51 research outputs found

    Extreme genetic fragility of the HIV-1 capsid

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    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

    Impact of Anti-Inflammatory Agents on the Gene Expression Profile of Stimulated Human Neutrophils: Unraveling Endogenous Resolution Pathways

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    Adenosine, prostaglandin E2, or increased intracellular cyclic AMP concentration each elicit potent anti-inflammatory events in human neutrophils by inhibiting functions such as phagocytosis, superoxide production, adhesion and cytokine release. However, the endogenous molecular pathways mediating these actions are poorly understood. In the present study, we examined their impact on the gene expression profile of stimulated neutrophils. Purified blood neutrophils from healthy donors were stimulated with a cocktail of inflammatory agonists in the presence of at least one of the following anti-inflammatory agents: adenosine A2A receptor agonist CGS 21680, prostaglandin E2, cyclic-AMP-elevating compounds forskolin and RO 20-1724. Total RNA was analyzed using gene chips and real-time PCR. Genes encoding transcription factors, enzymes and regulatory proteins, as well as secreted cytokines/chemokines showed differential expression. We identified 15 genes for which the anti-inflammatory agents altered mRNA levels. The agents affected the expression profile in remarkably similar fashion, suggesting a central mechanism limiting cell activation. We have identified a set of genes that may be part of important resolution pathways that interfere with cell activation. Identification of these pathways will improve understanding of the capacity of tissues to terminate inflammatory responses and contribute to the development of therapeutic strategies based on endogenous resolution

    Intraneuronal Aβ immunoreactivity is not a predictor of brain amyloidosis-β or neurofibrillary degeneration

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    Amyloid β (Aβ) immunoreactivity in neurons was examined in brains of 32 control subjects, 31 people with Down syndrome, and 36 patients with sporadic Alzheimer’s disease to determine if intraneuronal Aβ immunoreactivity is an early manifestation of Alzheimer-type pathology leading to fibrillar plaque formation and/or neurofibrillary degeneration. The appearance of Aβ immunoreactivity in neurons in infants and stable neuron-type specific Aβ immunoreactivity in a majority of brain structures during late childhood, adulthood, and normal aging does not support this hypothesis. The absence or detection of only traces of reaction with antibodies against 4–13 aa and 8–17 aa of Aβ in neurons indicated that intraneuronal Aβ was mainly a product of α- and γ-secretases (Aβ(17–40/42)). The presence of N-terminally truncated Aβ(17–40) and Aβ(17–42) in the control brains was confirmed by Western blotting and the identity of Aβ(17–40) was confirmed by mass spectrometry. The prevalence of products of α- and γ -secretases in neurons and β- and γ-secretases in plaques argues against major contribution of Aβ-immunopositive material detected in neuronal soma to amyloid deposit in plaques. The strongest intraneuronal Aβ(17–42) immunoreactivity was observed in structures with low susceptibility to fibrillar Aβ deposition, neurofibrillary degeneration, and neuronal loss compared to areas more vulnerable to Alzheimer-type pathology. These observations indicate that the intraneuronal Aβ immunoreactivity detected in this study is not a predictor of brain amyloidosis or neurofibrillary degeneration. The constant level of Aβ immunoreactivity in structures free from neuronal pathology during essentially the entire life span suggests that intraneuronal amino-terminally truncated Aβ represents a product of normal neuronal metabolism

    Diabetes mellitus and the skin

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    Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Geneeskunde en GesondheidswetenskappeDermatologi

    The Prevalence and Clinical Significance of Acanthosis Nigricans in Diabetic and Non-Diabetic Women of Mixed Ancestry

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    Objectives: The purpose of this study was to improve our understanding of the prevalence of acanthosis nigricans (AN) and its clinical relevance in our mixed-ancestry population and to investigate its association with abnormal glucose metabolism, obesity and hypertension.Design: This was a cross-sectional study.Settings and subjects: A total of 390 healthy mixed-ancestry females were recruited from the dermatology outpatient clinic at Tygerberg Hospital.Outcomes measured: A short questionnaire was administered, whereafter participants were inspected for the presence and degree of AN. Height, weight, blood pressure and random fingerpick blood glucose were measured.Results: AN was observed in 30% (n = 116) of participants, and most commonly found in the nape of the neck (94%, n = 109). Participants with AN were younger (p = 0.005), and of higher body mass (p < 0.001) with a higher random blood glucose (p = 0.04). AN was more commonly seen in diabetics (p = 0.004). The presence and severity of AN in the neck correlated far better with BMI and blood glucose than other sites, including the axilla.Conclusion: AN was found to be extremely common, with a prevalence of 30% in this group. An association with blood glucose levels, diabetes and obesity was demonstrated, proving that it is not just a normal ethnic phenomenon. No association with blood pressure or hypertension was found.Keywords: Acanthosis Nigricans, Diabetes, Insulin Resistance, Mixed Ancestry, Obesit

    Toxic epidermal necrolysis and Stevens-Johnson syndrome in South Africa: a 3-year prospective study

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    Geneeskunde en GesondheidswetenskappeDermatologiePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

    Algemene Standaard Testgebruik NIP 2017

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    Het NIP vindt het belangrijk dat het werk van psychologen van goede kwaliteit is. Daarom heeft het NIP de Beroepscode voor Psychologen opgesteld en ook de vernieuwde Algemene Standaard Testgebruik AST-NIP 2017. In de Beroepscode staan de richtlijnen en gedragsregels die aan het beroepsmatig handelen van een psycholoog worden gesteld. De basisprincipes zijn dat de psycholoog zich verantwoordelijk, integer, respectvol en deskundig dient te gedragen. De AST-NIP 2017 is een uitwerking en verbijzondering van de Beroepscode en bevat richtlijnen en informatie om te komen tot een verantwoorde testkeuze en het juist gebruik van psychodiagnostische instrumenten in het kader van de psychodiagnostiek en/of psychologische interventies. De AST-NIP 2017 is een geheel herziene versie van de AST-NIP 2010

    The interactive web-based program MSmonitor for self-management and multidisciplinary care in multiple sclerosis: utilization and valuation by patients

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    Peter Joseph Jongen,1,2 Ludovicus G Sinnige,3 Björn M van Geel,4 Freek Verheul,5 Wim I Verhagen,6 Ruud A van der Kruijk,7 Reinoud Haverkamp,8 Hans M Schrijver,9 Jacoba C Baart,10 Leo H Visser,11 Edo P Arnoldus,12 Herman Jacobus Gilhuis,13 Paul Pop,14 Monique Booy,15 Marco Heerings,16 Anton Kool,17 Esther van Noort17 1Department of Community and Occupational Medicine, University Medical Center Groningen, University of Groningen, Groningen, 2MS4 Research Institute, Nijmegen, 3Multiple Sclerosis Centre Leeuwarden, Medical Centre Leeuwarden, Leeuwarden, 4Department of Neurology, Medical Centre Alkmaar, Alkmaar, 5Department of Neurology, Groene Hart Hospital, Gouda, 6Department of Neurology, Canisius Wilhelmina Hospital, Nijmegen, 7Department of Neurology, Slingeland Hospital, Doetinchem, 8Department of Neurology, Zuwe Hofpoort Hospital, Woerden, 9Multiple Sclerosis Centre, Westfries Gasthuis, Hoorn, 10Department of Neurology, Ziekenhuisgroep Twente, Almelo-Hengelo, 11Multiple Sclerosis Centre Midden Brabant, St Elisabeth Hospital, Tilburg, 12Multiple Sclerosis Centre Midden Brabant, Tweesteden Hospital, 13Department of Neurology, Reinier de Graaf Gasthuis, Delft, 14Department of Neurology, Viecuri Medical Centre, Venlo-Venray, 15Multiple Sclerosis Centre, Amphia Hospital, Breda, 16MH Advies en organisatiebureau, Assen, 17Curavista bv, Geertruidenberg, the Netherlands Background: MSmonitor is an interactive web-based program for self-management and integrated, multidisciplinary care in multiple sclerosis.Methods: To assess the utilization and valuation by persons with multiple sclerosis, we held an online survey among those who had used the program for at least 1 year. We evaluated the utilization and meaningfulness of the program’s elements, perceived use of data by neurologists and nurses, and appreciation of care, self-management, and satisfaction.Results: Fifty-five persons completed the questionnaire (estimated response rate 40%). The Multiple Sclerosis Impact Profile (MSIP), Medication and Adherence Inventory, Activities Diary, and electronic consultation (e-consult) were used by 40%, 55%, 47%, and 44% of respondents and were considered meaningful by 83%, 81%, 54%, and 88%, respectively. During out-patient consultations, nurses reportedly used the MSmonitor data three to six times more frequently than neurologists. As to nursing care, more symptoms were dealt with (according to 54% of respondents), symptoms were better discussed (69%), and the overall quality of care had improved (60%) since the use of the program. As to neurological care, these figures were 24%, 31%, and 27%, respectively. In 46% of the respondents, the insight into their symptoms and disabilities had increased since the use of the program; the MSIP, Activities Diary, and e-consult had contributed most to this improvement. The overall satisfaction with the program was 3.5 out of 5, and 73% of the respondents would recommend the program to other persons with multiple sclerosis.Conclusion: A survey among persons with multiple sclerosis using the MSmonitor program showed that the MSIP, Medication and Adherence Inventory, Activities Diary, and e-consult were frequently used and that the MSIP, Medication and Adherence Inventory, and e-consult were appreciated the most. Moreover, the quality of nursing care, but not so neurological care, had improved, which may relate to nurses making more frequent use of the MSmonitor data than neurologists. Keywords: patient-reported outcome, impact, adherence, diary, inventory, e-consul
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