Body composition, changing physiological functions and nutrient requirements of the elderly

Age has an important impact on body composition. The decreases of lean body mass and total body water accompanied by an increase of body fat are the most relevant changes leading to a reduction of the basal metabolic rate. Due to this and the fact that elderly people are generally less physically active, energy needs are lower. However, the requirements for most micronutrients are not reduced. Indeed, impaired absorption of some vitamins and minerals like cobalamin and calcium can cause deficiencies. An adequate calcium supply is particularly important as with ongoing age, bone mass decreases as well, making elderly prone to osteoporosis. The reduced ability to synthesize vitamin D and the lower sunlight exposure of many elderly further aggravate this issue. There is evidence to consider the supply of some important dietary antioxidants as critical in some elderly, namely vitamin C and beta-carotene as well as zinc. In light of age-related decreases in the activities of antioxidant enzymes, a sufficient supply of dietary antioxidants is important, especially as oxidative damage is thought to contribute to the deteriorating processes associated with aging and promote cardiovascular disease, cognitive disorders, cancer and diabetes mellitus that occur more frequently in older people. The first three are also associated with an insufficiency of folate, another critical nutrient in the elderly. Therefore, dietary guidelines should strive to optimize the immune function and reduce disease risk of the elderly.     

N-Chlorotaurine Exhibits Fungicidal Activity against Therapy-Refractory Scedosporium Species and Lomentospora prolificans

N-Chlorotaurine (NCT), a well-tolerated endogenous long-lived oxidant that can be applied topically as an antiseptic, was tested on its fungicidal activity against Scedosporium and Lomentospora, opportunistic fungi that cause severe infections with limited treatment options, mainly in immunocompromised patients. In quantitative killing assays, both hyphae and conidia of Scedosporium apiospermum, Scedosporium boydii, and Lomentospora prolificans (formerly Scedosporium prolificans) were killed by 55 mM (1.0%) NCT at pH 7.1 and 37°C, with a 1- to 4-log₁₀ reduction in CFU after 4 h and a 4- to >6-log₁₀ reduction after 24 h. The addition of ammonium chloride to NCT markedly increased this activity. LIVE/DEAD staining of conidia treated with 1.0% NCT for 0.5 to 3 h increased the permeability of the cell wall and membrane. Preincubation of the test fungi in 1.0% NCT for 10 to 60 min delayed the time to germination of conidia by 2 h to >12 h and reduced their germination rate by 10.0 to 100.0%. Larvae of Galleria mellonella infected with 1.0 × 10⁷ conidia of S. apiospermum and S. boydii died at a rate of 90.0 to 100% after 8 to 12 days. The mortality rate was reduced to 20 to 50.0% if conidia were preincubated in 1.0% NCT for 0.5 h or if heat-inactivated conidia were used. Our study demonstrates the fungicidal activity of NCT against different Scedosporium and Lomentospora species. A postantifungal effect connected with a loss of virulence occurs after sublethal incubation times. The augmenting effect of ammonium chloride can be explained by the formation of monochloramine.     

RESILIENCE AND RECOVERY IN AMERICAN SĀMOA: A CASE STUDY OF THE 2009 SOUTH PACIFIC TSUNAMI

Case study methodology was used to explore the culturally situated response and recovery efforts following a tsunami in American Sāmoa. Data indicated that cultural mechanisms were effective in meeting physical needs but insufficient to manage the emotional trauma caused by such a large‐scale event. Samoan cultural norms strongly discourage uncontrolled emotional expression outside of ritualized grieving events. Disruptions in social networks and activities, combined with a lack of available emotional support, resulted in significant psychological distress for many survivors. Sixteen months after the tsunami residents continued to exhibit numerous symptoms of posttraumatic stress. In response to this need for emotional support, some groups within American Sāmoa are setting an example of how their culture can adapt by forging new, culturally grounded methods for addressing emotional needs that arose in the wake of the tsunami. Findings are analyzed through the lens of the social support deterioration deterrence model and activity settings theory.     

Discovery and Characterization of Potential Prognostic Biomarkers for Dengue Hemorrhagic Fever

Half a million patients are hospitalized with severe dengue every year, many of whom would die without timely, appropriate clinical intervention. The majority of dengue cases are uncomplicated; however, 2–5% progress to severe dengue. Severe dengue cases have been reported with increasing frequency over the last 30 years. To discover biomarkers for severe dengue, we used surface-enhanced laser desorption/ionization time-of-flight mass spectrometry to analyze dengue virus positive serum samples from the acute phase of infection. Using this method, 16 proteins were identified as candidate biomarkers for severe dengue. From these 16 biomarkers, three candidates were selected for confirmation by enzyme-linked immunosorbent assay and Western blot: vitronectin (Vtn, 55.1 kDa), hemopexin (Hx, 52.4 kDa), and serotransferrin (Tf, 79.2 kDa). Vitronectin, Hx, and Tf best differentiated between dengue and severe dengue.     

Oxidative tissue injury in multiple sclerosis is only partly reflected in experimental disease models

Recent data suggest that oxidative injury may play an important role in demyelination and neurodegeneration in multiple sclerosis (MS). We compared the extent of oxidative injury in MS lesions with that in experimental models driven by different inflammatory mechanisms. It was only in a model of coronavirus-induced demyelinating encephalomyelitis that we detected an accumulation of oxidised phospholipids, which was comparable in extent to that in MS. In both, MS and coronavirus-induced encephalomyelitis, this was associated with massive microglial and macrophage activation, accompanied by the expression of the NADPH oxidase subunit p22phox but only sparse expression of inducible nitric oxide synthase (iNOS). Acute and chronic CD4⁺ T cell-mediated experimental autoimmune encephalomyelitis lesions showed transient expression of p22phox and iNOS associated with inflammation. Macrophages in chronic lesions of antibody-mediated demyelinating encephalomyelitis showed lysosomal activity but very little p22phox or iNOS expressions. Active inflammatory demyelinating lesions induced by CD8⁺ T cells or by innate immunity showed macrophage and microglial activation together with the expression of p22phox, but low or absent iNOS reactivity. We corroborated the differences between acute CD4⁺ T cell-mediated experimental autoimmune encephalomyelitis and acute MS lesions via gene expression studies. Furthermore, age-dependent iron accumulation and lesion-associated iron liberation, as occurring in the human brain, were only minor in rodent brains. Our study shows that oxidative injury and its triggering mechanisms diverge in different models of rodent central nervous system inflammation. The amplification of oxidative injury, which has been suggested in MS, is only reflected to a limited degree in the studied rodent models.     

Apolipoprotein M binds oxidized phospholipids and increases the antioxidant effect of HDL

ObjectiveOxidation of LDL plays a key role in the development of atherosclerosis. HDL may, in part, protect against atherosclerosis by inhibiting LDL oxidation. Overexpression of HDL-associated apolipoprotein M (apoM) protects mice against atherosclerosis through a not yet clarified mechanism. Being a lipocalin, apoM contains a binding pocket for small lipophilic molecules. Here, we report that apoM likely serves as an antioxidant in HDL by binding oxidized phospholipids, thus enhancing the antioxidant potential of HDL.Methods and resultsHDL was isolated from wild type mice, apoM-deficient mice, and two lines of apoM-Tg mice with ～2-fold and ～10-fold increased plasma apoM, respectively. Increasing amounts of HDL-associated apoM were associated with an increase in the resistance of HDL to oxidation with Cu²⁺ or 2,2′-azobis 2-methyl-propanimidamide, dihydrochloride (AAPH) and to an increased ability of HDL to protect human LDL against oxidation. Oxidized phospholipids, but not native phospholipids, quenched the intrinsic fluorescence of recombinant human apoM and the quenching could be competed with myristic acid suggesting selective binding of oxidized phospholipid in the lipocalin-binding pocket of apoM.ConclusionsThe results suggest that apoM can bind oxidized phospholipids and that it increases the antioxidant effect of HDL. This new mechanism may explain at least part of the antiatherogenic potential of apoM.