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Background: In insects, an interplay between the activities of distinct hormones, such as juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulates the progression through numerous life history hallmarks. As a crucial endocrine factor, JH is mainly synthesized in the corpora allata (CA) to regulate multiple physiological and developmental processes, including molting, metamorphosis, and reproduction. During the last century, significant progress has been achieved in elucidating the JH signal transduction pathway, while less progress has been made in dissecting the regulatory mechanism of JH biosynthesis. Previous work has shown that receptor tyrosine kinase (RTK) signaling regulates hormone biosynthesis in both insects and mammals. Here, we performed a systematic RNA interference (RNAi) screening to identify RTKs involved in regulating JH biosynthesis in the CA of adult Blattella germanica females. Results: We found that the epidermal growth factor receptor (Egfr) is required for promoting JH biosynthesis in the CA of adult females. The Egf ligands Vein and Spitz activate Egfr, followed by Ras/Raf/ERK signaling, and finally activation of the downstream transcription factor Pointed (Pnt). Importantly, Pnt induces the transcriptional expression of two key enzyme-encoding genes in the JH biosynthesis pathway: juvenile hormone acid methyltransferase (JHAMT) and methyl farnesoate epoxidase (CYP15A1). Dual-luciferase reporter assay shows that Pnt is able to activate a promoter region of Jhamt. In addition, electrophoretic mobility shift assay confirms that Pnt directly binds to the − 941~ − 886 nt region of the Jhamt promoter. Conclusions: This study reveals the detailed molecular mechanism of Egfr signaling in promoting JH biosynthesis in the German cockroach, shedding light on the intricate regulation of JH biosynthesis during insect development. [ABSTRACT FROM AUTHOR]

Insects have evolved numerous adaptations and colonized diverse terrestrial environments. Several polyneopterans, including dictyopterans (cockroaches and mantids) and locusts, have developed oothecae, but little is known about the molecular mechanism, physiological function, and evolutionary significance of ootheca formation. Here, we demonstrate that the cockroach asymmetric colleterial glands produce vitellogenins, proline-rich protein, and glycine-rich protein as major ootheca structural proteins (OSPs) that undergo sclerotization and melanization for ootheca formation through the cooperative protocatechuic acid pathway and dopachrome and dopaminechrome subpathway. Functionally, OSP sclerotization and melanization prevent eggs from losing water at warm and dry conditions, and thus effectively maintain embryo viability. Dictyopterans and locusts convergently evolved vitellogenins, apolipoprotein D, and laminins as OSPs, whereas within Dictyoptera, cockroaches and mantids independently developed glycine-rich protein and fibroins as OSPs. Highlighting the ecological-evolutionary importance, convergent ootheca formation represents a successful reproductive strategy in Polyneoptera that promoted the radiation and establishment of cockroaches, mantids, and locusts. [ABSTRACT FROM AUTHOR]

Objective: The object of the present meta-analysis is to compare the effectiveness of transforaminal epidural steroid injection (TFESI) and interlaminar epidural steroid injection (ILESI) for treating patients with low back pain (LBP) secondary to lumbosacral radicular pain.Methods: A systematic search was performed in the PubMed and Embase databases and the Cochrane Library for relevant literature published through January 2016. The randomized controlled trials (RCTs) and controlled observational studies were selected, which did not only compare TFESI with ILESI but also reported the available data. The Cochrane Collaboration's Handbook and Newcastle-Ottawa Scale (NOS) were used for the methodological quality assessments of the RCTs and observational studies respectively. The meta-analysis was performed using the Revman 5.2 software.Results: A total of 931 patients from nine RCTs and four observational studies were subjected to meta-analysis. In primary outcomes, the TFESI patients experienced superior pain relief compared with the TFESI patients in RCTs (P = 0.01), but not in observational studies (p = 0.63). The pooled data of RCTs showed that the TFESI group presented superior clinical results in terms of visual analogue scale (VAS) than the ILESI group (p = 0.0005). Moreover, the numeric rating scale (NRS) specifically favored TFESI in the RCTs (p < 0000.1). Similar functional improvement and oswentry disability index (ODI) score were observed between TFESI and ILESI in RCTs (P = 0.62). In secondary outcomes, meta-analysis of RCTs and observational studies revealed that there were no statistically significant differences between both groups in regard to procedure frequency, surgery rate, and ventral epidural spread.Conclusions: According to the results of meta-analysis, TFESI to manage LBP provides superior short term pain relief and equal functional improvement when compared to ILESI. It has not shown a statistically significant difference between both groups with regard to procedure frequency, surgery rate, and ventral epidural spread. [ABSTRACT FROM AUTHOR]