Validity of the NIH toolbox cognitive battery in a healthy oldest-old 85+ sample.

OBJECTIVE: To evaluate the construct validity of the NIH Toolbox Cognitive Battery (NIH TB-CB) in the healthy oldest-old (85+ years old). METHOD: Our sample from the McKnight Brain Aging Registry consists of 179 individuals, 85 to 99 years of age, screened for memory, neurological, and psychiatric disorders. Using previous research methods on a sample of 85 + y/o adults, we conducted confirmatory factor analyses on models of NIH TB-CB and same domain standard neuropsychological measures. We hypothesized the five-factor model (Reading, Vocabulary, Memory, Working Memory, and Executive/Speed) would have the best fit, consistent with younger populations. We assessed confirmatory and discriminant validity. We also evaluated demographic and computer use predictors of NIH TB-CB composite scores. RESULTS: Findings suggest the six-factor model (Vocabulary, Reading, Memory, Working Memory, Executive, and Speed) had a better fit than alternative models. NIH TB-CB tests had good convergent and discriminant validity, though tests in the executive functioning domain had high inter-correlations with other cognitive domains. Computer use was strongly associated with higher NIH TB-CB overall and fluid cognition composite scores. CONCLUSION: The NIH TB-CB is a valid assessment for the oldest-old samples, with relatively weak validity in the domain of executive functioning. Computer use's impact on composite scores could be due to the executive demands of learning to use a tablet. Strong relationships of executive function with other cognitive domains could be due to cognitive dedifferentiation. Overall, the NIH TB-CB could be useful for testing cognition in the oldest-old and the impact of aging on cognition in older populations.

The Prognostic Value of Anti-PLA2R Antibodies Levels in Primary Membranous Nephropathy.

Anti-PLA2R antibodies (Ab) are a diagnostic and prognostic biomarker in primary membranous nephropathy (PMN). We assessed the relationship between the levels of anti-PLA2R Ab at diagnosis and different variables related to disease activity and prognosis in a western population of PMN patients. Forty-one patients with positive anti-PLA2R Ab from three nephrology departments in Israel were enrolled. Clinical and laboratory data were collected at diagnosis and after one year of follow-up, including serum anti-PLA2R Ab levels (ELISA) and glomerular PLA2R deposits on biopsy. Univariable statistical analysis and permutation-based ANOVA and ANCOVA tests were performed. The median [(interquartile range (IQR)) age of the patients was 63 [50-71], with 28 (68%) males. At the time of diagnosis, 38 (93%) of the patients had nephrotic range proteinuria, and 19 (46%) had heavy proteinuria (≥8 gr/24 h). The median [IQR] level of anti-PLA2R at diagnosis was 78 [35-183] RU/mL. Anti-PLA2R levels at diagnosis were correlated with 24 h proteinuria, hypoalbuminemia and remission after one year (p = 0.017, p = 0.003 and p = 0.034, respectively). The correlations for 24 h proteinuria and hypoalbuminemia remained significant after adjustment for immunosuppressive treatment (p = 0.003 and p = 0.034, respectively). Higher levels of anti-PLA2R Ab at diagnosis in patients with active PMN from a western population are associated with higher proteinuria, lower serum albumin and remission one year after the diagnosis. This finding supports the prognostic value of anti-PLA2R Ab levels and their possible use in stratifying PMN patients.

Spontaneous bone metastases in a preclinical orthotopic model of invasive lobular carcinoma; the effect of pharmacological targeting TGFß receptor I kinase.

Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the most frequently occurring histological subtypes of breast cancer, accounting for 80-90% and 10-15% of the total cases, respectively. At the time of diagnosis and surgical resection of the primary tumour, most patients do not have clinical signs of metastases, but bone micrometastases may already be present. Our aim was to develop a novel preclinical ILC model of spontaneous bone micrometastasis. We used murine invasive lobular breast carcinoma cells (KEP) that were generated by targeted deletion of E-cadherin and p53 in a conditional K14cre;Cdh1((F/F));Trp53((F/F)) mouse model of de novo mammary tumour formation. After surgical resection of the growing orthotopically implanted KEP cells, distant metastases were formed. In contrast to other orthotopic breast cancer models, KEP cells readily formed skeletal metastases with minimal lung involvement. Continuous treatment with SD-208 (60 mg/kg per day), an orally available TGFß receptor I kinase inhibitor, increased the tumour growth at the primary site and increased the number of distant metastases. Furthermore, when SD-208 treatment was started after surgical resection of the orthotopic tumour, increased bone colonisation was also observed (versus vehicle). Both our in vitro and in vivo data show that SD-208 treatment reduced TGFß signalling, inhibited apoptosis, and increased proliferation. In conclusion, we have demonstrated that orthotopic implantation of murine ILC cells represent a new breast cancer model of minimal residual disease in vivo, which comprises key steps of the metastatic cascade. The cancer cells are sensitive to the anti-tumour effects of TGFß. Our in vivo model is ideally suited for functional studies and evaluation of new pharmacological intervention strategies that may target one or more steps along the metastatic cascade of events.

Long-term safety and efficacy of dalfampridine for walking impairment in patients with multiple sclerosis: Results of open-label extensions of two Phase 3 clinical trials.

BACKGROUND: In Phase 3 double-blind trials (MS-F203 and MS-F204), dalfampridine extended release tablets 10 mg twice daily (dalfampridine-ER; prolonged-release fampridine in Europe; fampridine modified or sustained release elsewhere) improved walking speed relative to placebo in patients with multiple sclerosis (MS). OBJECTIVES: Evaluation of long-term safety and efficacy of dalfampridine-ER in open-label extensions (MS-F203EXT, MS-F204EXT). METHODS: Patients received dalfampridine-ER 10 mg twice daily; and had Timed 25-Foot Walk (T25FW) assessments at 2, 14 and 26 weeks, and then every 6 months. Subjects were categorized as dalfampridine-ER responders or non-responders, based on their treatment response in the double-blind parent trials that assessed T25FW. RESULTS: We had 269 patients enter MS-F203EXT and 154 patients complete it; for a maximum exposure of 5 years. We had 214 patients enter MS-F204EXT and 146 complete it; for a maximum exposure of 3.3 years. No new safety signals emerged and dalfampridine-ER tolerability was consistent with the double-blind phase. Improvements in walking speed were lost after dalfampridine-ER was discontinued in the parent trial, but returned by the 2-week assessment after re-initiation of the drug. Throughout the extensions, mean improvement in walking speed declined, but remained improved, among the double-blind responders as compared with non-responders. CONCLUSIONS: The dalfamipridine-ER safety profile was consistent with the parent trials. Although walking speed decreased over time, dalfampridine-ER responders continued to show improved walking speed, which was sustained compared with non-responders.

Effect of a 24-Month Physical Activity Intervention vs Health Education on Cognitive Outcomes in Sedentary Older Adults: The LIFE Randomized Trial.

IMPORTANCE: Epidemiological evidence suggests that physical activity benefits cognition, but results from randomized trials are limited and mixed. OBJECTIVE: To determine whether a 24-month physical activity program results in better cognitive function, lower risk of mild cognitive impairment (MCI) or dementia, or both, compared with a health education program. DESIGN, SETTING, AND PARTICIPANTS: A randomized clinical trial, the Lifestyle Interventions and Independence for Elders (LIFE) study, enrolled 1635 community-living participants at 8 US centers from February 2010 until December 2011. Participants were sedentary adults aged 70 to 89 years who were at risk for mobility disability but able to walk 400 m. INTERVENTIONS: A structured, moderate-intensity physical activity program (n = 818) that included walking, resistance training, and flexibility exercises or a health education program (n = 817) of educational workshops and upper-extremity stretching. MAIN OUTCOMES AND MEASURES: Prespecified secondary outcomes of the LIFE study included cognitive function measured by the Digit Symbol Coding (DSC) task subtest of the Wechsler Adult Intelligence Scale (score range: 0-133; higher scores indicate better function) and the revised Hopkins Verbal Learning Test (HVLT-R; 12-item word list recall task) assessed in 1476 participants (90.3%). Tertiary outcomes included global and executive cognitive function and incident MCI or dementia at 24 months. RESULTS: At 24 months, DSC task and HVLT-R scores (adjusted for clinic site, sex, and baseline values) were not different between groups. The mean DSC task scores were 46.26 points for the physical activity group vs 46.28 for the health education group (mean difference, -0.01 points [95% CI, -0.80 to 0.77 points], P = .97). The mean HVLT-R delayed recall scores were 7.22 for the physical activity group vs 7.25 for the health education group (mean difference, -0.03 words [95% CI, -0.29 to 0.24 words], P = .84). No differences for any other cognitive or composite measures were observed. Participants in the physical activity group who were 80 years or older (n = 307) and those with poorer baseline physical performance (n = 328) had better changes in executive function composite scores compared with the health education group (P = .01 for interaction for both comparisons). Incident MCI or dementia occurred in 98 participants (13.2%) in the physical activity group and 91 participants (12.1%) in the health education group (odds ratio, 1.08 [95% CI, 0.80 to 1.46]). CONCLUSIONS AND RELEVANCE: Among sedentary older adults, a 24-month moderate-intensity physical activity program compared with a health education program did not result in improvements in global or domain-specific cognitive function. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01072500.

Patterns of white matter injury in HIV infection after partial immune reconstitution: a DTI tract-based spatial statistics study.

HIV-infected individuals with severe immune suppression are more likely to develop HIV-associated neurocognitive disorders than those with preserved immune function. While partial immune reconstitution occurs in those with severe immune suppression after starting combined antiretroviral therapy, it is not established whether improvement in immune function reverses or prevents injury to the central nervous system (CNS). To address this question, 50 participants (nadir CD4 counts ≤ 200 cells/mm(3), on a stable antiretroviral regimen for at least 12 consecutive weeks prior to study) and 13 HIV negative participants underwent a comprehensive neurological evaluation followed by diffusion tensor imaging (DTI). Eighty-four percent of the 50 HIV participants were neurologically asymptomatic (HIVNA) and 16 % had mild cognitive impairment (HIVCI). Tract-based spatial statistics (TBSS) on DTI data revealed that mean diffusivity (MD) increased significantly in the posterior aspect of both hemispheres in HIVNA compared to controls. In HIVCI, compared to controls and HIVNA, increased MD extended to prefrontal areas. Fractional anisotropy decreased only in HIVCI, compared to either controls or HIVNA. Furthermore, DTI showed significant correlations to duration of HIV infection and significant associations with multiple cognitive domains. This study highlights that in partial immune reconstitution, injury to the CNS is present even in those that are neurologically asymptomatic and there are discrete spatial patterns of white matter injury in HIVNA subjects compared to HIVCI subjects. Our results also show that quantitative analysis of DTI using TBSS is a sensitive approach to evaluate HIV-associated white matter disease and thus valuable in monitoring central nervous system injury.

Marked heterogeneity in growth characteristics of myoblast clonal cultures and myoblast mixed cultures obtained from the same individual.

BACKGROUND: Sarcopenia is defined as an age-related decrease in skeletal muscle mass and function while adjacent satellite cells are unable to compensate for this loss. However, myoblast cultures can be established even in the presence of sarcopenia. OBJECTIVE: It is yet unknown whether satellite cells from failing muscle in older age are equally affected, as human satellite cells have been assessed using myoblast mixed cultures and not by using myoblast clonal cultures. We questioned to what extent myoblast mixed cultures reflect the in vivo characteristics of single satellite cells from adult skeletal muscle. METHODS: We established a myoblast mixed culture and three myoblast clonal cultures out of the same muscle biopsy and cultured these cells for 100 days. Replicative capacity and oxidative stress resistance were compared. RESULTS: We found marked heterogeneity between the myoblast clonal cultures that all had a significantly lower replicative capacity when compared to the mixed culture. Replicative capacity of the clonal cultures was inversely related to the ß-galactosidase activity after exposure to oxidative stress. Addition of L-carnosine enhanced the remaining replicative capacity in all cultures with a concomitant marginal decrease in ß-galactosidase activity. CONCLUSIONS: It is concluded that myoblast mixed cultures in vitro do not reflect the marked heterogeneity between single isolated satellite cells. The consequences of the heterogeneity on muscle performance remain to be established.

A phase 3 trial of extended release oral dalfampridine in multiple sclerosis.

OBJECTIVE: A previous phase 3 study showed significant improvement in walking ability in multiple sclerosis (MS) patients treated with oral, extended-release dalfampridine (4-aminopyridine) 10mg twice daily. The current study was designed to confirm efficacy and further define safety and pharmacodynamics. METHODS: This was a 39-center, double-blind trial in patients with definite MS of any course type. Participants were randomized to 9 weeks of treatment with dalfampridine (10mg twice daily; n = 120) or placebo (n = 119). Response was defined as consistent improvement on the Timed 25-Foot Walk, with percentage of timed walk responders (TWRs) in each treatment group as the primary outcome. The last on-treatment visit provided data from 8 to 12 hours postdose, to examine maintenance of effect. RESULTS: One patient from each group was excluded from the modified Intention to Treat population. The proportion of TWRs was higher in the dalfampridine group (51/119 or 42.9%) compared to the placebo group (11/118 or 9.3%, p < 0.0001). The average improvement in walking speed among dalfampridine-treated TWRs during the 8-week efficacy evaluation period was 24.7% from baseline (95% confidence interval, 21.0-28.4%); the mean improvement at the last on-treatment visit was 25.7%, showing maintenance of effect over the interdosing period. There were no new safety findings. INTERPRETATION: This interventional study provides class 1 evidence that dalfampridine extended-release tablets produce clinically meaningful improvement in walking ability in a subset of people with MS, with the effect maintained between doses.

Sustained-release oral fampridine in multiple sclerosis: a randomised, double-blind, controlled trial.

BACKGROUND: Clinical studies suggested that fampridine (4-aminopyridine) improves motor function in people with multiple sclerosis. This phase III study assessed efficacy and safety of oral, sustained-release fampridine in people with ambulatory deficits due to multiple sclerosis. METHODS: We undertook a randomised, multicentre, double-blind, controlled phase III trial. We randomly assigned 301 patients with any type of multiple sclerosis to 14 weeks of treatment with either fampridine (10 mg twice daily; n=229) or placebo (n=72), using a computer-generated sequence stratified by centre. We used consistent improvement on timed 25-foot walk to define response, with proportion of timed walk responders in each treatment group as the primary outcome. We used the 12-item multiple sclerosis walking scale to validate the clinical significance of the response criterion. Efficacy analyses were based on a modified intention-to-treat population (n=296), which included all patients with any post-treatment efficacy data. The study is registered with ClinicalTrials.gov, number NCT00127530. FINDINGS: The proportion of timed walk responders was higher in the fampridine group (78/224 or 35%) than in the placebo group (6/72 or 8%; p<0.0001). Improvement in walking speed in fampridine-treated timed walk responders, which was maintained throughout the treatment period, was 25.2% (95% CI 21.5% to 28.8%) and 4.7% (1.0% to 8.4%) in the placebo group. Timed walk responders showed greater improvement in 12-item multiple sclerosis walking scale scores (-6.84, 95% CI -9.65 to -4.02) than timed walk non-responders (0.05, -1.48 to 1.57; p=0.0002). Safety data were consistent with previous studies. INTERPRETATION: Fampridine improved walking ability in some people with multiple sclerosis. This improvement was associated with a reduction of patients' reported ambulatory disability, and is a clinically meaningful therapeutic benefit.

The Historical Progression From ADL Scrutiny to IADL to Advanced ADL: Assessing Functional Status in the Earliest Stages of Dementia.

Background: Decrements in instrumental activities (IADL) have been observed in the prodromal phase of dementia. Given the long predementia stage in neurodegenerative diseases, it has been proposed that subtle functional changes may precede clinical IADL impairment. Incorporating more challenging advanced ADLs (eg, volunteer work) into the assessment process may increase the sensitivity of functional measures, thus expanding the window for monitoring or interventions. Methods: Longitudinal cohort study was used (follow-ups, 18-24 month), with subjects aged 60 and older (n = 3,635). To elucidate the relationship between cognitive ability and functional status we employed an IADL scale with an extended range (ADL-extended; includes IADL but also more challenging advanced ADLs) that meets item response theory properties of dimensionality, monotonicity, and item hierarchy. Procedures involved (a) a dynamic change model employed to inspect the temporal relationship between ADL-extended and cognitive status and (b) Cox proportional hazards to assess the risk of incident dementia based on ADL-extended scores. Results: Growth curve modeling: baseline ADL-extended was significantly associated with all four cognitive domains investigated. Worse baseline ADL-extended was associated with more rapid declines in speed/executive function, and worse baseline memory was associated with more rapid declines in ADL-extended; a concurrent association was found for language and ADL-extended. Cox model: the risk of dementia was decreased for each additional ADL-extended item endorsed (hazard ratio [HR], 0.85; 95% confidence interval = 0.81-0.90). Conclusions: An increased risk of dementia could be observed in the ADL-extended items, which reflects an area of the functional continuum beyond IADL competencies.

Discrepancies between crystallized and fluid ability are associated with frequency of social and physical engagement in community dwelling older adults.

OBJECTIVE: Age differences have been noted in the discrepancies between crystallized and fluid ability (Gc-Gf). Larger Gc-Gf discrepancies have also been shown to be associated with Alzheimer's disease biomarkers and clinical severity. However, little is known regarding the relationship between Gc-Gf discrepancies in normal aging and functional outcomes. The aim of the present study was to examine this. METHOD: Data from 104 adults (Mage = 71.70 years, SD = 9.016) were included in the present study. Measures from the NIH toolbox were used to form the discrepancy scores. Physical, cognitive, and social activities were identified using the Community Healthy Activities Model Program for Seniors activity questionnaire. Linear regression analyses, controlling for age, education, gender, health, and depressive symptoms, were used to examine the association between social, cognitive, and physical activities on Gc-Gf discrepancies. RESULTS: Results showed that social and physical activity were significantly associated with greater discrepancies between crystallized and fluid ability, independent of covariates. There was no association between cognitive activity and Gc-Gf discrepancies. CONCLUSIONS: Larger discrepancies between crystallized and fluid ability are related to frequency of social and physical activity. The findings support previous research that discrepancy scores may serve as a marker of cognitive decline. In more highly educated older individuals, Gc-Gf discrepancies may be a more accurate indicator of actual cognitive status.

Pharmacokinetic studies of single and multiple oral doses of fampridine-SR (sustained-release 4-aminopyridine) in patients with chronic spinal cord injury.

Fampridine (4-aminopyridine) is a potassium channel blocking agent that restores conduction in demyelinated axons and improves neurologic function in patients with chronic spinal cord injury (SCI). Based on the pharmacokinetic profile of orally administered fampridine, multiple daily doses (4 or more) would need to be taken to sustain its therapeutic effects. Two studies were conducted to determine the pharmacokinetics and safety profile of an oral, sustained-release (SR) formulation of fampridine (fampridine-SR, 10-25 mg) administered as a single dose (n = 14) and twice daily for 1 week (n = 16) in patients with chronic, incomplete SCI. Mean plasma concentrations and area under the plasma concentration-time curve were proportional to the dose administered, whereas other pharmacokinetic parameters were independent of dose. Fampridine-SR was absorbed slowly (peak plasma concentration shortly after dosing, 2.6-3.7 hours) and eliminated (plasma half-life, 5.6-7.6 hours), and reached steady state after 4 days of twice-daily administration. Fampridine-SR was well tolerated, with only mild to moderate adverse events reported, and no serious adverse events. The extended plasma half-life of fampridine-SR allows convenient twice-daily dosing. Clinical trials designed to assess neurologic and functional improvement using fampridine-SR in patients with chronic SCI are currently underway.

Development of dalfampridine, a novel pharmacologic approach for treating walking impairment in multiple sclerosis.

Walking impairment is a clinical hallmark of multiple sclerosis (MS). Dalfampridine-ER, an extended-release formulation of dalfampridine (also known by its chemical name, 4-aminopyridine, and its international nonproprietary name, fampridine), was developed to maintain drug plasma levels within a narrow therapeutic window, and assessed for its ability to improve walking in MS. The putative mechanism of action of dalfampridine-ER is restoration of axonal conduction via blockade of the potassium channels that become exposed during axonal demyelination. Two pivotal phase III clinical trials demonstrated that dalfampridine-ER 10-mg tablets administered twice daily improved walking speed and patient-reported perceptions of walking in some patients. Dalfampridine-ER was generally well tolerated, and, at the approved dose, risk of seizure was neither elevated relative to placebo nor higher than the rate in the MS population. Dalfampridine-ER (AMPYRA®) was approved in the United States for the treatment of walking in patients with MS as demonstrated by an increase in walking speed. The use of the dalfampridine-ER is contraindicated in patients with a history of seizure. It is the first pharmacologic therapy for this indication and has been incorporated into clinical management of MS.