A pull-down and slot blot-based screening system for inhibitor compounds of the podoplanin-CLEC-2 interaction.

Podoplanin, a transmembrane glycoprotein, is overexpressed in certain types of tumors and induces platelet aggregation by binding to C-type lectin-like receptor 2 (CLEC-2) on the platelet membrane. Activated platelets release granule components, which in turn, trigger epithelial-mesenchymal transition and confer invasive capacity to the tumor cells. Therefore, blocking the podoplanin-CLEC-2 interaction by a small-molecule compound is a potential therapeutic strategy to prevent cancer metastasis and invasion. To effectively identify such inhibitory compounds, we have developed a pull-down-based inhibitory compound screening system. An immunoglobulin Fc domain-CLEC-2 fusion protein was used as a bait to capture podoplanin derived from podoplanin-overexpressing HeLa cells in the presence and absence of the test compound. The protein complex was then pulled down using protein A beads. To shorten the turnaround time, increase throughput, and decrease the workload for the operators, centrifugal filter units were employed to separate free and bound podoplanin, instead of using customary aspiration-centrifugation washing cycles. Slot blotting was also utilized in lieu of gel electrophoresis and electrical transfer. Thus, the use of our pull down screening system could facilitate the effective selection of potential inhibitor compounds of the podoplanin-CLEC-2 interaction for cancer therapy. Importantly, our methodology is also applicable to targeting other protein-protein interactions.

Portal venous gas on computed tomography imaging in patients with decompression sickness.

BACKGROUND: It has been reported that portal venous gas is rarely found on computed tomography (CT) imaging in patients with decompression sickness (DCS). However, we propose that this is not true because we have encountered several patients with DCS who presented with portal venous gas on CT before hyperbaric oxygen therapy (HBOT). Here, we review our charts and present these patients' characteristics. CASES: We treated 37 patients with DCS from April 2007 to September 2011. Nine of these 37 patients underwent CT (thoracic, abdominal, or both) on admission because of dyspnea and other reasons. In four of nine patients, portal venous gas was incidentally found on CT. All patients were male, and three of them were SCUBA (self-contained underwater breathing apparatus) divers. Most of the patients did not have abdominal complaints. Three of four patients presented with gas in other abdominal areas (e.g., mesentery or inferior vena cava). HBOT (United States Navy Treatment Table 6) was performed in all patients, and abdominal CT performed after HBOT in three of four patients revealed the complete disappearance of portal venous gas and other venous gases. One patient died, and the remaining patients survived without any complications. CONCLUSIONS: Most patients with DCS do not require CT examination before HBOT. However, if all patients with DCS undergo abdominal CT, the presence of portal venous gas in these patients may no longer be a rare finding. Although routine CT is not required for patients with DCS, it might be helpful for diagnosis.

Acute oral selenium intoxication with ten times the lethal dose resulting in deep gastric ulcer.

A 48-year-old woman presented after taking 2000 mg of selenium dioxide, corresponding to 10 times the experimental lethal dose in animals. She presented with mildly altered consciousness and hematemesis. Endoscopy revealed mucosal damage throughout the oral cavity, esophagus, and stomach. There was no evidence of perforation. After intubation and gastric lavage, hemodialysis was performed. The patient was discharged uneventfully on the 16(th) day. This case highlights a very rare acute selenium intoxication. Serum and urinary selenium levels and serum glutathione peroxidase activities during the patient's course were followed, as well as the mucosal corrosive damage caused by the selenium.