412 research outputs found

    Water-Soluble Ruthenium(III)-Dimethyl Sulfoxide Complexes: Chemical Behaviour and Pharmaceutical Properties

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    In this paper we report a review of the results obtained in the last few years by our group in the development of ruthenium(III) complexes characterized by the presence of sulfoxide ligands and endowed with antitumor properties. In particular, we will focus on ruthenates of general formula Na[trans-RuCl4(R1R2SO)(L)], where R1R2SO = dimethylsulfoxide (DMSO) or tetramethylenesulfoxide (TMSO) and L = nitrogen donor ligand. The chemical behavior of these complexes has been studied by means of spectroscopic techniques both in slightly acidic distilled water and in phosphate buffered solution at physiological pH. The influence of biological reductants on the chemical behavior is also described. The antitumor properties have been investigated on a number of experimental tumors. Out of the effects observed, notheworthy appears the capability of the tested ruthenates to control the metastatic dissemination of solid metastasizing tumors. The analysis of the antimetastatic action, made in particular on the MCa mammary carcinoma of CBA mouse, has demonstrated a therapeutic value for these complexes which are able to significantly prolong the survival time of the treated animals. The antimetastatic effect is not attributable to a specific cytotoxicity for metastatic tumor cells although in vitro experiments on pBR322 double stranded DNA has shown that the test ruthenates bind to the macromolecule, causing breaks corresponding to almost all bases, except than thymine, and are able to cause interstrand bonds, depending on the nature of the complex being tested, some of which results active as cisplatin itself

    Reduction of Lung Metastases by Na[trans-RuCl4(DMSO)Im] is not Coupled With the Induction of Chemical Xenogenization

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    The effects of the treatment of tumor cells of MCa mammary carcinoma and TLX5 lymphoma with the ruthenium complex Na[trans-RuCl4 (DMSO)lm] for several transplant generations were studied on tumor growth and metastases formation. On TLX5 lymphoma cells, treatment was performed in vitro prior to in vivo inoculation of tumor cells in intact or immunesuppressed mice. Either considering tumor take and growth or its capacity to invade the brain of the inoculated hosts, Na[trans-RuCl4(DMSO)lm] did not induce any significant modification. Conversely, in mice with MCa mammary carcinoma, the in vivo treatment of tumor cells in immunesuppressed hosts caused a progressive increase of DNA activity and, starting from the 4th transplant generation, a significantly increased susceptibility of lung metastasis formation to a further treatment in intact mice. These data seem to suggest that Na[trans-RuCl4(DMSO)Im] does not induce chemical xenogenization of tumor cells nor its repeated treatment induces resistance in tumor cells. Conversely, it appears that Na[trans-RuCl4(DMSO)lm] may select a tumor cell population which maintains its capacity to metastasise to the lung but with enhanced sensitivity to the antimetastatic properties of this compound

    Efficacy of 5-FU Combined to Na[trans-RuCl4(DMSO)Im], A Novel Selective Antimetastatic Agent, on the Survival Time of Mice With P388 Leukemia, P388/DDP subline and MCa Mammary Carcinoma

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    The combinational treatment between the selective antimetastatic agent, sodium-trans-rutheniumtetrachloridedimethylsulfoxideimidazole, Na[trans-RuCl4(DMSO)Im], and the cytotoxic drug 5-fluorouracil (5-FU) on primary tumor growth and on the survival time of experimental tumors results in an effect significantly greater than that of each single agent used alone either with the solid metastasizing MCa mammary carcinoma of the CBA mouse or with the lymphocytic leukemia P388 and its platinum resistant P388/DDP subline. Thus the inorganic compound Na[trans-RuCl4(DMSO)Im], known for its potent and selective antimetastatic effects, positively interacts with the antitumor action of an organic anticancer agent such as 5-FU on both a solid metastasizing tumor and a tumor of lymphoproliferative type. In particular, the effects of the combinational treatment on the survival time of tumor bearing mice seem to be related to the selective antimetastatic activity of the ruthenium complex that joins the potent cytotoxicity of 5-FU for the tumor. Moreover, these data show that Na[trans-RuCl4(DMSO)Im] is almost as effective on the subline of P388 made resistant to cisplatin as it was on the parental line

    AFM macro-probes to investigate whole 3D cardiac spheroids

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    In its many applications, the Atomic Force Microscope (AFM) is a promising tool in cardiac mechanobiology because it can unravel the viscoelastic and mechano-dynamic properties of individual cardiomyocytes. However, the biophysical investigation of more accurate 3D models is hampered by commercial probes, which typically operate at the cell sub-compartmental resolution. We have previously shown how flat macro-probes can overcome these limitations by extending the AFM mechanical measurements to multicellular aggregates. Such macro-probes are fabricated by standard micromachining and carry a flat polymeric wedge to offset the AFM mounting tilt. Therefore, the AFM is upgraded to a micro-parallel plate rheometer with unmatched force range and sensitivity. In this article, we show how these macro-probes can be applied to reveal the global rheology of primary cardiomyocytes spheroids, by performing stress-relaxation tests. More importantly, we demonstrate that these macro-probes can be used as passive sensors capable of monitoring the spheroid beating force and beating pattern, and to perform a “micro-CPR” on the spheroid itself

    Molecular and Cellular Mechanisms in Heart Failure

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    Pathophysiology and treatment of pediatric heart failure (HF) is poorly understood. A growing body of literature demonstrates age-related differences in mechanisms and in therapies efficacy. HF results from ventricular dysfunction due to volume or/and pressure overload. Circulatory, neurohormonal, and molecular alterations promote the progression of HF and ventricular remodeling; they include inflammation, oxidative stress, mitochondrial dysfunction, loss of cardiomyocytes, and fibrosis. Children and young affected by cardiomyopathies have the greatest risk of HF and heart transplantation. Genetic mutations of sarcomere, cytoskeleton, cell membrane proteins, and ion channels have been recognized as the main causes of many cardiomyopathy phenotypes. In particular, sarcomeric and cytoskeleton genes mutations seem to have an important role in the progression of HF. Prognostic stratification and clinical management could benefit from identification of biomarkers such as inflammatory mediators or microRNA (miRNA). miRNA and myocardial regenerative strategies are under investigations as potential novel therapeutic approaches

    The electrocardiogram in the diagnosis and management of patients with dilated cardiomyopathy.

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    The term dilated cardiomyopathy (DCM) defines a heterogeneous group of cardiac disorders, which are characterized by left ventricular or biventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to cause global systolic impairment. In approximately one third of cases, DCM is familial with a genetic pathogenesis and various patterns of inheritance. Although the electrocardiogram (ECG) has been considered traditionally non-specific in DCM, the recently acquired knowledge of the genotype-phenotype correlations provides novel opportunities to identify patterns and abnormalities that may point toward specific DCM subtypes. A learned ECG interpretation in combination with an appropriate use of other ECG-based techniques including ambulatory ECG monitoring, exercise tolerance test and imaging modalities, such as echocardiography and cardiovascular magnetic resonance, may allow the early identification of specific genetic or acquired forms of DCM. Furthermore, ECG abnormalities may reflect the severity of the disease and provide a useful tool in risk stratification and management. In the present review, we discuss the current role of the ECG in the diagnosis and management of DCM. We describe various clinical settings where the appropriate use and interpretation of the ECG can provide invaluable clues, contributing to the important role of this basic tool as cardiovascular medicine evolves

    Cellular Biomechanic Impairment in Cardiomyocytes Carrying the Progeria Mutation: An Atomic Force Microscopy Investigation

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    Given the clinical effect of progeria syndrome, understanding the cell mechanical behavior of this pathology could benefit the patient's treatment. Progeria patients show a point mutation in the lamin A/C gene (LMNA), which could change the cell's biomechanical properties. This paper reports a mechano-dynamic analysis of a progeria mutation (c.1824 C > T, p.Gly608Gly) in neonatal rat ventricular myocytes (NRVMs) using cell indentation by atomic force microscopy to measure alterations in beating force, frequency, and contractile amplitude of selected cells within cell clusters. Furthermore, we examined the beating rate variability using a time-domain method that produces a Poincaré plot because beat-to-beat changes can shed light on the causes of arrhythmias. Our data have been further related to our cell phenotype findings, using immunofluorescence and calcium transient analysis, showing that mutant NRVMs display changes in both beating force and frequency. These changes were associated with a decreased gap junction localization (Connexin 43) in the mutant NRVMs even in the presence of a stable cytoskeletal structure (microtubules and actin filaments) when compared with controls (wild type and non-treated cells). These data emphasize the kindred between nucleoskeleton (LMNA), cytoskeleton, and the sarcolemmal structures in NRVM with the progeria Gly608Gly mutation, prompting future mechanistic and therapeutic investigations

    Biomechanical defects and rescue of cardiomyocytes expressing pathologic nuclear lamins

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    Given the clinical impact of LMNA cardiomyopathies, understanding lamin function will fulfill a clinical need and will lead to advancement in the treatment of heart failure. A multidisciplinary approach combining cell biology, atomic force microscopy (AFM) and molecular modeling was used to analyze the biomechanical properties of human lamin A/C gene (LMNA) mutations (E161K, D192G, N195K) using an in vitro neonatal rat ventricular myocyte (NRVM) model

    Arrhythmogenic Phenotype in Dilated Cardiomyopathy: Natural History and Predictors of Life-Threatening Arrhythmias

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    BACKGROUND-\u2014Patients with dilated cardiomyopathy (DCM) may present with ventricular arrhythmias early in the disease course, unrelated to the severity of left ventricular dysfunction. These patients may be classified as having an arrhythmogenic DCM (ARDCM). We investigated the phenotype and natural history of patients with AR-DCM. METHODS AND RESULTS-\u2014Two hundred eighty-five patients with a recent diagnosis of DCM (median duration of the disease 1 month, range 0 to 7 months) and who had Holter monitoring at baseline were comprehensively evaluated and followed for 107 months (range 29 to 170 months). AR-DCM was defined by the presence of 651 of the following: unexplained syncope, rapid nonsustained ventricular tachycardia ( 655 beats, 65150 bpm), 651000 premature ventricular contractions/24 hours, and 6550 ventricular couplets/ 24 hours, in the absence of overt heart failure. The primary end points were sudden cardiac death (SCD), sustained ventricular tachycardia (SVT), or ventricular fibrillation (VF). The secondary end points were death from congestive heart failure or heart transplantation. Of the 285 patients, 109 (38.2%) met criteria for AR-DCM phenotype. AR-DCM subjects had a higher incidence of SCD/SVT/VF compared with non\u2013AR-DCM patients (30.3% vs 17.6%, P=0.022), with no difference in the secondary end points. A family history of SCD/SVT/VF and the AR-DCM phenotype were statistically significant and cumulative predictors of SCD/SVT/VF. CONCLUSIONS-\u2014One-third of DCM patients may have an arrhythmogenic phenotype associated with increased risk of arrhythmias during follow-up. A family history of ventricular arrhythmias in DCM predicts a poor prognosis and increased risk of SCD

    Decreased levels of BAG3 in a family with a rare variant and in idiopathic dilated cardiomyopathy.

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    The most common cause of dilated cardiomyopathy and heart failure (HF) is ischemic heart disease; however, in a third of all patients the cause remains undefined and patients are diagnosed as having idiopathic dilated cardiomyopathy (IDC). Recent studies suggest that many patients with IDC have a family history of HF and rare genetic variants in over 35 genes have been shown to be causative of disease. We employed whole-exome sequencing to identify the causative variant in a large family with autosomal dominant transmission of dilated cardiomyopathy. Sequencing and subsequent informatics revealed a novel 10-nucleotide deletion in the BCL2-associated athanogene 3 (BAG3) gene (Ch10:del 121436332_12143641: del. 1266_1275 [NM 004281]) that segregated with all affected individuals. The deletion predicted a shift in the reading frame with the resultant deletion of 135 amino acids from the C-terminal end of the protein. Consistent with genetic variants in genes encoding other sarcomeric proteins there was a considerable amount of genetic heterogeneity in the affected family members. Interestingly, we also found that the levels of BAG3 protein were significantly reduced in the hearts from unrelated patients with end-stage HF undergoing cardiac transplantation when compared with non-failing controls. Diminished levels of BAG3 protein may be associated with both familial and non-familial forms of dilated cardiomyopathy
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