Chronic activation of mu-opioid receptors, which couple to pertussis toxin-sensitive Gai/o proteins to inhibit adenylyl cyclase (AC), leads to a compensatory sensitization of AC. Pertussis toxin-insensitive mutations of Gai/o subtypes, in which the pertussis toxin-sensitive cysteine is mutated to isoleucine (Ga i=o), were used to determine whether each of the Gai/o subtypes is able to mediate s...

OBJECTIVES Ridinilazole (SMT19969) is a narrow-spectrum, non-absorbable antimicrobial with activity against Clostridium difficile undergoing clinical trials. The purpose of this study was to assess the pharmacological activity of ridinilazole and assess the effects on cell morphology. METHODS Antibiotic killing curves were performed using the epidemic C. difficile ribotype 027 strain, R20291,...

Type II (proteic) toxin-antitoxin (TA) operons are widely spread in bacteria and archaea. They are organized as operons in which, usually, the antitoxin gene precedes the cognate toxin gene. The antitoxin generally acts as a transcriptional self-repressor, whereas the toxin acts as a co-repressor, both proteins constituting a harmless complex. When bacteria encounter a stressful environment, TA...

The enterotoxin from Vibrio cholerae is selectively concentrated from cell-free culture supernatant by co-precipitation with hexametaphosphate and is further purified by adsorption on aluminum hydroxide powder. The bulk of residual somatic antigen becomes insoluble upon lyophilization of the toxin preparation and is removed by centrifugation of the rehydrated material. Other contaminants are el...

The bacterial type VI secretion system (T6SS) is a supra-molecular complex akin to bacteriophage tails, with VgrG proteins acting as a puncturing device. The Pseudomonas aeruginosa H1-T6SS has been extensively characterized. It is involved in bacterial killing and in the delivery of three toxins, Tse1-3. Here, we demonstrate the independent contribution of the three H1-T6SS co-regulated vgrG ge...

Anti-neutrophil cytoplasm autoantibodies (ANCA) are implicated in the pathogenesis of systemic vasculitis. Intact ANCA IgG activate superoxide generation in cytokine-primed neutrophils after binding their antigens and co-engaging Fcgamma receptors (FcgammaR). The contribution of antigen binding via ANCA F(ab')(2) fragments to signaling has been unclear. This study shows that both ANCA IgG and F...

OBJECTIVES/HYPOTHESIS To review the clinical characteristics and management of patients with palatal myoclonus and devise an algorithm for treatment with botulinum toxin based on presenting symptoms, clinical examination findings, and involved muscle groups. STUDY DESIGN Retrospective chart review at two clinical research centers. METHODS Between 1985 and 2011, 15 patients with a diagnosis ...

Toxin-antitoxin (TA) systems are small genetic modules that encode a toxin (that targets an essential cellular process) and an antitoxin that neutralises or suppresses the deleterious effect of the toxin. Based on the molecular nature of the toxin and antitoxin components, TA systems are categorised into different types. Type III TA systems, the focus of this review, are composed of a toxic end...

background botulism is a toxin-induced paralytic illness characterized by cranial nerve palsies and descending flaccid paralysis. botulinum toxin is regarded as the most lethal ever-known substance. the diagnosis in sporadic cases and even in small outbreaks is the main physicians’ challenge. the aim of this study was to assess clinical presentations of 80 cases of botulism referred to loghman ...

Alternaria brown spot disease is caused by the alternata tangerine pathotype, which relies on ACT-toxin for infection. At present, all identified biosynthesis-related genes are multi-copy genes. In this study, we summarized advances in important host-specific toxins (HSTs), and listed key required pathogenicity of A. pathotype. Toxin virulence test results revealed that different citrus species...