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Biomedical subjects

S C Chia

Publications and source records attributed to S C Chia.

11 recordsLinked to original sources

Pruritus as a presenting symptom of chronic hepatitis C.

Pruritus is a common symptom in cholestatic liver disease but is rare in chronic hepatitis C. Eight patients with chronic hepatitis C and severe pruritus were compared with regard to biochemical, serological, and histological features to eight disease controls with primary biliary cirrhosis and seven with cirrhosis due to hepatitis C. Among those with severe pruritus associated with chronic hepatitis C, serum aminotransferases were raised in all, alkaline phosphatase in four, and gamma-glutamyl-transpeptidase levels in all except one. Serum cholylglycine levels were elevated in seven of eight patients. Liver biopsies showed moderate to severe fibrosis in all patients and cirrhosis in five. Compared to control subjects with cirrhosis due to hepatitis C but no pruritus, ductopenia, and cholestatic changes were prominent, although less so than in controls with primary biliary cirrhosis. Chronic hepatitis C with moderate to severe fibrosis may result in low-grade cholestasis with pruritus, possibly in association with bile duct disappearance.

Adult

An aflatoxin-associated mutational hotspot at codon 249 in the p53 tumor suppressor gene occurs in hepatocellular carcinomas from Mexico.

The p53 tumor suppressor gene is commonly mutated in human hepatocellular carcinoma (HCC). The most frequent mutation in HCC in populations exposed to a high dietary intake of aflatoxin B1 (AFB1) is an AGGarg-->AGTser missense mutation in codon 249 of the p53 gene. We analyzed HCCs from Monterrey, Mexico, for the codon 249ser hotspot mutation. We also analyzed the serum AFB1-albumin adduct levels of the donors and family members to measure the current AFB1 exposure in this population. Moreover, the presence of hepatitis B and/or C viral infection (HBV or HCV) was analyzed serologically in the patients. Tumor cells were microdissected from tissue sections and exon 7 p53 sequences were amplified by polymerase chain reaction from genomic DNA and sequenced directly. The serological tests for anti-p53 antibodies, HBV or HCV were done by ELISA. Immunohistochemical analysis of p53 protein was done using a polyclonal rabbit antiserum (CM-1). Eight of 21 cases were positive by p53 immunohistochemistry. Of the 16 cases sequenced for exon 7 of p53 three codon 249 AGGarg-->AGTser mutations were found. Serum antibodies recognizing p53 protein were found in one of 18 patients. Positive serology for HBV and/or HCV was found in 12 of 20 cases. The serum AFB1-albumin adduct levels in this population ranged from 0.54 to 4.64 pmol aflatoxin/mg albumin. These results indicate that dietary AFB1 and hepatitis viruses are etiological agents in the molecular pathogenesis of HCC in this geographic region of Mexico.

Adult

Seroprevalence of antibodies against hepatitis A (anti-HAV) in Singapore: the NFDD experience.

At the 4th National Foundation for Digestive Disease (NFDD) Day in 1991 where public lectures on prevention of hepatitis and early detection of hepatocellular carcinoma were given, screening of sera obtained from 364 registrants for antibodies to Hepatitis A (IgG) was undertaken. The overall sero-prevalence rate was 50%, with 55% for males and 46% for females with antibodies for HAV. None of the subjects below 20 years old had antibodies to HAV. This rose to 16% for those 21-30 years old and 92% for those above 61 years. This study shows that in Singapore, prevalence of anti-HAV antibodies rise with age and is approaching the low endemicity pattern that is seen in developed countries.

Adolescent

Clotest (rapid urease test) in the diagnosis of Helicobacter pylori infection.

Over a period of 3 months, 85 patients who underwent gastroscopy had antral biopsy taken for Clotest, histology and/or culture for Helicobacter pylori (HP). The sensitivity and specificity of Clotest were found to be 77% and 96% respectively with negative predictive value of 63% and positive predictive value of 98%. Ninety-two percent of the positive Clotests were positive within 20 minutes, thus giving rapid result. Therefore, Clotest is a rapid, sensitive and highly specific test for HP infection. A high correlation between HP infection and chronic gastritis was noted and the prevalence of HP infection in patients with duodenal ulcer (90%) was higher than that of gastric ulcer (64%) or non-ulcer group (65%).

Adolescent

Prevalence of antibody to hepatitis C in patients with liver disease.

We studied the seroprevalence of antibody to hepatitis C virus (HCV) in patients with liver disease using the Abbott HCV EIA. Twenty-four patients with acute sporadic nonA nonB hepatitis, 19 patients with chronic hepatitis, 28 patients with cirrhosis and 47 patients with hepatocellular carcinoma (HCC) were assayed. The seroprevalence was 8.3% (2/24) in acute hepatitis; 10.5% (2/19) in chronic hepatitis; 3.6% (1/28) in cirrhosis and 14.9% (7/47) in hepatocellular carcinoma. The seroprevalence rates were lower in all categories of liver disease compared to figures reported in developed countries. Possible reasons included a delayed or missed seroconversion in the acute hepatitis group. Other etiologies like hepatitis B and alcohol may play a more important role in chronic liver disease. On the other hand, the seroprevalence locally may actually be low. Sporadic, non-blood transfusion appears to be a common method of acquiring the infection.

Adult

Nizatidine versus cimetidine in the treatment of duodenal ulcers.

An open comparative trial of nizatidine in the treatment of duodenal ulcer (DU) was carried out with cimetidine as control. Forty-three patients with endoscopically proven DU were recruited into the study. Twenty-three patients were assigned to treatment with nizatidine 300 mg daily and 20 patients (controls) were on cimetidine 800 mg daily. Both groups were comparable in age and sex distribution - age range 21 to 74 years; mean 53.4 years and 43 years in the nizatidine and cimetidine groups respectively. Liver function tests, full blood counts, platelets, urea, electrolytes were done together with endoscopy at four, eight, twelve weeks. In the nizatidine group, 16 patients completed the study whilst 17 patients on cimetidine completed the study. Healing rates at four and eight weeks on nizatidine were 9/16 (56%) and 14/16 (87.5%) respectively. On cimetidine, healing rates at four and eight weeks were 14/17 (80%) and 16/17 (94%) respectively. There was no statistical difference in healing rates between the two groups at four and eight weeks (p = 0.1, p = 0.47). One patient on nizatidine developed urticaria rash which resolved on drug withdrawal. No other adverse clinical or biochemical effects were observed in the cohort after twelve weeks of treatment. Nizatidine is as effective as cimetidine in healing DU at four and eight weeks.

Adult

The changing trend in the surgical treatment of macular holes.

The Vitreo-Retinal Service in the past 2 years enjoyed a high level of success in managing retinal detachments arising from macular holes. There was only one recorded failure. Twelve eyes in 11 patients were subjected to various modalities of treatment. This ranged from single out-patient laser photocoagulation to conventional sling procedure and ultimately the complex vitrectomy with its adjust gas-fluid exchange. Numerous intraoperative complications and their remedies were also highlighted. Competency in the management of this rare and difficult condition is an indicator of the maturity of the Vitreo-Retinal Service.

Humans

Peptic ulcer disease in the elderly in Singapore.

Of 460 patients with peptic ulcer disease seen over a 30-month period, there were 174 elderly patients (defined as > or = 60 years old), constituting 38%. In this group of elderly, gastric ulcers (GU) were observed more frequently than duodenal ulcers (DU) with a ratio of 1.6:1 and the male to female ratio was 1.7:1. In patients < 60 years old, there were more DU than GU with a ratio of 2.7:1, and a higher male to female ratio of 3.7:1. Seventy-two per cent of the elderly had at least one other medical condition with 20% having three or more medical problems. Hypertension and ischaemic heart disease were the most frequently encountered illnesses. Half the elderly presented with upper abdominal pain and one-third had an atypical presentation. Analgesic ingestion in the preceding 4 weeks was present in 29% of the elderly. In the elderly, bleeding was the most frequent complication occurring in 50%; perforation occurred in 2%. In those with bleeding ulcers, 44% had history of analgesic usage. The mortality of bleeding peptic ulcer in the elderly, was 11% and this was largely due to concurrent medical conditions. Only two deaths occurred due to bleeding ulcer.

Aged

Endoscopic adrenaline injection in treatment of bleeding peptic ulcers.

This study aimed to compare the results of bleeding peptic ulcer treated by endoscopic adrenaline injection with controls treated conventionally. Between January 1991 and December 1993, 69 patients with actively bleeding peptic ulcers with visible vessel received endoscopic adrenaline injection. This group of patients was compared with 31 endoscopically similar patients treated conventionally, using H2 blockers with or without surgery, from October 1987 to December 1990 prior to the introduction of endoscopic injection therapy in this hospital. Both groups of patients were comparable in terms of age, haemoglobin level on admission and site of ulcer (gastric or duodenal). Permanent haemostasis was attained with endoscopic adrenaline injection in 97% of our patients. Rebleeding occurred in 9% in the injected group vs 39% in the historical control group (p < 0.005). Three percent of patients in the injected group had emergency surgery compared with 48% in the control group (p < 0.005). The median hospital stay and transfusion requirements in the injected group were 6 days and 2 units respectively vs 8 days and 3 units in the control group but the difference was not statistically significant. We conclude that endoscopic adrenaline injection is effective in the treatment of bleeding peptic ulcer leading to a reduction in rebleeding rate and emergency surgery.

Adult