SEARCH · Search PubMed

Results for “Microscopy, Interference”

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.

SourceResearch connectionFrom yearThrough year

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

At least 235 records · Page 13Linked to original sources

PubMed2001

Controlled cell deformation produces defined areas of contact between cells and ligand-coated surfaces.

A method which allows precise control of the time of initiation and the area of contact of T cells with immobilized ligands has been developed. Cells are trapped in an asymmetric film that can be quantitatively thinned by reducing the film's capillary pressure. Ligands adsorbed to the base of the apparatus are forced into close contact with the cells as the air-liquid interface is drawn down. Using interference microscopy and microbeads to indicate the film height, the amount of thinning can be controlled to within 1 microm. In this study, this system was used to produce contact areas of 182 and 356 microm2 between T cells and anti-CD3 coated surfaces. These contact areas were measured using fluorescent dye exclusion microscopy. This apparatus can be used for quantitative studies of T cell activation, as is reported in Patrick et al., J. Immunol. Method. 24:97-108, 2000.

Animals↗

PubMed1966

Structure and organization of the living mitotic spindle of Haemanthus endosperm.

New details of mitotic spindle structures in the endosperm of Haemanthus katherinae (Bak) have been demonstrated by differential interference microscopy. Spindle fibers are clearly seen in the living spindle extending from the kinetochores to the polar region. Individual spindle fibers consist of a bundle of smaller filaments which diverge slightly from the kinetochore and intermingle with filaments from other spindle fibers as they approach the polar region. The degree of intermingling increases during metaphase and anaphase. The chromosomes stop moving when the spindle fibers are still 5 to 10microns long; then the fibers disappear. These observations explain some aspects of spindle movements which were difficult to reconcile with earlier concepts of spindle organization.

Cell Division↗

PubMed1982

Refractive index of the fly rhabdomere.

The refractive index and the diameter of the fly rhabdomere were determined by comparing the experimental results derived from interference microscopy with the results of theoretical study on the scattering of plane waves by a homogeneous, isotropic cylindrical dielectric rod. It was found that the refractive index of the isolated rhabdomere of Calliphora erythrocephala is 1.363 +/- 0.003 in an area of the rhabdomere where its diameter is calculated to be 1.32 +/- 0.04 micrometers.

Animals↗

PubMed1980

Fibrous waveforms or crimp in surface and subsurface layers of hyaline cartilage maintained in its wet functional condition.

The structural features of hyaline cartilage maintained in its wet functional condition have been examined using the technique of Nomarski interference microscopy. The collagenous arrays and associated chondrocytes in both the extreme superficial layers and in the deeper subsurface zones were satisfactorily imaged with this technique. Most significantly the collagen fibers were observed to possess a geometric waveform or "crimp" of varying acuteness and the role of this crimp is discussed in relation to the mechanical and biological function of the tissue. It is clear from these wet tissue studies that the fibrous layout in hyaline cartilage is considerably more "disciplined" than has been previously recognized from morphological data obtained using more indirect experimental techniques involving prepared histological sections or scanning and transmission electron microscopy.

Animals↗

PubMed1991

The density of the cell sap and endoplasm of Nitellopsis and Chara.

We measured the densities of the cell sap, endoplasm and cell wall of Nitellopsis obtusa and Chara corallina using interference microscopy, refractometry, immersion refractometry, equilibrium sedimentation and chemical microanalysis techniques. These values are important for the determination of many rheological properties of the cytoplasm as well as for understanding buoyancy regulation, dispersal mechanisms and how cells respond to gravity. The average densities of the cell sap, endoplasm and cell wall are 1,006.9, 1,016.7 and 1,371 kg m-3 for Nitellopsis and 1,005.0, 1,013.9, and 1,355.3 kg m-3 for Chara.

Cell Wall↗

PubMed2004

[Modern methods for studying the surface of titanium implants (literature review)].

Studies of the coatings found on the surface of titanium implants employed in oral surgery are indispensable for understanding the interactions between the organism and the implant. This paper surveys the theory and practical applicability of the methods most frequently applied to study the surface structure and composition of the material. Detailed accounts are given of various structure investigation methods: scanning electron microscopy, stereo scanning electron microscopy, X-ray diffraction, atomic force microscopy and interference microscopy; and of various composition investigation methods: secondary ion mass spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy; and also of the corrosion procedures for the study of electrochemical behaviour.

Animals↗

PubMed1992

A new morphological classification of urinary erythrocytes for differential diagnosis of glomerular hematuria.

A new morphological classification of urinary erythrocytes was instituted in order to differentiate glomerular from urological hematuria. One hundred and thirteen hematuric patients including 73 glomerular and 40 urological disease patients were examined. The former group consisted of IgA nephropathy (n = 45), lupus nephritis (6), membrano-proliferative glomerulonephritis (5), non-IgA mesangial proliferative glomerulonephritis (4), Henoch-Schoenlein purpura nephritis (4), membranous nephropathy (4), endocapillary proliferative glomerulonephritis (3), and minimal change nephrotic syndrome (2). The latter group included bladder cancer (n = 15), renal calculi (15), prostate cancer (3), urethral cancer (1) and post-transurethral resection (6). In each urine sample, 100 urinary erythrocytes were observed under differential interference microscopy and classified into 10 concretely defined shapes (5 "glomerular" and 5 "urological" shapes) and unclassified shapes. Using percentage of "glomerular" shape erythrocytes and setting the cut-off at 15%, 90.4% of sensitivity and 97.5% of specificity for the diagnosis of glomerular disease were obtained. When percentage of one specific shape (G1), [i.e. doughnut-like cell with one or more blebs] was used at a cut-off of 1%, sensitivity and specificity were 89.0% and 95.0% respectively. These results were satisfactory as compared with most previous reports. Moreover, our classification is so concrete that it is more objective, accurate, and easily understandable, even for beginners. Distinct shape "G1" is particularly important for morphological investigation of hematuria.

Diagnosis, Differential↗

PubMed1975

Encephalitis in suckling rats induced with rat cytomegalovirus.

Encephalitis has been induced in suckling rats by intracerebral inoculation of rat cytomegalovirus. This agent has been carried through five animal passages without changes in virulence. Principal sites of viral attack were the meninges and ependyma with limited parenchymal invasion from these sites. Characteristic features of cytomegalovirus disease observed included cytomegaly, formation of nuclear and cytoplasmic inclusions, and polykaryocytosis. Fundamental tinctorial and optical differences were noted between nuclear and cytoplasmic inclusions, the latter being characterized by their phloxinophilia which contrasts with the hematoxylinophilia of nuclear inclusions. Differential interference microscopy improved visualization and photography of cytoplasmic inclusions. Hydrocephalus developed in a few of the animals and was studied in late phases of the disease.

Animals↗

PubMed1989

Cytophotometric and interference microscopic investigations in carcinomas of the oral cavity.

The DNA content and the nuclear dry mass of 18 keratinized squamous cell carcinomas and their metastases, of one adamantinoma recurrence and two adenoid cystic carcinomas of the oral cavity were determined in comparison to the normal buccal mucosa using Feulgen scanning cytophotometry and interference microscopy. The squamous cell carcinomas could be classified into five groups based on their DNA distribution pattern. The nuclear dry mass and its variation were found to be different from the normal mucosal epithelial cells in all cases. No differences could be found between diploid cells and cells of a higher degree of ploidy. Therefore the relation of nuclear dry mass and DNA content appeared to be lower in cells of higher DNA ploidy. This fact is discussed in relation to the underlying molecular biological processes. This leads to the conclusion that the increase of the nuclear dry mass (mainly protein) precedes the increase of the DNA content. The combined measurement of DNA content and nuclear dry mass allows a better characterization of malignancy than each of the nuclear components measured alone. The difference of nuclear dry mass between malignant cells and normal mucosal epithelial cells is more sensitive than the deviation of the DNA content owing to the fact that malignant tumours with normal DNA content exist.

Carcinoma, Squamous Cell↗

PubMed1984

Microfilament distribution and adhesion patterns in cultured cells after glutaraldehyde-formaldehyde fixation.

To study the relationship between microfilament distribution and adhesion patterns in the same cultured cell, we have employed a simple glutaraldehyde-formaldehyde fixation technique followed by permeabilization of the cells in buffered Triton X-100. This method gives an excellent preservation of cellular morphology in general and of adhesion patterns in particular for examination with surface reflection interference microscopy. It also permits the concomitant use of the actin-specific fluorescent probe NBD-phallacidin to visualize the distribution of microfilaments.

Cell Adhesion↗

PubMedDate not supplied

[Changes in the dry weight of retinal pigment epithelium cells in the postnatal ontogeny of rats].

The dry weight of cytoplasm of individual cells of the retinal pigment epithelium was determined by interference microscopy in the rats (both in mononuclear and binuclear cells). During postnatal development the dry weight of cell cytoplasm is subject to fluctuations: it increases from the 1st till the 5th day, decreases between the 5th and 15th days and increases again between the 15th and 18th days. It is suggested that the decrease in dry weight of cytoplasm of the retinal pigment epithelium cells precedes the onset of phagocytizing by these cells of shed discs of the external rod segments.

Animals↗

PubMed1982

[Action of hypothyroidism on the metabolic maturation of the pyramidal neurons of the rat hippocampus].

Interference microscopy was used to measure dry mass of pyramidal neurones of hippocampal CA1 and CA3 areas in control and hypothyroid rats aged 14 and 21 days and 2 months. Hypothyrosis was induced in the newborn by intraperitoneal injection of methylthiouracil to the lactating female during the lactation period (for 1 month). Hypothyrosis caused a considerable retardation of the animals' growth. A significant decrease in he concentration of dry substances was detected only in the cytoplasm of Ca1 area neurones in the group of 2-month-old hypothyroid animals. The measurements have demonstrated that hypothyrosis gives rise to pronounced retardation of the neuronal build-up and accumulation of protein products in the cytoplasma of hippocampal pyramidal cells in all the animal groups examined. The size and dry weight of neuronal nuclei of both the hyppocampal areas substantially diminish in the group of 2-month-old hypothyroid animals.

Aging↗

PubMed1994

An indirect comparison of third-body wear in retrieved hydroxyapatite-coated, porous, and cemented femoral components.

The osteoconductive properties of hydroxyapatite (HA)-coated titanium implants are well documented, but eventual coating degradation may result in HA particles adjacent to the substrate, and if the particles were to migrate into the joint space then accelerated polyethylene wear might be expected. As an indirect indication of third-body wear, the authors used laser interference microscopy to measure and compare surface roughness on modular heads from 15 clinically retrieved HA-coated femoral components, with heads from 15 retrieved uncemented (porous) and 15 cemented implants. The results showed increased median surface roughness over initial manufacturer specifications in all groups, but the cobalt-chrome heads from the HA-coated group showed significantly less surface roughness and less deep scratches than the heads from either the porous or uncemented group. Three-body wear appears to be a common problem, but evidence available suggests that it is no more of a problem with HA-coated devices than porous or cemented.

Cementation↗

PubMed1995

Histologic observations of bone remodeling adjacent to endosteal dental implants.

To examine bone morphology associated with endosteal dental implants at various time intervals, we inserted 20 one-stage and 20 two-stage titanium blade implants and 20 one-stage and 20 two-stage titanium root-form implants into 30 dog mandibles. Sixteen implants in 6 control (c) dogs (in situ five months) did not receive bridgework. Sixty-four implants in 24 dogs supported bridges for six, 12, 18, or 24 months. The entire area of the mandible containing the implants was examined by routine light and Nomarski differential interference microscopy (NM) for bone morphology (including osteon orientation) at the implant surface and at regions away from the implant. Control root-form implants were apposed by woven bone, with homogenous compact bone in the cortical plate distant to the implant. After 6 mo of load, immature bone was predominant apposing the implant, but initial osteonal maturation was apparent. NM clearly demonstrated the interstitial and concentric lamellae of the bone. Surprisingly, compact bone formed internal to the cortical plate, an area where trabecular bone is expected. At later periods of load, more mature osteons were seen apposing the implants; however remodeling events were still apparent. These remodeling events extend further away from the implant than was expected if the events resulted only from surgical repair. Also, when the implant inclined so that half was totally in the cortical plate and half in the marrow (in trabecular patterns), osteonal bone appeared to remodel in both areas. Control blade implants and blades loaded for six months were apposed by immature osteons when the implant was placed into the cortical plate. A trabecular meshwork was inferior to the osteonal bone. At 12 mo of load, the bone internal to the cortical plate appeared similar to the lamina dura supporting teeth; however, no PDL existed; the lamina-dura-like pattern directly apposed the implant. Even after 24 mo of load, extensive bone remodeling was apparent adjacent to the implant, markedly different from the bone making up the existing cortical plate. From these data, remodeling activities to blade implants may involve the development of a lamina-dura-like bone morphology after longer periods of load. Osteonal bone was apparent, but only at regions where the implant was inserted into the cortical plate. Further, bone remodeling was apparent even after long periods of load.

Alveolar Process↗

PubMedDate not supplied

Quantification of ciliary beat frequency in sinonasal epithelial cells using differential interference contrast microscopy and high-speed digital video imaging.

BACKGROUND: Mucociliary clearance is a critical upper airway host defense mechanism. Ciliated epithelium in the mammalian airway continually beat at a baseline frequency. Importantly, during times of stress such as exercise or infection, the cilia beat faster to increase clearance. Nasal epithelial ciliary beat frequency (CBF) has been analyzed previously in ex vivo specimens using a variety of methods including photodiode detectors and conventional video recording. Recent studies performed using lower airway ciliated mucosa have shown poor correlation between CBF quantified by photodiode/conventional video and those using high-speed digital video capture at temperatures close to physiological temperatures. Thus, to more rigorously interrogate sinonasal CBF at physiological conditions, we have incorporated a high-speed digital video camera to our CBF analysis system. This is the first report of sinonasal epithelial CBF analysis performed using high-speed video digital analysis. METHODS: Ex vivo samples of sinonasal epithelium were placed in lactated Ringer's in a temperature-controlled microscope stage chamber. An edge of tissue containing beating cilia was observed at a magnification of 630x using differential interference contrast microscopy. The images were captured using a high-speed digital camera with a sampling rate of 250 frames per second. CBF was determined using computerized data analysis. RESULTS: The mean nasal CBF was calculated from a minimum of five regions for each sample. Temperature curves were generated from tissue obtained from chronically infected subjects. CONCLUSION: Analysis of high-speed digital video capture of sinonasal CBF observed under differential interference contrast microscopy is a powerful method to investigate environmental as well as host influences on mucociliary clearance within the upper airways.

Cilia↗

PubMed2006

The distance that kinesin-1 holds its cargo from the microtubule surface measured by fluorescence interference contrast microscopy.

Kinesin-1 is a motor protein that carries cellular cargo such as membrane-bounded organelles along microtubules (MTs). The homodimeric motor molecule contains two N-terminal motor domains (the motor "heads"), a long coiled-coil domain (the "rod" or "stalk"), and two small globular "tail" domains. Much has been learned about how kinesin's heads step along a MT and how the tail is involved in cargo binding and autoinhibition. However, little is known about the role of the rod. Here, we investigate the extension of the rod during active transport by measuring the height at which MTs glide over a kinesin-coated surface in the presence of ATP. To perform height measurements with nanometer precision, we used fluorescence interference contrast microscopy, which is based on the self-interference of fluorescent light from objects near a reflecting surface. Using an in situ calibrating method, we determined that kinesin-1 molecules elevate gliding MTs 17 +/- 2 nm (mean +/- SEM) above the surface. When varying the composition of the surrounding nucleotides or removing the negatively charged -COOH termini of the MTs by subtilisin digestion, we found no significant changes in the measured distance. Even though this distance is significantly shorter than the contour length of the motor molecule ( approximately 60 nm), it may be sufficient to prevent proteins bound to the MTs or prevent the organelles from interfering with transport.

Animals↗

PubMed2005

Measuring lipid asymmetry in planar supported bilayers by fluorescence interference contrast microscopy.

There is substantial scientific and practical interest in engineering supported lipid bilayers with asymmetric lipid distributions as models for biological cell membranes. In principle, it should be possible to make asymmetric supported lipid bilayers by either the Langmuir-Blodgett/Schafer (LB/LS) or Langmuir-Blodgett/vesicle fusion (LB/VF) techniques (Kalb et al. Biochim. Biophys. Acta 1992, 1103, 307-316). However, the retention of asymmetry in biologically relevant lipid bilayers has never been experimentally examined in any of these systems. In the present work, we developed a technique that is based on fluorescence interference contrast (FLIC) microscopy to measure lipid asymmetry in supported bilayers. We compared the final degree of lipid asymmetry in LB/LS and LB/VF bilayers with and without cholesterol in liquid-ordered (l(o)) and liquid-disordered (l(d)) phases. Of five different fluorescent lipid probes that were examined, 1,2-dipalmitoyl-phosphatidylethanolamine-N-[lissamine rhodamine B] was the best for studying supported bilayers of complex composition and phase by FLIC microscopy. An asymmetrically labeled bilayer made by the LB/LS method was found to be at best 70-80% asymmetric once completed. In LB/LS bilayers of either l(o) or l(d) phase, cholesterol increased the degree of lipid mixing between the opposing monolayers. The use of a tethered polymer support for the initial monolayer did not improve lipid asymmetry in the resulting bilayer. However, asymmetric LB/VF bilayers retained nearly 100% asymmetric label, with or without the use of a tethered polymer support. Finally, lipid mixing across the center of LB/LS bilayers was found to have drastic effects on the appearance of l(d)-l(o) phase coexistence as shown by epifluorescence microscopy.

Lipid Bilayers↗

PubMed1988

Growth cone configuration and advance: a time-lapse study using video-enhanced differential interference contrast microscopy.

We have analyzed the dynamics of growth cone configuration using video-enhanced contrast differential interference contrast microscopy. Regenerating neurites from NGF-treated PC12 cells and sympathetic neurons were observed in real time during their elongation and reviewed by time-lapse video recordings. This technique provided a high-resolution view of motile growth cone elements including filopodia, microspikes, lamellipodia and ruffles. On the basis of our observations, a multistage model for growth cone advance is proposed. Elongation commences with lamellipodial spreading. If the newly extended lamellipodium does not retract or lift off the substrate in the form of a ruffle, a second phase--consolidation--occurs, in which the lamellipodium thickens as it fills with cytoplasm and organelles. The consolidated area then undergoes further transformation into an area of neuritic shaft as new lamellipodia form at the leading and peripheral zones of the distal process. We never observed filopodia or microspikes contracting to propel the growth cone forward. We also noted that elongating tips generally had large varicosities within 20 micron of their leading edges. These may play a role in neurite outgrowth and in the formation of smaller, synaptic vesicle-containing varicosities. The dynamic behavior of the growth cone was under the control of NGF. Withdrawal of NGF resulted in the disappearance of motile structures and cessation of growth, while readdition of NGF triggered the rapid reappearance of these structures and the resumption of growth. The high-resolution video microscopy of living growth cones provides necessary baseline information, as well as a bioassay paradigm, for future studies on the molecular mechanisms of nerve growth.

Adrenal Gland Neoplasms↗