17 research outputs found

    The Functions of Grainy Head-Like Proteins in Animals and Fungi and the Evolution of Apical Extracellular Barriers

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    The Grainy head (GRH) family of transcription factors are crucial for the development and repair of epidermal barriers in all animals in which they have been studied. This is a high-level functional conservation, as the known structural and enzymatic genes regulated by GRH proteins differ between species depending on the type of epidermal barrier being formed. Interestingly, members of the CP2 superfamily of transcription factors, which encompasses the GRH and LSF families in animals, are also found in fungi – organisms that lack epidermal tissues. To shed light on CP2 protein function in fungi, we characterized a Neurospora crassa mutant lacking the CP2 member we refer to as grainy head-like (grhl). We show that Neurospora GRHL has a DNA-binding specificity similar to that of animal GRH proteins and dissimilar to that of animal LSF proteins. Neurospora grhl mutants are defective in conidial-spore dispersal due to an inability to remodel the cell wall, and we show that grhl mutants and the long-known conidial separation-2 (csp-2) mutants are allelic. We then characterized the transcriptomes of both Neurospora grhl mutants and Drosophila grh mutant embryos to look for similarities in the affected genes. Neurospora grhl appears to play a role in the development and remodeling of the cell wall, as well as in the activation of genes involved in defense and virulence. Drosophila GRH is required to activate the expression of many genes involved in cuticular/epidermal-barrier formation. We also present evidence that GRH plays a role in adult antimicrobial defense. These results, along with previous studies of animal GRH proteins, suggest the fascinating possibility that the apical extracellular barriers of some animals and fungi might share an evolutionary connection, and that the formation of physical barriers in the last common ancestor was under the control of a transcriptional code that included GRH-like proteins

    Towards better lighting recommendations for open surgery

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    This study assesses the lighting requirements for operating theatres and the lighting conditions in a specific test case and proposes alternate ways of achieving a favourable visual environment. The hypothesis was that an increased illuminance level from general lighting and lower luminance contrasts between the essential task areas affect perceived lighting quality, visual ability and performance, as well as tiredness of medical staff performing surgical work. The investigation consisted of three parts: a laboratory study, followed by a field study and concluding with a retrospective study. In the laboratory study, each medical staff subject was exposed to four lighting scenarios with three illuminances from the operating light (12 lighting conditions), with no patients present. In the field and the retrospective study, the existing lighting scenario was compared to the highest-rated test lighting scenario (with illuminances more than double). The field study and the retrospective study took place with medical staff working under either the test general lighting condition or the existing general lighting condition. Increased illuminance from the general lighting and a higher correlated colour temperature did not improve the operating staff’s visual ability. However, medical staff rated the change in lighting quality resulting from the increased general illuminance as an improvement in the work environment, both in the laboratory study and in the field study. Medical staff subjects using the operating theatre rated both perceived visual ability and lighting quality higher under the test lighting scenario. Tiredness was also rated lower under that test scenario. Based on the results from this study, general lighting levels of 2000 lx in the periphery of the operating room, 4000 lx surrounding the operating table and 5500 lx on the operating table are recommended by the authors. With reference to the selections made by the surgeons for the illuminance in the operating cavity, it is suggested that the central beam illuminance from the surgical luminaires be between 50,000 lx and 100,000 lx

    Opting to wear prismatic spectacles was associated with reduced neck pain in dental personnel : A longitudinal cohort study

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    Background: The aim of this study was to investigate effects on perceived exertion, work ability self-reported neck pain and clinically diagnosed conditions in the neck, of an intervention with prismatic spectacles among dental personnel. Methods: In this cohort study a baseline questionnaire including questions about frequency of neck pain, perceived exertion during work and background information was distributed to dental personnel in municipal dental care units. In connection, personnel from 78 out of 110 dental care units underwent a clinical neck examination and rated their perceived work ability with the single-item question from the Work Ability Index. The study population consisted of 564 participants; 366 in the questionnaire group, 321 in the examination group, whereof 123 participated in both assessments. In total 371 belonged to the intervention group and received individually adjusted prismatic spectacles after the baseline assessments (inclusion based on self-selection) and 193 belonged to the reference group. At the 12-month follow-up the clinical examination was repeated and the same questionnaire with additional questions was completed. Fisher's exact test or the Mann-Whitney U test was used to assess differences between the intervention group and the reference group at baseline. Differences at follow up between the two groups were assessed by means of Linear-by Linear association test for trends. Results: A significant decrease in neck pain (p = 0.047), clinical diagnoses in the neck (p = 0.025), and perceived exertion (p = 0.003) was observed at follow up for the intervention group compared to the reference group. Moreover, for the intervention group a significantly improved self-rated work ability (p = 0.040) was reported. Finally, opting to wear prismatic spectacles during dental work appeared to have a preventive effect on neck pain. Conclusions: Dental personnel opting to wear prismatic spectacles reduced their neck pain significantly more at follow up compared with the reference group. These results are worthwhile testing in a randomised design. The practical implication of this study is that recommendations regarding ergonomics for dental professionals may include the use of prismatic glasses, both as primary and secondary prevention of work-related neck pain. Such glasses should also be tested in other working situations where the work tasks include high visual demands in sustained awkward neck postures
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