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Biomedical subjects

S H Quak

Publications and source records attributed to S H Quak.

At least 55 records · Page 3Linked to original sources
PubMed1991

Cell-mediated immunity in patients on hemodialysis: relationship with hepatitis B carrier status.

We compared cell-mediated immune responses in two groups of patients on hemodialysis. One group of patients were chronic carriers of hepatitis B virus (HBV), and the patients of the other group were HBV antigen negative. Our results show that despite the presence of normal numbers of T cells and an increased CD4/CD8 ratio in both groups of patients compared to healthy controls (p less than 0.0001), only the group of patients who were chronic HBV carriers showed depressed lymphoproliferative responses to phytohemagglutinin (p less than 0.001) and concanavalin A (p less than 0.0001). In contrast, a control group of healthy adult HBV carriers showed normal T cell subsets and lymphoproliferative responses to mitogens, indicating that HBV infection per se did not result in depressed lymphoproliferative responses. These results further substantiate the notion that depressed cell-mediated immunity in chronic renal failure is an important factor in predisposing patients to HBV infection with subsequent development of the chronic carrier state.

Adult↗
PubMed1991

Pre-liver transplantation management of children.

Liver transplantation is the accepted treatment for children with end-staged liver diseases nowadays. Currently, the five year actuarial survival rate is about 80%. In children, the most common indication for transplantation is biliary atresia. Due to shortage of donor organs, portoenterostomy is still the initial treatment of choice for young infants with biliary atresia. This will enable the affected infants to continue growing until a suitable donor organ is available. There are a few absolute contraindications to liver transplantation in children. Severe irreversible disease in any other organs and poor psychosocial support are indications for not performing liver transplantation. Appropriate pre-operative assessment and preparations are necessary for a successful transplant. Post-operative course may be marred by rejection, infections and surgical complications. Long term immunotherapy is necessary.

Child↗
PubMed1991

Chronic diarrhoea in children: a clinical perspective.

Chronic diarrhoea in its previously described severe malnourished presentation is not common in Singapore. A retrospective study was made of children with chronic diarrhoea between January to September 1990, at the Department of Paediatrics, National University Hospital. Chronic diarrhoea in our context included all those who presented with diarrhoea of 7 or more days duration. The age range was one month to 11 years, with 23 males and 13 female patients. Approximately half of the patients had associated symptoms like fever. Anthropometric data of these patients revealed none less than the third percentile in height and weight. Clinically the patients were mainly well nourished, mildly dehydrated with no significant pallor or oedema. Perianal erythema though not excoriation was common being present in approximately 50%. Haematological parameters and electrolytes were generally normal. Mild elevation of urea and creatinine levels especially the former was present reflecting the relatively mild dehydration status. Infection was the main cause of the diarrhoea, 55% of stool cultures being positive mainly for Salmonella or rotavirus. Treatment was mainly directed at correcting dehydration. 40% needed antibiotics. Hence, chronic diarrhoea as seen in the National University Hospital is generally not debilitating. An infective cause must first be excluded with usage of antibiotics often necessary in young children.

Anthropometry↗
PubMed1991

Non-neurological manifestations of intracranial tumours: a report of four cases.

Brain neoplasms are a common cause of childhood morbidity and mortality. Neurological presentations usually result in a relatively early diagnosis and management of the neoplasms. Non neurological manifestations may result in later detection and possibly a higher eventual morbidity and mortality. Hence, the importance of a keen index of suspicion in assessment of cases to detect subtle neurological signs and symptoms. Cranial magnetic resonance imaging has been found to be especially useful in the definition of brain neoplasms. In this paper, four cases with non neurological manifestations are presented (one diencephalic syndrome, one failure to thrive, one precocious puberty and one gastrointestinal symptoms).

Brain Neoplasms↗
PubMed1991

Gastrointestinal infections in Singapore children.

Acute gastroenteritis is the commonest gastrointestinal disorder in children. It accounted for about 10% of the admissions to a general paediatric unit in Singapore. About 5% of total paediatric admissions to all the government hospitals in Singapore were due to acute gastroenteritis. Some 50% of the cases had no identifiable organism in the stools. Most of the remaining cases were due to bacterial or viral infections. The commonest bacteria responsible for acute gastroenteritis nowadays is Salmonella species. Other bacteria such as E. coli, Shigella and Campylobacter were responsible for a smaller proportion of bacterial diarrhoea in children. Rotavirus was the commonest viral agent responsible for acute diarrhoea among Singapore children. Most patients had mild diarrhoea and severe dehydration following acute gastroenteritis was not common. About 60% of the patients admitted to hospital were younger than two years of age. Bacterial infections were more common in infancy. Viral diarrhoea were more likely to be watery and bacterial diarrhoea were more likely to be bloody and mucoid. With regard to chronicity, it was the groups with mixed infection or bacteria infection which had a prolonged course. Treatment was directed at maintaining hydration and prevention of complications. Except for secondary lactase deficiency, other long term complications were rare.

Adolescent↗
PubMed1990

Incidence, clinical features and epidemiology of rotavirus gastro-enteritis in hospitalized children.

Two hundred and eighteen patients with acute gastro-enteritis (GE) and 67 controls (patients admitted during the period of study for illness other than (GE) were included in this study. Their stool samples were subjected to the following tests to detect the presence of rotavirus: enzyme-linked immunosorbent assay (ELISA), latex agglutination and electron microscopy. Samples positive by any one or more of the above methods were considered positive for rotavirus and were subjected to polyacrylamide gel electrophoresis of viral RNA. Rotavirus was detected in 59 (27.1%) of the 218 GE samples and four (6%) of the control samples. ELISA was the most sensitive test and could detect viral antigen long after the other methods failed to do so.

Child↗
PubMed1990

Colonoscopy in children with bleeding per rectum.

There are few reports of colonoscopy in children. Twenty-six children with bleeding per rectum were examined colonoscopically to determine the aetiology of the bleeding. A total of 32 colonoscopies were performed. Except for 5 children who needed general anaesthesia, all the rest were performed with pethidine and diazepam sedation. The mean age of these 26 children was 63.5 months (SD 57.5 months, range 2 weeks to 180 months). Ten children had histologically confirmed colitis. Five had bleeding juvenile polyps and these were removed endoscopically. One had lymphoid hyperplasia and one had chronic solitary sigmoid ulcer. The rest were normal. It is concluded that colonoscopy can be performed safely in children and it is a good diagnostic and therapeutic procedure.

Child, Preschool↗
PubMed1990

Upper gastrointestinal endoscopy in children.

The purpose of this paper is to study the use of upper gastrointestinal (Gl) fiberoptic endoscopy in children. Two hundred consecutive patients referred to one of the authors were reviewed. The indications for performing upper gastrointestinal endoscopy in these 200 patients were: (1) recurrent abdominal pain (46.5%), (2) persistent vomiting (14.5%), (3) haematemesis (14.5%), (4) acute abdominal pain (13%) and (5) other indications such as foreign body removal, failure to thrive and unexplained chest pain (11.5%). The endoscopy was performed with the Olympus P3 or Olympus XP-10 gastroscopes. The sedation used was a combination of intravenous pethidine (2mg/kg) and diazepam (0.5 mg/kg). Among the patients with recurrent abdominal pain, upper Gl endoscopy showed duodenal ulcer in 7 patients (7.5%), duodenitis in 4 (4.3%), oesophagitis in 4 (4.3%) and gastric ulcer in 2 (2.2%). The rest of the patients were normal (81.7%). With regard to persistent vomiting, 37.9% of the patients showed gastroesophageal reflux and 6.9% had a hiatus hernia. Of 29 patients examined endoscopically for upper Gl bleeding, no focus of bleeding was identified in 27.6%. The remaining 72.4% were bleeding from acute gastric erosion (27.6%), oesophagitis (17.2%), oesophageal varices (13.8%), duodenal ulcer (10.3%) and Mallory-Weiss tear (3.5%). The Majority of the patients with acute abdominal pain were normal endoscopically (61.5%). The two common abnormal findings were acute gastritis (27.0%) and acute duodenitis (11.5%). No major complications were encountered during the procedure in these 200 patients. It was concluded that upper Gl endoscopy is useful for defining upper Gl mucosal pathology. The procedure can be performed safely in children under sedation.

Child↗
PubMed1989

Accuracy of anorectal manometry in the diagnosis of Hirschsprung's disease.

The value of anorectal manometry as a diagnostic tool for Hirschsprung's disease (HD) was assessed in 50 children presenting with chronic constipation. Anorectal manometric studies and rectal biopsy were performed on all children. Biopsy specimens were stained with hematoxylin and eosin and serial sections were examined for ganglion cells. Forty-five children had concordant manometric and histologic results, 15 of whom were positive for HD and 30 negative. In five children, the results were discordant. Using histologic aganglionosis as the reference point for the final diagnosis of HD, the overall accuracy of anorectal manometry as a discriminative test was 90.0%. The sensitivity, specificity, and positive and negative predictive values of manometric studies for the diagnosis of HD were 0.79, 0.97, 0.94, and 0.88, respectively. Factors responsible for the inaccuracies of manometric studies are discussed.

Anal Canal↗
PubMed1989

Glucose-galactose malabsorption--a report in a Chinese family.

Glucose-galactose intolerance is a rare form of monosaccharide malabsorption. We report a Chinese family with 2 affected male children. They presented with watery diarrhoea since birth and the diarrhoea improved only after the offending carbohydrates were withdrawn from the diet.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1988

Vasoactive intestinal peptide secreting tumours in children: a case report with literature review.

A 3 year old Chinese girl with watery diarrhoea, abdominal distension and hypokalaemia due to a thoracic paraspinal vasoactive intestinal peptide (VIP) secreting ganglioneuroma is reported. The pre-operative serum VIP was 314 pmol/l (normal less than 30). Her diarrhoea stopped after the removal of the tumour. The VIP was 14 pmol/l 6 months post-operatively. Review of the 19 reported cases in children with documented elevated serum VIP showed that many of the cases presented with watery diarrhoea for prolonged duration before the diagnosis was made. Earliest age of onset was 2 weeks of age. The male to female ratio was 9:10. Ganglioneuroma and ganglioneuroblastoma were the commonest tumours. Pancreatic non-beta cell hyperplasia and neurofibroma were also reported. Location of the tumour was variable: neck, chest or abdomen. Increased urinary catecholamine excretion was reported in 50% of the cases. Abdominal distension, flushing, episodic hypertension and failure to thrive were the other associated features.

Adenoma, Islet Cell↗