胰腺癌伴神经浸润动物模型的建立

目的 建立胰腺癌伴神经浸润的动物模型.方法 32只裸鼠分为4组,每组8只.将人胰腺癌细胞SW1990、CAPAN-2、PANC1分别注射于裸鼠的坐骨神经周围,以不做任何处理的裸鼠作为对照组.观察术后裸鼠体质量变化、成瘤情况、成瘤时间、造模成功率等指标.结果 对照组裸鼠体质量增加,各癌细胞注射组裸鼠成瘤后体质量明显下降,甚至呈现恶液质,成瘤侧肢体活动受限.CAPAN-2注射组及SW1990注射组的8只裸鼠最终均成瘤,PANC1注射组只有5只成瘤.以肿瘤最长径长至约0.8 cm为时间截点,CAPAN-2注射组、PANC1注射组、SW1990注射组裸鼠的成瘤时间分别为（49.8±5.0）、（56.6±2.4）、（25.4±3.0）d.SW1990注射组成瘤时间最短,PANC1注射组成瘤时间最长,3组间成瘤时间的差异具有统计学意义（F=73.51,P＜0.01）.CAPAN-2注射组、PANC1注射组、SW1990注射组裸鼠神经浸润造模成功率分别为87.5％ （7/8）、20.0％（1/5）、50.0％ （4/8）.结论 成功建立了胰腺癌伴神经浸润动物模型,但不同的胰腺癌细胞系建立的动物模型具有不同的特点.     

Healthcare impact of COVID-19 epidemic in India: A stochastic mathematical model

BackgroundIn India, the SARS-CoV-2 COVID-19 epidemic has grown to 1251 cases and 32 deaths as on 30 Mar 2020. The healthcare impact of the epidemic in India was studied using a stochastic mathematical model.MethodsA compartmental SEIR model was developed, in which the flow of individuals through compartments is modeled using a set of differential equations. Different scenarios were modeled with 1000 runs of Monte Carlo simulation each using MATLAB. Hospitalization, intensive care unit (ICU) requirements, and deaths were modeled on SimVoi software. The impact of nonpharmacological interventions (NPIs) including social distancing and lockdown on checking the epidemic was estimated.ResultsUninterrupted epidemic in India would have resulted in more than 364 million cases and 1.56 million deaths with peak by mid-July. As per the model, at current growth rate of 1.15, India is likely to reach approximately 3 million cases by 25 May, implying 125,455 (±18,034) hospitalizations, 26,130 (±3298) ICU admissions, and 13,447 (±1819) deaths. This would overwhelm India's healthcare system. The model shows that with immediate institution of NPIs, the epidemic might still be checked by mid-April 2020. It would then result in 241,974 (±33,735) total infections, 10,214 (±1649) hospitalizations, 2121 (±334) ICU admissions, and 1081 (±169) deaths.ConclusionAt the current growth rate of epidemic, India's healthcare resources will be overwhelmed by the end of May. With the immediate institution of NPIs, total cases, hospitalizations, ICU requirements, and deaths can be reduced by almost 90%.     

VEGF在SD大鼠Walker-256肝转移瘤模型建立中的应用

 目的：探讨采用血管内皮细胞生长因子（VEGF）缩短SD大鼠Walker-256肝转移瘤成模时间的安全性与可行性,为抗VEGF靶向药物的研究提供更实用的模型。方法：将SD大鼠随机分为3组,每组各15只。生理盐水（NS）模型组：于建模前1周开始尾静脉注射生理盐水0.1 mL/d; 20 mg/L VEGF模型组：于建模前1周开始尾静脉注射20 mg/L VEGF（0.1 mL/d）; 40 mg/L VEGF模型组于建模前1周开始尾静脉注射40 mg/L　VEGF（0.1 mL/d）。各组均注射至建模当天。建模方法：暴露大鼠肝脏,将瘤块种植于肝包膜下。分别于建模后3 d、1周和2周用磁共振成像（MRI）观察肿瘤生长情况,并记存活时间。结果：建模成功,肝内肿块HE染色符合恶性肿瘤特点。大鼠肝脏MRI表现：肿块呈结节状,T2WI呈稍高信号,显示更为清楚,腹水于T2WI呈高信号。NS模型组和20 mg/L VEGF模型组各有1只动物于建模后1 d死亡,40 mg/L VEGF模型组有3只于建模1周后死亡。建模后3 d各组可观察到肿块的大鼠数分别为：NS模型组0只,20 mg/L VEGF模型组7只,40 mg/L VEGF模型组10只;建模后1周各组可观察到肿块的大鼠数分别为：NS模型组3只,20 mg/L VEGF模型组14只,40 mg/L VEGF模型组13只;建模后2周各组可观察到肿块的大鼠数分别为：NS模型组12只,20 mg/L VEGF模型组14只,40 mg/L VEGF模型组10只。20 mg/L VEGF模型组和40 mg/L VEGF模型组分别与NS模型组相比,3 d可观察到成瘤的老鼠数目差异均有统计学意义（P<0.05）。NS模型组与20 mg/L VEGF模型组大鼠存活时间差异无统计学意义（P＞0.05）,40 mg/L VEGF模型组存活时间短于NS模型组（P<0.01）。结论:20 mg/L VEGF能缩短SD大鼠肝转移瘤成模时间,对其存活时间无显著影响,且相较于传统模型,更适合应用于抗VEGF靶向药物的研究。     

人胰腺癌PANC-1细胞裸鼠移植瘤模型建立及其用于观察载siRNA纳米微粒体内效应的研究

 目的：探讨建立人胰腺癌PANC-1裸鼠移植瘤模型的最佳实验方法,并应用该模型进行载基因纳米微粒体内效应的研究。方法：将不同数量PANC-1细胞悬液接种于BALB/c (nu/nu)小鼠右侧背部皮下,当肿瘤体积达100 mm3时尾静脉注射siRNACY5.5纳米复合物进行活体荧光成像。此外,于尾静脉注射负载siRNAKras纳米复合物,蛋白印迹及免疫组织化学染色法观察肿瘤组织Kras蛋白表达水平。结果：1×107 cells/300 μL 接种成瘤率达100%,成瘤时间＜2周。荧光呈像及组织学检查显示载siRNA纳米微粒可靶向聚集在肿瘤组织发挥体内基因沉默效应。结论:本研究报道的人胰腺癌裸鼠移植瘤模型建立方法成瘤率达100%,成瘤时间短,是研究药物示踪和观察疗效的理想模型。     

Enhancing Student Learning of Removable Prosthodontics Using the Latest Advancements in Virtual 3D Modeling

When educating dental students or prosthodontic residents, a picture can be worth a thousand words. If that is so, then what could enhanced 3D modeling be worth relative to enhancing student learning? The answer is undoubtedly more than what a picture can provide. That is why the use of 3D models has become increasingly common with respect to patient care. The 3D modeling allows the patient to visualize more clearly the proposed treatments and outcomes; however, while 3D modeling has started to make an appearance in dental education, many of the current 3D modeling techniques do not offer the flexibility needed for dental education and enhanced student learning. At the University of Iowa, the use of 3D modeling software has enabled the creation of 3D models that can be altered or customized to be used in a more flexible way to teach students in the arts and complexities of removable partial denture (RPD) design and associated components. This educational technique article will: (1) demonstrate how these 3D models can be used to enhance student perception and learning regarding RPDs; and (2) will demonstrate using videos and web‐based portals to show how the 3D RPD models were created and then used for educational purposes.     

翻转课堂在牙体牙髓病学临床前期实习中的应用

翻转课堂是一种新的教学模式,是医学教育改革的新方向。本文介绍了翻转课堂的起源、特点,在国内医学教育中应用的现状,现阶段牙体牙髓病学临床前期实习教学中存在的问题。探讨了如何在牙体牙髓病学临床前期实习中构建翻转课堂教学模式,以及应用这一新的教学模式所面临的挑战。     

病原学阴性初治肺结核患者诊断模型的建立及初步评价

目的 建立病原学阴性初治肺结核患者的诊断模型, 以提高临床诊断的规范性及准确性。方法 收集 2017 年 8 月至 2019 年7 月湖南省胸科医院收治的年龄≥15岁、结核分枝杆菌病原学检查阴性, 且从未因结核病应用过抗结核药物治疗或不规范化疗未满1个月已确诊的200例病原学阴性初治肺结核患者和212例非结核性肺部疾病患者的临床资料。采用简单随机数字表法将两组患者分为两类, 一类为训练样本, 一类为考核样本, 两类样本比例为3∶1。通过对训练样本临床观察指标进行单因素和多因素非条件logistic回归分析, 筛选出独立预测因子并建立诊断模型, 并以训练样本的临床诊断结果为金标准, 采用受试者工作特征(ROC)曲线评估模型的诊断能力, 再使用考核样本对建立的诊断模型进行前瞻性考核。结果 对训练样本临床观察指标的多因素非条件logistic回归分析显示, 血清白蛋白/球蛋白比值(A/G)> 1.2、血清糖类抗原-125(CA-125)> 35kU/L、全血结核分枝杆菌γ-干扰素释放试验(IGRA)阳性、咳嗽≥2周、有咯血或者痰中带血、全身结核中毒症状、并发其他疾病、病灶发生于单侧或两侧的肺上叶尖后段和(或)下叶背段和空洞形成是病原学阴性初治肺结核与非结核性肺部疾病鉴别的相关独立因素[Wald χ ²= 7.264, P= 0.007, OR(95%CI)= 3.433(1.400~8.417); Wald χ ²= 17.114, P= 0.000, OR(95%CI)= 6.980(2.780~17.524); Wald χ ²= 63.643, P= 0.000, OR(95%CI)= 19.283(9.320~39.894); Wald χ ²= 5.557, P= 0.018, OR(95%CI)= 0.434(0.217~0.869); Wald χ ²= 6.237, P= 0.013, OR(95%CI)= 0.255(0.087~0.745); Wald χ ²= 24.930, P= 0.000, OR(95%CI)= 0.126(0.056~0.284); Wald χ ²= 12.062, P= 0.001, OR(95%CI)= 10.139(2.743~37.746); Wald χ ²= 16.224, P= 0.000, OR(95%CI)= 4.428(2.147~9.135); Wald χ ²=16.228, P=0.000, OR(95%CI)=14.437(3.939~52.919)]。ROC曲线分析模型的诊断效能为曲线下面积(AUC)=0.881(95%CI:0.839~0.915), 最佳临界值为0.42, 诊断病原学阴性初治肺结核的敏感度和特异度分别为86.67%和76.10%。经考核样本检验, 建立的诊断模型对两组患者总的准确判别率为79.61%(82/103)。结论 本研究建立的模型敏感度和准确率均较高, 可以作为临床医师诊断病原学阴性初治肺结核的辅助参考工具。     

Exploring the relationship between cognitive illness representations and poor emotional health and their combined association with diabetes self-care. A systematic review with meta-analysis

Objective

Depression and anxiety are common in diabetes and are associated with lower diabetes self-care adherence. How this occurs is unclear. Our systematic review explored the relationship between cognitive illness representations and poor emotional health and their combined association with diabetes self-care.

Methods

Medline, Psycinfo, EMBASE, and CINAHL were searched from inception to June 2013. Data on associations between cognitive illness representations, poor emotional health, and diabetes self-care were extracted. Random effects meta-analysis was used to test the relationship between cognitive illness representations and poor emotional health. Their combined effect on diabetes self-care was narratively evaluated.

Results

Nine cross-sectional studies were included. Increased timeline cyclical, consequences, and seriousness beliefs were associated with poorer emotional health symptoms. Lower perceived personal control was associated with increased depression and anxiety, but not mixed anxiety and depressive symptoms. Remaining cognitive illness representation domains had mixed statistically significant and non-significant relationships across emotional states or were measured only once. Effect sizes ranged from small to large (r = ± 0.20 to 0.51). Two studies explored the combined effects of cognitions and emotions on diabetes self-care. Both showed that cognitive illness representations have an independent effect on diabetes self-care, but only one study found that depression has an independent effect also.

Conclusions

Associations between cognitive illness representations and poor emotional health were in the expected direction — negative diabetes perceptions were associated with poorer emotional health. Few studies examined the relative effects of cognitions and emotions on diabetes self-care. Longitudinal studies are needed to clarify directional pathways.     

雷公藤多苷对胶原诱导性关节炎大鼠表皮生长因子受体家族表达的影响

目的 观察表皮生长因子受体(EGFR)家族成员EGFR、ErbB-2在胶原诱导性关节炎(CIA)大鼠滑膜及软骨中的表达及雷公藤多苷(TWP)对其影响,探讨EGFR、ErbB-2在CIA大鼠发病中的,作用及TWP治疗RA的药理作用机制.方法 建立CIA大鼠模型,分别采用免疫组织化学染色及实时定量聚合酶链反应( PCR)检测EGFR、ErbB-2在滑膜和软骨中的表达.统计学处理采用单因素方差分析.结果 EGFR、ErbB-2的蛋白表达及mRNA水平在CIA模型组滑膜(EGFR 0.268±0.059,ErbB-2 0.25±0.04.EGFR mRNA:14.2±0.55,ErbB-2 mRNA 23.46±3.64)和软骨(EGFR 0.193±0.018,ErbB-2 0.217±0.033,EGFR mRNA:4.16±0.50,ErbB-2 mRNA 9.23±0.66)中明显高于正常组(P＜0.01),在治疗组中表达低于模型组(P＜0.01).结论 初步证明EGFR、ErbB-2参与了CIA的病理过程.TWP治疗RA的机制可能与其降低EGFR、ErbB-2的表达有关.     

犬迷走神经性心房颤动模型的建立

目的制作犬迷走神经性心房颤动模型,评价可行性和持续性。方法针状电极分别插入颈部双侧迷走神经干,以3V-5V的电压/10Hz-20Hz的频率,刺激双侧迷走神经,在心率出现明显下降后,给予频率为10Hz-20Hz,电压为3V-5V的快速脉冲起搏刺激右心房,诱发心房颤动。结果迷走神经刺激的平均电压/频率为4.4V±0.7V/16.8Hz±3.3Hz,心率由基础的(171±26)次/分降为(97±8)次/分;在给予平均电压/频率为3.5V±0.6V/11.5Hz±2.2Hz的右心房起搏刺激后,36只杂种犬中31只(86.1%)成功诱发出持续性心房颤动,且在保持迷走神经刺激下,持续时间超过90分钟。结论本实验建立的犬迷走神经性心房颤动模型容易诱发,持续时间长,为评估抗心率失常药物对心房颤动的作用提供可靠的方法。