Asymmetric requirement of Dpp/BMP morphogen dispersal in the Drosophila wing disc

How morphogen gradients control patterning and growth in developing tissues remains largely unknown due to lack of tools manipulating morphogen gradients. Here, we generate two membrane-tethered protein binders that manipulate different aspects of Decapentaplegic (Dpp), a morphogen required for overall patterning and growth of the Drosophila wing. One is “HA trap” based on a single-chain variable fragment (scFv) against the HA tag that traps HA-Dpp to mainly block its dispersal, the other is “Dpp trap” based on a Designed Ankyrin Repeat Protein (DARPin) against Dpp that traps Dpp to block both its dispersal and signaling. Using these tools, we found that, while posterior patterning and growth require Dpp dispersal, anterior patterning and growth largely proceed without Dpp dispersal. We show that dpp transcriptional refinement from an initially uniform to a localized expression and persistent signaling in transient dpp source cells render the anterior compartment robust against the absence of Dpp dispersal. Furthermore, despite a critical requirement of dpp for the overall wing growth, neither Dpp dispersal nor direct signaling is critical for lateral wing growth after wing pouch specification. These results challenge the long-standing dogma that Dpp dispersal is strictly required to control and coordinate overall wing patterning and growth.

The Patellar Resurfacing in Total Knee Prosthesis: Indications for Bone Stock and Patellar Morphology

The patellar resurfacing is still a controversial and unresolved problem. The choice to use the patellar resurfacing in the total knee prosthesis (TKP) is decided by the surgeon's experience; he analyzes the thickness, the shape, consumption of the surface and he chooses the use of patellar resurfacing or to limit itself to cheiloplasty, denervation, or often to the release of the lateral wing ligament. He also assesses the metabolic state of the bone linked to Osteoporosis and the potential fragility of the joint and kneecap in particular. Bone loss after total knee arthroplasty (TKP) may lead to periprosthetic fractures that are associated with significant costs (morbidity, economic, etc.) and pose a challenge to operative fixation. The literature doesn't express a definitive judgment on the two options, since the results can be overlapped on average. Each option has advantages and disadvantages to be considered in the overall balance of the patellar operation. In reality, however, this technical choice requires more consolidated decision-making criteria so as to minimize the incidence of post-surgical femoral-patellar pain syndrome, the second cause of failure, which frequently leads to revision of the implant. The balance between experience and evidence can be a compromise in the choice of surgery. The experience documented in the literature must identify the parameters capable of constructing an algorithm aimed not only at the secondary resurfacing rate, but at the overall clinical evaluation. This has implications also for the rehabilitation of these patients after surgery.

REVISION OF MEZIA (MALPIGHIACEAE)

The Neotropical genus Mezia (Malpighiaceae) comprises 15 species of lianas (except M. huberi W.R.Anderson, a shrub or small tree). All have multibranched, densely brown-sericeous inflorescences with the ultimate unit a 4-flowered umbel of bilaterally symmetrical flowers. The distinctive pair of large cymbiform bracteoles subtends a rudimentary pedicel and encloses the floral bud. The flowers contain elongate sepals, the lateral four biglandular, yellow petals, the posterior often splotched with red, a heteromorphic androecium, and a tricarpellate gynoecium. The three styles are all free; the posterior pair is lyrate in five species but erect in the others. The samaras have an orbicular to oblate lateral wing and a much smaller dorsal wing; in most species, additional winglets and/or crests are present between the lateral and dorsal wings. Only Mezia mariposa W.R.Anderson has butterfly-shaped samaras lacking additional ornamentation. Four new species are proposed: Mezia andersonii C.E.Anderson, M. bahiana C.E.Anderson, M. fanshawei C.E.Anderson and M. sericea C.E.Anderson. One variety is elevated to species level and provided with a new name, Mezia peruviana C.E.Anderson; a lectotype is chosen for Diplopterys involuta var. ovata Nied. Full descriptions and synonymies are provided, as well as a distribution map. All species are illustrated.