The Min protein system creates a dynamic spatial pattern in Escherichia coli cells where the proteins MinD and MinE oscillate from pole to pole. MinD positions MinC, an inhibitor of FtsZ ring ...formation, contributing to the mid-cell localization of cell division. In this paper, Fourier analysis is used to decompose experimental and model MinD spatial distributions into time-dependent harmonic components. In both experiment and model, the second harmonic component is responsible for producing a mid-cell minimum in MinD concentration. The features of this harmonic are robust in both experiment and model. Fourier analysis reveals a close correspondence between the time-dependent behaviour of the harmonic components in the experimental data and model. Given this, each molecular species in the model was analysed individually. This analysis revealed that membrane-bound MinD dimer shows the mid-cell minimum with the highest contrast when averaged over time, carrying the strongest signal for positioning the cell division ring. This concurs with previous data showing that the MinD dimer binds to MinC inhibiting FtsZ ring formation. These results show that non-linear interactions of Min proteins are essential for producing the mid-cell positioning signal via the generation of second-order harmonic components in the time-dependent spatial protein distribution.
Extinct animal behavior has often been inferred from qualitative assessments of relative brain region size in fossil endocranial casts. For instance, flight capability in pterosaurs and early birds ...has been inferred from the relative size of the cerebellar flocculus, which in life protrudes from the lateral surface of the cerebellum. A primary role of the flocculus is to integrate sensory information about head rotation and translation to stabilize visual gaze via the vestibulo-occular reflex (VOR). Because gaze stabilization is a critical aspect of flight, some authors have suggested that the flocculus is enlarged in flying species. Whether this can be further extended to a floccular expansion in highly maneuverable flying species or floccular reduction in flightless species is unknown. Here, we used micro computed-tomography to reconstruct "virtual" endocranial casts of 60 extant bird species, to extract the same level of anatomical information offered by fossils. Volumes of the floccular fossa and entire brain cavity were measured and these values correlated with four indices of flying behavior. Although a weak positive relationship was found between floccular fossa size and brachial index, no significant relationship was found between floccular fossa size and any other flight mode classification. These findings could be the result of the bony endocranium inaccurately reflecting the size of the neural flocculus, but might also reflect the importance of the flocculus for all modes of locomotion in birds. We therefore conclude that the relative size of the flocculus of endocranial casts is an unreliable predictor of locomotor behavior in extinct birds, and probably also pterosaurs and non-avian dinosaurs.
Oral epithelial dysplasia is a histologically diagnosed potentially premalignant disorder of the oral mucosa, which carries a risk of malignant transformation to squamous cell carcinoma. The ...diagnosis and grading of oral epithelial dysplasia is challenging, with cases often referred to specialist oral and maxillofacial pathology centres for second opinion. Even still there is poor inter-examiner and intra-examiner agreement in a diagnosis. There are a total of 28 features of oral epithelial dysplasia listed in the 5th edition of World Health Organization classification of tumours of the head and neck. Each of these features is poorly defined and subjective in its interpretation. Moreover, how these features contribute to dysplasia grading and risk stratification is even less well defined. This article discusses each of the features of oral epithelial dysplasia with examples and provides an overview of the common mimics, including the normal histological features of the oral mucosa which may mimic atypia. This article also highlights the paucity of evidence defining these features while offering suggested definitions. Ideally, these definitions will be refined, and the most important features identified to simplify the diagnosis of oral epithelial dysplasia. Digital whole slide images of the figures in this paper can be found at: https://www.pathogenesis.co.uk/r/demystifying-dysplasia-histology-dataset.
The overall incidence of colorectal cancer is decreasing in many high-income countries, yet analyses in the USA and other high-income countries such as Australia, Canada, and Norway have suggested ...increasing incidences among adults younger than 50 years. We aimed to examine longitudinal and generational changes in the incidence of colon and rectal cancer in seven high-income countries.
We obtained data for the incidence of colon and rectal cancer from 21 population-based cancer registries in Australia, Canada, Denmark, Norway, New Zealand, Ireland, and the UK for the earliest available year until 2014. We used age-period-cohort modelling to assess trends in incidence by age group, period, and birth cohort. We stratified cases by tumour subsite according to the 10th edition of the International Classification of Diseases. Age-standardised incidences were calculated on the basis of the world standard population.
An overall decline or stabilisation in the incidence of colon and rectal cancer was noted in all studied countries. In the most recent 10-year period for which data were available, however, significant increases were noted in the incidence of colon cancer in people younger than 50 years in Denmark (by 3·1%), New Zealand (2·9%), Australia (2·9%), and the UK (1·8%). Significant increases in the incidence of rectal cancer were also noted in this age group in Canada (by 3·4%), Australia (2·6%), and the UK (1·4%). Contemporaneously, in people aged 50-74 years, the incidence of colon cancer decreased significantly in Australia (by 1·6%), Canada (1·9%), and New Zealand (3·4%) and of rectal cancer in Australia (2·4%), Canada (1·2%), and the UK (1·2%). Increases in the incidence of colorectal cancer in people younger than 50 years were mainly driven by increases in distal (left) tumours of the colon. In all countries, we noted non-linear cohort effects, which were more pronounced for rectal than for colon cancer.
We noted a substantial increase in the incidence of colorectal cancer in people younger than 50 years in some of the countries in this study. Future studies are needed to establish the root causes of this rising incidence to enable the development of potential preventive and early-detection strategies.
Canadian Partnership Against Cancer, Cancer Council Victoria, Cancer Institute New South Wales, Cancer Research UK, Danish Cancer Society, National Cancer Registry Ireland, the Cancer Society of New Zealand, NHS England, Norwegian Cancer Society, Public Health Agency Northern Ireland, Scottish Government, Western Australia Department of Health, and Wales Cancer Network.
The lungs have their own microbiota which seems to be altered in disease processes such as asthma. Viral infection accounts for many asthma exacerbations. Little is known about the lung virome, and ...the role that viruses play in non-exacerbating asthmatics. We aimed to assess if detection of virus in bronchoscopy samples of asthmatic patients in a non-exacerbating state influences their asthma control and modulates airway cytokine composition. Patients were recruited from a specialist asthma clinic and underwent bronchoscopy with standardised bronchoalveolar lavage (BAL). Viral analysis was performed; cell differential and cytokine levels were measured. Forty-six samples were obtained of which 10.8% demonstrated evidence of airway virus, and 91.3% of patients in the cohort were classed as severe asthmatics. Oral steroid use was significantly higher in severe asthmatic patients with virus detected, and the forced expiratory volume in one second tended to be lower in the virus-detected group. It was also found that BAL interleukin-13 and tumor necrosis factor-α levels were significantly higher in severe asthmatic patients with virus detected. Our results suggest that in severe asthmatics in a non-exacerbating state, the presence of virus resulted in overall poorer asthma control. The pattern of cytokine elevation seen in asthmatic patients with virus detected may provide insight to the pathophysiology involved.
Data from population-based cancer registries are often used to compare cancer survival between countries or regions. The ICBP SURVMARK-2 study is an international partnership aiming to quantify and ...explore the reasons behind survival differences across high-income countries. However, the magnitude and relevance of differences in cancer survival between countries have been questioned, as it is argued that observed survival variations may be explained, at least in part, by differences in cancer registration practice, completeness and the availability and quality of the respective data sources.
As part of the ICBP SURVMARK-2 study, we used a simulation approach to better understand how differences in completeness, the characteristics of those missed and inclusion of cases found from death certificates can impact on cancer survival estimates.
Bias in 1- and 5-year net survival estimates for 216 simulated scenarios is presented. Out of the investigated factors, the proportion of cases not registered through sources other than death certificates, had the largest impact on survival estimates.
Our results show that the differences in registration practice between participating countries could in our most extreme scenarios explain only a part of the largest observed differences in cancer survival.
Abstract Interactions between neurotransmitters and the immune system represent new prospects for understanding neuroinflammation and associated neurological disease. GABA is the chief inhibitory ...neurotransmitter but its actions on immune pathways in the brain are unclear. In the present study, we investigated GABAergic transport in conjunction with neuroinflammation in models of multiple sclerosis (MS). Protein and mRNA levels of γ-amino butyric acid transporter 2 (GAT-2) were examined in cerebral white matter from MS and control (Non-MS) patients, in cultured human macrophages, microglia and astrocytes, and in spinal cords from mice with and without experimental autoimmune encephalomyelitis (EAE) using western blotting, immunocytochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). GABA levels were measured by HPLC. The GAT-2′s expression was increased in MS patients’ ( n = 6) white matter, particularly in macrophage lineage cells, compared to Non-MS patients ( n = 6) ( p < 0.05). Interferon-γ (IFN-γ) stimulation of human macrophage lineage cells induced GAT -2 expression and reduced extracellular GABA levels ( p < 0.05) but soluble GABA treatment suppressed HLA-DRα , GAT -2 and XBP-1 /s expression in stimulated macrophage lineage cells ( p < 0.05). Similarly, the synthetic allopregnanolone analog, ganaxolone (GNX), repressed GAT-2, JAK-1 and STAT-1 expression in activated macrophage lineage cells ( p < 0.05). In vivo GNX treatment reduced Gat -2, Cd 3ε, Mhc II, and Xbp-1 /s expression in spinal cords following EAE induction ( p < 0.05), which was correlated with improved neurobehavioral outcomes and reduced neuroinflammation, demyelination and axonal injury. These findings highlight altered GABAergic transport through GAT-2 induction during neuroinflammation. GABA transport and neuroinflammation are closely coupled but regulated by GNX, pointing to GABAergic pathways as therapeutic targets in neuroinflammatory diseases.
Open data and digital morphology Davies, Thomas G.; Rahman, Imran A.; Lautenschlager, Stephan ...
Proceedings of the Royal Society. B, Biological sciences,
04/2017, Volume:
284, Issue:
1852
Journal Article
Peer reviewed
Open access
Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. ...However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility.
Oscillations of the Min protein system are involved in the correct midcell placement of the divisome during Escherichia coli cell division. Based on molecular interactions of the Min system, we ...formulated a mathematical model that reproduces Min patterning during cell growth and division. Specifically, the increase in the residence time of MinD attached to the membrane as its own concentration increases, is accounted for by dimerisation of membrane-bound MinD and its interaction with MinE. Simulation of this system generates unparalleled correlation between the waveshape of experimental and theoretical MinD distributions, suggesting that the dominant interactions of the physical system have been successfully incorporated into the model. For cells where MinD is fully-labelled with GFP, the model reproduces the stationary localization of MinD-GFP for short cells, followed by oscillations from pole to pole in larger cells, and the transition to the symmetric distribution during cell filamentation. Cells containing a secondary, GFP-labelled MinD display a contrasting pattern. The model is able to account for these differences, including temporary midcell localization just prior to division, by increasing the rate constant controlling MinD ATPase and heterotetramer dissociation. For both experimental conditions, the model can explain how cell division results in an equal distribution of MinD and MinE in the two daughter cells, and accounts for the temperature dependence of the period of Min oscillations. Thus, we show that while other interactions may be present, they are not needed to reproduce the main characteristics of the Min system in vivo.
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