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Biomedical subjects

H Reichmann

Publications and source records attributed to H Reichmann.

At least 145 records · Page 8Linked to original sources
PubMed1994

Influence of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, lipoic acid and L-deprenyl on the interplay between cellular redox systems.

For several years there is controversy concerning the toxic potency of reaction products catalyzed by monoamine oxidase in neurodegenerative processes. There is uncertainty whether products of catecholamine oxidation are pathogenetically relevant factors for neuronal cell death in Parkinson's disease. To date products responsible for impairment of biochemical functions essential for cell viability are not yet identified, and the primary site of damage within the cell is unknown. Ammonia, aldehydes and hydrogen peroxide are formed via monoamine oxidase catalyzed oxidations of primary amines. But which of them, if any, is damaging to the cell? We discuss some aspects of the oxidative stress theory of cell degeneration in relation to toxicity of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and to monoamine oxidation. Furthermore, we consider possible functional relationships of mitochondrial electron transfer reactions, toxicity of MPTP and MAO activity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1994

[MELAS syndrome. Clinical aspects, MRI, biochemistry and molecular genetics].

MELAS is a mitochondrial cytopathy characterized by encephalopathy with stroke-like episodes and lactic acidosis. Most patients exhibit an A-G transition mutation at np 3243 of mitochondrial DNA (tRNA(Leu)(UUR)). We present a family of four in which the mutation was discovered in blood and in muscle mt DNA. Two patients had the classic MELAS syndrome with multiple stroke-like episodes. Some episodes were precipitated by metabolic stress. The remaining two patients had an oligosymptomatic disease with mild chronic encephalopathy, small stature and hearing loss. MRI was followed over a period of 4-8 years, during which the MELAS patients showed progression from nonspecific multifocal signal change to typical extensive cortico-subcortical parieto-occipital lesions and progressive cerebral atrophy. MRI in the oligosymptomatic cases was normal, or showed non-progressive cerebellar atrophy. Biochemical findings were non-specific, indicating increased mitochondrial volume in all cases, and a relatively complex IV defect in one case. All patients were treated with coenzyme Q with varying clinical response. The percentage of mutant mt DNA in blood and muscle did not correlate with clinical severity. Pathogenetic theories based on molecular genetics, and the therapeutic regimen in terms of the underlying biochemical concepts are discussed.

Adolescent↗
PubMed1993

[Is chronic dermato- or polymyositis misdiagnosed as "weakness of old age"?].

Two women, aged 72 (case 1) and 77 (case 2) were referred for neurological diagnosis because of progressive muscular weakness, for 4 and 18 months, respectively, which had finally led to dysphagia and required mechanical ventilation. The cause of the disease in case 1 was classical dermatomyositis. Creatinine kinase concentration, never previously measured, was 950 U/l. In case 2 there was polymyositis, previously not considered as she had a diabetic polyneuropathy and muscle enzyme concentration was normal. In both cases the correct diagnosis was speedily confirmed by electromyography and muscle biopsy. Immunosuppressive treatment was largely successful in reversing the symptoms (case 1: initially 500 mg methylprednisolone daily, reduced to 50 mg daily within 6 weeks; case 2: 500 mg methylprednisolone daily for 1 week, then 100 mg daily plus 150 mg azathioprine with maintenance dosage of 20 mg glucocorticoid daily).--These two cases demonstrate that, particularly in the elderly, dermatomyositis and polymyositis should be considered in the differential diagnosis of progressive general weakness.

Aged↗
PubMed1993

A rapid fluorometric method for the determination of carnitine palmitoyltransferase.

A rapid and sensitive fluorometric assay for the measurement of carnitine palmitoyltransferase (CPT) activity is described. In this assay the coenzyme A (CoA) liberated from palmitoyl-CoA by CPT reacts with N-(9-acridinyl)-maleimide to form a fluorescent product. By comparing the fluorescence intensities of external CoA standards, CPT activity can be determined. The coefficients of variation within-run and between-run of the method were 6.9 and 10%, respectively. The CPT activity of human muscle samples measured with this assay is comparable to those obtained with a commonly used radiochemical assay and CPT deficiency in skeletal muscle from a patient was detected by this new fluorometric assay.

Animals↗
PubMed1993

Focal myositis of the temporal muscle.

Focal myositis is a rare inflammatory disease of the skeletal muscle that may involve any part of the body. We present a 19-year-old man with a short history of a painful pseudotumor in the right temporal region. MRI pictures showed a swollen right temporal muscle and muscle biopsy revealed the characteristic histological and immunocytochemical findings of polymyositis.

Adult↗
PubMed1993

Progression of myopathology in Kearns-Sayre syndrome: a morphological follow-up study.

We report on the progression of myopathology by comparing two biopsies from a patient with a Kearns-Sayre-Syndrome. The first biopsy was taken in 1979 and showed 10% ragged-red fibers. Myopathic changes were slight including internal nuclei and fiber splitting in 10% of the fibers. Electron microscopy revealed typical mitochondrial abnormalities with regard to number and shape. In 1989 a second biopsy was performed for an extended analysis of mitochondrial DNA. This time less than 5% of all fibers were ragged-red. Severe myopathic changes could be detected which so far has rarely been reported in mitochondrial cytopathy.

Blotting, Southern↗
PubMed1993

The use of monoclonal antibodies in diagnostic tests for Becker and Duchenne muscular dystrophy.

Monoclonal antibodies recognizing different epitopes of dystrophin have now been widely applied in diagnostic tests for Duchenne and Becker muscular dystrophy (BMD). The preservation of the C-terminus in BMD patients necessitates the routine use of one antibody raised against this region. Additional antibodies against deletion-prone regions of dystrophin further increase the diagnostic power of the tests. We describe two cases which illustrate that the combined use of different antibodies is necessary to avoid misdiagnoses of BMD at the protein level.

Adult↗
PubMed1993

Analyses of energy metabolism and mitochondrial genome in post-mortem brain from patients with Alzheimer's disease.

Biochemical and mitochondrial DNA analyses were performed in post-mortem brain tissue from seven patients with dementia of Alzheimer's type and age- and sex-matched controls. We analysed all complexes of the respiratory chain in four regions, i.e. temporal, parietal, entorhinal cortex and hippocampus. Although enzymes representing complex II, III and IV were reduced in activity, succinate cytochrome c reductase was significantly reduced only in the parietal and temporal cortex. However, Southern blot analyses with two restriction enzymes excluded any deletions larger than 500 bp in parietal and entorhinal cortex. It is concluded that there seems to be no specific respiratory chain defect in Alzheimer's disease.

Aged↗
PubMed1993

Hypertrophic cardiomyopathy with mitochondrial myopathy. A new phenotype of complex II defect.

Two brothers, 25 and 19 years old, were affected by asymmetrical hypertrophic cardiomyopathy. The older brother had waddling gait and weakness of the proximal girdle muscles, while the younger had a broad-based gait and weakness of selected limb girdle muscles. EMG exam was myopathic. Serum enzyme, CPK and aldolase were elevated. Histochemical reactions in muscle revealed "core-like" areas, subsarcolemmal rims of mitochondria and lipid accumulation. Succinate-dehydrogenase stain showed a lack of activity in both biopsies, with the exception of intrafusal fibers. Microphotometric quantitative measurements confirmed the defect in both biopsies. Biochemical measurements of several mitochondrial enzymes in muscle showed a reduced activity of succinate-dehydrogenase (33%) and succinate-cytochrome C reductase (36-47%) which are both components of complex II. On myocardial biopsy lipid and mitochondrial abnormalities were found. This mitochondriopathy represents a new phenotype of partial complex II defect.

Adult↗
PubMed1993

[Therapy of metabolic myopathies].

Metabolic myopathies are subdivided into disturbances of anaerobic cytoplasmic and aerobic mitochondrial metabolism. With the exception of carnitine deficiency these myopathies are based on enzymopathies. Since gene therapy is not yet available no causal therapy is possible. This paper discusses possibilities for symptomatic therapy. Good results are found with carnitine substitution. Enzymopathies can be improved by using other metabolic pathways or by addition of co-factors of the impaired pathways. This leads to a reduction of myalgia, cramps, and endurance exercise intolerance.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1992

Cytochrome c oxidase deficiency and long-chain acyl coenzyme A dehydrogenase deficiency with Leigh's subacute necrotizing encephalomyelopathy.

A female infant was seen at the age of 2 months because of hypotonia, delayed motor development, and lactic acidosis, and she died at age 13 months due to respiratory failure. In a muscle specimen taken at 11 months and in a liver specimen obtained 1.5 hours postmortem, we found decreased activities of cytochrome c oxidase and long-chain acyl coenzyme A dehydrogenase. Neuropathological changes were typical for Leigh's subacute necrotizing encephalomyelopathy. To our knowledge, this is the first report of a combined defect of complex IV of the respiratory chain and of the long-chain specific acyl coenzyme A dehydrogenase of beta-oxidation in muscle and liver.

Acyl-CoA Dehydrogenase↗
PubMed1992

Becker muscular dystrophy: detection of unusual disease courses by combined approach to dystrophin analysis.

The rapid progress of research on the structure of the dystrophin gene has enormously increased our understanding of the molecular basis of Duchenne (DMD) and Becker (BMD) muscular dystrophy. Apart from "classical" clinical presentations, asymptomatic or only mildly affected individuals with deletions in the dystrophin gene have now been reported. We describe two families which were initially classified as metabolic myopathies, until the diagnosis of atypical BMD was established after dystrophin analysis at the protein and DNA level. A modern diagnostic approach to myopathies should, therefore, not only include morphological and biochemical investigations, but also be extended to the analysis of the dystrophin gene.

Adolescent↗
PubMed1992

Muscle pathology correlates with permanent weakness in hypokalemic periodic paralysis: a case report.

We present a morphological follow-up in a case of familial hypokalemic periodic paralysis with progressive weakness. At age 12 years muscle biopsy revealed mild vacuolar changes. Seventeen years later, after the patient had developed permanent weakness, light and electron microscopy disclosed tubular aggregates in about 15% of the fibers and medium-grade myopathic alterations. We describe correlation of muscle pathology with permanent weakness in hypokalemic periodic paralysis.

Child↗