Cheating the locals: invasive mussels steal and benefit from the cooling effect of indigenous mussels

The indigenous South African mussel Perna perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. perna for collective thermoregulation. We investigated whether varying densities of P. perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. perna. This may have significant implications for predicting how the co-existence of these two species may change as global temperatures continue to rise

Amelioration of bleomycin-induced lung fibrosis in hamsters by dietary supplementation with taurine and niacin: biochemical mechanisms.

Interstitial pulmonary fibrosis induced by intratracheal instillation of bleomycin (BL) involves an excess production of reactive oxygen species, unavailability of adequate levels of NAD and ATP to repair the injured pulmonary epithelium, and an overexuberant lung collagen reactivity followed by deposition of highly cross-linked mature collagen fibrils resistant to enzymatic degradation. In the present study, we have demonstrated that dietary supplementation with taurine and niacin offered almost complete protection against the lung fibrosis in a multidose BL hamster model. The mechanisms for the protective effect of taurine and niacin are multifaceted. These include the ability of taurine to scavenge HOCl and stabilize the biomembrane; niacin's ability to replenish the BL-induced depletion of NAD and ATP; and the combined effect of taurine and niacin to suppress all aspects of BL-induced increases in the lung collagen reactivity, a hallmark of interstitial pulmonary fibrosis. It was concluded from the data presented at this Conference that the combined treatment with taurine and niacin, which offers a multipronged approach, will have great therapeutic potential in the intervention of the development of chemically induced interstitial lung fibrosis in animals and humans

Patchiness and Co-Existence of Indigenous and Invasive Mussels at Small Spatial Scales: The Interaction of Facilitation and Competition

Ecological theory predicts that two species with similar requirements will fail to show long-term co-existence in situations where shared resources are limiting, especially at spatial scales that are small relative to the size of the organisms. Two species of intertidal mussels, the indigenous Perna perna and the invasive Mytilus galloprovincialis, form mixed beds on the south coast of South Africa in a situation that has been stable for several generations of these species, even though these populations are often limited by the availability of space. We examined the spatial structure of these species where they co-exist at small spatial scales in the absence of apparent environmental heterogeneity at two sites, testing: whether conspecific aggregation of mussels can occur (using spatial Monte-Carlo tests); the degree of patchiness (using Korcak B patchiness exponent), and whether there was a relationship between percent cover and patchiness. We found that under certain circumstances there is non-random conspecific aggregation, but that in other circumstances there may be random distribution (i.e. the two species are mixed), so that spatial patterns are context-dependent. The relative cover of the species differed between sites, and within each site, the species with higher cover showed low Korcak B values (indicating low patchiness, i.e. the existence of fewer, larger patches), while the less abundant species showed the reverse, i.e. high patchiness. This relationship did not hold for either species within sites. We conclude that co-existence between these mussels is possible, even at small spatial scales because each species is an ecological engineer and, while they have been shown to compete for space, this is preceded by initial facilitation. We suggest that a patchy pattern of co-existence is possible because of a balance between direct (competitive) and indirect (facilitative) interactions

Enemies with benefits: parasitic endoliths protect mussels against heat stress

Positive and negative aspects of species interactions can be context dependant and strongly affected by environmental conditions. We tested the hypothesis that, during periods of intense heat stress, parasitic phototrophic endoliths that fatally degrade mollusc shells can benefit their mussel hosts. Endolithic infestation significantly reduced body temperatures of sun-exposed mussels and, during unusually extreme heat stress, parasitised individuals suffered lower mortality rates than nonparasitised hosts. This beneficial effect was related to the white discolouration caused by the excavation activity of endoliths. Under climate warming, species relationships may be drastically realigned and conditional benefits of phototrophic endolithic parasites may become more important than the costs of infestation

Global biogeography of SAR11 marine bacteria

The ubiquitous SAR11 bacterial clade is the most abundant type of organism in the worldĝ€™s oceans, but the reasons for its success are not fully elucidated. We analysed 128 surface marine metagenomes, including 37 new Antarctic metagenomes. The large size of the data set enabled internal transcribed spacer (ITS) regions to be obtained from the Southern polar region, enabling the first global characterization of the distribution of SAR11, from waters spanning temperatures ĝ̂'2 to 30°C. Our data show a stable co-occurrence of phylotypes within both ĝ€̃ tropicalĝ€™ (>20°C) and ĝ€̃ polarĝ€™ (<10°C) biomes, highlighting ecological niche differentiation between major SAR11 subgroups. All phylotypes display transitions in abundance that are strongly correlated with temperature and latitude. By assembling SAR11 genomes from Antarctic metagenome data, we identified specific genes, biases in gene functions and signatures of positive selection in the genomes of the polar SAR11ĝ€"genomic signatures of adaptive radiation. Our data demonstrate the importance of adaptive radiation in the organismĝ€™s ability to proliferate throughout the worldĝ€™s oceans, and describe genomic traits characteristic of different phylotypes in specific marine biomes. © 2012 EMBO and Macmillan Publishers Limited All rights reserved

Combined sedation with midazolam/propofol for gastrointestinal endoscopy in elderly patients

<p>Abstract</p> <p>Background</p> <p>Although gastrointestinal endoscopy with sedation is increasingly performed in elderly patients, data on combined sedation with midazolam/propofol are very limited for this age group.</p> <p>Methods</p> <p>We retrospectively analyzed 454 endoscopic procedures in 347 hospitalized patients ≥ 70 years who had received combined sedation with midazolam/propofol. 513 endoscopic procedures in 397 hospitalized patients < 70 years during the observation period served as controls. Characteristics of endoscopic procedures, co-morbidity, complications and mortality were compared.</p> <p>Results</p> <p>Elderly patients had a higher level of co-morbidity and needed lower mean propofol doses for sedation. We observed no major complication and no difference in the number of minor complications. The procedure-associated mortality was 0%; the 28-day mortality was significantly higher in the elderly (2.9% vs. 1.0%).</p> <p>Conclusions</p> <p>In this study on elderly patients with high level co-morbidity, a favourable safety profile was observed for a combined sedation with midazolam/propofol with a higher sensitivity to propofol in the elderly.</p

The REstart or STop Antithrombotics Randomised Trial (RESTART) after stroke due to intracerebral haemorrhage: study protocol for a randomised controlled trial

Background For adults surviving stroke due to spontaneous (non-traumatic) intracerebral haemorrhage (ICH) who had taken an antithrombotic (i.e. anticoagulant or antiplatelet) drug for the prevention of vaso-occlusive disease before the ICH, it is unclear whether starting antiplatelet drugs results in an increase in the risk of recurrent ICH or a beneficial net reduction of all serious vascular events compared to avoiding antiplatelet drugs. Methods/design The REstart or STop Antithrombotics Randomised Trial (RESTART) is an investigator-led, randomised, open, assessor-blind, parallel-group, randomised trial comparing starting versus avoiding antiplatelet drugs for adults surviving antithrombotic-associated ICH at 122 hospital sites in the United Kingdom. RESTART uses a central, web-based randomisation system using a minimisation algorithm, with 1:1 treatment allocation to which central research staff are masked. Central follow-up includes annual postal or telephone questionnaires to participants and their general (family) practitioners, with local provision of information about adverse events and outcome events. The primary outcome is recurrent symptomatic ICH. The secondary outcomes are: symptomatic haemorrhagic events; symptomatic vaso-occlusive events; symptomatic stroke of uncertain type; other fatal events; modified Rankin Scale score; adherence to antiplatelet drug(s). The magnetic resonance imaging (MRI) sub-study involves the conduct of brain MRI according to a standardised imaging protocol before randomisation to investigate heterogeneity of treatment effect according to the presence of brain microbleeds. Recruitment began on 22 May 2013. The target sample size is at least 720 participants in the main trial (at least 550 in the MRI sub-study). Discussion Final results of RESTART will be analysed and disseminated in 2019. Trial registration ISRCTN71907627 (www.isrctn.com/ISRCTN71907627). Prospectively registered on 25 April 2013

The utility of Aspirin in dukes C and high risk dukes B colorectal cancer - The ASCOLT study: study protocol for a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>High quality evidence indicates that aspirin is effective in reducing colorectal polyps; and numerous epidemiological studies point towards an ability to prevent colorectal cancer. However the role of Aspirin as an adjuvant agent in patients with established cancers remains to be defined. Recently a nested case-control study within the Nurses Health cohort suggested that the initiation of Aspirin <it>after </it>the diagnosis of colon cancer reduced overall colorectal cancer specific mortality. Although this data is supportive of Aspirin's biological activity in this disease and possible role in adjuvant therapy, it needs to be confirmed in a randomized prospective trial.</p> <p>Methods/Design</p> <p>We hypothesize through this randomized, placebo-controlled adjuvant study, that Aspirin in patients with dukes C or high risk dukes B colorectal cancer (ASCOLT) can improve survival in this patient population over placebo control. The primary endpoint of this study is Disease Free Survival and the secondary Endpoint is 5 yr Overall Survival. This study will randomize eligible patients with Dukes C or high risk Dukes B colorectal cancer, after completion of surgery and standard adjuvant chemotherapy (+/- radiation therapy for rectal cancer patients) to 200 mg Aspirin or Placebo for 3 years. Stratification factors include study centre, rectal or colon cancer stage, and type of adjuvant chemotherapy (exposed/not exposed to oxaliplatin). After randomization, patient will be followed up with 3 monthly assessments whilst on study drug and for a total of 5 years. Patients with active peptic ulcer disease, bleeding diathesis or on treatment with aspirin or anti-platelet agents will be excluded from the study.</p> <p>Discussion</p> <p>This study aims to evaluate Aspirin's role as an adjuvant treatment in colorectal cancer. If indeed found to be beneficial, because aspirin is cheap, accessible and easy to administer, it will positively impact the lives of many individuals in Asia and globally.</p> <p>Trials Registration</p> <p>Clinicaltrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00565708">NCT00565708</a></p

Flavonoids from Pterogyne nitens Inhibit Hepatitis C Virus Entry

Hepatitis C virus (HCV) is one of the leading causes of liver diseases and transplantation worldwide. The current available therapy for HCV infection is based on interferon-α, ribavirin and the new direct-acting antivirals (DAAs), such as NS3 protease and NS5B polymerase inhibitors. However, the high costs of drug design, severe side effects and HCV resistance presented by the existing treatments demonstrate the need for developing more efficient anti-HCV agents. This study aimed to evaluate the antiviral effects of sorbifolin (1) and pedalitin (2), two flavonoids from Pterogyne nitens on the HCV replication cycle. These compounds were investigated for their anti-HCV activities using genotype 2a JFH-1 subgenomic replicons and infectious virus systems. Flavonoids 1 and 2 inhibited virus entry up to 45.0% and 78.7% respectively at non-cytotoxic concentrations. The mechanism of the flavonoid 2 block to virus entry was demonstrated to be by both the direct action on virus particles and the interference on the host cells. Alternatively, the flavonoid 1 activity was restricted to its virucidal effect. Additionally, no inhibitory effects on HCV replication and release were observed by treating cells with these flavonoids. These data are the first description of 1 and 2 possessing in vitro anti-HCV activity

A Prospective Study of Aspirin Use and the Risk of Gastrointestinal Bleeding in Men

Data regarding the influence of dose and duration of aspirin use on risk of gastrointestinal bleeding are conflicting.We conducted a prospective cohort study of 32,989 men enrolled in the Health Professionals Follow-up Study (HPFS) in 1994 who provided biennial aspirin data. We estimated relative risk of major gastrointestinal bleeding requiring hospitalization or a blood transfusion.During 14 years of follow-up, 707 men reported an episode of major gastrointestinal bleeding over 377,231 person-years. After adjusting for risk factors, regular aspirin use (≥2 times/week) had a multivariate relative risk (RR) of gastrointestinal bleeding of 1.32 (95% confidence interval [CI], 1.12-1.55) compared to non-regular use. The association was particularly evident for upper gastrointestinal bleeding (multivariate RR, 1.49; 95% CI, 1.16-1.92). Compared to men who denied any aspirin use, multivariate RRs of upper gastrointestinal bleeding were 1.05 (95% CI 0.71-1.52) for men who used 0.5-1.5 standard tablets/week, 1.31 (95% CI 0.88-1.95) for 2-5 aspirin/week, 1.63 (95% CI, 1.15-2.32) for 6-14 aspirin/week and 2.40 (95% CI, 1.10-5.22) for >14 aspirin/week (P(trend)<0.001). The relative risk also appeared to be dose-dependent among short-term users <5 years; P(trend)<.001) and long-term users (≥5 years; P(trend) = 0.015). In contrast, after controlling for dose, increasing duration of use did not appear to be associated with risk (P(trend) = 0.749).Regular aspirin use increases the risk of gastrointestinal bleeding, especially from the upper tract. However, risk of bleeding appears to be more strongly related to dose than to duration of use. Risk of bleeding should be minimized by using the lowest effective dose among short-term and long-term aspirin users