The two-dimensional distribution of population activity in the superior colliculus (SC) during saccadic eye movements in the monkey was estimated using radial basis functions. To make these ensemble activity estimates, cells in the deeper layers of the SC were recorded over much of the rostrocaudal (caudal to 3.8 mm from the rostral tip), mediolateral extent of this structure. The dynamic movement field of each cell was determined at 2-ms intervals around the time of saccades for a wide variety of horizontal and oblique movements. Collicular neurons were divided into partially overlapping dorsal and ventral cell layers on the basis of recorded depth in SC. The pattern of presaccadic activity was used as an additional discriminant to sort the cells in the two layers into separate burst (dorsal) and buildup (ventral) cell classes. Rostrocaudal and medioventral cell location on the colliculus was estimated from the optimal target vector for a cell's visual response rather than from the optimal motor vector. The former technique was more reliable for locating some buildup neurons because it produced locations that compared better with the locations suggested by electrical stimulation. From the movement field data and from the estimates of each cell's anatomic location, a similar algorithm was used to compute the two-dimensional population activity in the two layers of the SC during horizontal and oblique saccades. A subset of the sample of neurons, located near the horizontal meridian of the SC, first was used to compute one-dimensional dynamic population activity estimates for horizontal saccades to allow partial comparison to previous studies. Statistical analyses on the one-dimensional data were limited to saccades of

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Certain functions of the blood neutrophils and lymphocytes from normal adult volunteers were evaluated after the ingestion of increasing doses of ascorbate. Serum immunoglobulins and levels of C'3 and total hemolytic complement were also measured. Enhancement of neutrophil motility to a chemotactic stimulus of endotoxin-activated autologous serum was observed in normal adult volunteers after the ingestion of 2 and 3 g ascorbate daily. No alteration was observed at lower doses. Other neutrophil functions evaluated that remained unaltered by ascorbate, were postphagocytic hexose monophosphate shunt activity and myeloperoxidase mediated iodination of ingested protein. Stimulation of lymphocyte transformation to the mitogens phytohaemagglutinin and concanavalin A was detected after the daily ingestion of 1, 2, and 3 g of ascorbate. Mitogen-induced protein synthesis was unaffected. Serum levels of IgG, IgA, IgM, C'3, and C'4 and total complement activity were unaltered by ascorbate.

The accuracy of coronal and sagittal magnetic resonance (MR) imaging was examined in the assessment of rotational and sideways displacements of the temporomandibular joint (TMJ) disk. Rotational disk displacement implies a combination of anterior and medial or lateral displacements, whereas sideways displacement implies pure medial or lateral displacement without an anterior component. Multiple 3-mm-thick coronal and sagittal MR images were obtained of 18 fresh TMJ autopsy specimens and compared with the observations in corresponding coronal cryosections. MR imaging correctly delineated the mediolateral position of the disk in 15 joints (83%) and incorrectly delineated it in three joints (17%). Osseous anatomy was correctly assessed in 17 joints (94%). On cryosections, six joints (33%) showed medial disk displacement and two joints (11%) showed lateral displacement. In five of these eight joints the medial or lateral displacement occurred in conjunction with an anterior displacement, that is, rotational displacement. Clinical MR imaging in 37 patients (61 joints with coronal images) showed medial or lateral disk displacement in 16 joints (26%). This study suggests that rotational and sideways displacements of the TMJ disk are an important aspect of internal derangement. The multiplanar capabilities of MR are suitable for an assessment of these abnormalities.

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Abstract-Dietary polyunsaturated fats and vitamin E are associated with reduced risk for atherosclerosis, but in smokers, they could promote lipid oxidation. Therefore, we examined the effects of a high polyunsaturated fat diet and vitamin E supplementation on measures of lipid oxidation in cigarette smokers. Ten subjects who smoked Ͼ1 pack of cigarettes per day were sequentially fed the following: a baseline diet in which the major fat source was olive oil, a diet in which the major fat source was high-linoleic safflower oil, and finally, the safflower oil diet plus 800 IU vitamin E per day. LDL oxidation lag time and rate and plasma total F 2 -isoprostanes and prostaglandin F 2␣ (PGF 2␣ ) were determined after 3 weeks on each diet. is the leading cause of morbidity and mortality in the developed world. Peroxidation of plasma LDLs by oxygen-derived free radicals has been ascribed a central role in the etiology of ASCVD. 1 The corollary to this theory is that agents that can protect LDL from peroxidation should decrease the risk of developing ASCVD, attenuate its progression, or even reverse established disease. 2 Indeed, epidemiological studies have suggested that antioxidants, such as ␣-tocopherol, confer dose-dependant protection against ASCVD, 3-5 yet prospective intervention trials 6 -8 have failed to observe a protective effect.Tobacco use is one of the most potent risk factors for ASCVD. The high concentration of free radical oxidants in tobacco smoke 9 and the fact that the impact of smoking on the incidence ASCVD correlates with plasma LDL levels 10,11 are consistent with the concept that LDL peroxidation by cigarette smoke promotes atherogenesis. 12 Indeed, measures of lipid oxidation, such as thiobarbituric acid-reactive substances (TBARS) in plasma, 13 LDL, 14 -16 and red blood cells 17 ; breath alkane excretion 18 -20 ; and F 2 -isoprostanes in urine 21 and plasma, 22 are increased in cigarette smokers. Conversely, plasma levels of antioxidant vitamins in smokers, which could protect LDL against the damaging effects of free radicals, are depressed. 23 Cigarette smokers thus constitute a high-risk population in which intervention could reduce the risk of ASCVD. Diets high in monounsaturated fatty acid (MUFA) or polyunsaturated fatty acid (PUFA) effectively lower plasma LDL, 24 but high PUFA diets constitute a theoretical risk, because PUFAs are excellent substrates for lipid peroxidation. 25 Indeed, studies in cigarette smokers 15 and in nonsmokers 26,27 have found that PUFAs increase LDL oxidation rate and also breath pentane excretion. 28 The deleterious impact of dietary PUFA on lipid oxidation, in theory, could be mitigated by concomitant supplementation with antioxidant vitamins. However, although antioxidant vitamins are generally considered to be nontoxic, 29 vitamin E is a redox reagent that can function as a pro-oxidant under certain conditions. 30 -32 This has led some to voice concerns that antioxidant vitamins could function as pro-oxidants in vivo. 33,34 The fact that prospective studi...

Abstract. The temperate sea anemone Anemonia viridis (Forsk/il) contained about 11% lipid on a dry weight basis when maintained at light levels of about 10 #E m-2 s-1 and a temperature of 10 °C. Aposymbiotic forms of the anemone had similar lipid levels. These values are very low compared with tropical symbiotic Anthozoa in which lipid levels constitute up to 50% of dry weight. In symbiotic A. viridis, < 6% of total lipid consisted of the storage lipids, wax esters and triglycerides. Most of the triglyceride was stored in the animal tissues rather than the zooxanthellae. Zooxanthellae contained only small amounts of wax esters. An analysis was made of the wax ester, triglyceride and fatty acid composition of symbiotic anemones, isolated zooxanthellae and aposymbiotic anemones. Wax ester composition was similar in symbiotic and aposymbiotic forms. However, triglyceride composition differed. In particular trimyristin (C42) was found only within the symbiotic association. Fatty acids showed a high degree of unsaturation, and acids with both even and odd numbers of carbon atoms were found. The most abundant fatty acid was 16:0 in all samples, except for the total lipids from zooxanthellae in which the major fatty acid was trans-18:l.