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n our role as medical educators and researchers, we support in the strongest manner possible the personal autonomy and self-determination of our students, patients, and colleagues. A fundamental value of the medical profession is for the patient to have personal autonomy in their healthcare decisions, including how they would like to be identified. It is, and will continue to be, an important priority to be taught and encouraged throughout healthcare education,1 and it begins in the anatomy laboratory with the proper and respectful treatment of body donors.2 Learning this value continues with respecting and accepting this same autonomy in fellow students, staff, faculty, and patients.

[Background]: The development of the amniote limb has been an important model system to study patterning mechanisms and morphogenesis. For proper growth and patterning, it requires the interaction between the distal sub-apical mesenchyme and the apical ectodermal ridge (AER) that involve the separate implementation of coordinated and tissue-specific genetic programs., [Results]: Here, we produce and analyze the transcriptomes of both distal limb mesenchymal progenitors and the overlying ectodermal cells, following time-coursed dissections that cover from limb bud initiation to fully patterned limbs. The comparison of transcriptomes within each layer as well as between layers over time, allowed the identification of specific transcriptional signatures for each of the developmental stages. Special attention was given to the identification of genes whose transcription dynamics suggest a previously unnoticed role in the context of limb development and also to signaling pathways enriched between layers., [Conclusion]: We interpret the transcriptomic data in light of the known development pattern and we conclude that a major transcriptional transition occurs in distal limb buds between E9.5 and E10.5, coincident with the switch from an early phase continuation of the signature of trunk progenitors, related to the initial proximo distal specification, to a late intrinsic phase of development.

[Background]: The phalanges are the final skeletal elements to form in the vertebrate limb and their identity is regulated by signaling at the phalanx forming region (PFR) located at the tip of the developing digit ray. Here, we seek to explore the relationship between PFR activity and phalanx morphogenesis, which define the most distal limb skeletal elements, and signals associated with termination of limb outgrowth. [Results]: As Grem1 is extinguished in the distal chick limb mesoderm, the chondrogenesis marker Aggrecan is up-regulated in the metatarsals and phalanges. Fate mapping confirms that subridge mesoderm cells contribute to the metatarsal and phalanges when subridge Grem1 is down-regulated. Grem1 overexpression specifically blocks chick phalanx development by inhibiting PFR activity. PFR activity and digit development are also disrupted following overexpression of a Gli3 repressor, which results in Grem1 expression in the distal limb and downregulation of Bmpr1b. [Conclusions]: Based on expression and fate mapping studies, we propose that downregulation of Grem1 in the distal limb marks the transition from metatarsal to phalanx development. This suggests that downregulation of Grem1 in the distal limb mesoderm is necessary for phalanx development. Grem1 downregulation allows for full PFR activity and phalanx progenitor cell commitment to digit fate.

This is the peer reviewed version of the following article: I. Vayá, I. Andreu, E. Lence, C. González-Bello, M. Consuelo Cuquerella, M. Navarrete-Miguel, D. Roca-Sanjuán, M. A. Miranda, Chem. Eur. J. 2020, 26, 15922, which has been published in final form at https://doi.org/10.1002/chem.202001336. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] Lapatinib (LAP) is an anticancer drug, which is metabolized to theN- and O-dealkylated products (N-LAP andO-LAP, respectively). In view of the photosensitizing potential of related drugs, a complete experimental and theoretical study has been performed on LAP,N-LAP andO-LAP, both in solution and upon complexation with human serum albumin (HSA). In organic solvents, coplanar locally excited (LE) emissive states are generated; they rapidly evolve towards twisted intramolecular charge-transfer (ICT) states. By contrast, within HSA only LE states are detected. Accordingly, femtosecond transient absorption reveals a very fast switching (ca. 2 ps) from LE (lambda(max)=550 nm) to ICT states (lambda(max)=480 nm) in solution, whereas within HSA the LE species become stabilized and live much longer (up to the ns scale). Interestingly, molecular dynamics simulation studies confirm that the coplanar orientation is preferred for LAP (or to a lesser extentN-LAP) within HSA, explaining the experimental results.

John Francis Fallon, a widely respected developmental biologist, revered teacher and mentor, distinguished colleague, critical yet constructive editor, inspiring leader, devoted family man, and dear friend passed away on February 11, 2020. John was born in Boston, Massachusetts, on March 21, 1938, and he grew up in Massachusetts, Indiana, and California. He attended high school at Roosevelt Military Academy (named in honor of Theodore Roosevelt) in Aledo, Illinois, and he attended college at Marquette University in Milwaukee, Wisconsin, where he majored in philosophy and biology. At Marquette, John met two people who would shape his life: Elaine (nee Degnan), his wife for 57 years and the mother of his three children; and Professor John W. Saunders, Jr., who would determine John's future career choice by instilling in him a passion for scientific discovery, especially in the field of developmental biology. After receiving a PhD under Saunders' tutelage, John served 2 years in the US Army Service Corps before being recruited as an Assistant Professor to the University of Wisconsin, Madison, where he progressively advanced through the ranks. He remained at the University of Wisconsin throughout his career, with his retirement on December 31, 2009, being celebrated on April 15, 2010, with the John Fallon Symposium held in Madison in his honor.

"This is the peer reviewed version of the following article: Molins-Molina, Oscar, Roger Bresolí-Obach, Guillermo Garcia-Lainez, Inmaculada Andreu, Santi Nonell, Miguel A. Miranda, and M. Consuelo Jiménez. 2017. Singlet Oxygen Production and in Vitro Phototoxicity Studies on Fenofibrate, Mycophenolate Mofetil, Trifusal, and Their Active Metabolites. Journal of Physical Organic Chemistry 30 (9). Wiley: e3722. doi:10.1002/poc.3722, which has been published in final form at https://doi.org/10.1002/poc.3722. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.", [EN] Singlet oxygen photosensitization (studied by time-resolved near-infrared emission spectroscopy) and in vitro phototoxicity (by means of the 3T3 neutral red uptake assay) have been investigated for the prodrugs fenofibrate (FFB), mycophenolate mofetil (MMP), and trifusal (TFS) as well as for their active metabolites fenofibric acid (FFA), mycophenolic acid (MPA), and 2-hydroxy-4-(trifluoromethyl) benzoic acid (HTB). The results show that FFB and its active metabolite FFA generate O-1(2) with a quantum yield in the range 0.30 to 0.40 and show a photo-irritation factor (PIF) higher than 40. By contrast, MMP/MPA and TFS/HTB are not photoactive in the used assays. These results correlate well with the previously reported in vivo phototoxicity in treated patients.

[EN] Novel diastereomeric triads containing two naphthalene chromophores have been designed in which an electron-donating amine moiety is covalently integrated into the connecting bridge. Photophysical studies (steady-state and time-resolved fluorescence) in solvents of different polarity have been performed. A remarkable stereodifferentiation in the intramolecular fluorescence quenching was found in acetonitrile. Laser flash photolysis gave rise to naphthalene-derived radical cations, which were also quenched by the amine with an even higher degree of stereodifferentiation. The results are in agreement with thermodynamic estimations and indicate that photoinduced electron transfer (PET) is the main quenching pathway. Furthermore, theoretical calculations have allowed us to explain the experimentally observed stereodifferentiation in PET quenching.

[Background]: Precise temporal and spatial expression of the clustered Hox genes is essential for patterning the developing embryo. Temporal activation of Hox genes was shown to be cluster-autonomous. However, gene clustering appears dispensable for spatial colinear expression. Generally, a set of Hox genes expressed in a group of cells instructs these cells about their fate such that the differential expression of Hox genes results in morphological diversity. The spatial colinearity is considered to rely both on local and long-range cis regulation. [Results]: Here, we report on the global deregulation of HoxA and HoxD expression patterns upon inactivation of a subset of HOXA and HOXD proteins. [Conclusions]: Our data suggest the existence of a >self-regulation> mechanism, a process by which HOX proteins establish and/or maintain the spatial domains of the Hox gene family and we propose that the functionally dominant HOX proteins could contribute to generating the spatial parameters of Hox expression in a given tissue, i.e., HOX controlling the establishment of the ultimate HOX code.