Saulo Petinatti Pavarini

Treadmill Exercise Protects Against Pentylenetetrazol-Induced Seizures and Oxidative Stress after Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of acquired epilepsy, and significant resources are required to develop a better understanding of the pathologic mechanism as targets for potential therapies. Thus, we decided to investigate whether physical exercise after fluid percussion injury (FPI) protects from oxidative and neurochemical alterations as well as from behavioral electroencephalographic (EEG) seizures induced by subeffective convulsive doses of pentylenetetrazol (PTZ; 35 mg/kg). Behavioral and EEG recordings revealed that treadmill physical training increased latency to first clonic and tonic-clonic seizures, attenuated the duration of generalized seizures, and protected against the increase of PTZ-induced Racine scale 5 weeks after neuronal injury. EEG recordings also revealed that physical exercise prevented PTZ-induced amplitude increase in TBI animals. Neurochemical analysis showed that exercise training increased glutathione/oxidized glutathione ratio and glutathione levels per se. Exercise training was also effective against alterations in the redox status, herein characterized by lipid peroxidation (thiobarbituric acid reactive substances), protein carbonyl increase, as well as the inhibition of superoxide dismutase and Na⁺,K⁺-ATPase activities after FPI. On the other hand, histologic analysis with hematoxylin and eosin revealed that FPI induced moderate neuronal damage in cerebral cortex 4 weeks after injury and that physical exercise did not protect against neuronal injury. These data suggest that the ability of physical exercise to reduce FPI-induced seizures is not related to its protection against neuronal damage; however, the effective protection of selected targets, such as Na⁺/K⁺-ATPase elicited by physical exercise, may represent a new line of treatment for post-traumatic seizure susceptibility.

Mortes súbitas em bovinos causadas por Amorimia exotropica (Malpighiaceae) no Rio Grande do Sul

Cases of sudden death in cattle were associated with the consumption of Amorimia (Mascagnia) exotropica and occurred in six ranches located in the mountainous region of Rio Grande do Sul and the metropolitan region of Porto Alegre, Brazil. Affected cattle were found dead with no history of previous clinical signs, or showed muscular tremors, falls, paddling, opistotonus, panting, and lateral recumbence after being induced to move, few minutes before death. Most cases were recorded between May and August. Nine cattle were necropsied and main gross findings were oral mucosae slightly cyanotic (3/9), mild to intermediate hydropericardium (3/9), epicardial petechiae and ecchymoses (5/9), clot within the left ventricle (4/9), lung edema (5/9), apart of abomasal and small intestinal reddened mucosa (6/9). Histologically, there was myocardial coagulation necrosis (9/9), which was characterized by cellular retraction, enhanced cytoplasmic eosinophilia, lack of cytoplasmic striations, intracytoplasmic vacuoles, nuclear piknosis, intranuclear vacuoles, chromatin marginalization and occasional nuclear karyorrhexis and karyolysis. There also were interstitial edema (3/9) and interstitial inflammatory infiltrate (mainly mononuclear) (7/9) in the heart, apart of multifocal vacuolar-hydropic degeneration in the epithelial cells of the distal convoluted tubules associated with pyknotic and eccentric nuclei in the kidneys of three cattle.

Fireweed (Senecio madagascariensis) poisoning in cattle

In a dairy cattle herd in southern Brazil, 7 out of 554 cattle were affected and died due to Senecio madagascariensis poisoning. Clinical, pathological, and epidemiological findings in the affected cattle were indistinguishable from those usually seen in poisoning caused by other Senecio species. The plant invaded extensive areas in heavily stocked paddocks. Senecio madagascariensis had been spreading in this farm for the last three years, with no control strategy, because neither the farmers nor the local veterinarian knew about the potential risks of this Sernecio species.In a dairy cattle herd in southern Brazil, 7 out of 554 cattle were affected and died due to Senecio madagascariensis poisoning. Clinical, pathological, and epidemiological findings in the affected cattle were indistinguishable from those usually seen in poisoning caused by other Senecio species. The plant invaded extensive areas in heavily stocked paddocks. Senecio madagascariensis had been spreading in this farm for the last three years, with no control strategy, because neither the farmers nor the local veterinarian knew about the potential risks of this Sernecio species.

Trema micrantha toxicity in horses in Brazil

After ingesting green leaves of T. micrantha, 2 horses showed apathy, locomotor deficit, blindness, recumbency, paddling, coma and death. The main gross findings were scattered haemorrhages, enhanced lobular pattern of the liver, and cerebral oedema. Histological changes included disseminated haemorrhages, massive hepatocellular necrosis, neuronal degeneration, Alzheimer type II astrocytes and cerebral perivascular oedema. Clinicopathological findings which were comparable with those observed in Trema micrantha poisoned ruminants, associated with epidemiological evidence suggested the diagnosis.Trema micrantha poisoning should be evaluated as a possible cause in the diagnosis of equine hepatopathy and occasional secondary encephalopathy.

Amorimia exotropica poisoning as a presumptive cause of myocardial fibrosis in cattle

The current study reports the investigation on the cause of sudden deaths associated with cardiac fibrosis in cattle in northern Rio Grande do Sul, Brazil. The exclusion of known causes of bovine cardiac fibrosis as well as the absence of the plants in that region whose consumption has already been linked to the disorder motivated this investigation. The condition, which was attributed to the consumption of Amorimia exotropica, affected draft oxen, most of which died suddenly without showing any clinical signs during usual management or work. Globular hearts with white foci at their cut surfaces were the main gross findings, which corresponded microscopically from multifocal to coalescent areas of myocardial fibrosis. To confirm the condition, A. exotropica from the ranches where cattle died from the disease was dosed to rabbits, which showed similar lesions to those seen in dead cattle after receiving 10 doses of 3.6 g/kg at 4-day intervals. Electron microscopy on rabbit tissues revealed severe tumefaction of the cardiomyocytes associated with mitochondrial swelling, displacement, and rupture of the mitochondrial crests, and of the bundles of myofibrils, apart from large glycogen deposits within the sarcoplasm. It is suggested that mitochondrial changes triggered alterations that lead to cardiac fibrosis and that all of these changes were induced by A. exotropica cardiotoxicity.

Senecio brasiliensis (Asteraceae) poisoning in Murrah buffaloes in Rio Grande do Sul 1

Descreve-se a ocorrencia de um surto de intoxicacao espontânea por Senecio brasiliensis em bufalos Murrah (Bubalus bubalis) em uma propriedade localizada no municipio de Nova Prata, Estado do Rio Grande do Sul, no periodo de junho a agosto de 2006. De um total de 90 bufalos, 13 adoeceram e 11 morreram. Os animais eram mantidos em areas de pastoreio altamente infestadas por S. brasiliensis. Os principais sinais clinicos relatados foram letargia, apatia, emagrecimento progressivo, diarreia e decubito permanente. Necropsia foi feita em dois dos 11 animais mortos. As lesoes foram caracteristicas de intoxicacoes por alcaloides pirrolizidinicos. A grande quantidade da planta, forte estiagem e desnutricao consequente foram os principais achados epidemiologicos associados com a mortalidade.

Clinical and pathological insights into Johne′s disease in buffaloes

Alternative diagnostic tools and interesting epidemiological assumptions were associated with an outbreak of Johne′s disease. In a buffalo herd infected with paratuberculosis, seven clinically affected animals and 21 animals with anti-Mycobacterium avium ELISA reactions were identified. Total herd included 203 buffaloes. Most lesions were comparable to those described in buffaloes and cattle affected by Johne′s disease. Water buffalo behaviors such as communal nursing and allosuckling may be additional risk factors for this disease. Detection of positive Ziehl–Neelsen staining and anti-M. avium immunolabeling in rectal biopsies from one buffalo with paratuberculosis are highlighted as auxiliary diagnostic tools for Johne′s disease in live animals.

Aspiration pneumonia associated with oesophageal myonecrosis in sheep due to BTV infection in Brazil

BLUETONGUE is an arthropod-borne disease of ruminants caused by the bluetongue virus (BTV). The distribution of BTV depends on the distribution of Culicoides species insect populations and appropriate climatic conditions. Except for some sheep breeds, most BTV infections in domestic ruminants are

Equine intestinal pythiosis in Southern Brazil

The most common clinical presentation of the disease is the cutaneous form, which is characterized by granulomatous ulcerative lesions and yellow to tan necrotic masses, also termed ‘kunkers’ (Santurio et al., 2006). Nevertheless, isolated cases of enteric pythiosis have sporadically been described in horses (Brown and Roberts, 1988; Morton et al., 1991; Purcell et al., 1994), cats (Barker et al., 1993), and most commonly in dogs (Dykstra et al., 1999). The pathogenesis of intestinal pythiosis is not completely understood. It has been suggested that previous injury caused by vegetal material or pathogenic agents on the intestinal mucosa may be important predisposing factors (Morton et al., 1991; Purcell et al., 1994). Alternatively, the disease could also occur by active penetration of the agent (Brown and Roberts, 1988). This case report describes the pathologic and immunohistochemical findings observed in a case of equine intestinal pythiosis. An eight-year-old English Thoroughbred mare was presented for clinical examination with a

Surto de babesiose cerebral em bovinos no Estado do Rio Grande do Sul

An outbreak of cattle mortality due to Babesia bovis infection in the county of Picada Cafe, Rio Grande do Sul, southern Brazil, in April 2007 is described. Twenty eight heifers (50.9%) died, out of a herd of 55 animals, in five days. The disease occurred approximately 20 days after heifers were transferred to this farm. The clinical signs included fever, anemia, aggressiveness, incoordination, petechiae in the mucous membranes and death after 1 to 2 days. The necropsy revealed pale mucous membranes, splenomegaly, enlarged and yellowish liver, congested and edematous gall bladder containing viscous granular bile. The kidneys and urine were dark red. The gray matter of cerebrum and cerebellum had a characteristic cherry-pink color. Hemorrhage was seen in the epicardium and endocardium. The histological findings consisted of hemoglobinuric nephrosis, paracentral hepatic necrosis, bile stasis, spleen congestion. The gray matter of the brain exhibited congestion with erythrocytes parasitized by Babesia bovis, which were also seen in the brain impression smear. The death of 28 heifers in 5 days was attributed to inadequate immunity against the parasite. The application of imidocarb dipropionate in animals presenting the initial stage of the disease and in all other animals of the herd was adopted as preventive treatment and no new cases of the disease happened in the next two months, when they were sent to slaughter.