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Biomedical subjects

M Chida

Publications and source records attributed to M Chida.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Radioaerosol inhalation and perfusion imaging studies in immediate postoperative phase after lobectomy].

In order to determine the changes in pulmonary ventilation-perfusion imaging after lobectomies, we examined 11 patients using radioaerosol inhalation and perfusion scintigraphies, before and after the operations. We employed 99mTc-labeled albumin aerosol generated by a jet nebulizer for the inhalation imaging, and 99mTc-labeled macroaggregated albumin for the perfusion imaging, respectively. Prior to the operations, there were no (major) defects of imagings on the lung fields. Immediately after the operations, however, we could not detect any abnormal findings on chest roentgenograms, we found detects of imagings on the lung fields in either inhalation or perfusion scintigraphy whose area were mismatching. It took more than 3 weeks for these defects of imagings to disappear. In conclusion, these findings suggest that postoperative hypoxemia might be occurred by these mismatchings.

Administration, Inhalation↗
PubMed1991

Ratings of perceived exertion in chronic obstructive pulmonary disease--a possible indicator for exercise training in patients with this disease.

The purpose of this study was to evaluate the usefulness of ratings of perceived exertion (RPE) as an indicator of exercise intensity in patients with chronic obstructive pulmonary disease (COPD). The subjects were ten male patients with COPD, whose mean forced expiratory volume in 1 s was 1.09 1, SD 0.41, and ten healthy middle-aged men. Ramp incremental exercise on a cycle-ergometer was performed and RPE was determined by the Borg 15-point scale. The absolute oxygen uptake at each RPE was significantly greater in the healthy subjects than in the patients with COPD. However, oxygen uptake calculated as a percentage of maximal at any RPE did not differ significantly between the two groups. Arterial blood lactate concentration at points 15 to 19 on the RPE scale was increased in healthy subjects (P less than 0.05-P less than 0.001), while the dyspnoea index at points 11 to 19 on the RPE scale was higher in patients with COPD (P less than 0.05-P less than 0.001). The main complaints on stopping exercise were dyspnoea in the patients with COPD and fatigue in the healthy subjects. Although the nature of RPE may have been different in the two groups, RPE could be a possible indicator of exercise intensity when physicians prescribe exercise to patients with COPD.

Adult↗
PubMed1991

FCR system in Hokkaido University Hospital.

The complete digital x-ray system using FCR is now being used in daily diagnosis as a part of the picture archiving and communications system (PACS) in Hokkaido University (HU) Hospital. This project is based on a 3-year plan started in 1988. In the first year (1988), six Fuji Computed Radiography (FCR) units (two FCR501, one FCR502, three FCR7000), PACS interfaces, and an optical disk system were installed. In the first year, about 60% of x-ray filming changed from the conventional technique to the FCR, and 60% of FCR images were transferred to PACS. In the second year, we began to use FCR in gastrointestinal (GI) study with two additional FCR7000s and three x-ray TV units. Then the percentage of plain films made by FCR increased to 80%. In the third year, angiographic studies will be converted to FCR. A specially designed built-in type FCR is under development to examine the entire spine. When this project is complete, almost all conventional radiography except chest tomography will be performed by FCR. The tomography x-ray computed radiography (CR) unit with automatic-imaging plate (IP) changer is expected to be developed soon.

Radiology Information Systems↗
PubMed1991

Ventilatory response and arterial potassium concentration during incremental exercise in patients with chronic airways obstruction.

The relationship of ventilation response (VE) to arterial potassium concentration (K+) during ramp incremental exercise was assessed in nine patients with chronic obstructive pulmonary disease (COPD), and in 10 healthy subjects. For COPD patients the maximum oxygen uptake (VOmax) was 19.6 +/- 3.8 ml kg-1 min-1 (+/- SD), and percentage of forced expired volume at 1 s (% FEV1) was 47.8 +/- 10.4%. In healthy subjects, VO2max was 44.4 +/- 7.0 ml kg-1 min-1 and FEV1 was 89.7 +/- 7.4%. Breath-by-breath determinations for VE, oxygen uptake (VO2) and carbon dioxide output (VCO2), as well as determinations for K+, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), pH and lactate in arterial blood were performed during a workout on an exercise bicycle at a ramp function work rate of 20 W min-1, preceded by a 40 min warm-up period. The major findings in the present study are: (1) that there is a linear relation between ventilation and arterial K+ concentration during ramp exercise in both healthy subjects and COPD patients; (2) that the slope of the VE-K+ relationship is significantly lower in COPD patients (16.2 +/- 7.3 l min-1 mM-1) than in normal subjects (37.4 +/- 6.9 l min-1 mM-1, P less than 0.01); and, (3) that the slope of the VE-K+ relationship is significantly related to the ability to ventilate during maximal exercise in both healthy subjects and COPD patients (P less than 0.05). It is thought that the significantly reduced slope of the VE-K+ relationship in the COPD patients could be interpreted as a reduced sensitivity to the stimulus and/or as a mechanical impairment of the ventilation.

Adolescent↗
PubMed1991

[Diffuse panbronchiolitis in two brothers with different clinical courses].

Diffuse panbronchiolitis in two brothers is reported. The elder brother aged 46, was admitted in May 1983 due to severe dyspnea and productive cough, which had gradually worsened over several years. He had severe hypoxemia and hypercapnia. He died at age 47 of respiratory failure due to pseudomonas infection despite antibiotic therapy. The younger brother, at age 41, was admitted in March 1983 due to fever, productive cough, and abnormal shadows on chest X-ray films. He showed mild hypoxemia and his symptoms improved with antibiotic treatment. Since then he has been followed as an outpatient for over 7 years while taking 400 mg of Erythromycin per day, and he has had no exacerbation. These two cases had different clinical courses despite the facts that both had similar conditions of chronic sinusitis and appeared to be exposed to no special environmental or occupational hazards. These facts suggest that not only intrinsic factors, such as defenselessness of airways, but extrinsic factors such as viral, mycoplasmal, or bacterial infection may act together on the mechanisms of the onset and progression of diffuse panbronchiolitis.

Adult↗
PubMed1991

[Interleukin-2 (IL-2) in active pulmonary tuberculosis].

To clarify the precise of cellular immunity mechanism in pulmonary tuberculosis, we investigated the amount of IL-2 in patients with untreated active pulmonary tuberculosis. When serum adenosine deaminase (ADA) activity was examined using enzyme assay, an abnormally high level was observed in all patients (29.0 + 11.6 IU/ml, mean + SD; 4.5-17.8, normal range). Likewise, the level of serum-soluble interleukin-2 receptor (IL-2R) measured by ELISA showed abnormal high level in all patients (844.3 + 584.8 IU/ml; 80-300, normal range). When stimulated using PHA, the peripheral lymphocyte's ability to produce IL-2 revealed no difference between control subjects and patients. It was, however, noted that the lymphocytes of the patients significantly suppressed IL-2 responsiveness when compared to the control subjects (P less than 0.05). The serum IL-2 concentration measured using RIA could not be detected in any of the patients as was the same for control subject. All of the above mentioned results suggest that T-cell activation which caused increment in serum ADA activity and soluble IL-2R occurred in active pulmonary tuberculosis. The suppressed IL-2 responsiveness in the peripheral lymphocytes of patients proposes the possibility of soluble IL-2R reduction by the negative feedback mechanism in IL-2-sensitive lymphocytes.

Adenosine Deaminase↗
PubMed1991

[Lung function after lobectomy in chronic pulmonary emphysema].

We compared the prediction of postoperative pulmonary function in two groups: chronic pulmonary emphysema (CPE) group (n = 30) and normal control group (n = 41). These patients had a lobectomy because of lung cancer. We measured pulmonary function test (FVC, EFV1, TLC, FRC, RV, DLco), and pulmonary perfusion scan before and after surgery. We found correlation between the predicted and measured postoperative values very close in control group. Whereas, in CPE group, these correlations were very low especially in FVC and FEV1. We also calculated the pulmonary function on the operated and the non-operated sides. The correlation were very high without FEV1 in control group and all the measured values did not correlate to the predicted values. On the non-operated side, the correlations were high in both control and CPE groups. From these results we can conclude that it is difficult to predict the postoperative pulmonary function in the case of chronic pulmonary emphysema.

Chronic Disease↗
PubMed1990

Relationship between ventilation and arterial potassium concentration during incremental exercise and recovery.

The purpose of this study was to compare the relationship of ventilation (VE) with pH, arterial concentrations of potassium [( K+]a), bicarbonate [( HCO3-]a), lactate [( la]a), and acid-base parameters which would affect hyperpnoea during exercise and recovery. To assess this relationship, ten healthy male subjects exercised with intensity increasing as a ramp function of 20 W.min-1 until voluntary exhaustion and they were then allowed a 5-min recovery period. Breath-by-breath gas exchange data, [HCO3-]a, pH, [la]a, [K+]a and blood gases were determined during both exercise and recovery. Using a linear regression method, the VE/[K+]a relationship was analysed during both exercise and recovery. Several interesting results were obtained: a significant relationship between [K+]a and VE was observed during recovery as well as during exercise; the VE at any given values of [K+]a was significantly higher during recovery than during exercise and out of those factors affecting exercise hyperpnoea, only [K+]a had a similar time-course to VE during recovery. Changes in [K+]a during recovery were shown to occur significantly faster than VE with an [K+]a time constant of 70.0 s, SD 16.2 as opposed to 105.5 s, SD 10.0 for VE (P less than 0.01). These results provided further evidence that [K+]a might play an important role as a substance which can stimulate exercise hyperpnoea as has been suggested by other workers. The present study also showed that during recovery [K+]a contributed significantly to the control of VE.

Adult↗
PubMed1990

Specificity of physiological adaptation to endurance training in distance runners and competitive walkers.

The present study was designed to evaluate the specificity of physiological adaptation to extra endurance training in five female competitive walkers and six female distance runners. The mean velocity (v) during training, corresponding to 4 mM blood lactate [onset of blood lactate accumulation (OBLA)] during treadmill incremental exercise (training v was 2.86 m.s-1, SD 0.21 in walkers and 4.02 m.s-1, SD 0.11 in runners) was added to their normal training programme and was performed for 20 min, 6 days a week for 8 weeks, and was called extra training. An additional six female distance runners performed only their normal training programme every day for about 120 min at an exercise intensity equivalent to their lactate threshold (LT) (i.e. a running v of about 3.33 m.s-1). After the extra training, there were statistically significant increases in blood lactate variables (i.e. oxygen uptake (VO2) at LT, v at LT, VO2 at OBLA, v at OBLA; P less than 0.05), and running v for 3,000 m (P less than 0.01) in the running training group. In the walking training group, there were significant increases in blood lactate variables (i.e., v at LT, v at OBLA; P less than 0.05), and walking economy. In contrast, there were no significant changes in lactate variables, running v and economy in the group of runners which carried out only the normal training programme. It is suggested that the changes in blood lactate variables such as LT and OBLA played a role in improving v of both the distance runners and the competitive walkers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1990

Significance of the contribution of aerobic and anaerobic components to several distance running performances in female athletes.

To assess the most important determinant for successful distance running (800 m, 1500 m and 3000 m events) in female athletes, measurements of several anaerobic indices were made (peak power, mean power) using the Wingate anaerobic test (WAnT), and aerobic indices such as oxygen uptake (VO2) or running velocity (v) at lactate threshold (LT), VO2 or v at onset of blood lactate accumulation (OBLA), running economy (RE), and maximal oxygen uptake were determined using the incremental treadmill test. The RE was represented by a VO2 value measured at 240 m.min-1 of a standard treadmill velocity. A stepwise multiple regression analysis (SAS stepwise procedure) combined the best features of forward inclusion and backward elimination to determine the most important factors in predicting the performance of running these distances as dependent variables. The stepwise procedure showed that the blood lactate variables such as LT and/or OBLA are highly correlated with, and contributed to predicting performance running 800 m-3000 m, whereas the anaerobic component was related only to running 800 m. In conclusion, blood lactate variables account for a large part of the variation in distance running performance in female as in male runners. The component of the anaerobic system which can be measured by the WAnT was shown to contribute to performance in running 800 m, but not in longer distances.

Adult↗
PubMed1990

[Activated pulmonary intravascular macrophages increase pulmonary microvascular permeability in sheep].

Pulmonary intravascular macrophages (PIMs) reside in the alveolar capillaries of sheep lung. However, the role of PIMs activation in the mechanism of increasing pulmonary microvascular permeability is not clear. We determined, using awake sheep with chronic lung lymph fistulas, the effects of intraarterial infusion of latex beads emulsion (1 microns in diameter) on lung lymph-dynamics. Sheep were divided into 3 groups; control, low dose latex and high dose latex groups. In control group, their lymph-dynamics were stable during the experimental period. In low dose latex group (5.46 x 10(9) beads/kg), lung lymph flow increased during the infusion period, but lung lymph protein clearance did not change. In high dose latex group (5.46 x 10(10) beads/kg), lung lymph flow began to increase during the infusion period and remained high, and lung lymph protein clearance increased significantly during and after the infusion of latex beads emulsion. The latex beads mainly distributed to lungs, and 70% of the beads were caught by PIMs in their phagosomes. These findings suggest that the activation of PIMs through their phagocytic uptake of circulating microparticles increases pulmonary microvascular permeability.

Animals↗
PubMed1990

[Serum adenosine deaminase (ADA) activity in patients with active pulmonary tuberculosis].

To clarify the immunological aspect of tuberculosis, we investigated serum adenosine deaminase (ADA) activity, T and B cell percentile in total peripheral mononuclear cells, peripheral T cell subpopulation and their relationship with other inflammatory parameters in 20 patients with active pulmonary tuberculosis. Serum ADA activity showed abnormal high level in all patients in nontreated phase with significant regression after three months treatment by anti-tuberculous drugs (P less than 0.05). In addition, significant positive correlation was observed between serum ADA activity and erythrocyte sedimentation rate at 1 hour (r = 0.56). Concerning about peripheral T cell subpopulation studied by two colour flow cytometry with FITC-conjugated anti-CD4 and phycoerythrin-conjugated anti-HLA-DR antibody, there was positive correlation between CD4(-) HLA-DR(+) T cell and serum ADA activity (r = 0.59) without any abnormal frequency of each T cell subpopulation. Additionally, after the treatment of pulmonary tuberculosis, significant increase of T cell percentile in total peripheral mononuclear cells were observed (P less than 0.005). In conclusion, these results may suggest serum ADA activity could be a parameter of activity of pulmonary tuberculosis and reflect the function of activated suppressor/cytotoxic T cell.

Adenosine Deaminase↗
PubMed1989

Effect of hypoxia on arterial and venous blood levels of oxygen, carbon dioxide, hydrogen ions and lactate during incremental forearm exercise.

The purpose of the present study was to investigate whether, in humans, hypoxia results in an elevated lactate production from exercising skeletal muscle. Under conditions of both hypoxia [inspired oxygen fraction (F1O2): 11.10%] and normoxia (F1O2: 20.94%), incremental exercise of a forearm was performed. The exercise intensity was increased every minute by 1.6 kg.m.min-1 until exhaustion. During the incremental exercise the partial pressure of oxygen (PO2) and carbon dioxide (PCO2), oxygen saturation (SO2), pH and lactate concentration [HLa] of five subjects, were measured repeatedly in blood from the brachial artery and deep veins from muscles in the forearm of both the active and inactive sides. The hypoxia (arterial SO2 approximately 70%) resulted in (1) the difference in [HLa] in venous blood from active muscle (values during exercise-resting value) often being more than twice that for normoxia, (2) a significantly greater difference in venous-arterial (v-a) [HLa] for the exercising muscle compared to normoxia, and (3) a difference in v-a [HLa] for non-exercising muscle that was slightly negative during normoxia and more so with hypoxia. These studies suggest that lower O2 availability to the exercising muscle results in increased lactate production.

Adult↗
PubMed1989

Arterial blood gases, acid-base balance, and lactate and gas exchange variables during hypoxic exercise.

To determine the effect of hypoxia on lactate threshold (LT), onset of blood lactate accumulation (OBLA), and gas exchange threshold (GET), the lactate level together with VO2, VCO2, VE, and acid-base status in arterial blood from 12 female distance runners performing a progressive incremental treadmill test under the condition of hypoxic gas inhalation (HC: FIO2 is 16.0% in N2) compared with normoxic conditions (NC: FIO2 is 20.9%; i.e., air) were examined. During exercise, HC shifted LT, GET, and OBLA to a lower VO2 by 12.5%, 12.9%, and 9.3%, respectively. The GET during hypoxic exercise was well correlated with LT (GET = 0.973LT + 0.04; expressed in VO2 l.min-1). The close reciprocal changes in arterial blood lactate and bicarbonate (HCO3-) were observed during hypoxic as well as normoxic exercise. These findings provide evidence for the cause and effect relationship between LT and GET, even in hypoxic exercise. During submaximal exercise below the LT, PaCO2 and HCO3- slightly increased both in NC and HC with pH remaining unchanged. However, during exercise above the LT, the PaCO2, HCO3-, and pH all decreased with pH decreasing more markedly during hypoxia. In conclusion, this study demonstrated a clear increase in arterial lactate during hypoxic exercise above the LT. Both the LT and GET are shifted to a lower work rate by hypoxia in the same manner with the correlation between them remaining high, supporting the cause and effect relationship of these two parameters.

Acid-Base Equilibrium↗
PubMed1989

Physiological determinants of race walking performance in female race walkers.

The purpose of this study was to determine the relationship between race pace on a 5 km walking performance and velocity at the lactate threshold (V-LT), VO2 at the lactate threshold (VO2-LT), velocity at which blood lactate corresponded to 4 mM level (V-OBLA), VO2 at which blood lactate corresponded to 4 mM level (VO2-OBLA), walking economy (steady state VO2 at a standard velocity) and maximal oxygen uptake (VO2max) in eight female race walkers. A multiple stepwise linear regression analysis was employed to predict the race pace on a 5 km walking performance as dependent variable. Since V-OBLA was highly correlated to 5 km race walking performance (r = 0.94, P less than 0.001), it was selected as the first predictor. When VO2max was added to V-OBLA as the second predictor the predictive accuracy increased significantly, but multiple R did not increase significantly by adding variables of walking economy or other parameters as independent variance. As a result, the combination of V-OBLA and VO2max as independent variables accounted for the greatest amount of total variance (97 per cent). It is suggested that blood lactate variable such as V-OBLA can account for a large portion of the variance in race pace on a 5 km walking performance.

Adult↗
PubMed1989

[Possible involvement of vascular endothelium-derived relaxing factor induced by platelet-activating factor (PAF) on human pulmonary artery after contraction in vitro].

We studied the effects of platelet-activating factor (PAF) on human pulmonary vascular smooth muscle in vitro. 10(-6) M PAF elicited slight contractions in 2 of 7 endothelium-denuded arterial strips, but did not elicit distinct contractions or relaxations in the other strips. After incubation with PAF at 10(-7) M, the contractions of pulmonary vascular smooth muscle induced by histamine and prostaglandin F2 alpha were significantly decreased. Preincubation of 10(-3) M indomethacin did not affect the inhibitory effects of PAF, but these disappeared with removal of endothelium. These results suggest that the inhibitory effects of PAF on human pulmonary vascular smooth muscle contractions may appear not through the cyclooxygenase products but the endothelium-derived relaxing factor.

Female↗