Ultrastructural analysis of the effect of mating delay on cell death in the ovaries of virgin honey bee (Apis mellifera L.) queens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sudden change in quantum and classical correlations and the Unruh effect

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sudden changes in chaotic attractors and transient basins in a model for rattling in gearboxes

We consider a model for rattling in single-stage gearbox systems with some backlash consisting of two wheels with a sinusoidal driving; the equations of motions are analytically integrated between two impacts of the gear teeth. Just after each impact, a mapping is used to obtain the dynamical variables. We have observed a rich dynamical behavior in such system, by varying its control parameters, and we focus on intermittent switching between laminar oscillations and chaotic bursting, as well as crises, which are sudden changes in the chaotic behavior. The corresponding transient basins in phase space are found to be riddled-like, with a highly interwoven fractal structure. (C) 2004 Elsevier Ltd. All rights reserved.

Miocardite chagásica em caninos no Estado do Rio Grande do Sul

Neste trabalho, são relatados dois casos de morte súbita por doença de Chagas aguda em caninos da zona rural de Porto Alegre, Rio Grande do Sul, Brasil. Os cães, um macho Pit Bull com nove meses (canino 1) e uma fêmea Labrador Retriever com dois anos (canino 2), morreram em janeiro de 2005 e maio de 2008, respectivamente. As necropsias revelaram aumento cardíaco em ambos os casos. O coração do canino 2 apresentou formato globoso com múltiplas áreas pálidas na musculatura cardíaca, mais evidentes no ventrículo direito e câmaras cardíacas dilatadas, principalmente as da direita. Ao exame histológico, ambos os casos apresentaram alterações semelhantes caracterizadas por infiltrado inflamatório difuso não-purulento acentuado, predominantemente linfocitário intersticial. Nas fibras miocárdicas, havia grande número de pseudocistos, repletos de formas amastigotas do Trypanosoma cruzi. Ao teste sorológico TESA-blot, amostra do canino 2 foi positiva para anticorpos IgM e IgG anti-T.cruzi, achado característico da fase aguda da miocardite chagásica. Os resultados indicam que a doença de Chagas deve ser investigada em casos de morte súbita em cães na região Sul do Brasil e que a espécie pode servir como reservatório e sentinela da doença em humanos.

Cell death in ovarioles causes permanent sterility in Frieseomelitta varia worker bees

Frieseomelitta varia worker bees do not lay eggs even when living in queenless colonies, a condition that favors ovary development and oviposition in the majority of highly social bees. The permanent sterility of these worker bees was initially attributed to a failure in ovary morphogenesis and differentiation. Using transmission electron microscopy we found that at the beginning of the pupal phase the ovaries of F. varia workers are formed by four ovarioles, each of them composed of 1) a terminal filament at the apex of the ovarioles, containing juxtaposed and irregularly shaped cells, 2) a germarium with clusters of cystocytes and prefollicular cells showing long cytoplasmic projections that envelop the cystocyte clusters, 3) fusiform interfollicular and basal stalk precursor cells, and 4) globular, irregularly contoured basal cells with large nuclei. However, during the pupal phase an accentuated and progressive process of cell death takes place in the ovarioles. The dying cells are characterized by large membrane bodies, electron-dense apoptotic bodies, vacuoles, vesiculation, secondary lysosomes, enlarged rough endoplasmic reticulum cisternae, swollen mitochondria, pycnotic nuclei, masses of chromatin adjacent to the convoluted nuclear envelope, and nucleoli showing signs of fragmentation. Cell death continues in ovarioles even after the emergence of the workers. Once they become nurse bees, the ovaries have become transformed into a cell mass in which structurally organized ovarioles can no longer be identified. In F. varia workers, ovariole cell death most certainly is part of the program of caste differentiation.

Programmed cell death in salivary glands of Drosophila arizonae and Drosophila mulleri

Programmed cell death (PCD) in insect metamorphosis assumes a great diversity of morphology and controlling processes that are still not well understood. With the objective of obtaining information about the PCD process, salivary glands of Drosophila arizonae and D. mulleri were studied during larval-pupal development. From the results, it can be concluded that the type of the PCD that occurs in these organs is morphologically typical of apoptosis (formation of apoptotic nuclei, followed by fragmentation into apoptotic bodies). Histolysis happens in both species, between 22 and 23 h after pupation. There were no significant differences between the species studied. Apoptosis does not occur simultaneously in all cells. Cytoplasmic acid phosphatase activity gradually increases during development, suggesting the existence of acid phosphatases that are only expressed during the apoptotic stage. Twenty hours after pupation, salivary glands already show biochemical alterations relative to nuclear permeability such as acidification, possibly due to the fusion of lysosomes with the nucleus a few hours before apoptosis. Autophagy seems to act together with apoptosis and has a secondary role in cell death. ©FUNPEC-RP.

The Occurrence of Autophagic Cell Death in the Tegument of Rabbits Pre-Infested with Rhipicephalus sanguineus and Exposed to Selamectin (Active Principle of Acaricide Pfizer Revolution (R))

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Risk factors for perinatal death in two different levels of care: a case-control study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Molecular identification of food sources in triatomines in the Brazilian northeast: roles of goats and rodents in Chagas disease epidemiology

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tumour necrosis factor-alpha-induced protein 8 (TNFAIP8) expression associated with cell survival and death in cancer cell lines infected with canine distemper virus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sudden cardiac death athletes: a systematic review

Previous events evidence that sudden cardiac death (SCD) in athletes is still a reality and it keeps challenging cardiologists. Considering the importance of SCD in athletes and the requisite for an update of this matter, we endeavored to describe SCD in athletes. The Medline (via PubMed) and SciELO databases were searched using the subject keywords sudden death, athletes and mortality. The incidence of SCD is expected at one case for each 200,000 young athletes per year. Overall it is resulted of complex dealings of factors such as arrhythmogenic substrate, regulator and triggers factors. In great part of deaths caused by heart disease in athletes younger than 35 years old investigations evidence cardiac congenital abnormalities. Athletes above 35 years old possibly die due to impairments of coronary heart disease, frequently caused by atherosclerosis. Myocardial ischemia and myocardial infarction are responsible for the most cases of SCD above this age (80%). Pre-participatory athletes' evaluation helps to recognize situations that may put the athlete's life in risk including cardiovascular diseases. In summary, cardiologic examinations of athletes' pre-competition routine is an important way to minimize the risk of SCD. © 2010 Ferreira et al; licensee BioMed Central Ltd.

A novel association between Rhodnius neglectus and the Livistona australis palm tree in an urban center foreshadowing the risk of Chagas disease transmission by vectorial invasions in Monte Alto City, Sao Paulo, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Causes of death of thoroughbred racehorses at Octavio Dupont Veterinary Hospital, Brazilian Jockey Club, Rio de Janeiro

Existem poucas pesquisas que abordam estudos epidemiológicos de mortes em cavalos de corrida de uma forma ampla. A maioria restringe-se a uma afecção ou procedimento específico. O Brasil não possui um programa de monitoramento de mortes instituído. Através de um estudo descritivo em associação a metodologia multivariada de análise, realizou-se um estudo epidemiológico de causa mortis relacionadas com afecções musculosqueléticas (MS), gastrointestinais (GI), sistema respiratório (RES), neurológico (NEU) e mortes súbitas (SD) durante os anos de 2002 a 2008 no Hospital Octavio Dupont, Rio de Janeiro. Os machos representaram o sexo mais afetado e a causa mortis relacionada com a taxa geral de mortalidade por grandes grupos de causas determinadas apresentou a seguinte ordem decrescentemente: MS>GI>SD>NEU>RES. A maioria dos óbitos registrados foi de cavalos na faixa etária de quatro a cinco anos (ID4-ID5). Seguidamente, observaram-se as seguintes relações de correspondência: (Triênio = SM-ID>5-SD; ID>5-GI; ID4-5-MS; SF-ID<4-RES/NEU); (Quatriênio = SM - ID>5 - GI; SF - ID<4 - NEU; ID4-5 - MS; GI - ID>5). O presente estudo aponta a importância e necessidade de estudos epidemiológicos sobre lesões em cavalos atletas, objetivando o diagnostico, reconhecimento de fatores predisponentes e prevenção.

High-resolution electrocardiography in dogs under doxorubicin-induced cardiomyopathy

Determinaram-se a ocorrência de potencial tardio em cães com cardiomiopatia induzida pela doxorrubicina e sua relação com o desenvolvimento de arritmias ventriculares ou morte súbita. Sete cães adultos, sem raça definida, de ambos os sexos foram utilizados. A cardiomiopatia foi induzida por infusão venosa lenta de doxorrubicina (30mg/m²) em intervalos de 21 dias, até uma dose total cumulativa de 240mg/m². Os animais foram monitorados ecocardiograficamente. Após a confirmação da cardiomiopatia, foi feito o registro da eletrocardiografia de alta resolução. Potenciais tardios foram observados em dois animais que morreram subitamente poucos dias após.