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- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
- Kristanl, Matej, et al.
(författare)
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The Seventh Visual Object Tracking VOT2019 Challenge Results
- 2019
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Ingår i: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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| 7. |
- El-Salhy, M, et al.
(författare)
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Neuroendocrine peptide levels in the gastrointestinal tract of mice after unilateral cervical vagotomy
- 2000
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 88:1-3, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- The effects of left and right unilateral cervical vagotomy on the content of several neuroendocrine peptides were studied in different parts of the murine gastrointestinal tract, known to receive vagal innervation. The neuroendocrine peptides investigated were secretin, gastric inhibitory peptide (GIP), gastrin, motilin, peptide YY (PYY), somatostatin, substance P, VIP, neurotensin, neuropeptide Y (NPY), and galanin. The neuroendocrine peptide concentration was affected after both left and right vagotomy, and that the changes in the concentrations of the neuroendocrine peptide levels occurred in all the gastrointestinal segments investigated, namely antrum, small and large intestine. However, these changes varied, depending on which side was vagotomized and the interval after vagotomy. It is concluded that the vagus nerve had an important impact on the neuroendocrine system in the murine gut. It is suggested, furthermore that the contradictory results obtained earlier on the effect of vagotomy on the gastrointestinal peptides may depend on differences in the vagotomy methods used and on differences in observation time after vagotomy.
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| 8. |
- Qian, Bi-Feng
(författare)
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An experimental study on the interaction between the neuro-endocrine and immune systems in the gastrointestinal tract
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The mucosa lining of the gastrointestinal (GI) tract is in immediate contact with food nutrients to allow a rapid and efficient digestion and absorption and at the same time protects against the incessant risk of attack from pathogenic microbes. Maintenance of normal physiological activities in the GI tract is dependent on a number of regulatory interactions between the nervous, endocrine, and immune systems, as well as environmental and genetic factors. Impaired nervous and/or endocrine systems may endanger mucosal immunity and thereby increase the susceptibility to infectious agents, elicit an uncontrolled inflammatory response and cause a failure of immune surveillance. Aberrant immune functions may also lead to an apparent neuro-endocrine disturbance. A better understanding of the neuro-endocrine immunomodulation in the GI tract and its influence on the inflammatory process, therefore, will hold the promise of novel strategy to the treatment of immunologically and/or neuro-endocrinologically mediated diseases with the use of appropriate regulatory substances.In this thesis, the neuro-endocrine system and its interaction(s) with the immune system in the GI tract were studied using mouse models combined with immunological and molecular biological techniques (e.g. immunomorphometry, quantitative RT-PCR). The following could be concluded:1) Vagus nerves are fundamental to the enteric neuro-endocrine system. Frequencies and morphology of several types of endocrine cells and tissue levels of neuropeptides along the GI tract were significantly changed by vagotomy.2) The local enteric neuro-endocrine system may have important influences on bowel inflammation. Polypeptide YY (PYY) cells and tissue levels of PYY, substance P (SP) and vasoactive intestinal polypeptide (VIP) were dramatically decreased in the inflamed colon of IL-2-/- mice as compared to the health IL-2+/- and IL-2+/+ controls.3) Notably, IL-2 deficiency per se caused marked neuro-endocrine alterations in the gut. The volume densities of enteroglucagon-, serotonin-cells and SP-, VIP- or total myenteric nerves were lower in IL-2+/- and IL-2-/- mice as compared to the wild type. The normally occurring age related neuro-endocrine changes were also absent in mice with no (IL-2-/- mice) or reduced levels of IL-2 (IL-2+/- mice).4) VIP generally exerted immunosuppressive effects. The magnitude of the effect differed with T cells in different compartments. Proliferation in response to polyclonal T cell activators was significantly down-regulated by VIP in splenic but not intestinal T lymphocytes. Cytokine production was also affected. Expression of mRNAs for interleukin-2 (IL-2), the Th1 cytokine interferon-γ (IFN-γ), and the Th2 cytokine IL-4 in activated small intestinal lamina propria and splenic T cells was inhibited by VIP in a dose dependent manner. In contrast, the inhibitory action of VIP on cytokine production was much less pronounced in intestinal intraepithelial T lymphocytes in which only IFN-γ mRNA expression was reduced.5) The effects of VIP on lymphocytes are most probably receptor mediated. Intestinal T cells were shown to bind VIP. T cells in both small and large intestine as well as spleen had the mRNA expression for VIP-receptor 1. It was expressed in all T cell subtypes tested i.e. CD4+ , CD8+, and CD4-CD8-CD3+ cells. Interestingly, VIP receptor 2 mRNA was only found in CD8+ lymphocytes of small intestine. This indicates a functional diversity and specificity of VIP in immune modulation.6) SP may act as an autocrine as well as a paracrine immunoregulatory agent in intestinal mucosa. T cells from both the epithelium and lamina propria of small and large intestine were found to produce SP and at the same time express the SP receptor.
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| 9. |
- Qian, Bi-Feng, et al.
(författare)
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Both substance P and its receptor are expressed in mouse intestinal T lymphocytes
- 2001
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 73:5, s. 358-368
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Tidskriftsartikel (refereegranskat)abstract
- Substance P (SP), one of the most prevalent neuropeptides in gut, has been reported to have potent immune modulatory effects as a proinflammatory agent. The synthesis of SP and SP receptor expression in intraepithelial and lamina propria T lymphocytes of mouse intestine was investigated. Using RT-PCR analysis, it was demonstrated that SP receptor mRNA was exclusively expressed in intraepithelial and lamina propria T lymphocytes as well as their purified CD4+, CD8+ and CD4-CD8-CD3+ subsets. Messenger RNAs (mRNAs) for the two precursors of SP, beta and gamma-preprotachykinin-A, were also detected. These results were consistent in lymphocytes from both epithelium and lamina propria of small and large intestines, although the frequencies and/or intensities of mRNA expression varied. However, none of the findings could be repeated in splenic T lymphocytes. Activation of splenocytes with anti-CD3epsilon-chain mAb and PMA did not induce expression of SP or its receptor mRNAs. Furthermore, both cytoplasmic and surface-bound SP was demonstrated in intestinal T lymphocytes using dual color immunocytochemistry and immunoflow cytometry. In vitro treatment with SP did not significantly change the size of the SP-immunoreactive T cell population, indicating the presence of SP receptor on intestinal T lymphocytes as well as in vivo binding of endogenously released SP. Our data suggest that SP production and SP receptor expression are distinctive for mouse intestinal mucosal immunity and that SP may act as a modulator of an ongoing controlled inflammation in normal gut, by acting through its specific receptor on T lymphocytes in an autocrine and/or paracrine pattern.
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| 10. |
- Qian, Bi-Feng, et al.
(författare)
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Changes in intestinal endocrine cells in the mouse after unilateral cervical vagotomy
- 1999
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Ingår i: Histology and Histopathology. - 0213-3911 .- 1699-5848. ; 14:2, s. 453-460
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Tidskriftsartikel (refereegranskat)abstract
- The effect of right or left unilateral cervical vagotomy on the intestinal endocrine cells was studied in 23 mice at 2 and 8 weeks after operation, respectively. The results were compared with that from 10 sham operated mice. Various types of endocrine cells in duodenum and proximal colon were detected by immunohistochemistry and quantified by computerized image analysis. In mouse duodenum, chromogranin-, CCK/gastrin-, GIP- and somatostatin-cells were significantly decreased at 2 weeks after right vagotomy, but returned to the control levels at 8 weeks. Serotonin-cells were reduced at both 2 and 8 weeks after right vagotomy. The amount of the duodenal endocrine cells did not change after left vagotomy with the exception of secretin-cells, which were diminished at 8 weeks after both right and left vagotomy. In the proximal colon, chromogranin-cells were also decreased at 2 weeks after right vagotomy. Serotonin-cells were reduced at 8 weeks after left vagotomy but not right vagotomy. There was no significant difference between the unilaterally vagotomized and the sham operated mice with regard to PYY- and glucagon-cells. It was concluded that vagotomy affected the intestinal endocrine cells in mouse. The influence was more pronounced in the small intestine than the proximal colon. The right vagus nerves seemed to exert more effect on the intestinal endocrine cells than the left ones.
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