5-Lipoxygenase-derived oxylipins from the red alga Rhodymenia pertusa.

The lipid extract of the temperate red alga Rhodymenia pertusa has yielded four eicosanoid metabolites, three of which are new natural products. Using principally NMR and MS techniques, their structures were deduced as 5R,6S-dihydroxy-7(E),9(E),11(Z),14(Z)-eicosatetraenoic acid (5R,6S-diHETE), 5R*,6S*-dihydroxy-7(E),9(E),11(Z),14(Z),17(Z)-eicosapentaenoic acid (5R*,6S*-diHEPE), 5-hydroxy-6(E),8(Z),11(Z),14(Z)-eicosatetraenoic acid (5-HETE), 5-hydroxy-6(E),8(Z),11(Z),14(Z),17(Z)-eicosapentaenoic acid (5-HEPE). The co-occurrence of these metabolites strongly suggests that R. pertusa contains a unique 5R-lipoxygenase system acting on both arachidonic and eicosapentaenoic acids.

Quality of early family relationships and individual differences in the timing of pubertal maturation in girls: a longitudinal test of an evolutionary model.

In an 8-year prospective study of 173 girls and their families, the authors tested predictions from J. Belsky, L. Steinberg, and P. Draper's (1991) evolutionary model of individual differences in pubertal timing. This model suggests that more negative-coercive (or less positive-harmonious) family relationships in early childhood provoke earlier reproductive development in adolescence. Consistent with the model, fathers' presence in the home, more time spent by fathers in child care, greater supportiveness in the parental dyad, more father-daughter affection, and more mother-daughter affection, as assessed prior to kindergarten, each predicted later pubertal timing by daughters in 7th grade. The positive dimension of family relationships, rather than the negative dimension, accounted for these relations. In total, the quality of fathers' investment in the family emerged as the most important feature of the proximal family environment relative to daughters' pubertal timing.

Early behavior problems as a predictor of later peer group victimization: moderators and mediators in the pathways of social risk.

This study is a prospective investigation of the predictive association between early behavior problems (internalizing, externalizing, hyperactivity-impulsiveness, immaturity-dependency) and later victimization in the peer group. Teacher ratings of the behavioral adjustment of 389 kindergarten and 1st-grade children (approximate age range of 5 to 6 years-old) were obtained, using standardized behavior problem checklists. These ratings predicted peer nomination scores for victimization, obtained 3 years later, even after the prediction associated with concurrent behavior problems was statistically controlled. Further analyses suggested that the relation between early behavior problems and later victimization is mediated by peer rejection and moderated by children's dyadic friendships. Behavior problems appear to play an important role in determining victimization within the peer group, although the relevant pathways are complex and influenced by other aspects of children's social adjustment.

The relation between mothers' hostile attribution tendencies and children's externalizing behavior problems: the mediating role of mothers' harsh discipline practices.

This study examined relations among mothers' hostile attribution tendencies regarding their children's ambiguous problem behaviors, mothers' harsh discipline practices, and children's externalizing behavior problems. A community sample of 277 families (19% minority representation) living in three geographic regions of the United States was followed for over 4 years. Mothers' hostile attribution tendencies were assessed during the summer prior to children's entry into kindergarten through their responses to written vignettes. Mothers' harsh discipline practices were assessed concurrently through ratings by interviewers and reports by spouses. Children's externalizing behavior problems were assessed concurrently through written questionnaires by mothers and fathers and in the spring of kindergarten and first, second, and third grades through reports by teachers and peer sociometric nominations. Results of structural equations models demonstrated that mothers' hostile attribution tendencies predicted children's future externalizing behavior problems at school and that a large proportion of this relation was mediated by mothers' harsh discipline practices. These results remained virtually unchanged when controlling for initial levels of children's prekindergarten externalizing behavior problems at home.

Peer group victimization as a predictor of children's behavior problems at home and in school.

This study reports a short-term prospective investigation of the role of peer group victimization in the development of children's behavior problems, at home and in school. Sociometric interviews were utilized to assess aggression, victimization by peers, and peer rejection, for 330 children who were in either the third or fourth grade (approximate mean ages of 8-9 years old). Behavior problems were assessed using standardized behavior checklists completed by mothers and teachers. A follow-up assessment of behavior problems was completed 2 years later, when the children were in either the fifth or sixth grade (approximate mean ages of 10-11 years old). Victimization was both concurrently and prospectively associated with externalizing, attention dysregulation, and immature/dependent behavior. Victimization also predicted increases in these difficulties over time, and incremented the prediction in later behavior problems associated with peer rejection and aggression. The results of this investigation demonstrate that victimization in the peer group is an important predictor of later behavioral maladjustment.

Patterns of change in early childhood aggressive-disruptive behavior: gender differences in predictions from early coercive and affectionate mother-child interactions.

The present study focused on mother-child interaction predictors of initial levels and change in child aggressive and disruptive behavior at school from kindergarten to third grade. Aggression-disruption was measured via annual reports from teachers and peers. Ordinary least-squares regression was used to identify 8 separate child aggression trajectories, 4 for each gender: high initial levels with increases in aggression, high initial levels with decrease in aggression, low initial levels with increases in aggression, and low initial levels with decreases in aggression. Mother-child interaction measures of coercion and nonaffection collected prior to kindergarten were predictive of initial levels of aggression-disruption in kindergarten in both boys and girls. However, boys and girls differed in how coercion and nonaffection predicted change in aggression-disruption across elementary school years. For boys, high coercion and nonaffection were particularly associated with the high-increasing-aggression trajectory, but for girls, high levels of coercion and nonaffection were associated with the high-decreasing-aggression trajectory. This difference is discussed in the context of Patterson et al.'s coercion training theory, and the need for gender-specific theories of aggressive development is noted.

alpha-Tocopherol influences in vivo indices of lipid peroxidation in postmenopausal women given fish oil.

Although diets containing fish have been shown to be therapeutically valuable, the vitamin E requirement when large quantities of (n-3) fatty acids are consumed is not known. Additionally, as estrogens may function as an antioxidant, the requirement may be modified in postmenopausal women using hormone replacement therapy (HRT). Consequently, the purpose of this study was to measure the impact of graduated doses of RRR-alpha-tocopheryl acetate (TA) on in vivo indices of lipid peroxidation in postmenopausal women with and without hormone replacement therapy when given a supplement of fish oil. Forty-eight postmenopausal women, half receiving (+HRT) and half not receiving (-HRT) hormone replacement therapy, participated in a four-period, double-blind crossover trial. Each period lasted 5 wk followed by a 4-wk washout interval. During each period, the subjects consumed a 15-g supplement of fish oil and either 0, 100, 200, or 400 mg TA/d in a balanced, single square dosing order. Plasma levels of (n-3) fatty acids were significantly higher after fish oil supplementation; alpha-tocopherol concentration of plasma was significantly higher at each level of supplementation compared with the level without supplementation. Urinary excretion of thiobarbituric acid reactive substances (TBARS) and malondialdehyde, measured as the thiobarbituric-malondialdehyde adduct (TRA-MDA adduct), and the plasma concentration of the adduct were significantly greater after the fish oil supplement. Although urinary TBARS decreased linearly as the dose of TA increases (P < or = 0.05), urinary and plasma concentrations of TBA-MDA adduct did not. This study suggests that the evaluation of highly unsaturated fatty acids as oxidative stressors requires several measures of assessment.

Effects of interaction of RRR-alpha-tocopheryl acetate and fish oil on low-density-lipoprotein oxidation in postmenopausal women with and without hormone-replacement therapy.

We evaluated the effects of RRR-alpha-tocpheryl acetate (alpha-tocopheryl acetate) and hormone-replacement therapy (HRT) on the oxidative susceptibility of low-density lipoprotein (LDL) in postmenopausal women consuming a fish oil supplement. The independent effect of fish oil was also assessed. Forty-eight women, equally divided between women using and not using HRT, participated in a double-blind crossover trial. Each of the four periods lasted 5 wk and was followed by a 4-wk washout interval. During each period all subjects were given a 15-g supplement of fish oil and either 0 (placebo), 100, 200, or 400 mg alpha-tocopheryl acetate daily. LDL resistance to oxidative modification was assessed by calculating lag time, propagation rate, and maximum production of conjugated dienes. Supplementation with fish oil and placebo shortened lag time and slowed propagation rate in women both using and not using HRT. After subjects consumed fish oil, supplementation with alpha-tocopheryl acetate increased plasma and LDL alpha-tocopherol contents significantly and lengthened lag time (at even the lowest concentration) but had no significant effect on propagation rate or maximum production compared with values measured after consumption of fish oil alone. Women not using HRT had faster propagation rates and higher maximum production than women using HRT; after supplementation with fish oil and alpha-tocopheryl acetate these differences prevailed. Supplements as low as 100 mg alpha-tocopheryl acetate/d increase the resistance of LDL to oxidation when fish oil supplements are used. HRT and fish oil supplements may independently affect LDL oxidative susceptibility.

Transcriptional activity of the neuron-specific enolase (NSE) promoter in murine embryonic stem (ES) cells and preimplantation embryos.

Mouse embryonic stem (ES) cells were transfected with a plasmid composed of an E. coli lacZ gene fused to 1.8 kb of rat neuron-specific enolase (NSE) promoter sequences. While this reporter construct had been shown previously to function exclusively in postmitotic neurons and neuro-endocrine cells of transgenic mice, stably transfected ES cell clones unexpectedly displayed beta-galactosidase (beta-Gal) activity in the undifferentiated state. This transcriptional activity of the heterologous NSE promoter was confirmed by the identification of endogenous NSE mRNA in undifferentiated ES cells, mouse morulae and blastocysts. NSE protein, however, could not be found in undifferentiated ES cells. Interestingly, in ES cells which were cultured for 7 days under differentiation conditions in vitro, beta-Gal activity decreased to basal levels consistent with the parallel down-regulation of endogenous NSE mRNA. In contrast, prolonged culture of ES cells under differentiation conditions led to the reappearance of NSE mRNA and beta-Gal activity after 17 days. Significant increases in beta-Gal activity were also observed in ES cells which were cultured either on dishes coated with attachment factors such as laminin and gelatin or in the presence of nerve growth factor (NGF). These results suggest that i) transcriptional control mechanisms regulating neuronal gene expression are present at early developmental stages in the mouse and ii) ES cells provide a useful in vitro model system for the analysis of developmentally regulated cellular and molecular events coupled to neuron-specific enolase promoter activity.

Managing the multicultural laboratory, Part III: Putting the cross-cultural tools to work.

This third article provides two case studies that enable laboratory managers to see how the cross-cultural model postulated by Dr. Geert Hofstede can be practically applied to two important issues--staff training and conflict resolution between employees. In addition, the opinions of several managers from a variety of industries are presented to add realism and perspective. This encourages laboratory managers to step outside the laboratory environment and learn from other managers who have years of experience supervising culturally diverse groups of employees. Part I of this series explained what is meant by "culture" and featured the research-based model set forth by Dutch social psychologist and management consultant, Dr. Geert Hofstede. His four dimensions of culture (Power Distance, Masculinity/Femininity, Individualism/Collectivism, and Uncertainty Avoidance) provide a useful framework for understanding the different values, attitudes, and behaviors exhibited by those of different cultural backgrounds. Part II presented advice in the form of 13 anecdotes from experienced cross-cultural managers. Issues of performance management, interpersonal skills, and language and safety were explored in light of the four dimensions. In this third article, abbreviated reference tables adapted from Hofstede's research are presented that make these cross-cultural data more useful for management decision making. Laboratory managers will receive practical, "real world" advice that will help them to positively resolve conflicts and to take full advantage of staff training opportunities.

Managing the multi-cultural laboratory, Part II: Tools for managing the differences.

This second article provides practical advice from managers in a variety of industries who have first-hand experience as multi-cultural managers. It will help laboratory professionals make practical application of two conceptual models in managing their culturally diverse employees. The advice covers such areas as performance standards, interpersonal skills, language issues, and other management practices. The first article explained what is meant by "culture" and featured the research-based model set forth by Dutch social psychologist and management consultant, Dr. Geert Hofstede. His four dimensions of culture (Power Distance, Masculinity/Femininity, Individualism/Collectivism, and Uncertainty Avoidance) provide a useful framework for assessing the different values, attitudes, and behaviors exhibited by those of different cultural backgrounds. In this article, abbreviated reference tables are presented that make these cross-cultural data more useful for management decision making. Laboratory supervisors can use both the models and the advice to challenge their own built-in cultural biases and to meaningfully interpret some of the attitudes and behaviors of culturally diverse coworkers and employees.

Managing the multicultural laboratory, Part I: Tools for understanding cultural differences.

This article will help laboratory managers better manage their culturally diverse employees by explaining what is meant by "culture" and by presenting a research-based model for assessing the different values, attitudes, and behaviors exhibited by those of different cultural backgrounds. The useful cross-cultural data presented come from an exciting research analysis compiled by Dutch social psychologist and management consultant, Dr. Geert Hofstede. This multi-national corporate study compared the cultures of more than 40 nationalities using four different cultural characteristics. As members of an empirically based profession, laboratory professionals should welcome some hard data about a soft subject. This model will enable laboratory managers to understand their own cultural biases and will interpret some of the attitudes and behaviors of those with different national or ethnic backgrounds. By understanding the elementary principles of culture and by replacing outdated stereotypes with educated generalizations, clinical laboratory managers can take a vital step toward becoming effective multi-cultural managers.

Overcoming the four toughest management challenges. Increase your effectiveness by using situational leadership.

The high-pressure work environment of the clinical laboratory presents significant challenges for managers. Often thrust into supervisory roles without formal management training, laboratory managers must find ways to delegate tasks, mediate conflict, minimize office politics, and build effective teams out of employees who may be quite diverse in their experience levels, motivation levels, and cultural backgrounds. This article explores the concept of situational leadership, which was developed by Ken Blanchard and Paul Hersey, and its applicability within the clinical laboratory. This practical paradigm involves matching one of four distinct management styles to the four development levels of employees. Each leadership style is explained, along with guidelines for giving performance feedback to employees, so that managers can evaluate their own supervisory styles. Finally, step-by-step recommendations for coping with the four management roles of delegator, referee, influencer, and team builder are presented.

Peripheral kappa-opioid modulation of the formalin response: an electrophysiological study in the rat.

The activity of single dorsal horn nociceptive neurones was recorded in the spinal cord of halothane anaesthetized rats. S.c. injection of a 5% formalin solution into the receptive field of these neurones resulted in two peaks of neuronal firing over a period of 60 min. Prior administration of the kappa-opioid receptor agonist U50488H directly into the site of formalin injection caused a dose-dependent decrease in the size of both the first and second peaks of the response which was naloxone reversible. Injection of U50488H into the contralateral paw had no effect on either peak of the formalin response. Injection of the top dose (100 micrograms) of U50488H had no effect on the electrically evoked A beta- or C-fibre responses of the neurone. Neither morphine nor Tyr-D-Ser(Otbu)-Gly-Phe-Leu-Thr (DSTBULET), administered into the receptive field, had any significant effect on either peak of the formalin response. Plasma extravasation in the skin, measured using Evans blue, produced by the formalin injection was not blocked by U50488H. Thus, whilst the spinal responses of this peripheral model of inflammation can be inhibited by peripheral kappa-opioid activation, but not mu- or delta-, plasma extravasation associated with this inflammation is not reduced.

The influence of maternal labels on dietary preferences of spiny mouse weanlings.

To assess the influence of conspecific chemical cues on the development of dietary preferences, spiny mouse (Acomys cahirinus) weanling were tested for their responses to food items that were partially eaten (thus, presumably labeled) by various categories of conspecifics. Consumption of a highly preferred novel food (fresh carrot) labeled by the pups' parents, or mother alone, was greater than that of a clean sample of the same food. The presence of labels emanating from the father or an alien mother had no effect on food consumption. Salient maternal labels that elicit preferential feeding by young appear to be individually unique, therefore allowing pups to recognize such cues emanating from their own mother. The attractive substance that mothers transfer to food items while eating (the maternal label per se) has not been identified, but saliva is a likely candidate.

Opioid receptor ligands in the neonatal rat spinal cord: binding and in vitro depression of the nociceptive responses.

1. Opioid receptors in the neonatal rat spinal cord have been characterized by measurements of ligand binding to crude membrane fractions and by functional tests on the nociceptive spinal response in a spinal cord-tail preparation in vitro. 2. There were high affinity binding sites for [3H]-[D-Ala2, MePhe4, Gly(ol)5]enkephalin (DAGOL), [3H]-U69593, and [3H]-ethylketocyclazocine (EKC) on spinal cord membranes from neonatal rats. Hill slopes for binding of [3H]-DAGOL and [3H]-U69593 were close to unity. The Hill slope for binding of [3H]-EKC was less than unity, even after its interactions at mu-receptors had been blocked with 100 nM unlabelled DAGOL. Binding sites for [3H]-[D-Pen2, D-Pen5]enkephalin (DPDPE) could not be detected. 3. In competition assays U50488 was as potent as PD117302 and U69593 in competition for either [3H]-U69593 or [3H]-EKC binding sites. Hill slopes for a range of competing ligands at [3H]-DAGOL or [3H]-U69593 sites were close to unity. Hill slopes for competition at [3H]-EKC sites were less than one. 4. In the spinal cord-tail preparation from neonatal rats, opioid receptor agonists depressed spinal nociceptive responses evoked by application of capsaicin or heat to the tail. The order of potency was DAGOL greater than U69593 = PD117302 greater than morphine greater than U50488 = [D-Pen2, L-Pen5]enkephalin (DPLPE). 5. The antagonist naloxone was about equally potent against DAGOL, morphine and DPLPE, and about ten times less potent against U69593 and PD117302. The effects of U50488 were much less sensitive to blockade by naloxone than the effects of PD11703 or U69593. The Kappa antagonist, nor-binaltorphimine was equipotent against all three Kappa agonists. 6. The absence of delta-binding sites, and the low potency and relatively high sensitivity to naloxone suggest that DPLPE could be working at mu-receptors in the neonatal rat spinal cord. 7. The binding assays show that U50488 has the same affinity as PD1 17302 and U69593 for Kappa-receptors, yet it was less effective in the depression of nociceptive responses. This may be because U50488 has a relatively low efficacy at Kappa-receptors. It is possible that at high concentrations U50488 activates receptors not affected by other Kappa-ligands. These additional receptors may be non-opioid receptors (hence the insensitivity to naloxone), or they could be a subtype of Kappa-opioid receptor.

Rights and responsibilities.

As an alternative to rights theory, John Ladd proposes an ethics of responsibility based on interpersonal relationships. These relationships, described as friendships, are personal in nature, founded on trust, and obtain between doctor and patient, parent and child, etc. Ladd presents his views in a most appealing way -- helping the needy, being friends with the doctor. We argue that Ladd's ethics of responsibility is plausible only because he ignores the facts of power which rights theory was designed to take into account, and that rights and the corresponding institutional model of medicine are indeed appropriate to the physician/patient relationship.