839 research outputs found

    Coarsening Strategies for Unstructured Multigrid Techniques with Application to Anisotropic Problems

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    Over the years, multigrid has been demonstrated as an efficient technique for solving inviscid flow problems. However, for viscous flows, convergence rates often degrade. This is generally due to the required use of stretched meshes (i.e., the aspect ratio AR = Δy/Δx < < 1) in order to capture the boundary layer near the body. Usual techniques for generating a sequence of grids that produce proper convergence rates on isotropic meshes are not adequate for stretched meshes. This work focuses on the solution of Laplace's equation, discretized through a Galerkin finite-element formulation on unstructured stretched triangular meshes. A coarsening strategy is proposed and results are discussed

    Early Investigations and Recent Advances in Intraperitoneal Immunotherapy for Peritoneal Metastasis.

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    Peritoneal metastasis (PM) is an advanced stage malignancy largely refractory to modern therapy. Intraperitoneal (IP) immunotherapy offers a novel approach for the control of regional disease of the peritoneal cavity by breaking immune tolerance. These strategies include heightening T-cell response and vaccine induction of anti-cancer memory against tumor-associated antigens. Early investigations with chimeric antigen receptor T cells (CAR-T cells), vaccine-based therapies, dendritic cells (DCs) in combination with pro-inflammatory cytokines and natural killer cells (NKs), adoptive cell transfer, and immune checkpoint inhibitors represent significant advances in the treatment of PM. IP delivery of CAR-T cells has shown demonstrable suppression of tumors expressing carcinoembryonic antigen. This response was enhanced when IP injected CAR-T cells were combined with anti-PD-L1 or anti-Gr1. Similarly, CAR-T cells against folate receptor α expressing tumors improved T-cell tumor localization and survival when combined with CD137 co-stimulatory signaling. Moreover, IP immunotherapy with catumaxomab, a trifunctional antibody approved in Europe, targets epithelial cell adhesion molecule (EpCAM) and has shown considerable promise with control of malignant ascites. Herein, we discuss immunologic approaches under investigation for treatment of PM

    Auto-inhibitory effects of an IQ motif on protein structure and function

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    The denuded IQ2 domain, i.e. myosin heavy chain not associated with regulatory light chains, exerts an inhibitory effect on myosin ATPase activity. In this study, we elaborated a structural explanation for this auto-inhibitory effect of IQ2 on myosin function. We employed analytical ultracentrifugation, circular dichroism, and surface plasmon resonance spectroscopy to investigate structural and functional properties of a myosin heavy chain (MYH) head-rod fragment aa664-915. MYH(664-915) was monomeric, adopted a closed shape, and bound essential myosin light chains (HIS-MLC-1) with low affinity to IQ1. Deletion of IQ2, however opened MYH(664-915). Four amino acids present in IQ2 could be identified to be responsible for this auto-inhibitory structural effect: alanine mutagenesis of I814, Q815, R819, and W827 stretched MYH(664-915) and increased 30fold the binding affinity of HIS-MLC-1 to IQ1. In this study we show, that denuded IQ2 favours a closed conformation of myosin with a low HIS-MLC-1 binding affinity. The collapsed structure of myosin with denuded IQ2 could explain the auto-inhibitory effects of IQ2 on enzymatic activity of myosin

    Auditive direct in utero observation (Audio): A randomized controlled trial for a prenatal demonstration of fetal hearing

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    Introduction: The objective of this randomized controlled study was to demonstrate whether acoustic stimulation in utero is associated with fetal reactivity which is documentable by car-diotocography. Materials and methods: A monocentric randomized controlled trial was performed at a single university tertiary hospital between September 2016 and July 2017. This study was registered as a randomized clinical trial on clinicaltrail.gov (registration number NCT04622059). Unselected pregnancies at term of gestation were consecutively recruited for the purpose of this study. After 10 min of normal cardiotocography without accelerations (non-stress-test with a basal frequency between 110 and 150 beats/min, normal variability between 6 and 15 b/min, no accelerations, and no fetal movements), fetuses were randomized at a 1:1 ratio to either of the two groups. Fetuses in group A (n = 105) received acoustic stimulation after 10 min from the beginning of the CTG, whereas fetuses in group B received no stimulation (n = 105). The outcome variables investigated were the lapse of time between the beginning of the CTG and the occurrence of the first accelera-tion, and the lapse of time between the beginning of the CTG and the first fetal movement noticed. Results: The lapse of time between the beginning of the CTG and the occurrence of the first acceleration was significantly shorter in the group with acoustic stimulation compared to the other group (14.87 ± 5.01 vs. 21.90 ± 6.94 min, p-value &lt; 0.001 log-rank test). Similarly, the lapse of time between the beginning of the CTG and the occurrence of the first fetal movement was significantly shorter in group A compared to group B (17.77 ± 7.62 vs. 23.28 ± 7.61 min, p-value &lt; 0.001, log-rank test). Fetal cardiac acceleration and the occurrence of a fetal movement during the first 20 min of the CTG were more frequently recorded in group A compared to group B (respectively, 15% vs. 5% and 20% vs. 8%). Conclusion: This RCT showed an early fetal reaction following auditive stimulus, documentable by cardiotocography. Further research is needed to investigate a possible role of acoustic stimulation in utero for the prenatal diagnosis of congenital hypoacusis

    Humanities in the undergraduate medical and midwifery curriculum: a descriptive Italian comparative study.

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    There is an increasing emphasis on humanized care in obstetric and midwifery practice. The goal of this paper is to investigate if and how medical humanities content was present in the undergraduate medical syllabus and how similar or different this is from the undergraduate midwifery program in Italy. A review of the 2017-18 curriculum for Italian Schools of Medicine and of Midwifery was carried out through institutional websites or mailing requests. The following details were collected for each program: the type of humanities content; the academic credits allocated, whether it was taught as a stand-alone (independent) topic or not, and the year(s) of the program when it was provided. Programs were included for 39 Schools of Medicine and 36 Schools of Midwifery. All midwifery schools included at least one subject with humanities content. Five medical schools (12.9) did not appear to have any subjects in this area. Psychology and ethics/bioethics were the most frequently found topics in both disciplines, but, apart from history of medicine, midwifery was much more likely than medicine to include other humanities topics, and especially pedagogy, anthropology, sociology and communication studies, philosophy and cross-cultural studies were rarely or never included in either discipline. A greater breadth of humanities studies was included in midwifery schools. However, their relative importance appears to be low, given the low level of academic credits and lack of presence as independent subjects

    Ahnak1 modulates L-type Ca(2+) channel inactivation of rodent cardiomyocytes

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    Ahnak1, a giant 700 kDa protein, has been implicated in Ca(2+) signalling in various cells. Previous work suggested that the interaction between ahnak1 and Cavbeta(2) subunit plays a role in L-type Ca(2+) current (I (CaL)) regulation. Here, we performed structure-function studies with the most C-terminal domain of ahnak1 (188 amino acids) containing a PxxP consensus motif (designated as 188-PSTP) using ventricular cardiomyocytes isolated from rats, wild-type (WT) mice and ahnak1-deficient mice. In vitro binding studies revealed that 188-PSTP conferred high-affinity binding to Cavbeta(2) (K (d) approximately 60 nM). Replacement of proline residues by alanines (188-ASTA) decreased Cavbeta(2) affinity about 20-fold. Both 188-PSTP and 188-ASTA were functional in ahnak1-expressing rat and mouse cardiomyocytes during whole-cell patch clamp. Upon intracellular application, they increased the net Ca(2+) influx by enhancing I (CaL) density and/or increasing I (CaL) inactivation time course without altering voltage dependency. Specifically, 188-ASTA, which failed to affect I (CaL) density, markedly slowed I (CaL) inactivation resulting in a 50-70% increase in transported Ca(2+) during a 0 mV depolarising pulse. Both ahnak1 fragments also slowed current inactivation with Ba(2+) as charge carrier. By contrast, neither 188-PSTP nor 188-ASTA affected any I (CaL) characteristics in ahnak1-deficient mouse cardiomyocytes. Our results indicate that the presence of endogenous ahnak1 is required for tuning the voltage-dependent component of I (CaL) inactivation by ahnak1 fragments. We suggest that ahnak1 modulates the accessibility of molecular determinants in Cavbeta(2) and/or scaffolds selectively different beta-subunit isoforms in the heart

    Сложность алгоритмов криптографической системы Эль–Гамаля и ихэффективность

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    Objective. - Electrical remodeling as well as atrial contractile dysfunction after the conversion of atrial fibrillation (AF) to sinus rhythm (SR) are mainly caused by a reduction of the inward L-type Ca2+ current (ICaL). We investigated whether the expression of L-type Ca2+-channel subunits was reduced in atrial myocardium of AF patients. Methods. - Right atrial appendages were obtained from patients undergoing coronary artery bypass graft surgery (CAD, n = 35) or mitral valve surgery (MVD, n = 37). Seventeen of the CAD patients and 18 of the MVD patients were in chronic (>3 months) AF, whereas the others were in SR. The protein expression of the L-type Ca2+-channel subunits {alpha}1C and {beta}2 was quantified by western blot analysis. Furthermore, we measured the density of dihydropyridine (DHP)-binding sites of the L-type Ca2+ channel using 3H-PN220-100 as radioligand. Results. - Surprisingly, the {alpha}1C and the {beta}2-subunit expression was not altered in atrial myocardium of AF patients. Also, the DHP-binding site density was unchanged. Conclusion. - The protein expression of the L-type Ca2+-channel subunits {alpha}1C or {beta}2 is not reduced in atrial myocardium of AF patients. Therefore, the reduced ICaL might be due to downregulation of other accessory subunits ({alpha}2{delta}), expression of aberrant subunits, changes in channel trafficking or alterations in channel function

    Diagnosing silent cardiac dysautonomia via ambulatory blood pressure monitoring: early diagnosis shown by the lack of heart rate circadian rhythm in type 1 diabetes mellitus

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    Introduction. Diabetes mellitus (DM) can be complicated by an involvement of Neurovegetative System (NVS), conventionally and non-invasively diagnosed by the means of Ewing's test and Heart Rate Variability (HRV) analysis. It is well known that the NVS is physiologically responsible, via biological clocks, for the regulation of Circadian Rhythms (CR) characterizing the majority of biological functions. Therefore, this study is aimed at investigating the CR of Heart Rate (HR) and Blood Pressure (BP) in DM, postulating that the diagnosis of Silent Cardiac Dysautonomia (SCD) could be facilitated by detecting anomalous rhythmometric changes, including the worse one, i.e., the lose of a CR. Materials and Methods. The study has been performed on 30 clinically healthy subjects (CHS), 10 patients with DM1 and 30 patients with DM2, who underwent an ambulatory BP monitoring (ABPM) collecting data equidistantly every 30 minutes, under standardized conditions of lifestyle. The group specific monitored values of systolic (S), diastolic (D) BP, as well as HR have been analyzed via: 1. a conventional analysis of their intradiem variability; 2. a chronobiometric analysis (Cosinor method) of their CR. Results. The conventional analysis disclosed that in CHS, DM1 and DM2, both the HR and BP show an intradiem variability that is significant (p&lt;0.001). The chronobiological analysis showed that in CHS and DM2, both the HR and BP show a significant CR (p&lt;0.001), viceversa in DM1 HR is characterized by a non significant CR (p=0.124), notwithstanding that the SBP and DBP maintain a significant CR (p&lt;0.001). Conclusions. The disappearance of HR CR in DM1 reveals the involvement of neurovegetative biological clock that selectively controls the HR CR, as it is demonstrated by the pathophysiological finding of an internal desynchronization between the HR and BP CR. The selective lose of HR CR in DM1 leads to conclude that the ABPM, along with its Cosinor analysis, might be a practical, repeatable, low cost, low risk technique for diagnosing the SCD, at least in DM1. Clin Ter 2010; 161(1):e1-e1

    Liver-related events and mortality among elderly patients with advanced chronic hepatitis C treated with direct-acting antivirals

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    Research article[Abstract] BACKGROUND: Direct-acting antivirals (DAAs) are effective in patients aged ≥65 years. However, little is known about the effects of DAAs on survival, liver decompensation and development of hepatocellular carcinoma (HCC). OBJECTIVE: To compare the incidence of liver-related events and mortality between patients aged ≥65 and <65 years. METHODS: Prospective study comparing patients aged ≥65 and <65 years treated with DAAs. The incidence of liver-related events and mortality, and HCC was compared between age groups. RESULTS: Five hundred patients (120 aged ≥65 and 380 aged <65 years) were included. The incidence of liver-related events was 2.62 per 100 patient-years (py) in older and 1.41/100 py in younger patients. All-cause mortality was 3.89 and 1.27/100 py in older and younger patients, respectively. The respective liver-related mortality rates were 1.12 and 0.31/100 py. In patients with cirrhosis (stage F4), all-cause mortality (P = 0.283) and liver-related mortality (P = 0.254) did not differ between groups. All five liver-related deaths were related to multifocal HCC. The incidence of HCC was 1.91 and 1.43 per 100 py in the older and younger groups, respectively (P = 0.747). The diagnosis of HCC was 8 months after the end of treatment. CONCLUSIONS: The incidence of liver-related events and liver-related mortality was low in older people treated with DAAs and was similar to that in younger patients. The extra mortality in people aged ≥65 years treated with DAAs seems to be secondary to non-liver-related causes. These results support the utilization of DAAs in patients aged ≥65 years.Instituto de Salud Carlos III; JR17/0002
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