Objective This study investigated whether oral contraceptive use affects the incidence of complications (pain, trismus, dry socket) in women undergoing removal of impacted mandibular third molars. Patients and method Two hundred and sixty seven women, aged 17 -45 years, underwent removal of an impacted mandibular third molar. Eighty seven of the women were regular users of oral contraceptives. All patients were evaluated for postoperative pain, trismus and dry socket (localized alveolar osteitis). Results Mean trismus values (measured as maximum interincisal distance) were similar in the two groups of patients. Postoperative pain was significantly more frequent among women taking contraceptives, both on day 1 (30% of women taking contraceptives used analgesics, versus 11% of women not taking contraceptives, p < 0.001) and on day 5 (14% versus 5%, p = 0.024). Similarly, dry socket occurred more frequently among women taking contraceptives than among women not taking contraceptives (11% versus 4%, p = 0.017). Conclusions The results of this study support the view that oral contraceptive use favours the appearance of dry socket and postoperative pain after extraction, but has no effect on trismus.The removal of a mandibular third molar typically provokes pain, inflammation and trismus, as well as other complications of varying frequency. [1][2][3][4] Numerous studies have indicated that the incidence of complications after molar extraction is higher among women taking oral contraceptives, 5-12 although some authors have not detected any association. [13][14] The aim of the present study was to investigate the influence of oral contraceptive use on pain, trismus and dry socket (localized alveolar osteitis) after removal of a mandibular third molar.

Quantitative thermodynamic stability scales of organolithium compounds can be derived from measurements of tin-lithium exchange equilibria. A DeltaG(eq) scale of alpha-oxy- and alpha-aminoorganolithium compounds was established, and quantitative stabilization effects of O-alkyl, O-alkoxyalkyl, O-carbamoyl, N-carbamoyl, and O-carbonyl groups of the alpha-carbanion are presented. It has been found that an alpha-oxycarbanion is far better stabilized by a carbonyl group as the O-substituent than by an alkyl or alkoxyalkyl group, while the anion-stabilizing effects of the different O-carbonyl substituents are comparable. An N-carbamoyl group was found to have a somewhat higher stabilizing effect than its O-carbamoyl counterpart. NMR data are presented that show that benzylic N- or O-substituted carbanions have highly planarized structures where the negative charge is highly delocalized. The stability data obtained from the tin-lithium exchanges can be easily converted into "effective pK" data that are useful for predicting the acid-base behavior of this type of organolithium species.

Reaction of Me3SnLi with aromatic and heteroaromatic diesters proceeds through a fast stanna-Brook rearrangement that generates an stable bis-enolate which can be regioselectively alkylated and cyclized, in one step, to bicyclic compounds containing 6,5-, 6,6-, and 6,7-fused ring systems.

A DeltaG(eq) stability scale of secondary alpha-oxy-organolithium compounds was established from measurements of tin-lithium exchange equilibria in THF, and the quantitative effects of substituents at the anionic center on carbanion stability are presented. A new lead-lithium exchange equilibrium reaction was also investigated and shown to be a very useful alternative for the determination of the relative stability of the more sterically hindered organolithium compounds. Alkyl groups adversely affect the stability of organolithium compounds when attached to the carbon bearing the negative charge, but the extent of this effect is highly dependent on the nature of the rest of the substituents attached to the anionic center. Quantitative data on the stabilization imparted to organolithium compounds by Li-O and Li-N chelation have been determined for a variety of systems. The formation of four- and five-membered chelate rings leads to a considerable stabilization of the organolithium compound, while chelation through the formation of six-membered rings affords no extra stabilization to this type of organometallics. Multinuclear NMR experiments carried out on several alpha-oxy-organolithium compounds to determine their aggregation state are supportive of these species being monomers in THF solution.

In our quest for HIV-1 protease inhibitors that are not affected by the V82A resistance mutation, we have synthesized and tested a second generation set of C2-symmetric HIV-1 protease inhibitors that contain a cyclohexane group at P1 and/or P1'. The binding affinity results indicate that these compounds have an improved response to the appearance of the V82A mutation than the parent compound. The X-ray structure of one of these compounds with the V82A HIV-1 PR variant provides the structural rationale for the better resistance profile of these compounds. Moreover, scrutiny of the X-ray structure suggests that the ring of the Cha side chain might be in a boat rather than in the chair conformation, a result supported by molecular dynamics simulations.