Sex, menstrual cycle, and hormonal contraceptives influences on global-local processing

The effect of sex hormones on global-local tasks has rarely been studied, offering, when done, conflicting results possibly modulated by the congruency between hierarchical stimuli, and by the attentional demands. Here, we examined the global advantage (GA) effect in men (with high testosterone levels), women in the mid-luteal phase (with high levels of estradiol and progesterone), in the ovulatory phase (with high estradiol but low progesterone levels); and in the early follicular phase and with hormonal contraceptive (HC) use (with low sex hormone levels). The level of processing (global-local), the congruency (congruent vs. incongruent), and attentional demands (divided vs. selective) were manipulated. The divided-incongruent condition was sensible to estradiol and progesterone levels and, in this condition, mid-luteal women performed more locally while men performed more globally. The selective-incongruent condition was sensible to the testosterone level and, in this condition, men were faster. The HC group showed a congruency effect in the GA reaction times (RTs) during both, divided and selective conditions. Finally, the GA RTs of the ovulatory group differed from the early follicular and mid-luteal groups only in the congruent-selective condition, but the performance was not related with sex hormone levels. This result is interpreted in relation with the brain effects of estradiol in the absence but not in the presence of progesterone. Thus, sex, menstrual cycle, HC, task difficulty and sex hormones seem to modulate performance in the global-local task. These factors represent an important source of variability in studies focused on the processing of hierarchical stimuli and allow apparently inconsistent data to be explained.

Imaging-guided nanomedicine development

Nanomedicine research is an active field that produces thousands of studies every year. However, translation of nanotherapeutics to the clinic has yet to catch up with such a vast output. In recent years, the need to better understand nanomedicines' in vivo behavior has been identified as one of the major challenges for efficient clinical translation. In this context, noninvasive imaging offers attractive solutions to provide valuable information about nanomedicine biodistribution, pharmacokinetics, stability, or therapeutic efficacy. Here, we review the latest imaging approaches used in the development of therapeutic nanomedicines, discuss why these strategies bring added value along the translational pipeline, and give a perspective on future advances in the field.

Application of low-intensity pulsed therapeutic ultrasound on mesenchymal precursors does not affect their cell properties

Ultrasound is considered a safe and non-invasive tool in regenerative medicine and has been used in the clinic for more than twenty years for applications in bone healing after the approval of the Exogen device, also known as low-intensity pulsed ultrasound (LIPUS). Beyond its effects on bone health, LIPUS has also been investigated for wound healing of soft tissues, with positive results for various cell processes including cell proliferation, migration and angiogenesis. As LIPUS has the potential to treat chronic skin wounds, we sought to evaluate the effects produced by a conventional therapeutic ultrasound device at low intensities (also considered LIPUS) on the migration capacity of mouse and human skin mesenchymal precursors (s-MPs). Cells were stimulated for 3 days (20 minutes per day) using a traditional ultrasound device with the following parameters: 100 mW/cm2 with 20% duty cycle and frequency of 3 MHz. At the parameters used, ultrasound failed to affect s-MP proliferation, with no evident changes in morphology or cell groupings, and no changes at the cytoskeletal level. Further, the migration and invasion ability of s-MPs were unaffected by the ultrasound protocol, and no major changes were detected in the gene/protein expression of ROCK1, integrin β1, laminin β1, type I collagen and transforming growth factor β1. Finally, RNA-seq analysis revealed that only 10 genes were differentially expressed after ultrasound stimulation. Among them, 5 encode for small nuclear RNAs and 2 encode for proteins belonging to the nuclear pore complex. Considering the results overall, while the viability of s-MPs was not affected by ultrasound stimulation and no changes were detected in proliferation/migration, RNA-seq analysis would suggest that s-MPs do respond to ultrasound. The use of 100 mW/cm2 intensity or conventional therapeutic ultrasound devices might not be optimal for the stimulation the properties of cell populations. Future studies should investigate the potential application of ultrasound using variations of the tested parameters.

METHODOLOGY FOR HIGH-FIDELITY DETERMINISTIC MODELLING OF SWISS LWR FUEL ASSEMBLIES

The main goal of this work is to perform pin-by-pin calculations of Swiss LWR fuel assemblies with neutron transport deterministic methods. At Paul Scherrer Institut (PSI), LWR calculations are performed with the core management system CMSYS, which is based on the Studsvik suite of codes. CMSYS includes models for all the Swiss reactors validated against a database of experimental information. Moreover, PSI has improved the pin power calculations by developing models of Swiss fuel assemblies for the Monte Carlo code MCNP, with the isotopic compositions obtained from the In-Core Fuel Management data of the Studsvik suite of codes, by using the SNF code. A step forward is to use a neutron code based on fast deterministic neutron transport methods. The method used in this work is based on a planar Method of Characteristics in which the axial coupling is solved by 1D SP3 method. The neutron code used is nTRACER. Thus, the methodology of this work develops nTRACER models of Swiss PWR fuel assemblies, in which the fuel of each pin and axial level is modelled with the isotopic composition obtained from SNF. This methodology was applied to 2D and 3D calculations of a Swiss PWR fuel assembly. However, this method has two main limitations. First, the cross sections libraries of nTRACER lack some of the isotopes obtained by SNF. Fortunately, this work proves that the missing isotopes do not have a strong effect on keff and the power distribution. Second, the 3D models require high computational memory resources, that is, more than 260 Gb. Thus, the nTRACER code was modified, so now it uses only 8 Gb, without any loss of accuracy. Finally, the keff and power results are compared with Monte Carlo calculations obtained by Serpent.

Influence of sex, menstrual cycle, and hormonal contraceptives on egocentric navigation with or without landmarks

This study examines the influence of sex, menstrual cycle, hormonal contraceptives (HC) and sex hormone levels in following egocentric navigation instructions with or without landmarks. Estradiol seem to bias the reference frame for navigation during estrous cycle of female rats. However, previous studies in humans found no differences in overall navigation between women in their early follicular and mid-luteal menstrual cycle phases, whose performance was worse than that of men. Our study hypothesis was that the performance of women would be improved during the peri-ovulatory phase and would remain the same during placebo and active phases of HC users. The study included 21 men, 62 women with natural menstrual cycle (21 during early follicular phase, 20 during peri-ovulatory phase, and 21 during mid-luteal phase), and 38 women that were receiving HC (13 during placebo phase and 25 during active phase). The men outperformed the women with a natural menstrual cycle when following egocentric instructions without landmarks. However, the women's performance varied according to the phase of their menstrual cycle, differing from men during early follicular and mid-luteal phases but not during the peri-ovulatory phase. The use of HC also improved the performance of women to the extent that the difference with men disappeared. No differences were observed between HC-placebo and HC-active user groups during egocentric navigation without landmarks and among all groups during egocentric navigation with landmarks. Analysis of salivary hormones showed that testosterone levels were higher in men and that estradiol levels in women were higher during peri-ovulatory and mid-luteal phases and also in HC users. Progesterone levels were higher in women during the mid-luteal phase. These results appear compatible with beneficial effect of testosterone and estradiol on egocentric navigation without landmarks and with a block of this effect produced by progesterone.

Ultrasound Therapy: Experiences and Perspectives for Regenerative Medicine

Ultrasound has emerged as a novel tool for clinical applications, particularly in the context of regenerative medicine. Due to its unique physico-mechanical properties, low-intensity ultrasound (LIUS) has been approved for accelerated fracture healing and for the treatment of established non-union, but its utility has extended beyond tissue engineering to other fields, including cell regeneration. Cells and tissues respond to acoustic ultrasound by switching on genetic repair circuits, triggering a cascade of molecular signals that promote cell proliferation, adhesion, migration, differentiation, and extracellular matrix production. LIUS also induces angiogenesis and tissue regeneration and has anti-inflammatory and anti-degenerative effects. Accordingly, the potential application of ultrasound for tissue repair/regeneration has been tested in several studies as a stand-alone treatment and, more recently, as an adjunct to cell-based therapies. For example, ultrasound has been proposed to improve stem cell homing to target tissues due to its ability to create a transitional and local gradient of cytokines and chemokines. In this review, we provide an overview of the many applications of ultrasound in clinical medicine, with a focus on its value as an adjunct to cell-based interventions. Finally, we discuss the various preclinical and clinical studies that have investigated the potential of ultrasound for regenerative medicine.

P1489 Late cardiovascular manifestations of Gregg syndrome: Importance of multimodal imaging approach to optimize diagnosis

Conclusion

Although infrequent because of successful worldwide vaccination policies, sporadic cases of Gregg syndrome can still be seen, especially in neglected populations with poor access to health services or in unvaccinated patients. Long-term follow-up of all patients undergoing repair procedures is warranted for evaluation of late occurring complications. This case underscores the importance of multimodality imaging for a complete anatomical and functional diagnosis of complex cardiovascular conditions.

Abstract P1489 Figure 1

Phytophthora betacei, a new species within Phytophthora clade 1c causing late blight on Solanum betaceum in Colombia

Over the past few years, symptoms akin to late blight disease have been reported on a variety of crop plants in South America. Despite the economic importance of these crops, the causal agents of the diseases belonging to the genus Phytophthora have not been completely characterized. In this study, a new Phytophthora species was described in Colombia from tree tomato (Solanum betaceum), a semi-domesticated fruit grown in northern South America. Comprehensive phylogenetic, morphological, population genetic analyses, and infection assays to characterize this new species, were conducted. All data support the description of the new species, Phytophthora betacei sp. nov. Phylogenetic analyses suggest that this new species belongs to clade 1c of the genus Phytophthora and is a close relative of the potato late blight pathogen, P. infestans. Furthermore, it appeared as the sister group of the P. andina strains collected from wild Solanaceae (clonal lineage EC-2). Analyses of morphological and physiological characters as well as host specificity showed high support for the differentiation of these species. Based on these results, a complete description of the new species is provided and the species boundaries within Phytophthora clade 1c in northern South America are discussed.

Nestin-expressing progenitor cells: function, identity and therapeutic implications

The neuroepithelial stem cell protein, or Nestin, is a cytoskeletal intermediate filament initially characterized in neural stem cells. However, current extensive evidence obtained in in vivo models and humans shows presence of Nestin+ cells with progenitor and/or regulatory functions in a number of additional tissues, remarkably bone marrow. This review presents the current knowledge on the role of Nestin in essential stem cell functions, including self-renewal/proliferation, differentiation and migration, in the context of the cytoskeleton. We further discuss the available in vivo models for the study of Nestin+ cells and their progeny, their function and elusive nature in nervous system and bone marrow, and their potential mechanistic role and promising therapeutic value in preclinical models of disease. Future improved in vivo models and detection methods will allow to determine the true essence of Nestin+ cells and confirm their potential application as therapeutic target in a range of diseases.

Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth

The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude Water Cherenkov Observatory (HAWC), of extended tera-electron volt gamma-ray emission coincident with the locations of two nearby middle-aged pulsars (Geminga and PSR B0656+14). The HAWC observations demonstrate that these pulsars are indeed local sources of accelerated leptons, but the measured tera-electron volt emission profile constrains the diffusion of particles away from these sources to be much slower than previously assumed. We demonstrate that the leptons emitted by these objects are therefore unlikely to be the origin of the excess positrons, which may have a more exotic origin.

Membrane Blebbing Is Required for Mesenchymal Precursor Migration

Mesenchymal precursors (MPs) present some advantageous features, such as differentiation and migration, which make them promising candidates for cell therapy. A better understanding of MP migration characteristics would aid the development of cell delivery protocols. Traditionally, cell migration is thought to occur only through the formation of lamellipodia. More recently, contractility-driven bleb formation has emerged as an alternative mechanism of motility. Here we report that MPs derived from different tissues present spontaneously dynamic cytoplasmic projections in sub-confluent culture, which appear as a combination of lamellipodia with blebs in the leading edge. Upon initial seeding, however, only bleb structures could be observed. Immunofluorescence revealed the presence of pERM, RhoA and F-actin during the blebbing process. Results from migration assays in the presence of blebbistatin, a myosin II inhibitor, showed that bleb formation correlated with migratory capacity, suggesting a functional role for blebs in migration. Bleb formation might be a useful mechanism to improve cell migration in cellular therapy protocols.

Obesity-driven alterations in adipose-derived stem cells are partially restored by weight loss

OBJECTIVE

The therapeutic potential of adipose-derived stem cells (ASCs) is reduced by various stress-inducing conditions that affect tissue homeostasis such as diabetes, aging, and obesity. Previous works have provided evidence of negative effects of obesity on ASC populations, but it is unclear whether this persists after a weight loss. This study evaluated whether weight loss can restore the attenuated properties found in ASCs derived from populations with obesity (oASCs).

METHODS

In vitro functional analyses were performed to investigate the possible recovery properties in mouse oASCs. Using ASCs isolated from subcutaneous tissue from formerly obese mice (dASCs) and control mice (cASCs), cell proliferation, viability, and some regenerative properties in these cells were analyzed compared with oASCs to evaluate the functional cell state.

RESULTS

Cell proliferation, viability, and some regenerative properties are strengthened in dASCs and cASCs compared with oASCs. Nevertheless, metabolic analysis reveals a mitochondrial load misbalance and function leading to impaired respiration in dASCs.

CONCLUSIONS

This study demonstrates that an initial obese environment triggers a detrimental state in ASCs that is not completely recovered after weight loss.

Altered metabolic and stemness capacity of adipose tissue-derived stem cells from obese mouse and human

Adipose stem cells (ASCs) are an appealing source of cells for therapeutic intervention; however, the environment from which ASCs are isolated may impact their usefulness. Using a range of functional assays, we have evaluated whether ASCs isolated from an obese environment are comparable to cells from non-obese adipose tissue. Results showed that ASCs isolated from obese tissue have a reduced proliferative ability and a loss of viability together with changes in telomerase activity and DNA telomere length, suggesting a decreased self-renewal capacity. Metabolic analysis demonstrated that mitochondrial content and function was impaired in obese-derived ASCs resulting in changes in favored oxidative substrates. These findings highlight the impact of obesity on adult stem properties. Hence, caution should be exercised when considering the source of ASCs for cellular therapies since their therapeutic potential may be impaired.

Simple measurement of the apparent viscosity of a cell from only one picture: Application to cardiac stem cells

Mechanical deformability of cells is a key property that influences their ability to migrate and their contribution to tissue development and regeneration. We analyze here the possibility of characterizing the overall deformability of cells by their apparent viscosity, using a simplified method to estimate that parameter. The proposed method simplifies the quantitative analysis of micropipette-aspiration experiments. We have studied by this procedure the overall apparent viscosity of cardiac stem cells, which are considered a promising tool to regenerate damaged cardiac tissue. Comparison with the apparent viscosity of low-viscosity cells such as immune-system cells suggests that treatments to reduce the viscosity of these cells could enhance their ability to repair damaged cardiac tissue.

The potential of stem cells in the treatment of cardiovascular diseases

Although the adult mammalian heart was once believed to be a post-mitotic organ without any capacity for regeneration, recent findings have challenged this dogma. A modified view assigns to the mammalian heart a measurable capacity for regeneration throughout life. The ultimate goals of the cardiac regeneration field have been pursued by multiple strategies, including understanding the developmental biology of cardiomyocytes and cardiac stem and progenitor cells, applying chemical genetics, and engineering biomaterials and delivery methods that facilitate cell transplantation. Successful stimulation of endogenous regenerative capacity in injured adult mammalian hearts can benefit from studies of natural cardiac regeneration.

Properties of capsaicinoids for the control of fungi and oomycetes pathogenic to pepper

Capsaicinoids are pungent compounds found in pepper (Capsicum spp.) fruits. Capsaicin showed antimicrobial activity in plate assays against seven isolates of five species of fungi and nine isolates of two species of oomycetes. The general trend was that oomycetes were more inhibited than fungi. Assays of capsaicin biosynthetic precursors suggest that the lateral chain of capsaicinoids has more inhibitory activity than the phenolic part. In planta tests of capsaicinoids (capsaicin and N-vanillylnonanamide) applied to the roots demonstrated that these compounds conferred protection against the pathogenic fungus Verticillium dahliae and induced both chitinase activity and expression of several defence-related genes, such as CASC1, CACHI2 and CABGLU. N-Vanillylnonanamide infiltrated into cotyledons confers systemic protection to the upper leaves of pepper against the fungal pathogen Botrytis cinerea. In wild-type tomato plants such cotyledon infiltration has no protective effect, but is effective in the Never-ripe tomato mutant impaired in ethylene response. A similar effect was observed in tomato after salicylic acid infiltration.

Obese-derived ASCs show impaired migration and angiogenesis properties

Efficient delivery of stem cells to target tissues is a major problem in regenerative medicine. Adipose derived stem cells have been proposed as important tools in cell therapy for recovering tissues after damage. Nevertheless, the ability of these ASCs to migrate or invade in order to reach the tissue of interest has not been tested so far. In this study we present evidence that the ASCs derived from obese subjects present a detrimental ability to migrate and invade in comparison with ASCs derived from control subjects. Besides, obese-derived ASCs are unable to respond to certain stimuli and to form enough capillaries after stimulation. We propose that the use of specific cytokines could overcome these deficiencies of the obese environment, offering a tool to optimize cell therapy.

Metabolic rescue of obese adipose-derived stem cells by Lin28/Let7 pathway

Adipose-derived stem cells (ASCs) are promising candidates for autologous cell-based regeneration therapies by virtue of their multilineage differentiation potential and immunogenicity; however, relatively little is known about their role in adipose tissue physiology and dysfunction. Here we evaluated whether ASCs isolated from nonobese and obese tissue differed in their metabolic characteristics and differentiation potential. During differentiation to mature adipocytes, mouse and human ASCs derived from nonobese tissues both increased their insulin sensitivity and inhibition of lipolysis, whereas obese-derived ASCs were insulin-resistant, showing impaired insulin-stimulated glucose uptake and resistance to the antilipolytic effect of insulin. Furthermore, obese-derived ASCs showed enhanced release of proinflammatory cytokines and impaired production of adiponectin. Interestingly, the delivery of cytosol from control ASCs into obese-derived ASCs using a lipid-based, protein-capture methodology restored insulin sensitivity on glucose and lipid metabolism and reversed the proinflammatory cytokine profile, in part due to the restoration of Lin28 protein levels. In conclusion, glucose and lipid metabolism as well as maturation of ASCs is truncated in an obese environment. The reversal of the altered pathways in obese cells by delivery of normal subcellular fractions offers a potential new tool for cell therapy.

Method for obtaining committed adult mesenchymal precursors from skin and lung tissue

Aims

The present study reports an easy and efficient method for obtaining adult mesenchymal precursors from different adult mouse tissues.

Materials and Methods

We describe the isolation and expansion of mesenchymal precursors from skin and lung by a non-enzymatic method. Skin and lung mesenchymal precursors isolated by a modified explant technique were characterized in vitro by defined morphology and by a specific gene expression profile and surface markers.

Results and Conclusions

Our results show that these precursors express stem cell and mesenchymal surface markers as well as epithelial markers. However, they are negative for markers of endothelium, cardiac and skeletal muscle or adipose tissue, indicating that they have initiated commitment to the tissues from which were isolated. These precursors can migrate without any stimulus and in response to stimuli as SDF1, MCP1 and TNFα and can be differentiated into epithelial lineages. Based on the properties of these precursors from adult tissues, we propose their use as tools for regenerative biomedicine.

Wolbachia induced cytogenetical effects as evidenced in Chorthippus parallelus (Orthoptera)

The cytoplasmic incompatibility induced by the bacterial endosymbiont Wolbachia is attributed to chromatin modification in the sperm of infected individuals and is only 'rescued' by infected females after fertilization. Chorthippus parallelus is a grasshopper with 2 subspecies that form a hybrid zone in the Pyrenees in which this Wolbachia-generated cytoplasmic incompatibility has recently been described. The analysis of certain cytogenetic traits (sex chromosome-linked heterochromatic bands, nucleolar organizing region expression, spermatid size and morphology, and number of chiasmata formed) in pure and hybrid Chorthippus parallelus that are infected and not infected by this bacterium indicates that the infection affects some of these traits and, in the case of the spermatids, reveals a synergism between the infection and the hybrid condition. These results are interpreted as being secondary effects of the chromatin modification induced by Wolbachia which thereby support this model of modification/rescue. The possible effects of these cytogenetic variations on affected individuals are also considered.

Amatoxin and phallotoxin composition in species of the genus Amanita in Colombia: a taxonomic perspective

Some species in the genus Amanita have a great variety of toxic secondary metabolites. They are characterized macroscopically by having a white spore print and free gills, and microscopically by the presence of a divergent hymenophoral trama. Some species of Amanita present in Colombia were chemically characterized by analyzing their toxin composition using HPLC. Samples were collected in oak (Quercus humboldtii) and pine (Pinus radiata) forests. Twelve species were recovered, Amanita fuligineodisca, Amanita xylinivolva, Amanita flavoconia, Amanita rubescens, Amanita bisporigera, Amanita muscaria, Amanita humboldtii, Amanita sororcula, Amanita brunneolocularis, Amanita colombiana, Amanita citrina, Amanita porphyria as well as two unreported species. Results showed that most of the analyzed species have α -amanitin in concentrations ranging from 50 ppm to 6000 ppm. Concentrations of α-amanitin in the pileus were significantly greater than in the stipe. Phalloidin and phallacidin were only present in A. bisporigera. Chromatographic profiles are proposed as an additional taxonomic tool since specific peaks with similar retention times were conserved at the species level.

First Report of Phytophthora infestans Causing Late Blight on Solanum viarum in Colombia

Solanum viarum Dunal (tropical soda apple) belongs to the section Acanthophora in the genus Solanum, which includes nearly 20 neotropical species of herbs and small shrubs (2). The species in this section are sometimes called the 'spiny Solanums' (2) and are adapted mainly to highly disturbed habitats and open secondary forests. The center of diversity is eastern Brazil (3). Since the early 1990s, S. viarum has been a problematic weed in Florida where it was listed as a noxious weed in 1993, followed in 1994 by its addition to the Federal Noxious Weed List of the USDA. On 17 April 2010, 12 plants of S. viarum located close to a S. betaceum crop (tree tomato) in the province of Caldas (Department of Antioquia, central northwestern Colombia) were found with symptoms similar to late blight caused by Phytophthora infestans on S. tuberosum (potato). Fifteen leaves from 12 plants with blackish, water-soaked lesions showing a white sporulation on the abaxial side were collected and processed within 3 days. The leaves were placed in a humid chamber and incubated in darkness at room temperature (18°C mean temperature) until sporulation was observed. Microscopic characteristics were consistent with Phytophthora spp. Only one axenic culture was obtained by successive subcultures in rye B agar plates. After an incubation period of 8 days, plates were washed with distilled water and ovoid, semipapillate caduceus sporangia ranging from 38 to 41 μm long (average 39; N = 86) and 23 to 29 μm wide (average 26; N = 86) were observed. To fulfill Koch's postulates and test the isolate for the ability to infect potato as well as Solanum spp. associated with potato crops in Colombia, triplicate pathogenicity tests were carried out on three detached leaves of S. viarum, S. tuberosum, and S. americanum (American nightshade). A 1 × 10⁴ sporangia/ml suspension of the Phytophthora isolate, estimated using a haemocytometer, was obtained from 8-day-old cultures grown on rye B agar. The suspension was incubated at 4°C for 2 h to induce zoospore release. The leaves were then inoculated by spraying them until runoff. After an incubation period of 5 days at 18°C in a humidity chamber, mycelia, sporangia, and brownish lesions, similar to those described above, were observed in the leaves of all three hosts, indicating pathogenicity. DNA extraction was performed from the P. infestans isolate (4). Four nuclear loci, ITS, β-tubulin, Ras, and Avr3a, as well as one mitochondrial gene, cytochrome c oxidase 1 (Cox1), were amplified and sequenced. Sequences were compared with GenBank databases using Blastn. In all cases, the best hits corresponded to P. infestans (GenBank Accession No. HQ639930 for Avr3A, HQ639931 for β-tubulin, HQ639932 for Cox1, HQ639933 for iRas, HQ639934 for Ras, and JF419363 for ITS). Reports of P. infestans causing typical late blight symptoms on wild solanaceous plants are becoming more frequent and have been made from other countries such as Peru (1). To our knowledge, this is the first time that P. infestans has been observed and isolated from S. viarum in Colombia, introducing the possibility of this wild solanaceous weed as another late blight host. References: (1) G. Garry et al. Eur. J. Plant Pathol. 113:71, 2005. (2) R. Levin et al. Am. J. Bot. 92:603, 2005. (3) M. Nee. A Revision of Solanum Section Acanthophora. Ph.D. diss. University of Wisconsin, Madison, 1979. (4) A. M. Vargas et al. Phytopathology 99:82, 2009.

Oxytocin polyuria and polydipsia is blocked by NaCl administration in food-deprived male rats

We examined the effects of NaCl injections on the polydipsia and polyuria induced by subcutaneous oxytocin (OT) administration in food-deprived male rats. During the first 12 h of the treatment day, both food deprivation and OT administration increased urine excretion but reduced water intake, water balance (fluid intake minus urine volume) and body weight. OT treatment enhanced urine excretion and the reduction in water balance and body weight without reducing the water intake of food-deprived animals. Analysis of the physiological effects of OT administration showed increases in urinary sodium concentration, sodium excretion and a reduced plasma sodium concentration. During the second 12 h, OT increased both urine excretion and water intake in food-deprived but not in ad lib.-fed rats. However, hypertonic NaCl administration at the start of this second 12-h period blocked the polyuric and polydipsic responses observed in the OT/deprived group but increased the water intake of the ad lib. groups. After the whole 24-h period, animals treated with OT showed a water balance and body weight change matching those observed in Control animals. Although the recording time period is a critical factor to demonstrate the effect of peripheral OT administration on water intake, the results obtained suggest that the polyuric and polydipsic responses observed in food-deprived animals depend on the negative sodium and water balance induced by the natriuretic effect of OT and the unavailability of sodium. These OT-induced deficits can be counteracted by the administration of hypertonic NaCl solutions or simply by the intake of standard food.

Clostridium lavalense sp. nov., a glycopeptide-resistant species isolated from human faeces

Two vancomycin-resistant, strictly anaerobic, Gram-positive, rod-shaped, spore-forming organisms (strains CCRI-9842(T) and CCRI-9929) isolated from human faecal specimens in Québec, Canada, and Australia were characterized using phenotypic, biochemical and molecular taxonomic methods. Pairwise analysis of the 16S rRNA gene sequences showed that both strains were closely related to each other genetically (displaying 99.2 % sequence similarity) and represented a previously unknown subline within the Clostridium coccoides rRNA group of organisms (rRNA cluster XIVa of the genus Clostridium). Strains CCRI-9842(T) and CCRI-9929 used carbohydrates as fermentable substrates, producing acetic acid as the major product of glucose metabolism. The novel strains were most closely related to Clostridium asparagiforme, Clostridium bolteae and Clostridium clostridioforme, but morphological, biochemical and phylogenetic studies demonstrated that they represent a previously unidentified species of the genus Clostridium. This was confirmed by the unique cellular fatty acid composition of strains CCRI-9842(T) and CCRI-9929. Therefore, on the basis of data from the polyphasic taxonomic analysis, it is proposed that strains CCRI-9842(T) and CCRI-9929 represent a novel species of the genus Clostridium, for which the name Clostridium lavalense sp. nov. is proposed. The type strain is CCRI-9842(T) (=CCUG 54291(T)=JCM 14986(T)=NML 03-A-015(T)).

Oxytocin, water intake, and food sodium availability in male rats

This study examined the effect of subcutaneous administration of the neurohormone oxytocin on water intake of ad lib-fed (with or without sodium availability in the diet) and food-deprived animals. Results of the first experiment showed that oxytocin increased water intake and urine excretion in food-deprived but not in ad lib-fed animals. However, oxytocin treatment did not modify the reduced water "balance" (fluid intake minus urine volume) resulting from food deprivation or the daily food intake (Experiment 1). The dose-dependent polydipsic effect of oxytocin on food-deprived rats was always preceded by an increase in sodium and fluid urine excretion (Experiment 2). Oxytocin also increased the water intake of animals fed ad lib with a low sodium diet (Experiment 3). These results suggest that the effect of oxytocin on water intake is dependent on the presence or absence of sodium in the diet and that the excretion of sodium is the main mechanism of oxytocinergic polydipsia in food-deprived male rats.

Dipsogenic potentiation by sodium chloride but not by sucrose or polyethylene glycol in tuberomammillary-mediated polydipsia

The aim of this study was to examine the dipsogenic mechanisms involved in the recently discovered tuberomammillary (TM)-mediated polydipsia. Rats with bilateral electrolytic lesions of each TM subnucleus underwent several dipsogenic treatments, both osmotic and volemic. Animals with ventral (E2) or medial TM lesions (E3 or E4) showed a potentiated hyperdipsic response to hypertonic sodium chloride administration but not to sucrose or polyethylene glycol treatments. The increase in response to sodium chloride was significantly greater in groups E3/E4 and E2 than in the non-lesioned group and in animals with polydipsia induced by lesion of the median eminence. As previously reported, hyperphagia was induced by lesion to ventral TM nuclei (E1 or E2), confirming a possible role for the TM complex in food intake. However, lesions in medial nuclei (E3 or E4) did not produce this increase in food intake. These results are interpreted in relation to the hypothalamic systems involved in food and water intake.

Hyperphagia and increased body weight induced by lesions of the ventral tuberomammillary system

Individual lesions of the caudal (E1) or rostral (E2) ventral tuberomammillary nuclei induced hyperphagia in Wistar rats. The aim of the present study was to examine the additive or united effects of combined lesions of E1+E2 in food intake. E1+E2 lesions produced an immediate, potent and permanent hyperphagic response that was greater than that observed in groups with individual lesions (E1 or E2) during the 22-day observation period. Furthermore, at the end of this period (Days 17/22), the combined lesions induced a greater increase in body weight compared with groups with individual lesions. As previously reported, polydipsia is also induced by lesions of the ventral tuberomammillary subnuclei. However, in this case, responses of the individual polydipsic groups did not differ from those found in the E1+E2 ventral tuberomammillary group. These results are interpreted in terms of the hypothalamic systems involved in food and water intake.

Managing an odour episode in Barcelona's water supply: strategies adopted, the causative agent (diacetyl) and determination of its organoleptic properties

The Llobregat River is a basic drinking water resource for the city of Barcelona, meeting 40% of the demand. The river runs through a densely populated industrial area, so that it has in its history experienced various episodes due to industrial spills. The present work deals with a recent episode involving diacetyl. To the best of our knowledge this episode is the first time that this compound has been identified as an odour-causing compound in water. In a previous work the analytical method used for the identification of the compound causing the episode was described. The present work focuses its attention on how the episode was handled: action taken at the Sant Joan Despi water treatment plant and the sampling strategy on the river that led to the identification of the company responsible for the spill, a paper mill. It also deals with the role played by the FPA panel in the resolution of the episode: organoleptic description of samples of the problem in the initial phase of the episode (from the treatment plant, distribution network and customer complaints) and, once the compound responsible was identified, the determination of its organoleptic characteristics (odour threshold, odour descriptors, Weber-Fechner curve).

Biopesticide effect of green compost against fusarium wilt on melon plants

AIMS

The biopesticide effect of four green composts against fusarium wilt in melon plants and the effect of soil quality in soils amended with composts were assayed.

METHODS AND RESULTS

The composts consisted of pruning wastes, with or without addition of coffee wastes (3/1 and 4/1, dry wt/dry wt) or urea (1000/1, dry wt/dry wt). In vitro experiments suggested the biopesticide effect of the composts against Fusarium oxysporum, while only the compost of pine bark and urea (1000/1dry wt/dry wt) had an abiotic effect. Melon plant growth with composts and F. oxysporum was one to four times greater than in the non-amended soil, although there was no significant decrease in the level of the F. oxysporum in the soil. The addition of composts to the soil also improved its biological quality, as assessed by microbiological and biochemical parameters: ATP and hydrolases involved in the P (phosphatase), C (beta-glucosidase) and N (urease) cycles.

CONCLUSIONS

Green composts had greater beneficial characteristics, improved plant growth and controlled fusarium wilt in melon plants. These composts improve the soil quality of semi-arid agricultural soils.

SIGNIFICANCE AND IMPACT OF THE STUDY

Biotic and abiotic factors from composts have been tested as responsible of their biopesticide activity against fusarium wilt.

Characterization of a Tn5382-like transposon containing the vanB2 gene cluster in a Clostridium strain isolated from human faeces

OBJECTIVES

During a hospital surveillance programme to detect VRE carriers, an anaerobic vancomycin-resistant bacterial strain CCRI-9842 containing a vanB gene was isolated from a human faecal specimen. In this study, we have characterized this strain and its vanB-containing element.

METHODS

Strain CCRI-9842 was characterized by 16S rDNA sequencing and susceptibility testing. PCR mapping and sequencing of the vanB-containing element, as well as plasmid extraction and mating experiments, were carried out to investigate the genetic basis of vancomycin resistance in this strain.

RESULTS

Strain CCRI-9842 was identified as a Clostridium species closely related to Clostridium bolteae (96.8% 16S rDNA identity). This strain was resistant to a high level of vancomycin (MIC of 256 mg/L), but was susceptible to teicoplanin and ampicillin. The complete sequence of the CCRI-9842 vanB gene exhibited 99.1% identity with that of vanB2. PCR mapping and sequencing showed that the genetic element carrying vanB2 was similar to transposon Tn5382/Tn1549. This Tn5382-like transposon forms circular intermediates and is flanked on the left and right ends by repeat sequences of at least 700 bp in the opposite direction. No plasmid was detected in this strain, suggesting that the Tn5382-like transposon was integrated into the chromosome. The vancomycin resistance was not transferable to enterococci.

CONCLUSIONS

Our report shows for the first time the presence of a Tn5382-like transposon carrying vanB2 in a Clostridium species of the human intestinal flora. This suggests that the vanB2 Tn5382-like transposon is an important vector for the spread of vancomycin resistance in several bacterial species.

Preimplantation testing for chromosomal disorders improves reproductive outcome of poor-prognosis patients

The clinical impact of PGD was evaluated through the analysis of the reproductive outcome before and after PGD in the same group of poor prognosis IVF patients, undergoing PGD for chromosomal abnormalities. Based on a series of 2359 PGD cycles, resulting in the establishment of 498 chromosomal abnormality-free clinical pregnancies, the reproductive history prior to PGD was analysed. Of 483 previous pregnancies analysed in patients with 432 pregnancies generated after PGD for aneuploidies, 328 (68%) ended in spontaneous abortions, in contrast to 28.4% after PGD, with only 155 (32%) resulting in deliveries, compared with 71.9% take-home baby rates after PGD. The patients experienced 315 previous IVF attempts, resulting in the transfer of 706 embryos in 308 cycles, of which only 49 (6.9%) implanted, compared with a 34.9% implantation rate observed in the same patients after PGD. Similar analysis of the previous reproductive outcomes of 45 carriers of balanced translocations achieving pregnancies following PGD, showed even stronger clinical impact, with a reduction of spontaneous abortions from 87.8% to 17.8%, and improvement of take-home baby rate from 11.5% to 81.4% after PGD. The results demonstrate a strong clinical impact of PGD, resulting in improvement of implantation rate, reduction of spontaneous abortions and increase in the take-home baby rate.

[Comparison of three genotyping methods for the detection of HIV-1 resistance to antiretroviral drugs]

Highly active antiretroviral therapy has dramatically improved the life expectancy of human immunodeficiency virus (HIV)-infected patients, but mutations in the HIV-1 reverse transcriptase (RT) and protease (P) genes confer drug failure. Evaluation of drug resistance genotyping in HIV-1 has proven to be useful for the selection of drug combinations with maximum antiretroviral activity. The aim of this study was to evaluate the optimal procedure to determine the resistance profile in the laboratory. Plasma from 90 antiretroviral-treated patients was analyzed by reverse hybridization, which identifies the presence of wild-types or mutations at the 19 key codons for protease and RT regions, and was compared with two other methods of direct cDNA sequencing. A total of 408 mutations were detected by InnoLiPA HIV-1, (Line Probe Assay, Innogenetics, Belgium), 572 by TrueGene HIV-1 Genotyping System (Visible Genetics, Canada), and 721 by ViroSeq HIV-1 Genotyping System (Perkin Elmer/Applied Biosystems, California). Hybridization detected a significantly higher number of primary mutations which are associated with a high level of drug resistance (p <0.001). Hybridization also detected a higher number of mixtures of wild-type and mutant viruses. There was a good concordance among the three methods, although it was higher between the two sequencing methods. Sequencing determines a higher number of mutations, but hybridization better identifies primary mutations correlated with a high level of drug resistance. Hybridization is more suitable for detecting mixed populations and is easier to implement in clinical laboratories but does not eliminate the need for sequence analysis for detection of drug-resistant HIV.

Survival of leukemic B cells promoted by engagement of the antigen receptor

Chronic lymphocytic leukemia (CLL) is an incurable leukemia characterized by the slow but progressive accumulation of cells in a CD5+ B-cell clone. Like the nonmalignant counterparts, B-1 cells, CLL cells often express surface immunoglobulin with the capacity to bind autologous structures. Previously there has been no established link between antigen-receptor binding and inhibition of apoptosis in CLL. In this work, using primary CLL cells from untreated patients with this disease, it is demonstrated that engagement of surface IgM elicits a powerful survival program. The response includes inhibition of caspase activity, activation of NF-kappaB, and expression of mcl-1, bcl-2, and bfl-1 in the tumor cells. Blocking phosphatidylinositol 3-kinase (PI3-K), a critical mediator of signals through the antigen receptor, completely abrogated mcl-1 induction and impaired survival in the stimulated cells. These data support the contention that CLL cell survival is promoted by antigen for which the malignant clone has affinity, and suggest that pharmacologic interference with antigen-receptor-derived signals has potential for therapy in patients with CLL.

The rendezvous technique for the treatment of choledocholithiasis

BACKGROUND

The rendezvous technique combines endoscopy with percutaneous transhepatic cholangiography to facilitate cannulation of the bile duct when previous attempts have failed.

METHODS

Over a 7-year period, a total of 1753 ERCPs were performed. Twelve of these patients with a diagnosis of choledocholithiasis were poor candidates for surgery. Percutaneous transhepatic cholangiography as well as ERCP with precut papillotomy failed to resolve biliary obstruction. In a further 2 cases the percutaneous approach was used by means of a T-tube positioned at a prior cholecystectomy.

OBSERVATIONS

The combined procedure was successful in 13 patients (93%). It was unsuccessful in 1 patient because of a stone lodged distally near the papilla. There was only 1 complication (7%), a retroperitoneal perforation that occurred during papillotomy; no mortality was directly attributable to the technique.

CONCLUSIONS

The rendezvous technique is recommended for patients who are not eligible for surgery when ERCP is unsuccessful and when it is impossible to resolve biliary obstruction by percutaneous transhepatic cholangiography.

An open standard platform for interoperability of medical devices

Patient care in Intensive Care Units and Operating Rooms requires sophisticated instrumentation for monitoring, treatment and control. A major technical problem is the communication between devices, since the connection of medical devices from different manufacturers has similar problems to the communication between people from different countries who do not share a common language. Several proprietary solutions have been developed by initiatives from well-known international companies. These proprietary, non-open solutions have not gained general acceptability and have failed to draw upon the immense resources for instrumentation development which are available in the industry. Consequently, a set of open European standards for Medical Device Intercommunication has recently been created (ratified 1999) to provide the ability to connect devices to each other freely and to exchange data between them. The development of such standards has lead to the design and implementation of a network platform over which those standards could be tested and validated. At the same time guidelines have been defined for the development and deployment of open solutions for any kind of medical device, including existing legacy devices. The design and testing of this open standards implementation is described in this paper.

Genomes OnLine Database (GOLD): a monitor of genome projects world-wide

GOLD is a comprehensive resource for accessing information related to completed and ongoing genome projects world-wide. The database currently provides information on 350 genome projects, of which 48 have been completely sequenced and their analysis published. GOLD was created in 1997 and since April 2000 it has been licensed to Integrated Genomics. The database is freely available through the URL: http://igweb.integratedgenomics.com/GOLD/.

Molecular characterization of non-B HIV type 1 subtypes from Africa in Spain

All of the known HIV-1 subtypes are present in sub-Saharan Africa. The B subtype is predominant in the United States and Europe, but previous studies have revealed that other subtypes are also in circulation. We report here on the genetic characterization of eight non-B subtype VIH-1 virus strains detected during 1999 in patients living in Spain and having epidemiological relationships with African countries. Five isolates clustering with recombinant form CRF02-AG came from West and Central Africa. One isolate was characterized as being of the D subtype in the gp41 region, and clustered with subtype A outside the CRF02-AG recombinant form, in regions C2V3 and p17. Another isolate was a G subtype, and the remaining isolate was an O subtype. In Spain, the B subtype is the most frequently detected HIV-1 subtype, although in more recent years non-B subtypes have been introduced through immigrant HIV-1-infected individuals coming from African countries, or through infected persons having relationships with endemically affected areas.

Correlation of central venous pressure with Doppler waveform of the common femoral veins

The objects of this prospective study were to determine the nature of the flow in the right femoral vein and to correlate the flow velocity with the venous pressure measured in the right atrium. We performed 236 pulsed Doppler ultrasonographic examinations in 1 year on patients with a venous catheter with the distal tip in the right atrium. In the Doppler wave readouts we analyzed wave frequency, velocity components, and relationships among them and the existence of pulsatile flow. These parameters were then compared to the right atrium pressure. We investigated the correlation between the atrium pressure and the flow velocity obtained from the Doppler waveforms of the common femoral veins, obtaining a significant correlation (P<0.0001) with the following: the atrium systolic wave a, the atrium diastolic wave v, the pulsatility ratio (PR = Vmin/Vmax) and the pulsatility index (PI = [Vmax - Vmin] /Vavg). The receiver operating characteristic showed that the pulsed Doppler ultrasonography is not a sensitive technique in diagnosis high atrium pressures. In addition, both cardiac and respiratory phasicity of the venous wave was observed. A significant inverse relation was found between the pulsatile flow and high atrium pressure. Nonetheless, the low sensitivity of this technique does not allow the use of pulsatile Doppler ultrasonography in the common femoral vein for diagnosing increases of the atrium pressure.