bluuebunny/crossref_metadata_2025 huggingface dataset:
GRAZER‐INDUCED COLONY FORMATION IN SCENEDESMUS ACUTUS (CHLOROPHYCEAE): ECOMORPH EXPRESSION AT DIFFERENT TEMPERATURES
Authors: Lürling M. , Van Donk E.
Published: March 2003

Scenedesmus acutus Meyen was cultured at four temperatures (9.5°, 16.5°, 24°, and 29° C) in standard medium or in medium with filtered water from a Daphnia culture. Growth was significantly reduced at low temperatures. At 9.5° C it took more than a week before formation of eight‐celled coenobia occurred in both the absence and presence of water from a Daphnia culture. At higher temperatures, formation of four‐ and eight‐celled coenobia occurred more rapidly and was already observed in the presence of Daphnia water within 2 days. As cultures aged, also in the absence of Daphnia water, four‐celled coenobia became dominant. At cold temperature, cell volume initially was significantly larger but declined after 3–4 weeks. Grazer‐induced colony formation had occurred independent of the incubation temperature, but the number of cells per colony was increased with declining temperature. The morphological expression may be interpreted as a cyclomorphosis driven by nutrients, temperature, and chemical cues from grazers.
DNA PROBES AND A RECEPTOR‐BINDING ASSAY FOR DETECTION OF PSEUDO‐NITZSCHIA (BACILLARIOPHYCEAE) SPECIES AND DOMOIC ACID ACTIVITY IN CULTURED AND NATURAL SAMPLES
Authors: Scholin Christopher A. , Marin Roman , Miller Peter E. , Doucette Gregory J. , Powell Christine L. , Haydock Paul , Howard Judith , Ray Jason
Published: March 2003

Large‐subunit ribosomal RNA‐targeted probes for Pseudo‐nitzschia australis Frenguelli, P. multiseries (Hasle) Hasle, P. pseudodelicatissima (Hasle) Hasle, and P. pungens (Grunow) Hasle were applied to cultured and natural samples using whole‐cell and sandwich hybridization. Testing of the latter method is emphasized here, and technique refinements that took place during 1996–1997 are documented. Application of the sandwich hybridization test showed that the signal intensity obtained for a given number of target cells remained constant as batch cultures of these organisms progressed from active through stationary growth phases. This suggests that cellular rRNA content for each target species remained relatively stable despite changes in growth state. Application of whole‐cell and sandwich hybridization assays to natural samples showed that both methods could be used to detect wild P. australis, P. pseudodelicatissima, and to a lesser degree P. multiseries, but detection of P. pungens was prone to error. A receptor‐binding assay for domoic acid (DA) enabled detection of this toxin activity associated with a particulate fraction of the plankton and provided a context in which to view results of the rRNA probe tests. In one case, the probe for P. australis cross‐reacted with P. cf. delicatissima. The sample that contained the latter species also contained a low amount of DA activity. Under certain field conditions, results of whole‐cell and sandwich hybridization tests disagreed. Detailed analysis of selected field samples illustrates how such situations arose. Collectively, the rRNA probe and toxin analyses suggest that manifestation of DA in the environment is possible in the absence of readily recognizable intact cells.
Chlamydomonas flagella
Authors: Mitchell David R.
Published: March 2003

Chlamydomonas reinhardtii Dangard has been widely adopted as a model system for studies of eukaryotic cilia and flagella. Here I review recent progress in understanding flagellar ultrastructure, the mechanisms that generate and regulate flagellar beating and gliding motility, the flagellar assembly process, basal body structure and function, and adhesion‐based signaling, all advanced by work with this single‐celled organism.
ULTRASTRUCTURE OF GYMNODINIUM AUREOLUM (DINOPHYCEAE): TOWARD A FURTHER REDEFINITION OF GYMNODINIUM SENSU STRICTO
Authors: Hansen Gert
Published: March 2003

Examination of the ultrastucture of the unarmored dinoflagellate Gymnodinium aureolum (Hulburt) G. Hansen (syn: Gyrodinium aureolum Hulburt) revealed the presence of nuclear chambers, which are specialized differentiations of the nuclear envelope, similar to those described in the type species of Gymnodinium, G. fuscum (Ehrenberg) Stein and certain other Gymnodinium species. The nuclear pores were restricted to these chambers. In the flagellar apparatus a nuclear fibrous connective linked the longitudinal microtubular root and the nucleus. This structure had so far been observed only in Gymnodinium spp. and in the heterotrophic species Actiniscus pentasterias (Ehrenberg) Ehrenberg, Nematodinium armatum (Dogiel) Kofoid et Swezy and Polykrikos kofoidii Chatton. Another unusual feature of G. aureolum was the presence of a striated fiber in the longitudinal flagellum, a feature previously only found in Ceratium furca (Ehrenberg) Claparède et Lachmann and C. tripos (O.F. Müller) Nitzsch. Gymnodinium aureolum also possessed a prominent ventral protrusion associated with the peduncle and containing electron opaque material. It is concluded that G. aureolum belongs to the Gymnodinium sensu stricto group. This may be a temporary classification, however, because G. aureolum and its allies differ from the type species G. fuscum by the presence of a transverse striated root, striated collars, trichocysts, and a peduncle.
EFFECTS OF CO2 ENRICHMENT ON THE BLOOM‐FORMING CYANOBACTERIUM MICROCYSTIS AERUGINOSA (CYANOPHYCEAE): PHYSIOLOGICAL RESPONSES AND RELATIONSHIPS WITH THE AVAILABILITY OF DISSOLVED INORGANIC CARBON1
Authors: Qiu Baosheng , Gao Kunshan
Published: March 2003

Microcystis aeruginosa Kütz. 7820 was cultured at 350 and 700 μL·L−1 CO2 to assess the impacts of doubled atmospheric CO2 concentration on this bloom‐forming cyanobacterium. Doubling of CO2 concentration in the airflow enhanced its growth by 52%–77%, with pH values decreased and dissolved inorganic carbon (DIC) increased in the medium. Photosynthetic efficiencies and dark respiratory rates expressed per unit chl a tended to increase with the doubling of CO2. However, saturating irradiances for photosynthesis and light‐saturated photosynthetic rates normalized to cell number tended to decrease with the increase of DIC in the medium. Doubling of CO2 concentration in the airflow had less effect on DIC‐saturated photosynthetic rates and apparent photosynthetic affinities for DIC. In the exponential phase, CO2 and HCO3− levels in the medium were higher than those required to saturate photosynthesis. Cultures with surface aeration were DIC limited in the stationary phase. The rate of CO2 dissolution into the liquid increased proportionally when CO2 in air was raised from 350 to 700 μL·L−1, thus increasing the availability of DIC in the medium and enhancing the rate of photosynthesis. Doubled CO2 could enhance CO2 dissolution, lower pH values, and influence the ionization fractions of various DIC species even when the photosynthesis was not DIC limited. Consequently, HCO3− concentrations in cultures were significantly higher than in controls, and the photosynthetic energy cost for the operation of CO2 concentrating mechanism might decrease.
BIOSYNTHESIS OF EICOSAPENTAENOIC ACID (EPA) IN THE FRESHWATER EUSTIGMATOPHYTE MONODUS SUBTERRANEUS (EUSTIGMATOPHYCEAE)1
Authors: Khozin‐Goldberg Inna , Didi‐Cohen Shoshana , Shayakhmetova Intyk , Cohen Zvi
Published: March 2003

In an attempt to elucidate the biosynthesis of the polyunsaturated fatty acid eicosapentaenoic acid (20:5ω3, EPA), we treated cultures of the eustigmatophyte Monodus subterraneus Peterson with either salicylhydroxamic acid or the herbicide SAN 9785. Labeled linoleic acid was incorporated into the cultures in the presence and absence of the latter inhibitor, and the redistribution of label was followed. Our results suggest that the major biosynthetic pathway leading to EPA involves fatty acids of the ω6 family. In the early stages of the biosynthesis, 18:1 is predominantly incorporated to the sn‐2 position of phosphatidylcholine, where it is stepwise desaturated by the Δ12 and Δ6 desaturases to 18:3ω6. The latter is released from the lipid, elongated to 20:3ω6 and reincorporated to both positions of phosphatidylethanolamine (PE) where it is further desaturated by the Δ5 and ω3 desaturases to EPA. We suggest that PE is the donor of the 20:5/20:5 diacylglycerol that is imported to the chloroplast to form the eukaryotic‐like molecular species of monogalactosyldiacylglycerol. Likewise, 20:3ω6 can be also incorporated into diacylglyceryltrimethylhomoserine, mostly to the sn‐2 position and similarly desaturated to 20:4ω6 and 20:5ω3. These fatty acids can be exported and incorporated into the sn‐1 position of the prokaryotic‐like molecular species of the chloroplastic lipids. We thus suggest that both the eukaryotic‐like and the prokaryotic‐like molecular species are biosynthesized by different extraplastidial lipids.
EFFECTS OF CELL DENSITY, TEMPERATURE, AND LIGHT INTENSITY ON GROWTH AND STALK PRODUCTION IN THE BIOFOULING DIATOM ACHNANTHES LONGIPES (BACILLARIOPHYCEAE)1
Authors: Lewis Raymond J. , Johnson Lisa M. , Hoagland Kyle D.
Published: March 2003

Achnanthes longipes Ag. is a marine stalk‐forming diatom that grows in dense biofilms. The effects of cell density, temperature, and light on growth and stalk production were examined in the laboratory to determine how they affected the ability of this diatom to form a biofilm. Stalk production abruptly increased when A. longipes was cultured at a density of 5.4 × 103 cells·mL−1, with a lag before stalk production occurring in cultures initiated at lower densities. Growth occurred at all temperatures from 8 to 32° C, with maximum growth at 26° C. Growth rate was light saturated at 60 μmol photons·m−2·s−1. Stalk production was determined as the proportion of cells producing stalks and stalk length in response to various temperatures and light intensities at high (5000 cells·mL−1) and low (500 cells·mL−1) densities. More cells formed stalks at high density, with no difference in stalk length. The proportion of cells producing stalks was maximal at 20° C, with little change at 17–32° C. Stalk length was at a maximum between 14 and 26° C. Stalk production showed little change in response to varying light intensity. The results of an earlier investigation on the effects of bromide concentration on stalk formation were expressed as the proportion of cells forming stalks and the lengths of the stalks. Both measures of stalk production varied with bromide concentration, with maximum values at 30 mM bromide. The increased stalk production at higher densities may be a means of elevating cells above the substrate to avoid competition in the dense biofilm.
MOLECULAR AND MORPHOLOGICAL DATA IDENTIFY A CRYPTIC SPECIES COMPLEX IN ENDOPHYTIC MEMBERS OF THE GENUS COLEOCHAETE BRÉB. (CHAROPHYTA: COLEOCHAETACEAE)1
Authors: Cimino Matthew T. , Delwiche Charles F.
Published: March 2003

The genus Coleochaete Bréb. is a relatively small group of freshwater microscopic green algae with about 15 recognized species. Although Coleochaete has long been considered to be a close relative of embryophytes, a comprehensive study of the genus has not been published since Pringsheim's 1860 monograph. As part of a systematic study of Coleochaete, we investigated four accessions of the genus that are morphologically similar to the endophytic species C. nitellarum Jost. Each of the four cultures was determined to be capable of endophytic growth in Nitella C. A. Agardh, a member of the closely related order Charales. Maximum likelihood and maximum parsimony analyses were performed on nucleotide data from the chloroplast genes atpB and rbcL that were sequenced from 16 members of the Coleochaetales and from other members of the Charophyceae, embryophytes, and outgroup taxa. These analyses indicate that the Coleochaetales are monophyletic and that the endophytic accessions are members of the scutata group of species. In addition, cell size and nucleotide data suggest that at least three different endophytic species may be represented. Herbivory, nutritional benefits, and substrate competition are three hypotheses that could explain the evolution and maintenance of the endophytic habit in Coleochaete. These data also imply that diversity in the genus may be markedly underestimated.
Alcohol Abuse, Cognitive Impairment, and Mortality Among Older People
Authors: Thomas Vince Salazar , Rockwood Kenneth J.
Published: March 2003

OBJECTIVES: To estimate the prevalence of alcohol abuse, the association of alcohol abuse with cognitive impairment, and the contribution of alcohol abuse to short‐term mortality in a cohort of older people screened for dementia.

DESIGN: Using the Canadian Study of Health and Aging (CSHA)—a representative, national cohort study of 10,268 older persons (≥65 years) from communities and long‐term care institutions conducted in 1991—alcohol abuse and dementia were diagnosed during clinical examinations. Death was determined by telephone interview 18 months after baseline and verified by vital statistics records.

SETTING: 36 regional community and 17 regional institutional populations in Canada.

PARTICIPANTS: The 2,873 individuals from the clinical sample of the CSHA.

MEASUREMENTS: Diagnosis of alcohol abuse (questionable, definite, none), diagnosis of dementia.

RESULTS: The prevalence of clinically detected definite alcohol abuse was 8.9% (95% confidence interval (CI) 7.9–9.9) and of questionable alcohol abuse was 3.7% (95% CI 3.0–4.4). Definite or questionable alcohol abuse was associated with a younger average age compared with no such abuse history, and men were significantly more likely than women to comprise definite and questionable diagnostic groups as compared with the group without alcohol abuse. The occurrence of all types of dementia except probable Alzheimer's disease was higher in those with definite or questionable alcohol abuse. Mortality at 18 months was higher among those with definite (14.8%, 95% CI 13.5–16.1) or questionable (20.0%, 95% CI 18.5–21.5) alcohol abuse, as compared with those with no alcohol abuse history (11.5%, 95% CI 10.3–12.7), and alcohol abuse (definite or questionable) conferred a 56% additional risk of short‐term mortality (odds ratio (OR) 1.56, 95% CI 1.11–2.20) after adjusting for age, sex, and a diagnosis of dementia.

CONCLUSIONS: Alcohol abuse among older people is common and occurs more frequently among men. It is associated with cognitive impairment and independently with short‐term mortality. Physician screening for alcohol abuse can yield a group of older people at risk for adverse health outcomes.
Reducing Delirium After Hip Fracture: A Randomized Trial
Authors: Marcantonio Edward R. , Flacker Jonathan M. , Wright R. John , Resnick Neil M.
Published: March 2003

DESIGN: Prospective, randomized, blinded.

SETTING: Inpatient academic tertiary medical center.

PARTICIPANTS: 126 consenting patients 65 and older (mean age 79 ± 8 years, 79% women) admitted emergently for surgical repair of hip fracture.

MEASUREMENTS: Detailed assessment through interviews with patients and designated proxies and review of medical records was performed at enrollment to ascertain prefracture status. Subjects were then randomized to proactive geriatrics consultation, which began preoperatively or within 24 hours of surgery, or “usual care.” A geriatrician made daily visits for the duration of the hospitalization and made targeted recommendations based on a structured protocol. To ascertain study outcomes, all subjects underwent daily, blinded interviews for the duration of their hospitalization, including the Mini‐Mental State Examination (MMSE), the Delirium Symptom Interview (DSI), and the Memorial Delirium Assessment Scale (MDAS). Delirium was diagnosed using the Confusion Assessment Method (CAM) algorithm.

RESULTS: The 62 patients randomized to geriatrics consultation were not significantly different (P> .1) from the 64 usual‐care patients in terms of age, gender, prefracture dementia, comorbidity, type of hip fracture, or type of surgical repair. Sixty‐one percent of geriatrics consultation patients were seen preoperatively and all were seen within 24 hours postoperatively. A mean of 10 recommendations were made throughout the duration of the hospitalization, with 77% adherence by the orthopedics team. Delirium occurred in 20  /62 (32%) intervention patients, versus 32  /  64 (50%) usual‐care patients (P = .04), representing a relative risk of 0.64 (95% confidence interval (CI) = 0.37–0.98) for the consultation group. One case of delirium was prevented for every 5.6 patients in the geriatrics consultation group. There was an even greater reduction in cases of severe delirium, occurring in 7/ 60 (12%) of intervention patients and 18  / 62 (29%) of usual‐care patients, with a relative risk of 0.40 (95% CI = 0.18–0.89). Despite this reduction in delirium, length of stay did not significantly differ between intervention and usual‐care groups (median ± interquartile range = 5 ± 2 days in both groups), likely because protocols and pathways predetermined length of stay. In subgroup analyses, geriatrics consultation was most effective in reducing delirium in patients without prefracture dementia or activities of daily living (ADL) functional impairment.

CONCLUSIONS: Proactive geriatrics consultation was successfully implemented with good adherence after hip‐fracture repair. Geriatrics consultation reduced delirium by over one‐third, and reduced severe delirium by over one‐half. Our trial provides strong preliminary evidence that proactive geriatrics consultation may play an important role in the acute hospital management of hip‐fracture patients.
Ethnic Differences in Mini‐Mental State Examination (MMSE) Scores: Where You Live Makes a Difference
Authors: Espino David V. , Lichtenstein Michael J. , Palmer Raymond F. , Hazuda Helen P.
Published: March 2003

OBJECTIVES: To examine differences in correlates of the Mini‐Mental State Examination (MMSE) in a population‐based sample of older Mexican Americans and European Americans and to provide empirical validation of the MMSE as an indicator of cognitive impairment in survey research in older Mexican Americans by comparing MMSE classification against performance on timed tasks with varying levels of cognitive demand.

DESIGN: A population‐based cross‐sectional study.

SETTING: Trained bilingual staff administered the MMSE as part of the San Antonio Longitudinal Study of Aging (SALSA) home‐based assessment battery.

PARTICIPANTS: 827 community‐dwelling Mexican Americans and European Americans, 65 and older, residing in three socioeconomically and culturally distinct neighborhoods (barrio, transitional, suburban).

MEASUREMENTS: The MMSE was compared against a variety of demographic, biomedical, and sociocultural variables ascertained by self‐report and against performance‐based measures of functional tasks representing varying levels of cognitive demand (Structured Assessment of Independent Living Skills (SAILS) subscales for food manipulation and money management).

RESULTS: Mexican Americans were 2.2 times more likely than European Americans to have MMSE scores <24. Multiple logistic regression analysis revealed that neighborhood was an independent predictor of low MMSE scores in Mexican Americans, with the relationship between ethnic group and MMSE explained by neighborhood. After adjusting for neighborhood type, no differences were noted between Mexican Americans and European Americans. Independent of other factors examined, low education was associated with low MMSE scores in both Mexican Americans and European Americans. Mexican Americans with MMSE scores <24 took significantly longer to complete four out of five performance‐based food manipulation tasks and all three money management tasks.

CONCLUSIONS: Neighborhood type was a predictor of cognitive impairment. Education affected MMSE scores similarly in both ethnic groups. MMSE scores <24, indicative of cognitive impairment, were uniformly associated with functional impairment in both the Mexican Americans and European Americans. Among older Mexican Americans, MMSE‐classified cognitive impairment was significantly associated with poorer performance on timed tasks with varying levels of cognitive demand independent of other correlates. A similar pattern of association was observed in European Americans. Thus, the MMSE appears to be a valid indicator of cognitive impairment in survey research in both older Mexican Americans and European Americans.
Associations of Demographic, Functional, and Behavioral Characteristics with Activity‐Related Fear of Falling Among Older Adults Transitioning to Frailty
Authors: Kressig Reto W. , Wolf Steven L. , Sattin Richard W. , O'Grady Michael , Greenspan Arlene , Curns Aaron , Kutner Michael
Published: March 2003

OBJECTIVES: To determine, in a cohort of older individuals transitioning to frailty (defined by Speechley and Tinetti, 1991) who have previously fallen, whether there are significant associations between demographic, functional, and behavioral characteristics and activity‐related fear of falling, using both the Falls Efficacy Scale (FES) and the Activities‐Specific Balance Confidence Scale (ABC).

DESIGN: Baseline cross‐sectional analysis in a prospective cohort intervention study.

SETTING: Twenty independent senior living facilities in Atlanta.

PARTICIPANTS: Seventeen male and 270 female subjects (n = 287), age 70 and older (mean ± standard deviation, 80.9 ± 6.2), with Mini‐Mental State Examination score ≥24, transitioning to frailty, ambulatory (with or without assistive device), medically stable, and having fallen in the past year.

MEASUREMENTS: Activity‐related fear of falling was evaluated with the FES and ABC Scale. Because of the comparable data derived from each scale, associations with functional measures‐related analyses were expressed using the latter. Depression was measured by Center for Epidemiological Studies Depression Scale. Functional measurements included timed 360° turn, functional reach test, timed 10‐meter walk test, single limb stands, picking up an object, and three chair stands.

RESULTS: No statistically significant association was found between activity‐related fear of falling and age. For the proposed activities, about half (ABC, 48.1%; FES, 50.1%) of the subjects were concerned about falling or showed lack of confidence in controlling their balance. A statistically significant inverse correlation was found between FES and ABC (r = −0.65; P < .001).

CONCLUSIONS: Activity‐related fear of falling was present in almost half of this sample of older adults transitioning to frailty. The significant association of activity‐related fear of falling with demographic, functional, and behavioral characteristics emphasizes the need for multidimensional intervention strategies to lessen activity‐related fear of falling in this population.
Healthcare Costs Associated with Percutaneous Endoscopic Gastrostomy Among Older Adults in a Defined Community
Authors: Callahan Christopher M. , Buchanan Nancy N. , Stump Timothy E.
Published: March 2003

OBJECTIVES:

The effectiveness of percutaneous endoscopic gastrostomy (PEG) in older adults remains controversial. Although prior studies have examined the safety of PEG and its impact on nutrition, there are limited data on the economic costs. The purpose of this study is to describe the healthcare costs associated with PEG tube feeding over 1 year.

DESIGN:

Prospective cohort study.

SETTING:

Small community of approximately 60,000 residents served by two hospital systems.

PARTICIPANTS:

One hundred five (70%) of 150 patients age 60 and older receiving PEG over a 24‐month period in the targeted community who permitted access to their medical records.

MEASUREMENTS:

Patients were interviewed at baseline and every 2 months for 1 year to obtain information on use of enteral formula, complication rates, and health services use. We obtained inpatient charge data for all hospitalizations and PEG procedures for 1 year.

RESULTS:

Censoring patients at death or 1 year post‐PEG, the mean number of days of PEG tube feeding was 180 (range 5–365). The average cost for PEG tube feeding for this cohort of patients was $7,488 (median $3,691) in 1997 and 1998. The average daily cost of PEG tube feeding was $87.21 (median $33.50). The estimated cost of providing 1 year of feeding via PEG is $31,832 (median $12,227). The main components of this cost include the initial PEG procedure (29.4%), enteral formula (24.9%), and hospital charges for major complications (33.4%).

CONCLUSIONS:

Direct charges associated with PEG tube feeding over 1 year are conservatively estimated at $31,832; there was considerable variation in charges because of the cost of rare but costly major complications. Also, feeding patients via PEG resulted in cost shifts in terms of the primary payor. The economic cost of PEG tube feeding is another consideration in decision making for long‐term enteral feeding among older adults. J Am Geriatr Soc 49:1525–1529, 2001.
Comparative Impact of Hearing and Vision Impairment On Subsequent Functioning
Authors: Wallhagen Margaret I. , Strawbridge William J. , Shema Sarah J. , Kurata John , Kaplan George A.
Published: March 2003

OBJECTIVES: The purpose of this study was to compare independent impacts of two levels of self‐reported hearing and vision impairment on subsequent disability, physical functioning, mental health, and social functioning.

DESIGN: A 1‐year prospective cohort study.

SETTING: San Francisco Bay Area, California.

PARTICIPANTS: Two thousand four hundred forty‐two community‐dwelling men and women age 50 to 102 from the Alameda County Study (California).

MEASUREMENTS: Hearing and vision impairment were assessed in 1994. Outcomes, measured in 1995, included physical disability (activities of daily living, instrumental activities of daily living, physical performance, mobility, and lack of participation in activities), mental health (self‐assessed, major depressive episode), and social functioning (feeling left out, feeling lonely, hard to feel close to others, inability to pay attention). All 1995 outcomes were adjusted for baseline 1994 values.

RESULTS: Both impairments had strong independent impacts on subsequent functioning. Vision impairment exerted a more wide‐ranging impact on functional status, ranging from physical disability to social functioning. However, the results also highlighted the importance of hearing impairment, even when mild.

CONCLUSIONS: These impairments can be partially ameliorated through prevention, assessment, and treatment strategies. Greater attention to sensory impairments by clinicians, patients, public health advocates, and researchers is needed to enhance functioning in older adults.
Healthcare Utilization and Costs in Managed Care Patients with Alzheimer's Disease During the Last Few Years of Life
Authors: McCormick Wayne C. , Hardy James , Kukull Walter A. , Bowen James D. , Teri Linda , Zitzer Sally , Larson Eric B.
Published: March 2003

OBJECTIVES: To learn whether managed care patients with Alzheimer's disease (AD) are more or less costly to care for than patients with other forms of dementia or patients without dementia during the last few years of life.

DESIGN: Case control study.

SETTING: A health maintenance organization base population.

PARTICIPANTS: Three groups of subjects (mean age 85) who were deceased members of a dementia registry obtained from a health maintenance organization base population: 263 subjects with clinically diagnosed probable AD, 133 subjects with other forms of dementia, and 100 cognitively intact controls.

MEASUREMENTS: Utilization records were examined for the 3 years preceding death.

RESULTS: In all subcategories and in aggregate, utilization and costs of care were either similar or lower for patients with AD than for the other groups, even after controlling for age, gender, and comorbidity.

CONCLUSIONS: Persons with AD do not incur higher costs than persons with other types of dementia or age‐matched persons without dementia in a mature health maintenance organization during the last few years of life, when utilization is likely to be highest.
Progressive Trends in the Prevalence of Benzodiazepine Prescribing in Older People in Ontario, Canada
Authors: Tu Karen , Mamdani Muhammad M. , Hux Janet E. , Tu Jun‐bi
Published: March 2003

OBJECTIVES:

The extensive use of benzodiazepines has been a concern of healthcare providers and policy makers in Canada and around the world. The purpose of this study was to examine temporal trends in benzodiazepine prescriptions dispensed in older people from 1993–1998.

DESIGN:

Retrospective population‐based cross‐sectional study using administrative databases.

SETTING:

Ontario, Canada.

PARTICIPANTS:

The over 1 million residents of Ontario age 65 and older covered by the provincial universal drug benefit program.

MEASUREMENTS:

The main outcome measures were the prevalence, overall and with respect to age and gender, of benzodiazepine prescriptions dispensed and the ratio of the number of people to whom short‐ versus long‐acting benzodiazepine prescriptions were dispensed in each study year. The annual rates of switching to other psychotropic agents were examined for those patients that discontinued filling benzodiazepine prescriptions.

RESULTS:

The annual prevalence of benzodiazepine prescriptions dispensed decreased consistently over time (25.1% in 1993 to 22.5% in 1998; P < .001). Benzodiazepine dispensing prevalence increased with increasing age (approximately 20% of those age 65 to 69 to approximately 30% of those age ≥85; P < .001) and more females than males received the medication (relative risk = 1.50, 95% confidence interval = 1.49–1.51). The ratio of short‐ to long‐acting benzodiazepine prescriptions filled increased over time (3.6 in 1993 to 5.8 in 1998; P < .001), in line with guideline recommendations. Rates of switching to antidepressants increased over time (8.5% in 1993 to 10.2% in 1998; P < .001), whereas switching to barbiturates was consistently low (0.12%; P = .403).

CONCLUSION:

The prevalence of benzodiazepine therapy for older people in Ontario has steadily declined between 1993 and 1998. There is a trend of dispensing relatively more short‐acting than long‐acting benzodiazepines and of replacing benzodiazepines with antidepressants in older people without a remarkable increase in barbiturate consumption. These findings suggest that, without undue regulation, physicians are making progress in the prescribing of benzodiazepine therapy on the basis of current knowledge available. J Am Geriatr Soc 49:1341–1345, 2001.
Diabetes Mellitus in a Subgroup of Older Mexicans: Prevalence, Association with Cardiovascular Risk Factors, Functional and Cognitive Impairment, and Mortality
Authors: Rodríguez‐Saldaña Joel , Morley John E. , Reynoso Marco T. , Medina Carlos A. , Salazar Paulina , Cruz Eduardo , Torres A. L. Nayeli
Published: March 2003

OBJECTIVES: To examine the prevalence and effects of diabetes mellitus in a subgroup of older Mexicans to allow comparisons to older persons of Mexican origin living in the United States.

DESIGN: Longitudinal study.

SETTING: High‐rise retirement housing in Mexico City.

PARTICIPANTS: Seven hundred eighty‐five public servants and their family members aged 65 and older.

MEASUREMENTS: Geriatric survey of function; mental status and depression; a physical examination; and blood samples for glucose and cholesterol.

RESULTS: The prevalence of diabetes mellitus in this population was 15.1%, substantially lower than the prevalence reported in people of Mexican origin living in the United States. Nondiabetics were more obese than diabetics. Diabetes mellitus was more common in men than women. The mortality rate was greater in diabetics than nondiabetics (relative risk = 1.73, P < .05). Diabetics had more coronary artery disease and were more likely to die from myocardial infarction and neoplasms than nondiabetics. Diabetics were more likely to be functionally impaired (P < .0001) but no more likely to fall or to have fractures. Diabetics did not differ from nondiabetics in cognitive impairment or level of dysphoria.

CONCLUSION: These studies highlight some important similarities and differences in comparing a middle class subgroup of older diabetics in Mexico City with diabetics of Mexican origin living in the United States.
Obesity Is Associated with Functional Decline in Community‐Dwelling Rural Older Persons
Authors: Jensen Gordon L. , Friedmann Janet M.
Published: March 2003

OBJECTIVES: This investigation sought to examine potential gender differences in the relationship between body mass index (BMI) and functional decline.

DESIGN: Cohort study.

SETTING: Rural Pennsylvania.

PARTICIPANTS: Medicare managed‐risk program participants (aged ≥65) in the Geisinger Health Plan. Mean age at study baseline was 71. Final analyzable sample was 2,634 participants.

MEASUREMENTS: Self‐reported weight, weight change, living and eating habits, alcohol and medication use, depression, dentition, and functional status were obtained upon enrollment and again between 3 and 4 years later. Measured height and weight were also recorded at enrollment. Functional decline was defined as any increase in reported limitations in activities of daily living or instrumental activities of daily living over the study period. Logistic regression was used to evaluate the relationship between BMI, as defined by current National Institutes of Health categories, and risk of functional decline while controlling for age, depression, and polypharmacy. The referent category was BMI 18.5 to 24.9.

RESULTS: Women had a higher prevalence of reported functional decline than men at the upper range of BMI categories (31.4% vs 14.3% for BMI ≥40). Women (odds ratio (OR) = 2.61, 95% confidence interval (CI) = 1.39–4.95) and men (OR = 3.32, 95% CI = 1.29–8.46) exhibited increased risk for any functional decline at BMI of 35 or greater. Weight loss of 10 pounds and weight gain of 20 pounds were also risk factors for any functional decline.

CONCLUSIONS: Obesity was a risk factor for functional decline in older persons of either gender. Change in body weight did not benefit function for many older persons.
Inappropriate Prescribing Before and After Nursing Home Admission
Authors: Dhalla Irfan A. , Anderson Geoffrey M. , Mamdani Muhammad M. , Bronskill Susan E. , Sykora Kathy , Rochon Paula A.
Published: March 2003

OBJECTIVES: To compare the prevalence of inappropriate prescribing before and after nursing home admission and to determine which patient and physician characteristics are associated with inappropriate prescribing in the nursing home setting.

DESIGN: A pre/post retrospective, cohort study.

SETTING: All licensed nursing homes in Ontario, Canada.

PARTICIPANTS: Nineteen thousand nine hundred eleven individuals aged 66 and older, newly admitted to nursing homes in Ontario between April 1, 1997, and March 31, 1999.

MEASUREMENTS: For each patient in the cohort, a subset of the Beers criteria was used to characterize and compare the prevalence of inappropriate prescribing (as indicated by the prescription of one of 49 inappropriate drugs) before and after nursing home admission. A logistic regression model was used to study the association between inappropriate prescribing and patient and physician characteristics.

RESULTS: The proportion of patients receiving a prescription for at least one inappropriate drug decreased from 25.4% before nursing home admission to 20.8% afterward (P < .001). Most patients who had been prescribed an inappropriate agent before nursing home entry had that agent discontinued after admission. The most commonly prescribed inappropriate drugs after nursing home admission were strongly anticholinergic antidepressants (6.4%) and long‐half‐life benzodiazepines (5.9%). Patients younger than 85 were more likely to receive inappropriate drug therapy (odds ratio (OR) = 1.25, 95% confidence interval (CI) = 1.15–1.35) than those aged 85 and older. Other significant predictors were having more than one prescriber (OR = 1.40, 95% CI = 1.29–1.51), having a physician aged 50 or older (OR = 1.14, 95% CI = 1.05–1.23), having a male physician (OR = 1.20, 95% CI = 1.05–1.37), having a nonspecialist physician (OR = 1.23, 95% CI = 1.01–1.49), having a nonurban physician (OR = 1.13, 95% CI = 1.03–1.24), and having a physician practicing outside the greater Ontario metropolitan area (OR = 1.31, 95% CI = 1.19–1.51).

CONCLUSIONS: Although a substantial number of nursing home residents receive inappropriate drug therapy, the prevalence of inappropriate prescriptions in our cohort declined after nursing home admission despite an overall increase in drug use. Patient and physician characteristics were associated with inappropriate prescribing. Targeted interventions such as regionally based education programs or drug use restrictions may reduce the prevalence of inappropriate prescribing.
Inappropriate Medication Prescribing in Residential Care/Assisted Living Facilities
Authors: Sloane Philip D. , Zimmerman Sheryl , Brown Lori C. , Ives Timothy J. , Walsh Joan F.
Published: March 2003

OBJECTIVES: To identify the extent to which inappropriately prescribed medications (IPMs) are administered to older patients in residential care/assisted living (RC/AL) facilities and to describe facility and resident factors associated with receipt of one or more IPMs.

DESIGN: Cross‐sectional study of a stratified, representative sample of 193 facilities in four states.

SETTING: We identified representative geographic regions within Florida, New Jersey, North Carolina, and Maryland and drew from within them a stratified random sample of 193 RC/AL facilities. Three subtypes of facilities were included in the sample: small homes (<16 beds), larger “new‐model” homes, and larger “traditional” homes.

PARTICIPANTS: Within each larger home, a random sample of residents aged 65 and older was approached for consent; in smaller homes all residents were approached. The overall enrollment rate was 92%; 2,078 residents were enrolled.

MEASUREMENTS: Questionnaires and on‐site observations were used to gather data on facility administration and staffing and resident characteristics. All prescription and nonprescription medications taken at least 4 of the 7 days before data collection were taken from medication administration records and coded for analysis. IPM designation was based on modification of a list developed by Beers et al. and currently used by nursing home surveyors.

RESULTS: The majority of RC/AL patients were taking five or more medications; 16.0% of these patients were receiving IPMs. The most common IPMs were oxybutynin, propoxyphene, diphenhydramine, ticlopidine, doxepin, and dipyridamole. In multivariate analyses, using generalized estimating equations, IPM use was associated with the number of medications received, smaller facility bed size, moderate licensed practical nurse turnover, absence of dementia, low monthly fees, and absence of weekly physician visits.

CONCLUSIONS: IPMs remain a problem in long‐term care, but rates in these RC/AL settings compare favorably with those reported for other frail older populations, suggesting that use of medications with severe adverse effects may be waning. Regular physician facility visits may improve prescribing, as will attention to high‐risk groups such as individuals on multiple medications.
Prevalence of and Association Between Silent Myocardial Ischemia and New Coronary Events in Older Men and Women with and without Cardiovascular Disease
Authors: Aronow Wilbert S. , Ahn Chul , Mercando Anthony D. , Epstein Stanley , Kronzon Itzhak
Published: March 2003

OBJECTIVES: To investigate the prevalence of silent ischemia (SI) in older men and women detected by 24‐hour ambulatory electrocardiograms (AECGs) and the association between SI and new coronary events.

DESIGN: In a prospective study, the prevalence of SI detected by 24‐hour AECGs and the incidence of new coronary events in 915 older men and 1,874 older women with coronary artery disease (CAD); with hypertension, valvular disease, or cardiomyopathy without CAD; and with no cardiovascular disease were investigated.

SETTING: Large long‐term healthcare facility.

PARTICIPANTS: Nine hundred fifteen men, mean age 80, and 1,874 women, mean age 81.

MEASUREMENTS: The prevalence of SI and the incidence of new coronary events in older men and women.

RESULTS: SI was present in 34% of men and 33% of women with CAD; 15% of men and 14% of women with hypertension, valvular disease, or cardiomyopathy without CAD; and 6% of men and 5% of women with no cardiovascular disease. At 45‐month follow‐up in men and 47‐month follow‐up in women, SI significantly increased the incidence of new coronary events by 2.0 times in men and women with CAD (P < .001); by 1.8 times in men and 1.7 times in women with hypertension, valvular disease, or cardiomyopathy without CAD (P < .001); and by 6.3 times in men (P = .018) and 4.4 times in women (P = .008) with no cardiovascular disease.

CONCLUSIONS: SI increases the incidence of new coronary events in older men and women with CAD, with hypertension, valvular disease, or cardiomyopathy without CAD, and with no cardiovascular disease.
Improving Medication Use in Newly Admitted Home Healthcare Patients: A Randomized Controlled Trial
Authors: Meredith Sarah , Feldman Penny , Frey Dennee , Giammarco Lisa , Hall Kathi , Arnold Kristina , Brown Nancy J. , Ray Wayne A.
Published: March 2003

OBJECTIVES: To test the efficacy of a medication use improvement program developed specifically for home health agencies. The program addressed four medication problems identified by an expert panel: unnecessary therapeutic duplication, cardiovascular medication problems, use of psychotropic drugs in patients with possible adverse psychomotor or adrenergic effects, and use of nonsteroidal antiinflammatory drugs (NSAIDs) in patients at high risk of peptic ulcer complications. It used a structured collaboration between a specially trained clinical pharmacist and the patients' home‐care nurses to improve medication use.

DESIGN: Parallel‐group, randomized controlled trial.

SETTING: Two of the largest home health agencies in the United States.

PARTICIPANTS: Study subjects were consenting Medicare patients aged 65 and older admitted to participating agency offices from October 1996 through September 1998, with a projected home healthcare duration of at least 4 weeks and at least one study medication problem.

INTERVENTION: Qualifying patients were randomized to usual care or usual care with the medication improvement program.

MEASUREMENTS: Medication use was measured during an in‐home interview, with container inspection at baseline and at follow‐up (between 6 and 12 weeks) by interviewers unaware of treatment assignment. The trial endpoint was the proportion of patients with medication use improvement according to predefined criteria at follow‐up.

RESULTS: There were 259 randomized patients with completed follow‐up interviews: 130 in the intervention group and 129 with usual care. Medication use improved for 50% of intervention patients and 38% of control patients, an attributable improvement of 12 patients per 100 (95% confidence interval (CI) = 0.0–24.0, P = .051). The intervention effect was greatest for therapeutic duplication, with improvement for 71% of intervention and 24% of control patients, an attributable improvement of 47 patients per 100 (95% CI = 20–74, P = .003). Use of cardiovascular medications also improved more frequently in intervention patients: 55% vs 18%, attributable improvement 37 patients per 100 (95% CI = 9–66, P = .017). There were no significant improvements for the psychotropic medication or NSAID problems. There was no evidence of adverse intervention effects: new medication problems, more agency nurse visits, or increased duration of home health care.

CONCLUSIONS: A program congruent with existing personnel and practices of home health agencies improved medication use in a vulnerable population and was particularly effective in reducing therapeutic duplication.
Leptin Levels are Appropriate for Body Mass Index in Older Men Who Experience Involuntary Weight Loss
Authors: Yukawa Michi , McCormick Wayne C. , Rajan Suparna , Matsumoto Alvin M. , Wallace Jeffery I. , Pearlman Robert A. , Weigle David S.
Published: March 2003

OBJECTIVES: To determine the relationship between leptin and unintentional weight loss in older adults.

DESIGN: Prospective cohort study over 2 years.

SETTING: University‐affiliated Veterans Affairs Medical Center.

PARTICIPANTS: The subjects were 105 community‐dwelling male veterans aged 65 and older who had participated in a prospective cohort study on nutrition and health conducted at the Veterans Affairs Puget Sound Health Care System from 1986 to 1989.

MEASUREMENTS: Anthropometric data and fasting blood specimens were collected at baseline and annually for the subsequent 2 years. Stored blood specimens were analyzed for leptin, insulin, glucose, C‐reactive protein, sex hormone binding globulin, and testosterone levels.

RESULTS: Over 2 years, 75 men were weight stable (weight loss <4% of baseline) and 30 men had unintentional weight loss (weight loss>4% of baseline). The baseline body mass index (BMI) and leptin levels for the two groups were not statistically different. Positive correlations existed between leptin level and BMI at each time point for weight‐stable and weight‐loss subjects. Furthermore, a significant relationship existed between changes in leptin and changes in BMI over 1 year in multiple regression analysis (r = .436, P < .001 after the first year; and r = .630, P = .027 after the second year).

CONCLUSIONS: Like in younger adults, plasma leptin levels remained proportional to BMI, and changes in BMI were accurately reflected by changes in leptin levels in older individuals. Fasting leptin levels did not predict involuntary weight loss over 2 years of follow‐up.
Multifocal Glasses Impair Edge‐Contrast Sensitivity and Depth Perception and Increase the Risk of Falls in Older People
Authors: Lord Stephen R. , Dayhew Julia , Sc B App , Howland Amelia
Published: March 2003

OBJECTIVES: To determine the extent to which multifocal glasses impair contrast sensitivity and depth perception at critical distances required for detecting hazards in the environment and whether multifocal glasses use increases the risk of falls in older people.

DESIGN: One‐year prospective cohort study.

SETTING: Falls Laboratory, Prince of Wales Medical Research Institute.

PARTICIPANTS: One hundred fifty‐six community‐dwelling people aged 63–90.

MEASUREMENTS: Contrast sensitivity, depth perception, accidental falls.

RESULTS: Eighty‐seven subjects (55.8%) were regular wearers of multifocal (bifocal, trifocal, or progressive lens) glasses. These subjects performed significantly worse in the distant depth perception and distant edge‐contrast sensitivity tests in conditions that forced them to view test stimuli through the lower segments of their glasses. Multifocal glasses wearers were more than twice as likely to fall in the follow‐up period than nonmultifocal glasses wearers (odds ratio (OR) = 2.29, 95% confidence interval (CI) = 1.06–4.92), when adjusting for age, poor vision, reduced lower limb sensation and strength, slow reaction time, and increased postural sway. Multifocal glasses wearers were also more likely to fall because of a trip (OR = 2.79, 95% CI = 1.08–7.22), when outside their homes (OR = 2.55, 95% CI = 1.14–5.70), and when walking up or down stairs (P < .01). The population attributable risks of regular multifocal glasses use were 35.2% for any falls, 40.9% for falls due to a trip, and 40.9% for falls outside the home.

CONCLUSIONS: The study findings indicate that multifocal glasses impair depth perception and edge‐contrast sensitivity at critical distances for detecting obstacles in the environment. Older people may benefit from wearing nonmultifocal glasses when negotiating stairs and in unfamiliar settings outside the home.