Biologic Treatment Registry Across Canada (BioTRAC): a multicentre, prospective, observational study of patients treated with infliximab for ankylosing spondylitis

Objectives

To describe the profile of patients with ankylosing spondylitis (AS) treated with infliximab in Canadian routine care and to assess the effectiveness and safety of infliximab in real world.

Setting

46 primary care rheumatology practices across Canada.

Participants

303 biological-naïve patients with AS or patients previously treated with a biological for <6 months and who were eligible for infliximab treatment as per routine care within the Biologic Treatment Registry Across Canada (BioTRAC).

Intervention

Not applicable (non-interventional study).

Primary and secondary outcomes

Effectiveness was assessed with changes in disease parameters (AS Disease Activity Score (ASDAS), Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), Health Assessment Questionnaire Disease Index (HAQ-DI), physician global assessment of disease activity (MDGA), patient global disease activity (PtGA), back pain, C-reactive protein, erythrocyte sedimentation rate (ESR), morning stiffness). Safety was assessed with the incidence of adverse events (AEs).

Results

Of the 303 patients included, 44.6% were enrolled in 2005–2007 and 55.4% in 2008–2013. Patients enrolled in 2005–2007 had significantly higher MDGA and ESR at baseline while all other disease parameters examined were numerically higher with the exception of PtGA. Treatment with infliximab significantly (p<0.001) improved all disease parameters over time in both groups. At 6 months, 56% and 31% of patients achieved clinically important (change≥1.1) and major (change≥2.0) improvement in ASDAS, respectively; at 48 months, these proportions increased to 75% and 50%, respectively. Among patients unemployed due to disability at baseline, 12.1% returned to work (mean Kaplan-Meier (KM)-based time=38.8 months). The estimated retention rate at 12 and 24 months was 78.3% and 60.1%, respectively. The profile and incidence of AEs were comparable to data previously reported for tumour necrosis factor-α inhibitors.

Conclusions

Characteristics of patients with AS at infliximab initiation changed over time towards lower disease activity and shorter disease duration. Infliximab treatment significantly reduced disease activity independent of treatment initiation year, although patients enrolled in recent years achieved lower disease activity over 48 months.

Trial registration number

NCT00741793.

from #Medicine via ola Kala on Inoreader http://ift.tt/1qq0u4l
via IFTTT

Effect of vitamin D supplementation on inflammation: protocol for a systematic review

Introduction

The extraskeletal role of vitamin D is being increasingly recognised. This has important clinical implications, as vitamin D deficiency has reached epidemic proportions worldwide. Vitamin D has proposed anti-inflammatory properties, yet the role of vitamin D supplementation in reducing inflammation remains largely unknown. The purpose of this review is to investigate the impact of vitamin D supplementation on inflammation, and to identify relevant knowledge gaps in the field.

Methods and analysis

Medline, CINAHL, EMBASE and All EBM will be systematically searched for randomised controlled trials (RCTs) and systematic reviews of RCTs, comparing vitamin D supplementation with placebo, usual care or other pharmacological or non-pharmacological interventions. One reviewer will assess articles for eligibility according to prespecified selection criteria, after which 2 independent reviewers will perform data extraction and quality appraisal. Meta-analyses will be conducted where appropriate.

Ethics and dissemination

Formal ethical approval is not required as no primary data is collected. This systematic review will identify potential clinical implications of vitamin D deficiency and supplementation, and will be disseminated through a peer-reviewed publication and at conference meetings, to inform future research on the efficacy of vitamin D supplementation for inflammation and inflammatory diseases.

PROSPERO registration number

CRD42016037104.

from #Medicine via ola Kala on Inoreader http://ift.tt/1oAE4eW
via IFTTT

Community social capital and tooth loss in Japanese older people: a longitudinal cohort study

Objective

To date, no study has prospectively examined the association between social capital (SC) in the community and oral health. The aim of this longitudinal cohort study was to examine the association between both community-level and individual-level SC and tooth loss in older Japanese people.

Design

Prospective cohort study

Setting

We utilised data from the Japan Gerontological Evaluation Study (JAGES) performed in 2010 and 2013 and conducted in 525 districts.

Participants

The target population was restricted to non-institutionalised people aged 65 years or older. Participants included 51 280 people who responded to two surveys and who had teeth at baseline.

Primary outcome measure

The primary outcome measure was loss of remaining teeth, measured by the downward change of any category of remaining teeth, between baseline and follow-up.

Results

The mean age of the participants was 72.5 years (SD=5.4). During the study period, 8.2% (n=4180) lost one or more of their remaining teeth. Among three community-level SC variables obtained from factor analysis, an indicator of civic participation significantly reduced the risk of tooth loss (OR 0.93; 95% CI 0.88 to 0.99). The individual-level SC variables 'hobby activity participation' and 'sports group participation' were also associated with a reduced risk of tooth loss (OR 0.88; 95% CI 0.81 to 0.95 and OR 0.90; 95% CI 0.82 to 0.99, respectively).

Conclusions

Living in a community with rich SC and individuals with good SC is associated with lower incidence of tooth loss among older Japanese people.

from #Medicine via ola Kala on Inoreader http://ift.tt/1qq0tNT
via IFTTT

Treatment outcomes of oral sitafloxacin in acute complicated urinary tract infection and pyelonephritis

Data on the success rate of sitafloxacin treatment in acute complicated urinary tract infection and pyelonephritis are limited.

from #Medicine via ola Kala on Inoreader http://ift.tt/1YeiCZo
via IFTTT

Fluorescence Detection of H5N1 Virus Gene Sequences Based on Optical Tweezers with Two-Photon Excitation Using a Single Near Infrared Nanosecond Pulse Laser

Analytical Chemistry

DOI: 10.1021/acs.analchem.6b00065

from #Medicine via ola Kala on Inoreader http://ift.tt/1Wb1RQa
via IFTTT

Combined Electron Paramagnetic Resonance and Atomic Absorption Spectroscopy/Inductively Coupled Plasma Analysis As Diagnostics for Soluble Manganese Species from Mn-Based Positive Electrode Materials in Li-ion Cells

Analytical Chemistry

DOI: 10.1021/acs.analchem.6b00204

from #Medicine via ola Kala on Inoreader http://ift.tt/1PSLP5W
via IFTTT

Fatty acid supplements for improving dry eye symptoms in patients with glaucoma

Tellez-Vazquez J

from #Medicine via ola Kala on Inoreader http://ift.tt/1Mcek3Z
via IFTTT

Seasonal changes in microbial community composition in river water studied using 454-pyrosequencing

The aims of this study were to determine the microbial community in five rivers in the proximity of a city in the Czech Republic using 454-pyrosequencing, as well as to assess seasonal variability over the cou...

from #Medicine via ola Kala on Inoreader http://ift.tt/1S9YT8z
via IFTTT

The impact of long term institutional collaboration in surgical training on trauma care in Malawi

Attempts to address the huge, and unmet, need for surgical services in Africa by training surgical specialists in well established training programmes in high-income countries have resulted in brain drain, as ...

from #Medicine via ola Kala on Inoreader http://ift.tt/1McaV56
via IFTTT

Mathematical modelling of bacterial resistance to multiple antibiotics and immune system response

Resistance of developed bacteria to antibiotic treatment is a very important issue, because introduction of any new antibiotic is after a little while followed by the formation of resistant bacterial isolates ...

from #Medicine via ola Kala on Inoreader http://ift.tt/1Sz6EFG
via IFTTT

A retrospective analysis of eye conditions among children attending St. John Eye Hospital, Hebron, Palestine

Eye diseases are important causes of medical consultations, with the spectrum varying in different regions. This hospital-based descriptive study aimed to determine the profile of childhood eye conditions at S...

from #Medicine via ola Kala on Inoreader http://ift.tt/1RMDWkS
via IFTTT

Correction to Determination of DNA and RNA Methylation in Circulating Tumor Cells by Mass Spectrometry

Analytical Chemistry

DOI: 10.1021/acs.analchem.6b01215

from #Medicine via ola Kala on Inoreader http://ift.tt/1XfKQTq
via IFTTT

Microchannel Voltammetry in the Presence of Large External Voltages and Electric Fields

Analytical Chemistry

DOI: 10.1021/acs.analchem.6b00399

from #Medicine via ola Kala on Inoreader http://ift.tt/1PSAva3
via IFTTT

Optical Monitoring of Living Nerve Terminal Labeling in Hair Follicle Lanceolate Endings of the Ex Vivo Mouse Ear Skin

Here we describe a novel preparation for imaging live lanceolate sensory terminals of palisade endings that innervate mouse ear skin hair follicles during staining and destaining with styryl pyridinium dyes.

from #Medicine via ola Kala on Inoreader http://ift.tt/1qplXdG
via IFTTT

Belly Breathing to Reduce Stress

Tags: 

Fitness

Mercy Clinic

Mercy Top News

Files: 

Belly Breathing Front View

Belly Breathing Side View

Media Contact: 

Bethany Pope

Place one hand on your chest and the other
on your stomach to feel the air moving down into your
belly pushing that hand upward.

Contributed by Dr. Paul Angleton, a  Mercy Clinic primary care physician.

Patients are often surprised when I tell them I'm going to teach them how to breathe. I get a lot of comments like, "Doc, I wouldn't have made it to 50 if I couldn't breathe." Most of them end up a little surprised when they learn they've been doing it wrong all those years.

There's some debate in modern medicine about whether stress itself is a killer, or whether it's more of how we respond to, or even embrace, stress. It's clear, though, that a negative response to stress can wreak havoc on our physical and mental health.

Increased levels of stress hormones like cortisol and adrenaline can lead to elevations in blood pressure, obesity, fatigue, anxiety, insomnia, irritability and muscle tightness. Even if we aren't showing any outward signs, we can all benefit from breaking this cycle. Relaxation, meditation, massage, regular exercise and prayer can all be helpful, but so can breathing if you do it right.

Diaphragmatic breathing is also known as belly breathing. A lot of people think the concept is just too simple to have any real benefit. However, the science is clear with several studies showing reductions in stress hormones and improved immune function along with a reduction in muscle tension, reduction in blood pressure, better blood flow to muscles and improved concentration. I usually recommend targeting 10 minutes in the morning and 10 minutes in the evening. You can get some benefit in as little as a minute of intentional, focused diaphragmatic breathing.

So how is this type of breathing different? When most people take a deep breath, we will feel our shoulders rise and fall, but if we are breathing correctly, our shoulders should remain still and the belly should extend outward with the inhale and back in as we breathe out. We tend to hold our bellies in tight when we sit or stand (either for good posture or to make ourselves look skinnier) so the easiest way to learn this skill is lying down. Get comfortable, some may need to bend their knees to get the belly to feel soft even when lying down. Place one hand on your chest and one on your stomach. Breathe though your nose and as you inhale, feel the air moving down into your belly pushing that hand upward. The hand on the chest should move little to none until the very end of the breath. When you exhale, use your abdominal muscles to force all of the air out of your lungs. At first you may need to even push with your hand a little to force the air out. Then, let the next breath in, picturing the air moving into and raising the hand on your belly.

Now that you know how to breathe properly, it's important to practice it daily –  even if you don't feel stressed. That way, you can master this skill and use it for the more difficult days.

 

Show EMS Sitewide: 

Yes!

from #Medicine via ola Kala on Inoreader http://ift.tt/1RD0ibU
via IFTTT

Neuromuscular Impairments Contributing to Persistently Poor and Declining Lower-Extremity Mobility among Older Adults: New Findings Informing Geriatric Rehabilitation

Publication date: Available online 4 April 2016
Source:Archives of Physical Medicine and Rehabilitation
Author(s): Rachel E. Ward, Marla K. Beauchamp, Nancy K. Latham, Suzanne G. Leveille, Sanja Percac-Lima, Laura Kurlinski, Pengsheng Ni, Richard Goldstein, Alan M. Jette, Jonathan F. Bean
ObjectiveTo identify neuromuscular impairments most predictive of unfavorable mobility outcomes in late-life.DesignLongitudinal cohort study.SettingResearch clinic.ParticipantsCommunity-dwelling primary care patients aged ≥65 years (N=391) with self-reported mobility modifications, randomly selected from a research registry.Intervention(s)Not applicable.Main Outcome Measure(s)Categories of decline in and persistently poor mobility across baseline, 1 and 2 years of follow-up in the Lower-Extremity Function scales of the Late-Life Function and Disability Instrument. "The following categories of impairment were assessed as potential predictors of mobility change: strength (leg strength), speed of movement (leg velocity, reaction time, rapid leg coordination), ROM (knee flexion/knee extension/ankle ROM), asymmetry (asymmetry of leg strength and knee flexion/extension ROM measures), and trunk stability (trunk extensor endurance, kyphosis)."ResultsThe largest effect sizes were found for baseline weaker leg strength (OR [95% CI]: 3.45 [1.72-6.95]), trunk extensor endurance (2.98 [1.56-5.70]), and slower leg velocity (2.35 [1.21-4.58]) predicting a greater likelihood of persistently poor function over 2 years. Baseline weaker leg strength, trunk extensor endurance, and restricted knee flexion motion also predicted a greater likelihood of decline in function (1.72 [1.10-2.70], 1.83 [1.56-5.70], 2.03 [1.24-3.35]).ConclusionOlder adults exhibiting poor mobility may be prime candidates for rehabilitation focused on improving these impairments. These findings lay the ground work for developing interventions aimed at optimizing rehabilitative care and disability prevention and highlight the importance of both well-recognized (leg strength) and novel impairments (leg velocity, trunk extensor muscle endurance).



from #Medicine via ola Kala on Inoreader http://ift.tt/23eOrVf
via IFTTT

Episode-based Payment for the Medicare Outpatient Therapy Benefit

Publication date: Available online 5 April 2016
Source:Archives of Physical Medicine and Rehabilitation
Author(s): Peter Amico, Gregory C. Pope, Ann Meadow, Pamela West
ObjectiveTo conduct an analysis of Medicare outpatient therapy episodes of care and associated payment implications.DesignRetrospective observational design using Medicare claims data. To descriptively analyze the composition of outpatient therapy episodes, we explore both variable and fixed length episodes. The variable-length episode definition organizes services into episodes based on the time pattern of therapy service utilization, using 60-day clean periods. We also examine fixed length episodes, beginning with the first therapy utilization in CY 2010 and extending 30, 60 and 90 days.SettingThe study is focused on community dwelling users of outpatient therapy.ParticipantsThe sample includes all Medicare patients who used outpatient therapy beginning at any point in 2010.InterventionsNot applicableMain OutcomeMeasures Mean episode payments and episode lengths in calendar days.ResultsVariable length outpatient therapy episodes have a mean payment of $881. On average, outpatient therapy episodes last 43 calendar days. Mean therapy duration for the 30, 60 and 90 day fixed-length episode is 20, 31 and 38 calendar days. The 30, 60 and 90 day fixed length initial episodes account for 40, 55 and 63 percent of total Medicare payments. Simulations of episode based payment illustrate the difficulty of avoiding a large number of substantial underpayments, due to the right-skewed distribution of total actual payments.ConclusionsA strength of episode payment is reducing cost and potentially wasteful variation within episodes. Given the substantial variation in therapy episode expenditures, absent improvements in available data and in predictive information, pure lump sum episode payment would result in substantial revenue changes for many episodes. Additional data is needed to better explain the wide variation in episode expenditures.



from #Medicine via ola Kala on Inoreader http://ift.tt/239p2zN
via IFTTT

The effects of HIV self-testing on the uptake of HIV testing and linkage to antiretroviral treatment among adults in Africa: a systematic review protocol

HIV is still a global public health problem. More than 75 % of HIV-infected people are in Africa, and most of them are unaware of their HIV status, which is a barrier to accessing antiretroviral treatment. Our...

from #Medicine via ola Kala on Inoreader http://ift.tt/23eJDPU
via IFTTT

Resective surgery for focal cortical dysplasia in children: a comparative analysis of the utility of intraoperative magnetic resonance imaging (iMRI)

Abstract

Purpose

Seizure freedom following resection of focal cortical dysplasia (FCD) correlates with complete resection of the dysplastic cortical tissue. However, difficulty with intraoperative identification of the lesion may limit the ability to achieve the surgical objective of complete extirpation of these lesions. Intraoperative magnetic resonance imaging (iMRI) may aid in FCD resections. The objective of this study is to compare rates of postoperative seizure freedom, completeness of resection, and need for reoperation in patients undergoing iMRI-assisted FCD resection versus conventional surgical techniques.

Methods

We retrospectively reviewed the medical records of pediatric subjects who underwent surgical resection of FCD at Children's National Medical Center between March 2005 and April 2015.

Results

At the time of the last postoperative follow-up, 11 of the 12 patients (92 %) in the iMRI resection group were seizure free (Engel Class I), compared to 14 of the 42 patients (33 %) in the control resection group (p = 0.0005). All 12 of the iMRI patients (100 %) achieved complete resection, compared to 24 of 42 patients (57 %) in the control group (p = 0.01). One (8 %) patient from the iMRI-assisted resection group has required reoperation, compared to 17 (40 %) patients in the control resection group.

Conclusion

Our results suggest that the utilization of iMRI during surgery for resection of FCD results in improved postoperative seizure freedom, completeness of lesion resection, and reduction in the need for reoperation.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RMjxfA
via IFTTT

Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices

Optogenetic approaches are widely used to manipulate neural activity and assess the consequences for brain function. Here, a technique is outlined that upon in vivo expression of the optical activator Channelrhodopsin, allows for ex vivo analysis of synaptic properties of specific long range and local neural connections in fear-related circuits.

from #Medicine via ola Kala on Inoreader http://ift.tt/1MQV9wy
via IFTTT

Experimental Strategies to Bridge Large Tissue Gaps in the Injured Spinal Cord after Acute and Chronic Lesion

Severe spinal cord injuries often result in tissue defects. Two possibilities are described to successfully bridge such gaps to promote tissue adaptation, regenerative responses and functional improvement in rats via implantation of a mechanical microconnector system after acute injury and five weeks after complete spinal cord transection.

from #Medicine via ola Kala on Inoreader http://ift.tt/1MQV9g2
via IFTTT

ELEVATED CORTISOL IN HEALTHY FEMALE ADOLESCENT OFFSPRING OF MOTHERS WITH POSTTRAUMATIC STRESS DISORDER

Publication date: Available online 4 April 2016
Source:Journal of Anxiety Disorders
Author(s): Keke Liu, Camilo J. Ruggero, Brandon Goldstein, Daniel N. Klein, Greg Perlman, Joan Broderick, Roman Kotov
Offspring with maternal PTSD are at increased risk of developing PTSD themselves. Alterations in the hypothalamus-pituitary-adrenal (HPA) axis may play a role and have been noted in offspring, although evidence is mostly from adult offspring with PTSD symptoms themselves. The present study of adolescent girls (N=472) and their mothers (n=18 with lifetime PTSD versus n=454 with no PTSD) sought to determine whether healthy, non-affected offspring of mothers with PTSD would exhibit altered HPA axis function. Saliva samples were collected from the adolescent girls at waking, 30minutes after waking, and 8 pm on 3 consecutive days. Offspring whose mothers were diagnosed with PTSD demonstrated higher cortisol awakening response (CAR; Cohen's d=.58) and greater total cortisol output (Cohen's d=.62). In this preliminary study, higher cortisol levels during adolescence among offspring of mothers with PTSD may index a vulnerability in these at-risk youth.



from #Medicine via ola Kala on Inoreader http://ift.tt/1MQV8Zy
via IFTTT

Recombinant Human Plasminogen Activator Inhibitor-1 Accelerates Odontoblastic Differentiation of Human Stem Cells from Apical Papilla

Tissue Engineering Part A , Vol. 0, No. 0.


from #Medicine via ola Kala on Inoreader http://ift.tt/1Ye08Io
via IFTTT

Extracorporeal shockwave therapy promotes chondrogenesis in cartilage tissue engineering: A hypothesis based on previous evidence

Publication date: Available online 5 April 2016
Source:Medical Hypotheses
Author(s): Qiaodan Ji, Chengqi He
The dearth of intrinsic regenerative capacity of articular cartilage makes it a challenge to deal with the cartilage defects. Among all the recommended clinical options, cartilage tissue engineering (CTE) which is highlighted of dominant features and less drawbacks for functional cartilage restoration, has been emphasized recently. Shock waves, a mode of therapeutic mechanical forces, utilized in extracorporeal shockwave therapy (ESWT), is hypothesized to enhance proliferation, chondrogenic differentiation, and cartilage extracellular matrix production of target cells seeded on bioactive scaffolds.The hypothesis is firstly based on cellular mechanotransduction by which cells convent the shockwave mechanical signals into biochemical responses via integrins, iron channels, cytoskeletal filaments, growth factor receptors and nuclei. Secondly, by modulating gene expression and up-regulating the release of various growth factors which are of vital importance in three-dimensional cartilage culture environment, ESWT holds a promising potential to favor the cell sources (e.g. chondrocytes and stem cells) to mimic the optimal functional cartilage.In all, on the basis of cellular mechanotransduction and previous evidence, the hypothesis is developed to support the beneficial effects of ESWT on chondrogenesis in CTE. If this hypothesis is confirmed, shockwaves may allow a better success in combination with other stimulating factors for cartilage repair. There is a paucity of studies investigating the assistant role of shockwave stimulation in CTE. Further research is required to elucidate the mechanisms, and explore effectiveness and appropriate protocols of this novel stimulative factor in cartilage tissue engineering.



from #Medicine via ola Kala on Inoreader http://ift.tt/1WarGzN
via IFTTT

Morphogenesis of the demyelinating lesions in Baló’s concentric sclerosis

Publication date: Available online 5 April 2016
Source:Medical Hypotheses
Author(s): Helmut Barz, Ulrich Barz, Almut Schreiber
In tissues with elastic properties, an edema causes a raised tissue pressure and therefore a diminished blood flow. The authors assume that an increased tissue pressure due to local and/or relapsing edema may be the cause for incomplete necrosis (e.g. demyelinated lesions) or seldom complete necrosis in the brain.Newly forming demyelinating lesions seldom show small tissue bands with normal appearing myelin sheaths in the immediate vicinity of precursor lesions (Baló type of MS). The small myelinated bands are the result of a "protected zone" on the edge of previous demyelinated lesions. The authors explain this protected zone with two arguments.Firstly, the resorptive granulation tissue of more or less older lesions is relatively rich in capillaries. These capillaries may act as an energy reservoir that can nourish not only the plaque, but also a narrow adjacent myelinated tissue band by diffusion, even if the capillary blood flow in this tissue band is limited due to the greater tissue pressure of a new developing lesion in the neighborhood.Secondly, another protective mechanism may act simultaneously: Older or more sclerosed lesions and small adherent bands of myelinated tissue with them may swell less in cases of an edema than in normal tissue. The hardening of the older lesions is caused by proliferated fiber-forming astrocytes in the sense of scarring. In an area with an increased tissue pressure, the capillaries are less compressed in a sclerosed lesion than in regions of normal grey and white matter. In addition, the adherent myelinated tissue band closest to the edge of a hardened plaque is better protected against swelling and compression than the further away tissue. Theoretically, this protection zone is comparable with protected blood vessels in the Haversian canals or the medullary spaces of bones.Both theses of protecting mechanisms at the edges of demyelinated lesions support the assumption of a hypoxic causation principle of demyelinating lesions in Baló's concentric sclerosis and multiple sclerosis.



from #Medicine via ola Kala on Inoreader http://ift.tt/1YdWZsd
via IFTTT

Correction for Gaiser et al., Cancer-associated epithelial cell adhesion molecule (EpCAM; CD326) enables epidermal Langerhans cell motility and migration in vivo [Correction]

IMMUNOLOGY Correction for "Cancer-associated epithelial cell adhesion molecule (EpCAM; CD326) enables epidermal Langerhans cell motility and migration in vivo," by Maria R. Gaiser, Tim Lämmermann, Xu Feng, Botond Z. Igyarto, Daniel H. Kaplan, Lino Tessarollo, Ronald N. Germain, and Mark C. Udey, which appeared in issue 15, April 10, 2012,...

from #Medicine via ola Kala on Inoreader http://ift.tt/1TA5VJf
via IFTTT

Sex differences in the brain do not {#x201C}add up{#x201D} [Biological Sciences]

As Marek Glezerman (1) rightly points out, there are differences between females and males in brain and behavior. Glezerman overlooks, however, the fact that such differences may be different and even opposite under different environmental conditions. That is, what is typical under some conditions in a brain composed of cells...

from #Medicine via ola Kala on Inoreader http://ift.tt/1UGmGU3
via IFTTT

Do brains belong to two distinct populations? [Biological Sciences]

We are glad that our paper (1) raised discussions on the relations between sex and the brain and on our new methodological approach. Clearly, sex affects the brain, as evidenced in differences between brains from females and brains from males in both macroscopic and microscopic features. However, the fact that...

from #Medicine via ola Kala on Inoreader http://ift.tt/1UGmJ2n
via IFTTT

Method fails to detect sex differences [Biological Sciences]

In their widely publicized paper, Joel et al. (1) make two empirical claims about sex differences in features of the human brain: (i) "…internal consistency [in individuals' sex-differentiated brain features] is rare" (p. 15472) and (ii) the amount of overlap in sex-differentiated features of male and female brains "undermines any...

from #Medicine via ola Kala on Inoreader http://ift.tt/1UGmG6s
via IFTTT

Predictable human brain mosaic [Biological Sciences]

In their PNAS article, Joel et al. (1) demonstrate extensive overlap between the distributions of females and males for many brain characteristics, measured across multiple neuroimaging modalities and datasets. They pose two requirements for categorizing brains into distinct male/female classes: (i) gender differences should appear as dimorphic form differences between...

from #Medicine via ola Kala on Inoreader http://ift.tt/23e0dPP
via IFTTT

Image segmentation with a novel regularized composite shape prior based on surrogate study

Purpose:

Incorporating training into image segmentation is a good approach to achieve additional robustness. This work aims to develop an effective strategy to utilize shape prior knowledge, so that the segmentation label evolution can be driven toward the desired global optimum.

Methods:

In the variational image segmentation framework, a regularization for the composite shape prior is designed to incorporate the geometric relevance of individual training data to the target, which is inferred by an image-based surrogate relevance metric. Specifically, this regularization is imposed on the linear weights of composite shapes and serves as a hyperprior. The overall problem is formulated in a unified optimization setting and a variational block-descent algorithm is derived.

Results:

The performance of the proposed scheme is assessed in both corpus callosum segmentation from an MR imageset and clavicle segmentation based on CTimages. The resulted shape composition provides a proper preference for the geometrically relevant training data. A paired Wilcoxon signed rank test demonstrates statistically significant improvement of image segmentation accuracy, when compared to multiatlas label fusion method and three other benchmark active contour schemes.

Conclusions:

This work has developed a novel composite shape prior regularization, which achieves superior segmentation performance than typical benchmark schemes.

from #Medicine via ola Kala on Inoreader http://ift.tt/1SNqeQZ
via IFTTT

Technical Note: Statistical dependences between channels in radiochromic film readings. Implications in multichannel dosimetry

Purpose:

This note studies the statistical relationships between color channels in radiochromic film readings with flatbed scanners. The same relationships are studied for noise. Finally, their implications for multichannel film dosimetry are discussed.

Methods:

Radiochromic films exposed to wedged fields of 6 MV energy were read in a flatbed scanner. The joint histograms of pairs of color channels were used to obtain the joint and conditional probability density functions between channels. Then, the conditional expectations and variances of one channel given another channel were obtained. Noise was extracted from film readings by means of a multiresolution analysis. Two different dose ranges were analyzed, the first one ranging from 112 to 473 cGy and the second one from 52 to 1290 cGy.

Results:

For the smallest dose range, the conditional expectations of one channel given another channel can be approximated by linear functions, while the conditional variances are fairly constant. The slopes of the linear relationships between channels can be used to simplify the expression that estimates the dose by means of the multichannel method. The slopes of the linear relationships between each channel and the red one can also be interpreted as weights in the final contribution to dose estimation. However, for the largest dose range, the conditional expectations of one channel given another channel are no longer linear functions. Finally, noises in different channels were found to correlate weakly.

Conclusions:

Signals present in different channels of radiochromic film readings show a strong statistical dependence. By contrast, noise correlates weakly between channels. For the smallest dose range analyzed, the linear behavior between the conditional expectation of one channel given another channel can be used to simplify calculations in multichannel film dosimetry.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RZG3Hw
via IFTTT

Potential benefits of dosimetric VMAT tracking verified with 3D film measurements

Purpose:

To evaluate three different plan adaptation strategies using 3D film-stack dosemeasurements of both focal boost and hypofractionated prostate VMAT treatments. The adaptation strategies (a couch shift, geometric tracking, and dosimetric tracking) were applied for three realistic intrafraction prostate motions.

Methods:

A focal boost (35 × 2.2 and 35 × 2.7 Gy) and a hypofractionated (5 × 7.25 Gy) prostate VMAT plan were created for a heterogeneous phantom that allows for internal prostate motion. For these plans geometric tracking and dosimetric tracking were evaluated by ionization chamber (IC) point dosemeasurements (zero-D) and measurements using a stack of EBT3 films (3D). The geometric tracking applied translations, rotations, and scaling of the MLC aperture in response to realistic prostate motions. The dosimetric tracking additionally corrected the monitor units to resolve variations due to difference in depth, tissue heterogeneity, and MLC-aperture. The tracking was based on the positions of four fiducial points only. The filmmeasurements were compared to the gold standard (i.e., IC measurements) and the planned dose distribution. Additionally, the 3D measurements were converted to dose volume histograms, tumor control probability, and normal tissue complication probability parameters (DVH/TCP/NTCP) as a direct estimate of clinical relevance of the proposed tracking.

Results:

Compared to the planned dose distribution, measurements without prostate motion and tracking showed already a reduced homogeneity of the dose distribution. Adding prostate motion further blurs the DVHs for all treatment approaches. The clinical practice (no tracking) delivered the dose distribution inside the PTV but off target (CTV), resulting in boost dose errors up to 10%. The geometric and dosimetric tracking corrected the dose distribution's position. Moreover, the dosimetric tracking could achieve the planned boost DVH, but not the DVH of the more homogeneously irradiated prostate. A drawback of both the geometric and dosimetric tracking was a reduced MLC blocking caused by the rotational component of the MLC aperture corrections. Because of the used CTV to PTV margins and the high doses in the considered fractionation schemes, the TCP differed less than 0.02 from the planned value for all targets and all correction methods. The rectal NTCP constraints, however, could not be realized using any of these methods.

Conclusions:

The geometric and dosimetric tracking use only a limited input, but they deposit the dose distribution with higher geometric accuracy than the clinical practice. The latter case has boost dose errors up to 10%. The increased accuracy has a modest impact [Δ(NT)CP dose levels used. To allow further margin reduction tracking methods are vital. The proposed methodology could further be improved by implementing a rotational correction using collimator rotations.

from #Medicine via ola Kala on Inoreader http://ift.tt/1SNqeAB
via IFTTT

Automatic coronary calcium scoring using noncontrast and contrast CT images

Purpose:

Calcium scoring is widely used to assess the risk of coronary heart disease (CHD). Accurate coronary artery calcification detection in noncontrast CTimage is a prerequisite step for coronary calcium scoring. Currently, calcified lesions in the coronary arteries are manually identified by radiologists in clinical practice. Thus, in this paper, a fully automatic calcium scoring method was developed to alleviate the work load of the radiologists or cardiologists.

Methods:

The challenge of automatic coronary calcification detection is to discriminate the calcification in the coronary arteries from the calcification in the other tissues. Since the anatomy of coronary arteries is difficult to be observed in the noncontrast CTimages, the contrastCTimage of the same patient is used to extract the regions of the aorta, heart, and coronary arteries. Then, a patient-specific region-of-interest (ROI) is generated in the noncontrast CTimage according to the segmentation results in the contrastCTimage. This patient-specific ROI focuses on the regions in the neighborhood of coronary arteries for calcification detection, which can eliminate the calcifications in the surrounding tissues. A support vector machine classifier is applied finally to refine the results by removing possible imagenoise. Furthermore, the calcified lesions in the noncontrast images belonging to the different main coronary arteries are identified automatically using the labeling results of the extracted coronary arteries.

Results:

Forty datasets from four different CT machine vendors were used to evaluate their algorithm, which were provided by the MICCAI 2014 Coronary Calcium Scoring (orCaScore) Challenge. The sensitivity and positive predictive value for the volume of detected calcifications are 0.989 and 0.948. Only one patient out of 40 patients had been assigned to the wrong risk category defined according to Agatston scores (0, 1–100, 101–300, >300) by comparing with the ground truth.

Conclusions:

The calcified lesions in the noncontrast CTimages can be detected automatically by using the segmentation results of the aorta, heart, and coronary arteries obtained in the contrastCTimages with a very high accuracy.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RZG65S
via IFTTT

A feasibility study of dynamic adaptive radiotherapy for nonsmall cell lung cancer

Purpose:

The final state of the tumor at the end of a radiotherapy course is dependent on the doses given in each fraction during the treatment course. This study investigates the feasibility of using dynamic adaptive radiotherapy (DART) in treatinglungcancers assuming CBCT is available to observe midtreatment tumor states. DART adapts treatment plans using a dynamic programming technique to consider the expected changes of the tumor in the optimization process.

Methods:

DART is constructed using a stochastic control formalism framework. It minimizes the total expected number of tumor cells at the end of a treatment course, which is equivalent to maximizing tumor control probability, subject to the uncertainty inherent in the tumor response. This formulation allows for nonstationary dose distributions as well as nonstationary fractional doses as needed to achieve a series of optimal plans that are conformal to the tumor over time, i.e., spatiotemporally optimal plans. Sixteen phantom cases with various sizes and locations of tumors and organs-at-risk (OAR) were generated using in-house software. Each case was planned with DART and conventional IMRT prescribing 60 Gy in 30 fractions. The observations of the change in the tumor volume over a treatment course were simulated using a two-level cell population model. Monte Carlo simulations of the treatment course for each case were run to account for uncertainty in the tumor response. The same OAR dose constraints were applied for both methods. The frequency of replanning was varied between 1, 2, 5 (weekly), and 29 times (daily). The final average tumordose and OAR doses have been compared to quantify the potential dosimetric benefits of DART.

Results:

The average tumor max, min, mean, and D95 doses using DART relative to these using conventional IMRT were 124.0%–125.2%, 102.1%–114.7%, 113.7%–123.4%, and 102.0%–115.9% (range dependent on the frequency of replanning). The average relative maximum doses for the cord and esophagus, mean doses for the heart and lungs, and D05 for the unspecified tissue resulting 84%–102.4%, 99.8%–106.9%, 66.9%–85.6%, 58.2%–78.8%, and 85.2%–94.0%, respectively.

Conclusions:

It is feasible to apply DART to the treatment of NSCLC using CBCT to observe the midtreatment tumor state. Potential increases in the tumordose and reductions in the OAR dose, particularly for parallel OARs with mean or dose–volume constraints, could be achieved using DART compared to nonadaptive IMRT.

from #Medicine via ola Kala on Inoreader http://ift.tt/1SNqhfC
via IFTTT

Polarity effects and apparent ion recombination in microionization chambers

Purpose:

Microchambers demonstrate anomalous voltage-dependent polarity effects. Existing polarity and ion recombination correction factors do not account for these effects. As a result, many commercial microchamber models do not meet the specification of a reference-class ionization chamber as defined by the American Association of Physicists in Medicine. The purpose of this investigation is to determine the cause of these voltage-dependent polarity effects.

Methods:

A series of microchamber prototypes were produced to isolate the source of the voltage-dependent polarity effects. Parameters including ionization-chamber collecting-volume size, stem and cable irradiation, chamber assembly, contaminants, high-Z materials, and individual chamber components were investigated. Measurements were performed with electrodes coated with graphite to isolate electrode conductivity. Chamber response was measured as the potential bias of the guard electrode was altered with respect to the collecting electrode, through the integration of additional power supplies. Ionization chamber models were also simulated using comsol Multiphysics software to investigate the effect of a potential difference between electrodes on electric field lines and collecting volume definition.

Results:

Investigations with microchamber prototypes demonstrated that the significant source of the voltage-dependent polarity effects was a potential difference between the guard and collecting electrodes of the chambers. The voltage-dependent polarity effects for each prototype were primarily isolated to either the guard or collecting electrode. Polarity effects were reduced by coating the isolated electrode with a conductive layer of graphite. Polarity effects were increased by introducing a potential difference between the electrodes.comsol simulations further demonstrated that for a given potential difference between electrodes, the collecting volume of the chamber changed as the applied voltage was altered, producing voltage-dependent polarity effects in the chamber response. Ionization chambermeasurements and comsol simulations demonstrated an inverse relationship between the chamber collecting volume size and the severity of voltage-dependent polarity effects on chamber response. The effect of a given potential difference on chamber polarity effects was roughly ten times greater for microchambers as compared to Farmer-type chambers. Stem and cable irradiations, chamber assembly, contaminants, and high-Z materials were not found to be a significant source of the voltage-dependent polarity effects.

Conclusions:

A potential difference between the guard and collecting electrodes was found to be the primary source of the voltage-dependent polarity effects demonstrated by microchambers. For a given potential difference between electrodes, the relative change in the collecting volume is smaller for larger-volume chambers, illustrating why these polarity effects are not seen in larger-volume chambers with similar guard and collecting electrode designs. Thus, for small-volume chambers, it is necessary to reduce the potential difference between the guard and collecting electrodes in order to reduce polarity effects for reference dosimetry measurements.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RZG5Py
via IFTTT

Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications

Purpose:

High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector.

Methods:

A 650 μm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 μm resulting in pixel pitch of 60 and 51.96 μm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 μGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function(MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit.

Results:

At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54 μm. After resampling to 54 μm square pixels using trilinear interpolation, the presampled MTF at Nyquist frequency of 9.26 cycles/mm was 0.29 and 0.24 along the orthogonal directions and the limiting resolution (10% MTF) occurred at approximately 12 cycles/mm. Visual analysis of a bar pattern image showed the ability to resolve close to 12 line-pairs/mm and qualitative evaluation of a neurovascular nitinol-stent showed the ability to visualize its struts at clinically relevant conditions.

Conclusions:

Hexagonal pixel array photon-counting CdTe detector provides high spatial resolution in single-photon counting mode. After resampling to optimal square pixel size for distortion-free display, the spatial resolution is preserved. The dual-energy capabilities of the detector could allow for artifact-free subtraction angiography and basis material decomposition. The proposed high-resolution photon-counting detector with energy-resolving capability can be of importance for several image-guided interventional procedures as well as for pediatric applications.

from #Medicine via ola Kala on Inoreader http://ift.tt/1SNqgZg
via IFTTT

Proton and light ion RBE for the induction of direct DNA double strand breaks

Purpose:

To present and characterize a Monte Carlo(MC) tool for the simulation of the relative biological effectiveness for the induction of direct DNA double strand breaks () for protons and light ions.

Methods:

The MC tool uses a pregenerated event-by-event tracks library of protons and light ions that are overlaid on a cell nucleus model. The cell nucleus model is a cylindrical arrangement of nucleosome structures consisting of 198 DNA base pairs. An algorithm relying on k-dimensional trees and cylindrical symmetries is used to search coincidences of energy deposition sites with volumes corresponding to the sugar–phosphate backbone of the DNA molecule. Strand breaks (SBs) are scored when energy higher than a threshold is reached in these volumes. Based on the number of affected strands, they are categorized into either single strand break (SSB) or double strand break (DSB) lesions. The number of SBs composing each lesion (i.e., its size) is also recorded. is obtained by taking the ratio of DSB yields of a given radiation field to a ⁶⁰Co field. The MC tool was used to obtain SSB yields, DSB yields, and as a function of linear energy transfer (LET) for protons (¹H⁺), ⁴He²⁺, ⁷Li³⁺, and ¹²C⁶⁺ ions.

Results:

For protons, the SSB yields decreased and the DSB yields increased with LET. At ≈24.5 keV μm⁻¹, protons generated 15% more DSBs than ¹²C⁶⁺ ions. The varied between 1.24 and 1.77 for proton fields between 8.5 and 30.2 keV μm⁻¹, and it was higher for iso-LET ions with lowest atomic number. The SSB and DSB lesion sizes showed significant differences for all radiation fields. Generally, the yields of SSB lesions of sizes ≥2 and the yields of DSB lesions of sizes ≥3 increased with LET and increased for iso-LET ions of lower atomic number. On the other hand, the ratios of SSB to DSB lesions of sizes 2–4 did not show variability with LET nor projectile atomic number, suggesting that these metrics are independent of the radiation quality. Finally, a variance of up to 8% in the DSB yields was observed as a function of the particle incidence angle on the cell nucleus. This simulation effect is due to the preferential alignment of ion tracks with the DNA nucleosomes at specific angles.

Conclusions:

The MC tool can predict SSB and DSB yields for light ions of various LET and estimate . In addition, it can calculate the frequencies of different DNA lesion sizes, which is of interest in the context of biologically relevant absolute dosimetry of particle beams.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RZG3He
via IFTTT

Pain and Physical Function After Bariatric Surgery

This cohort study compares changes in physical function and pain among obese patients 1 to 3 years after bariatric surgery (Roux-en-Y gastric bypass or laparoscopic adjustable gastric banding). Read the article at: http://bit.ly/1RNOPC7.

from #Medicine via ola Kala on Inoreader https://www.youtube.com/watch?v=YnVEgaIYAu8
via IFTTT

Estrogen Modulates Expression of Tight Junction Proteins in Rat Vagina

Background. The objectives of this study were to investigate the localization of tight junctions and the modulation of zonula occludens- (ZO-) 1, occludin and claudin-1 expression by estrogen in castrated female rat vagina. Female Sprague-Dawley rats (230–240 g, ) were divided into three groups and subjected to a sham operation (control group, ), bilateral ovariectomy (Ovx group, ), or bilateral ovariectomy followed by daily subcutaneous injection of 17β-estradiol (50 μg/kg/day, Ovx + Est group, ). The cellular localization and expression of ZO-1, occludin, and claudin-1 were determined in each group by immunohistochemistry and western blot. Results. Expression of ZO-1 was diffuse in all groups, with the highest intensity in the superficial epithelium in the control group. Occludin was localized in the intermediate and basal epithelium. Claudin-1 was most intense in the superficial layer of the vaginal epithelium in the control group. Expression of ZO-1, occludin, and claudin-1 was significantly decreased after ovariectomy and was restored to the level of the control after estrogen replacement. Conclusions. Tight junctions are distinctly localized in rat vagina, and estrogen modulates the expression of tight junctions. Further researches are needed to clarify the functional role of tight junctions in vaginal lubrication.

from #Medicine via ola Kala on Inoreader http://ift.tt/1S7YrHP
via IFTTT

Automatic Tissue Differentiation Based on Confocal Endomicroscopic Images for Intraoperative Guidance in Neurosurgery

Diagnosis of tumor and definition of tumor borders intraoperatively using fast histopathology is often not sufficiently informative primarily due to tissue architecture alteration during sample preparation step. Confocal laser microscopy (CLE) provides microscopic information of tissue in real-time on cellular and subcellular levels, where tissue characterization is possible. One major challenge is to categorize these images reliably during the surgery as quickly as possible. To address this, we propose an automated tissue differentiation algorithm based on the machine learning concept. During a training phase, a large number of image frames with known tissue types are analyzed and the most discriminant image-based signatures for various tissue types are identified. During the procedure, the algorithm uses the learnt image features to assign a proper tissue type to the acquired image frame. We have verified this method on the example of two types of brain tumors: glioblastoma and meningioma. The algorithm was trained using 117 image sequences containing over 27 thousand images captured from more than 20 patients. We achieved an average cross validation accuracy of better than 83%. We believe this algorithm could be a useful component to an intraoperative pathology system for guiding the resection procedure based on cellular level information.

from #Medicine via ola Kala on Inoreader http://ift.tt/238iYaB
via IFTTT

27.12 MHz Radiofrequency Ablation for Benign Cutaneous Lesions

As surgical and/or ablative modalities, radiofrequency (RF) has been known to produce good clinical outcomes in dermatology. Recently, 27.12 MHz RF has been introduced and has several advantages over conventional 4 or 6 MHz in terms of the precise ablation and lesser pain perception. We aimed to evaluate the clinical efficacy and safety of 27.12 MHz RF for the treatment of benign cutaneous lesions. Twenty female patient subjects were enrolled. Digital photography and a USB microscope camera were used to monitor the clinical results before one session of treatment with 27.12 MHz RF and after 1 and 3 weeks. Treated lesions included telangiectasias, cherry and spider angiomas, skin tags, seborrheic keratoses, lentigo, milium, dilated pore, acne, piercing hole, and one case of neurofibroma. For vascular lesions, clinical results were excellent for 33.3%, good for 44.4%, moderate for 11.1%, and poor for 11.1%. For nonvascular lesions (epidermal lesions and other benign cutaneous lesions), clinical results were excellent for 48.3%, good for 45.2%, moderate for 3.2%, and poor for 3.2%. No serious adverse events were observed. Mild adverse events reported were slight erythema, scale, and crust. The 27.12 MHz RF treatment of benign vascular and nonvascular lesions appears safe and effective after 3 weeks of follow-up.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RBTPhb
via IFTTT

Development of a method to estimate organ doses for pediatric CT examinations

Purpose:

To develop a method for estimating doses to primarily exposed organs in pediatric CT by taking into account patient size and automatic tube current modulation (ATCM).

Methods:

A Monte CarloCTdosimetrysoftware package, which creates patient-specific voxelized phantoms, accurately simulates CT exposures, and generates dose images depicting the energy imparted on the exposed volume, was used. Routine head, thorax, and abdomen/pelvis CT examinations in 92 pediatric patients, ranging from 1-month to 14-yr-old (49 boys and 43 girls), were simulated on a 64-slice CT scanner. Two sets of simulations were performed in each patient using (i) a fixed tube current (FTC) value over the entire examination length and (ii) the ATCM profile extracted from the DICOM header of the reconstructed images. Normalized to CTDIvol organ dose was derived for all primary irradiated radiosensitive organs. Normalized dose data were correlated to patient's water equivalent diameter using log-transformed linear regression analysis.

Results:

The maximum percent difference in normalized organ dose between FTC and ATCM acquisitions was 10% for eyes in head, 26% for thymus in thorax, and 76% for kidneys in abdomen/pelvis. In most of the organs, the correlation between dose and water equivalent diameter was significantly improved in ATCM compared to FTC acquisitions (P

Conclusions:

The proposed method employs size specific CTDIvol-normalized organ dose coefficients for ATCM-activated and FTC acquisitions in pediatric CT. These coefficients are substantially different between ATCM and FTC modes of operation and enable a more accurate assessment of patient-specific organ dose in the clinical setting.

from #Medicine via ola Kala on Inoreader http://ift.tt/1qrP4wI
via IFTTT

Cerebral perfusion computed tomography deconvolution via structure tensor total variation regularization

Purpose:

Cerebral perfusion computed tomography (PCT) imaging as an accurate and fast acute ischemic stroke examination has been widely used in clinic. Meanwhile, a major drawback of PCT imaging is the high radiation dose due to its dynamic scan protocol. The purpose of this work is to develop a robust perfusion deconvolution approach via structure tensor total variation (STV) regularization (PD-STV) for estimating an accurate residue function in PCT imaging with the low-milliampere-seconds (low-mAs) data acquisition.

Methods:

Besides modeling the spatio-temporal structure information of PCT data, the STV regularization of the present PD-STV approach can utilize the higher order derivatives of the residue function to enhance denoising performance. To minimize the objective function, the authors propose an effective iterative algorithm with a shrinkage/thresholding scheme. A simulation study on a digital brain perfusion phantom and a clinical study on an old infarction patient were conducted to validate and evaluate the performance of the present PD-STV approach.

Results:

In the digital phantom study, visual inspection and quantitative metrics (i.e., the normalized mean square error, the peak signal-to-noise ratio, and the universal quality index) assessments demonstrated that the PD-STV approach outperformed other existing approaches in terms of the performance of noise-induced artifacts reduction and accurate perfusion hemodynamic maps (PHM) estimation. In the patient data study, the present PD-STV approach could yield accurate PHM estimation with several noticeable gains over other existing approaches in terms of visual inspection and correlation analysis.

Conclusions:

This study demonstrated the feasibility and efficacy of the present PD-STV approach in utilizing STV regularization to improve the accuracy of residue function estimation of cerebral PCT imaging in the case of low-mAs.

from #Medicine via ola Kala on Inoreader http://ift.tt/1XeJuZ7
via IFTTT

Patient-centered diabetes research needs primary care perspectives

- Kenny Lin, MD, MPH

A Letter to the Editor in AFP's March 15th issue pointed out that a simplified management algorithm in a previous article on noninsulin therapies for type 2 diabetes could have been misinterpreted to suggest the non-recommended combination of a dipeptidyl-peptidase-4 (DPP-4) inhibitor and a glucagon-like-peptide-1 (GLP-1) receptor agonist. According to the American Diabetes Association's 2016 Standards of Medical Care in Diabetes, however, there is little comparative data to guide second-line drug choice after metformin. Few other medications have been shown to lower mortality in patients with type 2 diabetes, and even then only in specific populations, as Dr. Middleton discussed in a recent AFP Community Blog post.

The National Institutes of Health is currently recruiting patients for a multicenter randomized trial, the Glycemia Reduction Approaches to Diabetes: A Comparative Effectiveness (GRADE) study, that will compare the benefits and harms of four medications commonly combined with metformin: 1) glimepride (a sulfonylurea); 2) sitagliptin (a DPP-4 inhibitor); 3) liraglutide (a GLP-1 receptor agonist); and 4) glargine insulin. Since the GRADE study was planned, the sodium glucose cotransporter 2 (SGLT-2) inhibitor class has come on the market, and a randomized trial found that empagliflozin reduces cardiovascular and all-cause mortality in patients with established cardiovascular disease and type 2 diabetes. This surprising result led some experts to suggest that SGLT-2 inhibitors be added to the GRADE trial or incorporated into some other comparative research study.

This kind of pragmatic diabetes research would seem to be a perfect fit for the Patient-Centered Outcomes Research Institute (PCORI). Created by the Affordable Care Act, PCORI's mission is to "improve the quality and relevance of evidence available to help patients, caregivers, clinicians, employers, insurers, and policy makers make informed health decisions" by funding comparative clinical effectiveness research and research methods. However, PCORI received criticism recently after an independent analysis of its first 6 funding cycles by the American Academy of Family Physicians' Robert Graham Center concluded that "less than one-third of PCORI studies involve or are relevant to primary care."

Last month, I represented the AAFP in the PCORI stakeholder workshop "Prioritizing Comparative Effectiveness Research for Second-Line Type 2 Diabetes Treatment." Other workshop participants included fellow primary care clinicians and representatives from relevant subspecialty societies, patient groups, benefits managers, clinical investigators, and the pharmaceutical industry. After listening to presentations on recent trials and the GRADE study, we were asked to formulate a research question in the PICO (Population, Intervention, Comparator, Outcome) format, keeping in mind the following criteria: patient-centeredness, health impact of the condition, assessment of current options, likelihood of implementation in practice, and durability of information.

I was impressed by the high quality of the discussion and the group's determination to come up with practical research questions that would provide meaningful answers to better inform family physicians and other clinicians who care for patients with type 2 diabetes. PCORI Executive Director Joe Selby, MD, MPH, who is also a family physician, told me how important it was to him that Family Medicine be actively engaged in shaping the organization's research agenda and priorities. For interested readers, PCORI offers many opportunities to get involved that range from suggesting new research questions, to providing input on current questions and methods, to serving on standing advisory panels on various cross-cutting topics.

from #Medicine via ola Kala on Inoreader http://ift.tt/1qrNBXe
via IFTTT

Importance of an early diagnosis in primary adenocarcinoma of the seminal vesicle

The prognosis of seminal vesicle (SV) adenocarcinoma is often poor due to delayed diagnosis. About 95% of the patients die in less than 3 years. Diagnosis is difficult due to the absence of early clinical signs as hematuria, hematospermia and/or dysuria. We present the case of a 61-year-old Caucasian man with a left SV mass detected by transrectal ultrasound. SV ultrasound-guided biopsy showed an adenocarcinoma. The tumor was uniformly strongly immunoreactive for cytokeratin-7 and carcinoembryonic antigen. There was no immunoreactivity for prostate-specific acid phosphatase (PSAP) and CK-20. These tumors have been reported to be also positive for CA- 125. Therefore a combination of positive staining for CK-7, CEA and CA-125; with negative staining for CK-20, PSA and PSAP is the pattern of immunohistochemical findings noted for this rare tumor. The computed tomography of the abdomen-pelvis and chest X-ray was negative for metastases. The patient underwent a radical prostatectomy and lymphadenectomy. The prostate, rectum, bladder and lymph nodes were free from tumor involvement. The patient did not receive any adjuvant chemotherapy or radiation; and remains free of disease 3 years post-surgery.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RZnByt
via IFTTT

Buildings, Vol. 6, Pages 16: Hourly Calculation Method of Air Source Heat Pump Behavior

The paper describes an hourly simplified model for the evaluation of the energy performance of heat pumps in cooling mode maintaining a high accuracy and low computational cost. This approach differs from the methods used for the assessment of the overall energy consumption of the building, normally placed in the so-called white or black box models, where the transient conduction equation is deterministically and stochastically solved, respectively. The present method wants to be the expression of the grey box model, taking place between the previous approaches. The building envelope is defined using a building thermal model realized with a 3 Resistance 1 Capacitance (3R1C) thermal network based on the solution of the lumped capacitance method. The simplified model evaluates the energy efficiency ratio (EER) of a heat pump through the determination of the hourly second law efficiency of a reversed Carnot cycle. The results of the simplified method were finally compared with those provided by EnergyPlus, a dynamic building energy simulation program, and those collected from an outdoor test cell in real working conditions. The results are presented in temperatures and energy consumptions profiles and are validated using the Bland-Altman test.

from #Medicine via ola Kala on Inoreader http://ift.tt/1RBWNT3
via IFTTT

Architecture of the sperm whale forehead facilitates ramming combat

Herman Melville's novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the "spermaceti organ" and "junk," that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the spermaceti organ would reduce skull stresses, it would also cause high compressive stresses on the anterior aspect of the organ and the connective tissue case, possibly making these structures more prone to failure. This outcome, coupled with the facts that the spermaceti organ houses sensitive and essential sonar producing structures and the rostral portion of junk, rather than the spermaceti organ, is frequently a site of significant scarring in mature males suggest that whales avoid impact with the spermaceti organ. Although the unique structure of the junk certainly serves multiple functions, our results are consistent with the hypothesis that the structure also evolved to function as a massive battering ram during male-male competition.

from #Medicine via ola Kala on Inoreader http://ift.tt/229aABZ
via IFTTT

Developmental Psychobiology: Volume 58, Number 4, May 2016

from #Medicine via ola Kala on Inoreader http://ift.tt/1MaWEWq
via IFTTT

Issue Information

from #Medicine via ola Kala on Inoreader http://ift.tt/1SxRBvQ
via IFTTT