33 results on '"Wong WS"'
Search Results
2. Initiating pedogenesis of magnetite tailings using Lupinus angustifolius (narrow-leaf lupin) as an ecological engineer to promote native plant establishment.
- Author
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Zhong H, Lambers H, Wong WS, Dixon KW, Stevens JC, and Cross AT
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- Australia, Ecosystem, Ferrosoferric Oxide, Plant Leaves chemistry, Soil, Lupinus, Soil Pollutants analysis
- Abstract
Mine tailings pose physical and chemical challenges for plant establishment. Our aim was to learn from natural processes in long-term soil and ecosystem development to use tailings as novel parent materials and pioneer ecological-engineering plant species to ameliorate extreme conditions of tailings, and facilitate the establishment of subsequent native plants. A glasshouse trial was conducted using magnetite tailings containing various amendments, investigating the potential of the nitrogen (N)-fixing, non-native pioneer species Lupinus angustifolius (Fabaceae), narrow-leaf lupin, as a potential eco-engineer to promote soil formation processes, and whether amendment type or the presence of pioneer vegetation improved the subsequent establishment and growth of 40 species of native plants. We found that L. angustifolius eco-engineered the mine tailings, by enhancing the N status of tailings and mobilising primary mineral P into organic P via a carboxylate-exudation strategy, thereby enabling subsequent growth of native species. The substantial increases of the soil organic P (from ca. 10 to 150 mg kg
-1 ) pool and organo-bound Al minerals (from 0 to 2 mg kg-1 ) were particularly evident, indicating the initiation of pedogenesis in mine tailings. Our findings suggest that the annual legume L. angustifolius has eco-engineering potential on mine tailings through N-fixation and P-mobilisation, promoting the subsequent growth of native plants. We proposed Daviesia (Fabaceae) species as native species alternatives for the non-native L. angustifolius in the Western Australian context. Our findings are important for restoration practitioners tasked with mine site restoration in terms of screening pioneer eco-engineering plant species, where native plants are required to restore after mine operations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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3. Exceptional nitrogen-resorption efficiency enables Maireana species (Chenopodiaceae) to function as pioneers at a mine-restoration site.
- Author
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Zhong H, Zhou J, Wong WS, Cross A, and Lambers H
- Subjects
- Mining, Nitrogen, Soil, Chenopodiaceae, Soil Pollutants analysis
- Abstract
Tailings are among the most challenging mined substrates for plant re-establishment, in particular because of a lack of soil-like structure and nitrogen. Potential pioneer plants are sometimes found in such disturbed and infertile sites. We present a group of pioneer species from the genus Maireana (Chenopodiaceae) that are promising candidates for the restoration of magnetite tailings. We found that these Maireana species did not rely on biologically fixed N from the atmosphere, but exhibited an exceptionally high leaf N-resorption efficiency (about 95%) during leaf senescence, at the same time effectively scavenging trace amount of N from the substrate, in part through rapid transpiration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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4. Plasmodium vivax infection with exflagellated microgametes in peripheral blood smears.
- Author
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Li THS, Lee ACH, Wong WS, and Yip YL
- Published
- 2021
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5. Advanced technologies charting a new path for traditional Chinese medicine drug discovery.
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Leung EL, Clementi E, and Wong WS
- Subjects
- Computational Biology methods, Drugs, Chinese Herbal pharmacology, Humans, Microscopy, Atomic Force methods, Nanotechnology methods, Drug Discovery methods, Drugs, Chinese Herbal therapeutic use, Medicine, Chinese Traditional methods
- Published
- 2017
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6. Utility of whole-genome sequencing for detection of newborn screening disorders in a population cohort of 1,696 neonates.
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Bodian DL, Klein E, Iyer RK, Wong WS, Kothiyal P, Stauffer D, Huddleston KC, Gaither AD, Remsburg I, Khromykh A, Baker RL, Maxwell GL, Vockley JG, Niederhuber JE, and Solomon BD
- Subjects
- Cohort Studies, Female, Genetic Variation, Humans, Infant, Newborn, Male, Sensitivity and Specificity, Genetic Predisposition to Disease, Genome, Human, Neonatal Screening methods, Sequence Analysis, DNA methods
- Abstract
Purpose: To assess the potential of whole-genome sequencing (WGS) to replicate and augment results from conventional blood-based newborn screening (NBS)., Methods: Research-generated WGS data from an ancestrally diverse cohort of 1,696 infants and both parents of each infant were analyzed for variants in 163 genes involved in disorders included or under discussion for inclusion in US NBS programs. WGS results were compared with results from state NBS and related follow-up testing., Results: NBS genes are generally well covered by WGS. There is a median of one (range: 0-6) database-annotated pathogenic variant in the NBS genes per infant. Results of WGS and NBS in detecting 28 state-screened disorders and four hemoglobin traits were concordant for 88.6% of true positives (n = 35) and 98.9% of true negatives (n = 45,757). Of the five infants affected with a state-screened disorder, WGS identified two whereas NBS detected four. WGS yielded fewer false positives than NBS (0.037 vs. 0.17%) but more results of uncertain significance (0.90 vs. 0.013%)., Conclusion: WGS may help rule in and rule out NBS disorders, pinpoint molecular diagnoses, and detect conditions not amenable to current NBS assays.
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- 2016
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7. Cystic Endosalpingiosis or Multicystic Mesothelioma?
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Wong WS and Lee ET
- Subjects
- Female, Humans, Adenomyosis complications, Fallopian Tube Diseases complications, Leiomyoma complications, Uterine Neoplasms complications
- Published
- 2016
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8. Oxidative and Nitrosative Stress and Histone Deacetylase-2 Activity in Exacerbations of COPD.
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Footitt J, Mallia P, Durham AL, Ho WE, Trujillo-Torralbo MB, Telcian AG, Del Rosario A, Chang C, Peh HY, Kebadze T, Aniscenko J, Stanciu L, Essilfie-Quaye S, Ito K, Barnes PJ, Elkin SL, Kon OM, Wong WS, Adcock IM, and Johnston SL
- Subjects
- Case-Control Studies, Disease Progression, Female, Humans, Inflammation Mediators metabolism, Male, Middle Aged, Nitrosation physiology, Picornaviridae Infections complications, Sputum, Viral Load, Histone Deacetylase 2 metabolism, Oxidative Stress physiology, Picornaviridae Infections metabolism, Pulmonary Disease, Chronic Obstructive complications, Pulmonary Disease, Chronic Obstructive metabolism, Rhinovirus
- Abstract
Background: Respiratory virus infections are commonly associated with COPD exacerbations, but little is known about the mechanisms linking virus infection to exacerbations. Pathogenic mechanisms in stable COPD include oxidative and nitrosative stress and reduced activity of histone deacetylase-2 (HDAC2), but their roles in COPD exacerbations is unknown. We investigated oxidative and nitrosative stress (O&NS) and HDAC2 in COPD exacerbations using experimental rhinovirus infection., Methods: Nine subjects with COPD (Global Initiative for Chronic Obstructive Lung Disease stage II), 10 smokers, and 11 nonsmokers were successfully infected with rhinovirus. Markers of O&NS-associated cellular damage, and inflammatory mediators and proteases were measured in sputum, and HDAC2 activity was measured in sputum and bronchoalveolar macrophages. In an in vitro model, monocyte-derived THP-1 cells were infected with rhinovirus and nitrosylation and activity of HDAC2 was measured., Results: Rhinovirus infection induced significant increases in airways inflammation and markers of O&NS in subjects with COPD. O&NS markers correlated with virus load and inflammatory markers. Macrophage HDAC2 activity was reduced during exacerbation and correlated inversely with virus load, inflammatory markers, and nitrosative stress. Sputum macrophage HDAC2 activity pre-infection was inversely associated with sputum virus load and inflammatory markers during exacerbation. Rhinovirus infection of monocytes induced nitrosylation of HDAC2 and reduced HDAC2 activity; inhibition of O&NS inhibited rhinovirus-induced inflammatory cytokines., Conclusions: O&NS, airways inflammation, and impaired HDAC2 may be important mechanisms of virus-induced COPD exacerbations. Therapies targeting these mechanisms offer potential new treatments for COPD exacerbations., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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9. Factor structure and psychometric properties of the Chinese version of the 20-item Pain Anxiety Symptoms Scale (ChPASS-20).
- Author
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Wong WS, McCracken LM, and Fielding R
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- Adolescent, Adult, Aged, Aged, 80 and over, China epidemiology, Comorbidity, Female, Humans, Male, Middle Aged, Pain Measurement statistics & numerical data, Prevalence, Psychometrics statistics & numerical data, Reproducibility of Results, Sensitivity and Specificity, Surveys and Questionnaires, Young Adult, Anxiety diagnosis, Anxiety epidemiology, Pain diagnosis, Pain epidemiology, Pain Measurement methods, Psychometrics methods, Severity of Illness Index
- Abstract
Context: The Pain Anxiety Symptoms Scale (PASS) was designed to assess pain-related anxiety and fear. Although the scale is a reliable measure with good psychometric properties, its validity among ethnic Chinese has yet to be evaluated., Objectives: This study aimed to translate the English-language version of the 20-item PASS into Chinese (ChPASS-20) and evaluate its factor structure, reliability, and validity., Methods: A total of 223 Chinese patients with chronic musculoskeletal pain attending orthopedic specialist clinics completed the ChPASS-20, the Chronic Pain Grade questionnaire, the Chinese version of the 11-item Tampa Scale of Kinesiophobia, the Hospital Anxiety and Depression Scale, and questions assessing sociodemographic and pain characteristics., Results: Confirmatory factor analyses showed that all the five-factor solutions tested met the minimum acceptable fit criterion. The four ChPASS-20 subscales and the entire scale demonstrated good internal consistency (Cronbach's αs: 0.72-0.92). All ChPASS-20 scales showed significant positive correlations with depression, pain intensity, and disability. Hierarchical multiple regression analyses showed that the ChPASS-20 total score predicted concurrent depression [F(4,159)=11.97, P<0.001], pain intensity [F(4,161)=2.47, P<0.05], and pain disability [F(4,191)=5.47, P<0.001] scores, and the ChPASS-20 Avoidance subscale (standardized beta coefficient=0.21, P<0.05) emerged as a significant independent predictor of concurrent pain disability., Conclusion: Our data support the factorial validity, reliability, and construct validity of the ChPASS-20 in a Chinese population., (Copyright © 2012 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.)
- Published
- 2012
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10. Pain-related beliefs among Chinese patients with chronic pain: the construct and concurrent predictive validity of the Chinese version of the Survey of Pain Attitudes-14 (ChSOPA-14).
- Author
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Wong WS, Jensen MP, Mak KH, and Fielding R
- Subjects
- Adaptation, Psychological, Adult, Asian People psychology, Female, Health Surveys, Humans, Male, Middle Aged, Pain Measurement, Predictive Value of Tests, Psychometrics, Reproducibility of Results, Attitude to Health, Chronic Pain psychology, Culture
- Abstract
Context: Pain beliefs as indexed by the Survey of Pain Attitudes (SOPA) have been consistently shown to predict pain adjustment outcomes in Western populations. However, its utility in non-Western populations is unclear., Objectives: We evaluated the construct and predictive validity of the Chinese version of the 14-item SOPA (ChSOPA-14) in a sample of Chinese patients with chronic pain., Methods: A total of 208 Chinese patients with chronic musculoskeletal pain completed the ChSOPA-14, the Chronic Pain Grade questionnaire, the Pain Catastrophizing Scale, the Center for Epidemiological Studies-Depression Scale, and measures of sociodemographic characteristics., Results: Except Medical Cure, all ChSOPA-14 scales were significantly correlated with validity criterion measures (all P<0.05) in expected directions. The present Chinese sample scored the highest on the Medical Cure scale (mean=2.98, standard deviation [SD]=1.05) but the lowest on the Disability scale (mean=1.75, SD=1.67). Results of hierarchical multiple regression analyses showed that the ChSOPA-14 scales predicted concurrent depression (F(7,177)=14.51, P<0.001) and pain disability (F(7,180)=8.77, P<0.001). Pain Control (stdβ [standardized beta coefficient]=-0.13; 95% confidence interval [CI]: -3.41, -0.13; P<0.05) and Emotion (stdβ=29; 95% CI: 1.76, 5.02; P<0.001) emerged as significant independent predictors of concurrent depression whereas Disability (stdβ=0.19; 95% CI: 1.33, 7.88; P<0.01), Emotion (stdβ=16; 95% CI: 0.08, 7.59; P<0.05), and Solicitude (stdβ=-0.14; 95% CI: -7.05, -0.04; P<0.05) significantly associated with concurrent disability., Conclusion: The findings offer preliminary evidence for the construct and concurrent predictive validity of the ChSOPA-14. This makes available a suitable instrument for chronic pain in the Chinese population and will facilitate future cross-cultural research on pain beliefs., (Copyright © 2011 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.)
- Published
- 2011
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11. Assessing attitudes toward and beliefs about pain among Chinese patients with chronic pain: validity and reliability of the Chinese version of the Pain Beliefs and Perceptions Inventory (ChPBPI).
- Author
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Wong WS, Williams DA, Mak KH, and Fielding R
- Subjects
- Adult, Aged, Asian People, Female, Hong Kong, Humans, Male, Middle Aged, Pain Measurement, Psychometrics, Reproducibility of Results, Surveys and Questionnaires, Chronic Pain psychology, Health Knowledge, Attitudes, Practice
- Abstract
Context: Research consistently has evidenced the reliability and validity of the Pain Beliefs and Perceptions Inventory (PBPI). The instrument, however, has not been tested for its applicability and validity in non-Western populations., Objectives: To translate the English language version of the PBPI into Chinese (ChPBPI) and to evaluate its reliability, validity, and factor structure., Methods: A total of 208 Chinese patients with mixed origin chronic pain were recruited from an orthopedic specialist outpatient clinic associated with a public hospital in Hong Kong. In addition to the ChPBPI, patients were administered the Chronic Pain Grade (CPG) questionnaire, the Pain Catastrophizing Scale (PCS), the Center for Epidemiological Studies-Depression Scale (CES-D), and questions assessing sociodemographic characteristics., Results: Using the original factor structure of the PBPI as a model, confirmatory factor analyses revealed that all four ChPBPI scales demonstrated good data-model fit (CFI≥0.92) and adequate internal consistency (Cronbach's αs: 0.60-0.76). The four ChPBPI scales showed significant positive correlations with CES-D, PCS, pain intensity, and disability. Results of hierarchical multiple regression analyses showed that the ChPBPI scales predicted concurrent depression (F(4, 187)=6.01, P<0.001), pain intensity (F(4, 186)=4.61, P<0.01), and pain disability (F(4, 190)=3.54, P<0.05) scores., Conclusion: These findings support the factorial validity of the scales of the ChPBPI, and its reliability and construct validity. Now clinically relevant beliefs about pain can be assessed among Chinese patients with chronic pain., (Copyright © 2011 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.)
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- 2011
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12. Patients with Epstein-Fechtner syndromes owing to MYH9 R702 mutations develop progressive proteinuric renal disease.
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Sekine T, Konno M, Sasaki S, Moritani S, Miura T, Wong WS, Nishio H, Nishiguchi T, Ohuchi MY, Tsuchiya S, Matsuyama T, Kanegane H, Ida K, Miura K, Harita Y, Hattori M, Horita S, Igarashi T, Saito H, and Kunishima S
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Disease Progression, Female, Hearing Loss, Sensorineural genetics, Humans, Male, Nephritis, Hereditary genetics, Thrombocytopenia genetics, Young Adult, Kidney Diseases etiology, Molecular Motor Proteins genetics, Mutation, Myosin Heavy Chains genetics, Proteinuria etiology
- Abstract
Recent linkage analyses of nondiabetic African-American patients with focal segmental glomerulosclerosis (FSGS) have identified MYH9, encoding nonmuscle myosin heavy chain IIA (NMMHC-IIA), as a gene having a critical role in this disease. Abnormalities of the MYH9 locus also underlie rare autosomal dominant diseases such as May-Hegglin anomaly, and Sebastian, Epstein (EPS), and Fechtner (FTNS) syndromes that are characterized by macrothrombocytopenia and cytoplasmic inclusion bodies in granulocytes. Among these diseases, patients with EPS or FTNS develop progressive nephritis and hearing disability. We analyzed clinical features and pathophysiological findings of nine EPS-FTNS patients with MYH9 mutations at the R702 codon hot spot. Most developed proteinuria and/or hematuria in early infancy and had a rapid progression of renal impairment during adolescence. Renal histopathological findings in one patient showed changes compatible with FSGS. The intensity of immunostaining for NMMHC-IIA in podocytes was decreased in this patient compared with control patients. Thus, MYH9 R702 mutations display a strict genotype-phenotype correlation, and lead to the rapid deterioration of podocyte structure. Our results highlight the critical role of NMMHC-IIA in the development of FSGS.
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- 2010
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13. Novel Vaginal "paper roll" uterine morcellation technique for removal of large (>500 g) uterus.
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Wong WS, Lee TC, and Lim CE
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- Adult, Blood Loss, Surgical, Female, Humans, Middle Aged, Organ Size, Retrospective Studies, Treatment Outcome, Uterus pathology, Hysterectomy, Vaginal methods, Uterine Diseases surgery, Uterus surgery, Vagina surgery
- Abstract
At laparoscopic-assisted vaginal hysterectomy with a novel "paper roll" vaginal morcellation technique, large uteri (> or = 500 g) can be removed via the vagina with safety, speed, and ease. The technique provides protection for the bladder and rectum, and large uteri can be removed in 1 piece, allowing the pathologist to reconstruct the entire uterus., (Copyright 2010 AAGL. All rights reserved.)
- Published
- 2010
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14. A critical decrease in dominant frequency and clinical outcome after catheter ablation of persistent atrial fibrillation.
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Yoshida K, Chugh A, Good E, Crawford T, Myles J, Veerareddy S, Billakanty S, Wong WS, Ebinger M, Pelosi F, Jongnarangsin K, Bogun F, Morady F, and Oral H
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- Aged, Atrial Fibrillation therapy, Electrocardiography, Female, Fourier Analysis, Humans, Male, Middle Aged, Predictive Value of Tests, Pulmonary Veins surgery, Retrospective Studies, Time Factors, Treatment Outcome, Atrial Fibrillation physiopathology, Catheter Ablation
- Abstract
Background: Termination of persistent atrial fibrillation (AF) by radiofrequency ablation (RFA) is associated with a high probability of freedom from AF but requires extensive ablation and long procedure times., Objective: The purpose of this study was to determine whether a critical decrease in the dominant frequency (DF) of AF is a sufficient endpoint for RFA of persistent AF., Methods: Antral pulmonary vein isolation (APVI) followed by RFA of complex fractionated atrial electrograms (CFAEs) in the atria and coronary sinus was performed in 100 consecutive patients with persistent AF. The DF of AF in lead V1 and in the coronary sinus was determined by fast Fourier transform (FFT) analysis at baseline and before termination of AF to identify a critical decrease in DF predictive of sinus rhythm after RFA., Results: A > or =11% decrease in DF had the highest accuracy in predicting freedom from atrial arrhythmias, with a sensitivity of 0.71 and a specificity of 0.82 (P <.001). At a mean follow-up of 14 +/- 3 months after one ablation procedure, sinus rhythm was maintained off antiarrhythmic drugs in 8/35 (23%) and 20/26 (77%) of patients with a <11% and > or =11% decrease in DF, respectively (P <.001). Sinus rhythm was maintained in 24/39 patients (62%) in whom RFA terminated AF. The duration of RFA and total procedure time were longer in patients with AF termination (95 +/- 23 and 358 +/- 87 minutes) than in patients with a <11% decrease in the DF (77 +/- 16 and 293 +/- 70 minutes) or > or =11% decrease in DF (80 +/- 17 and 289 +/- 73 minutes), respectively (P <.01). Among the variables of age, gender, left atrial diameter, duration of AF, left ventricular ejection fraction, duration of RFA, a > or =11% decrease in DF, and termination of AF, a > or =11% decrease in DF (odds ratio = 9.89, 95% confidence interval [CI] 2.84-34.47) and termination during RFA (OR = 4.38, 95% CI 1.50-12.80) were the only independent predictors of freedom from recurrent atrial arrhythmias., Conclusion: In a retrospective analysis of consecutive patients with persistent AF, a decrease in the DF of AF by 11% in response to APVI and ablation of CFAEs was associated with a probability of maintaining sinus rhythm that was similar to that when RFA terminates AF., (Copyright 2009 Heart Rhythm Society. All rights reserved.)
- Published
- 2010
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15. Hysteroscopic appearance of endometrial cavity after microwave endometrial ablation.
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Luo X, Lim CE, Li L, and Wong WS
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- Adult, Endometrium pathology, Endometrium surgery, Female, Follow-Up Studies, Humans, Menorrhagia pathology, Middle Aged, Patient Satisfaction, Prospective Studies, Treatment Outcome, Endometrial Ablation Techniques methods, Endometrium radiation effects, Hysteroscopy methods, Menorrhagia radiotherapy, Microwaves therapeutic use
- Abstract
Study Objective: To assess the appearance of the endometrial cavity after microwave endometrial ablation., Design: Prospective observational study., Setting: GuangDong Women's and Children's Hospital, GuangDong, China., Patients: A total of 349 patients who underwent microwave endometrial ablation from January 2000 through August 2008 were followed up for 1 month to 8 years. At follow-up in 2007 and 2008, patients were advised of this clinical study and were randomly selected for participation if they agreed to undergo outpatient hysteroscopy to assess the uterine cavity during follow-up visits. Fifty three patients (median [range] age, 43.1 [33-53] years) were recruited into the study at the time of endometrial ablation., Intervention: Outpatient hysteroscopy., Main Results: Within the first 3 months after ablation, outpatient hysteroscopy revealed varying amounts of necrotic tissue from the endometrium and superficial myometrium of the uterus. Six months postablation, a granulomatous reaction and fibrosis were present. A fibrotic cavity was also evident, and menstrual flow was reduced or had ceased. One year after ablation, hysteroscopy demonstrated a fibrotic cavity with myofibrous scars. Most patients developed amenorrhea at this time. Two years or more postablation, a second hysteroscopy demonstrated various types of intrauterine adhesions in 28 of the 53 women (52.8%). A cervical adhesion was observed in 1 patient (1.9%), focal adhesions in the fundal area in 12 (22.6%), a narrowed and scarred uterine cavity with bilateral stenotic tubal ostia in 11 (20.7%), and complete obliteration of the cavity in 4 (7.5%). Of these 28 women, 22 had amenorrhea, 3 had vaginal spotting during menstruation, and 2 had hypomenorrhea. Of those without intrauterine adhesions, only 5 had amenorrhea, 10 had vaginal spotting, and 8 had hypomenorrhea., Conclusion: The hysteroscopic appearance of the uterine cavity after microwave endometrial ablation varies considerably. In this study, the menstrual outcome was correlated with postablation uterine cavity appearance., (Copyright (c) 2010 AAGL. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
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16. Inadvertent electrical isolation of the left atrial appendage during catheter ablation of persistent atrial fibrillation.
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Chan CP, Wong WS, Pumprueg S, Veerareddy S, Billakanty S, Ellis C, Chae S, Buerkel D, Aasbo J, Crawford T, Good E, Jongnarangsin K, Ebinger M, Bogun F, Pelosi F, Oral H, Morady F, and Chugh A
- Subjects
- Atrial Fibrillation physiopathology, Electrophysiologic Techniques, Cardiac, Female, Humans, Male, Middle Aged, Treatment Outcome, Atrial Appendage injuries, Atrial Fibrillation surgery, Catheter Ablation methods
- Abstract
Background: Left atrial appendage (LAA) isolation is rare and may be associated with impaired transport function and thromboembolism., Objective: The purpose of this study was to determine the mechanisms of inadvertent isolation of the LAA during atrial fibrillation (AF) ablation., Methods: This study consisted of 11 patients (ejection fraction 0.43 +/- 0.18, left atrial diameter 51 +/- 8 mm) with persistent AF who had LAA conduction block during a procedure for AF (n = 8) or atrial tachycardia (AT) (n = 3)., Results: LAA conduction block occurred during ablation at the Bachmann bundle region in 6 patients, mitral isthmus in 3, LAA base in 2, and coronary sinus in 1. The mean distance from the ablation site to the LAA base was 5.0 +/- 1.9 cm. LAA isolation was transient in all 6 patients in whom LAA conduction was monitored and was permanent in the 4 patients in whom conduction was not monitored during energy delivery. The remaining patient was noted to have LAA isolation during a redo procedure before any ablation. Nine of (82%) the 11 patients have remained arrhythmia-free without antiarrhythmic drugs at mean follow-up of 6 +/- 7 months, and all have continued taking warfarin., Conclusion: Electrical isolation of the LAA may occur during ablation of persistent AF and AT even when the ablation site is remote from the LAA. This likely is due to disruption of the Bachmann bundle and its leftward extension, which courses along the anterior left atrium and bifurcates to surround the LAA. Monitoring of LAA conduction during ablation of persistent AF or AT is important in avoiding permanent LAA isolation.
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- 2010
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17. Confirmatory factor analysis and sample invariance of the Chinese Patient Satisfaction Questionnaire (ChPSQ-9) among patients with breast and lung cancer.
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Wong WS, Fielding R, Wong C, and Hedley A
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- Adult, Aged, Aged, 80 and over, China, Female, Humans, Longitudinal Studies, Male, Middle Aged, Models, Statistical, Nurses, Physicians, Reproducibility of Results, Statistics as Topic, Breast Neoplasms, Factor Analysis, Statistical, Lung Neoplasms, Patient Satisfaction statistics & numerical data, Surveys and Questionnaires standards
- Abstract
Objectives: Previous exploratory factor analysis of the 9-item Chinese Patient Satisfaction Questionnaire (ChPSQ-9) identified two dominant factors: doctor and nurse. The present study employed confirmatory factor analysis (CFA) to examine the factorial invariance of the ChPSQ-9 between and within samples of Chinese patients with breast or lung cancer., Methods: Longitudinal data were analyzed from Chinese breast and lung cancer patients who had completed the ChPSQ-9 during their first outpatient visit, at 3 months, and at 6 months after baseline. CFAs tested the fit of a one-factor model, a hierarchical model that comprised a general latent factor and two first-order factors, and a correlated model that comprised two correlated first-order factors to the data. The factorial invariance of the ChPSQ-9 between six independent samples across time was investigated using multigroup CFAs., Results: The CFA's results demonstrated a better fit of the correlated model over the one-factor model and the hierarchical model in the breast and lung cancer samples. The correlated model showed evidence of cross-sample and longitudinal factorial invariance. Patients were generally satisfied with services provided by doctors and nurses. Internal consistency of the scale was also good for both cancer samples across time., Conclusions: The ChPSQ-9 is a valid and reliable instrument to be employed among breast and lung cancer patients, in clinical settings or intervention research, to evaluate group differences in patient satisfaction and its association with intervention effectiveness.
- Published
- 2009
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18. Relationship between the spectral characteristics of atrial fibrillation and atrial tachycardias that occur after catheter ablation of atrial fibrillation.
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Yoshida K, Chugh A, Ulfarsson M, Good E, Kuhne M, Crawford T, Sarrazin JF, Chalfoun N, Wells D, Boonyapisit W, Veerareddy S, Billakanty S, Wong WS, Jongnarangsin K, Pelosi F Jr, Bogun F, Morady F, and Oral H
- Subjects
- Atrial Fibrillation physiopathology, Body Surface Potential Mapping methods, Catheter Ablation methods, Female, Follow-Up Studies, Heart Rate, Humans, Male, Middle Aged, Monitoring, Intraoperative methods, Prognosis, Signal Processing, Computer-Assisted, Tachycardia, Ectopic Atrial diagnosis, Tachycardia, Ectopic Atrial physiopathology, Atrial Fibrillation surgery, Catheter Ablation adverse effects, Tachycardia, Ectopic Atrial etiology
- Abstract
Background: During catheter ablation of complex fractionated atrial electrograms, persistent atrial fibrillation (AF) may convert to an atrial tachycardia (AT)., Objective: The purpose of this study was to investigate the possible mechanisms of AT by examining the spectral and electrophysiologic characteristics of AF and ATs that occur after catheter ablation of AF., Methods: The subjects of this study were 33 consecutive patients with persistent AF who had conversion of AF to AT during ablation of AF (group I) and 20 consecutive patients who underwent ablation of persistent AT that developed more than 1 month after AF ablation (group II). Spectral analysis of the coronary sinus (CS) electrograms and lead V(1) was performed during AF at baseline, before conversion, and during AT. The spatial relationship between the AT mechanism and ablation sites was examined., Results: A spectral component with a frequency that matched the frequency of AT was present in the baseline periodogram of AF more often in group I (52%) than in group II (20%, P = .02). Ablation resulted in a decrease in the dominant frequency of AF but not in the frequency of the spectral component that matched the AT. There was a significant direct relationship between the baseline dominant frequency of AF and the frequency of AT in the CS in group I (r = 0.76, P <.0001) but not in group II (r = 0.38, P = .09). ATs were macroreentrant in 64% and 60% of patients in groups I and II, respectively (P = .8). The AT site was more likely to be distant (>1 cm) from AF ablation sites in group I (70%) than in group II (35%, P = .007)., Conclusion: The findings of this study suggest that ATs observed during ablation of AF often may be drivers of AF that become manifest after elimination of higher-frequency sources and fibrillatory conduction.
- Published
- 2009
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19. 4q loss is potentially an important genetic event in MM tumorigenesis: identification of a tumor suppressor gene regulated by promoter methylation at 4q13.3, platelet factor 4.
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Cheng SH, Ng MH, Lau KM, Liu HS, Chan JC, Hui AB, Lo KW, Jiang H, Hou J, Chu RW, Wong WS, Chan NP, and Ng HK
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- Aged, Aged, 80 and over, Alleles, Cell Line, Tumor, Cell Transformation, Neoplastic pathology, Chromosomes, Human, Pair 13 genetics, Disease Progression, Female, Gene Deletion, Gene Expression Regulation, Neoplastic, Humans, In Situ Hybridization, Male, Middle Aged, Multiple Myeloma pathology, RNA, Messenger genetics, Transcription, Genetic genetics, Cell Transformation, Neoplastic genetics, Chromosomes, Human, Pair 4 genetics, DNA Methylation, Multiple Myeloma genetics, Platelet Factor 4 genetics, Promoter Regions, Genetic genetics, Tumor Suppressor Proteins genetics
- Abstract
In this study, we have elucidated the chromosomal imbalances in the multistep pathogenesis and delineated several critical tumor suppressor gene (TSG) loci in multiple myeloma (MM). By using comparative genomic hybridization, allelotyping, and multicolor interphase fluorescence in situ hybridization, 5 MM cell lines and bone marrow CD138+ plasma cells from 88 Chinese patients with monoclonal gammopathy of undetermined significance (MGUS) and early and advanced stages of MM were investigated. In all MGUS and MM samples, chromosome copy number abnormalities were detected. A higher number of chromosomal imbalances and specific genetic alterations are involved in MGUS to MM transition (-6q, +3p, and +1p) and MM progression (+2p and +9q). In addition to -13q, we first found high frequencies (42% to 46%) of -4q involving high percentages (70% to 74%) of clonal plasma cells in both MGUS and MM, suggesting that inactivation of TSG in this region is also a potentially critical genetic event in MM tumorigenesis. By high-resolution allelotyping, we defined a common deletion region on 4q13.3 and found that a candidate TSG, platelet factor 4, was frequently silenced by promoter hypermethylation in MM (15 of 28) and MM cell lines (5 of 5). These data have opened up a new approach in the molecular targeting therapy and provide novel insights into MM tumorigenesis.
- Published
- 2007
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- View/download PDF
20. Outsourced teleradiology imaging services: an analysis of discordant interpretation in 124,870 cases.
- Author
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Wong WS, Roubal I, Jackson DB, Paik WN, and Wong VK
- Subjects
- California, Clinical Competence, Diagnostic Imaging methods, Female, Health Care Surveys, Humans, Male, Outsourced Services statistics & numerical data, Program Evaluation, Remote Consultation, Reproducibility of Results, Retrospective Studies, Teleradiology statistics & numerical data, Diagnostic Errors statistics & numerical data, Diagnostic Imaging standards, Outsourced Services standards, Quality Assurance, Health Care, Teleradiology standards
- Abstract
Purpose: Outsourcing after-hours radiology coverage to a teleradiology coverage company has become common in recent years. However, concerns have been raised over the quality of these types of coverage and the implications on patient care. This study details the quality assurance program of a teleradiology company that provides after-hours coverage to 64 California hospitals., Method: The records of all examinations interpreted by 10 radiologists during 2003 were reviewed. Interpretations were compared with the final interpretations of the host practices and evaluated for timeliness., Results: A total of 124,870 radiologic studies were interpreted by 10 teleradiologists during 2003. Computed tomography (CT) comprised 74% of these examinations: CT head (35%) examinations were the most commonly transmitted examinations, and CT abdomen/pelvis examinations were the second most common studies (27%). The average turnaround time was 12.2 min; 93% of the examinations were reported within 30 min, and 99% were completed within 1 hour. The overall discordant rate for individual teleradiologists ranged from 0.70% to 1.41%, with an average of 1.09%. Of the most commonly ordered examinations, CT of the abdomen/pelvis had the highest rate of discordance, at 2.1%., Conclusions: Outsourcing to a teleradiology program with an active quality-assurance program can be safe. An active quality-assurance program should be an integral component of any teleradiology program. Constant feedback improves the performance of the radiologists.
- Published
- 2005
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- View/download PDF
21. Intravenous leiomyomatosis: two cases with different routes of tumor extension.
- Author
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Lam PM, Lo KW, Yu MY, Wong WS, Lau JY, Arifi AA, and Cheung TH
- Subjects
- Adult, Female, Heart Atria, Heart Neoplasms epidemiology, Humans, Leiomyomatosis epidemiology, Middle Aged, Uterine Neoplasms epidemiology, Vascular Neoplasms epidemiology, Heart Neoplasms pathology, Leiomyomatosis pathology, Uterine Neoplasms pathology, Vascular Neoplasms pathology, Vena Cava, Inferior
- Abstract
Intravenous leiomyomatosis is a rare smooth muscle tumor. We report two cases of intravenous leiomyomatosis that grew along different routes of the venous system into the inferior vena cava and the right atrium. The different route of extension makes a difference in the ease of excision of tumor masses. Using MEDLINE together with the references in each publication, we identified all cases of intracardiac leiomyomatosis reported in the English literature in the period between 1980 and 2003 and performed a brief review on this potentially lethal disease entity.
- Published
- 2004
- Full Text
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22. IL-10 synergistically enhances GM-CSF-induced CCR1 expression in myelomonocytic cells.
- Author
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Li H, Cheung W, Choo HH, Chan JH, Lai PS, and Fred Wong WS
- Subjects
- Chemokine CCL3, Chemokine CCL4, Chemotaxis, Leukocyte, Drug Synergism, Enzyme Inhibitors pharmacology, Gene Expression Regulation, Humans, Macrophage Inflammatory Proteins pharmacology, Mitogen-Activated Protein Kinases metabolism, Monocytes drug effects, Myeloid Cells drug effects, Myeloid Cells immunology, Phosphorylation, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-akt, RNA, Messenger biosynthesis, Receptors, CCR1, Receptors, Chemokine genetics, Ribosomal Protein S6 Kinases, 70-kDa metabolism, Signal Transduction drug effects, U937 Cells, Granulocyte-Macrophage Colony-Stimulating Factor pharmacology, Interleukin-10 pharmacology, Monocytes immunology, Protein Serine-Threonine Kinases, Receptors, Chemokine biosynthesis
- Abstract
CC chemokine receptor 1 (CCR1) has been implicated in inflammation. The present study examined the signaling mechanisms that mediate GM-CSF/IL-10-induced synergistic CCR1 protein expression in monocytic U937 cells. GM-CSF alone markedly increased both the mRNA and protein expression of CCR1. IL-10 augmented GM-CSF-induced CCR1 protein expression with no effect on mRNA expression. PD098059 and U0126 (two MEK inhibitors), and LY294002 (a PI3K inhibitor) inhibited GM-CSF/IL-10-induced CCR1 gene and protein expression. PD098059, U0126, and LY294002 also attenuated chemotaxis of GM-CSF/IL-10-primed U937 cells in response to MIP-1alpha. Immunoblotting studies show that GM-CSF alone induced ERK2 phosphorylation; whereas, IL-10 alone induced p70(S6k) phosphorylation in U937 cells. Neither cytokine when used alone induced PKB/Akt phosphorylation. Combined GM-CSF/IL-10 treatment of U937 cells induced phosphorylation of ERK2, p70(S6k), and PKB/Akt. PD098059 and U0126 completely abrogated ERK2 phosphorylation; whereas, LY294002 completely blocked PKB/Akt and p70(S6k) phosphorylation. Our findings indicate that IL-10 may potentiate GM-CSF-induced CCR1 protein expression in U937 cells via activation of PKB/Akt and p70(S6k).
- Published
- 2003
- Full Text
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23. Inhibitors of the tyrosine kinase signaling cascade attenuated thrombin-induced guinea pig airway smooth muscle cell proliferation.
- Author
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Tsang F, Choo HH, Dawe GS, and Wong WS
- Subjects
- Animals, Cell Survival drug effects, Cells, Cultured, Chromones pharmacology, Cyclin D1 genetics, DNA Replication, Flavonoids pharmacology, Guinea Pigs, MAP Kinase Signaling System drug effects, Male, Morpholines pharmacology, Muscle, Smooth drug effects, Respiratory Physiological Phenomena, Thymidine metabolism, Cell Division drug effects, Enzyme Inhibitors pharmacology, MAP Kinase Signaling System physiology, Muscle, Smooth physiology, Protein-Tyrosine Kinases antagonists & inhibitors, Thrombin pharmacology
- Abstract
Airway remodeling is one of the major hallmarks of asthma. The present study examined the effects of tyrosine kinase inhibitors on thrombin-induced guinea pig ASM cell proliferation, in comparison with inhibitors of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K). The ASM cells expressed smooth muscle alpha-actin and myosin, and responded to thrombin by increasing cytosolic Ca(+2). Thrombin (1-10 U/ml) induced [(3)H]thymidine incorporation into ASM cells. Tyrphostin 47, a broad-spectrum tyrosine kinase inhibitor, PP2, a Src-specific inhibitor, and piceatannol, a Syk-selective inhibitor, significantly attenuated thrombin-induced [(3)H]thymidine incorporation. In addition, the tyrosine kinase inhibitors significantly reduced thrombin-induced cyclin D(1) expression in ASM cells. PD098059 and U0126, two MAPK kinase inhibitors, and LY294002, a PI3K inhibitor, significantly blocked thrombin-induced [(3)H]thymidine incorporation and cyclin D(1) expression in ASM cells. Our data show that inhibitors of Src and, probably Syk, can modulate thrombin-induced ASM cell proliferation, which may have therapeutic potential for asthma.
- Published
- 2002
- Full Text
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24. Pertussis toxin activates tyrosine kinase signaling cascade in myelomonocytic cells: a mechanism for cell adhesion.
- Author
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Li H and Wong WS
- Subjects
- Cell Adhesion drug effects, Chromones pharmacology, Dimethyl Sulfoxide pharmacology, Flavonoids pharmacology, Genistein pharmacology, Humans, Kinetics, Lipopolysaccharide Receptors drug effects, Lipopolysaccharide Receptors physiology, MAP Kinase Signaling System physiology, Mitogen-Activated Protein Kinase 1 metabolism, Mitogen-Activated Protein Kinases metabolism, Morpholines pharmacology, Phosphorylation, Phosphotyrosine metabolism, Signal Transduction physiology, Transforming Growth Factor beta pharmacology, Tyrphostins pharmacology, U937 Cells, Cell Adhesion physiology, Enzyme Inhibitors pharmacology, MAP Kinase Signaling System drug effects, Pertussis Toxin, Protein-Tyrosine Kinases metabolism, Signal Transduction drug effects, Virulence Factors, Bordetella pharmacology
- Abstract
Pertussis toxin (PTX) has recently been shown to specifically bind to CD14 to promote myelomonocytic cell adhesion to serum. The present study investigated the signaling mechanisms responsible for PTX-induced differentiated U937 cell adhesion. PTX-induced myelomonocytic cell adhesion was blocked by genistein or tyrphostin-47 (two protein tyrosine kinase inhibitors), LY294002 (a phosphatidylinositol 3-kinase (PI3K) inhibitor), or PD098059 (a mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor). PTX induced a rapid tyrosine phosphorylation of several discrete cytoplasmic proteins, which could be inhibited by genistein or tyrphostin 47. In addition, PTX induced phosphorylation of Akt and of ERK2, which could be completely blocked by LY294002 and PD098059, respectively, and by genistein or tyrphostin 47 as well. All of these PTX-induced signaling events could be reproduced using purified PTX B-oligomer (PTX-B) alone. Our data show that PTX can activate tyrosine kinase signaling cascade, including the downstream PI3K and ERK/MAPK pathways, in myelomonocytic cells to induce cell adhesion to serum., (Copyright 2001 Academic Press.)
- Published
- 2001
- Full Text
- View/download PDF
25. Effects of phenolic antioxidants and flavonoids on DNA synthesis in rat liver, spleen, and testis in vitro.
- Author
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Wong WS and McLean AE
- Subjects
- Animals, Dose-Response Relationship, Drug, Hydroxyurea pharmacology, In Vitro Techniques, Liver metabolism, Male, Nucleic Acid Synthesis Inhibitors pharmacology, Rats, Rats, Wistar, Spleen metabolism, Testis metabolism, Acetaminophen pharmacology, Antioxidants pharmacology, DNA antagonists & inhibitors, DNA biosynthesis, Flavonoids pharmacology, Liver drug effects, Phenols pharmacology, Spleen drug effects, Testis drug effects
- Abstract
Paracetamol (acetaminophen) and hydroxyurea were found to inhibit DNA synthesis in a dose-dependent manner in tissue slices in vitro, with little effect on protein synthesis. Considerable variation in the sensitivity of the different tissues was also observed with an order of least sensitive to most sensitive tissue of liver < testis < spleen. The phenolic antioxidant properties of paracetamol are thought to be the mechanism by which paracetamol inhibits DNA synthesis, which led us to study other phenolic antioxidant molecules and flavonoids for specific inhibition of DNA synthesis. (+)-catechin, m-aminophenol, p-aminophenol and p-cresol all displayed a highly specific inhibition of DNA synthesis. Quercetin displayed a preferential inhibition of DNA synthesis but a significant level of inhibition of protein synthesis was also seen. Nordihydroguaiaretic acid (NDGA) and n-propyl gallate showed preferential inhibition of DNA synthesis at the lower doses tested, but at higher doses showed significant inhibition of protein synthesis, presumably because of cytotoxicity. Caffeic acid and naringenin did not display any specific inhibition of DNA synthesis as protein synthesis was equally inhibited at all doses tested. This study demonstrates that certain phenolic antioxidants can inhibit DNA synthesis specifically but this is not a property shared by all phenolic antioxidants; and that these inhibitors show considerable variation in effectiveness between different tissues.
- Published
- 1999
- Full Text
- View/download PDF
26. Effect of melatonin on chloride secretion by human colonic T84 cells.
- Author
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Chan HC, Lui KM, Wong WS, and Poon AM
- Subjects
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid pharmacology, Adenylate Cyclase Toxin, Adenylyl Cyclase Inhibitors, Adenylyl Cyclases metabolism, Calcium Channel Blockers pharmacology, Cell Line, Chloride Channels antagonists & inhibitors, Chloride Channels metabolism, Colon cytology, Colon metabolism, Dose-Response Relationship, Drug, GTP-Binding Protein alpha Subunits, Gi-Go metabolism, Humans, Imines pharmacology, Melatonin analogs & derivatives, Receptors, Cell Surface metabolism, Receptors, Cytoplasmic and Nuclear metabolism, Receptors, Melatonin, Virulence Factors, Bordetella pharmacology, ortho-Aminobenzoates pharmacology, Chlorides metabolism, Colon drug effects, Melatonin pharmacology
- Abstract
The effect of melatonin on human colonic T84 cells was studied using the short-circuit current (I(SC)) technique. Basolateral, as well as apical, addition of melatonin stimulated I(SC) in a concentration-dependent manner (EC50 at about 100 microM). The I(SC) response to melatonin was nearly abolished when external Cl- was removed. The increase in I(SC) was also blocked by apical addition of two Cl- channel blockers, 4,4'-diisothiocyanatostibene-2,2'-disulfonic acid (DIDS) and diphenylamine-2-carboxylic acid (DPC), indicating that melatonin stimulated Cl- secretion. The effect of different melatonin analogs was compared and the order of potency appeared to be 2-iodomelatonin > melatonin > 6-hydroxymelatonin, indicating the involvement of melatonin receptors. However, inhibitors for Gi-protein, adenylate cyclase or phospholipase C were found to be ineffective in inhibiting the melatonin-induced I(SC). Pretreatment of the cells with melatonin was also found to exert little effect on subsequent forskolin- or VIP-induced I(SC), further excluding its interaction with adenylate cyclase. Our data suggest that melatonin may play a role in regulating colonic Cl- secretion via melatonin receptors; however, the signal transduction pathway(s) involved remains to be elucidated.
- Published
- 1998
- Full Text
- View/download PDF
27. Signaling mechanisms of pertussis toxin-induced myelomonocytic cell adhesion: role of tyrosine phosphorylation.
- Author
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Wong WS and Luk JM
- Subjects
- Calcitriol pharmacology, Calcium metabolism, Calcium Channel Blockers pharmacology, Cell Differentiation drug effects, Genistein, Humans, Isoflavones pharmacology, Lipopolysaccharides pharmacology, Phosphorylation, Phosphotyrosine metabolism, Signal Transduction, Transforming Growth Factor beta pharmacology, Tumor Cells, Cultured, Cell Adhesion drug effects, Macrophage-1 Antigen physiology, Monocytes cytology, Pertussis Toxin, Virulence Factors, Bordetella pharmacology
- Abstract
Pertussis toxin (PTX) was thought to bind Mac-1 integrin receptor (CD11b/CD18) on TGF-beta1/D3-primed U937 cells and induced cellular adhesion to serum-coated plate. The present study was to investigate the signal transduction pathway utilized by PTX to initiate myeloid cell adhesion in serum. Immunoblotting study showed that PTX induced tyrosine phosphorylation of two cytoplasmic proteins of 150 kDa and 90 kDa in TGF-beta1/D3-primed U937 cells in a time-dependent manner. In addition, PTX-induced myelomonocytic cell adhesion was abolished in the presence of genistein (100 microM), a specific tyrosine kinase inhibitor. 2LPM19c (2 microg/ml), a mouse monoclonal antibody against the CD11b subunit of Mac-1 integrin, or ethylenediamine tetraacetic acid (EDTA, 5 mM) prevented PTX-mediated U937 cell adhesion. On the other hand, nifedipine (1 microM), a calcium channel blocker, significantly reduced PTX-induced U937 cell adhesion. Taken together, it is suggested that binding of PTX to Mac-1 integrin receptor on primed U937 cells triggers protein tyrosine phosphorylation and, to a lesser extent, Ca(+2) influx, which eventually lead to monocytic cell adhesion in serum.
- Published
- 1997
- Full Text
- View/download PDF
28. A comparison of the apical seals achieved using retrograde amalgam fillings and the Nd:YAG laser.
- Author
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Wong WS, Rosenberg PA, Boylan RJ, and Schulman A
- Subjects
- Apicoectomy methods, Bismuth, Chi-Square Distribution, Dental Alloys, Drug Combinations, Evaluation Studies as Topic, Humans, Methenamine, Pilot Projects, Root Canal Filling Materials, Silver, Streptococcus, Titanium, Dental Amalgam, Dental Leakage, Dentin radiation effects, Epoxy Resins, Laser Therapy, Retrograde Obturation methods
- Abstract
The purpose of this in vitro study was to compare the apical seals achieved using retrograde amalgam fillings or the Nd:YAG laser. Freshly extracted teeth were randomly separated into groups that would have their apices treated either with a Nd:YAG laser or retrograde amalgam. After instrumentation and obturation, bacterial reservoirs were prepared in the coronal portion of canals. Teeth to receive retrofillings had their apices prepared and amalgams placed. Teeth to be lasered had no apical preparations. Teeth and culture media were then sterilized by irradiation. Streptococcus salivarius was deposited in the opened bacterial reservoirs. At intervals, culture media with an indicator in culture chambers was observed for color change. Specimens that demonstrated color change were cultured for S. salivarius. Under the conditions of this in vitro study, no statistically significant difference was found in bacterial leakage between the laser-treated group and the retrograde amalgam group.
- Published
- 1994
- Full Text
- View/download PDF
29. Antiulcer activity of the calcium antagonist propyl-methylenedioxyindene. IV. Effects on gastric lesions in rats induced by cold-restraint stress and thyrotropin-releasing hormone.
- Author
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Wong WS, Rahwan RG, and Stephens RL Jr
- Subjects
- Animals, Cold Temperature, Gastric Acid metabolism, Gastric Emptying drug effects, Gastric Juice drug effects, Male, Pyrrolidonecarboxylic Acid analogs & derivatives, Rats, Rats, Inbred Strains, Restraint, Physical, Stomach Ulcer chemically induced, Stomach Ulcer etiology, Thyrotropin-Releasing Hormone analogs & derivatives, Thyrotropin-Releasing Hormone pharmacology, Anti-Ulcer Agents therapeutic use, Calcium Channel Blockers therapeutic use, Indenes therapeutic use, Stomach Ulcer drug therapy, Stress, Psychological
- Abstract
Propyl-methylenedioxyindene (pr-MDI; 30 mg/kg, i.p.), an intracellular calcium antagonist, significantly reduced the number and size of erosions per stomach induced by cold-restraint stress by 69% and 86%, respectively. Our previous findings indicate that the antiulcer activity of pr-MDI is highly correlated with its inhibitory effect on gastric motor activity. Since central TRH is suggested as the brain mediator responsible for cold-restraint stress gastric ulcers in rats, the inhibitory action of pr-MDI was evaluated in the TRH-induced gastric lesion model. Pr-MDI (30 mg/kg) did not reduce the gastric erosions induced by intracisternal administration of 100ng RX77368, a stable thyrotropin-releasing hormone (TRH) analogue, even though it abolished the RX77368-induced stimulation of gastric emptying, gastric acidity, and acid output. Since pr-MDI (30 mg/kg, i.p.) significantly inhibited the stimulation of gastric motility by both cold-restraint stress and TRH, but only cold-restraint stress-induced gastric erosions were effectively reduced by the drug, the present findings suggest a possible dissociation between the ulcerogenic mechanisms of cold-restraint stress and intracisternal administration of TRH.
- Published
- 1990
- Full Text
- View/download PDF
30. A microcomputer based interview system for antenatal clinic.
- Author
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Wong WS, Lee KH, and Chang MZ
- Subjects
- Female, Humans, Medical History Taking, Microcomputers, Outpatient Clinics, Hospital, Pregnancy, Software, Computer Systems, Interviews as Topic, Obstetrics
- Abstract
A microcomputer-based antenatal interview system, using a low cost Apple IIb computer with an on-line printer, was tested for the feasibility of application in an obstetric clinic. This simple to use interview program was written in the PASCAL language. This paper describes the development and features of this program.
- Published
- 1986
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- View/download PDF
31. A comparison of methods for quantitating fetal heart rate variability.
- Author
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Laros RK Jr, Wong WS, Heilbron DC, Parer JT, Shnider SM, Naylor H, and Butler J
- Subjects
- Analog-Digital Conversion, Data Display, Female, Fetal Distress diagnosis, Humans, Mathematics, Methods, Pregnancy, Statistics as Topic, Diagnosis, Computer-Assisted, Electrocardiography methods, Fetal Heart, Heart Rate
- Abstract
Fetal heart rate (FHR) variability is thought to be an important index of fetal health. In the presence of normal variability, the fetus is vigorous, but lack of beat-to-beat variability may be associated with fetal compromise. A distinction between short-term variability (STV) (beat-to-beat changes between successive beats) and long-term variability (LTV) (rhythmic fluctuations in FHR) has not been made to date. We have utilized computer programs to compare three pairs of mathematical indices and one visual index of FHR variability. Among the three pairs of indices designed for detection of STV and LTV, de Haan's short-term and long-term indices exhibited the least interdependence, and the long-term index was completely insensitive to artifically generated pure STV. Yeh's short-term and long-term indices exhibited substantial positive interdependence. Hon's visual index appears to detect LTV primarily rather than STV. When the effect of progression of labor on FHR variability was examined, no conclusions were possible because of inconsistencies between patients. Ultimately, the clinical value of any one of these indices awaits testing of their ability to define fetal well-being or fetal distress.
- Published
- 1977
- Full Text
- View/download PDF
32. Pyridine borane as a reducing agent for proteins.
- Author
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Wong WS, Osuga DT, and Feeney RE
- Subjects
- Alkylation, Amino Acids analysis, Carbohydrates, Chemical Phenomena, Chemistry, Lysine, Methylation, Oxidation-Reduction, Serum Albumin, Bovine, Trifluoroacetic Acid, Tryptophan, Boranes, Boron Compounds, Indicators and Reagents, Proteins, Pyridines
- Abstract
Pyridine borane has been reported as a superior reagent over a wide pH range, 5-9, for the reductive methylation of amino groups of proteins with formaldehyde [J. C. Cabacungan , A. I. Ahmed , and R. E. Feeney (1982) Anal. Biochem. 124, 272-278]. It has also been reported to reduce tryptophan to dihydrotryptophan and to inactivate lysozyme in trifluoroacetic acid [M. Kurata , Y. Kikugawa , T. Kuwae , I. Koyama , and T. Takagi (1980) Chem. Pharm . Bull 28, 2274-2275]. In the present study the specificity of pyridine borane for the two different modifications under different reaction conditions has been demonstrated, and extended to the application to the synthesis of protein containing reductively attached carbohydrates. In the acid reduction, pyridine borane selectively reduced all six tryptophans in lysozyme to dihydrotryptophan while all other amino acids remained intact. On similar treatment no cleavage of the carbohydrate moiety from chicken ovomucoid, and no losses of activity of ovomucoid or ribonuclease, two proteins devoid of tryptophan, were observed. Nearly complete methylation of the lysines of lysozyme, chicken ovomucoid, and ribonuclease was achieved with formaldehyde at pH 7.0 after 2 h at room temperature, with the retention of full activity of the protein without any destruction of tryptophan. The same chemistry was applied to covalently attach glucose and lactose to bovine serum albumin. Parameters, including pH, temperature, and methanol, that affect the reactions were investigated. Incremental additions of pyridine borane during the course of the reactions increased the rate of modification. The covalent attachment of sugar to the epsilon-amino group of lysine was demonstrated by the synthesis of N-alpha- acetylglucitollysine and comparison with acid hydrolysates of the bovine serum albumin-sugar derivatives.
- Published
- 1984
- Full Text
- View/download PDF
33. Determination of tryptophan as the reduced derivative by acid hydrolysis and chromatography.
- Author
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Wong WS, Osuga DT, Burcham TS, and Feeney RE
- Subjects
- Chemical Phenomena, Chemistry, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Hydrolysis, Oxidation-Reduction, Sulfhydryl Compounds, Tryptophan analogs & derivatives, Amino Acids analysis, Proteins analysis, Tryptophan analysis
- Abstract
A new procedure for the analyses of tryptophan and the total amino acid composition of proteins was based on the observations that pyridine borane reduces tryptophan in trifluoroacetic acid, while other amino acids remain intact [M. Kurata, Y. Kikugawa, T. Kuwae, I. Koyama, and T. Takagi (1980) Chem. Pharm. Bull. 28, 2274-2275; W.S.D. Wong, D.T. Osuga, and R.E. Feeney (1984) Anal. Biochem. 139, 58-67]. Concentrated HCl was used instead of trifluoroacetic acid for analytical purposes. The products were stable to hydrolysis in 6 N HCl, and the reduction did not interfere with hydrolysis and subsequent analyses. Quantitative recovery was achieved with most proteins when they were subjected to acid reduction in ice-cooled concentrated HCl with two incremental additions of pyridine borane. The reaction was terminated after 10 min by dilution with an equal volume of H2O, vacuum sealing, and hydrolyzing at 110 degrees C for 22 h. The yields of the expected values for cytochrome c, catalase, bovine serum albumin, subtilisin BPN', trypsin, chymotrypsin, beta-lactoglobulin, lysozyme, and pepsin were obtained. Ovotransferrin and ovalbumin, however, yielded values for tryptophan lower than literature values. With two different ion-exchange methods, the recoveries of all other amino acids were comparable to those obtained by acid hydrolysis with 6 N HCl. Since the same hydrolysate can be analyzed for both tryptophan and all the other amino acids, the procedure is a more convenient method than those requiring separate determinations. Initial results indicate that the method may be applied to high-performance liquid chromatographic procedures with adaptations of the protocols if necessary.
- Published
- 1984
- Full Text
- View/download PDF
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