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PubMed1988

[An architectural study of mixed uric acid and calcium oxalate stones by polarized light microscopy of thin section].

The architecture of mixed uric acid and calcium oxalate stones was studied by polarized light microscopy. Some uric acid stones contained calcium oxalate stones (whewellite or weddellite) as a nucleus. Other uric acid stones contained calcium oxalate crystals in the nucleus or inner portion. A uric acid stone covered with layers of calcium oxalate was also found. In the mixed stones, nuclei of randomly mixed fine grained whewellite and uric acid were seen and both crystals appeared in alternating sequence in the outer layers. Weddellite crystals dissolved layers of uric acid and invaded into them in the nuclear or peripheral zones. Whewellite may precipitate in the same or a similar condition as uric acid precipitates, whereas weddellite may precipitate in a different condition. We discussed the pathogenesis of mixed uric acid and calcium oxalate stones, heterogeneous nucleation and epitaxial growth based on a morphologic study of the mixed stones.

Calcium Oxalate↗

PubMed1995

Validation of wall thickness estimates obtained with polarized light microscopy using multiple fluorochrome labels: correlation with erosion depth estimates obtained by lamellar counting.

Numerous methods are currently being employed to estimate completed wall thickness and final erosion depth. Conflicting estimates of calculated bone balance have been obtained from the estimates of wall thickness and erosion depth using these various methods. To assess the utility of two specific methods to estimate wall thickness (polarized microscopy) and erosion depth (lamellar counts), we conducted a study in normal young adult beagle dogs, a model where bone balance should approximate 0. Dogs were administered multiple fluorochrome labels in vivo to label activity forming bone pockets. These labels were used to confirm the position of the cement line of the bone structural unit (BSU) in fluorescent light. Parallel measurements of wall thickness were then collected in polarized light. These estimates were compared to estimates of erosion depth obtained by lamellar counting and bone balance was calculated. Estimates of wall thickness correlated well with estimates of erosion depth with bone balance not differing significantly from 0. These data suggest that the combination of these two methods is a reasonable approach to obtaining estimates of bone balance at the level of the remodeling unit.

Animals↗

PubMed2006

Polarized light microscopy of hair shafts aids in the differential diagnosis of Chédiak-Higashi and Griscelli-Prunieras syndromes.

PURPOSE: To study and compare the appearance of hairs from patients with Chédiak-Higashi and Griscelli-Prunieras syndromes under light and polarized light microscopy. METHOD: Hairs from 2 Chédiak-Higashi and 2 Griscelli-Prunieras patients were obtained and examined under normal and polarized light microscopy. RESULTS: Under light microscopy, hairs from Chédiak-Higashi patients presented evenly distributed, regular melanin granules, larger than those seen in normal hairs. Under polarized light microscopy, shafts exhibited a bright and polychromatic refringence appearance. In contrast, hair from Griscelli-Prunieras patients, under light microscopy, exhibited bigger and irregular melanin granules, distributed mainly near the medulla. Under polarized light microscopy, shafts appeared monotonously white. CONCLUSION: Light microscopic examination of hair shafts of patients with Chédiak-Higashi or Griscelli-Prunieras syndrome reveals subtle differences that are useful in identifying both disorders, but not in distinguishing between them. We provide evidence that polarized light microscopy of hair shafts, an approach that has not been previously described, aids in differentiating between these syndromes. We propose hair study by polarized light microscopy as a helpful complementary diagnostic method for differential diagnosis between CHS and GPS, especially when the more sophisticated molecular studies are not available.

Adult↗

PubMed1983

A method for the detection of amyloid in human tissue embedded in epon using a combination of polarizing light microscopy and electron microscopy.

This paper describes a method for demonstrating amyloid in human tissue embedded in epon using a combination of congo red staining and polarizing microscopy. The method involves the removal of the embedding medium from semi-thin sections prior to staining with congo red and examination in the polarizing microscope. Typical apple green birefringence was detected in areas of amyloid deposition; these areas were mapped for selective trimming and ultra-thin sections taken serially were examined in the electron microscope. The method was found to be reliable, easy to use and particularly of value as a sampling procedure prior to investigation in the electron microscope.

Amyloid↗

PubMed1986

Polarized light microscopy in the study of the molecular structure of collagen and reticulin.

Although collagen structure has been studied by polarized light microscopy since the early 19th century and continued since, modern studies and reviews failed to correlate the conclusions based on data obtained by the techniques with those of polarized light microscopy. Collagen I is intensely positively birefringent in respect to length of the fibres; the positive intrinsic birefringence indicates a quasi-crystalline alignment parallel to the fibre and molecule axis of the amino acid residues of the polypeptide chains. This would not have been compatible with a helical structure but has been achieved by similar tilt angles and opposite directions of the coiling and supercoiling. Birefringence characteristics of collagen are also affected by chemical treatments, extractions and staining procedures. Attachment of chemical groups to the anionic charges present on the surface of collagen molecules results in increased positive birefringence in the case of bipolar molecules attached to two or more anionic residues. Unipolar attachment to the same groups, or to the cationic groups of the associated proteoglycans, as well as sulfation or acetylation of hydroxyls of the protein and/or the carbohydrate, reduced or reversed the sign of birefringence. Increased birefringence caused by stretching cannot be due to intramolecular events and is caused by intermolecular changes. The same applies to changes in collagen during aging. Reticulin is a group of different substances which mostly contain collagen III. The pliability and deformability of this collagen is related to its weakly negative birefringence due to large side chains and presence of different and greater amounts of interstitial proteoglycans and other molecules. The so-called reticulin of healing wounds differs in its constitution from other reticulins but is also rich in intermolecular carbohydrate components.

Birefringence↗

PubMed1980

[Morphological types of the changes in the myofibrils of cardiac muscle cells].

Light microscopy and electron microscopy examinations showed the changes in myofibrils to be a criterion of early stages of cardiomyocyte involvement. Proceeding from this, the main types of acute cardiomyocyte damage are distinguished: contractures (segmentary and subsegmentary), primary clump degeneration, intracellular myocytolysis and cytolysis. The best way to detect the state of myofibrils by light microscopy is to use polarization microscopy which diagnoses in sections acute metabolic damages and early stages of myocardial infarction, repeated and relapsing infarctions, fibrillation of ventricles. The utilization of polarization microscopy in pathological practice permits one to diagnose definitely the early stages of acute damages of the heart in cases of sudden and unexpected death.

Animals↗

PubMed2002

Collagenase-induced changes in articular cartilage as detected by electron-microscopic stereology, quantitative polarized light microscopy and biochemical assays.

The purpose of this study was to compare the ability of electron-microscopic (EM) stereology with quantitative polarized light microscopy (PLM) and biochemical collagen (hydroxyproline) and crosslink (pyridinoline) analyses to detect changes in the superficial collagen network of bovine articular cartilage after digestion in vitro with purified bacterial (Clostridium histolyticum) collagenase (30 U/ml) for 24 and 48 h. Collagen volume (V(V)) and surface (S(V)) densities of the uppermost third of the superficial zone were estimated indirectly from zonal isotropic uniform random sections using collagen length density (L(V)) and average collagen fibril diameter, or its average second power. Collagenase digestion caused a significant decrease in fibril diameter (64 to 62%), V(V) (89 to 95%) and S(V) (64 to 86%) after incubation for 24 and 48 h. Collagen L(V) remained unchanged after 24 h incubation but decreased 63% after 48 h. Collagen concentration per dry weight, assayed biochemically from the whole superficial zone, decreased also significantly (29 to 60%) after 24 and 48 h digestions, respectively. The pyridinoline concentration per dry weight of the superficial zone decreased (31 to 57%) whereas the pyridinoline concentration per collagen remained unchanged. PLM revealed that the birefringence of the uppermost third of the superficial zone was decreased by 36% after digestion for 24 h though the total birefringence of the whole zone was not reduced. However, after 48 h, the birefringence of the whole superficial zone was significantly reduced (76%). All of the techniques compared in this study could detect collagen network degradation in bovine articular cartilage but the EM stereological technique was more sensitive at detecting the changes than PLM or biochemical assays.

Animals↗

PubMed1989

Analysis of healing after myocardial infarction using polarized light microscopy.

To better understand the healing process after permanent coronary artery occlusion in a canine model, the authors used polarized light microscopy. At 6 weeks after occlusion the scar collagen was mainly type I. Some regions of the scar contained a fiber lattice which appeared to be type III collagen. Collagen orientation was measured using a universal stage; subepicardial collagen was obliquely aligned (-14.0 +/- 3.5 degrees), midmyocardial collagen circumferentially aligned (1.4 +/- 0.4 degrees) and subendocardial collagen obliquely aligned (12.7 +/- 2.1 degrees). The molecular organization of scar collagen increased from 1 to 6 weeks after occlusion. Muscle cell disarray, similar to that in hypertrophic cardiomyopathy, was seen in the viable muscle adjacent to the scar. Such abnormal organization extended as far as 1 cm from the edge of the scar. The ability of polarized light microscopy to assess these different parameters from histologic sections demonstrates that it is a useful adjunct to other methods commonly used to study myocardial healing.

Animals↗

PubMed1993

The amelocemental junction in young premolar teeth. A replica study by scanning electron microscopy.

To investigate the validity of traditional data on the frequency of various relationships of root cementum to coronal enamel at the amelocemental junction, the relationship in 50 young premolar teeth extracted on orthodontic indications was documented, using replica techniques for scanning electron microscopy (SEM), combined with polarization microscopy of thin ground sections (< 40 microns). Of 200 surfaces, 30 were excluded because of damage during specimen preparation. Replicas of the other 170 surfaces were photographed at 20x and 80x in SEM and classified as having an edge-to-edge relationship of enamel to cementum in 76% and an overlap of cementum onto the cervical enamel in 14%. What appeared to be a gap between enamel and cementum at low magnification (10%) was seen at high magnification to be a ditch or trough in the cementum: no gaps with exposed dentin were observed in SEM. Polarization microscopy of ground sections of the original specimens confirmed the SEM classification. In this material, the edge-to-edge relationship of enamel to cementum predominated: overlapping of cementum onto the enamel was less prevalent than previously reported. The methods applied in this study circumvented some major sources of artefact formation due to shrinkage during specimen preparation, which may previously have caused misinterpretation of 'gap' relationships.

Bicuspid↗

PubMed1996

Orientation-dependent visibility of long thin objects in polarization-based microscopy.

Under conditions of directional illumination, the visibility of long, thin objects depends very strongly on the direction and polarization of the incident light. Solutions to Maxwell's equations for the case of an infinite cylinder in an electromagnetic field are well known, and have been used by others in the past for theoretical analysis of light scattering by long, thin objects. The existence of those solutions allows us to calculate the expected angular distribution and polarization of the light scattered from long, thin objects illuminated by a plane wave at any angle. In this paper we show for the first time how one can incorporate these solutions of Maxwell's equations into a quantitative description of the expected appearance of filamentous biological structures in polarization-based microscopy. Our calculations for unidirectional polarized illumination show that thin, dielectric linear objects such as microtubules (or shallow interfaces) observed with finite aperture optics 1) are totally invisible when the angle (phi) between the object's long axis and incident illumination is outside the range magnitude of 90 - phi < or = sin-1 [1.33/N.A.obj]degrees; and 2) are seen with maximum intensity when phi = 90 degrees for incident illumination and scattered light polarized, either both parallel or both perpendicular to the long axis of the object; whereas 3) two maxima appear at phi approximately equal to 90 +/- 25 degrees for polarization of the incident illumination parallel to, but the scattered light perpendicular to the long axis, or vice versa; and 4) in either of these latter conditions, the objects are invisible when the illumination is near normal incidence. These counterintuitive predictions were exactly borne out by our experimental measurements of light-scattering intensity from flagellar axonemes as a function of orientation in a polarizing microscope. These calculations and measurements provide a foundation for furthering our understanding of textural or form birefringence. Calculations based on a solid cylinder model accurately predict the shapes of the measured intensity versus orientation curves. However, the relative intensities of axonemes viewed with different polarizer-analyzer settings differ from those calculated for a homogeneous solid cylinder. Thus we find that these relative intensities can provide a sensitive probe for the structure of biological objects with diameters much smaller than the wavelength of light.

Animals↗

PubMed1981

Video image processing greatly enhances contrast, quality, and speed in polarization-based microscopy.

Video cameras with contrast and black level controls can yield polarized light and differential interference contrast microscope images with unprecedented image quality, resolution, and recording speed. The theoretical basis and practical aspects of video polarization and differential interference contrast microscopy are discussed and several applications in cell biology are illustrated. These include: birefringence of cortical structures and beating cilia in Stentor, birefringence of rotating flagella on a single bacterium, growth and morphogenesis of echinoderm skeletal spicules in culture, ciliary and electrical activity in a balancing organ of a nudibranch snail, and acrosomal reaction in activated sperm.

Acrosome↗

PubMed1988

The molecular organization of collagen in saccular aneurysms assessed by polarized light microscopy.

The known relationship between the retardation of polarized light and the molecular organization of collagen enabled us to study collagen in cerebral saccular aneurysms, structures in which the collagen is probably abnormal. Six aneurysms and their adjacent arteries, obtained at autopsy, were sectioned at a thickness of 7 microns. Measurements of retardation in hematoxylin and eosin stained sections, obtained by the method of de Sénarmont, were significantly lower in the aneurysm wall compared with the adventitial region of adjacent arteries. A similar reduction in retardation was found by imbibition analysis on unstained sections from three of the aneurysms. We propose that the difference in optical properties arises because the aneurysm collagen is immature and so is less organized at the molecular level. The presence of immature collagen could also explain the altered mechanical properties that are necessary for the enlargement and rupture of saccular aneurysms.

Adult↗

PubMed1988

Tracheal aspirates from neonates during endotracheal intubation: detection of surfactant by polarized light microscopy.

A technique for detecting the presence of pulmonary surfactant in the tracheal aspirates obtained from preterm babies is described. The specimens were examined by means of polarized light microscopy. Surfactant could be simply and rapidly identified by its appearance as birefringent particles in volumes of aspirate as little as 1 microliter. Tracheal aspirate specimens from 108 babies, obtained on the first day of life, were examined without knowledge of the patient's clinical details. When the samples from each baby were subdivided into three groups on the basis of the amount of surfactant particles seen, this subgrouping corresponded well with the babies' ventilatory requirements at the time of sample collection. This method of detecting surfactant material may prove valuable in determining the degree of surfactant deficiency in individual preterm babies with respiratory illness.

Humans↗

PubMedDate not supplied

Binding of Mg2+, Cd2+, and Ni2+ to liquid crystalline NaDNA: polarized light microscopy and NMR investigations.

The interaction of the divalent metal ions Mg(2+), Cd(2+), and Ni(2+) with liquid crystalline NaDNA solutions (molar ratios Me(2+)/DNA-phosphate </=0.050) was investigated by polarized light microscopy and multinuclear (31)P, (2)H, and (23)Na NMR. Our findings show that the state of the cholesteric NaDNA phase at equal MgCl(2), CdCl(2), or NiCl(2) concentration is affected in a different way and to a different extent by the nature of the divalent cation. Indeed, we found that the occurrence of an isotropic phase is markedly favored by Mg(2+), and to a lower extent by Cd(2+), and that the pitch of the cholesteric phase decreases in the presence of Cd(2+) or Ni(2+). (23)Na NMR spectroscopy also shows differences between the binding behavior of Mg(2+) and the transition metal ions in the counterion atmosphere around DNA. The results are discussed in terms of different binding modes of the metal ions.

Cadmium↗

PubMed1997

Effect of amiodarone on the lung shown by polarized light microscopy.

OBJECTIVE: To show lipid deposits in the lung of patients treated with amiodarone. MATERIALS AND METHODS: Formalin-fixed, unstained frozen sections were used to reveal lipid deposits by means of polarized light. Lung tissues obtained at the postmortem examination of one patient and the surgical biopsy of another were available. RESULTS: Birefringent lipid deposits were seen in the alveolar lining cells and macrophages, as well as in the walls of arterioles and venules. CONCLUSIONS: To assess the effect of amiodarone on the lung, polarized light microscopy of unstained, frozen sections is a simple and rapid method.

Amiodarone↗

PubMed1991

Demonstration of quantitative fabric analysis of tendon collagen using two-dimensional polarized light microscopy.

The extensional behavior of tendon is closely linked to the directional organization of the collagen fibers in the tendon. We sought to demonstrate that quantitative information about this organization is accessible through the application of polarized light microscopy. Ten tendons (2 canine Achilles and 8 rat tail tendons) were sectioned in a longitudinal plane and stained with either hematoxylin and eosin or toluidine blue. One Achilles tendon was fixed without tension on the fibers, thus leaving the fibers in a wavy state, and the other was fixed while strained with longitudinal tension straightening the fibers. One hundred measurements of collagen fiber orientation were made on a 0.7 mm2 area from each tendon. Recorded orientation angles were plotted on circular histograms and analyzed using circular statistics. The strained fibers revealed a sharply peaked distribution, in contrast the unstrained fibers had a bimodal orientation distribution. The tail tendons were fixed at strains from 0-3%. Analysis of the orientation distributions revealed increasing alignment of the collagen as strain increased. These data, while matching the qualitative descriptions of the fibers, also provide quantitative assessment of organization enabling comparison among tissues of varied physical circumstances and function. This method of quantitative orientation measurement has wide application for the many birefringent tissues such as bone, smooth and striated muscle and elastin.

Achilles Tendon↗

PubMed1977

Use of polarized-light microscopy in histological diagnostics of early stages of ischaemic and metabolic myocardial lesions.

Animal experiments have proved that the earliest morphological manifestations of acute lesions of myocardial cells (at the optical microscopic level) are myofibrillar changes detectable by polarized-light microscopy. As basic types of myocardial cell lesions there can be distinguished segmental and subsegmental contractures, intracellular myocytolysis, and primary granular disintegration. These changes persist in animal myocardium for many hours and thus can be recognized at autopsy. The application of polarized-light microscopy makes possible a diagnosis of early stages of myocardial infarction, associated with lesions of myocardial cells appearing at the periphery of the ischaemic zone already within the first minutes, revelation of focal metabolic changes leading to acute heart failure, and diagnosis of ventricular fibrillation, characterized by subsegmental contractures of the subepicardial and subendocardial layers of the myocardium.

Animals↗

PubMed1999

Morphological asymmetry in anterior limb of human internal capsule revealed by confocal laser and polarized light microscopy.

The fiber structure in the anterior limb of the internal capsule was investigated in a region where stereotactic lesions (anterior capsulotomy) result in successful treatment of obsessive-compulsive disorder (OCD). Eight human hemispheres were sectioned in comparable planes parallel to the ACPC plane. Microscopic slices were labeled with DiI and analyzed with confocal laser and polarized light microscopy. Three distinct systems of fibers were detected. Single fibers run from the caudate nucleus to the lentiform nucleus. The anterior thalamic peduncle connects the mediodorsal and partially the anterior thalamic nucleus with the frontal lobe. The frontopontine tract system connects the frontal lobe with the pons. This fiber tract occupies 38% of the anterior limb and is arranged in small bands. Right-left comparison of morphometric parameters of these bundles demonstrated that more and smaller bundles were located on the left-hand side than on the right-hand side. Tendencies for this configuration were noticeable in all brains investigated, with statistical significance in one brain. These morphological differences correlate with functional differences, as it was possible to demonstrate right hemispheric dysfunctions in cases of OCD. The benefit of anterior capsulotomy in OCD is generally seen in the interruption of fronto-basal ganglia-thalamic loops by disconnecting the anterior thalamic peduncle. In addition, the frontopontine fiber tract is disconnected in this stereotactic procedure.

Aged↗