Nucleophile-Catalyzed Additions to Activated Triple Bonds. Protection of Lactams, Imides, and Nucleosides with MocVinyl and Related Groups

Additions of lactams, imides, (S)-4-benzyl-1,3-oxazolidin-2-one, 2-pyridone, pyrimidine-2,4-diones (AZT derivatives), or inosines to the electron-deficient triple bonds of methyl propynoate, tert-butyl propynoate, 3-butyn-2-one, N-propynoylmorpholine, or N-methoxy-N-methylpropynamide in the presence of many potential catalysts were examined. DABCO and, second, DMAP appeared to be the best (highest reaction rates and E/Z ratios), while RuCl3, RuClCp*(PPh3)2, AuCl, AuCl(PPh3), CuI, and Cu2(OTf)2 were incapable of catalyzing such additions. The groups incorporated (for example, the 2-(methoxycarbonyl)ethenyl group that we name MocVinyl) serve as protecting groups for the above-mentioned heterocyclic CONH or CONHCO moieties. Deprotections were accomplished via exchange with good nucleophiles: the 1-dodecanethiolate anion turned out to be the most general and efficient reagent, but in some particular cases other nucleophiles also worked (e.g., MocVinyl-inosines can be cleaved with succinimide anion). Some structural and mechanistic details have been accounted for with the help of DFT and MP2 calculations.

Two different epidemiological scenarios of border disease in the populations of Pyrenean chamois (Rupicapra p. pyrenaica) after the first disease outbreaks

Since 2001 several outbreaks of a new disease associated with Border disease virus (BDV) infection have caused important declines in Pyrenean chamois (Rupicapra pyrenaica) populations in the Pyrenees. The goal of this study was to analyze the post-outbreak BDV epidemiology in the first two areas affected by disease with the aim to establish if the infection has become endemic. We also investigated if BDV infected wild and domestic ruminants sharing habitat with chamois. Unexpectedly, we found different epidemiological scenarios in each population. Since the disease outbreaks, some chamois populations recuperated quickly, while others did not recover as expected. In chamois from the first areas, prevalence was high (73.47%) and constant throughout the whole study period and did not differ between chamois born before and after the BDV outbreak; in all, BDV was detected by RT-PCR in six chamois. In the other areas, prevalence was lower (52.79%) and decreased during the study period; as well, prevalence was significantly lower in chamois born after the disease outbreak. No BDV were detected in this population. A comparative virus neutralisation test performed with four BDV strains and one Bovine viral diarrhoea virus (BVDV) strain showed that all the chamois had BDV-specific antibodies. Pestivirus antibodies were detected in all the rest of analyzed species, with low prevalence values in wild ruminants and moderate values in domestic ruminants. No viruses were detected in these species. These results confirm the hypothesis that outbreaks of BDV infection only affect the Pyrenean chamois, although other wild ruminants can occasionally be infected. In conclusion, two different scenarios have appeared since the first border disease outbreaks in Pyrenean chamois: on the one hand frequent BDV circulation with possible negative impact on population dynamics in some areas and on the other, lack of virus circulation and quick recovery of the chamois population.

A prospective, randomized, triple-blind comparison of articaine and bupivacaine for maxillary infiltrations

Objectives: To compare the clinical anesthetic efficacy of 0.5% bupivacaine and 4% articaine (both with 1:200.000 adrenaline) for anterior maxillary infiltration in healthy volunteers. Material and methods: A triple-blind split-mouth randomized clinical trial was carried out in 20 volunteers. A supraperiosteal buccal injection of 0.9 ml of either solution at the apex of the lateral incisor was done in 2 appointments separated 2 weeks apart. The following outcome variables were measured: latency time, anesthetic efficacy (dental pulp, keratinized gingiva, alveolar mucosa and upper lip mucosa and tissue) and the duration of anesthetic effect. Hemodynamic parameters were monitored during the procedure. Results: Latency time recorded was similar for both anesthetic solutions (p>0.05). No statistically significant differences were found in terms of anesthetic efficacy for dental pulp, keratinized gingiva or alveolar mucosa. Articaine had a significant higher proportion of successful anesthesia at 10 minutes after infiltration in lip mucosa and lip skin (p=0.039). The duration of anesthesia was 336 minutes for bupivacaine and 167 minutes for articaine. (p<0.001). No significant hemodynamic alterations were noted during the procedure. Conclusions: Articaine and bupivacaine exhibited similar anesthetic efficacy for maxillary infiltrations. The duration of anesthesia was longer with the bupivacaine solution, but lip anesthesia was better with articaine