Dehydrated human amnion/chorion membrane to treat venous leg ulcers: a cost-effectiveness analysis.

OBJECTIVE: To evaluate the cost-effectiveness of dehydrated human amnion/chorion membrane (DHACM) in Medicare enrolees who developed a venous leg ulcer (VLU). METHOD: This economic evaluation used a four-state Markov model to simulate the disease progression of VLUs for patients receiving advanced treatment (AT) with DHACM or no advanced treatment (NAT) over a three-year time horizon from a US Medicare perspective. DHACM treatments were assessed when following parameters for use (FPFU), whereby applications were initiated 30-45 days after the initial VLU diagnosis claim, and reapplications occurred on a weekly to biweekly basis until completion of the treatment episode. The cohort was modelled on the claims of 530,220 Medicare enrolees who developed a VLU between 2015-2019. Direct medical costs, quality-adjusted life years (QALYs), and the net monetary benefit (NMB) at a willingness-to-pay threshold of $100,000/QALY were applied. Univariate and probabilistic sensitivity analyses (PSA) were performed to test the uncertainty of model results. RESULTS: DHACM applied FPFU dominated NAT, yielding a lower per-patient cost of $170 and an increase of 0.010 QALYs over three years. The resulting NMB was $1178 per patient in favour of DHACM FPFU over the same time horizon. The rate of VLU recurrence had a notable impact on model uncertainty. In the PSA, DHACM FPFU was cost-effective in 63.01% of simulations at the $100,000/QALY threshold. CONCLUSION: In this analysis, DHACM FPFU was the dominant strategy compared to NAT, as it was cost-saving and generated a greater number of QALYs over three years from the US Medicare perspective. A companion VLU Medicare outcomes analysis revealed that patients who received AT with a cellular, acellular and matrix-like product (CAMP) compared to patients who received NAT had the best outcomes. Given the added clinical benefits to patients at lower cost, providers should recommend DHACM FPFU to patients with VLU who qualify. Decision-makers for public insurers (e.g., Medicare and Medicaid) and commercial payers should establish preferential formulary placement for reimbursement of DHACM to reduce budget impact and improve the long-term health of their patient populations dealing with these chronic wounds. DECLARATION OF INTEREST: Support for this analysis was provided by MiMedx Group, Inc., US. JLD, and RAF are employees of MiMedx Group, Inc. WHT, BH, PS, BGC and WVP were consultants to MiMedx Group, Inc. VD, AO, MRK, JAN, NW and GAM served on the MiMedx Group, Inc. Advisory Board. MRK and JAN served on a speaker's bureau. WVP declares personal fees and equity holdings from Stage Analytics, US.

Treatment patterns and outcomes of Medicare enrolees who developed venous leg ulcers.

OBJECTIVE: To retrospectively evaluate the comorbidities, treatment patterns and outcomes of Medicare enrolees who developed venous leg ulcers (VLUs). METHOD: Medicare Limited Data Standard Analytic Hospital Inpatient and Outpatient Department Files were used to follow patients who received medical care for a VLU between 1 October 2015 and 2 October 2019. Patients diagnosed with chronic venous insufficiency (CVI) and a VLU were propensity matched into four groups based on their treatment regimen. Episode claims were used to document demographics, comorbidities and treatments of Medicare enrolees who developed VLUs, as well as important outcomes, such as time to ulcer closure, rates of complications and hospital utilisation rates. Outcomes were compared across key propensity-matched groups. RESULTS: In total, 42% of Medicare enrolees with CVI (n=1,225,278), developed at least one VLU during the study, and 79% had their episode claim completed within one year. However, 59% of patients developed another VLU during the study period. This analysis shows that only 38.4% of VLU episodes received documented VLU conservative care treatment. Propensity-matched episodes that received an advanced treatment or high-cost skin substitutes for a wound which had not progressed by 30 days demonstrated the best outcomes when their cellular, acellular, matrix-like product (CAMP) treatment was applied weekly or biweekly (following parameters for use). Complications such as rates of infection (33%) and emergency department visits (>50%) decreased among patients who received an advanced treatment (following parameters for use). CONCLUSION: Medicare enrolees with CVI have diverse comorbidities and many do not receive sufficient management, which contributes to high rates of VLUs and subsequent complications. Medicare patients at risk of a VLU who receive early identification and advanced CAMP treatment demonstrated improved quality of life and significantly reduced healthcare resource utilisation.

Pyoderma gangrenosum and dehydrated human amnion/chorion membrane: a potential tool for an orphan disease.

OBJECTIVE: Pyoderma gangrenosum (PG) is an often-misdiagnosed, painful, inflammatory and ulcerative skin disorder. It is an orphan disease, where standard wound treatments such as sharp surgical debridement are contraindicated. This retrospective case series sought to evaluate the application of dehydrated human amnion/chorion membrane (DHACM) as a skin substitute in cases that were refractory to a range of standard-of-care techniques. METHOD: This retrospective case series involved wounds which failed to close with standard escalating treatments, including anti-inflammatory and immunosuppressive therapies. Subjects were transitioned to DHACM and wound sizes were monitored until closure. RESULTS: Wounds (n=5) for all three subjects had stalled with standard therapies for at least 2.5 months but responded quickly to routinely applied DHACM treatments, and closure was achieved in each case. CONCLUSION: This retrospective pilot case series examined the use of DHACM as an alternative wound treatment for PG patients failing standard therapies. DHACM treatments re-initiated the trajectory towards wound closure for each stalled PG ulcer. The results suggest a treatment algorithm starting with early recognition, wound closure via treatment escalation, and lastly a gradual reduction in treatment for durable closure. DHACM treatment should be formally evaluated as an adjunct to PG ulcers that have remained refractory to more commonly used immunomodulating therapies.

The influence of adequate debridement and placental-derived allografts on diabetic foot ulcers.

OBJECTIVE: To determine the role of debridement when patients are using placental-derived allografts (PDAs), data from two prospective, multicentre, randomised controlled trials (RCTs) were evaluated for the quality or adequacy of debridement on diabetic foot ulcers (DFUs) treated with PDAs. Results were compared with real-world findings via a retrospective analysis of 2015-2019 Medicare claims for DFUs. METHOD: Debridement adequacy in the prospective RCTs was adjudicated by three blinded wound care specialists. Treatments included two PDAs, dehydrated human amnion/chorion membrane (DHACM, n=54) or dehydrated human umbilical cord (DHUC, n=101), compared with standard of care (SOC, n=110). The key outcome was the influence of adequate debridement on rates of complete closure within 12 weeks. Additionally, a retrospective analysis of 2015-2019 Medicare claims for DFUs that received routine debridement at intervals ranging from every 1-7 days (18,900 total episodes), 8-14 days (35,728 total episodes), and every 15 days or greater (34,330 total episodes) was performed. RESULTS: Within the RCTs, adequate debridement occurred in 202/265 (76%) of patients, 90/110 (82%) SOC ulcers, 45/54 (83%) of DHACM-treated ulcers, and in 67/101 (66%) of DHUC-treated ulcers. Complete closure occurred in 150/202 (74%) of adequately debrided ulcers, and in only 13/63 (21%) of ulcers without adequate debridement, p<0.0001. Debridement was the most significant factor for closure even when controlling for other clinical characteristics. Within the Medicare claims data 21% (18,900/88,958) of episodes treated with SOC only had debridement intervals of ≤7 days. Short debridement intervals in combination with the use of DHACM demonstrated statistically significant better outcomes than SOC including: 65% fewer major amputations (p<0.0001), higher DFU resolution rates (p=0.0125), 42% fewer emergency room visits (p<0.0001) and reduced usage of other hospital resources (admissions and readmissions). CONCLUSION: Prospectively collected data examining the quality of debridement and retrospectively analysed data examining the frequency of debridement supports routine adequate wound debridement, particularly at intervals of seven days, as an essential component of wound care. Optimal use of placental-derived allografts improves outcomes and lowers the use of healthcare resources.

Cost-effectiveness of dehydrated human amnion/chorion membrane allografts in lower extremity diabetic ulcer treatment.

OBJECTIVE: To evaluate the cost-effectiveness and budget impact of using standard care (no advanced treatment, NAT) compared with an advanced treatment (AT), dehydrated human amnion/chorion membrane (DHACM), when following parameters for use (FPFU) in treating lower extremity diabetic ulcers (LEDUs). METHOD: We analysed a retrospective cohort of Medicare patients (2015-2019) to generate four propensity-matched cohorts of LEDU episodes. Outcomes for DHACM and NAT, such as amputations, and healthcare utilisation were tracked from claims codes, analysed and used to build a hybrid economic model, combining a one-year decision tree and a four-year Markov model. The budget impact was evaluated in the difference in per member per month spending following completion of the decision tree. Likewise, the cost-effectiveness was analysed before and after the Markov model at a willingness to pay (WTP) threshold of $100,000 per quality adjusted life year (QALY). The analysis was conducted from the healthcare sector perspective. RESULTS: There were 10,900,127 patients with a diagnosis of diabetes, of whom 1,213,614 had an LEDU. Propensity-matched Group 1 was generated from the 19,910 episodes that received AT. Only 9.2% of episodes were FPFU and DHACM was identified as the most widely used AT product among Medicare episodes. Propensity-matched Group 4 was limited by the 590 episodes that used DHACM FPFU. Episodes treated with DHACM FPFU had statistically fewer amputations and healthcare utilisation. In year one, DHACM FPFU provided an additional 0.013 QALYs, while saving $3,670 per patient. At a WTP of $100,000 per QALY, the five-year net monetary benefit was $5003. CONCLUSION: The findings of this study showed that DHACM FPFU reduced costs and improved clinical benefits compared with NAT for LEDU Medicare patients. DHACM FPFU provided better clinical outcomes than NAT by reducing major amputations, ED visits, inpatient admissions and readmissions. These clinical gains were achieved at a lower cost, in years 1-5, and were likely to be cost-effective at any WTP threshold. Adoption of best practices identified in this retrospective analysis is expected to generate clinically significant decreases in amputations and hospital utilisation while saving money.

Carbogen inhalation during non-convulsive status epilepticus: A quantitative exploratory analysis of EEG recordings.

OBJECTIVE: To quantify the effect of inhaled 5% carbon-dioxide/95% oxygen on EEG recordings from patients in non-convulsive status epilepticus (NCSE). METHODS: Five children of mixed aetiology in NCSE were given high flow of inhaled carbogen (5% carbon dioxide/95% oxygen) using a face mask for maximum 120s. EEG was recorded concurrently in all patients. The effects of inhaled carbogen on patient EEG recordings were investigated using band-power, functional connectivity and graph theory measures. Carbogen effect was quantified by measuring effect size (Cohen's d) between "before", "during" and "after" carbogen delivery states. RESULTS: Carbogen's apparent effect on EEG band-power and network metrics across all patients for "before-during" and "before-after" inhalation comparisons was inconsistent across the five patients. CONCLUSION: The changes in different measures suggest a potentially non-homogeneous effect of carbogen on the patients' EEG. Different aetiology and duration of the inhalation may underlie these non-homogeneous effects. Tuning the carbogen parameters (such as ratio between CO2 and O2, duration of inhalation) on a personalised basis may improve seizure suppression in future.

Directly Sequenced Genomes of Contemporary Strains of Syphilis Reveal Recombination-Driven Diversity in Genes Encoding Predicted Surface-Exposed Antigens.

Syphilis, caused by Treponema pallidum subsp. pallidum (TPA), remains an important public health problem with an increasing worldwide prevalence. Despite recent advances in in vitro cultivation, genetic variability of this pathogen during infection is poorly understood. Here, we present contemporary and geographically diverse complete treponemal genome sequences isolated directly from patients using a methyl-directed enrichment prior to sequencing. This approach reveals that approximately 50% of the genetic diversity found in TPA is driven by inter- and/or intra-strain recombination events, particularly in strains belonging to one of the defined genetic groups of syphilis treponemes: Nichols-like strains. Recombinant loci were found to encode putative outer-membrane proteins and the recombination variability was almost exclusively found in regions predicted to be at the host-pathogen interface. Genetic recombination has been considered to be a rare event in treponemes, yet our study unexpectedly showed that it occurs at a significant level and may have important impacts in the biology of this pathogen, especially as these events occur primarily in the outer membrane proteins. This study reveals the existence of strains with different repertoires of surface-exposed antigens circulating in the current human population, which should be taken into account during syphilis vaccine development.

Controlled dissolution of freeform 3D printed carbohydrate glass scaffolds in hydrogels using a hydrophobic spray coating.

Freeform 3D printing combined with sacrificial molding promises to lead advances in production of highly complex tubular systems for biomedical applications. Here we leverage a purpose-built isomalt 3D printer to generate complex channel geometries in hydrogels which would be inaccessible with other techniques. To control the dissolution of the scaffold, we propose an enabling technology consisting of an automated nebulizer coating system which applies octadecane to isomalt scaffolds. Octadecane, a saturated hydrocarbon, protects the rigid mold from dissolution and provides ample time for gels to set around the sacrificial structure. With a simplified model of the nebulizer system, the robotic motion was optimized for uniform coating. Using a combination of stimulated Raman scattering (SRS) microscopy and X-ray computed tomography, the coating was characterized to assess surface roughness and consistency. Colorimetric measurements of dissolution rates allowed optimization of sprayer parameters, yielding a decrease in dissolution rates by at least 4 orders of magnitude. High fidelity channels are ensured by surfactant treatment of the coating, which prevents bubbles from clinging to the surface. Spontaneous Raman scattering microspectroscopy and white light microscopy indicate cleared channels are free of octadecane following gentle flushing. The capabilities of the workflow are highlighted with several complex channel architectures including helices, blind channels, and multiple independent channels within polyacrylamide hydrogels of varying stiffnesses.

Central diabetes insipidus: beware of Langerhans cell histiocytosis!

Langerhans cell histiocytosis (LCH) is a rare disorder, characterised by a monoclonal proliferation of aberrant histiocytes that accumulate in and infiltrate into different organs. When the hypothalamic-pituitary axis is involved, central diabetes insipidus (CDI) can be its first manifestation. Three cases of LCH with central diabetes insipidus were retrospectively analyzed: Case 1 is a 41-year old female presenting with polyuria and polydipsia. Diabetes insipidus was diagnosed and treated with desmopressin. MRI pituitary showed hypophysitis. Subsequently, she developed bone lesions and a biopsy demonstrated LCH. Case 2 is a 51-year old female presenting in 2009 with polyuria and polydipsia. Diabetes insipidus was diagnosed and treated with desmopressin. MRI pituitary revealed hypophysitis. LCH was suspected because of known pulmonary histiocytosis. Coexisting bone lesions were biopsied and confirmed LCH. Case 3 is a 44-year old female presenting with diabetes insipidus. She was treated with desmopressin as well. MRI of the pituitary gland showed impressive thickening of the infundibulum. A few months later, she developed skin lesions and a biopsy revealed LCH. Conclusively, LCH is a rare, elusive and probably underdiagnosed disease with a broad disease spectrum. Due to infiltration of the hypothalamic-pituitary axis, CDI can be the first manifestation, even before LCH is diagnosed. Therefore, LCH should be considered in the diagnostic workup of CDI.

[A new case of pityriasis rubra pilaris-like eruption associated with ponatinib, a tyrosine kinase inhibitor]. / Un nouveau cas d'éruption de type pityriasis rubra pilaire associée à l'inhibiteur de tyrosine kinase ponatinib.

BACKGROUND: Pityriasis rubra pilaris (PRP) is a cutaneous syndrome of unknown origin. Most cases are sporadic and acquired. Herein we report a fifth case of PRP-like eruption associated with ponatinib, a tyrosine kinase inhibitor (TKI). PATIENTS AND METHODS: A 60-year-old woman presented at the dermatology department with an erythemato-squamous eruption present for 2weeks. The patient was also being treated in haematology for recurrence of acute lymphoblastic leukaemia. Treatment with ponatinib had been initiated 6weeks earlier. Despite the low specific cutaneous histology, a diagnosis of induced PRP-like eruption was made based on the characteristic clinical aspect. Treatment with local corticosteroids resolved the eruption. DISCUSSION: The literature contains 6 reported cases of PRP-like eruptions associated with TKI, including 4 with ponatinib. The eruption began from 2weeks to 2-3 months after treatment induction. Prescribed topical corticosteroids have yielded mixed results. A better understanding of the physiopathology of these eruptions associated with TKI could shed light on the pathogenic mechanisms in relation to idiopathic PRP.

Correlation of ICME Magnetic Fields at Radially Aligned Spacecraft.

The magnetic field structures of two interplanetary coronal mass ejections (ICMEs), each observed by a pair of spacecraft close to radial alignment, have been analysed. The ICMEs were observed in situ by MESSENGER and STEREO-B in November 2010 and November 2011, while the spacecraft were separated by more than 0.6 AU in heliocentric distance, less than 4° in heliographic longitude, and less than 7° in heliographic latitude. Both ICMEs took approximately two days to travel between the spacecraft. The ICME magnetic field profiles observed at MESSENGER have been mapped to the heliocentric distance of STEREO-B and compared directly to the profiles observed by STEREO-B. Figures that result from this mapping allow for easy qualitative assessment of similarity in the profiles. Macroscale features in the profiles that varied on timescales of one hour, and which corresponded to the underlying flux rope structure of the ICMEs, were well correlated in the solar east-west and north-south directed components, with Pearson's correlation coefficients of approximately 0.85 and 0.95, respectively; microscale features with timescales of one minute were uncorrelated. Overall correlation values in the profiles of one ICME were increased when an apparent change in the flux rope axis direction between the observing spacecraft was taken into account. The high degree of similarity seen in the magnetic field profiles may be interpreted in two ways. If the spacecraft sampled the same region of each ICME (i.e. if the spacecraft angular separations are neglected), the similarity indicates that there was little evolution in the underlying structure of the sampled region during propagation. Alternatively, if the spacecraft observed different, nearby regions within the ICMEs, it indicates that there was spatial homogeneity across those different regions. The field structure similarity observed in these ICMEs points to the value of placing in situ space weather monitors well upstream of the Earth.

Modeling observations of solar coronal mass ejections with heliospheric imagers verified with the Heliophysics System Observatory.

We present an advance toward accurately predicting the arrivals of coronal mass ejections (CMEs) at the terrestrial planets, including Earth. For the first time, we are able to assess a CME prediction model using data over two thirds of a solar cycle of observations with the Heliophysics System Observatory. We validate modeling results of 1337 CMEs observed with the Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years of observations by five in situ observing spacecraft. We use the self-similar expansion model for CME fronts assuming 60° longitudinal width, constant speed, and constant propagation direction. With these assumptions we find that 23%-35% of all CMEs that were predicted to hit a certain spacecraft lead to clear in situ signatures, so that for one correct prediction, two to three false alarms would have been issued. In addition, we find that the prediction accuracy does not degrade with the HI longitudinal separation from Earth. Predicted arrival times are on average within 2.6 ± 16.6 h difference of the in situ arrival time, similar to analytical and numerical modeling, and a true skill statistic of 0.21. We also discuss various factors that may improve the accuracy of space weather forecasting using wide-angle heliospheric imager observations. These results form a first-order approximated baseline of the prediction accuracy that is possible with HI and other methods used for data by an operational space weather mission at the Sun-Earth L5 point.

Correction: Longitudinal Metagenomic Analysis of Hospital Air Identifies Clinically Relevant Microbes.

[This corrects the article DOI: 10.1371/journal.pone.0160124.].

Longitudinal Metagenomic Analysis of Hospital Air Identifies Clinically Relevant Microbes.

We describe the sampling of sixty-three uncultured hospital air samples collected over a six-month period and analysis using shotgun metagenomic sequencing. Our primary goals were to determine the longitudinal metagenomic variability of this environment, identify and characterize genomes of potential pathogens and determine whether they are atypical to the hospital airborne metagenome. Air samples were collected from eight locations which included patient wards, the main lobby and outside. The resulting DNA libraries produced 972 million sequences representing 51 gigabases. Hierarchical clustering of samples by the most abundant 50 microbial orders generated three major nodes which primarily clustered by type of location. Because the indoor locations were longitudinally consistent, episodic relative increases in microbial genomic signatures related to the opportunistic pathogens Aspergillus, Penicillium and Stenotrophomonas were identified as outliers at specific locations. Further analysis of microbial reads specific for Stenotrophomonas maltophilia indicated homology to a sequenced multi-drug resistant clinical strain and we observed broad sequence coverage of resistance genes. We demonstrate that a shotgun metagenomic sequencing approach can be used to characterize the resistance determinants of pathogen genomes that are uncharacteristic for an otherwise consistent hospital air microbial metagenomic profile.

Epigenetic Segregation of Microbial Genomes from Complex Samples Using Restriction Endonucleases HpaII and McrB.

We describe continuing work to develop restriction endonucleases as tools to enrich targeted genomes of interest from diverse populations. Two approaches were developed in parallel to segregate genomic DNA based on cytosine methylation. First, the methyl-sensitive endonuclease HpaII was used to bind non-CG methylated DNA. Second, a truncated fragment of McrB was used to bind CpG methylated DNA. Enrichment levels of microbial genomes can exceed 100-fold with HpaII allowing improved genomic detection and coverage of otherwise trace microbial genomes from sputum. Additionally, we observe interesting enrichment results that correlate with the methylation states not only of bacteria, but of fungi, viruses, a protist and plants. The methods presented here offer promise for testing biological samples for pathogens and global analysis of population methylomes.

Unbalanced Peptidergic Inhibition in Superficial Neocortex Underlies Spike and Wave Seizure Activity.

Slow spike and wave discharges (0.5-4 Hz) are a feature of many epilepsies. They are linked to pathology of the thalamocortical axis and a thalamic mechanism has been elegantly described. Here we present evidence for a separate generator in local circuits of associational areas of neocortex manifest from a background, sleep-associated delta rhythm in rat. Loss of tonic neuromodulatory excitation, mediated by nicotinic acetylcholine or serotonin (5HT3A) receptors, of 5HT3-immunopositive interneurons caused an increase in amplitude and slowing of the delta rhythm until each period became the "wave" component of the spike and wave discharge. As with the normal delta rhythm, the wave of a spike and wave discharge originated in cortical layer 5. In contrast, the "spike" component of the spike and wave discharge originated from a relative failure of fast inhibition in layers 2/3-switching pyramidal cell action potential outputs from single, sparse spiking during delta rhythms to brief, intense burst spiking, phase-locked to the field spike. The mechanisms underlying this loss of superficial layer fast inhibition, and a concomitant increase in slow inhibition, appeared to be precipitated by a loss of neuropeptide Y (NPY)-mediated local circuit inhibition and a subsequent increase in vasoactive intestinal peptide (VIP)-mediated disinhibition. Blockade of NPY Y1 receptors was sufficient to generate spike and wave discharges, whereas blockade of VIP receptors almost completely abolished this form of epileptiform activity. These data suggest that aberrant, activity-dependent neuropeptide corelease can have catastrophic effects on neocortical dynamics.

Selective microbial genomic DNA isolation using restriction endonucleases.

To improve the metagenomic analysis of complex microbiomes, we have repurposed restriction endonucleases as methyl specific DNA binding proteins. As an example, we use DpnI immobilized on magnetic beads. The ten minute extraction technique allows specific binding of genomes containing the DpnI Gm6ATC motif common in the genomic DNA of many bacteria including γ-proteobacteria. Using synthetic genome mixtures, we demonstrate 80% recovery of Escherichia coli genomic DNA even when only femtogram quantities are spiked into 10 µg of human DNA background. Binding is very specific with less than 0.5% of human DNA bound. Next Generation Sequencing of input and enriched synthetic mixtures results in over 100-fold enrichment of target genomes relative to human and plant DNA. We also show comparable enrichment when sequencing complex microbiomes such as those from creek water and human saliva. The technique can be broadened to other restriction enzymes allowing for the selective enrichment of trace and unculturable organisms from complex microbiomes and the stratification of organisms according to restriction enzyme enrichment.