bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Fluid Dynamics Analysis of a Maglev Centrifugal Left Ventricular Assist Device
Authors: Burgreen Greg W. , Loree Howard M. , Bourque Kevin , Dague Charles , Poirier Victor L. , Farrar David , Hampton Edward , Wu Z. Jon , Gempp Thomas M. , Schöb Reto
Published: September 2004

Abstract: The fluid dynamics of the Thoratec HeartMate III (Thoratec Corp., Pleasanton, CA, U.S.A.) left ventricular assist device are analyzed over a range of physiological operating conditions. The HeartMate III is a centrifugal flow pump with a magnetically suspended rotor. The complete pump was analyzed using computational fluid dynamics (CFD) analysis and experimental particle imaging flow visualization (PIFV). A comparison of CFD predictions to experimental imaging shows good agreement. Both CFD and experimental PIFV confirmed well‐behaved flow fields in the main components of the HeartMate III pump: inlet, volute, and outlet. The HeartMate III is shown to exhibit clean flow features and good surface washing across its entire operating range.
Resonant Frequency Control for Artificial Heart Using Online Parameter Identification
Authors: Kosaka Ryo , Sankai Yoshiyuki , Jikuya Tomoaki , Yamane Takashi , Tsutsui Tatsuo
Published: September 2004

Abstract: To develop effective medical care and therapeutic control using an artificial heart, a new control method has been developed. This new method can control the artificial heart effectively and can adapt to internal physiological behavior using measured physiological data; aortic pressure, aortic flow, and pump flow. This method consists of first, a second‐order physiological model, which represents the internal physiological behavior by a mathematical equation; and second, an estimation method, which can identify the physiological parameters; aortic inertia, aortic resistance, aortic compliance, and peripheral resistance by a parameter identification method. It can then calculate the resonant frequency as the control signal for the artificial heart from the identified physiological model. To confirm the effectiveness, the proposed method was evaluated in a computer simulation study. This evaluation showed that the new method could estimate the physiological parameters and the resonant frequency within a 10% error. The impedance of the systemic circulation could also be reduced by this method.
Concept for a New Hydrodynamic Blood Bearing for Miniature Blood Pumps
Authors: Kink Thomas , Reul Helmut
Published: September 2004

Abstract: The most crucial element of a long‐term implantable rotary blood pump is the rotor bearing. Because of heat generation and power loss resulting from friction, seals within the devices have to be avoided. Actively controlled magnetic bearings, although maintenance‐free, increase the degree of complexity. Hydrodynamic bearings for magnetically coupled rotors may offer an alternative solution to this problem. Additionally, for miniature pumps, the load capacity of hydrodynamic bearings scales slower than that of, for example, magnetic bearings because of the cube‐square‐law. A special kind of hydrodynamic bearing is a spiral groove bearing (SGB), which features an excellent load capacity. Mock‐loop tests showed that SGBs do not influence the hydraulic performance of the tested pumps. Although, as of now, the power consumption of the SBG is higher than for a mechanical pivot bearing, it is absolutely contact‐free and has an unlimited lifetime. The liftoff of the rotor occurs already at 10% of design speed. Further tests and flow visualization studies on scaled‐up models must demonstrate its overall blood compatibility.
Design, Development, and First In Vivo Results of an Implantable Ventricular Assist Device, MicroVad
Authors: Kerkhoffs Wolfgang , Schumacher Oliver , Meyns Bart , Verbeken Erik , Leunens Veerle , Bollen Hilde , Reul Helmut
Published: September 2004

Abstract: The design concept and first in vitro and in vivo results of a long‐term implantable ventricular assist device system based on a microaxial blood pump are presented. The blood‐immersed parts of the pump consist of a single‐stage impeller and a proximally integrated microelectric motor. Both parts are surrounded by a pump housing currently made of polycarbonate to allow visible access to the blood‐exposed parts. A titanium inflow cage attached to the tip of the housing is directly implanted into the left ventricular apex. The outflow of the pump is connected to the descending aorta by means of an e‐PTFE graft. The overall dimensions of the device are 12 mm in outer diameter and about 50 mm in length. The calculated lifetime of the device is up to 2 years. The system underwent long‐term durability tests, hydraulic performance tests, dynamic stability tests, and in vitro hemolysis and thrombogenicity tests. Furthermore, animal tests have been performed in adult Dorset sheep. In a first series, the pump has been placed extracorporeally; in a second series, the pump was completely implanted. Mean duration of the animal experiments of the second series was 31 days (range 8–110 days, n = 14); no anticoagulation was administered over the whole test period. Blood data revealed no significant changes in blood cell counts, ionogram, or any other value. No end‐organ dysfunction induced by long‐term support could be observed, nor did the pathology reveal any evidence  of  thromboembolic  complications.
Inlet and Outlet Devices for Rotary Blood Pumps
Authors: Song Xinwei , Wood Houston G. , Allaire Paul E. , Antaki James F. , Olsen Don B.
Published: September 2004

Abstract: The purposes of inlet and outlet devices for rotary blood pumps, including inducers and diffusers for axial pumps, inlet and exit volutes for centrifugal pumps, and inlet and outlet cannulas, are to guide the blood into the impeller, where the blood is accelerated, and to convert the high kinetic energy into pressure after the impeller discharge, respectively. The designs of the inlet and outlet devices have an important bearing on the pump performance. Their designs are highly dependent on computational fluid dynamics (CFD) analysis, guided by intuition and experience. For inlet devices, the design objectives are to eliminate separated flow, to minimize recirculation, and to equalize the radial components of velocity. For outlet devices, the design goals are to reduce speed, to minimize energy loss, and to avoid flow separation and whirl. CFD analyses indicate the velocity field and pressure distribution. Geometrical optimization of these components has been implemented in order to improve the flow pattern.
Behavioral Symptoms in Residential Care/Assisted Living Facilities: Prevalence, Risk Factors, and Medication Management
Authors: Gruber‐Baldini Ann L. , Boustani Malaz , Sloane Philip D. , Zimmerman Sheryl
Published: September 2004

Objectives: To examine the prevalence, correlates, and medication management of behavioral symptoms in elderly people living in residential care/assisted living (RC/AL) facilities.

Design: Cross‐sectional study.

Settings: A stratified random sample of 193 RC/AL facilities in four states (Florida, Maryland, New Jersey, North Carolina).

Participants: A total of 2,078 RC/AL residents aged 65 and older.

Measurement: Behavioral symptoms were classified using a modified version of the Cohen‐Mansfield Agitation Inventory. Additional items on resistance to care were also examined.

Results: Approximately one‐third (34%) of RC/AL residents exhibited one or more behavioral symptoms at least once a week. Thirteen percent exhibited aggressive behavioral symptoms, 20% demonstrated physically nonaggressive behavioral symptoms, 22% expressed verbal behavioral symptoms, and 13% resisted taking medications or activities of daily living care. Behavioral symptoms were associated with the presence of depression, psychosis, dementia, cognitive impairment, and functional dependency, and these relationships persisted across subtypes of behavioral symptoms. Overall, behavioral symptoms were more prevalent in smaller facilities. More than 50% of RC/AL residents were taking a psychotropic medication, and two‐thirds had some mental health problem indicator (dementia, depression, psychosis, or other psychiatric illness).

Conclusion: Integrating mental health services within the process of care in RC/AL is needed to manage and accommodate the high prevalence of behavioral symptoms in this evolving long‐term setting.
The Maryland Assisted Living Study: Prevalence, Recognition, and Treatment of Dementia and Other Psychiatric Disorders in the Assisted Living Population of Central Maryland
Authors: Rosenblatt Adam , Samus Quincy M. , Steele Cynthia D. , Baker Alva S. , Harper Michael G. , Brandt Jason , Rabins Peter V. , Lyketsos Constantine G.
Published: September 2004

Objectives: To obtain a direct estimate of the prevalence of dementia and other psychiatric disorders in residents of assisted living (AL) in Central Maryland, and their rates of recognition and treatment.

Design: Comprehensive review of history and cognitive and neuropsychiatric evaluations using widely accepted instruments in a randomized cohort of AL residents, stratified by facility size. An expert multidisciplinary consensus panel determined diagnoses and appropriateness of treatment.

Setting: Twenty‐two (10 large and 12 small) randomly selected AL facilities in the city of Baltimore and seven Maryland counties.

Participants: One hundred ninety‐eight volunteers who were residents of AL, 75% were aged 80 and older, and 78% were female. Potential participants were randomly chosen by room number. There was a 67% participation rate.

Measurements: Overall rate of dementia, noncognitive active psychiatric disorders, and recognition and adequate treatment of dementia and psychiatric disorders, as determined by consensus panel.

Results: Two‐thirds (67.7%) of participants had dementia diagnosable according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (81% small facilities and 63% large). Family or caregivers recognized 78% to 80% of dementias. Seventy‐three percent of dementias were adequately evaluated, and 52% were adequately treated. Of the 26.3% of participants who had an active noncognitive psychiatric disorder, 58% to 61% were recognized and 52% adequately treated.

Conclusion: Dementia and psychiatric disorders are common in AL and have suboptimal rates of recognition and treatment. This may contribute to morbidity and interfere with the ability of residents to age in place.
Chlamydia Pneumoniae Seropositivity and Cardiovascular Risk Factors: The InCHIANTI Study
Authors: Blanc Pierluigi , Corsi Anna Maria , Gabbuti Andrea , Peduzzi Cecilia , Meacci Francesca , Olivieri Fabiola , Lauretani Fulvio , Francesco Mazzotta , Ferrucci Luigi
Published: September 2004

Objectives: To assess the prevalence of Chlamydia pneumoniae (CP) seropositivity and test the hypothesis that CP infection (CPI) is associated with cardiovascular (CV) risk factors and levels of inflammatory biomarkers.

Design: Cross‐sectional survey.

Setting: Representative sample of the residents of Greve in Chianti and Bagno a Ripoli, two small towns located in the Chianti geographic area (Tuscany, Italy).

Participants: A total of 1,304 (age‐range: 20–103, 79% aged≥65) participants of the InCHIANTI study.

Measurements: CP seropositivity was assessed using immunofluorescence. Previous CPI was defined as immunoglobulin (Ig) G ≥1/16 and <1/256, and recent CPI was defined as IgG ≥1/512 or IgM ≥1/16. Inflammatory markers included interleukin (IL)‐6, soluble IL‐6 receptor (sIL‐6r), tumor necrosis factor‐alpha (TNF‐α), IL‐1β, IL‐1 receptor antagonist (IL‐1ra), iron, ferritin, and C‐reactive protein (CRP). CV risk factors included smoking, body mass index (BMI), lipid profile, and hypertension.

Results: The prevalence of CP seropositivity was 75%, increased with age, and was higher in men than in women (P<.01). CPI was not associated with IL‐1β, IL‐1ra, iron, ferritin, CRP, BMI, lipids, and smoking. After adjusting for age and sex, previous or recent CPI was associated with higher TNF‐α (P<.01), IL‐6 (P<.03), sIL‐6R (P<.01), and hypertension (P<.02). In additional age and sex‐adjusted models, the associations between CPI and TNF‐α, IL‐6, sIL‐6r, and hypertension appeared to be mutually independent.

Conclusion: CP seropositivity is highly prevalent in the older population and is a significant, independent correlate of hypertension and circulating levels of TNF‐α, IL‐6, and sIL‐6r.
Longitudinal Study of Determinants of Dependence in an Elderly Population
Authors: Paterson Donald H. , Govindasamy Devin , Vidmar Marjan , Cunningham David A. , Koval John J.
Published: September 2004

Objectives: To describe those factors, from the host of initial measures in ambulatory, independent older men and women, that were determinants of becoming dependent over an 8‐year follow‐up.

Design: Initial measures in a cohort of independent older adults were used in logistic regression to describe the determinants of becoming dependent at the 8‐year follow‐up.

Setting: London, Ontario.

Participants: Three hundred seventy‐three men and women aged 55 to 86.

Measurements: Initial variables included body size, presence of chronic disease, maximal oxygen uptake (VO2max), strength, flexibility, walking pace, and leisure time physical activity.

Results: An 8‐year follow‐up of 297 participants identified 43 as dependent. Logistic regression showed age, presence of disease, and VO2max (cardiorespiratory fitness) at baseline to have significant odds ratios related to the outcome of becoming dependent. Controlling for other factors, a lower VO2max increased the odds of dependence by 14% for each mL/kg·min.

Conclusion: Lower cardiorespiratory fitness was a significant determinant of becoming dependent in an 8‐year follow‐up of older adults. Initiatives to encourage physical activity in older adults should emphasize exercise, such as brisk walking, to maintain or improve cardiorespiratory fitness.
The Association Between Lipid Levels and the Risks of Incident Myocardial Infarction, Stroke, and Total Mortality: The Cardiovascular Health Study
Authors: Psaty Bruce M. , Anderson Melissa , Kronmal Richard A. , Tracy Russell P. , Orchard Trevor , Fried Linda P. , Lumley Thomas , Robbins John , Burke Greg , Newman Anne B. , Furberg Curt D.
Published: September 2004

Objectives: To assess the association between lipid levels and cardiovascular events in older adults.

Design: A prospective population‐based study.

Setting: Four field centers in U.S. communities.

Participants: A total of 5,201 adults aged 65 and older living in U.S. communities, plus a recruitment of 687 African Americans 3 years later.

Measurements: Fasting lipid measures included low‐density lipoprotein cholesterol (LDL‐C), high‐density lipoprotein cholesterol (HDL‐C), total cholesterol, and triglycerides.

Results: At baseline, 1,954 men and 2,931 women were at risk for an incident myocardial infarction (MI) or stroke. During an average 7.5‐year follow‐up, 436 subjects had a coronary event, 332 had an ischemic stroke, 104 a hemorrhagic stroke, and 1,096 died. After adjustment, lipid measures were not major predictors of the outcomes of MI, ischemic stroke, hemorrhagic stroke, and total mortality. For total cholesterol and LDL‐C, the associations with MI and ischemic stroke were only marginally significant. HDL‐C was inversely associated with MI risk (hazard ratio=0.85 per standard deviation of 15.7 mg/dL, 95% confidence interval=0.76–0.96). For the outcome of ischemic stroke, high levels of HDL‐C were associated with a decreased risk in men but not women. Lipid measures were generally only weakly associated with the risks of hemorrhagic stroke or total mortality.

Conclusion: In this population‐based study of older adults, most lipid measures were weakly associated with cardiovascular events. The association between low HDL‐C and increased MI risk was nonetheless strong and consistent.
Risk of Congestive Heart Failure in an Elderly Population Treated with Peripheral Alpha‐1 Antagonists
Authors: Bryson Chris L. , Smith Nicholas L. , Kuller Lewis H. , Chaves Paulo H. M. , Manolio Teri A. , Lewis William , Boyko Edward J. , Furberg Curt D. , Psaty Bruce M.
Published: September 2004

Objectives: To compare the risk of congestive heart failure (CHF) in elderly individuals treated with any peripheral alpha‐1 antagonist for hypertension with any thiazide, test whether the risk persists in subjects without cardiovascular disease (CVD) at baseline, and examine CHF risk in normotensive men with prostatism treated with alpha antagonists.

Design: Prospective cohort study.

Setting: Four U.S. sites: Washington County, Maryland; Allegheny County, Pennsylvania; Sacramento County, California; and Forsyth County, North Carolina.

Participants: A total of 5,888 community‐dwelling subjects aged 65 and older.

Measurements: Adjudicated incident CHF.

Results: The 3,105 participants with treated hypertension were at risk for CHF; 22% of men and 8% of women took alpha antagonists during follow‐up. The age‐adjusted risk of CHF in those receiving monotherapy treated with alpha antagonists was 1.90 (95% confidence interval=1.03–3.50) compared with thiazides. In subjects without CVD at baseline receiving monotherapy, women taking an alpha antagonist had a 3.6 times greater age‐adjusted risk of CHF, whereas men had no difference in risk. Adjustment for systolic blood pressure attenuated statistical differences in risk. There were 930 men without hypertension at risk for CHF; 5% used alpha antagonists during follow‐up, with no observed increase in CHF risk.

Conclusion: Subjects receiving alpha antagonist monotherapy for hypertension had a two to three times greater risk of incident CHF, also seen in lower‐risk subjects, but differences in blood pressure control partly explained this.
A Matched‐Cohort Study of Health Services Utilization and Financial Outcomes for a Heart Failure Disease‐Management Program in Elderly Patients
Authors: Berg Gregory D. , Wadhwa Sandeep , Johnson Alan E.
Published: September 2004

Objectives: To investigate the utilization and financial outcomes of a telephonic nursing disease‐management program for elderly patients with heart failure.

Design: A 1‐year concurrent matched‐cohort study employing propensity score matching.

Setting: Medicare+Choice recipients residing in Ohio, Kentucky, and Indiana.

Participants: A total of 533 program participants aged 65 and older matched to nonparticipants.

Intervention: Disease‐management heart failure program employing a structured, evidence‐based, telephonic nursing intervention designed to provide patient education, counseling, and monitoring services.

Measurements: Medical service utilization, including hospitalizations, emergency department visits, medical doctor visits, skilled nursing facility (SNF) days, selected clinical indicators, and financial effect.

Results: The intervention group had considerably and significantly lower rates of acute service utilization than the control group, including 23% fewer hospitalizations, 26% fewer inpatient bed days, 22% fewer emergency department visits, 44% fewer heart failure hospitalizations, 70% fewer 30‐day readmissions, and 45% fewer SNF bed days. Claims costs were $1,792 per person lower in the intervention group than in the control group (inclusive of intervention costs), and the return on investment was calculated to be 2.31.

Conclusion:

The study demonstrates that a commercially delivered heart failure disease‐management program significantly reduced hospitalizations, emergency department visits, and SNF days. The intervention group had 17% lower costs than the control group; when intervention costs were included, the intervention group had 10% lower costs.
Hyperkyphotic Posture Predicts Mortality in Older Community‐Dwelling Men and Women: A Prospective Study
Authors: Kado Deborah M. , Huang Mei‐Hua , Karlamangla Arun S. , Barrett‐Connor Elizabeth , Greendale Gail A.
Published: September 2004

Objectives: To determine the association between hyperkyphotic posture and rate of mortality and cause‐specific mortality in older persons.

Design: Prospective cohort study.

Setting: Rancho Bernardo, California.

Participants: Subjects were 1,353 participants from the Rancho Bernardo Study who had measurements of kyphotic posture made at an osteoporosis visit between 1988 and 1991.

Measures: Kyphotic posture was measured as the number of 1.7‐cm blocks that needed to be placed under the participant's head to achieve a neutral head position when lying supine on a radiology table. Demographic and clinical characteristics and health behaviors were assessed at a clinic visit using standard questionnaires. Participants were followed for an average of 4.2 years, with mortality and cause of death confirmed using review of death certificates.

Results: Hyperkyphotic posture, defined as requiring one or more blocks under the occiput to achieve a neutral head position while lying supine, was more common in men than women (44% in men, 22% of women, P<.0001). In age‐ and sex‐adjusted analyses, persons with hyperkyphotic posture had a 1.44 greater rate of mortality (95% confidence interval (CI)=1.12–1.86, P=.005). In multiply adjusted models, the increased rate of death associated with hyperkyphotic posture remained significant (relative hazard=1.40, 95% CI=1.08–1.81, P=.012). In cause‐specific mortality analyses, hyperkyphotic posture was specifically associated with an increased rate of death due to atherosclerosis.

Conclusion: Older men and women with hyperkyphotic posture have higher mortality rates.
Geriatric Patients Improve as Much as Younger Patients from Hospitalization on General Psychiatric Units
Authors: Snowden Mark B. , Walaszek Art , Russo Joan E. , Comtois Kate A. , Srebnik Debra S. , Ries Richard K. , Roy‐Byrne Peter P.
Published: September 2004

Objectives: To determine whether geriatric patients aged 65 and older on general adult psychiatric units improve as much as younger patients, over what duration their improvement occurs, and their risk of readmission.

Design: Cohort study.

Setting: Inpatient psychiatric unit of an urban, university‐affiliated, county hospital from January 1993 through August 1999.

Participants: A total of 5,929 inpatients.

Measurements: Standardized, routine assessments by attending psychiatrists included the Psychiatric Symptom Assessment Scale (PSAS) on admission and discharge. Discharge scores, length of stay (LOS), and risk of readmission within 1 year were modeled for the groups using multiple regression analyses.

Results: Geriatric patients constituted 5% (n=299) of the 5,929 admissions. In multivariate analysis, geriatric status was not associated with discharge PSAS scores. Median LOS was longer for geriatric patients (16 days) than younger patients (10 days, P<.001), especially in older women (14 days) and geriatric patients with mild medical illness severity (13 days vs 11 days in those with moderate‐to‐severe medical illness). Geriatric patients were as likely to be readmitted within 1 year of discharge as younger patients.

Conclusion: Geriatric patients on general inpatient psychiatry units improved as much as younger patients. Their longer LOS was associated with milder medical illness severity. There may be a role for more specialized care of elderly women or geriatric patients with mild to moderate medical illness to improve the efficiency of their care.
Patterns of Presentation, Diagnosis, and Treatment in Older Patients with Colon Cancer and Comorbid Dementia
Authors: Gupta Supriya K. , Lamont Elizabeth B.
Published: September 2004

Objectives: To estimate patterns of colon cancer presentation, diagnosis, and treatment according to history of dementia using National Cancer Institute (NCI) Surveillance, Epidemiology, and End‐Result (SEER) Medicare data.

Design: Population‐level cohort study.

Setting: NCI's SEER‐Medicare database.

Participants: A total of 17,507 individuals aged 67 and older with invasive colon cancer (Stage I‐IV) were identified from the 1993–1996 SEER file. Medicare files were evaluated to determine which patients had an antecedent diagnosis of dementia.

Measurements: Parameters relating to the cohort's patterns of presentation and care were estimated using logistic regressions.

Results: The prevalence of dementia in the cohort of newly diagnosed colon cancer patients was 6.8% (1,184/17,507). Adjusting for possible confounders, dementia patients were twice as likely to have colon cancer reported after death (i.e., autopsy or death certificate) (adjusted odds ratio (AOR)=2.31, 95% confidence interval (CI)=1.79–3.00). Of those diagnosed before death (n=17,049), dementia patients were twice as likely to be diagnosed noninvasively than with tissue evaluation (i.e., positive histology) (AOR=2.02 95% CI=1.63–2.51). Of patients with Stage I ‐III disease (n=12,728), patients with dementia were half as likely to receive surgical resection (AOR=0.48, 95% CI=0.33–0.70). Furthermore, of those with resected Stage III colon cancer (n=3,386), dementia patients were 78% less likely to receive adjuvant 5‐fluorouracil (AOR=0.22, 95% CI=0.13–0.36).

Conclusion: Although the incidences of dementia and cancer rise with age, little is known about the effect of dementia on cancer presentation and treatment. Elderly colon cancer patients are less likely to receive invasive diagnostic methods or curative‐intent therapies. The utility of anticancer therapies in patients with dementia merits further study.
Breast Cancer Screening in Women Aged 80 and Older: Results from a National Survey
Authors: Schonberg Mara A. , McCarthy Ellen P. , Davis Roger B. , Phillips Russell S. , Hamel Mary B.
Published: September 2004

Objectives: To estimate the national rates of mammography screening in women aged 80 and older and examine the relationship between health status and screening within the previous 2 years.

Design: Population‐based survey.

Setting: United States.

Participants: Eight hundred eighty‐two women aged 80 and older who responded to the 2000 National Health Interview Survey, representing an estimated 3.83 million noninstitutionalized women nationally.

Measurements: Screening mammography, disease burden, and functional status were assessed using a questionnaire.

Results: Of the 882 women, 41.5% were aged 85 and older; 19.6% had two or more significant diseases; and 12.1% were dependent in at least one activity of daily living (ADL). More than half (50.8%) had received a screening mammogram within the previous 2 years. Women with two or more significant diseases were less likely to have received screening than those without significant disease, but the difference was not statistically significant (43.9% vs 54.0%, P=.152). Women dependent in at least one ADL were less likely to receive screening mammography than women without functional impairment (37.2% vs 55.9%, P<.001). After adjustment, the likelihood of screening remained lower in women with two or more significant diseases (adjusted odds ratio (AOR)=0.63, 95% confidence interval (CI)=0.40–1.05) and in women with at least one ADL dependency (AOR=0.44, 95% CI=0.22–0.88). Of 294 women likely to have life expectancies of less than 5 years because of poor health, 39.4% received screening mammography.

Conclusion: More than half of women aged 80 and older in the United States receive screening mammograms. Nearly 40% of women very unlikely to benefit because of poor health received screening mammography.
Body Weight Change and Mortality in a Cohort of Elderly Patients Recently Discharged from the Hospital
Authors: Sullivan Dennis H. , Liu Longjian , Roberson Paula K. , Bopp Melinda M. , Rees Jacqueline C.
Published: September 2004

Objectives: To evaluate the prognostic significance of weight change in frail elderly patients.

Design: Prospective study.

Setting: The general medical or surgical wards of a university‐affiliated Department of Veterans Affairs hospital.

Participants: Six hundred sixty randomly selected subjects aged 65 or older.

Measurements: At admission and discharge, each subject completed a standardized diagnostic evaluation, including demographic variables, and basic medical, functional, and nutritional assessments. Weights were recorded from hospital or clinic visits in the year before admission, during the current hospitalization, and after discharge for a median of 5.6 years. Average yearly intraindividual weight change was calculated using least‐squares regression. Associations between intraindividual weight change and mortality were identified using Cox proportional hazards regression.

Results: During the study, 314 subjects (48%) died. A U‐shaped association between weight change and mortality was observed. Those who were relatively weight stable (±1 kg/y) had the lowest mortality (28%). Compared with this group, the adjusted relative risks (ARR) of death for those who lost 1 or more to less than 3 kg/y and 3 or more kg/y were 2.14 (95% confidence interval (CI)=1.52–3.00) and 3.59 (95% CI=2.58–4.99), respectively. The ARR associated with a weight gain of 1 or more to less than 3 kg/y and 3 or more kg/y was 1.38 (95% CI=0.91–2.10) and 3.73 (95% CI=2.34–5.94), respectively. The amount of bidirectional weight fluctuation (estimated using coefficient of variance) was not significantly associated with mortality.

Conclusion: For reasons that are not clear, elderly patients who gain 3 or more kg/y after hospital discharge are at nearly the same risk of mortality as those who lose this amount of weight.
Risk Factors Relating Blood Markers of Inflammation and Nutritional Status to Survival in Cachectic Geriatric Patients in a Randomized Clinical Trial
Authors: Yeh Shing‐shing , Hafner Alice , Chang Chin‐Kuo , Levine Daniel M. , Parker Thomas S. , Schuster Michael W.
Published: September 2004

Objectives: To evaluate the effect of proinflammatory cytokines, their receptors, and nutritional indicators (at baseline and after 12 weeks of megestrol acetate (MA) treatment) upon long‐term survival in geriatric cachectic patients without active acute infections, inflammation, or cancer.

Design: Randomized clinical trial with placebo or MA treatment for 12 weeks and then follow‐up for more than 4 years.

Setting: Veterans Affairs nursing home in Northport, New York.

Participants: Nursing home patients with weight loss of 5% of usual body weight over the previous 3 months or body weight 20% below ideal body weight.

Intervention: Random assignment of placebo or MA oral suspension 800 mg/d to the eligible patients for 12 weeks.

Measurements: White blood cell counts, prealbumin, plasma cytokine levels (or their receptors), including tumor necrosis factor receptor (TNFR), soluble subunits (TNFR‐p55 and TNFR‐p75), interleukin (IL)‐6, soluble IL‐2 receptor, and C‐reactive protein at baseline and 12 weeks after treatment.

Results: There was no difference in survival between the MA and placebo groups. Considering possible confounders, initial IL‐6, initial TNFR‐p75 levels, and final neutrophil percentage were associated with elevated mortality, whereas higher initial prealbumin, initial albumin, final prealbumin, final albumin, and final weight gain were associated with decreased death.

Conclusion: In geriatric weight‐loss patients with cachexia, certain cytokines and nutritional indicators were effective in predicting long‐term mortality, regardless of treatment with MA. Interventions to modify levels of these cytokines or their receptors and improvement in nutritional status by weight gain might be helpful in ameliorating undetected chronic inflammation and thus might prolong the survival of these nursing home residents.
Insulin Resistance and Executive Dysfunction in Older Persons
Authors: Abbatecola Angela M. , Paolisso Giuseppe , Lamponi Marco , Bandinelli Stefania , Lauretani Fulvio , Launer Lenore , Ferrucci Luigi
Published: September 2004

Objectives: To evaluate the association between insulin resistance (IR) and executive dysfunction in a large, population‐based study of older persons without diabetes mellitus (DM) or dementia.

Design: Cross‐sectional study.

Setting: Outpatient clinic in Greve in Chianti and Bagno a Ripoli, Italy.

Participants: A total of 597 subjects aged 65 to 93 without DM or dementia.

Measurements: Anthropometric measurements; plasma fasting levels of glucose, insulin, cholesterol (total cholesterol, high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol), and insulin‐like growth factor‐1 (IGF‐1); homeostasis model assessment (HOMA) to estimate degree of IR; Trail Making Test (TMT) A; TMT‐B; TMT‐B minus TMT‐A (DIFF B–A); and Mini‐Mental State Examination (MMSE).

Results: IR (HOMA) was associated with longer TMT‐B (correlation coefficient (r)=0.11; P=.006) and DIFF B–A times (r=0.10; P=.022). Subjects in the upper tertile of IR were older and had longer TMT‐B and DIFF B–A than participants in the lowest tertile. After adjusting for age, sex, and years of formal education, IR was significantly correlated with TMT‐A, TMT‐B, and DIFF B–A. After adjusting for age, sex, education, body mass index, waist:hip girth ratio, HDL‐C, triglycerides, IGF‐1, hypertension, drug intake, and physical activity, the results did not significantly change. After introducing MMSE score into the model, IR continued to be an independent determinant of TMT‐A (β=11.005; P=.021), TMT‐B (β=28.379; P<.001), and DIFF B–A (β=17.374; P=.011).

Conclusion: IR is independently associated with frontal cortex function evidenced by poor TMT times in older persons without DM or dementia.
The Relationship Between Number of Medications and Weight Loss or Impaired Balance in Older Adults
Authors: Agostini Joseph V. , Han Ling , Tinetti Mary E.
Published: September 2004

Objectives: To examine the relationship between cumulative medication exposure and risk of two common manifestations of adverse drug effects: weight loss and impaired balance.

Design: Cross‐sectional and longitudinal cohort.

Setting: Urban Connecticut community.

Participants: Eight hundred eighty‐five community‐dwelling residents aged 72 and older.

Measurements: Weight loss (≥10 pounds) and balance, a composite of four balance measures.

Results: Participants took a mean±standard deviation of 2.2±1.9 medications (range 0–15). After adjustment for age, depressive symptoms, cognitive impairment, vision and hearing impairments, number of chronic diseases, and number of hospitalizations in the previous year, the adjusted odds ratio (OR) for weight loss was 1.48 (95% confidence interval (CI)=0.85–2.59) for those taking one to two medications, 1.96 (95% CI=1.08–3.54) for three to four medications, and 2.78 (95% CI=1.38–5.60) for five or more medications. For impaired balance, adjusted ORs were 1.44 (95% CI=0.94–2.19), 1.72 (95% CI=1.09–2.71), and 1.80 (95% CI=1.02–3.19), respectively.

Conclusion: A greater number of medications were associated with increased risk of adverse drug outcomes, after extensive adjustment for chronic illness. Clinicians should consider the adverse effects of total drug use and not merely the benefits or risks of individual medications for specific diseases.
The Development of a Rapid Screen for Caregiver Burden
Authors: Hirschman Karen B. , Shea Judy A. , Xie Sharon X. , Karlawish Jason H. T.
Published: September 2004

Objectives: To develop a shortened screen for burden associated with caring for a patient with Alzheimer's disease (AD).

Design: Cross‐sectional.

Setting: The Memory Disorders Clinic of an AD center.

Participants: Two hundred fifty‐one AD patient‐caregiver dyads.

Measurements: Screen for Caregiver Burden (SCB), Center for Epidemiologic Studies Depression scale, Medical Outcomes Short Form, Mini‐Mental State Examination, and patient and caregiver characteristics.

Results: At least 25% of the sample endorsed eight of the 25 items in the SCB subjective burden (SB) scale. Of these eight items with a prevalence of 25% or greater endorsement, seven items had item‐total correlations of 0.55 or greater. The shortened seven‐item SCB SB had an alpha of 0.86, indicating that the shortened scale has good internal consistency (Full SCB SB α=0.88). The seven‐item SCB SB was highly associated with depression and overall mental health measures.

Conclusion: This shortened version of the SCB allows a clinician to rapidly assess the burden associated with caregiving for a person with AD.
The Delirium Index, a Measure of the Severity of Delirium: New Findings on Reliability, Validity, and Responsiveness
Authors: McCusker Jane , Cole Martin G. , Dendukuri Nandini , Belzile Eric
Published: September 2004

Objectives: To assess the reliability, validity, and responsiveness of an instrument for measuring the severity of delirium, the Delirium Index (DI).

Design: Prospective cohort study, with repeated patient assessments at multiple points in the hospital, at 8 weeks after discharge, and at 6 and 12 months after admission.

Setting: The medical services of a primary acute‐care hospital.

Participants: Medical admissions aged 65 and older: 165 with delirium and dementia, 57 with delirium only, 55 with dementia only, and 41 with neither.

Measurements: Severity of delirium symptoms was measured using the DI. Delirium was diagnosed using the Confusion Assessment Method. Other measures included the Mini‐Mental State Examination, Informant Questionnaire on Cognitive Decline in the Elderly, Barthel Index (BI), premorbid instrumental activities of daily living, Charlson Comorbidity Index, Clinical Severity of Illness scale (CSI), and the Acute Physiology Score (APS).

Results: The intraclass correlation coefficient of interrater reliability was 0.98. Two measures of fluctuation were significantly higher in patients with delirium than in those without delirium. At baseline, the DI was correlated with the BI, APS, and CSI in delirious patients with (correlation coefficient (r)=−0.43, 0.17, and 0.36, respectively) or without (r=−0.44, 0.39, 0.22, respectively) dementia. At 8 weeks, in delirious patients with and without dementia, internal responsiveness as measured by effect sizes was −0.60 and −0.74, respectively, and the standardized response mean for both groups was −0.64. Low to good levels of external responsiveness were found.

Conclusion: The DI appears to be a reliable, valid, and responsive measure of the severity of delirium, in patients with delirium, with or without dementia.
Association Between Subject Functional Status, Seat Height, and Movement Strategy in Sit‐to‐Stand Performance
Authors: Mazzà Claudia , Benvenuti Francesco , Bimbi Carlo , Stanhope Steven J.
Published: September 2004

Objectives: To explore the association between an individual's functional status, movement task difficulty, and effectiveness of compensatory movement strategies within a sit‐to‐stand (STS) paradigm.

Design: Cross‐sectional study.

Settings: Rehabilitation unit of the Istituto Nazionale Riposo e Cura Anziani Geriatric Hospital of Florence, Italy.

Participants: A convenience sample (131 subjects) of the outpatient clinic and day‐hospital population.

Measurements: A performance‐based test (repeated chair standing) was used to divide the subjects into five functional groups. Subjects performed a series of single STS tasks across a range of five descending seat heights. They were instructed to stand without using arms or compensatory strategies. If unable, swinging the arms was allowed, and if the inability persisted, subjects could push with their arms during subsequent attempts. The strategy or inability to stand formed the dependent measures.

Results: Subjects within the two highest functional groups could complete the single STS task at all seat heights, with a slight increased use of compensatory strategies at the lowest seat height. The effectiveness of the compensatory strategies decreased rapidly as a function of seat height and functional status. One‐third (35.5%) of the subjects in the middle functional group swung their arms at the lower seat heights. Across the three least functional groups, 11.8%, 30.6%, and 83.3% of the subjects, respectively, were unable to stand at the lowest seat height.

Conclusion: The individual's functional status and difficulty of the task influenced the effectiveness of a compensatory strategy to maintain the ability to stand, supporting the idea that disability depends on the interplay between environmental demands and physical ability.
History, Development, and Future of the Progressively Lowered Stress Threshold: A Conceptual Model for Dementia Care
Authors: Smith Marianne , Gerdner Linda A. , Hall Geri R. , Buckwalter Kathleen C.
Published: September 2004

Behavioral symptoms associated with dementia are a major concern for the person who experiences them and for caregivers who supervise, support, and assist them. The knowledge and skill of formal and informal caregivers affects the quality of care they can provide and their ability to cope with the challenges of caregiving. Nurses are in an excellent position to provide training to empower caregivers with the knowledge and skills necessary to reduce and better manage behaviors. This article reviews advances in geriatric nursing theory, practice, and research based on the Progressively Lowered Stress Threshold (PLST) model that are designed to promote more adaptive and functional behavior in older adults with advancing dementia. For more than 17 years, the model has been used to train caregivers in homes, adult day programs, nursing homes, and acute care hospitals and has served as the theoretical basis for in‐home and institutional studies. Care planning principles and key elements of interventions that flow from the model are set forth, and outcomes from numerous research projects using the PLST model are presented.
Outcome Predictors of Pneumonia in Elderly Patients: Importance of Functional Assessment
Authors: Torres Olga H. , Muñoz Jose , Ruiz Domingo , Ris Josep , Gich Ignasi , Coma Eva , Gurguí Mercè , Vázquez Guillermo
Published: September 2004

Objectives: To evaluate the outcome of elderly patients with community‐acquired pneumonia (CAP) seen at an acute‐care hospital, analyzing the importance of CAP severity, functional status, comorbidity, and frailty.

Design: Prospective observational study.

Setting: Emergency department and geriatric medical day hospital of a university teaching hospital.

Participants: Ninety‐nine patients aged 65 and older seen for CAP over a 6‐month recruitment period.

Measurements: Clinical data were used to calculate Pneumonia Severity Index (PSI), Barthel Index (BI), Charlson Comorbidity Index, and Hospital Admission Risk Profile (HARP). Patients were then assessed 15 days later to determine functional decline and 30 days and 18 months later for mortality and readmission. Multiple logistic regression was used to analyze outcomes.

Results: Functional decline was observed in 23% of the 93 survivors. Within the 30‐day period, case‐fatality rate was 6% and readmission rate 11%; 18‐month rates were 24% and 59%, respectively. Higher BI was a protective factor for 30‐day and 18‐month mortality (odds ratio (OR)=0.96, 95% confidence interval (CI)=0.94–0.98 and OR=0.97, 95% CI=0.95–0.99, respectively; P<.01), and PSI was the only predictor for functional decline (OR=1.03, 95% CI=1.01–1.05; P=.01). Indices did not predict readmission. Analyses were repeated for the 74 inpatients and indicated similar results except for 18‐month mortality, which HARP predicted (OR=1.73; 95% CI=1.16–2.57; P<.01).

Conclusion: Functional status was an independent predictor for short‐ and long‐term mortality in hospitalized patients whereas CAP severity predicted functional decline. Severity indices for CAP should possibly thus be adjusted in the elderly population, taking functional status assessment into account.
Pulsatile Flow in Fusiform Models of Abdominal Aortic Aneurysms: Flow Fields, Velocity Patterns and Flow-Induced Wall Stresses
Authors: Peattie Robert A. , Riehle Tiffany J. , Bluth Edward I.
Published: September 2004

As one important step in the investigation of the mechanical factors that lead to rupture of abdominal aortic aneurysms, flow fields and flow-induced wall stress distributions have been investigated in model aneurysms under pulsatile flow conditions simulating the in vivo aorta at rest. Vortex pattern emergence and evolution were evaluated, and conditions for flow stability were delineated. Systolic flow was found to be forward-directed throughout the bulge in all the models, regardless of size. Vortices appeared in the bulge initially during deceleration from systole, then expanded during the retrograde flow phase. The complexity of the vortex field depended strongly on bulge diameter. In every model, the maximum shear stress occurred at peak systole at the distal bulge end, with the greatest shear stress developing in a model corresponding to a 4.3 cm AAA in vivo. Although the smallest models exhibited stable flow throughout the cycle, flow in the larger models became increasingly unstable as bulge size increased, with strong amplification of instability in the distal half of the bulge. These data suggest that larger aneurysms in vivo may be subject to more frequent and intense turbulence than smaller aneurysms. Concomitantly, increased turbulence may contribute significantly to wall stress magnitude and thereby to risk of rupture.
Nitric Oxide Represses the
Arabidopsis
Floral Transition
Authors: He Yikun , Tang Ru-Hang , Hao Yi , Stevens Robert D. , Cook Charles W. , Ahn Sun M. , Jing Liufang , Yang Zhongguang , Chen Longen , Guo Fangqing , Fiorani Fabio , Jackson Robert B. , Crawford Nigel M. , Pei Zhen-Ming
Published: September 2004

The correct timing of flowering is essential for plants to maximize reproductive success and is controlled by environmental and endogenous signals. We report that nitric oxide (NO) repressed the floral transition in
Arabidopsis thaliana
. Plants treated with NO, as well as a mutant overproducing NO (
nox1
), flowered late, whereas a mutant producing less NO (
nos1
) flowered early. NO suppressed
CONSTANS
and
GIGANTEA
gene expression and enhanced
FLOWERING LOCUS C
expression, which indicated that NO regulates the photoperiod and autonomous pathways. Because NO is induced by environmental stimuli and constitutively produced, it may integrate both external and internal cues into the floral decision.
PHYTOCHROME-INTERACTING FACTOR 1 Is a Critical bHLH Regulator of Chlorophyll Biosynthesis
Authors: Huq Enamul , Al-Sady Bassem , Hudson Matthew , Kim Chanhong , Apel Klaus , Quail Peter H.
Published: September 2004

Photosynthetic organisms must achieve a delicate balance between the light energy absorbed by chlorophyll and their capacity to channel that energy into productive photochemical reactions. Release of excess absorbed energy in the cell can cause lethal photooxidative damage. We identified a basic helix-loop-helix (bHLH) transcription factor, designated PHYTOCHROME-INTERACTING FACTOR 1 (PIF1), that negatively regulates chlorophyll biosynthesis.
pif1
mutant seedlings accumulate excess free protochlorophyllide when grown in the dark, with consequent lethal bleaching upon exposure to light. PIF1 interacts specifically with the photoactivated conformer of phytochromes A and B, suggesting a signaling pathway by which chlorophyll biosynthetic rates are tightly controlled during the critical initial emergence of seedlings from subterranean darkness into sunlight.