Storage of Blood in the Mammalian Spleen: an Evolutionary Perspective

Apnoea as a novel method to improve exercise performance: A current state of the literature

Acute breath-holding (apnoea) induces a spleen contraction leading to a transient increase in haemoglobin concentration. Additionally, the apnoea-induced hypoxia has been shown to lead to an increase in erythropoietin concentration up to 5 h after acute breath-holding, suggesting long-term haemoglobin enhancement. Given its potential to improve haemoglobin content, an important determinant for oxygen transport, apnoea has been suggested as a novel training method to improve aerobic performance. This review aims to provide an update on the current state of the literature on this topic. Although the apnoea-induced spleen contraction appears to be effective in improving oxygen uptake kinetics, this does not seem to transfer into immediately improved aerobic performance when apnoea is integrated into a warm-up. Furthermore, only long and intense apnoea protocols in individuals who are experienced in breath-holding show increased erythropoietin and reticulocytes. So far, studies on inexperienced individuals have failed to induce acute changes in erythropoietin concentration following apnoea. As such, apnoea training protocols fail to demonstrate longitudinal changes in haemoglobin mass and aerobic performance. The low hypoxic dose, as evidenced by minor oxygen desaturation, is likely insufficient to elicit a strong erythropoietic response. Apnoea therefore does not seem to be useful for improving aerobic performance. However, variations in apnoea, such as hypoventilation training at low lung volume and repeated-sprint training in hypoxia through short end-expiratory breath-holds, have been shown to induce metabolic adaptations and improve several physical qualities. This shows promise for application of dynamic apnoea in order to improve exercise performance. HIGHLIGHTS: What is the topic of this review? Apnoea is considered as an innovative method to improve performance. This review discusses the effectiveness of apnoea (training) on performance. What advances does it highlight? Although the apnoea-induced spleen contraction and the increase in EPO observed in freedivers seem promising to improve haematological variables both acutely and on the long term, they do not improve exercise performance in an athletic population. However, performing repeated sprints on end-expiratory breath-holds seems promising to improve repeated-sprint capacity.

Size-Dependent In Vivo Transport of Nanoparticles: Implications for Delivery, Targeting, and Clearance

Understanding the in vivo transport of nanoparticles provides guidelines for designing nanomedicines with higher efficacy and fewer side effects. Among many factors, the size of nanoparticles plays a key role in controlling their in vivo transport behaviors due to the existence of various physiological size thresholds within the body and size-dependent nano-bio interactions. Encouraged by the evolving discoveries of nanoparticle-size-dependent biological effects, we believe that it is necessary to systematically summarize the size-scaling laws of nanoparticle transport in vivo. In this review, we summarized the size effect of nanoparticles on their in vivo transport along their journey in the body: begin with the administration of nanoparticles via different delivery routes, followed by the targeting of nanoparticles to intended tissues including tumors and other organs, and eventually clearance of nanoparticles through the liver or kidneys. We outlined the tools for investigating the in vivo transport of nanoparticles as well. Finally, we discussed how we may leverage the size-dependent transport to tackle some of the key challenges in nanomedicine translation and also raised important size-related questions that remain to be answered in the future.

Clinical effects of immunization, bleeding, and albumin-based fluid therapy in horses used as immunoglobulin source to produce a polyspecific antivenom (Echitab-plus-ICP) towards venoms of African snakes

During the production of snake antivenoms, the animals used as immunoglobulin source are subjected to processes that could deteriorate their physical condition. Therefore, these conditions must be carefully designed and validated. In this work, the immunization and bleeding protocols applied to horses used to produce the African polyspecific antivenom EchiTAb-plus-ICP were evaluated regarding their effects on the horses' health. The study focused on horses that had been previously immunized with venoms and then received periodic booster venom injections for antivenom production. It was found that the periodic immunization with 5 mg of a mixture of venoms of Bitis arietans, Echis ocellatus, Dendroaspis polylepis, and Naja nigricollis did not induce systemic signs of envenomation, and only caused mild swelling at the injection site, which did not evolve to abscesses, fistulas, or fibrosis. Three consecutive days of bleeding, collecting 6-8 L of blood per day, and self-transfusing the red blood cells (RBC) in the second and third days, did not induce evident cardiorespiratory alterations. However, this procedure caused significant reductions in RBC, hematocrit, hemoglobin, and total plasma protein values. Seven weeks after bleeding, these parameters were recovered, and horses were ready for the next immunization/bleeding cycle. The intravenous administration of equine albumin, at a dose of 2 g/kg body weight, increased the apparent plasma volume and the albumin concentration. However, this procedure induced early adverse reactions and transient alterations of the serum levels of the enzyme gamma-glutamyl transferase (GGT), thus suggesting some degree of hepatic injury. It was concluded that immunization and bleeding as described in this work do not cause significant clinical alterations in the horse's health, except for a transient drop in some hematological parameters. The albumin-based fluid therapy used does not hasten the recovery after bleeding but instead induces adverse events in the animals.

Genomic Instability and Cyto-Genotoxic Damage in Animal Species

Genomic instability is a condition that may be associated with carcinogenesis and/or physiological disorders when genetic lesions are not repaired. Besides, wild, captive, and domesticated vertebrates are exposed to xenobiotics, leading to health disorders due to cytogenotoxicity. This chapter provides an overview of tests to assess cytogenotoxicity based on micronuclei (MNi) formation. Bone marrow micronuclei test (BmMNt), peripheral blood erythrocyte micronuclei test (PBMNt), and lymphocyte cytokinesis blocking micronuclei assay (CBMN) are discussed. The most illustrative studies of these techniques applied in different vertebrates of veterinary interest are described. The values of spontaneous basal micronuclei in captive, experimental, and farm animals (rodents, hamsters, pigs, goats, cattle, horses, fish) are summarized. In addition, a flow cytometry technique is presented to reduce the time taken to record MNi and other cellular abnormalities. Flow cytometry is helpful to analyze some indicators of genomic instability, such as cell death processes and stages (necrosis, apoptosis) and to efficiently evaluate some biomarkers of genotoxicity like MNi in BmMNt, PBMNt, and CBMN. The intention is to provide veterinary professionals with techniques to assess and interpret cytogenotoxicity biomarkers to anticipate therapeutic management in animals at risk of carcinogenesis or other degenerative diseases.