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Biomedical subjects

J Wong

Publications and source records attributed to J Wong.

At least 55 records · Page 3Linked to original sources
PubMed2004

Health-related quality of life (HRQL) scores reported from parents and their children with chronic illness differed depending on utility elicitation method.

OBJECTIVE: To describe the relationship between health-related quality of life (HRQL) as measured by utility when elicited from parents and their children with chronic illness. STUDY DESIGN AND SETTING: We enrolled families of children admitted for cancer chemotherapy and those attending outpatient rheumatology, hemophilia and bone marrow transplantation clinics. Children in grade 6 or higher were included. The child's HRQL was rated by parent and child using the Standard Gamble (SG), Visual Analogue Scale (VAS), Time Trade-Off (TTO), and Health Utilities Index Mark 2/3 (HUI2 and HUI3). RESULTS: 22 families were included. The mean parent SG was 0.92 +/- 0.09, which was similar to the mean SG elicited from their children of 0.92 +/- 0.10. The parent and child SG were moderately concordant (ICC=0.64, 95% CI=0.30, 0.83; P=.0005). In contrast, TTO scores were not concordant (ICC=0.14, 95% CI=-0.29, 0.53; P=.3), with parents (mean TTO=0.77 +/- 0.31) rating HRQL worse than children (mean TTO=0.92 +/- 0.11; P=.04). Similarly, the mean parent HUI2 of 0.82 +/- 0.22 was lower than the child HUI2 of 0.95 +/- 0.07; P=.02 and HUI2 were not concordant (ICC=0.11, 95% CI=-0.35, 0.53; P=.3) between parents and children. CONCLUSION: Parents and children rate HRQL similarly according to SG, but parents rate HRQL significantly worse using TTO and HUI2.

Adolescent↗
PubMed2004

Absence of impact of donor hepatic steatosis and posttransplantation lamivudine resistance in a patient with chronic hepatitis B.

A patient with chronic hepatitis B underwent liver transplantation for end-stage cirrhosis. The donor liver graft had moderate steatosis and fibrosis. He was placed on lamivudine for hepatitis B prophylaxis but developed viral relapse due to emergence of a lamivudine-resistant mutant at week 72 posttransplantation. Results of liver biochemistry were normal liver histology revealed minimal steatosis and inflammation at weeks 151 and 128, respectively. This report illustrates that the use of a steatotic donor liver and the emergence of lamivudine resistance posttransplantation are not necessarily associated with significant graft damage. A marginal donor graft can be considered due to the donor shortage. Lamivudine monoprophylaxis for hepatitis B virus-related liver diseases post liver transplantation can be used in areas where hepatitis B immunoglobulin is not affordable.

Drug Resistance↗
PubMed2004

Active versus passive cooling during work in warm environments while wearing firefighting protective clothing.

This study examined whether active or passive cooling during intermittent work reduced the heat strain associated with wearing firefighting protective clothing (FPC) and self-contained breathing apparatus (SCBA) in the heat (35 degrees Celsius, 50% relative humidity). Fifteen male Toronto firefighters participated in the heat-stress trials. Subjects walked at 4.5 km.h(-1) with 0% elevation on an intermittent work (50 min) and rest (30 min) schedule. Work continued until rectal temperature (T(re)) reached 39.5 degrees Celsius, or heart rate (HR) reached 95% of maximum or exhaustion. One of three cooling strategies, forearm submersion (FS), mister (M), and passive cooling (PC) were employed during the rest phases. Tolerance time (TT) and total work time (WT) (min) were significantly increased during FS (178.7 +/- 13.0 and 124.7 +/- 7.94, respectively) and M (139.1 +/- 8.28 and 95.1 +/- 4.96, respectively), compared with PC (108.0 +/- 3.59 and 78.0 +/- 3.59). Furthermore, TT and WT were significantly greater in FS compared with M. Rates of T(re) increase, HR and T-(sk) were significantly lower during active compared with passive cooling. In addition, HR and T(re) values in FS were significantly lower compared with M after the first rest phase. During the first rest phase, T(re) dropped significantly during FS (approximately 0.4 degree Celsius) compared with M (approximately 0.08 degree Celsius) while PC increased (approximately 0.2 degree Celsius). By the end of the second rest period T(re) was 0.9 degree Celsius lower in FS compared with M. The current findings suggest that there is a definite advantage when utilizing forearm submersion compared with other methods of active or passive cooling while wearing FPC and SCBA in the heat.

Adult↗
PubMed2004

Paradoxical roles of different nitric oxide synthase isoforms in colonic injury.

Nitric oxide (NO) is a free radical that is largely produced by three isoforms of NO synthase (NOS): neuronal (nNOS), endothelial (eNOS), and inducible (iNOS). NO regulates numerous processes in the gastrointestinal tract; however, the overall role that NO plays in intestinal inflammation is unclear. NO is upregulated in both ulcerative colitis and Crohn's disease as well as in animal models of colitis. There have been conflicting reports on whether NO protects or exacerbates injury in colitis or is simply a marker of inflammation. To determine whether the site, timing, and level of NO production modulate the effect on the inflammatory responses, the dextran sodium sulfate model of colitis was assessed in murine lines rendered deficient in iNOS, nNOS, eNOS, or e/nNOS by targeted gene disruption. The loss of nNOS resulted in more severe disease and increased mortality, whereas the loss of eNOS or iNOS was protective. Furthermore, concomitant loss of eNOS reversed the susceptibility found in nNOS-/- mice. Deficiencies in specific NOS isoforms led to distinctive alterations of inflammatory responses, including changes in leukocyte recruitment and alterations in colonic lymphocyte populations. The present studies indicate that NO produced by individual NOS isoforms plays different roles in modulating an inflammatory process.

Animals↗
PubMed2003

The burden of illness of gastro-oesophageal reflux disease: impact on work productivity.

BACKGROUND: The impact of gastro-oesophageal reflux disease on work productivity has become increasingly important, as the symptoms of gastro-oesophageal reflux disease affect individuals in their productive years of life. AIMS: To assess the impact of gastro-oesophageal reflux disease on reduced work productivity and to identify the predictors of reduced productivity. METHODS: A sample of employed individuals reporting chronic heartburn was selected from US household mail survey respondents. Heartburn severity and frequency were recorded using a diary, and work productivity was assessed using the Work Productivity and Activity Impairment Questionnaire for Patients with Symptoms of Gastro-oesophageal Reflux Disease. Predictors of reduced productivity were evaluated. RESULTS: Over 30% of heartburn sufferers reported reduced productivity. Individuals with symptoms of gastro-oesophageal reflux disease (n = 1003) reported 6.0% reduced productivity attributable to symptoms. Over 48% of respondents with severe symptoms reported reduced productivity, compared with 40% and 12% of respondents with moderate and mild symptoms, respectively. Using logistic regression, severity, a younger age and nocturnal symptoms were associated with increased odds of reduced productivity. In those reporting nocturnal heartburn, medication use and sleep interference increased the odds of reduced productivity. CONCLUSIONS: Reduced work productivity is seen in a large proportion of subjects on prescription medication for gastro-oesophageal reflux disease. Symptom severity and nocturnal heartburn are significantly associated with reduced work productivity, particularly when nocturnal heartburn interferes with sleep.

Adult↗
PubMed2003

Construct validation of the Health Utilities Index and the Child Health Questionnaire in children undergoing cancer chemotherapy.

The objective of this study was to evaluate the construct validity of two questionnaire-based measures of health-related quality of life (HRQL) in children undergoing cancer chemotherapy: the Health Utilities Index (HUI) and the Child Health Questionnaire (CHQ). Subjects were children hospitalised for chemotherapy. To examine construct validity: (1). a priori expected relations between CHQ concepts and HUI attributes were examined; (2). HUI and CHQ summary scores were compared to visual analogue scale (VAS) scores. Ease of completion was rated using a 5-point categorical scale and completion time was recorded. A total of 36 subjects were included. The maximum score was seen in 15 (47%) of HUI3 assessments. As predicted, CHQ body pain was moderately correlated with HUI3 pain (r=0.51), CHQ physical functioning was moderately correlated with HUI2 mobility (r=0.58) and CHQ mental health was moderately correlated with HUI2 emotion (r=0.53). Only the CHQ psychosocial subscale (and not HUI) was correlated with VAS (r=0.44). The CHQ and the HUI were both easy to use. The HUI questionnaires required less time to complete (mean=3.1, s.d.=1 min) compared with CHQ (mean=13.1, s.d.=3.4 min, P<0.0001). In conclusion, HUI and CHQ demonstrated construct validity in children undergoing cancer chemotherapy. The Health Utilities Index is subject to a ceiling effect whereas CHQ requires more time to complete.

Adolescent↗
PubMed2003

Risk factors for perioperative morbidity and mortality after extended hepatectomy for hepatocellular carcinoma.

BACKGROUND: Extended hepatectomy with resection of more than four segments is a high-risk operation, especially in patients with hepatocellular carcinoma (HCC) associated with chronic liver disease. This study evaluated the risk factors for morbidity and mortality following extended hepatectomy for HCC. METHODS: Preoperative and intraoperative variables of 155 patients who underwent extended hepatectomy for HCC were analysed to identify risk factors for postoperative morbidity and mortality. RESULTS: The overall morbidity rate was 55.5 per cent (n = 86). Most morbidity was due to ascites or pleural effusion. Significant life-threatening complications occurred in 20.0 per cent (n = 31). The perioperative mortality rate was 8.4 per cent (n = 13). Multivariate analysis found that portal clamping (P = 0.023) and perioperative blood transfusion (P < 0.001) were risk factors for morbidity, whereas perioperative blood transfusion (P < 0.001) was the only risk factor for significant morbidity. Co-morbid illness (P = 0.019) and perioperative blood transfusion (P = 0.004) were risk factors for perioperative mortality. CONCLUSION: Meticulous operative techniques to minimize blood loss and transfusion, while avoiding a prolonged Pringle manoeuvre, may help reduce postoperative morbidity. Avoidance of perioperative blood transfusion and careful preoperative selection of patients in terms of overall physiological status are important measures to reduce the postoperative mortality rate.

Adolescent↗
PubMed2003

Right lobe living donor liver transplantation with or without venovenous bypass.

BACKGROUND: Venovenous bypass was considered necessary to maintain haemodynamic stability and avoid splanchnic and retroperitoneal congestion during the anhepatic phase of liver transplantation. It was essential for right lobe living donor liver transplantation (LDLT) in which the inferior vena cava needed to be cross-clamped to construct wide and short hepatic vein anastomoses. However, many complications related to venovenous bypass have been reported. This study aimed to determine whether venovenous bypass was necessary for right lobe LDLT. METHODS: Between June 1996 and June 2001, 72 patients underwent right lobe LDLT. The outcomes for the first 29 patients who had venovenous bypass during the operation were compared with those of the remaining 43 patients who did not have venovenous bypass. In patients without bypass, blood pressure was maintained during the anhepatic phase by boluses of fluid infusion and vasopressors. RESULTS: Compared with patients undergoing operation without venovenous bypass, patients who had venovenous bypass required significantly more blood, fresh frozen plasma and platelet infusion, and had a lower body temperature; their postoperative hepatic and renal function in the first week was worse than that in patients who did not have a bypass. The time to tracheal extubation was longer and the incidence of reintubation for ventilatory support was higher with venovenous bypass. Six of the 29 patients with venovenous bypass died in hospital, compared with two of the 43 patients without a bypass (P = 0.05). By multivariate analysis, the lowest body temperature during the transplant operation was the most significant factor that determined hospital death. CONCLUSION: Venovenous bypass is not necessary and is probably harmful to patients undergoing right lobe LDLT, and should therefore be avoided.

Adolescent↗
PubMed2003

Effects of the intermittent Pringle manoeuvre on hepatic gene expression and ultrastructure in a randomized clinical study.

BACKGROUND: The intermittent Pringle manoeuvre during hepatectomy results in a better clinical outcome when the accumulated ischaemia time is less than 120 min. The aim of this study was to investigate hepatic gene expression related to microcirculatory modulation and ultrastructural changes in patients having the intermittent Pringle manoeuvre. METHODS: Forty patients who underwent hepatectomy for liver tumours were randomly assigned to liver transection with intermittent Pringle manoeuvre (Pringle group, n = 20) or without the manoeuvre (control group, n = 20). The clinical data and hepatic expression of endothelin (ET) 1 and endothelial nitric oxide synthase (eNOS) combined with liver ultrastructure were compared. RESULTS: The Pringle manoeuvre resulted in less blood loss (8.9 versus 12.4 ml/cm(2); P = 0.034), a shorter transection time (2.7 versus 4.1 min/cm(2); P = 0.015) and a lower serum bilirubin level on postoperative day 2 (26 versus 35 microm/l; P = 0.04). The hepatic messenger RNA content of ET-1 decreased by 38 per cent of the basal level in the Pringle group, whereas it increased by 28 per cent in the control group (P = 0.026). More patients in the control group showed swelling of mitochondria in hepatocytes and disruption of sinusoidal lining cells (12 of 20 patients versus three of 20 in the Pringle group; P = 0.008). CONCLUSION: The intermittent Pringle manoeuvre results in less disturbance of the hepatic microcirculation and better preservation of liver sinusoids after hepatectomy.

Adult↗
PubMed2003

Objective assessment of technical skills of surgical trainees in Hong Kong.

BACKGROUND: The need for assessment of technical skills is well recognized and objective methods of assessment are currently under investigation in the UK. The applicability of these assessment tools to trainees with a different training background in another country was examined. METHODS: Six bench-top models for basic surgical trainees (BSTs) and eight for higher surgical trainees (HSTs) (five in common) were assessed for construct validity in 70 subjects. Objective assessment methods included motion analysis using the Imperial College Surgical Assessment Device, Objective Structured Assessment of Technical Skills and Minimally Invasive Surgical Trainer in Virtual Reality. RESULTS: All models shared between BSTs and HSTs exhibited construct validity (range P = 0.050 to P < 0.001). Of the three modules for HSTs alone, only one gave significant results (small bowel anastomosis; P = 0.005). Reasons for this were sought. CONCLUSION: The methods of objective technical skills assessment of trainees in the UK are applicable to those in Hong Kong. Their use should be promoted and the tracking of skills development encouraged.

Adult↗
PubMed2003

Interaction between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA).

In this paper we describe the in vitro interaction between three strains of methicillin-sensitive Staphylococcus aureus (MSSA) [NCTC 11561 and two strains derived from patients (PMSSA)] and endemic methicillin-resistant Staphylococcus aureus (EMRSA) 1, 3, 15 and 16. Mixed bacterial cultures of MSSA and EMRSA were incubated and subcultured after one, two and seven days. A proportion of MRSA in 50 randomly selected colonies was assessed. All strains of EMRSA (EMRSA 1, 3, 15 and 16) outgrew and virtually eradicated MSSA (NCTC 11561) after 24 h. The interaction between strains of PMSSA and the various strains of EMRSA was variable. PMSSA strain 1 was almost completely outgrown by EMRSA 1 and EMRSA 3 after seven days. Similarly there was a substantial increase of EMRSA 1 and 3 when tested against PMSSA strain 2. EMRSA 15 increased modestly against both strains, but EMRSA 16 failed to increase in proportion against either of the strains. We conclude that there is a complex interaction between various strains of EMRSA and MSSA. This interaction may have an important bearing on colonization of patients with MRSA.

Antibiosis↗