[Diagnostic yield and safety of bronchoscopic cryotechnique in routine diagnostics for suspected lung cancer]. / Diagnostischer Wert und Sicherheit der bronchoskopischen Kryotechnik im Routineeinsatz bei Verdacht auf Lungenkarzinom.

BACKGROUND: Cryoprobes with flexible catheters are an additional important tool for endobronchial interventional therapy and histologic diagnosis. Different studies compared the diagnostic effectiveness and complications to the forceps as a standard. However, routine endoscopic procedures require a combined use of different methods in order to achieve the highest diagnostic yield. We investigated the impact of cryotechnique in comparison with combined diagnostic tools during routine diagnostics of malignant tumors. PATIENTS AND METHODS: A consecutive series of patients undergoing routine diagnostic for lung cancer was included over a 30 months period (n = 469). The use of the cryotechnique, the complication rates and diagnostic value were prospectively documented. Cryotechnique was used on top of conventional technologies. RESULTS: A histologic proof of tumor by cryotechnique in centrally located tumors was delivered more frequently compared to forceps biopsies alone (81.4 versus 59.9% and 66.2 versus 37.7% in peripheral lesions). However, when the other non-cryotechniques were taken into account, the value was reduced in central probes (7.4%; p = 0.02), but remained high for peripheral findings (19.3%; p < 0.002). The frequency of complications seemed unchanged, however severe bleeding occurred. CONCLUSION: The cryotechnique bears high diagnostic potential beside its therapeutic value, also in routine investigations. The changed complication profile of this technology needs to be addressed in the informed consent and secured airway management may be helpful.

[Frequency of thromboembolic complications in patients with lung cancer]. / Häufigkeit thromboembolischer Komplikationen bei Patienten mit Lungenkarzinom.

BACKGROUND: Clinicians are frequently confronted by thromboembolic events in patients with lung cancer, yet few data are available about their incidence. In order to obtain data on the frequency of thromboembolic events in the venous and arterial systems, all patients with lung cancer diagnosed in our hospital were retrospectively evaluated with regard to such an event. PATIENTS/METHODS: All patients with a primary diagnosis of lung cancer between January 2008 and December 2010 were prospectively recorded within our tumour registry and retrospectively evaluated with regard to tumour stage, histology and platinum-based chemotherapy. Thromboembolic complications of the arterial and the venous system were included (pulmonary embolism, deep venous thrombosis, myocardial infarction, mesenterial ischaemia, acute limb ischaemia, ischaemia of the renal artery and ischaemic stroke). RESULTS: Within those 36 months 1940 patients (1209 men, 731 women) were diagnosed with lung cancer. SCLC and NSCLC in 156 (8 %) and 1784 cases (92 %), respectively. Thromboembolic events were documented in 190/1940 (9.8 %) cases, venous thromboembolic complications in 148/190 patients (78 %), arterial thromboembolic complications in 51/190 patients (27 %). We documented 82/148 (55 %) deep venous thrombosis, 98/148 (66 %) pulmonary embolisms and arterial thromboembolic events: ischaemic stroke 23/51 (45 %), coronary arteries 14/51 (28 %), peripheral arteries 12/51 (24 %), mesenterial arteries 4/51 (7.8 %), extracranial cerebral arteries 3/51 (5.9 %). CONCLUSIONS: Thromboembolic complications are a common event in patients with lung cancer. Thus, the benefit of primary prevention anticoagulation in lung cancer patients should be prospectively evaluated.

[Diagnosis and therapy of COPD exacerbation]. / Diagnose und Therapie der COPD-Exazerbation.

The acute exacerbation of COPD (AECOPD) is a life-threatening clinical situation. This review summarizes the definition of AECOPD, the severity assessment, typical clinical signs and symptoms, and refers to clinical pitfalls of diagnosis and therapy. Important aspects of clinical history and physical examination in severe exacerbations are reported. The necessary accompanying examinations like chest X-ray, blood gas analysis, ECG and echocardiography and their differential diagnosis as well as therapeutic significance are described. The most important lab examinations are summarized and controversial parameters, e.g., procalcitonin, are commented upon. The differentiated need for a microbiological sputum screening is emphasized. The authors place special weight on the essential components of the therapeutic management of severe AECOPD. Practical aspects of uncontrolled oxygen therapy, drug selection, and application form of inhalative acute therapy, dose, and duration of glucocorticoids, the indication for antibiotics, mechanical ventilation, and also opiates are summarized.

[Rational tumour documentation and quality assurance to improve the standard of medical care for lung cancer patients]. / Rationale Tumordokumentation und Qualitätssicherung zur Verbesserung der Versorgungsqualität für Lungenkrebspatienten.

The data on the quality of care of patients with lung cancer in Germany are insufficient. Although the National Lung Cancer Guideline from 2010 provides a good scientific basis for the management of the frequently complex pathways, no evidence exists showing how the relevant guideline recommendations are implemented nationwide or which treatment options generally are chosen in a tumour entity with one of the poorest prognoses. As part of the National Cancer Plan 2008, specific targets have been formulated for the systematic improvement of cancer care in Germany. As a main goal, the national re-organisation and harmonisation of tumor documentation and quality assurance are required for a sustainable improvement in the quality of care. This review article first describes the relevant terms and then examines how the specific targets of the National Cancer Plan have been implemented so far with regard to lung cancer care.

[Lung cancer in Germany - the current state of management]. / Lungenkrebs in Deutschland - zur Versorgungslage der Nation.

BACKGROUND: The care of lung cancer patients in Germany has not been systematically evaluated yet. The aim of this article is to give an overview on the current state of lung cancer care on the basis of existing data. METHODS: In April and May 2010, a literature search was performed in order to collect relevant information concerning epidemiology as well as diagnostic, therapeutic (systemic therapy, radiotherapy, surgery, palliative therapy), and interdisciplinary structures in lung cancer treatment. RESULTS: The published database on lung cancer care in Germany is overall deficient. Treatment of lung cancer patients is mainly located in hospitals, particularly in chest clinics or specialised departments. The access of hospitals for an outpatient treatment as provided per § 116 b SGB V has not yet been realised in all German states. CONCLUSIONS: A systematic and prospective evaluation of lung cancer care is necessary in order to better allocate resources in the future.

Flt3 mutations from patients with acute myeloid leukemia induce transformation of 32D cells mediated by the Ras and STAT5 pathways.

Somatic mutations of the receptor tyrosine kinase Flt3 consisting of internal tandem duplications (ITD) occur in 20% of patients with acute myeloid leukemia. They are associated with a poor prognosis of the disease. In this study, we characterized the oncogenic potential and signaling properties of Flt3 mutations. We constructed chimeric molecules that consisted of the murine Flt3 backbone and a 510-base pair human Flt3 fragment, which contained either 4 different ITD mutants or the wild-type coding sequence. Flt3 isoforms containing ITD mutations (Flt3-ITD) induced factor-independent growth and resistance to radiation-induced apoptosis in 32D cells. Cells containing Flt3-ITD, but not those containing wild-type Flt3 (Flt3-WT), formed colonies in methylcellulose. Injection of 32D/Flt3-ITD induced rapid development of a leukemia-type disease in syngeneic mice. Flt3-ITD mutations exhibited constitutive autophosphorylation of the immature form of the Flt3 receptor. Analysis of the involved signal transduction pathways revealed that Flt3-ITD only slightly activated the MAP kinases Erk1 and 2 and the protein kinase B (Akt) in the absence of ligand and retained ligand-induced activation of these enzymes. However, Flt3-ITD led to strong factor-independent activation of STAT5. The relative importance of the STAT5 and Ras pathways for ITD-induced colony formation was assessed by transfection of dominant negative (dn) forms of these proteins: transfection of dnSTAT5 inhibited colony formation by 50%. Despite its weak constitutive activation by Flt3-ITD, dnRas also strongly inhibited Flt3-ITD-mediated colony formation. Taken together, Flt3-ITD mutations induce factor-independent growth and leukemogenesis of 32D cells that are mediated by the Ras and STAT5 pathways. (Blood. 2000;96:3907-3914)

Transforming growth factor beta1 is a target for the von Hippel-Lindau tumor suppressor and a critical growth factor for clear cell renal carcinoma.

The von Hippel-Lindau (VHL) tumor suppressor gene is mutated in patients with VHL disease and in the majority of patients with sporadic clear cell renal carcinoma (RCC). Overexpression of transforming growth factor (TGF) beta1 has been observed in patients with several cancers, including RCCs, with serum and urine levels correlating inversely with prognosis. We have demonstrated that the VHL tumor suppressor gene product represses TGF-beta1 mRNA and protein levels (approximately 3-4-fold) in 786-O RCC cells by decreasing the TGF-beta1 mRNA half-life. Exogenously added TGF-beta1 did not suppress the growth of 786-O cells in vitro, nor did the addition of neutralizing antibody (Ab) against TGF-beta have any effect. Indeed, 786-O cells were found to express no TGF-beta type II receptor protein, thus allowing them to escape from the negative growth control of TGF-beta1. In contrast to the in vitro data, neutralizing Ab to TGF-beta inhibited tumorigenesis and, in some cases, regressed established 786-O tumors in athymic mice. Immunohistochemistry for von Willebrand's factor revealed a 3-4-fold lower tumor microvessel count in the mice treated with TGF-beta Ab compared to controls, suggesting that the Ab was inhibiting angiogenesis. Our findings indicate that TGF-beta1 is a novel target for the VHL tumor suppressor and that antagonizing its paracrine action may provide novel avenues for treatment of RCCs as well as other tumors that secrete TGF-beta1.

Modulation of renal tubular cell function by RGS3.

The recently discovered family of regulators of G protein signaling (RGS) accelerates the intrinsic GTPase activity of certain Galpha subunits, thereby terminating G protein signaling. Particularly high mRNA levels of one family member, RGS3, are found in the adult kidney. To establish the temporal and spatial renal expression pattern of RGS3, a polyclonal antiserum was raised against the COOH terminus of RGS3. Staining of mouse renal tissue at different gestational stages revealed high levels of RGS3 within the developing and mature tubular epithelial cells. We tested whether RGS3 can modulate tubular migration, an important aspect of tubular development, in response to G protein-mediated signaling. Several mouse intermedullary collecting duct (mIMCD-3) cell lines were generated that expressed RGS3 under the control of an inducible promoter. Lysophosphatidic acid (LPA) is a potent chemoattractant that mediates its effects through heterotrimeric G proteins. We found that induction of RGS3 significantly reduced LPA-mediated cell migration in RGS3-expressing mIMCD-3 clones, whereas chemotaxis induced by hepatocyte growth factor remained unaffected by RGS3. Our findings suggest that RGS3 modulates tubular functions during renal development and in the adult kidney.

The polycystic kidney disease 1 gene product modulates Wnt signaling.

Two distinct signaling pathways, involving Wnt signaling and polycystin, have been found to be critical for normal kidney development. Renal tubulogenesis requires the presence of certain Wnt proteins, whereas mutations in polycystin impede the terminal differentiation of renal tubular epithelial cells, causing the development of large cystic kidneys that characterize autosomal dominant polycystic kidney disease. Polycystin is an integral membrane protein, consisting of several extracellular motifs indicative of cell-cell and cell-matrix interactions, coupled through multiple transmembrane domains to a functionally active cytoplasmic domain. We report here that expression of the C-terminal cytoplasmic domain of polycystin stabilizes soluble endogenous beta-catenin and stimulates TCF-dependent gene transcription in human embryonic kidney cells. Microinjection of the polycystin C-terminal cytoplasmic domain induces dorsalization in zebrafish. Our findings suggest that polycystin has the capacity to modulate Wnt signaling during renal development.

Wnt signaling and transcriptional control of Siamois in Xenopus embryos.

The Wnt-inducible homeobox gene Siamois is expressed in Xenopus embryos before gastrulation and is necessary for formation of the Spemann organizer. Here we show that 5'-flanking sequences of the Siamois coding region can specifically activate a heterologous reporter gene in dorsovegetal cells, thus mimicking Siamois's endogenous expression. A 245-bp DNA fragment is sufficient for activation by both Wnts and endogenous inducers. A dominant negative form of Xenopus T cell-specific factor 3 (XTCF-3) inhibited promoter activity, indicating that T cell-specific factor (TCF)/lymphocyte enhancer binding factor 1 (LEF-1) signaling is necessary for regulation of Siamois. Mutagenesis of two individual TCF sites in the -245 promoter revealed that the proximal, but not distal, site is necessary for dorsovegetal activation. These observations suggest that Siamois is directly regulated by TCFs during dorsoventral axis determination. Further deletion analysis identified a positive regulatory region that is required for dorsal activation, but not for Wnt inducibility, of the promoter. We also present evidence for autoregulation of Siamois transcription. Furthermore, the Siamois promoter was activated by Wnt signaling in 293T tissue culture cells, demonstrating that regulation of the promoter is functionally conserved.

The polycystic kidney disease 1 gene product mediates protein kinase C alpha-dependent and c-Jun N-terminal kinase-dependent activation of the transcription factor AP-1.

Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disorder that accounts for 8-10% of end stage renal disease. PKD1, one of two recently isolated ADPKD gene products, has been implicated in cell-cell and cell-matrix interactions. However, the signaling pathway of PKD1 remains undefined. We found that the C-terminal 226 amino acids of PKD1 transactivate an AP-1 promoter construct in human embryonic kidney cells (293T). PKD1-induced transcription is specific for AP-1; promoter constructs containing cAMP response element-binding protein, c-Fos, c-Myc, or NFkappaB-binding sites are unaffected by PKD1. In vitro kinase assays revealed that PKD1 triggers the activation of c-Jun N-terminal kinase (JNK), but not of mitogen-activated protein kinases p38 or p44. Dominant-negative Rac-1 and Cdc42 mutations abrogated PKD1-mediated JNK and AP-1 activation, suggesting a critical role for small GTP-binding proteins in PKD1-mediated signaling. Several protein kinase C (PKC) inhibitors decreased PKD1-mediated AP-1 activation. Conversely, expression of the C-terminal domain of PKD1 increased PKC activity in 293T cells. A dominant-negative PKC alpha, but not a dominant-negative PKC beta or delta, abrogated PKD1-mediated AP-1 activation. These findings indicate that small GTP-binding proteins and PKC alpha mediate PKD1-induced JNK/AP-1 activation, together comprising a signaling cascade that may regulate renal tubulogenesis.

2,5-Hexanedione is a potent gliatoxin in in-vitro cell cultures of the nervous system.

Of the metabolites of hexane, 2,5-hexanedione (2,5 HD) has the strongest neurotoxic effect. There is a wealth of experimental studies in animals showing an axonotoxic mechanism consisting of an accumulation of 10 nm neurofilaments. Only few studies deal with a possible action of 2,5-HD on Schwann cells, glia cells or both. Pure neurons, pure glia and mixed cultures prepared from dorsal root ganglia (DRG) of chick embryos were studied in this model. DRG were chosen because they constitute a linkage between the peripheral and central nervous system and provide the additional advantage of containing only few defined glial and neuronal cell types. Additionally, pure neuronal cultures of sympathetic ganglia and mixed cultures of spinal cord and brain were prepared. In cultures of the different parts of the nervous system investigated, we observed at a concentration of 0.25% 2,5-HD massive toxic alterations of glial cells, whereas neurons and neurites were virtually unaffected.

Specific neurotoxic effects of different organic solvents on dissociated cultures of the nervous system.

Pure neurons were prepared from dorsal root ganglia (DRG) of 8 day old chick embryos (E8). The substances tested in this model were pure n-hexane, 2.5-hexanedione (2.5 HD) and methyl-ethyl-ketone (MEK). Differentiated cultures were exposed to these neurotoxins after two days in culture and then examined over a period of up to one week. For all three substances a specific neurotoxic effect could be demonstrated: (i) n-Hexane mainly altered the neurites, leading to focal swellings and in a second step to degenerative changes in glial cells; (ii) 2.5 HD had a minor effect on neurons and proved to be mainly gliatoxic; (iii) MEK primarily affected the neurons by swelling and disintegration of the cell body.