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PubMed2003

O/w dispersions development containing liquid crystals.

Liquid crystals are defined as the intermediary state between solid and liquid and also called of mesomorphous phase or crystalline phase, presenting characteristics of the mentioned physical states. For the simple emulsions that intermediary phase can act as forms of encapsulation of drugs providing its controlled liberation and besides, it can increase cutaneous hydration. These characteristics evidences the differentiation of the developed formulations and the use of the same ones in the release of new cosmetic vehicles. In that research we use vegetable oils (coffee, tomato), mineral oil, surfactants like phosphorics esthers (fractions A and B) and distilled water as aqueous phase. The stable formulations were submitted to stability physic-chemical preliminary tests (pH values determination, electric conductivity values, centrifugation and thermal stress) and later the compositions were submitted to accelerated stability tests (cold-hot cycle in the following temperature conditions--4 +/- 2 degrees C, 25 +/- 2 degrees C and 45 +/- 2 degrees C). Crystalline phase was identified by microscopy polarization. The recently prepared formulations and aged formulations (after 30 days) were appraised for rheology.

Cosmetics↗
PubMed2003

Enamel demineralization inhibition by cements at orthodontic band margins.

PURPOSE: To examine the demineralization inhibition effects of glass ionomer cement and polyacid-modified resin-based composite cement, in comparison to non-fluoride releasing zinc phosphate cement. METHODS: Twenty-seven extracted molars were obtained and randomly assigned to three groups. An orthodontic band was sized and cemented using one of three cements. The teeth were painted with an acid-protective varnish, excluding a 1 mm area gingival to the orthodontic band. The teeth were placed in separate closed environments of a non-fluoridated acid challenge to induce demineralization for 5 days. The teeth were then sectioned two times buccolingually and two times mesiodistally. The sections were photographed with polarized light microscopy in an imbition media of water. The body of each lesion was measured with a computerized imaging system. The areas of the lesions, from each cement group, were compared. RESULTS: An analysis of variance (ANOVA) indicated significance in variance among groups (P < 0.001). Results of a multiple comparison analysis demonstrated significantly less demineralization adjacent to the glass ionomer cement group compared with the polyacid-modified resin cement group and non-fluoride releasing zinc phosphate control group (P < 0.05). There was no significant difference in adjacent demineralization inhibition between the zinc phosphate cement group and polyacid-modified resin cement group (P < 0.05).

Analysis of Variance↗
PubMed1992

Semi-quantitative X-ray microanalysis of bronchoalveolar lavage samples from silica-exposed and nonexposed subjects.

To evaluate the possibility of quantifying alveolar dust burden in conditions of exposure to silica, four groups of subjects were submitted to bronchoalveolar lavage (BAL): 10 healthy control subjects and 39 patients affected by diffuse interstitial lung disease (DILD) never exposed to dust, 23 silicotic patients and 12 chronic bronchitis patients with a history of occupational exposure to silica dust. Five to ten million BAL recovered cells were analysed with an energy-dispersive X-ray microanalysis (EDXA) system to determine the silicon content, expressed in a semi-quantitative way as silicon to sulphur (Si/S) ratio. The results were independent of smoking habit. The Si/S median values (interquartile range in brackets) for the four groups were 0.53 (0.5-0.65), 0.60 (0.41-0.8), 1.23 (1.06-1.39), 1.31 (1.11-1.97), respectively. Silicotics and simply exposed individuals did not show a significant discrepancy, but they were both significantly different in comparison with normal and DILD patients without history of exposure (p less than 0.001). 14.3% false negative cases were found, and 4.1% false positive cases (none among normal subjects). We did not see any significant relationships between the amount of silicon and the duration of exposure or the degree of chest X-ray involvement. A study of cytocentrifuge slides from the same subjects by polarizing light microscopy revealed a lower sensitivity (34% false negative cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchitis↗
PubMed2004

Dr. Walter C. McCrone's contribution to the characterization and identification of explosives.

Dr. McCrone was an amazing individual, possessing many talents and having many interests. He especially loved applying polarized light microscopy (PLM) to answering the question-at-hand and solving problems. He applied PLM to many different fields including the identification of air pollution particles, asbestos identification, art conservation, pharmaceuticals, industry problems and forensic sciences. A field that I believe he enjoyed the most was the characterization and identification of explosives. Throughout his life he worked on, gave presentations and published articles on the characterization and identification of explosives. Also, he encouraged other scientists to give presentations and publish on the subject by providing "behind the scene" advice and/or be a co-author on a paper. He unselfishly taught others how to apply PLM and incorporate this invaluable tool into their analytical scheme.

Explosions↗
PubMed1992

The extracellular matrix in slow-growing tumors of the central nervous system.

This report describes and illustrates the results of the histopathological and histochemical investigation on five slow-growing tumors of the central nervous system: four meningiomas and an ependymoma of the spinal cord. We have studied, by means of polarizing microscopy, sections stained with picro-sirius red F3BA that enhance the birefringence of collagen and reticulum fibres. The heterogeneous behaviour of the distribution of the collagen let us conclude that the fibrillar component of the extracellular matrix have a scarce importance for the speed of growth of these tumours.

Cell Division↗
PubMed2004

Effect of naproxen on tail fin regeneration in teleost.

In the present investigation we studied the effect of naproxen, a non-steroidal anti-inflammatory drug used for the treatment of rheumatic disease, on the synthesis of the lepidotrichial matrix of the tail fin of the teleost fish Cyprinus carpio (carp) during the regeneration process. The lepidotrichial synthesis was observed by standard and polarized light microscopy and by transmission electron microscopy. In general, naproxen at the dose used in the present study did not affect the organization of the extracellular matrix components and the mineralization of the fundamental substance of the lepidotrichia during the process of tail fin regeneration. Since the effect of naproxen, as well as of other non-steroidal anti-inflammatory drugs, depends on the dose used, the route of administration and the metabolism of the animal in which the drug is being tested, higher doses of the drug may perhaps delay or even fully inhibit this process, possibly also provoke disorganization of the lepidotrichial matrix.

Animals↗
PubMed1992

Metallic debris in femoral endosteolysis in failed cemented total hip arthroplasties.

A prospective study was undertaken to quantitate metallic and cement debris in 12 consecutive patients with femoral endosteolysis (FE) and aseptic loosening of a cemented total hip arthroplasty. The mean interval between primary and revision surgery was 9.6 years. The average time to onset of FE was 8.9 years. There were four stems each of cobalt-chromium (Co-Cr), stainless steel (SS), and titanium alloy. At revision, tissue was retrieved from FE, the femoral bone-cement pseudomembrane, and the joint pseudocapsule. Histology of these tissues was studied using light and polarized microscopy. Metal and barium levels were measured by atomic absorption spectrophotometry. A histiocytic reaction and particulate cement debris were seen in every case. Polyethylene wear debris was noted in 11 of 12 cases (92%), and metallic debris in four cases (33%). Detectable metal levels were found in the FE in all cases. Metal levels were on average 2.5 times higher in FE than in femoral pseudomembrane, and 4.2 times higher than in joint pseudocapsule. This difference was statistically significant for the Co-Cr and SS groups. Barium levels in areas of FE were on average 1.7 times and 42.4 times higher than in femoral pseudomembrane and joint pseudocapsule, respectively. The difference seen between the FE and the joint pseudocapsule tissue was significant for all three alloy groups. The authors' data demonstrated higher metal and barium levels in FE than in the other tissue sites. Polyethylene and cement debris were noted in nearly every case. Cement, polyethylene, and metallic particulate wear debris may contribute to the pathogenesis and progression of FE.

Adult↗
PubMed2004

Remineralization effects of a sodium fluoride bioerodible gel.

PURPOSE: To evaluate the effectiveness of a 5% sodium fluoride (NaF) bioerodible gel to remineralize demineralized enamel. METHODS: Artificial enamel lesions were created at the gingivofacial surface of 36 extracted teeth. Longitudinal sections were obtained through the lesions, photographed under polarized light microscopy, and the demineralized areas were quantitated. Sections were painted with an acid-protective varnish, leaving only the facial surface of the enamel lesion exposed, and positioned naturally into the tooth from which they were obtained. Teeth were randomly mounted in sets of four that simulated a natural anterior arch form. Equal numbers were subjected to a NaF gel, control gel dr received no treatment, with the gel being placed and retained by the interproximal embrasures of the teeth. Following 30 days exposure to artificial saliva, the lesions were photographed and quantitated in the same manner as prior to treatment. RESULTS: The NaF gel showed significantly more remineralization than the control groups (P< 0.05), with a 68.9% (+/- 17.7) mean lesion remineralization.

Analysis of Variance↗
PubMed2004

Common aspects of human and primate seronegative arthritis.

A 27-year-old female lowland gorilla developed an asymmetric oligoarthritis 3 months post-partum. There was no evidence of an antecedent gastrointestinal or genitourinary infection. Serum was negative for rheumatoid factor and antinuclear antibody. Synovial fluid revealed 2000 white blood cells with negative cultures and polarized microscopy. Studies on synoviocytes were the following: (1) FACS analysis revealed surface expression of a B27-like epitope of the cells. (2) Analysis of intracellular clearance kinetics of arthritogenic organisms showed peak intracellular colony-forming units at 48 hours after bacterial invasion, and clearance by 13 days post-invasion. (3) Interferon-y (0.1-10.0 ng/ml)accelerated intracellular microbicidal pathways in a dose-dependent fashion. These findings closely parallel those seen in human synoviocytes of patients with spondyloarthropathy. Primate and human seronegative arthritis share clinical and immunologic features, as well as aspects of host:pathogen defense mechanisms. The interplay of genetic and microbial factors underlying this arthritis appears to be conserved across these species boundaries.

Animals↗
PubMed2004

Macromolecular array patterns of silk gland secretion in social Hymenoptera larvae.

The cocoon, produced by most holometabolous insects, is built with silk that is usually produced by the larval salivary gland. Although this silk has been widely studied in the Lepidoptera, its composition and macromolecular arrangement remains unknown in the Hymenoptera. The macromolecular array patterns of the silk in the larval salivary gland of some meliponids, wasps, and ants were analyzed with polarized-light microscopy, and they were compared with those of Bombyx mori (Lepidoptera). There is a birefringent secretion in the glandular lumen of all larvae, due to filamentous structural proteins that display anisotropy. The silk in the distal, middle and proximal regions of the secretory portion of Formicidae and Vespidae glands presented a lattice optical pattern. We found a different pattern in the middle secretory portion of the Meliponini, with a zigzag rather than a lattice pattern. This indicates that the biopolymer fibers begin their macromolecular reorganization at this glandular region, different from the Formicidae and the Vespidae, in which the zigzag optical pattern was only found at the lateral duct. Probably, the mechanism of silk production in the Hymenoptera is a characteristic inherited from a common ancestor of Vespoidea and Sphecoidea; the alterations in the pattern observed in the Meliponini could be a derived characteristic in the Hymenoptera. We found no similarity in the macromolecular reorganization patterns of the silk between the Hymenoptera species and the silkworm.

Animals↗
PubMed2005

[Study of the expression of heat shock protein 47 and its correlation to collagen].

OBJECTIVE: To study the expression of heat shock protein 47 (HSP47) and its correlation to collagen deposition in pathological scar tissues. METHODS: The tissues of normal skin (10 cases), hypertrophic scar (19 cases), and keloid (16 cases) were obtained. The expression of HSP47 was detected by immunohistochemistry method. The collagen fiber content was detected by Sirius red staining and polarization microscopy method. RESULTS: Compared with normal skin tissues (Mean IOD 13 050.17 +/- 4 789.41), the expression of HSP47 in hypertrophic scar (Mean IOD 521 159.50 +/- 272 994.13) and keloid tissues (Mean IOD 407 440.30 +/- 295 780.63) was significantly high (P < 0.01). And there was a direct correlation between the expression of HSP47 and the total collagen fiber content (r = 0.386, P < 0. 05). CONCLUSION: The HSP47 is highly expressed in pathological scar tissues and it may play an important role in the collagen deposition of pathological scar tissues.

Adolescent↗
PubMed2004

In vitro enamel caries formation: argon laser, light-emitting diode and APF treatment effect.

PURPOSE: To evaluate argon laser irradiation (AL), light-emitting diode exposure (LED), and acidulated phosphate fluoride treatment (APF) in vitro effects on caries-like enamel caries formation. METHODS: Sound teeth (n = 18) were divided into four tooth quarters and coated with an acid-resistant varnish, leaving an enamel window exposed per tooth quarter. The tooth quarters were assigned to: (1) no treatment (control, mesiobuccal); (2) 1.23% APF (4 minutes, distolingual); (3) LED (Ultradent Ultra-Lume LED2 20 seconds, mesiolingual); and (4) AL (HGM Model 8, 11.5 J/cm2, 231 mW, 5mm beam size, 10 seconds, distobuccal). Following caries-like lesion formation (modified ten Cate solution), longitudinal sections (three per tooth quarter, 54 lesions per group) were obtained and evaluated for mean lesion depths (water imbibition, polarized light microscopy, ANOVA, DMR). RESULTS: Mean lesion depths were: 198 +/- 21 microm for controls; 186 +/- 17 microm for LED; 117 +/- 19 microm for AL; and 104 +/- 23 microm for APF. Lesion depths were statistically significantly decreased for AL (41%) and APF (47%) groups (P < 0.05), compared with controls. A slight lesion depth reduction for LED (6%) was present compared with controls; however this was not statistically significantly different (P > 0.05).

Acidulated Phosphate Fluoride↗
PubMed2004

Potential remineralization of demineralized enamel after application of fluoride varnish.

PURPOSE: To evaluate remineralization effects of a topical fluoride varnish applied over a caries-like lesion compared to around a caries-like lesion. METHODS: Caries-like lesions were created on 30 molar surfaces. Sections were cut through each lesion, photographed under polarized light microscopy, and quantitated with a computerized imaging system. The sections were repositioned with only the lesion exposed. Half were painted with a 5% NaF varnish, including the surface of lesion. The remaining half were painted excluding the surface of the lesion. The sections were placed in artificial saliva for 30 days, re-photographed and re-quantitated. RESULTS: Using a student t-test for analysis, the results demonstrated the mean (+/- S.E.) percent remineralization of lesion size to be 10.8 (4.8) for lesions completely covered by the fluoridated varnish and 9.5 (2.9) for lesions that had the fluoridated varnish surrounding the lesion. Both application techniques indicated remineralization effects, yet there was no significant difference between the two application techniques evaluated in this study (P < 0.05). The data from this in vitro study indicated that there was no significant difference in methods of application for fluoridated varnish. Both application techniques demonstrated effective remineralization.

Cariostatic Agents↗
PubMed2004

[Spectroscopic studies on transition metal ions in colored diamonds].

Transition metals like nickel, cobalt and iron have been often used as solvent catalysts in high pressure high temperature (HPHT) synthesis of diamond, and nickel and cobalt ions have been found in diamond lattice. Available studies indicated that nickel and cobalt ions could enter the lattice as interstitial or substitutional impurities and form complexes with nitrogen. Polarized microscopy, SEM-EDS, EPR, PL and FTIR have been used in this study to investigate six fancy color natural and synthetic diamonds in order to determine the spectroscopic characteristics and the existing forms of transition metal ions in colored diamond lattice. Cobalt-related optical centers were first found in natural chameleon diamonds, and some new nickel and cobalt-related optical and EPR centers have also been detected in these diamond samples.

English Abstract↗
PubMed2005

The in vitro performance of laser fluorescence and caries-detector dye for detecting residual carious dentin during tooth preparation.

OBJECTIVE: The aim of this in vitro study was to compare the performance of a laser fluorescence device (DIAGNOdent) and a caries-detector dye for detecting residual dentinal caries. METHODS AND MATERIALS: Forty extracted human molar teeth with deep dentinal carious lesions on their approximal surfaces were used for the study. The caries were removed by a new chemomechanical system, Carisolv. Three independent observers checked all cavities for residual caries using caries-detector dye and DIAGNOdent. The presence or absence of residual caries was verified using polarized light microscopy as the gold standard. Three observers recorded two different measurements at the same site after 2 weeks to determine intra- and interexaminer reproducibility of the DIAGNOdent. RESULTS: Average kappa values of 0.61 for interexaminer reproducibility and 0.94 for intraexaminer reproducibility were determined. The specificity of caries-detector dye was found to be 100% and the specificity of the DIAGNOdent was 86%. CONCLUSION: Although DIAGNOdent showed greater sensitivity than caries-detector dye (P < .05), low sensitivity values for each diagnostic system may lead to teeth with residual caries being undetected. Therefore, it might be advisable to reconsider the criteria for detecting residual caries during tooth preparation.

Coloring Agents↗
PubMedDate not supplied

Disseminated superficial porokeratosis with amyloid deposits.

We report a 65-year-old Caucasian man who exhibited a disseminated superficial porokeratosis. Histological examination with haematoxylin and eosin stain revealed the presence of dermal deposits of an eosinophilic amorphous material that stained positively with crystal violet and showed bright yellow fluorescence with thioflavin-T under the polarizing microscopy, indicating that it was amyloid. Colloid bodies from porokeratotic lesions can degenerate into amyloid, but it is not usually detected with haematoxylin and eosin stains because of its small quantity. Probably amyloid deposits could be detected more frequently in porokeratosis if histochemical techniques were carried out in a routine way.

Aged↗
PubMed2005

[Study of crystalluria in diabetic patients].

INTRODUCTION: The incidence of diabetes, particularly non-insulin-dependent diabetes, is on the increase in industrialized and developing countries. The prevalence of renal stones in the diabetic population was recently estimated to be 21%, i.e. more than twice the prevalence of stones in the general population. Other studies have emphasized the high frequency of uric acid stones in this particular population. The present study was designed to verify whether diabetic patients present a particular type of crystalluria predisposing them to a high frequency of uric acid stones than other types of stones, which could allow detection of this risk and the proposal of therapeutic measures to prevent these stones. MATERIAL AND METHOD: The first morning urine of 208 diabetic patients was examined by polarized light microscopy to detect and identify crystalluria. Patients were distributed into 3 age-groups: less than 40 years, 40 to 59.9 years and 60 years or more. The results are expressed as the predominant crystalline species. RESULTS: The overall frequency of crystalluria was 29.8%, i.e. about one half that observed in calcium stones. However, the crystallogenic profile was very unusual, as 61.3% of cases of crystalluria consisted of purine. Uric acid crystalluria was twice as frequent in women than in men (66% vs 33.3%, p < 0.05). The mean pH of the urine of diabetic subjects was 5.5, i.e. significantly more acidic than that of normal subjects or patients with calcium stones. pH was negatively correlated with the patient's age, decreasing from 5.54 in patients younger than 40 to 5.3 in patients over the age of 60 (p < 0.05). The mean pH of crystalluric urine was significantly more acidic than that of crystal-free urine (pH 5.2 +/- 0.46 vs 5.5 +/- 0.67, p < 0.01). CONCLUSION: Diabetic patients have an acidic urinary pH which tends to decrease with age, predisposing to uric acid crystalluria, which is particularly frequent in women. The high prevalence of uric acid crystalluria and the high proportion of uric acid stones reported in diabetic women suggest that women are at greater risk than men of developing uric acid stones in the context of diabetes. The study of crystalluria could be useful to detect this risk and to propose preventive measures. Complementary studies are necessary to identify factors accounting for the increased risk of uric acid stones in diabetic women and to verify whether good glycaemic control can reduce the crystallogenic risk.

Adult↗