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PubMed1975

Colchicine administration to mice: a metabolic and ultrastructural study.

A single injection of colchicine has been administered to normal albino mice, and the metabolic effects as well as the hepatic ultrastructural changes resulting from this treatment have been studied at various time intervals. A marked decrease in circulating triglyceride levels was evident 4 hours after colchicine injection and was maximum after 11 hours. It coincided with a marked increase in hepatic triglyceride content. Twenty hours after colchicine administration, plasma triglyceride levels and hepatic triglyceride content had returned to normal values. Similar changes in the levels of circulating proteins were observed although their magnitude was less than that observed for triglycerides. Ultrastructurally, colchicine treatment resulted in the virtual disappearance of the microtubules from the hepatocytes, and in the appearance of many clusters of vesicles containing very low density lipoprotein-like particles which eventually transformed into lipid droplets. These ultrastructural alterations were also completely reversible, the reversibility coinciding with the morphological reappearance of microtubules. Finally, colchicine treatment resulted in marked metabolic changes that are interpreted as representing an attempt, by the organism, to keep adequate energy sources during the period of lack of circulating triglycerides.

Amino Acids↗
PubMed1981

The endocrine component of prostatic carcinomas, mixed adenocarcinoma-carcinoid tumours and non-tumour prostate. Histochemical and ultrastructural identification of the endocrine cells.

Two types of endocrine-paracrine (EP) cells have been detected histochemically and ultrastructurally in normal and hyperplastic prostates; i.e. type I cells resembling intestinal EC (enterochromaffin) cells and type 2 cells similar to urethral EP cells previously reported by Casanova et al. (1974). About one-third of the 40 prostatic carcinomas studied contained EP cells: two of these were composite tumours exhibiting both adenocarcinomatous and carcinoid patterns. These four tumours have also been studied histochemically and ultrastructurally. ACTH and beta-endorphin immunoreactive cells, ultrastructurally resembling pituitary corticotrophic cells, have been identified in three tumours. Cells identical with type I and type 2 cells of the normal prostate were detected in two cases and in a further case, respectively.

Adenocarcinoma↗
PubMed1982

Monophasic synovial sarcoma, epithelioid sarcoma and chordoid sarcoma: ultrastructural evidence for a common histogenesis, despite light microscopic diversity.

Ultrastructural examination of six rare sarcomas--four monophasic spindle cell tumours, one epithelioid sarcoma, one chordoid sarcoma--has revealed marked similarities at the electron microscopic level despite widely divergent light microscopic appearances. These features consisted of: 1 the presence of two cell types, viz. a clear cell and a cell resembling the fibroblast; 2 pseudoglandular spaces with projecting microvilli or filopodia, and with related tight junctions; 3 an amorphous intercellular ground substance with focal condensation into recognizable basement membrane. The findings suggest a common maturation of these diverse tumours to synovial-like tissue, and support the proposal of Hajdu Shiu & Fortner (1977) that these be considered variants of synovial sarcoma. Published ultrastructural studies of synovial, epithelioid and chordoid sarcoma are reviewed in the light of these findings. The ultrastructural differentiation of synovial sarcoma from extraskeletal myxoid chondrosarcoma, chordoma and the spectrum of malignant spindle cell tumours is discussed.

Adult↗
PubMed1983

Adenosquamous carcinoma of the stomach: histological, histochemical and ultrastructural observations.

The histochemical and ultrastructural features of an adenosquamous carcinoma of the stomach have been studied. Both the adenomatous and the squamous component of the tumour showed malignant characteristics. Elements which were considered as undifferentiated cells on light microscopy showed ultrastructural features of poorly differentiated squamous cells. No intermediate cells, sharing squamous and glandular aspects, were found by electron microscopical examination. The adenomatous component exhibited histochemical and ultrastructural features of the intestinal type of gastric carcinoma and the mucosa surrounding the tumour showed a colonic type of intestinal metaplasia. A possible histogenesis from a totipotential undifferentiated cell is considered.

Adenocarcinoma↗
PubMed1983

Evidence for differentiation in medulloblastomas appearing primitive on light microscopy: an ultrastructural study.

Surgical biopsy specimens from five children with cerebellar medulloblastoma were examined for ultrastructural evidence of differentiating activity. At light microscope level, all the tumour samples appeared primitive and featureless, and could not be classified as showing either neuroblastic or spongioblastic differentiation. Using electron microscopy, the major part of each specimen examined likewise showed largely primitive and undifferentiated appearances typical of medulloblastoma. In all the cases however, scattered groups of cells and related cytoplasmic processes were found with more specific, differentiated features. Moreover, in each tumour sample, these cells and processes were found to show two morphologically distinct appearances. One cell type had ultrastructural features reminiscent of primitive neuronal morphology, and a similar appearance was found in cell perikarya forming rosettes. The other cell type showed evidence of spongioblastic differentiation, with bundles of glial-like filaments in the cytoplasm. Cilia were also found in one case. Whilst in keeping with current views on the neuroectodermal origin of the tumour, these observations suggest that all medulloblastoma cells may have bipotential differentiating capacity, and that at least some evidence of this is likely to be found ultrastructurally, even when there is only a primitive and completely undifferentiated appearance on light microscopy.

Adolescent↗
PubMed1985

Ultrastructural analysis of salivary gland pleomorphic adenoma, with particular reference to myoepithelial cells.

Previous ultrastructural studies of pleomorphic adenoma have presented conflicting results with regard to the role of myoepithelial cells in the histogenesis of this tumour. In the present study specimens of ten major salivary gland pleomorphic adenomas were examined ultrastructurally and a number of cell types identified. The material was subjected to quantification using the stereological method of point counting. The results showed a wide spectrum of differentiation within these tumours in which typical myoepithelial cells were rarely encountered even in situations where they are reported to occur in routine histological preparations. Cells with some myoepithelial features were more numerous but duct cells accounted for the majority of tumour cells. The ultrastructural findings correlated well with previously reported immunocytochemical data and further support certain ideas about salivary gland tumour histogenesis.

Adenoma, Pleomorphic↗
PubMed1985

Ultrastructural similarities of adenoid cystic carcinoma and pleomorphic adenoma.

Ultrastructural examination of five adenoid cystic carcinomas, three breast and two salivary gland, reveals identical patterns of tumour cell differentiation, organization and distribution of cellular products (Zaloudek, Oertel & Orenstein 1984). In both sites, there is proliferation of two populations of cells, one with characteristics and organization of duct-type luminal epithelial cells and a second that forms the principal proliferating component and has the overall organization and appearance that would suggest that they represent modified myoepithelial cells. Recent ultrastructural studies also indicate that tumour cell types and histological organization similar to those described for adenoid cystic carcinoma occur during histodifferentiation of salivary gland pleomorphic adenoma (Dardick et al. 1983a, b). The characteristic histological pattern of adenoid cystic carcinoma is dependent on the formation of pseudolumina containing proteoglycans and reduplicated basal lamina. Similar, but smaller, lumina of like organization and contents are evident in some cases of pleomorphic adenoma. Both the ultrastructural similarities of the tumour cell types and their organization, in adenoid cystic carcinoma and pleomorphic adenoma, suggest that these tumours have a similar histogenetic basis. The fact that one lesion is malignant and the other benign does not preclude common types of tumour cells and developmental processes.

Adenoma, Pleomorphic↗
PubMed1986

An ultrastructural study of mucoid carcinoma of the breast: variability of cytoplasmic features.

The ultrastructural characteristics of 14 cases of mucoid carcinoma of the breast, with different histological appearances, have been examined. Thirteen of the tumours were observed to consist of two populations of tumour cells, one showing secretory changes while the other group showed no evidence of activity. In one tumour only synthetically active cells were observed. Ultrastructurally, six different types of cytoplasmic granules, comprising typical mucin plus glycoprotein or protein-containing granules, were identified within the synthetically active tumour cells. The number of types of granules and the relative proportion of the various granules varied between tumours with only mucin granules present in all tumours. It would appear that synthetic pathways are activated in certain tumours which result in protein/glycoprotein granules associated with the argyrophilia observed histologically. In addition, the tumours varied with respect to luminal differentiation, presence of intracytoplasmic lumina, intracytoplasmic mucin pools, lipid droplets, ciliated cells and areas of calcification. The marked heterogeneity of the ultrastructural features of the mucoid carcinoma of the breast prevents the tumours from being readily divided into distinct subgroups.

Adenocarcinoma, Mucinous↗
PubMed1992

Peripheral nerve sheath differentiation in malignant soft tissue tumours: an ultrastructural and immunohistochemical study.

Thirteen soft tissue sarcomas with ultrastructural evidence of nerve sheath differentiation were investigated by immunohistochemistry. Three arose in a major nerve or nerve trunk and four patients had von Recklinghausen's neurofibromatosis. Ultrastructurally, 10 cases showed variable differentiation towards Schwann cells, two resembled perineurial cells and one tumour had features suggestive of both cell types. Immunostaining for S-100 protein was positive in eight Schwann cell tumours, negative in the other two Schwann cell tumours and negative in those with perineurial-like cells. No cases demonstrated epithelial membrane antigen, so that the existence of perineurial cells in malignant nerve sheath tumours remains immunohistochemically unsubstantiated; it may be that the perineurial-like cells are merely incompletely differentiated Schwann cells, with nerve sheath differentiation manifesting a continuous spectrum. Leu 7 was detected in four Schwann cell tumours, three of which were ultrastructurally well differentiated. Cytokeratin and desmin were demonstrated only in an undifferentiated pleomorphic area of one Schwann cell tumour. Electronmicroscopy can aid diagnosis by revealing nerve sheath differentiation in malignant soft tissue tumours without demonstrable S-100 protein.

Adolescent↗
PubMed1987

Ultrastructure of syncytiotrophoblast-like cells in seminomas of the testis.

An ultrastructural examination of five syncytiotrophoblast-like cells (STLC) from three otherwise pure seminomas was performed. All five STLC demonstrated ultrastructural features identical to those of normal syncytiotrophoblastic cells. The STLC were surrounded by sinusoidal spaces and cells whose ultrastructure was compatible with that of seminoma cells, though the presence of cytotrophoblastic cells cannot be excluded with certainty. We conclude that STLC in seminomas are indeed syncytiotrophoblastic and their genesis remains an enigma.

Dysgerminoma↗
PubMed2003

The endothelin-1 receptor antagonists ameliorate histology and ultrastructural alterations in the pancreas and decrease trypsinogen activation in severe taurocholate pancreatitis in rats.

The role of potent vasoconstrictor endothelin-1 (ET-1) in acute pancreatitis (AP) remains controversial. The aim was to compare the effect of nonselective ET RA/B (LU-302872) and selective ET RA (LU-302146) antagonists on pancreatic histology, ultrastructure and trypsinogen activation in severe taurocholate AP in rats. Male Wistar rats with AP were treated with an intraperitoneous injection of 1, 5 and 10 mg/kg of body weight of each antagonist at 0, 6, 12 and 18 h after taurocholate administration. After 24 h, the samples of pancreases were taken for histological and ultrastructural examinations and for assessment of trypsinogen activation. Both antagonists, at all investigated doses, decreased the damage to the acinar cells detected in the light microscope and ultrastructurally. Trypsinogen activation increased to 29.7 +/- 3.9% in the AP untreated in comparison to the control group [12.7 +/- 1.4% (P<0.001)]. This increase was attenuated to 13.8 +/- 2.2% in AP treated with a high dose of the nonselective antagonist and to 8.4 +/- 1.7% with low dose of selective antagonist. The obtained results indicate that ET-1 could participate in the damage to the pancreas during AP. Both antagonists of ET-1 receptors exerted a similar beneficial effect on the morphological changes of the pancreas in AP. One of the probable mechanism could be the attenuation of trypsinogen activation.

Acute Disease↗
PubMed1992

Immunohistochemical, ultrastructural and immunoelectron microscopic studies of spinal cord neurofibrillary tangles in progressive supranuclear palsy.

Immunohistochemical, ultrastructural and immunoelectron microscopic studies of spinal cord neurofibrillary tangles (NFTs) in progressive supranuclear palsy (PSP) were performed. The spinal cord NFTs reacted with antibodies to tau protein (tau-2), ubiquitin and Alzheimer neurofibrillary tangles (ANTs, Ab 39). Ultrastructurally, the NFTs consisted of bundles of straight fibrils. In longitudinal sections, the individual NFT fibrils appeared as straight fibrils with a diameter of approximately 15 nm. In cross sections, circular structures approximately 15 nm in diameter were seen, and some had a central density. Electron microscopic examination of specimens stained with the antibodies and by the modified Bielschowsky method revealed the products of the tau, ubiquitin and ANTs immunoreactions and silver deposits on the NFT fibrils. This is the first demonstration of the ultrastructure of spinal cord NFTs in PSP.

Adult↗
PubMed1993

Ultrastructure of Trichophyton violaceum.

BACKGROUND: The ultrastructure of different fungi have been described in recent literature; however, few reports have concerned dermatophytes. METHODS: Fine structure of Trichophyton violaceum was observed using electron microscopy. RESULTS: Hyphae appeared as branched segmented filaments with a cell wall consisting of two layers. Thin electron dense plasma membrane was evident continuous with the inner surface of the cell wall. Septal walls with central pores and a uniform electron opacity plugs were seen. The hyphae were multinucleated and the cytoplasm contained endoplasmic reticulum, mitochondria, and vacuoles. CONCLUSIONS: Although these findings showed ultrastructural similarities of the cell wall with Microsporum canis, Microsporum gypseum and Microsporum audouinii, there were some points of difference in the ultrastructure of the hyphae in Epidermophyton floccosum, and in the mitochondria of Trichophyton mentagrophytes as described by other investigators.

Microscopy, Electron↗
PubMed1989

Cytological, immunocytochemical and ultrastructural study of the adenohypophyseal pars distalis of the kid (Capra hircus): the TSH cell.

The structure and ultrastructure of the adenohypophyseal pars distalis in kids of the Murciano-granadiana breed (18 males and 12 females), aged 2-3 months and with an average carcass weight of 8 kg has been studied. Techniques of staining (Tetrachrome Herlant's, and Cleveland-Wolfe) and histochemistry (PAS, PAS-OG and BA-PAS-OG) contrasted with immunolabelling (PAP) have been used. In addition an ultrastructural study has been made and nucleus and cytoplasm, secretory granules, mitochondria and lysosomes have been measured with a semiautomatic image analyzer (IBAS-1). TSH cells are found in sagittal section in the anterior area and in an antero-caudodorsal band, and transversally in the ventral and medial region; they are 6% and their average size is 14.15 microns. Ultrastructurally they are a single cellular type with spherical granules whose size is 195 nm in males and 149 in females; these granules are characterized by a clear halo and a variable electronic density. The rough endoplasmic reticulum is found as slightly enlarged vesicles with a homogeneous and moderately electro-dense content or in concentric stratifications.

Animals↗
PubMedDate not supplied

Quantitative and ultrastructural study of germinal epithelium in testicular biopsies with "mixed atrophy".

In 17 cases of male sterility with so-called "mixed atrophy" in testicular biopsies, the germinal epithelium was investigated by quantitative as well as by ultrastructural means. In 13 cases, the number of spermatids only was reduced, in 2 cases earlier stages of germinal cells were diminished also. Normal quantitative data were found in biopsies of 2 patients. Among ultrastructural alterations various disturbances of the acrosome were dominant. Additional ultrastructural findings in spermatids included binucleate forms and lack of mitochondrial sheaths in the middle-piece. The largely uniform changes in the tunica propria (fibrosis of the innermost layers, extensive changes of the basement membrane) were considered to be at least one of the cofactors responsible for the alterations of the germinal epithelium.

Adult↗
PubMed1992

Testicular ultrastructure of Zebu bulls in Costa Rica.

The testicular ultrastructure of sexually mature Zebu (Bos indicus) bulls from Costa Rica was studied in relation to their classification based on andrological examinations undertaken in the field. Based on the testicular consistency at palpation, each bull was assigned to one of three groups, ranging from normal (Group A) to markedly reduced testicular consistency (Group C). The ultrastructure of the clinically normal testicle (Group A) in the Zebu bull resembled that of Bos taurus. In testicles with a slight to moderate reduction of testicular consistency (Group B) degenerated primary spermatocytes and spermatids were common at all stages of the seminiferous cycle. Abnormalities in the condensation of the chromatin, acrosomal defects, and the presence of degenerated cells and cellular debris were the most common of disturbances found. In testicles from bulls with a marked reduction of testicular consistency (Group C) the seminiferous epithelium of most tubules showed degenerative changes, thereby making it impossible to classify the stage of the cycle. The changes were mainly restricted to spermatocytes and spermatids, whose relative numbers were reduced. The number of cells undergoing meiotic divisions was also greatly reduced. Changes in the spermatids were also found including the appearance of severe acrosomal defects, such as acrosomal pouches, the failure of nuclear elongation and clear defects in chromatin condensation. The present ultrastructural findings in Bos indicus do not differ from the picture of normal testicular structure and of testicular degeneration usually found in Bos taurus bulls.

Animals↗
PubMedDate not supplied

Ultrastructural investigations of Candida albicans after in vitro treatment with the new fungicidal agent rilopirox.

Candida albicans was maintained in various culture media and incubated with different concentrations of the antifungal agent rilopirox. After fixation, dehydration and embedding in Spurr's medium, the cells were analysed at the ultrastructural level to investigate morphological aspects of the antifungal mode of action of this new hydroxpyridone compound. All untreated or sham-treated control cells exhibited a normal ultrastructural appearance. The cells were surrounded by a multilayered cell wall of typical structure, and the plasmalemma was in close contact with the cell wall. Also, the cell organelles of the protoplast corresponded well with the findings of other authors. After treatment with rilopirox, a variety of ultrastructural changes were seen, and the extent of damage was dependent on the specific culture condition, drug concentration and incubation time. After only 6 h and 1-10 micrograms ml-1 rilopirox, the plasmalemma exhibited elongated invaginations, the number and size of the lipid droplets had increased and greatly enlarged mitochondria containing electron-dense deposits became visible. The vacuolar system was strongly expanded and occupied nearly the whole cell. Exposure to higher concentrations of the antifungal agent and prolonged incubation times resulted in complete cytoplasmic autolysis and membrane breakdown, while the fungal cell wall remained unaffected. After treatment with 0.5% rilopirox suspension gel on agar cultures, the extent of cellular damage was clearly enhanced and included all cell types of a treated yeast colony, i.e. single blastospores and pseudohyphae.

Antifungal Agents↗
PubMed1981

Ultrastructural changes in the brain of rats administered with 6-hydroxydopamine.

Adult Wistar rats were treated with 6-Hydroxydopamine (6-OHDA, 200-500 micrograms) by intraventricular injection. Two, five, seven or 14 days after the injection, the effects of 6-OHDA on rat behavior and the brain ultrastructure were observed. The increased irritability and the tendency of a decrease in self-grooming along with a reduced spontaneous movement were found in rats given 6-OHDA. The main ultrastructural alterations were observed in the nerve terminals localized in the catecholaminergic neurons, particularly the hypothalamic axon terminals. These ultrastructural changes might relate to the behavioral abnormalities in the animals.

Animals↗