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Biomedical subjects

R S Finkel

Publications and source records attributed to R S Finkel.

8 recordsLinked to original sources

SMN mRNA and protein levels in peripheral blood: biomarkers for SMA clinical trials.

BACKGROUND: Clinical trials of drugs that increase SMN protein levels in vitro are currently under way in patients with spinal muscular atrophy. OBJECTIVE: To develop and validate measures of SMN mRNA and protein in peripheral blood and to establish baseline SMN levels in a cohort of controls, carriers, and patients of known genotype, which could be used to follow response to treatment. METHODS: SMN1 and SMN2 gene copy numbers were determined in blood samples collected from 86 subjects. Quantitative reverse transcription PCR was used to measure blood levels of SMN mRNA with and without exon 7. A cell immunoassay was used to measure blood levels of SMN protein. RESULTS: Blood levels of SMN mRNA and protein were measured with high reliability. There was little variation in SMN levels in individual subjects over a 5-week period. Levels of exon 7-containing SMN mRNA and SMN protein correlated with SMN1 and SMN2 gene copy number. With the exception of type I SMA, there was no correlation between SMN levels and disease severity. CONCLUSION: SMN mRNA and protein levels can be reliably measured in the peripheral blood and used during clinical trials in spinal muscular atrophy, but these levels do not necessarily predict disease severity.

Biomarkers↗

Central nervous system Sjögren's syndrome in a child: case report and review of the literature.

We describe a case of pediatric Sjögren's syndrome with progressive neurologic involvement. At age 4 years, she had been diagnosed with Melkersson-Rosenthal syndrome. After being stable with facial diplegia and swelling for 5 years, she acutely presented with diplopia, vertigo, and ataxia. Cranial magnetic resonance imaging (MRI) showed a left dorsal midbrain lesion. Serologic and histopathologic findings confirmed primary Sjögren's syndrome. She responded well to intravenous methylprednisolone, with subsequent clinical improvement and MRI resolution. This report reviews the pediatric literature and underscores the importance of considering Sjögren's syndrome in a child with unexplained facial weakness and in the differential diagnosis of pediatric stroke.

Biopsy↗

Mutations that disrupt the carboxyl-terminus of gamma-sarcoglycan cause muscular dystrophy.

Recently, mutations in the genes encoding several of the dystrophin-associated proteins have been identified that produce phenotypes ranging from severe Duchenne-like autosomal recessive muscular dystrophy to the milder limb-girdle muscular dystrophies (LGMDs). LGMD type 2C is generally associated with a more severe clinical course and is prevalent in northern Africa. A previous study identified a single base pair deletion in the gene encoding the dystrophin-associated protein gamma-sarcoglycan in a number of Tunisian muscular dystrophy patients. To investigate whether gamma-sarcoglycan gene mutations cause autosomal recessive muscular dystrophy in other populations, we studied 50 muscular dystrophy patients from the United States and Italy. The muscle biopsies from these 50 patients showed no abnormality of dystrophin but did show diminished immunostaining for the dystrophin-associated protein alpha-sarcoglycan. Four patients with a severe muscular dystrophy phenotype were identified with homozygous, frameshifting mutations in gamma-sarcoglycan. Two of the four have microdeletions that disrupt the distal carboxyl-terminus of gamma-sarcoglycan yet result in a complete absence of gamma-and beta-sarcoglycan suggesting the importance of this region for stability of the sarcoglycan complex. This region of gamma-sarcoglycan, like beta-sarcoglycan, has a number of cysteine residues similar to those in epidermal growth factor cysteine-rich regions.

Amino Acid Sequence↗

Large cystic optic glioma.

A 5 1/2-year-old boy developed a huge cyst in his chiasmal glioma 4 years after radiation therapy. The cyst produced obtundation but was successfully treated.

Child, Preschool↗

The dizzy child.

Dizziness in childhood may be the result of significant vestibular or central nervous system pathology. It is the responsibility of otolaryngologists and neurologists to provide appropriate diagnosis and treatment of these disorders.

Child↗

A potential role for phospholipids in the regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in cultured C-6 glial cells. Effects of N,N-dimethylethanolamine.

The relation of the activity of the microsomal enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase, to cellular phospholipid composition was studied in C-6 glial cells. Phospholipid composition was perturbed by growth of cells in the naturally occurring amino alcohol, N,N-dimethylethanolamine. After growth of C-6 glia in 5 mM N,N-dimethylethanolamine for 24 h, reductase activity was diminished by 50%. A similar diminution in cholesterol synthesis was observed. This effect was not accompanied by any parallel change in cell growth, DNA synthesis, protein synthesis, fatty acid synthetase activity, or microsomal NADPH-cytochrome c reductase activity. The inhibition of reductase activity by N,N-dimethylethanolamine was prevented by the addition of equimolar concentrations of choline to the culture medium and, also, could be reversed completely by removal of N,N-dimethylethanolamine from the culture medium. The effect of N,N-dimethylethanolamine on reductase was associated with the formation of phosphatidyl-N,N-dimethylethanolamine which accumulated primarily at the expense of phosphatidylcholine and, after 24 h, accounted for 27% of total phospholipid phosphorus. The data demonstrate that incorporation of N,N-dimethylethanolamine into the polar head group of cellular phospholipids has a major impact on the regulation of the reductase. These observations may have particular relevance for the mechanisms of regulation of this enzyme, the cellular adaptation to alterations in membrane lipid composition, and the regulation of cholesterol synthesis in the developing nervous system.

Cells, Cultured↗