Adv Exp Med Biol
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β-hemolytic streptococci are major causes of necrotizing soft tissue infections (NSTIs), Streptococcus pyogenes (group A streptococcus; GAS) in particular. NSTIs caused by Streptococcus dysgalactiae (SD) have also been reported. In the INFECT cohort of 409 NSTIs patients, more than a third of the cases were caused by GAS (31%) or SD (7%). ⋯ As in other studies, a significant microbial diversity was observed, but with predominance of a few emm types. Overall, the INFECT study gives a comprehensive and contemporary picture of the clinical characteristics and the microbes involved in streptococcal NSTIs. The reported severity of disease underscores the need for new efforts aimed at identifying novel diagnostic measures and improved treatment.
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Regional anaesthesia involves targeting specific peripheral nerves with local anaesthetic. It facilitates the delivery of anaesthesia and analgesia to an increasingly complex, elderly and co-morbid patient population. Regional anaesthesia practice has been transformed by the use of ultrasound, which confers advantages such as accuracy of needle placement, visualisation of local anaesthetic spread, avoidance of intraneural injection and the ability to accommodate for anatomical variation. ⋯ Much research has been done, and is ongoing, with the aim of improving needle visualisation; this is also reviewed. Image interpretation requires the application of anatomical knowledge and understanding of the typical sonographic appearance of different tissues (as well as the needle). Years of practice are required to attain expertise, although it is hoped that continuing advances in nerve and needle visualisation, as described in this chapter, will expedite that process.
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A body of evidence indicates that peripheral nerves have an extraordinary yet limited capacity to regenerate after an injury. Peripheral nerve injuries have confounded professionals in this field, from neuroscientists to neurologists, plastic surgeons, and the scientific community. Despite all the efforts, full functional recovery is still seldom. ⋯ Resourcing to nerve guidance conduits, a variety of methods have been experimentally used to bridge peripheral nerve gaps of limited size, up to 30-40 mm in length, in humans. Herein, we aim to summarize the fundamentals related to peripheral nerve anatomy and overview the challenges and scientific evidences related to peripheral nerve injury and repair mechanisms. The most relevant reports dealing with the use of both synthetic and natural-based biomaterials used in tissue engineering strategies when treatment of nerve injuries is envisioned are also discussed in depth, along with the state-of-the-art approaches in this field.
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Myeloid-derived suppressor cells (MDSCs) represent a heterogenous population of immature myeloid cells capable of modulating immune responses. In the context of cancer, MDSCs are abnormally produced and recruited to the tumor microenvironment (TME) to aid in the establishment of an immunosuppressive TME that facilitates tumor escape. ⋯ In this chapter, we review MDSC characterization, development, expansion, and mechanisms that facilitate immunosuppression and tumor progression. Furthermore, we highlight studies demonstrating the clinical significance of MDSCs in various disease states in addition to strategies that modulate various aspects of MDSC biology for therapeutic gain.
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Immunoglobulins are key effector molecules in the humoral immune response. Intravenous polyspecific immunoglobulin (IVIG) is a preparation of polyclonal serum immunoglobulins, typically IgG, from thousands of donors. It has been used as adjunctive therapy in critically ill patients with severe infections, i.e. sepsis, septic shock, and necrotizing soft tissue infections. ⋯ A blinded, placebo-controlled clinical trial (INSTINCT) assessed the effect of IVIG in 100 intensive care unit patients with necrotizing soft tissue infections, including all bacterial etiologies. The study did not demonstrate any effect on self-reported physical functioning at 6 months. In this chapter, we review the mechanisms of action of IVIG and the clinical studies that are available for necrotizing soft tissue infections as well as severe group A streptococcal infections.