Rapid induction of 7H6 tight junction-associated protein and paracellular barrier function in capillary endothelial cells of porcine brain in vitro by treatment with astrocyte conditioned medium and cAMP

The capillary endothelium of the central nervous system functions as a highly selective permeability barrier, corresponding to the blood-brain barrier (BBB). In the present study, we assessed the roles of the tight junction-associated proteins ZO-1 and 7H6 in the development of brain endothelial barrier function. Capillary endothelial cells (ECs) of porcine brain were cultured and treated with a combination of astrocyte conditioned medium (CM), 8-(4-chlorophenylthio) cyclic AMP (cAMP), and phosphodiesterase inhibitor. Barrier function induced within 10h was more than 10 fold higher in terms of transendothelial electrical resistance (TER) and permeability to inulin and mannitol. Concomitantly, 7H6 antigen was significantly induced at the cell border, but the expression of ZO-1 did not change significantly between the control and treated cells. These results showed the importance of astrocyte CM and cAMP for the induction of the BBB and suggested that astrocyte CM and cAMP may function differently in the induction of 7H6 antigen in brain capillary ECs.     

猪肠静脉回流阻断模型肠屏障的变化

目的 评价肠静脉回流阻断肠淤血时肠屏障的变化。方法 采用种群相近的猪8只，无感染症状。分离门静脉和肝后下腔静脉分别阻断、然后开放各50min，分别观察动脉血压、心率、血气分析、手术中肠颜色及形态变化。在各时间点取回肠末端小肠全层，行光镜及电镜检查，测定肠丙二醛(MDA)含量及门、颈静脉血内毒素含量。结果8只猪一般情况无差别。阻断后，肠淤血、水肿，并随时间延长而加重。光镜下阻断前基本正常，实验结束时绒毛、腺体均有损伤。电镜下阻断前细胞形态基本正常，阻断后细胞超微结构轻微异常。阻断前后的肠MDA含量、血内毒素含量无显著性差异。结论 肠静脉回流阻断引起的肠道淤血可导致肠粘膜屏障损伤。在50min内肠淤血性的损伤不会引起肠腔内内毒素的大量移位。     

Intestinal permeability in children: variation with age and reliability in the diagnosis of cow''s milk allergy

Objective: To analyse to what extent age may alter intestinal permeability (IP) in children and to assess its reliability according to clinical manifestations in cow's milk allergy (CMA). Design:     

Cerebral peritumoral oedema study: Does a single dynamic MR sequence assessing perfusion and permeability can help to differentiate glioblastoma from metastasis?

Our purpose was to differentiate glioblastoma from metastasis using a single dynamic MR sequence to assess perfusion and permeability parameters. 24 patients with glioblastoma or cerebral metastasis with peritumoral oedema were recruited and explored with a 3T MR unit. Post processing used DPTools software. Regions of interest were drawn around contrast enhancement to assess relative cerebral blood volume and permeability parameters. Around the contrast enhancement Glioblastoma present high rCBV with modification of the permeability, metastasis present slight modified rCBV without modification of permeability. In conclusion, peritumoral T2 hypersignal exploration associating morphological MR and functional MR parameters can help to differentiate cerebral metastasis from glioblastoma.     

Perfusion CT cerebral blood volume and permeability surface in low and high grades of brain glioma

Purpose

To study if glioma grade could be correlated with perfusion CT parameters; permeability surface (PS) and cerebral blood volume (CBV) and if high-grade glioma would show different parameter levels as compared with low-grade glioma.

Patients and methods

Perfusion CT (PCT) was conducted for 40 patients with untreated glioma using 64 multidetector-row CT scanner. Perfusion maps of PS and CBV were generated, and these parameters were measured. World Health Organization (WHO) glioma grades were compared with PCT parameters.

Results

The 40 patients were classified as low-grade glioma group (18 patients) and high-grade glioma group (22patients). There was highly significant difference (P < 0.001) between the two groups as regard the mean values of CBV& PS in tumor sides where they were higher in the high-grade glioma group. Receiver operating characteristic (ROC) analyses showed that PS (AUC 0.818) is better than CBV (AUC 0.788) in differentiating low- and high-grade glioma and so PS had higher predictability than CBV regarding glioma grading.

Conclusion

Changes in PS and CBV values had good correlation with glioma grading; with PS was the best parameter correlating with glioma grade. High grade glioma showed higher PS and CBV levels as compared with low-grade glioma.     

氮酮对碱性成纤维细胞生长因子眼内通透性的影响

背景 研究证实,碱性成纤维细胞生长因子(bFGF)在视网膜前体细胞的增生分化过程中发挥重要作用,但因其眼内通透性低而限制了其在临床上的应用.探寻增加bFGF眼内通透性的有效途径无疑对视网膜疾病的治疗有重要意义. 目的 观察氮酮对bFGF滴眼液眼内通透性的影响,探索眼部无创给药途径,为bFGF滴眼液用于眼内疾病的治疗提供依据.方法 以随机数字表法将18只新西兰白兔随机分成4个组,其中体积分数0.4％氮酮+体积分数5％ bFGF组9只兔并按照取材时间的不同亚分为3个组(30、60、120 min),其他3个组各3只兔.不同组兔眼分别局部点用蒸馏水(空白对照组)、5％ bFGF滴眼液(5％bFGF组)、0.4％氮酮+5％ bFGF滴眼液(0.4％氮酮+5％ bFGF组)和0.4％氮酮+10％ bFGF滴眼液(0.4％氮酮+10％ bFGF组),每5分钟1次,共3次,于点眼后30 min抽取房水和玻璃体,其中0.4％氮酮+5％ bFGF组于点眼后30、60和120 min抽取房水和玻璃体,用ELISA法测定房水和玻璃体中bFGF的吸光度(A450)值. 结果 5％ bFGF组兔眼房水和玻璃体中bFGF的A值分别为0.1007±0.0100和0.1340±0.0100,与空白对照组(分别为0.1363±0.0100和0.1130±0.0100)比较影响并不确切.0.4％氮酮+5％ bFGF组及0.4％氮酮+10％ bFGF组兔眼房水和玻璃体中bFGF的A450值均明显高于5％bFGF组,差异均有统计学意义(均P=0.000),但0.4％氮酮+5％ bFGF组与0.4％氮酮+10％ bFGF组房水及玻璃体中bFGF含量的差异均无统计学意义(P=0.985、0.098).0.4％氮酮+5％ bFGF组点眼后30、60和120 min房水中bFGF的A450值以30 min时最高,为0.9413±0.0300,60 min时为0.3865±0.0300,120 min时为0.2550±0.0300,房水中bFGF的A450值随着时间的延长逐渐降低( R2=0.736,P=0.003),而玻璃体中bFGF的A450值与时间之间无明显线性关系(R2=0.196,P=0.233). 结论 氮酮可以改善bFGF滴眼液的眼内通透性,bFGF的体积分数从5％增加到10％时不能有效提高bFGF点眼后的利用度.0.4％氮酮+5％ bFGF滴眼液点眼后30 min房水中bFGF含量最高,随时间延长bFGF的含量逐渐降低.     

热打击对人骨骼肌细胞通透性、细胞骨架及细胞周期的影响

目的 研究热打击对培养人骨骼肌细胞(HSKMC)通透性、细胞骨架及细胞周期影响.方法 流式细胞仪钙离子内流检测热打击对HSKMC细胞膜通透性的影响,考马斯亮蓝R-250染色法检测热打击对HSKMC细胞骨架影响,流式细胞仪检测热打击对HSKMC细胞周期改变.结果 给予培养人HSKMC细胞不同温度梯度热打击1h后,43℃热打击组钙离子流式检测的中位数为91.63,37℃对照组中位数为22.98.同对照组相比,随着热打击程度加强,显微镜高倍镜下可见骨骼肌细胞骨架逐渐出现变粗、变短、出现明显的应力纤维.骨骼肌细胞在热打击情况下,各组G0/G1期DNA含量在44.13～62.98之间,与正常对照组对比,当细胞离开热打击环境后培养18 h前G0/G1期DNA含量明显高于对照组,培养第18小时恢复才同对照组基本相同.结论 热打击的情况下造成细胞钙离子内流效应,导致细胞内钙超载.可改变HSKMC骨架结构,使骨架失去正常的网状有序排列结构,间隙增大.细胞周期出现阻滞,细胞被阻滞在G0/G1期.     

Prolactin effects on cultured pavement cell epithelia and pavement cell plus mitochondria-rich cell epithelia from freshwater rainbow trout gills

The physiological effects of ovine prolactin (oPRL) and recombinant rainbow trout prolactin (rbtPRL) on cultured gill epithelia derived from freshwater rainbow trout were assessed. Epithelia composed of either pavement cells only (single seeded inserts, SSI) or both pavement and mitochondria-rich cells (double seeded inserts, DSI) were cultured in media, supplemented with doses of oPRL ranging from 10 to 100 ng/ml. Under symmetrical culture conditions (L15 media apical/L15 media basolateral), oPRL had no effect on transepithelial resistance, paracellular permeability (assessed with PEG-4000), or Na(+) and Cl(-) transport across both preparations of cultured gill epithelia. Under asymmetrical conditions (freshwater apical/L15 media basolateral), SSI epithelia treated with oPRL (10 and 50 ng/ml), in comparison to comparably treated epithelia receiving no oPRL, exhibited a greater increase in the transepithelial resistance, particularly during the first 12h of freshwater exposure, no difference in paracellular permeability and Na(+)-K(+)-ATPase activity, and lowered net Na(+) flux rates (i.e., reduced basolateral to apical loss rates). These reflected reduced unidirectional efflux rates. The PRL effect appeared to be mainly a reduction in transcellular permeability. SSI epithelia treated with rbtPRL (10 ng/ml) exhibited similar patterns of response to those treated with oPRL. Na(+)-K(+)-ATPase activity increased in DSI epithelia treated with oPRL; however, oPRL did not stimulate ion uptake across either SSI or DSI epithelial preparations. The data demonstrated that, as the sole hormone supplement for cultured gill epithelia, PRL did not promote active ion uptake. However, the observed PRL-induced alterations in cultured gill epithelial physiology were consistent with the in vivo actions of PRL on the gills of freshwater teleost fish.     

Non-electrolyte permeability of deoxygenated sickle cells compared

The passive permeability pathways of red cells are poorly defined, with the exception of the Gardos channel. Several cation and anion pathways can be induced by a variety of manoeuvres, however, including treatment with oxidants, low ionic strength (LIS), shrinkage, swelling and also infection with the intra-erythrocytic malaria parasite. Several of these stimuli (malaria, swelling, LIS), in addition, also activate a non-electrolyte this permeability. Sickle cells uniquely show a deoxygenation-induced pathway, which is termed P_sickle and is usually considered to be a conductive cationic pathway. In this report, we explore further the extent to which this permeability pathway of deoxygenated sickle cells is available for non-electrolyte transport. We show that a number of solutes are permeable, with greater permeability to sugars (notably lactose and maltose) and smaller molecules, and less to charged or zwitterionic species. Red cells from heterozygous HbSC patients also showed deoxygenation-induced haemolysis in isosmotic sucrose solution, though to a slightly lesser extent than for red cells from homozygous sickle cell patients. In contrast to sickle cells, red cells from β-thalassaemic patients did not show haemolysis in isosmotic sucrose solutions, regardless of the O₂ tension. Of the secondary cellular changes resulting from incubation in non-electrolyte solutions (which include imposition of a highly positive membrane potential, marked intracellular alkalinisation and cell shrinkage), none appear to correlate with activation of the non-electrolyte permeability. Rather, findings indicate that it is low ionic strength per se that is responsible. Normal red cells also show changes in ionic and non-electrolyte permeability in low ionic strength media, and these permeabilities are compared to those found in deoxygenated sickle cells. The extent to which these different permeabilities in normal and sickle red cells can be ascribed to one or more common pathways remains to be determined.     

Influence of Mast Cells on the Expression of Adhesion Molecules on Circulating and Migrating Leukocytes in Acute Pancreatitis-Associated Lung Injury

Pancreatitis-associated lung injury is an early-occurring and severe complication, still associated with substantial mortality. A number of inflammatory cells and their products are involved in the initiation and progress of the condition. In the present study, acute pancreatitis (AP) was induced by the intraductal infusion of 5% sodium taurodeoxycholate in the rat. Pulmonary endothelial barrier dysfunction was measured by plasma exudation of radiolabeled albumin. Expression of PECAM-1, ICAM-1, and L-selectin on neutrophils (CD11b⁺) and monocytes/macrophages (CD11b/c⁺), obtained from circulation and lung tissue, was measured 1 and 6 hours after AP induction (n = 10 rats/time point/group). Plasma levels of histamine and serotonin were determined. The role of mast cells was evaluated by pretreatment with the mast cell stabilizer cromolyn. Intraperitoneal administration of cromolyn downregulated pancreatitis-induced systemic increase of histamine at 1 hour (513 ± 82 vs. 309 ± 50, p < 0.05). Cromolyn prevented a decreased expression of PECAM-1 on circulatory neutrophils and monocytes/macrophages and against an increased expression of ICAM-1 and PECAM-1 on pulmonary neutrophils and monocytes/macrophages 6 hours after AP induction (about 40% vs. 10%, p < 0.01). The mast cell stabilizer also prevented pancreatitis-induced pulmonary endothelial barrier dysfunction at 6 hours. Thus, our data indicate that mast cells may play a critical role in the activation of leukocytes during the initiation of pancreatitis-associated lung injury by altering phenotypes of adhesion molecules.