Nuclear triiodothyronine receptor expression is regulated by axon-Schwann cell contact.

Thyroid hormones, which play an important role in the development and regeneration of the nervous system, require the presence of specific nuclear T3 receptors (NT3R). In this study we provide evidence that NT3R expression by Schwann cells was up-regulated in response to a loss of axonal contact in vitro and in vivo. In dorsal root ganglia explant cultures, Schwann cells which accompanied axons (nerve fibres) were devoid of NT3R. When Schwann cells were orphaned from axon contact by axon transection, all the nuclei of these cells displayed NT3R immunoreactivity. Similar results were obtained in situ; in adult rat sciatic nerve, Schwann cells which ensheathed healthy axons never expressed NT3R immunoreactivity. After sciatic nerve transection in vivo the nuclei of Schwann cells deprived of axonal contact displayed a clear NT3R immunoreaction.

Non-contact assessment of waist circumference: will tape measurements become progressively obsolete?

Waist circumference (WC) is a key variable to assess in health management as it is a proxy of abdominal fat mass and a surrogate marker of cardiometabolic disease risk, including the metabolic syndrome. Recently, a portable non-contact device calculating WC (ViScan) has been developed, which hence allows the tracking of WC independently of the inter-investigators error. We compared WC values obtained with this device with WC measured by simple non-stretchable tape in 74 adults of varying body mass indices (range 17-39 kg/m(2)). The correlation between the two methods was very high (r=0.97, P<0.0001) and the reproducibility (precision) assessed with a rigid phantom was excellent (<1 cm, coefficient of variability<1%). The instrument constitutes a potentially valuable tool for longitudinal surveys and comparative international studies, which require simple but precise measurements of WC in order to track the effect of subtle changes on various health outcomes.

Analog circuit for real-time computation of respiratory mechanical impedance in sleep studies

The aim of this work was to develop a low-cost circuit for real-time analog computation of the respiratory mechanical impedance in sleep studies. The practical performance of the circuit was tested in six patients with obstructive sleep apnea. The impedance signal provided by the analog circuit was compared with the impedance calculated simultaneously with a conventional computerized system. We concluded that the low-cost analog circuit developed could be a useful tool for facilitating the real-time assessment of airway obstruction in routine sleep studies.

Dusproportionate Minority Contact in Iowa's Juvenile Justice System, April 2006

This report was developed to provide summary information to allow state agency staff, practitioners and juvenile justice system officials to access a specific section of Iowa’s Three Year Plan. It includes the Disproportionate Minority Contact (DMC) section of Iowa’s 2006 Juvenile Justice and Delinquency Prevention Act formula grant Three-Year Plan. The complete Three Year Plan serves as Iowa’s application for Juvenile Justice and Delinquency Prevention Act formula grant funding.

Moving from a Mechanical Microkeratome to a Femtosecond Laser for LASIK to Correct Astigmatic Patients: Clinical Outcomes of a Retrospective, Consecutive, Comparative Study.

Background: To evaluate outcomes after optimized laser in situ keratomileusis (LASIK) for astigmatism correction with flap created by a mechanical microkeratome or a femtosecond laser. Patients and Methods: In this retrospective study, a total of 102 eyes of 71 consecutive patients were enrolled undergoing optimized LASIK treatments using the Allegretto laser system (WaveLight Laser Technologie AG, Erlangen, Germany). A mechanical microkeratome for flap creation was used (One Use, Moria®) in 46 eyes (31 patients, spherical equivalent [SE] -4.44 D ± 2.4) and a femtosecond laser was used (LDV, Ziemer®) in 56 eyes (40 patients, spherical equivalent [SE] -3.07 D ± 3.3). The two groups were matched for inclusion criteria and were operated under similar conditions by the same surgeon. Results: Overall, the preoperative spherical equivalent was -9.5 diopters (D) to +3.37 D; the preoperative manifest astigmatism was between -1.5 D and -3.5 D. At 6 months postoperatively, the mean postoperative uncorrected distance visual acuity (UDVA) was 0.93 ± 0.17 (range 0.4 to 1.2) in the Moria group and 1.0 ± 0.21 (range 0.6 to 1.6) in the Femto group, which was statistically significant (p = 0.003). Comparing the cylinder power there was a statistical difference between the two groups (p = 0.0015). Conclusions: This study shows that the method of flap creation has a significant impact on postoperative astigmatism with a significantly better postoperative UDVA in the Femto group. These findings suggest that the femtosecond laser provides a better platform for LASIK treatment of astigmatism than the commonly used microkeratome.

Mechanical ventilation in the newborn; a simplified approach. Part 1: Intermittent positive pressure ventilation.

Positive pressure ventilation (PPV) is a frequent intervention in the neonatal intensive care unit. This article is directed towards paediatricians in training and attempts to cover the basics of PPV without being too technical. To do so we have employed an extensive use of graphics to illustrate the underlying principles.

Assessing the Functionality and Biocompatibility of a Wireless Contact Lens Sensor for 24 hour-intraocular Pressure Monitoring in Volunteers: Preliminary Results

Purpose: In vitro studies in porcine eyes have demonstrated a good correlation between induced intraocular pressure variations and corneal curvature changes, using a contact lens with an embedded microfabricated strain gauge. Continuous 24 hour-intraocular pressure (IOP) monitoring to detect large diurnal fluctuation is currently an unmet clinical need. The aims of this study is to evaluate precision of signal transmission and biocompatibility of 24 hour contact lens sensor wear (SENSIMED Triggerfish®) in humans. Methods: After full eye examination in 10 healthy volunteers, a 8.7 mm radius contact lens sensor and an orbital bandage containing a loop antenna were applied and connected to a portable recorder. Best corrected visual acuity and position, lubrication status and mobility of the sensor were assessed after 5 and 30 minutes, 4, 7 and 24 hours. Subjective comfort was scored and activities documented in a logbook. After sensor removal full eye examination was repeated, and the registration signal studied. Results: The comfort score was high and did not fluctuate significantly, except at the 7 hour-visit. The mobility of the contact lens was minimal but its lubrication remained good. Best corrected visual acuity was significantly reduced during the sensor wear and immediately after its removal. Three patients developed mild corneal staining. In all but one participant we obtained a registration IOP curve with visible ocular pulse amplitude. Conclusions: This 24 hour-trial confirmed the functionality and biocompatibility of SENSIMED Triggerfish® wireless contact lens sensor for IOP-fluctuation monitoring in volunteers. Further studies with a range of different contact lens sensor radii are indicated.

Anthropogenic disturbance as a driver of microspatial and microhabitat segregation of cytotypes of Centaurea stoebe and cytotype interactions in secondary contact zones.

BACKGROUND AND AIMS: In a mixed-ploidy population, strong frequency-dependent mating will lead to the elimination of the less common cytotype, unless prezygotic barriers enhance assortative mating. However, such barriers favouring cytotype coexistence have only rarely been explored. Here, an assessment is made of the mechanisms involved in formation of mixed-ploidy populations and coexistence of diploid plants and their closely related allotetraploid derivates from the Centaurea stoebe complex (Asteraceae). METHODS: An investigation was made of microspatial and microhabitat distribution, life-history and fitness traits, flowering phenology, genetic relatedness of cytotypes and intercytotype gene flow (cpDNA and microsatellites) in six mixed-ploidy populations in Central Europe. KEY RESULTS: Diploids and tetraploids were genetically differentiated, thus corroborating the secondary origin of contact zones. The cytotypes were spatially segregated at all sites studied, with tetraploids colonizing preferentially drier and open microhabitats created by human-induced disturbances. Conversely, they were rare in more natural microsites and microsites with denser vegetation despite their superior persistence ability (polycarpic life cycle). The seed set of tetraploid plants was strongly influenced by their frequency in mixed-ploidy populations. Triploid hybrids originated from bidirectional hybridizations were extremely rare and almost completely sterile, indicating a strong postzygotic barrier between cytotypes. CONCLUSIONS: The findings suggest that tetraploids are later immigrants into already established diploid populations and that anthropogenic activities creating open niches favouring propagule introductions were the major factor shaping the non-random distribution and habitat segregation of cytotypes at fine spatial scale. Establishment and spread of tetraploids was further facilitated by their superior persistence through the perennial life cycle. The results highlight the importance of non-adaptive spatio-temporal processes in explaining microhabitat and microspatial segregation of cytotypes.

Inferring epidemic contact structure from phylogenetic trees.

Contact structure is believed to have a large impact on epidemic spreading and consequently using networks to model such contact structure continues to gain interest in epidemiology. However, detailed knowledge of the exact contact structure underlying real epidemics is limited. Here we address the question whether the structure of the contact network leaves a detectable genetic fingerprint in the pathogen population. To this end we compare phylogenies generated by disease outbreaks in simulated populations with different types of contact networks. We find that the shape of these phylogenies strongly depends on contact structure. In particular, measures of tree imbalance allow us to quantify to what extent the contact structure underlying an epidemic deviates from a null model contact network and illustrate this in the case of random mixing. Using a phylogeny from the Swiss HIV epidemic, we show that this epidemic has a significantly more unbalanced tree than would be expected from random mixing.

Three mechanical weed control techniques in spring cereals

Selostus: Kolme viljojen mekaanista rikkakasvintorjuntamentelmää

Mechanical ventilation in the newborn; a simplified approach. Part 2: High-frequency ventilation.

High frequency oscillatory ventilation (HFOV) is becoming an increasingly popular intervention in the neonatal intensive care unit. This article will attempt to explain the principles of HFOV. It is inherently more difficult to become skilled in this technique than in other forms of mechanical ventilation, so caution is warranted.

Le "neurally adjusted ventilatory assist": vers une révolution de la ventilation mécanique [Neurally adjusted ventilatory assist: a revolution of mechanical ventilation?].

Neurally adjusted ventilatory assist or NAVA is a new assisted ventilatory mode which, in comparison with pressure support, leads to improved patient-ventilator synchrony and a more variable ventilatory pattern. It also improves arterial oxygenation. With NAVA, the electrical activity of the diaphragm is recorded through a nasogastric tube equipped with electrodes. This electrical activity is then used to pilot the ventilator. With NAVA, the patient's respiratory pattern controls the ventilator's timing of triggering and cycling as well as the magnitude of pressurization, which is proportional to inspiratory demand. The effect of NAVA on patient outcome remains to be determined through well-designed prospective studies.

Secretory IgA and intestinal epithelial cells at the interface between homeostasis regulation and protection against infection

RESUME DESTINE A UN LARGE PUBLICL'intestin est le siège d'intenses agressions de la part de l'ensemble des aliments ingérés, de bactéries agressives dites pathogènes mais également de bactéries dites commensales peuplant naturellement les surfaces intestinales muqueuses. Pour faire face, notre organisme arbore de nombreux niveaux de protections tant physiques, chimiques, mécaniques mais aussi immunitaires. La présence d'un type particulier de cellules, les cellules épithéliales (IEC) assurant une protection physique, ainsi que la production d'anticorps spécialisés par le système immunitaire appelés immunoglobulines sécrétoires A (SlgA) servent conjointement de première ligne de défense contre ces agressions externes. Néanmoins, comment le dialogue s'articule entre ces deux partenaires reste incomplet.Nous avons donc décidé de mimer ces interactions en modélisant les surfaces muqueuses par une monocouche de cellules différenciées en laboratoire. Des souches bactériennes isolées de l'intestin humain seules ou associées à des SlgA non-spécifiques ont été mises au contact de ce modèle cellulaire nous permettant de conclure quant à la présence effective d'une modulation du dialogue bactérie/lEC impliquant une activation de la réponse cellulaire vers un état de tolérance mutuelle. De façon surprenante, nous avons par ailleurs mis en évidence un type d'interaction nouveau entre ces anticorps et ces bactéries. Une étude biochimique nous a permis de détailler un nouveau rôle des SlgA médié par les sucres présents à leur surface dans le maintien d'une relation pacifique avec les commensaux perpétuellement présents, relations qualifiées d'homésostase intestinale.Le rôle protecteur des SlgA a par ailleurs été abordé pour avoir une meilleure appréhension de leur impact au niveau cellulaire lors d'infection par Shigella flexneri, bactérie causant la Shigellose, diarrhée sanglante responsable de la mort de plus d'un million de personnes chaque année. Basée sur le même modèle cellulaire, cette étude nous a permis de démontrer une nouvelle entrée de ce pathogène directement via les IEC. La présence d'anticorps spécifiques à la surface des bactéries restreint leur champs d'action contre les cibles intracellulaires identifiées que sont les filaments soutenant le squelette de la cellule, les fibres d'actine ainsi que les jonctions serrées, réseaux de protéines clés des interactions entre cellules. Cette ouverture au niveau cellulaire apporte un nouvel élan quant à la compréhension du rôle protecteur des SlgA lors d'attaques de l'intestin, protection semblant dépendante d'une agrégation des bactéries.Pour finir, nous avons mis en évidence la détection directe par les cellules de la présence d'anticorps libres dans l'intestin ajoutant une nouvelle réplique dans le dialogue complexe entre ces deux piliers de l'équilibre intestinal que sont les SlgA et les cellules épithéliales.RESUMELa muqueuse intestinale est dotée d'un réseau complexe de protections physico-chimiques, mécaniques ou immunologiques. Associées à un système immunitaire omniprésent, les cellules épithéliales intestinales {IEC) bordant la lumière intestinale ont la double tâche de protéger l'intérieur de l'organisme stérile contre l'invasion et la dissémination d'agents pathogènes, et de maintenir une relation pacifique avec la flore intestinale, rôles également joués par les immunoglobulines sécrétoires A (SlgA), anticorps les plus abondamment présents à la surface des muqueuses. Tant les IEC que les SlgA sont ainsi décrites comme convergeant vers le même objectif ; néanmoins, les rouages de leurs interactions restent largement inconnus.Pour répondre à cette question, des monocouches épithéliales reconstituées in vitro ont été incubées avec des souches commensales telles que des Lactobacillus ou des Bifodobacteria, seules ou complexées avec des SlgA non-spécifiques, nous permettant de décrypter l'influence des SlgA sur la détection des bactéries par les IEC, favorisant l'adhésion bactérienne et la cohésion cellulaire, augmentant l'activation de la voie NF-κΒ ainsi que la sécrétion de la cytokine thymic stromal lymphopoietin contrairement à celle de médiateurs pro-inflammatoires qui reste inchangée. Par ailleurs, une interaction Fab-indépendante est suggérée dans l'interaction SlgA/bactéries. Comme une interaction de faible affinité a été décrite comme prenant naturellement place au niveau de l'intestin, nous avons donc disséqué les mécanismes sous- jacents en utilisant un large spectre de bactérie associés à des protéines soit recombinantes soit isolées à partir de colostrum, mettant en évidence un rôle crucial des N-glycanes présents sur la pièce sécrétoire et soulignant une nouvelle propriété des SlgA dans l'homéostase intestinale.Intrinsèquement liés aux caractéristiques des SlgA, nous nous sommes également focalisés sur leur rôle protecteur lors d'infection par l'enteropathogène Shigella flexneri reproduites in vitro sur des monocouches polarisées. Nous avons tout d'abord démontré une nouvelle porte d'entrée pour ce pathogène directement via les IEC. L'agrégation des bactéries par les SlgA confère aux cellules une meilleure résistance à l'infection, retardant croissance bactérienne et entrée cellulaire, affectant par ailleurs leur capacité à cibler le cytosquelette et les jonctions serrées. La formation de tels cargos détectés de façon biaisée par les IEC apparaît comme une explication plausible au maintien de la cohésion cellulaire médiée par les SlgA.Enfin, le retrotransport des SlgA à travers les IEC a été abordé soulignant une participation active de ces cellules dans la détection de l'environnement extérieur, les impliquant possiblement dans l'activation d'un état muqueux stable.Conjointement, ces résultats indiquent que les SlgA représentent l'un des éléments-clés à la surface de la muqueuse et soulignent la complexité du dialogue établi avec l'épithélium en vue du maintien d'un fragile équilibre intestinal.ABSTRACTThe intestinal mucosa is endowed with a complex protective network melting physiochemical, mechanical and immunological features. Beyond the ubiquitous intestinal immune system, intestinal epithelial cells (IEC) lying the mucosal surfaces have also the dual task to protect the sterile core against invasion and dissemination of pathogens, and maintain a peaceful relationship with commensal microorganisms, aims also achieved by the presence of high amounts of secretory immunoglobulins A (SlgA), the most abundant immunoglobulin present at mucosal surfaces. Both IEC and SlgA are thus described to converge toward the same goal but how their interplay is orchestrated is largely unknown.To address this question, in vitro reconstituted IEC monolayers were first apically incubated with commensal bacteria such as Lactobacillus or Bifodobacteria strains either alone or in complexes with non-specific SlgA. Favoring the bacterial adhesion and cellular cohesion, SlgA impacts on the cellular sensing of bacteria, increasing NF-κΒ activation, and leading to cytokine releases restricted to the thymic stromal lymphopoietin and unaffected expression of pro-inflammatory mediators. Of main interest, bacterial recognition by SlgA suggested a Fab-independent interaction. As this low affinity, called natural coating occurs in the intestine, we further dissected the underlying mechanisms using a larger spectrum of commensal strains associated with recombinant as well as colostrum-derived proteins and pinpointed a crucial role of N-glycans of the secretory component, emphasizing an underestimated role of carbohydrates and another properties of SlgA in mediating intestinal homeostasis.As mucosal protection is also anchored in SlgA and IEC features, we focused on the cellular role of SlgA. Using IEC apical infection by the enteropathogen Shigella flexneri, we have first demonstrated a new gate of entry for this pathogen directly via IEC. Specific SlgA bacterial aggregation conferred to the cells a better resistance to infection, delaying bacterial growth and cellular entry, affecting their ability to damage both the cytoskeleton and the tight junctions. Formation of such big cargos differentially detected by IEC appears as a plausible explanation sustaining at the cellular level the antibody-mediated mucosal protection.Finally, SlgA retrotransport across IEC has been tackled stressing an active IEC sensing of the external environment possibly involved in the steady-state mucosal activation.All together, these results indicate that SlgA represents one of the pivotal elements at mucosal surfaces highlighting the complexity of the dialogue established with the epithelium sustaining the fragile intestinal balance.The Intestinal mucosa is endowed with a complex protective network melting physiochemical, mechanical and immunological features. Beyond the ubiquitous intestinal immune system, intestinal epithelial cells (IEC) lying the mucosal surfaces have also the dual task to protect the sterile core against invasion and dissemination of pathogens, and maintain a peaceful relationship with commensal microorganisms, aims also achieved by the presence of high amounts of secretory immunoglobulins A (SlgA), the most abundant immunoglobulin present at mucosal surfaces. Both IEC and SlgA are thus described to converge toward the same goal but how their interplay is orchestrated is largely unknown.To address this question, in vitro reconstituted IEC monolayers were first apically incubated with commensal bacteria such as Lactobacillus or Bifodobacteria strains either alone or in complexes with non-specific SlgA. Favoring the bacterial adhesion and cellular cohesion, SlgA impacts on the cellular sensing of bacteria, increasing NF-κΒ activation, and leading to cytokine releases restricted to the thymic stromal lymphopoietin and unaffected expression of pro-inflammatory mediators. Of main interest, bacterial recognition by SlgA suggested a Fab-independent interaction. As this low affinity, called natural coating occurs in the intestine, we further dissected the underlying mechanisms using a larger spectrum of commensal strains associated with recombinant as well as colostrum-derived proteins and pinpointed a crucial role of N-glycans of the secretory component, emphasizing an underestimated role of carbohydrates and another properties of SlgA in mediating intestinal homeostasis.As mucosal protection is also anchored in SlgA and IEC features, we focused on the cellular role of SlgA. Using IEC apical infection by the enteropathogen Shigella flexneri, we have first demonstrated a new gate of entry for this pathogen directly via IEC. Specific SlgA bacterial aggregation conferred to the cells a better resistance to infection, delaying bacterial growth and cellular entry, affecting their ability to damage both the cytoskeleton and the tight junctions. Formation of such big cargos differentially detected by IEC appears as a plausible explanation sustaining at the cellular level the antibody-mediated mucosal protection.Finally, SlgA retrotransport across IEC has been tackled stressing an active IEC sensing of the external environment possibly involved in the steady-state mucosal activation.All together, these results indicate that SlgA represents one of the pivotal elements at mucosal surfaces highlighting the complexity of the dialogue established with the epithelium sustaining the fragile intestinal balance.