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PubMed1986

[Ultrastructure of large granule-containing lymphocytes possessing natural killer activity].

By means of light and electron microscopy, ultrastructural cytochemistry and immune cytochemistry methods, contents and ultrastructure of large granule-containing lymphocytes (LGL) have been studied in human blood--this is cell population possessing natural killer and, partly, antibody-depending cytotoxicity. The LGL concentrates are isolated from blood applying successive physical-chemical methods, differential centrifugation in the density gradient of pack-phycoll and percoll included. Separate LGL populations are marked by means of rosette-forming reaction with sheep erythrocytes and monoclonal antibodies OKT4 and OKT8. Relative and absolute amount of the LGL in 1 1 of blood is 5.4 +/- 0.5% and 0.319 +/- 0.28 X 10(9), respectively. The LGL ultrastructure is characterized with a low nuclear-cytoplasmic ratio, with presence of osmiophilic (azurophilic) granules in cytoplasm and specific parallel-tubular structures, with a well developed Golgi complex, an essential number of mitochondria, vesicles with smooth wall and vacuoles, as well as multivesicular bodies and Gallo bodies. The LGL subpopulations, expressing various membrane antigens (E+, E-, OKT8+, OKT8-) differ in their ultrastructure, that is evidently stipulated by the degree of their differentiation and their function.

Antigens, Surface↗
PubMed1986

[Ultrastructural study of 36 lymph node sites of Hodgkin's disease].

The authors report their ultrastructural findings of 36 involved lymph-nodes in Hodgkin's disease (HD), before any treatment. More than 400 tumour cells were studied. An analytical study was carried out on the different aspects presented by the nuclei (uni or multi-lobated); the nucleoli (compact, reticulate or dispersed); and the cytoplasm (immunoblastic, complex, intermediate). No cellular structure evoking phagocytic activity with digestion, and consequently an eventual histiomonocytic origin, could be detected even on serial sections. The presence of lipid inclusions, sometimes of glycogen, as well as certain peculiar structures are described and discussed. The ultrastructural aspects could be easily correlated with the different types of tumour cell described in HD using light microscopy. The various kinds of cells which could could be detected in the same lymph node, may correspond to a real tumour cell lineage, consisting, firstly, of a cell of immunoblastic type with a mono- or bilobated nucleus, then an intermediate type with a bilobated or multisegmented nucleus, and finally a complex cell type with a multisegmented nucleus. The lacunar cells are characterised by a fragile hyaloplasm, without cellular organelles at their periphery, these being concentrated around the nucleus. This special organisation explains the aspects observed in light microscopy. However, no explanation could be offered to understand this particular aspect of the cytoplasm. The ultrastructural characteristics of the Reed-Sternberg cells and their variants did not allow a precise cellular origin to be proposed. The absence of phagolysosomes pleads against a histiocytic origin. However their similarity of the interdigitated reticular cells did not seem sufficient to propose this origin. The likeliness of the cytoplasm of cells with mono- or bilobated nuclei with that of immunoblasts, constitutes the most interesting morphological feature. This fact, associated with the appearance of immunoblasts similar to Reed-Sternberg cells of infectious mononucleosis, suggests a lymphoid origin. The study of the reactive cells around the tumor cells did not allow any consequences to be drawn. One could simply note that the Reed-Sternberg cells and their variants were surrounded by lymphocytes, forming a kind of crown. No etiological agent could be detected. These data are compared to those of other publications, and discussed. This ultrastructural study, therefore, does not offer the solution to most of the questions which still remain to be answered as to the origin of the Reed-Sternberg cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Biopsy↗
PubMed1986

Coronary artery ligation and reperfusion in alloxan-diabetic rabbits: ultrastructural and haemodynamic changes.

The effects of left circumflex coronary artery occlusion (40 min) and subsequent reperfusion (60 min) on haemodynamics and myocardial ultrastructure were investigated in control and 10-week alloxan-diabetic rabbits. Before ligation, significant ultrastructural abnormalities, including mitochondrial swelling, disruption of cristae and deposition of lipids, were observed in hearts of diabetic animals. Occlusion of the coronary artery caused further worsening of the ultrastructural changes, including increased swelling and fragmentation of mitochondria, clumping and margination of nuclear chromatin and glycogen depletion in both control and diabetic animals. Following reperfusion, the ultrastructural alterations became even more marked, as characterized by disruption of mitochondria, hypercontraction of myofibrils and the presence of numerous amorphous electron-dense bodies. Paralleling these myocardial structural changes which were more prominent in the diabetic animals was a progressive worsening of haemodynamics, an increased incidence of arrhythmias (especially ventricular fibrillation) and cardiogenic shock in diabetic animals undergoing coronary artery ligation and reperfusion. Our studies indicate that reperfusion of the ischaemic diabetic myocardium accelerates tissue damage and is more detrimental than reperfusion in control animals.

Animals↗
PubMedDate not supplied

Ultrastructure of normal epithelial cells in Papanicolaou-stained cervical smears. An application of a modified open-face embedding technique for transmission electron microscopy.

The results of an open-face embedding technique applied to Papanicolaou-stained uterine cervical smears are presented. By this technique, cells are smeared on a plastic sheet, fixed in 1.5% buffered glutaraldehyde and stained by the Papanicolaou method; areas of special interest are then selected by light microscopy for electron microscopic observations. Thus, a comparison is possible between the light microscopic characteristics of cells in smear preparations and their ultrastructural counterparts. The good ultrastructural preservation allowed detailed study of nuclei and cytoplasm. The endocervical cells had intact nuclei with nuclear envelope, Golgi apparatus, well-preserved mitochondria and two types of secretory material. The superficial and intermediate squamous cells showed loss of desmosomes; dense, fine cytoplasmic fibrils; small, fatty droplets; and degenerated nuclei with loss of the nuclear envelope. Compared with ultrastructural studies on cervical tissues, the intermediate cells in cervical smears were more degenerated, presumably because predominantly degenerated intermediate cells exfoliate. This study indicates that the light microscopic impression of the nuclear appearance is misleading: in the routine smear the nuclei of superficial and intermediate cells may look "intact" and "well preserved" whereas ultrastructurally the nuclei are degenerated.

Cytological Techniques↗
PubMed1985

The effects of colchicine on the ultrastructure of the dental epithelium and odontoblasts of teleost tooth buds.

Secretory granule ultrastructure of teleost inner dental epithelial (IDE) cells has been reported to be similar to procollagen granules of other cells synthesizing collagen. This study describes the ultrastructure of secretory products in odontogenic cells during enameloid matrix formation in cichlids after inhibition of granule secretion with colchicine. Thirty-six fish were injected with 0.1 mg colchicine, then three were killed first at 2-hr intervals for 12 hr, then daily for 5 days. Tooth buds were processed for transmission electron microscopy, and ultrastructural alterations were assessed for each post-injection interval. Four hours post-injection, IDE cells contained increased numbers of secretory granules, lightly stained granules, dilated cisternae of the granular endoplasmic reticulum, and intercellular amorphous material. After 6 hr, the IDE intercellular amorphous material additionally contained electron dense deposits, and after 8 hr, the intercellular material had fibers similar in appearance to enameloid collagen. No ultrastructural changes were detected in odontoblasts that were in close proximity to the enameloid matrix. Only odontoblasts synthesizing predentin were affected by colchicine, and the observed alterations were similar to those seen in IDE cells. It is concluded that IDE cells synthesize and secrete ectodermal enameloid matrix collagen.

Amelogenesis↗
PubMed1985

[Changes in the ultrastructure of the myocardium after fibrillation and in the process of autolysis].

Ultrastructure of the myocardium in the experiment was studied just after the heart ventricular fibrillation and 3 h after the animal death; the results were compared to those obtained by studying ultrastructure of human myocardium in patients dying from myocardial infarction complicated by ventricular fibrillation. The similarity of ultrastructural and autolytic changes was revealed in both series of observation. Overcontraction of myofibrils and redistribution of the mitochondria in cardiomyocytes, increase of the sarcoplasmic reticulum vesiculation, oedema of sarcoplasm, structural alterations of intercalative discs, later appearance of the symptoms of the irreversibility of lesions in the mitochondria and early penetration of colloidal lanthanum particles in rigor cells may serve ultrastructural diagnostic symptom of ventricular fibrillation. A better preservation of Purkinje's cells as compared to the contractile cardiomyocytes is also demonstrated.

Animals↗
PubMed1985

[Ultrastructural characteristics of chondroblastomas].

The ultrastructure of chondroblastomas and two new ultrastructural peculiarities typical of the given form of tumours are described. Being typical but not constant these peculiarities may be an additional argument indicating that such cells may be regarded as chondroblastoma cells. The ultrastructure of these cells is similar to that of normal epiphyseal chondrocytes and differs from the ultrastructure of chondrosarcoma cells.

Adolescent↗
PubMed1985

[Ultrastructural variants of the cellular composition of human pulmonary adenocarcinomas].

Fifty-four lung adenocarcinomas of various degrees of differentiation were studied electron microscopically. Two groups of cells-differentiated, with the ultrastructural organ- and tissue-specific features, and undifferentiated, without such ultrastructural features were distinguished as a result of this study. Differentiated tumour cells may have ultrastructural features of pneumocytes II (osmiophilic membranous bodies), goblet cells and serous cells (mucous or serous granules), cylindrical cells (microvilli, cilia), squamous epithelium (tonofibrils, desmosomes) and possibly endocrine type cells (endocrine secretory granules) and pneumocytes I (pinocytotic vesicles). The quantitative correlation between differentiated and undifferentiated cells significantly varies with adenocarcinomas, in some tumours only undifferentiated cells being present. One or several cell types may be found in one tumour. There is a correlation between the degree of tumour differentiation at the histologic and ultrastructural level.

Adenocarcinoma↗
PubMed1979

Abnormalities of hepatic mitochondrial urea-cycle enzyme activities and hepatic ultrastructure in acute fatty liver of pregnancy.

Two patients presenting with acute fatty liver of pregnancy were studied. Because of similarities between acute fatty liver of pregnancy and Reye's syndrome, we investigated hepatic ultrastructure, urea-cycle enzyme activities, and plasma amino acids. Initial liver biopsies obtained 12 and 21 days after the onset of illness demonstrated microvesicular fat deposition and mitochondrial ultrastructural changes, including pleomorphism and abundant crystalline inclusions. In both biopsies, activity of the mitochondrial urea-cycle enzyme OTC was markedly below normal limits. Activity of the other mitochondrial urea-cycle enzyme, CPS, was low in one patient. Abnormalities of these enzymes persisted in second biopsies obtained at 9 and 28 weeks, respectively. By 44 weeks all urea-cycle enzyme activities had returned to normal in one patient. However, in the other patient OTC activity was still reduced at 52 weeks, although it had doubled in comparison to previous biopsies. Morphological changes of the mitochondria generally improved in parallel with the urea-cycle enzymes. Plasma amino acids, obtained at the time of the initial biopsies, demonstrated a generalized hypoaminoacidemia with the exception of glutamate. Serial observations in patients with this rare disease indicate that there are similarities with Reye's syndrome, in particular, reduced activity of the mitochondrial urea-cycle enzymes. But there are important differences. (1) Enzymatic and ultrastructural abnormalities of mitochondria persist for a longer period of time than in Reye's syndrome. (2) Mitochondrial ultrastructure is different. (3) Plasma amino acid profiles are different.

Acute Disease↗
PubMed1977

Histological and ultrastructural study on the subcommissural organ of Bradypus tridactylus.

The subcommissural organ (SCO) of the Bradypus tridactylus was studied from the histological and ultrastructural point of view. The methods of GOMORI (alum-chromic-hematoxylin-phloxine), AZAN (M. Heidenhain), KLUVER and BARRERA (for nerve cells and myelinated fibers) and silver impregnation according to PALMGREN and CAJAL-DE CASTRO, were used. The material prepared for ultrastructural analize was submitted to the sequence of gluteraldehyde, osmium tetroxide, uranyl acetate and lead citrate. In function of the secretory phenomenon, a systematic study is made of different hystological and ultrastructural characteristics of the SCO and hypendymal rosettes, which were considered in the B. tridactylus as a morphofunctional unit. Fine vascular and nerve networks were observed, by the basal parts of the compact tubule alveolar system (hypendymal rosettes) which composes part of the SCO. Nerve fibers were seen between its cells reaching even up to the lumen, and they may end there in bulbar dilatations which seem to show secretory characteristics at the ultrastructural examination.

Animals↗
PubMed1981

[An ultrastructural study of human ovarian yolk sac tumor--an investigation of its histogenesis compared to that of human yolk sacs (author's transl)].

For the purpose of investigating the histogenesis of the yolk sac tumor, 7 cases of the tumor and 9 cases of human yolk sac were used. Histological, ultrastructural investigations together with immunofluorescent antibody examinations revealed the following results. Ultrastructurally yolk sac endodermal cells prior to the 7th week of pregnancy were proved to have microvilli, abundant glycogen which formed rosette, parallel arranged rough endoplasmic reticulum (rER), mitochondria closely associated with rER and ovoid electron dense amorphous granules which showed positive diastase-resistant PAS-reaction. Morphologically endoderm after the 8th week of pregnancy showed degenerative changes. Light microscopically the tumors showed Schiller-Duval body, endodermal sinus structure and clear-cells endoblastic pattern, but ultrastructurally the tumor cells of these three types showed approximately similar appearances. Ultrastructural features of the tumor seem to resemble those of the yolk sac endoderm before the 7th week of pregnancy. The tumor cells which form the epithelial mantling of Schiller-Duval body closely resembled the endodermal cells facing the yolk sac cavity with respect to the presence of abundant glycogen granules, rER, mitochondria, short irregular microvilli on the cell surface and remarkable nucleolus with thread-like nucleolonema. Both the tumor cells facing the endothelial cell and those which form the endodermal sinus structure and clear-cells endoblastic pattern resembled the endodermal cells facing the mesenchyma in view of the features of intracellular organelles, the presence of extracellular basement membrane-like substances and tubular structure.

Adolescent↗
PubMed1982

[Postactivation changes in the ultrastructure of motor neurons].

The prolonged high-frequency synaptic activation of the frog spinal motoneurons suppressing their firing, leads to an increase in the size of synapses and to a considerable shift in their ultrastructure. Restoration of the functional and morphological alterations in the cells after cessation of their rhythmical activation proceeds with different speed: the restoration of neurons' ability to generate synaptic and spike potentials in response to testing stimulation of afferents occurs much earlier than the restoration of the cells' ultrastructure and size. Neurons with obviously changed ultrastructure of soma and synaptic apparatus are capable of generating synaptic and spike potentials in response to stimulation. At the same time, the size of the neurons returns to normal either than the normalizing of cell ultrastructures whose speed of restoration varies as well.

Action Potentials↗
PubMed1982

[Ultrastructural characteristics of the parenchymatous cells in breast cancer].

Electron microscopy was used to examine ultrastructure of parenchymatous cells of lobular mammary carcinoma and preservation of an ability of these cells to organ specificity. Ultrastructural characteristics of the cells of intact mammary gland lobules and parenchymatous cells of infiltrative carcinoma were studied and compared. It was shown that lobular mammary carcinoma has dissimilar cellular composition. It is represented by the cells with ultrastructural features characteristic for the three cell types occurring in the intact mammary gland (secretory epithelium, myoepithelium and cambial cells). As regards ultrastructure, parenchymatous cells of lobular mammary carcinoma, like the cells of the normal lobule, are at varying levels of differentiation and in diverse phases of the functional status.

Breast↗
PubMed1984

Ultrastructure of squamous cell carcinoma of the lung.

No extensive ultrastructural description of squamous cell carcinoma of the lung has been provided in the generally available literature thus far. The concise accounts of its ultrastructure usually presented may create the impression that squamous cell carcinomas of the lung show little more distinctive features than intercellular bridges, tonofibrils, prominent desmosomes, and paucity of cytoplasmic organelles. The process of keratinization in these tumors has only incidentally been briefly illustrated. In order to give a more detailed account of these tumors, we investigated an essentially unselected series of 40 lung tumors, diagnosed on light microscopy as squamous cell carcinomas, using World Health Organization criteria. Both at tissue and at cell level, the tumors showed highly variable ultrastructural details. Part of these, such as entrapment of sometimes poorly recognizable alveolar remnants, and the discrepancy sometimes found between prominence of tonofibrils and desmosomes on the one hand, and intercellular bridging on the other, may be of importance in diagnostic classification and grading. The emergence of unmistakable ultrastructural adenodiffentiation in tumor cells lining lumina formed on the basis of necrosis or keratinization, described for the first time, demonstrates that squamous and adenodifferentiation are even more closely intermingled than usually appreciated. The possibility is envisaged that the variability found in these tumors may correlate with differences in clinical behavior, not necessarily parallelled by differences in light microscopical grading.

Carcinoma, Squamous Cell↗
PubMed1984

Ultrastructural damage associated with the Ca2+ paradox. The protective effect of Mn2+.

Hearts repleted with Ca2+-containing buffers after only a few minutes of Ca2+-free perfusioN display extensive ultrastructural damage and accumulate Ca2+. Ultrastructural damage includes separation of the intercalated disks, development of contracture bands, and splitting of the internal and external layers of the glycocalyx. In this study, the authors have used isolated spontaneously beating Langendorff perfused hearts to investigate whether Mn2+ alters the ultrastructural damage associated with Ca2+ repletion after Ca2+-free perfusion, previous studies having shown that it attenuates or abolishes the gain in Ca2+ which normally occurs under these conditions. Mn2+ added only at the time of Ca2+ repletion did not attenuate the ultrastructural damage. When Mn2+ (2 mM) was added during the Ca2+-free period or the Ca2+-free and Ca2+ repletion periods, however, the hearts were not as extensively damaged. The myofibrils were relaxed, and the intercalated disks were intact. However, splitting of the glycocalyx still occurred and was a prominent feature. These results indicate that splitting of the glycocalyx per se does not necessarily result in a massive gain in Ca2+ when Ca2+ is returned to Ca2+-depleted hearts. Possible mechanisms of action of Mn2+ are discussed.

Animals↗
PubMed1983

Role of ultrastructural techniques in understanding mechanisms of metal-induced nephrotoxicity.

The combined use of ultrastructural morphometry and X-ray microanalysis in conjunction with biochemical analysis is one approach to elucidating mechanisms of metal nephrotoxicity at the cellular level. Ultrastructural morphometry conducted on proximal tubule cells of rats exposed to low levels of methyl mercury for prolonged periods of time showed statistically significant increases in the volume densities of the lysosomal and mitochondrial compartments. These findings were associated with marked changes in lysosomal marker enzymes and mitochondrial heme biosynthesis enzymes leading to the detection of a renal porphyrinuria that occurred before changes in standard tests of renal function. Ultrastructural morphometry, X-ray microanalysis, and biochemical studies of the low-molecular-weight tubular proteinuria produced by injection of cadmium metallothionein (CdMT) showed a rapid proximal tubule cell lysosome uptake and degradation of the CdMT complex, which led to a subsequent decrease in the numerical density (Nv) and average diameter of lysosomes and to an increase in the Nv of apical pinocytolic vesicles with time. The data indicate disruption of the normal primary lysosome-pinocytolic vesicle fusion process and related development of tubular proteinuria. Ultrastructural techniques may provide information useful in elucidating mechanisms of ongoing metal-induced nephrotoxic processes when consideration is given to sampling strategies for morphometric analysis and the inherent detection limits, elemental volatility, translocation effects, and limitations of quantification for X-ray microanalysis in soft biological tissues.

Animals↗
PubMed1978

[Cutaneous dyschromia in three cases of phenylketonuria. Quantitative ultrastructural study of the basal layer of the epidermis (author's transl)].

The authors have studied skin color modifications in 3 cases of phenylketonuria and have observed the characteristic changes; fair skin and fair hair. In addition they noted hundred of pigmented pin point or slightly larger patches in the two more affected patients, in the areas exposed to sunshine. With regard to the ultrastructural study of the epidermis basal layer, the proportion of melanocytes in the two most severe cases was slightly higher than in the normal skin of 6 control subjects. Langerhans cells could not be acertained. The more severe was the disease the greater was the tendency for a lower proportion of keratinocytes containing melanin. There is a certain parallelism between the skin color modifications the biochemical examinations (blood level of phenylalanin and tyrosine) and the ultrastructural changes. The higher the blood level of phenlalanine and/or the more pronounced the disorders of skin color, the more evident would be the ultrastructural changes: higher proportion of melanocytes that usually do not produce the melanosomes, and lower percentage of keratinocytes with melanin. On the other hand, the ultrastructure of the basal layer would suggest the seriousness of clinical manifestations and/or the intesity of the metabolic error.

Child↗
PubMed1982

Evidence for complement-induced endothelial injury in vivo: a comparative ultrastructural tracer study in a controlled model of hyperacute rat cardiac allograft rejection.

In order to delineate the potential role of platelet-derived factors and of the direct lytic action of complement in the pathogenesis of endothelial injury in hyperacute allograft rejection, a highly reproducible and rigidly controlled inbred rat cardiac model was studied, utilizing colloidal carbon as a vascular tracer for comparative ultrastructural analysis of the microcirculation. Unmodified allografts were characterized by widespread intramural carbon labeling of the microvasculature, which corresponded to sites of platelet sequestration and extensive endothelial cell disintegration. Under conditions of recipient platelet depletion without concomitant complement depression, carbon-labeled segments of the microcirculation showed widespread endothelial cell disintegration, the ultrastructural features of which were similar to those observed in the unmodified allograft group. The microvasculature of syngeneic heart grafts transplanted to platelet-depleted recipients as well as all platelet-depleted recipients' own hearts showed no similar ultrastructural changes. It is thus concluded that the loss of cellular integrity of the microcirculatory endothelium in hyperacute rat cardiac allograft rejection is not a platelet-dependent phenomenon. The current ultrastructural data combined with previous morphologic studies provide strong evidence that the severe form of endothelial injury observed in this model is mediated by the direct action of activated complement components.

Animals↗