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Biomedical subjects

G Yang

Publications and source records attributed to G Yang.

At least 91 records · Page 5Linked to original sources
PubMed2001

Smoking cessation in China: findings from the 1996 national prevalence survey.

OBJECTIVES: To describe patterns of smoking and smoking cessation in China within the context of the stages of change model, using data from the 1996 national prevalence survey. DESIGN: A cross sectional survey was carried out using the 145 preselected disease surveillance points, which provide a representative sample for the entire country. A standardised questionnaire on smoking was interviewer administered. SETTING: The country of China. SUBJECTS: 122,220 people aged 15-69 years. MAINTENANCE MEASURES: Smoking cessation patterns, as defined by smoking status (current or former) and stage of change (precontemplation, contemplation, and action). RESULTS: The sample included 45,995 ever smokers of whom 4336 had quit. About 72% of current smokers reported not intending to give up their smoking behaviour, and about 16% of current smokers said they intended to do so, but have not taken any action. Of all ever smokers, the percentage of former smokers was 9.5%, and 12% of current smokers had quit at least once, but relapsed by the time of the survey. The patterns were similar in men and women with regard to the stated intent to quit. Among males, the percentage of former smokers increased with age but the percentage intending to quit was constant at about 15% across age strata. The most common reason for quitting was illness. Participants with a university education were more likely to have made an attempt to quit. CONCLUSIONS: The percentage of smokers contemplating quitting was low in China in 1996. The study shows that smokers in China must be mobilised to contemplate quitting and then to take action.

Adolescent↗
PubMed2001

Evaluation of bacteria isolated from rice for plant growth promotion and biological control of seedling disease of rice.

Of 102 rhizoplane and endophytic bacteria isolated from rice roots and stems in California, 37% significantly (P < or = 0.05) inhibited the growth in vitro of two pathogens, Achlya klebsiana and Pythium spinosum, causing seedling disease of rice. Four endophytic strains were highly effective against seedling disease in growth pouch assays, and these were identified as Pseudomonas fluorescens (S3), Pseudomonas tolaasii (S20), Pseudomonas veronii (S21), and Sphingomonas trueperi (S12) by sequencing of amplified 16S rRNA genes. Strains S12, S20, and S21 contained the nitrogen fixation gene, nifD, but only S12 was able to reduce acetylene in pure culture. The four strains significantly enhanced plant growth in the absence of pathogens, as evidenced by increases in plant height and dry weight of inoculated rice seedlings relative to noninoculated rice. Three bacterial strains (S3, S20, and S21) were evaluated in pot bioassays and reduced disease incidence by 50%-73%. Strain S3 was as effective at suppressing disease at the lowest inoculum density (106 CFU/mL) as at higher density (10(8) CFU/mL or undiluted suspension). This study indicates that selected endophytic bacterial strains have potential for control of seedling disease of rice and for plant growth promotion.

Algal Proteins↗
PubMed2001

Characterization of a Ca2+-dependent protein kinase from rice root: differential response to cold and regulation by abscisic acid.

The Ca2+-dependent protein kinases (CDPKs) and abscisic acid (ABA) are known to be involved in low-temperature stress response. The focus of this study was to characterize the 45 kDa protein kinase identified in the crude extract of rice (Oryza sativa L.) seedling roots in response to cold (5 degrees C) stress. The activity of the 45 kDa protein kinase decreased at low temperature as evident by an in-gel kinase assay using histone III-S as a substrate. Also, the Ca2+-dependent activity of this protein kinase was suppressed by cold in the membrane fractions of the root. A general protein kinase inhibitor and Ca2+ chelator inhibited the activity of the 45 kDa protein kinase, suggesting that it was a plant CDPK. The 45 kDa CDPK identified was found to be independent of photosynthetic tissues such as the leaf and leaf sheath of rice seedlings, supporting a direct sensing mechanism in the roots of rice seedlings to cold stress. The suppressed activity of the 45 kDa CDPK was reverted by supplementing with 5 microM ABA under cold stress. The 45 kDa CDPK activity was stronger in the cold-tolerant variety of the 4 types tested than it was in the cold-sensitive one. These results suggest the involvement of endogenous ABA in regulating the activity of the 45 kDa CDPK in response to cold stress.

Abscisic Acid↗
PubMed2001

In situ gene therapy for prostate cancer: immunomodulatory approaches.

The development of effective treatments for prostate cancer is thwarted by the natural history of the disease. The biological and clinical potential of most individual cancers is uncertain. In many cases the disease will not progress to clinical significance but experimental and clinical studies indicate that prostate cancer can and may metastasis early in the course of the disease from relatively small foci (i.e., not necessarily the largest or index cancer). Localised prostate cancer is potentially curable with localised therapies (radical prostatectomy or irradiation therapy). However, there are no curative therapies for metastatic prostate cancer. Gene therapy, especially those approaches with an immunomodulatory component, may provide additional therapeutic options with the potential to affect both localised and systemic disease. We have pioneered the development and application of in situ gene therapy protocols using adenoviral vectors to transduce specific genes that generate cytotoxic activity and/or a systemic antitumour immune response. In addition we have completed initial studies that demonstrate the therapeutic potential of adenoviral vector-mediated gene modified cell-based vaccines. Our review discusses preclinical studies focused on the development of immunostimulatory in situ gene therapy approaches that hopefully will provide novel and effective treatments for localised and metastatic prostate cancer.

Animals↗
PubMed2001

[Studies on eicosapentaenoic acid production by submersion culture of Cryphecodinium cohnii].

The effects of the incubation temperature, initial pH of the medium, carbon source and nitrogen source on the production of Crypthecodinium cohnii C98 were studied. Through orthogonal experiments, the optimum culture medium was obtained (g/L): Glucose, 65; Yeast extract, 2.0; KNO3 3.0, KH2PO4 1.0, MgSO4.7H2O 0.6, NaCl 5.8, CaCl2.2H2O 0.1, ZnSO4.7H2O 0.0067, FeCl3.6H2O 0.014, CuSO4.5H2O 0.0004, MnSO4.H2O 0.0002. Under the optimum culture conditions, the microalgae dry cell weight and eicosapentaenoic acid was 18.3 g/L and 0.891 g/L, respectively. The submersion culture process was analysed.

Culture Media↗
PubMed2001

[Generation of human recombinant antibody Fab fragment to influenza virus from combined antibody library].

OBJECTIVE: To acquire the recombinant human monoclonal antibodies to influenza virus which can be used in mucous membrane treatment to prevent the infection of virus in animal model in the future. METHODS: Construct and pan human Fab antibody library to influenza virus Sydney strain (H3N2) from vaccinated donors by using phage display technology and secreted expression in E. Coli system. The positive Fab clones with neutralization activity to influenza virus were selected and characterized through HI test, IFA and VN test. RESULTS: Separate two Fab clones, IV-2 and IV-6, appear positive responses in ELISA and IFA. These two clones can inhibit hemagglutination in HI test and can decrease viral titer by 30 and 20 times in viral neutralization assay, respectively. CONCLUSION: We have got two clones of Fab fragments with neutralization activity to influenza virus Sydney strain (H3N2).

Cells, Cultured↗
PubMed2001

[Function of the leaky UGA codon in ssRNA plant virus genomes].

The opal mutation (UGA) at nucleotide 2670-2672 in the replicase gene of the attenuated tomato mosaic virus K (ToMV-K) mainly contributes to the virus attenuation based on a series of studies on the viral attenuation mechanism. From analysis and comparison between the replicase gene mutation point of ToMV-K and the related regions of all plant viruses containing the leaky UGA, we have found that some characters, including the CGG motif, alpha-helix structure and some specific amino acids, are, presumably, able to helpfully confer the readthrough mechanism. Finally, some other ssRNA plant viruses like PVX, PVY, CMV have been analyzed. We found that their genomic modifications and viral attenuations could be explored according to the mutation mode of the ToMV-K replicase.

Amino Acid Sequence↗
PubMed2001

Population-based, case-control study of blood C-peptide level and breast cancer risk.

Insulin resistance has been suggested to be associated with an increased risk of breast cancer. Insulin sensitivity can be measured using blood C-peptide, a marker of insulin secretion. It is thus conceivable that blood C-peptide levels may be associated with breast cancer risk. To evaluate this hypothesis, we analyzed data from a subset (143 case-control pairs matched by age and status of menopause) of women who participated in the Shanghai Breast Cancer Study, a population-based, case-control study conducted in Shanghai during 1996-1998. Fasting blood samples were collected from study subjects to measure C-peptide levels. For cancer patients, the samples were collected before any cancer therapy. Conditional logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals related to C-peptide levels. Breast cancer risk was increased with increasing levels of C-peptide (trend test, P = 0.01), with an odds ratio of 2.7 (95% confidence interval = 1.2-5.9) observed for the highest compared with the lowest tertile of C-peptide concentration after adjusting for body mass index and age at the first live birth. The risk was not altered after fully adjusting for other traditional risk factors for breast cancer. This positive association was observed in both pre and postmenopausal women and regardless of the levels of waist-to-hip ratio or body mass index. The results from this study were consistent with the insulin-resistance hypothesis for breast cancer and suggest that increased levels of C-peptide may contribute to the development of breast cancer.

Adult↗
PubMed2001

In situ prostate cancer gene therapy using a novel adenoviral vector regulated by the caveolin-1 promoter.

Caveolin-1, a structural component of caveolae, is overexpressed in metastatic and androgen-resistant prostate cancer and highly expressed in tumor-associated endothelial cells. The mouse cav-1 promoter was cloned and placed upstream of the HSV-tk gene in an adenoviral vector (Adcav-1tk) and compared with a cytomegalovirus (CMV) or Rous sarcoma virus (RSV) promoter-driven HSV-tk, AdCMVtk and AdRSVtk vectors, respectively. Mouse and human prostate cancer cells and mouse endothelial cells were infected with Adcav-1tk, AdCMVtk or control vectors without the HSV-tk gene (Adcav-1 and AdCMV) and subsequently treated with ganciclovir (GCV). GCV-mediated in vitro cytotoxicity induced by the Adcav-1tk vector was comparable to that for AdCMVtk in multiple mouse and human prostate cancer cell lines. To evaluate the activity of Adcav-1tk in vivo, orthotopic mouse prostate cancer tumors were generated with RM-9 cells and injected in situ with Adcav-1tk, AdCMVtk, AdRSVtk, or AdCMVbetagal (control) and treated with GCV. All three HSV-tk transducing vectors produced statistically significant reductions in wet weight and increased apoptotic indices compared with the control vector. However, only Adcav-1tk produced significant necrosis, and only Adcav-1tk and AdRSVtk caused significant decreases in microvessel density. In conclusion, Adcav-1tk demonstrated efficacy in vitro and in vivo in preclinical models of prostate cancer. Our results suggest that the cav-1 promoter may have unique benefits in targeting gene therapy to prostate cancer and its associated vasculature.

Adenoviridae↗
PubMed2001

[An off site petroleum-contaminated soil bioremediation technology: soil compositing in windrow].

With off-site bioremediation technology, a soil contaminated by crude oil from Liaohe Oil Field was treated on a 20 x 10 m prepared bed. 8 composting windrow units were set, each measured 8 m in length, 2 m in width, and 0.35 m in height. The results showed that when the pollutant petroleum hydrocarbon(TPH) was within the range of 4.16-7.72 g.100 g-1 soil, the total degradation rate of TPH reached 45.19%-56.74% after 53 days operation, which indicated that a technological basis would be provided for the bioremediation of oil-contaminated soil.

Biodegradation, Environmental↗
PubMed2001

[Causal factors of decline disease in exotic pine (Pinus taeda and P. elliottii) plantations].

Investigation on the cause of the decline of exotic pine plantations in Anhui Province was carried out from 1995 to 2000. The results showed that the cause might develop from the interaction of three or more sets of factors. The first group of factors called as predisposing factors were high and low temperature and rainfall, poor soil fertility, and excessive soil bulk density, soil moisture, and of stand density; the second group of factors called as inciting factors were insect defoliators, damaging diseases of needles, late spring frost, severe drought, and excessive resin-tapping, and the third group of factors called as contributing factors were several biotic agents such as shoot blight infected by Sphaeropsis sapinea, decay wood and root rot by fungi, and bark beetles and wood borers.

Causality↗
PubMed2001

[Relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) and forest stand and environmental factors].

The relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) plantations in Anhui Province and forest stand status and environmental factors was quantitatively analyzed. Among 18 variable factors from 4 types of factors(climate, soil, stand status, and other diseases and insect pests), 10 factors contributed greatly to the state of illness. These were tree age, stand density, resin-tapping, rainfall, temperature, clay soil, stone soil, soil depth, water-logging, and other diseases and insect pests. Of them soil depth and rainfall negatively, and others positively related with the severity of disease. Accordingly, a linear multiple regression model was derived, which might predict the developmental level of decline disease at any given conditions of exotic pine plantation. In addition, the spiral chart of decline disease was mapped based on the action size and time order of various nosogenetic factors during the incidence of decline disease, which was used to visually describe and quantitatively analyze the disease with complicated causes.

Causality↗
PubMed2001

[Photobacterium phosphoreum assay on the toxicity of soil contaminated by heavy metals].

The toxicity of soil artificially contaminated by heavy metals was assessed with Photobacterium phosphoreum. The results showed that the duration of optimum balance was 24 hours, and that of optimum extraction was 2 hours. Two leaching methods were compared, and data showed that optimum leaching solvent was hydrocarbon chloride with a concentration of 0.1 mol.L-1 HCL. Dose-response curve indicated that the content of heavy metals was positively related with the toxicity of soil. The general detection limit given by EC50 of soil contaminated by single heavy metal were Cd 26.12 mg.kg-1, Cu 291.48 mg.kg-1, Zn 72.46 mg.kg-1 and Pb 2174.93 mg.kg-1. This study also indicated the toxicity of complex heavy metals pollution in soil was stronger than that of individual element. The research could provide a theoretic base for the remediation of soil contaminated by heavy metals.

Cadmium↗
PubMed2001

[Analysis, prospect and treatment of causes of phacoemulsification complications].

OBJECTIVE: To analyse the causes of different complications of phacoemulsification and to investigate their principles of treatment and prevention. METHOD: The causes of different complications in 187 (180 cases) of 2,250 eyes having undergone phacoemulsification were analyzed. RESULTS: Intraoperatively, the common complications of phacoemulsification were posterior capsular rupture in 70 eyes (3.1%), iris damage in 16 eyes (0.7%), iris prolapse in 6 eyes (0.3%), drop of lens fragments into vitreous in 3 eyes (0.1%) and tear of Descernent's membrane in 4 eyes (0.2%). The common complications after the operation were corneal endothelial edema in 89 eyes (4.0%), corneal decompensation in 2 eyes (0.1%), temporary intraocular hypertension in 28 eyes (1.2%), pupillary dilatation in 7 eyes (0.3%), retinal detachment in 8 eyes (0.4%), cystoid macular edema in 24 eyes (1.1%) and displacement of intraocular lens in 8 eyes (0.4%). CONCLUSIONS: The different complications can be diminished following the popularization and development of phacoemulsification. It should be properly managed once the complication has occurred, and good operative effects can be obtained.

Eye Diseases↗
PubMed2001

Relationship of large multifunctional proteasome 7 gene polymorphism with susceptibility to type 1 diabetes mellitus and DR3 gene.

OBJECTIVE: To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population. METHODS: LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A < or = 14 years, group B 15-30 years, group C > or = 31 years. RESULTS: In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P < 0.05) and that of LMP7-B/A was higher (54% vs 31%, P < 0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P < 0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset. CONCLUSIONS: LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.

Adolescent↗
PubMed2001

[Phacoemulsification for short eye axis cataract].

OBJECTIVE: To analyze the operative difficulty of cataract phacoemulsification in an eye with shorter axial length and discuss its preventive measures. METHODS: A retrospective study was performed to analyze the 122 patients (143 eyes) who had undergone cataract phacomulsification. Their ocular axial lengths were 20.21 to 22.10 mm. RESULTS: Because these patients had shorter ocular axis, shallower anterior chamber depth, narrower space in the anterior ocular segment and higher vitreous pressure, the operation was hard to perform. The rate of posterior capsular rupture was 7.69%. The postoperative inflammatory reaction was severe. The rate of reversible corneal edema (29.37%) was obviously higher than that in cataractous eyes with normal ocular axis (6.7%, P < 0.01), and also higher than that in eyes with normal ocular axis and hard nucleus (12.5%, P < 0.05). CONCLUSIONS: It is emphasized that the correct technique of incision, application of chopping and breaking nucleus technique, lower energy and higher aspiration for effective phacoemulsification with the help of Viscoat viscoelastic material and maintenance of deep anterior chamber are the key procedures to obtain satisfactory operative results.

Adult↗