Rheumatoid arthritis associated vasculitis: a rare entity; case and review.

We present a case of a 60-year-old male with known seropositive rheumatoid arthritis and cerebral vasculitis who presented to the emergency room with abrupt onset lower back and abdominal pain. The patient developed peritonitis which led to an abdominal laparotomy where jejunal ischemia, necrosis, and perforation were found, requiring bowel resection. On pathology examination, the patient had mesenteric vessel intramural inflammation indicative of vasculitis.

Single molecule FRET investigation of pressure-driven unfolding of cold shock protein A.

We demonstrate that fused silica capillaries are suitable for single molecule fluorescence resonance energy transfer (smFRET) measurements at high pressure with an optical quality comparable to the measurement on microscope coverslips. Therefore, we optimized the imaging conditions in a standard square fused silica capillary with an adapted arrangement and evaluated the performance by imaging the focal volume, fluorescence correlation spectroscopy benchmarks, and FRET measurements. We demonstrate single molecule FRET measurements of cold shock protein A unfolding at a pressure up to 2000 bars and show that the unfolded state exhibits an expansion almost independent of pressure.