624 research outputs found
Retinoids Regulate a Developmental Checkpoint for Tissue Regeneration in Drosophila
SummaryDamage to Drosophila imaginal discs elicits a robust regenerative response from the surviving tissue [1–4]. However, as in other organisms, developmental progression and differentiation can restrict the regenerative capacity of Drosophila tissues. Experiments in Drosophila and other holometabolous insects have demonstrated that either damage to imaginal tissues [5, 6] or transplantation of a damaged imaginal disc [7, 8] delays the onset of metamorphosis. Therefore, in Drosophila there appears to be a mechanism that senses tissue damage and extends the larval phase to coordinate tissue regeneration with the overall developmental program of the organism. However, how such a pathway functions remains unknown. Here we demonstrate that a developmental checkpoint extends larval growth after imaginal disc damage by inhibiting the transcription of the gene encoding PTTH, a neuropeptide that promotes the release of the steroid hormone ecdysone. Using a genetic screen, we identify a previously unsuspected role for retinoid biosynthesis in regulating PTTH expression and delaying development in response to tissue damage. Retinoid signaling plays an important but poorly defined role in several vertebrate regeneration models [9–11]. Our findings demonstrate that retinoid biosynthesis in Drosophila is important for the maintenance of a condition that is permissive for regenerative growth
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Contains reports on three research projects.National Aeronautics and Space Administration (Grant NGL-22-009-013)Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E
Terahertz Security Image Quality Assessment by No-reference Model Observers
To provide the possibility of developing objective image quality assessment
(IQA) algorithms for THz security images, we constructed the THz security image
database (THSID) including a total of 181 THz security images with the
resolution of 127*380. The main distortion types in THz security images were
first analyzed for the design of subjective evaluation criteria to acquire the
mean opinion scores. Subsequently, the existing no-reference IQA algorithms,
which were 5 opinion-aware approaches viz., NFERM, GMLF, DIIVINE, BRISQUE and
BLIINDS2, and 8 opinion-unaware approaches viz., QAC, SISBLIM, NIQE, FISBLIM,
CPBD, S3 and Fish_bb, were executed for the evaluation of the THz security
image quality. The statistical results demonstrated the superiority of Fish_bb
over the other testing IQA approaches for assessing the THz image quality with
PLCC (SROCC) values of 0.8925 (-0.8706), and with RMSE value of 0.3993. The
linear regression analysis and Bland-Altman plot further verified that the
Fish__bb could substitute for the subjective IQA. Nonetheless, for the
classification of THz security images, we tended to use S3 as a criterion for
ranking THz security image grades because of the relatively low false positive
rate in classifying bad THz image quality into acceptable category (24.69%).
Interestingly, due to the specific property of THz image, the average pixel
intensity gave the best performance than the above complicated IQA algorithms,
with the PLCC, SROCC and RMSE of 0.9001, -0.8800 and 0.3857, respectively. This
study will help the users such as researchers or security staffs to obtain the
THz security images of good quality. Currently, our research group is
attempting to make this research more comprehensive.Comment: 13 pages, 8 figures, 4 table
Granulomatous cheilitis associated with exacerbations of Crohn's disease: a case report
<p>Abstract</p> <p>Introduction</p> <p>Crohn's disease is a disease involving the whole gastrointestinal tract from the mouth to the anus. Oral lesions are considered to be an important extraintestinal manifestation. Granulomatous cheilitis has been recognized as an early manifestation of Crohn's disease. It may follow, coincide with or precede the onset of Crohn's disease. The aim of this presentation is to describe a rare case of a patient with Crohn's disease in whom significant swelling of the lower lip not only preceded the diagnosis of Crohn's disease for two years, but it manifested as an early clinical index of the recurrence of the intestinal disease as well.</p> <p>Case presentation</p> <p>A man aged 25 was admitted in our department on August 1999 with chronic diarrhea and loss of weight. His bowel symptoms started in 1998 at the age of 24. However, two years previously (June 1996) he noticed a swelling of the lower lip, which contrasted significantly with the previously normal appearance of his mouth. A lip biopsy performed at that time was compatible with granulomatous cheilitis. Crohn's disease involving the terminal ileum and large bowel was diagnosed in 1998 and confirmed on the basis of colonoscopy, enteroclysis and histology findings of the small and large bowel. Conservative treatment resulted in clinical and laboratory improvement of the bowel symptoms and lip swelling. During the following years the disease was active with exacerbations and remissions of mild to moderate severity. The swelling of the lower lip occurred in parallel with the exacerbations of the bowel disease, returning to normal during periods of remission.</p> <p>Conclusion</p> <p>Significant swelling of the lower lip due to granulomatous cheilitis could be the first manifestation of Crohn's disease, preceding intestinal symptoms. Exacerbation of the lip lesion could be an early clinical sign of a relapse of the underlying intestinal disease.</p
IFN-gamma Impairs Release of IL-8 by IL-1beta-stimulated A549 Lung Carcinoma Cells
Background Production of interferon (IFN)-gamma is key to efficient anti-tumor immunity. The present study was set out to investigate effects of IFNgamma on the release of the potent pro-angiogenic mediator IL-8 by human A549 lung carcinoma cells.
Methods A549 cells were cultured and stimulated with interleukin (IL)-1beta alone or in combination with IFNgamma. IL-8 production by these cells was analyzed with enzyme linked immuno sorbent assay (ELISA). mRNA-expression was analyzed by real-time PCR and RNase protection assay (RPA), respectively. Expression of inhibitor-kappaBalpha, cellular IL-8, and cyclooxygenase-2 was analyzed by Western blot analysis.
Results Here we demonstrate that IFNgamma efficiently reduced IL-8 secretion under the influence of IL-1beta. Surprisingly, real-time PCR analysis and RPA revealed that the inhibitory effect of IFNgamma on IL-8 was not associated with significant changes in mRNA levels. These observations concurred with lack of a modulatory activity of IFNgamma on IL-1beta-induced NF-kappaB activation as assessed by cellular IkappaB levels. Moreover, analysis of intracellular IL-8 suggests that IFNgamma modulated IL-8 secretion by action on the posttranslational level. In contrast to IL-8, IL-1beta-induced cyclooxygenase-2 expression and release of IL-6 were not affected by IFNgamma indicating that modulation of IL-1beta action by this cytokine displays specificity.
Conclusions Data presented herein agree with an angiostatic role of IFNgamma as seen in rodent models of solid tumors and suggest that increasing T helper type 1 (Th1)-like functions in lung cancer patients e.g. by local delivery of IFNgamma may mediate therapeutic benefit via mechanisms that potentially include modulation of pro-angiogenic IL-8
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