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Biomedical subjects

S K Chong

Publications and source records attributed to S K Chong.

At least 37 records · Page 2Linked to original sources
PubMed1996

Evaluation of 16S rRNA gene PCR with primers Hp1 and Hp2 for detection of Helicobacter pylori.

The PCR primer set Hp1-Hp2, which amplifies a 109-bp fragment of the 16S rRNA gene of Helicobacter pylori, has been widely used for the detection of H. pylori in clinical specimens. We have examined 34 stool samples and 50 human tissue samples from H. pylori-infected and uninfected patients, five human leukocyte samples, and one human cell line by this PCR method. All of these specimens produced a 109-bp PCR product. When Escherichia coli DNA was used as the template, several nonspecific bands, but not the 109-bp band, were observed. No PCR products were generated when DNA samples from five different fungi were used as templates. These results indicate that this 109-bp PCR product was amplified from the human genome. The 109-bp PCR product generated from various clinical specimens also hybridized with the probe pHp, corresponding to a region internal to the PCR product of Hp1-Hp2. We conclude that the 16S rRNA gene PCR with the primer set Hp1-Hp2 is not specific and cannot be used to detect H. pylori in clinical specimens.

Bacteriological Techniques↗
PubMed1995

Fetal tissue derived from spontaneous pregnancy losses is insufficient for human transplantation.

OBJECTIVE: To determine if sufficient fetal tissue with desirable transplant characteristics can be obtained from spontaneous abortions. METHODS: A survey of fetal tissues collected from newly diagnosed spontaneous pregnancy losses from three Indianapolis hospitals was conducted from December 1992 to September 1993. Forty-nine of 356 mothers (13.8%) with spontaneous abortions or ectopic pregnancies consented to the evaluation of their products of conception by gross and microscopic pathologic examination, bacterial culture, cytogenetic analysis, cell culture, and maternal serologic tests. RESULTS: Forty-nine pregnancies (gestational age range 5-30 weeks) provided four identifiable embryos, 12 second-trimester fetuses, and one third-trimester fetus. Nine samples (18.4%) were of excellent or good quality on pathologic grading. Twenty-five of 38 samples tested (66%) grew pathogenic bacteria. Maternal serologic tests were negative for antibodies to human immunodeficiency virus, human T-cell lymphotropic virus, syphilis, and hepatitis B in all cases. One of 43 sera was reactive for hepatitis C, and 33 (77%) were positive for cytomegalovirus. Cytogenetic abnormalities were found in 25% of cultured samples. Five fetal brain samples had cell viabilities of 50% or more. Few viable fetal hepatocytes were found. Only two fetal brain samples (4.1%) were potential candidates for human transplantation. CONCLUSION: Spontaneous pregnancy losses yield minimal usable tissue for human transplantation because of a lack of embryonic or fetal tissues, delayed collection, decomposition, genetic abnormality, and bacterial contamination.

Abortion, Spontaneous↗
PubMed1995

Colonic strictures in children with cystic fibrosis.

PURPOSE: To determine the radiographic, clinical, surgical, and histologic findings in children with cystic fibrosis who develop strictures of the colon. MATERIALS AND METHODS: Ten children (five boys, five girls; age range, 2.5-9.0 years; mean age, 5.5 years), who were treated at the practices of the authors, were retrospectively identified and their medical records reviewed. RESULTS: Radiographic manifestations of the colonic disease included mucosal irregularity and spiculation with nodular thickening of the colonic wall and loss of normal colonic haustration. Luminal narrowing involved long segments of the colon. Longitudinal shortening of the colon was also a prominent feature. The decrease in caliber of the bowel ranged from mild narrowing to complete occlusion of the lumen. Histologic examination revealed severe submucosal fibrosis and fatty infiltration with transmural extension of the fibrosis to involve the serosa in some cases. Unlike in Crohn disease, however, acute inflammatory changes were minimal or absent. CONCLUSION: Colonic stricture in children with cystic fibrosis is due to irreversible and frequently progressive narrowing of the colonic lumen.

Child↗
PubMed1995

Helicobacter pylori infection in recurrent abdominal pain in childhood: comparison of diagnostic tests and therapy.

OBJECTIVE: To determine the role of Helicobacter pylori infection in children with recurrent abdominal pain and the usefulness of serologic tests in screening H pylori infection and monitoring treatment of H pylori-associated gastritis. METHODS: During a 3 year period, we investigated the presence of serum immunoglobulin G (IgG) antibody to H pylori in 456 children using the high-molecular-weight cell-associated protein H pylori enzyme immunoassay kit. Among the 456 children studied, 218 (age range, 3 to 18 years; mean age, 9.5 years) had symptoms of recurrent abdominal pain (RAP syndrome) with or without vomiting, and the remaining 238 (age range, 3 to 18 years; mean age, 9.8 years) had no RAP (non-RAP syndrome). We performed upper gastrointestinal endoscopy on 111 consecutive children of the 218 with RAP syndrome and obtained mucosal biopsies for culture, histologic analysis, CLO test (Delta West, Perth, Australia), and H pylori detection by polymerase chain reaction. RESULTS: Thirty-eight (17.4%) of 218 children in the RAP group and 25 (10.5%) of 238 children in the non-RAP group were seropositive for H pylori. Of the 111 children endoscoped, 95 were found to be negative, and 12 were positive by all five assays. Specimens from 2 children were negative by culture and the CLO test but positive by the other three assays. Specimens from 1 child were negative by histologic analysis but positive by all other tests. The remaining child was positive for anti-H pylori IgG but negative by all of the other four assays. Upper gastrointestinal endoscopy detected 14 children with peptic ulcer disease (9 duodenal ulcer and 5 gastric ulcer) and 12 with antral nodular gastritis. Only 4 of the 14 diagnosed with peptic ulcer were H pylori positive by all five assays, whereas all 12 children with antral nodular gastritis were H pylori positive. Nine of the 12 H pylori-positive children were treated with a combination of bismuth subsalicylate, amoxicillin, and metronidazole for 2 weeks. Sera obtained at 2, 4, and 6 months after treatment from all 9 children showed a decrease in anti-H pylori IgG titer. Three H pylori-infected children who did not receive any treatment served as control children, and their IgG levels remained elevated or increased over time. CONCLUSION: The results from our study indicate that screening for the serum IgG antibody to H pylori is a practical method for diagnosing H pylori infection in children, and that serial measurements of the H pylori IgG antibody are useful for monitoring treatment of H pylori because of its high sensitivity and ease of performance. Only 4 of the 14 children diagnosed with peptic ulcer disease were confirmed to be infected with H pylori, whereas all 12 children with antral nodular gastritis were found to be infected by H pylori. These observations suggest that H pylori infection is more frequently associated with gastritis than with peptic ulcer disease in children, and that H pylori gastritis is a cause of RAP syndrome in children.

Abdominal Pain↗
PubMed1990

A prospective study of viral and mycoplasma infections in chronic inflammatory bowel disease.

Seventy-two children with chronic inflammatory bowel disease were investigated for infections with various viruses and Mycoplasma pneumoniae, Chlamydia psittaci, and Coxiella burnetii to determine whether these pathogens are associated with acute onset exacerbations. Altogether 54 infections were identified serologically, of which 23 (42.6%) were associated with exacerbations. This corresponded to 24.2% of the recorded exacerbations during the study period. The respiratory pathogens accounted for 59.3% of the infections and 43.8% of these were associated with gastrointestinal symptoms. This is consistent with the observation that up to 40% of the exacerbations were associated with symptoms of antecedent or concurrent infection, most commonly involving the respiratory tract. Rubella virus, Epstein-Barr virus, and adenovirus were associated with acute exacerbations in 5 children. Thus, common pathogens were frequently associated with exacerbations and account for a large proportion of the commonly reported symptoms of a concurrent infection. The possible causal relationship between these pathogens and exacerbation of inflammatory bowel disease is discussed. Reactivation of latent herpesviruses was identified in 4 children with active disease and indicates that the converse relationship may also occur.

Acute Disease↗
PubMed1989

Subarachnoid cyst with hydrocephalus--a complication of mid-trimester amniocentesis.

We report a child with a subarachnoid cyst with hydrocephalus following a mid-trimester amniocentesis. Although fetal trauma is a rare complication, it is important to stress the need to perform amniocentesis under ultrasound control. Children with neurological disease or convulsions of unknown origin in early infancy who are born to mothers who have had mid-trimester amniocentesis should have a CT scan as part of the investigations to exclude this rare but nevertheless important complication.

Adult↗
PubMed1989

Exocrine pancreatic insufficiency in syndromic paucity of interlobular bile ducts.

Severe failure to thrive is an important feature in children with both syndromic and nonsyndromic paucity of interlobular bile ducts (PILBD). Thirteen children age 7 months-11 years with PILBD had pancreatic secretions in duodenal aspirate measured for 40 min after secretin-pancreozymin stimulation, six of these children had chronic diarrhoea. Studies were also performed in seven children age 2-12 years who presented with failure to thrive or nonspecific diarrhoea that subsequently resolved. The results of the control and the PILBD children were similar except in the six with chronic diarrhoea. These children had significant reductions in total volume of duodenal aspirate (p less than 0.05), bicarbonate concentration (p less than 0.02) and output (p less than 0.05), and in lipase concentrations (p less than 0.005). Five of these children have had a reduction in stool frequency and more rapid weight gain since receiving pancreatic supplementation. In children with PILBD and diarrhoea, pancreatic insufficiency may be a contributory factor to poor weight gain. These children may benefit from pancreatic extract supplementation.

Bile Ducts↗
PubMed1988

Ginseng--is there a use in clinical medicine?

Panax ginseng occupies an important place among the tonic remedies of Oriental medicine. Pharmacological investigations show that crude ginsenosides can increase non-specific resistance of an organism to various untoward influences. The effects of purified derived derivatives have only recently become better studied in immunological and cell growth studies in animals and in man. This has now provided some evidence to suggest that ginseng is a drug that contains many derivatives with different pharmacological properties, which could be useful in clinical medicine.

Animals↗
PubMed1987

Primary sclerosing cholangitis in childhood.

Thirteen children (8 female) with primary sclerosing cholangitis are described, in whom the diagnosis was confirmed by the presence of characteristic changes on endoscopic retrograde cholangiopancreatography. Nine had clinical features of chronic inflammatory bowel disease 1 mo to 5 yr before the onset of primary sclerosing cholangitis (6 patients) or appearing simultaneously with primary sclerosing cholangitis (3 patients). In 4 patients clinical evidence of chronic inflammatory bowel disease was absent but 1 of the 4 was found to have microscopic colitis in colonoscopic biopsy specimens. Biopsies were not performed in the remaining 3 patients. High immunoglobulin G concentrations and positive antinuclear or smooth muscle antibodies were present in all patients except 1 who had been given immunosuppressants. In 7 patients treated with immunosuppressants and followed up for 9 mo to 10 yr there was modest symptomatic improvement. This improvement was accompanied by a fall in transaminase levels in 6 of the patients and histologic improvement in 3 of 4 patients who had undergone biopsy. Greater use of endoscopic retrograde cholangiopancreatography in the last 6 yr led to the identification of 10 of these 13 cases, suggesting a higher incidence of primary sclerosing cholangitis in childhood than would appear from the literature.

Adolescent↗
PubMed1985

Histological diagnosis of chronic inflammatory bowel disease in childhood.

One hundred and four children were initially assessed by clinical, radiological, and endoscopic criteria as chronic inflammatory bowel disease. All were assessed independently using precise histological diagnostic criteria. Fifty eight patients were diagnosed as Crohn's disease, 25 as ulcerative colitis, 15 remained provisionally categorised as indeterminate colitis and six proved to be normal. Diagnostic granulomas were found in 36% of endoscopic biopsies from the 58 children with Crohn's disease. This appears to be an underestimate as only four of 14 children with granulomatous Crohn's disease operated on had granulomas on endoscopic biopsy. This study shows that there is a spectrum of histological appearances in endoscopic biopsies in chronic inflammatory bowel disease in childhood ranging from definite Crohn's disease to definite ulcerative colitis with indeterminate features in between. Accurate histological diagnosis of chronic inflammatory bowel disease is dependent upon either multiple endoscopic biopsies or assessment of a surgically resected specimen.

Adolescent↗
PubMed1984

Free erythrocyte protoporphyrin as an index of perinatal iron status.

The relationship between free erythrocyte protoporphyrin and conventional indices of iron status was studied in 49 mothers and their infants. Maternal venous blood samples were collected at 34 weeks gestation and at delivery. The corresponding infant blood samples were collected from the umbilical cord and at age 6 weeks. In each case free erythrocyte protoporphyrin, serum iron, total iron binding capacity, and serum ferritin were determined. Cord free erythrocyte protoporphyrin was negatively correlated with maternal ferritin at 34 weeks gestation (p = 0.016) and at delivery (p = 0.014), and with transferrin saturation at delivery (p = 0.026). The infants' haemoglobin concentrations at 6 weeks were significantly negatively related to maternal free erythrocyte protoporphyrin at 34 weeks (p = 0.026) and at delivery (p = 0.026). Cord free erythrocyte protoporphyrin is an index of maternal iron status in the last trimester. Maternal free erythrocyte protoporphyrin in the last trimester predicts the magnitude of physiological anaemia of the infant at age 6 weeks.

Adult↗