Theoretical analysis of surface EMG in voluntary isometric contraction

Summary A new stochastic model of the surface EMG is suggested and the spectral density of the surface EMG is studied theoretically and experimentally to confirm the validity of this model.Theoretical results show that while the contraction level is not so high, the shape of the spectral density (distribution) does not change and its amplitude is directly proportional to the motor unit firing frequency and recruitment.To illustrate the theoretical results, experiments were carried out for rectus femoris and biceps brachii. The surface EMG was lead off by bipolar surface electrodes. And the spectral density of the surface EMG was calculated using FFT algorithm.From these experimental results, it was confirmed that our theoretical results were almost valid.     

Clinical Application of Serum Pepsinogen I and II Levels for Mass Screening to Detect Gastric Cancer

A considerable number of gastric cancers derive from stomach mucosa where chronic atrophic gastritis is severe and extensive. Based on the fact that the serum pepsinogen levels provide a precise measure of the extent of chronic atrophic gastritis, we have devised a mass screening method involving serum pepsinogen measurement to identify subjects at high risk of gastric cancer. In 1991, we screened 4,647 workers (male: 4,113, female: 534, mean age: 49.0 years) at a Japanese company using this method. Out of 875 subjects (18.8%) with a serum pepsinogen I level of less than 50 μg/liter and a pepsinogen I/II ratio of less than 3.0, 676 subjects (14.5%) were selected for further investigation by endoscopy. This led to the detection of four subjects (0.086%) with gastric cancer (three in an early stage) and four subjects with adenoma. The cancer detection rate of this new screening method was comparable, and in some respects superior, to that of the traditional barium X-ray screening. Since the incidence of test-positive subjects was as low as 10% amongst subjects aged less than 40, this screening method appears to be especially useful for screening of younger generations. The new method is less expensive than the traditional barium X-ray and subjects experience little discomfort. Further, many serum samples can be quickly measured simultaneously. The results of this study have indicated that serum pepsinogen screening provides a valuable method for detecting gastric cancers.     

Questionnaire survey on periodic ocular examination in Japanese diabetic patients

PURPOSE: To identify the reasons why diabetic patients do not undergo periodic examination. DESIGN: Cohort study. METHODS: A questionnaire survey of 1,333 Japanese type 2 diabetic patients was conducted at Tokyo Women's Medical University. Performance of ocular examinations was investigated over 5 years and the reasons for not undergoing examination were analyzed. RESULTS: Periodic ocular examination was performed in 69.5% of patients, but not in 30.5%. The questionnaire survey showed that physicians usually explained the risk of ocular complications and recommended periodic examination. More than 98% of the patients were aware of diabetic eye disease. Multivariate logistic regression analysis showed the main reason for skipping examination as a reason was that patients believed they had no diabetic retinopathy. CONCLUSIONS: Patients should be informed about the necessity of receiving periodic ocular examination even if they do not yet have retinopathy.     

Peptic ulcer in the elderly--general considerations,definition and classification

People over age 60 constitute a substantial and growing proportion of the population in Japan. So it is important that caregivers need to keep in mind the approach to acid related disease in the elderly. We review the physiologic changes of the gastrointestinal tract and related organs with age, epidemiology, unique clinical features, and special considerations in management of digestive disorders in the elderly. Identifying physiologic changes that can be attributed to aging has proven to be quite difficult. Because normal changes of aging have produced conflicting results of changes due to diseases often found in elderly. In the elderly, the manifestation of peptic ulcer is more likely to be silent. The risk of complications, particularly when consuming NSAIDs, is increased in the elderly. Elderly individuals also poorly tolerate ulcer complications, in large part secondary to a higher risk of associated illness.     

Peripheral pulmonary artery aneurysms in patients with pulmonary artery hypertension

Pulmonary artery aneurysm (PAA), especially the peripheral type, is a rare disease. We report 2 cases of peripheral PAA with pulmonary artery hypertension. Complication associated with peripheral PAA was hemoptysis. Endovascular coil embolization was performed successfully in one patient. The other with peripheral PAA was died of massive hemoptysis. In patients with peripheral PAA, coil embolization is one therapeutic option. We summarized cases with peripheral PAA in Japan.     

A surface electrode array for detecting action potential trains of single motor units

Action potentials of single motor units were detected by a linear surface electrode array placed perpendicular to the longitudinal axis of the biceps brachii. Twelve myoelectric signals were derived simultaneously from a voluntarily contracting muscle. Using a visual feedback control, 3 subjects produced spike trains of single motor unit action potentials (MUAPs) at a weak contraction. When the myoelectric signals showed an interference pattern at a moderate contraction, several MUAPs were isolated by a visual analysis. MUAPs occurring at about fixed intervals with constant amplitudes and with identical wave forms were presumed to be the action potential trains of single motor units. Reliable estimates of single MUAP wave forms were obtained by averaging and superimposing the detected signals at a timing of characteristic potential peaks. Then not only the firing rate of the spikes but also the territory and the wave form of single MUAPs were investigated. Most MUAPs had a sharp and symmetrical distribution of potentials on a skin surface along the muscle circumference, while some MUAPs showed complex wave forms with some separate potential peaks. The possible arrangement of muscle fibers belonging to the motor units was estimated from the MUAP wave forms.     

No evidence for significant association between GABA receptor genes in chromosome 15q11–q13 and autism in a Japanese population

The γ-aminobutyric acid (GABA) receptor genes GABRB3, GABRA5, and GABRG3 located on chromosome 15q11–q13 have been major candidates for susceptibility genes for autism, a neurodevelopmental disorder with a complex genetic etiology. In this study, we first investigated the association between the GABA receptor genes and autism in a Japanese population by analyzing 11 single nucleotide polymorphisms (SNPs). Intron 3 of GABRB3 was densely mapped because the previous studies observed the association of the microsatellite 155CA-2 located in the region. We observed no significant difference in allelic frequencies or genotypic distributions of the 11 SNPs between patients and controls. A permutation test showed no significant global differences in estimated haplotype frequencies between patients and controls. Analysis after confining the subjects to males showed similar results. Thus, this study provides no positive evidence of an association between the GABA receptor genes and autism in a Japanese population. However, in a SNP (rs3212337) located near the microsatellite 155CA-2, a significant deviation from the Hardy–Weinberg equilibrium was observed in patients (p = 0.029, corrected for multiple testing). This finding may suggest further studies around the markers for more definitive conclusions.     

Application of the interseptal alveolotomy for closing the oroantral fistula

This article describes a new application of the interseptal alveoplasty to close oroantral fistulae caused by dental extraction. The surgical technique is described, and its advantages are compared with those of other techniques. The technique was used to treat eight patients with comparatively small fistulae in the soft tissue, approximately 1 to 5 mm wide. All fistulae were successfully closed. It is proposed that the technique provides greater flexibility in the treatment of fistulae. In addition, because there is a bony base, this promotes more successful healing than other commonly used procedures.