Thermoelectric Properties of the Clathrate I Ba<Subscript>8</Subscript>Ge<Subscript>43</Subscript>□<Subscript>3</Subscript>

The clathrate I Ba₈Ge₄₃□₃ [space group Ia[`3]d Ia\bar{3}d , no. 230, a = 21.307(1) ?] has been synthesized as a single phase and characterized by x-ray powder diffraction and metallographic analysis. Electrical and thermal transport measurements have been performed in the temperature range of 5 K to 673 K. Ba₈Ge₄₃□₃ displays the electrical resistivity of a poor metal at low temperatures, with semiconducting-like behavior appearing above 300 K.     

Suppression of intestinal and hepatic cytochrome P4503A in murine Toxoplasma infection. Effects of N-acetylcysteine and N(G)-monomethyl-L-arginine on the hepatic suppression

1. Cytochrome P4503A (CYP3A) expression was studied in a murine model of infection. Mice were infected with a cystogenic strain of Toxoplasma gondii and microsomes were prepared for liver homogenates and jejunum villus tip enterocytes on day 10 postinfection. Total cytochrome P450 (CYP) and CYP3A were quantitated, and CYP3A activity was determined. 2. In the infected mouse, total CYP and CYP3A contents fell in the liver (-39 and - 49% respectively) and intestine (-43 and - 48 % respectively), as did the rate of metabolism of erythromycin (Ery) and cyclosporine A (CyA), two markers of CYP3A activity (-36 and -26% in the liver, -35 and -58% in the intestine). 3. To determine the mechanism(s) involved in the depression of hepatic CYP3A, infected mice were treated on day 7.5 post-infection with a monoclonal antibody raised against interferon-gamma (anti-IFN-gamma, or from days 7.5 to 10 post-infection with either N(G)-monomethyl-L-arginine (NMMA), an inhibitor of reactive nitrogen intermediates (RNI) production, or N-acetylcysteine (NAC), a reactive oxygen intermediates (ROI) scavenger. 4. Total CYP content was restored in the liver of infected mice treated with anti-IFN-gamma, but with marked interindividual variability. NAC treatment led to a recovery in the liver of total CYP content (+35 %), CYP3A content (total recovery), and the rates of Ery (+59%) and CyA (+87%) metabolism, whereas inconsistent results were obtained with NMMA. These results suggest that NAC, but probably not NMMA, partially protects hepatic CYP3A from Toxoplasma-mediated suppression in mouse.     

Depression of the N-demethylation of erythromycin, azithromycin, clarithromycin and clindamycin in murine Toxoplasma infection

The N-demethylation of macrolides was studied in a murine model of infection. Mice were infected with a cystogenic strain of Toxoplasma gondii (20 or 40 cysts/mouse) and microsomes were prepared from liver homogenates and jejunum villus tip enterocytes on day 10 post-infection. The rate of N-demethylation of the anti-Toxoplasma macrolides azithromycin, clarithromycin and clindamycin was investigated and compared to that of the macrolide erythromycin, a marker of activity of the cytochrome P-450 3A (CYP3A) mono-oxygenases. In infected mice (20 cysts/mouse), the rate of N-demethylation fell in the liver and jejunum for erythromycin (-25% and -35%, respectively), azithromycin (-12% and -10%, respectively), clarithromycin (-23% and -21%, respectively) and clindamycin (-20% and -28%, respectively). The degree of hepatic depression was more marked in mice receiving a 40-cysts burden: for erythromycin (-54%), azithromycin (-29%), clarithromycin (-49%) and clindamycin (-47%).     

Crystal Structure and High-Temperature Thermoelectric Properties of the Mo<Subscript>3−<Emphasis Type="Italic">x</Emphasis></Subscript>Ru<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Sb<Subscript>7</Subscript> Compounds

Zintl phases are currently receiving great attention for their thermoelectric potential typified by the discovery of a high ZT value in Yb₁₄MnSb₁₁-based compounds. Herein, we report on the crystallographic characterization via neutron and x-ray diffraction experiments, and on the thermoelectric properties measured in the 300 K to 1000 K temperature range, of Mo₃Sb₇ and its isostructural compounds Mo_3−x Ru _x Sb₇. Even though Mo₃Sb₇ displays rather high ZT values given its metallic character, the partial substitution of Mo by Ru substantially improves its thermoelectric properties, resulting in a ZT value of ∼0.45 at 1000 K for x = 0.8.     

Diagnosis and management of parasitic hypereosinophilia]

ETIOLOGY: Helminth infestation of the digestive tract or organ tissues is a common and curable cause of high eosinophil counts. Parasite infestation should be the number one suspect in patients with hypereosinophilia. DIAGNOSIS: Clinical signs and epidemiology are suggestive. If the patient has travelled to the tropics, one should consider both exotic and cosmopolite parasites. LABORATORY TESTS: The causal agent can sometimes be identified by direct examination of tissue samples, depending on the localization. In practice however identification may be a difficult task when the level of infestation is low or the helminth is in a larval stage. The epidemiological situation, clinical features and results of serology tests must all be considered for diagnosis. ANTIHELMINTH TREATMENT (TEST): Clinical improvement after treatment can be a criteria for positive diagnosis. Normal eosinophil counts followed later by normal serology confirms the diagnosis.