DNA synthesis in scrapie-affected mouse brain

Ethics in prion disease

This paper is intended to discuss some of the scientific and ethical issues that are created by increased research efforts towards earlier diagnosis, as well as to treatment of, human prion diseases (and related dementias), including the resulting consequences for individuals, their families, and society. Most patients with prion disease currently are diagnosed when they are about 2/3 of the way through their disease course (Geschwind et al., 2010a; Paterson et al., 2012b), when the disease has progressed so far that even treatments that stop the disease process would probably have little benefit. Although there are currently no treatments available for prion diseases, we and others have realized that we must diagnose patients earlier and with greater accuracy so that future treatments have hope of success. As approximately 15% of prion diseases have a autosomal dominant genetic etiology, this further adds to the complexity of ethical issues, particularly regarding when to conduct genetic testing, release of genetic results, and when or if to implement experimental therapies. Human prion diseases are both infectious and transmissible; great care is required to balance the needs of the family and individual with both public health needs and strained hospital budgets. It is essential to proactively examine and address the ethical issues involved, as well as to define and in turn provide best standards of care.

Essential role of the N-terminal region of TFII-I in viability and behavior

Background

GTF2I codes for a general intrinsic transcription factor and calcium channel regulator TFII-I, with high and ubiquitous expression, and a strong candidate for involvement in the morphological and neuro-developmental anomalies of the Williams-Beuren syndrome (WBS). WBS is a genetic disorder due to a recurring deletion of about 1,55-1,83 Mb containing 25-28 genes in chromosome band 7q11.23 including GTF2I. Completed homozygous loss of either the Gtf2i or Gtf2ird1 function in mice provided additional evidence for the involvement of both genes in the craniofacial and cognitive phenotype. Unfortunately nothing is now about the behavioral characterization of heterozygous mice.

Methods

By gene targeting we have generated a mutant mice with a deletion of the first 140 amino-acids of TFII-I. mRNA and protein expression analysis were used to document the effect of the study deletion. We performed behavioral characterization of heterozygous mutant mice to document in vivo implications of TFII-I in the cognitive profile of WBS patients.

Results

Homozygous and heterozygous mutant mice exhibit craniofacial alterations, most clearly represented in homozygous condition. Behavioral test demonstrate that heterozygous mutant mice exhibit some neurobehavioral alterations and hyperacusis or odynacusis that could be associated with specific features of WBS phenotype. Homozygous mutant mice present highly compromised embryonic viability and fertility. Regarding cellular model, we documented a retarded growth in heterozygous MEFs respect to homozygous or wild-type MEFs.

Conclusion

Our data confirm that, although additive effects of haploinsufficiency at several genes may contribute to the full craniofacial or neurocognitive features of WBS, correct expression of GTF2I is one of the main players. In addition, these findings show that the deletion of the fist 140 amino-acids of TFII-I altered it correct function leading to a clear phenotype, at both levels, at the cellular model and at the in vivo model.

Creutzfeldt-Jakob disease and the eye. I. Background and patient management

This article attempts to summarise our current understanding of TSEs as they affect man. Specific aspects relevant to ophthalmological practice, in particular the management of patients in day-to-day clinical practice and with respect to corneal transplantation, have been discussed. In the companion article we discuss the specific ophthalmic and neuro-ophthalmic features of these diseases.

Transforming genes and gene products of polyoma and SV40

The small DNA-containing viruses, SV40 and polyoma, transform cells in vitro and induce tumors in vivo. For both viruses two genes required for transformation have been found. The genes required for transformation are also involved in productive infection. Although the two viruses are similar in their effects on cells, the organization of the transforming genes and gene products is different. The purpose of this review is to compare what is known about the biology and the biochemistry of the early regions of the two viruses. The genetic and biochemical studies defining the sequences important for transformation will be reviewed. Then, the products of the transforming genes, called T antigens, will be discussed in detail. There is a substantial body of descriptive information on those products, and studies on the function of the T antigens have also begun.