Surface layer stiffness effects on fracture of polymer multilayers: a linear elastic model

Accepted versio

Effect of axial surface scores on rapid crack propagation in polyethylene pipe

Accepted versio

Specimen temperature conditioning and drift before an S4 pipe fracture test

Accepted versio

Specimen temperature conditioning and drift before an S4 pipe fracture test

Accepted versio

'Special K' and a loss of cell-to-cell adhesion in proximal tubule-derived epithelial cells: modulation of the adherens junction complex by ketamine

Ketamine, a mild hallucinogenic class C drug, is the fastest growing ‘party drug’ used by 16–24 year olds in the UK. As the recreational use of Ketamine increases we are beginning to see the signs of major renal and bladder complications. To date however, we know nothing of a role for Ketamine in modulating both structure and function of the human renal proximal tubule. In the current study we have used an established model cell line for human epithelial cells of the proximal tubule (HK2) to demonstrate that Ketamine evokes early changes in expression of proteins central to the adherens junction complex. Furthermore we use AFM single-cell force spectroscopy to assess if these changes functionally uncouple cells of the proximal tubule ahead of any overt loss in epithelial cell function. Our data suggests that Ketamine (24–48 hrs) produces gross changes in cell morphology and cytoskeletal architecture towards a fibrotic phenotype. These physical changes matched the concentration-dependent (0.1–1 mg/mL) cytotoxic effect of Ketamine and reflect a loss in expression of the key adherens junction proteins epithelial (E)- and neural (N)-cadherin and β-catenin. Down-regulation of protein expression does not involve the pro-fibrotic cytokine TGFβ, nor is it regulated by the usual increase in expression of Slug or Snail, the transcriptional regulators for E-cadherin. However, the loss in E-cadherin can be partially rescued pharmacologically by blocking p38 MAPK using SB203580. These data provide compelling evidence that Ketamine alters epithelial cell-to-cell adhesion and cell-coupling in the proximal kidney via a non-classical pro-fibrotic mechanism and the data provides the first indication that this illicit substance can have major implications on renal function. Understanding Ketamine-induced renal pathology may identify targets for future therapeutic intervention

Association between proton pump inhibitor therapy and clostridium difficile infection: a contemporary systematic review and meta-analysis.

Abstract Introduction Emerging epidemiological evidence suggests that proton pump inhibitor (PPI) acid-suppression therapy is associated with an increased risk of Clostridium difficile infection (CDI). Methods Ovid MEDLINE, EMBASE, ISI Web of Science, and Scopus were searched from 1990 to January 2012 for analytical studies that reported an adjusted effect estimate of the association between PPI use and CDI. We performed random-effect meta-analyses. We used the GRADE framework to interpret the findings. Results We identified 47 eligible citations (37 case-control and 14 cohort studies) with corresponding 51 effect estimates. The pooled OR was 1.65, 95% CI (1.47, 1.85), I2 = 89.9%, with evidence of publication bias suggested by a contour funnel plot. A novel regression based method was used to adjust for publication bias and resulted in an adjusted pooled OR of 1.51 (95% CI, 1.26–1.83). In a speculative analysis that assumes that this association is based on causality, and based on published baseline CDI incidence, the risk of CDI would be very low in the general population taking PPIs with an estimated NNH of 3925 at 1 year. Conclusions In this rigorously conducted systemic review and meta-analysis, we found very low quality evidence (GRADE class) for an association between PPI use and CDI that does not support a cause-effect relationship

Regular breakfast consumption and type 2 diabetes risk markers in 9- to 10-year-old children in the child heart and health study in England (CHASE): a cross-sectional analysis.

BACKGROUND: Regular breakfast consumption may protect against type 2 diabetes risk in adults but little is known about its influence on type 2 diabetes risk markers in children. We investigated the associations between breakfast consumption (frequency and content) and risk markers for type 2 diabetes (particularly insulin resistance and glycaemia) and cardiovascular disease in children. METHODS AND FINDINGS: We conducted a cross-sectional study of 4,116 UK primary school children aged 9-10 years. Participants provided information on breakfast frequency, had measurements of body composition, and gave fasting blood samples for measurements of blood lipids, insulin, glucose, and glycated haemoglobin (HbA1c). A subgroup of 2,004 children also completed a 24-hour dietary recall. Among 4,116 children studied, 3,056 (74%) ate breakfast daily, 450 (11%) most days, 372 (9%) some days, and 238 (6%) not usually. Graded associations between breakfast frequency and risk markers were observed; children who reported not usually having breakfast had higher fasting insulin (percent difference 26.4%, 95% CI 16.6%-37.0%), insulin resistance (percent difference 26.7%, 95% CI 17.0%-37.2%), HbA1c (percent difference 1.2%, 95% CI 0.4%-2.0%), glucose (percent difference 1.0%, 95% CI 0.0%-2.0%), and urate (percent difference 6%, 95% CI 3%-10%) than those who reported having breakfast daily; these differences were little affected by adjustment for adiposity, socioeconomic status, and physical activity levels. When the higher levels of triglyceride, systolic blood pressure, and C-reactive protein for those who usually did not eat breakfast relative to those who ate breakfast daily were adjusted for adiposity, the differences were no longer significant. Children eating a high fibre cereal breakfast had lower insulin resistance than those eating other breakfast types (p for heterogeneity <0.01). Differences in nutrient intakes between breakfast frequency groups did not account for the differences in type 2 diabetes markers. CONCLUSIONS: Children who ate breakfast daily, particularly a high fibre cereal breakfast, had a more favourable type 2 diabetes risk profile. Trials are needed to quantify the protective effect of breakfast on emerging type 2 diabetes risk. Please see later in the article for the Editors' Summary

Functions, organization and etiology. A reply to Artiga and Martinez

International audienceWe reply to Artiga and Martinez's claim according to which the organizational account of cross-generation functions implies a backward looking interpretation of etiology, just as standard etiological theories of function do. We argue that Artiga and Martinez's claim stems from a fundamental misunderstanding about the notion of " closure " , on which the organizational account relies. In particular, they incorrectly assume that the system, which is relevant for ascribing cross-generation organizational function, is the lineage. In contrast, we recall that organizational closure refers to a relational description of a network of mutual dependencies, abstracted from time, in which production relations are irrelevant. From an organizational perspective, ascribing a function to an entity means locating it in the abstract system that realizes closure. In particular, the position of each entity within the relational system conveys an etiological explanation of its existence, because of its dependence on the effects exerted by other entities subject to closure. Because of the abstract relational nature of closure, we maintain that the organizational account of functions does not endorse a backward looking interpretation of etiology. As a consequence, it does not fall prey of epiphenomenalism

Pathological vertebral fracture after stereotactic body radiation therapy for lung metastases. Case report and literature review.

<p>Abstract</p> <p>Background</p> <p>Stereotactic body radiation therapy (SBRT) is a radiation technique used in patients with oligometastatic lung disease. Lung and chest wall toxicities have been described in the patients but pathological vertebral fracture is an adverse effect no reported in patients treated with SBRT for lung metastases.</p> <p>Case presentation</p> <p>A 68-year-old woman with the diagnosis of a recurrence of a single lung metastatic nodule of urothelial carcinoma after third line of chemotherapy. The patient received a hypo-fractionated course of SBRT.A 3D-conformal multifield technique was used with six coplanar and one non-coplanar statics beams. A total dose of 48 Gy in three fractions over six days was prescribed to the 95% of the CTV. Ten months after the SBRT procedure, a CT scan showed complete response of the metastatic disease without signs of radiation pneumonitis. However, rib and vertebral bone toxicities were observed with the fracture-collapse of the 7^thand 8^thvertebral bodies and a fracture of the 7^thand 8^thleft ribs. We report a unique case of pathological vertebral fracture appearing ten months after SBRT for an asymptomatic growing lung metastases of urothelial carcinoma.</p> <p>Conclusion</p> <p>Though SBRT allows for minimization of normal tissue exposure to high radiation doses SBRT tolerance for vertebral bone tissue has been poorly evaluated in patients with lung tumors. Oncologists should be alert to the potential risk of fatal bone toxicity caused by this novel treatment. We recommend BMD testing in all woman over 65 years old with clinical risk factors that could contribute to low BMD. If low BMD is demonstrated, we should carefully restrict the maximum radiation dose in the vertebral body in order to avoid intermediate or low radiation dose to the whole vertebral body.</p

Validation of the SCID-hu Thy/Liv mouse model with four classes of licensed antiretrovirals.

BackgroundThe SCID-hu Thy/Liv mouse model of HIV-1 infection is a useful platform for the preclinical evaluation of antiviral efficacy in vivo. We performed this study to validate the model with representatives of all four classes of licensed antiretrovirals.Methodology/principal findingsEndpoint analyses for quantification of Thy/Liv implant viral load included ELISA for cell-associated p24, branched DNA assay for HIV-1 RNA, and detection of infected thymocytes by intracellular staining for Gag-p24. Antiviral protection from HIV-1-mediated thymocyte depletion was assessed by multicolor flow cytometric analysis of thymocyte subpopulations based on surface expression of CD3, CD4, and CD8. These mice can be productively infected with molecular clones of HIV-1 (e.g., the X4 clone NL4-3) as well as with primary R5 and R5X4 isolates. To determine whether results in this model are concordant with those found in humans, we performed direct comparisons of two drugs in the same class, each of which has known potency and dosing levels in humans. Here we show that second-generation antiretrovirals were, as expected, more potent than their first-generation predecessors: emtricitabine was more potent than lamivudine, efavirenz was more potent than nevirapine, and atazanavir was more potent than indinavir. After interspecies pharmacodynamic scaling, the dose ranges found to inhibit viral replication in the SCID-hu Thy/Liv mouse were similar to those used in humans. Moreover, HIV-1 replication in these mice was genetically stable; treatment of the mice with lamivudine did not result in the M184V substitution in reverse transcriptase, and the multidrug-resistant NY index case HIV-1 retained its drug-resistance substitutions.ConclusionGiven the fidelity of such comparisons, we conclude that this highly reproducible mouse model is likely to predict clinical antiviral efficacy in humans