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Complementary Snail Control in Chemotherapeutic-Based Control Programs
Published in Max J. Miller, E. J. Love, Parasitic Diseases: Treatment and Control, 2020
A diagrammatic representation of this seasonality is illustrated in Figure 2. The optimal conditions for the snails are denoted by the solid bar across the top of the graph. When these conditions start, the number of snails builds up rapidly before stabilizing at some level dictated by the characteristics of the habitats in an area.10 Conversely, when conditions turn unfavorable, the snail populations decline often rapidly and catastrophically, although a small residual population survives in protected refuges or by some escape mechanism such as estivation.9,14,24
The Anopheles vector
Published in David A Warrell, Herbert M Gilles, Essential Malariology, 2017
Mike W Service, Harold Townson
In hot regions, during the dry season when larval habitats are scarce, females of some species may seek shelter in cool, damp places, such as on the walls of wells. Although continuing to blood feed, they do not lay eggs until the beginning of the rains, although fully developed eggs may be present in their ovaries. Such seasonal behaviour is termed aestivation. Anopheles arabiensis is thought to survive the dry season in Khartoum and Omdurman in the Sudan by aestivating. In temperate areas, but also in some hot countries that experience seasonal cool periods, females may seek shelter from the cold in hibernation sites, such as caves, buildings or rodent burrows. Before hibernation, females of some species may undertake a pre-hibernation flight, which is longer than their normal ones. In Israel, 14-km prehibernation flights have been recorded in A. sacharovi and, in California, A. freebomi may fly up to 42 km to seek out hibernation sites. Before hibernation, a last blood meal is taken from which abdominal fat reserves, not eggs, are formed. If there is complete hibernation, females remain inactive in their sheltered sites until warmer weather returns. However, in some species there is only partial hibernation and females need to emerge periodically from their shelters to take blood meals to renew their fat reserves. Such incomplete hibernation occurs in A. sacharovi at the beginning of hibernation in Israel, and in A. atroparvus, feeding of which in the winter has resulted in cases of malaria in the Netherlands, Germany and England. Only fertilized females successfully hibernate. In some species, such as the European A. claviger and A. plumbeus, adults die with the onset of the cold season and the population over-winters as larvae.
Hibernation and Aging
Published in Shamim I. Ahmad, Aging: Exploring a Complex Phenomenon, 2017
Cheng-Wei Wu, Kenneth B. Storey
When challenged with unfavorable environmental conditions, organisms must adapt to their surroundings in order to survive, this is especially crucial for animals that encounter the cold and harsh conditions of winter. For many wintering mammals, the solution is hibernation, an adaptive physiological state characterized by the extreme depression of basal metabolic rate and body temperature. Mammals that undergo hibernation include monotremes, rodents, marsupials, bats, shrews, hedgehogs, black bear, and lemurs (Dausmann et al. 2004, Storey 2010). When hibernators enter torpor, they first undergo reductions in metabolic rate followed by a subsequent drop in body temperature. Once animals enter full torpor, their body temperature drops to near ambient, with heart rates reduced to approximately 5 beats per minute from 200 to 300, and respiration reduced to 4–6 breath per minute from 100 to 200. This dormant state can last between 5 and 15 days, after which torpor is interrupted by spontaneous arousal back to euthermia for 1 day, then followed by reentry into deep torpor. This torpor cycle is repeated for 10–20 bouts until the end of hibernation season (Carey, Andrews, and Martin 2003). This type of metabolic depression is also observed in other non-mammalian species as an adaptive response to stressful environments, with examples including freeze tolerance in frogs, diapause/dauer in nematodes, anoxia tolerance in turtles, and a estivation in snails (Churchill and Storey 1993, Fielenbach and Antebi 2008, Krivoruchko and Storey 2010, Wu, Biggar, and Storey 2013). Mammalian hypometabolism is of special interest as many hibernators must also deal with the threat of hypothermia development as they reduce their core body temperature to near ambient (∼5°C) during torpor. To coordinate and endure such drastic physiological changes, hibernators must essentially reprogram their whole body metabolism in order to maintain this dormant state while also activating appropriate cytoprotective responses to avoid cellular damage. In this chapter, we will briefly discuss metabolic regulations of hibernation and cellular processes that are regulated to help establish and maintain this hypometabolic state.
Wheel-running activity rhythms and masking responses in the diurnal palm squirrel, Funambulus pennantii
Published in Chronobiology International, 2020
Dhanananajay Kumar, Sanjeev Kumar Soni, Noga Kronfeld-Schor, Muniyandi Singaravel
The five-striped Indian palm squirrels (F. pennantii) are wild tropical rodents. They are day active and arboreal in nature (Cherukalady 2018), with an average adult body weight of around 110 ± 10 g. F. pennantii do not show seasonal rhythms like aestivation (summer dormancy) or hibernation (winter dormancy) like other sciurids (Seth and Prasad 1969). They are native to central and north India, Iran, Nepal, and Pakistan and can now be found also in Afghanistan, and were introduced to Western Australia during the period of the late eighteenth century. Squirrels can be located near agricultural field, in gardens, grasslands, scrublands, plantations, and tropical to subtropical dry deciduous forests. They live in tree trunk holes and buildings crevices near human habitats (Cherukalady 2018).
Impediment of selenite-induced cataract in rats by combinatorial drug laden liposomal preparation
Published in Libyan Journal of Medicine, 2019
Caixuan Huang, Cairui Li, Paerheti Muhemaitia
Zeta potential measurements provide an indication of size and charge of the nanocarrier systems which are extremely significant for the functional performance of the nanoliposomes [41,42] The size distribution of the nanocarrier helps improvement of appropriate nanocarriers for the particular therapeutic commitments as in this case, the prevention of cataract. Size also helps in estivation of in vivo drug release behavior, biological fate, toxicity and the specific directing of drugs co-encapsulated in liposomes after administration. Also it may impact the loading of combinatorial drugs, their release and stability of combinatorial drugs inside nanocarriers [43].
Red blood cells as an organ? How deep omics characterization of the most abundant cell in the human body highlights other systemic metabolic functions beyond oxygen transport
Published in Expert Review of Proteomics, 2018
Travis Nemkov, Julie A. Reisz, Yang Xia, James C. Zimring, Angelo D’Alessandro
The classification of RBCs as an organ is also relevant in that it could inform novel therapies that target RBC biology and leverage RBC cross talk to other cell types in order to achieve remission from diseases apparently unrelated to RBCs. Vice versa, RBCs may soon become tools to modulate systems homeostasis, not just in hypoxic recipients in need of a standard blood transfusion (the most common invasive medical procedure worldwide – with ~ 112 million blood units donated every year), but also through the generation and transfusion (transplantation?) of enhanced RBCs packed with enzymes that sequester and metabolize substrates indispensable, for example, for inflammation/immune cell activation, infection (especially of siderophilic bacteria) or cancer growth. Future studies will be aimed at understanding the impact on RBC biology of genetics, including sex dimorphism, ethnicity, but also species-specific evolutive adaptations. Understanding metabolic adaptations to extreme conditions such as hibernation in mammals or estivation in frogs may inform the designing of next generation of blood-based therapeutics that exploit as of yet unappreciated mechanisms. The impact of diet and exercise on RBC biology have been investigated for decades with classic biochemistry approaches, but giant leaps in this area are awaited with the introduction of omics tools. While significant strides have been made with respect to our understanding of RBC metabolic responses to high-altitude hypoxia, it is not clear whether these mechanisms are recapitulated as a function of pathogenic hypoxia, for example, in the case of ischemic and hemorrhagic hypoxia [134]. Similarly, it is not known whether RBC antioxidant responses can be boosted to treat pathologies associated with oxidant stress, such as sepsis or reperfusion injury. The impact of iatrogenic interventions, from anesthesia to extracorporeal membrane oxygenation (ECMO), from radio/chemotherapy to cardiopulmonary bypass may inform the next generation of therapies that leverage subject-specific RBC metabolic adaptations to hypoxia and oxidative stress – making the omics characterization of RBCs an important step toward personalized medicine in the clinic. In this view, the introduction of high-throughput metabolomics tools [135] will make the analysis of RBCs from large clinical cohorts amenable to cost and time-effective screening in observational studies, as well as in biomarker discovery studies with the potential to translate into clinical metabolomics applications [136].