Search PubMed⌕ Search

Biomedical subjects

L Marchand

Publications and source records attributed to L Marchand.

36 records · Page 2Linked to original sources
PubMed1986

A reproducible radionuclide procedure for measurement of cerebrospinal fluid shunt flow.

A radionuclide technique was developed to obtain reproducible measurements of cerebrospinal fluid flow in Rickham-Holter type shunt systems. In attempting to reproduce previously described radionuclide procedures, we found that different flow rate measurements can be obtained simply by changing the radiotracer injection technique or the method of analysis of the time activity curves which are generated. The importance of these technical pitfalls cannot be over-emphasized, since there is no gold standard to evaluate cerebrospinal fluid flow in vivo. An experimental model with a calibrated Harvard pump and a shunt system filled with normal saline was constructed. Aliquots of 500 microCi of pertechnetate in 0.05 ml of saline were injected serially into the center of Rickham reservoir using a size 28 needle. Time-activity curves were obtained after waiting five min to reach equilibrium, and standard curves of radiotracer clearance vs actual flow for each system used clinically in our institution were generated. In addition, a technique to quantify and thus correct for the small but significant leak of radiotracer which occurs at the site of injection in the reservoir is described. Excellent correlation was obtained between our results and the clinical and radiological findings in a preliminary clinical evaluation.

Cerebrospinal Fluid↗
PubMed1980

Sensory neuropathy associated with primary biliary cirrhosis. Histologic and morphometric studies.

Sensory symptoms can develop in the course of primary biliary cirrhosis. They have been attributed to xanthomatous infiltrates of the nerves. We report a case of a young woman suffering from pure sensory neuropathy starting at a time when evidence of liver disease was minimal. Histologic and morphometric studies of sural nerve biopsy specimens obtained from calf and ankle showed a dying-back type of axonal degeneration predominantly affecting large myelinated fibers. No lipid-containing cells were seen, which raises the possibility that other mechanisms related to primary biliary cirrhosis are involved in the pathogenesis of the neuropathy.

Adult↗
PubMed1980

Neuropathy and mitochondrial myopathy.

It has been stated that peripheral neuropathy can be a feature of so-called ophthalmoplegia-plus syndrome, but to date only one case of hypertrophic neuropathy has been reported. This study is concerned with the clinical, electrophysiological, and pathological observations in a 37-year-old man with progressive external ophthalmoplegia and a ragged-red fiber myopathy associated with severe sensorimotor neuropathy. Histological and morphometric studies of the sural nerve revealed a marked loss of large myelinated fibers and an occasional degenerating axon. Residual fibers had disproportionately thin myelin sheaths in relation to axon calibers. In contrast to the muscle biopsy findings, no mitochondrial paracrystalline inclusions were observed in the nerve. However, the number of mitochondria per square micron of Schwann cell cytoplasm was elevated when compared with values obtained from normal subjects and a patient with a chronic neuropathy. These findings may indicate an alteration of mitochondrial function common to muscle fibers and Schwann cells which, in nerves, could lead to axon loss and abnormality of myelination.

Humans↗
PubMed1977

Parkinsonism--dementia complex, hydrocephalus and Paget's disease.

A 65-year-old female patient with Paget's disease displayed dementia, a bilateral Parkinsonian syndrome, gait ataxia, bilateral grasp reflex of the feet, urinary incontinence and a left hemicerebellar syndrome. She had a marked basilar impression; the radionuclide cisternogram was suggestive of a communicating hydrocephalus with ventricular dilatation. After a shunting procedure there was improvement in both neurological and mental function.

Aged↗
PubMedDate not supplied

Behavioral and biochemical effects of L-tryptophan and buspirone in a model of cerebellar atrophy.

The Lurcher mutant mouse can be considered an adequate model of autosomal dominant spinocerebellar atrophy because of the severe degeneration of its cerebellar cortex and inferior olive. The purpose of this study was to determine whether the motor coordination deficits of Lurcher mutants could be improved after chronic administration of the serotonin (5-hydroxytryptamine; 5-HT) precursor, L-tryptophan, or of the 5-HT(1A) agonist, buspirone. During these treatments, the mice were submitted to behavioral evaluations using the coat hanger and the rotorod tests, as well as an inclined screen and a vertical grid test. At the end of treatments, 5-HT and 5-hydroxindole-3-acetic acid (5-HIAA) were measured in six brain regions. On the coat hanger test, administration of L-tryptophan accelerated movements along the horizontal bar by 44%, while buspirone increased the time spent on the apparatus by 11%. Neither drug had an effect on climbing ability or on the time spent on a rotating beam. Administration of L-tryptophan increased 5-HIAA levels in frontal cortex, neostriatum, thalamus, brainstem, cerebellum and spinal cord, but elevated 5-HT only in neostriatum, brainstem and cerebellum. In contrast, buspirone led to 5-HT increases in cerebellum and augmented 5-HIAA in the spinal cord. The modest test-specific improvements are consistent with some of the clinical data concerning 5-HT pharmacotherapy in patients suffering from cerebellar atrophy.

Animals↗
PubMedDate not supplied

The evolution of a unit for the cognitively impaired elderly.

The MDE unit has filled a significant gap in the care of the psychogeriatric patient. Prior to its existence, the aggressive demented patient was generally managed by physical or chemical restraints. As community needs increase and require changes in the type of institutional care provided, the program will continue to respond with adaptive programs and expanded staff expertise. In the future the program may play a larger role. Due to gaps in the health care system, this type of program may have to admit more psychogeriatric patients. Also, this unique patient population could provide material for scientific research on dementia and its treatment. The MDE program depends not only on physicians and medications but also on a dedicated interdisciplinary team to manage this interesting and exceptional population.

Aged↗