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Biomedical subjects

W Y Wu

Publications and source records attributed to W Y Wu.

At least 19 recordsLinked to original sources
PubMed2001

Effect of genotoxic exposure to chromium among electroplating workers in Taiwan.

The objective of this study was to investigate the association between chromium (Cr) concentrations and sister chromatid exchanges (SCE) formation in Cr workers and to assess the effects of susceptible genes (glutathione S-transferase M1 and T1) on the frequency of deletion and SCE/cell. Urinary Cr concentration was significantly elevated in Cr workers (3.67 +/- 3.89 microg/g creatinine) compared to control group (1.21 +/- 1.16 microg/g creatinine, P < 0.01). There was also a significant difference of superoxide dismutase (SOD) levels between Cr workers (6.86 +/- 0.80 U/mg Hb) and controls (7.16 +/- 0.53 U/mg Hb, P < 0.01). The frequencies of SCE and high frequency cells (HFC) were significantly correlated with smoking habits and with duration of exposure to Cr. A significantly higher percentage (50%) of Cr workers had both the null GSTM1 and GSTT1 genotype as compared to 10% of the controls (P < 0.01). However, the chromosomal DNA damage effect of GSTM1 and GSTT1 genotypes, individually or in combination, was not revealed in Cr exposed workers.

Adolescent↗
PubMed2001

Apoptosis induced by isoliquiritigenin in human gastric cancer MGC-803 cells.

Isoliquiritigenin, which is possibly a principal anti-tumor constituent of licorice, a traditional Chinese herb, was examined for apoptosis-inducing activity in human gastric cancer MGC-803 cells. Typical morphological and biochemical features of apoptosis including cell shrinkage, chromatin condensation, DNA ladder formation, and appearance of apoptotic peaks (subG(1)) were observed in MGC-803 cells with isoliquiritigenin treatment. Using Fluo-3 and Rh123 as fluorescent probes, respectively, it was found that the intracellular free calcium concentration increased and the mitochondrial transmembrane potential (Deltapsi(m)) decreased in a dose-dependent manner in apoptotic cells. These results suggest that isoliquiritigenin induced apoptosis of MGC-803 cells through calcium- and Deltapsi(m)-dependent pathways, indicating that it is potentially useful as a natural anti-cancer agent.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Two-photon laser scanning microscopy of epithelial cell-modulated collagen density in engineered human lung tissue.

Tissue remodeling is a complex process that can occur in response to a wound or injury. In lung tissue, abnormal remodeling can lead to permanent structural changes that are characteristic of important lung diseases such as interstitial pulmonary fibrosis and bronchial asthma. Fibroblast-mediated contraction of three-dimensional collagen gels is considered an in vitro model of tissue contraction and remodeling, and the epithelium is one factor thought to modulate this process. We studied the effects of epithelium on collagen density and contraction using two-photon laser scanning microscopy (TPLSM). TPLSM was used to image autofluorescence of collagen fibers in an engineered tissue model of the human respiratory mucosa -- a three-dimensional co-culture of human lung fibroblasts (CCD-18 lu), denatured type I collagen, and a monolayer of human alveolar epithelial cell line (A549) or human bronchial epithelial cell line (16HBE14o(-)). Tissues were imaged at days 1, 8, and 15 at 10 depths within the tissue. Gel contraction was measured concurrently with TPLSM imaging. Image analysis shows that gels without an epithelium had the fastest rate of decay of fluorescent signal, corresponding to highest collagen density. Results of the gel contraction assay show that gels without an epithelium also had the highest degree of contraction (19.8% +/- 4.0%). We conclude that epithelial cells modulate collagen density and contraction of engineered human lung tissue, and TPLSM is an effective tool to investigate this phenomenon.

Biomedical Engineering↗
PubMed2001

Large drug resistance virulence plasmids of clinical isolates of Salmonella enterica serovar Choleraesuis.

Salmonella enterica serovar Choleraesuis generally causes systemic human salmonellosis without diarrhea, and therefore, antimicrobial treatment is essential for such patients. The drug resistance information on this organism is thus of high value. Serovar Choleraesuis usually harbors a virulence plasmid (pSCV) of 50 kb in size. Of the 16 clinical isolates identified to be serovar Choleraesuis, all except one harbored a pSCV and seven of them carried a pSCV of more than 125 kb in size. A pSCV was defined as a plasmid carrying spvC and characteristic deletions detected by PCR and by DNA-DNA hybridization (for the former criterion). The results of PCR, restriction fragment profiles, and Southern DNA-DNA hybridizations of the profiles all indicated that such larger pSCVs were derived from the 50-kb plasmid recombined with non-pSCVs found in some clinical isolates. Fifteen of the 17 strains, including a laboratory strain, were then tested for drug resistance against 16 antibiotics with E-test and the dilution method. The laboratory strain, which harbored a 50-kb pSCV and a 6-kb non-pSCV, was resistant only to sulfonamides (SUL), and its resistance gene, sulII, checked with PCR and DNA-DNA hybridization, was located on the 6-kb non-pSCV. All 14 clinical strains were resistant to multiple drugs. Of the 14, 7 were resistant to SUL, and the resistance gene was located on a plasmid. The sulII gene, but not bla(TEM-1), was carried only on the 6-kb non-pSCV. Of the remaining six large plasmids, three of 90 kb, two of 136 kb, and one of 140 kb, the last three were pSCVs and carried the other SUL gene (sulI) and the bla(TEM-1) gene. The six strains were also resistant to trimethoprim-sulfamethoxazole. None of the 50-kb pSCVs carried resistance genes. These drug resistance genes on the large pSCVs were apparently also acquired through recombination.

Bacterial Proteins↗
PubMed2001

[A controlled clinical study between hepatic arterial infusion with embolized curcuma aromatic oil and chemical drugs in treating primary liver cancer].

OBJECTIVE: To evaluate the effectiveness, toxicity and prospective application of hepatic arterial infusion (HAI) with Embolized Curcuma Aromatic oil (CAO) in treating primary liver cancer (PLC). METHODS: In the treated group, 32 patients with PLC were treated by HAI with 1-3 ml of embolized CAO and oral administration of Chinese herbal medicine. In the control group, 32 patients with PLC were treated with transcatheter artery chemoembolization (TACE). RESULTS: In the treated group, one patient attained complete remission (CR) and 13 partial remission (PR), the total effective rate being 43.75%. The level of alpha fetal protein (AFP) turned to normal range in 7 cases and decreased in other 7. In the control group, 10 obtained PR and the total effective rate being 31.25%, AFP level turned to normal in 5 and decreased in 2. There was no statistical significance between the two groups. The incidences of post-embolism syndrome, such as fever, abdominal pain and vomiting were similar between the two groups but no myelosuppression occurred in the treated group with significant difference (P < 0.01) as comparing with that in the control group. The mean survival time, median survival time, 1-, 2- and 3-year survival rate in the treated group was 11.5 months, 10 months, 37.5%, 13.3% and 6.9% respectively, while in the control group was 7.25 months, 6 months, 15.6%, 3.2% and 0 respectively. The treated group was better in mean survival time, median survival time and 1-year survival rate than that of the control group (P < 0.05). CONCLUSION: HAI with embolized CAO showed a similar favorite effect in treating PLC as that of TACE, but superior than TACE with longer survival time and milder myelosuppression.

Adult↗
PubMed2000

Cytogenetic study of workers exposed to chromium compounds.

The frequency of sister chromatid exchanges (SCEs), high SCE frequency cells (HFCs), and genetic polymorphism of genotypes glutathione S-transferase (GST) M1 and T1 were analyzed in peripheral lymphocytes of 35 workers occupationally exposed to chromium (Cr) and 35 matched control group. Results showed that workers exposed to Cr showed 6.07 SCE/cell, as compared to 4.76 SCE/cell for the control group (p<0.01). Smokers showed a statistically significant higher frequency of SCE than non-smokers in both groups. The work duration of Cr workers was an important factor. Workers exposed for more than 5 years showed a significantly higher level of SCEs (p<0.05). Workers exposed to Cr for 5 or more years had higher HFC rates (51.4%) than those exposed for less than 5 years (22.9%), with an odds ratio of 4.5 times than those exposed for less than 5 years. In HFC analysis, Cr workers who smoked showed a higher level of HFC (60%) than the control group (5.7%) and also had a higher odds ratio (60.4) compared with the control group. Among non-smokers, the odds ratio was 9.0. Another objective of this study is to investigate the relationship between SCE and genetic polymorphisms of GST M1 and T1 in Cr workers. The results showed that the incidence of GSTM1 null genotype was 60% in the control group and 77.1% in Cr workers, and percentages of GSTT1 deletion were 42.9% and 62.9% in control and exposed individuals, respectively. There was a slightly increased frequency of SCE among Cr workers with GSTM1 null genotype as opposed to non-null genotype individuals. A similar result was seen among the control group; however, there were no statistically significant differences. In conclusion, the current study found the positive induction of SCE in workers who smoked or/and were exposed to Cr. However, different GST genotypes did not influence the level of cytogenetic damage between groups. Despite slight variation in numbers, they all appear to be not different.

Adult↗
PubMed1997

A cross-cultural validation of coping strategies and their associations with caregiving distress.

Coping strategies were compared among family caregivers of Alzheimer's disease patients in Shanghai, China (n = 110) and San Diego, California (n = 139). Four coping factors were reliably consistent in both samples, supporting their widespread relevance to life adversity; behavioral confronting, behavioral distancing/social support, cognitive confronting, and cognitive distancing. Shanghai and San Diego caregivers endorsed similar rates of coping, but Shanghai caregivers reported fewer symptoms of depression and anxiety. Although coping strategies were similar, cultural ideals promoting family interdependence, veneration of elderly family members, and acceptance of traditional family roles may have reduced the psychological impacts of caregiving in the Shanghai sample.

Adaptation, Psychological↗
PubMed1996

A study of the active site of influenza virus sialidase: an approach to the rational design of novel anti-influenza drugs.

The development of sialidase inhibitor-based potential anti-influenza drugs using rational drug design techniques has been of recent interest. The present study details as investigation of the active site of influenza virus sialidase by using the program GRID in an attempt to design more potent inhibitors in the hope they will eventually lead to anti-influenza drugs. A number of different probes (amino, carboxy, hydroxy, methyl, etc) have been used in an effort to determine the functional groups most likely to improve the binding of the starting template 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (Neu5Ac2en). The data have correctly predicted the binding regions for the carboxylate, acetamido (NH and methyl), and glycerol (OH) groups of N-acetylneuraminic acid. Moreover, the data suggest that the addition of certain functionalities (amino group) at the C-4 position should enhance the overall binding.

Antiviral Agents↗
PubMed1994

Analysis of the double-stranded RNA genome segments among avian reovirus field isolates.

Nine isolates of avian reovirus (ARV) from both healthy birds and birds with different clinical illness and one commercially available vaccine strain were selected and characterized by analysis of the migration pattern of their genomic double-stranded RNA (dsRNA) segments following separation by polyacrylamide gel electrophoresis. Different electropherotypes were observed and analyzed. The results show that the dsRNA segments of ARV were markedly polymorphic among isolates within the same serotype as well as among different serotypes. The results also show no correlation between electropherotype and disease state.

Animals↗
PubMed1994

National field trial of the Chinese classification and diagnostic criteria of mental disorders: comprehensibility, acceptability and applicability.

The Chinese Neurology and Psychiatry Association conducted a national field trial of its Chinese Classification and Diagnostic Criteria of Mental Disorders (CCMD-2) involving 26 provinces and municipalities, 80 psychiatric institutes, and 224 professionals. The results were as follows: (1) 95.2% of researchers considered the comprehensibility of the CCMD-2 diagnostic criteria good. Within the ten major categories, comprehensibility ranged from 85.7% to 100%. (2) Of those surveyed concerning the acceptability of the CCMD-2 diagnostic criteria, 85.9% considered them acceptable. In individual classifications, the rate ranged from 74.1% to 95.2%. (3) 1498 cases were tested. The overall applicability rate which indicated the consistency between the CCMD-2 result and the actual clinical diagnoses was found to be 87.6%, (averaging Kappa = 0.82, P < 0.01), better than those obtained from non-Chinese systems of diagnosis.

Adult↗
PubMed1993

Rational design of potent sialidase-based inhibitors of influenza virus replication.

Two potent inhibitors based on the crystal structure of influenza virus sialidase have been designed. These compounds are effective inhibitors not only of the enzyme, but also of the virus in cell culture and in animal models. The results provide an example of the power of rational, computer-assisted drug design, as well as indicating significant progress in the development of a new therapeutic or prophylactic treatment for influenza infection.

Animals↗
PubMed1993

Inhibition of sialidases from viral, bacterial and mammalian sources by analogues of 2-deoxy-2,3-didehydro-N-acetylneuraminic acid modified at the C-4 position.

The inhibition of sialidase activity from influenza viruses A and B, parainfluenza 2 virus, Vibrio cholerae, Arthrobacter ureafaciens, Clostridium perfringens, and sheep liver by a range of 2-deoxy-2,3-didehydro-N-acetylneuraminic acid analogues modified at the C-4 position has been studied. All substitutions tested resulted in a decrease in the degree of inhibition of the bacterial and mammalian sialidases. For sialidases from influenza viruses A and B, on the other hand, most of the substitutions tested either had no significant effect on binding or, in the case of the basic amino and guanidino substituents, resulted in significantly stronger inhibition. The results for parainfluenza 2 virus sialidase were mostly intermediate, in that inhibition was neither significantly increased nor decreased by most of the modifications. We conclude that only the influenza A and B sialidase active sites possess acid groups correctly positioned to participate in charge-charge interactions in the region of C-4 of bound substrate, and that the C-4 binding pockets of the bacterial and mammalian sialidases examined are considerably smaller than is observed for either the influenza virus or parainfluenza virus sialidases.

Animals↗
PubMed1993

[A nationwide field trial of the Chinese classification and diagnostic criteria of mental disorders: application and evaluation].

To test the quality and feasibility of the Chinese Classification and Diagnostic Criteria of Mental Disorders (CCMD-2), a nationwide field trial was carried out by 224 professionals from 80 psychiatric facilities. The results showed that the diagnostic criteria of CCMD-2 was clearly understandable and acceptable reported by 95.2% and 85.2% of the researchers. From a survey sample of 1,489 cases of mental disorders, the interrater agreement of criteria diagnosis was 0.96 (K) and the concordance between the diagnosis from clinical records and that based upon the criteria was 0.84(K) indicating the excellent reliability and validity of CCMD-2.

Adolescent↗
PubMed1992

The development of an enzyme-linked immunosorbent assay (ELISA) for cephalexin.

Cephalexin was structurally modified by the attachment of a spacer at the carboxylic acid through which it was subsequently covalently attached to BSA. This method permitted the molecule to be attached without cleavage of the beta-lactam ring giving a conjugate distinct from previously described immunogenic preparations of penicillins and cephalosporins. This approach required the development of a novel spacer molecule, and its synthesis and characterisation are reported. Rabbits were used to raise antisera and the antibodies produced were characterised with respect to their reactivity with cephalexin and various analogues, other cephalosporins, and a number of penicillins.

Animals↗
PubMed1990

The double porosity model for mass transfer between capillaries and tissues in lung microcirculation.

This paper proposes a double porosity model to deal with the mass transfer between capillaries and tissues in the lung microcirculation on the basis of. Utilizing the analytic method of small parameter expansion and the numerical method, the nonlinear governing equations are solved. Comparison shows that the small parameter solution is accurate enough to illustrate the mass exchange between the lung capillary and tissues. Finally the results are used to discuss the mechanism of formation of lung edema.

Capillaries↗
PubMed1989

[Ectopic HCG in transitional cell carcinoma of the bladder by immuno-histochemical survey].

Production of human chorionic gonadotropin (HCG) by transitional cell carcinoma of bladder is considered as a rare phenomenon. Among 60 cases of transitional cell carcinoma of the bladder, six cases were positive for beta-HCG, which were detected with anti-beta-HCG by PAP technique. They were classified as grade III and IV, being provided with 20.68% of all of the grade III and IV cases reported, of these six patients, four died within one year. It is suggested that carcinomas of the bladder bearing the capability of producing HCG tend to have a higher malignancy and poor histological differentiation. The possible origin and histogenesis of HCG are discussed.

Carcinoma, Transitional Cell↗