Bronchopulmonary Dysplasia: A Correlative Study by Light, Scanning, and Transmission Electron Microscopy

The sequential stages of bronchopulmonary dysplasia occurring in 18 infants after intensive respiratory therapy supplemented by oxygen in high concentrations were studied by correlative light, scanning, and transmission electron microscopy. Infant survival ranged from 3 to 225 days. The earliest stage was an exudative reaction with a predominance of hyaline membranes. This merged with a subacute reparative response that was replaced by a chronic fibroproliferative stage in infants of longest survival; this stage was complicated by pulmonary fibrosis and emphysema. Correlative scanning and transmission electron microscopy demonstrated that type 2 pneumocytes contributed significantly to the reparative fibroproliferative response by organization of hyaline membranes and reepithelialization of damaged septal walls.     

A micro cell culture method utilizing modified microscope slides for use in fluorescent antibody and enzyme immunoassays

Summary A technique for culturing small quantities of mammalian cells on modified microscope slides is described. The modified microscope slides were Bellco Glass, Inc., toxoplasmosis slides and the cell cultures used were early passage bovine embryonic lung cells and continuous cell lines of porcine and canine origins. The slide cell cultures were either uninfected or infected with selected viruses or the obligate intracellular protozoanEncephalitozoon caniculi for utilization in direct and indirect fluorescent antibody testing or in peroxidase antiperoxidase immunosorbant assays.     

大鼠三叉神经脊束间质核内内脏神经初级传入终末与NOS阳性投射神经元的联系

目的　探查间质核 (INV)内内脏传入终末与向臂旁核 (PBN)投射的NOS阳性神经元之间的联系。　方法　逆行、跨神经节追踪以及免疫荧光组织化学方法 ,结合激光共聚焦扫描显微镜观察。　结果　PBN内注射四甲基罗丹明 (TMR)后 ,逆行标记细胞主要位于注射侧的INV ,大多属 2 0 μm以下的中、小型细胞。NOS阳性细胞与TMR逆行标记细胞分布区域重叠。NOS TMR双标记细胞分别占NOS阳性细胞总数的 5 4 8% (17 31)和TMR逆行标记细胞总数的 34% (17 4 9)。舌咽和迷走神经内注射生物素化葡聚糖胺 (BDA)跨神经节标记的内脏神经初级传入终末点状膨体贴近双标记细胞胞体 ,呈紧密接触状。　结论　可能存在经INV向PBN投射的内脏伤害性信息传导通路 ,作为神经递质和神经信息分子的NO可能参与其内脏伤害性信息的传递和调控     

Ultrastructural Changes in Small Intestinal Lipofibroblasts of Suckling Rabbits with Experimental Cholera

Ultrastructural analysis of the jejunum in suckling rabbits showed that lipofibroblasts localized in the submucosa and adjacent to crypts contain lipid inclusions (granules) with typical "melting" surface. Lipofibroblasts contained moderately widened cisternae of the granular endoplasmic reticulum and few mitochondria with dense matrix and poorly developed cristae. Experimental cholera was usually accompanied by a decrease in the number of lipid inclusions, and only in some cases by accumulation of lipid material. Our results suggest that the material accumulated in granules plays a role in the pathogenesis of cholera.     

Blood Flow and Leukocyte Adhesiveness Are Reduced in the Microcirculation of a Peritoneal Disseminated Colon Carcinoma

Dynamic behavior of leukocytes in the microcirculation of solid tumor tissue was visualized using a fluorescent labeling technique combined with the use of a real-time confocal laser-scanning microscope (CLSM) system. Colon tumor cells (RCN-9) were inoculated into the peritoneal cavity of male Fischer 344 rats. Tumor-free rats were similarly injected with physiological saline (intraperitoneally). Ten days after tumor inoculation, the mesentery was exteriorized and subjected to vital microscopic observation under the CLSM system. Leukocytes were labeled with rhodamine 6G (100 g kg^–1, intravenously), and their behavior within the microvessels (10–30 m in diameter) was analyzed both in the solid tumor tissues and the normal mesentery. Wall shear rate was calculated from the measured values of vessel diameter and erythrocyte flow velocity. In tumor microvasculature of tumor-bearing rats, the centerline erythrocyte velocity (0.73 ± 0.58 mm s^–1, mean±standard deviation) and wall shear rate (210 ± 151 s^–1 were significantly lower than those of the tumor-free rats (1.27 ± 0.83 mm s^–, 344 ± 236 s^–1, respectively). Despite such reduced flow conditions, flux of the rolling leukocytes as well as density of the adhered leukocytes both decreased significantly in tumor microvasculature as compared with normal controls. The methods developed in this work show promise in improving our understanding of tumor biology and pathophysiology. © 1998 Biomedical Engineering Society. PAC98: 8722Fy, 8745Hw, 8745Ft, 8764-t, 4262Be     

Ordering behaviors and age-hardening in experimental AuCu-Zn pseudobinary alloys for dental applications

Age-hardening mechanisms and related ordering behaviors of the experimental (AuCu)_1−xZn_x alloys with x0.2 were investigated for dental applications. The addition of Zn to equiatomic AuCu greatly increased the age-hardening rate and delayed overaging. It was suggested that the quenched-in excess vacancies were greatly related to the age-hardening rate in the AuCu–Zn pseudobinary alloys. In these alloys, the hardness became maximum during the very initial stage of ordering, and with the development of ordered phase, the hardness began to decrease. Transmission electron microscopy revealed that the age-hardening of AuCu–Zn pseudobinary alloys is caused by lattice distortion that occurred during the very early stage of atomic ordering. The addition of Zn to AuCu effectively increased the density of antiphase boundaries per unit volume of the AuCu II superstructure. This is suggested to be the main cause for the retardation of the overaging in the alloys containing Zn of 5 at% or more. This pronounced effect of Zn addition to AuCu alloy on its age-hardening characteristics may be advantageous for obtaining stable mechanical properties of dental casting gold alloys.     

Ultrastructural changes in hepatocytes of precision-cut rat liver slices after incubation for 24 and 48 hours

Hepatocytes of precision-cut rat liver slices were studied by means of transmission electron microscopy after long-term incubation (24–48 h) in comparison with freshly prepared slices, indicating reversible and irreversible intracellular alterations of the cells. After 24 h incubation the morphological image in transversal sections of slices is characterised by a central zone of damaged and necrotic cells flanked by two to several superficial layers of viable cells. This is typical of a diffusion gradient of oxygen tension and nutrient content from the surface to the centre of the slices. In adapted cells on the surface of the slices we observed an organelle-free layer of fine granular material in the apical cytoplasm followed by parallel oriented stacks of rough endoplasmic reticulum near by. Mitochondria of essentially normal appearance in adapted cells did not contain flocculent densities, which were observed in damaged cells only. The cytoplasm of parenchymal cells consisted of defined areas of clear cytoplasmic material containing numerous branching tubular profiles of smooth endoplasmic reticulum, presumably in the regions with depleted glycogen aggregates. Subcellular signs of necrosis are destroyed mitochondria, dilated endoplasmic reticulum free of ribosomes and clumping of chromatin in the nucleus of hepatocytes. No appreciable differences of the cell organelles were observed between 24 and 48 h of incubation, but the incidence and intensity of signs of necrosis increased with the duration of incubation and the thickness of the slices. The process of these changes may reflect the phenomenon of cellular adaptation and of hypoxic cellular injury in the periphery and the centre of the slices, respectively.     

Understanding the microbiome of diabetic foot osteomyelitis: insights from molecular and microscopic approaches

Objectives

Rigorous visual evidence on whether or not biofilms are involved in diabetic foot osteomyelitis (DFO) is lacking. We employed a suite of molecular and microscopic approaches to investigate the microbiome, and phenotypic state of microorganisms involved in DFO.

大鼠孤束核内5-HT能纤维和终末与向臂旁核投射的NOS阳性神经元的联系

应用四甲基罗达明逆行标记和免疫荧光技术相结合 ,在激光扫描共聚焦显微镜下对大鼠孤束核内 5 -HT能纤维和终末与向臂旁核投射的 NOS阳性神经元之间的联系进行了观察。将四甲基罗达明注入一侧外侧臂旁核后可见孤束核尾段背内侧、胶质、小细胞、内侧、中间内侧等亚核和连合亚核内出现较多的逆标神经元 ,四甲基罗达明逆标和 NOS阳性神经元以及 5 -HT阳性终末重叠分布 ,其中四甲基罗达明和 NOS双重阳性神经元分别占四甲基罗达明逆标和 NOS阳性神经元总数的 8.3% ( 14 /16 8)和 18.4% ( 14 /76 )。在此 5 -HT样阳性纤维和终末包绕着 NOS阳性神经元、四甲基罗达明逆标神经元及四甲基罗达明和一氧化氮合酶双重阳性神经元的胞体和树突 ,形成点状紧密接触。本研究结果提示 ,孤束核内来自下行性抑制系统的 5 -HT能纤维和终末可能与向臂旁核投射的 NOS阳性神经元形成突触联系 ,从而可对 NOS阳性神经元所传递的包括伤害性信息在内的内脏感觉传入信息发挥抑制性调控作用