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Biomedical subjects

J Shankroff

Publications and source records attributed to J Shankroff.

5 recordsLinked to original sources

Effect of erucic acid on platelets in patients with adrenoleukodystrophy.

In a clinical trial for the management of adrenoleukodystrophy, we analyzed the effect of erucic acid (a component of Lorenzo's oil) on platelet number, fatty acid composition, and function. Analysis of variance was performed to compare platelet counts before starting treatment with Lorenzo's oil and at 6 and 12 months. We measured platelet fatty acid composition in subjects and control patients and correlated these values with their platelet counts using discriminant analysis. After 6 months, the mean platelet count decreased from 247,000/mm3 to 169,000/mm3 (+/- 1 standard deviation 58,000,n =39), P < 0.0001 compared to 18 subjects on a control diet having a mean baseline platelet count of 259,000/mm3 (+/- 1 standard deviation 67,000, n = 19) and at 6 months 267,000/mm3 (+/- 1 standard deviation 71,000). We found at P < 0.05 that the platelet counts showed a strong inverse relationship with erucic acid levels and other omega 9 fatty acids that form from the administration of the erucic acid component of Lorenzo's oil. Morphologic and platelet sizing measurements suggest that the physical properties of platelets may also be affected by erucic acid. Our studies show that the ingestion of erucic acid affects platelet biology. This indicates that platelet counts and properties are influenced by monounsaturated fatty acids, in addition to the well-known effects of polyunsaturated fatty acids. In areas of the world where erucic acid is widely ingested, the biology of platelets in these populations may be affected.

Adrenoleukodystrophy

Visual system abnormalities in adrenomyeloneuropathy.

We studied the visual system in 59 men with adrenomyeloneuropathy. Pattern-reversal visual evoked potentials, magnetic resonance imaging, and clinical examination revealed that visual pathways are affected in 63% of patients, involving the optic discs, optic nerves, lateral geniculate bodies, optic radiations, and parietooccipital cortex. This indicates both primary demyelination of the optic nerves and discs, and more diffuse involvement of postchiasmal structures.

Adrenoleukodystrophy

Elevated plasma adrenocorticotropin concentration as evidence of limited adrenocortical reserve in patients with adrenomyeloneuropathy.

Adrenal insufficiency occurs in approximately two thirds of patients with adrenomyeloneuropathy. Its development may precede or follow the onset of neurological disease. To define the sensitivity of various tests of adrenal cortical function, we reviewed adrenocortical function tests in 28 patients with adrenomyeloneuropathy who had normal ACTH stimulation tests at the time of enrollment into an ongoing dietary study. Endocrine studies performed at 6-month intervals included a conventional ACTH stimulation test, plasma ACTH and cortisol concentrations, and 24-h urinary cortisol and aldosterone excretion rates. Eleven patients (39%) developed an elevated plasma ACTH concentration after a median follow-up of 3 yr. Their 24-h urinary cortisol and plasma basal and ACTH-stimulated cortisol concentrations were all normal. The mean basal cortisol level tended to be lower in patients who had increased plasma ACTH levels than in patients who maintained a normal plasma ACTH concentration during the study period (408 +/- 22 vs. 491 +/- 33 nmol/L; P = 0.05). Patients who had an increased plasma ACTH concentration and symptoms consistent with adrenal insufficiency had a lower mean 24-h urinary free cortisol level than those with normal plasma ACTH (196 +/- 22 vs. 281 +/- 30 nmol/day; P < 0.05). Plasma ACTH concentrations were persistently elevated in six patients in whom subsequent values were available. One individual later developed a subnormal ACTH-stimulated cortisol concentration consistent with overt adrenal insufficiency. Our results suggest that conventional provocative and integrative tests of adrenocortical function may not be sufficient to identify patients with adrenomyeloneuropathy who have compensated adrenal hypofunction. An elevated plasma ACTH concentration may represent an early marker for adrenocortical dysfunction and incipient adrenal insufficiency in AMN patients.

Adrenal Cortex

Visual evoked potentials in adrenoleukodystrophy: a trial with glycerol trioleate and Lorenzo oil.

Adrenoleukodystrophy is an X-linked metabolic disorder with very-long-chain fatty acid (VLCFA) accumulation and multifocal nervous system demyelination, often with early involvement of visual pathways. Dietary therapy with glycerol trioleate and glycerol trierucate (Lorenzo oil) diminishes VLCFA levels. In a study of patients with the adrenomyeloneuropathy phenotype of adrenoleukodystrophy, we used pattern-reversal visual evoked potentials to evaluate visual pathways before and after treatment. Of 108 patients tested, all 26 women and 68 of the 82 men had normal potentials at baseline. Seventy patients were retested at 1 year, at which time VLCFA levels were markedly diminished. Of them, the responses in the 10 men who showed abnormalities at baseline remained abnormal; the latencies in 4 men with initially normal responses became abnormal. No patients improved. There were no correlations between disease duration prior to treatment, baseline P100 latencies, VLCFA levels, or the change in P100 latencies and VLCFA levels after dietary treatment for 1 year. Pattern-reversal visual evoked potentials were abnormal in 17% of the men with adrenoleukodystrophy, and there was no evidence that reduction of VLCFA levels improved or retarded visual pathway demyelination.

Adolescent

Adrenoleukodystrophy: phenotypic variability and implications for therapy.

X-linked adrenoleukodystrophy (ALD) is a relatively common disorder that shows a great deal of phenotypic variability. Approximately half of the patients have the rapidly progressive childhood cerebral form that is associated with an inflammatory response in brain and leads to total disability or death during the first decade. Twenty five per cent or more of the patients have adrenomyeloneuropathy (AMN), a form that progresses slowly, involves the spinal cord mainly, shows little or no inflammatory response, manifests in adulthood, and is compatible with a near-normal life span. The two forms of the disease occur frequently within the same kindreds and nuclear families. Segregation analysis based on 3862 individuals in 89 kindreds points to the existence of an autosomal modifier locus with a likelihood ratio of 20:1. In addition, we present preliminary results of three types of therapy. Two hundred and four patients have received a dietary regimen that combines the administration of oils containing mono-unsaturated fatty acids (oleic and erucic) with the restricted intake of very long-chain fatty acids. This regimen normalizes the levels of satured very long-chain fatty acids in plasma within 4 weeks. It appears to improve peripheral nerve function in patients with AMN, and a large-scale trial is in progress to determine whether it can prevent the onset of neurological involvement in patients who have the biochemical abnormality of ALD but are neurologically intact. We report early results of bone marrow transplantation in 14 patients. There is encouraging but still preliminary evidence that transplantation can arrest the progression of the disease in patients with mild neurological involvement. There is urgent need to develop methods to combat the rapid progression of the cerebral forms of the disease, which so far has resisted therapeutic intervention, including immunosuppression or the administration of immunoglobulin.

Adolescent