102 research outputs found
Epigenetic Engineering of Ribosomal RNA Genes Enhances Protein Production
Selection of mammalian high-producer cell lines remains a major challenge for the biopharmaceutical manufacturing industry. Ribosomal RNA (rRNA) genes encode the major component of the ribosome but many rRNA gene copies are not transcribed [1]–[5] due to epigenetic silencing by the nucleolar remodelling complex (NoRC) [6], which may limit the cell's full production capacity. Here we show that the knockdown of TIP5, a subunit of NoRC, decreases the number of silent rRNA genes, upregulates rRNA transcription, enhances ribosome synthesis and increases production of recombinant proteins. However, general enhancement of rRNA transcription rate did not stimulate protein synthesis. Our data demonstrates that the number of transcriptionally competent rRNA genes limits efficient ribosome synthesis. Epigenetic engineering of ribosomal RNA genes offers new possibilities for improving biopharmaceutical manufacturing and provides novel insights into the complex regulatory network which governs the translation machinery in normal cellular processes as well as in pathological conditions like cancer
Efficacy of polyethylene glycol adhesion barrier after gynecological laparoscopic surgery: Results of a randomized controlled pilot study
Postoperative adhesions are the most frequent complication of peritoneal surgery, causing small bowel obstruction, female infertility and chronic pain. This pilot study assessed the efficacy of a sprayable polyethylene glycol (PEG) barrier in the prevention of de novo adhesions. 16 patients undergoing laparoscopic gynecological surgery were randomly assigned by shuffled sealed envelopes to receive either the adhesion barrier or no adhesion prevention. Incidence and severity of adhesions were scored at eight sites in the pelvis and reassessed by second look laparoscopy. Adhesion prevention was considered successful if no de novo adhesion were found at second look laparoscopy. One patient was excluded before randomization. Nine patients were randomized to treatment and six patients to control group. De novo adhesions were found in 0/9 patients who received the PEG barrier compared to 4/6 without adhesion prevention (0% vs. 67%, P = 0.01). Reduction in adhesion score was significantly greater in patients receiving PEG barrier (−2.6 vs. −0.06, P = 0.03). Meta-analysis of three randomized trials demonstrated that PEG barrier reduces the incidence of adhesions (odds ratio [OR] = 0.27; 95% CI 0.11–0.67). From this study, PEG barrier seems effective in reducing postoperative formation of de novo adhesions
Fungal chitinases: diversity, mechanistic properties and biotechnological potential
Chitin derivatives, chitosan and substituted chito-oligosaccharides have a wide spectrum of applications ranging from medicine to cosmetics and dietary supplements. With advancing knowledge about the substrate-binding properties of chitinases, enzyme-based production of these biotechnologically relevant sugars from biological resources is becoming increasingly interesting. Fungi have high numbers of glycoside hydrolase family 18 chitinases with different substrate-binding site architectures. As presented in this review, the large diversity of fungal chitinases is an interesting starting point for protein engineering. In this review, recent data about the architecture of the substrate-binding clefts of fungal chitinases, in connection with their hydrolytic and transglycolytic abilities, and the development of chitinase inhibitors are summarized. Furthermore, the biological functions of chitinases, chitin and chitosan utilization by fungi, and the effects of these aspects on biotechnological applications, including protein overexpression and autolysis during industrial processes, are discussed in this review
Supporting first-grade writers who fail to learn: multiple single-case evaluation of a response to intervention approach
We report a multiple-baseline single-case study, based in the response to intervention framework, evaluating transcription-only and transcription-and-planning interventions for young, struggling writers. In a baseline phase, 8 classes of Spanish children at the start of their first year of primary (elementary) education completed short, probe writing tasks twice-weekly over the first 120 days of their school career. During this period, all students received researcher-developed classroom instruction in spelling, handwriting, and text-planning. Students then completed a battery of tests including measures of spelling, handwriting and composition quality. On the basis of writing probe tasks and test scores we identified 12 struggling writers for whose written composition performance was below the 15th percentile, relative to the full sample, whose spelling performance was below 25th percentile, and whose handwriting was poor. For the next 72 days, these students received twice-weekly, parent-delivered training in transcription skills (handwriting and spelling) or transcription skills plus text planning. Researcher-developed classroom instruction and regular probe tasks continued during this phase. All students, in both intervention conditions, showed improvement in handwriting quality relative to Phase 1. 10 students also showed improvement in composition quality, with 8 performing, post intervention, within normal range relative to peers. Our findings demonstrate the value of a response-to-intervention approach to identification and remediation for struggling writes in their first school year
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