bluuebunny/crossref_metadata_2025_split huggingface dataset:
CELL AGGREGATION OF THE CYANOBACTERIUM SYNECHOCOCCUS ELONGATUS: ROLE OF THE ELECTRON TRANSPORT CHAIN
Authors: Koblížek Michal , Komenda Josef , Masojídek Jiří , Pechar Libor 
Published: March 2003

Cell aggregation, the formation of irregular clusters of individual cells or filaments, is frequently observed in many cyanobacterial species. The mechanism(s) and potential causes of cell aggregation were studied in a thermophilic strain of the unicellular cyanobacterium Synechococcus elongatus Näg. We found that cell aggregation occured as the natural response of a healthy, well‐growing culture to a sudden increase in irradiance. We propose that aggregation represents a fast (time scale in minutes), light‐adapting mechanism, affected by both light quality and the presence of substances altering photosynthetic electron transfer. Our data suggest an involvement of electron transfer downstream of PSI, with reactive oxygen species triggering the signal. Aggregation was an ATP‐independent process and did not require de novo protein synthesis. We suggest a specific role of glutathione in this process based on its ability to induce aggregation in the dark.
Systematics of Coccoid Green Algae: Morphology vs. 18S rRNA Gene Phylogeny
Authors: Krienitz L. , Wolf M. , Hegewald E. , Hepperle D. 
Published: March 2003

AbstractClassical approaches using morphological characters for the circumscription of taxa in coccoid green algae do not adequately reflect the phylogenetic relationships. Phylogenetic trees based on 18S rRNA gene sequence analysis provide new insights into the systematics of these algae. We give a review and discuss the content of orders of coccoid green algae and evaluate the usefulness of some traditionally used diacritic features. Whereas the content of the orders Chlorococcales and Chlorellales needs to be reduced, the order Sphaeropleales comprises more families than in the traditional circumscription. According to molecular biological investigations the Neochloridaceae, Selenastraceae and Scenedesmaceae formerly classified in the Chlorococcales and later into the Chlorellales belong to the Sphaeropleales. The Hydrodictyaceae, formerly a member of the Protosiphonales, are also to be grouped in the Sphaeropleales. Some members of the Ulotrichales, which propagate by binary fission (e.g. Nannochloris and Catena) cluster together with autosporine coccoid taxa within the Trebouxiophyceae. With the example of members of the Selenastraceae, Oocystaceae and Chlorellacea it is shown that the morphology of cells as well as the formation of coenobia, spines, mucilage and incrustations cannot be used to separate genera.
A Traffic Sign Recognition Test Can Discriminate Between Older Drivers Who Have and Have Not Had a Motor Vehicle Crash
Authors: MacGregor Jan M. , Freeman Daniel H. , Zhang Dong 
Published: March 2003

OBJECTIVES:To determine whether a Traffic Sign Recognition Test (TSRT) can identify older drivers who recently had a motor vehicle crash (MVC).DESIGN:Retrospective, matched, case‐control study.SETTING:Licensed drivers in Galveston, Texas.PARTICIPANTS:60 crash and 60 control subjects matched for age and gender. Cases were identified from accident records. Controls were selected from a randomized list of licensed drivers in Galveston.MEASUREMENTS:Folstein Mini‐Mental State Examination (MMSE) and the TSRT.RESULTS:A TSRT significantly distinguished between case and control groups (P= .01). The MMSE did not (P= .61). A TSRT predicted MVC in a multivariate analysis controlling for education, MMSE score, race/ethnicity, and mileage driven/year (odds ratio = 0.88, 95% confidence interval = 0.77–1.00).CONCLUSION:A TSRT successfully identifies older drivers with a recent MVC, but the test lacks sensitivity and specificity. A prospective study is needed to further delineate the TSRT's usefulness in predicting crash risk in older drivers.
Dependence in Activities of Daily Living and Cognitive Impairment Strongly Predicted Mortality in Older Urban Residents in Brazil: A 2‐Year Follow‐Up
Authors: Ramos Luiz R. , Simoes Eduardo J. , Albert Marilyn S. 
Published: March 2003

OBJECTIVES:To identify a set of predictors of mortality among residents in the community, before any physical, biochemical, or image examination is performed, that could be collected on a routine standardized basis, to help the clinician define a patient follow‐up strategy and the health planner make decisions regarding the care of older people.DESIGN:A household follow‐up study, with an evaluation at baseline and 2 years later.SETTING:Residential area, with a low rate of in‐ and outmigration, in Sao Paulo, a large industrialized urban center in southeastern Brazil.PARTICIPANTS:One thousand six hundred sixty‐seven older urban residents in the community (65+), from different socioeconomic backgrounds, enrolled after a study area census.INTERVENTION:Structured home interview with Brazilian Older Americans Resources and Services Multidimensional Functional Assessment Questionnaire, previously validated in Portuguese.MEASUREMENTS:A logistic regression model for the risk of dying in the period was developed, having as independent variables, sociodemographic characteristics plus six other dimensions: subjective self‐evaluation of health, past medical history, use of health services, dependence in activities of daily living (ADLs), mental health, and cognitive status.RESULTS:There were 146 deaths (9%) in the cohort during the follow‐up interval. The variables that appeared as independent predictors of death in the final logistic regression model were: gender (relative risk (RR) = 2.8 (males)), age (RR = 2.0 (80+ vs. 65–69)), hospitalization in the previous 6 months (RR = 2.4 (at least one)), dependence in ADLs (RR = 3.0 (assistance required for 7 vs. 0 ADLs)); and cognitive impairment (RR = 1.9 (Mini‐Mental State Examination 18 vs. 30)).CONCLUSION:These findings suggest that in developing countries such as Brazil, an assessment of dependence in daily living and cognitive status should be an essential part of any health evaluation of an older person, not only because these variables represent potentially high independent mortality risks, but also because they can be easily and reliably assessed, using well‐validated instruments, and may be susceptible to intervention. J Am Geriatr Soc 49:1168–1175, 2001.
The Vulnerable Elders Survey: A Tool for Identifying Vulnerable Older People in the Community
Authors: Saliba Debra , Elliott Marc , Rubenstein Laurence Z. , Solomon David H. , Young Roy T. , Kamberg Caren J. , Carol Roth RN , MacLean Catherine H. , Shekelle Paul G. , Sloss Elizabeth M. , Wenger Neil S. 
Published: March 2003

OBJECTIVES: To develop a simple method for identifying community‐dwelling vulnerable older people, defined as persons age 65 and older at increased risk of death or functional decline. To assess whether self‐reported diagnoses and conditions add predictive ability to a function‐based survey.DESIGN: Analysis of longitudinal survey data.SETTING: A nationally representative community‐based survey.PARTICIPANTS: Six thousand two hundred five Medicare beneficiaries age 65 and older.MEASUREMENTS: Bivariate and multivariate analyses of the Medicare Current Beneficiary Survey; development and comparison of scoring systems that use age, function, and self‐reported diagnoses to predict future death and functional decline.RESULTS: A multivariate model using function, self‐rated health, and age to predict death or functional decline was only slightly improved when self‐reported diagnoses and conditions were included as predictors and was significantly better than a model using age plus self‐reported diagnoses alone. These analyses provide the basis for a 13‐item function‐based scoring system that considers age, self‐rated health, limitation in physical function, and functional disabilities. A score of ≥3 targeted 32% of this nationally representative sample as vulnerable. This targeted group had 4.2 times the risk of death or functional decline over a 2‐year period compared with those with scores <3. The receiver operating characteristics curve had an area of .78. An alternative scoring system that included self‐reported diagnoses did not substantially improve predictive ability when compared with a function‐based scoring system.CONCLUSIONS: A function‐based targeting system effectively and efficiently identifies older people at risk of functional decline and death. Self‐reported diagnoses and conditions, when added to the system, do not enhance predictive ability. The function‐based targeting system relies on self‐report and is easily transported across care settings.
Preventing Injuries in Older People by Preventing Falls: A Meta‐Analysis of Individual‐Level Data
Authors: Robertson M. Clare , Campbell A. John , Gardner Melinda M. , Devlin Nancy 
Published: March 2003

OBJECTIVES: Our falls prevention research group has conducted four controlled trials of a home exercise program to prevent falls in older people. The objectives of this meta‐analysis of these trials were to estimate the overall effect of the exercise program on the numbers of falls and fall‐related injuries and to identify subgroups that would benefit most from the program.DESIGN: We pooled individual‐level data from the four trials to investigate the effect of the program in those aged 80 and older, in those with a previous fall, and in men and women.SETTING: Nine cities and towns in New Zealand.PARTICIPANTS: One thousand sixteen community dwelling women and men aged 65 to 97.INTERVENTION: A program of muscle strengthening and balance retraining exercises designed specifically to prevent falls and individually prescribed and delivered at home by trained health professionals.MEASUREMENTS: Main outcomes were number of falls and number of injuries resulting from falls during the trials.RESULTS: The overall effect of the program was to reduce the number of falls and the number of fall‐related injuries by 35% (incidence rate ratio (IRR) = 0.65, 95% confidence interval (CI) = 0.57–0.75; and, respectively IRR = 0.65, 95% CI = 0.53–0.81.) In injury prevention, participants aged 80 and older benefited significantly more from the program than those aged 65 to 79. The program was equally effective in reducing fall rates in those with and without a previous fall, but participants reporting a fall in the previous year had a higher fall rate (IRR = 2.34, 95% CI = 1.64–3.34). The program was equally effective in men and women.CONCLUSION: This exercise program was most effective in reducing fall‐related injuries in those aged 80 and older and resulted in a higher absolute reduction in injurious falls when offered to those with a history of a previous fall.
Deaths Between Bedrails and Air Pressure Mattresses
Authors: Miles Steven H. 
Published: March 2003

OBJECTIVES: To describe how patients die by becoming trapped between therapeutic air pressure mattresses and bed rails.DESIGN: A retrospective review of all voluntary reports deaths in beds with air mattresses that can be found in the Food and Drug Administration's on‐line databases of adverse medical events that cover 1994 to 2001.SETTING: Death reports come from manufacturers, medical staff, and coroners and describe deaths in hospitals, nursing homes, and home care, although type of care site is often not given.MEASUREMENTS: Event descriptions were reviewed to determine how the person became entrapped in the rail and how responsibility for the event was allocated.RESULTS: There were 35 deaths involving many product lines. Twenty‐one deaths involved overlay air mattresses placed on top of a regular mattress. Thirteen patients died in beds with built‐in air mattresses. Compression of the mattress allowed an off‐center person to slide against the rail where reexpansion of the mattress kept the person compressed against the rail. Two patterns were seen. In one, the mattress bunched up behind a person who was lying on the side of the bed, pushing the neck against a bedrail. In the second type, a patient died after sliding off the bed and having the neck or chest compressed between the rail and bed. Manufacturers attributed the deaths to poor clinical decision‐making or inadequate monitoring.CONCLUSIONS: Lethal asphyxiation in beds with air pressure mattresses is a variant of bedrail‐mattress entrapment that requires redesign by bed manufacturers and risk awareness by clinicians.
Handgrip Strength and Mortality in Older Mexican Americans
Authors: Al Snih Soham , Markides Kyriakos S. , Ray Laura , Ostir Glenn V. , Goodwin James S. 
Published: March 2003

OBJECTIVES: To examine the association between handgrip strength and mortality in older Mexican American men and women.DESIGN: A 5‐year prospective cohort study.SETTING: Five southwestern states: Texas, New Mexico, Colorado, Arizona, and California.PARTICIPANTS: A population‐based sample of 2,488 noninstitutionalized Mexican‐American men and women aged 65 and older.MEASUREMENTS: Maximal handgrip strength, timed walk, and body mass index were assessed at baseline during 1993/94. Self‐reports of functional disability, various medical conditions, and status at follow‐up were obtained.RESULTS: Of the baseline sample with complete data, 507 persons were confirmed deceased 5 years later. Average handgrip strength ± standard deviation was significantly higher in men (28.4 kg ± 9.5) than in women (18.2 kg ± 6.5). Of men who had a handgrip strength less than 22.01 kg and women who had a handgrip strength less than 14 kg, 38.2% and 41.5%, respectively, were dead 5 years later. In men in the lowest handgrip strength quartile, the hazard ratio of death was 2.10 (95% confidence interval (CI) = 1.31–3.38) compared with those in the highest handgrip strength quartile, after controlling for sociodemographic variables, functional disability, timed walk, medical conditions, body mass index, and smoking status at baseline. In women in the lowest handgrip strength quartile, the hazard ratio of death was 1.76 (95% CI = 1.05–2.93) compared with those in the highest handgrip strength quartile. Poorer performance in the timed walk and the presence of diabetes mellitus, hypertension, and cancer were also significant predictors of mortality 5 years later.CONCLUSION: Handgrip strength is a strong predictor of mortality in older Mexican Americans, after controlling for relevant risk factors.
The Effect of Cardiovascular and Osteoarticular Diseases on Disability in Older Italian Men and Women: Rationale, Design, and Sample Characteristics of the Progetto Veneto Anziani (PRO.V.A.) Study
Authors: Corti Maria‐Chiara , Guralnik Jack M. , Sartori Leonardo , Baggio Giovannella , Manzato Enzo , Pezzotti Patrizio , Barbato GianMaria , Zambon Sabina , Ferrucci Luigi , Minervini Sergio , Musacchio Estella , Crepaldi Gaetano 
Published: March 2003

OBJECTIVES: Describe the methodology and preliminary results of the Progetto Veneto Anziani (PRO.V.A.) Study, an observational study of the Italian population aged 65 and olderDESIGN: Cross‐sectional cohort observation.SETTING: Northern Italy.PARTICIPANTS: Italians aged 65 and older, living in both the community and nursing homes.MEASUREMENTS: At baseline, participants were interviewed at their homes and subsequently examined by nurses and physicians at the two study clinics using an extensive battery of clinical, instrumental, biochemical, and physical performance tests. Hand, knee, hip, and chest x‐rays and bone densitometry were performed in 92% of the participants, and 99% of the participants consented to blood drawing and deoxyribonucleic acid analyses. The physician who performed the physical examination determined disease presence based on several components of the interview and examination. A further, comprehensive determination was performed with standardized algorithms using all the information collected on each participant, including hospital records surveillance, standardized x‐ray readings, and blood assays. In one of the study sites, a brain magnetic resonance imaging was performed in a subsample of the participants (820 persons).RESULTS: Overall response rate to the baseline clinic visit was 77% for men and 64% for women. Co‐presence of at least one cardiovascular disease (CVD) and at least one osteoarticular disease (OAD) was identified in 10%, 22%, and 29% of men and 9%, 24%, and 40% of women aged 65 to 74, 75 to 84, and 85 and older, respectively. Overall, the mean number of coexisting chronic conditions was 1.8 for men and 2.4 for women.CONCLUSIONS: The PRO.V.A. study has the potential to provide an original contribution to clarify the mechanisms whereby diseases cause disability in older men and women; the particular focus on CVD and OADs will make it possible to comprehensively evaluate the development of disability as it relates to these two important conditions.
Physical Activity as a Determinant of Change in Mobility Performance: The Longitudinal Aging Study Amsterdam
Authors: Visser Marjolein , Pluijm Saskia M. F. , Stel Vianda S. , Bosscher Ruud J. , Deeg Dorly J. H. 
Published: March 2003

OBJECTIVES: This study examined the association of (change in) physical activity and decline in mobility performance in older men and women.DESIGN: A 3‐year prospective study using data of the Longitudinal Aging Study.SETTING: Netherlands.PARTICIPANTS: Two thousand one hundred nine men and women aged 55 to 85.MEASUREMENTS: Total physical activity (expressed as hours per day and kilocalories per day) and sports participation were measured using a validated, interviewer‐administered questionnaire. Mobility performance was assessed using two timed tests: 6‐meter walk and repeated chair stands.RESULTS: Mobility performance declined for 45.6% of the sample. At baseline, the mean time ± standard deviation spent on total physical activity was 3.0 ± 2.1 h/d or 719 ± 543 kcal/d, and 56.6% of the sample participated in sports. Sports participation and a higher level of total physical activity, walking, or household activity were associated with a smaller mobility decline. After 3 years, total physical activity declined, and only 53.4% of those reporting sports at baseline continued doing so. Continuation of physical activity over time was associated with the smallest decline in mobility. The observed associations were similar for those with and without chronic disease (P> 0.3). The conclusions did not change after adjustment for potential confounders, including demographic and lifestyle variables, depression, and cognitive status.CONCLUSIONS: Physical activity, and especially a regularly active lifestyle, may slow the decline in mobility performance. A beneficial effect was observed for sports and nonsports activities, independent of the presence of chronic disease.
Is There a Relationship Between Fat‐Free Soft Tissue Mass and Low Cognitive Function? Results From a Study of 7,105 Women
Authors: Nourhashémi Fati , Andrieu Sandrine , Gillette‐Guyonnet Sophie , Reynish Emma , Albarède Jean‐Louis , Grandjean Hélène , Vellas Bruno 
Published: March 2003

OBJECTIVES: To test the hypothesis that low fat‐free soft tissue mass and cognitive impairment are independently associated.DESIGN: Cross‐sectional study.SETTING: Five geographic areas of France.PARTICIPANTS: Seven thousand one hundred five community‐dwelling women aged 75 and older recruited from electoral rolls between 1992 and 1994.MEASUREMENTS: Fat‐free soft tissue mass, body fat mass, and bone mineral density were measured using dual‐energy x‐ray absorptiometry. Study participants were assessed for cognitive impairment using the Short Portable Mental Status Questionnaire and divided into two groups according to their scores. Logistic regression models were used to calculate multivariate‐adjusted differences in body composition between two groups of subjects according to their cognitive function.RESULTS: After adjustment for confounders, compared with women in the highest quartile of fat‐free soft tissue mass, women in the lowest quartile had an odds ratio of 1.43 (95% confidence interval (CI) = 1.07–1.91) for cognitive impairment. Low fat mass was also associated with lower cognitive function, with an odds ratio of 1.35 (95% CI = 1.01–1.79) for the lower quartile of fat mass compared with the highest quartile. There was no association between cognitive impairment and bone mineral density.CONCLUSIONS: This finding supports the hypothesis that low muscle mass is associated with cognitive impairment in older women. These two components represent major causes of frailty and functional decline in older people and could have some common mechanisms. Nevertheless, these results do not predict the causal variable.
Use of Lipid‐Lowering Drugs in Older Adults With and Without Dementia: A Community‐Based Epidemiological Study
Authors: Rodriguez Eric G. , Dodge Hiroko H. , Birzescu Maria A. , Stoehr Gary P. , Ganguli Mary 
Published: March 2003

OBJECTIVES: To compare the use of lipid‐lowering drugs in community‐dwelling older adults with and without dementia.DESIGN: Comparison of lipid‐lowering drug use by demented cases and nondemented controls based on secondary analysis of data from a longitudinal epidemiologic study.SETTING: Longitudinal study of a largely rural, low‐ socioeconomic‐status, community‐based cohort of older persons residing in the mid‐Monongahela Valley of South‐west Pennsylvania (the Monongahela Valley Independent Elders Survey).PARTICIPANTS: Eight hundred forty‐five individuals of mean ± standard deviation (SD) age of 80.5 ± 4.6, participating in the fifth biennial wave of data collection.MEASUREMENTS: Demographics; medical history; medication regimen (including examination of prescription bottle labels); self‐report of most recent visit to primary care physician (PCP); and standardized clinical assessment to determine presence of dementia, including Clinical Dementia Rating (CDR).RESULTS: One hundred seventy participants (20.1% of total subject cohort) had dementia, with a CDR of 0.5 or greater. Mean ages of demented and nondemented individuals were 83.5 ± 5.1 and 79.8 ± 4.2, respectively. Similar proportions, 87.7% and 89.5%, of these groups reported PCP visits in the previous year. Of the total sample, 9.4% (3.5% of the demented and 10.8% of the nondemented) were taking lipid‐lowering drugs. After adjustment for age, sex, education, visit with PCP within the past year, and potential confounding clinical and lifestyle variables (self‐reported heart disease, stroke or transient ischemic attacks, hypertension, smoking, and alcohol consumption), dementia was associated with a lower likelihood of taking a lipid‐lowering drug (odds ratio = 0.39, 95% confidence interval = 0.16–0.95). In post hoc subgroup analyses, similar results were found when restricting lipid‐lowering drugs to statins alone but were not statistically significant. Drug use was not associated with severity of dementia (CDR = 0.5 vs CDR ≥ 1).CONCLUSIONS: Demented individuals were less likely than their nondemented counterparts to be taking lipid‐lowering drugs. This finding could reflect different prescribing patterns by physicians for demented and nondemented patients or a possible protective effect of these drugs against dementia.