[Cardiopulmonary Exercise Testing (CPET) in severe COPD--a multicentre comparison of two test protocols]. / Spiroergometrie bei Patienten mit chronisch obstruktiver Lungenerkrankung--multizentrischer Vergleich von zwei Belastungsprotokollen.

Cardiopulmonary exercise testing (CPET) allows a valid evaluation of cardiopulmonary function capability and the recognition of existing limitations in COPD patients. Whereas the measurement of the different parameters of CPET and the evaluation of the results are standardised, this does not apply to the protocols chosen. The aim of this study was to evaluate whether the results of two different exercise protocols were comparable in an outpatient multicentre setting. Ninety COPD patients stages II-IV according to the Gold classification were examined by means of symptom-limited exercise testing on a bicycle with two different ramp protocols (10 Watts vs. 16 Watts/min) within seven days. The results show that a higher acceleration rate of the load was associated with shorter exercise duration and higher achieved exercise capacity. Gas exchange and ventilatory parameters did not show significant differences on comparing both protocols. In pulmonary practices COPD patients of the Gold stages II-IV can be examined safely and with validity by means of CPET. The application of a ramp protocol with a stepwise increase of 16 Watts/minute can be recommended, particularly as for this regimen standardised normal values are available.

[Modern impulse oscillometry in the spectrum of pulmonary function testing methods]. / Die moderne Impulsoszillometrie im Spektrum lungenfunktioneller Messmethoden.

Impulse oscillometry (IOS) is a computer supported method for the measurement of complex mechanical airway characteristics. Bronchial obstructions can reliably be diagnosed by IOS when more complex parameters such as frequency dependence of resistance (FDR) and lung reactance (X5) are evaluated in cases with more severe obstruction. Parameters of conventional methods like pneumotachography, spirometry, and bodyplethysmography show relatively low correlations due to the different measurement principles, not only in comparison to IOS, but also in between one another. The IOS is a convenient method for patients with a low dependency on cooperation for the evaluation of obstructive airway diseases complementary to the established standard methods. Furthermore, IOS may provide a sensitive screening tool for the early detection of bronchial obstructions not only in paediatrics but also in occupational medicine.

[Impulse oscillometry in the diagnosis of the severity of obstructive pulmonary disease]. / Die Impulsoszillometrie in der Schweregraddiagnostik obstruktiver Lungenerkrankungen.

Impulse oscillometry (IOS) is a computer-supported method for the measurement of complex mechanical airway characteristics. The aim of this study was to evaluate the applicability of IOS in the diagnosis of obstructive airway diseases in comparison to the standard methods of spirometry, pneumotachymetry, and bodyplethysmography. 244 patients (age 61.5 +/- 13.6 years; 61 % men) with bronchial asthma (n = 65) and chronic obstructive pulmonary disease (COPD) (n = 179) were retrospectively analysed. By means of body plethysmography (Srtot < 120%pred) an obstruction was diagnosed in 94%, by pneumotachymetry (FEV1 < 80%pred) in 78 %, and by IOS depending on the parameter chosen in 87-94% of patients. Mild and medium obstructions could be identified by means of all IOS parameters except for R20: severe obstructions, however, were better detected by means of the frequency-dependent resistance FDR and reactance at 5 Hz, X5. The parameters R5, X5, and Zrs, however, showed a tendency to underestimate the degree of obstruction. Bronchial obstruction can reliably be diagnosed by IOS when, in cases of severe obstruction, more complex parameters like FDR and X5 are included. The parameters of the standard methods (body plethysmography and pneumotachymetry) show relatively low correlations due to the different measurement methods not only in comparison to IOS but also to one another. In summary, IOS is a convenient method for patients with a low dependency on cooperation for the evaluation of obstructive airway diseases complementary to the established standard methods and, in addition, is useful as a sensitive screening tool for the early detection of bronchial obstruction.

[Tuberculosis and travelling]. / Tuberkulose und Reisen.

Tuberculosis (TB) in Germany in the year 2007 with 5020 reported cases (incidence: 6.1 newly diagnosed cases per 100 000 inhabitants) was continuously in decline. 43.1 % of these persons were from countries with a higher TB incidence as compared to Germany. However, not only migration but also personal journeys from low- to high-incidence countries carries an increased risk of infection with M. tuberculosis (MTB). An early active TB follows only rarely, more common, however, is a latent TB infection (LTBI). Not only the active form of TB but also LTBI, with a potential for reactivation years or decades later, can be of enormous relevance for the individual and the social environment. The early detection of an MTB infection and its possible sequelae are decisive for a continued successful battle against tuberculous diseases, especially in view of increasing travel activities.

[Friend or foe: combination therapy with inhaled corticosteroids and long-acting beta2-agonists in chronic obstructive pulmonary disease (COPD)]. / Indikationen und Limitationen einer fixen Kombinationstherapie mit inhalativen Kortikosteroiden und langwirksamen beta2-Mimetika bei der chronisch-obstruktiven Lungenerkrankung (COPD).

Inhaled corticosteroids (ICS) used in COPD (chronic obstructive pulmonary disease) are recommended only in combination with a long-acting beta2-agonist (LABA) in stage 3 and higher in COPD treatment guidelines. In comparison to placebo and the single components, a superior control by means of the ICS/LABA fixed combination therapy has been demonstrated for clinical improvement in the following parameters: reduction of exacerbation rate and hospitalisations, reduction of dyspnoea and improvement of forced expiratory volume in one second (FEV1). In contrast to data from database studies, the large prospective TORCH (Towards a Revolution in COPD Health) trial found in the ICS/LABA group a beneficial effect on the reduction of mortality only as a trend in the ICS/LABA group, which did not reach statistical significance. In long-term trials, ICS treated patients experienced up to 10% oral and/or pharyngeal candidiasis. ICS was associated with an excess risk of pneumonia, which doubles the pneumonia incidence in patients not receiving ICS. The probability of having pneumonia reported as an adverse event was 18-19 % in the ICS groups and resulted in a 1.7-2.2 elevated pneumonia risk. Because ICS therapy is recommended only in conjunction with a bronchodilator, fixed ICS/LABA combinations are a logical consequence for COPD long-term therapy.

[Clinical features and diagnosis of bronchopulmonary infections in the elderly]. / Klinik und Diagnose bronchopulmonaler Infektionen im Alter.

Diseases of the lung are one of the main causes of morbidity and mortality in the elderly. The risk of respiratory infections is increased due to structural changes, malnutrition, co-morbidity, and a variety of other factors. Bacterial and viral pathogens cause acute bronchitis and exacerbations of chronic bronchitis (AECB). Community acquired pneumonias (CAP) show a different spectrum of pathogens and clinical course in comparison to nosocomial pneumonias (hospital acquired pneumonia, HAP). Institutionalised patients are at risk of a health care associated pneumonia (HCAP), with often a different spectrum of pathogens in comparison to CAP and HAP. Elderly patients with cerebrovascular disease and impairment of swallowing or cough reflexes often suffer from aspiration pneumonias. The mortality is highest in the elderly, comorbid, and immunocompromised patient with nosocomial pneumonia. Important preventive measures include influenza and pneumococcal vaccination, avoidance of immobility, oral hygiene, and sufficient nutrition.

Treatment of invasive pulmonary aspergillosis in neutropenic patients by additional bronchoscopic amphotericin B instillation.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) remains a life-threatening condition despite systemic antifungal therapy. OBJECTIVES: This retrospective analysis investigated whether additional bronchoscopic instillation of amphotericin B (amB) would improve efficacy of antifungal treatment in patients with haematological malignancies suffering from IPA. METHODS: Twenty patients (40.6 +/- 14.2 years, 14 male) with preceding chemotherapy, bone marrow or stem cell transplantation complicated by severe IPA who did not respond sufficiently to systemic antifungal therapy were additionally treated by repeated bronchoscopic instillations of amB solution (91 instillations, on average 4.6 +/- 2.2 instillations per patient over a period of 24.1 +/- 21.0 days). Therapeutic response to this combined treatment regimen was monitored by chest X-ray and CT scan. RESULTS: The mean infiltration sizes during systemic antifungal therapy alone (mean duration 11.9 +/- 9.9 days) did not change significantly. However, after additional bronchoscopic instillation of amB solution infiltration sizes were reduced significantly (p < 0.05). A total resolution of infiltrates was seen in 3 and a partial reduction in 13 of 20 patients. Mean duration of total antifungal treatment was 50.1 +/- 24.0 days. The mean follow-up period was 34.1 +/- 31.2 months. The IPA-related mortality rate was 18.8% (3 of 16 patients). CONCLUSIONS: Additional bronchoscopic instillation of amB may improve the efficacy of systemic antifungal therapy in patients with haematological malignancies complicated by severe IPA. Bronchoscopic instillation of amB should be considered as an additional treatment option in cases with IPA unresponsive to systemic therapy.

Transgenes sustain epigeal insect biodiversity in diversified vegetable farm systems.

Many ecological studies have focused on the effects of transgenes in field crops, but few have considered multiple transgenes in diversified vegetable systems. We compared the epigeal, or soil surface-dwelling, communities of Coleoptera and Formicidae between transgenic and isoline vegetable systems consisting of sweet corn, potato, and acorn squash, with transgenic cultivars expressing Cry1(A)b, Cry3, or viral coat proteins. Vegetables were grown in replicated split plots over 2 yr with integrated pest management (IPM) standards defining insecticide use patterns. More than 77.6% of 11,925 insects from 1,512 pitfall traps were identified to species, and activity density was used to compare dominance distribution, species richness, and community composition. Measures of epigeal biodiversity were always equal in transgenic vegetables, which required fewer insecticide applications than their near isolines. There were no differences in species richness between transgenic and isoline treatments at the farm system and individual crop level. Dominance distributions were also similar between transgenic and isoline farming systems. Crop type, and not genotype, had a significant influence on Carabidae and Staphylinidae community composition in the first year, but there were no treatment effects in the second year, possibly because of homogenizing effects of crop rotations. Communities were more influenced by crop type, and possibly crop rotation, than by genotype. The heterogeneity of crops and rotations in diversified vegetable farms seems to aid in preserving epigeal biodiversity, which may be supplemented by reductions in insecticide use associated with transgenic cultivars.

Coccinellids, aphids, and pollen in diversified vegetable fields with transgenic and isoline cultivars.

The influence of concurrent introduction of three transgenic vegetable cultivars on seasonal dynamics of coccinellids and their food, aphids and pollen, was examined within diversified farm systems practicing insect pest management in northeastern US agroecosystems. The transgenic cultivars used included sweet corn, potato, and winter squash, expressing Cry1(A)b, Cry3A, and plant viral coat proteins that target Lepidoptera, Coleoptera, and aphid-transmitted viruses, respectively. Transgenic systems reduced insecticides by 25%. Weekly differences in coccinellid density between transgenic and isoline crops were rare and transitory, governed by timing of at-planting or foliar insecticide use patterns; however cumulative frequencies for three of the six coccinellid species differed between transgenic and isoline crops. At a multicrop, farm systems level, seasonal dynamics of the coccinellids and aphids tracked dynamics in the sweet corn, which far surpassed the other crops in abundance of coccinellids and pollen, and harbored consistently higher aphid densities. Although these results warrant further study, the patterns suggest that diversified transgenic vegetable crops under current commercial management demonstrated transitory conservation of coccinellids, and that integration with selective insecticides or other IPM tactics could increase this potential.

Real-life effectiveness of asthma treatment with a fixed-dose fluticasone/formoterol pressurised metered-dose inhaler - Results from a non-interventional study.

OBJECTIVE: Prospective, non-interventional study of fixed-dose inhaled corticosteroid (ICS)/long-acting beta2-agonist (LABA) combination therapy with fluticasone propionate/formoterol fumarate (FP/FORM) across a spectrum of community-based patients with asthma in a real-life setting. METHODS: In FP/FORM-treated patients aged ≥12 years, asthma control (Asthma Control Test™ [ACT]), incidence of severe exacerbations, lung function, quality of life (asthma quality of life questionnaire [AQLQ]) and adverse events (AEs) were assessed over one year. RESULTS: Almost 40% (n = 555) of the full analysis population (N = 1410) were receiving ICS/LABA therapy prior to enrolment; 69.8% completed the study. Asthma control (mean ACT ± standard deviation) improved from 16.3 ± 5.0 at baseline to 19.8 ± 4.5 at study end. ACT scores were significantly (p < 0.0001) higher than baseline at all observation timepoints, including the first assessment at 4-6 weeks. The percentage of patients with asthma control increased (baseline: 30.9%; study end: 62.4%), and the percentage of patients with ≥1 severe asthma exacerbation decreased (12 months before: 35.8%; during study: 5.9%). Lung function (forced expiratory volume in one second, peak expiratory flow) improved from baseline to each observation timepoint (p < 0.0001 for all). Improvement in asthma status was accompanied by ameliorated quality of life: AQLQ scores improved significantly from baseline to all observation timepoints (p < 0.0001 for all). AEs accorded with the summary of product characteristics. After study completion, 70% of patients continued FP/FORM treatment. CONCLUSION: In this one-year study, FP/FORM treatment was associated with clinically relevant improvements in asthma status in a diverse population of patients under real-life conditions.

[Acute bronchitis: when are antibiotics, and when is symptomatic treatment indicated?]. / Akute Bronchitis. Wann symptomatisch, wann mit Antibiotika behandeln?

Acute bronchitis is usually caused by a virus, while the chronic form is due to inhalative noxae (in most cases decades of cigarette smoking). Both varieties are diagnosed on a clinical basis. Treatment of acute bronchitis is symptomatic. A sore throat is treated locally, and a troublesome, in particular nocturnal, cough with antitussive agents applied for a limited period (14 days). If bronchial mucus is viscous and difficult to clear, short-term treatment with a secretolytic or mucolytic substance is justified. Management of chronic bronchitis consists primarily in the elimination of the noxae. Treatment with antibiotics (usually oral) makes good sense only when there is a bacteriological infection of the upper or lower airways in an acute stage, such as infection-driven exacerbation of chronic obstructive bronchitis (COPD).

Occurrence of matrix metalloproteinases and tissue inhibitors of metalloproteinases in tuberculous pleuritis.

OBJECTIVE: Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) have been found in high concentrations in pleural effusions. Because MMP and TIMP may play a part in the causation of the fibrosis seen in tuberculous (TB) pleuritis their occurrence was examined. DESIGN: Pleural effusion fluid and plasma concentrations of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1 and TIMP-2 were determined by ELISA in 21 patients with TB pleuritis. To adjust for the total protein content, respective ratios were calculated. Activities of MMP-2 and MMP-9 were measured by gelatine zymography and the MMP-9/MMP-2 ratios calculated. Pleural effusions and plasma of 15 patients with congestive heat failure (CHF) and plasma of 15 healthy persons (CON) served as controls. RESULTS: Immunoreactive pleural fluid concentrations of MMP-1, MMP-2, MMP-8, and MMP-9 were higher in TB compared to CHF, but plasma concentrations were not different between the groups. TB pleural fluid concentrations of MMP-1, MMP-2, TIMP-1, and TIMP-2 were higher compared to TB plasma. MMP-3 was found in trace amounts only. The MMP-9/total protein ratios in pleural fluid were higher in TB compared to CHF (0.4492+/-0.1633 vs 0.0364+/-0.0145, P<0.005) but the TIMP-1 ratios were lower (139.0+/-28.7 vs 517.8+/-183.7, P<0.0005). In TB pleural fluid vs TB plasma, the respective MMP-1, MMP-2, TIMP-1, and TIMP-2 ratios were increased (0.46+/-0.10 vs 0.17+/-0.02; 25.2+/-2.8 vs 4.2+/-0.9; 139.0+/-28.7 vs 27.8+/-8.2; 0.67+/-0.13 vs 0.18+/-0.04, P<0.0005 each). Gelatine zymography demonstrated MMP-2 and MMP-9 bands of different brightness in TB effusions but in CHF effusions the MMP-9 band was barely visible. The MMP-9/MMP-2 effusion ratios were therefore higher in TB compared to CHF (0.46+/-0.15 vs 0.05+/-0.04, P<0.0005). CONCLUSION: Compartmentalized MMP-1, MMP-2, TIMP-1, and TIMP-2 and, compared to CHF, a surplus of MMP-1, MMP-2, MMP-8, and MMP-9 in the pleural space obviously contribute to the fibrotic reactions in TB pleuritis.

Time-of-flight secondary ion mass spectrometry of matrix-diluted oligo- and polypeptides bombarded with slow and fast projectiles: positive and negative matrix and analyte ion yields, background signals, and sample aging.

Human angiotensin II, chain B of bovine insulin, and porcine insulin were determined by time-of-flight secondary ion mass spectrometry under impact of approximately 25 keV Xe+ and SF5+ ion beams and approximately 100 MeV 252Cf fission fragments. Matrix-embedded samples, dissolved in a large surplus of alpha-cyano-4-hydroxycinnamic acid, were prepared by nebulizer spray deposition, neat samples by the droplet technique. It is shown that the status of the sample can be assessed by evaluating the matrix-specific features of the mass spectra. The beneficial effect of matrix isolation was small for angiotensin but large for the insulin samples, which did not show parent peaks from neat material. Negative ion yields under SF5+ impact were up to a factor of 50 higher than with Xe+. For positive secondary ions, the enhancement was much smaller. The mass spectra produced by slow ion beams or fast fission fragments were qualitatively similar. Quantitative differences include the following: with fast projectiles the yields were about 10-30 times higher than with slow ions, but similar for negative ion emission under SF5+ bombardment; the analyte-to-matrix yield ratios were higher with slow ions and up to 250 times higher than the molar analyte concentration; for analyte ions the peak-to-background ratios were higher using slow projectiles; the fraction of carbon-rich collisionally formed molecular ions was much higher with fast projectiles. Sample aging in vacuum for up to five weeks strongly reduced the yield of protonated analyte molecules ejected by slow ion impact, but not of deprotonated species. Hence protonation seems to correlate with sample "wetness" or the presence of volatile proton-donating additives.

Increased soluble CD14 levels in BAL fluid in pulmonary tuberculosis.

INTRODUCTION: CD14 is a cell surface glycoprotein expressed mainly on mature monocytes and macrophages. Soluble CD14 (sCD14) is present in normal plasma and is found increased in serum of patients with septicemia, polytrauma, and sarcoidosis. In active sarcoidosis, increased levels of sCD14 in BAL supernatant have been demonstrated. STUDY OBJECTIVE: To investigate sCD14 levels in BAL of pulmonary tuberculosis (PTB), another inflammatory disease characterized by granuloma formation. METHODS: BAL was performed in 12 patients with active but untreated PTB and 12 healthy persons. Cytologic and immunocytologic characteristics were determined. sCD14 was measured by a sandwich enzyme-linked immunosorbent assay. RESULTS: The level of sCD14 in patients with PTB was increased compared with controls (mean +/- SEM: 34.4 +/- 9.6 ng/mL vs 11.5 +/- 2.2 ng/mL; p = 0.02). No correlation was found between sCD14 levels and BAL cell differentials or lymphocyte surface markers. CONCLUSION: Similar to sarcoidosis, increased levels of sCD14 are found in BAL supernatant of PTB patients.

The effect of corticotropin-releasing hormone (CRH) on the adrenal medulla in hypophysectomized rats.

CRH occurs in the adrenal medulla of rats. We were interested to know whether CRH affects meduallary chromaffin cells in the absence of ACTH. We investigated the morphological changes of the adrenal medulla in Sprague Dawley rats with light and electron microscopy in normal rats, hypophysectomized rats, and hypophysectomized rats following injections of CRH (10 micrograms = 3 nmol for three days). Chromaffin cells were characterized by immunohistochemistry (anti-tyrosine hydroxylase). At light microscopy level chromaffin cells of hypophysectomized rats were reduced in number. On electron microscopy the number of granules and cell organelles were decreased. Following injections of CRH the medulla regained a more compact texture with cell organelles homogenously distributed, but with chromaffin granules still being reduced in number. Immunohistochemistry allowed the identification of chromaffin cells located within the adrenal cortex. In hypophysectomized rats these cells showed fewer signs of alterations compared to cells located within the medulla itself and had recovered better after treatment with CRH. In conclusion, CRH seems to exert a trophic effect on chromaffin cells in the absence of pituitary ACTH. This observation may provide further evidence for a close interaction of the two neuroendocrine stress systems.

Peptide containing vesicles within neuro-neuronal synapses.

In the descending part of the classical neurosecretory system, the axon terminals are not differentiated or they take the form of presynaptic elements which then form synaptoids or synapses with pituicytes or adenohypophyseal glandular cells respectively. In contrast, the axon terminals of the ascending part fulfil the criteria of true presynaptic elements which form synapses with other neurones. The presence of neurophysin vesicles in the presynaptic element is a particular morphologic feature of these neuro-neuronal synapses.

Endobronchial tuberculosis: diagnostic features and therapeutic outcome.

BACKGROUND: Endobronchial tuberculosis (EBTB) is not seen often in the adult population. In most cases it is associated with pulmonary tuberculosis. During its course significant tracheobronchial stenosis may develop. In this study we report our experience with patients with EBTB. METHODS: The records of 38 patients in whom EBTB had been proved by fibre optic bronchoscopy, microbiology and histology studies were evaluated. RESULTS: Symptoms were non-specific and represented mainly the co-existing pulmonary tuberculosis. Signs characteristic of airway obstruction were rare (localized wheezing in 6%). Indications for bronchoscopy were radiographic features (87%), microscopy smear negatives (8%), wheezing (3%), and blood stained sputum (3%). The lesions were more likely to be seen in the main and upper bronchi. In 5% of patients the lower trachea was involved. Most lesions looked inflamed (51%), followed by caseous (19%), granulomatous (17%), ulcerative (12%), and fibrotic appearance (1%). The degree of stenosis was nil (22%), minor (45%), significant (13%), subtotal (13%), or total (7%). The patients were treated with a combination of antituberculosis drugs. Four patients underwent surgical procedures. Dilatation techniques were used in two patients for a right and left main bronchus stenosis respectively, with significant improvement in one. Dilatation in combination with laser therapy of a right intermediate bronchus stenosis did not result in re-expansion of the dependent part of the lung due to pleural adhesions. Left pneumonectomy was performed in one patient for destroyed lung. Twenty-two patients agreed to follow up bronchoscopy. The macroscopic appearance of the mucosa had improved in most cases but the degree of stenoses was unchanged in a considerable proportion (58%). Bronchial stenosis in one patient subsided during therapy but developed again at a later stage. CONCLUSIONS: Patients with pulmonary tuberculosis and radiographic evidence of volume loss are recommended to undergo bronchoscopy to rule out EBTB. Specific symptoms for EBTB are rare. Biopsy of inflamed areas of bronchial mucosa seems to be indicated. Despite adequate antituberculosis therapy tracheobronchial stenosis may develop. Long term follow up including bronchoscopy seems therefore advocated. Dilatational intervention may be indicated in selected cases.

Compartmentalization of pro-inflammatory cytokines in tuberculous pleurisy.

Increased levels of interleukin-6 (IL-6) and IL-8 are found in various immunologically mediated inflammatory disorders. Concentrations of IL-6, IL-8 and the soluble form of the IL-6 receptor (sIL-6R) were determined in serum and effusion fluid of 25 patients with tuberculous pleurisy utilizing enzyme linked immunosorbent assays (EIA). Serum IL-6 levels were only slightly increased in patients with tuberculous pleurisy in comparison to controls (11.1 +/- 2.1 vs 7.3 +/- 1.0 pg ml-1). IL-8 could not be detected in the serum of tuberculosis patients, but it was detected in the serum of healthy controls (8.0 +/- 1.5 pg ml-1). In comparison to serum, IL-6 and IL-8 were found in high concentrations in pleural effusions (IL-6: 932 +/- 70 vs 11.1 +/- 2.1 pg ml-1, P < 0.0001; IL-8: 450 +/- 85 vs 0 +/- 0 pg ml-1). In contrast, sIL-6R concentrations were much higher in serum compared to pleural effusion levels [30,477 +/- 1905 vs 9881 +/- 1177 pg ml-1, P < 0.0001 (mean +/- SEM)]. The authors conclude that elevated levels of IL-6 and IL-8 in pleural effusions are compartmentalized at the site of active disease. The low levels of sIL-6R in the presence of high levels of IL-6 in pleural effusions, and the high levels of sIL-6R in the presence of low levels of IL-6 in serum suggest that the expression or shedding of sIL-6R may be downregulated in the presence of excessive amounts of IL-6.

P-Selectin expression, platelet aggregates, and platelet-derived microparticle formation are increased in peripheral arterial disease.

Platelet volume has been reported to be increased in vascular disease. Therefore, we studied the relationship of mean platelet volume and platelet count as well as flow cytometrically measured platelet size and platelet function in 50 patients with peripheral arterial disease and 50 healthy volunteers. Platelet activation was measured by P-selectin expression analysis on resting and on stimulated platelets, and the determination of platelet aggregates and platelet-derived microparticles using flow cytometry. P-Selectin expression on platelets was significantly elevated in patients suffering from peripheral arterial disease (all P<0.0001). Platelet aggregates (P<0.0001) and platelet-derived microparticles (P<0.0001) were significantly higher in the patient group compared with controls, whereas mean platelet volume and platelet count showed no significant differences. Platelet count was inversely related to mean platelet volume in patients and controls (r = -0.43, P<0.001). The present study supports the hypothesis of platelet hyperreactivity and circulating activated platelets in peripheral arterial disease. Mean platelet volume, and platelet count cannot be used as predictive markers for platelet activation in peripheral arterial disease patients.