宝石能谱CT对胃癌区域淋巴结转移的诊断价值

目的 研究宝石能谱CT（gemstone spectral CT,GSCT）对胃癌区域淋巴结转移的诊断价值。方法 回顾分析52例胃镜下组织学活检证实为胃癌并行GSCT（GSCT 组,24 例）或双源CT（dual source CT,DSCT）（DSCT 组,28 例）的患者,两组除常规CT增强检查外,GSCT在动脉期应用能谱成像GSI（gemstone spectral imaging）软件,获得区域转移淋巴结与胃癌病变的能谱衰减曲线,对比分析两组CT结果与术后病理结果符合率及GSCT 对转移淋巴结评估的准确性。结果 通过计算淋巴结大小、CT 值差值及短长径比值的方法,GSCT 组评估淋巴结转移与病理符合率高于DSCT 组（P＜0.05）;胃癌及转移淋巴结能谱分析结果无统计学差异（P≥0.05）。结论 GSCT 检查胃癌区域淋巴结转移与病理结果的一致性高于DSCT;GSCT可对胃癌术前转移淋巴结进行详细判断,并对术前评估提供了理论依据和技术支持,具有重要的临床应用价值。     

O-GIcNAc 转移酶在直肠癌中的分布及其对预后的影响

目的了解O-GIcNAc转移酶(O-GlcNAc transferase,OGT)在直肠癌中的表达情况及对预后的影响。方法利用免疫组化技术,在直肠癌组织芯片上染色OGT,确定表达情况,并与患者临床资料结合,了解OGT的表达与直肠癌患者的生存是否有差异。结果OGT 在直肠癌组织中的表达情况：“- ”12.22%、“+”27.78%、“++”44.44%、“+++”15.56%,癌旁组织中的表达情况：“-”18.89%、“+”42.22%、“++”37.78%、“+++”1.11% ;癌组织中OGT 高表达（++ 和+++）为60.00%,高于癌旁组织中OGT高标的量38.89%;OGT 高表达直肠癌患者的3年生存率分别是82.90%和60.00%,两者比较有统计学差异（字2=7.452,P=0.006）。结论 OGT在直肠癌中的表达高于周围正常组织,直肠癌中高表达的3年生存率较低,OGT可能参加了肿瘤的发生、发展过程。     

Bayesian Model Assessment in Joint Modeling of Longitudinal and Survival Data With Applications to Cancer Clinical Trials

Joint models for longitudinal and survival data are routinely used in clinical trials or other studies to assess a treatment effect while accounting for longitudinal measures such as patient-reported outcomes. In the Bayesian framework, the deviance information criterion (DIC) and the logarithm of the pseudo-marginal likelihood (LPML) are two well-known Bayesian criteria for comparing joint models. However, these criteria do not provide separate assessments of each component of the joint model. In this article, we develop a novel decomposition of DIC and LPML to assess the fit of the longitudinal and survival components of the joint model, separately. Based on this decomposition, we then propose new Bayesian model assessment criteria, namely, ΔDIC and ΔLPML, to determine the importance and contribution of the longitudinal (survival) data to the model fit of the survival (longitudinal) data. Moreover, we develop an efficient Monte Carlo method for computing the conditional predictive ordinate statistics in the joint modeling setting. A simulation study is conducted to examine the empirical performance of the proposed criteria and the proposed methodology is further applied to a case study in mesothelioma. Supplementary materials for this article are available online.     

Mathematical description of the interactions of CycE/Cdk2, Cdc25A,and P27Kip1 in a core cancer subnetwork

Recent studies have shown that the initiation of human cancer is due to the malfunction of some genes (such as E2F, CycE, CycD, Cdc25A, P27^Kip1, and Rb) at the R‐checkpoint during the G₁‐to‐S transition of the cell cycle. Identifying and modeling the dynamics of these genes provide new insight into the initiation and progression of many types of cancers. In this study, a cancer subnetwork that has a mutual activation between phosphatase Cdc25A and the CycE/Cdk2 complex and a mutual inhibition between the Cdk inhibitor P27^Kip1 and the CycE/Cdk2 complex is identified. A new mathematical model for the dynamics of this cancer subnetwork is developed. Positive steady states are determined and rigorously analyzed. We have found a condition for the existence of positive steady states from the activation, inhibition, and degradation parameter values of the dynamical system. We also found a robust condition that needs to be satisfied for the steady states to be asymptotically stable. We determine the parameter value(s) under which the system exhibits a saddle–node bifurcation. We also identify the condition for which the system exhibits damped oscillation solutions. We further explore the possibility of Hopf and homoclinic bifurcations from the saddle–focus steady state of the system. Our analytic and numerical results confirm experimental results in the literature, thus validating our model. Copyright © 2016 John Wiley & Sons, Ltd.