A sensitive microassay reveals marked regional differences in the capacity of rat brain to generate carbon monoxide

Heme oxygenase activity is the sole known physiological source for the production of carbon monoxide (CO), a gaseous messenger candidate. A sensitive radioenzymatic microassay was validated to study regional distribution of heme oxygenase activity within the rat brain. The assay utilized a 14,000 X g supernatant of brain homogenate and [14C]heme as the substrate. Thin layer chromatography revealed that incubation of cerebellar supernatant with (14C]heme yielded a single reaction product, indistinguishable from bilirubin, that was selectively extracted into toluene. Radioactivity in toluene increased linearly in respect to time and added protein, was totally dependent on NADPH and was not detected with boiled homogenate. The reaction was dose-dependently inhibited by Zn-protoporphyrin IX (IC50 0.3 microM) and by an antibody generated against rat NADPH-cytochrome P450 reductase indicating specific involvement of heme oxygenase. As little as 36 fmol [14C]bilirubin/min could be readily detected requiring only microgram-quantities of cerebellar homogenate. Heme oxygenase activity measurements from discrete brain regions revealed for the first time marked differences in enzyme activity with the increasing order: frontal cortex < cerebellum = caudate-putamen < hippocampus = hypothalamus = colliculi < trapezoid body. This activity pattern closely reflects the distribution of immunoreactivity and mRNA for heme oxygenase. The present microassay should offer a valuable tool for studies directly assessing a possible role for CO in neural signaling.     

Social adjustment of children with and without learning disabilities in integrated classrooms.

The social adjustment of 46 children with learning disabilities (LDs) and 199 children without LDs who were integrated full-time in 3rd-grade classrooms was examined. No differences were found in the proportions of children with LDs and without LDs across accepted and unpopular sociometric groups. Two thirds of children with LDs had at least 1 reciprocal friend, and more than half had a friendship with a classmate without LDs. Girls with LDs received the highest number of negative nominations and were the least preferred. Group comparisons of socially adjusted and nonadjusted children, with and without LDs, showed that teachers perceived the socially adjusted children with LDs to be less socially and academically competent than adjusted children with LDs. Results are discussed in terms of the effects of educational setting and classroom composition on children's social adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Outcome and attributional disagreements between students and their teachers.

Teachers' and students' outcome interpretations, attributions for the outcome, expectancies of future exam outcome, and perceptions concerning instrumental actions were compared after a math exam. One third of the students disagreed with their teacher about whether the exam outcome was a success or a failure; teachers evaluated the outcomes more positively than did students. When the students and the teachers agreed on the outcome interpretation, their mean attributional ratings did not apparently differ. However, ratings of teacher–student dyads revealed considerable attributional differences. After perceived failure, the dyadic attributional disagreements were related to disagreements concerning the instrumental actions needed for future success. Also, given failure, the more discrepant the dyad members' views of the stability of the attributions were, the more discrepant were their future expectations. Disagreements between students and teachers concerning outcome evaluation, causal perception, and future expectancy are discussed in terms of students' and teachers' biases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computed tomographic evaluation of retrosternal adhesions after pericardial substitution

BACKGROUND: Reoperative median sternotomy can result in cardiac injury and serious bleeding, with the rate ranging from 2% to 6%. Closure of the native pericardium can maintain a preventing plane of cleavage. In patients in whom primary pericardial closure is not possible, several substitutes have been tried with variable results. We conducted a prospective study to evaluate the clinical feasibility of polytetrafluoroethylene and polyglycolic acid patches as pericardial substitutes, using computed tomography for imaging the postoperative state of the retrosternal space. METHODS: The basic population comprised 540 patients who were scheduled for coronary artery bypass grafting, and 52 of them who met the research criteria were chosen for computed tomographic evaluation after 5 years after the primary operation. RESULTS: As a substitute, polytetrafluoroethylene seemed to be less adhesive to the posterior surface of the sternum. Total adhesion scores were also statistically significant (p < 0.001) to the advantage of polytetrafluoroethylene over polyglycolic acid as a pericardial substitute. CONCLUSIONS: Polytetrafluoroethylene membrane seems to be capable of minimizing retrosternal adhesion formation and thus it may protect the heart during subsequent reoperative sternotomy.     

Perceptions of the school social context across the transition to middle school: Heightened sensitivity among Latino students?

The current study was designed to examine the ways in which perceived behavioral norms among grade mates and school social climate vary across the transition to middle school. The main goals of the study were to test whether Latino students may be more sensitive to the school social climate than White students and whether perceived behavioral norms might help explain this association. Cross-sectional analyses comparing Latino and White students (N = 383) revealed that perceptions of school social climate and behavioral norms became more negative across the middle school transition. Multiple regression analysis showed that school climate perceptions predicted self-reported academic compliance and rule breaking only for Latino students. Mediational analysis revealed that the association between perceived climate and self-reported rule breaking was partially accounted for by perceptions of behavioral norms for rule breaking only among Latino students. Taken together, the results suggest that compared with White students, Latino students are more sensitive to school social climate as it relates to their school conduct. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Peer harassment, psychological adjustment, and school functioning in early adolescence.

The relations between peer harassment, psychological adjustment, and school functioning were investigated with an ethnically diverse sample of middle school students. A conceptual model, which proposed that self-perceived peer harassment predicts psychological adjustment (loneliness, depression, and self-worth), which in turn predicts school outcomes (GPA and attendance), was tested using concurrent data (n?=?244). Structural equation modeling supported the proposed model. Longitudinal analyses with a subsample (n?=?106) of students revealed that subjective self-views of victimization were moderately stable across a 1-year period. Comparisons across stable and unstable victim groups suggested that concurrent (rather than earlier or chronic) perceptions of victimization predicted loneliness and self-worth. Finally, changes in subjective perceptions of victimization, self-worth, and loneliness across the 1-year period predicted subsequent GPA, absenteeism, and teacher-rated social adjustment. Findings are discussed in terms of the short- and long-term effects of peer harassment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amplification Facilitators and Pre‐Processing Methods for PCR Detection of Strictly Anaerobic Beer‐Spoilage Bacteria of the Class Clostridia in Brewery Samples

The aim of this study was to evaluate easy pre‐PCR processing procedures to allow rapid and reliable detection of strictly anaerobic beer‐spoilage bacteria throughout the brewing process by end‐point and real‐time PCR techniques. The efficiencies of the new procedures were evaluated using spiked brewery samples and specific PCRs for the target group bacteria. We found for the first time that the inclusion of 0.25% (w/v) bovine serum albumin (BSA) or 0.5% (w/v) polyvinyl pyrrolidone (PVP) in the end‐point PCR mixture reduces the inhibiting effect of brewery sample extracts (3–10%, v/v) on PCR. Membrane filtration with a PVP or a sodium tri‐polyphosphate‐EDTA wash, and cross‐flow filtration were the most promising new methods to reduce inhibitors from beer samples before cell lysis. Together with BSA, they allowed the analysis of 10% (v/v) of crude extracts instead of <3% (v/v). Moreover, we developed a one‐hour procedure to prepare target DNA from process samples containing brewer's yeast. It involved removal of inhibitors by a two‐step centrifugation followed by physical disruption of cells. The detection limit of the procedure was 10¹‐10³ CFU/mL. The developed procedures help to reduce the risk of partial or complete PCR failure due to inhibition and target DNA losses, with minimal sample handling.     

Group-specific PCR-RFLP and real-time PCR methods for detection and tentative discrimination of strictly anaerobic beer-spoilage bacteria of the class Clostridia

The strictly anaerobic brewery contaminants of the genera Pectinatus, Megasphaera, Selenomonas and Zymophilus in the class Clostridia constitute an important group of spoilage bacteria of unpasteurised, packaged beers. The aim of this study was to develop and evaluate group-specific PCR methods to detect and differentiate these bacteria in beer. A group-specific primer pair targeting a 342-bp variable region of the 16S rRNA gene was designed and evaluated in end-point PCR with gel electrophoresis and in real-time PCR with SYBR Green I dye. Significant cross-reactions with DNAs from any of the forty-two brewery-related, non-target microbes or from real brewery samples were not detected in either PCR system. The group-specific end-point and real-time PCR products could be differentiated according to species/genus and spoilage potential using restriction fragment length polymorphism (KpnI, XmnI, BssHII, ScaI) and melting point curve analysis, respectively. In combination with a rapid DNA extraction method, the PCR reactions detected ca 10(0)-10(3) CFU per 25 ml of beer depending on the strain and on the PCR system. The end-point and real-time PCR analysis took 6-7 h and 2-3 h, respectively. Pre-PCR enrichment of beer samples for 1-3 days ensured the detection of even a single cultivable cell. The PCR and cultivation results of real brewery samples were mostly congruent but the PCR methods were occasionally more sensitive. The PCR methods developed allow the detection of all the nine beer-spoilage Pectinatus, Megasphaera, Selenomonas and Zymophilus species in a single reaction and their differentiation below group level and reduce the analysis time for testing of their presence in beer samples by 1-2 days. The methods can be applied for brewery routine quality control and for studying occurrence, diversity and numbers of the strictly anaerobic beer spoilers in the brewing process.     

Bran fermentation as a means to enhance technological properties and bioactivity of rye

Response surface methodology was applied to study the effects of fermentation on the levels of phytochemicals (folates, phenolic compounds, alkylresorcinols) and on the solubilization of pentosans in rye bran from native and peeled grains. Furthermore, the microbial composition of the brans before and after fermentation was studied. Peeling reduced the microbial load and lower microbial counts were detected in the fermentation experiments carried out with the bran from peeled grains. High temperature and long fermentation time favoured the growth of indigenous lactic acid bacteria (LAB), and a diverse microbial community was detected. The brans contained low levels of aerobic spore-forming bacteria, but their number was not increased during the fermentations. Fermentation of both brans increased the levels of folates, easily extractable total phenolics and free ferulic acid. During fermentation of bran from native grains, the levels of alkylresorcinols slightly increased but during fermentation of bran from peeled grains they decreased. Significant increase in soluble pentosans was established in both types of rye bran fermentations. Enhanced bioactivity and solubilization of pentosans with limited microbial growth were obtained after 12-14 h fermentation at 25 degrees C. The results suggest that fermentation is a potential bioprocessing technology for improved technological properties and bioactivity of rye bran.