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Biomedical subjects

Z Argov

Publications and source records attributed to Z Argov.

At least 91 records · Page 5Linked to original sources
PubMed1987

Muscle energy metabolism in McArdle's syndrome by in vivo phosphorus magnetic resonance spectroscopy.

Five patients with McArdle's syndrome were examined by phosphorus magnetic resonance spectroscopy (31P-NMR). Adenosine triphosphate (ATP) levels at rest were reduced by 22%, but did not fall further during exercise or contracture. The slope of work rate versus inorganic phosphate/phosphocreatine (Pi/PCr) was 42 +/- 8 joules/min/Pi/PCr in three patients without muscle wasting, compared with 13 and 16 in patients with atrophy (normal, 30 to 50 joules/min/Pi/PCr). Recovery from exercise showed similar rates in patients (postischemic exercise 1.03 +/- 0.17, post-aerobic 1.63 +/- 0.17 PCr/Pi units per minute) and controls (1.0 +/- 0.2 and 1.8 +/- 0.2, respectively) independent of intracellular pH. Infusion of glucose improved exercise kinetics by 163 to 190%, but an oral load of protein had no effect. We conclude that (1) muscle mitochondria operate normally in vivo in this glycogenolytic disorder, suggesting a sufficient alternate fuel supply. (2) Blood-borne glucose may serve as one alternate fuel for the "second wind" phenomenon. (3) ATP control mechanisms are altered only at rest. (4) Recovery from exercise is relatively pH-independent.

Adult↗
PubMed1987

Bioenergetic heterogeneity of human mitochondrial myopathies: phosphorus magnetic resonance spectroscopy study.

Twelve adults with mitochondrial myopathies were studied by phosphorus magnetic resonance spectroscopy of muscle. All 12 had abnormal 31P-NMR findings; recovery from exercise was abnormal in 11 patients. At rest, the ratio of phosphocreatine to inorganic phosphate was reduced in 10. Exercise transfer characteristics were abnormal in all five patients who could exercise. Exercise-induced intracellular acidosis was subnormal in nine patients. The range of abnormalities indicates biochemical heterogeneity, with two possible groups: primary defects of energy metabolism with marked 31P-NMR abnormalities, and secondary, less specific 31P-NMR abnormalities.

Adenosine Triphosphate↗
PubMed1987

Familial progressive neuronal disease and chronic idiopathic intestinal pseudo-obstruction.

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is characterized by recurrent episodes of bowel obstruction without mechanical cause. In five members of two Jewish-Iranian families, CIIP was associated with progressive neuronal disease, starting before age 30, with ophthalmoplegia, sensorimotor peripheral neuropathy, and hearing loss. There was no evidence of CNS involvement. The pattern suggested autosomal recessive inheritance.

Adolescent↗
PubMed1986

Ampicillin may aggravate clinical and experimental myasthenia gravis.

Ampicillin trihydrate aggravated the symptoms of two myasthenic patients. One patient had severe temporary weakness after an ampicillin sodium challenge. Ampicillin increased the preexisting electrical decrement in three rabbits with experimental autoimmune myasthenia gravis while the drug had no deleterious effects in less affected or normal animals. Myasthenic patients receiving ampicillin should be closely monitored for possible acute exacerbations.

Ampicillin↗
PubMed1986

Hexosaminidase A deficiency in adults.

Deficiency of hexosaminidase A (Hex A) in adults was found in 15 individuals from nine unrelated Ashkenazi families; 14 individuals had neurological symptoms, one was clinically intact. Clinical, biochemical and genetic findings are reported and compared to previously reported cases. The clinical picture varied between and within families and included spinocerebellar, various motor neuron and cerebellar syndromes. Psychosis appeared in 30% of cases. Involvement of three generations was recorded in one family. The phenotype appears too variable to serve as a basis for genetic classification. The level of Hex A activity in serum, leukocytes, and fibroblasts of all 14 patients was in the range of Tay-Sachs disease (TSD) homozygotes when measured by the routine heat-inactivation method. More sensitive and direct methods detected some residual activity. Cultured skin fibroblasts of patients synthesize the alpha and beta chain precursors of Hex A of the same molecular weight as that synthesized by normal fibroblasts. However, the amount of the alpha chain precursor is greatly reduced. Mature chains were not detected. The one healthy adult we studied displayed a nonuniform distribution of Hex A; while it lacked activity in the serum it had intermediate activity in fibroblasts and leukocytes.

Adolescent↗
PubMed1986

Magnetic resonance spectroscopy of normal and diseased muscles.

Phosphorus magnetic resonance spectroscopy (P MRS) affords and innovative approach to the study of the oxidative enzyme content of normal and diseased muscles. Examples of the evaluation of the enzyme content of normal muscles by an exercise protocol are provided. The protocol affords a hyperbolic work/cost profile, the Vmax of which is calculated by the reciprocal plots giving the enzyme content and the "effective Michaelis constant" with an evaluation of the resting metabolism. This steady state protocol clearly illustrates enzyme adaptation, on the one hand, and tissue atrophy particularly in the case of tissue injury, Duchenne's dystrophy, and genetic deletion of specific enzymes, on the other hand. The method is rapid, safe, and affords a quantitative evaluation of the disease process and possibilities for following appropriate therapies. So far, approx 1000 examinations of normal and diseased human limbs have been carried out in our laboratory in over the past four years.

Acidosis↗
PubMed1986

Treatment of mitochondrial myopathy due to complex III deficiency with vitamins K3 and C: A 31P-NMR follow-up study.

A patient with mitochondrial myopathy due to complex III deficiency who was treated with vitamin K3 (menadiol sodium diphosphate, 40 mg daily) and vitamin C showed clinical improvement. A 1-year study with phosphorus 31 nuclear magnetic resonance (31P-NMR) monitoring has shown that clinical and metabolic improvement was maintained by this therapy; increasing the dose of vitamin K3 to 80 mg daily improved the bioenergetic state of the patient's muscles at rest; postexercise recovery was less responsive to the increased dose; and a higher dose of vitamin K3 (80 mg/day) did not produce side effects. The differential therapeutic effects of vitamin K3 at rest and during exercise recovery are probably due to the differential kinetics of each metabolic state. Monitoring muscle bioenergetics with 31P-NMR is valuable in documenting therapeutic improvements in mitochondrial myopathies.

Adult↗
PubMed1986

Chronic demyelinating peripheral neuropathy in cerebrotendinous xanthomatosis.

Three siblings with chemically proved cerebrotendinous xanthomatosis presented with typical neurological manifestations of dementia and spinocerebellar disorder. Electrodiagnostic tests revealed demyelinating neuropathy in all three. Sural nerve biopsies showed loss of myelinated large fibers, marked Schwann cell proliferation, and onion bulb formation. Teased-fiber preparations confirmed the occurrence of segmental demyelination and remyelination. We suggest that demyelinating neuropathy is part of the neurological spectrum of cerebrotendinous xanthomatosis and should be considered in the differential diagnosis of a recessively inherited motor and sensory neuropathy.

Adolescent↗
PubMed1985

Leptomeningeal metastases: peripheral nerve and root involvement--clinical and electrophysiological study.

Twenty-five patients with recently diagnosed leptomeningeal metastases underwent a prospective clinical and electro-physiological study to assess the mode and extent of peripheral nerve and spinal root involvement. Motor conduction velocities and F wave latencies in the legs were found frequently to be disturbed compared with normal subjects and a control group of cancer patients. F wave changes were the most sensitive indicator of root involvement. Electrophysiological abnormalities were detected in 20 patients, compared with 15 who had abnormal clinical signs suggesting peripheral nerve dysfunction. Electrophysiological studies can be useful in the evaluation of patients with suspected leptomeningeal metastases, and repeated recording of F wave latencies may serve to indicate root recovery in a clinically stable patient.

Adult↗
PubMed1985

Guillain-Barré syndrome: a possible extraintestinal manifestation of ulcerative colitis.

In two elderly patients with ulcerative colitis, acute Guillain-Barré syndrome developed while the inflammatory bowel disease was in remission. The patients were treated with corticosteroids and recovered. Since both disorders are relatively uncommon, we suggest that the Guillain-Barré syndrome may have been causally related to the preexisting chronic inflammatory bowel disease. Guillain-Barré syndrome may be regarded as a possible extraintestinal complication of chronic ulcerative colitis.

Adrenal Cortex Hormones↗
PubMed1985

Immediate spasticity with acute hemiplegia is a sign of basal ganglia hemorrhage.

Acute appearance of hemiparesis or hemiplegia with initial marked spasticity was observed in 8 stroke patients. All had intracerebral hematomas and in 7 it was located in the region of the basal ganglia. By contrast, none of 121 hemiplegic patients with hemispheric ischemic stroke hospitalized during the same period had increased muscle tone in the involved limbs at stroke onset. Study indicates that association of hemiplegia with immediate spasticity at stroke onset is a clinical clue to a possible deeply located intracerebral hematoma.

Aged↗
PubMed1985

Guillain-Barré syndrome after epidural anesthesia: direct nerve root damage may trigger disease.

Guillain-Barré syndrome (GBS) appeared in four patients 1 to 2 weeks after epidural anesthesia. In all patients, clinical diagnosis was confirmed by CSF findings and nerve conduction velocity studies. Although epidural anesthesia has not been listed as an antecedent event in GBS, evidence for the relationship has been previously reported. Interaction between the anesthetic agents and peripheral nervous system myelin or local trauma to roots may initiate a cascade of immunologic events that result in the demyelinating neuropathy.

Adult↗
PubMed1984

Patterns of muscle fiber-type disproportion in hypotonic infants.

We studied the histochemical characteristics of muscle in five hypotonic infants. A number of different patterns of disproportion in the sizes and numbers of type 1 and type 2 fibers were found. In three cases, type 1 fibers were smaller than type 2 fibers and type 2b or 2c fibers were largest. In one case, type 2 fibers were smaller than type 1 fibers and were reduced in number, while in a case of Prader-Willi syndrome there was a preponderance of type 2 fibers that were smaller than type 1 fibers. Type 2c fibers were increased in number in all but one case. We postulate that these various patterns of fiber-type disproportion are the result of altered neural influences leading to impaired maturation of type 1 or type 2 motor units.

Adenosine Triphosphate↗
PubMed1984

Clinical and genetic variations in the syndrome of adult GM2 gangliosidosis resulting from hexosaminidase A deficiency.

Six patients from three families developed adult GM2 gangliosidosis resulting from severe beta-hexosaminidase A deficiency. The clinical picture varied between and within families and included spinocerebellar, various motor neuron, and cerebellar connection syndromes. Psychosis appeared in each family. Involvement of three generations was recorded in one family. The phenotype of adult GM2 gangliosidosis is variable and cannot form a basis for genetic classification. Detailed hexosaminidase determinations in eight patients from five families revealed all patients to have minor quantities of hexosaminidase A (about 15% of normal), with marked increase in hexosaminidase I isozyme.

Adult↗
PubMed1984

"Rimmed vacuole myopathy" sparing the quadriceps. A unique disorder in Iranian Jews.

Nine cases from 4 different Iranian-Jewish families presented with generalized muscular weakness. Quadriceps muscle was the only leg muscle which retained its normal power and function even in advanced cases. Biopsies from severely involved muscles revealed a typical "rimmed vacuole myopathy" while the quadriceps and deltoid showed minimal changes. CK levels were normal or moderately elevated and the EMG pattern suggested an underlining neurogenic disorder. The possible neurogenic character of this autosomal recessive disorder is discussed with relevance to the rimmed vacuoles.

Adult↗
PubMed1984

Prevention of experimental autoimmune myasthenia gravis in rats by fetal alpha-fetoprotein-rich fractions.

Rats immunized with Torpedo acetylcholine receptor (AChR) developed experimental autoimmune myasthenia gravis (EAMG) manifested by an early acute phase and a late chronic phase. In the animals the acute and the chronic diseases were prevented by the administration of alpha-fetoprotein (AFP)-rich fractions obtained from human amniotic fluid and umbilical cord serum. Both the clinical and the electromyographic manifestations of EAMG was affected by AFP treatment. The anti-AChR antibody level as well as the cellular immune response to AChR were also affected by AFP. Rats immunized with Torpedo AChR and treated with AFP-rich fractions showed low levels of antibodies to rat AChR, and an inhibited proliferation response of lymphocytes to the antigen AChR. The addition of AFP in vitro to the lymphocyte culture significantly inhibited the proliferative response to AChR and to the mitogen phytohemagglutinin. AFP is present in high amounts during pregnancy, and therefore the present findings suggest that clinical remissions of myasthenia gravis during the second half of pregnancy may be attributed to the immunosuppressive effect of AFP.

Acute Disease↗