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Biomedical subjects

A Federico

Publications and source records attributed to A Federico.

At least 163 records · Page 9Linked to original sources
PubMed1993

Choreo-acanthocytosis like phenotype without acanthocytes: clinicopathological case report. A contribution to the knowledge of the functional pathology of the caudate nucleus.

Detailed clinical and neuropathological findings in two unrelated patients with a chorea-acanthocytosis-like phenotype (CA) are reported. One case met all the diagnostic criteria of CA and had a deceased brother with the same disease. The second case had a virtually identical phenotype to the former but without acanthocytes. These findings suggest that both patients are affected by the same disease and that acanthocytes are not essential to the diagnosis. Neuropathological autopsy studies on the brain of the second case showed selective atrophy of the caudate nucleus that seemed to correspond to the movement disorder and behavioural abnormalities prominent in this patient. In both subjects, morphometric and ultrastructural examination of the peripheral nerve showed loss of myelinated fibres, more accentuated distally, and cytoskeletal changes in the axoplasm. These findings support the hypothesis that peripheral neuropathy in CA is caused by distal axonopathy.

Acanthocytes↗
PubMed1993

The teaching of neurology in the degree course in dentistry.

The problem of neurology teaching in the degree course in dentistry is addressed in the light of data gathered from teachers of the course. The first part of the paper deals with the teachers and the organization of the course, the second with the teaching objectives and relations with other disciplines and the third with the reform hypothesis of Table XVIII bis and the role of neurology in the curriculum of the dentistry school. The last part examines the assessment of teachers by students and the repercussions of improved teaching on attendance and attainment.

Education, Dental↗
PubMed1993

Cerebrotendinous xanthomatosis: pathophysiological study on bone metabolism.

A condition of osteopenia in some cerebrotendinous xanthomatosis (CTX) patients led us to investigate bone metabolism in 8 patients belonging to 5 families. Serum calcium, phosphate and vitamin D metabolites were in the normal range; a reduction in total body density and impairment of intestinal radiocalcium absorption were found in the majority of our patients.

Absorptiometry, Photon↗
PubMed1993

Sensory-motor hereditary neuropathy with early onset. A case report.

The early onset sensory motor hereditary neuropathy (HSMN) can be divided into two forms: the early onset type (HSMN type III or Dejerine-Sottas) and the congenital hypomyelinating neuropathy (CHN). In both cases, abnormalities of myelination are present in peripheral nerves. Symptoms include hypotonia, weakness, hypotrophy, and areflexia. Skeletal changes may be present. In CHN symptoms may be present at birth and are rapidly progressive. Many authors actually consider the two forms different. The diagnosis is based only on clinical and neuropathological criteria. Here we report a case with a typical phenotype of HSMN type III but with peripheral nerve bioptic findings suggesting a CHN.

Adolescent↗
PubMed1992

Dementia, myoclonus, peripheral neuropathy, and lipid-like material in skin biopsy during psychotropic drug treatment.

Chronic treatment of humans with several drugs is associated with lesions resembling lipidosis in different tissues. Recently, a Creutzfeldt-Jacob-like syndrome has been observed during tricyclic antidepressant therapy, but no evidence of interaction of these drugs with lysosomal function has been reported during such treatment. We report a case of dementia, myoclonus, peripheral neuropathy, and lipid storage in the skin due to antidepressant drug therapy, in which the discontinuation of drugs resulted in an improvement of clinical and electrophysiologic signs together with reduction of morphological evidence of lipid lysosomal storage.

Biopsy↗
PubMed1992

Heterogeneity in ataxia-telangiectasia: classical phenotype associated with intermediate cellular radiosensitivity.

We identified a subgroup of ataxia-telangiectasia (AT) patients (2 sibs and 1 unrelated case) characterized by typical clinical manifestations of the disease and cellular radiosensitivity intermediate between classical AT and normal subjects. Our data and a literature review of the intermediate radiosensitivity AT cases show that radioresistant DNA synthesis, cellular radiosensitivity (measured in terms of survival and chromosome breakage), and the clinical hallmarks behave independently. This raises a number of interesting questions about the correlation between radiobiological and clinical features, and about the nature of the AT gene(s).

Adolescent↗
PubMed1992

Evoked potentials in cerebrotendinous xanthomatosis and effect induced by chenodeoxycholic acid.

Evoked potentials are reported in 10 patients with cerebrotendinous xanthomatosis, eight of whom had peripheral neuropathy. Four subjects showed delayed N13 to N20 interpeak latencies for arm somatosensory evoked potentials, and five showed moderately prolonged I to III and I to V interpeak latencies of brain-stem auditory evoked potentials. Six of seven patients showed marked delay and desynchronization of visual evoked potentials. All five patients undergoing transcutaneous magnetic stimulation of the motor cortex presented greatly delayed central motor conduction time, especially of the lower limbs. After treatment with chenodiol (750 mg/d for at least 2 years), there was a significant improvement in nerve conduction velocities, N13 to N20 interpeak latencies, and visual evoked potential latencies. Brain-stem auditory evoked potentials remained unchanged.

Adult↗
PubMed1992

Imipramine induced lipidosis and dexamethasone effect: morphological and biochemical study in normal and chronic GM2 gangliosidosis fibroblasts.

A large heterogeneous group of lysosomotropic compounds with a common cationic amphiphilic structure induces in vitro and in vivo lysosomal lipid storage. The biochemical mechanism underlying the lipidosis is still the subject of investigation. The authors report the experimental effect of imipramine and dexamethasone on lysosomal system in cultured skin fibroblasts. Morphological and ultrastructural observations of cells treated with imipramine showed vacuoles with lipidic storage, enlarged lysosomes with electron translucent zones and normal appearance of all the other cytoplasmic organelles. The lysosomal enzyme activities were decreased on biochemical study. On the contrary, an increased enzyme activity was detected in the culture medium. Pretreatment with dexamethasone partially prevented the effect of imipramine. Our results suggest that tricyclic antidepressants may induce lysosomal lipidosis through a dysfunction in the recycling of mannose-6-phosphate receptors and in the trafficking of newly synthesized lysosomal enzymes. Moreover the data presented may provide a clue in understanding some of the side effects observed in patients chronically treated with antidepressant drugs.

Cells, Cultured↗
PubMed1992

Variability of the expression of muscle mitochondrial damage in ocular mitochondrial myopathy.

In this study we comparatively analysed deltoid histochemistry, biochemistry and mitochondrial DNA (mtDNA) in two groups of ten sporadic ocular mitochondrial myopathies (OMM), respectively with and without ragged red fibres (RRF). (1) All but one RRF--patients presented the mild form of OMM with blepharoptosis but without ophthalmoplegia; (2) the occurrence of cytochrome c oxidase deficient (COX-) fibres was significantly higher in the RRF+ group, but four RRF- cases also showed COX- fibres; (3) no difference was observed in biochemical findings between the groups; (4) two RRF- patients without COX- fibres showed mtDNA heteroplasmy; (5) in two RRF- patients without deltoid mtDNA deletion, biopsy of an eyelid muscle showed significant mitochondrial alterations. These results suggest that the expression of a mitochondrial defect can vary and that the absence of RRF in a skeletal muscle biopsy does not necessarily rule out the diagnosis of OMM, if other data support that.

Adolescent↗
PubMed1992

Magnetic resonance imaging findings in Leber's hereditary optic neuropathy.

The authors describe magnetic resonance imaging (MRI) findings in 15 subjects with different clinical stages of Leber's disease. A few and no characteristic abnormalities of the optic nerve signal were found. Nevertheless, MRI can be considered as a useful tool to differentiate optic neuritis together with visual and brainstem auditory evoked potentials.

Adolescent↗
PubMed1992

[Aortic stenosis and coronary pathology. Their implications for the transvalvular gradient].

To assess the incidence of coronary artery disease in patients with valvular aortic stenosis and its implication on peak systolic valvular gradient, 31 consecutive patients who underwent cardiac catheterization were examined. Associated significant coronary artery disease (> 50% reduction in luminal diameter evaluated in proximal segments and right dominant circulation) was present in 54.8% of patients. There was no difference in the distribution of risk factors among patients with and without significant luminal narrowings. The prevalence of coronary artery disease was found not to be significantly correlated with age (p = 0.276). There was no relationship between typical angina pectoris and the presence of coronary artery disease (p = 0.063). Fourty-seven percent of cases resulted free of chest pain. Ejection fraction was found to be significantly lower in patients with coronary artery disease (45 +/- 14.2%) than in patients without coronary artery disease (65.1 +/- 3.9%; p = 0.03) and a reverse relationship was observed between the presence of coronary artery disease and peak systolic valvular gradient (p = 0.006) which, in turn, correlated significantly with ejection fraction (r = 0.68; p = 0.023). These data demonstrate that the value of peak systolic valvular gradient, as the only index for the evaluation of the severity of aortic stenosis, is greatly limited in patients with associated coronary artery disease. Moreover, confirming the guidelines of the American College of Cardiology and of the American Heart Association task force, these data also stress the necessity of performing coronary angiography regardless angina pectoris is present or not.

Aged↗
PubMed1991

Diagnosis and pathogenesis of late-onset genetic metabolic encephaloneuromyopathies.

The strategy of clinical investigations for the diagnosis of the late-onset neurometabolic diseases is reported. The criteria for the diagnostic suspicion are inheritance and multisystem involvement. The different clinical signs that are the basis for further biological investigations are reviewed. The diagnostic confirmation will be obtained by laboratory analyses, some of which can be easily performed in all hospitals. The pathogenesis of late-onset neurometabolic encephaloneuromyopathies and the clinical consequences of heterozygosity are reported. Finally these disorders are discussed as a useful model for understanding the pathogenesis of some of the most common neurological diseases and of the normal functions of many molecules in the nervous system.

Brain Diseases, Metabolic↗
PubMed1991

The clinical aspects of adult hexosaminidase deficiencies.

The authors describe the clinical phenotypes of hexosaminidase deficiencies (GM2 gangliosidosis). The symptoms, differently combined, include cerebellar ataxia, motor neuron disease, dystonia, psychosis, neurovegetative troubles with different severity. Morphological changes are evident in rectal, muscle or nerve biopsies. Minor clinical changes are described in carriers from a family. A chronic GM2 gangliosidosis has to be suspected in any atypical case with the above-mentioned symptoms with autosomal-recessive inheritance.

Adolescent↗
PubMed1991

Cherry-red spot myoclonus syndrome (type I sialidosis).

The authors report the sequence of the clinical symptoms in type I sialidosis or cherry-red spot myoclonus syndrome, derived from the cases personally observed and from the literature. They also report neuropathological and neurochemical data. A serial EEG study in a case shows the tendency to a progressive deregulation of cerebral electric activity. Therapeutic attempts to reduce myoclonus, which is one of the more disabling symptoms in this syndrome, are described.

Adolescent↗