Evidence that bacteria prefer to adhere to thrombus

This study was undertaken to investigate the possible association between thrombosis and infection using an in vitro test model in which fresh bovine blood was recirculated through test conduits (3.5 mm inner diameter) containing stent-like devices. Anticoagulation was adjusted so that the recirculating blood deposited thrombi on the stent to cause gradual occlusion, thus impeding the flow. Four stent-like devices were placed in separate conduits in each experiment, and blood was recirculated with the help of pneumatically driven ventricles. Flow through these conduits was monitored by ultrasonic flow detection. To quantitate bacterial interaction with thrombi, Staphylococcus epidermidis (15E10(9)) was labeled with 111Indium-oxine and added to the blood. Experiments lasted until the flow in the test conduits dropped to 10% of the starting flow. During this recirculation, as flow gradually decreased, one stent was taken out when flow was still at 100%, the second at 75%, the third at 50%, and the fourth at 10% of the starting flow. The number of bacteria associated with the thrombus was measured by gamma counting. The following observations were made: 1) the amount of thrombus increased with time in all experiments (this was confirmed in separate experiments by using autologous 111Indium labeled platelets); 2) bacterial adhesion showed a concomitant increase as thrombus size increased (this was confirmed by using 111Indium labeled bacteria), and 3) bacterial incorporation into the thrombus occurred regardless of whether they were viable or pretreated with the antibiotic rifampin. These observations suggest that as thrombi develop, they may preferentially attract micro-organisms. This suggests that devices with adherent thrombi may have greater susceptibility for infection.     

On the importance of van der Waals interaction in the groove binding of DNA with ligands: restrained molecular dynamics study

Comparison of interaction energy between an oligonucleotide and a DNA-binding ligand in the minor and major groove modes was made by use of restrained molecular dynamics. Distortion in DNA was found for the major groove mode whereas less significant changes for both ligand and DNA were detected for the minor groove binding after molecular dynamics simulation. The conformation of the ligand obtained from the major groove modes resembles that computed with the ligand soaked in water. The van der Waals contact energy was found to be as significant as electrostatic energy and more important for difference in binding energy between these two binding modes. The importance of van der Waals force in groove binding was supported by computations on the complex formed by the repressor peptide fragment from the bacteriophage 434 and its operator oligonucleotide.     

Does naming contribute to memory self-report in temporal lobe epilepsy?

The present study evaluated the hypothesis (Mayeux et al., 1980) that visual confrontation naming deficits may underlie the memory complaint in patients with temporal lobe epilepsy (TLE). Thirty-nine patients with medically refractory left (n = 23) and right (n = 16) TLE were compared with an epilepsy control group with idiopathic primary generalized epilepsy (n = 38). All subjects completed selected subtests of the Multilingual Aphasia Examination and Wechsler Memory Scale (Form 1) together with a measure specifically designed for quantification of the memory complaint in TLE. Objective verbal memory test performance, confrontation naming, repetition, and comprehension were unrelated to memory self-report. Controlled Oral Word Association was the only measure to exert an influence on memory self-ratings, and this relationship was specific to the TLE group. The hypothesis of Mayeux et al. (1980) was not specifically supported, but the present findings do suggest that cognitive processes reflected in orthographically based and internally generated word retrieval play a role in memory self-report.     

Understanding advanced hemodynamic concepts

This article reviews the determinants of myocardial oxygen supply (MVO2) and consumption and revisits the effects of IABC on each. Measurements of MVO2, including diastolic pressure-time index (DPTI), tension-time index (TTI), and endocardial viability ratios (EVR), demonstrate the dramatic effects of balloon deflation and the resulting afterload reduction on MVO2. IABC enhances ventricular outflow, thus decreasing preload; reduces systolic and end-diastolic aortic pressures, causing a decrease in ventricular afterload; magnifies the intrinsic Windkessel effect in the aorta, leading to an increased stroke volume; decreases static work and accordingly, MVO2; and stimulates the baroreceptors, causing a reduction in peripheral vascular resistance. IABC also increase in heart rate. Bedside computers enable the clinician to take a closer look at balloon efficacy via DPTI, TTI, and EVR. New sources of information and understanding may provide opportunities for nurses to ensure optimum patient outcomes.     

Effects of the PIPC model on outcome measures of productivity and costs

The purpose of this experimental research was to determine the effects of the Partners in Care Practice Model (PIPC) on the outcomes of productivity and costs. Over an 18-month study period, no significant differences were found in costs per patient day between the pilot and control units; however, significant differences were found in actual salaries, amount of time spent in documentation, and supply costs. Differences in costs and productivity reflected increased training costs and costs for additional supplies on the pilot unit.     

Comparison of effects induced by toxic applications of kainate and glutamate by glucose deprivation on area CA1 of rat hippocampal slices

This study focuses on the fortuitous discovery of an atypical atherosclerotic lesion in four of 49 male adult cynomolgus monkeys (macacus fascicularis) which were maintained for a long time at a high level of hypercholesterolemia, and in seven of 19 female cynomolgus monkeys examined from the second to the 24th week of hypercholesterolemic diet: this lesion was in formation or already mature during this period of diet. This atypical lesion was formed by a collagen and elastic network surrounding synthetic smooth muscle cells without fibrofatty or fibrous plaques. Lipids were occasionally seen in the inner intima. The lesion appeared early (from the third week of diet). Once established, its morphology did not change. It became more extensive, but was not complicated by lipid overload in spite of prolonged, permanent hypercholesterolemia. This response to hypercholesterolemia is interesting because the activity of the smooth muscle cells differs from that observed in the classic lesion: they intervene earlier, their replication is very marked and rapid, their elastin secretion is greater and remains constant over time, and their phagocytic properties are reduced. This experimental study examines the installation and the maintenance of this lesion and raises the problem of its origin.