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PubMed1998

Cell death and proliferation and its relation to collagen degradation in uterine involution of rat.

Collagen concentration, procollagenase localization, and their association with cell proliferation and apoptosis during postpartum involution, were investigated biochemically and histochemically in postpartum day 1, 3, 5, and 7 rat uterine tissues. In control animals, uterine wet weight, soluble protein, and collagen decreased rapidly during days 1 to 3 postpartum, and the DNA concentration in the uterine horn rapidly decreased, as noted by others. Simultaneously, both apoptosis and cell proliferation were observed in these tissues. These processes were highest in smooth muscle cells on day 3 postpartum. Procollagenase was found in the cell cytoplasm through days 1 to 3 postpartum, was highest on the third day postpartum, and appeared to gradually diminish by day 5 postpartum. Disorganization of collagen fibers was observed, under polarized microscopy by a strong birefringence of collagen fibers of the circular smooth muscle cell layers. However, this disorganization of the uterine collagen diminished progressively from day 3 to day 7. Treatment with estradiol or a combination of estradiol and progesterone suppressed cellular turnover and attenuated the changes in DNA, total amino acids, and collagen on day 3 postpartum. In this study, cellular turnover and biochemical and morphological changes appeared to be closely associated. Gonadal steroid hormones appear to influence these changes and retard uterine involution. This study suggests that a dynamic turnover of the cellular population takes place during uterine involution. It is possible that other factors, in addition to steroid hormones, contribute to uterine involution. It is to be postulated that these factors either are themselves decreased or, alternatively, may increase the inhibition of other unknown factors by an indirect mechanism.

Animals↗

PubMed1996

Bilateral carpal tunnel syndrome secondary to tophaceous compression of the median nerves.

A 65-year-old man with long-term gouty arthritis developed bilateral carpal tunnel syndrome. At surgery a chalky substance, which showed negative birefringence on polarized microscopy, was found infiltrating around the intensely inflamed transverse carpal ligaments. In differential diagnosis of carpal tunnel syndrome, tophaceous compression over the median nerve should be taken into consideration.

Arthritis, Gouty↗

PubMed1994

Amyloidosis.

The biochemistry of amyloidosis as it relates to clinical medicine and experimental pathology is presented. Amyloidoses are complex disorders in which normally soluble precursors undergo pathological conformational changes and polymerize as insoluble fibrils with the beta-pleated sheet conformation. Over the past 20 years, 16 biochemically diverse proteins have been identified as fibrillar constituents of amyloid deposits; in all cases the protein-protein interactions that result in amyloid fibril formation appear to be stabilized both by the structure and the microenvironment of the precursor protein. Either genetic predisposition or dysfunctions of the immune system favor amyloid fibril formation. In particular, macrophage function is a factor in the pathogenesis of many of the amyloidoses. The diagnosis of amyloidosis involves acquisition of a tissue biopsy, staining of the specimen with Congo red, and observation of classic green birefringence on polarization microscopy. The subdiagnosis of the systemic amyloidoses involves characterization of variant or monoclonal plasma amyloid precursor proteins in the context of clinical symptoms. Treatment is generally supportive, with the use of antiinflammatory therapy, dialysis, or transplantation and genetic counseling where indicated.

Amyloid↗

PubMed1984

Myocardial catecholamines following cold cardioplegic arrest during open-heart surgery.

Preservation of both right and left ventricular subendocardial and subepicardial muscle was assessed using quantitative polarization microscopy (birefringence measurements) with preservation of myocardial catecholamines measured by fluorescence microscopy in biopsies from 20 consecutive patients who underwent open heart surgery with cold cardioplegic arrest (St. Thomas' Solution). Six of the 7 patients with clinical complications were predicted from the birefringence results. One developed left ventricular deterioration during bypass, two patients right ventricular deterioration, one patient both left and right ventricular deterioration and two patients had poor left ventricular function before bypass. Birefringence measurements were thus reliable in predicting post-operative cardiac outcome. There were no significant changes during the bypass period in the catecholamine scores, even in those patients who had clinical complications. Fluorescence microscopy showed that the "free" myocardial nerve net and the pericoronary nerve plexuses retained their catecholamine stores equally well. This indicated that St. Thomas' cardioplegia preserves myocardial catecholamine stores, depletion of which would remove a potentially important compensatory mechanism in cardiac pump failure. There may however be a temporary blockade in the release of endogenous cardiac catecholamine (noradrenaline) stores from the adrenergic nerve terminals following cold cardioplegic arrest despite myocardial pump failure.

Adult↗

PubMed2003

Fractionation of milk fat by short-path distillation.

Fractionation of milk fat by short-path distillation changes the chemical composition and physical properties of the resulting fractions. Increases in distillation temperature from 125 to 250 degrees C increased distillate yield from 0.3 to 42.7% (wt/wt). The distillate was enriched in short- and medium-chain fatty acids and low molecular weight acylglycerols, while the retentate was enriched in long-chain saturated and unsaturated fatty acids as well as high molecular weight acylglyerols. As distillation temperature increased, dropping points of the distillate increased. Relative to native milk fat, the solid fat content (SFC) vs. temperature melting profile of the distillate was depressed and that of the retentate was augmented, which correlated with the saturated long-chain fatty acid content in the fractions. Retentate crystallization parameters obtained by fitting the Avrami model to SFC-time data, did not change as a function of distillation temperature, but varied as a function of the degree of undercooling. Changes in microstructure observed by polarized light microscopy also appeared to be solely a function of the degree of undercooling, with no observable differences between retentates obtained at the different distillation temperatures. In addition, no changes in the retentate's free energy of nucleation (deltaGc) as a function of distillation temperature were found. The compressive storage modulus of the crystallized retentate increased as a function of increasing distillation temperature.

Animals↗

PubMed1999

Button battery impaction in nasal cavity.

A button battery inserted in the nose of children is an unusual foreign body which is capable of causing extensive tissue damage, resulting from electrical and chemical burns. We report a case of button battery in the nose of a 4-year-old boy presenting with unilateral nasal discharge, and necrosis in the septum and turbinate of the right nasal cavity. Mercury level in concentrated urine was within normal limit. Microscopic examination disclosed extensive liquefaction necrosis with calcification and fibrosis. Numerous dark brown to black granules were noted in the elastic and collagen fibers and interstitium. Dark-field examination of the section revealed brilliantly refractile granules. Polarized microscopy failed to show the granules. Most brown pigments reacted to prussian blue. Tissue mercury analysis yielded a mercury content of 8.01 ppm. We report this case to emphasize the hazards of button battery impaction and to draw attention to the significance of the problem through histopathologic examination.

Child, Preschool↗

PubMed2004

[Expression of transforming growth factor-beta1 in renal fibrosis of human mesengial proliferative glomerulonephritis].

OBJECTIVE: To explore the possible effect of transforming growth factor-beta(1) (TGF -beta(1)) on the development of renal fibrosis in human mesengial proliferative glomerulonephritis (MsPGN). METHODS: Immunohistochemistry method, sirius red staining polarization microscopy and the computer imaging analysis system were used to detect the expression of TGF-beta(1), the distribution of collagen I, collagen III and collagen IV. RESULT: In MsPGN with renal fibrosis, collagen IV was increased markedly,and collagen I and collagen III appeared in the expanded mesengial matrix abnormally. Collagen III and collagen IV were increased markedly in tubulointerstitium. TGF-beta(1) expression was positively correlated with the expression of collagen I, collagen III and collagen IV in tubulointerstitium (r=0.82 0.92,P<0.01), and negatively correlated with I/III, I/IV and III/IV (r=-0.83,-0.92, P<0.001). CONCLUSION: Abnormal increase of TGF-beta(1) may be one of the important factors associated with glomerular sclerosis and tubulointerstitial fibrosis through the increment and abnormal distribution of collagen I, collagen III and collagen IV.

Collagen↗

PubMed1976

Thermal properties of systems containing cholesteryl esters and triglycerides.

Binary and ternary systems of the three cholesteryl esters, linoleate, oleate, and stearate and the two triglycerides, triolein and tristearin were studied in order to determine the phase transitions and the conditions for the cholesteric and smectic mesophases. Phase transitions were determined using differential thermal analysis, melting point determination, and polarizing microscopy. Of the cholesterol esters the linoleate-oleate system showed complete miscibility in both the liquid and solid phases. The linoleate-stearate and oleate-stearate systems are of the eutectic type with limited solid solubility. The mesophases are monotropic as to the crystalline state and exist over the entire composition interval in all cholesteryl ester systems studied.

Chemical Phenomena↗

PubMed1989

The structure and development of osteogenetic repair tissue according to Ilizarov Technique in man. Characterization of extracellular matrix.

Distraction osteogenesis by the method of Ilizarov has permitted the study of bone formation. This is an analysis of 64 human biopsies in patients who were undergoing tibial lengthening by the method of Ilizarov. After analysis by conventional and polarized light microscopy, four stages of bone formation were identified. Bone formation is of the direct type with no cartilaginous phase.

Biopsy↗

PubMedDate not supplied

Evaluation of perfusion conditions in cardiopulmonary bypass.

Fresh sections of left ventricular drill biopsies, taken at the beginning and end of cardiopulmonary bypass in 164 patients undergoing aortic valve replacement, have been analyzed for myocardial function. This has been assessed by changes in biochemical function, measured by semi-quantitative histochemical methods, and by changes in birefringence, measured quantitatively by polarization microscopy. It has been shown that continuous perfusion at 32 degrees C with the heart beating provided better preservation than did the other three perfusion procedures, in all of which the heart was fibrillating. More recently, in a small number of cases, cardioplegic arrest has been found to given even better preservation.

Aortic Valve↗

PubMedDate not supplied

Ann Otol Rhinol Laryngol [Suppl].

Mandibular replacement subsequent to major extirpative head and neck surgery is predisposed to complications in the best of hands. The most suitable prosthesis appears to be the previously resected mandible, both from the standpoint of antigenicity and configuration. This study establishes that in the canine mandible a healthy, revitalized osseous network is reestablished subsequent to resection, freezing and replacement of the mandibular body when the graft is immobilized. The neoosteogenesis is borne out by in vivo (technetium 99, methylene diphosphonate scanning) and histopathological (tetracycline fluorescence and polarizing microscopy) studies. This early work in the canine suggests the potential for application in the human when the procedure is further refined and perfected.

Animals↗

PubMed1998

Dentin demineralization inhibition at restoration margins of Vitremer, Dyract and Compoglass.

PURPOSE: To examine the in vitro caries inhibition of a resin-modified glass ionomer cement (Vitremer-3M) and two compomers (Dyract-Dentsply; Compoglass-Ivoclar). MATERIALS AND METHODS: Standardized Class V preparations were placed in 40 molars, the gingival margin placed below the cementoenamel junction. Randomly, 10 Vitremer, 10 Dyract and 10 Compoglass restorations were placed according to manufacturer's instructions, in 30 teeth. Ten teeth received P-50 composite resin (3M) restorations and acted as the control. All teeth had an acid-resistant varnish placed to within 1 mm of restoration margins and they were then placed into artificial saliva for 4 weeks, the saliva being replenished every 48 hours. All teeth were subjected to an artificial caries challenge (pH 4.4) for 5 days. Sections of 100 microns were obtained, photographed under polarized light microscopy, and then digitized to quantitate demineralized areas adjacent to the restoration. RESULTS: The mean (+/- S.D) area (microns 2) demineralization 100 microns from the dentin/gingival margin was: Vitremer 4965 +/- 841, Compoglass 4981 +/- 2209, Dyract 5375 +/- 516, P-50 8088 +/- 2083. ANOVA and Duncan's (P < 0.05) indicated all three fluoride-releasing materials examined in this study had significantly less demineralization adjacent to restoration margins than the P-50 composite resin control. Seventy percent of glass ionomer cement restorations demonstrated adjacent dentin inhibition zones, while no dentin inhibition zones were demonstrated with the compomer restorations.

Analysis of Variance↗

PubMedDate not supplied

Dental histology: study of aging processes in root dentine.

The amount of sclerotic root dentine increases with age, proceeding from the apex towards the crown. There are obvious optical changes in the tissue, which becomes translucent (dentine is normally opaque). Therefore, the sclerosis of root dentine could be a reliable indicator of age in anthropological studies of human remains. We studied the histological aspects of sclerotic dentine in longitudinal thin sections (70-140 microns) of undecalcified premolars, cut in the bucco-lingual plane. To quantify the sclerosis and to construct a reference standard, we sectioned 85 premolars from subjects of known age (70 from odontological extractions and 15 from a university collection). Another 10 teeth from medieval subjects were studied to assess the applicability of the method to ancient skeletal collections. The technique consists of embedding the tooth in a polyester resin (cold method), sectioning it with a diamond blade microtome. Qualitative analysis was performed with polarized light microscopy and measurements were made with a quote 2D x,y viewer and on digital images. The sclerotic root dentine was quantified with both linear and surface area parameters in order to assess the correlation with age. The quality of the sections was sufficient for the clear discernment and quantification of the sclerotic dentine. Indeed, the technique allowed us to obtain good results with a considerable saving of time and money compared with other dental histological techniques. The best correlation with age was obtained from the surface area parameter, particularly after exclusion of the cementum and pulp chamber. To produce comparable data from similar studies, we advise the use of cold resins, as used here, and digital computerized analyzers because of their accuracy, precision and quickness. The qualitative analysis of the ancient teeth indications that this dental aging techniques can be applied to both recent and ancient dental tissues.

Adolescent↗

PubMed2000

Role of lipids in molecular thermoadaptation mechanisms of seagrass Zostera marina.

By using the combined approaches of microcalorimetric analysis and polarizing microscopy, the crystal-liquid crystal-isotropic melt phase transition of major phospholipids (phosphatidylcholine and phosphatidylethanolamine) and glycolipids (monogalactosyldiacylglycerol and digalactosyldiacylglycerol) isolated from marine seagrass Zostera marina were investigated. Here we discuss the results in view of the fatty acid structures of the lipids studied.

Acclimatization↗

PubMed2000

Thermotropic behaviour of membrane lipids from brown marine alga Laminaria japonica.

Microcalorimetry was used to show that transition-temperature ranges of phospho- and glycolipids of the brown marine alga Laminaria japonica were similar (from -62 to -47 degrees C up to 62-65 degrees C), except for monogalactosyldiacylglycerol, the low-temperature limit of which was shifted to -78 degrees C. As was shown by polarizing microscopy, the low-enthalpy peaks at temperatures of approx. 30-45 degrees C corresponded to isotropic melting of galactolipids and coincided with the high-temperature limit for photosynthetic and mitochondrial activity of the algae. As a whole, a classical interrelation was observed between thermotropic behaviour and the fatty acid unsaturation of lipids.

Acclimatization↗

PubMedDate not supplied

Argon laser curing of fluoride-releasing pit and fissure sealant: in vitro caries development.

The purpose of this study was to compare the effect of argon laser polymerization of a visible-light-cured, fluoride-releasing pit and fissure sealant on caries development in vitro. A total of twelve caries-free premolar and molar teeth was selected, and underwent a fluoride-free prophylaxis and soft tissue debridement. Cavity preparations were placed in buccal and lingual surfaces. Lingual cavity preparations were filled with the fluoride-releasing sealant (UltraSealXTplus, Ultradent) and visible light cured per the manufacturer's recommendation. Buccal preparations were filled with the fluoride-releasing sealant and argon laser cured (231 mW, 12 J/cm2 for 10 seconds). Following sealant placement, the teeth were sectioned into buccal and lingual halves. An acid-resistant varnish was placed leaving a 1 mm rim of exposed surface enamel adjacent to the sealant. The specimens were then thermocycled in synthetic saliva (500 cycles, 5 to 50 degrees C). In vitro caries lesions were formed (2.2 mM Ca, 2.2 mM PO4, 50 mM acetic acid, 5 ppm fluoride, pH 3.95). Longitudinal sections (five sections per tooth half) were obtained and evaluated by polarized light microscopy for mean outer surface lesion depths and frequency of wall lesions. Mean primary surface (outer) lesion depth was significantly decreased (ANOVA, DMR, P < .05) for the fluoride-releasing sealant with argon laser polymerization (152 +/- 16 um) when compared with visible light curing (211 +/- 23 um). Likewise, wall lesion frequency was substantially reduced for the argon laser polymerized sealants (17 percent) when compared with that for the visible light polymerized sealants (24 percent, ANOVA, DMR, P < .05). Argon laser polymerization of a fluoride-releasing pit and fissure sealant improved caries resistance markedly in the surface enamel adjacent to the sealant material. Argon laser curing enhanced the caries protective ability of the sealant along the enamel-resin cavosurface, as noted by a decrease in wall lesion frequency. Argon laser polymerization provides further caries protection against a cariogenic challenge over that afforded by fluoride-releasing sealants. Caries development around a sealant material may be hampered by the combination of fluoride release from the sealant and argon laser polymerization.

Acetates↗

PubMed1998

[Morphological studies of myocardial fibrosis in different types of Keshan disease].

OBJECTIVE: To clarify the localization, distribution, content and type of collagen in the myocardium of patients with Keshan disease (KD). METHODS: Picrosirium red staining, polarization microscopy and image analysis were used to study autopsy specimens from 335 KD patients. RESULTS: A loose network of collagen and a higher ratio of type III collagen were found in the myocardial scar tissues of acute KD patients. In the myocardial scar tissues from chronic KD patients, the collagen fibers were dense, the ratio of type I collagen was higher, the ratio of type I to type III is increased in chronic KD and decreased in acute KD. The amount of collagen in non-necrotic regions was significantly higher than that of the controls. CONCLUSION: The degeneration and necrosis of myocytes in KD is associated with disorders of collagen metabolism and with structural modelling of collagen.

Cardiomyopathies↗

PubMed2000

Fluoride-releasing sealant and caries-like enamel lesion formation in vitro.

OBJECTIVE: The aim of this laboratory study was to evaluate the effects of a fluoride-releasing pit and fissure sealant (FS) and a conventional non-fluoride-containing pit and fissure sealant (CS) on caries-like lesion formation in enamel. DESIGN: Twelve extracted, macroscopically caries-free human molar teeth underwent fluoride-free prophylaxis and were sectioned into toothquarters. Cavity preparations were placed in buccal and lingual surfaces of the toothquarters, acid-etched and filled with sealant material (per the manufacturer's instructions) as follows: 1) mesiobuccal and mesiolingual quarters--FS (Fissurit-F, VocoChemie); and 2) distobuccal and distolingual quarters--CS (Fissurit, VocoChemie). Prior to caries formation in an acidified gel, the toothquarters were thermocycled (500 cycles) in artificial saliva. Sections were taken following caries initiation (6 week gel exposure) and caries progression (9 week gel exposure), and examined by polarized light microscopy to determine mean primary surface lesion depth and presence or absence of wall lesions. RESULTS: Mean surface lesion depths were significantly different between FS and CS groups following caries initiation (FS = 119 microns; CS = 157 microns, p < 0.05, paired t-test) and progression (FS = 169 microns; CS = 221 microns, p < 0.05, paired t-test). Wall lesions were reduced in FS (14% initiation; 25% progression) when compared with CS (19% initiation; 35% progression); however, this was not significantly different (p > 0.05, paired t-test). CONCLUSION: A pit and fissure sealant containing releasable fluoride provided a caries inhibiting effect with a significant reduction in lesion depth in the surface enamel adjacent to the fluoride-releasing sealant and a tendency toward reduction in the frequency of wall lesions. CLINICAL SIGNIFICANCE: Fluoride release by pit and fissure sealants may provide additional protection against caries formation in cuspal incline enamel and smooth surfaces adjacent to sealed pits and fissures, and act as a fluoride reservoir with long-term release of fluoride into the immediately adjacent oral environment.

Acid Etching, Dental↗