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Biomedical subjects

R D Currier

Publications and source records attributed to R D Currier.

At least 19 recordsLinked to original sources

Decreased insulin-like growth factor I-mediated protein tyrosine phosphorylation in human olivopontocerebellar atrophy and lurcher mutant mouse.

We examined insulin-like growth factor I (IGF-I)-dependent phosphorylation and protein tyrosine kinase (PTK) activity in cerebellar cortex of normal humans, patients with olivopontocerebellar atrophy (OPCA) ("C" kindred) and in lurcher mutant mouse, a suggested animal model for OPCA. PTK activity and IGF-I-dependent protein tyrosine phosphorylation was significantly reduced in cerebellar cortex of human OPCA patients as compared to the normal controls. Immunoblot analysis also demonstrated a decrease in cerebellar 80 kDa phosphotyrosine protein in these patients. By autoradiography, IGF-I receptors were localized in the molecular layer of 30-day-old control and lurcher mutant mice cerebella. However, the lurcher mutant mice showed a decrease in [125I]-IGF-I binding in the molecular layer as compared to the littermate controls. The IGF-I receptor autophosphorylation was also markedly reduced in 15-day- and 22-day-old lurcher cerebella. These results suggest that the process of cerebellar degeneration in human OPCA and lurcher mutant mouse may be associated with altered IGF-I receptor binding and protein tyrosine phosphorylation.

Amino Acid Sequence

Familial progressive subcortical gliosis.

We report clinical and pathologic findings from two kindreds afflicted with a familial form of progressive subcortical gliosis. The disorder segregated as an autosomal dominant trait. Onset was in the presenium and the course was slowly progressive. Affected individuals initially manifested personality change, degeneration of social ability, disinhibition, psychotic symptoms, memory impairment, or depression. Later, all developed progressive dementia, frequently associated with verbal stereotypy, decreased speech output, echolalia, or manifestations of the human Klüver-Bucy syndrome. Terminal clinical manifestations included profound dementia, frequently with mutism, dysphagia, and extrapyramidal signs. Autopsy of seven end-stage patients revealed generalized cerebral atrophy, predominantly involving the white matter of the frontal and temporal lobes. Microscopically, prominent fibrillary astrocytosis was present in the subcortical white matter and in the subpial and deep layers of the overlying cerebral cortex. These changes were most pronounced in the frontal and temporal lobes, especially in the cingulate gyri and insulae. Mild cortical neuronal loss accompanied the gliosis, but no myelin loss was evident. The claustra and substantia nigra also showed severe astrocytosis and degenerative changes. Amyloid deposits and neuronal cytoskeletal inclusions were absent.

Aged

Inositol 1,4,5-trisphosphate metabolism in the cerebella of Lurcher mutant mice and patients with olivopontocerebellar atrophy.

We have investigated inositol 1,4,5-trisphosphate (InsP3) metabolism in cerebellar membranes of normal humans and patients with dominant ataxia ('C' kindred), and also in cerebellar microsomes of Lurcher mutant mouse (a suggested model for cerebellar ataxia). Various [3H]InsP3 metabolites formed were separated by HPLC using 3 successive convex gradients of 1.7 M ammonium formate, pH 3.7. [3H]InsP3 metabolism was rapid and in 15- and 45-day-old control mice cerebella about 50% of [3H]InsP3 was metabolized within 20 s. In 15-day-old Lurcher mice the rate of [3H]InsP3 metabolism was significantly low (40% of normal). [3H]InsP3 metabolism was almost absent in 45-day-old Lurcher mice cerebellar microsomes. The decreased [3H]InsP3 metabolism was consistent with decreased recovery of the various inositol polyphosphates formed. Similarly, in cerebellar membranes of human patients with olivopontocerebellar atrophy (OPCA) a significant decrease in [3H]InsP3 metabolism was observed when compared with normal controls. These data suggest that altered phosphoinositide turnover may be associated with the onset of neuronal degeneration in human OPCA.

Animals

Inositol 1,4,5-trisphosphate receptors and protein kinase C in olivopontocerebellar atrophy.

We examined protein kinase C (PKC) activity and inositol 1,4,5-trisphosphate (InsP3) binding in frontal cortex (FC) and cerebellar cortex (CC) of normal humans, patients with dominant ataxia ("C" kindred) and in Lurcher mutant mouse brain (LMB), a suggested animal model for olivopontocerebellar atrophy (OPCA). PKC activity and [3H]InsP3 binding were decreased in CC of human OPCA by 70% and 90% respectively. The decreases were specific to CC as there were no changes in FC. PKC activity and [3H]InsP3 binding in cerebellum (CB) of LMB were similarly decreased as compared to normal littermate controls. The LMB decrease of PKC and [3H]InsP3 binding was evident on the 15th day of age, the day of onset of ataxia. InsP3-mediated calcium release was also decreased significantly in the cerebellar microsomes of 25-day-old LMB and human OPCA when compared with their respective controls. These data indicate that the decrease of second messenger linked PKC activity and InsP3 receptor binding in CB may be a biochemical marker that reflects neuronal degeneration in dominant cerebellar ataxia.

Animals

James Parkinson. On child abuse and other things.

James Parkinson, a general physician, was interested in all facets of medical care, and wrote two books for the lay public that contained comments on diverse things. He may have been one of the first physicians to publicly describe child abuse. Some of his advice to the public was of a neurologic nature, and included directions on the diagnosis and treatment of pseudoseizures, epilepsy, drowning, and stroke.

Child

Familial patterns of prostate cancer: a case-control analysis.

Epidemiological data have not yet enabled physicians to look beyond age and race to identify men at increased risk for prostate cancer. We conducted a hospital-based case-control study of familial patterns of prostate cancer with self-reported data from a risk-factor questionnaire. There were 385 patients with histologically confirmed prostate cancer, and 385 race and age-matched (+/- 5 years) controls with other cancers. Family history, available for 378 patients and 383 controls, was positive for prostate cancer in 13.0% versus 5.7%, respectively. The difference was significant at p = 0.01. The over-all age-adjusted risk estimate for men with a first-degree relative with prostate cancer was significantly elevated (odds ratio of 2.41), as were the individual risk estimates for having a father or brother with prostate cancer (odds ratio of 2.24 and 2.66). Having a second-degree relative (grandfather or uncle) with prostate cancer also conferred elevated but not statistically significant risk. These data accord well with the few previously published case-control studies of familiarity of prostate cancer. On the basis of these findings, one should consider recommending participation in early detection programs for prostate cancer in a man whose father or brother has had the disease.

Age Factors

Morphometric studies in dominant olivopontocerebellar atrophy. Comparison of cell losses with amino acid decreases.

We present a correlation of the morphometric cell density analysis with previous biochemical findings for the inferior olivary nucleus and Purkinje cell layer of the cerebellum from 10 patients (three kindreds) with dominant olivopontocerebellar atrophy. We have analyzed brain amino compounds of these patients and found a decrease of aspartic acid and glutamic acid in the cerebellar cortex and of aspartic acid in the inferior olives. The cell density analysis revealed decreased cell counts, with a mean of 34% of olivary cells and 42% of Purkinje cells surviving when compared with 10 control brains. The cell counts were then correlated with the amino acid analyses. The correlation coefficient for aspartic acid content and surviving neurons in the inferior olive was .87 and that for aspartic acid content and Purkinje cell density was .86. Comparison of glutamic acid content and Purkinje cell density yielded a correlation coefficient of .75. The correlations appear to indicate a relationship between these particular cells or the area they occupy and the decreased content of the two amino acids.

Amino Acids

Brain choline acetyltransferase reduction in dominantly inherited olivopontocerebellar atrophy.

We measured the activity of choline acetyltransferase, the cholinergic marker enzyme, in the brains of 17 patients from five established pedigrees with dominantly inherited olivopontocerebellar atrophy (OPCA). OPCA is a group of cerebellar ataxia disorders in which serious intellectual impairment is not typically considered to be an accompanying feature. Patients from all five pedigrees demonstrated markedly reduced choline acetyltransferase activity in the cerebral cortex, with less severe changes in the hippocampus. Although the magnitude of the cortical choline acetyltransferase deficit is comparable to that seen in the brains of patients with Alzheimer's disease, none of our OPCA patients appeared, on last examination, to have severe global dementia of the Alzheimer type. Determination of the clinical significance of our biochemical data must await the results of studies in which the cognitive status of OPCA individuals has been accurately assessed.

Brain

"Orthostatic tremor' in familial-essential tremor.

We studied a family with essential tremor of the arms. Some members also had tremor of the trunk and legs on standing, but not on walking, sitting, or reclining. Tremor was evoked, regardless of body or limb position, by strong tonic contraction of the appropriate muscles; it was a type of static postural tremor. Beta-adrenergic blockers had no effect on the tremor of the trunk or legs, but clonazepam was beneficial.

Adult

California encephalitis virus causes subacute encephalomyelitis in an adult.

A 24-year-old man from rural Mississippi had a case of California encephalitis (CE) that evolved as a subacute encephalomyelitis. The incidence of CE in adults is low, especially in the southeastern United States, and to our knowledge the clinical profile of symptomatic disease in adults has not been established. The characteristics of CE and St Louis encephalitis, the usual cause of arboviral illness affecting adults in the Southeast, differ.

Adult