Contextual insensitivity in schizophrenic language processing: Evidence from lexical ambiguity.

The authors investigated whether contextual failures in schizophrenia are due to deficits in the detection of context or the inhibition of contextually irrelevant information. Eighteen schizophrenia patients and 24 nonpsychiatric controls were tested via a cross-modal semantic priming task. Participants heard sentences containing homonyms and made lexical decisions about visual targets related to the homonyms' dominant or subordinate meanings. When sentences moderately biased subordinate meanings (e.g., the animal enclosure meaning of pen), schizophrenia patients showed priming of dominant targets (e.g., paper) and subordinate targets (e.g., pig). In contrast, controls showed priming only of subordininate targets. When contexts strongly biased subordinate meanings, both groups showed priming only of subordinate targets. The results suggest that inhibitory deficits rather than context detection deficits underlie contextual failures in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The gene, ialA, associated with the invasion of human erythrocytes by Bartonella bacilliformis, designates a nudix hydrolase active on dinucleoside 5'-polyphosphates

ialA, one of two genes associated with the invasion of human red blood cells by Bartonella bacilliformis, the causative agent of several diseases, has been cloned and expressed in Escherichia coli. The protein, IalA, contains an amino acid array characteristic of a family of enzymes, the Nudix hydrolases, active on a variety of nucleoside diphosphate derivatives. IalA has been purified, identified, and characterized as an enzyme catalyzing the hydrolysis of members of a class of signaling nucleotides, the dinucleoside polyphosphates, with its highest activity on adenosine 5'-tetraphospho-5'-adenosine (Ap4A), but also hydrolyzing Ap5A, Ap6A, Gp4G, and Gp5G. In each case, a pyrophosphate linkage is cleaved yielding a nucleoside triphosphate and the remaining nucleotide moiety.     

Menstrual cycle modulation of tender points

OBJECTIVE: A summary about the final results of the Hungarian double-blind placebo controlled randomised trial of periconceptional folic acid containing multivitamin and trace element supplementation. RESULTS: The major finding is a significant prevention of the first occurrence of neural-tube defect, urinary tract and cardiovascular defects, in addition a decrease in the rate of limb deficiencies and congenital hypertrophic pyloric stenosis. Fertility was slightly improved and the rate of twins increased significantly after periconceptional multivitamin supplementation. The effect of multivitamin supplementation for fetal death is controversial, but in general there is no clinically significant change. Periconceptional multivitamin supplementation can reduce the occurrence of nausea and vomiting. PRACTICAL IMPLEMENTATIONS: Consumption of foods which are rich in folate may not be the best way to prevent neural-tube defects and other congenital abnormalities. Periconceptional multivitamin supplementation is part of the periconceptional care in Hungary and it is an appropriate forum for the practical delivery for this primary prevention action. However, as a large proportion of pregnancies are unplanned, the widespread use of bread fortified with folic acid, vitamin B12 and B6 may decrease a considerable part of neural-tube defects and some other congenital abnormalities, in addition to vascular diseases due to hyperhomocysteinemia.     

Evaluation of trainees' stay in general practice by the young physicians and their tutors

In 1991 a new reform for postgraduate trainees was introduced in Denmark. Since the reform all young doctors-as a compulsory part of their vocational training-have had to work for six months as general practice trainees, no matter their wishes for future specialization. The reform furthermore led to the general practice trainees being considerably younger than previously-the average length of postgraduate experience before working as a trainee declined from six to seven years to one to two years. In this light an investigation was conducted from August 1992 to July 1993. Seven hundred and fifty-eight questionnaires were sent to general practice trainees and their tutors in Denmark. Ninety-five percent of the questionnaires were returned, thus it was possible to evaluate the new compulsory training in general practice. In conclusion, the main part of the trainees had a positive assessment of the work conditions in general practice. However, a large part of the trainees indicated that their tutor doctors had set aside too short a time for supervision.     

Properties of human hemoglobins with increased polarity in the alpha- or beta-heme pocket. Carbonmonoxy derivatives

The spectroscopic, conformational, and functional properties of mutant carbonmonoxy hemoglobins in which either the beta-globin Val67(E11) or the alpha-globin Val62(E11) is replaced by threonine have been investigated. The thermal evolution of the Soret absorption band and the stretching frequency of the bound CO were used to probe the stereodynamic properties of the heme pocket. The functional properties were investigated by kinetic measurements. The spectroscopic and functional data were related to the conformational properties through molecular analysis. The effects of this nonpolar-to-polar isosteric mutation are: (i) increase of heme pocket anharmonic motions, (ii) stabilization of the A0 conformer in the IR spectrum, (iii) increased CO dissociation rates. The spectroscopic data indicate that for the carbonmonoxy derivatives, the Val --> Thr mutation has a larger conformational effect on the beta-subunits than on the alpha-subunits. This is at variance with the deoxy derivatives where the conformational modification was larger in the heme pocket of the alpha-subunit (Cupane, A., Leone, M., Militello, V., Friedman, R. K., Koley, A. P., Vasquez, G. P., Brinigar, W. S., Karavitis, M., and Fronticelli, C. (1997) J. Biol. Chem. 272, 26271-26278). These effects are attributed to a different electrostatic interaction between Ogamma of Thr(E11) and the bound CO molecule. Molecular analysis indicates a more favorable interaction of the bound CO with Thr Ogamma in the beta-subunit heme pocket.