Scanning microscopy最新文献_第7页

Cytoskeletal changes during radiation-induced neoplastic transformation of human prostate epithelial cells. 放射诱导的人前列腺上皮细胞肿瘤转化过程中细胞骨架的变化。

Scanning microscopy Pub Date : 1996-01-01

S C Prasad, P J Thraves, A Dritschilo, J S Rhim, M R Kuettel

{"title":"Cytoskeletal changes during radiation-induced neoplastic transformation of human prostate epithelial cells.","authors":"S C Prasad, P J Thraves, A Dritschilo, J S Rhim, M R Kuettel","doi":"","DOIUrl":"","url":null,"abstract":"We recently reported tumorigenic transformation of SV40-immortalized neonatal human prostate epithelial cells (267B1) by exposure to fractionated doses of X-rays. Altered morphology and anchorage independence were observed following two successive fractions of 2 Gy each (F3-SAC). Additional 2 Gy treatments to these non-tumorigenic cells to a total dose of 30 Gy resulted in radiation-transformed tumorigenic colonies (267B1-SXR). Malignant transformation of parental 267B1 cells was also achieved by consecutive 2 Gy exposures to a total dose of 30 Gy (267B1-XR). This study discusses the cytoskeletal changes in the F3-SAC, 267B1-XR and 267B1-SXR derivatives of these human prostate epithelial cells. Confocal and conventional fluorescence microscopy of filamentous actin showed numerous, well organized, evenly distributed stress fibers in the parental cells prior to irradiation, while the anchorage-independent cells and several tumorigenic derivatives exhibited poor stress fiber organization after radiation exposure. This disorganization of actin microfilaments in the radiation-transformed cells was also accompanied by changes in the expression of selective tropomyosin isoforms as judged by two-dimensional gel electrophoresis. These changes in actin organization and tropomyosin expression appear to be coincidental with morphological transformation and acquisition of tumorigenicity in the 267B1 cells following radiation exposure.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 4","pages":"1093-102; discussion 1102-4"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20763027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Contribution of conventional and high resolution scanning electron microscopy and cryofracture technique to the study of cerebellar synaptic junctions. 常规和高分辨率扫描电镜及低温骨折技术对小脑突触连接研究的贡献。

Scanning microscopy Pub Date : 1996-01-01

O J Castejón

{"title":"Contribution of conventional and high resolution scanning electron microscopy and cryofracture technique to the study of cerebellar synaptic junctions.","authors":"O J Castejón","doi":"","DOIUrl":"","url":null,"abstract":"The cerebelli of teleost fishes, primates and humans were processed for conventional and high resolution scanning electron microscopy (SEM) to study the outer and inner surfaces of axo-dendritic, glomerular and axosomatic synapses. The cryofracture technique, either by slow or fast freezing, exposed the hidden neuronal surfaces of synaptic connections, selectively removing the glial ensheathment. Axo-dendritic junctions of climbing fibers and Golgi axonal ramifications were studied in gold-palladium and chromium coated samples. Chromium coating showed different mass density and topographic contrast between axonal and dendritic profiles. Conventional SEM of cryofractured glomerular synapses exhibited the outer surface view of en passant mossy fibers glomeruli, in which granule cell dendrites appear surrounding the afferent mossy fibers. The cryo-fracture method also exposed the axosomatic contacts of basket axonal collaterals upon the Purkinje cell somatic surface and the climbing fiber bulbous endings upon tertiary Purkinje dendrites. Field emission high resolution SEM of parallel fiber-Purkinje cell dendritic spines showed the inner organization of pre-synaptic endings and the three-dimensional structure of the synaptic membrane complex. The spheroidal synaptic vesicles appeared embedded in a homogeneous axoplasmic substance. Round subunits, 15-20 nm in diameter, were observed as intrinsic components of the post-synaptic membrane and associated with the post-synaptic density. High resolution SEM offers SE-I images comparable in resolution to thin section electron microscopy and freeze-etching replicas at intermediate magnifications.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 1","pages":"177-86"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20724288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Volume determination of human metaphase chromosomes by scanning force microscopy. 扫描力显微镜法测定人中期染色体体积。

Scanning microscopy Pub Date : 1996-01-01

W Fritzsche, E Henderson

引用次数: 0

Role of calcium oxalate monohydrate crystal interactions with renal epithelial cells in the pathogenesis of nephrolithiasis: a review. 草酸钙一水晶体与肾上皮细胞相互作用在肾结石发病机制中的作用综述。

Scanning microscopy Pub Date : 1996-01-01

J C Lieske, M S Hammes, F G Toback

{"title":"Role of calcium oxalate monohydrate crystal interactions with renal epithelial cells in the pathogenesis of nephrolithiasis: a review.","authors":"J C Lieske, M S Hammes, F G Toback","doi":"","DOIUrl":"","url":null,"abstract":"Renal tubular fluid in the distal nephron is supersaturated with calcium and oxalate ions that nucleate to form crystals of calcium oxalate monohydrate (COM), the most common crystal in renal stones. How these nascent crystals are retained in the nephron to form calculi in certain individuals is not known. Recent studies from this laboratory have demonstrated that COM crystals can bind within seconds to the apical surface of renal epithelial cells, suggesting one mechanism whereby crystals could be retained in the tubule. Adherence of crystals to cells along the nephron may be opposed by specific urinary anions such as glycosaminoglycans, uropontin, nephrocalcin, and citrate. In culture, adherent crystals are quickly internalized by renal cells, and reorganization of the cytoskeleton, alterations in gene expression, and initiation of proliferation can ensue. Each of these cellular events appears to be regulated by extracellular factors. Identification of molecules in tubular fluid and on the cell surface that determine whether a crystal-cell interaction results in retention of the crystal or its passage out of the nephron appears critical for understanding the pathogenesis of nephrolithiasis.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 2","pages":"519-33; discussion 533-4"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20724659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Studies on the role of urinary macromolecules in urolithiasis: review of methodologies and a proposal for a standard reference crystallization system. 尿大分子在尿石症中的作用研究:方法综述和标准参考结晶系统的建议。

Scanning microscopy Pub Date : 1996-01-01

A L Rodgers, D Jappie

{"title":"Studies on the role of urinary macromolecules in urolithiasis: review of methodologies and a proposal for a standard reference crystallization system.","authors":"A L Rodgers, D Jappie","doi":"","DOIUrl":"","url":null,"abstract":"In this study, urine from a calcium oxalate kidney stone former was ultrafiltered (10 kD cut-off). Crystallization was induced in the ultrafiltrate and retentate fractions as well as in a sample of the whole urine. The progress of crystallization was monitored by Coulter Counter and flow cytometry techniques. (The latter has not been used in studies of the role of urinary macromolecules in urolithiasis). Deposited crystals were examined by scanning electron microscopy. Results indicated that urinary macromolecules in this subject are inhibitors of nucleation and aggregation. These results agree with the findings of some workers but disagree with those of others. Indeed, studies on the role played by urinary macromolecules in promoting or inhibiting urolithiasis have failed to produce consistent findings. Examination of the literature reveals that a wide variety of experimental techniques and crystallization systems have been used in these studies and that this might be the cause of the inconsistencies. Based on reported experiences and those of the present study, a standard reference crystallization system is proposed. The key elements of this system involve the use of real urine, ultrafiltration, continuous crystallizer equipment, Coulter Counter procedures and scanning electron microscopy.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 2","pages":"535-45; discussion 545-6"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20724660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The role of calcium in the regulation of apoptosis. 钙在细胞凋亡调控中的作用。

Scanning microscopy Pub Date : 1996-01-01

D J McConkey

{"title":"The role of calcium in the regulation of apoptosis.","authors":"D J McConkey","doi":"","DOIUrl":"","url":null,"abstract":"The recognition that apoptosis is regulated by an evolutionarily conserved set of polypeptides from the nematode Caenorhabditis elegans to humans suggests that a conserved set of biochemical mechanism(s) may also be involved in the response. Early evidence suggested that the endogenous endonuclease implicated in apoptosis in most model systems is Ca(2+)-dependent, and subsequent work from a number of independent laboratories suggests that alterations in cytosolic Ca2+ homeostasis are one of the conserved biochemical pathways regulating the response. Molecular targets for Ca2+ are now being identified and include signal transduction intermediates, endonuclease(s) and proteases, and the enzymes involved in the maintenance of phospholipid asymmetry in the plasma membrane. Furthermore, interesting preliminary work suggests that BCL-2 suppresses apoptosis via a mechanism that is linked to intracellular Ca2+ compartmentalization, and it appears that Ca2+ alterations in some examples of apoptosis occur as the result of changes within the mitochondria. This review will summarize what is known about the role of Ca2+ in the regulation of apoptosis and discuss how Ca2+ might interact with some of the other biochemical signals implicated in cell death.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 3","pages":"777-93; discussion 793-4"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20725186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effect of ionizing irradiation on type I collagen of the tail in growing mice: a histology and electron microscopy study. 电离照射对生长小鼠尾型胶原蛋白的影响:组织学和电镜研究。

Scanning microscopy Pub Date : 1996-01-01

M Q Yang, E Kjellén, C H Håkansson, M Palmegren

{"title":"The effect of ionizing irradiation on type I collagen of the tail in growing mice: a histology and electron microscopy study.","authors":"M Q Yang, E Kjellén, C H Håkansson, M Palmegren","doi":"","DOIUrl":"","url":null,"abstract":"In order to examine the effect of radiation on growing tissue, especially the fibroblasts and their end-product, the collagen fibres, tails from 24 mice were irradiated at an age of 8 days with 20 Gy and 30 Gy (60Co). Tails from 18 animals served as controls. Six mice from each group were sacrificed on day 8, 20 and 30. Transmission electron microscopy was used to examine the fibroblasts and the collagen fibrils. Non-irradiated fibroblasts had a nucleus rich in chromatin and an abundant endoplasmic reticulum with cisternae and condensing vacuoles. On day 20, approximately 50%, and on day 30, 25% of the fibroblasts irradiated with 30 Gy had a sparse endoplasmic reticulum pointing to a reduction of protein synthesis. While, on day 20, the fibrils irradiated with 20 Gy and with 30 Gy had significantly larger diameters compared to the controls, on day 30, the irradiated fibrils had a notably smaller diameter compared to the controls; 30 Gy-fibrils were larger than the 20 Gy-fibrils on both days. On day 20, the binding mean value of the 30 Gy-fibrils exceeded that of the controls and was significantly higher than that of the 20 Gy-fibrils, which was lower, though not significantly, than the controls. On day 30, the banding mean value of the 30 Gy-fibrils was notably lower than the control; and the value of the 20 Gy-fibrils was significantly lower than that of the 30 Gy-fibrils. The results are explained as an edema together with an inhibitory effect on the protein synthesis of the fibroblasts caused by the irradiation. This deduction is further supported by light microscopy of the tails.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 3","pages":"821-31; discussion 831-2"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20725189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The neonatal chinchilla cochlea: morphological and functional study. 新生鼠耳蜗形态与功能研究。

Scanning microscopy Pub Date : 1996-01-01

R V Harrison, J R Cullen, S Takeno, R J Mount

引用次数: 0

Preparation of cultured smooth muscle cells from human myometrium for X-ray microanalysis. 人肌层培养平滑肌细胞的制备及x射线微量分析。

Scanning microscopy Pub Date : 1996-01-01

J Hongpaisan, G M Roomans

{"title":"Preparation of cultured smooth muscle cells from human myometrium for X-ray microanalysis.","authors":"J Hongpaisan, G M Roomans","doi":"","DOIUrl":"","url":null,"abstract":"Methodological aspects of the use of X-ray microanalysis in physiological and pharmacological experiments on cultured myometrial cells were investigated. Cultured human myometrial cells were grown from biopsies after detaching the fibroblasts. Of the cultured cells, 95-98% showed desmin-like immunoreactivity. Transmission electron microscopy showed that subcultured cells were different from myometrial cells in situ. The effects of washing the cells to remove external salt-rich medium were investigated. All solutions removed the external medium, resulting in lower concentrations of Na and Cl. In the cells washed with 0.3 M mannitol, most of the elemental concentrations were significantly lower than in their unwashed counterparts and those washed in the other solutions. In cells washed in either 0.15 M ammonium acetate or distilled water, no significant differences in P and K compared with their unwashed counterparts were found. There were also no significant differences between cells washed in ammonium acetate and in distilled water. In subsequent experiments ammonium acetate was used. Incubation of cells in standard Ringer's solution resulted in an increase in Na and Cl, and a decrease in K, concomitantly with an increase in Ca. Although Ringer's solution per se can elicit changes in diffusible elements in the cells, physiological and pharmacological effects of oxytocin could still be detected in Ringer's solution. However, effects of oxytocin were different when the experiment was done in culture medium, instead of in Ringer's solution.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"10 4","pages":"1181-90"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20764315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative analysis of patch lesions in the chick inner ear following acoustic trauma: optical versus scanning electron microscopy. 鸡内耳损伤斑块的比较分析:光学与扫描电镜。

Scanning microscopy Pub Date : 1995-09-01

H J Adler, J Mantooth, Y Raphael

{"title":"Comparative analysis of patch lesions in the chick inner ear following acoustic trauma: optical versus scanning electron microscopy.","authors":"H J Adler, J Mantooth, Y Raphael","doi":"","DOIUrl":"","url":null,"abstract":"Neonatal chicks were exposed to an octave band noise with a center frequency of 1.5 kHz at 116 dB SPL for 4 hours. Seven days following overstimulation, the birds were sacrificed. Their basilar papillae were removed, fixed in 4% paraformaldehyde, and processed in two steps. First, the ears were immunostained with a supernatant of mouse anti-tectorial membrane antibodies, followed by a diaminobenzidine process. Examinations of the papillae under an optical stereo microscope revealed a patch site with a partially regenerated tectorial membrane (referred to as the honeycomb). After the optical studies, the same ears were post-fixed in 1% osmium tetroxide, dehydrated in ethanol, and processed for scanning electron microscopy (SEM). SEM examinations demonstrated a honeycomb-covered patch lesion in the papilla. Patch lesion perimeters were traced from both the optical and SEM images, and patch areas were calculated. Also, papilla height was measured at the midpoint of the inner ear in both groups. These calculations showed that the patch area and papilla height had shrunk by approximately 37% and 33%, respectively, following the SEM methodology. The decrease in these dimensions may be attributed to several steps required for the SEM specimen preparation, such as critical point drying.","PeriodicalId":21502,"journal":{"name":"Scanning microscopy","volume":"9 3","pages":"825-30; discussion 830-1"},"PeriodicalIF":0.0,"publicationDate":"1995-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18510013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0