Decreased microglial numbers in Vav1-Cre+:dicer knock-out mice suggest a second source of microglia beyond yolk sac macrophages.

Microglia represent the resident macrophages of the central nervous system (CNS). While it is clear that microglia recruitment is established by differentiation of primitive yolk sac (YS) macrophages and consecutive invasion of the brain, starting around E8 in rodents (Ginhoux et al., 2010), more recent studies suggest that a non-YS contribution to the microglia population should not entirely be dismissed (Swinnen et al., 2013; Xu et al., 2015). Therefore, we used Vav1-Cre+:dicer knock-out mice in order to study the effect of the post-YS hematopoiesis on the definitive microglial population in late prenatal (E16.5, E18.5) and early postnatal brains (P0, P1). Since Vav1 is thereby exclusively expressed in hematopoietic cells starting at E11, the depletion of the micro RNA processing enzyme dicer in Vav1-positive cells allows interfering with post-YS microglia recruitment. Using this approach, analysis of the number of Iba-1 positive microglia revealed a reduction of microglial numbers by 40% in knock-out mice at P1 compared to their individual control littermates. Noteworthy, immunolabeling for Ki-67 and active caspase 3 confirmed that the differences in the microglial numbers are not related to differential rates of proliferation or apoptosis. Therefore, our data demonstrates that interfering with the definitive hematopoiesis highly impacts on the microglial population, implicating an important role of post-YS hematopoiesis on microglial development and recruitment.

Genetic loss of Gas6 induces plaque stability in experimental atherosclerosis.

The growth arrest-specific gene 6 (Gas6) plays a role in pro-atherogenic processes such as endothelial and leukocyte activation, smooth muscle cell migration and thrombosis, but its role in atherosclerosis remains uninvestigated. Here, we report that Gas6 is expressed in all stages of human and mouse atherosclerosis, in plaque endothelial cells, smooth muscle cells and macrophages. Gas6 expression is most abundant in lesions containing high amounts of macrophages, ie thin fibrous cap atheroma and ruptured plaque. Genetic loss of Gas6 does not affect the number and size of initial and advanced plaques in ApoE(-/-) mice, but alters its plaque composition. Compared to Gas6(+/+): ApoE(-/-) mice, initial and advanced plaques of Gas6(-/-): ApoE(-/-) mice contained more smooth muscle cells and more collagen and developed smaller lipid cores, while the expression of TGFbeta was increased. In addition, fewer macrophages were found in advanced plaques of Gas6(-/-): ApoE(-/-) mice. Hence, loss of Gas6 promotes the formation of more stable atherosclerotic lesions by increasing plaque fibrosis and by attenuating plaque inflammation. These findings identify a role for Gas6 in plaque composition and stability.

Placental growth factor and its receptor, vascular endothelial growth factor receptor-1: novel targets for stimulation of ischemic tissue revascularization and inhibition of angiogenic and inflammatory disorders.

In contrast to VEGF and its receptor VEGFR-2, PlGF and its receptor VEGFR-1 have been largely neglected and therefore their potential for therapy has not been previously explored. In this review, we describe the molecular properties of PlGF and VEGFR-1 and how this translates into an important role for PlGF in the angiogenic switch in pathological angiogenesis, by interacting with VEGFR-1 and synergizing with VEGF. PlGF was effective in the growth of new and stable vessels in cardiac and limb ischemia, through its action on different cell types (i.e. endothelial, smooth muscle and inflammatory cells and their precursors) that play a cardinal role in blood vessel formation. Accordingly, blocking its receptor VEGFR-1 with monoclonal antibodies (anti-VEGFR-1 mAb), expressed on al these cell types, successfully attenuated blood vessel formation during cancer, ischemic retinopathy and rheumatoid arthritis. In addition, while blocking this receptor was effective in reducing inflammatory disorders like atherosclerosis and rheumatoid arthritis, blocking the anti-angiogenic receptor VEGFR-2 was without effect. This indicates that in the latter diseases the beneficial effects of anti-VEGFR1 mAb were mainly due to its effect on inflammatory cells. Importantly, VEGFR-1 was also present on hematopoietic stem/progenitor cells, the precursors of inflammatory cells. Thus, these preclinical studies show proof-of-principle that PlGF and VEGFR-1 are promising therapeutic targets to treat angiogenesis and inflammation related disorders. Clinical trials will reveal whether this is also true for patients.

External irradiation versus external irradiation plus endobronchial brachytherapy in inoperable non-small cell lung cancer: a prospective randomized study.

PURPOSE: No randomized studies are available on the additional value of endobronchial brachytherapy (EBB) to external irradiation (XRT) regarding palliation of respiratory symptoms (RS). A prospective randomized study was initiated to test the hypothesis that the addition of EBB to XRT provides higher levels of palliation of dyspnea and other RS and improvement of quality of life (QoL) in patients with non-small cell lung cancer (NSCLC) with endobronchial tumour. MATERIALS AND METHODS: Patients with previously untreated NSCLC, stages I-IIIb, WHO-performance status of 0-3 and with biopsy proven endobronchial tumour in the proximal airways were eligible. EBB consisted of two fractions of 7.5 Gy at 1 cm on day 1 and 8. XRT started at day 2. The XRT dose was 30 Gy (2 weeks) or 60 Gy (6 weeks). The EORTC QLQ-C30 and QLQ-LC13 were assessed before treatment and 2 weeks, 6 weeks, 3, 6 and 12 months after treatment. Re-expansion of collapsed lung was tested by the inspiratory vital capacity (IVC) and CT scan of the chest. RESULTS: Ninety-five patients were randomized between arm 1 (XRT alone) (n=48) or arm 2 (XRT+EBB) (n=47). The arms were well balanced regarding pre-treatment characteristics and QoL scores. The compliance for QoL-assessment was >90% at all times. No significant difference between the trial arms was observed with respect to response of dyspnea. However, a beneficial effect of EBB was noted concerning the mean scores of dyspnea over time (P=0.02), which lasted for 3 months. This benefit was only observed among patients with an obstructing tumour of the main bronchus. A higher rate of re-expansion of collapsed lung was observed in arm 2 (57%) compared to arm 1 (35%) (P=0.01). The inspiratory vital capacity (IVC) assessed 2 weeks after radiotherapy improved with 493 cm(3) in arm 2 and decreased 50 cm(3) in arm 1 (P=0.03). No difference was noted regarding the incidence of massive haemoptysis (13 vs. 15%). CONCLUSION: The addition of EBB to XRT in NSCLC is safe and provides higher rates of re-expansion of collapsed lung resulting in a transient lower levels of dyspnea. This beneficial effect was only observed among patients with obstructing tumours in the main bronchus.

Hepatic fibrin-ring granulomas in granulomatous hepatitis: report of four cases and review of the literature.

BACKGROUND: The differential diagnosis of hepatic fibrin-ring granulomas includes infective agents (Coxiella burneti, CMV, EBV,....), hypersensitivity to medication (allopurinol) and malignancy. METHODS: During a period of 6 months, four patients presented at our university hospital with a similar clinical picture of fever and abnormal liver tests, and fibrin-ring granulomas on liver biopsy. Clinical course, laboratory and imaging findings, and histopathological features were compared. RESULTS: Clinical manifestations, and laboratory and imaging findings were similar. Histopathological assessment of the hepatic fibrin-ring granulomas appeared not to be helpful in identifying the causative agent. Other histopathological features (e.g. sinusoidal rows of lymphocytes, eosinophilic polymorphonuclear infiltrate) were suggestive for the causative agent, yet conclusive identification was obtained by either serology (Q fever, CMV, EBV), or by exclusion with concomitant stop of medication (allopurinol). CONCLUSIONS: In the differential diagnosis of hepatic fibrin-ring granulomas, serologic titers remain the determining factor, since an infective agent is the most common cause. When hepatic fibrin-ring granulomas are present, other histopathological features may be helpful in making the differential diagnosis.

Massive haemoptysis after radiotherapy in inoperable non-small cell lung carcinoma: is endobronchial brachytherapy really a risk factor?

BACKGROUND AND PURPOSE: This retrospective study was conducted to investigate whether endobronchial brachytherapy (EBB) is a risk factor for massive haemoptysis in patients primarily treated by a combination of EBB and external irradiation (XRT) for NSCLC. MATERIALS AND METHODS: The records of 938 patients with inoperable NSCLC who were treated with XRT and/or EBB were reviewed. The patients were divided into five groups as follows: group XRT, treated by XRT alone (n = 421); group XRTelig, treated by XRT but eligible for EBB (n = 419); group XRTEBB, primarily treated with EBB+XRT (n = 62); group EBBrec, treated by EBB for recurrence after XRT (n = 23); and group EBB, treated by EBB alone (n = 13). EBB was delivered using HDR. Patients with bronchoscopy-proven endobronchial tumour in the proximal airways, i.e. the trachea, the main bronchus or lobar bronchus were considered eligible for EBB. RESULTS: One hundred one out of 938 patients (10.8%) died from massive haemoptysis. The incidence was 4.3% in group XRT, 13.1% in group XRTelig and 25.4% in group XRTEBB. The differences between groups XRT and XRTelig as well as between groups XRTelig and XRTEBB were statistically significant (P<0.01). The incidence of massive haemoptysis depended significantly on the fraction size of brachytherapy. When two fractions of 7.5 Gy or a single fraction of 10 Gy were used, 11.1% of the patients died from massive haemoptysis. However, when a single dose of 15 Gy was used, 47.8% died from massive haemoptysis. In the multivariate analysis, a single dose of 15 Gy EBB was the most important prognostic factor for massive haemoptysis. CONCLUSION: XRT+EBB as primary treatment for NSCLC does not lead to a higher risk of massive haemoptysis as compared to XRT alone when fraction sizes for EBB of 7.5 or 10 Gy are used. However, the risk of massive haemoptysis increases dramatically when a fraction size of 15 Gy is used.

Budesonide inhaled via Turbuhaler: a more effective treatment for asthma than beclomethasone dipropionate via Rotahaler.

BACKGROUND: Chlorofluorocarbon-propelled metered dose inhalers are facing a worldwide ban. Dry powder inhalers have been developed for the agents used in treatment of asthma. OBJECTIVE: Our objective was to compare the effects of two inhaled glucocorticosteroids in dry power inhalers: budesonide (delivered via Turbuhaler) and beclomethasone dipropionate (delivered via Rotahaler). METHODS: A randomized, crossover study with two steroid-treatment periods of 8 weeks. At the end of the study, the treatment with the inhaled steroid was stopped for 4 weeks. Sixteen adult patients with moderately severe asthma participated. Before the study all patients were treated with an inhaled steroid in a median dose of 0.60 mg/day (range 0.15-0.80); during the study they received 0.20 mg twice daily. Peak expiratory flow rate was measured twice daily at home throughout the study, lung function was assessed every fourth week and airway responsiveness was measured before and after each period. Preference concerning efficacy and inhaler type was assessed at the end of the study. RESULTS: Twelve patients completed the study. Lung function, airway responsiveness, and symptoms deteriorated significantly in the steroid-free washout period; this period had to be shortened in 5/12 patients. Mean morning peak expiratory flow was significantly higher during budesonide treatment than during beclomethasone dipropionate treatment, the difference being 17 L/min (95% C.I.: 2-32 L/min, P = .026). Airway responsiveness improved 1.1 doubling concentrations after budesonide treatment, but decreased 0.3 doubling concentrations after beclomethasone dipropionate treatment. The difference between the values after budesonide and beclomethasone dipropionate treatment was 1.4 doubling concentrations (95% C.I.: 0.4-2.4 doubling concentrations, P = .033). Forced expiratory flow in one second improved slightly more during budesonide than during beclomethasone treatment. The difference was 4.3% predicted (95% C.I.: -0.7-9.3%). Most patients reported budesonide Turbuhaler to be more effective (10 versus 0) and easier to use (11 versus 1) than beclomethasone dipropionate Rotahaler. CONCLUSIONS: As a consequence of the difference in local potency of the steroids and the fact that Turbuhaler deposits more drug particles in the lung than Rotahaler, budesonide inhaled via Turbuhaler appeared to be a more effective steroid formulation than beclomethasone dipropionate inhaled via Rotahaler.

Ectopic Cushing's syndrome in a patient with squamous cell carcinoma of the lung due to CRF-like production.

We present a patient with a poorly differentiated squamous cell carcinoma of the left lower lobe, who developed Cushing's syndrome. Adrenocorticotrophic hormone (ACTH) and cortisol levels in the blood were extremely elevated, but immunostaining for ACTH and corticotrophin releasing factor (CRF) of the primary tumour and metastases was negative. The ectopic Cushing's syndrome was probably caused by CRF-like production.

Coagulation/fibrinolysis balance and lung cancer.

Forty-eight patients with freshly diagnosed carcinoma of the lung (40 males, 8 females) were evaluated for a coagulation profile including activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, F VIII R:Ag, fibrin monomers (FM), thrombin-antithrombin-III complex (TAT-III), D-dimers and the platelet count. Thirty-eight patients had a normal aPTT and 37 patients a normal PT. None of the patients had clinical or laboratory indications of serious hemorrhage or thrombosis. On the other hand, high percentages of increased values were found for fibrinogen and F VIII R:Ag, which can be seen as prethrombotic factors. The very high percentages of elevated results for the FM, TAT-III and D-dimer are strongly indicative for low-grade coagulation activation with reactive fibrinolysis. Nevertheless, most lung cancer patients are able to maintain a normal or near normal hemostatic function. The results shown here are indicative of a coagulation and fibrinolysis equilibrium at an enhanced level and demonstrate why an unbalance between the two systems can result in thrombotic complications in (lung) cancer patients as earlier reported.

Ketotifen and methacholine-induced bronchospasm.

In a double-blind investigation the aspecific bronchus threshold was estimated by administration of methacholine to 16 young atopic patients with proven airways hyperreactivity (PC20 histamine less than or equal to 2 mg/ml. The influence of prolonged oral administration (12 weeks) of ketotifen (2 mg/day) on the bronchus threshold value has been studied. No significant elevation was found. It could be concluded that administration of ketotifen, even in prolonged administration, has no anticholinergic effects.

Measurement of the non-specific threshold stimulus for the bronchial tree by continuous monitoring of respiratory resistance using the oscillation method.

Bronchial hyperreactivity to various stimuli has been used as one of the diagnostic criteria of chronic obstructive lung diseases. We studied bronchial responsiveness to histamine in 30 patients with acute or chronic bronchitis, 28 patients with bronchial asthma and in 42 more patients with other lung diseases, using a new device--the Astograph--which yielded graphically a continuous dose-response curve of the respiratory resistance by the oscillation method during the inhalation of histamine diphosphate. The results of this method were compared with the results of FEV1 and FEF25-75 before and after the challenge procedure. An increase of the respiratory resistance (Ros) during the challenge test gave an indication of a decrease of FEV1. The increase of Ros and the decrease of FEV1 and FEF25-75 were most pronounced in the asthmatics. Not in all cases was there a correlation between the increase of Ros and the decrease of FEV1, possibly due to imperfections in the design of the equipment. We believe that the Ros measurement cannot be totally exchanged for the conventional method. The use of the Astograph alone cannot be recommended because of the false-negative reactions. A combination Astograph/Floop equipment is rather expensive, but it is the most rational and ideal. The test itself does not induce bronchoconstriction and is simple and time-saving. However, this procedure is not yet advised as a diagnostic tool for a challenge test with allergens in the diagnosis of bronchial asthma. A further investigation on the validity and security of such a provocation is still needed.