ABSTRACT
OBJECTIVE: We described a case of acute mesenteroaxial gastric volvulus in a male adolescent who presented to the pediatric emergency department (ED). CASE: A previously healthy male adolescent presented to the pediatric ED with gradual onset of epigastric pain, emesis, and a soft and nondistended abdomen. After evaluation, management, and resolution of the pain, the patient was discharged home with a primary care follow-up plan. Approximately 5 hours after discharge, the patient returned to the pediatric ED with worsening abdominal pain, the inability to tolerate oral intake, and a firm and distended abdomen. Subsequent evaluation identified an acute mesenteroaxial gastric volvulus. Pediatric surgeons performed an exploratory laparotomy, reduction of the gastric volvulus, and gastropexy, and the patient was discharged after a brief hospitalization. CONCLUSIONS: Acute gastric volvulus can present with symptoms similar to benign abdominal etiologies. Timely diagnosis and intervention are key to improved outcomes for patients.
Subject(s)
Stomach Volvulus/diagnosis , Acute Disease , Adolescent , Diagnosis, Differential , Emergency Service, Hospital , Humans , Intensive Care Units, Pediatric , Male , Stomach Volvulus/surgeryABSTRACT
Kidney podocytes and their foot processes maintain the ultrafiltration barrier and prevent urinary protein loss (proteinuria). Here we show that the GTPase dynamin is essential for podocyte function. During proteinuric kidney disease, induction of cytoplasmic cathepsin L leads to cleavage of dynamin at an evolutionary conserved site, resulting in reorganization of the podocyte actin cytoskeleton and proteinuria. Dynamin mutants that lack the cathepsin L site, or render the cathepsin L site inaccessible through dynamin self-assembly, are resistant to cathepsin L cleavage. When delivered into mice, these mutants restored podocyte function and resolve proteinuria. Our study identifies dynamin as a critical regulator of renal permselectivity that is specifically targeted by proteolysis under pathological conditions.
Subject(s)
Cathepsins/metabolism , Cysteine Endopeptidases/metabolism , Dynamins/metabolism , Kidney Diseases/enzymology , Podocytes/enzymology , Proteinuria/metabolism , Actins/genetics , Actins/metabolism , Animals , Cathepsin L , Cathepsins/genetics , Cells, Cultured , Cysteine Endopeptidases/genetics , Cytoskeleton/genetics , Cytoskeleton/metabolism , Cytoskeleton/pathology , Dynamins/genetics , Kidney Diseases/genetics , Kidney Diseases/pathology , Mice , Mutation , Podocytes/pathology , Proteinuria/genetics , Proteinuria/pathologyABSTRACT
During clathrin-mediated endocytosis, dynamin promotes the formation of clathrin-coated vesicles, but its mode of action is unresolved. In a recent study, Macia and colleagues made use of dynasore, a dynamin-specific inhibitor, to show that dynamin plays a dual role in endocytosis: they confirmed that dynamin is involved in detaching fully formed coated pits from the membrane, and also propose a new role for dynamin earlier in the process at the point of invagination.
