Cytological mechanisms of the development of mucosal candidiasis after exposure to a steroid aerosol preparation

Mucosal candidosis was induced in CBA mice by intraoral inoculation following treatment with corticosteroid-containing aerosol (beclomethasone dipropionate). Histologically, in hormone treated mice the adherence of the pathogen to the mucosal surface was found during the first hours after inoculation. This is followed by the formation of the germ tubes and invasion in the epithelial layer. Pseudomycelial invasion in the malpighian layer is accompanied by the leukocyte response that limits the further spread of the fungal cells. In intact mice, the inoculation is not followed by the effective attachment of the fungal cells to the mucosal surface and induction of mycotic lesions. In vitro experiments have demonstrated the enhanced adherence of fungal blastospores to the epithelial cells of the hormone treated animals, that appears to be one of the mechanisms in the pathogenesis of candidosis in these animals.     

Resistivity of Red Blood Cells Against High-Intensity, Short-Duration Electric Field Pulses Induced by Chelating Agents

The interaction of human red blood cells (RBCs) with diethylenetriamine-pentaacetic acid (DTPA) or its Gd-complex (Magnevist, a widely used clinical magnetic resonance contrast agent containing free DTPA ligands) led to the following, obviously interrelated phenomena. (i) Both compounds protected erythrocytes against electrohemolysis in isotonic solutions caused by a high-intensity DC electric field pulse. (ii) The inhibition of electrohemolysis was observed only when cells were electropulsed in low-conductivity solutions. (iii) The uptake of Gd-DTPA by electropulsed RBCs was relatively low. (iv) (Gd-) DTPA reduced markedly deformability of erythrocytes, as revealed by the electrodeformation experiments using high-frequency electric fields. Taken together, the results indicate that (Gd-) DTPA produce stiffer erythrocytes that are more resistant to electric field exposure. The observed effects of the chelating agents on the mechanical properties and the electropermeabilization of RBCs must have an origin in molecular changes of the bilayer or membrane-coupled cytoskeleton, which, in turn, appear to result from an alteration of the ionic equilibrium (e.g., Ca²⁺ sequestration) in the vicinity of the cell membrane. Received: 19 January 1999/Revised: 1 April 1999     

The chemical-transformation products of 1,6-dibromo-1,6-dideoxygalactitol and 1,2:5,6-dianhydrogalactitol in aqueous solution

After hydrolysis of 1,6-dibromo-1,6-dideoxygalactitol (1) and 1,2:5,6-dianhydrogalactitol (2), 11 compounds were isolated, three of them as tritylated derivatives. Their structures were established on the basis of chemical evidence and, for four compounds, by X-ray diffraction. The main product of the hydrolysis of 1 was 3,6-anhydro-1-bromo-1-deoxy-dl-galactitol; the end-products of the hydrolysis of 2 were 1,5-anhydro-dl-galactitol, 2,5-anhydro-dl-altritol, and galactitol.     

Effect of prostaglandins on lipid transfer between high- and low-density lipoproteins in human plasma

Prostaglandin (PG) E1 was shown to stimulate the transfer of phosphatidylcholine and cholesterol esters from human high density lipoproteins to low density lipoproteins. The enhancement of the interlipoprotein lipid transfer by PGE1 was observed both at low prostaglandin concentrations under conditions of spontaneous exchange as well as in the presence of the lipoprotein-depleted plasma and the partly purified lipid transfer plasma protein. At the same time PGE2 showed no significant influence on the interlipoprotein lipid transfer. It is supposed that the effect of PGE1 is due to the PGE1-induced reorganization of the high density lipoprotein surface and that the PG-lipoprotein interaction is a factor which regulates cholesterol homeostasis.     

Taurodontism: A biometric study

This study has been carried out in order to clarify various aspects of the phenomenon known as taurodontism. Samples of both taurodont and non-taurodont teeth were measured and statistical analyses were performed on the resultant data from which various conclusions may be drawn. The most important conclusion is that this phenomenon may be defined metrically. The distributions have shown that the taurodont trait grades into the normal and it is quite difficult to make a subjective judgment at the low end of the taurodont range. It is for this reason that an accurate mathematical means for performing this task is so invaluable. The question of the nature of cuneiform single rooted molars was also investigated, and they were found not to be true taurodonts although the statistical procedure classed them as such. It was demonstrated that through the construction of simple plots these teeth could be eliminated from any group classed by analysis as taurodonts. Various metrical attributes were evaluated with respect to their ability to distinguish taurodonts, and two were found to be satisfactory for this purpose in most cases. Certain changes in molar morphology regarding caries and age were also investigated.     

Morphology of defense glands of the opilionids (daddy longlegs) Leiobunum vittatum and L. flavum (Arachnida: Opiliones: Palpatores: Phalangiidae)

Opilionid defense glands consist of 0.5 × 0.9-mm sacs attached to the underside of low tubercles located on the dorsal side of the cephalothorax, posterior to the first pair of legs. Each gland opens via an elongated slit, located in the posterior floor of a crater that is situated at the summit of the tubercle. The center of the sac, called the reservoir, is lined by a cuticle consisting of epicuticle and endocuticle which is continuous through the slit with the exoskeleton. The layers of cuticle vary in thickness with different locations in the gland. A hemocoelomic (basement) membrane, 0.5–1, μ thick, forms the boundary between glandular cells and hemocoel. The gland has a nonsecretory portion consisting only of cuticle-supporting cells and a secretory portion consisting of secretory and cuticle-supporting cells. The cuticle lining the reservoir in the secretory area is broached by many cuticle-lined ductules, each of which drains an isolated intercellular space called the intercalated cistern. This in turn drains microvilli-lined canaliculi located between and extending into secretory cells. The cisterns are devoid of microvilli. Secretory cell cytoplasm contains a Golgi apparatus, many free ribosomes, rough endoplasmic reticulum (RER), two types of granules (speckled and dense), and mitochondria. Speckled granules are partially filled with fairly large particles and are found in association with the Golgi apparatus. They also surround canaliculi into which they empty. Dense granules are packed with very small particles, have a gray homogeneous appearance, and are scattered throughout the cytoplasm. Mitochondria containing matrix granules tend to scatter throughout the cytoplasm but are concentrated around canaliculi.