Scope transition and early arterial inflow control provide safe and comfortable dissection in robotic distal pancreatectomy.

PURPOSE: We describe details and outcomes of a novel technique for optimizing the surgical field during robotic distal pancreatectomy (RDP) for distal pancreatic lesions, which has become common with potential advantages over laparoscopic surgery. METHODS: For suprapancreatic lymph node dissection and splenic artery ligation, we used the basic center position with a scope through the midline port. During manipulation of the perisplenic area, the left position was used by moving the scope to the left medial side. The left lateral position is optionally used by moving the scope to the left lateral port when scope access to the perisplenic area is difficult. In addition, early splenic artery clipping and short gastric artery dissection for inflow block were performed to minimize bleeding around the spleen. We evaluated retrospectively the surgical outcomes of our method using a scoring system that allocated one point for blood inflow control and one point for optimizing the surgical view in the left position. RESULTS: We analyzed 34 patients who underwent RDP or R-radical antegrade modular pancreatosplenectomy (RAMPS). The left position was applied in 14 patients, and the left lateral position was applied in 6. Based on the scoring system, only the 0-point group (n = 8) had four bleeding cases (50%) with splenic injury or blood pooling; the other 1-point or 2-point groups (n = 13, respectively) had no bleeding cases (p = 0.0046). CONCLUSION: Optimization of the surgical field using scope transition and inflow control ensured safe dissection during RDP.

Laparoscopic Portal Vein Ligation and Embolization During First-Stage Hepatectomy for Initially Unresectable Colorectal Liver Metastases.

BACKGROUND: Two-stage hepatectomy (TSH) is the only treatment for the patients with multiple bilobar colorectal liver metastases (CRMs) who are not candidates for one-step hepatectomy because of insufficient future remnant liver volume and/or impaired liver function.1-5 Although laparoscopic approaches have been introduced for TSH,6-8 the postoperative morbidity and mortality remains high because of the technical difficulties during second-stage hepatectomy.9,10 The authors present a video of laparoscopic TSH with portal vein (PV) ligation and embolization, which minimizes adhesions and PV thrombosis risk in the remnant liver, thereby facilitating second-stage hepatectomy. METHODS: Three patients with initially unresectable bilateral CRMs received a median of chemotherapy 12 cycles, followed by conversion TSH. After right PV ligation, laproscopic PV embolization was performed by injection of 100% ethanol into the hepatic side of the right PV using a 23-gauge winged needle. After PV embolization, a spray adhesion barrier (AdSpray, Terumo, Tokyo, Japan)11 was applied. RESULTS: During the first stage of hepatectomy, two patients underwent simultaneous laparoscopic colorectal resection (left hemicolectomy and high anterior resection). In the initial hepatectomy, two patients underwent two limited hepatectomies each, and one patient underwent six hepatectomies in the left lobe. After hepatectomy, all the patients underwent right PV embolization. During the second stage, two patients underwent open extended right hepatectomy (right adrenalectomy was performed because of adrenal invasion in one patient), and one patient underwent laparoscopic extended right hepatectomy. No postoperative complications occurred in the six surgeries. CONCLUSIONS: Laparoscopic TSH with PV embolization is recommended for safe completion of the second hepatectomy.

Feasibility of laparoscopic radical antegrade modular pancreatosplenectomy (RAMPS) as a standard treatment for distal resectable pancreatic cancer.

INTRODUCTION: Laparoscopic (Lap-) radical antegrade modular pancreatosplenectomy (RAMPS) is an attractive radical procedure that aims to achieve negative posterior retroperitoneal margin in pancreatic ductal adenocarcinoma (PDAC) resections. However, only few institutions are adapting Lap-RAMPS due to the technical difficulties and the lack of supporting evidence for the clinical applications. METHODS: A retrospective cohort study was performed on consecutive patients who underwent RAMPS for distal resectable PDACs. We analyzed the short- and long-term outcomes including local control and the induction of adjuvant chemotherapy compared between Lap- and Open-RAMPS. RESULTS: Of the 118 RAMPS patients, 43 patients underwent Lap-RAMPS and 75 patients underwent Open-RAMPS. The blood loss was lower (125 vs. 390 mL, p < 0.001), and postoperative hospital stay was shorter (17 vs. 21 days, p = 0.018) in the Lap-RAMPS group. There was no difference in the postoperative complications and no mortality in both groups. R0 resection rate was 100.0% in the Lap-RAMPS and 90.7% in the Open-RAMPS (p = 0.039). Among the patients eligible for adjuvant chemotherapy, the Lap-RAMPS group showed a favorable induction rate (100.0 vs. 89.6%, p = 0.037). Both groups showed a favorable 3-year local recurrence rate (8.7 vs. 10.0%, p = 0.976) and 3-year overall survival (69.8 vs. 71.1%, p = 0.996). CONCLUSIONS: The safety and efficacy of Lap-RAMPS were comparable to those of Open-RAMPS in terms of achieving local control and adjuvant chemotherapy induction. A higher early induction of adjuvant chemotherapy is an advantage of minimally invasive surgery.

The "Tube Submarine Technique": a safe and easy technique to place an external drainage tube during hepaticojejunostomy in minimally invasive surgery.

PURPOSE: Pancreaticoduodenectomy (PD) is a standard procedure for various pancreatic head lesions. Recently, minimally invasive surgery (MIS), including laparoscopic PD (LPD) or robotic PD (RPD), has been widely performed. The hepaticojejunostomy (HJ) technique in MIS is more difficult than that in open procedures, and the placement of an external drainage tube (EDT) is not common in MIS owing to its complicated procedure. Here, we demonstrate the "Tube Submarine Technique" (TST) to facilitate EDT placement without hampering the anastomotic maneuver in MIS. METHODS: After resection of the MIS-PD, the jejunal stump was extracted from the umbilical incision, and a small jejunostomy was performed. A retrograde insertion of the EDT was carried out from this hole towards the jejunal stump. A 4-0 suture was applied through the tip and neighboring side hole, and ligated with a margin of approximately 1-2 cm without needle release. The needle was passed through the anterior jejunal limb wall from the inside to the outside, and the tube was placed into the jejunal limb like a submarine and fixed to the anterior inside wall. After posterior wall suturing during HJ in MIS, the tube-fixing suture was cut immediately below the knot, the tube-like surface of the submarine was pulled up from the jejunal hole and inserted into the bile duct. RESULTS: The procedure of tube fixation inside the jejunal limb and tube surfacing was safe and easy with no complications. CONCLUSION: The TST can significantly help in the placement of an EDT in MIS.

Diagnosis and management of postpancreatectomy hemorrhage: A single-center experience of consecutive 1,096 pancreatoduodenectomies.

BACKGROUND/OBJECTIVES: This study aimed to assess the outcomes and characteristics of post-pancreatectomy hemorrhage (PPH) in over 1000 patients who underwent pancreatoduodenectomy (PD) at a high-volume hepatopancreaticobiliary center. METHODS: This retrospective study analyzed consecutive patients who underwent PD from 2010 through 2021. PPH was diagnosed and managed using our algorithm based on timing of onset and location of hemorrhage. RESULTS: Of 1096 patients who underwent PD, 33 patients (3.0%) had PPH; incidence of in-hospital and 90-day mortality relevant to PPH were one patient (3.0%) and zero patients, respectively. Early (≤24 h after surgery) and late (>24 h) PPH affected 9 patients and 24 patients, respectively; 16 patients experienced late-extraluminal PPH. The incidence of postoperative pancreatic fistula (p < 0.001), abdominal infection (p < 0.001), highest values of drain fluid amylase (DFA) within 3 days, and highest value of C-reactive protein (CRP) within 3 days after surgery (DFA: p < 0.001) (CRP: p = 0.010) were significantly higher in the late-extraluminal-PPH group. The highest values of DFA≥10000U/l (p = 0.022), CRP≥15 mg/dl (p < 0.001), and incidence of abdominal infection (p = 0.004) were identified as independent risk factors for PPH in the multivariate analysis. Although the hospital stay was significantly longer in the late-extraluminal-PPH group (p < 0.001), discharge to patient's home (p = 0.751) and readmission rate within 30-day (p = 0.765) and 90-day (p = 0.062) did not differ between groups. CONCLUSIONS: Standardized management of PPH according to the onset and source of hemorrhage minimizes the incidence of serious deterioration and mortality. High-risk patients with PPH can be predicted based on the DFA values, CRP levels, and incidence of abdominal infections.

Evaluation of local recurrence after pancreaticoduodenectomy for borderline resectable pancreatic head cancer with neoadjuvant chemotherapy: Can the resection level change after chemotherapy?

BACKGROUND: Neoadjuvant treatment has significant survival benefits for patients with pancreatic cancer. However, local recurrence remains a serious issue, even after neoadjuvant treatment. This study investigated local recurrence after pancreaticoduodenectomy and determined the optimal resection level after neoadjuvant treatment. METHODS: This retrospective study analyzed consecutive patients who underwent pancreaticoduodenectomy for borderline resectable pancreatic cancer after 4 cycles of neoadjuvant treatment-gemcitabine plus nab-paclitaxel between April 2015 and March 2020. Patients with borderline resectable-artery pancreatic cancer were classified according to the dissection level around the artery: level 3 group, hemi-, or whole circumferential arterial nerve plexus was dissected; and level 2 group, the nerve plexus was preserved. RESULTS: Fifty-six patients with borderline resectable-artery pancreatic cancer underwent pancreaticoduodenectomy after neoadjuvant treatment (level 3 group, n = 40; level 2 group, n = 16). The resection level in the level 2 group was changed based on post-neoadjuvant treatment computed tomography images or intraoperative frozen section diagnosis. The overall and local recurrence rates were significantly higher in the level 2 group than in the level 3 group (overall recurrence, 93.8% vs 70.0%; P = .037) (local recurrence, 50.0% vs 5.0%; P < .001). Ten patients experienced local recurrence, of which 8 belonged to the level 2 group. Among them, 4 patients were confirmed as cancer-negative by surgical margin analysis or intraoperative frozen section diagnosis but experienced recurrence around the arteries. CONCLUSION: For treating borderline resectable-artery pancreatic cancer, changing the resection level based on post-neoadjuvant treatment computed tomography images increased the risk of local recurrence. All patients with borderline resectable-artery should undergo level 3 dissection, regardless of the response to neoadjuvant treatment.

Optimizing the selection of technically unresectable colorectal liver metastases.

BACKGROUND: The prediction of conversion surgery in patients with technically unresectable colorectal liver metastases has not been generalized or well-established. We developed a predictive model for conversion surgery and assessed the long-term outcomes of patients with technically unresectable colorectal liver metastases. METHODS: In this single-center, retrospective study, we analyzed the perioperative parameters and outcomes of 892 consecutive patients (2014-2021). Conversion surgery was indicated when the chemotherapy response allowed the complete resection of colorectal liver metastases with negative margins and adequate remnant liver volume. RESULTS: Of the 892 patients, 122 had technically unresectable colorectal liver metastases; 61 underwent conversion surgery (conversion surgery group) and 61 did not (nonconversion surgery group). The median overall survival was significantly higher in the conversion surgery group than in the nonconversion surgery group (5.6 vs 1.8 years, P < .001). After univariate and multivariate analyses, the predictive model for conversion surgery was constructed using 4 predictive factors: Rat sarcoma viral oncogene homolog status (mutant, +2 points), tumor number (≥15, +1), hepatic vein contact (≥2 hepatic veins, +1), and the presence of preservable sections (absence of preservable sections, +2). The area under the curve for conversion surgery was 0.889. Patients were graded according to the scores (A [0-2], B [3-4], and C [5-6]), and the conversion rates were 91.5% (A), 32.6% (B), and 10.3% (C) (P < .001). Grade A patients (median survival time, 5.7 years) had significantly better overall survival than grade B and C patients (median survival time, 2.2 and 1.6 years, respectively; P < .001). CONCLUSION: Patients who underwent conversion surgery for technically unresectable colorectal liver metastases had better prognoses, and our novel predictive model was useful in predicting conversion surgery and prognosis.

A new technique to avoid unintentional adhesion while deploying ProGrip mesh and its utility in the laparoscopic repair of obturator hernia.

The ProGrip™ laparoscopic self-fixating mesh provides advantages such as low cost and reduced pain following tack-free fixation in laparoscopic hernia repair through a transabdominal preperitoneal approach. Obturator hernia repair needs adequate fixation around the hernial orifice without the use of tacking, and ProGrip™ mesh provides options for secure fixation. However, it is often difficult to adequately adjust the mesh placement to cover the obturator hernia orifice with a ProGrip™ mesh, due to adhesion of the grips to the surrounding tissues. We introduce our technique to avoid unintentional adhesion during ProGrip mesh repair and discuss its utility in the treatment of obturator hernias. We repaired seven obturator hernia lesions in five patients using this technique without any complications. The biggest advantage of our technique is that the position of the mesh can be adjusted after it is expanded, unless the sheet is completely removed, allowing the surgeons to fix the mesh without any unintended adhesion to surrounding tissue.

Perforation of small intestinal metastasis of lung adenocarcinoma treated with pembrolizumab: a case report.

BACKGROUND: Pembrolizumab is an immune checkpoint inhibitor and is an anti-human programmed cell death-1 (PD-1) monoclonal antibody. Pembrolizumab is used for non-small cell lung carcinoma with high programmed cell death ligand-1 (PD-L1) expression. It has been found that better overall survival can be obtained using pembrolizumab compared to the existing chemotherapy. We report a case of perforation of small intestinal metastasis after pembrolizumab treatment. CASE PRESENTATION: A 62-year-old man was treated by pembrolizumab for PD-L1 highly expressed lung adenocarcinoma, with multiple metastasis (small intestinal, lymph nodes, and bone). The treatment was stopped owing to drug-induced pneumonitis. One month after drug withdrawal, the patient visited the emergency department of our hospital with the complaint of severe stomachache. He had a rigid abdomen and generalized tenderness, and computed tomography scans showed free air within the abdomen. We diagnosed bowel perforation and performed emergency surgery. Surgical findings revealed multiple small intestine metastasis and mesenteric lymph node metastasis. Perforation was found in the metastatic site in the jejunum located around 40 cm anal to Treitz's ligament. This perforated part was resected, and functional end-to-end anastomosis was performed using linear staplers. The post-operative course was uneventful. Pathological examination revealed lung adenocarcinoma metastasis at the perforation site, and the effectiveness of pembrolizumab was grade 1b (Japanese Classification of the Colorectal Carcinoma, seventh edition). CONCLUSIONS: This is the first report of perforation of small intestinal metastasis of lung adenocarcinoma after pembrolizumab treatment. Because pembrolizumab causes some side effects, particularly autoimmune side effects, careful attention during treatment is warranted.

Hashimoto's encephalopathy mimicking a brain tumor and its pathological findings: A case report.

Hashimoto's encephalopathy is characterized by the presence of anti-thyroid antibodies with no alternative cause. Patients with Hashimoto's encephalopathy present with various clinical symptoms and magnetic resonance imaging (MRI) findings. To our knowledge, this is the first documented report of Hashimoto's encephalopathy with MRI findings mimicking a brain tumor. The patient was a 41-year-old woman with a history of Hashimoto's disease. She experienced gradually worsening Parkinsonism and an MRI revealed a brain tumor-like lesion at the left caudate nucleus. She underwent a brain biopsy that revealed diffuse gliosis and perivascular lymphocyte infiltration with CD3+ T-cell predominance. No pathological signs of a brain tumor were found. Hashimoto's encephalopathy was suspected based on the patient's history and the presence of anti-thyroid antibodies. Her symptoms and the MRI findings improved with glucocorticoid treatment. Although there exist only a few studies on the pathology of Hashimoto's encephalopathy, our findings were consistent with those of previous reports. Our findings suggest cerebral vasculitis as an underlying etiology of Hashimoto's encephalopathy. We also emphasize the importance of considering Hashimoto's encephalopathy as a differential diagnosis of brain tumors.

Therapeutic activity of retroviral replicating vector-mediated prodrug activator gene therapy for pancreatic cancer.

Toca 511, a retroviral replicating vector (RRV) encoding the yeast cytosine deaminase (yCD) prodrug activator gene, which mediates conversion of the prodrug 5-fluorocytosine (5-FC) to the anticancer drug 5-fluorouracil (5-FU), is currently being evaluated in Phase II/III clinical trials for glioma, and showing highly promising evidence of therapeutic activity. Here we evaluated RRV-mediated prodrug activator gene therapy as a new therapeutic approach for pancreatic ductal adenocarcinoma (PDAC). RRV spread rapidly and conferred significant cytotoxicity with prodrug in a panel of PDAC cells. Efficient intratumoral replication and complete inhibition of tumor growth upon 5-FC administration were observed in both immunodeficient and immunocompetent subcutaneous PDAC models. Biodistribution of RRV was highly restricted in normal tissues, especially in immunocompetent hosts. Tumor growth inhibition by Toca 511 followed by 5-FC was also confirmed in the orthotopic PDAC model. This study provides the first proof-of-concept for application of Toca 511 and Toca FC (extended release 5-FC) to the treatment of human PDAC, and provided support for inclusion of PDAC in a Phase I study evaluating Toca 511 in various systemic malignancies, (NCT02576665), which has recently been initiated.

Long-term survival after repeated resection of metachronous lung metastases from pStage IA pancreatic adenocarcinoma.

CASE REPORT: A 70-year-old woman with pancreatic ductal adenocarcinoma was initially treated by distal pancreatectomy (DP). Thirty-five months later, another tumor appeared in the pancreatic head and was treated by pancreaticoduodenectomy. Histopathological findings identified both tumors as pancreatic ductal adenocarcinoma pStage IA. Computed tomography (CT) of the chest 16 months after the second pancreatectomy revealed a ground-glass opacity in segment 3 of the right lung. Chest CT 23 months after the second pancreatectomy revealed a nodular shadow in segment 1a of the right lung. Chest CT 39 months after the second pancreatectomy revealed a nodular shadow in segment 5 of the left lung. These lesions were treated by video-assisted thoracoscopic surgery partial resection. Histopathological and immunohistochemical features (positive for cytokeratin (CK)7 and CK20, negative for transcription factor-1) for these three lesions and the secondary pancreatic ductal adenocarcinoma were similar, indicating a diagnosis of lung metastasis from the second pancreatic ductal adenocarcinoma. The patient has remained alive and free of new metastases for 8 years after initial DP, 3 years after the last lung resection. CONCLUSION: This patient has survived over the long term after undergoing three resections of lung metastases from resected pancreatic ductal adenocarcinoma.

Overexpression of C16orf74 is involved in aggressive pancreatic cancers.

Clinical outcome of pancreatic ductal adenocarcinoma (PDAC) has not been improved in the last three decades due to the lack of effective molecular-targeted drugs. To identify a novel therapeutic target for PDAC, we have performed genome-wide anamysis and found that Homo sapienschromosome 16 open reading frame 74 (C16orf74) was up-regulated in the vast majority of PDAC. Overexpression of C16orf74protein detected by immunohistochemical analysis was an independent prognostic factor for patients with PDAC. The knockdown of endogenous C16orf74 expression in the PDAC cell lines KLM-1 and PK-59 by vector-based small hairpin-RNA (shRNA) drastically attenuated the growth of those cells, whereas ectopic C16orf74 overexpression in HEK293T and NIH3T3 cells promoted cell growth and invasion, respectively. More importantly, the endogenous threonine 44 (T44)-phosphorylated form of C16orf74 interacted with the protein phosphatase 3 catalytic subunit alpha (PPP3CA) via the PDIIIT sequence in the PPP3CA-binding motif within the middle portion of C16orf74 in PDAC cells. The overexpression of mutants of C16orf74 lacking the PDIIIT sequence or T44 phosphorylation resulted in the suppression of invasive activity compared with wild-type C16orf74, indicating that their interaction should be indispensable for PDAC cell invasion. These results suggest that C16orf74 plays an important role for PDAC invasion and proliferation, and is a promising target for a specific treatment for patients with PDAC.

Molecular targeting of cell-permeable peptide inhibits pancreatic ductal adenocarcinoma cell proliferation.

BACKGROUND: Chromosome 16 open reading frame 74 (C16orf74) is highly expressed in pancreatic ductal adenocarcinoma (PDAC) and is involved in cancer cell proliferation and invasion through binding to calcineurin (CN). Therefore, C16orf74 is a good target for the development of a PDAC treatment. A cell-permeable dominant-negative (DN) peptide that can inhibit the C16orf74/CN interaction was designed to examine whether this peptide can inhibit PDAC cell proliferation in vitro and in vivo. METHOD: TheDN-C16orf74 peptide, which corresponds to the portion of C16orf74 that interacts with CN, was synthesized, and we assessed its anti-tumor activity in proliferation assays with human PDAC cells and the underlying molecular signaling pathway. Using an orthotopic xenograft model of PDAC, we treated mice intraperitoneally with phosphate-buffered saline (PBS), control peptide, or DN-C16orf74 and analyzed the tumor-suppressive effects. RESULT: DN-C16orf74 inhibited the binding of C16orf74 to CN in an immunoprecipitation assay. DN-C16orf74 suppressed PDAC cell proliferation, and the level of suppression depended on the expression levels of C16orf74 in vitro. DN-C16orf74 also exhibited anti-tumor effects in orthotopic xenograft model. Furthermore, the tumor-suppressive effect was associated with inhibition of the phosphorylation of Akt and mTOR. CONCLUSION: The cell-permeable peptide DN-C16orf74 has a strong anti-tumor effect against PDAC in vitro and in vivo.

Noninvasive management for iatrogenic splenic injury caused by chest tube insertion: a case report.

Splenic injury is one of the most critical complications of chest tube insertion and often requires invasive emergency management. However, noninvasive management such as delayed removal of the malpositioned tube may be considered for a stable patient without severe adverse event.

Inhibition of Eph receptor A4 by 2,5-dimethylpyrrolyl benzoic acid suppresses human pancreatic cancer growing orthotopically in nude mice.

Ephrin receptor A4 (EphA4) is overexpressed in human pancreatic adenocarcinoma (PDAC) and activate cell growth. Recent studies have identified small molecules that block EphA4. In this study, we investigated the correlation between EphA4 expression and the prognosis of patients with PDAC. We also examined the cytostatic efficacy of 2,5-dimethylpyrrolyl benzoic acid (compound 1), a small molecule that blocks EphA4, in PDAC cells. Overall survival of patients with EphA4 positivity was significantly shorter than that of patients with EphA4 negativity (P = 0.029). In addition, multivariate analysis revealed that EphA4 expression was an independent prognostic factor in PDAC patients (P = 0.039). Compound 1 showed a cytostatic efficacy in PDAC cells expressing EphA4 in vitro and in vivo. Our study indicated that compound 1 suppressed both EphA4 and Akt phosphorylations, and induced apoptosis in PDAC cells expressing EphA4. In conclusion, compound 1 has a high potential as a therapeutic agent for patients with PDAC.

Serum miR-124 up-regulation as a disease marker of toxic epidermal necrolysis.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a lethal complication of drugs, thus early diagnosis and treatment are important. However, there are no satisfactory clinical biomarkers of TEN. OBJECTIVES: We investigated miR-124 and miR-214 expressions in serum and skin tissues of severe drug eruptions to evaluate the possibility of biomarkers of TEN. MATERIALS & METHODS: microRNAs were extracted from serum and skin tissues. Serum samples were obtained from 7 TEN patients, 5 Stevens-Johnson syndrome (SJS) patients, 11 erythema multiforme (EM) minor patients and 21 healthy volunteers. Skin tissues were obtained from 4 TEN patients, 3 SJS patients, 8 EM minor patients, 3 psoriasis and 3 atopic dermatitis patients. Six control skin samples were obtained. MicroRNA concentrations were determined by PCR array and real-time PCR. RESULTS: The concentrations of miR-124 in sera from TEN were significantly higher than those from healthy controls. In the characteristics curve analysis of serum miR-124 for differentiating TEN patients from normal subjects, the area under curve was 0.94. The serum miR-124 concentration was strongly correlated with the erosion area and the SCORTEN scale. The expression of miR-214 was significantly increased in the skin of TEN. CONCLUSION: The serum miR-124 concentration can be used as a disease activity marker for severe drug eruptions, reflecting the severity of keratinocyte apoptosis.

Effect of protein-encapsulation on thermal structural stability of liposome composed of glycosphingolipid/cholesterol/phospholipid.

We have studied the thermal structural stability of liposomes encapsulating proteins by using synchrotron radiation small- and wide-angle X-ray scattering (SR-SWAXS). Liposomes are known to be effective drug-delivery systems (DDSs) because they can reduce drug toxicity due to biodegradability and biocompatibility and can offer promising carriers of various types of drugs. However, in spite of numerous studies of liposomes, physicochemical characteristics of liposomes entrapping proteins are rarely known. The liposome studied is characterized by the lipid composition (mixture of acidic glycosphingolipid (ganglioside)/cholesterol/phospholipid). Gangliosides are one of the major constituents of so-called lipid rafts playing the role of a platform of cell-signaling. We have found that the encapsulation of proteins elevates the thermal transition temperature of the liposome membrane and suppresses the deformation of its shape. The present results suggest that not only membrane proteins, but also water-soluble proteins affect liposome stability through the revalence between osmotic pressure and membrane elasticity. In addition, we have found the presence of the size-effect depending on the molar content of gangliosides in the liposome, indicating the ability of ganglioside molecule controlling both the size and effective surface charge of the liposome. The present results would have significance from two different points of view. One is the confinement effect of proteins within a limited space like cell, and the other is a stability of a new type of DDS using gangliosides. Due to the intrinsic properties, gangliosides are expected to be promising agents for targeting and long-circulation properties of liposomal DDSs.