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1.  Identification and Characterisation of a Nuclear Localisation Signal in the SMN associated protein, Gemin4 
Gemin4 is a ubiquitously expressed multifunctional protein that is involved in U snRNP assembly, apoptosis, nuclear /cytoplasmic transportation, transcription, and RNAi pathways. Gemin4 is one of the core components of the Gemin-complex, which also contains survival motor neuron (SMN), the seven Gemin proteins (Gemin2–8), and Unrip. Mutations in the SMN1 gene cause the autosomal recessive disorder spinal muscular atrophy (SMA). Although the functions assigned to Gemin4 predominantly occur in the nucleus, the mechanisms that mediate the nuclear import of Gemin4 remain unclear. Here, using a novel panel of Gemin4 constructs we identify a canonical nuclear import sequence (NLS) in the N-terminus of Gemin4. The Gemin4 NLS is necessary and independently sufficient to mediate nuclear import of Gemin4. This is the first functional NLS identified within the SMN-Gemin complex.
PMCID: PMC3613997  PMID: 18675250
Gemin4; survival motor neuron; SMN; spinal muscular atrophy (SMA) nuclear localisation signal (NLS); import receptors
2.  Sex Differences in Response to Citalopram: A STAR*D Report 
Journal of psychiatric research  2008;43(5):503-511.
Controversy exists as to whether women with depression respond better to selective serotonin reuptake inhibitors (SSRIs) than men. The purpose of this report was to determine whether men and women differ in their responses to treatment with the SSRI citalopram using a large sample of real world patients from primary and psychiatric specialty care settings.
As part of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, 2876 participants were treated with citalopram for up to 12-14 weeks. Baseline demographic and clinical characteristics and outcomes were gathered and compared between men and women.
At baseline, women were younger, had more severe depressive symptoms and were more likely to have: early onset; previous suicide attempt(s); a family history of depression, alcohol abuse or drug abuse; atypical symptom features; and one or more of several concurrent psychiatric disorders. Despite greater baseline severity and more Axis I comorbidities, women were more likely to reach remission and response with citalopram than men.
Women have a better response to the SSRI citalopram than men, which may be due to sex-specific biological differences particularly in serotonergic systems.
PMCID: PMC2681489  PMID: 18752809
antidepressants; gender differences; estradiol; women's health; depression
3.  Effects of perceived control and cognitive coping on endocrine stress responses to pharmacological activation 
Biological psychiatry  2008;64(8):701-707.
The hypothalamic-pituitary adrenal (HPA) axis may mediate negative health effects of stress. It is sensitive to cognitive/emotional factors like novelty, perceived control and coping. Psychological intervention that reduces novelty, and enhances cognitive coping and sense of control can reduce cortisol responses to pentagastrin, a pharmacological HPA activator. This study attempted to identify the core factors that modulate HPA axis activity in this model.
Varying instructions were administered prior to drug exposure in a two-visit (placebo first) pentagastrin infusion paradigm. Healthy subjects (n=40) were randomly assigned to 1 of 4 instruction groups: (1) Standard instruction (SI); (2) Full cognitive intervention (CI); (3) The CI control component alone; or (4) The CI novelty reduction/coping components alone. Blood samples were obtained via intravenous catheter before and after pentagastrin.
Subjects receiving an intervention had smaller cortisol responses than subjects receiving standard instructions. “Coping” alone had as strong an impact as the more complex intervention that combined “coping” and “control.” “Control alone” also reduced cortisol but its HPA impact appeared less robust.
Brief psychological manipulation can significantly reduce HPA activation in challenge paradigms. Cognitive preparation that focused on side effects, reduced potential surprise and enhanced cognitive coping modulated HPA axis activity as effectively as a previously tested intervention that combined coping and control manipulations. A sense of control alone also reduced cortisol release. The results support development of “control” or “coping” techniques to combat negative health effects of stress that are mediated by HPA axis activation.
PMCID: PMC2579765  PMID: 18571624
stress; cortisol; pentagastrin; control; coping; anxiety
4.  Gender Differences in Depression Symptoms in Treatment-Seeking Adults: STAR*D Confirmatory Analyses 
Comprehensive psychiatry  2008;49(3):238-246.
While epidemiologic research consistently reports greater prevalence of major depressive disorder in women, small sample sizes in many studies do not allow for full elaboration of illness characteristics. This paper examines gender differences in terms of illness attributes in a cohort of 2541 outpatients from across the United States who enrolled in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study.
Confirmatory analyses were performed in 2541 outpatients comparing men and women with regard to socio-demographic features, comorbid Axis I and Axis III conditions, and illness characteristics. Results were compared to those of our previous report on the initial population of the first 1500 individuals enrolled in STAR*D.
In both samples, nearly two-thirds of the sample (62.5%) were women. Women had greater symptom severity, but men had more episodes of major depression, despite no difference in the length of illness. No differences in age of onset emerged. As in the first cohort, women showed greater rates of an anxiety disorder, bulimia and somatoform disorder, as well as more past suicide attempts, while men showed more alcohol and substance abuse. Women reported more appetite, weight, hypersomnia, interpersonal sensitivity, gastrointestinal and pain complaints, and less suicidal ideation. Irritability was equally common in men and women.
This large analysis confirmed most of the clinical features and co-morbidities found to be more prevalent in the first cohort of women. Additionally, this analysis corroborated previous research suggesting higher rates of atypical and anxious depression in women, but refuted the notion of an “irritable depression” found in men. The report confirmed the 1.7:1 ratio for depression seen across genders in the National Comorbidity Survey.
PMCID: PMC2759282  PMID: 18396182
Women; Depression; Prevalence; Gender
5.  Epidemiological Study Designs to Investigate Gene–Behavior Interactions in the Context of Human Obesity 
Obesity (Silver Spring, Md.)  2008;16(Suppl 3):S66-S71.
The epidemiology of obesity suggests that, for the majority of individuals, the disorder arises from an interaction between genetic predisposition and lifestyle behaviors such as dietary intake and physical activity. Unravelling the molecular basis of such interactions is complex but is becoming a realistic proposition as evidence emerges from whole genome association studies of genetic variants that are definitively associated with obesity. A range of possible study designs is available for investigating gene–lifestyle interaction, and the strengths and weaknesses of each approach are discussed in this article. Given the likely small main effect of common genetic variants and the difficulties in demonstrating associations of lifestyle factors with future risk of obesity, we would favor an analytical approach based on the clear specification of prior probabilities to reduce the likelihood of false discovery. Mixed approaches combining data from large-scale observational studies with smaller intervention trials may be ideal. In designing new studies to investigate these issues, a key choice is how precisely to quantify the important, but difficult to measure lifestyle behaviors. It is clear from power calculations that an approach based on enhancing precision of measurement of diet and physical activity is critical.
The high heritability of obesity coupled with the rapid increase in prevalence suggests that a combination of genetic and behavioral factors is critical to the etiology of obesity (1). It is easy to propose such a model for the development of obesity, but it is altogether much harder to identify the molecular mechanisms that underlie such a model. In this article, we review overall strategies and possible epidemiological study designs for investigating how genetic and behavioral risk factors combine to lead to excess weight gain.
PMCID: PMC2703295  PMID: 19037217
6.  HPA-Axis Hyperactivity and Mortality in Psychotic Depressive Disorder: Preliminary Findings 
Psychoneuroendocrinology  2008;33(5):654-658.
The excess mortality associated with depressive disorders has been most often attributed to risks for suicide but diverse findings indicate that depressive disorders also increase risks for cardiovascular (CV) mortality. Among the possible mediators is the HPA-axis hyperactivity that characterizes many cases of relatively severe depressive disorder and severity is characteristic of psychotic depressive disorder.
The following describes a 17-year mortality follow-up of 54 patients with Research Diagnostic Criteria (RDC) psychotic major depression or schizoaffective, mainly affective, depression. All had baseline assessments that included a 1mg dexamethasone suppression test with post-dexamethasone samples at 8 a.m., 4 p.m. and 11 p.m.
Regression analyses showed that both greater age and higher maximum post-dexamethasone cortisol concentrations predicted deaths due to cardiovascular (CV) causes (t = 4.01, p < .001 and t = 3.03, p = .004, respectively); the 11 p.m. cortisol concentration predicted death due to suicide (t = 2.05, p = 0.048). The 4 who died from CV disease had a mean (SD) post-dexamethasone cortisol concentration of 18.0 (6.0) μg/dl while the mean (SD) value for the remaining 50 patients was 7.6 (6.6) μg/dl (t = 3.03, df = 53, p = 0.004). Regression analyses showed the 11 p.m. post-dexamethasone value to be predictive of suicide (t = 2.05, p = 0.048).
Conclusions should be tentative because an earlier follow-up of a more heterogeneous, but larger, sample did not find a relationship between DST results and CV mortality, and because only 4 CV deaths occurred in the present study. HPA-axis hyperactivity is probably only one of a number of factors that link depressive disorder to CV mortality.
PMCID: PMC2435490  PMID: 18378097
7.  Human CHN1 mutations hyperactivate α2-chimaerin and cause Duane’s retraction syndrome 
Science (New York, N.Y.)  2008;321(5890):839-843.
The RacGAP molecule α2-chimaerin is implicated in neuronal signaling pathways required for precise guidance of developing corticospinal axons. We now demonstrate that a variant of Duane’s retraction syndrome, a congenital eye movement disorder in which affected individuals show aberrant development of axon projections to the extraocular muscles, can result from gain-of-function heterozygous missense mutations in CHN1 that increase α2-chimaerin RacGAP activity in vitro. A subset of mutations enhances α2-chimaerin membrane translocation and/or α2-chimaerin’s previously unrecognized ability to form a complex with itself. In ovo expression of mutant CHN1 alters the development of ocular motor axons. These data demonstrate that human CHN1 mutations can hyperactivate α2-chimaerin and result in aberrant cranial motor neuron development.
PMCID: PMC2593867  PMID: 18653847
8.  Socioeconomic position and risk of short-term weight gain: Prospective study of 14,619 middle-aged men and women 
BMC Public Health  2008;8:112.
The association between socioeconomic position in middle age and risk of subsequent, short-term weight gain is unknown. We therefore assessed this association in a prospective population based cohort study in Norfolk, UK.
We analysed data on 14,619 middle-aged men and women (aged between 40–75 at baseline) with repeated objective measures of weight and height at baseline (1993–1997) and follow up (1998–2000).
During follow up 5,064 people gained more than 2.5 kg. Compared with the highest social class, individuals in the lowest social class had around a 30% greater risk of gaining more than 2.5 kg (OR 1.29; 95% CI 1.11–1.51; p for trend = 0.002). This association remained statistically significant following adjustment for sex, age, baseline BMI, smoking, and follow up time (OR 1.25; CI 1.07–1.46; p for trend <0.001). We also found no material difference between unadjusted models and those including all confounders and potential mediators.
Individuals of low socioeconomic position are at greatest risk of gaining weight during middle age, which is not explained by classical correlates of socioeconomic position and risk factors for obesity.
PMCID: PMC2323377  PMID: 18400100

Results 1-8 (8)