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PubMed1990

Microcystic adnexal carcinoma: a light microscopic, immunohistochemical and ultrastructural study.

We report a case of microcystic adnexal carcinoma (MAC) occurring on the upper lip of an 82-year-old woman. Microscopically the tumor showed both pilar and sweat gland differentiation, involved the entire dermis and subcutaneous tissue, and invaded perineural spaces. Immunoperoxidase studies revealed carcinoembryonic antigen to be present in the ductal lining cells and in the amorphous content in the lumen, confirming sweat gland differentiation. The S-100 protein was positive in dendritic cells within the solid cell nests, but negative in cells lining cystic spaces. Ultrastructural study confirmed that the neoplasm was composed of two components, with pilar and eccrine differentiation. The former showed concentric layers of squamous epithelial cells with well-developed desmosomes and cytofilaments. The latter had ductal and alveolar structures; the ultrastructural features included: i) numerous villous folds of plasma membrane to interdigitate each other by focal desmosomes, ii) aggregates of cytofilaments, and iii) basally located myoepithelial cells which were separated from the surrounding stroma by rather thick basement membrane. In addition, distinct amyloid deposition was also observed on ultrastructural examination. To our knowledge, amyloid deposition has not been previously reported in MAC.

Aged↗
PubMed1981

Human non-A, non-B hepatitis: ultrastructural alterations in hepatocytes.

Ultrastructural investigation of liver biopsies from two patients with non-A, non-B hepatitis revealed cytoplasmic and nuclear alterations in the hepatocytes. The lesions in both patients, one with acute and one with chronic hepatitis, were similar and distinct from those previously described in other forms of hepatitis. These findings are compared with the reported findings in chimpanzee liver after inoculation with non-A, non-B infective material. The intranuclear findings are similar to the aggregations of 20-27 nm particles described in some infected chimpanzees, and the cytoplasmic alterations seem to be similar to the cytoplasmic structures and tubular arrangements reported in other inoculated chimpanzees. A striking finding of this study is the presence of both alterations together in the same biopsy in two different patients, suggesting that they represent a different stage of viral infection or different parts of the viral agent. It still remains to be proved that the ultrastructural particles indeed contain antigen(s) of the non-A, non-B hepatitis virus. The nuclear and cytoplasmic alterations are, however, characteristic for non-A, non-B hepatitis and are useful as ultrastructural hallmarks of this form of hepatitis.

Adult↗
PubMed1986

Histological and ultrastructural examination of the intrahepatic biliary tree in primary sclerosing cholangitis.

Intrahepatic bile ducts were examined histologically and ultrastructurally in wedge-biopsied liver specimens from three patients with primary sclerosing cholangitis. Bile ducts with periductal concentric fibrosis, which is a characteristic finding in primary sclerosing cholangitis, revealed ultrastructurally finger-like projections or fine undulations of the basal free surfaces with markedly duplicated basal lamina. The lamina was collared by a layer of elongated fibroblasts and thickened bundles of collagen fibers outwards. These changes were consistently found in all sizes of ducts examined, and might be related to progressive periductal fibrosis. Serial section observations showed that some severely affected ducts actually disappeared when accompanying severe periductal fibrosis. It would therefore appear that progressive periductal fibrosis may interrupt fluid and nutrient exchange between the bile duct epithelia and peribiliary capillary plexus, followed by obliteration of the biliary lumina. Although the bile ducts showed segmentally periductal lymphocytic infiltration and, ultrastructurally, point contacts between infiltrating lymphocytes and biliary epithelial cells were observed occasionally, the exact role of infiltrating lymphocytes in the pathogenesis of primary sclerosing cholangitis remains unclear.

Adult↗
PubMed1984

Ultrastructural cytochemistry of oxytalan fibers in the periodontal ligament and microfibrils in the aorta with the periodic acid-thiocarbohydrazide-silver proteinate method.

Fullmer's oxytalan fibers are special connective tissue fibers in periodontal ligaments and some non-dental sites of certain animal species, and, ultrastructurally appear to resemble microfibrils related to elastogenesis. The present study has ultrastructurally examined the applicability of Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for vicinal glycol-containing complex carbohydrates to the study of oxytalan fibers in rat periodontal ligaments and microfibrils of the tunica adventitia in the rat aorta, where microfibrils are often associated with amorphous elastin and are thought to be oxytalan fibers. In the periodontal ligaments, the PA-TCH-SP method weakly to moderately stained collagen fibrils, moderately stained thin fibrils composing the oxytalan fibers, and intensely stained cytoplasmic granules of fibroblasts. In the aortic adventitia, the PA-TCH-SP method moderately stained collagen fibrils. Heavier staining was observed in microfibrils, whereas the amorphous elastin lacked staining. The most intense staining was seen in cytoplasmic granules and glycogen of mural cells. These studies demonstrate that oxytalan fibers in the periodontal ligament of rats and microfibrils in the aorta of rats contain vicinal glycol-containing glycoproteins and the PA-TCH-SP method is a useful tool in ultrastructural studies of oxytalan fibers and microfibrils of rats.

Animals↗
PubMed1986

Malignant fibrous histiocytoma of the tongue: report of a case and ultrastructural observations.

A 42-year-old female presented with a 2.5 cm symptomless swelling on the left lateral surface of the tongue. Histologically, there were large, often pleomorphic, fibroblast-like and histiocyte-like cells, multinucleate giant cells and cells of variable morphology. Many of the cells had abundant vesicular cytoplasm. There were also aggregations of neutrophilic or eosinophilic leukocytes, or both. The cells in some areas formed a fascicular or storiform pattern, or both. Ultrastructurally, the vesicular appearance was due mostly to markedly dilated endoplasmic reticulum, but many of the neoplastic cells contained some lipid. There were some myofibroblasts and a few xanthofibroblasts. The cells of variable morphology had many of the ultrastructural features of the fibroblast and histiocyte-like cells. There were also some small undifferentiated cells with minimal cytoplasm. These ultrastructural features confirmed the histological diagnosis of malignant fibrous histiocytoma.

Adult↗
PubMed1999

Immunohistochemical and ultrastructural study of a papillary cystadenocarcinoma arising from the sublingual gland.

Immunohistochemical and ultrastructural findings in a rare case of papillary cystadenocarcinoma arising from the left sublingual gland of a 55-year-old Japanese man are reported. Histologically, the tumor tissue was found to be composed of various-sized cystic cavities in which papillary epithelial projections with thin fibrovascular cores were observed. The papillary projections consisted of a single layer to several layers of high columnar epithelial cells. Invasion to the surrounding fibrous tissue and into the lymphatics was observed, thus suggesting an aggressive potential in the present case. The possibility of the involvement of myoepithelial cells could be excluded based on the immunohistochemical and ultrastructural findings. The immunohistochemical and ultrastructural findings also suggested that this type of salivary gland tumor, at least the present case, may arise from striated or excretory ducts. There was positive immunostaining for tumor markers CA19-9 and CA125. However, the biological role of these carbohydrate antigens in salivary gland tumors is unclear at present. Further investigations are, therefore, called for to solve this issue.

Biomarkers, Tumor↗
PubMed1988

Ultrastructural changes produced in Ehrlich ascites carcinoma cells by ultraviolet-visible radiation in the presence of melanins.

Irradiation of Ehrlich ascites carcinoma (EAC) cells in the presence of pheomelanin, i.e., red hair melanin (RHM), has been reported to produce extensive cell lysis. Irradiation in the presence of eumelanin, i.e., black hair melanin (BHM), or irradiation in the absence of either type of melanin did not produce this effect. We observed that RHM particles penetrated the cell membrane without apparent structural damage to the cell or the cell membrane. Irradiation of the cells in the absence of melanin did not produce any changes in the ultrastructure of the cells. Incubation of the cells in the dark in the presence of RHM produced only minor structural, mainly cytoplasmic changes. Irradiation of the cells in the presence of RHM produced extensive ultrastructural changes prior to complete cell lysis; these changes were more severe than the effects of incubation of the cells in the dark in the presence of RHM. When the cells incubated in the dark or irradiated in the presence of latex particles or either one of the eumelanins particles, viz. BHM or synthetic dopa melanin, these particles did not penetrate into the cells or produce any ultrastructural changes. These particles were in fact not even ingested by the cells.

Animals↗
PubMed2006

Ultrastructural clues for the protective effect of melatonin against oxidative damage in cerulein-induced pancreatitis.

The role of oxidative stress has been evaluated in experimental models of acute pancreatitis (AP). The aim of this study is to investigate the effect of melatonin on the ultrastructural changes in cerulein-induced AP in rats. Acute pancreatitis was induced by two i.p. injections of cerulein at 2-hr intervals (50 microg/kg BW). One group received additionally melatonin (20 mg/kg BW) i.p. before each injection of cerulein. The rats were sacrificed 12 hr after the last injection. Pancreatic oxidative stress markers were evaluated by changes in the amount of lipid peroxides and changes in the antioxidant enzyme levels, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and total glutathione (GSH) levels. Ultrastructural examination was performed using a transmission electron microscope. Formation of numerous, large autophagosomes, mitochondrial damage, dilatation of rough endoplasmic reticulum (RER) and Golgi apparatus, margination and clumping of nuclear chromatin were the major ultrastructural alterations observed in the AP group. Melatonin administration prevented mitochondrial and nuclear changes and dilatation of RER and Golgi apparatus. Rare, small autophagosomes were present within the cytoplasm of some of the acinar cells. Pancreatic damage was accompanied by a significant increase in tissue MDA levels (P < 0.05) and a significant decrease in CAT, SOD, GPx activities and GSH levels (P < 0.005). Melatonin administration significantly reduced MDA levels but increased CAT, SOD, GPx activities and GSH levels (P < 0.005). Melatonin also reduced serum amylase and lipase activities, which were significantly elevated in AP (P < 0.05 and P < 0.005 respectively). These results suggest that oxidative injury is important in the pathogenesis of AP. Melatonin is potentially capable of limiting pancreatic damage produced during AP by protecting the fine structure of acinar cells and tissue antioxidant enzyme activities.

Acute Disease↗
PubMed1995

Clinical, microbiological and ultrastructural features of angular cheilitis lesions in Southern Chinese.

OBJECTIVE: To obtain baseline data on angular cheilitis in Southern Chinese. DESIGN: A cross-sectional investigation of the clinical, microbiological and ultrastructural features of the condition. SUBJECTS AND METHOD: Thirty six Chinese adults with angular cheilitis; 28 controls matched for age and sex, with no inflammation. Clinical examination, swabs of lesions for microbiology, impressions of lesions for ultrastructure, using replica technique. MAIN OUTCOME MEASURES: Severity of lesions, associated signs and symptoms, incidence and type of microorganisms, ultrastructural features. RESULTS: Of a total 68 lesions 32 were bilateral and four unilateral. Forty four (65%) were mild (Type I) and the remaining 24 (35%) moderate (Type II). Infective agents were isolated from 37 (54%) lesions; pure growth of Candida spp and Staph. aureus was noted in nine lesions each; a mixed growth of the two in II, beta-haemolytic streptococci in three and a mixed flora including coliforms in the other five. Candida spp were present in one control, beta-haemolytic streptococci in two and coliforms in four others. Scanning electron microscopy revealed natural topography of the angular skin with sparse colonisation by bacteria and yeasts. CONCLUSIONS: Angular cheilitis in Southern Chinese seems to be characterised by a milder clinical presentation and classic infective agents of the disease: Candida spp and Staph. aureus.

Adult↗
PubMed1979

The ultrastructure of liposarcoma. A study of 10 cases.

An ultrastructural study of 10 liposarcomas is reported. Four of the liposarcomas were wholly or predominantly of well-differentiated, lipoma-like or fibrosing type, 3 of myxoid type, 2 of round cell type and 1 pleomorphic type. The well-differentiated, lipoma-like liposarcomas showed cells with a few, large lipid droplets, few organelles and a peripherally located, fairly large nucleus, The well-differentiated liposarcomas of fibrosing type revealed mostly spindle-shaped, fibroblast-like cells, with abundant rough endoplasmic reticulum and inconspicuous lipid inclusions, surrounded by collagen. One well-differentiated liposarcoma contained an area which was similar to brown adipose tissue and hibernoma. The spindle and stellate shaped cells of the myxoid liposarcomas showed abundant rough endoplasmic reticulum and large smooth-membraned vacuoles filled with moderately dense amorphous material, which appeared to be extruded extracellularly by rupture of the vacuoles. Cytoplasmic lipid droplets were seen in most cells but were much less prominent than in the well-differentiated lipoma-like liposarcomas. Ultrastructurally there were many similarities between the myxoid and round cell liposarcoma, indicating a close relationship between the two types. The pleomorphic liposarcoma revealed cells with one or more large, irregular nuclei, numerous large vacuoles after dissolved lipids, abundant dilated cisternae of rough endoplasmic reticulum and rounded, electron-dense bodies corresponding to PAS-positive hyalin globules seen in the light microscope. The ultrastructural study suggests that the variegated cellular appearance of the different subtypes of liposarcoma reflects the wide cellular spectrum seen during the differentiation of adipose tissue and supports the view that all liposarcomas histogenetically represent a single entity.

Adipose Tissue↗
PubMed1982

Ultrastructural changes in the nucleus of a human epithelial cell line exposed to cytotoxic agents. The effect of PUVA and cadmium.

An established human epithelial cell line was exposed to cytotoxic doses of photo-activated 8-methoxy psoralen (PUVA) and to cadmium (Cd++) and the cells' nuclear ultrastructure were compared with controls. PUVA and Cd++ have some common biological features. Both substances induced nuclear indentations and cytoplasmic invaginations, while only PUVA caused an increase in nuclear bodies. After cadmium exposure, clusters of large-sized perichromatin granules (PG) were seen as well as an increase in chromatin margination. After PUVA, an increase in singularly distributed PGs was observed. The nuclear envelope was not affected by PUVA while Cd caused extensive disruption of this membrane. A strain of the epithelial cell line was made resistant to 100 mumol Cd/l and its nuclear ultrastructure was examined. An increase in chromatin margination was seen compared with its parent line. When this Cd resistant cell strain was exposed to 200 mumol Cd/l no ultrastructural changes took place. An attempt to produce a PUVA resistant epithelial cell strain was unsuccessful. Some functional aspects of the different morphological parameters observed are discussed.

Cadmium↗
PubMed1987

Chemical inducers of differentiation, dimethylsulfoxide, butyric acid, and dimethylthiourea, induce selective ultrastructural patterns in B16 melanoma cells.

The morphology and ultrastructure of B16 melanoma cells was examined after treatment of the cells with the chemical inducers of differentiation dimethylsulfoxide (DMSO), butyric acid, and dimethylthiourea (DMTU). The treated B16 melanoma cells seemed to be enlarged and more flattened, and to possess dendrite-like structures as revealed by scanning electron microscopy. The main ultrastructural features, depicted by transmission electron microscopy in DMSO-treated B16 cells were: a marked increase in melanin granules, migration of the melanin granules to the dendrites, and appearance of melanosome aggregates. Butyric acid did not induce melanin biosynthesis; however, it stimulated rough endoplasmic reticulum (RER) formation all over the cytoplasm. The DMTU-treated cells also showed a well developed RER accompanied by early stages of melanosomes and melanin granules. The increase in the endoplasmic reticulum was also reflected by enhancement of NADPH cytochrome c reductase activity, an enzymatic marker of the endoplasmic reticulum. The mitochondria in the DMTU-treated cells were swollen with disrupted cristae. The results indicate that DMSO, butyric acid, and DMTU induce different ultrastructural patterns in B16 melanoma cells. These findings correlate with the biochemical alterations induced in melanoma cells by these agents.

Animals↗
PubMed2003

Ehlers-Danlos-like syndrome in 2 dogs: clinical, histologic, and ultrastructural findings.

BACKGROUND: Ehlers-Danlos syndrome comprises a group of rare inherited connective tissue diseases characterized by skin hyperextensibility, joint laxity, skin and vessel fragility, and poor wound healing. OBJECTIVE: The purpose of this report was to describe the clinical, histologic, and ultrastructural findings in 2 dogs with collagenopathies consistent with Ehlers-Danlos syndrome. METHODS: Two dogs were examined clinically; skin extensibility index was calculated. Skin biopsies obtained from the dorsum were examined by light and electron microscopy. RESULTS: Both dogs had clinical signs of skin hyperextensibility and fragility, lower skin elasticity, vessel fragility, and poor wound healing. One dog had a hip dislocation, and the other had bilateral medial patellar luxation (grade II), subcutaneous hematomas produced by minimal trauma, and generalized periodontitis. Histologic and ultrastructural examination confirmed abnormalities in the structure and arrangement of collagen fibrils. Fibroblasts were characterized by variable dilatation of the rough endoplasmic reticulum, and anomalous elastic fibers (elaunin fibers) were present in the dermis. CONCLUSION: Although the primary defects underlying collagenopathies in animals are still unknown, analysis of the ultrastructural changes in collagen fibrils and clinical findings could facilitate better characterization of these disorders in dogs.

Animals↗
PubMed1974

The ultrastructure of the carotid body in chronically hypoxic rabbits.

1. The ultrastructure of the carotid body in the rabbit has been examined by electron microscopy.2. A comparison was made between the ultrastructure of the carotid bodies in sea level rabbits, in rabbits which had been exposed to hypoxia equivalent to an altitude of 6000 m for 7 days and in rabbits which always had lived at an altitude of 4000-4300 m.3. We could not detect any difference in the ultrastructure between the two groups of hypoxic rabbits.4. When the hypoxic rabbits were compared with sea level rabbits there was a marked increase in the number of dense cored vesicles and mitochondria in the type I cells in the hypoxic rabbits. The Golgi region also appeared to be enlarged in the type I cells in the hypoxic rabbits.5. The finding suggests that in the rabbit the production of amines, probably dopamine, within the type I cells is increased during prolonged hypoxia which might explain the lowered ventilatory response to hypoxia observed in human high altitude residents.6. If the carotid bodies are organs of internal secretion the finding is compatible with an increased production of a hormone produced within the type I cells.

Altitude↗
PubMed1975

In vitro effects of amphotericin B on growth and ultrastructure of the amoeboflagellates Naegleria gruberi and Naegleria fowleri.

In vitro effects of the polyene antibiotic amphotericin B (AmB) on growth, viability, and ultrastructure of amoeboflagellates of the genus Naegleria were examined. The strains studied were the nonpathogenic Naegleria gruberi EG(B) and the Carter and TY strains of the pathogenic Naegleria fowleri. AmB was amoebicidal at all concentrations used (0.25, 0.50, and 1.0 mug/ml) when the drug was added to cultures in lag phase, as determined by viability testing, but was mainly inhibitory when added to log-phase cultures. The drug produced ultrastructural modifications at all concentrations (0.05 to 1.0 mug/ml). These changes included distortion of nuclear shape, increase in cytoplasmic membranes (both rough and smooth endoplasmic reticulum), decrease in number of food vacuoles, absence of pseudopod formation, mitochondrial abnormalities, increase in autophagic vacuoles, and blebbing of the plasma membrane. These alterations of amoebic ultrastructure became more pronounced with increased time in AmB and with increase in AmB concentration in the growth medium.

Amoeba↗
PubMed1980

Ultrastructural observations on cellular and subcellular aspects of experimental Mycoplasma pneumoniae disease.

The ultrastructural organization of Mycoplasma pneumoniae membranes and spatial relationships of this pathogen to epithelial cells in tracheal organ cultures were examined ultrastructurally by freeze-fracture techniques. Areas of morphologically distinct cell membrane variability characterized by membrane blebs and altered distributions of membrane associated particles were observed in replicas of M. pneumoniae cells. Inspection of the host tracheal epithelium demonstrated the alignment of M. pneumoniae to the epithelium with an accompanying deterioration in the integrity of the lumenal surface membranes and subsequent loss of the epithelial cell cytosol. Ciliary dysfunction was suggested by the observation of ciliary lesions and of disorganized epithelial cell cilia. The methodology used in these studies has permitted a new perspective of host-pathogen interactions at both the cellular and subcellular levels in tracheal organ cultures. These studies may also illustrate ultrastructural correlates of the alteration of host macromolecular synthesis in experimental M. pneumoniae infection.

Animals↗
PubMed1970

Ultrastructure of a temperature-sensitive rod- mutant of Bacillus subtilis.

Mutant 168ts-200B, resulting from nitrosoguanidine treatment of Bacillus subtilis 168 (trp(-) C2), exhibits a rod-to-sphere morphogenetic interconversion when the incubation temperature is 30 or 45 C, respectively. Ultrathin sections of rods grown at 30 C, after glutaraldehyde-osmium uranium-lead fixation and staining, show trilaminar cell walls with a well-developed underlying periplasm as in wild-type cells. However, the outer wall layer is irregular, and abnormal protrusions of wall material occur at the cross-walls. In contrast, cells growing at 45 C become rounded and are intersected randomly by irregular cross-walls which fail to split normally, resulting in large spherical masses. In these, the outer and inner wall layers and periplasm are lost, and the wall consists only of irregularly thickened and loosely organized middle layer. Wall ultrastructure is reversible in either direction as cell shape changes during temperature shifts. Mesosomes are rare and atypical at either temperature. It thus appears that cell wall ultrastructure is altered by the conditional (temperature-sensitive) mutation, and that loss of normal wall and submural organization is correlated with changes in cell size and shape as well as with inability to complete cell division. Preliminary studies after transformation of the mutant locus to another strain and growth at 45 C showed an increase in mucopeptide, loss of wall teichoic acid, failure of phage adsorption, and identical ultrastructural changes. The site of expression of the basic defect-be it in wall, submural region, or membrane-is undetermined.

Bacillus subtilis↗
PubMed1985

Effect of nitrogen starvation on the morphology and ultrastructure of the cyanobacterium Mastigocladus laminosus.

The effects of nitrogen starvation on the morphology and ultrastructure of the branching, filamentous cyanobacterium Mastigocladus laminosus were examined with light and electron microscopy. The internal ultrastructural characteristics of vegetative cells changed markedly during nitrogen starvation. Carboxysomes were degraded, while polyphosphate bodies and lipid bodies accumulated. The ultrastructure of mature heterocysts was also affected by nitrogen starvation; their intracytoplasmic membranes vesiculated to form vacuolelike structures and, eventually, large empty regions in the cytoplasm. Nitrogen starvation stimulated extensive heterocyst differentiation in M. laminosus, producing heterocyst frequencies of 17.5% in narrow filaments and 28.3% in wide filaments within 44 h after transfer to N-free conditions. Cells in wide filaments differentiated so extensively that only 16.8% of them failed to initiate the differentiation process within 44 h.

Cyanobacteria↗