Search PubMed⌕ Search

Biomedical subjects

A Pestronk

Publications and source records attributed to A Pestronk.

At least 91 records · Page 5Linked to original sources

Different patterns of glycolipid antibody reactivity: lower motor neuron syndromes vs. immunization.

High titers of serum antibodies against GM1 ganglioside occur frequently in patients with lower motor neuron (LMN) syndromes. We compared the specificities of the antiganglioside antibody reactivities in LMN patients with those arising after immunization of Lewis rats with several ganglioside containing preparations including purified GM1, human central nervous system (CNS) grey matter and white matter. Serums with high titers of anti-GM1 antibodies from patients with LMN syndrome usually showed limited cross-reactivity to other glycolipids but often bound to a Gal(beta 1-3)GalNAc-containing neoglycoprotein. In contrast, serums with anti-GM1 antibody arising after immunization showed broad cross-reactivity with other glycolipids but did not bind to the neoglycoprotein. We conclude that the serum patterns of antiganglioside antibody reactivity secondary to immunization with gangliosides and CNS components are different from the natural autoantibodies found in LMN patients. The antiganglioside antibodies seen in LMN patients are unlikely to be a result of autoreactivity to gangliosides after nervous tissue damage.

Animals↗

Prednisone in Duchenne dystrophy. A randomized, controlled trial defining the time course and dose response. Clinical Investigation of Duchenne Dystrophy Group.

A randomized, controlled trial of daily prednisone was conducted in 99 boys (aged 5 to 15 years) with Duchenne dystrophy to define the time course of improvement and the dose response to treatment. Prednisone at 0.3 mg/kg (n = 33), prednisone at 0.75 mg/kg (n = 34), and placebo (n = 32) were administered for 6 months. Patients were examined using manual muscle and myometry testing, timed functional testing, pulmonary function testing, and laboratory measurements at 10 days, 1 month, 2 months, 3 months, and 6 months of treatment. Boys treated with prednisone had stronger average muscle strength scores, than did boys treated with placebo as early as 10 days after starting therapy. At the 3-month visit, the boys in the group given 0.75 mg/kg of prednisone were significantly stronger than those in the group given 0.3 mg/kg of prednisone, indicating a dose response. At 6 months, significant side effects occurred in the group treated with 0.75 mg/kg of prednisone, including weight gain, cushingoid appearance, and excessive hari growth. Only weight gain was observed in the group taking prednisone at a dose of 0.3 mg/kg. Importantly, no side effects were evident at 10 days or 1 month of treatment, despite improvement in muscle strength and function. We conclude that prednisone produces a rapid increase in muscle strength in patients with Duchenne dystrophy and that this improvement is maximal at a prednisone dosage of 0.75 mg/kg or less.

Adolescent↗

A comparison of daily and alternate-day prednisone therapy in the treatment of Duchenne muscular dystrophy.

We previously reported the results of a randomized, double-blind 6-month trial of prednisone therapy in which 102 boys aged 5 to 15 years with Duchenne muscular dystrophy received daily doses of 1.5 and 0.75 mg/kg per day and were compared with those receiving placebo. The strength and function in both prednisone-treated groups improved equally and were significantly better than in the placebo group. To compare alternate-day and daily dosing of prednisone with respect to benefits and adverse side effects, the placebo group was started on alternate-day prednisone therapy, and the treatment group regimens were changed to equivalent doses of alternate-day prednisone without breaking the double-blind nature. At the end of 6 months, the group that was changed from daily to alternate-day therapy had declined in strength back to levels observed 12 months previously, at the start of daily therapy. The group in which alternate-day therapy was started showed a significant improvement in strength at 3 months, similar in magnitude to the response of boys treated with daily therapy. However, their strength declined significantly in the subsequent 3 months compared with boys who received daily therapy. The frequency of side effects was not significantly different for alternate-day therapy compared with daily therapy. We conclude that alternate-day prednisone therapy effectively increases strength but does not sustain the improvement to the same extent as daily therapy or mitigate side effects.

Adolescent↗

Immunosuppressive treatment in multifocal motor neuropathy.

We report the results of immunosuppressive treatments of 13 patients with multifocal motor neuropathy and elevated titers of serum antibodies to the GM1 ganglioside. All patients failed to respond to oral prednisone. There was no clinical response in 4 patients treated with plasma exchange. Nine patients received cyclophosphamide, with clinical improvement and fall in antibody titers in 8. In 3 patients, cyclophosphamide was discontinued with ensuing clinical relapse and rise in the titers of serum anti-GM1 antibodies. These patients provide further evidence for the efficacy of cyclophosphamide therapy in patients with multifocal motor neuropathy.

Adult↗

Invited review: motor neuropathies, motor neuron disorders, and antiglycolipid antibodies.

High titers of IgM anti-GM1 antibodies are commonly found in the serum of patients with some lower motor neuron disorders and peripheral neuropathies. Enzyme-linked immunosorbent assays (ELISA) are useful for the detection and quantitation of anti-GM1 antibodies. Testing for serum anti-GM1 activity is indicated in the diagnostic evaluation of lower motor neuron syndromes. The presence of high titers of anti-GM1 antibodies mandates careful electrophysiologic testing for the motor conduction block that is found in multifocal motor neuropathy, a treatable disorder. Quantitation of anti-GM1 antibodies may also be a useful guide in the treatment of multifocal motor neuropathy. Further study of antiglycolipid antibodies in motor neuron disorders and peripheral neuropathies may provide clues to the events that stimulate these antibodies and to the pathogenesis of such syndromes.

Amyotrophic Lateral Sclerosis↗

Autoantibodies to GM1 ganglioside: different reactivity to GM1-liposomes in amyotrophic lateral sclerosis and lower motor neuron disorders.

We studied the ability of anti-GM1 ganglioside antibodies to bind to GM1 in a lipid, "membrane-like" environment. Liposomes containing GM1 were synthesized to simulate this environment. We then compared the binding of anti-GM1 a autoantibodies to GM-1-liposomes and to purified GM1. Antibody binding was quantitated using enzyme-linked immunosorbent assay methodology. Our results showed a 250-fold variation in the ability of anti-GM1 antibodies to bind to GM1-liposomes. There was no correlation between GM-1-liposome binding and the carbohydrate specificities of the anti-GM1 antibodies. However, anti-GM1 antibodies from patients with amyotrophic lateral sclerosis (ALS) showed a 4 fold greater binding to GM1-liposomes than antibodies from patients with lower motor neuron (LMN) syndromes. We conclude that a lipid, presumably "membrane-like", environment may greatly influence the degree of anti-GM1 antibody binding to GM1. The low levels of anti-GM1 antibody binding to GM1-liposomes in patients with LMN syndromes may provide a diagnostic means for distinguishing these patients from those with ALS. Anti-GM1 antibodies from patients with ALS may bind especially well to neuronal membranes containing GM1 in vivo.

Amyotrophic Lateral Sclerosis↗

Limb apraxia without aphasia from a left sided lesion in a right handed patient.

A right handed man had a massive left middle cerebral artery stroke. CT and MRI revealed extensive destruction of both anterior and posterior areas typically associated with language. There was, however, no aphasia, but instead a marked limb apraxia, dyscalculia, dense right visual neglect, and anosognosia. These uncommon dissociations and associations support the hypothesis that cerebral control of motor function of the limbs is not fundamentally related to the motor control involved in speech, and the notion that handedness is related to laterality of motor control, and only accidentally to laterality of language control.

Aged↗

Long-term benefit from prednisone therapy in Duchenne muscular dystrophy.

Two successive, 6-month, randomized, double-blind, controlled trials of prednisone showed that 0.75 mg/kg/d was the optimal dose to improve strength in boys with Duchenne muscular dystrophy (DMD). We attempted to maintain 93 boys on that dose for an additional 2 years. During the 3 years of observation, the decline in average muscle strength scores of all boys taking prednisone was 0.072 units/yr, as compared with an expected decline of 0.341 units/yr from natural history controls. The occurrence of side effects in some boys prevented maintenance of the full dose, which may have lessened the response. At the time of last visit, dosages ranged from 0.15 mg/kg to 0.75 mg/kg. In addition to maintaining their strength, several of the boys actually improved their performance in lifting kilogram weights and in some timed function tests. Treatment of DMD with prednisone significantly slows the progression of weakness and loss of function for at least 3 years.

Adolescent↗

Polyneuropathy syndromes associated with serum antibodies to sulfatide and myelin-associated glycoprotein.

We studied a series of 64 patients with sensory +/- motor peripheral neuropathies by comparing clinical and physiologic features to serum antibody reactivity against compounds containing sulfated carbohydrate moieties. We determined antibody reactivity by an enzyme-linked immunosorbent assay (ELISA) using purified glycolipids and glycoproteins as antigens, and we used high-performance thin-layer chromatography and Western blotting to test the specificity of results. Twelve patients with high titers of IgM antibodies directed against the myelin-associated glycoprotein (MAG) had sensory-motor polyneuropathies with physiologic evidence of demyelination. IgM antibody reactivity to MAG was associated with an IgM serum M protein in five patients. Eight other patients, most with sensory greater than motor polyneuropathies, had high titers of antibody reactivity to sulfatide but not of IgM to MAG. Two had an associated IgM paraprotein. None of the patients with selective serum antisulfatide activity had predominantly demyelinating features on physiologic testing. We conclude that (1) high ELISA titers of antibodies to MAG may be more common than previously suspected in patients with chronic demyelinating sensory-motor neuropathies, and (2) the presence of high titers of antisulfatide antibodies in serum may provide clues to the pathogenesis of otherwise idiopathic, axonal, predominantly sensory neuropathies.

Adult↗

Lower motor neuron syndromes defined by patterns of weakness, nerve conduction abnormalities, and high titers of antiglycolipid antibodies.

We studied 74 patients with progressive, asymmetrical lower motor neuron syndromes. Clinical features of these patients, including age, sex, disease duration, patterns of weakness, and reflex changes, were evaluated by review of records. In each patient the clinical features were compared to the type of nerve conduction abnormalities and to the specificities of high-titer serum antiglycolipid antibodies. Antibody specificities were determined by an enzyme-linked immunosorbent assay using purified glycolipids and carbohydrates as substrates. Our results show that high titers of antibodies to glycolipids are common in sera of patients with lower motor neuron syndromes. Selective patterns of reactivity indicate that specific carbohydrate epitopes on the glycolipids are the targets of the high-titer antibodies in individual patients with lower motor neuron syndromes. Several distinct lower motor neuron syndromes can be identified based on clinical, physiological, and antiglycolipid antibody characteristics. These syndromes include multifocal motor neuropathy with evidence of multifocal conduction block on motor, but not sensory, axons and frequent (84%) high titers of anti-GM1 ganglioside antibodies; a lower motor neuron syndrome with predominantly distal weakness early in the disease course, no conduction block, and a high incidence (64%) of anti-GM1 antibodies; and a lower motor neuron syndrome with predominant early weakness in proximal muscles and serum antibodies to asialo-GM1 that do not cross-react with GM1 ganglioside.

Adult↗

Abnormal excitatory amino acid metabolism in amyotrophic lateral sclerosis.

Recently, the excitatory amino acid neurotransmitter glutamate was implicated in the pathogenesis of a variety of chronic degenerative neurological diseases in humans and animals. This report describes abnormalities in excitatory amino acids in the central nervous system of 18 patients with amyotrophic lateral sclerosis (ALS). The concentration of the excitatory amino acids glutamate and aspartate in the cerebrospinal fluid were increased significantly (p less than 0.01) by 100 to 200% in patients with ALS. Similarly, the concentrations of the excitatory neuropeptide N-acetyl-aspartyl glutamate and its metabolite, N-acetyl-aspartate, were elevated twofold to threefold in the cerebrospinal fluid from the patients. There was no relationship between amino acid concentrations and duration of disease, clinical impairment, or patient age. In the ventral horns of the cervical region of the spinal cord, the level of N-acetyl-aspartyl glutamate and N-acetyl-aspartate was decreased by 60% (p less than 0.05) and 40% (p less than 0.05), respectively, in 8 patients with ALS. Choline acetyltransferase activity was also diminished by 35% in the ventral horn consistent with motor neuron loss. We conclude that excitatory amino acid metabolism is altered in patients with ALS. Based on neurodegenerative disease models, these changes may play a role in motor neuron loss in ALS.

Adult↗

Neurofilament phosphorylation in peripheral nerve: changes with axonal length and growth state.

We have previously reported that the intrinsic ability of motor axons to sprout can vary considerably from nerve to nerve with an inverse correlation to axonal length. In this study we asked whether this variation might be associated with differences in one axonal component, neurofilaments, near the site of outgrowth. The phosphorylation of epitopes on the heavy subunit of neurofilaments (NF-H) was compared in normal and regenerating axons from long and short nerves in the rat. Quantitative determination of phosphorylation states on NF-H epitopes was made by measuring immunoreactivity to monoclonal antibodies using an enzyme-linked immunosorbent assay system. Our results showed a much higher degree of phosphorylation of epitopes on NF-H in terminal portions of short compared to long axons. There was a significant inverse correlation between phosphorylation of NF-H epitopes and axonal length. In newly formed sprouts NF-H phosphorylation was reduced compared to normal. However, the absolute levels were related to the degree of NF-H phosphorylation in the parent axons. The ability to phosphorylate axonal proteins near the site of outgrowth may correlate with the potential for plastic changes in the axon such as sprouting.

Animals↗

A syndrome of asymmetric limb weakness with motor conduction block.

We describe 3 patients with asymmetric limb weakness, fasciculations (2 patients), relatively preserved reflexes, normal cranial nerves, and few or no sensory abnormalities. The symptoms had been progressive over 1 to 15 years. Detailed motor nerve conduction studies showed conduction block and slowing localized to sharply circumscribed areas 30 to 100 mm long in several nerves in each patient. By contrast, the sensory conduction studies over the same nerve segments were normal, indicating very selective involvement of motor fibers. Sural nerve biopsies showed minor changes that varied among the patients. One patient had high levels of anti-GM1 antibodies, 1 had mildly elevated levels, and 1 had high levels of only asialo-GM1 antibodies. Treatment with immune suppressive therapy has produced minimal improvement in 1 patient.

Electrophysiology↗

The first neurology book written in English (1650) by Robert Pemell. De Morbis Capitis.

In 1650 Robert Pemell, an English country physician, published De Morbis Capitis; or, Of the Chief Internal Diseases of the Head, the first neurology book written in English. Two factors are probably responsible for the appearance of this book. It was written during the 17th century, a period when the number of medical books published in English increased six-fold. In addition, there was a need for texts in English. Most poor people could not afford a physician's care and were ministered to by laymen who could not read Latin. The text of De Morbis Capitis was based on the works of contemporary and ancient authors. It contains chapters on modern syndromes, eg, headache, paralysis, epilepsy, and vertigo, as well as disorders of the time, eg, incubus and phrenitide. Each chapter first describes the disease and its differential diagnosis and then provides remedies, including herbals and bleeding. Overall, the treatment of brain diseases, as outlined in De Morbis Capitis, is probably a description of a high standard of neurologic practice in the 17th century English countryside.

England↗

Patterns of serum IgM antibodies to GM1 and GD1a gangliosides in amyotrophic lateral sclerosis.

We studied the incidence and clinical correlates of serum antibodies to GM1 and GD1a gangliosides in patients with classical amyotrophic lateral sclerosis (ALS) and other "motor nerve" syndromes. Serum antibodies to GM1 and GD1a gangliosides were measured using enzyme-linked immunosorbent assays. Our results showed that polyclonal immunoglobulin M (IgM) antibodies to the GM1 or GD1a ganglioside or both were present at serum dilutions of 1:25 to 1:4,000 in 78% (57/73) of patients with ALS. Only 8% of normal controls had similar antibodies. The pattern of serum antibody reactivity correlated with the pattern of clinical involvement in our patients. Selective reactivity to GD1a ganglioside was common when upper motor neuron signs were prominent. IgM reactivity to GM1 ganglioside was common in ALS patients with prominent lower motor neuron signs. Most patients with motor neuropathies had serum reactivity to both GM1 and GD1a gangliosides. These results provide further evidence of ongoing autoimmune processes in ALS patients. There is a strong relationship between serum antiganglioside antibodies and patterns of clinical involvement in ALS.

Adult↗

Silver cholinesterase immunocytochemistry: a new neuromuscular junction stain.

Evaluation of morphological alterations at the neuromuscular junction associated with sprouting or other pathological changes has been limited by the inability to visualize simultaneously the multiple cell types that make up a junction. A new combined stain for the concurrent demonstration of motor nerve terminals, cholinesterase, and Schwann cell myelin and other antigens at neuromuscular junctions using bromoindoxyl acetate dye staining for cholinesterase, silver-gold impregnation for nerve terminals, and immunocytochemistry of selected antigens is described. The clarity of the stain permits graphic demonstration of the alteration of neuromuscular junction components during sprouting as well as other pathological changes.

Animals↗

The MRL +/+ mouse: a new model of tubular aggregates which are gender- and age-related.

Congenic mice of the MRL +/+ substrain provide an animal model for study of tubular aggregates in skeletal muscle. Tubular aggregates appear limited only to males of the MRL +/+ strain and are not found in other strains, including MRL +/-, MRL lpr/lpr, BXSB/MpJ, BALB/c, SJL/J, AJ, or C3H HEJ. This strain-specific occurrence, and the gradually increasing abundance of tubular aggregates after 6 months of age until virtually all type II myofibers are affected by 2 years, implies that both genetic and developmental factors are necessary for the occurrence of tubular aggregates. These two factors are not sufficient, however, since hormonal alteration by male castration nearly completely prevents the expression of tubular aggregates. Parallels are drawn with how expression of tubular aggregates is limited largely to males in diverse acquired and hereditary human neuromuscular disorders.

Animals↗