Adv Exp Med Biol
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The interactions between tumor cells and the non-malignant stromal and immune cells that make up the tumor microenvironment (TME) are critical to the pathophysiology of cancer. Mesenchymal stem cells (MSCs) are multipotent stromal stem cells found within most cancers and play a critical role influencing the formation and function of the TME. MSCs have been reported to support tumor growth through a variety of mechanisms including (i) differentiation into other pro-tumorigenic stromal components, (ii) suppression of the immune response, (iii) promotion of angiogenesis, (iv) enhancement of an epithelial-mesenchymal transition (EMT), (v) enrichment of cancer stem-like cells (CSC), (vi) increase in tumor cell survival, and (vii) promotion of tumor metastasis. ⋯ Tumor-suppressive effects are observed when MSCs are used in higher ratios to tumor cells. Additionally, MSC function appears to be tissue type dependent and may rely on cancer education to reprogram a naïve MSC with antitumor effects into a cancer-educated or cancer-associated MSC (CA-MSC) which develops pro-tumorigenic function. Further work is required to delineate the complex crosstalk between MSCs and other components of the TME to accurately assess the impact of MSCs on cancer initiation, growth, and spread.
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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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Breast cancer diagnosed during pregnancy or lactation up to 1 year post-partum is often referred to as pregnancy-associated breast cancer (PABC) , although the definition varies with length of post-partum period. The incidence rate has been reported to range from 17.5 to 39.9 per 100,000 births, but the rate is substantially lower during pregnancy (ranging from 3.0 to 7.7) than during the post-partum period (ranging from 13.8 to 32.2). ⋯ In studies comparing outcomes in women with PABC to other young breast cancer patients, it is crucial to adjust for age, since the age distribution of PABC depends both on age at pregnancy and age at breast cancer. Large studies have shown similar prognosis for women with PABC compared to other young women with breast cancer, when accounting for differences in age, stage and other tumour characteristics.
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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.
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Epigenetic mechanisms, which include DNA methylation, histone modification, and microRNA (miRNA), can produce heritable phenotypic changes without a change in DNA sequence. Disruption of gene expression patterns which are governed by epigenetics can result in autoimmune diseases, cancers, and various other maladies. Mechanisms of epigenetics include DNA methylation (and demethylation), histone modifications, and non-coding RNAs such as microRNAs. ⋯ In contrast to genetic changes, which are difficult to reverse, epigenetic aberrations can be pharmaceutically reversible. The emerging tools of epigenetics can be used as preventive, diagnostic, and therapeutic markers. With the development of drugs that target the specific epigenetic mechanisms involved in the regulation of gene expression, development and utilization of epigenetic tools are an appropriate and effective approach that can be clinically applied to the treatment of various diseases.