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Biomedical subjects

H Somer

Publications and source records attributed to H Somer.

At least 55 records · Page 3Linked to original sources
PubMed1992

Nonvacuolar myopathy in a large family with both late adult onset distal myopathy and severe proximal muscular dystrophy.

Late adult onset distal myopathies usually show vacuolar degeneration as a characteristic feature in muscle pathology. In this study vacuolar degeneration was not present in 12 patients with late adult onset distal myopathy. All patients were members of a large kindred, with 26 patients showing this new form of distal leg myopathy. Additionally, a severely disabling proximal muscular dystrophy appeared in eight other members of the large consanguineous kindred. Muscle biopsies were obtained from clinically affected muscles, and from clinically unaffected muscles in patients with distal myopathy. For comparison specimens from various muscles of patients with severe proximal dystrophy were also studied. Histopathological changes correlating to muscular dystrophy were extensive in all muscles studied in patients with proximal dystrophy, and in tibial anterior muscles in patients with distal myopathy. Mild myopathic changes, mainly increased internal nuclei in muscle fibers, were detected in clinically unaffected muscles in the distal myopathy. The spectrum of findings is compatible with the hypothesis of previous clinical and genetic studies, indicating that the severe proximal dystrophy could be a homozygous manifestation of the dominantly inherited gene of the distal tibial muscle dystrophy.

Adult↗
PubMed1992

Disorders associated with multiple deletions of mitochondrial DNA.

Multiple deletions of mitochondrial DNA (mtDNA) have recently been described in a number of patients with neurological disorders. Most cases have been clinically characterized by autosomal dominant inheritance, adult onset, and a slowly progressive course with external ophthalmoplegia and muscle weakness. Some patients have had evidence of central or peripheral nervous system involvement or episodes of myoglobinuria. Muscle biopsy findings include ragged-red fibres (RRF), muscle fibres with absent COX-activity and abundant abnormal mitochondria with paracrystalline inclusions. Biochemically, a generalized reduction in the activities of mtDNA-encoded enzymes is observed in skeletal muscle. Southern blotting or PCR analysis reveal multiple populations of deleted mtDNA. The deletions occur at multiple sites between the replication initiation sites, involving a large portion of mtDNA, and most deletions seem to be flanked by direct sequence repeats, shown to be "hot spots" in the case of single large deletions. Apparently, a defect in a nuclear gene results in multiple deletions of mtDNA. Both clinical, genetic and molecular genetic observations indicate heterogeneity of this new disease category, apparently based on a disturbance in the "cross-talk" between the nuclear and the mitochondrial genomes.

DNA, Mitochondrial↗
PubMed1992

Reversible mitochondrial myopathy with cytochrome c oxidase deficiency.

Two siblings, a boy and a girl born in a nonconsanguineous marriage, presented with a similar clinical course. Sucking and breathing difficulties appeared within a few weeks of birth. Clinical examination revealed profound muscular hypotonia, hepatomegaly, increased serum creatine kinase activities, and lactic acidosis. Both infants were treated with gavage feeding, the boy also needing ventilatory support. Clinically they improved gradually. Now, the boy aged 4 years and the girl aged 28 months are free of clinical signs. Muscle biopsy specimens taken at 3 months showed, in both, ragged red fibres, abnormal mitochondria, and reduced cytochrome c oxidase (COX) staining. Biochemical analysis showed COX activity to be reduced to about 25% of the normal mean. The second biopsy specimen from the boy at 16 months was normal on morphological examination, but the girl's second specimen at 13 months still showed abnormal features. These cases are examples of the rare benign reversible COX deficiency. Early diagnosis is crucial to provide intensive treatment until spontaneous clinical improvement appears.

Biopsy↗
PubMed1992

Multiple deletions of mitochondrial DNA in several tissues of a patient with severe retarded depression and familial progressive external ophthalmoplegia.

Multiple deletions of mitochondrial DNA (mtDNA) have recently been reported in familial progressive external ophthalmoplegia (PEO), in a case of progressive encephalomyopathy, and in inherited recurrent myoglobinuria. The inheritance of familial PEO has been autosomal dominant, which indicates that a mutation in an unknown nuclear gene results in several mtDNA deletions of different sizes in these patients. We report a patient with autosomal dominant PEO, whose major clinical symptom, however, was severe retarded depression. The morphological analyses of the tissue samples derived from autopsy showed various abnormalities in the mitochondria in all the tissues studied. The activities of the respiratory chain enzymes encoded by mtDNA were remarkably reduced in the skeletal muscle. The mtDNA analyses confirmed that besides myopathy, this patient had a multisystem disorder with widespread distribution of multiple deletions of mtDNA. The highest percentage of mutated mtDNA was found in the brain, skeletal muscle and the heart, the relative quantity of mutated mtDNA correlating to the severity of the clinical symptoms.

Chromosome Deletion↗
PubMed1991

Muscular dystrophy with separate clinical phenotypes in a large family.

This report describes a large consanguineous family with muscular dystrophy in 23 patients showing intrafamilial variation of clinical expression. One main variant appeared in the first decade with proximal muscle weakness progressing over the next 20 years to wheelchair confinement, and appeared compatible with classical limb-girdle muscular dystrophy. The other main variant showed onset of distal muscle weakness in lower limbs in the third or fourth decade, progressing very slowly without greater disability throughout the lifetime. Tibial muscle weakness and wasting were clinical landmarks in this variant, but computed tomography of skeletal muscle revealed focal areas of fatty degeneration also in truncal, pelvifemoral, and distal leg muscles in a way not previously reported in distal myopathy. The overall difference in clinical findings between these main variants would suggest 2 separate genetic entities, genealogical data makes a common genetic background possible.

Adult↗
PubMed1991

Benign muscular dystrophy with autosomal dominant inheritance.

A slowly progressive myopathy was discovered in a family in four successive generations. Eight patients (four female, four male) from three generations were examined and they showed muscle weakness affecting predominantly proximal, but also distal, muscles. Two patients had unequivocal findings in childhood, the others showed myopathy in their twenties or thirties. Working ability was lost in physically demanding jobs in the thirties, but activities of daily living were still preserved. Elbow contractures, tight heel cords and contractures of the interphalangeal joints were frequent. Serum CK activity was usually mildly elevated and electromyographic examinations revealed myopathic changes. Histopathological changes were compatible with moderately advanced muscular dystrophy in two patients, the six others had mild myopathic changes.

Adult↗
PubMed1991

Imaging methods reveal unexpected patchy lesions in late onset distal myopathy.

Computed tomography (CT), ultrasonography (US) and low field magnetic resonance imaging (MRI) of muscles were performed in 13 patients of a large family with two clinically separate phenotypes of muscular dystrophy. Five patients had severe proximal muscle weakness and wasting like in limb-girdle muscular dystrophy. Imaging methods showed loss of muscle structure and replacement with adipose tissue especially in proximal muscles. Eight patients had distal myopathy of late onset with weakness and wasting of anterior tibial muscles. Imaging methods confirmed fatty degeneration of tibial muscles and, moreover, revealed unexpected large patchy lesions in several other clinically unaffected muscles. Our results indicate that some myopathies which are clinically localized, may actually have a more widespread patchy involvement as revealed by non-invasive imaging methods. In this family CT and MRI were more informative concerning lesions and distribution than US.

Adult↗
PubMed1991

Celiac disease, brain atrophy, and dementia.

We report 5 patients who developed dementia before age 60 and were subsequently found to have celiac disease (CD). Intellectual deterioration ranged from moderate to severe, and diffuse cerebral or cerebellar atrophy was found on brain CT. Diagnosis of CD was confirmed by findings of subtotal villous atrophy in jejunal biopsy specimens and positive serum reticulin and gliadin antibodies. Conspicuously, gastrointestinal symptoms were mild. The gluten-free diet failed to improve the neurologic disability except in 1 patient. CD is a multisystem disorder and may play a role in some cases of presenile dementia. Although the pathogenetic mechanisms are obscure, immunologic mechanisms are implicated.

Adult↗
PubMed1991

Diagnostic value of cerebrospinal fluid adenosine deaminase determination.

We measured the activity of adenosine deaminase (ADA) in the cerebrospinal fluid of 3 patients with tuberculous meningitis, 38 with viral meningitis, 15 with bacterial meningitis, 5 with malignant lymphoma, 11 with cerebrovascular diseases and 13 with miscellaneous neurological disorders. The highest ADA activities were observed in patients with tuberculous meningitis (median 21.3 U/l, range 20.0-23.0) and lymphoma (13.0 U/l, range 4.0-25.0). The sensitivity of the test for diagnosing tuberculous meningitis was 100% and the specificity 99% when a cut-off value of 20.0 U/l was used. We conclude that determination of ADA in cerebrospinal fluid is useful for the diagnosis of tuberculous meningitis, but that high activity also can be seen in some other CNS disorders, e.g. lymphoma with meningeal involvement.

Adenosine Deaminase↗
PubMed1990

Amyloid protein in familial amyloidosis (Finnish type) is homologous to gelsolin, an actin-binding protein.

Familial amyloidosis, Finnish type, is clinically characterized by cranial neuropathy and lattice corneal dystrophy. It is an autosomal dominant form of systemic amyloidosis with small deposits of congophilic material occurring in most tissues, particularly in association with blood vessel walls and basement membranes. Amyloid fibrils were extracted from the kidney of patient VUO, and rabbit antiserum raised against the 12 kDa purified amyloid subunit displayed strong immunohistochemical reactivity with the amyloid deposits. The amino terminal sequence of this 12 kDa amyloid protein (ATEVPVSWESFNNGD) showed homology with gelsolin (or actin depolymerizing factor), a 93 kDa plasma protein. The amyloid peptide is a degradation product, starting at position 173, of the gelsolin molecule.

Actins↗
PubMed1990

Linkage disequilibrium detected between dystrophia myotonica and APOC2 locus in the Finnish population.

Three polymorphic loci APOC2, CKMM and p134C were used to haplotype 15 Finnish dystrophia myotonica (DM) families representing about one third of all DM patients in this isolated population. Compound APOC2 and CKMM haplotypes reveal linkage disequilibrium: 90% of DM chromosomes co-occur with the haplotypes that occur in 31% of normal chromosomes only. The same disequilibrium is present when only polymorphisms occurring at the APOC2 locus are used. Surprisingly, no statistically significant linkage disequilibrium was discovered at the CKMM locus alone. Of the meiotic events, 84% were informative when both APO2 and CKMM loci were used. When studied selectively, 60% of meiotic events were informative at the APOC2 locus, whereas CKMM alone resulted in 65% meiotic informativeness. The distal marker p134C was found to have an unfortunately low information content in our population.

Alleles↗
PubMed1990

Genetic counselling in Duchenne and Becker muscular dystrophy is problematic when carrier studies give controversial results.

DNA-analysis with flanking and intragenic markers gave confusing results in 7 out of 74 (9.5%) Finnish families with Duchenne or Becker muscular dystrophy. In five families a sister or maternal aunt of the patient had elevated serum creatine kinase (CK) activity, although DNA-analysis indicated a low risk for carriership. In one family the two affected brothers had different pERT87 alleles. In one family the intragenic deletion found in a patient was not present in his mother, who was an obligatory carrier. Deletions were detected with cDNA probes in the probands in five of the families, but the controversy regarding carriership still remained. It is necessary to combine all available data from pedigree analysis, CK measurements, and DNA studies whenever carrier studies are performed, but it appears that major problems in counselling and prenatal diagnosis will still remain in a proportion of the families.

Adolescent↗
PubMed1990

Huntington disease in Finland: linkage disequilibrium of chromosome 4 RFLP haplotypes and exclusion of a tight linkage between the disease and D4S43 locus.

The question about heterogeneity of Huntington disease (HD) at the DNA level can be approached by analyzing the RFLP haplotypes formed by several RFLP loci of the diseased chromosome in different populations. In genetically isolated populations such as Finland, it is further possible to use this approach to test the hypothesis of a single mutation enriched in this population demonstrating an exceptionally low prevalence of HD. In this study covering 70% of all diagnosed HD cases in Finland, linkage disequilibrium of RFLP haplotypes of D4S10 and D4S43 loci polymorphisms was found. This phenomenon, not so far reported in any other population, could support the hypothesis of one ancestor HD mutation in the Finnish population. Despite the lower heterozygosity obtained with some RFLP markers, the proportion of individuals receiving informative DNA test results did not significantly differ from that reported in more mixed populations. In one HD family we established a recombination event between HD and the D4S43 locus, an event which can be highly useful in the more precise mapping of the HD gene.

Chromosome Mapping↗