The Low Fall as a Surrogate Marker of Frailty Predicts Long-Term Mortality in Older Trauma Patients

Background

Frailty is associated with adverse outcomes including disability, mortality and risk of falls. Trauma registries capture a broad range of injuries. However, frail patients who fall comprise a large proportion of the injuries occurring in ageing populations and are likely to have different outcomes compared to non-frail injured patients. The effect of frail fallers on mortality is under-explored but potentially significant. Currently, many trauma registries define low falls as less than three metres, a height that is likely to include non-frailty falls. We hypothesized that the low fall from less than 0.5 metres, including same-level falls, is a surrogate marker of frailty and predicts long-term mortality in older trauma patients.

Methods

Using data from the Singapore National Trauma Registry, 2011–2013, matched till September 2014 to the death registry, we analysed adults aged over 45 admitted via the emergency department in public hospitals sustaining blunt injuries with an injury severity score (ISS) of 9 or more, excluding isolated hip fractures from same-level falls in the over 65. Patients injured by a low fall were compared to patients injured by high fall and other blunt mechanisms. Logistic regression was used to analyze 12-month mortality, controlling for mechanism of injury, ISS, revised trauma score (RTS), co-morbidities, gender, age and age-gender interaction. Different low fall height definitions, adjusting for injury regions, and analyzing the entire adult cohort were used in sensitivity analyses and did not change our findings.

Results

Of the 8111 adults in our cohort, patients who suffered low falls were more likely to die of causes unrelated to their injuries (p<0.001), compared to other blunt trauma and higher fall heights. They were at higher risk of 12-month mortality (OR 1.75, 95% CI 1.18–2.58, p = 0.005), independent of ISS, RTS, age, gender, age-gender interaction and co-morbidities. Falls that were higher than 0.5m did not show this pattern. Males were at higher risk of mortality after low falls. The effect of age on mortality started at age 55 for males, and age 70 for females, and the difference was attributable to the additional mortality in male low-fallers.

Conclusions

The low fall mechanism can optimize prediction of long-term mortality after moderate and severe injury, and may be a surrogate marker of frailty, complementing broader-based studies on aging.     

Allometric deviations of plasma carotenoids in raptors

Because large species ingest proportionally less food than small ones, it may be predicted that they should incorporate relatively fewer carotenoids to a proportionally equal volume of blood. However, some species may increase their levels of circulating carotenoids by ingesting unusual food. We tested whether the plasma concentration of carotenoids scales to the three‐quarter power of mass in nine predatory and scavenger raptor species. No significant allometric relationships were found due to the unusually high concentrations of carotenoids in the Egyptian Vulture Neophron percnopterus and the Andean condor Vultur gryphus. To assess whether these two species deviate from the allometric rule through the exploitation of unusual sources of carotenoids, or due to a physiological adaptation to improve the uptake of carotenoids, we determined allometric patterns in individuals of these two species kept in captivity with an exclusive diet of flesh. Our results provided support for the allometric rule because the slope of the allometric equation did not differ from a three‐quarter exponent when carotenoid levels of the two outliers were replaced by those of captive birds. This adjustment to the allometric rule suggests a lack of any physiological adaptation to improve the uptake of the low concentrations of carotenoids contained in flesh. Differences between species in carotenoid incorporation into the bloodstream may be ultimately due to contrasting evolutionary history, physiology and associated colour‐signalling strategies, but proximately due to the acquisition of these micronutrients from both usual and unusual dietary sources.     

<Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> inhibits <Emphasis Type="Italic">in-vitro Candida</Emphasis> biofilm development

Background  

Elucidation of the communal behavior of microbes in mixed species biofilms may have a major impact on understanding infectious diseases and for the therapeutics. Although, the structure and the properties of monospecies biofilms and their role in disease have been extensively studied during the last decade, the interactions within mixed biofilms consisting of bacteria and fungi such as Candida spp. have not been illustrated in depth. Hence, the aim of this study was to evaluate the interspecies interactions of Pseudomonas aeruginosa and six different species of Candida comprising C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis, and C. dubliniensis in dual species biofilm development.     

Proteomic approaches to identifying carbonylated proteins in brain tissue

Oxidative stress plays a critical role in the pathogenesis of a number of diseases. The carbonyl end products of protein oxidation are among the most commonly measured markers of oxidation in biological samples. Protein carbonyl functional groups may be derivatized with 2,4-dinitrophenylhydrazine (DNPH) to render a stable 2,4-dinitrophenylhydrazone-protein (DNP-protein) and the carbonyl contents of individual proteins then determined by two-dimensional electrophoresis followed by immunoblotting using specific anti-DNP antibodies. Unfortunately, derivatization of proteins with DNPH could affect their mass spectrometry (MS) identification. This problem can be overcome using nontreated samples for protein identification. Nevertheless, derivatization could also affect their mobility, which might be solved by performing the derivatization step after the initial electrophoresis. Here, we compare two-dimensional redox proteome maps of mouse cerebellum acquired by performing the DNPH derivatization step before or after electrophoresis and detect differences in protein patterns. When the same approach is used for protein detection and identification, both methods were found to be useful to identify carbonylated proteins. However, whereas pre-DNPH derivatized proteins were successfully analyzed, high background staining complicated the analysis when the DNPH reaction was performed after transblotting. Comparative data on protein identification using both methods are provided.     

Plasma proteome analysis in HTLV-1-associated myelopathy/tropical spastic paraparesis

Background

A new subgroup of HIV-1, designated Group P, was recently detected in two unrelated patients of Cameroonian origin. HIV-1 Group P phylogenetically clusters with SIVgor suggesting that it is the result of a cross-species transmission from gorillas. Until today, HIV-1 Group P has only been detected in two patients, and its degree of adaptation to the human host is largely unknown. Previous data have shown that pandemic HIV-1 Group M, but not non-pandemic Group O or rare Group N viruses, efficiently antagonize the human orthologue of the restriction factor tetherin (BST-2, HM1.24, CD317) suggesting that primate lentiviruses may have to gain anti-tetherin activity for efficient spread in the human population. Thus far, three SIV/HIV gene products (vpu, nef and env) are known to have the potential to counteract primate tetherin proteins, often in a species-specific manner. Here, we examined how long Group P may have been circulating in humans and determined its capability to antagonize human tetherin as an indicator of adaptation to humans.

Results

Our data suggest that HIV-1 Group P entered the human population between 1845 and 1989. Vpu, Env and Nef proteins from both Group P viruses failed to counteract human or gorilla tetherin to promote efficient release of HIV-1 virions, although both Group P Nef proteins moderately downmodulated gorilla tetherin from the cell surface. Notably, Vpu, Env and Nef alleles from the two HIV-1 P strains were all able to reduce CD4 cell surface expression.

Conclusions

Our analyses of the two reported HIV-1 Group P viruses suggest that zoonosis occurred in the last 170 years and further support that pandemic HIV-1 Group M strains are better adapted to humans than non-pandemic or rare Group O, N and P viruses. The inability to antagonize human tetherin may potentially explain the limited spread of HIV-1 Group P in the human population.     

Parthenocarpic fruit set in triploid watermelon induced by CPPUand 2,4-D applications

The localized application of the synthetic cytokinin CPPU ((2-chloro-4-pyridyl)-N-phenyl urea) to ovaries at flower opening was as effective as free pollination in setting parthenocarpic fruit in the triploid watermelon cultivar ‘Reina de Corazones’, and increased yield per unit land area by at least 50%, simply due to the lack of requirement for diploid pollen producing plants within the orchard. The application of the synthetic auxin 2,4-D (2,4-dichlorophenoxy acetic acid) as a full coverage spray, was also effective in setting fruit; total yield was however 10% smaller than in the CPPU-treated plots, but the cost of application was much less expensive. These applications had no adverse effect on fruit quality, and their effectiveness in commercial watermelon production was evaluated over 4 years. Localized applications of 2,4-D to ovaries were less effective in setting fruit, and increased hollow fruit.     

Feeling the pressure in mammalian somatosensation

Mechanoreceptor cells of the somatosensory system initiate the perception of touch and pain. Molecules required for mechanosensation have been identified from invertebrate neurons, and recent functional studies indicate that ion channels of the transient receptor potential and degenerin/epithelial Na+ channel families are likely to be transduction channels. The expression of related channels in mammalian somatosensory neurons has fueled the notion that these channels mediate mechanotransduction in vertebrates; however, genetic disruption and heterologous expression have not yet revealed a direct role for any of these candidates in somatosensory mechanotransduction. Thus, new systems are needed to define the function of these ion channels in somatosensation and to pinpoint molecules or signaling pathways that underlie mechanotransduction in vertebrates.