Efficient Genome Editing in Apple Using a CRISPR/Cas9 system

Genome editing is a powerful technique for genome modification in molecular research and crop breeding, and has the great advantage of imparting novel desired traits to genetic resources. However, the genome editing of fruit tree plantlets remains to be established. In this study, we describe induction of a targeted gene mutation in the endogenous apple phytoene desaturase (PDS) gene using the CRISPR/Cas9 system. Four guide RNAs (gRNAs) were designed and stably transformed with Cas9 separately in apple. Clear and partial albino phenotypes were observed in 31.8% of regenerated plantlets for one gRNA, and bi-allelic mutations in apple PDS were confirmed by DNA sequencing. In addition, an 18-bp gRNA also induced a targeted mutation. These CRIPSR/Cas9 induced-mutations in the apple genome suggest activation of the NHEJ pathway, but with some involvement also of the HR pathway. Our results demonstrate that genome editing can be practically applied to modify the apple genome

Efficacy of prophylactic clip closure in reducing the risk of delayed bleeding after colorectal endoscopic submucosal dissection in patients on anticoagulant therapy: Multicenter prospective study

Ogiyama H., Kato M., Yamaguchi S., et al. Efficacy of prophylactic clip closure in reducing the risk of delayed bleeding after colorectal endoscopic submucosal dissection in patients on anticoagulant therapy: Multicenter prospective study. Digestive Endoscopy , (2024); https://doi.org/10.1111/den.14761.Objectives: The high rate of delayed bleeding after colorectal endoscopic submucosal dissection (ESD) in patients undergoing anticoagulant therapy remains a problem. Whether prophylactic clip closure reduces the rate of delayed bleeding in these patients is unclear. This study aimed to evaluate the efficacy of prophylactic clip closure in patients receiving anticoagulants. Methods: This multicenter prospective interventional trial was conducted at nine referral centers in Japan. Patients regularly taking anticoagulants, including warfarin potassium or direct oral anticoagulants, and undergoing ESD for colorectal neoplasms were enrolled. The discontinuation of anticoagulants was minimized according to recent guidelines. After the ESD, post-ESD ulcers were prophylactically closed using endoclips. The primary end-point was the incidence of delayed bleeding. The sample size was 45 lesions, and prophylactic clip closure was considered effective when the upper limit of the 90% confidence interval (CI) for delayed bleeding did not exceed 20%. Results: Forty-five lesions were used, and three were excluded. Complete closure was achieved in 41/42 lesions (97.6%). The overall delayed bleeding rate was low, at 4.9% (2/41; 90% [CI] 0.8–14.5), which was significantly lower than that at the prespecified threshold of 20% (P = 0.007). The median closure procedure time was 17 min, and the median number of clips was nine. No massive delayed bleeding requiring transfusion, interventional radiology, or surgery was observed, and no thromboembolic events were observed. Conclusion: Prophylactic clip closure may reduce the risk of delayed bleeding following colorectal ESD in patients receiving anticoagulants. Trial registration: UMIN Clinical Trial Registry (UMIN000036734)

Distinct Roles of α7 nAChRs in Antigen-Presenting Cells and CD4+ T Cells in the Regulation of T Cell Differentiation

It is now apparent that immune cells express a functional cholinergic system and that α7 nicotinic acetylcholine receptors (α7 nAChRs) are involved in regulating T cell differentiation and the synthesis of antigen-specific antibodies and proinflammatory cytokines. Here, we investigated the specific function α7 nAChRs on T cells and antigen presenting cells (APCs) by testing the effect of GTS-21, a selective α7 nAChR agonist, on differentiation of CD4+ T cells from ovalbumin (OVA)-specific TCR transgenic DO11.10 mice activated with OVA or OVA peptide323−339 (OVAp). GTS-21 suppressed OVA-induced antigen processing-dependent development of CD4+ regulatory T cells (Tregs) and effector T cells (Th1, Th2, and Th17). By contrast, GTS-21 up-regulated OVAp-induced antigen processing-independent development of CD4+ Tregs and effector T cells. GTS-21 also suppressed production of IL-2, IFN-γ, IL-4, IL-17, and IL-6 during OVA-induced activation but, with the exception IL-2, enhanced their production during OVAp-induced activation. In addition, during antigen-nonspecific, APC-independent anti-CD3/CD28 antibody-induced CD4+ polyclonal T cell activation in the presence of respective polarizing cytokines, GTS-21 promoted development of all lineages, which indicates that GTS-21 also acts via α7 nAChRs on T cells. These results suggest 1) that α7 nAChRs on APCs suppress CD4+ T cell activation by interfering with antigen presentation through inhibition of antigen processing; 2) that α7 nAChRs on CD4+ T cells up-regulate development of Tregs and effector T cells; and that α7 nAChR agonists and antagonists could be potentially useful agents for immune response modulation and enhancement

A machine learning model for predicting the lymph node metastasis of early gastric cancer not meeting the endoscopic curability criteria

The version of record of this article, first published in Gastric Cancer, is available online at Publisher’s website: https://doi.org/10.1007/s10120-024-01511-8.Background: We developed a machine learning (ML) model to predict the risk of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) who did not meet the existing Japanese endoscopic curability criteria and compared its performance with that of the most common clinical risk scoring system, the eCura system. Methods: We used data from 4,042 consecutive patients with EGC from 21 institutions who underwent endoscopic submucosal dissection (ESD) and/or surgery between 2010 and 2021. All resected EGCs were histologically confirmed not to satisfy the current Japanese endoscopic curability criteria. Of all patients, 3,506 constituted the training cohort to develop the neural network-based ML model, and 536 constituted the validation cohort. The performance of our ML model, as measured by the area under the receiver operating characteristic curve (AUC), was compared with that of the eCura system in the validation cohort. Results: LNM rates were 14% (503/3,506) and 7% (39/536) in the training and validation cohorts, respectively. The ML model identified patients with LNM with an AUC of 0.83 (95% confidence interval, 0.76–0.89) in the validation cohort, while the eCura system identified patients with LNM with an AUC of 0.77 (95% confidence interval, 0.70–0.85) (P = 0.006, DeLong’s test). Conclusions: Our ML model performed better than the eCura system for predicting LNM risk in patients with EGC who did not meet the existing Japanese endoscopic curability criteria. Mini-abstract: We developed a neural network-based machine learning model that predicts the risk of lymph node metastasis in patients with early gastric cancer who did not meet the endoscopic curability criteria

Online chemical adsorption studies of Hg, Tl, and Pb on SiO2 and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA

Online gas-solid adsorption studies with single-atom quantities of Hg, Tl, and Pb, the lighter homologs of the superheavy elements (SHE) copernicium (Cn, Z =112), nihonium (Nh, Z =113), and flerovium (Fl, Z =114), were carried out using short-lived radioisotopes. The interaction with Au and SiO 2 surfaces was studied and the overall chemical yield was determined. Suitable radioisotopes were produced in fusion-evaporation reactions, isolated in the gas-filled recoil separator TASCA, and flushed rapidly to an adjacent setup of two gas chromatography detector arrays covered with SiO 2 (first array) and Au (second array). While Tl and Pb adsorbed on the SiO 2 surface, Hg interacts only weakly and reached the Au-covered array. Our results contribute to elucidating the influence of relativistic effects on chemical properties of the heaviest elements by providing experimental data on these lighter homologs