Sickle cell disease (SCD) is the most common inherited red blood cell disorder in the United States, affecting 70 000 to 100 000 Americans and causing a range of serious medical complications. Although the cause of SCD was established decades ago, existing therapies have varied effectiveness and side effects, and development of novel therapies has been slow. The limitations of existing treatment options highlight the need for new therapies that are aligned with the desires of the community.
View Article and Find Full Text PDFImmunocytochemistry was used to investigate the developmental expression of the insulin-like neuropeptide bombyxin in the tobacco hornworm, Manduca sexta. A mouse monoclonal antibody raised against a synthetic peptide corresponding to bombyxin's A-chain N-terminus was used to localize a bombyxin-like peptide to a group of cerebral medial neurosecretory cells, the M-NSC IIa(2). Immunostaining was first detected on day 0 of the second larval instar, localized in the M-NSC IIa(2) somata and in the neurohemal organ, the corpora allata (CA).
View Article and Find Full Text PDFAn in vitro method for investigating 20-hydroxyecdysone regulation of the corpora allata (CA) has been used to assess the kinetics of stimulation of precommitment day 3 fifth (V) larval instar Manduca sexta CA by 20-hydroxyecdysone. The synthesis of juvenile hormone (JH) I and III acids by 20-hydroxyecdysone-stimulated CA incubated as complexes with the brain-corpora cardiaca (Br-CC) increased similarly over time; the synthesis of JH III acid was greater than that of JH I acid. Maximal stimulation of the CA to synthesize both JH acids occurred when the Br-CC-CA were exposed to 20-hydroxyecdysone for 30-60 min.
View Article and Find Full Text PDFA previous study of the role of 20-hydroxyecdysone in the regulation of juvenile hormone (JH) biosynthesis during pupal commitment in the last (fifth, V) larval instar of Manduca sexta revealed that the increase in the hemolymph edysteroid titer that elicits commitment also stimulates the corpora allata (CA) to synthesize JHs I and III and/or their acids. This stimulation is exerted indirectly via the brain-corpora cardiaca and results in the postcommitment increase in the JH titer that is important for the molt to a pupa. The possibility that a similar form of interendocrine regulation of JH biosynthesis by 20-hydroxyecdysone is involved in the control of larval molting in Manduca was investigated for the molt from the fourth (IV) to the V larval instar.
View Article and Find Full Text PDFIn the adult mosquito, Aedes aegypti, the cerebral egg development neurosecretory hormone (EDNH) regulates reproduction by activating the ovaries to synthesize the steroid hormone ecdysone, while during postembryonic development the cerebral prothoracicotropic hormone (PTTH) activates the prothoracic glands to synthesize ecdysone. In each case, ecdysone than drives stage-specific physiological processes. Since EDNH and PTTH share a common steroidogenic function, it is conceivable that they are similar, if not the same, peptide(s).
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