Peliosis hepatis is a vasculoproliferative disorder of the liver with infectious and noninfectious causes. In humans and dogs, Bartonella henselae has been linked to peliosis hepatis. Although domestic cats are the natural reservoir of B. henselae and although peliosis hepatis is common in this species, an association between this condition and infection with B. henselae has never been investigated in cats. In this study, 26 cases of peliosis hepatis in cats were tested for B. henselae infection by nested polymerase chain reaction and immunohistochemistry. The authors failed to detect B. henselae nucleic acid or antigen in any of the affected liver specimens. These findings suggest that, unlike in humans and dogs, peliosis hepatis in cats may not be significantly associated with a B. henselae infection.
"However, as compared to humans, normal or immunosuppressed cats display high rates of sub-clinical infections and remain usually healthy, with only chronic bacteraemia , , . In addition, in cats, B. henselae infection has not yet been associated with bacillary angiomatosis or peliosis , . "
[Show abstract][Hide abstract] ABSTRACT: Bartonella henselae, a zoonotic agent, induces tumors of endothelial cells (ECs), namely bacillary angiomatosis and peliosis in immunosuppressed humans but not in cats. In vitro studies on ECs represent to date the only way to explore the interactions between Bartonella henselae and vascular endothelium. However, no comparative study of the interactions between Bartonella henselae and human (incidental host) ECs vs feline (reservoir host) ECs has been carried out because of the absence of any available feline endothelial cell lines.
To this purpose, we have developed nine feline EC lines which allowed comparing the effects of Bartonella strains on human and feline micro-vascular ECs representative of the infection development sites such as skin, versus macro-vascular ECs, such as umbilical vein.
Our model revealed intrinsic differences between human (Human Skin Microvascular ECs –HSkMEC and Human Umbilical Vein ECs – iHUVEC) and feline ECs susceptibility to Bartonella henselae infection.
While no effect was observed on the feline ECs upon Bartonella henselae infection, the human ones displayed accelerated angiogenesis and wound healing.
Noticeable differences were demonstrated between human micro- and macro-vasculature derived ECs both in terms of pseudo-tube formation and healing. Interestingly, Bartonella henselae effects on human ECs were also elicited by soluble factors.
Neither Bartonella henselae-infected Human Skin Microvascular ECs clinically involved in bacillary angiomatosis, nor feline ECs increased cAMP production, as opposed to HUVEC.
Bartonella henselae could stimulate the activation of Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) in homologous cellular systems and trigger VEGF production by HSkMECs only, but not iHUVEC or any feline ECs tested.
These results may explain the decreased pathogenic potential of Bartonella henselae infection for cats as compared to humans and strongly suggest that an autocrine secretion of VEGF by human skin endothelial cells might induce their growth and ultimately lead to bacillary angiomatosis formation.
PLoS ONE 05/2011; 6(5):e20204. DOI:10.1371/journal.pone.0020204 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We design a continuous, time-varying tracking controller for an
underactuated surface vessel in the presence of uncertainty associated
with the hydrodynamic damping coefficients. A Lyapunov-based approach is
used to ensure that the position/orientation tracking error is
ultimately confined to a ball that can be made arbitrarily small. The
result is achieved via the judicious design of a dynamic oscillator in
conjunction with two state transformations. We also illustrate how the
proposed tracking controller yields the same stability result for the
Control Applications, 2001. (CCA '01). Proceedings of the 2001 IEEE International Conference on; 02/2001
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