Effect of a Brazilian regional basic diet on the prevalence of caries in rats

The aim of the present study was to determine the effect of a regional basic diet (RBD) on the prevalence of caries in the molar teeth of rats of both sexes aged 23 days. The animals were divided into six groups of 10 rats each receiving the following diets for 30 and 60 days after weaning: RBD, a cariogenic diet, and a commercial diet. The prevalence and penetration of caries in the molar teeth of the rats was then analyzed. The RBD produced caries in 37.5% of the teeth of animals fed 30 days, and in 83.4% of animals fed 60 days, while the cariogenic diet produced caries in 72.5% and 77.5% of the teeth of animals fed 30 and 60 days, respectively. Rats fed the RBD for 30 days had caries in the enamel in 38% of their teeth, 48% had superficial dentin caries, and 7.5% moderate dentin caries. The effect of the RBD did not differ significantly from that of the cariogenic diet in terms of the presence of caries in rats fed 60 days. The penetration depth of the caries produced by the RBD was the same as that produced by the cariogenic diet. Our results show that the RBD has the same cariogenic potential as the cariogenic diet. Since the RBD is the only option for the low-income population, there should be a study of how to compensate for the cariogenicity of this diet.

Ultrasonographic determination of goiter prevalence in southern Brazilian schoolchildren

The aim of the present study was to estimate the prevalence of goiter in schoolchildren in a formerly iodine-deficient region in southern Brazil by assessing the relationship between body surface area (m²) and thyroid volume (ml) measured by ultrasonography. A population-based sample of 1,094 randomly selected schoolchildren (6 to 14 years; 556 boys and 538 girls) underwent clinical evaluation. A total of 119 (10.9%) children were diagnosed with goiter upon clinical examination according to WHO criteria (grade Ia: 65, grade Ib: 24, grade II: 29, grade III: 1). Of these, 85 underwent ultrasonography. In order to ascertain the absence of goiter in the 975 schoolchildren with a negative result upon clinical examination, one of ten children was randomly selected for ultrasonography. Sixty-two children agreed to be submitted to the exam. Thus, 147 schoolchildren were evaluated by ultrasonography (7.5-MHz transducer). Goiter was considered to be present when the thyroid volume:body surface area index was >6.2 ml/m². The estimated prevalence of goiter if all schoolchildren had been submitted to thyroid volume measurement by ultrasound was 7.2%; it was higher in the lower socioeconomic class (8.2%) than in the upper (7.8%) and middle classes (6.5%). In conclusion, the prevalence of goiter in schoolchildren of this region was higher than in other iodine-sufficient areas, especially in lower socioeconomic classes. Goiter in this region may be associated with naturally occurring goitrogens that operate more intensively among less privileged individuals.

Prevalence of diarrheogenic Escherichia coli and rotavirus among children from Botucatu, São Paulo State, Brazil

In a one-year prospective study carried out to define the role of rotavirus and Escherichia coli in local childhood diarrhea, we determined the prevalence of both agents in 54 diarrheic children attending a health center in Botucatu. Diarrheogenic E. coli (DEC) strains were characterized by O:H serotyping, a search for virulence genetic markers, and assays of adherence to HEp-2 cells. Except for enteroaggregative E. coli (EAEC), no other DEC category was detected in the children's stools. Both EAEC and rotavirus were isolated from 22 of the 54 (41.0%) diarrheic children as single agents or in combination with other enteropathogens. However, when considering the presence of a single agent, EAEC was dominant and isolated from 20.4% of the patients, whereas rotavirus was detected in 14.8%. These results indicate that rotavirus and EAEC play a significant role as agents of childhood diarrhea in the local population.

Prevalence of Y chromosome deletions in a Brazilian population of nonobstructive azoospermic and severely oligozoospermic men

We determined the prevalence of Y chromosome deletions in a population of 60 Brazilian nonobstructive azoospermic and severely oligozoospermic men. PCR-based screening of microdeletions was performed on lymphocyte DNA for the presence of 14 sequence-tagged sites (STS) located in the azoospermic factor (AZF) on the Yq chromosome. All STS were amplified efficiently in samples from 12 fertile men tested, but failed to be amplified in samples from fertile women, indicating the specificity of PCR conditions for Yq screening. Overall, 4 of the 60 infertile patients tested (6.7%) exhibited deletion of the Y chromosome, 2 of them being severely oligozoospermic patients (P10 and P32) and 2 azoospermic men (patients P47 and P57). Patients P47 and P57 presented larger deletions in the AZFa, AZFb and AZFc subregions, with apparent loss of Yq material evidenced by karyotype analysis. Patients P10 and P32 presented deletions confined to the AZFc region, involving the DAZ locus. Male relatives of patients P10 and P32 had no Y chromosome deletions and presented a normal karyotype, suggesting a de novo status of the deletions found. Our data add to the growing literature showing that microdeletions of the Y chromosome can be the cause of male idiopathic infertility.

Prevalence of celiac disease in Brazilian children of short stature

The aim of the present study was to determine the prevalence of celiac disease in children of short stature and to assess whether some of the routine laboratory examinations performed to determine the cause of short stature could suggest the presence of celiac disease. A total of 106 children of short stature and no gastrointestinal symptoms were studied. An extensive endocrine work-up had been negative for all of them and an additional investigation was performed by measuring the concentration of antiendomysial antibody. Patients who were positive for antiendomysial antibody ( > or = 1:10) or who exhibited IgA deficiency (less than 5 mg/dl) were referred for an endoscopic intestinal biopsy. We detected a pathological titer of antiendomysial IgA in six of these patients. Five of them showed histological abnormalities compatible with celiac disease and one had normal histology and was considered to have potential celiac disease. The prevalence of celiac disease in the population studied was 4.7% (with another 0.9% of the subjects being considered to have potential celiac disease). The children with celiac disease did not differ in any of the parameters tested when compared to those without celiac disease, though they showed an improvement in growth velocity after treatment with a gluten-free diet. We conclude that it is important to test all children with short stature for celiac disease by measuring antiendomysial IgA.

Prevalence of antibodies to human herpesvirus-8 in populations with and without risk for infection in São Paulo State

Human herpesvirus 8 (HHV-8) is a newly described herpesvirus that is etiologically associated with all forms of Kaposi's sarcoma (KS). Seroepidemiological studies have shown high prevalence rates of HHV-8 antibodies among men who have sex with men (MSM) and AIDS patients, African children, Brazilian Amerindians, and elderly individuals in certain regions of Europe. The aim of the present study was to determine the prevalence of HHV-8 antibodies in healthy children and young adults from different cities in São Paulo State, and in a population at high risk for HHV-8 infection: HIV-negative MSM, and AIDS patients with and without KS. Antibodies to HHV-8 latency-associated nuclear antigen and lytic-phase antigens were detected by immunofluorescence assays. In 643 healthy children and young adults from the general population attending a vaccination program for yellow fever in ten different cities in São Paulo State, the prevalence of HHV-8 antibodies detected by the presence of latent or lytic antigens ranged from 1.0 to 4.1% in the different age groups (mean = 2.5%). In the MSM group, the prevalence was 31/95 (32.6%). In the group of patients with AIDS, the prevalence was 39.2% (51/130) for non-KS patients and 98.7% (77/78) for AIDS patients with the diagnosis of KS confirmed by histopathological examination. We conclude that HHV-8 has a restricted circulation among healthy children and young adults in the general population of São Paulo State and a high prevalence among MSM and AIDS patients.

The size and prevalence of the cavum septum pellucidum are normal in subjects with panic disorder

Panic disorder is thought to involve dysfunction in the septohippocampal system, and the presence of a cavum septum pellucidum might indicate the aberrant development of this system. We compared the prevalence and size of cavum septum pellucidum in 21 patients with panic disorder and in 21 healthy controls by magnetic resonance imaging. The length of the cavum septum pellucidum was measured by counting the number of consecutive 1-mm coronal slices in which it appeared. A cavum septum pellucidum of >6 mm in length was rated as large. There was no significant difference in the proportion of patients (16 of 21 or 76.2%) and controls (18 of 21 or 85.7%) with a cavum septum pellucidum (P = 0.35, Fisher's exact test, one-tailed), and no members of either group had a large cavum septum pellucidum. The mean cavum septum pellucidum rating in the patient and control groups was 1.81 (SD = 1.50) and 2.09 (SD = 1.51), respectively. There were also no significant differences between groups when we analyzed cavum septum pellucidum ratings as a continuous variable (U = 196.5; P = 0.54). Across all subjects there was a trend towards a higher prevalence of cavum septum pellucidum in males (100%, 10 of 10) than females (75%, 24 of 32; P = 0.09, Fisher's exact test, one-tailed). Thus, we conclude that, while panic disorder may involve septo-hippocampal dysfunction, it is not associated with an increased prevalence or size of the cavum septum pellucidum.

Relationship between the prevalence of anti-glutamic acid decarboxylase autoantibodies and duration of type 1 diabetes mellitus in Brazilian patients

The objective of the present study was to determine whether the duration of disease has any influence on the prevalence of glutamic acid decarboxylase autoantibodies (GADA) in Brazilian patients with type 1 diabetes (T1D) and variable disease duration. We evaluated 83 patients with T1D. All participants were interviewed and blood was obtained for GADA measurement by a commercial radioimmunoassay (RSR Limited, Cardiff, UK). Four groups of patients were established according to disease duration: A) 1-5 years of disease (N = 24), B) 6-10 years of disease (N = 19), C) 11-15 years of disease (N = 25), and D) >15 years of disease (N = 15). GADA prevalence and its titers were determined in each group. GADA was positive in 38 patients (45.8%) and its frequency did not differ between the groups. The prevalence was 11/24 (45.8%), 8/19 (42.1%), 13/25 (52%), and 6/15 (40%) in groups A, B, C, and D, respectively (P = 0.874). Mean GADA titer was 12.54 ± 11.33 U/ml for the sample as a whole and 11.95 ± 11.8, 12.85 ± 12.07, 10.57 ± 8.35, and 17.45 ± 16.1 U/ml for groups A, B, C, and D, respectively (P = 0.686). Sex, age at diagnosis or ethnic background had no significant effect on GADA (+) frequency. In conclusion, in this transversal study, duration of disease did not affect significantly the prevalence of GADA or its titers in patients with T1D after one year of diagnosis. This was the first study to report this finding in the Brazilian population.

Prevalence of deltaF508, G551D, G542X, and R553X mutations among cystic fibrosis patients in the North of Brazil

Cystic fibrosis (CF) is the most common genetic disease among Caucasians and is rare among sub-Saharan Africans. The Brazilian population is not ethnically homogeneous but it is the result of three-way ethnic admixture of Europeans, Africans and Amerindians in varying proportions, depending on the region. In the present study, we investigated 33 patients who had been diagnosed and are currently under treatment for CF at the University Hospital João de Barros Barreto, Belém, Pará State. The molecular analysis for G542X, G551D and R553X mutations was performed by PCR followed by RFLP using BstNI, HincII and MboI, respectively, in polyacrylamide gel eletrophoresis and stained with AgNO3. ThedeltaF508 mutation (a deletion of 3 bp) was only analyzed by polyacrylamide gel electrophoresis and stained with AgNO3. Each sample was analyzed for regions of interest in the CFTR gene using amplified by PCR and specific primers. The deltaF508 and G551D mutations presented frequencies of 22.7 and 3%, respectively. In 74.3% of the remaining patients, none of the mutations investigated was found. The present study characterized in a sample of patients with an established clinical diagnosis of CF (asthma, repeated bronchopneumonia, disorders of nutritional status, etc.) the most frequent mutation ( deltaF508) in the North region of Brazil and is also the first report of the G551D mutation. In spite of the wide spectrum of CF mutations and the heterogeneous ethnic origin of the Amazon population, the molecular diagnosis is a helpful additional tool for the diagnosis and treatment of CF patients.

Prevalence of retinopathy in Caucasian type 2 diabetic patients from the South of Brazil and relationship with clinical and metabolic factors

Diabetic retinopathy (DR) is a sight-threatening chronic complication of diabetes mellitus and is the leading cause of acquired blindness in adults. In this cross-sectional study, we investigated the prevalence of and the factors associated with DR in an analysis of 210 consecutive and unrelated Brazilian Caucasians with type 2 diabetes mellitus. Retinopathy was evaluated by ophthalmoscopy and/or biomicroscopy through dilated pupils. The relationship between clinical and metabolic variables and the presence of DR was assessed by logistic regression analysis. DR was detected in 99 of the 210 patients (47%). In the univariate logistic regression analyses, male sex, duration of diabetes, body mass index, glycated hemoglobin, C-peptide, LDL cholesterol, smoking, and albumin excretion rate were found to be associated with the presence of DR. However, the multiple logistic regression analysis showed that only duration of diabetes (odds ratio (OR) = 1.15, 95% CI = 1.09-1.22; P < 0.001), glycated hemoglobin (OR = 1.21, 95% CI = 1.01-1.46; P = 0.047) and albumin excretion rate >100 µg/min (OR = 12.72, 95% CI = 3.89-41.56; P < 0.001) were independently associated with DR. Although DR was found to be frequent among Brazilian type 2 diabetic patients, its prevalence was within the range observed in other Caucasian populations. Our findings emphasize the need for good glycemic control in order to prevent or delay the onset of DR, since the most well-known risk factors for the development of this complication in type 2 diabetes mellitus, such as duration of diabetes, glycated hemoglobin and albumin excretion rate were independently related to DR.

Prevalence of low trauma fractures in long-term kidney transplant patients with preserved renal function

We evaluated the prevalence of low bone mineral density (BMD) and osteoporotic fractures in kidney transplantation (KT) patients and determined risk factors associated with osteoporotic fractures. The study was conducted on 191 patients (94 men and 97 women) with first KT for 3 years or more presenting stable and preserved renal function (serum creatinine levels lower than 2.5 mg/dl). KT patients were on immunosuppressive therapy and the cumulative doses of these drugs were also evaluated. BMD was determined by dual-energy X-ray absorptiometry at multiple sites (spine, femur and total body). Quantitative ultrasound of the calcaneus (broadband ultrasound attenuation, speed of sound, and stiffness index, SI) was also performed. Twenty-four percent (46) of all patients had either vertebral (29/46) or appendicular (17/46) fractures. We found osteoporosis and osteopenia in 8.5-13.4 and 30.9-35.1% of KT patients, respectively. Women had more fractures than men. In women, prevalent fractures were associated with diabetes mellitus [OR = 11.5, 95% CI (2.4-55.7)], time since menopause [OR = 3.7, 95% CI (1.2-11.9)], femoral neck BMD [OR = 1.99, 95% CI (1.4-2.8)], cumulative dose of steroids [OR = 1.1, 95% CI (1.02-1.12)] and low SI [OR = 1.1, 95% CI (1.0-1.2)]. In men, fractures were associated with lower lumbar spine BMD [OR = 1.75, 95% CI (1.1-2.7)], lower SI [OR = 1.1, 95% CI (1.03-1.13)], duration of dialysis [OR = 1.3, 95% CI (1.13-2.7)], and lower body mass index [OR = 1.24, 95% CI (1.1-1.4). Our results demonstrate high prevalence of low BMD and osteoporotic fractures in patients receiving a successful kidney transplant and indicate the need for specific intervention to prevent osteoporosis in this population.

Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients

Mitochondrial mutations are responsible for at least 1% of the cases of hereditary deafness, but the contribution of each mutation has not yet been defined in African-derived or native American genetic backgrounds. A total of 203 unselected hearing-impaired patients were screened for the presence of the mitochondrial mutation A1555G in the 12S rRNA gene and mutations in the tRNA Ser(UCN) gene in order to assess their frequency in the ethnically admixed Brazilian population. We found four individuals with A1555G mutation (2%), which is a frequency similar to those reported for European-derived populations in unselected samples. On the other hand, complete sequencing of the tRNA Ser(UCN) did not reveal reported pathogenic substitutions, namely A7445G, 7472insC, T7510C, or T7511C. Instead, other rare substitutions were found such as T1291C, A7569G, and G7444A. To evaluate the significance of these findings, 110 "European-Brazilians" and 190 "African-Brazilians" unrelated hearing controls were screened. The T1291C, A7569G and G7444A substitutions were each found in about 1% (2/190) of individuals of African ancestry, suggesting that they are probably polymorphic. Our results indicate that screening for the A1555G mutation is recommended among all Brazilian deaf patients, while testing for mutations in the tRNA Ser(UCN) gene should be considered only when other frequent deafness-causing mutations have been excluded or in the presence of a maternal transmission pattern.

Prevalence of hepatitis C virus (HCV) infection and HCV genotypes of hemodialysis patients in Salvador, Northeastern Brazil

Hepatitis C virus (HCV) infection has been identified as the major cause of chronic liver disease among patients on chronic hemodialysis (HD), despite the important reduction in risks obtained by testing candidate blood donors for anti-HCV antibodies and the use of recombinant erythropoietin to treat anemia. A cross-sectional study was performed to estimate the prevalence of HCV infection and genotypes among HD patients in Salvador, Northeastern Brazil. Anti-HCV seroprevalence was determined by ELISA in 1243 HD patients from all ten different dialysis centers of the city. HCV infection was confirmed by RT-PCR and genotyping was performed by restriction fragment length polymorphism. Anti-HCV seroprevalence among HD patients was 10.5% (95% CI: 8.8-12.3) (Murex anti-HCV, Abbott Murex, Chicago, IL, USA). Blood samples for qualitative HCV detection and genotyping were collected from 125/130 seropositive HD patients (96.2%). HCV-RNA was detected in 92/125 (73.6%) of the anti-HCV-positive patients. HCV genotype 1 (77.9%) was the most prevalent, followed by genotype 3 (10.5%) and genotype 2 (4.6%). Mixed infections of genotypes 1 and 3 were found in 7.0% of the total number of patients. The present results indicate a significant decrease in anti-HCV prevalence from 23.8% detected in a study carried out in 1994 to 10.5% in the present study. The HCV genotype distribution was closely similar to that observed in other hemodialysis populations in Brazil, in local candidate blood donors and in other groups at risk of transfusion-transmitted infection.

Prevalence of serological markers of hepatitis B virus in pregnant women from Paraná State, Brazil

The prevalence of hepatitis B virus (HBV) in Brazil increases from South to North but moderate to elevated prevalence has been detected in the Southwest of Paraná State. The prevalence of serological markers of HBV was evaluated in 3188 pregnant women from different counties in Paraná State and relevant epidemiological features were described. The prevalence of HBV markers in pregnant women for the state as a whole was 18.5% (95% CI = 17.2-19.9), ranging from 7.2% in Curitiba to 38.5% in Francisco Beltrão. The endemicity of HBV marker prevalence in pregnant women was intermediate in Cascavel, Foz do Iguaçu, and Francisco Beltrão, and low in Curitiba, Londrina, Maringá, and Paranaguá. Multiple logistic regression showed that HBV marker prevalence increased with age, was higher among black women, among women of Italian and German descent, and among women who had family members in neighboring Rio Grande do Sul State. Univariate analysis showed that HBV marker prevalence was also higher among women with no education or only primary education, with a lower family income and whose families originated from the South Region of Brazil. Pregnant women not having positive HBV markers (anti-HBc, HBsAg or anti-HBs detected by ELISA) corresponded to 73.7% of the population studied, implying that HBV vaccination needs to be reinforced in Paraná State. The highest prevalence was found in three counties that received the largest number of families from Santa Catarina and Rio Grande do Sul, where most immigrants were of German or Italian ascendance. This finding probably indicates that immigrants that came to this area brought HBV infection to Southwestern Paraná State.

Prevalence of diphtheria and tetanus antibodies and circulation of Corynebacterium diphtheriae in São Paulo, Brazil

The introduction of routine vaccination against tetanus and diphtheria in Brazil has decreased the incidence and changed the epidemiology of both diseases. We then investigated the prevalence of Corynebacterium diphtheriae carrier status and diphtheria and tetanus immunity in São Paulo, Brazil. From November 2001 to March 2003, 374 individuals were tested for the presence of C. diphtheriae in the naso-oropharynx and of serum diphtheria and tetanus antibodies. Participants were all healthy individuals without acute or chronic pathologies and they were stratified by age as follows: 0-12 months and 1-4, 5-9, 10-14, 15-24, 25-39, 40-59, and ³60 years. Antibodies were assessed using a double-antigen ELISA. C. diphtheriae species were identified by biochemical analysis and toxigenicity was assessed by the Elek test. For diphtheria, full protection (antibodies ³0.1 IU/mL) was present in 84% of the individuals, 15% had basic protection (antibodies ³0.01 and <0.1 IU/mL) and 1% were susceptible (antibodies <0.01 IU/mL). Full tetanus protection (antibodies ³0.1 IU/mL) was present in 79% of the participants, 18% had basic protection (antibodies ³0.01 and <0.1 IU/mL) and 3% were susceptible (antibodies <0.01 IU/mL). The geometric mean of diphtheria and tetanus antibodies reached the highest values at 5-9 years and decreased until the 40-59-year age range, increasing again in individuals over 60 years. Three participants (0.8%) were carriers of C. diphtheriae, all non-toxigenic strains. The present results demonstrate the clear need of periodic booster for tetanus and diphtheria vaccine in adolescents and adults after primary immunization in childhood.