A series of digitalis-like compounds with a 17-aminoalkoxyiminoalkyl or -alkenyl substituent was synthesized and evaluated for inhibition of Na(+),K(+)-ATPase and for inotropic activity. The highest inhibition was found with compounds having the substituent in configuration 17beta and the amino group at a distance of 6 or 7 bonds from C(17) of the digitoxigenin skeleton. The presence of the oxime function strengthens the interaction with the receptor, more if alpha,beta-unsaturated, thus mimicking the electronic situation of the unsaturated lactone in natural digitalis compounds. The most active compounds showed Na(+),K(+)-ATPase inhibitory potencies (IC(50)) 17-25 times higher than the standards digitoxigenin and digoxin and 3-11 times higher inotropic potencies (EC(50)) in isolated guinea pig left atria. These features are supported by a molecular model suggesting the possible interactions of the groups described above with particular amino acid residues in the H1-H2 domains of Na(+),K(+)-ATPase. Some interactions are the classical ones already described in the literature; a new, very strong interaction of the basic group with the Cys138 was found and adds new possibilities to design compounds interacting with this region of the receptor. The most interesting compounds were also studied in vivo in the anesthetized guinea pig for evaluating their inotropic effect versus the lethal dose. Compounds 9 and 12 showed a slightly higher safety ratio than digoxin and deserve further evaluation.

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BackgroundPeriodontitis is a multi-factorial disease and several risk-factors such as infections, inflammatory responses, oral hygiene, smoke, aging and individual predisposition are involved in the disease. Pathogens trigger chronic inflammation with cytokines release which in turn leads to the destruction of the connective and the teeth supporting bone. The identification of genetic factors controlling oral inflammation may increase our understanding of genetic predisposition to periodontitis.Single nucleotide polymorphisms in the promoter region of Vascular Endothelial Growth Factor, Alpha-1-Antichymotripsin, hydroxy-methyl-glutaryl CoA reductase, Interferon alpha, Interleukin-1 Beta, Interleukin 10, Interleukin 6 and Tumor Necrosis Factor- alpha genes from a case/control study were investigated.ResultsThe C allele of Vascular Endothelial Growth Factor, A allele of Interleukin 10 and GG genotype of Tumor Necrosis Factor-α were individually associated with chronic periodontitis. However, the concomitant presence of the three genetic markers in the same subjects appeared to play a synergistic role and increased several folds the risk of the disease.ConclusionsOur findings offer new tools to implement the screening of unaffected subjects with an increased susceptibility of periodontitis and increase our understanding regarding the genetic inflammatory background related to familiarity of the disease.

The novel Na ϩ /K ϩ -ATPase inhibitor (E,Z)-3-((2-aminoethoxy)-imino)androstane-6,17-dione hydrochloride (PST2744) was characterized for its inotropic and toxic properties. Inhibition potency on dog kidney Na ϩ /K ϩ -ATPase was comparable (0.43 M) to that of digoxin (0.45 M). PST2744 concentration-dependently increased force of contraction in guinea pig atria and twitch amplitude in isolated guinea pig myocytes; in the latter, aftercontractions developed significantly less than with digoxin. Intravenous infusion of 0.2 mg/kg/min PST2744 in anesthetized guinea pigs exerted an immediate and long-lasting inotropic effect (ED 80 of 1.89 Ϯ 0.37 mg/kg) without causing lethal arrhythmias up to a cumulative dose of 18 mg/kg. Conversely, an equieffective infusion of digoxin (0.016 mg/kg/min; ED 80 of 0.32 mg/kg) caused lethal arrhythmias at a cumulative dose of 0.81 mg/kg. At a higher rate (0.4 mg/kg/min), PST2744 induced lethal arrhythmias, with a lethal dose/ED 80 ratio significantly greater than digoxin (20.2 Ϯ 6.3 versus 3.23 Ϯ 0.55, p Ͻ 0.05). Decay of the inotropic effect (t 1/2 , min) was significantly faster for PST2744 (6.0 Ϯ 0.39) than for digoxin (18.3 Ϯ 4.5, p Ͻ 0.05). In anesthetized dogs, PST2744 dose-dependently increased maximum velocity of pressure rise (ϩdP/dt max ) in the range 32 to 500 g/kg i.v. and was safer than digoxin. In conscious dogs with a healed myocardial infarction, PST2744 significantly increased resting values of ϩdP/dt max , left ventricular pressure, and SPB, and increased ϩdP/dt max throughout treadmill exercise while reverting the increase in left ventricular end diastolic pressure seen in control animals. Digoxin significantly decreased basal heart rate, while not affecting the hemodynamic response to exercise. Thus, PST2744 represents a new class of Na ϩ /K ϩ -ATPase inhibitors endowed with inotropic activity comparable with that of digitalis but having greater safety.Improvement of heart failure (HF) treatment remains a major medical challenge for the coming years. Despite achievement of considerable progress during the last two decades, none of the available therapeutic agents is fully satisfactory, and HF remains a disease with a poor prognosis (Kannel, 2000). The goal of ameliorating quality of life, exercise capability, and survival is only partially met by angiotensin-converting enzyme inhibitors, diuretics, vasodilators, glycosides, and ␤-blocking agents, regardless of their being used in combined therapy (Consensus Recommendations for the Management of Chronic Heart Failure, 1999). Therefore, the need still remains for novel drugs able to increase workload tolerance and to reduce morbidity and mortality. Worsening of survival found with chronic administration of inotropic agents that increase intracellular cAMP (phosphodiesterase inhibitors and sympathomimetic amines) (The Xamoterol in Severe Heart Failure Study Group, 1990;Packer et al., 1991;Cohn et al., 1998) and the well known arrhythmogenic effects of cardiac glycosides have led to the general view that drug-i...