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At least 307 records · Page 17Linked to original sources
PubMed1990

Rhodamine 123 phototoxicity in laser-irradiated MGH-U1 human carcinoma cells studied in vitro by electron microscopy and confocal laser scanning microscopy.

Rhodamine 123 (R123) is a permeant, cationic, fluorescent dye that localizes preferentially within mitochondria of living carcinoma cells. MGH-U1 human bladder carcinoma cells incubated in vitro with 10 microM R123 for 30 min and then irradiated at 514.5 nm with an argon ion laser underwent selective, phototoxic injury to mitochondria. Ultrastructurally, treatment with R123 plus irradiation with 10 J/cm2 caused selective, progressive mitochondrial alterations consisting of disruption of cristae, vacuolization, swelling, increasing numbers of ring-shaped and angulated mitochondria at 4 to 8 h after irradiation, and obliteration of many mitochondria at 24 to 48 h. Confocal laser scanning microscopy after treatment with R123 plus irradiation with 10 to 30 J/cm2 demonstrated altered uptake and localization of subsequently administered R123, accompanied by striking mitochondrial fragmentation. Irradiation caused a dose-dependent depletion of extractable R123, due to a photosensitized efflux that began immediately and progressed by 4 h after irradiation with 10 to 30 J/cm2; further uptake after reincubation in the presence of R123 was also quantitatively impaired in cells previously irradiated with 30 J/cm2.

Carcinoma, Transitional Cell↗
PubMed1979

[Comparative endoscopic, light microscopy and scanning electron microscopy studies of the gastric mucosa in patients with chronic uremia].

Ten patients suffering from chronic uremia were selected for comparison studies of gastric mucosa. With endoscopy erosive gastritis was seen in the corpus and antrum of five patients and in the fundus of two patients. Conventional microscopy (nine patients) revealed chronic gastritis I three times in the fundus and five times in the corpus. Gastritis II was localized once in the corpus and twice in the antrum. Gastritis III was present in the antrum of four patients. Under the scanning electron microscope lesions of gastric mucosa were present in all ten cases. Single cell necrosis (A), mucosal defects involving basal membrane (B), destruction of tunica propria (C), and muscularis mucosae with bleeding (D) were seen. Mucosal lesions A and B are early stages of gastric erosions. The most severe lesions were seen in the antrum mucosa with all three methods.

Chronic Disease↗
PubMed1983

[Use of scanning electron microscopy coupled with transmission electron microscopy in comparative studies of the relation between Schistosoma mansoni and Salmonella typhimurium].

Relations between Schistosoma mansoni and Salmonella typhimurium are studied in vivo and in vitro using scanning and transmission electron microscopy as complementary methods. Salmonellae adhesion is a specific process materialized in special places of male and mature schistosome tegumental surface. Interactions are marked by bacterial strong fibres creating a network all around Schistosoma where Salmonellae are dividing. Membrane junction is the last stage leading to symbiotic balance between two biologic systems.

Animals↗
PubMed1981

[Microscopy and electron microscopy of the Hertwig sheath in the mouse].

The structure and ultrastructure of Hertwig's sheath have been studied in the mice on molar tooth germs collected on day 16. On a morphological basis, two parts, a diaphragm portion and a sheath part could be described. The diaphragm portion consisted of two layers, one internal and one external with in between occasionally cells disposed in quincunx. Mitotic activity was noted in the external layer. This fact raised the possibility of the existence of a cellular flow from this layer towards the internal counterpulpal layer. The permanent existence of the sheath during root elaboration could thus be explained. In the internal layer structural modifications and cell axis variations seemed to be related to the odontoblast differentiation. In the "sheath" part electron microscopy revealed the existence of a fine layer of unmineralized collagen fibrils which remained under the internal epithelial layer. The observations related to the structure of the periradicular sheath cells questioned the hypothesis whether these cells assume secretory potentials.

Animals↗
PubMed1995

Scanning electron microscopy and transmission electron microscopy aspects of synergistic antitumor activity of vitamin C - vitamin K3 combinations against human prostatic carcinoma cells.

A MTT/formazan assay was used to evaluate the antitumor activity of vitamin C (Vit C), vitamin K3 (Vit K3), or vitamin C:vitamin K3 combinations against a human prostatic carcinoma cell line (DU145). Both Vit C and Vit K3 alone exhibited antitumor activity, but only at elevated doses. When Vit C and Vit K3 were combined at a C:K3 ratio of 100:1 and administered to the carcinoma cells, the 50% cytotoxic concentrations (CD50) of the vitamins decreased 10- to 60-fold. Subsequently, the DU145 cells were examined with transmission and scanning electron microscopy (TEM and SEM) following a 1 hour treatment with Vit C, Vit K3, or Vit C/K3 combined at their 50% cytotoxic dose. Our morphological data suggest that vitamin treatment with individual vitamins affects the cytoskeleton, the mitochondria, and other membranous components of the cell. Treatment with the vitamin combination appears to potentiate the effects of the individual vitamin treatment. Specifically, there are abundant necrotic cells. The surviving cells display morphological defects characteristic of cell injury.

Antineoplastic Agents↗
PubMed1995

[Angio-architecture of the colon in Crohn disease and ulcerative colitis. Light microscopy and scanning electron microscopy studies with reference to the morphology of the healthy large intestine].

The etiology and the pathogenesis of the chronic inflammatory bowel diseases known as Crohn's disease and ulcerative colitis have not been defined. Therefore, in this study the main emphasis was placed on description of the pathologic anatomy. Disturbed blood supply and vascular disorders have been discussed as etiopathogenetic factors. The results in the literature are frequently contradictory. For this reason, the vascular system of the colon in Crohn's disease and ulcerative colitis was systematically examined by means of various morphological methods in this study. Microvascular corrosion casting and translucent specimens were taken from operative specimens taken from 12 patients with Crohn's disease and 8 with ulcerative colitis. For comparison, tumor-free parts of 6 colon cancer specimens were examined. The evaluation was done by scanning electron- and/or stereoscopic microscopy. In the presence of chronic inflammatory bowel disease dilatation of the submucosal veins, caliber differences in the tunica muscularis and rarefaction of the penetrating blood vessels were found. In summary, an impairment of the blood flow in the tunica muscularis can be postulated. For the first time, the resulting venous stasis has been described, in contrast to the previously described disturbed arterial blood supply.

Adult↗
PubMed1990

Different phenotypes of cultured microvessel endothelial cells obtained from bovine corpus luteum. Study by light microscopy and by scanning electron microscopy (SEM).

Morphological heterogeneity has not been documented for cultured endothelial cells isolated from the microvascular bed of any organ. As the corpus luteum depends on a rich microvascularization, endothelial cells were dislodged from developing corpora lutea by mechanical dissection followed either by collagenase digestion or by no digestion. Cell separation was carried out by Percoll density centrifugation. Although the yield of intact cells was higher with collagenase treatment than without, successful endothelial cell cultures were only established when cells remained untreated. Viewed by light microscopy after an average lag phase of 10 days, five different phenotypes of endothelial cells were found under similar simple culture conditions: isomorphic epithelioid, polymorphic epithelioid, spindle-shaped, round, and phase-dense phenotypes. Monolayers appeared within 2-4 weeks. After an additional period of 2-4 weeks, tubular forms with a specific pattern were noted for types 1-3, the so-called pseudotubular forms for type 4, and none for type 5. Cell types differed in their cytochemical and immunocytochemical responses. Examined by SEM, type 1 displayed a more conspicuous surface anatomy than type 2. Types 3-5 demonstrated striking cell processes that were characteristic of each type. Tubular forms of types 1 and 2 showed cell borders and a marked increase in surface specializations, whereas tubular forms of type 3 lacked detectable cell borders in the absence of a striking surface anatomy. Pseudotubular forms of type 4 developed no particular spatial organization. Thus, for the first time, morphological evidence is provided that different endothelial cell types are obtained from diverse segments of the microvascular bed.

Acid Phosphatase↗
PubMed1983

Co-ordinated electron microscopy and X-ray studies of glycerinated insect flight muscle. II. Electron microscopy and image reconstruction of muscle fibres fixed in rigor, in ATP and in AMPPNP.

This paper presents electron microscopy, supported by optical diffraction and filtering of images from 100 nm and 25 nm sections, to complement the companion report of X-ray diffraction monitoring (immediately preceding this article) performed on the same insect flight muscle specimens during fixation, dehydration and embedding. Glycerinated Lethocerus fibre bundles initially fixed in rigor, in ATP relaxing buffer, or in 1 mM AMPPNP at 2 degrees C, gave thin-section images from each state whose optical transforms match the distinctive X-ray diffraction patterns from the embedded samples. For rigor and relaxed states, this extends and confirms a long-known correlation between X-ray patterns and EM image regularities. For the AMPPNP state, such correlation is here fully developed for the first time, and involves a new and distinctive EM image pattern of the crossbridge array, clearly different from a previously reported structure in AMPPNP-treated muscles that appears identical to fixed relaxed muscle. We found this latter artifact of 'AMPPNP-relaxed structure' in many fibres from our best AMPPNP specimen, but could identify other fibres which retained the distinctive AMPPNP structure, known to be dominant in this specimen from the X-ray pattern. The true AMPPNP structure shows features of both the ATP-relaxed and rigor crossbridge patterns, not as separate patches, but hybridized uniformly along each filament and throughout each affected sarcomere and fibre. It presents a 14.5 nm repeat of striping and lateral projections along thick filaments, together with variously angled crossbridge attachments to actin that form a 38.7 nm repeat of diffuse chevrons or deltoids replacing the more clearly delinated rigor double chevrons. The associated optical transform has the typical AMPPNP features, that is, it has in common with rigor a strong 19.3 nm layer line and strong second to fourth row line sampling on the 38.7 nm layer line, it has in common with relaxed patterns a strong 14.5 nm meridional and layer line, but it uniquely shows no intensity at the first row line on the 38.7 nm layer line (the 10.3 X-ray reflection), where rigor and relaxed transforms always show high intensity. The processing artifacts which intensify the 10.3 reflection, and produce the weak 19.3 nm layer line (a gain of intensity for ATP but a loss for the AMPPNP state), throughout ATP specimens and in those analogue-treated fibres showing AMPPNP-relaxed structure, might indicate trapping and accumulation of minority populations within the native equilibrium distribution of crossbridge conformations in each nucleotide state.

Adenosine Triphosphate↗
PubMed2002

[Morphogenesis of media calcinosis in Mönckeberg disease. Light microscopy, scanning electron microscopy and roentgen microanalysis findings].

OBJECTIVE: In contrast to granular mediacalcinosis of the aorta, Mönckeberg's disease is characterized by the occurrence of sheet-like calcification. It is usually said that the pathogenesis of this calcification is unknown. MATERIAL AND METHODS: To obtain some insight into the mechanism leading to this calcification, we performed light microscopic, scanning electron microscopic and X-ray microanalysis investigations on femoral arteries from autopsies. RESULTS: By light microscopy preferentially sheet-like calcifications of different size appeared. In the alizarin red S stain in the neighborhood of these compact structures calcified globules were observed. By SEM in the neighborhood of the compact areas calcified granules were found; the compact structures themselves consisted of granules sticking one onto the other. X-ray microanalysis exhibited high contents of calcium and phosphorus in the compact calcifications; they also showed a minor content of magnesium. Isolated granules inside the compact calcifications showed a nearly identical composition, while granules outside in the surrounding media consisted preferentially from calcium and phosphorus, but they exhibited a slight higher magnesium content. CONCLUSIONS: It is concluded that Mönckeberg's media calcification is due to dystrophic calcification. Calcified matrix vesicles from necrotic cells, as it is assumed for the pathogenesis of the calcification of arteriosclerotic plaques (31), are interpreted as precursors of the solid calcifications which may develop by confluence and sticking one onto the other of calcified globules.

Aged↗
PubMed1983

Localization of gallium in tumor cells. Electron microscopy, electron probe microanalysis and analytical ion microscopy.

The incorporation of gallium in tumor cells in vitro and in solid tumors was studied with electron microscopy and two microanalytical techniques. It was thus possible (1) to directly prove that gallium is concentrated in lysosomes of tumor cells; (2) to demonstrate that in these lysosomes, gallium is precipitated with phosphorus; and (3) to propose a mechanism of gallium concentration in tumor cells; in this mechanism, the accumulation of gallium as phosphate salts in lysosomes is directly related to the acid phosphatase activity of these organelles.

Animals↗
PubMed1991

Improved detection of HSV by electron microscopy in clinical specimens using ultracentrifugation and colloidal gold immunoelectron microscopy: comparison with viral culture and cytodiagnosis.

Three tests were compared to diagnose herpes virus infection: electron microscopy (EM), viral culture (VC) and cytodiagnosis (Tzanck smear). The study comprised 67 patients with skin or mucous membrane lesions suggestive of herpes simplex virus (HSV) infection. The sensitivity of EM increased 25% after virus concentration by ultracentrifugation. Herpes virus infection was confirmed in 55 of the 67 cases by EM or VC or both. EM detected 53 herpes virus-positive lesion samples of which 14 were not detected by VC; only two lesion samples that were herpes virus-positive in VC were not detected by EM. The sensitivities of EM, VC, and Tzanck smear for the group of 55 herpes virus-positive cases were 96%, 75% and 76%, respectively. The specificity of the Tzanck smear was 83% (prevalence 82%). Colloidal gold immuno-EM was used to rapidly type HSV-1, HSV-2 and varicella zoster virus (VZV) present in skin and mucous membrane lesions in less than 4 h. Immuno-EM was able to detect antiviral antibodies on viral envelopes and viral cores in lesion samples with negative VC. Antiviral antibodies do not interfere with typing of herpes viruses by immuno-EM. It is suggested that formation of viral immune complexes and inactivation of virus particles by antibodies may have caused a negative VC. Improved EM is discussed for its applicability to special cases that cannot rely on VC and cytodiagnosis or when rapid diagnosis is required.

Adolescent↗
PubMed1999

Virtual microscopy: high resolution digital photomicrography as a tool for light microscopy simulation.

Recent advances in microcomputers and high resolution digital video cameras provide pathologists the opportunity to combine precision optics with digital imaging technology and develop new educational and research tools. We review recent advances in virtual microscopy and describe techniques for viewing digital images using a microcomputer-based workstation to simulate light microscopic examination, including scanning at low power to select features of interest and zooming to increase magnification. Hardware and software components necessary to acquire digital images of histological and cytological slides, and closely simulate their examination under a light microscope are discussed. The workstation is composed of a MicroLumina digital scanning camera (Leaf Systems, Southborough, MA), light microscope (Olympus Optical Co., Lake Success, NY), Pentium (Intel Corp., Santa Clara, CA) 166 MHz microcomputer configured with 64 megabytes of random access memory (RAM), a MGA Millenium Powerdesk graphics card (Matrox Graphics, Inc., Montreal, Canada) and Photoshop software (Adobe Systems Inc., San Jose, CA) running in a Windows 95 (Microsoft Corp., Redmond, WA) environment. Images with spatial resolutions of up to 2700 x 3400 pixels in 36-bit color, can be displayed simultaneously as distinct images in a montage, or merged into a single composite image file to highlight significant features of a histological or cytological slide. These image files are saved in Joint Photographers Experts Group (JPEG) format using compression ratios of up to 80:1 without detectable visual degradation. The advantages and technical limitations of various workstation components are addressed and applications of this technology for pathology education, proficiency testing, telepathology, and database development are discussed.

Forecasting↗
PubMed2001

Integration of Raman microscopy, differential interference contrast microscopy, and attenuated total reflection Fourier transform infrared spectroscopy to investigate chlorhexidine spatial and temporal distribution in Candida albicans biofilms.

Two spectroscopic techniques, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and Raman microscopy (RM), were used to characterize transport of chlorhexidine digluconate (CHG) in Candida albicans (CA) biofilms. Different (volumetric) regions of the biofilm are sampled by these two vibrational spectroscopies making them complementary techniques. Simple mathematical models were developed to analyze ATR-FTIR and RM data to obtain an effective diffusion coefficient describing transport through CA biofilms. CA biofilms were composed primarily of yeast and hyphal forms, with some pseudohyphae. Upper regions of biofilms that had become confluent, (i.e., biofilms that completely covered the germanium (Ge) substratum) were composed primarily of a tangled mass of hyphae with openings between germtubes about 10 to 50 microm across. Quantitative analysis of ATR-FTIR kinetic data curves indicated that the effective diffusion coefficient for transport of CHG through confluent biofilms about 200-microm thick was reduced 0.1 to 0.3 times compared to the diffusion coefficient for CHG in water. Effective diffusion coefficients obtained from analysis of RM data were consistently higher than those indicated by ATR-FTIR data suggesting that transport is more hindered in regions near the base of the biofilm than in the outer layers. Analysis of both ATR-FTIR and RM data obtained from thicker films indicated that adsorption of CHG to biofilm components was responsible for a substantial portion of the transport limitation imposed by the biofilm. Comparison of ATR-FTIR and RM data for both types of biofilms indicated that sites of CHG adsorption were more concentrated in the interfacial region than in the bulk biofilm. Comparison of results for ATR-FTIR and RM measurements suggests that these relatively thick CA biofilms can be modeled, for purposes of predicting transport, approximately as a homogeneous thin planar sheet. Thus, these biofilms offer a relatively tractable model system for initial investigations of the relation between antimicrobial transport and kinetics of antimicrobial action.

Anti-Bacterial Agents↗
PubMed1994

Human cumulus cell complexes studied in vitro by light microscopy and scanning electron microscopy.

Various researchers describe the morphology of cumulus cells (CC) in vitro, but few have investigated their behaviour on plastic. Knowledge concerning the behaviour of human CC could be useful in improving the success of in vitro fertilisation procedures. This study aimed to describe the morphology and behaviour of CC in vitro and to investigate movement on a collagen-coated substrate. Following collection some cumulus were mechanically dissected from those surrounding the oocyte. Cumulus aggregates were cultured over 24 h using Earle's medium supplemented with 8% albumin. Substrata were plastic coverslips coated with collagens I, IV, or mixed collagens. Cumulus cultured over corresponding time periods on uncoated coverslips served as controls. Specimens were fixed and prepared for scanning electron microscopy. Over 24 h the controls began exhibiting the morphological features associated with cell movement: cell surface protrusions changed from blebs to microridges, lamellipodia and leading lamellae; cell shape altered from rounded and upright, to flattened. Extracellular matrix (ECM) transformed from a thick, sheet-like substance to a thin, fibrous material. By 24 h, cells contacting ECM remained rounded showing few features of movement. Collagens enhanced attachment of CC as a monolayer on the substrate. Cell morphology varied according to the collagen type used. On mixed collagens, cells attached rapidly, appearing to be predominantly non-motile. On collagen type I there was less attachment of cells but increased motility. On collagen type IV there was decreased attachment and the cells remained spherical. In conclusion, collagens enhance the settling of cumulus cells on a plastic substrate and the cells exhibit some specificity in attaching to collagens.

Adult↗
PubMed2004

Scanning electron microscopy (SEM) and optical microscopy: effects of Er:YAG and Nd:YAG lasers on apical seals after apicoectomy and retrofill.

OBJECTIVE: This study evaluated the dentinal and marginal permeability of the cut surface after apicoectomy, treatment and retrocavity preparation with Er:YAG and Nd:YAG lasers. Furthermore, scanning electron microscopy (SEM) analysed the morphological alteration of dentin caused by laser irradiation through an optical fiber. BACKGROUND DATA: Numerous studies have shown the beneficial effects of laser treatment upon sealing dental apex, avoiding the changes of organic fluids, microorganisms and their by-products between the root canal system and periapex. MATERIALS AND METHODS: Twenty-four extracted and endodontically treated teeth were divided into three groups: GI, apices were resected with Er:YAG laser (350 mJ; 4 Hz) treatment of cut dentinal surface and retrocavity were lased with this same laser (120 mJ; 4 Hz; bur 2051) using the optical fiber 50/10; GII, apicoectomy was performed similar to GI, however the cut dentinal surface was treated with Nd:YAG laser through optical fiber, as well as the retrocavity preparation (100 mJ; 15 Hz; 1.5 W); and GIII (control group), high speed burs were used. RESULTS: Analysis of methylene blue dye penetration into dentin demonstrated that the specimens of the groups irradiated with laser showed to have lower infiltration indices than the control group. These results were compatible with structural and morphological injuries, evidenced by SEM. CONCLUSION: Under the conditions of the present study, apicoectomy using Er:YAG laser, followed by dentinal surface irradiation and retrocavity preparation with Nd:YAG laser, showed to be an alternative clinical tool able to reduce the dentinal permeability.

Humans↗
PubMed1983

Chondroitin sulfate facilitates an acrosome reaction in bovine spermatozoa as evidenced by light microscopy, electron microscopy and in vitro fertilization.

Bovine epididymal spermatozoa were incubated for 22 h in a modified Tyrode's medium. The percentages of sperm exhibiting an acrosome reaction were determined morphologically after fixing and staining specimens. The addition of chondroitin sulfate A (CS-A) significantly increased the incidence of acrosome reaction. When observed by electron microscopy, acrosome-reacted sperm had undergone vesiculation of the plasma and outer acrosomal membranes. Sperm incubated in the presence of CS-A demonstrated a significantly higher incidence of vesiculation when compared to the controls. Additionally, rates of in vitro fertilization of bovine oocytes were significantly elevated when sperm and ova were exposed to CS-A. These results suggest that glycosaminoglycans in the female reproductive tract may be responsible for some of the biochemical changes associated with fertilization, and a light microscope procedure can be used to assess occurrence of the acrosome reaction.

Acrosome↗
PubMed1983

Histiocytoid hemangioma with features of angiolymphoid hyperplasia and Kaposi's sarcoma. A study by light microscopy, electron microscopy, and immunologic techniques.

We examined by light and electron microscopy 99 vascular lesions removed on 17 occasions over a 2-year period from a 55-year-old black man. The lesions all showed histologic features of a vascular neoplasm composed of enlarged "histiocytoid" endothelial cells and overlapping features of angiolymphoid hyperplasia with eosinophilia and Kaposi's sarcoma. An apparently unique feature was early loss of melanin from the overlying epidermis and a mononuclear inflammatory-cell infiltrate. The patient also had an abnormal immunologic state very similar to that seen in homosexuals with Kaposi's sarcoma.

Endothelium↗