携带同源重组修复相关基因突变的消化道肿瘤的临床特点

目的:探讨消化道肿瘤中同源重组修复相关基因(homologous recombination repair related gene，HRR)突变的发生情况及临床意义。方法:共92例消化道肿瘤患者，79例患者进行了血液标本HRR检测，53例患者进行了组织标本HRR检测，40例患者同时行血液和组织的HRR基因检测，收集患者基因检测结果及临床相关资料。结果:在79例患者血液标本检测中发现10例（12.6%）有临床意义HRR突变，在53例患者组织标本检测中发现9例（17.0%）有临床意义HRR突变。40例同时行血液和组织的HRR基因检测患者中常见的有临床意义HRR突变为CDK12突变4例（10.0%）、ATM突变3例（7.5%）、BRCA1突变2例（5.0%）。13例有临床意义HRR突变患者中常见共存突变为TP53突变10例（76.9%）、APC突变5例（38.5%）、PIK3CA突变4例（30.8%）。40例患者中13例患者血液和/或组织中有临床意义HRR突变，27例患者血液和组织中均无任何临床意义HRR突变且两组相比，有临床意义HRR突变组肿瘤突变负荷（tumor mutational burden，TMB）为6.17(2.24～11.52)，而未携带HRR突变组TMB为0.4(0～3.75)，差异有统计学意义（P＜0.05）。40例患者组织检测中7例HRR有临床意义的突变，33例无HRR突变，血液检测中10例HRR有临床意义的突变，30例无HRR突变，一致性检验的Kappa值为0.333（P=0.031）。结论:携带有临床意义HRR突变的消化道肿瘤患者TMB更高，血液和组织检测HRR突变有较好的一致性。     

丹参酮生物合成相关SmERF108转录因子的鉴定及其靶基因分析＊

目的 鉴定与丹参酮合成相关转录因子AP2/ERF家族中SmERF108转录因子，并分析转录因子SmERF108的靶基因。方法 利用生物信息学在线分析平台如NCBI、PFAM等分析SmERF108的序列特征；MEGA-X软件用于构建SmERF108与不同功能转录因子的系统进化树；拟南芥原生质体转化法鉴定SmERF108蛋白的亚细胞定位；通过实时荧光定量PCR（Real-time qPCR）对SmERF108基因在丹参不同器官和组织差异表达进行检测；利用酵母体系对SmERF108的转录激活活性进行探究并用酵母单杂技术确定其靶基因。结果 SmERF108具有典型的AP2/ERF保守结构域，属于ERF-B3亚组，系统进化树和保守基序分析显示SmERF108与丹参中SmERF128、青蒿中AaERF2亲缘关系较近且保守基序分布一致；亚细胞定位显示SmERF108蛋白定位于细胞核；SmERF108基因在周皮中表达最高，且呈现周皮（R1）>韧皮部（R2）>木质部（R3）的规律；酵母自激活验证SmERF108具有转录激活活性，同时酵母单杂交确认其能与关键酶基因SmCPS1启动子结合。结论 鉴定到丹参中一个新转录因子SmERF108，生物信息学分析及差异表达分析预测与丹参酮合成相关，分子互作初步证实靶基因为SmCPS1二萜环化酶。     

Pan-cancer proteomic map of 949 human cell lines

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脊髓小脑共济失调2型家系ATXN2基因中间重复病例表型与分子遗传学特征

目的探讨脊髓小脑共济失调2型(SCA2)致病基因ATXN2异常等位基因中间重复个体的表型和分子遗传学特点。方法针对2005—2018年中日友好医院神经科运动障碍与神经遗传病研究中心收集的1383个常染色体显性遗传共济失调家系的先证者和部分家系成员,采用荧光标记毛细管电泳片段分析方法进行动态突变检测,对携带ATXN2基因中间重复的个体进行临床表型和遗传特征分析。结果共检出163个家系(包含先证者和家系成员共203人)携带异常扩展的ATXN2基因CAG重复序列,其中93个家系中有107例的异常扩展等位基因重复次数在29~34次之间。在其中的20个亲子对中,父系遗传16个,异常等位基因的代间扩展增加0~28次,母系遗传4个,异常等位基因的代间扩展增加0~4次。结论对于临床拟诊SCA2家系患者,需对其亲代或成年子代个体进行ATXN2基因检测,以免漏诊。动态突变基因检测有助于识别中间重复的个体,对明确家系致病基因和遗传咨询至关重要。     

Contribution of different somatosensory afferent input to subcortical somatosensory evoked potentials in humans

ObjectivesTo investigate the subcortical somatosensory evoked potentials (SEPs) to electrical stimulation of either muscle or cutaneous afferents.MethodsSEPs were recorded in 6 patients suffering from Parkinson’s disease (PD) who underwent electrode implantation in the pedunculopontine (PPTg) nucleus area. We compared SEPs recorded from the scalp and from the intracranial electrode contacts to electrical stimuli applied to: 1) median nerve at the wrist, 2) abductor pollicis brevis motor point, and 3) distal phalanx of the thumb. Also the high-frequency oscillations (HFOs) were analysed.ResultsAfter median nerve and pure cutaneous (distant phalanx of the thumb) stimulation, a P1-N1 complex was recorded by the intracranial lead, while the scalp electrodes recorded the short-latency far-field responses (P14 and N18). On the contrary, motor point stimulation did not evoke any low-frequency component in the PPTg traces, nor the N18 potential on the scalp. HFOs were recorded to stimulation of all modalities by the PPTg electrode contacts.ConclusionsStimulus processing within the cuneate nucleus depends on modality, since only the cutaneous input activates the complex intranuclear network possibly generating the scalp N18 potential.SignificanceOur results shed light on the subcortical processing of the somatosensory input of different modalities.     

Enlarged high frequency oscillations of the median nerve somatosensory evoked potential and survival in amyotrophic lateral sclerosis

ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons.     

An ultrasonographic monitoring of skin condition in patients receiving radiotherapy for head and neck cancers

Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy.