Numerical simulation of left ventricular assist device implantations: comparing the ascending and the descending aorta cannulations.

In this work we present numerical simulations of continuous flow left ventricle assist device implantation with the aim of comparing difference in flow rates and pressure patterns depending on the location of the anastomosis and the rotational speed of the device. Despite the fact that the descending aorta anastomosis approach is less invasive, since it does not require a sternotomy and a cardiopulmonary bypass, its benefits are still controversial. Moreover, the device rotational speed should be correctly chosen to avoid anomalous flow rates and pressure distribution in specific location of the cardiovascular tree. With the aim of assessing the differences between these two approaches and device rotational speed in terms of flow rate and pressure waveforms, we set up numerical simulations of network of one-dimensional models where we account for the presence of an outflow cannula anastomosed to different locations of the aorta. Then, we use the resulting network to compare the results of the two different cannulations for several stages of heart failure and different rotational speed of the device. The inflow boundary data for the heart and the cannulas are obtained from a lumped parameters model of the entire circulatory system with an assist device, which is validated with clinical data. The results show that ascending and descending aorta cannulations lead to similar waveforms and mean flow rate in all the considered cases. Moreover, regardless of the anastomosis region, the rotational speed of the device has an important impact on wave profiles; this effect is more pronounced at high RPM.

Partial molecular characterization of Sm8, a tegumental antigen of Schistosoma mansoni

Sm8 is a major tegumental antigen of Schistosoma mansoni. The partial cDNA was isolated and analyzed. Sequence analysis revealed transmembrane compatible hydrophobic domains and a putative leucine zipper pattern. The mRNA and the protein are predominantly expressed in adult worms.

Exposure to tobacco smoke before and after a partial smoking ban in prison: indoors air quality measures

Although exposure to secondhand smoke (SHS) is reportedly high in prison, few studies have measured this in the prison environment, and none have done so in Europe. We measured two indicators of SHS exposure (particulate matter PM10 and nicotine) in fixed locations before (2009) and after (2010) introduction of a partial smoking ban in a Swiss prison. Access to smoking cessation support was available to detainees throughout the study. Objectives To measure SHS before and after the introduction of a partial smoking ban. Methods Assessment of particulate matter PM10 (suspended microparticles of 10 μm) and nicotine in ambient air, collected by real-time aerosol monitor and nicotine monitoring devices. Results The authors observed a significant improvement of nicotine concentrations in the air after the introduction of the smoking ban (before: 7.0 μg/m(3), after: 2.1 μg/m(3), difference 4.9 μg/m(3), 95% CI for difference: 0.52 to 9.8, p=0.03) but not in particulate matter PM10 (before: 0.11 mg/m(3), after: 0.06 mg/m(3), difference 0.06 mg/m(3), 95% CI for difference of means: -0.07 to 0.19, p=0.30). Conclusions The partial smoking ban was followed by a decrease in nicotine concentrations in ambient air. These improvements can be attributed to the introduction of the smoking ban since no other policy change occurred during this period. Although this shows that concentrations of SHS decreased significantly, protection was still incomplete and further action is necessary to improve indoor air quality.

Cre recombinase-mediated inactivation of H-2Dd transgene expression: evidence for partial missing self-recognition by Ly49A NK cells.

We have established H-2D(d)-transgenic (Tg) mice, in which H-2D(d) expression can be extinguished by Cre recombinase-mediated deletion of an essential portion of the transgene (Tg). NK cells adapted to the expression of the H-2D(d) Tg in H-2(b) mice and acquired reactivity to cells lacking H-2D(d), both in vivo and in vitro. H-2D(d)-Tg mice crossed to mice harboring an Mx-Cre Tg resulted in mosaic H-2D(d) expression. That abrogated NK cell reactivity to cells lacking D(d). In D(d) single Tg mice it is the Ly49A+ NK cell subset that reacts to cells lacking D(d), because the inhibitory Ly49A receptor is no longer engaged by its D(d) ligand. In contrast, Ly49A+ NK cells from D(d) x MxCre double Tg mice were unable to react to D(d)-negative cells. These Ly49A+ NK cells retained reactivity to target cells that were completely devoid of MHC class I molecules, suggesting that they were not anergic. Variegated D(d) expression thus impacts specifically missing D(d) but not globally missing class I reactivity by Ly49A+ NK cells. We propose that the absence of D(d) from some host cells results in the acquisition of only partial missing self-reactivity.

Carcinoembryonic antigen (CEA): demonstration of a partial identity between CEA and a normal glycoprotein.

The carcinoembryonic antigen of the human digestive tract (CEA), described by Gold as a glycoprotein specific for digestive carcinomatous and foetal tissues, was found to have common antigenic determinants with a glycoprotein of smaller size extracted from normal adult tissues. This observation suggests that only a part of the CEA molecule carries the onco-foetal specificity. It also has practical implications regarding the radioimmunoassay for CEA used for the diagnosis of certain carcinomas.

Leishmania braziliensis: partial control of experimental infection by interleukin-12 p40 deficient mice

Resistance to infection by Leishmania major has been associated with the development of a Th1 type response that is dependent on the presence of interleukin 12 (IL-12). In this work the involvement of this cytokine in the response to infection by L. braziliensis, a less virulent species in the mouse model, was evaluated. Our results show that while interferon (IFN-g) deficient (-/-) mice inoculated L. braziliensis develop severe uncontrolled lesions, chronic lesions that remained under control up to 12 weeks of infection were observed in IL-12p40 -/- mice. IL 12p40 -/- mice had fewer parasites in their lesions than IFN-g-/- mice. Lymph node cells from IL-12p40 -/- were capable of producing low but consistent levels of IFN-g suggestive of its involvement in parasite control. Furthermore, as opposed to previous reports on L. major-infected animals, no switch to a Th2 response was observed in IL-12p40 -/- infected with L. braziliensis.

Decreased expression of peroxisome proliferator-activated receptor alpha and liver fatty acid binding protein after partial hepatectomy of rats and mice.

BACKGROUND AIMS: Marked changes in metabolism, including liver steatosis and hypoglycemia, occur after partial hepatectomy. Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a nuclear hormone receptor that is activated by fatty acids and involved in hepatic fatty acid metabolism and regeneration. Liver fatty acid binding protein (LFABP) is an abundant protein in liver cytosol whose expression is regulated by PPAR alpha. It is involved in fatty acid uptake and diffusion and in PPAR alpha signaling. The aim of this study was to investigate the expression of PPAR alpha and LFABP during liver regeneration. METHODS: Male Sprague-Dawley rats and male C57 Bl/6 mice were subjected to 2/3 hepatectomy and LFABP and PPAR alpha mRNA and protein levels were measured at different time points after surgery. The effect of partial hepatectomy was followed during 48 h in rats and 72 h in mice. RESULTS: PPAR alpha mRNA and protein levels were decreased 26 h after hepatectomy of rats. The LFABP mRNA and protein levels paralleled those of PPAR alpha and were also decreased 26 h after hepatectomy. In mice, the mRNA level was decreased after 36 and 72 h after hepatectomy. In this case, LFABP mRNA levels decreased more slowly after partial hepatectomy than in rats. CONCLUSIONS: A marked decrease in PPAR alpha expression may be important for changed gene expression, e.g. LFABP, and metabolic changes, such as hypoglycemia, during liver regeneration.

Essays in equilibrium asset pricing

This thesis consists of four essays in equilibrium asset pricing. The main topic is investors' heterogeneity: I investigates the equilibrium implications for the financial markets when investors have different attitudes toward risk. The first chapter studies why expected risk and remuneration on the aggregate market are negatively related, even if intuition and standard theory suggest a positive relation. I show that the negative trade-off can obtain in equilibrium if investors' beliefs about economic fundamentals are procyclically biased and the market Sharpe ratio is countercyclical. I verify that such conditions hold in the real markets and I find empirical support for the risk-return dynamics predicted by the model. The second chapter consists of two essays. The first essay studies how het¬erogeneity in risk preferences interacts with other sources of heterogeneity and how this affects asset prices in equilibrium. Using perceived macroeconomic un¬certainty as source of heterogeneity, the model helps to explain some patterns of financial returns, even if heterogeneity is small as suggested by survey data. The second essay determines conditions such that equilibrium prices have analytical solutions when investors have heterogeneous risk attitudes and macroeconomic fundamentals feature latent uncertainty. This approach provides additional in-sights to the previous literature where models require numerical solutions. The third chapter studies why equity claims (i.e. assets paying a single future dividend) feature premia and risk decreasing with the horizon, even if standard models imply the opposite shape. I show that labor relations helps to explain the puzzle. When workers have bargaining power to exploit partial income insurance within the firm, wages are smoother and dividends are riskier than in a standard economy. Distributional risk among workers and shareholders provides a rationale to the equity short-term risk, which leads to downward sloping term structures of premia and risk for equity claim. Résumé Cette thèse se compose de quatre essais dans l'évaluation des actifs d'équilibre. Le sujet principal est l'hétérogénéité des investisseurs: J'étudie les implications d'équilibre pour les marchés financiers où les investisseurs ont des attitudes différentes face au risque. Le première chapitre étudie pourquoi attendus risque et la rémunération sur le marché global sont liées négativement, même si l'intuition et la théorie standard suggèrent une relation positive. Je montre que le compromis négatif peut obtenir en équilibre si les croyances des investisseurs sur les fondamentaux économiques sont procyclique biaisées et le ratio de Sharpe du marché est anticyclique. Je vérifier que ces conditions sont réalisées dans les marchés réels et je trouve un appui empirique à la dynamique risque-rendement prédites par le modèle. Le deuxième chapitre se compose de deux essais. Le première essai étudie com¬ment hétérogénéité dans les préférences de risque inter agit avec d'autres sources d'hétérogénéité et comment cela affecte les prix des actifs en équilibre. Utili¬sation de l'incertitude macroéconomique perù comme source d'hétérogénéité, le modèle permet d'expliquer certaines tendances de rendements financiers, même si l'hétérogénéité est faible comme suggéré par les données d'enquête. Le deuxième essai détermine des conditions telles que les prix d'équilibre disposer de solutions analytiques lorsque les investisseurs ont des attitudes des risques hétérogènes et les fondamentaux macroéconomiques disposent d'incertitude latente. Cette approche fournit un éclairage supplémentaire à la littérature antérieure où les modèles nécessitent des solutions numériques. Le troisième chapitre étudie pourquoi les equity-claims (actifs que paient un seul dividende futur) ont les primes et le risque décroissante avec l'horizon, mme si les modèles standards impliquent la forme opposée. Je montre que les relations de travail contribue à expliquer l'énigme. Lorsque les travailleurs ont le pouvoir de négociation d'exploiter assurance revenu partiel dans l'entreprise, les salaires sont plus lisses et les dividendes sont plus risqués que dans une économie standard. Risque de répartition entre les travailleurs et les actionnaires fournit une justification à le risque à court terme, ce qui conduit à des term-structures en pente descendante des primes et des risques pour les equity-claims.

Proposal of a new classification for optimising outcome assessment following partial cricotracheal resections in severe pediatric subglottic stenosis.

OBJECTIVE: Creation of a patent subglottic airway after partial cricotracheal resection (PCTR) may not always result in successful decannulation due to associated parameters such as co-morbidity and/or glottic involvement. We classified patients after incorporating these additional parameters into the original Myer-Cotton classification to assess whether this could better predict the outcome measures after PCTR. METHODS: One hundred children with Myer-Cotton grade III or IV subglottic stenosis who underwent PCTR between 1978 and 2008 were identified from a prospectively collected database. The patients were classified into four groups based on the association of co-morbidity and/or glottic involvement. Delay in decannulation, revision open surgery and rates of decannulation were the outcome measures compared between the groups. RESULTS: There were 68 children with Myer-Cotton grade III and 32 children with grade IV stenosis. Based on the new classification, there were 36 children with isolated SGS, 31 with associated co-morbidity, 19 with associated glottic involvement and 14 children with both co-morbidity and glottic involvement. A trend towards less optimal results was noticed with the association of co-morbidity and/or glottic involvement. Statistical significance was reached for maximum decannulation failure in the group with both co-morbidity and glottic involvement. Delayed decannulation significantly correlated in the group with associated glottic involvement. CONCLUSION: This new classification is relatively simple and aimed at providing more accurate and uniform prognostic information to both patients and surgeons when dealing with the whole spectrum of severe SGS.

Aluminum hydroxide associated to Schistosoma mansoni 22.6 kDa protein abrogates partial protection against experimental infection but not alter interleukin-10 production

The need to develop a vaccine against schistosomiasis led several researches and our group to investigate proteins from Schistosoma mansoni as vaccine candidates. Sm22.6 is a protein from S. mansoni that shows high identity with Sj22.6 and Sh22.6 (79 and 91%, respectively). These proteins are associated with high levels of IgE and protection to reinfection. Previously, we have shown that Sm22.6 induced a partial protection of 34.5% when used together with Freund's adjuvant and produced a Th0 type of immune response with interferon-g and interleukin-4. In this work, mice were immunized with Sm22.6 alone or with aluminum hydroxide adjuvant and high levels of IgG, IgG1, and IgG2a were measured. Unfortunately, no protection was detected. Since IL-10 is a modulating cytokine in schistosomiasis, we also observed a high level of this molecule in splenocytes of vaccinated mice. In conclusion, we did not observe the adjuvant effect of aluminum hydroxide associated with rSm22.6 in protective immunity.

Partial eating disorders among adolescents: a review.

PURPOSE: Many adolescents do not fulfill all the DSM-IV criteria's for anorexia nervosa and bulimia, but do nevertheless suffer from partial eating disorders (EDs). This review focuses on the definition, epidemiology and clinical aspects of these disorders. METHODS: Search on Medline & PsycINFO, review of websites, screening of bibliographies of articles and book chapters. RESULTS: There is still no consensus on the definition of these disorders, which cover a wide range of severity. Affected adolescents often suffer from physical and psychological problems owing to co-morbidity or as a consequence of their eating patterns: chronic constipation, dyspeptic symptoms, nausea, abdominal pain, fatigue, headaches, hypotension, menstrual dysfunction as well as dysthymia, depressive and anxiety disorders, or substance misuse and abuse. In comparison with those who are unaffected, adolescents with partial ED are at higher risk of evolving into full ED. However, most of them evolve into spontaneous remission. Adolescents with partial ED engaged, over a period of several months, in potentially unhealthy weight-control practices, suffering from intense fear of gaining weight and a disturbed body weight/image should be offered therapeutic support. CONCLUSION: Future research should focus on the exact delineation of various subtypes of clinical presentations in partial ED and on evidence-based treatment and follow-up of these various situations.

Portal vein embolization with N-butyl cyanoacrylate before partial hepatectomy in patients with hepatocellular carcinoma and underlying cirrhosis or advanced fibrosis.

PURPOSE: To describe the safety, complications, and liver regeneration associated with the left liver after embolization of the right portal vein (PV) in patients with hepatocellular carcinoma (HCC) developed in the setting of advanced liver fibrosis and cirrhosis. MATERIALS AND METHODS: Forty patients (31 men, nine women; mean age, 62 years) with HCC underwent PV embolization over a 4-year period. Embolization was performed from a left PV percutaneous access with use of n-butyl cyanoacrylate (NBCA) mixed with iodized oil. Computed tomography (CT) volumetry was performed before and 1 month after PV embolization to measure the left lobe volume as well as the functional liver ratio defined by the ratio between the left lobe and the total liver volume minus tumoral volume. PV pressure and liver enzyme levels were compared before and 1 month after the procedure and complications were registered. Factors potentially affecting regeneration (age, sex, diabetes, chemoembolization, functional liver ratio before PV embolization, and Knodell histologic score) were evaluated by one-way and stepwise regression analysis. RESULTS: PV embolization could be achieved successfully in all cases. Two patients had partial PV thrombosis on the 1-month follow-up CT and two patients developed transient ascites after PV embolization. The left lobe volume increase was 41% +/- 32% after PV embolization and the functional liver ratio increased from 28% +/- 10% to 36% +/- 10% (P < .0001). Hypertrophy of the left lobe was greater in patients with a low functional liver ratio before PV embolization and those with an F3 fibrosis score. Other factors had no influence on left lobe regeneration. CONCLUSION: PV embolization with use of NBCA is feasible in patients with advanced fibrosis and cirrhosis. Hypertrophy of the left lobe of the liver after PV embolization has a statistically significant correlation with lower functional liver ratio and lower degrees of fibrosis.