Why study transport of peptides and proteins at the neurovascular interface

The blood–brain barrier (BBB) is an immense neurovascular interface. In neurodegenerative, ischemic, and traumatic disorders of the central nervous system (CNS), the BBB may hinder the delivery of many therapeutic peptides and proteins to the brain and spinal cord. Fortunately, the mistaken dogma that peptides and proteins do not cross the BBB has been corrected during the past two decades by the accumulating evidence that peptides and proteins in the periphery exert potent effects in the CNS. Not only can peptides and proteins serve as carriers for selective therapeutic agents, but they themselves may directly cross the BBB after delivery into the bloodstream. Their passage may be mediated by simple diffusion or specific transport, both of which can be affected by interactions in the blood compartment (outside the BBB) and within the endothelial cells (at the BBB level). Although the majority of current delivery strategies focuses on modification of the molecule to be delivered, understanding the mechanisms of transport will eventually facilitate regulation of the BBB directly. We review the different aspects of interactions and discuss recent advances in the cell biology of peptide/protein transport across the BBB. Better understanding of the nature and regulation of the transport systems at the BBB will provide a new direction to enhance the interactions of peripheral peptides and proteins with the CNS.     

Postnatal formation of the blood-testis barrier in the rat with special reference to the initiation of meiosis

Summary Postnatal formation of the Blood-Testis Barrier (BTB) in the rat was studied by either fixation in hypertonic fixative or employing lanthanum tracer. After 15 days of age, meiosis has reached different stages of spermatogenesis in differnt zones of the seminiferous cords. Only in those parts where germ cells are in the pachytene stage of meiosis do Sertoli cells form an effective barrier or tight compartment. Between 16 and 19 days of age, final formation of the BTB, which is to be found in the adult rat testis, occurs by zygotene and then leptotene stages successively entering the tight compartment. Thus, formation of a BTB by Sertoli cells does not occur synchronously along the length of the seminiferous cord but in accordance with the stage of meiosis of the associated germ cells.     

Inflammatory central nervous system disease in lupus-prone MRL/lpr mice: comparative histologic and immunohistochemical findings

The brains of pathogen-free autoimmune MRL/lpr, NZBWF1 and NZB mice were examined for central nervous system (CNS) inflammation in premoribund 8-week-old animals and at ages when active systemic lupus erythematosus (SLE) was present. CNS inflammation was observed only in MRL/lpr mice. Immunohistochemical studies of brains from young MRL/lpr mice found that infiltrates were composed primarily of CD4+ cells. Older MRL/lpr mice (22 and 26 weeks of age) had CD4+ cells predominantly, but CD8+ and B220+ cells were also present. Perivascular leakage of IgG was a prominent and unexpected finding in the MRL/lpr model. Congenic MRL/+ mice with late-onset autoimmunity had no inflammatory cells in brain tissue, and there was no perivascular staining with IgG or albumin. Our findings suggest that MRL/lpr mice are a useful model for studies of lupus-associated CNS inflammatory disease, and perivascular leakage may be a primary mechanism for entry of IgG into the brain.     

重症急性胰腺炎时肠屏障破坏的机制及防治

众多因素参与了重症急性胰腺炎时肠屏障破坏的发生、发展，随之而来的菌群移位及内毒素血症又加重了肠屏障破坏，导致严重不良预后。本文综合了肠屏障受损的可能原因，同时针对发病原因提出了相应防治对策。     

参附注射液对大鼠胰腺移植受体小肠肠粘膜屏障的保护作用

目的探讨参附注射液（SF）对大鼠胰腺移植受体肠粘膜屏障的保护作用及机制。方法24只糖尿病大鼠随机分为缺血再灌注组（IR组。n=12），参附注射液预处理组（SF组．n=12），12只正常大鼠为对照组，IR组和SF组大鼠均接受胰腺移植，再灌注后5d检测小肠通透性和吸收功能，检测血清TNF-α、NO、SOD和淀粉酶活性，取受体空肠粘膜组织检测小肠粘膜粘膜湿重、微绒毛高度及宽度、MDA含量及MPO活性，同时取肠系膜静脉血、肠系膜淋巴结、肝及脾组织进行细菌培养，观察细菌易位情况。结果再灌注后SF组血清TNF—α含量（P〈0．01）、淀粉酶活性（P〈0．01）、MDA含量（P〈0．01）、MPO活性（P〈0．01）、小肠通透性（P〈0．01）、细菌易位率（P〈0．01）和小肠粘膜损伤程度均低于IR组；血清NO和SOD含量、小肠吸收功能均高于IR组（P〈0．01）。结论SF预处理可保护大鼠胰腺移植受体小肠肠粘膜屏障，降低细菌易位率，机制可能与降低胰酶活性、减少TNF—α生成、减轻PMNs粘附与聚集、增加NO和SOD含量有关。     

Assessment of anti-inflammatory activity of Poria cocos in sodium lauryl sulphate-induced irritant contact dermatitis

OBJECTIVE: In the present study, we evaluated the anti-inflammatory activity of Poria cocos (PoCo) on experimentally induced irritant contact dermatitis (ICD) in a repeated sodium lauryl sulphate (SLS) irritation model. METHODS: The anti-irritative effect of PoCo was evaluated with a visual score and quantified by non-invasive bioengineering methods, namely chromametry and transepidermal water loss. Three concentrations of PoCo in base cream DAC (amphiphilic emollient; German pharmacopoeia) were tested in a 4-day repetitive irritation test using SLS. RESULTS: A statistically significant anti-inflammatory activity was observed for PoCo by all three methods when applied in parallel to the induction period of ICD. Application of PoCo after induction of ICD once a day for 5 days, starting just at the end of 4 days, was without any effect. CONCLUSION: An anti-inflammatory efficacy of PoCo on the elicitation phase of the ICD induced by repeated SLS test could be observed and quantified by three independent, non-invasive biophysical assessment parameters. This effect can be explained by its influence on pro-inflammatory enzymes, namely phospholipase A2.     

造血干细胞移植后慢性移植物抗宿主病相关的膜性肾病一例

目的 总结造血干细胞移植后慢性移植物抗宿主病（cGVHD）相关的膜性肾病的诊疗体会。方法 为1例急性淋巴细胞白血病患者施行HLA全相合的无关供者外周血造血干细胞移植，术后应用甲氨喋呤和他克莫司（FK506）预防GVHD。术后第19d发生急性GVHD，经甲泼尼龙治疗逆转。分别于术后182d、235d停用FK506和泼尼松，5d后患者出现cGVHD表现，肝功能异常，并伴肾病综合征的相关表现，病理诊断为膜性肾病Ⅱ期，遂给予FK506和泼尼松治疗，同时辅以利尿、降脂等措施。结果发生膜性肾病时，患者的尿蛋白＋＋＋＋，白细胞75个／μl，上皮细胞359．5个／pl，病理性管型＋，管型计数为167个／μl，24h尿蛋白定量为4．28g；肾组织活检，无肾小球硬化，肾小球体积稍大，部分血管袢受压，开放欠佳，肾小球基底膜轻微增厚，外观呈僵硬感，系膜基质轻、中度增殖；间质区部分肾小管扩张，肿胀、变性，未见明显间质纤维化和炎症细胞浸润；Masson染色可见基底膜上皮侧嗜复红物沉积；免疫荧光检查，IgG＋＋＋，C3＋＋＋，IgA＋＋，沿毛细血管袢呈颗粒状节段性分布，系膜区呈团块状分布；IgM、Clq、CA均阴性。电镜下可见肾小球基底膜上皮下沉积物，并有基膜增厚，毛细血管系膜基质轻度增生。经泼尼松和FK506治疗，2个月后尿蛋白转阴。结论 造血干细胞移植后出现肾病综合征或蛋白尿，应考虑GVHD相关膜性肾病的可能，肾穿刺活检有助于诊断，糖皮质激素和FK506治疗有效。     

高血压脑出血患者血肿周围血-脑屏障葡萄糖转运蛋白1表达的研究

目的观察高血压脑出血(ICH)患者血肿周围血-脑屏障葡萄糖转运蛋白1(GLUT1)表达的变化。方法采用免疫组化方法检测28例高血压ICH患者不同病程血肿周围脑组织GLUT1的表达情况。结果与对照组相比,ICH组发病12 h GLUT1表达开始增强,24 h、48 h表达最强(均P<0.01);72 h表达明显下降(P<0.01)。结论ICH早期血肿周围GLUT1表达增多,有助于恢复脑的能量代谢。     

冰片开放血-脑脊液屏障对实验性细菌性脑膜炎治疗影响的研究

目的 探讨冰片开放血-脑脊液屏障（BCB）对实验性细菌性脑膜炎治疗的影响。方法 采用日本大耳白兔作为实验动物，随机分为对照组、冰片组和脑膜炎组。经枕大池注入肺炎球菌悬液建立脑膜炎模型，以冰片作为开放BCB的制剂。以连续静脉注射丙戊酸钠后不同时间点的脑脊液中丙戊酸钠浓度变化作为判断BCB通透性的指标；硝酸镧示踪法观察脑组织表现作为BCB通透性的形态指标。给予脑膜炎动物头孢吡肟或冰片＋头孢吡肟治疗，记录动物存亡情况；取脑脊液（CSF）进行细胞计数及生化检查。取脑组织作常规病理染色，以观察冰片开放BCB对实验性细菌性脑膜炎治疗的影响。结果 给药后对照组CSF中丙戊酸钠浓度基本保持稳定，冰片组CSF中丙戊酸钠浓度于给药后0．5h时即高于对照组并逐渐上升，至6h时达高峰，然后开始下降，14h时浓度仍高于对照组。脑组织超微结构显示，对照组无硝酸镧颗粒通过BCB，脑膜炎组硝酸镧颗粒分布于毛细血管基底膜外，冰片组弥漫性分布于神经细胞间隙和轴突周围。给予头孢吡肟治疗后，脑膜炎＋冰片组动物存活率（9／12，75％）明显高于脑膜炎组（6／18，66．7％）（P〈0．05），但两组间CSF细胞数及蛋白、葡萄糖水平差异无统计学意义。近皮层脑组织HE染色显示，脑膜炎组可见脑组织大量炎症细胞渗出和软化坏死灶,血管“套袖”现象明显，而脑膜炎＋冰片组脑组织内炎症细胞渗出较少，无血管“套袖”现象，无明显坏死软化灶。结论 冰片确实能明显增加BCB的通透性并具有可逆性特点，抗生素联合冰片能改善实验性细菌性脑膜炎治疗效果，为细菌性脑膜炎的治疗提供了新的思路。