Stefano Carlo Filippo Hagen

Predictive Criteria to Study the Pathogenesis of Malaria-Associated ALI/ARDS in Mice

Malaria-associated acute lung injury/acute respiratory distress syndrome (ALI/ARDS) often results in morbidity and mortality. Murine models to study malaria-associated ALI/ARDS have been described; we still lack a method of distinguishing which mice will develop ALI/ARDS before death. This work aimed to characterize malaria-associated ALI/ARDS in a murine model and to demonstrate the first method to predict whether mice are suffering from ALI/ARDS before death. DBA/2 mice infected with Plasmodium berghei ANKA developing ALI/ARDS or hyperparasitemia (HP) were compared using histopathology, PaO2 measurement, pulmonary X-ray, breathing capacity, lung permeability, and serum vascular endothelial growth factor (VEGF) levels according to either the day of death or the suggested predictive criteria. We proposed a model to predict malaria-associated ALI/ARDS using breathing patterns (enhanced pause and frequency respiration) and parasitemia as predictive criteria from mice whose cause of death was known to retrospectively diagnose the sacrificed mice as likely to die of ALI/ARDS as early as 7 days after infection. Using this method, we showed increased VEGF levels and increased lung permeability in mice predicted to die of ALI/ARDS. This proposed method for accurately identifying mice suffering from ALI/ARDS before death will enable the use of this model to study the pathogenesis of this disease.

Experimental infection with Neospora caninum in pregnant bitches

In this study, transplacental transmission of Neospora caninum in bitches at different stages of pregnancy was evaluated. Three bitches were inoculated in the 3rd week and three in the 6th week of gestation with 10(8) tachyzoites of N. caninum (Nc-1 strain). All the infected bitches and at least one of their offspring presented anti-N. caninum antibodies according to the indirect fluorescent antibody test (IFAT > 400). The pups and their mothers were sacrificed and tissues from the central nervous system (CNS), popliteal lymph nodes, skeletal muscle, brain, lungs, heart and liver were analyzed for the presence of N. caninum using the nested polymerase chain reaction (nested PCR), restriction fragment length polymorphism (RFLP) and immunohistochemistry (IHC). The parasite was found in the pups in lymph node, CNS, heart and liver tissues using nested PCR. There was no difference in perinatal mortality between the offspring from bitches infected in the 3rd week of gestation (60%) and in the 6th week (53.8%).

Radial shock wave therapy in dogs with hip osteoarthritis

OBJECTIVE The study aims were to evaluate the effects of radial shock wave therapy (RSWT) in dogs with hip osteoarthritis (OA) using clinical assessment and kinetic analysis. METHODS Thirty dogs diagnosed with bilateral hip OA and 30 healthy dogs were used. In OA dogs, one limb was randomly selected for treatment with RSWT while the contralateral limb served as an untreated control. Dogs were evaluated while walking on a pressure walkway. Peak vertical force (PVF) and vertical impulse (VI) were documented; symmetry index (SI) was also calculated. Blinded clinical evaluation was performed using a visual analogue scale (VAS). Owner perception data regarding levels of physical activity were also collected. The RSWT protocol (2000 pulses, 10 Hz, 2-3.4 bars) consisted of three weekly treatment sessions (days 1, 8 and 16). Follow-up data were collected 30, 60 and 90 days after the first session. Data were compared between time points, groups and limbs pairs. RESULTS At the end of the experimental period, mean PVF and VI values had increased (25.9 to 27.6%BW and 2.1 to 12.7%BW × s respectively) in treated limbs, with no significant differences in control limbs; SI values suggest improvement. Mean PVF and VI remained lower in the treated compared to the healthy group following treatment. The VAS scores suggested improvement in pain and lameness in treated dogs. Owner perception data suggested improved levels of physical activity following treatment. CONCLUSIONS AND CLINICAL SIGNIFICANCE Outcomes of this study suggested beneficial effects of RSWT in dogs with hip osteoarthritis.

Patellar instability following experimental medial patellar desmotomy in horses.

A controlled study was designed in order to evaluate the effects of medial patellar desmotomy (MPD), combined with exercise restriction, on clinically and radiographically normal femoropatellar joints, and to identify the patellar instability by radiographic examination. MPD was performed on the right hind limb and the horses were rested for 120 days. Both hind limbs were radiographed before surgery and at 15, 30, 60, 90, and 120 days after MPD, obtaining lateromedial, flexed lateromedial, caudocranial and cranioproximal-craniodistal (skyline) views. The femorotibial and femoropatellar angles were assessed on the lateromedial views, and the distance between the medial and lateral cortex of the femur, and the distance between the medial cortex of the femur and the lateral border of the patella were evaluated in the caudocranial views. An increase in the angle between the proximal articular surface of the patella and the cranial distal surface of the femur along with enthesophyte formation and lateral deviation of the patella were found on the radiographs of the right stifles after MPD. Therefore, MPD leads to patellar instability, which can be demonstrated by the radiographic changes. The 120 days rest did not prevent the lesions caused by postsurgical patellar instability.

Metabolic profile and ruminal and abomasal pH in sheep subjected to intravenous ranitidine

A ovinocultura brasileira tem se intensificado, o que predispoe os animais a maior incidencia de transtornos digestivos, como a ulcera de abomaso. A ranitidina e utilizada na prevencao e tratamento desta afeccao, no entanto ha pouca informacao sobre a indicacao parenteral deste farmaco para ruminantes adultos. Sao escassas as informacoes a respeito das alteracoes metabolicas e do comportamento do sistema digestorio associados ao seu uso. Para este estudo foram utilizados cinco ovinos, machos, higidos, providos de cânula ruminal e abomasal. O delineamento foi Quadrado Latino 5x5 com arranjo fatorial de tratamentos 2x2+1. Os ovinos tratados com as doses de 1 e 2mg/kg de ranitidina administrada por via intravenosa a cada 8 ou 12 horas foram comparados aos animais do grupo controle, tratados por via intravenosa com 1mL de solucao fisiologica por 25 kg a cada 12 horas. Maiores concentracoes de proteina total e hemoglobina, maiores atividades de AST e aumento do pH abomasal por ate 150 minutos foram observados em todos os animais que receberam o farmaco, independentemente de dose e frequencia. Os animais tratados a cada 12 horas mostraram diminuicao do numero de leucocitos comparados aos animais tratados a cada 8 horas e aos animais do grupo controle. Observou-se aumento das concentracoes de creatinina nos animais tratados a cada 8 horas. Os tratamentos 1mg/kg a cada 8 horas e 2mg/kg a cada 12 horas aumentaram o numero de hemacias e diminuiram as concentracoes sericas de pepsinogenio. Todos os protocolos estudados foram seguros para ovinos sadios, porem 1mg/kg de ranitidina a cada 8 horas e 2mg/kg a cada 12 horas mostraram-se mais eficientes quanto a protecao gastrica.

Avaliação ultrassonográfica de linfonodos na pesquisa de metástases de neoplasia mamária em cadelas

Evaluation of lymph nodes is part of the staging of the mammary tumors and helps to establish a prognosis and therapy. B-mode ultrasonography was used to evaluate size, edge, nodal borders, shape, architecture, echotexture and echogenicity of lymph nodes and Doppler ultrasonography to evaluate the quantity and distribution of the vessels. The aims of this work were to identify which ultrasound features can be used to classify a lymph node as metastatic or non-metastatic; to establish its accuracy as a useful tool to this differentiation, and to establish procedures that permit the reproducibility of the results. Sixty seven lymph nodes of 30 female dogs with mammary tumors were examined by ultrasound and classified as metastatic or non-metastatic. The ultrasonographic diagnostic impression was confronted with the histopathologic results. The ultrasonographic classification of the lymph nodes was correct in 92.5% of the cases, with sensibility of 94.1%, specificity of 92%, positive predictive value of 0.8, and negative predictive value of 0.9787.The characteristics of the nodes to classify them as metastatic or non metastatic were registered. Ultrasound imaging of regional lymph nodes is important to detect metastases and it is suggested that it becomes a regular procedure in the staging of canine mammary tumors.

Avaliação pós-operatória, através de exame clínico, laboratorial e ultra-sonográfico, de eqüinos submetidos à toracotomia experimental

Pertaining litterature does not usually foccus on the possible consequences in the thoracic cavity of horses subjected to thoracotomy procedures. Ultrasound is not mentioned as a method of contrai in post-operatory evaluation, which is mostiy exclusively based on post-mortem examination. Six healthy equine were used in the experiment; surgical access to the right hemitorax was assured by controiled mechanical anesthesia. The thoracotomy in the equine was further evaluated by means of a complete clinicai examination, blood gas analysis, complete blood count and thoracic ultrasonography.The suture technique aiso revealed itself efficient and the animais exbited no sings of respiratory distress, pneumotorax or thoracic wall suture dehiscense. The complete clinicai examination, pH, blood gases as well as blood cell count, did not show any significant changes at the pos-operative period. The ultrasonographic exam allowed the evaluation of pleural fluid appearance and quantity, changes of visceral pleura, presence of pneumotorax and subpleural changes.

Histological and Radiographic Evaluation of Equine Bone Structure after Implantation of Castor Oil Polymer

OBJECTIVE  The main purpose of this study was to evaluate the characteristics of a vegetal polymeric biomaterial intended for bone substitution in horses and to investigate the responses of the equine third metacarpal bone to biomaterial implantation. MATERIALS AND METHODS  Six horses were submitted to osteotomy on the dorsal aspect of the left and right third metacarpal bones; one bone defect was randomly selected for treatment with biopolymer, while the other was left untreated and served as a control. Bone density was monitored radiographically after surgery and bone biopsy fragments were collected at the end of the 120-day follow-up period. Biopsy fragments were analysed using light and scanning electron microscopy. RESULTS  Mean bone density values (mmAL) were greater in control defects (16.33 ± 1.6) than in polymer-treated defects (14.17 ± 1.7) at 120 days (p = 0.027). Light microscopy revealed greater percentages of new bone formation in control defects (50.15 ± 14.8) than in polymer treated defects (26.94 ± 12.1) at 120 days (p < 0.0001). Scanning electron microscopy analysis suggested a similar quality of pre-existing bone and new bone formed in the presence of biomaterial. CLINICAL SIGNIFICANCE  The absence of adverse reactions supports biomaterial biocompatibility and osteoconducting capacity and suggests the castor oil polymer is a suitable bone substitute for the treatment of bone defects in horses.

Índices e dimensões ecocardiográficas de equinos da raça Mangalarga Marchador

Aiming to establish the echocardiographic reference values of cardiac dimensions and indexes in horses of the Mangalarga Marchador breed, 80 horses, weighing 320 to 500 kg, that were divided in four group by gender and age, as follows: 1.6 to 4-year-old females (G1), more than 4-year-old females (G2), 1.6 to 4-year-old males (G3) and above 4-year-old males (G4), were evaluated by standardized technique. The evaluation consisted of B-mode and guided M-mode echocardiography, by which the following measurements were made: from the right cardiac window, by B- and M-mode: systolic and diastolic RVID, IVS, LVID, LVFW, Aod, FS% and EF%, by B-mode: Las, Aod, and Las/Aod, by M-mode: S-E point, from left cardiac window, by B- and M-mode: LVIDs, LVIDd, FS% and EF% and by B-mode: Las. There were statistic differences between means of the four groups for the following parameters: Aod, Las, RVIDs, RVIDd, IVSs, IVSd, LVIDs, LVIDd, LVFWs, LVFWd, Vs, Vd. There were statistic correlations between Aod, Las, IVSs, IVSd, LVFWs, LVFWd, Vd and age; Aod, Las, IVs, IVSd, LVIDd, LVFWs, Las/Aod and bodyweight and thoracic perimeter; and Aod, LAs, IVSs, IVSd, LVIDs, LVFWs, Vd and height. Sex and age group influenced the reference values for the Mangalarga Marchador horses; males above 4 years presented higher ventricular measurement values. Height, weight and age of the horses influenced in the same way the results, all being positively related to the size of the cardiac structure.

Oxidative metabolism and muscle biochemical profile of polo horses supplemented with an ADE vitamin complex

Horses used for the game of polo experience abrupt and frequent changes in exercise intensity. To meet this variable energy demand, the horses use both aerobic and anaerobic pathways in varying proportions and intensities. In this context, there must be a balance between the formation of reactive oxygen species (ROS) and the action of antioxidants to prevent oxidative stress and its consequences. The effect of supplementation with an ADE vitamin complex on oxidative metabolism was evaluated in 18 crossbred horses randomly divided between a treated group (TG) and a control group (CG). The TG animals received the ADE vitamin complex (1mL/50 kg of body weight) by deep intramuscular injection at 30 and 15 days before the game. The CG horses received 10ml of saline by the same administration route and schedule. During the polo match, the animals played for a total of 7.5 min. Blood samples were collected on the same days as the treatments were administered, and immediately before and at 15, 90 and 180 minutes after the game. The concentrations of creatine phosphokinase (CK), lactate dehydrogenase (LDH), lactate, glucose, aspartate aminotransferase (AST), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in the blood samples. After the game, the TG demonstrated higher levels of AST, lactate and glucose than the CG, suggesting more efficient energy use by the treated animals. The higher GSH and lower lactate levels in the TG before the game suggest the presence of a greater antioxidant supply in the treated animals. The maintenance of the MDA levels indicates that neither of the groups exhibited oxidative stress.