Highly enantioselective hydrogenation of styrenes directed by 2'-hydroxyl groups.

A new synthetic strategy that turns styrene-type olefins into excellent substrates for Rh-catalyzed asymmetric hydrogenation by installing a 2'-hydroxyl substituent is described. This methodology accommodates trisubstituted olefinic substrates in various E/Z mixtures, leading to valuable benzylic chiral compounds including (R)-tolterodine. It is also demonstrated that the 2'-hydroxyl groups could be readily removed in high yield without loss of ee from the products. Thus, this technology represents an attractive alternative to the Ir(P-N) catalyst system for the asymmetric hydrogenation of unfunctionalized olefins.

Risk factors for anal sphincter disruption during child birth.

BACKGROUND AND AIMS: The objective of our study was to analyse the risk factors in a cohort of women who suffered anal sphincter disruption (third-degree tear) and compare the results with a similar cohort of women who underwent an uncomplicated vaginal delivery (without a clinically detectable laceration) during the same period. MATERIALS AND METHODS: A retrospective analysis was carried out on 54 women (group 1) who suffered a third-degree tear and 71 women who had undergone uncomplicated vaginal delivery during the same period (group 2). The risk factors considered were forceps delivery, parity, second stage of labour longer than 1 h, episiotomy, birth weight over 4 kg, gestational age and maternal age at delivery. The Cleveland Incontinence Score was completed. RESULTS: Multiple logistic regression analysis of obstetric risk factors for third-degree perineal tear indicated forceps delivery (p = 0.0001), primiparity (p = 0.004), foetal birth weight over 4 kg (p = 0.030) and delay in the second stage of labour (p = 0.031) to be significant risk factors for a third-degree tear. Mediolateral episiotomy was shown to be a significant protective factor (p = 0.0001). Gestational age and the maternal age at delivery (p = 0.340) were not shown to be significant risk factors (p = 0.336). CONCLUSION: Primary prevention and identification of women with risk factors is recommended. In some cases, counselling regarding the potential risks and benefits of both vaginal and caesarean delivery may be appropriate.

Long-term anal continence and quality of life following postpartum anal sphincter injury.

OBJECTIVE: Anal incontinence occurs as a result of damage to pelvic floor and the anal sphincter. In women, vaginal delivery has been recognized as the primary cause. To date, figures quoted for overt third degree anal sphincter tear vary between 0% and 26.9% of all vaginal deliveries and the prevalence of anal incontinence following primary repair vary between 15% and 61%. Our aim was to analyse the long-term (minimum 10 years post primary repair) anorectal function and quality of life in a cohort of women who suffered a third degree tear (Group 1) and compare the results with a cohort of women who underwent an uncomplicated vaginal delivery (Group 2) or an elective caesarean delivery (Group 3). METHOD: In all, 107 patients who suffered a third degree tear between 1981 and 1993 were contacted with a validated questionnaire. The two control groups comprised of 125 patients in each category. Those who responded to the questionnaire were invited for anorectal physiology studies and endoanal ultrasound. RESULTS: Of the total number contacted, 54, 71 and 54 women from the three groups returned the completed questionnaire. In the three groups, a total of 28 (53%), 13 (19%) and six (11%) complained of anal incontinence (P < 0.0001) respectively. Comparison of quality of life scores between the groups showed a poorer quality of life in those who suffered a tear (P < 0.0001). In addition, in spite of primary repair, 13 (59%) patients in group 1 showed a persistent sphincter defect compared to one (4%) occult defect in Group 2 and none in Group 3. CONCLUSION: Our study indicates that long-term results of primary repair are not encouraging. It therefore emphasizes the importance of primary prevention and preventing further sphincter damage in those who have already suffered an injury (during subsequent deliveries).