强制性运动疗法对脑损伤性偏瘫患者上肢运动功能康复的疗效

目的 探讨脑损伤性偏瘫患者上肢运动功能康复的护理干预措施.方法 将50例脑损伤性偏瘫患者随机分为干预组和对照组,干预组在常规康复护理的基础上,加用强制性运动疗法等护理干预措施,对照组给予常规康复护理.比较两组在康复治疗3周末的疗效.结果 干预组显效率、有效率及总有效率均明显高于对照组,两组显效率比较(P＜0.05)、有效率比较(P＜0.05)、总有效率比较(P＜0.01)统计学检验有显著性差异.结论 对改善脑损伤性偏瘫患者上肢运动功能采用常规康复护理加强制性运动疗法,其疗效明显优于常规康复护理组.     

Plumbagin triggers DNA damage response,telomere dysfunction and genome instability of human breast cancer cells

AimNatural plant products are increasingly being used in cancer therapeutic studies due to their reduced normal cell toxicity. In this study, the anti-cancer properties of plumbagin, a naphthoquinone derivative extracted from the roots of Plumbago, were evaluated in breast cancer cells.MethodsTo evaluate the effects of plumbagin on breast cancer cell types, we employed a variety of techniques comprising cell viability, cell cycle assay, comet assay, western blotting, immunocytochemistry, measurement of telomerase activity, telomere restriction fragment length, quantitative fluorescence in situ hybridisation, along with gene expression analysis of untreated cells.ResultsPlumbagin treatment induced cytotoxicity in human breast cancer cells along with cell cycle arrest, DNA damage and cell death leading to apoptosis. Plumbagin was also found to suppress the telomerase activity in cancer cells accompanied by telomere attrition. Telomere shortening was corroborated by reduced telomere fluorescence on chromosome ends and genome instability.ConclusionTogether, these findings may suggest the application of plumbagin as adjuvant modality in breast cancer therapeutics.     

Changes in motor unit characteristics after eccentric elbow flexor exercise

Morphological evidence suggests that fast-twitch fibers are prone to disruption of their membrane structures by eccentric exercise. However, it is unclear how this is reflected in the discharge rate and action potential propagation of individual motor units, especially at high contraction levels. High-density surface electromyograms were recorded from biceps brachii muscle and decomposed to individual motor unit action potentials at isometric contraction levels between 10% and 75% of maximal voluntary contraction (MVC) before intermittent maximal elbow flexor eccentric exercise, and two hours (2H), two days (2D) and four days (4D) post-exercise. Maximal voluntary force decreased by 21.3±5.6% 2H and by 12.6±11.1% 2D post-exercise. Motor unit discharge rate increased and mean muscle fiber conduction velocity decreased, at the highest isometric contraction levels only (50% and 75% of MVC) at 2H post-exercise. These results indicate that eccentric exercise can disturb the function of motor units active at high contraction levels in the early stages after exercise, which seems to be compensated by the central nervous system with an increase in neural drive during submaximal isometric contractions.     

Effects of hypertonic (3%) saline in rats with circulatory shock and cerebral ischemia after heatstroke

Objective To evaluate the effects of hypertonic (3%) saline in heatstroke rats with circulatory shock, intracranial hypertension, and cerebral ischemia.Design and setting Urethane-anesthetized rats were exposed to a high ambient temperature of 42°C until mean arterial pressure and local cerebral blood flow (CBF) in the corpus striatum began to decrease from their peak levels, which was arbitrarily defined as the onset of heatstroke. Control rats were exposed to 24°C.Measurements and results Extracellular concentrations of glutamate and lactate/pyruvate ratio (cellular ischemia markers), and glycerol (a cellular injury marker) in the corpus striatum of rat brain were assessed by intracerebral microdialysis methods. Striatal PO₂, temperature, and local CBF were measured with a combined OxyLite PO₂, thermocouple, and OxyFlo LDF, respectively. The values of mean arterial pressure, cerebral perfusion pressure, and striatal CBF and PO₂ in rats treated with 0.9% NaCl solution after the onset of heatstroke were all significantly lower than those in normothermic controls. In contrast, the values of intracranial pressure, brain temperature, and extracellular concentrations of glutamate, glycerol, and lactate/pyruvate in the corpus striatum were greater. Intravenous infusion of hypertonic (3%) saline solution either "0" time before the start of heat exposure or right after the onset of heatstroke significantly attenuated the heatstroke-induced arterial hypotension, intracranial hypertension, decreased cerebral perfusion, and cerebral ischemia and damage and resulted in prolongation of survival time.Conclusions Our results strongly suggest that the experimental heatstroke syndromes can be effectively prevented and treated by hypertonic saline.An editorial regarding this article can be found in the same issue ()     

心肌背向散射积分参数评价左乳腺癌放疗早期心脏损伤

目的探讨心肌背向散射积分(IBS)参数评价左乳腺癌放疗早期心脏损伤的价值。方法35例左侧乳腺癌全程放疗患者按照放疗进程分为A组:放疗前;B组:放疗时间3周、照射剂量30Gy;C组:放疗时间5周、照射剂量50Gy。对3组行心肌校正IBS(IBS%)、IBS周期变化幅度(CVIB)等背向散射积分参数及舒张早期二尖瓣口血流峰值速度/舒张晚期二尖瓣口血流峰值速度(E/A)等常规超声测定。结果C组前壁、前室间隔的IBS%高于A组差异有显著性(P<0.01),CVIB低于A组差异有显著性(P<0.01);C组前壁、前室间隔的IBS%高于B组差异有显著性(P<0.05),CVIB低于B组差异有显著性(P<0.05);C组左室舒张功能(E/A)较A组减低差异有显著性(P<0.01);C组左室舒张功能(E/A)较B组减低差异有显著性(P<0.05);B组各指标与A组比较差异无显著性意义(P>0.05)。结论心肌背向散射积分参数可无创、敏感、客观地评价左侧乳腺癌放疗对心脏的早期损伤。     

DeepSMILE: Contrastive self-supervised pre-training benefits MSI and HRD classification directly from H&E whole-slide images in colorectal and breast cancer

We propose a Deep learning-based weak label learning method for analyzing whole slide images (WSIs) of Hematoxylin and Eosin (H&E) stained tumor tissue not requiring pixel-level or tile-level annotations using Self-supervised pre-training and heterogeneity-aware deep Multiple Instance LEarning (DeepSMILE). We apply DeepSMILE to the task of Homologous recombination deficiency (HRD) and microsatellite instability (MSI) prediction. We utilize contrastive self-supervised learning to pre-train a feature extractor on histopathology tiles of cancer tissue. Additionally, we use variability-aware deep multiple instance learning to learn the tile feature aggregation function while modeling tumor heterogeneity. For MSI prediction in a tumor-annotated and color normalized subset of TCGA-CRC (n=360 patients), contrastive self-supervised learning improves the tile supervision baseline from 0.77 to 0.87 AUROC, on par with our proposed DeepSMILE method. On TCGA-BC (n=1041 patients) without any manual annotations, DeepSMILE improves HRD classification performance from 0.77 to 0.81 AUROC compared to tile supervision with either a self-supervised or ImageNet pre-trained feature extractor. Our proposed methods reach the baseline performance using only 40% of the labeled data on both datasets. These improvements suggest we can use standard self-supervised learning techniques combined with multiple instance learning in the histopathology domain to improve genomic label classification performance with fewer labeled data.     

高压氧对脑缺血再灌注致线粒体过氧化损伤的保护作用研究

目的 通过观察高压氧(HBO)对局灶性脑缺血再灌注(CI/R)所致脑组织细胞线粒体过氧化损伤及凋亡的影响,探讨HBO对抗CI/R损伤的作用及其机制.方法 将80只SD大鼠按随机数字表法分为4组:假手术对照组(假手术组)8只,CI/R组、CI/R后常压吸氧(CI/R+N)组、CI/R后HBO治疗(CI/R+HBO)组,每组24只.采用大脑中动脉内线栓阻断法(MCAO)制备大鼠局灶性CI/R模型.(假手术组)操作步骤相同,但仅将线栓插入大脑中动脉10 mm后退出.假手术组、CI/R组术后不予任何处理,CI/R+N组术后30 min常压下吸纯氧,CI/R+HBO组术后30 min行常规HBO处理,均为60 min/次,1次/12 h.每组于CI/R术后12、24、48 h各处死8只大鼠,取CI/R损伤灶脑组织,采用比色法检测脑组织内线粒体超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量,流式细胞技术检测脑细胞凋亡率.结果 CI/R组术后12、24、48 h SOD活性持续下降,显著低于假手术组[(139.21±11.52与(214.13±13.76)、(127.41±12.36)与(214.13±13.76)、(112.33±11.69)与(214.33±13.76)×10-6U/g)](均P＜0.01);CI/R+N组12、24、48 h SOD活性[(157.16±8.91)、(146.33±9.93)、(133.49±10.21)×10-6 U/g)]明显高于CI/R组(均P＜0.05),CI/R+HBO组12、24、48 h SOD活性[(176.80±12.35)、(169.43±12.41)、(161.56±13.81)×10-6 U/g)]显著高于CI/R组和CI/R+N组(均P＜0.05),显示CI/R后HBO治疗能有效地保护线粒体SOD的活性.CI/R组MDA含量术后持续增高,12、24、48 h显著高于假手术组(均P＜0.01).CI/R+N组MDA含量术后12、24、48 h时均低于CI/R组,但差异均无统计学意义(均P＞0.05);CI/R+HBO组MDA含量术后24、48 h时均显著低于CI/R组(均为P＜0.01)和CI/R+N48 h组(均P＜0.05),显示HBO治疗可有效抑制MDA的产生.CI/R组术后12、24、48 h脑细胞凋亡率持续增高,均显著高于假手术组(均P＜0.01);CI/R+N组术后24、48 h组脑细胞凋亡率均低于CI/R组,但差异无统计学意义(均P＞0.05);CI/R+HBO组术后24、48 h脑细胞凋亡率均显著低于CI/R组(均P＜0.05)和CUR+N 48 h组时(均P＜0.05);显示HBO治疗能有效降低CI/R后脑细胞凋亡率.结论 HBO治疗可明显增强细胞线粒体的稳定性,有效保护CI/R后脑组织线粒体SOD的活性,减轻大鼠CI/R所致线粒体过氧化损伤及脑细胞凋亡,较常压吸氧具有更显著的脑保护作用.     

氢饱和生理盐水对大鼠心肌缺血再灌注损伤的保护作用

目的 研究氢饱和生理盐水(氢水)对SD大鼠心肌缺血再灌注损伤的保护作用.方法 健康成年雄性SD大鼠36只,按数字表法随机分为假手术组、手术对照组(对照组)、氢水治疗组(氢水组),每组12只.假手术组只开胸,不做缺血再灌注处理;对照组和氢水组在冠状动脉左前降支阻断血流30 min后行再灌注24 h,造成心肌缺血再灌注损伤,氢水组再灌注5 min前以5 ml/kg腹腔注射氢水.对照组和氢水组再灌注24 h后检测左心室收缩压(LVSP)、左心室舒张压(LVDP)、左心室内压最大上升和下降速率[±(dP/dt) max]等心功能指标;用氯化三苯基四氮唑(TTC)染色观察心肌梗死面积,HE染色观察心肌损伤程度,并检测血浆和心肌中丙二醛(MDA)的表达以观察心肌氧化损伤程度,用TUNEL法检测心肌缺血区(area at risk,AAR)心肌细胞凋亡,分光光度法检测心肌凋亡酶caspase-3的表达,免疫组化检测心肌8-羟基鸟嘌呤(8-OHdG)的表达.假手术组在同时间点用相同方法观察或检测上述指标.结果 与对照组相比,氢水组心肌缺血再灌注损伤显著减轻,心肌组织病理性损伤减轻,脂质 和DNA过氧化损伤指标明显减低,心功能显著改善,心肌细胞凋亡减轻,caspase-3表达降低(氢水组0.278±0.092,对照组0.507±0.072),心肌梗死面积显著减少.结论 氢水可以有效减少心肌缺血再灌注损伤.