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D Pongratz

Publications and source records attributed to D Pongratz.

At least 109 records · Page 6Linked to original sources
PubMed1991

A specific point mutation in the mitochondrial genome of Caucasians with MELAS.

The mitochondrial DNA (mtDNA) of Japanese patients suffering from the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) exhibits a specific heteroplasmic A----G transition in the tRNA(Leu) at position 3243. In this study, we investigated mtDNA from skeletal muscle, cardiac muscle, brain, liver, diaphragm, fibroblasts and blood cells of four Caucasians with MELAS, one younger healthy sister of two MELAS patients, and eleven controls. We found that 1) the mutation was present in all investigated tissues of Caucasians with MELAS but not in controls, 2) within a single patient, the tissue-specific variation of the copy number of mutated mtDNA covered the same range as in the skeletal muscle of different patients, 3) the mutation was also present in the blood cells of the healthy sister of two MELAS siblings.

Acidosis, Lactic↗
PubMed1991

Type 2a fibre rhabdomyolysis in myoadenylate deaminase deficiency.

A 31-year-old woman developed an acute, potentially fatal rhabdomyolysis of undetermined origin. Muscle biopsy revealed selective lysis involving exclusively type 2a fibers. Myoadenylate-deaminase (MAD) deficiency was proven by a negative histochemical reaction as well as by an enzymatic biochemical determination. The significantly greater energetic dependence of type 2a fibres on MAD explains their selective damage. The patient's mother also suffers from a similar muscle disease of still unclarified origin.

AMP Deaminase↗
PubMed1990

Mitochondrial myopathies: divergences of genetic deletions, biochemical defects and the clinical syndromes.

Genomic Southern analysis of muscle mitochondrial (mt) DNA from 16 patients with mitochondrial myopathies was performed; 14 of 16 patients had chronic progressive external ophthalmoplegia (CPEO), while 2 patients had mitochondrial myopathies without CPEO. Eleven patients with CPEO, including 5 who exhibited the complete triad of symptoms characteristic of the Kearns-Sayre syndrome (i.e. CPEO, retinal degeneration and heart block) had heteroplasmic mtDNA with deletions ranging from 2.0 to 8.0 kb in length. There was no clear-cut correlation between the size and location of the deletions, on the one hand, and the histochemical and biochemical data or the severity of the disease, on the other.

Adolescent↗
PubMed1990

Mutations of the mitochondrial DNA: the contribution of DNA techniques to the diagnosis of mitochondrial encephalomyopathies.

We performed restriction analysis and Southern blotting of the muscle mitochondrial DNA from 34 patients suffering from different myopathies. In 13/21 patients with chronic progressive external ophthalmoplegia the muscle mitochondrial DNA was shown to be heteroplasmic. Further mapping by use of several restriction enzymes yielded large deletions in muscles from 10/13 chronic progressive external ophthalmoplegia patients. Most of the deletions spanned large parts of the mitochondrial genome, leading to loss of mitochondrial genes encoding several subunits of the respiratory chain complexes I (NADH-dehydrogenase), IV (cytochrome c oxidase) and V (ATP-synthetase), as well as of several tRNAs. Comparison of the mapping data with the histochemical and biochemical results did not provide a clear correlation between the location of the mitochondrial genetic defects and the functional deficiencies of the affected respiratory chain complexes. In the majority of patients with chronic progressive external ophthalmoplegia, but without a family history of the disease, restriction analysis reveals large mutations of the mitochondrial genome, while other methods are necessary for the localization of defects in all cases with maternal transmission of the disease. The same holds true for all other kinds of mitochondrial myopathies based on defects within the nuclear DNA or on derangements of the "cross-talk" between the nuclear and the mitochondrial genomes.

Adult↗
PubMed1990

[Muscular pain].

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Diagnosis, Differential↗
PubMed1989

Fatal mitochondrial myopathy with cytochrome-c-oxidase deficiency and subunit-restricted reduction of enzyme protein in two siblings: an autopsy-immunocytochemical study.

Lack of cytochrome-c oxidase activity and of cytochromes aa3 + b has been reported previously in the skeletal muscle of one of two siblings (Müller-Höcker et al, 1983). The present study reports a deficiency of immunoreactive enzyme protein in the skeletal muscle of both siblings, who had an identical fatal clinical course. In all specimens the defect did not involve the whole enzyme protein, but was selectively expressed in the mitochondrially derived subunits II/III and nuclear coded subunits VIIbc. Neither the specific fibers of the muscle spindles nor the mitochondria of the heart, liver, kidneys, vessel walls and/or gastrointestinal tract were affected. These results are most consistent with a primary nuclear defect being responsible for the organ specific and subunit selective expression of the enzyme defect.

Antibodies↗
PubMed1988

Autosomal dominant Emery-Dreifuss syndrome: evidence of a neurogenic variant of the disease.

The first German family with autosomal dominant Emery-Dreifuss syndrome (EDS) is described, with electrophysiologic and myopathologic results providing evidence of a primary neurogenic disease. According to classification of the scapulo peroneal syndrome without cardiomyopathy, we conclude that there are two variants of EDS: one myopathic, the other neurogenic in origin. Therefore, the term Emery-Dreifuss muscular dystrophy should be avoided. Instead, each case of EDS should be classified as myopathic or neurogenic with X chromosome recessive or autosomal dominant inheritance.

Adolescent↗
PubMed1987

[Dominant autosomal humeroperoneal syndrome with early contractures and cardiomyopathy (Emery-Dreifuss syndrome)].

At least seven members of a family coming from southern Germany (Franconia) have manifested Emery-Dreifuss syndrome within four generations. This syndrome is characterized by slowly progressing atrophic pareses, generally in a humeroperoneal distribution, premature joint contracture, and cardiomyopathy with reduction of functional capacity. Up to now four members of this family have died from cardiac causes between the age of 39 and 46 years. Three family members have now been thoroughly examined; they showed typical muscular atrophies and contractures. The two older patients were diagnosed as having a cardiomyopathy with a complete atrioventricular block and ventricular tachycardia. Electromyographic and histological findings indicate a primary neurogenic process. Regular cardiological examinations combined with effective therapy (for example, implantation of a cardiac pacemaker and treatment with antiarrhythmic drugs) will be necessary in treating the serious arrhythmias. Progressive myocardial insufficiency required heart transplantation in one of our patients, which was successfully performed. Macroscopic and microscopic examination of the explanted heart showed a dilatative cardiomyopathy with hypertrophy and dilatation of both atria and ventricles, differences in the diameters of individual heart muscle cells, and a predominately focal interstitial fibrosis.

Adolescent↗
PubMed1987

Congestive heart failure due to mitochondrial cardiomyopathy in Kearns-Sayre syndrome.

Despite extensive analysis of the ultrastructural changes in skeletal muscle fibers in chronic progressive external ophthalmoplegia (CPEO), similar changes in the heart muscle fibers of patients with cardiac involvement in CPEO, called Kearns-Sayre syndrome, have not been described in detail. We report the clinical long-term course in a patient with Kearns-Sayre syndrome in whom mitochondrial cardiomyopathy was suspected in vivo and was confirmed at autopsy as the underlying cause of severe dilative cardiomyopathy. Enlarged, abnormally structured, excessively augmented mitochondria and loss of myofibrils could be shown both in skeletal and heart muscle cells.

Adult↗
PubMed1987

[Diagnosis of susceptibility to malignant hyperthermia using the in vitro contracture test].

Though a malignant hyperthermia (MH) crisis is still a critical event during general anesthesia, recent developments in prophylaxis and treatment should help in avoiding fatal episodes. The best means to avoid MH episodes would be early recognition of MH susceptibility. Today the only reliable test to identify MH susceptibility is the in vitro contracture test. Thus, to diagnose MH susceptibility we performed this test on muscle biopsies from 26 individuals who: (1) had an event during general anesthesia that may have been indicative of MH (4 patients); (2) had a family member with a medical history of MH (20 patients); or (3) had unexplained elevated CK levels (1 patient). The criteria according to which patients were submitted to the testing are shown in detail in Table 1. We used the standardized version of the contracture test that has been proposed by the European Malignant Hyperpyrexia Group. Muscle biopsies (20-30 mm long, 8 mm diameter) were dissected into 8-10 small bundles (2-3 mm diameter) and tested within 3 h post-biopsy in four independent tissue baths with various concentrations of caffeine or halothane. According to the concentration of caffeine or halothane necessary to elicit contractures exceeding a predefined force threshold (20 mN), it was possible to classify the patients as MHS (MH-susceptible), MHE (equivocal), or MHN (negative). In addition to the in vitro test, clinical, laboratory, and neurophysiological data were collected from these patients and correlated with the individual test results (Table 2). Thirteen patients were classified as MHS, five were MHE, and seven patients MHN (Fig. 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Myoadenylate deaminase deficiency: successful symptomatic therapy by high dose oral administration of ribose.

A 55 years old patient suffering from exercise-induced muscle pain and stiffness due to primary myoadenylate deaminase deficiency has been successfully treated with D-ribose since 1984: single doses of 4 grams administered at the beginning of exercise prevented the symptoms completely; on continuation of exercise this dose had to be repeated all 10-30 min. Total doses of 50-60 g per day were tolerated without side-effects.

AMP Deaminase↗
PubMed1986

Fatal mitochondrial cardiomyopathy in Kearns-Sayre syndrome.

The clinical and postmortem findings in a 26 year old man with Kearns-Sayre syndrome are described. In the last years of his life he suffered from cardiac arrhythmias and a congestive cardiomyopathy, dying of cardiac pump failure. The heart was enlarged, especially the left ventricle which was fibrotic and excessively dilated. Histological and fine structural investigation revealed an excessive loss of myofibrils and an increase of enlarged mitochondria with lamellar and atypically tubular cristae in widespread heart muscle cells. Mitochondrial anomalies were also observed in some cells of the conductive system. This patient thus suffered not only from a mitochondrial myopathy with ragged red fibers but also from a fatal mitochondrial cardiomyopathy. The anomalies observed in the mitochondria of the conductive system cells suggest that the well-known conductive abnormalities in patients with Kearns-Sayre syndrome might be at least partly caused by disturbed function of these mitochondria.

Adult↗