An Analysis of the Effects of Retinoic Acid and Other Retinoids on the Development of Adrenergic Cells from the Avian Neural Crest

In the present work, we have investigated the role of all-trans-retinoic acid (all-transRA), and several other natural and synthetic retinoids, in the development of adrenergic cells in quail neural crest cultures. Dose response studies using all-transRA and 13-cisRA revealed a dose-dependent increase in the number of adrenergic cells in neural crest cultures. Similar dose response studies using RA isomers and other natural retinoids did not result in the same increases. In order to determine the receptor mediating the effects of all-transRA in the neural crest, we tested several synthetic analogs which specifically bind to a particular RA receptor (RAR) subtype. We found that the compound AM 580, which activates the RAR-α, produced an increase in adrenergic cells similar to that seen with all-transRA. The compound TTNPB, which activates all RAR subtypes, also resulted in an increase in adrenergic cells. We conclude that the increase in adrenergic cells seen with all-transRA is mediated by RAR-α and possibly RAR-β. To further define the actions of all-transRA on the neural crest we incubated cultures with 5-bromo-2′-deoxyuridine (BrdU) to determine whether all-transRA could affect the rate of proliferation. The results show that while all-transRA did not increase the fraction of cells incorporating BrdU into their nuclei at early time points (24 h), it did increase BrdU incorporation by tyrosine hydroxylase (TH) positive cells at 5 days in culture. These findings demonstrate that the increase in adrenergic cells seen with all-transRA in neural crest cultures is likely due to an increase in the proliferation of cells already expressing TH.     

The effect of aluminum in soft water at low pH on oxygen consumption by the dragonfly Libellula julia Uhler

When subjected to a series of elevated Al and H⁺ concentrations spanning environmentally relevant levels, the dragonfly Libellula julia respired at a rate lower than the controls. This trend was consistent at all levels but only attained significance (p < 0.05) at pH 4.0 with A1 levels of 3.0 and 30 mg 1^–1. Low pH alone does not depress respiratory rates as greatly as Al and low pH combined. The authors speculate on some apparent inconsistencies found in the literature.     

Latent transforming growth factor beta binding protein 4: A regulator of mitochondrial function in acute kidney injury

Recently, latent transforming growth factor beta binding protein 4 (LTBP4) was implicated in the pathogenesis of renal damage through its modulation of mitochondrial dynamics. The seminal article written by Su et al. entitled “LTBP4 (Latent Transforming Growth Factor Beta Binding Protein 4) Protects Against Renal Fibrosis via Mitochondrial and Vascular Impacts” uncovers LTBP4's renoprotective role against acute kidney injury via modulating mitochondrial dynamics. Recently, LTBP4 has emerged as a driver in the mitochondrial-dependent modulation of age-related organ pathologies. This article aims to expand our understanding of LTBP4's diverse roles in these diseases in the context of these recent findings.     

Qualitative evaluation of fuelwood in Florida —A summary report

This report summarizes qualitative information on 5 potential Florida fuelwood species: slash pine, sand pine, melaleuca, eucalypt, and casuarina. The important factors affecting the quality of fuelwood for industrial applications are briefly discussed. Fundamental properties relating to the fuel quality of these 5 potential fuelwoods are synthesized from several published and unpublished reports. Based on the qualitative data shown in this report, it appears that the fuel characteristics of these 5 species are comparable or superior to those of many other woods evaluated in the literature.     

Nodule culture and regeneration of Eucalyptus grandis hybrids

Callus of three superior Eucalyptus grandis hybrids was induced from immature inflorescences, floral parts, shoot tips, zygotic embryos, and hypocotyl explants on various auxin (2,4-D or NAA) and cytokinin (kinetin) supplemented media. Hypocotyl callus initiated on 4 mg/l NAA and 1 mg/l kinetin formed massive nodular structures, and shoots and roots after four weeks on hormone free-medium. Callus from all other expiants turned brown and died upon transfer to hormone free or reduced hormone media. The nodular structures originating from hypocotyl-callus were maintained by subculture for over three years and retained the ability to form thousands of shoots. Shoots were successfully rooted (98% rooting) and plantlets developed were transferred to mist-greenhouse and then to greenhouse conditions with 95% survival. Plantlets were grown for six months in the greenhouse without sign of abnormal growth.Abbreviations NAA naphthalene acetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indoleacetic acid - MS Murashige and Skoog Medium (1962) - IBA indolebutyric acid     

EDC3 phosphorylation regulates growth and invasion through controlling P‐body formation and dynamics

Regulation of mRNA stability and translation plays a critical role in determining protein abundance within cells. Processing bodies (P‐bodies) are critical regulators of these processes. Here, we report that the Pim1 and 3 protein kinases bind to the P‐body protein enhancer of mRNA decapping 3 (EDC3) and phosphorylate EDC3 on serine (S)161, thereby modifying P‐body assembly. EDC3 phosphorylation is highly elevated in many tumor types, is reduced upon treatment of cells with kinase inhibitors, and blocks the localization of EDC3 to P‐bodies. Prostate cancer cells harboring an EDC3 S161A mutation show markedly decreased growth, migration, and invasion in tissue culture and in xenograft models. Consistent with these phenotypic changes, the expression of integrin β1 and α6 mRNA and protein is reduced in these mutated cells. These results demonstrate that EDC3 phosphorylation regulates multiple cancer‐relevant functions and suggest that modulation of P‐body activity may represent a new paradigm for cancer treatment.     

Risk Factors for Acquired Rifamycin and Isoniazid Resistance: A Systematic Review and Meta-Analysis

BackgroundStudies looking at acquired drug resistance (ADR) are diverse with respect to geographical distribution, HIV co-infection rates, retreatment status and programmatic factors such as regimens administered and directly observed therapy. Our objective was to examine and consolidate evidence from clinical studies of the multifactorial aetiology of acquired rifamycin and/or isoniazid resistance within the scope of a single systematic review. This is important to inform policy and identify key areas for further studies.MethodsCase-control and cohort studies and randomised controlled trials that reported ADR as an outcome during antitubercular treatment regimens including a rifamycin and examined the association of at least 1 risk factor were included. Post hoc, we carried out random effects Mantel-Haenszel weighted meta-analyses of the impact of 2 key risk factors 1) HIV and 2) baseline drug resistance on the binary outcome of ADR. Heterogeneity was assessed used I² statistic. As a secondary outcome, we calculated median cumulative incidence of ADR, weighted by the sample size of the studies.ResultsMeta-analysis of 15 studies showed increased risk of ADR with baseline mono- or polyresistance (RR 4.85 95% CI 3.26 to 7.23, heterogeneity I² 58%, 95% CI 26 to 76%). Meta-analysis of 8 studies showed that HIV co-infection was associated with increased risk of ADR (RR 3.02, 95% CI 1.28 to 7.11); there was considerable heterogeneity amongst these studies (I² 81%, 95% CI 64 to 90%). Non-adherence, extrapulmonary/disseminated disease and advanced immunosuppression in HIV co-infection were other risk factors noted. The weighted median cumulative incidence of acquired multi drug resistance calculated in 24 studies (assuming whole cohort as denominator, regardless of follow up DST) was 0.1% (5^th to 95^th percentile 0.07 to 3.2%).ConclusionBaseline drug resistance and HIV co-infection were significant risk factors for ADR. There was a trend of positive association with non-adherence which is likely to contribute to the outcome of ADR. The multifactorial aetiology of ADR in a programmatic setting should be further evaluated via appropriately designed studies.