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PubMed1993

Silicone shedding from artificial urinary sphincter in children.

Silicone is an inert material used in all genitourinary prosthetic devices. Silicone particle shedding has been documented in adults with penile prostheses and artificial urinary sphincters. We searched prospectively for silicone particles in the peri-prosthetic tissue and regional lymph nodes in 6 children who underwent removal or exchange of an artificial urinary sphincter. The peri-prosthetic fibrous capsule was biopsied and examined by light and polarizing microscopy. Regional lymph nodes were biopsied if clinically enlarged and evaluated in a similar manner. Lymph nodes from 2 children without an artificial urinary sphincter served as controls. An artificial urinary sphincter was in place from 3 to 10 years (mean 4.3 years) and none of the sphincters demonstrated infection or erosion. Silicone particles were found in the peri-sphincteric tissue of 3 patients, which induced foreign body giant cell reaction in 2 and eosinophilic infiltrate in 1. Focal histiocytic proliferation around the cuff was seen in another case without silicone migration. There was fibrosis around the sphincter in all cases. No silicone was found in the regional lymph nodes. Silicone shedding was documented in 50% of our patients. X-ray energy dispersive spectroscopy was not performed, raising the possibility that it was under-detected. Long-term effects of silicone in children with an artificial urinary sphincter are unknown and warrant further study.

Child↗
PubMed1998

Morphological and electrical characteristics of postnatal hippocampal neurons in culture: the presence of bicuculline- and strychnine-sensitive IPSPs.

A modified method was developed for tissue-culturing postnatal hippocampal neurons using simple mechanical trituration for cell isolation and not including any hydrolysing enzymes, nerve growth factors or antiproliferating agents. The morphological properties of such neurons were characterized with light and interference polarizing microscopy, which revealed the appearance of growth cones from peripheral neurons and the presence of different types of neurons, including bipolar, stellate and pyramidal-like cells (i.e., pyramidal and dentate gyrus granule cells), which could be related to their putative counterparts in intact brain. The whole-cell configuration of the patch-clamp method was used for electrophysiological recordings of inhibitory synapses between these dissociated cultured neurons from the early postnatal rat hippocampus. This study indicated the presence of tetrodotoxin (TTX)-sensitive and TTX-resistant inhibitory postsynaptic potential (IPSPs) and inhibitory postsynaptic currents (IPSCs) in current-clamp and voltage clamp modes respectively. The coincident reversal potentials for IPSCs and for GABAA and glycine-evoked currents, and the sensitivity of the IPSCs to bicuculline or strychnine, indicated that these IPSCs were Cl-(-)dependent and mediated by either GABAA or glycine receptors. Inhibitory postsynaptic currents recorded under voltage-clamp conditions decayed with a time course that could be fitted by a single exponential with a value of 26 ms. An average quantal content of 2.5 was responsible for a typical GABA and glycine-activated IPSC and a single quantum for GABAergic input was inferred to activate about 160, and for glycinergic, about 200 Cl-, channels.

Action Potentials↗
PubMed1989

Immunohistochemical characterization of spontaneous amyloidosis in captive birds as AA-type, using monoclonal and polyclonal anti-AA antibodies against mammalian amyloid.

Spontaneous amyloid diagnosed by means of Congo red and polarization microscopy in 3 flamingos, 1 crowned crane, 1 red-breasted goose, and 1 common golden-eye was studied using immunohistochemical techniques. The avian amyloid cross-reacted with a number of monoclonal and polyclonal anti-AA antibodies directed against mammalian amyloid fibril proteins. This confirmed that both "secondary" and "idiopathic" avian amyloid is of the AA-type. The results demonstrate the possibility to successfully using cross-reactive anti-AA antibodies for the diagnosis of non-mammalian amyloidosis.

Amyloidosis↗
PubMed1999

Microscopic and histochemical manifestations of hyaline cartilage dynamics.

Structure and function of hyaline cartilages has been the focus of many correlative studies for over a hundred years. Much of what is known regarding dynamics and function of cartilage constituents has been derived or inferred from biochemical and electron microscopic investigations. Here we show that in conjunction with ultrastructural, and high-magnification transmission light and polarization microscopy, the well-developed histochemical methods are indispensable for the analysis of cartilage dynamics. Microscopically demonstrable aspects of cartilage dynamics include, but are not limited to, formation of the intracellular liquid crystals, phase transitions of the extracellular matrix and tubular connections between chondrocytes. The role of the interchondrocytic liquid crystals is considered in terms of the tensegrity hypothesis and non-apoptotic cell death. Phase transitions of the extracellular matrix are discussed in terms of self-alignment of chondrons, matrix guidance pathways and cartilage growth in the absence of mitosis. The possible role of nonenzymatic glycation reactions in cartilage dynamics is also reviewed.

Animals↗
PubMed1989

Cellulose fibers from endodontic paper points as an etiological factor in postendodontic periapical granulomas and cysts.

Histological sections of eight periapical granulomas and cysts developing after conventional endodontic therapy and displaying faintly hematoxylinophilic, birefringent foreign bodies were investigated by light and polarization microscopy, scanning electron microscopy, energy-dispersive X-ray, and chemical analysis. In addition to a variably dense mononuclear infiltrate, the granulomas and cysts revealed varying amounts of giant cells associated with the birefringent foreign bodies. These structures were identified as cellulose fibers, most probably originating from endodontic paper points, which in our opinion can be held responsible for the initiation and perpetuation of chronic postendodontic periapical lesions.

Cysts↗
PubMed1994

The effect of bile acid hydrophobicity on nucleation of several types of cholesterol crystals from model bile vesicles.

Nucleation of cholesterol crystals is thought to occur from cholesterol-phospholipid vesicles. We tested the hypothesis that bile acids are necessary for nucleation of cholesterol crystals. Model bile vesicles were prepared by KBr density ultracentrifugation of supersaturated model bile and mixed with one of the following bile acids: ursodeoxycholate, taurocholate, cholate, chenodeoxycholate or deoxycholate in final concentrations of 3, 30 and 100 mM. Vesicles were also mixed with various combinations of ursodeoxycholate and deoxycholate. Nucleation was assessed semi-quantitatively with polarizing microscopy. After 5 days, samples were again subjected to ultracentrifugation. Addition of 3 and 30 mM taurocholate, cholate, chenodeoxycholate and deoxycholate to vesicles induced nucleation. The extent of nucleation increased significantly with increasing bile acid hydrophobicity: deoxycholate > chenodeoxycholate > cholate > taurocholate (p < 0.05). At 100 mM bile acid this order was reversed (p < 0.05) because most of the cholesterol was solubilized in micelles as shown by ultracentrifugation after 5 days. Percentages of vesicular cholesterol decreased with increasing hydrophobicity: deoxycholate < chenodeoxycholate < cholate < taurocholate (p < 0.05). Ursodeoxycholate did not induce nucleation. At least seven cholesterol crystal shapes could be distinguished and all crystal types could be found after addition of various combinations of ursodeoxycholate+deoxycholate. We conclude that in this model: (a) bile acid species play an important role in the precipitation of cholesterol crystals from model bile vesicles; (b) the more hydrophobic bile acids induce more cholesterol crystal precipitation; and (c) the hydrophobicity of bile acids influences cholesterol crystal morphology.

Bile↗
PubMed1998

Effects of serpins on cholesterol crystallization in model bile.

BACKGROUND/AIMS: The serine proteinase inhibitors (serpins), alpha-1-antitrypsin (AAT) and alpha-1-antichymotrypsin (ACT), are acute phase proteins synthesized by hepatocytes and excreted to some extent into bile. Their role in gallstone pathogenesis is unclear, and it was the aim of this study to determine their effect on cholesterol crystal growth rate in model bile. METHODS: Purified AAT and ACT were added to model bile at concentrations from 0.5 to 500 microg/ml. Cholesterol crystal growth was analyzed daily by polarizing microscopy and spectrophotometrically at 650 nm. Serpin inhibitory activity was measured spectrophotometrically at 405 nm, and polymerization was studied on 7.5% SDS-PAGE under non-reducing conditions, by immunoelectrophoresis and Western blotting. RESULTS: ACT added to model bile at a concentration of 0.5 microg/ml, inhibited cholesterol crystallization by 30%, had no influence at 5 microg/ml, and increased the crystallization rate 2-3 fold at concentrations of 50 and 500 microg/ml. AAT at a concentration of 0.5 microg/ml had a profound (50%) inhibitory effect on cholesterol crystal growth rate, lacked significant effect at both concentrations of 5 and 50 microg/ml, and showed stimulation of crystal growth up to 30% at a concentration of 500 microg/ml. Both serpins incubated in model bile polymerized and totally lost their inhibitory activity. CONCLUSIONS: Serpins can exhibit both inhibiting and promoting effects on the cholesterol crystallization rate in model bile, dependent on their concentrations. Since AAT and ACT are acute phase proteins, their concentrations may vary under certain pathological conditions, which may result in different actions of these serpins in gallstone formation.

Bile↗
PubMed1980

Lamellar ichthyosis, dwarfism, mental retardation, and hair shaft abnormalities. A link between the ichthyosis-associated and BIDS syndromes.

There is an expanding list of syndromes that combine ichthyosis with neuroectodermal and mesodermal defects. We present the case of a young woman with the following features: lamellar ichthyosis, dwarfism, mental retardation, nail and dental abnormalities, unusual facies, poor sexual maturation, punctate cataracts, and hair shaft abnormalities. There were no neurologic or auditory defects. Hair examination revealed pili torti, trichoschisis, bright and dark bands with polarizing microscopy, and a low hair sulfur content. The patient did not have aminoaciduria or immunoglobulin abnormalities. We believe that this case is a link between the ichthyosis-associated syndromes and the group of syndromes that have in common abnormal hair with clean transverse fractures (trichoschisis) and low sulfur content. A more complete examination of the hair in other patients with ichthyosis and associated abnormalities will probably reveal more patients with this new syndrome.

Adult↗
PubMed1984

Low-sulfur hair syndrome associated with UVB photosensitivity and testicular failure.

A 16-year-old male patient had a syndrome that included growth retardation, mental retardation, hair shaft abnormalities, neurosensory hearing loss, contractures of the fifth fingers, ultraviolet B (UVB) photosensitivity, small testicular size, and elevated levels of follicle-stimulating hormone. Reduced hair sulfur content and a characteristic pattern of light and dark birefringent bands, seen when hairs were viewed with polarization microscopy, were typical of the low-sulfur hair syndrome. UVB photosensitivity and testicular failure have not previously been identified as components of this syndrome.

Adolescent↗
PubMed1986

Carpal tunnel syndrome with cystic bone lesions secondary to amyloidosis in chronic hemodialysis patients.

Carpal tunnel syndrome (CTS) is increasingly recognized in patients undergoing chronic hemodialysis. Although the etiology remains obscure, angioaccess-related vascular engorgement and edema, and ischemic neuropathy are two likely possibilities. Amyloidosis is a relatively rare cause of CTS and had previously been thought to occur almost exclusively in patients with multiple myeloma. We report seven patients on chronic hemodialysis who developed CTS and were shown to have amyloid deposition within the synovium. Amyloid was demonstrated by characteristic staining with Congo red on polarizing microscopy and confirmed by electron microscopy. Six patients also exhibited radiolucent carpal bone cysts which were histologically shown to be due to bone replacement by an amyloid-positive synovitis. The average age of the patient and time on dialysis were 59.1 and 7.9 years, respectively. Serum and urine immunoelectrophoresis and bone marrow aspirates showed no evidence for plasma cell dyscrasia in six patients, while one patient did manifest a monoclonal IgA spike. Autopsies in three patients and liver biopsy in another showed no other evidence for disseminated amyloid. These hemodialysis patients exhibited a unique syndrome of CTS, lytic lesions of the carpal bones, and amyloid deposition in the synovium and within the bone cysts.

Adult↗
PubMed2001

Effect of CO2 laser on pulpal temperature and surface morphology: an in vitro study.

OBJECTIVES: The objective of this study was to evaluate the potential effects on underlying dental hard tissues of a high pulse rate carbon dioxide (CO2) laser that was designed for soft tissue surgery. METHODS: Eighteen extracted human teeth were sectioned longitudinally, cleaned, and varnished, leaving nine exposed windows on each: six on the coronal surface (enamel) and three on the root surface (cementum, dentin). The CO2 irradiation conditions used were: wave length 10.6 microm; 1.2-2.6J/cm(2) fluence per pulse; repetition rate 120-1000Hz; 100-200ms pulse duration; and cumulative fluences ranging from 14 to 2200J/cm(2). Each window was irradiated with a 0.3mm beam diameter at one of nine power settings for 0.1, 0.5, or 1.0s. The pulp chamber temperature was measured with a microthermocouple. The irradiated teeth were evaluated by Polarized Light Microscopy (PLM) and Scanning Electron Microscopy (SEM). RESULTS: The pulp chamber temperature rise ranged from 0.5 to 19 degrees C depending on the location of the window and distance to pulp chamber. SEM revealed crystal fusion in both enamel and dentin at all cumulative fluences. At cumulative fluences of 40J/cm(2), 200 pulses/second and higher, measurable tissue loss was observed with PLM both in dentin and enamel. CONCLUSIONS: These results indicate there are threshold conditions above which pulsed CO2 laser light used for soft tissue surgery may cause detrimental changes to underlying oral hard tissue and to the pulp.

Body Temperature↗
PubMedDate not supplied

In vitro secondary caries inhibition around fluoride releasing materials.

Objectives of the study were to compare the capacity of fluoride releasing materials to inhibit in vitro caries formation and to measure the width and height of the inhibition zones. Box-shaped cavities were prepared on bovine root dentine and restored with Fuji II, Fuji II LC. Vitremer, or Clearfil Liner Bond II system with a fluoride releasing composite. After immersion in a buffered demineralizing solution of 50 mmol/L acetic acid adjusted to pH 4.5 for 3 days, longitudinal sections were cut and imbibed in quinoline for analysis under a polarized light microscope (PLM). The contours of the lesions and inhibition zones were traced and their depth, width and height calculated. The data were analyzed by one-way ANOVA and Fisher's PLSD test at 95% level of confidence. The polarized light microscopy results showed a distinct inhibition zone adjacent to both conventional and resin-modified glass ionomer cements; however, it was not observed around the adhesive resin system. The width and height of this inhibition zone were significantly greater for Fuji II than for Fuji II LC and Vitremer. An inhibition zone was not observed adjacent to the adhesive resin system with fluoride releasing composite. The resin-modified glass ionomer cements produced less protection against in vitro secondary caries formation than the conventional glass ionomer cement. The recent bonding system that releases fluoride failed to produce an inhibition zone along the cavity wall adjacent to the restoration.

Acetates↗
PubMed1984

Microvascular changes in Dupuytren's contracture.

Previous studies of certain fibrotic lesions (hypertrophic scar, keloid, pseudotendon) have revealed pervasive microvascular occlusion. Lowered oxygen tension is considered to be a stimulus to excessive collagen production and, hence, the scar. Because its characteristics are similar to those of other lesions, Dupuytren's contracture appeared to be a good model in which to confirm the presence of occluded microvessels. Six cases were examined by light, electron, and polarizing microscopy. Most of the microvessels from the precontracture band area throughout the periphery of the body of the nodules were occluded by a bulging of the endothelial cells into the lumen. The microvessels were surrounded by extensive layers of basal laminae. The nodules were essentially avascular. The presence of another fibrotic lesion in which pervasive microvascular occlusion occurs is suggestive of an underlying biologic principle concerning the generation of all fibrotic lesions.

Basement Membrane↗
PubMed2003

Inter-comparison of unrelated fiber evidence.

The foreign textile fibers recovered from one item of evidence from each of 20 unrelated crimes in three categories (bank robbery, kidnapping, and homicide) were cross-compared. The items of evidence were scraped to remove the trace evidence and a sample of the collected fibers was examined using a standard scheme of analysis. The fibers were examined with light microscopy (including polarized light microscopy), fluorescence microscopy, and microspectrophotometry. The fibers were divided into natural and manufactured groups and then categorized by color and generic (polymer) class. Cross-comparing all 2083 fibers resulted in 2,168,403 comparisons, after removing duplicate (same fiber) comparisons. Colorless and denim fibers were excluded from this study. No two fibers were found to exhibit the same microscopic characteristics and analytical properties. Therefore, it is rare to find two unrelated items that have foreign fibers that are analytically indistinguishable. These results corroborate other population studies conducted in Europe and target fiber studies conducted both in the US and in Europe.

Journal Article↗
PubMed1985

Homografts of the tympanic membrane with malleus; histological study in cat.

The present experiments on cats were performed to explore the process of survival and take of transplanted homografts of tympanic membrane with malleus, the homografts being respectively preserved in 4% and 0.5% formalin (pH 7.0) solutions, and to explore the reaction of middle ear mucosa of the recipient. The present study also included gross and histopathological examinations of the eardrum and observation of fibers of the lamina propria of the transplanted tympanic membrane by means of polarizing microscopy and of vascularization by intravascular India ink injection. The experiments conducted using a total of 96 cats yielded results leading to the following conclusions. 1) After six months the transplanted tympanic membrane showed nearly normal histologic features, with a fibrous layer between the lining epithelial and thin mucosal layers. The middle ear mucosa also became thinner and was covered with ciliated epithelium at this stage. 2) As regards vascular distribution, most vessels entered from the peripheral regions to become distributed all over the eardrum with mutual anastomoses. 3) Fibrous tissues of the lamina propria of the pars tensa of the transplanted eardrum remained intact over the six month period. 4) The transplanted malleus was neither destroyed not absorbed, and proved to survive well with active vascularization. 5) The microscopic changes observed in the middle ear mucous membrane of the recipient showed non-specific reactions to Gelfoam. The grafts were not subjected to immunological rejection. Homograft thus offer the best grafting material, but seemed to show poor resistance to infection.

Animals↗
PubMed2000

Influence of temperature and time on thermally induced forces in corneal collagen and the effect on laser thermokeratoplasty.

PURPOSE: To investigate thermomechanical aspects of corneal collagen denaturation as a function of temperature and time and the effect of the induced forces on refractive changes with laser thermokeratoplasty (LTK). SETTING: Medical Laser Center Lübeck, Lübeck, Germany. METHODS: In a material-test setup, porcine corneal strips were denatured in paraffin oil at various constant temperatures for 10 and 500 seconds, and the temporal course of the contractive forces was studied under isometric conditions. Typical LTK lesions were performed in porcine eyes in vitro with a continuous-wave infrared laser diode at a wavelength of 1.87 microm for 10 and 60 seconds. The laser power was chosen to achieve comparable denatured volumes at both irradiation times. The refractive changes were measured and analyzed by histologic evaluations and temperature calculations. RESULTS: The time course of the induced forces was characterized by a maximal force, which increased almost linearly with temperature, and a residual lower force. After 500 seconds of heating, the highest force was achieved with a temperature of 75 degrees C. With a limited heating period of only 10 seconds, the forces steadily increased with temperature over the entire observation period. Laser thermokeratoplasty produced less refractive change after 10 seconds of irradiation than after 60 seconds, although the laser power was 25% higher in the short heating period. Polarization light microscopy of LTK lesions revealed different stages of thermal damage. CONCLUSION: The course of the contractive forces during and after heating is a complicated function of the spatial time/temperature profile. Laser thermokeratoplasty lesions produced with 2 irradiation times showed different stages of denaturation and induced refractive change.

Animals↗
PubMed1998

Diode laser thermokeratoplasty: application strategy and dosimetry.

PURPOSE: To investigate suitable application parameters for efficient hyperopic correction by laser thermokeratoplasty (LTK) using mid-infrared laser diodes. SETTING: Medical Laser Center Lübeck, Lübeck, Germany. METHOD: A tunable continuous-wave laser diode in the spectral range between 1.845 and 1.871 microns was used. Transmitted by waveguides, the laser energy was used to induce coagulations on freshly enucleated porcine eyes to increase corneal curvature. The coagulations were equidistantly applied by a fiber-cornea contact and a noncontact focusing device that were adjusted on a ring concentric to the corneal apex. Different laser parameters and application geometries were evaluated. Refractive changes were measured by computer-assisted corneal topography before and after treatment. Polarization light microscopy and temperature calculations were used to analyze the coagulations. RESULTS: Because of the tunability of the laser diode, the influence of the corneal absorption coefficient (between 0.9 and 1.6 mm-1) on the refractive change could be measured. A laser power between 125 and 200 mW was adequate to achieve refractive changes up to 10.0 diopters. In the preferable focusing device, the refractive change increased almost logarithmically with the irradiation time up to 15 seconds. The number of coagulations on a fixed application ring showed no significant influence on refractive change; however, it showed an almost linear decrease with increasing ring diameter from 5.0 to 10.0 mm. Histological analysis revealed 3 stages of thermal damage. CONCLUSION: Diode LTK provided defined and uniform coagulations when using a well-adapted focusing device, resulting in sufficient refractive change. The results indicate that diode LTK is superior to pulsed holmium LTK.

Absorption↗
PubMed2003

Pathology of the temporomandibular joint of patients with rheumatoid arthritis--case reports of secondary amyloidosis and macrophage populations.

INTRODUCTION: The pathogenetic features of rheumatoid arthritis of the temporomandibular joint (TMJ) are not well defined. In this paper the histological features of TMJs affected by rheumatoid arthritis, and the detection of secondary amyloidosis and macrophage populations in the TMJs of two patients with progressive rheumatoid arthritis are described. METHODS: In two patients (64-year-old man and 61-year-old woman) with rheumatoid arthritis total TMJ replacement were performed. The surgical specimens were studied histologically. RESULTS: It was found that the articular cartilage had been completely replaced by proliferating fibrous tissue. Congo red staining and polarizing microscopy revealed amyloid deposition in the connective tissue of the joint space. Immunohistochemical staining showed CD 68 positive macrophages around the amyloid deposition in the proliferating soft tissue. CONCLUSION: TMJ involvement in rheumatoid arthritis followed the same destructive pathway as in other joints. Amyloid deposition and macrophage populations were detected in two TMJs affected by rheumatoid arthritis.

Amyloid↗