Increased levels of plasma cholesteryl ester hydroperoxides in patients with subarachnoid hemorrhage

The pathophysiology of subarachnoid hemorrhage (SAH) may involve free radical production and lipid peroxidation. We examined plasma levels of cholesteryl ester hydroperoxides (CEOOH) and antioxidants in 25 patients with SAH, and 10 neurologic controls with lacunar stroke. Patients with SAH had significantly increased plasma levels of CEOOH, which peaked on day 5 after the ictus. Concentrations of CEOOH were significantly increased, and ascorbic acid concentrations were significantly decreased in patients who developed vasospasm compared with patients without vasospasm. Increased levels of CEOOH were associated with increased mortality and correlated with clinical outcome scales. These results implicate oxidative stress in the pathogenesis of SAH and suggest that measurements of CEOOH in plasma may be useful both prognostically as well as in monitoring therapeutic interventions.     

GAP-43: putting constraints on neuronal plasticity

The brain must balance the need for synaptic precision with the ability to generate and change connectivity patterns in response to environmental stimuli. GAP-43 is a phosphoprotein associated with the cytosolic surface of the membrane, and is one of the most abundant among the small subset of total cellular proteins transported to the growth cone. It appears to play an unusual role amplifying signals from the microenvironment. One of the several ways to perform this task involves interaction of GAP-43 with the G protein transduction cascade. In mice rendered GAP-43 null by homologous recombination, some nerves manifest aberrant growth at decision points, such as the optic chiasm. Thus, GAP-43 may work via modulation of signaling cascades, rather than autonomously causing growth, and could serve to keep plasticity within constraints needed to generate and maintain accurate synaptic wiring.     

Manual performance and laterality in twins of known chorion type

Manual performance, direction, and degree of laterality were tested in monozygotic (MZ) twins (8-12 years old) of known chorion type and dizygotic (DZ) twins. Three manual tasks rarely employed in twin studies were used; dot-filling, tapping, and peg-moving tasks. No chorion effect was observed: the monochorionic and dichorionic MZs differed neither for frequency of discordant pairs nor for handedness, laterality measurements, and manual performance. The pooled MZs and DZs were then compared in a classic twin design. The within-pair resemblance was not higher in MZs than in DZs for variables measuring level of manual performance. For laterality scores intraclass correlations were close to zero in MZ and DZ twin groups.     

Discontinuation of treatment with IFN-beta leads to exacerbation of experimental autoimmune encephalomyelitis in Lewis rats. Rapid reversal of the antiproliferative activity of IFN-beta and excessive expansion of autoreactive T cells as disease promoting mechanisms

BACKGROUND: It is important for HIV/AIDS control programmes to determine population knowledge on AIDS in order to develop appropriate Information, Education and Communication (IEC) messages. The objectives of our study were to determine the seroprevalence of HIV and syphilis among pregnant women, female prostitutes and long-distance truck drivers and to evaluate knowledge, attitudes, beliefs, and practice (KABP) with respect to the HIV/AIDS epidemic in these three groups in Burkina Faso. METHODS: We performed three cross-sectional serosurveys including face-to-face interviews on KABP between October 1994 and February 1995 in three population groups. RESULTS: Overall, 1,294 pregnant women, 236 long-distance truck drivers and 426 female prostitutes were recruited. HIV seroprevalence was 8% (95% Confidence Interval (CI): 6.6-9.6) among pregnant women, 18.6% (95% CI: 13.9-24.2) among long-distance truck drivers and 58.2% (95% CI: 53.4-62.9) in female prostitutes. The prevalence of syphilis was 2.5%, 9.3% and 15%, respectively. Most pregnant women (98%), long-distance truck drivers (96%) and female prostitutes (98%) had already heard of AIDS. However, the level of knowledge of HIV transmission routes, of risk factors for HIV transmission and of available preventive measures was very low. Consequently, 41% of pregnant women, 40% of long-distance truck drivers and an alarming 61% of female prostitutes reported that they did not feel themselves at risk for HIV. In each group, high levels of knowledge on AIDS were associated with increased awareness of AIDS risk and the adoption of preventive behaviours. Level of education was associated with knowledge of AIDS and condom use. However, in the 12 months preceding the surveys, condom use was very low among pregnant women (0.1%), long-distance truck drivers (18%) and among female prostitutes (42%). CONCLUSIONS: These results indicate that HIV is widespread in Burkina Faso and that there is an urgent need to develop and evaluate HIV prevention strategies in the general population and among core groups such as female prostitutes and long-distance truck drivers. Interventions must include information campaigns, condom promotion and distribution, and sexually transmitted diseases control.     

Differential effects of serotonin (5-HT) lesions and synthesis blockade on neuropeptide-Y immunoreactivity and 5-HT1A, 5-HT1B/1D and 5-HT2A/2C receptor binding sites in the rat cerebral cortex

The present study was aimed at comparing the effects of serotonin (5-HT) synthesis blockade using chronic administration of p-chlorophenylalanine (PCPA) and 5,7-dihydroxytryptamine injections of variable volume (3 vs. 6 microl) on the density of NPY immunoreactive (Ir) neurons and binding of [3H]8-OH-DPAT, S-CM-G[125I]TNH2 and [125I]DOI to 5-HT1A, 5-HT1B/1D, and 5-HT2A/2C receptors in rat cortical regions. Three weeks after large but partial (89% depletion in 5-HT tissue concentration) lesions of 5-HT neurons no changes in neither NPY immunoreactivity nor 5-HT receptor binding were detected. The complete 5,7-DHT lesions produced increases in the number of NPY-Ir neurons in the upper regions of the cingular (134%), frontal (140%) and parietal cortex (48%) and corresponding decreases in 5-HT2A/2C binding (16-26%). No changes in 5-HT1A and 5-HT1B/1D binding were observed after lesions of this kind. After PCPA treatment, decreases in NPY-Ir neurons density (22-40%) and increases in 5-HT1A and 5-HT1B/1D receptor binding sites (20-50%) were distributed in both upper and deeper cortical regions. The lack of effect of the partial lesion suggests that spared 5-HT neurons may exert compensatory mechanisms up to a large extent. The changes in NPY immunoreactivity and 5-HT2A/2C binding detected in the upper regions of the cortex after complete 5-HT lesions probably result from local cellular rearrangements, whereas blocking 5-HT synthesis has more widespread influence on NPY neurons and on 5-HT1A and 5-HT1B/1D receptor subtypes. Moreover, decreases in DOPAC concentrations detected only after complete lesions suggest that the involvement of catecholaminergic transmission may also differentiate 5,7-DHT and PCPA treatments. Altogether, these data suggest that different receptor subtypes might be involved in 5-HT-NPY relationships.     

Plasma and erythrocyte alpha-tocopherol and plasma retinol concentrations in term infants fed formula enriched with long-chain polyunsaturated fatty acids

OBJECTIVE: To assess the effect of long-chain polyunsaturated fatty acids (LCPUFA)- and vitamin E-supplemented formula feeding on erythrocyte and plasma alpha-tocopherol (VE), and plasma retinol (VA) concentrations in neonates and to compare these values with those found in infants feeding on infant formula without LCPUFA or breast milk SETTING: University Hospital of Granada, Spain. SUBJECTS: 49 full-term infants. DESIGN AND INTERVENTION: Subjects who chose not to breast feed were fed either (i) unsupplemented infant formula (F) or (ii) infant formula supplemented with LCPUFA and vitamin E (FL). Alpha-tocopherol and retinol were measured at 7 days, 1 month and 3 months. RESULTS: Plasma and erythrocyte VE concentrations and plasma VE/total lipids ratio increased significantly in all groups at 1 month of life (P < 0.05), but did not change significantly between 1 month and 3 months in any group (P > 0.05). Erythrocyte VE and VA retinol concentrations were higher in infants fed an infant formula than in breast milk-fed infants at 1 month of life (P < 0.05). Finally, there were no significant differences in plasma or erythrocyte VE levels, plasma VA or plasma VE/total lipid ratio between any groups at 3 months of life (P > 0.05). CONCLUSION: Infants fed on LCPUFA- and vitamin E-supplemented infant formula for 3 months have similar vitamin E and A status to infants fed on breast milk or infant formula without LCPUFA supplementation.