Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microscopy, Electron”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMed1989

[Observation of the processes of low-temperature crystallization in an aqueous cell suspension by electron microscopy].

The possibility of using electron microscopy for the study of the processes of the low-temperature crystallization of water in cell suspension is discussed with E. coli M-17 culture used as an example. The replacement of water in the frozen state permits the observation of processes occurring in the sample at low temperature. The advantages of the method are demonstrated in the study of objects previously frozen at different rates.

Bacteriological Techniques↗
PubMed1989

Localization of antiglomerular basement membrane-binding polyclonal antibodies in rat lung and kidney using post-embedding immunogold electron microscopy.

Post-embedding immunogold electron microscopy (IAuEM) techniques utilizing low-temperature embedding in Lowicryl K4m and LR White resin were used to localize the binding sites of two sheep anti-rat glomerular basement membrane polyclonal antibodies (P1 and P2) and a sheep anti-rat lung antigen antibody. P1 localization was bilaminar in a linear pattern along the subepithelial and particularly the subendothelial aspect of the glomerular basement membrane. P2 was bound diffusely throughout the lamina densa, even at supramaximal doses. The anti-lung antibody bound in an interrupted linear pattern throughout the lung basement membrane (alveolar and capillary), and showed an intense, diffuse binding to the glomerular basement membrane. IAuEM allowed definition of the precise basement membrane binding sites of these polyclonal reagents.

Animals↗
PubMedDate not supplied

[Stereomorphological relationship between colonic adenomas and peri-adenomatous mucosa in scanning electron microscopy. Histogenetic correlations].

Using scanning electron microscopy (SEM), then light microscopy, the authors have studied 25 colonic adenomas, 5 specimens of peri-adenomatous mucosa and 9 specimens of normal colonic mucosa. Comparison between SEM features and histological characteristics has shown that each of the three histological entities had an specific surface architecture. Comparative analysis of the different aspects observed at SEM has shown a close architectural relationship between the adenomas and the adjacent mucosa, and suggests the hypothesis that adenomatous polyps are formed by invagination of the surface epithelium which has a well-known capacity of proliferation.

Adenoma↗
PubMed1979

Scanning electron microscopy of blood cells.

Scanning electron microscopy (SEM) is an invaluable tool for studying the surface morphology of isolated blood cells. We have used a simple preparative technique for SEM to study the erythrocytes from a case of Congenital Dyserythropoietic Anaemia type II and the leucocytes from healthy individuals or patients with leukaemia or lymphoma. This rapid and inexpensive technique for fixation and dehydration of blood cells was found to be equally reliable for obtaining micrographs of healthy or diseased leucocytes or erythrocytes.

Anemia, Hemolytic, Congenital↗
PubMed1988

[Muscular tunic of the dog ureter in the normal state and in ureterohydronephrosis (data of scanning electron microscopy)].

By means of scanning electron microscopy and macro- microscopical methods in 16 mongrel dogs the ureters have been studied, normal and at ureterohydronephrosis. The ureteral muscles are spirally shaped. The external muscular layer is oriented along the spiral, its step approximately corresponds to the length of the peristaltic wave. The spiral-shaped course of the muscular fasciculi in the middle layer is of opposite direction, the spiral step corresponds to the ureter diameter. The internal muscular layer is formed as a result of changes in the spiralization angle of the middle muscular layer from outside into inside. Fibrills of the connective tissue framework possess predominantly longitudinal orientation. At ureterohydronephrosis, together with increasing diameter of the ureter, the step of the muscular spiral decreases, the connective tissue fibrillar framework acquires a net-like structure.

Animals↗
PubMed1986

The three-dimensional microstructure of the liver. A review by scanning electron microscopy.

The improvement in scanning electron microscopy (SEM) techniques has permitted us to describe the microstructure of the liver. By SEM, the liver peritoneal surface is composed of flat mesothelial cells possessing microvilli and cilia. Hepatic sinusoids connect the portal vessels with the terminal branches of the hepatic vein (central veins). Endothelial cells of the portal space arteries are elongated and arranged longitudinally, while those of the central and portal veins are polygonal and flattened, possessing microvilli. The sinusoidal endothelial cells show both small fenestrations (sieve plates), up to 200 nm in diameter, and large ones, up to 1 micron. Within the sinusoids are seen bridging structures, covered by fenestrated endothelium, seeming to have a fibrillar core. Kupffer cells resemble macrophages, showing microvilli, blebs, lamellipodia and filopodia. Within the Space of Disse are seen the fat-storing cells, having laminar dendritic projections. The polyhedral liver cell faces the Space of Disse (vascular pole) or faces an adjacent hepatocyte (biliary pole). Vascular facets are evenly covered by microvilli. Biliary facets show a central longitudinal depression, bordered by microvilli (bile hemicanaliculi). Canaliculoductular junction and bile duct epithelia show blebs, microvilli and cilia. Up to now, fetal liver and liver pathology have been scarcely investigated by SEM: in the future, they can be successfully approached by three-dimensional studies.

Animals↗
PubMed1987

[Anatomical variations and anomalies of the musculus stapedius tendon. Study by scanning electron microscopy].

The authors used scanning electronic microscopy to investigate and define morphological characteristics of the musculus stapedius tendon: the opening through which the tendon protrudes at the eminentia pyramidalis and it can be found at its base. Fibers of the tendon may directly be attached to the bony surface of the stages or its prolongation of various forms and dimensions. In some cases the tendon fibrous bundles are more or less ossified. In one patient who was operate we found a congenital malformation manifested as absence of the tendon and deformation of the stapes. The tendon absence is found in 0.5% of cases.

Humans↗
PubMed1985

A study of endometrial adenocarcinoma treated with tamoxifen by scanning and transmission electron microscopy.

By scanning and transmission electron microscopy the Authors studied four cases of endometrial adenocarcinoma (stage I, G1) after 15-days treatment with Tamoxifen (20 mg X 2) before surgery. The ultrastructural findings, similar to those observed in untreated adenocarcinomas but quite different from those obtained in MAP-responsive cases - as other Authors reported too - seem to indicate an almost complete absence of secretory or cytotoxic induction at least as far as 15-days treatment is concerned. According to the Authors this study raises many doubts about the usefulness of a first-instance therapeutical protocol based on Tamoxifen alone. However they believe that Tamoxifen can be utilized combined with a progestational agent in a simultaneous or sequence treatment.

Adenocarcinoma↗
PubMed1985

Electron microscopy in rhinology.

In rhinology, electron microscopy has been a useful research tool for the past 15 years, but provided only a few direct clinical applications. In this review, the author's work on the human nasal mucosa and the studies of other investigators are discussed, with the emphasis on allergic reactions and disturbances of the autonomous nervous system as well as the immotile cilia syndrome.

Autonomic Nervous System↗
PubMed1979

[2 cases of alveolar sarcoma. Study by electron microscopy and cytoenzymology].

Study by electron microscopy and light cytoenzymology of two cases of alveolar sarcoma of the thigh occurring in young men indicated it to be an active tumour with an apparently functional organoid arrangement, characterised by an abundance of capillary vessels. The secretory nature of the cell elements was suggested by the marked development of smooth and granular reticular systems. The morphological result of this secretory activity was constituted by vesicular bodies with dense contents, surrounded by a membrane and sometimes containing periodic paracrystalline structures. This intravacuolar crystalline organisation goes hand in hand with an increase in acid phosphatase activity suggesting possible crinophagia. Amongst the different hypotheses advanced in the past, the morphological appearances seen here would most likely correspond with the endocrine nature of this tumour.

Adult↗
PubMed1981

Scanning electron microscopy of intracardiac myxoma.

Scanning electron microscopy was utilized to study the surface morphology of intracardiac myxomas and to compare it with that of an atrial thrombus. The thrombus was only partially endothelialized, whereas myxomas were almost always completely covered by endothelial cells. Endothelium-lined crevices and clefts were a striking feature of the myxoma, and they were not seen in the atrial thrombus. In areas where the surface endothelium was denuded, fibrin and platelet aggregates were noted in both the myxoma and the thrombus.

Heart Atria↗
PubMed1994

Analysis of dental adhesive systems using scanning electron microscopy.

This study used scanning electron microscopy (SEM) to evaluate the effects of various acid conditioners (etchants) on dentine surfaces. The conditioners completely removed the smear layer from dentine and opened the dentinal tubules, but some also left debris or a reaction product on the surface. The study also evaluated the resin-dentine interfaces produced by five new-generation dentine bonding systems: All-Bond 2, Amalgambond, Gluma 2000, OptiBond, and Scotchbond Multi-Purpose. All-Bond 2, Amalgambond, OptiBond, and Scotchbond Multi-Purpose formed acid-resistant hybrid layers and intra-tubular resin tags when they were applied to visibly moist dentine.

Acid Etching, Dental↗
PubMed1993

Cell surface patterns in normal human oral gingival epithelium. A quantitative scanning electron microscopy approach.

We used scanning electron microscopy to study the morphological surface patterns of cells that cover the attached gingiva and intervestibular papilla of the human oral gingival epithelium. Five patterns are described on the basis of the overall appearance of morphological surface markers: microvilli, parallel, fingerprint, reticular and pitted. Statistical analyses detected significant differences in the frequency of each pattern in both regions of the oral gingival epithelium, and showed the reticular and fingerprint types to predominate. We propose that our description of the different morphological surface types may be of use as a standard for subsequent cytological studies and characterizations of morphological alterations in diseased gingiva.

Dental Papilla↗
PubMed1976

[Wall structure of cisterna chyli in humans studied by light and scanning electron microscopy].

Comparing light and scanning electron microscopy of a chronically lymphostatic and two normal cisternae chyli made visible a normally folded and smoothened (under load) cisternal wall. Different orifices of the supplying lymph-collecting vessels with varying valve structures were seen. The functional meaning of the orifice types and of the valves for the uptake of lymph and chylus into the cisterna as well as for the blockage of lymphatic reflux out of the filled cisterna were discussed.

Adult↗
PubMedDate not supplied

Application of electron microscopy in the definitive diagnosis of effusions.

Electron microscopy was performed on a series of body cavity fluid specimens to evaluate the usefulness of this technique in the diagnosis of effusions. During a six-month period, 42 specimens were examined, 19 benign and 23 malignant. In two cases, the electron microscopic findings were crucial to the diagnosis. In a third case, electron microscopy helped to confirm the diagnosis and avoid unnecessary surgery. In a number of other cases, ultrastructural evaluation demonstrated special cell characteristics not evident in routine light microscopic studies. Based on these findings, we conclude that electron microscopy has a definite place in the diagnosis of effusions and should be increasingly utilized on a selective basis in the evaluation of body cavity fluid specimens. In addition, electron microscopic studies on cells in effusions provide an excellent source of material for educational and research purposes.

Adenocarcinoma↗
PubMed2002

Electron and immuno-electron microscopy of abdominal fat identifies and characterizes amyloid fibrils in suspected cardiac amyloidosis.

We evaluated the role of electron microscopy and immuno-electron microscopy studies on abdominal fat fine-needle biopsy samples in diagnosis and characterization of cardiac amyloidosis. The series consists of 15 patients with echocardiographic evidence of "restrictive cardiomyopathy" suspected to be due to amyloidosis. Patients underwent: clinical examination, electrocardiography, 2-D and Doppler echocardiography, immunofixation of serum and urine for detection of monoclonal immunoglobulins, and abdominalfat biopsies that were investigated with polarized light (Congo red), electron and immuno-electron microscopy using specific antibodies to kappa and lambda light chains, apolipoprotein A1, serum amyloid A (SAA), and transthyretin (TTR). Ultrastructural study of abdominal fat samples identified amyloid deposits in 15/15 cases. Immuno-electron microscopy specifically stained amyloid fibrils with antibodies anti-lambda (n = 8), -kappa (n = 2), -apolipoprotein A1 (n = 2) and -TTR (n = 3). Immuno-electron microscopy revealed TTR immuno-labelling in 2 patients with accidental monoclonal components, and a A reaction in I patient without monoclonal components. TTR and apolipoprotein A1 positive cases carried missense mutations in the corresponding genes. Our results demonstrate that amyloid deposits are present in the abdominalfat of patients suspected to have cardiac amyloidosis and that immuno-electron microscopy was able to characterize the amyloid protein in all cases.

Abdomen↗
PubMed2004

Three-dimensional electron microscopy at molecular resolution.

Emerging methods in cryo-electron microscopy allow determination of the three-dimensional architectures of objects ranging in size from small proteins to large eukaryotic cells, spanning a size range of more than 12 orders of magnitude. Advances in determining structures by "single particle" microscopy and by "electron tomography" provide exciting opportunities to describe the structures of subcellular assemblies that are either too large or too heterogeneous to be investigated by conventional crystallographic methods. Here, we review selected aspects of progress in structure determination by cryo-electron microscopy at molecular resolution, with a particular emphasis on topics at the interface of single particle and tomographic approaches. The rapid pace of development in this field suggests that comprehensive descriptions of the structures of whole cells and organelles in terms of the spatial arrangements of their molecular components may soon become routine.

Cryoelectron Microscopy↗
PubMed1999

A rationalised virological electron microscope specimen testing policy. PHLS North West Viral Gastroenteritis and Electron Microscopy Subcommittee.

The aim of this project was to produce guidance for a rationalised virological electron microscopy specimen testing policy for PHLS North West, to facilitate centralisation of a groupwide diagnostic electron microscopy service on a single site. Careful specimen selection to limit numbers and the groupwide use of commercially available enzyme immunoassays has allowed PHLS North West to reduce the number of specimens prepared for electron microscopy. The rationalised virological electron microscopy specimen testing policy has enabled a diagnostic electron microscopy service to be provided from a single site with a manageable workload. Implementation of this specimen testing policy by PHLS North West has been successful and may be applicable to other laboratories (or groups of laboratories) to maximise the use of expensive electron microscopy facilities.

Aged↗