Electromechanical effects of two low osmolality contrast media, ioxaglate and iohexol, on isolated rat atria

This study aimed at investigating the direct effects of two low osmolality radiographic contrast media, iohexol (non-ionic) and ioxaglate (ionic), on transmembrane action potentials, contractile force and refractoriness of isolated rat atrial preparations. Superfused with 10% solution, ioxaglate induced a biphasic mechanical response, initially decreasing and thereafter increasing contractile force. The same concentration of iohexol only increased contractile force. The two contrast media increased the resting membrane potential, action potential amplitude and rate of depolarization to the same extent. Iohexol prolonged repolarization. Both contrast media decreased the effective refractory period. The direct effects of contrast media on myocardial contractility in this study can explain the different haemodynamic effects of iohexol and ioxaglate in vivo. The observed effects on the action potentials in vitro can explain commonly observed ECG changes during coronary arteriography. The changes in depolarization, repolarization and refractoriness are probably related to the arrhythmogenic properties of these contrast media.     

Down-regulation of Na channel expression by A23187 in NlE-115 neuroblastoma cells

Growth of cultured NlE-115 neuroblastoma cells in 1 μM A23187 for 2 days to elevate internal Ca reduced both membrane Na current and the transient, but not steady state, component of outward K current. Na channel mRNA abundance was reduced by an average value of 45% without effect on Kv3.1. Increases in internal Ca may therefore control excitability by independent regulation of Na and K channel mRNA abundance in neurons.     

The MS-MS Determination of the Fragmentation Pathways of Some Substituted 1,2,3-Benzotriazin-4-ones with Possible Applications in Metabolic Studies

1,2,3-Benzotriazin-4-one derivatives are extensively used as herbicides, insecticides and nematicides. Incorporation of these compounds into the human food chain is a cause for concern, since their toxicity to man is well documented. This work describes the development of a data-base of classical 1,2,3-benzotriazin-4-one fragmentation patterns and consequent sequential neutral mass losses which allows the prediction of the presence of a triazinone derived compound. Positive and negative ion tandem mass spectrometry techniques were employed since they allow rapid and sensitive structural characterization of drugs and their metabolites in biological fluids through the unambiguous monitoring of daughter ions from pre-selected primary ions.     

The influence of piracetam on the effects of narcotic analgesics

In experiments on white male mice there was studied the influence of piracetam (250-300 mg/kg) on the analgesic effect of ligands of different types of opioid receptors (morphine, 7.5 mg/kg, DADLE, 7.5 mg/kg, pentazocine, 15 mg/kg) and also on the action of morphine concerning the cardiovascular system and respiration. Piracetam was shown to possess the antagonistic properties with respect to some effects of morphine, however they are not of the universal character and do not depend on the interaction with a certain type of opioid receptors.     

Status of the blood coagulation system in traumatic disease

Under examination there were 198 patients with severe mechanical traumas at their admission to the clinic and on the 1st, 3d, 7th, 14th and 21st days by 25 hemocoagulation parameters determined by common present-day methods. The direction and degree of hemocoagulation alterations were found to be related with the severity of trauma, blood loss volume and severity of shock. It was shown that disseminated intravascular coagulation (DIC) of the II and III degree was developing in critical associated traumas, massive blood loss and severe shock in acute period of the disease. The acute form of DIC with reactive fibrinolysis was established in the lethal outcome during the shock period, latent (slow) DIC with local fibrinolysis took place in lethal outcomes in later periods.     

An analysis of two recent epidemiologic reports in the New England Journal of Medicine associating breast cancer in women with moderate alcohol consumption

Two cohort studies showed an association between moderate alcohol consumption and breast cancer, with an apparent relative risk of 1.50. Drinkers and nondrinkers already differed in important ways at the initiation of these two studies, precluding a causal interpretation of the associations found. Women in need of the relaxing effect of alcohol may indeed be the group at higher risk for breast cancer. Inasmuch as the studies did not inquire into other cancers, morbidities, mortalities, or total mortality, they leave open the possibility that, on balance, moderate alcohol consumption is beneficial.