Role of L-arginine, a substrate of nitric oxide biosynthesis, on intestinal ischemia-reperfusion in rabbits.

To study whether treatment with L-arginine (ARG), a substrate of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rabbits treated with ARG (100 mgxkg(-1), intravenously) or saline solution (SS) prior to I (60 minutes) by occlusion of superior mesenteric artery and/or during R (120 minutes). After I or I/R, 2-cm jejunal segments were isolated and mounted in an organ bath to study of neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared to the sham group, jejunal contractions were similar in I + ARG, but reduced in I + SS, I/R + SS, and I/R + ARG groups. The jejunal enteric nerves were damaged in I + SS, I/R + SS, and I/R + ARG, but not in I + ARG group, suggesting that ARG can attenuate intestinal dysfunctions due to I, but not to R.

Correlação entre a atividade sérica da ceruloplasmina e os teores sérico e hepático de cobre em novilhas Nelore / Ceruloplasmin serum activity correlation with copper serum and liver concentrations in Nelore heifers

Avaliou-se a atividade oxidativa sérica da ceruloplasmina como indicadora dos teores sérico e hepático de cobre e compararam-se dois métodos de determinação da ceruloplasmina, pelo parafenileno e pela ortodianisidina. Foram colhidas 56 amostras de soro e de fígado (biópsias hepáticas) de novilhas Nelore para determinação da atividade sérica da ceruloplasmina e da concentração de cobre. As correlações entre a concentração sérica de cobre e a atividade sérica da ceruloplasmina determinadas pelos métodos do parafemileno e da ortodianisidina foram 0,75 e 0,62, respectivamente. As correlações entre a concentração hepática de cobre e a atividade sérica da ceruloplasmina pelos métodos citados foram 0,15 e 0,12. Não foi observada correlação entre os valores séricos e hepáticos de cobre. A correlação entre determinação da atividade sérica de ceruloplasmina, que utilizou o parafenileno como substrato, e o cobre sérico foi maior do que a correlação entre esse mineral e o método que usou a ortodianisidina.

Transition from Knudsen to molecular diffusion in activity of absorbing irregular interfaces.

We investigate through molecular dynamics the transition from Knudsen to molecular diffusion transport towards two-dimensional absorbing interfaces with irregular geometry. Our results indicate that the length of the active zone decreases continuously with density from the Knudsen to the molecular diffusion regime. In the limit where molecular diffusion dominates, we find that this length approaches a constant value of the order of the system size, in agreement with theoretical predictions for Laplacian transport in irregular geometries. Finally, we show that all these features can be qualitatively described in terms of a simple random-walk model of the diffusion process.

Scaling behavior of diffusion and reaction processes in percolating porous media.

We investigate the diffusion-reaction behavior of two-dimensional pore networks at the critical percolation point. Our results indicate the existence of three distinct regimes of reactivity, determined by parameter xi[triple bond]D/(Kl2), where D is the molecular diffusivity of the reagent, K is its chemical reaction coefficient, and l is the length scale of the pore. First, when the diffusion transport is strongly limited by chemical reaction (i.e., D<>K), the flux of reagent reaches a saturation limit Phi(sat) that scales with the system size as Phi(sat) approximately L(alpha), with an exponent alpha approximately 1.89, corresponding to the fractal dimension of the sample-spanning cluster. We then show that the variation of flux Phi calculated for different network sizes at the second and third regimes can be adequately described in terms of the scaling relation, Phi approximately L(alpha)f(xi/L(z)), where the crossover exponent z approximately 2.69 is consistent with the predicted scaling law alpha=2betaz.

Freshwater snails and schistosomiasis mansoni in the State of Rio de Janeiro, Brazil: I-- Metropolitan mesoregion.

In order to elaborate a planorbid chart of the State of Rio de Janeiro a survey of freshwater gastropods in the Metropolitan Mesoregion of this State was performed and revealed the occurrence of 20 species: Antillorbis nordestensis (Lucena, 1954); Biomphalaria glabrata (Say, 1818); Biomphalaria schrammi (Crosse, 1864); Biomphalaria straminea (Dunker, 1848); Biomphalaria tenagophila (Orbigny, 1835); Burnupia sp.; Drepanotrema anatinum (Orbigny, 1835); Drepanotrema cimex (Moricand, 1839); Drepanotrema lucidum (Pfeiffer, 1839); Ferrissia sp.; Gundlachia ticaga (Marcus & Marcus, 1962); Heleobia davisi Silva & Thomé, 1985; Lymnaea columella Say, 1817; Melanoides tuberculatus (Müller, 1774); Physa cubensis Pfeiffer, 1839; Physa marmorata Guilding, 1828; Pomacea sp.; Pomacea canaliculata (Lamarck, 1822); Pomacea lineata (Spix, 1827) and Pomacea sordida (Swainson, 1823). Among the planorbid species B. tenagophila was the most frequent, occurring in all municipalities surveyed. The present study extends the distribution of B. straminea in the State of Rio de Janeiro and reports new records for A. nordestensis, B. schrammi, G. ticaga, H. davisi and the genera Burnupia and Ferrissia. An account about the current transmission areas of schistosomiasis mansoni in this Mesoregion is presented as well.

[Pharmaceutical care in primary health care: the experience of 3 Brazilian States]. / Assistência farmacêutica na atenção básica de saúde: a experiência de três estados brasileiros.

In the context of recent changes in the Brazilian drug supply system at the national level, mainly the deactivation of CEME (a government agency under the Ministry of Health that dealt with drug supply policy) and the increasing decentralization of activities under the Unified National Health System (SUS), three Brazilian States - Paraná, São Paulo, and Minas Gerais - have established programs for the distribution of essential drugs for primary health care. A nationwide program for the procurement and supply of 32 drugs for primary health care (the so-called "Basic Pharmacy Program") is currently being implemented by the Ministry of Health, to be decentralized subsequently. This article discusses the establishment of State-level drug policies for primary health care through the analysis of the three pioneering programs encompassing drug selection, procurement, storage, distribution, and use.