Biomedical subjects

Naoko Tojo

Publications and source records attributed to Naoko Tojo.

8 recordsLinked to original sources

PubMed2006

[Problems of lung function testing in the laboratory].

Spirometry is indispensable for the screening test of general respiratory function, and measurements of lung volume and diffusing capacity play an important role in the assessment of disease severity, functional disability, disease activity and response to treatment. Pulmonary function testing requires cooperation between the subjects and the examiner, and the results obtained depend on technical as well as personal factors. In order to diminish the variability of results and improve measurement accuracy, the Japan Respiratory Society published the first guidelines on the standardization of spirometry and diffusing capacity for both technical and clinical staff in 2004. It is therefore essential to distribute the guidelines to both laboratory personnel and general physicians. Furthermore, training workshops are mandatory to improve their understanding of the basics of lung function testing. Recently, there has been increasing interest in noninvasive methods of lung function testing without requiring the patient's cooperation during spontaneous breathing. Three alternative techniques, i.e. the negative expiratory pressure (NEP) method to detect expiratory flow limitation, impulse oscillation system (IOS) to measure respiratory system resistance (Rrs) and reactance (Xrs), and interruption resistance (Rint) to measure respiratory resistance have been introduced. Further study is required to determine the advantage of these methods.

Airway Resistance↗

PubMed2005

Pulmonary exercise testing predicts prognosis in patients with chronic obstructive pulmonary disease.

OBJECTIVE: In patients with chronic obstructive pulmonary disease (COPD), patient age and initial value of forced expiratory volume in 1 second (FEV1) have been considered the most accurate predictors of mortality among the parameters obtained from pulmonary exercise tests. However, few studies have examined the predictive variables of prognosis among exercise parameters in COPD. We therefore attempted to identify the best index for predicting long-term survival in patients with COPD among the cardiopulmonary variables obtained during exercise testing. PATIENTS AND METHODS: Fifty-eight patients with COPD (50 men and 8 women) without hypoxemia at rest or other serious complications performed resting pulmonary function tests followed by a symptom-limited ramp exercise test on a cycle ergometer with breath-by-breath gas analysis and arterial blood gas sampling. RESULTS: After 3,570+/-1,373 days follow-up (mean+/-SD), 21 died because of deaths by respiratory failure. The overall survival rates calculated by the Kaplan-Meier method were 92.9% and 75.8% at 5 years and 10 years, respectively. In univariate Cox hazards analysis, age, FEV1, VC, RV/TLC, VEmax, VO2max, VCO2max, PaO2max, PacO2max, and PaO2 at rest were found to be significant prognostic indices of survival. However, multivariate analysis revealed only FEV1, PaO2max, and age as independent predictors of mortality. In severe COPD patients (FEV1 <50% predicted, n=35), PaO2max and age also correlated with prognosis, whereas FEV1 did not. CONCLUSION: Pulmonary exercise testing is useful in predicting prognosis in patients with COPD.

Aged↗

PubMed2005

[Lung function testing --the Official Guideline of the Japanese Respiratory Society].

This review article introduces the official guideline for the lung function testing firstly established by the Japanese Respiratory Society in November 2004. The members of the Japanese Society of Laboratory Medicine were also included in the working group to make the guideline. A central goal of the guideline is to standardize the skill of lung function testing and thus minimize its variability. The guideline includes the chapters for spirometry, flow-volume curve, and diffusing capacity of the lung, where principles and quality controls are introduced with reference values for each testing. Furthermore, the algorithm for differential diagnosis using the lung function testing is demonstrated in the last chapter. The lung function testing can bring a strong impact on patients' lifestyle and future treatment plan. We sincerely hope that this guideline will contribute to routine laboratory practice.

Humans↗

PubMed2004

[The rate of airflow limitation among the elderly undergoing spirometry in a university hospital].

The aim of this study was to examine the rate of airflow limitation among the elderly undergoing spirometry prior to surgical operation, and to evaluate whether or not spirometry is useful for the early detection of COPD. A total of 3,086 patients (1,717 men and 1,369 women) ranging in age from 40 to 93 underwent screening spirometry from January to December 2003 in Tokyo Medical and Dental University Hospital. Among the total population, 2,135 patients (1,188 men and 947 women) were ordered to undergo the spirometry prior to surgical operation, airflow limitation (FEV1/FVC < 70%) was observed in 19.5% (n=417) of the cases and was considerably more frequent in men than in women(27.0%[n=321] vs. 10.1%[n=96]). The rate of FEV1/FVC < 70% in those 2,135 patients increased with age: 6.2%, 9.9%, 19.2%, 32.5% and 34.1% of patients in their 40s, 50s, 60s, 70s, 80s and over, respectively. Among the patients with airflow limitation, 35% of the cases revealed FEV1 > or = 80% predicted; 50%, 50 < or = FEV1 < 80% predicted; 14%, 30 < or = FEV1 < 50% predicted; 1%, FEV1 < 30% predicted. Patients with mild to moderate airflow limitation rarely consulted the pulmonary medicine department. The prevalence of airflow limitation was more frequent among in- and out-patients than in the random sample population. Spirometry prior to surgical operation is useful for the early detection of COPD and these data could be an important source for medical staff seeking a definitive diagnosis of patients revealing airflow limitation.

Adult↗

PubMed2003

The effect of seratrodast on eosinophil cationic protein and symptoms in asthmatics.

Thromboxane A2 (TXA2), an arachidonate derivative, is a potent bronchoconstrictor; therefore, blocking TXA2 should attenuate airway narrowing. Seratrodast, a TXA2 receptor antagonist, is expected to be a potent antiasthmatic. It was reported that seratrodast reduced bronchial hyperresponsiveness. However, it is controversial whether it reduces airway inflammation. We studied some additional effects of oral seratrodast to inhaled corticosteroids on 10 adult asthmatics in an open-label, crossover design study. Eosinophil cationic protein (ECP) levels in serum and sputum, peak expiratory flow rate (PEF), clinical symptoms, and airway responsiveness were evaluated. Clinical symptom scores were improved by administration of seratrodast (p < 0.05). The addition of seratrodast to asthmatic patients significantly improved mean PEF (p < 0.05). In addition, withdrawal of seratrodast resulted in deterioration of PEF. Airway hyperresponsiveness to acetylcholine measured by Astograph was improved by administration of seratrodast (p < 0.01), and returned to the level of "run-in period" after withdrawal. Administration of seratrodast decreased the concentration of ECP in sputum significantly (p < 0.05), and sputum ECP significantly increased again after withdrawal of (p < 0.05). These results suggest that seratrodast improves clinical symptoms andairway hyperresponsiveness by reducing airway inflammation. Seratrodast may be useful as an anti-inflammatory agent and beneficial when added to inhaled corticosteroids in the treatment of bronchial asthma.

Adult↗

PubMed2003

[Management of laboratory for clinical physiology].

Physiological examination has the following characteristics: 1. Patient understanding and cooperation are required. 2. Accuracy of the results of examination is influenced by technician skill and experience. 3. Accidents may occur during examination. 4. Examination and judgment of the results proceed under cooperation between doctors and technicians. 5. Examination can be performed at patient's bedside. Recently, laboratories for clinical physiology have been required to provide high-quality examinations with an efficient cost-performance. They must not only integrate and conduct various physiological tests on demand, but also arrange the proper number of staff for the proper number of instruments. It is important to reinforce the risk management against unexpected accidents and to allocate a chief technician for flexible management of the laboratory. Equipment should be purchased according to systematic planning, novel technology should be actively introduced into laboratory medicine, and excellent technicians to handle it should be brought up. Standardization of the test methods and the quality control are necessary to guarantee the quality of the test results. These are issues to be solved by the society of laboratory medicine and not by a single institution.

Clinical Laboratory Techniques↗

PubMed2003

[GOLD guideline and recommendation for role of spirometry in COPD].

COPD is currently the fourth leading cause of death in the world, and further increase in its prevalence and mortality have been predicted for the coming decades. To decrease the morbidity and mortality due to COPD, better recognition of the risk of COPD and improvement in prevention and management of COPD is required. Many national and international societies of respiratory diseases have developed guidelines for COPD. In the GOLD report, COPD is a disease status characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. Airflow limitation in COPD is best measured through spirometry, which is a key to the diagnosis and management of the disease. It is the most standardized, reproducible, and objective measurement of airflow limitation available. A decrease in the ratio of FEV1 to FVC is often the first sign of developing airflow limitation. In Japan, a major problem is the lack of guidelines for standardization of spirometry. To achieve consistently accurate test results, not only standardization of spirometry but also propagation of proper procedure and evaluation of spirometry are required.

Humans↗

PubMed2002

Effect of chest wall vibration on dyspnea during exercise in chronic obstructive pulmonary disease.

To elucidate the effect of in-phase chest wall vibration (IPV) during exercise, 17 COPD male patients performed two constant-load exercise tests on a cycle ergometer with and without IPV. The Borg dyspnea score significantly decreased from IPV (-) to IPV (+) (from 13.6+/-2.9 to 12.5+/-2.9, P<0.01). IPV elicited a significant increase in V(O(2)) (P<0.005) and significant decreases in both VE/V(O(2)) (P<0.05) and respiratory frequency (P<0.05), but it did not elicit any changes in VE. The change in Borg score between IPV (+) and IPV (-) showed a significant positive correlation with % predicted V(O(2),max) (r=0.71) and FEV(1)/FVC (r=0.69). Patients in the responsive group (n=11) showed significantly lower FEV(1) (P<0.05) and higher DeltaN(2)/L (P<0.01) than patients in the non-responsive group (n=6). We conclude that IPV reduces dyspnea and improves respiratory efficiency during aerobic exercise in severe COPD.

Aged↗