Investigation of Salmonella spp. in free-range chickens (Gallus gallus domesticus) in Southern Rio Grande do Sul / Pesquisa de Salmonella spp. em galinhas coloniais (Gallus gallus domesticus) no sul do Rio Grande do Sul

Salmonelose é uma doença causada por bactérias do gênero Salmonella, com importância para saúde pública e animal. Dentre os sorotipos hospedeiro-específicos, destaca-se o Gallinarum, que possui os biovares Gallinarum e Pullorum adaptados às aves e amplamente difundidos pelo mundo. Os dados sobre a ocorrência de Salmonella spp. em criações avícolas alternativas no Brasil são escassos. O objetivo deste estudo foi pesquisar a ocorrência de Salmonella spp. em galinhas coloniais encaminhadas para necropsia ao LRD/FV/UFPel. Foram realizadas análises histopatológicas, microbiológicas e moleculares das colônias bacterianas isoladas de 12 amostras de órgãos de galinhas domésticas dos municípios de Pelotas e Piratini, no Rio Grande do Sul. Na análise microbiológica, foram isoladas bactérias do gênero Salmonella sorotipo Gallinarum das 12 amostras, sendo 10/12 bioquimicamente compatíveis com biovar Gallinarum e 2/12 com biovar Pullorum. Na análise molecular PCR 11/12, 91,7% foram identificadas genotipicamente como Salmonella spp. O presente estudo demonstrou uma elevada frequência de isolamento de Salmonella Gallinarum biovar Gallinarum em aves sintomáticas criadas em regime extensivo. Além disso, os dados epidemiológicos das aves analisadas demonstram que a infecção por Salmonella Gallinarum nesses casos está associada ao contato com aves silvestres e falhas de manejo sanitário.(AU)

Outbreak of avian aspergillosis in colonial-bred chicks (Isa Brown) in southern Rio Grande do Sul - case report / [Surto de aspergilose aviária em pintainhas (Isa Brown) de criação colonial na região sul do Rio Grande do Sul - relato de caso]

In this study we describe the epidemiology, clinical signs, and pathology of an outbreak of avian aspergillosis in alternative breeding in the southern region of Rio Grande do Sul, Brazil. Between the fifth and tenth day of life, 360 chicks from a flock of 4000 developed unspecific clinical signs and died. The birds were housed in a reused aviary litter, without previous treatment. In 11 six-day-old female ISA Brown chicks (Gallus gallus domesticus), necropsy revealed firm, yellowish-white, multinodular lesions extending from the pleura to the lung parenchyma. Histologically, a granulomatous, multifocal to coalescent pneumonia was observed. Granulomas were characterized by central necrosis, with heterophil and epithelioid macrophage infiltration and presence of countless Y-shaped intralesional septate hyphae morphologically compatible with Aspergillus spp. The diagnosis through isolation confirmed Aspergillus fumigatus. We highlight the importance of aspergillosis as a primary cause of diseases in the respiratory tract of young birds in alternative breeding. Measures to prevent aspergillosis mainly regarding the reuse of aviary litter are essential in poultry husbandry to prevent economic losses, reduce environmental contamination and mitigate the potential risk to public health.(AU)

Descrevem-se os aspectos epidemiológicos e patológicos de um surto de aspergilose aviária em criação alternativa na região sul do Rio Grande do Sul, Brasil. De um lote de 4000 pintainhas, entre o quinto e o 10º dia de vida, 360 aves apresentaram sinais clínicos inespecíficos e morreram. As aves foram alojadas em cama reutilizada do aviário, sem tratamento prévio. Na necropsia de 11 pintainhas (Gallus gallus domesticus), fêmeas, seis dias de idade da linhagem Isa Brown, foram observadas no pulmão lesões multinodulares, branco-amareladas e firmes, que se estendiam da pleura ao parênquima. Histologicamente foi observada pneumonia granulomatosa, multifocal a coalescente. Os granulomas eram caracterizados por necrose central, com infiltrado inflamatório de heterófilos, macrófagos, células epitelioides com presença de inúmeras hifas septadas intralesionais, semelhantes à letra "Y", morfologicamente compatíveis com Aspergillus spp. O diagnóstico foi confirmado pelo isolamento de Aspergillus fumigatus. Alerta-se para a importância da aspergilose como causa primária de afecções no trato respiratório de aves jovens em criações alternativas. Medidas preventivas relacionadas ao manejo dessas aves são indispensáveis principalmente quanto à reutilização da cama dos aviários, a fim de evitar perdas econômicas, reduzir a contaminação ambiental e o potencial risco à saúde pública.(AU)

Meningioma microcístico com metástase pulmonar em canino: relato de caso / Microcystic meningioma with pulmonary metastasis in canine: case report

Meningiomas são os principais tumores primários do sistema nervoso central (SNC) que afetam cães e gatos. Na maioria dos casos, são neoplasias benignas, geralmente expansivas, causando compressão do SNC, e raramente fazem metástase para outros órgãos. O presente trabalho tem como objetivo relatar a ocorrência de um meningioma microcístico com metástase pulmonar em um canino de 11 anos de idade, com sinais clínicos de andar cambaleante, compressão da cabeça contra objetos, agitação, salivação e agressividade. Na necropsia, foram observadas, no encéfalo, massas bem delimitadas pardo-avermelhadas, firmes, de aspecto granular, localizadas no córtex parietal e nos núcleos da base. Inúmeras micronodulações de aspecto semelhante foram observadas no pulmão. Histologicamente observaram-se nódulos formados por células neoplásicas fusiformes, com núcleos grandes e alongados e nucléolos evidentes, dispostas de forma frouxa, formando vacúolos e microcistos. À imuno-histoquímica, o meningioma apresentou marcação fortemente positiva para citoqueratina e negativa para vimentina. Por meio da histopatologia e da imuno-histoquímica, foi possível estabelecer a classificação histológica de meningioma microcístico, bem como diferenciá-lo de outras doenças que cursam com sinais nervosos.(AU)

Meningiomas are the main tumors of the central nervous system (CNS) affecting dogs and cats. In most of the cases they are benign neoplasms, usually expansive, causing compression of the CNS and rarely metastasize to other organs. We describe the occurrence of a microcystic meningioma with pulmonary metastasis in an 11 - year - old canine with clinical signs of staggering gait, head compression against objects, agitation, salivation and aggressiveness. At necropsy, well-defined, firm, granular-looking masses located in the parietal cortex and nuclei of the base were observed in the encephalon. Numerous micronodulations of similar appearance were observed in the lung. Histologically, nodules formed by spindle neoplastic cells with large, elongated nuclei and evident nuclei were loosely arranged, forming vacuoles and microcysts. Immunohistochemistry were strongly positive for cytokeratin and negative for vimentin. Through the histopathology and immunohistochemistry, it was possible to establish the histological classification of microcystic meningioma, as well as to differentiate from other diseases that present with nervous signals.(AU)

Altered accelerator pedal control in a driving simulator in people with diabetic peripheral neuropathy.

AIM: To investigate whether the sensory-motor impairment attributable to diabetic peripheral neuropathy would affect control of the accelerator pedal during a driving simulator task. METHODS: A total of 32 active drivers, 11 with diabetic peripheral neuropathy (mean ± sd age 67±5.0 years), 10 with diabetes but no neuropathy (diabetes group; mean ± sd age 62±10 years), and 11 healthy individuals without diabetes (healthy group; mean ± sd age 60±11 years), undertook a test on a dynamometer to assess ankle plantar flexor muscle strength and ankle joint proprioception function of the right leg, in addition to a driving simulator task. The following variables were measured: maximal ankle plantar flexor muscle strength; speed of strength generation (Nm/s); and ankle joint proprioception (ankle repositioning error, degrees). In the driving simulator task, driving speed (mph), accelerator pedal signal (degrees) and the duration of specific 'loss-of-control events' (s) were measured during two drives (Drive 1, Drive 2). RESULTS: Participants with diabetic peripheral neuropathy had a lower speed of strength generation (P<0.001), lower maximal ankle plantar flexor muscle strength (P<0.001) and impaired ankle proprioception (P=0.034) compared to healthy participants. The diabetic peripheral neuropathy group drove more slowly compared with the healthy group (Drive 1 P=0.048; Drive 2 P=0.042) and showed marked differences in the use of the accelerator pedal compared to both the diabetes group (P=0.010) and the healthy group (P=0.002). Participants with diabetic peripheral neuropathy had the longest duration of loss-of-control events, but after one drive, this was greatly reduced (P=0.023). CONCLUSIONS: Muscle function, ankle proprioception and accelerator pedal control are all affected in people with diabetic peripheral neuropathy, adversely influencing driving performance, but potential for improvement with targeted practice remains possible.

Optic flow direction coding in area PEc of the behaving monkey.

The cortical representation of heading perception derives from several functional processes distributed across many cortical areas. The aim of the present study was to assess if the optic flow motion directions, expansion and contraction, differently modulate the firing activity of area PEc neurons. We determined the influence of the eye position and/or the spatial position of the focus of expansion (FOE) on this activity. Single neuron activity during radial optic flow stimulation was recorded in three behaving monkeys. The retinal FOE position and the spatial eye position were examined in order to study eye position's influence upon the directional selectivity for the radial stimuli. We observed that the neurons able to discriminate the retinotopic FOE position are differently modulated by expansion and contraction. One class of neurons exhibited a different preferred FOE position during expansion and contraction. A second class showed the same preferred position with similar firing activity in the two stimuli. A third class showed the same preferred position but different firing activity. Eye position affected the directional selectivity of most PEc cells. The main result of this study is that there is a continuum in cell modulation by optic flow direction, and it can be modified by the angle of gaze with respect to the FOE. These results shed light on potential cellular integrative mechanisms of area PEc in heading perception.

Raiva em bovinos na Região Sul do Rio Grande do Sul: epidemiologia e diagnóstico imuno-histoquímico / Rabies in cattle in southern Rio Grande do Sul: epidemiology and immunohistochemistry diagnosis

Foi realizado um estudo retrospectivo de casos de raiva paralítica em bovinos na área de influência do Laboratório Regional de Diagnóstico (LRD) da Faculdade de Veterinária, Universidade Federal de Pelotas (UFPel), ocorridos em 1978-2007. Foram estudados também 11 surtos de raiva observados em 2008-2010, na mesma região. Neste período morreram 42 animais de um total de 686 sob risco. A idade dos animais foi de 1-6 anos e o curso clínico de 4-14 dias. No estudo retrospectivo de 1978-2007 foram identificados 77 surtos ou casos isolados de raiva paralítica em bovinos. A morbidade em todos os surtos diagnosticados em 1978-2010 variou de 0,37 por cento a 20 por cento. Vinte e quatro casos ocorreram no outono, sete na primavera, 14 no verão e 16 no inverno. O diagnóstico foi realizado pela epidemiologia, sinais clínicos e lesões histológicas observadas. No estudo dos casos de raiva paralítica em bovinos ocorridos a partir de 2008, o diagnóstico foi confirmado pela técnica de imuno-histoquímica utilizando anticorpo policlonal anti-virus rábico. Em dois destes casos não foi observada meningoencefalite não-supurativa, porém a imuno-histoquímica demonstrou a presença do antígeno viral. Esta técnica é uma importante ferramenta para o diagnóstico de raiva, devendo ser utilizada em todos os casos suspeitos nos quais não se evidenciam lesões de encefalite.

A retrospective study of paralytic rabies in cattle in southern Rio Grande do Sul, Brazil, diagnosed from 1978 to 2007 by the Regional Diagnostic Laboratory (LRD) of the Veterinary School, Federal University of Pelotas (UFPel), with 77 outbreaks or isolated cases of paralytic rabies in cattle, is reported. A study of 11 outbreaks of rabies, observed from 2008 to 2010 in the same region, where 42 cattle aged 1-6 years died from a total of 686 at risk, with a clinical course of 4 to 14 days, was also made. The morbidity of all outbreaks diagnosed from 1978-2010 ranged from 0.37 percent to 20 percent; 24 cases occurred in autumn, 7 in spring, 14 in summer, and 16 in winter. The diagnosis was achieved by epidemiology, clinical signs and histological lesions. Immunohistochemistry using rabies virus polyclonal antibody was positive in all cases. In two cases non-suppurative meningoencephalitis was not observed, and the diagnosis was confirmed by immunohistochemistry. This technique is an important tool for the diagnosis of rabies and should be used in all suspected cases in which no evidence of encephalitis is observed.

Multimodal representation of optic flow in area PEc of macaque monkey.

The visual perception of self-motion is mainly provided by optic flow. Eyes usually scan the environment during locomotion, and the gaze is not always directed to the focus of expansion (FOE) of the flow field. Such eye movements change the retinal FOE position with respect to the fovea. Here, we assess if optic flow selective neurons in parietal area PEc are modulated by eye position. We recorded single neuron activity during radial optic flow stimulation in two monkeys, varying eye and retinal FOE positions. We found that the majority of PEc neurons are modulated by the FOE retinotopic position with different tuning for expansion and contraction. Although many neurons did not show any gaze field without visual stimulation, the eye position modulated optic flow responses in about half of the cells. These novel results suggest that PEc neurons integrate both visual and eye position signals, and allow us to hypothesize their role in guiding locomotion as a part of a cortical network involved in FOE representation during self-motion. Visual and eye position interaction in this area could be seen as a contribution to the building of the invariant space representation necessary to motor planning.

Neuronal responses in macaque area PEc to saccades and eye position.

Neurons in area PEc in the superior parietal cortex encode signals from different modalities, such as visual, extraretinal and somatosensory, probably combining them to encode spatial parameter of extrapersonal space to prepare body movements. This study reports the characterization of the functional properties of PEc non-visual neurons that showed saccade-related activity. We analyzed the pre- and post-saccadic firing activity in 189 neurons recorded in five hemispheres of three behaving monkeys. Spiking activity of PEc single neurons was recorded while the monkeys performed visually-guided saccades in a reaction time task. We found that 84% of neurons recorded from area PEc showed pre-saccadic activity with directional tuning. In 26% of neurons, we found inhibition of activity in the pre-saccadic period. The onset of this "pause" always started before the saccade and, in 51% of neurons, it was invariant among different gaze directions. The post-saccadic activity in these cells was either a phasic response with directional tuning (77%) and/or an eye position tuning (75%). The analysis of the preferred direction did not show hemispheric preference, however, for the majority of neurons, the angular difference in the preferred direction, in the pre- and post-saccadic period, was more than 60 degrees . By confirming, therefore, that PEc neurons carry information about eye position, these novel findings open new horizons on PEc function that, to date, is not well documented. The pre-saccadic activity may reflect an involvement in saccade control, whereas post-saccadic activity may indicate a role in informing on the new eye position. These novel results about saccade and eye position processing may imply a role of area PEc in gaze direction mechanisms and, possibly, in remapping visual space after eye movements.

Effect of early isolation on signal transfer in the entorhinal cortex-dentate-hippocampal system.

Deprivation of socio-sensory interactions during early life impairs brain function in adulthood. In previous investigations we showed that early isolation severely affects neuron development in several structures of the hippocampal region, including the entorhinal cortex. In the present study we investigated the effects of early isolation on signal processing along the entorhinal cortex-dentate-CA3-CA1 system, a major memory circuit of the hippocampal region. Male and female guinea-pigs were assigned at 6-7 days of age to either a social or an isolated environment. At 90-100 days of age the animals were anesthetized and field potentials were recorded from the entorhinal cortex-dentate-CA3-CA1 circuit, driven by dorsal psalterium commissural volleys. Analysis of the input-output function in the different structures showed that in isolated males there was a small reduction in the input-output function of the population excitatory postsynaptic potential and population spike evoked in layer II of the entorhinal cortex. No changes occurred in isolated females. In isolated males and females there was a reduction in the input-output function of the population excitatory postsynaptic potential and population spike evoked in the dentate gyrus, CA3 and CA1, but this effect was larger in males. In isolated males, but not in females, the population spike/population excitatory postsynaptic potential ratio was reduced in all investigated structures, indicating that in males the size of the discharged neuron population was reduced more than due to the decreased input. Results show that isolation reduces the synaptic function in the whole entorhinal cortex-dentate gyrus-CA3-CA1 system. While the entorhinal cortex was moderately impaired, the dentate-hippocampal system was more severely affected. The impairment in the signal transfer along the entorhinal cortex-dentate gyrus-CA3-CA1 system was heavier in males, confirming the larger susceptibility of this sex to early experience. This work provides evidence that malfunctioning of a major hippocampal network may underlie the learning deficits induced by impoverished surroundings during early life.

Mastocitoma cutâneo canino: estudo de 45 casos / Canine cutaneous mast cell tumor: study of 45 cases

Quarenta e cinco mastocitomas cutâneos caninos foram graduados histologicamente com o uso de hematoxilina-eosina. Foram empregados os métodos azul de toluidina e região organizadora nucleolar argirofílica (AgNOR) para, respectivamente, evidenciar os grânulos citoplasmáticos e avaliar o índice de proliferação celular. Diversas características histológicas foram observadas, como distribuição das células na pele, tamanho, forma, aspecto de citoplasma e núcleo, quantidade de estroma, presença de eosinófilos e alterações associadas. Com base nessas caracteríscas, 37,8 por cento dos mastocitomas foram classificados como grau I, 51,1 por cento como grau II e 11,1 por cento como grau III. A média geral de AgNOR nos mastocitomas foi de 1,9 (1,2 a 4,3) e as médias para os graus I, II e III foram, respectivamente, de 1,5, 1,85 e 3,25. A técnica de AgNOR mostrou ser de fácil execução, custo acessível e confiável como meio auxiliar para estimar um prognóstico mais objetivo para os mastocitomas.

Effects of early isolation on layer II neurons in the entorhinal cortex of the guinea pig.

Previous studies showed that early environmental conditions severely affect the morphology of the granule cells in the hippocampal dentate gyrus and pyramidal neurons in fields CA3 and CA1. The aim of the present study was to determine whether early isolation affects neuron morphology in layer II of the entorhinal cortex, from which the perforant path to the dentate gyrus and CA3 takes its origin. Male and female guinea pigs were assigned at 6-7 days of age to either a control (social) or an isolated environment where they remained for 80-90 days. The brains were Golgi-Cox stained and neurons were sampled from layer II of the entorhinal cortex. Morphometric analysis was carried out on star cells, the most abundant neuron population. Isolated males had star cells with less dendritic branches, a shorter dendritic length and a smaller dendritic spine density than control males. In contrast, isolated females had more dendritic branches than control females, though this difference was of small magnitude. While isolated males had star cells with a smaller soma than control males, isolated females had a soma larger than control females. In both environments sex differences were found in the star cell morphology. In the control environment males had more dendritic branches, a greater dendritic length, a larger soma but a smaller spine density than females. In the isolated environment males had less branches, a shorter dendritic length, a smaller spine density and a smaller soma than females. The results indicate that early isolation affects the structure of the star cells in the entorhinal cortex and that males and females react to isolation in an opposite manner. A similar sexually dimorphic response to early isolation was previously observed in the dentate gyrus and fields CA3 and CA1. The presence of widespread effects of isolation in the entorhinal cortex and numerous hippocampal structures suggests that the outcome of early isolation might be a change in learning and memory functions requiring the hippocampal region.

Equine monocytic Ehrlichiosis (Potomac horse fever) in horses in Uruguay and southern Brazil.

A disease named locally as churrío or churrido equino (i.e., equine scours) has occurred for at least 100 years in Uruguay and southern Brazil in farms along both shores of the Merín lake. This report describes cases of churrido equino and provides serologic, pathologic, and DNA-based evidence indicating that the disease is in fact equine monocytic ehrlichiosis (Potomac horse fever). Results of an epidemiological investigation conducted on an endemic farm are also presented. Clinical signs in 12 horses were fever, depression, diarrhea, dehydration, and sometimes colic and distal hind limb edema. Postmortem findings of 3 horses were of acute enterocolitis. Inclusion bodies containing ehrlichial organisms were found in the cytoplasm of macrophages of the large colon of 1 horse. Eleven of the 12 horses were serologically positive to Ehrlichia risticii (indirect fluorescent antibody assay) and, of 3 paired samples, 2 showed seroconversion. Ehrlichia risticii DNA was identified by a nested polymerase chain reaction in peripheral blood of an affected horse. A healthy horse inoculated with peripheral blood from an affected horse developed the disease and antibodies to E. risticii. The disease had a peak incidence in March (summer) and was statistically associated with a marshy ecosystem near the Merín lake, where large numbers of Pomacea spp. (Ampullariidae) snails were found. Incidence density was almost 8 times higher in nonnative horses than in native horses. It was concluded that the previous diarrheic disease of horses known in Uruguay and southern Brazil as churrido equino is equine monocytic ehrlichiosis.

Visual motion responses of neurons in the caudal area pe of macaque monkeys.

Area PE of macaques has traditionally been considered a somatosensory association cortex. Recent studies, however, suggest that neurons of this and neighboring areas are involved in the visual control of movement, especially arm movement. We investigated the neuronal sensitivity to local visual stimuli of this region by recording neuronal activity in two behaving macaque monkeys trained in a simple visual fixation task. Recordings were performed from the dorsal surface of the caudal pole of the superior parietal lobule (SPL). Classical receptive fields (RFs) were mapped by using conventional static or moving luminous figures. We found that many neurons in this area were selectively activated by moving visual stimuli. Cell responses were tuned to the movement direction. RFs were usually large; their mean surface covered some 30 x 30 degrees of the visual field. The fovea was often included into RF, in many cases it was along a RF side. The center of RFs was mainly located in the contralateral hemifield, although RFs having the center ipsilaterally sited were also found. No evident retinotopy was found. Visual neurons were especially concentrated in a region of the SPL likely corresponding to area PEc. These results suggest that the caudal part of area PE contains neuronal populations specifically signaling local visual motion, possibly encoding the direction of moving objects. These signals might well be suited for sensorimotor integration mechanisms aimed at motor acts.

Experimental intoxication by the mushroom Ramaria flavo-brunnescens in sheep.

Ramaria flavo-brunnescens collected in autumn from 1990 to 1994 was orally administered to 11 sheep. These animals were dosed with 100-430 g/kg bw administered over 3-13 d. Six sheep showed clinical signs and 4 of them died. The mininum toxic dose was of 150 g/kg bw. Clinical signs were anorexia, hyperthermia, dyspnea, polyuria, ataxy, muscle tremors and seizures. The eyes had hyperemia of the sclera and, in some cases, hemorrhages of the anterior chamber or corneal opacity. Sheep dosed with higher doses had ulcerations of the tongue and necrotic lesions in the hooves. The main histologic lesions of the feet and tongue were miopachynsis and endotelial degeneration followed by degeneration, necrosis and ulceration of the epithelium. Hemorrhages of the anterior chamber, and severe congestion and hemorrhages of the iris, ciliary body and process were observed in the eyes. Congestion and perivascular hemorrhages occurred in the central nervous system. The similarity of clinical signs and pathologic lesions induced by R flavo-brunnescens and those caused by ergotism in cattle and sheep suggests the presence ofa vasoactive constrictive substance in the mushroom. Fresh R flavo-brunnescens dosed in autumn 1993 was not toxic at doses of 200-400 g/kg demonstrating variations in the toxicity of the mushroom from year to year.