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At least 19 recordsLinked to original sources
PubMed1968

Ultrastructural bases for metabolically linked mechanical activity in mitochondria. II. Electron transport-linked ultrastructural transformations in mitochondria.

Isolated mitochondria are capable of undergoing dramatic reversible ultrastructural transformations between a condensed and an orthodox conformation. These two conformations are the extremes in ultrastructural organization between which structually and functionally intact mitochondria transform during reversible respiratory cycles. It has been found that electron transport is required for the condensed-to-orthodox ultrastructural transformation which occurs in mitochondria under State IV conditions, i.e., under conditions in which exogenous substrate is present and ADP is deficient. Inhibition of State IV electron transport at the cyanide-, antimycin A-, or Amytal-sensitive sites in the respiratory chain results in inhibition of this transformation. Resumption of electron transport in initially inhibited mitochondrial systems, initiated by channeling electrons through pathways which bypass the inhibited sites, results in resumption of the ultrastructural transformation. The condensed-to-orthodox transformation is DNP insensitive and, therefore, does not require participation of the coupling enzymes of the energy-transfer pathway. It is concluded that this ultrastructural transformation is manifest by the conversion of the chemical energy of electron transport directly into mechanical work. The reversed ultrastructural transformation, i.e., orthodox-to-condensed, which occurs during ADP-activated State III electron transport, is inhibited by DNP and parallels suppression of acceptor control and oxidative phosphorylation. Mechanochemical ultrastructural transformation as a basis for energy transfer in mitochondria is considered with respect to the results presented.

Adenine Nucleotides↗
PubMed2001

Extraskeletal myxoid chondrosarcoma: a light microscopic, immunohistochemical, ultrastructural and immuno-ultrastructural study indicating neuroendocrine differentiation.

AIMS: Extraskeletal myxoid chondrosarcoma is a rare low-grade soft-tissue sarcoma with locally aggressive and metastasizing potential. Extraskeletal myxoid chondrosarcoma has distinctive clinical, light microscopic, immunophenotypic, cytogenetic and ultrastructural features. Evidence that extraskeletal myxoid chondrosarcoma often shows neuroendocrine features was first provided by Chhieng et al. on the basis of an immunohistochemical and ultrastructural study of seven cases. Our study aims to further confirm by immunohistochemistry and ultrastructural studies, including immunoelectron microscopy, that extraskeletal myxoid chondrosarcoma indeed may show neuroendocrine differentiation. METHODS AND RESULTS: Fifteen cases of extraskeletal myxoid chondrosarcoma and seven control cases of skeletal chondrosarcomas were studied. Extensive immunohistochemical analysis was performed in all cases and ultrastructural studies were done in 11 extraskeletal myxoid chondrosarcomas and three skeletal chondrosarcomas. Immunoelectron microscopy was performed on one case each of extraskeletal myxoid chondrosarcoma and skeletal chondrosarcoma. Extraskeletal myxoid chondrosarcomas expressed neuron-specific enolase (100%), synaptophysin (87%), S100 (50%), PGP 9.5 (40%), and epithelial membrane antigen (25%). Co-expression of synaptophysin and PGP 9.5 was observed in six tumours. Skeletal chondrosarcomas showed expression of S100 protein, vimentin and neuron-specific enolase in all cases. Synaptophysin, chromogranin and PGP 9.5 were not expressed in any skeletal chondrosarcoma case. Ultrastructurally, extraskeletal myxoid chondrosarcoma was characterized by distinct cords of cells immersed in a glycosaminoglycan-rich matrix. The cells were rich in mitochondria, had well-developed Golgi apparatus and there were numerous smooth vesicles. In three cases there were easily found 140-180 nm diameter membrane-bound dense-core granules in cell bodies and in processes, unrelated to the Golgi, compatible with neurosecretory granules. Fewer such granules were present in the remaining extraskeletal myxoid chondrosarcoma cases, three of which also contained intracisternal tubules typical of extraskeletal myxoid chondrosarcoma. The skeletal chondrosarcomas had scalloped cell surfaces, prominent rough endoplasmic reticulum focally distended with secretory product, and lacked neurosecretory granules. Intermediate filaments were prominent in both extraskeletal myxoid chondrosarcoma and skeletal chondrosarcomas. Immunoelectron microscopy showed synaptophysin expression in the extraskeletal myxoid chondrosarcoma but not in the skeletal chondrosarcoma case. CONCLUSIONS: This study confirms that a substantial proportion of extraskeletal myxoid chondrosarcomas show immunophenotypic and/or ultrastructural evidence of neuroendocrine differentiation, and are unlikely to be related to conventional skeletal chondrosarcomas.

Adult↗
PubMed1966

Ultrastructural bases for metabolically linked mechanical activity in mitochondria. I. Reversible ultrastructural changes with change in metabolic steady state in isolated liver mitochondria.

By means of a new "quick-sampling" method, micropellets of mouse liver mitochondria were rapidly prepared for electron microscopy during the recording of steady state metabolism. Reversible ultrastructural changes were found to accompany change in metabolic steady states. The most dramatic reversible ultrastructural change occurs when ADP is added to systems in which only phosphate acceptor is deficient, i.e., during the State IV to State III transition as defined by Chance and Williams. After 15 min in State IV, mitochondria display an "orthodox" ultrastructural appearance as is usually observed after fixation within intact tissue. On transition to State III, a dramatic change in the manner of folding of the inner membrane takes place. In addition, the electron opacity of the matrix increases as the volume of the matrix decreases, but total mitochondrial volume does not appear to change during this transition. This conformation is called "condensed." Isolated mitochondria were found to oscillate between the orthodox and condensed conformations during reversible transitions between State III and State IV. Various significant ultrastructural changes in mitochondria also occur during transitions in other functional states, e.g., when substrate or substrate and acceptor is made limiting. Internal structural flexibility is discussed with respect to structural and functional integrity of isolated mitochondria. Reversible changes in the manner of folding of the inner membrane and in the manner of packing of small granules in the matrix as respiration is activated by ADP represent an ultrastructural basis for metabolically linked mechanical activity in tightly coupled mitochondria.

Adenine Nucleotides↗
PubMed1987

De novo neuromuscular junction formation on human muscle fibres cultured in monolayer and innervated by foetal rat spinal cord: ultrastructural and ultrastructural--cytochemical studies.

Ultrastructural features of neuromuscular junction formation and transverse tubule development were studied utilizing a newly developed model in which human muscle fibres cultured in monolayer are innervated by foetal rat spinal cord with dorsal root ganglia attached. At early innervation (7-10 days), when distinct 'boutons' are contacting muscle fibres, the contacts of nerve terminals with the muscle fibres are, ultrastructurally, superficial and unorganized, and there is no basal lamina-like material between nerve terminals and muscle fibres. A bouton consists, ultrastructurally, of a cluster of small nerve terminals contacting the muscle fibre. At 2-3 weeks of innervation, shallow 'beds' are formed on the muscle fibre just beneath nerve terminals, and occasionally there are irregular and miniscule fragments of basal lamina-like material in the cleft. There is no Schwann cell apposing the nerve terminal at this stage of innervation. After 4-5 weeks of innervation there is more definite basal lamina material in the cleft and suggestive postsynaptic plasmalemmal densities and invaginations. However, there is no Schwann cell apposing the nerve terminal at this stage. At 6-8 weeks of innervation, deep postsynaptic folds are present, a Schwann cell apposes the nerve terminal, and basal lamina surrounds the entire muscle fibre. At all four stages of innervation examined, ultrastructural cytochemistry of alpha-bungarotoxin binding reveals that nicotinic ACh receptors are located exclusively at the neuromuscular junctions. After 1-2 weeks of innervation, very few lanthanum-positive transverse tubules are observed and only in close proximity to the surface membrane. After 3 weeks of innervation, more lanthanum-positive tubules are present, and they are located deeper within the muscle fibre. Five weeks after innervation, somewhat more elaborated tubules (but no lateral sacs) appear, and honeycomb structures are often present. After 6-7 weeks of innervation the tubular system is very elaborate and lateral sacs are present. Hence, this study describes consecutive stages of the formation of neuromuscular junctions and transverse tubules in innervated cultured human muscle, and provides an important basis to which similar studies related to the diseased human muscle can be compared.

Animals↗
PubMed1977

Malignant histiocytosis with chronic course. Ultrastructural and ultrastructural cytochemical studies.

Four cases of malignant histiocytosis with leukemic manifestations and chronic course were reported. Light microscopic, ultrastructural and ultrastructural cytochemical details of these atypical cells were demonstrated. Ultrastructurally these cells resembled hairy cells most closely among the known varieties of leukemic cells. However, ribosome-lamella complexes were not found and some atypical cells had a few short cytoplasmic projections. In addition, tartrate-resistant acid phosphatase was absent from these cells. We speculate that this leukemic reticuloendotheliosis with a chronic course seen in Japan seems to be analogous to malignant histiocytosis with massive splenomegaly reported by Vardiman et al.

Acid Phosphatase↗
PubMed1976

Studies on the ultrastructure, histochemistry and cytochemistry of the uninfected digestive gland of Bithynia tentaculata (Mollusca: Gastropoda) and on the ultrastructure of this host organ in snails infected with larval digeneans.

The structure and function of the digestive gland of the gastropod mollusc, Bithynia tentaculata, was investigated using ultrastructural, histochemical, and cytochemical techniques. The digestive gland was shown to be composed of two main cell types, the "digestive" cells and "secretory" cells. The digestive cells appeared to be concerned with the absorption and digestion of nutrients, while secretory cells produced digestive enzymes and calcareous concretions. Undifferentiated cells were scattered between these two main cell types. The pathological effects of larval digeneans on the digestive gland were also investigated, at the ultrastructural level. In such infected snails the digestive gland appeared to be degenerating. The significance of this tissue destruction was briefly discussed.

Acid Phosphatase↗
PubMedDate not supplied

An ultrastructural, immunohistochemical, and cytogenetical study of a monophasic pulmonary synovial sarcoma: implications of the frequent ultrastructure of oligocilia and concentric membranous bodies with positive immunostaining for VS38c and MEF2.

A rare case of a monophasic pulmonary synovial sarcoma is reported. A 44-year-old Japanese man underwent lower lobectomy for a nodular mass in his right lung. Immunohistochemical study of the excised primitive spindle cell sarcoma revealed occasional positive stains by hitherto reported antigens of S-100, cytokeratin 7, high molecular weight cytokeratin (34 beta E12), pankeratin (AE1/AE3), and EMA, which were helpful for the differential diagnosis of other spindle cell sarcomas. Furthermore, positive immunostains for MEF2, VS38c (plasma cell antigen), and bcl-2 were rather significant findings in the present case. The definitive evidence that molecular genetic analysis showed a clonal single electrophoretic band of SYT-SSX mutated chimera gene was conclusive for the pathological diagnosis. The implications of the frequently seen ultrastructure of oligocilia and concentric membranous bodies with positive stains for VS38c and MEF2 are discussed. In the difficult pathological diagnosis of a rare and undifferentiated type of sarcoma with unusual clinicopathological features generated at an unusual site, comprehensive ultrastructural, immunohistochemical, and cytogenetic studies will lead to the correct pathological diagnosis and elucidate the detailed characteristics of the tumor.

Adult↗
PubMed1965

Contractility and ultrastructure in glycerol--extracted muscle fibers. II. Ultrastructure in resting and shortened fibers.

Glycerol-extracted rabbit psoas muscle fibers were examined by electron microscopy both before and after ATP-induced isotonic shortening. Ultrastructural changes were correlated with the initial sarcomere length and the degree of shortening. The ultrastructural appearance of the resting fiber at rest length was identical with that described by H. E. Huxley and Hanson. At sarcomere lengths greater than 3.7 to 3.8 micro, the A and I filaments were detached and separated by a gap. The presence of "gap" filaments was confirmed, and evidence is presented which indicates that these filaments form connections between the ends of the A and I filaments. Shortening from initial sarcomere lengths at which the filaments overlapped took place through sliding of the filaments. If shortening was initiated from sarcomere lengths at which there was a gap, a narrowing of the I band was brought about by a curling of the I filaments at the boundary between the A and I bands. No evidence could be found that the I filaments moved into the A band.

Animals↗
PubMed1976

Biogenesis of mitochondrial membranes in Neurospora crassa during cellular differentiation: ultrastructural changes accompanying differentiation.

The ultrastructural characteristics of Neurospora cells during dedifferentiation and redifferentiation of conidiospores into vegetative cells have been determined. This germination process occurs between 2 and 5 h after inoculation; by 3-5 h, approximately 50% of the cells have germinated. The cells enter the exponential phase of dry-weight gain between 4 and 5 h after inoculation. Several unusual structures are observed in Neurospora cells during germination. Whorled structures are frequently seen in the cytoplasm during germination, and occasionally at other times. They appear to be derived from the cytoplasmic membrane. Whorled structures of different appearance were observed in the mitochondria between 2 and 4 h after inoculation. Their number was related to the level of metabolizable carbohydrate, and was higher in 15% glucose-than in 2% sucrose-supplemented medium, and very low in medium containing 15% mannitol, or 2% sucrose+13% 2-deoxyglucose, or no added carbohydrate. The mitochondrial inclusions were osmiophilic and could be removed by treatment with 90% aqueous acetone in the cold, indicating that they were composed at least in part of lipid. The strong dependence of the number of mitochondrial inclusions on time and on carbohydrate supplementation, suggests that there is a physiological basis for these structures and that they reflect changes occurring in the mitochondria at times significant to cellular differentiation.

Carbohydrate Metabolism↗
PubMed1976

Herpes gestationis. Ultrastructure and ultrastructural localization of in vivo-bound complement.

Ultrastructural localization of C3 deposition in the skin of two patients with herpes gestationis was determined by using a peroxidase-antiperoxidase multistep technique. The tissue preparations can be stored for long periods of time and identical sections may be used for light and electron microscopic examination. The reaction products were seen throughout the entire lamina lucida and the basal cell plasma membrane appeared to be accentuated. The most remarkable ultrastructural changes in normal-appearing skin were the destruction of the basal cell membranes on the dermal side, localized cytoplasmic dissolution, and intracellular edema unaccompanied by inflammatory cells. Early, nonvesicular lesions showed basal cell degeneration and dermal inflammatory cells. Necrosis and loss of basal cells occurred in the next stage which resulted in microvesicles in which collagen or a well-preserved basal lamina formed the vesicle base. In the later blister stage, the basal lamina was usually lost. It is suggested that damage of basal cell membranes on their dermal side leads to the destruction of basal cells with the subsequent protrusion of epidermal and junctional substances into the dermis. This may result in inflammatory cell infiltration and blister formation.

Complement C3↗
PubMed1981

[Ultrastructure, metabolism and function of white blood cells during the development of an immune response and exposure to glucocorticoids. III. Effect of immunization on the number and ultrastructure of rabbit bone marrow cells].

The characteristic features of the early period after the immunization of rabbits with bovine serum albumin are the decreased content of ripe neutrophil forms, the increased numbers of eosinophils and basophils, as well as changes in the ultrastructure of granulocytes in the bone marrow. The destruction of the primary and secondary granules, vacuolization and an increase in acidic phosphatase activity can be observed in neutrophils. Each stage of immunogenesis has its characteristic ratio of various kinds of lymphocytes. In 14 days an increase in the number of lymphocyte-like mononuclear cells occurs. In their ultrastructure these cells are similar to the hypothetical colony-forming cells of the bone marrow in mice.

Acid Phosphatase↗
PubMed1992

Collagen composition and ultrastructure of the so-called amianthoid fibres in palisaded myofibroblastoma. Ultrastructural and immunohistochemical study.

A very prominent feature of the recently described intranodal palisaded myofibroblastoma is the occurrence of stellate crystalline extracellular deposits known as 'amianthoid fibres', and thought to represent abnormally thick collagen fibrils. We showed at the ultrastructural level that these deposits are composed of fibrils with the periodicity and width typical of normal native collagen. Using antibodies directed against various extracellular components, we have determined that these structures contain type I and III collagens. Our results indicate that the crystalloid deposits in intranodal palisaded myofibroblastoma called 'amianthoid fibres' do not contain giant collagen fibrils widely regarded as characteristic of the morphological concept 'amianthoid' in other locations.

Cartilage↗
PubMed1982

Hepatic ultrastructure in leprechaunism. Hepatic ultrastructural evidence suggesting a syndrome with defective hepatic glucose release.

Leprechaunism is a congenital syndrome with characteristic habitus and facies, with fasting hypoglycemia and hyperinsulinism. In response to a glucose challenge there is prolonged severe hyperglycemia with an increased hyperinsulinemia. Our studies on such a patient showed a normal response of the serum glucose to glucagon stimulation in the fed state but no response in the postabsorptive state. Ultrastructural studies on the hepatocytes demonstrated that a lack of hepatic glycogen was not responsible for the biochemical features, since there was abundant normal beta-glycogen in both the fed and fasting state, the granules being smaller in the fasted state. We speculate that carbohydrate intolerance in leprechaunism may be due to a relative insulin resistance of cell receptors in the fed state. Reactive hyperinsulinemia persisting into the postabsorptive phase appears to antagonize the usual glycogenolytic response to glucagon during fasting, resulting in hypoglycemia despite the presence of large hepatic glycogen stores.

Child, Preschool↗
PubMed1984

Ultrastructural localization of secretin in endocrine cells of the dog duodenum by the immunogold technique. Comparison with ultrastructurally characterized S cells of various mammals.

Secretin has been localized by the immunogold technique in endocrine cells of the dog duodenum--previously described as "K cells"--characterized by secretory granules with double structure consisting of a secretin-containing osmiophilic core surrounded by an argyrophil halo. Granules resembling those of dog secretin cells were also found in some ultrastructurally characterized S cells of the cat, pig, rat and rabbit duodenum, thus confirming in these species the identification of S cells with secretin cells. Conversely, the cells previously described as "S cells" in the dog lacked secretin immunoreactivity.

Animals↗
PubMed1990

Differing microvasculature in the two major types of gastric carcinoma: a conventional, ultrastructural and ultrastructural immunolocalization study of von Willebrand factor.

The microvasculature of the stroma of human gastric carcinoma was studied by immuno-electron microscopy for factor VIII/von Willebrand factor (vWF) and conventional electron microscopy. In differentiated type (intestinal) gastric carcinoma (9 cases), capillaries were distributed more densely around carcinoma cell nests. vWF was localized in endothelial cells and neighbouring stroma. Ultrastructurally, capillary endothelial cells showed considerable hypertrophic changes with well-developed rough endoplasmic reticulum (rER). vWF was localized in well-developed rER, granules, Weibel-Palade bodies (WPB), in the vascular lumen as clusters, and diffusely deposited in the subendothelium. This indicates that endothelial cells in this group are transformed into a state of active protein production. In undifferentiated type (diffuse) gastric carcinoma (12 cases), capillaries were uniformly distributed and endothelial hypertrophic changes were less remarkable. vWF was localized in WPB, scanty rER and subendothelial matrix. Solid capillary buds were observed in both types; they were composed of a solid strand of endothelial cells without a visible lumen. Our results reveal that the microvasculature in tumour stroma differs significantly according to its histological type.

Capillaries↗
PubMed2005

Spermatozoa ultrastructure in Sciaenidae and Polynemidae (Teleostei:Perciformes) with some consideration on Percoidei spermatozoa ultrastructure.

Spermatozoa ultrastructure was studied in five marines (Paralonchurus brasiliensis, Larimus breviceps, Cynoscion striatus, Micropogonias furnieri, Menticirrhus americanus, Umbrina coroides, Stellifer rastrifer), and one freshwater (Plagioscion squamosissimus) species of Sciaenidae and one species of Polynemidae (Polydactylus virginicus). The investigation revealed that, in all species, spermatozoa display a round head, a nucleus containing highly condensed, filamentous chromatin clusters, no acrosome, a short midpiece with a short cytoplasmic channel, and a flagellum showing the classic axoneme structure (9+2) and short irregular lateral fins. In Sciaenidae, the spermatozoa are type II, the flagellar axis is parallel to the nucleus, the lateral nuclear fossa is double arched, the centriolar complex is outside the nuclear fossa, the proximal centriole is anterior and perpendicular to the distal centriole, and no more than ten spherical (marine species) or elongate (freshwater species) mitochondria are observed. Polynemidae spermatozoa are of the intermediate type with the flagellar axis eccentric to the hemi-arc-shaped nucleus, and exhibit no nuclear fossa, the centriolar complex close to the upper nuclear end, the proximal centriole lateral and oblique to the distal centriole, and one large ring-shaped mitocondrion. The data available show that no characteristic is exclusively found in the spermatozoa of members of the Sciaenidae family when compared to other Percoidei with type II spermatozoa. However, three characteristics were exclusively found in Polynemidae: (1) the hemi-arched nucleus; the positioning of the centrioles; and (2) the ring-shaped mitocondrion. The interrelationships between Sciaenidae and Polynemidae as well as between these two families and other Percoidei are herein discussed.

Acrosome↗
PubMed1980

Ultrastructural and biochemical studies of the brain and other organs in rat after chronic ethanol administration. III. Influence of ethanol intoxication on oxidative phosphorylation of the rat brain mitochondria with ultrastructural and morphometric evaluation of mitochondrial fraction).

The effect of chronic ethanol intoxication on oxidative phosphorylation in the rat brain mitochondrial fraction was examined. Moreover, electron microscopy was used to verify the quantitative composition of the fraction and for examination of ultrastructural changes in the mitochondria. The experiments were carried out with 60 rats receiving, beside the normal diet, ethyl alcohol according to a modified RATCLIFFE model. In isolated rat brain mitochondria the NAD-dependent oxidation of substrates (glutamate + malate) was decreased. The phosphorylation index ADP/0 and the respiratory control ratio (RCR) in rat brain mitochondria from ethanol-treated rats were unchanged in the presence of both succinate and glutamate + malate. Chronic ethanol feeding did not induce any changes of succinate dehydrogenase and cytochrome oxidase activities in solubilised mitochondria fractions of rat brain. Electron microscopy studies revealed that mitochondria from control animals retained their outer and inner membranes, whereas those from rats given ethanol were almost always swollen and some were disrupted. In mitochondrial fractions isolated from ethanol-intoxicated rats an increase was observed of contaminating elements i.e. axons and synaptosomes of various sizes. It should be stressed that the mitochondria located inside synaptosomes and axons were unchanged. The composition of the fractions was quantitatively evaluated and confirmed the diminution of "free" mitochondria in the experimental fractions in favour of "bound" mitochondria which mainly occurred in the synaptosomes with preserved metabolic activity. On the basis of electron microscopy studies it could be suggested that ethanol intoxication causes the damage of some mitochondria, which become more sensitive to mechanical destruction during isolation procedure, and they do not sediment together with the fraction of normal ones. The absence of "free" mitochondria in pellets explains the spurious lack of disturbances in the energy metabolism of brain mitochondria after chronic ethanol intoxication.

Adenosine Diphosphate↗
PubMedDate not supplied

Ultrastructural cytochemical and ultrastructural morphological differences between human multinucleated giant cells elicited by wear particles from hip prostheses and artificial ligaments at the knee.

The authors investigated the ultrastructural cytochemical features of multinucleated and mononuclear cells in periprosthetic tissues associated with bone resorption (osteolysis) and those in tissues adjoining failed artificial ligaments having no relation to bone resorption. Clinical specimens of granulation tissue of each type, respectively numbering 4 and 3, were stained for tartrate-resistant acid phosphatase (TRAP) reactions and examined by light and electron microscopy. Both periprosthetic granulation tissues and those adjoining artificial ligaments contained TRAP-positive multinucleated and mononuclear cells. Near joint prostheses, multinucleated cells, including some giant cells, showed TRAP activity and cytoplasmic features resembling osteoclasts, while others had features consistent with foreign-body giant cells, and still others showed degenerative changes. Near artificial ligaments, TRAP-positive multinucleated cells lacked osteoclastic features. At both sites, TRAP-positive multinucleated cells had phagocytised wear particles. TRAP-positive mononuclear cells at both sites also showed phagocytic cytoplasmic features, but not osteoclastic cytoplasmic features. Human mononuclear phagocytes and multinucleated giant cells induced by wear particles possess TRAP activity. Those multinucleated giant cells at sites of osteolysis developed osteoclastic cytoplasmic features and have a phagocytic function.

Acid Phosphatase↗