Primary hyperlipidemia with associated ischemic strokes in a West Highland white terrier dog.

A 3-year-old spayed female, West Highland white terrier dog was evaluated because of a 4-month history of recurrent brain clinical signs. Magnetic resonance imaging (MRI) revealed multifocal brain lesions consistent with ischemic injuries. Blood analysis was unremarkable aside from severe hypertriglyceridemia and hypercholesterolemia with no underlying cause, suggesting primary hyperlipidemia. The patient was treated for hyperlipidemia and started on a low-fat diet and omega-3 supplementation. Clinical signs resolved over the following 12 months along with improvement in lipidemia. This represents the first reported case of MRI findings suggestive of multiple cerebrovascular injuries associated with primary hyperlipidemia in a dog, and the first primary hyperlipidemia reported in a West Highland white terrier dog.

Hyperlipidémie primaire associée à des accidents vasculaires cérébraux ischémiques chez un chien terrier West Highland white. Une femelle stérilisée West Highland white âgée de 3 ans fut évaluée à cause d'une histoire de signes cliniques cérébraux récurrents d'une durée de 4 mois. Une imagerie par résonnance magnétique (RMI) révéla des lésions cérébrales multifocales compatibles avec des blessures ischémiques. Une analyse sanguine s'avéra peu concluante sauf pour une hypertriglycéridémie et une hypercholestérolémie sévère sans cause sous-jacente, suggérant une hyperlipidémie primaire. Le patient fut traité pour l'hyperlipidémie et débuta une diète faible en gras et une supplémentation en oméga-3. Les signes cliniques se sont résolus dans les 12 mois suivants avec une amélioration de la lipidémie. Ceci représente le premier cas rapporté de trouvailles par MRI suggestives de lésions cérébro-vasculaires multiples associées avec une hyperlipidémie primaire chez un chien, et le premier cas d'hyperlipidémie primaire rapporté chez un terrier West Highland white.(Traduit par Dr Serge Messier).

Buyang Huanwu Decoction Attenuates Infiltration of Natural Killer Cells and Protects Against Ischemic Brain Injury.

BACKGROUND/AIMS: Natural killer (NK) cells are among the first immune cells that respond to an ischemic insult in human brains. The infiltrated NK cells damage blood-brain barrier (BBB) and exacerbate brain infarction. Buyang Huanwu Decoction (BHD), a classic Chinese traditional herbal prescription, has long been used for the treatment of ischemic stroke. The present study investigated whether BHD can prevent brain infiltration of NK cells, attenuate BBB disruption and improve ischemic outcomes. METHODS: Transient focal cerebral ischemia was induced in rats by a 60-minute middle cerebral artery occlusion, and BHD was orally administrated at the onset of reperfusion, 12 hours later, then twice daily. Assessed parameters on Day 3 after ischemia were: neurological and motor functional deficits through neurological deficit score and rotarod test, respectively; brain infarction through TTC staining; BBB integrity through Evans blue extravasation; matrix metalloproteinase-2/9 activities through gelatin zymography; tight junction protein, nuclear factor-kB (NF-kB) p65 and phospho-p65 levels through Western blotting; NK cell brain infiltration and CXCR3 levels on NK cells through flow cytometry; interferon-γ production through ELISA; CXCL10 mRNA levels through real-time PCR; CXCL10 expression and p65 nuclear translocation through immunofluorescence staining. RESULTS: BHD markedly reduced brain infarction, improved rotarod performance, and attenuated BBB breakdown. Concurrently, BHD attenuated the upregulation of matrix metalloproteinase-2/9 activities and the degradation of tight junction proteins in the ischemic brain. Infiltration of NK cells was observed in the ischemic hemisphere, and this infiltration was blunted by treatment with BHD. BHD suppressed brain ischemia-induced interferon-γ and chemokine CXCL10 production. Furthermore, BHD significantly reduced the expression of CXCR3 on brain-infiltrated NK cells. Strikingly, BHD did not affect NK cell levels or its CXCR3 expression in the spleen or peripheral blood after brain ischemia. The nuclear translocation of NF-kB p65 and phospho-p65 in the ischemic brain was inhibited by BHD. CONCLUSION: Our findings suggest that BHD prevents brain infiltration of NK cells, preserves BBB integrity and eventually improves ischemic outcomes. The inhibitory effects of BHD on NK cell brain invasion may involve its ability of suppressing NF-kB-associated CXCL10-CXCR3-mediated chemotaxis. Notably, BHD only suppresses NK cells and their CXCR3 expression in the ischemic brain, but not those in periphery.

Oxygen-glucose deprivation-induced glial cell reactivity in the rat primary neuron-glia co-culture.

It has been demonstrated that in vivo brain ischemia induces activation and proliferation of astrocytes and microglia. However, the mechanism underlying the ischemia-induced activation and proliferation of these cells remains to be unclear. Oxygen-glucose deprivation (OGD), an in vitro ischemia mimic, has been extensively used to analyze the hypoxia response of various cell types. This study examined the OGD-induced changes in the expression level of astrocytes and microglia marker proteins and immunoreactivity for Ki-67, a marker protein for cell proliferation, using rat primary hippocampal neuron-glia co-culture (NGC) cells. Furthermore, OGD-induced changes in the expression of M1/M2 microglia phenotype-related genes were also examined. MTT assay indicated that 120 min of OGD decreased cell viability, and immunocytochemistry indicated that 120 min of OGD abolished most microtubule-associated protein 2 (MAP2)-immunopositive neurons. In contrast, glial fibrillary acidic protein (GFAP)-immunopositive astrocytes and ionized calcium-binding adapter protein-1 (Iba-1)-immunopositive microglia, and 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNPase)-immunopositive oligodendrocytes survived OGD. Western blot assays and double-immunofluorescent staining indicated that OGD increased the GFAP expression level and the Ki-67-immunopositive/GFAP-immunopositive cells' ratio. Real-time PCR analysis showed that OGD altered M1 microglia phenotype-related genes. Specifically, OGD decreased the expression level of CD32 and interleukin-1ß (IL-1ß) genes and increased that of the inducible nitric oxide synthase (iNOS) gene. Therefore, applying OGD to NGC cells could serve as a useful in vitro tool to elucidate the molecular mechanisms underlying brain ischemia-induced changes in GFAP expression, astrocyte proliferation, and M1 microglia phenotype-related gene expression.

Protective effects of anise in prevention of cerebral ischemia reperfusion injury in rats.

The aim of this study is to determine the protective efficacy of anise in cerebral ischemia and reperfusion injury in rats. In this study, 28 Wistar Albino rats, weighing 250-300 grams (g), were used. Four groups were formed with 7 rats in each group. Group 1 (n=7): Control group, Group 2 (n=7): Anise group, 5 mL/kg/day of anise aqueous extract prepared according to Gamberini's protocol was given orally by gavage for 30 days. Group 3 (n=7): Cerebral ischemia reperfusion (CIR) group, at the beginning of the experiment, 30 minutes of cerebral ischemia and 1 hour of reperfusion were induced and the animals were sacrificed by exanguination. Group 4 (n=7): Anise+ CIR group, After administering 30 days of anise's aqueous extract, CIR was induced and the study was terminated. TOS values of the Anise+ CIR group was significantly lower than that of the CIR group (p<0.05). Il-6 and TNF-α values of the CIR group were significantly higher than the Anise+ CIR group (p<0,05). Our study revealed that anise ameliorates oxidative damage and inflammation due to cerebral ischemia/reperfusion, by reducing the levels of inflammatory cytokines (TNF-α, Il-6).

Identification of changed proteins by retinoic acid in cerebral ischemic damage: a proteomic study.

Ischemic stroke is a severe neurodegenerative disease with a high mortality rate. Retinoic acid is a representative metabolite of vitamin A. It has many beneficial effects including anti-inflammatory, anti-apoptotic, and neuroprotective effects. The purpose of this study is to identify specific proteins that are regulated by retinoic acid in ischemic stroke. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia. Retinoic acid (5 mg/kg) or vehicle was injected intraperitoneally into male rats for four days prior to MCAO operation. Neurobehavioral tests were performed 24 hr after MCAO and the cerebral cortex was collected for proteomic study. Retinoic acid alleviates neurobehavioral deficits and histopathological changes caused by MCAO. Furthermore, we identified various proteins that were altered by retinoic acid in MCAO damage. Among these identified proteins, adenosylhomocysteinase, isocitrate dehydrogenase [NAD+] subunit α, glycerol-3-phosphate dehydrogenase, Rab GDP dissociation inhibitor ß, and apolipoprotein A1 were down-regulated in MCAO animals with vehicle treatment, whereas retinoic acid treatment alleviated these reductions. However, heat shock protein 60 was up-regulated in MCAO animals with vehicle, while retinoic acid treatment attenuated this increase. The changes in these expressions were confirmed by reverse transcription-PCR. These proteins regulate cell metabolism and mediate stress responses. Our results demonstrated that retinoic acid attenuates the neuronal damage by MCAO and regulates the various protein expressions that are involved in the survival of cells. Thus, we can suggest that retinoic acid exerts neuroprotective effects on focal cerebral ischemia by modulation of specific proteins.

Brain magnetic resonance imaging and histopathology findings in a dog with global brain ischaemia following cardiopulmonary arrest.

BACKGROUND: Global brain ischaemia following cardiopulmonary arrest is uncommonly reported in veterinary medicine yet neurologic injury after arrest is a known morbidity. CASE REPORT: An 18-week-old male entire Cavalier King Charles Spaniel-Poodle was referred following 3 days of neurologic abnormalities after cardiopulmonary arrest. After resuscitation, the animal had decerebrate rigidity, a stuporous mentation and intermittent episodes of vocalisation and apnoea. A brain magnetic resonance imaging (MRI) was undertaken 4 days after cardiopulmonary arrest, with standard sequences (T1-weighted, T2-weighted and fluid-attenuated inversion recovery) as well as diffusion-weighted imaging to better discern ischaemic injury and cytotoxic oedema for prognostic reasons. MRI findings were consistent with global brain ischaemia affecting the hippocampus, cerebellum and substantia nigra, the latter two not previously identified in canine cases of global brain ischaemia. The patient was euthanased on day eight post-cardiopulmonary arrest due to a lack of neurological improvement and developing sepsis as a complication. Ante-mortem identification of affected areas of the brain was confirmed on histological examination, with evidence of ischaemic injury seen in the cerebrum, hippocampus, cerebellum, basal nuclei and thalamus. CONCLUSION: This report describes ante-mortem MRI and postmortem findings in a dog with global brain ischaemia following cardiopulmonary arrest. A multimodal approach to neuroprognostication in patients recovering from cardiopulmonary arrest is recommended.

Chlorogenic acid alleviates the reduction of Akt and Bad phosphorylation and of phospho-Bad and 14-3-3 binding in an animal model of stroke.

BACKGROUND: Stroke is caused by disruption of blood supply and results in permanent disabilities as well as death. Chlorogenic acid is a phenolic compound found in various fruits and coffee and exerts antioxidant, anti-inflammatory, and anti-apoptotic effects. OBJECTIVES: The purpose of this study was to investigate whether chlorogenic acid regulates the PI3K-Akt-Bad signaling pathway in middle cerebral artery occlusion (MCAO)-induced damage. METHODS: Chlorogenic acid (30 mg/kg) or vehicle was administered peritoneally to adult male rats 2 h after MCAO surgery, and animals were sacrificed 24 h after MCAO surgery. Neurobehavioral tests were performed, and brain tissues were isolated. The cerebral cortex was collected for Western blot and immunoprecipitation analyses. RESULTS: MCAO damage caused severe neurobehavioral disorders and chlorogenic acid improved the neurological disorders. Chlorogenic acid alleviated the MCAO-induced histopathological changes and decreased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. Furthermore, MCAO-induced damage reduced the expression of phospho-PDK1, phospho-Akt, and phospho-Bad, which was alleviated with administration of chlorogenic acid. The interaction between phospho-Bad and 14-3-3 levels was reduced in MCAO animals, which was attenuated by chlorogenic acid treatment. In addition, chlorogenic acid alleviated the increase of cytochrome c and caspase-3 expression caused by MCAO damage. CONCLUSIONS: The results of the present study showed that chlorogenic acid activates phospho-Akt and phospho-Bad and promotes the interaction between phospho-Bad and 14-3-3 during MCAO damage. In conclusion, chlorogenic acid exerts neuroprotective effects by activating the Akt-Bad signaling pathway and maintaining the interaction between phospho-Bad and 14-3-3 in ischemic stroke model.

Feline cerebrovascular disease: clinical and histopathologic findings in 16 cats.

Sixteen cats with cerebrovascular disease confirmed via histology to be of nontraumatic and nonneoplastic origins are described. In addition, the anatomy of the arterial supply of the cat's brain is reviewed. It is suggested that this unique arterial design may influence the incidence of cerebrovascular accidents in this species. Of the 16 cats reviewed, seven cats had ischemic infarctions, five had hemorrhagic infarctions, and four were diagnosed with intracranial hemorrhage. The median age was 8 yr and 9.5 yr in cats with infarctions and intracranial hemorrhages, respectively. Clinical signs were severe, acute, consistent with the localization of the cerebrovascular lesion, and influenced by underlying pathology. Four cats with infarction showed lateralized neurologic signs. Four cats with infarctions were diagnosed with pulmonary disease antemortem and three cats had hyperthyroidism. Cerebrospinal fluid analysis and computed tomography scans were available in two cats. None of the infarctions were grossly visible. All cats with hemorrhagic infarcts had severe liver pathology and nephritis was identified in four cats. Hypoxia was a feature in four cats and one cat suffered cardiac failure. In conclusion, the clinical picture is influenced by the type of cerebrovascular disease, the localization of the intracranial lesions, and any underlying pathology.

Quantitative Proteomic Analysis of Plasma after Remote Ischemic Conditioning in a Rhesus Monkey Ischemic Stroke Model.

BACKGROUND: Animal and clinical studies have shown that remote ischemic conditioning (RIC) has protective effects for cerebral vascular diseases, with induced humoral factor changes in the peripheral blood. However, many findings are heterogeneous, perhaps due to differences in the RIC intervention schemes, enrolled populations, and sample times. This study aimed to examine the RIC-induced changes in the plasma proteome using rhesus monkey models of strokes. METHODS: Two adult rhesus monkeys with autologous blood clot-induced middle cerebral artery (MCA) occlusion underwent RIC interventions twice a week for five consecutive weeks. Each RIC treatment included five cycles of five minutes of ischemia alternating with five minutes of reperfusion of the forearm. The blood samples were taken from the median cubital vein of the monkeys at baseline and immediately after each week's RIC stimulus. The plasma samples were isolated for a proteomic analysis using mass spectrometry (MS). RESULTS: Several proteins related to lipid metabolism (Apolipoprotein A-II and Apolipoprotein C-II), coagulation (Fibrinogen alpha chain and serpin), immunoinflammatory responses (complement C3 and C1), and endovascular hemostasis (basement membrane-specific heparan sulfate proteoglycan) were significantly modulated after the RIC intervention. Many of these induced changes, such as in the lipid metabolism regulation and anticoagulation responses, starting as early as two weeks following the RIC intervention. The complementary activation and protection of the endovascular cells occurred more than three weeks postintervention. CONCLUSIONS: Multiple protective effects were induced by RIC and involved lipid metabolism regulation (anti-atherogenesis), anticoagulation (antithrombosis), complement activation, and endovascular homeostasis (anti-inflammation). In conclusion, this study indicates that RIC results in significant modulations of the plasma proteome. It also provides ideas for future research and screening targets.

Preliminary investigation of serum cardiac troponin I in dogs with acute ischaemic stroke.

OBJECTIVES: To describe the incidence of elevated serum cardiac troponin I in dogs with acute ischaemic strokes, to evaluate its prognostic value in these patients and characterise a possible relationship between cardiac troponin I elevation in dogs with ischaemic strokes and underlying cardiac dysfunction. MATERIALS AND METHODS: Prospective study of 18 dogs with acute ischaemic stroke diagnosed by MRI of the brain. Serum cardiac troponin I concentration, trans-thoracic echocardiography and six-lead electrocardiography were performed and findings were compared between dogs with good and poor outcome. RESULTS: Serum cardiac troponin I was increased in 17 dogs (median 0.95 ng/mL; range 0.146 to 153). Focal hyperechoic regions of myocardium were visible in two dogs using trans-thoracic echocardiography and presumed to represent acute infarcts. A significant association was found between cardiac troponin I and creatinine concentrations. No difference in cardiac troponin I concentrations was detected between dogs that experienced good and poor outcomes. Clinically important cardiac dysfunction was identified in two dogs. CLINICAL SIGNIFICANCE: Cardiac troponin I is commonly elevated in patients diagnosed with acute ischaemic stroke but, in this small study population, did not have prognostic value. Larger studies (recruiting a study population of 98 dogs for a power of 0.8 and a 0.05 alpha/critical value) would aid in further investigation of these preliminary results.

Diagnosis and long-term outcome in dogs with acute onset intracranial signs.

OBJECTIVES: To investigate dogs with acute onset of intracranial signs suspected of stroke by primary veterinary clinicians, and establish possible differential diagnoses and long-term outcome. In addition, serum C-reactive protein and plasma cytokines were investigated as potential biomarkers of disease. MATERIALS AND METHODS: All cases were evaluated by neurologic examination, routine haematology and biochemistry and measurement of serum C-reactive protein, plasma cytokine concentrations (interleukin-2, -6, -8, -10, tumour necrosis factor) and low-field MRI. RESULTS: Primary veterinarians contacted the investigators with 85 suspected stroke cases. Only 20 met the inclusion criteria. Of these, two were diagnosed with ischaemic stroke. Other causes were idiopathic vestibular syndrome (n=6), brain tumour (n=5) and inflammatory brain disease (n=2); in five cases a precise diagnosis could not be determined. Median survival times were: brain tumour, 3 days, idiopathic vestibular syndrome, 315 days, ischaemic stroke, 365 days and inflammatory central nervous system (CNS) disease, 468 days. The median plasma concentrations of interleukin-2, -6, -8, -10 or tumour necrosis factor were not significantly increased in any of the diagnosis groups compared to healthy controls. Serum C-reactive protein was higher in dogs with brain tumours and inflammatory brain disease but not above the upper bound of the reference interval. CLINICAL SIGNIFICANCE: Dogs that present with acute onset intracranial disease may have ischaemic stroke but are more likely to have other causes. Many dogs with such acute onset of neurological dysfunction (brain tumours excluded) may recover within a couple of weeks despite their initial severe clinical appearance.

Cerebral Computed Tomography Scan Demonstrating Ischemic Stroke in a Filly After Intravenous Antibiotic Administration.

Performing a brain computerized tomography scan (CT scan) on a foal requires specific equipment and anesthesia for large animals. However, the information obtained may demonstrate lesions responsible for the neurological deficits. Especially, CT scan findings may help to understand a mechanism of cerebral ischemia. Indeed, categories of cerebral ischemia are divided in three types: territorial infarctions (downstream of the territory of an artery), watershed infarctions (slow-flow at the junction of two arterial territories), and lacunar infarctions (small-vessel occlusions). Hypersensitivity reactions and type I anaphylactic IgE antibody reactions are severe potential adverse effects of sulfonamide administration, which occur in about three percent of cases. In horses, anaphylaxis is often clinically expressed as hypotension and collapse. Cardiovascular collapse may lead to multiorgan slow-flow leading to infarction with multiorgan failure and death. We report the case of a filly that suffered a presumed watershed cerebral infarction after antibiotic injection, indicated on a brain CT scan. This was attributed to a cerebral slow-flow during cardiovascular collapse, at the posterior junction of the right cerebral arteries. No abnormalities were initially identified on the CT scan; however, a review of the imaging by a radiologist specialized in cerebrovascular diseases detected a limited right occipital cortico-subcortical lesion in the visual cortex, interpreted as an ischemic scar in the watershed area related to hemodynamic infarction. This case highlights that detection of brain lesions by CT scan might require specialized knowledge and careful reading for interpretation particularly in the case of limited lesions.

Convergence-Retraction Nystagmus in a Dog With Presumptive Ischemic Encephalopathy Following Acute Cervicothoracic Myelopathy.

A 6.5-year-old male neutered Trailhound was admitted for hyperacute, nonprogressive, left-sided hemiparesis. Physical and neurologic examination revealed nonpainful, left-sided poorly ambulatory hemiparesis, decreased left-sided postural reactions and thoracic limbs hyporeflexia. Neuroanatomic localisation was consistent with a left-sided C6-T2 myelopathy. Haematology and biochemistry revealed nonspecific abnormalities. Magnetic resonance imaging of the neck revealed a focal intramedullary lesion at the level of C6-C7 vertebrae compatible with acute hydrated noncompressive nucleus pulposus extrusion or ischemic myelopathy. During the second day of hospitalization, the dog developed convergence-retraction nystagmus, up-gaze palsy and eyelid retraction (Collier's sign) compatible with dorsal midbrain syndrome. Magnetic resonance imaging of the brain revealed a focal lesion compatible with dorsal midbrain ischemic infarct. Further clinicopathologic testing, thoracic and abdominal imaging were unremarkable. Ischemic encephalopathy of unknown etiology was additionally diagnosed. Physiotherapy was performed therapeutically. At 1-year follow-up the dog was normal. This is an unusual report of a dog with myelopathy followed by ischemic encephalopathy with manifestation of convergence-retraction nystagmus in the absence of vestibular signs. This saccadic intrusion is a characteristic clinical manifestation of a dorsal midbrain syndrome localization. The importance of a complete differential diagnoses list formation in a dog with ischemic encephalopathy which leads to a thorough diagnostic investigation plan is highlighted. Moreover, this report contributes to the enrichment of the clinical reasoning veterinary literature on convergence-retraction nystagmus. To the authors' knowledge, this is the second case report (fourth dog) to describe convergence-retraction nystagmus in dogs as a manifestation of dorsal midbrain syndrome.

Ischaemic and haemorrhagic stroke in the dog.

Cerebrovascular disease results from any pathological process of the blood vessels supplying the brain. Stroke, characterised by its abrupt onset, is the third leading cause of death in humans. This rare condition in dogs is increasingly being recognised with the advent of advanced diagnostic imaging. Magnetic resonance imaging (MRI) is the first choice diagnostic tool for stroke, particularly using diffusion-weighted images and magnetic resonance angiography for ischaemic stroke and gradient echo sequences for haemorrhagic stroke. An underlying cause is not always identified in either humans or dogs. Underlying conditions that may be associated with canine stroke include hypothyroidism, neoplasia, sepsis, hypertension, parasites, vascular malformation and coagulopathy. Treatment is mainly supportive and recovery often occurs within a few weeks. The prognosis is usually good if no underlying disease is found.

Neuropathological findings suggestive for a stroke in an alpaca (Vicugna pacos).

BACKGROUND: This case report describes a focal brain lesion in an alpaca (Vicugna pacos). Although this is a restricted study based on a single animal, neuropathological features are reported that are most likely attributed to a vascular event with either ischemic or hemorrhagic pathology. Concerning translational issues, these findings extend neurovascular unit concept to the alpacas' brain and qualify a larger panel of stroke tissue markers for further exploration of ischemic or hemorrhagic consequences beyond the usually used small animal models in stroke research. CASE PRESENTATION: A brain lesion indicative of a stroke was diagnosed in a 3-year-old female alpaca as an incidental finding during a post mortem examination. The rostral portion of the right frontal lobe contained a 1.0 × 1.5 × 1.7 cm lesion that extended immediately to the overlying leptomeninges. Microscopically, it was composed of liquefactive necrosis with cholesterol crystal deposition and associated granulomatous inflammation as well as vascularized fibrous connective tissue rimmed by proliferated astrocytes. Multiple fluorescence labeling of the affected brain regions revealed strong microgliosis as shown by immunostaining of the ionized calcium binding adapter molecule 1 and astrogliosis as demonstrated by enhanced immunoreactivity for glial fibrillary acidic protein. In parallel, a drastic neuronal loss was detected by considerably diminished immunolabeling of neuronal nuclei. Concomitantly, up-regulated immunoreactivities for collagen IV and neurofilament light chains were found in the affected tissues, indicating vascular and cytoskeletal reactions. CONCLUSIONS: Driven by these neuropathological features, the incidental brain lesion found in this alpaca strongly suggests an ischemic or hemorrhagic etiology. However, since typical hallmarks became verifiable as previously described for other species affected by focal cerebral ischemia, the lesion is more likely related to an ischemic event. Nevertheless, as such cellular alterations might be difficult to distinguish from other brain lesions as for instance caused by inflammatory processes, adjuvant observations and species-related features need to be considered for etiological interpretations. Indeed, the lack of neurological deficits is likely attributed to the location of the lesion within the rostral aspect of the right frontal lobe of the alpacas' brain. Further, fibroblast migration from the meninges likely caused the intralesional scar formation.

Global brain ischemia in a dog with concurrent multiorgan dysfunction syndrome after bite wound trauma.

BACKGROUND: Bite wounds are one of the most common traumatic injuries in dogs and depending on their severity, location, etc., urgent care including antibiotic therapy may be necessary. Serious complications can result from these injuries, such as multiple organ dysfunction syndrome (MODS), as well as a generalized reduction in cerebral perfusion, e.g. during cardiac arrest, shock, or severe hypotension that may cause global brain ischemia (GBI). CASE PRESENTATION: A 5-year-old spayed female Maltese dog was presented with generalized seizures, ataxia, and obtunded mentation. The dog was injured by severe bite wounds that penetrated its abdomen and had received blood transfusions, antibiotic therapy (including metronidazole and cefazoline) and underwent emergency surgery 4 days before its visit. Based on a clinical examination, intracranial hypoxic damage with elevated intra-cranial pressure and MODS were highly suspected, and GBI was confirmed following magnetic resonance imaging. Increased signal intensity diffusely distributed in the olfactory bulb and frontal, temporal, and parietal grey matter was evident on the T2-weighted and fluid attenuated inversion recovery transverse images, along with corresponding high signal intensity observed on diffusion weighted imaging. During the 10-month follow-up period, the clinical signs gradually improved, but intermittent circling and cognitive dysfunction deficits remained. CONCLUSIONS: GBI should be included among the differential diagnoses in case of any peracute non-progressive neurological dysfunction that occurs with episodes of hypotension or hypoxia. The abnormal signal intensity observed on diffusion weighted imaging was a useful indicator for diagnosing this condition. Long-term medical management with antibiotics and anti-convulsant and anti-oxidant therapies were considered to be helpful in managing the GBI concurrent with MODS in this dog.

Temporal and spatial profile of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in ischemic stroke in mice.

Although T cells play important roles in the pathophysiology of ischemic stroke, the dynamics of T cells remains unclear. In cancer, polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) contribute to the maintenance of the tumor microenvironment by suppressing T cells. However, the presence of these cells has never been examined in ischemic brain. Therefore, we examined the temporal and spatial profiles of PMN-MDSCs, which are defined as the CD11b+Ly6ClowLy6G+ cells with higher expression levels of Nox2 and C/EBP Homologous Protein (CHOP) mRNA than normal neutrophil. Fluorescence-activated cell sorter (FACS) analysis showed that the count of CD11b+Ly6ClowLy6G+ cells was increased in the ischemic hemisphere and bone marrow at 72 hours, as well as in the spleen 24 hours after transient middle cerebral artery occlusion in mice. In contrast, the contralateral hemisphere, normal bone marrow, and normal spleen contained few CD11b+Ly6ClowLy6G+ cells. Real-time reverse transcription polymerase chain reaction revealed that CD11b+Ly6ClowLy6G+ cells sorted from brain and spleen 72 hours after ischemia had greater expression of Nox2 and CHOP mRNA than neutrophils in bone marrow, suggesting that these cells constitute PMN-MDSCs. Immunohistochemistry showed that CD11b+Ly6G+ cells were located in the ischemic core and border zone, indicating that PMN-MDSCs might be endemic to these regions. Although neutrophils are believed to invade infarct regions 48-72 hours after ischemia, the present study suggested that some of these cells are in fact PMN-MDSCs. Further studies on the function of PMN-MDSCs might unveil the unknown mechanisms of T cell activation and recruitment in ischemic stroke.

Sequential magnetic resonance imaging changes after suspected global brain ischaemia in a dog.

Sequential magnetic resonance imaging studies over a period of 18 months were performed in a two-year-old pug dog after suspected global brain ischaemia following an anaesthetic accident. The dog was presented with seizures and neurological deficits consistent with a left brainstem and multifocal/diffuse forebrain lesion after an asymptomatic interval of 72 hours following the ischaemic event. Magnetic resonance imaging scans were performed three hours, six weeks, seven and 18 months after the incident. In the acute stage, signal hyperintensity was evident in the occipital and parietal regions of the cerebral cortex and in both rostral caudate nuclei. Slight involvement of the white matter was also noticed. In the chronic phase, the signal hyperintensity in the affected areas of the cortex was diminished and smaller in size, whereas the white matter did not appear to be compromised anymore.

Advances in High-Field MRI.

MRI techniques and systems have evolved dramatically over recent years. These advances include higher field strengths, new techniques, faster gradients, improved coil technology, and more robust sequence protocols. This article reviews the most commonly used advanced MRI techniques, including diffusion-weighted imaging, magnetic resonance spectrography, diffusion tensor imaging, and cerebrospinal fluid flow tracking.