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Biomedical subjects

J Kamiya

Publications and source records attributed to J Kamiya.

At least 145 records · Page 8Linked to original sources
PubMed1983

Morphogenesis of human colonic cancer.

A total of 155 early carcinomas, collected from colonoscopic polypectomy cases, surgically removed specimens, and resected colon from patients with adenomatosis coli, were histologically investigated in order to find their characteristic morphologic features. The commonest types of early carcinomas examined had a short stalk or were broad-based, and carcinomas 1 to 2 cm in diameter were the largest in actual number, although the malignancy rate increased with increasing size. The malignancy rate of small adenomas, under 1 cm in diameter, is higher than previously estimated. The clinical importance of the shape and size of such polyps is stressed for earlier detection of carcinomas of the colon, and an improved concept of the morphogenesis of colonic carcinoma is proposed.

Carcinoma↗
PubMed1982

Biofeedback of alveolar carbon dioxide tension and levels of arousal.

This is a preliminary study designed to investigate the potential usefulness of alveolar (lung) CO2 feedback training in promoting sleep onset in primary insomniacs. The present study was undertaken to determine if normal subjects could, without obvious manipulation of breathing, bring alveolar (lung) CO2 tension under voluntary control using biofeedback techniques and, if so, whether this control would be accompanied by shifts in level of wakefulness. Subjects participated in five baseline and five training sessions in which EEG, alveolar CO2 tension, and thoracic/abdominal respiratory movement were monitored. The feedback consisted of a pitch-modulated tone plus visual scores. We found that CO2 tension in awake portions of "up" trials was significantly higher than for awake portions of "down" trials (p less than .01), indicating that learning had occurred. In the initial trials, when subjects raised CO2 tension they became drowsy and often fell asleep, and when they lowered CO2 tension they aroused themselves. However, when subjects were awakened immediately upon falling asleep, there developed a decoupling of EEG and CO2 changes. The presence of such a decoupling phenomenon makes it unclear whether CO2 feedback will be useful in promoting sleep onset in primary insomniacs.

Adult↗
PubMed1982

Discrimination of sleep onset stages: behavioral responses and verbal reports.

In a descriptive experiment on discrimination five human subjects were studied during the transitional period of sleep onset. Subjects were aroused by an abrupt auditory stimulus, attempted to discriminate the pre-arousal stage by a behavioral response, and answered a series of standardized questions. These questions focused on specific characteristics of private experience associated with sleep onset. Of 180 awakenings, subjects correctly identified 109 sleep-onset stages. Subjects' answers were analyzed to determine what criteria were used to make the discrimination among sleep-onset stages and to examine their self-awareness of changes in private experience. It was established that there are stage-related changes in mental processes and content and that these may aid subjects in making such discriminations. Implications of the methodological approach used in this study are discussed.

Adult↗
PubMed1981

The nature of respiratory changes associated with sleep onset.

This study provides a systematic examination of factors that may contribute to respiratory changes associated with sleep onset. The electroencephalogram, alveolar CO2 tension, patterns of abdominal and thoracic respiratory movements, and respiratory rate were measured in three sessions each on 12 normal subjects as they fell asleep, and also on 5 of them as they lay awake. Nonintrusive respiration measurement devices were used. Resting awake CO2 tension was found to increase significantly across sessions. In addition, CO2 tension was significantly higher during stages 1 and 2 of sleep than during wakefulness on days 2 and 3. There was also a shift from relatively greater abdominal expansion toward relatively greater thoracic expansion with sleep onset. None of these changes occurred when subjects remained awake during a session. We conclude that changes in respiration with sleep onset cannot be accounted for solely by changes due to habituation, merely lying quietly, or the effects of the measuring devices. Rather, they appear to be caused by a central interaction between centers controlling the level of wakefulness and those controlling respiration.

Abdomen↗
PubMed1981

Discrimination of early sleep stages: behavioral indicators.

Six subjects participated in a one-night sleep-onset experiment. They were aroused from stage 1 and stage 2 as defined by standard electroencephalographic criteria. Subjects pressed a button upon arousal to indicate which of two subjective states they were in just before awakening. Performance accuracy from stage 1 awakenings appeared to remain relatively constant at approximately 83%; performance from stage 2 awakenings showed increasing accuracy. Response latencies increased between stage 1 and stage 2 awakenings.

Adult↗
PubMed1980

Colonoscopic polypectomy in diagnosis and treatment of early carcinoma of the large intestine.

Histologic investigation and analysis of 370 polyps, removed via colonoscope, demonstrated a malignancy rate of adenomas of about 20 per cent. Even small adenomas under 1 cm in diameter were found to have a higher malignant potential than previously appreciated. The malignancy rate was higher with increasing size, and adenomas in females had a much higher malignant potential than in males. It is obvious that colonoscopic polypectomy is valuable in detecting and treating early carcinomas of the colon.

Adenoma↗
PubMed1980

Cardiotoxic effects of 5-fluorouracil in the guinea pig.

In order to search into the underlying mechanisms of ECG changes suggestive of ischemia observed in humans and in rabbits after administration of 5-fluorouracil (5-FU), experiments were performed in anesthetized open-chest guinea pigs. The substance produced similar ECG changes in this species as well, after a rather long latent period of around 3 hours after intravenous administration. The incidence of ECG abnormality in animals given 60 mg/kg was 7/7, while that in animals given 30 mg/kg was 4/9. with 10-20 mg/kg, ECG changes were not observed during an experimental period as long as 5 hours. Associated with these ECG changes, a depletion of the high-energy phosphate compounds of the ventricular myocardium was observed. Analysis of tricarboxylic acid cycle (TCA cycle) intermediates revealed an accumulation of citrate within the myocardium, suggesting a malfunction of TCA cycle resulting from an inhibition of aconitase by fluorocitrate, as a cause of depletion of the high-energy phosphates. It is highly probable that the accumulation of citrate was due to the formation of fluoroacetate, an inhibitor of aconitase, from 5-FU via alpha-fluoro-beta-alanine, a major degradation product of 5-FU, for it is known that beta-alanine is usually converted to acetate.

Adenosine Diphosphate↗
PubMed1978

Anxiety change through electroencephalographic alpha feedback seen only in high anxiety subjects.

Subjects who were either high or low in trait anxiety used alpha feedback to increase and to decrease their electroencephalographic alpha activity. The alpha changes were tightly linked to anxiety changes, but only in high anxiety subjects (for whom anxiety was reduced in proportion to alpha increases, and was increased in proportion to alpha suppression). Low trait-anxiety subjects were superior at both enhancement and suppression training, but their alpha changes were not related to anxiety changes. In both groups, anxiety changes were generally unrelated to either resting levels or changes in frontalis electromyograms and respiration rate. These results suggest that long-term alpha feedback training (at least 5 hours) may be useful in anxiety therapy.

Alpha Rhythm↗
PubMed1978

Methodological issues in alpha biofeedback training.

Current controversies concerning outcomes of EEG alpha feedback training are at least in part due to methodological differences among different studies. The aim of this paper is to provide future and present researchers in this field with an analysis of methods used in most of the studies published from 1968 to 1976, and to comment on those methodological issues we think most important. These include alpha assessment, training schedules, and uni- versus bidirectional training. This analysis is accomplished in part by a series of tables listing 45 studies and the detailed methodologies used. It is believed that the probabilities of successful feedback enhancement of alpha can be substantially improved by incorporating the following suggestions: (a) employing at least four training sessions, (b) the use of continuous rather than dichotomous feedback, supplemented by periodic quantitative scores of progress, and (c) using training trials of at least 10 minutes' duration.

Alpha Rhythm↗