230 research outputs found

    Canine respiratory coronavirus employs caveolin-1-mediated pathway for internalization to HRT-18G cells

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    Canine respiratory coronavirus (CRCoV), identified in 2003, is a member of the Coronaviridae family. The virus is a betacoronavirus and a close relative of human coronavirus OC43 and bovine coronavirus. Here, we examined entry of CRCoV into human rectal tumor cells (HRT-18G cell line) by analyzing co-localization of single virus particles with cellular markers in the presence or absence of chemical inhibitors of pathways potentially involved in virus entry. We also targeted these pathways using siRNA. The results show that the virus hijacks caveolin-dependent endocytosis to enter cells via endocytic internalization

    Genetic and environmental effects on body mass index from infancy to the onset of adulthood: an individual-based pooled analysis of 45 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) study

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    Background: Both genetic and environmental factors are known to affect body mass index (BMI), but detailed understanding of how their effects differ during childhood and adolescence is lacking. Objectives: We analyzed the genetic and environmental contributions to BMI variation from infancy to early adulthood and the ways they differ by sex and geographic regions representing high (North America and Australia), moderate (Europe), and low levels (East Asia) of obesogenic environments. Design: Data were available for 87,782 complete twin pairs from 0.5 to 19.5 y of age from 45 cohorts. Analyses were based on 383,092 BMI measurements. Variation in BMI was decomposed into genetic and environmental components through genetic structural equation modeling. Results: The variance of BMI increased from 5 y of age along with increasing mean BMI. The proportion of BMI variation explained by additive genetic factors was lowest at 4 y of age in boys (a2 = 0.42) and girls (a2 = 0.41) and then generally increased to 0.75 in both sexes at 19 y of age. This was because of a stronger influence of environmental factors shared by co-twins in midchildhood. After 15 y of age, the effect of shared environment was not observed. The sex-specific expression of genetic factors was seen in infancy but was most prominent at 13 y of age and older. The variance of BMI was highest in North America and Australia and lowest in East Asia, but the relative proportion of genetic variation to total variation remained roughly similar across different regions. Conclusions: Environmental factors shared by co-twins affect BMI in childhood, but little evidence for their contribution was found in late adolescence. Our results suggest that genetic factors play a major role in the variation of BMI in adolescence among populations of different ethnicities exposed to different environmental factors related to obesity

    Current opinion on the role of testosterone in the development of prostate cancer: a dynamic model

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    Background: Since the landmark study conducted by Huggins and Hodges in 1941, a failure to distinguish between the role of testosterone in prostate cancer development and progression has led to the prevailing opinion that high levels of testosterone increase the risk of prostate cancer. To date, this claim remains unproven. Presentation of the Hypothesis: We present a novel dynamic mode of the relationship between testosterone and prostate cancer by hypothesizing that the magnitude of age-related declines in testosterone, rather than a static level of testosterone measured at a single point, may trigger and promote the development of prostate cancer. Testing of the Hypothesis: Although not easily testable currently, prospective cohort studies with population-representative samples and repeated measurements of testosterone or retrospective cohorts with stored blood samples from different ages are warranted in future to test the hypothesis. Implications of the Hypothesis: Our dynamic model can satisfactorily explain the observed age patterns of prostate cancer incidence, the apparent conflicts in epidemiological findings on testosterone and risk of prostate cancer, racial disparities in prostate cancer incidence, risk factors associated with prostate cancer, and the role of testosterone in prostate cancer progression. Our dynamic model may also have implications for testosterone replacement therapy

    Is it reliable to assess visual attention of drivers affected by Parkinson's disease from the backseat?—a simulator study

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    BACKGROUND: Current methods of determining licence retainment or cancellation is through on-road driving tests. Previous research has shown that occupational therapists frequently assess drivers' visual attention while sitting in the back seat on the opposite side of the driver. Since the eyes of the driver are not always visible, assessment by eye contact becomes problematic. Such procedural drawbacks may challenge validity and reliability of the visual attention assessments. In terms of correctly classified attention, the aim of the study was to establish the accuracy and the inter-rater reliability of driving assessments of visual attention from the back seat. Furthermore, by establishing eye contact between the assessor and the driver through an additional mirror on the wind screen, the present study aimed to establish how much such an intervention would enhance the accuracy of the visual attention assessment. METHODS: Two drivers with Parkinson's disease (PD) and six control drivers drove a fixed route in a driving simulator while wearing a head mounted eye tracker. The eye tracker data showed where the foveal visual attention actually was directed. These data were time stamped and compared with the simultaneous manual scoring of the visual attention of the drivers. In four of the drivers, one with Parkinson's disease, a mirror on the windscreen was set up to arrange for eye contact between the driver and the assessor. Inter-rater reliability was performed with one of the Parkinson drivers driving, but without the mirror. RESULTS: Without mirror, the overall accuracy was 56% when assessing the three control drivers and with mirror 83%. However, for the PD driver without mirror the accuracy was 94%, whereas for the PD driver with a mirror the accuracy was 90%. With respect to the inter-rater reliability, a 73% agreement was found. CONCLUSION: If the final outcome of a driving assessment is dependent on the subcategory of a protocol assessing visual attention, we suggest the use of an additional mirror to establish eye contact between the assessor and the driver. The clinicians' observations on-road should not be a standalone assessment in driving assessments. Instead, eye trackers should be employed for further analyses and correlation in cases where there is doubt about a driver's attention

    Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020

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    This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595–828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.</p

    A new mouse model for renal lesions produced by intravenous injection of diphtheria toxin A-chain expression plasmid

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    BACKGROUND: Various animal models of renal failure have been produced and used to investigate mechanisms underlying renal disease and develop therapeutic drugs. Most methods available to produce such models appear to involve subtotal nephrectomy or intravenous administration of antibodies raised against basement membrane of glomeruli. In this study, we developed a novel method to produce mouse models of renal failure by intravenous injection of a plasmid carrying a toxic gene such as diphtheria toxin A-chain (DT-A) gene. DT-A is known to kill cells by inhibiting protein synthesis. METHODS: An expression plasmid carrying the cytomegalovirus enhancer/chicken β-actin promoter linked to a DT-A gene was mixed with lipid (FuGENE™6) and the resulting complexes were intravenously injected into adult male B6C3F1 mice every day for up to 6 days. After final injection, the kidneys of these mice were sampled on day 4 and weeks 3 and 5. RESULTS: H-E staining of the kidney specimens sampled on day 4 revealed remarkable alterations in glomerular compartments, as exemplified by mesangial cell proliferation and formation of extensive deposits in glomerular basement membrane. At weeks 3 and 5, gradual recovery of these tissues was observed. These mice exhibited proteinuria and disease resembling sub-acute glomerulonephritis. CONCLUSIONS: Repeated intravenous injections of DT-A expression plasmid DNA/lipid complex caused temporary abnormalities mainly in glomeruli of mouse kidney. The disease in these mice resembles sub-acute glomerulonephritis. These DT-A gene-incorporated mice will be useful as animal models in the fields of nephrology and regenerative medicine

    MAO-inhibitors in Parkinson's Disease

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    Monoamine oxidase inhibitors (MAO-I) belong to the earliest drugs tried in Parkinson's disease (PD). They have been used with or without levodopa (L-DOPA). Non-selective MAO-I due to their side-effect/adverse reaction profile, like tranylcypromine have limited use in the treatment of depression in PD, while selective, reversible MAO-A inhibitors are recommended due to their easier clinical handling. For the treatment of akinesia and motor fluctuations selective irreversible MAO-B inhibitors selegiline and rasagiline are recommended. They are safe and well tolerated at the recommended daily doses. Their main differences are related to (1) metabolism, (2) interaction with CYP-enzymes and (3) quantitative properties at the molecular biological/genetic level. Rasagiline is more potent in clinical practise and has a hypothesis driven more favourable side effect/adverse reaction profile due to its metabolism to aminoindan. Both selegiline and rasagiline have a neuroprotective and neurorestaurative potential. A head-to head clinical trial would be of utmost interest from both the clinical outcome and a hypothesis-driven point of view. Selegiline is available as tablet and melting tablet for PD and as transdermal selegiline for depression, while rasagiline is marketed as tablet for PD. In general, the clinical use of MAO-I nowadays is underestimated. There should be more efforts to evaluate their clinical potency as antidepressants and antidementive drugs in addition to the final proof of their disease-modifying potential. In line with this are recent innovative developments of MAO-I plus inhibition of acetylcholine esterase for Alzheimer's disease as well as combined MAO-I and iron chelation for PD

    Dopaminergic Polymorphisms Associated with Time-on-Task Declines and Fatigue in the Psychomotor Vigilance Test

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    Prolonged demands on the attention system can cause a decay in performance over time known as the time-on-task effect. The inter-subject differences in the rate of this decline are large, and recent efforts have been made to understand the biological bases of these individual differences. In this study, we investigate the genetic correlates of the time-on-task effect, as well as its accompanying changes in subjective fatigue and mood. N = 332 subjects performed a 20-minute test of sustained attention (the Psychomotor Vigilance Test) and rated their subjective states before and after the test. We observed substantial time-on-task effects on average, and large inter-individual differences in the rate of these declines. The 10-repeat allele of the variable number of tandem repeats marker (VNTR) in the dopamine transporter gene and the Met allele of the catechol-o-methyl transferase (COMT) Val158Met polymorphism were associated with greater vulnerability to time-on-task. Separately, the exon III DRD4 48 bp VNTR of the dopamine receptor gene DRD4 was associated with subjective decreases in energy. No polymorphisms were associated with task-induced changes in mood. We posit that the dopamine transporter and COMT genes exert their effects by increasing dopaminergic tone, which may induce long-term changes in the prefrontal cortex, an important mediator of sustained attention. Thus, these alleles may affect performance particularly when sustained dopamine release is necessary

    Cushing's Syndrome and Fetal Features Resurgence in Adrenal Cortex–Specific Prkar1a Knockout Mice

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    Carney complex (CNC) is an inherited neoplasia syndrome with endocrine overactivity. Its most frequent endocrine manifestation is primary pigmented nodular adrenocortical disease (PPNAD), a bilateral adrenocortical hyperplasia causing pituitary-independent Cushing's syndrome. Inactivating mutations in PRKAR1A, a gene encoding the type 1 α-regulatory subunit (R1α) of the cAMP–dependent protein kinase (PKA) have been found in 80% of CNC patients with Cushing's syndrome. To demonstrate the implication of R1α loss in the initiation and development of PPNAD, we generated mice lacking Prkar1a specifically in the adrenal cortex (AdKO). AdKO mice develop pituitary-independent Cushing's syndrome with increased PKA activity. This leads to autonomous steroidogenic genes expression and deregulated adreno-cortical cells differentiation, increased proliferation and resistance to apoptosis. Unexpectedly, R1α loss results in improper maintenance and centrifugal expansion of cortisol-producing fetal adrenocortical cells with concomitant regression of adult cortex. Our data provide the first in vivo evidence that loss of R1α is sufficient to induce autonomous adrenal hyper-activity and bilateral hyperplasia, both observed in human PPNAD. Furthermore, this model demonstrates that deregulated PKA activity favors the emergence of a new cell population potentially arising from the fetal adrenal, giving new insight into the mechanisms leading to PPNAD
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