Adv Exp Med Biol
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Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), is similar to two other coronaviruses, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), in causing life-threatening respiratory infections and systemic complications in both children and adults. As the COVID-19 pandemic has continued to spread globally, increasing numbers of pregnant women have become infected, raising concern not only for their health but also for the health of their infants. This chapter discusses the effects of coronavirus infections, e.g., MERS, SARS, and COVID 19, on pregnancy and describes the evolving knowledge of COVID 19 among pregnant women. ⋯ The effects of COVID-19 on the placenta, fetus, and neonate are also reviewed, including potential clinical outcomes and issues relating to testing and diagnosis. The potential mechanisms of vertical transmission of the virus between pregnant women and their infants are analyzed, including intrauterine, intrapartum, and postpartum infections. Several recent studies have reported the detection of SARS-CoV-2 in tissues from the fetal side of the placenta, permitting the diagnosis of transplacental infection of the fetus by SARS-CoV-2. Placentas from infected mothers in which intrauterine transplacental transmission of SARS-CoV-2 has occurred demonstrate an unusual combination of pathology findings which may represent risk factors for placental as well as fetal infection.
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Hemorrhagic shock (HS) is a severe complication of traumatic brain injury (TBI) that doubles mortality due to severely compromised microvascular cerebral blood flow (mvCBF) and oxygen delivery reduction, as a result of hypotension. Volume expansion with resuscitation fluids (RF) for HS does not improve microvascular CBF (mvCBF); moreover, it aggravates brain edema. We showed that the addition of drag-reducing polymers (DRP) to crystalloid RF (lactated Ringer's) significantly improves mvCBF, oxygen supply, and neuronal survival in rats suffering TBI+HS. ⋯ HES (p < 0.05). Thus, resuscitation after TBI+HS using HES-DRP effectively restores mvCBF and reduces hypoxia, microthrombosis, and neuronal necrosis compared to HES. HES-DRP is more neuroprotective than lactated Ringer's with DRP and requires an infusion of a smaller volume, which reduces the development of hypervolemia-induced brain edema.
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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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There are several mechanisms that cause memory impairment, including motivated forgetting, active forgetting, natural decay, and memory interference. Interference occurs when one is attempting to recall something specific, but there is conflicting information making it more difficult to recall the target stimuli. In laboratory settings, it is common to measure memory interference with paired associate tasks-usually utilizing the AB-CD, AB-AC, AB-ABr, or AB-DE AC-FG method. ⋯ The memory effects of each condition differ, but are all related to alterations in brain physiology and general memory deterioration. Exercise, or physical activity, has been demonstrated to attenuate memory interference in some cases, but the mechanisms are still being determined. Further research is needed on memory interference, in regard to exercise and neuropsychiatric disorders.
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As a classical form of programmed cell death, autophagy is widely involved in cellular metabolism and vital for the maintenance of homeostasis in physiological and pathological states. With multiple levels of regulation and signaling integrated in, autography presents complicated relevance with various diseases, such as cancer and neurological diseases. The emerging subject, systems biology, along with multi-omics approaches, offers a new strategy to investigate these interactive processes from a holistic perspective. ⋯ The critical step of systematic study is to explore interplay between biological molecules based on massive biological data, which requires construction of networks in different biological levels, modification, and identification of key pathways and targets via optimized algorithm and experimental verification. Guided by systems biology research, drug design can thus be strengthened by efficient screening and accurate evaluation. Overall, systems biology promises to act as a powerful tool which both helps to clarify the profound mechanism and to develop efficacious medicine.