Telehealth-Delivered Program and Accompanying Patients to Enhance the Clinical Condition of Patients Throughout a Liver Transplant: Protocol for a Mixed Methods Study

BACKGROUND

Liver transplantation (LT) is indicated in patients with severe acute or chronic liver failure for which no other therapy is available. With the increasing number of LTs in recent years, liver centers worldwide must manage their patients according to their clinical situation and the expected waiting time for transplantation. The LT clinic at the Centre hospitalier de l'Université de Montréal (CHUM) is developing a new health care model across the entire continuum of pre-, peri-, and posttransplant care that features patient monitoring by an interdisciplinary team, including an accompanying patient; a digital platform to host a clinical plan; a learning program; and data collection from connected objects.

OBJECTIVE

This study aims to (1) evaluate the outcomes following the implementation of a patient platform with connected devices and an accompanying patient, (2) identify implementation barriers and facilitators, (3) describe service outcomes in terms of health outcomes and the rates and nature of contact with the accompanying patient, (4) describe patient outcomes, and (5) assess the intervention's cost-effectiveness.

METHODS

Six types of participants will be included in the study: (1) patients who received transplants and reached 1 year after transplantation before September 2023 (historical cohort or control group), (2) patients who will receive an LT between December 2023 and November 2024 (prospective cohort/intervention group), (3) relatives of those patients, (4) accompanying patients who have received an LT and are interested in supporting patients who will receive an LT, (5) health care professionals, and (6) decision makers. To describe the study sample and collect data to achieve all the objectives, a series of validated questionnaires, accompanying patient logbooks, transcripts of interviews and focus groups, and clinical indicators will be collected throughout the study.

RESULTS

In total, 5 (steering, education, clinical-technological, nurse prescription, and accompanying patient) working committees have been established for the study. Recruitment of patients is expected to start in November 2023. All questionnaires and technological platforms have been prepared, and the clinicians, stakeholders, and accompanying patient personnel have been recruited.

CONCLUSIONS

The implementation of this model in the trajectory of LT recipients at the CHUM may allow for better monitoring and health of patients undergoing transplantation, ultimately reducing the average length of hospital stay and promoting better use of medical resources. In the event of positive results, this model could be transposed to all transplant units at the CHUM and across Quebec (potentially affecting 888 patients per year) but could also be applied more widely to the monitoring of patients with other chronic diseases. The lessons learned from this project will be shared with decision makers and will serve as a model for other initiatives involving accompanying patients, connected objects, or digital platforms.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/54440.

Argonaute3-SF3B3 complex controls pre-mRNA splicing to restrain type 2 immunity

Argonaute (AGO) proteins execute microRNA (miRNA)-mediated gene silencing. However, it is unclear whether all 4 mammalian AGO proteins (AGO1, AGO2, AGO3, and AGO4) are required for miRNA activity. We generate Ago1, Ago3, and Ago4-deficient mice (Ago134Δ) and find AGO1/3/4 to be redundant for miRNA biogenesis, homeostasis, or function, a role that is carried out by AGO2. Instead, AGO1/3/4 regulate the expansion of type 2 immunity via precursor mRNA splicing in CD4+ T helper (Th) lymphocytes. Gain- and loss-of-function experiments demonstrate that nuclear AGO3 interacts directly with SF3B3, a component of the U2 spliceosome complex, to aid global mRNA splicing, and in particular the isoforms of the gene Nisch, resulting in a dysregulated Nisch isoform ratio. This work uncouples AGO1, AGO3, and AGO4 from miRNA-mediated RNA interference, identifies an AGO3:SF3B3 complex in the nucleus, and reveals a mechanism by which AGO proteins regulate inflammatory diseases.

Fatigue risk assessment of a Helicopter Emergency Medical Service crew working a 24/7 shift pattern: results of a prospective service evaluation

BACKGROUND

The work of Helicopter Emergency Medical Services (HEMS) teams crosses the boundaries of several high-risk occupations including medicine, aviation, and transport. Working conditions can be challenging and operational demands requires a 24-h rota, resulting in disruption of the normal circadian rhythm. HEMS crews are therefore prone to both mental and physical fatigue. As fatigue in medical providers is linked to poor cognitive performance, degradation of psychomotor skills and error, this study aimed to explore the existence of predictable patterns of crew-fatigue in a HEMS service.

METHODS

HEMS medical crew members working a 3-on 3-off forward rotating rota with a 5-week shift cycle were asked to do psychomotor vigilance tests (PVT) as an objective measure of fatigue. PVT testing was undertaken at the start, mid- and at the end of every shift during a full 5-week shift cycle. In addition, they were asked to score subjective tiredness with the Samn-Perelli Fatigue Scale (SPFS), and to keep a Transport Fatigue Assessment shift log, wherein they noted shift characteristics potentially related to fatigue. Primary outcome of interest was defined as the change in PVT and SPFS scores over time.

RESULTS

Mean baseline resting PVT in milliseconds at the start of the study period was 427 [390-464]. There was an overall trend towards higher PVT-scores with shift progression mean [95% CI] PVT at the start of shifts 447 [433-460]; halfway through the shift 452 [440-463]; end of the shift 459 [444-475], p = 0.10), whereas SPFS scores remained constant. Within a 5 week forward-rotating cycle, an overall trend towards a gradual increase in both average PVT (from 436 [238-454] to 460 [371-527, p = 0.68] ms;) and SPFS (from 2.9 [2.6-3.2] to 3.6 [3.1-4.0], p = 0.38) was observed, although significant interindividual variation was present. Reported SPFS scores ≥ 4 (moderate fatigue) were mainly related to workload (number of jobs) and transport mode (car-based shifts).

CONCLUSION

An overall trend towards a decline in psychomotor vigilance and an increase in self-reported tiredness was found for HEMS crew over a 5-week shift cycle. Using a bespoke predictive fatigue tool on a day-to-day basis could increase fatigue awareness and provide a framework to which relevant mitigating options can be applied.

Factors correlated with pain after total knee arthroplasty: A systematic review and meta-analysis

MAIN OBJECTIVE

Systematically review and synthesize preoperative and intraoperative factors associated with pain after total knee arthroplasty (TKA) in patients with osteoarthritis.

METHODS

Based on a peer-reviewed protocol, we searched Medline, Embase, CINAHL, Cochrane Library, and PEDro for prospective observational studies (January 2000 to February 2023) investigating factors associated with pain after TKA. The primary outcome was pain twelve months after TKA. Pain at three and six months were secondary outcomes. Multivariate random-effects meta-analyses were used to estimate mean correlation (95% CIs) between factors and pain. Sensitivity analysis was performed for each risk of bias domain and certainty of evidence was assessed.

RESULTS

Of 13,640 studies, 29 reports of 10,360 patients and 61 factors were analysed. The mean correlation between preoperative factors and more severe pain at twelve months was estimated to be 0.36 (95% CI, 0.24, 0.47; P < .000; moderate-certainty evidence) for more catastrophizing, 0.15 (95% CI; 0.08, 0.23; P < .001; moderate-certainty evidence) for more symptomatic joints, 0.13 (95% CI, 0.06, 0.19; P < .001; very low-certainty evidence) for more preoperative pain. Mean correlation between more severe radiographic osteoarthritis and less pain was -0.15 (95% CI; -0.23, -0.08; P < .001; low-certainty evidence). In sensitivity analysis, the estimated correlation coefficient for pain catastrophizing factor increased to 0.38 (95% CI 0.04, 0.64). At six and three months, more severe preoperative pain was associated with more pain. Better preoperative mental health was associated with less pain at six months.

CONCLUSION AND RELEVANCE

More pain catastrophizing, more symptomatic joints and more pain preoperatively were correlated with more pain, while more severe osteoarthritis was correlated with less pain one year after TKA. More preoperative pain was correlated with more pain, and better mental health with less pain at six and three months. These findings should be further tested in predictive models to gain knowledge which may improve TKA outcomes.

Relationship between cardiovascular symptoms, health status assessment and cardiomyopathy in the obstetric population

Background

Pregnancy related cardiomyopathy is a significant cause of maternal morbidity and mortality globally. A presumed overlap between normal pregnancy-associated symptoms and clinical symptoms of cardiomyopathy contributes to delays in diagnosis and increased risk of maternal mortality.

Purpose

We sought to evaluate the association between patient-reported cardiovascular symptoms and the presence of cardiomyopathy among pregnant and postpartum patients. We hypothesize that individual cardiovascular symptoms are unrelated to the presence of cardiomyopathy. We also evaluated the use of a novel adaptation of a validated health status questionnaire in relation to cardiomyopathy.

Methods

We enrolled 48 pregnant (&gt;13 weeks) and postpartum (up to 12 months) participants in a prospective study between October 2021 and February 2022. All study participants completed a baseline questionnaire, which included current cardiovascular symptoms, an assessment of health status using an adapted version of the Kansas City Cardiomyopathy Questionnaire (KCCQ-12), followed by a resting transthoracic echocardiogram on the same day. We defined cardiomyopathy as a left ventricular ejection fraction (LVEF) &lt;50% based on 2-D echocardiography. Fisher's exact and Wilcoxon rank-sum tests were employed to evaluate the association between reported cardiovascular symptoms, the adapted KCCQ-12 (KCC-A) score, and cardiomyopathy.

Results

At the time of enrollment, 67% were pregnant and 33% postpartum. Forty-eight percent identified as White, 31% as Black, 10% as Asian, and 10% as other race. The median age was 31 years (Q1: 28, Q3: 35) and 6% had an LVEF &lt;50%. We found no statistically significant association between four reported cardiovascular symptoms (shortness of breath, orthopnea, fast breathing, and episodes of “asthma” that did not improve with inhalers or other treatment) and cardiomyopathy or medial E/e' ratio. KCC-A scores were low in the study population overall (median 52; Q1:40, Q3: 61). We demonstrated a significantly lower KCC-A score among women with LVEF &lt;50% (median 24; Q1: 15, Q3: 44) compared to women with LVEF ≥50% (median 54; Q1: 44, Q3: 61) p=0.02.

Conclusions

We showed no significant association between individual cardiovascular symptoms and cardiomyopathy in an obstetric population. However, we demonstrate for the first time that an adapted KCCQ-12 questionnaire for health status assessment could potentially identify women with a high-likelihood of cardiomyopathy during the peripartum period who may benefit from additional evaluation including echocardiography. Larger studies are needed to validate this finding.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This study was funded by a research grant from the Miami Heart Research Institute, Florida Heart Foundation. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health

Factors Correlated With Physical Function 1 Year After Total Knee Arthroplasty in Patients With Knee Osteoarthritis: A Systematic Review and Meta-analysis

IMPORTANCE

More than 1 in 5 patients do not experience improved physical function after total knee arthroplasty (TKA). Identification of factors associated with physical function may be warranted to improve outcomes in these patients.

OBJECTIVE

To identify preoperative and intraoperative factors associated with physical function at 12 months after TKA in a systematic review and meta-analysis.

DATA SOURCES

Data from January 2000 to October 2021 were searched in Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, and Physiotherapy Evidence Database (PEDro). No language restrictions were applied.

STUDY SELECTION

Prospective observational studies or randomized clinical trials on factors associated with physical function after TKA in adult patients with osteoarthritis were selected. A prespecified peer-reviewed protocol was followed.

DATA EXTRACTION AND SYNTHESIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline, 2 reviewers independently screened titles and abstracts and judged risk of bias using Quality in Prognosis Studies (QUIPS). Multivariate random-effects meta-analyses were performed to estimate mean correlations between factors and physical function with 95% CIs. Sensitivity analyses were conducted for each QUIPS domain. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development and Evaluations (GRADE). This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO).

MAIN OUTCOMES AND MEASURES

The primary outcome was physical function 12 months after TKA. Secondary outcomes were physical function 3 and 6 months after TKA. All estimates are mean correlations between factors and postoperative function. Positive correlations correspond to better function.

RESULTS

Among 12 052 articles, 20 studies (including 11 317 patients and 37 factors) were analyzed. Mean correlation with higher BMI was estimated to be -0.15 (95% CI, -0.24 to -0.05; P = .33; moderate-certainty evidence), while mean correlation with better physical function was estimated to be 0.14 (95% CI, 0.02 to 0.26; P = .03; low-certainty evidence) and mean correlation with more severe osteoarthritis was estimated to be 0.10 (95% CI, 0.01 to 0.19; P = .17; high-certainty evidence). In sensitivity analyses, mean correlation with better physical function was estimated to be 0.20 (95% CI, 0.04 to 0.36; P = .02), and so perhaps a larger coefficient than in the main analysis, while mean correlations were estimated to be similar for other factors (BMI: -0.17; 95% CI, -0.28 to -0.06; P < .001; osteoarthritis severity: 0.10; 95% CI, -0.01 to 0.20; P = .05).

CONCLUSIONS AND RELEVANCE

This study found that higher presurgical BMI was correlated with worse physical function (with moderate certainty) and that better physical function (low certainty) and osteoarthritis severity (high certainty) were correlated with better physical function after TKA. These findings suggest that these factors should be included when testing predictive models of TKA outcomes.

Towards harmonizing clinical linear energy transfer (LET) reporting in proton radiotherapy: a European multi-centric study

BACKGROUND

Clinical data suggest that the relative biological effectiveness (RBE) in proton therapy (PT) varies with linear energy transfer (LET). However, LET calculations are neither standardized nor available in clinical routine. Here, the status of LET calculations among European PT institutions and their comparability are assessed.

MATERIALS AND METHODS

Eight European PT institutions used suitable treatment planning systems with their center-specific beam model to create treatment plans in a water phantom covering different field arrangements and fulfilling commonly agreed dose objectives. They employed their locally established LET simulation environments and procedures to determine the corresponding LET distributions. Dose distributions D1.1 and DRBE assuming constant and variable RBE, respectively, and LET were compared among the institutions. Inter-center variability was assessed based on dose- and LET-volume-histogram parameters.

RESULTS

Treatment plans from six institutions fulfilled all clinical goals and were eligible for common analysis. D1.1 distributions in the target volume were comparable among PT institutions. However, corresponding LET values varied substantially between institutions for all field arrangements, primarily due to differences in LET averaging technique and considered secondary particle spectra. Consequently, DRBE using non-harmonized LET calculations increased inter-center dose variations substantially compared to D1.1 and significantly in mean dose to the target volume of perpendicular and opposing field arrangements (p < 0.05). Harmonizing LET reporting (dose-averaging, all protons, LET to water or to unit density tissue) reduced the inter-center variability in LET to the order of 10-15% within and outside the target volume for all beam arrangements. Consequentially, inter-institutional variability in DRBE decreased to that observed for D1.1.

CONCLUSION

Harmonizing the reported LET among PT centers is feasible and allows for consistent multi-centric analysis and reporting of tumor control and toxicity in view of a variable RBE. It may serve as basis for harmonized variable RBE dose prescription in PT.

Wound healing and Metabolite Profiling in Collagen-Chitosan Biomaterial-treated Chronic Wounds of Hansen’s Disease Patients

Aims: Impaired wound healing causes chronic ulcers in Hansen’s disease (HD) patients which are an unrecognized clinical manifestation and requires utmost care and attention for wound management. Collagen and chitosan biopolymers when synergistically combined produce a biologically active biomaterial for wound dressings. Hence, the aim was to prepare a collagen/chitosan (COL/CS) composite and characterize for wound healing potential in HD patients. Place and Duration of Study: CSIR-Central Leather Research Institute, Sardar Patel Road, Adyar, Chennai 600021, Southern Railway Headquarters Hospital, Constable Road, Ayanavaram, Chennai 600023, and Gremaltes Hospital, India between June 2013 and July 2020. Methodology: The HD wounds were measured by Planimetry in square cm and were also assessed for morphological structure of epidermis and collagen fiber arrangement by High Resolution- Scanning electron microscopy (HR-SEM).  Proton Nuclear magnetic resonance spectroscopy (1H-NMR) for metabolite identification was studied in blood plasma samples of unwounded, untreated and treated HD patients Results: Size D (wound size on day of discharge) of the wounds were appreciably lower than Size 0 (wound size before biomaterial treatment) demonstrating efficient wound healing by the biomaterial. The morphological structure of the HD wounds showed healthy epidermal layer and thick fibers of collagen matrix in the treated wounds when compared to the controls. Key metabolites of metabolic pathways such as TCA cycle, creatine cycle and protein metabolism were identified by 1H-NMR spectroscopy Conclusion: The COL/CS wound dressing is a promising biomaterial for management of chronic wounds in Hansen’s disease.

Collagen-Chitosan Composite Powder as a Novel Biomaterial for Chronic Wounds in Hansen Disease-A Clinical Study

Aims: Natural biomaterials are more suitable than synthetic biomaterials for in vivo applications for treating damaged tissues. Collagen and chitosan are abundantly available natural biomaterials for wound dressings for tissue/wound repair. In this context, collagen-chitosan composite powder has been used to treat chronic wounds in Hansen disease (HD) patients. Place and Duration of Study: CSIR Central Leather Research Institute, Sardar Patel Road, Adyar, Chennai 600021, Southern Railway Headquarters Hospital, Constable Road, Ayanavaram, Chennai 600023, and Gremaltes Hospital, India between June 2013 and July 2020. Methodology: Collagen extracted from bovine rumen, a waste product of meat industry, and a commercially available chitosan were prepared as a composite powder (COL/CS) and applied to chronic wounds in HD patients after debridement and the wound contours were measured by planimetry. Biochemical parameters in blood samples were periodically assessed. Histopathology of wound tissue with Hematoxylin and Eosin and Masson’s Trichrome staining was studied. Matrix Metalloproteinase-9 (MMP9) levels before and after treatment were estimated. Results: Wound healing of 64.2% was obtained with COL/CS treatment and formation of granulation cells was observed early. Hemogram studies have been reported in a regression model with 95% confidence intervals. Histopathology revealed dense collagen fibres and continuity of sub-epithelial layer on 8th day. MMP-9 levels showed collagen integrity after treatment. Conclusion: The novel biocompatible, biodegradable COL/CS wound dressing is a promising biomaterial for management of chronic wounds in Hansen disease patients.

Prevalence and Disparities in Folate and Vitamin B12 Deficiency Among Preschool Children in Guatemala

BACKGROUND AND OBJECTIVE

Folate and vitamin B12 deficiencies can impair proper growth and brain development in children. Data on the folate and vitamin B12 status of children aged 6-59 months in Guatemala are scarce. Identification of factors associated with higher prevalence of these micronutrient deficiencies within the population is needed for national and regional policymakers.

OBJECTIVE

To describe national and regional post-fortification folate and vitamin B12 status of children aged 6-59 months in Guatemala.

METHODS

A multistage, cluster probability study was carried out with national and regional representation of children aged 6-59 months. Demographic and health information was collected for 1246 preschool children, but blood samples for red blood cell (RBC) folate and vitamin B12 were collected and analyzed for 1,245 and 1143 preschool children, respectively. We used the following deficiency criteria as cutoff points for the analyses: < 305 nmol/L for RBC folate, < 148 pmol/L for vitamin B12 deficiency, and 148-221 pmol/L for marginal vitamin B12 deficiency. Prevalence of RBC folate deficiency and vitamin B12 deficiency and marginal deficiency were estimated. Prevalence risk ratios of RBC folate and vitamin B12 deficiency were estimated comparing subpopulations of interest.

RESULTS

The national prevalence estimates of RBC folate deficiency among children was 33.5% [95% CI 29.1, 38.3]. The prevalence of RBC folate deficiency showed wide variation by age (20.3-46.6%) and was significantly higher among children 6-11 months and 12-23 months (46.6 and 37.0%, respectively), compared to older children aged 48-59 months (20.3%). RBC folate deficiency also varied widely by household wealth index (22.6-42.0%) and geographic region (27.2-46.7%) though the differences were not statistically significant. The national geometric mean for RBC folate concentrations was 354.2 nmol/L. The national prevalences of vitamin B12 deficiency and marginal deficiency among children were 22.5% [95% CI 18.2, 27.5] and 27.5% [95% CI 23.7, 31.7], respectively. The prevalence of vitamin B12 deficiency was significantly higher among indigenous children than among non-indigenous children (34.5% vs. 13.1%, aPRR 2.1 95% CI 1.4, 3.0). The prevalence of vitamin B12 deficiency also significantly varied between the highest and lowest household wealth index (34.3 and 6.0%, respectively). The national geometric mean for vitamin B12 concentrations was 235.1 pmol/L. The geometric means of folate and B12 concentrations were significantly lower among children who were younger, had a lower household wealth index, and were indigenous (for vitamin B12 only). Folate and vitamin B12 concentrations showed wide variation by region (not statistically significant), and the Petén and Norte regions showed the lowest RBC folate and vitamin B12 concentrations, respectively.

CONCLUSIONS

In this study, a third of all children had RBC folate deficiency and half were vitamin B12 deficient. Folate deficiency was more common in younger children and vitamin B12 deficiency was more common in indigenous children and those from the poorest families. These findings suggest gaps in the coverage of fortification and the need for additional implementation strategies to address these gaps in coverage to help safeguard the health of Guatemalan children.

Heterogeneity in susceptibility dictates the order of epidemic models

The fundamental models of epidemiology describe the progression of an infectious disease through a population using compartmentalized differential equations, but typically do not incorporate population-level heterogeneity in infection susceptibility. Here we combine a generalized analytical framework of contagion with computational models of epidemic dynamics to show that variation strongly influences the rate of infection, while the infection process simultaneously sculpts the susceptibility distribution. These joint dynamics influence the force of infection and are, in turn, influenced by the shape of the initial variability. We find that certain susceptibility distributions (the exponential and the gamma) are unchanged through the course of the outbreak, and lead naturally to power-law behavior in the force of infection; other distributions are often sculpted towards these "eigen-distributions" through the process of contagion. The power-law behavior fundamentally alters predictions of the long-term infection rate, and suggests that first-order epidemic models that are parameterized in the exponential-like phase may systematically and significantly over-estimate the final severity of the outbreak. In summary, our study suggests the need to examine the shape of susceptibility in natural populations as part of efforts to improve prediction models and to prioritize interventions that leverage heterogeneity to mitigate against spread.

Secret messaging with endogenous chemistry

Data encoded in molecules offers opportunities for secret messaging and extreme information density. Here, we explore how the same chemical and physical dimensions used to encode molecular information can expose molecular messages to detection and manipulation. To address these vulnerabilities, we write data using an object's pre-existing surface chemistry in ways that are indistinguishable from the original substrate. While it is simple to embed chemical information onto common objects (covers) using routine steganographic permutation, chemically embedded covers are found to be resistant to detection by sophisticated analytical tools. Using Turbo codes for efficient digital error correction, we demonstrate recovery of secret keys hidden in the pre-existing chemistry of American one dollar bills. These demonstrations highlight ways to improve security in other molecular domains, and show how the chemical fingerprints of common objects can be harnessed for data storage and communication.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV)

INTRODUCTION

Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH.

METHODS

The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF).

RESULTS

The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix).

CONCLUSION

These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

Implementing parallel arithmetic via acetylation and its application to chemical image processing

Chemical mixtures can be leveraged to store large amounts of data in a highly compact form and have the potential for massive scalability owing to the use of large-scale molecular libraries. With the parallelism that comes from having many species available, chemical-based memory can also provide the physical substrate for computation with increased throughput. Here, we represent non-binary matrices in chemical solutions and perform multiple matrix multiplications and additions, in parallel, using chemical reactions. As a case study, we demonstrate image processing, in which small greyscale images are encoded in chemical mixtures and kernel-based convolutions are performed using phenol acetylation reactions. In these experiments, we use the measured concentrations of reaction products (phenyl acetates) to reconstruct the output image. In addition, we establish the chemical criteria required to realize chemical image processing and validate reaction-based multiplication. Most importantly, this work shows that fundamental arithmetic operations can be reliably carried out with chemical reactions. Our approach could serve as a basis for developing more advanced chemical computing architectures.

Leveraging autocatalytic reactions for chemical domain image classification

Autocatalysis is fundamental to many biological processes, and kinetic models of autocatalytic reactions have mathematical forms similar to activation functions used in artificial neural networks. Inspired by these similarities, we use an autocatalytic reaction, the copper-catalyzed azide-alkyne cycloaddition, to perform digital image recognition tasks. Images are encoded in the concentration of a catalyst across an array of liquid samples, and the classification is performed with a sequence of automated fluid transfers. The outputs of the operations are monitored using UV-vis spectroscopy. The growing interest in molecular information storage suggests that methods for computing in chemistry will become increasingly important for querying and manipulating molecular memory.

Faire face au COVID-19, mise en place de novo d’une unité mutualisée « COVID-19 non réanimatoire » : organisation et résultats

Introduction

La pandémie à COVID-19 a touché presque tous les pays du monde, dont la France. Tous les départements français ont ouvert des unités dédiées pour la gestion de la phase aiguë de l’épidémie. Au sein de notre site, notre structure a été la seule à accueillir une unité pour gérer des patients confirmés COVID-19 positifs. En l’absence de soins intensifs sur place, ces patients étaient triés au SAU et ne venaient que les patients sans indication de soins intensifs en raison du bénéfice/risque attendu (âge, comorbidités). Pour activer cette unité, une équipe mutualisée a été mise en place que ce soit au niveau du personnel médical PM (seniors, internes, externes) que personnel non médical (PNM) détachés des services de médecine interne, pédiatrie, médecine du sport, consultation, endocrinologie, hépatologie de notre CHU. Un support psychologique a été proposé aux soignants et aux familles par une équipe mobile de psychiatrie. L’activité quotidienne a été réorganisée après la création de plusieurs binômes junior-senior, en service de 8 h à 19 h, 7 j/7. La continuité des soins a été assurée chaque jour par 3 staffs pour permettre respectivement les transmissions de la nuit entre PM et PNM ; l’état des lieux après la visite du matin ; les projets pour le lendemain. Tous les patients ont été réévalués chaque jour et réorientés selon une échelle de gravité structurée par 5 codes-couleurs. Les externes ont eu pour mission de contacter les familles du fait de la limitation des visites, ainsi que les médecins traitants afin d’améliorer la gestion après le RAD. Les patients ont été traités par oxygénothérapie et protocoles d’antibiothérapie et morphine.

Matériels et méthodes

Analyse descriptive des données personnelles, de la mortalité brute et des issues de l’hospitalisation.

Résultats

Entre le 13 mars et le 19 mai, 147 patients, 56 % d’eux de sexe féminin, ont été hospitalisés dans cette unité d’une capacité maximale de 25 lits. L’âge moyen était de 69 ans [18 ; 97]. La durée moyenne du séjour a été de 5 jours [0 : 29]. La mortalité totale était du 20,4 %, dont 51 % des patients sont rentrés vers leur domicile ou vers des EHPAD. Ensuite, 14,3 % des patients ont été transférés vers un autre service de médecine aiguë, et 12,2 % des patients a poursuit les soins dans un SSR.

Conclusion

L’organisation de ce service montre comme une équipe de PM et PNM avec fonds de travail différentes peut être rapidement mise en place pendant une période de crise. La présence d’un service dédié à la gestion des cas de COVID-19 sans indication à soins intensifs peut soulager des autres services au sein d‘un groupe hospitalier qui travaille en coordination. La mortalité des patients hospitalisés dans ce service reste baisse considérant les comorbidités et l’âge des patients. La durée courte du séjour a permis d’accueillir un grand nombre de patients et de garantir de places en médecine aiguë standard au sein du GH.

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Attenuation of oxidative stress in arthritic rats by ethanolic extract of Albizia procera benth bark through modulation of the expression of inflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia procera L. (Leguminosae) commonly known as Konda vagai in Tamil, is used for the treatment of stomach and intestinal disorders. A decoction of the bark is prescribed for rheumatism and haemorrhage. Traditionally, literature claims Albizia procera as a drug to have antirheumatic properties and hence used by Tribal for the management of chronic rheumatism. Consequently, the present study has been undertaken to illustrate the beneficial outcome of Albizia procera in adjuvant induced arthritic rat model with respect to its antioxidant and anti-inflammatory activities.

AIM OF THE STUDY

The present study is aimed to investigate the oxidative stress and the expression of inflammatory markers in arthritic rats treated with ethanolic bark extract of Albizia procera.

MATERIALS AND METHODS

Ethanolic bark extract was characterized by HPTLC analysis. Acute oral toxicity study was performed according to the OECD test guideline 423 - Acute toxic class method. The anti-inflammatory effect of ETBE (100, 200 mg/kg/day/p.o.) was evaluated in complete Freund's adjuvant induced arthritic rats using diclofenac as positive control (0.3 mg/kg/day/p. o.). Plasma levels of interleukins TNF- α, IFN-α, IL-2, IL-6, myeloperoxidase and Cathepsin D levels were measured to assess the inflammatory effect of ETBE extract of Albizia procera. Further, the effect of ETBE on superoxide dismutase (SOD), glutathione peroxidase (GPX), reduced glutathione (GSH) and lipid peroxidation (LPO) were assessed in plasma.

RESULTS

HPTLC analysis showed the presence of 0.57% w/w of biochanin-A in ETBE. ETBE did not show any toxic signs up to 2000 mg/kg body weight. It exhibited the significant anti-inflammatory and antioxidant potential and did not show mortality up to 2000 mg/kg body weight. ETBE treatment significantly reduced the levels of TNF- α, IFN-α, IL-2, IL-6 and myeloperoxidase, and increased cathepsin D levels compared to vehicle treated animals. SOD, GSH and GPX levels were significantly restored to normal levels while LPO was significantly reduced at 200 mg/kg b. wt. Treated animals. Histopathological studies showed complete cartilage regeneration and near normal joint in ETBE treated arthritic rats.

CONCLUSION

ETBE demonstrated potent anti-inflammatory activity by modulating the expression of inflammatory cytokines and restoring the antioxidant enzyme levels.

Principles of Information Storage in Small-Molecule Mixtures

Molecular data systems have the potential to store information at dramatically higher density than existing electronic media. Some of the first experimental demonstrations of this idea have used DNA, but nature also uses a wide diversity of smaller non-polymeric molecules to preserve, process, and transmit information. In this paper, we present a general framework for quantifying chemical memory, which is not limited to polymers and extends to mixtures of molecules of all types. We show that the theoretical limit for molecular information is two orders of magnitude denser by mass than DNA, although this comes with different practical constraints on total capacity. We experimentally demonstrate kilobyte-scale information storage in mixtures of small synthetic molecules, and we consider some of the new perspectives that will be necessary to harness the information capacity available from the vast non-genomic chemical space.

Multicomponent molecular memory

Multicomponent reactions enable the synthesis of large molecular libraries from relatively few inputs. This scalability has led to the broad adoption of these reactions by the pharmaceutical industry. Here, we employ the four-component Ugi reaction to demonstrate that multicomponent reactions can provide a basis for large-scale molecular data storage. Using this combinatorial chemistry we encode more than 1.8 million bits of art historical images, including a Cubist drawing by Picasso. Digital data is written using robotically synthesized libraries of Ugi products, and the files are read back using mass spectrometry. We combine sparse mixture mapping with supervised learning to achieve bit error rates as low as 0.11% for single reads, without library purification. In addition to improved scaling of non-biological molecular data storage, these demonstrations offer an information-centric perspective on the high-throughput synthesis and screening of small-molecule libraries.

Small non-polymeric molecules have tremendous structural diversity that can be used to represent information. Here the authors encode data in synthesized libraries of Ugi products.

[Pyogenic granuloma with satellitosis]

A 16-year-old female developed a satellite-like recurrence of a pyogenic granuloma on her thorax 2 weeks after complete excision. Treatment with a pulsed dye laser led to a complete resolution. BRAF and RAS mutations detected in the pyogenic granuloma are considered major driver mutations. Whether these findings are also of importance for the etiopathogenesis of satellitosis is unknown. In our patient, no BRAF or NRAS mutation could be detected.

[Granulomatous reaction pattern of the skin : Interstitial granulomatous dermatitis - lymphoma - vasculitis]

A particular diagnostic situation in the classification of a granulomatous dermatitis results when no circumscribed granulomas but instead a diffuse interstitial histiocytic inflammatory infiltrate, a granulomatous vasculitis or a neoplastic lymphocytic infiltrate is found. Interstitial granulomatous dermatitis was originally described in patients with arthritis. Later, it was recognized that there are also associations with other usually immunological diseases. Differentiating between interstitial granulomatous dermatitis and the interstitial form of granuloma annulare, early morphea and variants of borreliosis or scleromyxedema as well as interstitial granulomatous drug reaction can be very difficult. In long-standing cutaneous granulomatous infiltrates, T‑cell lymphoma should be excluded. Occasionally only a small number of atypical lymphocytes can be found. The detection of a monoclonal T‑cell expansion is then particularly helpful. Only recently, a CD8-positive granulomatous cutaneous T‑cell lymphoma was described which occurred in patients with immunodeficiencies. A granulomatous vasculitis in the skin is extremely rare. According to the Chapel Hill classification from 2012, systemic granulomatous vasculitis is equated with giant cell arteritis. Extracutaneous large arteries are involved. On rare occasions, involvement of the temporal artery can result in skin necrosis. More commonly granulomatous infiltrates in combination with vasculitis can be observed, whereby various infectious diseases, sarcoidosis and nodular vasculitis should be considered. Granulomatosis with polyangiitis (formerly Wegener's granulomatosis), presents in the skin as leukocytoclastic vasculitis. Here granulomas are extremely rare.

Encoding information in synthetic metabolomes

Biomolecular information systems offer exciting potential advantages and opportunities to complement conventional semiconductor technologies. Much attention has been paid to information-encoding polymers, but small molecules also play important roles in biochemical information systems. Downstream from DNA, the metabolome is an information-rich molecular system with diverse chemical dimensions which could be harnessed for information storage and processing. As a proof of principle of small-molecule postgenomic data storage, here we demonstrate a workflow for representing abstract data in synthetic mixtures of metabolites. Our approach leverages robotic liquid handling for writing digital information into chemical mixtures, and mass spectrometry for extracting the data. We present several kilobyte-scale image datasets stored in synthetic metabolomes, which can be decoded with accuracy exceeding 99% using multi-mass logistic regression. Cumulatively, >100,000 bits of digital image data was written into metabolomes. These early demonstrations provide insight into some of the benefits and limitations of small-molecule chemical information systems.

Lower serum adiponectin level is associated with lipodystrophy among HIV-infected men in the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN) study

OBJECTIVES

Adiponectin levels are inversely related to cardiovascular risk and are low in diabetics and obese persons. We examined the association between adiponectin concentration and HIV-associated lipodystrophy, which remains unclear.

METHODS

The Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN) was a prospective cohort study of HIV-infected adults conducted in four US cities. Lean body and fat masses were assessed using dual-energy X-ray absorptiometry scans. Using baseline data from 2004 to 2006, we defined lipodystrophy using a sex-specific fat mass ratio and performed cross-sectional analyses of associated risks using multivariable logistic regression.

RESULTS

Among 440 male participants (median age 42 years; 68% non-Hispanic white; 88% prescribed combination antiretroviral therapy; median CD4 lymphocyte count 468 cells/μL; 76% with viral load < 400 HIV-1 RNA copies/mL; 5% diabetic; median body mass index 25 kg/m² ), median concentrations of leptin and adiponectin were 3.04 ng/L [interquartile range (IQR) 1.77-5.43 ng/L] and 8005 μg/mL (IQR 4950-11 935 μg/mL), respectively. The prevalence of lipodystrophy was 14%. Lipodystrophy was significantly associated with increasing age [prevalence ratio (PR) 1.50; 95% confidence interval (CI) 1.10-2.06, per 10 years], adiponectin < 8005 μg/mL (PR 5.02; 95% CI 2.53-9.95), ever stavudine use (PR 2.26; 95% CI 1.36-3.75), CD4 cell count > 500 cells/μL (PR 2.59; 95% CI 1.46-4.61), viral load < 400 copies/mL (PR 3.98; 95% CI 1.25-12.6), highly sensitive C-reactive protein < 1.61 mg/L (PR 1.91; 95% CI 1.11-3.28) and smoking (PR 0.42; 95% CI 0.22-0.78).

CONCLUSIONS

Among men in this HIV-infected cohort, the prevalence of lipodystrophy was similar to previous estimates for persons living with HIV, and was associated with lower adiponectin levels, potentially indicating increased cardiovascular disease risk.

Abstract P2-08-26: High expression of CYP27A1 in breast cancer is associated with poor tumor pathological features and may differentially predict prognosis depending on menopausal status

Background: Pre-clinical and epidemiological data strongly link high cholesterol with breast cancer progression and poor prognosis. It was recently uncovered that the pathogenicity of cholesterol in breast cancer is directly propagated by 27-hydroxycholesterol (27HC), an oxysterol produced when cholesterol is hydroxylated by cytochrome P450, family 27, subfamily A, polypeptide 1 (CYP27A1) during bile acid synthesis. 27HC promotes breast tumor growth and metastasis via interactions with the estrogen receptor (ER) and liver x receptors respectively. Consequently, pharmaceutical approaches that directly interfere with CYP27A1 activity have been proposed to mitigate the adverse impact of 27HC in breast cancer. However, CYP27A1 expression or deregulation in clinical breast cancer is not well characterised. The aim of this study was to comprehensively describe the impact of tumor-specific expression of CYP27A1 protein on clinical breast cancer pathobiology and prognosis.

Methods: CYP27A1 expression in tumor cells was evaluated by immunohistochemistry in two independent population based cohorts including female patients with primary invasive breast cancer diagnosed between 1991 and 2010 (cohort 1) and between 2002 and 2012 (cohort 2). Staining was evaluable in 645 and 813 cases in cohort 1 and cohort 2, respectively. Associations between CYP27A1 expression with tumor pathological factors and survival were assessed by using logistic and Cox regression models respectively. Multivariable models adjusted for age at diagnosis, nodal status, histological grade, tumor size, ER and BMI.

Results: CYP27A1 was overexpressed in 21% and 28% in cohort 1 and cohort 2 respectively. High CYP27A1 expression was significantly associated with adverse tumor pathological features including negative hormone receptor (ER and PgR) status and histological grade 3 in both cohorts and with larger tumors (&gt;20 mm) in cohort two only (p&lt;0.05, for all comparisons). In multivariable Cox regression analyses, overexpression of CYP27A1 was neither independently prognostic for recurrence-free survival (cohort 2: HR=1.3, 95% CI= 0.88 – 1.9) nor overall survival (cohort 1: HR=1.3, 95% CI= 0.88 – 1.9 and Cohort 2: HR=1.3, 95% CI= 0.81 – 2.0, respectively). Upon stratification for menopausal status using age at diagnosis (&lt; 50 years vs ≥ 50 years) as surrogate, the relationship between CYP27A1 expression and prognosis remained non-significant for older (postmenopausal) patients. Interestingly, among younger (premenopausal) women, elevated CYP27A1 expression was independently prognostic for shorter time to recurrence or death (HR=3.3, 95% CI= 1.5 – 7.4; cohort 2).

Conclusions: Collectively, these results indicate that intratumoral CYP27A1 expression supports the notion that 27HC plays an important pathological role in breast cancer progression but tumor cell-specific CYP27A1 expression is not sufficient to independently predict overall survival in postmenopausal patients. Further sufficiently sized studies are needed to clarify the prognostic significance of CYP27A1 in younger and presumably premenopausal patients and evaluate its role as a treatment predictive factor.

Citation Format: Kimbung S, Stålhammar T, Inasu M, Nodin B, Elebro K, Tryggvadottir H, Jirström K, Rose C, Ingvar C, Jernström H, Borgquist S. High expression of CYP27A1 in breast cancer is associated with poor tumor pathological features and may differentially predict prognosis depending on menopausal status [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-26.

"Just too busy living in the moment and surviving": barriers to accessing health care for structurally vulnerable populations at end-of-life

BACKGROUND

Despite access to quality care at the end-of-life (EOL) being considered a human right, it is not equitable, with many facing significant barriers. Most research examines access to EOL care for homogenous 'normative' populations, and as a result, the experiences of those with differing social positioning remain unheard. For example, populations experiencing structural vulnerability, who are situated along the lower rungs of social hierarchies of power (e.g., poor, homeless) will have unique EOL care needs and face unique barriers when accessing care. However, little research examines these barriers for people experiencing life-limiting illnesses and structural vulnerabilities. The purpose of this study was to identify barriers to accessing care among structurally vulnerable people at EOL.

METHODS

Ethnography informed by the critical theoretical perspectives of equity and social justice was employed. This research drew on 30 months of ethnographic data collection (i.e., observations, interviews) with structurally vulnerable people, their support persons, and service providers. Three hundred hours of observation were conducted in homes, shelters, transitional housing units, community-based service centres, on the street, and at health care appointments. The constant comparative method was used with data collection and analysis occurring concurrently.

RESULTS

Five significant barriers to accessing care at EOL were identified, namely: (1) The survival imperative; (2) The normalization of dying; (3) The problem of identification; (4) Professional risk and safety management; and (5) The cracks of a 'silo-ed' care system. Together, findings unveil inequities in accessing care at EOL and emphasize how those who do not fit the 'normative' palliative-patient population type, for whom palliative care programs and policies are currently built, face significant access barriers.

CONCLUSIONS

Findings contribute a nuanced understanding of the needs of and barriers experienced by those who are both structurally vulnerable and facing a life-limiting illness. Such insights make visible gaps in service provision and provide information for service providers, and policy decision-makers alike, on ways to enhance the equitable provision of EOL care for all populations.

Dosimetric comparison of helical tomotherapy and VMAT for anal cancer: A single institutional experience

To compare the dosimetric results of helical tomotherapy (HT) and volumetric arc therapy (VMAT) in the treatment of anal cancer. Plans were created for 20 (n = 20) patients treated for anal cancer using HT and 2 arc VMAT. Dosimetric comparison was assessed for doses to targets and organs at risk (small bowel, bladder, external genitalia, and femoral heads). Delivery time and dosimetric verification results were also compared. HT showed a higher V95% for both primary and nodal targets (V95% increase by 0.5% to 1.3%; p = ≤0.05). No differences were seen in V105%, V107%, or V110 % between techniques. HT provided better sparing of the small bowel for dose levels V30, V35, and V40 (p = 0.005, 0.001, and 0.030), but was similar at higher doses. Similarly HT provided better bladder dose at V35 only (p = 0.020). Doses to femoral heads and genitalia were similar. Delivery time was higher for the HT plans (4.58 ± 1.1 min) than VMAT (3.13 ± 0.2 minutes) (p = 0.011). Dose verification results were 99.5 ± 0.9% and 100 ± 0% (HT, n = 6) vs 95.0 ± 3.1% and 99.2 ± 0.8% (VMAT, n = 20) for global gamma criteria 3%/3 mm and 4%/4 mm, respectively. Both HT and VMAT produced high quality plans that frequently met most of the dose objectives apart from genitalia V20, V40, bladder V35, and V50. Although absolute dose differences were small, the PTV V95%, small bowel V30, V35, and V40 and bladder V35 were statistically better in the HT plans. VMAT provided a shorter delivery time by 1.45 minutes; however, our HT plans were more likely to pass tighter plan dose verification criteria than VMAT.

Abstract 775: HIPStA, a high-throughput alternative to CETSA®

The measurement of drug - target interaction in the cellular context is critical to many drug development programs. The Cellular Thermal Stability Assay (CETSA®) represents an established broadly applicable method for measuring drug target interaction. However, in its classic format, it has some limitations that make it difficult to scale to the throughput typically required for a drug development project. It requires heating samples to different temperatures and centrifugation and / or filtration steps which limit throughput. The HSP90 Inhibitor Protein Stability Assay (HIPStA) is a novel method for measuring drug target interaction. Like CETSA®, HIPStA is based on the premise that the binding of a ligand to a target protein can influence that protein's stability. Instead of using heat to destabilize a protein, HIPStA uses a Heat Shock Protein 90 inhibitor (HSP90i) to cause protein instability. Instead of scanning a range of different temperatures to establish a thermal denaturation curve, HIPStA applies a range of concentrations of an HSP90i to determine an HSP90i induced denaturation curve, and ultimately measures the ability of a compound to stabilize a protein. We present data demonstrating the proof of concept for the HIPStA method, using 3 different classes of drug discovery targets: Receptor tyrosine kinases, Nuclear Hormone Receptors and Cytoplasmic Protein Kinases. HIPStA represents a scale-able method for detecting drug-target interaction in cells.

Citation Format: Kelvin F. Cho, Christopher Rose, Taylur Ma, Donald Kirkpatrick, Robert A. Blake. HIPStA, a high-throughput alternative to CETSA® [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 775.

Myosteatosis and sarcopenia are associated with hepatic encephalopathy in patients with cirrhosis

BACKGROUND

Skeletal muscle is known to play a role in hepatic encephalopathy. Fatty infiltration of the muscle (myosteatosis) and muscle mass depletion (sarcopenia) are frequent complications of cirrhosis.

PURPOSE

The purposes of the study were to investigate if myosteatosis and sarcopenia are associated with overt hepatic encephalopathy in patients with cirrhosis and to evaluate their impact on mortality.

METHODS

A total of 675 cirrhotic patients were studied. Computed tomography scans were used to analyze the skeletal muscle. Hepatic encephalopathy was defined by either a hepatic encephalopathy-related hospitalization and/or taking ammonia-lowering treatment (i.e., lactulose, rifaximin).

RESULTS

Myosteatosis was observed in 348 patients (52%), sarcopenia in 242 (36%), and hepatic encephalopathy in 128 (19%) patients. Both myosteatosis (70 vs. 45%, p < 0.001) and sarcopenia (53 vs. 32%, p < 0.001) were more frequent in patients with hepatic encephalopathy. By multivariable regression analysis, both myosteatosis and sarcopenia were associated with a higher risk of hepatic encephalopathy, independent of the MELD score (OR 2.25; 95% CI, 1.32-3.85, p = 0.003 and OR 2.42; 95% CI, 1.43-4.10, p = 0.001, respectively). In univariate Cox proportional hazards analysis, sarcopenia (csHR 2.02; 95% CI, 1.57-2.58, p < 0.001), myosteatosis (csHR 1.45; 95% CI, 1.16-2.91, p = 0.004), and hepatic encephalopathy (csHR 1.61; 95% CI, 1.20-2.18, p = 0.002) were associated with mortality, but only sarcopenia was significant in the multivariable analysis (csHR 2.15; 95% CI, 1.52-3.05, p < 0.001).

CONCLUSIONS

Myosteatosis and sarcopenia are independently associated with overt hepatic encephalopathy in patients with cirrhosis. The association between hepatic encephalopathy and mortality may be explained at least partially by the presence of sarcopenia. These results identify the importance of muscle mass and suggest therapeutic strategies to attenuate muscle mass loss and improve muscle quality.

A Dosimetric Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including the Internal Mammary Chain

AIMS

Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs).

MATERIALS AND METHODS

In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance.

RESULTS

One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P < 0.0001) and VMAT (P < 0.0001) techniques. There was no advantage in target volume coverage or OAR doses for PBT(vDIBH) compared with PBT(FB).

CONCLUSIONS

Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics.

Stenosis at the area of Transposition – An Under-Recognized Complication of Transposed Brachiobasilic Fistulas

Background

With an increased focus on native AV fistula creation in hemodialysis patients, a transposed brachiobasilic fistula (tBBF) is becoming an increasingly utilized option. This study describes the outcomes of tBBFs in a chronic hemodialysis population. In particular, we focus on the incidence and location of stenosis, and review the impact of angioplasty on these lesions.

Methods

A retrospective cohort study using all patients with a tBBF created between January 2001 and December 2004.

Results

Of the 543 fistulas created during the study period, 93 were tBBFs. The mean age of patients was 65 years, 56% were male and 55% were diabetic. Stenosis occurred in 54% (46/85) of fistulas; the location of stenosis in the majority (74%) was at or near the area of basilic vein transposition and 50% of fistulas with stenosis in this location required three or more angioplasties. Primary (unassisted) patency was 42% at one year in this cohort. Secondary patency was 68% at 1 year and 58% and 53% at 2 and 3 years respectively.

Conclusion

In a cohort of hemodialysis patients who received a tBBF, we describe a reasonable primary and secondary patency rate and a high rate of stenosis at the point of transposition of the basilic vein. Such stenosis usually requires multiple percutaneous or surgical interventions to ensure or reestablish conduit patency. Further study is required regarding the optimal surgical technique, monitoring, and treatment of stenosis of this fistula type including the utility of repeat angioplasty.

[Diagnostics of malignant melanoma of the skin : Recommendations of the current S3 guidelines on histology and molecular pathology]

The updated S3 guidelines on malignant melanoma were established in August 2016. The principles of diagnostics and classification are based on the histopathological results from the primary tumor and if necessary the sentinel lymph nodes. The most important factor for prognosis is the tumor thickness according to Breslow and the detection of sentinel node micrometastases. The surgical safety margin after excision is dependent on the tumor thickness. Furthermore, ulceration of the primary tumor and presence of mitosis in melanomas less than 1 mm in thickness are also considered in the T‑classification. The sentinel lymph nodes should be prepared according to established procedures using HE staining and immunohistochemical methods. The largest tumor diameter of a micrometastasis should be measured in tenths of a millimeter (Rotterdam classification). Molecular pathology testing for mutations in the BRAF and NRAS oncogenes should be carried out in patients with metastatic disease or surgically non-resectable tumors. In addition c-KIT mutations should be tested in acral lentiginous and mucosal melanomas. Treatment with signal transduction inhibitors is possible when mutations have been detected.

Developmental dysplasia of the hip: A computational biomechanical model of the path of least energy for closed reduction

This study utilized a computational biomechanical model and applied the least energy path principle to investigate two pathways for closed reduction of high grade infantile hip dislocation. The principle of least energy when applied to moving the femoral head from an initial to a final position considers all possible paths that connect them and identifies the path of least resistance. Clinical reports of severe hip dysplasia have concluded that reduction of the femoral head into the acetabulum may occur by a direct pathway over the posterior rim of the acetabulum when using the Pavlik harness, or by an indirect pathway with reduction through the acetabular notch when using the modified Hoffman-Daimler method. This computational study also compared the energy requirements for both pathways. The anatomical and muscular aspects of the model were derived using a combination of MRI and OpenSim data. Results of this study indicate that the path of least energy closely approximates the indirect pathway of the modified Hoffman-Daimler method. The direct pathway over the posterior rim of the acetabulum required more energy for reduction. This biomechanical analysis confirms the clinical observations of the two pathways for closed reduction of severe hip dysplasia. The path of least energy closely approximated the modified Hoffman-Daimler method. Further study of the modified Hoffman-Daimler method for reduction of severe hip dysplasia may be warranted based on this computational biomechanical analysis. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:1799-1805, 2017.

Reciprocity to Increase Participation of Compatible Living Donor and Recipient Pairs in Kidney Paired Donation

Inclusion of compatible living donor and recipient pairs (CPs) in kidney paired donation (KPD) programs could increase living donor transplantation. We introduce the concept of a reciprocity-based strategy in which the recipient of a CP who participates in KPD receives priority for a repeat deceased donor transplant in the event their primary living donor KPD transplant fails, and then we review the practical and ethical considerations of this strategy. The strategy limits prioritization to CPs already committed to living donation, minimizing the risk of unduly influencing donor behavior. The provision of a tangible benefit independent of the CP's actual KPD match avoids many of the practical and ethical challenges with strategies that rely on finding the CP recipient a better-matched kidney that might provide the CP recipient a future benefit to increase KPD participation. Specifically, the strategy avoids the potential to misrepresent the degree of future benefit of a better-matched kidney to the CP recipient and minimizes delays in transplantation related to finding a better-matched kidney. Preliminary estimates suggest the strategy has significant potential to increase the number of living donor transplants. Further evaluation of the acceptance of this strategy by CPs and by waitlisted patients is warranted.