Co-morbidities and mortality associated with intracranial bleeds and ischaemic stroke.

Stroke is a leading cause of mortality and acquired disability; however, there has been no comprehensive comparison of co-morbid risk factors between different stroke subtypes. The aim of this study was to compare risk factors and mortality for subdural haematoma (SDH), subarachnoid haemorrhage (SAH) and ischaemic and haemorrhagic stroke. We compiled a database of all patients admitted with these conditions to a large teaching hospital in Birmingham, United Kingdom during the period 2000-2007 using the International Classification of Disease (ICD) 10th revision codes. Generalised linear models were constructed to calculate relative risks (RRs) associated with co-morbidities. In total, 4804 patients were admitted with diagnoses of SDH (1004), SAH (807), ischaemic stroke (2579) and haemorrhagic stroke (414). Patients with SDH were less likely to have pneumonia (0.492, 95% CI, 0.330-0.734; p < 0.001), whereas alcohol abuse (4.21, 95% CI, 2.82-6.28; p < 0.001) was more common. In SAH, ischaemic heart disease (0.56, 95% CI, 0.40-0.79; p < 0.001) was less common. As expected, a range of cardiovascular risk factors were associated with ischaemic stroke. Epilepsy was positively associated with ischaemic stroke (1.94, 95% CI, 1.36-2.76; p < 0.001), indicating a role for targeted primary prevention in patients with epilepsy. Five-year survival was lower in ischaemic and haemorrhagic strokes (41% and 40% respectively, vs. 73% in SDH and 64% in SAH; p < 0.001). These findings may guide clinical risk stratification, and improve the prognostic information given to patients.

Design principles for bifunctional targeted oligonucleotide enhancers of splicing.

Controlling the patterns of splicing of specific genes is an important goal in the development of new therapies. We have shown that the splicing of a refractory exon, SMN2 exon 7, could be increased in fibroblasts derived from patients with spinal muscular atrophy by using bifunctional targeted oligonucleotide enhancers of splicing (TOES) oligonucleotides that anneal to the exon and contain a 'tail' of enhancer sequences that recruit activating proteins. We show here that there are striking agreements between the effects of oligonucleotides on splicing in vitro and on both splicing and SMN2 protein expression in patient-derived fibroblasts, indicating that the effects on splicing are the major determinant of success. Increased exon inclusion depends on the number, sequence and chemistry of the motifs that bind the activator protein SRSF1, but it is not improved by increasing the strength of annealing to the target site. The optimal oligonucleotide increases protein levels in transfected fibroblasts by a mean value of 2.6-fold (maximum 4.6-fold), and after two rounds of transfection the effect lasted for a month. Oligonucleotides targeted to the upstream exon (exon 6 in SMN) are also effective. We conclude that TOES oligonucleotides are highly effective reagents for restoring the splicing of refractory exons and can act across long introns.