Levedura de cana-de-açúcar spray dry na alimentação de suínos na fase de crescimento e terminação / Sugar cane spray dry yeast on growing and finishing pigs feeding

Foi estudado o valor nutricional (digestibilidade total e ileal) de duas leveduras spray dry (cana-de-açúcar - LEV35 e cerveja+cana-de-açúcar - LEV40) e o efeito da sua inclusão em rações para suínos na fase de crescimento e terminação. Os valores de ED (kcal/kg) da LEV35 e da LEV40 foram 3.496 e 3.901 e EM (kcal/kg) foram 3.475 e 3.862, respectivamente. Os valores de lisina, metionina+cistina e treonina digestível para a levedura de cana-de-açúcar e da levedura de cerveja+cana-de-açúcar são 2,66 e 2,64, 1,11 e 1,03, 1,95 e 1,92, respectivamente. No desempenho foram utilizados 40 suínos com peso inicial de 34,39± 7,57kg (crescimento) e de 62,45± 5,68kg (terminação), distribuídos em delineamento inteiramente casualizado com cinco níveis de inclusão (0, 5, 10, 15 e20%) da LEV35. Na fase de crescimento, houve piora do GDP e da CA com o aumento da inclusão. Na fase de terminação, porém, houve efeito quadrático para o CDR, sendo o melhor nível 3.32%. Da mesma forma, ocorreu piora linear para o GDP, CA, peso de carcaça quente, rendimento de carcaça fria e peso de pernil. Os resultados sugerem que a adição de níveis crescentes da LEV35 pode prejudicar o desempenho dos suínos.

The nutritional value of two spray dry yeast (sugar cane - SCYSD and brewer+sugar cane - BYSD) and their inclusion effects on growing and finishing pigs feeding was studied. The DE (kcal/kg) values for SCYSD and BYSD were 3.496 and 3.901 and for ME (kcal/kg) they were 3.475 and 3.862. The values of digestible lysine, methionine+cistine and threonine for SCYSD and BYSD were: 2.66 and 2.64%; 1.11 and 1.03%: 1.95 and 1.92%. 40 pigs with initial weight of 34.39±7.57kg (growing) and 62.45±5.68kg (finishing), allotted in a completely randomized design with five levels of SCYSD inclusion were used in the performance assay. In the growing phase, there was an impairing on DWG and F:G, however, in the finishing phase, DFI presented a quadratic effect, being 3.32% the best level and linear reduction of DWG, F:G, slaughter weight, hot carcass weight, cold carcass yield and ham weight. The results suggest that increasing levels of SCYSD may impair the performance of growing and finishing pigs.

Expression of anti-Z-DNA single chain antibody variable fragment on the filamentous phage surface

We describe the expression of an anti-Z-DNA single chain variable region antibody fragment (scFv) on a filamentous phage surface. Four vectors for phage display were constructed. Two of them are able to display multiple copies of the antibody fragment, and the others can be used to make monovalent libraries. The vectors use different promoter/leader sequences to direct the expression of the fused proteins. All were able to promote the assembly of fusion virion particles. In this paper we also show the affinity selection (biopanning) of those phage-antibodies based on the capacity of their products to recognize the antigen. We used biotinylated Z-DNA and the selection was performed in a solution phase fashion. The data presented here indicate that these vectors can be further used to construct anti-nucleic acid antibody fragment libraries that can be used to study the basis of nucleic acid-protein interaction and its role in autoimmunity mechanisms.

Changes in acidic amino acid efflux from rat brain with maturation

Our previous studies have shown a greater uptake of acidic amino acids from the blood into the brain of neonatal when compared to that of adult rats. The aim of this study is to investigate whether a developmental change exists in the brain to blood efflux of this group of amino acids. The whole brain was perfused in situ with Ringer's solution containing 14C-aspartate or 14C-glutamate for 10 min. The perfusion was then continued with 14C-free perfusate for a further 20 min and samples of jugular venous outflow were taken at 30-second intervals. The amount of radioactivity [in ln dpm] in each sample was then plotted against the sampling time, and the half-time [t1/2] for 14C-efflux was calculated. Paper chromatography of the outflow samples revealed that more than 91% of the 14C-labelled acidic amino acid present in the effluent samples for up to 30 min of perfusion was chemically intact. The t1/2 for aspartate efflux in neonatal rats was 16.16 +/- 0.76 min which was significantly slower [p < 0.05] than that for the adults, 10.06 +/- 0.46 min [means +/- SEM, n = 3 and 4]. The t1/2 for glutamate efflux was also small in the adult brain where it was 50% the value seen in the neonates. The above results indicate that the systems involved in the efflux of acidic amino acids out of the brain favour retention and increased levels of this group of amino acids in the developing brain

Interactions that regulate the helical fold in proteins

Several factors that may contribute to the stabilization of the helical structure in proteins, detected in studies made on short synthetic peptides, have been reported. Some of them are: presence of alanine or leucine, ionic-pair bonding, stabilization of the helical dipole moment by appropriate charges at the helix N- and C-caps, and aromatic interactions of amino acids located at positions i, i + 4. An analysis of 54 helical structures from 12 proteins showed that all these stabilizing factors were also present in proteins, but the influence of any of them had a different weight, according to the distribution of the hydrophobic and hydrophilic amino acid residues in the helical sequence. The role of non-sequence depending interactions in helical stability, such as presence of disulfide bridges, or bonding of helical residues to substrate and/or cofactors, was also analysed

Fisiopatologia da encefalopatia hepática: coma hepático / Fisiopatology of the hepatic encephalopathy: hepatic coma

A encefalopatia hepática é uma síndrome clínica complexa caracterizada principalmente por inibiçäo neural. É uma desordem neuropsiquiátrica evidenciada por lesöes histológicas näo específicas do sistema nervoso central. O espectro das manifestaçöes clínicas é amplo, variando desde alteraçöes do comportamento (só observado por parentes ou amigos íntimos) passando por confusäo mental, letargia, até um estado de coma. Sabe-se que existem determinados fatores que precipitam ou exacerbam a encefalopatia hepática tais como: constipaçäo, infecçöes, alcalose metabólica hipocalêmica e outros distúrbios ácidos-básicos e eletrolíticos, terapia diurética, sobrecarga proteica, diarréia, vômito, anemia, hipoxia, hemorragia, hipotensäo (e outros). Várias causas tem sido propostas para explicar a patogênese da encefalopatia hepática sem que nenhuma delas seja exclusiva, o que leva a pressumir, quase com certeza, que a sua etiologia seja multifatorial. De forma geral pode-se aceitar que a encefalopatia é secundária ao acúmulo de substâncias tóxicas no líquido extracelular devido à incapacidade do fígado lesado a remover certas substâncias do plasma, as quais tem a capacidade, direta ou indireta, de modular a funçäo do sistema nervoso central