Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dual Data Collection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMed1987

Twenty-four hour monitoring of deep body temperature with a novel flexible probe.

A portable thermomemory unit with a light, thin and flexible probe has been developed for the measurement of whole-day variations in deep body temperature. The probe consists of a thermistor, a heat-flow sensor and a heater. The probe detects heat flow from the skin; the heater then compensates for the heat lost and consequently the skin is effectively insulated from the ambient microenvironment. Skin temperature beneath the probe is therefore determined by the deep body temperature. The probe is 46 mm in diameter and 3 mm thick, its weight is 5 g. The probe is light and flexible and makes close contact with the skin. A 2 kbyte RAM in the unit enables up to 34 h of data to be collected with a sampling rate of once per minute. The device was applied to the chest and abdominal walls, and to the calf; the chest and abdominal deep body temperatures showed a significant dual phase diurnal variation, usually being low during sleep. In contrast, the calf showed a dynamic deep body temperature variation which depended on the amount of leg exercise. The device was found to be effective for analysing daily variations; measurements on the limbs suggested that it could be used for monitoring peripheral circulatory disorders.

Biomedical Engineering↗
PubMed2007

Bone mineral density and its related factors in elderly male Chinese patients with type 2 diabetes.

BACKGROUND: There have been few investigations conducted on the epidemiology and risk factors of osteoporosis in patients with diabetes in China. The aim of this study was to disclose the percentage and the possible risk factors that influence bone mineral density (BMD) in this population. METHODS: One hundred thirty-one elderly male patients with type 2 diabetes (73.12 +/- 5.54 years of age, diabetic duration 5.28 +/- 3.56 years, HbA(1C) 7.87% +/- 1.82 %), >65 years of age were recruited. All subjects were submitted to dual-energy X-ray absorptiometry to evaluate the BMD at lumbar spine (LS), femoral neck (FN), and femoral trochanter (FT). Fasting blood samples were taken to check hormones and biochemical levels. Demographic data were also collected. RESULTS: In the different bone sites studied, the percentage of osteoporosis and osteopenia varied in this group of patients ranging from 29.0 to 31.3% and 29.0 to 33.6%, respectively. Weight, HbA(1C), body mass index, and testosterone were correlated with BMD at all the bone sites studied. Weight was the best predictor among the above parameters for BMD by linear regression analysis at LS and FN, whereas testosterone was the best predictor for BMD at FT. CONCLUSIONS: In the different bone sites studied, the percentage of osteoporosis and osteopenia varied ranging from 29.0 to 31.3% and 29.0 to 33.6%, respectively. Weight was the best predictor for BMD at LS and FN and testosterone was the best predictor for BMD at FT. Poor glycemic control was correlated with osteoporosis.

Absorptiometry, Photon↗
PubMed2006

Bone mineral density in postmenarchal adolescent girls in the United States: associated biopsychosocial variables and bone turnover markers.

PURPOSE: During adolescence, bone formation prevails over resorption, resulting in accumulation of 40% of peak bone mass throughout this time period. Although multiple studies have explored bone mass accrual during the early stages of puberty, less is known about factors that may influence bone accrual during later years of adolescence. In the present cross-sectional study we examined relationships among bone mineral density (BMD) and demographic factors, behavioral variables, and bone metabolism markers in postmenarchal adolescent girls. METHODS: The population was comprised of 389 healthy postmenarchal adolescent girls aged 11-18 years, who were recruited into a prospective study of the effect of depot medroxyprogesterone acetate (DMPA) on bone health in adolescents. At the baseline visit, investigators collected demographic, reproductive health, and lifestyle data, and performed a complete physical examination. Body mass index (BMI) was calculated. Before study initiation, BMD at the lumbar spine, total hip, and femoral neck was measured by dual-energy X-ray absorptiometry (DXA), and markers of bone metabolism (serum bone-specific alkaline phosphatase [BAP], serum osteocalcin, and urinary N-telopeptide [uNTX]) were measured. The baseline data from this study were analyzed to evaluate possible correlates of BMD in postmenarchal adolescent girls. Potential associations between BMD values and other parameters were assessed by analysis of variance and Pearson's correlation coefficient. RESULTS: Participants enrolled in the study had a mean (+/- SD) chronological age of 14.9 +/-1.7 years (range 11-18), mean gynecologic age of 39.9 +/-23.0 months (range 1-120) postmenarche, and mean BMI of 23.5 +/-4.6 kg/m(2) (range 16.0-42.2). Racial/ethnic distribution was 46% African American, 35% Caucasian, and 19% other races; 9% had previously been pregnant. Positive correlations were observed between lumbar spine BMD and chronological age (r = .301, p < .0001), gynecologic age (r = .349, p < .0001), and BMI (r = .371, p < .0001). Total hip and femoral neck BMD values were significantly higher (p < .05 and p < .05, respectively) in African American participants compared with non-African American participants. Previous history of pregnancy was significantly associated with a lower BMD at the lumbar spine (p < .0001) and the total hip (p < .01) when compared with the BMD of adolescents who had never been pregnant. Cigarette smoking and alcohol use were not associated with significant differences in BMD. Negative correlations were observed between gynecologic age and the levels of BAP (r = -.564, p < .0001), osteocalcin (r = -.349, p < .0001), and uNTX (r = -.281, p < .0001), and between lumbar spine BMD and BAP (r = -.363, p < .0001), osteocalcin (r = -.129, p < .05), and uNTX (r = -.202, p < .001) levels. CONCLUSIONS: Our data demonstrate that chronological age, gynecologic age, race/ethnicity, BMI, and previous history of pregnancy are markedly associated with BMD in postmenarchal adolescent girls. Bone accretion in the postmenarchal years continues in the face of a slowdown in bone turnover during this time period.

Adolescent↗
PubMed2004

Enhanced expression of cytokines and chemokines by blood monocytes to in vitro lipopolysaccharide stimulation are associated with hostility and severity of depressive symptoms in healthy women.

The current study investigated the relation of hostility and severity of depressive symptoms, separately and jointly, to the capacity of blood monocytes to secrete an array of cytokines when stimulated by bacterial lipopolysaccharide (LPS). Subjects were 44 healthy, non-smoking, premenopausal women (aged 23-49 years) not currently taking oral contraceptives. Data were collected during the follicular phase of the menstrual cycle. The Cook-Medley Hostility (Ho) scale and the Beck Depression Inventory (BDI) were used to assess hostility and severity of depressive symptoms, respectively. Dual-color flow cytometry was used to measure the total expression of interleukin (IL)-1alpha, IL-1beta, IL-8, tumor necrosis factor (TNF)-alpha, monocyte chemotactic protein (MCP)-1 and monocyte inflammatory protein (MIP)-1alpha in blood monocytes following 4 h in vitro LPS stimulation of whole blood. In analyses adjusting for age, body mass index (BMI), fasting cholesterol, alcohol use, race and 17beta-estradiol (E(2)), higher Ho scores were associated with greater LPS-stimulated expression of IL-1alpha (beta = 0.033, p = 0.02), IL-8 (beta = 0.046, p = 0.01) and IL-1beta (beta = 0.024, p = 0.06). Higher BDI scores were associated with greater expression of TNF-alpha (beta = 0.042, p = 0.02) and IL-8 (beta = 0.045, p = 0.04). The linear combination of Ho and BDI scores was significantly associated with IL-1beta (beta = 0.18, p = 0.057), IL-8 (beta = 0.36, p = 0.01), TNF-alpha (beta = 0.25, p = 0.03), and IL-1alpha (beta = 0.18, p < 0.07). Thus, in healthy women, these psychological risk factors, alone and in combination, induce a proinflammatory phenotype in circulating monocytes characterized by the up-regulation of proinflammatory cytokines, supporting the hypothesis that inflammation may be a key pathway whereby hostility and depressive symptoms contribute to atherosclerosis and subsequent coronary heart disease (CHD).

Cells, Cultured↗
PubMed1999

A closer look at General Dental Service orthodontics in England and Wales. I: Factors influencing effectiveness.

OBJECTIVE: To evaluate factors influencing effectiveness in General Dental Service (GDS) orthodontics. DESIGN: Retrospective analysis of systematic 2% sample of GDS (England and Wales) cases. METHOD: Records of cases were collected during 1991. Assessment involved occlusal indices and data from National Health Service forms for 1,411 cases. Multivariate analyses were used with Peer Assessment Rating Index (PAR) score at Finish as the outcome indicator. RESULTS: Dual arch fixed appliances: achieved lower Finish PAR scores than other appliances; only 1.5% of the variance was explained, by treatment time and Dental Health Component of the Index of Orthodontic Treatment Need (DHC). Finish PAR was unaffected by Starting PAR. All other appliances: the model explained 25% of the variance for Finish PAR, which varied with Starting PAR and DHC scores. Social class had effects of little clinical significance, but the data suggested availability of orthodontic treatment was poorer in 'manual class' areas. Orthodontic qualifications, number of arches treated and mixed dentition starts had no significant effects when submitted to multivariate analysis. CONCLUSIONS: The importance of appliance selection is reinforced: dual arch fixed appliances are generally more consistent. Lower social class areas may be poorly provided with orthodontic services.

Age Factors↗
PubMed2002

Pathological findings in the central nervous system of AIDS patients on assumed antiretroviral therapeutic regimens: retrospective study of 1597 autopsies.

OBJECTIVE: To evaluate the prevalence of HIV-related central nervous system (CNS) lesions (HIV-encephalitis and/or HIV-leukoencephalopathy: HIV-E/L) with and without concomitant opportunistic diseases in a large autopsy series, and to correlate it with the changes in antiretroviral treatment that have occurred since the beginning of the epidemic. METHODS: We reviewed 1597 consecutive autopsies of HIV-positive patients performed between 1984 and 2000, and divided into four time periods on the basis of the therapeutic regimens available: 1984-1987, no therapy; 1988-1994, monotherapy (zidovudine); 1995-1996, dual combination therapy with nucleoside reverse transcriptase inhibitors (NRTI); and 1997-2000, triple combination therapy including two NRTI and at least one protease inhibitor or non-NRTI. The data concerning the treatment actually received were collected only for the patients who died during the last period. The chi -test was used to assess the significance of the differences in prevalence. RESULTS: The CNS of 1210 patients (76%) was affected by opportunistic diseases, HIV-related lesions or both. The prevalence of HIV-related lesions in the four periods was respectively 54%, 32%, 18% and 15%; this reduction was statistically significant (P < 0.000001). During the last period, however, differences in HIV-E/L between treated and untreated patients were not statistically significant, although there were fewer than expected cases among the treated patients (six instead of eight) and more than expected among the untreated patients (10 instead of eight). CONCLUSIONS: These neuropathological data from a large autopsy series confirm clinical observations concerning the efficacy of antiretroviral treatment in reducing the frequency of HIV-related CNS lesions in AIDS patients.

AIDS Dementia Complex↗
PubMed2003

SAD manganese in two crystal forms of glucose isomerase.

Glucose isomerase from Streptomyces rubiginosus was crystallized in two forms: I222, with one molecule of 44 kDa in the asymmetric unit, and P2(1)2(1)2, with two unique molecules. The I222 structure is known, but the P2(1)2(1)2 form has not been solved before. X-ray diffraction data for the P2(1)2(1)2 form were collected at a wavelength of 1.54 A and data for the I222 form were collected at three different wavelengths: 1.34, 1.07 and 0.98 A. The amount of anomalous signal from one Mn and eight S atoms in these data sets varies from 1.24% to as low as 0.56%. The dual-space direct-methods program SHELXD, run against the Bijvoet differences, gave a clear solution of all anomalous scatterers for all data sets. The Mn positions only were used for SAD phasing of all four data sets. The electron-density map after density modification, resulting from the phasing of a single-wavelength data set and based purely on the anomalous deltaf" contribution, was clearly interpretable; an almost complete model of the protein was built by wARP without human intervention in all four cases. As far as is known, this is the first time that an anomalous signal as low as 0.6% has successfully been used to determine the structure of a macromolecule.

Aldose-Ketose Isomerases↗
PubMed2001

Epidermal growth factor and gonadotropin-releasing hormone stimulate proliferation of enriched population of gonadotropes.

Recent studies of epidermal growth factor (EGF) receptors on gonadotropes show that they appear early in the estrous cycle on immature gonadotropes, most of which could be identified by LH messenger RNA only. As diestrous gonadotropes translate the messenger RNAs, the percentages of LH and FSH cells with EGF receptors increase to reach a peak during proestrus. To learn more about the function of EGF in gonadotrope regulation, parallel studies of its mitogenic potential were conducted. To test this in a cell growth assay, we initially developed a protocol for enrichment of gonadotropes by counterflow centrifugation (elutriation). Analysis of immunolabeled cells in the enriched fraction showed that the population contained 90-95% cells with LH and/or FSH antigens. Less than 4% have TSH or PRL antigens, and less than 7% have ACTH antigens. About 15% of the enriched population expressed GH antigens in male rats and nearly 30% of the population express GH in females. This agrees with the known hormone storage overlap between these cells, especially in proestrous female rats. The MTT cell growth/cell death assay was then used to test the mitogenic potential of EGF, GnRH, and activin. This assay showed a linear relationship between plated cell numbers and optical density of the media after the MTT reaction was run. The enriched gonadotropes were plated in 96-microwell trays and grown for 3-4 days in the presence of defined media alone (no serum), or defined media containing 0.5-10 ng/ml EGF, 0.5-1 nM GnRH, 60 ng/ml activin or two of these factors. In all of the 12 experiments, each of the factors stimulated a 3- to 10-fold increase in optical density values, depending on the dose of the stimulating factor. The effects of any two factors were not additive. Because the MTT assays do not discriminate between mitogenic effects and enhanced cell survival, a second group of tests was run with mixed cultures of pituitary cells from diestrous female rats. These cells were cultured in the same combinations of EGF with and without GnRH for 3 h. During the last hour of culture, they were exposed to bromodeoxyuridine (BrDU) to identify cells that were synthesizing DNA. Cells in the S phase were thereby detected with dual immunocytochemical labeling for nuclear BrDU and gonadotropins. The analysis of dual labeled cells showed a 3-fold increase in percentage of LH or FSH cells with BrDU labeled nuclei following EGF or GnRH stimulation. The effects of the two growth factors were not additive. Collectively, these data confirm previous studies showing mitogenic functions for activin and now add EGF and GnRH as mitogens for gonadotropes.

Activins↗
PubMed2000

Alveolar bone height and postcranial bone mineral density: negative effects of cigarette smoking and parity.

BACKGROUND: Our objective was to test the association between cemento-enamel junction, alveolar-crest distance (CEJ-AC, as measured on digitized vertical bite-wing radiographs) and postcranial bone mineral density (BMD) relative to clinical, dietary, and demographic variables. METHODS: Data were collected in a cross-sectional study of 134 postmenopausal women. CEJ-AC distances were determined from digitized vertical bite-wing radiographs. Lumbar spine and proximal femur BMDs were determined from dual-energy x-ray absorptiometric scans. Correlation analysis and Student t tests were used to identify those variables most associated with CEJ-AC distance. The selected variables were modeled with a backward stepwise regression analysis, with CEJ-AC distance as the dependent variable. RESULTS: Parity (number of pregnancies to term), cigarette smoking, and the interaction of lateral spine BMD with cigarette smoking were independent predictors of CEJ-AC distance (P < or =0.05). Statistical models containing these variables accounted for 19% of the variation in CEJ-AC distances. CONCLUSIONS: CEJ-AC distance in postmenopausal women is the result of a complicated interaction of many effects, including but not limited to, parity, cigarette smoking, and skeletal BMD.

Absorptiometry, Photon↗
PubMed2006

Functional significance of bone density measurements in children with osteogenesis imperfecta.

BACKGROUND: The treatment of osteogenesis imperfecta has been directed at improvement of bone mineral density, yet the importance of bone mineral density in predicting functional and clinical outcome in this patient population has not been demonstrated. We used a validated functional outcome measure to identify the relationship between bone mineral density and physical function in children with osteogenesis imperfecta, and we also evaluated the relationship of bone mineral density to the rate of surgery and fracture in patients with osteogenesis imperfecta. METHODS: Twenty patients (age range, four to seventeen years) with osteogenesis imperfecta who had undergone bone mineral densitometry as measured by dual x-ray absorptiometry of the lumbar spine, wrist, and proximal aspect of the femur between November 1999 and April 2001 were retrospectively analyzed. Functional outcome was measured with use of the Pediatric Outcomes Data Collection Instrument. These questionnaires were completed by the parents of all twenty patients and, in addition, by fifteen patients in the study who were between the ages of eleven and eighteen years. Fracture and surgery rates were calculated on the basis of the number of documented fractures and surgical procedures that the patient had had from the time of the initial presentation until the time of the latest follow-up visit. RESULTS: There were significant relationships between the bone mineral density of the lumbar spine and the scores obtained on the parent-completed questionnaires with regard to upper-extremity functioning (r = 0.57, p < 0.01), transfers and basic mobility (r = 0.55, p = 0.01), sports and physical functioning (r = 0.55, p = 0.01), and global functioning (r = 0.60, p < 0.004). There were also significant relationships between the bone mineral density of the wrist and the scores obtained on the child-completed questionnaires with regard to upper-extremity functioning (r = 0.82, p < 0.01), sports and physical functioning (r = 0.76, p < 0.01), and global functioning (r = 0.83, p = 0.001). There were significant negative relationships between the bone mineral density of the lumbar spine and the rate of fractures (r = -0.69, p < 0.001) and the bone mineral density of the lumbar spine and the rate of surgery (r = -0.60, p < 0.01). CONCLUSIONS: There is a relationship between bone mineral density and the functional outcome, rate of fracture, and rate of surgery in patients with osteogenesis imperfecta. Bone mineral density appears to be an indicator of disease severity and may be predictive of long-term functional outcome. To establish specific guidelines for treatment, more data on normative bone-mineral density in children with osteogenesis imperfecta will be needed.

Adolescent↗
PubMed2006

Racial differences in health care use among medicare only and dual eligibles.

It has been an important financial issue in the U.S. Medicare expenditures that health care expenses of Medicaid-Medicare dual eligibles (MMDE) are much higher than those of Medicare only beneficiaries (MOB). This paper compares health care use and health status of MMDEs and MOBs who are either Afro-American or white recipients. Using total health care use information from the Medical Expenditure Panel Survey (MEPS) 2000, we find that the proportion of dual eligibles with chronic health conditions is higher by 4% than that of the Medicare only beneficiaries and that dual eligibles make more frequent uses of various health care services. The number of office-based physician visits and outpatient physician visits are higher for Afro-American dual eligibles than white dual eligibles. This finding seems to be contributed to by relatively high medical needs among dual eligibles. Higher utilization of agency-related home health services among Afro-American dual eligibles than among white dual eligibles is considered as a consequence of different ethnicity-specific responses to insurance coverage.

Aged↗
PubMed1996

Postmenopausal bone mineral density: relationship to calcium intake, calcium absorption, residual estrogen, body composition, and physical activity.

Physical and lifestyle data were collected from 62 postmenopausal women who had declined hormone replacement therapy. Potential predictor variables were examined for their associations with bone mineral density (BMD) of the lumbar spine and femoral neck as assessed by dual x-ray absorptiometry. Body weight demonstrated the strongest association with lumbar BMD; lean body mass demonstrated the strongest association with femoral BMD. Together with the natural logarithm of the number of years since menopause (ln YSM) these anthropometric variables explained 36 and 34% of the variability of femoral and lumbar BMD, respectively. Serum estradiol levels demonstrated a weak positive association with BMD, which lost statistical significance after adjustment for body mass. Similarly, cardiovascular fitness was positively associated with femoral BMD prior to but not following adjustment for body mass. Controlling for years since menopause and body mass, the product of dietary calcium and calcium absorption demonstrated a weak positive correlation with femoral BMD (partial r = 0.30). The intake of tea was positively and significantly associated with both bone density measurements. In multiple regression analysis, femoral BMD was best explained by the lean body mass, ln YSM, and the daily intake of tea (r2 = 0.50). Similarly, lumbar BMD was best explained by body weight, ln YSM, and intake of tea (r2 = 0.44). Body mass is a major predictor of postmenopausal bone density at the hip and spine. A positive association between dietary calcium and BMD was detected only by taking into account the intestinal absorptive efficiency.

Absorption↗
PubMed1998

The effects of a high-protein, low-fat, ketogenic diet on adolescents with morbid obesity: body composition, blood chemistries, and sleep abnormalities.

OBJECTIVE: To evaluate the efficacy and metabolic impact of a high-protein, low-carbohydrate, low-fat ketogenic diet (K diet) in the treatment of morbidly obese adolescents with initial weights of >200% of ideal body weight. METHODS: Six adolescents, aged 12 to 15 years, weighing an average of 147.8 kg (range, 120.6-198.6 kg) and having an average body mass index of 50.9 kg/m (39.8-63.0 kg/m), consumed the K diet for 8 weeks. Daily intake consisted of 650 to 725 calories, which was substantively in the form of protein (80-100 g). The diet was very low in carbohydrates (25 g) and fat (25 g). This was followed by 12 weeks of the K diet plus two carbohydrates (30 g) per meal (K+2 diet). MAIN OUTCOME MEASURES: Anthropometric data and blood and urine were collected at enrollment, during week 1, and at 4-week intervals throughout the course of the study. Resting energy expenditure was measured by indirect calorimetry. Body composition was estimated using dual-energy x-ray absorptiometry, bioelectrical impedance analysis, and urinary creatinine excretion at enrollment and on completion of each phase of the diet. Nocturnal polysomnography and multiple sleep latency testing were conducted at baseline and repeated after an average weight loss of 18.7 kg to determine sleep architecture, frequency and duration of apneas, and daytime sleepiness. RESULTS: Subjects lost 15.4 +/- 1.4 kg (mean +/- SEM) during the K diet and an additional 2.3 +/- 2.9 kg during the K+2 diet. Body mass index decreased 5.6 +/- 0.6 kg/m(2) during the K diet and an additional 1.1 +/- 1.1 kg/m(2) during the K+2 diet. Body composition studies indicated that weight was lost equally from all areas of the body and was predominantly fat. Dual-energy x-ray absorptiometry showed a decrease from 51.1% +/- 2.1% body fat to 44.2% +/- 2.9% during the K diet and then to 41.6% +/- 4.5% during the K+2 diet. Lean body mass was not significantly affected. Weight loss was accompanied by a reduction in resting energy expenditure of 5.2 +/- 1.8 kcal/kg of fat-free mass per day. Blood chemistries remained normal throughout the study and included a decrease in serum cholesterol from 162 +/- 12 to 121 +/- 8 mg/dL in the initial 4 weeks of the K diet. An increase in calcium excretion was accompanied by a decrease in total-body bone mineral content. A paucity of rapid eye movement sleep and excessive slow-wave sleep were seen in all subjects at enrollment. Weight loss led to an increase in rapid eye movement sleep (P < .02) and a decrease in slow-wave sleep (P < .01) to near normal levels. CONCLUSIONS: The K diet can be used effectively for rapid weight loss in adolescents with morbid obesity. Loss in lean body mass is blunted, blood chemistries remain normal, and sleep abnormalities significantly decrease with weight loss.

Adolescent↗
PubMed2004

Kappa editing rescues autoreactive B cells destined for deletion in mice transgenic for a dual specific anti-laminin Ig.

We explored mechanisms involved in B cell self-tolerance in a double- and triple-transgenic mouse model bearing the LamH-C mu Ig H chain conventional transgene and a gene-targeted replacement for a functional V kappa 8J kappa 5 L chain gene. Whereas the H chain is known to generate anti-laminin Ig in combination with multiple L chains, the H + L Ig binds ssDNA in addition to laminin. Immune phenotyping indicates that H + L transgenic B cells are regulated by clonal deletion, receptor editing via secondary rearrangements at the nontargeted kappa allele, and anergy. Collectively, the data suggest that multiple receptor-tolerogen interactions regulate autoreactive cells in the H + L double-transgenic mice. Generation of H + LL triple-transgenic mice homozygous for the targeted L chain to exclude secondary kappa rearrangements resulted in profound B cell depletion with absence of mature B cells in the bone marrow. We propose that the primary tolerogen of dual reactive B cells in this model is not ssDNA, but a strongly cross-linking tolerogen, presumably basement membrane laminin, that triggers recombination-activating gene activity, L chain editing, and deletion.

Animals↗
PubMed1997

A virtual repository approach to clinical and utilization studies: application in mammography as alternative to a national database.

A national mammography database was proposed, based on a centralized architecture for collecting, monitoring, and auditing mammography data. We have developed an alternative architecture relying on Internet-based distributed queries to heterogeneous databases. This architecture creates a "virtual repository", or a federated database which is constructed dynamically, for each query and makes use of data available in legacy systems. It allows the construction of custom-tailored databases at individual sites that can serve the dual purposes of providing data (a) to researchers through a common mammography repository and (b) to clinicians and administrators at participating institutions. We implemented this architecture in a prototype system at the Brigham and Women's Hospital to show its feasibility. Common queries are translated dynamically into database-specific queries, and the results are aggregated for immediate display or download by the user. Data reside in two different databases and consist of structured mammography reports, coded per BIRADS Standardized Mammography Lexicon, as well as pathology results. We prospectively collected data on 213 patients, and showed that our system can perform distributed queries effectively. We also implemented graphical exploratory analysis tools to allow visualization of results. Our findings indicate that the architecture is not only feasible, but also flexible and scaleable, constituting a good alternative to a national mammography database.

Computer Communication Networks↗
PubMed1999

Removal of extracerebral tissues in dual-echo magnetic resonance images via linear scale-space features.

The location and masking of the brain and surrounding cerebrospinal fluid (CSF) in two-dimensional (2D) dual-echo fast spin-echo (FSE) magnetic resonance (MR) images of the head is achieved by an automated procedure with a voxel-based computational algorithm. Linear scale-space features are derived from the short-echo, proton-density (PD)-weighted images. The second-order Gaussian derivative (the Laplacian) operator is applied at three different spatial scales as a measure of image convexity/concavity with a first-order Gaussian derivative measure (the squared gradient) at a single scale used to circumscribe cortical regions. A mask obtained from the long-echo, T2-weighted image is used to remove extracerebral components of the visual system. A three-dimensional (3D) connectivity analysis then identifies the largest connected volume as the brain. Five dual-echo fast spin-echo images acquired by repeated scanning of the same normal volunteer were used to verify reproducibility; and coronal and axial acquisitions from another normal volunteer to demonstrate the method's robustness to data collected with non-cubic voxels. Images acquired from five individuals with Alzheimer's disease are also presented to show that the algorithm can be used in cases of non-normative anatomy. Validity is affirmed by demonstrating that cerebral volumes estimated by this method for all 12 images are highly correlated (R = 0.98) with estimates obtained by an expert human operator.

Algorithms↗
PubMed2004

Crossover of marital dissatisfaction during military downsizing among Russian army officers and their spouses.

This study examined mechanisms of strain crossover within couples and the moderating role of gender. Data were collected at a time of military downsizing from a sample of 1,250 Russian army officers and their spouses. The authors tested a model that incorporated 3 mechanisms for the crossover of marital dissatisfaction among dual-earner couples. The model provided support for 2 suggested crossover mechanisms: direct reactions of crossover and indirect mediated effects through social undermining. Strong evidence was also provided for gender asymmetry in the crossover process. Marital dissatisfaction crossed over from husbands to wives but not vice versa, and social undermining behavior played a role in the process of crossover of marital dissatisfaction for husbands but not for wives.

Adult↗
PubMed2004

Muscle strength in obese elderly women: effect of recreational physical activity in a cross-sectional study.

BACKGROUND: Muscle strength (MS) may be impaired in obese persons, and this impairment may be a consequence of both obesity and low physical fitness. OBJECTIVE: We investigated whether MS differed between obese [body mass index (BMI; in kg/m2 > 29], normal-weight (BMI = 24-29), and lean (BMI < 24) elderly subjects and compared the MS of sedentary and active subjects according to their BMI group. DESIGN: The study included 215 obese [ (+/- SD) age: 80.0 +/- 3.5 y; BMI: 31.9 +/- 2.6], 630 normal-weight (age: 80.2 +/- 3.7 y; BMI: 26.3 +/- 1.4), and 598 lean (age: 80.7 +/- 3.5 y; BMI: 21.6 +/- 1.8) women with good functional ability. A cross-sectional design was used. Anthropometric measures (weight, height); measures of appendicular skeletal muscle mass (by dual-energy X-ray absorptiometry), isometric knee and elbow extension (by statergometer), and isometric handgrip strength (by dynamometer); and data on health status and self-reported recreational physical activity (RPA: walking, gymnastics, cycling, swimming, gardening) were collected. RESULTS: Absolute (unadjusted) MS was higher in obese than in lean women (P < 0.01), except for handgrip strength (P > 0.05). When adjusted for age, height, RPA, pain, depression, and appendicular skeletal muscle mass, MS did not differ significantly between obese, normal-weight, and lean subjects, except for knee extension (significant interaction effect with RPA; P = 0.01). With increasing BMI, lower limb strength did not change in the sedentary women but increased in active (> or = 1 h/wk in > or = 1 RPA for > or = 1 mo) women. All adjusted MS measures in active participants were significantly higher (P < 0.001) than those in their sedentary peers. CONCLUSION: The adjusted MS of elderly women is not associated with obesity but is higher in active subjects than in sedentary ones, especially in the lower limbs of obese subjects.

Aged↗