Differentiation of proton-pumping activity in cultured renal inner medullary collecting duct cells

Cultured inner medullary collecting duct (IMCD) cells have been shown to secrete protons (H⁺) by two mechanisms: anN-ethylmaleimide-and dicyclohexyl-carbodiimide-sensitive electrogenic H⁺-ATPase or H⁺ pump, and an amiloride-sensitive, secondary active Na⁺/H⁺ exchanger. These cells also express Cl^–/HCO₃ ^– exchange and carbonic anhydrase activity in common with other renal epithelial cells involved in acid-base transport. Video fluorescence microscopy of individual cells using 2, 7-biscarboxyethyl-5(6)-carboxyfluorescein has demonstrated that adjacent-cultured IMCD cells show substantial functional intercellular heterogeneity. The development of H⁺-pumping activity is associated with high-baseline intracellular pH and peanut agglutinin (PNA) affinity, and loss of mitotic activity and of Na⁺/H⁺ exchange. The H⁺-pumping activity may be further enhanced by removal of fetal calf serum for 6–54 h or by selecting cells with high PNA affinity. IMCD cells in their most differentiated state form domes, which consistently showed the highest rates of H⁺-pumping activity, as well as high affinity for peanut lectin. When IMCD were plated at low density, domes developed relatively late (2–4 weeks), at which time cells located in the center of nests of contiguously growing cells were quiescent and showed H⁺-pumping activity but no Na⁺/H⁺ exchange. On the other hand, dense plating was associated with early development of domes (end of 1st week), at which time adjacent cells showed a high mitotic activity and Na⁺/H⁺ exchange, but no H⁺-pumping activity. We speculate that differentiation of IMCD cells results in the development of cell polarity. This could include either loss of the apical Na⁺/H⁺-exchange activity, or localization of this exchanger only to the basolateral membrane, while the H⁺ pump differentiates at the apical membrane.     

The Effects of Permeation Enhancers on the Surface Morphology of the Rat Nasal Mucosa: A Scanning Electron Microscopy Study

A rat model has been developed to compare relative morphological changes in the nasal mucosa after exposure to potential membrane permeation enhancers. Scanning electron microscopy was used to characterize gross structural and specific cellular changes following exposure. Micrographs of the rat nasal mucosa were scored in four categories: (1) mucosal surface integrity, (2) ciliary morphology, (3) mucus/extracellular debris, and (4) presence of red blood cells. The order of increasing morphological damage resulting from a 5-min exposure to each surfactant was 0.5% Solulan C-24 0.5% Solulan C-24/0.5% sodium tauro-24,25-dihydrofusidate (STDHF) < 0.5% STDHF < 1.0% STDHF 1.0% Laureth-9 < 1.0% sodium taurodeoxycholate 1.0% sodium deoxycholate. The changes observed in the mucosal morphology after exposure to the various surfactants are in general agreement with data in the literature. This model is able to compare rapidly the relative morphological effects on the mucosal membrane of different nasal formulations.     

脑白质疏松的病理与影像学关系的研究

目的：研究脑白质疏松确切的病理变化及其与影像学（CT／MRI）的关系。方法：将10年来我科收治的63例影像学表现为脑白质疏松的患者的临床及影像学资料进行总结,其中10例死后进行了病理检查。结果：脑室周围深部白质,半卵圆中心,放射冠部位的病理学表现为：（1）髓鞘结构紊乱,体积变小,数量减少;（2）轴索变性,萎缩和脱失,（3）白质内明显的小血管硬化和胶质细胞增生;（4）多发性腔隙性梗死灶。结论：病理证实的脱髓鞘改变,CT显示的脑室周围低密度性改变,MRI的T2加权像显示的双侧弥漫性高信号三者部位一致。     

实验性急性胰腺炎大鼠胰岛微血管的电镜观察

目的 :了解实验性急性胰腺炎大鼠早期胰岛微血管的超微结构变化 ,并探讨其与急性胰腺炎的关系。方法 :采用皮下注射超大剂量雨蛙素诱发大鼠急性水肿性胰腺炎 ,用扫描电镜和透射电镜观察急性胰腺炎早期胰岛微血管的形态和变化。结果 :①在透射电镜下 ,胰岛毛细血管内皮细胞肿胀 ,管腔狭窄、不规则 ,内皮细胞“窗孔”数量增加。②在扫描电镜下 ,胰岛毛细血管外形不规则 ,与外分泌部毛细血管之间的吻合明显减少 ;毛细血管表面可见铸型剂形成的泡状物。结论 :急性胰腺炎早期即有胰岛微血管损伤的表现 ,推测其与胰腺炎的进展密切相关。     

骶管内囊肿24例的影像学诊断和临床特点

目的：探讨骶管内蛛网膜囊肿的影像学和临床特点,以助于临床诊断,方法：观察24例经手术证实的骶管内蛛网膜囊肿患的X线片,CT,造影后CT,MRI等影像学资料中的影像改变,分析该组患的临床表现特点及手术中的病理特点,结果：X线片,CT,及MRI中均可显示出骶骨的骨性改变,造影后CT囊肿内造影剂显影,MRI可以清楚的显示出囊肿呈长T1及T2信号,信号强度与脑脊液一致,临床症状以骶管内神经受压表现为主,囊肿与硬膜囊一般有交通孔,结论：MRI是最好的影像学诊断方法;骶管内蛛网膜囊肿的发生是由于先天的硬膜缺损所致。     

外伤后细菌性致死性肉芽肿的透射电镜观察

目的：外伤后细菌性致死性肉芽肿是一种尚未被认识的新疾病,近20a来在我国多个地区已发现20余例,无一存活。本研究 应用透射电镜寻找病原体,为该病的诊断和治疗提供线索。方法：以透射电镜观察2例外伤后细菌性致死性肉芽肿的活检组织,寻找该病的病原。结果：病变组织内主要为组织细胞、多核巨细胞,细胞内有大量溶酶体样结构,部分溶酶体样结构具有“杆菌”形态,另见少数球菌。根据电镜下的发现成功分离出1种严格的厌氧性细菌,初步确定为放线菌,并根据细菌药敏结果救活了1例患。结论：对于怀疑由病原体所致的疾患,电镜下发现损害中的病原体是最具说服力的证据,本病的发现和命名,电镜发挥了关键作用。     

B19病毒对先天性心脏病先天感染的探证及电镜观察

目的 证实部分先天性心脏病（CHD）患者心肌组织中微小病毒B19系先天感染所致,并观察CHD心肌组织超微结构变化。方法 采用ELISA,PCR,原位杂交（ISH）及透射电镜等技术,对42例CHD患者及对照组22例风湿性心瓣膜病患者的外周血,活检心肌组织分别进行B19－VP2－Ig M,B19-DNA的检测,并用透射电镜对心肌细胞的超微结构进行观察。结果（1）CHD组中B19－VP2－IgM阳性3例（7％）,对照组中阳性1例（5％）,两组间无显著差异（P＞0．05）,（2）CHD组中B19－DNA阳性8例（19％）,与对照组均阴性相比有显著性差异（P＜0．01）,且与8例心肌B19－DNA阳性标本配对的血中B19－VP2－IgM的均阴性。（3）ISH显示B19DNA定位于心肌细胞核内,电镜超微结构观察细胞胞质,核内均未见23nm病毒样颗粒,也无细胞器的损害。结论 B19病毒对先天性心脏病的感染系先天性感染所致,病毒基因可能整合于宿主细胞核内。     

自旋回波结合电影MRI在先天性心脏病诊断的初步应用

目的　探讨常规自旋回波 (SE)结合电影MRI对先天性心脏大血管畸形的诊断价值。方法　先天性心脏病患者 2 1例 ,其中Fallot四联症 1 4例 ,房间隔缺损 2例 ,右室双出口 2例 ,单心室 1例 ,主动脉缩窄 2例。所有患者接受MRI检查 ,先做不同层面的SET1 WI,再选择最佳层面做电影MRI。分析MRI检查结果 ,并与超声心动图、心血管造影和手术结果对照。结果　SET1 WI可显示心脏大血管的主要结构畸形 ,电影MRI可进一步明确心血管结构畸形及血液流动改变 ,MRI检查结果与心血管造影及手术结果基本一致。结论　常规SE结合电影MRI能准确显示心脏大血管畸形 ,尤其适用于婴幼儿先天性心脏病的检查。