Search results for "pathogen"
showing 10 items of 1657 documents
Within-host evolution decreases virulence in an opportunistic bacterial pathogen
2015
Abstract Background Pathogens evolve in a close antagonistic relationship with their hosts. The conventional theory proposes that evolution of virulence is highly dependent on the efficiency of direct host-to-host transmission. Many opportunistic pathogens, however, are not strictly dependent on the hosts due to their ability to reproduce in the free-living environment. Therefore it is likely that conflicting selection pressures for growth and survival outside versus within the host, rather than transmission potential, shape the evolution of virulence in opportunists. We tested the role of within-host selection in evolution of virulence by letting a pathogen Serratia marcescens db11 sequent…
Histopathological progression of hidradenitis suppurativa/acne inversa
2021
It is generally acknowledged that the first morphological change of hidradenitis suppurativa/acne inversa (HS/AI) consists of infundibular plugging of the folliculosebaceous apocrine apparatus, which is followed by acute and chronic inflammation, cysts with sinus formation, and fibrosis. Alternatively, it has been hypothesized that HS/AI is primarily a neutrophilic autoinflammatory disease and that the follicular plugging typical of this disease is secondary to inflammation.To review the sequence of the changes that mark the disease development, we have performed a histopathologic study on the surgical material from a series of axillary and inguinal/perineal cases.The histologic material fr…
Slow Infection due to Lowering the Amount of Intact versus Empty Particles Is a Characteristic Feature of Coxsackievirus B5 Dictated by the Structura…
2019
Enterovirus B species typically cause a rapid cytolytic infection leading to efficient release of progeny viruses. However, they are also capable of persistent infections in tissues, which are suggested to contribute to severe chronic states such as myocardial inflammation and type 1 diabetes. In order to understand the factors contributing to differential infection strategies, we constructed a chimera by combining the capsid proteins from fast-cytolysis-causing echovirus 1 (EV1) with nonstructural proteins from coxsackievirus B5 (CVB5), which shows persistent infection in RD cells. The results showed that the chimera behaved similarly to parental EV1, leading to efficient cytolysis in both…
New therapeutic strategies for treatment of inflammatory bowel disease
2008
Although the precise etiology of inflammatory bowel disease (IBD) still remains unclear, considerable progress has been made in the identification of cytokine-mediated signaling pathways involved in the inflammatory process. Recent data have clearly shown that these pathways induce augmented intestinal T-cell activation and thus resistance to apoptosis, which is a central process in disease pathogenesis, as it impairs mucosal homeostasis. Therefore, novel therapeutic strategies aim at restoring activated effector T-cell susceptibility to apoptosis in the gut, based on a pathophysiological rationale. This development is best exemplified by the emergence of agents that target the TNF pathway,…
Genotypic Analysis of E. coli Strains Isolated from Patients with Cystitis and Pyelonephritis
2012
BACKGROUND: Urinary tract infection is the most common health problem affecting millions of people each year, mainly caused by a large genetically heterogeneous group of Escherichia coli called uropathogenic E. coli This study investigates the genotypic analysis of E. coli strains isolated from patients with cystitis and pyelonephritis. METHODS: During 2008-2009, 90 E. coli strains were analyzed, consisting of 48 isolates causing pyelonephritis in children and 42 isolates causing cystitis. Having identified the strains by standard methods, they were subtyped by pulsed field gel electrophoresis (PFGE) and their corresponding patterns were compared using dendrogram. RESULTS: Sixty five PFGE p…
First record of the alien leech Myzobdella lugubris Leidy, 1851 (Hirudinea, Piscicolidae) in the Palearctic
2018
espanolEn este estudio reportamos la aparicion de la sanguijuela Neartica Myzobdella lugubris en un cuerpo de agua salobre de la reserva natural Riserva Naturale dello Stato “Le Cesine” (Apulia, Italy). Dos especimenes de la especie fueren recolectados en el cuello y las extremidades anteriores de una tortuga de estanque europea Emys orbicularis hellenica en Octubre del 2016. La identificacion de los dos especimenes fue basada en datos morfologicos y de secuenciacion molecular. En su distribucion natural, M. lugubris es conocida por ser huesped y vector de bacterias y virus, de los cuales algunos son patogenos de gravedad en peces. En vista de los posibles efectos nocivos, que ejercen sobre…
MAPK3 deficiency drives autoimmunity via DC arming.
2010
DC are professional APC that instruct T cells during the inflammatory course of EAE. We have previously shown that MAPK3 (Erk1) is important for the induction of T-cell anergy. Our goal was to determine the influence of MAPK3 on the capacity of DC to arm T-cell responses in autoimmunity. We report that DC from Mapk3(-/-) mice have a significantly higher membrane expression of CD86 and MHC-II and--when loaded with the myelin oligodendrocyte glycoprotein--show a superior capacity to prime naive T cells towards an inflammatory phenotype than Mapk3(+/+) DC. Nonetheless and as previously described, Mapk3(-/-) mice were only slightly but not significantly more susceptible to myelin oligodendrocyt…
Animal models of Multiple Sclerosis
2015
Multiple Sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) which involves a complex interaction between immune system and neural cells. Animal modeling has been critical for addressing MS pathogenesis. The three most characterized animal models of MS are (1) the experimental autoimmune/allergic encephalomyelitis (EAE); (2) the virally-induced chronic demyelinating disease, known as Theiler׳s murine encephalomyelitis virus (TMEV) infection and (3) the toxin-induced demyelination. All these models, in a complementary way, have allowed to reach a good knowledge of the pathogenesis of MS. Specifically, EAE is the model which better reflects the autoimmu…
Mouse models for multiple sclerosis: historical facts and future implications.
2011
AbstractMultiple sclerosis (MS) is an inflammatory and demyelinating condition of the CNS, characterized by perivascular infiltrates composed largely of T lymphocytes and macrophages. Although the precise cause remains unknown, numerous avenues of research support the hypothesis that autoimmune mechanisms play a major role in the development of the disease. Pathologically similar lesions to those seen in MS can be induced in laboratory rodents by immunization with CNS-derived antigens. This form of disease induction, broadly termed experimental autoimmune encephalomyelitis, is frequently the starting point in MS research with respect to studying pathogenesis and creating novel treatments. M…
Autoantibody depletion ameliorates disease in murine experimental autoimmune encephalomyelitis.
2013
Much data support a role for central nervous system antigen-specific antibodies in the pathogenesis of multiple sclerosis (MS). The effects of inducing a decrease in (auto)antibody levels on MS or experimental autoimmune encephalomyelitis (EAE) through specific blockade of FcRn, however, remain unexplored. We recently developed engineered antibodies that lower endogenous IgG levels by competing for binding to FcRn. These Abdegs ("antibodies that enhance IgG degradation") can be used to directly assess the effect of decreased antibody levels in inflammatory diseases. In the current study, we show that Abdeg delivery ameliorates disease in an EAE model that is antibody dependent. Abdegs could…