Frequency of Infection of Lutzomyia Phlebotomines with Leishmania braziliensis in a Brazilian Endemic Area as Assessed by Pinpoint Capture and Polymerase Chain Reaction

Leishmania infected of Lutzomyia spp. are rare in endemic areas. We tested the hypothesis that there is clustering of infected vectors by combining pinpoint capture with sensitive L. braziliensis kDNA minicircle specific PCR/dot blot in an endemic area in the State of Bahia. Thirty out of 335 samples (10 to 20 sand flies/sample; total of 4,027 female sand flies) were positive by PCR analysis and dot blot leading to a underestimated overall rate of 0.4% positive phlebotomines. However, 83.3% of the positive samples were contributed by a single sector out of four sectors of the whole studied area. This resulted in a rate of 1.5% Leishmania positive phlebotomines for this sector, far above rates of other sectors. Incidence of American cutaneous leishmaniasis cases for this sector was about twice that for other sectors. Our results show that there is a non-homogeneous distribution of Leishmania-infected vectors. Such a clustering may have implications in control strategies against leishmaniasis, and reinforces the necessity of understanding the ecological and geographical factors involved in leishmanial transmission.

High frequency of skin reactions in patients with leishmaniasis treated with meglumine antimoniate contaminated with heavy metals: a comparative approach using historical controls

We analyzed data from historical controls treated with meglumine antimoniate to compare the frequency of adverse events observed in patients with cutaneous leishmaniasis treated with the same dose of meglumine antimoniate contaminated with heavy metals in an endemic area of the State of Bahia, Brazil. Group A patients were treated in 2000 with the drug produced by Eurofarma Laboratórios Ltda., São Paulo, Brazil (lot A) and group B patients were treated in 1996 with the reference drug produced by Rhodia Farma Ltda., São Paulo, Brazil (lot B). We observed an unusual higher frequency of skin reactions in group A patients. However, all type of adverse events observed in group A were also observed in group B. The physico-chemical analysis of these lots revealed that lot A had lower pH and higher concentration of total and trivalent antimony, lead, cadmium, and arsenic. Our findings suggest that the skin reactions could be attributed to heavy metal contamination of lot A.

Nodular typhlitis associated with the nematodes Heterakis gallinarum and Heterakis isolonche in pheasants: frequency and pathology with evidence of neoplasia

An investigation related to the frequency and pathology of Heterakis gallinarum and pathology of Heterakis isolonche in pheasants from Rio de Janeiro, Brazil was conducted by means of clinical examinations, necropsies, and histopathological analysis in 50 ring-necked pheasants from backyard flocks of 11 localities; also, histological sections of caeca of golden pheasants deposited in the Helminthological Collection of the Oswaldo Cruz Institute (CHIOC) have been considered in the present study. During necropsies, only specimens of H. gallinarum were recovered with a prevalence of 90%, mean intensity of 81.9 and range of infection of 1-413. Gross lesions were characterized by congestion, thickening, petechial haemorrhages of the mucosa, intussusception, and nodules in the cecal wall. Under microscopy, chronic difuse typhlitis, haemosiderosis, granulomas with necrotic center in the submucosa and leiomyomas in the submucosa, muscular and serosa associated with immature H. gallinarum worms were observed. The examination of histological sections previously deposited in the CHIOC, revealed more severe alterations associated with concomitant infections with H. gallinarum and H. isolonche in golden pheasants, and were characterized by several necrotic areas with cholesterol clefts in the submucosa, giant cell granulomas in the submucosa, and serosa centralized by necrosis and worm sections and neoplastic nodules in the muscular and submucosa.

Capillaria spp. eggs in Patagonian archaeological sites: statistical analysis of morphometric data

Discriminant analysis was used to identify eggs of Capillaria spp. at specific level found in organic remains from an archaeological site in Patagonia, Argentina, dated of 6,540 ± 110 years before present. In order to distinguish eggshell morphology 149 eggs were measured and grouped into four arbitrary subsets. The analysis used on egg width and length discriminated them into different morphotypes (Wilks' lambda = 0.381, p < 0.05). The correlation analysis suggests that width was the most important variable to discriminate among the Capillaria spp. egg morphotypes (Pearson coefficient = 0.950, p < 0.05). The study of eggshell patterns, the relative frequency in the sample, and the morphometric data allowed us to correlate the four morphotypes with Capillaria species.

Candidate gene analysis of ocular toxoplasmosis in Brazil: evidence for a role for toll-like receptor 9 (TLR9)

Toxoplasma gondii infection is an important mediator of ocular disease in Brazil more frequently than reported from elsewhere. Infection and pathology are characterized by a strong proinflammatory response which in mice is triggered by interaction of the parasite with the toll-like receptor (TLR)/MyD88 pathway. A powerful way to identify the role of TLRs in humans is to determine whether polymorphisms at these loci influence susceptibility to T. gondii-mediated pathologies. Here we report on a small family-based study (60 families; 68 affected offspring) undertaken in Brazil which was powered for large effect sizes using single nucleotide polymorphisms with minor alleles frequencies > 0.3. Of markers in TLR2, TLR5 and TLR9 that met these criteria, we found an association Family Based Association Tests [(FBAT) Z score = 4.232; p = 1.5 x 10-5; p corrected = 1.2 x 10-4] between the C allele (frequency = 0.424; odds ratio = 7; 95% confidence interval 1.6-30.8) of rs352140 at TLR9 and toxoplasmic retinochoroiditis in Brazil. This supports the hypothesis that direct interaction between T. gondii and TLR9 may trigger proinflammatory responses that lead to severe pathologies such as the ocular disease that is associated with this infection in Brazil.

Sequence analysis of coding DNA fragments of pfcrt and pfmdr-1 genes in Plasmodium falciparum isolates from Odisha, India

The global emergence and spread of malaria parasites resistant to antimalarial drugs is the major problem in malaria control. The genetic basis of the parasite's resistance to the antimalarial drug chloroquine (CQ) is well-documented, allowing for the analysis of field isolates of malaria parasites to address evolutionary questions concerning the origin and spread of CQ-resistance. Here, we present DNA sequence analyses of both the second exon of the Plasmodium falciparum CQ-resistance transporter (pfcrt) gene and the 5' end of the P. falciparum multidrug-resistance 1 (pfmdr-1) gene in 40 P. falciparum field isolates collected from eight different localities of Odisha, India. First, we genotyped the samples for the pfcrt K76T and pfmdr-1 N86Y mutations in these two genes, which are the mutations primarily implicated in CQ-resistance. We further analyzed amino acid changes in codons 72-76 of the pfcrt haplotypes. Interestingly, both the K76T and N86Y mutations were found to co-exist in 32 out of the total 40 isolates, which were of either the CVIET or SVMNT haplotype, while the remaining eight isolates were of the CVMNK haplotype. In total, eight nonsynonymous single nucleotide polymorphisms (SNPs) were observed, six in the pfcrt gene and two in the pfmdr-1 gene. One poorly studied SNP in the pfcrt gene (A97T) was found at a high frequency in many P. falciparum samples. Using population genetics to analyze these two gene fragments, we revealed comparatively higher nucleotide diversity in the pfcrt gene than in the pfmdr-1 gene. Furthermore, linkage disequilibrium was found to be tight between closely spaced SNPs of the pfcrt gene. Finally, both the pfcrt and the pfmdr-1 genes were found to evolve under the standard neutral model of molecular evolution.

Association analysis of human leukocyte antigen class II (DRB1) alleles with leprosy in individuals from São Luís, state of Maranhão, Brazil

Epidemiological studies have demonstrated that the variability of the clinical response to infection caused by Mycobacterium leprae is associated with host genetic factors. The present study investigated the frequency of human leukocyte antigen (HLA) class II (DRB1) alleles in patients with leprosy from São Luís, Maranhão, Brazil. A case-control study was performed in 85 individuals with leprosy and 85 healthy subjects. All samples were analysed via polymerase chain reaction-sequence specific oligonucleotide probes. The HLA-DRB1*16 allele showed a higher frequency in the group with leprosy [(9.41% vs. 4.12%) odds ratio (OR) = 2.41 95% confidence interval (CI) (0.96-6.08) p = 0.05], whereas the HLA-DRB1*11 allele was less frequent in the group with leprosy [(6.47% vs. 11.76%) OR = 0.51 95% CI (0.23-1.12) p = 0.09]. The frequency of HLA-DRB1* alleles between the control group and leprosy patient subgroups presenting different forms of the disease showed that the HLA-DRB1*16 (16.13% vs. 8.24%, OR = 4.10, CI = 1.27-13.27, p = 0.010) and HLA-DRB1*14 (5% vs. 3.53%, OR = 4.63, CI = 1.00-21.08, p = 0.032) alleles were significantly more frequent in patients with different clinical subtypes of leprosy. The sample size was a limitation in this study. Nevertheless, the results demonstrated the existence of a genetic susceptibility associated with the clinical forms of leprosy. The low frequency of the HLA-DRB1*11 allele should be further studied to investigate the possible protective effect of this allele.

Comparative analysis of the tissue inflammatory response in human cutaneous and disseminated leishmaniasis

Cutaneous leishmaniasis (CL) is the most frequent clinical form of tegumentary leishmaniasis and is characterised by a single or a few ulcerated skin lesions that may disseminate into multiple ulcers and papules, which characterise disseminated leishmaniasis (DL). In this study, cells were quantified using immunohistochemistry and haematoxylin and eosin staining (CD4+, CD68+, CD20+, plasma cells and neutrophils) and histopathology was used to determine the level of inflammation in biopsies from patients with early CL, late CL and DL (ulcers and papules). The histopathology showed differences in the epidermis between the papules and ulcers from DL. An analysis of the cells present in the tissues showed similarities between the ulcers from localised CL (LCL) and DL. The papules had fewer CD4+ T cells than the DL ulcers. Although both CD4+ cells and macrophages contribute to inflammation in early CL, macrophages are the primary cell type associated with inflammation intensity in late ulcers. The higher frequency of CD20+ cells and plasma cells in lesions demonstrates the importance of B cells in the pathogenesis of leishmaniasis. The number of neutrophils was the same in all of the analysed groups. A comparison between the ulcers from LCL and DL and the early ulcers and papules shows that few differences between these two clinical forms can be distinguished by observing only the tissue.

General trends in world biogeographic literature: a preliminary bibliometric analysis

Records with the search string biogeograph* were collected from the Science Citation Index (SCI). A total of 3456 records were downloaded for the 1945-2006 period from titles of articles and reviews, and 10,543 records were downloaded for 1991-2006, taking into consideration also abstracts and keywords. Temporal trends of publications, geographical and institutional distribution of the research output, authorship, and core journals were evaluated. There were as many as 122 countries carrying out biogeographic research; in the most recent period, USA is the top producing country, followed by the United Kingdom, Australia, France, Germany, Spain, and Canada. There were 17,493 authors contributing to the field. During 1991-2006 there were 4098 organizations with authors involved in biogeographic research; institutions with higher number of papers are the Natural History Museum (United Kingdom), the University of California, Berkeley (USA), the Museum National d'Histoire Naturelle (France), the Universidad Nacional Autónoma de México (Mexico), the American Museum of Natural History (USA) and the Russian Academy of Sciences (Russia). Research articles are spread over a variety of journals, with the Journal of Biogeography, Molecular Phylogenetics and Evolution, Molecular Ecology, and Biological Journal of the Linnean Society being the core journals. From 28,759 keywords retrieved those with the highest frequency were evolution, phylogeny, diversity, mitochondrial DNA, pattern(s), systematics, and population(s). We conclude that publications on biogeography have increased substantially during the last years, especially since 1998. The preferred journal for biogeographic papers is the Journal of Biogeography. Most frequent keywords seem to indicate that biogeography fits well within both evolutionary biology and ecology, with molecular biology and phylogenetics being important factors that drive their current development.

Phenotypic virulence analysis of Pyricularia grisea isolates from Brazilian upland rice cultivars

Phenotypic virulence analysis was made on population of Pyricularia grisea isolates collected from 10 upland cultivars in three distinct rice breeding sites, with the objective of studying the degree of similarity in the phenotypic virulence among the isolates, the composition of races, and their virulence pattern. Sixteen races were identified based on the reaction type on eight standard international differentials, the predominant ones being IB9 and IB41. The virulence frequency was high on IAC47 and IAC165 among medium and early maturing cultivars, respectively. The frequency of isolates virulent was greater on upland rice cultivars (51.1%) than on irrigated rice cultivars (21.8%). Both virulent and avirulent isolates were present in the population of P. grisea to the known genes in the near isogenic lines. Of72test isolates, 94.4% were virulent for genes Pi3 and Pi4a. Thevirulence frequencies were relatively lower in decreasing order on Pi1, Pi4b and Pi2. Thecoefficient of similarity ranged from 0.28 to1.0 among the isolates pertaining to different races, while within the race IB9, it varied from 0.56 to1.0. Considering the coefficient of similarity of 0.81, 72% of isolates of race IB9 exhibited similar pattern of virulence.

Study of the skin anatomy with high-frequency (22 MHz) ultrasonography and histological correlation

AbstractThe present essay is aimed at getting the radiologist familiar with the basic histological skin structure, allowing for a better correlation with sonographic findings. A high-frequency (22 MHz) ultrasonography apparatus was utilized in the present study. The histological analysis was performed after the skin specimens fixation with formalin, inclusion in paraffin blocks and subsequent staining with hematoxylin-eosin. The authors present a literature review showing the relationship between sonographic and histological findings in normal cutaneous tissue, and discuss the technique for a better performance of the sonographic scan. High-frequency ultrasonography is an excellent tool for the diagnosis of different skin conditions. However, as this method is operator-dependent, it is crucial to understand the normal skin structure as well as the correlation between histological and sonographic findings.

A pH optode based on thymol blue: application to determination of CO2 using flow injection analysis system

An optode based on thymol blue (TB), an acid-based indicator, has been constructed and evaluated as a detector in FIA system for CO2 determination. The dye was chemically immobilised on the surface of a bifurcated glass optical fibre bundle, using silanisation in organic media. In FIA system, hydrogen carbonate or carbonate samples are injected in a buffer carrier solution, and then are mixed with phosphoric acid solution to generate CO2, which diffuses through a PTFE membrane, in order to be collected in an acceptor carrier fluid, pumped towards to detection cell, in which the optode was adapted. The proposed system presents two linear response ranges, from 1.0 x 10-3 to 1.0 x 10-2 mol l-1, and from 2.0 x 10-2 to 0.10 mol l-1. The sampling frequency was 11 sample h-1, with good repeatability (R.S.D < 4 %, n = 10). In flow conditions the optode lifetime was 170 h. The system was applied in the analysis of commercial mineral water and the results obtained in the hydrogen carbonate determination did not differ significantly from those obtained by potentiometry, at a confidence level of 95 %.

Intensity-duration-frequency ratios obtained from annual records and partial duration records in the locality of Pelotas - RS, Brazil

The intensity-duration-frequency occurrence ratio (IDF) is a tool commonly used for precipitation-runoff data transformation, which is established from observations of intense precipitations over a period sufficiently long as to allow the occurrence of extremes at the observation site. This study focused on verifying the existence or absence of new data, in terms of IDF ratio, by using partial duration records produced from data on maximum daily disaggregated rainfall for pre determined durations. The partial duration records considered a base value of 55 mm, totaling 279 values. After the rainfall series were established, their independence and seasonality were assessed. Using the Student's t-test statistics, it was established that no new data, as IDF ratio, emerged from the analysis of the partial duration series with the recommended base value of precipitation, as compared to the historical records.

Method adjustment and equation set of maximum rainfall intensity, duration and frequency in the Mato Grosso do Sul State

Due to the lack of information concerning maximum rainfall equations for most locations in Mato Grosso do Sul State, the alternative for carrying out hydraulic work projects has been information from meteorological stations closest to the location in which the project is carried out. Alternative methods, such as 24 hours rain disaggregation method from rainfall data due to greater availability of stations and longer observations can work. Based on this approach, the objective of this study was to estimate maximum rainfall equations for Mato Grosso do Sul State by adjusting the 24 hours rain disaggregation method, depending on data obtained from rain gauge stations from Dourado and Campo Grande. For this purpose, data consisting of 105 rainfall stations were used, which are available in the ANA (Water Resources Management National Agency) database. Based on the results we concluded: the intense rainfall equations obtained by pluviogram analysis showed determination coefficient above 99%; and the performance of 24 hours rain disaggregation method was classified as excellent, based on relative average error WILMOTT concordance index (1982).

Comparative analysis between identified injuries of victims of fall from height and other mechanisms of closed trauma

OBJECTIVE: To analyze the lesions diagnosed in victims of falls, comparing them with those diagnosed in other mechanisms of blunt trauma.METHODS: We conducted a retrospective study of trauma protocol charts (prospectively collected) from 2008 to 2010, including victims of trauma over 13 years of age admitted to the emergency room. The severity of injuries was stratified by the Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS). Variables were compared between the group of victims of falls from height (Group 1) and the other victims of blunt trauma (Group 2). We used the Student t, chi-square and Fisher tests for comparison between groups, considering the value of p <0.05 as significant.RESULTS: The series comprised 4,532 cases of blunt trauma, of which 555 (12.2%) were victims of falls from height. Severe lesions (AISe"3) were observed in the extremities (17.5%), in the cephalic segment (8.4%), chest (5.5%) and the abdomen (2.9%). Victims of Group 1 had significantly higher mean age, AIS in extremities / pelvis, AIS in the thoracic segment and ISS (p <0.05). The group 1 had significantly (p <0.05) higher incidence of tracheal intubation on admission, pneumothorax, hemothorax, rib fractures, chest drainage, spinal trauma, pelvic fractures, complex pelvic fractures and fractures to the upper limbs.CONCLUSION: Victims of fall from height had greater anatomic injury severity, greater frequency and severity of lesions in the thoracic segment and extremities.