15 research outputs found
Low resolution vision in a velvet worm (Onychophora)
Onychophorans, also known as velvet worms, possess a pair of simple lateral eyes, and are a key lineage with regard to the evolution of vision. They resemble ancient Cambrian forms, and are closely related to arthropods, which boast an unrivalled diversity of eye designs. Nonetheless, the visual capabilities of onychophorans have not been well explored. Here, we assess the spatial resolution of the onychophoran using behavioural experiments, three-dimensional reconstruction, anatomical and optical examinations, and modelling. Exploiting a spontaneous attraction towards dark objects, we find that can resolve stimuli that have the same average luminance as the background. Depending on the assumed contrast sensitivity of the animals, we estimate spatial resolution to be in the range of 15° to 40°. This results from an arrangement where the cornea and lens project the image largely behind the retina. The peculiar ellipsoid shape of the eye in combination with the asymmetric position and tilted orientation of the lens may improve spatial resolution in the forward direction. Nonetheless, the unordered network of interdigitating photoreceptors, which fills the whole eye chamber, precludes high acuity vision. Our findings suggest that adult specimens of cannot spot or visually identify prey or conspecifics beyond a few centimetres from the eye, but the coarse spatial resolution that the animals exhibited in our experiments is likely sufficient to find shelter and suitable microhabitats from further away. To our knowledge, this is the first evidence of resolving vision in an onychophoran
Sequestosome‐1 (p62) expression reveals chaperone‐assisted selective autophagy in immune‐mediated necrotizing myopathies
Diffuse myofiber necrosis in the context of inflammatory myopathy is the hallmark of immune-mediated necrotizing myopathy (IMNM). We have previously shown that skeletal muscle fibers of IMNM patients may display nonrimmed vacuoles and sarcoplasmic irregularities. The dysfunctional chaperone activity has been linked to the defective assembly of skeletal muscle proteins and their degradation via lysosomes, autophagy and the proteasomal machinery. This study was undertaken to highlight a chaperone-assisted selective autophagy (CASA) pathway, functionally involved in protein homeostasis, cell stress and the immune response in skeletal muscle of IMNM patients. Skeletal muscle biopsies from 54 IMNM patients were analyzed by immunostaining, as well as by qPCR. Eight biopsies of sIBM patients served as pathological controls, and eight biopsies of nondisease control subjects were included. Alteration of autophagy was detectable in all IMNM biopsy samples highlighted via a diffuse sarcoplasmic staining pattern by p62 and LC3 independent of vacuoles. This pattern was at variance with the coarse focal staining pattern mostly confined to rimmed vacuoles in sIBM. Colocalization of p62 with the chaperone proteins HSP70 and alpha B-crystalline points to the specific targeting of misfolded proteins to the CASA machinery. Bcl2-associated athanogene 3 (BAG3) positivity of these fibers emphasizes the selectivity of autophagy processes and these fibers also express MHC class I sarcolemma. Expression of genes involved in autophagy and endoplasmic reticulum (ER) stress pathways studied here is significantly upregulated in IMNM. We highlight that vacuoles without sarcolemmal features may arise in IMNM muscle biopsies, and they must not be confounded with sIBM-specific vacuoles. Further, we show the activation of selective autophagy and emphasize the role of chaperones in this context. CASA occurs in IMNM muscle, and specific molecular pathways of autophagy differ from the ones in sIBM, with p62 as a unique identifier of this process
Correction: Low-resolution vision in a velvet worm (Onychophora) (Polymers and Polymer Composites (2018) 221(jeb175802) DOI: 10.1242/jeb.175802)
In Materials and Methods, ‘Object taxis’, the final sentence should read: ‘An animal contributed only one trial to each experiment except for the two smaller bar targets, for which individuals were assessed up to four times.’ In addition, there were typing errors in the ‘Individual’ column (rows 89, 90 and 91) and ‘Target arc angle’ column (row 248) in Table S2; these values have been corrected. None of the changes affects the conclusions of the paper. The authors apologise for any inconvenience this may have caused
Validation of an established prognostic score after re-irradiation of recurrent glioma
<p><b>Background:</b> Re-irradiation (Re-RT) is offered widely in clinical routine, and has been established as a key element in the treatment of recurrent gliomas. At our center, generally re-resection is performed widely by an experienced neurosurgical team. Thus, Re-RT mostly offered to patients with macroscopic residuals or irresectable lesions, is applied later compared to other centers. Therefore, we sought to validate the Combs Prognostic Score developed in 2012 using our independent patient cohort.</p> <p><b>Patients and methods:</b> We included 199 patients treated from 2002 until April 2016 for recurrent glioma at the Department of Radiation Oncology at the Klinikum Rechts der Isar, Munich. Different concepts of Re-RT were applied.</p> <p><b>Results:</b> Median follow-up after Re-RT was 2.5 months. Median overall survival (OS) after Re-RT was 7.9 months for WHO IV gliomas, 11.3 months for WHO III gliomas, and 13.6 months for low-grade gliomas (WHO I/II). Univariate analyses confirmed the prognostic factors primary histology (p = 0.001), age (p = 0.002), and time between primary radiotherapy and Re-RT (p < 0.001). We also tested Karnofsky Performance Score (KPS), gender, and neurological symptoms before Re-RT as well as planning target volume and found only KPS also significant at p < 0.001. Comparing the prognostic score groups, the outcome was highly statistically significant at p < 0.001.</p> <p><b>Conclusion:</b> In our analysis, we validated the Combs Prognostic Score. Validation in this independent large patient cohort confirms the significance of the score for glioma recurrences. Thus, the role of the Combs Prognostic Score might be an essential component of future clinical decision making and patient stratification.</p
Scoring scheme of the new prognostic score (modification of the original scoring scheme by Combs et al. [1]).
<p>Scoring scheme of the new prognostic score (modification of the original scoring scheme by Combs et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180457#pone.0180457.ref001" target="_blank">1</a>]).</p
OS after according to the new prognostic score (p < .001).
<p>OS after according to the new prognostic score (p < .001).</p