Glucosylceramide Synthase Is Involved in Development of Invariant Natural Killer T Cells

Invariant natural killer T (iNKT) cells represent a unique population of CD1d-restricted T lymphocytes expressing an invariant T cell receptor encoded by Vα14-Jα18 and Vα24-Jα18 gene segments in mice and humans, respectively. Recognition of CD1d-loaded endogenous lipid antigen(s) on CD4/CD8-double positive (DP) thymocytes is essential for the development of iNKT cells. The lipid repertoire of DP thymocytes and the identity of the decisive endogenous lipid ligands have not yet been fully elucidated. Glycosphingolipids (GSL) were implicated to serve as endogenous ligands. However, further in vivo investigations were hampered by early embryonal lethality of mice deficient for the key GSL-synthesizing enzyme glucosylceramide (GlcCer) synthase [GlcCer synthase (GCS), EC 2.4.1.80]. We have now analyzed the GSL composition of DP thymocytes and shown that GlcCer represented the sole neutral GSL and the acidic fraction was composed of gangliosides. Furthermore, we report on a mouse model that by combination of Vav-promoter-driven iCre and floxed GCS alleles (VavCreGCSf/f) enabled an efficient depletion of GCS-derived GSL very early in the T cell development, reaching a reduction by 99.6% in DP thymocytes. Although the general T cell population remained unaffected by this depletion, iNKT cells were reduced by approximately 50% in thymus, spleen, and liver and showed a reduced proliferation and an increased apoptosis rate. The Vβ-chains repertoire and development of iNKT cells remained unaltered. The GSL-depletion neither interfered with expression of CD1d, SLAM, and Ly108 molecules nor impeded the antigen presentation on DP thymocytes. These results indicate that GlcCer-derived GSL, in particular GlcCer, contribute to the homeostatic development of iNKT cells

A quick, simplified approach to the evaluation of combustion rate from an internal combustion engine indicator diagram

In this paper a simplified procedure of an internal combustion engine in-cylinder pressure record analysis has been presented The method is very easy for programming and provides quick evaluation of the gas temperature and the rate of combustion. It is based on the consideration proposed by Hohenberg and Killman, but enhances the approach by involving the rate of heat transferred to the walls that was omitted in the original approach. It enables the evaluation of the complete rate Of heat released by combustion (often designated as gross heat release rate or fuel chemical energy release rate), not only the rate of heat transferred to the gas (which is often designated as net heat release rate). The accuracy of the method has been also analyzed and it is shown that the errors caused by the simplifications in the model are very small, particularly if the crank angle step is also small A several practical applications on recorded pressure diagrams taken from both spark ignition and compression ignition engine are presented as well

Angiotensin inhibition enhances drug delivery and potentiates chemotherapy by decompressing tumour blood vessels

Cancer and stromal cells actively exert physical forces (solid stress) to compress tumour blood vessels, thus reducing vascular perfusion. Tumour interstitial matrix also contributes to solid stress, with hyaluronan implicated as the primary matrix molecule responsible for vessel compression because of its swelling behaviour. Here we show, unexpectedly, that hyaluronan compresses vessels only in collagen-rich tumours, suggesting that collagen and hyaluronan together are critical targets for decompressing tumour vessels. We demonstrate that the angiotensin inhibitor losartan reduces stromal collagen and hyaluronan production, associated with decreased expression of profibrotic signals TGF-β1, CCN2 and ET-1, downstream of angiotensin-II-receptor-1 inhibition. Consequently, losartan reduces solid stress in tumours resulting in increased vascular perfusion. Through this physical mechanism, losartan improves drug and oxygen delivery to tumours, thereby potentiating chemotherapy and reducing hypoxia in breast and pancreatic cancer models. Thus, angiotensin inhibitors—inexpensive drugs with decades of safe use—could be rapidly repurposed as cancer therapeutics.National Cancer Institute (U.S.) (Grant P01-CA080124)National Cancer Institute (U.S.) (Grant R01-CA126642)National Cancer Institute (U.S.) (Grant R01-CA085140)National Cancer Institute (U.S.) (Grant R01-CA115767)National Cancer Institute (U.S.) (Grant R01-CA098706)United States. Dept. of Defense. Breast Cancer Research Program (Innovator Award W81XWH-10-1-0016)Lustgarten Foundation (Dana-Farber Cancer Institute/David H. Koch Institute for Integrative Cancer Research at MIT Bridge Project Grant

Impact of concomitant aortic regurgitation on long-term outcome after surgical aortic valve replacement in patients with severe aortic stenosis

<p>Abstract</p> <p>Background</p> <p>Prognostic value of concomitant aprtic regurgitation (AR) in patients operated for severe aortic stenosis (AS) is not clarified. The aim of this study was to prospectively examine the impact of presence and severity of concomitant AR in patients operated for severe AS on long-term functional capacity, left ventricular (LV) function and mortality.</p> <p>Methods</p> <p>Study group consisted of 110 consecutive patients operated due to severe AS. The patients were divided into AS group (56 patients with AS without AR or with mild AR) and AS+AR group (54 patients with AS and moderate, severe or very severe AR). Follow-up included clinical examination, six minutes walk test (6MWT) and echocardiography 12 and 104 months after AVR.</p> <p>Results</p> <p>Patients in AS group had lower LV volume indices throughout the study than patients in AS+AR group. Patients in AS group did not have postoperative decrease in LV volume indices, whereas patients in AS+AR group experienced decrease in LV volume indices at 12 and 104 months. Unlike LV volume indices, LV mass index was significantly lower in both groups after 12 and 104 months as compared to preoperative values. Mean LVEF remained unchanged in both groups throughout the study. NYHA class was improved in both groups at 12 months, but at 104 months remained improved only in patients with AS. On the other hand, distance covered during 6MWT was longer at 104 months as compared to 12 months only in AS+AR group (p = 0,013), but patients in AS group walked longer at 12 months than patients in AS+AR group (p = 0,002). There were 30 deaths during study period, of which 13 (10 due to cardiovascular causes) in AS group and 17 (12 due to cardiovascular causes) in AS+AR group. Kaplan-Meier analysis showed that the survival probability was similar between the groups. Multivariate analysis identified diabetes mellitus (beta 1.78, p = 0.038) and LVEF < 45% (beta 1.92, p = 0.049) as the only independent predictor of long-term mortality.</p> <p>Conclusion</p> <p>Our data indicate that the preoperative presence and severity of concomitant AR has no influence on long-term postoperative outcome, LV function and functional capacity in patients undergoing AVR for severe AS.</p

Spectroscopic ellipsometry and polarimetry for materials and systems analysis at the nanometer scale: state-of-the-art, potential, and perspectives

This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for the characterization of materials and related systems and devices at the nanoscale. These techniques include spectroscopic ellipsometry, polarimetry, and reflectance anisotropy. We give an overview of the various ellipsometry strategies for the measurement and analysis of nanometric films, metal nanoparticles and nanowires, semiconductor nanocrystals, and submicron periodic structures. We show that ellipsometry is capable of more than the determination of thickness and optical properties, and it can be exploited to gain information about process control, geometry factors, anisotropy, defects, and quantum confinement effects of nanostructures

Biomarker and micropetrographic investigations of coal from the Krepoljin Brown Coal Basin Serbia

We investigated early diagenetic processes of the extractable organic matter from the Miocene freshwater sequence, which consists of coal fragments in clays, sandstones and shales alternating with continuous brown coal layers. We examined eight coals, thirteen sediments and three non-coaly underground layers. The molecular assemblages of the identified aliphatic hydrocarbons in the Krepoljin Basin reflect the abundance of plant taxa as precursors or participants in the early diagenetic stage. The data provide insight into the conditions prevailing in the lakes and bogs during early diagenesis. The dominance of diterpanes indicates that the prevalent of the organic matter was of gymnosperous origin. The hopanoid contents are considered to reflect microbial activity. That the organic matter in the Miocene Krepoljin Coal Basin is immature was confirmed by the presence of biolipids such as beta beta-hopanes, C-27 17 beta (H)-trisnorhopane. Saturated and aromatized abietanes, pimaranes and phyllocladanes, the most abundant compounds in all samples, indicate a predominantly higher plant input related to the Coniferous group, but identification of the individual plant families was not possible. beta-Amyrin and other triterpenoid-derived triaromatic and triaromatic C-ring cleaved hydrocarbons with triterpenoid structures are thought to be characteristic for angiosperms. Unsaturated compounds, Delta(2)-triterpanes, early intermediaries in the diagenetic transformation of angiosperms also indicate a low degree of sediment maturity. Crown Copyrigh

Transcriptional profiling of dendritic cells matured in different osmolarities

Tissue-specific microenvironments shape the fate of mononuclear phagocytes [1–3]. Interstitial osmolarity is a tissue biophysical parameter which considerably modulates the phenotype and function of dendritic cells [4]. In the present report we provide a detailed description of our experimental workflow and bioinformatic analysis applied to our gene expression dataset (GSE72174), aiming to investigate the influence of different osmolarity conditions on the gene expression signature of bone marrow-derived dendritic cells. We established a cell culture system involving murine bone marrow cells, cultured under different NaCl-induced osmolarity conditions in the presence of the dendritic cell growth factor GM-CSF. Gene expression analysis was applied to mature dendritic cells (day 7) developed in different osmolarities, with and without prior stimulation with the TLR2/4 ligand LPS. Keywords: Dendritic cells, Salt hyperosmolarity, Gene expression analysi

Molecular pathology of thymomas: implications for diagnosis and therapy

Thymomas exhibit a unique genomic landscape, comprising the lowest on average total mutational burden among adult human cancers; a unique point mutation in the GTF2I gene in WHO type A and AB thymomas (and rarely others); almost unique KMT2A-MAML2 translocations in rare WHO type B2 and B3 thymomas; a unique YAP1-MAML2 translocation in almost all metaplastic thymomas; and unique miRNA profiles in relation to GTF2I mutational status and WHO histotypes. While most thymomas can be diagnosed solely on the basis of morphological features, mutational analyses can solve challenging differential diagnostic problems. No molecular biomarkers have been identified that predict the response of unresectable thymomas to chemotherapy or agents with known molecular targets. Despite the common and strong expression of PDL1 in thymomas, immune checkpoint inhibitors are rarely applicable due to the poor predictability of common, life-threatening autoimmune side effects that are related to the unrivaled propensity of thymomas towards autoimmunity