Predictors of early mortality after acute ischaemic stroke.

BACKGROUND The study set out to identify clinical, laboratory and radiological predictors of early mortality after an acute ischaemic stroke (AIS) and to analyse medical and neurological complications that caused death. METHODS A total of 479 consecutive patients (mean age 63+/-14 years) with AIS underwent stroke examination and treatment. Examination included clinical evaluation, laboratory tests, and brain CT and/or MRI. Follow-up data at 30 days were available for 467 patients (93%) who were included in the present analysis. RESULTS The median National Institute of Health Stroke Study (NIHSS) score on admission was 6. A total of 62 patients (13%) died within 30 days. The cause of death was the initial event in 43 (69%), pneumonia in 12 (19%), intracerebral haemorrhage in 9 (15%), recurrent stroke in 6 (10%), myocardial infarction in 2 (3%), and cancer in 1 (2%) of the patients. In univariate comparisons, advanced age (p<0.001), hypertension (p=0.013), coronary disease (p=0.001), NIHSS score (p<0.001), undetermined stroke etiology (p=0.031), relevant co-morbidities (p=0.008), hyperglycemia (p<0.001), atrial fibrillation (p<0.001), early CT signs of ischemia (p<0.001), dense artery sign (p<0.001), proximal vessel occlusion (p<0.001), and thrombolysis (p=0.008) were associated with early mortality. In multivariate analysis, advanced age (HR=1.12; 95% CI 1.05-1.19; p<0.001) and high NIHSS score on admission (HR=1.15, 95% CI 1.05-1.25; p=0.002) were independent predictors of early mortality. CONCLUSIONS We report 13% mortality at 30 days after AIS. More than two thirds of the deaths are related to the initial stroke. Advanced age and high NIHSS score are the only independent predictors of early mortality in this series.

Phylogenetic approach reveals that virus genotype largely determines HIV set-point viral load

HIV virulence, i.e. the time of progression to AIDS, varies greatly among patients. As for other rapidly evolving pathogens of humans, it is difficult to know if this variance is controlled by the genotype of the host or that of the virus because the transmission chain is usually unknown. We apply the phylogenetic comparative approach (PCA) to estimate the heritability of a trait from one infection to the next, which indicates the control of the virus genotype over this trait. The idea is to use viral RNA sequences obtained from patients infected by HIV-1 subtype B to build a phylogeny, which approximately reflects the transmission chain. Heritability is measured statistically as the propensity for patients close in the phylogeny to exhibit similar infection trait values. The approach reveals that up to half of the variance in set-point viral load, a trait associated with virulence, can be heritable. Our estimate is significant and robust to noise in the phylogeny. We also check for the consistency of our approach by showing that a trait related to drug resistance is almost entirely heritable. Finally, we show the importance of taking into account the transmission chain when estimating correlations between infection traits. The fact that HIV virulence is, at least partially, heritable from one infection to the next has clinical and epidemiological implications. The difference between earlier studies and ours comes from the quality of our dataset and from the power of the PCA, which can be applied to large datasets and accounts for within-host evolution. The PCA opens new perspectives for approaches linking clinical data and evolutionary biology because it can be extended to study other traits or other infectious diseases.

Properties of low-threshold motor axons in the human median nerve

This study investigated the excitability and accommodative properties of low-threshold human motor axons to test whether these motor axons have greater expression of the persistent Na(+) conductance, I(NaP). Computer-controlled threshold tracking was used to study 22 single motor units and the data were compared with compound motor potentials of various amplitudes recorded in the same experimental session. Detailed comparisons were made between the single units and compound potentials that were 40% or 5% of maximal amplitude, the former because this is the compound potential size used in most threshold tracking studies of axonal excitability, the latter because this is the compound potential most likely to be composed entirely of motor axons with low thresholds to electrical recruitment. Measurements were made of the strength-duration relationship, threshold electrotonus, current-voltage relationship, recovery cycle and latent addition. The findings did not support a difference in I(NaP). Instead they pointed to greater activity of the hyperpolarization-activated inwardly rectifying current (I(h)) as the basis for low threshold to electrical recruitment in human motor axons. Computer modelling confirmed this finding, with a doubling of the hyperpolarization-activated conductance proving the best single parameter adjustment to fit the experimental data. We suggest that the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel(s) expressed on human motor axons may be active at rest and contribute to resting membrane potential.

Treatment outcome of 42 replanted permanent incisors with a median follow-up of 2.8 years

To evaluate the treatment outcome of avulsed and replanted permanent incisors.

Kernel density correlation based non-rigid point set matching for statistical model-based 2D/3D reconstruction

This paper presents a kernel density correlation based nonrigid point set matching method and shows its application in statistical model based 2D/3D reconstruction of a scaled, patient-specific model from an un-calibrated x-ray radiograph. In this method, both the reference point set and the floating point set are first represented using kernel density estimates. A correlation measure between these two kernel density estimates is then optimized to find a displacement field such that the floating point set is moved to the reference point set. Regularizations based on the overall deformation energy and the motion smoothness energy are used to constraint the displacement field for a robust point set matching. Incorporating this non-rigid point set matching method into a statistical model based 2D/3D reconstruction framework, we can reconstruct a scaled, patient-specific model from noisy edge points that are extracted directly from the x-ray radiograph by an edge detector. Our experiment conducted on datasets of two patients and six cadavers demonstrates a mean reconstruction error of 1.9 mm

Assessment of letrozole and tamoxifen alone and in sequence for postmenopausal women with steroid hormone receptor-positive breast cancer: the BIG 1-98 randomised clinical trial at 8·1 years median follow-up

Postmenopausal women with hormone receptor-positive early breast cancer have persistent, long-term risk of breast-cancer recurrence and death. Therefore, trials assessing endocrine therapies for this patient population need extended follow-up. We present an update of efficacy outcomes in the Breast International Group (BIG) 1-98 study at 8·1 years median follow-up.