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In 60 rhesus monkeys with experimental renovascular malignant arterial hypertension (25 one-kidney and 35 two-kidney model animals), we studied the so-called 'hard exudates' or white retinal deposits in detail (by ophthalmoscopy, and stereoscopic color fundus photography and fluorescein fundus angiography, on long-term follow-up). Some manifestation of hypertensive retinopathy developed in 19 one-kidney and 19 two-kidney animals, and white deposits formed in 14 and 5 monkeys, respectively. The onset of white deposits showed no correlation to severity of arterial hypertension or of retinopathy. All eyes with white deposits had antecedent macular or retinal edema. The deposits were everchanging, taking months or even more than a year to resolve. Our study suggests that in hypertensive retinopathy the white retinal deposits are most probably the result of exudative and/or neural degenerative processes. All the available pieces of evidence indicate that it is more appropriate to call the white deposits 'lipid deposits' than 'hard exudates'.

Experimental renovascular malignant arterial hypertension was produced by modified Goldblatt's procedures, in 60 rhesus monkeys, and various retinal arteriolar changes in hypertensive retinopathy were studied in detail (by serial ophthalmoscopy, and stereoscopic color fundus photography and fluorescein fundus angiography on long-term follow-up). The retinal arteriolar changes, in ophthalmoscopically visible arterioles, consisted of arteriolar sclerosis and associated changes, e.g., increased arteriolar tortuosity, arteriolar narrowing and in some animals occlusion and sheathing of the fine arterioles; we could find no evidence of localized or generalized 'spasm' in these retinal arterioles. Eyes in animals with accelerated arterial hypertension revealed focal dilatation and leakage of the retinal precapillary terminal arterioles (resulting in development of focal intraretinal periarteriolar transudates), and also occlusion of the terminal retinal arterioles (producing cotton-wool spots and associated intraretinal microvascular abnormalities). We discuss the controversial subjects of narrowing (particularly 'spasm') of ophthalmoscopically visible retinal arterioles and of fibrinoid necrosis in malignant hypertension.

Peripheral human blood lymphocytes from healthy blood donors were investigated in vitro to observe the influence of different doses of thymopentin on nonstimulated proliferation, candidin-stimulated proliferation, and phytohemagglutinin (PHA)-induced interleukin 2 (IL2) production. Concentrations of thymopentin ranging from 0.01 to 10,000 ng/ml were used. The proliferation response in non-stimulated cultures was significantly higher in the presence of 0.01, 1, 10, 1,000, and 10,000 ng/ml of thymopentin. There was no significant increase with 0.1 or 100 ng/ml of thymopentin. Thus, three separate peaks were present in these unstimulated cultures: at a concentration of 0.01 ng/ml; between 1 and 10 ng/ml, and between 1,000 and 10,000 ng/ml. These peaks possibly represent three different subpopulations with different sensitivities to different concentrations of thymopentin. Candidin-induced proliferation was significantly higher only at concentrations of 1 and 10 ng/ml of thymopentin, corresponding to the second peak in the unstimulated culture. No other thymopentin concentrations induced significant increase in the candidin-stimulated cultures. No IL2 production was observed in the unstimulated cultures, even in the presence of thymopentin. On the contrary, preincubation with different concentrations of thymopentin influenced PHA-induced IL2 production. A significant increase in the IL2 level was observed in the supernatant of the cultures if 1,000 ng/ml of thymopentin was used in the preculture period. This concentration corresponds to the third peak in the unstimulated cultures. No significant changes were observed with other concentrations of thymopentin. As the measured value of IL2 is a result of a balance between IL2 production and utilization, the above-mentioned findings need further investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Thymopentin, a synthetic pentapeptide corresponding to the active site of thymopoietin, has been shown to restore antibody production in old mice. A decrease in immune response can also be observed in elderly humans, which is mainly caused by defective T cell function. The present study shows that the immunomodulating properties of thymopentin involve both specific and nonspecific responses in a population of elderly people vaccinated with keyhole limpet hemocyanin (KLH) antigen. Furthermore, it is demonstrated that these effects depend upon the mode of administration of thymopentin: The specific KLH antibodies (IgM and IgG), measured by solid-phase radioimmunoassay, reach the highest titers after subcutaneous injection. The lowest titers are produced after intravenous injections, whereas the responses to placebo are between these two ranges. The nonspecific immunoglobulin production, measured by nephelometry, does not follow the same pattern, suggesting that different regulatory mechanisms are involved. Future implications of these findings are discussed.

We produced experimental renovascular malignant arterial hypertension by a modified Goldblatt's procedure in 60 rhesus monkeys (25 one-kidney model and 35 two-kidney model), and studied various macular lesions by detailed serial ophthalmoscopy, and stereoscopic color fundus photography and fluorescein fundus angiography on a long-term follow-up. The various lesions which developed in the macular region included retinal edema, cystic retinal changes, serous retinal detachment, retinal pigment epithelial changes (initially acute focal and later degenerative lesions), and lipid deposits. In addition to these, the usual retinal lesions associated with hypertensive retinopathy, e.g., focal intraretinal periarteriolar transudates, cotton-wool spots and retinal hemorrhages, were also frequently seen in the macular retina. Findings on the various lesions are described in detail, and the pathogenesis of macular edema in malignant arterial hypertension is discussed.

We produced experimental renovascular malignant arterial hypertension by modified Goldblatt's procedures, in 60 rhesus monkeys. Hypertensive retinopathy was studied in detail (by ophthalmoscopy, and stereoscopic color fundus photography and fluorescein fundus angiography on long-term follow-up). Cotton-wool spots (CWSs) were found to be an important, early retinal lesion. On ophthalmoscopy, they had a characteristic appearance. Fluorescein fundus angiography of these lesions revealed focal retinal capillary nonperfusion. The CWSs usually lasted for over 3 weeks and resolved within 6 weeks, leaving permanent obliteration of the retinal capillaries in their distribution, secondary intraretinal microvascular abnormalities, and retinal nerve fiber loss. We discuss pathogenesis and other features of CWSs. There is overwhelming evidence that CWSs are due to occlusion of the terminal retinal arterioles, resulting in acute focal inner retinal ischemia; hence the scientifically valid term for them would be 'inner retinal ischemic spots'.

Monoclonal antibodies were used to determine the level of circulating helper and suppressor T cells in 34 infants and adults with severe atopic dermatitis and in normal controls. The percentage of OKT3 (total T lymphocytes) was reduced significantly in all the atopic infants. The percentage of OKT8 (suppressor-cytotoxic T lymphocytes) was reduced significantly in all patients with active lesions. The percentage of T gamma lymphocytes was reduced in all the atopic patients with or without active lesions.