322 research outputs found

    The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots

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    During plant immunity, surface-localized pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs). The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs) EFR and XA21 from Arabidopsis thaliana (Arabidopsis) and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto) DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots

    Pediatric interventional radiography equipment: safety considerations

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    This paper discusses pediatric image quality and radiation dose considerations in state-of-the-art fluoroscopic imaging equipment. Although most fluoroscopes are capable of automatically providing good image quality on infants, toddlers, and small children, excessive radiation dose levels can result from design deficiencies of the imaging device or inappropriate configuration of the equipment’s capabilities when imaging small body parts. Important design features and setup choices at installation and during the clinical use of the imaging device can improve image quality and reduce radiation exposure levels in pediatric patients. Pediatric radiologists and cardiologists, with the help of medical physicists, need to understand the issues involved in creating good image quality at reasonable pediatric patient doses. The control of radiographic technique factors by the generator of the imaging device must provide a large dynamic range of mAs values per exposure pulse during both fluoroscopy and image recording as a function of patient girth, which is the thickness of the patient in the posterior–anterior projection at the umbilicus (less than 10 cm to greater than 30 cm). The range of pulse widths must be limited to less than 10 ms in children to properly freeze patient motion. Variable rate pulsed fluoroscopy can be leveraged to reduce radiation dose to the patient and improve image quality. Three focal spots with nominal sizes of 0.3 mm to 1 mm are necessary on the pediatric unit. A second, lateral imaging plane might be necessary because of the child’s limited tolerance of contrast medium. Spectral and spatial beam shaping can improve image quality while reducing the radiation dose. Finally, the level of entrance exposure to the image receptor of the fluoroscope as a function of operator choices, of added filter thickness, of selected pulse rate, of the selected field-of-view and of the patient girth all must be addressed at installation

    Gasless balloon laparoscopy

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    The concept of balloon laparoscopy (B-LSC) pursues the simplification of conventional diagnostic laparoscopy (LSC). The pneumoperitoneum is replaced by a transparent balloon, which is positioned in front of the optical system. It shall be shown that with this arrangement diagnostic LSC can be performed outside of the operating room without requiring general anesthesia.An inflatable balloon was developed for a 30°/3.5-mm rod lens. Intra-abdominally the balloon was expanded to a diameter of 30 mm by air insufflation, and B-LSC was performed. Twelve patients were examined in general anesthesia before laparoscopic surgery. Twelve patients were subjected to B-LSC fully awake or with sedation (midazolam or propofol/S-ketamine) as a “second-look” procedure by way of a flexible trocar (port) left in the abdominal wall at the end of previous operation. Eight patients have been first provided with a trocar under sedation (midazolam or propofol/S-ketamine) combined with local anesthesia, and B-LSC was performed before laparoscopic surgery.On a scale of 1–5, the general impression was rated 1.9, the navigability to the different abdominal organs 2.5, the resolution 1.5, the stability of the system optic/trocar 2.1, the suitability of the balloon format 1.9, and the stability of the balloon against lateral shear forces 2.4. The degree of painfulness of the examination was rated 2.8, the tolerance of the port 1.4, and the degree of painfulness of trocar placement at 2.5. On a scale of 1 to 3, the strain of the abdominal musculature was rated 1.4 and the obstruction by adhesions 1.7.B-LSC is technically practicable with good imaging qualities and without requiring pneumoperitoneum. It is tolerated in great extent under slight sedation and particularly well under deep sedation. The procedure is suitable for diagnostics of unclear abdominal conditions, as a second-look LSC and also as a staging LSC

    Correlating corneal arcus with atherosclerosis in familial hypercholesterolemia

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    Abstract Background A relationship between corneal arcus and atherosclerosis has long been suspected but is controversial. The homozygous familial hypercholesterolemia patients in this study present a unique opportunity to assess this issue. They have both advanced atherosclerosis and corneal arcus. Methods This is a cross-sectional study of 17 patients homozygous for familial hypercholesterolemia presenting to the Clinical Center of the National Institutes of Health. Plasma lipoproteins, circumferential extent of arcus, thoracic aorta and coronary calcific atherosclerosis score, and Achilles tendon width were measured at the National Institutes of Health. Results Patients with corneal arcus had higher scores for calcific atherosclerosis (mean 2865 compared to 412), cholesterol-year score (mean 11830 mg-yr/dl compared to 5707 mg-yr/dl), and Achilles tendon width (mean 2.54 cm compared to 1.41 cm) than those without. Corneal arcus and Achilles tendon width were strongly correlated and predictive of each other. Although corneal arcus was correlated with calcific atherosclerosis (r = 0.67; p = 0.004), it was not as highly correlated as was the Achilles tendon width (r = 0.855; p Conclusion Corneal arcus reflects widespread tissue lipid deposition and is correlated with both calcific atherosclerosis and xanthomatosis in these patients. Patients with more severe arcus tend to have more severe calcific atherosclerosis. Corneal arcus is not as good an indicator of calcific atherosclerosis as Achilles tendon thickness, but its presence suggests increased atherosclerosis in these hypercholesterolemic patients.</p

    Diversification and Specialization of Plant RBR Ubiquitin Ligases

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    Background: RBR ubiquitin ligases are components of the ubiquitin-proteasome system present in all eukaryotes. They are characterized by having the RBR (RING – IBR – RING) supradomain. In this study, the patterns of emergence of RBR genes in plants are described. Methodology/Principal Findings: Phylogenetic and structural data confirm that just four RBR subfamilies (Ariadne, ARA54, Plant I/Helicase and Plant II) exist in viridiplantae. All of them originated before the split that separated green algae from the rest of plants. Multiple genes of two of these subfamilies (Ariadne and Plant II) appeared in early plant evolution. It is deduced that the common ancestor of all plants contained at least five RBR genes and the available data suggest that this number has been increasing slowly along streptophyta evolution, although losses, especially of Helicase RBR genes, have also occurred in several lineages. Some higher plants (e. g. Arabidopsis thaliana, Oryza sativa) contain a very large number of RBR genes and many of them were recently generated by tandem duplications. Microarray data indicate that most of these new genes have low-level and sometimes specific expression patterns. On the contrary, and as occurs in animals, a small set of older genes are broadly expressed at higher levels. Conclusions/Significance: The available data suggests that the dynamics of appearance and conservation of RBR genes is quite different in plants from what has been described in animals. In animals, an abrupt emergence of many structurall

    UGT1A and TYMS genetic variants predict toxicity and response of colorectal cancer patients treated with first-line irinotecan and fluorouracil combination therapy

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    BACKGROUND: The impact of thymidylate synthase (TYMS) and UDP-glucoronosyltransferase 1A (UGT1A) germline polymorphisms on the outcome of colorectal cancer (CRC) patients treated with irinotecan plus 5-fluorouracil (irinotecan/5FU) is still controversial. Our objective was to define a genetic-based algorithm to select patients to be treated with irinotecan/5FU. METHODS: Genotyping of TYMS (5'TRP and 3'UTR), UGT1A1*28, UGT1A9*22 and UGT1A7*3 was performed in 149 metastatic CRC patients treated with irinotecan/5FU as first-line chemotherapy enrolled in a randomised phase 3 study. Their association with response, toxicity and survival was investigated by univariate and multivariate statistical analysis. RESULTS: TYMS 3TRP/3TRP genotype was the only independent predictor of tumour response (OR=5.87, 95% confidence interval (CI)=1.68-20.45; P=0.005). UGT1A1*28/*28 was predictive for haematologic toxicity (OR=6.27, 95% CI=1.09-36.12; P=0.04), specifically for neutropenia alone (OR=6.40, 95% CI=1.11-37.03; P=0.038) or together with diarrhoea (OR=18.87, 95% CI=2.14-166.67; P=0.008). UGT1A9*1/*1 was associated with non-haematologic toxicity (OR=2.70, 95% CI=1.07-6.82; P=0.035). Haplotype VII (all non-favourable alleles) was associated with non-haematologic toxicity (OR=2.11, 95% CI-1.12-3.98; P-0.02). CONCLUSION: TYMS and UGT1A polymorphisms influence on tumour response and toxicities derived from irinotecan/5FU treatment in CRC patients. A genetic-based algorithm to optimise treatment individualisation is proposed. British Journal of Cancer (2010) 103, 581-589. doi:10.1038/sj.bjc.6605776 www.bjcancer.com Published online 13 July 2010 (C) 2010 Cancer Research U

    The Arabidopsis thaliana F-Box Protein FBL17 Is Essential for Progression through the Second Mitosis during Pollen Development

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    In fungi and metazoans, the SCF-type Ubiquitin protein ligases (E3s) play a critical role in cell cycle regulation by degrading negative regulators, such as cell cycle-dependent kinase inhibitors (CKIs) at the G1-to-S-phase checkpoint. Here we report that FBL17, an Arabidopsis thaliana F-box protein, is involved in cell cycle regulation during male gametogenesis. FBL17 expression is strongly enhanced in plants co-expressing E2Fa and DPa, transcription factors that promote S-phase entry. FBL17 loss-of-function mutants fail to undergo pollen mitosis II, which generates the two sperm cells in mature A. thaliana pollen. Nonetheless, the single sperm cell-like cell in fbl17 mutants is functional but will exclusively fertilize the egg cell of the female gametophyte, giving rise to an embryo that will later abort, most likely due to the lack of functional endosperm. Seed abortion can, however, be overcome by mutations in FIE, a component of the Polycomb group complex, overall resembling loss-of-function mutations in the A. thaliana cyclin-dependent kinase CDKA;1. Finally we identified ASK11, as an SKP1-like partner protein of FBL17 and discuss a possible mechanism how SCFFBL17 may regulate cell division during male gametogenesis

    Overlap of cognitive concepts in chronic widespread pain: An exploratory study

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    <p>Abstract</p> <p>Background</p> <p>A wide variety of cognitive concepts have been shown to play an important role in chronic widespread pain (CWP). Although these concepts are generally considered to be distinct entities, some might in fact be highly overlapping. The objectives of this study were to (i) to establish inter-relationships between self-efficacy, cognitive coping styles, fear-avoidance cognitions and illness beliefs in patients with CWP and (ii) to explore the possibility of a reduction of these cognitions into a more limited number of domains.</p> <p>Methods</p> <p>Baseline measurement data of a prospective cohort study of 138 patients with CWP were used. Factor analysis was used to study the associations between 16 different cognitive concepts.</p> <p>Results</p> <p>Factor analysis resulted in three factors: 1) negative emotional cognitions, 2) active cognitive coping, and 3) control beliefs and expectations of chronicity.</p> <p>Conclusion</p> <p>Negative emotional cognitions, active cognitive coping, control beliefs and expectations of chronicity seem to constitute principal domains of cognitive processes in CWP. These findings contribute to the understanding of overlap and uniqueness of cognitive concepts in chronic widespread pain.</p

    Targeting poly(ADP-ribose) polymerase activity for cancer therapy

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    Poly(ADP-ribosyl)ation is a ubiquitous protein modification found in mammalian cells that modulates many cellular responses, including DNA repair. The poly(ADP-ribose) polymerase (PARP) family catalyze the formation and addition onto proteins of negatively charged ADP-ribose polymers synthesized from NAD+. The absence of PARP-1 and PARP-2, both of which are activated by DNA damage, results in hypersensitivity to ionizing radiation and alkylating agents. PARP inhibitors that compete with NAD+ at the enzyme’s activity site are effective chemo- and radiopotentiation agents and, in BRCA-deficient tumors, can be used as single-agent therapies acting through the principle of synthetic lethality. Through extensive drug-development programs, third-generation inhibitors have now entered clinical trials and are showing great promise. However, both PARP-1 and PARP-2 are not only involved in DNA repair but also in transcription regulation, chromatin modification, and cellular homeostasis. The impact on these processes of PARP inhibition on long-term therapeutic responses needs to be investigated
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