3,174 research outputs found

    Direct Comparison of Manganese Detoxification/Efflux Proteins and Molecular Characterization of ZnT10 as a Manganese Transporter

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    Manganese (Mn) homeostasis involves coordinated regulation of specific proteins involved in Mn influx and efflux. However, the proteins that are involved in detoxification/efflux have not been completely resolved, nor has the basis by which they select their metal substrate. Here, we compared six proteins, which were reported to be involved in Mn detoxification/efflux, by evaluating their ability to reduce Mn toxicity in chicken DT40 cells, finding that human ZnT10 (hZnT10) was the most significant contributor. A domain swapping and substitution analysis between hZnT10 and a zinc-specific transporter hZnT1 showed that residue N43, which corresponds to the His residue constituting the potential intramembranous zinc coordination site in other ZnT transporters, is necessary to impart hZnT10's unique Mn mobilization activity; residues C52 and L242 in transmembrane domains II and V play a subtler role in controlling the metal specificity of hZnT10. Interestingly, the H->N reversion mutant in hZnT1 conferred Mn transport activity and loss of zinc transport activity. These results provide important information about Mn detoxification/efflux mechanisms in vertebrate cells as well as the molecular characterization of hZnT10 as a Mn transporter

    Planetary Dynamics and Habitable Planet Formation In Binary Star Systems

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    Whether binaries can harbor potentially habitable planets depends on several factors including the physical properties and the orbital characteristics of the binary system. While the former determines the location of the habitable zone (HZ), the latter affects the dynamics of the material from which terrestrial planets are formed (i.e., planetesimals and planetary embryos), and drives the final architecture of the planets assembly. In order for a habitable planet to form in a binary star system, these two factors have to work in harmony. That is, the orbital dynamics of the two stars and their interactions with the planet-forming material have to allow terrestrial planet formation in the habitable zone, and ensure that the orbit of a potentially habitable planet will be stable for long times. We have organized this chapter with the same order in mind. We begin by presenting a general discussion on the motion of planets in binary stars and their stability. We then discuss the stability of terrestrial planets, and the formation of potentially habitable planets in a binary-planetary system.Comment: 56 pages, 29 figures, chapter to appear in the book: Planets in Binary Star Systems (Ed. N. Haghighipour, Springer publishing company

    Loss of the Putative Catalytic Domain of HDAC4 Leads to Reduced Thermal Nociception and Seizures while Allowing Normal Bone Development

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    Histone deacetylase 4 (HDAC4) has been associated with muscle & bone development [1]–[6]. N-terminal MEF2 and RUNX2 binding domains of HDAC4 have been shown to mediate these effects in vitro. A complete gene knockout has been reported to result in premature ossification and associated defects resulting in postnatal lethality [6]. We report a viral insertion mutation that deletes the putative deacetylase domain, while preserving the N-terminal portion of the protein. Western blot and immuno-precipitation analysis confirm expression of truncated HDAC4 containing N-terminal amino acids 1-747. These mutant mice are viable, living to at least one year of age with no gross defects in muscle or bone. At 2–4 months of age no behavioral or physiological abnormalities were detected except for an increased latency to respond to a thermal nociceptive stimulus. As the mutant mice aged past 5 months, convulsions appeared, often elicited by handling. Our findings confirm the sufficiency of the N-terminal domain for muscle and bone development, while revealing other roles of HDAC4

    Clinical practice: Protein-losing enteropathy in children

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    Protein-losing enteropathy (PLE) is a rare complication of a variety of intestinal disorders characterized by an excessive loss of proteins into the gastrointestinal tract due to impaired integrity of the mucosa. The clinical presentation of patients with PLE is highly variable, depending upon the underlying cause, but mainly consists of edema due to hypoproteinemia. While considering PLE, other causes of hypoproteinemia such as malnutrition, impaired synthesis, or protein loss through other organs like the kidney, liver, or skin, have to be excluded. The disorders causing PLE can be divided into those due to protein loss from intestinal lymphatics, like primary intestinal lymphangiectasia or congenital heart disease and those with protein loss due to an inflamed or abnormal mucosal surface. The diagnosis is confirmed by increased fecal concentrations of alpha-1-antitrypsin. After PLE is diagnosed, the underlying cause should be identified by stool cultures, serologic evaluation, cardiac screening, or radiographic imaging. Treatment of PLE consists of nutrition state maintenance by using a high protein diet with supplement of fat-soluble vitamins. In patients with lymphangiectasia, a low fat with medium chain triglycerides (MCT) diet should be prescribed. Besides dietary adjustments, appropriate treatment for the underlying etiology is necessary and supportive care to avoid complications of edema. PLE is a rare complication of various diseases, mostly gastrointestinal or cardiac conditions that result into loss of proteins in the gastrointestinal tract. Prognosis depends upon the severity and treatment options of the underlying disease

    Cosmic Rays: The Second Knee and Beyond

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    We conduct a review of experimental results on Ultra-High Energy Cosmic Rays (UHECR's) including measurements of the features of the spectrum, the composition of the primary particle flux and the search for anisotropy in event arrival direction. We find that while there is a general consensus on the features in the spectrum -- the Second Knee, the Ankle, and (to a lesser extent) the GZK Cutoff -- there is little consensus on the composition of the primaries that accompany these features. This lack of consensus on the composition makes interpretation of the agreed upon features problematic. There is also little direct evidence about potential sources of UHECRs, as early reports of arrival direction anisotropies have not been confirmed in independent measurements.Comment: 46 pages, 30 figures. Topical Review to appear in J. Physics

    A Global View of Cancer-Specific Transcript Variants by Subtractive Transcriptome-Wide Analysis

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    BACKGROUND: Alternative pre-mRNA splicing (AS) plays a central role in generating complex proteomes and influences development and disease. However, the regulation and etiology of AS in human tumorigenesis is not well understood. METHODOLOGY/PRINCIPAL FINDINGS: A Basic Local Alignment Search Tool database was constructed for the expressed sequence tags (ESTs) from all available databases of human cancer and normal tissues. An insertion or deletion in the alignment of EST/EST was used to identify alternatively spliced transcripts. Alignment of the ESTs with the genomic sequence was further used to confirm AS. Alternatively spliced transcripts in each tissue were then subtractively cross-screened to obtain tissue-specific variants. We systematically identified and characterized cancer/tissue-specific and alternatively spliced variants in the human genome based on a global view. We identified 15,093 cancer-specific variants of 9,989 genes from 27 types of human cancers and 14,376 normal tissue-specific variants of 7,240 genes from 35 normal tissues, which cover the main types of human tumors and normal tissues. Approximately 70% of these transcripts are novel. These data were integrated into a database HCSAS (http://202.114.72.39/database/human.html, pass:68756253). Moreover, we observed that the cancer-specific AS of both oncogenes and tumor suppressor genes are associated with specific cancer types. Cancer shows a preference in the selection of alternative splice-sites and utilization of alternative splicing types. CONCLUSIONS/SIGNIFICANCE: These features of human cancer, together with the discovery of huge numbers of novel splice forms for cancer-associated genes, suggest an important and global role of cancer-specific AS during human tumorigenesis. We advise the use of cancer-specific alternative splicing as a potential source of new diagnostic, prognostic, predictive, and therapeutic tools for human cancer. The global view of cancer-specific AS is not only useful for exploring the complexity of the cancer transcriptome but also widens the eyeshot of clinical research

    Metastasis to the breast from an adenocarcinoma of the lung with extensive micropapillary component: a case report and review of the literature

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    Breast metastasis from extra-mammary malignancy is rare. Based on the literature an incidence of 0.4-1.3% is reported. The primary malignancies most commonly metastasizing to the breast are leukemia-lymphoma, and malignant melanoma. We present a case of metastasis to the breast from a pulmonary adenocarcinoma, with extensive micropapillary component, diagnosed concomitantly with the primary tumor. A 73-year-old female presented with dyspnea and dry cough of 4 weeks duration and a massive pleural effusion was found on a chest radiograph. Additionally, on physical examination a poorly defined mass was noted in the upper outer quadrant of the left breast. The patient underwent bronchoscopy, excisional breast biopsy and medical thoracoscopy. By cytology, histology and immunohistochemistry primary lung adenocarcinoma with metastasis to the breast and parietal pleura was diagnosed. Both the primary and metastatic anatomic sites demonstrated histologically extensive micropapillary component, which is recently recognized as an important prognostic factor. The patient received chemotherapy but passed away within 7 months. Accurate differentiation of metastatic from primary carcinoma is of crucial importance because the treatment and prognosis differ significantly

    AGO1 and AGO2 Act Redundantly in miR408-Mediated Plantacyanin Regulation

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    Background: In Arabidopsis, AGO1 and AGO2 associate with small RNAs that exhibit a Uridine and an Adenosine at their 59 end, respectively. Because most plant miRNAs have a 59U, AGO1 plays many essential roles in miRNA-mediated regulation of development and stress responses. In contrast, AGO2 has only been implicated in antibacterial defense in association with miR393*, which has a 59A. AGO2 also participates in antiviral defense in association with viral siRNAs. Principal Findings: This study reveals that miR408, which has a 59A, regulates its target Plantacyanin through either AGO1 or AGO2. Indeed, neither ago1 nor ago2 single mutations abolish miR408-mediated regulation of Plantacyanin. Only an ago1 ago2 double mutant appears compromised in miR408-mediated regulation of Plantacyanin, suggesting that AGO1 and AGO2 have redundant roles in this regulation. Moreover, the nature of the 59 nucleotide of miR408 does not appear essential for its regulatory role because both a wildtype 59A-MIR408 and a mutant 59U-MIR408 gene complement a mir408 mutant. Conclusions/Significance: These results suggest that miR408 associates with both AGO1 and AGO2 based on criteria that differ from the 59 end rule, reminiscent of miR390-AGO7 and miR165/166-AGO10 associations, which are not based on the nature of the 59 nucleotide

    Search for astronomical neutrinos from blazar TXS 0506+056 in super-kamiokande

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    We report a search for astronomical neutrinos in the energy region from several GeV to TeV in the direction of the blazar TXS 0506+056 using the Super-Kamiokande detector following the detection of a 100 TeV neutrinos from the same location by the IceCube collaboration. Using Super-Kamiokande neutrino data across several data samples observed from 1996 April to 2018 February we have searched for both a total excess above known backgrounds across the entire period as well as localized excesses on smaller timescales in that interval. No significant excess nor significant variation in the observed event rate are found in the blazar direction. Upper limits are placed on the electron- and muon-neutrino fluxes at the 90% confidence level as 6.0 × 10−7 and 4.5 × 10−7–9.3 × 10−10 [erg cm−2 s−1], respectively
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