Trypanosoma rangeli: discrimination from Trypanosoma cruzi based on a variable domain from the large subunit ribosomal RNA gene

306-314. Three synthetic oligonucleotides corresponding to sequences within the D7a divergent domain of the large subunit ribosomal RNA gene have been used to amplify the total DNA of Trypanosoma rangeli and Trypanosoma cruzi, two morphologically similar protozoa with overlapping geographical distribution and hosts. The two organisms may be distinguished by the electrophoretic mobilities of their respective amplification products. For T. rangeli a 210-bp product was obtained. The presence of this fragment was confirmed in 14 T. rangeli strains. For T. cruzi two possible amplification products were originated: a 265-bp DNA fragment for strains typed as lineage 1 and a 250-bp fragment for lineage 2 strains. Eleven unidentified trypanosome stocks, recently isolated from Amazonian vectors, could be discriminated using the proposed assay. The potential field application of multiplex PCR was further demonstrated by identification of the two parasite species in samples containing intestinal tract and feces of triatomines. In the present study we have also amplified the D7a domain of several trypanosomatids employing primers complementary to the conserved flanking regions. Size and sequence polymorphisms were observed, indicating that this region could also be explored as a target for specific detection of other members of the Trypanosomatidae family.     

Perspective of a new diagnostic for human trichomonosis

Several diagnostic techniques have been employed for the detection of Trichomonas vaginalis. Microtubules constitute the cytoskeleton in eukaryotic cells and are sensitive to antimitotic drugs, such as Taxol (paclitaxel). We used FLUTAX a fluorescent taxoid - to analyze the microtubule distribution in living trophozoites of T. vaginalis in urine and in vaginal discharge. A high intensity of fluorescence was observed in living T. vaginalis, epithelial cells and leukocytes present in urine and vaginal discharge. Our preliminary results show the perspective of a new diagnostic technique for trichomonosis and will contribute to the understanding of the cytoskeleton of T. vaginalis.     

Genetic determinants of variation in the plasma levels of the C4b-binding protein (C4BP) in Spanish families

The C4b-binding protein (C4BP) is a plasma glycoprotein implicated in the homeostasis of the complement and coagulation systems. It is composed of two polypeptides (alpha and beta), which form three plasma oligomers with different subunit compositions (alpha(7)beta(1), alpha(7)beta(0), and alpha(6)beta(1)). The beta chain-containing C4BP isoforms (C4BPbeta(+)isoforms) bind and inactivate protein S (PS), downregulating the activated protein C (APC)-dependent anticoagulatory pathway. Because PS deficiency is associated with recurrent thrombosis, it has been suggested that increased levels of C4BPbeta(+)isoforms might diminish the free PS plasma level, affecting the risk of developing thromboembolism. Previous work has tested this hypothesis, but no definitive conclusions were reached, mostly because nothing is known about the factors influencing the high variability in C4BP plasma levels in humans. As a part of the GAIT project, using variance component analysis, this work provides the first estimation of the relative contributions of genetic and environmental influences on the plasma levels of total C4BP and C4BPbeta(+)isoforms. Plasma levels of total C4BP and C4BPbeta(+)isoforms showed strong evidence of genetic regulation (heritability 37.7% and 42.5%, respectively). They were also affected by age, smoking, and exogenous sex hormones. Our results constitute the first step in localizing and evaluating potential quantitative trait loci that affect the plasma levels of C4BP and C4BPbeta(+). Furthermore, analysis of phenotypic and genetic correlations between C4BPbeta(+)plasma levels and the components of the APC anticoagulatory pathway (total PS, free PS, functional PS, and functional PC) suggests a genetic co-regulation of the proteins. These observations might have important implications in the individual susceptibility to thrombotic disease.     

Immunopurification and characterization of rat adipocyte caveolae suggest their dissociation from insulin signaling

Adipocytes play an important role in the insulin-dependent regulation of organismal fuel metabolism and express caveolae at levels as high or higher than any other cell type. Recently, a link between insulin signaling and caveolae has been suggested; nevertheless, adipocyte caveolae have been the subject of relatively few studies, and their contents have been minimally characterized. With the aid of a new monoclonal antibody, we developed a rapid procedure for the immunoisolation of caveolae derived from the plasma membrane of adipocytes, and we characterized their protein content. We find that immunopurified adipocyte caveolae have a relatively limited protein composition, and they lack the raft protein, flotillin, and insulin receptors. Immunogold labeling and electron microscopy of the adipocyte plasma membrane confirmed the lack of insulin receptors in caveolae. In addition to caveolins, the structural components of caveolae, their major protein constituents, are the semicarbazide-sensitive amine oxidase and the scavenger lipoprotein receptor CD36. The results are consistent with a role for caveolae in lipid flux in and of adipocytes.     

Relationship between maize stem structural characteristics and resistance to pink stem borer (Lepidoptera: Noctuidae) attack

The pink stem borer, Sesamia nonagrioides (Lefebvre), is one of the most important insect pests of maize (Zea mays L.) in northwestern Spain. The objectives of this work were to evaluate, at different times during the growth of maize, structural traits related to the entry point and tissues on which larvae feed and to determine the relationship between these structural traits and the stem borer resistance. Six inbred lines with different levels of stem resistance to S. nonagrioides were evaluated in several trials. Potential structural resistance factors included rind and pith puncture resistance (RPR and PPR), rind thickness, length of the meristematic area (LMA), and pith parenchyma interlumen thickness (PPIT). Surprisingly, the inbred lines that showed the strongest stalks, EP42 and EP47, were not stem resistant to pink stem borer attack, while the stem resistant inbreds A509, CM151, and PB130 were among the least resistant to rind puncture. There were no significant differences among resistant and susceptible inbreds for the rind thickness. However, the susceptible inbred EP42 had the softest internode pith, and the resistant inbred PB130 showed the hardest, as was expected. Susceptible inbred lines in general showed higher values for the LMA, while the PPIT was important for individual inbreds. The results suggest that the usefulness of these characters as estimators of pink stem borer resistance is limited to some genotypes. Besides, even among those genotypes, other mechanisms of resistance that do not involve stalk strength could be present. Among the traits considered, the LMA was the most promising as an indicator of resistance to pink stem borer, although further experimentation is necessary.     

Trichomonas vaginalis: microtubule cytoskeleton distribution using fluorescent taxoid

Trichomonas vaginalis is a flagellated parasitic protist of the human urogenital tract. The parasite has a poorly known cytoskeleton formed by an axostyle and a pelta, which are formed by stable structures such as microtubules, essential for the maintenance of cell shape and organization. FLUTAX-2 is an active fluorescent derivative of Taxol, binds to alphabeta-tubulin dimer polymerized. In this paper we present the analysis of microtubule distribution in living trophozoites of T. vaginalis using FLUTAX-2.     

Seroepidemiological markers of enterically transmitted viral hepatitis A and E in individuals living in a community located in the North Area of Rio de Janeiro,RJ, Brazil

We investigated the seroprevalence of hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in subjects living in the community of Manguinhos, Rio de Janeiro, Brazil, and assisted at the Health Unit of Escola Nacional de Saúde Pública, Funda??o Oswaldo Cruz. After formal consent, individuals were submitted to an interview using a standardized questionnaire. Anti-HAV and anti-HEV antibodies were detected by ELISA. Statistical analysis was carried out using the Epi-Info 6.04b software, to investigate possible associations between serological markers and risk factors. Results were regarded as significant when p value < 0.05. Although a high prevalence of anti-HAV was observed (87%), almost 50% of subjects under the age of 10 were susceptible to HAV infection, an unexpected rate in endemic areas. This fact could be attributed to improvements in environmental sanitation, occurring in this area in the last years. The increasing proportion of susceptible people may result in outbreaks of HAV infection, since the virus still circulates in this area, as verified by the detection of anti-HAV IgM in some individuals. No statistical association was met between HAV infection and the risk factors here assessed. The anti-HEV IgG prevalence found in this population was 2.4%, consistent with the one found in non-endemic areas.     

Assessment of post extraction complications in Indians

Extraction is one of the commonest procedures in dentistry. Therefore, it is of interest to evaluate the post extraction complications in patients undergoing extractions of permanent teeth. A total of 70 adult patients who had undergone dental extractions and presented with post -operative complications were included in the study and evaluated. Data collected was statistically analyzed using SPSS software and results obtained. Most of the patients with post extraction complications were in the age group of 31-40 years (21.6%), followed by 21-30 (20.2%) and 61-70 years (20.2%). Dry socket (39.19%) was the common post extraction complication in our study especially in the age group of 31-40 years. There was a statistically significant association between age of the patients and the post extraction complications (p<0.001). In our study, post extraction complications were commonly observed in age group of 31-40 years with a predilection for males. Dry socket was the most common post extraction complication. Age of the patient has a significant effect on post extraction complications. However, gender, smoking habits and systemic diseases have no influence on post extraction complications.