PubMed Health⌕ Search

Biomedical subjects

Debby W Tsuang

Publications and source records attributed to Debby W Tsuang.

11 recordsLinked to original sources
PubMed2006

The Consortium on the Genetics of Endophenotypes in Schizophrenia: model recruitment, assessment, and endophenotyping methods for a multisite collaboration.

BACKGROUND: The Consortium on the Genetics of Schizophrenia (COGS) is an ongoing, National Institute of Mental Health-funded, 7-site collaboration investigating the occurrence and genetic architecture of quantitative endophenotypes related to schizophrenia. The purpose of this article is to provide a description of the COGS structure and methods, including participant recruitment and assessment. METHODS: The hypothesis-driven recruitment strategy ascertains families that include a proband with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of schizophrenia, and at least one unaffected full sibling available for genotyping and endophenotyping, along with parents available for genotyping and (optional depending on age) endophenotyping. The family structure is selected to provide contrast in quantitative endophenotypic traits and thus to maximize the power of the planned genetic analyses. Probands are recruited from many sources including clinician referrals, local National Alliance for the Mentally Ill chapters, and advertising via the media. All participants undergo a standardized protocol that includes clinical characterization, a blood draw for genotyping, and endophenotype assessments (P50 suppression, prepulse inhibition, antisaccade performance, continuous performance tasks, letter-number span, verbal memory, and a computerized neurocognitive battery). Investigators participate in weekly teleconferences to coordinate and evaluate recruitment, clinical assessment, endophenotyping, and continuous quality control of data gathering and analyses. Data integrity is maintained through use of a highly quality-assured, centralized web-based database. RESULTS: As of February 2006, 355 families have been enrolled and 688 participants have been endophenotyped, including schizophrenia probands (n = 154, M:F = 110:44), first-degree biological relatives (n = 343, M:F = 151:192), and community comparison subjects (n = 191, M:F = 81:110). DISCUSSION: Successful multisite genetics collaborations must institute standardized methodological criteria for assessment and recruitment that are clearly defined, well communicated, and uniformly applied. In parallel, studies utilizing endophenotypes require strict adherence to criteria for cross-site data acquisition, equipment calibration and testing and software equivalence, and continuous quality assurance for many measures obtained across sites. This report describes methods and presents the structure of the COGS as a model of multisite endophenotype genetic studies. It also provides demographic information after the first 2 years of data collection on a sample for whom the behavioral data and genetics of endophenotype performance will be fully characterized in future articles. Some issues discussed in the reviews that follow reflect the challenges of evaluating endophenotypes in studies of the genetic architecture of endophenotypes in schizophrenia.

Cooperative Behavior↗
PubMed2006

Successful multi-site measurement of antisaccade performance deficits in schizophrenia.

The antisaccade task is a promising schizophrenia endophenotype; it is stable over time and reflects neurophysiological deficits present in both schizophrenia subjects and their first-degree relatives. Meaningful genetic research requires large sample sizes that are best ascertained using multi-site study designs. To establish the criterion validity of the antisaccade task in a multi-site design, the Consortium on the Genetics of Schizophrenia (COGS) examined whether seven sites could detect previously reported antisaccade deficits in schizophrenia subjects. Investigators presented 3 blocks of 20 antisaccade stimuli to 143 schizophrenia subjects and 195 comparison subjects. Frequent collaborator communication, standardized training, and ongoing quality assurance optimized testing uniformity. Data were discarded from only 1.2% of subjects due to poor quality, reflecting the high fidelity of data collection and scoring methods. All sites detected a significant difference in the proportion of correct antisaccades between schizophrenia and comparison subjects (p<.02 at all sites); group differences in gain and latency were less robust. Regression analyses to adjust for the effects of group, site, age, gender, smoking, and parental education on the proportion of correct antisaccades revealed a significant effect of group, site, and age but no effect of gender, smoking, or parental education, and no group-by-site interactions. Intraclass correlations between proportion of correct antisaccades across the blocks of stimuli ranged from 0.87 to 0.93, demonstrating good within-session reliability at sites. These results confirm previous findings of antisaccade deficits in schizophrenia subjects and support the use of the antisaccade task as a potential schizophrenia endophenotype in multi-site genetic studies.

Adolescent↗
PubMed2006

Lewy body pathology in late-onset familial Alzheimer's disease: a clinicopathological case series.

BACKGROUND: Lewy body pathology (LBP) is a common finding in Alzheimer's disease (AD), but the pathophysiology for this coexistent pathology remains unclear. METHODS: We ascertained late-onset dementia (mean age > 60 years old) families with at least 3 autopsies. We then conducted systematic alpha-synuclein (SNCA) immunostaining to determine the frequency and distribution of LBP in families with late-onset AD. RESULTS: All 32 subjects met NIA-Reagan neuropathological criteria for "high likelihood" of having AD. Hematoxylin and eosin staining detected LBP in the substantia nigra (SN) in 8 (25%) individuals. SNCA immunostaining detected LBP in 21 individuals (66%). While all subjects with SN LBP had co-existent amygdala LBP, many (9/21, 43%) of the cases with amygdala LBP did not have coexistent SN LBP (McNemar's chi-square test, p=0.008). Each family had at least two cases with LBP, but no family had LBP in all autopsied cases. CONCLUSIONS: Presence of significant AD pathology in one family member was highly predictive of similar pathology in other family members. However, despite the use of more sensitive SNCA immunohistochemistry, the presence of LBP was variable within all 7 families. Consistent with previous studies in sporadic and familial AD, the amygdala appeared to be the most vulnerable region for LBP in AD. Additional clinical, neuropathologic, and genetic studies are necessary to determine the clinical and pathological significance of LBP in AD.

Age of Onset↗
PubMed2005

Salivary cortisol and memory function in human aging.

OBJECTIVE: To examine the association of salivary cortisol with cognitive changes in a 3 year longitudinal study. Previous studies have suggested that elevated glucocorticoid concentrations alter hippocampal neuronal morphology, inhibit neurogenesis, and impair cognition. METHODS: Salivary cortisol samples were collected at home by 79 cognitively intact older persons (mean age 78+/-7 years) at 08:00, 15:00 and 23:00h, and collections were repeated annually for 3 years. Cognitive function was also assessed annually. RESULTS: The mean cortisol level of samples taken at three times of day and the cortisol concentration at 23:00h were significantly associated with poorer performance on tasks of declarative memory and executive function. Of 46 subjects who completed the entire 3 year study, higher initial cortisol concentration at 23:00h predicted a decline in performance of delayed paragraph recall. CONCLUSION: These results partially confirm previous findings that high cortisol is associated with impaired declarative memory function in non-demented older persons. In addition, our data show that high salivary cortisol concentrations predict a decline in memory function over the next 3 years.

Aged↗
PubMed2003

Familial dementia with Lewy bodies with an atypical clinical presentation.

The authors report a case of a 64-year-old male with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) pathology at autopsy who did not manifest the core symptoms of DLB until very late in his clinical course. His initial presentation of early executive and language dysfunction suggested a cortical dementia similar to frontotemporal lobar degeneration (FTLD). Core symptoms of DLB including dementia, hallucination, and parkinsonian symptoms were not apparent until late in the course of his illness. Autopsy revealed both brainstem and cortical Lewy bodies and AD pathology. Family history revealed 7 relatives with a history of dementia including 4 with possible or probable DLB. This case is unique because of the FTLD-like presentation, positive family history of dementia, and autopsy confirmation of DLB.

Alzheimer Disease↗
PubMed2002

Linkage of chromosome 13q32 to schizophrenia in a large veterans affairs cooperative study sample.

Several prior reports have suggested that chromosomal region 13q32 may harbor a schizophrenia susceptibility gene. In an attempt to replicate this finding, we assessed linkage between chromosome 13 markers and schizophrenia in 166 families, each with two or more affected members. The families, assembled from multiple centers by the Department of Veterans Affairs Cooperative Studies Program, included 392 sampled affected subjects and 216 affected sib pairs. By DSM-III-R criteria, 360 subjects (91.8%) had a diagnosis of schizophrenia and 32 (8.2%) were classified as schizoaffective disorder, depressed. The families had mixed ethnic backgrounds. The majority were northern European-American families (n = 62, 37%), but a substantial proportion were African-American kindreds (n = 60, 36%). Chromosome 13 markers, spaced at intervals of approximately 10 cM over the entire chromosome and 2-5 cM for the 13q32 region were genotyped and the data analyzed using semi-parametric affected only linkage analysis. For the combined sample (with race broadly defined and schizophrenia narrowly defined) the maximum LOD score was 1.43 (Z-score of 2.57; P = 0.01) at 79.0 cM between markers D13S1241 (76.3 cM) and D13S159 (79.5 cM). Both ethnic groups showed a peak in this region. The peak is within 3 cM of the peak reported by Brzustowicz et al. [1999: Am J Hum Genet 65:1096-1103].

Adult↗
PubMed2002

Familial dementia with lewy bodies: a clinical and neuropathological study of 2 families.

BACKGROUND: Dementia with Lewy bodies (DLB) is characterized by early dementia and associated visual hallucinations, parkinsonism, and fluctuations in cognition. Few families with DLB have been described with detailed clinical, pathological, and genetic assessments. OBJECTIVE: To investigate the clinical, neuropathological, and genetic characteristics of families with 2 or more autopsy-proven cases of DLB. DESIGN: Consecutive cases with the neuropathological diagnosis of DLB were reviewed as part of a case series. Families included in this study have 2 or more autopsy-proven cases of DLB available and a positive family history of dementia. We obtained clinical and neuropathological data on all first-degree relatives. Neuropathological evaluations included alpha-synuclein immunostaining for Lewy body detection. We conducted apolipoprotein E genotyping and sequenced the alpha-, beta-, gamma-synuclein, and parkin genes. SETTING: Subjects were selected from the neuropathology core of the University of Washington's Alzheimer's Disease Research Center. PATIENTS: The study investigated 2 families. Clinical information was obtained from 10 individuals in family 1 and 7 individuals in family 2. Neuropathological examinations were conducted in 3 individuals in family 1 and 2 individuals in family 2. MAIN OUTCOME MEASURES: Each subject was examined for the presence of clinical symptoms and neuropathological findings consistent with DLB. RESULTS: While all affected individuals presented with dementia in both families, only individuals in family 1 developed visual hallucinations and delusions. Parkinsonism, if present, occurred later in the course of illness. Neuropathological examination revealed Lewy bodies in all patients, while 1 patient from each family also met the neuropathological criteria for Alzheimer disease. All affected individuals carried at least 1 APOE (apolipoprotein E) epsilon 4 allele, while there were no nucleotide alterations in the synuclein or parkin genes. CONCLUSIONS: Familial DLB exists, although there is substantial clinical and neuropathological heterogeneity within and between families. Additional clinicopathologic and genetic studies are necessary to further our understanding of DLB.

Aged↗
PubMed2002

Genetics of dementia.

Many neurodegenerative diseases are exceedingly complex disorders (Fig. 6). In the past decade, we have made tremendous advances in our understanding [figure: see text] of the genetic basis of these disorders. One common characteristic of these disorders is the existence of rare families in which a given disease is inherited as a Mendelian trait. In this article, we have reviewed the genetics of several common neurodegenerative disorders that are associated with cognitive disturbances and for which causative genes have been identified. Further genetic analysis should clarify the roles of known genes in the pathogenesis of common sporadic forms of these various diseases. Investigation of the normal and aberrant functions of these genes should provide insight into the underlying mechanisms of these disorders. Such research should facilitate new strategies for therapeutic interventions. Although molecular genetics has helped to clarify the etiology of these disorders, clinicians have played a critical role in the careful identification and classification of many families who were involved in the eventual mapping and cloning of causative mutations. The role of the clinician should not be underestimated. Future clinical and molecular genetics findings hold many clinical implications. It is likely that new diagnostic and therapeutic strategies for dementing disorders are just on the horizon.

Adult↗
PubMedDate not supplied

Propranolol for disruptive behaviors in nursing home residents with probable or possible Alzheimer disease: a placebo-controlled study.

OBJECTIVE: Enhanced behavioral responsiveness to central nervous system (CNS) norepinephrine (NE) in Alzheimer disease (AD) may contribute to the pathophysiology of disruptive behaviors such as aggression, uncooperativeness with necessary care, irritability, and pressured pacing. We evaluated the efficacy of the beta-adrenergic antagonist propranolol for treatment-resistant disruptive behaviors and overall behavioral status in nursing home residents with probable or possible AD. METHODS: Thirty-one subjects (age 85 +/- 8 [SD]) with probable or possible AD and persistent disruptive behaviors that interfered with necessary care were randomized to propranolol (n = 17) or placebo (n = 14) in a double-blind study. Stable doses of previously prescribed psychotropics were maintained at pre-study dose during the study. Following a propranolol or placebo dose titration period of up to 9 days (per a dosing algorithm), subjects were maintained on maximum achieved dose for 6 weeks. Primary outcome measures were the Neuropsychiatric Inventory (NPI) and the Clinical Global Impression of Change (CGIC). RESULTS: Propranolol augmentation (mean achieved dose 106 +/- 38 mg/d) was significantly more effective than placebo for improving overall behavioral status on the total NPI score and CGIC. Improvement in individual NPI items within propranolol subjects was significant only for "agitation/aggression" and "anxiety," and reached borderline statistical significance favoring propranolol over placebo only for "agitation/aggression." Pressured pacing and irritability did not appear responsive to propranolol. In propranolol subjects rated "moderately improved" or "markedly improved" on the CGIC at the end of the double-blind study phase, improvement of overall behavioral status had diminished substantially after 6 months of open-label propranolol treatment. CONCLUSION: Short-term propranolol augmentation treatment appeared modestly effective and well tolerated for overall behavioral status in nursing home residents with probable or possible AD complicated by disruptive behaviors. Propranolol may be helpful specifically for aggression and uncooperativeness (the behaviors assessed by the NPI "agitation/aggressiveness" item). However, the usefulness of propranolol in this very old and frail population was limited by the high frequency of relative contraindications to beta-adrenergic antagonist treatment and diminution of initial behavioral improvements over time.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Familial occurrence of dementia with Lewy bodies.

OBJECTIVE: The authors investigated the validity of the designation "familial dementia with Lewy bodies (DLB)" by evaluating the clinical, neuropathological, and genetic characteristics of previously reported families exhibiting both familial parkinsonism and dementia. METHODS: Several families, including multiple individuals with parkinsonism as well as prominent dementia, were identified through a literature search. Selected families had at least one member with dementia with autopsy evidence of neocortical and/or limbic Lewy-body (LB) pathology. Clinical and neuropathological evidence from reports of families with prominent dementia as well as parkinsonism was reviewed to further define familial DLB. RESULTS: All selected families had at least one affected individual with dementia and autopsy-proven DLB. Therefore, these families might be considered examples of familial DLB. Individuals in the first six families typically presented with parkinsonian features, whereas cognitive decline did not appear until years later. In contrast, in the other six families, affected individuals typically presented with cognitive decline, and parkinsonism developed later. CONCLUSIONS: Families exist in which one or more persons meet both clinical and neuropathological criteria for DLB. They differ as to whether the signs of parkinsonism precede or follow signs of dementia. It remains to be determined whether this clinical distinction is biologically important. Susceptibility to developing LB pathology may be determined by the interaction between genetic predisposition and environmental risk factors.

Brain↗