MyMedR

Intra- and interspecific agonistic behavior of the subterranean termite Microcerotermes crassus (Isoptera: Termitidae)

Wong N, Lee CY

J Econ Entomol, 2010 Oct;103(5):1754-60.

PMID: 21061976

The aim of our study was to investigate the intra- and interspecific agonistic behaviors exhibited by the worker and soldier castes of the subterranean termite Microcerotermes crassus Snyder (Isoptera: Termitidae). Aggression between M. crassus colonies from different field locations and also against three termite species--Coptotermes gestroi (Wasmann), Globitermnes sulphureus Haviland, and Odontotermes sp.--were observed in the laboratory. Termite responses were tested in paired combination of castes (soldiers versus soldiers, soldiers versus workers, and workers versus workers) consisting of 10 individuals each. Significant agonistic behaviors were observed only in encounters between pairings of different termite species. M. crassus was aggressive toward individuals from different species but not toward individuals from different M. crassus colonies. Mortality of M. crassus reached 100% in most of the interspecific encounters. However, no or low mortality was recorded in the intraspecific pairings.

Influence of different substrate moistures on wood consumption and movement patterns of Microcerotermes crassus and Coptotermes gestroi (Blattodea: Termitidae, Rhinotermitidae)

Wong N, Lee CY

J Econ Entomol, 2010 Apr;103(2):437-42.

PMID: 20429460

Moisture is an important physical factor for the survival of termites. The effects of different moisture levels (0, 5, 10, 15, 20, and 25%) of a sand substrate on the behavior of laboratory groups of Microcerotermes crassus Snyder and Coptotermes gestroi (Wasmann) (Blattodea: Termitidae: Rhinotermitidae) were evaluated. Moisture content of sand affected wood consumption and influenced termite distribution across a moisture gradient for M. crassus. Changing the moisture parameters affected the location preference of C. gestroi, but the effect on wood consumption was not significant. Nonetheless, M. crassus and C. gestroi showed a similar distribution pattern of association with particular moisture levels.

Relationship between population growth of the red flour beetle Tribolium castaneum and protein and carbohydrate content in flour and starch

Wong N, Lee CY

J Econ Entomol, 2011 Dec;104(6):2087-94.

PMID: 22299375

The effects of eight diets (atta flour, wheat flour, self-rising flour, rice flour, custard powder, corn flour, tapioca starch, and potato starch) on the development of the red flour beetle, Tribolium castaneum (Herbst), reared at 29-31 degrees C and 66-70% RH were assessed. Five pairs of male and female T. castaneum were reared on the respective diets for 28 d before the experimental setup was dismantled and adult counts were recorded. In another experiment, the insects were allowed to mate and oviposit in each flour or starch type over a period of 7 d before being removed. The counting of pupae and adult emergence began on the day of emergence and was continued on a daily basis until day 140. Proximate analysis was performed for chemical composition of each diet, and the numbers of new adults that developed were found to be positively correlated (r2 = 0.97; P < 0.05) with the protein content and negatively correlated (r2 = 0.93; P < 0.05) with the carbohydrate content. For T. castaneum, the suitable diets were ranked as follows: atta flour > wheat flour > self-rising flour > rice flour > custard powder > corn flour > tapioca starch > potato starch. T. castaneum larval development to the pupal and adult stages developed significantly faster in atta flour (P < 0.05) than in the other diets, and the greatest number of progeny was produced from beetles reared on atta flour. Fewer adults emerged from wheat flour, self-rising flour, and rice flour, and no new emergences were recorded for the remaining diets. Developmental rate was much slower in beetles reared on diets in which a low number in progeny was produced. These data illustrate that different diets can influence the sustainability of these insects and affect their development and growth.

Fulltext Survival in hepatitis-B cirrhosis compared to alcoholic cirrhosis in patients with Child's C liver disease: a prospective study of endoscopic sclerotherapy for bleeding oesophageal varices

Lee SM, Wong NW

Singapore Med J, 1994 Feb;35(1):53-6.

PMID: 8009280

A prospective comparative study was carried out on thirty-seven consecutive patients presenting with bleeding oesophageal varices at University Hospital, Kuala Lumpur. All patients received injection sclerotherapy if active bleeding was seen at the time of initial endoscopy, followed by repetitive courses of sclerotherapy to obliterate the varices. Predominant aetiological factors were hepatitis-B cirrhosis (43%) and alcoholic cirrhosis (30%). Chinese ethnic group accounted for 62.5% of hepatitis-B cirrhotics and Indian 73% of alcoholic cirrhotics. After excluding patients lost to follow-up, analysis of the remaining thirty-four patients showed reduced long-term survival in patients with Child's C disease. Log-rank analysis of survival curves between hepatitis-B cirrhosis and alcoholic cirrhosis in patients with Child's C liver disease showed no significant difference in long-term survival (p = 0.07). However, six deaths were seen in hepatitis-B cirrhosis compared to one death in alcoholic cirrhosis in the first eight months of follow-up. Most patients died from progressive liver failure. Median survival for Child's C hepatitis-B cirrhosis was 7.5 months whereas this had not been reached for Child's C alcoholic cirrhosis (median follow-up 11.6 months). We conclude that variceal haemorrhage in Child's C hepatitis-B cirrhosis is a bad prognostic sign and is associated with reduced survival with a median survival of 7.5 months despite control of the variceal bleed.

Fulltext Common anxieties of patients undergoing oesophago-gastro-duodenoscopy, colonoscopy and endoscopic retrograde cholangio-pancreatography

Chuah SY, Goh KL, Wong NW

Med J Malaysia, 1999 Jun;54(2):216-24.

PMID: 10972032

To investigate the anxieties of patients undergoing oesophago-gastro-duodenoscopy (OGD), colonoscopy and endoscopic retrograde cholangio-pancreatography (ERCP) in relation to their demographic features, their knowledge and understanding of the procedure, its indication, and their doctors' explanation. A standard questionnaire was filled in consecutively for 280 OGD patients, 64 colonoscopy patients and 50 ERCP patients.

Risk factors for developing neonatal septicaemia at a Malaysian hospital

Wong NA, Hunt LP, Marlow N

J Trop Pediatr, 1997 02;43(1):54-8.

PMID: 9078832 DOI: 10.1093/tropej/43.1.54

A case-control study of antecedents of neonatal septicaemia was performed using 50 cases of neonatal septicaemia and 73 comparison infants from a Malaysian hospital nursery. Multivariate analysis indicated the following independent risk factors: maternal primiparity, pre-eclampsia, prolonged rupture of membranes, twin pregnancy, prematurity, assisted ventilation, umbilical catheterization, and formula feeding. Although the spectrum of causative organisms varied between our study and past studies from Western countries, the risk factors for developing neonatal septicaemia were strikingly similar. Therefore, preventative guidelines based on risk factors described in Western countries, should help reduce the incidence of neonatal septicaemia at this Malaysian hospital.

Serum hepatitis B virus DNA: relationship with the e-antigen and anti-e status in chronic carriers

Yap SF, Wong NW, Goh KL

Malays J Pathol, 1994 Jun;16(1):57-62.

PMID: 16329577

The relationship between serum Hepatitis B virus DNA (HBV-DNA) and the Hepatitis B e-antigen/ anti-Hepatitis Be (HBeAg/anti-HBe) serological status in Malaysians was studied. 212 cases of asymptomatic HBV carriers were recruited for this study. 92 cases were positive for the HBeAg at the point of recruitment. 85 (92.4%) of these patients tested positive for HBV-DNA, of whom 55 (64.7%) had levels over 100pg/ml of serum. Three of the remaining 7 HBeAg positive cases who were negative for HBV-DNA subsequently seroconverted. The other 4 cases remained negative for HBV-DNA for periods of 6-12 months. Out of 113 cases who were anti-HBe positive, 12 (10.6%) gave a positive HBV-DNA result. 2 of these 12 patients were recent seroconverters; the remaining cases had transiently increased viral replicative activity which later subsided. 7 out of the 212 carriers were in the e-window period; all 7 tested negative for HBV-DNA. Our data confirm a high frequency of HBV-DNA in HBeAg positive carriers and a negative correlation between HBV-DNA and anti-HBe. An atypical profile of anti-HBe associated with HBV-DNA was observed in 10.6% of the carriers. An inverse relationship between serum HBV-DNA levels and age was also observed.

Fulltext Primary biliary cirrhosis--experience in University Hospital, Kuala Lumpur

Mohammed R, Goh KL, Wong NW

Med J Malaysia, 1996 Mar;51(1):99-102.

PMID: 10967987

Primary biliary cirrhosis is an uncommon disease amongst Malaysians. Over a 12-year period, between 1979 and 1991, only seven patients with clinical, biochemical and histologic evidence of primary biliary cirrhosis were identified in University Hospital Kuala Lumpur. All were Chinese females between the ages of 30 to 55 years. The presenting complaint was pruritus in 5 patients. All except one patient was jaundiced when the diagnosis was made. These patients were followed up from 1 to 11 years. Three deaths were reported, one from massive hemetemesis and two from liver failure.

Microscopic colitis: a histopathological study of nine cases

Jayalakshmi P, Malik AK, Wong NW

Malays J Pathol, 1994 Dec;16(2):145-50.

PMID: 9053563

A retrospective histological analysis of colonic biopsies received by the Department of Pathology, University of Malaya during the 4-year-period between 1990 and 1993 revealed nine cases of microscopic colitis (MC). The ages of the patients ranged from 18 to 53 years. Seven patients were females with a female to male ratio of 3.5 :1. The main clinical symptom was chronic diarrhoea of duration varying from 4 months to 5 years. None of the patients had any systemic illness or were on any prior medication. Colonoscopy and barium enema observations in all the subjects were essentially normal. Colonic biopsies showed diffuse plasmacytic infiltration of the lamina propria, intraepithelial lymphocytic infiltration and normal crypt pattern. To the best of our knowledge, this is the first documented report on MC from Malaysia. It is envisaged that better recognition of this condition by histopathologists would reduce the numbers in the often diagnosed category of "nonspecific colitis".

Fulltext Lethargy in a patient with cirrhosis

Chuah SY, Wong NW, Goh KL

Postgrad Med J, 1997 Mar;73(857):177-9.

PMID: 9135840 DOI: 10.1136/pgmj.73.857.177

Fulltext Wilson's disease--a review of cases at University Hospital, Kuala Lumpur

Mohamed R, Tan CT, Wong NW

Med J Malaysia, 1994 Mar;49(1):49-52.

PMID: 8057991

The clinical course of 18 patients with Wilson's disease is reported. There were 13 males and five females of whom one is Malay. The prevalence of Wilson's disease in Malaysia is probably the same as elsewhere. Being a genetic syndrome, the genetic carrier rate for Wilson's disease is probably lower amongst the Malays. At diagnosis, the clinical signs were predominantly hepatic in 10 patients, neurological in five patients with three asymptomatic cases. All patients were commenced on penicillamine but poor compliance was observed in many patients. Two patients defaulted follow-up and seven patients died. Out of the nine surviving patients, only four are well with no clinical symptoms.

Fulltext Pseudomembranous colitis: local experience with 3 cases

Goh KL, Peh SC, Wong NW

Med J Malaysia, 1986 Dec;41(4):347-51.

PMID: 3670159

Three cases of pseudomembranous colitis seen over the past one year in the Medical Unit, University Hospital, Kuala Lumpur, are reported.
The historical background, spectrum of clinical presentation, diagnosis and treatment of the disease are discussed. Early and wider use of sigmoidoscopy in patients with predisposing factors to pseudomembranous colitis have resulted in increased diagnosis of the condition.

Fulltext Endoscopy in upper gastrointestinal haemorrhage

Jalleh RP, Goh KL, Wong NW

Med J Malaysia, 1988 Sep;43(3):213-7.

PMID: 3266521

Fulltext Use of a mindfulness application to promote students' mental well-being during COVID-19-era

Rath A, Wong M, Wong N, Brockman R

J Dent Educ, 2021 Dec;85 Suppl 3:2049-2051.

PMID: 33893747 DOI: 10.1002/jdd.12635

Risk factors associated with umbilical vascular catheter-associated thrombosis in newborn infants

Boo NY, Wong NC, Zulkifli SS, Lye MS

J Paediatr Child Health, 1999 Oct;35(5):460-5.

PMID: 10571759

OBJECTIVE: To determine the risk factors associated with umbilical vascular catheter-associated thrombosis.

METHODS: All consecutive inborn infants with umbilical arterial (UAC) and/or umbilical venous catheters (UVC) inserted for more than 6 h duration were included in the study. Each infant was screened for thrombosis in the abdominal aorta and inferior vena cava by 2-D abdominal ultrasonography within 48-72 h of insertion of umbilical vascular catheters. Subsequent serial scanning was performed at intervals of every 5-7 days, and within 48 h after removal of catheters.

RESULTS: Upon removal of umbilical catheters, abdominal aortic thrombi were detected in 32/99 (32.3%) infants with UAC. Small thrombi were detected in the inferior vena cava of 2/49 (4.1%) infants with UVC (one of whom had both UAC and UVC). When compared with those who received only UVC (n = 18), infants who received either UAC alone (n = 68) or both UAC and UVC (n = 31) had significantly higher risk of developing thrombosis (odds ratio (OR): 7.6, 95% confidence interval (CI): 1.1, 325.5)). Logistic regression analysis of various potential risk factors showed that the only significant risk factor associated with the development of abdominal aortic thrombosis following insertion of UAC was longer duration of UAC in situ (for every additional day of UAC in situ, adjusted OR of developing thrombosis was: 1.2, 95% CI: 1.1, 1.3; P = 0.002).

CONCLUSION: Umbilical arterial catheter-associated thrombosis was common. Umbilical arterial catheter should be removed as soon as possible when not needed. Upon removal of UAC, all infants should be screened for abdominal aortic thrombus by 2-D ultrasonography.

Randomly amplified polymorphic DNA typing: a useful tool for rapid epidemiological typing of Klebsiella pneumoniae

Wong NA, Linton CJ, Jalal H, Millar MR

Epidemiol Infect, 1994 Dec;113(3):445-54.

PMID: 7995354

Discriminatory typing methods are invaluable in the investigation of outbreaks of infectious diseases. Single primers were used to generate randomly amplified polymorphic DNA (RAPD) profiles from Klebsiella pneumoniae isolates of various serotype and K. pneumoniae isolates from cases of sepsis at a Malaysian hospital and two English hospitals. RAPD profiles of acceptable reproducibility, a maximum of three minor band variations, were produced using a rapid DNA extraction method. RAPD typing of K. pneumoniae was shown to be as discriminatory as restriction fragment length polymorphism analysis using pulsed field gel electrophoresis yet quicker and less costly. The findings suggest that RAPD typing may be a useful tool for the epidemiological typing of K. pneumoniae.

Liver abscess in the tropics: experience in the University Hospital, Kuala Lumpur

Goh KL, Wong NW, Paramsothy M, Nojeg M, Somasundaram K

Postgrad Med J, 1987 Jul;63(741):551-4.

PMID: 3658864

We reviewed 204 cases of liver abscess seen between 1970 and 1985. Ninety were found to be amoebic, 24 pyogenic and one tuberculous. The cause of the abscesses in the remaining 89 patients was not established. The patients were predominantly male, Indians, and in the 30-60 age group. The majority of patients presented with fever and right hypochondrial pain. The most common laboratory findings were leucocytosis, hypoalbuminaemia and an elevated serum alkaline phosphatase. Amoebic abscesses were mainly solitary while pyogenic abscesses were mainly multiple. Complications were few in our patients and included rupture into the pleural and peritoneal cavities and septicaemic shock. An overall mortality of 2.9% was recorded. The difficulty in diagnosing the abscess type is highlighted. The single most important test in helping us diagnose amoebic abscess, presumably the most common type of abscess in the tropics, is the Entamoeba histolytica antibody assay. This test should be used more frequently in the tropics.

Campylobacter pylori infection: experience in a multiracial population

Goh KL, Peh SC, Wong NW, Parasakthi N, Puthucheary SD

J Gastroenterol Hepatol, 1990 5 1;5(3):277-80.

PMID: 2103410

Over a 15-month period, 399 patients with dyspepsia were investigated for the presence of Campylobacter pylori infection. Half of the patients (50.6%) had Campylobacter organisms in the antrum of the stomach. C. pylori was found in 96.1% of patients with histological changes of chronic active gastritis in the antrum. Of patients with duodenal and gastric ulcers, 87.8% and 87.5%, respectively, had Campylobacter organisms, as did 39.3% of patients with non-ulcer dyspepsia. C. pylori infection was most commonly found in Chinese and Indians. Although the prevalence of infection appeared to increase with age, there was an equal distribution amongst the sexes.

Tuberculous liver abscess

Goh KL, Pathmanathan R, Chang KW, Wong NW

J Trop Med Hyg, 1987 Oct;90(5):255-7.

PMID: 3669128

Tuberculous liver abscess is uncommonly seen in our experience. We report a case of a 17-year-old boy who presented with typical clinical features of liver abscess, where a diagnosis of tuberculous liver abscess was made on laparotomy and biopsy of the abscess wall.

Fulltext Ulcerative colitis in Malaysians

Jayalakshmi P, Wong NW, Malik AK, Goh KL

JUMMEC, 1996;1(2):39-42.

A review of all colonic biopsies received by the Department of Pathology during a 8-year period revealed 41 cases of ulcerative colitis (UC). The diagnosis was based on histological and clinical features. The age range of patients was between 14 - 76 years with a median age of 35.4 years. The disease was more prevalent among Indians. The common presenting sysmptoms were diarrhoea (100%) and haematochezia (83%). The extent of colonic involvement varied. Twelve patients (29.2%) had pancolitis and 8 (19.5%) had proctitis.Extraintestinal manifestations were rare and only one patient had pyoderma gangrenosum. One patient developed multifocal colorectal cancer 10 years after the inial diagnosis of UC and died 2 years later due to metastases. Histology plays an important role in the diagnosis and management of patients with UC. We noted a good correlation between clinical and pathological features. The most recent colonic biopsy showed features of chronic UC with activity in 34 cases and features of remission in 4 cases.

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