56 research outputs found

    Cloning, expression and nuclear localization of human NPM3, a member of the nucleophosmin/nucleoplasmin family of nuclear chaperones

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    BACKGROUND: Studies suggest that the related proteins nucleoplasmin and nucleophosmin (also called B23, NO38 or numatrin) are nuclear chaperones that mediate the assembly of nucleosomes and ribosomes, respectively, and that these activities are accomplished through the binding of basic proteins via their acidic domains. Recently discovered and less well characterized members of this family of acidic phosphoproteins include mouse nucleophosmin/nucleoplasmin 3 (Npm3) and Xenopus NO29. Here we report the cloning and initial characterization of the human ortholog of Npm3. RESULTS: Human genomic and cDNA clones of NPM3 were isolated and sequenced. NPM3 lies 5.5 kb upstream of FGF8 and thus maps to chromosome 10q24-26. In addition to amino acid similarities, NPM3 shares many physical characteristics with the nucleophosmin/nucleoplasmin family, including an acidic domain, multiple potential phosphorylation sites and a putative nuclear localization signal. Comparative analyses of 14 members of this family from various metazoans suggest that Xenopus NO29 is a candidate ortholog of human and mouse NPM3, and they further group both proteins closer with the nucleoplasmins than with the nucleophosmins. Northern blot analysis revealed that NPM3 was strongly expressed in all 16 human tissues examined, with especially robust expression in pancreas and testis; lung displayed the lowest level of expression. An analysis of subcellular fractions of NIH3T3 cells expressing epitope-tagged NPM3 revealed that NPM3 protein was localized solely in the nucleus. CONCLUSIONS: Human NPM3 is an abundant and widely expressed protein with primarily nuclear localization. These biological activities, together with its physical relationship to the chaparones nucleoplasmin and nucleophosmin, are consistent with the proposed function of NPM3 as a molecular chaperone functioning in the nucleus

    Distinct Functional Roles of β-Tubulin Isotypes in Microtubule Arrays of Tetrahymena thermophila, a Model Single-Celled Organism

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    <div><h3>Background</h3><p>The multi-tubulin hypothesis proposes that each tubulin isotype performs a unique role, or subset of roles, in the universe of microtubule function(s). To test this hypothesis, we are investigating the functions of the recently discovered, noncanonical β-like tubulins (BLTs) of the ciliate, <em>Tetrahymena thermophila</em>. <em>Tetrahymena</em> forms 17 distinct microtubular structures whose assembly had been thought to be based on single α- and β-isotypes. However, completion of the macronuclear genome sequence of <em>Tetrahymena</em> demonstrated that this ciliate possessed a β-tubulin multigene family: two synonymous genes (<em>BTU1</em> and <em>BTU2</em>) encode the canonical β-tubulin, BTU2, and six genes (<em>BLT1-6</em>) yield five divergent β-tubulin isotypes. In this report, we examine the structural features and functions of two of the BLTs (BLT1 and BLT4) and compare them to those of BTU2.</p> <h3>Methodology/Principal Findings</h3><p>With respect to BTU2, BLT1 and BLT4 had multiple sequence substitutions in their GTP-binding sites, in their interaction surfaces, and in their microtubule-targeting motifs, which together suggest that they have specialized functions. To assess the roles of these tubulins <em>in vivo</em>, we transformed <em>Tetrahymena</em> with expression vectors that direct the synthesis of GFP-tagged versions of the isotypes. We show that GFP-BLT1 and GFP-BLT4 were not detectable in somatic cilia and basal bodies, whereas GFP-BTU2 strongly labeled these structures. During cell division, GFP-BLT1 and GFP-BLT4, but not GFP-BTU2, were incorporated into the microtubule arrays of the macronucleus and into the mitotic apparatus of the micronucleus. GFP-BLT1 also participated in formation of the microtubules of the meiotic apparatus of the micronucleus during conjugation. Partitioning of the isotypes between nuclear and ciliary microtubules was confirmed biochemically.</p> <h3>Conclusion/Significance</h3><p>We conclude that <em>Tetrahymena</em> uses a family of distinct β-tubulin isotypes to construct subsets of functionally different microtubules, a result that provides strong support for the multi-tubulin hypothesis.</p> </div

    Patients' experiences of living with and receiving treatment for fibromyalgia syndrome: a qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Fibromyalgia syndrome (FMS) presents a challenge for patients and health care staff across many medical specialities. The aetiology is multi-dimensional, involving somatic, psychological and social factors. Patients' views were obtained to understand their experience of living with this long-term condition, using qualitative interviews.</p> <p>Methods</p> <p>12 patients were recruited and stratified by age, gender and ethnicity from one rheumatology outpatient clinic, and a departmental held database of patients diagnosed with FMS.</p> <p>Results</p> <p>Patients' accounts of their experience of FMS resonated well with two central concepts: social identity and illness intrusiveness. These suggested three themes for the analytical framework: life before and after diagnosis (e.g. lack of information about FMS, invisibility of FMS); change in health identity (e.g. mental distress, impact on social life) and perceived quality of care (e.g. lack of contact with nurses, attitudes of specialists). The information provided from one male participant did not differ from the female patients, but black and ethnic community patients expressed a degree of suspicion towards the medication prescribed, and the attitudes displayed by some doctors, a finding that has not been previously reported amongst this patient group. Patients expected more consultation time and effective treatment than they received. Subjective experiences and objective physical and emotional changes were non-overlapping. Patients' accounts revealed that their physical, mental and social health was compromised, at times overwhelming and affected their identity.</p> <p>Conclusion</p> <p>FMS is a condition that intrudes upon many aspects of patients' lives and is little understood. At the same time, it is a syndrome that evokes uneasiness in health care staff (as current diagnostic criteria are not well supported by objective markers of physiological or biochemical nature, and indeed because of doubt about the existence of the condition) and places great demands on resources in clinical practice. Greater attention needs to be paid to the links between the explanatory models of patients and staff, and most important, to the interrelationship between the complex physical, psychological and social needs of patients with FMS. Taking a less medical but more holistic approach when drawing up new diagnostic criteria for FMS might match better individuals' somatic and psycho-social symptom profile and may result in more effective treatment.</p

    Mental and substance use disorders from early adolescence to young adulthood among indigenous young people: Final diagnostic results from an 8-year panel study

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    Objective: Our objective was to investigate change in prevalence rates for mental and substance abuse disorders between early adolescence and young adulthood in a cohort of indigenous adolescents who participated in an 8-year panel study.Method: The data are from a lagged, sequential study of 671 indigenous adolescents (Wave 1) from a single culture in the Northern Midwest USA and Canada. At Wave 1 (mean age 11.3 years, Wave 4 (mean age 14.3 years), Wave 6 (mean age 16.2 years), and at Wave 8 (mean age 18.3 years) the tribally enrolled adolescents completed a computer-assisted personal interview that included DISC-R assessment for 11 diagnoses. Our yearly retention rates by diagnostic wave were: Wave 2, 94.7 %; Wave 4, 87.7 %; Wave 6, 88.0 %; Wave 8, 78.5 %.Results: The findings show a dramatic increase in lifetime prevalence rates for substance use disorders. By young adulthood, over half had met criteria of substance abuse or dependence disorder. Also at young adulthood, 58.2 % had met lifetime criteria of a single substance use or mental disorder and 37.2 % for two or more substance use or mental disorders. The results are compared to other indigenous diagnostic studies and to the general population.Conclusions: A mental health crisis exists within the indigenous populations that participated in this study. Innovations within current mental health service systems are needed to address the unmet demand of adolescents and families.Peer reviewedSociolog

    "People like numbers": a descriptive study of cognitive assessment methods in clinical practice for Aboriginal Australians in the Northern Territory

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    Achieving culturally fair assessments of cognitive functioning for Aboriginal people is difficult due to a scarcity of appropriately validated tools for use with this group. As a result, some Aboriginal people with cognitive impairments may lack fair and equitable access to services. The objective of this study was to examine current clinical practice in the Northern Territory regarding cognitive assessment for Aboriginal people thereby providing some guidance for clinicians new to this practice setting. Conclusions Cognitive tests developed specifically for Aboriginal people are urgently needed. In the absence of appropriate, validated tests, clinicians have relied on and modified a range of standardised and informal assessments, whilst recognising the severe limitations of these. Past clinical training has not prepared clinicians adequately for assessing Aboriginal clients, and experience and clinical judgment were considered crucial for fair interpretation of test scores. Interpretation guidelines may assist inexperienced clinicians to consider whether they are achieving fair assessments of cognition for Aboriginal clients.This paper was supported by a Training Fellowship for Indigenous Australian Health Research from the National Health and Medical Research Council of Australia
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