A multicenter, randomized phase 2 study to establish combinations of CBP501, cisplatin and nivolumab for ≥3rd-line treatment of patients with advanced pancreatic adenocarcinoma

BACKGROUND

There is no standard of care for ≥ 3rd-line treatment of metastatic pancreatic adenocarcinoma (PDAC). CBP501 is a novel calmodulin-binding peptide that has been shown to enhance the influx of platinum agents into tumor cells and tumor immunogenicity. This study aimed to (1) confirm efficacy of CBP501/cisplatin/nivolumab for metastatic PDAC observed in a previous phase 1 study, (2) identify combinations that yield 35% 3-month progression-free survival rate (3MPFS) and (3) define the contribution of CBP501 to the effects of combination therapy.

METHODS

CBP501 16 or 25 mg/m2 (CBP(16) or CBP(25)) was combined with 60 mg/m2 cisplatin (CDDP) and 240 mg nivolumab (nivo), administered at 3-week intervals. Patients were randomized 1:1:1:1 to (1) CBP(25)/CDDP/nivo, (2) CBP(16)/CDDP/nivo, (3) CBP(25)/CDDP and (4) CDDP/nivo, with randomization stratified by ECOG PS and liver metastases. A Fleming two-stage design was used, yielding a one-sided type I error rate of 2.5% and 80% power when the true 3MPFS is 35%.

RESULTS

Among 36 patients, 3MPFS was 44.4% in arms 1 and 2, 11.1% in arm 3% and 33.3% in arm 4. Two patients achieved a partial response in arm 1 (ORR 22.2%; none in other arms). Median PFS and OS were 2.4, 2.1, 1.5 and 1.5 months and 6.3, 5.3, 3.7 and 4.9 months, respectively. Overall, all treatment combinations were well tolerated. Most treatment-related adverse events were grade 1-2.

CONCLUSIONS

The combination CBP(25)/(16)/CDDP/nivo demonstrated promising signs of efficacy and a manageable safety profile for the treatment of advanced PDAC.

CLINICAL TRIAL REGISTRATION

NCT04953962.

On the Origin and Evolution of the Mosquito Male-determining Factor Nix

The mosquito family Culicidae is divided into 2 subfamilies named the Culicinae and Anophelinae. Nix, the dominant male-determining factor, has only been found in the culicines Aedes aegypti and Aedes albopictus, 2 important arboviral vectors that belong to the subgenus Stegomyia. Here we performed sex-specific whole-genome sequencing and RNAseq of divergent mosquito species and explored additional male-inclusive datasets to investigate the distribution of Nix. Except for the Culex genus, Nix homologs were found in all species surveyed from the Culicinae subfamily, including 12 additional species from 3 highly divergent tribes comprising 4 genera, suggesting Nix originated at least 133 to 165 million years ago (MYA). Heterologous expression of 1 of 3 divergent Nix open reading frames (ORFs) in Ae. aegypti resulted in partial masculinization of genetic females as evidenced by morphology and doublesex splicing. Phylogenetic analysis suggests Nix is related to femaleless (fle), a recently described intermediate sex-determining factor found exclusively in anopheline mosquitoes. Nix from all species has a conserved structure, including 3 RNA-recognition motifs (RRMs), as does fle. However, Nix has evolved at a much faster rate than fle. The RRM3 of both Nix and fle are distantly related to the single RRM of a widely distributed and conserved splicing factor transformer-2 (tra2). The RRM3-based phylogenetic analysis suggests this domain in Nix and fle may have evolved from tra2 or a tra2-related gene in a common ancestor of mosquitoes. Our results provide insights into the evolution of sex determination in mosquitoes and will inform broad applications of mosquito-control strategies based on manipulating sex ratios toward nonbiting males.

Differences in Habitual and Maximal Gait Velocity Across Age Groups: A Cross-Sectional Examination

Prior work, primarily focusing on habitual gait velocity, has demonstrated a cost while walking when coupled with a cognitive task. The cost of dual-task walking is exacerbated with age and complexity of the cognitive or motor task. However, few studies have examined the dual-task cost associated with maximal gait velocity. Thus, this cross-sectional study examined age-related changes in dual-task (serial subtraction) walking at two velocities. Participants were classified by age: young-old (45-64 years), middle-old (65-79 years), and oldest-old (≥80 years). They completed single- and dual-task walking trials for each velocity: habitual (N = 217) and maximal (N = 194). While no significant Group × Condition interactions existed for habitual or maximal gait velocities, the main effects for both condition and age groups were significant (p < .01). Maximal dual-task cost (p = .01) was significantly greater in the oldest-old group. With age, both dual-task velocities decreased. Maximal dual-task cost was greatest for the oldest-old group.

A Novel Digital Digit-Symbol Substitution Test Measuring Processing Speed in Adults At Risk for Alzheimer Disease: Validation Study

BACKGROUND

Assessing cognitive constructs affected by Alzheimer disease, such as processing speed (PS), is important to screen for potential disease and allow for early detection. Digital PS assessments have been developed to provide widespread, efficient cognitive testing, but all have been validated only based on the correlation between test scores. Best statistical practices dictate that concurrent validity should be assessed for agreement or equivalence rather than using correlation alone.

OBJECTIVE

This study aimed to assess the concurrent validity of a novel digital PS assessment against a gold-standard measure of PS.

METHODS

Adults aged 45-75 years (n=191) participated in this study. Participants completed the novel digital digit-symbol substitution test (DDSST) and the Repeatable Battery for the Assessment of Neuropsychological Status coding test (RBANS-C). The correlation between the test scores was determined using a Pearson product-moment correlation, and a difference in mean test scores between tests was checked for using a 2-tailed dependent samples t test. Data were analyzed for agreement between the 2 tests using Bland-Altman limits of agreement and equivalency using a two one-sided t tests (TOST) approach.

RESULTS

A significant moderate, positive correlation was found between DDSST and RBANS-C scores (r=.577; P<.001), and no difference in mean scores was detected between the tests (P=.93). Bias was nearly zero (0.04). Scores between the tests were found to display adequate agreement with 90% of score differences falling between -22.66 and 22.75 (90% limits of agreement=-22.91 to 22.99), and the scores were equivalent (P=.049).

CONCLUSIONS

Analyses indicate that the DDSST is a valid digital assessment of PS. The DDSST appears to be a suitable option for widespread, immediate, and efficient PS testing.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04559789; https://clinicaltrials.gov/ct2/show/NCT04559789.

HIGHER PHYSICAL FITNESS CLUSTERS SHOWED GREATER GLOBAL COGNITIVE OUTCOMES IN MIDDLE- TO OLDER-AGED ADULTS

Approximately, 6 million individuals in the United States are living with Alzheimer’s disease. A new diagnosis occurs every 67 seconds, which will triple the rates by 2050. Recently, physical dysfunction has been associated with cognitive decline; however, usually, this is examined in one dimension of physical fitness (PF). A more robust way including multiple domains of PF would be beneficial in examining the relationship between PF and cognition. Therefore, the purpose of this investigation was to examine cognition in clustered PF variables among middle to older-aged adults. Participants (n=216;73% female) enrolled and completed a DXA scan, RBANS, handgrip, sit-to-stand power with TENDO, dual-task (4-meter and 10-meter), and 6-minute walk distance test. A hierarchal cluster analysis was utilized to identify PF cluster for participants, a one-way ANOVA was used to assess differences in cognition between clusters. Cluster 1 (C1;n=29) was characterized with the highest physical fitness values, cluster 2 (C2;n=74) was in-between C1 and C3, cluster 3 (C3;n=113) had the lowest values among PF variables. C1 had significantly higher global cognitive and visuospatial scores compared to C3 (p< 0.05). C1 and C2 had significantly higher values on line orientation and figure recall than C3 (p< 0.05). Data showed high PF clusters had higher global cognitive values when compared to lower PF clusters. Moreover, higher PF showed greater visuospatial and delayed memory values compared to lower PF. Clustering PF tasks served as a practical tool evaluating cognition—this may be useful for future interpretation of cognitive decline where higher PF represents higher overall cognition.

ASSOCIATIONS BETWEEN MEASURES OF SLEEP QUALITY, PHYSICAL ACTIVITY, ANXIETY, AND STRESS AMONG ADULTS

Good quality sleep is important for physical and mental well-being and plays a vital role in healthy aging. Additionally, sleep quality is influenced by multiple factors associated with aging, such as lifestyle, depression, and physical activity levels. Therefore, the purpose of this study was to explore the relationship between self-reported measures of physical activity levels, anxiety, stress, and sleep quality among adults aged 45-75 years. Adults (N = 204) completed the short form International Physical Activity Questionnaire (IPAQ), Generalized Anxiety Disorder 7-Item Scale (GAD-7), Perceived Stress Scale (PSS), and the Pittsburgh Sleep Quality Index (PSQI). Participants were classified as either good quality sleepers (GQS, n = 65, 67.7% female, M±SD: age: 61.7±8.9 yrs; mass: 82.8±16.7 kg, height: 169.6±10.2 cm, education: 17.3 yrs) or poor quality sleepers (PQS, n = 139, 77.7% female, M±SD: age: 61.9±8.0 yrs; mass: 83.1±16.2 kg, height: 166.4±8.5 cm, education: 18.0 yrs) using their PSQI global score. A score of ≥5 denoted PQS. Data were analyzed using descriptive statistics, Spearman correlation, and Chi-square (p ≤ .05). Sleep quality was negatively associated with the PSS (r = -.17, p = .02) and GAD-7 (r = -.19, p < .01). Adults reporting PQS presented with higher levels of perceived stress and generalized anxiety. The relation between sleep quality and IPAQ was significant (X2 = 8.47, p = .01). These results suggest there was a greater tendency for PQS to report lower levels of physical activity and higher levels of stress and generalized anxiety.

THE COMPARISON OF DUAL TASK TIME AMONG APOE CARRIERS AGAINST NON-APOE CARRIERS IN AGING ADULTS

No single variable has been identified as the sole factor for predicting an individuals’ declining health status. In order to predict mental or physical decline in older adults, researchers have designed tasks that include both a physical and mental or cognitive demand known as dual task (DT). The purpose of implementing dual task is to assess the possible changes in accuracy when a second task gets compounded with a given single task. Our study consists of males and females aged from 45 to 75 years who have risk factors for dementia. Each subject was randomly assigned to either a health coaching (HC), or health education (HE) control group. The HC group received coaching to address the lifestyle areas known to be linked to AD risk, such as diet, exercise, sleep, stress, cognitive training, and social interaction. Blood markers of each individual have been assessed to determine carrier status of Apolipoprotein E 4 (APOE4) due to the correlation between the allele and increased risk of Alzheimer’s. To be included in the study, the participants must have at least 2 positive risk factors for AD as determined by the Australian National University-Alzheimer Disease Risk Index (ANU-ADRI). Among non-APOE carriers, a 2x3 (group x time) mixed ANOVA revealed a significant interaction effect wherein the HC group improved DTC score more than the HE group from time 1 to time 3, F (2, 362) =1.253, P=0.017. No significant interaction was noted for APOE carriers.

Effects of fundamental movement skills based dual-task and dance training on single- and dual-task walking performance in older women with dementia

OBJECTIVE

The purpose of this study was to compare the effects of fundamental movement skills (FMS)-based dual-task training and dance training on spatio-temporal characteristics of gait performance under single- and dual-task walking conditions among older women with dementia.

METHOD

Thirty-eight elderly females with dementia were randomly assigned to one of two groups: (1) dual-task intervention (DTI, age: 73 ± 6.5 years) or (2) Iranian dance intervention (IDI, age: 72.52 ± 6.01 years). Both groups participated in a 10-week intervention program (3 sessions per week, each lasting 50 min). Gait performance parameters (gait speed, cadence, and stride length) and dual-task costs (DTC) were examined using a gait analysis system. The participants completed three walking trials under two conditions: single- and dual-task. The video data was analyzed using motion analysis software (Frame-DIAS II, DKH, DKH Inc., Tokyo, Japan).

RESULTS

The results showed that both groups significantly improved in terms of all gait variables, and DTC decreased (p < .001) from pre- to post-test for both conditions. However, the main effects for the group and the group-by-time interactions were not significantly different between the two groups (p > .05).

CONCLUSION

These findings showed that DTI and IDI effectively improved gait performance following a 10-week intervention for older women with dementia. Therefore, it is suggested that either training program could decrease DTC and increase gait speed, stride length, and cadence among older females with dementia.

Intervention for a Digital, Cognitive, Multi-Domain Alzheimer Risk Velocity Study: Protocol for a Randomized Controlled Trial

Background

In the United States, more than 6 million adults live with Alzheimer disease (AD) that affects 1 out of every 3 older adults. Although there is no cure for AD currently, lifestyle-based interventions aimed at slowing the rate of cognitive decline or delaying the onset of AD have shown promising results. However, most studies primarily focus on older adults (>55 years) and use in-person interventions.

Objective

The aim of this study is to determine the effects of a 2-year digital lifestyle intervention on AD risk among at-risk middle-aged and older adults (45-75 years) compared with a health education control.

Methods

The lifestyle intervention consists of a digitally delivered, personalized health coaching program that directly targets the modifiable risk factors for AD. The primary outcome measure is AD risk as determined by the Australian National University-Alzheimer Disease Risk Index; secondary outcome measures are functional fitness, blood biomarkers (inflammation, glucose, cholesterol, and triglycerides), and cognitive function (Repeatable Battery for the Assessment of Neuropsychological Status and Neurotrack Cognitive Battery). Screening commenced in January 2021 and was completed in June 2021.

Results

Baseline characteristics indicate no difference between the intervention and control groups for AD risk (mean −1.68, SD 7.31; P=.90).

Conclusions

The intervention in the Digital, Cognitive, Multi-domain Alzheimer Risk Velocity is uniquely designed to reduce the risk of AD through a web-based health coaching experience that addresses the modifiable lifestyle-based risk factors.

Trial Registration

ClinicalTrials.gov NCT04559789; https://clinicaltrials.gov/show/NCT04559789

International Registered Report Identifier (IRRID)

DERR1-10.2196/31841

Sex differences in power decrement identified across the lifespan

Muscular power has been shown to be a significant predictor of physical function in older adults, but assessments of power have traditionally been performed in movements not specific to activities of daily living (ADLs). Recent research examined power in the context of ADL-specific movements, but it is unclear how ADL-specific lower-body power differs over lifespan in males and females. This investigation sought to describe ADL-specific power decline across the lifespan and analyze differences between the sexes. Adults (n = 557) aged 18-89 volunteered and were divided into age cohorts (18-30, 50-59, 60-69, 70-79, and 80-89 years). Participants performed a sit-to-stand (STS) task with as much velocity as possible while connected to a linear position transducer (LPT). The LPT calculated average and peak power. The average result of 5 individual STS trials was analyzed for each of the power variables. The first significant decrement in average STS power (p &lt; .01) was observed at an earlier age cohort in males than females (60-69 in males vs. 70-79 in females). The per decade magnitude of power decrement after age 60 was larger in males than females in both absolute magnitude and percent decrease (11.74 vs. 10.09% decrease per decade). As power and physical function are correlated, this may have implications for the rate and age of functional decline in males. Additionally, understanding the differences in ADL-specific power decline between males and females gives clinicians and health professionals valuable information for developing preventative fitness paradigms specific to members of a given sex.

Dual-task gait speed and mobility are positively associated with declarative memory

In the US, it is not recommended to perform routine screening assessments for cognitive function or impairment among older adults, due to the lack of effective pharmacological treatments. These common practices result in delayed identification and treatments for slowing cognitive decline progression. Thus, the purpose of the present investigation was to determine the ability to predict cognition from common measures of physical function. Seventy-five community-dwelling older adults (80.7±5.4 years) completed physical function and cognitive assessments. Physical function was assessed using the Short Physical Performance Battery (SPPB), peak velocity during a power sit-to-stand task, and dual-task walking test. Cognition (declarative memory) was assessed using a validated Visual Paired Comparison test. 38% of the variance in cognition was accounted for by the predictor variables (age, sex, education, SPPB, dual-task, peak velocity). Significant predictors included dual-task walking (p = .03), SPPB (p = .02), and education (p = .02). For each 1 second faster during the dual-task performance, cognition increased by 4 percentile units. Likewise, each 1 unit increase in SPPB resulted in an increase of 4 percentile points in cognition. The results indicate more than a third of the variance in declarative memory can be predicted by commonly assessed measures of physical function. This information is useful when identifying older adults that may have cognitive impairment before overt signs are realized. With the lack of recommended cognitive testing, using physical function declines to identify possible cognitive decline is promising. These results are preliminary in nature and longitudinal determination is warranted.

Cardiometabolic risk factors predict executive function scores in high-risk individuals

Alzheimer’s disease (AD) is expected to triple by 2050, affecting 16 million Americans. As a result, it is essential to combat this alarming increase in cognitive impairment through early detection. Cardiometabolic risk factors have shown to be associated with higher risk of AD. The purpose of this study was to determine if cardiometabolic risk factors could predict executive function scores in a high-risk population. Fifty (60.9±8.8 years) high-risk adults (classified by the Australian National University Alzheimer’s Disease Risk Index) were enrolled in this study. Participants completed a 6-minute walking test, venous blood draw, blood pressure measurement, and the digit coding symbol test (DCS). Results were examined through a multiple linear regression with DCS as the dependent variable and age, sex, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), glucose, 6-minute walking test, systolic blood pressure (SBP), and diastolic blood pressure (DBP) as predictor variables. The model explained 42% of the variance of DCS (p = .04) with SBP (45%; p = .003) as a significant predictor. LDL (p = .087) and DBP (p = .123) accounted for 24% and 22% of the variance for this model, respectively. These results suggest cardiometabolic risk factors predict executive function values in high-risk individuals. Higher SBP was significantly associated with lower DCS scores indicating SBP as a valuable tool for practitioners when evaluating cognitive decline. Further research should expand sample size and track values longitudinally to substantiate these claims.

Dual-Task Costs in Gait Speed Differs Across Age Groups

With age, there are simultaneous reductions in gait speed (GS). This decrease in GS has been associated with an increased fall risk and negatively impacts independence. Further, GS naturally declines with the addition of a secondary stimulus (i.e., cognitive requirements). Combined, these decrements can be additive in nature potentially leading to robust declines with advancing age. Therefore, the aim of this study was to examine age-related effects of dual-task cost (DTC) while walking. Adults (N = 145), over the age of 45 years, completed two walking trials for each GS condition: habitual (HAB) and fast (FST), with and without a DT (i.e., counting backwards by serials of three). Subjects were classified into four age groups: youngest-old (YG ≤ 64 years, n = 24), young-old (YO, 65-74 years, n = 46), middle-old (MO = 75-84 years, n = 54), and oldest-old (OO ≥ 85 years, n = 21). DTC was calculated and ANOVAs were used to assess differences between the groups. There was no difference in HAB DTC between the age groups (p=.61). However, there was a significant difference in FST DTC (p=.04) between the YO (M±SD: -14 ± -11%) and OO (M±SD: -24 ± -12%). These data indicate there was an age-related affect for fast dual-task cost, but not for habitual dual-task cost while walking. An increase in dual-task cost among the oldest-old may be associated with an inability to properly maintain a faster cadence while performing an arithmetic task which may be related to task prioritization.

The Effects of Mild Cognitive Impairment on Fall Severity in Older Adults

Falls affect more than 30% of older adults and are one of the leading causes of injury, hospitalization, and mortality in this populations. Mild cognitive impairment (MCI) is one of the risk factors for falls in older adults. The purpose of this study is to determine if older adults with MCI have increased fall severity than older adults without MCI. Participants (n: 81: age: 79 ± 6) completed a Montreal Cognitive Assessment (MoCA) and a Hopkins Falls Grading Scale, a tool used to grade the severity of falls on a scale of 1-4 (1 = loss of balance without fall; 4 = fall requiring hospital admission). Participants were categorized as having MCI (score &lt;26: N: 44: age: 81 ± 6.4) or non-MCI (score ≥26: n: 37: age: 77 ± 6). Groups were analyzed using a one-way ANOVA in SPSS to compare the severity of falls within the previous 12 months. There were no differences between groups for fall grade 1 (p =.22) or fall grade 2 (p =.45). There was a significant difference between groups for fall grade 3 (p =.04) and fall grade 4 (p =.05) with the MCI group having more of these falls compared to the non-MCI group. Older adults with MCI had a higher number of falls requiring medical attention than older adults without MCI. Although falls are a risk in all older adults, those with MCI may be at higher risk of more injurious falls than older adults without MCI.

Acute Inositol-Stabilized Arginine Silicate Improves Cognitive Outcomes in Healthy Adults

Inositol-stabilized arginine silicate (ASI) is an ergogenic aid that upregulates nitric oxide. Acute ASI supplementation improves working memory and processing speed in young adults but there is a lack of data examining other cognitive tasks. Therefore, the purpose of this study was to examine acute ASI effects on young healthy adults by assessing multiple cognitive domains. Nineteen young adults (20.9 ± 3.2 years) completed this randomized, double-blind, crossover study consuming ASI (1.5 g ASI + 12 g dextrose) and placebo (12 g dextrose). The participants completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and two digital cognitive assessments before consuming the supplement and then completed the same battery of tests 60 min post-supplementation. Repeated measures ANOVA demonstrated that ASI consumption significantly improved total RBANS and immediate memory scores compared to the placebo (p < 0.05). However, no significant differences were displayed between trials for other cognitive domains (p > 0.05). Acute ASI ingestion increased overall RBANS scores and immediate memory scores in young adults. More research is needed to examine the acute effects of ASI on other domains of cognition, in older populations, and its long-term effects on cognition.

Influence of Physical Activity Energy Expenditure on Functional Fitness Among Older Adults

Remaining physically active as one ages plays a critical role in maintaining health and improving functional capacity. Further, older adults can see additional health-related benefits by increasing intensity, duration, frequency, and/or levels of physical activity. However, there is limited research examining physical activity energy expenditure (PAEE) and measures of functional fitness. Therefore, the purpose was to examine differences between older adults with varying levels of PAEE on selected measures of functional fitness. A sample of 25 adults (age: 74.0±7.1 years) were recruited from an urban area and divided into two groups. PAEE was calculated using the total caloric expenditure per week for all exercise-related activities from a self-reported PA questionnaire. Group one expended less than 3,000 calories per week and group two spent more than 3,000 calories per week performing PA. The selected measures of functional fitness were a 4-m gait speed (GS), 30-s chair stand test (CS-30), 2-min step test (ST), and the 8-foot up and go test (GUG). Data were analyzed using a one-way ANOVA. There was a statistically significant difference between the groups on GS (F1, 24 = 9.29, p < .01) and CS-30 (F1, 24 = 4.37, p = .05). The results yielded a trend for the GUG (p =.06). However, there was not a difference between the groups on the ST (p = .11). These results suggest older adults expending more than 3,000 calories per week performing PA walk faster and have greater lower-body strength.

The Prediapause Stage of Aedes japonicus japonicus and the Evolution of Embryonic Diapause in Aedini

The genus Aedes is well known for its desiccation-resistant eggs, which frequently serve as an overwintering mechanism through diapause. Despite this, relatively little is known about the diapause and overwintering biology of most Aedes species including Aedes japonicus japonicus, an invasive mosquito in the United States. The importance of this mosquito in disease systems like La Crosse virus remain uncertain. Embryonic diapause is used by Ae. j. japonicus to survive temperate winters, and the persistence of this species in the Appalachian region is a result of overwintering, which has important implications for the transmission of this virus to humans. The objective of this study was to identify the prediapause stage, or the stage sensitive to environmental cues needed to induce diapause in this mosquito. By exposing each Ae. j. japonicus life stage independently to short-day photoperiods, we determined that the adult maternal life stage is the prediapause stage. Using the most recent phylogeny and prior literature on the prediapause stages in the genus Aedes, we were able to infer the evolutionary history of the prediapause stages of Aedes mosquitoes that overwinter or aestivate as eggs. This initial ancestral state reconstruction allowed us to hypothesize that Aedini mosquitoes that undergo obligate diapause may have evolved from those utilizing the embryonic prediapause stage, and that the ancestral prediapause state of Aedini appears to be maternally controlled.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Lack of phototoxicity potential with delafloxacin in healthy male and female subjects: comparison to lomefloxacin

AIMS

Delafloxacin is a fluoroquinolone antibiotic recently approved by the FDA for treatment of acute bacterial skin and skin structure infections (ABSSSI). Delafloxacin was assessed for phototoxicity potential compared with a known phototoxic fluoroquinolone.

METHODS

A Phase 1, investigator-blind, placebo/active-controlled, randomized, parallel-group study was conducted in 52 healthy male and female volunteers who received 200 or 400 mg of oral delafloxacin, 400 mg oral lomefloxacin or placebo once daily for 6 days. This study evaluated the photosensitizing potential and possible wavelength dependency of delafloxacin by comparing the response of the skin to ultraviolet A (UVA), ultraviolet B (UVB) and visible radiation prior to and during administration of delafloxacin, lomefloxacin as a positive control, or placebo. Adverse events were monitored throughout the study.

RESULTS

Forty-seven subjects completed six days of dosing, and no evidence of phototoxicity was seen with delafloxacin. Delafloxacin at 200 and 400 mg day-1 and placebo did not demonstrate differences in percent change from baseline in minimal erythema dose at all tested wavelengths (295-430 nm) by monochromator and solar simulator. Lomefloxacin, the positive control, had statistically significant differences (p < 0.05) at UVA wavelengths of 335 and 365 ± 30 nm 24 hours after radiation exposure (maximum response). The phototoxic index results were significantly higher for lomefloxacin at 335 nm and 365 nm compared to placebo and delafloxacin.

CONCLUSIONS

200 and 400 mg of delafloxacin administered for 6 days were well tolerated in healthy adult volunteers. Delafloxacin and placebo failed to demonstrate a phototoxic effect but lomefloxacin, the positive control, demonstrated moderate phototoxicity.

Morphological Differentiation of the Eggs of North American Container-Inhabiting Aedes Mosquitoes

Aedes aegypti , Ae. albopictus, Ae. japonicus japonicus, and Ae. triseriatus eggs are described with the aid of color images and images from scanning electron microscopy. All eggs were broadly cigar shaped with Ae. triseriatus and Ae. j japonicus eggs being dull or matte black, while Ae. albopictus and Ae. aegypti eggs were shiny jet black. Aedes triseriatus eggs were lighter in color and had a rougher appearance when compared to those of Ae. j. japonicus. Aedes albopictus and Ae. aegypti eggs can be differentiated by the distinct presence of micropylar collars in Ae. aegypti. Our results reduce the need to rear these mosquitoes, reducing labor and time while providing an accurate identification of the vector mosquitoes.

Parameters of gait among community-dwelling older adults

BACKGROUND

Functional fitness is the ability of an older adult to perform activities of daily living. Stair-climb power is a well-documented marker of functional fitness among older adults. Gait velocity and parameters of gait are related to functional fitness but have been understudied to date.

PURPOSE

The purpose of this observational study was to determine differences in parameters of gait between high- and low-functioning older adults.

METHODS

Twenty high-functioning older adults, mean age (SD)=71.6 (5.6), volunteered for the cross-sectional observational study. Functional fitness was determined by a stair-climb performance test. Parameters of gait included velocity, step length, swing and stance phase, double support time, ground reaction forces, impulse, and propulsion during habitual walking. Analysis of variance was performed to determine differences in the dependent variables between groups.

RESULTS

Individuals with high levels of functional fitness walked 13.1% faster than the lower-functioning group (P=.01). No significant differences (P>.05) were detected for any other measure; however, all gait parameters were more favorable in the higher-functioning group.

CONCLUSION

Functional fitness is imperative for older adults as declines could hinder mobility. Thus, earlier detection of declines in gait parameters may reduce the risk of falling. The results suggest that gait velocity was slower among older adults with lower levels of functional fitness.

Developing a measure of muscular power during a functional task for older adults

Background

Muscular power is an important aspect of many activities of daily living and declines at a faster rate than other fitness parameters (i.e. muscular strength and endurance). Assessing muscular power among older adults is problematic as many of the popular tests are contraindicated among older adults and field tests to assess muscular power among older adults have not been validated among older adults. Therefore, the aim of the present investigation was to determine the validity and reliability of a field test to measure of muscular power during a functional movement among community-dwelling older adults (≥ 65 years).

Methods

Twenty community-dwelling older adults (71.6 ± 5.6) volunteered to have their muscular power assessed during repeated sit-to-stand (STS) tasks. Each participant performed 10 STS with 60 s rest between trials. Muscular power was assessed during this functional movement with the Tendo as well as change in center of mass (COM) over time using cinematography.

Results

Relative power measured by Tendo was 5.34 ± 1.67 W/kg and values for COM were 5.39 ± 1.73 W/kg (p = .86). Cronbach’s alpha for Tendo muscular power for repeated trials was .98.

Conclusions

Tendo is a simple field method of determining muscular power among older adults and validation is essential. Results from this investigation support Tendo as a valid and reliable method for determining muscular power during a STS task among older adults. Clinicians may use this tool to evaluate and assess progress in older adults’ power and physical functioning.

Prophylactic ankle taping: influence on treadmill-running kinematics and running economy

Prophylactic ankle taping (PAT) is commonly used in sport. Prophylactic ankle taping may restrict ankle motion, which would affect the kinetic chain and alter gait. The purpose of this study was to examine the effects of PAT on lower extremity (LE) kinematics and running economy during treadmill running. Twelve recreational runners (9 women, 3 men; M ± SD age = 31.33 ± 8.04 years, height = 1.67 ± 0.81 m, mass = 61.84 ± 9.38 kg) completed two 20-minute running sessions (PAT and no tape: control [CON]) at a self-selected pace. Before each run, reflective markers were placed along the right side of the body. Sagittal plane kinematic data (60 Hz) were captured 4 times, and expired gases were measured for 2-minute after each video capture during both trials. Stride frequency, stride length, LE kinematic variables at initial contact and end contact (EC) were calculated. Cardiorespiratory variables and heart rate were also measured. Running economy was normalized to oxygen uptake per unit body mass per kilometer (milliliter per kilogram per kilometer) as running speeds varied. At EC, the PAT hip angle significantly decreased (p = 0.01) by 3.82°, whereas CON decreased by 0.85°. The range of motion tended to decrease over the 20-minute run (p = 0.08). Heart rate significantly increased over time (6.7%) but was not different between conditions. Prophylactic ankle taping did not significantly affect the physiological measures associated with the metabolic cost of treadmill running or the other kinematic variables. These findings suggest that the hip angle continued to decrease during the PAT condition at push-off in recreational runners without impacting the metabolic cost of transport.

Mechanical and physiological examination of barefoot and shod conditions in female runners

Barefoot running and running using minimalist footwear have become increasingly popular in recent years. Footwear choice may affect running mechanics and the metabolic cost of running. To investigate these factors, 8 well-trained, female distance runners (mean age=20.1±1.4 years) were recruited to participate in the study. Following orientation to testing procedures, subjects completed 3 running economy tests on separate days. Treatment order (barefoot, minimalist footwear and running shoe) was counter-balanced. Each testing session consisted of a 5-min warm-up at 2.24 m · s(-1), followed by the 7-min RE test at 3.13 m · s(-1). Biomechanical data were collected at the 3-min mark for 10 s, and expired gases were collected from minutes 5-7. One-way repeated measures ANOVA revealed a statistically significant difference for running economy (p=0.04), expressed as relative oxygen uptake per km in the barefoot condition (running shoe: 204.51±2.84; minimalist footwear: 198.21±3.04; barefoot: 193.26±3.62 ml · kg(-1)· km(-1)) vs. running shoe. The other physiological and biomechanical variables were not statistically significant (p>0.05). However, moderate to large effect sizes suggested there were biomechanical changes that ensured between conditions. It should be further evaluated whether these mechanical adjustments and the running economy trend would translate into improved distance race performance while running barefoot or with minimalist footwear.

The effects of a downhill running bout on running economy

This study investigated whether downhill (DH) running (10-min @ 214.4 m·min(-1) and -10% grade) would elicit acute and delayed effects on running economy (RE) upon completion of DH running (RE2) and daily over 72 h (RE3, RE4, RE5). Fifteen runners (8 female, 7 male) completed the protocol. RE was measured during level running performed at 70% VO2peak. A baseline RE test (RE1) was used for comparison. Muscle soreness was significantly elevated at RE3 and RE4 vs. RE1. Oxygen uptake was significantly elevated at RE2 relative to RE3, RE4 and RE5 but was not different from RE1. Heart rate was similarly elevated at RE2. Measures of ankle, knee and hip joint angles at heel strike and toe off were not affected at any time-point in a subset of subjects (N = 6). A short DH running bout did not elicit significant delayed adverse effects on oxygen uptake or gait parameters relative to baseline.

Torsional electromechanical systems based on carbon nanotubes

Carbon nanotubes (CNTs) are among the most highly studied nanomaterials due to their unique (and intertwined) mechanical and electrical properties. Recent advances in fabrication have allowed devices to be fabricated that are capable of applying a twisting force to individual CNTs while measuring mechanical and electrical response. Here, we review major results from this emerging field of study, revealing new properties of the material itself and opening possibilities for advances in future devices.

The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes

The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes. The aim of this investigation was to compare the acute effects of parachute-resisted (PR) sprinting on selected kinematic variables. Twelve collegiate sprinters (mean age 19.58 ± 1.44 years, mass 69.32 ± 14.38 kg, height 1.71 ± 9.86 m) ran a 40-yd dash under 2 conditions: PR sprint and sprint without a parachute (NC) that were recorded on a video computer system (60 Hz). Sagittal plane kinematics of the right side of the body was digitized to calculate joint angles at initial ground contact (IGC) and end ground contact (EGC), ground contact (GC) time, stride rate (SR), stride length (SL), and the times of the 40-yd dashes. The NC 40-yd dash time was significantly faster than the PR trial (p < 0.05). The shoulder angle at EGC significantly increased from 34.10 to 42.10° during the PR trial (p < 0.05). There were no significant differences in GC time, SR, SL, or the other joint angles between the 2 trials (p > 0.05). This study suggests that PR sprinting does not acutely affect GC time, SR, SL and upper extremity or lower extremity joint angles during weight acceptance (IGC) in collegiate sprinters. However, PR sprinting increased shoulder flexion by 23.5% at push-off and decreased speed by 4.4%. While sprinting with the parachute, the athlete's movement patterns resembled their mechanics during the unloaded condition. This indicates the external load caused by PR did not substantially overload the runner, and only caused a minor change in the shoulder during push-off. This sports-specific training apparatus may provide coaches with another method for training athletes in a sports-specific manner without causing acute changes to running mechanics.

Electron beam induced structural transformations of SWNTs and DWNTs grown on Si3N4/Si substrates

Electron beam induced structural transformations are investigated in single-wall carbon nanotubes (SWNTs), double-wall carbon nanotubes (DWNTs) and crossed nanotube junctions. The nanotubes studied here are synthesized by the chemical vapor deposition method. The response of the nanotubes to an electron beam is found to be influenced by the presence of coatings of amorphous carbon, graphene fragments and structural defects on the tube surface. The dependence of structural modifications on electron beam irradiation dose is measured. While nanotubes with amorphous carbon, graphene fragment coverage and/or defects undergo rapid transformation leading to structure disintegration, those without such coverage or defects are more resistant to beam damage. In addition, it is shown that the amorphous carbon coverage on the double-wall nanotubes can be transformed into graphene layers during electron beam irradiation of coated nanotubes. Finally, the relative stability of nanotube side-wall and end-walls are investigated through sub-threshold energy and above threshold energy irradiation of a model system, C60-filled nanotubes (Peapods). The data indicates that electron beams could be used to join nanotubes end-to-end without damaging the side-walls.

Controlled switching of optical emission energies in semiconducting single-walled carbon nanotubes

We present scanning photoluminescence (PL) microscopy of freely suspended single-walled carbon nanotubes grown by chemically assisted vapor deposition (CVD) across micron-sized open apertures. Scans of the PL emission versus excitation position show unusual "holes"having subwavelength spatial features associated with abrupt blue shifts of the emission energy. By varying the excitation polarization, energy, intensity, and position, we demonstrate that optical switching in some nanotubes is controllable in a highly nonlinear manner by adjusting the nonequilibrium carrier density in the nanotube. Technologically important attributes include large spectral contrast between on/off states at room temperature, a dramatic response to small changes in light intensity near threshold, and the possibility that electrical charge injection could also be used to control emission energies.

A fast, convenient and rugged procedure for characterizing the selectivity of alkyl-silica columns

Previous work has shown that the selectivity of reversed-phase columns for HPLC can be described by means of five column parameters: H (hydrophobicity), S* (steric resistance), A (hydrogen-bond acidity), B (hydrogen-bond basicity) and C (cation-exchange capacity). Values of H, S*, etc. can be determined by carrying out retention measurements for 18 test solutes under standardized conditions. The reproducibility of the latter procedure has been evaluated by comparison testing in four different laboratories and found acceptable. An alternative 10-solute test procedure which is more reproducible and convenient (but somewhat less accurate), requires only 2-3 h per column.

Low proliferative rate of invasive node-negative breast cancer predicts for a favorable outcome: a prospective evaluation of 669 patients

This study was designed to compare outcome in terms of disease-free survival (DFS) in women with histologically negative axillary lymph nodes and documented low proliferative rate cancer to other well-defined prognostic factors including type of adjuvant treatment. Between 1988 and 1998, we studied 669 patients with invasive node-negative breast cancer up to 5 cm in size and low proliferative rate measured by flow cytometry to determine S-phase fraction (SPF) or by histochemistry (Ki67/MIB1). At a median follow-up of 53 months, 5-year DFS for the entire group was 94% and did not differ significantly by type of systemic adjuvant treatment: none (133 patients, 95% DFS), tamoxifen (441 patients, 94% DFS), or chemotherapy with doxorubicin and cyclophosphamide (95 patients, 92% DFS). In a multivariate prognostic factor analysis, only tumor size was significant; 5-year DFS was 96% for T1N0 cancer versus 89% for T2N0 cancer (P = 0.01). We have prospectively confirmed that a low rate of proliferation as measured by SPF or MIB1 determination confers an excellent prognosis in invasive node-negative breast cancer up to 5 cm in size, regardless of adjuvant treatment.