Local and global cooperativity in the human alpha-lactalbumin molten globule

NMR spectroscopy has been used to follow the urea-induced unfolding of the low pH molten globule states of a single-disulfide variant of human alpha-lactalbumin ([28-111] alpha-LA) and of two mutants, each with a single proline substitution in a helix. [28-111] alpha-LA forms a molten globule very similar to that formed by the wild-type four-disulfide protein, and this variant has been used as a model for the alpha-lactalbumin (alpha-LA) molten globule in a number of studies. The urea-induced unfolding behavior of [28-111] alpha-LA is similar to that of the four-disulfide form of the protein, except that [28-111] alpha-LA is less stable and has greater cooperativity in the loss of different elements of structure. For one mutant, L11P, the helix containing the mutation is highly destabilized such that it is completely unfolded even in the absence of urea. By contrast, for the other mutant, Q117P, the helix containing the mutation retains its compact structure. Both mutations, however, show significant long-range destabilization of the overall fold showing that the molten globule state has a degree of global cooperativity. The results reveal that different permutations of three of the four major alpha-helices of the protein can form a stable, locally cooperative, compact structural core. Taken together, these findings demonstrate that the molten globule state of alpha-LA is an ensemble of conformations, with different subsets of structures linked by a range of long-range interactions.     

Total Intracardiac Repair of the Adult Cyanotic Tetralogy of Fallot: Clinical Experience and Late Follow-up

Twenty-seven adult patients with the cyanotic type of tetralogy of Fallot had total intracardiac repair during the past five years at the Toronto General Hospital. Twenty-one of 27 patients (77%) had had a previous shunting operation performed five to 21 years prior to the total intracardiac repair. Seventeen of 21 (81%) of these anastomoses were patent at the time of the total intracardiac repair. The hospital mortality was 11% and was attributable to hemorrhage - a well-recognized problem in adult tetralogy, due to excessive collateral circulation. All 24 surviving patients followéd up from six months to five years showed marked clinical improvement, with disappearance of the cyanosis and reduction in acne and clubbing. Permanent heart block has not occurred. Late hemodynamic studies showed a significant persisting shunt in two out of 16 or 12%.     

Bill morphology reflects adaptation to a fibrous diet in the kākāpō (Strigops: Psittaciformes)

We describe the upper portion of the bill sheath (rhinotheca) of the kākāpō (Strigops habroptilus) from three adult female specimens. The external buccal surface of the rhinotheca is deeply concave with a prominent palatal stop and hardened chevrons creating a ‘milling apparatus’ that the kākāpō uses to grind food. The palatal stop presents a working face of 40–50?mm². The internal surface of the rhinotheca mirrors the overlying premaxilla and provides a distinct thickened abutment consistent with resistance against the increased workload of the mandibles (gnathotheca) due to the kākāpō’s fibrous diet and chewing style. Along the midline, the rhinotheca at the abutment is up to 5.6?mm thick, compared with as thin as 2.1?mm elsewhere on the midline. The closely related Nestor parrots have less developed palatal stops, chevrons and abutments on their rhinothecas consistent with their lower preference for fibrous plant material. The form of the rhinotheca agrees with the kākāpō’s feeding ecology as a generalist herbivore that grinds locally available fibrous material to assist digestion.     

Partnerships for better mental health worldwide: WPA recommendations on best practices in working with service users and family carers

WPA President M. Maj established the Task Force on Best Practice in Working with Service Users and Carers in 2008, chaired by H. Herrman. The Task Force had the remit to create recommendations for the international mental health community on how to develop successful partnership working. The work began with a review of literature on service user and carer involvement and partnership. This set out a range of considerations for good practice, including choice of appropriate terminology, clarifying the partnership process and identifying and reducing barriers to partnership working. Based on the literature review and on the shared knowledge in the Task Force, a set of ten recommendations for good practice was developed. These recommendations were the basis for a worldwide consultation of stakeholders with expertise as service users, families and carers, and the WPA Board and Council. The results showed a strong consensus across the international mental health community on the ten recommendations, with the strongest agreement coming from service users and carers. This general consensus gives a basis for Task Force plans to seek support for activities to promote shared work worldwide to identify best practice examples and create a resource to assist others to begin successful collaboration.