The aim of the present study was to examine the left ventricular and haemodynamic parameters during acute hypoxia induced by carbon monoxide intoxication and/or after norepinephrine administration in metabolically healthy and alloxan-diabetic dogs. In metabolically healthy animals after carbon monoxide intoxication followed by norepinephrine administration myocardial oedema occurred with a concomitant elevation of diastolic stiffness in the left ventricular wall, resulting in impaired cardiac performance. In the alloxan-diabetic animals no myocardial oedema developed and therefore no further increase of the originally elevated left ventricular diastolic stiffness could be observed. Close correlations were demonstrable between the enhanced water content and diastolic stiffness of the left ventricular wall in metabolically healthy animals as well as between the myocardial contractile force and cardiac output index in both control and diabetic dogs. In contrast to the controls, following norepinephrine administration per se decrease of cardiac performance could be observed in the alloxan-diabetic animals. Based on these results, it can be concluded that an increase of left ventricular diastolic stiffness impairs the cardiac performance in acute hypoxia following norepinephrine administration both in control and in diabetic animals, even if different reasons are responsible for it.

Animals↗

PubMedDate not supplied

Effects of coronary occlusion and norepinephrine on the myocardium of alloxan-diabetic dogs.

The aim of this study was to clarify the role of altered diabetic vascular reactivity in ischaemic heart disease. In diabetic condition, the necrotic area of myocardial infarction was significantly extended and myocardial oedema failed to develop after administration of norepinephrine 2 or 48 hours after ligation of the left anterior descending coronary artery. In metabolically healthy dogs the necrotic area of myocardial infarction was considerably smaller and an increase in myocardial water content, in myocardial thiocyanate space, in microscopically demonstrable permeability and in diastolic stiffness of left ventricular wall occurred when norepinephrine was administered 2 or 48 hours after coronary infarction. A close correlation was demonstrable between enhanced water content, thiocyanate space and diastolic stiffness in metabolically healthy animals, whereas in diabetic condition diastolic stiffness was primarily increased, and decreased when norepinephrine was infused after coronary ligation. Therefore, the altered vascular reactivity in diabetes is supposed to be responsible for the lack of oedema in the nonischaemic part of myocardium after norepinephrine infusion as well as for the size and severity of myocardial infarction.

Animals↗

PubMedDate not supplied

Reduction of cisplatin toxicity in cultured renal tubular cells by the bioflavonoid quercetin.

Quercetin (QC), a polyphenolic compound widely distributed in fruits and vegetables has recently gained interest due to its cisplatin (CP) sensitizing properties in cancer cells. It is currently unknown, whether quercetin also increases the susceptibility of the kidneys to cisplatin toxicity. We studied the effects of various bioflavonoids on CP toxicity in an in vitro model of cultured tubular epithelial cells (LLC-PK1). Viability of LLC-PK1 cells, as assessed by lactate dehydrogenase (LDH) release and MTT-test, was affected by CP (100-400 microM) in a time and dose dependent fashion. Pretreatment of cells with QC for 3 h significantly reduced the extent of cell damage. The protective activity of QC was concentration dependent, starting at 10-25 microM and reaching a plateau between 50 and 100 microM. Other bioflavonoids (catechin, silibinin, rutin) did not diminish cellular injury, even at higher concentrations (100-500 microM). Quercetin itself showed some intrinsic cytotoxicity at concentrations exceeding 75 microM. Our data indicate that quercetin reduces cisplatin toxicity in cultured tubular epithelial cells. The exact mechanism of protection is unclear, though scavenging of free oxygen radicals may play an important role.

Animals↗

PubMedDate not supplied

An approach to single trial analysis of event-related potentials based on signal detection theory.

The aim of the present paper was to introduce a single trial analysis to event-related potential measurement in order to illuminate the mechanisms behind an impaired P300 amplitude occurring under certain experimental conditions. For this purpose we applied tools from linear system theory and signal detection theory to single trials in an oddball paradigm in order to estimate the amplitude of the positive deflection around the P300 latency following target and nontarget stimuli. According to the density functions of these amplitude distributions we operationally defined 'P300 absent in target' (P300 amplitude smaller than an individual threshold under target conditions) as well as 'P300 present in nontarget' (amplitude greater than the threshold under nontarget conditions). Our approach appears to be appropriate to differentiate between an overall reduction of single trial event-related potentials and seldom elicited P300s.

Adult↗

PubMedDate not supplied

Objectives to direct the training of emergency medicine residents on off-service rotations: pulmonary.

This article outlines the objectives for a resident rotation in pulmonary diseases. It is part of a continuing series on the goals and objectives to direct Emergency Medicine resident training on off-service rotations. Pulmonary disease accounts for a high percentage of presenting complaints and potentially life-threatening disease in the emergency department. Because of the frequency of respiratory disease in Emergency Medicine, many Emergency Medicine residencies offer individual off-service rotations in Pulmonary Medicine. The objectives of this article are viewed as a one-month component of an Internal Medicine Rotation in the first year of training. These objectives are designed to help focus the resident's reading and study during a pulmonary off-service rotation.

Emergency Medicine↗

PubMedDate not supplied

Neurotoxicity of organic solvent mixtures: embryotoxicity and fetotoxicity.

The toxicity of organic solvents at different concentrations was examined to determine their effect on pregnant rats and their offspring. A very serious effect which inhalational exposure to n-hexane, methyl-ethyl-ketone and a mixture of the two organic solvents produced in pregnant rats was a concentration-dependent increase of intrauterine mortality. In cases of only prenatal exposure, the persistence of reduced body growth was an important result obtained at all concentrations we investigated (first solvent experiment, 500 ppm; second solvent experiment, 800 ppm; and third solvent experiment, 1000 to 1500 ppm; 23 hr day). In these cases, a delay in the maturation of cerebellar cortex was also observed. In cases of pre- and postnatal solvent exposure, the effects of malnutrition were added to the solvent-induced retardation. This resulted in an extreme delay in tissue maturation accompanied by a retarded cell maturation. The solvents examined had no teratogenic effect in pregnant rodents and their offspring. Neurotoxicity was restricted to the known structures of the adult animals, whose axons were damaged. They did, however, show a concentration-dependent embryotoxic and fetotoxic effect.

Administration, Inhalation↗