A variant of SCID with specific immune responses and predominance of gamma delta T cells.

We describe here a patient with a clinical and molecular diagnosis of recombinase activating gene 1-deficient (RAG1-deficient) SCID, who produced specific antibodies despite minimal B cell numbers. Memory B cells were detected and antibodies were produced not only against some vaccines and infections, but also against autoantigens. The patient had severely reduced levels of oligoclonal T cells expressing the alphabeta TCR but surprisingly normal numbers of T cells expressing the gammadelta TCR. Analysis at a clonal level and TCR complementarity-determining region-3 spectratyping for gammadelta T cells revealed a diversified oligoclonal repertoire with predominance of cells expressing a gamma4-delta3 TCR. Several gammadelta T cell clones displayed reactivity against CMV-infected cells. These observations are compatible with 2 non-mutually exclusive explanations for the gammadelta T cell predominance: a developmental advantage and infection-triggered, antigen-driven peripheral expansion. The patient carried the homozygous hypomorphic R561H RAG1 mutation leading to reduced V(D)J recombination but lacked all clinical features characteristic of Omenn syndrome. This report describes a new phenotype of RAG deficiency and shows that the ability to form specific antibodies does not exclude the diagnosis of SCID.

Cytocidal amino acid starvation of Saccharomyces cerevisiae and Candida albicans acetolactate synthase (ilv2{Delta}) mutants is influenced by the carbon source and rapamycin.

The isoleucine and valine biosynthetic enzyme acetolactate synthase (Ilv2p) is an attractive antifungal drug target, since the isoleucine and valine biosynthetic pathway is not present in mammals, Saccharomyces cerevisiae ilv2Delta mutants do not survive in vivo, Cryptococcus neoformans ilv2 mutants are avirulent, and both S. cerevisiae and Cr. neoformans ilv2 mutants die upon isoleucine and valine starvation. To further explore the potential of Ilv2p as an antifungal drug target, we disrupted Candida albicans ILV2, and demonstrated that Ca. albicans ilv2Delta mutants were significantly attenuated in virulence, and were also profoundly starvation-cidal, with a greater than 100-fold reduction in viability after only 4 h of isoleucine and valine starvation. As fungicidal starvation would be advantageous for drug design, we explored the basis of the starvation-cidal phenotype in both S. cerevisiae and Ca. albicans ilv2Delta mutants. Since the mutation of ILV1, required for the first step of isoleucine biosynthesis, did not suppress the ilv2Delta starvation-cidal defects in either species, the cidal phenotype was not due to alpha-ketobutyrate accumulation. We found that starvation for isoleucine alone was more deleterious in Ca. albicans than in S. cerevisiae, and starvation for valine was more deleterious than for isoleucine in both species. Interestingly, while the target of rapamycin (TOR) pathway inhibitor rapamycin further reduced S. cerevisiae ilv2Delta starvation viability, it increased Ca. albicans ilv1Delta and ilv2Delta viability. Furthermore, the recovery from starvation was dependent on the carbon source present during recovery for S. cerevisiae ilv2Delta mutants, reminiscent of isoleucine and valine starvation inducing a viable but non-culturable-like state in this species, while Ca. albicans ilv1Delta and ilv2 Delta viability was influenced by the carbon source present during starvation, supporting a role for glucose wasting in the Ca. albicans cidal phenotype.

Dynamics of Delta/Notch signaling on endomesoderm segregation in the sea urchin embryo.

Endomesoderm is the common progenitor of endoderm and mesoderm early in the development of many animals. In the sea urchin embryo, the Delta/Notch pathway is necessary for the diversification of this tissue, as are two early transcription factors, Gcm and FoxA, which are expressed in mesoderm and endoderm, respectively. Here, we provide a detailed lineage analysis of the cleavages leading to endomesoderm segregation, and examine the expression patterns and the regulatory relationships of three known regulators of this cell fate dichotomy in the context of the lineages. We observed that endomesoderm segregation first occurs at hatched blastula stage. Prior to this stage, Gcm and FoxA are co-expressed in the same cells, whereas at hatching these genes are detected in two distinct cell populations. Gcm remains expressed in the most vegetal endomesoderm descendant cells, while FoxA is downregulated in those cells and activated in the above neighboring cells. Initially, Delta is expressed exclusively in the micromeres, where it is necessary for the most vegetal endomesoderm cell descendants to express Gcm and become mesoderm. Our experiments show a requirement for a continuous Delta input for more than two cleavages (or about 2.5 hours) before Gcm expression continues in those cells independently of further Delta input. Thus, this study provides new insights into the timing mechanisms and the molecular dynamics of endomesoderm segregation during sea urchin embryogenesis and into the mode of action of the Delta/Notch pathway in mediating mesoderm fate.

Interleukin-15 receptor blockade in non-human primate kidney transplantation.

BACKGROUND: Interleukin (IL)-15 is a chemotactic factor to T cells. It induces proliferation and promotes survival of activated T cells. IL-15 receptor blockade in mouse cardiac and islet allotransplant models has led to long-term engraftment and a regulatory T-cell environment. This study investigated the efficacy of IL-15 receptor blockade using Mut-IL-15/Fc in an outbred non-human primate model of renal allotransplantation. METHODS: Male cynomolgus macaque donor-recipient pairs were selected based on ABO typing, major histocompatibility complex class I typing, and carboxy-fluorescein diacetate succinimidyl ester-based mixed lymphocyte responses. Once animals were assigned to one of six treatment groups, they underwent renal transplantation and bilateral native nephrectomy. Serum creatinine level was monitored twice weekly and as indicated, and protocol biopsies were performed. Rejection was defined as a increase in serum creatinine to 1.5 mg/dL or higher and was confirmed histologically. Complete blood counts and flow cytometric analyses were performed periodically posttransplant; pharmacokinetic parameters of Mut-IL-15/Fc were assessed. RESULTS: Compared with control animals, Mut-IL-15/Fc-treated animals did not demonstrate increased graft survival despite adequate serum levels of Mut-IL-15/Fc. Flow cytometric analysis of white blood cell subgroups demonstrated a decrease in CD8 T-cell and natural killer cell numbers, although this did not reach statistical significance. Interestingly, two animals receiving Mut-IL-15/Fc developed infectious complications, but no infection was seen in control animals. Renal pathology varied widely. CONCLUSIONS: Peritransplant IL-15 receptor blockade does not prolong allograft survival in non-human primate renal transplantation; however, it reduces the number of CD8 T cells and natural killer cells in the peripheral blood.

El reemplazo de pastizales anegadizos por plantaciones de álamos con suelos drenados en el Bajo Delta del río Paraná : cambios físicos y biogeoquímicos en el suelo y el ecosistema

En los humedales del Bajo del Paraná, el drenaje de los suelos, endicamiento y forestación constituyen el cambio de uso más característico. A partir del muestreo de suelos y vegetación en parcelas pareadas de pastizales anegadizos y plantaciones forestales que los reemplazaron tras el drenaje de los suelos, se exploraron los cambios en el volumen y contenido de materia orgánica del suelo y el balance del ecosistema de carbono, nitrógeno (N), fósforo (P), potasio, calcio y magnesio. El estrato de suelo orgánico original se redujo y el suelo mineral perdió volumen (-82 por ciento de porosidad en 0-10 cm de profundidad). Contrarrestó parcialmente estos efectos el aumento del contenido de materia orgánica (1,3 Mg C ha(-1) año(-1) favorecidos por el ingreso de raíces de álamos al suelo drenado (hídrico y libre de raíces en los pastizales). Comparadas con los pastizales, las forestaciones acumularon más carbono y nutrientes en la biomasa aérea y menos en broza y raíces. El balance final fue neutro para carbono y nitrógeno y negativo para fósforo (-0,7 Mg ha (-1) principalmente en los estratos profundos de suelo. Para el calcio, potasio y magnesio las ganancias en el suelo profundo, posiblemente asociadas a los cambios en el balance hídrico (mayor consumo freático, menor aporte superficial), determinaron balances positivos. La relación N/P en hojas de pastos y álamos (7 vs. 18) indicó el cambio de condiciones de limitación por nitrógeno a fósforo. En poco más de una década el drenaje, endicamiento y forestación de pastizales anegadizos redistribuyó el almacenamiento de carbono y nitrógeno sin afectar su magnitud, cambió las limitaciones nutricionales, y generó cambios físicos y químicos en los suelos. Estas modificaciones pueden acentuarse en plazos más largos influenciando la productividad y los servicios ecosistémicos de estos humedales.

Variabilidad genética de poblaciones de Melampsora spp. agente causal de la roya del álamo, en la zona del Delta Inferior del río Paraná

En la zona del Delta del Paraná, Argentina, el cultivo de álamo constituye el principal recurso productivo y económico. La roya del álamo, producida por especies de Melampsora spp., es la enfermedad fúngica de mayor importancia económica por su carácter epidemiológico. El cultivo de un limitado número de clones, altamente especializados y ecológicamente inestables, provocan la evolución de distintos patosistemas generando el reemplazo de ciertos clones por otros más resistentes. El objetivo de este trabajo fue estudiar la variabilidad genética molecular de la especie Melampsora, sobre 32 aislamientos de ejemplares pertenecientes a clones de Populus spp. durante los años 2007, 2008 y 2009, utilizando las técnicas de AFLPs y SSRs. La utilización de AFLPs permitió diferenciar 32 fenotipos moleculares, mostrando variabilidad genética en la población, mientras que a partir de la utilización de SSRs se confirmó la presencia de M. medusae y M. larici-populina en la zona de estudio. El análisis de agrupamientos (UPGMA) a partir de AFLPs permitió distinguir la cepa de Populus nigra del resto quedando como unidad aislada, a su vez se pudieron identificaron tres clusters de aislamientos provenientes de Populus deltoides, con tendencia a agruparse por origen genético y origen geográfico. El análisis de AMOVA confirmó las diferencias significativas para dichos agrupamientos. Los resultados del presente estudio confirman la existencia de variabilidad genética para los marcadores

Análisis del estado de competencia y manejo de la densidad en rodales de Populus deltoides Marsh, en el Delta del Paraná

p.271-277

Distribución de fertilizantes marcados con 15 N en la rotación ajo - moha

p.105-110

Acrinatrín 15 CE nuevo acaricida - insecticida en frutales de pepita : desarrollo a campo

p.203-213

El tipo de tareas como oportunidad de aprendizaje y competencias matemáticas de estudiantes de 15 años

Esta comunicación presenta resultados parciales de un estudio de dos casos (en España y Armenia), que ha tratado de conocer la importancia que tienen las oportunidades de aprendizaje (OTL) que ofrece el profesor en su aula (particularmente, en este documento tratamos el tipo de tareas que éste selecciona y propone) a la hora de facilitar la adquisición de las competencias matemáticas (CM) de sus estudiantes. Tomamos la información de observaciones de clases y entrevista (a dos profesores de Educación Secundaria) y de prueba (a los estudiantes de 15 años) y realizamos análisis de datos combinando técnicas cualitativas y cuantitativas. Los resultados de nuestra investigación, relativos al tipo de tareas, han constatado una fuerte relación de las CM de los estudiantes con la oportunidad de resolver cierto tipo de tareas (demanda cognitiva y situaciones/contextos en las que se plantean).

The influence of crank configuration on muscle activity and torque production during arm crank ergometry

This study investigated the effect of crank configuration on muscle activity and torque production during submaximal arm crank ergometry. Thirteen non-specifically trained male participants volunteered. During the research trials they completed a warm-up at 15 W before two 3-min exercise stages were completed at 50 and 100 W; subjects used either a synchronous or asynchronous pattern of cranking. During the final 30-s of each submaximal exercise stage electromyographic and torque production data were collected. After the data had been processed each parameter was analysed using separate 2-way ANOVA tests with repeated measures. The activity of all muscles increased in line with external workload, although a shift in the temporal pattern of muscle activity was noted between crank configurations. Patterns of torque production during asynchronous and synchronous cranking were distinct. Furthermore, peak, minimum and delta (peak-minimum) torque values were different (P < 0.05) between crank configurations at both workloads. For example, at 100 W, peak torque using synchronous [19.6 (4.3) Nm] cranking was higher (P < 0.05) compared to asynchronous [16.8 (1.6) Nm] cranking. In contrast minimum torque was lower (P < 0.05) at 100 W using synchronous [4.8 (1.7) Nm] compared to asynchronous [7.3 (1.2) Nm] cranking. There was a distinct bilateral asymmetry in torque production during asynchronous cranking with the dominant transmitting significantly more force to the crank arm. Taken together, these preliminary data demonstrate the complex nature of muscle activity during arm crank ergometry performed with an asynchronous or synchronous crank set-up. Further work is required to determine how muscle activity (EMG activity) and associated patterns of torque production influence physiological responses and functional capacity during arm crank ergometry.

Guide to the coastal and surface zooplankton of the south-western Indian Ocean. Occasional Publication of the Marine Biological Association 15

A guide compiled as an aid to researchers in the identification of the coastal and shallow water, south-western Indian Ocean pelagic zooplankton, as much of the identification literature covering this area of amazing biodiversity is currently spread through the scientific literature and not accessible without extensive library resources. Most zooplankton groups, except fish larvae and eggs, have been covered, but some specialist groups have not yet been dealt with in great detail. However, a selection of representative members of most groups have been given, so that organisms can at least be assigned to perhaps a particular genus within the main group. The species list is based on zooplankton sampling carried out round the coastal areas of the islands of Mahé and Aldabra (Seychelles), Rodrigues (Mauritius), Madagascar and from a sampling transect between Seychelles and Rodrigues. The guide therefore includes a high proportion of the island-coastal and surface water zooplankton of the whole Indian Ocean. The location where a particular species has been sampled has been noted and some species that have not been sampled, but are known to occur in the region, have been included. Comprehensive taxonomic information has not been presented, but sufficient information should be given to identify each species. Keys have not yet been included for genera, as further species will be added. A bibliography of relevant plankton references has also been included.