Gout and pseudogout established by polarized light microscopy of synovial fluid. Methods and two case reports.
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Aged↗
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Results for “Microscopy, Polarization”
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A study of the carious lesion utilizing radiography, polarized light microscopy, and scanning electron microscopy.
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Dental Caries↗
Spindle dynamics in living mouse oocytes during meiotic maturation, ageing, cooling and overheating: a study by polarized light microscopy.
A liquid crystal polarized light microscope (LC PolScope) was used to examine spindle dynamics in living mouse oocytes. Immature oocytes were cultured for 0-48 h and spindles were imaged with the PolScope at various time points of culture. Oocytes at metaphase I (M-I) and metaphase II (M-II) were also exposed to shifts of temperature from 25 to 41 degrees C to examine the effects of fluctuations of temperature on spindle dynamics. After examination with the PolScope, some oocytes were fixed and examined by immunocytochemical staining and confocal microscopy. After culturing for 6 h, 76% and 2% of the oocytes reached M-I and M-II stages and all oocytes had birefringent spindles. When the oocytes were cultured for 14-16 h, 88% and 6% of oocytes were at M-II and M-I stages respectively and all oocytes had birefringent spindles. However, when the oocytes were cultured for 22-48 h, the proportions of oocytes with birefringent spindles decreased as culture time was increased. Exposure of oocytes to 25 degrees C induced spindle disassembly within 10-20 min in both M-I and M-II oocytes. Most (93-100%) oocytes reassembled spindles after warming at 37 degrees C. Furthermore, exposure of oocytes at M-I stage but not at M-II stage, to 30 degrees C also induced significant microtubule disassembly. However, exposure of oocytes to 38-41 degrees C did not obviously change the quantity of microtubules in the spindles, which was measured by retardance. This study indicates that the PolScope can be used to examine spindle dynamics in living oocytes, and it has the advantage over the routine fluorescence microscope in that images can be obtained in the same individual oocyte and the quantity of microtubules can be measured by retardance in living oocytes. These results also indicate that the M-II spindle in mouse oocytes is sensitive to oocyte ageing and cooling, but not heating, and M-I spindle is more sensitive to temperature decline than M-II spindle.
Animals↗
Calcium oxalate microcalcifications in the breast.
Calcium oxalate calcifications can be difficult to detect with routine histologic procedures. In the reported case, microcalcifications that were evident with radiography of the specimen and of the paraffin blocks could not be detected with light microscopy. Polarized light microscopy, however, revealed the calcifications to be calcium oxalate crystals. Use of polarized light microscopy may resolve radiologic-pathologic discrepancies in such cases.
Adult↗
The lipid composition of drusen, Bruch's membrane, and sclera by hot stage polarizing light microscopy.
PURPOSE: To detect and identify, in situ, the lipid composition of drusen, diffuse Bruch's membrane deposits, and sclera in aging human eyes using hot-stage polarizing microscopy (HSPM), a method that allows qualitative determination of lipid subtypes within histologic sections based on morphology and melting temperatures of liquid crystals as monitored by birefringence during heating and cooling. METHODS: Full-thickness buttons of the central macula and the periphery of human eyes from 17 patients were fixed in 5% calcium-buffered formalin. Frozen sections were stained with oil red O or Sudan black or were analyzed by HSPM. RESULTS: Birefringent anisotropic droplets ("maltese crosses") with melting characteristics of cholesterol esters were identified within diffuse Bruch's membrane deposits, drusen, and sclera. Deposits that melted from crystal to oil without any maltese cross formation when cooled were present in the sclera and are consistent with triglyceride-rich deposits. Deposits with optical properties consistent with phospholipids were identified in a single aged eye. Eyes from young donors did not show these changes. CONCLUSIONS: HSPM is a valuable technique for evaluating the nature of lipid deposits in aging eyes. Further studies are warranted to determine whether similar changes are also present in eyes with age-related macular degeneration.
Adolescent↗
Fibrosis in the transplanted heart and its relation to donor ischemic time. Assessment with polarized light microscopy and digital image analysis.
Long-distance procurement of cardiac allografts is commonly used to increase the supply of donor organs but has recently been associated with the development of impaired diastolic function. Therefore, the effect of the total ischemic duration on myocardial fibrosis was quantitatively evaluated in 36 cardiac transplant recipients in whom the ischemic time ranged from 70 to 363 (mean, 189 +/- 83) minutes. Interstitial collagen was quantified with polarization microscopy and digital image analysis in 115 endomyocardial biopsy specimens taken 5-10 days after surgery. The technique, developed for this study, showed excellent correlation with hydroxyproline analysis (r = 0.98, p less than 0.001). Collagen volume fraction in biopsy specimens from the transplanted hearts was significantly greater than that in biopsy samples from seven normal, age-matched autopsy hearts (4.7 +/- 1.9% vs. 2.9 +/- 0.6%, p less than 0.02). The degree of fibrosis correlated with the total ischemic time (r = 0.60, p less than 0.001). Donor age ranged from 10 to 51 years and did not correlate with the degree of fibrosis. No relation was found between the corresponding collagen content and right atrial pressure, pulmonary artery wedge pressure, or cardiac output measured at the time of biopsy. Myocyte damage was observed in eight of the 36 patients and was characterized by a striking loss of muscle birefringence. We conclude that cardiac allograft fibrosis may be identified shortly after transplantation and is dependent on the total ischemic duration.
Adult↗
The polarized light microscopy and ultrastructure of Polynesian pigmented tooth enamel.
Transmitted and polarized light microscopy of unerupted and erupted teeth affected by a pigmented anomaly found in two geographically isolated Polynesian populations, the New Zealand Maori and the French Polynesian Marquesas Islander, showed similar histological characteristics. Mounted in water, the pigmented areas were positively birefringent and covered with a thin negatively birefringent surface layer 200-250 microns thick. Cervical areas were negatively birefringent. Transmission electron microscopy of argon-ion-beam thinned specimens of affected enamel revealed large voids, disruption in the packing of crystals and spacing at prism boundaries. In the surface layer of enamel from erupted and unerupted teeth, the intra- and interprismatic spaces were occluded by fine crystals or amorphous material. A well-defined prism structure and close crystal packing were found in cervical enamel. The ultrastructure of these pigmented enamels was similar to and consistent with a hypomaturation type of amelogenesis imperfecta.
Birefringence↗
Quantitative in situ correlation between microscopic MRI and polarized light microscopy studies of articular cartilage.
OBJECTIVE: To establish the correlation between the non-invasive imaging by magnetic resonance microscopy (microMRI) and the histological imaging by polarized light microscopy (PLM) accurately, quantitatively, at the highest possible MRI resolution (13.7 microm), and based on the same piece of tissue (articular cartilage from canine shoulder joint). DESIGN: In microMRI experiments, the laminar appearance (the magic angle effect) of the proton intensity images and the anisotropic characteristics of the T(2)relaxation images were analysed. In PLM experiments, the images of the optical retardation and collagen-fibre orientation in cartilage were constructed in two dimensions. RESULTS: The T(2)profile has a distinctly asymmetric bell-shaped curve and three featured zones. The retardation profile has a non-zero minimum at the middle of the transitional zone of the tissue. The angle profile has a smooth variation across the transitional zone. These facts suggest that the collagen fibres in the transitional zone are not entirely random but have a residual order. In addition, the peak of the T(2)profile coincides with the minimum of the retardation profile, both represent the most isotropic region of the tissue. A hyperbolic tangent function was found to best describe the transition of the collagen fibres in cartilage. A set of criteria was developed for each technique to define the features in the quantitative measurements. CONCLUSIONS: The criteria offer, for the first time, a set of quantitative and objective means to subdivide the tissue thickness into the zones in histology and in MRI. It is shown that the microMRI zones based on the T(2)characteristics are statistically equivalent to the histological zones based on the collagen fibre orientation (t-probabilities of 0.730, 0.973, 0.647, 0.850 for the superficial, transitional, radial zones and the total thickness).
Animals↗
Growth hormone stimulates bone formation and strength of cortical bone in aged rats.
The influence of growth hormone on bone formation, mechanical strength, and composition has been investigated in femur middiaphyseal cortical bone from 2-year-old male rats. The rats were given biosynthetic human growth hormone (bhGH) at 2.7 mg/kg/day in two daily injections for 20, 40, or 80 days, and all animals were killed 80 days after the start of bhGH administration. Control animals were given saline. All animals were labeled with tetracycline on days 41 and 69. Only in the bhGH-80-day group was subperiosteal tetracycline double labeling seen all around the femur diaphysis, and this pattern was found in all animals of the group. Double labeling subperiosteally at the posteromedial aspect was found in all animals of the experiment, but compared with the control group, a 400% and an 800% increase in mineral apposition rate was seen in the bhGH-40-day and bhGH-80-day groups, respectively. Light microscopy and polarization microscopy showed that this newly deposited bone was organized in the same concentric lammellae and had the same direction of the collagen fibers when compared with the surrounding bone formed before the start of bhGH injections. The cortical bone cross-sectional area was increased in the bhGH-40-day and bhGH-80-day groups. At the endosteum, scattered labeling was found in animals from all groups, and no differences in medullary cross-sectional areas were seen. The mechanical analysis revealed an increased mechanical strength of the whole diaphyseal bone after bhGH administration. When the data were corrected for dimensions of the diaphyseal bone, no differences in intrinsic mechanical properties of the bone tissue were found. No differences in apparent density of dry defatted bone, ash, and collagen were seen, whereas apparent density of dry defatted bone minus ash was decreased in all groups given bhGH. Correspondingly, a slight increase in ash concentrations of the bhGH-injected animals was seen. bhGH administration also increased the body weight, muscle mass, and total serum IGF-I and thyroxine concentrations.
Aging↗
[Studies of the development of refractive effects in intrastromal refractive corneal surgery with the picosecond laser].
BACKGROUND: Picosecond laser intrastromal photorefractive keratectomy (ISPRK) aims at achieving a flattening of the central cornea by plasma-mediated tissue evaporation without affecting the anterior or posterior corneal layers. We investigated the laser-induced tissue effects to establish a functional relationship between laser parameters and tissue removal and to assess their influence on the healing process and long-term refractive changes. MATERIALS AND METHODS: A modified ISL 2001 System with a cone angle of 30 degrees was used for in vitro investigations of the laser effects in water and porcine cornea. Photographic methods were used to determine the plasma volume and the thickness of the laser-generated intrastromal bubble layer as a function of the pulse energy and the number and separation in which the pulses were applied (216 eyes). Histological evaluation was done by polarization microscopy (9 eyes). RESULTS: Polarization microscopy revealed only minor signs of thermal tissue damage. The maximum amount of tissue that can be evaporated without damaging the outer corneal layers corresponds to a layer about 10 microns thick. With a 6-mm optical zone, this tissue removal yields an immediate refractive effect of only 0.85 dpt. Stronger long-term refractive changes observed in animal experiments and clinical studies must thus be due to the healing response of the cornea. The healing response may be induced by mechanical distortion due to intrastromal bubble formation affecting about one third of the corneal thickness. CONCLUSION: Since the refractive effects are apparently strongly influenced by corneal healing, they are poorly predictable and can probably not be used for clinical purposes.
Animals↗
Surface quality of intraocular lenses.
We observed circular furrow-like patterns on the implanted intraocular lens surface in postoperative follow-up examination by specular microscopy. The patterns may have been deep lathe-cut marks or compression-related marks on the optics. Specular microscopy, polarized light microscopy, and scanning electron microscopy detected a similar circular mark on the optic surface of a control intraocular lens of the same model. A reconsideration of surface quality is indicated.
Aged↗
[A histopathological study on hypoplasia of the enamel].
The research on the development and injury of the hard tissue of teeth was studied by the pedodontic departments of nine dental schools. We participated in this research and studied histopathologically hypoplasia of the enamel in particular. There were seven selected teeth which had obvious hypoplasia of the enamel. We conducted observations with the naked eye, replica, general microscopy, polarized light microscopy, fluorescence microscopy, and microradiography. Moreover we studied to classify these cases into three types, that is to say, the injury factors of whole body, locality, and unknown origin. The results obtained were as follows. 1) As for the injury factors for the whole body, the bottom of the enamel defects were located corresponding to the incremental line of Retzius in the case of enamel hypoplasia of the deciduous teeth. Also enamel hypoplasia was located near the dentino-enamel junction corresponding to the surface of hypoplasia. 2) As for the injury factors with respect to locality, the bottom of enamel defects were located corresponding to the incremental line of Retzius. The dentino-enamel junction was irregular and discontinuous, still more a part of that area, and the dentin protruded or was exposed. 3) As for the injury factors of unknown origin, hypoplasia was located from the surface of the enamel but it did not spread. Also the hypoplasia of the enamel did not correspond to the incremental line of Retzius. 4) Five cases had fluorescence lines in enamel or dentin.
Dental Enamel Hypoplasia↗
[Structure and function of the fibrous structure of articular cartilage].
Structure of the articular cartilage fibrous stroma in the mature rabbit femoral heads has been studied and described by means demasking of fibres, of electron microscopy and polarization microscopy. A new scheme on the articular cartilage fibrous stroma structure is suggested, which differs from that of Benninghoff. A single fibrous cartilage framework consists of, at least, three networks of fibres directed to different sides. The role of every stromal part is interpreted in the whole function of the tissue.
Animals↗
Organization of DNA in dipteran polytene chromosomes as indicated by polarized fluorescence microscopy.
Analysis of the polarization of fluorescence from Drosophila virilis polytene chromosomes stained with acridine orange suggests that the DNA in the interband regions of these chromosomes cannot be in a supercoiled configuration, but must lie parallel to the chromosome axis.
Acridines↗
X-ray diffraction and polarizing optical microscopy investigation of the structural organization of rabbit tibia.
X-ray diffraction and polarized optical microscopy investigations were carried out on thin sections of rabbit tibia in order to study the morphological organization of the structural components of this tissue, which often is utilized to test bone response to implants. In the optical microscope, the lateral face as well as the lateral portion of the caudal face exhibit a lamellar structure with an alternation of dark and bright lamellae running parallel to the long axis of the tibia. In contrast, both in the medial face and in the medial portion of the caudal face there are numerous osteonic structures. In spite of the complexity of this morphological organization, the results of small- and high-angle X-ray diffraction analyses indicate that the structural relationship between collagen fibrils and inorganic crystals is quite similar to that observed in single osteons and allows evaluation of the orientation of the two main structural components. Both collagen fibrils and apatitic crystallites are preferentially oriented parallel to the long axis of the tibia. The degree of orientation is greater in the thickness than in the plane of the lamellae, suggesting that collagen fibrils and inorganic crystallites lie preferentially in the plane of the lamellae, where they follow an oblique course. The degree of orientation of the apatitic crystallites is higher in the lateral face than in the medial and caudal faces, in agreement with the optical microscopic images. The results provide information that must be taken into account when evaluating the structural modifications of bone due to the insertion of a prosthetic device.
Animals↗
Radial compression elasticity of single DNA molecules studied by vibrating scanning polarization force microscopy.
The radial compression properties of single DNA molecules have been studied using vibrating scanning polarization force microscopy. By imaging DNA molecules at different vibration amplitude set-point values, we obtain the correlations between radially applied force and DNA compression, from which the radial compressive elasticity can be deduced. The estimated elastic modulus is approximately 20-70 MPa under small external forces (<0.4 nN) and increases to approximately 100-200 MPa for large loads.
Compressive Strength↗
Detection of silica particles in lung tissue by polarizing light microscopy.
The detectability of silica particles in ordinary histologic sections by means of polarizing light microscopy has been controversial. Through the application of both correlative light microscopy and scanning electron microscopy to different lung sections, we showed that particles demonstrating peaks for silicon only by energy-dispersive x-ray microanalysis were in fact visible by polarizing light microscopy. These particles included some silica particles less than 1 microns in diameter. We found no correlation between the intensity level of the light source used for polarization and the differential ease of visualizing silica versus silicates; examples of both could be detected at both relatively low and high light intensities. This suggests that geometric parameters may be as important as composition in the ease of detection of silica versus silicates with polarized light.
Electron Probe Microanalysis↗
Selective imaging of 3D director fields and study of defects in biaxial smectic A liquid crystals.
We report on the selective imaging of different director fields in a biaxial smectic A (SmAb) liquid crystal using Fluorescence Confocal Polarizing Microscopy (FCPM) and Polarizing Microscopy (PM). The patterns of two directors, namely the director n(a) perpendicular to the lamellae and the director n(b) in their planes are visualized by doping the liquid crystal with two fluorescent dyes with different orientation of the transition dipoles with respect to the lamellar matrix. The properties of defects such as disclinations and focal conic domains (FCDs) are consistent with the non-polar D2h-symmetry of the SmA(b) mesophase in the studied mixture of bent-core and rod-like molecules: (1) majority of defects in the director n(b) are half-integer "+/-1/2" disclinations; (2) the integer-strength "+/-1" defects tend to split into the "+/-1/2" disclinations. We compare the vertical cross-sections of the "+/-1" disclinations in the field in SmA(b) and uniaxial nematic samples. In SmA(b), the "+/-1" disclinations do not escape into the third dimension, while in the nematic samples with Schlieren textures they do despite the surface anchoring at the plates; the experimentally determined director field around the escaped disclination capped by a pair of surface point defects--boojums matches the one predicted recently [C. Chiccoli et al., Phys. Rev. E 66, 030701 (2002)]. The FCD structure in SmA(b) is similar to that in SmA and SmC in terms of the normal to the layers but differs significantly in terms of the director n(b) field parallel to the smectic layers. The FCDs in SmA(b) can be associated with topologically non-trivial configurations of n(b) in the surrounding matrix that are equivalent to the disclination lines.
Journal Article↗