Bacteria clustering by polymers induces the expression of quorum sense controlled phenotypes

Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environment. Quorum sensing is one mean by which bacteria use chemical reactions to modulate pre-infection behaviour such as surface attachment. Polymers that can interfere with bacterial adhesion or the chemical reactions used for quorum sensing are thus a potential means to control bacterial population responses. Here we report how polymeric "bacteria sequestrants", designed to bind to bacteria through electrostatic interactions and thus inhibit bacterial adhesion to surfaces, induce the expression of quorum sensing controlled phenotypes as a consequence of cell clustering. A combination of polymer and analytical chemistry, biological assays and computational modelling has been used to characterise the feedback between bacteria clustering and quorum sensing signaling. We have also derived design principles and chemical strategies for controlling bacterial behaviour at the population leve

Evaluation of the anti-inflammatory effect of erythromycin on aseptic inflammation of temporomandibular joint in rabbit: a scintigraphic and histopathologic study

This article investigates the anti-inflammatory effects of erythromycin (EM) on aseptic inflammation of temporomandibular joint (TMJ) space using by Tc-99 m HIG scintigraphy and histopathology. In this experimental study, 33 adult male New Zealand White rabbits were divided into three groups. The animals in the first group were treated with EM 25 mg kg(-1); the animals in the second group were treated with methylprednisolone (MP) 2 mg kg(-1) and the animals in the third group were given saline solution (control group). Each drug was given by intraperitoneal injection twice a day for 7 days. Two hours after the last injection, carrageenan was injected into right TMJ of rabbits for aseptic inflammation. After carrageenan injection, each rabbit was given an intravenous injection of 111 Mbq (3 mCi) Tc-99 m human HIG, and scanning was performed 4 h later. Later, all animals were killed and TMJ and periarticular tissues were resected. Histopathologically, the distance between synovial surface epithelium (SSE) and muscle layer (ML) in each section was measured by using SAMBA 200 Cell image processor with software. Scintigraphically, when lesion activity/adjacent region activity (L/N) was evaluated there was a significant difference between the control group and the other two groups (P < 0.05 for EM and MP). However, no significant difference was found between the EM and MP groups. Histopathologically, the mean distance between SSE and ML in the sections was found longer in the control group (78.6 +/- 10.7 mu m) than in the EM (44.38 +/- 18.26 mu m) and MP (44.05. +/- 18.25 mu m) groups. We think that administration of EM, which is a well-known macrolid antibiotic, might be very effective in the treatment of aseptic inflammation of TMJ space. Because corticosteroid administration has many side effects, EM may be a preferable drug in the treatment of inflammation of TMJ