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Biomedical subjects

Z L Zhang

Publications and source records attributed to Z L Zhang.

At least 19 recordsLinked to original sources
PubMed2005

The SARS outbreak in a general hospital in Tianjin, China -- the case of super-spreader.

Severe acute respiratory syndrome (SARS) is a newly emerged infectious disease with a high case-fatality rate and devastating socio-economic impact. In this report we summarized the results from an epidemiological investigation of a SARS outbreak in a hospital in Tianjin, between April and May 2003. We collected epidemiological and clinical data on 111 suspect and probable cases of SARS associated with the outbreak. Transmission chain and outbreak clusters were investigated. The outbreak was single sourced and had eight clusters. All SARS cases in the hospital were traced to a single patient who directly infected 33 people. The patients ranged from 16 to 82 years of age (mean age 38.5 years); 38.7% were men. The overall case fatality in the SARS outbreak was 11.7% (13/111). The outbreak lasted around 4 weeks after the index case was identified. SARS is a highly contagious condition associated with substantial case fatality; an outbreak can result from one patient in a relatively short period. However, stringent public health measures seemed to be effective in breaking the disease transmission chain.

Adolescent↗
PubMed2004

Phase association of polycyclic aromatic hydrocarbons in the Minjiang River Estuary, China.

Persistent organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their persistence, bioaccumulation and toxic effects. In this work the levels of 16 priority PAHs were determined in water, pore water, sediment, soil and vegetable samples from Minjiang River Estuary, China. Total PAH concentrations varied from 9.9 to 474 microg/l in water, 82.1 to 239 microg/l in pore water, 112 to 877 ng/g dry wt. in surficial sediments, 128 to 465 ng/g dry wt. in soil and 8600 to 111,000 ng/g dry wt. in Chinese vegetables. Overall, the mean concentrations of PAHs were present in higher levels in pore water than that in surface water, due possibly to higher concentrations of dissolved organic carbon or colloids with which the hydrophobic pollutants were strongly associated. Such a concentration gradient implies a potential flux of pollutants from sediment pore water to overlying water. Contamination was dominated by high molecular mass PAH compounds in all samples, indicating combustion-derived sources (for example, pyrolysis at high temperature). The levels of PAHs in water and vegetable were relatively high in comparison to other studies, although PAHs in sediment and soil were comparable to those found in many other similar environments. The ratios of selected PAHs indicated again that PAHs in Minjiang River Estuary were mainly derived from incomplete combustion of fossil fuel.

China↗
PubMed2004

Growth of compound single- and multi-walled carbon nanotubes.

Single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) are complement to each other in many of their physical properties. We report the synthesis of carbon nanotube cables-a form of compound single- and multi-walled carbon nanotubes which could have the superior properties of both the SWCNTs and MWCNTs. This compound form of carbon nanotubes consists of a bundle of SWCNTs formed into a MWCNT, and the diameter of the inner most shell of the MWCNT ranges from a few to tens nanometers. The growth of these compound carbon nanotubes cannot be explained readily via existing modes of carbon nanotube growth, but promises a new way for improving and controlling the physical properties of either single- or multi-walled carbon nanotubes.

Journal Article↗
PubMed2004

Promoting of melanocyte adhesion and migration by Malytea Scurfpea fruit in vitro.

The aim of this study was to investigate the effect of Malytea Scurfpea Fruit (MSF) on melanocyte adhesion and migration. Human epidermal melanocytes were treated with MSF and examined for adhesion to bovine serum fibronectin-coated culture dishes. Control and treated cells were also examined for migration into micropore filters coated with the same protein. Compared with control, MSF-treated melanocytes adhered to the dishes more easily and migrated into the filters in a dose-dependent manner. MSF at a dose of more than 200 micro g/ml did not increase melanocyte adhesion and migration accordingly. With the exception of MSF 10 micro g/ml, at every concentration of MSF there were significant differences between treated and untreated melanocytes (p < 0.01) when the adhesion test was studied. Regarding migration, even at a concentration of MSF 10 micro g/ml, obviously increased cell numbers were found compared with MSF untreated melanocytes (p < 0.01). MSF promoted melanocyte adhesion and migration; this could explain, in part, the capacity of MSF to regulate melanocyte function in vitiligo.

Animals↗
PubMed2003

Fate and assessment of persistent organic pollutants in water and sediment from Minjiang River Estuary, Southeast China.

Persistent organochlorine compounds were analyzed in surface water, porewater and surficial sediment samples from Minjiang River Estuary, which is the first large river in Fujian Province, Southeast of China. The total concentrations of 18 organochlorine pesticides were 214.4-1819, 4541-13,699 ng/l, 28.79-52.07 ng/g in surface water, porewater and sediments (dry weight) respectively, and those of 21 polychlorinated biphenyls (PCBs) in the three phases were: 203.9-2473, 3192-10,855 ng/l, 15.14-57.93 ng/g respectively. The results showed that the concentrations of these selected organochlorine pesticides and PCBs in porewater were higher than those in surface water. It may be due to the fact that these organic hydrophobic pollutants tend to stay in the sediments, and then re-suspend from the sedimentary phase to the upper water. We have analyzed the distribution characteristics of individual organochlorine pesticide components and PCBs, and found that alpha-HCH, DDE, Heptachlor, Endosulfan II, Methoxychlor were the most common organochlorine pesticides contaminants. Considering the groups of HCHs (HCHs=alpha-HCH+beta-HCH+gamma-HCH+delta-HCH) and DDTs (DDTs=DDT+DDD+DDE), the predominance of beta-HCH, DDE in all water, porewater and sediment samples was clearly observed. This observation suggested that beta-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD, of which DDE that was more un-degradable. The PCB congeners containing 3-6 chlorines had the great preponderance in the three phase. These results were compared with those present in other estuaries and harbors. A risk assessment was evaluated for the persistent organic pollutants in the Minjiang River Estuary.

China↗
PubMed2002

Contamination by polycyclic aromatic hydrocarbons in the Jiulong River Estuary and Western Xiamen Sea, China.

The distribution of 16 polycyclic aromatic hydrocarbons (PAHs) was determined in water, sediment and pore water of the Jiulong River Estuary and Western Xiamen Sea, China. Total PAH concentrations varied from 6.96 to 26.9 microg/l in water, 59-1177 ng/ g dry weight in surficial sediments, and 158-949 microg/l in pore water. The PAHs were present in higher levels in pore water than in surface water, due possibly to higher concentrations of dissolved organic carbon or colloids with which the hydrophobic pollutants were strongly associated. Such a concentration gradient implies a potential flux of pollutants from sediment pore water to overlying water. The levels of PAHs in water and pore water were significantly higher than those found in 1998, suggesting recent inputs of these compounds into the area and re-working of sediment phase. The composition pattern of PAHs in the three phases was dominated by high molecular weight PAHs, in particular 5-ring PAHs. The salinity profile of dissolved PAHs suggested that they all behaved non-conservatively due to deviation from the theoretical dilution line. No correlation was found between PAH concentrations in sediment and those in pore water, and the correlation between the partition coefficients of PAHs and sediment organic carbon content was not significant, suggesting the complexity of the partition behaviour of PAHs. As a result of high PAH concentrations in water and pore water, it is likely that they may have caused mortality to certain exposed organisms.

China↗
PubMed2002

Occurrence and behaviour of organophosphorus insecticides in the River Wuchuan, southeast China.

Organophosphorus (OP) insecticides are used worldwide, yet their persistence in the environment is not well understood. This paper summarises recent research on 17 OP insecticides in the River Wuchuan, an important catchment in China, by determining their concentrations in water, soil, sediment and plants by gas chromatography with flame photometric detection (GC-FPD). The concentrations of the total OP insecticides ranged from 92.77 to 229 ng l-1 in river water, 1.61 to 9.93 ng g-1 dry weight in soil, 1.24 to 7.56 ng g-1 dry weight in sediment and 75.28 to 326 ng g-1 dry weight in plants. There was a relatively high abundance of methamidophos, dichlorvos, malathion, omethoate and dimethoate in all water, soil, sediment and plant samples. On average, these five compounds collectively accounted for 64%, 71%, 71% and 54% of the total OP insecticide concentration in water, soil, sediment and plants, respectively, which was similar to the composition of OP insecticides in application formulations used in our study area and in China as a whole. The results therefore reflect the application pattern to some extent, and suggest that the sources of the OP insecticides are mainly from current usage. When compared with other areas, the levels of OP insecticides in the River Wuchuan were moderate. The animal and human risks from exposure to OP insecticides in water and plants were evaluated against relevant threshold values. The results therefore provide important information on the current contamination status of a key agricultural watershed in China, and point to the need for urgent action to control the use of some excessively applied and potentially persistent agrochemicals, such as methamidophos, omethoate and dimethoate.

China↗
PubMed2001

[Expression of bcl-2 protein in uterine leiomyomas and normal myometrium].

OBJECTIVE: To study the expression of the apoptosis regulatory protein bcl-2 in the uterine leiomyomas and in the normal myometrium. METHODS: The expression of bcl-2 protein was examined by immunohistochemical ABC staining in 40 cases of uterine leiomyomas and normal myometrium. RESULTS: bcl-2 expression was higher in the uterine leiomyomas than that in the normal myometrium, both in the proliferative phase and in the secretory phase of the menstrual cycle (P < 0.01); bcl-2 expression in leiomyomas in the secretory phase was stronger than that in the proliferative phase of the menstrual cycle (P < 0.01). CONCLUSIONS: The increase of apoptosis inhabiting gene bcl-2 may play an important role in the growth of the uterine leiomyomas. This action may be regulated by progesterone.

Adult↗
PubMed2001

[Effects of running armored car on dynamic posture equilibrium].

Objective. To study the effects of training in running armored car on dynamic posture equilibrium. Method. Dynamic posture was tested pre- and post running armored car in 56 healthy men. Result. Compared to pre-training, certain equilibrium scores of sensory organization test condition 1 (P<0.05), 2 (P< 0.001), and 3 (P< 0.001) decreased significantly, while those of condition 4 (P<0.001) and 6 (P< 0.001) increased significantly. The static proprioception score (SOT2/SOT1 x 100) (P< 0.01) decreased significantly, while visual sensory score (SOT4/SOT1 x 100, P <0.01) and dynamic proprioception (SOT (4+5+6)/SOT(1+2+3) x 100, P<0.001) increased significantly post-training. The motor strategy scores of sensory organization test condition 2 (P<0.01) and 3 (P<0.001) significantly decreased. Conclusion. The results demonstrated that training in a running armored car influenced postural equilibrium and sensory organization.

Adult↗
PubMed2001

[Studies on fatty oils in yolk oil processed by different methods].

OBJECTIVE: To investigate the influence of different processing methods on fatty oils in yolk oil. METHOD: The contents of fatty oils and fatty acids were determined by ROESS GOTTILE and GC respectively, and the physicochemical properties of fatty oils were identified by pharmacopoeial method. RESULTS AND CONCLUSION: The yolk oils processed by daking and dry distillation are almost similar in the contents of fatty oils, type of fatty acids, acid value, iodine value, saponification value, relative density and refractive index, while obvious differences were found in the products processed by chloroform extraction.

Egg Yolk↗
PubMed2001

[Clinical observation on small doses Tripterygium wilfordii polyglycoside combined with methotrexate in treating rheumatoid arthritis].

OBJECTIVE: To observe the effect and adverse reaction of small doses Tripterygium wilfordii polyglycoside (TWP) combined with methotrexate (MT) in treating rheumatoid arthritis (RA). METHODS: Seventy RA patients were randomly divided into two groups, the control group (35 patients) and the TWP combined MT Group (TWPM group). Both of them were continued to use the non-steroidal anti-inflammatory drugs. The control group took MT 15 mg orally, once every week; the TWPM group took TWP 10 mg orally, 3 times a day, and MT 7.5 mg orally once every week. The clinical effect and adverse reaction after treatment were evaluated. RESULTS: The markedly effective rate in the control group and the TWPM group was 28.6% and 34.3% respectively, with no significant difference (P > 0.05). Data of symptoms and signs, erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) were determined respectively with significant difference (P < 0.01). The rate of adverse reaction was 20 cases-times in the control group and 8 cases-times in the TWPM group. CONCLUSION: MT combined small doses of TWP in treating RA has better effect and less adverse reactions than un-combined MT.

Adult↗
PubMed2001

[Effect of huangqi zengmian powder on interstitial response in patients with esophageal cancer at peri-operational period].

OBJECTIVE: To observe the effect of Huangqi Zengmian Powder (HQZMP) on interstitial response of esophageal cancer at peri-operational period. METHODS: Thirty-seven patients of esophageal cancer were treated with HQZMP for 4 weeks peri-operationally. The pathological interstitial changes (including mastocyte, microvessels and lymphocytic response) in resected esophageal cancer sample were observed using toluidine blue stain. RESULTS: As compared with the non-HQZMP treated control group, quantity of interstitial mastocyte, focal lymphocytic aggregation and interstitial microvessel damage in the HQZMP treated group were more obvious (P < 0.01). CONCLUSION: HQZMP could improve the immune function of esophageal patients in peri-operational period.

Adjuvants, Immunologic↗
PubMed2001

[Fluorescence development of blood fingerprint].

In this article we compared benzidine with derivative methods of developing blood fingerprint and put forward a new fluorescence method. Combination and nature were briefly discussed. Blood fingerprint was developed distinctly through strong oxidation agent destroying ferroheme, depositing pearl protein by blood stain activation and protein decoration method. Fifteen fluorescence agents for developing latent blood fingerprint were exploited. Development theory of blood fingerprint was discussed systematically, including all kinds of affected factors of blood fingerprint fluorescence development. The method, main characteristics and developing effect of blood stain activation and protein decoration for developing blood fingerprint were explained.

Benzidines↗
PubMed2000

Stability of carbon nanotubes: how small can they be?

Experimental evidence has been found for the existence of small single wall carbon nanotubes with diameters of 0.5 and 0.33 nm by high resolution transmission electron microscopy, and their mechanical stability was investigated using tight-binding molecular dynamics simulations. It is shown that, while the carbon tubes with diameters smaller than 0.4 nm are energetically less favorable than a graphene sheet, some of them are indeed mechanically stable at temperatures as high as 1100 degrees C. The 0.33 nm carbon tube observed is likely a (4, 0) tube and is indeed part of a compound nanotube system that forms perhaps the smallest metal-semiconductor-metal tubular junction yet synthesized.

Journal Article↗
PubMed2000

The inhibitory mechanisms of amlodipine in human vascular smooth muscle cell proliferation.

The abnormal proliferation of vascular smooth muscle cells (VSMCs) is closely related to vascular diseases. There is growing evidence that calcium antagonists inhibit VSMC growth/proliferation, yet their molecular mechanisms remain to be determined. Recent reports suggest that p42/p44 mitogen-activated protein kinases (MAPKs) play an important role in cell growth and proliferation induced by growth factors. This study was designed to determine whether these MAPKs are involved in VSMC proliferation induced by basic fibroblast growth factor (bFGF) and to examine the inhibitory effect of amlodipine. Human VSMCs were obtained from inner mammary artery. p42/p44 MAPKs activity was measured by immunoblotting assay using anti-p42/p44 phospho-MAPK antibody. 1) bFGF (20 ng/ml) significantly activated p42/p44 MAPKs with a peak time of 5-15 min, which was maintained for 3 h. PD98059 (100 nM-10 microM), a specific inhibitor of MAPK kinase, inhibited bFGF-induced p42/p44 MAPKs activation in a dose-dependent manner. 2) Amlodipine (1-100 nM) dose-dependently inhibited p42/p44 MAPKs activation by bFGF. 3) Amlodipine (10 nM) could inhibit both short-term and long-term p42/p44 MAPKs activation by bFGF. Our results indicate that bFGF could activate p42/p44 MAPKs. Amlodipine, which could inhibit bFGF-induced human VSMC proliferation, inhibited both short-term and sustained p42/p44 MAPKs activation by bFGF, suggesting that bFGF-induced VSMC proliferation may be related to p42/p44 MAPKs activation, and that the antiproliferative effect of amlodipine may be related to its inhibition of p42/p44 MAPKs activation.

Amlodipine↗
PubMed2000

[Expression of Bacillus thuringiensis (Bt) crystal toxin gene in the chloroplast of tobacco].

The 3.5 kb wild-type Bt Cry I A(c) gene and its 3' truncated forms (2.1 kb, 1.8 kb) were placed under the control of plastid expression signals consisting of the strong light-induced psbA promoter and its 3' untranslated region with the aadA cassette (Prrn, aadA and psbA3') as a selectable marker. The resulting vectors pBT3, pBT8 and pBT22 also contain flanking tobacco plastid DNA homology regions to direct insertion of the Bt transgene into the tobacco plastid genome between psbA and trnK by homologous recombination. Transformed plastid genomes were selectively amplified by growing the cells on spectinomycin medium. Several independently transformed lines were obtained at last. The results of Southern and Western blot demonstrated that these three kinds of Bt genes had been introduced into tobacco plants, and their filial generations are resistant to spectinomycin. Insecticidal activity assay with transgenic tobacco leaves indicate that some plants have strong toxicity to cotton bollworm. This is the first report in China that Bt gene has been introduced and successfully expressed in the chloroplast of higher plants.

Bacillus thuringiensis Toxins↗
PubMed2000

[Determination of catechins in grape seeds by capillary electrophoresis].

A capillary zone electrophoresis (CZE) method has been developed for the determination of four pharmacologically active catechins in grape seed. The components analyzed were (+)-catechin, (-)-epicatechin, epigallocatechin and epicatechin gallate. Separation was achieved by using a mixed buffer of 0.02 mol/L borate and 0.005 mol/L phosphate at pH 10.0 as background electrolyte and an uncoated fused silica capillary with 50 microns i.d. x 375 microns o.d. (effective length 41.5 cm) maintained at 25 degrees C. The applied voltage was 25 kV, and detection was performed by DAD at wavelength of 210 nm. By using proposed CZE method, four catechins were well separated within only 10 minutes with the repeatability of < 1% RSD for migration time and < 5% RSD for peak area. Correlation coefficients better than 0.995 were obtained within the concentration range from 0.005 g/L to 0.5 g/L for the four analytes studied with the detection limit of 3 mg/L-10 mg/L. The contents of these compounds in ten species of grape seeds cultivated in China were successfully determined.

Catechin↗