Search results for " Scanning"
showing 10 items of 988 documents
Scanning electron microscopic evidence for neural differentiation in Ewing's sarcoma cell lines.
1990
A number of recent studies have suggested a relationship between Ewing's sarcoma (ES) and other small round cell tumours of childhood such as peripheral neuroepithelioma (PN). We report scanning electron microscopic studies on the character of induced neural differentiation in ES, neuroblastoma, PN, osteosarcoma and colon carcinoma. We found evidence of neural differentiation in both neural lines and in one of two Ewing's lines before treatment. After differentiation, both Ewing's and neural lines developed neuritic processes with varicosities and little arborization, except for the initially undifferentiated Ewing's line (A4573) which displayed extensive lateral sprouting from neuritic pro…
Scanning electron microscopy of the cervix uteri.
1974
Scanning electron microscopy has been used in the study of five cases of the cervix uteri: two normal cases; one case of indirect metaplasia; one case of carcinoma in situ whose colposcopic examination showed an erosio vera surrounded by leucoplasia, mosaic, base, and an area of atipic transformation zone and one case of invasive carcinoma.
S100α and S100β proteins in human cutaneous sensory corpuscles: Effects of nerve and spinal cord injury
1998
S100 protein in the vertebrate peripheral nervous system consists of homo- or heterodimers of S100α and S100β proteins, the first predominating in neurons and the second in glial cells. Recently, however, occurrence of S100β protein in neurons has been reported. The expression of S100 protein by Schwann cells, as well as their derivatives in sensory corpuscles, depends on the sensory axon (i.e., the Schwann cell–axon contact). The present study analyzed the distribution of S100α and S100β proteins in human cutaneous sensory corpuscles and the effects of peripheral or central sensory axon severance in the expression of these proteins. Simple or double immunohistochemistry was carried out usi…
Tumour-cell-endothelial interactions: free radicals are mediators of melanoma-induced endothelial cell damage
1996
Damage to vascular endothelium may play an important role during metastasis. We used a three-dimensional model of tumour cell extravasation to test the hypothesis that certain types of tumour cells are able to induce vascular endothelial cell injury. Multicellular tumour spheroids (MCTS) of 14 human cancer cell lines and spheroids from two benign cell lines were transferred onto confluent monolayers of human endothelial cells (EC). MCTS from 4 of 7 melanoma cell lines induced damage of the endothelium which was closely associated with tumour cell attachment. Endothelial cell injury became evident morphologically by loss of cell membrane integrity and sensitivity to shear stress. Similar res…
Barrier functions and paracellular integrity in human cell culture models of the proximal respiratory unit.
2009
International audience; Airway epithelial cells provide a barrier to the translocation of inhaled materials. Tight (TJ) and adherens junctions (AJ) play a key role in maintaining barrier functions, and are responsible for the selective transport of various substances through the paracellular pathway. In this study we compared a bronchial cell line (16HBE14o-) and primary bronchial cells (HBEC), both cocultivated with the fibroblast cell line Wi-38, with respect to their structural differentiation and their reaction to cytokine stimulation. HBEC formed a pseudostratified epithelial layer and expressed TJ and AJ proteins after 2 weeks in coculture. Mucus-producing and ciliated cells were foun…
The intraclonal and interclonal phenotypic heterogeneity in a rhabdomyosarcoma cell line with abortive imitation of embryonic myogenesis
1988
Three distinct subpopulations (A, B, C) derived from a dimethylbenzanthracene-induced rat rhabdomyosarcoma were established as permanent cell lines. Although the clonal nature of each of these subpopulations was confirmed by repeated recloning procedures, a striking intraclonal phenotypic heterogeneity was observed. By means of immunofluorescence microscopy and transmission electron microscopy, it could be shown that these subpopulations closely recapitulate stages of embryonic rhabdomyogenesis both in vitro and in vivo, but differ in their particular range of maximum differentiation. Embryonic rhabdomyogenesis is imitated most perfectly by subpopulation C, in which multinuclear myotubes ar…
Acute Morphological and Toxicological Effects in a Human Bronchial Coculture Model after Sulfur Mustard Exposure
2009
International audience; Sulfur mustard (SM) is a strong alkylating agent. Inhalation of SM causes acute lung injury accompanied by severe disruption of the airway barrier. In our study, we tested the acute effects after mustard exposure in an in vitro coculture bronchial model of the proximal barrier. To achieve this, we seeded normal human bronchial epithelial explant-outgrowth cells (HBEC) together with lung fibroblasts as a bilayer on filter plates and exposed the bronchial model after 31 days of differentiation to various concentrations of SM (30, 100, 300, and 500mM). The HBEC formed confluent layers, expressing functional tight junctions as measured by transepithelial electrical resis…
Importance of iron and aluminium in rapid and slow combustion of peat
1990
Abstract The effects of Fe and Al on peat combustion and the formation of nitrogen oxides were studied under conditions of rapid combustion in an entrained flow reactor, and under conditions of slow combustion in a thermobalance and a differential scanning calorimeter. Iron had a strong catalytic effect on both the slow and rapid combustion, and it decreased the ratio of N2O to NO in the combustion gases. A decrease in the content of inorganic compounds decreased reactivity, probably because of the decrease in iron content. Aluminium did not have a detectable catalytic effect on the combustion rate but it depressed the formation of nitrogen oxides slightly. The chemical treatment to increas…
Peri-implantitis-like medication-related osteonecrosis of the jaw: Clinical considerations and histological evaluation with confocal laser scanning m…
2021
Objective: In the recent years, an increasing number of peri-implant medication-related osteonecrosis of the jaw (PI-MRONJ) have been reported in literature, both in oncologic and osteoporotic patients. The aim of this study is to describe 19 cases of patients previously diagnosed as affected by peri-implantitis, who were treated for PI-MRONJ, with consideration on clinical and histopathological features. Materials and Methods: Patients included were affected by postmenopausal osteoporosis and were administered with different antiresorptive drugs. Due to the presence of clinical and radiological signs of peri-implantitis not healed after non-surgical periodontal treatment, they were referre…
The structure and phase transition of tris(n-propylammonium) enneachlorodiantimonate (III),
1996
The crystal structure of at 298 K has been determined (monoclinic, space group Cc, a = 19.464(2) ?, b = 17.736(2) ?, c = 8.116(2) ?, , Z = 4). The structure consists of one-dimensional polyanionic chains extended along the c-axis, and n-propylammonium cations located in elongated cavities formed by polyanions. The cations are connected to chlorine atoms by hydrogen bonds. Differential scanning calorimetry, the temperature dependence of the lattice parameters and static electric permittivity studies revealed a first-order phase transition at K of an `order - disorder' type. It is related to the ordering of n-propylammonium cations that occurs on decreasing the temperature. Debye-like dispers…