337 research outputs found

    Targeted Deletion of the Metastasis-Associated Phosphatase Ptp4a3 (PRL-3) Suppresses Murine Colon Cancer

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    Ptp4a3 (commonly known as PRL-3) is an enigmatic member of the Ptp4a family of prenylated protein tyrosine phosphatases that are highly expressed in many human cancers. Despite strong correlations with tumor metastasis and poor patient prognosis, there is very limited understanding of this gene family's role in malignancy. Therefore, we created a gene-targeted murine knockout model for Ptp4a3, the most widely studied Ptp4a family member. Mice deficient for Ptp4a3 were grossly normal. Fewer homozygous-null males were observed at weaning, however, and they maintained a decreased body mass. Although Ptp4a3 is normally associated with late-stage cancer and metastasis, we observed increased Ptp4a3 expression in the colon of wildtype mice immediately following treatment with the carcinogen azoxymethane. To investigate the role of Ptp4a3 in malignancy, we used the most commonly studied murine colitis-associated colon cancer model. Wildtype mice treated with azoxymethane and dextran sodium sulfate developed approximately 7-10 tumors per mouse in the distal colon. The resulting tumor tissue had 4-fold more Ptp4a3 mRNA relative to normal colon epithelium and increased PTP4A3 protein. Ptp4a3-null mice developed 50% fewer colon tumors than wildtype mice after exposure to azoxymethane and dextran sodium sulfate. Tumors from the Ptp4a3-null mice had elevated levels of both IGF1Rβ and c-MYC compared to tumors replete with Ptp4a3, suggesting an enhanced cell signaling pathway engagement in the absence of the phosphatase. These results provide the first definitive evidence implicating Ptp4a3 in colon tumorigenesis and highlight the potential value of the phosphatase as a therapeutic target for early stage malignant disease. © 2013 Zimmerman et al

    Site-specific prolapse surgery. I. Reliability and durability of native tissue paravaginal repair

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    Introduction and hypothesis: This study aims to compare native tissue abdominal and vaginal paravaginal repair, and to investigate whether surgical outcome was independent of operative route. Methods: Retrospective comparison of 111 displacement cysto-urethrocoeles, repaired between 1997 and 2007. Treatment was by surgeon assignment, 52 women having abdominal (APVR) and 59 vaginal paravaginal repairs. Main outcome measures were same-site prolapse recurrence, time to failure and surgical complications. Initial reliability was evaluated by chi-square test, 10-year durability by Kaplan-Meier survival analysis and Cox proportional hazards model. Results: When examined in the Cox proportional hazards model, anatomic results of APVR were more durable than a mechanically analogous transvaginal operation done [95% CI=1.029-2.708 (p value=0.038)]. Kaplan-Meier curves plateaued within 38 months. Symptom resolution was broadly equivalent. Surgical complication rate was 3.6%. Conclusions: Site-specific re-suture of torn native tissue has genuine curative potential. Most of the long-term success was attributable to site-specific repair, rather than nonspecific scar formation.9 page(s

    The transcription factor Spores Absent A is a PKA dependent inducer of Dictyostelium sporulation

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    Abstract Sporulation in Dictyostelium fruiting bodies evolved from amoebozoan encystation with both being induced by cAMP acting on PKA, but with downstream components still being unknown. Using tagged mutagenesis to find missing pathway components, we identified a sporeless mutant defective in a nuclear protein, SpaA. Expression of prespore genes was strongly reduced in spaA- cells, while expression of many spore stage genes was absent. Chromatin immunoprecipitation (ChIP) of a SpaA-YFP gene fusion showed that (pre)spore gene promoters bind directly to SpaA, identifying SpaA as a transcriptional regulator. SpaA dependent spore gene expression required PKA in vivo and was stimulated in vitro by the membrane-permeant PKA agonist 8Br-cAMP. The PKA agonist also promoted SpaA binding to (pre)spore promoters, placing SpaA downstream of PKA. Sequencing of SpaA-YFP ChIPed DNA fragments revealed that SpaA binds at least 117 (pre)spore promoters, including those of other transcription factors that activate some spore genes. These factors are not in turn required for spaA expression, identifying SpaA as the major trancriptional inducer of sporulation

    Farseer-NMR: automatic treatment, analysis and plotting of large, multi-variable NMR data

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    We present Farseer-NMR (https://git.io/vAueU), a software package to treat, evaluate and combine NMR spectroscopic data from sets of protein-derived peaklists covering a range of experimental conditions. The combined advances in NMR and molecular biology enable the study of complex biomolecular systems such as flexible proteins or large multibody complexes, which display a strong and functionally relevant response to their environmental conditions, e.g. the presence of ligands, site-directed mutations, post translational modifications, molecular crowders or the chemical composition of the solution. These advances have created a growing need to analyse those systems’ responses to multiple variables. The combined analysis of NMR peaklists from large and multivariable datasets has become a new bottleneck in the NMR analysis pipeline, whereby information-rich NMR-derived parameters have to be manually generated, which can be tedious, repetitive and prone to human error, or even unfeasible for very large datasets. There is a persistent gap in the development and distribution of software focused on peaklist treatment, analysis and representation, and specifically able to handle large multivariable datasets, which are becoming more commonplace. In this regard, Farseer-NMR aims to close this longstanding gap in the automated NMR user pipeline and, altogether, reduce the time burden of analysis of large sets of peaklists from days/weeks to seconds/minutes. We have implemented some of the most common, as well as new, routines for calculation of NMR parameters and several publication-quality plotting templates to improve NMR data representation. Farseer-NMR has been written entirely in Python and its modular code base enables facile extension

    To automate or not to automate: this is the question

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    New protocols and instrumentation significantly boost the outcome of structural biology, which has resulted in significant growth in the number of deposited Protein Data Bank structures. However, even an enormous increase of the productivity of a single step of the structure determination process may not significantly shorten the time between clone and deposition or publication. For example, in a medium size laboratory equipped with the LabDB and HKL-3000 systems, we show that automation of some (and integration of all) steps of the X-ray structure determination pathway is critical for laboratory productivity. Moreover, we show that the lag period after which the impact of a technology change is observed is longer than expected

    Depression symptomatology and diagnosis: discordance between patients and physicians in primary care settings

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    <p>Abstract</p> <p>Background</p> <p>To examine the agreement between depression symptoms using an assessment tool (PHQ-9), and physician documentation of the same symptoms during a clinic visit, and then to examine how the presence of these symptoms affects depression diagnosis in primary care settings.</p> <p>Methods</p> <p>Interviewer administered surveys and medical record reviews. A total of 304 participants were recruited from 2321 participants screened for depression at two large urban primary care community settings.</p> <p>Results</p> <p>Of the 2321 participants screened for depression 304 were positive for depression and of these 75.3% (n = 229) were significantly depressed (PHQ-9 score ≥ 10). Of these, 31.0% were diagnosed by a physician with a depressive disorder. A total of 57.6% (n = 175) of study participants had both significant depression symptoms and functional impairment. Of these 37.7% were diagnosed by physicians as depressed. Cohen's Kappa analysis, used to determine the agreement between depression symptoms elicited using the PHQ-9 and physician documentation of these symptoms showed only slight agreement (0.001–0.101) for all depression symptoms using standard agreement rating scales. Further analysis showed that only suicidal ideation and hypersomnia or insomnia were associated with an increased likelihood of physician depression diagnosis (OR 5.41 P sig < .01 and (OR 2.02 P sig < .05 respectively). Other depression symptoms and chronic medical conditions had no affect on physician depression diagnosis.</p> <p>Conclusion</p> <p>Two-thirds of individuals with depression are undiagnosed in primary care settings. While functional impairment increases the rate of physician diagnosis of depression, the agreement between a structured assessment and physician elicited and or documented symptoms during a clinical encounter is very low. Suicidality, hypersomnia and insomnia are associated with an increase in the rate of depression diagnosis even when physician and self report of the symptom differ. Interventions that emphasize the use of routine structured screening of primary care patients might also improve the rate of diagnosis of depression in these settings. Further studies are needed to explore depression symptom assessment during physician patient encounter in primary care settings.</p

    Identification of G1-Regulated Genes in Normally Cycling Human Cells

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    BACKGROUND: Obtaining synchronous cell populations is essential for cell-cycle studies. Methods such as serum withdrawal or use of drugs which block cells at specific points in the cell cycle alter cellular events upon re-entry into the cell cycle. Regulatory events occurring in early G1 phase of a new cell cycle could have been overlooked. METHODOLOGY AND FINDINGS: We used a robotic mitotic shake-off apparatus to select cells in late mitosis for genome-wide gene expression studies. Two separate microarray experiments were conducted, one which involved isolation of RNA hourly for several hours from synchronous cell populations, and one experiment which examined gene activity every 15 minutes from late telophase of mitosis into G1 phase. To verify synchrony of the cell populations under study, we utilized methods including BrdU uptake, FACS, and microarray analyses of histone gene activity. We also examined stress response gene activity. Our analysis enabled identification of 200 early G1-regulated genes, many of which currently have unknown functions. We also confirmed the expression of a set of genes candidates (fos, atf3 and tceb) by qPCR to further validate the newly identified genes. CONCLUSION AND SIGNIFICANCE: Genome-scale expression analyses of the first two hours of G1 in naturally cycling cells enabled the discovery of a unique set of G1-regulated genes, many of which currently have unknown functions, in cells progressing normally through the cell division cycle. This group of genes may contain future targets for drug development and treatment of human disease

    McCune-Albright syndrome

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    McCune-Albright syndrome (MAS) is classically defined by the clinical triad of fibrous dysplasia of bone (FD), café-au-lait skin spots, and precocious puberty (PP). It is a rare disease with estimated prevalence between 1/100,000 and 1/1,000,000. FD can involve a single or multiple skeletal sites and presents with a limp and/or pain, and, occasionally, a pathologic fracture. Scoliosis is common and may be progressive. In addition to PP (vaginal bleeding or spotting and development of breast tissue in girls, testicular and penile enlargement and precocious sexual behavior in boys), other hyperfunctioning endocrinopathies may be involved including hyperthyroidism, growth hormone excess, Cushing syndrome, and renal phosphate wasting. Café-au-lait spots usually appear in the neonatal period, but it is most often PP or FD that brings the child to medical attention. Renal involvement is seen in approximately 50% of the patients with MAS. The disease results from somatic mutations of the GNAS gene, specifically mutations in the cAMP regulating protein, Gs alpha. The extent of the disease is determined by the proliferation, migration and survival of the cell in which the mutation spontaneously occurs during embryonic development. Diagnosis of MAS is usually established on clinical grounds. Plain radiographs are often sufficient to make the diagnosis of FD and biopsy of FD lesions can confirm the diagnosis. The evaluation of patients with MAS should be guided by knowledge of the spectrum of tissues that may be involved, with specific testing for each. Genetic testing is possible, but is not routinely available. Genetic counseling, however, should be offered. Differential diagnoses include neurofibromatosis, osteofibrous dysplasia, non-ossifying fibromas, idiopathic central precocious puberty, and ovarian neoplasm. Treatment is dictated by the tissues affected, and the extent to which they are affected. Generally, some form of surgical intervention is recommended. Bisphosphonates are frequently used in the treatment of FD. Strengthening exercises are recommended to help maintaining the musculature around the FD bone and minimize the risk for fracture. Treatment of all endocrinopathies is required. Malignancies associated with MAS are distinctly rare occurrences. Malignant transformation of FD lesions occurs in probably less than 1% of the cases of MAS

    Periodic trends and easy estimation of relative stabilities in 11-vertex nido-p-block-heteroboranes and -borates

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    Density functional theory computations were carried out for 11-vertex nido-p-block-hetero(carba)boranes and -borates containing silicon, germanium, tin, arsenic, antimony, sulfur, selenium and tellurium heteroatoms. A set of quantitative values called “estimated energy penalties” was derived by comparing the energies of two reference structures that differ with respect to one structural feature only. These energy penalties behave additively, i.e., they allow us to reproduce the DFT-computed relative stabilities of 11-vertex nido-heteroboranes in general with good accuracy and to predict the thermodynamic stabilities of unknown structures easily. Energy penalties for neighboring heteroatoms (HetHet and HetHet′) decrease down the group and increase along the period (indirectly proportional to covalent radii). Energy penalties for a five- rather than four-coordinate heteroatom, [Het5k(1) and Het5k(2)], generally, increase down group 14 but decrease down group 16, while there are mixed trends for group 15 heteroatoms. The sum of HetHet′ energy penalties results in different but easily predictable open-face heteroatom positions in the thermodynamically most stable mixed heterocarbaboranes and -borates with more than two heteroatoms
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