Pretreatment REM sleep and subjective sleep quality distinguish depressed psychotherapy remitters and nonremitters

BACKGROUND

We compared pretreatment subjective and electroencephalographic sleep measures among depressed patients who remitted with psychotherapy alone and those who did not remit.

METHODS

Patients were 111 midlife women with recurrent major depressive disorder. Baseline psychiatric ratings and sleep studies were conducted prior to treatment with weekly interpersonal psychotherapy. Remission was defined as a score of < or = 7 for 3 consecutive weeks on the Hamilton Depression Rating Scale. Clinical and sleep measures were compared between remitters (n = 62) and nonremitters (n = 49) using t tests and random regression. Linear discriminant function analyses were used to categorize remitters and nonremitters on the basis of sleep measures.

RESULTS

Treatment nonremitters had significantly worse subjective sleep quality and significantly elevated phasic REM sleep as measured by multivariate and univariate analyses. The linear accumulation of REM activity during sleep occurred at a significantly higher rate in nonremitters than in remitters. Linear discriminant function analyses based on subjective sleep quality and REM activity correctly identified 68.3% of nonremitters and 68.5% of remitters.

CONCLUSIONS

These findings highlight the role of subjective and REM sleep measures as correlates of short-term psychotherapy treatment response in major depressive disorder. Disturbed sleep may be a physiological indicator of increased limbic and brain stem arousal.

[Evaluation of the incidence of clinical symptoms and risk factors for COPD based on the monitoring of refinery workers in Piock (1993-1996)]

Work place environment plays an important role in development diseases because of the time spend in and different toxic factors placed in it. The aim of study was to assess the ventilatory efficiency in individuals employed in Generating Plant (GP) in relation to the pollution of the work place and the tobacco smoking habit during 3 years. The study covered a group of 144 male individuals employed at GP. (age 39.3 +/- 8.7 yrs, period of employment 20.3 +/- 8.6 yrs, smokers 53.5%. Lung function tests consisted of VC, FVC, FEV1, FEV1%VC, PEF, FEF50 counted from flow-volume curve and TGV, Rt measured using pletysmographic method. All tests were performed using pletysmograph (Masterlab) "Jaeger" placed on the ambulance near to the work place. The measurements were taken in May 1993 and 1996. Results were compared to with normal values (acc. ECSC). The anamnesis was obtained from all workers in the form of questionnaire projected for this study. All measurements were done during work time (9.00 a.m. to 2.00 p.m.). Mean values of the ventilation indices remained within the normal range but comparing results in smokers and non-smokers group significant differences in FEV1 and TGV were found. The symptoms of chronic bronchitis were present in 20.8% of persons. Spirometric criteria for the COPD diagnosis were found in 16 persons (11%). Only 5 persons (31%) were symptomatic. The mean decrease of FEV1 was 16.2 ml/yr, in the COPD group it was 82.5 ml/yr. The greater annual loss of FEV1 was found in the smokers and symptoms groups.

[Difficulties in diagnosis of specific pneumonia: clinical and pathomorphological confrontation]

Caseous pneumonia is one of acute kinds of tuberculosis. Difficulties in diagnosing of caseous pneumonia were described in this paper. Material contained 40 patients /28 men and 12 women/ mean age 53 +/- 16 years/ which died in The Hospital of Lung Diseases in Lódź. In this patients diagnosed caseous pneumonia. Analyse obtained many clinical parameters /age, sex, hospitalisation, period, investigation and medical, examination, results of bacteriological and radiological finding and autopsy diagnoses. Authors thought that the need of bacteriological examination and X-Ray examination in diagnosis of caseous pneumonia. Confrontation of clinical and pathomorphological diagnosis are very important.

Vascular endothelial growth factor regulates endothelial cell survival through the phosphatidylinositol 3'-kinase/Akt signal transduction pathway. Requirement for Flk-1/KDR activation

Vascular endothelial growth factor (VEGF) has been found to have various functions on endothelial cells, the most prominent of which is the induction of proliferation and differentiation. In this report we demonstrate that VEGF or a mutant, selectively binding to the Flk-1/KDR receptor, displayed high levels of survival activity, whereas Flt-1-specific ligands failed to promote survival of serum-starved primary human endothelial cells. This activity was blocked by the phosphatidylinositol 3'-kinase (PI3-kinase)-specific inhibitors wortmannin and LY294002. Endothelial cells cultured in the presence of VEGF and the Flk-1/KDR-selective VEGF mutant induced phosphorylation of the serine-threonine kinase Akt in a PI3-kinase-dependent manner. Akt activation was not detected in response to stimulation with placenta growth factor or an Flt-1-selective VEGF mutant. Furthermore, a constitutively active Akt was sufficient to promote survival of serum-starved endothelial cells in transient transfection experiments. In contrast, overexpression of a dominant-negative form of Akt blocked the survival effect of VEGF. These findings identify the Flk-1/KDR receptor and the PI3-kinase/Akt signal transduction pathway as crucial elements in the processes leading to endothelial cell survival induced by VEGF. Inhibition of apoptosis may represent a major aspect of the regulatory activity of VEGF on the vascular endothelium.

[Evaluation of angiogenic activity in sera from patients with interstitial lung diseases]

Angiogenesis is a process of new blood vessels' formation occurring in many physiological and pathological conditions. Neovascularisation is the principal vascular response in chronic inflammation and concomitant fibrotic process. Microvascular changes in various organ sites in sarcoidosis (BBS) and some of the symptoms of the disease may be related to microangiopathy. Moreover, vascular alterations were also observed in lung specimens from idiopathic pulmonary fibrosis (IPF) and avian fanciers lung (AFL) patients. The present study was aimed at testing the effects of serum from 43 patients with ILD (24 BBS, 8 AFL, 8 IPF, 3 DIPF--drug induced pulmonary fibrosis) and 11 healthy controls on angiogenic capability of normal blood peripheral mononuclear cells (PBMC) in the murine intradermal angiogenesis assay (according to Sidky and Auerbach). The data demonstrated that sera from ILD patients significantly enhanced angiogenic capacity of normal PBMC as compared to control sera (p < 0.001). The effect was more pronounced for AFL patients than for BBS and IPF ones (p < 0.05). Sera from DIPF did not stimulate angiogenesis compared to control sera. The data showed that sera from ILD patients constitute sources of mediators participating in angiogenesis. This phenomenon may play role in pathogenesis of chronic immunological processes in lung.

[Analysis of some exercise test parameters in patients 12 months after myocardial infarction]

This study comprised 102 patients (70 men--32 women) in mean age 57 +/- 7.8 year after noncomplicated myocardial infarction. Thirty five patients were after anterior infarction (group I), 36 after inferior infarction (group II) and 31 after subendocardial infarction (non Q wave) (group III). Exercise tests were performed always in morning, on ergometer Medicor. This study was continued until restriction symptoms appeared or until the limit of 85% of the pulse rate adequate to the age. Assessment of effort and load tolerance as well as ST segment depression on ECG and the kind of effort pain, was performed. The minimal tolerance of effort in patients after non Q infarction has been found. Coronary efficiency was the worst in patients after inferior and non Q myocardial infarction.

Immunomodulatory action of class mu-, delta- and kappa-opioid receptor agonists in mice

Endogenous opioids exert a variety of functions outwith the central nervous system, including modulation of some murine lymphocyte functions. The results of this study indicate that mu-, delta- and kappa-receptor selective agonists are potent in vitro stimulators of mitogen-induced proliferation of murine T-lymphocytes. Moreover, the observed enhancement of mitogen-induced proliferation was reversed by mu-, delta- and kappa-receptor class selective antagonists, beta-funaltrexamine, ICI 174,864 and nor-binaltorphimine, respectively. An additional study has revealed that repeated administration (four injections) of the opioid receptor selective agonists DAGO, DPDPE and U-50488 also enhanced the concanavalin A-induced proliferation of lymphocytes. These results suggest that there are three classes of opioid receptors on T-lymphocytes and that all these receptor classes are involved in the stimulation of concanavalin A-induced proliferation.

[Changes in the respiratory system of patients with rheumatoid arthritis--personal observations]

13 patients with RA admitted to our Institute with symptoms of respiratory involvement were described. Taking under consideration pulmonary function tests, radiological findings and histological examinations, we recognised 7 cases with interstitial lung disease, 3 cases with recurrent respiratory infection with bronchiectasis, 1 case with pleuritis, 1 with Caplan's syndrome and 1 with alveolar haemorrhage. The role of RF, and treatment with gold in the development of interstitial lung disease, as well as character of physiologic abnormalities concerning the small airways and its potential connection with bronchiolitis were discussed.

Augmenting effect of opioids on nitrite production by stimulated murine macrophages

The effects of methionine-enkephalin and the selective agonists of mu-, delta- and kappa-opioid receptor subtypes [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin, [D-Pen(2,5)]enkephalin U-50488 on the production of nitrite by activated peritoneal murine macrophages were studied. Macrophages were activated with interferon-gamma plus lipopolysaccharide in the presence or absence of graded concentrations of opioids. Methionine-enkephalin and mu-; delta- and kappa-agonists combined with interferon-gamma plus lipopolysaccharide caused an increase in nitrite release from cultured macrophages. Only 10 mM U-50488 led to a decrease in nitrite release from interferon-gamma and LPS-stimulated macrophages. This effect was not produced in a naloxone-sensitive manner. The opioids added to the fresh culture 8 h after the stimulation of macrophages by interferon-gamma plus lipopolysaccharide--when an inducible form of nitric oxide synthase activity is presumably expressed--did not alter the rate of nitrite production. This suggests that the effect of opioids on nitric oxide synthase is produced at the transcriptional level. The opioid receptor antagonist naloxone reduced the stimulatory effect of opioids on nitrite production by stimulated macrophages. Opioids added to the culture of resting macrophages did not change nitrite release from macrophages which were later induced with interferon-gamma plus lipopolysaccharide. The results of this study suggest that methionine-enkephalin can modulate the immune response by controlling, via opioid receptors, the production of nitric oxide.

Effects of fenofibrate on plasma cytokine concentrations in patients with atherosclerosis and hyperlipoproteinemia IIb

BACKGROUND AND OBJECTIVE

In recent studies atherosclerosis has often been referred to as immune disease. The atherosclerotic plaque consists of large amounts of inflammatory cells, mainly monocytes/macrophages and T lymphocytes. Macrophages activated by low-density lipoproteins (LDL) secrete tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) in vitro, while LDL-stimulated T lymphocytes release interferon gamma (IFN-gamma). The aim of this study was to estimate the plasma levels of TNF-alpha, IL-1, IFN-gamma in patients with hyperlipoproteinemia IIb (HLPIIb) and atherosclerosis. Since the fibrates are drugs of choice in HLPIIb, we additionally evaluated the effect of fibrates on the cytokine levels.

METHODS

Ten patients with HLPIIb were treated with micronized fenofibrate for 1 month. Before and after treatment, the cytokine levels were measured by the ELISA method. To accurately evaluate cytokine levels, we excluded atherosclerotic patients and control subjects with any inflammatory disease.

RESULTS

The initial lipid parameters were as follows: total cholesterol (TC): 6.9 +/- 0.24 mmol/l, triglycerides (TG): 3.44 +/- 0.53 mmol/l, LDL: 4.35 +/- 0.12 mmol/l, and apolipoprotein B (ApoB): 1.62 +/- 0.05 g/l. After 1 month of fenofibrate treatment the parameters decreased to the following values: TC 5.36 +/- 0.42 mmol/l (p < 0.05), TG 1.94 +/- 0.30 mmol/l (p < 0.05), ApoB 1.43 +/- 0.04 g/l (p < 0.01), and LDL 3.75 +/- 0.34 mmol/l (p > 0.05). Before therapy, TNF-alpha levels in atherosclerotic patients were higher than in control subjects, 19.2 +/- 1.6 and 9.9 +/- 1.1 pg/ml, respectively (p < 0.01). After 1-month therapy, TNF-alpha levels in atherosclerotic patients were 9.2 +/- 1.0 pg/ml (p < 0.01). Similarly, the initial levels of IFN-gamma were higher in atherosclerotic patients compared with healthy subjects, 44.4 +/- 5.3, and 19.4 +/- 2.1 pg/ml, respectively (p < 0.01). After fenofibrate therapy, IFN-gamma levels decreased to 24.8 +/- 2.9 pg/ml (p < 0.01). The decreased levels of TC, TG, and LDL correlated with the decreased levels of TNF-alpha and IFN-gamma.

CONCLUSION

The results of this study indicate that plasma TNF-alpha and IFN-gamma levels in hyperlipidemic patients are higher than in healthy subjects, and that fenofibrate is effective in decreasing lipids and cytokines in plasma.

Influence of Neuroleptics on Cytotoxic Activity of Rat Natural Killer Cells

The aim of the study was to evaluate the in vivo and in vitro effects of three neuroleptics (chlorpromazine, haloperidol, and sulpiride) on the activity of rat spleen NK cells. In the in vivo experiment, rats were injected with different intraperitoneal doses of neuroleptics given once, for 14 or 28 days. In the in vitro experiment rat spleen NK cells were cultured in medium containing two different concentrations of neuroleptics for three days. The cytotoxic activity of NK cells was evaluated by measuring 51Cr release from YAC-1 target cells after 4-hour incubation. We also measured, using fluorescein-labelled anti-NK monoclonal antibody, the percentage of NK cells in the splenocyte population before and after single intraperitoneal injections of neuroleptics. In the in vitro experiment, both haloperidol (1×10−5M and 1×10−6M) and sulpiride (1.5×10−3M and 1.5×10−4M) induced a statistically significant decrease in the cytotoxic activity of NK cells. The lower dose of chlorpromazine (6×10−6M) decreased the cytotoxic activity of NK cells, while the higher dose (6×10−5 M) did not. In the in vivo experiment, both single and repeated doses of chlorpromazine (2 mg /kg /day), haloperidol (0.5 mg/kg/day) and sulpiride (50 mg/kg/day) increased NK cell activity. That effect reflected an increase in NK cell activity but not in the number of NK cells. The study has shown that the immunomodulatory effect of neuroleptics on NK cell activity depends mainly on drug concentrations and experimental conditions.

Influence of neuroleptics on cytotoxic activity of macrophages in rats

The aim of the study was to evaluate the influence of neuroleptics on the in vivo and in vitro activities of rat spleen macrophages. In the in vivo study, three neuroleptics (chlorpromazine, haloperidol, and sulpiride) were given once, for 14 or 28 days. In the in vitro study, we evaluated the effects of two different concentrations of the neuroleptics on 3-day cultures of spleen macrophages. Rat spleen macrophages were isolated by the adherence method, and their cytotoxic activity was determined by measuring 51 Cr release from target cells P-815. In the in vitro study, both concentrations of all neuroleptics did not alter the cytotoxic activity of macrophages. In the in vivo study, neuroleptics (chlorpromazine 2 mg/kg, haloperidol 0.5 mg/kg, sulpiride 50 mg/kg) enhanced the cytotoxicity of macrophages both after a single injection and after 14 days. The results of the study indicate that the immunomodulatory effects of the neuroleptics depend mainly on dosage and experimental conditions.

Immunologic action of [Met5]enkephalin fragments

The aim of this study was to evaluate the effects of [Met5]enkephalin, des-Met-[Met5]enkephalin, des-Tyr-[Met5]enkephalin, and Tyr-Gly-Gly on natural killer cytotoxic activity and on concanavalin A- and lipopolysaccharide-stimulated proliferation of B and T cells in mice. Single i.p. injections of [Met5]enkephalin, des-Met-[Met5]enkephalin, and Tyr-Gly-Gly increased both natural killer cytotoxicity and proliferation of mitogen-stimulated B and T cells. These effects were inhibited by naloxone pretreatment, which suggests the opioid mechanism of the peptides studied. The rate of lymphocytic proliferation increases not only after single injection of [Met5]enkephalin or its metabolites, but also after 3 or 7 days of treatment. Apart from the functional effects, [Met5]enkephalin, des-Met-[Met5]enkephalin, and Tyr-Gly-Gly increased the percentages of natural killer cells and T cells. The results of this study suggest that the immunomodulatory action of [Met5]enkephalin may be mediated or enhanced by its N-terminal metabolites des-Met-[Met5]enkephalin and Tyr-Gly-Gly.

[Levels of tumor necrosis factor alpha in serum of patients with hyperlipoproteinemia IIB before and after micronized fenofibrate therapy]

Tumor necrosis factor alpha (TNF alpha) secreted by activated macrophages stimulates proliferation and migration of vascular smooth muscle in atherogenesis. Up to now, the effect of fibrates on concentration of TNF-alpha has not been investigated. The aim of this study was to estimate TNF-alpha plasma concentration in healthy subjects before and after fenofibrate therapy in patients with hyperlipoproteinaemia IIb and to correlate their levels with plasma concentration of total cholesterol (TC), low density lipoproteins (LDL) and apolipoprotein B (ApoB).

METHODS

10 patients with hyperlipoproteinaemia IIb were treated with micronized fenofibrate (Lipanthyl 200 m-Fournier) for 1 month. Cytokines levels before and after therapy was measured by the ELISA method with Genzyme kits.

RESULTS

The levels of lipid parameters at the onset study were as follows: TC: 265.4 +/- 9.4 mg%, TG: 344 +/- 53 mg%, LDL: 167.2 +/- 4.7 mg%, and ApoB: 1.62 +/- 0.05 g/l. After 1-month therapy with Lipanthyl 200 m the parameters decreased: TC 206 +/- 16 mg% (p < 0.05), TG: 194 +/- 30 mg% (p < 0.05), ApoB: 1.43 +/- 0.04 g/l (p < 0.01), and LDL: 144.4 +/- 12.9 mg% (ns). The decreased level of TC, TG and LDL correlated with the decreased concentration of TNF alpha. Before treatment the TNF concentration was 19.2 +/- 1.6 pg/ml and was higher than the concentration of control subjects (9.9 +/- 1.1 pg/ml, p < 0.01). After 1-month therapy the level of TNF alpha in blood from patient was 9.2 +/- 1.0 pg/ml (p < 0.01). The results of this study indicate that the concentrations of TNF alpha in plasma from hyperlipidemic patients are higher than concentrations of healthy subjects. Fenofibrate decreased the levels of this cytokine. This effect may be of significance for the treatment of HLPIIb and of atherosclerosis prevention.

[The effect of pentoxifylline on oxidative metabolism in neutrophils primed with tumor necrosis factor alpha in patients with stable angina pectoris]

In 14 patients with stable angina pectoris we examined the effect of pentoxifyline (PTX) on oxidative metabolism of TNF-alpha-priming neutrophils. The control group consisted of 21 patients with stable angina pectoris without pentoxifylline administration. Blood samples for examination were taken from basilic vein (peripheral blood) and coronary sinus immediately before PTCA procedure. In PTX-group was found the significant decrease in spontaneous CL of TNF-alpha-priming neutrophils from coronary sinus blood (1231.0 +/- 119.4 mV x min), in comparison to the control group (1374 +/- 124.4 mV x min). In PTX-group was found the significant decrease in fMLP stimulated CL of TNF-alpha-priming neutrophils from peripheral blood (4219.0 +/- 707.2 mV x min) and coronary sinus blood (4322.0 +/- 664.4 mV x min), in comparison to the control group (5248.0 +/- 595.8 mV x min and 4973.0 +/- 536.5 mV x min; respectively). There were no differences between both groups in PMA stimulated CL of TNF-alpha-priming neutrophils.

[Chemical control of breathing in patients with obstructive sleep apnea]

The authors have studied chemical control of breathing in 37 normocapnic patients with OSA. These patients had increased apnea-hypopnea index (AHI = 51 +/- 22), obesity (BMI = 32.4 +/- 5.6 kg/m2) and normal lung function tests. Control group consisted of 20 healthy subjects with normal weight (BMI = 23.1 +/- 2.4 kg/m2). Respiratory responses (ventilatory and P0.1) to hypercapnic and hypoxic stimulation during rebreathing tests were measured with computerized methods. The obtained results in OSA patients were compared with the data of the control group. The results exceeding mean values of the control group above 1.64 SD were recognized as hyperreactive responses. The majority e.g. 26 patients (OSA-N) had normal respiratory responses during hypercapnic stimulation. delta V/delta PCO2 = 16.8 +/- 4.5 L/min/kPa, P0.1/delta PCO2 = 3.5 +/- 2.4 cm H2O/kPa/. In remaining 11 patients (OSA-H) respiratory responses were significantly increased delta V/delta PCO2 = 39.1 +/- 18.8 L/min/kPa, P0.1/delta PCO2 = 8.6 +/- 3.9 cm H20/kPa). During isocapnic hypoxic stimulation majority e.g. 25 patients (OSA-H) had significantly increased respiratory responses delta V/delta SaO2 = 3.28 +/- 1.63 L/min/%, delta P0.1/delta SaO2 = 0.54 +/- 0.43 cm H2O/%/. In remaining 12 patients (OSA-N) respiratory responses were within normal limits delta V/SaO2 = 1.2 +/- 0.28 L/min/%, delta P0.1/ delta SaO2 = 0.21 +/- 0.07 cm H2O/%/. The above results indicated, that majority OSA patients (67.5%) had increased ventilatory and P0.1 responses to hypoxic stimulation. Among them also 11 patients had increased respiratory responses to hypercapnia. It seems, that increased respiratory responses to hypoxic stimulus in OSA patients are symptoms of protective reaction to hypoxaemia occurring during repetitive sleep apnoea and reveals increased neuro-muscular output.

[Evaluation of respiratory muscle strength in patients with interstitial lung changes based on simultaneous measurement of esophageal and mouth pressure]

A well know good relation between nasal and oesophageal inspiratory pressures exists in healthy and in COPD patients "sniff manoeuvres. Similar results are obtained using "gasp" maneuvers. The aim of the study was to appreciate the usefulness of "gasp" for evaluation of inspiratory muscles strength in ILD patients. 18 ILD patients were examined: group A consisted of 9 pts (8M+IF) aged 35 +/- 8.6 yrs, with static compliance > 70% pred. (mean 98.6 +/- 16.3), group B consisted of 9 pts (6M + 3F) (aged 52 +/- 13.0) with static compliance < 70% pred. (mean 37.2 +/- 12.0), Pmo and Poe (Milic-Emili method) were measured simultaneously during breathing with Pflex device (1.7 mm diameter). Results were stored in a computer for further analysis. In all patients spirometry, plethysmography and maximal inspiratory (MIP) and maximal expiratory (MEP) pressure measurements were performed. Poe and Pmo in group A were nearly the same (8.16 +/- 1.82 vs. 8.35 +/- 2.74 kPa), but in the group B Pmo was lower than Poe (4.81 +/- 1.59 vs. 6.19 +/- 2.03 kPa; p < 0.0005). We conclude that "gasp" - Pmo is a useful method for inspiratory muscle strength measurement only in ILD patients with normal static compliance but in ILD patients with decreased compliance "gasp" - Poe measurement in necessary.

The flow-volume curve in patients with obstructive airway diseases partial analysis and functional importance

Flow-volume curves in patients with obstructive airway disease differs from that observed in healthy subjects. Two types of pathological curves can be differentiated: these with clear sharp bend and intermediate forms characterised by the different grade of concavity of the descending segments plotted against X-axis. The aim of our present investigation is to elucidate the mechanisms which determines the forced expiratory airflow course in patients with obstructive airway diseases. Patients with sharp bend curves show changes of the several lung function data which are more advanced than in subjects with the intermediate forms of the flow-volume curves. In cases of bend curves the volume of the forced expiration can be differentiated on the two parts: circumferential and serial. Circumferential volume exhaled on the very beginning of the expiration (above the bend) amounts 0.118L in average. This volume depends on the expiratory narrowing of the bronchi from the 1-st to 9-th generation. The serial volume contained between the bend and the end of expiration amounts about 95% of the expired volume. Flow limitation occurs in 5-th to 9-th generations which is manifested by the strong increase of the flow resistance. The intermediate types of the flow-volume curves is caused by the inhomogenous emptying of the lung together with corresponding volume dependent narrowing of the bronchi. The same mechanisms can be detected even on the bodypletysmographic tidal breathing resistance curves. The concave and particularly bend flow-volume curves has been attributed to the pulmonary emphysema. This is not entirely truth. Other conditions leading to inhomogenic emptying of the lung due to airway and parenchymal changes (such as lung cicatrisation) can influence expiratory flow course resulting in concave or even bend flow-volume relationships.

[Pattern of breathing and obstruction pressure in patients with airway obstruction after inhalation of bronchodilators]

The neuromuscular drive is increased in patients with an airway obstruction. The aim of the study was to estimate an influence of beta-agonist on breathing pattern and mouth occlusion pressure (P0.1) in patients with reversible and nonreversible airway obstruction. Ventilatory function tests, pattern of breathing analysis, mouth occlusion pressure (P0.1) and inspiratory impedance (P0.1/Vt/Ti) were measured in 23 obstructive patients and 20 healthy subjects. In all patients these measurements were repeated 20 minutes after bronchodilator inhalation (0.2 mg fenoterol). During quiet room-air breathing in patients we observed increased Vt, Vt/Ti comparing with healthy persons. The time of inspiration (Ti) and total time (Ttot) were shortened in comparison to our control group. P0.1 and inspiratory impedance were significantly increased (P0.1 3.6 +/- 1.6 vs 1.6 +/- 0.3 cm H2O, p < 0.01 and P0.1/Vt/Ti 6.6 +/- 2.3 vs 3.8 +/- 1.0 cm H2O/L/s). Measurements performed after bronchodilator inhalation revealed decrease of P0.1 and P0.1/Vt/ Ti in patients responsive to beta-agonist (delta FEVI > 15%). In unresponsive patients (delta FEVI < or = 15%) such decrease in neuromuscular respiratory drive was not observed. We conclude that diminishing of increased neuromuscular respiratory drive in patients with reversible obstruction is a consequence of airway resistance decreasing. It seems to be an additional, advantageous for a patient, effect of bronchodilator inhalation.