Retinoic acid regulates avian lung branching through a molecular network

Retinoic acid (RA) is of major importance during vertebrate embryonic development and its levels need to be strictly regulated otherwise congenital malformations will develop. Through the action of specific nuclear receptors, named RAR/RXR, RA regulates the expression of genes that eventually influence proliferation and tissue patterning. RA has been described as crucial for different stages of mammalian lung morphogenesis, and as part of a complex molecular network that contributes to precise organogenesis; nonetheless, nothing is known about its role in avian lung development. The current report characterizes, for the first time, the expression pattern of RA signaling members (stra6, raldh2, raldh3, cyp26a1, rar alpha, and rar beta) and potential RA downstream targets (sox2, sox9, meis1, meis2, tgf beta 2, and id2) by in situ hybridization. In the attempt of unveiling the role of RA in chick lung branching, in vitro lung explants were performed. Supplementation studies revealed that RA stimulates lung branching in a dose-dependent manner. Moreover, the expression levels of cyp26a1, sox2, sox9, rar beta, meis2, hoxb5, tgf beta 2, id2, fgf10, fgfr2, and shh were evaluated after RA treatment to disclose a putative molecular network underlying RA effect. In situ hybridization analysis showed that RA is able to alter cyp26a1, sox9, tgf beta 2, and id2 spatial distribution; to increase rar beta, meis2, and hoxb5 expression levels; and has a very modest effect on sox2, fgf10, fgfr2, and shh expression levels. Overall, these findings support a role for RA in the proximal-distal patterning and branching morphogenesis of the avian lung and reveal intricate molecular interactions that ultimately orchestrate branching morphogenesis.The authors would like to thank Ana Lima for slide sectioning and Rita Lopes for contributing to the initiation of this project. This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the Project POCI-01-0145-FEDER-007038; and by the Project NORTE-01-0145- FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

Causes for increased myelosuppression with increasing age in patients with oesophageal cancer treated by chemoradiotherapy

The aim of this study was to identify why increasing myelosuppression accompanies increasing age in patients treated for oesophageal cancer by chemoradiation. Weekly neutrophil and platelet counts were obtained throughout treatment in 86 patients undergoing chemoradiation without surgery for oesophageal cancer. One or two cycles of cisplatin 80 mg/m(2)/day followed by 5-fluorouracil 800 mg/m(2)/day for 4-5 days were administered during the first and fourth or fifth week of radiotherapy using 2 Gy daily fractions. 44 of the patients underwent 5-fluorouracil pharmacokinetic studies. Multiple regression procedures were used to determine the strength of factors that contribute to initial and nadir neutrophil and platelet counts. The kinetics of myeloid response were evaluated from the rates of disappearance and re-appearance of neutrophils and platelets during treatment. Age, fluorouracil dose (or AUG), baseline body weight and neutrophil (or platelet) count were found to be powerfully and independently predictive of both first neutrophil and platelet nadir count. Baseline neutrophil and platelet counts were also found to correlate negatively with advancing age independently of other factors. The rate of descent of both indices, however, was independent of age, baseline count and fluorouracil dose suggesting that variations in the size of the myeloproliferative compartment prior to treatment were responsible for interpatient variations. In addition, the rate of recovery of both indices was not influenced by age amongst patients in whom data was assessable suggesting that proliferation of surviving marrow elements is not compromised by age. These data are compatible with the hypothesis that a progressive depletion of the myeloid stem cell compartment accompanies advancing age, and that this is responsible for increasing myelotoxicity. (C) 1999 Elsevier Science Ltd. All rights reserved

A comparison of cancer statistics in New Zealand and Australia: 1996-2007

AIM: To compare the burden and outcomes of cancer in New Zealand with those in Australia. METHODS: For the years 1996-1997 and 2006-2007, the incidence and mortality of cancer in New Zealand and Australia was compared to determine if differences between the two countries had changed over the decade under study. Summarised cancer data from New Zealand and Australia, age standardised to the 2002 World Health Organisation's standard population, were used to make the comparisons. RESULTS: For the 11 year timeframe of this study, total rates of cancer incidence reduced in New Zealand and increased in Australia. The incidence of cancer in New Zealand, relative to Australia, changed from an excess of +10.3 to a deficit of -27.5 per 100,000 people. When considering the excess in terms of gender, the annual excess of cancer registrations for New Zealand females fell from +19.9 to +0.9 per 100,000, and male cancer registration fell from an excess of +3.7 to a deficit of -58.0 per 100,000, due almost entirely to a surge in prostate cancer registration in Australia. Over the same 11-year timeframe, cancer-specific mortality rates decreased in both countries, but there was no change in the difference between New Zealand and Australian rates, which remained 10% higher in New Zealand. Similar to findings on 1996/7 data, the main cancer sites responsible for the overall excess mortality in 2006/7 were colorectal cancer in both sexes, and lung and breast cancer in females. CONCLUSION: The persisting different cancer mortality rates between the two countries is likely to have been partly due to lifestyle and ethnic differences in the populations, and partly due to New Zealanders presenting with more advanced cancers and having less easy access to some treatments. Until we know the relative contributions of these factors, it will be difficult for New Zealand to plan interventions in the future which have a good chance of lifting our cancer survival rates to those of our closest neighbour. The collection of clinical stage on all new cancer registrations would provide the base information required.John Waldon, David S Lamb, Brett Delahunt, John N Nacey, Peter J Dady, Carol A Johnson, Alan G Hall, Peter B Bethwaite, Philip Weinstei