Acute dyspnea in Emergency Department: point of care ultrasound in the diagnosis of atrial sarcoma

We describe a rare case of a 65-year-old patient presented to Emergency Department for acute dyspnea. Traditional diagnostic work-up was done and the emergency physician promptly performed a bedside point-of-care ultrasound. A giant mass in the left atrium was detected with impairing of mitral valve function. The patient was then sent to cardiac surgery department with a final diagnosis of high-grade cardiac sarcoma

The active site of Sulfolobus solfataricus aspartate aminotransferase

Aspartate aminotransferase from the archaebacterium Sulfolobus solfataricus binds pyridoxal 5' phosphate, via an aldimine bond, with Lys-241. This residue has been identified by reducing the enzyme in the pyridoxal form with sodium cyanoboro[H-3]hydride and sequencing the specifically labeled peptic peptides. The aminoacidic sequence centered around the coenzyme binding site is highly conserved between thermophilic aspartate aminotransferases and differs from that found in mesophilic isoenzymes. An alignment of aspartate aminotransferase from Sulfolobus solfataricus with mesophilic isoenzymes, attempted in spite of the low degree of similarity, was confirmed by the correspondence between pyridoxal 5' phosphate binding residues. Using this alignment it was possible to insert the archaebacterial aspartate aminotransferase into a subclass, subclass I, of pyridoxal 5' phosphate binding enzymes comprising mesophilic aspartate aminotransferases, tyrosine aminotransferases and histidinol phosphate aminotransferases. These enzymes share 12 invariant amino acids most of which interact with the coenzyme or with the substrates. Some enzymes of subclass I and in particular aspartate aminotransferase from Sulfolobus solfataricus, lack a positively charged residue, corresponding to Arg-292, which in pig cytosolic aspartate aminotransferase interacts with the distal carboxylate of the substrates (and determines the specificity towards dicarboxylic acids). It was confirmed that aspartate aminotransferase from Sulfolobus solfataricus does not possess any, arginine residue exposed to chemical modifications responsible for the binding of omega-carboxylate of the substrates. Furthermore, it has been found that aspartate aminotransferase from Sulfolobus solfataricus is fairly active when alanine is used as substrate and that this activity is not affected by the presence of formate. The K(M) value of the thermophilic aspartate aminotransferase towards alanine is at least one order of magnitude lower than that of the mesophilic analogue enzymes

Supplementary Material from Ovothiol ensures the correct developmental programme of the sea urchin Paracentrotus lividus embryo

Supplementary Figures 1-7, Supplementary Table 1. -- 10 pages.Peer reviewe

Ovothiol ensures the correct developmental programme of the sea urchin Paracentrotus lividus embryo

Ovothiols are π-methyl-5-thiohistidines produced in great amounts in sea urchin eggs, where they can act as protective agents against the oxidative burst at fertilization and environmental stressors during development. Here we examined the biological relevance of ovothiol during the embryogenesis of the sea urchin Paracentrotus lividus by assessing the localization of the key biosynthetic enzyme OvoA, both at transcript and protein level, and perturbing its protein translation by morpholino antisense oligonucleotide-mediated knockdown experiments. In addition, we explored the possible involvement of ovothiol in the inflammatory response by assessing ovoA gene expression and protein localization following exposure to bacterial lipopolysaccharide. The results of the present study suggest that ovothiol may be a key regulator of cell proliferation in early developing embryos. Moreover, the localization of OvoA in key larval cells and tissues, in control and inflammatory conditions, suggests that ovothiol may ensure larval skeleton formation and mediate inflammatory processes triggered by bacterial infection. This work significantly contributes to the understanding of the biological function of ovothiols in marine organisms, and may provide new inspiration for the identification of the biological activities of ovothiols in humans, considering the pharmacological potential of these molecules.A.M. and M.C. were supported by a PhD fellowship funded by the Stazione Zoologica Anton Dohrn (Open University-Stazione Zoologica Anton Dohrn PhD Program).Peer reviewe

Implantable device-related endocarditis detected by point-of-care echocardiography in a patient with dyspnea and chest pain

We describe a case of a 70-year-old man who presented to the emergency department with dyspnea and chest pain. He had history of atrial fibrillation, chronic obstructive pulmonary disease, prosthetic mitral valve and pacemaker implantation. He had a sepsis related to multiple bilateral septic emboli pointed out by chest computed tomography scan. Point of care echocardiography showed a pacemaker-related endocarditis with large vegetation on the right ventricular lead. The patient started empiric antibiotic therapy and he was addressed to complete hardware removal

Electrocardiographic features of hyperkalemia during acute kidney injury in a patient with pacemaker

We describe a case of a 79-year-old man with pacemaker who presented to the Emergency Department due to asthenia and acute confusional state. He had a history of atrial fibrillation, anemia and colostomy and he was on treatment with diuretics. The electrocardiogram (ECG) showed pacemaker-induced ventricular activity, QRS complexes excessively wide with sine-wave appearance, tall and peaked T waves, without electrically evident atrial activity. Potassium concentration on arterial blood gas analysis was 8.8 mmol/L. ECG abnormalities disappeared after therapy with calcium chloride and spontaneous cardiac activity reappeared