Surface properties and cell response of low metal ion release Ti-6Al-7Nb alloy after multi-step chemical and thermal treatments

Ti-6Al-7Nb samples treated by innovative multi-step chemical and thermal processes were characterized in order to evaluate their surface properties and cell interaction. The main object was to asses if the treatments were effective in order to obtain a surface presenting at the same time bone-like apatite induction ability, low metal ion release, good cell response and high protein binding. The morphology, crystallographic structure, porosity and wettability of the treated materials were investigated, as well as their interaction with simulated body fluid during soaking for different times. Cytotoxicity, protein adsorption tests and in vitro fibroblast and osteoblast-like cell cultures were also performed.     

A comparison of different sealants preventing demineralization around brackets

Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie - Aim of the study was to compare how six different sealants resisted thermal, mechanical, and chemical loading in vitro....     

Switching antipsychotic medication to aripiprazole: position paper by a panel of Italian psychiatrists

Introduction: Patients with schizophrenia or bipolar disorder treated with antipsychotic medication can frequently experience lack of efficacy and persistent side-effects, so much so that switching from one antipsychotic to another with a different side-effect profile has become a recommended strategy for improving the tolerability and safety of long-term antipsychotic treatment. Aripiprazole is an atypical antipsychotic with proven efficacy in schizophrenia and bipolar I disorder, with a pharmacological profile distinct from other available antipsychotics and a side-effect profile that is different from other agents in the class; these characteristics make it a possible alternative in patients requiring a change in antipsychotic treatment due to lack of efficacy or persistent side-effects.

Areas covered: A panel of Italian experts in psychiatry met to discuss the appropriateness of current strategies for the switch to aripiprazole in patients with schizophrenia or bipolar disorder once a clinician has decided to adopt this choice and also to propose alternate strategies where required. The strategies for the switch to aripiprazole presented in this position paper consider various scenarios encountered in clinical practice, highlight the importance of tapering the prior antipsychotic based on its pharmacological characteristics and provide detailed guidance throughout the entire switching process. Literature searches were conducted using the PubMed database and the search strategy (aripiprazole and switching); additional references were added from the reference lists of the papers obtained and also from the authors’ knowledge of the topic.

Expert opinion: Few studies have addressed the indications for antipsychotic switching and the best practical strategies to achieve the desired goal in the clinical practice setting. Studies on antipsychotic switching should clarify why, when and how a switch should be done. The results should standardize the reasons for switching an antipsychotic, assess the optimal time to switch and evaluate the best ways to switch. Both clinical and pharmacological factors should be considered when a patient needs to switch antipsychotics, and specific guidelines for antipsychotic switching that address all these factors are needed.     

Acute Kidney Injury Following Aortic Valve Replacement in Patients Without Chronic Kidney Disease

BackgroundThe data on acute kidney injury (AKI) in patients without chronic kidney disease (CKD) after transcatheter aortic valve replacement (TAVR) are limited. The study sought to compare the incidence of AKI and its impact on 5-year mortality after TAVR and surgical aortic valve replacement (SAVR) in patients without CKD.MethodsThis registry included data from 6463 consecutive patients who underwent TAVR or SAVR. CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m². AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. For sensitivity analysis, propensity-score matching between TAVR and SAVR was performed.ResultsThe study included 4555 consecutive patients (TAVR, n = 1215 and SAVR, n = 3340) without CKD. Propensity-score matching identified 542 pairs. Patients who underwent TAVR had a significantly lower incidence of AKI in comparison to those who underwent SAVR (unmatched 4.7% vs 16.4%, P < 0.001, multivariable analysis: odds ratio, 0.29, 95% confidence interval [CI], 0.20-0.41; matched 5.9% vs 19.0%, P < 0.001). Patients with AKI had significantly increased 5-year mortality compared with those without AKI (unmatched 36.0% vs 19.1%, log-rank P < 0.001; matched 36.3% vs 24.0%, log-rank P < 0.001). The adjusted hazard ratios for 5-year mortality were 1.58 (95% CI, 1.20-2.08) for AKI grade 1, 3.27 (95% CI, 2.09-5.06) for grade 2, and 4.82 (95% CI, 2.93-8.04) for grade 3.ConclusionsTAVR in patients without CKD was associated with a significantly less frequent incidence of AKI compared with SAVR. AKI significantly increased the risk of 5-year mortality after either TAVR or SAVR, and increasing severity of AKI was incrementally associated with 5-year mortality.     

Effects of CRH, ACTH and the corticostatin HP-4 on the spontaneous NK cell activity and susceptibility to endogenous modifiers

Natural killer (NK) cells are mononuclear leukocytes which are thought to play an important role in immunosurveillance; in the elderly a progressive reduction occurs both of their spontaneous activity and of their responsiveness to positive modulators such as immune interferon (IFN-y) and interleukin-2 (IL-2). NK cells represent also a reliable model to study immunomodulatory properties of the hypothalamic-pituitary-adrenal (HPA) system, since cortisol (F) is a well defined inhibitor of their activity whereas proopiomelanocortin (POMC)-derived peptides may counteract this effect. Corticostatins (CS)-defensins are a family of peptides recently purified from cells capable of phagocytic activity; they are able to inhibit the steroidogenic activity of ACTH and to enhance internalization and/or killing of intracellular pathogens. We have investigated the effects in vitro of corticotropin releasing hormone (CRH), ACTH and CS HP-4 on human NK cell activity. Peripheral blood mononuclear (PBM) cells from healthy donors were incubated with CRH (10(-14)-10(-11) M). ACTH (10(-12)-10(-8) M) and HP-4 (10(-10)-10(-8) M) in the presence or absence of F (10(-6) M) or IFN-y (325 IU//ml) or IL-2 (25 IU/ml). NK cell activity was measured in a 4-h cytotoxic assay using K562 cells as a target. CRH was able to significantly reduce the spontaneous and IL-2-induced NK activity and to significantly potentiate the F-dependent inhibition. ACTH was per se ineffective on the spontaneous NK activity, but was able to augment the enhancing effects of IFN-y and IL-2, and to reduce the degree of inhibition obtainable with the glucocorticoid. HP-4 was able to enhance the F-dependent inhibition of PBM preparations. Our results are consistent with an immunomodulatory role for CRH, ACTH and CS, specially in conditions of high concentrations of glucocorticoids. Since in elderly has been demonstrated a condition of hypercortisolism, we suggest that complex steroid-peptides interactions are involved in the net effect of HPA axis on immune functions in senescence, and that such interactions involve paracrine/autocrine CS.