Opposite effects of lateral septal LTP and lateral septal lesions on contextual fear conditioning in mice.

The effect of fimbrial high-frequency stimulation (HFS)-induced long-term potentiation (LTP) in the lateral septum (LS) on contextual fear conditioning was studied in mice. Mice were conditioned for fear toward a novel context through the use of footshocks. The 1st experiment showed that pretraining HFS reduced significantly conditional freezing to contextual stimuli. The 2nd experiment was designed to determine whether the reduction of freezing produced by fimbrial HFS resulted from LTP in the LS rather than from LTP in other brain structures. Accordingly, mice with lesions of the LS were used and submitted to the same protocol as in the 1st experiment. Results showed that LS lesions completely abolished the impairing effect of fimbrial HFS and, as a whole, potentiated the freezing response. These data suggest that contextual fear conditioning is strongly modulated by the level of hippocampal–LS synaptic neurotransmission. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metacognitive awareness and prevention of relapse in depression: Empirical evidence.

Metacognitive awareness is a cognitive set in which negative thoughts/feelings are experienced as mental events, rather than as the self. The authors hypothesized that (1) reduced metacognitive awareness would be associated with vulnerability to depression and (2) cognitive therapy (CT) and mindfulness-based CT (MBCT) would reduce depressive relapse by increasing metacognitive awareness. They found (1) accessibility of metacognitive sets to depressive cues was less in a vulnerable group (residually depressed patients) than in nondepressed controls; (2) accessibility of metacognitive sets predicted relapse in residually depressed patients; (3) where CT reduced relapse in residually depressed patients, it increased accessibility of metacognitive sets; and (4) where MBCT reduced relapse in recovered depressed patients, it increased accessibility of metacognitive sets. CT and MBCT may reduce relapse by changing relationships to negative thoughts rather than by changing belief in thought content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of dietary protein on the fatty acid composition and Δ6 desaturase activity of rat hepatic microsomes

Recently, significant differences between rats fed a casein diet and rats fed a soybean protein diet have been observed in hepatic phospholipid fatty acid patterns (Sjöblom, L., and Eklund, A.,Biochim. Biophys. Acta 1004, 187–192, 1990). The influence of these two diets on the Δ6 desaturase activity was investigated in the present study because the hepatic desaturase system is a source of unsaturated fatty acids. The rats fed a casein diet showed higher desaturase activity than those fed soybean protein when using either linoleic acid (P<0.005) or oleic acid (P<0.05) as substrates. The phosphatidylcholine fraction of hepatic microsomes showed increases in oleic acid (P<0.005) and 20∶3ω9 (P<0.001) levels as well as decreases in stearic acid (P<0.001), linoleic acid (P<0.005) and arachidonic acid (P<0.005) levels in rats which were fed casein rather than soybean protein. Similar differences between the two groups were also observed in the phosphatidylethanolamine and phosphatidylinositol fractions. These data indicate that the qualitative properties of the dietary protein source may influence the fatty acid pattern of rat hepatic microsomes by interfering with Δ6 desaturase activity.     

Effects of double-bond configuration on interaction between a moth sex pheromone component and its receptor

The dependence of the electrophysiological activity on the change of double-bond configuration of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, and a dienic analog, (E)-2,(Z)-5-decadienyl acetate, have been investigated by single-cell measurements and molecular mechanics calculations (MM2). A previously reported model for the interaction between a moth sex pheromone component and its receptor has been refined. This new model gives an essentially quantitative correlation between the measured activities and the calculated conformational energies for a biologically active conformation defined by the model. Previously obtained structure-activity results for chain-elongated analogs of (Z)-5-decenyl acetate are significantly improved by the refined model. The effect of a change of the double-bond configuration on the substrate-receptor interaction is not additive but depends on the conformational properties of the entire molecule.     

Psychophysiological reactivity to mental arithmetic stress in Black and White normotensive men.

34 Black and 42 White male normotensives 34–55 yrs old performed a mental arithmetic task while blood pressure, heart rate, and skin conductance were recorded. Compared with Whites, Blacks had significantly higher baseline diastolic blood pressure and lower skin conductance levels. These effects persisted during performance of the mental arithmetic task. When baseline differences were covaried, there were no significant physiological effects associated with the task. There were no significant race or family history effects, and task performance did not influence the outcome. Failure to demonstrate greater cardiovascular reactivity in Blacks and all men with a positive family history of hypertension is discussed with regard to possible survivor effects and methodologic limitations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of CHn group abundances in fossil fuel materials using DEPT 13C n.m.r.

¹³C n.m.r. subspectra assigned to CH, CH₂ and CH₃ groups can be obtained in reasonably quantitative conditions by using the distortionless enhancement by polarization transfer (DEPT). The method has been applied to light and heavy petroleum materials.     

Effects of sex and lesion locus on measures of intelligence.

Previous reports of the cognitive effects of lateralized brain damage in men and women have been conflicting, some suggesting significant differences in the pattern of intellectual deficits and others failing to do so. This article reports Wechsler Adult Intelligence Scale (WAIS) IQ data from 64 patients with cortical neoplasms confined to one of four brain quadrants. Analyses indicated a significant main effect for lesion laterality for verbal IQ scores (but not for performance IQ scores) as well as for verbal IQ–performance IQ difference scores. There were no significant main effects for sex or lesion site (in the anterior–posterior dimension) and no significant interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autoimmune thrombopenic purpura. Clinical practices during diagnosis. A French survey and recommendations. French College of Hemotologists Evaluation Commission

THE SURVEY: To better ascertain diagnostic and treatment strategies used by physicians for idiopathic thrombocytopenic purpura, a questionnaire was addressed to 298 French hematologists and pediatricians. One hundred and ten responses were analyzed. DIAGNOSTIC APPROACH: Thrombocytopenia was determined on capillary blood samples by 50% of the physicians and platelet-associated antibody by 44%. Bone marrow aspirates were obtained more frequently in adults (85%) than in children (47%) and immune disorders were more often investigated in 95% of adults and in 68% of children. THERAPEUTICS: Treatment threshold was lower in children (20.10(9)/l) than in adults (50.10(9)/l). Corticoidsteroids was the treatment of choice in adults (98%) and children received either IV immunoglobulins (61%) and/or corticosteroids (63%); higher doses were used in children (> or = 2 mg/kg versus 1 mg/kg) for shorter periods (> or = 2 weeks versus > 3 weeks). Treatment failure was evaluated earlier in children (< 10 days) than in adults (> 20 days). RECOMMENDATIONS: 1. Diagnosis. Based on repeatedly low platelet counts and verification that only platelets are involved. Clinical examination is normal excepting rare cases of severe hemorrhage. Search for antiplatelet antibodies is non-contributive 2. Treatment Short-term corticosteroids, both in children and adults. Intravenous gammaglobulins should be limited to cases with signs of severe hemorrhage. 3. Consult the complete guidelines for each individual clinical situation.