No abstract

No abstract

No abstract

No abstract

No abstract

Spinal and bulbar muscular atrophy (SBMA) is an adult-onset, lower motor neuron disease caused by an aberrant elongation of a CAG repeat in the androgen receptor (AR) gene. The main symptoms are weakness and atrophy of bulbar, facial and limb muscles, but sensory disturbances are frequently found in SBMA patients. Motor symptoms have been attributed to the accumulation of mutant AR in the nucleus of lower motor neurons, which is more profound in patients with a longer CAG repeat. We examined nerve conduction properties including F-waves in a total of 106 patients with genetically confirmed SBMA (mean age at data collection = 53.8 years; range = 31-75 years) and 85 control subjects. Motor conduction velocities (MCV), compound muscle action potentials (CMAP), sensory conduction velocities (SCV) and sensory nerve action potentials (SNAP) were significantly decreased in all nerves examined in the SBMA patients compared with that in the normal controls, indicating that axonal degeneration is the primary process in both motor and sensory nerves. More profound abnormalities were observed in the nerves of the upper limbs than in those of the lower limbs. F-waves in the median nerve were absent in 30 of 106 cases (28.3%), but no cases of absent F-waves were observed in the tibial nerve. From an analysis of the relationship between CMAPs and SNAPs, patients were identified with different electrophysiological phenotypes: motor-dominant, sensory-dominant and non-dominant phenotypes. The CAG repeat size and the age at onset were significantly different among the patients with motor- and sensory-dominant phenotypes, indicating that a longer CAG repeat is more closely linked to the motor-dominant phenotype and a shorter CAG repeat is more closely linked to the sensory-dominant phenotype. Furthermore, when we classified the patients by CAG repeat size, CMAP values showed a tendency to be decreased in patients with a longer CAG repeat (> or =47), while SNAPs were significantly decreased in patients with a shorter CAG repeat (<47). In addition, we found that the frequency of aggregation in the sensory neuron cytoplasm tended to inversely correlate with the CAG repeat size in the autopsy study, supporting the view that the CAG repeat size differentially correlates with motor- and sensory-dominant phenotypes. In conclusion, our results suggest that there are unequivocal electrophysiological phenotypes influenced by CAG repeat size in SBMA.

No abstract

The shelf life of titanium implant products, that is, a possible time-related change of their bioactivity, has rarely been addressed. The objective of this study was to examine the bioactivity of newly processed and aged titanium surfaces and determine whether ultraviolet (UV) light treatment of the titanium surface restores the possible adverse effects of titanium aging. Titanium disks, either acid-etched or sandblasted, were used immediately after processing (fresh surface) or after storing in dark for 4 weeks (aged surface). Some disks were treated with UV light for 48 h after 4 weeks of storage. Albumin adsorbed to the aged surfaces was only 15% of that adsorbed to the fresh surfaces during 2-h incubation, whereas UV-treated aged surfaces adsorbed equivalent amount of albumin to that for the fresh surfaces. During 24-h incubation, the number of human mesenchymal stem cells attached to the aged surfaces was less than half of that for the fresh surfaces, whereas UV treatment of the aged surfaces increased the number three times. Proliferation, alkaline phosphatase activity, and calcium deposition of the cells were substantially lower on the aged surfaces than on the fresh surfaces, while those on the UV-treated aged surfaces were higher than on the fresh surfaces. The strength of bone-implant integration evaluated at week 2 of healing in a rat femur model was reduced to half after 4 weeks of titanium aging, whereas UV treatment of the aged implants increased the strength to the level equivalent to or even higher than the freshly prepared implants. Fresh and UV-treated aged surfaces were superhydrophilic, while the aged surface was hydrophobic. The data suggest that bioactivity of titanium surfaces degrades with time and that UV treatment of the aged surface increases the bioactivity over the level of the freshly prepared surface.