Optimization of osmotic dehydration of papaya followed by air-drying

FERNANDES, Fabiano A. N. et al. Optimization of Osmotic Dehydration of Papaya of followed by air-drying. Food Research Internation, v. 39, p. 492-498, 2006.ABSTRACT: Papayas are a fragile fruit; characteristic that limits large-scale exportation from the producing centers to countries in temperate regions. Loss of fruit ranges from 10% to 40% and could be reduced if papayas were dried. The process of osmotic dehydration followed by air-drying was studied and modeled for papaya preservation, so it could be optimized. The developed model has been validated with experimental data and simulations have shown how the operating conditions affect the process. An optimization was done using the model in order to search for the best operation condition that would reduce the total processing time

Dual-stage sugar substitution in strawberries with a \u3ci\u3eStevia\u3c/i\u3e-based sweetener

The present study introduces and analyzes a new process denominated dual-stage sugar substitution (D3S). This process aims to induce sugar substitution in strawberries. In a first stage, high-calorie sugars (sucrose, fructose and glucose) are partially removed from the fruit samples and in a second stage, low-calorie sugar (stevioside and rebaudioside) is incorporated to the fruit to maintain its sweetness. The process was evaluated by studying the use of ultrasound application in one or both stages of the D3S process. Best performance of the process was obtained by subjecting the fruit samples to ultrasound in the sugar removal stage followed by immersion of the samples in Stevia-based solution without application of ultrasound in the sweetener incorporation stage. These operating conditions result in the highest sugar removal during the first stage, highest water loss during the process and highest sweetener incorporation during the second stage of the D3S process. The work described in this research is relevant to the production of dried fruits. A process to produce low-calorie dried fruit is presented. The process removes high-calorie sugars from the fruit and replaces it with a natural low-calorie sugar restoring the sweetness of the fruit

Coinfection with Trypanosoma brucei confers protection against cutaneous leishmaniasis

Infection with certain bacteria, parasites, and viruses alters the host immune system to Leishmania major influencing disease outcome. Here, we determined the outcome of a chronic infection with Trypanosoma brucei brucei on cutaneous leishmaniasis (CL) caused by L. major. C57BL/6 mice infected with T. b. brucei were given a sub-curative treatment with diminazene aceturate then coinfected with L. major by vector bites. Our results revealed that infection with T. b. brucei controls CL pathology. Compared to controls, coinfected mice showed a significant decrease in lesion size (P < 0.05) up to 6 weeks post-infection and a significant decrease in parasite burden (P < 0.0001) at 3 weeks post-infection. Protection against L. major resulted from a non-specific activation of T cells by trypanosomes. This induced a strong immune response characterized by IFN-gamma production at the site of bites and systemically, creating a hostile inflammatory environment for L. major parasites and conferring protection from CL

The Fate of Carbon in Sediments of the Xingu and Tapajós Clearwater Rivers, Eastern Amazon

The Xingu and Tapajós rivers in the eastern Amazon are the largest clearwater systems of the Amazon basin. Both rivers have “fluvial rias” (i.e., lake-like channels) in their downstream reaches as they are naturally impounded by the Amazon mainstem. Fluvial rias are widespread in the Amazon landscape and most of the sedimentary load from the major clearwater and blackwater rivers is deposited in these channels. So far, little is known about the role of Amazon rias as a trap and reactor for organic sediments. In this study, we used organic and inorganic geochemistry, magnetic susceptibility, diatom, and pollen analyses in sediments (suspended, riverbed, and downcore) of the Xingu and Tapajós rias to investigate the effects of hydrologic variations on the carbon budget in these clearwater rivers over the Holocene. Ages of sediment deposition (~100 to 5,500 years) were constrained by optically stimulated luminescence and radiocarbon. Major elements geochemistry and concentration of total organic carbon (TOC) indicate that seasonal hydrologic variations exert a strong influence on riverine productivity and on the input and preservation of organic matter in sediments. Stable carbon isotope data (δ13C from −31.04 to −27.49‰) and pollen analysis indicate that most of the carbon buried in rias is derived from forests. In the Xingu River, diatom analysis in bottom sediments revealed 65 infrageneric taxa that are mostly well-adapted to slack oligotrophic and acidic waters. TOC values in sediment cores are similar to values measured in riverbed sediments and indicate suitable conditions for organic matter preservation in sediments of the Xingu and Tapajós rias at least since the mid-Holocene, with carbon burial rates varying from about 84 g m−2 yr−1 to 169 g m−2 yr−1. However, redox-sensitive elements in sediment core indicate alternation between anoxic/dysoxic and oxic conditions in the water-sediment interface that may be linked to abrupt changes in precipitation. The variation between anoxic/dysoxic and oxic conditions in the water-sediment interface controls organic matter mineralization and methanogenesis. Thus, such changes promoted by hydrological variations significantly affect the capacity of Amazon rias to act either as sources or sinks of carbon

Doença de Marek visceral em pavão-branco (Pavo cristatus)

Doença de Marek (MD) é uma desordem linfoproliferativa causada pelo Gallid herpesvirus 2 (MDV), que infecta principalmente galináceos domésticos, porém aves silvestres podem ser ocasionalmente afetadas. O presente relato descreve os achados anatomopatológicos e moleculares de um caso de MD em um pavão-branco (Pavo cristatus). Os sinais clínicos incluíram apatia, hiporexia e diarreia. Macroscopicamente, foram observados nódulos macios, de 0,5 a 1,5cm de diâmetro, no músculo esquelético, no pulmão, nos rins, nos sacos aéreos, no intestino delgado, no coração, no ovário, no ventrículo e no proventrículo. Microscopicamente, numerosas células redondas neoplásicas atípicas foram notadas. A detecção molecular do DNA do MDV foi implementada para amplificar parte do gene meq, e os produtos foram sequenciados para análise filogenética. DNA foi obtido de tecidos de aves afetadas e do sangue de todos os galináceos do zoológico. A esperada amplificação de parte do gene meq de MDV amplificado foi ampliada e sequenciada. As sequências obtidas permitiram o agrupamento da cepa (acesso KT768121) com cepas do sorotipo 1 de MDV do GenBank.. O diagnóstico de MD em pavão-branco foi obtido com base nos achados anatomopatológicos e moleculares e, pelo conhecimento dos autores, não há relatos anteriores publicados de MD em Pavo cristatus.Marek's disease (MD) is a lymphoproliferative disorder caused by Gallid herpesvirus 2 (MDV) that infects mainly domestic gallinaceous birds although wild birds may occasionally be affected. The current report describes the anatomopathological and molecular findings of a case of MD in a white-peafowl (Pavo cristatus). The signs included apathy, hyporexia, and diarrhea. Grossly, 0.5 to 1.5cm in diameter, yellow, soft nodules were observed in the skeletal muscle, lung, kidney, air sacs, small intestine, heart, ovary, ventriculus, and proventriculus. Microscopically, numerous atypical round neoplastic cells were noted. The molecular detection of MDV DNA was implemented to amplify part of the meq gene and products were sequenced for the phylogenetic analysis. Template DNA was obtained from tissues of the affected bird and from blood of all the gallinaceous birds of the Zoo. The expected amplicon for the partial amplification of MDV meq gene was obtained and the amplicons were sequenced. Sequences obtained enabled grouping the strain (accession no. KT768121) with MDV serotype 1 strains from the GenBank. Based on the anatomopathological and molecular findings, the diagnosis of MD in a white-peafowl was reached, and to the authors' knowledge, no previous report regarding MD was published in Pavo cristatus

Discovery of Markers of Exposure Specific to Bites of Lutzomyia longipalpis, the Vector of Leishmania infantum chagasi in Latin America

Leishmania parasites are transmitted by the bite of an infected vector sand fly that injects salivary molecules into the host skin during feeding. Certain salivary molecules can produce antibodies and can be used as an indicator of exposure to a vector sand fly and potentially the disease it transmits. Here we identified potential markers of specific exposure to the sand fly Lutzomyia longipalpis, the vector of visceral leishmaniasis in Latin America. Initially, we determined which of the salivary proteins produce antibodies in humans, dogs, and foxes from areas endemic for the disease. To identify potential specific markers of vector exposure, we produced nine different recombinant salivary proteins from Lu. longipalpis and tested for their recognition by individuals exposed to another human-biting sand fly, Lu. intermedia, that transmits cutaneous leishmaniasis and commonly occurs in the same endemic areas as Lu. longipalpis. Two of the nine salivary proteins were recognized only by humans exposed to Lu. longipalpis, suggesting they are immunogenic proteins and may be useful in epidemiological studies. The identification of specific salivary proteins as potential markers of exposure to vector sand flies will increase our understanding of vector–human interaction, bring new insights to vector control, and in some instances act as an indicator for risk of acquiring disease

Factors associated with paradoxical immune response to antiretroviral therapy in HIV infected patients: a case control study

<p>Abstract</p> <p>Background</p> <p>A paradoxical immunologic response (PIR) to Highly Active Antiretroviral Therapy (HAART), defined as viral suppression without CD4 cell-count improvement, has been reported in the literature as 8 to 42%, around 15% in most instances. The present study aims to determine, in a cohort of HIV infected patients in Brazil, what factors were independently associated with such a discordant response to HAART.</p> <p>Methods</p> <p>A case-control study (1:4) matched by gender was conducted among 934 HIV infected patients on HAART in Brazil. Cases: patients with PIR, defined as CD4 < 350 cells/mm³(hazard ratio for AIDS or death of at least 8.5) and undetectable HIV viral load on HAART for at least one year. Controls: similar to cases, but with CD4 counts ≥ 350 cells/mm³. Eligibility criteria were applied. Data were collected from medical records using a standardized form. Variables were introduced in a hierarchical logistic regression model if a p-value < 0.1 was determined in a bivariate analysis.</p> <p>Results</p> <p>Among 934 patients, 39 cases and 160 controls were consecutively selected. Factors associated with PIR in the logistic regression model were: total time in use of HAART (OR 0.981; CI 95%: 0.96-0.99), nadir CD4-count (OR 0.985; CI 95%: 0.97-0.99), and time of undetectable HIV viral load (OR 0.969; CI 95%: 0.94-0.99).</p> <p>Conclusions</p> <p>PIR seems to be related to a delay in the management of immunodeficient patients, as shown by its negative association with nadir CD4-count. Strategies should be implemented to avoid such a delay and improve the adherence to HAART as a way to implement concordant responses.</p