Demonstration of catecholaminergic neurons in rat retina by fluorescence histochemistry on cryostat sections]

A fluorescence histochemical technique using glyoxylic acid and cryostat sections has been worked out to visualize the dopamine-containing neurons of the retina. It allows the demonstration of catecholaminergic junctional cells and alloganglion cells, classically described. Moreover, the observation of some fluorescent fibers in the external zone of the inner nuclear layer, in contact with the outer plexiform, suggests the presence of catecholamine-containing interplexiform cells, in the Rat retina.     

Distribution of organic and inorganic carbon in tissues containing calcium carbonate by secondary ion emission microanalysis]

The differences of emissivity of secondary ions at masses 12 (C+ and C-), 24 (C2-) and 26 (C2H2- or CN-) of organic moitie and CO3Ca of semi thin sections of egg shell of quail allow the distinction between organic and inorganic carbon on images obtained with Secondary Ion Mass Spectroscopy. There differences of emissivity do not correspond only to the difference of concentration but to the difference of ionic yield. The emissivity at mass 26 (C2H2- or CN-) is higher than those obtained at mass 24 (C2-) in glycoproteinic material (rich in Nitrogen) and lower in the embedding material (Araldite, poor in Nitrogen). This result indicates that the ion present at mass 26 could by CN- rather than C2H2-.     

Adaptation of the deoxyglucose method to the cellular level: histologic preparation of the central nervous system for high resolution radioautography]

Vascular perfusion of all products required for primary fixation, postfixation, dehydration and embedding of nervous tissue in Epon permits radio-autographic detection of radioactivity accumulated in the central nervous system after intravenous injection of [3H]deoxyglucose. This histological technique should allow application of the deoxyglucose method at cellular if not subcellular level, since a high proportion of the tracer appears to be retained in situ in specimens adequately preserved for light and electron microscope radio-autography.     

Immune phenomena during experimental schistosomiasis in the rat: role of specific and non specific factors]

Partial immunity to Schistosoma mansoni in the rat can be obtained by injection of a bilharzian antigen together with Freund's complete adjuvant. The results are the same no matter what form of the parasite is used (infecting cercariae or adult). This immunity is the result of both specific and non-specific mechanisms, as is proved by the fact that a lesser but still quite clear degree of resistance to infestation can be obtained by injection of Freund's adjuvant alone.     

Demonstration by the Fink-Heimer impregnating method of a ventral mesencephalic-locus coeruleus projection in the rat

Summary With the help of the Fink-Heimer technique, we have demonstrated a ventral mesencephalic-locus coeruleus projection in the rat after lesions located in the region of the dopaminergic A10 and serotonergic B8 cells. This finding could help our understanding of the functional role of these structures.     

Electron microscopic study of secretion of chylomicrons in the rat by enterocytes in lymphatic capillary lumen]

Rats were fed on a 20% fat diet; 30 min. or 2 hrs later intestinal jejunal cells were fixed in situ; samples were taken and processed for subsequent study by electron microscopy. Chylomicron secretion was followed from the enterocyte to the lymphatic capillary lumen. Chylomicrons entered the lamina propria through breaks in the basal membrane at intercellular space level. Their penetration into the lymphatic capillary lumen occurred through the open junctions of the endothelial cells normally kept closed by desmosomal formations.     

Robust regression in biological assay: application to the evaluation of alternative experimental techniques

Robust Huber type regression and testing of linear hypotheses are adapted to statistical analysis of parallel line and slope ratio assays. They are applied in the evaluation of results of several experiments carried out in order to compare and validate alternatives to animal experimentation based on embryo and cell cultures. Computational procedures necessary for the application of robust methods of analysis used the conversational statistical package ROBSYS. Special commands for the analysis of parallel line and slope ratio assays have been added to ROBSYS.     

Robust regression in biological assay: application to the evaluation of alternative experimental techniques

Summary Robust Huber type regression and testing of linear hypotheses are adapted to statistical analysis of parallel line and slope ratio assays. They are applied in the evaluation of results of several experiments carried out in order to compare and validate alternatives to animal experimentation based on embryo and cell cultures. Computational procedures necessary for the application of robust methods of analysis used the conversational statistical package ROBSYS. Special commands for the analysis of parallel line and slope ratio assays have been added to ROBSYS.     

Visualization of opiate receptors in the locus coeruleus of rats: high resolution radioautography after administration of a tritiated met-enkephalin analog]

Opiate receptor sites were visualized by high resolution radioautography in the locus coeruleus of the Rat following intraventricular injection of the met-enkephalin analogue FK 33-824 tritiated with a high specific activity (3H-FK). After administration of a tracer dose of 3H-FK, more than 75% of the radioactivity detected in the locus coeruleus is specifically bound to opiate receptor sites. These are distributed both between and inside neuronal perikarya. After administration of 3H-FK at high concentration, electron microscope radioautography shows the presence of specific opiate binding sites at the level of axo-somatic and axo-dendritic synaptic junctions. These synaptic binding sites could correspond to receptor sites for endogenous enkephalins.     

Genetic and histological aspects of stomach lesions induced by systemic injection of phenylbutazone in the rat

Summary Roman high-avoidance (RHA/Verh) rats, food-deprived (F-D) for 5 days, had higher stomach lesion scores than did F-D Roman low-avoidance (RLA/Verh) rats. F-D RLA/Verh rats which were injected i.p. with phenylbutazone (PBZ) 24 h before examination, however, had higher scores than did PBZ-treated, F-D RHA/-Verh rats. Histologically, extensive edema and cellular infiltration (including numerous erythrocytes) were seen below lesions, in the submucosa, denoting vascular damage. An attenuating influence of food on the ulcerogenic effects of PBZ, which were much more severe in F-D than in fed rats was also indicated.The authors thank K. Bättig and J. R. Martin for their assistance during the planning stages, B. Hauser, A. Waldvogel and P. Wild of the Veterinary Medical Faculty of Zurich University for preparing the histological sections and for the photography, and P. Elsinger for technical help.     

Genetic and histological aspects of stomach lesions induced by systemic injection of phenylbutazone in the rat

Roman high-avoidance (RHA/Verh) rats, food-deprived (F-D) for 5 days, had higher stomach lesion scores than did F-D Roman low-avoidance (RLA/Verh) rats. F-D RLA/Verh rats which were injected i.p. with phenylbutazone (PBZ) 24 h before examination, however, had higher scores than did PBZ-treated, F-D RHA/Verh rats. Histologically, extensive edema and cellular infiltration (including numerous erythrocytes) were seen below the lesions, in the submucosa, denoting vascular damage. An attenuating influence of food on the ulcerogenic effects of PBZ, which were much more severe in F-D than in fed rats, was also indicated.     

Demonstration by stereological methods of pre-prophase doubling of the number of ribosomes in Ehrlich tumor cells]

Homogeneous populations of G1, S or G2 Ehrlich tumor cells are analysed by stereological methods at the ultrastructural level. This analysis demonstrates that the number of cytoplasmic ribosomes is doubled before the prophase.     

Functional study of the rat olfactory bulb by a 14C-2-deoxyglucose autoradiographic technic]

The autoradiographic method has been used in the Rat to map active regions in the olfactory bulb after a pulse of 14C-2-deoxyglucose with electrical stimulation of the lateral olfactory tract. The highest optical densities were found at the external plexiform, mitral, internal plexiform and granular layers; the lowest was found in the glomerular layer.