Michael Rolf Müller

Simvastatin Reduces Expression of Cytokines Interleukin-6, Interleukin-8, and Monocyte Chemoattractant Protein-1 in Circulating Monocytes From Hypercholesterolemic Patients

Objective—A number of studies have shown that statins decrease morbidity and mortality in patients with cardiovascular diseases. The anti-inflammatory effects of statins have recently been implicated in the clinical benefit that can be obtained in the treatment of atherosclerosis. Little is known about the mechanisms by which statins counteract inflammation. Methods and Results—In this study, we asked whether simvastatin can influence in vitro and in vivo production of the proinflammatory cytokines interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1. A total of 107 hypercholesterolemic patients were treated with simvastatin. As measured by ELISA, serum levels of cytokines significantly decreased after 6 weeks of treatment (P <0.05). Furthermore, simvastatin decreased the expression of IL-6, IL-8, and monocyte chemoattractant protein-1 mRNA in peripheral blood mononuclear cells. Similar results were obtained in vitro by using cultured human umbilical vein endothelial cells and peripheral blood mononuclear cells from healthy normolipemic donors. Exposure to simvastatin, atorvastatin, or cerivastatin caused downregulation of the expression of cytokine mRNA in a time- and dose-dependent manner. Furthermore, all statins tested were able to reduce the concentrations of cytokines in cellular and extracellular fractions of human umbilical vein endothelial cells (P <0.05). Conclusions—Our data show that simvastatin is anti-inflammatory through the downregulation of cytokines in the endothelium and leukocytes. These effects may explain some of the clinical benefits of these drugs in the treatment of atherosclerosis.

Long-Term Results After Repeated Surgical Removal of Pulmonary Metastases

BACKGROUND Although surgical resection is accepted widely as first-line therapy for pulmonary metastases, few data exist on the surgical treatment of recurrent pulmonary metastatic disease. In a retrospective study, we analyzed patients who were operated on repeatedly for recurrent metastatic disease of the lung with curative intent over a 20-year period. METHODS From 1973 to 1993, 396 metastasectomies were performed in 330 patients. The study population included patients with any histologic tumor type who had undergone at least two (range, 2 to 4) complete surgical procedures because of recurrent metastatic disease. Surgical and functional resectability of the recurrent lung metastases and control of the primary lesion served as objective criteria for reoperation. A subgroup of 35 patients that included patients with histologic findings such as epithelial cancer and osteosarcoma then was analyzed retrospectively to calculate prognosis and define selection criteria for repeated pulmonary metastasectomy. RESULTS The 5- and 10-year survival rates after the first metastasectomy were 48% and 28%, respectively. The overall median survival was 60 months. A mean disease-free interval (calculated for all intervals, with a minimum of two) of greater than 1 year was significantly associated with a survival advantage beyond the last operation. Univariate analysis failed to show size, number, increase or decrease in number or size, or distribution of metastases as factors related significantly to survival. CONCLUSIONS Although patients with different histologic tumor types were included, the study population appeared to be homogeneous in terms of survival benefit and prognostic factors, and it probably represented the selection of biologically favorable tumors in which histology, size, number, and laterality are of minor importance. We conclude that patients who are persistently free of disease at the primary location but who have recurrent, resectable metastatic disease of the lung are likely to benefit from operation a second, third, or even fourth time.

Specific Activation of Human Mast Cells by the Ligand for c-Kit: Comparison between Lung, Uterus and Heart Mast Cells

Recent data suggest that stem cell factor (SCF or c-kit ligand, KL) is a major regulator of human mast cells (MCs). In the present study, MCs derived from the lung (n = 8), uterus (n = 14) and heart (n = 4) were analyzed for expression of c-kit receptor and for responses to recombinant SCF. MCs of all organs tested were recognized by mAbs to c-kit (YB5.B8, SR-1) as assessed by combined toluidine blue/immunofluorescence staining. Activation by rhSCF (10 ng/ml, 60 min) resulted in histamine release from lung MCs (SCF 12.8 +/- 2.7% histamine release; control 2.8 +/- 0.8%, p < 0.01), uterus MCs (SCF 16.8 +/- 5.8%; control 5.2 +/- 2.5%, p < 0.01) and heart MCs (SCF 18.4 +/- 2.6%; control 1.7 +/- 0.23%, p < 0.01). Short-term pre-incubation with rhSCF (15 min) did not result in histamine secretion (p > 0.05), but in an increase (lung 2.4 +/- 1.0 fold; uterus 2.1 +/- 1.1 fold, and heart 2.0 +/- 0.4 fold) of alpha IgE-induced mediator release (p < 0.05). The effects of SCF were dose-dependent (maximum responses at 10-100 ng/ml) and dependent on extracellular calcium. A monoclonal antibody to SCF was found to inhibit the effects of SCF on MCs. Furthermore, MCs could be desensitized specifically by pre-incubation of MCs with rhSCF in Ca-free medium. Together, these data suggest that SCF triggers mediator secretion from MCs in various organs via binding to the c-kit receptor.

Influence of hematocrit and platelet count on impedance and reactivity of whole blood for electrical aggregometry

Previous studies have shown that differing qualities of blood specimen seem to influence whole blood electrical aggregometry (WBEA), making it difficult to standardize the method. The aim of this study was to investigate the impact of hematocrit (HCT) and platelet count (PLC) on in vitro platelet aggregation in citrated whole blood (CWB) in order to compensate for their possible effects on impedance aggregometry. Red blood cells and blood platelets were isolated from fresh citrated whole blood taken from 15 healthy donors (mean age = 26 years) and recombined to 20 physiologically relevant combinations of hematocrit and platelet count (HCT: 20-50, PLC: 100-500). Platelet aggregability was measured using WBEA with three different triggers. A special-purpose software package was used in this study, ensuring proper calibration, acquisition, and evaluation of analogue to digital converted data, allowing the calculation of a set of characteristic parameters of each impedance curve. Most of the linear regressions showed that all parameters significantly depend on HCT and PLC. Furthermore, we found interactions of both variables, making it impossible to focus on the effects of one of the investigated variables only. The outcome of this study is a set of dependences, allowing the calculation of regressions for in vitro aggregation in whole blood, enabling a comparison of blood of any quality with each other, regardless of the variables HCT and PLC. Together with the previously defined dependence of sample age on WBEA data, this step should help to make this technique a more reliable and practicable clinical tool, making it suitable for daily routine investigations.

Minimization of hemolysis in centrifugal blood pumps: influence of different geometries.

Centrifugal blood pumps are of substantial importance for intraoperative extracorporeal circulation and for temporary cardiac assist. Their development and improvement raises many specific questions, especially on mechanical blood properties, flow distribution, and the resulting biocompatibility. In this comprehensive study the influence of various pump geometries on blood trauma was investigated. For this purpose analytical calculations, hydrodynamic performance, numerical simulation, in vitro hemolysis tests and in vivo experiments were used. The gap between rotor and housing was found to be crucial showing a distinct minimum of hemolysis at a gap of 1.5 mm (in vitro increase of plasma free hemoglobin per 100 ml plasma an hour: ΔfHb/hour = 2.4±0.83 mg%/h at 1.5 mm versus 12 ± 2.2 mg%/h at 2.5 mm; p < 0.05). Housing diameter and shape of the vanes were of less importance for blood traumatization (d = 60 mm: ΔfHb/hour = 6.36 ± 1.8 mg%/h; d = 70 mm: fHb = 7.1 ± 1.9 mg%/h; straight radial vanes: 5.2 ± 1.8 mg%/h; straight inclined vanes: 6.8 ± 1.2 mg%/h; flexed vanes: 6.1 ± 2.0 mg%/h). Three animal experiments confirmed the optimization of geometry, with a mean fHb of 2.5 to 3.2 mg% in steady state. Hydrodynamic efficiency revealed to be a necessary, but not a sufficient and sensitive criterion for hemolysis minimization (e.g. changes of η < 10% for changes of fHb > 500%). Numerical simulation gives an improved insight in flow distribution, but can not yet be applied for quantification of blood trauma. The study supports theories on mechanical hemolysis predicting a hemolysis at shear levels of less than 500N/m2 depending on exposure time. With the methods used it was possible to develop a pump with very low hemolysis potential. For further reduction of blood trauma and correlated thrombus formation basic studies on cell damage in recirculating blood and also advanced flow studies in rotary pumps would be desirable.

Effects of cyclosporin A and FK-506 on stem cell factor–induced histamine secretion and growth of human mast cells ☆ ☆☆ ★ ★★

Stem cell factor (SCF) is a key regulator of human mast cells (MCs) and a potential mediator of allergy. In this study the effects of cyclosporin A (CSA) and FK-506, two potent immunosuppressive drugs, on SCF-dependent histamine release and growth of human MCs were analyzed. Preincubation of tissue MCs with CSA (3 micrograms/ml) resulted in inhibition of histamine release provoked by either recombinant human (rh) SCF (70.3% +/- 20.6% inhibition, p < 0.001) or anti-IgE (76.7% +/- 21.9%, p < 0.001) or by rhSCF+ anti-IgE (77.4% +/- 13.9%, p < 0.001). Almost the same inhibition was produced by FK-506 (rhSCF: 82.0% +/- 18.9% inhibition, p < 0.001; anti-IgE: 71.5% +/- 16.7%, p < 0.001; rhSCF+ anti-IgE: 70.0% +/- 7.3%, p < 0.001). The effects of CSA and FK-506 on SCF-dependent release of histamine were dose-dependent (IC50: CSA, 1 to 10 ng/ml; FK-506, 0.3 to 3 ng/ml). IC50 values about three to 10 times higher were found for MCs preincubated with rhSCF before anti-IgE activation, compared with anti-IgE or SCF alone. SCF-dependent differentiation of human MCs was analyzed in a long-term suspension culture system (n = 6). Unexpectedly, CSA and FK-506 were unable to suppress, but even enhanced SCF-dependent growth of MCs and formation of MC tryptase in long-term culture. Together, CSA and FK-506 inhibit SCF-dependent release of histamine from human MCs and even augment SCF-dependent growth of human MCs in long-term culture.

Differential response of human basophils and mast cells to recombinant chemokines

Chemokines are proinflammatory peptides regulating the functions of various hematopoietic cells. We have analyzed the effects of seven recombinant human (rh) chemokines (MCAF, RANTES, MIP-1α, MIP-1β, IL-8, GRO, and IP-10) on the growth and function of human basophils and mast cells. We found that MCAF, but not RANTES, MlP-la, MIP-1β, IL-8, GRO, or IP-10, causes direct and dose-dependent histamine release from basophils (MCAF, 5 μg/ml: 26.9 ± 3.4%; other chemokines: < 5% of total histamine). An increased (2.1 to 3.5-fold) response to MCAF was obtained when basophils were preincubated with rh interleukin-3 (100 units/ml). Moreover, IL-3-primed basophils became responsive to physiologic concentrations (< 1 μg/ml) of MCAF, IL-8, and RANTES. None of the chemokines tested was able to induce histamine secretion in mast cells obtained from lung (n=2), skin (n=1), uterus (n=3), or tonsils (n=3), even when cells had been preincubated with the mast cell agonist SCF. The chemokines also failed to modulate the expression of activation antigens (CD11b/C3biR, CD25/IL-2Rβ, CD63, IL-3Rα, CD117/c-kit) on the mast cell line HMC-1 or the basophil cell line KU-812 and were unable to induce differentiation of basophils or mast cells in culture. Together, our results show that basophils respond to rhIL-8, rhMCAF, and rhRANTES and that, unlike human basophils, human mast cells are unresponsive to recombinant chemokines.

Endoscopic One-Way Valve Implantation in Patients With Prolonged Air Leak and the Use of Digital Air Leak Monitoring

BACKGROUND Prolonged alveolar-pleural air leaks are associated with increased morbidity and mortality. Endoscopic valve therapy has been recently introduced as a potential less invasive treatment option. We aimed at quantifying the effects of valve therapy on air leak flow and clinical outcomes in patients with prolonged air leaks. METHODS We report on a series of 16 patients with high comorbidity and evidence of continuous air leak flow in whom chest tubes remained in place for at least 7 days. After identification of the source of the air leak by use of the balloon occlusion technique, endobronchial one-way valves were implanted. Digital chest tube monitoring was used to assess air leak flow before, during, and after valve implantation until chest tube removal. RESULTS The source of the air leak was endoscopically identified in 13 patients (81%). After valve implantation, air leak flow decreased significantly from 871±551 mL/min to 61±72 mL/min immediately after the intervention (p<0.001). The mean duration of chest tube drainage was 18±8 days before and 9±6 days after the intervention (p<0.01). Ten patients were considered responders, and 3 patients were nonresponders. Responders demonstrated consistent air leak flow levels below 100 mL/min until chest tube removal. Long-term follow-up was available for 9 patients. No adverse events related to the valve implants were reported at follow-up. Seven patients underwent valve removal without any further complications. CONCLUSIONS Endoscopic implantation of one-way valves leads to a significant reduction in air leakage flow and may thus be a valuable treatment option in patients with prolonged air leakage.

Autoantibody Reactivity in a Case of Schnitzler’s Syndrome: Evidence for a Th1-Like Response and Detection of IgG2 Anti-FcεRIα Antibodies

Schnitzler’s syndrome is a rare disease characterized by chronic urticaria, monoclonal IgM, and clinical and laboratory signs of inflammation. In a subset of patients, the urticarial lesions cause pruritus. However, the pathophysiology of the disease and the biochemical basis of urticaria are not known. We describe a female patient with Schnitzler’s syndrome suffering from chronic urticaria associated with pruritus. The patient’s serum was found to contain IgG antibodies recognizing cellular components of the microvasculature. In particular, IgG3 antibodies directed against proteins (14–100 kD) expressed in cultured dermal microvascular endothelial cells and mast cells, were found by immunoblotting. Moreover, IgG2 antibodies specific for the α-chain of the FcεRI were detectable. However, the autoantibodies did not mediate histamine release in mast cells or basophils. In patients with IgM paraproteinemia who did not have Schnitzler`s syndrome, antibodies against endothelial/mast cells or FcεRI were not detectable. In summary, we describe subclass-specific IgG reactivity against microvascular endothelial cells and mast cells indicating Th1 autoimmunity in a patient with Schnitzler’s syndrome. Whether such autoantibodies are recurrently produced in patients with Schnitzler’s syndrome and play a role in the pathophysiology of the disease remains to be determined.

Signifikante Verlängerung des Überlebens durch komplette Resektion isolierter Lungenmetastasen nach Mammacarcinom

Summary. At least 25 % of breast cancer patients develop distant metastases. In spite of increasingly sophisticated palliative therapies, the survival time of patients with metastasis did not appear to be significantly prolonged during the last 25 years (19–32 months following diagnosis) and 95 % of them die from metastatic disease. Therefore, it seems appropriate that the therapeutic risk/benefit ratio and impact on quality of life should be reassessed when asymptomatic patients are treated. Surgical treatment and pulmonary resection for metastatic disease has been proven a valuable therapeutic concept for a variety of malignancies. Three epidemiologically comparable collectives out of a total of 125 patients from our clinic were treated for isolated pulmonary metastasis following breast cancer (observation period: 1977–1997). Complete data sets could be established for 96 patients and were retrospectively analyzed following stratification into three groups according to their surgical therapy. Twenty-eight patients underwent complete resection (K), 34 had incomplete resections (I) and 34 had no surgical intervention for lung metastases (N). Comparison of the three therapy arms concerning stage, histology and receptor levels of the primary tumor, number of metastases, and the disease-free interval yielded no significant differences between groups K, I and N. Patients after complete resection of isolated lung metastases (group K) had a mean survival of 79 months (5-year survival 80 %, 10-year survival 60 %). This was significantly better than groups I and N (P < 0.00002). The mean survival of groups I and N was not significantly different (15.5 and 9 months respectively). The disease-free interval after operation of the primary tumor had no impact on the survival of group K, but showed a high correlation with the survival of group N (R2 = 0.81). Complete resection of isolated pulmonary metastases from carcinoma of the breast results in marked prolongation of survival with a low morbidity rate. Hence, routine chest X-ray should be considered an indispensable part of the oncological aftercare in breast cancer patients.Zusammenfassung. Zumindest ein Viertel aller Patienten mit Mammacarcinom kommen in ein metastasierendes Stadium. Ungeachtet der laufenden Adaptierung palliativer Therapiemodalitäten blieb das mittlere Überleben in diesem Stadium innerhalb von 25 Jahren unverändert (19–32 Monate nach Diagnose), und 95 % dieser Patientinnen starben an der Generalisierung des Malignoms. Das erste Therapieziel muß deshalb Schaffung und Erhaltung von Lebensqualität sein. Daneben hat sich die chirurgische Entfernung isolierter Lungenmetastasen nach anderen Malignomen als therapeutisches Konzept durchgesetzt. Berichtet wird von 3 epidemiologisch vergleichbaren Kollektiven aus insgesamt 125 Patientinnen unserer Abteilung mit isolierten Lungenmetastasen nach Mammacarcinom (Beobachtungszeitraum 1977–1997). Von 96 Patientinnen waren komplette Datensätze erhebbar, sodaß sie retrospektiv entsprechend der chirurgischen Therapie in 3 Gruppen stratifiziert werden konnten. 28 Patientinnen wurden komplett (K), 34 inkomplett (I) und 34 nicht (N) reseziert. Der Vergleich der 3 Therapiegruppen N, K und I untereinander hinsichtlich Tumorstadium, Histologie und Receptorstatus des Primärtumors, Anzahl der Metastasen und des tumorfreien Intervalls ergab keine statistisch signifikanten Unterschiede. Das mittlere Überleben der Gruppe K war mit 79 Monaten nach Resektion der Lungenmetastasen (5-Jahres-Überleben 80 %, 10-Jahres-Überleben 60 %) signifikant besser im Vergleich zu den Gruppen I und N (p <0,00002). Das mittlere Überleben der Gruppen I und N war mit 15,5 und respektive 9 Monaten nicht signifikant unterschiedlich. Das tumorfreie Intervall nach Operation des Primärtumors hatte auf die Prognose der Gruppe K keinen Einfluß, korrelierte aber mit dem Überleben in Gruppe N (R2 = 0,81). Die komplette Resektion isolierter Lungenmetastasen nach Mammacarcinom führt zu einer ausgeprägten Lebensverlängerung bei geringer Morbidität. Das Thoraxröntgen stellt daher einen unverzichtbaren Bestandteil des onkologischen Nachsorgeprogramms nach Mammacarcinom dar.