Yanna Karla de Medeiros Nóbrega

Autism spectrum disorder and celiac disease: no evidence for a link

OBJECTIVE To evaluate the possible association between celiac disease (CD) and/or gluten sensitivity (GS) and autism spectrum disorder (ASD). METHODS Occurrences of CD were determined in a group of children and adolescents affected by ASD and, conversely, occurrences of ASD were assessed in a group of biopsy-proven celiac patients. To detect the possible existence of GS, the levels of antigliadin antibodies in ASD patients were assessed and compared with the levels in a group of non-celiac children. RESULTS The prevalence of CD or GS in ASD patients was not greater than in groups originating from the same geographical area. Similarly the prevalence of ASD was not greater than in a group of biopsy-proven CD patients. CONCLUSION No statistically demonstrable association was found between CD or GS and ASD. Consequently, routine screening for CD or GS in all patients with ASD is, at this moment, neither justified nor cost-effective.

Is the prevalence of celiac disease increased among epileptic patients

OBJECTIVE To assess the prevalence of celiac disease (CD) among a group of epileptic patients attending the Epilepsy Clinics of two general hospitals in the city of Brasilia (DF), Brazil. METHOD Serum samples were collected from 255 epileptic patients (119 children, 136 adults) originating from Epilepsy Clinics, and from a control group composed by 4405 individuals (2034 children, 2371 adults) attending the Laboratory of Clinical Analysis, for routine blood testing. The diagnosis of CD was determined by the antiendomysium antibody (IgA-EMA) test and by small intestine biopsy. RESULTS two of the 255 epileptic patients (1:127) and fifteen subjects from the control group (1:293) tested positive for the IgA-EMA assay. CONCLUSION the prevalence of CD was 2.3 times higher in epileptic patients than in controls (7.84 per 1000 versus 3.41 per 1000). Although still not statistically significant, this result is highly suggestive of an increased prevalence of CD among epileptic patients.

Extracts of Morus nigra L. Leaves Standardized in Chlorogenic Acid, Rutin and Isoquercitrin: Tyrosinase Inhibition and Cytotoxicity

Melanogenesis is a process responsible for melanin production, which is stored in melanocytes containing tyrosinase. Inhibition of this enzyme is a target in the cosmetics industry, since it controls undesirable skin conditions such as hyperpigmentation due to the overproduction of melanin. Species of the Morus genus are known for the beneficial uses offered in different parts of its plants, including tyrosinase inhibition. Thus, this project aimed to study the inhibitory activity of tyrosinase by extracts from Morus nigra leaves as well as the characterization of its chromatographic profile and cytotoxicity in order to become a new therapeutic option from a natural source. M. nigra leaves were collected, pulverized, equally divided into five batches and the standardized extract was obtained by passive maceration. There was no significant difference between batches for total solids content, yield and moisture content, which shows good reproducibility of the extraction process. Tyrosinase enzymatic activity was determined for each batch, providing the percentage of enzyme inhibition and IC50 values obtained by constructing dose-response curves and compared to kojic acid, a well-known tyrosinase inhibitor. High inhibition of tyrosinase activity was observed (above 90% at 15.625 μg/mL). The obtained IC50 values ranged from 5.00 μg/mL ± 0.23 to 8.49 μg/mL ± 0.59 and were compared to kojic acid (3.37 μg/mL ± 0.65). High Performance Liquid Chromatography analysis revealed the presence of chlorogenic acid, rutin and, its major compound, isoquercitrin. The chromatographic method employed was validated according to ICH guidelines and the extract was standardized using these polyphenols as markers. Cytotoxicity, assessed by MTT assay, was not observed on murine melanomas, human keratinocytes and mouse fibroblasts in tyrosinase IC50 values. This study demonstrated the potential of M. nigra leaf extract as a promising whitening agent of natural source against skin hyperpigmentation.

25-Hydroxy-vitamin D levels among Callithrix penicillata primate species raised in captivity

Background  Animals in captivity should receive adequate sunlight exposure for sufficient generation of vitamin D [25(OH)D]. In the present study, 25(OH)D serum levels of 84 Callithrix penicillata primates were evaluated.

DNA-hsp65 vaccine as therapeutic strategy to treat experimental chromoblastomycosis caused by Fonsecaea pedrosoi.

Chromoblastomycosis (CBM) is a chronic subcutaneous mycosis, caused by several dimorphic, pigmented dematiaceous fungi. Patients with the disease are still considered a therapeutic challenge, mainly due to its recalcitrant nature. There is no “gold standard” treatment for this neglected mycosis, but rather there are several treatment options. Chemotherapy alternatives include 5-flucytosine, itraconazole, terbinafine, fluconazole, thiabendazole, ketoconazole and amphotericin B, although the healing of severe cases is still uncommon. However, several studies have reported the DNA vaccine to be promising in the treatment for fungal infections; this vaccine allows the host to restore depressed cellular immunity, minimizing the toxic effects from conventional antifungal therapies. This work was therefore carried out aiming to establish a suitable model for experimental CBM, suggesting also new therapies, including DNA-hsp65 vaccine. By analyzing the morphometrical and histopathological aspects and by quantifying the fungal burden, the results showed the establishment of a chronic, although transitory, experimental CBM model with lesions similar to those presented in humans. A treatment regimen using intralesional itraconazole or amphotericin B was effective in treating experimental CBM, as was a therapy using naked DNA-hsp65 vaccine. It has also been shown that chemotherapy associated with DNA-hsp65 vaccine is promising in the treatment for CBM.

SIMPLIFYING CELIAC DISEASE PREDISPOSING HLA-DQ ALLELES DETERMINATION BY THE REAL TIME PCR METHOD

BACKGROUND Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Genetic susceptibility is associated with two sets of alleles, DQA1*05 - DQB1*02 and DQA1*03 - DQB1*03:02, which code for class II MHC DQ2 and DQ8 molecules, respectively. Approximately 90%-95% of celiac patients are HLA-DQ2 positive, and half of the remaining patients are HLA-DQ8 positive. In fact, during a celiac disease diagnostic workup, the absence of these specific DQA and DQB alleles has a near perfect negative predictive value. OBJECTIVE Improve the detection of celiac disease predisposing alleles by combining the simplicity and sensitivity of real-time PCR (qPCR) and melting curve analysis with the specificity of sequence-specific primers (SSP). METHODS Amplifications of sequence-specific primers for DQA1*05 (DQ2), DQB1*02 (DQ2), and DQA1*03 (DQ8) were performed by the real time PCR method to determine the presence of each allele in independent reactions. Primers for Human Growth Hormone were used as an internal control. A parallel PCR-SSP protocol was used as a reference method to validate our results. RESULTS Both techniques yielded equal results. From a total of 329 samples the presence of HLA predisposing alleles was determined in 187 (56.8%). One hundred fourteen samples (61%) were positive for a single allele, 68 (36.3%) for two alleles, and only 5 (2.7%) for three alleles. CONCLUSION Results obtained by qPCR technique were highly reliable with no discordant results when compared with those obtained using PCR-SSP.

Evaluation of 25-hydroxy-vitamin D and parathyroid hormone in Callithrix penicillata primates living in their natural habitat in Brazil

Vitamin D is a secosteroid hormone with important roles in the control of bone and mineral metabolism of vertebrates and in the maintenance of systemic homeostasis. This study aimed (i) to evaluate the serum concentrations of 25‐hydroxy‐vitamin D levels [25(OH)D], parathyroid hormone (PTH) and ionized calcium (iCa) of wild Callithrix penicillata (black‐tufted marmosets) and (ii) to propose reference ranges for those analytes for free‐living marmosets.

Gluten contamination in gluten-free bakery products: a risk for coeliac disease patients.

OBJECTIVE The present study aimed to assess the safety of gluten-free bakery products for consumption by coeliac patients. Design/setting In the current exploratory cross-sectional quantitative study, a total of 130 samples were collected from twenty-five bakeries in Brasilia (Brazil). For the quantification of gluten, an ELISA was used. The threshold of 20 ppm gluten was considered as the safe upper limit for gluten-free food, as proposed in the Codex Alimentarius. RESULTS The results revealed a total of 21·5 % of contamination among the bakery products sampled. Sixty-four per cent of the bakeries sold at least one contaminated product in our sample. CONCLUSIONS These findings represent a risk for coeliac patients since the ingestion of gluten traces may be sufficient to adversely impact on their health.

A Novel Structurally Stable Multiepitope Protein for Detection of HCV

Hepatitis C virus (HCV) has emerged as the major pathogen of liver diseases in recent years leading to worldwide blood-transmitted chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Accurate diagnosis for differentiation of hepatitis C from other viruses is thus of pivotal importance for proper treatment. In this work we developed a recombinant multiepitope protein (rMEHCV) for hepatitis C diagnostic purposes based on conserved and immunodominant epitopes from core, NS3, NS4A, NS4B, and NS5 regions of the virus polyprotein of genotypes 1a, 1b, and 3a, the most prevalent genotypes in South America (especially in Brazil). A synthetic gene was designed to encode eight epitopes in tandem separated by a flexible linker and bearing a his-tag at the C-terminal end. The recombinant protein was produced in Escherichia coli and purified in a single affinity chromatographic step with >95% purity. Purified rMEHCV was used to perform an ELISA which showed that the recombinant protein was recognized by IgG and IgM from human serum samples. The structural data obtained by circular dichroism (CD) spectroscopy showed that rMEHCV is a highly thermal stable protein at neutral and alkaline conditions. Together, these results show that rMEHCV should be considered an alternative antigen for hepatitis C diagnosis.

Presence of DQ2.2 Associated with DQ2.5 Increases the Risk for Celiac Disease

Background. Celiac disease (CD) is a genetically determined immune-mediated disorder in which gluten immunogenic peptides are presented to CD4 T cells by HLA-DQ2.5, DQ8, DQ2.2, and their combinations. Our aim is to establish a risk gradient for celiac disease based on HLA-DQ profile in a brazilian representative population and the relevance of DQ2.2 in celiac disease development. Materials and Methods. 237 celiac patients and 237 controls (both groups with 164 females and 73 males) were included. All samples were tested for the presence of predisposing HLA-DQ alleles using the PCR-SSP method. Results were considered significant when p < 0.05. Disease risk was expressed as 1 : N for each HLA-DQ category described at this study. Results. DQ2.5 and/or DQ8 were detected in 224 celiac patients (94.5%) and 84 controls (35.4%). Eight celiac patients (3.4%) and 38 controls (16%) disclosed only DQ2.2. Even though DQ2.2 (β2/β2 or β2/x) showed a low CD risk of 1 : 251 and 1 : 550, respectively, the genotype DQ2.5/DQ2.2 (β2/β2) showed high CD risk of 1 : 10 (p < 0.0001). The disease risk gradient ranged from 1 : 3014 to 1 : 7. Conclusion. Our study allowed the determination of a risk gradient for celiac disease development in at-risk population, showing that DQ2.2 variant was relevant when associated with DQ2.5.