PubMed Health⌕ Search

Biomedical subjects

K G Braund

Publications and source records attributed to K G Braund.

At least 19 recordsLinked to original sources
PubMed2006

Laryngeal paralysis-polyneuropathy complex in young related Pyrenean mountain dogs.

OBJECTIVES: To characterise clinical, electrophysiological and histopathological findings. To analyse pedigree information in six young related Pyrenean mountain dogs with laryngeal paralysis-polyneuropathy complex (LP-PNC). METHODS: A retrospective study of clinical records and pedigrees of six young related Pyrenean mountain dogs with LP-PNC was carried out. RESULTS: All dogs were presented with laryngeal paralysis and concurrent megaoesophagus. Electrodiagnostic testing was performed in three dogs and showed electrophysiological abnormalities in the distal appendicular muscles. Histopathological findings of peripheral nerve samples were dominated by distal axonal degeneration. Clinical, electrophysiological and histopathological findings were supportive of a diagnosis of degenerative, sensorimotor LP-PNC, similar to that reported in young dalmatians and rottweilers. All dogs died or were euthanased by two years of age. An autosomal recessive mode of inheritance was suspected based on pedigree analysis. CLINICAL SIGNIFICANCE: Congenital LP-PNC should be suspected in any young dog presenting with laryngeal dysfunction and other concurrent neurological abnormalities. The prognosis is usually poor.

Animals↗
PubMed2005

Sensory neuropathy in two Border collie puppies.

A peripheral sensory neuropathy was diagnosed in two Border collie puppies. Neurological, electrophysiological and histopathological examinations suggested a purely sensory neuropathy with mainly distal involvement. Urinary incontinence was observed in one of the puppies and histological examination of the vagus nerve revealed degenerative changes. An inherited disorder was suspected.

Animals↗
PubMed2002

Genetic aspects of Labrador Retriever myopathy.

Labrador Retriever myopathy (LRM) has become a relatively common muscular disease. The objective of our prospective study was to determine by segregation analyses a plausible mode of inheritance within a Labrador Retriever population. Therefore we performed neurological examinations, as well as electromyographic and histopathological evaluations of 58 closely related dogs. Seven dogs with an average age of 27.8 months had clinical signs consistent with LRM including exercise intolerance or fatigue. The diagnosis was based on neurological deficits and confirmed by histopathological results of muscle biopsy. We found in all cases obvious differences in fiber calibre size associated with texture disturbances. In addition, we found 41 clinically normal dogs with histological findings consistent with LRM. Three genetic models, the major gene, the mixed inheritance as well as the environmental model, were evaluated by segregation analyses. They were applied to an extended pedigree including 164 non-randomly ascertained related Labradors. According to phenotype the clinically examined dogs were divided into two different data sets. One data set distinguished between clinically normal and abnormal dogs, the second data set between histopathologically normal and abnormal dogs. We concluded that the clinical form of LRM is transmitted by a major gene and controlled by an autosomal recessive mode of inheritance. Furthermore, for expression of the subclinical form an additional gene or an environmental factor is responsible. Our findings suggest that LRM is similar to limb-girdle muscular dystrophy in man and therefore, may be used in the future as an animal model.

Animals↗
PubMed2001

Histopathology, electrodiagnostic testing, and magnetic resonance imaging show significant peripheral and central nervous system myelin abnormalities in the cat model of alpha-mannosidosis.

Alpha-mannosidosis is a disease caused by the deficient activity of alpha-mannosidase, a lysosomal hydrolase involved in the degradation of glycoproteins. The disease is characterized by the accumulation of mannose-rich oligosaccharides within lysosomes. The purpose of this study was to characterize the peripheral nervous system (PNS) and central nervous system (CNS) myelin abnormalities in cats from a breeding colony with a uniform mutation in the gene encoding alpha-mannosidase. Three affected cats and 3 normal cats from 2 litters were examined weekly from 4 to 18 wk of age. Progressively worsening neurological signs developed in affected cats that included tremors, loss of balance, and nystagmus. In the PNS, affected cats showed slow motor nerve conduction velocity and increased F-wave latency. Single nerve fiber teasing revealed significant demyelination/remyelination in affected cats. Mean G-ratios of nerves showed a significant increase in affected cats compared to normal cats. Magnetic resonance imaging of the CNS revealed diffuse white matter signal abnormalities throughout the brain of affected cats. Quantitative magnetization transfer imaging showed a 8%-16% decrease in the magnetization transfer ratio in brain white matter of affected cats compared to normal cats, consistent with myelin abnormalities. Histology confirmed myelin loss throughout the cerebrum and cerebellum. Thus, histology, electrodiagnostic testing, and magnetic resonance imaging identified significant myelination abnormalities in both the PNS and CNS that have not been described previously in alpha-mannosidosis.

Animals↗
PubMed1999

Ultrastructural protein zero expression in Charcot-Marie-Tooth type 1B disease.

Charcot-Marie-Tooth type 1B (CMT 1B) disease, an inherited demyelinating peripheral neuropathy, results from different point mutations located in the P0 gene on chromosome 1 q21-23. We have quantified, at the ultrastructural level, the immunocytochemical expression of the P0 protein in two unrelated CMT 1B patients with mutations (Ser 78 to Leu and Asn 122 to Ser) located in two different exons in the extracellular domain of the protein. A twofold decrease in P0 expression was observed in compact myelin in each case, compared with age-matched controls. The severity of the phenotypes showed no direct relationship to the levels of P0 protein expression in these 2 patients.

Amino Acid Substitution↗
PubMed1997

Treatment of a dog with an insulinoma-related peripheral polyneuropathy with corticosteroids.

A crossbreed dog with a history of a chronic progressive tetraparesis had an insulinoma-related peripheral polyneuropathy. Frequent feeding and treatment with corticosteroids resulted in recovery from a non-ambulatory to an almost completely normal clinical state, despite the persistence of hypoglycaemia and hyperinsulinism. After euthanasia for uncontrollable seizures, the presence of a beta-cell carcinoma of the pancreas and extensive axonal degeneration of the peripheral nerves was confirmed by histopathological examination. These findings may indicate an immune-mediated pathogenesis for insulinoma-related peripheral polyneuropathy.

Animals↗
PubMed1997

Profile of electrodiagnostic abnormalities in cats with GM1 gangliosidosis.

OBJECTIVE: To determine which electrodiagnostic tests yield abnormal findings in cats with GM1 gangliosidosis, and to determine the approximate age of onset of electrodiagnostic abnormalities. ANIMALS: Cats (28 to 335 days old) affected with GM1 gangliosidosis (n = 11) and unaffected controls (n = 14). PROCEDURE: Cats were grouped by age: group 1, < or = 90 days, group 2, 91 to 200 days; and group 3, > 200 days. Electrodiagnostic tests were conducted, including needle electromyography, motor and sensory nerve conduction velocity, spinal evoked potentials, and brainstem auditory evoked potentials. Results for control and affected cats were compared, using the general linear model for ANOVA and Scheffé's test for multiple comparisons. RESULTS: Needle electromyography did not reveal abnormal spontaneous activity in skeletal muscles of any cat; furthermore, statistical analysis did not indicate significant difference between affected and control groups for nerve conduction velocity, confirming that degeneration of peripheral nerve fibers is not a feature of this disease. However, spinal evoked potentials were abnormal in group-3 cats; conduction velocity within sensory pathways in the cranial part of the spinal cord was significantly slower in GM1-affected cats (P = 0.0002). Brainstem auditory evoked responses also were abnormal: wave V (generated in the region of the pons) had prolonged latency in cats of groups 2 and 3 (P = 0.0003 and 0.0001, respectively, at 90 decibels sound pressure level). In the oldest cats, latencies for earlier waves within the auditory pathway also were prolonged; wave I (generated by the cochlear nerve) was prolonged in group-3 cats (P = 0.0423). CONCLUSIONS: Motor and sensory nerve conduction velocities remained within normal limits in GM1-affected cats. However, spinal evoked potentials indicated slowing in conduction velocity along the cranial part of the spinal cord in group 3 cats. Brainstem auditory evoked responses indicated prolonged latencies in cats of groups 2 and 3.

Animals↗
PubMed1996

Chronic inflammatory demyelinating polyneuropathy in dogs and cats.

Over the past several years, we have accumulated data on a spontaneous demyelinating peripheral neuropathy that is not well identified in domestic animals. This disorder occurs in dogs and cats of either sex and does not appear breed-related. Onset of signs is usually insidious and the course is typically chronic, sometimes relapsing, and often slowly progressive. Mature animals of any age may be affected. Clinical signs include tetraparesis, sometimes progressing to tetraplegia, stumbling gait, and hyporeflexia. Motor nerve conduction velocities are decreased. Pathologically, changes in teased single fibers from peripheral nerves are dominated by multifocal paranodal demyelination. Scattered, thinly myelinated fibers are seen on semithin sections. Ultrastructural studies reveal macrophages within myelinated fibers stripping the myelin sheaths, naked and remyelinating axons, and focal/multifocal endoneurial mononuclear cells. Indirect immunofluorescence revealed positive IgG staining in peripheral nerve myelin sheaths from two dogs. The course of the disease, clinical signs, electrophysiology, and pathology have similarities to chronic inflammatory demyelinating polyneuropathy in people.

Age Factors↗
PubMed1995

Histochemical and morphometric study of fiber types in ten skeletal muscles of healthy young adult cats.

A histochemical and morphometric study of fiber types in a variety of skeletal muscles of healthy young adult cats was undertaken to provide normative data not available previously. Using a standardized system of nomenclature, fiber types 1, 2A, 2B, and 2C were identified in most cat muscles on the basis of myosin ATPase staining at pH 4.45. Type-2M fibers were present in temporalis (TEM) and masseter (MAS) muscles. Type-1 fibers predominated in medial head of triceps (MHT) and soleus muscles. Type-2B fibers were dominant in biceps femoris, lateral head of gastrocnemius cranial tibial, long head of triceps, and superficial digital flexor muscles; type-2A fibers were dominant in buccinator muscle samples; and type-2M fibers were dominant in TEM and MAS muscles. Numbers of type-2C fibers did not exceed 2 to 3% of the myofiber population in any muscle. In CT and LHT muscles, a gradient of fiber type distribution was observed, with significant (P < 0.05) increase in numbers of type-1 and type-2A fibers in deeper regions of the muscles. The distribution of fiber types was compartmentalized in MHT and MAS specimens. Diameter of type-2B fibers was significantly (P < 0.05) larger than that of type-1 and type-2A fibers in biceps femoris, lateral head of gastrocnemius, cranial tibial, long head of triceps, and superficial MHT muscles. Diameter of type-2M fibers was significantly (P < 0.05) larger than that of type-1 fibers in TEM and MAS muscles. The soleus type-1 muscle fibers were the largest fibers encountered in any muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1994

Concomitant brainstem axonal dystrophy and necrotizing myopathy in vitamin E-deficient rats.

The purpose of this study was to simultaneously evaluate in rats the effects of vitamin E depletion on tissue alpha-tocopherol (alpha-T) concentrations, electrophysiologic measurements and histopathology. Rats (21-day-old male Wistar) were fed either vitamin E-deficient or supplemented (control) diets (n = 6/group) for 10, 16, and 61 weeks. At these times, electrophysiologic tests (electromyography, spinal and somatosensory evoked potentials, and motor nerve conduction velocity) were performed, the rats were killed and alpha-T concentrations of adipose tissue, sciatic nerve, and cervical and lumbar spinal cord were measured along with histopathologic evaluation of skeletal muscles and the nervous system. By 61 weeks, depletion of alpha-T from adipose tissue and peripheral nerve was more severe (< 1% of controls) than from cervical and lumbar spinal cord (15 and 8% of controls, respectively). Electrophysiologic tests were normal at all times. Histopathologic evaluation at 61 weeks revealed normal peripheral nerve structure, but necrosis of type 1 muscle fibers and increased numbers of spheroids in the gracile and cuneate nuclei. Our results confirm that low alpha-T concentrations in tissues precede histologic changes in peripheral nerves and skeletal muscle. Furthermore, pathologic changes associated with vitamin E deficiency occur independently in muscle and nervous tissue of rats.

Adipose Tissue↗
PubMed1994

Distal sensorimotor polyneuropathy in mature Rottweiler dogs.

A polyneuropathy recognized in mature Rottweiler dogs is characterized by paraparesis that progresses to tetraparesis, spinal hyporeflexia and hypotonia, and appendicular muscle atrophy. Although signs may appear acutely, the course tends to be gradually progressive (up to 12 months or longer in some dogs) and may be relapsing. Nerve and muscle biopsies were examined from eight affected Rottweilers (six male and two female) between ages 1.5 and 4 years. Pronounced neurogenic atrophy was present in skeletal muscle samples. Changes in sensory and motor peripheral nerves included loss of myelinated nerve fibers, axonal necrosis, and variable numbers of fibers with inappropriately thin myelin sheaths. Ultrastructural findings included myelinated fibers showing myelinoaxonal necrosis, demyelinated fibers often associated with macrophage infiltration, many axons with myelin-like membranous profiles, increased endoneurial collagen, occasional axonal atrophy, and numerous Büngner bands. Lesions in unmyelinated fibers included increased numbers of Schwann cell profiles and loss of axons in Schwann cell subunits. Morphologic and morphometric studies indicated preferential loss of medium (5.5-8 microns) and large (8.5-12.5 microns) fibers, which was more severe in distal parts of nerves than in more proximal regions and nerve roots. The cause was not determined; however, histopathologic studies suggest this condition is a dying-back distal sensorimotor polyneuropathy that has morphologic and morphometric similarities to hereditary motor and sensory neuropathy (HMSN) type II in humans.

Animals↗
PubMed1994

Laryngeal paralysis-polyneuropathy complex in young Dalmatians.

Clinical, morphologic, and morphometric findings are reported in 14 young Dalmatians with laryngeal paralysis. Neurologic signs, including megaesophagus, were observed in 13 of 14 dogs. Electromyographic abnormalities included fibrillation potentials and positive sharp waves in laryngeal, esophageal, facial, and distal appendicular muscles. Neurogenic atrophy was detected in intrinsic laryngeal and appendicular skeletal muscles. A diffuse, generalized polyneuropathy, dominated by axonal degeneration, was observed in recurrent laryngeal and appendicular peripheral nerves. Results of quantitative studies, using single teased fiber and cross-sectional nerve preparations, indicated that changes were more severe in distal parts of peripheral nerves, with preferential loss of medium sized (5.5 to 8 microns) and large-caliber (8.5 to 12 microns) myelinated nerve fibers. Ultrastructural alterations were observed in myelinated and unmyelinated nerve fibers. The term laryngeal paralysis-polyneuropathy complex is proposed for this apparent dying-back disorder, which is clinically, electrophysiologically, and pathologically different from laryngeal paralysis in young Bouvier des Flandres and Siberian Huskies. Prognosis for Dalmatians with laryngeal paralysis-polyneuropathy complex is guarded to poor. The condition is believed to be inherited.

Animals↗
PubMed1993

Potassium concentrations in muscle, plasma and erythrocytes and urinary fractional excretion in normal horses and those with chronic intermittent exercise-associated rhabdomyolysis.

Potassium concentrations were measured in semimembranosus muscle, plasma and erythrocytes, and the urinary fractional excretion determined in normal horses and those that had chronic intermittent exercise-associated rhabdomyolysis. Muscle from the rhabdomyolysis horses was also evaluated microscopically. The horses with rhabdomyolysis had a lower muscle potassium concentration on a dry weight basis. Although the wet weight potassium content was also lower, the difference was not significant. Urinary fractional excretion of potassium (and also sodium and chloride) did not differ significantly between the two groups although the rhabdomyolysis group had a lower percentage excretion of potassium. Erythrocyte potassium concentration was similar for both groups. Low grade to moderate degenerative myopathy or absence of lesions was seen on microscopic sections of muscle from horses with rhabdomyolysis; only one had a vacuolar myopathy and potassium content was not determined. These results suggest that altered muscle potassium content may be a factor in rhabdomyolysis.

Animals↗