IFNgamma and TNFalpha account for a pro-clonogenic activity secreted by activated murine peritoneal macrophages

In the present study, we found that murine peritoneal macrophages elicited by BCG or Listeria monocytogenes release into the media an activity capable of stimulating the lung colonization as well as the expression of MHC class I antigens in B16 melanoma cells. A similar activity has previously been found in media conditioned by Corynebacterium parvum-elicited macrophages. Analysis by gel filtration chromatography of media conditioned by Corynebacterium parvum-, BCG- or Listeria monocytogenes-elicited macrophages revealed that the material responsible for the pro-clonogenic activity concentrated in chromatographic fractions corresponding to molecular weights (25 to 52 kDa) which are characteristic of certain cytokines. Thus, we challenged the various macrophage-conditioned media with polyclonal antibodies against IFNγand TNFα, and found that the macrophage pro-clonogenic activity was completely abolished in the presence of anti-IFNγantibodies, but only partially inhibited by anti-TNFαantibodies. This finding suggests a cooperative participation of the two cytokines to the pro-clonogenic activity of the media conditioned by Corynebacterium parvum-, BCG- or Listeria monocytogenes-elicited macrophages. This revised version was published online in July 2006 with corrections to the Cover Date.     

Biological properties associated with the enhanced lung-colonizing potential in a B16 murine melanoma line grown in a medium conditioned by syngeneic Corynebacterium parvum-elicited macrophages

A previous study by our laboratory showed that the peritoneal murine Corynebacterium parvum-elicited macrophages released into their growth medium an activity which enhanced the ability of B16-F10 melanoma cells to form experimental metastases in the lung of syngeneic mice. In the present study, we used a clone of B16-F10 line (F10-M3 cells) to investigate whether the increase in lung-colonizing potential due to the pro-clonogenic activity released by C. parvum-elicited macrophages was associated with biological properties characteristic of a metastatic phenotype. We have found that the pulmonary retention, growth rate in lung parenchyma, invasiveness through Matrigel, adhesiveness to IL-1-activated endothelium and MHC class I expression were increased in F10-M3 cells stimulated by the macrophage pro-clonogenic activity. By using an in vitro experimental protocol, the enhancement of lung-colonizing potential in the stimulated melanoma cells turned out to be a transient phenomenon as was the increase of invasiveness through Matrigel and the higher expression of MHC class I antigens. In conclusion, the melanoma cells stimulated by the pro-clonogenic activity released by C. parvum-elicited macrophages showed changes in biological parameters which are relevant to metastatic diffusion. These changes appeared as a temporary phenomenon which sustains the view that the metastatic phenotype represents a transient biological character influenced by host factors. This revised version was published online in July 2006 with corrections to the Cover Date.     

EphA2-mediated mesenchymal–amoeboid transition induced by endothelial progenitor cells enhances metastatic spread due to cancer-associated fibroblasts

Tumor progression is deeply influenced by epigenetic changes induced by tumor stroma. Cancer-associated fibroblasts (CAFs) have been reported to promote epithelial–mesenchymal transition in cancer cells, thereby enhancing their aggressiveness and stem-like properties. As CAFs are able to recruit endothelial progenitor cells (EPCs) to tumor site, we aim to investigate their interplay for prostate carcinoma progression. Both prostate CAFs and cancer cells actively recruit EPCs, known to affect tumor progression through increased vasculogenesis. EPCs synergize with CAFs to further promote epigenetic plasticity of cancer cells, through a mesenchymal-to-amoeboid transition. Indeed, after fibroblasts have engaged epithelial–mesenchymal transition in cancer cells, a further shift towards amoeboid motility is promoted by EPCs through contact-mediated triggering of the bidirectional ephrinA1/EphA2 signaling. The activation of ephrinA1 reverse pathway enhances EPC-induced neo-vascularization, thus promoting tumor growth, while EphA2 forward signaling elicits mesenchymal–amoeboid transition in cancer cells, favoring their adhesion to endothelium, transendothelial migration, and lung metastatic colonization. We therefore underscore that the metastatic advantage given by tumor microenvironment embraces different motility strategies and propose EphA2-targeted tools as useful adjuvants in anti-metastatic treatments.     

Physical injuries caused by a transient loss of consciousness: main clinical characteristics of patients and diagnostic contribution of carotid sinus massage.

AIMS: To evaluate the prevalence and the characteristics of secondary trauma among patients referred to the emergency department (ED) for a transient loss of consciousness (TLOC). METHODS AND RESULTS: Over a 24 months period, all the patients referred to our ED for a TLOC were evaluated according to the ESC Guidelines on Syncope and enrolled in the study. Among 1253 consecutive patients with TLOC (1114 with a true syncope and 139 with a non-syncopal condition) 365 (29.1%) reported a trauma, in 59 cases (4.7%) severe. The frequency and the characteristics of trauma did not differ among the two main categories of TLOC. Out of 54 patients with syncope and a severe trauma, 20 (37%) had a definite diagnosis after a guidelines-based initial evaluation, and further 17 (31.5%) during the hospital course. Among these latter, carotid sinus syndrome was by far the most common diagnosis. CONCLUSION: Among patients referred to the ED for a TLOC secondary trauma is a common complication, whose characteristics are of little utility to discover the specific cause of the symptom. For older patients with syncope complicated by a severe trauma carotid sinus massage should be the first diagnostic manoeuvre to be undertaken after a non-diagnostic initial evaluation.     

Arginine metabolism in tumor-associated macrophages in cutaneous malignant melanoma: evidence from human and experimental tumors

Tumor-associated macrophages (TAMs) may elicit contrasting effects on tumor growth, depending on their biological activities. Macrophages use arginine either to synthesize nitric oxide (NO) through the inducible NO synthase (iNOS) or to produce ornithine through arginase activity. Although the effects of NO are primarily cytotoxic, production of ornithine may promote tumor cell proliferation. Thus, iNOS/arginase balance in TAMs may be crucial in tumor progression. The aim of this study was (a) to explore iNOS and arginase expression in TAMs associated with human melanoma at different stages of tumor progression and (b) to explore whether melanoma cells influence iNOS and/or arginase expression in TAMs under basal condition and in the presence of interferon gamma and/or lipopolysaccharide. Immunohistochemical analyses performed on tissue sections from in situ melanoma, invasive melanoma of different pT categories, and metastatic melanoma revealed that (a) the percentage of iNOS-positive TAMs was significantly higher in in situ and thin melanomas in comparison with more advanced, thicker tumors; (b) the percentage of arginase-positive TAMs did not change among the pT categories analyzed; and (c) the percentage of iNOS-positive TAMs was greater than that of arginase-positive TAMs in peritumoral and intratumoral locations of thin melanomas (pT1). Moreover, by the use of an in vitro experimental protocol represented by B16 murine melanoma cells cocultivated with inflammatory macrophages, we found that melanoma cells stimulate iNOS expression and NO production in macrophages. In conclusion, our in vivo and in vitro results suggest that, mainly in early melanoma lesions, iNOS prevails over arginase in TAMs, a phenomenon possibly stimulated by contact with tumor cells. However, macrophages stimulated by murine melanoma cells secreted a level of NO compatible with an antitumor activity only in the presence of interferon gamma.     

uPAR Controls Vasculogenic Mimicry Ability Expressed by Drug-Resistant Melanoma Cells

Malignant melanoma is a highly aggressive skin cancer characterized by an elevated grade of tumor cell plasticity. Such plasticity allows adaptation of melanoma cells to different hostile conditions and guarantees tumor survival and disease progression, including aggressive features such as drug resistance. Indeed, almost 50% of melanoma rapidly develop resistance to the BRAFV600E inhibitor vemurafenib, with fast tumor dissemination, a devastating consequence for patients’ outcomes. Vasculogenic mimicry (VM), the ability of cancer cells to organize themselves in perfused vascular-like channels, might sustain tumor spread by providing vemurafenibresistant cancer cells with supplementary ways to enter into circulation and disseminate. Thus, this research aims to determine if vemurafenib resistance goes with the acquisition of VM ability by aggressive melanoma cells, and identify a driving molecule for both vemurafenib resistance and VM. We used two independent experimental models of drug-resistant melanoma cells, the first one represented by a chronic adaptation of melanoma cells to extracellular acidosis, known to drive a particularly aggressive and vemurafenib-resistant phenotype, the second one generated with chronic vemurafenib exposure. By performing in vitro tube formation assay and evaluating the expression levels of the VM markers EphA2 and VE-cadherin by Western blotting and flow cytometer analyses, we demonstrated that vemurafenib-resistant cells obtained by both models are characterized by an increased ability to perform VM. Moreover, by exploiting the CRISPR-Cas9 technique and using the urokinase plasminogen activator receptor (uPAR) inhibitor M25, we identified uPAR as a driver of VM expressed by vemurafenib-resistant melanoma cells. Thus, uPAR targeting may be successfully leveraged as a new complementary therapy to inhibit VM in drug-resistant melanoma patients, to counteract the rapid progression and dissemination of the disease.     

Past,Present, and Future of Postgraduate Nursing Education in Radiology at the National Institute of Radiological Sciences in Japan

The National Institute of Radiological Sciences in Japan has offered a postgraduate training course for nurses in radiological medicine since 1994 because radiation protection and radiation effects have not been included as subjects in the official guidelines for nursing schools but are strongly required as important knowledge for nurses. By 2017, the training program had been conducted 102 times, and 3230 trainees had participated. To examine if participants thought there was a need for training, a questionnaire survey was carried out after the course, targeting 397 trainees who participated in the course from 2015 to 2017. Their average age was 39.2 years. Among them, 81.9% were general nurses, 17.6% held an administrative position, 44.8% had 1-5 years of experience in radiation medicine, and 83.7% had received training in radiation in the workplace or elsewhere before participating in the course. Of all, 91.7% participated to obtain knowledge of radiation basics and 65.2% participated to acquire the capability to respond to patients' questions. The average evaluation score of the training course was 90.2 out of 100. These findings indicate that presently, there is still a high demand for postgraduate training of nurses in radiological medicine and that an advanced course needs to be offered in the future.     

The homopolymerization of 2,3-dimethyl-1,3-butadiene and the copolymerization of 1,3-butadiene/2,3-dimethyl-1,3-butadiene using the catalyst system AlEt2Cl-Co(acac)2. A structural investigation of the products

The homopolymerization of 2,3-dimethyl-1,3-butadiene with the catalyst system AlEt₂Cl-Co(acac)₂ affords polymers consisting of about 81% cis-1,4-units and 19% 1,2-units. The copolymerization of 1,3-butadiene/2,3-dimethyl-1,3-butadiene using the same system is of the ideal type and the composition of the copolymers is practically identical with that of the monomer mixture. The structure of the copolymers depends on their composition. The butadiene units, which are more than 95% cis-1,4 in the homopolymer, become partially 1,2 in the copolymers; their amount increases with increasing dimethylbutadiene content. Conversely, the fraction of dimethylbutadiene units with 1,2-structure decreases in the copolymers with increasing butadiene content. In the copolymers containing more than 50% of butadiene, the dimethylbutadiene units are practically all cis-1,4. The analysis of sequence distribution shows that the 1,2-butadiene units in the copolymers are not randomly distributed but are mostly adjacent to dimethylbutadiene units. The results obtained with dimethylbutadiene are compared with those reported for the homopolymerization of isoprene and the copolymerization of isoprene/butadiene using the same catalyst system.     

Polymerization of 4‐Methyl‐1,3‐pentadiene with Catalysts Based on Cyclopentadienyl Titanium Chlorides: Effect of anti/syn Isomerism of the Allylic Group on the Chemoselectivity and the Role of Backbiting Coordination in 1,3‐Diene Polymerization

Summary: Homopolymerization of 4‐methyl‐1,3‐pentadiene (MP) and copolymerization of 4‐methyl‐1,3‐pentadiene with alkenes (ethylene, 1‐pentene, 4‐methyl‐1‐pentene) were performed to investigate the effect of the so‐called backbiting coordination on the chemoselectivity of 1,3‐diene polymerization. Three homogeneous catalyst systems were used: CpTiCl₃‐MAO, Cp₂TiCl₂‐MAO and Cp₂TiCl‐MAO. Backbiting coordination is possible with the first catalyst, but not with the other two. The three catalysts gave similar results, which indicates that backbiting has no effect on the polymerization chemoselectivity, contrary to what has been reported in recent literature. An interpretation is presented for the formation of 1,4 units in MP/alkene copolymers. This interpretation is based on the fact that allyl groups have predominantly a syn configuration in MP homopolymerization, whereas allyl groups of anti configuration are formed in MP/alkene copolymerization. The role of backbiting in diene polymerization is discussed.

The effect of anti/syn isomerism on the chemoselectivity in the different polymerizations.