A model of plasma current through a hole of Rogowski probe including sheath effects.

In TST-2 Ohmic discharges, local current is measured using a Rogowski probe by changing the angle between the local magnetic field and the direction of the hole of the Rogowski probe. The angular dependence shows a peak when the direction of the hole is almost parallel to the local magnetic field. The obtained width of the peak was broader than that of the theoretical curve expected from the probe geometry. In order to explain this disagreement, we consider the effect of sheath in the vicinity of the Rogowski probe. A sheath model was constructed and electron orbits were numerically calculated. From the calculation, it was found that the electron orbit is affected by E × B drift due to the sheath electric field. Such orbit causes the broadening of the peak in the angular dependence and the dependence agrees with the experimental results. The dependence of the broadening on various plasma parameters was studied numerically and explained qualitatively by a simplified analytical model.

The effects of season and exercise on the levels of plasma polyunsaturated fatty acids and lipoprotein cholesterol in young rats.

Plasma concentrations of polyunsaturated fatty acids (20:4(n - 6), 20:5(n - 3), 22:6(n - 3)) and high- or low-density lipoprotein cholesterols (HDL-C, LDL-C) in young rats were measured to elucidate a possible relationship between the levels of [20:5(n - 3)] [20:4(n - 6)]-1, [22:6(n - 3)] [20:4(n - 6)]-1 and [LDL-C] [HDL-C]-1. Seasonal change in [LDL-C] [HDL-C]-1 in the sedentary and exercised rats was found to correlate with the respective values of [20:5(n - 3)] [20:4(n - 6)]-1 and/or [22:6(n - 3)] [20:4(n - 6)]-1. Moderate exercise in summer decreased plasma arachidonic acid (20:4(n - 6)). With the decrement of the 20:4(n - 6) acid, the ratios of [20:5(n - 3)] [20:4(n - 6)]-1 and [22:6(n - 3)] [20:4(n - 6)]-1 increased to a greater degree. The [LDL-C] [HDL-C]-1 values in this case were inversely associated with the levels of [22:6(n - 3)] [20:4(n - 6)]-1. We therefore suggest that moderate physical training in summer protects arteries from thrombogenesis and lipid accumulation.

Protective effects of calcium channel blockers on hydrogen peroxide induced increases in endothelial permeability.

STUDY OBJECTIVE: The aim was to examine the effects of calcium channel blockers on the permeability of endothelial cells and to determine whether these agents could protect against increases in endothelial permeability induced by hydrogen peroxide (H2O2). DESIGN: Endothelial cells were cultured on collagen coated micropore filters. When they were confluent on the filter, albumin transfer and electrical resistance across the endothelial monolayers were measured. EXPERIMENTAL MATERIAL: Endothelial cells were obtained from human umbilical veins. The cells at the 2nd to 4th passage were used for the experiments. MEASUREMENTS AND MAIN RESULTS: Nilvadipine (10(-8) M) suppressed endothelial albumin transfer by 37.2% (p less than 0.01) and enhanced electrical resistance by 25.8% (p less than 0.01), whereas nicardipine (10(-7) M), diltiazem (10(-7) M), and verapamil (10(-7) M) had no significant effect on either variable without the addition of H2O2. H2O2(0.2 mM) increased albumin transfer by 164% (p less than 0.01) and reduced electrical resistance by 67% (p less than 0.01) across endothelial monolayers without endothelial cell lysis. Nilvadipine (10(-8) M) and nicardipine (10(-7) M) inhibited the (0.2 mM) H2O2 induced increases in endothelial albumin transfer and decreases in electrical resistance more strongly than diltiazem and verapamil, although all of these agents significantly reduced such injury. CONCLUSIONS: Nilvadipine is a potent inhibitor of endothelial permeability and of hydrogen peroxide induced increases in permeability.

Effects of diltiazem hydrochloride on cardiovascular response, platelet aggregation and coagulating activity during exercise testing in systemic hypertension.

The effects of diltiazem hydrochloride on exercise-induced changes in cardiovascular response, plasma renin activity, platelet function and blood coagulability were evaluated with multistage treadmill exercise in 20 patients who had systemic hypertension of stage 1 to 2 (World Health Organization classification). Heart rates, blood pressure, and pressure-rate product at rest, at peak exercise and in the recovery period were significantly reduced after 4 weeks of diltiazem administration, 180 mg/day. Plasma renin activity tended to increase after the medication. However, platelet adenosine diphosphate-induced aggregation sensitivity, prothrombin time, activated partial thromboplastin time, plasma fibrinogen concentration and antithrombin III activity did not change significantly. It is concluded that diltiazem could ameliorate the hyperresponsiveness of heart rate and BP to exercise in hypertensive patients without affecting blood coagulability.

Effects of enalapril on the cardiovascular response to treadmill exercise in patients with mild to moderate systemic hypertension.

The effects of the angiotensin converting enzyme inhibitor enalapril on exercise-induced changes in blood pressure and heart rate were evaluated in 15 patients in the early stages of systemic hypertension. Multistage treadmill exercise was performed before and after eight weeks of enalapril administration, and the results of the two trials were compared. In patients at rest, enalapril decreased systolic blood pressure from 172 +/- 18 to 147 +/- 14 mmHg and diastolic blood pressure from 99 +/- 9 to 88 +/- 8 mmHg (both P less than 0.001). In patients at peak exercise, enalapril decreased systolic blood pressure from 216 +/- 13 to 195 +/- 18 mmHg and diastolic blood pressure from 106 +/- 12 to 99 +/- 12 mmHg (both P less than 0.001). There was also a significant decrease in blood pressure during the recovery period after treadmill exercise. Enalapril reduced heart rate at peak exercise (P less than 0.05), but not at rest or during recovery. Thus enalapril alleviated the response of blood pressure to exercise in hypertensive patients and may help prevent hypertensive complications during daily activities.

Effects of oral elastase on lipid metabolism, platelet function, and blood coagulability in patients with diabetes mellitus.

Lipid metabolism, platelet function, and blood coagulability were evaluated in 20 patients with diabetes mellitus and stable fasting blood sugar levels before, during, and after treatment with the pancreatic enzyme elastase for 16 weeks. Serum high-density lipoprotein cholesterol levels increased from 46.9 mg/dl before treatment to 53.2 mg/dl after treatment (P less than 0.001) and serum triglyceride levels decreased from 151.4 to 125.4 mg/dl (P less than 0.05); no significant changes in total cholesterol levels were noted. Platelet counts in whole blood and in platelet-rich plasma increased from 17.1 and 27.5 X 10(4)/mm3, respectively, to 19.8 and 31.3 X 10(4)/mm3 after treatment (P less than 0.01 and less than 0.05). Plasma beta-thromboglobulin levels decreased from 117.0 to 72.7 ng/ml after treatment (P less than 0.001). No significant changes in platelet sensitivity to adenosine diphosphate aggregation were noted. Plasma fibrinogen and antithrombin III levels increased from 421.0 and 25.8 mg/dl, respectively, to 470.6 and 32.0 mg/dl after treatment (P less than 0.05 and less than 0.001). It is concluded that, since it has been shown that elastase improved lipid metabolism, inhibited platelet release, and increased antithrombin III levels, it may play a useful role in the prevention of vascular complications in diabetic patients.

Elevation of factor VII activity and mass in coronary artery disease of varying severity.

The present study was undertaken to determine whether the extent of Factor VII elevation correlated with the severity of coronary artery disease and whether zymogen or activated Factor VII was responsible for this elevation. A group of 69 patients with coronary artery disease with old myocardial infarction was compared with 28 control subjects. The patient groups showed elevated levels of Factor VII procoagulant activity (FVII:C) and more markedly elevated Factor VII antigen (FVII:Ag) levels than the control group; therefore they had a decreased FVII:C to FVII:Ag ratio. The increased Factor VII level in the patient groups was caused by elevated Factor VII zymogen levels, and not by activated Factor VII. Since FVII:C levels strongly correlated with the titer of thrombin-antithrombin III complexes in all patients, the hypercoagulable state accompanying severe coronary atherosclerosis seems to underlie the increase of FVII and TAT in the stable phase of myocardial infarction.

Blood coagulability and fibrinolytic activity before and after physical training during the recovery phase of acute myocardial infarction.

The effects of physical training on hemostatic parameters were evaluated in 56 postmyocardial infarction (MI) patients before and after one month of systematic physical training and in 30 control post-MI patients, who did not undergo such training. There were no significant changes in prothrombin time (PT) and alpha 1-antitrypsin (alpha 1AT) at the beginning and end of the study in either group. Levels of fibrinogen, Factor VIII: C (VIII:C) and von Wildebrand antigen (vWf:Ag), and activities of ATIII and plasminogen (Plg) were significantly decreased in the group with physical training (p less than 0.05), while values were unchanged in the control group. Hematocrit, platelet counts, and alpha 2-plasmin inhibitor (alpha 2PI) activities also decreased in the physical training group (p less than 0.05). In contrast, these variables increased in the control group (p less than 0.05). Activated partial thromboplastin time (aPTT) tended to be prolonged in the group with physical training, while it was shortened in the control group. In a subset of 20 patients with physical training, resting levels of plasmin-alpha 2PI complex (PIC), thrombin-antithrombin III complex (TAT), protein-C (P-C:Ag), plasminogen activator inhibitor-1 (PAI-1), VII:C, and P-C activities had significantly decreased after one month of physical training (p less than 0.05), although tissue plasminogen activator activities remained unchanged. Physical training appeared to suppress coagulability as indicated by the decrease in fibrinogen, VIII:C, vWf:Ag, VII:C, and TAT, and prolongation of aPTT. The decrease in plasminogen, t-PA:Ag, alpha 2PI, PAI-1, and PIC after physical training may result from the decreased coagulability. In conclusion, physical training appears to induce a suppression of the coagulation system in patients in the recovery phase of MI.

[Bone mineral contents of lumbar vertebrae in postmenopausal women--using a quantitative computed-tomography method].

We measured bone mineral contents of lumbar vertebrae (L1, L2, L3, L4) in 58 post-menopausal female volunteers (49-76 years old), using a quantitative computed-tomography method. We investigated age-related changes of bone mineral content, and analyzed the relation of bone mineral content to vertebral deformity and to physical characteristics. The following results were obtained: (1) There were highly significant correlations and some significant differences among bone mineral contents of L1, L2, L3 and L4. (2) Bone mineral content showed an apparently linear decline with age. (3) A significant negative correlation was observed between bone mineral content and the central deformity index of the vertebral body, but not for the anterio-posterior deformity index. (4) It was difficult to verify an association of bone mineral content with physical characteristics, such as height, weight, and body mass index.

The relationship between the ambulatory variability and the laboratory reactivity of blood pressure and heart rate.

We examined the relationship between the ambulatory variability and the laboratory reactivity of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) in 21 male college students. The mean increase during the waking period from that during sleep was defined as variability 1, and the standard deviation of the ambulatory measurements during waking was defined as variability 2. The reactivity to laboratory tests was measured by the pretask-to-task increase in variables. The high SBP variability 1 group showed a significantly higher reactivity of SBP and noradrenaline in the bicycle exercise test (70w). This suggests the possibility that SBP variability 1, can be predicted by increased reactivity to a mild limb exercise test. The high HR variability 1 group, and the high SBP variability 2 group showed significantly lower reactivity of stroke volume (SV) and cardiac output (CO) in the cold face test. Thus, parasympathetic responses such as trigeminal-brainstem-vagal pathway function or baroreflex sensitivity seemed to be reduced in these groups. The high DBP variability 2 group showed significantly lower DBP reactivity in the cold face test, and low noradrenaline reactivity in the mental arithmetic test, which indicated a reduced alpha-adrenergic response in this group. No other significant differences in reactivity to the laboratory mental stress tests were found between the variability 1 and variability 2 groups.

[Clinical evaluation of plasma atrial natriuretic polypeptide in patients with respiratory failure in pulmonary tuberculosis].

We previously reported the clinical role of plasma immunoreactive atrial natriuretic polypeptide (ANP) and cyclic GMP in patients with respiratory diseases, bronchial asthma (BA), chronic pulmonary emphysema (CPE) and pulmonary insufficiency induced by pulmonary tuberculosis (TBC). In this study, moreover, we divided patients with respiratory failure induced by tuberculosis sequelae into two groups, patients with oxygen therapy group [O2 (+) group] or ordinary practical treatment group [O2 (-) group], and we evaluated the difference of the roles of ANP in two groups and the correlation of ANP and c-GMP with clinical findings, blood gas analysis, electrocardiogram, chest roentogen photography and spirogram in two groups. In conclusion, the respiratory failure in patients with tuberculosis sequelae is compensated by increased cardiac output, and that causes the rising of right atrial pressure. These results show, addition to the basic effects of ANP, the concentration of plasma ANP is released with relating the degree of respiratory failure.

[In vitro susceptibilities of Mycobacterium avium and Mycobacterium intracellulare to new macrolides, new quinolones, and antituberculous drugs on Dubos agar medium].

Mycobacterium avium and M. intracellulare were isolated from the sputum of patients infected with atypical mycobacteria using 1% Ogawa medium and identified by the DNA probe test. Then the MICs of various kinds of drugs against these mycobacterial species were determined on Dubos agar medium, and the drug susceptibilities were also determined on 1% Ogawa medium in parallel. The drugs tested were new macrolides, such as clarithromycin (CAM) and roxithromycin (RXM), new quinolones, such as ofloxacin (OFLX) and ciprofloxacin (CPFX), and antituberculous drugs, such as isoniazid (INH), rifampicin (PFP), streptomycin (SM), and ethambutol (EB). The MICs of the drugs tested, especially those of CAM, OFLX, and RFP, when determined on Dubos agar medium, were generally lower against M. intracellulare than against M. avium. The susceptibilities of the mycobacterial isolates tested to RFP and SM determined on Dubos agar medium were markedly different from those determined on 1% Ogawa medium. Such discrepancies may be accounted for by absorption of these drugs to the egg medium and instability of RFP in the egg medium. Overall, our results indicate that the new macrolides and new quinolones are effective against atypical mycobacteria.

[Changes induced by venous occlusion in coagulation and fibrinolysis in patients with old myocardial infarction].

The levels of hemostatic and fibrinolytic parameters and of molecular markers in venous blood before and after 10 minutes of venous occlusion were measured to evaluate vascular endothelial function in 36 patients with old myocardial infarction, and also in 20 healthy subjects. T-PA activity in the venous blood after occlusion was significantly lower in the patient group compared with the control group, and was lowest in patients with diabetes mellitus. These results were considered to be attributable to elevated PAI-1 and alpha 2 PI levels in these patients. The mean levels of t-PA antigen and VIII R: Ag in venous blood before occlusion were significantly higher in the patient group, but the mean amount of release was no higher in patients than in controls. The plasmin.alpha 2PI complex levels before venous occlusion seemed to indicate the presence of secondary fibrinolysis accompanying hypercoagulability, and the level was significantly higher in patients with diabetes mellitus. Venous occlusion induced the release of t-PA and VIII R: Ag without causing a significant difference in the mean amount of increase of these substances in patient and control groups. However, the lower level of t-PA activity after venous occlusion together with the higher levels of VIII: C, VIII R: Ag, alpha 2PI, PAI-1, and plasmin.alpha 2PI complex before venous occlusion in the patients, indicated that the patient group was in a hypercoagulable and hypofibrinolytic state. In those with diabetes mellitus, the changes were more significant.

Note: Multi-pass Thomson scattering measurement on the TST-2 spherical tokamak.

In multi-pass Thomson scattering (TS) scheme, a laser pulse makes multiple round trips through the plasma, and the effective laser energy is enhanced, and we can increase the signal-to-noise ratio as a result. We have developed a coaxial optical cavity in which a laser pulse is confined, and we performed TS measurements using the coaxial cavity in tokamak plasmas for the first time. In the optical cavity, the laser energy attenuation was approximately 30% in each round trip, and we achieved a photon number gain of about 3 compared with that obtained in the first round trip. In addition, the temperature measurement accuracy was improved by accumulating the first three round trip waveforms.

Local current density measurement using a Rogowski probe in Tokyo Spherical Tokamak-2.

A Rogowski probe consisting of a small multi-layer Rogowski coil, five magnetic pick-up coils, and a Langmuir probe was developed to measure the local current density and its direction. It can be moved along the major radius and can be turned around its axis. This probe was used to measure the current density profile near the last closed flux surface of Ohmic plasmas in Tokyo Spherical Tokamak-2. The current density profile was measured successfully with a signal to noise ratio of greater than 20.

Demonstration of improvement in the signal-to-noise ratio of Thomson scattering signal obtained by using a multi-pass optical cavity on the Tokyo Spherical Tokamak-2.

The multi-pass Thomson scattering (TS) scheme enables obtaining many photons by accumulating multiple TS signals. The signal-to-noise ratio (SNR) depends on the accumulation number. In this study, we performed multi-pass TS measurements for ohmically heated plasmas, and the relationship between SNR and the accumulation number was investigated. As a result, improvement of SNR in this experiment indicated similar tendency to that calculated for the background noise dominant situation.