446 research outputs found

    The Cayman Crab Fly Revisited — Phylogeny and Biology of Drosophila endobranchia

    Get PDF
    BACKGROUND: The majority of all known drosophilid flies feed on microbes. The wide spread of microorganisms consequently mean that drosophilids also can be found on a broad range of substrates. One of the more peculiar types of habitat is shown by three species of flies that have colonized land crabs. In spite of their intriguing lifestyle, the crab flies have remained poorly studied. Perhaps the least investigated of the three crab flies is the Cayman Island endemic Drosophila endobranchia. Apart from its life cycle very little is known about this species, including its phylogenetic position, which has remained unresolved due to a cryptic set of characteristics. PRINCIPAL FINDINGS: Based on molecular data, corroborated by a re-analysis of the morphological make up, we have resolved the phylogenetic position of D. endobranchia and show that it somewhat surprisingly belongs to the large Neotropical repleta radiation, and should be considered as an aberrant member of the canalinea species group. Furthermore we also provide additional data on the behavior of these remarkable flies. CONCLUSION: Our findings reveal that the two Caribbean crab flies are not as distantly related as first thought, as both species are members of the derived repleta radiation. That this lineage has given rise to two species with the same odd type of breeding substrate is curious and prompts the question of what aspects of their shared ancestry has made these flies suitable for a life on (and inside) land crabs. Knowledge of the phylogenetic position of D. endobranchia will allow for comparative explorations and will aid in efforts aimed at understanding processes involved in drastic host shifts and extreme specialization

    Regulation of Progranulin Expression in Human Microglia and Proteolysis of Progranulin by Matrix Metalloproteinase-12 (MMP-12)

    Get PDF
    Background: The essential role of progranulin (PGRN) as a neurotrophic factor has been demonstrated by the discovery that haploinsufficiency due to GRN gene mutations causes frontotemporal lobar dementia. In addition to neurons, microglia in vivo express PGRN, but little is known about the regulation of PGRN expression by microglia. Goal: In the current study, we examined the regulation of expression and function of PGRN, its proteolytic enzyme macrophage elastase (MMP-12), as well as the inhibitor of PGRN proteolysis, secretory leukocyte protease inhibitor (SLPI), in human CNS cells. Methods: Cultures of primary human microglia and astrocytes were stimulated with the TLR ligands (LPS or poly IC), Th1 cytokines (IL-1/IFNc), or Th2 cytokines (IL-4, IL-13). Results were analyzed by Q-PCR, immunoblotting or ELISA. The roles of MMP-12 and SLPI in PGRN cleavage were also examined. Results: Unstimulated microglia produced nanogram levels of PGRN, and PGRN release from microglia was suppressed by the TLR ligands or IL-1/IFNc, but increased by IL-4 or IL-13. Unexpectedly, while astrocytes stimulated with proinflammatory factors released large amounts of SLPI, none were detected in microglial cultures. We also identified MMP-12 as a PGRN proteolytic enzyme, and SLPI as an inhibitor of MMP-12-induced PGRN proteolysis. Experiments employing PGRN siRNA demonstrated that microglial PGRN was involved in the cytokine and chemokine production following TLR3/4 activation

    Rosiglitazone synergizes anticancer activity of cisplatin and reduces its nephrotoxicity in 7, 12-dimethyl benz{a}anthracene (DMBA) induced breast cancer rats

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Antineoplastic drug cisplatin remains the drug of choice for various solid tumours including breast cancer. But dose dependent nephrotoxicity is the major drawback in majority of platinum based chemotherapy regimens. Recent reports have shown that inflammatory pathways are the main offender for cisplatin induced nephrotoxicity. The present study was undertaken to assess the effect of rosiglitazone, a PPARγ agonist and an anti-inflammatory agent, on cisplatin induced nephrotoxicity, and its anticancer activity in DMBA induced breast cancer rats.</p> <p>Methods</p> <p>Mammary tumours were induced in female Sprague-Dawley rats by feeding orally with dimethylbenz [a]anthracene (DMBA) (60 mg/kg). Cisplatin induced nephropathy was assessed by measurements of blood urea nitrogen, albumin and creatinine levels. Posttranslational modifications of histone H3, mitogen-activated protein (MAP) kinase p38 expression and PPAR-γ expression were examined by western blotting.</p> <p>Results</p> <p>Our data shows involvement of TNF-α in preventing cisplatin induced nephrotoxicity by rosiglitazone. Rosiglitazone pre-treatment to cisplatin increases the expression of p38, PPAR-γ in mammary tumours and shows maximum tumour reduction. Furthermore, cisplatin induced changes in histone acetylation, phosphorylation and methylation of histone H3 in mammary tumours was ameliorated by pre-treatment of rosiglitazone. Suggesting, PPAR-γ directly or indirectly alters aberrant gene expression in mammary tumours by changing histone modifications.</p> <p>Conclusion</p> <p>To best of our knowledge this is the first report which shows that pre-treatment of rosiglitazone synergizes the anticancer activity of cisplatin and minimizes cisplatin induced nephrotoxicity in DMBA induced breast cancer.</p

    Life experiences throughout the ifespan: What do people say (or not) about them?

    Get PDF
    Life experiences have been a topic of interest for researchers and clinicians for decades. Current knowledge is rooted in two distinct approaches, i.e., personality psychology and psychosomatics. Whereas the first is interested in ordinary life stories of nonclinical individuals, based on a more qualitative, in-depth, and person-driven approach, psychosomatics stresses negative events, mainly in clinical samples, and presents a more quantitative, general, and construct-driven approach. Consequently, available evidence is dispersed and unrelated and many basic questions remain unanswered. This study aimed to explore occurrence, developmental stage, valence, and impact of life experiences and to analyze critical answering patterns (i.e., “I don’t remember,” missingness). Through a cross-sectional retrospective design, 394 adults from the community answered the Lifetime Experiences Scale, which covers 75 life experiences organized in eight domains (i.e., school, job, health, leisure, living conditions, adverse experiences, achievements, and people and relationships). Occurrence of life experiences varied greatly, and the mean number of experiences reported was approximately 30. Regarding developmental stage, most experiences were reported in just one stage—mainly adulthood—however, some could be considered chronic. Globally, life experiences tended to be clearly rated as positive or as negative; additionally, assessed experiences were mainly appraised as positive. Moreover, participants presented their experiences as significant, rating them as high impact. Overall, critical answering patterns were not very expressive: “I don’t remember” and missing answers were below 2 and 5%, respectively, in the majority of experiences. These findings offer several important new insights, suggesting that life experiences are mainly an idiosyncratic topic.This manuscript is part of a doctoral dissertation, which had the support of the Portuguese Foundation for Science and Technology (FCT), through the PhD grant with the reference SFRH/ BD/76022/2011, funded by POPH-QREN-Typology 4.1-Advanced Training, reimbursed by the European Social Fund and national funds from State Budget. This study was conducted at Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Education and Science through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653).info:eu-repo/semantics/publishedVersio

    The Taiwan Birth Panel Study: a prospective cohort study for environmentally- related child health

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The Taiwan Birth Panel Study (TBPS) is a prospective follow-up study to investigate the development of child health and disease in relation to in-utero and/or early childhood environmental exposures. The rationale behind the establishment of such a cohort includes the magnitude of potential environmental exposures, the timing of exposure window, fatal and children's susceptibility to toxicants, early exposure delayed effects, and low-level or unknown neurodevelopmental toxicants.</p> <p>Methods</p> <p>A total of 486 mother-infant paired was enrolled from April 2004 to January 2005 in this study. Maternal blood before delivery, placenta and umbilical cord blood at birth, and mothers' urine after delivery were collected. The follow-up was scheduled at birth, 4, 6 months, and 1, 2, 3 and 5 years. The children's blood, urine, hair, and saliva were collected at 2 years of age and children's urine was collected at 5 years of age as well. The study has been approved by the ethical committee of National Taiwan University Hospital. All the subjects signed the inform consent on entering the study and each of the follow up.</p> <p>Results</p> <p>Through this prospective birth cohort, the main health outcomes were focused on child growth, neurodevelopment, behaviour problem and atopic diseases. We investigated the main prenatal and postnatal factors including smoking, heavy metals, perfluorinated chemicals, and non-persistent pesticides under the consideration of interaction of the environment and genes.</p> <p>Conclusions</p> <p>This cohort study bridges knowledge gaps and answers unsolved issues in the low-level, prenatal or postnatal, and multiple exposures, genetic effect modification, and the initiation and progression of "environmentally-related childhood diseases."</p

    Quantification of fractional flow reserve based on angiographic image data

    Get PDF
    Coronary angiography provides excellent visualization of coronary arteries, but has limitations in assessing the clinical significance of a coronary stenosis. Fractional flow reserve (FFR) has been shown to be reliable in discerning stenoses responsible for inducible ischemia. The purpose of this study is to validate a technique for FFR quantification using angiographic image data. The study was carried out on 10 anesthetized, closed-chest swine using angioplasty balloon catheters to produce partial occlusion. Angiography based FFR was calculated from an angiographically measured ratio of coronary blood flow to arterial lumen volume. Pressure-based FFR was measured from a ratio of distal coronary pressure to aortic pressure. Pressure-wire measurements of FFR (FFRP) correlated linearly with angiographic volume-derived measurements of FFR (FFRV) according to the equation: FFRP = 0.41 FFRV + 0.52 (P-value < 0.001). The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively. This is the first study to provide an angiographic method to quantify FFR in swine. Angiographic FFR can potentially provide an assessment of the physiological severity of a coronary stenosis during routine diagnostic cardiac catheterization without a need to cross a stenosis with a pressure-wire

    A framework for the first‑person internal sensation of visual perception in mammals and a comparable circuitry for olfactory perception in Drosophila

    Get PDF
    Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic operation of perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure-function details of the presented mechanism of perception

    Optogenetic control of Drosophila using a red-shifted channelrhodopsin reveals experience-dependent influences on courtship

    Get PDF
    Optogenetics allows the manipulation of neural activity in freely moving animals with millisecond precision, but its application in Drosophila melanogaster has been limited. Here we show that a recently described red activatable channelrhodopsin (ReaChR) permits control of complex behavior in freely moving adult flies, at wavelengths that are not thought to interfere with normal visual function. This tool affords the opportunity to control neural activity over a broad dynamic range of stimulation intensities. Using time-resolved activation, we show that the neural control of male courtship song can be separated into (i) probabilistic, persistent and (ii) deterministic, command-like components. The former, but not the latter, neurons are subject to functional modulation by social experience, which supports the idea that they constitute a locus of state-dependent influence. This separation is not evident using thermogenetic tools, a result underscoring the importance of temporally precise control of neuronal activation in the functional dissection of neural circuits in Drosophila
    corecore