The role of the single interchains disulfide bond in tetanus and botulinum neurotoxins and the development of antitetanus and antibotulism drugs

A large number of bacterial toxins consist of active and cell binding protomers linked by an interchain disulfide bridge. The largest family of such disulfide-bridged exotoxins is that of the clostridial neurotoxins that consist of two chains and comprise the tetanus neurotoxins causing tetanus and the botulinum neurotoxins causing botulism. Reduction of the interchain disulfide abolishes toxicity, and we discuss the experiments that revealed the role of this structural element in neuronal intoxication. The redox couple thioredoxin reductase-thioredoxin (TrxR-Trx) was identified as the responsible for reduction of this disulfide occurring on the cytosolic surface of synaptic vesicles. We then discuss the very relevant finding that drugs that inhibit TrxR-Trx also prevent botulism. On this basis, we propose that ebselen and PX-12, two TrxR-Trx specific drugs previously used in clinical trials in humans, satisfy all the requirements for clinical tests aiming at evaluating their capacity to effectively counteract human and animal botulism arising from intestinal toxaemias such as infant botulism

Hydrogen peroxide is a neuronal alarmin that triggers specific RNAs, local translation of Annexin A2, and cytoskeletal remodeling in Schwann cells

Schwann cells are key players in neuro-regeneration: They sense "alarm" signals released by degenerating nerve terminals and differentiate toward a proregenerative phenotype, with phagocytosis of nerve debris and nerve guidance. At the murine neuromuscular junction, hydrogen peroxide (H2O2) is a key signal of Schwann cells' activation in response to a variety of nerve injuries. Here we report that Schwann cells exposed to low doses of H2O2 rewire the expression of several RNAs at both transcriptional and translational levels. Among the genes positively regulated at both levels, we identified an enriched cluster involved in cytoskeleton remodeling and cell migration, with the Annexin (Anxa) proteins being the most represented family. We show that both Annexin A2 (Anxa2) transcript and protein accumulate at the tips of long pseudopods that Schwann cells extend upon H2O2 exposure. Interestingly, Schwann cells reply to this signal and to nerve injury by locally translating Anxa2 in pseudopods, and undergo an extensive cytoskeleton remodeling. Our results show that, similarly to neurons, Schwann cells take advantage of local protein synthesis to change shape and move toward damaged axonal terminals to facilitate axonal regeneration

20 years of experience with tumour necrosis factor inhibitors : what have we learned?

TNF inhibitors are biologic DMARDs approved for the treatment of active RA in mid-1990s. They still represent a valuable therapeutic option to control the activity, disability and radiographic progression of the disease. In the context of TNF inhibitors, there are currently several molecules and different administration routes that provide optimal treatment personalization, allowing us to respond to a patient's needs in the best possible way. The increasing use of TNF inhibitors has not only improved the management of RA, but it has also helped in our understanding of the pathogenetic mechanisms of the disease. This review focuses on the basis of this targeted therapy and on the knowledge gained from their use about therapeutic effects and adverse events. Effectiveness analysed from drug registries and safety issues are presented together with recent data on infections (in particular, Mycobacterium tuberculosis and hepatitis B), cancer (lymphoma, skin cancers) and cardiovascular risk

Thermal performance of two heat exchangers for thermoelectric generators

Thermal performance of heat exchanger is important for potential application in integrated solar cell/module and thermoelectric generator (TEG) system. Usually, thermal performance of a heat exchanger for TEGs is analysed by using a 1D heat conduction theory which ignores the detailed phenomena associated with thermo-hydraulics. In this paper, thermal and mass transports in two different exchangers are simulated by means of a steady-state, 3D turbulent flow k -e model with a heat conduction module under various flow rates. In order to simulate an actual working situation of the heat exchangers, hot block with an electric heater is included in the model. TEG model is simplified by using a 1D heat conduction theory, so its thermal performance is equivalent to a real TEG. Natural convection effect on the outside surfaces of the computational model is considered. Computational models and methods used are validated under transient thermal and electrical experimental conditions of a TEG. It is turned out that the two heat exchangers designed have a better thermal performance compared with an existing heat exchanger for TEGs, and more importantly, the fin heat exchanger is more compact and has nearly half temperature rise compared with the tube heat exchanger

Lifestyle and dietary habits of patients with gout followed in rheumatology settings

Diet and lifestyles modification are core aspects of the non-pharmacological management of gout, but a poor consistency with suggested guidelines is reported. This study aimed to investigate dietary and lifestyle habits of patients with gout followed in rheumatology settings. Data were retrieved from the baseline dataset of the KING study, a multicentre cohort study of patients with gout followed in rheumatology settings. Dietary habits were assessed with the Italian National Institute of Statistics (ISTAT) food-frequency questionnaire and compared with reported data about general population. The relative increase of exposure was estimated by standardized prevalence ratios adjusted for gender, age and geographical distribution. The study population included 446 patients, with a mean age of 63.9 years and a M/F ratio of 9:1. Compared to the Italian population, gouty patients showed a higher prevalence of obesity [1.82 (1.52-2.18)] and a higher consumption of wine [1.85 (1.48-2.32)] and beer [2.21 (1.68-2.90)], but a lower prevalence of smoking and a lower intake of liquor. They showed a lower intake of red meat [0.80 (0.71-0.91)], but a similar intake of other tested dietary factors. Gouty patients' lifestyle is still partially different from the recommended