No abstract

Purpose To better understand the nature of glaucomatous damage, especially to the macula, the inner retinal thickness maps obtained with frequency domain optical coherence tomography (fdOCT) were averaged. Methods Frequency domain optical coherence tomography macular and optic disc cube scans were obtained from 54 healthy eyes and 156 eyes with glaucomatous optic neuropathy. A manually corrected algorithm was used for layer segmentation. Patients’ eyes were grouped both by mean deviation (MD) and hemifield classification using standard categories and 24-2 (6° grid) visual fields (VFs). To obtain average difference maps, the thickness of retinal nerve fiber (RNF) and retinal ganglion cell plus inner plexiform (RGC+) layers were averaged and subtracted from the average control values. Results On the average difference maps, RGC+ and RNF layer thinning was seen in the patient groups with VFs classified as normal. The pattern of the thinning was the same, but the degree of thinning increased with decreased MD and with classification category (from normal to arcuate). This RGC+ thinning was largely within the central four points of the 24-2 (6° grid) field, after correcting for RGC displacement. Conclusion 1. VF categories represent different degrees of the same pattern of RGC+ and RNFL layer thinning. 2. RGC+ damage occurs in the central macula even in patients with VFs classified as normal. 3. The 6° grid (24-2) pattern is not optimally designed to detect macular damage. 4. A schematic model of RGC projections is proposed to explain the pattern of macular loss, including the greater vulnerability of the inferior retinal region. Translational relevance The 24-2 is not an optimal test pattern for detecting or following glaucomatous damage. Further, we suggest clinical fdOCT reports include RGC+ and RNFL probability plots combined with VF information.

Electrospray ionization mass spectrometry has previously been used to probe qualitative changes in the phospholipid cardiolipin (CL), but it has rarely been used in a quantitative manner. We assessed changes in the amount of individual molecular species of cardiac CL present in a model of congestive heart failure using 1,1 ,2,2 -tetramyristoyl cardiolipin as an internal standard. There was a linear relationship between the ratio of the negative molecular ion ([M-H] Ϫ ) current from four different CL reference standards and the [M-H] Ϫ from the internal standard, as a function of the concentration of CL molecular species. Therefore, this internal standard can be used to quantitate many naturally occurring CL molecular species over a wide range of CL concentrations. Using this method, changes to individual molecular species of CL in failing hearts from male spontaneously hypertensive heart failure rats were examined. CL isolated from cardiac mitochondria was compared with left ventricular tissue to demonstrate the feasibility of extracting and quantitating CL from either mitochondrial or tissue samples. The acyl chain composition of individual CL molecular species was identified using tandem mass spectrometry. In animals with heart failure, the major cardiac CL species (tetralinoloyl) decreased significantly, whereas other minor CL species were significantly increased. -Sparagna, G. C., C. A. Johnson, S. A. McCune, R. L. Moore, and R. C. Murphy. Quantitation of cardiolipin molecular species in spontaneously hypertensive heart failure rats using electrospray ionization mass spectrometry. is a unique mitochondrial phospholipid containing four acyl groups and is required for normal mitochondrial function (1, 2). Numerous enzymes involved in electron transport and oxidative phosphorylation have been shown to require CL for normal function (3). In addition, a decrease in CL levels has been implicated in mitochondrial membrane protein activity abnormalities during aging (4-6), ischemia (7), and, most recently, Barth syndrome, a genetic disease characterized by heart abnormalities (8). In addition to the quantitative changes in mitochondrial CL levels that have been implicated in various pathologies of the heart, there is now evidence that alterations in the acyl side chain composition of CL can contribute to aberrant mitochondrial function (9). Recently, alterations in CL have also been strongly implicated in several key events during programmed cell death (apoptosis) in the heart and other tissues (10-17), although the extent to which quantitative versus compositional changes in the CL pool influence these processes is poorly understood.CL has most often been studied using HPLC, which is able to separate CL from other phospholipids to assess changes in the amount of total CL. To date, determinations of CL acyl side chain composition have been largely qualitative, technically arduous, or limited to only a few of the many CL molecular species known to exist (18). Valianpour et al. (19) reported an important ad...

Lipids were generated during the routine storage of platelet concentrates that prime the NADPH oxidase, and they may play a role in the severe complications of transfusion therapy. Other non-lipid compounds, such as interleukin 8, that are generated in whole-blood platelets may also contribute to the observed priming activity of plasma.

No abstract