| 1. |
- Alsmark, Cecilia M., et al.
(författare)
-
The louse-borne human pathogen Bartonella quintana is a genomic derivative of the zoonotic agent Bartonella henselae
- 2004
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 101:26, s. 9716-9721
-
Tidskriftsartikel (refereegranskat)abstract
- We present the complete genomes of two human pathogens, Bartonella quintana (1,581,384 bp) and Bartonella henselae (1,931,047 bp). The two pathogens maintain several similarities in being transmitted by insect vectors, using mammalian reservoirs, infecting similar cell types (endothelial cells and erythrocytes) and causing vasculoproliferative changes in immunocompromised hosts. A primary difference between the two pathogens is their reservoir ecology. Whereas B. quintana is a specialist, using only the human as a reservoir, B. henselae is more promiscuous and is frequently isolated from both cats and humans. Genome comparison elucidated a high degree of overall similarity with major differences being B. henselae specific genomic islands coding for filamentous hemagglutinin, and evidence of extensive genome reduction in B. quintana, reminiscent of that found in Rickettsia prowazekii. Both genomes are reduced versions of chromosome I from the highly related pathogen Brucella melitensis. Flanked by two rRNA operons is a segment with similarity to genes located on chromosome II of B. melitensis, suggesting that it was acquired by integration of megareplicon DNA in a common ancestor of the two Bartonella species. Comparisons of the vector-host ecology of these organisms suggest that the utilization of host-restricted vectors is associated with accelerated rates of genome degradation and may explain why human pathogens transmitted by specialist vectors are outnumbered by zoonotic agents, which use vectors of broad host ranges.
|
|
| 2. |
- Jansson, E., Grönvik, K.-O., Johannisson, A., Näslund, K. Westergren, E. and Pilström, L
(författare)
-
Monoclonal antibodies to lymphocytes of rainbow trout (Oncorhynchus mykiss)
- 2003
-
Ingår i: Fish & Shellfish Immunology. ; 14, s. 239-257
-
Tidskriftsartikel (refereegranskat)
|
|
| 3. |
|
|
| 4. |
- Ehrström, M, et al.
(författare)
-
Pharmacokinetic profile of orexin A and effects on plasma insulin and glucagon in the rat
- 2004
-
Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115 .- 1873-1686. ; 119:3, s. 209-212
-
Tidskriftsartikel (refereegranskat)abstract
- Orexin A (OXA) is found in the central nervous system (CNS) and in the gut. Peripheral administration of OXA to rats results in an inhibition of fasting motility. Plasma OXA increases during fasting and central administration of OXA increases food intake. The aim of the present study was to assess the pharmacokinetic profile of OXA and the effect of intravenously (IV) administered OXA on plasma concentrations of insulin and glucagon concentrations. Rats were given OXA IV (100 pmol kg-1 min-1) for time periods of 0, 10, 20, 30 min and for 10, 20, 30 min after ceasing a 30-min infusion. After each time period, rats were then sacrificed and blood obtained. OXA was also administered at increasing doses (0, 100, 300 and 500 pmol kg-1 min-1) for 30 min and blood was obtained. Plasma OXA, insulin and glucagon levels were measured using commercially available radioimmunoassay (RIA) kits. The plasma half-life of OXA was 27.1±9.5 min. Stepwise increasing infusion rates of OXA confirmed a linear concentration-time curve and thus first-order kinetics. Its volume of distribution indicated no binding to peripheral tissues. Plasma glucagon decreased during infusion of OXA, while insulin was unaffected. Plasma OXA was raised fourfold after food intake. Thus, OXA has a longer plasma half-life than many other peptides found in the gut. This needs to be taken into account when assessing effects of OXA on biological parameters after peripheral administration.reserved.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Tamas, Ivica, et al.
(författare)
-
50 million years of genomic stasis in endosymbiotic bacteria.
- 2002
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 296:5577, s. 2376-9
-
Tidskriftsartikel (refereegranskat)abstract
- Comparison of two fully sequenced genomes of Buchnera aphidicola, the obligate endosymbionts of aphids, reveals the most extreme genome stability to date: no chromosome rearrangements or gene acquisitions have occurred in the past 50 to 70 million years, despite substantial sequence evolution and the inactivation and loss of individual genes. In contrast, the genomes of their closest free-living relatives, Escherichia coli and Salmonella spp., are more than 2000-fold more labile in content and gene order. The genomic stasis of B. aphidicola, likely attributable to the loss of phages, repeated sequences, and recA, indicates that B. aphidicola is no longer a source of ecological innovation for its hosts.
|
|
