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V Sansone

Publications and source records attributed to V Sansone.

47 records · Page 3Linked to original sources
PubMed1992

[Locoregional anesthesia for surgical arthroscopy of the knee].

A new technique for regional anaesthesia for arthroscopy of the knee is presented. The method includes sciatic nerve block according to the technique proposed by Labat, through a posterior approach and the block of the femoral and lateral cutaneous nerves using a single anterior approach. Results obtained in 30 patients are presented: they include good stability of the cardiovascular and respiratory parameters, high efficiency and duration of anaesthesia resulting in a satisfactory surgical procedure.

Adult↗
PubMed1991

Inhibitory action of acetylcholine, baclofen and GTP-gamma-S on calcium channels in adult rat sensory neurons.

High- and low-voltage activated calcium channel currents (HVA and LVA) were inhibited by acetylcholine (10-100 microM) and baclofen (10 microM) in adult rat sensory neurons. This modulatory effect was present on dihydropyridine (nifedipine 1 microM) and/or omega-conotoxin (3.2 microM, 2-5 h incubation) insensitive components and was insensitive to holding potentials (Vh -50 to -90 mV). GTP-gamma-S (100 microM) prolonged calcium channel current activation in a time- and voltage-dependent manner. On the other hand, the current amplitude reduction induced by muscarinic and GABAB receptor activation, was not relieved by a 50-ms conditioning prepulse to +50 mV. This suggests the possibility of an alternative voltage-independent modulation mechanism.

Acetylcholine↗
PubMedDate not supplied

Biomolecular identification of (CCTG)n mutation in myotonic dystrophy type 2 (DM2) by FISH on muscle biopsy.

Myotonic dystrophy type 2 (DM2) is a dominantly inherited disorder with multisystemic clinical features, caused by a CCTG repeat expansion in intron 1 of the zinc finger protein 9 (ZNF9) gene. The mutant transcripts are retained in the nucleus forming multiple discrete foci also called ribonuclear inclusions. The size and the somatic instability of DM2 expansion complicate the molecular diagnosis of DM2. In our study fluorescence-labeled CAGG-repeat oligonucleotides were hybridized to muscle biopsies to investigate if fluorescence in situ hybridization (FISH), a relatively quick and simple procedure, could be used as a method to diagnose DM2. When FISH was performed with (CAGG)5 probe, nuclear foci of mutant RNA were present in all genetically confirmed DM2 patients (n=17) and absent in all patients with myotonic dystrophy type 1 (DM1; n=5) or with other muscular disease (n=17) used as controls. In contrast, foci were observed both in DM1 and DM2 myonuclei when muscle tissue were hybridized with (CAG)6CA probe indicating that this probe is not specific for DM2 identification. The consistent detection of ribonuclear inclusions in DM2 muscles and their absence in DM1, in agreement with the clinical diagnosis and with leukocyte (CCTG)n expansion, suggests that fluorescence in situ hybridization using (CAGG)5 probes, may be a specific method to distinguish between DM1 and DM2. Moreover, the procedure is simple, and readily applicable in any pathology laboratory.

Adult↗
PubMedDate not supplied

[Expression of a defect in the respiratory chain in cultured human cells].

Large scale deletions of mitochondrial DNA (mtDNA) or altered inter-genomic regulation in skeletal muscle have been demonstrated in patients with mitochondrial encephalomyopathies due to Cytochrome C oxidase (COx) deficiency. We have analyzed by Southern blotting and Polymerase Chain Reaction (PCR) the mtDNA in primary muscle cultures (myoblast-myotube stages and at clonal densities) and in fibrogenic subclones obtained from 9 patients with partial COx deficiency who had in their muscle biopsy a subpopulation of mtDNA showing deletions of variable size (between 2.1 and 6.5 Kb). Only in the cultures from one patient, southern analysis revealed in myoblasts and myotubes a mtDNA almost identical to that found in the original muscle biopsy and persistence of deletion in muscle cells grown at clonal densities. The deletion was detectable in fibrogenic lineage only by PCR amplification. The deleted mtDNA molecules were detectable in myogenic or fibrogenic cultures from other patients only by PCR amplification. The different amounts of deleted mtDNA in the various tissues could be due either to an unequal distribution of the altered mtDNA during embryogenesis with amplification of deleted molecules in myogenic lineage or could result from negative selection against the altered mtDNA in rapidly proliferating cells, such as fibroblasts.

Blotting, Southern↗
PubMedDate not supplied

Muscleblind-like protein 1 nuclear sequestration is a molecular pathology marker of DM1 and DM2.

Myotonic dystrophies (DM) are repeat expansion diseases in which expanded CTG (DM1) and CCTG (DM2) repeats cause the disease. Mutant transcripts containing CUG/CCUG repeats are retained in muscle nuclei producing ribonuclear inclusions, which can bind specific RNA-binding proteins, leading to a reduction in their activity. The sequestration of muscleblind-like proteins (MBNLs), a family of alternative splicing factors, appears to be involved in splicing defects characteristic of DM pathologies. To determine whether MBNL1 nuclear sequestration is a feature of DM pathologies, we have examined the in vivo distribution of MBNL1 in muscle sections from genetically confirmed DM1 (n=7) and DM2 (n=9) patients, patients with other myotonic disorders (n=11) and from patients with disorders caused by repeat expansions, but not DM1/DM2 (n=3). The results of our immunofluorescence study indicate that, among patients examined, MBNL1 nuclear sequestration in protein foci is a molecular pathology marker of DM1 and DM2 patients where ribonuclear inclusions of transcripts with expanded CUG/CCUG repeats are also present. These findings indicate that MBNLs might be important targets for therapeutic interventions to correct some of the specific features of DM pathology.

Cell Nucleus↗
PubMedDate not supplied

[The average thickness of trabecular osteons in the iliac crest in normal subjects].

The mean wall thickness (MWT), measured by the Kragstrup technique, and the trabecular bone volume (TBV), have been measured in 50 transiliac undecalcified bone biopsies performed in 50 subjects who died suddenly (traffic accident, carbon monoxide, poisoning). Diseases affecting the skeleton were excluded in the autopsies. Our values for MWT were similar to those found in previously published studies except those of Kragstrup's group, in which values are higher. As our measuring technique was that of Kragstrup, these results could be explained either by a difference in staining methods (Solocromo cyanine R and Goldner method respectively) or by the differences in populations considered (French and Danish respectively). Our study confirmed a significant decrease in MWT and TBV with age and a positive correlation between MWT, TBV and age.

Adolescent↗
PubMedDate not supplied

Neural regulation of acid maltase in an unusual adult onset deficiency.

In a 48-year-old female, the first symptoms apparently manifested themselves 18 years before, with occasional tripping and weakness in both legs. During the next 18 years, weakness progressed and the patient developed a waddling gait; she became unable to rise from a lying or seated position unassisted and the shoulder girdle also became affected. Neurological examination revealed limb and shoulder girdle predominantly involving the lower extremities. We established cell cultures from muscle biopsy specimens obtained from our patient and carried out morphological analysis which, although aspecific, demonstrated clear signs of neurogenic suffering. This was confirmed in EMG studies performed. Biochemical analysis revealed very low acid maltase residual activity. We describe an unusual case of adult-onset acid maltase deficiency (AMD) with neurogenic atrophy and low residual activity. Innervated myofibres prepared by co-culturing the patient's myoblasts, with spinal cord foetal mouse explants were not associated with an abnormal in vitro maturation of the innervated myofibres as expected by the very low residual enzymatic activity found both in the muscle biopsy specimens and in the muscle cultures. There is strong suggestion that factors other than the amount of residual activity must be involved to determine the clinical manifestation of this disease.

Animals↗
PubMedDate not supplied

Muscle surface mechanical and electrical activities in myotonic dystrophy.

The dimensional changes of the muscle fibres of the active motor units generate a signal, labelled as mechanomyogram (MMG), related to the number and firing rate of the active fibres. Aim of the study was to evaluate if the root mean square (RMS) of the surface EMG, of the MMG and their relationship (electromechanical coupling efficiency, EMCE) are related to the clinical stage of patients affected by myotonic dystrophy. The EMG and the MMG were recorded during isometric contractions at 20%, 40% and 60% of the maximal voluntary contraction (MVC), in less (elbow flexors, EF) and more (finger flexors, FF) affected muscles in 10 myotonic dystrophy (DM) patients (duration of disease: 15-22 yr.; MDRS scale: 3-4) and in 10 age matched controls (C). It resulted that I) the MVC was only 30% lower in DM than in C (P > 0.05) for the EF but 74% lower (P < 0.001) for the FF; II) at the same relative force the MMG-RMS and the EMG-RMS in DM were significantly lower than in C (P < 0.05); III) the EMCE was almost the same in DM and C for EF but dramatically lower for FF. In conclusion these findings provide evidence that the EMCE changes due to the dystrophic process can be monitored by this new and non invasive technique. A good concurrence of clinical findings and experimental results was observed.

Adult↗