Themis Reverbel da Silveira

Soroprevalência para hepatite A e hepatite B em quatro centros no Brasil

The prevalence of antibodies to hepatitis A and B virus was assessed in 3,653 subjects across four regions of Brazil. The anti-HAV and anti-HBc seroprevalence were 64.7% and 7.9%, respectively. The highest anti-HAV (92.8%) and anti-HBc (21.4%) rates were seen in the Northern region. In other regions, anti-HAV seroprevalence over 90% was only reached in the more elderly, indicating an intermediate endemicity and a significantly higher anti-HAV prevalence was seen in the low socioeconomic group between 1-30 years. With respect to anti-HBc seroprevalence an increase was seen in adolescents and there was a significantly higher anti-HBc prevalence in the lower socioeconomic group between 1-20 years. A 3.1% anti-HBc prevalence was seen in one-year-old infants, suggesting a vertical transmission. The major findings of this study indicate that the pre-adolescent and adolescent population in some Brazilian cities are at greatest risk from both hepatitis A and B infection, but for different reasons.

Hepatitis B seroprevalence in Latin America

The seroprevalence of hepatitis B was investigated in over 12,000 subjects in six countries of Latin America: Argentina, Brazil, Chile, the Dominican Republic, Mexico, and Venezuela. Each study population was stratified according to age, gender, and socioeconomic status. Antibodies against hepatitis B core antigen (anti-HBc) were measured in order to determine hepatitis B infection. The highest overall seroprevalence was found in the Dominican Republic (21.4%), followed by Brazil (7.9%), Venezuela (3.2%), Argentina (2.1%), Mexico (1.4%), and Chile (0.6%). In all the countries an increase in seroprevalence was found among persons 16 years old and older, suggesting sexual transmission as the major route of infection. In addition, comparatively high seroprevalence levels were seen at an early age in the Dominican Republic and Brazil, implicating a vertical route of transmission.

Association between HLA and extrahepatic biliary atresia

The etiopathogenesis of extrahepatic biliary atresia (EHBA) remains undefined. There are clinical and pathological suggestions supporting the idea that EHBA could consist of at least two forms: the congenital (embryonic or fetal) and the acquired (perinatal) types. To test the hypothesis that susceptibility to this disease would be influenced by host genetic factors, we studied the human leukocyte antigen (HLA) system in 55 patients with and without major extrahepatic congenital anomalies. We found, especially in those without associated malformations, a significantly higher frequency of HLA-B12, of haplotypes A9-B5 and A28-B35, and of their disequilibrium values, as compared with the 8th International Histocompatibility Workshop controls. This study suggests that immunogenetic factors may play a role in determining susceptibility to EHBA, and the different HLA frequencies in those with and without anomalies lend support to the hypothesis that biliary atresia may be an etiologically heterogeneous disorder.

Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection in children and adolescents.

BACKGROUND & AIMS This multi-center study aimed to prospectively evaluate the safety and efficacy of a genotype-based Pegylated Interferon alfa-2a/Ribavirin therapy in treatment-naïve hepatitis C virus (HCV), positive HCV serology, and quantifiable HCV RNA, infected children. METHODS Eighteen children with genotypes 2 and 3 patients (group A) were assigned to medication for 24weeks, and 47 children with genotypes 1, 4, 5 and 6 patients (group B) for 48weeks. RESULTS Early response at week 12 was observed in 83% of group A patients and in 57% of group B patients (p<0.05). End of treatment response was achieved in 94% of patients in group A and in 57% in group B (p<0.001). Sustained virologic response was maintained in 89% of patients in group A and in 57% of patients in group B (p<0.01). Ten patients stopped prematurely the treatment, 2 for serious adverse event (acute hepatitis and thyrotoxicosis), and 8 because of no virologic response at week 24. Peginterferon alfa-2a and Ribavirin dose was adjusted in 15 patients (23%), 11 for neutropenia (17%), and 3 patients (5%), for anemia, respectively. Treatment-related adverse events included fever and flu-like symptoms (54%), irritability-depression-change of mood (34%), vomiting (23%), abdominal pain (38%), loss of appetite (21.5%) and dermatitis (29%). No influence on height growth was observed. CONCLUSIONS Pegylated inteferon alfa-2a and Ribavirin treatment allowed to achieve SVR in 57% of pediatric patients with genotypes 1, 4, 5 and 6, and in 94% of genotypes 2 and 3. These results show an improved SVR as compared to reference series in adults with similar regimen.

Total and Segmental Colonic Transit Time with Radio-opaque Markers in Adolescents with Functional Constipation

BACKGROUND In most instances, constipation is considered idiopathic or functional. The total and segmental colonic transit time, traced by radio- opaque markers, makes possible the identification of the colon segment that has the motility alteration that causes constipation. METHODS A study was performed of 13 adolescents, aged 12 to 18, with functional chronic constipation and 13 without constipation. In all of them the total and segmental colonic transit times were measured with radio-opaque markers. The adolescents ingested 20 markers each on three successive days, and on the fourth day a plain abdominal radiograph was performed. RESULTS In the nonconstipated adolescents the total colonic transit time (mean +/- SD) was 30.2 +/- 13.1 hours, in the right colon 5.7 +/- 3.9 hours, in the left colon 7.9 +/- 7.8 hours, and in the rectosigmoid 15.5 +/- 10.6 hours. In the constipated adolescents, the total colonic transit time was 58.3 +/- 17.4 hours, in the right colon 15.9 +/- 12.4 hours, in the left colon 14.7 +/- 13.4 hours, and in the rectosigmoid 17.2 +/- 16.2 hours. There was a statistically significant difference (p < 0.05) in the total colonic transit time, and in both the right and left colon transit times between constipated and nonconstipated adolescents. CONCLUSIONS The measurement of total and segmental colonic transit times is a simple method that allows one to distinguish constipation due to colonic dysfunction (right colon and left colon) from constipation due to distal obstruction (rectosigmoid).

Endoscopic nodular gastritis: an endoscopic indicator of high-grade bacterial colonization and severe gastritis in children with Helicobacter pylori.

Objective To investigate the significance of endoscopic nodular gastritis associated with Helicobacter pylori infection. Methods This prospective study included 185 children (50.8% boys) aged 1 to 12 years (mean, 6.9 ± 3.0 years) who underwent upper intestinal endoscopy during evaluation of chronic abdominal pain. The authors assessed the endoscopic appearance of the stomach, noting those patients with endoscopic nodular gastritis. Urease activity of gastric mucosal biopsies was measured. With histologic examination, the presence and density of H. pylori organisms, the presence of follicular gastritis, the nature of inflammation, and the gastritis activity grade and overall gastritis score were assessed. Results H. pylori infection was identified in 50 children (27%). Endoscopic nodular gastritis was significantly associated with active chronic gastritis and follicular gastritis. Nodularity in the stomach showed a high specificity (98.5%) and positive predictive value (91.7%) for the diagnosis of H. pylori infection and was observed in 22 of 50 (44%) H. pylori-positive patients and in 2 of 135 (1.5%) H. pylori-negative patients. A significant association was observed between older age and the prevalence of this finding (P < 0.001). There was a significant increase in endoscopic nodular gastritis with increased H. pylori density and a positive correlation (Pearson coefficient = 0.97) with increased gastritis score on histologic examination. Increase in gastritis score was dependent on increased H. pylori density in patients with gastric nodularity; this finding was independent of age. Conclusions Endoscopic findings of antral nodularity in children suggest the presence of H. pylori infection and follicular gastritis and may identify cases of severe gastritis and marked bacterial colonization.

Correlation between lactose absorption and the C/T-13910 and G/A-22018 mutations of the lactase-phlorizin hydrolase (LCT) gene in adult-type hypolactasia

The C/T-13910 mutation is the major factor responsible for the persistence of the lactase-phlorizin hydrolase (LCT) gene expression. Mutation G/A-22018 appears to be only in co-segregation with C/T-13910. The objective of the present study was to assess the presence of these two mutations in Brazilian individuals with and without lactose malabsorption diagnosed by the hydrogen breath test (HBT). Ten milk-tolerant and 10 milk-intolerant individuals underwent the HBT after oral ingestion of 50 g lactose (equivalent to 1 L of milk). Analyses for C/T-13910 and G/A-22018 mutations were performed using a PCR-based method. Primers were designed for this study based on the GenBank sequence. The CT/GA, CT/AA, and TT/AA genotypes (lactase persistence) were found in 10 individuals with negative HBT. The CC/GG genotype (lactase non-persistence) was found in 10 individuals, 9 of them with positive HBT results. There was a significant agreement between the presence of mutations in the LCT gene promoter and HBT results (kappa = -0.9, P < 0.001). The CT/AA genotype has not been described previously and seems to be related to lactase persistence. The present study showed a significant agreement between the occurrence of mutations G/A-22018 and C/T-13910 and lactose absorption in Brazilian subjects, suggesting that the molecular test used here could be proposed for the laboratory diagnosis of adult-type primary hypolactasia.

Avaliação nutricional de pacientes com cirrose pelo vírus da hepatite C: a aplicação da calorimetria indireta

BACKGROUND Malnutrition is frequent in cirrhotic patients, and its assessment is difficult. Functional assessment through a dynamometer is a simple method and could minimize these drawbacks. Harris-Benedict prediction formulae estimates the resting energy expenditure but has not been validated for this population. One alternative is the use of indirect calorimetry. AIM To assess nutritional status in cirrhotic patients and estimates the resting energy expenditure through indirect calorimetry and compares it to Harris-Benedict. PATIENTS AND METHODS Thirty four adult hepatitis C cirrhotic outpatients were studied, classified by Child-Pugh and model of end-stage liver disease score. The resting energy expenditure was predicted through Harris-Benedict and measured by indirect calorimetry. Nutritional assessment was done through anthropometry, subjective global assessment, hand-grip strength and a 3-day recall. RESULTS Fifteen (44.2%) were Child-Pug A, 12 (35.3%) B and 7 (20.6%) C, and 33 (97.1%) had model of end-stage liver disease scores less than 20. The resting energy expenditure predicted was higher than the measured (Harris-Benedict 1404.5 +/- 150.3 kcal; indirect calorimetry 1059.9 +/- 309.6 kcal). The prevalence of malnutrition varied between methods (body mass index, muscle arm circumference, subjective global assessment, triceps skinfold thickness and hand-grip strength: 0; 5.9; 17.6; 35.3 and 79.4%, accordingly). Calories and proteins intake were 80% and 85% of recommended amounts and there was inadequate intake of calcium, magnesium, iron and zinc. CONCLUSION Malnutrition was frequent and hand-grip strength seemed to be the most sensitive method for its diagnosis. Calories and protein intakes were inadequate. Considering that the predicted resting energy expenditure was higher than the measured one and the need to offer higher caloric intake, the use of the predicting equation may replace indirect calorimetry.BACKGROUND: Malnutrition is frequent in cirrhotic patients, and its assessment is difficult. Functional assessment through a dynamometer is a simple method and could minimize these drawbacks. Harris-Benedict prediction formulae estimates the resting energy expenditure but has not been validated for this population. One alternative is the use of indirect calorimetry. AIM: To assess nutritional status in cirrhotic patients and estimates the resting energy expenditure through indirect calorimetry and compares it to Harris-Benedict. PATIENTS AND METHODS: Thirty four adult hepatitis C cirrhotic outpatients were studied, classified by Child-Pugh and model of end-stage liver disease score. The resting energy expenditure was predicted through Harris-Benedict and measured by indirect calorimetry. Nutritional assessment was done through anthropometry, subjective global assessment, hand-grip strength and a 3-day recall. RESULTS: Fifteen (44.2%) were Child-Pug A, 12 (35.3%) B and 7 (20.6%) C, and 33 (97.1%) had model of end-stage liver disease scores less than 20. The resting energy expenditure predicted was higher than the measured (Harris-Benedict 1404.5 ± 150.3 kcal; indirect calorimetry 1059.9 ± 309.6 kcal). The prevalence of malnutrition varied between methods (body mass index, muscle arm circumference, subjective global assessment, triceps skinfold thickness and hand-grip strength: 0; 5.9; 17.6; 35.3 and 79.4%, accordingly). Calories and proteins intake were 80% and 85% of recommended amounts and there was inadequate intake of calcium, magnesium, iron and zinc. CONCLUSION: Malnutrition was frequent and hand-grip strength seemed to be the most sensitive method for its diagnosis. Calories and protein intakes were inadequate. Considering that the predicted resting energy expenditure was higher than the measured one and the need to offer higher caloric intake, the use of the predicting equation may replace indirect calorimetry.

Blood collection for biochemical analysis in adult zebrafish.

The zebrafish has been used as an animal model for studies of several human diseases. It can serve as a powerful preclinical platform for studies of molecular events and therapeutic strategies as well as for evaluating the physiological mechanisms of some pathologies. There are relatively few publications related to adult zebrafish physiology of organs and systems, which may lead researchers to infer that the basic techniques needed to allow the exploration of zebrafish systems are lacking. Hematologic biochemical values of zebrafish were first reported in 2003 by Murtha and colleagues who employed a blood collection technique first described by Jagadeeswaran and colleagues in 1999. Briefly, blood was collected via a micropipette tip through a lateral incision, approximately 0.3 cm in length, in the region of the dorsal aorta. Because of the minute dimensions involved, this is a high-precision technique requiring a highly skilled practitioner. The same technique was used by the same group in another publication in that same year. In 2010, Eames and colleagues assessed whole blood glucose levels in zebrafish. They gained access to the blood by performing decapitations with scissors and then inserting a heparinized microcapillary collection tube into the pectoral articulation. They mention difficulties with hemolysis that were solved with an appropriate storage temperature based on the work Kilpatrick et al. When attempting to use Jagadeeswarans technique in our laboratory, we found that it was difficult to make the incision in precisely the right place as not to allow a significant amount of blood to be lost before collection could be started. Recently, Gupta et al. described how to dissect adult zebrafish organs, Kinkle et al. described how to perform intraperitoneal injections, and Pugach et al. described how to perform retro-orbital injections. However, more work is needed to more fully explore basic techniques for research in zebrafish. The small size of zebrafish presents challenges for researchers using it as an experimental model. Furthermore, given this smallness of scale, it is important that simple techniques are developed to enable researchers to explore the advantages of the zebrafish model.

Immunogenicity and safety of hepatitis A vaccine in children with chronic liver disease.

Background Acute hepatitis A superimposed on chronic liver disease has been associated with a more severe course of disease and development of fulminant hepatitis. The aim of this study was to evaluate the immunogenicity and safety of an inactivated hepatitis A virus vaccine in children with chronic liver disease. Patients and Methods This was an open, prospective, and controlled trial with 89 anti-HAV negative children between 1 and 16 years of age studied at a pediatric liver disease and transplantation referral center. Inactivated HAV vaccine (Havrix), from GlaxoSmithKline Biologicals containing 720 Elisa units of alum-adsorbed hepatitis A antigen per 0.5 ml dose was used. Thirty-four pediatric patients with chronic liver disease (mean age: 7.0 ± 4.86 years) and 55 healthy controls (mean age: 4.8 ± 2.7 years) received two doses of Havrix vaccine in months zero and six. Seroconversion and anti-HAV titers expressed as geometric mean titers (GMT) in mIU/ml were measured at months one and seven, by a modified Hepatitis A virus andibodies (HAVAB) assay. Results Seroconversion rates at four weeks after primary immunization were 76% and 94% and the GMT 107.77 and 160.77 mIU/ml in the patient and control groups, respectively. One month after second dose the seroconversion rates were 97% and 100% in the groups with GMT of 812.40 and 2344.90 mIU/ml. Both doses were well tolerated with no significant adverse events observed. Local injection-site symptoms were the most common reactions reported in both groups. Conclusion Although GMTs were significantly lower in children with chronic liver disease compared to healthy controls, the overall seroconversion rates were not different. Hepatitis A virus vaccine was safe, well-tolerated, and immunogenic in children with chronic liver disease.