A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group

BACKGROUND

Serum creatinine concentration is widely used as an index of renal function, but this concentration is affected by factors other than glomerular filtration rate (GFR).

OBJECTIVE

To develop an equation to predict GFR from serum creatinine concentration and other factors.

DESIGN

Cross-sectional study of GFR, creatinine clearance, serum creatinine concentration, and demographic and clinical characteristics in patients with chronic renal disease.

PATIENTS

1628 patients enrolled in the baseline period of the Modification of Diet in Renal Disease (MDRD) Study, of whom 1070 were randomly selected as the training sample; the remaining 558 patients constituted the validation sample.

METHODS

The prediction equation was developed by stepwise regression applied to the training sample. The equation was then tested and compared with other prediction equations in the validation sample.

RESULTS

To simplify prediction of GFR, the equation included only demographic and serum variables. Independent factors associated with a lower GFR included a higher serum creatinine concentration, older age, female sex, nonblack ethnicity, higher serum urea nitrogen levels, and lower serum albumin levels (P < 0.001 for all factors). The multiple regression model explained 90.3% of the variance in the logarithm of GFR in the validation sample. Measured creatinine clearance overestimated GFR by 19%, and creatinine clearance predicted by the Cockcroft-Gault formula overestimated GFR by 16%. After adjustment for this overestimation, the percentage of variance of the logarithm of GFR predicted by measured creatinine clearance or the Cockcroft-Gault formula was 86.6% and 84.2%, respectively.

CONCLUSION

The equation developed from the MDRD Study provided a more accurate estimate of GFR in our study group than measured creatinine clearance or other commonly used equations.

Circulating urokinase receptor as a cause of focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a cause of proteinuric kidney disease, compromising both native and transplanted kidneys. Treatment is limited because of a complex pathogenesis, including unknown serum factors. Here we report that serum soluble urokinase receptor (suPAR) is elevated in two-thirds of subjects with primary FSGS, but not in people with other glomerular diseases. We further find that a higher concentration of suPAR before transplantation underlies an increased risk for recurrence of FSGS after transplantation. Using three mouse models, we explore the effects of suPAR on kidney function and morphology. We show that circulating suPAR activates podocyte β(3) integrin in both native and grafted kidneys, causing foot process effacement, proteinuria and FSGS-like glomerulopathy. Our findings suggest that the renal disease only develops when suPAR sufficiently activates podocyte β(3) integrin. Thus, the disease can be abrogated by lowering serum suPAR concentrations through plasmapheresis, or by interfering with the suPAR-β(3) integrin interaction through antibodies and small molecules targeting either uPAR or β(3) integrin. Our study identifies serum suPAR as a circulating factor that may cause FSGS.

The exocyst is an effector for Sec4p, targeting secretory vesicles to sites of exocytosis

Polarized secretion requires proper targeting of secretory vesicles to specific sites on the plasma membrane. Here we report that the exocyst complex plays a key role in vesicle targeting. Sec15p, an exocyst component, can associate with secretory vesicles and interact specifically with the rab GTPase, Sec4p, in its GTP-bound form. A chain of protein-protein interactions leads from Sec4p and Sec15p on the vesicle, through various subunits of the exocyst, to Sec3p, which marks the sites of exocytosis on the plasma membrane. Sec4p may control the assembly of the exocyst. The exocyst may therefore function as a rab effector system for targeted secretion.

Informal caregiving and its impact on health: a reappraisal from population-based studies

Considerable research and public discourse on family caregiving portrays it as a stressful and burdensome experience with serious negative health consequences. A landmark study by Schulz and Beach that reported higher mortality rates for strained spouse caregivers has been widely cited as evidence for the physical health risks of caregiving and is often a centerpiece of advocacy for improved caregiver services. However, 5 subsequent population-based studies have found reduced mortality and extended longevity for caregivers as a whole compared with noncaregiving controls. Most caregivers also report benefits from caregiving, and many report little or no caregiving-related strain. Policy reports, media portrayals, and many research reports commonly present an overly dire picture of the health risks associated with caregiving and largely ignore alternative positive findings. As the pool of traditional family caregivers declines in the coming years, a more balanced and updated portrayal of the health effects of caregiving is needed to encourage more persons to take on caregiving roles, and to better target evidence-based services to the subgroup of caregivers who are highly strained or otherwise at risk. Recommendations are discussed for research that will better integrate and clarify both the negative and potential positive health effects of informal caregiving.

Grazoprevir plus elbasvir in treatment-naive and treatment-experienced patients with hepatitis C virus genotype 1 infection and stage 4-5 chronic kidney disease (the C-SURFER study): a combination phase 3 study

BACKGROUND

Chronic hepatitis C virus (HCV) infection in patients with stage 4-5 chronic kidney disease increases the risk of death and renal graft failure, yet patients with hepatitis C and chronic kidney disease have few treatment options. This study assesses an all-oral, ribavirin-free regimen in patients with HCV genotype 1 infection and stage 4-5 chronic kidney disease.

METHODS

In this phase 3 randomised study of safety and observational study of efficacy, patients with HCV genotype 1 infection and chronic kidney disease (stage 4-5 with or without haemodialysis dependence) were randomly assigned to receive grazoprevir (100 mg, NS3/4A protease inhibitor) and elbasvir (50 mg, NS5A inhibitor; immediate treatment group) or placebo (deferred treatment group) once daily for 12 weeks. Randomisation was done centrally with an interactive voice response system. An additional cohort of patients who were not randomised received the same regimen open-label and underwent intensive pharmacokinetic sampling. The primary efficacy outcome was a non-randomised comparison of sustained virological response at 12 weeks (SVR12) after the end of therapy for the combined immediate treatment group and the pharmacokinetic population with a historical control. The primary safety outcome was a randomised comparison between the immediate treatment group and the deferred treatment group. After 4 weeks of follow-up (study week 16), unmasking occurred and patients in the deferred treatment group received grazoprevir and elbasvir. The primary efficacy hypothesis was tested at a two-sided significance level (type I error) of 0·05 using an exact test for a binomial proportion. Safety event rates were compared between immediate treatment and deferred treatment groups using the stratified Miettinen and Nurminen method with baseline dialysis status as the strata. The study is registered at ClinicalTrials.gov, number NCT02092350.

FINDINGS

224 patients were randomly assigned to the immediate treatment group with grazoprevir and elbasvir (n=111) or the deferred treatment group (n=113), and 11 were assigned to the intensive pharmacokinetic population. Overall, 179 (76%) were haemodialysis-dependent, 122 (52%) had HCV genotype 1a infection, 189 (80%) were HCV treatment-naive, 14 (6%) were cirrhotic, and 108 (46%) were African American. Of the 122 patients receiving grazoprevir and elbasvir, six were excluded from the primary efficacy analysis for non-virological reasons (death, lost-to-follow-up [n=2], non-compliance, patient withdrawal, and withdrawal by physician for violent behaviour). No patients in the combined immediate treatment group and intensive pharmacokinetic population and five (4%) in the deferred treatment group discontinued because of an adverse event. Most common adverse events were headache, nausea, and fatigue, occurring at similar frequencies in patients receiving active and placebo drugs. SVR12 in the combined immediate treatment group and intensive pharmacokinetic population was 99% (95% CI 95·3-100·0; 115/116), with one relapse 12 weeks after end of treatment when compared with a historical control of 45%, based on meta-analyses of interferon-based regimens used in clinical trials of patients infected with HCV who are on haemodialysis.

INTERPRETATION

Once-daily grazoprevir and elbasvir for 12 weeks had a low rate of adverse events and was effective in patients infected with HCV genotype 1 and stage 4-5 chronic kidney disease.

FUNDING

Merck Sharp & Dohme Corp.

Sequential therapies for proliferative lupus nephritis

BACKGROUND

Long-term therapy with cyclophosphamide enhances renal survival in patients with proliferative lupus nephritis; however, the beneficial effect of cyclophosphamide must be weighed against its considerable toxic effects.

METHODS

Fifty-nine patients with lupus nephritis (12 in World Health Organization class III, 46 in class IV, and 1 in class Vb) received induction therapy consisting of a maximum of seven monthly boluses of intravenous cyclophosphamide (0.5 to 1.0 g per square meter of body-surface area) plus corticosteroids. Subsequently, the patients were randomly assigned to one of three maintenance therapies: quarterly intravenous injections of cyclophosphamide, oral azathioprine (1 to 3 mg per kilogram of body weight per day), or oral mycophenolate mofetil (500 to 3000 mg per day) for one to three years. The base-line characteristics of the three groups were similar, with the exception that the chronicity index was 1.9 points lower in the cyclophosphamide group than in the mycophenolate mofetil group (P=0.009).

RESULTS

During maintenance therapy, five patients died (four in the cyclophosphamide group and one in the mycophenolate mofetil group), and chronic renal failure developed in five (three in the cyclophosphamide group and one each in the azathioprine and mycophenolate mofetil groups). The 72-month event-free survival rate for the composite end point of death or chronic renal failure was higher in the mycophenolate mofetil and azathioprine groups than in the cyclophosphamide group (P=0.05 and P=0.009, respectively). The rate of relapse-free survival was higher in the mycophenolate mofetil group than in the cyclophosphamide group (P=0.02). The incidence of hospitalization, amenorrhea, infections, nausea, and vomiting was significantly lower in the mycophenolate mofetil and azathioprine groups than in the cyclophosphamide group.

CONCLUSIONS

For patients with proliferative lupus nephritis, short-term therapy with intravenous cyclophosphamide followed by maintenance therapy with mycophenolate mofetil or azathioprine appears to be more efficacious and safer than long-term therapy with intravenous cyclophosphamide.

Assessing mobility in older adults: the UAB Study of Aging Life-Space Assessment

BACKGROUND AND PURPOSE

The University of Alabama at Birmingham (UAB) Study of Aging Life-Space Assessment (LSA) is a relatively new instrument to measure mobility. The purpose of this report is to describe the relationships between LSA and traditional measures of physical function, sociodemographic characteristics, depression, and cognitive status.

SUBJECTS

Subjects were a stratified random sample of 998 Medicare beneficiaries aged > or =65 years. The sample was 50% African American, 50% male, and 50% from rural (versus urban) counties.

METHODS

In-home interviews were conducted. Mobility was measured using the LSA, which documents where and how often subjects travel and any assistance needed during the 4 weeks prior to the assessment. Basic activities of daily living (ADL) and instrumental activities of daily living (IADL), cognitive status, income level, presence of depressive symptoms, and transportation resources were determined. The Short Physical Performance Battery (SPPB) was used to assess physical performance.

RESULTS

Simple bivariate correlations indicated a significant relationship between LSA and all variables except residence (rural versus urban). In a regression model, physical function (ADL, IADL) and physical performance (SPPB) accounted for 45.5% of the variance in LSA scores. An additional 12.7% of the variance was explained by sociodemographic variables, and less than 1% was explained by cognition and depressive symptoms.

DISCUSSION AND CONCLUSION

The LSA can be used to document patients' mobility within their home and community. The LSA scores are associated with a person's physical capacity and other factors that may limit mobility. These scores can be used in combination with other tests and measures to generate clinical hypotheses to explain mobility deficits and to plan appropriate interventions to address these deficits.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Improving caregiver well-being delays nursing home placement of patients with Alzheimer disease

OBJECTIVE

To determine the effectiveness of a counseling and support intervention for spouse caregivers in delaying time to nursing home placement of patients with Alzheimer disease (AD), and identify the mechanisms through which the intervention accomplished this goal.

METHODS

We conducted a randomized controlled trial of an enhanced counseling and support intervention compared to usual care. Participants were a referred volunteer sample of 406 spouse caregivers of community-dwelling patients who had enrolled in the study over a 9.5-year period. The intervention consisted of six sessions of individual and family counseling, support group participation, and continuous availability of ad hoc telephone counseling. Structured questionnaires were administered at baseline and at regular follow-up intervals, every 4 months for the first year and every 6 months thereafter. Cox proportional hazard models were used to test the effects of the intervention on the time to nursing home placement for the patients after controlling for multiple time-invariant and time-dependent predictors of placement.

RESULTS

Patients whose spouses received the intervention experienced a 28.3% reduction in the rate of nursing home placement compared with usual care controls (hazard ratio = 0.717 after covariate adjustment, p = 0.025). The difference in model-predicted median time to placement was 557 days. Improvements in caregivers' satisfaction with social support, response to patient behavior problems, and symptoms of depression collectively accounted for 61.2% of the intervention's beneficial impact on placement.

CONCLUSION

Greater access to effective programs of counseling and support could yield considerable benefits for caregivers, patients with Alzheimer disease, and society.

The Epidemiology of Social Isolation: National Health and Aging Trends Study

OBJECTIVES

Social isolation among older adults is an important but under-recognized risk for poor health outcomes. Methods are needed to identify subgroups of older adults at risk for social isolation.

METHODS

We constructed a typology of social isolation using data from the National Health and Aging Trends Study (NHATS) and estimated the prevalence and correlates of social isolation among community-dwelling older adults. The typology was formed from four domains: living arrangement, core discussion network size, religious attendance, and social participation.

RESULTS

In 2011, 24% of self-responding, community-dwelling older adults (65+ years), approximately 7.7 million people, were characterized as socially isolated, including 1.3 million (4%) who were characterized as severely socially isolated. Multinomial multivariable logistic regression indicated that being unmarried, male, having low education, and low income were all independently associated with social isolation. Black and Hispanic older adults had lower odds of social isolation compared with white older adults, after adjusting for covariates.

DISCUSSION

Social isolation is an important and potentially modifiable risk that affects a significant proportion of the older adult population.

Efficacy and Safety of Subcutaneous Belimumab in Systemic Lupus Erythematosus: A Fifty-Two-Week Randomized, Double-Blind, Placebo-Controlled Study

Objective

To assess the efficacy and safety of subcutaneous (SC) belimumab in patients with systemic lupus erythematosus (SLE).

Methods

Patients with moderate‐to‐severe SLE (score of ≥8 on the Safety of Estrogens in Lupus Erythematosus National Assessment [SELENA] version of the SLE Disease Activity Index [SLEDAI]) were randomized 2:1 to receive weekly SC belimumab 200 mg or placebo by prefilled syringe in addition to standard SLE therapy for 52 weeks. The primary end point was the SLE Responder Index (SRI4) at week 52. Secondary end points were reduction in the corticosteroid dosage and time to severe flare. Safety was assessed according to the adverse events (AEs) reported and the laboratory test results.

Results

Of 839 patients randomized, 836 (556 in the belimumab group and 280 in the placebo group) received treatment. A total of 159 patients withdrew before the end of the study. At entry, mean SELENA–SLEDAI scores were 10.5 in the belimumab group and 10.3 in the placebo group. More patients who received belimumab were SRI4 responders than those who received placebo (61.4% versus 48.4%; odds ratio [OR] 1.68 [95% confidence interval (95% CI) 1.25–2.25]; P = 0.0006). In the belimumab group, both time to and risk of severe flare were improved (median 171.0 days versus 118.0 days; hazard ratio 0.51 [95% CI 0.35–0.74]; P = 0.0004), and more patients were able to reduce their corticosteroid dosage by ≥25% (to ≤7.5 mg/day) during weeks 40–52 (18.2% versus 11.9%; OR 1.65 [95% CI 0.95–2.84]; P = 0.0732), compared with placebo. AE incidence was comparable between treatment groups; serious AEs were reported by 10.8% of patients taking belimumab and 15.7% of those taking placebo. A worsening of IgG hypoglobulinemia by ≥2 grades occurred in 0.9% of patients taking belimumab and 1.4% of those taking placebo.

Conclusion

In patients with moderate‐to‐severe SLE, weekly SC doses of belimumab 200 mg plus standard SLE therapy significantly improved their SRI4 response, decreased severe disease flares as compared with placebo, and had a safety profile similar to placebo plus standard SLE therapy.

Can High-Risk Older Drivers Be Identified Through Performance-Based Measures in a Department of Motor Vehicles Setting?

OBJECTIVES

To evaluate the relationship between performance-based risk factors and subsequent at-fault motor vehicle collision (MVC) involvement in a cohort of older drivers.

DESIGN

Prospective cohort study.

SETTING

Motor Vehicle Administration (MVA) field sites in Maryland.

PARTICIPANTS

Of the 4,173 older drivers invited to participate in the study, 2,114 individuals aged 55 to 96 agreed to do so. These analyses focus on 1,910 individuals recruited through MVA field sites.

MEASUREMENTS

Gross Impairment Screening Battery, which included Rapid Pace Walk, Head/Neck Rotation, Foot Tap, Arm Reach, Cued Recall, Symbol Scan, Visual Closure subtest of the Motor Free Visual Perception Test (MVPT), Delayed Recall, and Trail Making Test with an Abbreviated Part A and standard Part B; Useful Field of View (UFOV) subtest 2; a Mobility Questionnaire; and MVC occurrence.

RESULTS

In drivers aged 55 and older with intact vision (20/70 far visual acuity and 140 degrees visual field), age, sex, history of falls, and poorer cognitive performance, as measured using Trails B, MVPT, and UFOV subtest 2, were predictive of future at-fault MVC involvement. After adjusting for annual mileage, participants aged 78 and older were 2.11 as more likely to be involved in an at-fault MVC, those who made four or more errors on the MVPT were 2.10 times as likely to crash, those who took 147 seconds or longer to complete Trails B were 2.01 times as likely to crash, and those who took 353 ms or longer on subtest 2 of the UFOV were 2.02 times as likely to incur an at-fault MVC. Older adults, men, and individuals with a history of falls were more likely to be involved in subsequent at-fault MVCs.

CONCLUSION

Performance-based cognitive measures are predictive of future at-fault MVCs in older adults. Cognitive performance, in particular, is a salient predictor of subsequent crash involvement in older adults. High-risk older drivers can be identified through brief, performance-based measures administered in a MVA setting.

Underdiagnosis of Dementia: an Observational Study of Patterns in Diagnosis and Awareness in US Older Adults

BACKGROUND

Many older adults living with dementia have not been formally diagnosed. Even when clinicians document the diagnosis, patients and families may be unaware of the diagnosis. Knowledge of how individual characteristics affect detection and awareness of dementia is limited.

OBJECTIVE

To identify characteristics associated with dementia diagnosis and awareness of diagnosis.

DESIGN

Cross-sectional observational study.

PARTICIPANTS

Five hundred eighty-five adults aged ≥ 65 in the National Health and Aging Trends Study who met assessment-based study criteria for probable dementia in 2011 and had 3 years of continuous, fee-for-service Medicare claims prior to 2011.

MAIN MEASURES

Using multivariable logistic regression, we compared participants with undiagnosed versus diagnosed dementia (based on Medicare claims) on demographic, social/behavioral, functional, medical, and healthcare utilization characteristics. Among those diagnosed, we compared characteristics of participants unaware versus aware of the diagnosis (based on self or proxy report).

KEY RESULTS

Among older adults with probable dementia, 58.7% were either undiagnosed (39.5%) or unaware of the diagnosis (19.2%). In adjusted analyses, individuals who were Hispanic (OR 2.48, 95% CI 1.19, 5.14), had less than high school education (OR 0.54 for at least high school education, 95% CI 0.32, 0.91), attended medical visits alone (OR 1.98, 95% CI 1.11, 3.51), or had fewer functional impairments (OR 0.79 for each impairment, 95% CI 0.69, 0.90) were more likely to be undiagnosed. Similarly, among those diagnosed, having less education (OR 0.42), attending medical visits alone (OR 1.97), and fewer functional impairments (OR 0.72) were associated with unawareness of diagnosis (all ps < 0.05).

CONCLUSIONS

The majority of older adults with dementia are either undiagnosed or unaware of the diagnosis, suggesting shortcomings in detection and communication of dementia. Individuals who may benefit from targeted screening include racial/ethnic minorities and persons who have lower educational attainment, any functional impairment, or attend medical visits alone.

Appraisal, coping, and social support as mediators of well-being in black and white family caregivers of patients with Alzheimer's disease

Family caregivers of patients with Alzheimer's disease (AD) commonly have high levels of psychological distress. Black caregivers often report less depression than White caregivers, but the process underlying this difference is poorly understood. With the use of a stress process model, 123 White and 74 Black family caregivers of patients with AD and other progressive dementias were studied. Black caregivers appraised patient problems as less stressful and reported higher self-efficacy in managing caregiving problems and less depression than did White caregivers. White and Black caregivers also differed significantly in coping responses but not in social supports. Structural equation analyses indicated that the correlational structure of the stress process was similar in White and Black caregivers. Caregiving stressors and race did not affect well-being through direct paths, but they were mediated by effects for appraisal, social support and activity, and coping. Possible cultural mechanisms explaining the better adjustment among Black caregivers are discussed.

Treadmill running produces both positive and negative physiological adaptations in Sprague-Dawley rats

Exercise training produces a vast array of physiological adaptations, ranging from changes in metabolism to muscle mitochondrial biogenesis. Researchers studying the physiological effects of exercise often use animal models that employ forced exercise regimens that include aversive motivation, which could activate the stress response. This study examined the effect of forced treadmill running (8 wk) on several physiological systems that are sensitive to training and stress. Forced treadmill running produced both positive and negative physiological adaptations. Indicative of positive training adaptations, exercised male Sprague-Dawley rats had a decrease in body weight gain and an increase in muscle citrate synthase activity compared with sedentary controls. In contrast, treadmill running also resulted in the potentially negative adaptations of adrenal hypertrophy, thymic involution, decreased serum corticosteroid binding globulin, elevated lymphocyte nitrite concentrations, suppressed lymphocyte proliferation, and suppressed antigen-specific IgM. Such alterations in neuroendocrine tissues and immune responses are commonly associated with chronic stress. Thus treadmill running produces both positive training adaptations and potentially negative adaptations that are indicative of chronic stress. Researchers employing forced activity need to be aware that this type of exercise procedure also produces physiological adaptations indicative of chronic stress and that these changes could potentially impact other measures of interest.

Sustained benefit of supportive intervention for depressive symptoms in caregivers of patients with Alzheimer's disease

OBJECTIVE

The long-term effect of counseling and support on symptoms of depression was examined in spouse-caregivers of patients with Alzheimer's disease.

METHOD

The participants were 406 spouse-caregivers of Alzheimer's disease patients who lived at home at baseline. The caregivers were randomly assigned to either a group receiving enhanced counseling and support treatment or a group receiving usual care (control group). Caregivers in the enhanced treatment group were provided with six sessions of individual and family counseling, agreed to join support groups 4 months after enrollment, and received ongoing ad hoc counseling. The Geriatric Depression Scale was administered at baseline and at regular follow-up intervals for as long as the caregiver participated in the study.

RESULTS

After baseline differences were controlled for, caregivers in the enhanced treatment group had significantly fewer depressive symptoms after the intervention than did the control subjects. These effects were sustained for 3.1 years after baseline, similar across gender and patient severity level, and sustained after nursing home placement or death of the patient.

CONCLUSIONS

Counseling and support lead to sustained benefits in reducing depressive symptoms in spouse-caregivers of Alzheimer's disease patients and should be widely available to provide effective, evidence-based intervention for family caregivers.

Acute rhabdomyolysis associated with cocaine intoxication

Because an increasing number of patients were arriving at our emergency room with cocaine intoxication and rhabdomyolysis, we reviewed our experience with such patients. We identified 39 patients seen at our institution over an eight-year period with acute rhabdomyolysis after cocaine use. The patients' mean creatine kinase level was 12,187 U per liter (range, 1756 to 85,000). Thirteen of the 39 patients (33 percent) had acute renal failure; 6 of them died. In comparison to the patients with normal renal function, those with renal failure were more often admitted with profound hypotension (46 vs. 4 percent; P less than 0.001), hyperpyrexia (69 vs. 15 percent; P less than 0.001), and markedly elevated serum creatine kinase levels (mean, 28,084 vs. 7931 U per liter; P less than 0.01). Disseminated intravascular coagulation developed in seven patients with renal failure. All six deaths were in this group. Severe hepatic dysfunction was found in 11 patients with renal failure. We conclude that cocaine intoxication can cause acute rhabdomyolysis with acute renal failure, severe liver dysfunction, and disseminated intravascular coagulation and that the mortality rate among patients with this syndrome is high.

Effects of DNA nonhomologous end-joining factors on telomere length and chromosomal stability in mammalian cells

DNA repair by nonhomologous end-joining (NHEJ) relies on the Ku70:Ku80 heterodimer in species ranging from yeast to man. In Saccharomyces cerevisiae and Schizosaccharomyces pombe, Ku also controls telomere functions. Here, we show that Ku70, Ku80, and DNA-PKcs, with which Ku interacts, associate in vivo with telomeric DNA in several human cell types, and we show that these associations are not significantly affected by DNA-damaging agents. We also demonstrate that inactivation of Ku80 or Ku70 in the mouse yields telomeric shortening in various primary cell types at different developmental stages. By contrast, telomere length is not altered in cells impaired in XRCC4 or DNA ligase IV, two other NHEJ components. We also observe higher genomic instability in Ku-deficient cells than in XRCC4-null cells. This suggests that chromosomal instability of Ku-deficient cells results from a combination of compromised telomere stability and defective NHEJ.

Social isolation, support, and capital and nutritional risk in an older sample: ethnic and gender differences

This study examines the relationships that exist between social isolation, support, and capital and nutritional risk in older black and white women and men. The paper reports on 1000 community-dwelling older adults aged 65 and older enrolled in the University of Alabama at Birmingham (UAB) Study of Aging, a longitudinal observational study of mobility among older black and white participants in the USA. Black women were at greatest nutritional risk; and black women and men were the groups most likely to be socially isolated and to possess the least amounts of social support and social capital. For all ethnic-gender groups, greater restriction in independent life-space (an indicator of social isolation) was associated with increased nutritional risk. For black women and white men, not having adequate transportation (also an indicator of social isolation) was associated with increased nutritional risk. Additionally, for black and white women and white men, lower income was associated with increased nutritional risk. For white women only, the perception of a low level of social support was associated with increased nutritional risk. For black men, not being married (an indicator of social support) and not attending religious services regularly, restricting activities for fear of being attacked, and perceived discrimination (indicators of social capital) were associated with increased nutritional risk. Black females had the greatest risk of poor nutritional health, however more indicators of social isolation, support, and capital were associated with nutritional risk for black men. Additionally, the indicators of social support and capital adversely affecting nutritional risk for black men differed from those associated with nutritional risk in other ethnic-gender groups. This research has implications for nutritional policies directed towards older adults.

Unexpected augmentation of mycophenolic acid pharmacokinetics in renal transplant patients receiving tacrolimus and mycophenolate mofetil in combination therapy, and analogous in vitro findings

Mycophenolate mofetil (MMF) a potent immunosuppressive agent, has recently been approved for clinical use (CellCept) in renal transplant patients in combination with cyclosporine (CsA). With the expanded use of tacrolimus (Prograf) as well in renal transplant patients, there is a lack of pharmacokinetic studies clarifying drug interactions between the three agents. A pharmacokinetic study was performed on 18 stable renal transplant patients receiving MMF and tacrolimus together, and four control groups, one receiving tacrolimus alone, two receiving CsA, in combination with MMF (1.0 or 1.5 g bid), and one receiving CsA microemulsion (Neoral). Area-under-the-curve values were calculated for each drug to assess if there was a reciprocal effect on the respective bioavailability of each. In vitro, the immunosuppressive effect of trough level plasma from each patient group was studied using mixed lymphocyte culture (MLC), as well as MLC reactions spiked with various combinations of each drug. There was a minimal effect of MMF on tacrolimus pharmacokinetics. However, patients receiving tacrolimus and MMF displayed significantly higher levels (Cmin and area under the curve) of mycophenolic acid (MPA) than those receiving CsA (Sandimmune or Neoral) and the same dose of MMF (50.2 +/- 16.5 vs 32.1 +/- 16.7 micrograms h/ml AUC, p < 0.02). Equivalent MPA levels could be attained in patients receiving CsA if the MMF dose was increased by 50% (1.5 g bid). There were also significantly lower levels of the glucuronide metabolite of MPA (MPAG) (755 +/- 280 vs 1230 +/- 250 micrograms h/ml AUC, p = 0.02), suggesting a specific inhibition (either direct or indirect) of the conversion of MPA to MPAG in tacrolimus patients, as opposed to those receiving CsA. For each drug combination, there was a positive correlation between the plasma immunosuppressive effect seen in MLC assays and the MMF dose. In addition, trough plasma from patients receiving tacrolimus and MMF was significantly more MLC inhibitory than from those receiving CsA or CsA microemulsion and equivalent-dose MMF. Culture media containing MPA and tacrolimus equal to clinical therapeutic trough concentrations (10 ng/ml) were significantly more MLC inhibitory than CsA at equivalent clinical therapeutic trough concentrations (200 ng/ml) with equivalent MPA levels. These studies in renal transplant patients suggest that tacrolimus in combination with MMF may result in a greater degree of immunosuppression than may be anticipated.

Cumulative meta-analysis of the relationship between useful field of view and driving performance in older adults: current and future implications

PURPOSE

Driving is a complex behavior that requires the utilization of a wide range of individual abilities. Identifying assessments that not only capture individual differences, but also are related to older adults' driving performance would be beneficial. This investigation examines the relationship between the Useful Field of View (UFOV) assessment and objective measures of retrospective or concurrent driving performance, including state-recorded accidents, on-road driving, and driving simulator performance.

METHOD

The PubMed and PsycINFO databases were searched to retrieve eight studies that reported bivariate relationships between UFOV and these objective driving measures. Cumulative meta-analysis techniques were used to combine the effect sizes in an attempt to determine whether the strength of the relationship was stable across studies and to assess whether a sufficient number of studies have been conducted to validate the relationship between UFOV and driving performance.

RESULTS

A within-group homogeneity of effect sizes test revealed that the samples could be thought of as being drawn from the same population, Q [7] = 11.29, p (one-tailed) = 0.13. Therefore, the effect sizes of eight studies were combined for the present cumulative meta-analysis. The weighted mean effect size across the studies revealed a large effect (Cohen's d = 0.945), with poorer UFOV performance associated with negative driving outcomes. This relationship was robust across multiple indices of driving performance and several research laboratories.

CONCLUSIONS

This convergence of evidence across numerous studies using different methodologies confirms the importance of the UFOV assessment as a valid and reliable index of driving performance and safety. Recent prospective studies have confirmed a relationship between UFOV performance and future crashes, further supporting the use of this instrument as a potential screening measure for at-risk older drivers.

Inflow stenosis in arteriovenous fistulas and grafts: a multicenter, prospective study

BACKGROUND

Traditionally, arteriovenous hemodialysis access inflow stenosis has been reported to occur infrequently (0% to 4%). In contrast, recent reports have suggested a significantly higher incidence (14% to 42%). Interpretation of these studies has been complicated by the presence of one or more confounding factors such as retrospective study design, small sample size, arteriovenous fistulas grouped with grafts to determine the incidence of inflow stenosis, inclusion of fistulas that had failed primarily, failure to provide adequate definition of inflow stenosis, and the technique of retrograde angiography. This is a report of a prospective, multicenter study to examine the incidence of inflow stenosis separately in arteriovenous fistulas and grafts.

METHODS

Patients were referred to interventional nephrology either for percutaneous balloon angioplasty or thrombectomy procedures. Angiography to evaluate access inflow (arterial anastomosis and adjacent vascular structures) was performed in all cases. This was accomplished by retrograde angiography using either manual occlusion of the venous side and/or advancing a diagnostic catheter across the arterial anastomosis. Multiple images using digital subtraction angiography were recorded in multiple planes. An inflow stenosis was defined as stenosis within the arterial system, artery-graft anastomosis (graft cases), artery-vein anastomosis (fistula cases) and juxta-anastomotic region (the first 2 cm downstream from the arterial anastomosis). Vascular stenosis was defined as >/=50% reduction in luminal diameter judged by comparison with either the adjacent vessel or graft. A standardized definition for anastomotic stenosis was applied.

RESULTS

Two hundred and twenty three consecutive procedures (grafts, 122; fistulas, 101) were performed in 158 patients. Inflow stenosis occurred in 36/122 (29%) in graft cases. All had a coexisting stenosis on the venous side. In fistula cases, 41/101 (40%) had inflow stenosis. Of these, 22 (54%) had a coexisting lesion on the venous side. Overall, inflow stenosis occurred in 77/223 procedures (35%).

CONCLUSION

This prospective, multicenter study demonstrates that access inflow stenosis occurs in one third of the cases referred to interventional facilities with clinical evidence of venous stenosis or thrombosis. This is much higher than has been traditionally reported.

A Randomized Trial of Three Renal Transplant Induction Antibodies: Early Comparison of Tacrolimus, Mycophenolate Mofetil, and Steroid Dosing, and Newer Immune-Monitoring1

BACKGROUND

New trends in immunosuppression in clinical transplantation include the use of antibody induction agents in protocols that emphasize reduction or avoidance of steroids and calcineurin inhibitors.

METHODS

In a randomized trial using three different antibody induction agents in 90 first renal transplant recipients from cadaver donors, group A received Thymoglobulin, group B received Alemtuzumab, and group C received Daclizumab. Maintenance immunosuppression included tacrolimus and mycophenolate in all three arms, and methylprednisolone in groups A and C only (standard clinical institutional practice). The targeted trough level of tacrolimus was between 8 and 10 ng/mL for groups A and C, respectively, with a targeted mycophenolate dose of 1 g twice daily. However, in group B, the target tacrolimus trough level was 4 to 7 ng/mL to reduce long-term nephrotoxicity, with 500 mg twice-daily doses of mycophenolate, without steroid maintenance.

RESULTS

In this 15-month median postoperative interval report, there were no notable differences in demographics and patient and graft survivals. Acute rejection rates at 1 year were equivalent, that is, 5 of 30 in all three groups (16.6%). In group B, there was slightly lower renal function at 1 month, but no difference at 1 year. There was also significantly more leukopenia, but a greater percentage of T-regulatory cells and number of Fox-P3 mRNA copies by flow cytometry and semiquantitative polymerase chain reaction analysis, respectively, in group B.

CONCLUSIONS

This preliminary analysis indicates that 80% of the patients in group B remained steroid-free 1 year postoperatively, with lower tacrolimus trough levels and no difference in other adverse events.

Behavioral training with and without biofeedback in the treatment of urge incontinence in older women: a randomized controlled trial

CONTEXT

Previous research on urge urinary incontinence has demonstrated that multicomponent behavioral training with biofeedback is safe and effective, yet it has not been established whether biofeedback is an essential component that heightens therapeutic efficacy.

OBJECTIVE

To examine the role of biofeedback in a multicomponent behavioral training program for urge incontinence in community-dwelling older women.

DESIGN

Prospective, randomized controlled trial conducted from April 1, 1995, to March 30, 2001.

SETTING

University-based outpatient continence clinic in the United States.

PATIENTS

A volunteer sample of 222 ambulatory, nondemented, community-dwelling women aged 55 to 92 years with urge incontinence or mixed incontinence with urge as the predominant pattern. Patients were stratified by race, type of incontinence (urge only vs mixed), and severity (frequency of accidents).

INTERVENTIONS

Patients were randomly assigned to receive 8 weeks (4 visits) of biofeedback-assisted behavioral training (n = 73), 8 weeks (4 visits) of behavioral training without biofeedback (verbal feedback based on vaginal palpation; n = 74), or 8 weeks of self-administered behavioral treatment using a self-help booklet (control condition; n = 75).

MAIN OUTCOME MEASURES

Reduction in the number of incontinence episodes as documented in bladder diaries, patients' perceptions and satisfaction, and changes in quality of life.

RESULTS

Intention-to-treat analysis showed that behavioral training with biofeedback yielded a mean 63.1% reduction (SD, 42.7%) in incontinence, verbal feedback a mean 69.4% reduction (SD, 32.7%), and the self-help booklet a mean 58.6% reduction (SD, 38.8%). The 3 groups were not significantly different from each other (P =.23). The groups differed significantly regarding patient satisfaction: 75.0% of the biofeedback group, 85.5% of the verbal feedback group, and 55.7% of the self-help booklet group reported being completely satisfied with treatment (P =.001). Significant improvements were seen across all 3 groups on 3 quality-of-life instruments, with no significant between-group differences.

CONCLUSIONS

Biofeedback to teach pelvic floor muscle control, verbal feedback based on vaginal palpation, and a self-help booklet in a first-line behavioral training program all achieved comparable improvements in urge incontinence in community-dwelling older women. Patients' perceptions of treatment were significantly better for the 2 behavioral training interventions.