Animal performance and nutritional characteristics of Piatã-grass in integrated systems / Desempenho animal e características nutricionais de capim-piatã em sistemas integrados

The objective was to evaluate animal performance and nutritional characteristics of Brachiaria brizantha cv. BRS Piatã in two integrated systems, during the summer and winter, five years after the initial establishment of the area. The randomized block experimental design was adopted with treatments consisting of a control (five native trees per hectare) and an integrated crop-livestock-forestry (ICLF) system with 227 eucalyptus trees per hectare. Animal performance, canopy height, soil cover, forage mass (leaf, stem and senescent material), and forage nutritive value were evaluated. Differences between systems were observed in forage mass (total, leaf, stem and senescent material), soil cover and forage nutritive value in both seasons. Shading conditions provided by eucalyptus in the ICLF system lead to a reduction in forage mass and neutral detergent fiber content, and to an increase in crude protein and in vitro organic matter digestibility. However, no effect on animal performance was obtained. The presence of trees improves the forage nutritive value without impacting animal performance in integrated systems.(AU)

O objetivo foi avaliar o desempenho animal e as características nutricionais de Brachiaria brizantha cv. BRS Piatã em dois sistemas integrados, durante o verão e o inverno, cinco anos após o estabelecimento inicial da área. O delineamento experimental em blocos ao acaso foi adotado com tratamentos constituídos por um controle (cinco árvores nativas por hectare) e um sistema integrado lavoura-pecuária-floresta (ILPF) com 227 eucaliptos por hectare. Desempenho animal, altura do dossel, cobertura do solo, massa de forragem (folha, caule e material senescente) e valor nutritivo da forragem foram avaliados. Diferenças entre os sistemas foram observadas na massa de forragem (total, foliar, caule e material senescente), na cobertura do solo e no valor nutritivo da forragem em ambas as estações. As condições de sombreamento proporcionadas pelo eucalipto no sistema ICLF levaram a uma redução na massa de forragem e no teor de fibra em detergente neutro e a um aumento na proteína bruta e na digestibilidade in vitro da matéria orgânica. No entanto, nenhum efeito no desempenho animal foi obtido. A presença de árvores melhora o valor nutritivo da forragem, sem impactar o desempenho animal em sistemas integrados.(AU)

On the resemblance of synapse formation and CNS myelination.

The myelination of axons in the central nervous system (CNS) is essential for nervous system formation, function and health. CNS myelination continues well into adulthood, but not all axons become myelinated. Unlike the peripheral nervous system, where we know of numerous axon-glial signals required for myelination, we have a poor understanding of the nature or identity of such molecules that regulate which axons are myelinated in the CNS. Recent studies have started to elucidate cell behavior during myelination in vivo and indicate that the choice of which axons are myelinated is made prior to myelin sheath generation. Here we propose that interactions between axons and the exploratory processes of oligodendrocyte precursor cells (OPCs) lead to myelination and may be similar to those between dendrites and axons that prefigure and lead to synapse formation. Indeed axons and OPCs form synapses with striking resemblance to those of neurons, suggesting a similar mode of formation. We discuss families of molecules with specific functions at different stages of synapse formation and address studies that implicate the same factors during axon-OPC synapse formation and myelination. We also address the possibility that the function of such synapses might directly regulate the myelinating behavior of oligodendrocyte processes in vivo. In the future it may be of benefit to consider these similarities when taking a candidate-based approach to dissect mechanisms of CNS myelination.

Clinical evaluation of clonidine added to lidocaine solution for subarachnoid analgesia in sheep.

Clonidine (CL) is a alpha2-adrenergic agonist that produces analgesia in animals and humans by a non-opiate alpha2-adrenergic action in the spinal cord dorsal horn. The objective of this prospective randomized study was to investigate the clinical effects of CL/lidocaine (LD) combination administered by the subarachnoid route in sheep. Each sheep received each of three treatments, at no shorter than weekly intervals. Treatments consisted of 0.003 mg/kg CL, 1.2 mg/kg LD and a combination of CL (0.003 mg/kg) and LD (1.2 mg/kg) (CLLD). Subarachnoid injections were given in all animals between the last lumbar and first sacral vertebra. Heart rate (HR), arterial pressures, respiratory rate, rectal temperature, analgesia, sedation, and motor blockade were determined before drug administration (basal) and 5, 10, 15 and 30 min after drug administration, and at 30-min intervals until loss of analgesia occurred. The duration of analgesia after subarachnoid CLLD administration was 187 +/- 24 min (mean +/- SD), i.e. more than twice of that obtained with CL (99 +/- 19 min) or LD (55 +/- 4.4 min) alone. In all sheep, CL, administered either alone or with LD, induced moderate sedation. After subarachnoid administration of three treatments, all sheep had ataxia and subsequent sternal recumbency. The CL treatment causes decreases in blood pressure (diastolic arterial pressure and mean arterial pressure) and HR. Data suggest that the CLLD combination could be used subarachnoidally in sheep requiring prolonged surgery.

Comparative effects of maternal prenatal and postnatal exposures to astemizole on reproductive parameters of rats.

The prenatal and postnatal effects of administration of a nonsedative antihistamine H1, astemizole (ATZ), were compared. ATZ (10 mg/kg) was injected daily into female Wistar rats throughout pregnancy (prenatal treatment) or during the first 6 days of lactation (postnatal treatment). Neither treatment modified dam body weight. Prenatal exposure reduced offspring body weight and lead to a latter expression of the vaginal opening of female offspring. In addition, a long-term disruption of male reproductive behavior was observed, while female sexual behavior was not modified. The sexual activity index and the intromission frequency were increased in prenatally treated animals. Testes wet weight was reduced, but no modifications were detected in vas deferens or seminal vesicles. Postnatal treatment did not alter offspring body weight, open-field activity, sexual behavior and organ weight as well as did not delay testes descent but reduced the time until vaginal opening. Hypothalamic serotonin (5-HT), dopamine (DA) and noradrenaline (NA) as well as DA and NA metabolites were not modified by both prenatal and postnatal treatments. Increased striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels were observed after prenatal and postnatal treatments, while only postnatal 5-HT levels were increased. We propose that the present results indicate that prenatal ATZ exposure can have long-lasting organizational effects on reproductive behavior of male rats, while postnatal exposure to this drug did not alter mating behavior. In relation to female rats, prenatal and postnatal exposures to ATZ accelerated puberty but did not alter sexual behavior. Neurochemical data show that both treatments increased striatal dopaminergic system activity, suggesting a central ATZ effect after perinatal exposure.

What do category-specific semantic deficits tell us about the representation of lexical concepts?

A reassessment of category-specific semantic deficits in light of their contribution to a theory of the representation of lexical concepts is proposed. Two theories are examined: one, held by the majority of researchers in the field, claims that concepts are represented by sets of features; another, in contrast, claims that concepts are atomic representations. An analysis of category-specific semantic deficits in terms of inferential relations (of the meaning-postulates type) between atomic concepts is elaborated. It is argued that this theory can better account for the pattern of performance exhibited by patients with semantic deficits.

Ambiguous novel compounds and models of morphological parsing.

This paper reports on two experiments that investigated the activation of morphemes in English novel compounds. All experiments employed stimuli that we have called "ambiguous novel compounds." These words (e.g., clamprod) have two interpretable parses (e.g., clam + prod or clamp + rod) and thus offer an opportunity to investigate which parses are preferred, whether both possible parses are computed, and whether parsing procedures "divide" words into their morphological constituents or "extract" constituent representations. The results suggest that morphological parsing does not simply divide a word into its constituents, but rather generates multiple representations that are subsequently evaluated.

Perinatal astemizole exposure in the rat throughout gestation: long-term behavioral and anatomic effects associated with reproduction.

Astemizole (ATZ), a non-sedative antihistamine, which antagonize histamine at the level of H1 receptor, was administered daily to female Wistar rats as a 10-mg/kg dose throughout pregnancy. ATZ exposure reduced offspring body weight and delayed the pinna detachment and startle reflex without any modification of dams body weight during gestation. Long-term disruption of male reproductive behavior was seen in experimental animals, whereas female sexual behavior was not modified. In addition, no motor alterations were observed in female or males in adulthood. Testis wet weight was reduced, but no modifications were detected in vasa deferentia or seminal vesicle. We proposed that ATZ administration during pregnancy causes several effects mainly of a sexual nature by interfering either with the hormonal mechanism involved in the central nervous system masculinization or by a direct action of the drug on pups during the development.

Dot-enzyme-linked immunosorbent assay (Dot-ELISA) for detection of pneumococcal polysaccharide antigens in pleural fluid effusion samples. Comparison with bacterial culture, counterimmunoelectrophoresis and latex agglutination.

A dot-enzyme-linked immunosorbent assay (Dot-ELISA) for pneumococcal antigen detection was standardized in view of the need for a rapid and accurate immunodiagnosis of acute pneumococcal pneumonia. A total of 442 pleural fluid effusion samples (PFES) from children with clinical and laboratory diagnoses of acute bacterial pneumonia, plus 38 control PFES from tuberculosis patients and 20 negative control serum samples from healthy children were evaluated by Dot-ELISA. The samples were previously treated with 0.1M EDTA pH 7.5 at 90 degrees C for 10 min and dotted on nitrocellulose membrane. Pneumococcal omniserum diluted at 1:200 was employed in this assay for antigen detection. When compared with standard bacterial culture, counterimmunoelectrophoresis and latex agglutination techniques, the Dot-ELISA results showed relative indices of 0.940 to sensitivity, 0.830 to specificity and 0.760 to agreement. Pneumococcal omniserum proved to be an optimal polyvalent antiserum for the detection of pneumococcal antigen by Dot-ELISA. Dot-ELISA proved to be a practical alternative technique for the diagnosis of pneumococcal pneumonia.

[Physical disabilities in Hansen's disease at the time of diagnosis. I. Disability evaluation]. / Incapacidades físicas em hanseníase no momento do diagnóstico. I--Avaliação das incapacidades.

The evaluation of the physical disabilities at the moment of the hanseniasis diagnosis was carried out through the clinical and epidemiological forms of the 8,915 cases recorded in the State of São Paulo, Brazil, from 1981 to 1983. The records of the physical disabilities were studied by three different methods: the disabilities at their highest grade, the disabilities' grade index achieved from the arithmetic mean of the added values of the different disability grades, and the absolute disabilities frequency. The study suggested that the maximum grade was the best evaluation method of the physical disabilities at the moment of the diagnosis, being an important indicator for the evaluation of prevention efforts and of the hanseniasis control.

[Stable solution of fuchsin--a new method for preparation of Ziehl-Neelsen staining]. / Solução estável de fucsina--novo método de preparação para coloração de Ziehl-Neelsen.

The fuchsin salts currently available in Latin American market have shown some instability when in solution, according to the classic Ziehl-Neelsen method, resulting in a total precipitation of the salt. The authors indicate a new technique for the preparation of this solution, in order to minimize the action of interfering factors responsible for the precipitation, obtaining thus a greater solubility of the salt, as well as the solution stability. The method effectiveness is reinforced by the utilization of a smaller amount of the salt and the attainment of a larger storage period for the solution.

[Modification of the basic stain of the Ziehl-Neelsen technic in the identification of Mycobacterium leprae]. / Modificação da coloração de fundo da técnica de Ziehl-Neelsen na identificação do Mycobacterium leprae.

Authors analyse the counterstain with methylene blue solution in the usual Ziehl-Neelsen method. Considerations are made on the characteristics of the dye substance. A technique alteration is proposed: a "concomitant alkalization" of the classic aqueous methylene blue solution, by adding some drops of sodium hydroxide solution, 1:500, on the slide at the moment of the staining. By this technique it was observed: a) a larger validity period of the solution; b) an absence of precipitate in the slides; c) an easier visualization of the substrate; d) a larger contrast among the substrate and the bacilli.

Invasive strain of Escherichia coli belonging to O group 29.

A strain of Escherichia coli isolated from a child with diarrhea was biochemically similar and antigenically identical (O and K antigens) to the standard strain of E. coli O group 29 and was positive in the Serény test for invasiveness, which suggests that it can cause a Shigella-like illness.