SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "L773:1432 0878 "

Sökning: L773:1432 0878

  • Resultat 1-50 av 189
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  •  
2.
  •  
3.
  • Alim, Md Abdul, et al. (författare)
  • Increased mast cell degranulation and co-localization of mast cells with the NMDA receptor-1 during healing after Achilles tendon rupture
  • 2017
  • Ingår i: Cell and Tissue Research. - Berlin Heidelberg : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 370:3, s. 451-460
  • Tidskriftsartikel (refereegranskat)abstract
    • The role of inflammation and the mechanism of tendon healing after rupture has historically been a matter of controversy. The purpose of the present study is to investigate the role of mast cells and their relation to the NMDA receptor-1 (a glutamate receptor) during healing after Achilles tendon rupture. Eight female Sprague Dawley rats had their right Achilles tendon transected. Three weeks after rupture, histological quantification of mast cell numbers and their state of degranulation was assessed by histochemistry. Co-localization of mast cell tryptase (a mast cell marker) and NMDA receptor-1 was determined by immunofluorescence. The intact left Achilles tendon was used as control. An increased number of mast cells and a higher proportion of degranulated mast cells were found in the healing Achilles tendon compared to the intact. In addition, increased co-localization of mast cell tryptase and NMDA receptor-1 was seen in the areas of myotendinous junction, mid-tendon proper and bone tendon junction of the healing versus the intact tendon. These findings introduce a possible role for mast cells in the healing phase after Achilles tendon rupture.
  •  
4.
  • Alves, R. N., et al. (författare)
  • Structural and functional maturation of skin during metamorphosis in the Atlantic halibut (Hippoglossus hippoglossus)
  • 2018
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 372:3, s. 469-492
  • Tidskriftsartikel (refereegranskat)abstract
    • To establish if the developmental changes in the primary barrier and osmoregulatory capacity of Atlantic halibut skin are modified during metamorphosis, histological, histochemical, gene expression and electrophysiological measurements were made. The morphology of the ocular and abocular skin started to diverge during the metamorphic climax and ocular skin appeared thicker and more stratified. Neutral mucins were the main glycoproteins produced by the goblet cells in skin during metamorphosis. Moreover, the number of goblet cells producing neutral mucins increased during metamorphosis and asymmetry in their abundance was observed between ocular and abocular skin. The increase in goblet cell number and their asymmetric abundance in skin was concomitant with the period that thyroid hormones (THs) increase and suggests that they may be under the control of these hormones. Several mucin transcripts were identified in metamorphosing halibut transcriptomes and Muc18 and Muc5AC were characteristic of the body skin. Na+, K+-ATPase positive (NKA) cells were observed in skin of all metamorphic stages but their number significantly decreased with the onset of metamorphosis. No asymmetry was observed between ocular and abocular skin in NKA cells. The morphological changes observed were linked to modified skin barrier function as revealed by modifications in its electrophysiological properties. However, the maturation of the skin functional characteristics preceded structural maturation and occurred at stage 8 prior to the metamorphic climax. Treatment of Atlantic halibut with the THs disrupter methimazole (MMI) affected the number of goblet cells producing neutral mucins and the NKA cells. The present study reveals that the asymmetric development of the skin in Atlantic halibut is TH sensitive and is associated with metamorphosis and that this barrier's functional properties mature earlier and are independent of metamorphosis.
  •  
5.
  • Andersson, K, et al. (författare)
  • Effect of a-fluoromethylhistidine-evoked histamine depletion on ultrastructure of endocrine cells in acid-producing mucosa of stomach in mouse, rat and hamster
  • 1996
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 286:3, s. 84-375
  • Tidskriftsartikel (refereegranskat)abstract
    • The oxyntic mucosa of the mammalian stomach is rich in endocrine cells, such as ECL cells, A-like cells, somatostatin cells, D1/P cells and, in some species, enterochromaffin cells. The various endocrine cell types can be distinguished on the basis of their characteristic cytoplasmic granules and vesicles. The ECL cells contain numerous large secretory vesicles and relatively few, small electron-dense granules and small clear microvesicles. We have suggested that in the rat the ECL cells contain most of the gastric histamine with the secretory vesicles as the major histamine storage site in these cells. alpha-Fluoromethylhistidine is an irreversible inhibitor of histidine decarboxylase, the histamine-forming enzyme. We have previously shown that this enzyme inhibitor depletes histamine from the ECL cells in the rat and reduces the number of secretory vesicles in the cytoplasm. In the present study, we have examined whether alpha-fluoromethylhistidine affects the ECL cells in other species and whether it affects other types of endocrine cells in the oxyntic mucosa of the rat. Mice, rats and hamsters were treated with the inhibitor (3 mg/kg per h) via minipumps subcutaneously for 24 h. This treatment lowered the oxyntic mucosal histamine concentration by 65-90% and the number and volume density of the secretory vesicles by 85-95% in the ECL cells of the three species examined. In contrast, the number and volume density of granules and microvesicles were not greatly affected. No evidence was found for an effect of alpha-fluoromethylhistidine on A-like cells, somatostatin cells or D1/P cells of the rat stomach, suggesting that, unlike the ECL cells, they do not contain histamine.
  •  
6.
  • Andersson, K, et al. (författare)
  • Enterochromaffin-like cells in the rat stomach: effect of depletion. A chemical, histochemical and electron-microscopic study
  • 1992
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 270:1, s. 7-13
  • Tidskriftsartikel (refereegranskat)abstract
    • In the rat, gastric histamine is stored predominantly in the enterochromaffin-like (ECL) cells, which are located basally in the oxyntic mucosa. The functional significance of histamine in the ECL cells is a matter of speculation. In this study the effect of depletion of histamine on the properties and ultrastructure of the ECL cells was examined. Histamine synthesis was inhibited with alpha-fluoromethylhistidine (3 mg.kg-1.h-1) given via osmotic minipumps over a period of 24 h. The treatment reduced the histidine decarboxylase activity (approximately 20% remaining) and histamine concentration (less than 20% remaining) in the oxyntic mucosa, as well as the intensity of histamine- and chromogranin A-immunostaining in the ECL cells, compared to control rats. The cytoplasmic (secretory) granules/vesicles were greatly reduced in number and size following alpha-fluoromethylhistidine administration. The histamine immunostaining of the mast cells, which occurs at the mucosal surface and in the submucosa, appeared unaffected. We conclude that ECL cell histamine accounts for at least 80% of the total oxyntic mucosal histamine in the rat and that it represents a more mobile pool than mast cell histamine. The reduction in the number and size of the ECL cell granules/vesicles following histamine depletion is in accord with the idea that they represent the storage site for histamine.
  •  
7.
  • Aramant, Robert, et al. (författare)
  • Distribution of monoaminergic neurons in the nervous system of non-Malacostracan crustaceans
  • 1976
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 166, s. 1-24
  • Tidskriftsartikel (refereegranskat)abstract
    • A comparative investigation of the distribution of monoaminergic neurons in non-malacostracan crustaceans was performed with the histochemical fluorescence method of Falck-Hillarp.Two fluorophores were found: the more widespread of the two emits a green fluorescence; and the more sparsely distributed emits a yellow to brown-yellow fluorescence.Specific green fluorescent areas were shown to exist in the protocerebrum. The central body and the optic ganglia of the compound eye (where present) are always fluorescent. Moreover, the centre of the nauplius eye may have a green fluorophore, as in ostracods, and a neuropile area, here called the frontal area. These neuropile centres are known from ordinary histological studies of the nervous system. In addition, there are specific monoaminergic centres, such as the so-called dorsal area of phyllopods and anostracans as well as the copepod specific areas. Specific monoaminergic areas appear in the deutocerebrum and the suboesophageal ganglion where they are particularly well developed.Presumed sensory neurons in the cavity receptor organ of Artemia salina are shown to be monoaminergic. Monoaminergic sensory neurons have not been described previously in Arthropods.Presumed motor innervation of hind-gut and trunk muscles is also found, and it is concluded that in crustaceans neurons of every type (sensory, internuncial, motor) may be monoaminergic.
  •  
8.
  • Aramant, Robert, et al. (författare)
  • Monoaminergic neurons in the nervous system of crustaceans.
  • 1976
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 170, s. 231-251
  • Tidskriftsartikel (refereegranskat)abstract
    • Certain neurons in the nervous system of the malacostracan crustaceans give rise to a predominantly green and a sparse yellow fluorophore in the histochemical fluorescence method of Falck-Hillarp. The same applies to the whole of Crustacea. The green fluorophore is probably a catecholamine; the yellow to brown-yellow has not yet been identified.The biogenic amine responsible for the green fluorescence, besides being found in diffusely distributed fibres, also appears in distinct areas of fibre concentrations in the central nervous system. The protocerebrum of the malacostracans contains three areas: the central body and two areas in the top of the brain, one anterior and one posterior. The latter two are not recognized as separate areas in ordinary histological preparations. In addition, the optic neuropiles are fluorescent, some with a distinct stratification of the fluorophore. The deuto and tritocerebrum and the ventral nerve cord also contain monoaminergic neurons. Of the brightly fluorescent areas in the whole of Crustacea, only the central body consistently exists in all species. The other areas of concentrated fluorescent neuropile are restricted to smaller taxonomic units and differ from each other. p The monoaminergic neurons in Crustacea are sensory, motor, and internuncial, and also belong to a fourth type which mimics the neurosecretory neurons in neurohaemal organs. Only one example of a monoaminergic sensory neuron is known (in Anemia, a non-malacostracan, Aramant and Elofsson 1976), a few motor and a few neurosecretory mimics (the latter in malacostracans). Most are internuncials.
  •  
9.
  • Audehm, Uwe, et al. (författare)
  • Patterns and projections of crustacean cardioactive-peptide-immunoreactive neurons of the terminal ganglion of crayfish.
  • 1993
  • Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 272:3, s. 473-485
  • Tidskriftsartikel (refereegranskat)abstract
    • Three distinct clusters of crustacean cardioactive-peptide-immunoreactive neurones occur in the terminal abdominal ganglion of the crayfish species Orconectes limosus, Astacus leptodactylus, Astacus astacus and Procambarus clarkii, as revealed by immunocytochemistry of whole-mount preparations and sections. They exhibit similar topology and projection patterns in all four studied species. An anterior ventral lateral and a posterior lateral cluster contain one small, strongly stained perikaryon and two large, less intensely stained perikarya, each showing contralateral projections. A posterior medial lateral cluster of up to six cells also contains these two types of perikarya. Whereas the small type perikarya belong to putative interneurones, the large type perikarya give rise to extensive neurohaemal plexuses in perineural sheaths of the third roots of the fifth abdominal ganglia, the connectives, the dorsal telson nerves, the ganglion itself, its roots and arteriolar supply. Thin fibres from these plexuses reach newly discovered putative neurohaemal areas around the hindgut and anus via the intestinal and the anal nerves, and directly innervate the phasic telson musculature. A comparison with earlier investigations of motoneurones and segmentation indicates that these three cell groups containing putative neurosecretory neurones may be members of at least three neuromeres in this ganglion. Crustacean cardioactive peptide released from these neurones may participate in the neurohumoral and modulatory control of different neuronal and muscle targets, thereby exceeding its previously established hindgut and heart excitatory effects.
  •  
10.
  • Bjur, Dennis, 1965-, et al. (författare)
  • Presence of a non-neuronal cholinergic system and occurrence of up- and down-regulation in expression of M2 muscarinic acetylcholine receptors : new aspects of importance regarding Achilles tendon tendinosis (tendinopathy)
  • 2008
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 331:2, s. 385-400
  • Tidskriftsartikel (refereegranskat)abstract
    • Limited information is available concerning the existence of a cholinergic system in the human Achilles tendon. We have studied pain-free normal Achilles tendons and chronically painful Achilles tendinosis tendons with regard to immunohistochemical expression patterns of the M(2) muscarinic acetylcholine receptor (M(2)R), choline acetyltransferase (ChAT), and vesicular acetylcholine transporter (VAChT). M(2)R immunoreactivity was detected in the walls of blood vessels. As evidenced via parallel staining for CD31 and alpha-smooth muscle actin, most M(2)R immunoreactivity was present in the endothelium. M(2)R immunoreactivity also occured in tenocytes, which regularly immunoreact for vimentin. The degree of M(2)R immunoreactivity was highly variable, tendinosis tendons that exhibit hypercellularity and hypervascularity showing the highest levels of immunostaining. Immunoreaction for ChAT and VAChT was detected in tenocytes in tendinosis specimens, particularly in aberrant cells. In situ hybridization revealed that mRNA for ChAT is present in tenocytes in tendinosis specimens. Our results suggest that autocrine/paracrine effects occur concerning the tenocytes in tendinosis. Up-regulation/down-regulation in the levels of M(2)R immunoreactivity possibly take place in tenocytes and blood vessel cells during the various stages of tendinosis. The presumed local production of acetylcholine (ACh), as evidenced by immunoreactivity for ChAT and VAChT and the detection of ChAT mRNA, appears to evolve in response to tendinosis. These observations are of importance because of the well-known vasoactive, trophic, and pain-modulating effects that ACh is known to have and do unexpectedly establish the presence of a non-neuronal cholinergic system in the Achilles tendon.
  •  
11.
  • Bjur, Dennis, 1965-, et al. (författare)
  • The innervation pattern of the human Achilles tendon : studies of the normal and tendinosis tendon with markers for general and sensory innervation
  • 2005
  • Ingår i: Cell and Tissue Research. - Berlin / Heidelberg : Springer. - 0302-766X .- 1432-0878. ; 320:1, s. 201-206
  • Tidskriftsartikel (refereegranskat)abstract
    • Pain-free normal Achilles tendons and chronic painful Achilles tendons were examined by the use of antibodies against a general nerve marker (protein gene-product 9.5, PGP9.5), sensory markers (substance P, SP; calcitonin gene-related peptide, CGRP), and immunohistochemistry. In the normal tendons, immunoreactions against PGP9.5 and against SP/CGRP were encountered in the paratendinous loose connective tissue, being confined to nerve fascicles and to nerve fibers located in the vicinity of blood vessels. To some extent, these immunoreactions also occurred in the tendon tissue proper. Immunoreaction against PGP9.5 and against SP/CGRP was also observed in the tendinosis samples and included immunoreactive nerve fibers that were intimately associated with small blood vessels. In conclusion, Mechanoreceptors (sensory corpuscles) were occasionally observed, nerve-related components are present in association with blood vessels in both the normal and the tendinosis tendon.
  •  
12.
  • Braekeveldt, Noémie, et al. (författare)
  • Patient-derived xenografts as preclinical neuroblastoma models
  • 2018
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 372:2, s. 233-243
  • Tidskriftsartikel (refereegranskat)abstract
    • The prognosis for children with high-risk neuroblastoma is often poor and survivors can suffer from severe side effects. Predictive preclinical models and novel therapeutic strategies for high-risk disease are therefore a clinical imperative. However, conventional cancer cell line-derived xenografts can deviate substantially from patient tumors in terms of their molecular and phenotypic features. Patient-derived xenografts (PDXs) recapitulate many biologically and clinically relevant features of human cancers. Importantly, PDXs can closely parallel clinical features and outcome and serve as excellent models for biomarker and preclinical drug development. Here, we review progress in and applications of neuroblastoma PDX models. Neuroblastoma orthotopic PDXs share the molecular characteristics, neuroblastoma markers, invasive properties and tumor stroma of aggressive patient tumors and retain spontaneous metastatic capacity to distant organs including bone marrow. The recent identification of genomic changes in relapsed neuroblastomas opens up opportunities to target treatment-resistant tumors in well-characterized neuroblastoma PDXs. We highlight and discuss the features and various sources of neuroblastoma PDXs, methodological considerations when establishing neuroblastoma PDXs, in vitro 3D models, current limitations of PDX models and their application to preclinical drug testing.
  •  
13.
  • Breidbach, O, et al. (författare)
  • Common general morphological pattern of peptidergic neurons in the arachnid brain : crustacean cardioactive peptide-immunoreactive neurons in the protocerebrum of seven arachnid species.
  • 1995
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 279:1, s. 183-197
  • Tidskriftsartikel (refereegranskat)abstract
    • A polyclonal antiserum raised against crustacean cardioactive peptide labels 14 clusters of immunoreactive neurons in the protocerebrum of the spiders Tegenaria atrica and Nephila clavipes, and the harvestman (opilionid) Rilaena triangularis. In all species, these clusters possess the same number of neurons, and share similar structural and topological characteristics. Two sets of bilateral symmetrical neurons associated with the optic lobes and the arachnid "central body" were analysed in detail, comparing the harvestman R. triangularis and the spiders Brachypelma albopilosa (Theraphosidae), Cupiennius salei (Lycosidae), Tegenaria atrica (Agelenidae), Meta segmentata (Metidae) and Nephila clavipes (Araneidae). Sixteen neurons have been identified that display markedly similar axonal pathways and arborization patterns in all species. These neurons are considered homologues in the opilionid and the araneid brains. We presume that these putative phylogenetically persisting neurons represent part of the general morphological pattern of the arachnid brain.
  •  
14.
  • Breidbach, Olaf, et al. (författare)
  • Crustacean cardioactive peptide-immunoreactive neurons in the ventral nerve cord and the brain of the meal beetle Tenebrio molitor during postembryonic development
  • 1991
  • Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 265:1, s. 129-144
  • Tidskriftsartikel (refereegranskat)abstract
    • By use of an antiserum against the crustacean cardioactive peptide (CCAP) several types of bilaterally symmetrical neurons were mapped quantitatively in the ventral nerve cord and brain of Tenebrio molitor. The general architecture of these neurons was reconstructed. From the suboesophageal to the 7th abdominal ganglia 2 types of neurons showed a repetitive organization of contralateral projection patterns in each neuromere. The first type had few branches in the central neuropil and a distinct peripheral projection. The 2nd type was characterized by an elaborate central branching pattern, which included ascending and descending processes. Some of its peripheral branches supplied peripheral neurohaemal areas. In the protocerebrum, 10 CCAP-immunoreactive neurons occurred with projections into the superior median protocerebrum and the tritocerebrum. Immunopositive neurons were mapped in larvae, pupae and adults. All types of identified neurons persisted throughout metamorphosis, maintaining their essential structural and topological characteristics. The CCAP-immunoreactive neurons of T. molitor were compared with those described for Locusta migratoria. Putative structural homologies of subsets of neurons in both species are discussed.
  •  
15.
  • Breidbach, Olaf, et al. (författare)
  • Proctolin-immunoreactive neurons persist during metamorphosis of an insect: A developmental study of the ventral nerve cord of Tenebrio molitor(Coleoptera)
  • 1989
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 257:1, s. 217-225
  • Tidskriftsartikel (refereegranskat)abstract
    • Proctolin-immunoreactive neurons in all neuromers of the ventral nerve cord of Tenebrio molitor L. have been quantitatively demonstrated and mapped throughout metamorphosis. Each neuromer contains an anterior and a posterior group of neurons with light and dark staining properties as revealed by peroxidase-antiperoxidase labeling. Serial homologous subsets of dark staining neurons with central and peripheral projections have been identified and found to persist during morphogenetic changes from the larva to the adult. Most neurons maintain their topological and structural characteristics throughout metamorphosis. The identified proctolin-immunoreactive neurons exhibit structures similar to those described in other insect species; some may correspond known motoneurons.
  •  
16.
  • Briley Saebo, Karen, et al. (författare)
  • Hepatic cellular distribution and degradation of iron oxide nanoparticles following single intravenous injection in rats : implications for magnetic resonance imaging
  • 2004
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 316:3, s. 315-323
  • Tidskriftsartikel (refereegranskat)abstract
    • The purpose of this study was to determine the cellular distribution and degradation in rat liver following intravenous injection of superparamagnetic iron oxide nanoparticles used for magnetic resonance imaging (NC100150 Injection). Relaxometric and spectrophotometric methods were used to determine the concentration of the iron oxide nanoparticles and their degradation products in isolated rat liver parenchymal, endothelial and Kupffer cell fractions. An isolated cell phantom was also constructed to quantify the effect of the degradation products on the loss of MR signal in terms of decreased transverse relaxation times, T2*. The results of this study show that iron oxide nanoparticles found in the NC100150 Injection were taken up and distributed equally in both liver endothelial and Kupffer cells following a single 5 mg Fe/kg body wt. bolus injection in rats. Whereas endothelial and Kupffer cells exhibited similar rates of uptake and degradation, liver parenchymal cells did not take up the NC100150 Injection iron oxide particles. Light-microscopy methods did, however, indicate an increased iron load, presumably as ferritin/hemosiderin, within the hepatocytes 24 h post injection. The study also confirmed that compartmentalisation of ferritin/hemosiderin may cause a significant decrease in the MRI signal intensity of the liver. In conclusion, the combined results of this study imply that the prolonged presence of breakdown product in the liver may cause a prolonged imaging effect (in terms of signal loss) for a time period that significantly exceeds the half-life of NC100150 Injection iron oxide nanoparticles in liver.
  •  
17.
  • Brisslert, Mikael, 1974, et al. (författare)
  • Intra-peritoneal sRAGE treatment induces alterations in cellular distribution of CD19(+), CD3 (+) and Mac-1 (+) cells in lymphoid organs and peritoneal cavity.
  • 2013
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 351:1, s. 139-48
  • Tidskriftsartikel (refereegranskat)abstract
    • Receptor for advanced glycation end products (RAGE) is a pattern recognition receptor that binds a variety of pro-inflammatory ligands. Its soluble form, sRAGE, can compete for ligand binding and thereby have an anti-inflammatory effect. We have recently reported that sRAGE also exerts pro-inflammatory and chemotactic properties suggesting a dual role for sRAGE in immune modulation. Our present aim was to analyse the immunomodulatory properties of sRAGE in vivo with respect to acquired immunity. Naive mice were treated intra-peritoneally with sRAGE and cells from peritoneal lavage, spleens and bone marrow were examined. Mice treated with sRAGE displayed an increased leucocyte count in the peritoneal cavity, enlarged spleens and increased cellularity compared with vehicle-treated animals. Furthermore, sRAGE-treated mice had a significantly increased frequency and number of CD19(+) B cells in spleen and a reduced frequency of CD19(+) B cells in bone marrow compared with controls. Functionally, splenocytes from sRAGE-treated mice showed elevated IgG production and up to a four-fold increased IgM secretion compared with control animals and produced significantly higher levels of interleukin-10, interferon-γ and interleukin-6 in response to lipopolysaccharide stimulation. Our results suggest that sRAGE has immunomodulatory properties, since intra-peritoneal administration of sRAGE into healthy mice leads to rearrangements in cellular composition in the bone marrow and spleen. Moreover, the administration of sRAGE directs B cells into the spleen and towards differentiation. Our novel findings indicate that sRAGE exerts an effect on the cells of adaptive immunity.
  •  
18.
  •  
19.
  • Carlsson, Mikael A., et al. (författare)
  • Distribution of short neuropeptide F and its receptor in neuronal circuits related to feeding in larval Drosophila
  • 2013
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 353:3, s. 511-523
  • Tidskriftsartikel (refereegranskat)abstract
    • Four forms of short neuropeptide F (sNPF1-4), derived from the gene snpf, have been identified in Drosophila and are known to act on a single G-protein-coupled receptor (sNPFR). Several functions have been suggested for sNPFs in Drosophila, including the regulation of feeding and growth in larvae, the control of insulin signalling and the modulation of neuronal circuits in adult flies. Furthermore, sNPF has been shown to act as a nutritional state-dependent neuromodulator in the olfactory system. The role of sNPF in the larval nervous system is less well known. To analyse sites of action of sNPF in the larva, we mapped the distribution of sNPF- and sNPFR-expressing neurons. In particular, we studied circuits associated with chemosensory inputs and systems involved in the regulation of feeding, including neurosecretory cell systems and the hypocerebral ganglion. We employed a combination of immunocytochemistry and enhancer trap and promoter Gal4 lines to drive green fluorescent protein. We found a good match between the distribution of the receptor and its ligand. However, several differences between the larval and adult systems were observed. Thus, neither sNPF nor its receptor was found in the olfactory (or other sensory) systems in the larva and cells producing insulin-like peptides did not co-express sNPFR, as opposed to results from adults. Moreover, sNPF was expressed in a subpopulation of Hugin cells (second-order gustatory neurons) only in adult flies. We propose that the differences in sNPF signalling between the developmental stages is explained by differences in their feeding behaviour.
  •  
20.
  • Chacko, Lejo Johnson, et al. (författare)
  • Early appearance of key transcription factors influence the spatiotemporal development of the human inner ear
  • 2020
  • Ingår i: Cell and Tissue Research. - : SPRINGER. - 0302-766X .- 1432-0878. ; 379:3, s. 459-471
  • Tidskriftsartikel (refereegranskat)abstract
    • Expression patterns of transcription factors leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), transforming growth factor-beta-activated kinase-1 (TAK1), SRY (sex-determining region Y)-box 2 (SOX2), and GATA binding protein 3 (GATA3) in the developing human fetal inner ear were studied between the gestation weeks 9 and 12. Further development of cochlear apex between gestational weeks 11 and 16 (GW11 and GW16) was examined using transmission electron microscopy. LGR5 was evident in the apical poles of the sensory epithelium of the cochlear duct and the vestibular end organs at GW11. Immunostaining was limited to hair cells of the organ of Corti by GW12. TAK1 was immune positive in inner hair cells of the organ of Corti by GW12 and colocalized with p75 neurotrophic receptor expression. Expression for SOX2 was confined primarily to the supporting cells of utricle at the earliest stage examined at GW9. Intense expression for GATA3 was presented in the cochlear sensory epithelium and spiral ganglia at GW9. Expression of GATA3 was present along the midline of both the utricle and saccule in the zone corresponding to the striolar reversal zone where the hair cell phenotype switches from type I to type II. The spatiotemporal gradient of the development of the organ of Corti was also evident with the apex of the cochlea forming by GW16. It seems that highly specific staining patterns of several transcriptions factors are critical in guiding the genesis of the inner ear over development. Our findings suggest that the spatiotemporal gradient in cochlear development extends at least until gestational week 16.
  •  
21.
  • Chacko, L. Johnson, et al. (författare)
  • Role of BDNF and neurotrophic receptors in human inner ear development
  • 2017
  • Ingår i: Cell and Tissue Research. - : SPRINGER. - 0302-766X .- 1432-0878. ; 370:3, s. 347-363
  • Tidskriftsartikel (refereegranskat)abstract
    • The expression patterns of the neurotrophin, brain-derived neurotrophic factor, BDNF, and the neurotrophic receptors-p75NTR and Trk receptors-in the developing human fetal inner ear between the gestational weeks (GW) 9 to 12 are examined via in situ hybridization and immunohistochemistry. BDNF mRNA expression was highest in the cochlea at GW 9 but declined in the course of development. In contrast to embryonic murine specimens, a decline in BDNF expression from the apical to the basal turn of the cochlea could not be observed. p75NTR immunostaining was most prominent in the nerve fibers that penetrate into the sensory epithelia of the cochlea, the urticule and the saccule as gestational age progresses. TrkB and TrkC expression intensified towards GW 12, at which point the BDNF mRNA localization was at its lowest. TrkA expression was limited to fiber subpopulations of the facial nerve at GW 10. In the adult human inner ear, we observed BDNF mRNA expression in the apical poles of the cochlear hair cells and supporting cells, while in the adult human utricle, the expression was localized in the vestibular hair cells. We demonstrate the highly specific staining patterns of BDNF mRNA and its putative receptors over a developmental period in which multiple hearing disorders are manifested. Our findings suggest that BDNF and neurotrophin receptors are important players during early human inner ear development. In particular, they seem to be important for the survival of the afferent sensory neurons.
  •  
22.
  • Cheng, Xiaowen, et al. (författare)
  • A novel serotonin-containing tuft cell subpopulation in mouse intestine
  • 2019
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 376:2, s. 189-197
  • Tidskriftsartikel (refereegranskat)abstract
    • In this study, a novel subset of doublecortin-like kinase 1 (DCLK1)-immunoreactive (IR) tuft cells that also contain serotonin (5-hydroxytryptamine, 5HT) is described, in terms of their number, regional distribution, possible synthesis or reuptake of 5HT and proximity to 5-HT-containing enterochromaffin (EC) cells. The small intestine from C57BL/6J mice was divided into five segments while the large intestine was kept undivided. Double immunostaining was used to estimate numbers and topographic distribution of 5HT-IR (DCLK1/5HT) tuft cells and their possible expression of tryptophan hydroxylase (TPH) and serotonin transporter (SERT). Also, possible contacts between tuft cells and 5HT-IR EC cells were studied. In the small intestine, up to 80% of all tuft cells were identified as DCLK1/5HT-IR; in the large intestine, such cells were rare. The highest number of DCLK1/5HT-IR cells was found in the upper small intestine. The numbers of DCLK1/5HT-IR cells gradually decreased distally. DCLK1-IR tuft cells were not found to contain TPH, the rate-limiting enzyme in 5HT synthesis. SERT, the selective transporter for 5HT reuptake, could not convincingly be demonstrated in tuft cells. In villi and crypts, 3% and 10%, respectively, of all DCLK1-IR cells were in close proximity to EC cells. EC cells in close proximity to DCLK1-IR cells were, in villi and crypts, 3 and 8%, respectively. We conclude that DCLK1/5HT-IR cells constitute a novel subset of tuft cells that may have unique roles in the GI tract.
  •  
23.
  • Christoffersson, Gustaf, et al. (författare)
  • The neutrophil : one cell on many missions or many cells with different agendas?
  • 2018
  • Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 371:3, s. 415-423
  • Forskningsöversikt (refereegranskat)abstract
    • The unique role of neutrophils in host defense is not only based on their abilities to kill bacteria but is also due to their abundance in circulation and their ability to quickly migrate and accumulate in great numbers at afflicted sites. The high number of circulating neutrophils is the result of regulated release of new neutrophils from bone marrow as well as from marginated pools to balance their recruitment to tissue. Marginated pools, such as the spleen and lung, have previously been attributed to passively delay neutrophil transit time due to their large capillary network, but recent reports demonstrate that they are comprised of neutrophils with specific functions. The spleen, for instance, holds neutrophil subpopulations at different anatomical locations with distinct functions important for, e.g., bacterial eradication, and the lung was recently shown to re-educate neutrophils that had trafficked from a site of sterile injury to home back to bone marrow for elimination. Further, recent reports demonstrate subpopulations of neutrophils with different actions during homeostasis, infection, tissue restitution and cancer. It is becoming increasingly clear that this cannot be due to different stages of neutrophil activation during their life span but instead points towards distinct subpopulations of neutrophils with different effector functions. Whether these cellular distinctions are due to different education or origin is, however, not yet known. Together, the accumulating information about the heterogeneous neutrophils presents important insights into their role in development of pathologies, as well as revealing novel targets in the form of certain subpopulations to treat disease.
  •  
24.
  • Degerman, Eva, et al. (författare)
  • Expression of insulin signalling components in the sensory epithelium of the human saccule.
  • 2013
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 352:3, s. 469-478
  • Tidskriftsartikel (refereegranskat)abstract
    • Several studies have demonstrated a link between diabetes and the dysfunction of the inner ear. Few studies, however, have reported the signalling mechanisms involved in metabolic control in human inner ear cells. Knowledge of the expression and role of the insulin receptor and downstream signalling components in the inner ear is sparce. Our immunohistochemistry approach has shown that the insulin receptor, insulin receptor substrate 1 (IRS1), protein kinase B (PKB) and insulin-sensitive glucose transporter (GLUT4) are expressed in the sensory epithelium of the human saccule, which also exhibits expression of a calcium-sensitive cAMP/cGMP phosphodiesterase 1C (PDE1C) and the vasopressin type 2 receptor. IRS1 and PDE1C are selectively expressed in sensory epithelial hair cells, whereas the other components are expressed in sensory epithelial supporting cells or in both cell types, as judged from co-expression or non-co-expression with glial fibrillary acidic protein, a marker for supporting cells. Furthermore, IRS1 appears to be localized in association with sensory nerves, whereas GLUT4 is expressed in the peri-nuclear area of stromal cells, as is the case for aquaporin 2. Thus, the insulin receptor, insulin signalling components and selected cAMP signalling components are expressed in the human saccule. In addition to well-known mechanisms of diabetes complications, such as neuropathy and vascular lesions, the expression of these proteins in the saccule could have a role in the observed link between diabetes and balance/hearing disorders.
  •  
25.
  • Dircksen, Heinrich, 1954-, et al. (författare)
  • Crustacean Cardioactive Peptide-immunoreactive neurons innervating brain neuropils, retrocerebral complex and stomatogastric nervous-system of the locust, Locusta migratoria
  • 1995
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 279, s. 495-515
  • Tidskriftsartikel (refereegranskat)abstract
    • The distribution and morphology of crustacean cardioactive peptide-immunoreactive neurons in the brain of the locust Locusta migratoria has been determined. Of more than 500 immunoreactive neurons in total, about 380 are interneurons in the optic lobes. These neurons invade several layers of the medulla and distal parts of the lobula. In addition, a small group of neurons projects into the accessory medulla, the lamina, and to several areas in the median protocerebrum. In the midbrain, 12 groups or individual neurons have been reconstructed. Four groups innervate areas of the superior lateral and ventral lateral protocerebrum and the lateral horn. Two cell groups have bilateral arborizations anterior and posterior to the central body or in the superior median protocerebrum. Ramifications in subunits of the central body and in the lateral and the median accessory lobes arise from four additional cell groups. Two local interneurons innervate the antennal lobe. A tritocerebral cell projects contralaterally into the frontal ganglion and appears to give rise to fibers in the recurrent nerve, and in the hypocerebral and ingluvial ganglia. Varicose fibers in the nervi corporis cardiaci III and the corpora cardiaca, and terminals on pharyngeal dilator muscles arise from two subesophageal neurons. Some of the locust neurons closely resemble immunopositive neurons in a beetle and a moth. Our results suggest that the peptide may be (1) a modulatory substance produced by many brain interneurons, and (2) a neurohormone released from subesophageal neurosecretory cells.
  •  
26.
  • Dircksen, Heinrich, 1954-, et al. (författare)
  • Crustacean cardioactive peptide in the nervous system of the locust, Locusta migratoria: an immunocytochemical study on the ventral nerve cord and peripheral innervation
  • 1991
  • Ingår i: Cell and Tissue Research. - Heidelberg New York : Springer. - 0302-766X .- 1432-0878. ; 263, s. 439-457
  • Tidskriftsartikel (refereegranskat)abstract
    • Crustacean cardioactive peptide-immunoreactive neurons occur in the entire central nervous system of Locusta migratoria. The present paper focuses on mapping studies in the ventral nerve cord and on peripheral projection sites. Two types of contralaterally projecting neurons occur in all neuromers from the subesophageal to the seventh abdominal ganglia. One type forms terminals at the surface of the thoracic nerves 6 and 1, the distal perisympathetic organs, the lateral heart nerves, and on ventral and dorsal diaphragm muscles. Two large neurons in the anterior part and several neurons of a different type in the posterior part of the terminal ganglion project into the last tergal nerves. In the abdominal neuromers 1–7, two types of ipsilaterally projecting neurons occur, one of which gives rise to neurosecretory terminals in the distal perisympathetic organs, in peripheral areas of the transverse, stigmata and lateral heart nerves. Four subesophageal neurons have putative terminals in the neurilemma of the nervus corporis allati II, and in the corpora allata and cardiaca. In addition, several immunoreactive putative interneurons and other neurons were mapped in the ventral nerve cord. A new in situ whole-mount technique was essential for elucidation of the peripheral pathways and targets of the identified neurons, which suggest a role of the peptide in the control of heartbeat, abdominal ventilatory and visceral muscle activity.
  •  
27.
  • Dircksen, Heinrich, 1954- (författare)
  • Fine structure of the neurohemal sinus gland of the shore crab, Carcinus maenas, and immuno-electron-microscopic identification of neurosecretory endings according to their neuropeptide contents
  • 1992
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 269:2, s. 249-266
  • Tidskriftsartikel (refereegranskat)abstract
    • The sinus gland of the shore crab, Carcinus maenas, is a compact assembly of interdigitating neurosecretory axon endings abutting upon the thin basal lamina of a central hemolymph lacuna. Four types of axon endings are distinguishable by the size distribution, shape, electron density and core structure of their neurosecretory granules. One additional type of axon ending is characterized by electron-lucent vacuoles and vesicles. The axon profiles are surrounded by astrocyte-like glial cells. Various fixations followed by epoxy- or Lowicryl-embedding were compared in order to optimize the preservation of the fine structure of the granule types and the antigenicity of their peptide hormone contents. By use of specific rabbit antisera, the crustacean hyperglycemic, molt-inhibiting, pigment-dispersing, and red-pigment-concentrating hormones were assigned to the four distinct granule types which showed no overlap of immunostaining. Epi-polarization microscopy and ultrathin section analysis of immunogold-stained Lowicryl-embedded specimens revealed that immunoreactivity to Leu-enkephalin and proctolin is co-localized with molt-inhibiting hormone immunoreactivity in the same type of granule. The size and core structure of the immunocytochemically identified granule types vary little with the different pretreatments but, in some cases, to a statistically significant extent. The present results are compared with those from earlier studies of sinus glands in different crustaceans. The methods of granule identification used in this study supplement the classical approach in granule typing; they are easier to perform and more reliable for the analysis of release phenomena in identified secretory neurons supplying the neurohemal sinus gland.
  •  
28.
  • Dircksen, Heinrich, 1954-, et al. (författare)
  • Immunocytochemical demonstration of the neurosecretory systems containing putative moult-inhibiting hormone and hyperglycemic hormone in the eyestalk of brachyuran crustaceans
  • 1988
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 251, s. 3-12
  • Tidskriftsartikel (refereegranskat)abstract
    • By use of antisera raised against purified moultinhibiting (MIH) and crustacean hyperglycemic hormone (CHH) from Carcinus maenas, complete and distinct neurosecretory pathways for both hormones were demonstrated with the PAP and immunofluorescence technique. By double staining, employing a combination of silver-enhanced immunogold labelling and PAP, both antigens could be visualized in the same section. Immunoreactive structures were studied in Carcinus maenas, Liocarcinus puber, Cancer pagurus, Uca pugilator and Maja squinado. They were only observed in the X-organ sinus gland (SG) system of the eyestalks and consisted of MIH-positive perikarya, which were dispersed among the more numerous CHH-positive perikarya of the medulla terminalis X-organ (XO). The MIH-positive neurons form branching collateral plexuses adjacent to the XO and axons that are arranged around the CHH-positive central axon bundle of the principal XO-SG tract. In the SG, MIH-positive axon profiles and terminals, clustered around hemolymph lacunae, are distributed between the more abundant CHH-positive axon profiles and terminals. Colocalisation of MIH and CHH was never observed. The gross morphology of both neurosecretory systems was similar in all species examined, however, in U. pugilator and M. squinado immunostaining for MIH was relatively faint unless higher concentrations of antiserum were used. Possible reasons for this phenomenon as well as observed moult cycle-related differences in immunostaining are discussed.
  •  
29.
  • Dircksen, Heinrich, 1954-, et al. (författare)
  • Immunocytochemical localization of CCAP, a novel crustacean cardioactive peptide, in the nervous system of the shore crab, Carcinus maenas L.
  • 1988
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 254:2, s. 347-360
  • Tidskriftsartikel (refereegranskat)abstract
    • Polyclonal antibodies were raised in rabbits against synthetic crustacean cardioactive peptide (CCAP) conjugated to bovine thyroglobulin, and were used to map CCAP-immunoreactive structures in the central nervous system of Carcinus maenas. As expected, the neurohemal pericardial organs (PO) displayed abundant immunoreactivity in nerve fibers and terminals. In addition, immunoreactive neurons were demonstrated in other parts of the nervous system. At least some of them do not appear to terminate in neurohemal structures and may have a non-endocrine, as yet unknown function. Immunoreactive perikarya with a diameter of 25–30 m occur in the brain. They project into the optic and antennary neuropil, and into the eyestalk. One cell was found in the medulla terminalis of the eyestalk and in the connective ganglion, respectively. From the latter, axonal branches could be traced into the brain and the thoracic ganglia (TG). In the TG, small-diameter perikarya give rise to extensive networks of varicose fibers. Some of the perikarya occur in a characteristic paired arrangement with larger CCAP-immunoreactive somata (diameter 40–50 m). These pairs of one small and one large cell occur in all mouthpart and leg segments of the TG, except the abdominal ganglia (AG), where only large cells were found. The main projections of the large neurons comprise one or more fibers in each of the seven segmental nerves (SN), leading to neurosecretory terminals in the PO. The fibers in the SN are joined by branches of an ascending axonal tract from the large perikarya in the AG. The large-type perikarya are considered to be the principal source of CCAP in the PO. The optic ganglia in the eyestalk, except the medulla terminalis, the neurohemal sinus gland and the stomatogastric nervous system are devoid of CCAP-immunoreactivity.In axon terminals of the PO, CCAP is not colocalized with other PO-neuropeptides, i.e. proctolin-, FMRFamide-like, and Leu-enkephalin-like immunoreactive materials. Electron-microscopic immunocytochemistry revealed a distinct CCAP-containing granule type in specific axon profiles and terminals in the PO.The architecture of CCAP-immunoreactive neurons is discussed with respect to previous morphological studies on the origin and pathways of fibers terminating in the PO.
  •  
30.
  • Dircksen, Heinrich, 1954-, et al. (författare)
  • The ultrastructure of nerve endings containing pigment-dispersing hormone (PDH) in crustacean sinus glands: Identification by an antiserum against a synthetic PDH
  • 1987
  • Ingår i: Cell and Tissue Research. - : Springer. - 0302-766X .- 1432-0878. ; 250:2, s. 377-387
  • Tidskriftsartikel (refereegranskat)abstract
    • A high-liter antiserum has been obtained from two rabbits immunized with a glutaraldehyde conjugate of synthetic pigment-dispersing hormone (PDH) from Uca pugilator and bovine thyroglobulin. The antiserum blocked melanophore-dispersing activity of the peptide in vivo. In sinus glands (SG) of Carcinus maenas, Cancer pagurus, Uca pugilator and Orconectes limosus, electron-microscopic immunocytochemistry revealed sparsely distributed axon endings containing a distinct PDH-immunoreactive type of neurosecretory granules (diameter 90–130 nm). Exocytotic figures indicating release of the content of these granules into hemolymph lacunae were occasionally observed. Preservation of fine structure and antigenicity of the PDH granules were markedly dependent on the fixation procedure used. A preliminary experiment with C. maenas showed that preterminal axon dilatations near the basal lamina seemed to accumulate PDH-granules when animals were kept in complete darkness for three days. Immunodot blotting of fractions after high pressure liquid chromatography (HPLC) of extracts from SGs of C. maenas and O. limosus revealed a strongly immunoreactive substance at a retention time very similar to those of synthetic PDHs of Uca pugilator and Pandalus borealis. It is also coincident with a zone of biological activity. Thus, the antigen demonstrated by immunocytochemistry is identical or very similar to one of the known PDHs.
  •  
31.
  • Durbeej-Hjalt, Madeleine (författare)
  • Laminins.
  • 2010
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 339, s. 259-268
  • Tidskriftsartikel (refereegranskat)abstract
    • Laminins are cell adhesion molecules that comprise a family of glycoproteins found predominantly in basement membranes, which are the thin sheets of extracellular matrix that underlie epithelial and endothelial cells and surround muscle cells, Schwann cells, and fat cells. Many laminins self-assemble to form networks that remain in close association with cells through interactions with cell surface receptors. Laminins are vital for many physiological functions. They are essential for early embryonic development and organogenesis and have crucial functions in several tissues including muscle, nerve, skin, kidney, lung, and the vasculature. A great wealth of data on laminins is available, and an in-depth description is not attempted here. In this review, I will instead provide a snapshot of laminin structure, tissue distribution, and interactions with other matrix molecules and receptors and briefly describe laminin mutations in mice and humans. Several illuminating and timely reviews are cited that can be consulted for references to original articles and more detailed information concerning laminins.
  •  
32.
  • Eckhard, Andreas, et al. (författare)
  • Co-localisation of Kir4.1 and AQP4 in rat and human cochleae reveals a gap in water channel expression at the transduction sites of endocochlear K+ recycling routes
  • 2012
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 350:1, s. 27-43
  • Tidskriftsartikel (refereegranskat)abstract
    • Sensory transduction in the cochlea depends on perilymphatic-endolymphatic potassium (K+) recycling. It has been suggested that the epithelial supporting cells (SCs) of the cochlear duct may form the intracellular K+ recycling pathway. Thus, they must be endowed with molecular mechanisms that facilitate K+ uptake and release, along with concomitant osmotically driven water movements. As yet, no molecules have been described that would allow for volume-equilibrated transepithelial K+ fluxes across the SCs. This study describes the subcellular co-localisation of the Kir4.1 K+ channel (Kir4.1) and the aquaporin-4 water channel (AQP4) in SCs, on the basis of immunohistochemical double-labelling experiments in rat and human cochleae. The results of this study reveal the expression of Kir4.1 in the basal or basolateral membranes of the SCs in the sensory domain of the organ of Corti that are adjacent to hair cells and in the non-sensory domains of the inner and outer sulci that abut large extracellular fluid spaces. The SCs of the inner sulcus (interdental cells, inner sulcus cells) and the outer sulcus (Hensen’s cells, outer sulcus cells) display the co-localisation of Kir4.1 and AQP4 expression. However, the SCs in the sensory domain of the organ of Corti reveal a gap in the expression of AQP4. The outer pillar cell is devoid of both Kir4.1 and AQP4. The subcellular co-localisation of Kir4.1 and AQP4 in the SCs of the cochlea described in this study resembles that of the astroglia of the central nervous system and the glial Mueller cells in the retina.
  •  
33.
  • Edman, Anne-Christine, et al. (författare)
  • Structural diversity in muscle fibres of chicken breast
  • 1988
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 251:2, s. 281-289
  • Tidskriftsartikel (refereegranskat)abstract
    • hicken breast muscle is usually considered to be a relatively homogeneous white muscle and has therefore been widely used for studies of muscle proteins. In a previous study, however, we have found different M-region structures in different fibres from this muscle. Because of this result, we have now carried out a combined histochemical and ultrastructural survey of this muscle. In particular, we have made use of large transverse cryo-sections that include most of the muscle cross-section. Although the white region is fairly homogeneous in fibre content according to normal histochemical criteria (mATPase), we have found that there is a gradation of fibre structure across the muscle. The bulk of the muscle stains conventionally for Type-II fibres according to mATPase tests (the "white" part) but, in the small "red" part of the muscle, there are also Type-I fibres together with the Type-II fibres. Superimposed on this division into Type-I and Type-II fibres are variations in fibre size, oxidative and glycolytic staining properties, and variations of Z-band width and M-band structure; there is no strict correlation among any of these parameters. The apparently uniform staining across most of the muscle when tested for myofibrillar ATPase may be a misleading indicator of fibre properties.
  •  
34.
  • Edoff, Karin, 1973-, et al. (författare)
  • Retrograde tracing and neuropeptide immunohistochemistry of sensory neurones projecting to the cartilaginous distal femoral epiphysis of young rats
  • 2000
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 299:2, s. 193-200
  • Tidskriftsartikel (refereegranskat)abstract
    • Although cartilage is considered to be devoid of innervation, axons occur in the perichondrium and during development in cartilage canals, thereby having a relatively close spatial relationship to chondroblasts and chondrocytes. The present study locates the source of the sensory innervation of the femoral cartilaginous epiphyses of young rats and investigates whether the neuropeptide calcitonin gene-related peptide (CGRP) can influence chondrocytes. Retrograde tracing from the distal femoral epiphysis of young rats with Fast Blue (FB) showed labelled neuronal profiles in the L2-L5 dorsal root ganglia. Sample countings indicated that 50% of the FB-labelled neuronal profiles were located at the L3 level and 25% at the L4 level. The labelled neurones had diameters of 15-40 µm, with a peak at 25-30 µm. Immunohistochemistry showed that about 50% of the FB-labelled profiles contained CGRP. Together with the finding that CGRP influences bone cells to generate the second messenger cAMP, this result suggested the hypothesis that chondrocytes might be similarly influenced by CGRP. However, stimulation of cartilage slices with CGRP in vitro followed by an assay of the cAMP content did not provide support for this hypothesis. We conclude that primary sensory neurones containing CGRP project to the perichondrium and to cartilage canals of growing cartilage, and that exogenous CGRP does not elevate the cAMP content of cartilage slices in vitro.
  •  
35.
  • Ekström, Peter, et al. (författare)
  • Immunohistochemical evidence for multiple photosystems in box jellyfish.
  • 2008
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 333:1, s. 115-124
  • Tidskriftsartikel (refereegranskat)abstract
    • Cubomedusae (box jellyfish) possess a remarkable visual system with 24 eyes distributed in four sensory structures termed rhopalia. Each rhopalium is equipped with six eyes: two pairs of pigment cup eyes and two unpaired lens eyes. Each eye type probably captures specific features of the visual environment. To investigate whether multiple types of photoreceptor cells are present in the rhopalium, and whether the different eye types possess different types of photoreceptors, we have used immunohistochemistry with a range of vertebrate opsin antibodies to label the photoreceptors, and electroretinograms (ERG) to determine their spectral sensitivity. All photoreceptor cells of the two lens eyes of the box jellyfish Tripedalia cystophora and Carybdea marsupialis displayed immunoreactivity for an antibody directed against the zebrafish ultraviolet (UV) opsin, but not against any of eight other rhodopsin or cone opsin antibodies tested. In neither of the two species were the pigment cup eyes immunoreactive for any of the opsin antibodies. ERG analysis of the Carybdea lower lens eyes demonstrated a single spectral sensitivity maximum at 485 nm suggesting the presence of a single opsin type. Our data demonstrate that the lens eyes of box jellyfish utilize a single opsin and are thus color-blind, and that there is probably a different photopigment in the pigment cup eyes. The results support our hypothesis that the lens eyes and the pigment cup eyes of box jellyfish are involved in different and specific visual tasks.
  •  
36.
  • Elofsson, Rolf (författare)
  • 5-HT-like immunoreactivity in the central nervous system of the crayfish Pacifastacus leniusculus
  • 1983
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 232, s. 221-236
  • Tidskriftsartikel (refereegranskat)abstract
    • An immunocytochemical technique with the use of three different antibodies raised against serotonin was applied to localize the immunoreactive neurons in the central nervous system of the crayfish, Pacifastacus leniusculus. Immunoreactive neurons were found in three optic ganglia (medulla externa, interna and terminalis). They appeared in three layers of the medulla externa and interna. The medulla terminalis displayed three prominent groups of immunoreactive perikarya and mainly marginal immunoreactive fibres. Immunoreactive areas of the brain comprised the protocerebral bridge, central body, paracentral lobes and two loci in the anterior portion of the protocerebrum, i.e., the terminal areas for immunoreactive fibres from the optic centres. The olfactory lobes showed a specific immunoreactive pattern. In addition, diffusely and sparsely distributed immunoreactive fibres were found throughout the brain. The immunoreactive neurons are largely localized in the same areas of the central nervous system as the catecholaminergic neurons although some distinct differences occur.
  •  
37.
  • Elofsson, Rolf, et al. (författare)
  • A catecholaminergic neuron connecting the first two optic neuropiles (lamina ganglionaris and medulla externa) of the crayfish Pacifastacus leniusculus
  • 1977
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 182, s. 287-297
  • Tidskriftsartikel (refereegranskat)abstract
    • The crustacean optic neuropiles, the lamina ganglionaris and especially the medulla externa, show a specific pattern of green fluorescence with the fluorescence histochemical method of Falck-Hillarp. Normally, only the terminals and the cell bodies fluoresce, but in reserpine-treated animals exogenous catecholamines are taken up by the whole adrenergic neuron and are thus visualized as a whole. Incubating crayfish optic neuropiles in dopamine or α-methylnoradrenaline after reserpine treatment demonstrated a tangential neuron connecting the lamina and the medulla externa. The morphology of this tangential neuron differs from the two types of tangential neurons, Tan1 and Tan2, previously characterized with Golgi techniques. The catecholaminergic neuron thus constitutes a third tangential neuron type.
  •  
38.
  • Elofsson, Rolf, et al. (författare)
  • Catecholaminergic innervation of muscles in the hindgut of crustaceans
  • 1978
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 189, s. 257-266
  • Tidskriftsartikel (refereegranskat)abstract
    • The crustacean species Pacifastacus leniusculus and Gammarus pulex were investigated by electron microscopy in a search for possible neuromuscular junctions in the hindgut, which has a rich supply of catecholaminergic fibres. True neuromuscular synapses were found in both species between nerve terminals containing dense-core vesicles (80–110 nm in diam.) and muscle fibres. We suggest that the dense-core vesicle terminals contain a catecholamine, and this is supported by ultrahistochemical tests for monoamines. Two types of junctions are found: one in which the nerve terminal is embedded in the muscle cell (both species) and one in which protrusions from the muscle cell meet nerve terminals (Pacifastacus). Gammarus pulex, which has only circular muscles in the hindgut, has only catecholaminergic innervation, whereas Pacifastacus leniusculus has circular and longitudinal muscles both with at least two types of innervation.
  •  
39.
  • Elofsson, Rolf, et al. (författare)
  • Evidence for new catecholamines or related amino acids in some invertebrate neurons
  • 1977
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 182, s. 525-536
  • Tidskriftsartikel (refereegranskat)abstract
    • In certain sensory neurons of many different invertebrate species, including the sea anemones. Metridium senile and Tealia felina and the crustacean Anemia salina, fluorophores are formed during the course of the fluorescent histochemical technique of Falck-Hillarp. The presumed catecholamine nature of the neuronal fluorogenic compound was investigated by microspectrofluorometry, and the spectral characteristics of the fluorescence in the taxonomically different species was found to be very similar (excitation maximum at 375 nm with a smaller peak or shoulder at 330 nm and sometimes a shoulder in the spectrum at 410 nm; emission maximum at 475 nm). The emission maximum coincides with that of the catecholamines and DOPA (475 nm). The excitation maximum (375 nm) directly after formaldehyde treatment, however, differs from that of the catecholamines and DOPA (410 nm), but is similar to the excitation maximum displayed by these catechol derivatives at acid pH. The spectral characteristics of the fluorophore in the sensory cells might therefore theoretically be explained by an acid pH in the cells. This seems improbable, however, and it is suggested that the phenomenon is due to the presence of unknown catechol derivatives. Analyses of the pH-dependent spectral changes indicate that the presumed catechol derivative in Tealia felina is β-hydroxylated, whereas that in Anemia salina is not.
  •  
40.
  • Elofsson, Rolf, et al. (författare)
  • Gland cells in the tentacles of the jellyfish Cyanea lamarcki reactive with an antibody against 5-hydroxytryptamine.
  • 1989
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 255, s. 419-422
  • Tidskriftsartikel (refereegranskat)abstract
    • A light- and electron-microscopic immunocytochemical study on the localization of 5-hydroxytryptamine in Cyanea lamarcki revealed a reaction product in the epidermal gland cells surrounding the nematocyst clusters. The closely related scyphozoan medusa Cyanea capillata lacked a reaction product in the similar mucus-producing gland cells. Earlier conflicting views on the presence and localization of 5-hydroxytryptamine in coelenterates can thus be due to large species differences. It can be stated that 5-hydroxytryptamine is lacking in the venom of Cyanea.
  •  
41.
  • Erjefält, Jonas, et al. (författare)
  • In vivo restitution of airway epithelium
  • 1995
  • Ingår i: Cell and Tissue Research. - 1432-0878. ; 281:2, s. 305-316
  • Tidskriftsartikel (refereegranskat)abstract
    • Epithelial shedding occurs in health and, extensively, in inflammatory airway diseases. This study describes deepithelialisation, reepithelialisation and associated events in guinea-pig trachea after shedding-like epithelial denudation in vivo. Mechanical deepithelialisation of an 800-microns wide tracheal zone was carried out using an orotracheal steel probe without bleeding or damage to the basement membrane. Reepithelialisation was studied by scanning- and transmission electron microscopy and light microscopy. Nerve fibres were examined by immunostaining. Cell proliferation was analysed by [3H]-thymidine autoradiography. Immediately after epithelial removal secretory and ciliated (and presumably basal) epithelial cells at the wound margin dedifferentiated, flattened and migrated rapidly (2-3 microns/min) over the denuded basement membrane. Within 8-15 h a new, flattened epithelium covered the entire deepithelialised zone. At 30 h a tight epithelial barrier was established and after 5 days the epithelium was fully redifferentiated. After completed migration an increased mitotic activity occurred in the epithelium and in fibroblasts/smooth muscle beneath the restitution zone. Reinnervating intraepithelial calcitonin gene-related peptide-containing nerve fibres appeared within 30 h. We conclude that (1) reproducible shedding-like denudation, without bleeding or damage to the basement membrane, can be produced in vivo; (2) secretory and ciliated cells participate in reepithelialisation by dedifferentiation and migration; (3) the initial migration is very fast in vivo; (4) shedding-like denudation may cause strong secretory and exudative responses as well as proliferation of epithelium, and fibroblasts/smooth muscle. Rapid restitution of airway epithelium may depend on contributions from the microcirculation and innervation.
  •  
42.
  • Ferreiro, Maria Eugenia, et al. (författare)
  • Unraveling the effect of the inflammatory microenvironment in spermatogenesis progression
  • 2023
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 392:2, s. 581-604
  • Tidskriftsartikel (refereegranskat)abstract
    • Experimental autoimmune orchitis (EAO) is a chronic inflammatory disorder that causes progressive spermatogenic impairment. EAO is characterized by high intratesticular levels of nitric oxide (NO) and tumor necrosis factor alpha (TNFα) causing germ cell apoptosis and Sertoli cell dysfunction. However, the impact of this inflammatory milieu on the spermatogenic wave is unknown. Therefore, we studied the effect of inflammation on spermatogonia and preleptotene spermatocyte cell cycle progression in an EAO context and through the intratesticular DETA-NO and TNFα injection in the normal rat testes. In EAO, premeiotic germ cell proliferation is limited as a consequence of the undifferentiated spermatogonia (CD9+) cell cycle arrest in G2/M and the reduced number of differentiated spermatogonia (c-kit+) and preleptotene spermatocytes that enter in the meiotic S-phase. Although inflammation disrupts spermatogenesis in EAO, it is maintained in some seminiferous tubules at XIV and VII–VIII stages of the epithelial cell cycle, thereby guaranteeing sperm production. We found that DETA-NO (2 mM) injected in normal testes arrests spermatogonia and preleptotene spermatocyte cell cycle; this effect reduces the number of proliferative spermatogonia and the number of preleptotene spermatocytes in meiosis S-phase (36 h after). The temporal inhibition of spermatogonia clonal amplification delayed progression of the spermatogenic wave (5 days after) finally altering spermatogenesis. TNFα (0.5 and 1 µg) exposure did not affect premeiotic germ cell cycle or spermatogenic wave. Our results show that in EAO the inflammatory microenvironment altered spermatogenesis kinetics through premeiotic germ cell cycle arrest and that NO is a sufficient factor contributing to this phenomenon.
  •  
43.
  • Fong, Gloria, et al. (författare)
  • Human tenocytes are stimulated to proliferate by acetylcholine through an EGFR signalling pathway
  • 2013
  • Ingår i: Cell and Tissue Research. - : Springer-Verlag New York. - 0302-766X .- 1432-0878. ; 351:3, s. 465-475
  • Tidskriftsartikel (refereegranskat)abstract
    • Studies of human patellar and Achilles tendons have shown that primary tendon fibroblasts (tenocytes) not only have the capacity to produce acetylcholine (ACh) but also express muscarinic ACh receptors (mAChRs) through which ACh can exert its effects. In patients with tendinopathy (chronic tendon pain) with tendinosis, the tendon tissue is characterised by hypercellularity and angiogenesis, both of which might be influenced by ACh. In this study, we have tested the hypothesis that ACh increases the proliferation rate of tenocytes through mAChR stimulation and have examined whether this mechanism operates via the extracellular activation of the epidermal growth factor receptor (EGFR), as shown in other fibroblastic cells. By use of primary human tendon cell cultures, we identified cells expressing vimentin, tenomodulin and scleraxis and found that these cells also contained enzymes related to ACh synthesis and release (choline acetyltransferase and vesicular acetylcholine transporter). The cells furthermore expressed mAChRs of several subtypes. Exogenously administered ACh stimulated proliferation and increased the viability of tenocytes in vitro. When the cells were exposed to atropine (an mAChR antagonist) or the EGFR inhibitor AG1478, the proliferative effect of ACh decreased. Western blot revealed increased phosphorylation, after ACh stimulation, for both EGFR and the extracellular-signal-regulated kinases 1 and 2. Given that tenocytes have been shown to produce ACh and express mAChRs, this study provides evidence of a possible autocrine loop that might contribute to the hypercellularity seen in tendinosis tendon tissue.
  •  
44.
  •  
45.
  •  
46.
  • Fridén, Jan, et al. (författare)
  • Implementation of periodic acid-thiosemicarbazide-silver proteinate staining for ultrastructural assessment of muscle glycogen utilization during exercise
  • 1985
  • Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; :242, s. 229-232
  • Tidskriftsartikel (refereegranskat)abstract
    • Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar I-band. After long-term exhaustive exercise type-1 fibers with a few or no glycogen particles in the core of the fibers were frequently observed. The subsarcolemmal glycogen stores of these "depleted" type-1 fibers were about three times as large as after exhaustive short-time exercise. Another indication of utilization of subsarcolemmal glycogen stores during anaerobic exercise was that many particles displayed a pale, rudimentary shape. This observation suggests fragmental metabolization of glycogen. Thus, depending on type of exercise and type of fiber differential and sequential glycogen utilization patterns can be observed
  •  
47.
  • Friis-Hansen, L, et al. (författare)
  • Antral G-cell in gastrin and gastrin-cholecystokinin knockout animals
  • 2005
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 321:1, s. 141-146
  • Tidskriftsartikel (refereegranskat)abstract
    • The antral hormone gastrin is the key regulator of gastric acid secretion, mucosal growth and differentiation. Gastrin is synthesized in the endocrine G-cells in the antroduodenal mucosa. We have now examined the way in which the loss of gastrin alone or gastrin plus cholecystokinin (CCK) affects the antral G-cell. Immunohistochemistry, radioimmunoassay and quantitative real-time polymerase chain reaction techniques were employed to examine the expression of genes belonging to the G-cell secretory pathway in gastrin and gastrin-CCK knockout mice. Transmission electron microscopy was used to examine the ultrastructure of the G-cells. The number of G-cells increased but the secretory granules were few and abnormally small in the G-cells of both mouse models compared with wildtypes. Thus, gastrin is not necessary for the formation of G-cells as such but the lack of gastrin reduces the number and size of their secretory granules suggesting that gastrin is vital for the formation and/or maintenance of secretory granules in G-cells.
  •  
48.
  • Garm, Anders, et al. (författare)
  • Rhopalia are integrated parts of the central nervous system in box jellyfish
  • 2006
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 325:2, s. 333-343
  • Tidskriftsartikel (refereegranskat)abstract
    • In cubomedusae, the central nervous system (CNS) is found both in the bell (the ring nerve) and in the four eye-bearing sensory structures (the rhopalia). The ring nerve and the rhopalia are connected via the rhopalial stalks and examination of the structure of the rhopalial stalks therefore becomes important when trying to comprehend visual processing. In the present study, the rhopalial stalk of the cubomedusae Tripedalia cystophora has been examined by light microscopy, transmission electron microscopy, and electrophysiology. A major part of the ring nerve is shown to continue into the stalk and to contact the rhopalial neuropil directly. Ultrastructural analysis of synapse distribution in the rhopalial stalk has failed to show any clustering, which indicates that integration of the visual input is probably spread throughout the CNS. Together, the results indicate that cubomedusae have one coherent CNS including the rhopalia. Additionally, a novel gastrodermal nerve has been found in the stalk; this nerve is not involved in visual processing but is likely to be mechanosensory and part of a proprioceptory system.
  •  
49.
  • Garm, Anders, et al. (författare)
  • The ring nerve of the box jellyfish Tripedalia cystophora
  • 2007
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 329:1, s. 147-157
  • Tidskriftsartikel (refereegranskat)abstract
    • Box jellyfish have the most elaborate sensory system and behavioural repertoire of all cnidarians. Sensory input largely comes from 24 eyes situated on four club-shaped sensory structures, the rhopalia, and behaviour includes obstacle avoidance, light shaft attractance and mating. To process the sensory input and convert it into the appropriate behaviour, the box jellyfish have a central nervous system (CNS) but this is still poorly understood. The CNS has two major components: the rhopalial nervous system and the ring nerve. The rhopalial nervous system is situated within the rhopalia in close connection with the eyes, whereas the ring nerve encircles the bell. We describe the morphology of the ring nerve of the box jellyfish Tripedalia cystophora as ascertained by normal histological techniques, immunohistochemistry and transmission electron microscopy. By light microscopy, we have estimated the number of cells in the ring nerve by counting their nuclei. In cross sections at the ultrastructural level, the ring nerve appears to have three types of neurites: (1) small "normal"-looking neurites, (2) medium-sized neurites almost completely filled by electron-lucent vacuoles and (3) giant neurites. In general, only one giant neurite is seen on each section; this type displays the most synapses. Epithelial cells divide the ring nerve into compartments, each having a tendency to contain neurites of similar morphology. The number and arrangement of the compartments vary along the length of the ring nerve.
  •  
50.
  • Garvin, Stina, et al. (författare)
  • Estradiol increases VEGF in human breast studied by whole-tissue culture.
  • 2006
  • Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 325:2, s. 245-51
  • Tidskriftsartikel (refereegranskat)abstract
    • Sex steroid exposure constitutes a risk factor for breast cancer, but little is known about the effects of sex steroids on the normal breast, largely because of the lack of convenient models. We have developed a method of culturing normal breast tissue ex vivo. We have applied this method to investigate the effects of estradiol and progesterone on the key angiogenic mediator, vascular endothelial growth factor (VEGF), in the breast. Whole breast tissue was obtained from routine reduction mammoplasty. Tissue biopsies were cultured in vitro for 1-3 weeks, and the expression of luminal cytokeratin 18 was determined by immunohistochemistry. As an application, tissue biopsies were treated in vitro for 1 week with or without estradiol or estradiol and progesterone. Estrogen receptor, progesterone receptor, and Ki-67 were analyzed, and VEGF levels were examined by quantitative immunoassay and immunohistochemistry. Whole breast tissue was cultured ex vivo for 1 week with preserved morphology. Increased detachment of the luminal epithelium was observed after 2 weeks. Estradiol increased extracellular levels of VEGF in normal breast tissue biopsy medium. The addition of progesterone had neither stimulatory nor inhibitory effects on secreted VEGF. The method of whole breast tissue culturing thus provide a means by which to explore the biology of normal breast tissue. Our results suggest that estradiol exerts pro-angiogenic effects in normal breast by increasing levels of biologically active VEGF.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 189
Typ av publikation
tidskriftsartikel (175)
forskningsöversikt (14)
Typ av innehåll
refereegranskat (187)
övrigt vetenskapligt/konstnärligt (2)
Författare/redaktör
Dircksen, Heinrich, ... (20)
Elofsson, Rolf (14)
Rask-Andersen, Helge (12)
Liu, Wei (10)
Olson, L (8)
Sundler, Frank (7)
visa fler...
Glueckert, Rudolf (6)
Schrott-Fischer, Ann ... (5)
Ekblad, Eva (5)
Nässel, Dick R (4)
Qu, Chengjuan, 1967- (4)
Lammi, Mikko, 1961- (4)
Wierup, Nils (3)
Warrant, Eric (3)
STROMBERG, I (3)
Durbeej-Hjalt, Madel ... (3)
Galter, D. (3)
Johansson, O (3)
Olsson, Catharina, 1 ... (3)
Lexell, Jan (3)
Kinnefors, Anders (3)
Håkanson, Rolf (3)
Ekström, Peter (3)
Andersson, K (2)
Salehi, S Albert (2)
Alfredson, Håkan (2)
Dabrosin, Charlotta (2)
Widenfalk, J (2)
Sundell, Kristina, 1 ... (2)
Chen, D (2)
Holmberg, K (2)
Fried, K (2)
Hokfelt, T (2)
Westerlund, M. (2)
Brundin, Patrik (2)
Kannisto, P (2)
Owman, C (2)
Nilsson, Bengt-Olof (2)
Forsgren, Sture (2)
Rippe, Catarina (2)
Hellstrand, Per (2)
Li, Jia-Yi (2)
Hildebrand, Claes, 1 ... (2)
Boström, Marja (2)
Johansson, Kjell (2)
Danielson, Patrik (2)
Lindqvist, E (2)
Kingham, Paul J. (2)
Owman, Christer (2)
Asplund, Maria (2)
visa färre...
Lärosäte
Lunds universitet (55)
Karolinska Institutet (44)
Stockholms universitet (30)
Uppsala universitet (23)
Umeå universitet (15)
Göteborgs universitet (12)
visa fler...
Linköpings universitet (6)
Luleå tekniska universitet (5)
Linnéuniversitetet (4)
Kungliga Tekniska Högskolan (3)
Sveriges Lantbruksuniversitet (3)
Högskolan i Halmstad (1)
Örebro universitet (1)
Gymnastik- och idrottshögskolan (1)
visa färre...
Språk
Engelska (189)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (95)
Medicin och hälsovetenskap (39)
Humaniora (1)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy