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PubMed1988

[Ultrastructure of sensorimotor cortex neurons in the progeny of rats receiving alcohol during pregnancy].

Dynamics of ultrastructural changes in the sensomotor cortex neurons has been studied on the 21st, 30th and 60th days of life in offspring born by the rats given 20% alcohol (2 g/kg) during pregnancy. Moderate antenatal alcoholization produces certain disturbances in the ultrastructure of the cortical neurons and their dendrites. This is manifested as presence of retardation signs in maturation of nervous cell populations, as dystrophic changes in the neurons and their dendrites and display of reparative character with their own dynamics in the postnatal period of ontogenesis. The first two categories of the ultrastructural changes in the cortical neurons are more manifested at early stages of the postnatal development of the offspring, and the reparative processes--at the age of two months. Despite the presence of the reparative shifts, the dystrophic changes of the neurons of hypoxic character are present up to the period of sexual maturation. This demonstrates that the antenatal alcoholic intoxication in the offspring is manifested in the postnatal ontogenesis for a long time.

Aging↗
PubMed1988

[Catecholamine-producing tumors of the chromaffin tissue. Morphological and ultrastructural characteristics].

Histological and ultrastructural studies were carried out in 41 hypertensive patients showing increased urine excretion of catecholamines and vanilmandelic acid due to chromaffinoma of the adrenal and other sites: malignant chromaffinoma of the adrenal, including multiple--55%, border-line chromaffinoma--34% and malignant--11% (total--53 tumors). Ultrastructurally, malignant chromaffinoma showed pronounced aniso- and poikilocytosis, lack of desmosomes, presence of dark and clear cells, irregular and bizarre-shaped nuclei and enlarged nucleoli. An inverse correlation between the level of secretory granules and that of organelles was established for all sites and patterns of growth. The data obtained suggest certain ultrastructural peculiarities which alongside with macro- and microscopic features serve identification of malignity of tumor, functional status of tumor cells and type of secretion.

Adolescent↗
PubMed1987

Ultrastructure of spermatozoa from domesticated birds: comparative study of turkey, chicken and guinea fowl.

Typical for non-passerine birds, the spermatozoa of the turkey, chicken and guinea fowl were vermiform with a maximum width of 0.5-0.7 micron and lengths of 90 microns for chicken sperm, and 75-80 microns for those of the turkey and guinea. An acrosome, nucleus, midpiece and flagellum could be distinguished by SEM. The acrosomal cap projected over a perforatorium surrounded by granular material. At its base, the cap encircled apical projections of the nucleus. The nucleus consisted of dense chromatin, and formed a concave implantation fossa where it joined the midpiece of the tail. For turkey and chicken spermatozoa, the neck region of the midpiece consisted of a proximal centriole and its pericentriolar processes oriented perpendicularly to an elongated distal centriole, but guinea sperm contained only a single elongated centriole and associated pericentriolar projections. The centrioles plus their projections to the implantation fossa constituted the non-striated connecting piece. The distal centriole served as the precursor of the flagellum and was longest for turkey sperm. Enveloping the distal centriole and extending to the annulus were 25-30 helically arranged mitochondria. Flagellum ultrastructure consisted of the typical 9 + 2 microtubular axonemal complex but outer dense fibers were absent. A hypertonic diluent immobilized the sperm, condensing the flagellar matrix and obliterating the radial links. Variations in ultrastructure of the above structures between sperm of the three species is discussed and compared with sperm ultrastructure from other non-passerine birds.

Animals↗
PubMed1978

[Rifampicin action on the ultrastructure of E. coli cells].

The ultrastructure of Coli bacteria exposed to rifampicin was studied. Dependence of the level of the ultrastructural changes on the antibiotic concentration and the time of incubation with the antibiotic was shown. After exclusion of the antibiotic from the medium the organism growth with normal ultrastructure was observed.

Dose-Response Relationship, Drug↗
PubMed1986

Some histochemical and ultrastructural observations on the early foetal pig testis.

Testes of foetal pigs between 26 to 35 days post coitum (p.c.) were investigated histochemically and ultrastructurally. Diaphorase and delta 5-3 beta-hydroxysteroid dehydrogenase activities were studied using, respectively, NADH and pregnenolone and dihydroxy androsterone as substrates. Ultrastructurally, attention was focused on the development of mesenchymal cells and on the sustentacular cells in the primitive sex cords in an attempt to detect the origin of Leydig cells. Histochemically there is a concentration of activity toward the interstitium with increasing age. Also the reactions increase in intensity. Ultrastructurally no evidence for Leydig cell development from Sertoli cells could be observed. Mesenchymal cells between the sex cords show a development toward Leydig cells. This is absent in mesenchymal cells in the future tunica albuginea. Before 30 days p.c. no 'true' Leydig cells can be observed morphologically. The role of the rough endoplasmic reticulum/mitochondrial complex, which is present in many mesenchymal and sustentacular cells, is discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1987

Glial cells of the crayfish and their relationships with neurons. An ultrastructural study.

1. Glial cells of the crayfish abdominal ganglia have been studied by transmission electron microscopy. Special attention is paid to the interrelationships between neurons and glial cells. Covers and hemocyte-related elements have also been considered. 2. Glial cells are identified by a common ultrastructure and close relationships with neurons. Four glial classes are considered, depending on their morphology, the compartment of neurons they ensheathe and neuron-glia interface. 3. Four ultrastructural classes of neurons are proposed. They differ in geometry and ultrastructure, as well as in glial covers (complexity and evaginations into the neuron somata). The morphology and organization of glial covers is specific for the neuron type they ensheathe. Specific glial covers do not differ in glia-glia communicatory structures. 4. The morphological and metabolical compartments of neurons are separated from the extracellular matrix or blood by specific glial systems. A system of two cells is interposed between neuron somata and hemolymph or the extracellular matrix. 5. Glial processes are crossed by membraneous tubular systems, at neuron perikarya and axons. Frequent gap junctions of varying area, density and number of IMP are found in the covers of neuron somata. 6. Neuron-glia interface bears numerous communicatory structures for both ionic and macromolecular exchange. They include junctions and transient modifications of membranes. Some of them suggest active transport mechanisms. 7. Modified endocytotic mechanisms seem to be responsible for the glia-to-neuron transfer of macromolecules as well as for the neuron-to-glia transfer of lamellar bodies. 8. The neuropil is divided into glomeruli (electrical or chemical) by glial processes and the trabeculae of the extracellular dense matrix. Neuron-glia membrane appositions have been found in electrical glomeruli. In chemical glomeruli, dense cored vesicles can release their content at neuron-neuron or neuron-glia intercellular cleft, at non-synaptic loci. 9. Neurons of type II contain peripheral complex Golgi systems, associated to subsurface cisternae and neuron-glia gap junctions, suggesting a cooperation of glial cells in specific macromolecular synthesis.

Animals↗
PubMed1978

The use of A23187 to demonstrate the role of intracellular calcium in causing ultrastructural damage in mammalian muscle.

Electron micrographs show that treatment of mouse diaphragm with the divalent cation ionophore A23187 causes major ultrastructural damage in the muscle. During the first 30 min of exposure to A23187, the mitochondria swell markedly but after 40 min they undergo further ultrastructural changes and a rapid dissolution of the myofilaments is also seen at this time. In place only remnants of the filaments remain. It is suggested that the ionophore causes the release of Ca2+ from the sarcoplasmic reticulum which, initially, is taken up by the mitochondria, causing then to swell; after 40 min the mitochondria release the accumulated Ca2+. It is argued that the rise in [ca2+]i stimulates neutral proteases in the myoplasm and that the sequence of events following ionophore treatment may act as a model for the involvement of Ca2+ in various myopathies. We have shown previously (29) that treatment of the cutaneous pectoris muscle of the frog with the divalent cation ionophore A23187 has three major effects: (i) The membrane potential (Em) is depolarized, an action that is found only when the Ca2+ -concentration of the bathing saline is very low. (ii) It causes an increase in resting tension and the development of contraction. This effect is found at both normal (1.8 mM) and low values of [Ca2+]o and is, therefore, independent of Ca2+ entry and of changes in Em. The ionophore is believed to act primarily by releasing Ca2+ from intracellular stores. (iii) It causes major ultrastructural damage to the muscle filaments. The evidence suggests that A23187 acts at the sarcoplasmic reticulum of frog muscle, causing the release of stored Ca2+ , and the consequent rise in [Ca2+]i stimulates a Ca2+ -activated protease which is responsible for the myofilament degradation. A calcium-activated factor has been isolated from rabbit skeletal muscle; this enzyme operates at neutral pH, hydrolyses denatured casein, and specifically removes the Z-lines and alpha-actinin from skeletal muscle (24). A Ca2+ -activated protease with a pH optimum of 7.5 has also been purified from porcine skeletal muscle; it removes Z-discs, degrades troponin and tropomyosin and partly degrades M lines, and it has been suggested that it may have a physiological role in the disassembly of intact myofibrils during the metabolic turnover of myofibrillar proteins (6, 7). This protases is not localized in membrane-bounded sub-cellular particles, but is believed to be in direct contact with the cytoplasm (26). These findings are of particular interest in thelight of recent suggestions that the cellular necrosis observed in various muscle diseases is a consequence of an increased net influx of calcium into cells which causes, in turn, calcium overloading of the muscle mitochondria (34, 35). We have, therefore, extended our previous studies with frog muscle by the examination of the action of A23187 on the mammalian skeletal muscle of mouse diaphragm...

Animals↗
PubMed1987

[Ultrastructural changes in atrial myxoma].

Ultrastructural changes of 20 cases of atrial myxoma were studied. Under the electron microscope, in a large amount of amorphous matrix, the myxomal cells were either scattered or aggregated. There were numerous microvilli-like cytoplasmic processes on the surface of the tumor cells. In many aspects, the ultrastructural features of the tumor cells were similar to those of the smooth muscle cells. The abundant cytoplasmic filaments were one of the most prominent ultrastructural features. Sometimes, some of them could form dense bodies. There were cytoplasmic filaments in the cytoplasmic processes of a certain tumor cells and lots of micropinocytic vesicles beneath the inner surface of the plasmic membrane. Nuclear membrane of the tumor cells often had marked indentation which was probably related to contraction of the cytoplasmic filaments. 2 of 20 lesions showed malignant characteristics. One lesion infiltrated into the atrial myocardium, and the other involved the left and right atria. It is suggested that the atrial myxoma be a true neoplasm of the atrium with potential malignant tendency. It originates from the multipotential mesenchymal tissue and differentiates mainly towards smooth muscle cells.

Adolescent↗
PubMed1987

Ultrastructural study of the nucleus Cuneiformis in the cat.

The Cuneiformis nucleus (Cu.n.) is a reticular nucleus of the mesencephalic tegmentum which is involved in several functions and particularly in locomotor activities. While the physiological properties and the nervous connections of the nucleus have been studied, there is no data about its ultrastructure. Therefore, we investigated this region in cat at the electron microscope and with morphoquantitative methods to clarify its ultrastructural organization and particularly the characteristics of its synaptic complex. The neurons are small and medium in size, with a high nucleo-cytoplasmic ratio and a modest rough endoplasmic reticulum organization. The neuropil is very extensive. Myelinated axons are very numerous. Dendritic profiles whose plasmalemma is almost completely covered by synaptic boutons are observed frequently. There are few somatic synapses; 81% have symmetrical junctions and 23% have round vesicles only. There are numerous synapses in the neuropil, 40% having asymmetrical junctions and 60% containing round vesicles only. The greater functional complexity indicated by the morphological data and the greater extension of the neuropil synapses with respect to that of the somatic ones, suggest that the neuropil is the main site of modulation and integration of the inputs to the nucleus. A highly significant statistical difference between the sizes of the somatic vesicles and those of the neuropil was found. This may point to the presence of distinct populations of vesicles, which may be correlated with the variety of substances (neurotransmitters, neuropeptides etc ...) found in the nucleus. The remarkable ultrastructural similarity between the Cu.n. and the periaqueductal gray matter is discussed.

Animals↗
PubMed1987

Endotoxin: a twofold effect on bone marrow ultrastructure.

Ultrastructural studies of mouse bone marrow reveal that reduction of the marrow-blood barrier precedes the two waves of leukocytosis which follow endotoxin administration. These ultrastructural changes include a decrease in adventitial cover of the marrow sinus wall, an increase in sinus circumference, and a decrease in endothelial cell overlap. The marrow-blood barrier changes which precede the first wave of leukocytosis are transient and are associated with depletion of marrow granulocytes. The changes that precede the second wave of leukocytosis 5 to 6 days later are more sustained and are associated with marked granulocyte hyperplasia. We suggest that endotoxin has two effects on marrow ultrastructure: (1) an early, direct effect on the sinus wall and (2) a later, indirect effect associated with granulocyte proliferation. The late effect may be mediated through endotoxin induced release of colony stimulating factor. Both effects diminish the normal marrow-blood barrier and appear to facilitate cell release from the marrow.

Animals↗
PubMed1986

[Ultrastructural markers in LAV-HTLV III virus infection: study of the rectal mucosa in 16 patients].

Ultrastructural study of rectal mucosa was performed in 6 patients with AIDS related complex (ARC) and in 10 patients with AIDS. There were 16 men (mean age: 39.1 years): 8 homosexuals, 3 Haitians, 2 Africans and 3 IV drug abusers, all having significant titers of LAV antibodies. Two types of ultrastructural markers were observed: tubuloreticular structures (TRS) were found in endothelial cells, lymphocytes and macrophages in 1/6 ARC patients and 10/10 AIDS patients. TRS have already been described in various pathological situations and seem to be related to alpha-interferon, test tube and ring shaped forms (TRF) were observed in lymphocytes and macrophages in 0/6 ARC patients and 6/10 AIDS patients. TRF have been rarely reported previously. The 6 AIDS patients with TRF were 4 homosexuals and 2 Haitians. In two of three of these patients in whom repeated ultrastructural studies were performed, the same markers were found. All AIDS patients with TRF died within a mean time of ten months after the diagnosis had been established, whereas 1/4 AIDS patients without TRF died within seven months and the three others survived for more than 14 months. These data suggest that the association of TRS and TRF in the rectal mucosa could be specific of AIDS. In LAV/HTLV III retro-virus infection, this association is an aggravating factor.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Effect of heparin on the ultrastructure of the fascicular and reticular zones of the adrenal cortex of rats].

The effect of a prolonged use of heparin on the ultrastructure of the zona fasciculata and zona reticulosa of the adrenal cortex was studied in experiment. Heparin was injected subcutaneously to laboratory male rats at a daily dose of 5 mg/kg. The animals were decapitated on the 5th, 10th, 30th and 60th days after heparin administration, 20 and 50 days after 10-day use of the drug and 30 days after 30-day use. In the first days of use heparin stimulated the secretory activity of cells of the zona fasciculata and zona reticulosa of the adrenal cortex. The ultrastructure of the internal area of the zona fasciculata and zona reticulosa indicated the suppression of adrenocorticocytes during the use of heparin for 30 days. In 60-day administration of heparin the ultrastructure of adrenocorticocytes was closer to the control though in cells of the zona fasciculata the content of glycogen exceeded the normal one. In cancelling the drug the adrenal structure got back to normal rather slowly.

Adrenal Cortex↗
PubMed1986

Ultrastructural features of normal mouse colon epithelium. Unique characteristics of a species.

Ultrastructural studies of the colon epithelium of normal C57Bl/Ha and ICR/Ha mice revealed some unique characteristics not seen in human or rat colon. The most striking feature was the presence of a unique type of intracytoplasmic organelle with crystalline internal structure. These organelles measured 1-2 micron in diameter, usually rounded or oval showing marked variation in size and shape. They were surrounded by a single layer of trilaminar plasma membrane and their core structure was mildly electron dense with markedly dense crystalline substructure. Grimelius silver stain done at ultrastructural level revealed these to have staining properties identical to neuroendocrine granules. Approximately 1-5% of the epithelial cells of mouse colon were usually filled with these organelles. But occasionally they were also present in the endocrine cells of colon. The other striking feature of the mouse colon epithelium is the presence of an inordinate number of bacteria. These rod shaped bacteria were present deep inside crypts in large numbers. They were also present within the goblet type of mucous cells and the so-called columnar cells of the surface epithelium. A third unique feature of mouse colon was the presence of mitotic figures in cells with conspicuous mucous vacuoles. This contrasts with human and rat colon where mitosis occurs in cells with little or no mucus. Since the ultrastructural morphology of the normal mouse colon is distinctly different from the human and rat, caution must be exercised in extrapolating colon carcinogenesis data from mouse to human.

Animals↗
PubMed1986

[Ultrastructural changes in the microcirculatory bed and filtration-reabsorption barrier of the kidney during temporary ischemia after unilateral nephrectomy].

Ultrastructure of cellular elements of the microcirculatory bed and filtration-reabsorption barrier has been studied in 150 mature white rats, in which vascular fasciculus of the left kidney has been compressed for 30 min, 1-2 h with a subsequent restoration of the blood stream in the organ undergone ischemia on the 3rd, 7th, 14th, 30th, 60th, 180th, 360th days under conditions of the preliminarily right kidney nephrectomy. On the 3rd day after ischemia of the remained kidney for 30 min, structural components of the walls of the glomerular arterioles and those of the filtration-reabsorption barrier undergo certain ultrastructural changes, that with time elapsed (7, 14 days) gradually pass away, and amount of cells with hypertrophic processes increases. Ischemia for 1 h in the remained kidney with subsequent restoration of the blood stream on the 3rd, 7th days produces in the structures mentioned more pronounced destructive changes. During subsequent compensatory hypertrophy (the 30th, 60th days) of the remained kidney after its ischemia, in the microcirculatory bed elements and in the convoluted canal epitheliocytes intracellular regenerative and hyperplastic processes develop. However, ischemia for 2 h in the remained kidney produces severe destructive-necrotic phenomena in ultrastructure of the microcirculatory bed and of the filtration-reabsorption barrier.

Animals↗
PubMedDate not supplied

The ultrastructure of metastatic adenocarcinoma in serous fluids. An aid in identification of the primary site of the neoplasm.

Identification of the primary sites of metastatic adenocarcinomas is a diagnostic problem, particularly in cases of occult primary neoplasms. We studied the ultrastructural morphology of 16 metastatic adenocarcinomas that presented as effusions to establish organ-specific features that would characterize adenocarcinomas from various sites. The nine cases in which the site of the primary carcinoma was known included seven derived from the breast, one from the ovary and one from the colon. The primary site was unknown in seven cases at the time of presentation. After investigations, the primary site became known in five cases (lung, colon and appendix, one case each, and the ovary in two cases). Ultrastructurally diagnostic features could be detected in gastrointestinal, ovarian, bronchioloalveolar-cell and breast carcinomas. In gastrointestinal carcinomas, the presence of short microvilli with long rootlets was specific for the group. The lamellar inclusions of type II pneumocytes were diagnostic of bronchioloalveolar-cell carcinoma. The microvilli in ovarian carcinomas were long, slender and bushy, as in mesotheliomas; however, the cells lacked the perinuclear condensation of tonofilaments seen in the latter. Breast carcinomas were associated with numerous intracytoplasmic lumina, electron-dense granules and aggregates of small vesicular bodies. We conclude that ultrastructural examination of adenocarcinomas in serious fluids can help to identify the primary site of certain neoplasms or at least shorten the list of possibilities. This may reduce costs and minimize the discomfort patients have to undergo by curtailing extensive invasive investigations in search of unknown primary neoplasms.

Adenocarcinoma↗
PubMed1985

Carotid body hyperplasia in cystic fibrosis and cyanotic heart disease. A combined morphometric, ultrastructural, and biochemical study.

A combined morphometric, ultrastructural, and biochemical study was done on carotid bodies (CBs) obtained at autopsy from 213 patients in a pediatric and young adult population. The objective was to determine whether this group had statistically significant differences in sudden infant death syndrome (SIDS, n = 38), cystic fibrosis (CF, n = 30) and cyanotic heart disease (CHD, n = 17), compared with an age-matched control population (n = 128). Average combined weights of CBs in CF and CHD were significantly greater than those of controls in most age intervals (Student t test, P less than 0.05), and computerized planimetry showed an increase in both total surface area and area of "functional" parenchyma. There was diminished chief cell argyrophilia in 72% of CF CBs, and in 8 cases studied ultrastructurally there was moderate to marked depletion of dense-core neurosecretory granules. Most CBs from patients with CHD showed intense cytoplasmic argyrophilia similar to that of controls. Quantitative analysis for tissue catecholamines showed that dopamine was present in greatest concentration in each group of patients but was significantly elevated in CHD. There were no significant differences in morphometry, ultrastructure, or catecholamine content of CBs from SIDS victims, compared with age-related controls. These data add further support to CBs having a chemoreceptor role in humans with compensatory hypertrophy and hyperplasia occurring in most patients with chronic hypoxia due to CF and CHD. There were no significant findings to indicate that CBs play a direct role in the etiopathogenesis of SIDS.

Adolescent↗
PubMed1985

Ultrastructure of human basophils developing in vitro. Evidence for the acquisition of peroxidase by basophils and for different effects of human and murine growth factors on human basophil and eosinophil maturation.

We examined the ultrastructure of human fetal cord blood mononuclear cells cultured in medium supplemented with supernatants of human T lymphocytes (basophil growth factor, BGF), in medium supplemented with supernatants of cloned mouse leukocytes (mast cell growth factor, MCGF) or in MCGF followed by BGF. These cultures provided the first opportunity to perform detailed morphologic and cytochemical studies of human basophilopoiesis in a nonleukemic setting. Cultures of human fetal cord blood mononuclear cells in BGF contained numerous mature basophils, which underwent a sequence of maturation similar in ultrastructure to that previously described in guinea pigs and mice. The cultures also contained variable but often substantial numbers of eosinophils. Eosinophils exhibited peroxidase activity in secretory structures (Golgi, rough endoplasmic reticulum) and cytoplasmic granules, and peroxidase-positive eosinophil granules were released into the medium by dead eosinophils. By contrast, basophils never exhibited peroxidase-positive Golgi structures or rough endoplasmic reticulum but frequently contained variable numbers of peroxidase-positive granules and occasional small cytoplasmic vesicles. Taken together, these findings suggest that basophils do not synthesize peroxidase but acquire the enzyme by the vesicular uptake of peroxidase released from eosinophils. In medium supplemented with MCGF, cells in the basophil lineage proliferated, but their maturation generally did not progress beyond the early basophilic myelocyte stage. The replacement of MCGF by BGF permitted the basophils (and eosinophils) to complete maturation, as judged by a reduction in overall cell size, increased nuclear segmentation and chromatin condensation, and cytoplasmic granule maturation. Mouse MCGF did not promote the development of mast cells in cultures of human fetal cord blood mononuclear cells, when used either alone or in series with BGF. Indeed, no mast cells were observed in any of the cultures examined in this study. Nor did we find cells with ultrastructural features intermediate between those of basophils and mast cells or with features intermediate between those of basophils and eosinophils.

Animals↗
PubMedDate not supplied

[Ultrastructure of the tegmentum vasculosum of the chicken cochlea].

Ultrastructural studies have been made on the dark and light cells, as well as on their interconnections with capillaries in the tegmentum vasculosum of the chick cochlea. The dark cells exhibit ultrastructural peculiarities which are typical for ion transporting cells: their lower part is presented by a system of numerous cytoplasmic projections filled with mitochondria. The role of the light cells is less evident. It is suggested that they may control the exchange of ions and other metabolites between the dark cells and capillaries. Significant ultrastructural differences are described between the tegmentum vasculosum in chicks and the stria vascularis in mammals.

Animals↗