Dab1‐mediated colocalization of multi‐adaptor protein CIN85 with Reelin receptors,ApoER2 and VLDLR,in neurons

Reelin‐Dab1 signaling is indispensable for proper positioning of neurons in mammalian brain. Reelin is a glycoprotein secreted from Cajal‐Reztuis cells in marginal zone of cerebral cortex, and its receptors are Apolipoprotein E receptor 2 (ApoER2) or very low density lipoprotein receptor (VLDLR) expressed on migrating neurons. When Reelin binds to ApoER2 or VLDLR, an adaptor protein Dab1 bound to the receptors undergoes Tyr phosphorylation that is essential for Reelin signaling. We reported previously that Cdk5‐p35 phosphorylates Dab1 at Ser400 and Ser491 and the phosphorylation regulates its binding to CIN85, which is an SH3‐containing multiadaptor protein involved in endocytic downregulation of receptor‐tyrosine kinases. However, the interaction of CIN85 with Dab1 has not been addressed in neurons. We examined here a possibility that CIN85 has a role in Reelin signaling. We found nonpho‐sphorylated Dab1‐mediated colocalization of CIN85 with ApoER2. The colocalization of CIN85 with ApoER2 was increased in neurons stimulated with Reelin repeats 3‐6, an active Reelin fragment. The stimulation recruited CIN85 to domains in plasma membrane where it colocalized with ApoER2 and Dab1 and then to EEA1‐labeled early endosomes in the cytoplasm. In addition, Tyr phosphorylation of Dab1 strengthened the binding to CIN85. These results suggest that CIN85 participates in Reelin signaling through the binding to Dab1.     

In vitro evaluation of phosphate,bicarbonate, and hepes buffered storage solutions on hypothermic injury to immature myocytes

Summary In this study we evaluated cardiac myocyte viability and function under hypothermic conditions using three types of buffer solutions: phosphate buffer solution (PBS), Krebs-Henseleit bicarbonate buffer solution (KHB), and Hepes buffered minimum salt solution (MSS). As a control, normal saline solution (NSS) was used. Cardiac myocytes were isolated from neonatal rat ventricles. Myocytes (12.5 × 10⁵ myocytes/culture flask) were then incubated at 4°C for 6, 12, 18, and 24 hours in various buffer solutions. After each incubation time, CPK and LDH were measured. The myocytes were then incubated for an additional 24 hours at 37°C to evaluate the recovery of the myocyte beating rate. Group MSS had a significantly better beating rate recovery than group NSS (control) after 18 hours (MSS, 32.7%, NSS, 0.0% of control; i.e., beating rate prior to hypothermic incubation). In contrast, group KHB showed a significantly lower recovery ratio than group NSS at 12 hours (41.0%, 78.8%, respectively), and the lowest recovery was observed in group PBS beginning at 6 hours of hypothermic incubation (27.6%). Group MSS significantly suppressed the release of CPK and LDH compared to group NSS at 24 hours (MSS, 246.7 and 440.2 mIU/flask; NSS, 369.7 and 821.3 mIU/flask, respectively). In contrast, groups PBS and KHB showed significantly increased CPK and LDH levels compared to group NSS after 12 hours (PBS, 388.6 and 721.4 mIU/flask; KHB, 340.5 and 540.5 mIU/flask; NSS, 91.5 and 222.7 mIU/flask, respectively). In conclusion, Hepes buffer has cytoprotective characteristics that may be suitable for long-term hypothermic preservation of immature myocardium compared to phosphate or bicarbonate buffer.     

Initial characterization of Ikari Guide catheter for transradial coronary intervention

Ikari is a new guide catheter for transradial intervention (TRI) that produces stronger back-up force by utilizing an unfavorable angle between the subclavian and brachiocephalic arteries. We report the initial results of the Ikari guide catheter based on the experience of a single center. Six operators performed a total of 102 coronary interventions for 91 patients using the Ikari guide catheter, while 101 interventions were performed with the transfemoral approach (TFI) during the same period. A left Ikari catheter was used in 63 procedures, and a right Ikari catheter was used in 39. The success rate for the procedure was 97% with a 6 French Ikari catheter. All failures were due to tortuous brachiocephalic arteries. For the Ikari procedure, the average fluorescence time was 14.5 9.5 minutes and the dye volume used was 153 53 ml; these results were equal to or better than those of TFI during the same period (20.1 12.2 minutes and 184 61 ml, respectively). These preliminary data suggest that an acceptable success rate can be achieved in TRI using appropriate guides, such as an Ikari catheter.     

Double cancers in the common bile duct: molecular genetic findings with an analysis of LOH

We report a 69‐year‐old man with double cancers in the common bile duct. One cancer was located between the superior and middle parts of the bile duct, while the other cancer was in the inferior part of the bile duct. Pylorus‐preserving pancreatoduodenectomy was performed. There was no communication between the two cancers in either the mucosal layer or the subepithelial layer. On pathological examination, the upper cancer was diagnosed as poorly differentiated adenocarcinoma, while the lower one was found to be moderately differentiated adenocarcinoma. We analyzed loss of heterozygosity (LOH), using microsatellite markers on five chromosomal arms, in both the upper and the lower cancers. Both cancers showed common regions of LOH at 5q, 6q, 9p, 17p, and 18q, whereas the upper cancer showed one additional region of LOH at 8p, thus suggesting progression, due to the acquisition of the additional LOH, in the upper cancer. No LOH was observed in the region between the two cancers. The presence of one additional LOH in the upper cancer suggests that the upper cancer was a metastasis of the lower one.     

Case of primary cutaneous Aspergillus caldioustus infection caused by nerve block therapy

We report a case of primary cutaneous Aspergillus caldioustus infection caused by nerve block therapy. A 67-year-old Japanese woman had been treated with oral predonisolon and tacrolimus for adult-onset Still disease and interstitial pneumonia. She presented with a 2-month-history of the lesions on the left back. A biopsy specimen from the skin lesion revealed granulomatous inflammation with hyphae. Culture of the pus and the skin specimen confirmed the diagnosis of cutaneous Aspergillus infection. The sequence of β- tubulin gene was analyzed to confirm the mycological diagnosis and the causative agent was identified as A. caldioustus. The patient was treated with surgical removal of the lesions and oral 200 mg/day itraconazole but she died of infectious interstitial pneumonia due to Pneumocystis jiroveci and Cytomegalovirus infection Percutaneous infection may have been responsible for the incidence of localized infection. There was no evidence of systemic aspergillosis. A. caldioustus is an emerging opportunistic fungal pathogen in immunocompromised patients. Immunocompromised patients who have persistent traumatic atypical skin lesion need to be ruled out of such rare fungus infection. An opportunistic infection in Immunocompromised patients can be life-threatening and prompt treatment based on accurate diagnosis is important.