Efeito do extrato aquoso e etanólico do angico preto sobre larvas de Rhipicephalus (Boophilus) microplus / The effect of aqueous and ethanolic extracts from the angico Preto about larvae of Rhipicephalus (Boophilus) microplus

Rhipicephalus (Boophilus) microplus representa um grande problema na bovinocultura e o uso de acaricidas é a medida de controle profilático e terapêutico mais comum contra esses ectoparasitos. Os principais problemas relacionados com essa prática dizem respeito ao desenvolvimento de linhagens resistentes de carrapatos. Assim, objetivou-se determinar o efeito de extratos da casca de Anadenanthera macrocarpa sobre as larvas de R. (B.) microplus, obtidas de um pool de ovos, acondicionadas em tubo de polietileno. De acordo com os resultados, o extrato aquoso na concentração de 8,26mg.mL-1 causou 85% de mortalidade nas primeiras 12 horas. Quanto ao extrato etanólico, observou-se maior mortalidade nas concentrações 12,5; 6,25 e 1,56mg.mL-1, em torno de 84%, percentuais semelhantes ao amitraz. Os controles negativos não apresentaram mortalidade durante o experimento. Assim, tanto o extrato aquoso como o extrato etanólico apresentaram efeito larvicida, embora o extrato etanólico tenha sido mais eficiente para a espécie, podendo ser uma alternativa no controle desse ectoparasito.

Rhipicephalus (Boophilus) microplus represents a major problem in cattle breeding and the use of acaricides is the most common prophylactic and therapeutic control measure against these ectoparasites. The main problems with this practice relate to the development of resistant strains of ticks. Thus, the objective was to determine the effect of bark extracts from Anadenanthera macrocarpa on the larvae of R.(B.) microplus, obtained from a pool of eggs packed in a polyethylene tube. According to the results, the aqueous extract at a concentration of 8.26mg.mL-1caused 85% mortality in the first 12 hours. As for the ethanolic extract, higher mortality of about 84%, a percentage similar to amitraz, was observed at concentrations of 12.5mg.mL-1, 6.25mg.mL-1 and 1.56mg.mL-1. The negative controls showed no mortality during the experiment. Thus, both the aqueous and ethanolic extracts showed larvicidal activity, although the ethanolic extract has been more efficient and could be an alternative to control this ectoparasite.

Relationships between dendritic morphology, spatial distribution and firing patterns in rat layer 1 neurons

The cortical layer 1 contains mainly small interneurons, which have traditionally been classified according to their axonal morphology. The dendritic morphology of these cells, however, has received little attention and remains ill defined. Very little is known about how the dendritic morphology and spatial distribution of these cells may relate to functional neuronal properties. We used biocytin labeling and whole cell patch clamp recordings, associated with digital reconstruction and quantitative morphological analysis, to assess correlations between dendritic morphology, spatial distribution and membrane properties of rat layer 1 neurons. A total of 106 cells were recorded, labeled and subjected to morphological analysis. Based on the quantitative patterns of their dendritic arbor, cells were divided into four major morphotypes: horizontal, radial, ascendant, and descendant cells. Descendant cells exhibited a highly distinct spatial distribution in relation to other morphotypes, suggesting that they may have a distinct function in these cortical circuits. A significant difference was also found in the distribution of firing patterns between each morphotype and between the neuronal populations of each sublayer. Passive membrane properties were, however, statistically homogeneous among all subgroups. We speculate that the differences observed in active membrane properties might be related to differences in the synaptic input of specific types of afferent fibers and to differences in the computational roles of each morphotype in layer 1 circuits. Our findings provide new insights into dendritic morphology and neuronal spatial distribution in layer 1 circuits, indicating that variations in these properties may be correlated with distinct physiological functions.

Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37) on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 æm ("thin" or "thick" dendrites, respectively). Three cells (4.5 percent) were bistratified, having thick dendrites, and the others (95.5 percent) were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40 percent) and 2 groups with inner (50-100 percent) stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

Proteinase inhibition using small Bowman-Birk-type structures

Bowman-Birk inhibitors (BBIs) are cysteine-rich and highly cross-linked small proteins that function as specific pseudosubstrates for digestive proteinases. They typically display a "double-headed" structure containing an independent proteinase-binding loop that can bind and inhibit trypsin, chymotrypsin and elastase. In the present study, we used computational biology to study the structural characteristics and dynamics of the inhibition mechanism of the small BBI loop expressing a 35-amino acid polypeptide (ChyTB2 inhibitor) which has coding region for the mutated chymotrypsin-inhibitory site of the soybean BBI. We found that in the BBI-trypsin inhibition complex, the most important interactions are salt bridges and hydrogen bonds, whereas in the BBI-chymotrypsin inhibition complex, the most important interactions are hydrophobic. At the same time, ChyTB2 mutant structure maintained the individual functional domain structure and excellent binding/inhibiting capacities for trypsin and chymotrypsin at the same time. These results were confirmed by enzyme-linked immunosorbend assay experiments. The results showed that modeling combined with molecular dynamics is an efficient method to describe, predict and then obtain new proteinase inhibitors. For such study, however, it is necessary to start from the sequence and structure of the mutant interacting relatively strongly with both trypsin and chymotrypsin for designing the small BBI-type inhibitor against proteinases.

Comparação de quatro métodos laboratoriais para diagnóstico da Giardia lamblia em fezes de crianças residentes em Belém, Pará / Comparison of 4 techniques for the diagnosis of Giardia lamblia in stool of children from Belém city, Pará State, Brazil

We report the evaluation of four techniques for Giardia lamblia diagnosis in children's stool. The Iron haematoxilin staining and direct examination with lugol showed lower positivity, while the method of Faust et al. Continues to be a good option for G. lamblia diagnosis and Immunoenzymatic assay increases the detection of this parasite.

Relatamos a comparação de quatro metodologias para o diagnóstico da Giardia lamblia em material fecal de crianças, Belém/PA. A Hematoxilina Férrica e o método direto apresentaram menor positividade, enquanto que o Método de Faust continua uma boa escolha para o diagnóstico e o Ensaio imunoenzimático melhora a qualidade da detecção deste parasito.

Cirurgia reconstrutiva e angioplastia no tratamento de nove doentes portadores de oclusöes crônicas das artérias subclávias / Reconstrutive surgery and percutaneous angioplasty in the tratment of nine patients with chronic subclavian artery occlusion

A proposta deste estudo foi apresentar uma série de pacientes com doença oclusiva da artéria subclávia tratados por procedimento cirúrgico ou angioplastia. Durante um período de cinco anos, nove pacientes com idade média de 54 anos foram submetidos a seis derivaçöes carótidas-subclávias, uma endarterectomia e duas angioplastias. Os resultados clínicos foram inteiramente satisfatórios em quatro pacientes com sintomas cerebrais, em dois com isquemia de membro e em dois dos três com sintomas mistos. Um paciente faleceu e dois foram perdidos para seguimento. As reconstruçöes permaneceram pérvicas em cinco pacientes entre 12 e 28 meses de seguimento de seguimento mas ocluiu em outro. A revascularizaçäo das artérias subclávia é efetiva tanto com procedimentos cirúrgicos como com a angioplastia.

Histochemical characterization of NADPH-diaphorase activity in area 17 of diurnal and nocturnal primates and rodents

NADPH-diaphorase (NADPH-d) activity was studied comparatively in area 17 of four mammalian species, two primates and two rodents. Three brain hemispheres each from adult capuchin-monkeys, owl-monkeys, agoutis and guinea pigs were fixed with aldehyde fixatives by perfusion and 200 mum sections were submitted to NADPH-d histochemistry, using the indirect malic enzyme method. In all species studied the neuropil pattern of enzyme activity presented a clear layered appearance. In primates, histochemical staining was most intense in layer IVc, while in rodents the highest intensity of the neuropil reaction was in supragranular layers (II and III). Comparison of cell density in grey and white matter showed that the majority of NADPH-d-positive neurones were located in the white matter of primates but not of rodents. Since NADPH-d is a nitric oxide synthase the results are very important for comparative functional studies of neuromediators and their correlations with laminar and modular organization of area 17 of the mammalian brain.

Head holder for lateral-eyed species in vision research

The present report describes a head holder designed to be used for lateral-eyed species in vision research. The head-holder employs a prosthesis implanted on the skull and provides for adjustable movements in different planes, thus allowing precise positioning of the eye with respect to the visual space

Bacillus licheniformis IOC 2390 (ATCC 33632), nova amostra produtora de bacitracina. / Bacillus licheniformis IOC 2390 (ATCC 33632), a new bacitracin producer strain

O antibiotico excretado pelo Bacillus licheniformis IOC 2390 (ATCC 33632), foi analisado, em seguida a sua extracao do meio de producao con n-butanol. Concentrados aquosos finais (Fracao III), submetidos a filtracao por colunas de Sephadex G-25, mostratam tres componentes com identidades de peso molecular (i.e., mesmo volume de eluicao com picos em A252nm e atividade antibiotica) e de perfil cromatografico com o grupo das bacitracinas