Transplantation of mature adipocyte-derived dedifferentiated fat cells promotes locomotor functional recovery by remyelination and glial scar reduction after spinal cord injury in mice.

Mature adipocyte-derived dedifferentiated fat cells (DFAT) have a potential to be useful as new cell-source for cell-based therapy for spinal cord injury (SCI), but the mechanisms remain unclear. The objective of this study was to examine whether DFAT-induced functional recovery is achieved through remyelination and/or glial scar reduction in a mice model of SCI. To accomplish this we subjected adult female mice (n=22) to SCI. On the 8th day post-injury locomotor tests were performed, and the mice were randomly divided into two groups (control and DFAT). The DFAT group received stereotaxic injection of DFAT, while the controls received DMEM medium. Functional tests were conducted at repeated intervals, until the 36th day, and immunohistochemistry or staining was performed on the spinal cord sections. DFAT transplantation significantly improved locomotor function of their hindlimbs, and promoted remyelination and glial scar reduction, when compared to the controls. There were significant and positive correlations between promotion of remyelination or/and reduction of glial scar, and recovery of locomotor function. Furthermore, transplanted DFAT expressed markers for neuron, astrocyte, and oligodendrocyte, along with neurotrophic factors, within the injured spinal cord. In conclusion, DFAT-induced functional recovery in mice after SCI is probably mediated by both cell-autonomous and cell-non-autonomous effects on remyelination of the injured spinal cord.

Dog leukocyte antigen class II alleles and haplotypes associated with meningoencephalomyelitis of unknown origin in Chihuahuas.

Idiopathic non-infectious meningoencephalomyelitis (NIME), which is thought to be an immune-mediated disease, is a common inflammatory disease in dogs. Meningoencephalomyelitis of unknown origin (MUO), a subgroup of NIME, consists of necrotizing meningoencephalitis (NME), necrotizing leukoencephalitis, and granulomatous meningoencephalomyelitis. Recent studies have shown associations between disease development and dog leukocyte antigen (DLA) class II genes in NME in Pugs and in NIME in Greyhounds. This study focused on Chihuahuas, which have a high incidence of MUO and are one of the most common dog breeds in Japan. Because the development of MUO seems to be associated with DLA class II genes, we aimed to evaluate the association between DLA class II genes and MUO development in Chihuahuas. Blood samples were obtained from 22 Chihuahuas with MUO (MUO group) and 46 without neurological diseases (control). The allele sequences of three DLA class II loci were determined, and haplotypes were estimated from these data. In total, 23 haplotypes were detected. The frequency of one haplotype (DLA-DRB1*015:01--DQA1*006:01--DQB1*023:01) was significantly higher in the MUO group than in the control group (odds ratio, 7.11; 95% confidence interval, 1.37-36.81; P=0.0141). The results suggest that the development of MUO in Chihuahuas may be associated with DLA class II genes. Because the identified risk haplotypes differed from those of other breeds, the pathogenesis of NIME-related diseases may differ among dog breeds.

Neurosurgery in canine epilepsy.

Epilepsy surgery is functional neurosurgery applied to drug-resistant epilepsy. Although epilepsy surgery has been established and achieves fair to good outcomes in human medicine, it is still an underdeveloped area in veterinary medicine. With the spread of advanced imaging and neurosurgical modalities, intracranial surgery has become commonplace in the veterinary field, and, therefore, it is natural that expectations for epilepsy surgery increase. This review summarizes current standards of intracranial epilepsy surgery in human medicine and describes its current status and expectation in veterinary medicine. Intracranial epilepsy surgery is classified generally into resection surgery, represented by cortical resection, lobectomy, and lesionectomy, and disconnection surgery, such as corpus callosotomy and multiple subpial transection. In dogs with drug-resistant epilepsy, corpus callosotomy is available as a disconnection surgery for generalized epilepsy. However, other types of disconnection and resection surgeries for focal epilepsy are limited to experimental studies in laboratory dogs and/or anecdotal case reports of lesionectomy, such as tumor or encephalocele removal, without epileptogenic evidence. Veterinary epilepsy surgery is a new and challenging neurosurgery field; with the development of presurgical evaluations such as advanced electroencephalography and neuroimaging, it may become more readily practiced.

Cerebrospinal fluid flow on time-spatial labeling inversion pulse images before and after treatment of congenital hydrocephalus in a dog.

A 3-month-old male cross-breed dog presented with signs of progressive diffuse brain disease. Noncommunicating congenital hydrocephalus concurrent with cervical syringomyelia was diagnosed on magnetic resonance images. On time-spatial labeling inversion pulse (Time-SLIP) images CSF flow through the mesencephalic aqueduct was poorly defined and there was flow into the syrinx across the craniocervical junction. After percutaneous ventricular drainage and ventriculoperitoneal shunting, CSF flow through the aqueduct was clearly detected and flow into the syrinx disappeared. In addition, CSF flow in the subarachnoid space at the pons and ventral aspect of the cervical subarachnoid space was restored. Signs of neurological dysfunction improved after ventriculoperitoneal shunting and the cerebral parenchyma was increased in thickness on 2-year follow-up computed tomography images. Patterns of CSF flow on Time-SLIP images before and after CSF drainage or ventriculoperitoneal shunting aid in clarifying disease pathogenesis and confirm effects of CSF drainage.

Corpus Callosotomy in 3 Cavalier King Charles Spaniel Dogs with Drug-Resistant Epilepsy.

Corpus callosotomy (CC) is an established palliative surgery for human patients with drug-resistant epilepsy (DRE), especially those with generalized seizures and multiple or unknown epileptogenic focus. However, there are no reports to describe CC in canine patients with epilepsy. Three client-owned Cavalier King Charles Spaniels with DRE are included in this case series. In presurgical evaluations, an apparent epileptogenic zone was not detected in each dog and CC was conducted. Total CC was performed in one dog, whereas the other two received partial CC. One dog recovered from surgery without any complications, but died suddenly by an unknown cause at 10 h after surgery. For the other two dogs, postoperative evaluations including seizure outcomes, complications, and quality of life of the dogs and owners were assessed for at least 12 months. Both dogs showed a remarkable decrease in seizure frequency (averaged 80.3% reduction) and severity after surgery. The antiseizure medications were maintained, and not only the mentation and activity of the dogs, but also the quality of life of dogs and owners were improved postoperatively. Although technical improvement and more large-scale studies are needed, CC is a treatment option for dogs with DRE in veterinary medicine.

Inflammatory myopathy with severe tongue atrophy in Pembroke Welsh Corgi dogs.

A disease characterized by tongue and facial muscle atrophy has been recognized sporadically among Pembroke Welsh Corgi (PWC) dogs in Japan. The present study describes the pathologic findings of this canine syndrome. Histopathologic examinations were performed in 2 dogs, including a case of muscular biopsy. Identification and characterization of autoantibodies were attempted by fluorescent antibody test (FAT) and Western blot (WB) by using sera from 7 PWC dogs with typical clinical features, 6 PWC dogs with other clinical signs, and 2 from other breeds with polymyositis. Clinically, the 7 affected PWC dogs exhibited dysphagia with severe tongue atrophy, facial muscular atrophy, and occasional walking difficulty. Histopathologic examinations of the 2 dogs with clinical symptoms revealed moderate to severe inflammatory lesions characterized by lymphohistiocytic infiltration and muscular atrophy in the tongue and/or femoral muscles. The tongue lesions were very severe and accompanied by diffuse fatty infiltration. There were no major lesions in the nervous tissues examined. By FAT, an autoantibody against the cross striation of skeletal muscle was detected in sera from 5 affected PWC dogs. By using WB analysis, the autoantibodies recognized a 42-kDa molecule in striated muscle but not in the nervous tissues. All of the findings indicated that the unique disease of PWC dogs might be generalized inflammatory myopathy, whereas the detailed etiology concerning the dominant involvement of tongue muscles and the role of the autoantibody in the canine disease remain to be clarified.

Magnetic resonance imaging features and clinical signs associated with presumptive and confirmed progressive myelomalacia in dogs: 12 cases (1997-2008).

OBJECTIVE: To characterize clinical signs and findings from magnetic resonance imaging (MRI) and CSF analysis for dogs with progressive myelomalacia (PM) diagnosed on the basis of clinical and histologic features. DESIGN: Retrospective case series. ANIMALS: 5 dogs with confirmed PM and 7 with presumptive PM evaluated from 1997 through 2008. PROCEDURES: Medical records of study dogs were reviewed, and clinical signs and MRI and CSF findings were evaluated. A clinical diagnosis of PM was made on the basis of detection of disk-associated spinal cord compression via MRI and progression of clinical signs from initial paraparesis or paraplegia to thoracic limb lower motor neuron paresis to tetraplegia associated with cranial migration of the extent of cutaneous trunci reflex extinction and analgesia, terminating in death due to respiratory paralysis. RESULTS: All dogs were paraplegic and had signs of lower motor neuron lesions. As revealed by MRI of the vertebral column, the length of abnormal signal intensity was more than 6-fold, compared with the body length of L2. In some dogs, these abnormal MRI findings were observed before PM was clinically diagnosed. The CSF examination revealed hemorrhagic xanthochromia. CONCLUSIONS AND CLINICAL RELEVANCE: A hyperintense region of the spinal cord > 6 times the length of L2 on T2-weighted imaging might be a characteristic MRI finding of PM. In some dogs, such MRI findings were observed before PM was clinically diagnosed. Progressive myelomalacia may thus be diagnosable at the early stage through MRI and CSF examination before signs of PM develop.

Repeated surgical treatment and long-term outcome of a cat with vertebral vascular hamartoma.

A 30-month-old Maine Coon presented with progressive proprioceptive ataxia, paraparesis, thoracolumbar pain, and decreased appetite. An extradural mass was detected within the left side of the 13th thoracic vertebral canal that compressed the spinal cord on magnetic resonance (MR) and was considered to be mineralized on computed tomography (CT) images. The resected mass was diagnosed as a vertebral vascular hamartoma. Clinical signs improved, but recurrence was diagnosed by MR and CT imaging at 7 months after surgery. Repeated excisional surgery yielded the same diagnosis and the clinical signs abated. Fifteen months after the second surgery, there was apparent vertebral deformation, but there was no further change on CT images by 29 months.

Ocular granulomatous meningoencephalomyelitis in a dog: magnetic resonance images and clinical findings.

A 4-year-old female miniature dachshund presented with a history of progressive decrease in vision, neck pain, and ataxia for which an MRI was performed 21 days after the initial consultation. The optic nerves showed isointensities on T1- (T1W) and T2-weighted (T2W) images that were enhanced by the contrast medium. The optic chiasm was swollen. Other parts of the cerebral parenchyma, not only the visual pathway, showed symmetrical hyperintensities on T2W images. Cerebrospinal fluid showed increased anti-GFAP autoantibodies. The dog received corticosteroid therapy despite which she exhibited anorexia, vomiting, and lethargy. Hence, a follow-up MRI was repeated 30 days after the initial consultation in which T2W images showed enlargement of the hyperintense area. The dog died 45 days after the initial consultation. Postmortem pathological examination confirmed a diagnosis of granulomatous meningoencephalomyelitis (GME).

Magnetic resonance imaging and computed tomography findings of vertebral osteosarcoma in a cat.

An 8-year-old female Persian cat with a gait disorder was brought to our hospital. Pelvic limb mobility had gradually reduced over the preceding 3 months, then rapidly deteriorated 2 weeks before consultation. Signs also occurred in the thoracic limbs. With a tentative diagnosis of neural disease, magnetic resonance imaging and computed tomography were performed. T1-weighted imaging showed isointensity in the seventh cervical vertebra, while T2-weighted imaging revealed hypointensity. Contrast-enhanced T1-weighted imaging revealed a uniformly enhancing mass. Extirpation of the mass relieved the clinical signs, leading to disappearance of the neurological signs. The histopathological examination suggested osteosarcoma.

Symptomatic tongue atrophy due to atypical polymyositis in a Pembroke Welsh Corgi.

A three-year-old, 7.3-kg, female Pembroke Welsh Corgi exhibited symptomatic tongue atrophy, crinkling of the tip of the tongue, dysphagia and excessive salivation. Neurological examination suggested multiple cranial neuropathy, but polymyositis was diagnosed by magnetic resonance imaging and muscle biopsy. The dog did not respond to prednisolone treatment and died from aspiration pneumonia 22 months after the first presentation. Post-mortem histopathological examination of the tongue revealed marked myofiber loss and fibrosis with multifocal infiltration of mixed mononuclear cells. Similar findings were also observed in the masticatory muscles and quadriceps without abnormality of peripheral nerves or evidence of infection. Symptomatic tongue atrophy occurring in the course of polymyositis has not been reported previously in dogs.

MRI of secondary cervical syringomyelia in four cats.

This report describes the use of magnetic resonance imaging (MRI) to diagnose cervical syringomyelia in 4 cats. MRI revealed enlargement of the lateral ventricle in all the cats. Of the 4 cases, MRI revealed herniation of the cerebellum in 3 cats, an isolated fourth ventricle in 1 cat, severe hydrocephalus in 2 cats and brain masses in 1 cat. In this report, the cervical syringomyelia in these cats may have been due to formation of a secondary syrinx (enlargement of the central canal) as a result of blockage of flow in the outlet of the fourth ventricle caused by FIP encephalomyelitis or secondary cerebellar tonsillar herniation caused by increased intracranial pressure due to intracranial masses or may have been due to caudal compression of the cerebellum caused by increased intracranial pressure due to hydrocephalus.

Use of three-dimensional time-of-flight magnetic resonance angiography at 1.5 Tesla to evaluate the intracranial arteries of 39 dogs with idiopathic epilepsy.

OBJECTIVE: To assess visualization of the intracranial arteries and internal carotid artery (ICA) on 3-D time-of-flight (TOF) magnetic resonance angiography (MRA) images obtained at 1.5 T and to investigate factors that affect the image quality of those arteries in dogs. ANIMALS: 39 dogs with idiopathic epilepsy. PROCEDURES: Each dog underwent 3-D TOF MRA, and 5 pairs of intracranial arteries, the basilar artery, and both ICAs were evaluated. Each artery was assigned an image-quality score on a scale of 0 to 3, where 0 = poor and 3 = excellent. Multivariable regression analysis was used to assess whether age, body weight (BW), serum total cholesterol concentration, intracranial volume (ICV), and mean arterial pressure were significantly associated with the image quality of each vessel. RESULTS: In all dogs, the image-quality score was 2 or 3 for the proximal middle cerebral arteries, basilar artery, and caudal aspect of the caudal communicating arteries. In some dogs, the rostral cerebellar arteries, rostral aspect of the caudal communicating arteries, and middle and rostral aspects of the ICA were poorly visualized. For various arteries, image quality was negatively associated with age and positively associated with BW and ICV. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that 3-D TOF MRA images obtained at 1.5 T did not consistently and clearly delineate the ICA and narrow or peripheral intracranial arteries of dogs; therefore, careful attention is required when such images are assessed. Patient age, BW, and ICV can also affect the image quality of some intracranial arteries on 3-D TOF MRA images. (Am J Vet Res 2019;80:480-489).

Impact of intracranial hypertension on the short-term prognosis in dogs undergoing brain tumor surgery.

The present study used data from anesthetic records to analyze variables of intracranial pressure (ICP) during brain tumor surgery or in the early postoperative period as prognostic indicators in dogs. Data from 17 dogs which were scheduled to undergo elective craniotomy for brain tumor surgery from 2009 to 2012 were included. Of these, five (29.4%) died during 14 days after the surgery because of respiratory failure following pneumonia (n=2), euthanasia due to difficulty in treatment of status epilepticus (n=1), tumor-bed hematoma (n=1), and unknown reason (n=1). In the 12 surviving dogs, neurological signs were improved or resolved at discharge. All dogs were administered midazolam and droperidol-fentanyl as premedication. General anesthesia was induced using propofol maintained on isoflurane and oxygen. Direct ICP was obtained via a Codman Microsensor strain gauge transducer. ICP hypertension (>13 mmHg) measured after 15 min of recovery from the moment after discontinuation of anesthesia by turning off the vaporizer dial was associated with poor prognosis (odds ratio, 20.00; 95% confidence interval, 1.39-287.60, P=0.028). This suggests that intracranial pressure influences the postoperative mortality rate in dogs undergoing brain tumor surgery.

mRNA expression of tumor-associated genes in canine grade I meningiomas.

This study was undertaken to establish a method for measuring mRNA expression by using real-time RT-PCR in the diagnosis of canine meningiomas. When performing real-time RT-PCR, it is essential to include appropriate control tissues and to select appropriate housekeeping genes as an internal standard. Based on the results of our study, RPS18 constitutes a suitable internal standard for the comparison of mRNA expression between normal meninges and meningiomas. The results showed increased mRNA expression of VEGFA and EGFR; however, mRNA expression of KDR was reduced. Measuring mRNA expression by using real-time RT-PCR with appropriate control tissues and internal standards can provide useful information to understanding the pathogenesis of canine meningiomas, which corresponds with immunohistochemical findings.

Methods of olfactory ensheathing cell harvesting from the olfactory mucosa in dogs.

Olfactory ensheathing cells are thought to support regeneration and remyelination of damaged axons when transplanted into spinal cord injuries. Following transplantation, improved locomotion has been detected in many laboratory models and in dogs with naturally-occurring spinal cord injury; safety trials in humans have also been completed. For widespread clinical implementation, it will be necessary to derive large numbers of these cells from an accessible and, preferably, autologous, source making olfactory mucosa a good candidate. Here, we compared the yield of olfactory ensheathing cells from the olfactory mucosa using 3 different techniques: rhinotomy, frontal sinus keyhole approach and rhinoscopy. From canine clinical cases with spinal cord injury, 27 biopsies were obtained by rhinotomy, 7 by a keyhole approach and 1 with rhinoscopy. Biopsy via rhinoscopy was also tested in 13 cadavers and 7 living normal dogs. After 21 days of cell culture, the proportions and populations of p75-positive (presumed to be olfactory ensheathing) cells obtained by the keyhole approach and rhinoscopy were similar (~4.5 x 106 p75-positive cells; ~70% of the total cell population), but fewer were obtained by frontal sinus rhinotomy. Cerebrospinal fluid rhinorrhea was observed in one dog and emphysema in 3 dogs following rhinotomy. Blepharitis occurred in one dog after the keyhole approach. All three biopsy methods appear to be safe for harvesting a suitable number of olfactory ensheathing cells from the olfactory mucosa for transplantation within the spinal cord but each technique has specific advantages and drawbacks.

A feline case of isolated fourth ventricle with syringomyelia suspected to be related with feline infectious peritonitis.

A one-year-old female cat was unable to stand. Magnetic resonance imaging was performed, and an enlargement of the lateral, third, and fourth ventricles and syringomyelia were detected. The cat was diagnosed with an isolated fourth ventricle (IFV) with syringomyelia. The serum isoantibody test for the feline infectious peritonitis (FIP) virus was 1:3,200. After the cat died, a pathological examination revealed nonsuppurative encephalomyelitis. We suspected that the IFV, detected in the cat, was associated with FIP encephalomyelitis. To our knowledge, there has been no report on IFV in veterinary medicine.

A canine case of necrotizing meningoencephalitis for long-term observation: clinical and MRI findings.

A 3-year-old female pug presented with general seizure following a partial seizure. During the remaining 48 months till death, the dog showed various neurological signs such as disturbance of consciousness, myoclonus and various types of partial seizure after each occurrence of the seizure clusters, and the dog eventually exhibited inability to stand and dementia. Magnetic resonance imaging findings revealed atrophy of the brain over the course of the disease. On histopathological analysis, the dog was diagnosed with necrotizing meningoencephalitis. This case of a canine necrotizing meningoencephalitis observed over the long term is valuable.

Malignant peripheral nerve sheath tumor arising from the spinal canal in a cat.

A 10-year-old female mongrel cat with back pain was brought to the Nihon University Animal Medical Center. Palpation demonstrated a mass in the back region. Radiography revealed partial destruction of the processus spinosus and the arch of the T8 and T9 vertebrae. On magnetic resonance imaging, the mass was found to have compressed the spinal cord and extended to the outside of the spinal canal. We performed extirpation of the mass, and confirmed that it arose from the spinal canal. Histopathologically, the mass was a malignant peripheral nerve sheath tumor.

Degenerative myelopathy in the Collie breed: a retrospective immunohistochemical analysis of superoxide dismutase 1 in an affected Rough Collie, and a molecular epidemiological survey of the SOD1: c.118G>A mutation in Japan.

Canine degenerative myelopathy (DM) is an adult-onset, progressive neurodegenerative disease that occurs in multiple dog breeds. A DM-associated mutation of the canine superoxide dismutase 1 (SOD1) gene, designated as c.118G>A (p.E40K), has been implicated as one of pathogenetic determinants of the disease in many breeds, but it remains to be determined whether the c.118G>A mutation is responsible for development or progression of DM in Collies. Previously, a Rough Collie was diagnosed clinically and histopathologically as having DM in Japan, suggesting the possibility that the Collie breed may be predisposed to DM due to the high frequency of c.118G>A in Japan. In this study, accumulation and aggregate formation of SOD1 protein were retrospectively demonstrated in the spinal cord of the DM-affected dog by immunohistochemical analysis. Furthermore, a molecular epidemiological survey revealed a high carrier rate (27.6%) and mutant allele frequency (0.138) of c.118G>A in a population of Collies in Japan, suggesting that the Collie breed may be predisposed to DM associated with c.118G>A, and the prevention of DM in Collies in Japan should be addressed through epidemiological and genetic testing strategies.