Selectivity in the potentiation of antibacterial activity of α-peptide/β-peptoid peptidomimetics and antimicrobial peptides by human blood plasma

Antimicrobial peptides (AMPs) are promising leads for novel antibiotics; however, their activity is often compromised under physiological conditions. The purpose of this study was to determine the activity of α-peptide/β-peptoid peptidomimetics and AMPs against Escherichia coli and Staphylococcus aureus in the presence of human blood-derived matrices and immune effectors. The minimum inhibitory concentration (MIC) of two peptidomimetics against E. coli decreased by up to one order of magnitude when determined in 50% blood plasma as compared to MHB media. The MIC of a membrane-active AMP, LL-I/3, also decreased, whereas two intracellularly acting AMPs were not potentiated by plasma. Blood serum had no effect on activity against E. coli and neither matrix had an effect on activity against S. aureus. Unexpectedly, physiological concentrations of human serum albumin did not influence activity. Plasma potentiation was not mediated by an LL-37 analogue, lysozyme or hydrogen peroxide; however, plasma potentiation of activity was abolished when the complement system was heat-inactivated. Time-course experiments indicated that potentiation was due to plasma-mediated effects on bacterial cells prior to activities of peptidomimetics. The unexpected enhancement of antibacterial activity of peptidomimetics and AMPs under physiological conditions significantly increases the therapeutic potential of these compounds.     

The EPICS Family Bundle and its effects on stress and coping of families of critically Ill trauma patients

AimThe aim of this study was to evaluate impact of the EPICS Family Bundle on stress and coping.BackgroundCritical care nurses frequently deal with family stress, but may be without knowledge and skills needed to assist families to cope.MethodsA non-equivalent control group design was used, with a convenience sample of 84 family members of critically ill patients. During the control phase, participants completed tools measuring stress and coping. The intervention included use of the EPICS Family Bundle. After implementation, participants completed the same tools as those administered during the control phase. Outcomes were analyzed using independent-sample t-tests.ResultsThe experimental group had a significantly higher coping score on two subscales; and although not statistically significant, it was also improved on an additional four.ConclusionAfter implementation of the intervention, families experienced improved coping. The study may have lacked sufficient power to detect all differences.     

Using the cardiac depression scale in men recovering from coronary artery bypass surgery

Aims. To examine the utility and validate the use of the Cardiac Depression Scale in patients who had first‐time coronary artery bypass graft surgery. Background. The Beck Depression Inventory, though frequently used, may not be sufficiently sensitive for use in cardiac patients. The Cardiac Depression Scale has been shown to identify the range of depression in medical cardiac patients. Design. Survey. Methods. The Beck Depression Inventory and Cardiac Depression Scale were administered to 120 men at hospital discharge, as well as six, 12 and 36 weeks postoperatively. Cronbach’s α scores were calculated for the measures at each point. Changes in scores over time were analysed using repeated measures analysis of variance. Associations between the measures scores were calculated using Pearson product–moment correlations. Agreement between the measures’ dichotomised scores (depression/no depression) was examined using Cohen’s Kappa statistic. Results. Internal consistency was similar for the Beck Depression Inventory (0·793–0·904) and Cardiac Depression Scale (0·859–0·910). Depression scores decreased over time with the Beck Depression Inventory [F(2·50, 175·29) = 22·27, p < 0·001] and Cardiac Depression Scale [F(2·68, 190·37) = 13·18, p < 0·001]. The measures had similar power [Cohen’s f = 0·65 (Beck Depression Inventory) and 0·43 (Cardiac Depression Scale)] to reveal changes over time. The continuous scores were highly correlated at each point [0·737 (p < 0·001)–0·819 (p < 0·001)]. However, when dichotomised scores were compared, the chance corrected level of agreement was less impressive [0·198 (p = 0·014)–0·381 (p < 0·001)]. Conclusions. The Cardiac Depression Scale may have utility for use with surgical cardiac patients. However, continued examination of this measure of depression is warranted. Relevance to clinical practice. Given the prevalence of depression and its negative impact on coronary artery disease, it is important to identify even mild depression in cardiac patients. Using a measure of depression specifically for cardiac patients, rather than a generic measure, may best accomplish this goal.     

Phenotypic and epidemiologic correlates of auxotype in Neisseria gonorrhoeae.

Previous studies from Seattle, Wash., suggested that strains of Neisseria gonorrhoeae which require arginine, hypoxanthine, and uracil (Arg-Hyx-Ura- auxotype) are unifomly highly susceptible to penicillin G, are relatively resistant to complement-dependent killing by heated, pooled human serum, and are associated with disseminated gonococcal infection. For further study of the epidemiology of these strains and for analysis of the susceptibility to penicillin, serum sensitivity, and the nutritional requirements of gonococcal isolates from other cities, a survey was made of urethral and cervical strains isolated in 1972--1974 from 50 randomly selected pateit-s with uncomplicated gonorrhea from each of nine cities. Arg-Hyx-Ura-strains represented greater than 50% of isolates from Seattle and Des Moines, Iowa, 22% of isolates from Denver, Colo., and Dayton, Ohio, and less than or equal to 12% of the isolates from Boston, Mass., Newark, N.J., Norfork, Va., Miami, Fla., and Oakland, Calif. Arg-Hyx-Ura- strains were recovered from 42% of white and 9% of black patients (P less than 0.001), and clincis with the highest incidences of these strains had the highest proportion of white patients among those with gonorrhea. Arg-Hyx-Ura- strains were all susceptible to less than or equal to 0.125 microgram of penicillin G/ml and were more resistant than strains with other auxotypes to killing by heat-inactivated human serum plus complement (P less than 0.001).     

Dynamic endocrine responses to stress: evidence for energetic constraints and status dependence in breeding male green turtles

During reproduction, male vertebrates may exhibit a continuum of interactions between sex and adrenal steroids during stressful events, the outcome of which may be important in either reducing or promoting male reproductive success. We studied adult male green turtles (Chelonia mydas) to examine if they altered plasma corticosterone (CORT) and androgen levels in response to a standardized capture/restraint stressor as potential mechanisms to maintain reproductive activity during stressful events. At the population level, we found that migrant breeding males had a significantly smaller CORT response to the capture/restraint stressor compared to nonbreeding males and that this decreased response coincided with the generally poorer body condition of migrant breeders. In contrast, plasma androgen levels decreased significantly in response to the capture/restraint stressor in migrant breeding males, but not in nonbreeding and pre-migrant breeding males. For individual migrant breeding males, the magnitude of their CORT and androgen responses to the capture/restraint stressor was highly correlated with their body condition and body length, respectively. Our results demonstrate that male green turtles exhibit complex interactions in their endocrine responses to a capture/restraint stressor and that variation in these interactions is associated with differences in males' reproductive, energetic, and physical state. We hypothesize that interplay between physical status and plasma hormone responses to stressors could have important consequences for male green turtle reproduction.