Surgical outcome of pancreatic cancer using radical antegrade modular pancreatosplenectomy procedure

AIM:To evaluate the surgical outcomes following radical antegrade modular pancreatosplenectomy (RAMPS) for pancreatic cancer. METHODS:Twenty-four patients underwent RAMPS with curative intent between January 2005 and June 2009 at the National Cancer Center, South Korea. Clinicopathologic data, including age, sex, operative findings, pathologic results, adjuvant therapy, postop-erative clinical course and follow-up data were retro-spectively collected and analyzed for this study. RESULTS:Twenty-one patients (87.5%) underwent distal pancreatectomy and 3 patients (12.5%) underwent total pancreatectomy using RAMPS. Nine patients (37.5%) underwent combined vessel resection, including 8 superior mesenteric-portal vein resections and 1 celiac axis resection. Two patients (8.3%) underwent combined resection of other organs, including the colon, stomach or duodenum. Negative tangential margins were achieved in 22 patients (91.7%). The mean tumor diameter for all patients was 4.09 ± 2.15 cm. The 2 patients with positive margins had a mean diameter of 7.25 cm. The mean number of retrieved lymph nodes was 20.92 ± 11.24 and the node positivity rate was 70.8%. The median survival of the 24 patients was 18.23 ± 6.02 mo. Patients with negative margins had a median survival of 21.80 ± 5.30 mo and those with positive margins had a median survival of 6.47 mo (P = 0.021). Nine patients (37.5%) had postoperative complications, but there were no postoperative mortalities. Pancreatic fistula occurred in 4 patients (16.7%):2 patients had a grade A fistula and 2 had a grade B fistula. On univariate analysis, histologic grade, positive tangential margin, pancreatic fistula and adjuvant therapy were significant prognostic factors for survival. CONCLUSION:RAMPS is a feasible procedure for achieving negative tangential margins in patients with carcinoma of the body and tail of the pancreas.

Single-cell RNA sequencing of mitoticarrested prospermatogonia with DAZL::GFP chickens and revealing unique epigenetic reprogramming of chickens

Background:Germ cell mitotic arrest is conserved in many vertebrates,including birds,although the time of entry or exit into quiescence phase differs.Mitotic arrest is essential for the normal differentiation of male germ cells into spermatogonia and accompanies epigenetic reprogramming and meiosis inhibition from embryonic development to post-hatch.However,mitotic arrest was not well studied in chickens because of the difficulty in obtaining pure germ cells from relevant developmental stage.Results:We performed single-cell RNA sequencing to investigate transcriptional dynamics of male germ cells during mitotic arrest in DAZL::GFP chickens.Using differentially expressed gene analysis and K-means clustering to analyze cells at different developmental stages(E12,E16,and hatch),we found that metabolic and signaling pathways were regulated,and that the epigenome was reprogrammed during mitotic arrest.In particular,we found that histone H3K9 and H3K14 acetylation(by HDAC2)and DNA demethylation(by DNMT3B and HELLS)led to a transcriptionally permissive chromatin state.Furthermore,we found that global DNA demethylation occurred gradually after the onset of mitotic arrest,indicating that the epigenetic-reprogramming schedule of the chicken genome differs from that of the mammalian genome.DNA hypomethylation persisted after hatching,and methylation was slowly re-established 3 weeks later.Conclusions:We found a unique epigenetic-reprogramming schedule of mitotic-arrested chicken prospermatogonia and prolonged hypomethylation after hatching.This will provide a foundation for understanding the process of germ-cell epigenetic regulation in several species for which this process is not clearly described.Our findings on the biological processes related to sex-specific differentiation of prospermatogonia could help studying germline development in vitro more elaborately.

Role of adjuvant chemoradiotherapy and chemotherapy in patients with resected gallbladder carcinoma: a multiinstitutional analysis (KROG 19-04)

Objective:The effectiveness of adjuvant treatments for resected gallbladder carcinoma(GBC)has remained unclear due to lack of randomized controlled trials;thus,the aim of present study was to evaluate the role of adjuvant treatments,including chemoradiotherapy(CRT)and/or chemotherapy(CTx),in patients with resected GBC.Methods:A total of 733 GBC patients who received curative-intent surgical resection were identified in a multi-institutional database.Of 733 patients,372(50.8%)did not receive adjuvant treatment,whereas 215(29.3%)and 146(19.9%)received adjuvant CTx and CRT,respectively.The locoregional recurrence-free survival(LRFS),recurrence-free survival(RFS),and overall survival(OS)of the adjuvant treatment groups were compared according to tumor stage(stage II vs.stage III–IV).Results:In stage II disease(n=381),the 5-year LRFS,RFS,and OS were not significantly different among the no-adjuvant therapy,CTx,and CRT groups,and positive resection margin,presence of perineural invasion,and Nx classification were consistently associated with worse LRFS,RFS,and OS in the multivariate analysis(P<0.05).For stage III–IV(n=352),the CRT group had significantly higher 5-year LRFS,RFS,and OS than the no-adjuvant therapy and CTx groups(67.8%,45.2%,and 56.9%;37.9%,28.8%,and 35.4%;and 45.0%,30.0%,and 45.7%,respectively)(P<0.05).Conclusions:CRT has value as adjuvant treatment for resected GBC with stage III–IV disease.Further study is needed for stage II disease with high-risk features.

ANISOTROPY OF ELASTIC PROPERTIES AND CENTRAL PEAK BEHAVIORS OF UNIAXIAL STRONTIUM BARIUM NIOBATE RELAXOR SINGLE CRYSTALS

The elastic properties of strontium barium niobate single crystals with different strontium content were investigated.The elastic constant and the related hypersonic attenuation showed substantially different values depending on the propagating direction of acoustic waves.This elastic anisotropy was explained based on the uniaxial nature of the order parameter and the diffuse ferroelectric phase transition in this tetragonal system.This observation was correlated with the appearance of strongly polarized central peaks,which reffects strong polarization fluctuations along the uniaxial polar direction.