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Myasthenia gravis and mitochondrial myopathy may present with similar clinical symptoms as inconstant palpebral ptosis, ophthalmoparesis, and muscle weakness. A few case initially diagnosed as myasthenia gravis by a positive decremental response on EMG and successful anticholinesterase therapy revealed to be affected by mitochondrial disease. We report a new case initially found to be affected by myasthenia gravis in whom muscle biopsy, performed because of symptom worsening, disclosed a mitochondrial myopathy. It is not clear if the association of mitochondrial myopathy and myasthenia gravis is coincidental or if there is a pathogenic link between the two pathologies. We suggest that muscle biopsy should be performed in cases with atypical myasthenia gravis signs.

Ataxia-telangiectasia (AT) is an autosomal recessive disease characterized by neurodegeneration and immunodeficiency. Hypersensitivity to radiation and chromosome instability are the biological markers of this disease. The gene responsible for AT (ATM), has been identified on chromosome 11q22-23; it encodes a large polypeptide partially homologous to the phosphatidylinositol (PI) 3-kinase family. PI 3-kinase is a protein family playing an important role in the prevention of apoptosis. In order to investigate the apoptosis pathway, we tested peripheral blood cells from AT patients and controls exposed to 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis in human quiescent lymphocytes, probably through oxidative damage. Our results show that the response to dRib-induced apoptosis is significantly more elevated in AT cells than in control cells, suggesting that the apoptotic process plays a role in the pathogenesis of AT disease.

Dose-dependent water exchange times and intracellular water contents were measured by NMR (nuclear magnetic resonance) in erythrocytes and mitochondria interacted with the anti-anginal and anti-arrhytmic agent, amiodarone. Addition of the drug up to 26 microM yielded 80% enhancement of the water exchange rate in erythrocytes at 37 degrees C and 41% enhancement at 22 degrees C with 40% and 9%, respectively, increases in the intracellular water content. Similar enhancements were obtained in mitochondria at 22 degrees C. The data suggests a somewhat higher affinity of amiodarone to mitochondrial than to erythrocyte membranes.

We report the analysis of plasma levels of vitamin E that has been found normal in 20 italian patients with Parkinson's disease (PD) confirming the previously reported results from other groups. We discuss the literature data about the possible protective effect of antioxidant agents in the PD and generally in the aging processes.

In two unrelated patients with Niemann-Pick type C disease MRI showed symmetrical cerebral and cerebellar atrophy and hypoplasia of the corpus callosum. T2-weighted images in one showed high signal areas in the posterior white matter.

We describe two new polymorphic sites identified by DdeI digestion of human mitochondrial D-Loop DNA. Their frequencies were estimated on a random group of 54 unrelated blood donors, born and descending from female ancestors of the Province of Reggio Emilia (Central Emilia, Northern Italy). These newly detected polymorphisms were generated by A to G transitions at positions 16300 and 16482 of mt-DNA. They were found at a 5% frequency in our sample whereas the remaining 95% of the sample exhibited a Cambridge sequence restriction pattern.

A series of cases of epilepsy with associated bilateral occipital calcifications (EBOC) without signs of phakomatosis and without any disorders known to produce cerebral calcifications have been reported. It is unclear whether EBOC is an incomplete variant of Sturge-Weber disease (SWD) or if it is a different, as yet undefined encephalopathy. We describe four new cases of EBOC that are different clinically by age of onset, type, course, severity of epilepsy, and associated cognitive deficits but that are linked by similar neuroradiologic findings. Similar to cases described in the literature, there is convincing evidence in favor of the hypothesis that these cases belong to an encephalopathy different from SWD and frequently associated with celiac disease.

This investigation sought to determine which collimation factors were most important in providing superior image quality with a three-headed SPECT device. The relationship between sensitivity, resolution and SPECT image quality was studied. Two different sets of parallel-hole collimators were used. The ultrahigh-resolution collimators have higher spatial resolution (8.9 versus 11.0 mm), but only 55% of the sensitivity of the high-resolution collimators. A phantom with hot rods was imaged with both collimator sets. Observers compared images with the ultrahigh-resolution collimators to images of varying counts with the high-resolution collimators and determined which high-resolution images matched the ultrahigh-resolution images in image quality. Eleven patient studies were acquired with both collimator sets for equal time, and observers chose which image set they preferred. Transverse images of brain and liver studies were simulated with varying resolution and counts and subjectively compared. The phantom study indicated that the improvement in resolution led to image quality comparable to increasing the number of counts by a factor of 2.5 to 3.4. The clinical studies showed that the ultrahigh-resolution collimators were preferred in a large majority of the cases. These trends were also seen in the simulation study. These results confirm that higher resolution collimators should be used with multihead SPECT devices. The improvement in resolution more than compensates for the loss in sensitivity, leading to an overall improvement in image quality.

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.

Here we report a family in which the Gorlin's syndrome or oculo-dento-digital dysplasia is transmitted with autosomal dominant inheritance of variant expressivity. Three cases, extensively studied, show also slight oligophrenia, symptom rarely described in this syndrome.

The congenital cystic adenomatoid malformation (MACP), represents the congenital lung malformation most frequent in pediatric age. After examining the embryology, the treatment and the evolution of the malformation we wish to report our experience of four cases of MACP in patients 2 month, 1, 2 and 3 years of age. Lobectomy has cured all patients with the exception of one; this child had a MACP of the lung associated with Rhabdomyosarcoma and died after one and half year of chemotherapy.

We report the results on the serum vitamin E amount in Friedreich's and other inherited ataxias. Subnormal serum vitamin E values have been found confirming a possible involvement of this vitamin in the pathogenesis of the ataxic syndromes.