Periodic structures and diurnal variation in blood pressure and heart rate in relation to microgravity on space station MIR.

Four Russian crew members were studied on space station MIR, and blood pressure (BP) and heart rate (HR) data were continuously collected. BP and HR data were collected on earth 1 day before orbital flight to the space station, then at weeks 8, 16 and 24 during space flight, and again 1 or 2 days after returning to earth. Time serial data for BP and HR were analyzed by spectral analysis with the MemCalc system (Suwa Trust, Sapporo, Japan). Periodic structures of diurnal variation in systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR were compared at 24-hour, 12-hour and 8-hour intervals, these being determined as the main periodic components for the assessment of BP and HR variability. The 24-h mean levels of SBP and HR during space flight were unchanged. Waking SBP was not different from pre-flight values. During sleep, in-flight changes in HR did not differ from pre-flight values. SBP during sleep in orbit increased to over pre-flight values. Waking DBP was reduced during flight. The SBP and HR phases over a 24-hour cycle were shortened with a more pronounced shortening in weeks 8 and 16 compared with pre-flight values, and at week 24 recovered to preflight values. The 12, 8-hour-cycle remained unchanged, and were similar to pre-flight values. At the space station, the astronauts' mission was carried out under strict control of sleeping and waking hours; therefore, their 24-hour schedule is an artificially constructed situation. Main periodicity structures were maintained by strict control of lifestyle during long-term space flight. The conclusions reached were as follows: 1) SBP levels during sleep in a space environment increased compared with those on earth; 2) the periodicity phase of BP and HR shifted toward to 24-hour cycle as a result of long-term space flight, even though these periods shortened after a few months compared with pre-space flight values.

Blood pressure variability during 120-day head-down bed rest in humans.

Influence of physical inactivity and microgravity to periodic structure of blood pressure was studied. Six healthy males were kept under head-down bed rest (HDBR) for 120 days. Blood pressure and heart rate (HR) were recorded by a portable sphygmomanometer and a Holter electrocardiogram, respectively. The results were analyzed by spectrum analysis. Phase, amplitude and acrophase of systolic blood pressure (SBP) by approximately 24, 12 and 8 h were measured before, 60, 120 day and after HDBR. The phase at 24, 12 and 8 h did not show significant changes during HDBR, and acrophase showed a tendency to shift to 14:00 after HDBR. Amplitude for 24 h tended to attenuate during bed rest (BR), and significantly increased after BR. The results of this study suggest that the circadian rhythm of SBP and HR were maintained by strict control of sleep, awakening and food intake in microgravity model of a long-term BR state. However, the tendency to decrease 24-h cyclic amplitude of SBP appeared to be the rhythmic modulation related to cardiovascular deconditioning.

Patients' attitude toward consultations by a physician without a white coat in Japan.

OBJECT: To know how Japanese patients perceive their physicians without a white coat during consultations. SUBJECTS AND METHODS: The patients who visited a university clinic were divided into two groups: those seen by a physician in a white coat (the white-coat group) and those seen by a physician in private clothes (the private-clothes group). Questionnaires were distributed to the patients, which asked the tension and satisfaction of consultations as well as their preference for physician's attire. The answers of the white-coat group were compared with those of the private-clothes group. RESULTS: The percentage of new patients who felt tense during consultations was greater in the white-coat group (42%) than in the private-clothes group (33%). Seventy-one percent of the patients in the white-coat group preferred physicians in a white coat whereas only 39% preferred so in the private-clothes group (p<0.0001). However, the degree of patients' satisfaction for the consultation showed no statistical difference between the groups. Sixty-nine percent of the patients older than or equal to 70 years preferred a white coat while 52 percent of the patients younger than 70 years preferred so (p=0.002). CONCLUSION: Physician's white coats did not influence the satisfaction with the consultations for most Japanese patients in a university clinic, although elderly patients as well as those seen by a physician in a white coat tended to prefer the white coat to the private clothes. Furthermore, practice without a white coat might reduce patients' tension during their first consultation.

Production of interleukin-3 by murine central nervous system neurons.

We examined expression and production of interleukin-3 (IL-3) mRNA and IL-3 protein in mouse primary cultured neurons and glia by the reverse transcription and polymerase chain reaction and a bioassay using an IL-3-dependent cell line. IL-3 mRNA was demonstrated mainly in hippocampal neurons but not in glia, while a small but definite production of bioactive IL-3 was detected in septal and hippocampal neuronal cultures. Thus, endogenous IL-3 might be produced by certain neurons in situ.

[Changes in hemodynamics and catecholamines during single-level exercise at the anaerobic threshold and 120% of the anaerobic threshold in normal subjects].

Exercise training usually involves the sustained performance of exercise at a prescribed intensity. The effects of exercise performed at the anaerobic threshold (AT) have been widely studied. The effects of single-level exercise on catecholamines and cardiac function were assessed at the AT, and at 120% of the AT in eight healthy Japanese men (mean age 21.9 +/- 1.8 years). 1) Symptom-limited exercise testing utilized the ramp protocol with a bicycle ergometer (20 watts/min) for measuring AT and peak oxygen uptake (peak VO2). 2) Exercise testing was repeated on another day, following the same protocol, with blood sampled to measure norepinephrine (NE) and epinephrine (E) in the resting control state and at the AT and peak exercise. 3) Single-level exercise testing at the AT and at 120% of AT utilized the bicycle ergometer on yet another day. Blood for measurement of NE and E was drawn at 3 and 7 min after achieving a steady-state condition. In addition, the cardiac index (CI) and stroke index (SI) were measured by the CO2 rebreathing method. (1) Mean AT and peak VO2 were 18.3 +/- 1.3 and 40.2 +/- 3.0 ml/min/g, respectively. (2) NE and E measured during ramp exercise testing increased rapidly when the intensity of exercise exceeded the AT. NE measured after 3 and 7 min at the AT during single-level exercise equalled 94.7% and 94.5% of the NE value measured at the AT of ramp exercise, respectively. NE measured after 3 and 7 min at 120% of the AT during single-level exercise was 124.7% and 144.7% at the AT of ramp exercise, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial pulse pressure and vasopressin release in humans during lower body negative pressure.

The hypothesis was tested that narrowing of arterial pulse pressure (PP) is a determinant of arginine vasopressin (AVP) release in humans. Six normal males completed a two-step lower body negative pressure (LBNP) protocol of -20 and -50 mmHg, respectively, for 10 min each. None of these subjects experienced presyncopal symptoms. Arterial plasma AVP and plasma renin activity (PRA) (at 2-min intervals) only increased subsequent to a decrease in PP (invasive brachial arterial measurements) and stroke volume (ultrasound Doppler technique, n = 4). Simultaneously, mean arterial pressure did not change. A selective decrease in central venous pressure and left atrial diameter (echocardiography, n = 4) at LBNP of -20 mmHg did not affect AVP or PRA, whereas arterial plasma norepinephrine increased (n = 4). During LBNP, significant (P < 0.05) intraindividual linear correlations were observed between log(AVP) and PP in four of the subjects with r values from -0.75 to -0.99 and between log(PRA) and PP in all six subjects with r values from -0.89 to -0.98. In conclusion, these results are in compliance with the hypothesis that narrowing of PP in humans during central hypovolemia is a determinant of AVP and renin release.

Carotid baroreflexes and plasma vasopressin in humans during head-up tilt.

To investigate the influence of carotid baroreflexes on plasma arginine vasopressin (AVP) in humans, eight healthy males underwent two sessions of passive head-up tilt to 60 degrees for 15 min each. During one of the sessions (sequence randomized), carotid baroreflexes were simultaneously stimulated by static neck suction of 23 +/- 1 mmHg during the whole period of head-up tilt. Only subjects who did not develop presyncopal symptoms during head-up tilt were included. Head-up tilt increased AVP significantly from 1.0 +/- 0.3 to 4.2 +/- 1.3 pg/ml (P less than 0.05). In contrast to this, AVP did not at any point in time increase significantly during head-up tilt when neck suction was applied. Plasma renin activity and heart rate were unaffected by neck suction, whereas mean arterial pressure and central venous pressure decreased. We conclude that the moderate but significant increase in plasma AVP during nonhypotensive head-up tilt is in part mediated by deloading of carotid baroreceptors induced by the acute fall in hydrostatic pressure at the level of the carotid sinus.

Plasma volume, fluid shifts, and renal responses in humans during 12 h of head-out water immersion.

Changes in plasma volume (PV) throughout 12 h of thermoneutral (34.5 degrees C) water immersion (WI) were evaluated in eight subjects by an improved Evans blue (EB) technique and by measurements of hematocrit (Hct), hemoglobin (Hb), and plasma protein concentrations (Pprot). Appropriate time control studies (n = 6) showed no measurable change in PV. At 30 min of immersion, EB measurements demonstrated an increase in PV of 16 +/- 2% (457 +/- 70 ml). Calculations, however, based on concomitant changes in Hct, Hb, and Pprot showed an increase in PV of only 6.9 +/- 0.9 to 10.0 +/- 0.8% at 30 min of WI. PV values based on EB measurements subsequently declined throughout WI to (but not below) the preimmersion level. Concomitantly, changes in PV calculated from Pprot values remained increased, whereas estimations of changes in PV based on Hct and Hb values returned to prestudy levels after 4 h of immersion. It is concluded that PV initially increases by 16 +/- 2% during WI and does not decline below preimmersion and control levels during 12 h of immersion despite a loss of 0.9 +/- 0.2 liter of body fluid. Furthermore, changes in Hct, Hb, and Pprot do not provide accurate measures of the changes in PV during WI in humans.

[Daily activity evaluated from total energy consumption in the chronic stage of myocardial infarction and limiting factors in elder patients].

In chronic case of myocardial infarction (OMI), alternation of a daily total energy consumption (DTEC) between in OMI and in the pre-infarction stage was investigated. The limiting factors of DTEC, including functional classification according to New York Heart Association (NYHA) subset, Forrester's hemodynamic subset (FS) in the stage of acute myocardial infarction (AMI), numbers of significant coronary arterial stenosis (NCAG), cardiac function at rest in OMI, for example; cardiac index (CI), pulmonary capillary wedge pressure (PCW), left ventricle end-diastolic pressure (EDP) and exercise tolerance in OMI, were considered. Subjects, consisting of 191 OMI cases, were classified into the younger group less than 59 years old (79 males and 10 females) and the older group greater than 60 years old (102 males and 23 females). Daily physical activity was examined by questionnaires from these patients and DTEC was calculated based on daily physical activity. Results in the younger group and older group were investigated separately. Reduction of DTEC after myocardial infarction was recognized in all ages and both sexes, however, reduction of DTEC in the older group was less than in the younger group, especially in males. Concerning the limiting factors of the older group, exercise tolerance in OMI was related to reduction of DTEC. NYHA category, FS in the AMI stage, NCAG, CI, PCW and EDP had no significant relation to DTEC. In addition, the effects of social limiting factors, for instance retirement, and mental limiting factors were considered to be important.

A case of epicardial cyst.

A rare case of epicardial cyst diagnosed at surgery was presented. A 64-year old woman was admitted for evaluation of a mediastinal mass shown by echocardiography to be adjacent to both ventricles. Computed tomography (CT) and magnetic resonance imaging (MRI) studies were performed. On CT, there was evidence of an abnormal mass lesion at the lateral side of the outlet of the right ventricle. The CT number of the mass was 24.7, suggesting cystic lesion. MRI revealed that the intensity of the lesion signal was higher than that of subcutaneous fat on the T2 weighted image. On the T1 weighted image, a low intensity was identified in the same region. During operation a mass originating from the epicardium was diagnosed as an epicardial cyst.

Trophic effect of granulocyte-macrophage colony-stimulating factor on central cholinergic neurons in vitro.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) elevated choline acetyltransferase (ChAT) activities of mouse septal neurons as well as of cholinergic hybridoma line cells SN6.10.2.2 in vitro. It augmented ChAT activities and neurite extension of interleukin 3-activated cholinergic neurons. Thus, GM-CSF should be added as a trophic factor for central cholinergic neurons.

An acute state of a daily physical activity in the chronic stage of myocardial infarction and a proposal of an optimal exercise therapy.

An optimal target of exercise therapy for the chronic stage of myocardial infarction (OMI) was proposed by investigating a daily total energy consumption (DTEC) in 172 outpatients (142 males and 30 females) with OMI. DTEC was significantly lower in OMI than in the preinfarction state: 2005.8 +/- 487.8 vs. 2451.6 +/- 631.7 Kcal (p less than 0.01) in the male, 1389.9 +/- 367.4 vs. 1626.2 +/- 426.0 Kcal (p less than 0.01) in the female. Limiting factors of a daily physical activity (DPA) in OMI were selected from various non-cardiac and cardiac factors by using multifactorial analysis (Hayashi III). Non-cardiac limiting factors included; age of greater than 60, house-wife, joblessness and female, sex, and cardiac limiting factors included; NYHA class II, III, low anaerobic threshold (AT), treadmill exercise tolerance of less than 6 min, Forrester subset III, IV, heart failure in OMI and the recurrence of MI. Eighty percent of patients without cardiac limiting factors restricted DPA by 25% of DTEC of the preinfarction state. Our optimal target of exercise therapy for OMI was set to resume DTEC up to the level before MI. For patients without exercise habits, activities requiring 100 to 150 Kcal a day were requested. Also, this regimen had an educational purpose to obtain self-confidence both mentally and physically and was expected to raise the level of DPA to that of preinfarction state.

[Influence of aging on coronary arterial morphology, exercise tolerance and daily physical activity in the chronic stage of myocardial infarction].

Coronary angiographic (CAG) findings, exercise tolerance and daily physical activity were studied with reference to aging in 314 cases of the chronic myocardial infarction and in 199 cases of angina pectoris. Exercise tolerance was evaluated by a symptom-limited treadmill test and the daily physical activity by the functional classification of the New York Heart Association (NYHA) based on questionnaires filled out by the patients. Although the single to multivessel disease ratio decreased with age, there was no significant trend in diffuse or segmental character of stenosis with age. In addition, more than 80% of patients showed good exercise tolerance of more than stage II in Bruce's protocol. However, there was a general trend towards decrease in exercise tolerance with age. Furthermore approximately 80% of patients showed a good daily activity. However, the NYHA (I + II) to NYHA (III + IV + cardiac death) ratio was lower in patients aged 60 or more compared to those under age 60. Patients aged 60 or more with single vessel disease had lower daily physical activity compared to the under 60 age group, although this did not seem to be related to any physical limitation. Therefore, social and occupational aspects as well as the clinical severity of ischemic heart disease should be considered in the treatment of elderly cases.

Variant angina due to deficiency of intracellular magnesium.

A 51-year-old man was diagnosed as having variant angina by documentation of typical ST elevation during anginal attack and also by showing coronary arterial spasm (#2 and #12) during hyperventilation on coronary arteriography. Large quantities of calcium blocking agents and nitrates could not improve his symptoms. Lack of intracellular magnesium was suspected from a daily excretion of urine magnesium (5.3 mEq) and magnesium tolerance test (56.7%). After hourly infusion of magnesium sulfate (80 mEq), coronary spasm could not be induced by ergonovine.

Interleukin 3 as a trophic factor for central cholinergic neurons in vitro and in vivo.

We have found that interleukin 3 (IL-3), a growth factor for hematopoietic cells, is a novel trophic factor for mouse and rat central cholinergic neurons. It enhanced neurite outgrowth and elevated choline acetyltransferase activity. The effect seems to be specific for cholinergic neurons, since somatostatin release and glutamic acid decarboxylase and 2',3'-cyclic nucleotide 3'-phosphodiesterase activities were not significantly influenced by IL-3. In vivo, IL-3 was infused into the lateral ventricles of rats after unilateral axotomy of the septohippocampal pathways. Two weeks later, the IL-3-treated animals showed significant numbers of acetylcholinesterase-positive neurons remaining in the septal region.

Developmental and differential expression of beta amyloid protein precursor mRNAs in mouse brain.

S1 nuclease analysis was used to determine the levels and patterns of three beta amyloid protein precursor (BPP) mRNAs in mouse developmental brain and in primary neuronal and glial cultures. BPP695 mRNA lacking the Kunitz proteinase inhibitor (KPI) domain was detected exclusively in neuronal cultures and increased considerably in late embryonic and early postnatal periods. On the other hand, BPP751 and 770 mRNAs with KPI domain were detected predominantly in astrocyte- and microglia-enriched cultures and increased slightly only in embryonic stages. These results suggest that the product of each BPP mRNA may play a different role in the brain.

Detection of fatty tissue in the myocardium by using computerized tomography in a patient with arrhythmogenic right ventricular dysplasia.

A case with arrhythmogenic right ventricular dysplasia involving the left ventricle as well as the right ventricle was presented. Right ventricular endomyocardial biopsy and computerized tomography were useful in detecting fatty tissue in the myocardium. This case deserves to be reported in reference to detecting fatty tissue in arrhythmogenic right ventricular dysplasia by using computerized tomography.

[Psychological background as a risk factor of variant angina].

In this study, the role of psychological make-up was assessed as a risk factor in the etiology of vasospasm in variant angina (VA) using the Cornell Medical Index (CMI). Study subjects consisted of 15 patients with VA; 32 with effort angina or old myocardial infarction having no vasospasm (EA + OMI); and 34 healthy men. For a neurosis discriminative diagram, the areas I and II were judged as normal and the areas III and IV were judged compatible with a neurotic disorder. Correlation of serum lipid levels with psychological factors was attempted. 1. Among the VA patients, 46.7% belonged to the areas III and IV, as compared to 18% of the patients with EA + OMI, and 2.6% of the healthy subjects. 2. Seventy-three percent of the VA group showed anxiety states indicating a correlation with a psychological disorder. 3. A majority of the VA patients had a variety of psychological symptoms unrelated to myocardial ischemia. 4. Total cholesterol, triglycerides, LDL cholesterol, serum uric acid and the atherogenic index were all lower in the VA group than in the EA + OMI group. 5. In the EA + OMI group, triglycerides, serum uric acid and the atherogenic index were higher in the psychological group than in the non-psychological group. However, total cholesterol, LDL cholesterol and HDL cholesterol were lower in the former than in the latter group. It was concluded that an anxiety state constitutes a contributing background for developing VA and it was speculated that such an anxiety state may lead to an exaggerated secretion of stress hormones, resulting in vasospasm of the coronary arteries.

[Variant angina due to deficiency of intracellular magnesium by anorexia nervosa].

A 51-year-old man who had a past history of gastric resection for medically uncontrollable gastric ulcer has loss of appetite that recurs periodically. And he has frequently presented spontaneous angina early in the morning since 1984. He was diagnosed as having variant angina by the documentation of typical ST elevation during anginal attack and also by showing coronary artery spasm (#2 and #12) during hyperventilation on coronary arteriography. A large quantity of calcium blocking agents and nitrates could not improve his symptoms. Lack of intracellular magnesium by loss of appetite was suspected from a daily excretion of urine magnesium (5.3 mEq) and magnesium tolerance test (56.7%). To confirm the effect of magnesium administration, the second coronary arteriography was performed. After magnesium sulphate (80 mEq, hourly) was injected, coronary artery spasm could not be induced by ergonovine. And orally magnesium oxide, calcium blocking agents and nitrates were started. Anginal attack disappeared with increasing urine magnesium.