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PubMed1993

A new case of isolated trichothiodystrophy.

We describe a new case of isolated trichothiodystrophy. This entity is characterized by sparse and brittle hair, low sulfur hair content, tiger tail pattern of the hair under polarizing microscopy, clean transverse fractures through the hair shaft and absent or defective hair cuticles. To our knowledge there are only two reported cases of isolated trichothiodystrophy without associated additional ectodermal or neuroectodermal dysplasias. Polarized microscopy of cut hair showed transverse fracture points (trichoschisis) and alternating dark and bright bands. Low sulfur content of the hairs was confirmed by amino acid analysis. Many acronyms and eponyms have been created to describe sulfur-deficient brittle hair associated with neuroectodermal abnormalities, leading to confusion. We suggest to use a simple classification scheme, according to increasing severity of associated features as proposed by Van Neste.

Child, Preschool↗
PubMed2003

Influence of insulin therapy on burn wound healing in rats.

BACKGROUND: Insulin is proposed as a therapy for suppressing muscle wasting after burn trauma although the long-term effects of this therapy on wound healing are not yet known. The present study was designed to investigate the effect of systemically administered insulin therapy on burn wound healing. MATERIALS AND METHODS: Young rats weighing 80-150 g were subjected to 15-20% total body surface area burn injury on their shaved dorsum. The insulin dosage was increased over the first 3 days in each rat from 0.25 U (Day 1), 0.5 U (Day 2), and 1.0 U (Day 3) per 100 g body wt. The rats were euthanized at the fourth or fifteenth day postinjury. Skin sections were analyzed by histochemistry and quantitative polarization microscopy. RESULTS: Histology showed a decreased number of inflammatory cells and increased vasodilation in the insulin-treated animals at Day 4 relative to untreated rats; at Day 15 there was increased reepithelialization. Quantitative analysis using polarization microscopy and picrosirius red staining showed an increased collagen deposition in wounds by Day 4 in insulin-treated rats relative to untreated burn controls. CONCLUSION: These results indicate that insulin induces accelerated wound healing associated with diminished inflammation and increased collagen deposition.

Animals↗
PubMed2006

Magnon excitation with spin-polarized scanning tunneling microscopy.

Using spin-polarized scanning tunneling microscopy, the local excitation of magnons in Fe and Co has been studied. A large cross section for magnon excitation was found for bulk Fe samples while for thin Co films on Cu(111) the cross section linearly scales with film thickness. Recording inelastic tunneling spectra with Fe coated W tips in a magnetic field, the magnonic nature of the excitation was proven. Magnon excitation could be detected without the use of a separating insulating layer opening up the possibility to directly study magnons in magnetic nanostructures via spin-polarized currents.

Journal Article↗
PubMed1975

Occurrence of amyloid in the teeth-supporting tissues of patients with rheumatoid diseases. An immunohistochemical study.

An investigation was carried out to determine whether amyloid could be detected in the dental periapical lesions or gingival buccal fold, or in both, of patients with rheumatoid disease but in whom amyloidosis had not been diagnosed. Tissue from the dental periapical lesions of 36 rheumatoid and 23 control patients, as well as from the gingival buccal fold of 11 of the rheumatoid and 11 of the control patients, were examined by the direct immunofluorescence technique and by polarization microscopy of sections stained with Congo red. Amyloid was observed almost 5 times more often, or in 19% of the dental periapical lesions of rheumatoid patients: it was detected by immunofluorescence in 7 rheumatoid patients and 1 control patient, and by polarization microscopy in 6 of these 7 rheumatoid patients as well as in the 1 control. Rectal biopsies performed on these 8 patients were positive in only 1 of the rheumatoid patients. Amyloid was not detected in any of the gingival biopsies. Serum samples from the rheumatoid and the control patients were tested for the presence of the nonimmunoglobulin amyloid fibril-related serum component, protein ASC. Nineteen of the 36 rheumatoid patients, including the 7 whose dental periapical lesions contained amyloid, had protein ASC in their serum.

Adult↗
PubMed1994

Liquid crystalline order of biopolymers in cuticles and bones.

Microscopic studies at different scales have shown that in biological tissues the three-dimensional arrangement of chitin-protein or of collagen fibrillar networks can follow the same spatial distributions as those described in certain liquid crystals. The present work reviews the structural analogies established between the dense fibrillar organic matrix found in two materials: crab cuticles and compact bones. In both systems mobile fringes are described in polarizing microscopy, periodic cleavage aspects in scanning electron microscopy (SEM), and arched patterns in transmission electron microscopy (TEM). In parallel to these structural data, results obtained in vitro are recalled which corroborate the relationship established between ordered arrays of biopolymers and liquid crystalline assembly principles, highly concentrated solutions of purified collagen molecules spontaneously form ordered assemblies characterized in polarizing microscopy as cholesteric phases. This particular state of matter joins both fluidity and order and could correspond to a transient state of collagen or chitin secretion, before the stiffening of these skeletal structures, bone or cuticle, by molecular cross-links and crystalline deposition.

Adult↗
PubMed1979

Studies on conformational changes in F-actin of glycerinated muscle fibers during relaxation by means of polarized ultraviolet fluorescence microscopy.

By means of polarized ultraviolet fluorescence microscopy the conformational changes of F-actin occuring in glycerinated muscle fibers of rabbit and barnacle (Balanus rostratus Hock.) under the influence of adenosine triphosphate in the presence of ethylene glycol bis(beta-amino-ethyl ether)-N,N'-tetraacetic acid were discovered. These changes seem to be located near the surface of the globules thus hampering the penetration of univalent iones and neutral molecules into the F-actin macromolecule. It is suggested that similar changes of F-actin take place in thin myofilaments of living muscle fiber during the contraction-relaxation process.

Actins↗
PubMed2001

Evaluation of crystals in formalin-fixed, paraffin-embedded tissue sections for the differential diagnosis of pseudogout, gout, and tumoral calcinosis.

Hematoxylin-eosin (H&E)-stained sections may not allow proper evaluation of birefringence properties of the crystals in the lesions of pseudogout, gout, and tumoral calcinosis. This study was undertaken to verify the application of a special stain that could facilitate the evaluation of the birefringence properties of these crystals for definitive diagnosis. We evaluated previously described nonaqueous alcoholic eosin staining (NAES) method based on the principle of using alcoholic eosin without hematoxylin and any other aqueous reagents for staining of formalin-fixed, paraffin-embedded tissue sections. Two observers, in a blinded fashion, evaluated the sections stained with routine H&E and NEAS method without the knowledge about clinical diagnosis. All pseudogout (nine sections from seven cases) and gout (eight sections from five cases) lesions demonstrated birefringence in the sections stained with NAES method. H&E-stained sections showing the respective diagnostic histomorphology failed to demonstrate the birefringent crystals by polarizing microscopy in all the eight sections from gout and in seven of nine sections from pseudogout. Only two H&E-stained sections showed scant calcium pyrophosphate dihydrate (CPPD) crystals in pseudogout. None of the three sections from two cases of tumoral calcinosis showed birefringence with either stain. We conclude that CPPD in pseudogout and monosodium urate in gout may not polarize in the routine H&E-stained sections. However, polarizing microscopy of sections stained with NAES method allowed demonstration of CPPD crystals with positive birefringence in pseudogout, MSU crystals with negative birefringence in gout, and calcium hydroxyapatite crystals without birefringence in tumoral calcinosis. Section stained with NAES method is a significantly useful adjunct to the routine H&E stain for proper evaluation of the crystals under polarizing microscope in these lesions.

Calcinosis↗
PubMed2006

[Effects of taurine on type I and III collagen expression in rats lung exposed to silica].

OBJECTIVE: To evaluate the effects of taurine in diet on the expression of type I and III collagen and collagen ratio at different time points in rats lung by image process technology. METHODS: Wistar rats were randomly divided into three groups: the saline instilled with a control diet (the saline treated group); silica instilled with a control diet (the silica treated group); and silica instilled with a diet containing 2.5% taurine (the taurine treated group). Animal models were established by the direct tracheal instillation of silica into rat lungs exposed surgically. The taurine concentration of serum was analyzed by means of HPLC. Paraffin embedded lung sections were stained with Sirius red. Polarization microscopy and Image Pro Plus Version 4.5 for windows were used for detecting type I and III collagen. RESULTS: The concentration of taurine in serum of the taurine treated group was significantly elevated compared to the saline treated and silica treated group (P < 0.05 or P < 0.01). Sirius red polarization microscopy showed that type I and III collagen positive area percentage were elevated in the silica treated rats compared with the saline treated group. On the 7th, 14th, 21st, 28th day after silica instillation type I collagen positive area percentage was increased by 3.84, 3.77, 3.73, 9.83 respectively (P < 0.01), and type III collagen positive area percentage were elevated by a little in the silica treated rats compared with saline treated group. The taurine treatment significantly decreased elevation of silica type I collagen positive area percentage of lung by 2.39, 1.62, 7.13 at the 7th, 21st, 28th day respectively (P < 0.05 or P < 0.01), and type III collagen positive area percentage of lung by 2.62 at the 28th day (P < 0.05) compared with the silica treated group. The ratio of type I to III collagen was increased from the 7th day to 28th day after silica instillation, and reached 1.87 at the 28th day with the maximal ratio in the silica-treated group. CONCLUSION: Treatment with taurine can effectively attenuate type I and III collagen expression in the rat lung induced by silica particles at different time points in our study.

Animals↗
PubMed2004

Unilateral coronal synostosis: a histomorphometric study.

OBJECTIVE: This histomorphometric study compared the open and prematurely fused side of the coronal suture in subjects with unilateral coronal synostosis (UCS). METHODS: Sutures and parasutural bone were obtained from seven subjects with nonsyndromic UCS during operative correction at 3 to 24 months of age. Histological and cellular analyses were performed for the affected and open sutures. Specimens were examined by light and polarizing microscopy. Sutural patterns, osseous morphology, calvarial thickness, tartrate-resistant acid phosphatase (TRAP)-positive cells, and marrow spaces were evaluated histomorphologically, qualitatively, and semiquantitatively. Histomorphometry was performed to determine total projected area of marrow space as a percentage of unit area, total number of TRAP-positive cells per specimen, and perisutural cranial thickness. RESULTS: Polarizing microscopy showed that affected sutures were composed of more lamellar bone than the normal sutures. By light microscopy, the clinically fused sutures were 1.7-fold thicker (p <.02), had twofold larger marrow spaces (p <.0006), and contained sixfold more TRAP-positive osteoclasts in marrow spaces near the suture (p <.04) than the normal sutures. Quantitative analysis of the normal sutures revealed that calvarial thickness was greater with age and that there was an inverse correlation between medullary area and age. For the affected sutures, there was also an age-related increase in calvarial thickness. There were also trends for age-related declines in numbers of osteoclasts in both open and affected sides. CONCLUSIONS: These results question the hypothesis that defective osteoclastic activity is pivotal in the pathogenesis of UCS and support the hypothesis that this condition results from abnormally active bony remodeling.

Bone Density↗
PubMed2004

Laser irradiation of the guinea pig basilar membrane.

BACKGROUND AND OBJECTIVES: The cochlea is the part of the inner ear that transduces sound waves into neural signals. The basilar membrane, a connective tissue sheet within the cochlea, is tonotopically tuned based on the spatial variation of its mass, stiffness, and damping. These biophysical properties are mainly defined by its constituent collagen fibers. We sought to assess the effect of laser irradiation on collagen within the basilar membrane using histological analysis. STUDY DESIGN/MATERIALS AND METHODS: Four excised guinea pig cochleae were stained with trypan blue. From these, two were irradiated with a 600 nm pulsed dye laser and two were used as controls. Collagen organization was visualized using polarization microscopy. RESULTS: Laser irradiation reduced the birefringence within the basilar membrane as well as within other stained collagen-containing structures. Larger reductions in birefringence were measured when more laser pulses were given. The effects were similar across all turns of each cochlea. CONCLUSIONS: Laser irradiation causes immediate alterations in collagen organization within the cochlea that can be visualized with polarization microscopy. These alterations may affect cochlear tuning. Ongoing research is aimed at analyzing the effect of laser irradiation on cochlear function. It is conceivable that this technique may have therapeutic benefits for patients with high-frequency sensorineural hearing loss.

Animals↗
PubMedDate not supplied

Molecular chain orientation of DNA films induced by both the magnetic field and the interfacial effect.

DNA films showing highly homogeneous orientation of molecular chains were successfully prepared by drying a semidiluted solution in a horizontal magnetic field. Most of the molecular chain elements in the obtained film were found to be one-dimensionally oriented, as shown by X-ray diffraction, polarization microscopy, and linear dichroism spectroscopy. Because a DNA chain is theoretically expected to orientate only in divergent directions perpendicular to a magnetic field, this result suggests that the DNA chains were aligned not only by a magnetic field but also by the interfacial effect that induced the chains to fit along the air-liquid interface. The descent speed of an air-liquid interface by evaporation was faster than the estimated diffusion rate of DNA, suggesting an emergence of a concentrated layer near the surface. As proved by polarization microscopy, this emergence led to the transitional formation of a nematic-like liquid crystalline phase, which resulted in a DNA film with good chain alignment and unitary orientation. This mechanism underlying chain alignment was supported by molecular weight dependency, in which higher molecular weight DNA is more likely to evince chain alignment that exhibits a higher degree of birefringence. Low molecular weight components have such high thermal motility that it would be difficult to fit them along the air-liquid interface in the early stage of drying. For chain alignment, it was preferable to use an initial concentration of DNA lower than a critical concentration for liquid crystal formation so that the possible diffusion and assembly in a diluted solution would be essential for chain alignment. The DNA film exhibited obvious linear dichroism, indicating the potential for further applications.

Air↗
PubMed1999

Solid State Transitions of Asymmetric Catanionic Surfactants.

A series of asymmetric surfactants were prepared from cationic surfactant, hexadecyltrimethylammonium bromide, and anionic surfactant, sodium alkyl sulfate (the number of carbon atoms per chain being 10, 12, or 14). The influence of the alkyl chain asymmetry on the thermal properties of formed hexadecyltrimethylammonium alkyl sulfates was investigated by means of polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. Asymmetric catanionic surfactants exhibited a complex polymorphism and thermotropic mesomorphism from the stable crystalline form to the isotropic phase. On heating, successive phase transitions (several solid crystalline-solid crystalline, solid crystalline-liquid crystalline, and liquid crystalline-isotropic liquid) were observed. The number of polymorphs, in all of the bilayered structure, depended on the asymmetry between the lengths of surfactant tails. The basic lamellar thickness varied linearly with the increase of alkyl sulfate chain length. An increase of the basic lamellar thickness with temperature was determined. Polarizing microscopy revealed a characteristic texture of the smectic phase. On cooling, all compounds underwent reversibly the isotropic liquid-liquid crystalline transitions, while crystallization from melted samples was kinetically controlled. Copyright 1999 Academic Press.

Journal Article↗
PubMed1991

Patterns of myocardial fibrosis in idiopathic cardiomyopathies and chronic Chagasic cardiopathy.

OBJECTIVE: To study the fibrillar nature and structural features of the collagenous interstitium of the myocardium in normal and cardiomyopathic human hearts, employing the picrosirius red technique and polarization microscopy. DESIGN: A survey, case series study. SETTING: Referral autopsy service at a university medical centre (Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto). CASES AND METHODS: A total of 46 adult hearts obtained at autopsy were used: five control hearts without evidence of cardiac disease, nine hearts with dilated cardiomyopathy, five with hypertrophic cardiomyopathy, four with endomyocardial fibrosis affecting the left ventricle, and 23 with chronic Chagasic cardiopathy. Fragments of myocardial tissue were obtained from the equator of the left ventricular free wall, fixed in formalin, dehydrated, and embedded in paraffin. Sections were stained with a modification of the picrosirius red technique and examined using direct light and polarization microscopy. RESULTS: The findings in the control myocardium did not differ from those reported in the literature. The myocardium in both dilated and hypertrophic cardiomyopathies showed diffuse fibrosis varying in degree from one case to another, but present in all cases. The basic pattern was characterized by a diffuse increase in both endomysial and perimysial collagen thick fibres, particularly surrounding individual myocytes (endomysial sheath). The microscopic study of the cases of endomyocardial fibrosis showed a thickened fibrotic endocardium consisting predominantly of thick collagen fibres extending as a septum, corresponding to broad perimysial sheaths, into the myocardium. In the superficial muscle fibre bundles usually composed of atrophic fibres, there was an increase in thickness of collagen fibres in both the perimysial and endomysial connective tissue matrix. To a variable degree (but present in all cases) interstitial and diffuse fibrosis could be observed in the chronic myocarditis of Chagas's disease. This was manifested by a diffuse increase in the amount of thick collagen fibres surrounding muscle fibre bundles (perimysial matrix), varying in intensity from one area to another, and around intramural coronary vessels, combined with a less pronounced increase in the endomysial collagen matrix. CONCLUSIONS: These findings extend knowledge of the various expressions of interstitial myocardial fibrosis in the idiopathic cardiomyopathies and chronic Chagasic cardiopathy and perhaps provide insight into pathogenesis. Further research into the patterns and pathogenesis of myocardial fibrosis are needed in order to offer prevention and corrective forms of therapy of the fibrotic process.

Adult↗
PubMed1977

The storage lipids in Tangier disease. A physical chemical study.

The physical states and phase behavior of the lipids of the spleen, liver, and splenic artery from a 38-yr-old man with Tangier disease were studied. Many intracellular lipid droplets in the smectic liquid crystalline state were identified by polarizing microscopy in macrophages in both the spleen and liver, but not in the splenic artery. The droplets within individual cells melted sharply over a narrow temperature range, indicating a uniform lipid composition of the droplets of each cell. However different cells melted over a wide range, 20-53 degrees C indicating heterogeneity of lipid droplet composition between cells. Furthermore, most of the cells (81%) had droplets in the liquid crystalline state at 37 degrees C. X-ray diffraction studies of splenic tissue at 37 degrees C revealed a diffraction pattern typical of cholesterol esters in the smectic liquid crystalline state. Differential scanning calorimetry of spleen showed a broad reversible transition from 29-52 degrees C, with a maximum mean transition temperature at 42 degrees C, correlating closely with the polarizing microscopy observations. The enthalpy of the transition, 0.86+/-0.07 cal/g of cholesterol ester, was quantitatively similar to that of the liquid crystalline to liquid transition of pure cholesterol esters indicating that nearly all of the cholesterol esters in the tissue were free to undergo the smectic-isotropic phase transition. Lipid compositions of spleen and liver were determined, and when plotted on the cholesterol-phospholipid-cholesterol ester phase diagram, fell within the two phase zone. The two phases, cholesterol ester droplets and phospholipid bilayers were isolated by ultracentrifugation of tissue homogenates. Lipid compositions of the separated phases approximated those predicted by the phase diagram. Extracted lipids from the spleen, when dispersed in water and ultracentrifuged, underwent phase separation in a similar way. Thus (a) most of the storage lipids in the liver and spleen of this patient were in the liquid crystalline state at body temperature, (b) the phase behavior of the storage lipids conformed to that predicted by lipid model systems indicating lipid-lipid interactions predominate in affected cells, (c) lipid droplets within individual cells have similar compositions, whereas droplet composition varies from cell to cell, and (d) cholesterol ester does not accumulate in the splenic artery. Since Tangier patients lack high density lipoprotein, we conclude that high density lipoprotein-mediated cholesterol removal from cells is essential only for those cells which have an obligate intake of cholesterol (macrophages).

Adult↗
PubMedDate not supplied

Cocrystallization model for synthetic biodegradable poly(butylene adipate-co-butylene terephthalate).

Synthetic biodegradable poly(butylene adipate-co-butylene terephthalate), P(BA-co-BT), with 56 mol % butylene adipate, BA, was characterized by solid-state NMR spectroscopy, thermal analysis, X-ray diffraction, computer modeling, and polarization microscopy. The NMR study showed the presence of BA and butylene terephthalate, BT. T(1C) NMR measurements proved that some BA and BT units were in crystalline regions. Thermal analysis showed one glass-transition temperature and a single diffuse melting endotherm corresponding to a large melting-point depression of about 100 degrees C compared with poly(butylene terephthalate), PBT. These results suggest that there is only one crystalline phase. An X-ray fiber diagram of a stretched film could be indexed with the same unit cell as that for PBT. Computer modeling showed that the adipate unit fits into the crystal structure of PBT by adopting a TTGTG dihedral angle sequence in the crystalline conformation proposed for the cocrystallization model. The predicted fiber diagram from the proposed model qualitatively agrees with the experimental one. Polarization microscopy revealed that the spherulite growth rate of P(BA-co-BT) was similar to that for poly(butylene adipate), PBA.

Absorbable Implants↗
PubMed1977

Thermal behavior of human plasma high density lipoprotein.

Human plasma low density lipoprotein displays a reversible thermal transition between 20 and 40 degrees C, due to a phase transition of its core cholesterol ester from a smectic to a more liquid-like state. To determine if the cholesterol of high density lipoprotein (HDL) displays similar thermal behavior, the human lipoprotein and its extracted lipid have been examined by differential scanning calorimetry, low angle X-ray scattering and polarizing microscopy. Neither HDL2**(d 1.063--1.125--1.21 g/ml) nor HDL3(d1.125--1.21g/ml) show thermal transitions between O and 60 degrees C. By contrast cholesterol ester isolated from HDL and mixtures of cholesterol oleate and linoleate show reversible liquid crystalline transitions between 20 and 40 degreesC. X-ray scattering studies of HDL2 and HDL3 performed at 10 degreesC show no scattering fringes attributable to a smectic phase of cholesterol ester. When HDL is heated to temperatures above 60 degreesC a broad, double-peaked endotherm is observed. The first component (peak temperature=71 degreesC) corresponds to a selective release of apoprotein A-1 from the lipoprotein, and the second component (peak temperature=90 degreesC) to a more generalized disruption of lipoprotein structure with release of cholesterol ester and apoprotein A-2. Following the thermal disruption of HDL, reversible liquid crystalline transitions of cholesterol ester can be seen by differential scanning calorimetry and polarizing microscopy, showing the presence of large domains of cholesterol ester. The absence of cholesterol ester transitions in intact HDL may indicate an interaction of cholesterol ester molecules with the protein-phospholipid surface of HDL that prevents the formation of an organized lipid phase. The high temperature behavior of HDL indicates that apoprotein A-1 is less important than apoprotein A-2 in maintaining the HDL apolar lipids in the form of a stable miroemulsion.

Calorimetry↗
PubMed2004

Evaluation of meiotic spindles in thawed oocytes after vitrification using polarized light microscopy.

OBJECTIVE: To investigate the efficacy of the PolScope on imaging the spindle morphology in oocytes at the metaphase II stage before vitrification and after thawing. DESIGN: In vitro study. SETTING: University infertility clinic and academic research laboratory. INTERVENTION(S): Oocytes at the metaphase II stage that were obtained from superovulating mice were vitrified and then thawed. MAIN OUTCOME MEASURE(S): Morphological features of the spindle in oocytes were evaluated by both the PolScope and immunofluorescent staining. RESULT(S): Using the PolScope, the morphological features of the spindle of intact thawed oocytes were undetected by 3 hours of thawing in only 25% of cases. Most of the spindle images were recognized during the first hour of observation. Additionally, the statistical analysis of agreement of spindle morphology by both the PolScope and fluorescent staining showed a weighted Kappa value of 0.70, indicating good agreement. Oocytes with good spindle morphology verified by the PolScope before vitrification had a higher survival rate of intact oocytes after thawing compared with those with poor or undetected spindle images. CONCLUSION(S): The morphological features of the spindle in oocytes evaluated by the PolScope before freezing and after thawing are significantly correlated with those assessed by immunofluorescent staining after fixation. With the assistance of the PolScope, thawed oocytes with good spindle morphology can be verified and selected for further manipulation without fixation and staining.

Animals↗