A receptor-like kinase mutant with absent endodermal diffusion barrier displays selective nutrient homeostasis defects.

The endodermis represents the main barrier to extracellular diffusion in plant roots, and it is central to current models of plant nutrient uptake. Despite this, little is known about the genes setting up this endodermal barrier. In this study, we report the identification and characterization of a strong barrier mutant, schengen3 (sgn3). We observe a surprising ability of the mutant to maintain nutrient homeostasis, but demonstrate a major defect in maintaining sufficient levels of the macronutrient potassium. We show that SGN3/GASSHO1 is a receptor-like kinase that is necessary for localizing CASPARIAN STRIP DOMAIN PROTEINS (CASPs)--major players of endodermal differentiation--into an uninterrupted, ring-like domain. SGN3 appears to localize into a broader band, embedding growing CASP microdomains. The discovery of SGN3 strongly advances our ability to interrogate mechanisms of plant nutrient homeostasis and provides a novel actor for localized microdomain formation at the endodermal plasma membrane.

Improved IL-2 immunotherapy by selective stimulation of IL-2 receptors on lymphocytes and endothelial cells.

IL-2 immunotherapy is an attractive treatment option for certain metastatic cancers. However, administration of IL-2 to patients can lead, by ill-defined mechanisms, to toxic adverse effects including severe pulmonary edema. Here, we show that IL-2-induced pulmonary edema is caused by direct interaction of IL-2 with functional IL-2 receptors (IL-2R) on lung endothelial cells in vivo. Treatment of mice with high-dose IL-2 led to efficient expansion of effector immune cells expressing high levels of IL-2Rbetagamma, including CD8(+) T cells and natural killer cells, which resulted in a considerable antitumor response against s.c. and pulmonary B16 melanoma nodules. However, high-dose IL-2 treatment also affected immune cell lineage marker-negative CD31(+) pulmonary endothelial cells via binding to functional alphabetagamma IL-2Rs, expressed at low to intermediate levels on these cells, thus causing pulmonary edema. Notably, IL-2-mediated pulmonary edema was abrogated by a blocking antibody to IL-2Ralpha (CD25), genetic disruption of CD25, or the use of IL-2Rbetagamma-directed IL-2/anti-IL-2 antibody complexes, thereby interfering with IL-2 binding to IL-2Ralphabetagamma(+) pulmonary endothelial cells. Moreover, IL-2/anti-IL-2 antibody complexes led to vigorous activation of IL-2Rbetagamma(+) effector immune cells, which generated a dramatic antitumor response. Thus, IL-2/anti-IL-2 antibody complexes might improve current strategies of IL-2-based tumor immunotherapy.

RF pulse concatenation for spatially selective inversion

It is shown that spatially selective inversion and saturation can be achieved by concatenation of RF pulses with lower flip angles. A concatenation rule which enables global doubling of the flip angle of any given excitation pulse applied to initial z magnetization is proposed. In this fashion, the selectivity of the single pulse is preserved, making the high selectivity achievable in the low flip-angle regime available for inversion and large flip-angle saturation purposes. The profile quality achievable with exemplary concatenated pulses is investigated in comparison with adiabatic inversion. It is verified that by using concatenated inversion in the transfer insensitive labeling technique (TILT), the MT artifact is suppressed. Copyright 2000 Academic Press.

A selective nociceptive block is not sufficient to prevent central changes after peripheral nerve injury

Background: Providing analgesia without suppressing motor or sensory function is a challenge for regional anesthesia and postoperative pain management. Resiniferatoxin (RTX), an ultrapotent agonist for transient receptor potential subtype-1 (TRPV1) can produce this selective blockade, as TRPV1 is selectively expressed on nociceptors. Futhermore, after peripheral nerve injury, spontaneous ectopic activity arises from all types of nerve fibers that can affect spinal neurons and glial cells. The goal of the present experiment is to determine whether spontaneous activity generated in C-fibers or in both A&C-fibers is required for microglia activation. Method: We applied RTX (0.01%) or bupivacaine microspheres to the sciatic nerve of rats to block the conduction of C-fibers or A&C-fibers, respectively, before spared nerve injury (SNI). Behavior was tested and all the rats were sacrificed 2 days later; immunohistochemistry was performed on their spinal cord for mitogen-activated protein kinase (MAPK) p38, bromodeoxyuridine (BrdU, marker of proliferation) and Iba1 (microglial marker). Result: At day 2 after SNI robust mechanical allodynia and p38 activation in spinal microglia were documented. There was also a substantial cell proliferation in the spinal cord, all proliferating cells (BrdU+) being microglia (Iba1+). RTX blocked heat sensitivity and produced heat hypoalgesia without affecting mechanical allodynia and motor function. Microglial proliferation and p38 activation in the spinal cord were not affected by RTX (p >0.05). In contrast, a complete sensory and motor blockade was seen with bupivacaine which also significantly inhibited p38 activation and microglial proliferation in the spinal cord (p <0.05). Conclusion: We conclude that (1) RTX can provide a selective nociceptive blockade but that (2) blocking only nociceptive fibers does not impair the development of mechanical allodynia and microglia activation. Therefore (3) if microglia activation is important for chronic pain development then specific nociceptive blockade won't be sufficient to prevent it.

A statistical methodology for the comparison of blue gel pen inks analyzed by laser desorption/ionization mass spectrometry

A statistical methodology for the objective comparison of LDI-MS mass spectra of blue gel pen inks was evaluated. Thirty-three blue gel pen inks previously studied by RAMAN were analyzed directly on the paper using both positive and negative mode. The obtained mass spectra were first compared using relative areas of selected peaks using the Pearson correlation coefficient and the Euclidean distance. Intra-variability among results from one ink and inter-variability between results from different inks were compared in order to choose a differentiation threshold minimizing the rate of false negative (i.e. avoiding false differentiation of the inks). This yielded a discriminating power of up to 77% for analysis made in the negative mode. The whole mass spectra were then compared using the same methodology, allowing for a better DP in the negative mode of 92% using the Pearson correlation on standardized data. The positive mode results generally yielded a lower differential power (DP) than the negative mode due to a higher intra-variability compared to the inter-variability in the mass spectra of the ink samples.

Selective expression of a dominant-negative form of peroxisome proliferator-activated receptor in keratinocytes leads to impaired epidermal healing.

Many nuclear hormone receptors are involved in the regulation of skin homeostasis. However, their role in the epithelial compartment of the skin in stress situations, such as skin healing, has not been addressed yet. The healing of a skin wound after an injury involves three major cell types: immune cells, which are recruited to the wound bed; dermal fibroblasts; and epidermal and hair follicle keratinocytes. Our previous studies have revealed important but nonredundant roles of PPARalpha and beta/delta in the reparation of the skin after a mechanical injury in the adult mouse. However, the mesenchymal or epithelial cellular compartment in which PPARalpha and beta/delta play a role could not be determined in the null mice used, which have a germ line PPAR gene invalidation. In the present work, the role of PPARalpha was studied in keratinocytes, using transgenic mice that express a PPARalpha mutant with dominant-negative (dn) activity specifically in keratinocytes. This dn PPARalpha lacks the last 13 C terminus amino acids, binds to a PPARalpha agonist, but is unable to release the nuclear receptor corepressor and to recruit the coactivator p300. When selectively expressed in keratinocytes of transgenic mice, dn PPARalphaDelta13 causes a delay in the healing of skin wounds, accompanied by an exacerbated inflammation. This phenotype, which is similar to that observed in PPARalpha null mice, strongly suggests that during skin healing, PPARalpha is required in keratinocytes rather than in other cell types.

Comparison of fundus autofluorescence between fundus camera (Topcon) and confocal scanning laser ophthalmoscope (HRA) in various pathologies

Purpose: To investigate the differences between Fundus Camera (Topcon TRC-50X) and Confocal Scanning Laser Ophthalmoscope (Heidelberg retina angiogram (HRA)) on the fundus autofluorescence (FAF) imaging (resolution and FAF characteristics). Methods: 105 eyes of 56 patients with various retinal diseases underwent FAF imaging with HRA (488nm exciter/500nm barrier filter) before fluorescein angiography (FFA) and Topcon Fundus Camera (580nm exciter/695nm barrier filter) before and after FFA. The quality of the FAF images was compared for their resolution and analysed for the influence of fixation stability and cataracts. Hypo-and hyper-FAF behaviour was analysed for the healthy disc, healthy fovea, and a variety of pathological features. Results: HRA images were found to be of superior resolution in 18, while Topcon images were estimated superior in 29 eyes. No difference was found in 58 eyes. Both poor fixation (p=0.009) and more advanced cataract (p=0.013) were found associated with better image quality by Topcon. Images acquired by Topcon before and after FFA were identical (100%). The healthy disc was usually dark on HRA (72%), but showed mild autofluorescence on Topcon (85%). The healthy fovea showed in 100% Hypo-FAF on HRA, while Topcon showed in 53% Iso-FAF, in 43% mild Hypo-FAF, and in 4% Hypo-FAF as on HRA. No difference of FAF was found for geographic atrophy, pigment changes, and drusen, although Topcon images were often more detailed. Hyper-FAF due to serous exudation showed better on HRA. Cystic edema was visible only on HRA in a petaloid hyper-FAF pattern in 83%, while only two eyes (17%) showed similar behavior in both HRA- and Topcon images. Hard exudates caused Hypo-FAF only on HRA, hardly visible on Topcon. Blockage phenomenon by blood however was identical. Conclusions: The filter set of Topcon and the single image acquisition appear to be an advantage for patients with cataract and poor fixation respectively. Preceding FFA does not alter the Topcon FAF image. Regarding the FAF behavior, there are differences between the 2 systems which need to be taken into account when interpreting the images.

Impact of Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry on the Clinical Management of Patients With Gram-negative Bacteremia: A Prospective Observational Study.

Background. Early identification of pathogens from blood cultures using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry may optimize the choice of empirical antibiotic therapy in the setting of bloodstream infections. We aimed to assess the impact of this new technology on the use of antibiotic treatment in patients with gram-negative bacteremia. Methods. We conducted a prospective observational study from January to December 2010 to evaluate the sequential and separate impacts of Gram stain reporting and MALDI-TOF bacterial identification performed on blood culture pellets in patients with gram-negative bacteremia. The primary outcome was the impact of MALDI-TOF on empirical antibiotic choice. Results. Among 202 episodes of gram-negative bacteremia, Gram stain reporting had an impact in 42 cases (20.8%). MALDI-TOF identification led to a modification of empirical therapy in 71 of all 202 cases (35.1%), and in 16 of 27 cases (59.3%) of monomicrobial bacteremia caused by AmpC-producing Enterobacteriaceae. The most frequently observed impact was an early appropriate broadening of the antibiotic spectrum in 31 of 71 cases (43.7%). In total, 143 of 165 episodes (86.7%) of monomicrobial bacteremia were correctly identified at genus level by MALDI-TOF. Conclusions. In a low prevalence area for extended spectrum betalactamases (ESBL) and multiresistant gram-negative bacteria, MALDI-TOF performed on blood culture pellets had an impact on the clinical management of 35.1% of all gram-negative bacteremia cases, demonstrating a greater impact than Gram stain reporting. Thus, MALDI-TOF could become a vital second step beside Gram stain in guiding the empirical treatment of patients with bloodstream infection.

Maturation of the lymphoid system. III. Induction of selective unresponsiveness by injection of a haptenated carbohydrate into neonatal mice.

Neonatal treatment of A/J mice with DNP-Ficoll reduced or eliminated indirect anti-DNP PFC normally produced in response to adult challenge with DNP-keyhole limpet hemocyanin. The remaining direct anti-DNP PFC response was of low avidity. Spleen cells from neonatal A/J mice inhibited the in vitro but not the in vivo response of adult spleen cells to DNP-Ficoll.

Silver-assisted laser desorption ionization for high spatial resolution imaging mass spectrometry of olefins from thin tissue sections.

Silver has been demonstrated to be a powerful cationization agent in mass spectrometry (MS) for various olefinic species such as cholesterol and fatty acids. This work explores the utility of metallic silver sputtering on tissue sections for high resolution imaging mass spectrometry (IMS) of olefins by laser desorption ionization (LDI). For this purpose, sputtered silver coating thickness was optimized on an assorted selection of mouse and rat tissues including brain, kidney, liver, and testis. For mouse brain tissue section, the thickness was adjusted to 23 ± 2 nm of silver to prevent ion suppression effects associated with a higher cholesterol and lipid content. On all other tissues, a thickness of at 16 ± 2 nm provided the best desorption/ionization efficiency. Characterization of the species by MS/MS showed a wide variety of olefinic compounds allowing the IMS of different lipid classes including cholesterol, arachidonic acid, docosahexaenoic acid, and triacylglyceride 52:3. A range of spatial resolutions for IMS were investigated from 150 μm down to the high resolution cellular range at 5 μm. The applicability of direct on-tissue silver sputtering to LDI-IMS of cholesterol and other olefinic compounds presents a novel approach to improve the amount of information that can be obtained from tissue sections. This IMS strategy is thus of interest for providing new biological insights on the role of cholesterol and other olefins in physiological pathways or disease.

Cognition and brain function in schizotypy : a selective review

Schizotypy refers to a set of personality traits thought to reflect the subclinical expression of the signs and symptoms of schizophrenia. Here, we review the cognitive and brain functional profile associated with high questionnaire scores in schizotypy. We discuss empirical evidence from the domains of perception, attention, memory, imagery and representation, language, and motor control. Perceptual deficits occur early and across various modalities. Whilst the neural mechanisms underlying visual impairments may be linked to magnocellular dysfunction, further effects may be seen downstream in higher cognitive functions. Cognitive deficits are observed in inhibitory control, selective and sustained attention, incidental learning and memory. In concordance with the cognitive nature of many of the aberrations of schizotypy, higher levels of schizotypy are associated with enhanced vividness and better performance on tasks of mental rotation. Language deficits seem most pronounced in higher-level processes. Finally, higher levels of schizotypy are associated with reduced performance on oculomotor tasks, resembling the impairments seen in schizophrenia. Some of these deficits are accompanied by reduced brain activation, akin to the pattern of hypoactivations in schizophrenia spectrum individuals. We conclude that schizotypy is a construct with apparent phenomenological overlap with schizophrenia and stable inter-individual differences that covary with performance on a wide range of perceptual, cognitive and motor tasks known to be impaired in schizophrenia. The importance of these findings lies not only in providing a fine-grained neurocognitive characterisation of a personality constellation known to be associated with real-life impairments, but also in generating hypotheses concerning the aetiology of schizophrenia.

A new selective peroxisome proliferator-activated receptor gamma antagonist with antiobesity and antidiabetic activity.

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) plays a key role in adipocyte differentiation and insulin sensitivity. Its synthetic ligands, the thiazolidinediones (TZD), are used as insulin sensitizers in the treatment of type 2 diabetes. These compounds induce both adipocyte differentiation in cell culture models and promote weight gain in rodents and humans. Here, we report on the identification of a new synthetic PPARgamma antagonist, the phosphonophosphate SR-202, which inhibits both TZD-stimulated recruitment of the coactivator steroid receptor coactivator-1 and TZD-induced transcriptional activity of the receptor. In cell culture, SR-202 efficiently antagonizes hormone- and TZD-induced adipocyte differentiation. In vivo, decreasing PPARgamma activity, either by treatment with SR-202 or by invalidation of one allele of the PPARgamma gene, leads to a reduction of both high fat diet-induced adipocyte hypertrophy and insulin resistance. These effects are accompanied by a smaller size of the adipocytes and a reduction of TNFalpha and leptin secretion. Treatment with SR-202 also dramatically improves insulin sensitivity in the diabetic ob/ob mice. Thus, although we cannot exclude that its actions involve additional signaling mechanisms, SR-202 represents a new selective PPARgamma antagonist that is effective both in vitro and in vivo. Because it yields both antiobesity and antidiabetic effects, SR-202 may be a lead for new compounds to be used in the treatment of obesity and type 2 diabetes.

Analysis of Roman pottery graffiti by high resolution capture and 3D laser profilometry

The graffiti on pottery discovered on the site of Aventicum (Avenches, VD/Switzerland) form the largest corpus of minor inscriptions of the Roman Empire studied until now. Indeed, a total of 1828 graffiti have been found. The reading and the recording of the inscriptions are generally dependent on the state of conservation of the graffito and its support. In numerous cases, only a pale shadow of the inscription is visible, which makes traditional observations, such as visual observations with the naked eye, unsuitable for its decipherment. Consequently, advanced techniques have been applied for enhancing the readability of such inscriptions. In our paper we show the efficiency of 3D laser profilometry as well as high resolution photography as powerful means to decipher illegible engraved inscriptions. The use of such analyses to decipher graffiti on pottery or on other materials enables a better understanding of minor inscriptions and improves the knowledge of the daily life of ancient populations substantially.

Molecular basis of selective PPARgamma modulation for the treatment of Type 2 diabetes.

Peroxisome proliferator-activated receptors (PPARs) (alpha, beta/delta and gamma) are lipid sensors capable of adapting gene expression to integrate various lipid signals. As such, PPARs are also very important pharmaceutical targets, and specific synthetic ligands exist for the different isotypes and are either currently used or hold promises in the treatment of major metabolic disorders. In particular, compounds of the class of the thiazolinediones (TZDs) are PPARgamma agonists and potent insulin-sensitizers. The specific but still broad expression patterns of PPARgamma, as well as its implication in numerous pathways, constitutes also a disadvantage regarding drug administration, since this potentially increases the chance to generate side-effects through the activation of the receptor in tissues or cells not affected by the disease. Actually, numerous side effects associated with the administration of TZDs have been reported. Today, a new generation of PPARgamma modulators is being actively developed to activate the receptor more specifically, in a cell and time-dependent manner, in order to induce a specific subset of target genes only and modulate a restricted number of metabolic pathways. We will discuss here why and how the development of such selective PPARgamma modulators is possible, and summarize the results obtained with the published molecules.