Faculty Bibliography

Purpose: Roux-en-Y gastric bypass (RYGB) leads to the improvement of many obesity-associated conditions. The degree to which post-operative macronutrient composition contributes to metabolic improvement after RYGB is understudied. Methods: A mouse model of RYGB was used to examine the effects of diet on the post-operative outcomes of RYGB. Obese mice underwent either Sham or RYGB surgery and were administered either chow or HFD and then monitored for an additional 8 weeks. Results: After RYGB, reductions to body weight, fat mass, and lean mass were similar regardless of diet. RYGB and HFD were independently detrimental to bone mineral density and plasma vitamin D levels. Independent of surgery, HFD accelerated hematopoietic stem and progenitor cell proliferation and differentiation and exhibited greater myeloid lineage commitment. Independent of diet, systemic iron deficiency was present after RYGB. In both Sham and RYGB groups, HFD increased energy expenditure. RYGB increased fecal energy loss, and HFD after RYGB increased fecal lipid content. RYGB lowered fasting glucose and liver glycogen levels but HFD had an opposing effect. Indices of insulin sensitivity improved independent of diet. HFD impaired improvements to dyslipidemia, NAFLD, and fibrosis. Conclusion: Post-operative diet plays a significant role in determining the degree to which RYGB reverses obesity-induced metabolic abnormalities such as hyperglycemia, dyslipidemia, and NAFLD. Diet composition may be targeted in order to assist in the treatment of post-RYGB bone mineral density loss and vitamin D deficiency as well as to reverse myeloid lineage commitment. HFD after RYGB continues to pose a significant multidimensional health risk. Graphical Abstract: [Figure not available: see fulltext.].

The original article has been corrected to replace the Electronic Supplemental Material.

INTRODUCTION/BACKGROUND:Surgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells. MATERIALS AND METHODS/METHODS:A retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed. RESULTS:After excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs. All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains). Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs. CONCLUSION/CONCLUSIONS:Grade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.

PURPOSE/OBJECTIVE:Bariatric surgery is emerging as an effective treatment for obesity and the metabolic syndrome. Recently, we demonstrated that Roux-en-Y gastric bypass (RYGB), but not vertical sleeve gastrectomy (VSG), resulted in improvements to white adipose physiology and enhanced brown adipose functioning. Since beneficial alterations to liver health are also expected after bariatric surgery, comparing the post-operative effects of RYGB and VSG on liver physiology is essential to their application in the treatment of non-alcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS/METHODS:The effects of RYGB and VSG on liver physiology were compared using diet induced mouse model of obesity. High-fat diet (HFD) was administered for 12 weeks after surgery and alterations to liver physiology were assessed. RESULTS:Both RYGB and VSG showed decreased liver weight as well as reductions to hepatic cholesterol and triglyceride levels. There were demonstrable improvements to NAFLD activity score (NAS) and fibrosis stage scoring after both surgeries. In RYGB, these beneficial changes to liver function resulted from the downregulation of pro-fibrotic and upregulation anti-fibrotic genes, as well as increased fatty acid oxidation and bile acid flux. For VSG, though similar alterations were observed, they were less potent. However, VSG did significantly downregulate pro-fibrotic genes and showed increased glycogen content paralleled by decreased glycogenolysis which may have contributed to the resolution of NAFLD. CONCLUSION/CONCLUSIONS:RYGB and VSG improve liver physiology and function, but RYGB is more efficacious. Resolutions of NAFLD in RYGB and VSG are achieved through different processes, independent of weight loss.

INTRODUCTION/BACKGROUND:Barrett's esophagus (BE) is a premalignant condition that leads to susceptibility to developing adenocarcinoma. The most common endoscopic surveillance technique is forceps biopsy, which involves sampling the specimen every 1 to 2 cm along the length of the lesion. This technique has a low sensitivity and often leaves the majority of the esophageal mucosa untested. Recently, the use of wide-area transepithelial sampling with computer-assisted 3-dimensional analysis (WATS-3D) has received much attention. However, there is little known about this novel technique, and this research aims to add to our knowledge of WATS-3D by comparing it to traditional forceps biopsy. MATERIALS AND METHODS/METHODS:A retrospective observational study was performed. All existing GI biopsy cases diagnosed with WATS-3D were identified from the institutional pathology databases of NYU Langone Hospital - Long Island from 2019 to 2021. Data collection included patients' age, sex, and dysplasia results. Existing pathology reports and CDx diagnostics were reviewed. All the existing slides of the biopsy cases were pulled out and reviewed. Dysplasia was classified as no dysplasia, indefinite for dysplasia, lowgrade dysplasia, and high-grade dysplasia. RESULTS:A total of 109 cases were included in this study. There are 59 cases diagnosed as BE with forceps biopsy, 72 cases by WATS-3D, and 77 cases by WATS-3D combined with forceps biopsy. The sensitivity of detecting BE was significantly increased by WATS-3D and further by WATS-3D combined with forceps biopsy. In 59 cases diagnosed as BE with forceps biopsy, 50 cases were classified as no dysplasia, 3 cases were indefinite for dysplasia, 5 cases were low-grade dysplasia, and 1 case was high-grade dysplasia. In 72 cases diagnosed as BE by WATS-3D, 64 cases were classified as no dysplasia, 7 cases were indefinite for dysplasia, 1 case was high-grade dysplasia, and no cases with low-grade dysplasia. In 77 cases diagnosed as BE by WATS-3D combined with forceps biopsy, 63 cases were classified as no dysplasia, 8 cases were indefinite for dysplasia, 5 cases with low-grade dysplasia, and 1 case was highgrade dysplasia. The maximal longitudinal extent of the esophageal mucosal changes strongly correlated with the severity of BE. CONCLUSION/CONCLUSIONS:Compared to traditional forceps biopsy, WATS-3D was more sensitive in finding intestinal metaplasia. However, WATS-3D could not clearly discriminate low-grade dysplasia from indefinite for dysplasia and tended to classify low-grade dysplasia as indefinite for dysplasia. The addition of WATS-3D to forceps biopsy resulted in an increase in diagnostic yield and thus an increase in the quality of patient care.

Although coronavirus disease 2019 (COVID-19) is transmitted via respiratory droplets, there are multiple gastrointestinal and hepatic manifestations of the disease, including abnormal liver-associated enzymes. However, there are not many published articles on the pathological findings in the liver of patients with COVID-19. We collected the clinical data from 17 autopsy cases of patients with COVID-19 including age, sex, Body mass index (BMI), liver function test (alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP), direct bilirubin, and total bilirubin), D-dimer, and anticoagulation treatment. We examined histopathologic findings in postmortem hepatic tissue, immunohistochemical (IHC) staining with antibody against COVID-19 spike protein, CD68 and CD61, and electron microscopy. We counted the number of megakaryocytes in liver sections from these COVID-19-positive cases. Abnormal liver-associated enzymes were observed in 12 of 17 cases of COVID-19 infection. With the exception of three cases that had not been tested for D-dimer, all 14 patients' D-dimer levels were increased, including the cases that received varied doses of anticoagulation treatment. Microscopically, the major findings were widespread platelet-fibrin microthrombi, steatosis, histiocytic hyperplasia in the portal tract, mild lobular inflammation, ischemic-type hepatic necrosis, and zone 3 hemorrhage. Rare megakaryocytes were found in sinusoids. COVID-19 IHC demonstrates positive staining of the histiocytes in the portal tract. Under electron microscopy, histiocyte proliferation is present in the portal tract containing lipid droplets, lysosomes, dilated ribosomal endoplasmic reticulum, microvesicular bodies, and coronavirus. The characteristic findings in the liver of patients with COVID-19 include numerous amounts of platelet-fibrin microthrombi, as well as various degrees of steatosis and histiocytic hyperplasia in the portal tract. Possible mechanisms are also discussed.

Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor for type 2 diabetes mellitus, cardiovascular disease, and all-cause mortality. Previously, we demonstrated that lipocalin-type prostaglandin D₂ synthase (L-PGDS) knockout mice show increased glucose intolerance and accelerated atherosclerosis. In the present study, we investigated the role of L-PGDS in mediating NAFLD utilizing L-PGDS knockout (KO) and control C57BL/6 mice fed either low fat (LFD) or high fat diet (HFD) for 14 weeks. Our present study demonstrates that L-PGDS KO mice remain slightly lighter in weight compared to control mice, yet develop NAFLD faster and eventually progress to the more severe non-alcoholic steatohepatitis (NASH). We found increased lipid accumulation in the liver of KO mice over time on both diets, as compared to control mice. The L-PGDS KO mice showed elevated fasting glucose and insulin levels and developed insulin resistance on both LFD and HFD. Lipogenesis marker proteins such as SREBP-1c and LXRα were increased in L-PGDS KO mice after 14 weeks on both diets, when compared to control mice. We replicated our in vivo findings in vitro using HepG2 cells treated with a combination of free fatty acids (oleic and palmitic acid) and exposure to a L-PGDS inhibitor and prostaglandin D₂ receptor (DP1) antagonists. We conclude that the absence or inhibition of L-PGDS results in dyslipidemia, altered expression of lipogenesis genes and the acceleration of NAFLD to NASH, independent of diet and obesity. We propose L-PGDS KO mice as a useful model to explore the pathogenesis of NAFLD and NASH, and L-PGDS as a potential therapeutic target for treatment.

Objectives: We will: 1) describe the WonderLab, a digital health initiative within the New York University Langone Health Department of Child and Adolescent Psychiatry; 2) introduce When to Wonder: Picky Eating, which is the WonderLab's first early childhood mental health digital study; and 3) present preliminary data from this study. Our first objective is to demonstrate how smartphone-based tools developed to assess children in their homes and the use of advanced data analytics can transform how, when, and where we assess young children's development and mental health. Our second objective is to share how our multidisciplinary team and agile development methodology enable us to build and launch a consumer-facing pediatric health app within an academic medical center.
Method(s): The WonderLab creates scalable mobile digital health tools to collect multimodal data in children's homes at the individual, family, and population levels. In December 2018, we released When to Wonder: Picky Eating, a national study with consent, enrollment, study activities, and feedback fully integrated in iOS and Android apps that parents download from the app stores. When to Wonder: Picky Eating focuses on the emotions and behaviors related to picky eating in children under the age of 7 years. Data sources include parent-report, video, audio, and an active task that children and parents play independently to quantify children's food preferences.
Result(s): We will present preliminary data from When to Wonder: Picky Eating to characterize normative and clinically significant emotions and behaviors related to picky eating. We will also share data on recruitment and engagement using social media, app performance, and "lessons learned" about digital pediatric health.
Conclusion(s): We create clinically and scientifically valid digital tools that parents and children want to use. We integrate clinical, scientific, engineering, design, data science, and bioethics expertise with collaborative user engagement and a "build, measure, learn" agile development culture. Our app-based study demonstrates how to build digital health tools that collect and analyze population-level and individual-level, multimodal data about children and families in the home. These new tools and approaches have the potential to transform our engagement with families and our delivery of care. EA, EC, MED
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