Isokinetic knee joint test in "gonalgia sine materia"

Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature.     

Refined genetic mapping of autosomal recessive chronic distal spinal muscular atrophy to chromosome 11q13.3 and evidence of linkage disequilibrium in European families

Chronic distal spinal muscular atrophy (Chronic DSMA, MIM (*)607088) is a rare autosomal recessive disorder characterized by a progressive motor weakness and muscular atrophy, predominating in the distal parts of the limbs. A form of Chronic DSMA gene has been previously mapped to chromosome 11q13 in the 10.3 cM interval defined by loci D11S1889 and D11S1321. By linkage analysis in 12 European Chronic DSMA families, we showed that a disease gene maps to chromosome 11q13.3 (Z(max)=6.66 at theta=0.00 at the DSM4 locus) and suggested that this condition is genetically homogeneous. Recombination events allowed us to reduce the genetic interval to a 2.6 cM region, telomeric to the IGHMBP2 gene, excluding this gene as the disease causing gene in Chronic DSMA. Moreover, partial linkage disequilibrium was found between three rare alleles at loci D11S1369, DSM4 and D11S4184 and the mutant chromosome in European patients. Analysis of the markers at these loci strongly suggests that most Chronic DSMA chromosomes are derived from a single ancestor. Refinement of the Chronic DSMA locus will hopefully allow to test candidate genes and lead to identification of the disease-causing mutations.     

Comparative in vitro study on a ultra-high roughness and dense titanium coating

A new implant surface has been developed with the purpose of avoiding as much stress shielding as possible, and thus prolong the prosthesis lifespan. The aim of this study was to investigate the in vitro effect of this new ultra-high roughness and dense Titanium (Ti) surface (PG60, Ra = 74 microm) in comparison with medium (TI01, Ra = 18 microm) and high (TI60, Ra = 40 microm) roughness and open porous coatings; all the coatings were obtained by vacuum plasma spraying. MG63 osteoblast-like cells were seeded on the tested materials and polystyrene, as control, for 3 and 7 days. Cells proliferated on the material surfaces similarly to the control. Alkaline phosphatase activity had lower values for TI60 than TI01 (p < 0.0005) and PG60 (p < 0.005). Osteocalcin levels measured on TI60 were significantly (p < 0.0005) lower in comparison with TI01 and PG60 at 7 days. Procollagen-I synthesis reduced with increasing roughness and the lowest data was found for PG60. While at 3 days Transforming Growth Factor beta1 levels augmented with increasing roughness, at 7 days TI60, the high roughness surface, was significantly lower than PG60 (p < 0.005) and TI01 (p < 0.001). All tested materials showed significantly higher Interleukin-6 levels than those of polystyrene at both experimental times. Nitric Oxide activity on TI01 was significantly (p < 0.05) higher than on TI60 and polystyrene. In conclusion, the new ultra-high roughness and dense coating PG60 provided a good biological response, even though, at least in vitro, it behaved similarly to the coatings already used in orthopaedics.     

The organization of thalamic connections

Connections ascending to the thalamus. Contrary to classical opinion, all thalamic nuclei receive extrathalamic afferents. Segregation or convergence within a topographically defined nucleus represent two modalities of thalamic afferents. In addition, certain topographically organized thalamic afferents possess "privileged" or primary "targets" in the thalamic nucleus while others possess supplementary "targets" in other thalamic nuclei (see cerebellar, pallidal and spinothalamic projections). Ascending connections from several brain stem structures can converge on the same nucleus or diverge to several thalamic nuclei. Thalamic connections with the telencephalon. Methods for determining axonal transport have demonstrated that all thalamic nuclei, with the exception of the reticular nucleus and the ventral part of the lateral geniculate body, project towards the cerebral cortex. Four nuclear complexes can be recognized in the cat as a function of the different modalities of localization, concentration and lamination of the projections towards the cortex and the central grey nuclei. In general, the thalamocortical connections have reciprocal ipsilateral corticothalamic projections originating in the infragranular layers of the cerebral cortex. The reticular nucleus and the ventral part of the lateral geniculate body, which is not projected to the cerebral cortex, are exceptions. Each cortical area receives a "privileged" connection from a thalamic nucleus and a supplementary connection- from one or several other thalamic nuclei. The "privileged" connections usually pass to the fourth and third layers of the neocortex, and sometimes also to the first layer. In contrast, the supplementary connections pass to different superficial or deep cortical layers. Each nucleus is formed of subunits which possess different hodologic and topographic characteristics as a function of the nucleus considered. Convergence or divergence of thalamocortical and corticothalamic projections on the different thalamic nuclei, as well as the laminar distribution of efferents in the cerebral cortex, are related strictly to the hodologic organization of different cellular subunits constituting the nuclei. Concentration or diffusion of thalamic projections on cerebral cortex is related more to the single or multiple projection of cell populations belonging to a thalamic nucleus than to widespread collateralization of thalamocortical axons.     

Clinical neurophysiology

Poster Session 1

Clinical neurophysiology     

Impaired apoptosis in mitogen-stimulated lymphocytes of patients with multiple sclerosis

We investigated the sensitivity to cell death of peripheral blood mononuclear cells (PBMCs) from patients with multiple sclerosis (MS). PBMCs from MS patients, following PHA stimulation, were less sensitive to cell death than those from healthy donors (mean +/- s.e.m., 22.5 +/- 1.9 in MS patients vs 36.5 +/- 2.8 in healthy controls; p = 0.0003). However, when Fas-agonist antibody was added, the increase in respect to apoptosis induced by mitogen alone was even higher in MS patients than in controls. In addition, PHA-activated PBMCs from MS patients showed higher surface expression of Fas than controls, while Bcl-2 expression was decreased. This finding raised the question of whether an impaired generation of apoptotic signals may be contributing to the immune component of MS.     

Time course of narrow frequency bands in the waking EEG during sleep deprivation

Electroencephalograms (EEGs) of 14 normal subjects were recorded every 2 h during 38 h constant routines. Adjacent narrow frequency bands (NFB) with similar temporal trends were grouped into frequency clusters. Clusters I (2.00-7.75 Hz) and III (11.00-14.75 Hz) exhibited similar time courses which may reflect both the duration of time awake and a circadian modulation. Cluster II (8.00-10.75 Hz) was characterized by a time course similar to the circadian modulation of core body temperature. Cluster V (18.00-24.75 Hz) was correlated with subjective sleepiness and may reflect the increasing effort made by subjects to perform the task as sleep deprivation lengthened. Various NFB in the waking EEG may reflect different physiological mechanisms underlying variations in vigilance states.     

Bacterial inhibition produced by substances for dentin pretreatment

Dentin treatment before adhesion of composites is performed both to enhance adhesion and to remove the microbial contents of the smear layer. The purpose of these experiments was to evaluate the germicide potential of several dentin treatments used in adhesive systems and of some cleansing solutions. Different germs involved in caries processes were used (Candida Albicans, Streptococcus mutans and Actinomyces naeslundii) to prepare suspensions. Half a milliliter of each of the suspensions was transferred to test tubes and an equal volume of the following substances was added: Scotch Prep Dentin Primer (P), Gluma Cleanser (G), Cleaner Sol. (C), Tubulicid Blue (TB) and Red Label (TR), Blue Experimental Solution (SB) and Red Experimental Solution (SR) and sterile distilled water (control). The preparation was incubated at 37 degrees C for seven days to test viability. P, TR, TB and SB produced complete inhibition of germs tested. The results reveal that, "in vitro", not all the substances tested exert a germicide effect on the microorganisms analyzed.