| 11. |
- Cheng, Xiaowen, et al.
(författare)
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Tuft cells : Distribution and connections with nerves and endocrine cells in mouse intestine
- 2018
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 369:1, s. 105-111
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Tidskriftsartikel (refereegranskat)abstract
- Tuft cells are gastrointestinal (GI) sensory cells recognized by their characteristic shape and their microvilli “tuft”. Aims of the present study were to elucidate their regional distribution and spatial connections with satiety associated endocrine cells and nerve fibers throughout the intestinal tract. C57BL/6 J mice were used in the experiments. The small intestine was divided into five segments, and the large intestine was kept undivided. The segments were coiled into “Swiss rolls”. Numbers and topographic distribution of tuft cells and possible contacts with endocrine cells and nerve fibers were estimated in the different segments, using immunocytochemistry. Tuft cells were found throughout the intestines; the highest number was in proximal small intestine. Five percent of tuft cells were found in close proximity to cholecystokinin-immunoreactive (IR) endocrine cells and up to 10% were in contact with peptide YY- and glucagon-like peptide-1-IR endocrine cells. Sixty percent of tuft cells in the small intestine and 40% in the large intestine were found in contact with nerve fibers. Calcitonin gene-related peptide-IR fibers constituted one-third of the fiber-contacts in the small intestine and two-thirds in the large intestine. These observations highlight the possibility of tuft cells as modulators of GI activities in response to luminal signaling.
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| 12. |
- Ekblad, Eva
(författare)
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CART in the enteric nervous system.
- 2006
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Ingår i: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 27:8, s. 2024-2030
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Forskningsöversikt (refereegranskat)abstract
- The expression, distribution, origin, projections, chemical coding and functions of cocaine and amphetamine-regulated transcript (CART) in the gastro-intestinal tract are reviewed. CART is extensively expressed in the enteric nervous system. Except from being a possible modulator of NO induced intestinal relaxation CART does not seem to play any pivotal role in intestinal motility. Accumulating evidence suggest CART to be neuroprotective, involved in survival and maintenance of enteric neurons. CART expression increases in atrophic intestine thus suggesting a role of CART in intestinal adaptation. In rat antral mucosa CART is expressed in gastrin cells indicating a hormonal role of gastric CART.
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| 13. |
- Ekblad, Eva, et al.
(författare)
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Cocaine- and amphetamine-regulated transcript: distribution and function in rat gastrointestinal tract.
- 2003
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 15:5, s. 545-557
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Tidskriftsartikel (refereegranskat)abstract
- Cocaine- and amphetamine-regulated transcript (CART) peptide, originally isolated from brain, is also expressed in the peripheral nervous system. The distribution, origin and projections of CART-expressing enteric neurones by immunocytochemistry and in situ hybridization in rat gastrointestinal (GI) tract were studied. Possible motor functions of CART were studied in vitro using longitudinal muscle strips from stomach, ileum and colon. Cocaine- and amphetamine-regulated transcript peptide was found in numerous myenteric neurones throughout the GI tract while CART-expressing submucous neurones were scarce. Cocaine- and amphetamine-regulated transcript was also expressed in the antral gastrin cells. Myenteric CART-expressing neurones in both small and large intestine issued short descending projections. In atrophic ileum, CART mRNA-expressing neurones increased in number while neurones containing CART peptide decreased. In hypertrophied ileum, no change in CART peptide or CART mRNA containing myenteric neurones was detected. Cocaine- and amphetamine-regulated transcript 55-102 (10-9-10-7 mol L-1) did not induce any contractile or relaxatory responses in the muscle strips, neither did it affect responses induced by vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide or neuronal stimulation. In colonic, but not in ileal, strips addition of CART attenuated nitric oxide (NO) donor-induced relaxations. Although CART does not seem to play a pivotal role in classic neurotransmission to the longitudinal muscle, it may serve a modulatory role in NO transmission. It may, moreover, be involved in intestinal adaptation, and an additional hormonal role is also possible.
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| 14. |
- Ekblad, Eva, et al.
(författare)
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Distribution of pancreatic polypeptide and peptide YY.
- 2002
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Ingår i: Peptides. - 1873-5169. ; 23:2, s. 251-261
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Tidskriftsartikel (refereegranskat)abstract
- The cellular distribution of PP and PYY in mammals is reviewed. Expression of PP is restricted to endocrine cells mainly present in the pancreas predominantly in the duodenal portion (head) but also found in small numbers in the gastro-intestinal tract. PYY has a dual expression in both endocrine cells and neurons. PYY expressing endocrine cells occur all along the gastrointestinal tract and are frequent in the distal portion. Islet cells expressing PYY are found in many species. In rodents they predominate in the splenic portion (tail) of the pancreas. A limited expression of PYY is found also in endocrine cells in the adrenal gland, respiratory tract and pituitary. Peripheral, particularly enteric, neurons also express PYY as does a restricted set of central neurons.
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| 15. |
- Ekblad, Eva, et al.
(författare)
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Innervation of the small intestine.
- 2002
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Ingår i: Biology of the Intestine in Growing Animals. - 9780444509284 - 0444509283 ; , s. 235-235
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Intestinal activities are controlled and co-ordinated by way of neuronal reflexes involving both extrinsic and intramural neurones, the enteric nervous system (ENS). This review focuses on the organisation, development and functional properties of the intestinal innervation and of the neurotransmitters utilised.
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| 16. |
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| 17. |
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| 18. |
- Ekblad, Eva, et al.
(författare)
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Role of vasoactive intestinal peptide and inflammatory mediators in enteric neuronal plasticity.
- 2004
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 16:Suppl 1, s. 123-128
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Tidskriftsartikel (refereegranskat)abstract
- Complex circuits involving both local intrinsic neurones (i.e. enteric nervous system; ENS) and extrinsic neurones achieve nervous control of digestive functions. The ENS is comprised of many functionally different types of neurons: sensory neurons, interneurons and secreto-motor neurons. Each neuronal population is required to manifest local reflex behavior and is central to the regulation of both motor and secretory activities. It must be emphasized, however, that not only muscle and secretory cells but also other intestinal cells are targeted by enteric neurones, i.e. endocrine cells, interstitial cells of Cajal, immune cells, blood vessels and enteric glia. In addition to the ENS the gastrointestinal tract receives an extrinsic innervation by sympathetic, parasympathetic and sensory fibres. Neuronal projections from the intestine to prevertebral ganglia also exist. Taken together, the picture of a complex nervous regulation of digestive functions highly integrated with the central nervous system and the rest of the autonomic nervous system has emerged. The ENS is adaptive and plastic, but also vulnerable, system and ENS disturbances may be of pathogenic importance in functional bowel disease. In particular the interplay between the enteric neurones and the immune cells is suggested to be of crucial importance. The review discusses possible roles of the mediators vasoactive intestinal peptide (VIP) and prostanoids in ENS plasticity in response to injury and inflammation.
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| 19. |
- Ekblad, Lars, et al.
(författare)
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Anti- or pro-proliferation - Conditional options for TGF-α and cetuximab in head and neck squamous cell carcinoma.
- 2015
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Ingår i: Oral Oncology. - : Elsevier BV. - 1879-0593 .- 1368-8375. ; 51:1, s. 46-52
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Tidskriftsartikel (refereegranskat)abstract
- Cetuximab is an epidermal growth factor receptor (EGFR)-targeting drug that has shown effects in head and neck squamous cell carcinoma (HNSCC). The effects are, however, small and have mainly been proven in a subset of patients, and the cost-effectiveness has been questioned. For this reason, we need to know more about the basic mechanisms controlling the effect of EGFR signalling on tumour growth.
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| 20. |
- Ekelund, Mikael, et al.
(författare)
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Effects of total parenteral nutrition on rat enteric nervous system, intestinal morphology, and motility.
- 2005
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Ingår i: Journal of Surgical Research. - : Elsevier BV. - 1095-8673 .- 0022-4804. ; 124:2, s. 187-193
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Tidskriftsartikel (refereegranskat)abstract
- Total parenteral nutrition (TPN) is often crucial for patients not being able to feed enterally or having intestinal absorptive deficits. Enteral nutrition is, however, frequently regarded vital for maintaining functional and structural intestinal integrity. The aim of this study was to investigate possible effects of TPN on rat distal small intestine compared to enterally fed identically housed controls, regarding the enteric nervous system (ENS), motility in vitro, and morphology. This study shows that motor responses evoked by electrical stimulation or exposure to vasoactive intestinal peptide (VIP), pituitary adenylate cyclase activating peptide-27 (PACAP-27), and nitric oxide (NO) donor were unchanged. By using immunohistochemistry, the numbers of submucous (P < 0.05) and myenteric (P < 0.05) nerve cells were found to increase, expressed as numbers per unit length. The percentage of neurons expressing VIP, PACAP-27, NO-synthase, and galanin remained unchanged, however. By in situ hybridization the number of submucous neurons expressing neuropeptide Y-mRNA was found to decrease (P < 0.05); the other populations were unaltered. Morphometry revealed an increased submucosal thickness (P < 0.05), while intestinal circumference markedly decreased (P < 0.0001) in TPN-treated rats. In conclusion, TPN treatment resulted in reduced intestinal circumference leading to condensation of enteric neurons. No marked changes in neurotransmitter expression of the enteric neurons or in motor activity were noted.
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