Search PubMed⌕ Search

Biomedical subjects

S Carpenter

Publications and source records attributed to S Carpenter.

At least 199 records · Page 11Linked to original sources

Immunocytochemical studies of intermediate filament aggregates and their relationship to microtubules in cultured skin fibroblasts from patients with giant axonal neuropathy.

Giant axonal neuropathy (GAN) is a severe autosomal recessive disease affecting both the peripheral and central nervous systems. It is characterized by segmental axonal ballooning due to large neurofilamentous masses and abnormal aggregation of filaments in other cell types including glial cells. Coomassie blue staining of the detergent-resistant cytoskeleton of cultured skin fibroblasts from three patients with GAN revealed the presence of large cytoplasmic filamentous aggregates in the great majority of cells. The aggregates were birefringent when viewed under polarization microscopy and electron microscopy showed that they were composed of aggregates of 8 to 10 nm intermediate filaments. The aggregates stained with antisera specific for vimentin but did not stain with antibodies to actin, tubulin, or the high molecular weight (HMW) microtubule associated protein. Examination of the fibroblasts containing the vimentin aggregates with antibodies to tubulin and the HMW protein showed that they had a normal distribution of microtubules and that the microtubules present were normally associated with the HMW protein. The results suggest that giant axonal neuropathy is a generalized inborn error of organization of intermediate filaments and that a defect in microtubules or their association with HMW protein is not responsible for the observed aggregation of intermediate filaments in this disease. Further study of GAN may be useful in understanding the function of intermediate filaments.

Child↗

Inflammatory myopathy in a captive Bengal tiger.

A 9-year-old female Bengal tiger (Panthera tigris tigris) was presented with a history of progressive hindlimb weakness and muscle atrophy. Serum muscle enzyme activities were high, and electrophysiologic examination suggested an underlying myopathic process. Muscle biopsy revealed an inflammatory myopathy, with multifocal collections of inflammatory cells. There was severe muscle fiber necrosis with some evidence of regeneration. The cellular infiltrate consisted predominantly of macrophages, with a few lymphocytes and plasma cells. Evidence of parasitism or viral infection was not detected. Despite prolonged corticosteroid therapy, there was no clinical improvement or notable decrease in serum muscle enzymes activities. The tiger was euthanatized, and necropsy revealed generalized muscle inflammation, with no other pertinent findings.

Animals↗

A pathologic basis for Kleine-Levin syndrome.

A patient with Kleine-Levin syndrome, typical except that onset was at 39 years of age, died during a symptomatic period. Autopsy disclosed recent and old lesions in the medial thalamus involving intralaminar, medial, and some dorsal nuclei as well as the pulvinar. Despite massive microglial infiltration, there was minimal neuronal loss. The hypothalamus was not involved. The findings suggest a viral cause for Kleine-Levin syndrome.

Feeding and Eating Disorders↗

Necrosis of capillaries in denervation atrophy of human skeletal muscle.

Gastrocnemius muscles from eight adults with moderate to severe denervation of various causes (excluding vascular diseases), along with biopsy specimens from seven controls, were studies in semithin epoxy resin sections and by electron microscopy. Morphometry showed diminution in the number of capillaries per muscle fiber roughly proportional to the degree of muscle fiber atrophy. The number of capillaries per transverse muscle fiber area tended to increase. By phase microscopy, destroyed capillaries were found in all denervated muscle specimens. Denervated muscle becomes relatively overvascularized, and probably as a result, some capillaries become necrotic. This tends to restore the normal equilibrium between muscle mass and blood supply. The capillary changes of denervation can be distinguished from those in dermatomyositis.

Adult↗

Rud syndrome: congenital ichthyosis, hypogonadism, mental retardation, retinitis pigmentosa and hypertrophic polyneuropathy.

Rud syndrome consists in the association of oligophrenia and hypogonadism with congenital ichthyosis; in the majority of cases, epilepsy, short stature or delayed in growth are also found. We described a child with such a syndrome. In addition to the classical findings, the patient had retinitis pigmentosa and hypertrophic polyneuropathy. Histological studies, including ultrastructural findings of a sural nerve biopsy, showed signs of a chronic demyelinative neuropathy with onion bulb formation. The world literature was reviewed and only nine other cases fulfilled our criteria for inclusion in Rud syndrome. This case represents the one with the most extensive neurological involvement ever reported.

Child, Preschool↗

Acute sporadic non-A and non-B hepatitis in an urban community in New Zealand.

Acute sporadic non-A, non-B hepatitis is reported for the first time in New Zealand. Examination of sera from 94 patients with biochemical evidence of hepatitis showed that 26 (27%) had acute hepatitis B (HB), 22 (23%) had acute hepatitis A (HA) and 25 (26%) had acute non-A, non-B hepatitis (NANBH). Nine (10%) patients had Epstein-Barr virus (EBV) associated hepatitis and one (1%) had cytomegalovirus (CMV) hepatitis. There were 11 (13%) patients with mixed infections; eight with HA plus HB, one with HB plus EBV, one with HA plus EBV and one with HB plus CMV. Thus NANBH and EBV associated hepatitis must be considered in the differential diagnosis of patients presenting with clinical hepatitis with no history of possible percutaneous infection.

Acute Disease↗

Postnatal regulation of oxygen delivery: control of erythropoiesis following birth in dogs.

Blood hemoglobin concentration decreases during the first postnatal month of canine life. Red cell production, as indicated by reticulocyte levels, decreases following birth and does not increase until the second postnatal month. Bleeding and transfusion studies were performed to determine if the canine erythropoietic system is defective during this early neonatal period or is operating at a less than maximal rate due to adequate oxygen delivery to those tissues which regulate erythropoiesis. There is no fundamental defect in the erythropoietic system since bleeding stimulated reticulocyte formation during the first postnatal month. Conversely, the reticulocytosis that normally occurs during the second postnatal month was suppressed when oxygen delivery was increased by a red cell transfusion. We conclude that adequate oxygen delivery following birth causes a reduction in red cell production and results in postnatal anemia. Due to increasing metabolic oxygen requirements of continued growth, the blood oxygen delivery becomes inadequate by the second postnatal month and red cell production is stimulated.

2,3-Diphosphoglycerate↗

Lectin histochemistry of human skeletal muscle.

Biotinyl derivatives of seven plant lectins-concanavalin A (Con A), peanut agglutinin (PNA), Ricinus communis agglutinin I (RCA I), Ulex europeus agglutinin I (UEA I), soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), and wheat germ agglutinin (WGA)-were bound to cryostat sections of biopsied normal human muscle and visualized with avidin-horseradish peroxidase conjugates. A distinct staining pattern was observed with each lectin. The most general staining was observed with Con A, RCA I, and WGA, which permitted strong visualization of the plasmalemma-basement membrane unit, tubular profiles in the interior of muscle fibers, blood vessels, and connective tissue. PNA gave virtually no intracellular staining, while SBA and UEA I selectively stained blood vessels. DBA was unique in providing good visualization of myonuclei. In each case, lectin staining could be blocked by appropriate sugar inhibitors. Neuraminidase pretreatment of the cryostat sections altered the pattern of staining by all lectins except UEA I and Con A; staining with RCA I became stronger and that with WGA became less intense, while staining with PNA, SBA and DBA became stronger and more generalized, resembling that of RCA I. These effects of neuraminidase pretreatment are in conformity with the known structure of the oligosaccharide chains of membrane glycoproteins and specificities of the lectins involved.

Glycoproteins↗

Fatal infantile glycogen storage disease: deficiency of phosphofructokinase and phosphorylase b kinase.

A girl with congenital limb weakness, mental retardation, and corneal ulceration died with respiratory insufficiency at age 4 years. Histochemistry of muscle biopsy showed only nonspecific myopathy, but electronmicroscopy revealed subsarcolemmal and intramyofibrillar accumulation of glycogen. Biochemical studies showed increased glycogen content of muscle with lack of phosphofructokinase. Phosphorylase b kinase activity was about 30% of normal. The relationship of the double enzyme deficiency to this unusual clinical picture is unclear.

Biopsy↗

Sweat gland duct cells in Lafora disease: diagnosis by skin biopsy.

Skin biopsies of three patients with Lafora disease (clinically typical and proven by liver biopsy) showed PAS-positive inclusions in numerous peripheral cells of eccrine sweat ducts. By electronmicroscopy, the inclusions consisted of polyglucosan-type material; they were not bounded by a membrane. Skin biopsy should be a convenient method of diagnosing Lafora disease.

Adolescent↗

Sandhoff's disease (GM2 gangliosidosis type 2). Histopathology and ultrastructure of the eye.

Sandhoff's disease (GM2 gangliosidosis type 2) was diagnosed in an infant in whom a progressive neurologic disorder and cherry-red foveal spots developed. At autopsy, ultrastructural examination of the retina and optic nerve disclosed abundant pleomorphic storage cytosomes in all neurons of the retina, including the inner segments of the photoreceptor cells, and in glial cells of the optic nerve. Electron microscopy of the cornea showed, within the keratocytes, distended clear lysosomes that contained some fibrillogranular material and an occasional collection of lamellae. We discuss the pathogenesis of the clinical and pathologic ocular findings with regard to the inherited absence of the enzymes hexosaminidase A and B and an accumulation of the substrates, GM2 ganglioside and asialo GM2, in the nervous system (including retina and optic nerve) and globoside and other hexosamine-containing substances in the viscera (including cornea).

Adolescent↗

A distinct form of adult polyglucosan body disease with massive involvement of central and peripheral neuronal processes and astrocytes: a report of four cases and a review of the occurrence of polyglucosan bodies in other conditions such as Lafora's disease and normal ageing.

We have described 4 patients with progressive lower and upper motor neuron deficits, marked sensory loss in the legs, 'neurogenic bladder', and, in 2 of the 4, dementia. Autopsy of two revealed a profusion of microscopic bodies resembling corpora amylacea or Lafora bodies, but restricted to processes of neurons and astrocytes. Similar (but especially large) bodies were seen within axons of sural nerves taken at biopsy from the other two patients. A general term--'polyglucosan body'--is introduced to refer to these structures in all the circumstances in which they may occur, such as in Lafora's disease, in a syndrome of longstanding double athetosis, in some cases of amyotrophic lateral sclerosis, in type IV glycogenosis, in diabetic rats, and in the normal course of ageing. Except in type IV glycogenosis, the causes for accumulation of polyglucosan bodies are unknown. They may damage tissue by more than one mechanism--probably by impeding axonal flow and impairing perivascular diffusion of metabolites.

Aged↗