Structural Insights for β-Lactam Antibiotics

Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.

Primary Pancreatic Candidiasis Mimicking Pancreatic Cancer in an Immunocompetent Patient / 대한소화기학회지

Pancreatic candidiasis can develop in patients with acute pancreatitis, compromised immune responses, or iatrogenic intervention. This paper reports a case of pancreatic candidiasis presenting as a solid pancreatic mass in a patient without the risk factors. A previously healthy 37-year-old man visited the emergency department with left flank pain. Abdominal CT revealed a 5 cm, irregular heterogeneous enhancing mass accompanied by a left adrenal mass. Positron emission tomography-computed tomography and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) could not discriminate pancreatic cancer from infectious disease. A laparoscopic exploration was performed for an accurate diagnosis. After distal pancreatectomy with splenectomy and left adrenalectomy, pancreatic candidiasis and adrenal cortical adenoma were diagnosed based on the pathology findings. His condition improved after the treatment with fluconazole. This paper reports a case of primary pancreatic candidiasis mimicking pancreatic cancer in an immunocompetent patient with a review of the relevant literature.

Duodenal Loop Obstruction as an Unusual Cause of Acute Pancreatitis: A Case Series / 대한소화기학회지

Duodenal loop obstruction is an unusual cause of acute pancreatitis. Increased intraluminal pressure hinders pancreatic flow, causing dilatation of the pancreatic duct and inducing acute pancreatitis. We experienced three cases of acute pancreatitis that resulted from duodenal loop obstruction after (1) an esophagectomy with gastric pull-up procedure for esophageal cancer, (2) a gastrectomy with Billroth I reconstruction for gastric cancer, and (3) a gastrojejunostomy for abdominal trauma. An abdominal CT scan revealed a distended duodenal loop, dilated pancreatic duct, and inflamed pancreas with fluid collection. Acute pancreatitis with duodenal loop obstruction was diagnosed by abdominal pain, elevated serum amylase/lipase, and abdominal CT findings. Immediate decompression with a nasogastric tube was performed, and all patients showed improvement within one week after admission. Each patient was followed up for more than two years without recurrence. Our findings suggest the usefulness of nasogastric tube decompression as the first line of treatment for acute pancreatitis related to duodenal loop obstruction.