[Two-step tuberculin skin test in general hospital workers--comparison with nursing home workers].

In 1998, the Japanese Society for Tuberculosis recommended two-step tuberculin skin test (TST) for medical workers. As a large majority of the Japanese were BCG vaccinated in their childhood, it is difficult to distinguish true infection from booster effect. In Japan, it is important to record individual baseline tuberculin reactivity by two-step TST. Two-step TST was performed on 126 general hospital workers and 47 nursing home workers, excluding those whose initial TST was strongly positive, according to the recommendation of the Japanese Society for Tuberculosis in 1998 (strongly positive TST in Japan is defined as the reaction with other intensive responses such as double skin erythema, bleb, lymphangitis, etc.). Diameter of erythema of TST among hospital workers v.s. nursing home workers were as follows. In the initial TST: 23.2 +/- 16.7 mm v.s. 14.2 +/- 10.3 mm (p < 0.001), in the second TST: 26.3 +/- 17.1 mm v.s. 16.7 +/- 9.9 mm (p < 0.02), baseline of TST: 32.0 +/- 18.3 mm v.s. 19.4 +/- 10.7 mm (p < 0.001). Booster effect of TST in hospital workers was +9.8 +/- 15.1 mm, while it was +4.8 +/- 7.8 mm (not significant) in nursing home workers. Among those 30 years and over, these differences were no found, except diameter of erythema in the initial TST. In our hospital with no beds for TB, in the past 10 years, tuberculosis has not been broken out among our hospital workers, while several patients with pulmonary tuberculosis have been diagnosed every year (6 patients in 1999). Thus, some hospital workers might be exposed to infection with tuberculosis from these patients. On the other hands, no tuberculosis patients had been diagnosed in the nursing home, and young nursing home workers very rarely exposed to infection with tuberculosis in their life, and they are similar to the general population. This study suggested that hospital workers were more frequently exposed to tuberculosis infection than other workers.

Increased plasma level of platelet-activating factor (PAF) and decreased serum PAF acetylhydrolase (PAFAH) activity in adults with bronchial asthma.

We evaluated the plasma level of platelet-activating factor (PAF), a chemical mediator that induces various symptoms of bronchial asthma, and the activity of serum PAF acetylhydrolase (PAFAH), an enzyme that specifically inactivates PAF, in adults with bronchial asthma. Measurements were made by radioimmunoassay of samples obtained from 137 adult asthmatic patients (137 cases examined in remission and from among these 41 cases were also measured at the time of an asthmatic attack) 59 adult patients with untreated pulmonary tuberculosis and 106 healthy adult volunteers. It was demonstrated that the plasma PAF level was markedly higher and the serum PAFAH activity markedly lower in the asthmatic patients, both in remission and at the time of asthmatic attack, than in the healthy volunteers. The plasma PAF level was more closely associated with asthma both in remission and at the time of asthmatic attack than with pulmonary tuberculosis, whereas there was no significant difference in the serum PAFAH activity between the two diseases. The low serum PAFAH activity in the asthmatic patients may have been due to saturation as a result of continuous reaction to the increased plasma PAF level in those patients.

[Identification of Mycobacterium avium and Mycobacterium intracellulare using DNA probe test, and their ratio in Niigata area].

Using Gen-Probe test, both the Mycobacterium avium and Mycobacterium intracellulare strains were identified in the 76 disease-associated Mycobacterium-avium complex (MAC) strains isolated in the NIIGATA area. The following results were obtained: 1) Fifty-four MAC strains (71.1%) reacted with M. avium-probe and 22 strains (28.9%) reacted with M. intracellulare-probe. 2) There were no significant differences between the ratio of two strains before and after 1991. 3) The ratio of female cases with M. avium was significantly higher (22/32) in the later period (after 1991) than in the former period (9/22).

[Increased plasma levels of platelet-activating factor (PAF) and low serum PAF acetylhydrolase (PAFAH) activity in adult patients with bronchial asthma].

We studied the relationship between the blood levels of platelet-activating factor (PAF) and the activity of serum PAF acetylhydrolase (PAFAH), an enzyme that inactivates PAF, in adult patients with bronchial asthma. The PAF levels in the blood and the PAFAH activity in the serum obtained from adult patients with bronchial asthma in remission (137 cases) and from healthy adult controls (106 cases) were determined by radioimmunoassay (RIA) and compared. The following results were obtained. 1. The plasma levels of PAF were significantly higher in the patients with bronchial asthma in all severity groups (mild, moderate, and severe) and all asthma types (atopic, mixed, and infectious) than in the healthy controls (p < 0.001). However, no significant differences associated with the severity and type of asthma were noted. 2. Serum PAFAH activity was significantly lower in the patients with bronchial asthma in all severity groups (mild, moderate, and severe) and asthma types (atopic, mixed, and infectious) than in the healthy controls (p < 0.001). However, no significant differences associated with the severity and type of asthma were noted. 3. PAF/PAFAH in the patients with bronchial asthma showed no significant difference associated with the severity and type of asthma. 4. There was not a significant correlation between plasma levels of PAF and serum PAFAH activity in the patients with bronchial asthma. It was, therefore, suggested that the significantly high plasma PAF levels and the significantly low serum PAFAH activity in asthmatic adults compared to the respective values in healthy controls may explain one of the mechanisms of the development and persistency of adult bronchial asthma.

[The influence of serum theophylline concentration on the bronchodilating effect of salbutamol inhalation for bronchial asthma].

To examine the effects of serum theophylline concentration on the bronchodilating effect of beta 2-stimulant inhalated by patients with bronchial asthma, 200 micrograms-Salbutamol inhalation test was performed on 30 patients with bronchial asthma (from 17 to 71 years old, averaging 49.7; 3 mild, 15 moderate, 12 severe), who had taken theophylline at various oral doses up to 6 hours before the test. Measurements of respiratory function, serum theophylline concentration, blood pressure, pulse rate and the plasma c-AMP and c-GMP concentrations before and one hour after inhalation revealed that inhalation of 200 micrograms salbutamol significantly increased FVC, FEV1.0, PEF and plasma c-AMP (p less than 0.001). No significant change was noted in plasma c-GMP, diastolic pressure or pulse rate. Systolic pressure significantly decreased (p less than 0.05). Furthermore, no significant correlation was noted between the rates of increase (%) in FVC, FEV1.0 and PEF and those in plasma c-AMP, c-GMP and c-AMP/c-GMP in one hour after inhalation. Inaddlition no significant correlation was noted between the rates of increase in FVC, FEV1.0 and PEF one hour after inhalation and serum theophylline concentrations (0-19.3 and 0-21.5 micrograms/ml before and one hour after inhalation, respectively). The above results suggest that the bronchodilating effect of salbutamol inhalated at dose of 200 micrograms is not influenced by the serum theophylline concentration both before and at one hour after inhalation of salbutamol. The bronchodilating effect of salbutamol seems to be ascribable to an increase of intracellular c-AMP level of bronchial smooth muscle.

[ADH (anti-diuretic hormone), aldosterone (PA) and renin activity (PRA) in patients with respiratory failure].

Plasma ADH, PA and PRA in patients with respiratory failure (RF) were studied. RF patients were divided into 4 groups, i.e. acute RF (ARF) and chronic RF (CRF), with or without hypercapnia. The levels of these hormones were significantly higher in RF than those in control subjects, moreover, they were markedly elevated in ARF than those in CRF. In multiple regression analysis, ADH correlated with PaO2, pH and PRA in RF patients, but correlated with serum osmolality in control subjects. It was considered that ADH in RF was affected by the direct effect of blood gases and circulatory disorder. The mechanism of elevated PA and PRA in RF probably was mediated through restriction of intake of water and Na, reduction of renal blood flow and decreased ACE often occurred in RF. Abnormally elevated hormones are more often recognized in edematous patients than in nonedematous patients. It was suggested that many patients with RF develop heart failure or edema due to hormonal abnormalities.