[Lambert-Eaton myasthenic syndrome]

INTRODUCTION

Early diagnosis based on clinical findings, neurophysiological studies and serum antibody titres allows early initiation of symptomatic treatment and oncological screening. Reports of patients with LEMS in Latin America are scarce.

AIM

This article aims to describe the characteristics of patients with LEMS from a private centre in Buenos Aires, Argentina, and to compare them with those of other series that have been published.

PATIENTS AND METHODS

The medical records of 13 patients with LEMS with clinical findings, compatible electromyogram and/or positive antibodies were reviewed. Follow-up was performed until associated neoplasia was ruled out or confirmed according to the recommended algorithms.

RESULTS

Four patients were diagnosed with T-LEMS, two of them with small-cell lung carcinoma. Of the nine patients with NT-LEMS, five had a DELTA-P score of 3 and 4. Nine patients presented with the classic clinical triad from the onset of the disease. All patients had electromyogram findings compatible with presynaptic neuromuscular plaque defect. Of the total, 70% improved symptomatically with pyridostigmine.

CONCLUSIONS

The clinical findings, together with compatible neurophysiological studies, are sufficient for the diagnosis of LEMS. The relationship between the DELTA-P score and the risk of small-cell lung carcinoma could not be replicated. Symptomatic treatment with pyridostigmine represents an effective therapeutic alternative.

Vasculitic Peripheral Neuropathy, Differences Between Systemic and Non-Systemic Etiologies: A Case Series and Biopsy Report

BACKGROUND

Vasculitic peripheral neuropathy (VPN) is caused by vessel inflammation leading to peripheral nerve injury of acute-to-subacute onset. When VPN occurs in the context of systemic disease it is classified as Systemic Vasculitic Neuropathy (SVN) and as Non-Systemic Vasculitic Neuropathy (NSVN) when restricted to the nerves.

OBJECTIVE

This study aimed to compare the clinical characteristics, biopsy findings and disease outcome in patients with VPN.

METHODS

Clinical records of adult patients with VPN diagnosed at our institution between June-2002 and June-2019 were retrospectively reviewed. Demographic characteristics, clinical manifestations, nerve conduction studies, nerve biopsies, treatment and clinical evolution were analyzed in all patients with at least 6 months follow-up.

RESULTS

Twenty-five patients with VPN were included (SVN, n = 10; NSVN, n = 15). No significant differences in demographic or clinical features were found between groups. The median delay between symptom onset and nerve biopsy was significantly longer in NSVN patients (10 vs 5.5 months, p = 0.009). Erythrocyte sedimentation rate (ESR) values over 20 mm/h were significantly more common in SVN patients (100% vs. 60%, p = 0.024). Nerve biopsies showed active lesions more frequently in treatment-naive patients compared to those who had received at least 2 weeks of corticosteroids (92% vs 38%; p = 0.03), with a higher proportion of definite VPN cases (92 vs 46%; p = 0.04).

CONCLUSIONS

Although the clinical manifestations are similar, ESR is an important tool to help distinguish between both conditions. Early nerve biopsy in untreated patients increases diagnostic accuracy, avoiding misdiagnosis.

Ultrafine particles in scanning sprays: a standardized examination of five powders used for dental reconstruction

Background

Intraoral matting sprays for chairside systems can release fine or ultrafine particles or nanoparticles at dentists’ workplaces and cause work-related health problems by inhalation exposure. Until now, little is known about the magnitude of the ultrafine fraction, when using these scanning sprays. Hence, more information is needed for workplace risk assessments in dental practices.

Methods

Five commonly used dental spray-powders were examined under standardized conditions. Ingredients were taken from the respective safety data sheet. Particle number-size distributions and total number concentrations were analyzed with a fast mobility particle sizer, and reported graphically as well as mean particle fractions smaller than 100 nm. Based on these measurements, risk assessments were conducted, and particle depositions in the lung were modelled.

Results

The mean fraction of particles smaller than 100 nm varied between 9 and 93% depending on the matting agent and mode of application of the intraoral scanning spray. Propellants can represent a large fraction of these particles. Titanium dioxide, pigment-suspensions, talcum and others particles, which can pose relevant health risks, were listed as ingredients of scanning sprays in safety data sheets. Nevertheless, the deposited fraction of hazardous particles in the lung of employees in dental practices seems to be small (15%) during this dental procedure.

Conclusions

Our results suggest that dentists’ personnel can be exposed to hazardous fine and ultrafine particles. Though extensive standardized measurements and systematic evaluation of safety data sheets were used for this study, they cannot sufficiently assess and categorize potential workplace-related health risks.

Treatment, outcomes and costs of asthma exacerbations in Chilean children: a prospective multicenter observational study

OBJECTIVE

To describe potential regional variations in therapies for severe asthma exacerbations in Chilean children and estimate the associated health expenditures.

METHODS

Observational prospective cohort study in 14 hospitals over a one-year period. Children five years of age or older were eligible for inclusion. Days with oxygen supply and pharmacological treatments received were recorded from the clinical chart. A basic asthma hospitalization basket was defined in order to estimate the average hospitalization cost for a single patient. Six months after discharge, new visits to the Emergency Room (ER), use of systemic corticosteroids and adherence to the controller treatment were evaluated.

RESULTS

396 patients were enrolled. Patients from the public health system and from the north zone received significantly more days of oxygen, systemic corticosteroids and antibiotics. Great heterogeneity in antibiotic use among the participating hospitals was found, from 0 to 92.3% (ICC 0.34, 95% CI 0.16-0.52). The use of aminophylline, magnesium sulfate and ketamine varied from 0 to 36.4% between the different Pediatric Intensive Care Units (ICC 0.353, 95% CI 0.010-0.608). The average cost per inpatient was of $1910 USD. 290 patients (73.2%) completed the follow-up six months after discharge. 76 patients (26.2%) were not receiving any controller treatment and nearly a fourth had new ER visits and use of systemic corticosteroids due to new asthma exacerbations.

CONCLUSIONS

Considerable practice variation in asthma exacerbations treatment was found among the participating hospitals, highlighting the poor outcome of many patients after hospital discharge, with an important health cost.

Hospitalizations for asthma exacerbation in Chilean children: A multicenter observational study

BACKGROUND

Asthma hospitalization rates in Chilean children have increased in the last 14 years, but little is known about the factors associated with this.

OBJECTIVE

Describe clinical characteristics of children hospitalized for asthma exacerbation.

METHODS

Observational prospective cohort study in 14 hospitals. Over a one-year period, children five years of age or older hospitalized with asthma exacerbation were eligible for inclusion. Parents completed an online questionnaire with questions on demographic information, about asthma, indoor environmental contaminant exposure, comorbidities and beliefs about disease and treatment. Disease control was assessed by the Asthma Control Test. Inhalation technique was observed using a checklist.

RESULTS

396 patients were enrolled. 168 children did not have an established diagnosis of asthma. Only 188 used at least one controller treatment at the time of hospitalization. 208 parents said they believed their child had asthma only when they had an exacerbation and 97 correctly identified inhaled corticosteroids as anti-inflammatory treatment. 342 patients used the wrong spacer and 73 correctly performed all steps of the checklist.

CONCLUSIONS

Almost half of the patients were not diagnosed with asthma at the time of hospitalization despite having a medical history suggestive of the disease. In the remaining patients with an established diagnosis of asthma potentially modifiable factors like bad adherence to treatment and poor inhalation technique were found. Implementing a nationwide asthma program including continued medical education for the correct diagnosis and follow up of these patients and asthma education for patients and caregivers is needed to reduce asthma hospitalization rates in Chilean children.

Systemic serum amyloid A as a biomarker for exposure to zinc and/or copper-containing metal fumes

Zinc- and copper-containing welding fumes increase systemic C-reactive protein (CRP). The aim of this study was to investigate the performance of the biomarkers serum amyloid A (SAA) and soluble vascular cell adhesion molecule-1 (VCAM-1) in this regard. Fifteen male subjects were exposed under controlled conditions to welding fumes containing either zinc, or copper, or copper and zinc for 6 h. Plasma samples were collected before, 6 and 24 h after start of exposure and biomarkers therein were measured by electrochemiluminescent assay. For each exposure, systemic concentrations of systemic SAA, but not VCAM-1, increased significantly at 24 h after exposure start compared with baseline ("copper only": P=0.0005, "zinc only": P=0.027, "copper and zinc": P=0.001). SAA showed a wider range of concentrations than did CRP and its levels increased up to 19-fold after welding fume exposure. The recognition of copper as a potential harmful component in welding fumes, also independent from zinc, deserves further consideration. SAA might represent a new sensitive biomarker for potential subclinical sterile inflammation after inhalation of copper- and/or zinc-containing welding fumes. As elevations of CRP and SAA protein have both been linked to a higher risk for cardiovascular disease, these findings might particularly be important for long-term welders.

Biological effects of inhaled nitrogen dioxide in healthy human subjects

PURPOSE

Several epidemiological studies indicate that inhaled nitrogen dioxide (NO2) at low concentrations have been statistically associated with adverse health effects. However, these results are not reflected by exposure studies in humans. The aim of the study was to assess the acute functional and cellular responses to different NO2 concentrations in healthy human subjects with various techniques.

METHODS

Twenty-five subjects were exposed for 3 h to NO2 concentrations 0, 0.1, 0.5, and 1.5 ppm in a randomized crossover study design during 4 consecutive weeks. In each subject, lung function, diffusion capacity and exhaled nitric oxide were measured and inflammation markers were assessed in blood, nasal secretions, induced sputum and exhaled breath condensate.

RESULTS

From all lung function indices under consideration, only intrathoracic gas volume was borderline significantly increased after 0.5 ppm (p = 0.048) compared to 0.1 ppm NO2. Regarding the cellular effect parameters, the macrophage concentration in induced sputum decreased with increasing NO2 concentration, although these changes were only borderline significant (p = 0.05).

CONCLUSION

These results do not suggest a considerable acute adverse response in human subjects after 3 h of exposure to NO2 in the NO2 concentration range investigated in this study.

Assessment of the biological effects of welding fumes emitted from metal inert gas welding processes of aluminium and zinc-plated materials in humans

The aim of this study was to investigate biological effects and potential health risks due to two different metal-inert-gas (MIG) welding fumes (MIG welding of aluminium and MIG soldering of zinc coated steel) in healthy humans. In a threefold cross-over design study 12 male subjects were exposed to three different exposure scenarios. Exposures were performed under controlled conditions in the Aachener Workplace Simulation Laboratory (AWSL). On three different days the subjects were either exposed to filtered ambient air, to welding fumes from MIG welding of aluminium, or to fumes from MIG soldering of zinc coated materials. Exposure was performed for 6 h and the average fume concentration was 2.5 mg m(-3). Before, directly after, 1 day after, and 7 days after exposure spirometric and impulse oscillometric measurements were performed, exhaled breath condensate (EBC) was collected and blood samples were taken and analyzed for inflammatory markers. During MIG welding of aluminium high ozone concentrations (up to 250 μg m(-3)) were observed, whereas ozone was negligible for MIG soldering. For MIG soldering, concentrations of high-sensitivity CRP (hsCRP) and factor VIII were significantly increased but remained mostly within the normal range. The concentration of neutrophils increased in tendency. For MIG welding of aluminium, the lung function showed significant decreases in Peak Expiratory Flow (PEF) and Mean Expiratory Flow at 75% vital capacity (MEF 75) 7 days after exposure. The concentration of ristocetin cofactor was increased. The observed increase of hsCRP during MIG-soldering can be understood as an indicator for asymptomatic systemic inflammation probably due to zinc (zinc concentration 1.5 mg m(-3)). The change in lung function observed after MIG welding of aluminium may be attributed to ozone inhalation, although the late response (7 days after exposure) is surprising.

SIAH ubiquitin ligases target the nonreceptor tyrosine kinase ACK1 for ubiquitinylation and proteasomal degradation

Activated Cdc42-associated kinase 1 (ACK1) is a nonreceptor tyrosine kinase linked to cellular transformation. The aberrant regulation of ACK1 promotes tumor progression and metastasis. Therefore, ACK1 is regarded as a valid target in cancer therapy. Seven in absentia homolog (SIAH) ubiquitin ligases facilitate substrate ubiquitinylation that targets proteins to the proteasomal degradation pathway. Here we report that ACK1 and SIAH1 from Homo sapiens interact in a yeast two-hybrid screen. Protein-protein interaction studies and protein degradation analyses using deletion and point mutants of ACK1 verify that SIAH1 and the related SIAH2 interact with ACK1. The association between SIAHs and ACK1 depends on the integrity of a highly conserved SIAH-binding motif located in the far C-terminus of ACK1. Furthermore, we demonstrate that the interaction of ACK1 with SIAH1 and the induction of proteasomal degradation of ACK1 by SIAH1 are independent of ACK1's kinase activity. Chemical inhibitors blocking proteasomal activity corroborate that SIAH1 and SIAH2 destabilize the ACK1 protein by inducing its proteasomal turnover. This mechanism apparently differs from the lysosomal pathway targeting ACK1 after stimulation with the epidermal growth factor. Our data also show that ACK1, but not ACK1 mutants lacking the SIAH binding motif, has a discernable negative effect on SIAH levels. Additionally, knockdown approaches targeting the SIAH2 mRNA uncover specifically that the induction of SIAH2 expression, by hormonally-induced estrogen receptor (ER) activation, decreases the levels of ACK1 in luminal human breast cancer cells. Collectively, our data provide novel insights into the molecular mechanisms modulating ACK1 and they position SIAH ubiquitin ligases as negative regulators of ACK1 in transformed cells.

Exposure of healthy subjects with emissions from a gas metal arc welding process: part 1--exposure technique and external exposure

BACKGROUND

Studies concerning welding fume-related adverse health effects in welders are hampered by the heterogeneity of workplace situations, resulting in complex and non-standardized exposure conditions.

METHODS

In order to carry out welding fume exposure studies under controlled and standardized conditions, the Aachen Workplace Simulation Laboratory was developed. This laboratory consists of an emission room, in which welding fume is produced, and an exposure room in which human subjects are exposed to these fumes. Both rooms are connected by a ventilation system which allows the welding fume concentration to be regulated. Particle mass concentration was measured with a TEOM microbalance and the particle number-size distribution using a Grimm SMPS device.

RESULTS

In a study, which is the subject of this paper, it has been shown that welding fume concentration can easily be regulated between 1 and about 3 mg m(-3). The chosen concentration can be kept constant for more than 8 h. However, transport of the particles from the emission room into the exposure room leads to a change in particle size distribution, which is probably due to coagulation of the fraction of smallest particles.

CONCLUSION

The Aachen Workplace Simulation Laboratory is suitable for controlled exposure studies with human subjects.

Respiratory medicines for children: current evidence, unlicensed use and research priorities

This European Respiratory Society task force has reviewed the evidence for paediatric medicines in respiratory disease occurring in adults and children. We describe off-licence use, research priorities and ongoing studies. Off-licence and off-label prescribing in children is widespread and potentially harmful. Research areas in asthma include novel formulations and regimens, and individualised prescribing. In cystic fibrosis, future studies will focus on screened infants and robust outcome measures are needed. Other areas include new enzyme and antibiotic formulations and the basic defect. Research into pneumonia should include evaluation of new antibacterials and regimens, rapid diagnostic tests and, in pleural infection, antibiotic penetration, fibrinolytics and surveillance. In uncommon conditions, such as primary ciliary dyskinesia, congenital pulmonary abnormalities or neuromuscular disorders, drugs indicated for other conditions (e.g. dornase alfa) are commonly used and trials are needed. In neuromuscular disorders, the beta-agonists may enhance muscle strength and are in need of evaluation. Studies of antibiotic prophylaxis, immunoglobulin and antifungal drugs are needed in immune deficiency. We hope that this summary of the evidence for respiratory medicines in children, highlighting gaps and research priorities, will be useful for the pharmaceutical industry, the paediatric committee of the European Medicines Agency, academic investigators and the lay public.

PULMONARY DEPOSITION OF MONODISPERSE AEROSOLS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE

In order to improve patient convenience and drug availability for patients with alpha 1-protease inhibitor deficiency, the administration via the inhalation route has been considered. This study investigated if it is possible to obtain high values of peripheral aerosol deposition by using optimized and controlled inhalation conditions. Therefore, peripheral deposition was studied in 10 patients with alpha 1-protease inhibitor deficiency (phenotype PiZ) and moderate to severe chronic obstructive pulmonary disease by measuring the 24-hour Clearance of radiolabeled inert iron oxide particles with diameters of 2 microns, 3 microns, and 4 microns. Patients inhaled a large volume of aerosol (1000 to 2000 cm3), which was normalized to the individual lung function, with a flow rate of 200 cm3/S. Due to this breathing pattern, peripheral deposition was for all particle sizes above 50% of the inhaled aerosol. The highest peripheral deposition (68%) was found for 3-microns particles.

Anticoagulative effects of the inhaled low molecular weight heparin certoparin in healthy subjects

Inhalation of heparin results in local antiinflammatory and antifibrotic effects and an inhibition of blood coagulation. A number of experimental and clinical studies demonstrated that inhalant administration of heparin or low molecular weight heparin (LMWH) is a feasible and save tool for anticoagulative treatment. However, heparin and LMWH differ in respect to their molecular weight, pulmonary absorption, and principle of their anticoagulative pattern. In our study we investigated the anticoagulative effect of different doses of the LMWH certoparin after inhalation (3000 IU-9000 IU) and subcutaneous injection (3000 IU) in healthy individuals in a cross-over design. Inhalations were performed using a new device allowing inhalations with optimized and standardized breathing patterns. The anticoagulative effect was determined by measurement of the anti-factor-Xa (anti-FXa) activity. Lung function parameters were measured before and after drug inhalation. Analysis of the anti-FXa activity as a function of the time after administration revealed values of the area under the curve (AUC) of 5.70+/-1.58 U.hour/ml and 8.43+/-1.31 U.hour/ml (mean+/-SD) with interindividual coefficients of variation of 28% and 13% after injection of 3000 IU and inhalation of 9000 IU, respectively. The AUC after inhalation of 9000 IU was significantly higher (P=0.0007) compared with subcutaneous injection of 3000 IU. In consequence, in order to obtain plasma anti-FXa activities of above 0.2 U/ml, which is considered sufficient for prophylaxis of venous thrombosis, 9000 IU LMWH have to be inhaled. Compared with the subcutaneous administration, the action of certoparin is longer after inhalation than after injection. Apparently, the drug is released rapidly according to a two-compartment kinetics, and its anticoagulant activity lasts over a long time without a marked plasma peak after administration. In detail, an elevation of plasma anti-FXa activity is achieved for 12 hours to 24 hours without a distinct peak shortly after inhalation. Inhalation of LMWH does not result in any changes in lung function or other side effects. The administration of LMWH by inhalation bears the following: the non-invasive route of drug application, the low interindividual variability of the anticoagulative effect, and a long-time pharmacological effect. These properties suggest that controlled inhalation of heparin is an attractive alternative to subcutaneous administration.

Inhalation of tobramycin in patients with cystic fibrosis: comparison of two methods

Inhalant tobramycin is established in the treatment of cystic fibrosis patients. Conventional nebulizers require a large amount of the expensive compound, because only a small fraction is deposited in the targeted lung region. In contrast, techniques based on controlled inhalation allow a high and reproducible deposition of the drug in specific lung regions. In our study we compared the efficiency of two techniques based on conventional and controlled inhalation in 16 cystic fibrosis patients aged 13-39 years. Inhalations with the doses of tobramycin of 300 mg and 150 mg were performed twice daily for three days. The efficiency of the drug deposition was measured by the determination of its serum concentration 1 h after the end of the inhalation. The mean FEV1 value in our patients was 61% of predicted, range 36%-116%. There were no differences in tobramycin serum concentrations among the three study days in both methods (controlled inhalation: 0.983 +/-0.381(+/-SD) mg/l, 1.119+/-0.448 mg/l, 1.194+/-0.568 mg/l; conventional inhalation: 1.075+/-0.798 mg/l, 1.294 0.839 mg/l and 1.269+/-0.767 mg/l, on Day 1, Day 2, and Day 3, respectively). Even though the drug amount was double in the conventional technique, there was no significant difference in its overall serum concentration from the three study days (conventional inhalation: 1.210+/-0.783 mg/l, controlled inhalation: 1.092+/-0.461 mg/l). In addition, the coefficient of variation and the required inhalation time were shorter in controlled inhalation than in conventional inhalation (42% vs. 65% and 7-8 min vs. 20 min, respectively). Our data suggest that controlled inhalation can significantly reduce the amount of a drug required for therapy, the inhalation time required for drug deposition, and the variability of pulmonary dosage. It seems probable that controlled inhalation can improve the antibiotic prevention of pulmonary infection.

Aerosol-derived airway morphometry (ADAM) in patients with lung emphysema diagnosed by computed tomography--reproducibility, diagnostic information and modelling

Gravitational deposition of monodisperse particles can be used to determine effective airway diameter (EAD). The aim of our study was to assess intraindividual variability of EAD in healthy subjects and patients with emphysema, to compare EAD in patients with different degree and type of emphysema, and to evaluate whether parametric or model analysis would improve the results. EAD was measured vs volumetric lung depth (LD) in 11 healthy subjects (FEV subset1 107%pred) and 41 patients with emphysema (FEV subset1 60%pred; 8/9/24 mild/moderate/severe, 18/7/16 centriacinar/panacinar/bullous according to HRCT). Repeated measurements in LDs of 6-30% showed coefficients of variation of 7.0-10.4% in healthy subjects and 8.3-11.9% in emphysema. Average EAD in 10-16% LD was increased in emphysema, in particular moderate and severe (p<0.05, each). The slope of EAD in 10-16% LD differed between healthy subjects and emphysema, especially bullous and centriacinar. Patients with severe emphysema also showed a different slope compared to mild emphysema and controls. The parameters of the power function used for data fitting also showed differences between controls and emphysema, as well as between centriacinar vs panacinar and bullous emphysema. In a three-compartment lung model only the diameter of the intermediate compartment was enlarged in emphysema. We conclude that in using aerosol-derived airway morphometry, reproducibility of repeated measurements is acceptable. Average values and slopes of the EAD curve, as well as a power function for data fitting, were sensitive in the detection of type and severity of emphysema. In contrast, application of a lung model did not improve the results.

Vergleich der unspezifischen bronchialen Provokation mit Methacholin unter kontrollierter und freier Inhalation

Using controlled breathing patterns during inhalation of drugs is characterized by a high dose reproducibility which may be of advantage for bronchial provocation testing. In this study 30 healthy subjects with an anamnesis of atopy underwent in a randomized cross-over design bronchial provocation testing with methacholine either with the Viasys-Jäger-APS system or with controlled inhalations (AKITA-System) (controlled inhalation volume and flow). Measured was the frequency of positive test results. Positive test results were defined by a 20 % decline of FEV (1) or a 100 % increase of specific airway resistance (sRaw). There were no significant differences in the prevalence of positive test results obtained with both techniques: APS-FEV (1) : 8, AKITA-FEV (1) : 9; APS-sRaw: 18, AKITA-sRaw: 17. More subjects showed a 100 % increase of sRaw as compared to a 20 % decrease of FEV (1), which may be interesting in order to understand differences in the diagnostic information given by both parameters. However, there were some discrepancies: only in 25 of 30 cases (sRaw: 21 of 30 cases) the results (positive or negative) agreed between both techniques. Although the two techniques for bronchial provocation test showed some discrepancies, these data suggest that controlled inhalations may be an alternative to the APS-system.

Pharmacokinetic of inhaled low molecular weight heparin

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Background: Treatment with Heparin and low molecular weight (LMW) Heparin is frequently used in oncology settings. Usually, these drugs are delivered by subcutaneous (s.c.) administration. Since 1963, the clinical relevance of inhalation of unfractionated as well as LMW-Heparin has been investigated in various studies with over 500 subjects. In this study, a single inhalation of the LMW-Heparin Certoparin (Mono-Embolex, Novartis) was investigated in 10 healthy subjects. The goal was to assess the pharmacokinetic behavior. Inhalations were performed using a novel inhalation system, which allows an accurate dosing in the lungs by controlling patient’s breathing pattern (AKITA). Lung deposition is about 85% of the emitted dose. Methods: 10 non-smoking healthy subjects participated in this study. Inhalation of 9000 IU of LMW-Heparin was compared to 3000 IU s.c. administration to achieve factor-Xa-activity in the plasma of 0.2 to 0.3 U/ml. Intravenous blood samples were taken 0.25, 0.5, 1, 2, 4, 6, 24, 48 hrs after administration. Factor-Xa-activity in plasma was assessed using the Berichrom assay (Dade Behring, Marburg, Germany). Results: Inhalation of LMW-Heparin was well tolerated and did not result in any side effects or changes in lung function. The maximum anti-Xa-activity in the plasma was 0.3 U/ml for the s.c. administration of Certoparin and 0.32 U/ml after inhalation of 9000 IU. However, pharmacokinetics was considerably different. Inhaled LMW-Heparin resulted in a prolonged anti-Xa-activity. After 6 (24) hours, the anti-Xa-activity after s.c. administration was down at 0.16 U/ml (0.10) and after inhalation at 0.30 (0.18) U/ml. Even after 48 hrs, the anti-Xa-activity after inhalation was significantly higher than the baseline value. Comparing area under the curve (AUC), bioavailability for the inhalation was 9.4 U · h/ml ± 14% compared to 5.7 U · h/ml ± 27% after s.c. administration. Conclusions: These results suggest that with controlled inhalation, this administration route is an attractive alternative to s.c. administration, with the result of longer bioavailability and less variability. A once daily administration is possible. Inhalation therapy with these kind of systems might also be useful with different anticancer agents, which cannot be administered orally.

[Table: see text]

[Six-minute-walking-test with and without oxygen in patients with COPD: comparison of walking distance and oxygen saturation in varying forms of application]

BACKGROUND

Patients afflicted with COPD and respiratory Failure often experience a decrease of oxygen saturation (SaO (2)) under physical strain. The aim of our study was to find out which changes occur in walking distance and SaO (2) under the application of Oxygen (O (2)) 2 l/min continous flow, under demand (D) and under normal air (RL) when performing the Six-Minute-Walking-Test (6MWT) and further, in which way do the 10 patients of the shortest walking distance group (group I) differ from the eo patients with the longest walking distance (group II) concerning the starter 6 MWT (under CF).

METHOD AND PATIENTS

27 patients undertook a 6MWT three days in a row with CF, D and (RL), 6 minutes before (phase I), during (phase II) and after (phase III) the 6MWT oxygen was applied in CF (day I), D (day II) and RL (day III), the mean oxygen saturation in each phase was measured and the change (DeltaSaO (2)) during and after the 6MWT was calculated. Additionally we measured the DeltaSaO (2) between start and middle, as well as between middle and end of each phase. In close proximity to the tests FEV (1) and pO (2) was determined.

RESULTS

In the total of all test persons there was no significant difference in the walking distance tetween the 3 forms of application. There was, however, a highly significant decrease of the oxygen saturation. The decrease in the two forms of oxygen application did not differ significantly. The decrease of SaO (2) under strain and the consecutive rise under rest occurred within the first 3 minutes of each phase. Patients of group II were often able to increase their walking distance under RL, whereas patients of group I decreased their walking distance further. In group II FEV (1) abs. was significantly higher, but FEV (1) % debit and pO (2) did not differ significantly between both groups.

CONCLUSIONS

Patients with a long walking distance showed a marked learning effect even under RL, they presented a higher FEV (1), but not an increased pO (2). The phase of resaturation after the end of strain is short. Oxygen application through a demand valve with a flow rate of 2 l/min is not inferior to a continuous flow. In more than half of all patients the SaO (2) fell below 90 % under both forms of oxygen application, in conclusion the flow rate should be increased in these cases.

Optimum peripheral drug deposition in patients with cystic fibrosis

In order to identify the optimum particle size and breathing pattern for high peripheral deposition of inhaled drugs in patients with cystic fibrosis, regional deposition in these patients was studied systematically as a function of particle size, inhalation volume and flow rate. Regional deposition was assessed using the single-breath regional deposition technique in which the concentration profile of inhaled and exhaled non-radioactive, monodisperse test particles is analyzed. Using this technique particle deposition within the functional dead space volume and peripherally can be assessed. Regional deposition was measured in 12 patients with cystic fibrosis using 2, 3, 4, and 5.5 microm particles, inhalation volumes of 500, 1000, 1500, and 2000 cm(3), and inhalation flow rates of 100, 250, 500, and 750 cm(3)/sec. Peripheral deposition was highest when 2-3-microm particles were inhaled with air-flow rates of 250-500 cm(3)/sec. With these parameters peripheral deposition increased with increasing inhalation volume and reached values of about 60% of the total drug inhaled. It has been shown that high peripheral drug deposition can be achieved in patients with CF when inhalations are performed using an optimized combination of particle size and breathing pattern.

Quantitative computed tomography and aerosol morphometry in COPD and alpha1-antitrypsin deficiency

Relative area of emphysema below -910 Hounsfield units (RA-910) and 15th percentile density (PD15) are quantitative computed tomography (CT) parameters used in the diagnosis of emphysema. New concepts for noninvasive diagnosis of emphysema are aerosol-derived airway morphometry, which measures effective airspace dimensions (EAD) and aerosol bolus dispersion (ABD). Quantitative CT, ABD and EAD were compared in 20 smokers with chronic obstructive pulmonary disease (COPD) and 22 patients with alpha1-antitrypsin deficiency (AAD) with a similar degree of airway obstruction and reduced diffusion capacity. In both groups, there was a significant correlation between RA-910 and PD15 and pulmonary function tests (PFTs). A significant correlation was also found between EAD, RA-910 and PD15 in the study population as a whole. Upon separation into two groups, the significance disappeared for the smokers with COPD and strengthened for those with AAD, where EAD correlated significantly with RA-910 and PD15. ABD was similar in the two groups and did not correlate with PFT and quantitative CT in either group. In conclusion, based on quantitative computed tomography and aerosol-derived airway morphometry, emphysema was significantly more severe in patients with alpha1-antitrypsin deficiency compared with patients with usual emphysema, despite similar measures of pulmonary function tests.