The presence of arginine may be a source of false positive results in the Ames test.

An increase in the number of revertant colonies in the Ames test is generally taken as a strong indication of mutagenic activity of a test compound. However, irrelevant positive findings may constitute a major problem in regulatory drug testing. In this study, mixtures containing only amino acids such as glycine, lysine, arginine and isoleucine, routinely used as peptide preservatives in polypeptide pharmaceutical products, were investigated for mutagenesis in the Ames Salmonella typhimurium test.

Prophylaxis and therapy for Chikungunya virus infection.

Background: Chikungunya virus (CHIKV) is a recently reemerged arbovirus responsible for a massive outbreak of infection in the Indian Ocean region and India that has a very significant potential to spread globally because of the worldwide distribution of its mosquito vectors. CHIKV induces a usually self-limited disease in humans that is characterized by fever, arthralgia, myalgia, and rash; however, cases of severe CHIKV infection have recently been described, particularly in adults with underlying condition and neonates born to viremic mothers.

Methods: Human polyvalent immunoglobulins were purified from plasma samples obtained from donors in the convalescent phase of CHIKV infection, and the preventive and curative effects of these immunoglobulins were investigated in 2 mouse models of CHIKV infection that we developed.

Protection from myocardial stunning by ischaemia and hypoxia with the adenosine A3 receptor agonist, IB-MECA.

Guinea pig isolated working hearts were exposed to 30-min ischaemia by reducing coronary flow to 10%, followed by reperfusion. Aortic output fell to 4.5+/-4.

Role of endothelium in ischaemia-induced myocardial dysfunction of isolated working hearts: cardioprotection by activation of adenosine A(2A) receptors.

1 This study aimed to determine the role of the vascular endothelium on recovery of contractile function following global low-flow ischaemia of guinea-pig isolated working hearts and the effects of adenosine analogues on this recovery. 2 Guinea-pig isolated spontaneously beating or paced working hearts were set up and coronary flow (CF), aortic output (AO) (as an index of cardiac function), heart rate (HR), left ventricular pressure (LVP) and dP/dt max recorded. The endothelium was either intact or removed by a blast of oxygen.

Effects of adenosine receptor agonists on guinea-pig isolated working hearts and the role of endothelium and NO.

The hypothesis that the coronary vasodilator effects of adenosine receptor agonists are independent of the vascular endothelium or mediators derived therefrom was examined in guinea-pig isolated working hearts. Adenosine receptor agonists, 5'-(N-ethylcarboxamido)-adenosine (NECA; two-fold selective for A2 over A1 receptors), 2-[p-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680; A2A selective), N6-cyclopentyl-adenosine (CPA; A1 selective) and N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA; A3 selective), were infused (3 x 10(-7) M) after endothelium removal by passing oxygen through the coronary circulation. In spontaneously beating hearts, CGS21680 and NECA increased, while CPA decreased, coronary flow.