Background: La Crosse virus (LACV), family Bunyaviridae, was first identified as a human pathogen in 1960 after its isolation from a 4 year-old girl with fatal encephalitis in La Crosse, Wisconsin. LACV is a major cause of pediatric encephalitis in North America and infects up to 300,000 persons each year of which 70-130 result in severe disease of the central nervous system (CNS). As an initial step in the establishment of useful animal models to support vaccine development, we examined LACV infectivity, pathogenesis, and immunogenicity in both weanling mice and rhesus monkeys.

Protection against infection is the hallmark of immunity and the basis of effective vaccination. For a variety of reasons there is a great demand to develop new, safer and more effective vaccine platforms. In this regard, while ‘first-generation’ DNA vaccines were poorly immunogenic, new genetic ‘optimization’ strategies and the application of in vivo electroporation (EP) have dramatically boosted their potency. We developed a highly optimized plasmid DNA vaccine that expresses the lymphocytic choriomeningitis virus (LCMV) nucleocapsid protein (NP) and evaluated it using the LCMV challenge model, a gold standard for studying infection and immunity. When administered intramuscularly with EP, robust NP-specific cellular and humoral immune responses were elicited, the magnitudes of which approached those following acute LCMV infection. Furthermore, these responses were capable of providing 100% protection against a high-dose, normally lethal virus challenge. This is the first non-infectious vaccine conferring complete protective immunity up to eight weeks after vaccination and demonstrates the potential utility of ‘next-generation’ DNA vaccines.

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A 31-year-old male presented with acute foreign-body ingestion. He reported swallowing a table knife 2 h prior to his arrival. He had a history of post-traumatic stress disorder and multiple prior foreign-body ingestions requiring endoscopic and surgical extraction. Previous ingestions included pens and a mechanical pencil. He appeared in no acute distress. His physical exam was unremarkable other than for multiple well-healed abdominal incisions. A rectal exam was performed, and the patient's stool found to be heme-occult negative.Chest X-ray (Figs 1 and 2) revealed a metallic knife at the gastroesophageal junction with the handle oriented inferiorly. Emergent esophagogastroduodenoscopy was performed under general anesthesia with overtube insertion. A table knife was identified in the mid-esophagus. It was grasped with a snare and then drawn into the overtube. The scope and overtube were then carefully withdrawn. The snare slipped off the knife, leaving the knife partially in the proximal esophagus and posterior pharynx. The anesthetists removed the knife with a laryngoscope and McGill forceps. After removal of the knife, the endoscope was reintroduced for careful examination. There was minimal trauma to the esophagus in the location where the knife was removed. There was no active bleeding at any time throughout the procedure. Post-extraction, the table knife was measured to be 21 cm in length.