| 1. |
- Henson, M.M., et al.
(författare)
-
Smooth muscle in the annulus fibrosus of the tympanic membrane in bats, rodents, insectivores and humans
- 2005
-
Ingår i: Hearing Research. - : Elsevier BV. - 0378-5955 .- 1878-5891. ; 200:1-2, s. 29-37
-
Tidskriftsartikel (refereegranskat)abstract
- The annulus fibrosus and its attachment to the bony tympanic ring were studied in a series of mammals. In the pallid bat, Antrozous pallidus, there is an extensive plexus of large interconnected blood sinuses in the part of the annulus that borders the tympanic bone. The spaces between the sinuses are packed with smooth muscle cells. Most of the cells have a predominately radial orientation; they extend from the bony tympanic sulcus to a dense collagenous matrix (apical zone) where radially oriented fibers of the pars tensa are confluent with the annulus. The muscles and vessels constitute a myovascular zone. A structurally similar myovascular zone is also present in the European hedgehog. In rodents, the annulus lacks the large interconnected blood sinuses but many small vessels are present. Smooth muscle is concentrated in the broad area of attachment of the annulus to the tympanic bone. In the gerbil, smooth muscle seems to be concentrated in the central part of the width of the annulus where it is attached to bone and radiates toward the tympanic membrane. In humans collections of radially oriented smooth muscle cells were found in several locations. The smooth muscle in all species studied appears to form a rim of contractile elements for the pars tensa. This arrangement suggests a role in controlling blood flow and/or creating and maintaining tension on the tympanic membrane.
|
|
| 2. |
- Ellerström, Mats, 1961, et al.
(författare)
-
Ectopic Expression of EFFECTOR OF TRANSCRIPTION Perturbs Gibberellin-Mediated Plant Developmental Processes
- 2005
-
Ingår i: Plant Molecular Biology. - : Springer Science and Business Media LLC. - 0167-4412 .- 1573-5028. ; 59:4, s. 663-681
-
Tidskriftsartikel (refereegranskat)abstract
- The plant hormone gibberellin (GA) is known to modulate various aspects of plant cell differentiation and development. The current model of GA-mediated regulation is based on a de-repressible system and includes specific protein modification and degradation. HRT, a zinc finger protein from barley has been shown to have GA-dependent transcriptional repressing activity on the seed-specific α-amylase promoter [Raventos, D., Skriver, K., Schlein, M., Karnahl, K., Rogers, S.W., Rogers, J.C. and Mundy, J. 1998. J.␣Biol. Chem. 273: 2331323320]. Here we report the characterization of a dicot homologue from Brassica napus (BnET) and provide evidence for its role in GA response modulation suggesting that this could be a conserved feature of this gene family. When BnET is ectopically expressed in either Arabidopsis or tobacco the phenotypes include dwarfism due to shorter internodes and late flowering, reduced germination rate, increased anthocyanin content and reduced xylem lignification as a marker for terminal cell differentiation. Transient expression in protoplasts supports the notion that this most likely is due to a transcriptional repression of GA controlled genes. Finally, histological analysis showed that in contrast to other GA deficient mutants the shorter internodes were due to fewer but not smaller cells, suggesting a function of BnET in GA-mediated cell division control.
|
|
| 3. |
|
|
| 4. |
- Lönnqvist, Anna, 1980, et al.
(författare)
-
Neonatal exposure to staphylococcal superantigen improves induction of oral tolerance in a mouse model of airway allergy.
- 2009
-
Ingår i: European journal of immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 39:2, s. 447-56
-
Tidskriftsartikel (refereegranskat)abstract
- The hygiene hypothesis suggests that lack of microbial stimulation in early infancy may lead to allergy, but it has been difficult to identify particular protective microbial exposures. We have observed that infants colonised in the first week(s) of life with Staphylococcus aureus have lower risk of developing food allergy. As many S. aureus strains produce superantigens with T-cell stimulating properties, we here investigate whether neonatal mucosal exposure to superantigen could influence the capacity to develop oral tolerance and reduce sensitisation and allergy. BALB/c mice were exposed to staphylococcal enterotoxin A (SEA) as neonates and fed with OVA as adults, prior to sensitisation and i.n. OVA challenge. Our results show that SEA pre-treated mice are more efficiently tolerised by OVA feeding, as shown by lower lung-cell infiltration and antigen-specific IgE response in the SEA pre-treated mice, compared with sham-treated mice. This was not due to deletion or anergy of lymphocytes by SEA treatment, because the SEA pre-treated mice that were fed with PBS showed similar inflammatory response as the sham-treated PBS-fed mice. Our results suggest that strong T-cell activation in infancy conditions the mucosal immune system and promotes development of oral tolerance.
|
|
| 5. |
- Rask-Andersen, Anna, et al.
(författare)
-
Asthma among health care professionals
- 2007
-
Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1073-449X .- 1535-4970. ; 175:7, s. 633-634
-
Tidskriftsartikel (refereegranskat)
|
|
| 6. |
- Rask-Andersen, Helge, et al.
(författare)
-
Regeneration of human auditory nerve. In vitro/in video demonstration of neural progenitor cells in adult human and guinea pig spiral ganglion
- 2005
-
Ingår i: Hearing Research. - : Elsevier BV. - 0378-5955 .- 1878-5891. ; 203:1-2, s. 180-191
-
Tidskriftsartikel (refereegranskat)abstract
- Time lapse video recordings of cultured adult human and guinea pig spiral ganglion (hSG and gpSG) show that mitogen responsive progenitor/stem cells develop in the form of spheres that proliferate and differentiate into mature neurons and glia cells. Neurospheres, cultured with EGF and bFGF showed expression of nestin and incorporation of 5'-Bromo-2-deoxyuridine (BrdU). Newly formed BrdU labelled cells were positive for beta-tubulin, and also for GFAP demonstrating that neuronal cells were derived from a dividing population of progenitor cells. Dissociated spheres cultured either with glia cell line-derived neurotrophic factor (GDNF) or brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), induced differentiation of the progenitor cells. Video microscopy showed that neurons develop from subcultured spheres maintained for up to four weeks. Neurons showed fasciculation and migration with a speed of 10-30 microm/h, and some cells had up to 6 mm long neurites coexpressing TrkB and TrkC receptors. Precise dissection suggests that the neurons formed are cochlea-specific. The results suggest that the mammalian auditory nerve has the capability for self-renewal and replacement. Transplantation of progenitor cells together with established means to induce neural differentiation and fiber growth may facilitate strategies for better repair and treatment of auditory neuronal damage.
|
|
| 7. |
|
|
| 8. |
- Schrott-Fischer, A., et al.
(författare)
-
Efferent neurotransmitters in the human cochlea and vestibule
- 2007
-
Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 127:1, s. 13-19
-
Tidskriftsartikel (refereegranskat)abstract
- Conclusion: Current neurotransmission models based on animal studies on the mammalian inner ear not always reflect the situation in human. Rodents and primates show significant differences in characteristics of efferent innervation as well as the distribution of neuroactive substances. Objective: Immunohistochemistry demonstrates the mammalian efferent system as neurochemically complex and diverse: several neuroactive substances may co-exist within the same efferent terminal. Using light and electron microscopic immunohistochemistry, this study presents a comparative overview of the distribution patterns of choline acetyltransferase (ChAT), the acetylcholine synthesizing enzyme, GABA, CGRP, and enkephalins within the peripheral nerve fiber systems of the human inner ear. Materials and methods: Human temporal bones were obtained post mortem and prepared according to a pre-embedding immunohistochemical technique to detect immunoreactivities to ChAT, GABA, CGRP, leu- and met-enkephalins at the electron microscopic level. Results: Immunoreactivities of all the antigens were present within both the lateral and medial efferent systems of the cochlea, whereas only ChAT, GABA, and CGRP were detected in efferent pathways of the vestibular end organs.
|
|
| 9. |
- Östman, Sofia M, 1974, et al.
(författare)
-
Impaired regulatory T cell function in germ-free mice.
- 2006
-
Ingår i: European journal of immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 36:9, s. 2336-46
-
Tidskriftsartikel (refereegranskat)abstract
- Regulatory T cells (Treg) are crucial for the maintenance of tolerance to auto-antigens and harmless exogenous antigens. Here, we studied the role of the commensal microbiota for the development and function of Treg. CD4+CD25+ T cells were obtained from peripheral lymph nodes (PLN) and mesenteric lymph nodes (MLN) of germ-free (GF) and conventional (conv) NMRI mice and tested for phenotype and functional suppressive capacity. CD4+CD25+ T cells from GF mice showed a lower relative gene expression of fork head box p3 gene (Foxp3) and were not as potent suppressors in vitro as CD4+CD25+ T cells from conv animals. Intracellular staining for Foxp3 and CTLA-4 revealed proportional and regional differences in putative Treg subsets between conv and GF mice. Fewer of the CD4+CD25+ T cells in GF MLN expressed Foxp3 and CTLA-4, while the expression of these markers was similar amongst the CD4+CD25+ T cells in PLN of conv and GF mice. The largest difference between conv and GF Treg was observed in the liver draining celiac lymph node, where GF mice had fewer putative Treg as compared to conv mice. We propose that the presence of a microbial flora favors the development of a fully functional Treg population.
|
|
