Combined effect of hypokinesia of various duration and gamma-radiation on central nervous system activity in rats]

There studied the effects of a combined effect of hypokinesia (HK) of various duration (7 and 30 days, corresponding to the stages of anxiety and resistance of general adaptation syndrome) and gamma-radiation dose of 3 Gy on the formation of differentiated motor-drinking conditioned reflex (CR) in the rats. It is demonstrated that the applied exposures lead to the various disorders of the higher nervous activity of the test animals: after 7-day hypokinesia in the behaviour there prevail the fear and emotional-vegetative components whereas following 30-day hypokinetic exposure there occurs some stimulation of the orientation-exploratory behaviour with concurrent enhancement of the inertness of nervous processes and the tendency to formation of stringent behavioural stereotypes slowing-down the conditioned reflex formation. A modifying effect of radiation counts only after 30-day hypokinesia and consists in the development of extra-limited inhibition (reaction of acquired helplessness) in the part of animals.     

Adriamycin-induced oxidative stress in rat central nervous system

Adriamycin elicited a stimulation of rat central nervous system lipid peroxidation, both in vivo and in vitro, as evidenced by the increase in the content of thiobarbituric acid reactants, which was found to be NADPH-dependent. The antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase were seen to decrease on exposure to adriamycin (1 mg/kg for a period of 7 days), together with a significant decrement in the GSH/GSSG ratio, thus contributing to the oxidative insult to the tissue. The in vitro addition of GSH or vitamin E to brain homogenates offered protection against adriamycin-induced lipid peroxidation, suggesting that supplementation with these antioxidants could improve the therapeutic value of the drug.     

Schizophrenia and central nervous system pathology.

The Rorschach protocols of 3 groups of patients, typical process schizophrenics, atypical or reactive schizophrenics, and schizophrenics with known central nervous system pathology were examined for incidence of Piotrowski's 10 signs of organic involvement. It was found that organic and process groups could not be distinguished from each other, but both of these groups showed significantly more subjects with at least five signs than did the reactive group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social isolation increases cholecystokinin mRNA in the central nervous system of rats

To investigate cholecystokinin (CCK) mRNA changes induced by social isolation rats were isolated in single cages soon after weaning for 30 days. They were then sacrificed and their brains removed for in situ hybridization (ISH) study. Control animals were housed in groups of 6 per cage for the same period. ISH was performed using a 32P-labelled oligonucleotide probe complementary to CCK-8 mRNA and the results analysed by computerized densitometry. They showed a significant increase (from 59.5-152.3%) in CCK mRNA expression in the basolateral amygdala, cortex, CA1, dorsal raphe nucleus, geniculate body and ventral tegmental area of isolated rats. These results suggest that social isolation may influence CCK gene expression.     

Influence of chronic Toxoplasma infection on ethylnitrosourea-induced central nervous system tumors in rats

Because prior work with mice had revealed remarkable inhibition of central nervous system (CNS) tumor by chronic Toxoplasma infection, the effect of immunomodulation produced by this obligate intracellular parasite was studied in rats which developed CNS tumors following transplacental exposure to the chemical carcinogen ethylnitrosourea. Groups of Fischer 344 rats which had been exposed to ethylnitrosourea were either uninfected or infected at 1 month of age with a virulent strain of Toxoplasma gondii. Rats were sacrificed when morbid symptoms from tumor growth developed, and neural tissue was prepared for light microscopy. Chronic Toxoplasma infection had no effect on the survival of rats or on the amount, location, or histological type of CNS tumor which developed. Although serum antibody to Toxoplasma was present in all infected rats for the duration of the experiment, there was no histological evidence in the brain of a cellular response to infection or to the presence of tumor. When these results are compared to prior experiments of CNS tumor in mice, they suggest that mechanisms of protection against Toxoplasma infection differ in mice and rats and that an inflammatory component produced by the Toxoplasma organism in the brain is a necessary prerequisite for tumor inhibition.     

The central nervous system and the reinforcement of behavior.

Discusses findings on reward and drive processes, noting that an anatomical study of brain rewards revealed a relatively unified system. Experiments which help clarify the relations between brain-stimulated negative reinforcement or pain behavior are cited. It is hypothesized that 4 learning grids might project from the hypothalamus into places like the cerebellum, tectum, hippocampus, and neocortex. In these grids, rewarding messages would (1) directly augment the frequency of ongoing responses, (2) reinforce certain ongoing synaptic relations, or (3) be recorded in memory elements to serve in relation to remembered behavior patterns. These processes might occur redundantly or simultaneously. (47 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Uveitis and central nervous system vasculitis

The purpose of this double-blind study was to investigate the influence of adding a quercetin-containing supplement to the diet on plasma quercetin status, serum/platelet fatty acid levels and risk factors for heart disease. Healthy men and women with cholesterol levels of 4.0-7.2 mmol/L, consumed four capsules daily of either a quercetin-containing supplement (1.0 g quercetin/d) or rice flour placebo for 28 d. Quercetin intakes were approximately 50-fold greater than the dietary intakes associated with lower coronary heart disease mortality on the basis of epidemiologic studies. Subjects consuming quercetin-containing capsules had plasma quercetin concentrations approximately 23-fold higher than those of subjects consuming the control capsules. Quercetin supplementation did not modify serum total, LDL or HDL cholesterol or triglyceride levels. There were also no alterations of other cardiovascular disease or thrombogenic risk factors, including platelet aggregation, platelet thromboxane B2 production, blood pressure or resting heart rate. Furthermore, there was no effect on the levels of (n-6) or (n-3) polyunsaturated fatty acids in serum or platelet phospholipids. In conclusion, supplementation with quercetin-containing capsules markedly enhanced the plasma quercetin concentration but had no effect on other cardiovascular or thrombogenic risk factors.     

Aging and the central nervous system

This review of the literature on aging and the central nervous system attempts to cover the basic perameters investigated at both human and infrahuman levels for the better part of the last century. The results have indicated that there is a rather considerable lack of consistency in the data both within the frame of reference of a single species, and with regard to intraspecies comparisons. We have suggested that possible reasons for the contradictory findings would rest upon variability in techniques employed but, perhaps more importantly, on the failure of investigators in this area to standardize terminology. It is suggested that such a standardization might well be one of the more useful things to be accomplished in order to facilitate the interpretation of future work. The literature review first dealt with gross, i.e., macroscopic changes in brain morphology that could correlate with age, and then covered changes at the microscopic level. Finally, a brief review of the literature with regard to the biochemistry of aging was carried out. Implications of the data were noted where appropriate.     

Autoantibodies in central nervous system lupus

Central nervous system (CNS) involvement in patients with lupus remains both a diagnostic and a therapeutic challenge. The role of autoantibodies in the pathogenesis of CNS lupus and/or as markers for disease activity is reviewed. Doubt is cast on the value of measuring anti-neuronal antibodies. Those antibodies binding ribosomal-P protein antigens or certain phospholipids appear to have greater utility, although even in these cases there is no uniform agreement as to their precise role in CNS disease induction, or how well antibody levels reflect disease activity.     

Cyclooxygenases and the central nervous system

Prostaglandins (PGs) were first described in the brain by Samuelsson over 30 years ago (Samuelsson, 1964). Since then a large number of studies have shown that PGs are formed in regions of the brain and spinal cord in response to a variety of stimuli. The recent identification of two forms of cyclooxygenase (COX; Kujubu et al., 1991; Xie et al., 1991; Smith and DeWitt, 1996), both of which are expressed in the brain, along with superior tools for mapping COX distribution, has spurred a resurgence of interest in the role of PGs in the central nervous system (CNS). In this review we will describe new data in this area, focusing on the distribution and potential role of the COX isoforms in brain function and disease.     

Remyelination of the central nervous system

The three typical stages in the clinical course of multiple sclerosis (relapse, persistent disability and progression) can be explained on the basis of inflammation, demyelination and failure of repair leading to axon degeneration and astrocytosis. Strategies are being evaluated for limiting the inflammatory process using immunological treatments and these may have unexpected dividends in promoting endogenous remyelination. Increasing knowledge on glial lineages and axon-glial interactions needed for stable myelination also offer the prospect for enhancing remyelination through growth factor therapy and cell implantation.     

Tumors of the central nervous system

Neoplasia of the central nervous system (CNS) can be divided into two main categories: nonpituitary CNS neoplasia and pituitary adenomas. Nonpituitary CNS neoplasias are generally compressive in nature, although some are also invasive. The majority of reported CNS tumors are secondary with only a few originating from nervous tissue. Pituitary adenomas predominantly occur in the pars intermedia of the older horse. Clinical signs, diagnostic testing, and possible treatments are discussed.     

Primary central nervous system lymphoma. A changeable tumor

We have previously shown that lymphocyte beta 2-adrenoceptors (AR) are under cyclical control of sex-steroid hormones with greater receptor density during the luteal phase of the menstrual cycle. It has also been postulated that abnormal cyclical regulation of beta 2-AR might be a possible mechanism for premenstrual asthma. The effects of exogenous female sex-steroid hormones on lymphocyte beta 2-AR function were studied in eight normal healthy females. They were evaluated at two successive menstrual cycles, during the follicular phase (day 1-6). They were randomized to receive single oral doses of either ethinyloestradiol 50 micrograms or medroxyprogesterone 10 mg in a cross-over study. Lymphocyte beta 2-AR parameters were evaluated at baseline (t0), 24 h (t24) and 72 h (t72) after ingestion. Baseline levels of progesterone and oestradiol were comparable on both cycles. Receptor density (Bmax) increased significantly (P < 0.01) from t0 after progesterone but not oestradiol at t 4: a 1.39-fold geometric mean difference (95% CI 0.96-2.00) between t24 vs t0. Receptor affinity (kd) and maximal cAMP response to isoprenaline (Emax) were not altered by either treatment. These results show that exogenous progesterone but not oestradiol, given during the follicular phase, significantly increased beta 2-AR. This, therefore, suggests that endogenous progesterone is probably responsible for previously observed increase in Bmax during the luteal phase of the female menstrual cycle. These findings may suggest possible therapeutic strategies for modulation of beta 2-AR in premenstrual asthma.     

ATV-related central nervous system injuries in Louisiana

All terrain vehicles (ATVs) have been associated with death and serious injury since their introduction into the marketplace. Fifteen cases of ATV-related brain and spinal cord injury reported to the Louisiana Central Nervous System Registry during 1995 were evaluated for severity, etiology, and outcome. Eleven (73%) of these injuries were sustained by persons under 18 years of age. Despite US Consumer Product Safety Commission and ATV manufacturer recommendations for age restrictions, ATVs continue to be popular recreational devices for children.     

Glutamate receptors in the central nervous system

A lot of clinical processes following excessive stimulation of glutamate receptors seem to participate in pathophysiology of numerous acute and chronic neurological disorders. The whole of these reactions has been named as "glutamate cascade", because of the central role of glutamate in initiation and intensification of these processes. In this article, classification of different types of glutamate receptors and several hypotheses concerning mechanisms of glutamate neurotoxic activity are presented. A wide variety of neurological diseases, which etiologies are more or less connected with glutamate toxicity are discussed. At last, the future perspectives for treatment by drugs which action is thought to be mediated through glutamate receptors are presented.