A Procedure to Measure the in-Situ Hygrothermal Behavior of Earth Walls

Rammed earth is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities and its mechanical behavior. Both of these properties are known to strongly depend on the amount of water contained in wall pores and its evolution. Thus the aim of this paper is to present a procedure to measure this key parameter in rammed earth or cob walls by using two types of probes operating on the Time Domain Reflectometry (TDR) principle. A calibration procedure for the probes requiring solely four parameters is described. This calibration procedure is then used to monitor the hygrothermal behavior of a rammed earth wall (1.5 m × 1 m × 0.5 m), instrumented by six probes during its manufacture, and submitted to insulated, natural convection and forced convection conditions. These measurements underline the robustness of the calibration procedure over a large range of water content, even if the wall is submitted to quite important temperature variations. They also emphasize the importance of gravity on water content heterogeneity when the saturation is high, as well as the role of liquid-to-vapor phase change on the thermal behavior.     

Prevalence of Thoracic Aortic Aneurysms in Patients with Degenerative Abdominal Aortic Aneurysms: Results from the Prospective ACTA Study

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AC133+ umbilical cord blood progenitors demonstrate rapid self-renewal and low apoptosis

Umbilical cord blood (UCB) provides immediate access to haemopoietic stem/progenitor cells (HSPC) but low cell number restricts use in full adult bone marrow reconstitution. This study investigated early ex vivo expansion kinetics of UCB AC133+ cells (2-4 x 10(4)/ml), mononuclear cells (MNC, 1-2 x 10(6)/ml) and AC133negative cells (AC133(neg), 2-4 x 10(4)/ml) in stroma-free 8 d liquid culture (fetal bovine serum-supplemented Iscove's-modified Dulbecco's medium (IMDM) with either 'K36EG'[c-Kit ligand, interleukin 3 (IL-3), IL-6, erythropoietin, granulocyte colony-stimulating factor] or 'TPOFL' (thrombopoietin, Flt-3 ligand). Cell enumeration, apoptosis assay and AC133/CD34/CD38 antigen immunophenotyping were performed at d 0, 3, 5 and 8. All three cell populations went through a proliferation lag phase between d 3 and d 5. AC133+ cells recovered better from lag phase with significantly higher fold increase (FI) when compared with MNC and AC133(neg) populations (K36EG FI: 15.04 +/- 5.46; TPOFL FI: 8.59 +/- 2.92, P < 0.05). After 8 d, populations lacking AC133+ cells were significantly more inclined to undergo apoptosis under proliferative conditions (P < 0.01). Also, when compared with K36EG, 8 d TPOFL-expanded AC133+ cells encompassed a significantly higher percentage of AC133+ and CD34+ early HSPC (K36EG: 20.50 +/- 2.36; TPOFL: 47.00 +/- 7.69; P < 0.05). In conclusion, TPOFL synergism demonstrated the potential for AC133+ HSPC ex vivo expansion inducing self-renewal, early HSPC maintenance and promoting cell survival status.     

IFIH1-GCA-KCNH7 locus is not associated with genetic susceptibility to multiple sclerosis in French patients

A recent investigation reported, for the first time, an association between variants in the IFIH1-GCA-KCNH7 locus and multiple sclerosis (MS). We sought to replicate this genetic association in MS with a new independent MS cohort composed of French Caucasian MS trio families. The two most significant IFIH1 single nucleotide polymorphisms, rs1990760 and rs2068330, reported as involved in MS susceptibility, were genotyped in 591 French Caucasian MS trio families, and analyzed using the transmission/disequilibrium test. No association with MS was found (rs1990760, P=0.45 and rs2068330, P=0.27). Similarly, no significant association was detected after stratification for HLA-DRB1^*1501 carriers. Reasons that may explain this discrepancy between the original report and our study are discussed.     

Interest of alpha2-adrenergic agonists and antagonists in clinical practice: background, facts and perspectives

The family of alpha(2)-adrenergic receptors (alpha(2)-ARs) comprises three subtypes which are each endowed with specific functions. alpha(2)-agonists and alpha(2)-antagonists are part of the clinician armamentarium since several decades; however, none of the compounds so far available is subtype selective. For long, clonidine and yohimbine have been used for the treatment of hypertension and impotence respectively, but both have been superseded by newer drugs. This review attempts, by a comprehensive analysis of the literature, to cover the present clinical use and the potential therapeutic interest of alpha(2)-agonists or antagonists. From the clinical data, it is concluded that, with the exception of a few particular situations, alpha(2)-agonists are only of limited utility as a monotherapy. By contrast, they offer several powerful advantages when used in adjunctive therapy. In perioperative settings, alpha(2)-agonists are extremely valuable adjuncts to anesthetics and analgesics for the induction of anxiolysis, maintenance of sedation, management of pain and prevention of shivering. In the ophthalmic clinic, they are used to lower intra-ocular pressure during laser surgery of the eye. As a daily medication, alpha(2)-agonists are also of interest for the treatment of glaucoma, muscle spasticity, opiate withdrawal, and behavior disorders. The alpha(2)-antagonists are useful antidotes for reversing the threatening effects of agonist overdose, but currently there are very few indications. New applications are under investigation, and new molecules with more refined subtype-selectivity may emerge, so the clinical utility of both alpha(2)-agonists and antagonists will undoubtedly expand in the future.     

Apoptotic effects of imidazo[1,2-a]pyrazine derivatives in the human Dami cell line

cAMP-elevating agents like phosphodiesterase inhibitors and purines have been shown to induce apoptosis. In the present work we have studied the effects of imidazo[1,2-a]pyrazine derivatives with a purine-like structure: PAB13 (6-bromo-8-(methylamino)imidazo[1,2-a]pyrazine), PAB15 (6-bromo-8-(ethylamino)imidazo[1,2-a]pyrazine), PAB23 (3-bromo-8-(methylamino)imidazo[1,2-a]pyrazine) on the growth of the Dami cell line in comparison to that of adenosine. The growth effect of PAB13, PAB15 and PAB23 was investigated in relation to their phosphodiesterase-inhibitory action and their activity on purinoceptors. Inhibition in cell growth was up to 71.0%, 76.3% and 89.7% for PAB23, PAB13 and PAB15, respectively and 100% for adenosine. Cell viability was affected in a concentration-dependent manner by PAB13, PAB15 and adenosine, with a correlation between growth inhibition and cytotoxicity. These effects of imidazo[1,2-a]pyrazine derivatives were found to be unrelated to an action on purinoceptors, but rather appear quantitatively linked to their ability in inducing apoptosis through their cAMP-increasing and phosphodiesterase-inhibitory potency.     

In Vitro and In Vivo Evaluation of the Thermal Patterns and Lesions of Catheter Ablation with a Microwave Monopole Antenna

BACKGROUND: Radiofrequency (RF) catheter ablation is an effective treatment for supraventricular tachycardia. The effectiveness of the technique is at times limited by the small lesion size produced by RF energy delivery. Previous reports have indicated that microwave energy is capable of producing a larger volume of heated tissue than radiofrequency energy, raising the possibility that microwave energy may offer a potential alternative energy source to radiofrequency for the substrate ablation of certain arrhythmias such as ventricular tachycardia or atrial flutter. METHODS: The present study evaluated the thermal profiles of a monopole microwave antenna delivering energy at 2.45 GHz frequency in a phantom tissue-equivalent material with dielectric and thermal properties similar to myocardium. In addition, microwave catheter ablations were performed in vivo in the ventricles of goats prior to the examination of the lesions. RESULTS: The measured thermal profiles in the phantom revealed that the antenna is capable of producing heating to a temperature associated with myocardial necrosis to a controllable depth that can be more than 8 mm, while the endocardial temperature is maintained relatively low. The ablation volume is significantly reduced but is still effective when there is only a partial contact between the antenna and the tissue surface. In vivo studies on goat models confirmed that the monopole antenna can produce a deep transmural lesion in the left ventricle without causing coagulation or charring on the endocardial surface.     

The cytokine-dependent MUTZ-3 cell line as an in vitro model for the screening of contact sensitizers

Langerhans cells (LC) are key mediators of contact allergenicity in the skin. However, no in vitro methods exist which are based on the activation process of LC to predict the sensitization potential of chemicals. In this study, we have evaluated the performances of MUTZ-3, a cytokine-dependent human monocytic cell line, in its response to sensitizers. First, we compared undifferentiated MUTZ-3 cells with several standard human cells such as THP-1, KG-1, HL-60, K-562, and U-937 in their response to the strong sensitizer DNCB and the irritant SDS by monitoring the expression levels of HLA-DR, CD54, and CD86 by flow cytometry. Only MUTZ-3 and THP-1 cells show a strong and specific response to sensitizer, while other cell lines showed very variable responses. Then, we tested MUTZ-3 cells against a wider panel of sensitizers and irritants on a broader spectrum of cell surface markers (HLA-DR, CD40, CD54, CD80, CD86, B7-H1, B7-H2, B7-DC). Of these markers, CD86 proved to be the most reliable since it detected all sensitizers, including benzocaine, a classical false negative in local lymph node assay (LLNA) but not irritants. We confirmed the MUTZ-3 response to DNCB by real-time PCR analysis. Taken together, our data suggest that undifferentiated MUTZ-3 cells may represent a valuable in vitro model for the screening of potential sensitizers.