Dampened psychobiological responses to stress and substance use in adolescence

Substance use increases throughout adolescence, and earlier substance use may increase risk for poorer health. However, limited research has examined whether stress responses relate to adolescent substance use, especially among adolescents from ethnic minority and high-adversity backgrounds. The present study assessed whether blunted emotional and cortisol responses to stress at age 14 related to substance use by ages 14 and 16, and whether associations varied by poverty status and sex. A sample of 277 Mexican-origin youth (53.19% female; 68.35% below the poverty line) completed a social-evaluative stress task, which was culturally adapted for this population, and provided saliva samples and rated their anger, sadness, and happiness throughout the task. They also reported whether they had ever used alcohol, marijuana, cigarettes, and vaping of nicotine at age 14 and again at age 16. Multilevel models suggested that blunted cortisol reactivity to stress was associated with alcohol use by age 14 and vaping nicotine by age 16 among youth above the poverty line. Also, blunted sadness and happiness reactivity to stress was associated with use of marijuana and alcohol among female adolescents. Blunted stress responses may be a risk factor for substance use among youth above the poverty line and female adolescents.

Dampened autonomic nervous system responses to stress and substance use in adolescence

We investigated whether parasympathetic and sympathetic nervous system (SNS) responses to social-evaluative threat at age 14 were related to the number of substances used between ages 14 and 16 among Mexican-origin adolescents (N = 243; 70.4% had never used substances by 14). Participants completed the Trier Social Stress Test, while cardiac measures of parasympathetic and SNS activity were measured continuously using respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), respectively. Participants reported whether they had ever used alcohol, marijuana, and cigarettes, and had ever vaped nicotine in their lifetime at ages 14 and 16. Multilevel models were used to test associations between RSA and PEP responses at age 14 and substance use at 16. Among youth who had not used substances by 14, dampened RSA and PEP responses, and profiles of greater coinhibition and lower reciprocal SNS activation between RSA and PEP, at age 14 were associated with using substances by 16. Among youth who used by 14, exaggerated PEP responses were associated with using more substances by age 16. Taken together, dampened autonomic responses to social-evaluative threat predicted initiation of substance use over two years, and difficulties with coordination of physiological responses may confer risk for substance use in adolescence.

A 28-day, 2-year study reveals that adolescents are more fatigued and distressed on days with greater NO2 and CO air pollution

This 2-year, 28-day study examined whether adolescents felt greater fatigue and emotional distress the same day and the day after air quality was worse. We linked objective daily air quality measurements to daily self-reports from 422 Mexican-American adolescents in Los Angeles County, California from 2009 to 2011 (50% girls, M_Age = 15 years). A robust, within-subject analysis of 9696 observations revealed that adolescents with ongoing physical complaints reported greater fatigue and emotional distress on days that the air contained higher levels of nitrogen dioxide (NO₂) and carbon monoxide (CO). Regardless of physical complaints, adolescents on average also reported greater fatigue the day after NO₂ levels were higher. The same-day and next-day associations between air pollution and distress were mediated via daily increases in fatigue. Results were robust when controlling for day of the week, and daily temperature and humidity. Sulfur dioxide (SO₂), ozone (O₃), PM_2.5 and PM₁₀ were not related to daily fatigue or distress.

Earlier age of sex and substance use initiation is associated with unique hormone profiles during social evaluative threat in Mexican American adolescents

Latinx adolescents are at a disproportional risk for poor sexual and reproductive health outcomes (STIs, adolescent pregnancy) compared to other ethnic groups. They also report high rates of alcohol and drug use that are similar to non-Hispanic White youth. The hormonal underpinnings of the emergence of sex and substance use behaviors among Latinx adolescents remain understudied however. Pubertal shifts in motivation and reward-seeking in social situations are closely tied to the emergence of risky sexual and substance use behaviors. The experience of developing earlier or later than same age peers may increase stress (cortisol) reactivity during social evaluative situations leading to more risky behavior. Further, testosterone can be responsive to social evaluative threat (SET) and is linked to status-seeking behavior, including risk-taking. The current study sought to unravel the complex relationship between cortisol and testosterone responsivity to social evaluative threat, pubertal status, and the emergence of sex and drug use among US-born Mexican-origin youth growing up in an agricultural community. Mexican American 14-year olds (N = 234, 54% female) from the Center for Health Assessment of Mothers and Children (CHAMACOS) participated in the Trier Social Stress Test. Cortisol and testosterone were assayed from saliva. At 16, youth reported on age at vaginal and oral sex initiation, and alcohol and marijuana use initiation. Hierarchical regressions examined cortisol and testosterone reactivity, and pubertal status within each sex to predict the onset of these risky behaviors. Results indicated that boys who were less developed than their same-aged peers or with lower testosterone reactivity and elevated cortisol reactivity to the TSST reported the earliest sex and substance use initiation. For girls, higher cortisol reactivity predicted earlier alcohol use initiation, and higher testosterone reactivity predicted earlier oral sex. Our results suggests it is important for health care providers to not overlook Latinx boys who may look younger in discussions about mitigating risk. Latinx girls under increased stress may be more likely to try to self-medicate with alcohol, and potentially other drugs.

Infections due to Cellulosimicrobium species: case report and literature review

Background

Cellulosimicrobium species, formely known as Oerskovia species, are gram-positive bacilli belonging to the order Actinomycetales. They rarely cause human infections. The genus comprises two pathogenic species in humans: C. cellulans and C. funkei. Based on a case report, we provide a review of the literature of infections caused by Cellulosimicrobium/Oerskovia, in order to improve our knowledge of this unusual infection.

Case presentation

An 82-year-old woman with aortic prosthetic valve presented to the hospital with fever and heart failure. Further work up revealed the diagnosis of C. cellulans infective endocarditis (IE). The strain was identified by MALDI-TOF MS, API Coryne and 16S rRNA sequencing. The patient was deemed not to be an operative candidate and died despite the antibiotic therapy 35 days after admission.

Conclusions

Reviewing cases of Cellulosimicrobium species infections and communicating the successful and unsuccessful clinical experiences can assist future healthcare providers. Our case and those previously reported indicate that Cellulosimicrobium species usually infect immunocompromised patients or foreign body carriers. The most frequent pattern of infection is central venous catheter related bacteremia. The optimal treatment should include foreign body removal and valve surgery should be considered in case of IE.

Family First? The Costs and Benefits of Family Centrality for Adolescents with High-Conflict Families

Youth who do not identify with or value their families (i.e., low family centrality) are considered to be at risk for maladjustment. However, the current study investigated whether low family centrality may be adaptive in negative family contexts (i.e., high family conflict) because youth's self-worth should be less tied to the quality of their family relationships. Multilevel models using daily diaries and latent variable interactions using longitudinal questionnaires indicated that, among a sample of 428 Mexican American adolescents (49.8% male, M _age = 15.02 years), lower family centrality was generally detrimental to youth's well-being. However, for youth in adverse family environments, low family centrality ceased to function as a risk factor. The present findings suggest that family centrality values play a more nuanced role in youth well-being than previously believed, such that low family centrality may be an adaptive response to significant family challenges.

Cultural Contributors to Smoking Susceptibility Outcomes Among Latino Youth: The Padres Informados/Jovenes Preparados Participatory Trial

Padres Informados/Jovenes Preparados is a community-based participatory, family-focused tobacco prevention intervention for immigrant Latino families of adolescents. We conducted a participatory randomized controlled trial including 352 Latino families. Parents and youth in the intervention condition engaged in eight family skill building sessions. Participants completed baseline and 6-month postintervention surveys assessing smoking susceptibility and contextual factors. While the intervention did not affect smoking susceptibility overall, it resulted in lower smoking susceptibility among youth in families with less adherence to traditional Latino cultural values. This family cultural orientation is a key consideration for tobacco prevention interventions focused on Latino youth.

Adolescent Temperament Moderates the Relation of Parenting to Antisocial Behavior and Substance Use

Although some studies have found that parental support and control are related negatively to adolescent problem behaviors, little research has examined factors that may qualify the magnitude of those relations. The present study tests whether adolescent temperament moderates the relations of parenting to antisocial behavior and substance use within a community sample (N = 631). The joint and unique contributions of parenting and temperament in the prediction of those problem behaviors were also examined in this study. Results indicate that parenting and temperament evidenced significant joint and unique relations with adolescent antisocial behavior and substance use. Furthermore, temperament moderated the relations between parenting and adolescent problem behaviors, wherein parenting showed stronger relations with antisocial behavior and substance use at higher levels of temperamental risk. The findings supported the contention that individual differences moderate the relations between parenting and problem behaviors and indicate several directions forfuture research.

Filling Gaps in the Acculturation Gap-Distress Model: Heritage Cultural Maintenance and Adjustment in Mexican-American Families

The acculturation gap-distress model purports that immigrant children acculturate faster than do their parents, resulting in an acculturation gap that leads to family and youth maladjustment. However, empirical support for the acculturation gap-distress model has been inconclusive. In the current study, 428 Mexican-American adolescents (50.2 % female) and their primary caregivers independently completed questionnaires assessing their levels of American and Mexican cultural orientation, family functioning, and youth adjustment. Contrary to the acculturation gap-distress model, acculturation gaps were not associated with poorer family or youth functioning. Rather, adolescents with higher levels of Mexican cultural orientations showed positive outcomes, regardless of their parents' orientations to either American or Mexican cultures. Findings suggest that youths' heritage cultural maintenance may be most important for their adjustment.

Mexican American adolescents' family obligation values and behaviors: links to internalizing symptoms across time and context

Family obligation is an important aspect of family relationships among families from Mexican backgrounds and can have significant implications for adolescents' well-being. Prior research and theory regarding youths' obligations offer conflicting hypotheses about whether it is detrimental or beneficial for adolescents' well-being. In the current longitudinal study, we used a daily diary method among 428 Mexican American adolescents and their parents to closely examine the impact of adolescents' family obligation values and family assistance behaviors on internalizing symptoms over time. The authors closely examined the role of the family context in these associations. Results suggest that family obligation values relate to declines in adolescents' internalizing symptoms, whereas family assistance behaviors are both a protective and risk factor, depending on the family context. Only when youths provide family assistance in response to acute changes in parental physical and psychological distress do family assistance behaviors relate to increases in adolescents' internalizing symptoms.

THE COMBINED USE OF HONEY, GARLIC (ALLIUM SATIVUM L.) AND SKIMMED MILK AS AN EXTENDER FOR CHILLING SHEEP SEMEN

BACKGROUND

Sugars are the energetic source for sperm to maintain the metabolic process, and the antibiotics slow down sperm degradation.

OBJECTIVE

To study the effects of rosemary honey as energy source and cryoprotectant in combination with garlic as a natural antibiotic on the quality of ram spermatozoa upon cooling.

MATERIALS AND METHODS

The ejaculates from three rams were evaluated at different times during cooling to determine its post-dilution quality.

RESULTS

Glycerol and dimethylformamide in conjunction with honey and garlic significantly improve the survival of spermatozoa.

CONCLUSION

The addition of honey and garlic reduces sperm deterioration when stored at 4 degree C.

Family obligation values and family assistance behaviors: protective and risk factors for Mexican-American adolescents' substance use

Adolescent substance use is one of today's most important social concerns, with Latino youth exhibiting the highest overall rates of substance use. Recognizing the particular importance of family connection and support for families from Mexican backgrounds, the current study seeks to examine how family obligation values and family assistance behaviors may be a source of protection or risk for substance use among Mexican-American adolescents. Three hundred and eighty-five adolescents (51% female) from Mexican backgrounds completed a questionnaire and daily diary for 14 consecutive days. Results suggest that family obligation values are protective, relating to lower substance use, due, in part, to the links with less association with deviant peers and increased adolescent disclosure. In contrast, family assistance behaviors are a source of risk within high parent-child conflict homes, relating to higher levels of substance use. These findings suggest that cultural values are protective against substance use, but the translation of these values into behaviors can be a risk factor depending upon the relational context of the family.

Oral health assessment in the San Blas and Santa Ana populations of Nicaragua

AIM

The aim of this study was to assess the oral health of a population in rural Nicaragua.

METHODS

A total of 241 individuals were recruited from areas around San Blas and Santa Ana, Nicaragua. A demographic questionnaire assessing income, access to oral health care, means of transportation and presence of dental/health insurance was collected for each patient. Oral screenings were also conducted to assess for evidence of untreated decayed teeth, restorations, missing/extracted teeth and presence/absence of periodontal disease.

RESULTS

The majority of residents in San Blas and Santa Ana, Nicaragua, have little income if any, no medical or dental insurance of any kind and no means of transportation. There was a very high prevalence of untreated decayed teeth among the population studied where 51.1% of our sample had three or more dental caries. Children aged fewer than 20 years had five times the prevalence of dental decay than those in the United States. No statistically significant difference was found in untreated decayed teeth by age or gender. A smaller percentage (25.2%) of all patients had restorations with a statistically significant difference found between genders (P < 0.0001). There was also a relationship between gender and number of missing/extracted teeth (P < 0.001). There was no significant difference in amount of untreated decayed teeth among those who reported having been seen by a dentist within the previous one-to-three, greater than 3 years or never at all.

CONCLUSION

Among a population of individuals from San Blas and Santa Ana, Nicaragua, there are major socio-economic barriers present, and a significant burden of oral pathology is evident.

Effect of pasteurized egg and Rosmarinus officinalis supplementation on quality of cryopreserved ram semen

The aim was to assess the in vitro effect of pasteurized egg (PE) and rosemary (Rosmarinus officinalis) on frozen-thawed ram semen. Ejaculates from three mature rams of the Rasa Aragonesa breed were cryopreserved using a 2-step dilution method (Fraction 1: F1; Fraction 2: F2). In Experiment 1, semen was frozen in egg yolk (EY) or PE extenders. After thawing, similar results were obtained in terms of total and progressive motility, viability, hypo-osmotic swelling test (HOST) and acrosome integrity after 2 h incubation. In Experiment 2, addition of rosemary to F1, F2 or both fractions to EY extenders was evaluated. Rosemary in F1 decreased progressive motility (p = 0.013) after 2 h incubation. Finally, PE can be used as a substitute for EY to reduce hygienic risks in extenders and is easier to standardize. Supplementation of EY extender with rosemary in F1 reduced progressive motility. Rosemary supplementation in F2 does not affect semen quality.

Family and neighborhood fit or misfit and the adaptation of Mexican Americans

In this study, a person-environment fit model was used to understand the independent and combined roles of family and neighborhood characteristics on the adjustment of adults and children in a sample of 750 Mexican American families. Latent class analysis was used to identify six qualitatively distinct family types and three quantitatively distinct neighborhood types using socioeconomic and cultural indicators at each level. The results showed that members of single-parent Mexican American families may be particularly at-risk, members of the lowest-income immigrant families reported fewer adaptation problems if they lived in low-income neighborhoods dominated by immigrants, members of economically successful immigrant families may be more at-risk in integrated middle class neighborhoods than in low-income neighborhoods dominated by immigrants, and members of two-parent immigrant families appear to be rather resilient in most settings despite their low socioeconomic status.

The New Beginnings Program for Divorcing and Separating Families: Moving from Efficacy to Effectiveness

This article describes a program of research on effectively transporting the New Beginnings Program (NBP), a university-tested prevention program for divorced families, to community settings. The status of four steps in this research are described: (1) Selecting a community partner; (2) Developing effective methods of engaging parents; (3) Redesigning the NBP to be easily delivered with high quality and fidelity in community agencies, and (4) Adapting the NBP to meet the needs of the full population of divorcing families. The article concludes with a discussion of plans for an effectiveness trial to evaluate the NBP when delivered in community settings.

[Local investigation concerning psychic and sexual functioning a short time after hysterectomy]

Hysterectomy is one of the most common operations done throughout the world. Patients' concerns about sexual functioning after hysterectomy is great.

OBJECTIVE

We wanted to evaluate, through a local investigation based on a questionnaire, the psychosexual impact of this operation and to compare our data to those available in the literature.

PATIENTS AND METHODS

534 patients operated between of 01.01.1997 and 31.12.1997 for a benign uterine pathology (prolapse excluded) were included. Questions were about sexual and psychological functioning after hysterectomy. The main outcome measures were changes in the sexual life, sexual desire, orgasm, dyspareunia, frequency of sexual relations. Abdominal and vaginal surgical approaches were compared for some items when possible.

RESULTS

After the operation, 83.3% of the patients felt better, 30.4% of the patients mentioned changes in their sexual life, 32% of low libido rates was noticed (and there was a significant difference between abdominal and vaginal surgical approaches), 27.6% of the patients had less frequent orgasm and only 8.8% experienced orgasm more frequently, 15% suffer from dyspareunia, and 15% were more engaged in sexual intercourse.

CONCLUSION

Psychosexual impact of hysterectomy is limited and is not more frequent when vaginal surgery is performed, but pre- and post-operative prevention can be useful.

Chronic donepezil treatment is associated with slowed cognitive decline in Alzheimer's disease

OBJECTIVE

To compare rates of cognitive decline between probable Alzheimer's disease (AD) patients treated with long-duration cholinesterase inhibitors (ChE-Is) and those who remained untreated.

BACKGROUND

ChE-Is, including donepezil and tracrine, have shown beneficial effects on cognition and global functioning in patients with AD. The duration of these benefits is unknown because the longest double-blind placebo-controlled studies reported were only approximately 6 months long. Ethical concerns regarding randomization of patients to placebo for long periods make it difficult to undertake trials of longer duration.

METHODS

We identified patients in 4 AD centers who were or were not consistently treated with ChE-Is and who had demographic, psychometric and follow-up data. We compared 205 ChE-I-treated and 218 untreated AD patients on baseline variables hypothesized to differ between these groups, on baseline Mini Mental Status Examination (MMSE) scores and on rates of MMSE change at 1 year. The analysis was performed initially with all ChE-I-treated patients as a single group versus untreated subjects, and then with donepezil versus untreated subjects and tacrine versus untreated subjects.

RESULTS

As expected, treated and untreated patients differed with respect to age, education, ethnicity, percentage of community dwelling and exact days of follow-up (ANOVA and chi2) in several comparisons, but did not differ on baseline MMSE score. These baseline variables were highly intercorrelated. MMSE scores declined significantly more slowly after 1 year of ChE-I treatment compared to untreated patients (p = 0.05) after controlling for baseline differences in age, education, ethnicity and percentage of community dwelling. Slowing of decline was significant in the donepezil-treated patients (p = 0.007) but not in the tacrine-treated group (p = 0.33).

CONCLUSIONS

This study, utilizing concurrent, nonrandomized controls, suggests that donepezil continues to have efficacy over at least the first year of therapy. Other studies are needed to determine whether the benefits are maintained beyond 1 year.

The DRD4 gene and the spiritual transcendence scale of the character temperament index

Two hundred male subjects (81 college students and 119 subjects from an addiction treatment unit) were administered the Temperament and Character Inventory (TCI) and genotyped at the 48 base pair repeat polymorphism of the DRD4 gene. Subjects were divided by genotype into those carrying any < 4 repeat allele, those homozygous for the 4 repeat allele, and those with any > 4 repeat allele. The total MANCOVA of seven TCI summary scores, with age and diagnostic group as covariates, was significant (P < or = 0.001). The largest effect was with self-transcendence (P < or = 0.001). The total MANCOVA for the three self-transcendence subscores was significant (P < or = 0.017), with the spiritual acceptance subscore showing the most effect (P < or = 0.001, power = 0.91). These results suggest the DRD4 gene may play a role in the personality trait of spiritual acceptance. This may be a function of the high concentration of the dopamine D4 receptor in the cortical areas, especially the frontal cortex.

Evidence that pioglitazone, metformin and pentoxifylline are inhibitors of glycation

Enhanced formation and accumulation of advanced glycation end products (AGEs) have been proposed to play a major role in the pathogenesis of diabetic complications, and atherosclerosis, leading to the development of a range of diabetic complications including nephropathy, retinopathy and neuropathy. Several potential drug candidates as AGE inhibitors have been reported recently. Aminoguanidine is the first drug extensively studied. However, there are no currently available medications known to block AGE formation. We have previously reported a number of novel and structurally diverse compounds as potent inhibitors of glycation and AGE formation. We have now studied several of the existing drugs, which are in therapeutic practice for lowering blood sugar or the treatment of peripheral vascular disease in diabetic patients, for possible inhibitory effects on glycation. We show that that three compounds; pioglitazone, metformin and pentoxifylline are also inhibitors of glycation.

Evidence that 12-lipoxygenase product 12-hydroxyeicosatetraenoic acid activates p21-activated kinase

The effect of 12-hydroxyeicosatetraenoic acid (12-HETE), an arachidonic acid metabolite of 12-lipoxygenase, to activate p21(Rac/Cdc42)-activated kinase (PAK1) was studied in a Chinese hamster ovary fibroblast cell line overexpressing the rat vascular type-1a angiotensin II receptor (CHO-AT(1a)). 12-HETE (0.1 microM) treatment induced a time-dependent activation of PAK1, with a peak effect at 10 min (335 +/- 16% of control; n=3, P<0.001). The stimulatory effect of 12-HETE on PAK1 activity was dose-dependent, with the maximal activation at 0.01 microM (350+/-15% of control; n=3, P<0.001). A PAK1 fragment encoding the Cdc42/Rac binding domain (amino acid residues 67-150 of hPAK1 termed PBD), was transfected into CHO-AT(1a) cells. PBD transfection markedly reduced 12-HETE-induced PAK1 activation. Furthermore, transfection of dominant negative Cdc42 and Rac1 inhibited 12-HETE-induced PAK1, strongly suggesting that Cdc42 and Rac1 are the upstream activators of 12-HETE-induced PAK1 activation. Low concentrations (1.5 microM) of LY294002, a highly specific inhibitor of phosphoinositide 3-kinase (PI-3K), abolished 12-HETE-induced PAK1 activation, suggesting that PI-3K activation is upstream of 12-HETE-induced PAK1 activation. Transfection of dominant negative PAK1 blocked 12-HETE-induced PAK1, cJun N-terminal kinase (JNK1) and extracellular-signal-regulated kinase (ERK) activity, while transfection of constitutively active PAK1 stimulated PAK1, JNK1 and ERK activity, suggesting that PAK1 is an upstream activator of 12-HETE-induced JNK1 and ERK activation in these cells. We conclude that 12-HETE can activate Cdc42, Rac1 and PI-3K, which then participate as upstream signalling molecules for PAK1 and JNK1 activation.

Novel inhibitors of advanced glycation endproducts (part II)

Enhanced formation and accumulation of advanced glycation endproducts (AGEs), have been implicated as a major pathogenesis process leading to diabetic complications, normal aging, atherosclerosis, and Alzheimer's Disease. Several potential drug candidates as AGE inhibitors have been reported recently. The aim of this study was to develop classes of novel inhibitors of glycation, AGE formation, and AGE-crosslinking and to investigate their effects through in vitro chemical and immunochemical assays. A total of 92 compounds were designed and synthesized. The first 63 compounds were reported before. Nearly half of the 29 novel inhibitors reported here are benzoic acid derivatives and related molecules, and found to be potent inhibitors of multistage glycation, AGE formation, and AGE-protein crosslinking. All 29 compounds show some degrees of inhibitory activities as detected by the four assay methods, 9 compounds demonstrated high percent inhibition (PI) in all tests, 30 to 40 times stronger than aminoguanidine.

Novel inhibitors of advanced glycation endproducts

Enhanced formation and accumulation of advanced glycation endproducts (AGE's) have been proposed to play a major role in the pathogenesis of diabetic complications, aging, atherosclerosis, and Alzheimer disease leading to progressive and irreversible intermolecular protein crosslinkings. This process is accelerated in diabetes and has been postulated to contribute to the development of a range of diabetic complications including nephropathy, retinopathy and neuropathy. Several potential drug candidates as AGE inhibitors have been reported recently. Aminoguanidine is the first drug extensively studied both in vitro and in vivo. We have developed a new class of compounds as potent inhibitors of glycation and AGE formation. The novel inhibitors reported here are aryl (and heterocyclic) ureido, and aryl (and heterocyclic) carboxamido phenoxy isobutyric acids and related molecules, which were found by in vitro assay methods to be potent inhibitors of multiple stage of glycation and AGE formation.

Effects of high glucose on vascular endothelial growth factor expression in vascular smooth muscle cells

Vascular endothelial growth factor (VEGF), in addition oto its growth-promoting effects on endothelial cells, can also increase vascular permeability and monocyte migration. It has therefore been implicated in the pathogenic neovascularization associated with diabetic retinopathy and atherosclerosis. However, the factors regulating VEGF expression in the vascular wall are not fully understood. In this study, we examined the regulation of VEGF expression in vascular smooth muscle cells (VSMC) by hyperglycemia as well as by angiotensin II (ANG II). We also examined whether the 12-lipoxygenase (12-LO) product 12-hydroxyeicosatetraenoic acid (12-HETE) can alter VEGF expression, since 12-LO products of arachidonic acid have angiogenic properties, and ANG II as well as high glucose (HG, 25 mM) can increase 12-LO activity and expression in VSMC. Studies were carried out in human (HSMC) or porcine VSMC (PSMC), which were cultured for at least two passages under normal glucose (NG, 5.5 mM) or HG conditions. HG culture alone increased the expression of VEGF mRNA and protein in both HSMC and PSMC. Furthermore, ANG II treatment significantly induced VEGF mRNA and protein expression only in VSMC cultured in HG and not NG. In addition, 12-HETE significantly increased VEGF mRNA and protein expression in HSMC cultured in NG as well as in HG. Cells cultured in HG also secreted significantly greater amounts of VEGF into the culture medium. These results suggest that elevated VEGF production under HG conditions may play a role in the accelerated vascular disease observed in diabetes.

Evidence that angiotensin II and lipoxygenase products activate c-Jun NH2-terminal kinase

The effect of angiotensin II (Ang II) to activate c-Jun amino-terminal kinase (JNK) was studied in a Chinese hamster ovary fibroblast cell line overexpressing the rat vascular type-1a Ang II receptor (CHO-AT1a). Ang II treatment induced a time-dependent activation of JNK. Ang II (10(-7) mol/L) activated JNK activity, with a peak at 30 minutes (9.39 +/- 2.52-fold, n = 7, P < .02 versus control), which was maintained until 3 hours (2.7 +/- 0.65-fold, n = 3, P < .02 versus control). Ang II-induced JNK activation at 30 minutes was inhibited by a specific lipoxygenase (LO) pathway inhibitor, cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate (1 mumol/L) by 87.5% (n = 4, P < .01 versus Ang II-induced JNK activity). The direct addition of 12-HETE also induced a time-dependent JNK activation. 12-HETE (10(-7) mol/L) activated JNK activity, with a peak at 10 minutes (3.43 +/- 0.87-fold, n = 6, P < .02 versus control), which remained elevated until 1 hour. These results suggest that the LO pathway is a mediator of Ang II-induced JNK activation. 15-HETE can also activate JNK at 5 minutes, but this activity was reduced at 30 minutes and could not be seen at 1 hour, indicating that the time course was different from that seen with 12-HETE. N-Acetylcysteine (NAC), an antioxidant, was used to perturb intracellular reactive oxygen intermediate (ROI) levels to assess the role of endogenous ROIs in regulating JNK activity. Pretreatment of cells with 500 mumol/L NAC for 1 hour attenuated approximately 50% of Aug II-induced JNK activation, suggesting that ROIs, at least partially, mediate Ang II-induced JNK activation. Furthermore, 12-HETE-induced JNK activation was reduced by approximately 90% by NAC. Finally, pertussis toxin completely blocked 12-HETE-induced JNK activation, suggesting that Gi-protein signaling participates in 12-HETE-induced effects. These results suggest that LO activation plays a role in mediating Ang II-induced JNK activation in part by altering the redox tone and Gi-protein signaling of cells.

Regulation of 12-lipoxygenase by cytokines in vascular smooth muscle cells

Increasing evidence suggests that cytokines such as interleukin-1beta (IL-1), IL-4, and IL-8 may play an important role in the chronic inflammation and cellular growth observed in cardiovascular diseases. The lipoxygenase (LO) pathway of arachidonate metabolism has also been related to the pathology of hypertension and atherosclerosis. LO products have chemotactic, hypertrophic, and mitogenic effects in vascular cells, and the LO enzyme has been implicated in the oxidation of LDL. Furthermore, earlier studies have shown that vascular smooth muscle cell (VSMC) growth factors such as angiotensin II and platelet-derived growth factor can increase LO activity and expression in VSMCs. In the present study, we have examined whether vasoactive and inflammatory cytokines such as IL-1, IL-4, and IL-8 can modulate 12-LO activity and expression in porcine VSMCs and also whether they have growth-promoting effects in these cells. Treatment of porcine VSMCs with these cytokines led to significant increases in the levels of a cell-associated 12-LO product, 12-hydroxyeicosatetraenoic acid, as well as intracellular 12-LO enzyme activity. Furthermore, each of these cytokines led to a dose-dependent increase in 12-LO mRNA expression (333-base pair PCR product) as well as 12-LO protein expression (72 kD). In addition, all three interleukins could induce significant increases in VSMC DNA synthesis as well as proliferation. These results suggest that these cytokines have mitogenic effects in VSMCs and are also potent positive regulators of the 12-LO pathway. Thus, enhanced 12-LO activity and expression may be a key mechanism for cytokine-induced VSMC migration and proliferation.

Platelet-derived growth factor BB mediated regulation of 12-lipoxygenase in porcine aortic smooth muscle cells

Platelet-derived growth factor BB (PDGF) is a potent mitogen and chemoattractant for vascular smooth muscle cells (VSMC). In the present study, we have examined the effect of PDGF on the 12-lipoxygenase (12-LO) pathway of arachidonate metabolism in porcine aortic VSMC (PVSMC). The rationale for this is previous studies showing that LO products have growth and chemotactic effects in VSMC and that another VSMC growth factor, angiotensin II, is a potent positive regulator of 12-LO activity and expression. We observed that PDGF causes a significant increase in the formation of the 12-LO product, 12-hydroxyeicosatetraenoic acid (12-HETE) in PVSMC. In addition, PDGF also markedly increased leukocyte-type 12-LO messenger RNA and protein expression. PDGF-induced PVSMC migration was inhibited significantly by two LO blockers but not by a cyclooxygenase blocker. Furthermore, although the proliferative effects of PDGF on PVSMC were not altered by cell culture under hyperglycemic conditions (25 mM glucose, HG), the chemotactic effects of PDGF as well as those of 10% fetal calf serum were significantly greater in cells cultured in HG as compared to normal glucose conditions (5.5 mM), thus indicating a potential new mechanism for the accelerated cardiovascular disease usually observed in diabetes. These results indicate a novel mechanism for the biological effects of PDGF in leading to cardiovascular disease.

Neither too sweet nor too sour: problem peers, maternal control, and problem behavior in African American adolescents

This study examined whether maternal control protects African American adolescents from the negative influence of problem peers. Two forms of control were examined, behavioral control and psychological control. It was hypothesized that there would be a curvilinear relation between control and adolescent problem behavior, with the strength of the relationship and the amount of control optimal for adolescent development varying by the level of peer problem behavior. In general, data supported this model, particularly in regard to behavioral control, where the predicted curvilinear interaction occurred even after controlling for initial levels of problem behavior. The predicted curvilinear interaction between psychological control and peer problem behavior was statistically significant if initial levels of problem behavior were not controlled for but was not significant after controlling for initial problem behavior. These findings suggest that high-quality parenting can play a modest but critical role in the face of environmental adversity.

Mechanisms of ANG II-induced mitogenic responses: role of 12-lipoxygenase and biphasic MAP kinase

The potential mechanisms of angiotensin II (ANG II)-induced mitogenesis were studied in a Chinese hamster ovary fibroblast cell line overexpressing the rat vascular type 1a ANG II receptor (CHO-AT1a). ANG II had potent mitogenic effects in these CHO-AT1a cells, leading to a sustained increase in cell number as well as a dose-dependent increase in DNA synthesis. ANG II treatment also induced a biphasic elevation of mitogen-activated protein (MAP) kinase activity of both p42MAPK and p44MAPK with a rapid early peak at 5 min (2- to 6-fold) followed by a second sustained increase that reached a peak at 3 h (1.5- to 3-fold). We have previously shown that the 12-lipoxygenase (12-LO) pathway of arachidonate metabolism plays a key role in ANG II-induced growth of vascular smooth muscle and adrenal cells. In the present study, ANG II (10(-7) M) increased the formation of the 12-LO product, 12-hydroxyeicosatetraenoic acid (12-HETE). ANG II-induced DNA synthesis was inhibited by a specific LO inhibitor, cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate (CDC, 10 microM). In contrast, a cyclooxygenase blocker of arachidonate metabolism such as ibuprofen had no effect on ANG II-induced DNA synthesis. ANG II-induced DNA synthesis was also partially (32%) blocked by pertussis toxin (PTX). CDC and PTX also selectively blocked only the late (3 h) peak of ANG II-induced MAP kinase activity, suggesting that the late sustained peak of MAP kinase activity may be linked to the mitogenic effect of ANG II. Direct addition of 12-HETE (10(-7) M) led to a sustained increase in cell number similar to the effect of ANG II. 12-HETE also caused an increase in MAP kinase activity, and 12-HETE effects were blocked by PTX. These results suggest that ANG II-induced mitogenic response is associated with sustained MAP kinase activation and that LO activation may play a key role in this process.

Formation of an F2-isoprostane in vascular smooth muscle cells by elevated glucose and growth factors

Recently a series of non-cyclooxygenase-derived prostanoids were identified in vivo in humans and in animal models of free radical injury as products of free radical-catalyzed peroxidation of arachidonic acid. One of these, an F2-isoprostane, 8-epiprostaglandin F2 alpha (8-epi-PGF 2 alpha), is a potent renal vasoconstrictor and can increase vascular smooth muscle cell (VSMC) DNA synthesis. In the present study we have evaluated whether F2-isoprostanes play a role in diabetic vascular dysfunction by studying the formation of 8-epi-PGF2 alpha in porcine VSMC (PVSMC) cultured under hyperglycemic conditions. 8-Epi-PGF2 alpha levels were quantitated by a specific enzyme immunoassay. We also examined whether certain VSMC growth factors, such as angiotensin II, platelet-derived growth factor, and transforming growth factor-beta, could also regulate the formation of 8-epi-PGF2 alpha. We observed that PVSMC cultured under high glucose (HG) conditions produced significantly higher amounts of 8-epi-PGF2 alpha compared with normal glucose (NG) conditions (3.7 +/- 0.13 ng/10(6) cells in HG vs. 2.9 +/- 0.2 ng/10(6) cells in NG, P < 0.05). Furthermore, all three growth factors tested evoked significant dose-dependent formation of 8-epi-PGF2 alpha (ranging from 125 to 220% of control). These results suggest that 8-epi-PGF2 alpha formation, as a result of hyperglycemia or due to growth factor action, may lead to increased VSMC growth and contribute to the complications of diabetes and cardiovascular disease.

Interleukin-1 beta regulates the expression of a leukocyte type of 12-lipoxygenase in rat islets and RIN m5F cells

The leukocyte type of 12-lipoxygenase (12-LO) may play a role in inflammatory reactions in many cell types through the conversion of arachidonic acid to proinflammatory eicosanoids that include 12-hydroperoxyeicosatetraenoic acid and 12-hydroeicosatetraenoic acid. Previous studies demonstrating the presence of a functional 12-LO pathway in rat and human pancreatic beta-cells plus the recent cloning of a rat leukocyte type of 12-LO allowed us to evaluate whether inflammatory cytokines such as interleukin-1 beta (IL-1 beta) can regulate the beta-cell 12-LO enzyme pathway, thus providing a potential link between the cytotoxic effects of cytokines on pancreatic beta-cells and the proinflammatory effects of 12-LO products. We demonstrate that IL-1 beta induces 12-LO protein and messenger RNA (mRNA) expression in RIN m5F cells and 12-LO mRNA expression in rat islets. RIN m5F cells treated for 16 h with IL-1 beta (25, 50, and 100 ng/liter) showed a maximal 2-fold increase in the expression of a leukocyte form of 12-LO demonstrated by Western blots. A concomitant increase in 12-LO mRNA expression was seen at this time point using a highly sensitive competitive polymerase chain reaction assay. The increase in mRNA and protein expression was preceded by increased 12-LO pathway activity measured by a RIA for 12-S-HETE. Separate experiments using purified Sprague-Dawley rat islets also showed increased expression of 12-LO mRNA and enzyme activity in response to IL-1 beta. These results demonstrate that IL-1 beta can up-regulate 12-LO expression and activity in rat beta-cells.

Differential short- and long-term effects of insulin on ANG II action in human adrenal glomerulosa cells

Insulin is known to modulate several functions in bovine adrenal cells, including steroidogenesis and growth. However, the role of insulin in regulating aldosterone synthesis in human adrenal glomerulosa cells has not been studied. In the present studies, we have examined the acute and chronic effects of insulin on angiotensin II (ANG II)-induced aldosterone synthesis in cultured normal and adenomatous human adrenal glomerulosa cells. Short-term insulin treatment (1.5 h) resulted in inhibition of ANG II-induced aldosterone synthesis. In contrast, chronic treatment (30 h) resulted in potentiation of ANG II action. The 12-lipoxygenase pathway of arachidonate metabolism has been shown to play a key role in ANG II-induced aldosterone synthesis. The acute inhibitory effects of insulin were in part mediated by inhibition of the 12-lipoxygenase pathway. The chronic stimulatory effect of insulin seemed to be due at least in part to the upregulation of cytochrome P-450 side-chain cleavage enzyme levels. These findings suggest that insulin has a differential temporal effect on ANG II action and therefore may be an important regulator of ANG II-induced aldosterone synthesis in the adrenal.

Adolescent problem behavior: the effect of peers and the moderating role of father absence and the mother-child relationship

Examined the effect of peer problem behavior, the absence of a father or equivalent in the home, and the mother-adolescent relationship as predictors of adolescent problem behavior in a sample of 112 African American adolescents. Statistical analyses compared a moderator model to a mediational model and a cumulative risk model. As predicted, the moderator model was superior to the alternative models. Specifically, whereas the mediational model predicted that the effect of father absence and the mother-child relationship upon adolescent problem behavior would be mediated by peer problem behavior, neither effected peer problem behavior or adolescent problem behavior. Similarly, a cumulative risk index did not predict either child or parent reports of problem behavior and was not sensitive to specific contingencies that existed between the predictor variables. In contrast, an interactive, moderator model described the data quite well. This model suggested that father or equivalent absence magnifies the negative impact of peer problem behavior, while a positive mother-adolescent relationship attenuates this risk. A strong mother-adolescent relationship also served to protect adolescents in father-absent homes from the risk of peer problem behavior.

Negative cooperativity in the insulin-like growth factor-I receptor and a chimeric IGF-I/insulin receptor

Insulin and insulin-like growth factor-I (IGF-I) share a spectrum of metabolic and growth-promoting effects, mediated through homologous receptors that belong to the tyrosine kinase family. The dissociation rate of insulin from its receptor is affected by negative cooperativity, i.e. accelerates with increased receptor occupancy. The dose-response curve for the acceleration of tracer dissociation by unlabeled insulin has a distinct bell-shaped curve, with a progressive slowing down at insulin concentrations greater than 100 nM. The kinetics of the IGF-I interaction with its receptor has not been studied in such detail. In the present work, we report that while the IGF-I receptor exhibits negative cooperativity like the insulin receptor, the concentration dependence of the dissociation kinetics is distinct from that of native human insulin by not being bell-shaped, but monophasic like that of insulin analogues mutated at the hexamer-forming surface; it is changed to an insulin-type curve by substitution of IGF-I receptor's sequence including residues 382-565 with the homologous insulin receptor domain. The data suggest that like insulin, IGF-I has a bivalent binding mode and crosslinks two distinct areas of the two alpha subunits that are close, but distinct from the equivalent insulin receptor binding sites.

Role of the lipoxygenase pathway in angiotensin II-induced vascular smooth muscle cell hypertrophy

The 12-lipoxygenase pathway is a key mediator of angiotensin II (Ang II)-induced effects in the adrenal cortex. We also recently demonstrated that Ang II increases 12- and 15-lipoxygenase product levels in vascular smooth muscle cells. However, the relation between lipoxygenase activation and Ang II-induced vascular smooth muscle cell hypertrophy is not known. We studied the effects of Ang II and 12-lipoxygenase products on both total cell protein content and the levels of the matrix protein fibronectin in quiescent porcine aortic smooth muscle cells. Ang II-induced increases in cellular protein content were attenuated by the specific 12-lipoxygenase inhibitor baicalein; in contrast, the cyclooxygenase inhibitor ibuprofen had no effect. Direct addition of the 12-lipoxygenase product 12-S-hydroxyeicosatetraenoic acid increased total cell protein content. We have recently shown that porcine vascular smooth muscle cell growth is potentiated in high glucose (25 mmol/L) culture conditions. We observed that both Ang II and 12-S-hydroxyeicosatetraenoic acid induced a greater increase in protein content in cells cultured for two passages in high glucose. Furthermore, Ang II and 12-S-hydroxyeicosatetraenoic acid also markedly increased fibronectin levels in cells cultured in high glucose. These results suggest that 12-lipoxygenase activation plays a key role in Ang II-induced vascular smooth muscle cell hypertrophy. Furthermore, both Ang II and lipoxygenase effects are enhanced in cells cultured under hyperglycemic conditions.

Elevated glucose and angiotensin II increase 12-lipoxygenase activity and expression in porcine aortic smooth muscle cells

The lipoxygenase (LO) pathway of arachidonate metabolism has been suggested to play a key role in atherosclerosis and in mediating several actions of angiotensin II (AII). However, the relationship between LO activation and factors linked to accelerated diabetic vascular disease such as hyperglycemia and AII is not known. We have investigated the effect of high glucose (HG; 25 mM) and AII on LO activity as well as LO protein and mRNA expression in porcine aortic vascular smooth muscle cells (PVSMCs). We observed that cells cultured in HG had significantly higher levels of the cell-associated LO products 12- and 15-hydroxyeicosatetraenoic acids (HETEs). AII added to cells grown in HG specifically further increased only cell-associated 12-HETE levels. Using immunoblot analysis and reverse transcriptase PCRs, we demonstrated the presence in PVSMCs of porcine leukocyte-type 12-LO protein and mRNA, respectively. Furthermore, the levels of both were markedly upregulated by AII as well as by HG. These studies suggest that enhanced 12-LO activity and expression are mechanisms for accelerated vascular disease produced by HG and AII in diabetes mellitus.

Mechanism of angiotensin II-induced proliferation in bovine adrenocortical cells

The peptide hormone angiotensin-II (AII) is a potent vasoconstrictor and major regulator of aldosterone synthesis. In addition, AII also has growth-promoting effects. We have recently shown that the lipoxygenase (LO) pathway of arachidonic acid plays a major role in AII-induced aldosterone synthesis in adrenal glomerulosa cells. The LO pathway is also involved in the vasopressor and renin-inhibitory effects of AII. However, the role of LO products in AII-induced mitogenic effects have not yet been investigated. In the present studies we have evaluated the role of the LO pathway in AII-induced proliferative responses in a bovine adrenocortical cell clone termed AC1 cells. In addition, the potential receptor type and mechanism of AII-induced proliferation was studied by evaluating the effect of specific nonpeptide type 1 and type 2 AII receptor antagonists and the role of protein kinase-C (PKC). AII-induced DNA synthesis was significantly attenuated by two structurally dissimilar LO inhibitors, baicalein and phenidone. In addition, the LO product 12-hydroxyeicosatetraenoic acid (12-HETE) itself caused a significant increase in DNA synthesis, suggesting that the 12-LO pathway in part plays a role in AII-mediated mitogenesis. AII-induced proliferative responses were blocked by the type 1 AII receptor antagonist. Both AII- and 12-HETE-induced increases in DNA synthesis were markedly inhibited by two PKC blockers, staurosporine and sangivamycin. Further, both AII and 12-HETE could activate PKC by translocating it from the cytosol to the membrane fraction, as determined by Western immunoblotting. These results suggest that both 12-LO activation and protein kinase-C have an important role in AII-induced adrenal cell proliferation.

Vascular smooth muscle cells exhibit increased growth in response to elevated glucose

Diabetes mellitus is associated with an increased risk of cardiovascular disease. In order to elucidate the association between hyperglycemia and vascular complications, the growth patterns of vascular smooth muscle cells were studied under high glucose conditions. We examined the effect of culturing porcine aortic smooth muscle cells (PVSMC) in high glucose (25 mM, HG) on total cell protein, cell volume, DNA synthesis and cell number. We observed that cells cultured in HG had higher total cell protein content which was associated with increased cell volume as compared to the cells cultured under normoglycemic conditions (5.5 mM glucose, NG). PVSMC cultured in HG also had 1.4 fold increased growth rate and a greater fetal calf serum-induced DNA synthesis rate compared to cells cultured in NG. These observations suggest for the first time that elevated glucose could lead to both hypertrophic and hyperplastic effects in PVSMC. We also examined protein kinase C (PKC) activities as well as the cellular levels of the 12-lipoxygenase product, 12-hydroxyeicosatetraenoic acid (12-HETE) in NG and HG as possible mechanisms for the enhanced growth effects in HG. The results show that PVSMC cultured in HG have increased PKC activity as well as increased levels of 12-HETE. Therefore hyperglycemia may be linked to accelerated vascular disease by increasing smooth muscle cell growth and proliferation.

Assessment of injury risk in young children: a preliminary study of the injury behavior checklist

There is a need for practical and cost-effective measures of the behavioral characteristics that predict subsequent injury in children. Previous research has focused on the predictive power of child problem behavior (e.g., hyperactivity, aggression, noncompliance) and has found reliable, but relatively weak associations with injury frequency. In an effort to improve upon this level of prediction using child behavioral measures, a care-giver report checklist of specific "risky" behaviors was developed for toddlers and preschoolers, called the Injury Behavior Checklist (IBC). A preliminary test of the reliability and validity of this instrument was undertaken in a sample of middle-class families (N = 253). Results indicated that the IBC has acceptable reliability (internal consistency = .87; 1-month test-retest correlation = .81) and is able to significantly discriminate children with two or more injuries from those with one or none (p less than .001). Multiple regression analyses indicated that the IBC was a better predictor of injury than parent-reported levels of child problem behavior using the Conners Parent Rating Scale.