Plasma and tear concentrations of antibiotics administered parenterally to cattle

Chloramphenicol, erythromycin, gentamicin, oxytetracycline, penethamate and procaine benzyl penicillin were administered parenterally to cattle and the concentrations of these antibiotics in plasma and tears were assayed microbiologically. Concentrations in plasma and tears were significantly correlated for all antibiotics tested but the concentration of antibiotic in tears and the tear flow rate were not correlated. Lipophilic drugs diffused into the tears in higher concentrations than did drugs which were not lipophilic. Concentrations of lipophilic but not hydrophilic antibiotics in tears could be predicted from the Henderson-Hasselbach equation. In cattle, it is possible through parenteral administration of chloramphenicol, erythromycin, gentamicin or oxytetracycline to achieve antibiotic concentrations in the tears which are bacteriostatic to Moraxella bovis, a primary aetiological agent of infectious bovine keratoconjunctivitis

Hernioplastia diafragmática em cão com pericárdio bovino conservado em solução supersaturada de açúcar Diaphragmatic hernioplasty in dogs with bovine pericardium preserved in supersaturated sugar solution

Foram utilizados sete cães adultos, três machos e quatro fêmeas, sem raça definida, com pesos entre 10 e 22kg, para avaliação do processo cicatricial do músculo diafragma, na presença do implante de pericárdio bovino conservado em solução supersaturada de açúcar a 300%. Foi criado um defeito na porção muscular do hemidiafragma esquerdo de dimensões 8,0×5,0cm. Após a toracotomia no oitavo espaço intercostal esquerdo, o implante heterógeno foi fixado com fio poliamida nº 3-0 por meio de sutura simples contínua. Decorrido o período pré-estabelecido de pós-operatório, os animais foram submetidos a exames radiográficos simples e contrastado e a estudos macroscópico e histológico. Na avaliação radiográfica, foi verificada presença das silhuetas diafragmática e cardíaca, sem evidências de vísceras abdominais no interior do tórax. Macroscopicamente, notou-se a formação de tecido conjuntivo fibroso semi-transparente que ocluia o defeito diafragmático. O segmento de pericárdio bovino conservado em solução supersaturada de açúcar a 300%, em temperatura ambiente, é substituído por uma fina camada de tecido conjuntivo fibroso e promove a restauração do defeito no músculo diafragma de cão.<br>Seven adult mongrel dogs, three males and four females, weighting between 10 and 22kg were used to evaluate the diaphragmatic muscle healing process. A defect of 8.0×5.5cm was created at the muscular portion of the left hemidiaphragm, through a thoracotomy at the eighth left intercostal space. A segment of bovine pericardium, preserved in 300% sugar solution, was implanted in the diaphragmatic defect. The heterologous implant was sutured with 3.0 polyamide using simple continuous suture. After the observation period, radiologic analysis and macroscopic and histopathologic evaluations were performed. Upon radiographic examination, there was no evidence of interruption of diaphragmatic outline or increased radiopacity at the implantation site. Histologically, fine connective tissue occluded the diaphragmatic defect. Bovine pericardium preserved in 300% supersaturated sugar solution at room temperature is replaced by a fine layer of connective fibrous tissue and promote repair of large diaphragmatic defects in dogs

Prospects for γ\gamma-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array

International audienceGalaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at gamma-ray energies and are predicted to be sources of large-scale gamma-ray emission due to hadronic interactions in the intracluster medium. We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. We perform a detailed spatial and spectral modelling of the expected signal for the DM and the CRp components. For each, we compute the expected CTA sensitivity. The observing strategy of Perseus is also discussed. In the absence of a diffuse signal (non-detection), CTA should constrain the CRp to thermal energy ratio within the radius $R_{500}$ down to about $X_{500}10^{27}$s for DM masses above 1 TeV. These constraints will provide unprecedented sensitivity to the physics of both CRp acceleration and transport at cluster scale and to TeV DM particle models, especially in the decay scenario

Prospects for γ\gamma-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array

International audienceGalaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at gamma-ray energies and are predicted to be sources of large-scale gamma-ray emission due to hadronic interactions in the intracluster medium. We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. We perform a detailed spatial and spectral modelling of the expected signal for the DM and the CRp components. For each, we compute the expected CTA sensitivity. The observing strategy of Perseus is also discussed. In the absence of a diffuse signal (non-detection), CTA should constrain the CRp to thermal energy ratio within the radius $R_{500}$ down to about $X_{500}10^{27}$s for DM masses above 1 TeV. These constraints will provide unprecedented sensitivity to the physics of both CRp acceleration and transport at cluster scale and to TeV DM particle models, especially in the decay scenario