Neutralization of Mitochondrial Superoxide by Superoxide Dismutase 2 Promotes Bacterial Clearance and Regulates Phagocyte Numbers in Zebrafish

Mitochondria are known primarily as the location of the electron transport chain and energy production in cells. More recently, mitochondria have been shown to be signaling centers for apoptosis and inflammation. Reactive oxygen species (ROS) generated as by-products of the electron transport chain within mitochondria significantly impact cellular signaling pathways. Because of the toxic nature of ROS, mitochondria possess an antioxidant enzyme, superoxide dismutase 2 (SOD2), to neutralize ROS. If mitochondrial antioxidant enzymes are overwhelmed during severe infections, mitochondrial dysfunction can occur and lead to multiorgan failure or death. Pseudomonas aeruginosa is an opportunistic pathogen that can infect immunocompromised patients. Infochemicals and exotoxins associated with P. aeruginosa are capable of causing mitochondrial dysfunction. In this work, we describe the roles of SOD2 and mitochondrial ROS regulation in the zebrafish innate immune response to P. aeruginosa infection. sod2 is upregulated in mammalian macrophages and neutrophils in response to lipopolysaccharide in vitro, and sod2 knockdown in zebrafish results in an increased bacterial burden. Further investigation revealed that phagocyte numbers are compromised in Sod2-deficient zebrafish. Addition of the mitochondrion-targeted ROS-scavenging chemical MitoTEMPO rescues neutrophil numbers and reduces the bacterial burden in Sod2-deficient zebrafish. Our work highlights the importance of mitochondrial ROS regulation by SOD2 in the context of innate immunity and supports the use of mitochondrion-targeted ROS scavengers as potential adjuvant therapies during severe infections.     

Constraints on Social Activities of Care-Givers: A Sociological Perspective

Newer policies of community care for those with disabilities have resulted in the home becoming the usual site of care. Policy makers must now give attention to the needs of those at home giving this care. This article explores the constraints on sociability opportunities of 73 mothers who were caring for children with disabilities. These opportunities are often built into leisure pursuits for women without caring responsibilities. However, choice of out-of-house leisure activity was circumscribed for the mothers in this study and their reported leisure activities revolved around home and neighbourhood. Even these sites offered limited scope for sociability because of the way in which caring affected domestic space and because of the characteristics of the modern Australian suburb. It is argued in this paper that personal time and personal domestic space are needed by care-givers so their sociability needs can be fulfilled. An understanding of the constraints imposed by use of the home as a place of care may make possible the planning of a rearrangement of domestic space to increase sociability opportunities for carers.     

Patterns of care: an analysis of the quality of nutritional care routinely provided to elderly hospitalized veterans

To assess the adequacy of the nutritional care provided, a prospective noninterventional study was carried out on 250 randomly selected patients aged 65 and over who were admitted to a Veterans Administration Hospital. Of this group, 97 patients (39%) were found to be at high risk of having clinically significant protein-energy malnutrition. In 43 cases (17%), an assessment of the patient's nutritional status was not possible because the available data were inadequate. No patient had a diagnosis of malnutrition recorded on the problem list. Only 13 percent of the high-risk patients received some form of nutrition support therapy; 10 (10%) received oral supplements, and four (4%) were started on enteral feedings. Patients who received enteral feedings experienced a high rate of complications resulting from use of the feeding tubes. Over all, none of the high risk study patients received optimal nutrition support therapy. These findings indicate that elderly patients hospitalized in the Veterans Administration hospital in this study are usually not screened appropriately for protein-energy malnutrition, the diagnosis is frequently missed or ignored, and nutrition support therapy is underutilized and often ineffectually managed.