Journal of submicroscopic cytology and pathology最新文献

The surface pattern of the caeca of the chicken was examined using the scanning electron microscope (SEM) in stages ranging from 11th day of foetal development to 60 days of post-natal life. During incubation the proximal region (basis) of the caecum presented a few irregular elevations, which were later regarded as villi and after hatching, gradually, became longer and wider. These structures were found to be similar to those of the small intestine. The middle (corpus) and distal (apex) regions of caecum presented ridges/folds with short and blunt villi that were even shorter in the apex. The ridges/folds were running longitudinally the inner surface of the corpus while those of the apex were not so well developed.

Cholesterol is a component of cellular membranes and especially abundant in caveolae (50-80 nm flask-shaped invaginations of the plasma membrane). Caveolae are highly numerous in vascular endothelial and smooth muscle cells and have been implicated in a variety of functions, including signal transduction, lipid transport and uptake of macromolecules. Here, the effects of cholesterol oxidase (an enzyme that oxidizes cholesterol in caveolae of living cells) and mevinolin (an inhibitor of cholesterol synthesis) on fine structure and internalization of exogenous markers were studied in rat aortic smooth muscle cells grown on a substrate of fibronectin in serum-free primary cultures. Cholesterol oxidase caused a growth in size of the endocytic compartment with accumulation of enlarged endosomes and lysosomes containing tracer molecules. In parallel, the number of caveolae was reduced by about one fifth. Moreover, the morphology of the Golgi complex was altered with swollen cisternae surrounded by empty-looking vacuoles. Mevinolin suppressed transition of the cells from a differentiated or contractile to a dedifferentiated or synthetic phenotype. In addition, contractile cells were found to ingest horseradish peroxidase (HRP) not only into endosomes and lysosomes but also into Golgi cisternae, especially on the convex/cis side of the stacks, and the endoplasmic reticulum. A similar pathway was noted in contractile cells exposed to cholera toxin B subunit (CTB)-HRP conjugates, a ligand that binds to ganglioside GM1 and at least in part is ingested via caveolae. Mevinolin did not prevent the transport of CTB-HRP to the Golgi complex, but the conjugates were in this case concentrated to the concave/trans side of the cisternal stacks. However, no clear effect on the number of caveolae was noted. The observations indicate an important role of cholesterol and caveolae in the control of endocytic traffic in smooth muscle cells. This function appears most significant when the cells are in a differentiated state.

In the peripheral blood of the roadside hawk, Buteo magnirostris, the following types of granulocytic leucocytes were identified: heterophil, eosinophil and basophil. The heterophils presented acidophilic and spindle shaped granules, the eosinophils possess spherical eosinophilic granules and the basophils showed spherical and basophilic granules. The heterophils and eosinophils presented positive cytochemical reaction to glycogen and basic polyaminoacid, while the eosinophils presented sudanophilic granules, which were also positive for myeloperoxidase. The heterophils, alone, presented positivity for acid phosphatase in some granules and immunoreactivity to TGF-beta1 was observed only in the cytoplasm of the eosinophils. Electron microscopy demonstrated the heterophil granules as predominantly spindle shaped, being strongly electron-dense, while the eosinophils had numerous uniformly electron-dense spherical granules and the basophils presented three different types of granules identified according to their electron-density and the aspect of their matrix.

There is the suspicion that the stink bug Edessa bifida invades cotton fields in Southern parts of North America. To assist in the early detection of the bug, the morphology of deposited eggs of E. bifida is described using scanning electron microscopy (SEM). The study revealed a surface pattern not yet seen in the Pentatomidae. The almost spherical eggs are deposited in batches and fastened both to one another and to the plant surface by secretions in all likelihood produced by the female. The egg surface is characterized by pentagons and hexagons formed by slender ridges. The lumen of these polygons shows 1 to 4 circular elevations of variable size and a flat upper face. In contrast to the ridges the elevations are relatively conspicuous. They are reminiscent of tiny warts and therefore the chorion of E. bifida is referred to as 'wart-like chorion'. Twenty-eight to 31 short aero-micropylar processes are mounted in a circumferential row at the anterior pole of the eggs. The discussion focuses on the variability of the chorion in the stink bugs.

The ultrastructure of the external gill epithelium of the axolotl, Ambystoma mexicanum, has been examined using conventional transmission electron microscopy to elucidate its role in ionic transport. Four cell types are identified in the gill filament and primary gill bar epithelium. These are granular, ciliated, Leydig and basal cells. A fifth cell type, the flat mitochondria-rich cell is only found in the gill bar epithelium. The predominant granular cells display microvilli at their surface and their cytoplasm contains abundant mitochondria, rough endoplasmic reticulum, Golgi complexes, vesicles and PAS+ secretory granules that are extruded at the surface, which along with secretions from the Leydig cells form a mucous coat. The granular cells are joined apically by junctional complexes consisting of zonulae occludens, zonulae adherens and desmosomes. The lateral membranes of granular cells enclose large intercellular spaces that are closed at the apical ends but remain open at the basal ends adjoining capillaries. In AgNO3-treated axolotl, the gills become darkly stained, the silver grains penetrate apical membranes and appear in the cytoplasm, accumulating near the lateral membranes and also enter the intercellular spaces. These findings are consistent with the dual role of the gill epithelium in mucus production and active ionic transport.

The submicroscopic anatomy of the eyes in Petaliella spiracauda and Ptychopera purasjokii is described. These eyes correspond in general to the basic pattern of rhabdomeric pigment-cup ocelli. This, however, does not apply to modifications of the cup cell such as the differentiation of mitochondrial lenses. Corresponding with two sensory cells two extensions of the cup cell capping the eye aperture are crowded with small unmodified mitochondria in the eyes of P. spiracauda. The eyes of P. purasjokii have three sensory cells and the lenticular element is formed by a trifoil-shaped differentiation of three giant mitochondrial derivatives. These derivatives show peripheral appendages of various configurations, all of which resemble the profiles of small mitochondria. The implication of the existence of such appendages is that the lenses in P. purasjokii are derived from many fused mitochondria, rather than from a single enlarged one. It is concluded that the unmodified or modified mitochondrial differentiations in proliferations of the pigment cell capping the opening of the eye cup serve to focalize incoming light. The evolution of mitochondrial lenses in Plathelminthes is considered.

Central venous catheters are commonly used in clinics for the administration of infusion therapy and total parenteral nutrition. Catheter occlusion is the most common noninfectious complication associated with the long-term use of such devices. The cause of catheter occlusion is the formation of a tissue sleeve around the catheter. In this study, a rat model was used to investigate the effects of integrin antagonist peptide on the growth of the tissue sleeve around the jugular catheters. When integrin antagonist peptide was injected subcutaneously, twice daily, for 3 days, at a dosage of 10 mg/kg of body weight/day, the growth of the tissue sleeve was reduced by 40%, as compared to rats injected with saline or control peptide. Morphological study of the tissue sleeve indicated that catheter-related damage to the nearby endothelial cells was associated with the adhesion of platelets and leukocytes to the injured endothelium and accumulation of fibrin in the vicinity. This proposed sequence of events resulted in an increase in the thickness of the tissue sleeve and changes in sleeve transparency.

Previous studies have shown that tachyzoites of Toxoplasma gondii were able to penetrate into macrophages using two mechanisms: phagocytosis and active penetration. We show here that previous incubation of the macrophages or the parasites with staurosporine, a wide range inhibitor of protein kinases, tyrfostin and genistein, specific inhibitors of tyrosine kinases, significantly interfered with the process of parasite-macrophage interaction. Staurosporine treatment induced the formation of many filopodium-like surface projections of the macrophages and markedly increased the attachment of the tachyzoites to the cell surface. Genistein inhibited about 50% penetration of T. gondii into macrophages. Previous incubation of tachyzoites with genistein also significantly inhibited their attachment to and penetration into the macrophages. Confocal laser scanning microscopy was used to locate phosphoproteins in macrophages interacting with tachyzoites. Antiphosphotyrosine antibodies labeled the surface of macrophages, but not L929 cells, incubated in presence of T. gondii, even those cells did not show associated parasites. Anti phosphotyrosine, phosphothreonine and phosphoserine antibodies labeled the region surrounding the parasitophorous vacuoles. These observations suggest that protein phosphorylation is a key event in the process of T. gondii-host cell interaction.

Bee accidents incidence is underestimated because many people do not consult to the physicians. Here it is described for the first time the severe mice adrenal gland damage induced by Apis mellifera venom. Biopsy specimens were obtained from mice adrenal gland and after sample preparation observed in Hitachi H-7100 electron microscope. In this work the ultrastructural analysis showed, 6 h after injection, a non homogeneous smooth endothelial reticulum, and in some places loss of plasma membrane. The fenestrae spaces were bigger and detritus in the capillary lumen were observed. Erythrocytes were seen in a cortical cell. After 48 h of venom injection, expanded fenestrae were observed. Capillary basal membrane was interrupted. Myelin-like figures and autophagic vacuoles were noticed. Swollen smooth endoplasmic reticulum elements and endothelial unfolding to the light were seen. Moreover, swollen Golgi and mitochondria were observed, in some places forming myelinic-like figures. At 144 h after venom injection, widened spaces were noticed in capillary fenestrae. Cellular section showed swollen and lost smooth endoplasmic reticulum elements. Smooth endoplasmic reticulum tubules disappearance suggested non steroidogenesis. In conclusion, we suggest that some of the bee envenoming human clinical manifestations, as is observed in mice, are determined by suprarenal gland damage produced by toxins present in this venom.

Chronic alcoholism alters reproduction and therefore may be responsible for alterations of vas deferens, which are the subject of this analysis in UCh ethanol-drinking rats. The proximal and distal segments of the vas deferens of 20 animals were submitted to macroscopic, light microscopy, electron microscopy and morphometric analysis. The UCh rats showed atrophy of the epithelium of the vas deferens and alterations of the hypothalamus-pituitary axis. Ethanol induces changes in the epithelium of the vas deferens and hypothalamus-pituitary axis of UCh rats.