2,363 research outputs found
Household Borrowing Constraints and Residential Investment Dynamics
Why does residential investment lead output in the US and Canada but it is coincident in other industrialized countries? In this paper we explore the role of home-equity loans used to boost consumption as a channel that affects residential investment. Towards this end, we consider a multi
Neck control after definitive radiochemotherapy without planned neck dissection in node-positive head and neck cancers
<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate neck control outcomes after definitive radiochemotherapy without planned neck dissection in node-positive head and neck cancer.</p> <p>Methods</p> <p>We retrospectively reviewed medical records of fifty patients with node-positive head and neck cancer who received definitive radiochemotherapy. Twelve patients subsequently underwent neck dissection for suspicious recurrent or persistent disease. A median dose of 70 Gy (range 60-70.6) was delivered to involved nodes. Response evaluation was performed at a median of 5 weeks after completion of radiotherapy.</p> <p>Results</p> <p>Neck failure was observed in 11 patients and the 3-year regional control (RC) rate was 77.1%. Neck dissection was performed in 10 of the 11 patients; seven of these cases were successfully salvaged, and the ultimate rate of neck control was 92%. The remaining two patients who received neck dissection had negative pathologic results. On univariate analysis, initial nodal size > 2 cm, a less-than-complete response at the primary site, post-radiotherapy nodal size > 1.5 cm, and post-radiotherapy nodal necrosis were associated with RC. On multivariate analysis, less-than-complete primary site response and post-radiotherapy nodal necrosis were identified as independent prognostic factors for RC.</p> <p>Conclusions</p> <p>The neck failure rate after definitive radiochemotherapy without planned neck dissection was 22%. Two-thirds of these were successfully salvaged with neck dissection and the ultimate neck control rate was 92%. Our results suggest that planned neck dissection might not be necessary in patients with complete response of primary site, no evidence of residual lesion > 1.5 cm, or no necrotic lymph nodes at the 1-2 months follow-up evaluation after radiotherapy.</p
The bent conformation of poly(A)-binding protein induced by RNA-binding is required for its translational activation function
A recent study revealed that poly(A)-binding protein (PABP) bound to poly(A) RNA exhibits a sharply bent configuration at the linker region between RNA-recognition motif 2 (RRM2) and RRM3, whereas free PABP exhibits a highly flexible linear configuration. However, the physiological role of the bent structure of mRNA-bound PABP remains unknown. We investigated a role of the bent structure of PABP by constructing a PABP variant that fails to form the poly(A)-dependent bent structure but maintains its poly (A)-binding activity. We found that the bent structure of PABP/poly(A) complex is required for PABP's efficient interaction with eIF4G and eIF4G/eIF4E complex. Moreover, the mutant PABP had compromised translation activation function and failed to augment the formation of 80S translation initiation complex in an in vitro translation system. These results suggest that the bent conformation of PABP, which is induced by the interaction with 30 poly(A) tail, mediates poly(A)-dependent translation by facilitating the interaction with eIF4G and the eIF4G/eIF4E complex. The preferential binding of the eIF4G/eIF4E complex to the bent PABP/poly(A) complex seems to be a mechanism discriminating the mRNA-bound PABPs participating in translation from the idling mRNA-unbound PABPs.111Ysciescopu
Feasibility of fetoscopic laser coagulation in triplet pregnancy
Objective To report the experiences of triplet pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser coagulation at a single center. Methods Herein, we conducted a retrospective analysis to investigate the management and perinatal outcomes of triplet pregnancies with TTTS treated at a single institution between 2017 and 2022. Results Seven of the 98 triplet pregnancies (7.1%) encountered were complicated by TTTS, and all were dichorionic triamniotic triplets. Of the seven triplet pregnancies complicated by TTTS, four were treated with fetoscopic laser coagulation at our center, at a median gestational age of 20 weeks. No procedure-related complications or maternal complications were observed. The survival rate was higher and perinatal outcomes were better in fetoscopic laser coagulation cases than in other management cases. Four donor and four recipient triplets survived, with a median gestational age of 33 weeks at delivery. Although there were no cases of poor neonatal outcomes, one case was diagnosed with white matter injury, suspected to be hypoxic-ischemic encephalopathy on postnatal investigation. Conclusion Fetoscopic laser coagulation is a feasible treatment option for triplet TTTS, provided the attending specialists have extensive experience with this technique
An mRNA-specific tRNAi carrier eIF2A plays a pivotal role in cell proliferation under stress conditions: Stress-resistant translation of c-Src mRNA is mediated by eIF2A
c-Src, a non-receptor protein tyrosine kinase, activates NF-��B and STAT3, which in turn triggers the transcription of anti-apoptosis- and cell cycle-related genes. c-Src protein regulates cell proliferation, cell motility and programmed cell death. And the elevated level of activated c-Src protein is related with solid tumor generation. Translation of c-Src mRNA is directed by an IRES element which mediates persistent translation under stress conditions when translation of most mRNAs is inhibited by a phosphorylation of the alpha subunit of eIF2 carrying the initiator tRNA (tRNAi) to 40S ribosomal subunit under normal conditions. The molecular basis of the stress-resistant translation of c-Src mRNA remained to be elucidated. Here, we report that eIF2A, an alternative tRNAi carrier, is responsible for the stress-resistant translation of c-Src mRNA. eIF2A facilitates tRNAi loading onto the 40S ribosomal subunit in a c-Src mRNAdependent manner. And a direct interaction between eIF2A and a stem-loop structure (SL I) in the c-Src IRES is required for the c-Src IRES-dependent translation under stress conditions but not under normal conditions. Finally, we showed that the eIF2Adependent translation of c-Src mRNA plays a pivotal role in cell proliferation under stress conditions. ? The Author(s) 2016.115sciescopu
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