Airway obstruction after acute ozone exposure in BALB/c mice using barometric plethysmography

BACKGROUND

Airway responsiveness after acute inhalation of ozone is related to the concentration and duration of ozone exposure. Using barometric whole-body plethysmography and increase in enhanced pause (Penh) as an index of airway obstruction, we measured the response of BALB/c mice to acute ozone inhalation to study the time course change of pulmonary function after ozone exposure.

METHODS

Penh was measured before and after exposure to filtered air or 0.12, 0.5, 1, or 2 ppm ozone for 3 hr (n = 6/group). In addition, Penh was measured 24, 48 and 72 hr after ozone exposure. Bronchoalveolar lavage (BAL) and histopathologic examinations were performed.

RESULTS

The increase in Penh after ozone exposure was significantly higher in the 0.12, 0.5, 1 and 2 ppm groups compared with the control group (all p < 0.01). Increases in Penh 24 hr after ozone exposure were significantly lower than those immediately after acute ozone exposure; however, increases in Penh 72 hr after ozone exposure were significantly higher than those in the control group (each p < 0.01). The proportion of neutrophils in BAL fluid was significantly higher in the group exposed to 2 ppm ozone than in the groups exposed to filtered air or 0.12 ppm ozone (both p < 0.01).

CONCLUSION

These results indicate that airway obstruction is induced following ozone exposure in a concentration-dependent manner and persists for at least 72 hr.

Oropharyngeal angioedema induced by inhaled histamine

Inhaled histamine used to measure airway responsiveness produces some side effects more frequently than does methacholine. It is possible that the inhaled histamine induces the side effects in asthmatics with increased end organ responsiveness to histamine. A 56-yr-old woman with chronic idiopathic angioedema presented with asthma-like symptoms. Methacholine challenge test was performed, with a negative result. Five days later, histamine inhalation test was done. FEV1 fell by 37% after inhalation of histamine concentration of 8 mg/mL. Immediately thereafter, severe angioedema on face, lips, and oropharyngeal area, foreign body sensation at throat, and hoarseness occurred. To assess end organ responsiveness to histamine, skin prick tests with doubling concentrations of histamine (0.03-16 mg/mL) were carried out on the forearm of the patient and six age- and sex-matched asthmatic controls. The wheal areas were measured. The patient showed greater skin responses than the controls. Regression analysis showed that the intercept and slope were greater than cut-off levels determined from six controls. The patient showed an increased skin wheal response to histamine, indicating the enhanced end organ responsiveness to histamine, which is likely to contribute to the development of the oropharyngeal angioedema by inhaled histamine.

Relationship between nasal and bronchial responsiveness in perennial allergic rhinitic patients with asthma

BACKGROUND

The nasal and bronchial mucosa present similarities and most patients with asthma also have rhinitis, suggesting the concept of 'one airway one disease'. Although many studies may suggest the relationship between nasal and bronchial responsiveness in patients with allergic rhinitis and asthma, few studies have been published which address this question directly. The aim of this study is to investigate whether the relationship between nonspecific nasal and bronchial responsiveness exists in perennial allergic rhinitic patients with asthma.

METHODS

Fifty-one perennial allergic rhinitic patients with the definitive or suspected asthma underwent methacholine bronchial provocation tests and nasal histamine challenge tests. A slope of the absolute changes in nasal symptoms score/log concentrations of histamine was calculated by linear regression analysis. A ratio of the final absolute change in nasal symptoms score to the sum of all the doses of histamine given to the subject was also calculated. The degree of bronchial responsiveness to methacholine was categorized as positive bronchial hyperresponsiveness (BHR) if PC(20) (provocative concentration of methacholine resulting in 20% fall in FEV(1)) was <4 mg/ml, borderline BHR if PC(20) was >or=4 but <or=16 mg/ml, and negative BHR if PC(20) was >16 mg/ml. Another index of bronchial responsiveness (BRindex) was calculated as the log [(% decline in FEV(1)/log final methacholine concentration as mg/dl) + 10].

RESULTS

The geometric means of the slope (4.47 vs. 2.95, p < 0.05) and the ratio (1.68 vs. 0.54, p < 0.01) were higher in patients with positive BHR (n = 23) than in patients with negative BHR (n = 19), respectively. The geometric means of the slope (3.50) and the ratio (1.13) in patients with borderline BHR (n = 9) were between the two groups, respectively. In all patients, the log-slope (r = 0.48, p < 0.001) and the log-ratio (r = 0.51, p < 0.001) were correlated well with the BRindex, respectively. Even in allergic rhinitic patients with definitive asthma, the log-slope was correlated with the BRindex (r = 0.39, p < 0.05) or log-PC(20) (r = -0.36, p < 0.05).

CONCLUSIONS

The nonspecific nasal responsiveness may be related to the nonspecific bronchial responsiveness in patients with allergic rhinitis and asthma, which may support the viewpoint that allergic rhinitis and asthma represent a continuum of inflammation involving one common airway.

Relationship between changes in interferon-gamma production by peripheral blood T cells and changes in peak expiratory flow rate in patients with chronic stable asthma

BACKGROUND

Cytokines production by T helper lymphocytes (Th cells), which orchestrate the interplay of the different cells involved in airway inflammation of asthma, may be reflected in peripheral blood. Some studies have suggested that the Th cell cytokines by peripheral blood T cells correlate with asthma severity.

OBJECTIVE

To investigate the relationship between changes in IFN-gamma production by peripheral blood T cells and changes in lung function in chronic stable asthmatics.

METHODS

Sixteen patients with chronic stable moderate asthma aged 35-65 years (nine women) were recruited. Morning and evening peak expiratory flow rates (PEFR) monitoring and blood sampling for peripheral blood T cell culture, total IgE and blood eosinophils were performed at baseline and week 12. Levels of IFN-gamma, IL-4 and IL-5 in culture supernatants of peripheral blood T cell were determined by using enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

Patients with increased IFN-gamma changes from baseline showed significantly increased changes in morning (P = 0.02) and evening (P < 0.05) PEFR compared with those with decreased IFN-gamma changes. The changes in IFN-gamma production and IFN-gamma: IL-4 ratio significantly correlated with the changes in morning PEFR (Rs = 0.59, P < 0.02; Rs = 0.63, P < 0.01, respectively) and tended to correlate with the changes in evening PEFR (Rs = 0.45, P = 0.08; Rs = 0.5, P = 0.05, respectively). The changes in IL-4 and IL-5 did not correlate with the changes in IgE and blood eosinophils, respectively.

CONCLUSIONS

These findings suggest that IFN-gamma may be associated with the alteration of lung function in asthmatics and play a role in the pathophysiology of chronic stable asthma.

Peak expiratory flow rate underestimates severity of airflow obstruction in acute asthma

BACKGROUND

Several investigators have demonstrated a considerable disagreement between FEV1 and PEFR to assess the severity of airflow obstruction. The purpose of this study was to examine whether the discrepancy between the two measurements affects the assessment in the severity of acute asthma.

METHODS

Thirty-five consecutive asthma patients measured both FEV1 and PEFR at 0, 1hr, 1, 3, 5, 7 days of an emergency room admission using a spirometer and a Ferraris PEFR meter. The degree of discrepancy between FEV1 and PEFR expressed as % predicted values was determined.

RESULTS

When predictive equations that recommended by the instrument manufacturers were used. PEFR measured with the PEFR meter (f-PEFR) was significantly higher than FEV1 at all time points, with 16.1% mean difference and unacceptable wide limits of agreement (-20.0-52.3%). The classification in severity was significantly different between FEV1 and f-PEFR (p < 0.001). The discrepancy was inter-instrumental in large part because f-PEFR was 10.1% higher than spirometric PEFR. Different predictive equations altered the degree of the differences but could not completely correct it.

CONCLUSION

These results indicate that f-PEFR values underestimate the severity of airflow obstruction in acute asthma despite using recommended predictive equations. Therefore, these confounding factors should be considered when the severity of airflow obstruction is assessed with PEFR.

Therapeutic effects of BCG vaccination in adult asthmatic patients: a randomized, controlled trial

BACKGROUND

Bacille Calmette-Guérin (BCG) vaccination in humans induces Th1 immune responses. Th1 and Th2 cells are reciprocally regulated.

OBJECTIVE

To examine whether BCG vaccination of adult patients with asthma, a Th2-associated allergic disease, is clinically effective.

METHODS

Forty-three moderate-to-severe asthma patients were randomly assigned into groups that received percutaneous injection of 58.2 x 10(7) CFUs BCG (n = 22) or placebo (n = 21) in a double-blinded fashion, on the first day of a 12-week treatment period. Medications were adjusted every 4 weeks to maintain optimal asthma control. Spirometric measurements were performed before treatment and at weeks 4, 8, and 12 after vaccination. The daily peak expiratory flow rate values, asthma symptoms, and medications were also recorded. Tuberculin skin tests, and sputum inflammatory cell and cytokine analyses were carried out before treatment and 12 weeks after vaccination.

RESULTS

BCG vaccination significantly increased forced expiratory volume in 1 second and forced expiratory flow rate 25% to 75% at weeks 4, 8, and 12. Morning peak expiratory flow rate was significantly increased only during the first 4 weeks. Although the asthma symptom scores were not significantly changed, the weekly medication scores were significantly decreased. Tuberculin skin reactivities were significantly increased without significant alterations in induced sputum profiles. In contrast, medication scores and sputum eosinophils were significantly increased, and the interferon-gamma:interleukin-4 ratio in sputum was significantly decreased in the placebo group.

CONCLUSIONS

BCG vaccination improved lung function and reduced medication use in adults with moderate-to-severe asthma. This amelioration was accompanied by a suppressed Th2-type immune response, suggesting that BCG vaccination might be an effective therapeutic modality against asthma.

Steroid-induced delirium in a patient with asthma: report of one case

Systemic steroids are highly effective for patients with moderate-to-severe asthma exacerbations. Steroid-induced psychosis is known to be one of the adverse effects of steroid therapy, although infrequent. However, there is no reliable method of predicting steroid psychosis. We experienced the case of a 40-year-old asthmatic man who had previously taken steroids without any psychological side effect, but became acutely delirious after receiving some doses of steroids, higher than the previous doses, under a condition of emotional stress. The mean dose of prednisolone administered was 82 mg/day (1.37 mg/kg/day) for 10 days but the patient had taken two courses of steroids (0.82 mg/kg/day and 0.5 mg/kg/day, respectively) for asthma exacerbations without any psychiatric episodes during the previous year. At this time, the patient was under a condition of emotional stress related to family reasons. The asthmatic exacerbation of this case may be precipitated from sudden emotional stress and the following treatment with a high dose of steroida should be used cautiously due to the possibility of psychotic side reactions.

Lactic acidosis associated with the usual theophylline dose in a patient with asthma

Metabolic and electrolyte abnormalities, including hypokalemia, hyperglycemia and lactic acidosis, are associated with theophylline overdose. However, we report an unusual case of sinus tachycardia, lactic acidosis, hypokalemia and hyperglycemia associated with the usual theophylline dose in a patient with asthma. The theophylline dose was 200 mg orally twice daily. Three hours after administration of the third dose, the patient experienced palpitation. An electrocardiogram showed a sinus tachycardia. Arterial blood gas analysis revealed a mixed metabolic acidosis and respiratory alkalosis. Serum lactate level was 51 mmol/L (normal 0.7-2.1 mmol/L). Biochemistry results were sodium 136 mEq/L, chloride 99 mEq/L, potassium 1.9 mEq/L and glucose 204 mg/dL. Our case suggests that a possibility of theophylline-associated metabolic abnormalities should be considered when an asthmatic patient given the usual theophylline dose presents with lactic acidosis, hypokalemia and hyperglycemia of unknown etiology.

Atopy may be related to exercise-induced bronchospasm in asthma

BACKGROUND

Recent studies suggest that atopy may be associated with exercise-induced bronchospasm (EIB) in asthma. However, it is not clear whether atopy is related to EIB, regardless of airway hyper-responsiveness (AHR) to methacholine, because asthmatic subjects often show AHR to exercise and methacholine simultaneously.

OBJECTIVE

To investigate whether atopy is related to EIB in asthmatic subjects, independently of AHR to methacholine.

METHODS

Fifty-eight male asthmatic subjects were studied. Initial spirometry was performed. Skin prick test was carried out, using 53 common allergens including mites dust antigen. Atopy score was defined as a sum of mean weal diameters to all allergens tested. Methacholine bronchial provocation testing was performed. Twenty-four hours later, free running test was performed. Positive EIB was defined as a 15% reduction or more in FEV1 from baseline after exercise.

RESULTS

All subjects had AHR to methacholine. The degree of AHR to methacholine in asthmatics with EIB was similar to that in asthmatics without EIB. However, atopy score and skin reaction to Dermatophagoides pteronyssinus significantly increased in asthmatics with EIB compared with those without EIB (P < 0.05, respectively). Furthermore, the degree of EIB significantly correlated with atopy score in all subjects (r = 0.35, P < 0.01). This relationship was maintained even after the exclusion of EIB-negative asthmatic subjects.

CONCLUSION

Atopy defined as skin test reactivity may contribute to the development of EIB in asthma, independently of AHR to methacholine.

Seasonal difference in the occurrence of exercise-induced bronchospasm in asthmatics: dependence on humidity

BACKGROUND

Most studies on the effects of temperature and humidity on exercise-induced bronchospasm (EIB) in asthmatics have been carried out under indoor conditions. However, any asthmatic patient is exposed to varying climatic conditions.

OBJECTIVE

To investigate whether temperature or relative humidity plays a more important role in determining the degree of EIB in asthmatics under naturally exposed climate conditions.

METHODS

To exclude the effects of pollen on EIB, we enrolled 69 subjects with perennial asthma (mean +/- SD: 20.1 +/- 1.5 years). The subjects performed outdoor free running tests. They were divided into winter (n = 25), spring/autumn (n = 22), and summer (n = 22) groups according to the season when they performed the tests. Initial spirometry and skin prick tests were performed. Methacholine bronchial challenge testing and, one day later, the free running tests were done.

RESULTS

There were significant differences in temperature and relative humidity among the three groups: However, the relative humidity in winter did not differ from that in spring/autumn. There were no differences in pulmonary functions, airway responsiveness, and atopy score among the three groups. The percentage of cases of positive EIB --fall in forced expiratory volume in 1s FEV(1) of >15% from baseline --in winter (84%, p < 0.05) or spring/autumn (86.4%, p < 0.05) was higher than that in summer (50%). However, the percentage of subjects with a positive EIB in winter did not differ from that in spring/autumn. The maximal percent fall in FEV(1) after exercise in winter did not differ from that in spring/autumn.

CONCLUSIONS

The occurrence of EIB is associated with environmental temperature and humidity. Under such climatic conditions as in Korea, relative humidity may be a more important factor than temperature in contributing to EIB in patients with perennial asthma.

Relationship between the perception of dyspnoea and airway inflammatory markers

Poor dyspnoea perception in asthmatic patients seems to be associated with increased risk of asthma exacerbation. We have studied the relationship between basel ne dyspnoea perception and inflammatory markers in sputum in eight patients with mild asthma and in 13 patients with moderate to severe asthma. The perception of dyspnoea was scored on the Borg scale. Eosinophilic cationic protein (ECP) was measured by fluoroimmunoassay and by an interleukin (IL)-5 sandwich ELISA. The baseline Borg score was significantly higher in patients with severe asthma than in patients with mild to moderate asthma (4.1 +/- 0.29 vs. 2.28 +/- 0.28, P<0.05). The proportion of eosinophil and ECP levels in the sputum were significantly higher in patients with moderate to severe asthma. IL-5 in sputum was significantly increased in moderate to severe asthmatic patients compared to mild asthmatic patients. A significant relationship was found between the baseline perception score and FEV1/FVC (r = -0.53, P<0.01), sputum eosinophils (r = 0.70, P<0.01) and sputum ECP (r = 0.62, P<0.01). These findings suggest that the baseline perception score is related to inflammatory markers in sputum, and that the perception of dyspnoea as well as airway inflammatory markers may be considered to evaluate asthma severity.

Chicken interferon type I inhibits infectious bronchitis virus replication and associated respiratory illness

Infectious bronchitis virus (IBV) causes an economically important respiratory disease in poultry worldwide. Previous studies have shown that CD8(+) cytotoxic T lymphocytes (CTL) are critical in controlling acute IBV infection, but the role of innate immunity is unknown. This study describes the in vitro and in vivo anti-IBV activity of natural spleen cell-derived and recombinant chicken interferon type I (rChIFN-alpha). Both natural and rChIFN-alpha inhibited replication of the Beaudette strain of IBV in chicken kidney cells (CKC) in a dose-dependent manner, with the antiviral activity of the former accounted for entirely by its content of type I IFN. IFN at 100 U/ml reduced viral replication by 50% as measured by syncytia formation. In addition, the spleen cell-derived supernatants (natural IFN) inhibited tracheal ring ciliostasis mediated by the Gray strain of IBV. Optimal protection against IBV-induced respiratory disease was obtained after intravenous or oral administration of ChIFN given 1 day before virus challenge and each of 5 days thereafter. ChIFN-I protected chicks from clinical illness by delaying the onset of the disease and decreasing the severity of illness, demonstrating its potential as an immune enhancer.

Modulatory effects of ionized alkali mineral complex (IAMC) on mRNA expression of porcine cytokines

It has been recognized that ionized alkali mineral complex (IAMC)-fed farm animals demonstrate higher weight gains but less incidence of diseases than the unfed ones. However, how these beneficial effects in the IAMC-fed animals are induced has not yet been elucidated clearly. In this study, porcine peripheral blood mononuclear cells (PBMC) were cultured for 4, 24, and 48 hr in the presence of IAMC, and the effects of IAMC on mRNA expression of porcine cytokines were evaluated via a reverse transcription-polymerase chain reaction (RT-PCR). Expression levels of IL-4, IL-6, and IL-10 in IAMC-treated cells were usually higher than those in the untreated ones. However, IAMC-treated cells demonstrated a reduced expression of IL-2. In addition, expression of IFN-gamma was generally reduced in the cells treated with IAMC. The expression of IL-12 p35 and IL-12 p40 was not detectable in both the untreated and the IAMC-treated cells. Therefore, these results indicate that IAMC has immunomodulatory effects in vitro on the expression of porcine Th1-and Th2-type cytokines.

Desensitization to urine-derived gonadotropins in a woman with secondary infertility

BACKGROUND

Urine-derived gonadotropins have been used to treat infertility but may cause allergic reactions. IgE-mediated hypersensitivity reactions can be treated with desensitization, especially when new therapies such as recombinant human gonadotropins are unavailable.

OBJECTIVE

This case is described to highlight a successful intervention with desensitization in a woman with a complicated history of secondary infertility. She had been treated with ovulation-induction regimens, such as IVF-M (in vitro fertilization-human menopausal gonadotropin [hMG]) and IVF-C (human chorionic gonadotropin [hCG]), for intrauterine insemination. During treatment, however, she experienced reactions to IVF-M and IVF-C. Because she strongly wanted a baby and no alternative preparation was available, desensitization was attempted.

METHODS

Intradermal tests with IVF-M and IVF-C using both negative and positive controls were performed on the patient and four normal control subjects. Immediate wheal-and-flare reactions occurred only in the patient. ELISA and ELISA inhibition tests showed positive responses to IVF-M and IVF-C, but not to highly purified hMG, hCG, or D-mannitol, a preservative in IVF-M and IVF-C. Desensitization to IVF-M and IVF-C was done with a protocol used for parenteral desensitization to penicillin.

RESULTS

During the IVF-M desensitization, the intramuscular injections were well tolerated. For the next 2 days, daily administration of IVF-M was uneventful. Thirty-six hours later, desensitization to IVF-C was performed successfully. The patient had two intrauterine inseminations and became pregnant.

CONCLUSIONS

Nongonadotropin proteins in urine-derived gonadotropins cause IgE-mediated hypersensitivity reactions. Acute desensitization to urine-derived gonadotropins can be performed effectively, as shown in our current case.

Effects of BCG infection on Schultz-Dale reaction, allergen-specific IgE levels, and Th2 immune response in sensitized rats

BACKGROUND

BCG, a potent inducer of Th1 immune response, has been suggested to suppress Th2 response which is known to mediate IgE-mediated allergic disorders, in particular allergic asthma. Schultz-Dale reaction is known to be a model of IgE-mediated hypersensitivity. This study was done to investigate whether BCG infection suppresses the Schultz-Dale reaction by inhibiting Th2 response and allergen-specific IgE production.

METHODS

Twenty-four Sprague-Dawley rats were sensitized and provoked with ovalbumin (OVA). A pretreatment of 6 x 10(4) colony forming units of BCG or saline was done 7 days before sensitization. The Schultz-Dale reaction was represented as tracheal smooth muscle contractions to 50 micrograms/mL OVA challenge in vitro. Serum OVA-specific IgE levels and IFN-gamma and IL-4 concentrations in bronchoalveolar lavage fluid (BALF) were measured.

RESULTS

The Schultz-Dale reaction and serum OVA-specific IgE levels were significantly decreased in BCG infected and OVA sensitized rats compared with only sensitized rats (p < 0.01 and p < 0.05, respectively). As compared with only sensitized rats, IL-4 concentration and a ratio of IFN-gamma:IL-4 in BCG infected and OVA sensitized rats were significantly decreased (p < 0.001) and increased (p < 0.05), respectively. The Schultz-Dale reaction was correlated with OVA-specific IgE levels (r = 0.50, p < 0.05), IL-4 concentration (r = 0.69, p < 0.001), and ratio of IFN-:IL-4 (r = -0.44, p < 0.05). OVA-specific IgE levels were correlated with IL-4 concentration (r = 0.61, p < 0.01) and ratio of IFN-gamma:IL-4 (r = -0.48, p < 0.05).

CONCLUSION

These findings suggest that BCG infection prior to allergen sensitization may inhibit Schultz-Dale reaction developed in the sensitized rat tracheal smooth muscle via the suppressive effects of Th2 immune response and allergen-specific IgE production.

Relationship between sputum inflammatory markers and osmotic airway hyperresponsiveness during induction of sputum in asthmatic patients

Hypertonic saline aerosols are being used increasingly for bronchial provocation testing and induction of sputum. The aims of this study were to assess the response to challenge with 3% hypertonic saline administered via a ultrasonic nebulizer in patients with asthma, and to evaluate relationship between % fall of FEV1 during induction of sputum (osmotic airway hyperresponsiveness; osmotic AHR) and biochemical markers of induced sputum. We investigated changes in FEV1 in response to inhaling ultrasonically nebulized 3% saline in 25 patients with asthma and 10 control subjects. FEV1 was measured before, during, and after induction of sputum. We used fluoroimmunoassay to detect eosinophil cationic protein (ECP), immunohistochemical staining to detect EG2+ (secretory form of ECP) eosinophils, and a sandwich ELISA to detect interleukin (IL)-5. Protein concentration was determined by using bicinchoninic acid protein assay reagent. Asthmatics, compared with controls, had significantly higher osmotic AHR. Moderate to severe asthmatics had significantly higher osmotic AHR compared to mild asthmatics. Osmotic AHR was significantly correlated with the proportion of eosinophils, the levels of ECP, EG2+ eosinophils, IL-5, and proteins. These data suggest that osmotic AHR is closely related to the clinical status and biochemical markers of sputum supernatant in asthmatic patients.

Non-lipid effects of statin on hypercholesterolemic patients established to have coronary artery disease who remained hypercholesterolemic while eating a step-II diet

BACKGROUND

Results of clinical trials of statin therapy demonstrate that an improvement in incidence of cardiovascular end points and coronary stenosis can be achieved. The beneficial effects of statins on clinical events may involve nonlipid mechanisms that affect endothelial function, such as inflammatory responses, formation of thrombi, and stabilization of plaque.

OBJECTIVE

To investigate levels of serologic markers, which may be useful surrogates for activity of vascular disease after administration of statin.

METHODS

We administered 20-40 mg simvastatin daily for 14 weeks to 13 patients established to have coronary artery disease who remained hypercholesterolemic during step-II diet therapy.

RESULTS

Administration of simvastatin significantly lowered lipoprotein levels and the low: high-density lipoprotein cholesterol level ratio and apolipoprotein B:A-I level ratio compared with pretreatment values (P < 0.01). Administration of simvastatin significantly lowered plasma levels of matrix metalloproteinase-9 (MMP-9) and monocyte chemoattractant protein-I [33+/-46 and 13+/-19%, respectively (P = 0.027 and 0.020, respectively)]. Furthermore, administration of simvastatin tended to lower plasma levels of plasminogen activator inhibitor type-1 and tumor necrosis factor-alpha [by 20+/-44 and 13+/-29%, respectively (P= 0.066 and 0.110, respectively)]. There were significant inverse correlations between pretreatment levels of MMP-9 and the degree of change in those levels after administration of simvastatin (r = -0.714, P= 0.005). However, there was no significant correlation between levels of lipoprotein and levels of MMP-9, monocyte chemoattractant protein-I, and plasminogen activator inhibitor type-1 during administration of simvastatin.

CONCLUSIONS

Our current data support the hypothesis that nonlipid mechanisms elicited by administration of simvastatin contribute to the decrease in incidence of cardiovascular events and explain the early clinical benefit observed in clinical trials, independent of changes in levels of lipoprotein.

Airway responsiveness as a direct factor contributing to the dyspnoea perception in asthma

It is not clear whether airway responsiveness is directly related to the perception of bronchoconstriction in asthma. The purpose of this study is to directly compare the perception of induced bronchoconstriction among the groups classified according to the degree of airway responsiveness. Two hundred and twenty-seven patients with the definitive or suspected asthma underwent a methacholine provocation test. During the test, the degree of dyspnoea was assessed by a modified Borg scale. The perception of induced bronchoconstriction was indicated by the slope in the linear regression analysis between changes in Borg score and the reduction in forced expiratory volume in 1 sec (FEV1) as a percentage of baseline value. The provocative concentration of methacholine resulting in 20% fall in FEV1 (PC20) was calculated. The degree of airway responsiveness to methacholine was categorized as moderate to severe airway hyper-responsiveness (AHR) if PC20 was < 1 mgml(-1), mild AHR if PC20 was > or =1 but < or =4 mgml(-1), borderline AHR if PC20 was >4 but < or =16 mgml(-1), and normal airway responsiveness (negative AHR) if PC20 was > 16 mgml(-1). Positive AHR was defined as PC20< or =4 mgml(-1). Another index of bronchial responsiveness (BR index) was calculated as the log [(% decline in FEV1/log final methacholine concentration as mg dl(-1)+10]. We found that the geometric mean of the slope was lower in subjects with positive AHR (0.12, n=115) than in subjects with negative AHR (0.17, n=72; P<0.01). The geometric mean of the slope in subjects with borderline AHR (0.14, n=40) was between the two groups. Furthermore, the slope was decreased in asthmatics with moderate to severe AHR compared with mild AHR (P <0.05), although the baseline FEV1 did not differ between the two groups. In multiple regression analysis, airway responsiveness expressed as BR index had a significant effect on the perception of bronchoconstriction. We conclude that the perception of bronchoconstriction is diminished in patients with AHR and the degree of airway responsiveness may be directly related to the perception of bronchoconstriction in asthmatic subjects.