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PubMedDate not supplied

[Pathomorphology of the endocardium and myocardium in the heart injury].

Light, polarization, luminescent microscopy, phase contrast, special staining methods and scanning electron microscopy were used for studying sections and fragments of the endocardium and myocardium from 123 patients who had died of heart contusion and ischemic heart disease and from 50 rats with experimental heart contusion. The morphological classification of heart contusion and differential-diagnostic table of myocardial alterations due to contusion of the heart and ischemic heart disease are proposed to facilitate pathomorphological diagnosis of heart contusion. The classification of pathomorphological signs in heart contusion is presented.

Adolescent↗

PubMed1988

Cellular morphology and distribution on a stretching blood-material interface.

In order to investigate the interactions of cellular elements and protein on constantly deforming (fatiguing) blood contact surfaces, a series of ex vivo canine arteriovenous shunt experiments were conducted. While fresh blood was flowing through Silastic tubing shunts, portions of the tubing were stretched 20 to 60% at a frequency of 20 to 90 cycles per minute for 10 to 90 min. The surfaces of the tubing that were stretched were compared with control tubing surfaces taken from the arterial side of the test segment using scanning electron microscopy and interference phase contrast microscopy. Approximately the same number of platelets were deposited on the stretched as on the unstretched portions of the tubing in the ten minute experiments. On the control portions of the tubing, the platelets were deposited singly and uniformly in what appeared to be a fairly inactivated state. On the stretched tubing, more pseudopod extension and aggregation was observed. In these preliminary experiments, no differences were noted as a function of frequency of stretch. As the blood contact time and the percent stretch were increased, only nonuniform, scattered aggregations of platelets, and platelets mingled with fibrin were seen. Significant numbers of spread white blood cells were observed on many of the segments of Silastic tubing stretched 20% for as short a time as 15 min. Granulocytes have occasionally been reported on less hemocompatible biomaterials after exposure to canine blood. This helps to confirm that substrate stretching of 20-60% had an adverse effect on the blood compatibility of the Siliastic tubing.

Animals↗

PubMedDate not supplied

Uptake of fluorochrome-labelled exotoxins by different cell types in culture.

The uptake of diphtheria toxin and of Staphylococcus alpha-toxin by two different human cell types cultured in vitro (the HEp-2 continuous cell line and human adult hepatocytes) was studied by fluorescence microscopy and phase-contrast microscopy. The behavior of these two bacterial exotoxins was quite different. Diphtheria toxin was incorporated into cells by pinocytosis, whereas alpha-hemolysin penetrated into the cytoplasm probably through lesions in the cell membrane. In addition, the penetration of diphtheria toxin into the cells was not inhibited by specific antiserum, whereas anti-alpha-haemolysin inhibited the penetration of alpha-tpxin through the cell membrane. The significance of these findings is discussed.

Animals↗

PubMed1998

Morphological changes induced by prostaglandin E in cultured rat osteoblasts.

Prostaglandin E (PGE)-induced morphological changes of osteoblasts and its possible mechanisms were investigated in cultured calvaria and isolated osteoblasts from long bone fragments of neonatal rats. The control osteoblasts, either on the calvaria or isolated from the long bone fragments, were flat, polygonal in shape, and arranged in a monolayer under scanning electron microscopy (SEM) or phase contrast microscopy. Treatment with 1 mumol/L of prostaglandin E2 (PGE2, 2 h) caused these bone cells to contract a soma, whereas 10 and 100 mumol/L PGE2 (2 h) caused 18%-30% of the bone cells to elongate and expose the undersurface. Incubation of the cultured osteoblasts with PGE2 at different time periods showed a bell-shaped pattern with the optimal response at 2 h of incubation. A similar reaction can be induced by treatment with prostaglandin E1 (PGE1) or dibutyryl cyclic adenosine monophosphate (DBcAMP) in combination with 3-isobutyl-1-methylxanthine (IBMX). Furthermore, we assessed the percentage of responsive isolated bone cells to investigate interactions with other agents. The morphological changes induced by PGEs were inhibited by H-8, a protein kinase inhibitor. On the other hand, elevated intracellular calcium enhanced the PGE-induced morphological changes. Fluorescence labeling showed that PGEs caused the breakdown of the actin microfilaments, but spared the microtubules and vimentin filaments in the isolated osteoblast-like cells. These results suggest that the morphological changes of osteoblasts induced by PGEs may be related to the intracellular cAMP and calcium levels.

1-Methyl-3-isobutylxanthine↗

PubMed1997

Development of a cell line from skin of goldfish, Carassius auratus, and effects of ascorbic acid on collagen deposition.

Growth characteristics and collagen expression were investigated in GFSk-S1, a cell line derived from the skin of an adult goldfish (Carassius auratus). These cells are anchorage dependent, grow well in Leibovitz-15 medium with 10% fetal bovine serum, and have been subcultured routinely for 5 years. Cells at various passages have been successfully cryopreserved and thawed. GFSk-S1 cells show mainly a fibroblastic morphology at low density, but at confluence islands of epithelial-shaped cells appear among the fibroblastic cells. The cells require little maintenance, and cultures have been kept viable for more than 3 months without medium changes. Although best growth was observed at room temperature, cell proliferation still occurred at 28 degrees C, and a subline was maintained and passaged for over a year at 25 degrees C. Cells were exposed to various concentrations of ascorbic acid, and its effects on collagen secretion were monitored by light and electron microscopy. Under phase-contrast microscopy, confluent GFSk-S1 cells exposed to ascorbic acid at 50 micrograms/ml showed distinct development of fibres as early as 3 days after treatment. Histochemical staining for collagen demonstrated a thick network of fibres under a monolayer of ascorbic acid-treated GFSk-S1 cells, and observation by transmission electron microscopy showed collagen fibres with typical banding pattern. This cell line appears to show a stable genotype, as collagen expression was induced at all passages. GFSk-S1 could be useful for studies not only of regulation of protein synthesis, but also of cell differentiation and wound healing.

Animals↗

PubMed2000

Exposures to asbestos arising from bandsawing gasket material.

A simulation of bandsawing sheet asbestos gasket material was performed as part of a retrospective exposure evaluation undertaken to assist in determining causation of a case of mesothelioma. The work was performed by bandsawing a chrysotile asbestos (80%)/neoprene gasket sheet with a conventional 16-inch woodworking bandsaw inside a chamber. Measurements of airborne asbestos were made using conventional area and personal sampling methods, with analysis of collected samples by transmission electron microscopy (TEM) and phase contrast microscopy (PCM). These were supplemented by qualitative scanning electron microscopy (SEM) examinations of some of the airborne particles collected on the filters. In contrast with findings from studies examining manual handling (installation and removal) of gaskets, airborne asbestos concentrations from this operation were found to be well above current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) (eight-hour time-weighted average [TWA]) and excursion limit (30-minute) standards. Although some "encapsulation" effect of the neoprene matrix was seen on the particles in the airborne dust, unencapsulated individual fiber bundles were also seen. Suggestions for the implications of the work are given. In summary, the airborne asbestos concentrations arising from this work were quite high, and point to the need for careful observation of common sense precautions when manipulation of asbestos-containing materials (even those believed to have limited emissions potential) may involved machining operations.

Asbestos↗

PubMed1985

Effect on growth curve patterns of brief exposure of bacteria to different concentrations of beta-lactam antibiotics.

The effect of a brief beta-lactam action on a bacterial culture has been studied by combining the use of a high performance photometer with phase contrast microscopic examination. After exposure of the culture with the antibiotic, the growth curves presented in logn OD have shown the importance of the pre-lytic increase in OD (PIOD). Using Escherichia coli a study of the PIOD values allowed us to separate the beta-lactam antibiotics studied into two groups: those whose PIOD were concentration-dependent (ampicillin, carbenicillin, ticarcillin, moxalactam, ceftazidime, cefsulodin, cefotaxime) and those whose PIOD were concentration-independent (or weakly dependent) (azlocillin, mezlocillin, piperacillin). When the PIOD was independent of the concentrations, long filaments were observed by phase contrast microscopy. Using Pseudomonas aeruginosa, all the antibiotics studied produced PIOD values that were barely dependent of the concentrations, and long filaments were observed by phase contrast microscopy. Study of the lag of regrowth in the post antibiotic period using a beta-lactamase technique showed that, if the PIOD was hardly concentration dependent, so was the lag of regrowth.

Ampicillin↗

PubMed1999

Graft of autologous fibroblasts in gingival tissue in vivo after culture in vitro. Preliminary study on rats.

Several grafting techniques and guided tissue regeneration techniques (GTR) have been well-developed in periodontal surgery. However, these techniques could induce pain and side effects, such as a gingival recession during the healing period following the therapy. The graft of a small autologous connective tissue, using non-invasive surgical techniques could yield several benefits for the patients. Our preliminary study explores the feasibility of collecting healthy gingival tissues, culturing them in vitro to amplify rat gingival fibroblasts (RGF) and inoculating the obtained cells into autologous rat gingival tissues in vivo. Gingival tissues samples were cultured as explants as described by Freshney et al. and Adolphe. Confluent cells surrounding explants were detached after 7 d of culture from Petri dishes using 0.05% trypsin and designated "first transferred cells" (T1). At the third passage (T3), cells cultured as monolayer were either examined under microscopy--phase contrast, scanning, or transmission electron--or numerated after trypan blue exclusion test. Autologous RGF labelled with fluorochrome were inoculated at the vestibular and palatine site of gingival tissue close to the superior incisors. In this preliminary study, 12 Wistar rats were used; for each, 2 biopsies were dissected and fixed for phase contrast or fluorescence microscopy. On d 1, 3 and 7 after injection in rat gingival tissues, fluorochrome-labelled cells could be detected in all these.

Animals↗

PubMed1994

Mapping of intracellular localization domains and evidence for colocalization interactions between the IE110 and IE175 nuclear transactivator proteins of herpes simplex virus.

Transcriptional regulation by the IE175 (ICP4) and IE110 (ICP0) phosphorylated nuclear proteins encoded by herpes simplex virus (HSV) appears to be a key determinant for the establishment of successful lytic cycle infection. By indirect immunofluorescence in transient DNA transfection assays, we have examined the intracellular distribution of deletion and truncation mutants of both IE175 and IE110 from HSV-1. Insertion of short oligonucleotides encoding the basic amino acid motifs 726-GRKRKSP-732 from IE175 and 500-VRPRKRR-506 from IE110 into deleted cytoplasmic forms of the two proteins restored the karyophilic phenotype and confirmed that these motifs are both necessary and sufficient for proper nuclear localization. Analysis of IE110 deletion mutants and a panel of IE110/IE175 hybrid proteins was also used to evaluate the characteristic IE110 distribution within nuclear punctate granules as seen by immunofluorescence and phase-contrast microscopy. The phase-dense punctate pattern persisted with both large C-terminal truncations and deletions of the Cys-rich zinc finger region and even with a form of IE110 that localized in the cytoplasm, implying that the punctate characteristic is an intrinsic property of the N-terminal segment of the IE110 protein. Transfer of the full IE110-like punctate phenotype to the normally uniform diffuse nuclear pattern of the IE175 protein by exchange of the N-terminal domains of the two proteins demonstrated that the first 105 to 244 amino acids of IE110 represent the most important region for conferring punctate characteristics. Surprisingly, cotransfection of a wild-type nuclear IE175 gene together with the IE110 gene revealed that much of the IE175 protein produced was redistributed into a punctate pattern that colocalized with the IE110-associated punctate granules seen in the same cells. This colocalization did not occur after cotransfection of IE110 with the IE72 (IE1) nuclear protein of human cytomegalovirus and therefore cannot represent simple nonspecific trapping. Evidently, the punctate phenotype of IE110 represents a dominant characteristic that reveals the potential of IE110 and IE175 to physically interact with each other either directly or indirectly within the intracellular environment.

Amino Acid Sequence↗

PubMed2006

[Neonatal respiratory distress caused by primary ciliary dyskinesia].

Two newborns, both boys, presented with unexplained respiratory distress. One developed recurrent pneumonias in the first neonatal week and was diagnosed with primary ciliary dyskinesia at the age of 2.5 years. The other had respiratory problems besides a situs inversus totalis and was diagnosed with primary ciliary dyskinesia in the neonatal period. Although 65-90% of children with primary ciliary dyskinesia present with neonatal respiratory distress, the disease is often diagnosed after a considerable delay. Primary ciliary dyskinesia should be considered in newborns with unexplained respiratory problems and in children with recurrent respiratory problems. The disease is diagnosed by taking a nasal brush biopsy of the cilia and examining it using electron microscopy or using phase contrast microscopy. Early diagnosis and adequate treatment may prevent further lung damage.

Ciliary Motility Disorders↗

PubMed1994

Differentiation of glomerular and non-glomerular hematuria in children by measurement of mean corpuscular volume of urinary red cells using a semi-automated cell counter.

Urine samples from 110 children and adolescents with micro- or macrohematuria were compared using phase-contrast microscopy and a semi-automated cell counter to differentiate glomerular from non-glomerular hematuria. Glomerular hematuria, defined by clinical criteria from biopsy and standard chemical evaluation, was observed in 73 patients (group 1): non-glomerular hematuria was found in 37 patients (group 2). The latter group underwent urological operation and had normal urine before operation. Mean corpuscular erythrocyte volume (MCVU) and percent of dysmorphic erythrocytes were determinated. To exclude the influence of mean erythrocyte volume of blood erythrocytes (MCVB), MCVB was determined and additionally the quotient of MCVU/MCVB was calculated (MCVUB). The percentage of dysmorphic erythrocytes differed significantly between the two groups ((75 +/- 13% in group 1 versus 38 +/- 27% in group 2 (mean +/- SD); p < 0.01), MCVU (34.0 +/- 11.1 fl in group 1 versus 55.5 +/- 16.3 fl in group 2; p < 0.01) and MCVUB (0.41 +/- 0.14 in group 1 versus 0.67 +/- 0.20 in group 2; p < 0.01). When glomerular hematuria was defined on the basis of more than 80% dysmorphic erythrocytes, the sensitivity of phase-contrast microscopy was 0.52, specificity versus 0.96 and efficiency 0.64. When glomerular hematuria was defined as < 50 fl MCVU, sensitivity was 0.92, specificity 0.57 and efficiency 0.80 and as < 0.06 MCVUB, sensitivity was 0.89, specificity 0.62 and efficiency 0.80. The correlation coefficient between MCVU and dysmorphic erythrocytes was -0.71 (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed2000

[Laboratory diagnosis of Acanthamoeba keratitis].

OBJECTIVE: To find a rapid method for diagnosing Acanthamoeba keratitis and identifying Acanthamoeba. METHODS: 10% potassium hydroxide (KOH) wet-mount preparations, Acanthamoeba culture, inverted phase contrast microscopy, and pathological examination using H. E. staining and PAS staining. RESULTS: Using corneal scrapings and corneal materials obtained from surgery, 7 cases and 5 cases of Acanthamoeba keratitis were diagnosed by 10% KOH wet-mount preparations. 6 strains of Acanthamoeba were isolated in corneal materials of 6 cases by protozoa culture method. The cysts, trophozoites and pseudopods on the trophozoites of Acanthamoeba were directly observed under the inverted phase contrast microscope. The cysts and trophozoites of Acanthamoeba were seen by H. E. staining and PAS staining with 20 h. CONCLUSION: Acanthamoeba keratitis could be rapidly diagnosed by 10% KOH wet-mount preparations and inverted phase contrast microscopy. Acanthamoeba organisms could be directly observed and identified under inverted phase contrast microscope.

Acanthamoeba↗

PubMed1986

Progressive microscopical changes in the closed system incubated rat lens.

A phase contrast microscopy investigation of 18 cultured rat lenses was undertaken. After an initial latent phase, the outline of the epithelial cells anteriorly became enhanced and posteriorly the lens fibers began to swell. This was followed by an anterior and posterior subcapsular accumulation of fluid, epithelial swelling and formation of posterior subcapsular vacuoles. At the end of the incubation period, no increase in the light dissemination from the lens was observed. It is concluded, that, when these changes are taken into account, the closed system cultured rat lens is an excellent and applicable model for studying the induced progressive changes in the microstructure of the living lens due to different agents.

Animals↗

PubMed1979

Morphology of spermatogenic arrest in man.

Spermatogenic arrest in man was studied by transillumination, phase contrast microscopy, and conventional histology. The spermatogenic arrest occurred at the late pachytene stage, and the degeneration of the germ cells could be studied more accurately with phase contrast microscopy of living cells than with conventional histology. The Sertoli cells rapidly phagocytosed the degenerating cells, which could be seen on transillumination as dark spots along the whole length of the tubule.

Follicle Stimulating Hormone↗

PubMed1994

Levels of workplace exposure.

A brief description was presented of the evolution of workplace exposure monitoring. Measurements began in the 1930s and developed through particle counting to the introduction of the membrane filter, light microscope method in the mid-1960s. It is important to be aware that most data from the past were collected in relation to workplace control. The membrane filter phase contrast microscope method provides an index of exposure. Fibres with diameters less than 0.2 microns are unlikely to be counted. The method is not capable of analysing individual fibre types and consequently all fibres are counted. There have been several changes to the detail of the membrane filter method. The possible effect of these changes were presented. The Asbestos International Association (AIA) has implemented a fibre counting performance trial and also an annual return of workplace monitoring data. A WHO project is in progress with the objective of harmonizing the membrane filter method for fibre counting of all fibre types using phase contrast microscopy.

Asbestosis↗

PubMed2005

Composition dependence of vesicle morphology and mixing properties in a bacterial model membrane system.

We have determined the mixing properties and lamellar organization of bacterial membrane mimetics composed of 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) and -phosphatidylglycerol (POPG) at various molar ratios applying differential scanning calorimetry, small and wide-angle X-ray scattering, as well as optical phase contrast microscopy. Combining the experimental thermodynamic data with a simulation of the liquidus and solidus lines, we were able to construct a phase diagram. Using this approach, we find that the lipids mix in all phases non-ideally in the thermodynamic sense. As expected, pure POPE assembles into multilamellar and pure POPG into unilamellar vesicles, respectively, which are stable within the studied temperature range. In contrast, mixtures of the two components form oligolamellar vesicles consisting of about three to five bilayers. The layers within these oligolamellar liposomes are positionally correlated within the gel phase, but become uncorrelated within the fluid phase exhibiting freely fluctuating bilayers, while the vesicles as a whole remain intact and do not break up into unilamellar forms. X-ray, as well as DSC data, respectively, reveal a miscibility gap due to a lateral phase segregation at POPG concentrations above about 70 mol%, similar to previously reported data on mixtures composed of disaturated PEs and PGs. Hence, the existence of a region of immiscibility is a general feature of PE/PG mixtures and the mixing properties are dominated by PE/PG headgroup interactions, but are largely independent of the composition of the hydrocarbon chains. This is in accordance with a recent theoretical prediction.

Bacteria↗

PubMedDate not supplied

Imaging of cell/substrate contacts on polymers by total internal reflection fluorescence microscopy.

A simplified model of total internal reflection fluorescence (TIRF) emission of fluorescently labeled cell membranes [Reichert, W. M.; Truskey, G. A. J. Cell Sci. 1990, 96, 219-230] was used to determine the topography of the cell membrane in apposition to a polymer-coated surface. The homopolymer substrates were spun cast films of hydrophilic poly(hydroxyethyl methacrylate) (polyHEMA) or hydrophobic poly(ethyl methacrylate) (polyEMA). Bovine aortic endothelial cells (BAEC) on preadsorbed fibronectin polymer substrates were either plated for 24 h, fixed, labeled, and examined by TIRF microscopy (TIRFM) and phase-contrast microscopy or plated for 2 h and tested for their adhesion strength in a parallel-plate flow chamber. BAEC attached to polyHEMA showed no evidence of focal contact formation. However, BAEC attached to polyEMA were well spread and showed an array of focal contacts. TIRFM data were transformed to construct a detailed topographical map of relative cell/substrate separation distances. Virtually all of the BAEC plated to polyHEMA were sheared from the surface when subjected to a 50 dyn/cm2 burst of laminar flow, whereas only 10% of the BAEC were sheared from the polyEMA surface. These data suggest that the polyHEMA and polyEMA surface properties (e.g., hydrophobicity) correlate with the presence of BAEC focal contacts and the BAEC attachment strength.

Animals↗

PubMed1972

Physical studies of isolated eucaryotic nuclei.

The degree of chromatin condensation in isolated rat liver nuclei and chicken erythrocyte nuclei was studied by phase-contrast microscopy as a function of solvent pH, K(+) and Mg(++) concentrations Data were represented as "phase" maps, and standard solvent conditions selected that reproducibly yield granular, slightly granular, and homogeneous nuclei Nuclei in these various states were examined by ultraviolet absorption and circular dichroism (CD) spectroscopy, low-angle X-ray diffraction, electron microscopy, and binding capacity for ethidium bromide Homogeneous nuclei exhibited absorption and CD spectra resembling those of isolated nucleohistone. Suspensions of granular nuclei showed marked turbidity and absorption flattening, and a characteristic blue-shift of a crossover wavelength in the CD spectra. In all solvent conditions studied, except pH < 2 3, low-angle X-ray reflections characteristic of the native, presumably superhelical, nucleohistone were observed from pellets of intact nuclei. Threads (100-200 A diameter) were present in the condensed and dispersed phases of nuclei fixed under the standard solvent conditions, and examined in the electron microscope after thin sectioning and staining Nuclei at neutral pH, with different degrees of chromatin condensation, exhibited similar binding capacities for ethidium bromide. These data suggest a model that views chromatin condensation as a close packing of superhelical nucleohistone threads but still permits condensed chromatin to respond rapidly to alterations in solvent environment.

Animals↗