26 research outputs found
Efficient vapor‐phase selective hydrogenolysis of bio‐levulinic acid to γ‐valerolactone using cu supported on hydrotalcite catalysts
Abstract
In this work, Cu nanoparticles (Cu NPs, 2‐20 nm) supported on Hydrotalcite catalysts exhibit enhanced selectivity for γ‐valerolactone (GVL) during hydrogenolysis of levulinic acid (LA). At 260 °C, over 3 wt% Cu achieved 87.5% of LA conversion with a maximum GVL selectivity (95%). In contrast, LA hydrogenolysis over 3Cu/Hydrotalcite catalyst is highly active and stable toward the production of GVL due to balanced acido‐basicity and higher Cu dispersion with ultrasmall particle sizes, which are investigated through the temperature programmed desorption (TPD) of ammonia, N₂O titration, and transmission electron microscopy (TEM) analysis. Hydrotalcite in combination with inexpensive Cu catalyst is found to be an efficient and environmentally benign for LA hydrogenolysis
Supplementary Material for: Multifocal Insulinoma as the Unique Presenting Feature of MEN1 in an Adolescent
Introduction
Multiple Endocrine Neoplasia Type 1 (MEN1) is an autosomal dominant inherited disorder defined by the presence of two of the following endocrinopathies: primary hyperparathyroidism, anterior pituitary tumors, and duodenopancreatic neuroendocrine tumors (NETs). NETs, which can secrete hormones including insulin, gastrin, and glucagon, among others, are common in patients with MEN1 and are a major cause of morbidity and premature death. NETs are more common later in life, with very few cases described in children. Here, we describe a unique case of an adolescent with multifocal pancreatic NETs as the single presenting feature of MEN1.
Case Presentation
A 13-year-old healthy male presented with severe weakness, altered mental status, and syncope in the setting of a venous blood glucose (BG) of 36 mg/dL. Workup showed an elevated insulin level (14 mcIU/mL) when BG was 39 mg/dL with positive response to glucagon, concerning for hyperinsulinism. Diazoxide and chlorothiazide were started but not well tolerated secondary to emesis. Three suspected NETs were identified by MRI and 68-Ga DOTATATE PET-CT imaging, including the largest, a 2.1 cm mass in the pancreatic head. A fourth mass in the pancreatic tail was identified via intraoperative ultrasound. All lesions were successfully enucleated and excised, and glucose levels normalized off diazoxide by post-op day 2. While the primary lesion stained for insulin and somatostatin by immunofluorescence (IF), consistent with his clinical presentation, the additional tumors expressed glucagon, somatostatin, pancreatic polypeptide, and chromogranin A but were negative for insulin. Genetic testing confirmed a pathogenic heterozygous mutation in MEN1 (c.969C>A, p.Tyr323). He had no other signs of MEN-associated comorbidities on screening.
Discussion/Conclusion
This case demonstrates that young patients with MEN1 can present with multifocal NETs. These NETs may have polyhormonal expression patterns despite a clinical presentation consistent with one primary hormone. Our patient had clinical symptoms and laboratory evaluation consistent with an insulinoma but was found to have four NETs, each with different IF staining patterns. Advanced pre-operative and intraoperative imaging is important to identify and treat all present NETs. Moreover, serum hormone levels pre- and post-treatment could help evaluate whether NETs are actively secreting hormones into the bloodstream or simply expressing them within the pancreas. Finally, this case highlights the importance of genetic testing for MEN1 in all young patients with insulinomas