The catalytic activity of REV1 is employed during immunoglobulin gene diversification in DT40

REV1 plays a key role in vertebrate translesion synthesis. Although its deoxycytidyl transferase activity is dispensable for tolerance of DNA damage caused by a number of mutagens, its extreme C terminus, which interacts with other translesion polymerases and PCNA, is essential. By examining immunoglobulin diversification in the genetically tractable chicken cell line DT40 we show that the generation of non-templated point mutations from C/G to G/C does require the catalytic activity of REV1. This provides the first clear evidence that the catalytic activity of REV1 is utilised in vivo in higher eukaryotes and is involved in immunoglobulin diversification. Although rev1 DT40 cells incorporate few point mutations, a mutant lacking the C terminus of REV1 exhibits a similar level to that seen in wild-type cells. Thus, the polymerase selection or stabilisation role of REV1 does not appear to play a major role in the bypass of AID-dependent abasic sites.     

Decreased CK1δ expression predicts prolonged survival in colorectal cancer patients

Tumor Biology - Cancers arising from the large intestine or rectum are called colorectal cancer (CRC) and represent the fourth leading cause of cancer-related death worldwide. Since casein kinase 1...     

Perioperative red blood cell transfusion is associated with poor functional outcome and overall survival in patients with newly diagnosed glioblastoma

The influence of perioperative red blood cell (RBC) transfusion on prognosis of glioblastoma patients continues to be inconclusive. The aim of the present study was to evaluate the association between perioperative blood transfusion (PBT) and overall survival (OS) in patients with newly diagnosed glioblastoma. Between 2013 and 2018, 240 patients with newly diagnosed glioblastoma underwent surgical resection of intracerebral mass lesion at the authors’ institution. PBT was defined as the transfusion of RBC within 5 days from the day of surgery. The impact of PBT on overall survival was assessed using Kaplan–Meier analysis and multivariate regression analysis. Seventeen out of 240 patients (7%) with newly diagnosed glioblastoma received PBT. The overall median number of blood units transfused was 2 (95% CI 1–6). Patients who received PBT achieved a poorer median OS compared to patients without PBT (7 versus 18 months; p?<?0.0001). Multivariate analysis identified “age >?65 years” (p?<?0.0001, OR 6.4, 95% CI 3.3–12.3), “STR” (p?=?0.001, OR 3.2, 95% CI 1.6–6.1), “unmethylated MGMT status” (p?<?0.001, OR 3.3, 95% CI 1.7–6.4), and “perioperative RBC transfusion” (p?=?0.01, OR 6.0, 95% CI 1.5–23.4) as significantly and independently associated with 1-year mortality. Perioperative RBC transfusion compromises survival in patients with glioblastoma indicating the need to minimize the use of transfusions at the time of surgery. Obeying evidence-based transfusion guidelines provides an opportunity to reduce transfusion rates in this population with a potentially positive effect on survival.

     

Context-aware Augmented Reality in laparoscopic surgery

Augmented Reality is a promising paradigm for intraoperative assistance. Yet, apart from technical issues, a major obstacle to its clinical application is the man–machine interaction. Visualization of unnecessary, obsolete or redundant information may cause confusion and distraction, reducing usefulness and acceptance of the assistance system.We propose a system capable of automatically filtering available information based on recognized phases in the operating room. Our system offers a specific selection of available visualizations which suit the surgeon's needs best. The system was implemented for use in laparoscopic liver and gallbladder surgery and evaluated in phantom experiments in conjunction with expert interviews.     

Bridging the gap between formal and experience-based knowledge for context-aware laparoscopy

Purpose

Computer assistance is increasingly common in surgery. However, the amount of information is bound to overload processing abilities of surgeons. We propose methods to recognize the current phase of a surgery for context-aware information filtering. The purpose is to select the most suitable subset of information for surgical situations which require special assistance.

Methods

We combine formal knowledge, represented by an ontology, and experience-based knowledge, represented by training samples, to recognize phases. For this purpose, we have developed two different methods. Firstly, we use formal knowledge about possible phase transitions to create a composition of random forests. Secondly, we propose a method based on cultural optimization to infer formal rules from experience to recognize phases.

Results

The proposed methods are compared with a purely formal knowledge-based approach using rules and a purely experience-based one using regular random forests. The comparative evaluation on laparoscopic pancreas resections and adrenalectomies employs a consistent set of quality criteria on clean and noisy input. The rule-based approaches proved best with noisefree data. The random forest-based ones were more robust in the presence of noise.

Conclusion

Formal and experience-based knowledge can be successfully combined for robust phase recognition.

     

Surgery for temporal glioblastoma: lobectomy outranks oncosurgical-based gross-total resection

Journal of Neuro-Oncology - Supra-total glioblastoma resection has gained growing attention with regard to superior long-term disease control. However, aggressive onco-surgical...     

Seizure outcome in temporal glioblastoma surgery: lobectomy as a supratotal resection regime outclasses conventional gross-total resection

Journal of Neuro-Oncology - The graphic abstract was missing in the original online publication. The original article has been corrected.     

Safety metric profiling in surgery for temporal glioblastoma: lobectomy as a supra-total resection regime preserves perioperative standard quality rates

Journal of Neuro-Oncology - Conflicting results have been reported in the association between glioblastoma proximity to the subventricular zone (SVZ) and enrichment of cancer stem cell properties....     

Newly diagnosed glioblastoma in geriatric (65 +) patients: impact of patients frailty,comorbidity burden and obesity on overall survival

Journal of Neuro-Oncology - Increasing age is a known negative prognostic factor for glioblastoma. However, a multifactorial approach is necessary to achieve optimal neuro-oncological treatment. It...