bluuebunny/crossref_metadata_2025 huggingface dataset:
SUN-278 Isolated Hypothalamic Langerhans Cell Histiocytosis in an Adult Manifesting as Panhypopituitarism
Authors: Mikhael Alexandra , Gautam Nitesh , Buehler Lauren Anne , Skugor Mario
Published: May 2020

Background: Langerhans Cell Histiocytosis (LCH) is a rare disease characterized by abnormal proliferation of bone marrow derived histiocytes. Although predominantly a childhood disease, LCH can occur at any age and has an incidence of one to two cases per million in adults. LCH can involve a single organ or present as disseminated disease. Sites most commonly affected are bone, skin, bone marrow and pituitary. Isolated hypothalamic LCH is a rare entity. A few reports of LCH presenting as a hypothalamic mass exist but mainly in children. Treatment of adult LCH is derived from pediatric studies, and no standard of care exists. We report a unique case of an adult with panhypopituitarism secondary to a hypothalamic mass found to be biopsy proven isolated LCH treated with Vemurafenib, a BRAF V600E inhibitor.

Clinical Case: A 66-year-old previously healthy man presented with progressively increasing confusion, cognitive decline and generalized weakness requiring hospital admission. Laboratory evaluation revealed an 8AM cortisol of 2.5 ug/dL (reference [ref] 7.0–25.0 ug/dL), ACTH of 9.3 pg/mL (ref 8–42 pg/mL), TSH of 0.106 uIU/mL (ref 0.35–5.5 uIU/mL), free T4 of 0.67 ug/dL (ref 0.7–1.25 ng/dL), LH <0.2 IU/L (ref 0.5–11 IU/L), FSH 0.6 IU/mL (ref 1–12 IU/L), total testosterone <12 ng/dL (ref 193 - 824 ng/dL), free testosterone <3.3 pg mL (ref 41.7 - 180.2 pg/mL), IGF1 41 ng/mL (ref 33–220 ng/mL) and prolactin of 31.5 ng/mL (ref 3.5–15 ng/mL). Findings were consistent with panhypopituitarism, and he was started on glucocorticoid and levothyroxine replacement therapy. MRI pituitary revealed an 18.1 x 13.8 x 15.8 mm hypothalamic mass with signal intensity alteration in the optic pathway. Patient developed polyuria with a serum sodium of 148 mmol/L (ref 136–145 mmol/L), elevated serum osmolality and low urine osmolality consistent with central DI and was started on oral DDAVP.

The patient underwent right sided neuroendoscopic intraventricular biopsy of hypothalamic mass. Pathology was consistent with LCH with immunohistochemistry staining for CD1a, Langerin and BRAFV600E, with occasional cells staining for CD68, CD163 and S100. Bone marrow biopsy was normal. A NM PET scan revealed a hypermetabolic hypothalamic mass compatible with LCH without evidence of involvement of other sites including the skeletal system. Given histopathologically confirmed BRAF-mutated LCH, treatment with Vemurafenib was initiated. Behavioral changes gradually improved, and repeat MRI brain three months after treatment revealed decrease in size of hypothalamic mass.

Conclusion: Isolated hypothalamic LCH is exceedingly rare. No clear guidelines exist for treatment of LCH in adults. BRAFV600E mutations are found in more than fifty percent of LCH cases and are associated with worse outcomes. This case demonstrates the successful use of targeted BRAF inhibitor therapy in an adult patient with BRAF mutated hypothalamic LCH.
SUN-254 Angiotensin II Stimulates Microglia Cell Inflammatory Responses
Authors: Velez Jean Paul Moliere , Inostroza-Nieves Dra Yaritza , Romero Jose R , Arenas Claudia , Capo Diego
Published: May 2020

Angiotensin II (AngII) is the principal effector molecule of the renin-angiotensin system (RAS). It’s effects on the cardiovascular and renal system are well-documented. AngII acts mainly via interaction with the AngII type-1 receptor (AT1R). Disordered levels of AngII lead to hypertension and cardiovascular disease. Increasing evidence suggests that AngII may also play a role in the pathophysiology of neurodegenerative diseases through unclear mechanisms. We investigated AngII, AT1R and AT2R levels in a mouse model of neurodegenerative disease, the experimentally induced autoimmune encephalomyelitis (EAE) mouse. In EAE mice, AngII and AT1R gene expression in brain tissue were significantly increased when compared to control mice (3.2 folds ±1.9, p<0.05, n=5; and 2.6 folds ±1.1, p<0.01, n=5 respectively). In addition, iNOS mRNA expression by qRT-PCR was likewise upregulated in EAE mice compared to control (3.4 ± 1.4 folds, p<0.01, n=5). We then studied the effects of AngII in human microglial cells (HMC3) -resident innate immune cells of the central nervous system (CNS). In HMC3 cells, treatment with AngII up-regulated the expression IL-6 (3.9 folds ± 1.2, p<0.01, n=4) and increased IL-6 concentration by 83% (p<0.05, n=4) by ELISA; effects that were blocked by the AT1R antagonist, Losartan. Also, AngII induced TNF-α production, increasing its concentration by 90% (p<0.05, n=4), an increase that was blocked by Losartan. We also quantified Nitric Oxide (NO) production by using Griess Reagent and reactive oxygen species (ROS) production by the MUSE Oxidative Stress assay. In these cells, NO and ROS production were significantly increased by AngII (p<0.05, n=4) and treatment with Losartan reduced their production (p<0.05, n=4). In addition, AngII treatment induced iNOS overexpression (2.5 folds ±0.8, p<0.05, n=4); results that are consistent with increases in the EAE mice. These data suggest that AngII can activate microglia cell inflammatory responses and as such may contribute to the pathophysiology of CNS inflammation and neurodegenerative diseases.
MON-709 Single-Cell RNA-Sequencing Deciphers POMC Neuron Destiny
Authors: Yu Hui , Jones Graham , Thompson Zoe , Rubinstein Marcelo , Low Malcolm James
Published: May 2020

The hypothalamus is one of the critical brain nodes regulating body weight and energy homeostasis. Within this node, Pomc neurons sense nutrient and hormonal signals to release melanocortin peptides that induce satiety, whereas AgRP/NPY neurons exert opposite effects by releasing AGRP that promotes feeding. Immature neurons in the hypothalamic ventricular zone start to express Pomc at E10.5, reach a maximum number at E14.5 and then decrease to stabilize at E18.5. However, it remains elusive how Pomc expressing precursors adopt their final cell fates. Therefore, the goal of this study was to decipher the temporal sequence of transcription factor (TF) expression leading to the terminal differentiation of POMC neurons. Red fluorescent cells collected from dissociated hypothalami of Pomc-tDimer-dsRed mice at six critical developmental time points - E11.5, E13.5, E15.5, E17.5, P5 and P12- were FACS sorted for the 10X genomics scRNA-seq pipeline. Unsupervised cell clustering identified 11 distinct clusters based on their transcriptional profiles. Eight of the clusters were highly-enriched for neuronal signature genes and were further characterized based on their transcript levels for Pomc (high, medium or low) and other distinct feature genes. Cells in the Pomchigh cluster expressed genes identified previously to modulate Pomc expression, including Isl1, Nkx2-1, and Tbx3, together with several novel candidate TFs. Unexpectedly, Nr5a1, the ventromedial hypothalamic nucleus marker gene encoding SF1, was highly expressed in the Pomchigh cluster at early stages. One of the Pomclow clusters highly expressed Otp, Agrp, Npy, Sst and Calcr while a second was highly enriched with Tac2, Kiss1, Pdyn, Prlr, Ar and Esr1 transcripts. All the clusters showed direct correlations of embryonic stage with the expression of progressively more mature markers of differentiation, thereby extending previous reports of these clusters based on single time points. Moreover, our results uncovered five novel Pomc neuron clusters with unique patterns of TF gene expression. For comparison of these data to the adult hypothalamus, we performed a TRAP-Seq study using PomcCreERT,Rosa26eGFP-L10a mice. Prdm12 and Tbx3 were among the most highly differentially expressed TFs in the POMC neuron affinity purified translatome. Similarly, Cited1, Npy2r, and Asb4 were highly expressed in both the Pomchigh cluster and the TRAP-Seq derived POMC translatome. This comprehensive molecular characterization of POMC cells during development sheds new light on the molecular diversification of early POMC neuron precursors and provides a valuable resource for elucidating the regulatory mechanisms defining POMC neuron subgroups in the hypothalamus.
MON-535 Deep-Machine Learning for Objective Quantification of Nerves in Immunohistochemistry Specimens of Thyroid Cancer
Authors: Astono Indriani , Rowe Christopher W , Welsh James , Jobling Phillip
Published: May 2020

Introduction: Nerves in the cancer microenvironment have prognostic significance, and nerve-cancer crosstalk may contribute to tumour progression, but the role of nerves in thyroid cancer is not known (1). Reproducible techniques to quantify innervation are lacking, with reliance on manual counting or basic single-parameter digital quantification.

Aims: To determine if a deep machine learning algorithm could objectively quantify nerves in a digital histological dataset of thyroid cancers immunostained for the specific pan-neuronal marker PGP9.5.

Methods: A training dataset of 30 digitised papillary thyroid cancer immunohistochemistry slides were manually screened for PGP9.5 positive nerves, annotated using QuPath (2). 1500 true positive nerves were identified. This dataset was used to train the deep-learning algorithm. First, a colour filter identified pixels positive for PGP9.5 (Model 1). Then, a manually tuned colour filter and clustering method identified Regions of Interest (ROIs): clusters of PGP9.5 positive pixels that may represent nerves (Model 2). These ROIs were classified by the deep learning model (Model 3), based on a Convolutional Neural Network with approximately 2.7 million trainable parameters. The full model was run on a testing dataset of thyroid cancer slides (n=5), containing 7-35 manually identified nerves per slide. Model predictions were validated by human assessment of a random subset of 100 ROIs. The code was written in Python and the model was developed in Keras.

Results: Model 2 (colour filter + clustering only) identified median 2247 ROIs per slide (range 349-4748), which included 94% of the manually identified nerves. However, most Model 2 ROIs were false positives (FP) (median 85% FP, range 68-95%), indicating that Model 2 was sensitive but poorly specific for nerve identification. Model 3 (deep learning) identified fewer ROIs per slide (median 1068, range 150-3091), but still correctly identified 94% of manually annotated nerves. Of the additionally detected ROIs in Model 3, median FP rate was 35%. However, in slides where higher non-specific immunostaining was present, then the number of FP ROIs was >90%.

Conclusion: Simple image analysis based on colour filtration/cluster analysis does not accurately identify immunohistochemically labelled nerves in thyroid cancers. Addition of deep-learning improves sensitivity with acceptable specificity, and significantly increases the number of true positive nerves detected compared to manual counting. However, the current deep learning model lacks specificity in the setting of non-specific immunostaining, which is a basis for improving further iterations of this model to facilitate study of the significance of innervation of thyroid and other cancers.

References: (1) Faulkner et al. Cancer Discovery (2019) doi: 10.1158/2159-8290.CD-18-1398. (2) Bankhead P et al. Sci Rep 2017;7(1):16878.
SAT-588 Role of Adipose Tissue in Reproduction, Mammary Gland Development, Function and Cancer
Authors: Brenot Audrey , Hutson Irina , Harris Charles Andrew
Published: May 2020

To investigate the role of adipose tissue in the function of the mammary gland (MG) and reproductive system, we have examined lipodystrophic (LD) mice. LD mice of both sexes are sterile, but fertility was restored in both sexes with leptin injections. In addition, leptin was only needed for initial stages of pregnancy and not for parturition. A transplant of mouse embryonic fibroblasts (MEFs) led to the formation of an ectopic fat pad which also rescued the fertility in both sexes. However, pups born to rescued LD mothers died shortly after birth. We therefore examined the mammary glands of these mothers. MGs from LD mice were rudimentary and lacked terminal end buds. Leptin-injected and MEF rescued LD mice were able to become pregnant, showed normal pregnancy-associated glandular proliferation despite a smaller glandular area, were able to produce a small amount of milk that had grossly normal content of milk proteins and neutral lipids, but could not sustain pups to weaning. In order to separate the individual requirements for 1) adipokines such as leptin, 2) estradiol, and 3) epithelial-adipocyte interactions, we performed a series of experiments with both LD and ob (leptin-deficient) mice that received either estradiol or preadipocyte transplant. The resulting fat pad did not rescue the defect in MG development in LD mice. The defect also was not rescued with estradiol pellets. Ob/ob mice, like LD mice, lack leptin and estradiol, but retain adipose tissue. Ob mice have defective MG development. However, in striking contrast to LD mice, reconstitution of a WT fat pad in ob mice rescued the defect in MG development. Estradiol treatment did not rescue MG development in ob mice. Therefore direct interaction between mammary gland epithelia and adipocytes is a requirement for full invasion and expansion of the gland during puberty, but is not required for glandular proliferation during pregnancy and milk production.

Given that excess adipose tissue is a risk factor for breast cancer we wanted to determine if breast cancer was affected by the absence of adipose tissue. LD mice were bred to MMTV-PyMT mice that develop spontaneous breast cancer. Remarkably, LD PyMT+ mice had accelerated growth of primary tumors compared to WT PyMT+ mice. Using our MEF transplant model future studies will be directed to understanding whether the accelerated breast cancer growth is due to loss of adipokines or altered epithelial-stromal interactions.
SAT-463 Thyrotoxicosis from Nivolumab in a Patient with Preexisting Graves’ Disease
Authors: Polavarapu Preethi , Akkireddy Padmaja
Published: May 2020

Introduction

Thyroid dysfunction is one of the common immune-related adverse events associated with immune checkpoint inhibitors like Nivolumab. Thyroiditis or primary hypothyroidism is the most commonly reported presentation. Graves’ disease is less frequently reported. We report a case of preexisting Graves’ disease patient, on antithyroid meds who developed thyrotoxicosis followed by hypothyroidism after receiving Nivolumab therapy.

Case

66 y/o female patient with newly diagnosed metastatic melanoma presented to us for evaluation of abnormal thyroid test after her second cycle of Nivolumab. She has a long-standing history of Graves’ disease and has been on methimazole since her diagnosis. Her baseline thyroid labs before the start of Nivolumab were within normal limits (on methimazole 2.5 mg daily). She presented with weight loss, palpitations, and tremors four weeks after the start of Nivolumab. On exam, she was tachycardic with tremors noted to outstretched hands and had diffusely enlarged thyroid. Repeat lab work done before her second cycle revealed suppressed TSH 0.02 (0.4-4.5 uIU/ml) with elevated free T4 and T3. Her TSI titers were elevated. Methimazole dose was increased to 10 mg daily, and follow up labs done in a month revealed TSH of 89 uIU/ml, Free T4 0.16 (0.76-1.8 ng/dl). Methimazole was completely stopped at this time. She continued to have elevated TSH despite being off of methimazole for more than a month, concerning for the development of hypothyroidism. She was started on levothyroxine, after which labs returned to normal. The patient continued on immunotherapy during this period.

Discussion

Immune checkpoint inhibitors have been increasingly used for cancer therapy. Endocrinopathies are the most common immune-related adverse events associated with the use of these agents, with thyroid dysfunction being more common. Our patient had well-controlled Graves’ disease and was on a stable dose of methimazole for years. She developed autoimmune thyroiditis four weeks after receiving immunotherapy and subsequently developed hypothyroidism. The literature search did not reveal cases of autoimmune thyroiditis in a patient with preexisting Graves’ disease. One study reported that the timeline for developing the thyrotoxic phase is five weeks, which is followed by the rapid development of either euthyroid or hypothyroid phase. Management during the thyrotoxic phase is usually beta-blockers. Current guidelines recommend checking thyroid function test before initiation of therapy and every two weeks after the diagnosis of thyrotoxicosis until they become euthyroid or hypothyroid.

Our case illustrates that patients with preexisting Graves’ disease can develop thyroiditis after receiving immune checkpoint inhibitors, and hence, frequent monitoring with thyroid function tests is needed.
SAT-632 Involvement of NF-κB-p65 in BAG3 Regulation After Stress Stimuli
Authors: Dhanabalan Karthik , Singh Madhu V , Wong Thomas , Dokun Ayotunde O
Published: May 2020

We previously identified the limb salvage QTL1 (LSQ-1) on mouse chromosome 7 as a locus that offered protection against ischemic injury following induction of hind limb ischemia (HLI) a model of experimental peripheral arterial disease (PAD) in mice. To better understand the role of the LSQ-1 locus in post ischemic adaptation we characterized several genes within this locus and identified a number of genes that were important in tissue adaptation to ischemia, including BCL2-associated athanogene 3 (BAG3). BAG3 is an anti-apoptotic protein that plays an important role in cell survival through the regulation of autophagy. BAG3 expression is induced in the gastrocnemius muscles of mice after hind limb ischemia but how ischemia regulates BAG3 expression is poorly understood. Additionally, the activation of NF-κB transcription factor is essential for cell survival after stress stimuli. We hypothesized that BAG3 upregulation following stress stimuli is regulated by NF-κB. We determined whether NF-κB is involved in BAG3-mediated survival of primary human skeletal muscle cells (HSMC) during ischemia and diabetic conditions. Within 6 hours of treatment, ischemia induced BAG3 mRNA (no ischemia vs ischemia: 1.0 ±0.09 vs 1.41±0.02; p<0.01) and protein expression (BAG3/total protein, no ischemia vs ischemia 1.0±0.01 vs 1.38±0.06; p<0.01). Knockdown of BAG3 expression by shRNA induced early cell damage in HMSC under ischemic conditions as measured by HMGB1 expression (HMGB1/total protein; control plasmid vs shRNA, 1.0±0.09 vs 1.71±0.04; p<0.01). Knockdown of p65 subunit of the NF-κB by shRNA significantly diminished BAG3 mRNA expression after ischemia (control plasmid vs shRNA: 2.11±0.18 vs 1.48±0.05; p<0.05). Moreover, treatment of HSMC with 750 uM palmitic acid (PA) and 100nM insulin for 3 days to mimic diabetic conditions significantly increased the expression of BAG3 mRNA (control vs PAL+Ins, 1.0±0.14 vs 2.27±0.08; p<0.01) and protein (BAG3/total protein, control vs PAL+Ins, 1.0±0.03 vs 1.39±0.11, p<0.01). Knocking down p65 attenuated these increase in BAG3 mRNA (PAL+Ins vs shRNA+PAL+Ins, 2.27±0.08 vs 1.56±0.02 p<0.01) and protein (BAG3/total protein; PAL+Ins vs shRNA+PAL+Ins, 1.39±0.11 vs 0.99±0.1; p<0.05) Thus, 1) BAG3 expression is important in cell survival under ischemic conditions, and 2) NF-kB plays a key role in upregulating the expression of BAG3 under diabetic and ischemic conditions.
MON-687 Diabetic Muscle Infarction (DMI) a Rare Under-Recognised Complication of Diabetes Mellitus (DM): A Series of Three Cases
Authors: Dhanasekaran Maheswaran , Kishore Preeti , Schubart Ulrich K
Published: May 2020

Background: Diabetic muscle infarction (DMI) also known as diabetic myonecrosis is an acute, rare, microangiopathic complication of long-standing poorly controlled Diabetes Mellitus (DM). DMI presents as severe pain and swelling of the affected muscle group, usually of the lower extremities. It generally occurs in patients with established vasculopathy from uncontrolled diabetes including retinopathy and nephropathy. However, a clear association of DMI to long term mortality has not yet been defined. Proposed pathophysiologic mechanisms for DMI are microvascular endothelial damage complicated by thromboembolic events triggering an inflammatory cascade, leading to local tissue ischemia and eventual infarction. Alterations in the coagulation-fibrinolysis system and vasculitis have also been invoked. About 50% of the cases have DMI recurrence in the setting of uncontrolled DM.

Clinical Case: We report 3 cases of DMI diagnosed in patients with long-standing poorly controlled DM with at least two established micro-vascular complications. The lower extremity muscle group was affected, especially the thigh muscles and paraspinal muscle in one case. Biochemical parameters were significant for normal white blood cell counts, elevated erythrocyte sedimentation rate (112, 105, 145 mm/hr respectively; n 0–15 mm/hr) and C-reactive protein (CRP) (54.3, 260, 162 mg/L respectively; n 0–5.0 mg/L) and elevated creatine kinase in two cases (539 and 379 U/L; n 5–150 U/L). Infectious work-up including blood cultures were negative. Lower extremity doppler was negative in all three cases. Diagnosis was established with the help of MRI in two cases showing diffuse hyperintensities of the muscle groups involved and muscle biopsy in the third showing neutrophilic and eosinophilic inflammation and areas of necrosis, fibrosis and hemorrhage. Treatment involved adequate pain management and anti-platelet therapy along with tight glycemic control. No recurrence thus far was noticed in all three patients.

Conclusion: DMI should be considered in the differential diagnosis of patients with the aforementioned risk factors who did not show a response to antibiotics, as administered for presumed cellulitis. Though self-limiting, studies have shown a long term temporal correlation with increased all-cause mortality in patients with DMI. Hence DMI is considered as another cardiovascular risk equivalent. Further studies are needed to explore strategies aimed at preventing DMI and its recurrence.
MON-617 Improving Care Transitions: Optimizing Diabetes Medication Reconciliation
Authors: Oraibi Omar , Holmes Kimberly , Pichardo-Lowden Ariana
Published: May 2020

Introduction

Medication reconciliation (MR) is essential in caring for hospitalized patients with diabetes (DM). Inaccuracies prevail, affecting transitions of care. Factors contributing to errors are driven by providers, patients, and systems of practice and increase in transitions out of hospital. A study showed that MR errors occurred in about 38 % of admissions. Common discrepancies among DM subjects were related to DM and cardiovascular drugs. An intervention aiming to reduce MR discrepancies at discharge achieved 70% less errors due to communication between inpatient providers, primary care and patients within 24 hours. Systems-based interventions and multidisciplinary approaches show promise to improve processes. However, a comprehensive assessment of the elements of practice to target and how interventions may be more effective is lacking. Our purpose was to examine aspects of practice among personnel responsible for the MR steps, and within the hospital workflow in order to identify gaps in the process. We intend to recognize factors to be targeted to optimize MR for DM, and to provide a multipronged approach to inform changes in hospital processes.

Methods:

We used quantitative and qualitative methods to investigate errors in the MR process as part of a hospital quality improvement program. We randomly included patients 18 years or older with type 1 or 2 DM evaluated by the endocrine team for 6 months. Chart reviews were conducted to assess type and frequency errors. Interviews of nurses, pharmacists, clinicians, and DM educators were sought to understand unique situations and the roles of health providers in the MR process.

Results

Twenty-two subjects were identified with one or more of the following gaps in their MR pertaining to DM medications: a) missing, b) redundancy, and c) dosing error. Scenarios included ≥2 discrepancies (4 of 22); ≥1 medication inappropriately changed from home regimen (18 of 22); redundantly adding a medication (4 of 22); wrong dose of medication (1 of 22); incomplete prescription for DM supplies (8 of 22).

Conclusion:

We identified deficits and their attribution to professionals and categorized errors in hospital workflows. Observations, providers’ insights and literature review enabled an assessment of MR failures. We developed a conceptual model where types of error, professionals’ roles, and solutions intersect Interface of prioritizing actions, hospital resources, use of checklists, interdisciplinary collaborations, and staff education is essential to advance adequate MR in the system of practice. Our future steps include a Plan-Do-Study-Act cycle to advance care.
MON-586 Gut Hormones Response to 24-H High Carbohydrate Overfeeding Is a Determinant of Metabolic Adaptation to Carbohydrate Intake in Healthy Individuals
Authors: Vinales Karyne Lima , Holltein Tim , Begaye Brittany , Walter Mary , Krakoff Jonathan , Piaggi Paolo
Published: May 2020

Background: We previously demonstrated that short-term (24h) changes in carbohydrate (CARBOX) or fat oxidation rates in response to overfeeding diets with different macronutrient content are highly correlated within an individual, suggesting the existence of human metabolic phenotypes (carbohydrate vs. fat oxidizers). Gut hormones have a role in feeding and substrate oxidation, thus we investigated if the changes in gut hormones concentration during overfeeding diets or fasting explain the degree of metabolic flexibility in healthy humans.Methods: While residing in our clinical research unit, 67 healthy, weight-stable volunteers (37±10y, BMI: 26±4 kg/m2, body fat: 28±10%; mean±SD, 54 men) with normal glucose regulation had 24-h EE measurements in a whole-room indirect calorimeter during energy balance (EB, diet: 50% carbohydrate, 20% protein), three overfeeding diets, and fasting in a crossover design. The overfeeding diets (200% of weight-maintaining energy requirements) included diets with 20%-protein [50%-carbohydrate (SOF), 75%-carbohydrate (CNP), and 60%-fat (FNP)]. Metabolic flexibility was determined by the difference between respiratory quotient (RQ) during overfeeding/fasting from EB conditions. Plasma GLP-1, PYY, PP, and total ghrelin concentrations were measured by ELISA after an overnight fast the morning of and after each diet. Results: PYY increased after all overfeeding diets (3.4±13.1, 7.0±16.2, and 7.6±14.4 pg/mL; all p<0.05, SOF, CNP and FNP respectively) and decreased with fasting (-11.6±14.2 pg/mL; p<0.001). GLP-1 increased after fasting (2.7±5.8 pg/mL; p<0.001) and FNP (1.3±4.5 pg/mL; p=0.02) and decreased with CNP (-0.9±6.3 pg/mL; p=0.04). PP only increased after fasting (92.8±133.4 pg/mL; p<0.001), while ghrelin decreased with SOF (-31.3±108 pg/mL; p=0.02) and CNP (-43.1±120 pg/dL; p=0.005) but not with FNP (p=0.51). After adjustment for body composition and other known EE determinants, no hormonal changes were associated with the change in 24-h EE in any diet (all p>0.05); however, during CNP greater decreases in GLP1, PYY, and Ghrelin were associated with less increase in 24-h RQ (all r>0.25; all p<0.05) while greater decrease in PP was associated with larger increase in 24-h RQ (r=-0.31, p=0.01). Specifically, greater increase in CARBOX during CNP was positively associated with the changes in GLP-1 (r=0.30; p=0.02) and Ghrelin (r=0.32, p=0.01). In a linear model, only the change in GLP-1, PP, and Ghrelin concentrations during CNP were independent predictors of the change in RQ [β=0.003; -0.0001; and 0.000006 per 1 pg/mL increase each, p=0.008; 0.02 and 0.02 respectively], after accounting for age and sex. Conclusion: In a carbohydrate rich environment, individuals with normal glucose regulation who maintain GLP-1 and ghrelin levels are better adapted to metabolize this type of diet.
SUN-345 Use of Anti-FGF23 Monoclonal Antibody in the Treatment of Children and Adolescents with X-Linked Hypophosphatemic Rickets
Authors: Cassinelli Hamilton Raul , Brenzoni Luciana , Alconcher Laura , Forclaz Veronica , D′Amato Silvia , Rozenfeld Paula , Bergada Ignacio
Published: May 2020

Background: X-linked hypophosphataemia is the most common heritable form of rickets in children, disorder caused by mutations in PHEX, leading to elevated secretion of FGF23, renal phosphate wasting with consequent hypophosphataemia, diminish synthesis of 1,25(OH)2 vitamin D, rickets/osteomalacia, and disproportionate short stature. Conventional treatment with oral phosphate supplementation and active vitamin D heals rickets, prevents progressive growth failure, but in a substantial proportion of patients treatment is unsuccessful and/or associated with adverse effects. Since 2018, burosumab, a human monoclonal antibody against FGF23, was approved for the treatment of X-linked hypophosphataemia.Aim: We report a pilot experience on the efficacy and safety of treatment with burosumab in children and adolescents with X-linked hypophosphataemia (XLH). Methods and patients: Eight XLH patients (5 males) (5 pre pubertal and 3 Tanner IV) with an age range from 2.9 to 16.2 years, were recruited, 6/8 had family history of XLH, the remaining two were confirmed with molecular study. All discontinue conventional therapy at least 7 days before treatment with Burosumab which was administered every 2 weeks SC for 6 months, at a starting dose of 0.8 mg/kg/dose. Growth velocity, Thacher Rickets Severity Score, fasting serum calcium (mg/dl), phosphorus (P)(mg/dl), alkaline phosphatase (ALP)(IU/L), PTH (pg/dl), 25OH Vitamin D (ng/ml) and tubular phosphate reabsorption (TPR) (X±SD) were evaluated at basal, 3, and 6 months of treatment. Results: All patients had normal 25OH2 Vitamin D: 35.3±8.6 ng/ml at the start of therapy and had significantly improvement of serum P: basal 2.2±0.51, 3 months: 3.24±0.43 and at 6 months 3.01±0.38 mg/dl (p<0.005). The mean serum ALP level decreased from 686.9±410.8 to 535.8±302.4 and 402.5±106.7 IU/L (p<0.05) respectively. TPR normalized during treatment: 67.3±9, 86±3.1, and 86.9±6.1 %(p<0.001). The severity of rickets, as well, showed a significant improvement: 4.0±2.0, 2.3±1.2, and 1.0±0.8 (p<0.005), respectively. The non-pubertal children increased their growth velocity from 3.7±1.2 cm/yr to 7.0±1.4, and 7.9±2.0 cm/yr (p<0.05) respectively. Serum calcium and PTH levels did not show any significantly variation. Mild adverse events such as local reactions and headaches were observed. Conclusions: 1) Treatment with burosumab restores phosphate metabolism, 2) Growth and the Thacher Rickets Severity Score improved during treatment, 3) all patients showed a good safety profile with only minor adverse events. This is the first report of children with XLH treated with burosumab in Latin-America.
SAT-145 Cholesterol Uptake as a Critical Vulnerability in Triple Negative Breast Cancer
Authors: O’Neill Kathleen
Published: May 2020

Triple Negative Breast Cancer (TNBC) is an aggressive subtype of cancer with poor prognosis due to high metastatic potential and lack of targeted therapies. Normal epithelial cells express the microRNA-200c (miR-200c), a potent suppressor of epithelial-to-mesenchymal transition (EMT). However, miR-200c is silenced or lost in TNBC, allowing a de-differentiated, non-epithelial phenotype and aberrant expression of genes conferring invasive and chemoresistant characteristics. Recent literature has demonstrated that EMT promotes altered tumor cell metabolism, creating novel vulnerabilities that can be exploited therapeutically. In addition to driving global metabolic changes, miR-200c-induced reversal of EMT alters key cholesterol metabolism genes that support the uptake of dietary cholesterol from the bloodstream. Intracellular cholesterol homeostasis is critical for cell survival and is carefully regulated, but how these homeostatic mechanisms adapt during tumor progression is poorly understood. Based on preliminary data, I hypothesize that TNBCs depend on exogenous cholesterol uptake and availability to maintain cell viability and an invasive phenotype. This work aims to identify novel cholesterol-related targets in breast cancer and delineate mechanisms regulating cholesterol homeostasis in normal and cancer physiology.Restoration of miR-200c in TNBC leads to alteration of the cholesterol uptake components low- and very-low-density-lipoprotein receptors LDLR and VLDLR, through direct and indirect mechanisms previously unexplored in cancer. miR-200c further inhibits Niemann-Pick Type C (NPC1), a lysosomal protein necessary for utilization of exogenous cholesterol. Interestingly, expression of NPC1 in TNBC correlates with a unique inability of cells to proliferate in the absence of exogenous LDL supply, suggesting defects in de novo cholesterol biosynthesis. Further, NPC1 inhibition leads to cell death in TNBC but not more epithelial-like breast cancers. Whether this cell death is due to disruption in critical cholesterol supply or due to defective lysosome dysfunction is currently being investigated. Overall, this work suggests a role of NPC1 in cancer cell metastasis that has not been previously explored, and identifies cholesterol uptake as a targetable dependency in TNBC.
SAT-079 Is There an Association Between the Detection Method for Pediatric Thyroid Nodules and the Risk of Malignancy?
Authors: Eng Liane , Chen Jarreau Spencer Sim , Lam Leslie S
Published: May 2020

Background

Thyroid nodules are less common in children compared to adults, but have a higher likelihood of malignancy. There are few studies, particularly in the pediatric population, examining the association between how and by whom the nodule is detected and the risk of malignancy. Several adult studies have suggested a high rate of malignancy in incidentally discovered thyroid nodules (1,2). However, this was not similarly seen in pediatric thyroid nodules according to one study (3). As fine needle aspiration (FNA) in pediatric patients may be more labor intensive and diagnostic excision is the recommendation for nodules with indeterminate or potentially malignant cytology, if the detection method can be a predictive measure of malignancy, it may enhance the evaluation of pediatric thyroid nodules.

Objective

The aim of this study is to determine if there is an association between how and by whom a thyroid nodule is detected and the risk of malignancy in the pediatric population.

Study Design and Methodology

We retrospectively reviewed the medical records of pediatric patients (≤21 years of age) who had a thyroid nodule with definitive cytologic or pathologic diagnosis from January 2010 to June 2019. Patients were categorized into 3 groups based on how and by whom the nodule was detected: (1) patient or parent, (2) provider, or (3) imaging obtained for non-thyroid indications (incidental). Characteristics that were evaluated included rate of malignancy, size of the nodule, location of the nodule, and size of the cancer (if present).

Results

A total of 78 patients with concerning thyroid nodules were analyzed. Within the study, the cancer rate was 27% (21/78), which is comparable to the reported malignancy rate of pediatric thyroid nodules in the literature (22-26%) (4), suggesting that our sample population may be representative of the general pediatric thyroid nodule population. In our study, though the absolute numbers were small, there was a higher rate of malignancy in the incidental group (3/5, 60%) compared to the patient/parent (9/34, 26%) and provider (9/39, 23%) groups. The average size of the thyroid nodule was similar in all 3 groups. The strength of this study was the inclusion of only patients with definitive diagnosis of the thyroid nodule and the possibility of the findings being applicable to the general pediatric population.

Conclusions

In our sample study, incidentally discovered pediatric thyroid nodules had a higher rate of malignancy as compared to those discovered by patients/parents or providers.

References

1.

Kang HW, et al. Thyroid 2004; 14(1):29-33.

2.

Liebeskind A, et al. J Ultrasound Med 2005; 24(5):629-634.

3.

Gupta A, et al. J Pediatr 2014; 164(3):658-660.

4.

Francis GL, et al. Thyroid 2015; 25(7):716-758.
SAT-141 Glycoprotein NMB (GPNMB) Is Pro-Tumorigenic in TSC2-Null Cancer Cells and Is a Potential Drug Target and Biomarker for Lymphangioleiomyomatosis (LAM)
Authors: Gibbons Erin , Taya Manisha , Seger Christina , Hammes Stephen R
Published: May 2020

Lymphangioleiomyomatosis (LAM) is an estrogen-sensitive lung disease found almost exclusively in women that is characterized by hyperproliferation of smooth muscle cells forming small tumors, or LAM lesions throughout the lungs of patients. Growth of these tumors leads to progressive loss of pulmonary function, and sometimes subsequent lung transplantation. LAM tumor cells contain mutations in either the TSC1 or TSC2 genes, leading to activation of the mTORC1 pathway. In fact, mTOR inhibitors such as sirolimus are commonly used to treat LAM; however, these drugs are not always effective and have significant side effects, suggesting the need for new therapeutic targets. Interestingly, another important feature of LAM cells is that they express melanocytic markers that are normally found in melanocytes or melanoma cells. From RNASeq analysis of a mouse model for LAM that we designed, we discovered significant upregulation of the melanocytic marker Glycoprotein Non-Metastatic Melanoma Protein B (GPNMB), a type I transmembrane protein. GPNMB was not only highly expressed in our mouse model (a uterine specific TSC2-null mouse), it was also expressed in TSC2-null cell lines, and human LAM patient lung samples. In our hands, knocking down GPNMB expression by siRNA directed against GPNMB mRNA decreased migration and proliferation in TSC2-null cells. Additionally, we found that GPNMB’s large ectodomain is shed by TSC2-null cells and can be detected in the blood of human patients with LAM. Finally, MMP 2 and 9 can be secreted as a result of ectodomain shedding and its interaction with integrins. Accordingly, we did indeed see a decrease in MMP 2/9 expression in TSC2-null cells with reduced GPNMB expression from treatment with siRNA directed against GPNMB mRNA. Overall, our results demonstrate the potential importance of GPNMB in LAM tumor progression, and suggest that GPNMB may be a possible LAM biomarker and target for its treatment.
SAT-649 Comparison of the Accuracy and Concordance of 3 CGM Devices vs SMBG During Aerobic Exercise
Authors: Henske Joseph A , Thostenson Jeff D
Published: May 2020

Introduction: Real-time continuous glucose monitoring (rt-CGM) and flash glucose monitoring (FGM) devices have become important tools for managing type 1 diabetes. These devices are approved for management decisions in steady-state conditions, however there is a decline in accuracy during aerobic exercise with respect to MARD and lag time.1 It is possible that newer technologies may be superior to previous devices.

Question: With the newest rtCGM, FGM, and long-term CGM devices, do we continue to see an increase in MARD during continuous aerobic exercise? Is there a difference between glucose readings of the 3 devices when worn simultaneously during exercise?

Design: A single subject with T1DM, experienced in glucose management during exercise, wore 3 devices simultaneously - the DEXCOM G6 (San Diego, CA; rt-CGM1, worn on the abdomen), the Eversense (Germantown, DM; long-term CGM or rt-CGM2, implanted in the left arm), and the Abbott Freestyle Libre 14-day (Chicago, IL; FGM, worn on the right arm). The rt-CGM2 was calibrated using a blood glucose meter (Ascensia Contour Next) which was also used for comparator SMBG. Glucose was recorded 10 minutes before and after exercise and every 10 minutes during a 60 minute run at moderate intensity. 6 exercise sessions were averaged for data analysis. Subject wore an insulin pump and reduced the basal rate by 50% 90 minutes prior to exercise and resumed the basal immediately post-exercise. Carbohydrates were not used within 3 hours prior to exercise but could be consumed during exercise if needed to avoid hypoglycemia.

Results: Glucose value during 60 minutes of exercise dropped from mean of 167 to 114 mg/dL with SMBG, 174 to 115 mg/dL with rt-CGM, 175 to 115 with rt-CGM2, and 150 to 106 mg/dL with FGM. Average measured glucose was 140.0, 145.8, 145.6, and 129.3 mg/dL for SMBG, rt-CGM1, rt-CGM2, and FGM respectively. P-value <0.05 for FGM. MARD (calculated compared to SMBG) for 10 minutes pre-exercise, during exercise, and post-exercise for rt-CGM1 was 5.1%, 11.7%, and 8.6% respectively. For rt-CGM2 MARD was 7.7%, 11.4%, and 10.0% respectively. For FGM, MARD was 12.7%, 5.3%, and 21.3% respectively. Overall MARD was 9.8% for rt-CGM1, 10% for rt-CGM2, and 8.0% for FGM.

Conclusions: Blood glucose values dropped with aerobic exercise with observed lag between CGM and SMBG. Rt-CGM1 and Rt-CGM2 showed increased MARD vs SMBG during exercise. Interestingly, lower MARD was seen for FGM during aerobic exercise likely due to bias towards lower glucose levels at baseline as reported by FGM. There was no significant difference seen during exercise between rt-CGM1 and rt-CGM2 despite the differing location of the sensors (transdermal vs subcutaneous) and method of glucose analysis (glucose oxidase vs fluorescence).

References: (1) Zaharieva et al. Diabetes Technol Ther 2019; 21: 313-321.
SAT-429 Systemic Safety Analysis of Mycophenolate in Graves’ Orbitopathy
Authors: Lee Alan C H , Diana Tanja , Frommer Lara , Kahaly George Jean
Published: May 2020

Context

The dual antiproliferative mechanism of mycophenolate appears to be beneficial in Graves’ orbitopathy (GO).

Methods

The safety data, which is of utmost importance in immunomodulation, from the two major randomized mycophenolate trials [“Chinese trial” (1) and “European Group on Graves’ Orbitopathy (EUGOGO) trial” (2)] and the original database of the EUGOGO trial were systematically analyzed. Treatment efficacy stratified by individual visual parameters of clinical disease activity and severity were also compared.

Results

A total of 129 adverse events (AE) involving 50 patients (29.4%) were noted among all mycophenolate-treated patients. Mycophenolate sodium plus intravenous glucocorticoid (MPS+GC) group of the EUGOGO trial recorded significantly more AE (55.4% versus 4.6% of patients affected) and serious adverse events (SAE) (12.5% versus 0%) than mycophenolate mofetil (MMF) group of the Chinese trial. The excess of AE may partly be contributed by GC use. None of those SAE was side effect (SE). Most SE in MPS+GC group (79%) were mild. Gastrointestinal disorders, infection and liver dysfunction affected 8.8%, 7.1% and 1.2% of all mycophenolate-treated patients (versus 5.4%, 5.4% and 1.2% of all patients on GC monotherapy, respectively). When compared to GC monotherapy, MPS+GC did not significantly increase the overall SE rate (25.3% versus 19.7%) nor did risks of infection or liver dysfunction, but it result in more mild gastrointestinal disorders (SE rate in EUGOGO trial 10.8% versus 4.9%). No cytopenia, serious infection, severe hepatotoxicity or treatment related mortality was reported among mycophenolate-treated patients. The much higher AE rates of mycophenolate trials in other autoimmune diseases or transplantations suggested that major mycophenolate toxicities were mostly dose- and duration-dependent. Regarding efficacy, mycophenolate achieved better overall response than GC monotherapy. Approximately 70% (versus 90% in MMF group) and 30% (versus 60–70% in MMF group) of patients in MPS+GC group achieved endpoints in most individual visual parameters of activity and severity, respectively. MPS+GC group of the EUGOGO trial performed better than MMF group in terms of improvement of pain and eye movement.

Conclusions

The risk-benefit ratio of 6-month courses of low dose mycophenolate treatment in active moderate-to-severe GO, either as monotherapy or as combination with GC, is highly favorable given its reassuring safety profile with low rate of mild to moderate SE and promising efficacy.

References:

(1) Ye et al., Clin Endocrinol (Oxf). 2017;86(2):247–55

(2) Kahaly et al. Lancet D&E. 2018;6(4):287–98
MON-321 AgRP and Food Cravings Decrease with Treatment of Cushing’s Disease
Authors: Haseltine Katherine N , Robins Hannah , Cohen Vanessa , Baratz Hannah , An Anjile , Kleiner Sandra , Geer Eliza Brevoort
Published: May 2020

Cushing’s disease (CD) is characterized by chronic exposure to excess glucocorticoids due to an ACTH-producing tumor. Obesity is a prominent feature of CD, although the mechanisms of weight gain have not been completely elucidated. In some patients, obesity persists despite appropriate medical or surgical treatment of CD and normalization of cortisol levels (1). Few studies have followed patients prospectively to understand the effect of CD remission and cortisol normalization on appetite and body weight. Previous studies have not shown a correlation between appetite or food cravings and circulating total peptide YY (PYY), ghrelin, or leptin concentrations, leading to interest in other hormones which may regulate appetite in CD (2). One of these is the neuropeptide Agouti-related protein (AgRP). AgRP is known to promote appetite and decrease energy expenditure by acting as a melanocortin antagonist at the level of the hypothalamus. Plasma AgRP may be elevated in patients with active CD and decreases with normalization of cortisol levels (3). We sought to determine if AgRP may play a role in regulating appetite or food cravings in CD. Plasma AgRP was measured before and prospectively after treatment in 19 patients with CD. Patients completed surveys on appetite and food cravings at these same time points. As expected, AgRP significantly decreased following treatment for CD, with mean AgRP before treatment 128.72 pg/mL (SD 55.41) and mean AgRP after treatment 75.23 pg/mL (SD 23.46). Using a paired t-test, the mean difference of 53.5 pg/mL was significant (p=0.0006). In addition, there were significant decreases in BMI, weight, and waist circumference with CD treatment. We found that plasma AgRP concentrations did not correlate with an 8-question visual analogue scale (VAS) used to assess hunger and satiety. However, treatment of CD significantly reduced Trait Food Craving Questionnaire scores in parallel with circulating AgRP levels using a one-way analysis of variance (p=0.004). Our data suggest that AgRP may play a role in food craving, rather than appetite, in patients with CD. Further research may clarify the relationship between AgRP and food cravings in CD patients before and after treatment. References:

1. Geer et al. Endocrinol Metab Clin North Am. 2014; 43: 75-102.

Geer et al. Pituitary. 2016; 19: 117-126.Page-Wilson et al, J Clin Endocrinol Metab. 2019; 104 (3): 961-969.