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Biomedical subjects

G Karpati

Publications and source records attributed to G Karpati.

At least 181 records · Page 10Linked to original sources
PubMed1980

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↗
PubMed1979

The effects of partial chronic denervation on forearm metabolism.

Effects of chronic denervation upon in vivo forearm metabolism were studied in six patients and six controls. The diagnosis was amyotrophic lateral sclerosis in four patients, the neuronal form of Charcot-Marie Tooth disease in one patient, and an unclassified chronic disease of the lower motor neurons in one patient. In all cases the forearm muscles showed clinical weakness and electrical evidence of denervation, while muscle biopsy from a proximal muscle of the upper limb showed typical denervation atrophy. At rest there was increased oxygen utilization and lactate output as well as a tendency for increased uptake of glucose and long chain fatty acids from arterial blood per 100 ml of forearm tissue. During exercise the abnormally high lactate output increased further. An increased arterial lactate concentration was present during rest and exercise. Oxidation of fatty acids was not impaired. It is suggested that these abnormalities are consistent with an augmented utilization of blood borne fuels at rest by denervated muscles. A concurrent regional ischemia of muscles during rest and exercise, possibly due to defective autoregulation of skeletal muscle blood flow, may explain the abnormally high lactate generation.

Adult↗
PubMed1979

Duchenne muscular dystrophy: plasma membrane loss initiates muscle cell necrosis unless it is repaired.

Study of biopsies from 30 boys with Duchenne muscular dystrophy suggests that necrosis of muscle cells is initiated by loss of plasma membrane, followed, after a short interval, by Z disc lysis and mitochondrial changes to constitute the picture of fully developed necrosis. Empty basal lamina tubes containing collagen indicated that regeneration may fail to occur. The tubes form a basis for collagen deposition. Evidence suggests that small patches of membrane loss can be repaired, though a slice of superficial cytoplasm is lost, and a piece of detached basal lamina results. The markedly hypercontracted fibres seen did not show features of necrosis.

Biopsy↗
PubMed1978

Pathological involvement of primary sensory neurons in Werdnig-Hoffmann disease.

Seven patients with the typical clinical picture and muscle biopsy findings of classical Werdnig-Hoffmann disease showed Wallerian degeneration in their biopsied sural nerves. In dorsal root ganglia of one patient there were residual nodules and several chromatolytic neurons. By electron microscopy the changes of chromatolysis were confirmed and found to be consistent with an axonal reaction. Involvement of the primary sensory neuron is probably a regular pathologic feature of Werdnig-Hoffmann disease. The type of abnormality suggests in initial failure of the axon distal to the nerve roots.

Axons↗
PubMed1978

Inclusion body myositis: a distinct variety of idiopathic inflammatory myopathy.

We report six cases of inclusion body myositis (IBM), a distinct but infrequently recognized inflammatory disease of skeletal muscle. Clinically, IBM differs from dermatomyositis and polymyositis. It lacks features of collagen-vascular disease, has a relatively benign and protracted course, frequently involves distal muscles, is found mainly in males, and does not improve with corticosteroid treatment. Electronmicroscopic demonstration of abnormal filaments in muscle cells is necessary for definite diagnosis, but IBM may be suspected by the finding on cryostat sections of numerous hematoxylinophilic granules in "lined" vacuoles in muscle cells. These correspond to whorls of cytomembranes. Although in dermatomyositis the capillary network is partly destroyed, in IBM it is usually augmented. A viral etiology of IBM has been suggested but remains unproven.

Adolescent↗
PubMed1977

The ultrastructural characteristics of the abnormal cytosomes in Batten-Kufs' disease.

Patients with Batten-Kufs' disease may be divided into three groups by electronmicroscopy of their storage deposits. In the first group, those characterized by curvilinear profiles, there is a strong correlation with a particular clinical syndrome, the late infantile form of the disease. In the second group, characterized by finger-print profiles, there is great diversity as to age and type of presentation. This is paralleled by diversity in the deposits. To the third group belongs the infantile form of the disease, as well as rare patients with later onset. Pathological diagnosis can be reliably, conveniently and consistently made from biopsy of skin by electronmicroscopy, and usually from biopsy of skeletal muscle as well.

Age Factors↗
PubMed1977

Juvenile dystonic lipidosis: an unusual form of neurovisceral storage disease.

An unusual neurovisceral lipid storage disorder in two unrelated juvenile patients manifested itself by dystonia and involuntary movements, with facial grimacing, dysarthria, gait difficulty, and impaired manual dexterity. Supranuclear paresis of vertical gaze and splenomegaly were present. Absent were seizures, major intellectual deterioration, spasticity, or blindness. Histiocytes showed lysosomal storage of various phospholipids, cholesterol, neutral lipids, and autofluorescent material. Appendiceal neurons showed only an increse of phospholipids by histochemistry. Neuronal deposits differed ultrastructurally from these in histiocytes. Leukocyte sphingomyelinase activity was normal. The nosology of this disease and its relationship to so-called juvenile types of Niemann-Pick disease is discussed. The primary metabolic defect in these patients remains unknown.

Adolescent↗
PubMed1976

The childhood type of dermatomyositis.

The childhood type fo dermatomyositis, which occurs in children and young adults, shows a specific constellation of pathologic changes in muscle. Capillary necrosis leads to capillary loss, generally starting on the periphery of muscle fascicles. Electron microscopy discloses undulating tubules in endothelial cells, lymphocytes, pericytes, and pseudosatellite cells. The muscle fiber damage is coextensive with capillary damage and probably results from progressive ischemia. The muscle cells, before atrophying, show mitochondrial elongation, Z disk streaming, focal myofibrillary loss, and occassionally selective thick filament loss. Muscle cell necrosis is rare and limited to infarctlike lesions. Inflammatory infiltrates, if present, occur only in connective tissue septa. The cause of the capillary damage has not been determined.

Adult↗
PubMed1976

Cardiac myxoma: a diagnostic challenge for the neurologist.

Three patients with left atrial myxoma presented with prominent neurologic symptoms and signs (cerebrovascular disease and/or syncope) within the past year. Two patients died because antemortem diagnosis was late or missed. One patient was successfully treated. Cardiac myxoma produces protean clinical manifestations that do not always include cardiac signs and symptoms. Neurologists may be called on for diagnostic consultation in patients who will prove to have cardiac myxoma. Unexplained transient ischemic attacks, cerebral infarction, or syncope (with possible features of seizure activity) are common neurologic manifestations of this disease. Additionally, systemic symptoms, signs, and laboratory data suggestive of collagen vascular disease or vasculitis are also often present. Echocardiography is a dependable noninvasive procedure for a confirmation of diagnosis in suspected cases.

Adult↗
PubMed1975

Experimental mitochondrial myopathy produced by in vivo uncoupling of oxidative phosphorylation.

Two uncouplers of mitochondrial oxidative phosphorylation [2,4-dinitrophenol (DNP) and carbonylcyanide-m-chlorophenylhydrazone (CCCH)] were infused intra-arterially into a branch of the lower abdominal aorta of anesthetized rats over a 60-180 min period. An acute, severe, hypermetabolic state with systemic lactic acidosis and stiffness of the lower extremeities developed. In the plantaris muscles, by histochemistry, numerous "ragged red" fibers were present after the infusion. The "ragged red" areas presumably represented an absolute increase in mitochondrial mass in affected muscle fibers. By electron microscopy, linear inclusions were present in the intracristal space of many mitochondria. Simultaneous infusion of DNP and chloramphenicol, an inhibitor of mitochondrial protein synthesis, prevented the formation of ragged red fibers but not the intracristal inclusions. Infusion of relatively large amounts of oleic acid produced histochemical and electron-microscopic changes similar to those caused by the uncouplers. A possible pathogenesis of these reversible mitochondrial changes was discussed and their potential relevance to morphologic abnormalities of skeletal muscle mitochondria in human diseases was reviewed.

Animals↗
PubMed1975

The syndrome of systemic carnitine deficiency. Clinical, morphologic, biochemical, and pathophysiologic features.

An 11-year old boy had had recurrent episodes of hepatic and cerebral dysfunction and underdeveloped musculature. Overt weakness developed at age 10. Lipid excess, especially in type I fibers, was found in muscle. Hypertrophied smooth endoplasmic reticulum and excessive microbodies were present in liver. Marked carnitine deficiency was shown in skeletal muscle, plasma, and liver. Ketogenesis was impaired on a high fat diet, but omega oxidation of fatty acids was enhanced. There was excessive glucose uptake and essentially no oxidation of labeled long-chain fatty acids by perfused forearm muscles in vivo. Oral replacement therapy restored plasma carnitine levels to normal, but not liver or muscle carnitine levels, and was accompanied by clinical improvement.

Adenosine Triphosphatases↗
PubMed1975

The motor unit profile in two experimental chronic myopathies.

The motor unit profile of the rat soleus muscle has been studied in two types of experimentally induced chronic myopathy. Tetrabenazine administered for 6 weeks resulted in a moderate myopathy characterized by necrosis, regeneration, and hypertrophy of muscle fibers. This model was associated with a normal motor unit count. The twitch tension of the muscle remained normal, presumably because of hypertrophy of some of the soleus muscle fibers; however, tetanic tension was reduced. The twitch time to peak became very prolonged. Another myopathy, characterized only by regenerating muscle fibers, was produced 6 weeks after abdominal aortic ligation. In this model, the soleus motor unit count was also normal. Twitch and tetanic tensions were reduced, and the contraction time was prolonged. The findings are discussed in relation to the motor unit profile reported in human neuromuscular diseases.

Animals↗