601 research outputs found

    Human mandibular shape is associated with masticatory muscle force

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    Understanding how and to what extent forces applied to the mandible by the masticatory muscles influence its form, is of considerable importance from clinical, anthropological and evolutionary perspectives. This study investigates these questions. Head CT scans of 382 adults were utilized to measure masseter and temporalis muscle cross-sectional areas (CSA) as a surrogate for muscle force, and 17 mandibular anthropometric measurements. Sixty-two mandibles of young individuals (20-40 years) whose scans were without artefacts (e.g., due to tooth filling) were segmented and landmarked for geometric morphometric analysis. The association between shape and muscle CSA (controlled for size) was assessed using two-block partial least squares analysis. Correlations were computed between mandibular variables and muscle CSAs (all controlled for size). A significant association was found between mandibular shape and muscle CSAs, i.e. larger CSAs are associated with a wider more trapezoidal ramus, more massive coronoid, more rectangular body and a more curved basal arch. Linear measurements yielded low correlations with muscle CSAs. In conclusion, this study demonstrates an association between mandibular muscle force and mandibular shape, which is not as readily identified from linear measurements. Retrodiction of masticatory muscle force and so of mandibular loading is therefore best based on overall mandibular shape

    Implication of 4E-BP1 protein dephosphorylation and accumulation in pancreatic cancer cell death induced by combined gemcitabine and TRAIL

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    Pancreatic cancer cells show varying sensitivity to the anticancer effects of gemcitabine. However, as a chemotherapeutic agent, gemcitabine can cause intolerably high levels of toxicity and patients often develop resistance to the beneficial effects of this drug. Combination studies show that use of gemcitabine with the pro-apoptotic cytokine TRAIL can enhance the inhibition of survival and induction of apoptosis of pancreatic cancer cells. Additionally, following combination treatment there is a dramatic increase in the level of the hypophosphorylated form of the tumour suppressor protein 4E-BP1. This is associated with inhibition of mTOR activity, resulting from caspase-mediated cleavage of the Raptor and Rictor components of mTOR. Use of the pan-caspase inhibitor Z-VAD-FMK indicates that the increase in level of 4E-BP1 is also caspase-mediated. ShRNA-silencing of 4E-BP1 expression renders cells more resistant to cell death induced by the combination treatment. Since the levels of 4E-BP1 are relatively low in untreated pancreatic cancer cells these results suggest that combined therapy with gemcitabine and TRAIL could improve the responsiveness of tumours to treatment by elevating the expression of 4E-BP1

    ESPEN Guideline: Clinical Nutrition in inflammatory bowel disease

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    Introduction: The ESPEN guideline presents a multidisciplinary focus on clinical nutrition in inflammatory bowel disease (IBD). Methodology: The guideline is based on extensive systematic review of the literature, but relies on expert opinion when objective data were lacking or inconclusive. The conclusions and 64 recommendations have been subject to full peer review and a Delphi process in which uniformly positive responses (agree or strongly agree) were required. Results: IBD is increasingly common and potential dietary factors in its aetiology are briefly reviewed. Malnutrition is highly prevalent in IBD – especially in Crohn's disease. Increased energy and protein requirements are observed in some patients. The management of malnu-trition in IBD is considered within the general context of support for malnourished patients. Treatment of iron deficiency (parenterally if necessary) is strongly recommended. Routine provision of a special diet in IBD is not however supported. Parenteral nutrition is indicated only when enteral nutrition has failed or is impossible. The recommended perioperative man-agement of patients with IBD undergoing surgery accords with general ESPEN guidance for patients having abdominal surgery. Probiotics may be helpful in UC but not Crohn's disease. Primary therapy using nutrition to treat IBD is not supported in ulcerative colitis, but is mod-erately well supported in Crohn's disease, especially in children where the adverse conse-quences of steroid therapy are proportionally greater. However, exclusion diets are generally not recommended and there is little evidence to support any particular formula feed when nutritional regimens are constructed. Conclusions: Available objective data to guide nutritional support and primary nutritional therapy in IBD are presented as 64 recommendations, of which 9 are very strong recom-mendations (grade A), 22 are strong recommendations (grade B) and 12 are based only on sparse evidence (grade 0); 21 recommendations are good practice points (GPP)

    Human Milk Banking-Facts and Issues to Resolve

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    The number of human milk banks is increasing worldwide. Although the beneficial effects of feeding premature infants with their mother’s milk are well documented, less is known about the effects of feeding these infants with pasteurized donor milk. We propose a randomized trial comparing the effects of a 100% human milk-based diet (human milk supplemented with a human milk-derived fortifier) and a diet (partially) based on bovine milk. In theory, human milk has a beneficial effect on various aspects of human physiology, most of which become apparent after infancy. We therefore propose an extensive follow-up program that takes this aspect into consideration. Other issues concerning the practice of human milk banks need to be addressed as well as optimization of the feeding strategies for preterm infants

    Rapid Enzymatic Response to Compensate UV Radiation in Copepods

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    Ultraviolet radiation (UVR) causes physical damage to DNA, carboxylation of proteins and peroxidation of lipids in copepod crustaceans, ubiquitous and abundant secondary producers in most aquatic ecosystems. Copepod adaptations for long duration exposures include changes in behaviour, changes in pigmentation and ultimately changes in morphology. Adaptations to short-term exposures are little studied. Here we show that short-duration exposure to UVR causes the freshwater calanoid copepod, Eudiaptomus gracilis, to rapidly activate production of enzymes that prevent widespread collateral peroxidation (glutathione S-transferase, GST), that regulate apoptosis cell death (Caspase-3, Casp-3), and that facilitate neurotransmissions (cholinesterase-ChE). None of these enzyme systems is alone sufficient, but they act in concert to reduce the stress level of the organism. The interplay among enzymatic responses provides useful information on how organisms respond to environmental stressors acting on short time scales

    Hard-Object Feeding in Sooty Mangabeys (Cercocebus atys) and Interpretation of Early Hominin Feeding Ecology

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    Morphology of the dentofacial complex of early hominins has figured prominently in the inference of their dietary adaptations. Recent theoretical analysis of craniofacial morphology of Australopithecus africanus proposes that skull form in this taxon represents adaptation to feeding on large, hard objects. A modern analog for this specific dietary specialization is provided by the West African sooty mangabey, Cercocebus atys. This species habitually feeds on the large, exceptionally hard nuts of Sacoglottis gabonensis, stereotypically crushing the seed casings using their premolars and molars. This type of behavior has been inferred for A. africanus based on mathematical stress analysis and aspects of dental wear and morphology. While postcanine megadontia, premolar enlargement and thick molar enamel characterize both A. africanus and C. atys, these features are not universally associated with durophagy among living anthropoids. Occlusal microwear analysis reveals complex microwear textures in C. atys unlike those observed in A. africanus, but more closely resembling textures observed in Paranthropus robustus. Since sooty mangabeys process hard objects in a manner similar to that proposed for A. africanus, yet do so without the craniofacial buttressing characteristic of this hominin, it follows that derived features of the australopith skull are sufficient but not necessary for the consumption of large, hard objects. The adaptive significance of australopith craniofacial morphology may instead be related to the toughness, rather than the hardness, of ingested foods

    Conservation status of a recently described endemic land snail, Candidula coudensis, from the Iberian Peninsula

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    Research ArticleWe assessed the distribution, population size and conservation status of Candidula coudensis, a recently described endemic land snail from Portugal. From March 2013 to April 2014, surveys were carried out in the region where the species was described. We found an extent of occurrence larger than originally described, but still quite small (13.5 km2). The species was found mainly in olive groves, although it occurred in a variety of other habitats with limestone soils, including grasslands, scrublands and stone walls. Minimum population estimate ranged from 110,000–311,000 individuals. The main identified potential threats to the species include wildfires, pesticides and quarrying. Following the application of IUCN criteria, we advise a conservation status of either “Least Concern” or “Near-threatened” under criterion D (restricted population)info:eu-repo/semantics/publishedVersio

    Corticosteroid therapy for sepsis: a clinical practice guideline

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    What you need to knowSepsis is a syndrome of life threatening infection with organ dysfunction, and most guidelines do not advise use of corticosteroids to treat it in the absence of refractory shockTwo new trials of corticosteroid treatment for sepsis came to differing conclusionsCorticosteroids may reduce the risk of death by a small amount and increase neuromuscular weakness by a small amount, but the evidence is not definitive This guideline makes a weak recommendation for corticosteroids in patients with sepsis; both steroids and no steroids are reasonable management optionsFully informed patients who value avoiding death over quality of life and function would likely choose corticosteroidsDo corticosteroids reduce death or improve recovery in people with sepsis or septic shock? Our panel make a weak recommendation to give corticosteroids to people with all types and severity of sepsis, based on new evidence. Because we are not certain that they are beneficial, it is also reasonable not to prescribe them. Patients’ values and preferences may guide this decision-making process.This rapid recommendation was triggered by two trials, with differing conclusions whose results might change practice:ADRENAL (3658 patients who had septic shock) found no statistically significant difference in 90 day mortality between the hydrocortisone and placebo groups.1APROCCHSS (1241 patients who had septic shock) found that hydrocortisone plus fludrocortisone reduced 90 day mortality.2The trials are incorporated into a linked systematic review comparing corticosteroids with placebo.3 This BMJ Rapid Recommendation promptly and transparently translates this evidence using GRADE methodology for trustworthy guidelines. Sepsis is a life threatening organ dysfunction from infection. Currently most guidelines advise against giving corticosteroids in sepsis in the absence of refractory shock, but these guidelines have not taken into account the new evidence. We do not anticipate that new clinical trials will substantively alter the evidence
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