Immunosuppressive properties of seminal plasma inhibit the recovery of infectious HIV from semen, and led to the view early in the pandemic that semen HIV was transmitted principally by infected semen cells. More recent studies have revealed significant titers of HIV RNA in seminal plasma, however, even from men receiving successful antiviral therapy. Thus, studies of infectious HIV in seminal plasma are important to understanding sexual transmission and response to therapy. The present studies were undertaken to determine whether seminal plasma immunosuppression is mediated by the induction of programmed cell death (PCD). Peripheral blood mononuclear cells (PBMCs) were cultured without or with phytohemagglutinin and seminal plasma from normal donors, or men postvasectomy, or seminal vesicle protein collected at surgery. PBMC survival was measured at 3, 6, and 18 hr of culture; cells were examined for evidence of PCD by uptake of the fluorescent dye YO-PRO, and for fragmented nuclear DNA by the TUNEL assay. Approximately 90% of PBMCs cultured with seminal plasma from intact or vasectomized men were lost during 18 hr of culture; seminal vesicle protein did not induce cell loss. PCD assays were positive for PBMCs exposed to the seminal plasma, and negative for PBMCs cultured with seminal vesicle protein. Serum was not required for PCD induction. A 3-hr pulse with seminal plasma was sufficient to initiate PCD. These findings indicate that PCD induction accounts for the cytotoxic properties of semen, that the PCD is not the result of semen amine oxidases, and either that substances produced by seminal vesicles only at ejaculation, or by the prostate, are responsible for PCD induction.
On 18 September, in a historic referendum, the people of Scotland voted by 55.3 per cent to 44.7 per cent to remain in the United Kingdom. This article provides an immediate response. It is inevitably provisional and broadbrush in character and cannot cover all of the varied and conflicting perspectives on the referendum and its consequences; it is just one man's view. Given the varied international readership of this journal, I shall assume little prior knowledge of politics and government in the United Kingdom or of its history. Citations have been kept to a minimum.
Brexit presents a major challenge to the territorial governance of the UK. Despite a major overhaul of territorial governance in 1999 when the current devolution schemes were created, and subsequent changes to those schemes, the territorial governance of the UK has not been stabilised. There remained a series of unresolved issues. Eventually, these issues would have to have been faced, but Brexit has not only forced them onto the agenda, it has done so in fraught political circumstances which make them harder to resolve. Brexit highlights already existing tensions in territorial governance, it also creates a new set of problems for the institutions and processes of territorial governance to deal with, including how to implement the changes that Brexit requires in the context of extensive devolution of power. This article, therefore, sets out the difficulties Brexit poses for territorial governance and considers the prospects for resolving them.
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