Synthesis of dihydronaphthofurandiones and dihydrofuroquinolinediones with trypanocidal activity and analysis of their stereoelectronic properties

The synthesis of dihydronaphthofurandione and dihydrofuroquinolinedione derivatives 4-11 was performed through Diels-Alder reactions of dihydrobenzofurandione 1 with several carbodienes and acrolein N,N-dimethylhydrazone. Then, the use of 5-bromobenzofurandione 2 toward 1,3-pentadiene and the 1-azadiene afforded quinones 6 and 11 with a total regioselectivity. All the prepared quinones were tested for trypanocidal activity in vitro against Trypanosoma epimastigotes, Tulahuen strain. Among the tested compounds, the furoquinolinediones 10 and 11 have shown potent trypanocidal activities but, only the 1,5-regioisomer (11) was found active as a redox cycling agent. Calculation of their stereoelectronic properties by the density-functional theory method provided a new insight for the trypanocidal activity of these heterocyclic quinones.     

LIMK1 regulates Golgi dynamics, traffic of Golgi-derived vesicles, and process extension in primary cultured neurons

In this study, we examined the subcellular distribution and functions of LIMK1 in developing neurons. Confocal microscopy, subcellular fractionation, and expression of several epitope-tagged LIMK1 constructs revealed that LIMK1 is enriched in the Golgi apparatus and growth cones, with the LIM domain required for Golgi localization and the PDZ domain for its presence at neuritic tips. Overexpression of wild-type LIMK1 suppresses the formation of trans-Golgi derived tubules, and prevents cytochalasin D-induced Golgi fragmentation, whereas that of a kinase-defective mutant has the opposite effect. Transfection of wild-type LIMK1 accelerates axon formation and enhances the accumulation of Par3/Par6, insulin-like growth factor (IGF)1 receptors, and neural cell adhesion molecule (NCAM) at growth cones, while inhibiting the Golgi export of synaptophysin-containing vesicles. These effects were dependent on the Golgi localization of LIMK1, paralleled by an increase in cofilin phosphorylation and phalloidin staining in the region of the Golgi apparatus, and prevented by coexpression of constitutive active cofilin. The long-term overexpression of LIMK1 produces growth cone collapse and axon retraction, an effect that is dependent on its growth cone localization. Together, our results suggest an important role for LIMK1 in axon formation that is related with its ability to regulate Golgi dynamics, membrane traffic, and actin cytoskeletal organization.     

Synthesis and in vitro trypanocide activity of several polycyclic drimane-quinone derivatives

The Diels-Alder reaction between two polygodial-derived dienes and simple quinones to yield substituted naphtho- and anthraquinones, is described. The in vitro trypanocide activity for the series was determined. Two of the new compounds showed an activity ten and two times higher, respectively, than nifurtimox and benznidazole, the medicines of choice for the treatment of the acute Chagas' disease.     

Further evaluation of amniotic membrane banking for transplantation in ocular surface diseases

Objective: To define the best conditions foramniotic membrane preparation, storage and banking in its use for cornealreconstruction.Methods: Amniotic membrane pieces were prepared understerile conditions from placentas selected on the basis of donor medical andsocial history, serology, microbiological tests and histology. The pieces werekept at –140 °C but before grafting they werethawed and stored at 4 °C in RPMI medium, to have apreparation usable within 72 h. This procedure was validatedby testing its therapeutic effectiveness in 25 patients 13 of which had cornealulcers of various origin, 3 had sequelae of herpes simplex keratitis, 3 bandkeratopathy and 6 corneal stem cell deficiency due to chemical or thermalburns.Results: The preparation showed appreciableanti-inflammatory and analgesic effects. In the absence of corneal stem celldeficiency a stable re-epithelialisation was achieved in 15 out of 19 patients.When the limbus was lesioned, the amniotic membrane decreased vascularizationand increased the number of corneal epithelial cells only in 1 of the 6patients. No adverse reactions attributable to the tissue were recorded.Conclusions: A ready-to-use amniotic membrane preparationstored at 4 °C after cryopreservation has been tested incorneal reconstruction. Like the amniotic membrane thawed immediately beforegrafting, this preparation displayed full therapeutic effect in epithelialdefects with stromal ulceration but without severe limbal stem cell deficiency.In two years banking activity 463 pieces of the preparation were successfullydistributed to 90 Italian hospitals.