Is ICP solid or fluid? In vitro biomechanical model using a fluid-saturated gel.

Intracranial pressure is mainly considered to be hydrostatic pressure, but observations demonstrated that ICP is heterogeneous within brain suggesting the presence of a solid pressure. Brain tissue is a biphasic material composed of solid and fluid phases. We hypothesized that in a saturated porous model, fluid and solid phases yielded two pressures. Our brain model was 0.5% agar gel. A quasi static compression was applied using a tensile machine. Pressures were gauged within the gel using two different microsensors. One sensor (A) has an open sensitive area measuring the total pressure, whereas the other sensor (B) has a pressure-sensitive area design that gauges mainly the fluid pressure. There was very good agreement between the pressure applied to the gel and the pressure inside the gel measured with sensor A. However, sensor B systematically underestimated the pressure in the gel. We assume that sensor A gauged the total pressure, which is the sum of the pore fluid pressure and mechanical stress, whereas sensor B probably measured only the fluid pressure. The difference between the two sensors reflects the solid part of the total pressure. ICP has to be considered to be the sum of fluid pressure and solid stress.

[Spiruline as a food supplement in case of infant malnutrition in Burkina-Faso]. / La spiruline comme complément alimentaire dans la malnutrition du nourrisson au Burkina-Faso.

BACKGROUND: Spiruline, a microscopic algae with nutritious quality was put forward as food supplement to fight malnutrition in infant. POPULATION AND METHODS: To assess its effectiveness, a survey was carried out among children with malnutrition whose Z-score was <2 for their age, in the Koudougou province, Burkina-Faso. Within five centers, three groups were defined at randomization: group 1 with usual nutritional rehabilitation program, group 2 as above + 5 g x d(-1) of spiruline, group 3 as above + spiruline + fish. 182 children, aged three months - three years, were originally involved. Six died (3.3%) and 11 hospitalised were excluded; the study was carried out on 165 children and lasted three months. Judging criteria were: length per aged, weight for length group evolution and the corresponding Z-score at 60 et 90 days. RESULTS: At the inclusion, children were aged 14.6 months on average and weighed 6.7 kg (Z-score of -3.2 weight/age) with a length of 71.4 cm (-2.0 Z-score length/age) and weight for length of 0.093 (-2.5 Z-score). 9.4% had oedema. There were no noticeable differences between the three groups as to weight gain, length gain, weight for length gain. CONCLUSION: A 5 g x d(-1) spiruline dose does not bring any benefit over 90 days, compared to traditional renutrition. Furthermore, at the moment, it is costly, and the battle against infant malnutrition cannot be based on one single element, such as a wonder drug, but on a national or local policy based on training, education, economical aid, and nutritional rehabilitation centers and infection treatment.