Mitochondrial DNA haplogroups and risk of transient ischaemic attack and ischaemic stroke: a genetic association study.

Background: Genetic factors have a role in the pathogenesis of ischaemic stroke, but the main genes involved have yet to be defined. Mitochondrial mechanisms have been implicated in the pathophysiology of acute stroke, but the role of mitochondrial DNA (mtDNA) has not been comprehensively studied. We investigated whether there is an association between mtDNA haplotypes and incidence of stroke.

Lack of association between aspirin responsiveness and seven candidate gene haplotypes in patients with symptomatic vascular disease.

We studied the effect of prophylactic aspirin (ASA) ingestion on platelet function in 463 patients with stroke, transient ischemic attack (TIA) or acute coronary disease (ACD), using the Platelet Function Analyzer-100 (PFA-100). We correlated ASA responsiveness with haplotypes of seven candidate genes, selected for their documented role in platelet function, namely, the genes for integrins alpha2beta1and alphaIIbbeta3 (ITGA2, ITGA2B, and ITGB3), platelet glycoproteins Ibalpha and VI (GPIBA and GP6), the purinergic receptor P2Y1 (P2RY1), and prostaglandin H synthase 1 (PTGS1 = COX1). Non-responsiveness to ASA was defined as the failure of prior ASA ingestion to prolong the PFA-100 closure time (CT) when blood was perfused through cartridges coated with collagen plus epinephrine (CEPI-CT).

Density and cross-sectional areas of axons in the olfactory tract in control subjects and Alzheimer's disease: an image analysis study.

Objective: Using an image analysis system to determine whether there is loss of axons in the olfactory tract (OT) in Alzheimer's disease (AD).

Design: A retrospective neuropathological study.

Patients: Nine control patients and eight clinically and pathologically verified AD cases.

Lack of reproducibility of assessment of aspirin responsiveness by optical aggregometry and two platelet function tests.

The term aspirin-resistance describes the failure of aspirin to inhibit thromboxane A(2) production. Many new tests have become available for potentially measuring aspirin responses but some are non-specific and do not isolate COX-1 activity. We previously demonstrated that agreement between two tests (PFA-100 and VerifyNow-ASA) and light transmission aggregation (LTA) was no greater than would be expected by chance.

A quantitative analysis of optic nerve axons in elderly control subjects and patients with Alzheimer's disease.

Objective: To study the density and cross-sectional area of axons in the optic nerve in elderly control subjects and in cases of Alzheimer's disease (AD) using an image analysis system.

Methods: Sections of optic nerves from control and AD patients were stained with toluidine blue to reveal axon profiles.

Results: The density of axons was reduced in both the center and peripheral portions of the optic nerve in AD compared with control patients.