Understanding XDP through imaging,pathology,and genetics

The X-linked dystonia-parkinsonism (XDP) is a severe progressive, adult-onset X-linked endemic disorder in Filipinos, which is characterized by dystonic movements that start in the third of fourth decade, and replaced by parkinsonism beyond the 10th year of illness. Understanding the pathophysiology of XDP and development of rational therapies will depend on observations from imaging pathological and genetic studies. In this paper we summarize the results of these studies on patients with XDP. The cranial magnetic resonance imaging shows hy-perintense putaminal rim in both dystonic and parkinsonian stages, and atrophy of the caudate head or putamen in the parkinsonian stage. Neuropathological findings show atrophy of the caudate nucleus and putamen, with mild to severe neuronal loss and gliosis. In the neostriatum, the dystonic phase of XDP shows the involvement of striosomes and matrix sparing, while the later, i.e., p[arkinsonian phase, shows matrix involvement as well. In the dystonic phase, the loss of striosomal inhibitory projections lead to disinhibition of nigral dopaminergic neurons, perhaps resulting in a hyperkinetic state; while in the parkinsonian phase, severe and critical reduction of matrix-based projection may result in extranigral parkinsonism. Genetic sequencing of the XDP critical region in Xq13.1 has revealed an SVA retronsposon insertion in an intron of TAF1. This may reduce neuron-specific expression of the TAF1 isoform in the caudade nucleus, and subsequently interfere with the transcription of many neuronal genes, including DRD2. Findings from imaging, pahtology, and genetics studies are gradually shedding light on the pathophysiology of XDP, which hopefully will lead to mare rational and directed therapies.

An update on research ethics in Asia / Journal of the ASEAN Federation of Endocrine Societies

There are many international guidelines that have been developed to ensure that the conduct of researches by countries, institutions and individuals are ethical. There are, however, unique opportunities as well as challenges in research in the ASEAN region which mandate not only adherence to these guidelines but which necessitate regional as well as individual country efforts to ensure that biomedical researches uphold the dignity, ensure safety and protect the rights of participants. Some of the challenges are: the widespread poverty or uneven distribution of resources in developing countries which cause patients to participate in clinical trials to avail of services that otherwise are inaccessible, lack of a research infrastructure that makes ethics review of protocols inadequate or slow, and lack of post-trial access to medications which have been tested in precisely the populations that need these drugs. The aim of this paper is to review the ethical challenges in health research encountered in Asia and to describe the regional efforts being undertaken to address them.