Supportive parent-adolescent relationships as a foundation for adolescent emotion regulation and adjustment

Introduction

The purpose of this investigation was to examine the influence of supportive parent-adolescent relationships on adolescent adjustment (i.e., prosocial behavior, aggression, depressive symptoms) both directly and indirectly (via adolescent emotion regulation). Scholars have posited that adolescent emotion regulation (ER) may serve as an underlying mechanism in the link between parenting and adolescent adjustment. Supportive parent-adolescent relationships (i.e., openness, acceptance, emotional responsiveness) may be a key emotion socialization mechanism influencing adolescent ER.

Methods

The sample included 206 adolescents (Age Range= 10-18years; 51% female; 70.4% ethnic minorities) and one primary caregiver (83.3% biological mothers, 38.7% single parents). Structural equation modeling (SEM) was implemented to investigate the direct and indirect (via adolescent ER) effects of supportive parent-adolescent relationships on adolescent adjustment. We also explored whether these indirect and direct effects varied by adolescent sex and age.

Results

Results suggested direct and indirect (via adolescent ER) links between supportive parent-adolescent relationships and adolescent prosocial behavior, aggressive behavior, and depressive symptoms. Moreover, evidence indicated that many of these pathways were significant for boys but not girls. No evidence of youth age as a moderator was found.

Discussion

These findings highlight the important role supportive parent-adolescent relationships play in adolescent emotional and behavioral adjustment. Parenting programs could focus on facilitating a mutually responsive parent-adolescent relationship with a specific focus on the dynamic nature of emotion socialization during adolescence.

Substance use patterns in 9-10 year olds: Baseline findings from the adolescent brain cognitive development (ABCD) study

BACKGROUND

The Adolescent Brain Cognitive Development ™ Study (ABCD Study®) is an open-science, multi-site, prospective, longitudinal study following over 11,800 9- and 10-year-old youth into early adulthood. The ABCD Study aims to prospectively examine the impact of substance use (SU) on neurocognitive and health outcomes. Although SU initiation typically occurs during teen years, relatively little is known about patterns of SU in children younger than 12.

METHODS

This study aims to report the detailed ABCD Study® SU patterns at baseline (n = 11,875) in order to inform the greater scientific community about cohort's early SU. Along with a detailed description of SU, we ran mixed effects regression models to examine the association between early caffeine and alcohol sipping with demographic factors, externalizing symptoms and parental history of alcohol and substance use disorders (AUD/SUD).

PRIMARY RESULTS

At baseline, the majority of youth had used caffeine (67.6 %) and 22.5 % reported sipping alcohol (22.5 %). There was little to no reported use of other drug categories (0.2 % full alcohol drink, 0.7 % used nicotine, <0.1 % used any other drug of abuse). Analyses revealed that total caffeine use and early alcohol sipping were associated with demographic variables (p's<.05), externalizing symptoms (caffeine p = 0002; sipping p = .0003), and parental history of AUD (sipping p = .03).

CONCLUSIONS

ABCD Study participants aged 9-10 years old reported caffeine use and alcohol sipping experimentation, but very rare other SU. Variables linked with early childhood alcohol sipping and caffeine use should be examined as contributing factors in future longitudinal analyses examining escalating trajectories of SU in the ABCD Study cohort.

Extracurricular Activities, Screen Media Activity, and Sleep May Be Modifiable Factors Related to Children's Cognitive Functioning: Evidence From the ABCD Study®

This study used a machine learning framework in conjunction with a large battery of measures from 9,718 school-age children (ages 9-11) from the Adolescent Brain Cognitive DevelopmentSM (ABCD) Study to identify factors associated with fluid cognitive functioning (FCF), or the capacity to learn, solve problems, and adapt to novel situations. The identified algorithm explained 14.74% of the variance in FCF, replicating previously reported socioeconomic and mental health contributors to FCF, and adding novel and potentially modifiable contributors, including extracurricular involvement, screen media activity, and sleep duration. Pragmatic interventions targeting these contributors may enhance cognitive performance and protect against their negative impact on FCF in children.

Correspondence Between Perceived Pubertal Development and Hormone Levels in 9-10 Year-Olds From the Adolescent Brain Cognitive Development Study

Aim

To examine individual variability between perceived physical features and hormones of pubertal maturation in 9-10-year-old children as a function of sociodemographic characteristics.

Methods

Cross-sectional metrics of puberty were utilized from the baseline assessment of the Adolescent Brain Cognitive Development (ABCD) Study-a multi-site sample of 9-10 year-olds (n = 11,875)-and included perceived physical features via the pubertal development scale (PDS) and child salivary hormone levels (dehydroepiandrosterone and testosterone in all, and estradiol in females). Multi-level models examined the relationships among sociodemographic measures, physical features, and hormone levels. A group factor analysis (GFA) was implemented to extract latent variables of pubertal maturation that integrated both measures of perceived physical features and hormone levels.

Results

PDS summary scores indicated more males (70%) than females (31%) were prepubertal. Perceived physical features and hormone levels were significantly associated with child's weight status and income, such that more mature scores were observed among children that were overweight/obese or from households with low-income. Results from the GFA identified two latent factors that described individual differences in pubertal maturation among both females and males, with factor 1 driven by higher hormone levels, and factor 2 driven by perceived physical maturation. The correspondence between latent factor 1 scores (hormones) and latent factor 2 scores (perceived physical maturation) revealed synchronous and asynchronous relationships between hormones and concomitant physical features in this large young adolescent sample.

Conclusions

Sociodemographic measures were associated with both objective hormone and self-report physical measures of pubertal maturation in a large, diverse sample of 9-10 year-olds. The latent variables of pubertal maturation described a complex interplay between perceived physical changes and hormone levels that hallmark sexual maturation, which future studies can examine in relation to trajectories of brain maturation, risk/resilience to substance use, and other mental health outcomes.

Best Practices for Engaging Pregnant and Postpartum Women at Risk of Substance Use in Longitudinal Research Studies: a Qualitative Examination of Participant Preferences

There are significant barriers in engaging pregnant and postpartum women that are considered high-risk (e.g., those experiencing substance use and/or substance use disorders (SUD)) into longitudinal research studies. To improve recruitment and retention of this population in studies spanning from the prenatal period to middle childhood, it is imperative to determine ways to improve key research engagement factors. The current manuscript uses a qualitative approach to determine important factors related to recruiting, enrolling, and retaining high-risk pregnant and postpartum women. The current sample included 41 high-risk women who participated in focus groups or individual interviews. All interviews were analyzed to identify broad themes related to engaging high-risk pregnant and parenting women in a 10-year longitudinal research project. Themes were organized into key engagement factors related to the following: (1) recruitment strategies, (2) enrollment, and (3) retention of high-risk pregnant and parenting women in longitudinal research studies. Results indicated recruitment strategies related to ideal recruitment locations, material, and who should share research study information with high-risk participants. Related to enrollment, key areas disclosed focused on enrollment decision-making, factors that create interest in joining a research project, and barriers to joining a longitudinal research study. With regard to retention, themes focused on supports needed to stay in research, barriers to staying in research, and best ways to stay in contact with high-risk participants. Overall, the current qualitative data provide preliminary data that enhance the understanding of a continuum of factors that impact engagement of high-risk pregnant and postpartum women in longitudinal research with current results indicating the need to prioritize recruitment, enrollment, and retention strategies in order to effectively engage vulnerable populations in research.

Parent engagement in an original and culturally adapted evidence-based parenting program, Legacy for Children™

Legacy for Children™ (Legacy) is an evidence-based program focused on promoting sensitive, responsive parenting for socioeconomically disadvantaged families. Legacy has recently been culturally and linguistically adapted for Spanish-monolingual Latino families and is being piloted in partnership with an early childhood education program. We conducted a mixed methods study to identify barriers and facilitators to engagement, using program monitoring data sources from both participant and group leader perspectives. We conducted qualitative analyses of open-ended data to identify distinct barriers (e.g., employment challenges, health-related challenges and appointments) and facilitators (e.g., other mothers in group, interest in program topics) to engagement that emerged across English and Spanish language curriculum versions; curriculum-specific barriers and facilitators were also documented. We interpret these findings in light of quantitative data on measures of engagement, showing that participants in the Spanish curriculum evidenced comparable levels of parent-group leader relationship quality relative to the English group, and higher levels of parent's group support/connectedness and overall satisfaction. These results offer promising considerations for optimizing families' engagement in parenting programs in the context of early care and education settings.

Prevalence and Family-Related Factors Associated With Suicidal Ideation, Suicide Attempts, and Self-injury in Children Aged 9 to 10 Years

IMPORTANCE

Although suicide is a leading cause of death for children in the United States, and the rate of suicide in childhood has steadily increased, little is known about suicidal ideation and behaviors in children.

OBJECTIVE

To assess the overall prevalence of suicidal ideation, suicide attempts, and nonsuicidal self-injury, as well as family-related factors associated with suicidality and self-injury among preadolescent children.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study using retrospective analysis of the baseline sample from the Adolescent Brain Cognitive Development (ABCD) study. This multicenter investigation used an epidemiologically informed school-based recruitment strategy, with consideration of the demographic composition of the 21 ABCD sites and the United States as a whole. The sample included children aged 9 to 10 years and their caregivers.

MAIN OUTCOMES AND MEASURES

Lifetime suicidal ideation, suicide attempts, and nonsuicidal self-injury as reported by children and their caregivers in a computerized version of the Kiddie Schedule for Affective Disorders and Schizophrenia.

RESULTS

A total of 11 814 children aged 9 to 10 years (47.8% girls; 52.0% white) and their caregivers were included. After poststratification sociodemographic weighting, the approximate prevalence rates were 6.4% (95% CI, 5.7%-7.3%) for lifetime history of passive suicidal ideation; 4.4% (95% CI, 3.9%-5.0%) for nonspecific active suicidal ideation; 2.4% (95% CI, 2.1%-2.7%) for active ideation with method, intent, or plan; 1.3% (95% CI, 1.0%-1.6%) for suicide attempts; and 9.1% (95% CI, 8.1-10.3) for nonsuicidal self-injury. After covarying by sex, family history, internalizing and externalizing problems, and relevant psychosocial variables, high family conflict was significantly associated with suicidal ideation (odds ratio [OR], 1.12; 95% CI, 1.07-1.16) and nonsuicidal self-injury (OR, 1.09; 95% CI, 1.05-1.14), and low parental monitoring was significantly associated with ideation (OR, 0.97; 95% CI, 0.95-0.98), attempts (OR, 0.91; 95% CI, 0.86-0.97), and nonsuicidal self-injury (OR, 0.95; 95% CI, 0.93-0.98); these findings were consistent after internal replication. Most of children's reports of suicidality and self-injury were either unknown or not reported by their caregivers.

CONCLUSIONS AND RELEVANCE

This study demonstrates the association of family factors, including high family conflict and low parental monitoring, with suicidality and self-injury in children. Future research and ongoing prevention and intervention efforts may benefit from the examination of family factors.

Obesogenic Behaviors and Depressive Symptoms' Influence on Cardiometabolic Risk Factors in American Indian Children

BACKGROUND

American Indian (AI) populations suffer disproportionately from cardiovascular disease and depression as compared to other racial/ethnic groups. Behaviors that contribute to obesity are considered obesogenic and include poor diet, low physical activity, and high screen time. This study examined the relationship between depressive symptoms and obesogenic behaviors on cardiometabolic risk factors in AI youth.

METHODS

Participants (n=121) were evaluated for depressive symptoms, obesogenic behaviors, weight, blood pressure, lipids, and glucose levels.

RESULTS

All participants failed to meet guidelines for intake of sugar-sweetened beverages and fruits/vegetables, 74% did not meet physical activity guidelines, and 85% did not meet screen time guidelines. Lower physical activity was associated with higher body fat percentage (b=-4.20 ± 1.82, p=0.022). Elevated depressive symptoms and presence of at-risk cardiometabolic risk factors were found. Higher depressive symptoms were associated with higher blood glucose (random, fasting, and hemoglobin A1c).

CONCLUSIONS

Low physical activity, high screen time, and the presence of depressive symptomology heighten cardiometabolic risk factors in AI children. Associations between depressive symptoms and blood glucose underscore the impact of emotional health on cardiometabolic disease and emphasize need for proper depression assessment in chronic disease prevention efforts.

Obesogenic Behaviors, Self-Efficacy, and Depressive Symptoms in American Indian Children

BACKGROUND

American Indian (AI) children suffer from high rates of obesity, obesity-related disease, obesogenic behaviors, and depressive symptoms.

OBJECTIVE

Study was designed to determine the associations between depressive symptoms and obesogenic behaviors in school-aged AI children in Oklahoma.

METHODS

Study design was cross-sectional. Depressive symptoms, beverage intake, fruit and vegetable intake, meal frequency, physical activity, and screen time were self-reported.

RESULTS

Mean participant age was 10.5 ± 1.6 years (n = 121); 64% were overweight/obese. Depressive symptoms were associated with dieting and screen time.

CONCLUSION

AI chronic disease prevention efforts will benefit by including measures for depression and associations of obesogenic behaviors and depressive symptoms in treatment planning.

Neural responses to maternal praise and criticism: Relationship to depression and anxiety symptoms in high-risk adolescent girls

Background

The parent-child relationship may be an important factor in the development of adolescent depressive and anxious symptoms. In adults, depressive symptoms relate to increased amygdala and attenuated prefrontal activation to maternal criticism. The current pilot study examined how depressive and anxiety symptoms in a high-risk adolescent population relate to neural responses to maternal feedback. Given previous research relating oxytocin to maternal behavior, we conducted exploratory analyses using oxytocin receptor (OXTR) genotype.

Methods

Eighteen females (ages 12–16) listened to maternal praise, neutral, and critical statements during functional magnetic resonance imaging. Participants completed the Mood and Feelings Questionnaire and the Screen for Child Anxiety Related Emotional Disorders. The OXTR single nucleotide polymorphism, rs53576, was genotyped. Linear mixed models were used to identify symptom or allele (GG, AA/AG) by condition (critical, neutral, praise) interaction effects on brain activation.

Results

Greater symptoms related to greater right amygdala activation for criticism and reduced activation to praise. For left amygdala, greater symptoms related to reduced activation to both conditions. Anxiety symptoms related to differences in superior medial PFC activation patterns. Parental OXTR AA/AG allele related to reduced activation to criticism and greater activation to praise within the right amygdala.

Conclusions

Results support a relationship between anxiety and depressive symptoms and prefrontal-amygdala responses to maternal feedback. The lateralization of amygdala findings suggests separate neural targets for interventions reducing reactivity to negative feedback or increasing salience of positive feedback. Exploratory analyses suggest that parents' OXTR genetic profile influences parent-child interactions and related adolescent brain responses.

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Adolescent brain responses to maternal praise and criticism were examined.

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Anxiety related to prefrontal-amygdala response to both criticism and praise.

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Exploratory results support a role for the OXTR gene in parent-child interactions.

Frequency of family meals and 6-11-year-old children's social behaviors

Family meals are regarded as an opportunity to promote healthy child development. In this brief report, we examined the relationship between frequency of family meals and children's social behaviors in 6-11-year-olds. The 2007 U.S. National Survey of Children's Health (NSCH) provided data on the frequency of family meals in a sample of 6-11-year-old children (N = 24,167). The following social behavior indicators were examined: child positive social skills, child problematic social behaviors, child engagement in school, and parental aggravation with the child. Individual logistic regression analyses were calculated in unadjusted and adjusted models. On average, families had 5.3 meals together per week. In adjusted models, more frequent family meals increased the odds of child positive social skills (OR = 1.08, 95% CI [1.02, 1.16]) and child engagement in school (OR = 1.11, 95% CI [1.06, 1.15]), and decreased the likelihood of child problematic social behaviors (OR = 0.92, 95% CI [0.87, 0.98]). There was no association between frequency of family meals and parental aggravation with the child (OR = 0.98, 95% CI [0.93, 1.04]). Findings support the promotion of family meals to benefit children's development of healthy social behaviors.

Mother-Adolescent Conflict: Stability, Change, and Relations with Externalizing and Internalizing Behavior Problems

Stability and change in mother-adolescent conflict reactions (CRs) and the prediction of CRs from adolescents' earlier behavior problems (and vice versa) were examined with 131 mothers and their adolescents (63 boys). Dyads engaged in a 6-minute conflict discussion twice, 2 years apart (M age was 13 at Time 1 (T1). Nonverbal expressive and verbal CRs during the conflict discussion were coded. Mothers, fathers, and teachers reported on adolescents' problem behaviors. There was inter-individual (rank-order) stability for adolescents' CRs whereas mothers' reactions were less stable. Mean levels of mothers' negativity, anger, and positive reactions and adolescents' negativity declined with time. Mothers' CRs predicted and were predicted by adolescents' problem behaviors more often than adolescents' CRs in zero-order correlations. In structural models with the stability of the constructs accounted for, adolescents' externalizing problems at T1 predicted higher maternal anger at T2. Mothers' anger and positive CRs at T1 predicted fewer T2 adolescents' internalizing problems. Stability and change in CRs are discussed.

Assessing callous-unemotional traits in adolescent offenders: validation of the Inventory of Callous-Unemotional Traits

The presence of callous-unemotional (CU) traits designates an important subgroup of antisocial youth. To improve upon existing measures, the Inventory of Callous-Unemotional Traits (ICU) was developed to provide an efficient, reliable, and valid assessment of CU traits in samples of youth. The current study tests the factor structure and correlates of the ICU scale in a sample (n=248) of juvenile offenders (188 boys, 60 girls) between the ages of 12 and 20 (M=15.47, SD=1.37). Confirmatory factor analyses are consistent with the presence of three independent factors (i.e., Uncaring, Callousness, and Unemotional) that relate to a higher-order callous-unemotional dimension. Also, CU traits overall showed associations with aggression, delinquency, and both psychophysiological and self-report indices of emotional reactivity. There were some important differences across the three facets of the ICU in their associations with these key external criteria.

Adolescent development

This chapter identifies the most robust conclusions and ideas about adolescent development and psychological functioning that have emerged since Petersen's 1988 review. We begin with a discussion of topics that have dominated recent research, including adolescent problem behavior, parent-adolescent relations, puberty, the development of the self, and peer relations. We then identify and examine what seem to us to be the most important new directions that have come to the fore in the last decade, including research on diverse populations, contextual influences on development, behavioral genetics, and siblings. We conclude with a series of recommendations for future research on adolescence.

Correspondence among informants on parenting: preschool children, mothers, and observers

The authors examined the correspondence among preschool children's, mothers', and observers' descriptions of parenting in the mother-child relationship along 3 dimensions (structure, warmth-responsiveness, and hostility). Ninety-four children (mean age = 5 years, 3 months) and their mothers, who represent diverse ethnic and socioeconomic groups, participated in the project. Preschool children were interviewed about their mothers' parenting by means of a developmentally sensitive, age-appropriate research tool for assessing the subjective experience of preschool children. Mothers responded to a self-report measure on their own parenting, and observers rated mothers' parenting behavior during a series of interaction tasks designed to elicit the relevant dimensions of parenting. Results indicated significantly greater correspondence between observer and child report of parenting than that between mother and child and mother and observer reports. Explanations for the inconsistencies among informants and implications of this finding are discussed.

Adolescent development

This chapter identifies the most robust conclusions and ideas about adolescent development and psychological functioning that have emerged since Petersen's 1988 review. We begin with a discussion of topics that have dominated recent research, including adolescent problem behavior, parent-adolescent relations, puberty, the development of the self, and peer relations. We then identify and examine what seem to us to be the most important new directions that have come to the fore in the last decade, including research on diverse populations, contextual influences on development, behavioral genetics, and siblings. We conclude with a series of recommendations for future research on adolescence.

Hydration of amino acid side chains: dependence on secondary structure

Energy calculations have been used to study the hydration sites around the polar groups of serine, threonine and tyrosine side chains. These hydration sites depend not only on the hybridization of the polar group but also on the local secondary structure, the chi 1 side chain torsion angle and the position of the hydroxyl hydrogen atom. For tyrosine side chains, two solvent sites are found approximately in the plane of the ring. Even for serine and threonine side chains only two minimum energy sites are found in general of which one is in an expected position within hydrogen bonding of the hydroxyl hydrogen atom (unless this is blocked from interaction with solvent molecules by, for example, Oi-4 or Oi-3. The position of the second of these sites depends not only on the position of the hydroxyl oxygen but also on neighbouring main chain atoms to which it can also hydrogen bond. There is good agreement with the solvent distributions obtained from crystallographic data.

Mitral valve repair for bacterial endocarditis

Twenty-two patients with mitral insufficiency resulting from native valve endocarditis underwent mitral valve repair. Six patients had acute endocarditis with positive blood cultures and active valve infection. Sixteen patients were cured of active infection, but mitral insufficiency developed as a result of prior infection. Mean age was 48.5 +/- 21.7 years; 13 (59%) were male. Mean New York Heart Association functional class was 2.6 +/- 1.2. Multiple valve lesions were present in 11 (50%) patients. Valve abnormalities included leaflet perforation in 13 patients, chordal rupture or elongation in 14, vegetations in 5; and annular abscess in 1. In patients with acute endocarditis all macroscopically infected tissue was excised. Multiple techniques were required to achieve valve competence. Suture or patch closure of perforation was done in 14 patients, chordal shortening or transfer in 9, leaflet resection and closure in 4, leaflet resection with pericardial patching in 5, and annuloplasty in 15. Mitral valvuloplasty was combined with other procedures in 11 (50%) patients. There were two (9%) hospital deaths, both occurring in patients with healed endocarditis. There was one (9%) death in a patient undergoing an isolated procedure and one (9%) in a patient undergoing a combined procedure. Mean follow-up was 24 +/- 16.8 months and was complete. Seventeen (85%) were in New York Heart Association functional class I, and three (15%) were in class II. There were no late deaths, reoperations, recurrent endocarditis, thromboembolic events, or other valve-related morbidity. We conclude that mitral valve repair for insufficiency resulting from bacterial endocarditis (1) is possible in acute and healed disease, (2) has a low operative mortality, and (3) has resulted in patients free of recurrent infection and valve-related morbidity and mortality. Mitral valve repair is an attractive alternate to valve replacement in bacterial endocarditis.

Glucose uptake and flux through phosphofructokinase in wounded rat skeletal muscle

Skeletal muscle injured with lambda-carrageenan has increased aerobic glycolysis. To assess the regulation of this process, the tissue concentrations of glycolytic intermediates, the flux through phosphofructokinase (PFK), and the intracellular concentrations of PFK effectors were examined in wounded rat skeletal muscle and in macrophages, the predominant inflammatory cell in the early stages of this wound model. Autoradiography demonstrated increased 2-deoxy-D-glucose uptake in wounded tissue compared with nonwounded muscle. 2-Deoxy-D-glucose was localized to the cellular infiltrate. The glycolytic intermediate concentrations demonstrated a facilitation of PFK in macrophages and wounded tissue as compared with nonwounded muscle. Wounded tissue had twice the flux through PFK compared with nonwounded muscle (10.0 +/- 0.6 wounded vs. 4.9 +/- 0.4 mumol.h-1.g-1 nonwounded). Macrophages had the highest flux through PFK (63.7 +/- 5.7 mumol.h-1.g-1) and when coincubated with muscle, the combined flux through PFK was equal to that of wounded muscle. The increase in glycolysis associated with wounded tissue may be explained by increased glucose uptake and increased flux through PFK by the inflammatory cells present in wounded tissue.

The relationship of purine metabolism to the macrophage-mediated increase of high energy phosphates in skeletal muscle

Previous investigations have demonstrated that the high energy phosphate and adenine nucleotide content of wounded tissue are decreased. Purine metabolism was investigated in incubated lambda-carrageenan wounded skeletal muscle and in muscle exposed to peritoneal macrophages or macrophage-conditioned media. Wounded muscle released predominately uric acid into the incubation medium; whereas, nonwounded muscle released inosine, hypoxanthine, and xanthine as well as uric acid. Macrophages incubated with nonwounded muscle changed the purine release pattern toward one of wounded muscle. The conversion of inosine to allantoin and uric acid by macrophages increased linearly with the addition of up to 1 X 10(7) macrophages per incubation. Muscles incubated in macrophage-conditioned media had a decreased release of inosine and hypoxanthine and higher tissue levels of creatine phosphate, ATP, ADP, AMP, and adenosine compared to muscles incubated in standard media. These data suggest that the macrophage determines the pattern of purine release from wounded skeletal muscle in the incubated system and that in conditioned media a high energy phosphate promoting factor may exert its effect by mechanisms that augment the adenine purine pool.

A macrophage-mediated factor that increases the high energy phosphate content of skeletal muscle

A marked cellular infiltrate accompanies wounding. The phagocytic and bacteriocidal activities of this infiltrate require increased substrate and O2 consumption. This rapid utilization of available oxygen and substrates could jeopardize an already compromised resident cellular component of a wound. Recent studies have demonstrated macrophage-mediated cell stimulatory agents which induce proliferation of nonlymphoid mesenchymal cells. This study was designed to examine macrophage-resident tissue interactions and their possible significance in wounded tissue. A reconstituted wound system was designed which combines the major components of a lambda-carrageenan skeletal muscle wound (muscle + macrophages). The extensor digitorum longi (EDL) of male Fisher rats were incubated in a standardized fashion. The groups of EDL were muscle incubated alone, muscle with the addition to the incubate of activated peritoneal macrophages or muscle with the addition of a conditioned supernatant from the incubation of activated or nonactivated peritoneal macrophages. Muscle ATP and CP content were noted to be increased 46 and 22%, respectively, when macrophages and skeletal muscle were coincubated. Macrophage-conditioned media from activated or nonactivated macrophages increased the ATP and CP muscle content 44 and 37%, respectively. Preliminary characterization of this high energy phosphate (HEP) promoting factor demonstrates it to be heat and cold stable and less than 10,000 Da. Therefore, a macrophage-mediated transferable factor is capable of increasing the HEP content of skeletal muscle in an in vitro system. This may have important consequences in maintaining host cell integrity following injury.

Abnormal insulin response in patients with small-vessel disease

The insulin response to a glucose load has been investigated in twenty-five patients with small-vessel disease (ischaemic lesions of toes or feet in the presence of foot pulses). The clinical presentation was similar to that of juvenile diabetic microangiopathy, but in small-vessel disease there was no glucose intolerance. Unexpectedly in the patients with small-vessel disease there was no striking insulin secretion response to the stimulus of a glucose load. Controls increased their circulating insulin levels on average sixfold over fasting levels after 50 g. oral glucose: all the small-vessel-disease patients had increases of less than three times their fasting levels, and nine of them had completely flat curves throughout the test. Tolbutamide also did not stimulate insulin secretion. The refractory state of these patients' responses to the normal stimulus of insulin output has similarities to the picture in juvenile diabetes mellitus and may be important in the aetiology of the small-vessel lesions.

Insulin response to glucose in patients with peripheral vascular disease, arteritis, and Raynaud's phenomenon

Twenty-three patients with peripheral vascular disease due to atheromatous blocks in large vessels, four patients with arteritis, and twenty patients with Raynaud's phenomenon were tested for insulin response to glucose. (In an earlier investigation patients with small-vessel peripheral vascular disease did not secrete insulin in response to a glucose load--a previously unreported finding.) Insulin output after glucose in patients with atheromatous blocks in large peripheral arteries fell into three categories: (1) normal glucose tolerance and insulin output, the insulin rise (peak/basal ratio) comparing well with the rise in controls; (2) carbohydrate intolerance with a prediabetic pattern of glucose-tolerance test, and raised circulating insulin levels both fasting insulin and after glucose, so that the insulin rise was lower than normal; or (3) the flat insulin responses after glucose that had been noted in small-vessel disease with normal glucose tolerance. Thus in these twenty-three patients with large-vessel blocks presenting with peripheral vascular disease the high and late insulin secretion after glucose reported by other workers for patients with atheroma could not be confirmed. High but not delayed insulin peaks were seen after a glucose stimulus in some patients with arteritis and with Raynaud's phenomenon.