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PubMed1986

Birefringent objects visualized by circular polarization microscopy.

In the standard polarizing microscope, birefringent material appears bright only if its optic axis is oblique to the axes of the polarizer and analyzer filters; consequently, an object may be visualized as several disconnected bright regions. This confusing appearance is avoided if the crossed plane polarizers of the conventional microscope are replaced by circular polarizers of opposite handedness. All orientations of the optic axis in the focal plane then become equivalent; objects generally appear uniformly bright. Ordinary microscopes are easily modified to use this technic with readily available components.

Birefringence↗

PubMed1997

[Imaging of laser thermokeratoplasty lesions by optical low coherence tomography and polarization microscopy after Sirius Red staining].

BACKGROUND: Information on the extent and degree of the thermal effect produced is of great importance for control of the laser dosage in laser thermokeratoplasty (LTK) and for postoperative follow-up. We investigated on acute LTK effects which information images obtained by optical low coherence tomography (OCT) offer compared to those obtained by polarization microscopy. METHODS: Porcine eyes were irradiated through a 400 microns quartz fiber using light from a laser diode emitting up to 300 mW at a wavelength of 1.86 microns. Thermal lesions of varying strength were scanned using an experimental OCT device with about 25 microns lateral and 20 microns axial resolution. Histologic evaluation of the scanned areas was done by polarization microscopy after Sirlus-Red staining, and similar lesions were also analyzed by TEM. RESULTS: Both methods differentiated three damage zones a transition zone, a zone of moderate coagulation, and a central zone of strong coagulation. In the transition zone, increased birefringence was seen in polarization microscopy, which correlated with increased light scattering seen in the OCT images. In the moderately coagulated zone, a decrease in birefringence was associated with an even stronger increase of the OCT signal. In the central zone, a loss of the fibrillar tissue structure was observed, which led to a complete loss of birefringence and a strong reduction of the OCT signal. CONCLUSIONS: Although OCT does not provide the detailed information on thermal changes of tissue seen by the histologic method, it offers information on the extent and degree of tissue changes without preparation artifacts and provides a non-invasive method of immediate and follow-up control of LTK lesions. A quantitative analysis of changes in corneal thickness and curvature is much simpler than by a slit lamp. Time-resolved measurements of corneal light scattering may be used for on-line control of the laser-light dosage during LTK.

Animals↗

PubMed1986

Polarization microscopy of hair in acrodermatitis enteropathica.

We studied the hair of a 10-month-old girl who was suffering from acrodermatitis enteropathica, using light and polarizing microscopy before and after institution of zinc therapy. The hair was very thin and brittle. On light microscopy the shafts showed uneven diameter and some displayed atypical trichorrhexis nodosa with stretched fractures. Ten percent of the hair fibers exhibited nodal swellings of the pseudomonilethrix type. Polarization microscopy disclosed in 70% of all hair shafts an irregular pattern of alternating dark and bright bands. This anomaly was still present in 10% of the hair shafts after one and one-half years of zinc therapy, but could no longer be detected after two years of zinc supplementation. Repeated determinations of hair probes before and after treatment gave a low cystine content, however, being still in the normal range. We assume that the observed changes and the low hair cystine content can be attributed to the underlying zinc deficiency.

Acrodermatitis↗

PubMed1995

[Use of polarization microscopy in the determination of activity and differential diagnosis of pulmonary tuberculosis].

45 patients with pulmonary tuberculosis, 15 patients with acute pneumonia and 15 healthy controls were examined using polarization microscopy of blood serum and blood serum + tuberculin. The serum from healthy subjects contains optically active structures, while that from patients has also pathological structures. Frequency of detection, quantitative and qualitative composition of pathological structures in tuberculosis are related to the disease phase and decline with the activity inhibition. Examination of native serum is not able to distinguish specific from nonspecific processes in the lungs. The addition of tuberculin to native serum helped detect subclinical tuberculosis. Polarization microscopy of native serum is recommended for control of pulmonary tuberculosis and treatment efficacy, modification with tuberculin may be used as an additional test for determination of the disease activity and for differential diagnosis with acute pneumonia.

Acute Disease↗

PubMed1991

Lipid order in hepatocyte plasma membrane blebs during ATP depletion measured by digitized video fluorescence polarization microscopy.

Low-light digitized video fluorescence polarization microscopy was used to measure lipid order parameters in plasma membrane blebs of single, cultured rat hepatocytes during ATP depletion with the metabolic inhibitors cyanide and iodoacetic acid. Hepatocytes were labeled on the microscope stage with the plasma membrane probe trimethylammoniumdiphenylhexatriene at successive stages of cell injury. A pair of fluorescence polarization ratio images was obtained from a series of four fluorescence images recorded with a polarizer in the emission path oriented first parallel and then perpendicular to each of two orthogonal excitation light polarization directions. From the polarization ratio images, the lipid order parameter S was determined in individual plasma membrane blebs. Results indicate that the plasma membrane becomes uniformly rigid within a few minutes of the addition of metabolic inhibitors when small surface blebs have formed and ATP levels have fallen by greater than 95%. The measured order parameter of S approximately 0.95 in plasma membrane blebs, compared with S approximately 0.75 in normoxic cell plasma membranes, remained unchanged throughout the course of bleb development and ultimate cell death. These findings demonstrate that significant alteration in hepatocyte plasma membrane structure occurs early in hypoxic cell injury.

Adenosine Triphosphate↗

PubMed1978

Differential staining of collagens type I, II and III by Sirius Red and polarization microscopy.

Organs of fish, amphibian, reptile, bird and mammals when stained by Sirius Red and studied with polarization microscopy present different colors in regions where collagens I, II and III have been described. Collagen type I presented a yellow, orange or red color while collagen type III appeared green. Collagen type II, present in cartilage and chondrosarcoma showed a variable color according to the tissue and the species. Its color and morphology however always permitted its clear distinction from collagens type I and type III.

Animals↗

PubMed2006

Stromal differences in salivary gland tumors of a common histopathogenesis but with different biological behavior: a study with picrosirius red and polarizing microscopy.

Salivary gland neoplasms - pleomorphic adenoma, polymorphous low-grade adenocarcinoma, and adenoid cystic carcinoma - share a common histogenetic trait, but differ markedly in their biological properties. The objective of the study was to assess the polarization colors of picrosirius red-stained stromal collagen fibers in these salivary gland neoplasms to evaluate their possible role in the histopathogenesis of the tumors and to evaluate the potential usefulness of this approach as a diagnostic tool. Ten cases of each tumor type and 10 cases of mucous extravasation phenomenon (control) were examined using picrosirius red staining and polarizing microscopy. In each case, at least 50 thin ( approximately 0.8 microm) and 50 thick (1.6-2.4 microm) collagen fibers were counted and classified as green-yellow or yellow-orange, the mean percentage was calculated and statistical differences analyzed by one-way ANOVA. Results showed a similar thin fiber distribution in all tumor types and controls (82-88% green-yellow, 12-18% yellow-orange, p>0.05). Thick fibers showed a different distribution in polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma (approximately 50% green-yellow) compared to pleomorphic adenoma and mucous extravasation phenomenon (approximately 13% green-yellow) (p=0.001). Thick fiber distribution was similar in polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma (p>0.05). We conclude that with picrosirius red staining and polarizing microscopy, stromal collagen fibers differ significantly in pleomorphic adenoma from those in polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma, but not from mucous extravasation phenomenon. Similarity between polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma may indicate that these tumor types represent a single entity with a broad spectrum of biological behavior.

Adenocarcinoma↗

PubMedDate not supplied

Differential polarization microscopy of changes in structure in spermatocyte nuclei.

Phase-dependent forms of microscopy (such as phase contrast, interference, or polarization microscopy) have been used for many years; the amount of phase retardation produces images based mainly on index of refraction. We have developed a microscope that forms images that depend on small differences in extinction for different forms of incident polarized light. By modulating the polarization of light incident on the sample and digitally recording the difference in intensities of transmitted light, we obtain images which specifically reveal either ordered linear structures or chiral (right- or left-handed) structures. Linearly polarized light, incident alternately with two perpendicular directions of polarization, forms images of structures which have linear order or linear orientation. Right-handed and left-handed circularly polarized light incident alternately on a sample forms images of chiral structures. Structures with neither linear order nor chirality are essentially invisible. Thus, images based on linear dichroism, circular dichroism, and linear and circular differential scattering can be used to detect specific types of structures which may be difficult to observe by conventional methods. We have used such 'linear and circular differential imaging' to study the structure of the nucleolus (the site of RNA synthesis) in live primary spermatocytes of Drosophila when they are transcriptionally active or inactive. Some inactive nucleoli are bipartite, with two distinct structures visible by differential scattering of both linearly and circularly polarized light. The active nucleolus is a single domain; it is clearly distinguished from part of the Y chromosome, and it shows different internal structure with linearly and circularly polarized light. Thus, polarization-dependent images reveal structures which can be associated with the transcriptional activity of cells.

Animals↗

PubMed1993

[Methodologic comparison of the analysis of urinary calculi. Roentgen diffractometry, polarization microscopy and microscopic-microchemical component analysis].

Not only instrumental, apparative or operative stone extraction is necessary for patients with urolithiasis (particularly those with recurrent urolithiasis); preventive treatment is also called for, and for this exact analysis of the composition of the stones is essential. The procedures currently accepted as standard for stone analysis are: X-ray diffraction, infrared spectroscopy, polarisation microscopy and the complicated chemico-quantitative analyses performed in some institutes. Recently a new, so-called microscopic-microchemical, analysis of stone components has been presented (the Harzalith). To test the value of this procedure as compared to e.g. X-ray diffraction or polarization microscopy, a comparative study was carried out in our department. Thirty different urolith compositions (calculi with one and with more components) were analysed qualitatively and quantitatively by three methods. No qualitative difference was found between X-ray diffraction and polarization microscopy; however, there was a difference from the Harzalith method, and with increasing number of components there was hardly any correspondence with the other methods. Only 10% of the calculi with three or four components could be analysed correctly. Often, too many components were determined by the new method. The test material was analysed by three laboratory assistants working independently of each other.

Cholelithiasis↗

PubMed1988

An investigation of optimal gold particle size for immunohistological immunogold and immunogold-silver staining to be viewed by polarized incident light (EPI polarization) microscopy.

We investigated the optimal gold particle size for use with polarized incident light (epi polarization) microscopy with immunogold immunohistological preparation in both immunogold indirect (IGS) and silver-enhanced immunogold-silver staining (IGSS) techniques. A range of gold particle sizes from 5 nm-40 nm was used along with tissue of known immunoreactivity with a well-characterized primary monoclonal antibody. Checkerboard titrations were carried out for each technique and for each particle size. The preparations were viewed using a standard polarized incident light microscope and assessed in a semi-quantitative manner. Adequate visualization of gold particles was achieved using the indirect staining method only with a particle size of 40 nm. With silver enhancement (IGSS), particles of all sizes were clearly seen. However, 5-nm particles were considered optimal for this method because of reduced background staining, high titration of antisera possible, and crisp localization of the visual signal.

Gold↗

PubMed1983

Polarizing microscopy of birefringent lipids in rabbit fetal lungs.

The development of birefringent lipids in pre- and postnatal rabbit lungs was studied by polarizing microscopy (PM) and correlated with transmission electron microscopy (TEM). Birefringent lipids first appeared as small scattered particles in the developing alveolar walls at 27 days of gestation. These particles became aggregated, gradually increased in amount in older fetuses, and reached a prenatal maximum at 30 days. Numerous particles were located in the alveolar lumen, beginning in the 30-day fetuses. Further increase in the amount of birefringent lipids occurred in the 60-day-old rabbits. TEM demonstrated cytoplasmic lipid inclusion bodies in the type II pneumocytes at 25 days of gestation. Some of these inclusions were lamellated, but regular lamellated bodies were often seen in older fetuses. It appears that the development of birefringent lipids is closely correlated with the development of lamellated bodies seen with TEM, and PM is a simple, useful method in following the development and maturation of surfactant lipids.

Animals↗

PubMed2005

George Romhányi (1905-1991): pioneer in amyloid research and polarization microscopy, on the 100th anniversary of his birth.

George Romhányi was an outstanding pathologist, university teacher and a renowned scientist of the 20th century. After studying medicine and pathology, his scientific interest focused on haemochromogenic reactions and submicroscopic structure research. He was among the first to describe the fibrillar-micellar structure of amyloid, as well as the helical-fibrillar structure of elastic fibres. Between 1951 and 1976 Romhányi held the chair of pathology at the University of Pécs. During this time he published numerous topo-optical reactions leading to a renaissance of polarization microscopy. Romhányi's topo-optical reactions possess a high molecular specificity and enabled submicroscopic structural analysis. He and his disciples analysed the biomembrane, collagen fibres, the extracellular matrix of connective tissues, cell walls of bacteria and fungi, the ergastoplasmatic membrane, RNA and DNA. Romhányi's investigation of a range of amyloid depositions was a milestone and led to intensive immuno-biologic research in this area. He firmly held the opinion that polarization microscopy is, along with the electron and fluorescent microscopy, indispensable for solving fundamental questions of molecular biology.

Amyloidosis↗

PubMed2004

Fatal disseminated cryptococcosis in a HIV negative elderly Indian woman--an early diagnosis by polarizing microscopy.

An elderly HIV negative woman with disseminated cryptococcosis is reported. The clinical presentation was unusual. Rapid diagnosis is possible if Maltese crosses are demonstrated on polarizing microscopy of tissue sections or smears. Cutaneous involvement in cryptococcosis is uncommon, however when present, can be a valuable and relatively easily available source of material from which Cryptococci can be demonstrated.

Aged↗

PubMed1999

Polarizing microscopy of eyespot of Chlamydomonas: in situ observation of its location, orientation, and multiplication.

The eyespot in the cell of Chlamydomonas reinhardtii has been found to appear as a bright spot under the cross polar setting of a polarizing microscope. This was confirmed by isolating the eyespot from a homogenate of wall-deficient mutant cw-15, and by observing it under a polarizing microscope. Thus, the eyespot was proved to be a strongly birefringent body. Next, gametes (mt+ and mt-) of 137c strain were prepared by cultivating it in a low-nitrogen (NH4Cl) medium. Here, every cell shows only one (and never more than one) birefringent spot. The birefringent eyespot was located always near the surface on the "equator," that is, at the farthest point from the "meridionial" cell-axis that is defined as the bisector of the two flagella projected out from the cell surface. It was shown, in addition, that the optic axis of this birefringent eyespot is oriented in the cell always along the parallel direction of the cell axis defined above. Thus, the polarizing microscopy has been shown to provide a powerful method for in vivo, in situ pursuit of the eyespot of Chlamydomonas.

Animals↗

PubMedDate not supplied

Submicroscopic structure of glycosaminoglycans in osteocyte capsule of human embryonic bone as revealed by polarization microscopy.

Using qualitative and quantitative polarization microscopical techniques, an axiparallel orientation of chondroitin sulfate molecules and collagen fibrils could be detected in the osteocyte capsule of human embryonic and fetal bones. It is suggested that this spatially oriented microstructure plays a role in ana- and catabolic transport processes of the bone tissue.

Bone and Bones↗

PubMed1965

APPLICATION OF POLARIZING MICROSCOPY TO MEDICAL MYCOLOGY.

The hyphae of 15 species of fungi were cultivated by conventional slide-culture technique and then examined by polarizing microscopy. Extinction angles exhibited by the anisotropic chitin in the cell walls of hyphae were, as a rule, measurable within a minimal growth range of 2 to 3 days after inoculation to slide culture. Of the 15 species examined, 8 saprophytic fungi were found to possess a range of common extinction angles (10 degrees +/- 2 degrees ). The remaining seven organisms implicated as pathogens were found to possess a range of common extinction angles (20 degrees +/- 2 degrees ). There appears to be a correlation existing between the pathogenic nature of the examined fungi and their extinction angles, as demonstrated by the polarizing microscope.

Aspergillus↗

PubMed1982

10,000 analyses of urinary calculi using X-ray diffraction and polarizing microscopy.

To make qualitative as well as semiquantitative analyses of 10,000 urinary calculi of large city population, a combined crystal-optical X-ray diffractometric method proved to be very useful. This combination goes to complement the advantages of polarization microscopy (with its minimal substance requirements, its proof limits of less than 1%, and its insight into stone texture) with those of X-ray diffraction (with its fast semiquantitative analysis and simple differentiation of all the stone components). About 30% of the calculi were found to have a monomineral composition. The most frequent types of calculi in our examination were: 33.2% whewellite/weddellite, 24.9% whewellite, 13.5% whewellite/weddellite/apatite, 7.0% struvite/apatite, and 3.9% uric acid/uric acid dihydrate.

Humans↗

PubMed2002

Three-dimensional director structures of defects in Grandjean-Cano wedges of cholesteric liquid crystals studied by fluorescence confocal polarizing microscopy.

We use a nondestructive technique of fluorescence confocal polarizing microscopy to visualize three-dimensional director patterns of defects in Grandjean-Cano wedges filled with a cholesteric liquid crystal of pitch p=5 microm. Strong surface anchoring of the director causes a stable lattice of dislocations in the bulk. Optical slicing in the vertical cross sections of the wedges allows us to establish the detailed structure of dislocations and their kinks. Dislocations of Burgers vector b=p/2 are located in the thin part of the sample, very close to the bisector plane. Their cores are split into a pair of tau(-1/2) and lambda(+1/2) disclinations. Pairs of lambda(-1/2) and tau(+1/2) disclinations are observed when the b=p/2 dislocation forms a kink. The kinks along the b=p/2 dislocations change the level of dislocations by +/-p/4 and +/-p/2; these kinks are confined to the glide plane and are very long, (5-10) p. Above some critical thickness h(c) of the wedge sample, the dislocations are of Burgers vector b=p. They are often found away from the bisector plane. The core of b=p dislocations is split into a pair of nonsingular lambda(-1/2) and lambda(+1/2) disclinations. The kinks along the b=p dislocation are of a typical size p and form cusps in the direction perpendicular to the glide plane. At the cusp, lambda(-1/2) and lambda(+1/2) disclinations interchange ends. Other defect structures inlude "Lehmann clusters," i.e., dislocations of zero Burgers vector formed by two lambda(-1/2) and two lambda(+1/2) disclinations and dislocations of nonzero Burgers vector with a core split into more than two disclinations. We employ the coarse-grained Lubensky-de Gennes model of the cholesteric phase to describe some of the observed features. We calculate the elastic energy of a dislocation away from the core, estimate the energy of the core split into disclinations of different types, study the effect of finite sample thickness on the dislocations energy, and calculate the Peach-Koehler elastic forces that occur when a dislocation is shifted from its equilibrium position. Balance of the dilation/compression energy in the wedge and the energy of dislocations defines the value of h(c) and allows to estimate the core energy of the dislocations. Finally, we consider the Peierls-Nabarro mechanisms hindering glide of dislocations across the cholesteric layers. Because of the split disclination character of the core, glide is difficult as compared to climb, especially for b=p dislocations.

Journal Article↗