The effects of latent variables in the development of comorbidity among common mental disorders

Background: Although numerous studies have examined the role of latent predispositions to internalizing and externalizing disorders in the structure of comorbidity among common mental disorders, none examined latent predispositions in predicting development of comorbidity. Methods: A novel method was used to study the role of latent variables in the development of comorbidity among lifetime DSM-IV disorders in the National Comorbidity Surveys. Broad preliminary findings are briefly presented to describe the method. The method used survival analysis to estimate time-lagged associations among 18 lifetime DSM-IV anxiety, mood, behavior, and substance disorders. A novel estimation approach examined the extent to which these predictive associations could be explained by latent canonical variables representing internalizing and externalizing disorders. Results: Consistently significant positive associations were found between temporally primary and secondary disorders. Within-domain time-lagged associations were generally stronger than between-domain associations. The vast majority of associations were explained by a model that assumed mediating effects of latent internalizing and externalizing variables, although the complexity of this model differed across samples. A number of intriguing residual associations emerged that warrant further investigation. Conclusions: The good fit of the canonical model suggests that common causal pathways account for most comorbidity among the disorders considered. These common pathways should be the focus of future research on the development of comorbidity. However, the existence of several important residual associations shows that more is involved than simple mediation. The method developed to carry out these analyses provides a unique way to pinpoint these significant residual associations for subsequent focused study. Depression and Anxiety, 2011. (c) 2011 Wiley-Liss, Inc

Saliva Samples as A Tool to Study the Effect of Meal Timing on Metabolic And Inflammatory Biomarkers

: Meal timing affects metabolic regulation in humans. Most studies use blood samples for their investigations. Saliva, although easily available and non-invasive, seems to be rarely used for chrononutritional studies. In this pilot study, we tested if saliva samples could be used to study the effect of timing of carbohydrate and fat intake on metabolic rhythms. In this cross-over trial, 29 nonobese men were randomized to two isocaloric 4-week diets: (1) carbohydrate-rich meals until 13:30 and high-fat meals between 16:30 and 22:00 or (2) the inverse order of meals. Stimulated saliva samples were collected every 4 h for 24 h at the end of each intervention, and levels of hormones and inflammatory biomarkers were assessed in saliva and blood. Cortisol, melatonin, resistin, adiponectin, interleukin-6 and MCP-1 demonstrated distinct diurnal variations, mirroring daytime reports in blood and showing significant correlations with blood levels. The rhythm patterns were similar for both diets, indicating that timing of carbohydrate and fat intake has a minimal effect on metabolic and inflammatory biomarkers in saliva. Our study revealed that saliva is a promising tool for the non-invasive assessment of metabolic rhythms in chrononutritional studies, but standardisation of sample collection is needed in out-of-lab studies

Detection of ubiquitin–proteasome enzymatic activities in cells: Application of activity-based probes to inhibitor development

AbstractBackground: Synthetic probes that mimic natural substrates can enable the detection of enzymatic activities in a cellular environment. One area where such activity-based probes have been applied is the ubiquitin–proteasome pathway, which is emerging as an important therapeutic target. A family of reagents has been developed that specifically label deubiquitylating enzymes (DUBs) and facilitate characterization of their inhibitors. Scope of review: Here we focus on the application of probes for intracellular DUBs, a group of specific proteases involved in the ubiquitin proteasome system. In particular, the functional characterization of the active subunits of this family of proteases that specifically recognize ubiquitin and ubiquitin-like proteins will be discussed. In addition we present the potential and design of activity-based probes targeting kinases and phosphatases to study phosphorylation. Major conclusions: Synthetic molecular probes have increased our understanding of the functional role of DUBs in living cells. In addition to the detection of enzymatic activities of known members, activity-based probes have contributed to a number of functional assignments of previously uncharacterized enzymes. This method enables cellular validation of the specificity of small molecule DUB inhibitors. General significance: Molecular probes combined with mass spectrometry-based proteomics and cellular assays represent a powerful approach for discovery and functional validation, a concept that can be expanded to other enzyme classes. This addresses a need for more informative cell-based assays that are required to accelerate the drug development process. This article is part of a Special Issue entitled: Ubiquitin Drug Discovery and Diagnostics

Label-free quantitative proteomics reveals regulation of interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) and 5'-3'-exoribonuclease 2 (XRN2) during respiratory syncytial virus infection

A large quantitative study was carried out to compare the proteome of respiratory syncytial virus (RSV) infected versus uninfected cells in order to determine novel pathways regulated during viral infection. RSV infected and mock-infected HEp2 cells were lysed and proteins separated by preparative isoelectric focussing using offgel fractionation. Following tryptic digestion, purified peptides were characterized using label-free quantitative expression profiling by nano-ultra performance liquid chromatography coupled to electrospray ionisation mass spectrometry with collision energy ramping for all-ion fragmentation (UPLC-MSE). A total of 1352 unique cellular proteins were identified and their abundance compared between infected and non-infected cells. Ingenuity pathway analysis revealed regulation of several central cellular metabolic and signalling pathways during infection. Selected proteins that were found regulated in RSV infected cells were screened by quantitative real-time PCR for their regulation on the transcriptional level. Synthesis of interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) and 5'-3'-exoribonuclease 2 (XRN2) mRNAs were found to be highly induced upon RSV infection in a time dependent manner. Accordingly, IFIT3 protein levels accumulated during the time course of infection. In contrast, little variation was observed in XRN2 protein levels, but different forms were present in infected versus non-infected cells. This suggests a role of these proteins in viral infection, and analysis of their function will shed further light on mechanisms of RNA virus replication and the host cell defence machinery

Taming troubled teens: The social production of mental morbidity amongst young mothers in Pelotas, Brazil

Copyright @ 2011 Elsevier Ltd. This is a post-print version of the article. The published version of the article can be viewed at the link below.Explanations for the association between teen-childbearing and subsequent mental morbidity vary considerably, from those based on neurological theories of development to those investigating underlying social and economic determinants. Based on longitudinal epidemiological and ethnographic sub-studies of the 1982 Pelotas birth cohort study, this paper explores the hypothesis that teen childbearing and subsequent mental morbidity have become associated through the interplay of culture, society, and biology in situations where teen pregnancy has become a stigmatised object of scientific and public health attention. Results show that the effect of teen childbearing on subsequent mental morbidity remained significant in the multivariate analysis. Ethnographic analysis, together with epidemiological effect modification analyses, suggest that this association is partially accounted for by the fact that it is more pronounced amongst a specific subgroup of women of low socio-economic status who, being more politicised about societal injustice, were also more critically engaged with – and thus troubled by – the inequitable institutionalisation of life-cycle transitions. With time, these women became highly critical of the institutionalised identification of early childbearing as a key violation of life-cycle norms and the differential class-based application of scientific knowledge on its causes and consequences. Public health campaigns should consider how the age-based institutionalisation of developmental norms has enabled the stigmatisation of those identified as transgressors.The 1982 cohort study has been funded by The Wellcome Trust, the World Health Organisation, the PanAmerican Health Organisation, the European Union, the Programa Nacional para Centros de Excelência (PRONEX), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), the Brazilian Ministry of Health, and the Fundação de Amparo à Pesquisa do Rio Grande do Sul (Fapergs). D Béhague received support from a US National Science Foundation Doctoral Fellowship and a Postdoctoral Training Fellowship from The Wellcome Trust (Grant no. GR077175MA)

a randomized controlled trial

Diurnal carbohydrate and fat distribution modulates glycaemic control in rodents. In humans, the optimal timing of both macronutrients and its effects on glycaemic control after prolonged consumption are not studied in detail. In this cross-over trial, 29 non-obese men were randomized to two four-week diets: (1) carbohydrate-rich meals until 13.30 and fat-rich meals between 16.30 and 22.00 (HC/HF) versus (2) inverse sequence of meals (HF/HC). After each trial period two meal tolerance tests were performed, at 09.00 and 15.40, respectively, according to the previous intervention. On the HF/HC diet, whole-day glucose level was increased by 7.9% (p = 0.026) in subjects with impaired fasting glucose and/or impaired glucose tolerance (IFG/IGT, n = 11), and GLP-1 by 10.2% (p = 0.041) in normal glucose-tolerant subjects (NGT, n = 18). Diet effects on fasting GLP-1 (p = 0.009) and PYY (p = 0.034) levels were observed in IFG/IGT, but not in NGT. Afternoon decline of glucose tolerance was more pronounced in IFG/IGT and associated with a stronger decrease of postprandial GLP-1 and PYY levels, but not with changes of cortisol rhythm. In conclusion, the HF/HC diet shows an unfavourable effect on glycaemic control in IFG/IGT, but not in NGT subjects. Consequently, large, carbohydrate-rich dinners should be avoided, primarily by subjects with impaired glucose metabolism

Transitions of care from child and adolescent mental health services to adult mental health services (TRACK Study) : a study of protocols in Greater London

Background: Although young people's transition from Child and Adolescent Mental Health Services (CAMHS) to Adult Mental Health Services (AMHS) in England is a significant health issue for service users, commissioners and providers, there is little evidence available to guide service development. The TRACK study aims to identify factors which facilitate or impede effective transition from CAHMS to AMHS. This paper presents findings from a survey of transition protocols in Greater London. Methods: A questionnaire survey (Jan-April 2005) of Greater London CAMHS to identify transition protocols and collect data on team size, structure, transition protocols, population served and referral rates to AMHS. Identified transition protocols were subjected to content analysis. Results: Forty two of the 65 teams contacted (65%) responded to the survey. Teams varied in type (generic/targeted/in-patient), catchment area (locality-based, wider or national) and transition boundaries with AMHS. Estimated annual average number of cases considered suitable for transfer to AMHS, per CAMHS team (mean 12.3, range 0–70, SD 14.5, n = 37) was greater than the annual average number of cases actually accepted by AMHS (mean 8.3, range 0–50, SD 9.5, n = 33). In April 2005, there were 13 active and 2 draft protocols in Greater London. Protocols were largely similar in stated aims and policies, but differed in key procedural details, such as joint working between CAHMS and AMHS and whether protocols were shared at Trust or locality level. While the centrality of service users' involvement in the transition process was identified, no protocol specified how users should be prepared for transition. A major omission from protocols was procedures to ensure continuity of care for patients not accepted by AMHS. Conclusion: At least 13 transition protocols were in operation in Greater London in April 2005. Not all protocols meet all requirements set by government policy. Variation in protocol-sharing organisational units and transition process suggest that practice may vary. There is discontinuity of care provision for some patients who 'graduate' from CAMHS services but are not accepted by adult services