A marginal likelihood approach to fitting the proportional hazards model to interval censored or grouped data is proposed;this approach maximises a likelihood that is the sum over al rankings of the data that are cons...
详细信息
A marginal likelihood approach to fitting the proportional hazards model to interval censored or grouped data is proposed;this approach maximises a likelihood that is the sum over al rankings of the data that are consistent with the observed censoring intervals. As in the usual proportional hazards model, the method does not require specification of the baseline hazard function. The score equations determining the maximum marginal likelihood estimator can be written as the expected value of the score of the usual proportional hazards model, with respect to a certain distribution of rankings. A Gibbs sampling scheme is given to generate rankings from this distribution, and stochastic approximation is used to solve the score equations. Simulation results under various censoring schemes give-point estimates that are close to estimates obtained using actual failure times.
Recently, a HIV-dependent upmodulation of the p75 tumour necrosis factor receptor (TNFr75) was observed using latently-infected OM-10.1 promyelocytes;although the participation of TNFr75 in HIV-1 activation remained u...
详细信息
Recently, a HIV-dependent upmodulation of the p75 tumour necrosis factor receptor (TNFr75) was observed using latently-infected OM-10.1 promyelocytes;although the participation of TNFr75 in HIV-1 activation remained undefined, Here, using receptor cross-linking by agonistic antibodies, no direct HIV-1 activation via TNFr75 was observed, Signalling via the p55 tumour necrosis factor receptor (TNFr55) accounted for the full extent of HIV-1 activation in OM-10.1 cultures. However, in tumour necrosis factor alpha (TNF-alpha) dose titration experiments, antibody blockade of TNFr75 decreased the dose response markedly, indicating a ligand passing function, TNFr75 blockade did not alter the dose response to agonistic TNFr55 antibody induction;verifying that the effect on the TNF-alpha dose response was not due to negative signalling or cytolysis, These results demonstrate that, although not directly involved in signal transduction resulting in HIV-1 activation, TNFr75 can serve a critical ligand passing function and permit continued HIV-1 expression during limited TNF-alpha availability. (C) 1996 Academic Press Limited
Background. The ethnic and geographical variations of aids prevalence among Injection drug users (IDU) have highlighted the need to understand the role of the relevant rIsk factors in specific subpopulatlons of IDU. I...
详细信息
The book includes chapters on the epidemiology, treatment, and prevention of HIV, as well as several chapters that discuss in detail specific provincial- and national-level programs to control and treat HIV. It chroni...
详细信息
ISBN:
(数字)9789811385186
ISBN:
(纸本)9789811385179;9789811385209
The book includes chapters on the epidemiology, treatment, and prevention of HIV, as well as several chapters that discuss in detail specific provincial- and national-level programs to control and treat HIV. It chronicles the Chinese government’s amazing about-face, as it replaced underfunded, non-evidence based policy decisions with successful, science-based approaches to disease control and prevention, including the adoption of once controversial needle-exchange programs and the establishment of a national HIV/aids data registry. It measures the success of national policy decisions, the implementation of treatment policies, and discusses the difficulty of accessing high-risk communities, including people who inject drugs, sex workers, and men who have sex with men – groups not easy to reach, study, engage in prevention programs, or treatment, for fear of stigmatization and loss of social status. Further, it documents the spread of HIV to other provinces, and the tragedy that befell repeat plasma donors in Henan and other poor provinces, where reused or improperly sterilized lab equipment caused some villages to have epidemic-level incidence rates. This book represents a positive contribution to the field of aids research, making vital, new information available to an interested readership.
暂无评论