94 research outputs found
Drosophila SWR1 and NuA4 complexes are defined by DOMINO isoforms
Histone acetylation and deposition of H2A.Z variant are integral aspects of active transcription. In Drosophila, the single DOMINO chromatin regulator complex is thought to combine both activities via an unknown mechanism. Here we show that alternative isoforms of the DOMINO nucleosome remodeling ATPase, DOM-A and DOM-B, directly specify two distinct multi-subunit complexes. Both complexes are necessary for transcriptional regulation but through different mechanisms. The DOM-B complex incorporates H2A.V (the fly ortholog of H2A.Z) genome-wide in an ATP-dependent manner, like the yeast SWR1 complex. The DOM-A complex, instead, functions as an ATP-independent histone acetyltransferase complex similar to the yeast NuA4, targeting lysine 12 of histone H4. Our work provides an instructive example of how different evolutionary strategies lead to similar functional separation. In yeast and humans, nucleosome remodeling and histone acetyltransferase complexes originate from gene duplication and paralog specification. Drosophila generates the same diversity by alternative splicing of a single gene
Significance of tumour regression in lymph node metastases of gastric and gastro-oesophageal junction adenocarcinomas.
The presence of lymph node (LN) metastases is one of the most important negative prognostic factors in upper gastrointestinal carcinomas. Tumour regression similar to that in primary tumours can be observed in LN metastases after neoadjuvant therapy. We evaluated the prognostic impact of histological regression in LNs in 480 adenocarcinomas of the stomach and gastro-oesophageal junction after neoadjuvant chemotherapy. Regressive changes in LNs (nodular and/or hyaline fibrosis, sheets of foamy histiocytes or acellular mucin) were assessed by histology. In total, regressive changes were observed in 128 of 480 patients. LNs were categorised according to the absence or presence of both residual tumour and regressive changes (LN-/+ and Reg-/+). 139 cases were LN-/Reg-, 28 cases without viable LN metastases revealed regressive changes (LN-/Reg+), 100 of 313 cases with LN metastases showed regressive changes (LN+/Reg+), and 213 of 313 metastatic LN had no signs of regression (LN+/Reg-). Overall, LN/Reg categorisation correlated with overall survival with the best prognosis for LN-/Reg- and the worst prognosis for LN+/Reg- (p < 0.001). LN-/Reg+ cases had a nearly significant better outcome than LN+/Reg+ (p = 0.054) and the latter had a significantly better prognosis than LN+/Reg- (p = 0.01). The LN/Reg categorisation was also an independent prognostic factor in multivariate analysis (HR = 1.23; 95% CI 1.1-1.38; p < 0.001). We conclude that the presence of regressive changes after neoadjuvant treatment in LNs and LN metastases of gastric and gastro-oesophageal junction cancers is a relevant prognostic factor
Towards high-speed optical quantum memories
Quantum memories, capable of controllably storing and releasing a photon, are
a crucial component for quantum computers and quantum communications. So far,
quantum memories have operated with bandwidths that limit data rates to MHz.
Here we report the coherent storage and retrieval of sub-nanosecond low
intensity light pulses with spectral bandwidths exceeding 1 GHz in cesium
vapor. The novel memory interaction takes place via a far off-resonant
two-photon transition in which the memory bandwidth is dynamically generated by
a strong control field. This allows for an increase in data rates by a factor
of almost 1000 compared to existing quantum memories. The memory works with a
total efficiency of 15% and its coherence is demonstrated by directly
interfering the stored and retrieved pulses. Coherence times in hot atomic
vapors are on the order of microsecond - the expected storage time limit for
this memory.Comment: 13 pages, 5 figure
Prevention of incisional hernia with prophylactic onlay and sublay mesh reinforcement vs. primary suture only in midline laparotomies (PRIMA):long-term outcomes of a multicentre, double-blind, randomised controlled trial
Background: Incisional hernia occurs approximately in 40% of high-risk patients after midline laparotomy. Prophylactic mesh placement has shown promising results, but long-term outcomes are needed. The present study aimed to assess the long-term incisional hernia rates of the previously conducted PRIMA trial with radiological follow-up. Methods: In the PRIMA trial, patients with increased risk of incisional hernia formation (AAA or BMI ≥27 kg/m2) were randomised in a 1:2:2 ratio to primary suture, onlay mesh or sublay mesh closure in three different countries in eleven institutions. Incisional hernia during follow-up was diagnosed by any of: CT, ultrasound and physical examination, or during surgery. Assessors and patients were blinded until 2-year follow-up. Time-to-event analysis according to intention-to-treat principle was performed with the Kaplan–Meier method and Cox proportional hazard models. Trial registration: NCT00761475 (ClinicalTrials.gov). Findings: Between 2009 and 2012, 480 patients were randomized: 107 primary suture, 188 onlay mesh and 185 sublay mesh. Five-year incisional hernia rates were 53.4% (95% CI: 40.4–64.8), 24.7% (95% CI: 12.7–38.8), 29.8% (95% CI: 17.9–42.6), respectively. Compared to primary suture, onlay mesh (HR: 0.390, 95% CI: 0.248–0.614, p < 0.001) and sublay mesh (HR: 0.485, 95% CI: 0.309–0.761, p = 0.002) were associated with a significantly lower risk of incisional hernia development. Interpretation: Prophylactic mesh placement remained effective in reducing incisional hernia occurrence after midline laparotomy in high-risk patients during long-term follow-up. Hernia rates in the primary suture group were higher than previously anticipated. Funding: B. Braun.</p
Prevention of incisional hernia with prophylactic onlay and sublay mesh reinforcement vs. primary suture only in midline laparotomies (PRIMA):long-term outcomes of a multicentre, double-blind, randomised controlled trial
Background: Incisional hernia occurs approximately in 40% of high-risk patients after midline laparotomy. Prophylactic mesh placement has shown promising results, but long-term outcomes are needed. The present study aimed to assess the long-term incisional hernia rates of the previously conducted PRIMA trial with radiological follow-up. Methods: In the PRIMA trial, patients with increased risk of incisional hernia formation (AAA or BMI ≥27 kg/m2) were randomised in a 1:2:2 ratio to primary suture, onlay mesh or sublay mesh closure in three different countries in eleven institutions. Incisional hernia during follow-up was diagnosed by any of: CT, ultrasound and physical examination, or during surgery. Assessors and patients were blinded until 2-year follow-up. Time-to-event analysis according to intention-to-treat principle was performed with the Kaplan–Meier method and Cox proportional hazard models. Trial registration: NCT00761475 (ClinicalTrials.gov). Findings: Between 2009 and 2012, 480 patients were randomized: 107 primary suture, 188 onlay mesh and 185 sublay mesh. Five-year incisional hernia rates were 53.4% (95% CI: 40.4–64.8), 24.7% (95% CI: 12.7–38.8), 29.8% (95% CI: 17.9–42.6), respectively. Compared to primary suture, onlay mesh (HR: 0.390, 95% CI: 0.248–0.614, p < 0.001) and sublay mesh (HR: 0.485, 95% CI: 0.309–0.761, p = 0.002) were associated with a significantly lower risk of incisional hernia development. Interpretation: Prophylactic mesh placement remained effective in reducing incisional hernia occurrence after midline laparotomy in high-risk patients during long-term follow-up. Hernia rates in the primary suture group were higher than previously anticipated. Funding: B. Braun.</p
Defining the RBPome of primary T helper cells to elucidate higher-order Roquin-mediated mRNA regulation
Post-transcriptional gene regulation in T cells is dynamic and complex as targeted transcripts respond to various factors. This is evident for the Icos mRNA encoding an essential costimulatory receptor that is regulated by several RNA-binding proteins (RBP), including Roquin-1 and Roquin-2. Here, we identify a core RBPome of 798 mouse and 801 human T cell proteins by utilizing global RNA interactome capture (RNA-IC) and orthogonal organic phase separation (OOPS). The RBPome includes Stat1, Stat4 and Vav1 proteins suggesting unexpected functions for these transcription factors and signal transducers. Based on proximity to Roquin-1, we select \~50 RBPs for testing coregulation of Roquin-1/2 targets by induced expression in wild-type or Roquin-1/2-deficient T cells. Besides Roquin-independent contributions from Rbms1 and Cpeb4 we also show Roquin-1/2-dependent and target-specific coregulation of Icos by Celf1 and Igf2bp3. Connecting the cellular RBPome in a post-transcriptional context, we find contributions from multiple RBPs to the prototypic regulation of mRNA targets by individual trans-acting factors
Quantum optical memory protocols in atomic ensembles
We review a series of quantum memory protocols designed to store the quantum
information carried by light into atomic ensembles. In particular, we show how
a simple semiclassical formalism allows to gain insight into various memory
protocols and to highlight strong analogies between them. These analogies
naturally lead to a classification of light storage protocols into two
categories, namely photon echo and slow-light memories. We focus on the storage
and retrieval dynamics as a key step to map the optical information into the
atomic excitation. We finally review various criteria adapted for both
continuous variables and photon-counting measurement techniques to certify the
quantum nature of these memory protocols
Prospective, observational, multicenter study on minimally invasive gastrectomy for gastric cancer: robotic, laparoscopic and open surgery compared on operative and follow-up outcomes - IMIGASTRIC II study protocol: IMIGASTRIC II
Background:Several meta-analyses have tried to defi ne the role of minimally invasive approaches. However, further evidence to get a wider spread of these methods is necessary. Current studies describe minimally invasive surgery as a possible alternative to open surgery but deserving further clarifi cation. However, despite the increasing interest, the difficulty of planning prospective studies of adequate size accounts for the low level of evidence, which is mostly based on retrospective experiences.A multi-institutional prospective study allows the collection of an impressive amount of data to investigate various aspects of minimally invasive procedures with the opportunity of developing several subgroup analyses.A prospective data collection with high methodological quality on minimally invasive and open gastrectomies can clarify the role of diff erent procedures with the aim to develop specifi c guidelines.Methods and analysis:a multi-institutional prospective database will be established including information on surgical, clinical and oncological features of patients treated for gastric cancer with robotic, laparoscopic or open approaches and subsequent follow-up.The study has been shared by the members of the International study group on Minimally Invasive surgery for GASTRIc Cancer (IMIGASTRIC)The database is designed to be an international electronic submission system and a HIPPA protected real time data repository from high volume gastric cancer centers.Ethics:This study is conducted in compliance with ethical principles originating from the Helsinki Declaration, within the guidelines of Good Clinical Practice and relevantlaws/regulations.Trial registration number:NCT0275108
Rational design of an orthogonal tryptophanyl nonsense suppressor tRNA
While a number of aminoacyl tRNA synthetase (aaRS):tRNA pairs have been engineered to alter or expand the genetic code, only the Methanococcus jannaschii tyrosyl tRNA synthetase and tRNA have been used extensively in bacteria, limiting the types and numbers of unnatural amino acids that can be utilized at any one time to expand the genetic code. In order to expand the number and type of aaRS/tRNA pairs available for engineering bacterial genetic codes, we have developed an orthogonal tryptophanyl tRNA synthetase and tRNA pair, derived from Saccharomyces cerevisiae. In the process of developing an amber suppressor tRNA, we discovered that the Escherichia coli lysyl tRNA synthetase was responsible for misacylating the initial amber suppressor version of the yeast tryptophanyl tRNA. It was discovered that modification of the G:C content of the anticodon stem and therefore reducing the structural flexibility of this stem eliminated misacylation by the E. coli lysyl tRNA synthetase, and led to the development of a functional, orthogonal suppressor pair that should prove useful for the incorporation of bulky, unnatural amino acids into the genetic code. Our results provide insight into the role of tRNA flexibility in molecular recognition and the engineering and evolution of tRNA specificity
- …