Diffusion-weighted magnetic resonance imaging for predicting the response of rectal cancer to neoadjuvant concurrent chemoradiation

AIM:To evaluate the clinical value of diffusion-weighted magnetic resonance imaging(DW-MRI)in predicting the response of rectal cancer to neoadjuvant chemoradiation.METHODS:This prospective study was approved by our institutional review board,and informed consent was obtained from each patient.Fifteen patients(median age 56 years)with locally advanced rectal cancer were treated in our hospital from June 2006 to December 2007.All patients were stageⅢB-C according to the results of MRI and endorectal ultrasound examinations.All patients underwent pelvic irradiation with 45 Gy/25 fx per 35 days.The concurrent chemotherapy regimen consisted of capecitabine 625mg/m2,bid(Monday-Friday),and oxaliplatin 50 mg/m2,weekly.The patients underwent surgery 5-8 wk after the completion of neoadjuvant therapy.T downstaging was defined as the downstaging of the tumor from cT3to ypT0-2 or from cT4 to ypT0-3.Good regression was defined as TRG 3-4,and poor regression was defined as TRG 0-2.Diffusion-weighted magnetic resonance images were obtained prior to and weekly during the course of neoadjuvant chemoradiation,and the apparent diffusion coefficient(ADC)values were calculated from the acquired tumor images.RESULTS:Comparison with the mean pretreatment tumor ADC revealed an increase in the mean tumor ADC during the course of neoadjuvant chemoradiation,especially at the 2ndweek(P=0.004).We found a strong negative correlation between the mean pretreatment tumor ADC and tumor regression after neoadjuvant chemoradiation(P=0.021).In the T downstage and tumor regression groups,we found a significant increase in the mean ADC at the 2ndweek of neoadjuvant therapy(P=0.011;0.004).CONCLUSION:DW-MRI might be a valuable clinical tool to help predict or assess the response of rectal cancer to neoadjuvant chemoradiation at an early timepoint.

Hilbert空间中求解伪单调变分不等式的自适应次梯度外梯度法

本文在实Hilbert空间上研究一种关于伪单调变分不等式的新算法.该算法结合次梯度外梯度法、惯性法和黏性法.在适当的条件下,引入不同的参数来改进算法的收敛性.最后,在数值试验中与相关结果作比较,展示所提算法的有效性.

具有非平凡Fourier型Banach空间的一个特征

设X为复Banach空间,则X具有非平凡Fourier型当且仅当存在(等价地,对所有)0<α<1,任取f∈C^(α)([0,2π];X)满足f(0)=f(2π),都有Σ_(n∈Z)||f(n)||^(1/α)<∞成立.

Etoposide,dexamethasone,and pegaspargase with sandwiched radiotherapy in early-stage natural killer/T-cell lymphoma:A randomized phase III study

Methotrexate,etoposide,dexamethasone,and pegaspargase(MESA)with sandwiched radiotherapy is known to be effective for early-stage extranodal natural killer/T-cell lymphoma,nasal type(NKTCL).We explored the efficacy and safety of reduced-intensity,non-intravenous etoposide,dexamethasone,and pegaspargase(ESA)with sandwiched radiotherapy.This multicenter,randomized,phase III trial enrolled patients aged between 14 and 70 years with newly diagnosed early-stage nasal NKTCL from 27 centers in China.Patients were randomly assigned(1:1)to receive ESA(pegaspargase 2,500 IU/m^(2)intramuscularly on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4)or MESA(methotrexate 1 g/m^(2)intravenously on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4,and pegaspargase 2,500 IU/m^(2)intramuscularly on day 5)regimen(four cycles),combined with sandwiched radiotherapy.

Structure and functional interactions of IN080 actin/Arp module

The presence and functions of nuclear actin have been controversial due to the lack of molecular mechanisms.Nuclear actin and actin?『elated proteins (Arps) are subunits of several chromatin remodelers, including the evolutionarily conserved IN080 chromatin-remodeling complex. Here, we present an improved cryo-EM structure of the yeast IN080 complex and the first 3D reconstruction of the IN080 actin/Arp module.The modular and subunit architecture is defined using a combination of subunit deletion analysis and published crosslinking-mass spectrometry. The functional interactions of the IN080 actin/Arp module with a nucleosome is 3D EM reconstructed in two different binding states. Nucleosomes initially bind to the Arp8 subunit and the substantial conformational changes maximize nucleosome contacts of the actin/Arp module, which could promote the bound nucleosome to be engaged onto the IN080 ATPase domain. Our findings suggest that the conserved nuclear actin/Arp module acts a conformational switch of the IN080 for nucleosome binding.

Structural fl exibility and functional interaction of Mediator Cdk8 module

Mediator is a highly conserved large protein complex(25 proteins,>1000 kD a)and preeminently responsible for eu-karyotic transcription,which contains a dissociable‘Cdk8 module’.Although increasing evidence demonstrates that Cdk8 module plays both positive and negative roles in transcription regulation,the detailed structure,and subu-nit organization,molecular mechanism how it regulates transcription remain elusive.Here we used single-particle electron microscopy to characterize the structure and subunit organization of the Cdk8 module and illuminated the substantial mobility of the Med13 subunit results in the structural fl exibility.The Cdk8 module interaction with core Mediator is concurrent with active transcription in vivo.An interaction with the Cdk8 module induces core Mediator into very extended conformation in vitro,which is presumed to be an active functional state of Mediator.Taken together,our results illuminated the detailed archi-tecture of Cdk8 module,and suggested the Cdk8 module could positively regulate transcription by modulating Me-diator conformation.

Periodic Solutions of Third-order Differential Equations with Finite Delay in Vector-valued Functional Spaces

In this paper, we study the well-posedness of the third-order differential equation with finite delay(P3): αu’"(t) + u"(t) = Au(t) + Bu’(t) + Fut +f(t)(t ∈ T := [0,2π]) with periodic boundary conditions u(0) = u(2π), u’(0) = u"(2π),u"(0)=u"(2π) in periodic Lebesgue-Bochner spaces Lp(T;X) and periodic Besov spaces Bp,qs(T;X), where A and B are closed linear operators on a Banach space X satisfying D(A) ∩ D(B) ≠ {0}, α≠ 0 is a fixed constant and F is a bounded linear operator from Lp([-2π, 0];X)(resp. Bp,qs([-2π, 0];X)) into X, ut is given by ut(s) = u(t + s) when s ∈ [-2π,0]. Necessary and sufficient conditions for the Lp-well-posedness(resp. Bp,qs-well-posedness)of(P3) are given in the above two function spaces. We also give concrete examples that our abstract results may be applied.

Inertial Viscosity Iterative Method for Solving Pseudo-monotone Variational Inequality Problems and Fixed Point Problems

In this paper,we investigate a new inertial viscosity extragradient algorithm for solving variational inequality problems for pseudo-monotone and Lipschitz continuous operator and fixed point problems for quasi-nonexpansive mappings in real Hilbert spaces.Strong convergence theorems are obtained under some appropriate conditions on the parameters.Finally,we give some numerical experiments to show the advantages of our proposed algorithms.The results obtained in this paper extend and improve some recent works in the literature.

Viscosity Iterative Algorithm for Variational Inequality Problems and Fixed Point Problems of Strict Pseudo-contractions in Uniformly Smooth Banach Spaces

The purpose of this paper is to study a new viscosity iterative algorithm based on a generalized contraction for finding a common element of the set of solutions of a general variational inequality problem for finite inversely strongly accretive mappings and the set of common fixed points for a countable family of strict pseudo-contractions in uniformly smooth Banach spaces. We prove some strong convergence theorems under some suitable conditions. The results obtained in this paper improve and extend the recent ones announced by many others in the literature.