Isothermal and non‐isothermal crystallization of poly(L‐lactic acid)/poly(butylene terephthalate) blends

Isothermal and non‐isothermal crystallization kinetics of poly(l ‐lactic acid)/poly(butylene terephthalate) (PLLA/PBT) blends containing PLLA as major component is detailed in this contribution. PLLA and PBT are not miscible, but compatibility of the polymer pair is ensured by interactions between the functional groups of the two polyesters, established upon melt mixing. Crystal polymorphism of the two polyesters is not influenced by blending, as probed by wide‐angle X‐ray analysis. The addition of PLLA does not affect the temperature range of crystallization kinetics of PBT, nor the crystallinity level attained when the blends are cooled from the melt at constant rate. Conversely, PBT favors crystallization of the biodegradable polyester. The addition of PBT results in an anticipated onset of crystallization of PLLA during cooling at a fixed rate, with a sizeable enhancement of the crystal fraction. Isothermal crystallization analysis confirmed the faster crystallization rate of PLLA in the presence of PBT. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40372.     

In vitro haematic proteins adsorption and cytocompatibility study on acrylic copolymer to realise coatings for drug-eluting stents

In the present paper, a preliminary in vitro analysis of biocompatibility of newly-synthesised acrylic copolymers is reported. In particular, with the aim to obtain coatings for drug-eluting stents, blood protein absorption and cytocompatibility were studied. For protein absorption tests, bovine serum albumin and bovine plasma fibrinogen were considered. Cytocompatibility was tested using C2C12 cell line as model, analysing the behaviour of polymeric matrices and of drug-eluting systems, obtained loading polymeric matrices with paclitaxel, an anti-mitotic drug, in order to evaluate the efficacy of a pharmacological treatment locally administered from these materials. Results showed that the amount of albumin absorbed was greater than the amount of fibrinogen (comprised in the range of 70%–85% and 10%–22% respectively) and it is a good behaviour in terms of haemocompatibility. Cell culture tests showed good adhesion properties and a relative poor proliferation. In addition, a strong effect related to drug elution and a correlation with the macromolecular composition were detected. In this preliminary analysis, tested materials showed good characteristics and can be considered possible candidates to obtain coatings for drug-eluting stents.     

Bystander apoptosis triggers dendritic cell maturation and antigen-presenting function

Physiologic cell death via apoptosis occurs without inflammation or autoimmunity. Here, we investigated the outcome of the interaction of apoptotic cells with dendritic cells (DCs), which are potent professional APCs. DCs internalized apoptotic cells and processed them for presentation to both MHC class I- and class II-restricted T cells with an efficiency that was dependent upon the number of apoptotic cells. The latter event was accompanied by the autocrine/paracrine secretion of IL-1beta and TNF-alpha, with eventual DC maturation. High numbers of apoptotic cells, mimicking a failure of their in vivo clearance, are therefore sufficient to trigger DC maturation and the presentation of intracellular Ags from apoptotic cells, even in the absence of exogenous "danger" signals.     

A Statistical Mechanic View of Macro-dynamics in Economics

In this study, based on a statistical mechanic perspective, some technical insights for macroeconomic analysis are presented with regard to (1) “modeling the behaviour of a many-interacting-heterogeneous agents system through the analysis of fractions’ stochastic dynamics over a state space” (Delli Gatti and Gallegati, Eterogeneità degli agenti economici ed interazione sociale: teorie e verifiche empiriche, 2005) and (2) suggesting a new microfoundation method based on jump Markov processes to mimic fluctuation dynamics of macro variables (Aoki, New approaches to macroeconomic modeling, 1996; Aoki, Modeling aggregate behaviour and fluctuations in economics, 2002; Aoki and Yoshikawa, Reconstructuring macroeconomics. A perspective from statistical physics and combinatorial stochastic processes, 2006). The main aim is to review and to describe how the statistical mechanic methodology provides systematic methods to solve master equation problems to be applied in macroscopic dynamics analysis in economics. The results are achieved in terms of a mean field system of equations to model average and volatility of a macroscopic quantity. By means of a macroscopic ordinary differential equation, the drift component is detached and, by means of a Fokker–Planck equation, the spread component around such a deterministic path is derived.     

Different risks of thrombosis in four coagulation defects associated with inherited thrombophilia: a study of 150 families

Deficiency of the naturally occurring anticoagulant proteins, such as antithrombin, protein C and protein S, and activated protein C resistance due to the factor V Leiden gene mutation is associated with inherited thrombophilia. So far, no direct comparison of the thrombotic risk associated with these genetic defects is available. In this study, we wish to compare the lifetime probability of developing thrombosis, the type of thrombotic symptoms, and the role of circumstantial triggering factors in 723 first- and second-degree relatives of 150 index patients with different thrombophilic defects. We found higher risks for thrombosis for subjects with antithrombin (risk ratio 8.1, 95% confidence interval [CI], 3.4 to 19.6), protein C (7.3, 95% CI, 2.9 to 18.4) or protein S deficiency (8.5, 95% CI, 3. 5 to 20.8), and factor V Leiden (2.2, 95% CI, 1.1 to 4.7) than for individuals with normal coagulation. The risk of thrombosis for subjects with factor V Leiden was lower than that for those with all three other coagulation defects (0.3, 95% CI, 0.1 to 1.6), even when arterial and superficial vein thromboses were excluded and the analysis was restricted to deep vein thrombosis (0.3, 95% CI, 0.2 to 0.5). No association between coagulation defects and arterial thrombosis was found. The most frequent venous thrombotic manifestation was deep vein thrombosis with or without pulmonary embolism (90% in antithrombin, 88% in protein C, 100% in protein S deficiency, and 57% in factor V Leiden), but a relatively mild manifestation such as superficial vein thrombosis was common in factor V Leiden (43%). There was a predisposing factor at the time of venous thromboembolism in approximately 50% of cases for each of the four defects. In conclusion, factor V Leiden is associated with a relatively small risk of thrombosis, lower than that for antithrombin, protein C, or protein S deficiency. In addition, individuals with factor V Leiden develop less severe thrombotic manifestations, such as superficial vein thrombosis.     

Psoriasiform id reaction in tinea corporis

A case of tinea corporis due to Microsporum canis followed by a scattered psoriasiform eruption is reported. The nature, clinical features and pathogenesis of the dermatophytid are discussed.     

Tumor Extracellular Matrix Stiffness Promptly Modulates the Phenotype and Gene Expression of Infiltrating T Lymphocytes

The immune system is a fine modulator of the tumor biology supporting or inhibiting its progression, growth, invasion and conveys the pharmacological treatment effect. Tumors, on their side, have developed escaping mechanisms from the immune system action ranging from the direct secretion of biochemical signals to an indirect reaction, in which the cellular actors of the tumor microenvironment (TME) collaborate to mechanically condition the extracellular matrix (ECM) making it inhospitable to immune cells. TME is composed of several cell lines besides cancer cells, including tumor-associated macrophages, cancer-associated fibroblasts, CD4⁺ and CD8⁺ lymphocytes, and innate immunity cells. These populations interface with each other to prepare a conservative response, capable of evading the defense mechanisms implemented by the host’s immune system. The presence or absence, in particular, of cytotoxic CD8⁺ cells in the vicinity of the main tumor mass, is able to predict, respectively, the success or failure of drug therapy. Among various mechanisms of immunescaping, in this study, we characterized the modulation of the phenotypic profile of CD4⁺ and CD8⁺ cells in resting and activated states, in response to the mechanical pressure exerted by a three-dimensional in vitro system, able to recapitulate the rheological and stiffness properties of the tumor ECM.     

Human Chromosome 18 and Acrocentrics: A Dangerous Liaison

The presence of thousands of repetitive sequences makes the centromere a fragile region subject to breakage. In this study we collected 31 cases of rearrangements of chromosome 18, of which 16 involved an acrocentric chromosome, during genetic screening done in three centers. We noticed a significant enrichment of reciprocal translocations between the centromere of chromosome 18 and the centromeric or pericentromeric regions of the acrocentrics. We describe five cases with translocation between chromosome 18 and an acrocentric chromosome, and one case involving the common telomere regions of chromosomes 18p and 22p. In addition, we bring evidence to support the hypothesis that chromosome 18 preferentially recombines with acrocentrics: (i) the presence on 18p11.21 of segmental duplications highly homologous to acrocentrics, that can justify a NAHR mechanism; (ii) the observation by 2D-FISH of the behavior of the centromeric regions of 18 respect to the centromeric regions of acrocentrics in the nuclei of normal subjects; (iii) the contact analysis among these regions on published Hi-C data from the human lymphoblastoid cell line (GM12878).