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Biomedical subjects

B W Little

Publications and source records attributed to B W Little.

18 recordsLinked to original sources
PubMed1992

Atypical Creutzfeldt-Jakob disease in an American family with an insert mutation in the PRNP amyloid precursor gene.

An American family of English origin with an unusually early onset and long-duration form of Creutzfeldt-Jakob disease (CJD) had a heterozygous insert mutation in the region of repeating octapeptide coding sequences between codons 51 and 91 of the PRNP gene on chromosome 20. Affected members were 23 to 35 years old at the onset of illnesses that lasted from 4 to 13 years, yet experimental transmission of disease from the proband (11-year duration) produced a typically brief incubation period and duration of illness in each of three inoculated primates. Also, the PrP amyloid protein that accumulates in CJD brain was only barely detectable in extracted brain tissue from one case with massive spongiform change and was undetectable in another case with no spongiform change, perhaps because of epitope shielding by a configurational change in the protein induced by the mutation. Analysis of this and other families with similar inserts suggests that such mutations in the PRNP gene not only predispose to CJD, but also modify its phenotypic expression.

Adult↗
PubMed1990

Large vascular plexiform neurofibroma of scalp: excision and coverage with free tissue transfer.

Diffuse neurofibroma (paraneurofibroma) is an unusual variant of neurofibroma in which the tumor cells diffusely infiltrate beyond the usual well-circumscribed boundary. Histological features of the tumor include both typical and plexiform neurofibroma. Although benign, diffuse vascularity with the possibility of life-threatening hemorrhage dictates treatment. The combination of preoperative angiography, wide surgical excision, and resurfacing the defect with well-vascularized tissue offers one-stage reconstruction and possible cure.

Adult↗
PubMed1988

Early-onset benign autosomal dominant limb-girdle myopathy with contractures (Bethlem myopathy).

We report a large French-Canadian kindred with 33 affected members in six generations showing early-onset autosomal dominant limb-girdle myopathy and contractures. This myopathy is unique because of its benign course, with many members only minimally impaired even in old age. Examination of affected members revealed mild to moderate proximal weakness and wasting. Contractures were observed at the elbows and ankles in all, while in some they were more widespread. Serum CK was either normal or slightly raised, and electrodiagnostic studies suggested a primary myopathy. Muscle biopsy revealed nonspecific features of a myopathy without fiber necrosis or regeneration. Cardiac involvement was absent clinically in all patients and at autopsy in two affected individuals. The similarities between four previously reported families and our own establishes this myopathy as a distinct clinicogenetic entity, for which we propose the name "Bethlem myopathy."

Adolescent↗
PubMed1988

Recurrent intracranial hemorrhage in an adult with moyamoya disease: case report, radiographic studies and pathology.

Moyamoya disease is an unusual vascular disorder highlighted by progressive bilateral internal carotid artery occlusion and collateralization of intracranial blood flow. Recurrent multifocal cerebral ischemic events and isolated intracerebral hemorrhage are known to occur in this disorder. We report a 52 year old man who over a nine year period had four apparent intracranial hemorrhages. Serial angiograms demonstrated the evolution of moyamoya disease. Pathologic examination confirmed multiple vascular lesions, including two that were clinically silent.

Adult↗
PubMed1987

Childhood giant axonal neuropathy. Case report and review of the literature.

Giant axonal neuropathy (GAN) is a rare autosomal recessive childhood disorder characterized by a peripheral neuropathy and features of central nervous system involvement. Typically seen are distal axonal swellings filled with 8-10 nm in diameter neurofilaments in central and peripheral axons, and intermediate filament collections in several other cell types. Many neurotoxins produce a morphologically similar neuropathy in humans and experimental animals. Defective nerve fiber energy metabolism has been postulated as a cause in these toxic neuropathies. It is possible that GAN represents an inborn error of metabolism of enzyme-linked sulfhydryl containing proteins, resulting in impaired production of energy necessary for the normal organization of intermediate filaments.

Axons↗
PubMed1987

Lyme disease: cause of a treatable peripheral neuropathy.

Peripheral nerve dysfunction was demonstrated in 36% of patients with late Lyme disease. Of 36 patients evaluated, 14 had prominent limb paresthesias. Thirteen of these had neurophysiologic evidence of peripheral neuropathy; neurologic examinations were normal in most. Repeat testing following treatment documented rapid improvement in 11 of 12. We conclude that this neuropathy, which is quite different from the infrequent peripheral nerve syndromes previously described in this illness, is commonly present in late Lyme disease. This neuropathy presents with intermittent paresthesias without significant deficits on clinical examination and is reversible with appropriate antibiotic treatment. Neurophysiologic testing provides a useful diagnostic tool and an important measure of response to treatment.

Adult↗
PubMed1986

Familial myoclonic dementia masquerading as Creutzfeldt-Jakob disease.

We describe a kindred with 7 confirmed and 2 probable cases of subacute dementia accompanied by myoclonus. The inheritance pattern is consistent with autosomal dominance and shows anticipation. The pathological changes involve marked gliosis with neuronal loss of the dorsomedial and midline thalamic nuclei, with lesser involvement of the anterior, lateral, and posterior thalamic nuclei. Medullary olivary hypertrophy is prominent. Spongiform change is minimal or absent. Attempted disease transmission to primates from 3 affected family members has been unsuccessful; Western immunoblot tests have likewise failed to detect the presence of specifically reactive 27-30 kD Mr proteins in brain tissue from 2 of these patients. We conclude that this family has a rare inherited neurological systems degeneration with associated thalamic dementia, the clinical course of which is very similar to Creutzfeldt-Jakob disease.

Adult↗
PubMed1982

Denervation modulated changes in mouse skeletal muscle RNA concentration.

We have examined normal and denervated mouse skeletal muscle for histological evidence of changes in RNA concentration using acridine orange/nucleic acid fluorescence. In denervated muscle, cytoplasmic RNA concentration increases dramatically. The earliest increase is in the subsarcolemmal region, 7 days after denervation. By 28 days after denervation, the increase in RNA is distributed throughout the cytoplasm of the atrophic cells, non-atrophic cells show little or no increase. Prior to the increase in cytoplasmic RNA concentration, many myocyte nuclei exhibit enlarged nucleoli, indicative of active ribosomal RNA synthesis. Such active nucleoli are present throughout the 42 day study period. We conclude that both new RNA synthesis, and preferential accumulation of cytoplasmic RNA are prominent events in denervation atrophy. There is an ordered progression from nucleolar synthesis to subsarcolemmal accumulation to diffuse accumulation in atrophying cells. These observations complement biochemical findings of others which indicate an increase in both RNA and protein synthesis after denervation.

Animals↗
PubMed1981

Heterogeneity of neutral ribonuclease II and ribonuclease II-inhibitor complex from mouse skeletal muscle.

Using either DEAE-cellulose chromatography or pH 4--6 isoelectric focusing, we have separated mouse skeletal muscle neutral RNAase II-inhibitor complex into two fractions (designated alph and beta). para-Hydroxymercuriphenyl-sulfonate-induced dissociation/inactivation of the inhibitor yields free RNAase II enzyme fractions with differing pH profiles, CM-cellulose chromatographic behavior and reactivity with the RNAase II inhibitor of human placenta. However, the free RNAase fractions react equally with purified inhibitor from skeletal muscle and are not separable by pH 8--9.5 isoelectric focusing. These data suggest that mouse skeletal muscle has two heterogeneous forms of RNAase II. Additionally, heterologous RNAase II inhibitors may be used as investigational tools when probing neutral RNAase II heterogeneity.

Animals↗
PubMed1981

Giant cell pneumonia associated with parainfluenza virus type 3 infection.

Giant cell pneumonia associated with parainfluenza virus type 3 infection and chronic poliovirus type 2 meningoencephalomyelitis are documented in an infant with combined immunologic deficiency (Swiss type). Caution should be exercised in attributing cases of giant cell pneumonia to measles virus without serologic or virologic evidence.

Humans↗
PubMed1981

Partial purification and characterization of the components of the neutral ribonuclease II-inhibitor system of normal and distrophic mouse skeletal muscle.

The complexes between a proteinaceous inhibitor and neutral ribonuclease II (EC 3.127.5) purified from low ionic strength extracts of normal and dystrophic mouse muscle are essentially indistinguishable in (a) purification behavior, (b) apparent molecular weights of approximately 50 000, (c) thermal denaturation (50% loss of activity in 5 min at 73.5 degrees C), (d) isoelectric points (pH 4.8), and (e) procedures for reversible resolution into free inhibitor and free RNase II. The free RNase II species are also similar whether obtained by resolution of the purified complexes or by direct isolation of free enzyme from dystrophic muscle. All have apparent molecular weights of 11 500 compared with 13 700 for bovine pancreatic RNase A; all retain 80% of activity after 5 min at 95 degrees C. The active RNase II prepared directly from muscle, by resolution of inhibitor complexes or by organic mercurial treatment of the inhibitor complexes, all have identical pH-activity profiles in 200 mM KC1 with an optimum near pH 7.0. In comparison RNase A has an optimum pH near 7.5 and its activity decreases more rapidly as KC1 concentration is increased above 50 mM KC1. RNase II inhibitor obtained by resolution of the purified complexes or by direct isolation in the free form from normal muscle extracts has an apparent molecular weight of 42 000 and is very sensitive to heat; it loses all activity at 40 degrees C in 5 min. These studies (a) provide methods for obtaining useful amounts of the components of the neutral RNase II - inhibitor system from muscle, (b) provide the first method reported for the reversible resolution of RNase II - inhibitor complexes, (c) fail to show any distinct difference between corresponding components of the system from normal and dystrophic mice, (d) establish interesting differences between the apparently homologous enzymes, murine muscle neutral RNase II, and bovine pancreatic RNase A, and (e) provide a substantially lower molecular weight estimate for RNase II inhibitor from muscle than has been reported for the inhibitor from liver, kidney, and placenta.

Animals↗
PubMed1980

Acridine orange-nucleic acid fluorescence. Its use in routine diagnostic muscle biopsies.

Acridine orange-RNA fluorescence in diagnostic muscle biopsies is a sensitive, specific method to identify single fibers undergoing neurogenic atrophy. Fibers thus identified may be clearly distinguished from nonfluorescent type-specific atrophic fibers, as well as from atrophic fibers encountered in other myopathic conditions. Regenerating fibers, inflammatory cells, and mast cells stain prominently with acridine orange but area easily identified by their morphologic features. Acridine orange-RNA fluorescence is extremely useful in the evaluation of early neurogenic atrophy without fiber-type grouping and may be performed on paraffin-embedded sections, thus allowing retrospective studies. In addition, this technique may provide clues to the pathogenesis of neuromuscular disease that involves altered nucleic acid metabolism.

Acridine Orange↗
PubMed1979

Immunospecificity of nuclear nonhistone protein-DNA complexes in colon adenocarcinoma.

Tumor-specific antisera against dehistonized chromatin isolated from transplantable colon adenocarcinoma (from male noninbred Sprague-Dawley rats) were produced. The specificities of these antisera were determined by complement fixation. In the presence of these antisera, only chromatin from colon adenocarcinoma significantly fixed complement, whereas chromatins isolated from normal rat colon epithelia were inactive. Administration of 1,2-dimethylhydrazine to rats produced an early change in the immunospecificity of colon epithelial chromatin similar to that for colon adenocarcinoma. Several lines of experimental evidence indicated that nuclear antigen was not a carcinoembryonic antigen-like substance. Common antigens were also present in human colon adenocarcinomas.

Adenocarcinoma↗
PubMedDate not supplied

"Chromatolytic" neurons in lateral geniculate body in Werdnig-Hoffmann disease.

In a case of Werdnig-Hoffmann disease, we have observed pathologic changes in the neuronal cell bodies of the lateral geniculate nucleus. These changes are similar to those seen in lower motor neurons and dorsal root ganglia. As the lateral geniculate nucleus and its projections are entirely central, this observation raises questions as to the possible etiologic role of root entry zone glial bundles in the evolution of neuronal alterations in severe spinal muscular atrophy.

Geniculate Bodies↗