Ryuta Nishitai

Evaluation of ammonia and lidocaine clearance, and galactose elimination capacity of xenoperfused pig livers using a pharmacokinetic analysis.

BACKGROUND We introduced the pharmacokinetic method into the functional evaluation of xenogeneic extracorporeal liver perfusion as an artificial liver assist device, and examined the influence of xenogeneic humoral injury on the metabolic function of xenoperfused pig livers. METHODS Isolated pig livers were perfused with fresh porcine blood (group 1; n=5) or fresh human blood (group 2; n=5) for 9 hr. Clearance (CL) of ammonia and lidocaine, and galactose elimination capacity (Vmax) were determined at three points during the perfusion using a one-compartment pharmacokinetic model. RESULTS Concentrations of ammonia and lidocaine decreased exponentially and those of galactose decreased linearly after a bolus injection in both groups. A one-compartment model provided satisfactory curve fittings for these test substances. No decreases of ammonia CL, lidocaine CL, or galactose Vmax were observed until 9 hr in either group. No differences were observed between the two groups with respect to these metabolic functions. In group 1, only slight interlobular edema was observed at 9 hr. In group 2, membrane attack complex was diffusely deposited at 3 hr and severe interlobular damage was histologically observed at 9 hr, although hepatocellular damage was minimal even at 9 hr. Alpha glutathione S-transferase and mitochondrial aspartate aminotransferase were comparable between the two groups. CONCLUSIONS Pharmacokinetic analysis allowed the evaluation of ammonia CL, lidocaine CL, and galactose Vmax of the perfused pig livers. Despite xenogeneic humoral injuries, the xenoperfused livers maintained these metabolic functions at the same levels as the alloperfused livers for 9 hr.

Oral and Parenteral Versus Parenteral Antibiotic Prophylaxis in Elective Laparoscopic Colorectal Surgery (JMTO PREV 07-01): A Phase 3, Multicenter, Open-label, Randomized Trial.

Objective:To confirm the efficacy of oral and parenteral antibiotic prophylaxis (ABX) in the elective laparoscopic colorectal surgery. Background:There is no evidence for the establishment of an optimal ABX regimen for laparoscopic colorectal surgery, which has become an important choice for the colorectal cancer patients. Methods:The colorectal cancer patients scheduled to undergo laparoscopic surgery were eligible for this multicenter, open-label, randomized trial. They were randomized to receive either oral and parenteral prophylaxis (1 g cefmetazole before and every 3 h during the surgery plus 1 g oral kanamycin and 750 mg metronidazole twice on the day before the surgery; Oral-IV group) or parenteral prophylaxis alone (the same IV regimen; IV group). The primary endpoint was the incidence of surgical site infections (SSIs). Secondary endpoints were the incidence rates of Clostridium difficile colitis, other infections, and postoperative noninfectious complications, as well as the frequency of isolating specific organisms. Results:Between November 2007 and December 2012, 579 patients (289 in the Oral-IV group and 290 in IV group) were evaluated for this study. The incidence of SSIs was 7.26% (21/289) in the Oral-IV group and 12.8% (37/290) in the IV group with an odds ratio of 0.536 (95% CI, 0.305–0.940; P = 0.028). The 2 groups had similar incidence rates of C difficile colitis (1/289 vs 3/290), other infections (6/289 vs 5/290), and postoperative noninfectious complications (11/289 vs 12/290). Conclusions:Our oral-parenteral ABX regimen significantly reduced the risk of SSIs following elective laparoscopic colorectal surgery.

Toward Development and Production of Human T Cells in Swine for Potential Use in Adoptive T Cell Immunotherapy

Immunotherapy and vaccination for cancer or infection are generally approached by administration of antigen or stimulation of antigen-presenting cells or both. These measures may fail if the treated individual lacks T cells specific for the immunogen(s). We tested another strategy-the generation of new T cells from hematopoietic stem cells that might be used for adoptive immunotherapy. To test this concept, we introduced T cell-depleted human bone marrow cells into fetal swine and tested the swine for human T cells at various times after birth. Human T cells were detected in the thymus and blood of the treated swine. These cells were generated de novo as they contained human T cell receptor excision circles not present in the T cell-depleted bone marrow. The human T cells were highly diverse and included novel specificities capable of responding to antigen presented by human antigen-presenting cells. Our findings constitute a first step in a new promising approach to immunotherapy in which tumor- or virus-specific T cell clones lacking in an individual might be generated in a surrogate host from hematopoietic stem cells of the individual to be treated.

Suppressed complement activation in human decay accelerating factor transgenic porcine liver cross-circulated with nonhuman primates.

Background. We developed an extracorporeal liver perfusion (ECLP) system as a liver-assist device. In this study, we evaluated the safety of the ECLP using human decay accelerating factor (hDAF) transgenic porcine livers in healthy baboons. Methods. Livers were isolated from five hDAF transgenic pigs and five nontransgenic pigs for the ECLP. Ten cross-circulations between the ECLP and healthy baboons were performed without immunosuppressive agents. Cross-circulation was discontinued in any of the following circumstances: elevated hepatic arterial (>200 mm Hg) or portal (>60 mm Hg) perfusion pressure, massive exudate from the graft liver, mild macroscopic hemolysis, thrombocytopenia, or 24-hr well-conditioned cross-circulation. Results. The cross-circulations with nontransgenic porcine livers were discontinued at 4.4±1.2 hr (mean±standard deviation) because of high perfusion pressure (n=2) or hemolysis (n=3). Three cross-circulations with hDAF transgenic porcine livers were performed for 24 hr; the other two cross-circulations were discontinued at 13 and 17 hr because of massive exudate and thrombocytopenia, respectively. The duration was 20.4±5.1 hr. Deposition of membrane attack complex in the hDAF transgenic porcine liver was less than that in the nontransgenic liver, although immunoglobulin-M deposition was comparable. The porcine livers showed no apparent interlobular bleeding or lobular necrosis. All porcine livers maintained bile production during the cross-circulation. No baboons showed any serious complications after the cross-circulation. Conclusion. The hDAF transgenic porcine liver reduced complement activation in xenoperfusion with healthy nonhuman primate blood and led to extended duration of cross-circulation.

The protective role of Kupffer cells in humoral injury of xenoperfused rat livers

BACKGROUND The role of Kupffer cells in a hepatic xenograft rejection is still unclear. We investigated the effect of blocking Kupffer cells on xenogeneic humoral injury using rat livers as the xenoperfusion models. METHODS Rat livers were perfused with fresh human blood after pretreatment either with normal saline (group 1; n = 8) or with gadolinium chloride (GdCl3) solution (group 2; n = 8). Tissue injury was evaluated by alanine aminotransferase release and histological examination. Tumor necrosis factor-alpha (TNF-alpha) production from rat livers was measured by enzyme-linked immunosorbent assay and also examined by immunohistochemistry. In addition, Kupffer cells were isolated after pretreatment either with normal saline or with GdCl3 solution and incubated with human serum. Localization of human C3 and IgM was examined by immunofluorescence. RESULTS Alanine aminotransferase release in group 2 was significantly higher than in group 1 (P = 0.015). Histological examination revealed more severe tissue injury in group 2. The mean TNF-alpha level was not significantly different between the two groups. In immunohistochemistry, TNF-alpha was positive primarily on vascular endothelial cells in both groups. Immunofluorescence of saline-treated Kupffer cells showed an uptake of human C3 in the cytoplasm, whereas no uptake was observed in GdCl3-treated cells. The uptake of human IgM did not differ between the two groups. CONCLUSIONS These results suggest that Kupffer cells have a protective role in preventing xenogeneic humoral injury. Their ability to absorb xenogeneic complements may contribute to this protective mechanism.

Indication for neoadjuvant chemotherapy in patients with colorectal liver metastases based on a nomogram that predicts disease-free survival

The purpose of this study was to validate the Beppu nomogram, which predicts disease‐free survival (DFS) after resection of colorectal liver metastases, and to investigate the efficacy of neoadjuvant chemotherapy based on the nomogram‐predicted recurrence risk.

Prospective registry for laparoscopic liver resection

Laparoscopic liver resection (LLR) has been widely performed throughout the world. Although prospective registry studies to clarify the safety of LLR have been feasible, no prior multicenter prospective study has addressed this issue. We have conducted a multicenter prospective cohort study to reveal the current status of LLR in Japan.

Metastatic colorectal cancer responsive to regorafenib for 2 years: a case report

BackgroundRegorafenib is an oral multikinase inhibitor that has been demonstrated as clinically effective in patients with metastatic colorectal cancer in phase III studies. Although disease control was achieved in 40% of the pretreated patients with metastatic colorectal cancer in the pivotal studies, radiological response has rarely been reported. Severe adverse events associated with regorafenib are known to occur during the first and second courses of treatment. We present a case of a 62-year-old Japanese patient whose metastatic colorectal cancer has been responding to treatment with regorafenib for 2 years.Case presentationA 54-year-old Japanese man visited our institute exhibiting general malaise, and he was diagnosed with ascending colon cancer in April 2006. He underwent right hemicolectomy, and the final staging was T3N0M0, stage II. After 19 months, pulmonary metastasis and anastomotic recurrences were detected, and a series of operations were performed to resect both metastatic lesions. After that, liver metastasis, a duodenal metastasis with right renal invasion, right adrenal metastasis, and para-aortic lymph node metastases were observed during follow-up, and chemotherapy and resection were performed. The patient had metastatic para-aortic lymph nodes after the fifth tumor resection and underwent multiple lines of chemotherapy in April 2014. Regorafenib monotherapy was started at 80 mg/day. Then, regorafenib was increased to 120 mg/day in the second cycle. Regorafenib monotherapy led to 60% tumor shrinkage within the initial 2 months, and the tumor further decreased in size over 4 months until it became unrecognizable on imaging studies. The clinical effects of regorafenib monotherapy have shown a partial response according to Response Evaluation Criteria in Solid Tumors criteria. No severe adverse events were observed, except for mild fatigue and hand-foot syndrome. The patient has received 24 courses of regorafenib over 2 years without exhibiting tumor progression.ConclusionsTo the best of our knowledge, this is the longest treatment with regorafenib without tumor progression ever reported. A reduced dosage of regorafenib at induction may ameliorate the cutaneous and hepatic toxicity associated with its use.

Portal vein branching order helps in the recognition of anomalous right-sided round ligament: common features and variations in portal vein anatomy

PurposeThis study aimed to evaluate the common features and variations of portal vein anatomy in right-sided round ligament (RSRL), which can help propose a method to detect and diagnose this anomaly.MethodsIn this retrospective study of 14 patients with RSRL, the branching order of the portal tree was analyzed, with special focus on the relationship between the dorsal branch of the right anterior segmental portal vein (PA–D) and the lateral segmental portal vein (PLL), to determine the common features. The configuration of the portal vein from the main portal trunk to the right umbilical portion (RUP), the inclination of the RUP, and the number and thickness of the ramifications branching from the right anterior segmental portal vein (PA) were evaluated for variations.ResultsIn all subjects, the diverging point of the PA–D was constantly distal to that of the PLL. The portal vein configuration was I- and Z-shaped in nine and five subjects, respectively. The RUP was tilted to the right in all subjects. In Z-shaped subjects, the portal trunk between the branching point of the right posterior segmental portal vein and that of the PLL was tilted to the left in one subject and was almost parallel to the vertical plane in four subjects. Multiple ramifications were radially distributed from the PA in eight subjects, whereas one predominant PA–D branched from the PA in six subjects.ConclusionsBased on the diverging points of the PA–D and PLL, we proposed a three-step method for the detection and diagnosis of RSRL.