The purpose of this paper is to provide an overview of the published research about chitosan, which is the deacetylated form of chitin, a natural biodegradable compound derived from crustaceous shells whose major attributes corresponds to its polycationic nature. This review points out its chemical and structural characteristics, obtainment methods, antimicrobial activity and its action mode. The potential of chitosan to induce a series of defence reactions correlated with certain enzymatic activities carried out by PAL, β-1,3-glucanase, chitinase and chitosanase is also reviewed.

El propósito de este artículo es proporcionar una revisión de la investigación publicada acerca de la quitosana que es la forma desacetilada de la quitina, un compuesto natural biodegradable que se deriva de cubiertas de crustáceos siendo su principal atributo su naturaleza policatiónica. Se revisan las características químicas y estructurales, métodos de obtención, actividad antimicrobiana y modo de acción. Asimismo, se analiza el potencial de la quitosana para inducir una serie de reacciones de defensa correlacionadas con la actividad enzimática tales como la PAL, β-1,3 glucanasa, quitinasa y quitosanasa.

Avaliou-se a infecção experimental por Salmonella Enteritidis fagotipo 4 (SEpt4) em embriões de frango de corte para averiguar a habilidade de penetração através da casca e o efeito da inoculação no albúmen, considerando-se a mortalidade, a eclodibilidade e a colonização intestinal dos pintos eclodidos. Foram realizados dois experimentos, distribuídos em quatro tratamentos (T) cada, com 200 e 194 ovos incubáveis das linhagens Ross e ISA Label, respectivamente. Utilizaram-se ovos não sanitizados e inoculados na casca com Salmonella Enteritidis (T1) ou com placebo (T2); ou inoculados no albúmen com Salmonella Enteritidis (T3) ou com placebo (T4). Imediatamente após a inoculação, os ovos foram incubados, e a mortalidade embrionária avaliada após 96, 432 e 528 horas. Salmonella Enteritidis inoculada na casca manteve-se viável na casca e nas membranas durante todo o período de incubação e migrou para o interior dos ovos, entretanto não afetou os parâmetros de incubação. O patógeno inoculado no albúmen determinou mortalidade embrionária tardia nas linhagens Ross, 17,0%, e ISA Label, 13,0%, e originou pintos com maior freqüência de colonização intestinal por Salmonella Enteritidis, 76,7% e 26,7% para Ross e ISA Label, respectivamente.

The experimental infection of Salmonella Enteritidis phagotype 4 (SEpt4) was evaluated in broilers embryos to verify the ability of penetration through eggshell and the effect of albumen inoculation considering embryo mortality, hatchability, and intestinal colonization of hatched chicks. Two trials were conducted using in four treatments each, totaling 200 and 194 fertile eggs of Ross and ISA Label lineages, respectively. Non-sanitized eggs were inoculated on the shell with Salmonella Enteritidis (Treatment 1) or placebo (Treatment 2); and eggs were inoculated in albumen with Salmonella Enteritidis (Treatment 3) or placebo (Treatment 4). Immediately after inoculation, the eggs were incubated and embryo mortality was evaluated after 96, 432, and 528 hours. The results showed that Salmonella Enteritidis inoculated on egg shell remained active there and in shell membranes during all incubation period and migrated to the interior of the eggs; however, it did not affect the incubation parameters. It was observed that Salmonella Enteritidis inoculated in albumen caused late embryo mortality in Ross (17.0%) and ISA Label (13.0%) lineages, and originated chicks with high frequency of intestinal colonization by Salmonella Enteritidis, being 76.7% and 26.7% for Ross and ISA Label, respectively.

Hepatitis C virus (HCV) infection is a serious public health problem, since 80% to 85% of HCV carriers develop a persistent infection that can progress into liver cirrhosis and hepatocarcinoma. Considering that the response of hepatitis C patients to combination therapy with interferon and ribavirin depends on HCV characteristics as well as on host features, we made a retrospective analysis of demographic and anthropometrical data and HCV genotype distribution of chronic hepatitis C patients treated in public and private reference centers in Brazil. The medical records of 4,996 patients were reviewed, 81% from public and 19% from private institutions. Patients' median age was 46 years, and there was a higher prevalence of male (62%) and white patients (80%). The analysis of HCV-infecting strains showed a predominance of genotype 1 (64%) over genotypes 2 and 3. The patients' mean weight was 70.6 kg, and 65% of the patients weighed less than 77kg. Overweight and obesity were observed in 37.8% and 13.6% of the patients, respectively. Since a body weight of 75 kg or less has been considered an independent factor that significantly increases the odds of achieving a sustained virological response, the Brazilian population seems to have a more favorable body weight profile to achieve a sustained response than the American and European populations. The finding that 65% of chronic hepatitis C patients have a body weight of 77 kg or less may have a positive pharmacoeconomic impact on the treatment of genotype 1 HCV patients with weight-based doses of peginterferon.

A recuperação das proteínas de pescado, de espécies de baixo valor comercial ou de subprodutos de sua industrialização, constitui-se em ma alternativa promissora para a elaboração de produtos alimentícios de alta qualidade nutricional e economicamente viáveis. O objetivo deste trabalho foi obter uma Base-Protéica-de-Pescado (BPP) que permitisse elaborar hambúrgueres com diferentes sabores. Pela disponibilidade e baixo custo de matéria-prima foi utilizada a pescada (Cynoscion striatus). A parte comestível, essencialmente músculo, foi submetida a sucessivas lavagens para retirar matéria solúvel e odores característicos, controlando-se as variáveis: solvente, soluto/solvente, tempo, temperatura, regime de agitação e número de ciclos de lavagens. A matéria-prima e BPP foram caracterizadas pelas propriedades físico-químicas e microbiológicas. O tratamento estatístico dos resultados, mediante modelo fatorial, permitiu verificar que é possível obter uma BPP, principalmente sem o sabor e odor característico do pescado, utilizando uma parte de soluto para cada duas de solvente, independente do tempo do ciclo de lavagens. A BPP foi utilizada para elaborar seis diferentes tipos de hambúrgueres e, mediante avaliação sensorial, utilizando escala hedônica para sabor, ficou evidenciada a aceitação de todos esses produtos não havendo preferência por um específico. Os resultados experimentais levam a concluir que a BPP, obtida a partir da pescada, pode ser utilizada na elaboração de hambúrgueres com bons atributos sensoriais e nutricionais.

The utilization of fish protein, from species of low commercial value or subproducts of industrialization, became a promising alternative for the food products development with high nutritive quality and economically feasible. The goal of this work was to obtain a Fish Protein Base (FPB) wich allowed preparation of different flavors of hamburgers. Whting Cynoscion striatu was used, due to the availability and low cost of raw material. The eatable part, essentially muscle, was submitted to successive washes to remove dissolvable matter and peculiar smell, maintaining under control the following variables: solvente, solute/solvent, time, temperature, agitating pattern and number of washing cycles. The raw material and FPB were characterized by their physical-chemical and microbiological properties. The statistic treatment, through factorial analysis, verified the conclusion that is possible to obtain an FPB, without the flavor or the peculiar smelling of fish, handling one part of solute for every two parts of solvent, independent on time and washing cycles. The FPB was utilized to elaborate six different types of hamburgers. By sensory evaluation, using hedonic scales for flavor, the acceptance of all these products was observed, without specific preference for one or another. The experimental results lead to the conclusion that whiting FPB, can be used to elaborate hamburgers with good sensorial and nutrition atributes.