Adipose-Derived Stem Cells in the Treatment of Perianal Fistulas in Crohn’s Disease: Rationale,Clinical Results and Perspectives

Between 20 to 25% of Crohn’s disease (CD) patients suffer from perianal fistulas, a marker of disease severity. Seton drainage combined with anti-TNFα can result in closure of the fistula in 70 to 75% of patients. For the remaining 25% of patients there is room for in situ injection of autologous or allogenic mesenchymal stem cells such as adipose-derived stem/stromal cells (ADSCs). ADSCs exert their effects on tissues and effector cells through paracrine phenomena, including the secretome and extracellular vesicles. They display anti-inflammatory, anti-apoptotic, pro-angiogenic, proliferative, and immunomodulatory properties, and a homing within the damaged tissue. They also have immuno-evasive properties allowing a clinical allogeneic approach. Numerous clinical trials have been conducted that demonstrate a complete cure rate of anoperineal fistulas in CD ranging from 46 to 90% of cases after in situ injection of autologous or allogenic ADSCs. A pivotal phase III-controlled trial using allogenic ADSCs (Alofisel^®) demonstrated that prolonged clinical and radiological remission can be obtained in nearly 60% of cases with a good safety profile. Future studies should be conducted for a better knowledge of the local effect of ADSCs as well as for a standardization in terms of the number of injections and associated procedures.     

In Search of 'Cultures' for Multicultural Education

Various patently incompatible explications of culture are presented, in order to demonstrate the range of understandings and extent of disagreement surrounding this concept within the field of cultural studies. There is clearly absence of consensus among experts on what this elusive concept is or what it entails. Social constructions of culture are then presented in order to create an understanding of the way in which distorted conceptualisations of culture have come to be sedimented in and permeative of the social consciousness. A consequence of this process is that social groups have developed and retained limited understandings of the cultures of others, because these cultures are apprehended and represented in abstracted forms, which are associated with a limited range of cultural signifiers. The actual relationships of disparity that exist between people positioned at the opposite ends of the cultural scale are then confronted within the political dimension of multiculturalism, in order to argue that multiculturalism is tainted by its concealment of its political agenda, which is the homogenisation of what are assumed to be inferior cultural forms, through the processes of assimilation and acculturation. It is concluded that multicultural education, as it is currently practiced, has conceptual, political and practical barriers that it cannot traverse. Its consequences are more deleterious than beneficial to society and it should therefore be discontinued as an educational enterprise.     

DIELECTRIC PROPERTIES OF GLASSES AT ULTRA-HIGH FREQUENCIES AND THEIR RELATION TO COMPOSITION *

The dielectric constants and dielectric losses of 104 glasses of a wide range of compositions have been measured at 10-cm. and 3-cm. wave lengths by the resonating cavity method (3000 and 10,000 megacycles, respectively). By correlating the power-factor data with the compositions of these glasses, the authors propose a qualitative explanation of the mechanisms producing energy absorption and dielectric losses in the microwave range. These mechanisms are determined by the nature of the bonds joining atoms and ions in the randomly oriented atomic networks of glasses. The rigid and continuous networks of SiO₂ and B₂O₃ glasses are relatively transparent to centimeter wave lengths. Energy absorption and dielectric losses are low. Addition of network-modifying oxides yields glasses of greater energy absorption owing to the oscillation of the interstitial ions thus introduced. Increasing the content of any one of these ions in a glass results in higher losses while the coexistence of a variety of these ions generally results in lower losses. Alkali ions in glasses give rise to high losses, which increase as the number of ions present increases. Glasses containing a combination of alkalis show lower losses than the equivalent compositions with only one alkali. Divalent ions do not contribute as much to losses as alkalis, but high power factors are shown by glasses with high BaO or PbO contents. Using combinations of these oxides instead of only one, slight reductions in power factor are effected. Dissimilar interstitial ions interact in ultra-high frequency fields with the result that energy absorption is reduced. The losses of high-lead glasses are thus reduced by alkalis and, on the other hand, the presence of RO lowers the losses of glasses containing R₂O. Alumina increases the dielectric losses of glasses in much the same manner as other network modifiers.     

HERSCHEL—PACS Bolometer Arrays for Submillimeter Ground-Based Telescopes

The Herschel Space Observatory will carry onboard a new kind of bolometric architecture for the PACS (Photodetector Array Camera and Spectrometer) submillimeter photometer. These new generation CCD-like multiplexed bolometer arrays are buttable and enable the conception of large fully sampled focal planes either for space or for ground-based telescopes. We present here some development for ground-based applications in the context of the ARTEMIS (ARchitecture de bolomètres pour des TElescopes sub-MIllimétriques au Sol) project. We have developed an electro-thermal numerical model that simulates the performances of these semiconducting bolometers under specific ground-based conditions (different wavelengths and background powers for example). This model permits to determine the optimal parameters for each condition and shows that the bolometers can be background limited in each atmospheric transmission window between 200 and 450 microns. We also describe the optical system that provides a high optical efficiency in each submillimeter atmospheric window. Astronomical observations made with a prototype on the APEX telescope are presented.     

A Thermesthesiometer?An Instrument for Burn Hazard Measurement

Surface temperature measurement alone is insufficient to establish the hazard to the human of contact with a hot or cold object. A metal surface is more likely to cause thermal injury than a plastic surface at the same temperature. An instrument equipped with a measuring probe has been developed for indicating the temperature that would be experienced if human contact were made with the hot surface in question. The correct value of interface contact temperature can be read for a selected contact time without knowing the composition or temperature of the heated material under test.     

Relationships between ability requirements and human errors in job tasks.

This article describes a program of research investigating the relations between abilities required to perform job tasks and human error probabilities while performing these tasks. Study 1, using objectively derived human errors made in performing Air Force job tasks, evaluated an ability-requirements classification methodology and found that error rates were related to the numbers, types, and levels of different abilities required. In Study 2, subject matter expert panels used the methodology to identify the ability requirements of tasks in 2 different jobs found in each of 2 types of nuclear power plants. This study, using a task-anchored scale of human error probability, replicated the findings of Study 1, identified 2 ability requirements that cross-validated in predicting task-error probabilities across both jobs and plants, and identified other abilities specific to error probabilities in each job. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Divergent Immunomodulatory Effects of Short Chain Fatty Acids and Medium Chain Fatty Acids

Fatty acids are derived from diet and fermentative processes by the intestinal flora. Two to five carbon chain fatty acids, termed short chain fatty acids (SCFA) are increasingly recognized to play a role in intestinal homeostasis. However, the characteristics of slightly longer 6 to 10 carbon, medium chain fatty acids (MCFA), derived primarily from diet, are less understood. Here, we demonstrated that SCFA and MCFA have divergent immunomodulatory propensities. SCFA down-attenuated host pro-inflammatory IL-1β, IL-6, and TNFα response predominantly through the TLR4 pathway, whereas MCFA augmented inflammation through TLR2. Butyric (C4) and decanoic (C10) acid displayed most potent modulatory effects within the SCFA and MCFA, respectively. Reduction in TRAF3, IRF3 and TRAF6 expression were observed with butyric acid. Decanoic acid induced up-regulation of GPR84 and PPARγ and altered HIF-1α/HIF-2α ratio. These variant immune characteristics of the fatty acids which differ by just several carbon atoms may be attributable to their origins, with SCFA being primarily endogenous and playing a physiological role, and MCFA exogenously from the diet.