Huiles essentielles et essence de citronnier (Citrus limon (L.) Burm. f.)

Essential oils and lemon tree oil (Citrus limon (L.) Burm. f./zest) have been known about and used for a very long time, not only in cooking but also in cosmetics and in treatments. Recent studies into d-limonene, present in between 65 and 70% of these products, confirm traditional activity (anti-infective, cholagogue, anti-nausea, tonic, etc.) as well as proposing new properties (anti-cholesterolaemic, lipolytic, hypoglycaemic, ulcer protection, anxiety relief, etc.). The absence of oral toxicity of d-limonene presents a major benefit. Its use in new treatments against metabolic disorders could also be considered.     

Concentrations of Gd–BOPTA in cholestatic fatty rat livers: role of transport functions through membrane proteins

Gd–BOPTA (gadobenate dimeglumine) is a magnetic resonance (MR) contrast agent that, after i.v. administration, distributes within the extracellular space, enters rat hepatocytes through the sinusoidal transporters organic anion transporting peptides (Oatps) and is excreted unchanged into bile through the multidrug resistance‐associated protein 2 (Mrp2). It is unclear how the hepatobiliary contrast agent would accumulate in cholestatic fatty livers from obese rats with bile flow impairment. Indeed, the expression of both Oatps and Mrp2 transporters is decreased in cholestatic hepatocytes. To assess this question, we measured on‐line the hepatic concentrations of ¹⁵³Gd–BOPTA with a gamma probe placed over perfused rat livers. During the perfusion of ¹⁵³Gd–BOPTA, we obtained a similar maximal hepatic concentration in normal and fatty livers despite the decreased expression and function of membrane transporters in fatty livers. By pharmacokinetic modeling and mathematical simulations, we show how changes of transport into and out of hepatocytes modify the concentrations of ¹⁵³Gd–BOPTA within hepatocytes. Mathematical simulations help to understand how each parameter (entry into hepatocytes, bile excretion, or efflux back to sinusoids) interferes with the hepatic concentrations. The hepatic concentrations of ¹⁵³Gd–BOPTA within hepatocytes rely on the entry into hepatocytes through the sinusoidal membrane and on two paths of exit, the efflux back to sinusoids and the elimination into bile. Understanding how ¹⁵³Gd–BOPTA accumulates in hepatocytes is then complex. However, such understanding is important to analyze liver imaging with hepatobiliary contrast agents in cholestatic fatty livers. Copyright © 2012 John Wiley & Sons, Ltd.     

Reinforcement of immunity in Saimiri monkeys following immunization with irradiated sporozoites of Plasmodium vivax.

To determine the duration of immunity to Plasmodium vivax following immunization, six Saimiri sciureus boliviensis monkeys were vaccinated with irradiated sporozoites of P. vivax and challenged multiple times with sporozoites. Over a period of almost four years, complete protection from repeated challenge with infective sporozoites was demonstrated in one monkey; protection in two monkeys was obtained on eight of nine occasions, in one monkey on seven of nine occasions, in one monkey on six or nine occasions, and in one monkey on four of eight occasions. Five of six monkeys were protected against infection during the last six challenges. Inoculation with blood-stage parasites at the end of the trial indicated that all animals were susceptible to infection. These results suggest that protection against sporozoite challenge may be strongly reinforced by subsequent exposure to viable sporozoites.     

IgG4 serology of loiasis in three villages in an endemic area of south-eastern Gabon

Human filariasis due to Loa loa differs from other filariasis in that the majority of infected subjects are without circulating microfilariae (occult loiasis). In search for alternative diagnostic methods, which do not depend on circulating microfilariae or the (rather infrequent) eye-passage of adult worms, it was shown earlier that IgG4 antibodies directed against Loa loa adult worm antigen are apparently a good marker of occult loiasis and specific with regard to the sympatrically occurring Mansonella perstans . In this study we evaluated an IgG4 antibody-based ELISA using crude extract of Loa loa microfilariae (which is easier to obtain than adult worm) to estimate the prevalence of loiasis in 3 villages in South-East Gabon. Of 222 examined individuals (80 children < 16 years, 142 adults) 44 (20%) carried Loa loa microfilariae and 170 (77%) M. perstans . Using the mean OD-value + 1 standard deviation of 9 sera from patients solely infected with M. perstans (from the Gambia, where Loa loa is not endemic) as a cut-off, 35 of the 44 microfilaraemic Loa loa patients and 2 of the 9 Gambian controls were positive. This shows that our method had a sensitivity of 80% and a specificity of 78%. Among the remaining 178 subjects who had no microfilariae of Loa loa , as many as 97 (55%) had significant levels of specific IgG4 antibodies against Loa loa , suggesting that they carried occult loiasis. The mean IgG4 level in these putatively occult loiasis patients was slightly but significantly lower than in microfilaraemic subjects ( P < 0.03). In conclusion, despite the limited sensitivity and specificity of our method, IgG4- ELISA at present is a very useful tool in estimating the real prevalence of loiasis in epidemiological surveys and at the individual level can confirm the diagnosis of L. loa amicrofilaraemic subjects with clinical signs suggesting loiasis.