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result(s) for
"Sam, Andre-Philippe"
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Post-Mastectomy Breast Reconstruction Disparities: A Systematic Review of Sociodemographic and Economic Barriers
by
Chu, Michael
,
Carre, Antoine L.
,
Chang, Jeff
in
African Americans
,
Breast cancer
,
Breast Neoplasms - surgery
2024
Background: Breast reconstruction (BR) following mastectomy is a well-established beneficial medical intervention for patient physical and psychological well-being. Previous studies have emphasized BR as the gold standard of care for breast cancer patients requiring surgery. Multiple policies have improved BR access, but there remain social, economic, and geographical barriers to receiving reconstruction. Threats to equitable healthcare for all breast cancer patients in America persist despite growing awareness and efforts to negate these disparities. While race/ethnicity has been correlated with differences in BR rates and outcomes, ongoing research outlines a multitude of issues underlying this variance. Understanding the current and continuous barriers will help to address and overcome gaps in access. Methods: A systematic review assessing three reference databases (PubMed, Web of Science, and Ovid Medline) was carried out in accordance with PRISMA 2020 guidelines. A keyword search was conducted on 3 February 2024, specifying results between 2004 and 2024. Studies were included based on content, peer-reviewed status, and publication type. Two independent reviewers screened results based on title/abstract appropriateness and relevance. Data were extracted, cached in an online reference collection, and input into a cloud-based database for analysis. Results: In total, 1756 references were populated from all databases (PubMed = 829, Ovid Medline = 594, and Web of Science = 333), and 461 duplicate records were removed, along with 1147 results deemed ineligible by study criteria. Then, 45 international or non-English results were excluded. The screening sample consisted of 103 publications. After screening, the systematic review produced 70 studies with satisfactory relevance to our study focus. Conclusions: Federal mandates have improved access to women undergoing postmastectomy BR, particularly for younger, White, privately insured, urban-located patients. Recently published studies had a stronger focus on disparities, particularly among races, and show continued disadvantages for minorities, lower-income, rural-community, and public insurance payers. The research remains limited beyond commonly reported metrics of disparity and lacks examination of additional contributing factors. Future investigations should elucidate the effect of these factors and propose measures to eliminate barriers to access to BR for all patients.
Journal Article
Characterizing Trends of Lymphedema After Axillary Lymph Node Dissection with and Without Immediate Lymphatic Reconstruction
by
Chu, Michael W.
,
Chang, Jeff
,
Sam, Andre-Philippe
in
Body mass index
,
Breast cancer
,
California
2025
Background and Objectives: Breast cancer-related lymphedema (BCRL) is a complication of axillary lymph node dissection (ALND). Immediate lymphatic reconstruction (ILR) may help to decrease lymphedema after ALND by creating lymphatic bypasses. This retrospective single-institution study aimed to compare lymphedema in patients undergoing ALND with and without ILR. Materials and Methods: Bioimpedance and limb measurements determined the presence of BCRL. The categorical data that were collected and analyzed included BMI, comorbidities, BCRL onset, and number of lymphatic bypasses. Pearson’s chi-square test and multivariable logistic regression were performed to identify factors associated with the onset of lymphedema. An odds ratio compared the incidence of BCRL with and without ILR. Results: In total, 186 patients underwent ALND, 44 (24%) with ILR and 142 (76%) without. The mean number of bypasses during ILRs created was 3.54. The odds of developing lymphedema with ILR were 64% lower than for ALND alone. ILR patients who developed BCRL had a mean onset of 543 days post-operatively versus 389 days in the control group. Age, ethnicity, BMI, and bypass amount had no significant influence on lymphedema development. Conclusions: ILR was associated with lower rates of BCRL after ALND. Patients who developed lymphedema despite undergoing ILR did so 8 months later than the controls.
Journal Article
Barriers to Post-Mastectomy Breast Reconstruction: A Comprehensive Retrospective Study
by
Chu, Michael
,
Carre, Antoine L.
,
Cornely, Ronald M.
in
African Americans
,
Breast
,
Breast cancer
2025
Background and Objectives: Breast reconstruction following mastectomy improves quality of life and psychosocial outcomes, yet it is not consistently performed despite multiple federal mandates. Current data shows decreased reconstruction in minority races, those with a low socioeconomic status, and those holding public health insurance. Many barriers remain misunderstood or unstudied. This study examines barriers to post-mastectomy breast reconstruction to promote a supportive clinical climate by addressing multifactorial obstacles to equitable access to care. Materials and Methods: The California Cancer Registry Data Surveillance, Epidemiology, and End Results (SEER) database and California Health and Human Services Agency Cancer Surgeries Database (2013–2021 and 2000–2021, respectively) were used in this retrospective observational study on mastectomy with immediate breast reconstruction (IBR), delayed breast reconstruction (DBR), or mastectomy only (MO) rates. Data were collected on age, sex, race, insurance type, hospital type, socioeconomic status, and residence. Pearson’s chi-square analysis was performed. Results: We found that 168,494 mastectomy and reconstruction surgeries were performed (82.36% MO, 7% IBR, 10.6% DBR). The 40–49 age group received significantly less MO (38.1%) compared to the 70–74 age group (94.8%, (p = <0.001). Significantly more reconstruction was carried out in patients with private, HMO, or PPO insurance (IBR 75.86%, DBR 75.32%, p = <0.001). Almost all breast surgeries were in urban areas as opposed to rural/isolated rural areas (96.02% vs. 1.55%, p = <0.001). There was no significant difference between races. Of all surgeries, 7.46% were completed in a cancer center with significantly higher rates of IBR. LA County, San Luis Obispo/Ventura County, and Northern CA had significantly more MO than other regions (p = <0.001). Conclusions: Reconstruction rates after mastectomy are low, with only 17.64% of patients undergoing reconstruction. Nationally, 70.5% of patients received MO, with 29.6% undergoing reconstruction. Significant factors positively contributing to reconstruction were private insurance, high SES, cancer center care, and urban residency. Identified barriers include public health insurance enrollment, rural or non-urban residence, older age, low SES, and non-white race/ethnicity, indicating potential monetary influences on care.
Journal Article
Using machine learning models to predict oxygen saturation following ventilator support adjustment in critically ill children: a single center pilot study
by
Ghazal, Sam
,
Noumeir, Rita
,
Bouachir, Wassim
in
Algorithms
,
Artificial intelligence
,
Children
2018
Clinicians' experts in mechanical ventilation are not continuously at each patient's bedside in an intensive care unit to adjust mechanical ventilation settings and to analyze the impact of ventilator settings adjustments on gas exchange. The development of clinical decision support systems analyzing patients' data in real time offers an opportunity to fill this gap. The objective of this study was to determine whether a machine learning predictive model could be trained on a set of clinical data and used to predict hemoglobin oxygen saturation 5 min after a ventilator setting change. Data of mechanically ventilated children admitted between May 2015 and April 2017 were included and extracted from a high-resolution research database. More than 7.105 rows of data were obtained from 610 patients, discretized into 3 class labels. Due to data imbalance, four different data balancing process were applied and two machine learning models (artificial neural network and Bootstrap aggregation of complex decision trees) were trained and tested on these four different balanced datasets. The best model predicted SpO2 with accuracies of 76%, 62% and 96% for the SpO2 class \"< 84%\", \"85 to 91%\" and \"> 92%\", respectively. This pilot study using machine learning predictive model resulted in an algorithm with good accuracy. To obtain a robust algorithm, more data are needed, suggesting the need of multicenter pediatric intensive care high resolution databases.
The JCMT BISTRO Survey: The Magnetic Fields of the IC 348 Star-forming Region
by
Mairs, Steve
,
Parsons, Harriet
,
Griffin, Matt
in
Grain growth
,
Magnetic fields
,
Magnetic properties
2024
We present 850 \\(\\mu\\)m polarization observations of the IC 348 star-forming region in the Perseus molecular cloud as part of the B-fields In STar-forming Region Observation (BISTRO) survey. We study the magnetic properties of two cores (HH 211 MMS and IC 348 MMS) and a filamentary structure of IC 348. We find that the overall field tends to be more perpendicular than parallel to the filamentary structure of the region. The polarization fraction decreases with intensity, and we estimate the trend by power-law and the mean of the Rice distribution fittings. The power indices for the cores are much smaller than 1, indicative of possible grain growth to micron size in the cores. We also measure the magnetic field strengths of the two cores and the filamentary area separately by applying the Davis-Chandrasekhar-Fermi method and its alternative version for compressed medium. The estimated mass-to-flux ratios are 0.45-2.20 and 0.63-2.76 for HH 211 MMS and IC 348 MMS, respectively, while the ratios for the filament is 0.33-1.50. This result may suggest that the transition from subcritical to supercritical conditions occurs at the core scale (\\(\\sim\\) 0.05 pc) in the region. In addition, we study the energy balance of the cores and find that the relative strength of turbulence to the magnetic field tends to be stronger for IC 348 MMS than HH 211 MMS. The result could potentially explain the different configurations inside the two cores: a single protostellar system in HH 211 MMS and multiple protostars in IC 348 MMS.
Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-Mass Star-Forming Region NGC2264 : Global Properties and Local Magnetogravitational Configurations
2024
We report 850 \\(\\mu\\)m continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of the B-fields In STar forming Regions Observations (BISTRO) large program on the James Clerk Maxwell Telescope (JCMT). These data reveal a well-structured non-uniform magnetic field in the NGC 2264C and 2264D regions with a prevailing orientation around 30 deg from north to east. Field strengths estimates and a virial analysis for the major clumps indicate that NGC 2264C is globally dominated by gravity while in 2264D magnetic, gravitational, and kinetic energies are roughly balanced. We present an analysis scheme that utilizes the locally resolved magnetic field structures, together with the locally measured gravitational vector field and the extracted filamentary network. From this, we infer statistical trends showing that this network consists of two main groups of filaments oriented approximately perpendicular to one another. Additionally, gravity shows one dominating converging direction that is roughly perpendicular to one of the filament orientations, which is suggestive of mass accretion along this direction. Beyond these statistical trends, we identify two types of filaments. The type-I filament is perpendicular to the magnetic field with local gravity transitioning from parallel to perpendicular to the magnetic field from the outside to the filament ridge. The type-II filament is parallel to the magnetic field and local gravity. We interpret these two types of filaments as originating from the competition between radial collapsing, driven by filament self-gravity, and the longitudinal collapsing, driven by the region's global gravity.
The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-Forming Region
by
Kanamori, Yoshihiro
,
Mairs, Steve
,
Parsons, Harriet
in
Ammonia
,
Depolarization
,
Linear polarization
2019
We present the POL-2 850 \\(\\mu\\)m linear polarization map of the Barnard 1 clump in the Perseus molecular cloud complex from the B-fields In STar-forming Region Observations (BISTRO) survey at the James Clerk Maxwell Telescope. We find a trend of decreasing polarization fraction as a function of total intensity, which we link to depolarization effects towards higher density regions of the cloud. We then use the polarization data at 850 \\(\\mu\\)m to infer the plane-of-sky orientation of the large-scale magnetic field in Barnard 1. This magnetic field runs North-South across most of the cloud, with the exception of B1-c where it turns more East-West. From the dispersion of polarization angles, we calculate a turbulence correlation length of \\(5.0 \\pm 2.5\\) arcsec (\\(1500\\) au), and a turbulent-to-total magnetic energy ratio of \\(0.5 \\pm 0.3\\) inside the cloud. We combine this turbulent-to-total magnetic energy ratio with observations of NH\\(_3\\) molecular lines from the Green Bank Ammonia Survey (GAS) to estimate the strength of the plane-of-sky component of the magnetic field through the Davis-Chandrasekhar-Fermi method. With a plane-of-sky amplitude of \\(120 \\pm 60\\) \\(\\mu\\)G and a criticality criterion \\(\\lambda_c = 3.0 \\pm 1.5\\), we find that Barnard 1 is a supercritical molecular cloud with a magnetic field nearly dominated by its turbulent component.
JCMT BISTRO survey: Magnetic Fields within the Hub-Filament Structure in IC 5146
2019
We present the 850 \\(\\mu\\)m polarization observations toward the IC5146 filamentary cloud taken using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and its associated polarimeter (POL-2), mounted on the James Clerk Maxwell Telescope (JCMT), as part of the B-fields In STar forming Regions Observations (BISTRO). This work is aimed at revealing the magnetic field morphology within a core-scale (\\(\\lesssim 1.0\\) pc) hub-filament structure (HFS) located at the end of a parsec-scale filament. To investigate whether or not the observed polarization traces the magnetic field in the HFS, we analyze the dependence between the observed polarization fraction and total intensity using a Bayesian approach with the polarization fraction described by the Rice likelihood function, which can correctly describe the probability density function (PDF) of the observed polarization fraction for low signal-to-noise ratio (SNR) data. We find a power-law dependence between the polarization fraction and total intensity with an index of 0.56 in \\(A_V\\sim\\) 20--300 mag regions, suggesting that the dust grains in these dense regions can still be aligned with magnetic fields in the IC5146 regions. Our polarization maps reveal a curved magnetic field, possibly dragged by the contraction along the parsec-scale filament. We further obtain a magnetic field strength of 0.5\\(\\pm\\)0.2 mG toward the central hub using the Davis-Chandrasekhar-Fermi method, corresponding to a mass-to-flux criticality of \\(\\sim\\) \\(1.3\\pm0.4\\) and an Alfv\\'{e}nic Mach number of \\(<\\)0.6. These results suggest that gravity and magnetic field is currently of comparable importance in the HFS, and turbulence is less important.
The JCMT and Herschel Gould Belt Surveys: A comparison of SCUBA-2 and Herschel data of dense cores in the Taurus dark cloud L1495
2016
We present a comparison of SCUBA-2 850-\\(\\mu\\)m and Herschel 70--500-\\(\\mu\\)m observations of the L1495 filament in the Taurus Molecular Cloud with the goal of characterising the SCUBA-2 Gould Belt Survey (GBS) data set. We identify and characterise starless cores in three data sets: SCUBA-2 850-\\(\\mu\\)m, Herschel 250-\\(\\mu\\)m, and Herschel 250-\\(\\mu\\)m spatially filtered to mimic the SCUBA-2 data. SCUBA-2 detects only the highest-surface-brightness sources, principally detecting protostellar sources and starless cores embedded in filaments, while Herschel is sensitive to most of the cloud structure, including extended low-surface-brightness emission. Herschel detects considerably more sources than SCUBA-2 even after spatial filtering. We investigate which properties of a starless core detected by Herschel determine its detectability by SCUBA-2, and find that they are the core's temperature and column density (for given dust properties). For similar-temperature cores, such as those seen in L1495, the surface brightnesses of the cores are determined by their column densities, with the highest-column-density cores being detected by SCUBA-2. For roughly spherical geometries, column density corresponds to volume density, and so SCUBA-2 selects the densest cores from a population at a given temperature. This selection effect, which we quantify as a function of distance, makes SCUBA-2 ideal for identifying those cores in Herschel catalogues that are closest to forming stars. Our results can now be used by anyone wishing to use the SCUBA-2 GBS data set.
First results from BISTRO -- a SCUBA-2 polarimeter survey of the Gould Belt
2017
We present the first results from the B-fields In STar-forming Region Observations (BISTRO) survey, using the Sub-millimetre Common-User Bolometer Array 2 (SCUBA-2) camera, with its associated polarimeter (POL-2), on the James Clerk Maxwell Telescope (JCMT) in Hawaii. We discuss the survey's aims and objectives. We describe the rationale behind the survey, and the questions which the survey will aim to answer. The most important of these is the role of magnetic fields in the star formation process on the scale of individual filaments and cores in dense regions. We describe the data acquisition and reduction processes for POL-2, demonstrating both repeatability and consistency with previous data. We present a first-look analysis of the first results from the BISTRO survey in the OMC 1 region. We see that the magnetic field lies approximately perpendicular to the famous 'integral filament' in the densest regions of that filament. Furthermore, we see an 'hour-glass' magnetic field morphology extending beyond the densest region of the integral filament into the less-dense surrounding material, and discuss possible causes for this. We also discuss the more complex morphology seen along the Orion Bar region. We examine the morphology of the field along the lower-density north-eastern filament. We find consistency with previous theoretical models that predict magnetic fields lying parallel to low-density, non-self-gravitating filaments, and perpendicular to higher-density, self-gravitating filaments.