Biomedical subjects

Rochelle E Tractenberg

Publications and source records attributed to Rochelle E Tractenberg.

At least 19 recordsLinked to original sources

PubMed2006

Use of steroid profiles in determining the cause of adrenal insufficiency.

HYPOTHESIS: A cortisol response to adrenocorticotropin injection is the standard test for diagnosing adrenal insufficiency. Multiple steroid hormones can now be accurately measured by tandem mass spectrometry in a single sample. The study objective was to determine whether a steroid profile, created by simultaneous measurement of 10 steroid hormones by tandem mass spectrometry, would help determine the cause of adrenal insufficiency. DESIGN: A 10-steroid profile was measured by tandem mass spectrometry during the performance of a standard high dose cortrosyn stimulation test. The steroids were measured at baseline, 30, and 60min following synthetic adrenocorticotropin injection. Adrenal insufficiency was defined as a peak cortisol level of less than 20microg/dL. Testing was conducted in the general clinical research center of a university medical center. Normal volunteers, patients suspected of having adrenal insufficiency, and patients with known adrenal insufficiency participated. RESULTS: Our results showed that adrenal insufficiency of any cause was adequately diagnosed using the response of 11-deoxycortisol, dehydroepiandrosterone, or these analytes combined in a two-steroid profile. A three-steroid profile yielded a test with 100% accuracy for discriminating primary adrenal insufficiency from normal status. Primary adrenal insufficiency was well separated from secondary adrenal insufficiency using only a single aldosterone value. 11-Deoxycortisol, dehydroepiandrosterone, and a two-steroid profile each provided fair discrimination between secondary adrenal insufficiency and normal status. CONCLUSIONS: We conclude that stimulated levels of aldosterone, 11-deoxycortisol, dehydroepiandrosterone, and a two- or three-steroid profile provided additional discrimination between states of adrenal sufficiency and insufficiency. It is proposed that a steroid profile measuring cortisol, aldosterone, 11-deoxycortisol, and dehydroepiandrosterone would potentially improve the ability to determine the cause of adrenal insufficiency.

Adrenal Cortex Hormones↗

PubMed2006

Accuracy, repeatability, and clinical application of spherocylindrical automated refraction using time-based wavefront aberrometry measurements.

PURPOSE: To evaluate the clinical utility of spherocylindrical automated refraction (AR) based on time-based wavefront technology compared with subjective manifest refraction (MR) for the purpose of prescribing eyeglasses. DESIGN: Prospective observational case series. PARTICIPANTS: A convenience sample of 105 eyes of 53 patients (ages 19 to 87) with corrected acuity no worse than 20/40(-2). METHODS: Manifest refraction was performed on all subjects followed by three consecutive wavefront measurements at both a 4-mm and 6-mm optical zone using the 3D Wave OPD Scan ARK 10,000 aberrometer. MAIN OUTCOME MEASURES: Repeatability of multiple consecutive ARs; difference in the sphere, cylinder, and axis of AR compared with MR; difference between the corrected visual acuity based on AR- and MR-derived acuity. RESULTS: Repeatability analysis showed that the initial wavefront refraction was not significantly different from the mean of the three refractions. At the 4-mm zone, the absolute value (+/- standard deviation) of the difference between the initial AR compared with the MR was 0.34+/-0.28 diopters (D) for sphere, 0.22+/-0.21 D for cylinder, and 12.5+/-15.8 degrees for axis. At the 6-mm zone, these values were 0.32+/-0.29 D for sphere, 0.25+/-0.24 D for cylinder, and 11.8+/-14.6 degrees for axis. When 4-mm AR visual acuity was superior to MR acuity (19.0% of eyes) it was 0.28+/-0.24 Snellen lines better, and when inferior (53.3% of eyes) it was 0.47+/-0.37 lines worse. When 6-mm AR acuity was superior to MR acuity (16.2% of eyes) it was 0.32+/-0.22 Snellen lines better, and when inferior (60.0% of eyes) it was 0.48+/-0.48 lines worse. The absolute value of the difference in spherical equivalent of the first AR measurement at the 4-mm zone compared with the MR value was 0.33+/-0.23 D, and at the 6-mm zone it was 0.30+/-0.27 D. CONCLUSIONS: The wavefront-derived AR values reflect the physical optical system, but not necessarily subjectively derived values, and the impact of this disagreement on patient satisfaction is unknown. Future studies evaluating this technology and its role in clinical ophthalmology are warranted.

Adult↗

PubMed2006

The smallpox vaccine: a multidimensional model of choice.

Following September 11, 2001, the U.S. government increased its efforts to prepare for future attacks, including those using dangerous biological agents such as smallpox. The smallpox vaccination program called for vaccinating military personnel and smallpox response teams, including healthcare workers and other first responders. The program of vaccinating healthcare workers was largely unsuccessful; few individuals volunteered to be vaccinated, highlighting the importance of understanding the factors that influence choice regarding this complex medical decision. This study examined stated choice and how it was associated with risk perceptions, knowledge, psychological distress, and general vaccine beliefs using a five-dimensional choice model. The model used multivariable modeling strategies in a sample of 256 undergraduate, graduate, and medical students. Sixty-three percent of the sample stated that they would elect to receive the smallpox vaccination. Multiple factors were related to stated choice in multivariable models, including perceived risk/worry, general vaccine beliefs, decisional conflict, and gender. However, the models were more successful at predicting acceptance of the vaccination than vaccine refusal. Although support was obtained for a multidimensional model of choice, several questions were raised by our results, including (a) whether refusal of smallpox vaccination can be more effectively characterized, possibly with additional questions; (b) whether the model translates to actual vaccination behavior; and (c) whether the model describes choice in more at-risk samples (e.g., first responders, healthcare workers). A multidimensional modeling approach should facilitate these and other studies of choice.

Adolescent↗

PubMed2006

Characterizing sleep problems in persons with Alzheimer's disease and normal elderly.

We retrospectively analyzed sleep disturbance symptoms and estimated time in bed from the intake interviews of 399 healthy, non-demented elderly (NDE) and 263 persons with a diagnosis of possible (n = 53) or probable (n = 210) Alzheimer's disease (AD). Our primary objective was to identify what symptoms might underlie an individual's perception of 'sleep problems' and to determine if these were consistent within, and across, our two cohorts. We stratified each cohort according to whether or not they (or their caregiver) indicated that they had a 'sleep problem', and compared the frequency and endorsement rates of each of 21 sleep disturbance symptoms across those who did or did not endorse 'sleep problem'. For less than half of the symptoms in persons with AD, and a quarter of those in NDE, endorsement rates were significantly different depending on whether the reporter (or their sleep partner) did or did not report a sleep problem. Differences in mean frequency ratings between individuals reporting sleep problems relative to those not reporting were observed on 10 symptoms in both cohorts; six of these were the same symptom for both cohorts. When persons with subjective sleep problems in the AD and NDE cohorts were compared, only four of 21 symptoms were endorsed in one and not the other; two symptoms were significantly more frequent in one cohort than the other. Thus, within cohorts, the differences between persons with and without 'sleep problems' were relatively pronounced while the main differences in specific sleep-related symptoms between AD and NDE were not. Observed between-cohort differences appear to be driven by who is reporting, and the high prevalence of daytime sleeping in AD. Within-cohort differences reflect a clear distinction between persons with and without sleep problems, regardless of the reporter.

Aged↗

PubMed2006

Developing an interactive approach in teaching medical informatics.

A new masters program in medical informatics is proposed for development at the University of Medicine and Pharmacy in Timisoara. Given the rapidly changing technology itself and its deployment in biomedical science, the master's program curriculum has to be multidisciplinary, comprehensive and coherent in conveying the concepts, as well as the interdisciplinary character, of medical informatics (MI). We describe the rationale and methods for a pilot study to develop a new, interactive approach in teaching MI. The study is being conducted within the existing MI course offered for the medical students in order to evaluate its impact on instruction and determine if a larger scale design is feasible. Two teaching teams of four instructors have been assigned to one of two tracks in our pilot study: traditional instruction or interactive instruction. After one term we have gained important information about how the structural and instructional aspects of the pilot design may influence confidence and attitudes.

Humans↗

PubMed2005

Steroid hormone levels in pregnancy and 1 year postpartum using isotope dilution tandem mass spectrometry.

OBJECTIVE: To establish normal, trimester-specific reference intervals for serum 17beta-estradiol, progesterone (P), 17alpha-hydroxyprogesterone, cortisol, 11-deoxycortisol, androstenedione, DHEA, and DHEAS, measured simultaneously using isotope dilution tandem mass spectrometry. DESIGN: Sequential cohort study. PATIENT(S): Healthy women undergoing a normal pregnancy (age, 25-38 years; mean, 30 years) attending a prenatal well clinic at gestation weeks 12, 22, and 32 and approximately 1 year postpartum. MAIN OUTCOME MEASURE(S): Trimester-specific reference intervals of endogenous steroid hormones analyzed using an isotope dilution tandem mass spectrometer equipped with an atmospheric pressure photoionization source with deuterium-labeled internal standards. RESULT(S): Serum estradiol, P, 17alpha-hydroxyprogesterone, and 11-deoxycortisol increased throughout pregnancy; cortisol increased up to the second trimester and then remained steady, while androstenedione increased by 80 percent by gestation week 12, then remained constant. Serum DHEA-S decreased by 50% by the third trimester. CONCLUSION(S): Trimester-specific reference intervals are reported for eight serum steroids. The ratios of individual serum hormone concentrations during pregnancy relative to their 1-year postpartum concentrations illustrate the expected normal trends of changes in hormone concentrations during pregnancy.

Adult↗

PubMed2005

Do thyroxine and thyroid-stimulating hormone levels reflect urinary iodine concentrations?

The toxicity of environmental chemicals such as nitrates, thiocynates, and perchlorates, some therapeutics, and dietary goitrogens can lower thyroidal iodine uptake and result in hypothyroidism and goiter. Iodine sufficiency, essential for normal thyroid hormone synthesis, is critical during gestation to assure that sufficient thyroxine (T4) and iodine reach the developing fetus. Spot urinary iodide (UI) measurements are used globally to indicate and monitor iodine sufficiency of populations. In individuals, however, UI are not routinely measured; instead, normal serum thyroid-stimulating hormone (TSH) and T4 concentrations serve as surrogate indicators of iodine sufficiency as well as thyroidal health. Our objective was to examine the relationship between UI concentrations and serum T4 and TSH concentrations in individuals in an "iodine-sufficient population." Using a cross-sectional sample of the US population (n = 7628) from the National Health and Nutrition Examination Survey (NHANES III; 1988-1994) database, we examined the relationship among UI, T4, and TSH in pregnant and nonpregnant women and in men (15-44 years). There was a lack of relationship between UI (or UI/Cr) concentrations and serum T4 or TSH concentrations. Therefore, TSH and T4 are not appropriate markers of UI concentrations in this population. Monitoring the status of iodine nutrition of individuals in the United States may be important because serum TSH and T4 concentrations do not indicate low iodine status.

Adolescent↗

PubMed2005

Symptoms of sleep disturbance in persons with Alzheimer's disease and normal elderly.

We retrospectively analyzed sleep time and sleep disturbance symptoms in 399 healthy, non-demented elderly (NDE) and 263 persons with a diagnosis of possible (n = 53) or probable (n = 210) Alzheimer's disease (AD). Our primary objective was to determine differences in subjective sleep disturbance between these samples. Secondary objectives were to determine if subjects with time in bed (TIB) < or =6 h per night reported more sleep disturbance and whether sleep complaints were associated with more severe cognitive and/or functional impairment. The prevalence of 'sleep problems' (a single item) was significantly lower in NDE (18.3%) than AD (27.6%), and the proportions of each cohort reporting TIB < or =6 h per night were very low (NDE: 6.0%; AD: 3.5%) and not significantly different. Less TIB was correlated with better cognitive function for AD (P < 0.01), and cognition and function were significantly worse for AD subjects with estimates of >6 h of TIB compared with those with estimates of < or =6 h (P < 0.05). Greater sleep disturbance was correlated with greater functional impairment in both cohorts; but only in AD did greater estimated TIB also correlate with greater functional impairment (all P < 0.05). In general, estimated TIB was not associated with mood in either cohort; however, in both cohorts depression was significantly associated with sleep disturbance symptoms and was significantly worse in those who reported having 'sleep problems'. There was no association between subjective perception of 'sleep problems', the number and frequency of sleep disturbance symptoms, and estimated TIB in either group.

Activities of Daily Living↗

PubMed2005

Independence of changes in behavior from cognition and function in community-dwelling persons with Alzheimer's disease: a factor analytic approach.

The authors' main objective was to investigate the relationship between changes in psychopathological, cognitive and activity of daily living (ADL) instrument scores over 12 months in community-dwelling persons with Alzheimer's disease (AD). A secondary objective was to evaluate the validity of dividing the Clinical Dementia Rating (CDR), a global dementia staging instrument into cognitive and functional subscores. Changes in measures of psychopathology, cognition and function between the baseline and 12-month visits were entered into these post hoc analyses of data from a one-year clinical trial to evaluate behavioral, cognitive and functional assessment instruments for use in clinical trials with AD patients. Exploratory factor analysis was used to determine whether there was independence between changes in any of these three domains of interest for this disease population; participants were a cohort of 187 well-characterized, community-dwelling persons with AD. One-year change in the behavioral symptoms of this cohort of persons with AD was statistically independent from changes in scores on cognitive and functional measures. Some evidence of independence of 12 month changes in cognitive and functional measures was found. Cognitive and functional subscores for the CDR were supported. These findings suggest that changes in behavior and cognition in dementia may have distinct pathophysiologies.

Activities of Daily Living↗

PubMed2004

Benchmarking a test of temporal orientation with data from american and taiwanese persons with Alzheimer's disease and american normal elderly.

Orientation questions are readily incorporated into longitudinal population surveys, but their value as a screening tool for cognitive impairment is uncertain. We evaluated the screening value of four orientation-to-time items (TTO) from the Mini-Mental State Examination (MMSE) by determining their association with full-scale MMSE scores. Data collected under protocols with strict eligibility criteria in the US (64 normal elderly, 242 persons with probable Alzheimer's disease) and Taiwan (241 persons with probable Alzheimer's disease) were analyzed. The TTO and full-scale MMSE scores were significantly correlated (p < 0.05) in persons with a Clinical Dementia Rating (CDR) score of 0 or 1; this was not significant in persons with a CDR of >1 (p > 0.05). Both TTO and MMSE were significantly associated with education in persons with 0-7 years of education; some MMSE items, but none of the TTO items, were associated with education in persons with more than 7 years of education. TTO may be a useful component of cognitive screening efforts.

Aged↗

PubMed2004

Executive dysfunction in Alzheimer disease.

BACKGROUND: Executive dysfunction (EDF) is common in Alzheimer disease (AD); however, its relationship to other symptoms is difficult to assess in patients with AD. OBJECTIVES: To determine the prevalence of EDF and study its relationship to cognitive, functional, and neuropsychiatric symptoms in patients with AD. DESIGN, SETTING, AND PATIENTS: A retrospective analysis of data from participants in the English Instruments Protocol of the Alzheimer's Disease Cooperative Study. Subjects were drawn from a sample of patients evaluated at tertiary referral centers. RESULTS: A total of 64% of AD patients were classified as having EDF. Patients with EDF performed worse on tests of cognition (P <.001), dementia severity (P <.001), and activities of daily living (P =.01) and had more frequent symptoms of psychosis (P =.03) with greater emergence during the 12-month interval (P =.03) compared with patients with normal executive function. Less than 30% of the variance in executive function performance was explained by cognitive measures. CONCLUSION: These findings support the assessment of executive function in persons with AD and the importance of frontal lobe dysfunction in AD.

Activities of Daily Living↗

PubMed2004

Differences between measurements of T4 and T3 in pregnant and nonpregnant women using isotope dilution tandem mass spectrometry and immunoassays: are there clinical implications?

BACKGROUND: It has been established that triiodothyronine (T3) and thyroxine (T4) measurements by tandem mass spectrometry (MS/MS) are more specific and are significantly different from immunoassay (IA) measurements (all p< or =0.05) throughout pregnancy. In this study, we examined the clinical implications of these discrepancies. METHODS: Kappa statistics were used to determine the degree to which IA and MS/MS agreed in their identification of out-of-reference interval observations of circulating T4 and T3 from 52 normal, iodine-sufficient women during each trimester of pregnancy. RESULTS: After taking chance agreement into account, the two methods had poor agreement on classification of T3 values at the first (kappa=0.185) and second (kappa=0.183) trimesters, with extremely poor agreement for the third trimester and 1-year postpartum. Agreement on T4 was poor only for the third trimester (kappa=0.183). The two methods agreed on out-of-range values in only 0-25% of T3 cases and 25-66.7% of T4 cases. CONCLUSIONS: The areas of disagreement suggest that women at risk (i.e., with analyte values outside of the 5-95% range) will not be detected using IA. Based on this cohort, our preliminary estimates are that 25-100% of such women would be missed if IA were used to assay the analyte.

Adult↗

PubMed2004

Regression to the mean: implications for clinical trials of psychotropic agents in dementia.

Effective drug development depends on understanding and optimizing results from controlled clinical trials. A recent double-blind, randomized, controlled trial of the treatment of agitation in patients with Alzheimer's disease (AD) found no difference among the four arms of the study: haloperidol, trazodone, behavioral therapy, placebo. The current analysis was undertaken to further investigate the issues bearing on this outcome and to identify better means of detecting psychotropic effects in trials involving patients with AD. This was post hoc analysis of a clinical trial data set. Patients in the placebo group were divided into responders (25% reduction in symptoms), worseners (25% worsening in baseline agitation scores), and those without a change in symptoms. Analysis of the trial outcomes demonstrated that the reduction observed in the placebo group was of the same magnitude as predicted by regression to the mean. Patients exhibiting greater improvement had more severe baseline behavioral disturbances. The relatively modest severity of agitation and the low medication doses achieved in the study may have further contributed to the failure to distinguish among treatment groups. Research design adjustments such as collection of both screening and baseline measures to determine eligibility may limit the effects of regression to the mean on trial outcomes and reduce this challenge to clinical trials.

Aged↗

PubMed2003

A multicenter, placebo-controlled trial of melatonin for sleep disturbance in Alzheimer's disease.

OBJECTIVES: To determine the safety and efficacy of 2 dose formulations of melatonin for the treatment of insomnia in patients with Alzheimer's disease. DESIGN: A multicenter, randomized, placebo-controlled clinical trial of 2 dose formulations of oral melatonin coordinated by the National Institute of Aging-funded Alzheimer's Disease Cooperative Study. Subjects with Alzheimer's disease and nighttime sleep disturbance were randomly assigned to 1 of 3 treatment groups: placebo, 2.5-mg slow-release melatonin, or 10-mg melatonin. SETTING: Private homes and long-term care facilities. PARTICIPANTS: 157 individuals were recruited by 36 Alzheimer's disease research centers. Subjects with a diagnosis of Alzheimer's disease were eligible if they averaged less than 7 hours of sleep per night (as documented by wrist actigraphy) and had 2 or more episodes per week of nighttime awakenings reported by the caregiver. MEASUREMENTS: Nocturnal total sleep time, sleep efficiency, wake-time after sleep onset, and day-night sleep ratio during 2- to 3-week baseline and 2-month treatment periods. Sleep was defined by an automated algorithmic analysis of wrist actigraph data. RESULTS: No statistically significant differences in objective sleep measures were seen between baseline and treatment periods for the any of the 3 groups. Nonsignificant trends for increased nocturnal total sleep time and decreased wake after sleep onset were observed in the melatonin groups relative to placebo. Trends for a greater percentage of subjects having more than a 30-minute increase in nocturnal total sleep time in the 10-mg melatonin group and for a decline in the day-night sleep ratio in the 2.5-mg sustained-release melatonin group, compared to placebo, were also seen. On subjective measures, caregiver ratings of sleep quality showed improvement in the 2.5-mg sustained-release melatonin group relative to placebo. There were no significant differences in the number or seriousness of adverse events between the placebo and melatonin groups. CONCLUSIONS: Based on actigraphy as an objective measure of sleep time, melatonin is not an effective soporific agent in people with Alzheimer's disease.

Aged↗

PubMed2003

Antiviral and immunological benefits in HIV patients receiving intranasal peptide T (DAPTA).

D-Ala-Peptide T-amide (DAPTA), the first viral entry inhibitor, blocks chemokine (CCR5) receptors, not CD4. Early investigators could not "replicate" DAPTAs potent in vitro antiviral effect using the lab-adapted, X4, peptide T-insensitive strain, IIIB, delaying clinical virological studies. We now report that DAPTA, administered to eleven long-term infected (mean=17 years) patients with stable persistent plasma "virus" for up to 32 weeks did not change this level. Infectious virus could not be isolated from their plasma suggesting HIV RNA was devoid of replicative capacity. Progressively less actual virus (P<0.01) could be isolated from white blood cells (PBMCs). DAPTA flushed the monocyte reservoir to undetectable viral levels in most patients. Five of eleven had a mean CD4 increase of 33%. Immune benefits also included a four-fold increase in gamma-interferon-secreting T-cells (antiviral cytotoxic T-cells) in the absence of drug-related toxicity. All five CD4 responders had increases in antiviral T cells and decreases in infected monocytes, an argument for initiating further studies promptly.

Administration, Intranasal↗

PubMed2003

The Sleep Disorders Inventory: an instrument for studies of sleep disturbance in persons with Alzheimer's disease.

The Sleep Disorders Inventory (SDI) is an expanded version of one item of the Neuropsychiatric Inventory (NPI). It describes the frequency, severity, and caregiver burden of sleep-disturbed behaviors during a period prior to its administration. We carried out post hoc analyses on baseline responses to the SDI in 104 persons with Alzheimer's disease (AD) and live-in caregivers who had been recruited for a trial of melatonin in the treatment of sleep disturbance. These patient-participants averaged <7 h of sleep per night, measured by actigraph (sleep disturbance), for the 2-3-week period prior to administration of SDI. Data were from the 2 weeks prior to the baseline visit (SDI, NPI) including actigraph-derived sleep variables and 2 weeks' worth of sleep quality ratings (SQR) kept in a diary by caregivers, plus Mini-Mental State Examination and activities of daily living assessment at baseline. The prevalence of sleep disorder symptoms ranged from 34% (waking up at night thinking it is daytime) and 82% (getting up during the night). Worse SDI scores were associated with worse cognitive, functional, and behavioral status, but not with sex, age, education or duration of dementia. SDI scores were significantly worse in individuals meeting independently established criteria for a diagnosis of 'sleep disturbance' (<6 h total sleep time per night) whereas demographic variables and scores reflecting cognition and function were not significantly different across this grouping. The SDI covers a wide range of sleep behaviors and provides information independent of sleep time and SQR.

Aged↗

PubMed2003

Comorbidity of psychopathological domains in community-dwelling persons with Alzheimer's disease.

In this post hoc analysis of baseline responses to the CERAD Behavior Rating Scale for Dementia in a clinical trial of interventions for agitation in Alzheimer's disease (AD), the authors investigated the distribution of, and relationships between, agitation, depression, and psychosis in 148 individuals with AD. Prevalence of depressive symptoms was highest (78.4%), followed by agitation (77.6%) and psychotic symptoms (69.3%); 51.1% of the sample had symptoms in all 3 domains. Cross-sectionally, psychotic symptoms were most closely associated with Mini-Mental State Examination (MMSE) scores, while agitation was less so. Depressive symptoms were relatively consistently prevalent across MMSE levels. After controlling for the presence of agitated symptoms, psychosis and depression were significantly associated, but neither symptoms of psychosis nor of depression were associated with agitation when depression or psychosis, respectively, was controlled for. Significant psychopathological comorbidity should be considered in the design of clinical trials targeting particular psychopathology in this disease population.

Aged↗

PubMed2002

Estimating the prevalence of agitation in community-dwelling persons with Alzheimer's disease.

To estimate the prevalence of, and develop norms for, significant agitation in community-dwelling persons with Alzheimer's disease (AD), the authors applied three different criteria to persons with AD (n=235) and normal elderly control subjects (NEC; n=64). The criteria were used to identify the minimum total score on the Cohen-Mansfield Agitation Inventory (CMAI) that represents significant or "excessive" agitation and to estimate its prevalence. The "ultraliberal" criterion resulted in 99.1% of persons with AD and 56.6% of NEC being classified as "excessively" disturbed. The "liberal" and "conservative" criteria classified 66.7% and 68.2% of persons with AD, and no NEC, as "excessively" disturbed. The authors conclude that the best estimate of prevalence of excessive agitation in this population is 67.5%, and that individuals with CMAI scores of 0 to 14 probably should not be considered to have excessive agitation.

Activities of Daily Living↗