Biomedical subjects

K R Muñana

Publications and source records attributed to K R Muñana.

13 recordsLinked to original sources

PubMed2001

Risk factors for development of status epilepticus in dogs with idiopathic epilepsy and effects of status epilepticus on outcome and survival time: 32 cases (1990-1996).

OBJECTIVE: To identify risk factors for episodes of status epilepticus (SE) in dogs with idiopathic epilepsy and determine how SE affects long-term outcome and survival time. DESIGN: Retrospective study. ANIMALS: 32 dogs with idiopathic epilepsy. PROCEDURE: Information on signalment, seizure onset, initiation of treatment, anticonvulsants administered, number of episodes of SE, overall seizure control, and long-term outcome was obtained from medical records and through telephone interviews. Differences between dogs that did and did not have episodes of SE were evaluated statistically. RESULTS: 19 (59%) dogs had 1 or more episodes of SE. Body weight was the only variable significantly different between dogs that did and did not have episodes of SE. Thirteen dogs (9 that did not have episodes of SE and 4 that did) were still alive at the time of the study and were > or = 10 years old. Six of the 19 (32%) dogs that had episodes of SE died of causes directly attributed to the seizure disorder. Mean life spans of dogs that did and did not have episodes of SE were 8.3 and 11.3 years, respectively. Survival time was significantly different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a substantial percentage of dogs with idiopathic epilepsy will have episodes of SE. Dogs with greater body weights were more likely to have episodes of SE, and early appropriate seizure treatment did not appear to decrease the risk that dogs would have episodes. Most dogs with idiopathic epilepsy had an expected life span, but survival time was shorter for dogs that had episodes of SE.

Animals↗

PubMed2001

Predictors of outcome after dorsal decompressive laminectomy for degenerative lumbosacral stenosis in dogs: 69 cases (1987-1997).

OBJECTIVE: To identify predictive factors of long-term outcome after dorsal decompressive laminectomy for the treatment of degenerative lumbosacral stenosis (DLSS) in dogs. DESIGN: Retrospective study. SAMPLE POPULATION: 69 client-owned dogs. PROCEDURE: Medical records of dogs that had undergone dorsal laminectomy at North Carolina State University and the University of Tennessee between 1987 and 1997 were reviewed. Dogs with diskospondylitis, traumatic lesions, or neoplasia of the lumbosacral region were excluded. All dogs had evidence of cauda equina compression on myelography, epidurography, computed tomography, or magnetic resonance imaging, along with subsequent confirmation of the lesion at surgery. Follow-up was performed by telephone inquiries to the referring veterinarian, the owner, or both, using a detailed questionnaire. RESULTS: The outcome was excellent or good in 54 of 69 (78%) dogs over a mean follow-up period of 38+/-22 months. Five of these 54 dogs had been incontinent for a median of 2 weeks prior to surgery. Six of the 15 dogs with a poor outcome had been incontinent for a median of 8 weeks before surgery. A significant correlation was detected between the presence of urinary and fecal incontinence prior to surgery and outcome. When duration of signs was considered, urinary incontinence was the only variable that significantly affected outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Decompressive laminectomy is an effective treatment for DLSS, although dogs with urinary or fecal incontinence have a worse prognosis than dogs that are continent before surgery. Chronic urinary incontinence is a predictor of poor outcome for dogs with DLSS.

Animals↗

PubMed2001

Infection of fetal feline brain cells in culture with Bartonella henselae.

Bartonella henselae is known to cause central nervous system (CNS) disease in humans, and neurological signs have been observed in experimentally infected cats. However, the pathogenesis of CNS disease remains unclear. This study was undertaken to determine whether B. henselae infects feline fetal brain cells in vitro. Microglial-cell- and astrocyte-enriched cultures were inoculated with B. henselae. Giménez staining identified bacterial organisms within microglial cells by day 7 postinoculation. The viability of the intracellular bacteria was demonstrated by incubating cultures with gentamicin and plating cell lysate on agar. Electron microscopy identified intracellular organisms with characteristic Bartonella morphology but identified no ultrastructural abnormalities within infected microglial cells. No evidence of infection was seen in Bartonella-inoculated astrocyte cultures. These findings suggest a role for microglia in the pathogenesis of B. henselae-associated neurological disease.

Animals↗

PubMed2001

Development of a functional scoring system in dogs with acute spinal cord injuries.

OBJECTIVES: To develop and compare the reliability of 2 methods of scoring pelvic limb gait in dogs recovering from thoracolumbar spinal cord injuries and to use this scoring system to determine the rate and level of functional recovery of dogs with acute thoracolumbar intervertebral disk herniations. ANIMALS: 46 dogs with spinal cord injuries resulting from intervertebral disk herniations. PROCEDURE: Dogs' gaits were videotaped at different time intervals after injury. In phase 1 of the study, the stages of recovery of pelvic limb function were identified, and a numeric scoring system was devised to reflect that recovery. In phase 2, pelvic limb gait was scored by different observers, using a numeric and a visual analog scale. Intra- and interobserver coefficients of variability of both methods were compared. In phase 3, pelvic limb function was scored, using the numeric scale at various intervals after acute thoracolumbar disk herniations. RESULTS: The numeric scale was significantly more reliable than the visual analog scale when both intra- and interobserver coefficients of variability were evaluated. Dogs that were paraplegic with no deep pain sensation recovered at different rates during the first 3 months, whereas dogs that were paraplegic with deep pain sensation typically recovered within 1 month of injury. CONCLUSIONS: Pelvic limb gait of dogs recovering from thoracolumbar spinal cord injuries can be reliably quantified, using a numeric scale. This scale will facilitate the performance of clinical trials aimed at improving the outcome of acute spinal cord injuries.

Animals↗

PubMed1999

Chronic and acute compressive spinal cord lesions in dogs due to intervertebral disc herniation are associated with elevation in lumbar cerebrospinal fluid glutamate concentration.

Acute injury to the central nervous system initiates a series of biochemical events that cause secondary tissue damage. The accumulation of excessive concentrations of glutamate in the extracellular space causes excitotoxic damage, and is incriminated as a mediator of this secondary tissue damage. The aim of this study was to measure the concentration of glutamate in cerebrospinal fluid (CSF) obtained from the cerebellomedullary cistern and lumbar subarachnoid space in dogs with acute and chronic compressive injuries of the cervical and thoracolumbar spinal cord, and to correlate the glutamate concentration with injury severity. The results demonstrate that focal injuries of the spinal cord do not affect the glutamate concentration in CSF taken from the cerebellomedullary cistern. However, dogs with severe, acute thoracolumbar disc herniations have two- to 10-fold increases in glutamate concentration in their lumbar CSF at intervals of >12 h after injury. Moreover, the severity of their clinical signs is directly related to the glutamate concentration. Dogs with chronic compressive thoracolumbar lesions have a two-fold elevation of CSF glutamate concentration, suggesting that excitotoxicity may also be a component of chronic spinal cord compression.

Acute Disease↗

PubMed1998

Prognostic factors for dogs with granulomatous meningoencephalomyelitis: 42 cases (1982-1996).

OBJECTIVE: To assess signalment, clinical signs, results of CSF analysis, treatment, and survival times in dogs with granulomatous meningoencephalomyelitis (GME) and to identify factors associated with survival. DESIGN: Retrospective study. SAMPLE POPULATION: Medical records of 42 dogs with GME. PROCEDURE: Information on signalment, neurolocalization, presence of focal or multifocal signs, results of CSF analysis, method of treatment, and time from onset of clinical signs to death was retrieved from medical records of each dog. Kaplan-Meier survival analysis was used to assess survival times. The Cox proportional hazards method was used to identify predictors of survival. RESULTS: Females and toy and terrier breeds were predisposed to GME. Half of the dogs had focal neurologic signs, and half had multifocal involvement. Clinical signs referable to the forebrain were most common with focal involvement, whereas signs referable to the forebrain and brainstem were most commonly seen with multifocal involvement. Cerebrospinal fluid analysis commonly revealed a mononuclear pleocytosis. Survival times ranged from 1 to > 1,215 days. Significant differences in survival times were demonstrated for the following factors: focal versus multifocal clinical signs, neurolocalization of focal signs, and treatment with radiation. Radiation was the only independent predictor of survival. CLINICAL IMPLICATIONS: Dogs with signs suggesting focal involvement of GME tend to survive longer than those with multifocal involvement. Radiation is an effective treatment for dogs with GME, particularly those with clinical signs suggesting focal involvement.

Animals↗

PubMed1997

Factor X deficiency in a cat.

Severe congenital deficiency of factor X was diagnosed in a 3-year-old castrated male domestic shorthair cat with clinical signs of generalized seizures and prolonged bleeding after venipuncture. Heritability of factor X deficiency was suspected because of a prolonged Russell's viper venom time in the dam and reductions in factor X activity in the dam and 1 sibling. To our knowledge, factor X deficiency in cats has not been reported previously. Definitive diagnosis for animals with clinical signs of coagulopathy may require repetition of coagulation screening tests using different assay methods or specific coagulation factor analyses.

Animals↗

PubMed1996

Encephalitis and meningitis.

Inflammation of the brain and meninges is a common cause of neurologic dysfunction in dogs and cats. A wide range of infectious agents has been demonstrated to cause encephalitis an meningitis, although there are many inflammatory conditions for which an etiology has not been found. Analysis of cerebrospinal fluid is the most useful diagnostic test to identify central nervous system inflammation. This article discusses the common causes of encephalitis and meningitis in dogs and cats, focusing on clinical presentation, diagnostic findings, treatment modalities, and prognosis.

Animals↗

PubMed1995

Long-term complications of diabetes mellitus, Part I: Retinopathy, nephropathy, neuropathy.

Diabetic retinopathy, nephropathy, and neuropathy occur infrequently in small animals, but are capable of causing significant disease. The clinical and histopathologic findings seen with these late complications of diabetes are discussed. The pathogenesis of these disorders is most likely multifactorial; metabolic alterations secondary to the hyperglycemic state, and microvascular changes seen with diabetes have both been implicated. Current treatment consists of aggressive control of the hyperglycemia, as research continues into the pathology of the late complications in attempts to find a definitive therapy.

Animals↗

PubMed1994

Toxoplasma gondii-specific antibodies in the aqueous humor of cats with toxoplasmosis.

We decided to determine whether Toxoplasma gondii-specific IgM or IgG is produced locally or is deposited in the aqueous humor of T gondii-naive cats after primary or secondary inoculation with T gondii. Cats were orally inoculated with T gondii tissue cysts during weeks 0 and 36. Aqueous humor and serum T gondii-specific IgM and IgG were measured, using ELISA, during weeks 0, 2, 4, 6, 8, 12, 16, 20, 26, 34, 38, 40, 42, 44, 48, 56, 62, 66, and 72 after primary oral inoculation. Total immunoglobulin-based Goldmann-Witmer coefficients were calculated to verify intraocular antibody production. Toxoplasma gondii-specific IgM was not detected in the aqueous humor of any cat. Data indicate that cats have transient local production of T gondii-specific IgG in the aqueous humor after primary and secondary oral inoculations with T gondii tissue cysts. The intraocular immune response to systemic T gondii infection may signal ocular recruitment of antigen-specific lymphocytes that function independently from the general humoral response to T gondii infection. Cautious interpretation of results that suggest intraocular production of T gondii-specific IgG in cats with uveitis is warranted.

Animals↗

PubMedDate not supplied

The computed tomographic appearance of acute thoracolumbar intervertebral disc herniations in dogs.

The appearance of herniated intervertebral disc material in the thoracolumbar vertebral canal was evaluated in 23 dogs using computed tomography (CT). The images were then compared with the myelographic and surgical findings. The normal spinal cord, outlined by epidural fat over intervertebral disc spaces, was of intermediate attenuation on transverse CT images. Herniated disc material was identified in all animals as a heterogeneous hyperattenuating extradural mass. The attenuation of the disc material increased with the degree of mineralization. In seven dogs, the herniated material was only slightly more attenuating than the spinal cord. In these dogs, small fragments of mineralized disc material and significant hemorrhage were found in the epidural space at surgery. In dogs with a long standing history of disc herniations, disc material identified in the vertebral canal had a more hyperattenuating and homogeneous appearance than recently herniated disc material. We conclude that mineralized, herniated disc material and hemorrhage can be identified quickly and safely in dogs using CT.

Animals↗

PubMedDate not supplied

Neurological manifestations of Niemann-Pick disease type C in cats.

Seven Domestic shorthair cats with a lysosomal storage disorder analogous to human Niemann-Pick disease type C, from a breeding colony were studied to characterize the neurological manifestations of this disorder. Affected cats were identified by means of liver biopsies at 4 to 6 weeks of age. Neurological examinations were performed at 2 week intervals from the onset of clinical signs. All cats displayed signs referrable to the cerebellum, with a subtle intention tremor noticed initially at 8 to 12 weeks of age; the disease was rapidly progressive. The tremor became more pronounced, menace response was lost, and severe dysmetria and ataxia developed. Three cats also had signs referrable to other areas of the central nervous system. Cats died or were euthanized between 12 and 43 weeks of age. Pathological findings included accumulation of substrate within neurons throughout the central nervous system, and axonal spheroid formation. The clinical and pathological findings in these cats are comparable to those in the human form of the disease.

Animals↗

PubMedDate not supplied

Intervertebral disk disease in 10 cats.

The medical records of 10 cats diagnosed with intervertebral disk disease were reviewed. No apparent sex or breed predilection was found. The mean age of cats in the study was 9.8 years. Clinical signs included back pain, difficulty ambulating, and incontinence. Radiographs revealed narrowed disk spaces, mineralized intervertebral disks, and evidence of extradural compression on myelography or computed tomography. All intervertebral disk herniations occurred in the thoracolumbar spine, with a peak incidence at the fourth to fifth lumbar (L4-L5) intervertebral disk space. Eight cats had Hansen's type I intervertebral disk herniation. Surgery was performed in seven cats. All cats judged to have an excellent outcome had undergone surgical decompression.

Animals↗