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PubMed1987

Ultrastructural changes induced in the isolated rat heart by enzymatically generated oxygen radicals.

This study describes the effect of oxygen radicals on the ultrastructure of the isolated Langendorff-perfused rat heart. Oxygen radicals were enzymatically generated by xanthine oxidase (0.025 U/ml) and hypoxanthine (0.96 mM). Hearts were perfusion-fixed for electron microscopy and stereological technique was performed to obtain estimates of volume fractions (Vv) of different tissue components. Perfusion with oxygen radicals resulted in areas with severely damaged myocardial cells. These changes included swelling and cristolysis of mitochondria, disruption of filaments, development of intracellular edema and focal disruption of the sarcolemma. Stereological examination revealed few alterations after 5 min perfusion with oxygen radicals. After 10 min perfusion with oxygen radicals, however, the Vv (myocyte/myocardium) increased from 0.542 +/- 0.042 (mean +/- S.D.) to 0.663 +/- 0.144, and this paralleled the development of Vv (cellular edema/myocyte) being 0.047 +/- 0.028. Vv (capillary wall/capillary) increased from 0.215 +/- 0.046 to 0.411 +/- 0.123 indicating endothelial swelling. Although the mitochondria appeared swollen, Vv (mitochondria/myocyte) remained constant. The effect of a 35 min recovery period on the ultrastructure was minor. The application of SOD and catalase together with xanthine oxidase and hypoxanthine reduced the observed changes significantly, thus proving the participation of oxygen radicals. This study confirms that oxygen radicals can induce major alterations in myocardial ultrastructure.

Animals↗
PubMed1983

Electron microscope analysis of tissue components identified and located by computer-assisted 3-D reconstructions: ultrastructural segmentation of the developing human proximal tubule.

A method is described for ultrastructural analysis of renal tubules after precise identification of tubule segments by computerized 3-D reconstruction at the light microscope level. Semithin serial sections were cut of entire nephrons and 3-D coordinate information was obtained by digitization of tubule cross sections in the semithin sections. With the aid of the computer the tubule axis was traced from one section to the other. Precise lengths and positions of the tubules in three dimensions were calculated and stereoscopic images generated. The method was used to analyze the 3-D structure of developing human nephrons, and the ultrastructural development of the proximal tubule. Ultrastructural segmentation of the proximal tubule was demonstrated in the human fetal nephron in developmental stage IV.

Computers↗
PubMed1987

Histopathologic and ultrastructural correlates of tumor growth suppression by high energy shock waves.

High energy shock waves (HESW) are cytotoxic to tumor cells as determined by vital staining and impaired ability of viable cells to form colonies in a clonogenic assay. In addition, direct exposure of tumor nodules to HESW results in suppression of tumor growth rate. In order to identify histopathologic and ultrastructural correlates of these observations, R3327AT-3 prostatic tumor cells were exposed to HESW in vitro and in vivo. Damage to cells in suspension was manifested by fragmentation of cells to form debris. At the ultrastructural level, mitochondria were swollen and contained distorted cristae following exposure of tumor cells to HESW. In vivo exposure of tumor nodules to HESW did not cause a distinct histopathologic or ultrastructural effect that could be qualitatively distinguished from spontaneously occurring cell death. Hemorrhage and necrosis were observed in muscle and fibroadipose tissue adjacent to tumor. The mechanism of HESW-induced cytotoxicity is not clear from our studies. Evidence of damage of normal tissues exposed in vivo and tumor cells in vitro is reflected in histomorphological changes.

Animals↗
PubMed1979

The ultrastructural changes of prostate adenocarcinoma following external beam radiation therapy.

Ultrastructural studies were done to determine the effects of radiation therapy on prostatic adenocarcinoma. Twenty patients were included in the study: 6 with benign hyperplasia, 4 with untreated adenocarcinoma and 10 with adenocarcinoma who had received radiation therapy. Benign and malignant ultrastructural characteristics were established. On the basis of these characteristics 6 of the 10 radiated prostates were believed to have tumor cells present after therapy. Of the remaining 4 patients 3 had ultrastructural changes suggesting radiation effects and a possibly altered malignant potential.

Adenocarcinoma↗
PubMed2000

The use of electron microscopy in the investigation of the ultrastructural morphology of immune thrombocytopenic purpura platelets.

Ultrastructural studies have proven useful for the accurate identification and classification of certain lymphoid and hematopoietic disorders; however, the value of electron microscopy in the diagnosis and clinical management of platelet pathology is less well defined. Electron microscopy has been used to evaluate inherited platelet disorders. In these disorders, certain platelet structural defects can be characteristic. Recently, we investigated the ultrastructural morphology and immunogold localization of IgG in platelets from patients with idiopathic thrombocytopenic purpura (ITP). The accelerated platelet destruction of ITP is mediated by antiplatelet autoantibodies directed against platelet surface glycoproteins and by the functional capacity of the reticuloendothelial system. The basic dysregulation that occurs in these patients remains unexplained. Traditionally, laboratory investigation of ITP has focused on the development of serologic assays to measure the autoantibodies. As an alternative investigative approach, determination of the immunomorphologic characteristics of platelet-associated IgG (PAIgG) in ITP platelets may prove useful in the diagnosis or clinical management of patients with ITP. Our results showed that the ultrastructural morphology of ITP platelets is similar to that observed for normal platelets. No structural abnormalities are observed in ITP platelets. Immunogold labeling of IgG within alpha-granules of ITP platelets is significantly higher than that of normal platelets. Additionally, in some ITP platelets, immunogold labeling is also observed on the platelet surface and within channels of the open-cannalicular system. In comparison, immunogold labeling of these structures in normal platelets, is rare, or absent. In conclusion, electron microscopic studies should contribute to furthering our understanding of this common autoimmune disorder, and may provide possible biological explanations for the increased levels of PAIgG in platelets from patients with ITP.

Blood Platelets↗
PubMed2002

A comparative ultrastructural study of spermatozoa of the teiid lizards Cnemidophorus gularis gularis, Cnemidophorus ocellifer, and Kentropyx altamazonica (Reptilia, Squamata, Teiidae).

The ultrastructure of the spermatozoa of Cnemidophorus gularis gularis, Cnemidophorus ocellifer, and Kentropyx altamazonica is described for the first time. Mature spermatozoa of Cnemidophorus spp. and K. altamazonica differ in the occurrence of a perforatorial base plate, the enlargement of axonemal fibers 3 and 8, and shape of mitochondria. The comparisons of the ultrastructure sperm of Cnemidophorus spp. and K. altamazonica with Ameiva ameiva [J. Morphol. (2002) in press] suggest that Ameiva and Cnemidophorus are more similar to each other than either is to Kentropyx. Statistical analyses reveal that sperm of all three species studied are significantly different in the following dimensions: head, acrosome, distal centriole length, and nuclear shoulders width. There was no variable statistically different between the Cnemidophorus spp. only. The length of the tail, midpiece, entire sperm, and nuclear rostrum are significantly different between K. altamazonica and Cnemidophorus spp. Our results indicate that sperm ultrastructure presents intra and intergeneric variability.

Animals↗
PubMed1995

An ultrastructural study of brown adipose tissue in pre-term human new-borns.

The ultrastructure of brown adipose tissue (BAT), the thermogenic type of adipose tissue, was investigated in biopsies from 4 pre-term human new-borns delivered at 25-27 week's gestational age and compared with peri-renal brown fat from 2 adult patients with phaeochromocytoma (a condition of brown fat activation). The cell size of brown adipocytes was smaller in pre-term new-borns than in adult patients; adipocytes were almost exclusively multilocular, suggesting active thermogenesis. In 3 of the pre-term new-borns, brown adipocyte ultrastructure indicated a good to high degree of differentiation (in particular at the level of mitochondria) as compared with activated brown fat cells found in adult patients; in one pre-term infant the tissue morphology was obviously suggestive of an earlier, proliferative phase of development and the differentiation process of brown adipocytes could be traced in some detail. The results suggest that (a) brown adipose tissue may be fairly well-differentiated and thermogenetically active in pre-term human new-borns weighing about 750 g at birth; (b) brown adipocytes apparently develop from vessel-associated cells, the early signs of adipocyte differentiation being glycogen and lipid accumulation; (c) the ultrastructural morphology of mitochondria of mitochondria in well-differentiated BAT from pre-term infants can strictly resemble that found in active brown adipose tissue of adult phaeochromocytoma patients.

Adipose Tissue↗
PubMed1998

Ultrastructural effects of AAL-toxin TA from the fungus Alternaria alternata on black nightshade (Solanum nigrum L.) leaf discs and correlation with biochemical measures of toxicity.

Ultrastructural effects of AAL-toxin TA from Alternaria alternata on black nightshade (Solanum, nigrum L.) leaf discs and correlation with biochemical measures of toxicity. In black nightshade (Solanum nigrum L.) leaf discs floating in solutions of AAL-toxin TA (0.01-200 microM) under continuous light at 25 degrees C, electrolyte leakage, chlorophyll loss, autolysis, and photobleaching were observed within 24 h. Electrolyte leakage, measured by the conductivity increase in the culture medium, began after 12 h with 200 microM AAL-toxin T(A), but was observed after 24 h with 0.01 to 50 microM AAL-toxin T(A), when it ranged from 25%) to 63% of total releasable electrolytes, respectively. After 48 h incubation, leakage ranged from 39% to 79% of total for 0.01 to 200 microM AAL-toxin T(A), respectively, while chlorophyll loss ranged from 5% to 32% of total, respectively. Ultrastructural examination of black night-shade leaf discs floating in 10 microM AAL-toxin TA under continuous light at 25 degrees C revealed cytological damage beginning at 30 h, consistent with the time electrolyte leakage and chlorophyll reduction were observed. After 30 h incubation chloroplast starch grains were enlarged in control leaf discs, but not in AAL-toxin T(A)-treated discs, and the thylakoids of treated tissue contained structural abnormalities. After 36-48 h incubation with 10 microM AAL-toxin T(A), all tissues were destroyed with only cell walls, starch grains, and thylakoid fragments remaining. Toxicity was light-dependent, because leaf discs incubated with AAL-toxin T(A) in darkness for up to 72 h showed little phytotoxic damage. Within 6 h of exposure to > or =0.5 microM toxin, phytosphingosine and sphinganine in black nightshade leaf discs increased markedly, and continued to increase up to 24 h exposure. Thus, phy siological and ultrastructural changes occurred in parallel with disruption of sphingolipid synthesis, consistent with the hypothesis that AAL-toxin T(A) causes phytotoxicity by interrupting sphingolipid biosynthesis, thereby damaging cellular membranes.

Alternaria↗
PubMed1975

Mental retardation, hypotonia, and generalized seizures associated with astrocytic "residual" bodies. An ultrastructural study.

Two siblings suffering since birth from convulsions, hypotonia, and mental retardation are presented. In the older sibling (eight and one-half years of age) frontal lobe biopsy revealed abnormal cytosomes with lamellar profiles in astrocytes, macrophages, and to a lesser degree in neurons. Similar cytosomes have not yet been reported in cases of sphingolipidoses or in late infantile-juvenile amaurotic idiocy. These cytosomes stained intensely with silver proteinate, an ultrastructural cytochemical stain for carbohydrate moieties. In contrast, lipofuscin did not stain with silver proteinate. Multilamellar (crescentic curvilinear) cytosomes from a reported case of late infantile amaurotic idocy (Batten-Vogt-Spielmeyer disease) did not stain with silver proteinate. Abnormal cytosomes were not found in blood cells, liver, and peripheral nerve. In the younger sibling (14 months old) postmortem ultrastructural studies of cerebral tissue showed very few abnormal cytosomes. On the basis of the clinical and ultrastructural findings, we conclude that these two cases can be distinguished from those with multilamellar (crescentic-curvilinear) inclusions and from cases of the so-called "neuronal ceroid-lipofuscinosis" syndrome.

Astrocytes↗
PubMed1978

Surface and transmission ultrastructural characteristics of desquamative interstitial pneumonitis.

A prospective study of eight patients with desquamative interstitial pneumonitis was performed, correlating surface ultrastructure as elucidated by scanning electron microscopy, transmission electron microscopy, viral cultures of fresh sterile lung tissue obtained at thoracotomy, and immunomicroscopy. The hypothesis that environmental pollutants may act as sensitizing agents to induce macrophage migration was pursued using high resolution elemental analysis to obtain a profile of the inorganic content of phagolysosomes in the free alveolar cell population. Four surface ultrastructural changes were observed: mild alveolar septal thickening, an apparent decrease in the number of pores of Kohn, alteration of the predominant alveolar lining population from membranous to granular pneumonocytes, and prominent intra-alveolar collections of cells with broad based ruffled projections and pseudopodia representing a macrophage population. Transmission electron microscopy corroborated these observations. Individual pneumonocyte degeneration manifested as cytoplasmic dissolution, mitochondrial swelling, chromatin disruption, and loss of lamellar bodies and endoplasmic reticulum was identified; occasionally degenerating granular pneumonocytes were displaced into the alveolar space by a supraseptal bulla containing fibrin and extracellular fluid. Viruses were not identified by ultrastructural or tissue culture techniques. High resolution elemental analysis of individual phagolysosome contents failed to reveal the presence of heavy metals or other inorganic compounds. Immune complexes were not identified by immunofluorescence microscopy. However, alveolar transeptal macrophage migration was observed by transmission electron microscopy. These observations suggest that desquamative interstitial pneumonitis represents a disease in which cellular, rather than humoral, immune processes predominate. Other nonspecific cellular immune responses under the influence of various lymphokines may be responsible for the observed morphologic alterations.

Collagen↗
PubMed1979

Benign lymphoepithelial lesion (Mikulicz's disease) of the salivary gland: an ultrastructural study.

An ultrastructural study of a benign lymphoepithelial lesion of the parotid gland demonstrated that the so-called epimyoepithelial cell islands were sharply demarcated from the surrounding parenchyma by a thick basement membrane containing collagen fibers. The hyaline material seen by light microscopy within the islands was ultrastructurally similar in appearance to this delimiting basement membrane. The epithelial cells within the islands were united by well formed desmosomes and many had prominent tonofilament bundles, but myogenic differentiation was not observed. Hydropic degeneration was not seen in these epithelial cells; cells with a perinuclear clear space seen by light microscopy corresponded to large lymphoid cells ultrastructurally.

Basement Membrane↗
PubMed1981

Ultrastructural lesions of bile ducts in primary biliary cirrhosis. A comparison with the lesions observed in graft versus host disease.

Intrahepatic bile duct destruction is a characteristic feature of primary biliary cirrhosis and hepatic graft versus host disease. Lymphocytotoxicity against antigens on the surface of biliary cells is one of the cell mediated immune mechanisms debated in the pathogenesis of persistent bile duct destruction during primary biliary cirrhosis. Immune complex injury has also been hypothesized. In graft versus host disease, damage to bile duct cells is also believed to be due to a cytotoxic reaction of the grafted lymphoid cells against the host histocompatibility antigens, and immune complex deposition is likely to occur. The aim in this comparative ultrastructural study of intrahepatic bile ducts in 10 patients with primary biliary cirrhosis and six patients with hepatic graft versus host disease was to investigate whether identical or different ultrastructural lesions were detected in both diseases. Features of conspicuous necrosis of biliary cells, including cytolysosomes, apoptosis, and basement membrane disruption, were observed in both diseases. Numerous lymphocytes established close membrane contacts with biliary cells, especially with the necrotic ones. They had cytoplasmic pseudopods, and some of them displayed a uropod or contained lysosomal vesicles. Abnormalities of the bile duct basement membrane, also observed in both diseases, included thickening or multilayering and numerous lucent areas of rarefaction often containing osmiophilic inclusions. The striking similarity of the ultrastructural lesions in both diseases provides an additional morphological argument to suggest that certain common pathogenic mechanisms might be involved in the destruction of bile ducts in primary biliary cirrhosis as well as in hepatic graft versus host disease.

Adolescent↗
PubMed1984

Intraosseous schwannoma: histologic features, ultrastructure, and review of the literature.

Intraosseous schwannoma, a rare benign neoplasm, has a characteristic radiographic appearance. The histologic features, although similar to those of soft tissue schwannomas, may be obscure when the lesions are highly cellular and the Antoni Types A and B patterns are subtle. Four additional cases of intraosseous schwannoma are presented, with ultrastructural studies from two tumors, one of which was highly cellular and presented a diagnostic problem. The ultrastructural features of intraosseous schwannomas have not been documented previously; however, the findings are essentially the same as those observed in soft tissue schwannomas. The radiographic, histologic, and ultrastructural findings in the cases reported are discussed in relation to published data for intraosseous and soft tissue schwannomas. The authors propose that the comparatively high frequency of mandibular involvement by intraosseous schwannoma may be related to the fact that schwannomas, in general, arise most frequently in the head and neck regions. Furthermore, since schwannomas arise mainly in association with sensory nerves, probably the dearth of such fibers within bone accounts for the rarity of intraosseous schwannoma.

Adolescent↗
PubMed1985

Undifferentiated (embryonal) sarcoma of the liver: ultrastructural and immunohistochemical similarities with malignant fibrous histiocytoma.

Two undifferentiated (embryonal) sarcomas of liver were studied ultrastructurally and immunohistochemically. Electron microscopic examination of the pleomorphic tumor cells revealed fibroblastic and histiocytic characteristics. There were no specific findings to support rhabdomyoblastic, leiomyoblastic, or epithelial differentiation. Cytoplasmic peroxidase-antiperoxidase (PAP) immunohistochemical staining for vimentin, alpha1-antitrypsin, and alpha1-antichymotrypsin was found. No staining for epidermal or internal organ cytokeratins, desmin, myoglobin, or alpha-fetoprotein was observed. The ultrastructural correlates of the cytoplasmic periodic acid-Schiff-positive, diastase-resistant hyaline globules were large, membrane-bound, heterogenous electron-dense inclusions, probably lysosomal in origin. These inclusions did not react on either alpha1-antitrypsin or alpha1-antichymotrypsin PAP staining. Tumor specimens from two metastatic sites were also examined. Neither contained the ducts or cysts that characterized the primary tumor. These studies confirm the mesenchymal nature of this uncommon childhood neoplasm and support the suggestion that the cytoplasmic hyaline globules represent a degenerative phenomenon. There are ultrastructural and immunohistochemical similarities with malignant fibrous histiocytoma.

Child↗
PubMed1986

Ultrastructural abnormalities of cilia in the human respiratory tract.

Primary ciliary dyskinesia is thought to be caused by a primary defect of ciliary ultrastructure and function. However, atypical cilia have also been described in humans with and without acquired respiratory tract disease. With few exceptions, these abnormalities have not been quantified. Ciliary ultrastructure was therefore studied in 21 specimens of bronchial mucosa from patients with a variety of respiratory problems and in five specimens of nasal mucosa from asymptomatic nonsmokers. The incidence of microtubular abnormalities and compound cilia was generally less than 10 per cent, and there was no correlation between the incidence of these abnormalities and the presence of lung carcinoma or smoking habits. Transposition of ciliary microtubules and radial spoke defects, specific microtubular abnormalities thought to be pathognomonic for primary ciliary dyskinesia, were observed in a number of specimens, and visualization of dynein arms, particularly inner dynein arms, was extremely difficult. It is concluded that ultrastructural abnormalities of cilia should be carefully quantified in patients with primary ciliary dyskinesia and control subjects before it can be assumed they have pathologic significance.

Adolescent↗
PubMed1986

Synovial sarcoma: ultrastructural study and immunohistochemical analysis by a combined peroxidase-antiperoxidase/avidin-biotin-peroxidase complex procedure.

To analyze the purportedly epithelial features of synovial sarcoma, the antigenic profiles of 20 of these neoplasms (including 12 of the monophasic type) were studied by three different immunohistochemical techniques, and the results were correlated with ultrastructural observations in 10 cases. All of the biphasic tumors were immunoreactive for the epithelial markers epithelial membrane antigen (EMA) and cytokeratin (CK) and also had ultrastructural features of epithelial differentiation. In contrast, only one of five monophasic tumors had electron microscopic features suggestive of epithelial differentiation, but eight of the 12 were immunoreactive for CK or EMA by a procedure combining the peroxidase-antiperoxidase and avidin-biotin-peroxidase complex methods. It is concluded that synovial sarcoma, including the monophasic variant, is a mesenchymal tumor with epithelial features. Immunohistochemical studies are more sensitive than ultrastructural analysis for documenting epithelial differentiation.

Adult↗
PubMed1999

Alveolar adenoma: a histochemical, immunohistochemical, and ultrastructural analysis of 17 cases.

Alveolar adenoma of lung is a rare benign neoplasm of uncertain histogenesis. Its rarity hampers characterization of its epithelial and mesenchymal elements. Clinical and histopathologic features of 17 alveolar adenomas were reviewed. Histochemistry was performed on 10 cases, ultrastructural analysis on two, and immunohistochemistry on six cases for pneumocyte markers, thyroid transcription factor (TTF-1), surfactant protein markers pro-SP-B and pro-SP-C, and the Clara cell marker, CC10. Immunohistochemistry was performed in nine cases for desmin, smooth muscle actin, muscle-specific actin, cytokeratin, proliferating cell nuclear antigen (PCNA), factor VIII, and carcinoembryonic antigen. The mean age was 53 years. Seven cases occurred in men, and nine occurred in women. The age and sex were not known for one patient. The tumors were coin lesions on chest radiographs in asymptomatic patients except for one (cough). The mean size was 2.2 cm. The tumors were well demarcated with multiple cystic spaces containing granular material. Mostly type 2 pneumocytes lined the cystic spaces with fewer type 1 cells and no Clara cells. This was confirmed by staining for TTF-1, pro-SP-B, and pro-SP-C and by ultrastructure. CC10 was negative in all cases. The stroma varied from prominent spindle cells with a myxoid matrix to thin alveolar septa. The interstitial spindle cells resembled fibroblasts by immunohistochemistry and ultrastructure. Follow-up data available in five cases showed no recurrence at 2, 2, 5, 8, and 13 years. In summary, alveolar adenoma is a benign neoplasm consisting of an intimate admixture of alveolar epithelial and septal mesenchymal tissue. Most of the epithelial cells are type 2 pneumocytes, and the interstitial stromal cells are fibroblasts or fibroblast-like cells. Recognition of its characteristic morphological appearance allows for its distinction from other benign lesions of the lung.

Adenoma↗
PubMed1990

Ultrastructure and neuron-specific enolase (NSE) immunohistochemistry of Merkel cells in normal toad epidermis, and following ablation of the pars distalis of the pituitary gland.

The present study was performed in order to re-examine the possible Merkel cell dependency upon the anterior pituitary by a combined ultrastructural and NSE immunohistochemical analysis of Merkel cells in normal toads, and following pars distalis ablation. Ultrastructurally, toad Merkel cells appeared similar to those in previous reports. They were found in normal as well as in operated toads, but with lower frequency in the latter group. By NSE immunohistochemistry, Merkel cells were seen in normal toads only. Even in individual, operated toads, in which Merkel cells were found with relative high frequency by electron microscopy, no NSE could be demonstrated immunohistochemically. It is discussed whether the amount of NSE present depends upon the physiological state of the Merkel cell and in some cells occurs in so low an amount that the NSE antigen cannot be detected by the immunocytochemical method applied. If it is so, the failure to demonstrate Merkel cells in the operated toads by means of the specific marker NSE may be interpreted as an inhibition of NSE expression following pars distalis ablation. This interpretation combined with the lower number of Merkel cells found ultrastructurally in operated toads support a previous indication of an influence of the anterior pituitary--directly or indirectly--upon toad Merkel cell function.

Animals↗