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Jellyfish have existed on the earth for around 600 million years and have evolved in response to environmental changes. Hydrozoan jellyfish, members of phylum Cnidaria, exist in multiple life stages, including planula larvae, vegetativelypropagating polyps, and sexually-reproducing medusae. Although free-swimming medusae display complex morphology and exhibit increase in body size and regenerative ability, their underlying cellular mechanisms are poorly understood. Here, we investigate the roles of cell proliferation in body-size growth, appendage morphogenesis, and regeneration using Cladonema pacificum as a hydrozoan jellyfish model. By examining the distribution of S phase cells and mitotic cells, we revealed spatially distinct proliferating cell populations in medusae, uniform cell proliferation in the umbrella, and clustered cell proliferation in tentacles. Blocking cell proliferation by hydroxyurea caused inhibition of body size growth and defects in tentacle branching, nematocyte differentiation, and regeneration. Local cell proliferation in tentacle bulbs is observed in medusae of two other hydrozoan species, Cytaeis uchidae and Rathkea octopunctata, indicating that it may be a conserved feature among hydrozoan jellyfish. Altogether, our results suggest that hydrozoan medusae possess actively proliferating cells and provide experimental evidence regarding the role of cell proliferation in body-size control, tentacle morphogenesis, and regeneration. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To determine the effect of leuprolide acetate, a synthetic gonadotropin‐releasing hormone analog (GnRH‐a) on ovarian function preservation in systemic lupus erythematosus (SLE) patients treated with cyclophosphamide (CYC) in clinical practice. Methods: We enrolled 30 premenopausal female SLE patients who fulfilled the 1997 American College of Rheumatology revised criteria and were treated with intravenous CYC (IVCY) in 2008–2017. We used Kaplan–Meier survival estimates to compare the GnRH‐a‐treated patients and those not treated with GnRH‐a as controls. We performed Cox regression analyses to identify factors associated with premature ovarian failure (POF), incidences of cardiovascular events, strokes and osteoporosis after IVCY therapy. Results: After a mean follow‐up of 41 months, POF developed in one of the 16 GnRH‐a‐treated patients (6%) versus seven of the 14 controls (50%). Significantly improved cumulative ovarian protection over time was observed in the GnRH‐a‐treated group (P = 0.030). The hazard model analysis showed that treatment with GnRH‐a during IVCY therapy is an independent factor associated with POF after IVCY therapy (adjusted hazards ratio = 0.12, 95% CI 0.01–0.67, P = 0.013) but not incidences of cardiovascular events, strokes or osteoporosis. Conclusion: The combined use of GnRH‐a with IVCY therapy was associated with a significant reduction of POF among premenopausal women with SLE, suggesting that the addition of GnRH‐a can be a strategy to prevent POF among premenopausal women with SLE after IVCY therapy. [ABSTRACT FROM AUTHOR]