results indicated that Ce3+ could only effectively sensitize Tb3+ in KAlF4 and enhance the emission of Tb3+ significantly. Ce3+ can not effectvely transfer energy to Tb3+ in matrixes CaF2, AlF3, KBF4 and K3AlF6.

Cerium↗

PubMed2000

[Luminescence properties and energy transfer between Ce3+ and Gd3+ ions in KAlF4:Ce, Gd].

The matrix KAlF4 was prepared with a reaction of mixtures of solution K2CO3 upon certain solution of Al(OH)3 plus HF (40%), dehydrating at 100 degrees C and annealing for 48 h at 450 degrees C. A series of phosphors KAlF4:Ce, Gd were synthesized by a solid reaction method. Their excitation and emission spectra were determined. It was observed that Ce3+ could sensitize Gd3+ in KAlF4 effectively, so as to enhance the emission of Gd3+ significantly. But emission intensity of Gd3 + 6 P1/2-->8S7/2 decreased with the concentration of Gd3+ increased when the concentration of Ce3+ was constant.

English Abstract↗

PubMed2000

[Spectroscopy performances of Yb3+ doped YAG crystal].

The absorption and emission properties of Yb:YAG with different Yb3+ doped concentration have been studied systematically. The emission cross section has been evaluated using the absorption cross section and principle of reciprocity, which was consistent with previous reports. The absorption spectra of Yb2+ and color center were observed in as-grown Yb:YAG boules, which are removed by annealing the boules in oxygen at 1,300 degrees C for 24 h. The photon excited and X-ray excited optical luminescence of Yb:YAG were first discussed. The results indicated that Yb:YAG crystal was favourable for high-power diode-pumping.

Chemical Phenomena↗

PubMed1999

Specificity in transforming growth factor beta-induced transcription of the plasminogen activator inhibitor-1 gene: interactions of promoter DNA, transcription factor muE3, and Smad proteins.

Transforming growth factor beta (TGF-beta) regulates a broad range of biological processes, including cell growth, development, differentiation, and immunity. TGF-beta signals through its cell surface receptor serine kinases that phosphorylate Smad2 or Smad3 proteins. Because Smad3 and its partner Smad4 bind to only 4-bp Smad binding elements (SBEs) in DNA, a central question is how specificity of TGF-beta-induced transcription is achieved. We show that Smad3 selectively binds to two of the three SBEs in PE2.1, a TGF-beta-inducible fragment of the plasminogen activator inhibitor-1 promoter, to mediate TGF-beta-induced transcription; moreover, a precise 3-bp spacer between one SBE and the E-box, a binding site for transcription factor muE3 (TFE3), is essential for TGF-beta-induced transcription. Whereas an isolated Smad3 MH1 domain binds to TFE3, TGF-beta receptor-mediated phosphorylation of full-length Smad3 enhances its binding to TFE3. Together, these studies elucidate an important mechanism for specificity in TGF-beta-induced transcription of the plasminogen activator inhibitor-1 gene.

Base Sequence↗