Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s-1·MBq-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging 99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using 99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

Hematologia e bioquímica sérica de equinos de concurso completo de equitação em treinamento / Hematology and serum biochemistry of event horses in training

Avaliaram-se a hematologia e a bioquímica sérica em equinos de concurso completo de equitação (CCE) em treinamento durante testes de esforço incremental em esteira ergométrica de alta velocidade. Foram utilizados 16 equinos em delineamento experimental inteiramente ao acaso com quatro tratamentos e quatro repetições em esquema de parcelas subdivididas, utilizando-se como fontes de variação nos tratamentos a idade e o histórico de treinamento em CCE. As parcelas foram constituídas pelos testes incrementais realizados nas fases inicial e final do treinamento. As subparcelas foram representadas pelos tempos de avaliação e coletas. Os equinos do grupo experimental novos iniciantes apresentaram valor médio do hematócrito de 43,24%, sendo inferior ao hematócrito do grupo adultos iniciantes, 45,63%, novos experientes, 46,39%, e competidores, 47,74%. Houve diferença (P<0,05) entre os testes físicos realizados nas fases inicial e final do treinamento, com redução na concentração plasmática de glicose, de 112 para 98,88mg/dL, nas concentrações séricas de creatinina, de 1,41 para 1,29mg/dL, e de proteínas totais, de 6,52 para 6,38g/dL, na contagem de monócitos, de 0,54 para 0,48 10³/mm³, e com aumento na concentração plasmática de lactato, de 3,31 para 3,79mmol/L, na concentração sérica de ácido úrico, de 1,44 para 1,77mg/dL, no hematócrito, de 44,19 para 46,90%, na concentração de hemoglobina, de 14,33 para 15,10g/dL, e na contagem de leucócitos totais, de 9,26 para 9,61 10³/mm³. O treinamento dos equinos de CCE aumentou o condicionamento físico dos equinos, com maior capacidade de metabolização do lactato após o exercício e aumento nos valores basais do hematócrito e da concentração de hemoglobina.

Was evaluated the hematology and serum biochemistry in event horses (CCE) in training during incremental treadmill tests. Sixteen horses were used in a completely randomized design with four treatments and four repetitions in subdivided parcels, using age and previous history of training in events as sources of treatment variation. The parcels constituted of incremental treadmill tests performed at the beginning and end of training. The subparcels were represented by the time of evaluation and collection of samples. The equines of new beginners group had mean hematocrit value of 43.24%, being lower than the hematocrit of adult beginners group, 45.63%, new experienced group, 46.39%, and competitors group, 47.74%. There were differences (P<0.05) between the tests performed at the beginning and end of training, with reduction in glucose plasma concentration, from 112 to 98,88mg/dL, in seric concentration of creatinine, 1.41 to 1.29mg/dL, and total protein, 6.52 to 6.38 g/dL, in monocyte count, 0.54 to 0.48 10³/mm³, and an increase of lactate plasma concentration, from 3.31 to 3.79mmol/L, in seric concentration of uric acid, 44 to 1.77mg/dL, in hematocrit, 44.19 to 46.90%, in hemoglobin concentration, 14.33 to 15.10 g/dL, and blood cell count, 9.26 to 9.61 10³/mm³. The training of event horses improves physical performance of horses, with increased capacity of lactate metabolism after exercise and increased basal hematocrit and hemoglobin concentration.

Avaliaçäo da sensibilidade de linhagens celulares ao parvovírus suíno (PVS) / Sensibility evaluation of cell lines to porcine parvovirus - PPV

Foram determinadas as sensibilidades de três linhagens celulares (ST, SK6 e PK15) a duas amostras de parvovírus suíno (PVS-1 e NADL-2) e efetuadas as curvas de replicaçäo viral, através dos efeitos citopáticos e títulos hemoaglutinantes determinados com intervalo de 12 h, durante um período de estudo de 120 h. A maior sensibilidade foi verificada pela linhagem celular ST, seguida pela célula SK6, sendo a célula PK15 a menos sensível