105 research outputs found

    Identification of new ABA-and MEJA-activated sugarcane bZIP genes by data mining in the SUCEST database

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    Abstract Sugarcane is generally propagated by cuttings of the stalk containing one or more lateral buds, which will develop into a new plant. The transition from the dormant into the active stage constitutes a complex phenomenon characterized by changes in accumulation of phytohormones and several other physiological aspects. Abscisic acid (ABA) and methyl-jasmonate (MeJA) are major signaling molecules, which influence plant development and stress responses. These plant regulators modulate gene expression with the participation of many transcriptional factors. Basic leucine zipper proteins (bZIPs) form a large family of transcriptional factors involved in a variety of plant physiological processes, such as development and responses to stress. Query sequences consisting of fulllength protein sequence of each of the Arabidopsis bZIP families were utilized to screen the sugarcane EST database (SUCEST) and 86 sugarcane assembled sequences (SAS) coding for bZIPs were identified. cDNA arrays and RNA-gel blots were used to study the expression of these sugarcane bZIP genes during early plantlet development and in response to ABA and MeJA. Six bZIP genes were found to be differentially expressed during development. ABA and MeJA modulated the expression of eight sugarcane bZIP genes. Our findings provide novel insights into the expression of this large protein family of transcriptional factors in sugarcane

    Use of the q-Gaussian mutation in evolutionary algorithms

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    Copyright @ Springer-Verlag 2010.This paper proposes the use of the q-Gaussian mutation with self-adaptation of the shape of the mutation distribution in evolutionary algorithms. The shape of the q-Gaussian mutation distribution is controlled by a real parameter q. In the proposed method, the real parameter q of the q-Gaussian mutation is encoded in the chromosome of individuals and hence is allowed to evolve during the evolutionary process. In order to test the new mutation operator, evolution strategy and evolutionary programming algorithms with self-adapted q-Gaussian mutation generated from anisotropic and isotropic distributions are presented. The theoretical analysis of the q-Gaussian mutation is also provided. In the experimental study, the q-Gaussian mutation is compared to Gaussian and Cauchy mutations in the optimization of a set of test functions. Experimental results show the efficiency of the proposed method of self-adapting the mutation distribution in evolutionary algorithms.This work was supported in part by FAPESP and CNPq in Brazil and in part by the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant EP/E060722/1 and Grant EP/E060722/2

    Cloning approach and functional analysis of anti-intimin single-chain variable fragment (scFv)

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    <p>Abstract</p> <p>Background</p> <p>Intimin is an important virulence factor involved in the pathogenesis of enteropathogenic <it>Escherichia coli </it>(EPEC) and enterohemorrhagic <it>Escherichia coli </it>(EHEC). Both pathogens are still important causes of diarrhea in children and adults in many developing and industrialized countries. Considering the fact that antibodies are important tools in the detection of various pathogens, an anti-intimin IgG2b monoclonal antibody was previously raised in immunized mice with the conserved sequence of the intimin molecule (int<sub>388-667</sub>). In immunoblotting assays, this monoclonal antibody showed excellent specificity. Despite good performance, the monoclonal antibody failed to detect some EPEC and EHEC isolates harboring variant amino acids within the 338-667 regions of intimin molecules. Consequently, motivated by its use for diagnosis purposes, in this study we aimed to the cloning and expression of the single-chain variable fragment from this monoclonal antibody (scFv).</p> <p>Findings</p> <p>Anti-intimin hybridoma mRNA was extracted and reversely transcripted to cDNA, and the light and heavy chains of the variable fragment of the antibody were amplified using commercial primers. The amplified chains were cloned into <it>pGEM-T Easy </it>vector. Specific primers were designed and used in an amplification and chain linkage strategy, obtaining the scFv, which in turn was cloned into pAE vector. <it>E. coli </it>BL21(DE3)pLys strain was transformed with pAE scFv-intimin plasmid and subjected to induction of protein expression. Anti-intimin scFv, expressed as inclusion bodies (insoluble fraction), was denatured, purified and submitted to refolding. The protein yield was 1 mg protein per 100 mL of bacterial culture. To test the functionality of the scFv, ELISA and immunofluorescence assays were performed, showing that 275 ng of scFv reacted with 2 mg of purified intimin, resulting in an absorbance of 0.75 at 492 nm. The immunofluorescence assay showed a strong reactivity with EPEC E2348/69.</p> <p>Conclusion</p> <p>This study demonstrated that the recombinant anti-intimin antibody obtained is able to recognize the conserved region of intimin (Int<sub>388-667</sub>) in purified form and the EPEC isolate.</p

    History of sentinel node and validation of the technique

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    Sentinel node biopsy is a minimally invasive technique to select patients with occult lymph node metastases who may benefit from further regional or systemic therapy. The sentinel node is the first lymph node reached by metastasising cells from a primary tumour. Attempts to remove this node with a procedure based on standard anatomical patterns did not become popular. The development of the dynamic technique of intraoperative lymphatic mapping in the 1990s resulted in general acceptance of the sentinel node concept. This hypothesis of sequential tumour dissemination seems to be valid according to numerous studies of sentinel node biopsy with confirmatory regional lymph node dissection. This report describes the history and the validation of the technique, with particular reference to breast cancer

    Phase II study of intraperitoneal recombinant interleukin-12 (rhIL-12) in patients with peritoneal carcinomatosis (residual disease < 1 cm) associated with ovarian cancer or primary peritoneal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Pharmacokinetic advantages of intraperitoneal (IP) rhIL-12, tumor response to IP delivery of other cytokines as well as its potential anti-angiogenic effect provided the rationale for further evaluation of IPrhIL-12 in patients with persistent ovarian or peritoneal carcinoma.</p> <p>Methods</p> <p>A phase 2 multi-institutional trial (NCI Study #2251) of IP rIL-12 (300 nanogram/Kg weekly) was conducted in patients with ovarian carcinoma or primary peritoneal carcinoma.</p> <p>Patients treated with primary therapy for ovarian cancer who had no extraabdominal/parenchymal disease or bulky peritoneal disease were eligible. Four to 8 weeks from last chemotherapy, eligible patients underwent a laparotomy/laparoscopy. Patients with residual disease ≤ 1 cm were registered for the treatment phase 2–5 weeks post surgery. The effect of IP rIL-12 on the expression of TNFα , INFα , IL-10, IP-10, IL-8, FGF, VEGF was also studied.</p> <p>Results</p> <p>Thirty-four patients were registered for the first screening phase of the study. Median age was 56.6 years (range: 31–71); 12 completed the second phase and were evaluable for response/toxicity. Performance scores of IL-12 treated patients were 0 (11 pts) and 1 (1 pt). There were no treatment related deaths, peritonitis or significant catheter related complications. Toxicities included grade 4 neutropenia (1), grade 3 fatigue (4), headache (2), myalgia (2), non-neutropenic fever (1), drug fever (1), back pain (1), and dizziness (1). The best response observed was SD. Two patients had SD and 9 had PD, and 1 was evaluable for toxicity only.</p> <p>Peritoneal fluid cytokine measurements demonstrated a ≥ 3 fold relative increase post-rhIL-12: IFN-γ, 5/5 pts; TNF-α , 1/5; IL-10, 4/5; IL-8, 5/5; and VEGF, 3/5. IP10 levels were increased in 5/5 patients. Cytokine response profiles suggest either NK or T-cell mediated effects of IP rhIL-12. Cytokine/chemokine results also suggest a pleiotropic response since proteins with potential for either anti-tumor (IFN-γ , IP-10) or pro-tumor growth effects (VEGF, IL-8) were detected.</p> <p>Conclusion</p> <p>IP IL-12 can safely be administered at this dose and schedule to patients after first line chemotherapy for ovarian/peritoneal carcinoma. The maximum response was stable disease. Future IP therapies with rhIL-12 will require better understanding and control of pleiotropic effects of IL-12.</p

    HS1, a Lyn Kinase Substrate, Is Abnormally Expressed in B-Chronic Lymphocytic Leukemia and Correlates with Response to Fludarabine-Based Regimen

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    In B-Chronic Lymphocytic Leukemia (B-CLL) kinase Lyn is overexpressed, active, abnormally distributed, and part of a cytosolic complex involving hematopoietic lineage cell-specific protein 1 (HS1). These aberrant properties of Lyn could partially explain leukemic cells’ defective apoptosis, directly or through its substrates, for example, HS1 that has been associated to apoptosis in different cell types. To verify the hypothesis of HS1 involvement in Lyn-mediated leukemic cell survival, we investigated HS1 protein in 71 untreated B-CLL patients and 26 healthy controls. We found HS1 overexpressed in leukemic as compared to normal B lymphocytes (1.38±0.54 vs 0.86±0.29, p<0.01), and when HS1 levels were correlated to clinical parameters we found a higher expression of HS1 in poor-prognosis patients. Moreover, HS1 levels significantly decreased in ex vivo leukemic cells of patients responding to a fludarabine-containing regimen. We also observed that HS1 is partially localized in the nucleus of neoplastic B cells. All these data add new information on HS1 study, hypothesizing a pivotal role of HS1 in Lyn-mediated modulation of leukemic cells’ survival and focusing, one more time, the attention on the BCR-Lyn axis as a putative target for new therapeutic strategies in this disorder

    The Leucine Zipper Domains of the Transcription Factors GCN4 and c-Jun Have Ribonuclease Activity

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    Basic-region leucine zipper (bZIP) proteins are one of the largest transcription factor families that regulate a wide range of cellular functions. Owing to the stability of their coiled coil structure leucine zipper (LZ) domains of bZIP factors are widely employed as dimerization motifs in protein engineering studies. In the course of one such study, the X-ray structure of the retro-version of the LZ moiety of yeast transcriptional activator GCN4 suggested that this retro-LZ may have ribonuclease activity. Here we show that not only the retro-LZ but also the authentic LZ of GCN4 has weak but distinct ribonuclease activity. The observed cleavage of RNA is unspecific, it is not suppressed by the ribonuclease A inhibitor RNasin and involves the breakage of 3′,5′-phosphodiester bonds with formation of 2′,3′-cyclic phosphates as the final products as demonstrated by HPLC/electrospray ionization mass spectrometry. Several mutants of the GCN4 leucine zipper are catalytically inactive, providing important negative controls and unequivocally associating the enzymatic activity with the peptide under study. The leucine zipper moiety of the human factor c-Jun as well as the entire c-Jun protein are also shown to catalyze degradation of RNA. The presented data, which was obtained in the test-tube experiments, adds GCN4 and c-Jun to the pool of proteins with multiple functions (also known as moonlighting proteins). If expressed in vivo, the endoribonuclease activity of these bZIP-containing factors may represent a direct coupling between transcription activation and controlled RNA turnover. As an additional result of this work, the retro-leucine zipper of GCN4 can be added to the list of functional retro-peptides

    Deficit of social cognition in subjects with surgically treated frontal lobe lesions and in subjects affected by schizophrenia

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    The ability of humans to predict and explain other people’s behaviour by attributing independent mental states such as desires and beliefs to them, is considered to be due to our ability to construct a “Theory of Mind”. Recently, several neuroimaging studies have implicated the medial frontal lobes as playing a critical role in a dedicated “mentalizing” or “Theory of Mind” network in the human brain. In this study we compare the performance of patients with right and left medial prefrontal lobe lesions in theory of mind and in social cognition tasks, with the performance of people with schizophrenia. We report a similar social cognitive profile between patients with prefrontal lobe lesions and schizophrenic subjects in terms of understanding of false beliefs, in understanding social situations and in using tactical strategies. These findings are relevant for the functional anatomy of “Theory of Mind”
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