bluuebunny/crossref_metadata_2025 huggingface dataset:
The theory of cosmic ray scattering on pre-existing MHD modes meets data
Authors: Fornieri Ottavio , Gaggero Daniele , Cerri Silvio Sergio , De La Torre Luque Pedro , Gabici Stefano
Published: February 2021

We present a comprehensive study about the phenomenological implications of the theory describing Galactic cosmic ray scattering on to magnetosonic and Alfvénic fluctuations in the GeV−PeV domain. We compute a set of diffusion coefficients from first principles, for different values of the Alfvénic Mach number and other relevant parameters associated with both the Galactic halo and the extended disc, taking into account the different damping mechanisms of turbulent fluctuations acting in these environments. We confirm that the scattering rate associated with Alfvénic turbulence is highly suppressed if the anisotropy of the cascade is taken into account. On the other hand, we highlight that magnetosonic modes play a dominant role in Galactic confinement of cosmic rays up to PeV energies. We implement the diffusion coefficients in the numerical framework of the dragon code, and simulate the equilibrium spectrum of different primary and secondary cosmic ray species. We show that, for reasonable choices of the parameters under consideration, all primary and secondary fluxes at high energy (above a rigidity of $\simeq 200 \, \mathrm{GV}$) are correctly reproduced within our framework, in both normalization and slope.
Dust evolution in zoom-in cosmological simulations of galaxy formation
Authors: Granato Gian Luigi , Ragone-Figueroa Cinthia , Taverna Antonela , Silva Laura , Valentini Milena , Borgani Stefano , Monaco Pierluigi , Murante Giuseppe , Tornatore Luca
Published: February 2021

We present cosmological zoom-in hydrodynamical simulations for the formation of disc galaxies, implementing dust evolution and dust promoted cooling of hot gas. We couple an improved version of our previous treatment of dust evolution, which adopts the two-size approximation to estimate the grain-size distribution, with the MUPPI star formation and feedback subresolution model. Our dust evolution model follows carbon and silicate dust separately. To distinguish differences induced by the chaotic behaviour of simulations from those genuinely due to different simulation set-up, we run each model six times, after introducing tiny perturbations in the initial conditions. With this method, we discuss the role of various dust-related physical processes and the effect of a few possible approximations adopted in the literature. Metal depletion and dust cooling affect the evolution of the system, causing substantial variations in its stellar, gas, and dust content. We discuss possible effects on the Spectral Energy Distribution of the significant variations of the size distribution and chemical composition of grains, as predicted by our simulations during the evolution of the galaxy. We compare dust surface density, dust-to-gas ratio, and small-to-large grain mass ratio as a function of galaxy radius and gas metallicity predicted by our fiducial run with recent observational estimates for three disc galaxies of different masses. The general agreement is good, in particular taking into account that we have not adjusted our model for this purpose.
The kinematic richness of star clusters – II. Stability of spherical anisotropic models with rotation
Authors: Breen Philip G , Rozier Simon , Heggie Douglas C , Varri Anna Lisa
Published: February 2021

We study the bar instability in collisionless, rotating, anisotropic, stellar systems, using N-body simulations and also the matrix technique for calculation of modes with the perturbed collisionless Boltzmann equation. These methods are applied to spherical systems with an initial Plummer density distribution, but modified kinematically in two ways: the velocity distribution is tangentially anisotropic, using results of Dejonghe, and the system is set in rotation by reversing the velocities of a fraction of stars in various regions of phase space, à la Lynden-Bell. The aim of the N-body simulations is first to survey the parameter space, and, using those results, to identify regions of phase space (by radius and orbital inclination) that have the most important influence on the bar instability. The matrix method is then used to identify the resonant interactions in the system that have the greatest effect on the growth rate of a bar. Complementary series of N-body simulations examine these processes in relation to the evolving frequency distribution and the pattern speed. Finally, the results are synthesized with an existing theoretical framework, and used to consider the old question of constructing a stability criterion.
Where is the genusElysiain the western Atlantic? Potential distribution, species richness and representation in marine protected areas
Authors: Jiménez Lina Marcela , Simões Nuno , Yáñez-Arenas Carlos
Published: February 2021

The western Atlantic Ocean is one of the areas with the largest species richness of sea slugs in the genus Elysia (30 out of the 101 species described have been reported in this region). Nevertheless, the lack of knowledge on many of these species hinders efforts to estimate regional richness and identify the factors affecting their distribution. We used the maximum entropy algorithm Maxent to develop ecological niche models for 14 species of Elysia in the western Atlantic Ocean. These models were meant to show the potential distribution of the genus and identify locations with the highest richness. Input data used to build niche models were presence records (obtained from several sources) and bioclimatic and geophysical variables from the Bio-ORACLE and MARSPEC platforms. Species with less than seven records were considered for the calculation of richness, but not for modelling. Results show low habitat suitability for the species modelled here at the mouth of rivers and in hypoxic zones and low-temperature areas. The two variables that best explained species distribution patterns were the distance to shore and the maximum monthly temperature. From the total area with adequate environmental conditions for the genus, only 20.3% is located within marine areas under some protection category.
Heterogeneity of Recent Phase 3 Complicated Urinary Tract Infection Clinical Trials
Authors: Portsmouth Simon , Bass Almasa , Echols Roger , Tillotson Glenn
Published: February 2021

Background

For new antibiotics developed to treat antibiotic-resistant Gram-negative infections, the US Food and Drug Administration (FDA) regulatory pathway includes complicated urinary tract infection (cUTI) clinical trials in which the clinical isolates are susceptible to the active control. This allows for inferential testing in a noninferiority study design. Although complying with regulatory guidelines, individual clinical trials may differ substantially in design and patient population. To determine variables that impacted patient selection and outcome parameters, 6 recent cUTI trials that were pivotal to an new drug application (NDA) submission were reviewed.

Methods

This selective descriptive analysis utilized cUTI trial data, obtained from publicly disclosed information including FDA documents and peer-reviewed publications, from 6 new antibiotics developed to treat multidrug-resistant Gram-negative infections: ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam, cefiderocol, plazomicin, and fosfomycin. Eravacycline was not approved for cUTI and is not included.

Results

Microbiologic modified intent-to-treat sample size, age, proportions of female patients, acute pyelonephritis (AP), Escherichia coli and other pathogens at baseline, protocol-specified switch to oral antibiotic, and the noninferiority margin were compared. Outcome data included clinical response, microbiologic eradication, and composite outcomes, including a subset of patients with AP.

Conclusions

A study design can follow regulatory guidelines but still have variable populations. The proportion of AP within a study varied greatly and influenced population demographics (age, gender) and baseline microbiology. A smaller proportion of AP resulted in an older patient population, fewer females, less E coli, and lower proportions of patients achieving success. Fluoroquinolones and piperacillin/tazobactam should be reconsidered as active comparators given the high rates of resistance to these antibiotics.
Disentangling the Coronavirus Disease 2019 Health Disparities in African Americans: Biological, Environmental, and Social Factors
Authors: Saini Geetanjali , Swahn Monica H , Aneja Ritu
Published: February 2021

The stark racial disparities related to the coronavirus disease 2019 (COVID-19) pandemic in the United States, wherein minority populations are disproportionately getting infected and succumbing to the disease, is of grave concern. It is critical to understand and address the underlying causes of these disparities that are complex and driven by interacting environmental, social and biological factors. In this article we focus on the African American community and examine how social and environmental determinants of health intersect with biological factors (comorbidities, underlying genetics, host immunity, vitamin D levels, epigenetics) to exacerbate risk for morbidity and mortality.
Relative Frequency and Risk Factors of COVID-19 Related Headache in a Sample of Egyptian Population: A Hospital-Based Study
Authors: Hussein Mona , Fathy Wael , Eid Ragaey A , Abdel-Hamid Hoda M , Yehia Ahmed , Sheemy Mostafa S , Ragaie Christine , Dahshan Ahmed , Rizk Hoda I , laz Nabila , Magdy Rehab
Published: February 2021

Objectives

Headache is considered one of the most frequent neurological manifestations of coronavirus disease 2019 (COVID-19). This work aimed to identify the relative frequency of COVID-19-related headache and to clarify the impact of clinical, laboratory findings of COVID-19 infection on headache occurrence and its response to analgesics.

Design

Cross-sectional study.

Setting

Recovered COVID-19 patients.

Subjects

In total, 782 patients with a confirmed diagnosis of COVID-19 infection.

Methods

Clinical, laboratory, and imaging data were obtained from the hospital medical records. Regarding patients who developed COVID-19 related headache, a trained neurologist performed an analysis of headache and its response to analgesics.

Results

The relative frequency of COVID-19 related headache among our sample was 55.1% with 95% confidence interval (CI) (.516–.586) for the estimated population prevalence. Female gender, malignancy, primary headache, fever, dehydration, lower levels of hemoglobin and platelets and higher levels of neutrophil/lymphocyte ratio (NLR) and CRP were significantly associated with COVID-19 related headache. Multivariate analysis revealed that female gender, fever, dehydration, primary headache, high NLR, and decreased platelet count were independent predictors of headache occurrence. By evaluating headache response to analgesics, old age, diabetes, hypertension, primary headache, severe COVID-19, steroid intake, higher CRP and ferritin and lower hemoglobin levels were associated with poor response to analgesics. Multivariate analysis revealed that primary headache, steroids intake, moderate and severe COVID-19 were independent predictors of non-response to analgesics.

Discussion

Headache occurs in 55.1% of patients with COVID-19. Female gender, fever, dehydration, primary headache, high NLR, and decreased platelet count are considered independent predictors of COVID-19 related headache.
The Effectiveness of Intraosseous Basivertebral Nerve Radiofrequency Neurotomy for the Treatment of Chronic Low Back Pain in Patients with Modic Changes: A Systematic Review
Authors: Conger Aaron , Schuster Nathaniel M , Cheng David S , Sperry Beau P , Joshi Anand B , Haring R Sterling , Duszynski Belinda , McCormick Zachary L
Published: February 2021

Objective

Determine the effectiveness of intraosseous basivertebral nerve radiofrequency neurotomy for the treatment of chronic low back pain with type 1 or 2 Modic changes.

Design

Systematic review.

Population

Persons aged ≥18 years with chronic low back pain with type 1 or 2 Modic changes.

Intervention

Intraosseous basivertebral nerve radiofrequency neurotomy

Comparison

Sham, placebo procedure, active standard care treatment, or none.

Outcomes

The primary outcome of interest was the proportion of individuals with ≥50% pain reduction. Secondary outcomes included ≥10-point improvement in function as measured by Oswestry Disability Index as well as ≥2-point reduction in pain score on the Visual Analog Scale or Numeric Rating Scale, and decreased use of pain medication.

Methods

Three reviewers independently assessed publications before May 15, 2020, in MEDLINE and Embase and the quality of evidence was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation framework.

Results

Of the 725 publications screened, seven publications with 321 participants were ultimately included. The reported 3-month success rate for ≥50% pain reduction ranged from 45% to 63%. Rates of functional improvement (≥10-point Oswestry Disability Index improvement threshold) ranged from 75% to 93%. For comparison to sham treatment, the relative risk of treatment success defined by ≥50% pain reduction and ≥10-point Oswestry Disability Index improvement was 1.25 (95% confidence interval [CI]: .88—1.77) and 1.38 (95% CI: 1.10—1.73), respectively. For comparison to continued standard care treatment the relative risk of treatment success defined by ≥50% pain reduction and ≥10-point Oswestry Disability Index improvement was 4.16 (95% CI: 2.12–8.14) and 2.32 (95% CI: 1.52–3.55), respectively.

Conclusions

There is moderate-quality evidence that suggests this procedure is effective in reducing pain and disability in patients with chronic low back pain who are selected based on type 1 or 2 Modic changes, among other inclusion and exclusion criteria used in the published literature to date. Success of the procedure appears to be dependent on effective targeting of the BVN. Non-industry funded high-quality, large prospective studies are needed to confirm these findings.
Opioid Prescribing Among Outpatients with Rheumatoid Arthritis
Authors: Huang Yinan , Rege Sanika , Chatterjee Satabdi , Aparasu Rajender R
Published: February 2021

Study Objectives

To examine the outpatient opioid prescribing practices and the factors associated with opioid prescriptions in patient visits with rheumatoid arthritis (RA).

Design

This cross-sectional study used the 2011–2016 National Ambulatory Medical Care Survey. Descriptive weighted analyses were used to examine the trends in opioid prescribing practices for RA. Multivariable logistic regression was used to examine the factors associated with opioid prescriptions among RA visits.

Subjects

Adult patients (>18 years of age) with a primary diagnosis of RA based on the International Classification of Diseases.

Results

According to the national surveys, an average of 4.45 (95% confidence interval [CI], 2.30–6.60) million office visits were made annually for RA. Approximately 24.28% of these visits involved opioid prescriptions. The RA visits involving opioid prescriptions increased from 1.43 million in 2011–2012 to 3.69 million in 2015–2016 (P < .0001). Being in the age group of 50–64 years (odds ratio [OR] = 3.40; 95% CI, 1.29–9.00), being Hispanic or Latino (OR = 2.92, 95% CI, 1.10–7.74), visiting primary physician (OR = 4.67; 95% CI, 1.86–11.75), prescribing of muscle relaxants (OR = 64.32; 95% CI, 9.71–426.09), acetaminophen (OR = 93.40; 95% CI, 26.19–333.04), antidepressants (OR = 6.10; 95% CI, 2.63–14.14), and glucocorticoids (OR = 3.20; 95% CI, 1.61–6.38), were associated with an increased likelihood of receiving opioid prescriptions in RA.

Conclusions

One in four adult RA visits resulted in opioid prescriptions, and the opioid visits more than doubled during the study period. Several patient and provider factors were associated with the opioid prescribing among RA visits. Understanding these prescribing practices can help to devise strategies for safe opioid prescribing practices in RA.
Paresthesia Predicts Increased Risk of Distal Neuropathic Pain in Older People with HIV-Associated Sensory Polyneuropathy
Authors: Diaz Monica M , Keltner John R , Simmons Alan N , Franklin Donald , Moore Raeanne C , Clifford David , Collier Ann C , Gelman Benjamin B , Marra Ph D , Christina , McCutchan J Allen , Morgello Susan , Sacktor Ned , Best Brookie , Notestine Christine Fennema , Weibel Sara Gianella , Grant Igor , Marcotte Thomas D , Vaida Florin , Letendre Scott , Heaton Robert , Ellis Ronald J
Published: February 2021

Objective

Distal sensory polyneuropathy (DSP) is a disabling consequence of human immunodeficiency virus (HIV), leading to poor quality of life and more frequent falls in older age. Neuropathic pain and paresthesia are prevalent symptoms; however, there are currently no known curative treatments and the longitudinal course of pain in HIV-associated DSP is poorly characterized.

Methods

This was a prospective longitudinal study of 265 people with HIV (PWH) enrolled in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study with baseline and 12-year follow-up evaluations. Since pain and paresthesia are highly correlated, statistical decomposition was used to separate the two symptoms at baseline. Multivariable logistic regression analyses of decomposed variables were used to determine the effects of neuropathy symptoms at baseline on presence and worsening of distal neuropathic pain at 12-year follow-up, adjusted for covariates.

Results

Mean age was 56 ± 8 years, and 21% were female at follow-up. Nearly the entire cohort (96%) was on antiretroviral therapy (ART), and 82% had suppressed (≤50 copies/mL) plasma viral loads at follow-up. Of those with pain at follow-up (n = 100), 23% had paresthesia at the initial visit. Decomposed paresthesia at baseline increased the risk of pain at follow-up (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.18, 2.07), and decomposed pain at baseline predicted a higher frequency of pain at follow-up (OR 1.96 [95% CI 1.51, 2.58]).

Conclusions

Paresthesias are a clinically significant predictor of incident pain at follow-up among aging PWH with DSP. Development of new therapies to encourage neuroregeneration might take advantage of this finding to choose individuals likely to benefit from treatment preventing incident pain.
Specialized, Pro-Resolving Mediators as Potential Therapeutic Agents for Alleviating Fibromyalgia Symptomatology
Authors: Livshits Gregory , Kalinkovich Alexander
Published: February 2021

Objective

To present a hypothesis on a novel strategy in the treatment of fibromyalgia (FM).

Design

A narrative review.

Setting

FM as a disease remains a challenging concept for numerous reasons, including undefined etiopathogenesis, unclear triggers, and unsuccessful treatment modalities. We hypothesize that the inflammatome, the entire set of molecules involved in inflammation, acting as a common pathophysiological instrument of gut dysbiosis, sarcopenia, and neuroinflammation, is one of the major mechanisms underlying FM pathogenesis. In this setup, dysbiosis is proposed as the primary trigger of the inflammatome, sarcopenia as the peripheral nociceptive source, and neuroinflammation as the central mechanism of pain sensitization, transmission, and symptomatology of FM. Whereas neuroinflammation is highly considered as a critical deleterious element in FM pathogenesis, the presumed pathogenic roles of sarcopenia and systemic inflammation remain controversial. Nevertheless, sarcopenia-associated processes and dysbiosis have been recently detected in individuals with FM. The prevalence of pro-inflammatory factors in the cerebrospinal fluid and blood has been repeatedly observed in individuals with FM, which supports the idea of a role of the inflammatome in FM pathogenesis. As such, failed inflammation resolution might be one of the underlying pathogenic mechanisms. Accordingly, the application of specialized, inflammation pro-resolving mediators (SPMs) seems most suitable for this goal.

Conclusions

The capability of various SPMs to prevent and attenuate pain has been repeatedly demonstrated in laboratory animal experiments. As SPMs suppress inflammation in a manner that does not compromise host defense, they could be attractive and safe candidates for the alleviation of FM symptomatology, probably in combination with anti-dysbiotic medicine.
Sensory Innervation of the Hip Joint and Referred Pain: A Systematic Review of the Literature
Authors: Laumonerie Pierre , Dalmas Yoann , Tibbo Meagan E , Robert Suzanne , Durant Thibault , Caste Thomas , Vialla Tristan , Tiercelin Joris , Gracia Gauthier , Chaynes Patrick
Published: February 2021

Objectives

The aim of this literature review was to establish consensus with respect to the anatomic features of the articular branches innervating the hip joint and the distribution of sensory receptors within its capsule.

Methods

Five electronic databases were queried, with the search encompassing articles published between January 1945 and June 2019. Twenty-one original articles providing a detailed description of sensory receptors around the hip joint capsule (n=13) and its articular branches (n=8) were reviewed.

Results

The superior portions of the anterior capsule and the labrum were found to be the area of densest nociceptive innervation. Similar to the distribution of nociceptors, mechanoreceptor density was found to be higher anteriorly than posteriorly. Hip joint capsular innervation was found to consistently involve the femoral and obturator nerves, which supply the anterior capsule, and the nerve to the quadratus femoris, which supplies the posterior capsule. The femoral, obturator, and superior gluteal nerves supply articular branches to the most nociceptor-rich region of the hip capsule.

Conclusions

The femoral and obturator nerves and the nerve to the quadratus femoris were found to consistently supply articular branches to both the anterior and posterior capsule of the hip joint. The anterior capsule, primarily supplied by the femoral and obturator nerves, and the superior labrum appear to be the primary pain generators of the hip joint, given their higher density of nociceptors and mechanoreceptors.

Level of Evidence

Anatomy study, literature review.
Does Falls Efficacy Influence the Relationship Between Forward and Backward Walking Speed After Stroke?
Authors: Bansal Kanika , Clark David J , Fox Emily J , Rose Dorian K
Published: February 2021

Objective

Forward walking speed (FWS) is known to be an important predictor of mobility, falls, and falls-related efficacy poststroke. However, backward walking speed (BWS) is emerging as an assessment tool to reveal mobility deficits in people poststroke that may not be apparent with FWS alone. Since backward walking is more challenging than forward walking, falls efficacy may play a role in the relationship between one’s preferred FWS and BWS. We tested the hypothesis that people with lower falls efficacy would have a stronger positive relationship between FWS and BWS than those with higher falls efficacy.

Methods

Forty-five individuals (12.9 ± 5.6 months poststroke) participated in this observational study. We assessed FWS with the 10-meter walk test and BWS with the 3-meter backward walk test. The modified Falls-Efficacy Scale (mFES) quantified falls efficacy. A moderated regression analysis examined the hypothesis.

Results

FWS was positively associated with BWS (R2 = 0.26). The addition of the interaction term FWS × mFES explained 7.6% additional variance in BWS. As hypothesized, analysis of the interaction revealed that people with lower falls efficacy (mFES ≤ 6.6) had a significantly positive relationship between their preferred FWS and BWS, whereas people with higher falls efficacy (mFES > 6.6) had no relationship between their walking speed in the 2 directions.

Conclusions

FWS is positively related to BWS poststroke, but this relationship is influenced by one’s perceived falls efficacy. Our results suggest that BWS can be predicted from FWS in people with lower falls efficacy, but as falls efficacy increases, BWS becomes a separate and unassociated construct from FWS.

Impact

This study provides unique evidence that the degree of falls efficacy significantly influences the relationship between FWS and BWS poststroke. Physical therapists should examine both FWS and BWS in people with higher falls efficacy, but further investigation is warranted for those with lower falls efficacy.
Specific Contribution of Quadriceps Muscle Strength, Endurance, and Power to Functional Exercise Capacity in People With Chronic Obstructive Pulmonary Disease: A Multicenter Study
Authors: Gephine Sarah , Frykholm Erik , Nyberg Andre , Mucci Patrick , Van Hees Hieronymus W H , Lemson Arthur , Klijn Peter , Maltais François , Saey Didier
Published: February 2021

Objective

Various functional muscle properties affect different aspects of functional exercise capacity in people with chronic obstructive pulmonary disease (COPD). The purpose of this study was to investigate the contribution of quadriceps muscle strength, endurance, and power to 6-Minute Walking Distance (6MWD) and 1-minute sit-to-stand test (1STS) performance in people with COPD.

Methods

The study was a prospective, multicenter, cross-sectional study. Anthropometrics, Medical Research Council dyspnea scale, lung function, 6MWD, and 1STS number of repetitions were assessed. Isometric quadriceps strength and endurance, isotonic quadriceps endurance, isokinetic quadriceps strength, and power were assessed on a computerized dynamometer while functional quadriceps power was determined during 5 sit-to-stand repetitions. Univariate and multivariate analyses were performed to determine the contribution of functional muscle properties to the 6MWD and the 1STS number of repetitions.

Results

The study included 70 people with COPD (mean % predicted forced expiratory volume in 1 second = 58.9 [SD = 18.2]). The 6MWD correlated with each functional muscle property except the isometric quadriceps endurance. The number of repetitions during the 1STS correlated with each functional muscle property except isometric measurements. Multivariate models explained 60% and 39% of the variance in the 6MWD and 1STS number of repetitions, respectively, with quadriceps power determined during 5 sit-to-stand repetitions being the muscle functional property with the strongest contribution to the models.

Conclusion

Except for isometric endurance, quadriceps strength, endurance, and power were associated with functional exercise capacity in people with moderate COPD. Among these functional muscle properties, muscle power contributed the most to the 6MWD and 1STS number of repetitions, suggesting that muscle power is more relevant to functional exercise capacity than muscle strength or endurance in people with COPD.

Impact

Understanding the individual contribution of muscle properties to functional status is important to designing interventions. This study provides the guidance that muscle power may be more important to functional exercise capacity than muscle strength or endurance in people with COPD.
Sidney and Finch’s Nomotexnia (Art of Law): Religion, Politics, and Patronage?
Authors: Crowley Timothy D
Published: February 2021

This essay brings to light a little-known manuscript on law and religion dedicated to Sir Philip Sidney: the earliest version of Henry Finch’s Nomotexnia (Art of Law). The manuscript’s two-part structure provides ‘Nomotexnia’, a Ramist-style synopsis of certain topics in English common law pertaining to possessions and criminal offences, followed by a supplement entitled ‘A Conference and Reformation of the Same Law by the Law of God’. Later manuscripts and printed witnesses for Finch’s expansion of the ‘Nomotexnia’ section did not include religious commentary. Material evidence alone places the first manuscript’s production after 1583 but leaves unconfirmed whether or not Sidney commissioned either section of its contents. This study reassesses the manuscript text with an eye to Finch’s and Sidney’s legal interests, family concerns, and religious politics in the mid-1580s. Textual and biographical evidence, combined with reasonable conjecture, suggests that Sidney probably commissioned the ‘Nomotexnia’ section, motivated by a desire for legal knowledge on inheritance and land use, and that Finch probably supplied the ‘Conference and Reformation’ section by his own initiative, asserting a polemical stance on the English church that Sidney would not have adopted.
The formation of interlocked grain in African mahogany (Khaya spp.) analysed by X-ray computed microtomography
Authors: Collings David A , Thomas Jimmy , Dijkstra Stephanie M , Harrington Jonathan J
Published: February 2021

Interlocked grain occurs when the orientation of xylem fibres oscillates, alternating between left- and right-handed spirals in successive wood layers. The cellular mechanisms giving rise to interlocked grain, thought to involve the slow rotation of fusiform initials within the vascular cambium, remain unclear. We suggest that observations of wood structure at the cellular level, but over large areas, might reveal these mechanisms. We assayed timber from several commercially important tropical angiosperms from the genus Khaya (African mahogany) that exhibit interlocked grain using X-ray computed microtomography followed by orthogonal slicing and image processing in ImageJ. Reconstructed tangential longitudinal sections were processed with the ImageJ directionality plug-in to directly measure fibre orientation and showed grain deviations of more than 10° from vertical in both left- and right-handed directions. Grain changed at locally constant rates, separated by locations where the direction of grain change sharply reversed. Image thresholding and segmentation conducted on reconstructed cross sections allowed the identification of vessels and measurement of their location, with vessel orientations then calculated in Matlab and, independently, in recalculated tangential longitudinal sections with the directionality plug-in. Vessel orientations varied more than fibre orientations, and on average deviated further from vertical than fibres at the locations where the direction of grain change reversed. Moreover, the reversal location for vessels was shifted ~400 μm towards the pith compared with the fibres, despite both cell types arising from the same fusiform initials within the vascular cambium. We propose a simple model to explain these distinct grain patterns. Were an auxin signal to control both the reorientation of cambial initials, as well as coordinating the end-on-end differentiation and linkage of xylem vessel elements, then it would be possible for fibres and vessels to run at subtly different angles, and to show different grain reversal locations.
Sexually Transmitted and Blood-borne Infections Among Patients Presenting to a Low-barrier Substance Use Disorder Medication Clinic
Authors: Harvey Leah , Taylor Jessica L. , Assoumou Sabrina A. , Kehoe Jessica , Schechter-Perkins Elissa M. , Bernstein Edward , Walley Alexander Y.
Published: February 2021

Objective:

To study the infection-related needs of patients with substance use disorders initiating care at a low-barrier-to-access program (LBAP) by describing the proportion with human immunodeficiency virus (HIV), hepatitis B and C virus (HBV, HCV), syphilis, gonorrhea, and chlamydia and determining rates of treatment and/or linkage to care.

Methods:

We reviewed the records of patients who completed an intake visit at an LBAP in Boston, MA during the first 9 months after implementation of a standardized intake laboratory panel (January 30, 2017–September 30, 2017).

Results:

Among 393 patients initiating care, 84.7% (n = 333) completed at least 1 screening test. Baseline rates of HIV (9/393, 2.3%), current or past HCV (151/393, 38.4%), and chronic HBV (2/393, 0.5%) were high. Sixty-one new, active infections were identified through screening, including 1 HIV, 3 syphilis, 4 gonorrhea, 3 chlamydia, 1 chronic, and 1 acute HBV, and 48 cases of viremic HCV. Many patients were nonimmune to HBV (102/270, 37.8%) and HAV (112/255, 43.9%). Among new diagnoses, treatment was documented in 88% of bacterial infections and linkage occurred in 0/1 HIV, 2/2 HBV (100.0%), and 16/48 HCV (33.3%) cases.

Conclusions:

Patients initiating SUD care at an LBAP have substantial, unmet infection-related needs. Results justify the inclusion of comprehensive infection prevention, screening, and linkage-to-treatment protocols in LBAPs.
Expanding the Evidence on Integrated Opioid Use Disorder and Infectious Disease Care
Authors: Kattakuzhy Sarah , Rosenthal Elana
Published: February 2021

Low-barrier to access programs has emerged as a way to overcome the significant hurdles associated with buprenorphine initiation. However, there has been limited research evaluating services set in low-barrier programs outside of buprenorphine. In this issue of the Journal of Addiction Medicine, Harvey and colleagues evaluate a sexually transmitted and blood-borne infection screening protocol implemented in a low-barrier access program in Boston, Massachusetts. The data supports that infection protocols can be efficiently implemented in the low-barrier setting, yielding high rates of diagnosis, and the potential for decentralized models of treatment.
Is It Reasonable to Use Indocyanine Green Fluorescence Imaging to Determine the Border of Pedicled TRAM Flap Zone IV?
Authors: Chirappapha Prakasit , Chansoon Tharintorn , Bureewong Siriporn , Phosuwan Songpol , Lertsithichai Panuwat , Sukarayothin Thongchai , Leesombatpaiboon Monchai , Vassanasiri Watoo
Published: February 2021

Background:

The contralateral lateral section (zone IV) of a pedicled transverse rectus abdominis musculocutaneous (TRAM) flap is generally removed intraoperatively. The border of zone IV is usually identified anatomically using the Hartrampf classification. In this study, we used the indocyanine green (ICG) fluorescence method to determine the border of zone IV and find the correlation with clinical flap outcome.

Methods:

The study recruited breast cancer patients who underwent a pedicled TRAM flap reconstruction. The border of zone IV was identified using the intraoperative ICG fluorescence imaging. The medial border of the removed specimen was sent for a pathological examination of vascular density.

Results:

A total of 29 patients underwent a pedicled TRAM reconstruction. In 16 patients, the border of zone IV identified by ICG fluorescent imaging was identical to the anatomical border. The ICG imaging showed distinct perfusion patterns, which we divided into 4 categories: sequential, simultaneous, low midline scar, and delayed pattern. Overall, there were no patient with total flap loss, 1 patient had a partial flap loss and 4 patients had a fat necrosis. Neither the ICG perfusion time nor the pathological vascular density correlates with the clinical flap outcome. The delayed ICG perfusion pattern (category IV) has the highest fat necrosis rate, although it is not statistically significant.

Conclusions:

In this study, more than half of the patients have ICG perfusion corresponding with the Hartrampf zone, which reflected the conventional practice of zone IV pedicled TRAM flap removal. Some ICG perfusion patterns could be helpful, especially in low midline and delayed pattern.
Outpatient Microsurgical Breast Reconstruction
Authors: Martinez Carlos A. , Boutros Sean G.
Published: February 2021

Background:

The extensive nature of perforator-based breast reconstructions, combined with the need for postoperative flap monitoring, often leads to long hospitalizations. We present an early report demonstrating the feasibility and advantages of a modified operative technique and recovery protocol, allowing us to perform outpatient breast reconstructions with the DIEP flap. This follow-up comprises the experience gained, which is expanded to other perforator-based flaps and not limited to DIEP breast reconstructions.

Methods:

We have implemented a general protocol in patients undergoing breast reconstruction with autologous flaps, promoting early mobilization and discharge by improving postoperative pain and decreasing opioid requirements. This protocol includes intraoperative local anesthesia, a microfascial incision for DIEP harvest with rib preservation, along with prophylactic anticoagulation.

Results:

Ninety-two consecutive patients underwent autologous tissue-based breast reconstruction with DIEP, IGAP, and PAP flaps. No intraoperative complications were reported. All patients were discharged within 23 hours, without evidence of flap compromise. One patient required operative takeback for evacuation of a hematoma on postoperative day 4. No partial or total flap losses were documented. The aim of any procedure should be to get to the patient back to the preoperative status as quickly as possible, as prolonged hospitalizations are associated with higher incidences of infection, deep venous thrombosis, overall dissatisfaction, and higher overall costs of care.

Conclusions:

By using a modified operative technique, multimodal pain control, and postoperative anticoagulant therapy, outpatient perforator-flap–based breast reconstructions can be performed with high success and low complication rates.
Orbitocranial Fibrous Dysplasia: Immediate Reconstruction with Titanium 3-dimensional Printing
Authors: Pruksapong Chatchai , Lohwongwatana Boonrat
Published: February 2021

We present the case of an 18-year-old man who was referred to our department with a suspected tumor in the right orbital region, which caused exophthalmos due to its pressure effect. Preoperative CT imaging revealed an expansile ground-glass appearance of bone mass, with sclerotic bone on the right frontal bone (right superior orbital wall). There was no orbital mass and no enlargement of the extraocular muscles and tendons; the retrobulbar fat and optic nerve appeared unremarkable. A preoperative tissue biopsy confirmed the FD. Complete tumor removal was performed via the right hemicoronal approach. The orbital roof and temporal bone defect were immediately reconstructed using the 3-dimensional titanium printing plate.
Perception of Implants among Breast Reconstruction Patients in Montreal
Authors: Bouhadana Gabriel , Chocron Yehuda , Azzi Alain Joe , Davison Peter G.
Published: February 2021

Background:

In light of the recent surge of media coverage and social media influence regarding breast implants, it is essential to understand patients’ concerns and misconceptions so that we can better serve them.

Methods:

The authors designed a survey study for assessing the awareness and perception of patients toward breast implant–associated anaplastic large cell lymphoma (BIA-ALCL) and breast implant illness (BII). In total, 130 patients presenting to the senior author’s breast reconstruction clinic completed the survey. The survey assessed patients’ knowledge on and their perception of BIA-ALCL and BII.

Results:

“News article” and “Television” were most often selected as sources of information for BIA-ALCL (21% and 20%, respectively) and BII (20% and 25%, respectively). A total of 100 patients (77%) had previous knowledge of BIA-ALCL. Forty-seven percent (n = 47/100) responded that they were unsure of the fate of a person diagnosed with BIA-ALCL, and 25% (n = 25/100) were unaware of the association between BIA-ALCL and specific implant type. Patients who were unaware of BIA-ALCL prognosis reported being less likely to receive breast implants in the future (P = 0.012, χ2 = 19.48). Eighty-nine patients (68%) had previous knowledge of BII. A total of 60 symptoms were mentioned by patients, with “Fatigue” (12%, n = 26) being cited the most often.

Conclusions:

The present survey highlights the importance for plastic surgeons to frequently discuss these entities with their patients. This should be done despite the obscurity of BII, in an effort to offer the best available evidence to our patients.
New Algorithm for Chest-wall Surgery and Quality of Life Assessment in Female-to-male Reassignment Patients
Authors: Ramella Vittorio , Papa Giovanni , Stocco Chiara , Torelli Lucio , Vasselli Benedetta , Arnež Zoran M.
Published: February 2021

Background:

Chest-wall contouring surgery (chest-wall reconstructive surgery) is often the first surgical procedure in female-to-male (FtM) gender reassignment surgery (GRS). The main goal of this procedure is to create an aesthetically pleasing male-like chest contour. No universally accepted algorithm exists for detection of the appropriate surgical technique. Also, there is no tool for objective evaluation of the quality of life and satisfaction of these patients after the operation.

Methods:

This study involves a single-center clinical trial assessing the patients who underwent subcutaneous mastectomy in FtM GRS between 2003 and 2019. The selection of patients was based on the new “simplified” algorithm consisting of 2 different surgical techniques: the semicircular and the double-incision with free nipple grafting. The selection was based on 3 criteria: breasts size, breast ptosis, and skin elasticity. The outcomes and complication rates were collected and analyzed. The patients’ satisfaction and Quality of Life was assessed with a 5-point Likert scale questionnaire, specifically conceived for FtM patients. The aesthetic evaluation was performed using a 5-point Likert scale dealing with the 5 items featuring as the main goals of GRS.

Results:

184 mastectomies were performed in 92 FtM GRS patients. The overall reoperation rate was 11.9%. The patient survey revealed both a high satisfaction rate and a good aesthetic result (4.4/5).

Conclusions:

The proposed algorithm facilitates the selection of the most suitable technique for top surgery. The patient satisfaction rate evaluated by the proposed Health-Related Quality of Life questionnaire confirmed the outcomes of the use of the algorithm. Further studies to validate the proposed evaluating tools are needed.
Hyperbaric Oxygen Therapy: Descriptive Review of the Technology and Current Application in Chronic Wounds
Authors: Hajhosseini Babak , Kuehlmann Britta A. , Bonham Clark A. , Kamperman Kathryn J. , Gurtner Geoffrey C.
Published: February 2021

Hyperbaric oxygen therapy (HBOT) serves as “primary” or “adjunctive” therapy in a wide range of pathologies. It is considered the mainstay of management for potentially life-threatening conditions such as carbon monoxide poisoning, decompression illness, and gas embolisms. Moreover, HBOT has been utilized for decades as an adjunctive therapy in a variety of medical disciplines, including chronic wounds, which affect approximately 6.5 million Americans annually. In general, chronic wounds are characterized by hypoxia, impaired angiogenesis, and prolonged inflammation, all of which may theoretically be ameliorated by HBOT. Nonetheless, the cellular, biochemical, and physiological mechanisms by which HBOT achieves beneficial results in chronic wounds are not fully understood, and there remains significant skepticism regarding its efficacy. This review article provides a comprehensive overview of HBOT, and discusses its history, mechanisms of action, and its implications in management of chronic wounds. In particular, we discuss the current evidence regarding the use of HBOT in diabetic foot ulcers, while digging deeply into the roots of controversy surrounding its efficacy. We discuss how the paucity of high-quality research is a tremendous challenge, and offer future direction to address existing obstacles.
“Hybrid Reconstruction” for Zygomaticomaxillary Complex Defect Using CAD/CAM: A Case Report
Authors: Mahendru Sanjay , Jain Rahul , Garg Saurabh , Singh Hardeep , Jain Ankit , Sarin Deepak , Khazanchi Rakesh K.
Published: February 2021

In this unique case report, we present a patient of left zygomatico maxillary complex reconstruction with a combination of autogenous tissue (osteocutaneous free fibula flap) and alloplastic implant [patient-specific templated polymethyl methacrylate (PMMA)]. In such large defects, reconstruction using either autogenous tissue or alloplastic implant alone is inadequate and leads to poor functional and aesthetic outcomes. In this case we used osteocutaneous free fibula flap for left alveolus and patient-specific templated PMMA implant for reconstruction of orbital wall and zygoma. Osseointegrated implants were placed secondarily in the fibula for complete dental rehabilitation. With the use of virtual surgical planning and 3D printing we were able to achieve a good result for a complex defect. Since both autogenous tissue and alloplastic implant were used for complete reconstruction, we have named this as “hybrid reconstruction.”
How to Embrace Antiracism as a US Plastic Surgeon: Definitions, Principles, and Practice
Authors: Bradford Perry S. , DeGeorge Brent R. , Williams Steven H. , Butler Paris D.
Published: February 2021

The United States’s overdue awakening on systemic and structural racism has triggered global dialogue regarding racial inequities. Historically, discrimination and practitioner bias have resulted in poorer health and health outcomes in minority communities. To address racial and ethnic disparities in healthcare, it is imperative that plastic surgeons, trainees, and staff understand definitions to create a socially conscious environment in the workplace. We explore various measures that can be implemented to develop antiracist practices in the field of plastic surgery and ultimately to provide a foundation to improve diversity within our discipline and beyond.
The Use of Integra Dermal Regeneration Templates and Cortical Bone Fenestrations over Exposed Tibia
Authors: Hughes Liam P. , Forman Steven , Krieg James C. , Hughes William B.
Published: February 2021

We present the case of an 86-year-old woman who suffered full-thickness soft tissue loss secondary to degloving injury to the lower left limb, resulting in an exposed tibia. This patient underwent drilling to create artificial fenestrations in the cortical bone followed by placement of Integra dermal regeneration template. The technique of drilling fenestrations to expose underlying vasculature of cortical bone has not previously been described in its relationship with Integra dermal regeneration templates in large degloving injuries of the lower limb. This technique enabled us to perform earlier skin grafting and ultimately resulted in complete and timely wound closure. We present this case as a comparable alternative treatment in cases of reconstructive surgery secondary to severe burns or trauma to reduce the time required for successful wound closure over exposed bone in full-thickness tissue loss injuries of the lower limb.