骨髓间充质干细胞分化为皮肤附属器细胞的初步实验研究

目的探讨骨髓间充质干细胞(marrowmesenchymalstemcells,MSCs)分化为创面皮肤附属器细胞的可能性,及其参与创面修复的可能机制。方法无菌条件下取Wistar大鼠股骨骨髓细胞,密度梯度离心分离、纯化MSCs,体外培养扩增后,用BrdU标记细胞。另于同种雄性Wistar大鼠背部正中,制备1cm×1cm全厚皮肤缺损创面模型,将BrdU标记的1×106/mlMSCs从阴茎静脉输注,术后第3天与第7天切取创面组织,行BrdU免疫组织化学单染色,以及BrdU和广谱角蛋白免疫组织化学双染色。结果BrdU阳性细胞出现在创面皮下组织、皮脂腺、毛囊和骨髓腔中。免疫组织化学双染色结果显示,皮脂腺和毛囊有BrdU阳性细胞,同时表达广谱角蛋白。结论创面愈合过程中,MSCs归巢并参与创面修复;在实验性全身皮肤缺损创面微环境下,MSCs可分化为皮肤附属器细胞。     

Bacterial flagella explore microscale hummocks and hollows to increase adhesion

Biofilms, surface-bound communities of microbes, are economically and medically important due to their pathogenic and obstructive properties. Among the numerous strategies to prevent bacterial adhesion and subsequent biofilm formation, surface topography was recently proposed as a highly nonspecific method that does not rely on small-molecule antibacterial compounds, which promote resistance. Here, we provide a detailed investigation of how the introduction of submicrometer crevices to a surface affects attachment of Escherichia coli. These crevices reduce substrate surface area available to the cell body but increase overall surface area. We have found that, during the first 2 h, adhesion to topographic surfaces is significantly reduced compared with flat controls, but this behavior abruptly reverses to significantly increased adhesion at longer exposures. We show that this reversal coincides with bacterially induced wetting transitions and that flagellar filaments aid in adhesion to these wetted topographic surfaces. We demonstrate that flagella are able to reach into crevices, access additional surface area, and produce a dense, fibrous network. Mutants lacking flagella show comparatively reduced adhesion. By varying substrate crevice sizes, we determine the conditions under which having flagella is most advantageous for adhesion. These findings strongly indicate that, in addition to their role in swimming motility, flagella are involved in attachment and can furthermore act as structural elements, enabling bacteria to overcome unfavorable surface topographies. This work contributes insights for the future design of antifouling surfaces and for improved understanding of bacterial behavior in native, structured environments.     

瘢痕疙瘩中皮肤附件结构破坏与瘢痕增生的关系

目的　探讨瘢痕疙瘩 (keloid K)形成过程中皮肤附件 (skin appendages,SAs)结构破坏与瘢痕增生的关系。　方法　将来自 17例 K患者的活检标本按浸润生长 (K- I,n=9)、瘢痕增生 (K- P,n=17)、瘢痕萎缩 (K- A,n=10 )和边缘正常皮肤 (K- N,n=6 )进行分组 ,另以非 K患者胸部正常皮肤 (NS,n=6 )为对照 ,采用免疫组织化学方法观察SAs密度与广谱细胞角蛋白 (pan- fytokeratin,CKp)、CK19、腺上皮分泌成分 (secretory component,SC)和增殖细胞核抗原 (proliferating cell nuclearantigen,PCNA) ,以及凋亡相关蛋白 Bcl- 2和 Bax之间的变化规律 ,同时用组织学、解剖显微镜及扫描电镜观察 K胶原纤维和 SAs结构的组织形态学改变。　结果　与 K- N和 NS组相比 ,K组织中 CKp和 SC阳性的 SAs密度迅速减少 ,可见 SAs结构消失后残留 CKp阳性蛋白痕迹 ;多数 SAs上皮细胞 Bax表达增强 ,但 Bcl- 2、PC-NA和 CK19阳性的 SAs则呈现复层 (鳞状 )上皮化和形态结构异常。 K组织形态学大致经历浸润、增殖和成熟的过程 ,SAs也相应地发生增生 ,细胞迁移、炎性反应和血管闭塞等引起的形态结构破坏和几乎被纤维结缔组织完全取代的变化过程。直线相关分析显示 ,K的瘢痕厚度与 SAs密度之间呈显著的负相关 (r=- 0 .341,P<0 .0 1)。　结论     

Morphological aspects of asynchronous secretion of pancreatic cells

An electron-microscopic study of the pancreas of several vertebrates showed that asynchronous secretion of the pancreatic cells is controlled by means of cytoplasmic cell appendages that determine the selective access of primary materials to the gland cells. The outflow of hormones and other metabolites from the intercellular spaces into the pericapillary space is also controlled in the pancreas by means of cytoplasmic appendages.Department of Histology and Embryology, Faculty of Internal Medicine, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 1, pp. 84–86, January, 1976.     

ES细胞源性表皮干细胞与类真皮构建组织工程皮肤的体内分化

目的以ES细胞源性表皮干细胞为种子细胞与类真皮构建组织工程皮肤,探讨其在体内的分化。方法胎鼠皮肤成纤维细胞和大鼠骨髓基质干细胞(BMSCs),分别与复合凝胶-明胶海绵构建类真皮(类真皮Ⅰ、Ⅱ),植入小鼠全层皮肤缺损创面,以生物膜为载体,把羊膜诱导后带有核标记的表皮干细胞覆盖在类真皮上,术后1～8周连续取材,苏木精-伊红染色,β1整合素、CK15、CK19、CK10和CEA免疫荧光双标和免疫组化观察。结果两组组织工程皮肤植入皮肤缺损3～4周后,创面完全长合,较厚新生皮完全覆盖创面,基底层细胞增生,形成短的细胞柱突向真皮层。新生表皮中可见核标记的细胞呈β1整合素、CK15、CK19阳性,真皮中的管腔样结构呈核荧光和CEA免疫组化双标阳性,4～8周新生表皮基底层细胞呈CK19、CK10阳性,新生表皮下可见毛囊样、皮脂腺样结构。结论ES细胞源性表皮干细胞为种子细胞与类真皮构建的两种组织工程皮肤在体内具有修复缺损皮肤及分化为表皮及毛囊样、皮脂腺样和汗腺样等皮肤附属结构的潜能。     

New concepts on the histogenesis of eccrine neoplasia from keratin expression in the normal eccrine gland, syringoma and poroma

Background  Peripheral and luminal layers of eccrine sweat gland ducts are self-renewing structures. Proliferation is restricted to the lowermost luminal layer, but randomly scattered in the peripheral layer. Each layer exhibits differential expression of keratins K5/K14 and K6/K16. Keratin K1 occurs only in peripheral cells and the novel keratin K77 is specific for luminal cells.
Objectives  To investigate the expression of luminal (K77), peripheral (K1) and further discriminatory keratins in two eccrine sweat gland tumours: syringoma, thought to show differentiation towards luminal cells of intraepidermal sweat ducts and eccrine poroma, considered to arise from poroid cells, i.e. peripheral duct cells; and keratinocytes of the lower acrosyringium/sweat duct ridge differentiating towards cells of intradermal/intraepidermal duct segments.
Methods  Paraffin-embedded sections were examined by immunohistochemistry using several keratin, smooth muscle actin and Ki-67 antibodies.
Results  We confirmed the ductal nature of syringomas. Despite drastic morphological alterations in both layers, their keratin patterns remained almost undisturbed compared with normal ducts. In eccrine poroma epidermal keratins K5/K14 were ubiquitously expressed in all poroid cells. Cell islands deviating morphologically from poroid cells contained epidermal keratins K1/K10. K77 expression was limited to luminal cells of intact duct structures within the tumours.
Conclusions  Syringomas are benign tumours of luminal cells of the lowermost intraglandular sweat duct. Poroid precursor cells of poromas do not comprise peripheral duct cells nor do poromas differentiate towards peripheral or luminal duct cells. Instead, poroid cells consist only of keratinocytes of the lowermost acrosyringium and the sweat duct ridge and poromas tend to differentiate towards the cells of the upper acrosyringium.     

214份药品不良反应报告表调查分析

目的：探讨药品不良反应的发生特点及规律,为临床合理用药提供参考.方法：对我院2003-2004年药品不良反应报告表用SPSS 12.0进行统计分析.结果：214份药品不良反应报告中,涉及药品167种,不良反应231例次.引起不良反应最常见的药物为抗感染药,共45种（73例次）,其次为中药29种（50例次）和循环系统药19种（27例次）.所累及的器官以皮肤及附件（149例次）最为常见,神经系统损害（57例次）居第2位.转归较好.结论：提示临床要严格掌握适应证,合理用药,并加强合理用药监测,尽量减少和避免不良反应的发生,保证药物治疗安全有效.