Depigmentation of Hair in Mice due to Tumour-Promoters and Other Chemicals

Sixty-six compound including carcinogens, related compounds and non-carcinogens were dissolved in dimethyl sulphoxide or saline and injected intradermally into C57 Black male mice. Localised areas of depigmentation occurred with some chemicals . The effect was related to tumour-promotion with 56% of known tumour-promoters tested producing depigmentation compared with 24% of carcinogens and 17% of substances not known to be carcinogenic. Direct carcinogens ouch as alkylating agents which have both initiating and. tumour-promoting activity produced depigmentaion. Indirect carcinogens such as the polycyclic aromatic hydrocarbons and aromatic amines which require metabolic activation were not active. Some compounds known to cause occupational leukoderma were active. Amongst the tumour-promoters, tetradecanoyl phorbol acetate (TBA). carbon dioxide snow and croton oil produced the most prominent depigmentation. The dose producing the effect in half the injected sites (i.e. ED50) was 0 .018 μg for TPA, 0.18 μg for nitrogen mustard and 101 μg for chloroform. Other tumour-promoters causing slight or moderate depigmentation included Tween 20, saccharin and dodecane. The promoters anthralin and phenobarbitone did not produce depigmentation when injected in tolerated doses. Histological examination and electron microscopy of depigmented areas showed loss of pigment in affected hair and a decrease in melanocytes at the hair bulbs. the latent period for depigmentation was usually between three to six weeks, but ground Crocidolite fibres produced depigmentation after sixteen weeks. Other forms of asbestos fibres caused no depigmentation. The depigmentation of hair might be developed as a short-term screening test for tumour-promotio

Immersive virtual reality enables technical skill acquisition for scrub nurses in complex revision total knee arthroplasty.

INTRODUCTION: Immersive Virtual Reality (iVR) is a novel technology which can enhance surgical training in a virtual environment without supervision. However, it is untested for the training to select, assemble and deliver instrumentation in orthopaedic surgery-typically performed by scrub nurses. This study investigates the impact of an iVR curriculum on this facet of the technically demanding revision total knee arthroplasty. MATERIALS AND METHODS: Ten scrub nurses completed training in four iVR sessions over a 4-week period. Initially, nurses completed a baseline real-world assessment, performing their role with real equipment in a simulated operation assessment. Each subsequent iVR session involved a guided mode, where the software taught participants the procedural choreography and assembly of instrumentation in a simulated operating room. In the latter three sessions, nurses also undertook an assessment in iVR. Outcome measures were related to procedural sequence, duration of surgery and efficiency of movement. Transfer of skills from iVR to the real world was assessed in a post-training simulated operation assessment. A pre- and post-training questionnaire assessed the participants knowledge, confidence and anxiety. RESULTS: Operative time reduced by an average of 47% across the 3 unguided sessions (mean 55.5 ± 17.6 min to 29.3 ± 12.1 min, p > 0.001). Assistive prompts reduced by 75% (34.1 ± 16.8 to 8.6 ± 8.8, p < 0.001), dominant hand motion by 28% (881.3 ± 178.5 m to 643.3 ± 119.8 m, p < 0.001) and head motion by 36% (459.9 ± 99.7 m to 292.6 ± 85.3 m, p < 0.001). Real-world skill improved from 11% prior to iVR training to 84% correct post-training. Participants reported increased confidence and reduced anxiety in scrubbing for rTKA procedures (p < 0.001). CONCLUSIONS: For scrub nurses, unfamiliarity with complex surgical procedures or equipment is common. Immersive VR training improved their understanding, technical skills and efficiency. These iVR-learnt skills transferred into the real world

Scanning electron microscopy and energy-dispersive x-ray spectroscopy (SEM-EDX) confirms shooting of a hen harrier (Circus cyaneus)

The hen harrier (Circus cyaneus) remains severely restricted as a breeding species in England despite sufficient habitat for over 300 breeding pairs. Human persecution is the main limiting factor and in the UK, there have been 45 confirmed incidents of shooting of hen harriers since records began (Royal Society for the Protection of Birds unpublished data). The authors report the pathological examination of a hen harrier, the detection of suspected ballistic fragments by radiograph and explain how scanning electron microscopy and energy-dispersive x-ray spectroscopy (SEM-EDX) was used to confirm (i) the composition of one ballistic remnant and (ii) that the remnant had been projected into and had damaged the bone. The authors report the use of post-analysis software to discriminate apparent anomalies produced by the proprietary SEM-EDX software package and discuss broader uses of SEM-EDX for wildlife crime investigation

Thermodynamics of an ideal generalized gas:II Means of order α\alpha

The property that power means are monotonically increasing functions of their order is shown to be the basis of the second laws not only for processes involving heat conduction but also for processes involving deformations. In an $L$-potentail equilibration the final state will be one of maximum entropy, while in an entropy equilibrium the final state will be one of minimum $L$. A metric space is connected with the power means, and the distance between means of different order is related to the Carnot efficiency. In the ideal classical gas limit, the average change in the entropy is shown to be proportional to the difference between the Shannon and R\'enyi entropies for nonextensive systems that are multifractal in nature. The $L$-potential, like the internal energy, is a Schur convex function of the empirical temperature, which satisfies Jensen's inequality, and serves as a measure of the tendency to uniformity in processes involving pure thermal conduction.Comment: 8 page

Deep Learning versus Classical Regression for Brain Tumor Patient Survival Prediction

Deep learning for regression tasks on medical imaging data has shown promising results. However, compared to other approaches, their power is strongly linked to the dataset size. In this study, we evaluate 3D-convolutional neural networks (CNNs) and classical regression methods with hand-crafted features for survival time regression of patients with high grade brain tumors. The tested CNNs for regression showed promising but unstable results. The best performing deep learning approach reached an accuracy of 51.5% on held-out samples of the training set. All tested deep learning experiments were outperformed by a Support Vector Classifier (SVC) using 30 radiomic features. The investigated features included intensity, shape, location and deep features. The submitted method to the BraTS 2018 survival prediction challenge is an ensemble of SVCs, which reached a cross-validated accuracy of 72.2% on the BraTS 2018 training set, 57.1% on the validation set, and 42.9% on the testing set. The results suggest that more training data is necessary for a stable performance of a CNN model for direct regression from magnetic resonance images, and that non-imaging clinical patient information is crucial along with imaging information.Comment: Contribution to The International Multimodal Brain Tumor Segmentation (BraTS) Challenge 2018, survival prediction tas

Frequency of thrombocytopenia and heparin induced thrombocytopenia in patients receiving extracorporeal membrane oxygenation compared to cardiopulmonary bypass and the limited sensitivity of pre-test probability score

Objectives:To ascertain:i)the frequency of thrombocytopeniaand heparininducedthrombocytopenia (HIT), ii)positive predictive value (PPV) of the pre-test probability score (PTPS) in identifying HIT iii)clinical outcome of HITin adult patients receiving veno-venous (VV)-extracorporeal membraneoxygenation(ECMO)or veno-arterial (VA)-ECMO, comparedto cardiopulmonary bypass (CPB). Design: A single-centre, retrospective, observational cohort study from January 2016 to April 2018Setting: Tertiary referral centre for cardiac and respiratory failure Patients:Patients who received ECMOfor>48hrs or had CPB during specified period Interventions: None.Measurements and Main Results:Clinical and laboratory data were collected retrospectively. PTPS and HIT testing results were collected prospectively. Mean age (standard deviation) of the EMCO and CPB cohorts were 45.4 (±15.6) and 64.9 (±13), p< 0.00001.Median duration of CPB was 4.6 [2-16.5]hrs compared to 170.4[70-1008] hrson ECMO.Moderateand severethrombocytopenia were more common in ECMO compared to CPB throughout (p<0.0001).Thrombocytopenia increased in CPB patients on day2 but was 4normal in 83% compared to 42.3 % ofECMOpatients at day 10. Patients on ECMO also followed a similar pattern of platelet recoveryfollowing cessation of ECMO. The incidences of HIT in ECMO and CPB were 6.4% (19/298) and 0.6% (18/2998) respectivelyp<0.0001). There was no difference in prevalence of HIT in patients on VV-ECMO (9/156, 5.7%) vs VA-ECMO (11/142, 7.7%), p=0.81. The PPV of the PTPS in identifying HIT in patients post-CPB and on ECMO were 56.25% (18/32) and 25% (15/60) respectively. Mortalitywas not different with (6/19, 31.6%) or without (89/279, 32.2%) HIT in patients on ECMO,p=0.79. Conclusions Thrombocytopenia is already common at ECMO initiation. HIT is more frequent in both VV-and VA-ECMO compared to CPB. PPV of PTPSin identifying HIT was lower inECMO patients.HIT had no effect on mortality

Asia-Pacific consensus statement on the optimal use of high-sensitivity troponin assays in acute coronary syndromes diagnosis: focus on hs-TnI

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GIVE: portable genome browsers for personal websites.

Growing popularity and diversity of genomic data demand portable and versatile genome browsers. Here, we present an open source programming library called GIVE that facilitates the creation of personalized genome browsers without requiring a system administrator. By inserting HTML tags, one can add to a personal webpage interactive visualization of multiple types of genomics data, including genome annotation, "linear" quantitative data, and genome interaction data. GIVE includes a graphical interface called HUG (HTML Universal Generator) that automatically generates HTML code for displaying user chosen data, which can be copy-pasted into user's personal website or saved and shared with collaborators. GIVE is available at: https://www.givengine.org/

A field-theoretic approach to the Wiener Sausage

The Wiener Sausage, the volume traced out by a sphere attached to a Brownian particle, is a classical problem in statistics and mathematical physics. Initially motivated by a range of field-theoretic, technical questions, we present a single loop renormalised perturbation theory of a stochastic process closely related to the Wiener Sausage, which, however, proves to be exact for the exponents and some amplitudes. The field-theoretic approach is particularly elegant and very enjoyable to see at work on such a classic problem. While we recover a number of known, classical results, the field-theoretic techniques deployed provide a particularly versatile framework, which allows easy calculation with different boundary conditions even of higher momenta and more complicated correlation functions. At the same time, we provide a highly instructive, non-trivial example for some of the technical particularities of the field-theoretic description of stochastic processes, such as excluded volume, lack of translational invariance and immobile particles. The aim of the present work is not to improve upon the well-established results for the Wiener Sausage, but to provide a field-theoretic approach to it, in order to gain a better understanding of the field-theoretic obstacles to overcome.Comment: 45 pages, 3 Figures, Springer styl

Ultrastructural and functional fate of recycled vesicles in hippocampal synapses

Efficient recycling of synaptic vesicles is thought to be critical for sustained information transfer at central terminals. However, the specific contribution that retrieved vesicles make to future transmission events remains unclear. Here we exploit fluorescence and time-stamped electron microscopy to track the functional and positional fate of vesicles endocytosed after readily releasable pool (RRP) stimulation in rat hippocampal synapses. We show that most vesicles are recovered near the active zone but subsequently take up random positions in the cluster, without preferential bias for future use. These vesicles non-selectively queue, advancing towards the release site with further stimulation in an actin-dependent manner. Nonetheless, the small subset of vesicles retrieved recently in the stimulus train persist nearer the active zone and exhibit more privileged use in the next RRP. Our findings reveal heterogeneity in vesicle fate based on nanoscale position and timing rules, providing new insights into the origins of future pool constitution