A retrospective study of structural brain lesions identified by magnetic resonance imaging in 114 cats with neurological signs.

Background and Aim: Magnetic resonance imaging (MRI) has been widely used as a non-invasive modality to evaluate neurological organ structures. However, brain MRI studies in cats with neurological signs are limited. This study evaluated the association between patient characteristics, neurological signs, and brain lesion locations identified by MRI. Blood profiles of cats with presumptive inflammatory and structural brain lesions were also determined. Materials and Methods: Medical records of 114 cats that underwent brain MRI were retrospectively reviewed. Cats were categorized into five groups based on the location of their lesion: Cerebrum, brainstem, cerebellum, multifocal, and non-structural. Patient characteristics, neurological signs, and hematological profiles were obtained from their medical records. Disease classification was categorized based on their etiologies. Associations were determined using Fisher's exact test. Blood parameters were compared using the Kruskal-Wallis test. Results: A total of 114 cats met the inclusion criteria. Lesions were identified in the cerebrum (21.1%), brainstem (8.8%), cerebellum (6.1%), multifocal (39.5%), and non-structural (24.6%) of the cats. Common neurological signs included seizure activity (56.1%), cerebellar signs (41.2%), and anisocoria (25.4%). The most common brain abnormality was inflammation (40.4%). There was no significant difference in hematological profiles between cats with presumptive inflammatory and non-inflammatory brain lesions. Neutrophils, platelets, total protein, and globulin concentrations were higher in cats with structural brain lesions. Conclusion: The most common neurological signs and brain disease category were seizure activity and inflammation, respectively. However, the hematological profile did not predict inflammatory and structural brain lesions.

Evaluation of Overshunting between Low and Medium Pressure Ventriculoperitoneal Shunts in Dogs with Severe Hydrocephalus Using Frameless Stereotactic Ventricular Shunt Placement.

Hydrocephalus is a neurological disorder characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the ventricular system of the brain, leading to cerebral ventricular dilation, brain parenchyma compression, and neuronal cell loss. Surgery is an effective method of draining excessive amounts of CSF. Ventriculoperitoneal shunt (VPS) allows excess CSF to divert into the abdomen; this device is the most commonly used in the treatment of hydrocephalus both in veterinary and human patients. This study aims to describe the application of two types of VPS, low-pressure valve and medium-pressure valve, using a frameless stereotactic neuronavigational system in eight severe hydrocephalus in dogs and, in particular, analyze the prevalence of postoperative overshunting. Non-communicating hydrocephalus was found in seven dogs, whereas the rest of them had communicating hydrocephalus caused by traumatic brain injury with a skull fracture. The criteria for pressure valve selection depended on the intraoperative intraventricular pressure (IVP) that was determined by the adaptive manometer, according to the human protocol. Low-pressure valve placement was performed in five dogs, and the others received medium-pressure valve placement. The follow-up period was 2 weeks, 4-12 weeks, and 12 weeks to 12 months. Pre- and postoperative information including neurological signs, CT-Scan or MRI, medical treatment, complications, and ventricular volume were compared in all dogs. Seven dogs showed neurological improvement within 2 weeks after surgery. Overshunting was seen in four dogs who received low-pressure valve placement. Three of them had shunt infections within 4 to 6 weeks after surgery. One dog underwent shunt revision from a low-pressure valve to a medium-pressure valve caused by severe overshunting and progressive neurological signs. In addition, cognitive and learning improvements were evaluated based on the owners' feedback, and neurological signs were examined during the follow-up period in two dogs that received low-pressure valve placement. We conclude that a medium-pressure valve is recommended for overshunting prevention. However, low-pressure valve placement seems to improve cognitive function and learning ability, which is related to an increase in the brain parenchyma observed during long-term monitoring. Moreover, we also report our experience and surgical procedure for frameless stereotactic ventricular shunt placement (FSVSP) in VPS surgery in dogs affected by hydrocephalus.

Protective effects of diarylpropionitrile against hydrogen peroxide-induced damage in human neuroblastoma SH-SY5Y cells.

Oxidative stress is implicated in pathogenesis of neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. The study demonstrates diarylpropionitrile (DPN), an antioxidant selective agonist of estrogen receptor ß, protected human neuroblastoma SH-SY5Y cells against H2O2-induced toxicity by attenuating production of reactive oxygen species, apoptosis, autophagy, NF-κB activation, MAPK p38, JNK and ERK 1/2 signaling pathways, and ß-site amyloid precursor protein cleaving enzyme level, but, interestingly, stimulating Akt pathway. These findings indicate the important potential of DPN to ameliorate oxidative stress-associated damage in neurodegenerative disorders.

Localization of cerebral hypoperfusion in dogs with refractory and non-refractory epilepsy using [99mTc] ethyl cysteinate dimer and single photon emission computed tomography.

To evaluate the localization of functional deficit area in epileptogenic zones of the brain in seven refractory and seven non-refractory epilepsy dogs using technetium 99m labeled with ethyl cysteinate dimer and interictal single photon emission computed tomography [99mTc-ECD SPECT] co-registration with Magnetic Resonance Imaging (MRI). Regions showing perfusion deficits in the SPECT images were analyzed by using the standard semiquantitative evaluation method to compare the level of cortical perfusion to the maximum number of counts within the cerebellum (max C), considered the area of reference. This study showed that SPECT imaging revealed abnormalities in several regions of the brain in both epilepsy groups. The refractory epilepsy dogs showed more frequency area of hypoperfusion in temporal lobe than non-refractory group with not statistically significance (P=0.28). The result suggests the lesion in temporal might be relevance with refractory epilepsy in canine patients.

Canine Vertebral Screw and Rod Fixation System: Design and Mechanical Testing.

OBJECTIVES: To develop the canine vertebral screw and rod fixation system (CVSRF) and to compare the biomechanical properties between CVSRF and the screw and polymethylmethacrylate (Screw-PMMA) technique for internal fixation of the vertebral column in dogs. METHODS: The CVSRF consisted of vertebral screws with monoaxial side-loaded head, rods and specific inner screws connecting rod to the screw head. The CVSRF prototype was made from titanium alloy and manufactured by the rapid prototype machine. Vertebrectomy models were simulated by ultra-high-molecular-weight polyethylene blocks and tested with the CVSRF system (n = 8) and the Screw-PMMA technique (n = 8). The models were developed according to the American Society for Testing and Materials (ASTM F-1717-04). The biomechanical parameters were the compressive bending yield load, the compressive bending stiffness, the compressive ultimate load and the load displacement curve. RESULTS: The mean values of the compressive bending yield load, compressive bending stiffness and compressive ultimate load of the CVSRF were significantly higher than those of the Screw-PMMA technique (p < 0.01). The load displacement curve of the CVSRF showed higher rigidity and durability than that of the Screw-PMMA technique. CLINICAL SIGNIFICANCE: This mechanical study indicated that the CVSRF system can be used for canine vertebral stabilization and the biomechanical properties were better than those for the Screw-PMMA device.

Neuroprotection of N-benzylcinnamide on scopolamine-induced cholinergic dysfunction in human SH-SY5Y neuroblastoma cells.

Alzheimer's disease, a progressive neurodegenerative disease, affects learning and memory resulting from cholinergic dysfunction. Scopolamine has been employed to induce Alzheimer's disease-like pathology in vivo and in vitro through alteration of cholinergic system. N-benzylcinnamide (PT-3), purified from Piper submultinerve, has been shown to exhibit neuroprotective properties against amyloid-ß-induced neuronal toxicity in rat cortical primary cell culture and to improve spatial learning and memory of aged rats through alleviating oxidative stress. We proposed a hypothesis that PT3 has a neuroprotective effect against scopolamine-induced cholinergic dysfunction. PT-3 (125-200 nM) pretreatment was performed in human neuroblastoma SH-SY5Y cell line following scopolamine induction. PT-3 (125-200 nM) inhibited scopolamine (2 mM)-induced generation of reactive oxygen species, cellular apoptosis, upregulation of acetylcholinesterase activity, downregulation of choline acetyltransferase level, and activation of p38 and JNK signalling pathways. These findings revealed the underlying mechanisms of scopolamine-induced Alzheimer's disease-like cellular dysfunctions, which provide evidence for developing drugs for the treatment of this debilitating disease.

Potential role of N-benzylcinnamide in inducing neuronal differentiation from human amniotic fluid mesenchymal stem cells.

Neurodegenerative disorders are characterized by chronic and progressive loss of neurons in structure and function related to aging, such as Alzheimer's disease, the latter characterized by the degeneration of cholinergic neurons in basal forebrain connected to the cerebral cortex and hippocampus. Amniotic fluid mesenchymal stem cells (AF-MSCs) have been proposed as one of the candidates for stem cell therapy of nervous system disorders. This study demonstrates that incubation of AF-MSCs, obtained from 16 to 20 week pregnant women, with 10ng/ml bone morphogenetic protein (BMP)-9 for 48h in conditioned medium resulted in transdifferentiation to cholinergic neuronal-like cells. This phenomenon could also be obtained with N-benzylcinnamide (PT-3). Pre-treatment for 1h with 10nM PT-3 augmented BMP-9 transdifferentiation effect, elevated ßIII-tubulin cell numbers and fluorescence intensity of immunoreactive ChAT, ameliorated BMP-9-related production of reactive oxygen species and enhanced anti-apoptosis status of the neuronal-like cells. The transdiffirentiation process was accompanied by increased p53 but decreased Notch1 and SIRT1 (p53 deacetylase) levels, and activation of p38, ERK1/2 MAPK, and PI3K/Akt pathways, in concert with inactivation of JNK, all of which were accentuated by PT-3 pre-treatment. These findings suggest that N-benzylcinnamide may provide a useful adjuvant in BMP-9-induced transdifferentiation of AFMSCs into ultimately cholinergic neurons.

Protective roles of N-benzylcinnamide on cortex and hippocampus of aged rat brains.

Brain aging has been associated with oxidative stress leading to inflammation and apoptosis. The protective effects and underlying mechanisms of N-benzylcinnamide (PT-3), purified from Piper submultinerve, on brains of 90-week-old Wistar rats were investigated following daily intraperitoneal injection with 1.5 mg of PT-3/kg of body weight for 15 days. PT-3 treatment improved spatial learning and memory of aged rats and caused significant changes in brain frontal cortex, hippocampus, and temporal cortex in parameters associated with oxidative stress (decreased reactive oxygen species production and iNOS and nNOS levels), inflammation (reduced levels of IL-1ß and IL-6), apoptosis (reduced levels of Bax and activated caspase-3, and elevated level of Bcl-2), and signaling pathways related to inflammation and apoptosis (decreased amounts of phospho-JNK and -p38, increased phospho-Akt level and no change in phospho-ERK1/2 content) compared to controls. PT-3 treatment also inhibited aged rat brain AChE activity. These results suggest that PT-3 with its intrinsic antioxidant and AChE inhibitory properties has therapeutic potential in ameliorating, in part, age-associated damages to the brain.

Neuroprotective effects of diarylpropionitrile against ß-amyloid peptide-induced neurotoxicity in rat cultured cortical neurons.

Alzheimer's disease is a major cause of dementia in the elderly that involves a ß-amyloid peptide (Aß)-induced cascade of an increase in oxidative damage and inflammation. The present study demonstrated the neuroprotective effects of diarylpropionitrile (DPN), a non-steroidal estrogen receptor ß selective ligand, against 10 µM Aß1-42-induced oxidative stress and inflammation in primary rat cortical cell culture. Pre-treatment with 1-100 nM DPN significantly decreased neuronal cell death by increasing cell viability through a significant attenuation in the reactive oxygen species level, downregulation of pro-apoptotic activated caspase-3 and Bax, and upregulation of anti-apoptotic Bcl-2, thereby mitigating apoptotic morphological alterations. DPN pre-treatment decreased the expression levels of pro-inflammatory cytokines IL-1ß and IL-6 through attenuation of Aß1-42-induced phosphorylation of mitogen-activated protein kinases JNK and p38. In addition, DPN enhanced ERK1/2 and Akt phosphorylation depressed by Aß1-42. These findings suggest that DPN protects neurons from Aß1-42-induced neurotoxicity through a variety of mechanisms, ranging from anti-oxidation, anti-apoptosis, through to anti-inflammation.

Neuroprotection by diarylpropionitrile in mice with spinal cord injury.

The initial impact of spinal cord injury (SCI) often results in inflammation leading to irreversible damage with consequent loss of locomotor function. Minimal recovery is achieved once permanent damage has occurred. Using a mouse model of SCI we observed a transitory increase followed by a rapid decline in gene expression and protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of cellular anti-oxidative genes. Immediate treatment with diarylpropionitrile (DPN), a non-steroidal selective estrogen receptor ß ligand, resulted in a significant increase in Nrf2 levels, and reduction of inflammation and apoptosis compared to untreated SCI animals. Furthermore, DPN-treatment improved locomotor function within 7 days after induction of SCI. DPN acted through activation of PI3K/ Akt pathway, known to be involved in down-regulation of apoptosis and up-regulation of cell survival in injured tissues. These findings suggest that immediate activation of cellular anti-oxidative stress mechanisms should provide protection against irreversible tissue damage and its profound detrimental effect on locomotor function associated with SCI.

Estrogen receptor ß ligand therapy activates PI3K/Akt/mTOR signaling in oligodendrocytes and promotes remyelination in a mouse model of multiple sclerosis.

The identification of a drug that stimulates endogenous myelination and spares axon degeneration during multiple sclerosis (MS) could potentially reduce the rate of disease progression. Using experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, we have previously shown that prophylactic administration of the estrogen receptor (ER) ß ligand 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) decreases clinical disease, is neuroprotective, stimulates endogenous myelination, and improves axon conduction without altering peripheral cytokine production or reducing central nervous system (CNS) inflammation. Here, we assessed the effects of therapeutic DPN treatment during peak EAE disease, which represents a more clinically relevant treatment paradigm. In addition, we investigated the mechanism of action of DPN treatment-induced recovery during EAE. Given that prophylactic and therapeutic treatments with DPN during EAE improved remyelination-induced axon conduction, and that ER (α and ß) and membrane (m)ERs are present on oligodendrocyte lineage cells, a direct effect of treatment on oligodendrocytes is likely. DPN treatment of EAE animals resulted in phosphorylated ERß and activated the phosphatidylinositol 3-kinase (PI3K)/serine-threonine-specific protein kinase (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, a pathway required for oligodendrocyte survival and axon myelination. These results, along with our previous studies of prophylactic DPN treatment, make DPN and similar ERß ligands immediate and favorable therapeutic candidates for demyelinating disease.

Protective role of N-trans-feruloyltyramine against ß-amyloid peptide-induced neurotoxicity in rat cultured cortical neurons.

Enhanced oxidative stress and inflammation play important roles in the pathogenesis of Alzheimer's disease (AD). Amyloid ß-peptide (Aß), a major component of amyloid plaques, is considered to have a causal role in the development and progress of AD by being the initiator of a pathological cascade leading to oxidative stress. The present study investigated the effect of N-trans-feruloyltyramine (NTF) purified from Polyalthia suberosa, an alkaloid shown to protect against oxidative stress and cell death. Pre-treatment of rat primary cortical cell cultures with 25-250µM NTF significantly attenuated 10µM Aß(1-42)-induced neuronal death in a dose-dependent manner. Apoptotic cell death was demonstrated morphologically as well as by detection of the presence of activated caspase-3 and Bax, levels of which could be reduced by NTF pre-treatment. NTF also reduced production of reactive oxygen species induced by Aß(1-42). These findings suggest that the protective effect of NTF against Aß(1-42)-induced neuronal death might be due to its antioxidative property.

The use of flow cytometry as a diagnostic test for malaria parasites.

A total of 453 clinical blood samples were determined for malaria parasites by flow cytometric assay (FCM) and reagents from Sysmex Corporation, Japan. In this study, the FCM greatly simplified and accelerated parasite detection, with sensitivity of 91.26%, specificity 86.28% and accuracy 87.42%. Overall, the parasite counts by flow cytometric measurement correlated well with the parasitemia measured by microscopic assay (regression coefficient = 0.9409). The detection limit was 0.05-0.1% parasitemia. No evidence of malaria parasites in either blood donor volunteers or other disease patients groups was determined by FCM. However, 48 samples who had been treated with antimalarial drugs and whose parasite microscopic counts were negative, showed false-positive results. When the data of these 48 samples were analyzed, they were found to have high levels of reticulocytes, ranging from 2.0-18.9%. This finding suggested that a high reticulocyte concentration in the blood may interfere with the performance of the FCM. Further improvement, by eliminating this interference, will make the FCM one of the most promising tests for malaria diagnosis.