Erythrocyte flow through the interendothelial slits of the splenic venous sinus.

The flow patterns of red blood cells through the spleen are intimately linked to clearance of senescent RBCs, with clearance principally occurring within the open flow through the red pulp and slits of the venous sinus system that exists in humans, rats, and dogs. Passage through interendothelial slits (IESs) of the sinus has been shown by MacDonald et al. (Microvasc Res 33:118-134, 1987) to be mediated by the caliber, i.e., slit opening width, of these slits. IES caliber within a given slit of a given sinus section has been shown to operate in an asynchronous manner. Here, we describe a model and simulation results that demonstrate how the supporting forces exerted on the sinus by the reticular meshwork of the red pulp, combined with asymmetrical contractility of stress fibers within the endothelial cells comprising the sinus, describe this vital and intriguing behavior. These results shed light on the function of the sinus slits in species such as humans, rats, and dogs that possess sinusoidal sinuses. Instead of assuming a passive mechanical filtering mechanism of the IESs, our proposed model provides a mechanically consistent explanation for the dynamically modulated IES opening/filtering mechanism observed in vivo. The overall perspective provided is also consistent with the view that IES passage serves as a self-protective mechanism in RBC vesiculation and inclusion removal.

[Relapsing polychondritis. A case report]. / Policondrite ricorrente. Presentazione di un caso.

The authors describe a case of "relapsing polychondritis" showing that the characteristic manifestation of the disease on nasal and ear cartilage took place at a later stage than in the eye vessels, the inner ear and the trunk and valves of the aorta. The authors therefore consider the term "relapsing polychondritis" to be somewhat restrictive and claim that owing to the systemic diffusion of the disease in all vessels, R.P. should be included among systemic vasculitis diseases.

[Telethermography in the diagnosis of lumbo-sciatica syndromes]. / La teletermografia nella diagnostica delle sindromi lombo-sciatalgiche.

Thermal maps of the lumbo-sacral and gluteal regions and of the lower limbs were obtained with telethermography in 30 subjects suffering from painful lumbo-sciatic syndromes in order to assess whether there were differences of thermal index between painful and opposite side, and to evaluate the telethermographic patterns of the irritative and deficitary forms. Among 25 patients with lumbo-sciatalgia in the irritative or early stage, 16 showed hypothermia of the affected side; in three of the five patients in the deficitary stage, hyperthermia of the affected side was observed while two did not show changes of the thermal gradient. The authors stress the importance of telethermography and suggest that this method, which is not costly, non-invasive and easily reproducible, should be used to complete diagnosis of and to monitor lumbo-sciatalgic syndromes.