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PubMedDate not supplied

[Ultrastructural changes in the hemato-encephalic barrier of adult animals after acute hypoxic hypoxia].

The ultrastructure of the blood-brain barrier (BBB) was studied in different periods after the effect of acute hypoxic hypoxia. Local changes in the BBB ultrastructure indicating increased transport of blood plasma through certain areas of the vascular wall were seen already 24 hours after the hypoxia session. Four days later these changes were more marked and more diffuse. In 7 days the ultrastructure of the vessels and the surrounding brain tissue showed more significant changes. In later periods a tendency towards restoration of the BBB ultrastructure was revealed, which was also irregular in its course. The greater or lesser vulnerability of the different regions of the brain vessels may be determined both by the uneven decrease of their tonus and by the possible differences in the metabolic changes in the different areas of the brain vascular system under such conditions.

Acute Disease↗
PubMed1990

Effects of radiation on rabbit thyroid gland ultrastructure.

The ultrastructure of irradiated rabbit thyroid gland (0 Gy, as control, 4 Gy, 8 Gy, 12 Gy, 16 Gy and 20 Gy X-ray) is studied. The thyroid gland of the control group shows ultrastructural features similar to those described in other mammals. Modifications in follicular ultrastructure and interfollicular connective tissue ultrastructure as well as the presence of small thyroid follicles, probably neoformed, are found to be dose-dependent. Follicular epithelium varies from simple cuboidal to simple squamous, the latter being characteristic of the highest X-ray dose. Follicular cells show numerous cytoplasmic light vesicles and a very extensive rough endoplasmic reticulum consisting of vacuolated cisternae. Sloughed cells are present at 8 Gy. A well-developed interstitial glandular tissue consisting of extensive extracellular matrix, abundant collagen fibres and dilated, irregularly outlined capillaries are also present.

Animals↗
PubMed1986

Human thymocyte differentiation: an ultrastructural study using monoclonal antibodies and immunogold staining method.

The ultrastructural features of normal human thymocytes were analyzed at various stages of immunologic differentiation as defined by a panel of OKT monoclonal antibodies visualized by colloidal gold labelled antimouse IgG. The study shows that first stage thymocytes (OKT10+, OKT9+) have a typical morphology not found in more mature stages and describes the critical ultrastructural change which they undergo in becoming second stage thymocytes (OKT10+, OKT6+, OKT8+, OKT4+). No change in thymocyte fine morphology has been found in the progression from second to third stage (OKT10+, OKT3+, OKT8+ or OKT10+, OKT3+, OKT4+). Cells with ultrastructural features intermediate between those of the first and second stage have been found to react with monoclonal antibodies characterizing the first and the second stage. Ultrastructural similarity and homogeneity found in OKT8+ and OKT4+ thymic subpopulations suggests the acquisition by T lymphocytes of morphologic structures correlate with immunologic features previously found in peripheral blood T cell subpopulations to be a post-thymic process.

Antibodies, Monoclonal↗
PubMedDate not supplied

The use of a panel of monoclonal antibodies in ultrastructurally characterized small cell carcinomas of the lung.

In recent electron microscopic studies of 51 small cell carcinomas of the lung, the ultrastructural features of epithelial differentiation, particularly the presence of desmosomes, were associated with a tendency toward localized disease, clinical resectability and relatively long survival. Thirty-three of these cases were studied with a panel of monoclonal antibodies (B72.3, B1.1, AE1-AE3 and anti-Leu-7) directed against tumor-associated glycoprotein (TAG-72), carcinoembryonic antigen (CEA), cytokeratin and Leu-7 (an antigen common to natural killer cells and small cell lung carcinomas) to assess the correlation between the immunocytochemical and ultrastructural evidence of differentiation in tumors lacking differentiation at the light microscopic level. Of four small cell carcinomas with ultrastructural glandular differentiation, two were positive for CEA, three were positive for cytokeratin, and none were positive for TAG-72 and Leu-7. Of six tumors with ultrastructural squamous features, cytokeratin was expressed by three, CEA by one and TAG-72 and Leu-7 by none. Of the 23 classic oat cell carcinomas, cytokeratin was expressed by 14, Leu-7 by 3, CEA by 1 and TAG-72 by none. While the pattern of antigen expression did not predictably reflect the submicroscopic features, there was a significant association between keratin staining and extent of disease. The prospective use of similar antibody panels with both cellular and histologic material may therefore help to define clinically relevant categories of this biologically heterogeneous neoplasm.

Antibodies, Monoclonal↗
PubMed1989

Ultrastructure of monkey peripheral blood basophils stimulated to develop in vivo by recombinant human interleukin 3.

Ultrastructural and cytochemical studies of peripheral blood samples from a monkey continuously infused with recombinant human interleukin 3 were performed. Recombinant human interleukin 3 stimulated a delayed granulocytosis primarily characterized by numerous mature basophils and fewer eosinophils and neutrophils. Basophilic leukocytes were identified by ultrastructural analysis. They were found to be typical granulocytes with polylobed nuclei containing condensed chromatin and numerous cytoplasmic granules. Basophil secretory granules were filled with homogeneous dense contents and were larger than eosinophil and neutrophil secretory granules. Evidence of increased basophil production was accompanied by interleukin 3-associated activation morphologies. These included increased numbers of cytoplasmic and granule-associated vesicles, as are routinely present in a non-IgE-mediated basophil release reaction, termed piecemeal degranulation, and focal perigranular matrix swelling and granule membrane fusion which accompanies anaphylactic degranulation of basophils in other species. Monkey basophils were shown to have a different ultrastructural morphology than that published for monkey mast cells, but exhibited general morphologic criteria for the identification of circulating mature basophils in a number of species. Like human and guinea pig basophils, monkey basophils did not display endogenous peroxidase or peroxidatic activity in a cytochemical assay which simultaneously identified peroxidase-positive granules in neutrophils and eosinophils as well as in synthetic structures in eosinophils. In summary, these studies have identified monkey basophils in an in vivo recombinant human interleukin 3-stimulated model. Interleukin-3 induction of basophilia clearly allowed differentiation of activated mature basophils from eosinophils and neutrophils and mast cells in this species using ultrastructural morphologic criteria.

Animals↗
PubMed1989

[The ultrastructure of the ciliary epithelium in patients with the Zivert-Kartagener syndrome, bronchiectasis and cystic hypoplasia of the lungs].

Ultrastructure of the cilia of the bronchial epithelium was studied in 26 patients with Zivert-Kartagener syndrome, 12 patients with bronchiectasis and 10 patients with cystic lung hypoplasia. All changes of the cytolemma and cytoskeleton are found to be of a combined type. The degree of the bronchial inflammation was of the decisive influence on the state of the ciliary cells. Common features of the ultrastructural alterations are noted in the groups of patients compared. Ultrastructural defects characteristic for the patients with the Zivert-Kartagener triad were not found. It is concluded that all the ultrastructural defects of the ciliary epithelium were of the acquired character.

Biopsy↗
PubMed1989

[Pathogenesis of disorders of transparency of the optic media of the eye. III. Quantitative detection of copper in relation to the ultrastructure of the vitreous body in chalcosis].

The authors elaborated a new analytical micromethod for the detection of elements in morphologically investigated ultrastructures of the vitreous body. For the investigation of quantitative ultrastructural changes electron microanalysis (EMA) was used, combined with raster electron microscopy (REM). Using this method, the authors proved ultrastructural changes of the vitreous body by selective uptake of copper in the trabecular collagen fibres of the vitreous body in experimental chalcosis. From the results ensues that copper does not diffuse in the vitreous body in a homogeneous manner but aggregates in irregular agglomerations of precipitates and crystals. The different quantitative detection of copper in different parts of the same specimen is according to the authors due to the heterogeneous affinity of ultrastructural portions of the vitreous body for copper.

Animals↗
PubMed1989

The significance of ultrastructural features in acute myeloid leukemia: a study of 220 patients entered into the Medical Research Council's ninth acute myeloid leukemia trial.

Samples of peripheral blood or bone marrow obtained before treatment from 220 patients entered into the Medical Research Council's ninth acute myeloid leukemia (AML) trial were examined by electron microscopy. Several ultrastructural features showed strong correlations with each other, with variants of AML defined by the Hayhoe classification scheme, and with FAB type. However, no ultrastructural feature was found either uniquely in association with any other or specifically in any variant of AML. Each ultrastructural feature was tested for association with achievement of remission, remission duration, and survival time. Only Auer rods were associated with a high remission rate (p = 0.01), but even this association was not quite conventionally significant when the analysis was not quite conventionally significant when the analysis was stratified for age (p = 0.055). Shorter duration of remission was associated with cytoplasmic projections (p = 0.04 stratified for age). Overall survival was worse when convoluted or lobed nuclei were present but only when stratified for age and Hayhoe type (p = 0.04). The possibility of testing combinations of ultrastructural features for correlation with diagnosis or prognosis is discussed but would require data from more than the present 220 patients to be meaningful.

Bone Marrow↗
PubMed1985

Ultrastructural correlates of transmitter release in presynaptic areas of lamprey reticulospinal axons.

The ultrastructure of presynaptic areas of lamprey reticulospinal axons was studied before, during, and after periods of elevated transmitter release produced either by repetitive action potential activity or depolarization by elevated extracellular potassium. Controls for possible effects of these procedures per se were done by replacing extracellular Ca with Mg to block transmitter release. In some experiments the time course of ultrastructural changes during K depolarization and subsequent recovery were studied by fixing tissue samples at various times. Transmitter release produced by action potential activity (20/sec for 15 min) in the presence of extracellular Ca significantly and reversibly decreased the number of synaptic vesicles, the area occupied by the vesicles, and the density of synaptic vesicles. An unexpected finding was a reversible decrease in the length of the differentiated membrane during periods of increased transmitter release. Transmitter release significantly and reversibly increased the number of coated vesicles, expanded the presynaptic membrane, and increased the number of pleomorphic vesicles. K depolarization (50 mM K for 15 min) produced identical, reversible effects, except that the expansion of the presynaptic membrane, although significant, was relatively small and there was no change in the number of pleomorphic vesicles. Raising the temperature of the saline from 2 degrees C (K depolarization experiments) or 7 degrees C (action potential experiments) to 20 degrees C did not change the results qualitatively but did produce somewhat larger effects during stimulation and appeared to increase the speed of recovery. Action potential activity or K depolarization in control experiments with the Ca in the saline replaced by Mg had little or no effect on synaptic ultrastructure. Synaptic vesicles in lamprey reticulospinal axons never contacted the axonal membrane anywhere other than at the differentiated membrane. During periods of elevated transmitter release, although the absolute number of vesicles in contact with the differentiated membrane decreased, the percentage of total vesicles in contact with the differentiated membrane increased dramatically. This suggests that the differentiated membrane is the site of vesicle release and there is an active process of vesicle movement to this membrane. In the course of this work it was observed that presynaptic areas closer than approximately 2 mm to the site of axonal transection, regardless of the composition of the saline or the experimental conditions, showed ultrastructural changes typical of increased transmitter release.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Sprouts emerging from the dendrites of axotomized lamprey central neurons have axonlike ultrastructure.

We have examined the dendritic and axonal ultrastructure of intact anterior bulbar reticulospinal neurons (ABCs) in the CNS of the larval sea lamprey and compared it with that of the dendrites and neuritic sprouts from ABCs examined 2 months following axotomy. Dendrites and axons of intact ABCs are distinguishable from one another by several ultrastructural criteria: (1) the predominance of microtubules in the dendritic cytoskeleton and neurofilaments in that of the axon, (2) the exclusively postsynaptic status of the dendrites versus the presynaptic status of the axon, and (3) the presence of polyribosomes and large numbers of mitochondria in the dendrites and their respective absence and scarcity in the axon. The ultrastructure of axonal sprouts evoked by axotomy of ABCs 1-1.5 mm from their somata ("intermediate axotomy") in many ways resembled that of intact axons. Axonal sprouts were presynaptic to other neurons, and their cytoskeletons consisted mainly of neurofilaments. They also exhibited some features not seen in either axons or dendrites, such as numerous clusters of small vesicles that were not associated with synapses and, in some cases, close associations with glial elements. We also examined sprouts emerging from the dendrites of ABCs following axotomy within 500 microns of their somata ("close axotomy") and found that such "dendritic" sprouts closely resembled axonal sprouts; they possessed neurofilament-dominated cytoskeletons, were presynaptic to other neurons, and were often associated with glial elements. The dendrites of ABCs undergoing dendritic sprouting retained their normal gross morphology but possessed a mixture of "axonal" and "dendritic" ultrastructural characteristics, exhibiting neurofilament-dominated cytoskeletons while remaining entirely postsynaptic to other neurons. However, there were significantly fewer synapses on the dendrites of axotomized cells than were found on the dendrites of intact ABCs. We conclude that sprouts evoked by axotomy are intrinsically axonal in character whether they originate from the axon stump or from the dendritic tree. Our results also suggest that the materials necessary for axonal regeneration may displace elements of the dendritic cytoskeleton as they are transported through the dendrites to the emerging "dendritic" sprouts following close axotomy.

Animals↗
PubMed1985

[Ultrastructural characteristics of the histological forms of breast tumors].

Differences in ultrastructurally-differentiated and undifferentiated cells distribution were established in such non-invasive and invasive histological patterns of breast cancer as medullar carcinoma, mucinous, adenoid-cystic and lobular invasive cancer by means of electron microscopy. It was shown that a certain histological pattern is not necessarily matched by a relevant degree of ultrastructural differentiation of tumor cells. Tumor tissues of a similar histological pattern sometimes revealed different ratios of ultrastructurally-differentiated and undifferentiated cells, which may be responsible for the peculiarities in the clinical behavior of the said neoplasms. These data should be taken into account in establishing ultrastructural diagnosis as well as prognostic evaluation of the findings of electron microscopic examination in cases of non-invasive and certain invasive forms of breast tumors.

Adenocarcinoma, Mucinous↗
PubMed1985

Ultrastructural alterations in rats adrenal cortical cells produced by 4-aminopyrazolopyrimidine and ACTH administration.

The correlation between adrenal cortical steroid metabolism and ultrastructural alterations was studied in rat adrenal glands stimulated by 4-aminopyrazolopyrimidine (4-APP) and ACTH. Ultrastructural alterations were focused on the outer fasciculata (Outer zone) and inner fasciculata-reticularis (Inner zone) of the rat adrenal cortical cells. In 4-APP administered rats, the most striking ultrastructural alteration was noted in the characteristic tubular profiles of smooth endoplasmic reticulum, mainly of the Inner zone. In ACTH administered rats, proliferation of fine tubulo-vesicular profiles of smooth endoplasmic reticulum was frequently seen in intermitochondrial space in both the Outer and the Inner zones. On the other hand, by 4-APP plus ACTH administration, the most striking ultrastructural changes were detected in mitochondria, mainly of the Inner zone. These mitochondria had a highly electron dense matrix and protrusions or blebs of mitochondrial outer membrane were frequently observed. In contrast, no remarkable changes were detected in the Outer zone of the cortex, except a slight enlargement of the mitochondria. On the bases of our findings, it is strongly suggested that the Inner zone of the cortex after 4-APP plus ACTH administration, at least in part, probably corresponds to highly activated steroid synthesis and it is further, speculated that steroidogenesis in the adrenal cortical cells after 4-APP administration is partially impaired in mitochondrial 11 beta-hydroxylase system.

Adenine↗
PubMed1988

Ultrastructural alterations in the kidneys of Pekin ducks fed methylmercury.

Ultrastructural alterations in the kidneys of Pekin ducks were studied after subchronic exposure to methylmercury chloride. Twenty-four male and twenty-four female Pekin ducks, 12 weeks of age were fed 0.0 (control), 0.5, 5.0 and 15.0 parts per million of MeHgCl, mixed in a mash diet for 12 weeks. Birds were observed for clinical signs daily. Kidneys were fixed in situ by perfusion with 4% glutaraldehyde in 0.05 M phosphate buffer and routinely processed for electron microscopy. Only minor morphological changes were observed in the renal corpuscle of ducks in the 0.5 ppm group. The component cells of the renal corpuscle in the 5.0 and 15.0 ppm groups showed several ultrastructural alterations, including an increase in number and size of lysosomes and vacuoles in podocytes and mild vacuolation in mesangial cells. The juxtaglomerular cells of afferent arterioles had crystallized granules. No significant changes were observed in glomerular basement membrane thickness and width of podocyte pedicels. The proximal tubules of the 5.0 and 15.0 ppm groups showed some microvillar loss and an increase in the number and size of lipid droplets, vacuoles and lysosomal bodies. The distal tubular changes in the 5.0 and 15 ppm groups included electron lucency and vacuolation of cytoplasm as well as occasional mitochondrial swelling. The collecting ducts of 5.0 ppm and 15.0 ppm groups showed varying degrees of degenerative changes in both mucus secretory as well as absorptive cells. These results suggest that subchronic exposure of Pekin ducks to methylmercury chloride causes subtle ultrastructural changes in renal corpuscle and marked ultrastructural changes in proximal tubules and collecting ducts.

Animals↗
PubMed1987

[Ultrastructural changes in the cerebral cortex of the cat 30 to 60 minutes after anoxia].

The ultrastructural changes in the cat sensorimotor cortex during 30- to 60-minute recovery after a 2.5- to 6-minute anoxia have been studied. The most prominent changes were hypertrophy of Golgi apparatus, reorganization of the neuronal endoplasmic reticulum (including the formation of lamellar bodies), increase of the number of lysosomes within nerve cell bodies, formation of deep invaginations of the neuronal cytoplasm into the nucleus, intensification of endocytosis and phagocytosis in the dendrites, appearance of the ultrastructural heterogeneity of the synapses (from normal synapses to depleted ones), normalization of ultrastructure of the part of mitochondrial pool. Glycogen granules were revealed in glial cell processes. The ultrastructural changes after a 6-minute anoxia followed by a 30- to 60-minute recovery were more expressed than after a 2.5-minute one.

Animals↗
PubMed1986

An ultrastructural morphometric and immunohistochemical analysis of cutaneous lymphomas and benign lymphocytic infiltrates of skin. Useful criteria for diagnosis.

Our combined ultrastructural, immunohistochemical, histologic, and clinical studies over the past five years have allowed us to compile diagnostic criteria useful in the evaluation of cutaneous lymphomas. As a group, mycosis fungoides (MF) patients could be distinguished from those with benign disorders of skin using ultrastructural morphometry (mean form factor and perimeter values), but with some overlap between groups. Another approach, the ultrastructural histogram method, however, clearly separated MF patients from patients with chronic dermatitis. Immunohistochemistry was useful in distinguishing cases of cutaneous peripheral T-cell lymphoma from MF cases on the basis of the occurrence of "novel phenotypes." Neoplastic T-cell infiltrates of skin can usually be distinguished from benign polyclonal T-cell infiltrates by the presence of one T-cell subset to the exclusion of others. Patients with convoluted B-cell lymphomas could also be distinguished from MF patients using ultrastructural morphometric dual parameter analysis. The diagnostic complexity of several cutaneous T-cell lymphoma cases is illustrated. We have emphasized in this study the strength of combining quantitative electron microscopy, immunohistochemistry, and histology in the diagnostic workup of cutaneous lymphomas. This integrative approach may be necessary to assure a definitive diagnosis in difficult cases.

Adult↗
PubMed1986

Ultrastructure of hyaline cartilage. I. A comparative study of cartilage from different species and locations, using cryofixation, freeze-substitution and low-temperature embedding techniques.

Important progress in the cryofixation of tissues has recently been made with the introduction of a new technique which permits a great reduction in the rates of ice-crystal growth and nucleation by rapid freezing under a pressure of 2 100 bar. Tissue pieces up to 0.5 mm in thickness can now be processed at a freezing rate sufficient to prevent the formation of detectable ice crystals at the ultrastructural level. In the present investigation this technique, in combination with freeze substitution and low temperature embedding was applied for ultrastructural and immunocytochemical studies of hyaline cartilage. No extraction of matrix proteoglycans was observed during the substitution procedure, and there are good reasons to believe that in preparations obtained by this technique the native state of the matrix components is preserved, since, for example, the collapse temperature of the macromolecules is not exceeded. Furthermore, no chemical fixatives or cryoprotectants are required. Ultrastructural differences in the hyaline cartilage of the growth-plate between normal rats and mice were observed, and also differences between cartilage at different locations, such as tracheal cartilage and growth-plate. Using this technique, further comparative ultrastructural studies enable us to obtain information about the macromolecular organisation of cartilage matrix under various normal and pathological conditions in vivo. In addition, using monoclonal antibodies to the main macromolecules of the matrix, it was found that this technique not only provides excellent tissue preservation but is also well suited for immunocytochemistry with colloidal gold as a marker.

Animals↗
PubMed1987

[Malignant paraganglioma of the duodenum. Immunohistochemical and ultrastructural study of a case].

Paragangliomas of the duodenum are rare. Only 40 cases, most of them corresponding to benign tumours, have been published. In this study, we report a malignant paraganglioma of the duodenum with lymph node metastasis occurring in a 73 year old woman. The essential clinical manifestations which brought the patient to surgery were abdominal pain, melaena and anemia. The surgical specimen was investigated histologically, immunohistochemically and ultrastructurally. The tumour was composed of three types of cells: epithelial, gangliocytic and spindle shaped mesenchymal cells. The first contained ultrastructurally intracytoplasmic granules bound with double membranes; they stained with monoclonal antibodies against chromogranin. Gangliocytic cells stained with monoclonal N.S.E. antibodies and the spindle cells stained with S 100 protein. The spindle cells displayed ultrastructurally glial cell characteristics, containing micro-filaments of glial type. These immunological and ultrastructural features argued in favor of the neuroendocrine cell origin of this paraganglioma.

Aged↗
PubMed1987

[Ultrastructural and clinical study on neuroblastoma].

Ultrastructures of 11 cases of neuroblastoma and ganglioneuroblastoma were observed. Ultrastructurally, the neuroblastoma could be classified into four types: immature, poorly differentiated, differentiated and ganglioneural cell. Neurosecretory granules (NSG) of round or oval shapes with various diameters in the tumor cells and neural processes were observed. The presence of NSG in the tumor tissue is one of the pathognomic features for neuroblastoma. Comparing and study of the relation between the ultrastructural findings and the excretory patterns of the urinary catecholamine as well as the prognosis, it was shown that the tumor of the differentiated type and the presence of abundant NSG lead to a good prognosis. Some slight differences in ultrastructure were found in neuroblastoma specimens from children of various ages. Infants under 18 months had a longer survival time, which is related to the differentiation and other features of the tumor cells.

Age Factors↗