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Biomedical subjects

K Uezono

Publications and source records attributed to K Uezono.

66 records · Page 4Linked to original sources
PubMed1980

Influence of unilateral adrenalectomy on renin-angiotensin-aldosterone system in primary aldosteronism.

In a study of 14 patients (11 Japanese and 3 white North Americans) with aldosterone-producing tumor carried out within 2 to 4 weeks after unilateral adrenalectomy, both plasma renin activity (PRA) and plasma aldosterone concentration (PAC) increased almost normally with short-term sodium depletion and upright posture. Aldosterone excretion rate (AER) also increased significantly with sodium depletion, and was normally suppressed by sodium loading. Highly significant correlations were observed between PRA and PAC (r=0.89, p < 0.001) or AER (r=0.88, p < 0.001) ater operation, whereas there had been no such correlation before operation. Either physiological or laboratory findings were normalized or markedly improved in all cases although pathohistological diagnosis was made as adenomatous hyperplasia in 10 out of 11. These results indicate that within 4 weeks of operation PRA and the remaining adrenal gland can almost normally respond to stimuli such as sodium depletion and upright posture regardless of the amount of spironolactone given preoperatively.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

A school refusal case with biological rhythm disturbance and melatonin therapy.

An 18-year-old male high school student with school refusal and circadian rhythm disturbance is reported. At 17 years of age, he was unable to attend school because of a reversal of the daily rhythm and a moderate depressive feeling. Other circadian rhythms, including deep body temperature (DBT), and plasma melatonin, cortisol and beta-endorphin, also showed quite different or abnormal curves compared with those in normal controls. He was treated with methyl B12 and melatonin, which normalized the circadian rhythm, i.e. it became entrained to a 24-h period, and the DBT and hormonal rhythms became closer to normal patterns. These results suggest that desynchronization of the biorhythms, particularly the circadian rhythm, may be one of the important causes of school refusal in Japan, and melatonin and methyl B12 might be useful for treatment of the condition.

Adolescent↗
PubMedDate not supplied

Age-related changes in blood pressure twenty-four-hour pattern in normotensive subjects of two populations.

OBJECTIVES: This study investigates the systolic (S) and diastolic (D) blood pressure (BP) 24-h pattern in normotensive healthy subjects belonging to two populations characterized respectively by a "non-salt culture" (Italian subjects) and a "salt culture" (Japanese subjects) in their dietary salt intake (4-6 g/day in Italians vs 10-12 g/day in Japanese). The comparison was performed by taking into consideration the within-day variability (WDV) and circadian rhythmicity (CR) of BP with respect to age. MATERIALS AND METHODS: Subjects investigated were 862 normotensive healthy subjects (308 Italians and 554 Japanese), stratified by age from 16 to 75 years, who volunteered for a noninvasive BP monitoring in an ordinary day of their life. The SBP and DBP time series were analyzed via conventional parametric statistics as well as chronobiological procedures. RESULTS: The biometric estimates demonstrate that BP changes in its WDV and CR as a function of age in both populations. Despite the difference in their habitual salt intake, the age-related changes in BP WDV and CR result to be almost comparable at the cross-sectional contrasts, giving origin to age-related trends for SBP and DBP which are significantly parallel. CONCLUSIONS: The comparability of BP WDV and CR in the two populations with a substantial difference in salt intake suggests that the normotensive status in human races is realized despite the difference in their habitual salt intake. This implies the ancestral development of mechanism(s) of adaptation to the possible "sodium luxus consumption". Although the adaptive mechanisms which provide a normotensive regimen under different conditions of sodium intake are almost unexplored, the racial adaptation to dietary salt constitutes, however, the initial condition for the cause-effect nexus between dietary salt intake and hypertension in human populations.

Adolescent↗
PubMedDate not supplied

Human mesor-hypertensive chronorisk.

Twelve endocrine variables in blood from a small number of clinically healthy adult women were sampled systematically around the clock and the seasons. Pattern discrimination methods singled out certain hormone values in certain seasons as classifiers for a high vs low risk of developing diseases associated with a high blood pressure. Further evidence in support of such classifiers is obtained on data from adolescent, menstrually cycling young adults and post-menopausal women, here analyzed as pool of series, with the scope of the data from any one age group greatly extended by a resampling procedure, namely, by bootstrapping. This mathematical approach was carried out on data series around the clock and seasons on several hormones as well as systolic and diastolic blood pressure. Classifier roles were strongly supported for plasma aldosterone and thyroid stimulating hormone, originally by an analysis of variance and, in the case of aldosterone, by circannual cosinor analysis and by numerical resampling. Circannual bootstrapping, a procedure recommended for broad routine use as a safeguard for hypothesis testing, was also done for plasma cortisol, dehydro-epi-androsterone sulfate and prolactin, variables for which (parametric) analyses of variance and cosinors did not reveal any difference between groups at high and low cardiovascular risk. In these instances, bootstrapping results are tentative and await further analyses. Results show the ability of circannual bootstrapping to detect outliers. Identification of classifiers provides cost-effective endocrine checks complementing the targeted automatic monitoring of blood pressure. Circannual indices for risk evaluation are, however, costly in several ways since it takes at least a year and quite a few samples to estimate them reliably. Accordingly, we also extended the scope of previous results by the application of an added procedure for circadian bootstrapping. With circadian as well as circannual bootstrapping, we here illustrate a major potential component of a system of chrono-engineering for health maintenance. This system should start with focus on the newborn. The results on adults here analyzed are likely to be more prominent in the neonate, to the extent that they are genetic in origin, yet amenable to modification by the extra-uterine environment.

Adolescent↗
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

The human blood pressure chronome: a biological gauge of aging.

OBJECTIVE: This study examines changes in the broad time structure (chronome) of blood pressure (BP) as a function of age. DESIGN: This is an observational study. SETTING: The study was conducted at the Chronobiology Laboratories of the University oi Minnesota, Minneapolis, Minnesota. PARTICIPANTS: Seventy-two individuals 12 to 106 years of age provided a 7-day record of BP measured indirectly with an ambulatory monitor, mostly at 15-60-minute intervals. MAIN OUTCOME MEASURES: Amplitudes in least squares spectra at frequencies of 1 to 7 cycles per week and 1 to 8 cycles per day were analyzed by linear regression as a function of age. A two-way analysis of variance for subjects classified in four age groups tested for any variance transposition from the circadian (about-daily) to the infradian (frequency lower than one cycle per day) and/or to the ultradian (frequency higher than one cycle per day) domain. RESULTS: The decreasing circadian BP amplitude with age is accompanied by an increase in infradian and ultradian prominence. The day-to-day variability in circadian characteristics also increases with age. CONCLUSION: A variance transposition from the circadian to the neighboring ultradian and infradian domains characterizes the elderly human BP chronome, as a new, technically implementable biological, rather than chronological, gauge of human aging.

Adolescent↗