Antioxidant enzyme activities and total nitrite/nitrate levels in the collar model. Effect of nicardipine.

There is a large body of literature describing the causative role of oxidative stress mediated by increased levels of reactive oxygen species in the pathogenesis of cardiovascular disease such as atherosclerosis, hypertension, and restenosis after angioplasty. The positioning of a soft silicone collar around the rabbit carotid artery elicits intimal thickening. The findings from recent studies demonstrated that both intimal thickening and atherosclerosis lead to synthesis of inducible nitric oxide synthase, resulting in abundant amounts of nitric oxide. We investigated the effects of collaring and nicardipine treatment on the activities of antioxidant enzymes, superoxide dismutase and catalase, and total nitrite/nitrate levels, stable products of nitric oxide. Placing the collar increased the total nitrite/ nitrate levels and decreased superoxide dismutase activity in collared arteries. Treatment with nicardipine (20 mg/kg/day, s.c.) prevented enhanced nitric oxide degradation without affecting superoxide dismutase and catalase activities. Our results suggest that enhanced nitric oxide production and superoxide anion are generated in response to the collaring, resulting in oxidative stress within the segment in this model.     

Growth in Turkish children in Stockholm

Height, weight and body proportions were studied in 155 Turkish school children born in Sweden, living in a defined area in Stockholm. They were compared with Swedish children matched for sex, age and physical environment, and with a smaller number of Turkish children born in Turkey or in countries other than Turkey and Sweden. Parents' socio-economic levels were extremely low on a Swedish comparison. Growth was correlated to socio-economic background. The study was cross-sectional and longitudinal, combining growth data for key ages from health documents with contemporary data. Turkish schoolchildren under 10 years of age, born in Sweden, were significantly shorter than Swedish children, the difference beginning in the pre-school years. Turkish children born in Turkey were short on arrival in Sweden but soon caught up with the Turkish children born in Sweden. Genetic factors only could not explain the difference in height-for-age between Turkish children born in Sweden and Swedish children. With a longer period of stay in Sweden an increase in height-for-age would be expected.     

Corneal allograft rejection in rabbits

We performed a phase I study to assess the therapeutic efficacy of an anti-T cell monoclonal antibody conjugated with ricin A-chain in a corneal graft rejection model. Corneal allografts were exchanged between Dutch and New Zealand rabbits. Rejections occurred within 16-22 days in untreated animals. Graft rejection was delayed by topical or retrobulbar cyclosporine, but not by subconjunctival injections of a murine anti-rabbit T cell monoclonal antibody, nor by either subconjunctival or intravenous F(ab')2-ricin conjugate.     

Biological activity of the potent uridine phosphorylase inhibitor 5-ethyl-2,2'-anhydrouridine

5-Ethyl-2,2'-anhydrouridine (ANEUR) proved to be a potent inhibitor of uridine phosphorylase isolated from sarcoma 180 cells with an apparent Ki (Ki(app) value of 99 nM. Coadministration of ANEUR with 5-fluorouridine (FUR) resulted in increased toxicity of FUR. The LD50 value of FUR alone was 9 mg/kg (when administered for 5 consecutive days) while the LD50 was 3 mg/kg when FUR was administered together with ANEUR in vivo. There was no significant difference in mean tumor weight on day 10 between control animals and animals treated with FUR (5 mg/kg/day for 3 days) or ANEUR (280 mg/kg/day for 3 days). When FUR was coadministered with ANEUR, mean tumor weight was 91% less than that of the untreated controls, showing that ANEUR, the potent URPase inhibitor, increases the antitumor effect of FUR.     

Antiinflammatory, analgesic, and antipyretic effects of an aqueous extract of Erythraea centaurium

Erythraea centaurium is a plant which is used in the treatment of various inflammatory conditions in popular medicine. The aqueous extract of the plant has been examined for its antiinflammatory, analgesic, and antipyretic effects in several animal models. The extract exhibited antiinflammatory and antipyretic activity although no analgesic activity was observed.     

Cataract extraction in uveitis: comparison of aphakia and posterior chamber lens implantation.

We reviewed the charts of 39 patients (45 eyes) with uveitis who underwent cataract extraction (intracapsular or extracapsular) with or without implantation of a posterior chamber intraocular lens (IOL) at the Royal Victoria Hospital, Montreal, between 1981 and 1990. The nine eyes with Fuchs' iridocyclitis in which an IOL was implanted had good visual results and few postoperative complications. The 18 eyes with uveitis other than Fuchs' iridocyclitis that received an IOL did not show a greater risk of postoperative complications than those left aphakic (n = 17), and the postoperative visual acuity was comparable to that of the aphakic eyes. Although the numbers are small, we conclude that the presence of uveitis does not automatically exclude posterior chamber pseudophakia.     

Disseminated lupus erythematosus in children: guidelines about investigations during the initial evaluation and follow-up]

Childhood-onset systemic lupus erythematosus (SLE) is often severe and has a serious long-term morbidity. Pediatric guidelines about its management do not exist. The French study group of childhood-onset SLE proposes recommendations about the investigation which are needed at diagnosis and during follow-up of SLE, in order to adjust the treatment according to the severity of the disease and to avoid unnecessary investigations.     

The cellular mechanism of thalamic ponto-geniculo-occipital waves

The cellular mechanisms underlying the genesis of thalamic ponto-geniculo-occipital waves were studied in reserpinized cats under urethane anaesthesia. Simultaneous field potential and intracellular recordings were performed in the lateral geniculate nucleus after acute lesions of retinal and visual cortical inputs. In most relay cells, reserpine-induced ponto-geniculo-occipital waves were associated with a transient depolarization that was often interrupted by a unitary inhibitory postsynaptic potential. The depolarization grew in size with membrane hyperpolarization and was accompanied by an increase in membrane conductance. The inhibitory postsynaptic potential is likely to have resulted from the activation of intrageniculate interneurons since perigeniculate cells were always inhibited during the occurrence of ponto-geniculo-occipital waves. Under reserpine, thalamic ponto-geniculo-occipital waves could also be triggered by peribrachial or auditory stimulation. These evoked ponto-geniculo-occipital waves were associated with intracellular events identical to those occurring spontaneously after reserpine administration. In addition, thalamic spindle oscillations were readily blocked by the occurrence of spontaneous or evoked ponto-geniculo-occipital waves. On the basis of the present results and those already published in the literature, the conclusion is reached that lateral geniculate ponto-geniculo-occipital waves result from a nicotinic activation of relay cells and from a parallel muscarinic inhibition of perigeniculate cells by peribrachial afferents. The functional significance of the ponto-geniculo-occipital activity is discussed on the basis of the antagonistic action of these signals on thalamic oscillations. It is proposed that these signals are the central correlates of orienting reactions elicited by sensory stimuli during waking (the so-called eye movement potentials) and by internally generated drives during paradoxical sleep.