| 55451. |
- Tan, Thuan Tong, et al.
(författare)
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Current progress of adhesins as vaccine candidates for Moraxella catarrhalis
- 2007
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Ingår i: Expert Review of Vaccines. - : Informa UK Limited. - 1744-8395 .- 1476-0584. ; 6:6, s. 949-956
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Forskningsöversikt (refereegranskat)abstract
- Moraxello catorrhalis is an emerging pathogen and all isolates are now considered beta-lactamase producing. Potential further use of vaccines against Streptococcus pneumoniae and nontypeable Haemophilus influenzae means that M. catarrhalis might be thrust further into the limelight. However, a vaccine has not yet been designed. In this review, the progress of M. catarrhalis adhesins as vaccine candidates is discussed with a focus on various candidate antigens that spanned those discovered more than 10 years ago, for example, the ubiquitous surface proteins to newer antigens, such as the Moraxella IgD-binding hemagglutinin.
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| 55452. |
- Tan, Thuan Tong, et al.
(författare)
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Haemophilus influenzae Survival during Complement-Mediated Attacks Is Promoted by Moraxella catarrhalis Outer Membrane Vesicles.
- 2007
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 195:11, s. 1661-1670
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Tidskriftsartikel (refereegranskat)abstract
- Moraxella catarrhalis causes respiratory tract infections in children and in adults with chronic obstructive pulmonary disease. It is often isolated as a copathogen with Haemophilus influenzae. The underlying mechanism for this cohabitation is unclear. Here, in clinical specimens from a patient with M. catarrhalis infection, we document that outer membrane vesicles (OMVs) carrying ubiquitous surface protein (Usp) A1 and UspA2 (hereafter, UspA1/A2) were secreted. Further analyses revealed that OMVs isolated in vitro also contained UspA1/A2, which mediate interactions with, among other proteins, the third component of the complement system (C3). OMVs from M. catarrhalis wild-type clinical strains bound to C3 and counteracted the complement cascade to a larger extent than did OMVs without UspA1/A2. In contrast, UspA1/A2-deficient OMVs were significantly weaker inhibitors of complement-dependent killing of H. influenzae. Thus, our results suggest that a novel strategy exists in which pathogens collaborate to conquer innate immunity and that the M. catarrhalis vaccine candidates UspA1/A2 play a major role in this interaction.
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| 55453. |
- Tan, Thuan Tong
(författare)
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MORAXELLA CATARRHALIS OUTER MEMBRANE PROTEINS AND THEIR INTERACTIONS WITH THE HUMAN HOST
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Moraxella catarrhalis is an airway pathogen whose role in infection has been increasingly recognized in recent years. Most authorities in this field now agree that M. catarrhalis causes significant morbidity and is not just a harmless commensal. The universal prevalence of BRO ?-lactamases in this pathogen is a serious concern. In addition, M. catarrhalis may be further propelled into a more prominent position in the hierarchy of respiratory infectious agents due to the phenomenon of ?non-vaccine type replacement? as a result of the wider usage of vaccines against other pathogens in the same ecological niche, such as Haemophilus influenzae and Streptococcus pneumoniae. There is currently no available vaccine against M. catarrhalis. A detailed analysis of the interactions of this bacterium with the human host is necessary to identify ways to interfere with its colonization and infection. To this end, we have focused on the interactions via three outer membrane proteins, namely UspA1 (ubiquitous surface protein A1), UspA2 and MID (Moraxella catarrhalis IgD binding protein). We found that UspA1 and A2 could bind fibronectin and laminin, and characterized these interactions. We also detailed a novel interaction of UspA1 and A2 with the complement protein C3. The UspA1/A2-dependent C3 binding contributes to its serum resistant phenotype and is a way in which M. catarrhalis combat the innate immunity. Furthermore, we showed that this interaction could contribute to the survival of copathogens. An analysis of naturally acquired serological responses to these two proteins and those of MID showed that the functional domains identified here (fibronectin binding region in UspA1299-452 and UspA2165-318, C3 binding region in UspA2) and those identified in other studies (CEACAM binding region of UspA1, the MID764-913 adhesive domain) evoked significant immune responses. The better understanding of the interactions and the identification of important domains in these three proteins represent significant advances in the quest for a suitable vaccine against M. catarrhalis.
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| 55454. |
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| 55455. |
- Taneera, Jalal
(författare)
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Adult Stem Cell Plasticity, Hype or Hope?
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Several studies have reported that bone marrow (BM)-derived stem cells have the capacity to give rise to cells of different type of tissue; an ability termed stem cell plasticity or transdifferentiation. Controversies exist as to how frequent this phenomenon is, or if it may be explained by alternative mechanisms. Here we have used different mouse models to study the potential plasticity of BM-derived stem cells. In the first two studies aiming at defining how BM transplantation may contribute to generation of pancreatic beta-cells, we first demonstrated that BM cells readily engraft recipient pancreas in normal and diabetic mice. Engrafted cells expressed the hematopoietic marker CD45 (CD45+), but no beta-cell markers, e.g. insulin or transcription factors pdx 1 or Nkx6.1. However, a subset of engrafted BM cells also expressed endothelial markers von Willebrand factor (vWF) and CD31/PECAM. In mice treated with different dosages of the beta-cell toxin streptozotocin (STZ) to induce diabetes, the fraction of CD45+vWF+ cells increased with the STZ dose. This coincided with increased proliferation BrdU+ cells in both vWF+ and insulin+ cells. In a third study evaluating BM plasticity in mouse models of myocardial infarction, we showed that BM-derived stem cells efficiently engraft the infarcted myocardium, without any signs of transdifferentiation. A very small population (0.75%) of the BM-derived cells exhibiting a cardiomyocyte phenotype was observed outside the infarcted myocardium. Further analysis showed that these cells were derived through cell fusion. In summary, this thesis challenges the view that BM-derived stem directly transdifferentiate into cardiomyocytes or pancreatic beta-cells. However, BM cells may stimulate pancreatic ?-cell proliferation indirectly, possibly by adopting an endothelial phenotype. These results underline the importance of thorough studies at the cellular level before initiation of clinical BM transplantation trials.
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| 55456. |
- Tanner, G., et al.
(författare)
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Short wavelength approximation of a boundary integral operator for homogeneous and isotropic elastic bodies
- 2007
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Ingår i: Physical Review E (Statistical, Nonlinear, and Soft Matter Physics). - 1539-3755. ; 75:3, s. 6-6
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Tidskriftsartikel (refereegranskat)abstract
- A short wavelength approximation of a boundary integral operator for two-dimensional isotropic and homogeneous elastic bodies is derived from first principles starting from the Navier-Cauchy equation. Trace formulas for elastodynamics are deduced connecting the eigenfrequency spectrum of an elastic body to the set of periodic rays where mode conversion enters as a dynamical feature.
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| 55457. |
- Tanner, Gregor, et al.
(författare)
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Wave chaos in acoustics and elasticity
- 2007
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Ingår i: Journal of Physics A: Mathematical and Theoretical. - 1751-8113. ; 40, s. 443-509
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Tidskriftsartikel (refereegranskat)
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| 55458. |
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| 55459. |
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| 55460. |
- Tarasevicius, Sarunas, et al.
(författare)
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Intracapsular pressure and elasticity of the hip joint capsule in osteoarthritis
- 2007
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Ingår i: Journal of Arthroplasty. - : Elsevier BV. - 0883-5403. ; 22:4, s. 596-600
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Tidskriftsartikel (refereegranskat)abstract
- We investigated intracapsular pressure and elasticity of the hip joint capsule in osteoarthritis. HOOS hip score, sonography of the hip joint, and radiographic assessment of osteoarthritis were performed in 31 patients before total hip arthroplasty. The intracapsular hydrostatic pressure was measured perioperatively, and 0.9% saline solution was then injected in the hip joint, 1 mL at a time with continuous pressure recording up to 300 mm Hg. The mean radiographic grade of severity of osteoarthritis was 8 (SD, 2.4). The mean hydrostatic intracapsular pressure in 45 degrees of flexion was 2.2 mm Hg (SD, 10.0) in extension, 15.8 mm Hg (SD, 33.0); in inward rotation, 13.7 mm Hg (SD, 26.0); and in outward rotation, 12.1 mm Hg (SD, 24.3). Severe osteoarthritis was associated with lower intracapsular pressure and lower elasticity of the joint capsule.
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