An alternative splice isoform of mouse CDK5RAP2 induced cytoplasmic microtubule nucleation.

The centrosome lacks microtubule (MT)-nucleation activity in differentiated neurons. We have previously demonstrated that MTs were nucleated at the cytoplasm of mouse neurons. They are supposed to serve seeds for MTs required for dendrite growth. However, the factors that activate the cytoplasmic γ-tubulin ring complex (γTuRC) are unknown. Here we report an alternative splicing isoform of cyclin-dependent kinase 5 regulatory subunit-associated protein 2 (CKD5RAP2) as a candidate for the cytoplasmic γTuRC activator. This isoform lacked exon 17 and was expressed predominantly in the brain and testis. The expression was transient during the development of cortical neurons, which period coincided with the period we reported cytoplasmic MT nucleation. This isoform resulted in a frameshift and generated truncated protein without a centrosomal localization signal. When this isoform was expressed in cells, it localized diffusely in the cytoplasm. It was co-immunoprecipitated with γ-tubulin and MOZART2, suggesting that it can activate cytosolic γTuRCs. After cold-nocodazole depolymerization of MTs and subsequent washout, we observed numerous short MTs in the cytoplasm of cells transfected with the cDNA of this isoform. The isoform-overexpressing cells exhibited an increased amount of MTs and a decreased ratio of acetylated tubulin, suggesting that MT generation and turnover were enhanced by the isoform. Our data suggest the possibility that alternative splicing of CDK5RAP2 induces cytoplasmic nucleation of MTs in developing neurons.

Functional changes in cytotoxic CD8+ T-cell cross-reactivity against the SARS-CoV-2 Omicron variant after mRNA vaccination.

Understanding the T-cell responses involved in inhibiting COVID-19 severity is crucial for developing new therapeutic and vaccine strategies. Here, we characterized SARS-CoV-2 spike-specific CD8+ T cells in vaccinees longitudinally. The BNT162b2 mRNA vaccine can induce spike-specific CD8+ T cells cross-reacting to BA.1, whereas the T-cell receptor (TCR) repertoire usages decreased with time. Furthermore the mRNA vaccine induced spike-specific CD8+ T cells subpopulation expressing Granzyme A (GZMA), Granzyme B (GZMB) and Perforin simultaneously in healthy donors at 4 weeks after the second vaccination. The induced subpopulation was not maintained at 12 weeks after the second vaccination. Incorporating factors that efficiently induce CD8+ T cells with highly cytotoxic activity could improve future vaccine efficacy against such variants.

Isolation and Characterization of Tissue Resident CD29-Positive Progenitor Cells in Livestock to Generate a Three-Dimensional Meat Bud.

The current process of meat production using livestock has significant effects on the global environment, including high emissions of greenhouse gases. In recent years, cultured meat has attracted attention as a way to acquire animal proteins. However, the lack of markers that isolate proliferating cells from bovine tissues and the complex structure of the meat make it difficult to culture meat in a dish. In this study, we screened 246 cell-surface antibodies by fluorescence-activated cell sorting for their capacity to form colonies and their suitability to construct spheroid "meat buds". CD29+ cells (Ha2/5 clone) have a high potency to form colonies and efficiently proliferate on fibronectin-coated dishes. Furthermore, the meat buds created from CD29+ cells could differentiate into muscle and adipose cells in a three-dimensional structure. The meat buds embedded in the collagen gel proliferated in the matrix and formed large aggregates. Approximately 10 trillion cells can theoretically be obtained from 100 g of bovine tissue by culturing and amplifying them using these methods. The CD29+ cell characteristics of bovine tissue provide insights into the production of meat alternatives in vitro.

Role of cAMP in phenotypic changes of osteoblasts.

Bone remodeling is precisely controlled by bone formation and bone resorption, and osteoblasts are responsible for both processes. Osteoblasts exhibit an osteoclastogenic phenotype in response to elevated intracellular cyclic AMP [cAMP]i levels. However, the role of cAMP in osteoblasts acquiring an osteogenic phenotype is controversial. To elucidate the effect of cAMP on both phenotypes, an osteoblast-like cell line, TMS-12, was established in our laboratory and used in this study. Dibutyryl-cAMP (dBcAMP), a cAMP analogue, inhibited mineralization in TMS-12 cells and MC3T3E1 cells (an osteoblast-like cell line) but promoted osteoclast-supporting activity in TMS-12 cells. Moreover, mineralization was inhibited in glucagon receptor-transduced TMS-12 cells (TMS-12GCGR) after glucagon treatment to increase endogenous [cAMP]i levels. However, the osteoclast-supporting activity of TMS-12GCGR cells was stimulated by glucagon treatment. These cAMP-induced phenotypic changes of osteoblasts were also supported by their gene expression profile. These results suggest that [cAMP]i is an important factor mediating phenotypic changes of osteoblasts. Our findings may provide valuable insights into the mechanisms that underlie bone remodeling in both, healthy and diseased states.

[Primary adenosquamous carcinoma of the liver presenting with hematochezia due to tumor invasion of the colon].

A 69-year-old female was referred to our hospital with hematochezia. Dynamic computed tomography demonstrated a large tumor with rim enhancement and central necrosis that invaded into the transverse colon. The tumor was resected, and histopathological examination revealed mixed adenocarcinoma and squamous cell carcinoma with partial abscess formation. On the basis of a literature review and the findings from the present case, rim enhancement with central necrosis on imaging appears to be characteristic of this disease.

The vessel sealing system (LigaSure) in hepatic resection: a randomized controlled trial.

OBJECTIVE: The aim of this trial was to verify the new surgical device (the LigaSure vessels sealing system) decrease liver transection time. SUMMARY BACKGROUND DATA: Among the major goals in hepatic resection are minimization of the operation time and of the blood loss. Preliminary reports have suggested that the vessel sealing system might decrease the liver transection time, which is directly associated with the amount of blood loss. METHODS: Patients who were scheduled to undergo hepatic resection at the Tokyo University Hospital were assigned, by the minimization method, to either use of the new vessel sealing system (VS group) or the conventional clamp crushing method (CC group) for liver transection. The primary end point was the liver transection time, and the secondary endpoints were the amount of blood loss during the entire operation and during liver transection, length of hospital stay, postoperative liver function, and the incidence of various adverse events. An English-language summary of the protocol was submitted (registration ID: C000000337) to the Clinical Trials Registry managed by the University Hospital Medical Information Network in Japan, which can be accessed commission-free on the internet (Available at: http://www.umin.ac.jp/ctr/index.htm). RESULTS: From February to December in 2006, a total of 165 patients underwent liver resection for some benign or malignant disease of the liver. Among these patients, 120 were randomly assigned to the CC (n = 60) or the VS (n = 60) group. There was no mortality in either of the 2 groups. The median liver transection time in the VS group was 57 minutes (range: 11-127), similar to that in the CC group (56 [range: 9-269] min, P = 0.64), while there was no difference in the transection speed between the 2 groups (1.16 [0.15-2.26] cm/min vs. 1.10 [0.15-2.66] cm/min, P = 0.95). The amount of blood loss and blood loss per transection area during liver transaction in the VS group was also similar to that in the CC group (median: 315 [25-2415] mL vs. 315 [10-1700] mL; P = 0.80) and (5.04 [1.01-44.2] mL/cm vs. 4.36 [0.15-50.5] mL/cm; P = 0.14), respectively. CONCLUSIONS: This randomized controlled trial showed that while the vessel sealing system was safe, its use was not associated with any significant decrease of the operation time or blood loss during liver transaction as compared with that of the clamp crushing method.

Adult intussusception induced by the stump of the jejunal loop after liver transplantation.

Intussusception occurs rarely in adults compared with children, and in the case of adults, some organic disease, such as a benign or malignant tumor, can be found at the leading edge of the intussusception in about 90% of adult cases. This study reports a case of adult intussusception in which the stump of the jejunal loop in a Roux-en-Y bilioenteric reconstruction acted as a leading tip of the intussusception.

Two-stage pancreatojejunostomy in pancreaticoduodenectomy: a retrospective analysis of short-term results.

BACKGROUND: The morbidity associated with pancreatic fistula formation after pancreaticoduodenectomy (PD) still remains high. While theoretically 2-stage pancreatojejunostomy (PJ) is effective for preventing pancreatic juice enzymes from becoming activated by enteric contents, its clinical usefulness remains unknown. The aim of this retrospective study was to evaluate the short-term results of two-stage PJ in PD. PATIENTS AND METHODS: In PD cases with a narrow main pancreatic duct and/or soft texture of the pancreas, we performed 2-stage PJ; first an external tube pancreatostomy was performed, in which the tube was not passed through the jejunal loop, followed about 3 months later by second-stage reconstruction for PJ. Between 1998 and 2005, PDs with 1-stage and 2-stage PJ were performed in 53 and 99 patients, respectively, at our institution. Among the latter 99 patients, 13 (13%) also underwent concomitant right or extended right hemi-hepatectomy. In this study, the clinical records of these 152 patients were retrospectively analyzed. RESULTS: After PD, a pancreatic fistula occurred in 58% of the patients undergoing 2-stage PJ; however, the fistula healed with conservative therapy in all but 2 patients who required surgical drainage for abdominal abscess. A second-stage pancreato-enteric reconstruction by PJ could be completed about 3 months after the PD in 89 of the 99 (90%) cases. Although the incidence of pancreatic fistula was 16% after the second-stage reconstruction for PJ, completion pancreatectomy was not needed in any of the cases. There were no deaths or other catastrophic events related to the procedure. CONCLUSIONS: While it is difficult to completely prevent pancreatic fistula formation after PD, a 2-stage PJ appears to be effective for minimizing pancreatic juice-related adverse events, especially in high-risk patients with a narrow pancreatic duct or undergoing highly invasive surgery, such as hepato-pancreticoduodenectomy.

Transhepatic approach for a small paracaval tumor in repeat resection.

To resect a small liver tumor located in the paracaval portion, we adopted transhepatic enucleation, i.e. enucleation of the tumor from the transected plane along the main portal fissure. In contrast to caudate lobectomy, this procedure can save dissection around the liver and vena cava, which would increase operation time and blood loss especially in repeat surgery after removal of Couinaud's segment VII or the right lateral sector. It can also minimize the liver parenchymal volume to be resected. The transhepatic enucleation would be a safe and recommendable surgical technique for a small paracaval tumor in repeat resection and/or in patients with poor liver functional reserve.

Living donor liver transplantation for epithelioid hemangioendothelioma: Report of a case.

Epithelioid hemangioendothelioma (EH) of the liver is a rare tumor, generally considered to have low-grade malignancy. Little is known about its clinical behavior and the therapeutic strategy is not established. We report the case of a 36-year-old woman who underwent living donor liver transplantation for EH with splenic metastases and died of recurrence 8 months later. To determine if transplantation improves the prognosis of patients with EH, we must re-evaluate its indications.

Extent of hepatectomy on splenic hypertrophy and platelet count in live liver donors.

The extent of donor hepatectomy may affect splenic hypertrophy and platelet count. The subjects were 50 live liver donors. The ratio of the graft weight to total liver volume (GW/TLV) and the splenic hypertrophy ratio, expressed as the splenic volume one month after surgery divided by that before surgery, were calculated. The platelet count one month after surgery was divided by that before surgery to determine the rate of the platelet count decrease. The correlation of GW/TLV to the splenic hypertrophy ratio and the rate of the platelet count decrease were examined. The median (range) GW/TLV was 54 (28-71)%. The splenic hypertrophy ratio and the rate of the platelet count decrease was 133 (99-191)% and 92 (71-129)%, respectively. GW/TLV positively correlated with the splenic hypertrophy ratio (Spearman's correlation coefficient (r(s)) = 0.448, p = 0.001), and negatively correlated with the rate of the platelet count decrease (r(s) = -0.471, p < 0.001). Multivariate analysis revealed that GW/TLV influenced the splenic hypertrophy ratio [adjusted odds ratio (OR), 12.0; 95% confidence interval (CI), 1.32-9.04; p = 0.01] and the ratio of the platelet count decrease (adjusted OR, 11.6; 95% CI, 1.40-8.33; p = 0.01). Larger graft procurement might place living liver donors at higher risk for post-operative thrombocytopenia.

Pancreaticoduodenectomy after esophageal and gastric surgery preserving right gastroepiploic vessels.

Secondary pancreaticoduodenectomy was performed in 2 patients, 1 who had undergone proximal gastrectomy for a gastric carcinoma and 1 who had undergone subtotal esophagectomy with stomach tube reconstruction for an inferior thoracic esophageal carcinoma. To prevent ischemia and congestion of the remnant stomach, the inflow and outflow pathways to the stomach, such as the right gastroepiploic artery and vein, were preserved. In this article, we describe the preservation procedures and discuss the problems of the secondary abdominal surgical procedure.

Living donor liver transplantation for primary biliary cirrhosis: retrospective analysis of 50 patients in a single center.

Summary Although living donor liver transplantation (LDLT) is accepted as an alternative therapy for primary biliary cirrhosis (PBC), the postoperative results are not well known. Fifty patients with PBC underwent LDLT at Tokyo University Hospital. Their clinical records were retrospectively analyzed. Postoperative death occurred in four patients within 2 months (mortality, 8%), while later death occurred in three patients. In the median follow-up period of 35 months (range 4-84 months), the 1, 3, and 5-year overall survival rates were 90%, 88%, and 80%, respectively. The laboratory data indicated that graft function was sufficient. No recurrence of PBC was confirmed. Multivariate analysis indicated that an updated Mayo score of <10 was a significantly favorable factor for short hospitalization (hazard ratio, 9.52; 95% confidence interval, 1.14-79.5; P = 0.03). In conclusion, LDLT provides a satisfactory long-term survival with the PBC patients.

Hepato-pancreaticoduodenectomy with preservation of the collateral arterial arcade in the head of the pancreas in a patient with celiac axis stenosis.

Hepato-pancreaticoduodenectomy was performed for common bile duct carcinoma associated with celiac axis stenosis. To secure arterial blood flow to the upper abdominal organs, we preserved the anterior arcade in the pancreas head acting as a collateral pathway between the superior mesenteric artery and the celiac artery. This is another valid alternative procedure for pancreaticoduodenectomy in a patient with celiac axis stenosis.

Reconstruction of small bile ducts using a parachute technique.

Benign or malignant stricture of extrahepatic bile ducts may result when small intrahepatic bile ducts are anastomosed to the jejunal loop after resection of extrahepatic bile ducts, hepatic parenchyma, and intrahepatic bile ducts. We applied a parachute technique, which has been used for fine vascular anastomosis, to hepaticojejunostomy in eight patients with either extrahepatic bile duct carcinoma or intrahepatic cholangiocellular carcinoma. One to four small bile ducts were anastomosed to the jejunal loop. No patient experienced a complication due to this anastomosis. Postoperative elevation of the serum bilirubin was transient, and all patients were discharged within 36 days after surgery. Although the follow-up period in this series is not yet long enough to evaluate the long-term outcome of this technique, the ease of the hepaticojejunostomy and good short-term results warrant farther clinical investigation of this technique.