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The objective of the work was to know the reference values of thyroxin (T4) hormone under grazing condition of beef cattle in the northwest area of La Pampa. Hundred eighteen blood samples from bovine allocated in six beef farms at the Department of Realico, Chapaleufú, Maracó and Quemú-Quemú were evaluated as consequence of different feeding type. The values founded in blood T4 concentration varied in relation to the amount of iodine concentration in the feedstuff, being the lowest values at the Rancul department. [ABSTRACT FROM AUTHOR]

Abstract: Efforts for the development of new therapeutics, essential for the control of leishmaniasis rely mainly on screening of potentially effective compounds in pathogen growth/multiplication assays, both in vitro and in vivo. Screenings designed to closely reflect the situation in vivo are currently labor-intensive and expensive, since they require intracellular amastigotes and animal models. Screenings designed to facilitate rapid testing of a large number of drugs are not performed on the clinically relevant parasite stage, but the promastigotes. The ability to select transgenic Leishmania expressing reporter proteins, such as the green fluorescent protein (GFP) or the luciferase, opened up new possibilities for the development of drug screening tests. In this review we will focus on available methodologies for direct drug screening purposes against the mammalian stage of the parasite, with emphasis on the future developments that could improve sensitivity, reliability, versatility and the throughput of the intracellular model screening. [Copyright &y& Elsevier]

This approach is based on the following theoretical and methodological assumptions: the classroom should be an environment for exchange between experiential and academic culture. The firstone will be point of departure where the new contents activate habitual schemas of acting and thinking. Thus we can sate that the acquisition of the academic culture should take place trough a process of reconstruction rather than imposition. Furthermore, its important to generate an atmosphere of meaningful learning to foster a reflective and critical attitude on the part of student, who should be able to establish a relationship between pre-existing cognitive structures and the knowledge. This approach will result in a total comprehension of the new theoretical and practical propositions. This approach will be developed in the Medical Pathology Course of the Internal Medicine Department. This is an annual course dictated to sixty students in the fourth year of Veterinary Medicine. The activities are based on a problem situation, where bibliographic resources will be required. The topic "Downer Cow Syndrome" is broad, considering that it can be caused by different pathologies. For this reason, it is important to intercalate practice and theory, where the student should use the knowledge he has acquired in other subjects to find out the pathologic agent that caused the animals decubitus. [ABSTRACT FROM AUTHOR]

During the last 20 years, Leishmania (Mundinia) spp. have emerged as new causative agents of human and animal leishmaniases. We provide a historical view of these parasites, from their initial description to their emergence as pathogens, to help avoiding future confusion in species assignation of these newly emerging pathogens. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the susceptibility to anti-leishmanial agents of 24 strains isolated from dogs living in the urban area of Alger lacking drug selection pressure. Two different Leishmania infantum zymodemes, MON-1 and MON-281, were identified in these dogs. The in vitro susceptibility to the main forms of antimonial and amphotericin were assessed on promastigote and amastigote life stages in culture. The results obtained for both parasite life stages were concordant whatever the molecule tested. Moreover, our data showed that isolates belonging to the relatively rare zymodeme of L. infantum, MON-281, were less susceptible to antimony than MON-1, when at the same time there was no significant difference for amphotericin B. [Copyright &y& Elsevier]

Summary NAD+ is a central cofactor that plays important roles in cellular metabolism and energy production in all living cells. Genomics-based reconstruction of NAD+ metabolism revealed that Leishmania protozoan parasites are NAD+ auxotrophs. Consequently, these parasites require assimilating NAD+ precursors (nicotinamide, nicotinic acid, nicotinamide riboside) from their host environment to synthesize NAD+ by a salvage pathway. Nicotinamidase is a key enzyme of this salvage pathway that catalyses conversion of nicotinamide (NAm) to nicotinic acid (Na), and that is absent in higher eukaryotes. We present here the biochemical and functional characterizations of the Leishmania infantum nicotinamidase (LiPNC1). Generation of Lipnc1 null mutants leads to a decrease in NAD+ content, associated with a metabolic shutdown-like phenotype with an extensive lag phase of growth. Both phenotypes could be rescued by an add-back construct or by addition of exogenous Na. In addition, Lipnc1 null mutants were unable to establish a sustained infection in a murine experimental model. Altogether, these results illustrate that NAD+ homeostasis is a fundamental component of Leishmania biology and virulence, and that NAm constitutes its main NAD+ source in the mammalian host. The crystal structure of LiPNC1 we solved allows now the design of rational inhibitors against this new promising therapeutic target. [ABSTRACT FROM AUTHOR]

The honey is defined as the natural sweet substance produced by Apis mellifera bees from the nectar or secretions of plants; or excretions of sucking insects that lives on them. The bees collect, transform and combine with specific substances of their own in the honey comb. The objective of this work was to characterize the honey of the province of La Pampa, based on physico-chemical and microbiological features to search for indicators to ensure better quality for internal and external trade of this product. Thirty-eight samples of different honey-farm, dividing the province of La Pampa in 4 different zones (North, South, East and West) were analyzed. The physico-chemical determinations were pH; total acidity, free acidity and lactone; diastase and ashes. The microbiological analysis made was: determination of total aerobic bacteria count, determination of total coliforms, determination of Salmonella sp and Shigella and the determination of fungi and yeasts. According to the regulations of the CAA results were observed in all cases and regulation MERCOSUR thus also to international standards, concluding honeys in the province of La Pampa can be considered as a good Argentine quality product. [ABSTRACT FROM AUTHOR]

Dogs are the domestic reservoir of zoonotic visceral Leishmaniasis caused by Leishmania infantum in the Mediterranean basin and thus constitute an important health problem in both human and veterinary medicine. Until vaccines become available, conventional measures such as epidemiological surveillance including reservoir control will be among the practical options for prevention and containment of the disease. We have recently characterised novel Leishmania sp. genes encoding parasite proteins named (LmS3a: homologous to mammalian ribosomal protein S3a; LmSIR2: homologous to the silent information regulatory 2 protein family; LimTXNPx: homologous to the peroxiredoxin family with N-terminal mitochondrial leader sequence) that may contribute to the host immune dysfunction in murine experimental Leishmaniasis. In the present study we have investigated the humoral responses against the parasite antigens in groups of L. infantum-infected dogs with different clinical status: symptomatic and asymptomatic with DTH positive or negative test. The determination of immunoglobulin (Ig) isotypes revealed high levels of total IgG in both symptomatic and asymptomatic animals when compared to IgM. Furthermore, the IgG2 appeared to be the predominant subclass of Ig present in the sera of infected animals particularly in the case of symptomatic dogs. The IgG subclass reactivity analysis revealed a broad specific recognition range of parasite recombinant antigens. Interestingly, differential profiles of IgG1 and IgG2 antibody reactivity were observed in asymptomatic and symptomatic dogs. The LmSIR2 protein was found to be a highly reactive molecule with IgG2 from most of the asymptomatic and symptomatic animals. Considering the fact that LmSIR2 secreted by the parasites can be bound and taken up by neighbouring cells, the latter could be a target for anti-LmSIR2 antibodies and this may contribute to the immunopathological alterations and host tissue damage. The implications of these observations in the pathogenesis of Leishmaniasis are discussed. [Copyright &y& Elsevier]