Biomedical subjects

Z Fang

Publications and source records attributed to Z Fang.

At least 55 records · Page 3Linked to original sources

PubMed2001

Sensitization to silk and childhood asthma in rural China.

OBJECTIVE: Sensitization to perennial aeroallergens is associated with asthma in industrialized countries with a Western lifestyle. Because silk products are commonly used in Chinese society, we were interested in examining the relation between sensitization to silk and asthma. DESIGN: Cross-sectional study of 871 children in 503 families living in Anqing, a predominantly rural province of China. RESULTS: After adjustment for age, gender, familial correlations, and sensitization to other aeroallergens, skin test reactivity to silk was an independent predictor of asthma (odds ratio = 2.6; 95% confidence interval = 1.2-5.7). This association became stronger after inclusion of the eosinophil count and history of parasitic diseases of the participants in the multivariate model (odds ratio = 3.6; 95% confidence interval = 1.4-8.9). CONCLUSION: Because sericulture is an important activity in China and other countries throughout the world, sensitization to silk may influence the pathogenesis and severity of asthma in people living in these nations.

Allergens↗

PubMed2001

Loss of nm23 expression predicts distal metastases and poorer survival for breast cancer.

The nm23 gene, originally identified by differential hybridization of metastatic murine melanoma cell lines has been associated with decreased metastatic potential. In this study, we evaluated the utility of nm23 expression levels as a predictive and a prognostic biomarker for distal metastases and poor survival in a Chinese cohort of 168 breast cancer patients. Our study indicates that high nm23 expression is associated with older age (older than 35 years) and smaller tumor size. There is no statistically significant association between nm23 expression and pathologic type or axillary metastasis. High nm23 expression is associated with the absence of distal metastases. Nearly 80% of women with high nm23 expression are alive after 10 years compared to 25% with low expression; at five years the cumulative survival proportions are 86% and 46%, respectively. The Cox model for survival indicates that controlling for tumor size and presence of axillary metastases at diagnosis, the hazard for women with low nm23 expression is nearly 4 times that of women with high nm23 expression. Low nm23 expression is predictive of distal metastases and appears to be a risk factor that is independent of the presence or absence of positive axillary nodes at diagnosis.

Adult↗

PubMed2001

[Comparison between porous polymer carrier and activated carbon carrier used for treating organic wastewater in anaerobic fluidized-bed reactor].

A comparative performance between porous polymer carriers (HP) and granular activated carbon carriers (GAC) in anaerobic fluidied-bed reactors was undertaken to evaluate their characters. The results showed that the COD removal and the biogas volume yield rate were 84% and 16.5 m3/(m3.d) respectively when HP was used as carrier to treat synthetic wastewater, at the top COD organic load rate of 65.5 kg/(m3.d), however those were 74.2% and 14.5% respectively for GAC carrier at the top load rate of 63.25 kg/(m3.d). The COD removal and biogas volume yield rate were 64.7%-54.5% and 1.89-2.7 m3/(m3.d) respectively when HP was used as carriers to treat straw pulping wastewater, at the load rate of 14.5-36.15 kg/(m3.d), and those were 61.0%-52.1% and 0.73-2.0 m3/(m3.d) respectively for GAC carriers at the load rate 9.16-19.06 kg/(m3.d). The study revealed that the HP carriers reactor is more efficient than the GAC carriers reactor in microbial immobilization and the wastewater treatment.

Anaerobiosis↗

PubMed2001

[Study on p53 gene mutation in hepatocellular carcinoma patients in China].

OBJECTIVE: To study p53 gene mutation in human hepatocellular carcinoma (HCC) samples and the relationship between p53 gene mutation and hepatitis B virus (HBV) infection. METHODS: DNA samples were prepared from 50 specimens of HCC patients that had been infected with HBV. Exons 5-9 were amplified with polymerase chain reaction (PCR), and then detected by single strand conformation polymorphism (SSCP). RESULTS: Over 26% (13/50) of p53 DNA samples were found to be mutated, mainly in exons 5-8 relating to 3,3,4,3 cases respectively and along with 4 suspicious samples. CONCLUSION: p53 gene mutation might be one of the causes of HCC, and HBV infection may be associated with such mutation in China.

Adolescent↗

PubMed2001

[The development of multi-lead EEG telemetry and tele-monitoring system].

This paper introduces a kind of EEG Telemetry and Tele-monitoring system. With the use of the public telephone network to transport signals and the portable EEG recording system as the sender of system, the EEG data of 20 standard leads can be transmitted to the receiver of system (monitoring center) synchronously. And at the monitoring center, the waves can be displayed real-time, freezing, stored, reviewed, analyzed and printed, thus providing aid in remote diagnosis and treatment consultations.

Computer Communication Networks↗

PubMed2001

Adsorption of acetanilide herbicides on soil and its components. II. Adsorption and catalytic hydrolysis of diethatyl-ethyl on saturated Na(+)-, K(+)-, Ca(2+)-, and Mg(2+)-montmorillonite.

Adsorption and catalytic hydrolysis of the herbicide diethatyl-ethyl [N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester] on homoionic Na(+)-, K(+)-, Ca(2+)-, and Mg(2+)-montmorillonite clays were investigated in water solution. The Freundlich adsorption coefficient, Ki, got from isotherms on clay followed the order of Na+ approximately K+ > Mg2+ approximately Ca2+. Analysis of FT-IR spectra of diethatyl-ethyl adsorbed on clay suggests probable bonding at the carboxyl and amide carbonyl groups of the herbicide. The rate of herbicide hydrolysis in homoionic clay suspensions followed the same order as that for adsorption, indicating that adsorption may have preceded and thus caused hydrolysis. Preliminary product identification showed that hydrolysis occurred via nucleophilic substitution at the carboxyl carbon, causing the cleavage of the ester bond and formation of diethatyl and its dechlorinated derivative, and at the amide carbon, yielding an ethyl ester derivative and its acid. These pathways also suggest that hydrolysis of diethatyl-ethyl was catalyzed by adsorption on the clay surface.

Acetanilides↗

PubMed2001

Effects of free radicals and amyloid beta protein on the currents of expressed rat receptors in Xenopus oocytes.

OBJECTIVE: To investigate the effects of free radicals (FRs) and amyloid beta protein 1-40 (A beta 1-40) on the functions of expressed neurotransmitter receptors (NRs) in Xenopus oocytes. METHODS: Total RNA and messenger RNA (mRNA) was prepared from 3-month-old Wistar rat brain tissues with Promega kits and microinjected into maturated Xenopus oocytes (stages V-VI) with 50 nl (50 ng) for each oocyte. The microinjected oocytes were incubated with modified Bath's solution at 19.0 degrees C +/- 1.0 degree C for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) were produced via a reaction system (HPX/XO) with hypoxanthine (HPX, 0.05 mol/L) and xanthine oxidase (XO, 0.1 U/L). In order to observe the effects of A beta and SAFRs on the expressed glutamate receptor, HPX/XO and A beta 1-40 were added to incubation solution at 12 h, 24 h and 96 h before recording. RESULTS: The results showed that the oocytes expressed functional NRs originating from rat brain tissues. These NRs included muscarinic acetylcholine (mACh), glutamate (Glu), dopamine (DA), serotonin (5-HT) and gamma-aminobutyric acid (GABA). The current characteristics of expressed receptors were inward currents carried by chloride ion with their equibrilium potentials close to -22 mV. The extent of effect on the current of expressed glutamate receptor from rat brain was different among different A beta concentrations and incubation times. A beta 1-40 at a concentration of 20 nmol/L had little effect on the currents of expressed rat brain glutamate receptors up to 24 h of incubation period; but the currents of glutamate receptor were significantly decreased (25% off, P < 0.01) in the treatment of 60 nmol/L A beta 1-40 over 24 h. Moreover, when 20 nmol/L A beta 1-40 was co-incubated over 12 h with SAFRs produced by the reaction system of HPX/XO, it was found that the currents of expressed rat brain glutamate receptors had been changed markedly. When the oocytes were co-treated with 60 nmol/L A beta 1-40 and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% off, P < 0.05), and the decreased percentage reached 52% over 24 h co-treatment with 60 nmol/L A beta 1-40 and SAFRs. In addition, vitamin E had a partial effect against this inhibitory effect. CONCLUSION: The results suggest that A beta has a kind of inhibitory effect upon the current of the glutamate receptor, similar to the effects of free radicals. The effects can be antagonized by vitamin E. These imply that A beta may play a role via inhibiting receptor function in the pathophysiology of Alzheimer's disease.

Amyloid beta-Peptides↗

PubMed2001

Immune responses to the expressed products of the CSP antigen gene of plasmodium falciparum southern China isolate FCC1/HN in Hela cell.

OBJECTIVE: To construct a eukaryotic expression system with pcDNA3-PfCSP/Hela for the Circumsporozoite protein (CSP) gene of Plasmodium falciparum (P. falciparum), to observe the immune responses in BALB/c mice induced by the expressed proteins. METHODS: The recombinant plasmid pcDNA3-PfCSP was transformed into the Hela cell line. The expressed protein was isolated and analyzed by using SDS-PAGE and used for immunization of BALB/c mice by subcutaneous, intravenous, and intraperitoneal administration. Enzyme-linked immunosorbent assay (ELISA), Dot-ELISA, Western blot, T lymphocyte proliferation test, natural killer cell (NKC) activity assay, and CD4+ and CD8+ T cell detection were used for observation of humoral and cellular immune responses. RESULTS: Immune sera strongly reacted with the expressed protein, antibody titer was up to 1:6400 as detected by ELISA. Western blot analysis revealed a specific band at 38.3 Kda. When the spleen cells of normal and immunized BALB/c mice were specifically stimulated with expressed protein, the optical densities were 0.12 +/- 0.03 and 0.34 +/- 0.04, respectively. The latter were significantly higher than the former (P < 0.01). We used the MTT colorimetric assay to measure NKC activity of mice spleen. The results showed that the NKC activity of immunized BALB/c mice was remarkably higher than that of the controls (P < 0.05). CD4+ and CD8+ T cells were detected by using monoclonal antibody immunofluorescence methods. The results showed that the percentage of CD4+ and CD8+ T cells of immunized group were significantly higher than that of control group (P < 0.05). CONCLUSIONS: The humoral and cell-mediated immune responses and elevated NKC activity to products made with a eukaryotic expression system could be specifically detected in BALB/c mice. These findings indicate that the expressed protein could enhance the immune function in mice.

Animals↗

PubMed2001

[A comparison of the effects of PAV, PSV and IPPV on cardiopulmonary function in patients with acute respiratory failure].

OBJECTIVE: Comparing the effects of proportional assist ventilation (PAV), pressure support ventilation (PSV), and intermittent positive pressure ventilation (IPPV) on cardiopulmonary function in patients with acute respiratory failure, in particular, evaluating the clinical significance of PAV. METHODS: Ten patients with acute respiratory failure were firstly ventilated with IPPV. Elaslance (Ers) and Resistance (Rrs) were measured and calculated. Then PSV mode was adapted. Based on the parameters of IPPV, inspiratory positive airway pressure was adjusted to maintain the same tidal volume (V(T)) as that in IPPV. Finally PAV mode was used. According to the parameters of PSV, the assist ratio was adjusted to maintain the same V(T) and peak pressure peak, as those in PSV. Respiratory mechanics, arterial blood gas and hemodynamics were recorded during above three modes of ventilation. RESULT: Comparing with PSV and IPPV mode, PAV created a significantly lower peak, less work of breathing of patients (WoBp) and work of breathing of ventilation (WoBv) under the similar V(T); Central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) were significantly lower in PAV mode as compared with those in IPPV; While comparing with PSV, V(T), mean blood pressure (mBP) and cardiac output (CO) were higher and mean pulmonary arterial pressure (mPAP), WoBp were lower in patients with PAV under similar peak. Among them the fall of WoBp was statistically significant. CONCLUSION: In patients receiving three modes of ventilation, PAV presents with lower airway pressure, less WoBp and less effect on hemodynamics as compared with those with PSV or IPPV.

Acute Disease↗

PubMed2001

[The predomination of rotavirus G3 serotype among children with diarrhea in Lulong County in 1998].

OBJECTIVE: To investigate the epidemiology of rotavirus diarrhea among children in rural population. METHODS: 120 stool specimens collected from children with diarrhea during the winter of 1998 in Lulong County, Hebei Province were examined for rotavirus by PAGE and ELISA and for serotype by ELISA and PCR. RESULTS: Rotavirus was detected in children aged between 2-24 months. The positive rate of rotavirus was 39.2% and the ratio of male to female was 1-1.47. All rotavirus RNA profiles were long pattern. The distribution of rotavirus serotypes was type 3(61.7%), followed by type 1(36.2%), and type 4(6.4%). CONCLUSIONS: The epidemiology of rotavirus diarrhea during 1998 rotavirus season in Lulong County was similar to that of other regions in China, but rotavirus serotype G3 was a prevalent strain in Lulong County, which was uncommon and different from the predominant G1 in other places throughout China.

Child, Preschool↗

PubMed2001

[Expression of bcl-2 and Bax genes in facial neurons and their regulation of neuron apoptosis following facial neurotmesis in rats].

OBJECTIVE: The aim of this study is to investigate the relationship between the expression changes of bcl-2 and Bax genes and their functions in facial neuronal apoptosis after amputating the facial nerve. METHODS: Rats were randomized into two groups, including the experimental and the control group. The changes of expression of bcl-2 and Bax genes in the facial neurons and facial neuronal apoptosis were observed after the facial nerve amputation using the methods of ABC immunohistochemical staining and TUNEL. RESULTS: The expression of bcl-2 and Bax genes and the apoptosis of facial neurons were significantly higher in the experimental group than those of the control group from the 3rd to 21st day after amputation, but the bcl-2/Bax significantly decreased compared with that of the control group. CONCLUSION: This indicated that bcl-2 and Bax might play an important regulation role in the process of facial neurons apoptosis following facial nerve amputation.

Animals↗

PubMed2001

[The effects of long-term domiciliary oxygen therapy on patients of chronic obstructive pulmonary disease with hypoxaemia].

OBJECTIVE: To observe the effects of long-term domiciliary oxygen therapy (LTDOT) on patients of chronic obstructive pulmonary disease (COPD) with hypoxaemia. METHODS: Sixty-one hypoxemic cases with stable COPD were divided into two groups--the LTDOT group of 30 patients and the control group of 31 patents. Before LTDOT and one year or two years later, the lung function test, blood routine, electrocardiography and ultra-echocardiography were tested, the psychological status and quality of life (QOL) were evaluated with the hospital anxiety and depression score and QOL questionnaire respectively. Both groups received routine treatment. In addition,the LTDOT group received oxygen therapy at home with nasal cannula with the oxygen flow of (0.5 - 2.5) L/min for at least 15 hrs every day. RESULTS: Thirteen patients in the LTDOT group died two years later, the mortality rate was 43%; eleven patients in the control group died. In LTDOT group hemoglobin, red blood cell count and hematocrit did not change after one year and two years, the hemoglobin, red blood cell count and hematocrit in the control group did not change after one year but the hemoglobin and red blood cell count increased significantly after two years (P < 0.05); ECG showed that the value of RV1 + SV5 in the LTDOT group remained stable (P > 0.05), which in the control group increased (P < 0.05). After one year and two years, mean pulmonary artery pressure in the LTDOT group declined significantly (P < 0.05). The internal diameter of right ventricle of the heart and the outlet of right ventricle of the heart declined significantly (P < 0.05), but those in the control group increased significantly (P < 0.05). In the LTDOT group, the anxiety and depression scores were significantly improved (P < 0.05) after one year or two years, the total mean score of QOL, general activity score, social activity score, depression and anxiety scores were significantly improved (P < 0.05), but in the control group the anxiety and depression scores did not change (P > 0.05), the total mean score of QOL, social activity score, the anxiety score were significantly worse(P < 0.05). CONCLUSIONS: Long-term domiciliary oxygen therapy could reduce the load of the right heart, improve the patients's psychological status and quality of life.

Aged↗

PubMed2001

[The efficacy of controlling of house dusts in attacks of mite sensitive asthmatics].

OBJECTIVE: To study the effect of controlling of house dusts in attacks of mite sensitive asthmatics (DMSA). METHODS: Dust in mattresses, sofas, beddings and pillows were calculated for 43 cases of DMSA every season meanwhile the asthmatic symptoms, amount of drugs taken, PEF value in morning and evening were daily recorded by patients, then the patients were divided into two groups i.e. treatment group (A group, 22 cases) and no treatment group ( B group, 21 cases) randomly. The controlling measures included well-ventilation, washing clothes and bedclothes and catching dust frequently and exposing of clothing or bedclothes in the sun. RESULTS: Correlation was found between house dust density and asthmatic attacks. The number of dust mites was lower after treatment than before in A group [(N/g): spring 62 vs 103, summer 105 vs 132, autumn 163 vs 231, winter 9 vs 13]. Concomitant asthmatic symptoms and amount of drugs taken and total IgE reduced [(0.6 vs 1.6) mg/L] and PEF values or PEF difference improved. CONCLUSION: Control of dust mites growth could alleviate the asthmatic symptoms and decrease the attacks.

Adolescent↗

PubMed2000

Ferromagnetism stabilized by lattice distortion at the surface of the p-wave superconductor Sr(2)RuO(4)

Ferromagnetic (FM) spin fluctuations are believed to mediate the spin-triplet pairing for the p-wave superconductivity in Sr(2)RuO(4). Our experiments show that, at the surface, a bulk soft-phonon mode freezes into a static lattice distortion associated with an in-plane rotation of the RuO(6) octahedron. First-principle calculations confirm this structure and predict a FM ground state at the surface. This coupling between structure and magnetism in the environment of broken symmetry at the surface allows a reconsideration of the coupling mechanism in the bulk.

Journal Article↗

PubMed2000

Phase diagram of tetragonal manganites

The phase diagram of La1-xSrxMnO3, as a function of hole doping x and tetragonal distortion c/a, which consists of ferromagnetic (FM), A-, C-, and G-type antiferromagnetic (AF) states, is obtained by the first-principles band structure calculations. Effects of tetragonal distortion on the magnetic ordering are discussed in terms of orbital ordering and anisotropy in the hopping integrals. The general sequence of the magnetic ground states, FM --> A-AF --> C-AF --> G-AF with increasing of x, is also explained based on the instability of FM states with respect to the spin-wave excitations.

Journal Article↗

PubMed2000

Identification of the subcellular localization of daunorubicin in multidrug-resistant K562 cell line.

We examined the subcellular distribution of daunorubicin (DNR) in resistant K562 cell line which overexpress the P-glycoprotein by confocal laser scanning microscopy. Three fluorescent probes - Rhodamine123, neutral red, NBD-ceramide, which stain the mitochondria, lysosomes, Golgi apparatus respectively, were used to identify the nature of the subcellular compartment sequestering daunorubicin. In sensitive k562 cell line, nuclear and cytoplasmic DNR fluorescence was intense and diffuse. In contrast, resistant K562 cell line showed a different DNR distribution. A bright fluorescence signal was located in the perinuclear region and peripheral plasma, the nucleus and other cytoplasmic region appear as empty, as suggested by the distribution of fluorescent probe Rhodamine123 specifically for mitochondria. Verapamil, an effective resistance modulator in P-glycoprotein MDR cells, restored the DNR distribution closer to that in the parent cells. Golgic inhibitor brefeldin A and lysosomotropic agent chloroquine had little effect on drug sequestration. Our studies demonstrate that daunorubicin may be sequestered in mitochondrial compartment in the resistant cells and P-glycoprotein plays an important role on mediating DNR transport.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

The direction of microsatellite mutations is dependent upon allele length.

Microsatellites, comprising tandemly repeated short nucleotide sequences, are ubiquitous in eukaryotic genomes. Mutations within microsatellites are frequent, altering their overall length by insertion or deletion of a small number of repeat units, with a rate as high as 10(-3) in humans. Despite their high mutability, stable allele frequency distributions are typically observed for microsatellites in humans as well as other primates, although the mechanism maintaining these stable distributions remains unclear. Previous studies have suggested that microsatellite mutations occur more frequently in longer alleles and favour expansion. Generalizing these results has been hindered because the sample sizes were small, only a small subset of alleles for any marker was studied and the direction of mutation (expansion or contraction) was not rigorously determined. Here we examine 236 mutations at 122 tetranucleotide repeat markers and find that the rate of contraction mutations increases exponentially with allele size, whereas the rate of expansion mutations is constant across the entire allele distribution. The overall rate of expansion mutations does not differ from that of contractions. Our findings offer an explanation for the stationary allele distribution of microsatellites.

Alleles↗

PubMed2000

Nicotine dependence and its familial aggregation in Chinese.

BACKGROUND: Nicotine dependence is a significant public health problem. This study attempted to characterize the prevalence and familial aggregation of nicotine dependence in China. METHODS: In 1998, we initiated a community-based cross-sectional study among residents of the Yuexi County in Anqing, China. A total of 991 current smokers from 488 randomly selected nuclear families were recruited and surveyed by use of the standardized Fagerstrom Test of Nicotine Dependence (FTND) questionnaire and the Revised Tolerance Questionnaire (RTQ). All study subjects were offspring in their respective nuclear families, and 478 male-male pairs (aged 41.7 +/- 12.1 years) were finally used for data analyses, because the number of female current smokers (n = 5) was too small. RESULTS: The correlation coefficient of the FTND and the RTQ scores was as high as 0.84 (P < 0.0001). Nicotine dependence, defined as an FTND score > or =8 or an RTQ score > or =28, had a prevalence of 12.7% and 11.1%, respectively. The respective sibling recurrent risk was 1.7 and 2.4, according to the FTND or the RTQ criteria. The adjusted odds ratios and 95% CI of nicotine dependence of second siblings in families in which the first sibling was nicotine dependent were 2.13 (95% CI: 1.02-4.43) and 3.50 (95% CI: 1.65-7.36) respectively, according to the FTND and RTQ criteria. CONCLUSIONS: The prevalence of nicotine dependence in male current smokers in China was comparable to that reported in previous US and European studies. Our findings suggest that genetic influences may play an important role in vulnerability to nicotine addiction.

Adult↗