Electrostimulation-induced changes in the enzyme activity pattern of dystrophic mouse muscles.
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Age Factors↗
Biomedical subjects
H Reichmann
Publications and source records attributed to H Reichmann.
A comparison of two ATPase based schemes for histochemical muscle fibre typing in various mammals.
A comparative study was performed on the fibre populations in tibialis anterior muscles of mouse, rat, guinea pig, rabbit, cat and dog using the two different methods of histochemical staining for myofibrillar ATPase after acid (Brooke and Kaiser 1970) or alkaline preincubations (Guth and Samaha 1970). For all species a complete correspondence existed between type I (Brooke and Kaiser 1970) and beta fibres (Samaha et al. 1970). Gross correspondence (greater than 85%) existed between IIA and IIB (Brooke and Kaiser 1970) and alpha beta and alpha fibres (Samaha et al. 1970) respectively in mouse, guinea pig, rabbit, cat and dog. In the case of mouse and dog, this high degree of correspondence was based on the assumption that mouse tibialis anterior contains no type I and the dog no type IIB fibres. For the rat, a pronounced overlap existed between IIA fibres on the one hand and alpha beta and alpha fibres on the other hand as well as between IIB fibres and alpha beta and alpha fibres. These observations lead to the conclusion that the two classification schemes are not interchangeable for all species and that the two terminologies should be used only in relation with the methods from which they were derived.
Adenosine Triphosphatases↗
A comparative microphotometric study of succinate dehydrogenase activity levels in type I, IIA and IIB fibres of mammalian and human muscles.
Activity levels of succinate dehydrogenase (SDH) were determined kinetically by means of comparative microphotometric measurements in situ. Activities were correlated with fibre types classified histochemically according to Brooke and Kaiser (1970). Analyses of tibialis anterior muscles in the mouse, rat, guinea pig, rabbit, cat and the human showed pronounced variations in the activity profiles of type I, type IIA and IIB fibres of these muscles. Large scattering of enzyme activity existed in three fibre populations. Overlaps of varying extent were found for the SDH profiles between the different muscles. Type I fibres reveal species differences in aerobic oxidative capacity. Whereas the majority of the IIB fibres in rabbit muscle tended to be low in SDH activity, the main fraction of this fibre population was characterized by high activities in mouse muscle. Similarly, the IIA fibre populations revealed opposite properties in mouse and rabbit muscles. These extremes as well as intermediate activity patterns indicate that no general scheme exists according to which the histochemically assessable myosin ATPase is correlated with the aerobic oxidative capacity of muscle fibres in various mammalian muscles.
Adolescent↗
A method for quantitative extraction of enzymes and metabolites from tissue samples in the milligram range.
A method is described for quantitative extraction of soluble enzyme activities from tissue samples in the milligram range. Mechanical disintegration of the frozen tissue is performed in a micromortar from which the powdered tissue can be quantitatively transferred for extraction in small volumes within a microcentrifuge tube.
Animals↗
Effects of low frequency electrical stimulation on enzyme and isozyme patterns of dystrophic mouse muscle.
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Alcohol Oxidoreductases↗
The principle of determining relative enzyme activities by comparative kinetic microphotometry in situ.
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Animals↗
Mitochondria-related encephalomyopathies.
Owing to advances in morphological and biochemical techniques, the mitochondria-related myopathies and encephalomyopathies have emerged as a still rapidly growing group of primary and secondary metabolic disorders, which may extend from infancy to late adulthood. Impairment of the biochemically diversified mitochondria is reflected in an enormous number of deficiencies, often affecting several mitochondrial enzymes in the same patient; morphologically abnormal mitochondria are common and are thus not specific to individual mitochondrial enzyme deficiencies. Skeletal muscle biopsies have provided a wealth of data through histological and histochemical studies and from isolated mitochondria. As a similar abundance of biochemical and morphological findings has not been obtained from brain tissue in mitochondrial encephalomyopathies, investigation of these disorders is still in its infancy; interpretation of these conditions and their encephalopathic components has largely been based on comparison of data not derived from brain tissues. Therefore, it has been, and still is, largely the link between an encephalopathy and an associated mitochondrial myopathy that identifies the brain lesions as clinical and morphological expressions of a mitochondrial defect. As enzyme histochemical and electron microscopic investigations of mitochondrial encephalopathies have not yielded a comparable rich spectrum of morphological findings, it is conceivable that the spectrum of mitochondrial encephalopathies may be much larger than defined by the hitherto identified encephalomyopathies. This may be especially so when the myopathic component is of minor nosological significance.
Brain Diseases↗
Noninvasive assessment of the circle of Willis in cerebral ischemia: the potential of CT angiography and contrast-enhanced transcranial color-coded duplexsonography.
Thirty-four patients with acute hemispheric ischemic strokes underwent both CT angiography and contrast-enhanced transcranial color-coded duplexsonography (TCCD) to study the effectiveness of the combined noninvasive techniques for evaluation of the circle of Willis. In 3/34 patients, CT angiography and contrast-enhanced TCCD demonstrated middle cerebral artery (MCA) occlusion, in 5 others MCA stenosis. A severe posterior cerebral artery stenosis was missed by CT angiography. In 8 patients, contrast-enhanced TCCD failed because of poor bone windows. In these patients, CT angiography was normal. CT angiography and contrast-enhanced TCCD are complementary noninvasive diagnostic tools. Disagreements between the diagnostic findings of these methods still need further evaluation by digital subtraction angiography.
Aged↗
Processing of artificial peptide-DNA-conjugates by the mitochondrial intermediate peptidase (MIP).
Import of DNA from the cytoplasm into the mitochondrial matrix is an obligatory step for an in organello site-directed mutagenesis or gene therapy approach on mitochondrial DNA diseases. In this context, we have developed an artificial DNA translocation vector that is composed of the mitochondrial signal peptide of the ornithine transcarbamylase (OTC) and a DNA moiety. While this vector is capable of directing attached passenger molecules to the mitochondrial matrix, the recognition of this artificial molecule by the endogenous mitochondrial signal peptide processing machinery as well as the cleavage of the peptide plays a pivotal role in the release of the attached DNA. To study the proteolytic processing of the artificial vector, various signal peptide-DNA-conjugates were treated with purified mitochondrial intermediate peptidase. When the leader peptide is directly linked to the DNA moiety without an intervening spacer, MIP processing is prevented. Cleavage of the peptide can be restored, however, when the first ten amino acid residues of the mature part of OTC are appended at the carboxy-terminal end of the signal peptide. Our results show that artificial peptide-DNA-conjugates are recognized by the mitochondrial proteolytic machinery, and therefore an interference of the peptide with the DNA function can be excluded.
Amino Acid Sequence↗
Mitochondrial changes in muscle phosphoglycerate kinase deficiency.
X-linked phosphoglycerate kinase (PGK) deficiency is a rare disorder which affects the glycolytic pathway and leads to reduced ATP production. Clinically, PGK deficiency is often associated with nonspherocytic hemolytic anemia and symptoms caused by disturbances of the central nervous system. In addition, myopathy characterized by weakness, cramps, intolerance to exercise, and myoglobinuria has been described in a few cases. We here report on a 23-year-old man who presented with episodes of muscular weakness, cramps, rhabdomyolysis, and renal failure induced by intensive physical exercise. Biochemical analysis of muscle specimens disclosed markedly reduced PGK activity (11.5% compared to normal controls). A moderate increase of glycogen was seen in numerous muscle fibers. Mitochondria in muscle fibers and endothelial cells showed accumulations of glycogen. In muscle fibers unusually large matrix granules were present in several mitochondria. A sural nerve biopsy disclosed scattered large hypomyelinated axons without evidence of demyelination and remyelination. These findings indicate involvement of mitochondria in this case of symptomatic PGK deficiency.
Adult↗