Wai-Tao Chan

Meta-analysis: the clinical features of the duodenal duplication cyst.

BACKGROUND Duplication cyst of the duodenum is rare. This study describes a case of duodenal duplication and evaluates its clinical features through a literature review. METHODS A case of duodenal duplication is reported, and related articles published from 1999 to 2009 on PubMed were reviewed. Clinical manifestations, diagnostic examinations, and methods of management were analyzed. RESULTS Including this report, there had been 38 citations in literature that provide adequate descriptions of 47 cases of duodenal duplication cysts. Nineteen (40.4%) were discovered before 10 years of age, whereas 10 (21.3%) were found in the second decade. The remaining 18 patients (38.3%) were older than 20 years. The case number decreased as age increased. Overall, 80% of cases presented with abdominal pain, and 53% were complicated with pancreatitis. CONCLUSIONS The most common symptom in duodenal duplication cysts is abdominal pain with or without nausea or vomiting. The most common complication is pancreatitis. Differential diagnoses of pancreatitis, hepatitis, cholestasis, or intussusception should include duplication cyst of the duodenum.

Genetic Variation in the Vascular Endothelial Growth Factor Gene is Associated With Biliary Atresia

Background and Goals: Biliary atresia (BA) is a chronic inflammatory disease of the bile ducts resulting in biliary cirrhosis. Vascular endothelial growth factor (VEGF) has been implicated in cell-mediated inflammatory reactions. We aimed to study the relationship between genetic variations of the VEGF gene and susceptibility to BA using both case-control and family-based methodologies. Study: A total of 45 Taiwanese children with BA, 160 ethnically matched healthy controls, and 40 families (consisting of parents, affected children, and unaffected siblings) were studied. Three functional VEGF polymorphisms (−2578 A/C, −634 G/C, and +936 C/T) were assessed by using TaqMan assay. Results: The +936 CC genotype [odds ratio (OR) 3.51, 95% confidence interval 1.54-8.01, Pc=0.006] and C allele (OR 3.19, 95% confidence interval 1.48-6.90, Pc=0.004) were significantly associated with increased risk of BA. The association of the +936 C allele with BA was also confirmed in a family-based association study (OR 5.7, χ2=9.8, Pc=0.005). None of the haplotypes studied significantly influenced the risk to BA in either the case-control or family data sets. Conclusions: The VEGF +936 C/T polymorphism and particularly the C allele are associated with BA, possibly conferring increased susceptibility to the disease.

Vertical transmission of hepatitis C virus: Current knowledge and perspectives

Hepatitis C virus (HCV) infection is a major global health issue. Infection by the HCV can cause acute and chronic liver diseases and may lead to cirrhosis, hepatocellular carcinoma or liver failure. The World Health Organization estimates that approximately 3% of the world population have been infected with HCV and the worldwide prevalence is between 1% and 8% in pregnant women and between 0.05% and 5% in children. Following the introduction of blood product screening, vertical transmission becomes the leading cause of childhood HCV infection. The prevalence of pediatric HCV infection varies from 0.05% to 0.36% in developed countries and between 1.8% and 5% in the developing world. All children born to women with anti-HCV antibodies should be checked for HCV infection. Though universal screening is controversial, selective antenatal HCV screening on high-risk populations is highly recommended and should be tested probably. Multiple risk factors were shown to increase the possibility of HCV vertical transmission, including coinfections with human immunodeficiency virus, intravenous drug use and elevated maternal HCV viral load, while breastfeeding and HCV genotypes have been studied to have little impact. At present, no clinical intervention has been clearly studied and proved to reduce the HCV vertical transmission risk. Cesarean section should not be recommended as a procedure to prevent vertical transmission, however, breastfeeding is generally not forbidden. The high prevalence of global HCV infection necessitates renewed efforts in primary prevention, including vaccine development, as well as new approaches to reduce the burden of chronic liver disease. Future researches should focus on the interruption of vertical transmission, developments of HCV vaccine and direct-acting antivirals in infancy and early childhood.

A Twenty-year Review of Early and Late-presenting Congenital Bochdalek Diaphragmatic Hernia: Are They Different Clinical Spectra?

BACKGROUND Congenital Bochdalek diaphragmatic hernia (CDH) is easily recognized if it is present shortly after birth. However, cases of delayed CDH presentation are more subtle and therefore less easily diagnosed. METHODS We retrospectively analyzed 85 patients who were under 18 and diagnosed with CDH between June 1987 and May 2007. Those diagnosed before 1 month of age were categorized as having early-presenting CDH and those diagnosed after 1 month were categorized as having late-presenting CDH. RESULTS Of the 85 cases, 68 (80%) were early-presenting and 17 (20%) were late-presenting CDH. Respiratory symptoms were more common in early-presenting CDH, while gastrointestinal complaints were more dominant in the late-presenting group, particularly in patients with left diaphragmatic defects. Late-presenting CDH, which was more likely to be associated with chronic gastrointestinal symptoms, was associated with a lower mortality than acute early-presenting CDH with respiratory symptoms, despite the more prompt diagnosis of the latter. The small bowel was the organ most commonly herniated into the thorax. Congenital heart disease was the most commonly associated malformation, but the presence of associated anomalies did not increase mortality. CONCLUSION Early-presenting CDH shows acute symptoms, is readily diagnosed, and requires prompt intervention to prevent death. In contrast, late-presenting CDH shows more subtle symptoms and is more difficult to diagnose. Although the late-presenting CHD has better prognosis, it still requires surgery intervention to alleviate the symptoms. Clinicians must maintain a high index of suspicion for CDH, regardless of its presentation.

In Vitro Prevention of Salmonella Lipopolysaccharide-Induced Damages in Epithelial Barrier Function by Various Lactobacillus Strains

Background. Lactobacillus shows beneficial anti-inflammatory effects on Salmonella infection. The maintenance of the tight junction (TJ) integrity plays an importance role in avoiding bacterial invasion. Whether Lactobacillus could be used to regulate the TJ protein expression and distribution in inflamed intestinal epithelial cells was determined. Methods. Using the transwell coculture model, Salmonella lipopolysaccharide (LPS) was apically added to polarized Caco-2 cells cocultured with peripheral blood mononuclear cells in the basolateral compartment. LPS-stimulated Caco-2 cells were incubated with various Lactobacillus strains. TJ integrity was determined by measuring transepithelial electrical resistance across Caco-2 monolayer. Expression and localization of TJ proteins (zonula-occludens- (ZO-) 1) were determined by Western blot and immunofluorescence microscopy. Results. Various strains of Lactobacillus were responsible for the different modulations of cell layer integrity. LPS was specifically able to disrupt epithelial barrier and change the location of ZO-1. Our data demonstrate that Lactobacillus could attenuate the barrier disruption of intestinal epithelial cells caused by Salmonella LPS administration. We showed that Lactobacillus strains are associated with the maintenance of the tight junction integrity and appearance. Conclusion. In this study we provide insight that live probiotics could improve epithelial barrier properties and this may explain the potential mechanism behind their beneficial effect in vivo.

Clinical Manifestations, Laboratory Findings and Complications of Pediatric Scrub Typhus in Eastern Taiwan

BACKGROUND Scrub typhus is a clinically important endemic disease in Taiwan. The aims of this study were to analyze the clinical manifestations, laboratory data and complications of pediatric scrub typhus in eastern Taiwan. PATIENTS AND METHODS We searched medical records for all patients with scrub typhus who were hospitalized between 1992 and 2002 at the Taitung branch of Mackay Memorial Hospital, Taiwan. Records of children under the age of 18 with a confirmed diagnosis were selected for retrospective review. RESULTS During the study period, 145 patients fulfilled the diagnostic criteria for scrub typhus, of whom 106 (73%) were adults and 39 (27%) were children. The mean age of the children was 7.6+/-4.6 years. The most common clinical manifestations of pediatric scrub typhus were fever (n=39; 100%), cough (n=28; 72%), anorexia (72%), eschar (69%), chill (67%) and lymphadenopathy (64%). The most common complications were hepatic dysfunction (77%) and pneumonitis (54%). Three children (8%) required intensive care, but the overall survival rate was 97%. One child died with multi-organ failure within 8 hours after admission. CONCLUSION Scrub typhus should be considered in children with fever and hepatic dysfunction, particularly in those with a history of environmental exposure in an endemic area for scrub typhus. The presence of an eschar offers an important diagnostic clue, but not for all cases. Children with scrub typhus may develop serious complications and may even die if appropriate treatment is not given. Doxycycline is an effective antibiotic for pediatric scrub typhus in Taiwan.

Intestinal Angiodysplasia: An Uncommon Cause of Gastrointestinal Bleeding in Children

BACKGROUND Angiodysplasia of the gastrointestinal (GI) tract is recognized as an important cause of lower GI bleeding in elderly. It usually involves the cecum and right colon in adults. Unlike the adult group, there has been little experience with the pediatric population. METHODS From July 2004 to October 2008, patients presenting at the Mackay Memorial Hospital with GI hemorrhage diagnosed as angiodysplasia by helical computed tomographic angiography were reviewed. RESULTS Eighteen patients (14 boys and 4 girls) with mean age of 7.1 years (range, 1 month to 17 years) were diagnosed. The time from initial clinical onset to diagnosis of angiodysplasia ranged from 1 week to 11 years, most around 1-2 weeks. All patients except one had anemia and an average hemoglobin level of 7.9 ± 2.1g/dL. The most commonly involved areas were ascending colon and terminal ileum. Four patients received surgery treatment with resection of affected segments. CONCLUSIONS In pediatric patients, angiodysplasia is a rare cause of GI bleeding and may be delayed in diagnosis. This diagnosis should be considered when patients have recurrent GI bleeding. In this study, the final surgical and pathological diagnosis was made in 6 of 18 patients. In six patients, computed tomographic angiography had 66% diagnostic accuracy for angiodysplasia (four of six patients who received operation were compatible with angiodysplasia by confirmation of histology).

Association of polymorphisms in the Interleukin-18 gene with susceptibility to biliary atresia.

Background and Objective:Biliary atresia (BA) is a destructive inflammatory obliterative cholangiopathy of neonates that affects both intrahepatic and extrahepatic bile ducts. Although the etiology is unknown, immunologically mediated injury of the bile ducts triggered by as yet unidentified infectious agents is likely to play a critical role. Interleukin-18 (IL-18) is a proinflammatory cytokine that plays an important role in immune, infectious, and inflammatory diseases because of its induction of interferon-gamma. In this study, we investigated whether polymorphisms of the IL18 gene were associated with susceptibility to BA. Patients and Methods:Genomic DNA was extracted from whole-blood samples of 50 Taiwanese children with BA and 1117 ethnically matched healthy controls. The IL18 –1297 T/C, –607 C/A, –137 G/C, and +105 A/C polymorphisms were genotyped using the TaqMan assay. Results:No statistically significant differences of genotype, allele, carrier, and haplotype frequencies of these IL18 gene variants were found between children with BA and healthy controls. Conclusions:Our data suggest that the IL18 gene does not play a major role in BA predisposition in Taiwanese children.

Association of Interferon-Gamma Gene Polymorphisms in Taiwanese Children with Biliary Atresia

BackgroundBiliary atresia (BA) is a devastating neonatal hepatobiliary disease characterized by bile duct inflammation and fibrosis. The pathogenesis remains unclear, but immunologically mediated injury to bile ducts following an infectious insult is likely to play a critical role. Interferon-gamma (IFN-γ) is a key cytokine that affects immune-mediated inflammatory responses.ObjectiveThis study aims to investigate whether polymorphisms of the IFN-γ (IFNG) gene were associated with susceptibility to BA.MethodsThe IFNG −1615 C/T, −183 G/T, +874 A/T, and +2197 A/G polymorphisms were genotyped using the TaqMan assay, and CA repeat microsatellite was analyzed using capillary electrophoresis in 50 children with BA and 788 ethnically matched healthy controls.ResultsThe distribution of genotype, allele, and haplotype frequencies of these IFNG gene variants did not differ significantly between children with BA and controls.ConclusionPolymorphisms of the IFNG gene do not appear to play a major role in the genetic predisposition to BA in Taiwanese children.

Meckel’s Diverticulum: Factors Associated with Clinical Manifestations

Objectives. The purpose of this study was to investigate the clinical features of Meckels diverticula at different ages, genders, and pathology in order to serve as a reminder to clinicians when evaluating potential cases and to help obtain an early diagnosis. Methods. We collected information of patients with Meckels diverticulum diagnosed at Mackay Memorial Hospital in Taiwan from 1984 to 2009. After performing a thorough review of their charts, the clinical features of the Meckels diverticula were analyzed according to age groups, gender, and pathology. Result. A total of 126 patients, with 90 males and 36 females, were enrolled in this study. Seventy-five patients were symptomatic and 51 Meckels diverticula were found incidentally during surgery for other diseases. Among symptomatic patients, 39% of pediatric patients and 5% of adult patients had intestinal hemorrhage. Twenty-eight percent of pediatric patients and 67% of adult patients had inflammation of Meckels diverticulum. Forty-six percent of males and 16% of females had inflammation. Conversely, 27% of males and 58% percent of females had intestinal obstruction. When Meckels diverticulum had ectopic gastric mucosa, it tended to cause intestinal hemorrhage when the patient is young. Conclusions. Age, gender, and pathology affect the clinical presentations of Meckels diverticula.