7 research outputs found

    Ferroxitosis: a cell death from modulation of oxidative phosphorylation and PKM2-dependent glycolysis in melanoma

    Get PDF
    Reliance on glycolysis is a characteristic of malignancy, yet the development of resistance to BRAF inhibitors in melanoma is associated with gain of mitochondrial function. Concurrent attenuation of oxidative phosphorylation and HIF-1α/PKM2-dependent glycolysis promotes a non-apoptotic, iron- and oxygen-dependent cell death that we term ferroxitosis. The redox cycling agent menadione causes a robust increase in oxygen consumption, accompanied by significant loss of intracellular ATP and rapid cell death. Conversely, either hypoxic adaptation or iron chelation prevents menadione-induced ferroxitosis. Ectopic expression of K213Q HIF-1α mutant blunts the effects of menadione. However, knockdown of HIF-1α or PKM2 restores menadione-induced cytotoxicity in hypoxia. Similarly, exposure of melanoma cells to shikonin, a menadione analog and a potential PKM2 inhibitor, is sufficient to induce ferroxitosis under hypoxic conditions. Collectively, our findings reveal that ferroxitosis curtails metabolic plasticity in melanoma

    A rare case of apical hypertrophic cardiomyopathy (AHCM)

    No full text
    Apical hypertrophic cardiomyopathy is a rare form of hypertrophic cardiomyopathy that involves thickening of the distal portion of the left ventricular wall. Most commonly seen in the Japan, with a prevalence rate of about 15% of all HCM patient, its incidence in the USA is approximately 3% of HCM cases. We report a case of a 46-year-old woman with history of hypertension who presented to emergency department with worsening dyspnea and orthopnea with features of left ventricular hypertrophy (LVH) and diffuse large T-wave inversions in the lateral leads on a 12-lead ECG. Further work up revealed severe concentric LVH, with near obliteration of the LV cavity. Ventriculogram showed severe symmetric hypertrophy of the mid to lower septum, extending to the apex of left ventricle with significant pressure gradient of at least 160 mmHg across the apex to mid septal cavity, with no significant gradient across the left ventricular outflow tract. These findings were consistent with apical hypertrophic cardiomyopathy. She was treated with verapamil and metoprolol and has remained asymptomatic over last 2.5 years of follow-up. Although the clinical presentation of AHCM can be variable and nonspecific; however, hallmark findings on ECG and echo can be extremely important in its diagnosis. Abbreviations: AHCM: Apical hypertrophic cardiomyopathy; ECG: Electrocardiogram; LVH: Left ventricular hypertrophy; LVOT: Left ventricular outflow trac

    A rare case of apical hypertrophic cardiomyopathy (AHCM).

    No full text
    Apical hypertrophic cardiomyopathy is a rare form of hypertrophic cardiomyopathy that involves thickening of the distal portion of the left ventricular wall. Most commonly seen in the Japan, with a prevalence rate of about 15% of all HCM patient, its incidence in the USA is approximately 3% of HCM cases. We report a case of a 46-year-old woman with history of hypertension who presented to emergency department with worsening dyspnea and orthopnea with features of left ventricular hypertrophy (LVH) and diffuse large T-wave inversions in the lateral leads on a 12-lead ECG. Further work up revealed severe concentric LVH, with near obliteration of the LV cavity. Ventriculogram showed severe symmetric hypertrophy of the mid to lower septum, extending to the apex of left ventricle with significant pressure gradient of at least 160 mmHg across the apex to mid septal cavity, with no significant gradient across the left ventricular outflow tract. These findings were consistent with apical hypertrophic cardiomyopathy. She was treated with verapamil and metoprolol and has remained asymptomatic over last 2.5 years of follow-up. Although the clinical presentation of AHCM can be variable and nonspecific; however, hallmark findings on ECG and echo can be extremely important in its diagnosis

    Synthesis, Structure, and Properties of New Mg(II)-Metal–Organic Framework and Its Prowess as Catalyst in the Production of 4<i>H</i>‑Pyrans

    No full text
    A new alkaline metal–organic framework, [Mg<sub>3</sub>(NDC)<sub>3</sub>(DMF)<sub>4</sub>]·H<sub>2</sub>O (<b>1</b>) is synthesized solvothermally by using 2,6-naphthalenedicarboxylic acid (NDC) as ligand and dimethylformamide (DMF) and water as mixed solvent. Single crystal X-ray studies show that <b>1</b> crystallizes in the space group <i>C2/c</i> with parameters <i>a</i> = 13.4191(2), <i>b</i> = 18.0669(2), <i>c</i> = 20.9746(3) Å, and β = 99.66(0)<sup>o</sup>. The central metal atom Mg­(II) adopts a six coordinated octahedral geometry with carboxylate oxygen atoms and DMF molecules. Due to the involvement of oxygen atoms in bridging and chelation binding, a trinuclear secondary building unit is built up, which further connects to other six NDC ligands and finally leading to a three-dimensional network. The thermal and luminescent analysis revealed that the compound is thermally stable with violet emission. The creation of coordinatively unsaturated Mg­(II) centers, acting as Lewis-acidic sites upon activation, are explored to use <b>1</b> as heterogeneous catalyst in value-added organic conversions. MOF showed a superb catalytic performance in the synthesis of eight 4<i>H</i>-pyran derivatives via one-pot three-component reaction between aromatic aldehydes, malononitrile, and cyanoacetamide at room temperature. All the reactions worked exceptionally well with excellent yields (91–96%), in short reaction times (<40 min). Green solvent (ethanol) and easy separation, reusability and robust structure of catalyst are the attractions of the protocol and make [Mg<sub>3</sub>(NDC)<sub>3</sub>(DMF)<sub>4</sub>]·H<sub>2</sub>O an ideal catalyst for wide-ranging organic transformations
    corecore