Childhood adversity and midlife suicidal ideation.

BACKGROUND: Childhood adversity predicts adolescent suicidal ideation but there are few studies examining whether the risk of childhood adversity extends to suicidal ideation in midlife. We hypothesized that childhood adversity predicts midlife suicidal ideation and this is partially mediated by adolescent internalizing disorders, externalizing disorders and adult exposure to life events and interpersonal difficulties. METHOD: At 45 years, 9377 women and men from the UK 1958 British Birth Cohort Study participated in a clinical survey. Childhood adversity was prospectively assessed at the ages of 7, 11 and 16 years. Suicidal ideation at midlife was assessed by the depressive ideas subscale of the Revised Clinical Interview Schedule. Internalizing and externalizing disorders were measured by the Rutter scales at 16 years. Life events, periods of unemployment, partnership separations and alcohol dependence were measured through adulthood. RESULTS: Illness in the household, paternal absence, institutional care, parental divorce and retrospective reports of parental physical and sexual abuse predicted suicidal ideation at 45 years. Three or more childhood adversities were associated with suicidal ideation at 45 years [odds ratio (OR) 4.31, 95% confidence interval (CI) 2.67-6.94]. Psychological distress at 16 years partially mediated the associations of physical abuse (OR 3.41, 95% CI 2.29-5.75), sexual abuse (OR 4.99, 95% CI 2.90-11.16) with suicidal ideation. Adult life events partially mediated the association of parental divorce (OR 6.34, 95% CI -7.16 to 36.75) and physical (OR 9.59, 95% CI 4.97-27.88) and sexual abuse (OR 6.59, 95% CI 2.40-38.36) with suicidal ideation at 45 years. CONCLUSIONS: Adversity in childhood predicts suicidal ideation in midlife, partially mediated by adolescent internalizing and externalizing disorders, adult life events and interpersonal difficulties. Understanding the pathways from adversity to suicidal ideation can inform suicide prevention and the targeting of preventive interventions.

Obesity and psychosocial impairment: mediating roles of health status, weight/shape concerns and binge eating in a community sample of women and men.

OBJECTIVES: We examined the relative importance of physical health status, weight/shape concerns and binge eating as mediators of the association between obesity and psychosocial impairment in a community sample of women and men. METHODS: Self-report measures of eating disorder features, perceived physical health and psychosocial functioning were completed by a general population sample of women and men classified as obese or non-obese (women: obese=276, non-obese=1220; men: obese=169, non-obese=769). Moderated mediation analysis was used to assess the relative importance of each of the putative mediators in accounting for observed associations between obesity and each outcome measure and possible moderation of these effects by sex. RESULTS: Weight/shape concerns and physical health were equally strong mediators of the association between obesity and psychosocial impairment. This was the case for both men and women and for each of three measures of psychosocial functioning-general psychological distress, life satisfaction and social support-employed. The effects of binge eating were modest and reached statistical significance only for the life satisfaction measure in men. CONCLUSIONS: A greater focus on body acceptance may be indicated in obesity prevention and weight-management programs.

Resveratrol induces brown-like adipocyte formation in white fat through activation of AMP-activated protein kinase (AMPK) α1.

OBJECTIVE: Development of brown-like/beige adipocytes in white adipose tissue (WAT) helps to reduce obesity. Thus we investigated the effects of resveratrol, a dietary polyphenol capable of preventing obesity and related complications in humans and animal models, on brown-like adipocyte formation in inguinal WAT (iWAT). METHODS: CD1 female mice (5-month old) were fed a high-fat diet with/without 0.1% resveratrol. In addition, primary stromal vascular cells separated from iWAT were subjected to resveratrol treatment. Markers of brown-like (beige) adipogenesis were measured and the involvement of AMP-activated protein kinase (AMPK) α1 was assessed using conditional knockout. RESULTS: Resveratrol significantly increased mRNA and/or protein expression of brown adipocyte markers, including uncoupling protein 1 (UCP1), PR domain-containing 16, cell death-inducing DFFA-like effector A, elongation of very long-chain fatty acids protein 3, peroxisome proliferator-activated receptor-γ coactivator 1α, cytochrome c and pyruvate dehydrogenase, in differentiated iWAT stromal vascular cells (SVCs), suggesting that resveratrol induced brown-like adipocyte formation in vitro. Concomitantly, resveratrol markedly enhanced AMPKα1 phosphorylation and differentiated SVC oxygen consumption. Such changes were absent in cells lacking AMPKα1, showing that AMPKα1 is a critical mediator of resveratrol action. Resveratrol also induced beige adipogenesis in vivo along with the appearance of multiocular adipocytes, increased UCP1 expression and enhanced fatty acid oxidation. CONCLUSIONS: Resveratrol induces brown-like adipocyte formation in iWAT via AMPKα1 activation and suggest that its beneficial antiobesity effects may be partly due to the browning of WAT and, as a consequence, increased oxygen consumption.

Mechanical Properties of Bisacryl-, Composite-, and Ceramic-resin Restorative Materials.

OBJECTIVE: Resin-based materials used in restorative dentistry are introduced at a fast pace with limited knowledge about their properties. Comparing properties of these materials from different restorative categories is lacking but can help the clinician in material selection. This study aimed to compare mechanical properties and wear resistance of bis-acryl-, composite-, and ceramic-resin restorative materials. METHODS AND MATERIALS: Bisacryl-resin (Bis-R, LuxaCrown, DMG), composite-resin (Com-R, Filtek Supreme Ultra, 3M Oral Care), and ceramic-resin (Cer-R, Enamic, VITA Zahnfabrik) specimens were prepared for mechanical tests: fracture toughness (FT) with and without initial thermomechanical loading using a mastication simulator, flexural strength (FS), and flexural modulus (FM), compressive strength (CS), and volumetric wear loss measurement. The datasets for FT and wear resistance were each analyzed using two-way ANOVA followed by pairwise comparisons or Tukey testing as appropriate. The datasets for FS, FM, and CS were analyzed using one-way ANOVA followed by the Tukey test. RESULTS: Analysis of FS, FM, and CS showed significant differences between materials, with all pairwise comparisons between materials showing significance. Analysis of FT resulted in a significant interaction between the material and treatment, with analysis of wear loss showing a significant interaction between the material and the number of cycles. CONCLUSIONS: Cer-R demonstrated superior FT, CS, and wear resistance compared to Bis-R and Comp-R materials. Fracture toughness of Bis-R increased after thermomechanical loading.

The psychosocial quality of work determines whether employment has benefits for mental health: results from a longitudinal national household panel survey.

OBJECTIVES: Although employment is associated with health benefits over unemployment, the psychosocial characteristics of work also influence health. We used longitudinal data to investigate whether the benefits of having a job depend on its psychosocial quality (levels of control, demands and complexity, job insecurity, and unfair pay), and whether poor quality jobs are associated with better mental health than unemployment. METHOD: Analysis of seven waves of data from 7,155 respondents of working age (44,019 observations) from a national household panel survey. Longitudinal regression models evaluated the concurrent and prospective association between employment circumstances (unemployment and employment in jobs varying in psychosocial job quality) and mental health, assessed by the MHI-5. RESULTS: Overall, unemployed respondents had poorer mental health than those who were employed. However the mental health of those who were unemployed was comparable or superior to those in jobs of the poorest psychosocial quality. This pattern was evident in prospective models: those in the poorest quality jobs showed greater decline in mental health than those who were unemployed (B = 3.03, p<0.05). The health benefits of becoming employed were dependent on the quality of the job. Moving from unemployment into a high quality job led to improved mental health (mean change score of +3.3), however the transition from unemployment to a poor quality job was more detrimental to mental health than remaining unemployed (-5.6 vs -1.0). CONCLUSIONS: Work of poor psychosocial quality does not bestow the same mental health benefits as employment in jobs with high psychosocial quality.

Mental health impairment associated with eating-disorder features in a community sample of women.

BACKGROUND AND AIMS: Impairment in mental health associated with eating-disorder features was examined in a large, general population sample of women aged 18 to 42 years. METHOD: Participants (n = 5255) completed self-report measures of eating-disordered behaviour, mental health functioning, height and weight and socio-demographic information. RESULTS: The most common eating-disorder features were extreme concerns about weight or shape (14.6%), subjective overeating (12.7%), objective overeating (10.6%) and extreme concerns about dietary intake (10.4%). In multivariable analysis, in which mental health functioning was regressed on eating-disorder features, while also controlling for age and body weight, objective overeating (ß  =  -0.07), subjective overeating (ß â€Š = -0.07), extreme dietary restriction (ß â€Š=  -0.06) and extreme concerns about eating (ß â€Š=  -0.04) showed small, but statistically significant associations with mental health impairment, whereas extreme weight or shape concerns showed a very strong association (ß â€Š=  -0.24). CONCLUSIONS: From a clinical perspective, the findings are consistent with the importance attached to the "over-evaluation" of weight or shape as a core component of eating-disorder psychopathology. From a public health perspective, the findings indicate the need to conceive of body dissatisfaction as a target for health promotion in its own right.

Lifecourse socioeconomic predictors of midlife drinking patterns, problems and abstention: findings from the 1958 British Birth Cohort Study.

BACKGROUND: Research suggests that outcomes associated with drinking may differ depending upon patterns of consumption, drinking related symptoms and social problems. This paper investigated socioeconomic predictors (measuring multiple indices, period and consistency of disadvantage) of midlife drinking patterns. METHODS: Socioeconomic information from the 1958 British Birth Cohort Study (n=9146) included: manual socioeconomic position and owner/buyer residential tenure (7, 11, 16, 33 and 42 y), and educational attainment (33 y). At 45 y, the overlap between drinking patterns was explored using the Alcohol Use Disorders Identification Test. Patterns included: 'Moderate-binge' (binge drinkers with low-problem scores, consuming within UK sensible drinking weekly guidelines); Low-Problem Heavy (LPH) drinkers (regardless of binge); 'Problem' (and heavy or binge) and 'Non-/occasional' (< or =monthly) drinkers. These categories were compared to 'Low-risk' drinkers. RESULTS: Socioeconomic disadvantage was consistently associated with moderate-binge, non-/occasional and problem but not LPH drinking. The highest risk was associated with multiple and persistent disadvantage across childhood and adulthood; this risk was partially accounted for education. Non-/occasional and moderate-binge drinking was predicted by disadvantage during childhood alone. The socioeconomic disadvantage of non-/occasional drinkers was not explained by past problem or heavy drinking. CONCLUSIONS: Socioeconomic disadvantage across the lifecourse was consistently linked to specific drinking patterns. Furthermore, associations linking socioeconomic disadvantage with drinking patterns will typically be underestimated if multiple and persistent disadvantage is not investigated. The role of persistent socioeconomic disadvantage in the poor health of non-drinkers and moderate-binge drinkers needs investigation. The findings support current initiatives targeting the reduction of social and individual costs associated with specific drinking patterns.

Psychosocial work characteristics and anxiety and depressive disorders in midlife: the effects of prior psychological distress.

OBJECTIVES: The association between work stressors and adult psychiatric diagnoses may be biased by prior psychological distress influencing perception of work or selection into unfavourable work. This study examines the extent to which the association between work stressors and adult psychiatric diagnoses is explained by associations with earlier psychological distress and whether childhood and early adulthood psychological distress influences reported midlife work characteristics. METHODS: Follow-up at 45 years of age of 8243 participants in paid employment from the 1958 British Birth Cohort. Karasek's work characteristics and psychiatric diagnoses (Revised Clinical Interview Schedule) were measured at 45 years. Childhood internalising and externalising problems were measured at 7, 11 and 16 and malaise at 23 and 33 years. RESULTS: Internalising behaviours in childhood and early adult psychological distress predicted adverse work characteristics in mid-adulthood. High job demands (women: relative risk (RR) = 1.75, 95% CI 1.2 to 2.5; men: RR = 4.99, 95% CI 2.5 to 10.1), low decision latitude (RR = 1.46, 95% CI 1.1 to 1.9), high job strain (OR = 1.88, 95% CI 1.5 to 2.4), low work social support (RR = 1.97, 95% CI 1.5 to 2.6) and high job insecurity (OR = 1.86, 95% CI 1.4 to 2.4) were associated with mid-adulthood diagnoses. The association between work stressors and mid-adulthood diagnoses remained after adjustment for internalising behaviours and malaise at 23 and 33 years although diminished slightly in magnitude (eg, adjusted RR for support = 1.82, 95% CI 1.4 to 2.4; job strain OR = 1.78, 95% CI 1.4 to 2.3). CONCLUSIONS: Childhood and early adulthood psychological distress predict work characteristics in mid-adulthood but do not explain the associations of work characteristics with depressive episode and generalised anxiety disorder in midlife. Work stressors are an important source of preventable psychiatric diagnoses in midlife. Psychological distress may influence selection into less advantaged occupations with poorer working conditions that may increase the risk of future depressive and anxiety disorders.

Self-report versus interview assessment of purging in a community sample of women.

OBJECTIVE AND METHODS: Agreement between self-report and interview assessment of purging behaviours was examined in a community sample of women with a high level of eating disorder symptoms (n = 324) who completed both the Eating Disorder Examination (EDE) and Eating Disorder Examination Questionnaire (EDE-Q). RESULTS: Of 46 individuals who reported any use of self-induced vomiting or laxative misuse on the questionnaire, 19 (41.7%) denied these behaviours when subsequently questioned in a face-to-face interview. These individuals had lower levels of eating disorder psychopathology, functional impairment and general psychological distress, than participants who reported purging on both the questionnaire and at interview (n = 27). CONCLUSIONS: The assumption of interview superiority in the assessment of specific aspects of eating disorder psychopathology should not be uncritically accepted. Caution should be exercised in drawing conclusions concerning the level of agreement between self-report and interview assessment of purging based on research in clinical samples.

Resveratrol enhances brown adipocyte formation and function by activating AMP-activated protein kinase (AMPK) α1 in mice fed high-fat diet.

SCOPE: Enhancing the formation and function of brown adipose tissue (BAT) increases thermogenesis and hence reduces obesity. Thus, we investigate the effects of resveratrol (Resv) on brown adipocyte formation and function in mouse interscapular BAT (iBAT). METHODS AND RESULTS: CD1 mice and stromal vascular cells (SVCs) isolated from iBAT were treated with Resv. Expression of brown adipogenic and thermogenic markers, and involvement of AMP-activated protein kinase (AMPK)α1 were assessed. In vivo, Resv-enhanced expression of brown adipogenic markers, PR domain-containing 16 (PRDM16) and thermogenic genes, uncoupling protein 1 (UCP1) and cytochrome C in iBAT, along with smaller lipid droplets, elevated AMPKα activity and increased oxygen consumption. Meanwhile, Resv promoted expression of PRDM16, UCP1, PGC1α, cytochrome C and pyruvate dehydrogenase (PDH) in differentiated iBAT SVCs, suggesting that Resv enhanced brown adipocyte formation and function in vitro. In addition, Resv stimulated AMPKα and oxygen consumption in differentiated iBAT SVCs. However, the promotional effects of Resv were diminished by AMPK inhibition or AMPKα1 knockout, implying the involvement of AMPKα1 in this process. CONCLUSION: Resv enhanced brown adipocyte formation and thermogenic function in mouse iBAT by promoting the expression of brown adipogenic markers via activating AMPKα1, which contributed to the anti-obesity effects of Resv.

Eating Disorder Examination Questionnaire (EDE-Q): norms for young adult women.

In order to establish norms for the Eating Disorder Examination Questionnaire (EDE-Q) among young adult women, the questionnaire was administered to a large general population sample of women aged 18-42 yr in the Australian Capital Territory (ACT) region of Australia. Normative data were derived for EDE-Q subscales and for the occurrence of specific eating disorder behaviours, for each of five age bands (18-22, 23-27, 28-32, 33-37, 38-42 yr). Mean scores (SDs) for the Restraint, Eating Concern, Weight Concern and Shape Concern subscales for the total sample (n = 5,255) were, respectively, 1.30 (1.40), 0.76 (1.06), 1.79 (1.51) and 2.23 (1.65). The mean global score was 1.52 (1.25). The regular occurrence of objective and subjective overeating episodes was reported by 10.6% and 12.7% of participants, respectively. The regular use of self-induced vomiting, laxative misuse, and use of diuretics, was reported by 1.4%, 1.0%, and 0.3%, of participants, respectively, while 2.2% of participants reported regularly using diet pills. "Extreme dietary restraint" and "excessive exercise" were reported by 3.4% and 4.9% of participants, respectively. Both attitudinal and behavioural features of eating disorder psychopathology tended to decrease with increasing age. These data will inform researchers intending to use the EDE-Q in epidemiological studies.

Corticosterone regulation of insulin-like growth factor I, IGF-binding proteins, and growth in streptozotocin-induced diabetic rats.

The experiments reported herein were conducted to determine how corticosterone regulates growth and plasma insulin-like growth factor (IGF) I and IGF-binding protein (IGFBP) concentrations in normal and streptozotocin (STZ)-induced diabetic rats. Males were bilaterally adrenalectomized (Ax) or sham Ax and given intravenous injections of 0, 30, or 65 mg STZ per kg body wt (0, 30, or 65 STZ) to induce varying degrees of insulin deficiency and implanted with 100-mg pellets containing 0, 40, or 80% corticosterone in cholesterol. Changes in plasma IGFBP concentrations were determined by Western ligand blotting or immunoblots. Neither IGFBP-5 nor IG-FBP-6 was detected in any of the treatment groups. Plasma IGFBP-2 was elevated and IGF-I was reduced in the nondiabetic Ax rats compared with sham Ax controls, but plasma IGFBP-3 and -4 were not significantly changed. Adrenalectomy had no affect on tibial growth or plasma IGFBP-1 in these animals. Plasma IGF-I, IGFBP-1 and -3, and tibial growth were equal among 0, 30, and 65 STZ Ax rats that did not receive corticosterone. Plasma IGFBP-4 was inversely related to the amount of STZ injected in these animals, and IGFBP-2 was elevated in those given the high dose of STZ. In the 0 STZ Ax rats, plasma IGF-I and IGFBP-3 increased in proportion to the corticosterone implant dose, but IGFBP-1 was unaffected. By contrast, IGF-I and IGFBP-3 were unaltered by corticosterone in the 30 STZ Ax rats, and IGFBP-1 increased in proportion with the dose of corticosterone.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of the chicken homeobox-containing gene GHox-8 during embryonic chick limb development.

Homeobox-containing genes are thought to be involved in the regulation of pattern formation and specification of positional information during vertebrate limb development. Because of its accessibility to microsurgical manipulation, the developing chick limb bud provides a powerful system for investigating the role of homeobox-containing genes in patterning events. We report the isolation from a chick limb bud cDNA library of a chicken homeobox-containing cDNA, which on the basis of its nucleotide and deduced amino acid sequences has been identified as the chicken cognate of mouse Hox-8. The gene encoding this chicken (Gallus) homeobox-containing cDNA has been designated GHox-8, and is a member of a family of vertebrate homeobox-containing genes that are highly similar in sequence to the Drosophila msh gene. GHox-8 encodes an mRNA transcript of about 3 kb that is expressed at several early stages of chick limb development. In situ and dot-blot hybridization analyses have revealed that GHox-8 is expressed in limb bud mesoderm in a temporal and spatial fashion consistent with its involvement in specifying anterior positional identity. At early stages (stages 20-21) of chick limb development when positional values along the anterior-posterior (A-P) axis are being specified, GHox-8 is expressed in high amounts in the anterior mesoderm of the wing bud. Little expression of the gene is detectable in the middle region of the wing bud mesoderm or in the posterior mesoderm that contains the zone of polarizing activity, which is thought to be the source of a diffusible morphogen, possibly retinoic acid, that specifies the A-P positional values of the skeletal elements of the limb according to its local concentration. Similarly, at later stages of development (stages 23-25), high expression of GHox-8 is localized to the proximal anterior periphery of the wing bud, with no detectable expression in the proximal dorsal and ventral (myogenic) regions, or in the chondrogenic central core. In the proximal posterior periphery of the wing bud at these later stages of development, expression of GHox-8 is limited to a small region in the mid-proximal periphery corresponding to the posterior necrotic zone in which programmed cell death is occurring. The possible involvement of GHox-8 in programmed cell death during limb development is also suggested by the fact that it is expressed in the necrotic interdigital mesenchyme in 6-7 day (stage 31-32) wing buds.(ABSTRACT TRUNCATED AT 400 WORDS)

Isolation and characterization of myostatin complementary deoxyribonucleic acid clones from two commercially important fish: Oreochromis mossambicus and Morone chrysops.

In mammals, skeletal muscle mass is negatively regulated by a muscle-derived growth/differentiating factor named myostatin (MSTN) that belongs to the transforming growth factor-beta superfamily. Although putative MSTN homologs have been identified from several vertebrates, nonmammalian orthologs remained poorly defined. Thus, we isolated and characterized MSTN complementary DNA clones from the skeletal muscle of the tilapia Oreochromis mossambicus and the white bass Morone chrysops. The nucleic and amino acid sequences from both fish species are highly homologous to the previously identified mammalian and avian orthologs, and both possess conserved cysteine residues and putative RXXR proteolytic processing sites that are common to all transforming growth factor-beta family members. Western blotting of conditioned medium from human embryonal kidney (HEK293) cells overexpressing a His-tagged tilapia MSTN indicates that the secreted fish protein is processed in a manner similar to mouse MSTN. However, in contrast to mice, MSTN expression in tilapia is not limited to skeletal muscle as it occurs in many tissues. Furthermore, the timing of MSTN expression in developing tilapia larvae coincides with myogenesis. These results suggest that the biological actions of MSTN in the tilapia and possibly in other fishes may not be limited to myocyte growth repression, but may additionally influence different cell types and organ systems.

Differential expression of a novel seven transmembrane domain protein in epididymal fat from aged and diabetic mice.

To identify novel seven transmembrane domain proteins from 3T3-L1 adipocytes, we used PCR to amplify 3T3-L1 adipocyte complementary DNA (cDNA) with primers homologous to the N- and C-termini of pancreatic glucagon-like peptide-1 (GLP-1) receptor. We screened a cDNA library prepared from fully differentiated 3T3-L1 adipocytes using a 500-bp cDNA PCR product probe. Herein describes the isolation and characterization of a 1.6-kb cDNA clone that encodes a novel 298-amino acid protein that we termed TPRA40 (transmembrane domain protein of 40 kDa regulated in adipocytes). TPRA40 has seven putative transmembrane domains and shows little homology with the known GLP-1 receptor or with other G protein-coupled receptors. The levels of TPRA40 mRNA and protein were higher in 3T3-L1 adipocytes than in 3T3-L1 fibroblasts. TPRA40 is present in a number of mouse and human tissues. Interestingly, TPRA40 mRNA levels were significantly increased by 2- to 3-fold in epididymal fat of 24-month-old mice vs. young controls as well as in db/db and ob/ob mice vs. nondiabetic control littermates. No difference in TPRA40 mRNA levels was observed in brain, heart, skeletal muscle, liver, or kidney. Furthermore, no difference in TPRA40 expression was detected in brown fat of ob/ob mice when compared with age-matched controls. Taken together, these data suggest that TPRA40 represents a novel membrane-associated protein whose expression in white adipose tissue is altered with aging and type 2 diabetes.

Pancreatic glucagon-like peptide-1 receptor couples to multiple G proteins and activates mitogen-activated protein kinase pathways in Chinese hamster ovary cells.

Chinese hamster ovary (CHO) cells stably expressing the human insulin receptor and the rat glucagon-like peptide-1 (GLP-1) receptor (CHO/GLPR) were used to study the functional coupling of the GLP-1 receptor with G proteins and to examine the regulation of the mitogen-activated protein (MAP) kinase signaling pathway by GLP-1. We showed that ligand activation of GLP-1 receptor led to increased incorporation of GTP-azidoanilide into Gs alpha, Gq/11 alpha, and Gi1,2 alpha, but not Gi3 alpha. GLP-1 increased p38 MAP kinase activity 2.5- and 2.0-fold over the basal level in both CHO/GLPR cells and rat insulinoma cells (RIN 1046-38), respectively. Moreover, GLP-1 induced phosphorylation of the immediate upstream kinases of p38, MKK3/MKK6, in CHO/GLPR and RIN 1046-38 cells. Ligand-stimulated GLP-1 receptor produced 1.45- and 2.7-fold increases in tyrosine phosphorylation of 42-kDa extracellular signal-regulated kinase (ERK) in CHO/GLPR and RIN 1046-38 cells, respectively. In CHO/GLPR cells, these effects of GLP-1 on the ERK and p38 MAP kinase pathways were inhibited by pretreatment with cholera toxin (CTX), but not with pertussis toxin. The combination of insulin and GLP-1 resulted in an additive response (1.6-fold over insulin alone) that was attenuated by CTX. In contrast, the ability of insulin alone to activate these pathways was insensitive to either toxin. Our study indicates a direct coupling between the GLP-1 receptor and several G proteins, and that CTX-sensitive proteins are required for GLP-1-mediated activation of MAP kinases.

Pediatric equestrian injuries: assessing the impact of helmet use.

OBJECTIVE: To assess the impact of helmet use on the pattern, and severity of pediatric equestrian injuries. DESIGN: A prospective observational study of all children less than 15 years of age who were brought to the University of Virginia children's Emergency Department with horse-related injuries. RESULTS: During the two-year period of the study, 32 children were evaluated. Two children were injured when a horse stepped on them. Thirty children fell from or were thrown from a horse. Of these, 20 were wearing a helmet. Head injuries were more frequent in those patients not wearing helmets. The mean Modified Injury Severity Scale (MISS) score for riders without a helmet (12.9) was significantly higher (more severe) than that for helmeted riders (2.8). All three patients with a Glascow Coma Score < 15 on arrival were not wearing a helmet at the time of injury. The frequency of hospitalization was significantly higher for those not wearing a helmet. Compared with other common mechanisms of childhood injury the mean Modified Injury Severity Scale score of injured riders was exceeded only by that of pedestrians struck by a car. CONCLUSION: Equestrian injuries are more severe than those suffered from other common pediatric mechanisms. Helmet use is associated with decreased frequency and severity of central nervous system injury.

Endocrine regulation of G-protein subunit production in an animal model of type 2 diabetes mellitus.

Adipocyte beta-adrenergic sensitivity is compromised in animal models of obesity and type 2 diabetes. Although changes in the membrane concentrations of G-protein alpha subunits (Galpha) have been implicated, it remains to be determined how these changes are affected by insulin resistance in the different animal models. Because previous studies used young animals, we measured the concentrations of Galpha and Gbeta subunits in epididymal fat from aged (48 weeks old) db/db mice and from their lean littermates to more closely reproduce the model of type 2 diabetes mellitus. Levels of immunoreactive Galphas, Galphai(1/2), Galphao and Galphaq/11 were all significantly greater in adipocyte membranes from the db/db mice than in membranes from their lean non-diabetic littermate controls. Levels of Galphai(1) and Galphai(2) were also individually determined and although they appeared to be slightly higher in db/db membranes, these differences were not significant. Although the levels of both Galphas isoforms were elevated, levels of the 42 and 46 kDa proteins rose by approximately 42% and 20% respectively, indicating differential protein processing of Galphas. By contrast, levels of Galphai3 were similar in the two groups. The levels of common Gbeta and Gbeta2 were also elevated in db/db mice, whereas Gbeta1 and Gbeta4 levels were not different. To determine whether these changes were due to insulin resistance per se or to elevated glucocorticoid production, G-protein subunit levels were quantified in whole cell lysates from 3T3-L1 adipocytes that were stimulated with different concentrations of either insulin or corticosterone. Although none of the subunit levels was affected by insulin, the levels of both Galphas isoforms were increased equally by corticosterone in a concentration-dependent manner. Since glucocorticoids are known regulators of Galphas gene expression in many cell types and in adipocytes from diabetic rodents, the results presented herein appear to more accurately reflect diabetic pathophysiology than do those of previous studies which report a decrease in Galphas levels. Taken together, these results indicate that most of the selective changes in G-protein subunit production in adipocytes from this animal model of type 2 diabetes may not be due to diminished insulin sensitivity, but may be due to other endocrine or metabolic abnormalities associated with the diabetic phenotype.

Insulin regulation of a novel WD-40 repeat protein in adipocytes.

A 400 bp PCR product generated with degenerate primers derived from the glucagon-like peptide-1 receptor was used to screen a rat skeletal muscle cDNA library. The predicted amino acid sequence of the 978 bp open reading frame has a predicted M(r) of 35 804, an estimated isoelectric point (pI) of 5.31 and contains seven WD-40 repeats, which are common to G-protein beta subunits (Gbeta). Although chemically and structurally similar to Gbeta subunits, the predicted amino acid sequence, when compared with the previously cloned Gbeta isoforms, was found to be only 31-41% similar and thus was named Gbeta-like (GbetaL, 'Gable'). Western blotting of whole-cell lysates and immunoprecipitates of membrane and cytosolic fractions of HEK 293 cells stably overexpressing a carboxy-terminal His-tagged GbetaL indicates that the protein is cytosolic and that it migrates at 42 kDa. A 4 kb transcript was detected in all tissues surveyed by northern blotting; however, an additional 2 kb transcript was detected in testis. Expression of GbetaL mRNA was highest in the brain and testis, followed by lung, heart, kidney, skeletal muscle, spleen and liver. In addition, reverse transcriptase/PCR showed that several other tissues and cell lines express GbetaL. The ubiquitous nature of the tissue expression pattern of GbetaL is similar to that of the insulin receptor, which suggests that insulin may influence GbetaL expression. Indeed, GbetaL protein and mRNA levels, in fully differentiated 3T3-L1 adipocytes, were upregulated by insulin in a concentration-dependent fashion. These changes were highly sensitive to insulin stimulation, being minimally affected by doses as low as 0.1 nM and maximally elevated by 1 nM doses. These data suggest that insulin regulates GbetaL production and imply that some of the actions of insulin may be mediated, in part, by this novel intracellular protein.

Expression of P.69/pertactin from Bordetella pertussis in a baculovirus/insect cell expression system: protective properties of the recombinant protein.

The surface antigen P.69/pertactin of Bordetella pertussis has been expressed using the polyhedron promoter of baculovirus in cultured insect cells. Either full-length or truncated prn DNA was used to express P.69 pertactin. The full-length gene gave rise to low levels of P.93 precursor protein, some of which was processed to P.69. The shortened prn expressed P.69 pertactin directly at levels up to 3.5 mg per litre. P.69 vaccinated animals were protected against aerosol challenge with virulent B. pertussis bacteria.