Biomedical subjects

S Yen

Publications and source records attributed to S Yen.

At least 19 recordsLinked to original sources

PubMed2005

Avoidant personality disorder and social phobia: distinct enough to be separate disorders?

OBJECTIVE: Existing evidence from anxiety disorder research indicates that social phobics (SP) with avoidant personality disorder (AVPD) experience more anxiety and show more impairment than patients with SP alone. The purpose of this study was to examine whether in patients diagnosed with AVPD, the co-occurrence of SP adds to its severity. We hypothesized that the addition of SP will not add to the severity of AVPD alone. METHOD: Two groups of patients (AVPD=224; AVPD/SP=101) were compared at baseline and 2 years later on multiple demographic and clinical variables. RESULTS: Patients with AVPD and an additional diagnosis of SP differed little from patients with AVPD alone. CONCLUSION: These findings suggest that AVPD and SP may be alternative conceptualizations of the same disorder.

Adolescent↗

PubMed2004

Longitudinal diagnostic efficiency of DSM-IV criteria for obsessive-compulsive personality disorder: a 2-year prospective study.

OBJECTIVE: To examine the longitudinal diagnostic efficiency of the DSM-IV criteria for obsessive-compulsive personality disorder (OCPD). METHOD: At baseline, criteria and diagnoses were determined using diagnostic interviews, and blinded assessments were performed 24 months later with 550 participants. Diagnostic efficiency indices (conditional probabilities, total predictive power, and kappa) were calculated for each criterion determined at baseline, using the independent OCPD diagnosis at follow-up as the standard. RESULTS: Longitudinal diagnostic efficiencies for the OCPD criteria varied; findings suggested the overall predictive utility of 'preoccupied with details', 'rigid and stubborn', and 'reluctant to delegate'. CONCLUSION: These findings suggest the predictive validity of three cognitive-interpersonal OCPD criteria.

Adult↗

PubMed2004

Stressful life events as predictors of functioning: findings from the collaborative longitudinal personality disorders study.

OBJECTIVE: Although much attention has been given to the effects of adverse childhood experiences on the development of personality disorders (PDs), we know far less about how recent life events influence the ongoing course of functioning. We examined the extent to which PD subjects differ in rates of life events and the extent to which life events impact psychosocial functioning. METHOD: A total of 633 subjects were drawn from the Collaborative Longitudinal Personality Disorders Study (CLPS), a multi-site study of four personality disorders--schizotypal (STPD), borderline (BPD), avoidant (AVPD), obsessive-compulsive (OCPD)--and a comparison group of major depressive disorders (MDD) without PD. RESULTS: Borderline personality disorder subjects reported significantly more total negative life events than other PDs or subjects with MDD. Negative events, especially interpersonal events, predicted decreased psychosocial functioning over time. CONCLUSION: Our findings indicate higher rates of negative events in subjects with more severe PDs and suggest that negative life events adversely impact multiple areas of psychosocial functioning.

Adolescent↗

PubMed2003

Charge symmetry breaking in np-->dpi(0).

The forward-backward asymmetry in np-->dpi(0), which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2+/-8.0(stat)+/-5.5(syst)]x10(-4), at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.

Journal Article↗

PubMed2001

Recent developments in research of trauma and personality disorders.

Although the association between trauma and personality disorders, particularly borderline personality disorder (BPD), has been well established, the etiologic role of trauma in the development of personality disorders has been a topic of debate. Numerous mediation models have been put forth to explain how trauma can serve as a risk factor for the subsequent development of BPD. The symptomatic overlap between the proposed complex post-traumatic stress disorder diagnosis and BPD has fueled research efforts aimed at determining whether these are distinct disorders or should both be considered as trauma spectrum disorders. Treatment implications of this diagnostic differentiation are discussed.

Borderline Personality Disorder↗

PubMed2000

Missense tau mutations identified in FTDP-17 have a small effect on tau-microtubule interactions.

Frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) is a group of related disorders frequently characterized by the formation of tau inclusions in neurons and glial cells. To determine whether the formation of tau inclusions in FTDP-17 results from an alteration in the ability of mutant tau to maintain the microtubule (MT) system, we compared wild type four-repeat tau with three FTDP-17 mutants (P301L, V337M and R406W) for their ability to bind MT, promote MT assembly and bundling. According to in vitro binding and assembly assays, P301L is the only mutant that demonstrates a small, yet significant reduction, in its affinity for MT while both P301L and R406W have a small reduction in their ability to promote tubulin assembly. Based on studies of neuroblastoma and CHO cells transfected with GFP-tagged tau DNA constructs, both mutant and wild type tau transfectants were indistinguishable in the distribution pattern of tau in terms of co-localization with MT and generation of MT bundles. These results suggest that missense mutation of tau gene do not have an immediate impact on the integrity of MT system, and that exposure of affected neurons to additional insults or factors (e.g., aging) may be needed to initiate the formation of tau inclusions in FTDP-17.

Animals↗

PubMed2000

Evaluation of the Effect of Radiation Therapy to Nasopharyngeal Carcinoma by Positron Emission Tomography with 2-

Purpose: This investigation evaluated the effectiveness of positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose (PET-FDG) in assessing residual tumor or tumor recurrence in postradiation nasopharyngeal carcinoma (NPC) patients.Procedures: Forty-six patients with histologically proven NPC who received radiotherapy were included. PET-FDG images were analyzed by a semiquantitative method, metabolic ratio (tumor to cerebellum ratio).Results: The overall sensitivity and specificity of PET-FDG to detect residual tumors and recurrent lesions in the postradiation patients were 80% (12/15) and 87% (27/31), respectively. In patients with PET-FDG 6 months after radiation therapy, the sensitivity and specificity raised to 92% (11/12) and 100% (20/20), respectively.Conclusions: PET-FDG is effective in the evaluation of NPC treated with radiation. The optimal timing in assessing residual tumor or tumor recurrence in postradiation patients should be 6 months or later.

Journal Article↗

PubMed2000

Hostility in marital dyads: associations with depressive symptoms.

We examined the relations of hostility (of self and spouse) with self-ratings of depressive symptoms in 898 spouse pairs. Self-ratings of hostility were initially examined as predictors of depression. Next, spouse self-ratings of hostility were added to the model. Finally, the interaction of self x spouse hostility was investigated. These relations were explored for three components of hostility (Cynicism, Aggressive Responding, and Hostile Affect). Age and education were controlled in all models and effects were examined separately for women and men. Self-ratings of Hostile Affect were positively related to depressive symptoms for both women and men. Self-ratings of Cynicism were also significantly related to depression, but only for men. All three components of spouse's hostility were positively related to one's own symptoms of depression for women. For men, however, spouse's hostility was not related to symptoms of depression. These findings highlight the need to study psychosocial risk factors in social units and have potential implications for intervention.

Adult↗

PubMed2000

A cross-cultural comparison of depressive symptom manifestation: China and the United States.

This study compared depressive symptomatology among Chinese psychiatric outpatients versus the general Chinese population, and across 3 cultural groups--Chinese, Chinese American, and Caucasian American students--by use of the Center for Epidemiological Studies-Depression Scale (CES-D; L. S. Radloff, 1977) and the Chinese Depression Scale (N. Lin, 1989), translated from the CES-D. Results indicate that Chinese patients (n = 112) endorsed a higher proportion of somatic symptoms than nonpatients (n = 112). The intercultural comparison found that Chinese students (n = 98) had the lowest levels of somatic depressive symptom endorsement compared to both U.S. groups (n = 198). These findings seem to suggest that the tendency toward somatic symptom reporting is not any greater among Chinese populations but may be a function of having a mental illness or of help seeking in China.

Adult↗

PubMed2000

Sensitization of neuronal cells to oxidative stress with mutated human alpha-synuclein.

Linkage of alpha-synuclein (alpha-SN) mutations to familial Parkinson's disease (PD) and presence of alpha-SN as a major constituent of Lewy body in both sporadic and familial PD implicate alpha-SN abnormality in PD pathogenesis. Here we demonstrate that overexpression of wild-type or mutant alpha-SN does not cause any deleterious effect on the growth or continued propagation of transfected human cells, but overproduction of mutant alpha-SN heightens their sensitivity to menadione-induced oxidative injury. Such enhanced vulnerability is more pronounced in neuronal transfectants than in their nonneuronal counterparts and is associated with increased production of reactive oxygen species. The data suggest that mutated alpha-SN, especially with an alanine-to-proline substitution at residue 30, sensitizes neuronal cells to oxidative damage.

Cell Line↗

PubMed1999

FTDP-17 tau mutations decrease the susceptibility of tau to calpain I digestion.

Frontal temporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17) is caused by splice site and missense mutations in the tau gene, and characterized by the accumulation of filamentous tau in cerebral neurons and glia. The missense mutations reduce the ability of tau to promote microtubule assembly and increase the ability of tau to form filaments. In this report we demonstrate that mutants V337M and R406W are less susceptible than mutant P301L or corresponding wild type tau to degradation by calpain I. The differences were at least in part due to changes in accessibility of a cleavage site located about 100 amino acids off the carboxy-terminus. The results suggest that the pathogenesis of some forms of FTDP-17 may involve tau accumulation due to decreased proteolytic degradation.

Calpain↗

PubMed1999

Accelerated filament formation from tau protein with specific FTDP-17 missense mutations.

Tau is the major component of the neurofibrillar tangles that are a pathological hallmark of Alzheimers' disease. The identification of missense and splicing mutations in tau associated with the inherited frontotemporal dementia and Parkinsonism linked to chromosome 17 demonstrated that tau dysfunction can cause neurodegeneration. However, the mechanism by which tau dysfunction leads to neurodegeneration remains uncertain. Here, we present evidence that frontotemporal dementia and Parkinsonism linked to chromosome 17 missense mutations, P301L, V337M and R406W, cause an accelerated aggregation of tau into filaments. These results suggest one mechanism by which these mutations can cause neurodegeneration and frontotemporal dementia and Parkinsonism linked to chromosome 17.

Alzheimer Disease↗

PubMed1996