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Biomedical subjects

J G Wang

Publications and source records attributed to J G Wang.

At least 19 recordsLinked to original sources
PubMed2006

Role of Au(+) in supporting and activating Au(7) on TiO(2)(110).

The adhesion properties and catalytic activity of rutile TiO(2)(110)-supported Au(7) nanoclusters in different oxidation states are investigated by means of density functional theory. The calculations cover both surface science conditions of reduced TiO(2) and real catalyst conditions of oxidized (alkaline) TiO(2) supports. Large adhesion energies of Au(7) are found only when modeling real catalysts where the cluster becomes cationic with Au(+) ions in Au-O or Au-OH bonds. The full catalytic cycle for oxidation of CO by O(2) over Au(7) on alkaline TiO(2)(110) is calculated and found to involve only small activation barriers. In the presence of the CO reductant, the Au(+) sites are capable of cycling between bonding of atomic and molecular oxygen. We confirm our findings by comparison of calculated and experimental infrared stretch frequency data for adsorbed CO.

Journal Article↗
PubMed2006

Density functional theory study of water dissociation in a double water bilayer with or without coadsorption of CO on Pt(111).

Using density functional theory, we investigate the structure of the double water bilayer with or without coadsorption of CO on Pt(111). The double water bilayer consists of two bilayers. Each bilayer is buckled with every second water molecule being closer to the surface than every other water molecule. CO is found to adsorb most strongly when substituting in the first bilayer, the water molecule closest to the surface. Dissociation of H2O in the water bilayer (with or without CO) is further considered. A great number of pathways for the dissociation are studied. These include homolytic pathways where both dissociation products end up adsorbed on the Pt surface and heterolytic pathways where only the OH is adsorbed, while a proton is transferred to the water adlayers. We find that the heterolytic dissociation pathways are energetically more favorable than the homolytic ones, yet they are all rather endothermic. The most favorable pathways found have reaction energies of 0.60 and 0.52 eV without and with CO present. The corresponding activation energies are 0.99 and 0.53 eV, respectively.

Journal Article↗
PubMed2006

Redescription of Myxobolus pyramidis Chen, 1958(Myxosporea: Bivalvulida).

Redescription of Myxobolus pyramidis Chen, 1958, from gill lamellae of allogynogenetic gibel carp, Carassius auratus gibelio (Bloch), is presented in this paper to complete Chen's description. The diagnostic characters of the myxosporidia are: ovoid round, greyish-white polysporous plasmodia, averaging (159+/-21)x(72+/-6.5) mum in size; spore pyriform in front view with smooth surface and symmetrical valves, convex-shaped in sutural view with straight and thick sutural line, averaging (10.5+/-1.1)x(10.3+/-0.9)x(6.1+/-0.2) mum in size; two equal pyriform polar capsules averaging (5.5+/-0.7)x(3.5+/-0.2) mum in size with distinct intercapsular process and polar filament wounded in five to six coils. The histological effects of the pathogen were observed by light microscopy, and the parasite-host relationship was discussed.

Animals↗
PubMed2006

Familial characteristics of kidney-yang deficiency and cold syndrome.

Family investigation is a reliable model to study the effects of both genetic and environmental factors on human health. This article studies kidney-yang deficiency syndrome and cold syndrome through family investigation and cDNA microarray technology, exploring the effects of both genetic and environmental factors on the health of family members. Particularly, these two syndromes were first assessed by the accumulated clinical scores measured by 40-item scoring tables among 15 family members. The family patterns were obtained and the correlation of these two syndromes was determined. Then the gene differential expression profiles among 12 family members were obtained using an 18,816 clones cDNA microarray. The profiles of the patients with typical kidney-yang deficiency syndrome and cold syndrome were compared to those of normal members and 89 differential expression genes were found. Further, only 22 genes were identified as known functions, and most (16 genes) were associated with the regulation of metabolism, temperature feeling, and growth. Therefore, the formation and development of these two syndromes have not only genetic but also environmental factors, including living conditions and lifestyle.

Environment↗
PubMed2006

A combined phage display ScFv library against Myxobolus rotundus infecting crucian carp, Carassius auratus auratus (L.), in China.

Immunological methods have been developed for the diagnosis of Myxobolus rotundus but their use has been limited for the prevention and therapy of this serious parasitic pathogen. Phage display antibody libraries are a powerful technique for the development of antibodies to molecules of interest and have advantages over traditional hybridroma approaches. In the present study, four antigen fractions related to M. rotundus were prepared and a combined phage display single-chain antibody fragments (ScFv) library was constructed against this parasite. Preliminary analysis indicated that a combined antibody library of about 2.08 x 10(5) individual clones and high diversity was generated. After four rounds of screening (bio-panning) against soluble spore protein prepared from lysed, intact, mature M. rotundus spores, a strain monoclonal phage display ScFv, termed pCAN-6H9, with better affinity, was isolated. The pCAN-6H9 gene fragment was sequenced and analysed. The specificity of pCAN-6H9 was further demonstrated by dot-blot. In competition enzyme-linked immunosorbent assay, both the original and enriched phage-displayed ScFv repertoire showed significant inhibition of mouse anti-M. rotundus serum binding to coated antigen, while the inhibition rate of monoclonal pCAN-6H9 phage particles was only 11.83%.

Animals↗
PubMed2006

Clinical and molecular evaluation of warming and tonic herb treatment for sibling patients of a typical kidney-yang deficiency family.

It is essential to explore the molecular therapeutic effect of warm and tonic herb treatment for individuals with typical kidney-yang deficiency. In this report, we have identified members of a family with a history of suffering from cold and kidney-yang deficiency syndromes. First, we have employed the accumulated scores of the 40-items clinical scoring indicators for kidney-yang deficiency and cold syndromes to clinically assess the presence or absence of the deficiency for 15 family members. We then proceeded to compare the gene expression profiles of RNA isolated from blood samples, prior to and post-herbal treatment, of a sibling (brother and younger sister) that are suffering from the deficiency using cDNA microarrays with 18816 genes. Following treatments with the warming and tonic herb, the accumulated clinical scores obtained from the 40-items clinical scoring indicators were compared to those obtained pre-treatment. It was observed that the accumulated clinical scores were reduced by 1/3 for the brother and 2/3 for his younger sister following the treatments. Furthermore, we have demonstrated that the level of gene expression for a total of 33 genes at pre-treatment was modulated after treatments with the warming and tonic herb and correlated well with the clinical improvements of their syndromes. These results suggest that the combination of gene profiling and the accumulated clinical scores obtained from the 40-items clinical scoring indicators may provide an accurate clinical assessment and a way to monitor the therapeutic efficacy of the warming and tonic herb treatment.

Adolescent↗
PubMed2005

One-dimensional PtO2 at Pt steps: formation and reaction with CO.

Using core-level spectroscopy and density functional theory we show that a one-dimensional (1D) oxide structure forms at the steps of the Pt(332) surface after exposure. The 1D oxide is found to be stable in an oxygen pressure range, where bulk oxides are only metastable, and is therefore argued to be a precursor to the Pt oxidation. As an example of the consequences of such a precursor exclusively present at the steps, we investigate the reaction of CO with oxygen covered Pt(332). Albeit more strongly bound, the oxidic oxygen is found to react more easily with CO than oxygen chemisorbed on the Pt terraces.

Journal Article↗
PubMed2005

Humoral immune responses of the grouper Epinephelus akaara against the microsporidium Glugea epinephelusis.

The humoral immune responses of grouper Epinephelus akaara to a natural infection with Glugea epinephelusis was studied by ELISA utilizing intact mature spores as the coated antigen. Results showed that a specific humoral immune response was elicited, but the intensity of infection (in terms of the number of cysts) was not related to the antibody level in naturally infected hosts. The differences in the antigenicity of intact mature spores and soluble spore proteins derived from cracked mature spores were also analyzed. Results suggested that similar antigen epitopes existed between the 2 groups. Additionally, antigen component patterns and the distribution of antigen with immunogenicity were investigated by using the western blot and the immunofluorescent antibody technique (IFAT). The new parasitic microsporidium has specific polypeptide patterns comparable to the reported fish microsporidians. The main antigenic substances are concentrated on the surface of spores, and are mostly located on the anterior and posterior end of the spore bodies. Most surface components of the G. epinephelusis spores are soluble. The potential role of the surface components in initiating infection was also discussed.

Animals↗
PubMed2004

Target isotope effects for vibrationally-resolved electron capture in low-energy collisions of O3+ with molecular hydrogen.

Using a quantum-mechanical molecular-orbital coupled-channel (QMOCC) approach, we investigate single electron capture in collisions of O3+ with various molecular hydrogen isotopomers (H2, HD, T2) for collision energies of 1 and 100 eV u(-1). Potential energy surfaces and nonadiabatic couplings obtained with the spin-coupled valence-bond method are incorporated into QMOCC calculations of vibrationally-resolved cross sections of the product molecular ion. The infinite order sudden approximation is adopted and comparisons of the vibrational distributions are made with the centroid approximation, which incorporates ionization Franck-Condon factors. Intercomparison of the results is used to assess the reliability of the approximations and to give insight into the target isotope effects.

Journal Article↗
PubMed2001

[Detection of serum type IV collagen and the alteration of this collagen in various liver diseases].

OBJECTIVE: To detect serum Type IV collagen levels in patients with various hepatic diseases. METHOD: A sandwich enzyme-immunoassay, using two monoclonal antibodies to recognize 7S and TH of Type IV collage, was used to detect serum levels of Type IV collagen in 428 patients with various liver diseases. RESULTS: Serum levels of Type IV collagen in healthy control subjects were (63.2 +/- 31.9) microgram.L-1. Type IV collagen levels in the serum of patients with heavy hepatitis were the highest [(801.8 +/- 431.2) microgram.L-1]. All Types of hepatic diseases were significantly higher than those in healthy subjects (All P < 0.01). CONCLUSION: The assay used in this study is simple and practical and can be applied to clinical evaluation of hepatic fibrosis.

Adolescent↗
PubMed2001

Uniaxial cyclic stretch induces focal adhesion kinase (FAK) tyrosine phosphorylation followed by mitogen-activated protein kinase (MAPK) activation.

We investigated the role of tyrosine phosphorylation of FAK in the stretch-induced MAPKs (extracellular signal-regulated kinase (ERK), p38MAPK) activation in mutant FAK-transfected fibroblasts. In response to uniaxial cyclic stretch (1 Hz, 120% in length), the levels of tyrosine phosphorylation of the Tyr-397 and Tyr-925 of FAK in control cells increased and peaked at 5 min (2.75 +/- 0.51, n = 3), and 20 min (2.98 +/- 0.58, n = 3), respectively, and the activities of MAPKs increased and peaked at approximately 10 min. On the other hand, in the mutant FAK-transfected cells, the stretch-induced MAPKs activation was significantly inhibited. The stretch-induced activation of MAPKs was also significantly abolished by either treatment with Gd(3+) or extracellular Ca(2+) removal which may inhibit intracellular Ca(2+) increase caused by the activation of cation selective (Ca(2+)-permeable) stretch activated (SACatC) channels. These results suggest that the stretch-induced tyrosine-phosphorylation of FAK via SACatC activation is critical for the stretch-induced MAPKs activation.

Amino Acid Substitution↗
PubMed2001

Cardiovascular protection and blood pressure reduction: a meta-analysis.

BACKGROUND: Whether antihypertensive drugs offer cardiovascular protection beyond blood pressure lowering has not been established. We aimed to investigate whether pharmacological properties of antihypertensive drugs or reduction of systolic pressure accounted for cardiovascular outcome in hypertensive or high-risk patients. METHODS: In a meta-analysis we extracted summary statistics from published reports, and calculated pooled odds ratios for experimental versus reference treatment. We correlated across-trials odd ratios for differences in systolic pressure between groups. FINDINGS: We analysed nine randomised trials comparing treatments in 62605 hypertensive patients. Compared with old drugs (diuretics and b-blockers), calcium-channel blockers and angiotensin converting-enzyme inhibitors offered similar overall cardiovascular protection, but calcium-channel blockers provided more reduction in the risk of stroke (13.5%, 95% CI 1.3-24.2, p=0.03) and less reduction in the risk of myocardial infarction (19.2%, 3.5-37.3, p=0.01). Heterogeneity was significant between trials because of high risk of cardiovascular events on doxazosin in one trial, and high risk of stroke on captopril in another; but systolic pressure differed between groups in these two trials by 2-3 mm Hg. Similar systolic differences occurred in a trial of diltiazem versus old drugs, and in three trials of converting-enzyme inhibitor against placebo in high-risk patients. Meta-regression across 27 trials (136124 patients) showed that odds ratios could be explained by achieved differences in systolic pressure. INTERPRETATION: Our findings emphasise that blood pressure control is important. All antihypertensive drugs have similar long-term efficacy and safety. Calcium-channel blockers might be especially effective in stroke prevention. We did not find that converting-enzyme inhibitors or a-blockers affect cardiovascular prognosis beyond their antihypertensive effects.

Aged↗
PubMed2001

Efficacy of different drug classes used to initiate antihypertensive treatment in black subjects: results of a randomized trial in Johannesburg, South Africa.

BACKGROUND: Thiazides are recommended to initiate antihypertensive drug treatment in black subjects. OBJECTIVE: To test the efficacy of this recommendation in a South African black cohort. METHODS: Men and women (N = 409), aged 18 to 70 years, with a mean ambulatory daytime diastolic blood pressure between 90 and 114 mm Hg, were randomized to 13 months of open-label treatment starting with the nifedipine gastrointestinal therapeutic system (30 mg/d, n = 233), sustained-release verapamil hydrochloride (240 mg/d, n = 58), hydrochlorothiazide (12.5 mg/d, n = 58), or enalapril maleate (10 mg/d, n = 60). If the target of reducing daytime diastolic blood pressure below 90 mm Hg was not attained, the first-line drugs were titrated up and after 2 months other medications were added to the regimen. RESULTS: While receiving monotherapy (2 months, n = 366), the patients' systolic and diastolic decreases in daytime blood pressure averaged 22/14 mm Hg for nifedipine, 17/11 mm Hg for verapamil, 12/8 mm Hg for hydrochlorothiazide, and 5/3 mm Hg for enalapril. At 2 months the blood pressure of more patients treated with nifedipine was controlled: 133 (63.3%, P</=.03) vs 20 (39.9%) receiving verapamil, 21 (40.4%) receiving hydrochlorothiazide, and 11 (20.8%) receiving enalapril. At 13 months (n = 257), more patients (P<.001) continued receiving monotherapy with nifedipine (94/154 [61.0%]) or verapamil (22/35 [62.9%]) than hydrochlorothiazide (10/39 [25.6%]) or enalapril (1/29 [3.4%]). A sustained decrease of left ventricular mass (P<.001) with no between-group differences was achieved at 4 and 13 months. CONCLUSIONS: In contrast to current recommendations, calcium channel blockers are more effective than thiazides as initial treatment in black subjects with hypertension. If treatment is started with thiazides or converting-enzyme inhibitors, combination therapy is more likely to be required to control blood pressure and reduce left ventricular mass.

Adolescent↗
PubMed2001

Blood pressure, cognitive functions, and prevention of dementias in older patients with hypertension.

The prevalence and incidence of degenerative and vascular dementias increase exponentially with age, from 70 years onward. In view of the increasing longevity of humans, both varieties are bound to evolve into a major problem worldwide. According to several longitudinal studies, hypertension appears to predispose individuals to the development of cognitive impairment and ensuing dementia, after a period varying from a few years to several decades. Antihypertensive drug treatment, according to preliminary evidence, may serve to reduce the rates of such events. Such findings await to be confirmed by formal therapeutic trials against a backdrop of "historical" observational sources.

Aged↗
PubMed2001

The benefit of treating isolated systolic hypertension.

Isolated systolic hypertension affects over 15% of all people older than 60 years of age. In the elderly, systolic hypertension is a major modifiable cardiovascular risk factor. Systolic blood pressure is associated with higher risk of an adverse outcome. Diastolic blood pressure is inversely correlated with total mortality, independent of systolic blood pressure, highlighting the role of pulse pressure as risk factor. Three placebo-controlled outcome trials on antihypertensive drug treatment in older patients with isolated systolic hypertension have been published: the Systolic Hypertension in the Elderly Program (SHEP), the Systolic Hypertension in Europe (Syst-Eur) Trial, and the Systolic Hypertension in China (Syst-China) Trial. These three trials showed the benefit of antihypertensive drug treatment. A meta-analysis was done by pooling the patients from these three trials with a subset of patients with isolated systolic hypertension from five other trials in the elderly. The pooled results of 15,693 older patients with isolated systolic hypertension prove that antihypertensive drug treatment is justified if systolic blood pressure on repeated clinic measurements is 160 mm Hg or higher.

Aged↗
PubMed2001

Benefits of antihypertensive drug treatment in elderly patients with isolated systolic hypertension.

Isolated systolic hypertension affects over 15% of all people older than 60 years. In the elderly, systolic hypertension is a major modifiable cardiovascular risk factor. Systolic blood pressure is associated with higher risk of an adverse outcome, whereas diastolic blood pressure is inversely correlated with total mortality, independent of systolic blood pressure, highlighting the role of pulse pressure as risk factor. Three placebo-controlled outcome trials on antihypertensive drug treatment in older patients with isolated systolic hypertension have been published: the Systolic Hypertension in the Elderly Program (SHEP), the Systolic Hypertension in Europe (Syst-Eur) Trial and the Systolic Hypertension in China (Syst-China) Trial. These three trials demonstrated the benefit of antihypertensive drug treatment. A meta-analysis was performed by pooling the patients from these three trials with a subset of patients with isolated systolic hypertension from five other trials in the elderly. Antihypertensive treatment based on a calcium-channel blocker may provide additional benefits in diabetic patients and in the prevention of dementia and renal dysfunction. The pooled results of 15693 older patients with isolated systolic hypertension prove that antihypertensive drug treatment is justified if on repeated clinic measurements systolic blood pressure is 160 mmHg or higher.

Aged↗
PubMed2001

Menopause and the characteristics of the large arteries in a population study.

In previous cross-sectional and longitudinal population studies, we found that the slope of systolic pressure on age was steeper in postmenopausal than in premenopausal women. We hypothesised that this observation could be due to a specific effect of menopause on the elasticity of the large arteries. We investigated 315 randomly selected women, aged 30 to 70 years. Based on 5.2 years of follow-up, 166 women were premenopausal and 149 menopausal (44 reaching menopause and 105 postmenopausal). These women were matched on age and body mass index with 315 men. We used a wall-tracking ultrasound system to measure the diameter, compliance and distensibility of the brachial and the common carotid and femoral arteries as well as carotid-femoral pulse wave velocity. Pulse pressure was determined from 24-h blood pressure recordings. Both in menopausal women (r = 0.37; P < 0.001) and in matching male controls (r = 0.16; P = 0.04), pulse pressure widened with increasing age. The slope of the 24-h pulse pressure on age was steeper in menopausal women than in their premenopausal counterparts (0.428 vs -0.066 mm Hg per year; P = 0.003) and than in the male controls (0.428 vs 0.188 mm Hg per year; P = 0.06). After adjustment for age, 24-h mean pressure, body mass index, antihypertensive drug treatment, smoking and the use of oral contraceptives or hormonal replacement therapy, postmenopausal women showed a higher carotid-femoral pulse wave velocity (7.77 vs 6.71 m/s; P = 0.02) and had a slightly greater diameter of the common carotid artery (7.09 vs 6.79 mm; P = 0.07) than their premenopausal counterparts. After similar adjustments, menopausal class was not significantly associated with other vascular measurements in women or with any vascular measurement in control men. In conclusion, menopause per se may increase aortic stiffness. We hypothesise that this phenomenon may contribute to the rise in systolic pressure and pulse pressure in women beyond age 50 and, in turn, may lead to a slight dilatation of the common carotid artery.

Adult↗