Racial Disparity in Length of Stay Following Implementation of a Bariatric Enhanced Recovery Program.

INTRODUCTION: Enhanced Recovery Programs (ERPs) mitigate racial disparities in postoperative length of stay (LOS) for colorectal populations. It is unclear, however, if these effects exist in the bariatric surgery population. Therefore, this study aimed to evaluate the racial disparities in LOS before and after implementation of bariatric surgery ERP. METHODS: A retrospective cohort study was performed using data from a single institution. Patients undergoing minimally invasive sleeve gastrectomy or Roux-en-Y gastric bypass from 2017 to 2019 (pre-ERP) or 2020-2022 (ERP) were included. Chi-square, Kruskal-Wallis, and analysis of variance were used to compare groups, and estimated LOS (eLOS) was assessed via multivariable regression. RESULTS: Seven hundred sixty four patients were identified, including 363 pre-ERPs and 401 ERPs. Pre-ERP and ERP cohorts were similar in age (median 44.3 years versus 43.8 years, P = 0.80), race (53.4% Black versus 56.4% Black, P = 0.42), and preoperative body mass index (median 48.3 versus 49.4, P = 0.14). Overall median LOS following bariatric surgery decreased from 2 days pre-ERP to 1 day following ERP (P < 0.001). Average LOS for Black and White patients decreased by 0.5 and 0.48 days, respectively. However, overall eLOS remained greater for Black patients compared with White patients despite ERP implementation (eLOS 0.21 days, P = 0.01). CONCLUSIONS: Implementation of a bariatric surgery ERP was associated with decreased LOS for both Black and White patients. However, Black patients did have slightly longer LOS than White patients in both pre-ERP and ERP eras. More work is needed to understand the driving mechanism(s) of these disparities to eliminate them.

Readability of patient education materials for bariatric surgery.

INTRODUCTION: Bariatric surgery is a successful treatment for obesity, but barriers to surgery exist, including low health literacy. National organizations recommend patient education materials (PEM) not exceed a sixth-grade reading level. Difficult to comprehend PEM can exacerbate barriers to bariatric surgery, especially in the Deep South where high obesity and low literacy rates exist. This study aimed to assess and compare the readability of webpages and electronic medical record (EMR) bariatric surgery PEM from one institution. METHODS: Readability of online bariatric surgery and standardized perioperative EMR PEM were analyzed and compared. Text readability was assessed by validated instruments: Flesch Reading Ease Formula (FRE), Flesch Kincaid Grade Level (FKGL), Gunning Fog (GF), Coleman-Liau Index (CL), Simple Measure of Gobbledygook (SMOG), Automated Readability Index (ARI), and Linsear Write Formula (LWF). Mean readability scores were calculated with standard deviations and compared using unpaired t-tests. RESULTS: 32 webpages and seven EMR education documents were analyzed. Webpages were overall "difficult to read" compared to "standard/average" readability EMR materials (mean FRE 50.5 ± 18.3 vs. 67.4 ± 4.2, p = 0.023). All webpages were at or above high school reading level: mean FKGL 11.8 ± 4.4, GF 14.0 ± 3.9, CL 9.5 ± 3.2, SMOG 11.0 ± 3.2, ARI 11.7 ± 5.1, and LWF 14.9 ± 6.6. Webpages with highest reading levels were nutrition information and lowest were patient testimonials. EMR materials were sixth to ninth grade reading level: FKGL 6.2 ± 0.8, GF 9.3 ± 1.4, CL 9.7 ± 0.9, SMOG 7.1 ± 0.8, ARI 6.1 ± 1.0, and LWF 5.9 ± 0.8. CONCLUSION: Surgeon curated bariatric surgery webpages have advanced reading levels above recommended thresholds compared to standardized PEM from an EMR. This readability gap may unintentionally contribute to barriers to surgery and affect postoperative outcomes. Streamlined efforts are needed to create materials that are easier to read and comply with recommendations.

The University of Alabama at Birmingham Surgery Community Network: Tackling the Challenges of Rural Surgery.

Over the past 5 years, The University of Alabama at Birmingham (UAB) Department of Surgery has taken a keen interest in the practice of surgery in rural Alabama and has established the UAB surgery community network. Our goal is to improve the delivery of surgical care in rural areas through active recruitment of rural surgeons, the development of research around rural surgery practice, and the expansion of a surgery network throughout the state. Here, we will present the challenges faced by rural surgery, our early work to address these challenges, and offer a plan for moving forward.

Reduced penetrance of MODY-associated HNF1A/HNF4A variants but not GCK variants in clinically unselected cohorts.

The true prevalence and penetrance of monogenic disease variants are often not known because of clinical-referral ascertainment bias. We comprehensively assess the penetrance and prevalence of pathogenic variants in HNF1A, HNF4A, and GCK that account for >80% of monogenic diabetes. We analyzed clinical and genetic data from 1,742 clinically referred probands, 2,194 family members, clinically unselected individuals from a US health system-based cohort (n = 132,194), and a UK population-based cohort (n = 198,748). We show that one in 1,500 individuals harbor a pathogenic variant in one of these genes. The penetrance of diabetes for HNF1A and HNF4A pathogenic variants was substantially lower in the clinically unselected individuals compared to clinically referred probands and was dependent on the setting (32% in the population, 49% in the health system cohort, 86% in a family member, and 98% in probands for HNF1A). The relative risk of diabetes was similar across the clinically unselected cohorts highlighting the role of environment/other genetic factors. Surprisingly, the penetrance of pathogenic GCK variants was similar across all cohorts (89%-97%). We highlight that pathogenic variants in HNF1A, HNF4A, and GCK are not ultra-rare in the population. For HNF1A and HNF4A, we need to tailor genetic interpretation and counseling based on the setting in which a pathogenic monogenic variant was identified. GCK is an exception with near-complete penetrance in all settings. This along with the clinical implication of diagnosis makes it an excellent candidate for the American College of Medical Genetics secondary gene list.

A Genome-First Approach to Characterize DICER1 Pathogenic Variant Prevalence, Penetrance, and Phenotype.

Importance: Genetic disorders are historically defined through phenotype-first approaches. However, risk estimates derived from phenotype-linked ascertainment may overestimate severity and penetrance. Pathogenic variants in DICER1 are associated with increased risks of rare and common neoplasms and thyroid disease in adults and children. This study explored how effectively a genome-first approach could characterize the clinical traits associated with germline DICER1 putative loss-of-function (pLOF) variants in an unselected clinical cohort. Objective: To examine the prevalence, penetrance, and phenotypic characteristics of carriers of germline DICER1 pLOF variants via genome-first ascertainment. Design, Setting, and Participants: This cohort study classifies DICER1 variants in germline exome sequence data from 92 296 participants of the Geisinger MyCode Community Health Initiative. Data for each MyCode participant were used from the start of the Geisinger electronic health record to February 1, 2018. Main Outcomes and Measures: Prevalence of germline DICER1 variation; penetrance of malignant tumors and thyroid disease in carriers of germline DICER1 variation; structured, manual review of electronic health records; and DICER1 sequencing of available tumors from an associated cancer registry. Results: A total of 92 296 adults (mean [SD] age, 59 [18] years; 98% white; 60% female) participated in the study. Germline DICER1 pLOF variants were observed in 1 in 3700 to 1 in 4600 participants, more than double the expected prevalence. Malignant tumors (primarily thyroid carcinoma) were observed in 4 of 25 participants (16%) with DICER1 pLOF variants, which is comparable (by 50 years of age) to the frequency of neoplasms in the largest registry- and clinic-based (phenotype-first) DICER1 studies published to date. DICER1 pLOF variants were significantly associated with risks of thyroidectomy (odds ratio [OR], 6.0; 95% CI, 2.2-16.3; P = .007) and thyroid cancer (OR, 9.2; 95% CI, 2.1-34.7; P = .02) compared with controls, but there was not a significant increase in the risk of goiter (OR, 1.8; 95% CI, 0.7-4.9). A female patient in her 80s who was a carrier of a germline DICER1 hotspot variant was apparently healthy on electronic health record review. The term DICER1 did not appear in any of the medical records of the 25 participants with a pLOF DICER1 variant, even in those affected with a known DICER1-associated tumor or thyroid phenotype. Conclusions and Relevance: This cohort study was able to ascertain individuals with germline DICER1 variants based on a genome-first approach rather than through a previously established DICER1-related phenotype. Use of the genome-first approach may complement more traditional approaches to syndrome delineation and may be an efficient approach for risk estimation.

Color lens-free imaging using multi-wavelength illumination based phase retrieval.

Accurate image reconstruction in color lens-free imaging has proven challenging. The color image reconstruction of a sample is impacted not only by how strongly the illumination intensity is absorbed at a given spectral range, but also by the lack of phase information recorded on the image sensor. We present a compact and cost-effective approach of addressing the need for phase retrieval to enable robust color image reconstruction in lens-free imaging. The amplitude images obtained at transparent wavelength bands are used to estimate the phase in highly absorbed wavelength bands. The accurate phase information, obtained through our iterative algorithm, removes the color artefacts due to twin-image noise in the reconstructed image and improves image reconstruction quality to allow accurate color reconstruction. This could enable the technique to be applied for imaging of stained pathology slides, an important tool in medical diagnostics.

Fast compressive lens-free tomography for 3D biological cell culture imaging.

We present a compressive lens-free technique that performs tomographic imaging across a cubic millimeter-scale volume from highly sparse data. Compared with existing lens-free 3D microscopy systems, our method requires an order of magnitude fewer multi-angle illuminations for tomographic reconstruction, leading to a compact, cost-effective and scanning-free setup with a reduced data acquisition time to enable high-throughput 3D imaging of dynamic biological processes. We apply a fast proximal gradient algorithm with composite regularization to address the ill-posed tomographic inverse problem. Using simulated data, we show that the proposed method can achieve a reconstruction speed ∼10× faster than the state-of-the-art inverse problem approach in 3D lens-free microscopy. We experimentally validate the effectiveness of our method by imaging a resolution test chart and polystyrene beads, demonstrating its capability to resolve micron-size features in both lateral and axial directions. Furthermore, tomographic reconstruction results of neuronspheres and intestinal organoids reveal the potential of this 3D imaging technique for high-resolution and high-throughput biological applications.

Pixel super-resolution for lens-free holographic microscopy using deep learning neural networks.

Lens-free holographic microscopy (LFHM) provides a cost-effective tool for large field-of-view imaging in various biomedical applications. However, due to the unit optical magnification, its spatial resolution is limited by the pixel size of the imager. Pixel super-resolution (PSR) technique tackles this problem by using a series of sub-pixel shifted low-resolution (LR) lens-free holograms to form the high-resolution (HR) hologram. Conventional iterative PSR methods require a large number of measurements and a time-consuming reconstruction process, limiting the throughput of LFHM in practice. Here we report a deep learning-based PSR approach to enhance the resolution of LFHM. Compared with the existing PSR methods, our neural network-based approach outputs the HR hologram in an end-to-end fashion and maintains consistency in resolution improvement with a reduced number of LR holograms. Moreover, by exploiting the resolution degradation model in the imaging process, the network can be trained with a data set synthesized from the LR hologram itself without resorting to the HR ground truth. We validated the effectiveness and the robustness of our method by imaging various types of samples using a single network trained on an entirely different data set. This deep learning-based PSR approach can significantly accelerate both the data acquisition and the HR hologram reconstruction processes, therefore providing a practical solution to fast, lens-free, super-resolution imaging.

Genomics-First Evaluation of Heart Disease Associated With Titin-Truncating Variants.

BACKGROUND: Truncating variants in the Titin gene (TTNtvs) are common in individuals with idiopathic dilated cardiomyopathy (DCM). However, a comprehensive genomics-first evaluation of the impact of TTNtvs in different clinical contexts, and the evaluation of modifiers such as genetic ancestry, has not been performed. METHODS: We reviewed whole exome sequence data for >71 000 individuals (61 040 from the Geisinger MyCode Community Health Initiative (2007 to present) and 10 273 from the PennMedicine BioBank (2013 to present) to identify anyone with TTNtvs. We further selected individuals with TTNtvs in exons highly expressed in the heart (proportion spliced in [PSI] >0.9). Using linked electronic health records, we evaluated associations of TTNtvs with diagnoses and quantitative echocardiographic measures, including subanalyses for individuals with and without DCM diagnoses. We also reviewed data from the Jackson Heart Study to validate specific analyses for individuals of African ancestry. RESULTS: Identified with a TTNtv in a highly expressed exon (hiPSI) were 1.2% individuals in PennMedicine BioBank and 0.6% at Geisinger. The presence of a hiPSI TTNtv was associated with increased odds of DCM in individuals of European ancestry (odds ratio [95% CI]: 18.7 [9.1-39.4] {PennMedicine BioBank} and 10.8 [7.0-16.0] {Geisinger}). hiPSI TTNtvs were not associated with DCM in individuals of African ancestry, despite a high DCM prevalence (odds ratio, 1.8 [0.2-13.7]; P=0.57). Among 244 individuals of European ancestry with DCM in PennMedicine BioBank, hiPSI TTNtv carriers had lower left ventricular ejection fraction (ß=-12%, P=3×10-7), and increased left ventricular diameter (ß=0.65 cm, P=9×10-3). In the Geisinger cohort, hiPSI TTNtv carriers without a cardiomyopathy diagnosis had more atrial fibrillation (odds ratio, 2.4 [1.6-3.6]) and heart failure (odds ratio, 3.8 [2.4-6.0]), and lower left ventricular ejection fraction (ß=-3.4%, P=1×10-7). CONCLUSIONS: Individuals of European ancestry with hiPSI TTNtv have an abnormal cardiac phenotype characterized by lower left ventricular ejection fraction, irrespective of the clinical manifestation of cardiomyopathy. Associations with arrhythmias, including atrial fibrillation, were observed even when controlling for cardiomyopathy diagnosis. In contrast, no association between hiPSI TTNtvs and DCM was discerned among individuals of African ancestry. Given these findings, clinical identification of hiPSI TTNtv carriers may alter clinical management strategies.

Cytomegalovirus promotes intestinal macrophage-mediated mucosal inflammation through induction of Smad7.

Intestinal macrophages in healthy human mucosa are profoundly down-regulated for inflammatory responses (inflammation anergy) due to stromal TGF-ß inactivation of NF-κB. Paradoxically, in cytomegalovirus (CMV) intestinal inflammatory disease, one of the most common manifestations of opportunistic CMV infection, intestinal macrophages mediate severe mucosal inflammation. Here we investigated the mechanism whereby CMV infection promotes macrophage-mediated mucosal inflammation. CMV infected primary intestinal macrophages but did not replicate in the cells or reverse established inflammation anergy. However, CMV infection of precursor blood monocytes, the source of human intestinal macrophages in adults, prevented stromal TGF-ß-induced differentiation of monocytes into inflammation anergic macrophages. Mechanistically, CMV up-regulated monocyte expression of the TGF-ß antagonist Smad7, blocking the ability of stromal TGF-ß to inactivate NF-κB, thereby enabling MyD88 and NF-κB-dependent cytokine production. Smad7 expression also was markedly elevated in mucosal tissue from subjects with CMV colitis and declined after antiviral ganciclovir therapy. Confirming these findings, transfection of Smad7 antisense oligonucleotide into CMV-infected monocytes restored monocyte susceptibility to stromal TGF-ß-induced inflammation anergy. Thus, CMV-infected monocytes that recruit to the mucosa, not resident macrophages, are the source of inflammatory macrophages in CMV mucosal disease and implicate Smad7 as a key regulator of, and potential therapeutic target for, CMV mucosal disease.

Reflective lens-free imaging on high-density silicon microelectrode arrays for monitoring and evaluation of in vitro cardiac contractility.

The high rate of drug attrition caused by cardiotoxicity is a major challenge for drug development. Here, we developed a reflective lens-free imaging (RLFI) approach to non-invasively record in vitro cell deformation in cardiac monolayers with high temporal (169 fps) and non-reconstructed spatial resolution (352 µm) over a field-of-view of maximally 57 mm2. The method is compatible with opaque surfaces and silicon-based devices. Further, we demonstrated that the system can detect the impairment of both contractility and fast excitation waves in cardiac monolayers. Additionally, the RLFI device was implemented on a CMOS-based microelectrode array to retrieve multi-parametric information of cardiac cells, thereby offering more in-depth analysis of drug-induced (cardiomyopathic) effects for preclinical cardiotoxicity screening applications.

Insurance-mandated preoperative diet and outcomes after bariatric surgery.

BACKGROUND: Despite a lack of demonstrated patient benefit, many insurance providers mandate a physician-supervised diet before financial coverage for bariatric surgery. OBJECTIVES: To compare weight loss between patients with versus without insurance mandating a preoperative diet. SETTING: University hospital, United States. METHODS: Retrospective study of all patients who underwent laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy over a 5-year period, stratified based on whether an insurance-mandated physician-supervised diet was required. Weight loss outcomes at 6, 12, and 24 months postoperation were compared. Linear mixed-models and backward-stepwise selection were used. P<0.05 was considered significant. RESULTS: Of 284 patients, 225 (79%) were required and 59 (21%) were not required to complete a preoperative diet by their insurance provider. Patients without the requirement had a shorter time to operation from initial consultation (P = .04), were older (P<.01), and were more likely to have government-sponsored insurance (P<.01). There was no difference in preoperative weight or body mass index or co-morbidities. In unadjusted models, percent excess weight loss was superior in the group without an insurance-mandated diet at 12 (P = .050) and 24 (P = .045) months. In adjusted analyses, this group also had greater percent excess weight loss at 6 (P<.001), 12 (P<.001), and 24 (P<.001) months; percent total weight loss at 24 months (P = .004); and change in body mass index at 6 (P = .032) and 24 (P = .007) months. There was no difference in length of stay or complication rates. CONCLUSIONS: Insurance-mandated preoperative diets delay treatment and may lead to inferior weight loss.

Predictive factors of weight regain following laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Strategies to address weight recidivism following Roux-en-Y gastric bypass (RYGB) could be developed if patients at risk were identified in advance. This study aimed to determine factors that predict weight regain. METHODS: Retrospective review was performed of patients who underwent laparoscopic RYGB at a single institution over 10 years. Group-based modeling was used to estimate trajectories of weight regain after nadir and stratify patients based on percent weight change (%WC). RESULTS: Three trajectories were identified from 586 patients: 121 had ongoing weight loss, 343 were weight stable, and 122 regained weight. Male sex (p = 0.020) and white race (p < 0.001) were associated with stable weight or weight regain. Being from a neighborhood of socioeconomic advantage (p = 0.035) was associated with weight regain. Patients with weight regain experienced improved percent weight loss (%WL) at nadir (p < 0.001) and ΔBMI (p = 0.002), yet they had higher weight and BMI and lower %WL and ΔBMI than the other two groups during long-term follow-up. On multivariate analyses, those who regained weight were more likely from socioeconomically advantaged neighborhoods (OR 1.82, CI 1.18-2.79). CONCLUSIONS: Several patient-related characteristics predicted an increased likelihood of weight regain. Further studies are needed to elucidate how these factors contribute to weight recidivism following bariatric surgery.

Time-lapse lens-free imaging of cell migration in diverse physical microenvironments.

Time-lapse imaging of biological samples is important for understanding complex (patho)physiological processes. A growing number of point-of-care biomedical assays rely on real-time imaging of flowing or migrating cells. However, the cost and complexity of integrating experimental models simulating physiologically relevant microenvironments with bulky imaging systems that offer sufficient spatiotemporal resolution limit the use of time-lapse assays in research and clinical settings. This paper introduces a compact and affordable lens-free imaging (LFI) device based on the principle of coherent in-line, digital holography for time-lapse cell migration assays. The LFI device combines single-cell resolution (1.2 µm) with a large field of view (6.4 × 4.6 mm(2)), thus rendering it ideal for high-throughput applications and removing the need for expensive and bulky programmable motorized stages. The set-up is so compact that it can be housed in a standard cell culture incubator, thereby avoiding custom-built stage top incubators. LFI is thoroughly benchmarked against conventional live-cell phase contrast microscopy for random cell motility on two-dimensional (2D) surfaces and confined migration on 1D-microprinted lines and in microchannels using breast adenocarcinoma cells. The quality of the results obtained by the two imaging systems is comparable, and they reveal that cells migrate more efficiently upon increasing confinement. Interestingly, assays of confined migration more readily distinguish the migratory potential of metastatic MDA-MB-231 cells from non-metastatic MCF7 cells relative to traditional 2D migration assays. Altogether, this single-cell migration study establishes LFI as an elegant and useful tool for live-cell imaging.

Outcomes associated with preoperative weight loss after laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) is an effective treatment for achieving and maintaining weight loss and for improving obesity-related comorbidities. As part of the approval process for bariatric surgery, many insurance companies require patients to have documented recent participation in a supervised weight loss program. The goal of this study was to evaluate the relationship of preoperative weight changes with outcomes following LRYGB. METHODS: A retrospective review was conducted of adult patients undergoing LRYGB between 2008 and 2012 at a single institution. Patients were stratified into quartiles based on % excess weight gain (0-4.99 % and ≥5 % EWG) and % excess weight loss (0-4.99 % and ≥5 % EWL). Generalized linear models were used to examine differences in postoperative weight outcomes at 6, 12, and 24 months. Covariates included in the final adjusted models were determined using backwards stepwise selection. RESULTS: Of the 300 patients included in the study, there were no significant demographic differences among the quartiles. However, there was an increased time to operation for patients who gained or lost ≥5 % excess body weight (p < 0.001). Although there was no statistical significance in postoperative complications, there was a higher rate of complications in patients with ≥5 % EWG compared to those with ≥5 % EWL (12.5 vs. 4.8 %, respectively; p = 0.29). Unadjusted and adjusted generalized linear models showed no statistically significant association between preoperative % excess weight change and weight loss outcomes at 24 months. CONCLUSION: Patients with the greatest % preoperative excess weight change had the longest intervals from initial visit to operation. No significant differences were seen in perioperative and postoperative outcomes. This study suggests preoperative weight loss requirements may delay the time to operation without improving postoperative outcomes or weight loss.

The cell size and distribution of adipocytes from subcutaneous and visceral fat is associated with type 2 diabetes mellitus in humans.

AIMS/HYPOTHESIS: Regional deposition of adipose tissue and adipocyte morphology may contribute to increased risk for insulin resistance. The aim of this study was to compare adipocyte cell size and size distribution from multiple fat depots and to determine the association with type 2 diabetes mellitus, anthropomorphic data, and subjects' metabolic profile. METHODS: Clinical data and adipose tissue from subcutaneous fat, omentum, and mesentery were collected from 30 subjects with morbid obesity. Adipocytes were isolated by collagenase digestion and sized by microscopic measurement of cell diameter. RESULTS: Overall, adipocytes from subcutaneous fat were larger than those from omentum or mesentery. For the subcutaneous and omental fat depots, there was a significant increase in % small cells (14.9% vs 31.4%, p = 0 .006 and 14.0% vs 30.5%, p = 0 .015, respectively) and corresponding decrease in % large cells for nondiabetic vs diabetic patients. There was a similar trend for mesentery but it did not reach statistical significance (p = 0 .090). For omentum and mesentery, there was also a significant decrease in the diameter of the small cells. Fasting glucose was positively correlated with fraction of small cells in omentum and mesentery, and HbA1C was positively correlated with fraction of small cells in the omental fat depot. There was no correlation between large cell diameter with clinical parameters in any of the fat depots. CONCLUSIONS/INTERPRETATION: These results indicate size distribution of adipocytes, specifically an increase in the fraction of small cells, is associated with the presence of type 2 diabetes mellitus.

Association of race and socioeconomic status with outcomes following laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Obesity poses serious health consequences, and bariatric surgery remains the most effective and durable treatment. The goal of this study was to identify the association of race and socioeconomic characteristics with clinical outcomes following laparoscopic Roux-en-Y gastric bypass (LRYGB). METHODS: A retrospective review of all patients who underwent LRYGB between 2004 and 2010 was conducted. Outcomes analyzed included percent excess weight loss (%EWL), percent weight loss (%WL), change in body mass index (ΔBMI), and improvement or remission of obesity-associated medical conditions. RESULTS: In total, 663 patients met inclusion criteria with 170 (25.6%) African Americans and 493 (74.4%) European Americans. When compared to European Americans, the African American group included significantly more women and had a significantly higher preoperative BMI and lower socioeconomic status. In adjusted analyses, African Americans had significantly lower %EWL, %WL, and ΔBMI than the European Americans at 1-, 2-, and 5-year intervals of follow-up. Adjusted spline models including all follow-up visits for all patients also demonstrated a significant difference between the races in %EWL, %WL, and ΔBMI. Both races had similar improvement or remission of type 2 diabetes mellitus, obstructive sleep apnea, hyperlipidemia, and hypertension. CONCLUSION: Although African Americans had a statistically significant lower %EWL, %WL, and ΔBMI, both groups had durable weight loss and comparable rates of improvement or remission of obesity-associated comorbidities. Thus, both groups have significant improvement in their overall health after LRYGB.

Three-part differential of unlabeled leukocytes with a compact lens-free imaging flow cytometer.

A compelling clinical need exists for inexpensive, portable haematology analyzers that can be utilized at the point-of-care in emergency settings or in resource-limited settings. Development of a label-free, microfluidic blood analysis platform is the first step towards such a miniaturized, cost-effective system. Here we assemble a compact lens-free in-line holographic microscope and employ it to image blood cells flowing in a microfluidic chip, using a high-speed camera and stroboscopic illumination. Numerical reconstruction of the captured holograms allows classification of unlabeled leukocytes into three main subtypes: lymphocytes, monocytes and granulocytes. A scale-space recognition analysis to evaluate cellular size and internal complexity is also developed and used to build a 3-part leukocyte differential. The lens-free image-based classification is compared to the 3-part white blood cell differential generated by using a conventional analyzer on the same blood sample and is found to be in good agreement with it.