Refractory Acute Antibody Mediated Rejection in Liver Transplant After Desensitization of Preformed Donor Specific Antibody-Validity of Bortezomib and Everolimus: A Case Report.

Here, we report a case of living donor liver transplantation (LDLT) complicated with severe acute antibody-mediated rejection (aAMR), although desensitization was performed for preformed donor-specific anti-human leukocyte antigen antibody (DSA). LDLT was performed in a 59-year-old woman with alcoholic cirrhosis with a graft from her 60-year-old husband as a living donor. She had reproductive history of 4 gravidity and parity with her husband. Preoperative serologic studies showed positive complement-dependent cytotoxic crossmatch and anti-human leukocyte antigen-A26 antibody was identified as DSA. Desensitization for preformed DSA with rituximab and plasma exchange was performed before LDLT. We decided to perform LDLT using her husband right liver as living donor graft since the DSA mean fluoro-intensity was down to negative range. The immunosuppressive regimen was comprised with steroid and tacrolimus. However, the recipient developed acute cellular rejection on day 5 after LDLT, followed by severe aAMR. Re-administration of rituximab followed by 4 courses of plasma exchange failed to treat aAMR. The DSA mean fluoro-intensity was successfully suppressed after bortezomib was administered however impaired serologic liver function test and cholestasis were remained. The liver function test and cholestasis in the graft were improved after Everolimus was administered. The recipient was discharged on postoperative day 196. In conclusion, we report a case of LDLT who developed aAMR after desensitization of preformed DSA and was successfully treated with intensive therapy with bortezomib and everolimus.

The Efficacy of S-1 as Adjuvant Chemotherapy for Resected Biliary Tract Carcinoma: A Propensity Score-Matching Analysis.

Even though S-1 is a widely used chemotherapeutic agent, there is no evidence for its use in an adjuvant setting for biliary tract carcinoma (BTC). Patients who underwent surgical treatment for BTC between August 2007 and December 2018 were selected. Propensity score matching was performed between patients who received S-1 as adjuvant chemotherapy (S-1 group) and those who underwent surgical treatment alone (observation group). Of 170 eligible patients, 38 patients were selected in each group after propensity score matching. Among those in the matched cohort, both the median recurrence-free survival (RFS) and overall survival (OS) in the S-1 group were significantly longer than those in the observation group (RFS, 61.2 vs. 13.1 months, p = 0.033; OS, not available vs. 28.2 months, p = 0.003). A multivariate analysis of the OS revealed that perineural invasion and adjuvant S-1 chemotherapy were independent prognostic factors. According to a subgroup analysis of the OS, the S-1 group showed significantly better prognoses than the observation group among patients with perineural invasion (p < 0.001). S-1 adjuvant chemotherapy might improve the prognosis of BTC, especially in patients with perineural invasion.

[A Case of Locally Advanced, Pancreatic Mixed Acinar-Endocrine Carcinoma(MAEC) Resected using Superficial Femoral Vein Grafts for Portal Reconstruction].

A 46-year-old woman with epigastric pain was found to have a tumor of the pancreatic head. Computed tomography(CT) revealed a plethoric and poorly-marginated, 7 cm tumor in the pancreatic head. The superior mesenteric vein(SMV)was infiltrated from the duodenal inferior margin and a 6 cm occlusion extended to the merger with the splenic vein. Diagnostic criteria identified locally advanced pancreatic cancer(UR-P)with a limitation in portal reconstruction. Endoscopic ultrasoundguided fine needle aspiration(EUS-FNA)diagnosed mixed acinar-endocrine carcinoma(MAEC). Due to rarity, a chemotherapy protocol has not been established. Thus, the first option for treatment was resection. CT showed that the required graft was 7 cm in length, with SMV 0.5 cm in diameter at the intestinal side and 1.4 cm in diameter at the hepatic side; accordingly, the superficial femoral vein (SFV)was selected for use. Compared to the external iliac vein, the graft is slightly thinner and about 10 cm can be harvested. This graft is useful for cases that require reconstruction of the distal SMV.

[Portal Stent for Gastrointestinal Bleeding Caused by Portal Stenosis after Hepato-Biliary-Pancreatic Surgery].

It is known that gastrointestinalbl eeding occurs due to portalstenosis as a complication in the hepato-biliary-pancreatic region at later postoperative stages. Our department has treated 5 portal stent cases since 2015. The pressure difference between the hepatic side and intestinalside at the portalstenosis site decreased from 9-14(median: 10)cmH2O to 0-6 (median: 2)cmH2O in all cases before and after placement of the stent, resulting in hemostasis(observation period 4-18 months, median: 12 months). In surgery of the hepato-biliary-pancreatic regions, veins flowing into the portal vein are also incised by dissection of the hepatoduodenal ligament. Accordingly, it has been inferred that when the portal vein becomes stenotic, the collateralroutes flow into the portalvein at the hepatic portalsite in a hepatopetalmanner through the cholangiojejunal anastomosis site from the mesenteric veins of the elevated jejunum, and the submucosal weak collateral routes collapse, causing gastrointestinal bleeding. Rebleeding is highly likely in cases with only endoscopic treatment and embolization of collateralroutes. On the other hand, it is thought that portalstenting is a radicaltreatment and is thus the first option for management.

[A Case of Splenic Lymph Node Metastasis from the Distal Bile Duct Carcinoma Seven Years after a Curative Resection].

We report a case of splenic lymph node recurrence 7 years after a distal bile duct carcinoma. A 70s man underwent pylorus ring-preserving pancreaticoduodenectomy for distal bile duct carcinoma in 20XX. The pathological diagnosis was T2N0M0, Stage Ⅱ(Japanese Classification of the Biliary Tract Cancers 5th edition). Then, S-1 was administered as an adjuvant chemo- therapy 1month later and continued for 3 years. At 7 years postoperatively, the serum CEA level was elevated(CEA 77.0 ng/ mL), and FDG-PET showed high-grade accumulation in the splenic hilum lymph node, which was diagnosed as lymph node recurrence. Because it was a solitary metastasis and had a long recurrence-free period, tumor resection was not performed, and the patient opted for a nonsurgicaltreatment. No recurrence occurred to date. Recurrent resection is rarely performed for splenic lymph node metastasis.

[Conversion Surgery after Etoposide/Cisplatin(EP)Therapy for Huge Pancreatic Neuroendocrine Carcinoma - A Case Report].

Neuroendocrine carcinoma(NEC)is known as rapid tumor growth, high grade malignancy and poor prognosis. We report a case of huge pancreatic NEC successfully performed conversion surgery after EP therapy. A 70-year-old female, was presented to our hospital with appetite loss. CT scan revealed huge tumor, 15 cm in diameter, locating at the pancreas with possible involvement to liver, stomach, common hepatic artery, left gastric artery and gastroduodenal artery. Peritoneal dissemination and para-aortic lymph node metastasis were also suspected. EUS-FNA showed neuroendocrine carcinoma with almost 100%positive staining rate of Ki-67. We immediately started etoposide/cisplatin(EP)therapy. After 6 courses of EP, the tumor shrank remarkably and peritoneal disseminations were disappeared. Common hepatic artery and gastroduodenal artery became free from the tumor. However, after 7 courses of EP, CT and PET-CT revealed tumor re-growth. Also renal impairment could not afford to continue EP therapy. Therefore we decided to perform conversion surgery. In the guideline in Japan, there is no content specialized for surgical treatment for NEC. Moreover, second-line of chemotherapy for NEC has not been established. In the future, accumulation of NEC cases will contribute to develop effective multidisciplinary treatment.

[Resection for the Recurrence of Hepatocellular Carcinoma in the Inferior Vena Cava and Right Atrium under Deep Hypothermic Circulatory Arrest].

A 77-year-old man underwent extended right lobectomy of the liver for rupture of hepatocellular carcinoma. Recurrence in the inferior vena cava andright atrium was noted 30 months after surgery. We performedextirpation of this tumor thrombosis under retrograde cerebral perfusion during deep hypothermic circulatory arrest. The pericardium was cut through sternotomy, and cooling was initiated. After cardiac arrest at 20.4°C, the inferior vena cava was separated. An incision was made in the right atrium andthe tumor thrombus was extirpated. In the meantime, brain protection was maintainedby retrograde cerebral perfusion. The patient was discharged on day 12 without postoperative complications. He remains alive 6 months after surgery without recurrence. This procedure prevented pulmonary embolism due to tumor thrombosis release. It was also possible to perform the procedure with retrograde cerebral perfusion.

[A Case of Pancreatic Metastasis from Pulmonary Pleomorphic Carcinoma].

We report a case of pancreatic metastasis of pulmonary pleomorphic carcinoma with duodenal invasion after left lower lobectomy. A 65-year-old male underwent left lower lobectomy for left lung cancer in 2016. The final pathological finding was a diagnosis is of pleomorphic carcinoma, pT2bN0M0, stageⅡA. The patient rejected postoperative chemotherapy for 10 months after lung surgery, and he was admitted to our hospital with poor oral intake. CT revealed that the tumor was located in the 2nd part of the duodenum, was about 7 cm in diameter, and was suspected to invade the superior mesenteric vein (SMV). Gastroendoscopy revealed whole-circumference stenosis at the 2nd part of the duodenum. The biopsy was suspicious of duodenal metastasis from pulmonary pleomorphic carcinoma. We scheduled pancreaticoduodenectomy with reconstruction of the portal vein. Regarding the intraoperative findings, the tumor was palpated at the 2nd part of the duodenum, and the tumor invaded the transverse colon and right urinary duct. The SMV had been invaded from the gastro-colic trunk to the root of the ileocolic vein. Therefore, pancreaticoduodenectomy, reconstruction of the portal vein with replacement of the graft of the left external iliac vein, right hemicolectomy, and right ureteral resection were performed. Regarding the pathological findings, the tumor existed in the pancreatic parenchyma and invaded the duodenal mucosa. The tumor cells were similar to those in a previous pulmonary pleomorphic carcinoma. The final pathological diagnosis was pancreatic metastases from pulmonary pleomorphic carcinoma. Surgical reports of metastatic pancreatic tumor have been observed sporadically; however, those reports were of pancreatic metastasis of renal cancer, and there are few reports of resection of pancreatic metastasis. This is a very valuable case of pancreatic metastasis from pulmonary pleomorphic carcinoma that could be resected.

[Pancreaticoduodenectomy in a Patient with Severe Hyperbilirubinemia - A Case Report].

Although the safety of pancreaticoduodenectomy(PD)with hyperbilirubinemia has been reported, the permissible value of preoperative serum bilirubin is unknown. A 58-year-old man developed obstructive jaundice due to duodenal adenocarcino- ma. The initial serum bilirubin value was 26.8mg/dL, and preoperative biliary drainage was performed. However, the serum bilirubin value only decreased to 17.7mg/dL. The other liver function tests were normal. Therefore, we decided to perform PD despite persistent severe hyperbilirubinemia. The postoperative course was uneventful and the bilirubin value improved. He was discharged 17 days after the operation. In the present case, we safely performed PD despite severe jaundice after adequate preoperative liver function evaluation. The attempt to reduce the bilirubin value before surgery did not appear to affect the postoperative course.

[Strategy for Unresectable Pancreatic Cancer with Stenosis of the Duodenum - A Case Report].

Unresectable(UR)pancreatic cancer often causes duodenal obstruction. Case 1: A 58-year-old man was diagnosed with UR pancreatic cancer with obstruction of the 3rd duodenal portion. A duodenum 2nd portion jejunum bypass was performed, and FOLFIRINOX was introduced and continued over 6 months. Case 2: A 74-year-old man was diagnosed with UR pancreatic cancer with obstruction of the duodenum near the Treitz ligament. A duodenum 3rd portion jejunum bypass was performed, and gemcitabine plus nab-paclitaxel was introduced. After 8 courses of GN, adjuvant surgery was performed. Both patients resumed oral intake within a few days after bypass, their performance statuses(PS)were improved, and their body weights increased. Because a duodenal jejunum bypass is more physiological than a gastro-jejunum bypass and duodenal stent, stable ingestion is enabled, and they are stable enough for early initiation of chemotherapy.

[Primary Prophylactic Administration of Pegfilgrastim in FOLFIRINOX Therapy for Locally Advanced Pancreatic Carcinoma].

FOLFIRINOX therapy has a high response rate for pancreatic carcinoma, but has serious adverse effects. FOLFIRINOX therapy was administered to 11 patients with locally advanced pancreatic carcinoma at our hospital. We investigated the usefulness of primary prophylactic administration of pegfilgrastim(PegG). In the group receiving PegG, as well as with onset of neutropenia and thrombocytopenia, febrile neutropenia was reduced. Rates of anorexia and fatigue were also lower than in those who did not receive PegG. The PegG group maintained a high average relative dose intensity, as well as a high response rate. Primary prophylactic administration of PegG in FOLFIRINOX therapy is valid for pancreatic carcinoma.

A useful model capable of predicting the clearance of cytochrome 3A4 (CYP3A4) substrates in humans: validity of CYP3A4 transgenic mice lacking their own Cyp3a enzymes.

The accurate prediction for the body clearance of a novel drug candidate by humans during the preclinical stage contributes to its successful development. To improve the predictability of human hepatic clearance, we focused on CYP3A4, which is involved in the metabolism of more than 50% of all currently marketed drugs. In this study, we investigated the validity of the in vivo model using transgenic mice carrying the human CYP3A4 gene and lacking their own Cyp3a genes (CYP3A4-Tg mice). The CYP3A4 activity toward its substrates in liver microsomes was similar in CYP3A4-Tg mice and humans. As for the clearance, six CYP3A4 substrates (alprazolam, felodipine, midazolam, nifedipine, nitrendipine, and quinidine) were given intravenously to CYP3A4-Tg mice, and their hepatic intrinsic clearance (CLint,h) was evaluated. A regression analysis of the data obtained indicated that the CLint,h values of six substrates in CYP3A4-Tg mice were highly correlated with those in humans (R(2) = 0.95). This correlation could be improved by correcting the CLint,h values by the relative contribution of artificially expressed CYP3A4 to the overall metabolism in the mice. From these findings, it is reasonable to expect that the CLint,h of a particular drug in humans is predictable by applying the CLint,h obtained in CYP3A4-Tg mice to a regression line prepared in advance. The variance of the CLint,h prediction by this method was evaluated and found to be within a range of 2-fold of the regression value. These results suggest that the CYP3A4-Tg mouse model has the potential to accurately predict the human hepatic clearance of CYP3A4 substrates.

Hemodynamic changes in the hepatic circulation after the modulation of the splenic circulation in an in vivo human experimental model.

Recent advances in liver surgery have highlighted the effects of the splenic circulation on the hepatic circulation with respect to the hepatic arterial buffer response (HABR). The aim of the present study was to investigate the actual hemodynamic effects of splenic artery embolization/ligation and splenectomy on the hepatic circulation in patients who underwent pancreaticoduodenectomy through in vivo experimental models. In vivo models of splenic artery embolization/ligation (only splenic artery clamping) and splenectomy (simultaneous clamping of both the splenic artery and the splenic vein) were created in 40 patients who underwent pancreaticoduodenectomy for various reasons. The portal venous flow velocity, the portal venous flow volume, the hepatic arterial flow velocity, and the hepatic arterial resistance index were measured with color Doppler ultrasonography. Clamping of the splenic artery induced an immediate and significant increase (16%) in the hepatic artery velocity (P < 0.001), and the portal venous flow also decreased significantly (10%, P = 0.03). Fifteen minutes after the clamping of the splenic artery, the hepatic artery velocity remained significantly increased at the level of the initial clamping, and the portal venous flow significantly decreased (16%, P < 0.001). Clamping of the splenic vein, which was performed after the clamping of the splenic artery, resulted in an immediate and significant decrease (30%) in the portal venous flow (P < 0.001), but the hepatic arterial flow was not affected. Fifteen minutes after the clamping of the splenic vein, there was no change in the portal flow, which remained significantly lower (28%) than the flow in controls, whereas the hepatic arterial flow further significantly increased (31%, P < 0.001). In conclusion, our findings indicate that both splenic artery embolization/ligation and splenectomy are effective for increasing hepatic arterial flow and decreasing portal flow, with splenectomy providing a greater advantage. The HABR underlies these hemodynamic changes.

[A case of inflammatory myofibroblastic tumor with repeated recurrence and metastasis].

A 37-year-old woman presented with an asymptomatic pulmonary nodule. A pulmonary S8 segmentectomy was performed. Recurrence and metastasis were noted every 6 months after surgery; repeat surgeries were performed at 18, 24, and 36 months. On histopathological examination, the tumor showed spindle cell proliferation with infiltration of various inflammatory cells, and was diagnosed as inflammatory myofibroblastic tumor (IMT). An IMT is defined as a tumor of intermediate biological potential, which may sometimes metastasize. It is necessary to note the potential for metastasis in the future, especially in cases with anaplastic lymphoma kinase (ALK)-negative immunohistological staining, where the tumor grade can be high.

Selective SGLT2 inhibition by tofogliflozin reduces renal glucose reabsorption under hyperglycemic but not under hypo- or euglycemic conditions in rats.

To understand the risk of hypoglycemia associated with urinary glucose excretion (UGE) induced by sodium-glucose cotransporter (SGLT) inhibitors, it is necessary to know the relationship between the ratio of contribution of SGLT2 vs. SGLT1 to renal glucose reabsorption (RGR) and the glycemic levels in vivo. To examine the contributions of SGLT2 and SGLT1 in normal rats, we compared the RGR inhibition by tofogliflozin, a highly specific SGLT2 inhibitor, and phlorizin, an SGLT1 and SGLT2 (SGLT1/2) inhibitor, at plasma concentrations sufficient to completely inhibit rat SGLT2 (rSGLT2) while inhibiting rSGLT1 to different degrees. Under hyperglycemic conditions by glucose titration, tofogliflozin and phlorizin achieved ≥50% inhibition of RGR. Under hypoglycemic conditions by hyperinsulinemic clamp, RGR was reduced by 20-50% with phlorizin and by 1-5% with tofogliflozin, suggesting the smaller contribution of rSGLT2 to RGR under hypoglycemic conditions than under hyperglycemic conditions. Next, to evaluate the hypoglycemic potentials of SGLT1/2 inhibition, we measured the plasma glucose (PG) and endogenous glucose production (EGP) simultaneously after UGE induction by SGLT inhibitors. Tofogliflozin (400 ng/ml) induced UGE of about 2 mg·kg⁻¹·min⁻¹ and increased EGP by 1-2 mg·kg⁻¹·min⁻¹, resulting in PG in the normal range. Phlorizin (1,333 ng/ml) induced UGE of about 6 mg·kg⁻¹·min⁻¹ and increased EGP by about 4 mg·kg⁻¹·min⁻¹; this was more than with tofogliflozin, but the minimum PG was lower. These results suggest that the contribution of SGLT1 to RGR is greater under lower glycemic conditions than under hyperglycemic conditions and that SGLT2-selective inhibitors pose a lower risk of hypoglycemia than SGLT1/2 inhibitors.

[A case of neuroendocrine small cell carcinoma of the common bile duct].

A 75-year-old woman admitted for jaundice was found to have a tumor occupying the lumen of the middle bile duct on diagnostic imaging. Treatment with endoscopic retrograde bile drainage (ERBD) improved the jaundice. Bile cytology was defined as class III. We diagnosed the condition as middle bile duct cancer with a replaced right hepatic artery, and therefore, curative resection was possible. Pancreatoduodenectomy was performed and the replaced right hepatic artery was resected. Histological examination using hematoxylin and eosin( HE) staining and immunological staining with chromogranin A, synaptophysin, and CD56 revealed small cell carcinoma. Small cell carcinoma of the bile duct is a highly malignant disease. Fortunately, it is rare and only 22 cases have been reported in the Japanese literature.

Quantitative prediction of mechanism-based inhibition caused by mibefradil in rats.

It was previously demonstrated that mibefradil, which shows mechanism-based inhibition in humans, also caused drug-drug interactions (DDIs) with midazolam (MDZ) in rats. In this study, we aimed to quantitatively predict the DDIs observed in rats using a physiologically based pharmacokinetic (PBPK) model from in vitro inactivation parameters. For more precise predictions, contribution ratios of cytochrome P450 (P450) isozymes involved in MDZ metabolism and inactivation parameters of mibefradil against each isozyme were incorporated in the predictive model. The evaluation of metabolic rate using recombinant P450s suggested that CYP3A2 and CYP2C11 contributed to 89 and 11% of MDZ metabolism, respectively. Inactivation studies of mibefradil against the two isozymes showed that the maximal inactivation rate constants (k(inact)) were considerable in both isozymes (0.231-0.565 min(-1)), whereas the inhibitor concentration producing half the k(inact) (K(I, app)) of CYP3A2 (0.263-0.410 µM) was a good deal lower than that for CYP2C11 (6.82-11.4 µM). As a result of predicting the DDIs using the PBPK model, predicted increases in areas under the concentration-time curve of MDZ with coadministration of mibefradil (284 and 510% at 6 and 12 mg/kg mibefradil, respectively) closely corresponded to the observed values (226 and 545%, respectively). From those results, it was thought that the construction of a predictive model for DDIs using the PBPK model in detail would enable us to quantitatively predict in vivo DDIs from in vitro data. This approach to predict DDIs on the basis of the contributing isozymes would be important for predicting clinical DDIs of drugs metabolized by multiple enzymes.

The reconstituted 'humanized liver' in TK-NOG mice is mature and functional.

To overcome the limitations of existing models, we developed a novel experimental in vivo platform for replacing mouse liver with functioning human liver tissue. To do this, a herpes simplex virus type 1 thymidine kinase (HSVtk) transgene was expressed within the liver of highly immunodeficient NOG mice (TK-NOG). Mouse liver cells expressing this transgene were ablated after a brief exposure to a non-toxic dose of ganciclovir (GCV), and transplanted human liver cells are stably maintained within the liver (humanized TK-NOG) without exogenous drug. The reconstituted liver was shown to be a mature and functioning "human organ" that had zonal position-specific enzyme expression and a global gene expression pattern representative of mature human liver; and could generate a human-specific profile of drug metabolism. The 'humanized liver' could be stably maintained in these mice with a high level of synthetic function for a prolonged period (8 months). This novel in vivo system provides an optimized platform for studying human liver physiology, including drug metabolism, toxicology, or liver regeneration.

Model analysis of the concentration-dependent permeability of P-gp substrates.

PURPOSE: Recently, it was reported that the apparent Michaelis-Menten constant (Km(app)) of a P-glycoprotein (P-gp) substrate, defined for the extracellular substrate concentration, increases as the P-gp expression level in the cell increases. By its nature, the Km value should not depend on the level of P-gp expression. The purpose of this study is to establish a model which can estimate the Km value independent of the P-gp expression level in cells. METHODS: The previously reported concentration-dependent permeability of verapamil, quinidine, and vinblastine in MDR1-MDCKII, P-gp-highly induced Caco-2, P-gp-induced Caco-2, normal Caco-2, and MDR1-knockdown Caco-2 cells data were analyzed using a model in which the Km value was defined for the intracellular substrate concentration. RESULTS: The estimated Km values defined for the substrate concentration inside the cells were almost the same among various cells with different levels of P-gp expression. The estimated Vmax values were approximately proportional to the P-gp expression level. CONCLUSION: The established kinetic model was found to be rational based on the results that the Km values of P-gp substrates were about the same for cells expressing various levels of P-gp, while the Vmax values were proportional to the expression levels of P-gp.

Prediction of drug-drug interactions based on time-dependent inhibition from high throughput screening of cytochrome P450 3A4 inhibition.

A method of assessing the risk of drug-drug interaction (DDI) caused by mechanism-based inhibition (MBI) was developed for early-stage drug development using cytochrome P450 (CYP) 3A4 inhibition screening data. CYP3A4 inhibition was evaluated using a fluorescent substrate with or without preincubation containing an inhibitor. The results showed that five well-known mechanism-based inhibitors, but not the competitive inhibitor ketoconazole, had lower IC(50) after preincubation, suggesting the utility of the IC(50) shift by preincubation to discern mechanism-based inhibitors. A method to approximately predict the change in the area under the concentration-time curve (AUC) of a co-administered drug by MBI was found using IC(50) shift data and the unbound mean plasma concentration of the inhibitor. From our predictions of change in the AUC for 38 drugs using this method, all mechanism-based inhibitors causing change in the AUC of more than 200% were predicted to be high risk. In conclusion, our method provides a simple assessment of the risk of DDI from mechanism-based inhibitors, especially in the early stages of drug development.