Individual differences in the reactivity of young infants.

Although reports of individual differences in reactivity have recently emerged in the literature, information is still lacking on the ontogeny and stability of this phenomenon over the first months of life. To address this issue, the responses of 40 newborns to PKU screening at 2 days of age were videorecorded. At 2 months, when the infants received their first DPT shot, their behavior in response to the inoculation was also videorecorded. Besides duration of crying, the intensity of fussing and grimacing was determined. Irrespective of birth characteristics, measures of reactivity were related over the first 2 months of extrauterine life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regional differences in anti-Negro prejudice.

"Public opinion polling techniques were employed with 366 randomly selected respondents in eight roughly matched communities in the North and South to investigate anti-Negro prejudice… . in anti-Negro prejudice, externalizing personality findings are of equal importance in the North and South, and socio-cultural and social adjustment factors are considerably more important in the South and account for the sharp differences in the regions." 30 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Loss of water from the stratum corneum induces epidermal DNA synthesis in hairless mice

Many clinical studies have shown that low humidity has a deleterious effect on skin, but the mechanisms involved are poorly understood. To clarify the changes that occur in skin, we examined epidermal cell proliferation in mice kept in a dry (relative humidity < 10%) or a moist (relative humidity > 90%) environment. In animals exposed to low humidity, epidermal DNA synthesis started to increase within 12 h, reaching twice the original level, and the increased level was maintained for up to 5 days. The transepidermal water loss (TEWL) of mice kept for 12 h in the dry environment was the same as that of mice kept in the moist environment, but the skin conductance was lower. The increase in epidermal DNA synthesis following exposure to the dry environment was inhibited by topical application of petrolatum. It is concluded that loss of water from the stratum corneum induces epidermal cell proliferation within 12 h, and this change occurs in the absence of apparent cutaneous barrier dysfunction.     

Groupthink and uncertainty orientation: Personality differences in reactivity to the group situation.

Groupthink theory explains how situational conditions influence group decision making. The authors predict that certainty-oriented (CO) groups show more groupthink than do uncertainty-oriented (UO) groups under closed- rather than open-leadership conditions, this difference being greater under high- rather than low-cohesion conditions. Groupthink can be diminished by avoiding their leader's biased information. The authors asked 68 groups of 4 to decide the fate of a legal case. They found that CO groups are more influenced by situational conditions than are UO groups and that COs make fewer biased decisions with open- rather than closed-leadership conditions and discuss more facts and take more time under high rather than low cohesion. Cohesion interacts with personality to affect group processes but not the decision outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Race differences in stress-induced reactivity in young adults.

Studied the cardiovascular response to the stress of mental arithmetic in 121 young Black and White adults. Stress-induced reactivity was studied before and following 14 days of oral sodium loading (10 gm NaCl per day). Marginal hypertensives, both Black and White, had greater systolic blood pressure (SBP) levels and greater diastolic BP levels in response to stress. Whites had a greater SBP level during mental stress than Blacks and greater reactivity. The prevalence of sodium sensitivity was greater in Blacks (37.3%) than in Whites (18.4%). Sodium loading did not augment the BP reactivity to the mental stress in any of the racial or BP groups. Data demonstrate racial variation in the cardiovascular response to centrally medicated adrenergic stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expression of corneodesmosin in the granular layer and stratum corneum of normal and diseased epidermis

The stratum corneum (SC) has long been considered as a sort of inert membrane destined to be shed at the surface of the epidermis. During the last two decades, however, several lines of evidence have been reported, suggesting that active physical and chemical changes take place in the horny layer despite the absence of intracytoplasmic organelles. In particular, processing of filaggrin, replacement of the plasma membrane by a ceramide envelope and constant, progressive modification of extracellular lipid multilayers have been put forward. Recently, attention has focused on the intercellular junctions, which may be involved in the regulation of SC desquamation. Corneodesmosin, a newly discovered protein of s.c. desmosomes (corneodesmosomes), is synthesized at the latest stages of keratinocyte differentiation and persists between the horny cells until desquamation occurs. In the present study, we performed immunohistochemical and immuno-ultrastructural investigations on corneodesmosin expression in various skin lesions characterized by abnormal production and/or retention of the horny layer. Our results suggest that corneodesmosin expression is independent from profilaggrin synthesis. We found corneodesmosin in almost all morphologically recognizable corneodesmosomal structures and specifically those which persisted up to the SC surface. Hyperkeratotic lesions which are characterized by an increased number of junctions showed intense immunoreactivity with anticorneodesmosin antibody. A complete absence of corneodesmosin was not observed in any disease. This finding, together with our previous biochemical studies, suggests that corneodesmosin may exert a protective function against proteolytic degradation of corneodesmosomes both in normal skin and in the pathological horny layer.     

Evaluating reactivity to ecological momentary assessment during smoking cessation.

Ecological momentary assessment (EMA) consists of assessing phenomena in real time in the natural environment. EMA allows for more fine-grained analyses of addictive behavior and minimizes threats to internal validity, such as recall biases and errors. However, because of the intensive monitoring involved in EMA, measurement reactivity is a concern. To test whether EMA with palmtop personal computers induces reactivity, the authors compared smoking-related outcomes between smokers using EMA and those not using EMA during a quit attempt. The use of no-EMA control groups has been rare in reactivity investigations to date. The EMA protocol included event-contingent assessments (smoking episodes, urge episodes) and random assessments. Outcomes included biologically confirmed abstinence and self-report measures of withdrawal, self-efficacy, motivation, affect, and temptations. Participants were smokers motivated to quit (N = 96). They were randomized to 1 of 3 groups: EMA for the week preceding a planned quit date, EMA for the week following the quit date, and no EMA. Abstinence rates did not differ between the groups at Day 7 or at Day 28 postcessation. For the 20 subscales assessed at each of 3 assessment times, there were significant differences between participants with and without EMA experience for 3 subscales at the 1st of 3 assessment times, and significant differences for 3 different subscales at the 3rd assessment time. These differences suggest some reactivity to EMA, although the inconsistent pattern across time indicates that further research is needed to definitively conclude that EMA induces reactivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bias in the assessment of gender differences.

Comments on A. H. Eagly's (see record 1995-21141-001) discussion of gender differences in behavior, taking the position that comparisons are actually larger than presented because indices used to gauge these magnitudes have not been corrected for study imperfections or are otherwise inappropriate. The author examines 3 practices that result in leveling bias. (1) The practice of using raw indices of effect size as terminal values, (2) inappropriate effect size measure used when gender differences are examined in the context of a randomized block design, and (3) the practice of setting effect sizes at zero when they are not reported or derivable in a primary study because of statistically nonsignificant results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new HPLC-based method for the quantitative analysis of inner stratum corneum lipids with special reference to the free fatty acid fraction

The inner stratum corneum is likely to represent the location of the intact skin barrier, unperturbed by degradation processes. In our studies of the physical skin barrier a new high-performance liquid chromatography (HPLC)-based method was developed for the quantitative analysis of lipids of the inner stratum corneum. All main lipid classes were separated and quantitated by HPLC/light scattering detection (LSD) and the free fatty acid fraction was further analysed by gas-liquid chromatography (GLC). Mass spectrometry (MS) was used for peak identification and flame ionization detection (FID) for quantitation. Special attention was paid to the free fatty acid fraction since unsaturated free fatty acids may exert a key function in the regulation of the skin barrier properties by shifting the physical equilibrium of the multilamellar lipid bilayer system towards a noncrystalline state. Our results indicated that the endogenous free fatty acid fraction of the stratum corneum barrier lipids in essence exclusively consisted of saturated long-chain free fatty acids. This fraction was characterized as a very stable population (low interindividual peak variation) dominated by saturated lignoceric acid (C24:0, 39 molar%) and hexacosanoic acid (C26:0, 23 molar%). In addition, trace amounts of very long-chain (C32-C36) saturated and monounsaturated free fatty acids were detected in human forearm inner stratum corneum. Our analysis method gives highly accurate and precise quantitative information on the relative composition of all major lipid species present in the skin barrier. Such data will eventually permit skin barrier model systems to be created which will allow a more detailed analysis of the physical nature of the human skin barrier.     

Instrumentality effects in the assessment of racial differences in self-esteem.

Previous studies of racial differences in self-esteem have led to highly disparate and confusing results. 291 Black and 444 White 7th and 10th graders were administered the Self-Esteem Inventory, Tennessee Self-Concept Scale, Otis-Lennon Mental Ability Test, and Iowa Test of Basic Skills. Results show that the effects of the measuring instrument as well as those of preexisting individual differences in academic and demographic characteristics are very great. It is suggested that these effects may be sufficient, in many cases, to explain the disparate results of earlier studies. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and gender differences in cardiac reactivity and subjective emotion responses to emotional autobiographical memories.

This research reports age and gender differences in cardiac reactivity and subjective responses to the induction of autobiographical memories related to anger, fear, sadness, and happiness. Heart rate (HR) and subjective state were assessed at baseline and after the induction of each emotion in 113 individuals (61 men, 52 women; 66% European American, 34% African American) ranging in age from 15 to 88 years (M = 50.0; SD = 20.2). Cardiac reactivity was lower in older individuals; however, for anger and fear, these age effects were significantly more pronounced for the women than the men. There were no gender differences in subjective responses, however, suggesting that the lower cardiac reactivity found among older people is dependent on gender and the specific emotion assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological reactions to films by chronic schizophrenics: II. Individual differences in resting levels and reactivity.

Resting skin-resistance, heart-rate, and reactivity data to 1 of 2 tension-arousing films were obtained from 2 normal comparison groups and a sample of drug-free chronic schizophrenics. The schizophrenics were subdivided into 3 subsamples on the basis of the number of deviant associations given to a word-association test. The resting skin-resistance data failed to discriminate between normals and schizophrenics; however, meaningful differences were found among the schizophrenic subsamples such that increasing thought disturbance was associated with increasing basal resistance levels. Basal heart-rate data did indicate faster heart rate for all schizophrenic subsamples compared with both normal groups. Reactivity data also indicated different results for the 2 indexes. Skin-resistance indexes failed to indicate any differences between schizophrenics and normals or among the schizophrenic samples. 1 heart-rate index suggested less reactivity for schizophrenics than for normals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of stochastic modeling to the assessment of group and individual differences in cognitive functioning.

This article begins with a guiding schema of relations among cognitive science, clinical science, and assessment technology. Emphasis is placed on stochastic modeling of cognitive processes. Basic models are adjusted so as to parsimoniously accommodate performance deviations occurring with psychopathology. Modified portions of models indicate functions affected by disorder, whereas portions remaining intact indicate spared functions. Findings from clinical cognitive science are applied to the individual case using Bayesian procedures. Methods are instantiated with respect to cognitive psychopathology of paranoid schizophrenia. The authors address observations and issues arising from this application, including integration of these methods with current assessment practices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in using source-relevant cues.

Ss heard words originating from 2 speakers and later decided which of the 2 speakers said the words. Older adults had difficulty with source monitoring when perceptual cues from 2 sources were similar (2 female speakers), but this difficulty was overcome when perceptual cues were distinctive (a male and a female speaker) and were the only salient cues to source. Older adults also benefited from distinctive spatial cues when these were the only salient cues to source. Older adults, however, experienced difficulties in using multiple cues (both perceptual and spatial) to source effectively, whereas younger adults were able to use multiple cues to enhance their source-monitoring performance. It is suggested that age differences in source monitoring result from differential cue utilization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regional differences in the effects of amphetamine withdrawal on dopamine dynamics in the striatum. Analysis of circadian patterns using automated on-line microdialysis

The purpose of the study is to determine the relationship between behavioral symptoms of amphetamine withdrawal and the extracellular concentration of dopamine (DA) in the dorsolateral caudate nucleus and the nucleus accumbens across the entire light-dark cycle. This was accomplished using automated on-line microdialysis sampling in behaving rats. Animals were pretreated with escalating doses of d-amphetamine (or saline) over a 6-week period and then were withdrawn from amphetamine for 3, 7, or 28 days before testing. There were regional differences in the effects of amphetamine withdrawal on the concentrations of DA and DA metabolites in dialysate. Early during withdrawal (3 and 7 days), when animals showed postamphetamine withdrawal behavioral depression (nocturnal hypoactivity), there was a significant decrease in DA and DA metabolites in the dorsolateral caudate nucleus and a disruption in the normal circadian pattern of DA activity. In contrast, there was no effect of amphetamine withdrawal on DA dynamics in the nucleus accumbens. By 28 days after the discontinuation of amphetamine pretreatment, after basal DA in the caudate returned to normal, there was a significant increase in basal DA metabolism in both the caudate and the accumbens. This increase in DA metabolism may be related to the expression of sensitization, including a hypersensitivity to an amphetamine challenge. It is concluded that the role of the dorsal striatum in psychostimulant drug withdrawal syndromes deserves further consideration.     

Sex differences in extracellular and intracellular calcium-mediated vascular reactivity to vasopressin in rat aorta

In rat thoracic aorta, contractile responses to arginine vasopressin are two-fold higher in females than in males. To determine the roles of extracellular and intracellular Ca2+ in this sexual dimorphism in vascular function, vascular reactivity and Ca2+ channel function were examined in thoracic aortae of male and female rats. In the presence of diltiazem (10 microM), maximal contraction to vasopressin was reduced to a greater extent in male (65+/-2%) than in female aortae (38+/-1%). Maximal contractile responses to KCl and Bay K 8644 were similar in male and female aortae. Sensitivity to KCI was slightly but significantly higher in male than in female aorta; in contrast, sensitivity to Bay K 8644 was nearly three-fold higher in males than in females. Removal of the endothelium enhanced sensitivity to KCl similarly in male and female aortae. In the presence of simvastatin (60 microM; an inhibitor of intracellular Ca2+ release), reactivity to vasopressin was reduced substantially in female (42+/-1%) but unaltered in male aortae. Removal of the endothelium enhanced the inhibitory effect of simvastatin in both female (73+/-2%) and male aortae (41+/-2%). These findings demonstrate that male aortae depend more upon extracellular Ca2+ influx, whereas female aortae depend more upon intracellular Ca2+ release for vasopressin-induced contraction.     

Dual-task assessment of age differences in automatic process development.

The present experiment assessed dual-task performance in 20 young (mean age 21) and 20 old (mean age 72) adults. Ss first received extensive single-task practice on consistent and varied search tasks. Next, they received dual-task practice in 2 conditions: (1) varied visual search plus varied memory search and (2) consistent visual search plus varied memory search. In the varied-varied condition, young and old adults showed similar dual-task decrements. These results, along with the current data in the literature, suggest that practice may play an important role in determining age-related dual-task differences (or lack thereof). In the consistent-varied condition, young adults attained single-task performance levels, because they had automatized the consistent task. Old adults were unable to match their single-task performance levels, indicating that they were unable to automatize the consistent task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regional differences in the morphology of the rat subfornical organ

Properties of whole milk and milk fractions from cows fed a diet that gave a greatly increased proportion of unsaturated fatty acid residues (especially of linoleic acid) in the milk lipids were studied, and this milk (high-linoleic milk) was compared with milk from cows on a control diet (control milk). The milk fractions were isolated by high-speed centrifugation of whole milk or cream and were examined by chemical analysis and electron microscopy. During centrifugation the globules of milk fat were disrupted and the membranes (fat-globule 'ghosts') floated as a layer beneath the free lipid. Membrane proteins from the 2 sorts of milk gave the same electrophoretic pattern and the amino acid compositions were the same. Lipid analysis of the membrane fraction from high-linoleic milk showed the expected increase in the proportion of unsaturated fatty acid residues in the neutral lipids, but there was an unexpected decrease in the proportion of unsaturated residues in the membrane phospholipids. No differences were found between high-linoleic and control milk in the ultrastructure of the milk-fat globules or the isolated membranes.     

Regional differences in the arterial response to vasopressin: role of endothelial nitric oxide

Two Epstein-Barr virus (EBV) gene products, latent infection membrane protein 1 (LMP1), expressed mainly in latent infection, and BHRF1, expressed in lytic infection, have the ability to promote cell survival. LMP1 protects human B cells from apoptosis by upregulating expression of Bcl-2 and A20. We have demonstrated that LMP1 transfectants of Jurkat T cells are resistant to apoptosis induced by serum depletion without affecting the Bcl-2/Bax system. Overexpression of LMP1 in epithelial cells inhibits apoptosis induced by TNF-alpha, but not by anti-Fas antibodies. These results indicate that the anti-apoptotic mechanism of LMP1 differs among different cell types. BHRF1 can prevent apoptosis induced by TNF-alpha and anti-Fas antibodies in epithelial cells. The implication of the anti-apoptotic function of LMP1 and BHRF1 is reviewed in relation to EBV infection.