[The influence of wearing a diaper on static and dynamic postural control in the elderly].

AIM: To clarify characteristics of static and dynamic postural control in elderly people, postural sway during static standing, during an activity, and static standing after the activity were compared between young and elderly subjects. In this study, the action of raising pants-type diapers was selected as the model activity for the measurement of dynamic postural control ability. METHODS: To make differences in the ease of putting on the diapers, their contraction strength around the abdomen was adjusted at 5 levels from loose to tight. Postural sway was measured first during static standing with open and closed eyes and, then, during activity and static standing after activity. The subjects' perceived difficulty in putting on the diapers was also evaluated. RESULTS: Postural sway tended to be larger in elderly than younger subjects during static standing, but the differences were not significant. Also, postural sway was markedly increased in elderly subjects during the raising of diapers requiring greater effort. In static standing after an action, postural sway also remained increased after putting on diapers requiring greater effort only in the elderly group. CONCLUSIONS: Postural sway increased, indicating a decline in the dynamic postural control ability, during an action in association with its level of difficulty even in elderly people showing no decline in static postural control ability. In addition, dynamic postural control responses appeared to affect subsequent static postural control responses, inducing a decline in ability.

Pentavalent vanadium at concentration of the underground water level enhances the sweet taste sense to glucose in college students.

Underground water in volcanic areas contains vanadium when the basalt layer exists among igneous rocks. The concentration of vanadium in drinking water sometimes exceeds 0.8 microM in these areas, however, the physiological effects of vanadium, especially non-toxic effects, at concentrations lower than 1 microM are unknown. In the present experiments, we examined the effect of pentavalent vanadium and tetravalent vanadium at 0.8 and 8.0 microM concentrations on the recognition threshold to taste substances in healthy college students. Pentavalent vanadium, ammonium vanadate, lowered the sweet taste threshold to glucose at 0.8 and 8.0 microM as well. Tetravalent vanadium, vanadium sulfate, did not alter the threshold to glucose either at 8.0 microM or at 0.8 microM. Ammonium vanadate also decreased the sweet taste threshold to L-proline at 8.0 microM. Ammonium vanadate did not influence the sour taste threshold to hydrogen chloride. Neither ammonium sulfate nor ammonium bicarbonate altered the sweet taste threshold to glucose. Therefore, the effect of ammonium vanadate on the sweet taste threshold is attained by vanadium but not by ammonium. It was concluded that pentavalent vanadium at 0.8 microM intensifies the sweet taste sense to glucose rather specifically. We have first shown the physiological effect of vanadium at the concentration of the underground water level.

The effect of anxiety on postural control in humans depends on visual information processing.

To examine the possibility that anxiety affects the control of postural balance, state anxiety, and body sway during orthostatic standing were measured twice in college students with an interval of 1 month. Correlations between the changes in state anxiety and the parameters of body sway were examined by Pearson's correlation analysis. The changes in the enveloped area of body sway and in the maximum length of the antero-posterior body sway showed a positive correlation with the changes in state anxiety (r = 0.543 and 0.659, respectively). The data showed that an increase in anxiety caused instability in the control of postural balance. These correlations were abolished when the eyes were closed. In conclusion, anxiety affects the processing of visual input and influences the net performance of postural control.

REM sleep deprivation suppresses acquisition of classical eyeblink conditioning.

STUDY OBJECTIVES: The aim of this study was to investigate the issue of whether REM sleep is involved in implicit learning through the cerebellum-related neural circuit via the use of classical eyeblink conditioning (CEC). DESIGN: Subjects were divided into three groups: control (sleep without interruption), REM sleep deprivation (RD), and slow wave sleep (stage 3+4) deprivation (SD). The CEC was performed after 8 hours of ordinary nocturnal sleep or sleep disrupted at a selected sleep stage. SETTING: A university-based sleep laboratory. PATIENTS OR PARTICIPANTS: Twenty-seven healthy volunteers (all men, aged 23.2+/-0.6 years). INTERVENTIONS: The CEC was measured after selective sleep deprivation or ordinary nocturnal sleep. MEASUREMENTS AND RESULTS: The eyeblink reflex was conditioned using a classical delay conditioning paradigm. The conditioned response (CR) was determined by electromyography measurements of the orbicularis oculi muscles. The rate of appearance of the CR was compared among the three groups. Compared with the control subjects, RD subjects were significantly deficient in their capacity to acquire conditioned eyeblinks, while no difference was found among the SD subjects. CONCLUSIONS: This study suggests that RD suppresses the cerebellar function in CEC and that REM sleep is closely linked with the learning function in the cerebellum.

Age-related changes in control of blood pressure and heart rate during sleep in the rat.

STUDY OBJECTIVES: The aim of this study was to determine age-related changes in the control of mean arterial pressure (MAP) and heart rate (HR) during sleep, and its relationship to the baroreflex in aging. DESIGN: MAP, HR, body temperature (TP), spontaneous activity (ACT), and sleeping/waking duration were monitored for 24 hours in groups of young (10-12 wk old) and old (23-24 mo old) rats. SETTING: The sleep laboratory at the University of Tokushima. PARTICIPANTS: Subjects were 8 young (10-12 wk old) and 7 old (23-24 mo old) Wistar rats. INTERVENTIONS: Reflex control of HR was evaluated by examining various pressure responses to an intravenous bolus injection of phenylephrine and sodium nitroprusside. MEASUREMENTS AND RESULTS: MAP and TP were recorded by a radiotelemetry system. HR was detected from the AP signal. ACT was counted by a photo-sensor system. In the case of old rats, the sensitivity of baroreflex control of HR was significantly depressed, and the spontaneous increase of MAP and HR during REM sleep and the MAP drop at the end of REM sleep were significantly enhanced. The old rats showed no large deterioration of the circadian profiles of MAP, HR, TP, and the amount of sleep. CONCLUSIONS: The baroreflex dysfunction is considered to appear in an early stage of the aging process, and to affect the control of MAP and HR during sleep.

[Intraoperative management for a patient with heparin-induced thrombocytopenia (HIT) undergoing off-pump coronary bypass surgery using argatroban, a direct thrombin inhibitor].

HIT type II is one of the severe complications of heparin therapy. The antibody for the heparin-PF 4 complex, which causes thrombocytopenia of less than 100 x 10(3).microliter-1, thrombosis and DIC-like symptoms, is produced. We managed the patient with HIT type II, who underwent off-pump CABG using argatroban, a direct thrombin inhibitor, as an anticoagulant. Intraoperative activated coagulation time (ACT) was maintained above 250 sec with 5.0 micrograms.kg-1.min-1 of argatroban infusion and all the procedures were successful. We also investigated the platelet count in the 100 patients with heparin therapy in CCU. The incidence of the platelet depression after heparin administration was as high as 59%, and in 12% of the patients the platelet count dropped below 100 x 10(3).microliter-1. In conclusion, thrombocytopenia by heparin therapy is not rare, and argatroban as an anticoagulant during off-pump CABG is thought to be useful.