Biomedical subjects

Winnie Wong

Publications and source records attributed to Winnie Wong.

5 recordsLinked to original sources

PubMed2006

Acute management and secondary prophylaxis of esophageal variceal bleeding: a western Canadian survey.

BACKGROUND: Acute esophageal variceal bleeding (EVB) is a major cause of morbidity and mortality in patients with liver cirrhosis. Guidelines have been published in 1997; however, variability in the acute management and prevention of EVB rebleeding may occur. METHODS: Gastroenterologists in the provinces of British Columbia, Alberta, Manitoba and Saskatchewan were sent a self-reporting questionnaire. RESULTS: The response rate was 70.4% (86 of 122). Intravenous octreotide was recommended by 93% for EVB patients but the duration was variable. The preferred timing for endoscopy in suspected acute EVB was within 12 h in 75.6% of respondents and within 24 h in 24.6% of respondents. Most (52.3%) gastroenterologists do not routinely use antibiotic prophylaxis in acute EVB patients. The preferred duration of antibiotic therapy was less than three days (35.7%), three to seven days (44.6%), seven to 10 days (10.7%) and throughout hospitalization (8.9%). Methods of secondary prophylaxis included repeat endoscopic therapy (93%) and beta-blocker therapy (84.9%). Most gastroenterologists (80.2%) routinely attempted to titrate beta-blockers to a heart rate of 55 beats/min or a 25% reduction from baseline. The most common form of secondary prophylaxis was a combination of endoscopic and pharmacological therapy (70.9%). CONCLUSIONS: Variability exists in some areas of EVB treatment, especially in areas for which evidence was lacking at the time of the last guideline publication. Gastroenterologists varied in the use of prophylactic antibiotics for acute EVB. More gastroenterologists used combination secondary prophylaxis in the form of band ligation eradication and beta-blocker therapy rather than either treatment alone. Future guidelines may be needed to address these practice differences.

Acute Disease↗

PubMed2005

Update on chronic hepatitis C.

The burden of chronic hepatitis C infection remains significant in the United States and worldwide. Increased knowledge regarding the natural history of acute and chronic infection and the key factors responsible for disease progression, risk for cirrhosis, and risk for hepatocellular carcinoma are critical in guiding secondary and tertiary prevention measures. The past decade has seen substantial improvement of antiviral therapy for chronic hepatitis C virus with an increasing number of individuals achieving viral eradication. Decisions regarding whom, when, and how to use antiviral therapy have become more complex and change as new studies become available. This review focuses on the current status of hepatitis C virus patient management and future treatment directions.

Antiviral Agents↗

PubMed2003

Labour force participation among individuals with hepatitis C in the US.

BACKGROUND: In 1996, the number of persons newly infected with hepatitis C virus (HCV) in the US was estimated to be 36 000. As a chronic disease that primarily affects younger persons, hepatitis C has the potential to influence employment considerably. OBJECTIVE: To estimate employment effects associated with hepatitis C morbidity. DESIGN: An economic model of labour supply, which used the outcome measure workforce participation (yes/no), was applied. STUDY PARTICIPANTS: The study samples (by gender) were comprised of persons 18-65 years of age, with and without serological evidence of HCV infection, and with normal or elevated levels of alanine aminotransferase (ALT) who participated in the National Health and Nutrition Examination Survey III from 1988-1994. RESULTS: After controlling for the potential confounding effects of demographic, social, and economic factors, positive HCV status/normal ALT level in males was associated with a 10.7% reduction in labour force participation (when compared with negative HCV status). Positive HCV status and elevated ALT levels was associated with a 17.5% reduction in employment. The results for females were not statistically significant. CONCLUSIONS: Nationally, the employment response for HCV-positive status and elevated ALT levels translates into an excess non-employment of 48 000 males annually.

Adolescent↗

PubMed2002

Ultrasound biomicroscopy of the anterior segment of the enucleated chicken eye during accommodation.

Ultrasound biomicroscopy produces real-time two-dimensional images of ocular structures measured non-invasively. Given recent work which shows that lenses from myopic eyes show shorter focal lengths and reduced accommodative amplitudes compared with controls, this study was undertaken to determine the structural characteristics of the anterior segment of chicken eyes during accommodation using the ultrasound biomicroscope (UBM). Form-deprivation myopia and hyperopia were induced in hatching chicks by the application of either translucent or +15 D defocus goggles. After 7 days, eyes were enucleated and ultrasound biomicrographs of the eye, at rest and during ciliary nerve-stimulated accommodation, were collected. For all eyes, accommodation was associated with a decrease in anterior chamber depth, an increase in lenticular thickness and a steepening of the front lenticular surface curvature. Changes related to refractive error were more difficult to detect. Myopic eyes showed deeper anterior chamber depths and differences in lenticular thicknesses just above the resolution limit for detection. In +15 D lens-treated eyes, anterior chamber differences were opposite but smaller, just at the limit of resolution, while differences in mean lenticular thickness were not resolvable at a pixel or above. The UBM is a good tool for measuring robust changes during accommodation, but is limited in its ability to detect subtle changes associated with experimentally induced ametropias.

Accommodation, Ocular↗

PubMed2002

Blood pressure measurement in noise intensive environments using adaptive interference cancellation.

The traditional auscultatory technique and current methodologies for measuring human blood pressure are limited when used in situations where extreme vibration or acoustic noise is present. In this study, human subjects were used to establish the effectiveness of a novel adaptive blood pressure monitoring (ABPM) system in determining systolic-diastolic pressure in vibration and noise intense environments. To remove the effects of noise and vibration from the audible Korotkoff sounds, the proposed ABPM system employs two acoustic sensors in the pressure cuff. The primary acoustic sensor is placed on the brachial artery to record the Korotkoff sounds while the secondary acoustic sensor is placed away from the artery to record background noise and vibrations. The signals from the two acoustic sensors are provided to the input of an adaptive interference canceller to remove the noise effects in the signal of the primary acoustic sensor. In two phases of clinical testing, the ABPM system was first employed in a noiseless environment and then near and onboard search and rescue helicopters. The results from both phases deliver a successful demonstration of the ABPM system's capabilities to provide blood pressure estimates in noisy environments where the conventional auscultatory and other techniques have limited use.

Adult↗