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Biomedical subjects

J Wong

Publications and source records attributed to J Wong.

At least 181 records · Page 10Linked to original sources
PubMed2000

Intraoperative vs postoperative morphine improves analgesia without increasing PONV on emergence from ambulatory surgery.

PURPOSE: To compare the timing of administration of morphine in patients undergoing painful ambulatory surgical procedures to determine whether there was a difference in postoperative nausea or vomiting (PONV), quality of analgesia, and recovery profile. METHODS: In a double-blinded, placebo-controlled, prospective study, 70 ASA I-II patients were randomized to receive 0.1 mg x kg(-1) morphine intraoperatively (lop) (n=35), or postoperatively (Pop) (n=35). The severity of nausea and pain were measured using visual analog scales (VAS). RESULTS: There was no difference between the groups in postoperative nausea scores or the incidence of PONV. Upon awakening, patients who received Pop morphine had higher pain VAS scores with movement (7.6 +/- 2 vs 5.4 +/- 3, P < 0.003) and at rest (6.9 +/- 3 vs 5.1 +/- 3, P < 0.013) than the lop morphine group. The total number of PCA attempts and analgesic requirements were similar. Patients who received Pop morphine were able to drink sooner than the lop group (90 +/- 34 vs 111 +/- 38 min, P < 0.05). All other recovery milestones were similar. Times to discharge from hospital were similar. CONCLUSIONS: Administration of 0.1 mg x kg(-1) morphine iv intraoperatively improves postoperative analgesia upon emergence from painful ambulatory surgical procedures without increasing the incidence of PONV There was no increase in PONV when morphine was administered intraoperatively rather than postoperatively.

Adolescent↗
PubMed2000

Effects of the aromatase inhibitor anastrozole on serum oestrogens in Japanese and Caucasian women.

PURPOSE: Substantial differences in plasma oestrogen disposition have been reported between Japanese and Caucasian women, but there are currently few data available on the relative endocrinological effects of aromatase inhibitors in these two groups. Hence, the effects of the nonsteroidal aromatase inhibitor anastrozole on serum oestrogen concentrations were compared in 24 healthy postmenopausal Japanese women and 24 healthy postmenopausal Caucasian women. METHODS: Anastrozole, 1 mg/day, was given once daily for 16 days. Serum oestradiol and oestrone sulphate levels were measured on three consecutive days beginning 2 days before the first dose, and on a further three consecutive days beginning on the penultimate day of dosing. Trough concentrations of anastrozole (measured 24 h after dosing) were also determined during the same periods. RESULTS: There were no substantial differences in plasma oestrogen concentrations between the Japanese and Caucasian women at baseline. On average, anastrozole suppressed serum oestradiol and oestrone sulphate levels by approximately 87% and 93%, respectively, for both Japanese and Caucasian women, and minimum plasma anastrozole concentrations at steady-state (anastrozole C(min)) were also similar in both groups. Statistical analysis of serum oestradiol and serum oestrone sulphate levels, and plasma anastrozole C(min) showed that there were no statistically significant differences between the Japanese and Caucasian women. CONCLUSION: Neither the pharmacodynamic effects of anastrozole on serum oestrogens nor the pharmacokinetics of anastrozole differ between postmenopausal Japanese and Caucasian women. Hence, these findings suggest that the therapeutic benefits of anastrozole in Caucasians will be predictive of the drug's effect in Japanese women and support the use of anastrozole in postmenopausal Japanese women with breast cancer.

Aged↗
PubMed2000

Determining resectability for hepatocellular carcinoma: the role of laparoscopy and laparoscopic ultrasonography.

We reviewed our experience with preoperative determination of resectability in patients with hepatocel-lular carcinoma (HCC) over the last 10 years, and evaluated the role of laparoscopy with laparoscopic ultrasonography (USG) since we instituted this technique in June 1994. From January 1989 to December 1998, 500 of 1741 patients with HCC (28.7%) were considered suitable for hepatic resection after preoperative assessment. Significantly more contrast-enhanced computed tomography (CT) scans and fewer percutaneous USGs or hepatic arteriograms were performed in the 299 patients managed since June 1994 (group 2) than in the 201 patients managed before then (group 1). One hundred and ninety-eight patients in group 2 (66%) underwent laparoscopy with laparoscopic USG. Unresectable disease was found in 41 patients in group 1 (20.4%) (all at laparotomy), and in 68 patients in group 2 (22.7%) (16 at laparotomy without laparoscopic examination, 31 at laparoscopic examination alone, and 21 at laparotomy after an inconclusive laparoscopic examination) (P = 0.5). The most common features of unresectable disease were the presence of bilobar intrahepatic metastases and an inadequate liver remnant with cirrhosis. The adoption of the laparoscopic examination after June 1994 improved the overall resection rate at laparotomy in group 2 from 77.3% to 86. 2%, which was better than that in group 1 (79.6%, P = 0.057). For patients with unresectable disease, the operation time and hospital stay were significantly shorter in group 2. The postoperative morbidity and mortality rates were 9.8% and 4.9%, respectively, in group 1, and 5.9% and 2.9% in group 2. There was no operative morbidity in the 31 patients who had unresectable disease detected by the laparoscopic examination alone. Laparoscopy with laparoscopic USG avoids unnecessary laparotomy, and has a definite role in determining resectability in patients with HCC.

Adolescent↗
PubMed2000

Survival in patients with chronic lower extremity ischemia: a risk factor analysis.

This is a prospective cohort comparison study aiming to determine the mortality of patients with peripheral arterial occlusive disease (PAOD) and identify the risk factors affecting their survival. Data regarding demographic and biochemical risk factors, and lower limb disease severity classified by vascular laboratory criteria were collected prospectively from 665 consecutive patients presenting with symptoms of peripheral arterial occlusive disease. The effect of patient and disease risk factors on survival was analyzed by the life-table method and independent significant variables examined by a multivariate Cox regression model. The cumulative survival for all patients at 1, 3, and 5 years were 86.1, 71.2, and 55.8%, respectively, with a median survival of 72.2 months. Female sex, age, smoking, heart disease, renal disease, respiratory disease, stroke, critical ischemia, lowest anklebrachial index, no vascular reconstruction, and major amputation were associated with higher mortality. Lipid and biochemical variables were not significant determinants. Using multivariate Cox regression, age (>70), disease severity, anklebrachial index (<0.5), no vascular reconstruction, diabetes mellitus, and renal and cardiorespiratory diseases were identified as independent risk factors affecting patient survival. The survival of patients with PAOD is poor compared with the general population. Significant patient-related variables were largely coexisting diseases and advanced age, whereas the other risk factors for atherosclerosis are less influential. Disease severity may bear a direct relationship to mortality, and patients with critical ischemia have the worst prognosis. Early disease detection and timely vascular reconstruction may lead to an improvement in overall survival.

Adult↗
PubMed2000

alpha-synuclein promotes mitochondrial deficit and oxidative stress.

Abnormal accumulation of the presynaptic protein alpha-synuclein has recently been implicated in the pathogenesis of Alzheimer's and Parkinson's diseases. Because neurodegeneration in these conditions might be associated with mitochondrial dysfunction and oxidative stress, the effects of alpha-synuclein were investigated in a hypothalamic neuronal cell line (GT1-7). alpha-Synuclein overexpression in these cells resulted in formation of alpha-synuclein-immunopositive inclusion-like structures and mitochondrial alterations accompanied by increased levels of free radicals and decreased secretion of gonadotropin-releasing hormone. These alterations were ameliorated by pretreatment with anti-oxidants such as vitamin E. Taken together these results suggest that abnormal accumulation of alpha-synuclein could lead to mitochondrial alterations that may result in oxidative stress and, eventually, cell death.

Animals↗
PubMed2000

Thoracoscopic esophageal mobilization for pharyngolaryngoesophagectomy.

BACKGROUND: Pharyngolaryngoesophagectomy (PLE) for hypopharyngeal cancers and tumors of the cervical esophagus is a procedure of significant morbidity and mortality. Conventional esophageal mobilization is performed with the transhiatal dissection technique. Thoracoscopic esophageal mobilization is tested as an alternative to determine whether surgical outcome can be improved. METHODS: From 1994 to 1998, thoracoscopic mobilization was carried out in 30 consecutive patients who underwent PLE (PLE-TS). This was compared to a historical cohort of 30 patients who had PLE with transhiatal mobilization (PLE-TH). RESULTS: In PLE-TS, thoracoscopic esophageal mobilization was successful in 28 patients (93%). Median blood loss was 700 mL (range, 164 to 3,000 mL) compared to 1,000 mL (range, 400 to 2,200 mL) in group PLE-TH, p = 0.21. Thoracoscopy time was 90 minutes (range, 60 to 180 minutes). Total operating time were 392 minutes (range, 180 to 570 minutes) and 300 minutes (range, 150 to 550 minutes) in PLE-TS and PLE-TH, respectively (p = 0.03). Major pulmonary complications occurred in 7 (23%) and 8 (27%) patients in PLE-TS and PLE-TH, respectively (p = 0.77). Cardiac complications occurred in 7 (23%) and 5 (17%) patients in PLE-TS and PLE-TH, respectively (p = 0.52). Thirty-day mortality rates were 3.3% and 10% (p = 0.6) and hospital mortality rates were 13% and 17%, (p = 1.0). CONCLUSIONS: Thoracoscopy was safe and feasible. Morbidity and mortality after PLE was not significantly reduced. The theoretical advantage offered by thoracoscopy may be offset by the lengthened time of one-lung anesthesia.

Adult↗
PubMed2000

Unusual immunogammopathy maculopathy.

PURPOSE: To describe an unusual maculopathy in patients with serum immunogammopathies. DESIGN: Retrospective observational small case series. PARTICIPANTS: Three patients derived from the clinical retina practices of the authors were noted to have unusual maculopathy. METHODS: Each patient underwent fluorescein angiography and serum laboratory evaluation. MAIN OUTCOME MEASURE: Findings on fluorescein angiography. RESULTS: An unusual and atypical macular detachment with or without subretinal precipitates or fundus signs of serum hyperviscosity, such as retinal hemorrhages and dilated retinal veins, may be observed in patients with immunogammopathies such as multiple myeloma, Waldenström's macroglobulinemia, and benign polyclonal gammopathy. Fluorescein angiography shows macular hypofluorescence with no evidence of retinal vascular or retinal pigment epithelial leakage within the macular elevation. CONCLUSIONS: Patients with atypical unilateral or bilateral macular detachment may be afflicted with a serum immunogammopathy such as multiple myeloma or Waldenström's macroglobulinemia. Diagnostic serum protein electrophoresis and hematology consultation should be considered.

Aged↗
PubMed2000

Ten-fold augmentation of endothelial uptake of vascular endothelial growth factor with ultrasound after systemic administration.

OBJECTIVES: In this study, the feasibility of delivering and enhancing the uptake of vascular endothelial growth factor (VEGF) into the intact endothelium by using ultrasound (US) facilitation was determined. BACKGROUND: A limitation of tissue-targeted drug delivery is the need for direct arterial cannulation. We postulate a mechanism by which agents injected intravenously may be targeted to a tissue using US and ultrasonic contrast agents. METHODS: We used a rat model to test the ability of US and an ultrasonic contrast agent perflurocarbon exposed sonicated dextrose albumin (PESDA) to increase uptake of VEGF in the myocardium. Continuous wave Doppler US (0.6 W/cm2 at 1 MHz for 15 min) was applied to the chest wall overlying the myocardium during intravenous injection with either VEGF (100 microg/kg) alone or a combination of VEGF and PESDA (0.1%). Control rats had VEGF infused without US or PESDA. The VEGF uptake was measured quantitatively in the heart, lung, liver and kidneys by enzyme-linked immunosorbent assay (ng/g of tissue) and morphologically by fluorescence microscopy. RESULTS: There was an eight-fold increase in VEGF uptake in the heart by US alone (16.86 +/- 1.56 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) and a 13-fold increase with US + PESDA (26.78 +/- 2.88 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) compared with control rats. Fluorescence microscopy revealed deposition of VEGF in the endothelium of small intramyocardial arterioles. CONCLUSIONS: These results show a marked increase in endothelial VEGF uptake with US and US + PESDA. Thus, US may be used to augment endothelial VEGF uptake 10-fold to 13-fold.

Animals↗
PubMed2000

Results of partial left ventriculectomy for dilated cardiomyopathy: hemodynamic, clinical and echocardiographic observations.

OBJECTIVES: The study was done to prospectively measure the echocardiographic, hemodynamic and clinical outcomes after partial left ventriculectomy (PLV). BACKGROUND: Although PLV can improve symptoms of advanced heart failure, immediate postoperative echocardiographic findings remain abnormal. METHODS: Fifty-nine patients with cardiomyopathy and advanced heart failure underwent PLV and concomitant mitral valve surgery between May 1996 and December 1997. Thirty-nine percent were on inotropic therapy. All were New York Heart Association (NYHA) functional class III or IV. Mechanical circulatory support (LVAD) and transplant were provided for rescue therapy when hemodynamic compromise occurred. Patients were followed for a mean of 405+/-168 days, and clinical, echocardiographic and hemodynamic measures were obtained preoperatively, immediately postoperatively, and at 3 and 12 months prospectively. RESULTS: Comparing preoperative and 12-month postoperative values in event-free survivors, we found: NYHA functional class improved from 3.6 to 2.1, p < 0.0001; peak oxygen consumption increased from 10.8 to 16.0 ml/kg/min, p < 0.0001; LV ejection fraction increased from 13+/-6.0% to 24+/-6.9%, p < 0.0001; LV end diastolic diameter decreased from 8.2+/-1.03 to 6.2+/-0.64 cm, p < 0.0001, and volume was reduced from 167+/-60 to 105+/-38 ml/m2, p = 0.02. Central hemodynamics did not normalize after surgery. CONCLUSIONS: Partial left ventriculectomy can provide structural remodeling of the heart that may result in temporary improvement in clinical compensation. However, perioperative failures and the return of heart failure limit the propriety of this procedure.

Aged↗
PubMed2000

Pyloroplasty in gastric replacement of the esophagus after esophagectomy: one-layer or two-layer technique?

Pyloroplasty is our routine drainage procedure performed when the stomach is used as the esophageal substitute after esophageal resection for cancer. The technique of pyloroplasty varies among surgeons and effectiveness has not been studied. Thirty-four patients with a gastric conduit whose pyloroplasty was constructed with a one-layer technique (group 1) were compared with a historical cohort of 31 patients treated with a two-layer method (group 2). Patients who had an abnormal pyloroduodenal region were excluded from the study. Perioperative morbidity and post-operative gastrointestinal symptoms within the first 6 months were evaluated. Patient demographics and the types of surgical procedures did not differ between the two groups. The median daily output from the nasogastric tube was 119 mL in group 1 and 115 mL in group 2 (p = 0.49). In 40 out of 65 patients (62%), the nasogastric tube was removed at a median of 3 days after the operation in both groups. There was no leakage from the pylorus or the esophagogastric anastomosis in this study. In both groups, the patients could resume a semisolid diet at a median of 8 days after surgery. One patient in group 1 and two patients in group 2 developed gastroparesis clinically. No patient, however, required reoperation. There was no significant difference in cardiopulmonary complications attributable to the technique of pyloroplasty. The incidence of gastrointestinal symptoms within the first 6 months after surgery did not differ. Regurgitation was the most common symptom, affecting 10 patients in each group, 29% and 32% in group 1 and group 2 respectively (p = 1.0). Pyloroplasty was an effective gastric drainage procedure after esophagectomy whether the one or two-layer method was used. The authors prefer the one-layer method, which is safe and simple.

Anastomosis, Surgical↗