Iodine-123 metaiodobenzylguanidine scintigraphic assessment of the transplanted human heart: Evidence for late reinnervation

Objectives.This study attempted to determine whether cardiac sympathetic reinnervation occurs late after orthotopic heart transplantation.Background.Metaiodobenzylguanidine (MIBG) is taken up by myocardial sympathetic nerves. Iodine-123 (I-123) MIBG cardiac uptake reflects intact myocardial sympathetic innervation of the heart. Cardiac transplant recipients do not demonstrate I-123 MIBG cardiac uptake when studied <6 months from transplantation. However, physiologic and biochemical studies suggest that sympathetic reinnervation of the heart can occur >1 year after transplantation.Methods.We performed serial cardiac I-123 MIBG imaging in 23 cardiac transplant recipients early (<-1 year) and late (>1 year) after operation. In 16 subjects transmyocardial norepinephrine release was measured late after transplantation.Results.No subject had visible I-123 MIBG uptake on imaging <1 year after transplantation. However, 11 (48%) of 23 subjects developed visible cardiac I-123 MIBG uptake 1 to 2 years after transplantation. Only 3 (25%) of 12 subjects with a pretransplantation diagnosis of idiopathic cardiomyopathy demonstrated I-123 MIBG uptake compared with 8 (73%) of 11 with a pretransplantation diagnosis of ischemic or rheumatic heart disease (p = 0.04). All 10 subjects with a net myocardial release of norepinephrine had cardiac I-123 MIBG uptake; all 6 subjects without a net release of norepinephrine had no cardiac I-123 MIBG uptake.Conclusions.Sympathetic reinnervation of the transplanted human heart can occur >1 year after operation, as assessed by I-123 MIBG imaging and the transmyocardial release of norepinephrine. Reinnervation is less likely to occur in patients with a pretransplantation diagnosis of idiopathic cardiomyopathy than in those with other etiologies of congestive heart failure

Diffusion of e-mail: an organisational learning perspective

Current research has gone beyond technical aspects to consider the social effects of E-mail on organisations. This paper follows the trend by considering organisational learning aspects. In particular, the paper explores the way in which organisation members learn to exploit E-mail for political manipulation. The paper is based on a case study which describes the introduction of E-mail to a university community. The case study demonstrates that despite heavy investment in the project, initial enthusiasm, and top management support, some employees chose to use E-mail to stage a rebellion against top management. This was eventually followed by management curtailing users' access to E-mail. The discussion focuses on how organisational learning concepts can explain the case events, concluding with theoretical and practical implications

Getting International Students to Speak Up

They just sit there and do not say anything. I am not sure that they even prepare. No, they prepare. I know that because their written work is often quite insightful. I just wish that they would speak up in class discussion. Well, I have tried, but they have nothing to say ..

Toward a network sociality

This article explores some current transformations of the social. It argues for a shift from a model of sociality based on community towards a network sociality. This shift is particularly visible in urban spaces and in the cultural industries. However, it seems to become paradigmatic more widely of the information society. The article is to be read as a cultural hypothesis. In the first part I introduce some examples that document the rise of a network sociality. Most of these examples are drawn from a two-year ethnographic study of London's new media. The second part consists of a critique of some theoretical accounts of contemporary transformations of sociality. The third part is an attempt to outline the concept of network sociality. It is a form of sociality that is ephemeral but intense, it is informational and technological, it combines work and play, it is disembedded and generic, and it emerges in the context of individualization