Restriction of working memory capacity during worry.

The authors report the first direct assessment of working memory capacity when people engage in worry. High and low worriers performed a random key-press task while thinking about a current worry or a positive personally relevant topic. High (but not low) worriers showed more evidence of restricted capacity during worry than when thinking about a positive topic. These findings suggest that high worriers have less residual working memory capacity when worrying than when thinking about other topics and, thus, have fewer attentional resources available to redirect their thoughts away from worry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Breech extraction of the second twin. 56 cases and review of the literature

It has been well known that the survivors of retinoblastoma are prone to have osteosarcoma. But the secondary tumor usually occurs in bilateral, hereditary type of retinoblastoma. We report one case of osteosarcoma in a survivor of unilateral, sporadic retinoblastoma. A fourteen year old male presented with a painfully swollen distal forearm of 2 month duration. He had enucleated his left eye 10 years ago due to retinoblastoma with no other adjuvant therapy. We managed him with our conventional protocol and identified deletion of Rb gene from his pathological specimen by using the PCR-RFLP method. This result is unusual for unilateral nonhereditable retinoblastoma and may suggest gene level change even in sporadic cases. And Rb gene study may be helpful for unilateral, sporadic retinoblastoma patient in detecting the possibility of late osteosarcoma.     

Relationships between serum lipids, platelet membrane fatty acid composition and platelet aggregation in type 2 diabetes mellitus

In order to gain further insight into the mechanism of platelet dysfunction frequently reported in diabetes we investigated circulating fatty acids, lipid composition of platelet membrane and platelet function in Type 2 diabetic patients. In these subjects, percentages of C16 : 1n-7 and C18 : 1n-9 in serum phospholipid fraction and of C16 : 1n-7 in serum cholesterol ester fraction were decreased. Moreover, the content of C20 : 4n-6 in serum cholesterol esters was altered in Type 2 diabetic subjects: C18 : 0 and C20 : 3n-6 were increased but C20 : 4n-6 content was similar to controls. Aggregation in vitro did not differ from controls but aggregation in vivo was increased in Type 2 diabetic subjects. No correlation was observed between metabolic parameters -i.e., HbA1, blood glucose, serum triglycerides and total cholesterol, circulating fatty acids and fatty acid content of platelet membrane. A negative linear correlation was found between aggregation in vivo and C20 : 4n-6 content of platelet membrane. Moreover, a U shaped relationship was observed between platelet aggregation in vitro and C20 : 4n-6 content of platelet membrane suggesting that C20 : 4n-6 level should be tightly controlled otherwise platelet hyperreactivity may occur. These results indicate that despite a normal mean C20 : 4n-6 content in the platelet membrane, regulation of C20 : 4n-6 metabolism is less strictly controlled in Type 2 diabetes mellitus and confirm the importance of arachidonic acid platelet content in the regulation of platelet aggregability.     

Enteral absorption in man of eicosapentaenoic acid in different chemical forms

After administering the equivalent of 1 g of eicosapentaenoic acid (EPA) in four different chemical forms, the kinetics of EPA incorporation into plasma triglycerides (TG) were compared by gas liquid chromatography on a capillary column following separation of the lipid fraction by thin layer chromatography. EPA incorporation into plasma TG was markedly smaller and later when EPA was administered as an ethyl ester rather than as EPA free fatty acid, EPA arginine salt or 1,3-dioctanoyl-2-eicosapentaenoyl glycerol (2-EPA). Our results and the data in the literature are compatible with the hypothesis that 2-EPA is absorbed with minimum hydrolysis and escapes random distribution between the other positions of the glycerol molecule during the absorption process.     

Predictors of intention to reduce stroke risk among people at risk of stroke: An application of an extended health belief model.

Purpose: To examine predictors of intention to reduce stroke risk in a sample of at risk individuals through the application of an expanded Health Belief Model. Research Method: Predictors included stroke knowledge, demographic variables, beliefs about stroke, and measures of subjective norm and self-efficacy. The dependent variable was intention to reduce stroke risk. Of the 276 surveys distributed to bowling clubs, senior citizens clubs or retirement villages, 101 surveys were returned. Data from 76 of these respondents were used for analysis. Results: With regard to exercise intention, a pattern of significant correlations between HBM variables, subjective norm, and self-efficacy was observed. Results of multiple hierarchical regression analyses showed that perceived benefits of undertaking exercise and self-efficacy in relation exercise were the two most important determinants of exercise intentions. Conclusions: Findings suggest that health beliefs may play an important role in stroke prevention. Practice Implications: Stroke education and prevention programs that selectively target beliefs about the perceived benefits of, and self-efficacy related to, exercise to reduce stroke risk may prove most efficacious. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evolution of pore structure and active surface areas of coal and char during hydrogenation

A Belgian coal (Beringen) has been used in a fundamental study of the changes in pore structure and active surface area during hydrogenation. The coal was devolatilized under N₂ and then hydrogenated at constant temperature up to various conversion yields. Reactivities of the chars were determined by isothermal thermogravimetric analysis. Changes in total surface area, calculated from CO₂ adsorption isotherms at 298 K, and in macropore distribution, obtained by mercury penetration, were found to lead to the same conclusion. In the first reaction stage, the preponderant phenomenon was the opening of previously closed micropores, induced by the material consumed by the reaction. This stopped completely when conversion yield exceeded 55 wt% when the maximum surface area was observed. Then removal of material from pore walls became predominant, pores were enlarged and pore walls disappeared gradually with increasing hydrogenation yields. Oxygen chemisorption capacities were measured at 383 K and 0.1 MPa air to give a relative indication of the concentration of carbon active sites. Active surface area results were compared to total surface area values and correlated with reaction rates.     

The psychological effects of employment after traumatic brain injury: Objective and subjective indicators.

Objectives: This study examines the effects of objective (level of engagement) and subjective (discrepancy between importance of work and the degree to which work needs are met) indicators of employment on self-reported psychological well-being, quality of life (QoL), and depression for individuals with traumatic brain injury (TBI). Design: Cross-sectional. Setting: Community-based research and training center. Participants: 317 individuals with self-reported TBI under the age of 65 were included in analysis. Main Outcome Measures: Living Life After Traumatic Brain Injury (LLATBI; 1998), Flanagan Scale of Needs (J. C. Flanagan, 1982), Beck Depression Inventory-II (BDI-II; A. T. Beck, R. Steer, & G. Brown, 1996). Results: Only 21% of the present sample experienced similar levels of pre- and postinjury employment. Multiple regressions revealed significant relationships between demographic, objective, and subjective employment indicators and perceived QoL and depression. In addition, significant increments in QoL and depression variance were accounted for by subjective indicators of employment per se. Conclusions: Subjective indicators are additional important measures when assessing the rehabilitation needs and planning treatment for individuals with TBI, as they contribute to further improvements in their QoL and mood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction of the catalytic domain of inositol 1,4,5-trisphosphate 3-kinase A with inositol phosphate analogues

The levels of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] in the cytoplasm are tightly regulated by two enzymes, Ins(1,4,5)P3 3-kinase and type I Ins(1,4,5)P3 5-phosphatase. The catalytic domain of Ins(1,4,5)P3 3-kinase (isoenzymes A, B and C) is restricted to approximately 275 amino acids at the C-terminal end. We were interested in understanding the catalytic mechanism of this key family of enzymes in order to exploit this in inhibitor design. We expressed the catalytic domain of rat Ins(1,4,5)P3 3-kinase A in Escherichia coli as a His- and S-tagged fusion protein. The purified enzyme was used in an Ins(1,4,5)P3 kinase assay to phosphorylate a series of inositol phosphate analogues with three or four phosphate groups. A synthetic route to D-2-deoxy-Ins(1,4,5)P3 was devised. D-2-Deoxy-Ins(1,4,5)P3 and D-3-deoxy-Ins(1,4,6)P3 were potent inhibitors of the enzyme, with IC50 values in the micromolar range. Amongst all analogues tested, only D-2-deoxy-Ins(1,4,5)P3 appears to be a good substrate of the Ins(1,4,5)P3 3-kinase. Therefore, the axial 2-hydroxy group of Ins(1,4,5)P3 is not involved in recognition of the substrate nor does it participate in the phosphorylation mechanism of Ins(1,4,5)P3. In contrast, the equatorial 3-hydroxy function must be present in that configuration for phosphorylation to occur. Our data indicate the importance of the 3-hydroxy function in the mechanism of inositol trisphosphate phosphorylation rather than in substrate binding.     

Optical and physical properties of stratospheric aerosols from balloon measurements in the visible and near-infrared domains. III. Presence of aerosols in the middle stratosphere

The aerosol extinction measurements in the ultraviolet and visible wavelengths by the balloonborne spectrometer Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON) show that aerosols are present in the middle stratosphere, above 25-km altitude. These observations are confirmed by the extinction measurements performed by a solar occultation radiometer. The balloonborne Laboratoire de Météorologie Dynamique (LMD) counter instrument also confirms the presence of aerosol around 30-km altitude, with an unrealistic excess of micronic particles assuming that only liquid sulfate aerosols are present. An unexpected spectral structure around 640-nm observed by SALOMON is also detectable in extinction measurements by the satellite instrument Stratospheric Aerosols and Gas Experiment III. This set of measurements could indicate that solid aerosols were detected at these altitude ranges. The amount of soot detected up to now in the lower stratosphere is too low to explain these measurements. Thus, the presence of interplanetary dust grains and micrometeorites may need to be invoked. Moreover, it seems that these grains fill the stratosphere in stratified layers.