The burnout syndrome among nurses in an urban acute care hospital

Three hundred fifty-four registered nurses from an urban acute care hospital were examined through self-report questionnaires. Nurses from trauma care, critical care and non-critical care nursing specialties participated in the study. The study focuses were (1) whether sociodemographic characteristics were significantly related to burnout; (2) what was the prevalence estimate of burnout among the population; (3) whether burnout levels differed depending upon nursing specialties and; (4) whether burnout as related to nursing stress, work environment, and work relations was mediated by sociodemographic characteristics.^ Race, age, marital status, education, seniority, rank, nursing education, and birthplace were significantly related to one or more aspects of burnout in the total population. With emotional exhaustion alone the prevalence of burnout was 62%. Using emotional exhaustion and depersonalization combined with reduced sense of personal accomplishment as a measure of burnout, thirty-four percent of the nurses were either in the pre-burnout phase or burned out. The relative importance of sociodemographic characteristics indicated that experience and race were highly significant risk factors.^ Burnout levels differed significantly depending upon nursing specialty. Specifically, levels of emotional exhaustion and depersonalization differed significantly between trauma care and critical care, and trauma care and non-critical care. Personal accomplishment did not differ depending upon nursing specialty. Critical care nurses did not differ significantly from non-critical care nurses on aspect of burnout.^ Race, marital status, education, seniority and rank were significant mediators of emotional exhaustion and depersonalization. The study offers possible explanations for the mediating effect of sociodemographic characteristics on nursing stress, work environment, work relations, emotional exhaustion and depersonalization. ^

Generalized resistance resources of informal caregivers: A study of demands for care, competing demands, perception of burden and cognitive stress

This study examines the relationship among psychological resources (generalized resistance resources), care demands (demands for care, competing demands, perception of burden) and cognitive stress in a selected population of primary family caregivers. The study utilizes Antonovsky's Salutogenic Model of Health, specifically the concept of generalized resistance resources (GRRs), to analyze the relative effect of these resources on mediating cognitive stress, controlling for other care demands. The study is based on a sample of 784 eligible caregivers who (1) were relatives, (2) had the main responsibility for care, defined as a primary caregiver, and (3) provided a scaled stress score for the amount of overall care given to the care recipient (family member). The sample was drawn from the 1982 National Long-Term Care Survey (NLTCS) of individuals who assisted a given NLTCS sample person with ADL limitations.^ The study tests the following hypotheses: (a) There will be a negative relationship between generalized resistance resources (GRRs) and cognitive stress controlling for care demands (demands for care, competing demands, and perceptions of burden); (b) of the specific GRRs (material, cognitive, social, cultural-environmental) the social domain will represent the most significant factor predicting a decrease in cognitive stress; and (c) the social domain will be more significant for the female than the male primary family caregiver in decreasing cognitive stress.^ The study found that GRRs had a statistically significant mediating effect on cognitive stress, but the GRRs were a less significant predictor of stress than perception of burden and demands for care. Thus, although the analysis supported the underlying hypothesis, the specific hypothesis regarding GRRs' greater significance in buffering cognitive stress was not supported. Second, the results did not demonstrate the statistical significance or differences among the GRR domains. The hypothesis that the social GRR domain was most significant in mediating stress of family caregivers was not supported. Finally, the results confirmed that there are differences in the importance of social support help in mediating stress based on gender. It was found that gender and social support help were related to cognitive stress and gender had a statistically significant interaction effect with social support help. Implications for clinical practice, public health policy, and research are discussed. ^

Longitudinal dyadic data analysis of stroke survivors and their spousal caregivers

Approximately 795,000 new and recurrent strokes occur each year. Because of the resulting functional impairment, stroke survivors are often discharged into the care of a family caregiver, most often their spouse. This dissertation explored the effect that mutuality, a measure of the perceived positive aspects of the caregiving relationship, had on the stress and depression of 159 stroke survivors and their spousal caregivers over the first 12 months post discharge from inpatient rehabilitation. Specifically, cross-lagged regression was utilized to investigate the dyadic, longitudinal relationship between caregiver and stroke survivor mutuality and caregiver and stroke survivor stress over time. Longitudinal meditational analysis was employed to examine the mediating effect of mutuality on the dyads’ perception of family function and caregiver and stroke survivor depression over time.^ Caregivers’ mutuality was found to be associated with their own stress over time but not the stress of the stroke survivor. Caregivers who had higher mutuality scores over the 12 months of the study had lower perceived stress. Additionally, a partner effect of stress for the stroke survivor but not the caregiver was found, indicating that stroke survivors’ stress over time was associated with caregivers’ stress but caregivers’ stress over time was not significantly associated with the stress of the stroke survivor.^ This dissertation did not find mutuality to mediate the relationship between caregivers’ and stroke survivors’ perception of family function at baseline and their own or their partners’ depression at 12 months as hypothesized. However, caregivers who perceived healthier family functioning at baseline and stroke survivors who had higher perceived mutuality at 12 months had lower depression at one year post discharge from inpatient rehabilitation. Additionally, caregiver mutuality at 6 months, but not at baseline or 12 months, was found to be inversely related to caregiver depression at 12 months.^ These findings highlight the interpersonal nature of stress in the context of caregiving, especially among spousal relationships. Thus, health professionals should encourage caregivers and stroke survivors to focus on the positive aspects of the caregiving relationship in order to mitigate stress and depression. ^

Caspase 8: Mediating the effects of a novel proteasome inhibitor, NPI-0052

Targeting the proteasome with the sole FDA approved proteasome inhibitor (PI), bortezomib, has been fruitful in specific cancers. Its success has generated an interest in next-generation PIs that might have a therapeutic advantage in cancers, such as leukemia, where bortezomib monotherapy was less effective. This study focuses on a novel, clinically relevant PI, NPI-0052. Experiments show that NPI-0052 targets chymotrypsin- and caspase-like activities more potently than the trypsin-like activity in leukemia cells. NPI-0052 induced apoptosis, as determined by caspase-3 activation and DNA fragmentation. Using caspase inhibitors and caspase-8 (I9.2) or FADD (I2.1) deficient cells revealed that caspase-8 was essential for NPI-0052-induced apoptosis. NPI-0052 killed cells via a caspase-8-tBid-mitochondrial pathway, relying on caspase-8, whereas bortezomib relies on several caspases. NPI-0052 increased reactive oxygen species (ROS) levels, which contributed towards cytotoxicity since an antioxidant conferred protection. To improve the clinical efficacy of PIs, NPI-0052 was combined with epigenetic anti-cancer agents, histone deacetylase inhibitors (HDACi). NPI-0052 with MS-275 or vorinostat (FDA approved HDACi), synergistically induced apoptosis more effectively than an HDACi/bortezomib regimen in Jurkat cells. Caspase-8 and ROS contributed towards NPI-0052/HDACi cytotoxicity and caspase-8 mediated superoxide production by NPI-0052 or NPI-0052/HDACi. The proximal targets of these agents: proteasome activity and histone acetylation were examined to determine if they contributed towards synergistic effects. HDACi targeted proteasomal β subunits and corresponding catalytic activities responsible for degrading proteins. Immunoblotting showed increases in histone-H3 expression and its acetylation with NPI-0052 or NPI-0052/HDACi in Jurkat and primary cells. Importantly, the hyper-acetylation by NPI-0052 was not detected with bortezomib, suggesting that this effect may be unique to NPI-0052. An antioxidant attenuated histone-H3 expression and acetylation induced by NPI-0052 alone or with HDACi. Furthermore, the hyper-acetylation by NPI-0052 relied on caspase-8. These novel results show that a PI is eliciting classical epigenetic alterations, demonstrated by hyper-acetylation of histone-H3. This alteration was oxidant and caspase-8 dependent. Overall, results reveal that caspase-8 mediates many effects induced by NPI-0052. Data show overlapping activities by NPI-0052 and HDACi which are contributing, along with caspase-8 activation and oxidative stress, to cytotoxic interactions in leukemia cells, reinforcing the potential clinical utility of combining these two compounds. ^

THE EFFECT OF FAMILY ENVIRONMENT FACTORS IN THE ETIOLOGY OF CHILD ABUSE

Twenty-three abusing couples were compared with a matched group of 23 non-abusing couples in terms of stress levels and family environment factors (cohesion, expressiveness, conflict, independence, achievement orientation, organization, control) which might mediate the response of abuse to stress. Parents who had physically abused their children were found to have significantly greater stress, conflict, and control and a significantly lower level of cohesion, independence, and achievement orientation than non-abusing parents. However, none of the mediating effects of the family environment factors reached the level of significance. ^

Role of TRP Channels in Mediating the Calcium Signaling Response of Brain Endothelial Cells to Mechanical Stretch

Traumatic brain injury (TBI) often results in disruption of the blood brain barrier (BBB), which is an integral component to maintaining the central nervous system homeostasis. Recently cytosolic calcium levels ([Ca2+]i), observed to elevate following TBI, have been shown to influence endothelial barrier integrity. However, the mechanism by which TBI-induced calcium signaling alters the endothelial barrier remains unknown. In the present study, an in vitro BBB model was utilized to address this issue. Exposure of cells to biaxial mechanical stretch, in the range expected for TBI, resulted in a rapid cytosolic calcium increase. Modulation of intracellular and extracellular Ca2+ reservoirs indicated that Ca2+ influx is the major contributor for the [Ca2+]i elevation. Application of pharmacological inhibitors was used to identify the calcium-permeable channels involved in the stretch-induced Ca2+ influx. Antagonist of transient receptor potential (TRP) channel subfamilies, TRPC and TRPP, demonstrated a reduction of the stretch-induced Ca2+ influx. RNA silencing directed at individual TRP channel subtypes revealed that TRPC1 and TRPP2 largely mediate the stretch-induced Ca2+ response. In addition, we found that nitric oxide (NO) levels increased as a result of mechanical stretch, and that inhibition of TRPC1 and TRPP2 abolished the elevated NO synthesis. Further, as myosin light chain (MLC) phosphorylation and actin cytoskeleton rearrangement are correlated with endothelial barrier disruption, we investigated the effect mechanical stretch had on the myosin-actin cytoskeleton. We found that phosphorylated MLC was increased significantly by 10 minutes post-stretch, and that inhibition of TRP channel activity or NO synthesis both abolished this effect. In addition, actin stress fibers formation significantly increased 2 minutes post-stretch, and was abolished by treatment with TRP channel inhibitors. These results suggest that, in brain endothelial cells, TRPC1 and TRPP2 are activated by TBI-mechanical stress and initiate actin-myosin contraction, which may lead to disruption of the BBB.

The Influence of Immunization Route on the Adjuvant Effect of alpha-Galactosylceramide

Potent vaccine formulations ideally include adjuvants to activate innate immune responses and enhance antigen-specific adaptive immunity. The synthetic glycolipid alpha-Galactosylceramide (α-GalCer) effectively activates the innate immune mediating NKT cells to produce cytokines and activate downstream immune cells, resulting in development of humoral and cell mediated immune responses to co-administered antigens. While a single intravenous immunization of α-GalCer strongly activates NKT cells, multiple doses by this route are well documented to induce anergy in NKT cells. Anergy is defined as the deficiency in NKT proliferation and cytokine production, including IL-4 and IFNγ. However, our studies have shown that two doses of α-GalCer administered intranasally by the intranasal route leads to reactivation of NKT cells and improved adaptive immune responses after each subsequent dose. I therefore investigated the role of multiple routes of immunization in activation of NKT cells, i.e. anergy versus repeated activation. Specifically, I hypothesized that the differential capacity of NKT cells to produce IFNγ, as a result of route of immunization with α-GalCer, influences the induction of adaptive immune responses to co-administered antigen. Our experimental design utilizes the observation that intranasal immunization primarily induces immune responses in the lungs while intravenous immunization induces responses in the liver. Using intracellular cytokine staining for IFNγ production and Elispot analyses for determining NKT and T cell activation, respectively, it was determined that administering two consecutive intravenous doses resulted in anergy to NKT cells (no IFNγ production) in the liver and lack of adaptive immunity while second immunization by the intranasal route overcame anergy in the lung. The outcome in the other tissues analyzed was mixed and could be the result of tissue microenvironment among others possible reasons. When intranasal dosing preceded systemic, NKT cells were reactivated to produce IFNγ and induced positive adaptive immune responses in the responding lung tissue. These results indicate that the mechanism by which mucosal and systemic immunization routes activate NKT cells may differ in that there is a differential tissue-specific effect induced by each route. Future studies are necessary to determine the reason for these tissue-specific effects and how they relate to NKT cell activation.