Search PubMed⌕ Search

Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

445 records · Page 25Linked to original sources
PubMedDate not supplied

Spin-offs from blood pressure and heart rate studies for health care and space research.

Evidence here cited underlies resolutions at international meetings to initiate a chronobiology project for health improvement. This project demonstrates expeditiously the feasibility and the health benefits of incorporating chronomedical considerations in the diagnosis, treatment, and prevention of one (or a few closely related) vascular (and oncological) diseases, that have high awareness and importance in the public perspective. Thereby, chronomedicine should become a mainstream basic and applied speciality leading to continual improvement in national/international health status. Reference data obtained for health care can also serve to give a better understanding of the relationship between the terrestrial biosphere and cosmoi near and far.

Blood Pressure↗
PubMedDate not supplied

Gender, age and circadian blood pressure variation of apparently healthy rural vs metropolitan Japanese.

Interim chronobiologic cardiovascular reference data have been described; 353 clinically healthy Japanese subjects were monitored every 15 min for 24h on 2 occasions. Special attention was paid to the difference between metropolitan and rural areas. Not only the MESORs of SBP and DBP, but also the circadian amplitudes, were higher in the Tokyo than in a rural area (Komaki, Aichi Prefecture). Age-related alterations in the circadian profile of cardiovascular variables were noted for women but not for men. The average MESOR remained similar for SBP in men, whereas in women the average MESOR increased with advancing age in both urban and rural areas. The average circadian amplitude of SBP also increased with age in women, but not in men. No significant deviations of acrophase with age were found for SBP and DBP in men, whereas in rural women the acrophase tended to occur earlier with increasing age.

Adolescent↗
PubMedDate not supplied

Ambulatory blood pressure monitor and 'analyzer'.

Earlier, we described the format provided by an ambulatory blood pressure monitor, the ABPM-630 with a data handler (AA-200), manufactured by Colin Medical Instruments. A detailed procedure for data transfer from the memory cassette into the analyzer and into an IBM PC in a format compatible with programs in the Chronobiology Laboratories is provided with a brief description of the hardware used. Among several instruments available for ambulatory blood pressure and heart rate monitoring, the ABPM-630 has several advantages: it does not require electrodes (a merit it shares with other instruments); it is portable, even if there are smaller ones; it functions silently, being activated by a CO2 cartridge; and it provides data obtained by two methods, by auscultation and by oscillometry, in part as a backup for one another, depending on whether auditory or movement noise are within limits acceptable to the instrumentation. This feature renders it more likely that some record will be obtained. In our earlier publication, we had referred to and then briefly described a special program which converts the format of the data handler into a format acceptable for analyses with programs from the University of Minnesota Chronobiology Laboratories. Herein, the operation of transferring data from the ABPM-630 memory cassette to an IBM-compatible personal computer (PC) is described, with an indication further of the programs used in the Chronobiology Laboratories.

Ambulatory Care↗
PubMedDate not supplied

Experimental and clinical chronocardiology.

Recent advances of the chronobiologic approach to experimental and clinical cardiology was reviewed. First, the maximum entropy method (MEM) was introduced as one of the statistical methods analyzing the circadian periodicity. The MEM power spectrum showed a remarkable resolution property. It will play an important role in chronocardiology in cooperation with the cosinor method. Secondly, recent investigations of the relationship between sleep states and cardiac arrhythmias were mentioned from the viewpoints of both experimental and clinical chronocardiology. Next, recent remarkable advance on myocardial ischemia was reviewed. A marked circadian rhythm in the frequency of myocardial infarction onset and sudden cardiac death has been observed. Lastly, a reference has been made to the recent development of ambulatory BP monitoring. A chronobiologic approach to the analysis of time-series data in cardiology will lead to many advantages in clinical practice.

Animals↗
PubMedDate not supplied

Circadian rhythm of cardiac bradyarrhythmia episodes in rats.

It was investigated whether incidence of S-A block and A-V block (type I and II) observed in male Wistar rats shows a circadian periodicity. Under the 14/10 light-dark illumination schedule, circadian periodicity was demonstrated in the occurrence of bradyarrhythmias as well as slow wave sleep, paradoxical sleep locomotive activity and heart beats/hour. This circadian variation of bradyarrhythmia shows two major peaks. The highest peak coincides with the time zone immediately after the start of illumination, and the second peak coincides with the acrophase of the circadian variation in paradoxical sleep. The 25-h period of circadian rhythm of bradyarrhythmias was disclosed even under constant illumination. This circadian variation shows the disappearance of the early peak of two peaks observed in the light-dark schedule. These results show the existence of an endogenous circadian rhythm in bradyarrhythmias as well as in sleep-wakefulness and locomotive activity. This knowledge about the circadian rhythm of bradyarrhythmia must be incorporated into the effective treatment of arrhythmias.

Animals↗
PubMedDate not supplied

Broad scope of a newly developed actometer in chronobiology, particularly chronocardiology.

The scope and the details of a newly developed actometer were introduced. We are able to select a desired threshold of gravity(g)-forces between 0.01g and 0.50g and to simultaneously monitor 3 kinds of activity along with an averaged g-force every minute. As a routine study, we monitored at settings of 0.01g, 0.05g and 0.20g and averaged on one channel. Part of the time, physical activity was monitored together with ambulatorily monitored blood pressure (BP) and the ECG, or at least heart rate (HR). Physical activity showed a circasemiseptan and circaseptan periodicity as well as the circadian component, especially in subjects with an irregular sleep-wakefulness life style. On the average, physical activity was greater on a working day than on a holiday. Everyday physical activity reflects in part the ability to exercise, and it is expected that this actometer can contribute or provide an objective individualized quality-of-life index. The effect of physical activity on circadian profiles of BP, HR and HR variability is also examined. We observed that BP started to increase several hours before getting up. This fact likely shows that there is an endogenous circadian rhythm in BP, independently of the sleep-wakefulness cycle. Lastly, we investigated the relationship between physical activity and HR in patients permanently paced; we confirmed that the DDDR pacing mode was more physiological than the VVI or VVIR mode. This newly developed actometer will bring about further progress in chronobiology.

Adult↗
PubMedDate not supplied

Cross-spectral coherence between geomagnetic disturbance and human cardiovascular variables at non-societal frequencies.

A 35-year-old cardiologist monitored himself with an automatic ABPM-630 (Colin Electronics) monitor, mostly at 15-minute intervals around-the-clock for three years with a few interruptions. In this subject with a family history of high blood pressure and stroke, a cross-spectral analysis revealed a statistically significant coherence at 27.7 days between systolic and diastolic blood pressure and heart rate vs. the geomagnetic disturbance index, Kp. A lesser peak in coherence was found for systolic blood pressure with Kp at a trial period of 4.16 days (P = 0.046). These results suggest that changes in geomagnetism may influence the human circulation, at least in the presence of familial cardiovascular disease risk, and they may do so at frequencies that have no precise human-made cyclic worldwide match.

Adult↗
PubMedDate not supplied

Telehygiene system for preventive chronopharmacology in space and remote areas on earth.

A chronobiologic computerized modular health care (telehygiene) system for humans in extraterrestrial space 1) monitors and analyzes physiologic blood pressure, heart rate and other variation, including that in tumor markers; 2) recognizes earliest risk elevation by dynamic changes in the 'usual value' range (trend and rhythm alteration); 3) prompts timely and timed treatment for cardiovascular and emotional disease and malignancy prevention, and 4) serves for health improvement; the information from the system can also help optimize shift-work schedules for peak performance and provides endpoints of interest in basic science. The system exploits the chronome, a genetically anchored, habitat-synchronized structure of multifrequency rhythms and trends which is now documented (by longitudinal data series) to respond to magnetic disturbance in the solar system, with consequences expressed in catastrophic illness that is best prevented. Such a system, rated by peers as being of highest priority, could complement classical tools such as the stethoscope, proposed by the U.S. Johnson Space Center representative for use on the moon.

Aerospace Medicine↗
PubMedDate not supplied

Circadian blood pressure change after carteolol chloride in younger and older hypertensive patients.

To determine whether there is an age-related difference in circadian blood pressure changes after administration of a beta-adrenergic blocker, 24-hour ambulatory blood pressure was measured before and after administration of long-acting carteolol, a beta-blocker with intrinsic sympathomimetic activity, in 9 younger and 13 older hypertensive patients. Ambulatory blood pressure was measured noninvasively using an ambulatory blood pressure monitor every 30 minutes for 24 hours before and 8 weeks after a once-daily administration of 15 mg of carteolol. Systolic and diastolic blood pressure in the office significantly decreased in both groups after 8 weeks of carteolol treatment. The whole-day systolic and diastolic blood pressures also fell significantly after carteolol treatment in both groups. Carteolol reduced systolic and diastolic blood pressures during the day in both groups. However, no reduction was observed in nighttime systolic blood pressure in either group, although nighttime diastolic blood pressure tended to decrease in the younger group (P = 0.051). The pulse rate during the night significantly increased in both groups, although no change was observed during the day in either group. We conclude that the antihypertensive effect of carteolol on the circadian blood pressure pattern in younger and older hypertensive patients is comparable. Carteolol reduced only daytime blood pressure while hardly affecting the nighttime blood pressure in both groups.

Aged↗
PubMedDate not supplied

Clinical effects of exogenous/endogenous TNF therapy on metastatic lesions of 34 colorectal cancer patients.

BACKGROUND: We performed endogenous/exogenous TNF (EET) therapy using, as a primer, recombinant TNF-SAM2 (rTNF-S) as a premier; it has a broader anti-cancer spectrum and is less toxic than conventional TNF, and OK-432 as a trigger in patients with metastasis of colorectal cancer to the lung and/or liver. METHODS: The subjects consisted of 34 patients of whom 8 had lung metastasis, 17 liver metastasis, and 9 lung and liver metastasis. EET therapy was performed without chemotherapy in 11 patients and with anti-cancer drugs such as mitomycin-C (MMC) and 5-FU in the other 23. RESULTS: No patients showed a complete response. Partial response was observed in 10 patients (29.4%), minor response in 8 (23.5%), no change in 14 (41.2%), and progressive disease in 2 (5.8%). The response rate was 29.4%. A greater effect was observed in patients treated with EET in combination with anti-cancer drugs than those treated with EET alone. No serious side effects were observed, although all patients developed a fever above 38 degrees C, chill, and shiver. CONCLUSIONS: EET therapy with rTNF-S combined with anti cancer drugs chemotherapy may be effective, and further studies are needed to select the most suitable anticancer drugs for combination with, and to determine the effective frequency of treatment.

Adult↗