Brachytherapy: An emblematic example of extreme hypofractionated regimen

In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.     

女性致密性骨炎血清骨转换生化标志物水平变化研究

背景 致密性骨炎（OCI）和其他疾病有时难以鉴别，探讨血清骨转换生化标志物可为OCI的鉴别诊断提供依据。 目的 探索女性OCI患者的血清骨转换生化标志物的水平变化及临床意义。 方法 回顾性选取2013年6月至2022年2月在北京积水潭医院门诊及住院诊断为OCI的61例女性患者作为观察组，年龄15~50岁，平均（33.8±6.6）岁，病程2周~15年。选择同期61例女性体检健康者作为对照组，年龄15~48岁，平均（35.6±7.6）岁。比较两组一般临床资料和血清骨转换生化标志物水平，并对血清骨转换生化标志物与病情相关指标进行相关性分析。 结果 观察组血清白蛋白（45.4±2.9）g/L低于对照组（46.5±2.8）g/L（t=2.190，P<0.05）。血清骨转换生化标志物比较结果显示，观察组血清1型胶原羧基末端肽β特殊序列（β-CTX）〔0.28（0.23，0.37）μg/L〕、N-端骨钙素（OC）〔13.1（11.2，16.2）μg/L〕、25-羟维生素D3〔25-（OH）VD3〕〔（14.1±5.1）μg/L〕低于对照组〔0.36（0.29，0.48）μg/L，15.6（13.7，17.3）μg/L，（17.5±6.6）μg/L〕（Z=-2.983、-3.255，t=3.081，P<0.05）。长病程亚组OC水平〔14.6（12.4，18.5）μg/L〕高于短病程亚组〔11.7（10.2，14.0）μg/L〕（Z=-2.407，P<0.05）。多孕亚组β-CTX〔0.25（0.22，0.32）μg/L〕、OC水平〔12.2（10.3，15.0）μg/L〕低于非多孕亚组〔0.33（0.26，0.44）μg/L、13.4（12.0，18.8）μg/L〕（Z=-2.486、-1.897，P<0.05）。相关性分析显示，观察组血清1型前胶原氨基端延长肽（tP1NP）与妊娠次数、生产次数均呈负相关（rs=-0.276、-0.298，P<0.05），OC与体质指数（BMI）、视觉模拟评分法（VAS）评分、妊娠次数均呈负相关（rs=-0.284、-0.374、-0.360，P<0.05），25-（OH）VD3水平与BMI呈正相关（rs=0.275，P<0.05）。 结论 女性OCI患者血清OC、β-CTX水平明显降低，可为鉴别其他疾病提供依据；血清OC水平可以反映OCI患者的严重程度，同时OC水平与患者妊娠次数相关；tP1NP与妊娠次数、生产次数相关。     

脑出血继发损伤中沉默信息调节因子2的表达和炎症反应*

目的：探讨脑出血对酵母沉默信息调节因子2（Sirt2）和炎症的影响。方法：将胶原酶Ⅳ注入SD大鼠右侧 纹状体中建立脑出血模型，通过免疫印迹和ELISA 等方法测定大鼠脑出血后48 h 的Sirt2 的表达及炎症变化。利 用Hemin 诱导PC12 细胞损伤模拟体外脑出血模型，并检测Sirt2 及炎症变化；采用短发夹RNA（shRNA）-Sirt2 沉 默Sirt2 在PC12 细胞中的表达及对炎症的影响。结果：手术后48 h 脑出血行为学评分最低。脑出血组Sirt2 的表达 显著高于假手术组。脑出血组IL-6、IL-1β 表达显著升高。结论：脑出血可以促进Sirt2 的表达和炎症反应，降低 Sirt2 的表达可减缓炎症反应。 关键词 脑出血；沉默信息调节     

Quantification of myocardial fibrosis using noninvasive T2-mapping magnetic resonance imaging: Preclinical models of aging and pressure overload

Noninvasive imaging of cardiac fibrosis is important for early diagnosis and intervention in chronic heart diseases. Here, we investigated whether noninvasive, contrast agent-free MRI T₂-mapping can quantify myocardial fibrosis in preclinical models of aging and pressure overload. Myocardial fibrosis and remodeling were analyzed in two animal models: (i) aging (15-month-old male CF-1 mice vs. young 6- to 8-week-old mice), and (ii) pressure overload (PO; by transverse aortic constriction in 4- to 5-month-old male C57BL/6 mice vs. sham-operated for 14 days). In vivo T₂-mapping was performed by acquiring data during the isovolumic and early diastolic phases, with a modified respiratory and ECG-triggered multiecho TurboRARE sequence on a 7-T MRI. Cine MRI provided cardiac morphology and function. A quantitative segmentation method was developed to analyze the in vivo T₂-maps of hearts at midventricle, apex, and basal regions. The cardiac fibrosis area was analyzed ex vivo by picro sirius red (PSR) staining. Both aged and pressure-overloaded hearts developed significant myocardial contractile dysfunction, cardiac hypertrophy, and interstitial fibrosis. The aged mice had two phenotypes, fibrotic and mild-fibrotic. Notably, the aged fibrotic subgroup and the PO mice showed a marked decrease in T₂ relaxation times (25.3 ± 0.6 in aged vs. 29.9 ± 0.7 ms in young mice, p = 0.002; and 24.3 ± 1.7 in PO vs. 28.7 ± 0.7 ms in shams, p = 0.05). However, no significant difference in T₂ was detected between the aged mild-fibrotic subgroup and the young mice. Accordingly, an inverse correlation between myocardial fibrosis percentage (FP) and T₂ relaxation time was derived (R² = 0.98): T₂ (ms) = 30.45 – 1.05 × FP. Thus, these results demonstrate a statistical agreement between T₂-map–quantified fibrosis and PSR staining in two different clinically relevant animal models. In conclusion, T₂-mapping MRI is a promising noninvasive contrast agent-free quantitative technique to characterize myocardial fibrosis.     

Resiniferatoxin reduces cardiac sympathetic nerve activation to exert a cardioprotective effect during myocardial infarction

Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive.     

脾脏血管性病变与淋巴瘤CT鉴别诊断

目的 运用CT区分脾脏血管性病变与淋巴瘤。方法 回顾性分析20例经手术、穿刺病理学检查证实的脾脏病变的发病年龄、性别、脾脏指数、病变大小、数目、有无液化、钙化、强化幅度、强化方式等特征,并进行统计学分析。结果 20例脾脏病变中,11例血管性病变(6例海绵状血管瘤,3例窦岸细胞血管瘤,2例硬化性血管瘤样结节性转化),9例淋巴瘤;两组间发病年龄、病变大小、数目、有无液化、钙化等差异无统计学意义;两组间脾脏指数、动脉期强化幅度差异具有统计学意义(P＜0.05)。5例海绵状血管瘤呈不均匀性强化,1例呈渐进性填充式强化,2例窦岸细胞血管瘤呈“雀斑征”,1例硬化性血管瘤样结节性转化呈“辐轮征”;9例淋巴瘤实质部分均呈均匀、轻中度强化。结论 脾脏血管性病变与淋巴瘤CT表现不同,CT有助于明确诊断。