A comprehensive approach to long-standing facial paralysis based on lengthening temporalis myoplasty

Long-standing peripheral monolateral facial paralysis in the adult has challenged otolaryngologists, neurologists and plastic surgeons for centuries. Notwithstanding, the ultimate goal of normality of the paralyzed hemi-face with symmetry at rest, and the achievement of a spontaneous symmetrical smile with corneal protection, has not been fully reached. At the beginning of the 20(th) century, the main options were neural reconstructions including accessory to facial nerve transfer and hypoglossal to facial nerve crossover. In the first half of the 20(th) century, various techniques for static correction with autologous temporalis muscle and fascia grafts were proposed as the techniques of Gillies (1934) and McLaughlin (1949). Cross-facial nerve grafts have been performed since the beginning of the 1970s often with the attempt to transplant free-muscle to restore active movements. However, these transplants were non-vascularized, and further evaluations revealed central fibrosis and minimal return of function. A major step was taken in the second half of the 1970s, with the introduction of microneurovascular muscle transfer in facial reanimation, which, often combined in two steps with a cross-facial nerve graft, has become the most popular option for the comprehensive treatment of long-standing facial paralysis. In the second half of the 1990s in France, a regional muscle transfer technique with the definite advantages of being one-step, technically easier and relatively fast, namely lengthening temporalis myoplasty, acquired popularity and consensus among surgeons treating facial paralysis. A total of 111 patients with facial paralysis were treated in Caen between 1997 and 2005 by a single surgeon who developed 2 variants of the technique (V1, V2), each with its advantages and disadvantages, but both based on the same anatomo-functional background and aim, which is transfer of the temporalis muscle tendon on the coronoid process to the lips. For a comprehensive treatment of the paralysis, the eyelids are usually managed by Paul Tessier's technique to lengthen the levator muscle of the upper eyelid by aponeurosis interposition, combined with external blepharorrhaphy with Krastinova-Lolov's technique. Facial reanimation using lengthening temporalis myoplasty is a dynamic procedure that has its roots in the techniques of Gillies and McLaughlin. This method is a true lengthening myoplasty procedure using no intermediate grafts. In general, the results with a 1-stage combination of lengthening temporalis myoplasty and static correction of the lagophthalmos appear comparable with the major series in the literature using free microneurovascular transfers combined with cross-facial nerve grafts for longstanding peripheral monolateral facial paralysis. The obvious advantages of temporalis elongation myoplasty consist in its technical ease, a single step, low incidence of complications and markedly reduced operating time

Styrene, an Unpalatable Substrate with Complex Regulatory Networks

Styrene, a volatile organic compound (VOC), is an important industrial material involved in the production of plastic, synthetic rubber and resin, insulation and other industrial materials containing molecules such as polystyrene, butadiene-styrene latex, styrene copolymers and unsaturated polyester resins. Styrene exposure may cause contact-based skin inflammation, irritation of eyes, nose and respiratory tract. Neurological effects such as alterations in vision, hearing loss and longer reaction times, have been associated with styrene exposure in the workplace. In addition, styrene oxide may act as an established mutagen and carcinogen (www.epa.gov/chemfact/styre-sd.pdf). It has been reported that, in 2002, 22,323 tons of styrene were released to the environment (82), in spite of the US Clean Air Act mandate on reduction in the volume of allowable styrene emission (www.epa.gov/chemfact/styre-sd.pdf). Among a variety of emerging air pollution technologies, biofiltration is an attractive option for the treatment of VOCs, because it is cost-effective and does not generate secondary contaminants (45). Moreover, microbial biodegradation is the major route for the removal of non-aqueous compounds from soils. Styrene is also naturally present in non polluted environments, since it derives from fungal decarboxylation of cinnamic acid (90). Therefore it is not surprising that microorganisms of different families have been found to be able to degrade this compound (31). The promising results obtained in the removal of styrene from contaminated waste-gases by biofiltration (5, 39, 103) have led to an increasing attention to the regulatory mechanisms underlying styrene degradation, with the aim to improve bioremediation processes. Despite the diffusion in nature of this degradative capability, only few strains, mainly belonging to the Pseudomonas genus, have been characterized (66). This chapter is focused on the up-to-now discovered regulatory mechanisms underlying the expression of the styrene-catabolism genes. Moreover, open questions on environmental and metabolic constrains that govern styrene degradation are discussed. Biotechnological relevance of styrene-degrading strains in fine chemicals production and bioremediation processes is not examined here. Main topics on these application fields have recently been reviewed by Dobson and co-workers (66)