[A Case of Pappilary Renal Cell Caircinoma which Responded Well to the Combination Therapy of Ipilimumab and Nivolumab --A CASE REPORT-].

We report a case of papillary renal cell carcinoma that responded well to the combination of ipilimumab and nivolumab. The patient was a 68-year-old male who was being followed up for a small left renal mass without treatment. Two years later, computed tomography (CT) showed enlarged cervical and para-aortic lymph nodes, and lymph node biopsy suggested metastases of the cancer. After resection of the renal tumor, we performed pararenal aortic lymph node biopsy, and we diagnosed the case as papillary renal cell carcinoma type 1 with lymph node metastasis. The combination of ipilimumab and nivolumab each metastatic site showed regression on CT. Since immune-related adverse events occurred during the therapy nivolumab was discontinued, but partial response of the metastases was maintained.

[A Case of Robot-Assisted Radical Cystoprostatectomy for Locally Advanced Prostate Cancer with Bladder Infiltration].

While robot-assisted radical cystoprostatectomy (RARC) for locally advanced prostate cancer (LAPC) may sometimes prove to be excessive treatment, it can significantly reduce the risk of positive surgical margins and lower urinary tract obstruction in some cases. Here, we report a case of LAPC treated with RARC in a patient with right hydronephrosis due to bladder infiltration and left hypoplastic kidney. A 71-year-old man presented with frequent urination in August 2019. Prostate-specific antigen (PSA) level was 8.633 ng/ml, and magnetic resonance imaging led to the suspicion that the prostate cancer extended beyond the prostate capsule without distant metastasis. Prostatic biopsy revealed Gleason score 10 (5＋5) adenocarcinoma in 8 out of 8 specimens. We diagnosed left hypoplastic kidney and LAPC with right hydronephrosis due to bladder infiltration. We performed percutaneous right nephrostomy and started neoadjuvant hormone therapy. RARC and intracorporeal ileal conduit were performed in March 2020. The prostate was adherent to the anterior surface of the rectum and was difficult to remove. At present, five months after the surgery, the patient remains free of recurrence and metastasis with PSA level ＜0.003 ng/ml. RARC for LAPC with bladder infiltration can be an effective therapeutic strategy in some cases.

Cellular vacuolation induced by Clostridium perfringens epsilon-toxin.

The epsilon-toxin of Clostridium perfringens forms a heptamer in the membranes of Madin-Darby canine kidney cells, leading to cell death. Here, we report that it caused the vacuolation of Madin-Darby canine kidney cells. The toxin induced vacuolation in a dose-dependent and time-dependent manner. The monomer of the toxin formed oligomers on lipid rafts in membranes of the cells. Methyl-ß-cyclodextrin and poly(ethylene glycol) 4000 inhibited the vacuolation. Epsilon-toxin was internalized into the cells. Confocal microscopy revealed that the internalized toxin was transported from early endosomes (early endosome antigen 1 staining) to late endosomes and lysosomes (lysosomal-associated membrane protein 2 staining) and then distributed to the membranes of vacuoles. Furthermore, the vacuolation was inhibited by bafilomycin A1, a V-type ATPase inhibitor, and colchicine and nocodazole, microtubule-depolymerizing agents. The early endosomal marker green fluorescent protein-Rab5 and early endosome antigen 1 did not localize to vacuolar membranes. In contrast, the vacuolar membranes were specifically stained by the late endosomal and lysosomal marker green fluorescent protein-Rab7 and lysosomal-associated membrane protein 2. The vacuoles in the toxin-treated cells were stained with LysoTracker Red DND-99, a marker for late endosomes and lysosomes. A dominant negative mutant of Rab7 prevented the vacuolization, whereas a mutant form of Rab5 was less effective. These results demonstrate, for the first time, that: (a) oligomers of epsilon-toxin formed in lipid rafts are endocytosed; and (b) the vacuoles originating from late endosomes and lysosomes are formed by an oligomer of epsilon-toxin.