Biomedical subjects

T L Walker

Publications and source records attributed to T L Walker.

39 records · Page 3Linked to original sources

PubMedDate not supplied

Effect of surgery on the nontreated hip in severe cerebral palsy.

We studied the fate of the nonoperated hip in 35 patients with cerebral palsy who underwent surgical stabilization for unilateral hip subluxation (24 patients) or dislocation (11 patients). Review of medical records and radiographs was performed and analysis was accomplished on the effect of preoperative and radiographic variables on the radiographic outcome of the nonoperated hip. The average age at surgery was 5.5 years and at follow-up was 9.7 years, with an average follow-up of 4.2 years. Before subsequent surgery (in 15 nonoperated hips) or at follow-up, 10 of the nonoperated hips were dislocated and 16 hips were subluxated. Hips were stable and less likely to have surgery if they had a lower initial migration index and higher center edge angles. We conclude that there are few indications for unilateral hip surgery in patients with diplegia or quadriplegia undergoing initial hip stabilization surgery, especially if any degree of dysplasia is present.

Adolescent↗

PubMedDate not supplied

Juvenile-onset distal myopathy in Rottweiler dogs.

Two juvenile Rottweiler siblings were presented with the complaint of decreased activity and various postural abnormalities, including plantigrade and palmigrade stance and splayed forepaw digits. The neurologic examinations were otherwise normal. Electromyography revealed rare fibrillation potentials and positive sharp waves. Motor nerve conduction velocities were normal, whereas compound muscle action potentials from the interosseous muscles were decreased. These findings were consistent with a primary myopathy. A 3rd pup from a different litter and a 4th pup from a litter with 3 of 8 affected dogs had similar clinical presentations. Histopathologic changes in fresh-frozen muscle biopsy samples were similar in all pups and consisted of myofiber atrophy with mild myonecrosis, endomysial fibrosis and replacement of muscle with fatty tissue. These changes were more severe in distal muscles than in proximal muscles. Plasma carnitine concentrations (total and free) were decreased in all pups. Muscle carnitine concentrations (total and free) were decreased in 3 of 4 pups and the least affected pup had a borderline low free muscle carnitine concentration. Abnormalities involving major metabolic pathways were not found on quantification of organic and amino acids. Dystrophin immunocytochemistry was normal in 2 dogs tested. Distal myopathies in humans are classified under the dystrophic group of muscle disorders. These 4 cases represent a form of muscular dystrophy apparently not previously reported in dogs.

Adenosine Triphosphatases↗

PubMedDate not supplied

Enhanced in vivo tumour response from combination of carboplatin and low-dose c-myc antisense oligonucleotides.

BACKGROUND: Phosphorothioate oligonucleotides ([S]ODNs) contain a modified phosphate backbone. Antisense [S]ODNs targeted to specific oncogenes have been used to varying success in vivo. Carboplatin is a commonly used chemotherapeutic and is associated with chemoresistance in some human tumours. The potential for combined antisense [S]ODNs and carboplatin chemotherapy has only recently been explored in vivo. MATERIALS AND METHODS: This study examines the effect of c-myc antisense oligomers delivered in isolation as naked DNA and in combination with carboplatin upon the growth kinetics of an in vivo transplantable adenocarcinoma using rodents. RESULTS: Tumours treated with a combination of 600 microg of 15-mer c-myc phosphorothioate antisense oligodeoxyribonucleotide and an intravenous administration of carboplatin (3 mg/kg), demonstrated a significant (p<0.05) retardation in tumour growth kinetics relative to a control. Two mismatch antisense controls did not significantly inhibit tumour growth. C-myc protein studies in tumour sections failed to show significant differences in c-myc expression in any of the treated tumours. CONCLUSION: This study demonstrates that carboplatin affects the relative abundance of c-myc and that combination treatment of carboplatin and c-myc phosphorothioate antisense oligonucleotides in vivo results in synergistic tumour retardation.

Adenocarcinoma↗