Dermoscopic features distinctive for extraocular sebaceous carcinoma

We examined dermoscopic features of three cases of extraocular sebaceous carcinoma and reviewed the literatures. The yellowish structures, polymorphous vessels and ulceration were common findings in our cases and all cases of the previous reports. The appearance of whitish‐pink areas has not been described previously. Our results suggested that the combination of four dermoscopic features, whitish‐pink areas, yellowish structures, polymorphous vessels and ulceration might be distinctive in extraocular sebaceous carcinoma.     

Evidence for an alternative mechanism of human platelet secretion involving peripheralization of secretory granules and formation of membrane-associated multivesicular structures

Stimulated platelets release the content of their granules to the environment by a process known as platelet secretion. The precise mechanism of platelet secretion is poorly understood. The most widely-held theory suggests that, during platelet activation, secretory granules centralize and their content is released into the surface-connected canalicular system. Using fixation techniques directed at preserving membrane structures, morphological evidence is provided that human platelet activation is associated with secretory granules migrating to the periphery of platelets, where they undergo transition to participate in the formation of membrane-associated multivesicular structures. These multivesicular structures then undergo dissolution resulting in granule content secretion to the environment. The formation of the membrane-associated multivesicular structures occurs in platelets in which some of the secretory granules have also become centralized. This suggests that during the activation of human platelets, membrane-associated multivesicular structure release may occur concurrently with other mechanisms of secretory granule content release. The present observations are consistent, however, with the hypothesis that during human platelet activation the formation of membrane-associated multivesicular structures by platelet secretory granules contributes importantly to the mechanism of platelet secretion.     

鞍隔孔区解剖学研究及其临床意义

目的 通过鞍隔孔区结构的解剖学研究,分析经蝶入路脑脊液漏的发生机制,以及空蝶鞍(ES)的形成原因. 方法 对8例胎儿标本进行组织学连续切片后,做HE和Masson染色,并在显微镜下对鞍隔孔附近结构进行观察;另取10例成人尸头标本,模拟经蝶入路手术,并在手术显微镜下观察鞍隔孔区解剖结构. 结果 鞍上蛛网膜在垂体柄上端和其表面的软脑膜紧密结合,并转折进入鞍内;同时在垂体上表面处,鞍隔从四周紧密包绕并和表面的软脑膜紧密结合,而难以从组织学切片上分辨二者的界限:鞍上蛛网膜池由于蛛网膜、软脑膜和鞍隔的束缚而终止于鞍隔孔上部. 结论 鞍隔、软脑膜和鞍上蛛网膜三者之间存在着严密的解剖学关系,其也是防止脑脊液漏和ES发生的关键因素.这三者的先天性缺损、生理性或者病理性破坏,尤其是在经蝶入路中对垂体腺瘤的过分牵拉,导致鞍上蛛网膜和软脑膜分离或者破裂,可能是造成术中脑脊液漏发生的重要原因;另外鞍隔、软脑膜和垂体上表面之间的分离也可能是造成ES的关键因素.     

赤芍总苷、川芎总酚酸组分组成结构对缺氧损伤人脐静脉内皮细胞的影响

目的: 研究赤芍总苷、川芎总酚酸组分不同组成结构对连二亚硫酸钠(Na₂S₂O₄)诱导的人脐静脉内皮细胞(HUVEC)缺氧损伤模型的保护作用,并参照基线等比增减法,设计不同组分组成结构,优化出最佳的组分结构。 方法: 采用 Na₂S₂O₄ 体外诱导HUVEC,建立细胞损伤模型。采用MTT比色法测定细胞活力,试剂盒测定细胞内超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量、乳酸脱氢酶(LDH)含量、一氧化氮(NO)含量,通过Western blot检测了各组细胞Bcl-2,Bax蛋白的表达量。 结果: 与模型组比较,赤芍总苷组分、川芎总酚酸组分不同组成结构可显著提高SOD活力,降低MDA,LDH,NO含量 (P<0.01,P<0.05)。芍芎组分可以下调Bax蛋白的表达量,上调Bcl-2蛋白的表达量,Bcl-2/Bax显著升高(P<0.01,P<0.05),抑制细胞凋亡。结果显示赤芍总苷、川芎总酚酸组分组成结构比例为8:2时,对缺氧损伤的内皮细胞保护作用最好。 结论: 芍芎组分可以减轻HUVEC的缺氧损伤,8:2组分组成时保护作用最为明显,其机制可能与其抗氧化和抑制细胞凋亡 有关。     

Proteins of the retinoblastoma pathway,FEN1 and MGMT are novel potential prognostic biomarkers in pancreatic adenocarcinoma

Background

We studied the expression of some major proteins involved in cell-cycle regulation and DNA repair, the roles of which are not well known in pancreatic ductal adenocarcinoma (PDAC), but which have a significant impact on carcinogenesis of many other cancers.

虚拟中国人足底韧带结构失效后的足弓负荷机制研究

目的　建立虚拟中国人的足内侧纵弓与外侧纵弓的有限元模型,研究跖腱膜松解术或足底韧带损伤后足骨与内在肌群的生物力学特性,探讨骨性结构、足底韧带、足底腱膜、足底固有肌群之间的协调作用机制。方法　采用虚拟中国人“女性1号”CT图像和MRI图像;采用非线性有限元方法进行足弓术后或韧带损伤后的平衡直立负荷状态仿真;并应用足底固有肌群的3种被动张力（微弱、适度、强烈）模拟术后或韧带损伤后的肌肉状态。结果　建立了虚拟中国人“女性1号”足内侧纵弓第2跖列与外侧纵弓第5跖列的生物力学有限元模型,计算得到内侧纵弓和外侧纵弓在平衡直立时,韧带损伤时,固有肌群活动时的张应力矢量图、压应力矢量图和von Mises应力整体分布数据。结论　跖腱膜松解术和足底韧带损伤等增加了足纵弓von Mises应力峰值,改变了张应力与压应力的流向;而足底固有肌活动的被动张力能降低足纵弓von Mises应力集中程度,调节张应力、压应力矢量接近平衡状态,减小了并发骨折和腱炎的危险性。骨性结构、韧带、腱膜、固有肌群的内在应力具有定量的相互调节功能。     

Efficiency of different decalcification protocols for nasal osseous structures in a rat experimental model of allergic rhinitis,and their effects on epithelial histology: An attempt at standardization

IntroductionDecalcification of osseous specimens is required for histological analysis; this however may cause tissue damage. In rodent models of allergic rhinitis (AR), epithelial histologic assessment necessitates prior decalcification of the nasal osseous structures. However, respiratory epithelium is highly susceptible to damage, and rat nasal architecture is elaborate and its sectioning is challenging. Nevertheless, decalcification is not standardized in experimental AR. We therefore undertook this task, in order to reduce experimental bias.MethodsSix-to-eight week-old Wistar rats underwent an AR protocol. Subsequently, nasal structures were decalcified in the following mediums: (i) formic acid 10% for 5 and 20 days; (ii) formic acid 15% for 5 and 15 days; (iii) Morse Solution for 5 and 20 days and (iv) EDTA for 20 and 40 days. Decalcification efficiency/speed was evaluated via radiographic analysis. Furthermore, specimens were stained with hematoxylin and eosin and assessed for preservation of epithelial features.ResultsSpecimens were appropriately decalcified in 5 days in the formic acid-based mediums and in 20 days in EDTA with minimal epithelial damage. EDTA for 40 days had no unacceptable adverse effects; conversely, 15 and/or 20 days in acid-based agents provided no extra benefit for decalcification and were detrimental to the epithelium.ConclusionsEDTA treatment for 20 days is appropriate for decalcification of nasal structures in rat models of allergic rhinitis; further incubation preserves epithelial integrity but is not required. When urgency is a factor, formic-acid-based decalcification for 5 days yields acceptable results.