Plant circadian clock control of Medicago truncatula nodulation via regulation of nodule cysteine-rich peptides.

Legumes house nitrogen-fixing endosymbiotic rhizobia in specialized polyploid cells within root nodules, which undergo tightly regulated metabolic activity. By carrying out expression analysis of transcripts over time in Medicago truncatula nodules, we found that the circadian clock enables coordinated control of metabolic and regulatory processes linked to nitrogen fixation. This involves the circadian clock-associated transcription factor LATE ELONGATED HYPOCOTYL (LHY), with lhy mutants being affected in nodulation.

Spontaneous celiac artery dissection.

Background: Spontaneous celiac artery dissection is a rare visceral artery dissection that typically presents with acute abdominal or flank pain.

Case Report: We describe a case of a 54-year old previously healthy male who presented to the Emergency Department with subacute back pain and was found to have a spontaneous celiac artery dissection. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency medicine physicians frequently consider acute aortic dissection in patients presenting to the Emergency Department with acute chest, back, and/or upper abdominal pain.

What is the risk of diagnostic endoscopic retrograde cholangiopancreatography before cholecystectomy?

Many surgeons prefer to perform endoscopic retrograde cholangiopancreatography (ERCP) before cholecystectomy, specifically in patients at significant risk of having biliary pathology. However, a preoperative diagnostic ERCP, without the use of an endoscopic ultrasound or magnetic retrograde cholangiopancreatoscopy, remains controversial. This is the result of the risk of either performing an unnecessary procedure and/or the development of post-ERCP pancreatitis (PEP).