TreeKDE: clustering multivariate data based on decision tree and using one-dimensional kernel density estimation.

In this paper, we present an algorithm for clustering multidimensional data, which we named TreeKDE. It is based on a tree structure decision associated with the optimization of the one-dimensional kernel density estimator function constructed from the orthogonal projections of the data on the coordinate axes. Among the main features of the proposed algorithm, we highlight the automatic determination of the number of clusters and their insertion in a rectangular region. Comparative numerical experiments are presented to illustrate the performance of the proposed algorithm and the results indicate that the TreeKDE is efficient and competitive when compared to other algorithms from the literature. Features such as simplicity and efficiency make the proposed algorithm an attractive and promising research field, which can be used as a basis for its improvement, and also for the development of new clustering algorithms based on the association between decision tree and kernel density estimator.

Relations between soil attributes and the abundance of Bacillus thurigiensis in the Cerrado of Maranhão state, Brazil.

The influence of abiotic factors on the abundance of microorganism populations in soil has been sparsely studied, especially regarding Bacillus thuringiensis (Bt) bacteria. Therefore, this research was aimed at analyzing the relationship between the chemical and textural characteristics of the soil of the Cerrado (savanna) of Maranhão State on the abundance of Bacillus thuringiensis. Soil samples were collected in different municipalities in eastern Maranhão: São Mateus do Maranhão, Alto Alegre, Coroatá, Timbiras and Codó. The soil samples were obtained in the 0-0.1 m layer for soil fertility and texture analysis. Then, in the same area for the isolation of Bt, 1 g of soil was collected. The colonies obtained in the isolation that featured morphological characteristics of Bacillus spp. were visualized under phase contrast microscopy. Principal component analysis, clustering and correlations were peformed. Results: The sand content correlated positively with the Bacillus thuringiensis index (iBt). The cluster analysis allowed for verifying that the soils not showed iBt in function of high concentrations of aluminum (Al) and potential acidity (H+Al). Considering as these attributes (Al and H+Al) alter the availability of P in the soil, the abundance of Bacillus thuringiensis may have been impaired by the deficiency of this element in the environment. Conclusion: Bt has correlations with soil texture, and high concentrations of aluminum and potential acidity in the soil influencing the permanence of Bacillus thuringiensis in Maranhão eastern Cerrado.

MulticlusterKDE: a new algorithm for clustering based on multivariate kernel density estimation.

In this paper, we propose the MulticlusterKDE algorithm applied to classify elements of a database into categories based on their similarity. MulticlusterKDE is centered on the multiple optimization of the kernel density estimator function with multivariate Gaussian kernel. One of the main features of the proposed algorithm is that the number of clusters is an optional input parameter. Furthermore, it is very simple, easy to implement, well defined and stops at a finite number of steps and it always converges regardless of the data set. We illustrate our findings by implementing the algorithm in R software. The results indicate that the MulticlusterKDE algorithm is competitive when compared to K-means, K-medoids, CLARA, DBSCAN and PdfCluster algorithms. Features such as simplicity and efficiency make the proposed algorithm an attractive and promising research field that can be used as basis for its improvement and also for the development of new density-based clustering algorithms.

Biological behavior of magnesium-substituted hydroxyapatite during bone repair / Comportamento biológico de hidroxiapatita substituída com magnésio durante o reparo ósseo

Abstract The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.

Resumo O objetivo deste estudo foi analisar o comportamento biológico de microesferas de hidroxiapatita (HA) substituída com magnésio (Mg) durante o reparo de defeito ósseo crítico, tendo em vista que este íon é de grande interesse clínico, pois está intimamente associado à homeostasia e à mineralização óssea. Para tanto, utilizou-se 30 ratos para compor três grupos experimentais: GI - defeito ósseo preenchido com microesferas de HA; GII - defeito ósseo preenchido com microesferas de HA substituída com Mg; GIII (controle) - defeito ósseo vazio; avaliados nos pontos biológicos de 15 e 45 dias. Os resultados histológicos evidenciaram, aos 15 dias, discreto infiltrado inflamatório crônico e neoformação óssea restrita às bordas, em todos os grupos. Nos grupos GI e GII, os biomateriais mantiveram-se íntegros e circundados por tecido conjuntivo frouxo. Aos 45 dias, notou-se resposta inflamatória do tipo crônica granulomatosa discreta nos grupos GI e GII, e no GIII presença escassa de células inflamatórias mononucleares. As microesferas implantadas no GI e GII mantiveram-se, em sua maioria, íntegras e envolvidas por tecido conjuntivo fibroso. Notou-se discreta neoformação óssea próxima às bordas e circunjacente a algumas microesferas. No GIII, a mineralização limitou-se às bordas e a área remanescente foi preenchida por tecido conjuntivo fibroso. Conclui-se que os biomateriais foram biocompatíveis, bioativos, osteocondutores e apresentaram biodegradação lenta, indicando seu grande potencial para em aplicações clínica como biomaterial de preenchimento.

Biological behavior of magnesium-substituted hydroxyapatite during bone repair.

The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.

Rheumatic Heart Disease: Pathogenesis and Vaccine.

Rheumatic fever (RF) and rheumatic heart disease (RHD) follow untreated S. pyogenes throat infections in children who present susceptible genes that favor the development of autoimmune reactions. In this review, we focus on the genes that confer susceptibility and on the autoimmune reactions that occur due to molecular mimicry between human-tissue proteins and streptococcal M protein. Polyarthritis is the initial manifestation, which can evolve to carditis and severe valve damage; these culminate in rheumatic heart disease (RHD) or Sydenham's chorea, which affects the central nervous system. A perspective on vaccine development to prevent the disease is also discussed.

Population genetics of reef coral endosymbionts (Symbiodinium, Dinophyceae).

Symbiodinium is a diverse genus of unicellular dinoflagellate symbionts associating with various marine protists and invertebrates. Although the broadscale diversity and phylogenetics of the Symbiodinium complex is well established, there have been surprisingly few data on fine-scale population structure and biogeography of these dinoflagellates. Yet population-level processes contribute strongly to the biology of Symbiodinium, including how anthropogenic-driven global climate change impacts these symbionts and their host associations. Here, we present a synthesis of population-level characteristics for Symbiodinium, with an emphasis on how phylogenetic affinities, dynamics within and among host individuals, and a propensity towards clonality shape patterns on and across reefs. Major inferences include the following: (i) Symbiodinium populations within individual hosts are comprised mainly of cells belonging to a single or few genetic clones. (ii) Symbiont populations exhibit a mixed mode of reproduction, wherein at least one sexual recombination event occurs in the genealogy between most genotypes, but clonal propagation predominates overall. (iii) Mutualistic Symbiodinium do not perpetually persist outside their hosts, instead undergoing turnover and replacement via the continuous shedding of viable clonal cells from host individuals. (iv) Symbiont populations living in the same host, but on different reefs, are often genetically subdivided, suggesting low connectivity, adaptation to local conditions, or prolific asexual reproduction and low effective population sizes leading to disproportionate success within and among hosts. Overall, this synthesis forms a basis for future investigations of coral symbiosis ecology and evolution as well as delimitation of species boundaries in Symbiodinium and other eukaryotic microorganisms.

Biological behavior of magnesium-substituted hydroxyapatite during bone repair

Abstract The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.

Resumo O objetivo deste estudo foi analisar o comportamento biológico de microesferas de hidroxiapatita (HA) substituída com magnésio (Mg) durante o reparo de defeito ósseo crítico, tendo em vista que este íon é de grande interesse clínico, pois está intimamente associado à homeostasia e à mineralização óssea. Para tanto, utilizou-se 30 ratos para compor três grupos experimentais: GI - defeito ósseo preenchido com microesferas de HA; GII - defeito ósseo preenchido com microesferas de HA substituída com Mg; GIII (controle) - defeito ósseo vazio; avaliados nos pontos biológicos de 15 e 45 dias. Os resultados histológicos evidenciaram, aos 15 dias, discreto infiltrado inflamatório crônico e neoformação óssea restrita às bordas, em todos os grupos. Nos grupos GI e GII, os biomateriais mantiveram-se íntegros e circundados por tecido conjuntivo frouxo. Aos 45 dias, notou-se resposta inflamatória do tipo crônica granulomatosa discreta nos grupos GI e GII, e no GIII presença escassa de células inflamatórias mononucleares. As microesferas implantadas no GI e GII mantiveram-se, em sua maioria, íntegras e envolvidas por tecido conjuntivo fibroso. Notou-se discreta neoformação óssea próxima às bordas e circunjacente a algumas microesferas. No GIII, a mineralização limitou-se às bordas e a área remanescente foi preenchida por tecido conjuntivo fibroso. Conclui-se que os biomateriais foram biocompatíveis, bioativos, osteocondutores e apresentaram biodegradação lenta, indicando seu grande potencial para em aplicações clínica como biomaterial de preenchimento.

Multifunctional catalysts based on carbon nanotubes and titanate nanotubes for oxidation of organic compounds in biphasic systems.

Amphiphilic catalysts composed of carbon nanotubes (CNTs) and titanate nanotubes (TiNTs) have been successfully synthesized by refluxing anatase TiO2 and functionalised CNTs in concentrated NaOH solution. The prepared materials were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis (TGA), and N2 physisorption isotherms. The catalytic activity of the synthesized composites was first evaluated in the oxidation of methyl yellow (MY) using H2O2 as oxidant in a single liquid phase system and in a biphasic water/oil mixture. The results of these experiments indicated that the catalytic activities of nanocomposites were very similar in the single liquid-phase oxidation. However, the modification of TiNTs with CNTs led to a substantially enhanced MY oxidation in the biphasic system. The nanocomposites show excellent interaction with both hydrophilic and hydrophobic compounds and thus stabilise emulsions. Under biphasic conditions, the catalysts can be easily separated and recycled, retaining catalytic activity even after eight runs. Additionally, the hybrid materials show superior catalytic activity and selectivity in the biphasic oxidation of benzyl alcohol with H2O2, as compared to pure TiNTs.

Mini-Review: Monosomy 1p36 syndrome: reviewing the correlation between deletion sizes and phenotypes.

The major clinical features of monosomy 1p36 deletion are developmental delay and hypotonia associated with short stature and craniofacial dysmorphisms. The objective of this study was to review the cases of 1p36 deletion that was reported between 1999 and 2014, in order to identify a possible correlation between the size of the 1p36-deleted segment and the clinical phenotype of the disease. Scientific articles published in the (National Center for Biotechnology Information; NCBI http://www.ncbi.nlm.nih.gov/pubmed) and Scientific Electronic Library Online (www.scielo.com.br) databases were searched using key word combinations, such as "1p36 deletion", "monosomy 1p36 deletion", and "1p36 deletion syndrome". Articles in English or Spanish reporting the correlation between deletion sizes and the respective clinical phenotypes were retrieved, while letters, reviews, guidelines, and studies with mouse models were excluded. Among the 746 retrieved articles, only 17 (12 case reports and 5 series of cases), comprising 29 patients (9 males and 20 females, aged 0 months (neonate) to 22 years) bearing the 1p36 deletions and whose clinical phenotypes were described, met the inclusion criteria. The genotype-phenotype correlation in monosomy 1p36 is a challenge because of the variability in the size of the deleted segment, as well as in the clinical manifestations of similar size deletions. Therefore, the severity of the clinical features was not always associated with the deletion size, possibly because of the other influences, such as stochastic factors, epigenetic events, or reduced penetration of the deleted genes.

A systematic review of the intergenerational aspects and the diverse genetic profiles of Huntington's disease.

Huntington's disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, characterized by movement and personality disorders and by progressive dementia. Its prevalence varies by ethnic origin and different genetic profiles predisposing individuals to HD in each population. The prevalence of HD is 5-10 per 100,000 individuals in Caucasian populations of North America and Western Europe. It is an autosomal dominant disease associated with the expansion of CAG-type repetitive DNA sequences in the HTT gene. This gene, located on the short arm of chromosome 4, encodes the protein huntingtin. In this study, we reviewed 17 articles about HD that report data from 2400 affected individuals from various countries around the world, including Venezuela, China, Croatia, Turkey, Germany, Italy, Brazil, Spain, Taiwan, India, the Netherlands, Russia, and the USA, with a focus on genetic profiles and intergenerational expansions or contractions of expanded alleles responsible for causing HD. We discuss the genetic characteristics of HD in different populations and any atypical cases reported in these studies.

Genetic population structure of an anchialine shrimp, Metabetaeus lohena (Crustacea: Alpheidae), in the Hawaiian Islands.

Anchialine habitats in the Hawaiian Islands, characterized as coastal bodies of land-locked salt or brackish water that fluctuate with the tides due to subterranean connections, are the only ecosystems of this type found within the United States. These habitats are currently subject to anthropogenic impacts that threaten their future existence. Previous research has shown strong genetic population structure of an endemic atyid shrimp, Halocaridina rubra, in these habitats. The native alpheid shrimp, Metabetaeus lohena, whose known range entirely overlaps that of H. rubra, has feeding and reproductive behaviors that are biologically distinct from H. rubra. Its historic scarcity and status as a candidate for the US Fish and Wildlife Department's Endangered Species List, make M. lohena an ideal species to compare against the known genetic structure of H. rubra. We investigated the population structure of this native anchialine shrimp to test the hypothesis that genetic population structure differs between the two shrimp species and that M. lohena is genetically unstructured across its range. A survey of 605 bp of the mitochondrial cytochrome c oxidase subunit I (COI) gene from 127 individuals collected at 7 sites spanning the islands of O'ahu, Maui and Hawaii revealed 43 haplotypes. The most common haplotype was represented in similar proportions from all sites sampled, accounting for 44% of the surveyed sequences. Analyses of molecular variation (AMOVA), pairwise PhiST values, Bayesian estimates of migration (M), Mantel tests and Nested Clade Analyses (NCAs) all failed to reveal evidence of major barriers to gene flow among most populations separated by inter-island channels. This lack of genetic structure in M. lohena is found to be in stark contrast with the highly structured population of H. rubra, and may be attributed to oceanic dispersal strategies and/or a recent introduction to the Hawaiian Islands.

Genetic population structure of an anchialine shrimp, Metabetaeus lohena (Crustacea: Alpheidae), in the Hawaiian Islands

Anchialine habitats in the Hawaiian Islands, characterized as coastal bodies of land-locked salt or brackish water that fluctuate with the tides due to subterranean connections, are the only ecosystems of this type found within the United States. These habitats are currently subject to anthropogenic impacts tha t threaten their future existence. Previous research has shown strong genetic population structure of an endemic atyid shrimp, Halocaridina rubra, in these habitats. The native alpheid shrimp, Metabetaeus lohena, whose known range entirely overlaps that of H. rubra, has feeding and reproductive behaviors that are biologically distinct from H. rubra. Its historic scarcity and status as a candidate for the US Fish and Wildlife Department’s Endangered Species List, make M. lohena an ideal species to compare against the known genetic structure of H. rubra. We investigated the population structure of this native anchialine shrimp to test the hypothesis that genetic population structure differs between the two shrimp species and that M. lohena is genetically unstructured across its range. A survey of 605 bp of the mitochondrial cytochrome c oxidase subunit I (COI) gene from 127 individuals collected at 7 sites spanning the islands of O’ahu, Maui and Hawaii revealed 43 haplotypes. The most common haplotype was represented in similar proportions from all sites sampled, accounting for 44% of the surveyed sequences. Analyses of molecular variation (AMOVA), pairwise ΦST values, Bayesian estimates of migration (M), Mantel tests and Nested Clade Analyses (NCAs) all failed to reveal evidence of major barriers to gene flow among most populations separated by inter-island channels. This lack of genetic structure in M. lohena is found to be in stark contrast with the highly structured population of H. rubra, and may be attributed to oceanic dispersal strategies and/or a recent introduction to the Hawaiian Islands. Rev. Biol. Trop. 58 (1): 159-170. Epub 2010 March 01.

Los hábitats de los alfeidos de las islas de Hawaii, se caracterizan por ser zonas cerradas de aguas saladas o salobres, que fluctúan con las mareas, debido a las conexiones subterráneas, son los únicos ecosistemas de este tipo que se encuentran en Estados Unidos. Estos hábitats actualmente están sujetos a impactos antropogénicos que amenazan su existencia futura. La investigación anterior ha demostrado una fuerte estructura genética de una población de camarones atíidos endémicos, Halocaridina rubra, en estos hábitats. El camarón alfeido nativo, Metabetaeus lohena, cuya área de distribución conocida se superpone totalmente con la de H. rubra, tiene comportamientos alimenticios y reproductivos que son biológicamente diferentes a los de H. rubra. Su escasez histórica y su condición de candidato para aparecer en la Lista de Especies en Peligro del Departamento de Pesca y Vida Silvestre de Estados Unidos, hace de M. lohena una especie ideal para comparar su estructura genética con la de H. rubra. Se investigó la estructura de la población de este camarón alfeido nativo para probar la hipótesis que la estructura genética de la población difiere entre las dos especies y que la de M. lohena está genéticamente no estructurada en todo su ámbito. El análisis de 605 pb de la oxidasa mitocondrial citocromo c subunidad I (COI) de genes de 127 individuos recolectados en 7 sitios que abarcan las islas de Oahu, Maui y Hawaii reveló 43 haplotipos. El haplotipo más común fue representado en proporciones similares en todos los sitios incluidos en la muestra, de acuerdo al 44% de las secuencias estudiadas. El análisis de variación molecular (AMOVA), los valores de ΦST pareados, la estimación bayesiana de la migración (M), las pruebas de Mantel y los Análisis Cladísticos no pudieron revelar la existencia de importantes barreras al flujo genético entre las poblaciones más separadas por los canales entre las islas. La falta de estructura genética en M. lohena contrasta con la muy estructurada población de H. rubra, y puede ser atribuida a las estrategias de dispersión oceánica y/o una introducción reciente en las islas hawaianas.

Effect of cardiopulmonary bypass on the pharmacokinetics of propranolol and atenolol

The pharmacokinetics of some β-blockers are altered by cardiopulmonary bypass (CPB). The objective of this study was to compare the effect of coronary artery bypass graft (CABG) surgery employing CPB on the pharmacokinetics of propranolol and atenolol. We studied patients receiving oral propranolol with doses ranging from 80 to 240 mg (N = 11) or atenolol with doses ranging from 25 to 100 mg (N = 8) in the pre- and postoperative period of CABG with moderately hypothermic CPB (32°C). On the day before and on the first day after surgery, blood samples were collected before β-blocker administration and every 2 h thereafter. Plasma levels were determined using high-performance liquid chromatography and data were treated by pharmacokinetics-modelling. Statistical analysis was performed using ANOVA or the Friedman test, as appropriate, and P < 0.05 was considered to be significant. A prolongation of propranolol biological half-life from 5.41 ± 0.75 to 11.46 ± 1.66 h (P = 0.0028) and an increase in propranolol volume of distribution from 8.70 ± 2.83 to 19.33 ± 6.52 L/kg (P = 0.0032) were observed after CABG with CPB. No significant changes were observed in either atenolol biological half-life (from 11.20 ± 1.60 to 11.44 ± 2.89 h) or atenolol volume of distribution (from 2.90 ± 0.36 to 3.83 ± 0.72 L/kg). Total clearance was not changed by surgery. These CPB-induced alterations in propranolol pharmacokinetics may promote unexpected long-lasting effects in the postoperative period while the effects of atenolol were not modified by CPB surgery.

Effect of cardiopulmonary bypass on the pharmacokinetics of propranolol and atenolol.

The pharmacokinetics of some beta-blockers are altered by cardiopulmonary bypass (CPB). The objective of this study was to compare the effect of coronary artery bypass graft (CABG) surgery employing CPB on the pharmacokinetics of propranolol and atenolol. We studied patients receiving oral propranolol with doses ranging from 80 to 240 mg (N = 11) or atenolol with doses ranging from 25 to 100 mg (N = 8) in the pre- and postoperative period of CABG with moderately hypothermic CPB (32 degrees C). On the day before and on the first day after surgery, blood samples were collected before beta-blocker administration and every 2 h thereafter. Plasma levels were determined using high-performance liquid chromatography and data were treated by pharmacokinetics-modelling. Statistical analysis was performed using ANOVA or the Friedman test, as appropriate, and P < 0.05 was considered to be significant. A prolongation of propranolol biological half-life from 5.41 +/- 0.75 to 11.46 +/- 1.66 h (P = 0.0028) and an increase in propranolol volume of distribution from 8.70 +/- 2.83 to 19.33 +/- 6.52 L/kg (P = 0.0032) were observed after CABG with CPB. No significant changes were observed in either atenolol biological half-life (from 11.20 +/- 1.60 to 11.44 +/- 2.89 h) or atenolol volume of distribution (from 2.90 +/- 0.36 to 3.83 +/- 0.72 L/kg). Total clearance was not changed by surgery. These CPB-induced alterations in propranolol pharmacokinetics may promote unexpected long-lasting effects in the postoperative period while the effects of atenolol were not modified by CPB surgery.

Toxicological and phytochemical studies of Aspidosperma subincanum Mart. stem bark (Guatambu).

Aspidosperma subincanum Mart. is widely used in Brazilian folk medicine to treat digestive disorders. In this study, acute and subchronic toxicity and cytotoxicity of stem bark ethanolic extract of Aspidosperma subincanum (EEAs) have been evaluated. In addition, phytochemical analysis was performed. The EEAs had low acute toxicity in mice with LD50 =1129 +/- 154mg/kg p.o. and 397 +/- 15 mg/kg i.p. The LC50 was 1340 +/- 428 microg/mL in the brine shrimp assay. There was no relevance of serious changes in behavioral, hematological and biochemical parameters and no deleterious effect on vital organs of rats that resulted after 30 days daily exposure to 5 and 100 mg/kg of EEAs. Phytochemical analysis of stem bark of A. subincanum revealed the presence of indole alkaloids, saponins, terpenoids, steroids and tannins and resulted in the isolation of oleic acid and guatambuine as major constituents. Using the method of the dose by factor approach, the human safe dose was 210 mg/70 kg/day. The EEAs appears to be safe and non-toxic in low doses in rodents and domestic preparations used by population have relatively security.

Simultaneous determination of cefepime, vancomycin and imipenem in human plasma of burn patients by high-performance liquid chromatography.

A liquid chromatographic method with UV detection for simultaneous determination of cefepime, vancomycin and imipenem has been developed. Cefuroxime was used as internal standard. After the clean up of samples by plasma protein precipitation, 5 microl of the extract were injected into the chromatograph and peaks were eluted from the Sulpelcosil LC-18 column using a mobile phase consisting of 0.075 M acetate buffer:acetonitrile (92:8, v/v), pH 5.0 at low rate (0.8 ml/min). The detection wavelength was 230 nm. The limit of detection was 0.4 microg/ml for cefepime and 0.2 microg/ml for vancomycin and imipenem. The method was applied to plasma samples of burn patients, and only small volumes of plasma were required for the simultaneous determination of those antimicrobial agents.

Urgency priority in kidney transplantation in Rio Grande do Sul.

In 2002, it was established a system of urgency priority for kidney transplantations in cases with no vascular or peritoneal access for dialysis. The aims of this article are to describe the system in the organ donation and procurement agency (CNCDO) as well as to show the results to date. We reviewed cases of urgency priority request for kidney transplantation addressed to the CNCDO from May 2002 to August 2005. Within this period the CNCDO received 35 urgency priority requests for kidney transplantation (mean, 1 every 1.2 months). Thirty-one (88%) were accepted as urgent, and only 4 (11%) were refused. Among the 31 accepted, 26 (83%) had the transplantation performed in an average time of 19.6 days (range, 1-90), representing only 3.2% of all cadaveric kidney transplantations during that period.

Primary culture of the region of the amebocyte-producing organ of the snail Biomphalaria glabrata, the intermediate host of Schistosoma mansoni.

Biomphalaria glabrata snails are major hosts for the digenetic trematoda Schistosoma mansoni, the causative agent of human schistosomiasis. The success or failure of the infection will be dependent on the mobilization of the molluskan internal defense system, where a major role will be played by circulating hemocytes produced by the APO (amebocyte-producing organ) of the snail. In this report, the primary culture of the APO region of B. glabrata was obtained for the first time, as well as a control culture of the ovotestis. Three different cell populations migrated easily from the explants in culture, with no need of any dispersion agent. The cells grew in suspension at an incubation temperature of 15 degrees C and the cultures were maintained viable for up to two weeks. Two of these cell populations obtained resembled cell types known to be present in the hemolymph of Biomphalaria. The availability of APO cells in culture may contribute to a better understanding of the internal defense in mollusks, in general, as well as the specific response of B. glabrata to S. mansoni infection.

Primary culture of the region of the amebocyte-producing organ of the snail Biomphalaria glabrata, the intermediate host of Schistosoma mansoni

Biomphalaria glabrata snails are major hosts for the digenetic trematoda Schistosoma mansoni, the causative agent of human schistosomiasis. The success or failure of the infection will be dependent on the mobilization of the molluskan internal defense system, where a major role will be played by circulating hemocytes produced by the APO (amebocyte-producing organ) of the snail. In this report, the primary culture of the APO region of B. glabrata was obtained for the first time, as well as a control culture of the ovotestis. Three different cell populations migrated easily from the explants in culture, with no need of any dispersion agent. The cells grew in suspension at an incubation temperature of 15°C and the cultures were maintained viable for up to two weeks. Two of these cell populations obtained resembled cell types known to be present in the hemolymph of Biomphalaria. The availability of APO cells in culture may contribute to a better understanding of the internal defense in mollusks, in general, as well as the specific response of B. glabrata to S. mansoni infection.