Histórico de vida de espécimens selvagens e variantes cromáticas de Gracilaria birdiae (Gracilariales, Rhodophyta)

(Gracilariales, Rhodophyta) é uma macroalga marinha de coloração vermelha (vm) comum na costa Nordeste do Brasil e amplamente coletada para a extração de ágar. O objetivo deste estudo foi completar o histórico de vida de espécimens selvagens (coloração vermelha) e variantes cromáticas. Duas variantes foram isoladas, além dos espécimens selvagens coletados na praia de Paracuru, Ceará: i, marrom-esverdeada (me), encontrada em uma população natural da praia de Paracuru; e ii, verde (vd), obtida espontaneamente in vitro a partir de um ramo tetrasporofítico. As condições gerais de cultivo tanto para gametófitos quanto para tetrasporófitos foram: meio de cultura von Stosch 25%; fotoperíodo 14L:10E (luz: escuro); irradiância 100 µm.m-2.s-1 e aeração a cada 30 min. Tetrasporófitos das três colorações e gametófitos verdes foram cultivados também em 10L:14E. O histórico de vida foi completado in vitro em 498 (vm), 523 (me) e 861 (vd) dias, mostrando-se do tipo Polysiphonia. Tetrasporófitos produziram tetrásporos apenas em fotoperíodo 10L:14E. Gametófitos femininos verdes desenvolveram cistocarpos apenas em fotoperíodo 14L:10E. No entanto, a diferenciação de conceptáculos do tipo verrucosa em gametófitos masculinos verdes e a liberação de espermácios ocorreu em ambos os fotoperíodos. Gametófitos masculinos vermelhos apresentaram conceptáculos espermatangiais do tipo henriquesiana, enquanto gametófitos masculinos marrom-esverdeados apresentaram os tipos verrucosa e henriquesiana. Não foram verificadas diferenças quanto ao hábito de espécimens de uma mesma coloração, independentemente do estádio reprodutivo analisado. Verificou-se em todos os tetrasporófitos a germinação de tetrásporos in situ.

Trypanosoma cruzi: expression of antigenic component 5 among 35 laboratory clones obtained from 18 different isozymic variants

Two monoclonal antibodies anti-component 5 of Trypanosoma cruzi (I-35/115 and II-190/30) were tested in IFA and ELISA respectively against 35 T. cruzi laboratory clones. Among the 35 clones tested, 18 different isozyme patterns were detected. All clones were recognized by both monoclonal antibodies except one clone which did not react with II-190/30. These results support the universal expression of specific component 5 within the taxon T. cruzi.

Smqnr VARIANTS IN CLINICAL ISOLATES OF Stenotrophomonas maltophilia IN BRAZIL

SUMMARYStenotrophomonas maltophilia contains a novel chromosomally-encoded qnr gene named Smqnr that contributes to low intrinsic resistance to quinolone. We described Smqnr in 13 clinical isolates of S. maltophilia from two Brazilian hospitals, over a 2-year period. The strains were identified by API 20 NE (bioMérieux, France). Susceptibility by microdilution method to trimetroprim/sulfamethoxazole, ciprofloxacin, levofloxacin, minocycline, ceftazidime, chloramphenicol and ticarcillin/clavulanate was performed according to CLSI. PCR detection of Smqnr gene was carried out. The sequence of Smqnr was compared with those deposited in GenBank. Pulsed-field gel electrophoresis (PFGE) of all strains was performed. Thirteen Smqnr positives isolates were sequenced and three novel variants of Smqnr were identified. All 13 Smqnr isolates had distinguishable patterns by PFGE. This is the first report of Smqnr in S. maltophilia isolated in Brazil.

Morphological Studies on the Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae, Triatominae) Genital Structures and Eggs of Different Chromatic Forms

Triatoma brasiliensis is considered one of the most important Chagas disease vectors being a widespread species in semiarid areas of northeastern Brazil. The species displays distinct chromatic patterns of the cuticle in different localities. Four populations were analyzed in this study: 1-Caicó, Rio Grande do Norte, it will be called the brasiliensis population; 2-Espinosa, Minas Gerais, the melanica population; 3-Petrolina, Pernambuco, the macromelasoma population, and 4-Juazeiro, Bahia, the darker one in overall cuticle coloration, the Juazeiro population. In order to differentiate the four populations of T. brasiliensis, a comparative morphological analysis of external genital structures and of eggs were carried out. The analysis of the male genital structures evidenced minor individual structural variations that did not correlate with chromatic differences or the geographical origins, emphasizing the importance of examining sufficiently large and representative samples before using minor genital variations for taxonomic diagnosis. By scanning electron microscopy of the egg exochorion, each chromatic population presented a distinct ornamentation pattern. The melanica population differed mainly from the other populations studied since it had about 40.6%, 69.6% and 76.6% more perforations, on each cell exochorion, than the brasiliensis, the Juazeiro and the macromelasoma populations respectively. In the melanica population the perforation layout is also peculiar, with densely distributed perforations over all the egg surface. Morphometric measures of the eggs showed statistically significant differences: the macromelasoma population presented the longest length (2.43 mm) while the shortest was recorded in the brasiliensis population (2.29 mm).

Variants of the Plasmodium vivax circumsporozoite protein (VK210 and VK247) in Colombian isolates

Phenotypic diversity has been described in the central repeated region of the circumsporozoite protein (CSP) from Plasmodium vivax. Two sequences VK210 (common) and VK247 (variant) have been found widely distributed in P. vivax isolates from several malaria endemic areas around the world. A third protein variant called P. vivax-like showing a sequence similar to the simian parasite P. simio-ovale has also been described. Here, using an immunofluorescent test and specific monoclonal antibodies, we assessed the presence of two of these protein variants (VK210 and VK247) in laboratory produced sporozoite. Both sequences were found in parasite isolates coming from different geographic regions of Colombia. Interestingly, sporozoites carrying the VK247 sequence were more frequently produced in Anopheles albimanus than sporozoites with the VK210 sequence. This difference in sporozoites production was statistically significant (p <0.05, Kruskal-Wallis); not correlation was found with parameters as the total number of parasites or gametocytes in blood from human donors used to feed mosquitoes. Previous studies in the same region have shown a higher prevalence of anti-VK210 antibodies which in theory may suggest their role in blocking the development of sporozoites carrying the CSP VK210 sequence.

Triatoma rubrovaria (Blanchard, 1843) (Hemiptera: Reduviidae) I: isoenzymatic and chromatic patterns of five populations from the State of Rio Grande do Sul, Brazil

Triatoma rubrovaria has become the most frequently captured triatomine species since the control of T. infestans in the State of Rio Grande do Sul (RS), Brazil. In order to evaluate the genetic variability of this species, field collections were performed in four municipalities where it has been reported and distant from 75 to 322 km. Specimens were analyzed by color pattern and isoenzymes. Nine enzymatic loci were interpreted from nine enzymatic systems. The Santiago population was isolated from the others with chromatic monomorphism and diagnostic alleles at Idh and Pgm loci. The study shows the existence of, at least, two distinct populations of T. rubrovaria in RS with different phenotypic and genetic pattern.

Prevalence of human papillomavirus type 16 variants in the Federal District, Central Brazil

We report the prevalence of human papillomavirus type 16 (HPV-16) variants in women with cervical lesions from the Federal District, Central Brazil. We analyzed 34 HPV-16 samples, identifying the sequence variations of E6 and L1 genes and correlating variant frequency with disease status. The most prevalent HPV-16 variant was the European (50%), followed by Asian-American (41.2%), African-1 (5.9%), and African-2 (2.9%). European and non-European variants appeared in equal frequencies among the cytological types of lesions - atypical squamous or glandular cells of undetermined significance, cytological alterations suggesting HPV infection, cervical intraepithelial neoplasias, squamous cell carcinoma, and adenocarcinoma.

Association of hepatitis C virus NS5B variants with resistance to new antiviral drugs among untreated patients

Mutations located in the 109-amino acid fragment of NS5B are typically associated with resistance to interferon (IFN) and ribavirin (RIB) and to new antiviral drugs. The prevalence of these mutations was examined in 69 drug-naïve individuals with hepatitis C virus (HCV) infections in Rio de Janeiro, Brazil. Mutations related to non-response to IFN/RIB were observed in all subtypes studied (1a, 1b, 2b, 3a and 4). The most common mutation was Q309R, present in all subtypes, except subtype 2b with frequency above 20%. D244N was detected only in subtype 3a and A333E was detected only in subtype 2b. We did not detect the S282T, S326G or T329I mutations in any of the samples analysed. Of note, the C316N mutation, previously related to a new non-nucleoside compound (HCV796 and AG-021541), was observed in only eight of 33 (24%) samples from subtype 1b. Site 316 was under positive selection in this HCV variant. Our data highlight the presence of previously described resistance mutations in HCV genotypes from drug-naïve patients.

G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

Association of bGH and Pit-1 gene variants with milk production traits in dairy Gyr bulls

The objective of this study was to obtain genetic marker information in the Gyr breed by analyzing bGH and Pit-1 gene polymorphisms and to verify their association with milk production traits. One sample including 40 Gyr bulls were genotyped at two bGH gene restriction sites (bGH- AluI and bGH-MspI) and at one restriction site in the Pit-1 gene (Pit-1 HinfI). The bGH-MspI(-) allele was favorable for fat milk percentage. The heterozigous Pit-1 HinfI (+/-) bulls were superior for fat milk production, in relation to homozigous Pit-1 HinfI (+/+). The Pit-1 and bGH genes are strong candidates in the dairy cattle QTL search, and zebuine populations are promising samples for this purpose.

Inheritance of late flowering in natural variants of soybean cultivars under short-day conditions

The objective of this work was to determine the inheritance of the long juvenile period trait in natural variants of the Doko, BR 9 (Savana), Davis, Embrapa 1 (IAS 5RC), and BR 16 soybean cultivars. Complete diallel crosses were made between the Doko and BR 16 cultivars and their variants. A 3:1 segregation ratio was observed in the F2 populations of the 'Doko' x Doko-18T, 'Doko' x Doko-Milionária, 'Davis' x São Carlos, and 'BR 9 (Savana)' x MABR92-836 (Savanão) crosses, indicating that the long juvenile period trait is controlled by a pair of recessive genes. The difference in late flowering between the Doko cultivar and both of its variants was caused by a recessive spontaneous mutation at the same genetic locus. However, the variants Doko-18T and Doko-Milionária are identical mutants that share a pair of genes that control the long juvenile period under short-day conditions. These mutants can be used in breeding programs to develop cultivars adapted to low-latitude tropical regions.

Multidetector computed tomography angiography of the celiac trunk and hepatic arterial system: normal anatomy and main variants

Abstract Although digital angiography remains as the gold standard for imaging the celiac arterial trunk and hepatic arteries, multidetector computed tomography in association with digital images processing by software resources represents a useful tool particularly attractive for its non invasiveness. Knowledge of normal anatomy as well as of its variations is helpful in images interpretation and to address surgical planning on a case-by-case basis. The present essay illustrates several types of anatomical variations of celiac trunk, hepatic artery and its main branches, by means of digitally reconstructed computed tomography images, correlating their prevalence in the population with surgical implications.

Two variants of HIV-1 B serotype are transmitted heterosexually in São Paulo, Brazil

HIV-1 variability may have an important impact on transmission and pathogenicity. Better characterization of the HIV epidemic in Brazil is necessary for the development of vaccine trials in this country. We analyzed sera from 108 HIV-1-infected volunteers from São Paulo City to determine serotype and reactivity for V3 motifs of HIV in this population, and the relationship to transmission mode. We concluded that the HIV-1 B serotype is frequent among heterosexually infected women, even in the absence of anal sex, and that two major V3 motifs, GPGR and GWGR, had similar prevalence among women (48% and 52%, respectively) and men (56% and 44%, respectively). We also observed an equal distribution of these strains regardless of their CD4+ T cell counts, clinical status, and mode of transmission. Even though V3 serology for HIV-1 subtyping is an inexpensive tool for use in developing countries, additional methods, such as heteroduplex mobility assay and direct DNA sequencing, should be included to determine HIV-1 genetic diversity.

Effect of race, genetic population structure, and genetic models in two-locus association studies: clustering of functional renin-angiotensin system gene variants in hypertension association studies

Previous genetic association studies have overlooked the potential for biased results when analyzing different population structures in ethnically diverse populations. The purpose of the present study was to quantify this bias in two-locus association studies conducted on an admixtured urban population. We studied the genetic structure distribution of angiotensin-converting enzyme insertion/deletion (ACE I/D) and angiotensinogen methionine/threonine (M/T) polymorphisms in 382 subjects from three subgroups in a highly admixtured urban population. Group I included 150 white subjects; group II, 142 mulatto subjects, and group III, 90 black subjects. We conducted sample size simulation studies using these data in different genetic models of gene action and interaction and used genetic distance calculation algorithms to help determine the population structure for the studied loci. Our results showed a statistically different population structure distribution of both ACE I/D (P = 0.02, OR = 1.56, 95% CI = 1.05-2.33 for the D allele, white versus black subgroup) and angiotensinogen M/T polymorphism (P = 0.007, OR = 1.71, 95% CI = 1.14-2.58 for the T allele, white versus black subgroup). Different sample sizes are predicted to be determinant of the power to detect a given genotypic association with a particular phenotype when conducting two-locus association studies in admixtured populations. In addition, the postulated genetic model is also a major determinant of the power to detect any association in a given sample size. The present simulation study helped to demonstrate the complex interrelation among ethnicity, power of the association, and the postulated genetic model of action of a particular allele in the context of clustering studies. This information is essential for the correct planning and interpretation of future association studies conducted on this population.

Changes in red blood cell osmotic fragility induced by total plasma and plasma fractions obtained from rats bearing progressive and regressive variants of the Walker 256 tumor

Two variants (A and B) of the widely employed Walker 256 rat tumor cells are known. When inoculated sc, the A variant produces solid, invasive, highly metastasizing tumors that cause severe systemic effects and death. We have obtained a regressive variant (AR) whose sc growth is slower, resulting in 70-80% regression followed by development of immunity against A and AR variants. Simultaneously with the beginning of tumor regression, a temporary anemia developed (~8 days duration), accompanied by marked splenomegaly (~300%) and changes in red blood cell osmotic fragility, with mean corpuscular fragility increasing from 4.1 to 6.5 g/l NaCl. The possibility was raised that plasma factors associated with the immune response induced these changes. In the present study, we identify and compare the osmotic fragility increasing activity of plasma fractions obtained from A and AR tumor bearers at different stages of tumor development. The results showed that by day 4 compounds precipitating in 60% (NH4)2SO4 and able to increase red blood cell osmotic fragility appeared in the plasma of A and AR tumor bearers. Later, these compounds disappeared from the plasma of A tumor bearers but slightly increased in the plasma of AR tumor bearers. Furthermore, by day 10, compounds precipitating between 60 and 80% (NH4)2SO4 and with similar effects appeared only in plasma of AR tumor bearers. The salt solubility, production kinetics and hemolytic activity of these compounds resemble those of the immunoglobulins. This, together with their preferential increase in rats bearing the AR variant, suggest their association with an immune response against this tumor.