Biomedical subjects

R Ruffoli

Publications and source records attributed to R Ruffoli.

21 records · Page 2Linked to original sources

PubMed1991

[Tubular structures revealed using tannic acid on the surface of the epithelium of the tympanic cavity of the chicken].

We have studied the ultrastructure of the epithelium lining the tympanic cavity of chicken, using two embedding techniques. In certain cases, the epithelium was minced in Karnovsky fixative, post-fixed in osmium, dehydrated and embedded in Epon, following the usual methods. No morphologically detectable structures were seen at the level of the epithelium surface. In other cases, the epithelium was immersed in Karnovsky fixative and subsequently in glutaraldehyde (1%) to which, however, tannic acid (1%) was added; the specimens were then osmicated, dehydrated with Epon and embedded in polar Epon mix. This method was sometimes used to study the alveolar surfactant, since this makes it possible to preserve its phospholipid fraction. The epithelium, in this way, is seen to be covered by an electron-dense material made up of thin, intertwined tubules. The hypothesis formulated is that the tubules are related to the presence of surfactant substances.

Animals↗

PubMedDate not supplied

Ultrastructural localization of NADPH-diaphorase activity in the endothelial cells of human nasal respiratory mucosa.

The cavernous sinuses are the most peculiar feature of the nasal angioarchitecture, due to their ability to retain a large quantity of blood in reply to a variety of topical and systemic stimuli. Recently, nitric oxide (NO) has seemed to be crucially involved in the nasal vascular regulation. The distribution of NO-synthase (NOS), the enzyme that catalyzes the formation of NO, was studied in the endothelium of nasal blood vessels by the ultracytochemical detection of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) enzymic activity. The endothelium of the cavernous sinuses appeared strongly positive, whereas the endothelium of arterioles was occasionally labeled. The endothelial cells of capillaries and venules were found to be NADPH-d negative. The strong enzymic activity observed in the cavernous sinuses suggests a major role of NO in the capacitance vessels compared to the resistance vessels. The hypothesis of a reciprocal inhibition between the NOS enzymic pathways present in the respiratory epithelium and in the endothelium of cavernous sinuses is put forward. The nasal disorders characterized by anomalous vasomotility and vascular permeability could be caused in part by the irregular control of these complex interactions.

Adolescent↗

PubMedDate not supplied

Ultrastructural demonstration of the NADPH-diaphorase activity in peritubular myoid cells and fibroblasts of the lamina propria of the mouse seminiferous tubules.

The NOS-related NADPH-diaphorase activity was studied by transmission electron microscopy in the peritubular myoid cells and fibroblasts of normal mouse testis. The reaction product was observed on the membranes of the endoplasmic reticulum, on the Golgi apparatus and nuclear envelope. The peritubular myoid cells and fibroblasts showed similar ultracytochemical features; the intensity of the enzymatic reaction was suggestive of an important role of the NOS/cGMP enzymatic system in these cells. Some hypotheses on the role of NO in the peritubular myoid cells and fibroblasts are proposed.

Animals↗