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Biomedical subjects

Y W Wang

Publications and source records attributed to Y W Wang.

33 records · Page 2Linked to original sources
PubMed1995

Monitoring human risk and exposure to trinitrotoluene (TNT) using haemoglobin adducts as biomarkers.

Two studies were carried out in a trinitrotoluene (TNT) plant using TNT haemoglobin (TNT-Hb) adduct as a biomarker to study dose-adduct and adduct-response relationships. In the first study, TNT-Hb adduct levels were determined in 117 TNT-exposed workers in different working sites with different exposure conditions. External exposure was calculated from the inhaled air concentration plus skin contamination. TNT-Hb adduct levels in blood were significantly correlated with their external exposure to TNT. Two methods, HPLC-UV and CI-ELISA, were developed for measuring TNT-Hb adduct: good correlations (r = 0.77 and 0.86) were found between these 2 methods. In the second study, TNT cataract was used as an indicator of health effects. The prevalence of cataract and the degree of lenticular damage increased with the increase of blood TNT-Hb level.

Cataract↗
PubMed1994

Analysis of human platelet glycoprotein IIb-IIIa by fluorescein isothiocyanate-conjugated disintegrins with flow cytometry.

Disintegrins are a group of snake venom peptides which inhibit human platelet aggregation by acting as glycoprotein IIb-IIIa (GPIIb-IIIa) antagonists. They are cysteine-rich, Arg-Gly-Asp (RGD)-containing peptides, and bind to GPIIb-IIIa complex on platelet membrane with a very high affinity (Kd, 10(-7)-10(-8) M). In this study, we analyzed GPIIb-IIIa complex on platelet membrane by flow cytometry using fluorescein isothiocyanate (FITC)-conjugated disintegrins as probes. Of these FITC-conjugated disintegrins, FITC-Rhodostomin is the most sensitive probe because Rhodostomin was conjugated with more FITC molecules than Trigramin and Halysin were. The binding fluorescence intensity of FITC-Trigramin (FITC-Tg), FITC-Halysin (FITC-Hy) and FITC-Rhodostomin (FITC-Rn) was measured in both resting and ADP-activated platelets of diluted human platelet-rich plasma. The binding fluorescence of FITC-disintegrins was abolished by EDTA and 7E3, a monoclonal antibody against GPIIb-IIIa. ADP markedly increased the fluorescence intensity of FITC-Tg and FITC-Hy bound on platelets especially when lower doses of these probes were used, whereas it had little effect on that of FITC-Rn. Therefore, FITC-Tg and FITC-Hy can be used for the detection of the activated platelets as noted by a higher ratio of fluorescence intensity (approx. 2-4) between ADP-activated and resting platelets as compared with that (approx. 1-1.3) in the case of FITC-Rn as the probe. The platelets from three patients with Glanzmann's thrombasthenia were probed with FITC-disintegrins.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

[Experimental analysis of mechanism concerning the environmental temperature effect on acquisition of capability in toad oocyte to resume meiotic division].

Full-grown oocytes derived from Bufo bufo gargarizans rearing in high temperature environment (28-30 degrees C), called high temperature oocytes, never underwent germinal vesicle breakdown (GVBD) after progesterone stimulation, no MPF was detected in their ooplasm, but some events which manifested normally at the beginning of progesterone induced maturation process were revealed in these oocytes. It is worth notice an another kind of maturation promoting substance(s) appeared in the ooplasm of high temperature oocyte after the hormone treatment, which was capable of triggering the resumption of meiotic division of the full-grown oocytes derived from hibernating toad (called low temperature oocytes). It is a hibernation factor-dependent maturation promoting substance (HF-MPS), which appeared after decrease of the oocyte endogenous cAMP level. Its appearance depended upon the oocyte protein synthesis, and its activity to inducing GVBD of low temperature oocytes did not inhibited by puromycin. HF-MPS differs from MPF in maturation promoting activity, as low temperature (10 degrees C) delayed obviously HF-MPS' activity but did not influence the rate of GVBD induced by MPF. Further more, probably due to the lack of "hibernation factor(s)", no expression of p34cdc2 gene was detected in high temperature oocytes (unpublished data), neither HF-MPS nor MPF could amplify autocatalytically in the oocytes. So the low temperature (below 15 degrees C) was found to be indispensable for the toad oocyte maturation. If one day we can prove HF-MPS appeared also in the course of oocyte maturation induced by progesterone, the relationship between HF-MPS and MPF may be: [formula: see text] All these discoveries indicated above make a reasonable explanation of the geographical distribution of the toad which was restricted in the region north to the 23 degrees north latitude and east to the 100 degrees east longitude in China.

Animals↗
PubMed1993

[Percutaneous transfemoral plug closure of patent ductus arteriosus in 100 cases].

One hundred patients with patent ductus arterious (PDA) were treated successfully by percutaneous transfemoral plug closure since 1985. Age ranged from 5 to 48 years. Among them five had previous ligation of PDA, One was complicated with infective endocarditis, and in four pulmonary hypertension were found. The internal diameter shown in aortograph ranged from 0.26-1.0 cm. Primary success was accomplished after the first trial in 97 patients and second trial was necessary in three cases. However in one patient plug closure was given up after unsuccessful trial. The plug closure was carried out with domestic-made material and instrument in all cases. We adopted the modified Porstmann technique. We believe that the infrainguinal transfemoral approach is simple, and less traumatic. The indication of plug closure can be extended especially to residual or recanalization cases after ligation in selected cases. It may become the method of first choice for PDA. The "papillary type" of PDA is discussed and a specially designed and tailored plug and also a spontaneous flow-directed method were recommended. Frequent ventricular premature beats usually occurred while the catheters were being pushed through chordae tendinae of the tricuspid valve and the way of prevention was discussed. In case of dislodgement of plug, reestablishing the wire locus would be necessary. One to sixty-eight months follow up study after closure showed no sign of recanalization or residual shunt.

Adolescent↗
PubMed1992

Protective action of seven natural phenolic compounds against peroxidative damage to biomembranes.

The effects of seven phenolic compounds isolated from Salvia miltiorrhiza on peroxidative damage to liver microsomes, hepatocytes and erythrocytes of rats were studied. The results show that the seven compounds inhibited lipid peroxidation of rat liver microsomes induced by iron/cysteine and Vitamin C/NADPH. The hemolysis of rat erythrocytes induced by hydrogen peroxide was also inhibited. The degree of inhibition varied with different compounds. Among the seven compounds, the action of salvianolic acid A (Sai A) was the most potent. Therefore, the protective action of Sai A against peroxidative damage to isolated rat hepatocytes and their plasma membranes was evaluated further. Malondialdehyde (MDA) production and bleb of the surfaces of rat hepatocytes induced by iron/cysteine were prevented by Sai A. The production of MDA and the consumption of NADPH of the plasma membrane during lipid peroxidation initiated by iron/cysteine and Vitamin C/NADPH were also inhibited. The results strongly suggest that several phenolic compounds like Sai A have a protective action against peroxidative damage to biomembranes.

Animals↗
PubMed1989

[Endocarditis after extracorporeal circulation surgery].

Between January, 1976 and April 1988, 1279 patients underwent open-heart operation in Ren Ji Hospital. Thirty three patients were complicated by infective endocarditis postoperatively, an incidence of 2.58%. Medical treatment was carried out in 29 cases and thirteen were cured. In another three patients of valve prosthetic endocarditis, replacement of prosthetic valve was necessary for their cure. In our series, Gram negative bacilli had been proved by blood culture, autopsy and arterial thrombi in thirteen patients and candida in four, mixed infection in five and staphylococcus aureus in only one case. One should not rely on positive blood culture for the diagnosis. Echocardiographic studies are helpful to early diagnosis and proper treatment. The presence of vegetation or signs of prosthetic valve failure are strong indication for reoperation. In prevention, in addition to strict aseptic technic in the operating room, special emphasis should be focused on the preventive administration of sensitive antibiotics against hospital borne pathogens. All indwelling catheters in arteries and veins, tracheal tubes and urethral catheters should be removed after 72 hours. Efforts to prevent infection after reoperation are important measures for the prevention of infective endocarditis after open-heart operation.

Adolescent↗
PubMedDate not supplied

Ethnic and geographic variations in the prevalence of hepatitis A, B and C among aboriginal villages in Hualien, Taiwan.

BACKGROUND: Taiwan is endemic for viral hepatitis infections. A field survey was performed in the isolated aborigines in Hualien, eastern Taiwan, to investigate the geographic and ethnic variations in hepatitis epidemiology. MATERIALS AND METHODS: From 1996 to 1998, blood was drawn from 1,748 subjects from two southern Ami and two northern Atayal villages for serum markers of hepatitis A, B and C. RESULTS: Hepatitis A infection approached 100% in all groups. Hepatitis B infection and carrier rates were higher in the Atayal than in the Ami (92.3% vs. 49.1% and 20.8% vs. 5.3%; p<0.01). Hepatitis C infection rates were higher in three villages (27.5%, 20.1% and 25.4% vs. 3.6%; p<0.01). Hepatitis C infection increased with age (p<0.01) while hepatitis B infection did not. CONCLUSION: Hepatitis A infected most aborigines before the age of 15 years. Hepatitis B seldom infected people after the age of 15 years, while hepatitis C continued to infect people who were older. Geographic factors are important for hepatitis C infection, whereas for hepatitis B infection, in addition ethnicity is also important.

Adolescent↗