No abstract

Videodefaecography allows identification of three different types of rectoceles: type I or digitiform rectocele, type II or rectocele with a lax rectovaginal septum, an anterior mucosal prolapse and a deep pouch of Douglas, and a type III in which a rectocele is associated with intussusception or even rectal prolapse. Furthermore, videodefaecography gave information on functional mechanisms resulting in incontinence or constipation. Surgical treatment should be tailored to the radiological and clinical findings: endoanal approach in type I, posterior colpomyorhaphy in type II and double abdomino-vaginal approach in type III. One hundred and fifty cases were prospectively treated according to this policy. Recurrence occurred in one out of 150 cases (1.3%). Incontinence was cured in 93% and constipation in 88%.

Two distinct, rigorous views of cryptography have developed over the years, in two mostly separate communities. One of the views relies on a simple but effective formal approach; the other, on a detailed computational model that considers issues of complexity and probability. There is an uncomfortable and interesting gap between these two approaches to cryptography. This paper starts to bridge the gap, by providing a computational justification for a formal treatment of encryption.

The photochemical denitrogenation of the cyclopentene-annelated DBH-type azoalkanes 1 has been examined in solution as a function of bridgehead substitution and temperature. For all derivatives, namely, the unsubstituted 1a(H/H), monomethyl 1b(Me/H) dimethyl 1c(Me/Me), monophenyl 1d(Ph/H), and diphenyl 1e(Ph/Ph), the temperature-dependent ratio of syn and anti housanes 2 provides experimental support for a competition between the singlet (high temperature) and triplet (low temperature) reaction channels in the direct photolysis. The syn/anti ratio of the housanes 2 depends on the extent and type of bridgehead substitution; the amount of the anti diastereomer (retention) follows the order Ph > Me > H, and double substitution is more effective than single. This stereochemical memory is interpreted in terms of the mass effect (inertia) of the substituents and steric interaction (size) between the substituents at the bridgehead and the methylene bridge during the deazetation step of the transient diazenyl diradical conformations (1)DZ (exo-ax) and (1)DZ (exo-eq). These conformers are impulsively generated upon decay of the (1)(n,pi)-excited azoalkane, a trajectory assessed through computational work. The new mechanistic feature disclosed by the unprecedented anti stereoselectivity (retention) is the intervention of a puckered 1,3-cyclopentanediyl singlet diradical (1)DR as product bifurcation step, whose conformational relaxation to the planar species (loss of stereochemical memory) is encumbered by bridgehead substitution.

Thirty-nine patients with factor XI deficiency were diagnosed in our general hospital, which serves all the French Basque Country (about 290 000 inhabitants), between 1985 and 1995. Biological and clinical data of these cases are reported herein. Factor XI deficiency seems significantly more frequent in Basques than in the other non-Ashkenazi populations. Molecular studies should be performed for typing these cases in the view of population genetics.