Effect of masseter muscle activity during wakefulness and sleep on tooth wear.

Purpose: To investigate the effect of masseter muscle activity during wakefulness and sleep on tooth wear.

Methods: Sixteen participants with no or mild tooth wear (NMTW group) and sixteen participants with moderate-to-severe tooth wear (MSTW group) were enrolled. The severity of tooth wear was evaluated using the occlusal and incisal indices of the tooth wear index.

Detection of muscle fatigue caused by repeated posterior tongue lift movement from neck surface EMG: a pilot study.

Background: Fatigue is an important factor for muscle strengthening in rehabilitation medicine. Frequency analysis has been regarded as the gold standard for muscle fatigue assessment in surface electromyography (EMG). However, there are no experiments quantifying fatigue with grouped discharge (GD), which is one of the historical phenomena observed in patients having fatigue, by using high sampling rate recording of EMG.

Coordination of surface electromyography activity in the posterior tongue region during mastication of differently textured foods.

Background: Masticatory movement occurs complicatedly and bilaterally. Although the tongue plays an important role in mastication, bilateral tongue function during mastication has not been clarified yet.

Objective: To investigate the effect of food properties on posterior tongue activity and coordination of muscles bilaterally by electromyography (EMG).

Inhibition of insulin amyloid fibril formation by cyclodextrins.

Localized insulin-derived amyloid masses occasionally form at the site of repeated insulin injections in patients with insulin-dependent diabetes and cause subcutaneous insulin resistance. Various kinds of insulin including porcine insulin, human insulin, and insulin analogues reportedly formed amyloid fibrils in vitro and in vivo, but the impact of the amino acid replacement in insulin molecules on amyloidogenicity is largely unknown. In the present study, we demonstrated the difference in amyloid fibril formation kinetics of human insulin and insulin analogues, which suggests an important role of the C-terminal domain of the insulin B chain in nuclear formation of amyloid fibrils.

Amyloid deposits derived from transthyretin in the ligamentum flavum as related to lumbar spinal canal stenosis.

Amyloidosis is a protein conformational disorder with the distinctive feature of extracellular accumulation of amyloid fibrils that come from different proteins. In the ligamentum flavum of the lumbar spine, amyloid deposits were frequently found in elderly patients with lumbar spinal canal stenosis and were at least partially formed by wild-type transthyretin. However, how amyloid deposits in the ligamentum flavum affect lumbar spinal canal stenosis has remained unclear.

Effect of age and sex differences on wild-type transthyretin amyloid formation in familial amyloidotic polyneuropathy: a proteomic approach.

Background: Age and sex differences are closely related to the onset of senile systemic amyloidosis (SSA) caused by wild-type (WT) transthyretin (TTR). However, the effects of these differences on the amyloid formation mechanism in familial amyloid polyneuropathy (FAP) caused by variant TTR, have remained unclear. To elucidate age and sex differences in FAP, we investigated biochemical characteristics of amyloid deposits in different tissue sites of FAP by proteomic analysis.