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R C Wong

Publications and source records attributed to R C Wong.

At least 37 records · Page 2Linked to original sources
PubMed1999

Diagnostic value of classical and atypical antineutrophil cytoplasmic antibody (ANCA) immunofluorescence patterns.

BACKGROUND: The "classical" antineutrophil cytoplasmic antibody (C-ANCA) pattern seen on indirect immunofluorescence (IIF) is characterised by granular cytoplasmic staining showing central or interlobular accentuation, and is strongly associated with antiproteinase-3 antibodies (PR3-ANCA) and Wegener's granulomatosis. However, many laboratories report C-ANCA in the presence of any cytoplasmic IIF staining, regardless of pattern, which risks reducing the diagnostic value of this pattern. AIMS: To classify different cytoplasmic ANCA patterns and thus determine whether stringent application of the classical criteria for C-ANCA would produce better correlation between C-ANCA and (1) PR3-ANCA enzyme linked immunosorbent assay (ELISA) results; (2) a diagnosis of systemic vasculitis (including Wegener's granulomatosis). METHODS: 72 sera with cytoplasmic IIF collected over a two year period were analysed by IIF and a commercial PR3-ANCA ELISA kit. RESULTS: Three IIF patterns were defined: "classical/true" C-ANCA as described above (n = 27 (37.5%)); "flat" ANCA with homogeneous cytoplasmic staining (n = 21 (29%)); and "atypical" ANCA which included all other cytoplasmic patterns (n = 24 (33.5%)). Twenty five of the 27 true C-ANCA sera (92.5%) contained PR3-ANCA (p < 0.0001), but none of the 21 with flat ANCA and only one of the 24 with atypical ANCA. From clinical data on 23 of the 27 true C-ANCA positive patients, 20 (87%) had evidence of Wegener's granulomatosis or systemic vasculitis (p < 0.0001 v the other two patterns). However, none of 19 sera with flat ANCA and clinical data had evidence of systemic vasculitis. CONCLUSIONS: Restricting the term "c-ANCA" to the "classical" description of central/interlobular accentuation on IIF, will improve its correlation with PR3-ANCA positivity and a diagnosis of systemic vasculitis.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1998

Role of endoscopic retrograde cholangiopancreatography for suspected choledocholithiasis in patients undergoing laparoscopic cholecystectomy.

BACKGROUND: We report our experience of selective cholangiography in a series of laparoscopic cholecystectomies and evaluate the strategy of using "stricter criteria" to select preoperative endoscopic retrograde cholangiopancreatography (ERCPs). METHODS: A total of 1847 consecutive laparoscopic cholecystectomies were analyzed for use of cholangiography. A high risk of common bile duct stones (bilirubin level more than 2 mg/dL, jaundice, alkaline phosphatase level more than 150 U/L, pancreatitis, or dilated bile duct and/or stone on ultrasound or CT) was an indication for preoperative ERCP. Selective intraoperative cholangiography was performed for intermediate risk of bile duct stones. The strategy of using "stricter criteria" (jaundice and/or demonstrated bile duct stones on ultrasound or CT) for selecting preoperative ERCP was evaluated retrospectively. RESULTS: Preoperative ERCP was performed in 135 patients (7.3%) and demonstrated bile duct stones in 43 (32%). Of 36 patients with mild gallstone pancreatitis alone, stones were found only in 6 patients (17%). Selective intraoperative cholangiography was performed in 87 (5%), and stones were found in 2 (2%); 67 (3.6%) postoperative ERCPs were performed for suspected choledocholithiasis, and stones were found in 21 (32%). Applying "stricter criteria" to select preoperative ERCP would predict ductal stones in 56%, whereas 3% of patients with stones would be missed, resulting in a 50% reduction in preoperative ERCPs. CONCLUSIONS: Even in selected patients considered likely to have choledocholithiasis, the diagnostic yield of preoperative ERCP is low. Using "stricter criteria" to select patients for preoperative ERCP can avoid unnecessary ERCPs.

Cholangiography↗
PubMed1998

Palliation of malignant gastric outlet obstruction using an endoscopically placed Wallstent.

BACKGROUND: Treatment options for malignant gastric outlet obstruction are limited. Surgical gastrojejunostomy, commonly performed, has significant morbidity and mortality. METHODS: Over 2 years, we prospectively studied the safety, feasibility, and outcomes for use of a newly designed expandable metal stent (Wallstent Enteral; Schneider, Minneapolis, Minn.) to treat malignant gastric outlet obstruction. Stents 16 to 22 mm in diameter and 60 to 90 mm in length were deployed directly through the endoscope. RESULTS: Twelve patients (ten women, two men; mean age 59.7 years) underwent stenting. Thereafter, six patients were able to eat a regular diet; three could eat pureed food. In three patients, the procedure was unsuccessful because of multiple obstructions not recognized before stenting (one) and stents deployed too proximally (one) or too distally (one). CONCLUSIONS: Placement of a newly designed stent through the endoscope is safe and effective palliation for various types of malignant gastric outlet obstruction and significantly improves many aspects of patient quality of life.

Duodenal Obstruction↗
PubMed1998

Management of occluded biliary Wallstents.

BACKGROUND: Wallstents (Schneider Stent, Inc., USA) used for the palliation of malignant biliary strictures, although associated with prolonged patency, can occlude. There is no consensus regarding the optimal management of Wallstent occlusion. AIMS: To evaluate the efficacy of different endoscopic methods for managing biliary Wallstent occlusion. METHODS: A multicentre retrospective study of patients managed for a biliary Wallstent occlusion. RESULTS: Data were available for 38 patients with 44 Wallstent occlusions, all of which had initial endoscopic management. Twenty four patients had died and 14 were alive after a median follow up of 231 (30-1095) days following Wallstent occlusion. Occlusions were managed by insertion of another Wallstent in 19, insertion of a plastic stent in 20, and mechanical cleaning in five. Endoscopic management was successful in 43 (98%). Following management of the occlusion, bilirubin decreased from 6.0 (0.5-34.3) to 2.1 (0.2-27.7) mg/100 ml (p < 0.05). No complications occurred. The median duration of second stent patency was 75 days (95% confidence interval 43 to 107) after insertion of another Wallstent, 90 days (71 to 109) after insertion of a plastic stent, and 34 days (30 to 38) after mechanical cleaning (NS). The respective median survivals were 70 days (22-118), 98 days (54-142), and 34 days (30-380) (NS). Incremental cost effective analysis showed that plastic stent insertion is the most cost effective option. CONCLUSION: Although all three methods are equally effective in managing an occluded Wallstent, the most cost effective method appears to be plastic stent insertion.

Cholestasis↗
PubMed1997

Role of costimulators in T cell differentiation: studies using antigen-presenting cells lacking expression of CD80 or CD86.

For T cells to be optimally activated, recognition of Ag/MHC complexes by the TCR must be accompanied by a second, costimulatory signal that can be provided efficiently by the related costimulatory molecules CD80 (B7-1) and CD86 (B7-2). Recently, CD80 and CD86 have been implicated as differential determinants of Th1- vs Th2-type cytokine profiles. However, this remains a controversial issue since conflicting results have been obtained in different experimental models both in vivo and in vitro. To investigate the role of CD80 and CD86 in Th subset differentiation, we have examined the cytokine profiles induced in TCR transgenic T cells stimulated by peptide in association with splenic APCs obtained from knockout mice that selectively lack expression of either the CD80 or the CD86 molecule. Our data suggest that CD86, and to a lesser extent CD80, can make significant contributions to the production of both IL-4 and IFN-gamma. However, neither molecule plays an obligatory role in priming for the production of either effector cytokine. Furthermore, CD80 and CD86 contribute to the magnitude of T cell activation, but do not appear to selectively regulate Th1 vs Th2 differentiation.

Amino Acid Sequence↗
PubMed1997

Therapeutic ERCP in outpatients.

BACKGROUND: We evaluated the safety of outpatient therapeutic ERCP since most complications are apparent within a few hours. METHODS: We reviewed 190 patients undergoing planned outpatient therapeutic ERCP from a cohort of 409 consecutive therapeutic ERCP procedures. Patients were selected for outpatient therapeutic ERCP based on relative good health and overnight accommodation near our institution. RESULTS: Outpatient therapeutic ERCPs included plastic biliary stent insertion (n = 71), biliary sphincterotomy (45), pancreatic stent insertion (28), Wallstent insertion (19), biliary balloon or catheter dilation (10), pancreatic balloon or catheter dilation (8), biliary stone extraction with prior sphincterotomy (7), pancreatic sphincterotomy (5), and duodenal ampullectomy (1). Admission was necessary in 31 (16%) because of complications in 22 (11.6%) and observation of post-ERCP symptoms in 9. Twenty-six (13%) of these patients were admitted directly from the endoscopy unit recovery room and 5 (3%) from home after a median interval of 24 hours following discharge (range 5 to 48 hours). Reasons for admission were pancreatitis in 17, hemorrhage in 3, cholangitis in 3, endoscopic but not clinical hemorrhage in 4, pain in 4, and vomiting in 1. Of the patients who were admitted from home, 3 had pancreatitis (following sphincterotomy in 1, pancreatic stenting in 1, pancreatic balloon dilation in 1) and 2 had hemorrhage (postsphincterotomy in 1 and ampullectomy in 1). In comparison, of the 219 consecutive inpatients undergoing therapeutic ERCP, 28 (13%) developed complications with 1 (0.4%) death. CONCLUSIONS: A policy of selective outpatient therapeutic ERCP, with admission reserved for those with established or suspected complication, appears to be safe and reduces health care costs.

Biliary Tract Diseases↗
PubMed1997

Portal hypertensive stomapathy: a newly described entity and its successful treatment by placement of a transjugular intrahepatic portosystemic shunt.

We report the case of a 68-yr-old woman who had previously undergone a total colectomy and ileostomy for Crohn's disease limited to the colon. She subsequently had recurrent episodes of severe stomal bleeding and was discovered to have micronodular cirrhosis. No definite stomal varices were seen by visual inspection, stomal endoscopy, stomal endosonography, or angiography. Nevertheless, multiple discrete, punctate bleeding pints were seen on the external mucosal surface of the stoma (not at the mucocutaneous junction). Despite undergoing numerous modes of treatment, the bleeding continued. The only successful and effective form of treatment was the placement of a transjugular intrahepatic portosystemic shunt.

Aged↗
PubMed1996

Utility of parameters measured during pneumatic dilation as predictors of successful dilation.

OBJECTIVES: The ability to immediately predict the long term outcome of a pneumatic dilation in achalasia has not been well studied. This study prospectively compared immediate postpneumatic dilation parameters with long term efficacy to determine if any factors predicted a favorable long term outcome. METHODS: Twenty-nine previously undilated achalasia patients underwent graduated pneumatic dilation with Hurst-Tucker dilators (diameters 2.7, 3.3, 3.7, and 4.1 cm). Dilations began with the smallest dilator followed by an observation period of at least 6 wk to determine clinical response. If no clinical improvement was noted, the next size dilator was used. Immediate postdilation parameters studies included: 1) severity of pain during dilation, 2) amount of blood on the dilator, 3) insufflation pressures during dilation, 4) esophageal emptying of gastrograffin (30 ml), and 5) esophageal emptying of barium sulfate (90 ml). RESULTS: None of the postdilation parameters studied predicted which patients would have good long term results. Pain during dilation increased with increasing dilator size. CONCLUSIONS: The degree of pain associated with a pneumatic dilation, the amount of blood noted on the dilator, the difference in pressure required to inflate the dilator at the beginning versus the end of dilation, and the amount of esophageal emptying immediately postdilation did not predict long term outcome.

Adult↗
PubMed1996

Toothpick ingestion as a cause of acute and chronic duodenal inflammation.

Toothpicks are a common cause of foreign body ingestion. We present two patients with duodenal inflammation secondary to toothpick ingestion. In the first patient, there was acute onset of severe abdominal pain, with findings on computed tomography consistent with marked duodenal inflammation. Endoscopy revealed a toothpick embedded in the wall of the duodenum with associated ulceration. In the second patient, 4 months of chronic abdominal pain was evaluated by upper endoscopy which revealed a toothpick embedded in a 1-cm ulcer found in the third portion of the duodenum. Both patients denied memory of ingestion of the toothpicks. Endoscopic removal of the toothpicks resulted in rapid relief of symptoms.

Abdominal Pain↗
PubMed1995

Differentiation and tolerance of CD4+ T lymphocytes.

The development of effector and memory populations of T lymphocytes is determined by antigen-induced growth and differentiation of naive T cells, and it is regulated by antigen-induced functional tolerance and cell death. CD4+ helper T lymphocytes that vary in their profiles of cytokine production and in effector functions also show distinct responses to antigens and co-stimulatory signals, and they differ in their sensitivity to tolerance induction. Thus, stimuli that trigger T cell growth and differentiation, as well as mechanisms that inhibit T cell expansion, determine both the magnitude and the nature of T cell-dependent immune responses to protein antigens.

Animals↗
PubMed1995

Feasibility and accuracy of a postcard diary system for tracking healthcare utilization of community-dwelling older persons.

OBJECTIVE: To test the feasibility of and to validate a self-report weekly postcard diary of health care utilization. DESIGN: Case-series and validation study. SETTING: Community-based sample of fee-for-service and health maintenance organization (HMO) patients. PARTICIPANTS: A convenience sample of 24 community-dwelling older persons who had failed a self-administered screen and were eligible for a study of outpatient comprehensive geriatric assessment consultation. MEASUREMENTS: Subjects completed and mailed in a weekly postcard diary documenting medical, counseling, or rehabilitation therapy visits. If a subject did not respond within 10 days after the end of the week, a telephone call was placed to gather the information. For a subset of 10 subjects who were HMO enrollees, all records were reviewed to determine accuracy of the postcard diaries. RESULTS: Of the 24 subjects enrolled, one HMO enrollee dropped out following hip surgery after 4 weeks of completing diaries. The remaining 23 subjects (96% of total entered) provided complete information for 12 weeks. Telephone follow-up to either obtain or clarify utilization information was required for 22% of subjects. For the subset of 10 HMO subjects, seven underreporting, two overreporting, and one incorrect day errors were detected-a total of 10 errors representing 9% of diaries and 1.3% of patient-days. Kappa as a measure of agreement between the two methods (self-report and chart review) was 0.82 (P < .0001). Compared with chart review, the diary report was 75.0% sensitive and 99.8% specific. Positive and negative predictive values were 91.3% and 99.2%, respectively. CONCLUSION: These findings suggest that a postcard diary system with telephone follow-up is both a feasible and reasonably accurate method of tracking health care utilization by community-dwelling older persons, although a small percentage will be unable to adhere to this method.

Aged↗
PubMed1993

Intrauterine infarction of a pulmonary segment in a full-term newborn. A case report.

Intrauterine pulmonary infarction is extremely rare. In a series of 775 stillborn and newborn infants, only a few cases of acute pulmonary infarction were reported. The authors present the findings from a full-term infant who died at 9 hours of age of a chronic pulmonary infarction. Several pathogenic mechanisms, including the entry of placental thromboplastin into the fetal circulation, are discussed.

Fatal Outcome↗
PubMed1993

Endoscopic band ligation of esophageal varices.

Endoscopic sclerotherapy of esophageal varices rapidly became the standard initial nonsurgical method for control of hemorrhage. Although in widespread use around the world, the technique is associated with a significant complication rate that excludes it as a potential method for primary prophylaxis. The sclerotherapy technique has been difficult to standardize between different endoscopists and centers, with consequent incongruities in trial results and morbidity. The introduction of endoscopic band ligation heralds the possibility of a simple, reproducible method for acute and chronic treatment of varices and the hope that prophylactic eradication, before the first life-threatening hemorrhage, can be achieved safely and effectively.

Adolescent↗