[Twinkling artifact on Doppler US: clinical presentations]. / L'artefact de scintillement en écho-Doppler et situations cliniques.

Twinkling artifact characterized by a rapidly fluctuating mixture of Doppler signals occurs behind a strongly reflecting granular interface such as urinary tract stones or gallstones. It may occurs in association with several clinical situations, and may sometimes be helpful for diagnosis while it may sometimes be a pitfall that must be recognized by the sonographer. After reviewing the technical nature of this artifact, several cases will be presented to illustrate the advantages and pitfalls related to this artifact.

[Hepatic Epithelioid hemangioendothelioma: a rare liver tumor]. / L'hémangioendothéliome épithélioïde du foie: une tumeur hépatique rare.

Epithelioid hemangioendothelioma of the liver is a rare primary malignant tumor of vascular origin. It most frequently occurs in middle age adults and clinical findings are non-specific. Histological diagnosis may be difficult to achieve with lesions containing a large myxoid component, and immunohistochemical staining is required. A few imaging features may suggest the correct diagnosis, and radiologists should be familiar with these findings. We will illustrate the potential role of PET-CT at the time of initial presentation. Prognosis is variable and optimal management is based on a case by case analysis, ranging from clinical and imaging follow-up to liver transplantation.

[Arterial spin labeling: state of the art]. / Etat de l'art sur le Marquage de Spin Artériel ou ASL.

UNLABELLED: Arterial spin labeling (ASL) perfusion MR imaging is a technique by which water from circulating arterial blood is magnetically labeled and acts as a diffusible tracer allowing non-invasive measurement of cerebral blood flow. In this paper, the technique and current applications in neuroimaging will be reviewed. CURRENT STATUS: First, the technical principles of ASL will be reviewed and both available techniques (continuous and pulsed ASL) explained. A review of the literature will demonstrate advances with the techniques of ASL and its clinical impact. Clinical research involves normal volunteers and patients with ischemic and tumoral pathologies. CONCLUSION: Recent technical advances have improved the sensitivity of ASL perfusion MR imaging. The routine clinical use of ASL at 3.0 Tesla should increase over the next few years.

Dopamine versus norepinephrine: is one better?

Dopamine and norepinephrine are widely used as first line agents to correct hypotension in patients with acute circulatory failure. There has been considerable debate in recent years as to whether one is better than the other. Both drugs can increase blood pressure in shock states, although norepinephrine is more powerful. Dopamine can increase cardiac output more than norepinephrine, and in addition to the increase in global blood flow, has the potential advantage of increasing renal and hepatosplanchnic blood flow. However, dopamine has potentially detrimental effects on the release of pituitary hormones and especially prolactin, although the clinical relevance of these effects is unclear. Observational studies have provided conflicting results regarding the effects of these two drugs on outcomes, and results from a recently completed randomized controlled trial are eagerly waited.

[Severe hypokalemia after holidays return]. / Hypokaliémie sévère au retour de vacances.

A 52-year old man is referred to our institution for hypertension (190/90 mmHg) and lower limb edema. An initial blood sample reveals severe hypokalemia (1.58 mEq/l) associated with metabolic alkalosis (pH: 7.63; total bicarbonates: 47.7 mEq/I), rhabdomyolysis (CPK: 1.776 UI/I) and ECG modifications. Primary aldosteronism is suspected and further diagnostic procedures are performed. A urine sample shows inappropriate potassium elimination associated with both low plasmatic renin and aldosterone levels, orienting the diagnosis toward a case of pseudohyperaldosteronism. A more detailed history reveals daily consumption of more than half a liter of licorice-based aperitif during the holiday period. This case illustrates the paramount importance of a detective-like questioning and reminds the physiopathologic role of glycyrrhetinic acid as a cause of hyperaldosteronism.

Elaboration of new formulations to remove micropollutants in MSWI flue gas.

This study consists in identifying and testing potential inorganic substitutes to carbon based materials commonly used as adsorbents for the removal of organic pollutants such as dioxins and furans released from Municipal Solid Waste Incinerators (MSWI). Although carbon materials enable to reach the current regulation in terms of dioxins and furans emissions, they exhibit a potential auto ignition risk when present in hot flue gases. Here, the adsorption potential of carbon based products is compared to the one of some inorganic materials. Chlorobenzene was chosen as a reference molecule to compare the removal performance of the different adsorbents. This comparison was based on the determination of the adsorption energies derived from temperature programmed desorption (TPD) experiments. In the first part of this study, five inorganic materials were selected according to their chlorobenzene adsorption performance compared to those of carbon based products currently used to remove micropollutants from MSWI flue gases. In the second part of the study, the influence of the inlet concentration of adsorbate on the adsorption potential of sorbents is investigated. Actually, the organic compound concentration was decreased in order to be closer to those met in MSWI. Furthermore, the adsorption experiments were performed with other adsorbates whose molecular mass or chlorine content are higher. Thanks to these adsorption results a new organic free formulation has been proposed for the removal of micropollutants. Tests carried out on an industrial scale, demonstrated that this product enables to reach the current norm concerning dioxins and furans emissions.

A gas chromatographic separation for the h and C stable isotope ratio determination of coal compounds.

A new, completely automated gas chromatography technique has been developed to separate the different gaseous compounds produced during underground coal gasification for their (13)C/(12)C and D/H isotope ratio measurements. The technique was designed for separation and collection of H(2), CO, CO(2), H(2)O, H(2)S, CH(4), and heavier hydrocarbons. These gaseous compounds are perfectly separated by the gas-phase chromatograph and quantitatively sent to seven combustion and collection lines. H(2), CO, CH(4), and heavier hydrocarbons are quantitatively oxidized to CO(2) and/or H(2)O. The isotopic analyses are performed by the sealed-tube method. The zinc method is used for reduction of both water and H(2)S to hydrogen for D/H analysis. Including all preparation steps, the reproducibility of isotope abundance values, for a quantity higher than or equal to 0.1 mL of individual components in a mixture (5 mL of gases being initially injected in the gas chromatograph), is ±0.1‰ for δ(13)C(PDB) and ±6‰ for δD(SMOW).

Dietary fat affects weight loss and adiposity during energy restriction in rats.

This study examined the effect of dietary fat during food restriction on weight loss, body composition, and adipose tissue lipoprotein lipase activity (ATLPL). Rats previously fed a high-fat diet were divided into four groups. One group served as baseline controls. The other three groups were fed diets of 12%, 28%, or 45% fat, restricted (R) in amounts to equal 75% of their previous ad libitum energy intake. After 10 wk, body weight loss and reduction of adiposity were significantly less in the 45%-R group compared with the 12%-R group (weight P < 0.05; adiposity P < 0.01). Rats fed restricted amounts of the high-fat diet (45%-R group) retained adiposity equivalent to baseline control rats. ATLPL activity was increased in the 45%-R group compared with baseline control rats. Further studies are needed in humans, but these results suggest that body composition will not be normalized with reduction of energy intake unless dietary fat is also reduced.

[Association of idiopathic hemochromatosis and tardive cutaneous porphyria]. / Association d'une hémochromatose idiopathique et d'une porphyrie cutanée tardive.

Porphyria cutanea tarda is a disorder of porphyrin metabolism that results from a deficiency of uroporphyrinogen decarboxylase, resulting in a characteristic pattern of porphyrin excretion. Elevated serum iron values are frequently observed among patients with porphyria cutanea tarda. The hypothesis has been advanced that a hemochromatosis allele is implicated in the clinical manifestation of porphyria cutanea tarda. We report the case of a patient suffering from both idiopathic hemochromatosis and porphyria cutanea tarda. The data of the medical literature concerning such an association are discussed.

Adult respiratory distress syndrome and miliary tuberculosis.

Miliary tuberculosis presenting as fatal adult respiratory distress syndrome is reported in a 69-year-old man. Idiopathic thrombocytopenic purpura led to splenectomy 2 years before admission and was currently treated with corticosteroids. Moderate dyspnea, a dry cough and weight loss were presenting clinical features, preceding respiratory failure by only a few days. In these patients with atypical symptoms early diagnosis and prompt antituberculous chemotherapy are life-saving. The diagnosis of miliary tuberculosis should be systematically considered in ARDS of unknown origin.