Patients'' and relatives'' opinion and knowledge about electroconvulsive therapy: implications for nursing

This study examines sources of motivation to seek treatment. Participants were 105 male alcoholics and their non-alcoholic female partners who participated in a study of three different approaches to the conjoint treatment of alcoholism. Participants' sources of motivation were coded from responses to questions at the initial clinical screening interview. Sources of motivation were classified as "internal" or "external." More participants had internal sources of motivation (74%) than external sources. Participants with internal sources of motivation scored higher on the Michigan Alcoholism Screening Test than participants with external sources of motivation, but did not differ on other measures of pretreatment severity of alcohol problems. About half of the participants (53%) cited their partner as a primary source of motivation to seek treatment. Other sources of motivation cited were: increasing problems with alcohol, mental health problems, and physical health problems. There was greater variability among internal sources of motivation than among external sources of motivation. Participants' partners but not the male participants themselves, experienced an increase in marital satisfaction from pre- to within-treatment when the participant was motivated to come to treatment by his partner.     

Ovine brain natriuretic peptide in cardiac tissues and plasma: effects of cardiac hypertrophy and heart failure on tissue concentration and molecular forms

It is well established that lymphoid dendritic cells (DC) play an important role in the immune system. Beside their role as potent inducers of primary T cell responses, DC seem to play a crucial part as major histocompatibility complex (MHC) class II+ "interdigitating cells" in the thymus during thymocyte development. Thymic DC have been implicated in tolerance induction and also by some authors in inducing major histocompatibility complex restriction of thymocytes. Most of our knowledge about thymic DC was obtained using highly invasive and manipulatory experimental protocols such as thymus reaggregation cultures, suspension cultures, thymus grafting, and bone marrow reconstitution experiments. The DC used in those studies had to go through extensive isolation procedures or were cultured with recombinant growth factors. Since the functions of DC after these in vitro manipulations have been reported to be not identical to those of DC in vivo, we intended to establish a system that would allow us to investigate DC function avoiding artificial interferences due to handling. Here we present a transgenic mouse model in which we targeted gene expression specifically to DC. Using the CD 11c promoter we expressed MHC class II I-E molecules specifically on DC of all tissues, but not on other cell types. We report that I-E expression on thymic DC is sufficient to negatively select I-E reactive CD4+ T cells, and to a less complete extent, CD8+ T cells. In contrast, it only DC expressed I-E in a class II-deficient background, positive selection of CD4+ T cells could not be observed. Thus negative, but not positive, selection events can be induced by DC in vivo.     

A Community‐Level,Mesoscale Analysis of Fish Assemblage Structure in Shoreline Habitats of a Large River Using Multivariate Regression Trees

The mesoscale (10⁰–10² m) of river habitats has been identified as the scale that simultaneously offers insights into ecological structure and falls within the practical bounds of river management. Mesoscale habitat (mesohabitat) classifications for relatively large rivers, however, are underdeveloped compared with those produced for smaller streams. Approaches to habitat modelling have traditionally focused on individual species or proceeded on a species‐by‐species basis. This is particularly problematic in larger rivers where the effects of biological interactions are more complex and intense. Community‐level approaches can rapidly model many species simultaneously, thereby integrating the effects of biological interactions while providing information on the relative importance of environmental variables in structuring the community. One such community‐level approach, multivariate regression trees, was applied in order to determine the relative influences of abiotic factors on fish assemblages within shoreline mesohabitats of San Pedro River, Chile, and to define reference communities prior to the planned construction of a hydroelectric power plant. Flow depth, bank materials and the availability of riparian and instream cover, including woody debris, were the main variables driving differences between the assemblages. Species strongly indicative of distinctive mesohabitat types included the endemic Galaxias platei. Among other outcomes, the results provide information on the impact of non‐native salmonids on river‐dwelling Galaxias platei, suggesting a degree of habitat segregation between these taxa based on flow depth. The results support the use of the mesohabitat concept in large, relatively pristine river systems, and they represent a basis for assessing the impact of any future hydroelectric power plant construction and operation. By combing community classifications with simple sets of environmental rules, the multivariate regression trees produced can be used to predict the community structure of any mesohabitat along the reach. Copyright © 2015 John Wiley & Sons, Ltd.     

The subunit structure of alpha-acetohydroxyacid isomeroreductase from Salmonella typhimurium

Alpha-Acetohydroxyacid isomeroreductase from Salmonella typhimurium has a native molecular weight of 220,000. The constituent polypeptide chains exhibit anomalous but unimodal electrophoretic migration on sodium dodecyl sulfate-urea polyacrylamide gels. The subunit molecular weight, determined by sedimentation equilibrium in 6 M guanidine hydrochloride, is 57,000. The apparent tetrameric nature of the native enzyme was confirmed by determining the types of oligomers formed upon cross-linking with dimethylsebacimidate. Analysis of tryptic peptides suggests that the polypeptide chains have an identical amino acid sequence. Carbohydrate analysis, ultraviolet absorption spectrum, and atomic absorption spectrum are consistent with the lack of cobalamine and cobalt. The Michaelis constants are as follows: alpha-acetolactate, 2.9 x 10-4 M; alpha-aceto-alpha-hydroxybutyrate, 7.8 x 10-4 M; NADPH, 1.5 x 10-5 M; Mg2+, 7.7 x 10-4 M. The catalytic constants (molecules of substrate catalyzed per min per molecules of enzyme) for alpha-acetolactate and alpha-aceto-alpha-hydroxybutyrate are 1,100 and 4,700, respectively. Comparative tryptic peptide analysis and immunological analysis show that alpha-acetohydroxyacid isomero-reductase and biosynthetic L-threonine deaminase bear no structural relationship and therefore rule out a "shared structure" hypothesis for the putative involvement of L-threonine deaminase in the synthesis of alpha-acetohydroxyacid isomeroreductase.     

Comparative analytical studies of fatty acids of the algaChlorella pyrenoidosa

Gas-liquid chromatography, several versions of paper chromatography, and alkaline isomerization have been applied to one preparation ofChlorella fatty acid methyl esters. GLC outranks other methods in rapidity, reproducibility, and resolving power. The presence of nonvolatile components in the sample can lead to erroneous results. Among PC methods which might arise from autoxidation and polymerization are detected. Esters or acids with 14 or fewer C atoms should be analyzed as nonvolatile derivatives. AI, as used here, introduces a systematic error in the determination of linoleic and linolenic acids. The quantitative results of the methods are in agreement for the major components, which all belong to the C₁₀ and C₁₈ series. A number of minor components have been revealed by GLC and/or PC. They are tentatively identified as <C₁₂, C₁₂, four C₁₄, C₁₅, two C₁₇, C₁₉, three C₂₀, two C₂₂, and C₂₄ acids. Several of these compounds have been found independently by different methods in hydrogenated form or as radioactive esters. This enhances the certainty of their identification. Eurichment by fractional distillation was essential for their detection. Possible losses in their distillation and other considerations make uncertain the assay of most of the minor components by GLC or PC. Work supported in part by grant RG-4226 from the Division of General Medical Sciences of the U. S. Public Health Service and in part by the Hormel Foundation.     

Determination of peak expiratory flow

It is still unknown whether peak expiratory flow (PEF) is determined by "wave speed" flow limitation in the airways. To investigate the influences of airway mechanical properties on PEF, five healthy adults performed maximal forced expiratory effort (MFEE) manoeuvres, in the standard manner and following breathholds at total lung capacity (TLC) of 2 s and 10 s. Oesophageal pressure (Poes) was measured as an index of respiratory effort. Subjects also performed a MFEE following a 10 s breathhold during which intrathoracic pressure was voluntarily raised by a Valsalva manoeuvre, which would increase transmural pressure and cross-sectional area of the extrathoracic airway. Additional MFEEs were performed with the neck fully flexed and extended, to change longitudinal tracheal tension. In separate studies, PEF was measured with a spirometer and with a pneumotachograph. Breathholds at TLC (2 s and 10 s), and neck flexion reduced PEF by a mean of 9.8% (SD 2.9%), 9.6% (SD 1.6%), and 8.7% (SD 2.8%), respectively, when measured with the spirometer. The same pattern of results was seen when measured with the pneumotachograph. These reductions occurred despite similar respiratory effort. Voluntarily raising intrathoracic pressure during a 10 s breathhold did not reverse a fall in PEF. MFEE manoeuvre with neck extension did not result in an increase in PEF, the group mean % changes being -3.0% (SD 5.0%). We conclude that these results do not allow the hypothesis that "wave-speed" (Vws) is reached at PEF to be rejected. A breathhold at TLC could increase airway wall compliance by allowing stress-relaxation of the airway, thus reducing the "Vws" achievable.     

Emerging concepts in the Ras superfamily of GTP-binding proteins

The Ras superfamily of GTP-binding proteins (> 50 members) regulates a diverse spectrum of intracellular processes. These include cellular proliferation and differentiation, intracellular vesicular trafficking, cytoskeletal control, NADPH oxidase function, as well as others. In this review, we describe recent progress and emerging themes in the action and regulation of these important cellular regulatory molecules. Structural studies have provided insight into the function of low molecular weight GTP-binding proteins (LMWGs) as molecular switches, and are defining modes of interaction with associated regulatory molecules. Details of the enzymatic processes involved in the posttranslational processing of LMWGs, and how this processing is important for protein function, are being elucidated. A variety of GTPase activating proteins, GDP/GTP dissociation stimulators, and GDP dissociation inhibitors have been identified, and their ability to determine the activity of LMWG-regulated systems is being worked out. The discovery of multifunctional regulatory molecules has indicated that substantial "crosstalk" between various LMWG may occur. The continuing emergence of additional cellular functions that are regulated by LMWGs, and particularly the recent availability of in vitro analytical systems for studies of the mechanism (or mechanisms) of action of LMWGs, is resulting in a wealth of information about the regulation and integration of cellular signaling, form, and function.     

The influence of the oncogenes NRAS and MYC on the radiation sensitivity of cells of a human melanoma cell line

Activation of certain oncogenes may alter the sensitivity of cells to ionizing radiation. We studied the effect of oncogene activation on the radiation sensitivity of cells of a human melanoma cell line. The cell line IGR39D was transfected with the MYC oncogene, the proto-oncogene NRAS, NRAS activated by a point mutation (61-arginine) or a combination of mutated NRAS and MYC. Single-dose experiments showed a decreased survival after transfection with MYC, wild-type NRAS or mutated NRAS. Co-transfection with MYC and mutated NRAS decreased survival up to 4 Gy, whereas at higher doses no shift in radiosensitivity was seen. Flow cytometry data indicated that differences in radiosensitivity could be explained at least in part by a difference in the distribution of cells in the phases of the cell cycle. After transfection of cells with either NRAS or MYC, the number of cells in G1 phase decreased with a concomitant increase of cells in the G2/M phase. When the cell line transfected with activated NRAS was manipulated so that the distribution of the cells in the phases of the cell cycle resembled th at of the parental line at the time of irradiation, the survival of the cells was improved. Similar experiments with the cell line containing MYC did not result in an alteration of the distribution of the cells in the cycle, or the survival after single-dose fractions, suggesting the presence of a distinct mechanism for influencing radiation sensitivity. Both NRAS and MYC transfection decrease the radiation sensitivity of human melanoma cells, but the underlying mechanisms seem different. In conclusion, transfection with NRAS or MYC alone increases radiation sensitivity while transfection of cells containing NRAS with MYC restores resistance at higher doses.     

A C-terminal fragment of Agouti-related protein increases feeding and antagonizes the effect of alpha-melanocyte stimulating hormone in vivo

Agouti-related protein (Agrp) is present in rat and human hypothalamus and is structurally related to agouti protein. Overexpression of either of these proteins results in obesity. However the effect of exogenous Agrp and its in vivo interaction with alpha-melanocyte stimulating hormone (alphaMSH), the likely endogenous melanocortin 3 and 4 receptor (MC3-R and MC4-R) agonist, have not been demonstrated. We report that 1 nmol of Agrp(83-132), a C-terminal fragment of Agrp, when administered intracerebroventricularly (ICV) into rats, increased food intake over a 24-h period (23.0+/-1.4 g saline vs 32.9+/-2.3 g Agrp, p<0.05). The hyperphagia was similar to that seen when 1 nmol of the synthetic MC3-R and MC4-R antagonist SHU9119 was given i.c.v. (19.6+/-1.8 g saline vs 32.5+/-1.7 g SHU9119, p<0.001). Both Agrp(83-132) and SHU9119 blocked the reduction in 1-h food intake of i.c.v. alphaMSH at the beginning of the dark phase. This effect occurred independently of whether the antagonists were administered simultaneously, or nine hours prior, to the alphaMSH. We have also shown Agrp(83-132) is an antagonist at the MC3-R and MC4-R, with similar inhibition of cAMP activation to that previously reported for the full length peptide. In conclusion, Agrp(83-132) administered i.c.v. increases feeding with long lasting effects and is able to inhibit the action of alphaMSH. This interaction may be mediated by the MC3-R and/or MC4-R.     

Effect of aging on susceptibility of low-density lipoproteins to oxidation

According to the Adult Treatment Panel of the National Cholesterol Education Program, age is a major risk factor for heart disease. To assess the relation between age and LDL oxidizability, we studied copper-mediated LDL oxidation in 13 healthy elderly subjects (> 59 years) and 13 sex-matched healthy young controls (< 30 years). Total and LDL-cholesterol concentrations were increased in elderly subjects. The time course of copper-mediated LDL oxidation showed no significant differences between the two groups as assessed by formation of conjugated dienes, lipid peroxides, and apolipoprotein B fluorescence. Kinetics of LDL oxidation as quantified by lag time, oxidation rate, and maximal oxidation were not significantly different between the elderly and young groups. Although the concentrations of 16:0, 18:0, 18:1, 18:3, and 20:4 and total polyunsaturated fatty acids were significantly higher in the elderly group, LDL fatty acid concentrations were similar in both groups. Lipid-standardized alpha-tocopherol, beta-carotene, and ascorbate concentrations were not significantly different between the two groups. The findings of the present study suggest that in the healthy elderly, LDL oxidation may not be a crucial mediator for atherogenesis.