![]() The underlying pathological feature of DHF/DSS, also known as Severe Dengue, is an acute increase in vascular permeability leading to hypovolemia and shock. ![]() While most cases manifest as a self-resolving fever, ∼1.5% of infections develop into a more severe dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), which causes ∼20,000 deaths annually. These results highlight the importance of using a suitable promoter for removal of radionuclides from solution.ĭengue virus (DENV) currently circulates in more than 100 countries and causes an estimated 390 million infections per year. radiodurans cells when lyophilized retained high levels of PhoN activity and precipitated uranium efficiently. Such cells showed faster removal of high concentrations of uranium than recombinant cells expressing PhoN under a radiation non-inducible deinococcal promoter, P groESL and could precipitate uranium even after continuous exposure to 0.6 Gy/min gamma radiation for 10 days. Highest whole cell PhoN activity was obtained after 2 h in post irradiation recovery following 8 kGy of high dose rate radiation. radiodurans carrying acid phosphatase gene, phoN under the regulation of P ssb when exposed to 7 kGy gamma radiation at two different dose rates of 56.8 Gy/min and 4 Gy/min, showed 8–9 fold increase in acid phosphatase activity. We provide a proof of principle for augmentation of uranium bioprecipitation using the radiation inducible promoter, P ssb from Deinococcus radiodurans. In crustaceans, the terminal hydroxylases are influenced by molt inhibiting hormone.īioremediation is an attractive option for the treatment of radioactive waste. Developmental correlations suggest that the sterol 7,8-dehydrogenase and terminal hydroxylases in Manduca prothoracic glands are not regulated by prothoracicotropic hormone, in contrast to the utilization of 7-dehydrocholesterol. Extensive pharmacological investigations of ecdysone 20-monooxygenase continue, and efforts toward the isolation and sequencing of this enzyme are underway. The lack of tissue and substrate specificity reported for the terminal hydroxylations of exogenous substrates suggests that non-specific hydroxylases may be involved. The sterol 7,8-dehydrogenating enzyme, the sequential terminal hydroxylases and ecdysone 20-monooxygenase all exhibit properties of cytochrome P-450 enzymes. The physiological relevance of 3-dehydroecdysteroids in some insects has only recently been appreciated. Conclusive evidence for many potential mechanisms of sterol 7,8-dehydrogenation and conversion of the Δ 5,7-sterols to 2,22,25-trideoxyecdysteroids is still lacking, though circumstantial evidence for a 5,6-epoxy- Δ 7-sterol is discussed. ![]() 7-Dehydrosterols are converted directly into ecdysteroids by insect prothoracic glands and ovaries, as well as crustacean Y-organs. While Δ 5-sterols are precursors in arthropod ecdysteroid biosynthesis, the Δ 7-sterol, lathosterol, is the precursor in at least some plants. The sterol 24-dealkylation system, present in the midgut of many species, is entirely absent in some members of at least four insect orders and the prothoracic glands of Manduca sexta. Many advances in arthropod sterol metabolism, as it relates to ecdysteroid biosynthesis, have been made in the past 10 yr. The traditional name for crustacean hormones, molt-inhibiting hormone, gonad-inhibiting hormone, and mandibular organ-inhibiting hormone, as well as hyperglycemic hormone seems to be loose in the information, as it conveys many effects. Investigations on eyestalk hormones have yet provided confusion to study the mechanism of action of each hormone, but have pointed to important areas of crustacean physiology related to the hormones. Some eyestalk hormones are discussed in term of the inhibitor of its physiological processes. The identification of two ecdysteroids that can lead to molting in the crayfish opened up new lines for physiological research on hormonal regulation during its development. ![]() The chemical and molecular information for crustacean endocrinology is presented and the role of ecdysteroids as molting hormone is substantiated from several approaches. Several aspects of molting hormones and the possible biosynthetic significance involved in the molting process are described in the chapter. This chapter reviews the unique hormone structures in the red swamp crayfish. ![]()
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