Human aortic fibrolipid lesions. Progenitor lesions for fibrous plaques, exhibiting early formation of the cholesterol-rich core.

The early development of the lipid-rich core and other features of atherosclerotic fibrous plaques has been elucidated by examining discrete, small regions of raised intima in human aorta, which often bear a resemblance to both fatty streaks and fibrous plaques. Approximately one-fourth of small raised lesions (less than 16 sq mm of surface area) contained little or no stainable lipid, while three-fourths had a characteristic appearance, which included a superficial layer of foam cells, a core of noncrystalline and/or crystalline lipid, and a developed or developing collagenous cap. Total intimal volumes of the lipid-containing lesions, termed "fibrolipid lesions," ranged from 3 to 43 microliters, with the majority less than 16 microliters. Core lipid in the smallest lesions was located in the musculoelastic layer of the intima. In larger lesions the core extended luminally into the elastic hyperplastic layer, and cholesterol crystals were found more frequently. Total cholesterol concentration in fibrolipid lesions was similar to that in fatty streaks; however, the ratio of unesterified to total cholesterol was relatively high, similar to that found in fibrous plaques. It is concluded that 1) the formation of a lipid-rich core and cholesterol crystallization are early events in the development of many raised lesions; 2) the consistent association between the superficial layer of foam cells and the deep-lying lipid-rich core raises the possibility of an influence, possibly indirect, of foam-cell lipid metabolism on core formation; and 3) the fibrolipid lesion may represent one stage in a potential transitional morphologic sequence between fatty streak and fibrous plaque.     

Eccentric visual acuity in patients with macular disease

A series of cards each containing a two dimensional array of identical Snellen "E's" was used to determine best eccentric visual acuity in patients with macular disease having Snellen visual acuity of 20/70 or worse. Each "full field E" card simultaneously presents the same letter to foveal and parafoveal areas. This test can therefore determine quickly if potentially useful vision is present in any area of the central visual field. In our study of 37 eyes, 70% demonstrated potential visual acuity at least two times better than visual acuity measured by conventional methods, and 20% demonstrated at least a fourfold improvement. This suggests that most patients with macular disease do not spontaneously employ their best remaining area of retina for fixation.     

Original papers: A combination horizontal/vertical prism bar A precisely calibrated tool for use in front of one eye

The authors used an optical bench to investigate calibration and errors from improper positioning of prism bars manufactured by R.O. Gulden and Luneau. They urged Gulden to redesign its prism bars to be used back-to-back in front of one eye. The horizontal bar is held with its flat face posteriorly within a channel on the flat face of the vertical bar; the interface is positioned perpendicular to the direction of the fixation object, which demands that the horizontal prism bar be calibrated in the frontal plane position and the vertical bar in the Prentice position. Analysis of calibration demonstrated that Gulden's new combination horizontal/vertical prism bar can be used without significant error (within + 0.5δ of labelled values). Gulden's old vertical prism bar is also calibrated in the Prentice position. Luneau's horizontal and vertical prism bars are calibrated close to the frontal plane position (within +1.0δ and +0.4δ respectively). Improper positioning demonstrated an increasing error with larger prisms. Luneau's 25δ segment measured 27.8δ in the Prentice position, the 40δ segment 67.5δ. The 25δ segment of Gulden's new and old vertical prism bars measured 23.25δ in the frontal plane position. Gulden's vertical prism bars should always be held with the flat surface toward the examiner. Luneau's horizontal and vertical prism bars should be held one in front of each eye when used simultaneously; thus, neither eye is looking directly at the fixation object and defining primary and secondary deviations is not possible. The combination horizontal/vertical prism bar is manufactured by Gulden Ophthalmics, 225 Cadwalader Avenue, Elkins Park, PA 19117-2097. The Luneau prism bars are manufactured by Luneau Ophtalmologie, B.P. 252, 28005 Chartres Cedex, France. The authors have no proprietary or financial interest in these products or in the companies involved.     

The Lancaster red-green test before and after occlusion in the evaluation of incomitant strabismus.

BACKGROUND: Patients with incomitant strabismus can often fuse in a limited area of gaze. Prolongation of neurologically learned fusional vergence tone ("vergence adaptation") in and near this area can result in misleading measurements with standard clinical measures of strabismus. Monocular occlusion for at least 30 minutes eliminates most of the effect of vergence adaptation. The Lancaster red-green test provides an elegant and convenient map of incomitant strabismus. We investigated the efficacy of the Lancaster red-green test before and after monocular occlusion for the investigation of incomitant strabismus. METHODS: We retrospectively studied the results of the Lancaster red-green test in 6 patients with incomitant vertical strabismus in whom we suspected that vergence adaptation might be distorting the pattern of deviation. The test was performed before and after monocular occlusion for 30 to 60 minutes, and the preocclusion and postocclusion results were compared. RESULTS: In the 6 cases studied, the Lancaster red-green test showed at least a 5-PD increase in the hyperdeviation, after monocular occlusion. The increases were mostly in primary gaze and downgaze, which tended to regularize the pattern of deviation. CONCLUSIONS: The combination of monocular occlusion and the Lancaster red-green test is useful for uncovering the effect of vergence adaptation. Such results may often simplify the planning of surgical correction because the incomitance usually decreases after monocular occlusion, making it less likely that surgery will worsen the alignment in the area previously fused. We recommend that monocular occlusion should be considered when planning surgery or even prism correction for incomitant deviations, especially when the initial Lancaster red-green test shows an unexpected incomitant pattern where there is fusion in 1 direction of gaze but not in others.     

Dynamic progression of contractile and endothelial dysfunction and infarct extension in the late phase of reperfusion

BACKGROUND: Myocardial injury during early reperfusion (R) has been well documented. However, the extent and time course of myocardial injury during late R are still unclear. The purpose of this study was to determine the extent of regional contractile and endothelial dysfunction and myocardial blood flow (MBF) defect as well as extension of infarction in association with neutrophil (PMN) actions during R. MATERIALS AND METHODS: A total of 29 dogs underwent a protocol of 1 h LAD ischemia followed by 6, 24, 48, and 72 h of R, respectively. Regional contractile function (sonomicrometry), MBF (colored microspheres), infarct size (triphenyltetrazolium chloride staining), and PMN localization (immunohistochemistry) were determined. RESULTS: Percentage segmental shortening at 6, 24, 48, and 72 h of R was significantly blunted (-1.8 +/- 1.2,* - 0.37 +/- 0. 6,* 0.04 +/- 0.2,* and 5.9 +/- 1.2* vs baseline 17.7 +/- 0.8). MBF (ml/min/g) was attenuated at 24 (0.27 +/- 0.03*), 48 (0.46 +/- 0. 07*), and 72 h of R (0.48 +/- 0.06*) vs 6 h of R (0.65 +/- 0.06). Infarct size increased from 6 (27 +/- 2%) to 24 h of R (41 +/- 2%*) with no further increase at 48 and 72 h of R, consistent with a peak of creatine kinase activity. PMN adherence (mm(2) endothelium) to left anterior descending coronary artery (LAD) segments was increased after 6 h of R (63 +/- 3*) vs nonischemic left circumflex coronary artery (LCX) segments (42 +/- 2) with a peak at 48 h of R (111 +/- 5*). Endothelium-dependent vascular relaxation in the LAD was also blunted at 6, 24, and 48 h of R. Immunostaining revealed CD18-positive PMNs were mainly accumulated in intravascular space during 6 h of R with an increase in migration of PMNs seen at 24 h of R, consistent with a peak of myeloperoxidase release. Myeloperoxidase activity in a given area at risk sample was significantly correlated with infarct extension during the first 24 h of R. CONCLUSIONS: These results provide pathologic evidence for myocardial injury during the extended R and a basis for exploration of interventions designed to limit myocardial injury after ischemia. (*P < 0.05 vs Baseline, 6 h of R and LCX segments.) Copyright 2000 Academic Press.     

Cryoneurolysis before Total Knee Arthroplasty in Patients With Severe Osteoarthritis for Reduction of Postoperative Pain and Opioid Use in a Single-Center Randomized Controlled Trial

BackgroundWe hypothesized that preoperative cryoneurolysis of the superficial genicular nerves in patients with osteoarthritis would decrease postoperative opioid use relative to standard of care (SOC) treatment in patients undergoing total knee arthroplasty (TKA).MethodsPatients received either cryoneurolysis (intent-to-treat [ITT]: n = 62) or SOC (ITT: n = 62). The cryoneurolysis group received cryoneurolysis of the superficial genicular nerves 3–7 days before surgery plus a similar preoperative, intraoperative, and postoperative pain management protocol as the SOC group. The primary end point was cumulative opioid consumption in total daily morphine equivalents from discharge to the 6-week study follow-up assessment. Secondary end points included changes in pain and functional scores. Primary and secondary end points were assessed using ITT and per-protocol (PP) analyses.ResultsThe primary end point was not met in the ITT analysis (4.8 [cryoneurolysis] vs 6.1 [SOC] mg; P = .0841) but was met in the PP analysis (4.2 vs 5.9 mg; P = .0186) after excluding patients with medication deviations or missing follow-up data. Compared with the SOC group, the cryoneurolysis group had improved functional scores and numerical improvements in pain scores across all follow-up assessments, with significant improvements observed in current pain from baseline to the 72-hour and 2-week follow-up assessments and pain in the past week from baseline to the 12-week follow-up assessment.ConclusionFindings from the PP analysis suggest that preoperative cryoneurolysis in patients with knee osteoarthritis can reduce opioid consumption and improve functional outcomes after TKA.