Meeting report: risk assessment of tamiflu use under pandemic conditions.

On 3 October 2007, 40 participants with diverse expertise attended the workshop Tamiflu and the Environment: Implications of Use under Pandemic Conditions to assess the potential human health impact and environmental hazards associated with use of Tamiflu during an influenza pandemic. Based on the identification and risk-ranking of knowledge gaps, the consensus was that oseltamivir ethylester-phosphate (OE-P) and oseltamivir carboxylate (OC) were unlikely to pose an ecotoxicologic hazard to freshwater organisms. OC in river water might hasten the generation of OC-resistance in wildfowl, but this possibility seems less likely than the potential disruption that could be posed by OC and other pharmaceuticals to the operation of sewage treatment plants.

The inferior boundary condition of a continuous cantilever beam model of the human spine.

The continuous cantilever beam model of the human spine usually assumes that the beam tangent at the inferior end of the structure is exactly perpendicular to the surface in which it is built into. The model used in this paper allows for realistic imperfections in the beam so that a small non-zero rotation is allowed at its inferior end. Such a model is used to investigate the lateral deformation of the muscle-relaxed spine as it supports asymmetrical loads in the frontal plane.

Recurrence of breast carcinoma following immediate reconstruction: a 13-year review.

To evaluate the effect of immediate reconstruction on the incidence, location, detection, and treatment of recurrent breast cancer, a review of 306 patients operated on according to a standard protocol during the 10-year period 1979 through 1988 was performed. Reconstruction techniques included submuscular implants (207), tissue expanders (84), and musculocutaneous flaps (15). During a minimum follow-up period of 3 years with a mean of 6.

Asymmetrical loads and lateral bending of the human spine.

The human spine is modelled as a cantilever-type beam column. Under the influence of static asymmetrical loads, muscle and low-back forces are predicted from a hypothetical but revealing model. Such forces produced by asymmetrical loads are much larger than for a corresponding symmetrical load.

Biomechanical simulations of scoliotic spinal deformity and correction.

A new approach to surgical correction of scoliosis has been advanced by us, in the form of simulation of the surgical correction system and technique. For this purpose, we developed a finite-element model of the spinal column (SFEM), applied tractions to it and determined the model stiffness so as to watch the actual spinal geometry. Having patient-simulated this SFEM, we applied to this SFEM corrective forces and determined the optimal set of forces to gain the best correction of the spinal deformity.

Lifting low-lying loads in the sagittal plane.

A simple geometrical model was employed to investigate various elementary techniques during static, sagittal plane lifts. Relationships between the various joint reaction forces were deduced. In particular, it was found that it is possible to simultaneously increase (or decrease) both knee and low back forces.

Continuous model of the human scoliotic spine.

The human scoliotic spine is mathematically modelled by employing the classical non-linear theory of curved beam-columns. A realistically representative muscle force system is included in the model. Scoliosis due to asymmetrical bi-lateral muscular contractions has been studied and arbitrary large displacements and curvatures are allowed.

Developmental and corrective biomechanics for scoliosis.

The developmental mechanism for scoliosis and its surgical correction are studied by modeling the spinal column as a curved nonlinear (large-deformation-sustaining) beam column to which are applied (a) muscle forces to simulate scoliosis development due to asymmetrical bilateral muscle contractions and (b) corrective forces to simulate the action of surgically implanted corrective systems. The two-dimensional model permits curvature in the frontal plane and can simulate and demonstrate the progression of a scoliotic curve from an initially straight configuration for various model parameter values. The calculation of the bonding moments is treated, and a simple algorithm for solving the model equations is presented.