Alterações da densidade mineral óssea em vértebras de ratos Wistar submetidos à ausência de carga nos membros pélvicos

The suspension of rats by the tail model is used to investigate the behavior of bone in animals unable to move around. Bone is an adaptative tissue that develops in structure and function, among other factors, in response to mechanical forces applied to it and metabolic demands that it will suffer. The absence of mechanical forces and deformation of bone that occurs causes a decrease in calcium deposition in the absence of stimuli on osteoblasts and osteocytes, favoring the action of osteoclasts, making bones weak and brittle. Therefore, the mechanical action is necessary to stimulate local bone response and thus provide growth and remodeling. The aim of this study was to evaluable by radiographic densitometry, the tail suspension for 15 and 36 days alter the bone mineral density of cervical vertebrae (C3), thoracic (T6) and lumbar (L1 and L3) of Wistar rats. Thirty Rattus norvegicus albinus, adult, male, Wistar strain, average body mass ± 350g, were divided into 3 groups: control (n = 10) - not suspended; S15 (n = 10) - suspended for 15 days and S36 (n = 10) - suspended for 36 days. For densitometric analysis vertebrae were radiographed, scanned, digitized and analyzed by the computer program ImageJ®. There was a statistically significant increase in bone mineral density in group S15, probably by the restlessness of the animals to the suspension, with a decrease in group S36, and this hypothetically is linked to the accommodation of the rats, concluding that the tail suspension altered bone mineral density in first time with a decrease over time.  A suspensão de ratos pela cauda é modelo utilizado para investigar o comportamento ósseo em animais impossibilitados de se locomoverem. O osso é um tecido adaptativo que se desenvolve em sua estrutura e função, entre outros fatores, em resposta a forças mecânicas aplicadas a ele e demandas metabólicas que venha sofrer. A ausência de forças mecânicas e de deformação óssea faz com que ocorra uma diminuição na deposição de cálcio por ausência de estímulos nos osteoblastos e osteócitos, favorecendo a ação dos osteoclastos, tornando o osso enfraquecido e quebradiço. Portanto, a ação mecânica é necessária para estimular a resposta óssea local e, assim, proporcionar seu crescimento e remodelamento. O objetivo deste estudo foi avaliar, através da densitometria radiográfica, se a suspensão pela cauda por 15 e 36 dias altera a densidade mineral óssea das vértebras cervical (C3), torácica (T6) e lombares (L1 e L3) de ratos Wistar. Trinta Rattus norvegicus albinus, adultos, machos, linhagem Wistar, massa corpórea média de ± 350g, foram divididos em 3 grupos: controle (n=10) – não suspenso; S15 (n=10) - suspenso por 15 dias e S36 (n=10) - suspenso por 36 dias. Para análise densitométrica, as vértebras foram radiografadas, escaneadas, digitalizadas e analisadas pelo programa computacional ImageJ®. Houve aumento estatisticamente significante da densidade mineral óssea no grupo S15, provavelmente pela inquietação dos animais à suspensão, com diminuição no grupo S36, fato este hipoteticamente ligado à acomodação dos mesmos, concluindo que a suspensão pela cauda alterou a densidade mineral óssea num primeiro momento com diminuição com o passar do tempo

Are Aedes aegypti mosquitoes potential vectors for leishmaniasis? – Case report

No Brasil, os dípteros do gênero Lutzomyia são os principais vetores da leishmaniose para humanos e animais. No entanto, tem sido constatado que outras espécies de invertebrados hematófagos, como carrapatos, pulgas e mutucas, também podem ser vetores desse protozoário. Este trabalho, realizado em uma área endêmica de leishmaniose visceral, é a primeira descrição da presença de Leishmania spp. em mosquitos da espécie A. aegypti. Dois mosquitos A. aegypti foram capturados no local onde estava isolado um cão polissintomático acometido por leishmaniose visceral, confirmada pela demonstração do parasita em biópsias de órgãos e por resultado positivo na prova de PCR para Leishmania spp. Um dos mosquitos estava sugando o sangue do cão e o outro estava livre no ambiente. O mosquito ingurgitado com o sangue do animal foi esmagado entre duas lâminas de microscopia e o outro foi processado por meio da reação em cadeia pela polimerase (PCR) aplicada à pesquisa do ADN de Leishmania spp. Ao exame microscópico do esfregaço preparado com o mosquito que estava parasitando o cão foram observadas formas amastigotas de Leishmania spp., bem como formas flageladas de outra espécie de protozoário. No outro inseto foi detectada amplificação de ADN do gênero Leishmania. Esta constatação reforça o papel dos cães como fontes de infecção de Leishmania spp. até mesmo para outras espécies de vetores potenciais.In Brazil dipters of the Lutzomyia genus are the main vectors of leishmaniasis for humans and animals. However, other hematophagous insects such as ticks, fleas, and horse flies may also be considered potential vectors of this protozoon. This paper, regarding an endemic area for visceral leishmaniasis, is the the first description of the Leishmania spp. presence in Aedes aegypti mosquitoes. Two A. aegypti mosquitoes were captured: one of them was feeding on a polysymptomatic dog with leishmaniasis, confirmed by parasitic demonstration and positive PCR for Leishmania spp., and the other was collected in the environment where the dog was isolated. The mosquito engorged with dog’s blood was crushed between two microscopic slides and the other one was processed by the polymerase chain reaction assay (PCR) searching for the presence of Leishmania spp. DNA. Amastigote forms of Leishmania sp, were observed in the smear prepared from one mosquito by microscopic examination, as well as other protozoa’s flagellated forms. In the other insect it was observed Leishmania DNA amplification. This observation reinforces the role of dogs as sources of infection of Leishmania spp. even to other potential vector species

Efeito do ultra-som de baixa potência na reparação óssea em ratos sob ausência de carga: análise densitométrica e biomecânica

A literatura apresenta que a resposta de reparo ósseo pode ser acentuada pela estimulação física, mecânica ou eletromagnética. Há evidências de que o ultra-som – US – de baixa potência pode acelerar a regeneração óssea. Este trabalho objetivou verificar o efeito do US no defeito ósseo, criado experimentalmente, em tíbias de ratos sob ausência de carga (suspenso pela cauda) por meio de análise densitométrica e biomecânica. Trinta Rattus novergicus albinus, Wistar, adultos, divididos em 3 grupos: G1 (n=10), não suspenso - experimento de 15 dias; G2 (n=10), suspenso pela cauda - experimento de 15 dias e, G3 (n=10), suspensos pela cauda, experimento de 36 dias. Os animais foram submetidos à osteotomia em ambas as tíbias e à aplicação do US (freqüência de 1,5 MHz, ciclo 1:4, 30mW/cm2) na direita (12 sessões de 20 minutos). O G3 somente foi osteotomizado após 21º dia de suspensão. Para análises densitométrica utilizou-se densitômetro DPXLunar ™, sistema digital Digora e o programa computacional Image J ; para ensaio mecânico usou máquina universal de ensaio EMIC . Os resultados do Conteúdo Mineral Ósseo (g), Área (cm²), Densidade Mineral Óssea (g/cm²) e da Densidade Óssea (mmAl) observadas nas tíbias, assim como a Força Máxima (N) e Rigidez (x103N/m) não demonstraram diferenças significantes (tratadas versus controle de cada grupo), possivelmente pelo menor tempo de tratamento com relação aos trabalhos encontrados na literatura. Concluindo que o Ultra-Som de baixa potência não acelerou o processo de consolidação óssea.Literature shows that bone repair response can be accented by physical, mechanic or electromagnetic stimulation. There are evidences that low power ultrasound – US - can speed up bone regeneration. This work aimed at determining the effect of US in bone defects, experimentally created, in tibia from rats under load absence (suspended by the tail) by densitometric analysis and biomechanics. Thirty Rattus novergicus albinus, Wistar, adult, divided in 3 groups: G1 (n=10), not suspended – a 15 day experiment; G2 (n=10), suspended by the tail – a 15 day experiment and, G3 (n=10), suspended by the tail – a 36 day experiment. , The animals have been submitted to the osteotomy in both tibias and to the US application (1,5 MHz frequency, cycle 1:4, 30mW/cm2), on the right (twelve sessions of 20 minutes). G3 was only osteotomized after the 21st day of suspension. DPX-Lunar™ densitometer, Digora digital system and Image J computer program were used for densitometrical analysis; for the mechanical assay, the universal machine of EMIC assay was used. The results for Bone Mineral Content (g), Area (cm²), Bone Mineral Density (g/cm²) and Bone Density (mmAl) observed in tibias, as well as Maximum Power (N), and Rigidity (x103N/m) did not show any significant differences (treated versus control of each group), possibly due to shorter treatment time as regards the studies found in literature. Concluding that the low power ultrasound not accelerated the process of consolidating bone.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Alterações da densidade mineral óssea em vértebras de ratos wistar submetidos à ausência de carga nos membros pélvicos

The suspension of rats by the tail model is used to investigate the behavior of bone in animals unable to move around. Bone is an adaptative tissue that develops in structure and function, among other factors, in response to mechanical forces applied to it and metabolic demands that it will suffer. The absence of mechanical forces and deformation of bone that occurs causes a decrease in calcium deposition in the absence of stimuli on osteoblasts and osteocytes, favoring the action of osteoclasts, making bones weak and brittle. Therefore, the mechanical action is necessary to stimulate local bone response and thus provide growth and remodeling. The aim of this study was to evaluable by radiographic densitometry, the tail suspension for 15 and 36 days alter the bone mineral density of cervical vertebrae (C3), thoracic (T6) and lumbar (L1 and L3) of Wistar rats. Thirty Rattus norvegicus albinus, adult, male, Wistar strain, average body mass ± 350g, were divided into 3 groups: control (n = 10) - not suspended; S15 (n = 10) - suspended for 15 days and S36 (n = 10) - suspended for 36 days. For densitometric analysis vertebrae were radiographed, scanned, digitized and analyzed by the computer program ImageJ®. There was a statistically significant increase in bone mineral density in group S15, probably by the restlessness of the animals to the suspension, with a decrease in group S36, and this hypothetically is linked to the accommodation of the rats, concluding that the tail suspension altered bone mineral density in first time with a decrease over time

Biological control of Anopheles darlingi, Aedes aegypti and Culex quinquefasciatus larvae using shrimps

Mosquitoes can act as vectors of important diseases such as malaria, dengue, Zika virus, yellow fever, Chikungunya and Mayaro fever, in addition to filariasis. The use of insecticides, larvicides, bed nets and repellents, besides the use of drugs as chemoprevention and the treatment of the sick are currently the pillars of the control of these vectors. We studied the biological control against of Anopheles darlingi, Aedes aegypti and Culex quinquefasciatus larvae using shrimps of the species M. pantanalense, M. amazonicum, M. brasiliense and M. jelskii. Larvae of mosquitoes were collected from the breeding environment and placed in a 500 and 1000 l tank containing 60 shrimps/m2. The predatory activity was evaluated for 30 days and, in all groups it was observed that 100% of the larvae were consumed in few minutes. In the environment, these same species of crustaceans were released in water bodies with the presence of larvae of these insects. In just 72 h there was a marked reduction of the larvae in the release sites of shrimps. Similarly, there was a reduction in the number of adult mosquitoes caught near the breeding sites, allowing to infer that, in places where the crustaceans were released, the predatory activity on the larvae of mosquitoes was sufficient to reduce the number of adult mosquitoes p ≤ 0,05. This is the first description of the predatory activity of M. pantanalense, M. amazonicum, M. brasiliense and M. jelskii on An. darlingi, A. aegypti and C. quinquefasciatus larvae, constituting an important tool of biological control of these parasites-vectors