Caracterização da diversidade de leveduras isoladas de uva merlot de parreirais de Santana do Livramento - RS.

Monografia (Bacharel em Biomedicina) - Faculdade Cenecista de bento Gonçalves, Faculdade de Biomedicina. Orientador: Dra. Crislaine Aparecida Paludo (FACEBG) e Co-orientação do Dr. Gildo Almeida da Silva (EMBRAPA

Doença de pequenas vias aereas em pacientes submetidos a transplante de medula ossea : experiencia de 7 casos e revisão da literatura

Orientador: Ricardo PasquiniDissertação (mestrado) - Universidade Federal do Parana, Setor de Ciencias da SaudeResumo: A partir da década de 70, o Transplante de Medula Óssea constituiu-se em opção de excelência para o tratamento de inúmeras enfermidades malignas e não malignas. Em decorrência do procedimento, inúmeras complicações podem aparecer. Entre estas, as pulmonares são comuns e interferem no sucesso do TMO. No período de outubro de 1979 a dezembro de 1992, 435 pacientes foram submetidos a transplante de medula óssea no Hospital de Clínicas da UFPR. Duzentos e noventa e quatro (67%) tiveram sobrevida maior do que 100 dias e 127 (29%) desenvolveram doença do enxerto contra o hospedeiro (DECH) na forma crônica. Sete pacientes do total (1,6%) apresentaram características clínicas e funcionais de doença das pequenas vias aéreas (DPVA) cuja descrição e confrontação com a bibliografia existente representam o objeto deste trabalho. Em 100% dos casos descritos ocorreu concomitantemente DECH crônica, confirmando a associação entre as duas entidades. Todos os pacientes apresentaram alterações funcionais respiratórias do tipo obstrutivo, diagnosticados como de grau severo. A significativa diferença entre os valores dos volumes pulmonares obtidos nas fases pré e pós-transplante, associada a características da evolução clínica forneceram o embasamento para o diagnóstico da DPVA. O intervalo entre a data do TMO e o desenvolvimento da DPVA mostrou-se maior quando comparado a outras séries reportadas na literatura. Todos os pacientes foram a óbito, por insuficiência respiratória, variando a sobrevida de 9 a 26 meses. A terapêutica com broncodilatadores esteróides não mostrou benefício significativo

The Raphe Pallidus and the Hypothalamic-Pituitary-Thyroid Axis Gate Seasonal Changes in Thermoregulation in the Hibernating Arctic Ground Squirrel (Urocitellus parryii)

Thermoregulation is necessary to maintain energy homeostasis. The novel discovery of brown adipose tissue (BAT) in humans has increased research interests in better understanding BAT thermogenesis to restore energy balance in metabolic disorders. The hibernating Arctic ground squirrel (AGS) offers a novel approach to investigate BAT thermogenesis. AGS seasonally increase their BAT mass to increase the ability to generate heat during interbout arousals. The mechanisms promoting the seasonal changes in BAT thermogenesis are not well understood. BAT thermogenesis is regulated by the raphe pallidus (rPA) and by thyroid hormones produced by the hypothalamic–pituitary–thyroid (HPT) axis. Here, we investigate if the HPT axis and the rPA undergo seasonal changes to modulate BAT thermogenesis in hibernation. We used histological analysis and tandem mass spectrometry to assess activation of the HPT axis and immunohistochemistry to measure neuronal activation. We found an increase in HPT axis activation in fall and in response to pharmacologically induced torpor when adenosine A1 receptor agonist was administered in winter. By contrast, the rPA neuronal activation was lower in winter in response to pharmacologically induced torpor. Activation of the rPA was also lower in winter compared to the other seasons. Our results suggest that thermogenic capacity develops during fall as the HPT axis is activated to reach maximum capacity in winter seen by increased free thyroid hormones in response to cooling. However, thermogenesis is inhibited during torpor as sympathetic premotor neuronal activation is lower in winter, until arousal when inhibition of thermogenesis is relieved. These findings describe seasonal modulation of thermoregulation that conserves energy through attenuated sympathetic drive, but retains heat generating capacity through activation of the HPT axis

Comparison between azithromycin and amoxicillin in the treatment of infectious exacerbation of chronic obstructive pulmonary disease

OBJECTIVE: To compare the efficacy, safety, and tolerability of azithromycin and amoxicillin in the treatment of patients with infectious exacerbation of chronic obstructive pulmonary disease. METHODS: This study was conducted at six medical centers across Brazil and included 109 patients from 33 to 82 years of age. Of those, 102 were randomized to receive either azithromycin (500 mg/day for three days, n = 49) or amoxicillin (500 mg every eight hours for ten days, n = 53). The patients were evaluated at the study outset, on day ten, and at one month. Based on the clinical evaluation of the signs and symptoms present on day ten and at one month, the outcomes were classified as cure, improvement, or treatment failure. The microbiological evaluation was made through the culture of sputum samples that were considered appropriate samples only after leukocyte counts and Gram staining. Secondary efficacy evaluations were made in order to analyze symptoms (cough, dyspnea, and expectoration) and pulmonary function. RESULTS: There were no differences between the groups treated with azithromycin or amoxicillin in terms of the percentages of cases in which the outcomes were classified as cure or improvement: 85% vs. 78% (p = 0.368) on day ten; and 83% vs. 78% (p = 0.571) at one month. Similarly, there were no significant differences between the two groups in the secondary efficacy variables or the incidence of adverse effects. CONCLUSION: Azithromycin and amoxicillin present similar efficacy and tolerability in the treatment of acute exacerbation of chronic obstructive pulmonary disease.OBJETIVO: Comparar a eficácia, segurança e tolerabilidade da azitromicina e da amoxicilina no tratamento de pacientes com quadro clínico de exacerbação infecciosa da doença pulmonar obstrutiva crônica. MÉTODOS: Seis centros brasileiros incluíram 109 pacientes com idades entre 33 e 82 anos. Desses pacientes, 102 foram randomizados para receber azitromicina (500 mg por dia por três dias, n = 49) ou amoxicilina (500 mg a cada oito horas por dez dias, n = 53). Os pacientes foram avaliados no início do estudo, após dez dias e depois de um mês. A avaliação clínica, de acordo com os sinais e sintomas presentes após dez dias e após um mês, consistiu na classificação dos casos nas categorias cura, melhora ou falha terapêutica. A avaliação microbiológica foi feita pela cultura de amostras de escarro consideradas adequadas após contagem de leucócitos e coloração de Gram. Avaliações secundárias de eficácia foram feitas com relação aos sintomas (tosse, dispnéia e expectoração) e à função pulmonar. RESULTADOS: Não houve diferenças entre as proporções de casos classificados como cura ou melhora entre os grupos tratados com a azitromicina ou a amoxicilina. Essas proporções foram, respectivamente, de 85% vs. 78% (p = 0,368) após dez dias, e de 83% vs. 78% (p = 0,571) após um mês. Também não foram encontradas diferenças significativas entre os dois grupos quando comparadas as variáveis secundárias de eficácia e a incidência de eventos adversos. CONCLUSÃO: A azitromicina tem eficácia e tolerabilidade semelhantes às da amoxicilina para o tratamento da exacerbação aguda da Doença pulmonar obstrutiva crônica.Universidade Federal do Rio Grande do SulUniversidade Federal de São Paulo (UNIFESP)Universidade Federal do Paraná Departmento de Clínica MédicaFaculdade de Medicina do ABCUniversidade Estadual de Londrina Centro de Ciências da Saúde Departmento de Clínica MédicaSanta Casa de Porto Alegre Pavilhão Pereira FilhoUNIFESPSciEL

Large Proteins Have a Great Tendency to Aggregate but a Low Propensity to Form Amyloid Fibrils

The assembly of soluble proteins into ordered fibrillar aggregates with cross-β structure is an essential event of many human diseases. The polypeptides undergoing aggregation are generally small in size. To explore if the small size is a primary determinant for the formation of amyloids under pathological conditions we have created two databases of proteins, forming amyloid-related and non-amyloid deposits in human diseases, respectively. The size distributions of the two protein populations are well separated, with the systems forming non-amyloid deposits appearing significantly larger. We have then investigated the propensity of the 486-residue hexokinase-B from Saccharomyces cerevisiae (YHKB) to form amyloid-like fibrils in vitro. This size is intermediate between the size distributions of amyloid and non-amyloid forming proteins. Aggregation was induced under conditions known to be most effective for amyloid formation by normally globular proteins: (i) low pH with salts, (ii) pH 5.5 with trifluoroethanol. In both situations YHKB aggregated very rapidly into species with significant β-sheet structure, as detected using circular dichroism and X-ray diffraction, but a weak Thioflavin T and Congo red binding. Moreover, atomic force microscopy indicated a morphology distinct from typical amyloid fibrils. Both types of aggregates were cytotoxic to human neuroblastoma cells, as indicated by the MTT assay. This analysis indicates that large proteins have a high tendency to form toxic aggregates, but low propensity to form regular amyloid in vivo and that such a behavior is intrinsically determined by the size of the protein, as suggested by the in vitro analysis of our sample protein

Spatial Extent of Charge Repulsion Regulates Assembly Pathways for Lysozyme Amyloid Fibrils

Formation of large protein fibrils with a characteristic cross β-sheet architecture is the key indicator for a wide variety of systemic and neurodegenerative amyloid diseases. Recent experiments have strongly implicated oligomeric intermediates, transiently formed during fibril assembly, as critical contributors to cellular toxicity in amyloid diseases. At the same time, amyloid fibril assembly can proceed along different assembly pathways that might or might not involve such oligomeric intermediates. Elucidating the mechanisms that determine whether fibril formation proceeds along non-oligomeric or oligomeric pathways, therefore, is important not just for understanding amyloid fibril assembly at the molecular level but also for developing new targets for intervening with fibril formation. We have investigated fibril formation by hen egg white lysozyme, an enzyme for which human variants underlie non-neuropathic amyloidosis. Using a combination of static and dynamic light scattering, atomic force microscopy and circular dichroism, we find that amyloidogenic lysozyme monomers switch between three different assembly pathways: from monomeric to oligomeric fibril assembly and, eventually, disordered precipitation as the ionic strength of the solution increases. Fibril assembly only occurred under conditions of net repulsion among the amyloidogenic monomers while net attraction caused precipitation. The transition from monomeric to oligomeric fibril assembly, in turn, occurred as salt-mediated charge screening reduced repulsion among individual charged residues on the same monomer. We suggest a model of amyloid fibril formation in which repulsive charge interactions are a prerequisite for ordered fibril assembly. Furthermore, the spatial extent of non-specific charge screening selects between monomeric and oligomeric assembly pathways by affecting which subset of denatured states can form suitable intermolecular bonds and by altering the energetic and entropic requirements for the initial intermediates emerging along the monomeric vs. oligomeric assembly path

Clones Identification and Genetic Characterization of Garnacha Grapevine by Means of Different PCR-Derived Marker Systems

This study uses PCR-derived marker systems to investigate the extent and distribution of genetic variability of 53 Garnacha accessions coming from Italy, France and Spain. The samples studied include 28 Italian accessions (named Tocai rosso in Vicenza area; Alicante in Sicily and Elba island; Gamay perugino in Perugia province; Cannonau in Sardinia), 19 Spanish accessions of different types (named Garnacha tinta, Garnacha blanca, Garnacha peluda, Garnacha roja, Garnacha erguida, Garnacha roya) and 6 French accessions (named Grenache and Grenache noir). In order to verify the varietal identity of the samples, analyses based on 14 simple sequence repeat (SSR) loci were performed. The presence of an additional allele at ISV3 locus (151 bp) was found in four Tocai rosso accessions and in a Sardinian Cannonau clone, that are, incidentally, chimeras. In addition to microsatellite analysis, intravarietal variability study was performed using AFLP, SAMPL and M-AFLP molecular markers. AFLPs could discriminate among several Garnacha samples; SAMPLs allowed distinguishing few genotypes on the basis of their geographic origin, whereas M-AFLPs revealed plant-specific markers, differentiating all accessions. Italian samples showed the greatest variability among themselves, especially on the basis of their different provenance, while Spanish samples were the most similar, in spite of their morphological diversity

Local Cooperativity in an Amyloidogenic State of Human Lysozyme Observed at Atomic Resolution

The partial unfolding of human lysozyme underlies its conversion from the soluble state into amyloid fibrils observed in a fatal hereditary form of systemic amyloidosis. To understand the molecular origins of the disease, it is critical to characterize the structural and physicochemical properties of the amyloidogenic states of the protein. Here we provide a high-resolution view of the unfolding process at low pH for three different lysozyme variants, the wild-type protein and the mutants I56T and I59T, which show variable stabilities and propensities to aggregate in vitro. Using a range of biophysical techniques that includes differential scanning calorimetry and nuclear magnetic resonance spectroscopy, we demonstrate that thermal unfolding under amyloidogenic solution conditions involves a cooperative loss of native tertiary structure, followed by progressive unfolding of a compact, molten globule-like denatured state ensemble as the temperature is increased. The width of the temperature window over which the denatured ensemble progressively unfolds correlates with the relative amyloidogenicity and stability of these variants, and the region of lysozyme that unfolds first maps to that which forms the core of the amyloid fibrils formed under similar conditions. Together, these results present a coherent picture at atomic resolution of the initial events underlying amyloid formation by a globular protein

Amyloidogenic Regions and Interaction Surfaces Overlap in Globular Proteins Related to Conformational Diseases

Protein aggregation underlies a wide range of human disorders. The polypeptides involved in these pathologies might be intrinsically unstructured or display a defined 3D-structure. Little is known about how globular proteins aggregate into toxic assemblies under physiological conditions, where they display an initially folded conformation. Protein aggregation is, however, always initiated by the establishment of anomalous protein-protein interactions. Therefore, in the present work, we have explored the extent to which protein interaction surfaces and aggregation-prone regions overlap in globular proteins associated with conformational diseases. Computational analysis of the native complexes formed by these proteins shows that aggregation-prone regions do frequently overlap with protein interfaces. The spatial coincidence of interaction sites and aggregating regions suggests that the formation of functional complexes and the aggregation of their individual subunits might compete in the cell. Accordingly, single mutations affecting complex interface or stability usually result in the formation of toxic aggregates. It is suggested that the stabilization of existing interfaces in multimeric proteins or the formation of new complexes in monomeric polypeptides might become effective strategies to prevent disease-linked aggregation of globular proteins