Biomedical subjects

R Siekmeier

Publications and source records attributed to R Siekmeier.

At least 19 recordsLinked to original sources

PubMed2006

[Can antioxidants prevent atherosclerosis?].

In vitro studies have shown that antioxidants (e. g. beta-carotene, vitamin C and vitamin E) can interfere with some pathomechanisms of atherosclerosis and therefore might have a protective effect. From the investigated antioxidants vitamin E showed the best effect. Some animal and epidemiological studies confirmed such a protective effect in vivo especially after administration of high doses of vitamin E. However, most of the placebo-controlled studies for primary or secondary prevention failed to show a protective effect even after administration of high doses. In addition, other studies demonstrated a risk for adverse effects due to antioxidant supplementation (beta-carotene and vitamin E). Our review summarises the principle of antioxidant supplementation and a number of relevant epidemiological and clinical studies for prevention of atherosclerosis. The obtained results suggest that supplementation of antioxidants cannot be recommended for the normal population.

Adult↗

PubMed2006

[Are blood glucose analyzers safe? Experiences of the BfArM based on all notifications received until end of 2005].

Since implementation of the Directive 98/79/EC of the European Parliament and of the Council on in vitro Diagnostic Medical Devices (IVD Directive), issues and field corrective actions on in vitro diagnostic medical devices (IVDMD) have to be reported to the national competent authorities. In Germany these are the BfArM and the Paul Ehrlich Institute; the latter is responsible for Annex II products used for immune hematology, tissue typing and infectiology testing. Between the beginning of 1999 and the end of 2005 BfArM received n=653 notifications on IVDMD. From these n=128 concerned analyzers and sensors (test strips) for self monitoring of blood glucose. A similar quantity of cases was reported by users and manufacturers (44.5%). In n=31 of these cases a product defect was not confirmed after the investigation of the products by the manufacturers. Product failures were confirmed in n=35 cases. The remaining cases were caused by user errors (n=29) or the data were inconclusive (n=33), predominantly because the products were not or only partly available for investigation by the manufacturers. In those cases where product failure had been verified n=24 affected the sensors (test strips) and n=11 the analyzers. Corrective actions were performed by the manufacturers in n=34 cases. From these n=27 were cases in which a product failure had been detected. However, in n=7 cases the investigations of the manufacturers were followed by preventive corrective actions because the manufacturers became aware of potential causes of future product failures. The obtained results and experiences since 1999 show that the governmental system for post-marketing surveillance of products for self testing of blood glucose is an established tool to ensure product safety. Regarding the proportion of notifications concerning these over the counter (OTC) products, it becomes obvious that they are a focus for action for the competent surveillance authorities.

Blood Glucose Self-Monitoring↗

PubMed2002

Pharmacokinetics of pravastatin in heart-transplant patients taking cyclosporin A.

BACKGROUND: Heart transplantation is an established tool for the treatment of terminal heart failure. Hyperlipidemia is a common problem following heart transplantation and has been implicated as an additional risk factor in the development of transplant coronary artery disease (TxCAD). Therefore, heart recipients are commonly treated with inhibitors of cholesterol synthesis (HMG-CoA reductase inhibitors). However, these patients have an increased risk of developing rhabdomyolysis due to elevated concentrations of HMG-CoA reductase inhibitors under co-administration with the immunosuppressive cyclosporin A (CsA). AIM OF THE STUDY: Aim of our study was to obtain pharmacokinetic data on pravastatin whilst monitoring the safety and efficiency of the lipid lowering therapy in heart-transplant recipients under immunosuppression with CsA and to compare these data to those of a healthy control group. SUBJECTS, MATERIALS AND METHODS: Eleven patients (30.2 +/- 12.3 months after transplantation) receiving immunosuppressive therapy consisting of cyclosporin A, prednisone and azathioprine with LDL cholesterol (LDL-C) concentrations exceeding 3.9 mmol/l and 8 control subjects were included into the study. In addition to the immunosuppressive therapy, the patients received a daily dose of 40 mg/day pravastatin for the first 8 days which was then reduced to 10 mg/day administered until Day 29. Blood was sampled for pharmacokinetic profiling (maximum concentration of the drug (Cmax), time to reach Cmax (tmax), area under the concentration vs. time curve (AUC(0-24h)), elimination half-life time (tcl)) and measurement of the parameters of clinical chemistry on Days 1, 8 and 29. The control group received a single dose of 60 mg pravastatin and the values of Cmax and AUC(0-24h) were normalized for a dose of 10 mg. RESULTS: Pravastatin 40 mg/day for 1 week in the patient group caused a significant reduction in total cholesterol (C) and LDL-C from 8.11 +/- 1.20 mmol/l and 5.88 +/- 1.15 mmol/l to 6.91 +/- 1.01 mmol/l and 4.72 +/- 1.05 mmol/l, respectively (p = 0.005 and p = 0.003). Triglycerides and HDL cholesterol (HDL-C) concentrations did not change significantly. Mean values for Cmax of pravastatin were 384.2 ng/ml, 392.0 ng/ml and 115.1 ng/ml in patients on Days 1, 8 and 29, respectively. After normalization for a dose of 10 mg, the corresponding values of C(max-DN10mg) and Cmax were 96.0 ng/ml, 98.0 ng/ml and 115.1 ng/ml on study Days 1, 8 and 29. These values were 7-8 times higher than the normalized value of C(max-DN10mg) for the control group (13.7 ng/ml). The corresponding values of AUC(0-24h) were 1228.2 ng/ml x h, 1214.1 ng/ml x h and 345.9 ng/ml x h in the patient group on study Days 1, 8 and 29 as well as 157.5 ng/ml x h in the control group prior to normalization. After normalization for a dose of 10 mg, the values of AUC(0-24h-DN10mg) in the patient group were approximately 12 times higher than those of the control group. However, no significant differences between the 2 groups were observed in tmax and tcl. Within the patient group, no significant increase in Cmax or AUC was found on Day 1 to Day 8. The results of creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) showed also no significant increase during the observation period. CONCLUSION: Heart-transplant recipients treated with the HMG-CoA reductase inhibitor pravastatin generally show higher plasma concentrations of this drug than control subjects. However, our data suggest that the HMG-CoA reductase inhibitor pravastatin can be used effectively in these patients receiving the immunosuppressive cyclosporin A. The pharmacokinetic data obtained indicate that there is no significant cumulation of the drug following multiple dosages in spite of increased drug concentrations after a single oral dosage.

Anticholesteremic Agents↗

PubMed2001

Dose dependency of fluvastatin pharmacokinetics in serum determined by reversed phase HPLC.

BACKGROUND: Fluvastatin is an inhibitor of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, effectively lowering serum cholesterol concentrations. A high-performance liquid chromatography (HPLC) assay was developed that determined the pharmacokinetics of fluvastatin in healthy individuals after administration of 40 and 80 mg fluvastatin. METHODS: The method was linear for serum concentrations between 10 ng/mL and 5,000 ng/mL, showing good coefficients of variations and sample stability. After administration of 40 mg fluvastatin, the mean values of the area under the serum concentration vs time curve (AUC), the maximum serum drug concentration (C(max)), the time to reach C(max) (t(max)), and the serum elimination half-life time were 528.5 +/-358.8 ng/mL x h, 149.6 +/-56.0 ng/mL, 60.0 +/-30.0 minutes, and 108.0 +/-67.9 minutes, respectively. The corresponding values for a dose of 80 mg fluvastatin were 1417.7 +/-879.2 ng/mL x h, 1024.7 +/-1085.1 ng/mL, 60.0 +/-21.2 minutes, and 106.0 +/-73.6 minutes, respectively. Doubling of the dose from 40 mg to 80 mg caused an overproportional increase of AUC and C(max). RESULTS AND CONCLUSION: Results suggest that the measurement of fluvastatin serum concentrations by means of HPLC provides reliable data within the broad range of physiological serum concentrations. The pharmacokinetic data after administration of high doses (80 mg) showed an overproportional increase of AUC and C(max), suggesting a saturation of the hepatic first-pass effect. Thus, in patients treated with additional substances interfering with fluvastatin metabolism, fluvastatin serum concentrations should be analyzed.

Administration, Oral↗

PubMed2001

Pharmacokinetics and pharmacodynamics of fluvastatin in heart transplant recipients taking cyclosporine A.

During the last decades, transplantation has become an established tool for the treatment of terminal organ failure. Beside immunological factors, hyperlipidemia is the main problem after heart transplantation, causing rapid transplant coronary artery disease (TxCAD) and poor long-term prognosis at the beginning of the transplantation. Heart transplant recipients are now effectively treated with lipid lowering substances, of which HMG-CoA-reductase inhibitors are the most potent. However, treatment with these substances correlates with an increased risk for the development of rhabdomyolysis due to therapy with the immunosuppressive cyclosporine A. Our study monitored the safety and efficacy of treatment with the HMG-CoA reductase inhibitor fluvastatin in heart transplant recipients compared to healthy controls. We investigated 10 patients receiving immunosuppressive therapy consisting of cyclosporine A, prednisone, and azathioprine who had increased concentrations of LDL-cholesterol (LDL-C), and 10 age-matched healthy controls. The patients were treated with 40 mg/day fluvastatin for 4 weeks and 20 mg/day for 4 additional weeks. Control individuals received 40 mg/day fluvastatin for 4 weeks only. Parameters of fluvastatin pharmacokinetics (maximum concentration of the drug (C(max.)), time (t(max.)) to reach C(max.), area under the concentration vs. time curve (AUC(0h-24h)), elimination half-life time (t(1/2))), apparent total body clearance (CL), blood cyclosporine A concentration, plasma lipids, and safety parameters were determined in both study groups at the beginning of the study and after 4 weeks. The latter were determined in the patient group also after 8 and 12 weeks. Treatment with 40 mg/day fluvastatin caused a significant decrease in total cholesterol (patients: 5.47 +/- 1.32 mmol/L vs. 7.30 +/- 1.83 mmol/L; controls: 4.69 +/- 0.64 mmol/L vs. 5.81 +/- 0.72 mmol/L), LDL-C (patients: 3.28 +/- 1.25 mmol/L vs. 5.00 +/- 1.85 mmol/L; controls: 2.58 +/- 0.63 mmol/L vs. 3.50 +/- 0.70 mmol/L), and triglycerides (patients: 1.99 +/- 0.77 mmol/L vs. 2.50 +/- 1.00 mmol/L; controls: 1.24 +/- 0.46 mmol/L vs. 1.72 +/- 0.67 mmol/L) in both study groups, whereas HDL-C was not significantly changed (patients: 1.29 +/- 0.35 mmol/L vs. 1.17 +/- 0.32 mmol/L; controls: 1.55 +/- 0.30 mmol/L vs. 1.53 +/- 0.26 mmol/L). Values of C(max.) and AUC(0h-24h) were higher in the patient group than in the control group (day 1, patients vs. controls, C(max.): 869.4 +/- 604.0 ng/mL vs. 211.9 +/- 113.9 ng/mL; AUC(0h-24h): 1948.8 +/- 1347.9 ng/mL*h vs. 549.4 +/- 247.4 ng/mL*h), whereas the corresponding value of CL was lower in the patient group (33.3 +/- 24.5 L/h vs. 107.9 +/- 95.8 L/h), and the values of t(max.) and t(1/2) showed no differences. In addition, values of C(max.) and AUC(0h-24h) after administration of 40 mg/day fluvastatin for 4 weeks in both groups were slightly higher than at the beginning, whereas the value of CL was slightly lower (day 28, patients vs. controls, C(max.): 1530.4 +/- 960.4 ng/mL vs. 254.7 +/- 199.8 ng/mL; AUC(0h-24h): 2615.3 +/- 1379.4 ng/mL*h vs. 841.8 +/- 421.4 ng/mL*h; CL: day 28, 21.4 +/- 15.3 L/h vs. 61.5 +/- 36.6 L/h). Except for an intermittent increase of creatine kinase, safety parameters showed no increases within the observation period. Our data suggest that fluvastatin effectively lowers plasma concentrations of cholesterol and LDL-C in patients after heart transplantation, however, the metabolism of fluvastatin is affected by concomitant therapy with cyclosporine A. Serum concentrations of fluvastatin should be monitored in cases of concomitant therapy with other substances interfering in the metabolism by competing cytochrome enzymes.

Adult↗

PubMed2001

The white blood cell differential: three methods compared.

The analysis of the automated blood cell count is an essential tool in haematological diagnostics. However, in the case of the white blood cell differential the microscopy method, although tedious, often serves as reference. We evaluated the ABX Pentra 120 Retic haematology analyser in comparison to the Coulter STKS haematology system and the microscopy method with respect to accuracy, precision and reliability. We compared 308 samples (239 samples from adults and 69 from children) including patients with oncological diseases. The comparison of the white blood cell differential revealed strong correlations between the results obtained with the ABX Pentra 120 Retic and the microscopy method, the Coulter STKS and the microscopy method and both automated methods (values of paediatric samples in parentheses; neutrophils: rs > or = 0.933 (rs > or = 0.951), lymphocytes: rs > or = 0.907 (rs > or = 0.945), monocytes: rs > or = 0.584 (rs > or = 0.459) and eosinophils: rs > or = 0.963 (rs > or = 0.966)). The analytical performance of automatic analysers for the detection of the morphological "left shift" was determined for all samples in comparison to the microscopical white blood cell differential. The sensitivity, specificity and efficiency depended strongly on the chosen threshold levels and were different for both analysers. The sensitivity for flagging a left shift increased with an increasing proportion of neutrophil bands, metamyelocytes, myelocytes and promyelocytes. Our study suggests that the ABX Pentra 120 Retic haematology analyser, as well as the Coulter STKS haematology system are useful tools for routine analysis in haematology.

Adult↗

PubMed2000

Effects of lovastatin and pravastatin on the survival of hamsters with inherited cardiomyopathy.

Cardiomyopathic hamsters develop heart disease early in life, which leads to congestive heart failure and death as these hamsters age. Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been reported to reduce ubiquinone concentrations and to deteriorate myocardial function in humans and in experimental animals. HMG-CoA reductase inhibitors differ regarding their ability to penetrate extrahepatic tissues. As a consequence, lovastatin inhibits cholesterol biosynthesis at least 100-fold more effectively than pravastatin in extrahepatic cells. We examined the effect of lovastatin and pravastatin (approximately 10 mg per kilogram of body weight and per day mixed in the diet) compared with controls on the lifespan of cardiomyopathic hamsters (BIO 8262 strain) in the heart-failure period. In male hamsters, neither lovastatin nor pravastatin significantly affected survival. In female hamsters, lovastatin reduced median survival time from 89 days (control animals) to 30 days (P <.05); pravastatin (median survival, 115 days) had no statistically significant effect. We conclude that lovastatin, but not pravastatin, at a daily dose of 10 mg per kilogram of body weight significantly increases the mortality of cardiomyopathic hamsters. This effect may be the result of inhibition of myocardial ubiquinone supply.

Administration, Oral↗

PubMed2000

Determination of reticulocytes: three methods compared.

Determination of reticulocytes in peripheral blood is a valuable tool for getting information about erythropoiesis of an individual. For many years, reticulocyte numbers were quantified manually by means of a microscope after staining with supravital dyes. However, this method is tedious and shows low reproducibility. Therefore, several methods for the automated determination of reticulocytes have been established in laboratory routine within the last years. The aim of this study was to compare three of these automated methods for reticulocyte analysis. Reticulocytes were determined in 130 subsequent routine samples by means of an ABX Pentra 120 Retic haematological analyser, a Coulter EPICS XL MCL flow cytometer and a Coulter STKS haematology system, using the fluorescent dye thiazole orange or the supravital dye new methylene blue for reticulocyte staining, respectively. The reticulocyte concentrations were slightly lower for the Coulter STKS haematology system (mean +/- SD 1.89+/-1.32%) when compared with the Coulter EPICS XL MCL flow cytometer or the ABX Pentra 120 Retic haematological analyser (2.11+/-1.25% and 2.12+/-1.15%, respectively). The correlations between all methods were significant (r(s) > or = 0.843, p < 0.001). Small intercepts were, however, observed in the correlation plots between the values obtained by means of the Coulter STKS haematology system and those obtained by the other two methods. Within-batch coefficients of variation were 6.0%, 6.9% and 7.8% for the ABX Pentra 120 Retic haematological analyser, the Coulter STKS haematology system and the Coulter EPICS XL MCL flow cytometer, respectively. The corresponding between-batch coefficient of variation values were 6.8%, 4.9% and 5.3% as well as 14.1%, 7.6% and 6.1% for the low, medium and high control levels determined by means of the ABX Pentra 120 Retic haematological analyser and the Coulter STKS haematology system, respectively. These data suggest that all three methods allow the efficient and reliable determination of reticulocyte counts under clinical routine conditions. However, although the obtained data are very similar, differences exist which should be taken into account for the normal values of the different methods.

Automation↗

PubMed2000

Determination of pravastatin by high performance liquid chromatography.

BACKGROUND: Pravastatin is a hydrophilic liver-specific inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase. It effectively lowers plasma cholesterol and low-density lipoprotein concentrations in humans. Pharmacokinetic studies of pravastatin have been mostly performed by means of radioactively labelled drug or by measuring plasma concentrations with gas chromatography and mass spectrometry. AIMS OF THE STUDY: Aim of our study was to develop a simple, but reliable method which allows the determination of pravastatin plasma concentrations under clinical routine conditions. SUBJECTS, MATERIALS AND METHODS: Samples were prepared by solid-phase extraction on cyclohexyl bond elut cartridges. Chromatography was carried out on an octyl matrix. Triamcinolone acetonide was used as internal standard. The method was linear within the range of 5 to 200 microg/l pravastatin. The coefficient of variation depended on the pravastatin concentration, but was less than 10% throughout. The pharmacokinetics of pravastatin were determined in healthy individuals. Five healthy subjects received single oral doses of pravastatin (60 mg) and one of these subjects additionally received a dose of 80 mg at three different study days. In all subjects blood was sampled 0, 30, 60, 90, 120, 150, 180, 240 and 300 min after drug intake. RESULTS: Peak plasma concentrations of pravastatin were found between 60 min and 120 min after oral administration of 60 mg and reached values between 37 microg/l and 126 microg/l. The calculated AUCs were between 52 ng/ml x h and 311 ng/ml x h and the corresponding plasma elimination half-life times were between 95 min and 165 min. In all subjects plasma concentrations of pravastatin 5 hours after oral drug administration were near the detection limit of the method (5 microg/l). Intraindividually, there was only little variation in the kinetics of pravastatin. However, marked differences were encountered between the subjects studied. CONCLUSION: The data suggest that the determination of pravastatin plasma concentrations by means of a HPLC system can be used for routine analysis of pravastatin plasma concentrations. The obtained pharmacokinetic data in healthy individuals stand in ample agreement with the results of prior studies in which the concentrations of pravastatin were determined by other more sophisticated methods.

Area Under Curve↗

PubMed1998

Even moderate cigarette smoking influences the pattern of circulating monocytes and the concentration of sICAM-1.

The pattern of circulating monocyte subtypes and the concentration of the soluble intercellular adhesion molecule-1 (ICAM-1) were compared in middle-aged female moderate smokers and lifetime non-smokers. Total leukocyte and monocyte counts were higher in smokers. The pattern of circulating monocytes of smokers was changed toward lower absolute counts of activated (CD16+/CD64+) monocytes and (CD16+/CD14+) monocyte-macrophages and higher counts of nonactivated monocytes. The serum concentration of soluble ICAM-1 was significantly higher in smokers than in non-smokers. It is supposed that even moderate cigarette smoking leads to an activation of the circulating monocytes and their increased adhesion to the endothelium.

Antigens, CD↗

PubMed1998

Food supply abundant increase of serum selenium concentrations in middle-aged Dresden women between 1990 and 1996. DRECAN-Team. Dresden Cardiovascular Risk and Nutrition.

Serum selenium concentration was measured in middle-aged Dresden (East Germany) women in 1990 and 1996. In 1990, the serum concentration of selenium in middle-aged women was higher than in men living under the same environmental conditions (0.98 +/- 0.32 vs 0.82 +/- 0.19 micromol/l). In 1996, the serum concentration of selenium in middle-aged women was significantly higher than in 1990 (1.19 +/- 0.34 micromol/l). This increase seems to be caused by the changed foodstuff supply after the reunification of Germany. Selenium values did not correlate with age, blood pressure or daily energy intake. Moderate smoking and menopausal status did not influence the selenium levels. In 1990, the serum concentration of selenium was the highest in those women who consumed the lowest amounts of carbohydrates or fibers, or who had the highest consumption of meat, fresh fish or potatoes.

Adult↗

PubMed1998

Convective gas mixing, airway dimensions and lung function parameters in patients homo- or heterozygote for hereditary alpha1-antitrypsin deficiency.

Informations about convective gas transport and airway morphometry as a function of volumetric lung depth (V(LD)) can be evaluated by means of two methods based on aerosol inhalation and determination of aerosol pulse parameters (APP) and effective airway dimensions (EAD). APP, EAD and conventional pulmonary function tests (PFT) were measured in patients homo- and heterozygote for alpha1-antitrypsin (alpha1-AT) deficiency. Thirteen homozygote subjects (ZZ allele), 21 heterozygote subjects (MZ allele) and 20 healthy controls were included. Anthropometric data were similar in all groups. APP but not PFT and EAD showed slight significant differences between controls and heterozygotes. However, PFT, APP and EAD from ZZ-homozygotes were strongly different from those of the other groups. Differences were also observed for APP between control smokers and nonsmokers and for APP, PFT and EAD between control nonsmokers and heterozygote smokers but not between heterozygote smokers and heterozygote nonsmokers and control nonsmokers and heterozygote nonsmokers, respectively. The data suggest that lung emphysema causes variations of pulmonary convective gas mixing detectable by measurement of APP which obviously precede variations of PFT. Our data further suggest that heterozygotes are not automatically at risk for the development of lung emphysema. Therefore we also regarded the results with request to individual smoking habits and found an increased risk in heterozygote smokers when compared to control nonsmokers.

Adult↗

PubMed1996

Deletion polymorphism of the angiotensin I-converting enzyme gene is associated with increased plasma angiotensin-converting enzyme activity but not with increased risk for myocardial infarction and coronary artery disease.

BACKGROUND: Previous research has shown that the insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme (ACE) gene is a major determinant of plasma ACE activity. It has been suggested that persons with the DD genotype (those who express, on average, the highest levels of circulating ACE) have an increased risk for myocardial infarction and coronary artery disease, particularly if they are otherwise at low risk. Subsequent studies, however, have not confirmed that ACE I/D gene polymorphism is a risk factor for coronary artery disease and myocardial infarction. OBJECTIVE: To investigate the association between the I/D polymorphism of the ACE gene and the risk for coronary artery disease and myocardial infarction in patients in whom coronary artery disease status was documented by angiography. DESIGN: Cross-sectional study. SETTING: University medical center. PATIENTS: 209 male case-patients with coronary artery disease and 92 male controls without coronary artery disease, as documented by coronary angiography. MEASUREMENTS: Assessment of the cardiac risk profile by questionnaire; classification of patients by the degree of coronary artery stenosis; levels of lipoproteins, apolipoproteins, and fibrinogen; and ACE I/D gene polymorphism assessed by polymerase chain reaction amplification. RESULTS: Plasma ACE activity was significantly associated with ACE I/D gene polymorphism. The ACE genotype was not associated with the presence of coronary artery disease or myocardial infarction. If a recessive effect of the D allele was assumed (DD compared with DI and II), the relative risk was 1.00 (95% CI, 0.76 to 1.30) for coronary artery disease and 1.03 (CI, 0.77 to 1.38) for myocardial infarction. Results of analyses were also negative when a dominant effect of the D allele was assumed and when low-risk subgroups were examined. The established risk factors age and apolipoprotein B level emerged as the most important risk predictors in multivariate analyses, followed by diastolic blood pressure and fasting glucose levels. CONCLUSIONS: In an angiographically defined study sample, ACE I/D gene polymorphism was not associated with an increased risk for coronary artery disease or myocardial infarction, despite its effects on plasma ACE activity.

Aged↗

PubMed1996

Smoking impairs alveolar macrophage activation after inert dust exposure.

Magnetopneumography was applied to investigate intracellular phagosome motion in alveolar macrophage cells of healthy subjects (non-smokers and smokers). Ingested magnetic microparticles are inhaled and phagocytized by alveolar macrophages within hours. Thereby the particles are transferred into phagolysosomes. After magnetization the particles produce a macroscopic magnetic field of the lungs. Cellular motility causes a decay of the field (relaxation) by stochastic disorientation of the dipole particles (phagolysosomes) in the cells. Our studies have shown that the deposition of magnetite test particles induces a non-specific activation of the macrophage cells with a faster relaxation. This activation vanishes within the first day after particle deposition. This macrophage activation due to dust exposure was not present in smokers. It follows that cigarette smoking either causes a damage of the cellular defense or causes an adaptation of the macrophage cells to the permanent cigarette smoke inhalation.

Administration, Inhalation↗

PubMed1996

Deposition of inspired aerosol particles within the respiratory tract of patients with obstructive lung disease.

Total deposition of monodisperse aerosol particles in the size range between 1 micron and 3 microns was measured in patients with obstructive lung disease and in normal people using equal breathing conditions for both groups. It turns out that for breathing conditions at rest, deposition for patients is higher, especially in the case of 1 micron particle: A second breathing pattern similar to forced exercise, but including a breath holding interval of 6 s after inhalation, is applied to throw some light on the effect of time-dependent deposition mechanisms. The results show less differences between both groups, indicating that enhanced gravitational deposition during respiratory pauses compensates for differences in lung morphometry.

Aerosols↗

PubMed1996

Thirty month variability of aerosol pulse dispersion and conventional lung function parameters in healthy middle aged smokers and nonsmokers.

Chronic cigarette consumption is a generally accepted reason for the development of chronic obstructive pulmonary disease (COPD). COPD correlates to histomorphological parameters of lung structure as well as pulmonary function tests (PFT). COPD related changes affect PFT determined by conventional methods (bodyplethysmography, spirometry) as well as parameters of convective gas mixing. This study evaluates the diagnostic potential of a non-invasive aerosol method for the discrimination between healthy smokers and nonsmokers in comparison to conventional PFT. The aerosol method is based on the inhalation of small aerosol pulses suspended in particle free air and determines their changes during the breathing maneuver. Changes of aerosol pulse parameters (APP) are used to describe the convective component of gas mixing during ventilation. PFT and APP were determined in 40 healthy subjects (nonsmoker: 51.1 +/- 1.5 years; smoker: 49.6 +/- 1.5 years, 39.1 +/- 2.2 pack years) before and after a time interval of 30 months. Conventional PFT in smokers and nonsmokers showed no relevant differences between the values at the beginning and the end of the observation period. Thirty months later, at the end of the observation interval, a very similar behavior of the APP was obtained, which strongly confirmed the prior observed differences between smokers and nonsmokers. The data suggest that cigarette smoke-induced variations of lung function are also detectable in clinically asymptomatic smokers. Even in cases of normal PFT, most APP are able to discriminate between healthy smokers and nonsmokers. Since PFT showed only minor differences between both groups, it is indicated that APP are superior to PFT in the detection of early disturbances of lung ventilation in healthy smokers. Mean values of PFT and APP in smokers and nonsmokers showed a high reproducibility of the data obtained at the beginning of the study as well as at the end of the observation period. The data of our study further confirm that parameters of pulmonary gas exchange and gas mixing are affected by cigarette smoke at an earlier time than parameters of breathing mechanics.

Aerosols↗

PubMed1996

Low-density lipoprotein susceptibility to in vitro oxidation in healthy smokers and nonsmokers.

We analyzed the susceptibility of low-density lipoproteins (LDL) to oxidation in 17 healthy smokers (43.3 +/- 16.8 pack-years) and 19 healthy nonsmokers, matched for age (smokers: 52 +/- 7 years; nonsmokers: 53 +/- 7 years), gender, and relative body mass. Cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, and apolipoprotein (apo) B were not different between smokers and nonsmokers; apo A-I was slightly lower in smokers (one-tailed P = 0.066). To study whether LDL from smokers were prone to in vitro oxidation than LDL from nonsmokers, we measured the time kinetics of diene formation and the production of malondialdehyde during oxidation of LDL in vitro. In smokers and nonsmokers, respectively, the mean (+/-SD) lag times (tinh) of diene formation were 111 +/- 26 and 100 +/- 27 min, the peak rates of diene formation (Vmax) were 5.99 +/- 2.34 and 6.34 +/- 2.30 mmol x min-1 x g-1, and the amounts of dienes produced during the propagation phase (dmax) were 250 +/- 264 and 248 +/- 56 mmol x g-1. Neither the malondialdehyde content of LDL (measured as thiobarbituric acid-reactive substances) before oxidation nor the amount of malondialdehyde generated during oxidation (smokers: 57.0 +/- 14.2 micromol x g-1; nonsmokers: 63.2 +/- 15.2 micromol x g-1 indicated any statistically significant effect of smoking. When nonsmokers and smokers were considered together, the amount of malondialdehyde generated during oxidation correlated with age (nonparametric rs = 0.405), body mass index (r2 = 0.573), and concentrations of apo B (rs = 0.480), cholesterol (rs = 0.448), triglycerides (rs = 0.436), and LDL cholesterol (rs = 0.398). Our data show that smoking is not associated with increased oxidizability of LDL in healthy men and women at ages 42-63 years.

Adult↗

PubMed1995

[Cyfra 21-1--a new tumor marker of the cytokeratin series in differential diagnosis of lung diseases].

BACKGROUND: Cyfra 21-1 is a novel marker for non small cell lung cancer. Up to now only few data about the value of Cyfra 21-1 in the diagnosis of malignant and non-malignant pulmonary diseases are available. Further the effect of long-time cigarette consumption on serum concentrations of Cyfra 21-1 has not been described. Aim of this study therefore was the determination of Cyfra 21-1 in different malignant and non-malignant pulmonary diseases and in healthy smokers and nonsmokers. PATIENTS: Sera of healthy individuals (control group, n = 121; 63 smokers and 58 nonsmokers), patients with chronic bronchitis (n = 50), lung fibrosis (n = 38), exogen allergic alveolitis (n = 32), lung tuberculosis (n = 45), sarcoidosis (n = 30), small cell lung cancer (n = 60), squamous cell carcinoma (n = 53), non-small cell carcinoma (n = 29) and adenocarcinoma (n = 52) were analyzed. RESULTS: Within the control group no significant differences of the Cyfra 21-1 serum concentration were observed between smokers and nonsmokers. Serum concentrations of Cyfra 21-1 were similar in the control group, patients with non-malignant pulmonary diseases and patients with small cell lung cancer whereas serum concentrations were significantly increased in patients with non-small cell lung cancer, adenocarcinoma and squamous cell carcinoma. CONCLUSIONS: The data confirm the high sensitivity and specific of Cyfra 21-1 for the differential diagnosis between malignant and non-malignant pulmonary diseases as well as small cell and non-small cell lung cancer.

Adolescent↗