Effects of intravenous injection of Clostridium perfringens type D epsilon toxin in calves

In cattle, a neurological lesion similar to that produced in sheep and goats by Clostridium perfringens type D enterotoxaemia has been reported. However, no causal relationship has been established between this disease and the lesion in cattle. The effects of single and multiple intravenous injections of epsilon toxin in three calves aged 6 months were studied. A further calf was inoculated intravenously with saline solution and used as a control. Epsilon toxin invariably produced neurological signs within 2-60 min of the end of the injection process. Clinical signs consisted of loss of consciousness, recumbency, convulsions, paddling, opisthotonus, hyperaesthesia and dyspnoea. Gross changes consisted of severe acute pulmonary oedema, which was particularly marked in the interlobular septa. The histological lesions consisted of intra-alveolar and interstitial oedema of the lung and variable degrees of perivascular proteinaceous oedema in the internal capsule, thalamus and cerebellar white matter. No clinical or post-mortem changes were observed in the control calf. These results show that calves are susceptible to the intravenous injection of epsilon toxin, and that they can show at least some of the histological lesions produced in sheep and goats by this toxin.

Reversible magnetic resonance imaging abnormalities in dogs following seizures

Reversible magnetic resonance (MR) imaging lesions have been described in humans following seizures. This condition has not yet been reported in animals. This paper describes reversible abnormalities identified in 3 dogs using MR imaging that was performed initially within 14 days of the last seizure and follow-up imaging that was performed after 10 to 16 weeks of anticonvulsant therapy. All three dogs had lesions in the piriform/temporal lobes, characterized by varying degrees of hyperintensity on T2-weighted images and hypointensity on T1-weighted images. In one dog, contrast enhancement was evident. On reevaluation, partial resolution occurred in all 3 dogs. In a fourth animal with an olfactory meningioma, similar appearing lesions in the temporal cortex and right and left piriform lobes were identified after seizure activity. A surgical biopsy of the temporal cortex and hippocampus was performed and edema, neovascularization, reactive astrocytosis, and acute neuronal necrosis were evident. These histologic findings are similar to those reported in humans with seizures. Recognizing the potential occurrence of reversible abnormalities in MR images is important in developing a diagnostic and therapeutic plan in canine patients with seizures. Repeat imaging after seizure control may help differentiate between seizure-induced changes and primary multifocal parenchymal abnormalities.

Histopathological changes in the brain of mice given Clostridium perfringens type D epsilon toxin

The distribution, severity and frequency of brain lesions produced in mice by the administration of Clostridium perfringens Type D epsilon toxin were examined by light microscopy. The granular layer of the cerebellum was the area most frequently affected in mice given single doses of toxin. Sequential changes in brain morphology were examined from 1 h to 7 days after injection of toxin. Lesions progressed from an initial vasogenic oedema to malacic foci which commonly were focal and bilaterally symmetrical, with a predilection for white matter. The topographical distribution of these malacic areas is discussed.

Edema disease-like brain lesions in gnotobiotic piglets infected with Escherichia coli serotype O157:H7

Gnotobiotic piglets inoculated with Escherichia coli serotype O157:H7 strains that produced Shiga-like toxin II developed brain lesions similar to those observed in edema disease of swine, including arteriolar necrosis and malacia. Loss of ability to produce Shiga-like toxin II resulted in loss of ability to cause brain lesions.

Cerebral physiological and biochemical changes during vasogenic brain oedema induced by intrathecal injection of bacterial lipopolysaccharides in piglets

BACKGROUND

The objective of the study was to evaluate biochemical and physiological changes in an experimental model of vasogenic brain oedema utilising techniques also used in routine neurointensive care.

METHOD

32 piglets were randomised to control or experimental group. The latter received an intrathecal injection of lipopolysaccharide (LPS) from E. coli (LPS group). Intracranial pressure (ICP)and mean arterial pressure (MAP) were measured continuously. Intracerebral microdialysis was used for analysing interstitial levels of glucose, pyruvate, lactate, glutamate, glycerol and urea every 30 min. Repeated calculations of mean hemispheric CBF were performed utilising an extracranial scintillation detector and Intra-carotid injection of (133)Xe. Cerebral specific gravity was measured and the brains were fixed for histological examinations.

FINDINGS

After LPS injection ICP increased reaching a plateau phase after 4-7 hours and CBF increased by 46%. Histological examination showed inflammation with pronounced extravasation of granulocytes. A significant decrease in brain specific gravity (p =0.022) was obtained. LPS caused a significant decrease in cerebral interstitial concentration of glucose (p = 0.0035), and significant increases in lactate concentration (p = 0.002) and lactate/pyruvate ratio (p = 0.0017). A small but significant increase in glutamate was obtained (p = 0.0219). Glycerol did not change significantly.

INTERPRETATION

Intrathecal LPS caused an inflammatory reaction with extravasation of granulocytes, increased blood-brain barrier permeability and cerebral oedema. Biochemical analyses indicate increased glycolysis but no signs of cell membrane degradation.

Bovine citrullinaemia: a clinical, pathological, biochemical and genetic study

Calves affected with citrullinaemia are clinically normal immediately after birth. In the majority of calves the clinical course of the disease was similar. Within 24 hours of birth they become depressed; then within 3 to 4 days were observed to wander aimlessly or stand with their head pressed against a wall or fence. By day 4 to 5 they become recumbent, developed convulsions, followed by collapse and death. Oedema of the cerebral cortex is a consistent histological lesion. Citrulline concentration in blood, cerebrospinal fluid, eye fluid and cerebral tissue is greatly elevated. Information gathered from pedigrees of affected calves indicate that the defect is widely disseminated throughout the Australian Friesian population.

Fast in vivo water quantification in rat brain oedema based on T(1) measurement at high magnetic field

BACKGROUND

In vivo water content determination based on magnetic resonance (MR) method is of importance in clinical practice as well as in animal studies to follow up the treatment given in order to reduce brain oedema. The methods proposed in the literature so far are largely time consuming. The aim of this study was to find a fast in vivo water quantification method having real advantage for patients suffering from critical conditions.

METHOD

Cold injury was applied to provoke brain oedema in fourteen rats. T(1) values of both the oedematous area and the contralateral normal cortex were determined by two independent methods 24 hours after the cold impact. First, from a series of images recorded by inversion recovery spin echo (IRSE) sequence and then by progressive saturation experiment performed by localised MR spectroscopy using stimulated echo acquisition mode (STEAM). To reduce the acquisition time, a two-element repetition time array was optimised for the STEAM experiment, whereas four inversion times were used for T(1) mapping. Both methods were validated against gel phantoms with known T(1) values. After the MR measurements the animals were sacrificed and the water contents of the regions of interest were determined by gravimetric wet-dry method.

FINDINGS

The reciprocals of the in vivo measured T(1) values were correlated with the reciprocals of the brain water contents. STEAM experiment showed stronger correlation (r=0.96) than IRSE (r=0.93). In addition, STEAM provided more accurate T(1) values in the phantom study. Determination of brain water content based on T1 measurement does work also at high magnetic field. Determination of brain water content by Magnetic Resonance Spectroscopy is feasible within 2 minutes.

INTERPRETATION

Using the presented fast method, water content can be determined within a couple of minutes in animal experiments as well as in the daily clinical practice.

Encephalolopathies in cattle in Tasmania

Five central nervous diseases are described and their relationships to previously recorded conditions are discussed. The conditions are congenital inclusion-body encephalopathy probably caused by a paramyxovirus infection, idiopathic neuraxial oedema of a newborn calf, focal symmetrical encephalomalacia of a young calf, yacca (Xanthorrhoea spp) poisoning of adult cattle leading to spinal demyelination, and focal demyelination and neuropathy in an adult cow.

Computed tomography and magnetic resonance findings in two dogs and a cat with intracranial lesions

Two dogs and a cat with intracranial lesions were evaluated by both computed tomography (CT) and magnetic resonance (MR) imaging. In a dog with vestibular syndrome, better quality images of the medulla oblongata surrounded by thick bones were obtained by MR than by CT, on which the appearance of artifacts impeded the clear image of the area. In a dog with multiple brain metastases of lymphoma, contrast CT delineated lesions more clearly than MR, which was performed one week after CT. During that week dexamethasone which might affect the clarity of MR images of the lesion was administered to reduce brain edema. In a cat with meningeal syndrome of lymphocytic leukemia, only contrast MR imaging identified the width and site of the lesion. These results indicate that it is necessary to select either one of these imaging methods according to the type and site of lesions that are suspected in a particular case.

Spontaneous cleft palate in a newborn gorilla (Gorilla gorilla gorilla)

OBJECTIVE

We report the first case of cleft palate in a newborn male gorilla (Gorilla gorilla gorilla).

CASE HISTORY AND RESULTS

The full-term infant was born to clinically healthy, wild-caught parents and survived 5 days. Autopsy disclosed a unilateral cleft palate, moderate scalp hemorrhage (birth versus postnatal trauma), cerebral edema, and a sterile fibrin vegetation in the heart. The palate was also shorter and narrower than expected, and the biorbital breadth was reduced; otherwise, growth and development appeared normal. Standard cranial and intraoral radiographs and three-dimensional reconstructions of computerized tomographic (CT) scans provided thorough and noninvasive methods of studying the craniofacial complex and extracranial skeleton. By this technique, major findings were: intact premaxilla, interpremaxillary, and premaxillary/maxillary sutures; intramaxillary cleft with ipsilateral choanal atresia; mildly asymmetric inferior turbinates; and normal nasal septum and vomer.

CONCLUSIONS

Except for choanal atresia, cleft palate was not associated with other major craniofacial or extracranial anomalies in this case. Choanal atresia has been observed at times with cleft palate, but to our knowledge, the association has not been reported in nonhuman primates. Cleft palate, with or without cleft lip, has been recognized in a variety of nonhuman primates, including the lemur, marmoset, tamarin, squirrel monkey, and macaque. Some occurrences are spontaneous, while others are syndromic and/or arise from genetic or teratogenic influences. Each mode of presentation is poorly understood in nonhuman primates, but in this case, the absence of relevant environmental or parental history suggests that the occurrence was spontaneous. Anatomic studies of nonhuman primates are particularly valuable when they involve endangered species and will hopefully increase our understanding of the pathogenesis and etiology of congenital disorders, as well as other relationships between nonhuman primates and humans.

Case report: neuropathology of methyl bromide intoxication

The neuropathological findings in a man and his dog both of whom died after acute exposure to methyl bromide are presented. The dog had cerebral oedema, most marked in the depths of cortical sulci. The man survived 30 days after the initial illness and his brain contained well-defined symmetrical lesions in the mammillary bodies and inferior colliculi. He also had a peripheral neuropathy and lymphocytic thyroiditis. The pathology in the central nervous system has features resembling Wernicke's encephalopathology; the mechanism by which methyl bromide may produce such lesions is discussed.

Evaluation of autofluorescence as an aid to diagnosis of cerebrocortical necrosis

A series of brains from sheep, cattle, goats and pigs was examined histopathologically and illuminated by ultraviolet light to test the specificity of autofluorescence in the diagnosis of cerebrocortical necrosis. Fluorescence was seen in only four cases of porcine encephalopathy. In the ruminant brains it occurred in seven out of eight cases of cerebral oedema of lambs; otherwise it was confined to cases of cerebrocortical necrosis, although a few false negative cases were encountered. Ovine cerebral oedema is a disease of unweaned lambs which is unlikely to be confused with cerebrocortical necrosis. Thus bright cerebrocortical autofluorescence in a naturally occurring disease of cattle, sheep and goats is a likely indicator of cerebrocortical necrosis; however, a small proportion of cases will escape detection by this method.

Hereditary neuraxial edema in Polled Hereford calves

Two newborn Polled Hereford calves with hereditary neuraxial edema were available for clinical and pathological examination. The affected animals showed extensor spasms and were unable to rise. Pathologic lesions were microscopic and consisted of widespread vacuolation of the neuraxis, chiefly in white matter and less markedly in grey matter. The lesions were most severe in the brain stem and cerebellar white matter. Examination of the breeding record indicated sire-daughters matings and thus a probably autosomal recessive mode of inheritance.