Dual color pH probes made from silica and polystyrene nanoparticles and their performance in cell studies.

Ratiometric green-red fluorescent nanosensors for fluorometrically monitoring pH in the acidic range were designed from 80 nm-sized polystyrene (PS) and silica (SiO) nanoparticles (NPs), red emissive reference dyes, and a green emissive naphthalimide pH probe, analytically and spectroscopically characterized, and compared regarding their sensing performance in aqueous dispersion and in cellular uptake studies. Preparation of these optical probes, which are excitable by 405 nm laser or LED light sources, involved the encapsulation of the pH-inert red-fluorescent dye Nile Red (NR) in the core of self-made carboxylated PSNPs by a simple swelling procedure and the fabrication of rhodamine B (RhB)-stained SiO-NPs from a silane derivative of pH-insensitive RhB. Subsequently, the custom-made naphthalimide pH probe, that utilizes a protonation-controlled photoinduced electron transfer process, was covalently attached to the carboxylic acid groups at the surface of both types of NPs.

Multicolor Polystyrene Nanosensors for the Monitoring of Acidic, Neutral, and Basic pH Values and Cellular Uptake Studies.

A first tricolor fluorescent pH nanosensor is presented, which was rationally designed from biocompatible carboxylated polystyrene nanoparticles and two analyte-responsive molecular fluorophores. Its fabrication involved particle staining with a blue-red-emissive dyad, consisting of a rhodamine moiety responsive to acidic pH values and a pH-inert quinoline fluorophore, followed by the covalent attachment of a fluorescein dye to the particle surface that signals neutral and basic pH values with a green fluorescence. These sensor particles change their fluorescence from blue to red and green, depending on the pH and excitation wavelength, and enable ratiometric pH measurements in the pH range of 3.

Toll-Like Receptor-4 Is Involved in Mediating Intestinal and Extra-Intestinal Inflammation in -Infected Secondary Abiotic IL-10 Mice.

Human infections are emerging worldwide and constitute significant health burdens. We recently showed that the immunopathological sequelae in -infected mice were due to Toll-like receptor (TLR)-4 dependent immune responses induced by bacterial lipooligosaccharide (LOS). Information regarding the molecular mechanisms underlying -host interactions are scarce, however.

Pituitary Adenylate Cyclase-Activating Polypeptide Alleviates Intestinal, Extra-Intestinal and Systemic Inflammatory Responses during Acute -induced Enterocolitis in Mice.

Human infections are emerging, and constitute a significant health burden worldwide. The ubiquitously expressed pituitary adenylate cyclase-activating polypeptide (PACAP) is well-known for its cell-protective and immunomodulatory effects. In our actual intervention study, we used an acute campylobacteriosis model and assessed the potential disease-alleviating effects of exogenous PACAP.

The Host-Specific Intestinal Microbiota Composition Impacts Infection in a Clinical Mouse Model of Campylobacteriosis.

Human -infections are progressively rising globally. However, the molecular mechanisms underlying -host interactions are incompletely understood. In this study, we surveyed the impact of the host-specific intestinal microbiota composition during peroral infection applying an established murine campylobacteriosis model.

Microbiota composition and inflammatory immune responses upon peroral application of the commercial competitive exclusion product Aviguard® to microbiota-depleted wildtype mice.

Non-antibiotic feed additives including competitive exclusion products have been shown effective in reducing pathogen loads including multi-drug resistant strains from the vertebrate gut. In the present study we surveyed the intestinal bacterial colonization properties, potential macroscopic and microscopic inflammatory sequelae and immune responses upon peroral application of the commercial competitive exclusion product Aviguard® to wildtype mice in which the gut microbiota had been depleted by antibiotic pre-treatment. Until four weeks following Aviguard® challenge, bacterial strains abundant in the probiotic suspension stably established within the murine intestines.

Inflammatory Immune Responses and Gut Microbiota Changes Following Infection of IL-10 Mice with Chronic Colitis.

Human infections with the food-borne enteropathogens are progressively rising. Recent evidence revealed that pre-existing intestinal inflammation facilitates enteropathogenic infection subsequently exacerbating the underlying disease. Given that only little is known about -host interactions and particularly during intestinal inflammation, the aim of the present study was to survey gastrointestinal colonization properties, gut microbiota changes and pro-inflammatory sequelae upon peroral -infection of IL-10 mice with chronic colitis.

The conundrum of colonization resistance against Campylobacter reloaded: The gut microbota composition in conventional mice does not prevent from Campylobacter coli infection.

The physiological colonization resistance exerted by the murine gut microbiota prevents conventional mice from Campylobacter jejuni infection. In the present study we addressed whether this also held true for Campylobacter coli. Following peroral application, C.

Immune-modulatory Properties of the Octapeptide NAP in Infected Mice Suffering from Acute Enterocolitis.

Human infections with the food-borne zoonotic pathogen are progressively rising and constitute serious global public health and socioeconomic burdens. Hence, application of compounds with disease-alleviating properties are required to combat campylobacteriosis and post-infectious sequelae. In our preclinical intervention study applying an acute induced enterocolitis model, we surveyed the anti-pathogenic and immune-modulatory effects of the octapeptide NAP which is well-known for its neuroprotective and anti-inflammatory properties.

Toll-Like Receptor-4 Dependent Intestinal and Systemic Sequelae Following Peroral Infection of IL10 Deficient Mice Harboring a Human Gut Microbiota.

Zoonotic , including and , are among the most prevalent agents of food-borne enteritis worldwide. The immunopathological sequelae of campylobacteriosis are caused by Toll-like Receptor-4 (TLR4)-dependent host immune responses, induced by bacterial lipooligosaccharide (LOS). In order to investigate -host interactions, including the roles of the human gut microbiota and TLR4, upon infection, we applied a clinical acute campylobacteriosis model, and subjected secondary abiotic, TLR4-deficient IL10 mice and IL10 controls to fecal microbiota transplantation derived from human donors by gavage, before peroral challenge.

Impairs Sodium Absorption in Colonic Epithelium via ENaC Dysfunction and Claudin-8 Disruption.

The epithelial sodium channel (ENaC) can increase the colonic absorptive capacity for salt and water. is a common pathogenic epsilonproteobacterium, causing enteritis and diarrhea. It can induce barrier dysfunction in the intestine, but its influence on intestinal transport function is still unknown.