S Noubissie | PubMed Health

PubMed2003

Dynamics of solitary blood waves in arteries with prostheses.

We analyze the behavior of blood waves interacting with a prosthesis following the Yomosa nonlinear wave theory extended to include the spatial variation of the arterial radius and wall rigidity. When the prosthesis is short or when its characteristics are close to those of the host artery, the amplitude of the blood solitary wave increases just proximal to the prosthesis and then decreases to a magnitude smaller than the normal value in a healthy vessel. In the presence of an extended prosthesis, we derive the reflection and transmission coefficients at the interfaces, and we thereby obtain the optimal characteristics for an ideal prosthesis. Our results agree qualitatively with known experimental and numerical studies.

Animals↗

PubMedDate not supplied

[Malaria and surgery: which prophylaxis?].

The authors report on a study carried out at the Centre Hospitalier universitaire (University Hospital) of Yaounde (Cameroon). Such a study aimed at to check interest of systematic malaria chemoprophylaxis during the peri-operative phase in general surgery. 61 patients were divided in two groups by random allocation with and without quinine chemoprophylaxis. All of them were monitored clinically and parasitologically during the peri-operative phase. Results show that in both groups, only patients already positive before surgical intervention presented clinical malaria signs, biologically confirmed; malaria attack was more frequent and more severe in the group without quinine. No malaria attack was observed in patients of both groups in which thick smear was negative in pre-operative phase. The authors suggest that any patient during the pre-operative phase, be tested to find out Plasmodium falciparum. If the test is positive, so chemoprophylaxis with quinine be prescribed. But such a medication is valuable only in urban endemic zone.

Adult↗