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PubMed1981

Evaluation of vasogenic edema in experimental brain tumors by cathodoluminescence and fluorescence microscopy.

Cathodoluminescence and fluorescence microscopy have been used to study vasogenic edema in experimentally induced brain tumors in rats. Both methods are suited for the demonstration of FITC- or TRITC-coupled antiserum, and thus allow the evaluation of serum protein extravasation. Cathodoluminescence is more time consuming and laborious than fluorescence microscopy, but it has distinct advantages: Contrast enhancement improves the differentiation between certain cell types, and the higher resolution of the scanning electron microscope allows the identification of subcellular regions which cannot be recognized by conventional fluorescence microscopy.

Animals↗
PubMed1975

Human nervous system tumors. Observations by high voltages electron microscopy.

Thick sections (0.5--2 mu) of biopsies from human nervous system tumors (Schwannoma, ependymoma, medulloblastoma), fixed in aldehydes followed by osmium, and stained with uranyl acetate and lead, have been studied at 2.5 MV, and compared to thin sections of the same material observed by ordinary low voltage electron microscopy. High voltage electron microscopy permits direct observation of cell fine structure in three dimensions, including the spatial relations of organelles. Details of contours of nuclear envelopes, shapes of mitochondria, fine aspects of the structure of cell surfaces and processes, such as the flat sheet-like and irregular cylindrical processes of Schwannoma cells, the small projections and ridges on their surfaces, and microvilli and cilia of ependymoma cells, and other features have been observed. These initial observations demonstrate the applicability of high voltage electron microscopy to further study of neural neoplasms.

Adolescent↗
PubMed1979

Chronic myelomonocytic leukemia: light and electron microscopy of the bone marrow.

Clinical data and light and electron microscopic findings are presented in a patient with chromic myelomonocytic leukemia of about 5 years' duration and no need for specific therapy. Cytogenetic studies failed to demonstrate a Philadelphia-chromosome. The leading clinical symptoms were anemia, moderate hepatomegaly, and leukocytosis with monocytes in the peripheral blood count. Light microscopy of bone marrow cores showed hypercellularity of neutrophil granulocytic and monocytic cell lines including some precursor forms. Electron microscopy confirmed the existence of a biphasic myelomonocytic cell proliferation with predominance of mature forms in both lineages; there were no gross cellular abnormalities and no "hiatus leukaemicus". Consupicuous were cells of an undeterminated origin apparently neither belonging to the neutrophil granulocytic nor monocytic series and large histiocytic cells, possibly corresponding to the so-called sea-blue histiocytes of light microscopy. The high degree of maturation of both cell lines in the bone marrow is in accordance with the relatively benign and prolongated course of this rare type of leukemia.

Aged↗
PubMed1991

Effect of dopamine agonist medication on prolactin producing pituitary adenomas. A morphological study including immunocytochemistry, electron microscopy and in situ hybridization.

Conventional light microscopy, immunocytochemistry, electron microscopy and in situ hybridization were used to evaluate the effect of dopamine agonists (bromocriptine-LAR and bromocriptine) on the morphology of surgically removed prolactin (PRL)-producing pituitary adenomas. Dopamine agonist therapy resulted in decrease of serum PRL, clinical improvement and tumour shrinkage. Using light and electron microscopy cellular atrophy, interstitial and perivascular fibrosis were noted; in several tumours connective tissue accumulation was pronounced. The cellular response was not uniform. In some adenomas populations of large cells and small cells were distinguished. The large cells contained immunoreactive PRL and expressed the PRL gene indicating resistance to dopamine agonists. It appears that these cells retained the potential to secrete PRL and proliferate despite exposure to dopamine agonists. In the small cells, PRL immunoreactivity and PRL gene expression decreased providing evidence that both PRL release and synthesis were blocked. Small cells can persist in tumours after discontinuation of dopamine agonist medication suggesting these small cells are irreversibly suppressed and are not capable of regaining their endocrine function and proliferative capability. The formation of irreversibly suppressed PRL cells may explain why some PRL-producing adenomas do not recur after withdrawal of dopamine agonists.

Adenoma↗
PubMed1990

Electron microscopy: a contribution to further classification of acute unclassifiable childhood leukemia.

The ultrastructural, light microscopical and immunological features of twelve cases of acute childhood leukemia are described. Nine cases were unclassifiable by light microscopy, morphology and cytochemistry, and three were difficult to classify because of a low percentage of Sudan-Black B positive blasts. By means of electron microscopy (including peroxidase cytochemistry), two main groups were seen: 1. Acute myeloid leukemia, in which could be distinguished a) a more differentiated myeloid leukemia, b) a leukemia with megakaryoblastic involvement and c) a minimally differentiated acute myeloid leukemia with granules present and 2. lymphoblastic leukemia. One case could not be classified. The first group included two possible cases of a hybrid leukemia with CD19 or CD10 positivity as well as ultrastructural peroxidase activity. We conclude that electron microscopy aids to further classification of minimally differentiated and hybrid acute leukemias.

Adolescent↗
PubMed1985

Detection of human rotavirus by nucleic acid analysis in comparison to enzyme-linked immunoassay and electron microscopy.

The results of RNA analysis for the detection of rotavirus were compared with those of a standard enzyme-linked immunosorbent assay (ELISA) and electron microscopy using 212 faecal specimens obtained from 200 children with gastroenteritis. Rotavirus was extracted directly from faecal specimens and RNA segments were made visible by polyacrylamide gel electrophoresis using a silver staining technique. Of the 212 faecal specimens 137 were found to be positive in ELISA, 125 in RNA analysis and 121 in both methods. Forty-nine of the 212 specimens were also investigated by electron microscopy. Thirty-five were positive when examined by electron microscopy, 37 were positive in ELISA and 33 in RNA analysis. RNA analysis of 119 faecal samples in outbreaks and sporadic cases of rotavirus infection yielded 42 different rotavirus electrophoretypes. The results indicated that no one method was sufficient to detect all positive specimens and that RNA analysis is useful in epidemiological studies.

Electrophoresis, Polyacrylamide Gel↗
PubMed1989

Specular and scanning electron microscopy in diffuse silicone keratopathy.

In a 50-year-old man, penetrating keratoplasty was carried out to treat a diffuse silicone keratopathy that developed 2 years after a pars plana vitrectomy combined with an intravitreal silicone injection for a complicated retinal detachment in the only aphakic eye. At 2 weeks after the intravitreal silicone injection, specular microscopy revealed a mild pleomorphism in the corneal endothelium and an endothelial cell loss of 26%. After 5 months, a small silicone drop floated in the anterior chamber and the first signs of diffuse keratopathy were observed. At the same time, specular microscopy revealed severe damage to the endothelial cells and a cell loss of 69%. After the keratoplasty, scanning electron microscopy of the corneal button showed a filamentous structure of the posterior surface of the cornea, with fibroblast-like cells; the endothelial cells were absent.

Anterior Chamber↗
PubMed1996

Monoclonal antibodies to proteins of the myelin-like sheath of earthworm giant axons show cross-reactivity to crayfish CNS glia: an immunogold electron microscopy study.

Monoclonal antibodies were generated to the proteins in myelin-like membranes isolated from the nerve cords of the earthworm, Lumbricus terrestris. One of these showing cross-reactivity to 30-32 and 40 kDa proteins was shown by immunofluorescence microscopy and immunogold electron microscopy to be bound primarily to glial cell process and their membranes and the myelin-like layers. This antibody cross-reacted with proteins of 60-65, 42, and 40 kDa in crayfish (Procambarus clarki) nerve cord homogenates. Localization by immunoelectron microscopy showed the antibody to be bound exclusively to the membranes of the glial processes ensheathing the axons in the crayfish nerve cord. Thus, the proteins in earthworm and crayfish glial cell membranes have some epitopes in common. We suggest that this may represent an evolutionary conservation of these proteins.

Animals↗
PubMed1976

The effect of grinding of human dentine examined by X-ray diffraction, infrared spectroscopy, and electron microscopy.

Analysis of human dentine by infrared spectrophotometry suggests that ball-grinding may result in damage of the apatite crystallites. The present study includes further assessments of this effect by X-ray diffraction, infrared spectroscopy, and electron microscopy. Each of three coarse-ground dentine samples (Group I) was divided into three portions of 30 mg. One of these portions was ball-ground for approximately 1 min (Group II), the second portion for 6 min (Group III), and the third portion for 23 min (Group IV). The 002 reflection showed line broadening, most marked from Group II to III. Electron microscopy showed a gradual change in crystallite appearance with increased grinding, most pronounced from Group II to III. These observations indicate that by prolonged grinding a limit is approached where no further changes in the crystallites occur. Electron microscopy also indicated that fracture of the crystallites might have occurred. This was probably accompanied by strains in the lattice. The infrared spectra indicated that no breakdown of the apatite structure had occurred during the entire grinding.

Apatites↗
PubMed1989

Rapid changes of light microscopic indices of osteoclast-bone relationships correlated with electron microscopy.

The relationships of tibial endosteal osteoclasts to bone surfaces were quantitatively evaluated during initiation of calcium repletion in calcium-deficient rats. To do this, indices of osteoclast-bone relationships obtained by light microscopy were devised and evaluated by comparing with those obtained by electron microscopy (EM). These indices are the percent of the osteoclast width that (1) exhibits markers indicative of a ruffled border, (2) is in close contact with bone, (3) is isolated from bone by other cell types, and (4) is separated from bone by intercellular material. The indices obtained by light microscopy were strongly correlated with similar indices obtained by EM and were equally sensitive but considerably easier to obtain. The ruffled border and contact index were significantly decreased by 3 hours after beginning the meal whereas cells of other types became interposed between the osteoclasts and the bone.

Animals↗
PubMed2000

Chondrotoxicity of ciprofloxacin in immature beagle dogs: immunohistochemistry, electron microscopy and drug plasma concentrations.

The systemic effects of ciprofloxacin in immature Beagles were studied. Dogs of 10-11 weeks were dosed orally for 5 days with 0 (n=3), 30 (n=5) and 200 (n=5) mg ciprofloxacin/kg body wt. Plasma concentrations were measured by high-performance liquid chromatography (HPLC) 1 h after dosing (assuming to be peak concentrations). In view of the high doses used, the plasma concentrations were rather low and declined during the study period. For example, plasma concentrations in the high dose group were 6.6 +/- 0.9 mg/l (day 1), 3.9 +/- 1.4 mg/l (day 3), and 2.6 +/- 1.6 mg/l (day 5). In control dogs and in dogs treated with the low dose of ciprofloxacin no pathological changes were seen by light microscopy. However, cleft formation and erosions were observed in joint cartilage from two of five dogs treated with 200 mg/kg. It is noteworthy that despite the high dose used cartilage lesions were not detectable in all five dogs of this group by light microscopy. Using antibodies against cell membrane receptors (e.g. the alpha(5)beta(1)-integrin) or matrix components (fibronectin, collagen II) the articular cartilage effects were studied in detail by immunohistochemistry. The most sensitive alteration was an increase in fibronectin which was detectable in the vicinity of the lesions in cartilage samples from the group of dogs administered the high dose. No clear-cut changes were seen with the use of antibodies against other matrix components. Electron microscopy revealed typical alterations in chondrocytes from dogs treated with ciprofloxacin: e.g., swollen mitochondria and enlarged rough endoplasmic reticulum. These changes were much more pronounced in dogs from the high dose group than in dogs from the low dose group. Our main conclusion is that after oral administration ciprofloxacin exhibits rather low chondrotoxicity, even in the most sensitive species known to date. This correlates with the findings in humans that ciprofloxacin seems to be less chondrotoxic than pefloxacin or other quinolones.

Animals↗
PubMed2004

New dimension in nano-imaging: breaking through the diffraction limit with scanning near-field optical microscopy.

In recent years scanning near-field optical microscopy (SNOM) has developed into a powerful surface analytical technique for observing specimens with lateral resolution equal to or even better than 100 nm. A large number of applications, from material science to biology, have been reported. In this paper, two different kinds of near-field optical microscopy, aperture and scattering-type SNOM, are reviewed together with recent studies in surface analysis and biology. Here, near-field optical techniques are discussed in comparison with related methods, such as scanning probe and standard optical microscopy, with respect to their specific advantages and fields of application.

Microscopy↗
PubMed2000

Formation of unilamellar vesicles by repetitive freeze-thaw cycles: characterization by electron microscopy and 31P-nuclear magnetic resonance.

It has been reported that repetitive freeze-thaw cycles of aqueous suspensions of dioleoylphosphatidylcholine form vesicles with a diameter smaller than 200 nm. We have applied the same treatment to a series of phospholipid suspensions with particular emphasis on dioleoylphosphatidylcholine/dioleoylphosphatidic acid (DOPC/DOPA) mixtures. Freeze-fracture electron microscopy revealed that these unsaturated lipids form unilamellar vesicles after 10 cycles of freeze-thawing. Both electron microscopy and broad-band 31P NMR spectra indicated a disparity of the vesicle sizes with a highest frequency for small unilamellar vesicles (diameters < or =30 nm) and a population of larger vesicles with a frequency decreasing exponentially as the diameter increases. From 31P NMR investigations we inferred that the average diameter of DOPC/DOPA vesicles calculated on the basis of an exponential size distribution was of the order of 100 nm after 10 freeze-thaw cycles and only 60 nm after 50 cycles. Fragmentation by repeated freeze-thawing does not have the same efficiency for all lipid mixtures. As found already by others, fragmentation into small vesicles requires the presence of salt and does not take place in pure water. Repetitive freeze-thawing is also efficient to fragment large unilamellar vesicles obtained by filtration. If applied to sonicated DOPC vesicles, freeze-thawing treatment causes fusion of sonicated unilamellar vesicles into larger vesicles only in pure water. These experiments show the usefulness of NMR as a complementary technique to electron microscopy for size determination of lipid vesicles. The applicability of the freeze-thaw technique to different lipid mixtures confirms that this procedure is a simple way to obtain unilamellar vesicles.

Freeze Fracturing↗
PubMed2000

The need for a shared database infrastructure: combining X-ray crystallography and electron microscopy.

Advances in structural biology are opening greater opportunities for understanding biological structures from the cellular to the atomic level. Particularly promising are the links that can be established between the information provided by electron microscopy and the atomic structures derived from X-ray crystallography and nuclear magnetic resonance spectroscopy. Combining such different kinds of structural data can result in novel biological information on the interaction of biomolecules in large supramolecular assemblies. As a consequence, the need to develop new databases in the field of structural biology that allow for an integrated access to data from all the experimental techniques is becoming critical. Pilot studies performed in recent years have already established a solid background as far as the basic information that an integrated macromolecular structure database should contain, as well as the basic principles for integration. These efforts started in the context of the BioImage project, and resulted in a first complete database prototype that provided a versatile platform for the linking of atomic models or X-ray diffraction data with electron microscopy information. Analysis of the requirements needed to combine data at different levels of resolution have resulted in sets of specifications that make possible the integration of all these different types in the context of a web environment. The case of a structural study linking electron microscopy and X-ray data, which is already contained within the BioImage data base and in the Protein Data Bank, is used here to illustrate the current approach, while a general discussion highlights the urgent need for integrated databases.

Crystallography, X-Ray↗
PubMed2006

High-resolution MR imaging of the proximal zone of the lunotriquetral ligament with a microscopy coil.

OBJECTIVE: To evaluate high-resolution MRI of the proximal zone of the lunotriquetral ligament (LTL) using a microscopy surface coil with a 1.5 T scanner. DESIGN AND SUBJECTS: The proximal zone of the LTL was reviewed in 90 subjects (23 asymptomatic normal volunteers and 67 patients with suspicion of triangular fibrocartilage complex injury) with high-resolution MRI using a 47-mm microscopy surface coil. High-resolution MR images were obtained with gradient recalled echo (GRE) T2*-weighted sequence and short tau inversion recovery imaging, with a 1- to 1.5-mm slice thickness, a 50-mm field of view, an imaging matrix of 140-224x512 using zero fill interpolation, and 3-4 excitations. As a qualitative analysis, the LTL was classified in shape and signal intensity. RESULTS: The triangle-shaped low-signal-intensity LTL was identified in 77 of 90 subjects (85.6%) on GRE images. The triangle was classified as regular (41.1%), broad-based (20.0%), narrow-based (6.7%), or asymmetrical (17.8%). The bar-shaped ligament was seen in one patient, and unclassified ligaments were seen in 12 patients. All volunteers showed triangle-shaped LTL. The MR signal intensity of the proximal zone in the LTL was characterized as homogeneously low intensity (type 1; 33.8%), linear intermediate or high signal intensity traversing the distal surface of the LTL (type 2; 45.5%), and linear intermediate or high intensity traversing both distal and proximal surfaces of LTL (type 3; 20.8%). CONCLUSION: The proximal zone of the LTL showed a broad spectrum of normal variations in shape and signal intensity on high-resolution MR images with a microscopy coil.

Adolescent↗
PubMed2005

[In vivo confocal corneal microscopy after keratoplasty].

BACKGROUND: Seven eyes with clear grafts after penetrating keratoplasty were examined with in vivo confocal corneal microscopy in 1999. Our aim was the confocal microscopic investigation of the subclinical changes in clear grafts after long-term follow-up. METHODS: The preoperative diagnoses were keratoconus (two), granular corneal dystrophy (two), pseudophakic bullous keratopathy due to ACL (two), and corneal ulcer (one). The epithelium, corneal nerves, keratocytes of the anterior and posterior stroma, and endothelium were evaluated with confocal microscopy. RESULTS: Mean density of basal epithelial cells was 3928+/-378 cells/mm(2) at 15 months and 3284+/-565 cells/mm(2) at 66 months postoperatively. At 15 months the keratocyte density was 750+/-113 cells/mm(2) in the anterior stroma and 601+/-98 cells/mm(2) in the posterior stroma, at 66 months 383+/-53 cells/mm(2) in the anterior stroma and 411+/-98 cells/mm(2) in the posterior stroma. Endothelial cell density decreased from 1719+/-576 cells/mm(2) (15 months) to 965+/-272 cells/mm(2) (66 months). CONCLUSIONS: In the follow-up period a significant decrease of keratocyte and endothelial cell density was detectable with confocal microscopy. The clinical importance of our findings must be clarified with further examinations on more patients.

Adult↗
PubMed2002

[Diffuse lamellar keratitis after laser in situ keratomileusis. Clinical and confocal microscopy findings].

BACKGROUND: Diffuse lamellar keratitis (DLK) is a sterile inflammation after lamellar corneal surgery. A clinical staging for DLK was recently set up. In this observational case series, the clinical and confocal microscopic findings of stages 1-3 are reported. METHODS: Six eyes of six patients (three eyes with DLK stage 1, two eyes with DLK stage 2, and one eye with DLK stage 3) were examined by slit lamp biomicroscopy and confocal microscopy. RESULTS: In all cases, confocal microscopy showed an infiltration of inflammatory cells into the anterior stroma and the flap interface. The number of cells varied between the eyes with DLK stage 1, and both stage 2 corneas had dense infiltrates. In the eye with stage 3 DLK, an aggregation of decayed cells, most likely granulocytes, was noticed clinically and by confocal microscopy. CONCLUSIONS: The DLK stages represent different clinical intensities of interface inflammation after LASIK. While stages 1 and 2 have a similar confocal microscopic appearance, stage 3 is a result of aggregation of a high amount of inflammatory cells.

Adult↗
PubMed2004

Prenatal diagnosis of Pompe disease by electron microscopy.

INTRODUCTION: Pompe disease is one of the lysosomal storage disorders caused by alpha-glucosidase deficiency. The disease is characterized by accumulation of glycogen in the lysosome. The accumulation has unique ultrastructural features, which enable a prenatal diagnosis possible by electron microscopy. MATERIALS AND METHODS: A prenatal diagnosis of Pompe disease by electron microscopic study of chorionic villus biopsies is described in a fetus of a mother whose previous child had died of the disease. RESULTS: Electron microscopy revealed fibrocytes with typical vacuoles filled with glycogen. A prenatal diagnosis of Pompe disease was made and subsequently confirmed by the autopsy study of the abortus. CONCLUSION: We report the usefulness of electron microscopy for prenatal diagnosis in the first trimester of Pompe disease.

Abortion, Induced↗