315 research outputs found
Floral homeotic C function genes repress specific B function genes in the carpel whorl of the basal eudicot California poppy (Eschscholzia californica)
<p>Abstract</p> <p>Background</p> <p>The floral homeotic C function gene <it>AGAMOUS </it>(<it>AG</it>) confers stamen and carpel identity and is involved in the regulation of floral meristem termination in <it>Arabidopsis</it>. <it>Arabidopsis ag </it>mutants show complete homeotic conversions of stamens into petals and carpels into sepals as well as indeterminacy of the floral meristem. Gene function analysis in model core eudicots and the monocots rice and maize suggest a conserved function for <it>AG </it>homologs in angiosperms. At the same time gene phylogenies reveal a complex history of gene duplications and repeated subfunctionalization of paralogs.</p> <p>Results</p> <p><it>EScaAG1 </it>and <it>EScaAG2</it>, duplicate <it>AG </it>homologs in the basal eudicot <it>Eschscholzia californica </it>show a high degree of similarity in sequence and expression, although <it>EScaAG2 </it>expression is lower than <it>EScaAG1 </it>expression. Functional studies employing virus-induced gene silencing (VIGS) demonstrate that knock down of <it>EScaAG1 </it>and <it>2 </it>function leads to homeotic conversion of stamens into petaloid structures and defects in floral meristem termination. However, carpels are transformed into petaloid organs rather than sepaloid structures. We also show that a reduction of <it>EScaAG1 </it>and <it>EScaAG2 </it>expression leads to significantly increased expression of a subset of floral homeotic B genes.</p> <p>Conclusions</p> <p>This work presents expression and functional analysis of the two basal eudicot <it>AG </it>homologs. The reduction of <it>EScaAG1 </it>and <it>2 </it>functions results in the change of stamen to petal identity and a transformation of the central whorl organ identity from carpel into petal identity. Petal identity requires the presence of the floral homeotic B function and our results show that the expression of a subset of B function genes extends into the central whorl when the C function is reduced. We propose a model for the evolution of B function regulation by C function suggesting that the mode of B function gene regulation found in <it>Eschscholzia </it>is ancestral and the C-independent regulation as found in <it>Arabidopsis </it>is evolutionarily derived.</p
Floral homeotic C function genes repress specific B function genes in the carpel whorl of the basal eudicot California poppy (Eschscholzia californica)
<p>Abstract</p> <p>Background</p> <p>The floral homeotic C function gene <it>AGAMOUS </it>(<it>AG</it>) confers stamen and carpel identity and is involved in the regulation of floral meristem termination in <it>Arabidopsis</it>. <it>Arabidopsis ag </it>mutants show complete homeotic conversions of stamens into petals and carpels into sepals as well as indeterminacy of the floral meristem. Gene function analysis in model core eudicots and the monocots rice and maize suggest a conserved function for <it>AG </it>homologs in angiosperms. At the same time gene phylogenies reveal a complex history of gene duplications and repeated subfunctionalization of paralogs.</p> <p>Results</p> <p><it>EScaAG1 </it>and <it>EScaAG2</it>, duplicate <it>AG </it>homologs in the basal eudicot <it>Eschscholzia californica </it>show a high degree of similarity in sequence and expression, although <it>EScaAG2 </it>expression is lower than <it>EScaAG1 </it>expression. Functional studies employing virus-induced gene silencing (VIGS) demonstrate that knock down of <it>EScaAG1 </it>and <it>2 </it>function leads to homeotic conversion of stamens into petaloid structures and defects in floral meristem termination. However, carpels are transformed into petaloid organs rather than sepaloid structures. We also show that a reduction of <it>EScaAG1 </it>and <it>EScaAG2 </it>expression leads to significantly increased expression of a subset of floral homeotic B genes.</p> <p>Conclusions</p> <p>This work presents expression and functional analysis of the two basal eudicot <it>AG </it>homologs. The reduction of <it>EScaAG1 </it>and <it>2 </it>functions results in the change of stamen to petal identity and a transformation of the central whorl organ identity from carpel into petal identity. Petal identity requires the presence of the floral homeotic B function and our results show that the expression of a subset of B function genes extends into the central whorl when the C function is reduced. We propose a model for the evolution of B function regulation by C function suggesting that the mode of B function gene regulation found in <it>Eschscholzia </it>is ancestral and the C-independent regulation as found in <it>Arabidopsis </it>is evolutionarily derived.</p
Silicon nitride micromesh bolometer arrays for SPIRE
We are developing arrays of bolometers based on silicon nitride micromesh absorbers for the Spectral & Photometric Imaging Receiver (SPIRE) on the Far Infra-Red and Submillimeter Space Telescope (FIRST). The bolometers are coupled to a close-packed array of 1 f(lambda) feedhorns which views the primary mirror through a cooled aperture stop. Feedhorn-coupled bolometers minimize the detector area and throughput and have good optical efficiency. A 1 f(lambda) feedhorn array provides, higher mapping speed than a 2 f(lambda) feedhorn array and reduces the number of jitters required to produce a fully sampled map, but at the cost of more detectors. Individual silicon nitride micromesh bolometers are already able to meet the performance requirements of SPIRE. In parallel we are developing transition-edge detectors read out by SQUID current amplifier. The relatively large cooling power available at 300 mK enables the array to be coupled to a cold SQUID multiplexer, creating a monolithic fully multiplexed array and making large format arrays possible for SPIRE
Everolimus in Combination with Cyclosporin A as Pre- and Posttransplantation Immunosuppressive Therapy in Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplantation
Everolimus (RAD001) is an mTOR inhibitor that has been successfully used as an immunosuppressant in solid-organ transplantation. Data in allogeneic hematopoietic stem cell transplantation (HSCT) is limited. This study aimed to investigate pharmacokinetics, safety, and efficacy of RAD001 in a canine allogeneic HSCT model. First, pharmacokinetics of RAD001 were performed in healthy dogs in order to determine the appropriate dosing. Doses of 0.25 mg RAD001 twice daily in combination with 15 mg/kg cyclosporin A (CsA) twice daily were identified as appropriate starting doses to achieve the targeted range of RAD001 (3-8 μg/L) when orally administered. Subsequently, 10 dogs were transplanted using 2 Gy total body irradiation (TBI) for conditioning and 0.25 mg RAD001 twice daily plus 15 mg/kg CsA twice daily for pre- and posttransplantation immunosuppression. Seven of the 10 transplanted dogs were maintained at the starting RAD001 dose throughout the study. For the remaining 3 dogs, dose adjustments were necessary. RAD001 accumulation over time did not occur. All dogs initially engrafted. Five dogs eventually rejected the graft (weeks 10, 10, 13, 27, and 56). Two dogs died of pneumonia (weeks 8 and 72) but were chimeric until then. Total cholesterol rose from median 4.1 mmol/L (3.5-5.7 mmol/L) before HSCT to 6.0 mmol/l (5.0-8.5 mmol/l) at day 21 after HSCT, but remained always within normal range. Changes in creatinine and triglyceride values were not observed. Long-term engraftment rates were inferior to sirolimus/CsA and mycophenolate mofetil (MMF)/CsA regimen, respectively. RAD001/CsA caused a more pronounced reduction of platelet counts to median 2 × 109/L (range: 0-21 × 109/L) and longer time to platelet recovery of 21 days (range: 14-24 days) compared with MMF/CsA. CsA c2h levels were significantly enhanced in the RAD001/CsA regimen, but c0h and area under the curve from 0 to 12 hours (AUC0-12h) values did not differ compared with an MMF/CsA immunosuppression. In summary, immunosuppression consisting of RAD001 and CsA is well tolerated but not as efficient as with other established immunosuppressants in a canine nonmyeloablative HSCT regimen. Hence, our study does not support the application of RAD001/CsA as standard practice in this setting
Plasmonic bimetallic two-dimensional supercrystals for H2 generation
Sunlight-driven H-2 generation is a central technology to tackle our impending carbon-based energy collapse. Colloidal photocatalysts consisting of plasmonic and catalytic nanoparticles are promising for H-2 production at solar irradiances, but their performance is hindered by absorption and multiscattering events. Here we present a two-dimensional bimetallic catalyst by incorporating platinum nanoparticles into a well-defined supercrystal of gold nanoparticles. The bimetallic supercrystal exhibited an H-2 generation rate of 139mmolg(cat)(-1)h(-1) via formic acid dehydrogenation under visible light illumination and solar irradiance. This configuration makes it possible to study the interaction between the two metallic materials and the influence of this in catalysis. We observe a correlation between the intensity of the electric field in the hotspots and the boosted catalytic activity of platinum nanoparticles, while identifying a minor role of heat and gold-to-platinum charge transfer in the enhancement. Our results demonstrate the benefits of two-dimensional configurations with optimized architecture for liquid-phase photocatalysis
Rigidity versus flexibility: is this an issue in S1 (sigma-1) receptor ligand affinity and activity?
A set of stereoisomeric 2,5-diazabicyclo[2.2.2]octanes 14 and 15 was prepared in a chiral-pool synthesis starting from (S)- or (R)-aspartate. The key step in the synthesis was a Dieckmann-analogous cyclization of (dioxopiperazinyl)acetates 8, which involved trapping uf the intermediate hemiketal anion with Me3SiCl. The \u3c31 affinity was tested using membrane preparations from animal (guinea pig) and human origin. The binding of bicyclic compounds was analyzed by molecular dynamics simulations based on a 3D homology model of the \u3c31 receptor. The good correlation between Ki values observed in the \u3c31 assays and calculated free binding energy, coupled with the identification of four crucial ligand/receptor interactions allowed the formulation of structure affinity relationships. In an in vitro antitumor assay with seven human tumor cell lines, the bicyclic compounds inhibited selectively the growth of the cell line A427, which is due to induction of apoptosis. In this assay, the compounds behave like the known \u3c31 receptor antagonist haloperidol
SchussenAktivplus: reduction of micropollutants and of potentially pathogenic bacteria for further water quality improvement of the river Schussen, a tributary of Lake Constance, Germany
The project focuses on the efficiency of combined technologies to reduce the release of micropollutants and bacteria into surface waters via sewage treatment plants of different size and via stormwater overflow basins of different types. As a model river in a highly populated catchment area, the river Schussen and, as a control, the river Argen, two tributaries of Lake Constance, Southern Germany, are under investigation in this project. The efficiency of the different cleaning technologies is monitored by a wide range of exposure and effect analyses including chemical and microbiological techniques as well as effect studies ranging from molecules to communities
Evaluation of Galactomannan Testing, the Aspergillus-Specific Lateral-Flow Device Test and Levels of Cytokines in Bronchoalveolar Lavage Fluid for Diagnosis of Chronic Pulmonary Aspergillosis
Background: Diagnosis of chronic pulmonary aspergillosis (CPA) is challenging. Symptoms are unspecific or missing, radiological findings are variable and proof of mycological evidence is limited by the accuracy of diagnostic tests. The goal of this study was to investigate diagnostic performance of galactomannan (GM), the newly formatted Aspergillus-specific lateral-flow-device test (LFD), and a number of cytokines in bronchoalveolar lavage fluid (BALF) samples obtained from patients with CPA, patients with respiratory disorders without CPA and healthy individuals.Methods: Patients with CPA (n = 27) and controls (n = 27 with underlying respiratory diseases but without CPA, and n = 27 healthy volunteers) were recruited at the Medical University of Graz, Austria and the Research Center Borstel, Germany between 2010 and 2018. GM, LFD and cytokine testing was performed retrospectively at the Research Center Borstel.Results: Sensitivity and specificity of GM testing from BALF with a cut off level of ≥0.5 optical density index (ODI) was 41 and 100% and 30 and 100% with a cut off level of ≥1.0 ODI. ROC curve analysis showed an AUC 0.718 (95% CI 0.581–0.855) for GM for differentiating CPA patients to patients with other respiratory diseases without CPA. The LFD resulted positive in only three patients with CPA (7%) and was highly specific. CPA patients did not differ significantly in the BALF cytokine profile compared to patients with respiratory disorders without CPA, but showed significant higher values for IFN-γ, IL-1b, IL-6, IL-8, and TNF-α compared to healthy individuals.Conclusion: Both GM and LFD showed insufficient performance for diagnosing CPA, with sensitivities of BALF GM below 50%, and sensitivity of the LFD below 10%. The high specificities may, however, result in a high positive predictive value and thereby help to identify semi-invasive or invasive disease
Hipopara-Red, Real Life Experience in 322 Patients with Hypoparathyroidism
Context:Hypoparathyroidism is a rare disease and as such, its natural history, long term complications and correct clinical management remain unclear.ObjectiveTo describe the natural history and clinical characteristics of the disease.Design and settingTopresent a retrospective observational analysis from seven specialized centers in Buenos Aires, Argentina.Patientschronic hypoparathyroid patients followed up between 1985 and December 2018.Main Outcome Measuresdata on demographics, etiology, clinical complications, biochemical parameters, DXA values and treatment doses were collected.Results322 subjects with chronic hypoparathyroidism were included, 85.7 % were female. Mean age was 55.2 ± 16.8 years and mean age at diagnosis was 43.8 ± 16.8. Prevalence of surgical hypoparathyroidism was 90.7 %, most common causes being thyroid carcinoma and benign thyroid disease. A history of hypocalcemia requiring hospitalization was present in 25.7 % and 4.3 % had a history of seizures. Overall, 40.9 % had reported at least one neuromuscular symptom. Renal insufficiency was present in 22.4 % and was significantly associated with age (p<0.0001). Hyperphosphatemia was present in 42 %. A history of severe hypocalcemia, paresthesias, tetany, ganglia calcifications, seizures and cataracts was significantly higher in nonsurgical patients.ConclusionAlthough these patients were followed up by experienced physicians, clinical management was heterogeneous and probably insufficient to assess all the potential complications of this chronic disease. Almost 70 % of this group of patients met the experts´ indications for considering the use of rhPTH 1-84. Being aware of this fact is the first step to improve our medical management of this disease in the future.Fil: Zanchetta, María Belén. Universidad del Salvador; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Robbiani, Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentina. Universidad del Salvador; ArgentinaFil: Oliveri, María Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Giacoia, Evangelina. Hospital Nacional Profesor Alejandro Posadas; ArgentinaFil: Frigeri, Adriana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Kallsbrum, Silvia. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Carlos Durand; ArgentinaFil: Salerni, Helena. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Carlos Durand; ArgentinaFil: Lucas, Sabrina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; ArgentinaFil: Diaz, Adriana. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; ArgentinaFil: Perez, Betiana. Hospital Italiano; ArgentinaFil: Pieroni, Luisina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Arce Lange, María Auxiliadora. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Tormo, Silvina. Hospital Nacional Profesor Alejandro Posadas.; ArgentinaFil: Kitaigrodsky, Ariela. Hospital Italiano; ArgentinaFil: Galich, Ana María. Hospital Italiano; Argentin
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