bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cystic fibrosis in the kidney: new lessons from impaired renal HCO3− excretion
Authors: Berg Peder , Jeppesen Majbritt , Leipziger Jens 
Published: May 2021

Purpose of review
A key role of cystic fibrosis transmembrane conductance regulator (CFTR) in the kidney has recently been uncovered. This needs to be integrated into the understanding of the developed phenotypes in cystic fibrosis (CF) patients.

Recent findings
In the beta-intercalated cells of the collecting duct , CFTR functions in very similar terms as established in the exocrine pancreatic duct and both CFTR and SLC26A4 (pendrin) orchestrate regulated HCO3
− secretion. Like in the pancreas, the hormone secretin is a key agonist to activate renal HCO3
− secretion. In mice lacking CFTR or pendrin, acute and chronic base challenges trigger marked metabolic alkalosis because collecting duct base secretion is defective. Also in CF patients, the ability to acutely increase renal HCO3
− excretion is markedly reduced.

Summary
The now much enlarged understanding of CFTR in the kidney may permit the measurement of challenged urine HCO3
− excretion as a new biomarker for CF. We suggest a new explanation for the electrolyte disorder in CF termed Pseudo-Bartter Syndrome. The hallmark electrolyte disturbance features of this can be well explained by a reduced function of collecting duct Cl−/HCO3
− exchange. Eventually, we suggest the diagnostic term distal renal tubular alkalosis to cover those disturbances that causes metabolic alkalosis by a reduced collecting duct base secretion.
Prolonged Mechanical Ventilation in Children: Review of the Definition
Authors: Colleti José , Azevedo Rafael Teixeira , de Oliveira Caino Felipe Rezende , de Araujo Orlei Ribeiro 
Published: May 2021

OBJECTIVES:
To review existing definitions of prolonged mechanical ventilation in children.

DESIGN:
Review of the literature.

SETTING:
Not applicable.

PATIENTS:
Pediatric patients under mechanical ventilation.

INTERVENTIONS:
Not applicable.

MEASUREMENTS AND MAIN RESULTS:
We searched the literature for original research on prolonged mechanical ventilation in children using the PubMed, Embase, and Cochrane Library databases. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed, and we extracted patient characteristics, duration of mechanical ventilation, outcomes, and associated complications. We identified 30 articles for qualitative analysis and found a wide variety of definitions, varying from 48 hours to 6 months. The most frequently used definitions of prolonged mechanical ventilation were greater than 7 days, greater than 14 days, and greater than 21 days. There was no high-quality evidence of a definition for prolonged mechanical ventilation in children.

CONCLUSIONS:
There is limited evidence to determine the definition of prolonged mechanical ventilation in children. The variety of definitions is a sign of the need for a consensus definition of pediatric prolonged mechanical ventilation.
Creating a Dedicated Pandemic Ambulatory Clinic: Lessons Learned From COVID-19
Authors: Kwon Joshua , Hedges Mary , Jackson K. Dawson , Keimig Andrew , Francis Dawn 
Published: May 2021

Background and Objectives:
COVID-19 is highly infectious and the pandemic requires many adaptations to how we deliver medical care. Early in the pandemic, much of this focus was on hospital and emergency department care delivery models to ensure the safety of non–COVID-19 patients and health care workers. However, providing much needed outpatient assessments for COVID-19 patients during a pandemic is also fraught with challenges. From our review of the literature, best practices for a dedicated pandemic ambulatory outpatient clinic have not previously been described. We present a model for creating a dedicated ambulatory pandemic clinic at our institution for the acute care needs of COVID-19 patients.

Methods:
To address the current pandemic, the Mayo Acute Symptoms of COVID-19 Clinic was implemented on April 13, 2020, with the aims of providing a stand-alone location for COVID-19 patients to have acute outpatient evaluations as well as diagnostics.

Results:
Recognized challenges addressed included consideration of airflow recirculation patterns in standard medical office buildings, optimization of protocols to conserve personal protective equipment (PPE), limiting total exposure time during patient flow, and reducing surfaces and spaces that patients would physically contact. To this end, unique methods of patient scheduling, patient flow process, staff training, and PPE protocols were developed and are explained in detail in this article.

Conclusion:
In the COVID-19 pandemic, as well as inevitably in future pandemics, outpatient medical facilities need to be prepared to care for nonhospitalized and nonemergent pandemic patients. We offer a practical approach that has been successful at our institution, with opportunity for local adaptation based on need and resources.
Hyperthyroidism Incidentally Noted on Lymphoscintigraphy
Authors: Liu Yong , Tong Guansheng , Wen Zhe , Zhuang Hongming 
Published: May 2021

AbstractA 43-year-old woman with edema in both left upper limb and lower limb underwent lymphoscintigraphy to evaluate possible lymphedema. Two separate lymphoscintigraphies, one for the lower and the other for the upper limbs, were performed with interval of 3 days. Incidentally, an activity in the region of the thyroid glands was noted in the delayed images of both studies. Subsequently, Graves disease was diagnosed based on the patient’s symptoms and the results of laboratory examinations.
Neuroblastoma Shown on 18F-DOPA PET/CT Performed to Evaluate Congenital Hyperinsulinism
Authors: O’Brien Sophia R. , States Lisa J. , Zhuang Hongming 
Published: May 2021

Abstract

18F-DOPA PET/CT was performed to evaluate congenital hyperinsulinism in a 55-day-old boy with hypoglycemia. The images revealed not only a focal 18F-DOPA–avid lesion in the pancreas but also in a left thoracic paraspinal neuroblastoma.
Prospective Evaluation of the First Integrated Positron Emission Tomography/Dual-Energy Computed Tomography System in Patients With Lung Cancer
Authors: Martin Simon S. , van Assen Marly , Burchett Philip , Monti Caterina B. , Schoepf U. Joseph , Ravenel James , Rieter William J. , Vogl Thomas J. , Costello Philip , Gordon Leonie , De Cecco Carlo N. 
Published: May 2021

Purpose:
The aim of this pilot study was to prospectively evaluate the first integrated positron emission tomography (PET)/dual-energy computed tomography (DECT) system performance in patients with non–small cell lung cancer (NSCLC).

Materials and Methods:
In this single-center, prospective trial, consecutive patients with NSCLC referred for a PET study between May 2017 and June 2018 were enrolled. All patients received contrast-enhanced imaging on a clinical PET/DECT system. Data analysis included PET-based standard uptake values (SUVmax) and DECT-based iodine densities of tumor masses, lymph nodes, and distant metastases. Results were analyzed using correlation tests and receiver operating characteristics curves.

Results:
The study population was composed of 21 patients (median age 62 y, 14 male patients). A moderate positive correlation was found between iodine density values (2.2 mg/mL) and SUVmax (10.5) in tumor masses (ρ=0.53, P<0.01). Iodine density values (2.3 mg/mL) and SUVmax (5.4) of lymph node metastases showed a weak positive correlation (ρ=0.23, P=0.14). In addition, iodine quantification analysis provided no added value in differentiating between pathologic and nonpathologic lymph nodes with an area under the curve (AUC) of 0.55 using PET-based SUVmax as the reference standard. A weak positive correlation was observed between iodine density (2.2 mg/mL) and SUVmax in distant metastases (14.9, ρ=0.23, P=0.52).

Conclusions:
The application of an integrated PET/DECT system in lung cancer might provide additional insights in the assessment of tumor masses. However, the added value of iodine density quantification for the evaluation of lymph nodes and distant metastases seems limited.
The Edmonton Obesity Staging System Predicts Postoperative Complications After Abdominoplasty
Authors: Simunovic Filip , Bonaventura Bastian , Schneider Laura , Horner Verena K. , Weber Janick , Stark G. Björn , Kalash Ziad 
Published: May 2021

Background
This study investigates the relationship between Edmonton Obesity Staging System (EOSS) and the occurrence of postoperative complications after abdominoplasty in massive weight loss patients.

Methods
A single-institution retrospective review of patients undergoing abdominoplasty between 2009 and 2019 after massive weight loss. Demographic data, laboratory findings, known risk factors for postoperative complications, as well as data on major and minor complications were extracted from the patient charts. Logistic regression models were used to investigate the relationship between the variables.

Results
Four hundred and five patients were included in the study. The prevalence of EOSS stages was: 0 (no comorbidities, N = 151, 37%), 1 (mild conditions, N = 40, 10%), 2 (moderate conditions, N = 149, 36%) and 3 (severe conditions, N = 70, 17%). Regression analysis showed that, controlling for body mass index (BMI), BMI Δ (maximal BMI − BMI at presentation), bariatric surgery, volume of resected tissue, and duration of surgery, EOSS stage significantly associated with the occurrence of postoperative complications. Compared with EOSS stage 0, EOSS stages 2 and 3 patients were associated with significantly more minor and major complications, respectively. The volume of resected tissue, BMI Δ, and age were associated with the occurrence of major complications. A regression model of comorbidities comprising the EOSS revealed a significant association of variables diabetes mellitus and hypertension with the occurrence of postoperative complications.

Conclusions
Edmonton Obesity Staging System is a robust predictor of postoperative complications in abdominoplasty.
Qualitative Analysis of Single-Site Headache Surgery
Authors: Israel Jacqueline S. , Gutierrez-Meza Diana , Albano Nicholas J. , Smith Jeremy P. , Abd-Elsayed Alaa , Schwarze Margaret L. , Macdonald Cameron L. , Afifi Ahmed M. 
Published: May 2021

Background
Migraine surgery has been shown to be efficacious, but nuanced effects of surgery on pain and individuals' lives remain incompletely understood. Surgery may be performed at a single or multiple “primary” sites. The aims of this study were to investigate patient perceptions following single-site surgery and compare themes in patients undergoing single-site surgery with those from a previously published conceptual framework generated with patients undergoing multisite surgery.

Methods
Patients who underwent single-site headache surgery participated in open-ended interviews at least 1 year after surgery. Participants (n = 14) had undergone either occipital, temporal, or nasoseptal site surgery. A multidisciplinary team analyzed transcripts. Recurring themes were identified and compared and contrasted to those observed in patients who underwent multiple-site surgery (n = 15) in a previous study (Plast Reconstr Surg 2019;144(4):956–964).

Results
Similar recurring themes emerged from the single-site cohort, and the conceptual framework was applicable to all participants. Two new themes emerged from the single-site analysis. First, 5 of 14 participants described being “migraine-free” postoperatively, a finding not observed in the multisite group. Second, several individuals described financial benefits after surgery, via decreased prescription medication requirements, raises at work, and improved productivity.

Conclusions
Single-site headache surgery appears to positively impact patients' lives in ways that support and expand upon previously published outcomes. Patients undergoing surgery at a single site may be more likely to experience a “pain-free” state, which may relate to the underlying pathophysiology of chronic headache. The effect of surgery on finances appears to be an outcome of interest to patients, which should be explored further.
Hemangioma Endothelial Cells and Hemangioma Stem Cells in Infantile Hemangioma
Authors: Sun Yuming , Qiu Fengzhen , Hu Chengjun , Guo Yu , Lei Shaorong 
Published: May 2021

BackgroundHemangioma is one of the most common benign tumors in infants and young children. The 2 most important cells in the course of infantile hemangioma (IH) are hemangioma stem cells (HemSCs) and hemangioma endothelial cells (HemECs). Infantile hemangioma is characterized by massive proliferation of HemECs, but current studies indicate that HemSCs play an important role in pathogenesis of IH.ObjectiveThis review aimed to identify molecules that influence HemSC differentiation and HemEC proliferation and apoptosis to help clarify the pathogenesis of IH and provide novel drug targets for the treatment of IH.MethodsRelevant basic science studies related to IH were identified by searching Google Scholar, Embase, PubMed, MEDLINE, and peer-reviewed journal articles.ResultHemangioma stem cells can differentiate into HemECs, pericytes, and adipocytes. In the proliferating phase of IH, HemSCs mainly differentiate into HemECs and pericytes to promote angiogenesis. In the regressive phase, they mainly differentiate into adipocytes. Therefore, increasing the proportion of HemSCs differentiating into adipocytes, inhibiting the proliferation of HemECs, and promoting the apoptosis of HemECs can facilitate the regression of IH.
Facial Injections and Blindness
Authors: Li Dan , Zhang Hengshu 
Published: May 2021

Abstract
With the sudden emergence of new medical aesthetic fillers, the number of fillers injected worldwide has exploded, but there are also worrying risks in the pursuit of beauty. At present, many cases of blindness caused by injection of aesthetic fillers have been reported. Most of the cases are caused by irreversible vascular embolism. This is a rare yet greatly feared complication of using facial cosmetic fillers. This article reviewed and analyzed the literature and summarized the changes in the anatomical structure of facial blood vessels related to blindness during facial injection.
Adipose Grafting for Volume and Scar Release
Authors: Le John M. , Bosworth Jeremy W. , Honeywell Brandon , Ananthasekar Shivani , Collawn Sherry S. 
Published: May 2021

AbstractAdipose fat grafting (AFG) is a popular technique used to add volume in the face, breasts, and other tissue deficient areas of the body. In terms of scar release, not only has fat provided additional soft tissue coverage but also the relief of pain in scars in those patients suffering from disease processes, such as complex regional pain syndrome with steroid-induced atrophy, burn scars, morphea, and lupus. The purpose of this article is to demonstrate the senior author's technique and outcomes of using AFG in the face and body for treating volume deficiency, atrophic scarring, and deformities.A retrospective chart review of 127 AFG procedures of the face and body from September 2006 to September 2019 was performed. Of these, 14 patients had scar releases performed with fat grafting of areas of scar contracture. Fat was harvested from the abdomen, thighs, and flanks using Toomey syringes or an enclosed power-assisted system with 3.7- or 3.0-mm cannulas. Grafting in small areas, such as the face, was performed with the 0.9-mm blunt cannula.The majority of AFG was completed in the face (45%), followed by breasts (22%), and scar contracture (16%). The mean volume of fat grafted in procedures involving the breasts, buttocks, and face was 102, 182, and 21 mL, respectively. For scar contracture, the mean volume was 38 mL and for deformations, 27 mL. Sixteen percent of the cohort required at least 1 additional AFG procedure to achieve satisfactory results. There were no major complications, such as skin loss, vascular injury, embolization, or blindness. Minor complications, such as erythema, edema, and hematoma at the fat harvest or graft site, did occur and were managed with local measures.Autologous fat grafting has consistently resulted in volume correction. In addition, in patients with autoimmune disorders, burn scars, and retracted scars, not only has there been volume correction but also decreased pain in the area of treatment. In our series of patients, we described our technique of AFG for the face, body, and scar contracture. Our results demonstrate that AFG remains an inexpensive, safe, and effective treatment option to achieve volume.
Nationwide Analysis of the Distribution of Level 1 and Level 2 Trauma Centers Per Population Growth and Motor Vehicle Collision Injuries/Fatalities Utilizing Geographic Information Systems Mapping Technology
Authors: Sen-Crowe Brendon , Sutherland Mason , McKenney Mark , Elkbuli Adel 
Published: May 2021

Background:
Trauma centers (TCs) improve patient outcomes. Few investigations detail the US geographical distribution of Level 1 and 2 TCs (L1TCs, L2TCs) regarding motor vehicle collision (MVC) injuries/fatalities.

Objective:
We utilized Geographic Information Systems mapping to investigate the distribution of L1TCs and L2TCs in relation to population growth, MVC injuries, and MVC fatalities at the county and regional level to identify any disparities in access to trauma care.

Methods:
A cross-sectional analysis of L1TC and L2TC distribution, MVC injuries/fatalities, and population growth from 2010 to 2018. Information was gathered at the county and region level for young adults (aged 15–44), middle-aged adults (45–64), and elderly (≥65).

Results:
A total of 263 L1TCs across 46 states and 156 counties and 357 L2TCs across 44 states and 255 counties were identified. The mean distance between L1TCs and L2TCs is 28.3 miles and 31.1 miles, respectively. Seven counties were identified as being at-risk, all in the Western and Southern US regions that experienced ≥10% increase in population size, upward trends in MVC injuries, and upward trends MVC fatalities across all age groups.

Conclusions:
Seven US counties containing ≤2 ACSCOT-verified and/or state-designated L1TCs or L2TCs experienced a 10% increase in population, MVC injuries, and MVC fatalities across young, middle-aged and elderly adults from 2010 to 2018. This study highlights chronic disparities in access to trauma care for MVC patients. Evaluation of state limitations regarding the distribution of L1TCs and L2TCs, frequent evaluation of local and regional trauma care needs, and strategic interventions to improve access to trauma care may improve patient outcomes for heavily burdened counties.
Tracheostomy for COVID-19 Respiratory Failure
Authors: Mahmood Kamran , Cheng George Z. , Van Nostrand Keriann , Shojaee Samira , Wayne Max T. , Abbott Matthew , Nettlow Darrell , Parish Alice , Green Cynthia L. , Safi Javeryah , Brenner Michael J. , De Cardenas Jose 
Published: May 2021

Objective:
The aim of this study was to assess the outcomes of tracheostomy in patients with COVID-19 respiratory failure.

Summary Background Data:
Tracheostomy has an essential role in managing COVID-19 patients with respiratory failure who require prolonged mechanical ventilation. However, limited data are available on how tracheostomy affects COVID-19 outcomes, and uncertainty surrounding risk of infectious transmission has led to divergent recommendations and practices.

Methods:
It is a multicenter, retrospective study; data were collected on all tracheostomies performed in COVID-19 patients at 7 hospitals in 5 tertiary academic medical systems from February 1, 2020 to September 4, 2020.

Result:
Tracheotomy was performed in 118 patients with median time from intubation to tracheostomy of 22 days (Q1–Q3: 18–25). All tracheostomies were performed employing measures to minimize aerosol generation, 78.0% by percutaneous technique, and 95.8% at bedside in negative pressure rooms. Seventy-eight (66.1%) patients were weaned from the ventilator and 18 (15.3%) patients died from causes unrelated to tracheostomy. No major procedural complications occurred. Early tracheostomy (≤14 days) was associated with decreased ventilator days; median ventilator days (Q1–Q3) among patients weaned from the ventilator in the early, middle and late groups were 21 (21–31), 34 (26.5–42), and 37 (32–41) days, respectively with P = 0.030. Compared to surgical tracheostomy, percutaneous technique was associated with faster weaning for patients weaned off the ventilator [median (Q1–Q3): 34 (29–39) vs 39 (34–51) days, P = 0.038]; decreased ventilator-associated pneumonia (58.7% vs 80.8%, P = 0.039); and among patients who were discharged, shorter intensive care unit duration [median (Q1–Q3): 33 (27–42) vs 47 (33–64) days, P = 0.009]; and shorter hospital length of stay [median (Q1–Q3): 46 (33–59) vs 59.5 (48–80) days, P = 0.001].

Conclusion:
Early, percutaneous tracheostomy was associated with improved outcomes compared to surgical tracheostomy in a multi-institutional series of ventilated patients with COVID-19.
Effects of donepezil on the amplitude of low-frequency fluctuations in the brain of patients with Alzheimer’s disease: evidence from resting-state functional magnetic resonance imaging
Authors: Yang Hua , Zhang Jiangtao , Cheng Jianan 
Published: May 2021

Objectives
To monitor the effects of donepezil on spontaneous neuronal activity (SNA), and the mechanisms underlying these effects in patients with mild-to-moderate Alzheimer’s disease, using the amplitude of low-frequency fluctuations (ALFFs), a metric of resting-state functional MRI (rs-fMRI).

Methods
Eleven patients with Alzheimer’s disease were treated with donepezil for 6 months. Before and after treatment, the Mini-Mental State Examination (MMSE), Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADAS-cog), Clinical Dementia Rating (CDR), Neuropsychiatric Inventory and Activities of Daily Living scores, along with rs-fMRI of patients were assessed. Eleven age-, sex-, and education-matched controls underwent MMSE and CDR assessments and rs-fMRI at enrollment. The ALFFs of the whole brain were obtained and compared between the groups.

Results
Following donepezil treatment, MMSE scores increased (P = 0.043) and ADAS-cog scores decreased (P = 0.010). Regarding SNA post-treatment, ALFF increased significantly in the right triangular part of the inferior frontal gyrus (IFGtriang; P = 0.030; d = −0.595) and the right orbital part of the inferior frontal gyrus (P = 0.044; d = −0.628) and decreased significantly in the left medial orbital part of the superior frontal gyrus (P = 0.039; d = 0.606) and the right gyrus rectus (P = 0.010; d = 0.609). Furthermore, the changes in ADAS-cog scores from before to after treatment were positively correlated with the changes in ALFF in the right IFGtriang (r = 0.645; P = 0.032).

Conclusions
Donepezil improved SNA in the frontal lobe of patients with Alzheimer’s disease. Therefore, ALFF was demonstrated to be a potential tool for assessing the effectiveness of Alzheimer’s disease treatment.
The nematic-isotropic transition of the Lebwohl–Lasher model revisited
Authors: Skačej Gregor , Zannoni Claudio 
Published: May 2021

We revisited the nematic-isotropic (NI) transition of the Lebwohl–Lasher lattice model with a detailed investigation of samples containing 200 × 200 × 200 particles. The large-scale Monte Carlo (MC) simulations involved were carried out following the standard Metropolis, as well as the cluster MC Wolff algorithms. A notable free-energy barrier was observed between the isotropic and nematic phase, leading to long-lived metastable states and hysteresis. We provide an improved estimate of the nematic-isotropic transition temperatureTNI, of the supercooling and superheating temperatures, of the temperature of divergence of pretransitional effectsTC∗as well as an analysis of the size distribution of the ordered domains aboveTNI, contributing to a better understanding of this transition of key importance for liquid crystals.This article is part of the theme issue ‘Topics in mathematical design of complex materials’.