Browsing by Subject "Age Factors"
Now showing 1 - 20 of 178
- Results Per Page
- Sort Options
Item Open Access A cohort study of 4,190 patients treated with low-intensity pulsed ultrasound (LIPUS): findings in the elderly versus all patients.(BMC Musculoskelet Disord, 2015-03-01) Zura, Robert; Mehta, Samir; Rocca, Gregory J Della; Jones, John; Steen, R GrantBACKGROUND: Patient age is one of many potential risk factors for fracture nonunion. Our hypothesis is that older patients (≥ 60) with fracture risk factors treated with low-intensity pulsed ultrasound (LIPUS) have similar heal rate (HR) to the population as a whole. We evaluate the impact of age in conjunction with other risk factors on HR in LIPUS-treated patients with fresh fracture (≤ 90 days old). METHODS: The Exogen Bone Healing System is a LIPUS device approved in 1994 to accelerate healing of fresh fracture. After approval, the FDA required a Post-Market Registry to assess performance. Patient data collected from October 1994 until October 1998 were individually reviewed and validated by a registered nurse. Four distinct data elements were required to report a patient: date fracture occurred; date treatment began; date treatment ended; and a dichotomous outcome of healed v. failed, by clinical and radiological criteria. Data were used to calculate two derived variables; days to treatment (DTT) and days on treatment (DOT). Every validated fresh fracture patient with DTT, DOT, and outcome is reported. RESULTS: The validated registry had 5,765 patients with fresh fracture; 73% (N = 4,190) are reported, while 13% of patients were lost to follow-up, 11% withdrew or were non-compliant, and 3% died or are missing outcome. Among treatment-compliant patients, HR was 96.2%. Logistic estimates of the odds ratio for healing are equivalent for patients age 30 to 79 years and all age cohorts had a HR > 94%. Open fracture, current smoking, diabetes, vascular insufficiency, osteoporosis, cancer, rheumatoid arthritis, and prescription NSAIDs all reduced HR, but older patients (≥ 60) had similar HRs to the population as a whole. DTT was significantly shorter for patients who healed (p < 0.0001). CONCLUSIONS: Comorbid conditions in conjunction with aging can reduce fracture HR. Patients with fracture who used LIPUS had a 96% HR, whereas the expected HR averages 93%. Time to treatment was significantly shorter among patients who healed (p < 0.0001), suggesting that it is beneficial to begin LIPUS treatment early. Older patients (≥ 60) with fracture risk factors treated with LIPUS exhibit similar heal rates to the population as a whole.Item Open Access A dimensional approach to understanding severity estimates and risk correlates of marijuana abuse and dependence in adults.(International journal of methods in psychiatric research, 2012-06) Wu, Li-Tzy; Woody, George E; Yang, Chongming; Pan, Jeng-Jong; Reeve, Bryce B; Blazer, Dan GWhile item response theory (IRT) research shows a latent severity trait underlying response patterns of substance abuse and dependence symptoms, little is known about IRT-based severity estimates in relation to clinically relevant measures. In response to increased prevalences of marijuana-related treatment admissions, an elevated level of marijuana potency, and the debate on medical marijuana use, we applied dimensional approaches to understand IRT-based severity estimates for marijuana use disorders (MUDs) and their correlates while simultaneously considering gender- and race/ethnicity-related differential item functioning (DIF). Using adult data from the 2008 National Survey on Drug Use and Health (N = 37,897), Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for MUDs among past-year marijuana users were examined by IRT, logistic regression, and multiple indicators-multiple causes (MIMIC) approaches. Among 6917 marijuana users, 15% met criteria for a MUD; another 24% exhibited subthreshold dependence. Abuse criteria were highly correlated with dependence criteria (correlation = 0.90), indicating unidimensionality; item information curves revealed redundancy in multiple criteria. MIMIC analyses showed that MUD criteria were positively associated with weekly marijuana use, early marijuana use, other substance use disorders, substance abuse treatment, and serious psychological distress. African Americans and Hispanics showed higher levels of MUDs than Whites, even after adjusting for race/ethnicity-related DIF. The redundancy in multiple criteria suggests an opportunity to improve efficiency in measuring symptom-level manifestations by removing low-informative criteria. Elevated rates of MUDs among African Americans and Hispanics require research to elucidate risk factors and improve assessments of MUDs for different racial/ethnic groups.Item Open Access A Longitudinal Cohort Study of Malaria Exposure and Changing Serostatus in a Malaria Endemic Area of Rural Tanzania(Malaria Journal, 2017-08-02) Simmons, RA; Mboera, L; Stresman, A; Turner, E; Kramer, R; Drakeley, C; O'Meara, WPBackground
Measurements of anti-malarial antibodies are increasingly used as a proxy of transmission intensity. Most serological surveys are based on the use of cross-sectional data that, when age-stratified, approximates historical patterns of transmission within a population. Comparatively few studies leverage longitudinal data to explicitly relate individual infection events with subsequent antibody responses.Methods
The occurrence of seroconversion and seroreversion events for two Plasmodium falciparum asexual stage antigens (MSP-1 and AMA-1) was examined using three annual measurements of 691 individuals from a cohort of individuals in a malaria-endemic area of rural east-central Tanzania. Mixed-effect logistic regression models were employed to determine factors associated with changes in serostatus over time.Results
While the expected population-level relationship between seroprevalence and disease incidence was observed, on an individual level the relationship between individual infections and the antibody response was complex. MSP-1 antibody responses were more dynamic in response to the occurrence and resolution of infection events than AMA-1, while the latter was more correlated with consecutive infections. The MSP-1 antibody response to an observed infection seemed to decay faster over time than the corresponding AMA-1 response. Surprisingly, there was no evidence of an age effect on the occurrence of a conversion or reversion event.Conclusions
While the population-level results concur with previously published sero-epidemiological surveys, the individual-level results highlight the more complex relationship between detected infections and antibody dynamics than can be analysed using cross-sectional data. The longitudinal analysis of serological data may provide a powerful tool for teasing apart the complex relationship between infection events and the corresponding immune response, thereby improving the ability to rapidly assess the success or failure of malaria control programmes.Item Open Access A meta-analysis of four genome-wide association studies of survival to age 90 years or older: the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium.(J Gerontol A Biol Sci Med Sci, 2010-05) Newman, Anne B; Walter, Stefan; Lunetta, Kathryn L; Garcia, Melissa E; Slagboom, P Eline; Christensen, Kaare; Arnold, Alice M; Aspelund, Thor; Aulchenko, Yurii S; Benjamin, Emelia J; Christiansen, Lene; D'Agostino, Ralph B; Fitzpatrick, Annette L; Franceschini, Nora; Glazer, Nicole L; Gudnason, Vilmundur; Hofman, Albert; Kaplan, Robert; Karasik, David; Kelly-Hayes, Margaret; Kiel, Douglas P; Launer, Lenore J; Marciante, Kristin D; Massaro, Joseph M; Miljkovic, Iva; Nalls, Michael A; Hernandez, Dena; Psaty, Bruce M; Rivadeneira, Fernando; Rotter, Jerome; Seshadri, Sudha; Smith, Albert V; Taylor, Kent D; Tiemeier, Henning; Uh, Hae-Won; Uitterlinden, André G; Vaupel, James W; Walston, Jeremy; Westendorp, Rudi GJ; Harris, Tamara B; Lumley, Thomas; van Duijn, Cornelia M; Murabito, Joanne MBACKGROUND: Genome-wide association studies (GWAS) may yield insights into longevity. METHODS: We performed a meta-analysis of GWAS in Caucasians from four prospective cohort studies: the Age, Gene/Environment Susceptibility-Reykjavik Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Rotterdam Study participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Longevity was defined as survival to age 90 years or older (n = 1,836); the comparison group comprised cohort members who died between the ages of 55 and 80 years (n = 1,955). In a second discovery stage, additional genotyping was conducted in the Leiden Longevity Study cohort and the Danish 1905 cohort. RESULTS: There were 273 single-nucleotide polymorphism (SNP) associations with p < .0001, but none reached the prespecified significance level of 5 x 10(-8). Of the most significant SNPs, 24 were independent signals, and 16 of these SNPs were successfully genotyped in the second discovery stage, with one association for rs9664222, reaching 6.77 x 10(-7) for the combined meta-analysis of CHARGE and the stage 2 cohorts. The SNP lies in a region near MINPP1 (chromosome 10), a well-conserved gene involved in regulation of cellular proliferation. The minor allele was associated with lower odds of survival past age 90 (odds ratio = 0.82). Associations of interest in a homologue of the longevity assurance gene (LASS3) and PAPPA2 were not strengthened in the second stage. CONCLUSION: Survival studies of larger size or more extreme or specific phenotypes may support or refine these initial findings.Item Open Access Accelerated epigenetic age as a biomarker of cardiovascular sensitivity to traffic-related air pollution.(Aging, 2020-12) Ward-Caviness, Cavin K; Russell, Armistead G; Weaver, Anne M; Slawsky, Erik; Dhingra, Radhika; Kwee, Lydia Coulter; Jiang, Rong; Neas, Lucas M; Diaz-Sanchez, David; Devlin, Robert B; Cascio, Wayne E; Olden, Kenneth; Hauser, Elizabeth R; Shah, Svati H; Kraus, William EBackground
Accelerated epigenetic age has been proposed as a biomarker of increased aging, which may indicate disruptions in cellular and organ system homeostasis and thus contribute to sensitivity to environmental exposures.Methods
Using 497 participants from the CATHGEN cohort, we evaluated whether accelerated epigenetic aging increases cardiovascular sensitivity to traffic-related air pollution (TRAP) exposure. We used residential proximity to major roadways and source apportioned air pollution models as measures of TRAP exposure, and chose peripheral arterial disease (PAD) and blood pressure as outcomes based on previous associations with TRAP. We used Horvath epigenetic age acceleration (AAD) and phenotypic age acceleration (PhenoAAD) as measures of age acceleration, and adjusted all models for chronological age, race, sex, smoking, and socioeconomic status.Results
We observed significant interactions between TRAP and both AAD and PhenoAAD. Interactions indicated that increased epigenetic age acceleration elevated associations between proximity to roadways and PAD. Interactions were also observed between AAD and gasoline and diesel source apportioned PM2.5.Conclusion
Epigenetic age acceleration may be a biomarker of sensitivity to air pollution, particularly for TRAP in urban cohorts. This presents a novel means by which to understand sensitivity to air pollution and provides a molecular measure of environmental sensitivity.Item Open Access Aerobic exercise and neurocognitive performance: a meta-analytic review of randomized controlled trials.(Psychosom Med, 2010-04) Smith, Patrick J; Blumenthal, James A; Hoffman, Benson M; Cooper, Harris; Strauman, Timothy A; Welsh-Bohmer, Kathleen; Browndyke, Jeffrey N; Sherwood, AndrewOBJECTIVES: To assess the effects of aerobic exercise training on neurocognitive performance. Although the effects of exercise on neurocognition have been the subject of several previous reviews and meta-analyses, they have been hampered by methodological shortcomings and are now outdated as a result of the recent publication of several large-scale, randomized, controlled trials (RCTs). METHODS: We conducted a systematic literature review of RCTs examining the association between aerobic exercise training on neurocognitive performance between January 1966 and July 2009. Suitable studies were selected for inclusion according to the following criteria: randomized treatment allocation; mean age > or =18 years of age; duration of treatment >1 month; incorporated aerobic exercise components; supervised exercise training; the presence of a nonaerobic-exercise control group; and sufficient information to derive effect size data. RESULTS: Twenty-nine studies met inclusion criteria and were included in our analyses, representing data from 2049 participants and 234 effect sizes. Individuals randomly assigned to receive aerobic exercise training demonstrated modest improvements in attention and processing speed (g = 0.158; 95% confidence interval [CI]; 0.055-0.260; p = .003), executive function (g = 0.123; 95% CI, 0.021-0.225; p = .018), and memory (g = 0.128; 95% CI, 0.015-0.241; p = .026). CONCLUSIONS: Aerobic exercise training is associated with modest improvements in attention and processing speed, executive function, and memory, although the effects of exercise on working memory are less consistent. Rigorous RCTs are needed with larger samples, appropriate controls, and longer follow-up periods.Item Open Access Age mediation of frontoparietal activation during visual feature search.(Neuroimage, 2014-11-15) Madden, David J; Parks, Emily L; Davis, Simon W; Diaz, Michele T; Potter, Guy G; Chou, Ying-hui; Chen, Nan-kuei; Cabeza, RobertoActivation of frontal and parietal brain regions is associated with attentional control during visual search. We used fMRI to characterize age-related differences in frontoparietal activation in a highly efficient feature search task, detection of a shape singleton. On half of the trials, a salient distractor (a color singleton) was present in the display. The hypothesis was that frontoparietal activation mediated the relation between age and attentional capture by the salient distractor. Participants were healthy, community-dwelling individuals, 21 younger adults (19-29 years of age) and 21 older adults (60-87 years of age). Top-down attention, in the form of target predictability, was associated with an improvement in search performance that was comparable for younger and older adults. The increase in search reaction time (RT) associated with the salient distractor (attentional capture), standardized to correct for generalized age-related slowing, was greater for older adults than for younger adults. On trials with a color singleton distractor, search RT increased as a function of increasing activation in frontal regions, for both age groups combined, suggesting increased task difficulty. Mediational analyses disconfirmed the hypothesized model, in which frontal activation mediated the age-related increase in attentional capture, but supported an alternative model in which age was a mediator of the relation between frontal activation and capture.Item Open Access Age of first drunkenness and risks for all-cause mortality: A 27-year follow-up from the epidemiologic catchment area study.(Drug and alcohol dependence, 2017-07) Hu, Hui; Eaton, William W; Anthony, James C; Wu, Li-Tzy; Cottler, Linda BEarly-onset drunkenness is associated with an increased risk of developing an alcohol use disorder (AUD), which predicts excess mortality risk. Here, we estimated mortality risk for drinkers with and without early drunkenness.For 14,848 adult participants interviewed about drinking, drunken episodes, and AUD in 1981-83 for the Epidemiologic Catchment Area in New Haven (Connecticut), Baltimore (Maryland), St. Louis (Missouri), and Durham (North Carolina), we linked National Death Index records through 2007.Cox regression modeling estimates showed excess mortality for drinkers with age of first drunkenness earlier than 15 years old (hazard ratio, HR: 1.47, 95% CI: 1.25, 1.72) and when first drunkenness occurred at or after age 15 (HR: 1.20, 95% CI: 1.11, 1.29), as compared with adults who had never been drunk. Consistent results were observed, irrespective of AUD history. That is, early drunkenness signaled excess mortality risk even in absence of AUD.In a large community sample from four cities in the US, early age of onset of drunkenness predicts mortality risk. We discuss experiments to investigate the possible causal significance of this predictive association.Item Unknown Age patterns of incidence of geriatric disease in the U.S. elderly population: Medicare-based analysis.(J Am Geriatr Soc, 2012-02) Akushevich, Igor; Kravchenko, Julia; Ukraintseva, Svetlana; Arbeev, Konstantin; Yashin, Anatoliy IOBJECTIVES: To use the Medicare Files of Service Use (MFSU) to evaluate patterns in the incidence of aging-related diseases in the U.S. elderly population. DESIGN: Age-specific incidence rates of 19 aging-related diseases were evaluated using the National Long Term Care Survey (NLTCS) and the Surveillance, Epidemiology, and End Results (SEER) Registry data, both linked to MFSU (NLTCS-M and SEER-M, respectively), using an algorithm developed for individual date at onset evaluation. SETTING: A random sample from the entire U.S. elderly population (Medicare beneficiaries) was used in NLTCS, and the SEER Registry data covers 26% of the U.S. population. PARTICIPANTS: Thirty-four thousand seventy-seven individuals from NLTCS-M and 2,154,598 from SEER-M. MEASUREMENTS: Individual medical histories were reconstructed using information on diagnoses coded in MFSU, dates of medical services and procedures, and Medicare enrollment and disenrollment. RESULTS: The majority of diseases (e.g., prostate cancer, asthma, and diabetes mellitus) had a monotonic decline (or decline after a short period of increase) in incidence with age. A monotonic increase in incidence with age with a subsequent leveling off and decline was observed for myocardial infarction, stroke, heart failure, ulcer, and Alzheimer's disease. An inverted U-shaped age pattern was detected for lung and colon carcinomas, Parkinson's disease, and renal failure. The results obtained from the NLTCS-M and SEER-M were in agreement (excluding an excess for circulatory diseases in the NLTCS-M). A sensitivity analysis proved the stability of the incidence rates evaluated. CONCLUSION: The developed computational approaches applied to the nationally representative Medicare-based data sets allow reconstruction of age patterns of disease incidence in the U.S. elderly population at the national level with unprecedented statistical accuracy and stability with respect to systematic biases.Item Unknown Age, gender, and cancer but not neurodegenerative and cardiovascular diseases strongly modulate systemic effect of the Apolipoprotein E4 allele on lifespan.(PLoS Genet, 2014-01) Kulminski, Alexander M; Arbeev, Konstantin G; Culminskaya, Irina; Arbeeva, Liubov; Ukraintseva, Svetlana V; Stallard, Eric; Christensen, Kaare; Schupf, Nicole; Province, Michael A; Yashin, Anatoli IEnduring interest in the Apolipoprotein E (ApoE) polymorphism is ensured by its evolutionary-driven uniqueness in humans and its prominent role in geriatrics and gerontology. We use large samples of longitudinally followed populations from the Framingham Heart Study (FHS) original and offspring cohorts and the Long Life Family Study (LLFS) to investigate gender-specific effects of the ApoE4 allele on human survival in a wide range of ages from midlife to extreme old ages, and the sensitivity of these effects to cardiovascular disease (CVD), cancer, and neurodegenerative disorders (ND). The analyses show that women's lifespan is more sensitive to the e4 allele than men's in all these populations. A highly significant adverse effect of the e4 allele is limited to women with moderate lifespan of about 70 to 95 years in two FHS cohorts and the LLFS with relative risk of death RR = 1.48 (p = 3.6 × 10(-6)) in the FHS cohorts. Major human diseases including CVD, ND, and cancer, whose risks can be sensitive to the e4 allele, do not mediate the association of this allele with lifespan in large FHS samples. Non-skin cancer non-additively increases mortality of the FHS women with moderate lifespans increasing the risks of death of the e4 carriers with cancer two-fold compared to the non-e4 carriers, i.e., RR = 2.07 (p = 5.0 × 10(-7)). The results suggest a pivotal role of non-sex-specific cancer as a nonlinear modulator of survival in this sample that increases the risk of death of the ApoE4 carriers by 150% (p = 5.3 × 10(-8)) compared to the non-carriers. This risk explains the 4.2 year shorter life expectancy of the e4 carriers compared to the non-carriers in this sample. The analyses suggest the existence of age- and gender-sensitive systemic mechanisms linking the e4 allele to lifespan which can non-additively interfere with cancer-related mechanisms.Item Open Access Age-related differences in the neural bases of phonological and semantic processes in the context of task-irrelevant information.(Cognitive, affective & behavioral neuroscience, 2019-08) Diaz, Michele T; Johnson, Micah A; Burke, Deborah M; Truong, Trong-Kha; Madden, David JAs we age we have increasing difficulty with phonological aspects of language production. Yet semantic processes are largely stable across the life span. This suggests a fundamental difference in the cognitive and potentially neural architecture supporting these systems. Moreover, language processes such as these interact with other cognitive processes that also show age-related decline, such as executive function and inhibition. The present study examined phonological and semantic processes in the presence of task-irrelevant information to examine the influence of such material on language production. Older and younger adults made phonological and semantic decisions about pictures in the presence of either phonologically or semantically related words, which were unrelated to the task. FMRI activation during the semantic condition showed that all adults engaged typical left-hemisphere language regions, and that this activation was positively correlated with efficiency across all adults. In contrast, the phonological condition elicited activation in bilateral precuneus and cingulate, with no clear brain-behavior relationship. Similarly, older adults exhibited greater activation than younger adults in several regions that were unrelated to behavioral performance. Our results suggest that as we age, brain-behavior relations decline, and there is an increased reliance on both language-specific and domain-general brain regions that are seen most prominently during phonological processing. In contrast, the core semantic system continues to be engaged throughout the life span, even in the presence of task-irrelevant information.Item Open Access Age-related differences in the neural bases of phonological and semantic processes.(Journal of cognitive neuroscience, 2014-12) Diaz, Michele T; Johnson, Micah A; Burke, Deborah M; Madden, David JChanges in language functions during normal aging are greater for phonological compared with semantic processes. To investigate the behavioral and neural basis for these age-related differences, we used fMRI to examine younger and older adults who made semantic and phonological decisions about pictures. The behavioral performance of older adults was less accurate and less efficient than younger adults' in the phonological task but did not differ in the semantic task. In the fMRI analyses, the semantic task activated left-hemisphere language regions, and the phonological task activated bilateral cingulate and ventral precuneus. Age-related effects were widespread throughout the brain and most often expressed as greater activation for older adults. Activation was greater for younger compared with older adults in ventral brain regions involved in visual and object processing. Although there was not a significant Age × Condition interaction in the whole-brain fMRI results, correlations examining the relationship between behavior and fMRI activation were stronger for younger compared with older adults. Our results suggest that the relationship between behavior and neural activation declines with age, and this may underlie some of the observed declines in performance.Item Open Access Age-related slowing in the retrieval of information from long-term memory.(Journal of gerontology, 1985-03) Madden, DJThe present experiment investigated adult age differences in the retrieval of information from long-term memory. Each trial required a decision regarding the synonymy of two visually presented words. On the yes-response trials, the two words were either identical, differed only in case, or were synonyms that differed in case. Age differences in absolute decision time were greater for the synonyms than for the other word pairs, but the proportional slowing of decision time exhibited by the older adults was constant across word-pair type. A generalized age-related slowing in the speed of information processing can currently account for age differences in the retrieval of letter-identity and semantic information from long-term memory.Item Open Access Age-specific differences in oncogenic pathway deregulation seen in human breast tumors.(PLoS One, 2008-01-02) Anders, Carey K; Acharya, Chaitanya R; Hsu, David S; Broadwater, Gloria; Garman, Katherine; Foekens, John A; Zhang, Yi; Wang, Yixin; Marcom, Kelly; Marks, Jeffrey R; Mukherjee, Sayan; Nevins, Joseph R; Blackwell, Kimberly L; Potti, AnilPURPOSE: To define the biology driving the aggressive nature of breast cancer arising in young women. EXPERIMENTAL DESIGN: Among 784 patients with early stage breast cancer, using prospectively-defined, age-specific cohorts (young or=65 years), 411 eligible patients (n = 200or=65 years) with clinically-annotated Affymetrix microarray data were identified. GSEA, signatures of oncogenic pathway deregulation and predictors of chemotherapy sensitivity were evaluated within the two age-defined cohorts. RESULTS: In comparing deregulation of oncogenic pathways between age groups, a higher probability of PI3K (p = 0.006) and Myc (p = 0.03) pathway deregulation was observed in breast tumors arising in younger women. When evaluating unique patterns of pathway deregulation, a low probability of Src and E2F deregulation in tumors of younger women, concurrent with a higher probability of PI3K, Myc, and beta-catenin, conferred a worse prognosis (HR = 4.15). In contrast, a higher probability of Src and E2F pathway activation in tumors of older women, with concurrent low probability of PI3K, Myc and beta-catenin deregulation, was associated with poorer outcome (HR = 2.7). In multivariate analyses, genomic clusters of pathway deregulation illustrate prognostic value. CONCLUSION: Results demonstrate that breast cancer arising in young women represents a distinct biologic entity characterized by unique patterns of deregulated signaling pathways that are prognostic, independent of currently available clinico-pathologic variables. These results should enable refinement of targeted treatment strategies in this clinically challenging situation.Item Open Access Alcohol and drug use disorders among adults in emergency department settings in the United States.(Annals of emergency medicine, 2012-08) Wu, Li-Tzy; Swartz, Marvin S; Wu, Zunyou; Mannelli, Paolo; Yang, Chongming; Blazer, Dan GImproving identification and treatment for substance use disorders is a national priority, but data about various drug use disorders encountered in emergency departments (EDs) are lacking. We examine past-year substance use and substance use disorders (alcohol, 9 drug classes) among adult ED users. Prevalences of substance use and substance use disorders among ED nonusers are calculated for reference purposes.Using data from the 2007 to 2009 National Surveys on Drug Use and Health, we assessed substance use disorders among noninstitutionalized adults aged 18 years or older who responded to standardized survey questions administered by audio computer-assisted self-interviewing methods.Of all adults (N=113,672), 27.8% used the ED in the past year. ED users had higher prevalences than ED nonusers of coexisting alcohol and drug use (15.2% versus 12.1%), drug use (any drug, 16.9% versus 13.0%; marijuana, 12.1% versus 9.7%; opioids, 6.6% versus 4.1%), and alcohol or drug disorders (11.0% versus 8.5%). Among substance users, the ED group on average spent more days using drugs than the non-ED group; ED users manifested higher conditional rates of substance use disorders than ED nonusers (alcohol or drugs, 15.9% versus 11.7%; marijuana, 16.6% versus 13.2%; cocaine, 33.2% versus 22.3%; opioids, 20.6% versus 10.0%; stimulants, 18.6% versus 9.2%; sedatives, 35.0% versus 4.4%; tranquilizers, 12.4% versus 5.2%). Regardless of ED use status, substance-using young adults, men, and less-educated adults showed increased odds of having a substance use disorder.Drug use is prevalent and combined with high rates of drug use disorders among drug users treated in the ED.Item Open Access Alcohol dependence and use of treatment services among women in the community.(The American journal of psychiatry, 2004-10) Wu, Li-Tzy; Ringwalt, Chris LOBJECTIVE:This study examined the extent and characteristics of alcohol dependence and the perceived need for and use of alcohol treatment services among women compared with men in a nonclinical sample of adults 18-64 years of age. METHOD:Data were drawn from the 1999 National Household Survey on Drug Abuse. The authors calculated rates and correlates of alcohol dependence and treatment among adult alcohol users in this sample. RESULTS:About 3% of the women in the survey met criteria for DSM-IV alcohol dependence in the previous year. About 13% of these women received alcohol treatment services in the same period. Only 8% of the women who did not receive treatment perceived a need for treatment. Younger women-those who were 18-25 years of age-were more likely to be dependent on alcohol but less likely to perceive a need for treatment or to use treatment services. Among alcohol-dependent women who received no treatment, those with a family income of 75,000 US dollars or more, those who had two or more children living with them, and those who were not dependent on psychotherapeutic medications were less likely to perceive a need for help. CONCLUSIONS:There were no significant differences between men and women in use of treatment services, location of services received, and perceived need for treatment. However, correlates of treatment service use varied somewhat by gender. These findings suggest that the goal of efforts to reduce barriers to alcohol treatment services should be to change people's attitudes toward alcohol abuse and seeking professional help.Item Open Access Amino acid racemization reveals differential protein turnover in osteoarthritic articular and meniscal cartilages.(Arthritis Res Ther, 2009) Stabler, Thomas V; Byers, Samuel S; Zura, Robert D; Kraus, Virginia ByersINTRODUCTION: Certain amino acids within proteins have been reported to change from the L form to the D form over time. This process is known as racemization and is most likely to occur in long-lived low-turnover tissues such as normal cartilage. We hypothesized that diseased tissue, as found in an osteoarthritic (OA) joint, would have increased turnover reflected by a decrease in the racemized amino acid content. METHODS: Using high-performance liquid chromatography methods, we quantified the L and D forms of amino acids reported to racemize in vivo on a biological timescale: alanine, aspartate (Asp), asparagine (Asn), glutamate, glutamine, isoleucine, leucine (Leu), and serine (Ser). Furthermore, using a metabolically inactive control material (tooth dentin) and a control material with normal metabolism (normal articular cartilage), we developed an age adjustment in order to make inferences about the state of protein turnover in cartilage and meniscus. RESULTS: In the metabolically inactive control material (n = 25, ages 13 to 80 years) and the normal metabolizing control material (n = 19, ages 17 to 83 years), only Asp + Asn (Asx), Ser, and Leu showed a significant change (increase) in racemization with age (P < 0.01). The age-adjusted proportions of racemized to total amino acid (D/D+L expressed as a percentage of the control material) for Asx, Ser, and Leu when compared with the normal articular cartilage control were 97%, 74%, and 73% in OA meniscal cartilage and 97%, 70%, and 78% in OA articular cartilage. We also observed lower amino acid content in OA articular and meniscal cartilages compared with normal articular cartilage as well as a loss of total amino acids with age in the OA meniscal but not the OA articular cartilage. CONCLUSIONS: These data demonstrate comparable anabolic responses for non-lesioned OA articular cartilage and OA meniscal cartilage but an excess of catabolism over anabolism for the meniscal cartilage.Item Open Access An age-structured extension to the vectorial capacity model.(PLoS One, 2012) Novoseltsev, Vasiliy N; Michalski, Anatoli I; Novoseltseva, Janna A; Yashin, Anatoliy I; Carey, James R; Ellis, Alicia MBACKGROUND: Vectorial capacity and the basic reproductive number (R(0)) have been instrumental in structuring thinking about vector-borne pathogen transmission and how best to prevent the diseases they cause. One of the more important simplifying assumptions of these models is age-independent vector mortality. A growing body of evidence indicates that insect vectors exhibit age-dependent mortality, which can have strong and varied affects on pathogen transmission dynamics and strategies for disease prevention. METHODOLOGY/PRINCIPAL FINDINGS: Based on survival analysis we derived new equations for vectorial capacity and R(0) that are valid for any pattern of age-dependent (or age-independent) vector mortality and explore the behavior of the models across various mortality patterns. The framework we present (1) lays the groundwork for an extension and refinement of the vectorial capacity paradigm by introducing an age-structured extension to the model, (2) encourages further research on the actuarial dynamics of vectors in particular and the relationship of vector mortality to pathogen transmission in general, and (3) provides a detailed quantitative basis for understanding the relative impact of reductions in vector longevity compared to other vector-borne disease prevention strategies. CONCLUSIONS/SIGNIFICANCE: Accounting for age-dependent vector mortality in estimates of vectorial capacity and R(0) was most important when (1) vector densities are relatively low and the pattern of mortality can determine whether pathogen transmission will persist; i.e., determines whether R(0) is above or below 1, (2) vector population growth rate is relatively low and there are complex interactions between birth and death that differ fundamentally from birth-death relationships with age-independent mortality, and (3) the vector exhibits complex patterns of age-dependent mortality and R(0) ∼ 1. A limiting factor in the construction and evaluation of new age-dependent mortality models is the paucity of data characterizing vector mortality patterns, particularly for free ranging vectors in the field.Item Open Access An item response theory analysis of DSM-IV criteria for hallucinogen abuse and dependence in adolescents.(Addictive behaviors, 2010-03) Wu, Li-Tzy; Pan, Jeng-Jong; Yang, Chongming; Reeve, Bryce B; Blazer, Dan GAIM:This study applied both item response theory (IRT) and multiple indicators-multiple causes (MIMIC) methods to evaluate item-level psychometric properties of diagnostic questions for hallucinogen use disorders (HUDs), differential item functioning (DIF), and predictors of latent HUD. METHODS:Data were drawn from 2004-2006 National Surveys on Drug Use and Health. Analyses were based on 1548 past-year hallucinogen users aged 12-17 years. Substance use and symptoms were assessed by audio computer-assisted self-interviewing methods. RESULTS:Abuse and dependence criteria empirically were arrayed along a single continuum of severity. All abuse criteria indicated middle-to-high severity on the IRT-defined HUD continuum, while dependence criteria captured a wider range from the lowest (tolerance and time spent) to the highest (taking larger amounts and inability to cut down) severity levels. There was indication of DIF by hallucinogen users' age, gender, race/ethnicity, and ecstasy use status. Adjusting for DIF, ecstasy users (vs. non-ecstasy hallucinogen users), females (vs. males), and whites (vs. Hispanics) exhibited increased odds of HUD. CONCLUSIONS:Symptoms of hallucinogen abuse and dependence empirically do not reflect two discrete conditions in adolescents. Trends and problems related to hallucinogen use among girls and whites should be examined further to inform the designs of effective gender-appropriate and culturally sensitive prevention programs.Item Open Access An item response theory modeling of alcohol and marijuana dependences: a National Drug Abuse Treatment Clinical Trials Network study.(Journal of studies on alcohol and drugs, 2009-05) Wu, Li-Tzy; Pan, Jeng-Jong; Blazer, Dan G; Tai, Betty; Stitzer, Maxine L; Brooner, Robert K; Woody, George E; Patkar, Ashwin A; Blaine, Jack DOBJECTIVE:The aim of this study was to examine psychometric properties of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), diagnostics criteria for alcohol and marijuana dependences among 462 alcohol users and 311 marijuana users enrolled in two multisite trials of the National Drug Abuse Treatment Clinical Trials Network. METHOD:Diagnostic questions were assessed by the DSM-IV checklist. Data were analyzed by the item response theory and the multiple indicators-multiple causes method procedures. RESULTS:Criterion symptoms of alcohol and marijuana dependences exhibited a high level of internal consistency. All individual symptoms showed good discrimination in distinguishing alcohol or marijuana users between high and low severity levels of the continuum. In both groups, "withdrawal" appeared to measure the most severe symptom of the dependence continuum. There was little evidence of measurement nonequivalence in assessing symptoms of dependence by gender, age, race/ethnicity, and educational level. CONCLUSIONS:These findings highlight the clinical utility of the DSM-IV checklist in assessing alcohol- and marijuana dependence syndromes among treatment-seeking substance users.