PubMed Health⌕ Search

Biomedical subjects

N Y Wong

Publications and source records attributed to N Y Wong.

8 recordsLinked to original sources
PubMed2005

A defunctioning ileostomy does not prevent clinical anastomotic leak after a low anterior resection: a prospective, comparative study.

PURPOSE: Defunctioning ileostomy or colostomy is still routinely performed after low anterior resection in the belief that diverting the fecal stream will prevent anastomotic dehiscence. However, an ileostomy is not without morbidity for the patient. This study aims to determine if a diverting stoma is really necessary after a low anastomosis. METHODS: All low or ultralow anterior resections done in this department were performed by consultant-grade surgeons in a standardized manner. The patients were all monitored closely after surgery for clinical signs of an anastomotic leak. There were 1078 patients who underwent elective low or ultralow anterior resections in a ten-year period between 1994 and 2004. Twelve of them were irradiated before surgery; they were excluded from the study. During a seven-month period from February 2004 through August 2004, 324 patients who underwent such procedures were not defunctioned. These were compared with 742 patients who were previously defunctioned with a proximal stoma. The results were analyzed using the Pearson chi-squared test. RESULTS: Thirteen (4 percent) patients who were not defunctioned developed a clinical anastomotic leak, whereas the leak rate for those who were defunctioned was 3.8 percent. There was no statistical difference demonstrated. Ninety-five percent of patients who developed a leak required surgical intervention; the remaining 5 percent could be dealt with by radiologic drainage. The overall mortality rate for anastomotic leak in this department is 7.3 percent. CONCLUSION: A diverting stoma does not reduce postoperative anastomotic leak rate. Rather, it reduces the otherwise catastrophic effects of an anastomotic leak such as fecal peritonitis and septicemia. An ileostomy carries certain morbidity and also adds to the cost of the entire operation. Therefore, it should not be performed routinely. Instead, it should be performed selectively in patients with poorly prepared bowels, coupled with a distal limb washout, and in patients with significant comorbidities who can ill afford the complications of a leak.

Adult↗
PubMed2002

Adults in a high-risk area are unaware of the importance of colorectal cancer: a telephone and mail survey.

PURPOSE: There are few studies assessing public awareness of colorectal cancer even in developed countries. This questionnaire and telephone-based survey aimed to determine the degree of awareness of colorectal cancer among adults in a high-risk population with a high level of literacy. METHODS: Two thousand randomly-selected adults living in Singapore were invited to answer a questionnaire by telephone (T, n = 1,000) or by returned mail (M, n = 1,000). The questionnaire consisted of 20 questions relating to epidemiology, presentation, screening, and management of colorectal cancer. RESULTS: There was a compliance rate of 85.2 percent for telephoned subjects, but only 21.5 percent of mailed subjects returned a completed questionnaire. Only 2.7 percent of T and 1.4 percent of M named colorectal cancer as a fatal disease. Only 49.6 percent of T and 60.9 percent of M were aware that the colon and rectum are part of the intestines. A minority (T 11.7 percent, M 35.8 percent) were aware of screening as an important means against developing colorectal cancer. A large proportion (T 46.5 percent, M 34.9 percent) were unable to name even one symptom of colorectal cancer. There was low awareness of causative factors for colorectal cancer (T 39.6 percent, M 28.4 percent). A proportion (T 24.8 percent, M 28.4 percent) believed that colorectal cancer affects people less than 40 years of age. Newspapers and popular magazines exert far more influence (T 58.2 percent, M 52.1 percent) than television, the internet. or doctors in educating the public about colorectal cancer. Respondents with higher education level (junior college and above), as well as those with a positive family history, tend to score better in the knowledge section. CONCLUSIONS: Knowledge of colorectal cancer among the surveyed population was poor despite a relatively high incidence of the disease in Singapore. Public education regarding colorectal cancer is best done via newspapers and magazines.

Adolescent↗
PubMed1995

Determination of a novel cognitive enhancer, X9121, and its mono N-oxide metabolite, XG696, in dog plasma by reversed-phase high-performance liquid chromatography with ultraviolet detection.

A selective and sensitive high-performance liquid chromatographic assay for a novel cognitive enhancer, X9121 (I), and its mono N-oxide metabolite, XG696 (II), in dog plasma has been developed. Compounds I, II and internal standard (I.S.) were first extracted from dog plasma using a solid-phase Bond Elut Certify I 10-ml LRC reservoir extraction cartridge. Chromatographic separation of I, II and I.S. was conducted on a reversed-phase Zorbax Stable Bond cyano column. Ammonium acetate buffer (0.05 M, pH 6)-acetonitrile-triethylamine (75:25:0.1, v/v) was used as the mobile phase. Detection of all three compounds was by UV light absorbance at 313 nm. Using 0.5 ml of dog plasma for extraction, the minimum quantifiable limit was 10 ng/ml and the assay was linear from 10 to 5400 ng/ml. The coefficients of variation for intra-day precision ranged from 2.2 to 8.5% for I and from 2.5 to 9.8% for II. The coefficients of variation for the inter-day precision for these two compounds ranged from 2.6 to 9.0% and from 3.6 to 16.2%, respectively. The absolute percent differences for the accuracy results were within 11.0% of the spiked concentrations. Compounds I and II were stable in frozen plasma at -20 degrees C for at least 67 days.

Animals↗
PubMed1994

Determination of a novel sigma receptor antagonist, DuP 734, in rat plasma by reversed-phase high-performance liquid chromatography with ultraviolet detection.

A selective high-performance liquid chromatographic (HPLC) assay for a sigma receptor antagonist, DuP 734 (I), in rat plasma has been developed. Compound I and internal standard, XC031 (I.S.), were first extracted from plasma into an ethyl acetate-toluene mixture (3:7, v/v) and then back-extracted into freshly prepared phosphoric acid (0.03 M). Separation of I and I.S. with no interference from endogenous substances was achieved on a reversed-phase octyl column and detection was by UV at 229 nm. The mobile phase consisted of acetonitrile-glacial acetic acid-triethylamine-0.05 M ammonium acetate (670:4:2:2000, v/v). Using 0.5 ml of rat plasma for extraction, the limit of quantitation was 43 ng/ml and the assay was linear from 43 to 8536 ng/ml. The intra- and inter-day coefficients of variation ranged from 0.7 to 3.0%, and from 1.4 to 14.5%, respectively, over the entire concentration range. The accuracy was within 16.1% of the spiked concentrations. I was stable in frozen plasma at -20 degrees C for at least 68 days.

Animals↗
PubMedDate not supplied

Composite cure and shrinkage associated with high intensity curing light.

This study investigated the effectiveness of cure and post-gel shrinkage of three visible light-cured composite resins (In Ten-S [IT], Ivoclar Vivadent; Z100 [ZO], 3M-ESPE; Tetric Ceram [TC], Ivoclar Vivadent) when polymerized with a very high intensity (1296 +/- 2 mW/cm2) halogen light (Astralis 10, Ivoclar Vivadent) for 10 seconds. Irradiation with a conventional (494 +/- 3 mW/cm2) halogen light (Spectrum, Dentsply) for 40 seconds was used for comparison. The effectiveness of cure was assessed by computing the hardness gradient between the top and bottom surfaces of 2-mm composite specimens after curing. A strain-monitoring device was used to measure the linear polymerization shrinkage associated with the various composites and curing lights. A sample size of five was used for both experiments. Data was analyzed using ANOVA/Scheffe's post-hoc and Independent Samples t-tests at significance level 0.05. Results showed that the effect of the curing method on the effectiveness of cure and shrinkage was material-dependent. Polymerization of IT and TC with Spectrum for 40 seconds resulted in significantly more effective cure than polymerization with Astralis for 10 seconds. Polymerization of ZO with Spectrum for 40 seconds resulted in significantly more shrinkage than polymerization with Astralis for 10 seconds. In view of the substantial time saving, using high intensity lights may be a viable method to polymerize composites.

Analysis of Variance↗