Oxytocin: A Conditional Anorexigen whose Effects on Appetite Depend on the Physiological, Behavioural and Social Contexts.

Central oxytocin suppresses appetite. Neuronal activity and the release of oxytocin coincide with satiation, as well as with adverse events (e.g. hyperosmolality, toxicity or excessive stomach distension) that necessitate an immediate termination of eating behaviour. Oxytocin also decreases consumption driven by reward, especially as derived from ingesting carbohydrates and sweet tastants. This review summarises current knowledge of the role of oxytocin in food intake regulation and highlights a growing body of evidence showing that oxytocin is a conditional anorexigen [i.e. its effects on appetite differ significantly with respect to certain (patho)physiological, behavioural and social contexts].

Impact of surgical severity and analgesic treatment on plasma corticosterone in rats during surgery.

Tissue injury and anaesthesia during surgery induce a stress response associated with increased glucocorticoid secretion from the adrenal glands. This response alters the normal physiology and may cause postoperative morbidity, as well as affect the results during acute experiments. The aim of the present investigation was to study the effect of surgical severity and analgesic treatment on circulating corticosterone in male Sprague-Dawley rats. Male rats were treated with either lidocaine infiltrated during surgery, buprenorphine (0.05 or 0.1 mg/kg subcutaneously) or saline subcutaneously. Each treatment group was subjected to either arterial catheterisation or arterial catheterisation and laparotomy. A catheter was inserted in the common carotid artery and blood was collected during surgery and during anaesthesia 6 h after surgery. Lidocaine treatment reduced the corticosterone levels compared to saline treatment after catheterisation but not after laparotomy. Buprenorphine treatment reduced the corticosterone levels during the first hour after surgery after both catheterisation and laparotomy. The higher buprenorphine dose led to an earlier and more pronounced reduction, especially after laparotomy. In the present study, the corticosterone response during surgery in laboratory rats is correlated with the severity of the procedure, and buprenorphine reduces the surgical stress response more effectively than lidocaine treatment.

The identification of high-school dropouts identified as learning disabled: evaluating the utility of a discriminant analysis function.

This study examined the utility of a linear discriminant function to distinguish between students identified as learning disabled (LD) who had either been released from high school under codes suggestive of school dropout (n = 213) or graduation (n = 92). The discriminant function was comprised of six variables--student ethnicity, reading ability, family intactness, family socioeconomic status, school transfers, and school-initiated interruptions. The analysis determined that differences between the LD dropout sample and LD graduate sample were sufficient to allow for a discrimination between the groups. On the basis of group differences the discriminant function that was constructed correctly classified 83% of the school dropouts and 46% of the school graduates, for an overall 73% accuracy rate. Those factors contributing most to the function were the number of district-initiated interruptions, school transfers, and family intactness. Based on the findings, implications for school districts and future research are noted.

The effect of scale manipulations on validity: targetting frequency rating scales for anticipated performance levels.

A common problem with standard five-point frequency rating scales is their inability to differentiate between objects within a relatively narrow band of the rating dimension. Two alternatives for increasing a scale's ability to reflect existing differences are: increasing the number of positions on the rating scale, or packing the rating scale with quantifiers from a particular portion of the frequency dimension. In this study, three types of rating scale - a standard five-point balanced scale, a longer nine-point balanced scale, and a five-point packed scale - were used to rate two videotaped samples of behaviour, one displaying performance levels from 10% to 100% and the other from 70% to 90%. Each subject's ratings were correlated with true performance levels in each sample of behaviour as a measure of validity. Results showed that for ratings of the wide range of behaviour all three types of scales provided average correlations between the ratings and actual frequencies of the event which exceeded 0.90, with the longer nine-point scale yielding a significantly higher mean correlation than the other two scales. For ratings of the narrow performance range, the nine-point scale provided the highest correlation with the actual frequencies, followed by the packed scale and the standard five-point balanced scale. All differences were significant. Findings suggest that increasing the number of scale positions can significantly increase the validity of ratings obtained. Also, though to a lesser degree, validity of ratings may be enhanced in a shorter scale by using quantifiers from the portion of the frequency continuum where performance are anticipated to lie.

Factors associated with dysphonia in high school cheerleaders.

Questionnaire responses that encompassed the severity of acute, cheering-related dysphonia, typical vocal use, vocal history, medical history, smoking and drinking behaviors, and A-Scale personality characteristics were obtained from 146 female high school cheerleaders. Multiple-regression analysis was chosen to examine the degree to which the dysphonia severity items could be associated with the remaining items. The results indicated that acute, cheering-related dysphonia may be preceded or accompanied by a compact set of clinical signs that could be incorporated easily into a screening protocol for prospective cheerleaders.

Applicability of the Parcel-Meyer Children's Health Locus of Control Scale.

Locus of control has emerged as an important outcome variable in many health education programs. This study evaluated one instrument designed to measure this construct. Responses to the Parcel-Meyer Children's Health Locus of Control Scale from two groups of sixth grade students were collected to consider fit of the items to the underlying theoretical model and invariance of the finding from different populations. Factor structures from the two groups did not match one another or Levenson's model. Several items did not have any major loadings. Lack of fit and variance of the results is discussed in terms of the items being inappropriate for this age group, since seven and nine of the 20 items had almost no item variance with 90% or more of students responding with the internal answer. Revision of the scale is recommended.

A critical reexamination of the adolescent alcohol involvement scale.

The AAIS and data by Mayer and Filstead to support it are critically analyzed. The lack of common variance among items is believed to be due to poorly constructed and unordered response options to many items. The primary recommendation is not to use the scale until it is revised to ensure that individual items as well as the scale produce meaningful results.

A test of the dimensionality assumptions of Rotter's Internal-External scale.

Examined two assumptions about the dimensionality of Rotter's I-E scale: First, the bipolarity of the two statements within each item pair; second, the unidimensionality of the overall construct. A revised I-E scale was constructed in which each of the statements from the original I-E scale was presented separately and the 367 subjects could accept or reject them independently. Correlations between statements within item pairs were low anti negative with only seven exceeding a value of -.20. The responses to the statements were factor analyzed resulting in six interpretable factors when rotated. Of the 23 item pairs, there were 11 pairs which loaded on the same factor in opposite directions while the other 12 loaded on different factors or on the same factor but in the same direction. A subsample consisting of 152 subjects also took the original I-E scale. The correlations between factor scores on the 6 factors and the original I-E score varied from .15 to .52. Both assumptions regarding Rotter's I-E scale were found untenable. Instead, it is suggested that the forced choice format be abandoned and the construct be thought of as a second order factor.

SOCIAL DESIRABILITY AND THE TSC MMPI SCALES.

The seven Minnesota Multiphasic Personality Inventory (MMPI) scales developed by Tryon, Stein, and Chu were intercorrelated and factor analyzed by the method of principal components. Included in the analysis were three marker scales for the first three principal components of the MMPI: the SD scale, the R scale, and the L scale, respectively. All of the TSC scales had loadings of .61 OT higher on the first principal component marked by the SD scale with a loading of -.90. The results show that there is con- siderable redundancy in the seven TSC scales and that each of lthe scales has its largest loading on the first principal component.

SOCIAL DESIRABILITY AND THE TSC SCALES: A REPLICATION AND REPLY TO STEIN.

A replication of a study by Edwards, Klockars, and Abbott, 1970, using Tryon's sample, showed that each of the seven TSC scales had its highest loading on the first principal component. The results are in agreement with those obtained with a college sample.