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1.
Stat Med ; 39(26): 3823-3839, 2020 11 20.
Article in English | MEDLINE | ID: mdl-33048360

ABSTRACT

Although all clinical trials are designed and monitored using more than one endpoint, methods are needed to assure that decision criteria are chosen to reflect the clinically relevant tradeoffs that assure the trial's scientific integrity. This article presents a framework for the design and monitoring clinical trials in a bivariate outcome space. The framework uses a rectangular hyperbola to define a bivariate null curve that divides outcome space into regions of benefit and lack of benefit. The curve is shown to be a flexible mapping of bivariate space that allows a continuous tradeoff between the two endpoints in a manner that captures many previous bivariate designs. The curve is extended to a distance function in bivariate space that allows different decisions in each of the four quadrants that comprise bivariate space. The distance function forms a statistic ( δ ); the distribution of its estimate is derived and used as a basis for trial design and group sequential monitoring plans in bivariate space. A recursive form of the bivariate group sequential density is used to evaluate and control operating characteristics for the proposed design. The bivariate designs are shown to meet or exceed the usual standards for size and power. The proposed design is illustrated in the ongoing NHLBI-sponsored Kids-DOTT multinational randomized controlled trial comparing shortened versus conventional anticoagulation for the treatment of venous thromboembolism in patients less than 21 years of age. The proposed methods are broadly applicable to a wide range of clinical settings and trial designs.


Subject(s)
Clinical Trials as Topic , Humans , Research Design
2.
Ann Surg Oncol ; 25(3): 768-775, 2018 Mar.
Article in English | MEDLINE | ID: mdl-28887726

ABSTRACT

BACKGROUND: Desmoid fibromatosis is a fibroblastic neoplasm driven by aberrations within the WNT pathway, exhibiting mutations in ß-catenin or APC. We review the long-term follow-up of patients in a phase I study treated with an oral gamma secretase inhibitor, PF-03084014. METHODS: PF-03084014 was administered orally at doses ranging from 20 to 330 mg twice daily. Tumor assessments were performed using computed tomography/magnetic resonance imaging (CT/MRI) within 4 weeks of study entry, and every other cycle through cycle 9. After cycle 9, patients were evaluated as clinically indicated. RESULTS: Seven patients with desmoid fibromatosis were treated between December 2009 and December 2016 at the University of Colorado. Five patients (71.4%, 95% confidence interval [CI] 29.0-96.3%) achieved a partial response (PR), with a mean time to achieving response of 11.9 months (95% CI 2.5-21.4 months). All patients who achieved a PR continue to maintain responses between 47.9 and 73+ months. Four patients stopped treatment yet remain free of progression between 11 and 53+ months. One patient had PFS of 42+ months, with a 17% decrease in the target lesion. A biopsy performed at the end of the study showed decreased tumoral cellularity compared with previous biopsies. Effective treatment doses ranged from 80 to 330 mg administered orally twice daily. CONCLUSIONS: PF-03084014 was effective in treating desmoid tumors, with an objective response rate of 71.4% (95% CI 29.0-96.3%) in this small cohort of patients. PF-03084014 exhibits promising activity, even at relatively low doses (80 mg twice daily), with high tolerability leading to prolonged disease control even after therapy discontinuation.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Fibromatosis, Aggressive/drug therapy , Tetrahydronaphthalenes/administration & dosage , Valine/analogs & derivatives , Administration, Oral , Fibromatosis, Aggressive/enzymology , Fibromatosis, Aggressive/pathology , Follow-Up Studies , Humans , Prognosis , Retrospective Studies , Time Factors , Valine/administration & dosage
3.
Int J Cancer ; 138(1): 195-205, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26152787

ABSTRACT

Dysregulation of the Notch1 receptor has been shown to facilitate the development and progression of colorectal cancer (CRC) and has been identified as an independent predictor of disease progression and worse survival. Although mutations in the NOTCH1 receptor have not been described in CRC, we have previously discovered a NOTCH1 gene copy number gain in a portion of CRC tumor samples. Here, we demonstrated that a NOTCH1 gene copy number gain is significantly associated with worse survival and a high percentage of gene duplication in a cohort of patients with advanced CRC. In our CRC patient-derived tumor xenograft (PDTX) model, tumors harboring a NOTCH1 gain exhibited significant elevation of the Notch1 receptor, JAG1 ligand and cleaved Notch1 activity. In addition, a significant association was identified between a gain in NOTCH1 gene copy number and sensitivity to a Notch1-targeting antibody. These findings suggest that patients with metastatic CRC that harbor a gain in NOTCH1 gene copy number have worse survival and that targeting this patient population with a Notch1 antibody may yield improved outcomes.


Subject(s)
Colorectal Neoplasms/genetics , Colorectal Neoplasms/mortality , DNA Copy Number Variations , Gene Dosage , Receptor, Notch1/genetics , Animals , Antibodies, Monoclonal/pharmacology , Apoptosis/drug effects , Apoptosis/genetics , Biomarkers, Tumor , Calcium-Binding Proteins/metabolism , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Disease Models, Animal , Drug Resistance, Neoplasm/genetics , Female , Gene Duplication , Humans , Intercellular Signaling Peptides and Proteins/metabolism , Jagged-1 Protein , Male , Membrane Proteins/metabolism , Mice , Neoplasm Metastasis , Prognosis , Receptor, Notch1/antagonists & inhibitors , Receptor, Notch1/metabolism , Serrate-Jagged Proteins , Signal Transduction/drug effects , Xenograft Model Antitumor Assays
4.
Int J Cancer ; 136(8): 1967-75, 2015 Apr 15.
Article in English | MEDLINE | ID: mdl-25242168

ABSTRACT

Antiangiogenic therapy is commonly used for the treatment of colorectal cancer (CRC). Although patients derive some clinical benefit, treatment resistance inevitably occurs. The MET signaling pathway has been proposed to be a major contributor of resistance to antiangiogenic therapy. MET is upregulated in response to vascular endothelial growth factor pathway inhibition and plays an essential role in tumorigenesis and progression of tumors. In this study, we set out to determine the efficacy of cabozantinib in a preclinical CRC patient-derived tumor xenograft model. We demonstrate potent inhibitory effects on tumor growth in 80% of tumors treated. The greatest antitumor effects were observed in tumors that possess a mutation in the PIK3CA gene. The underlying antitumor mechanisms of cabozantinib consisted of inhibition of angiogenesis and Akt activation and significantly decreased expression of genes involved in the PI3K pathway. These findings support further evaluation of cabozantinib in patients with CRC. PIK3CA mutation as a predictive biomarker of sensitivity is intriguing and warrants further elucidation. A clinical trial of cabozantinib in refractory metastatic CRC is being activated.


Subject(s)
Anilides/pharmacology , Antineoplastic Agents/pharmacology , Colorectal Neoplasms/drug therapy , Proto-Oncogene Proteins c-met/antagonists & inhibitors , Pyridines/pharmacology , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Adult , Aged , Angiogenesis Inhibitors/pharmacology , Animals , Biomarkers, Tumor/metabolism , Cell Line, Tumor , Class I Phosphatidylinositol 3-Kinases , Colorectal Neoplasms/metabolism , Female , HCT116 Cells , Humans , Mice , Mice, Nude , Middle Aged , Neovascularization, Pathologic/drug therapy , Neovascularization, Pathologic/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-met/metabolism , Signal Transduction/drug effects , Vascular Endothelial Growth Factor Receptor-2/metabolism , Xenograft Model Antitumor Assays/methods
6.
Invest New Drugs ; 32(4): 739-45, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24668033

ABSTRACT

PURPOSE: The notch pathway is overexpressed in pancreatic adenocarcinoma. RO4929097, an oral inhibitor of the γ-secretase enzyme has been safely given as a single agent in patients with advanced solid tumors. We aimed to evaluate the efficacy of RO4929097 in patients with pancreatic adenocarcinoma (PDA). METHODS: A two-stage, single-arm Phase II trial was conducted in patients with previously treated metastatic PDA. RO4929097 was administered at a dose of 20 mg daily on days 1-3, 8-10 and 15-17 of 21-day cycles. The primary endpoint was survival at 6 months. Secondary endpoints included overall survival (OS), response rate, toxicities, pharmacokinetic and pharmacodynamic analyses. RESULTS: Eighteen patients were recruited, 17 in the first stage and one in the 2nd stage. It was decided to stop further enrollment after RO4929097 was discontinued by the sponsor and was no longer a development candidate. Three (25 %) of 12 evaluable patients achieved stable disease. The 6-month survival rate was 27.8 % (95 % CI 9.7-53.5). The median OS was 4.1 months (95 % CI 2.7-5.8 months) and median progression-free survival was 1.5 months (95 % CI 1.3-1.6 months). Pharmacokinetic properties of RO4929097 in patients (n = 5) with PDA was similar to that previously reported in other patient populations. There was a trend towards a decrease in HeyL (p = 0.08) gene expression in three patients following study drug administration. CONCLUSIONS: RO4929097 was well-tolerated in patients with previously treated PDA. Development of RO4929097 has been discontinued, but development of other notch-targeting agents in pancreatic cancer is continuing.


Subject(s)
Adenocarcinoma/drug therapy , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Antineoplastic Agents/therapeutic use , Benzazepines/therapeutic use , Enzyme Inhibitors/therapeutic use , Pancreatic Neoplasms/drug therapy , Adenocarcinoma/metabolism , Aged , Aged, 80 and over , Amyloid Precursor Protein Secretases/metabolism , Antineoplastic Agents/pharmacokinetics , Benzazepines/pharmacokinetics , Disease-Free Survival , Female , Humans , Male , Middle Aged , Pancreatic Neoplasms/metabolism , Survival Rate , Pancreatic Neoplasms
7.
Ann Intern Med ; 159(9): 592-600, 2013 Nov 05.
Article in English | MEDLINE | ID: mdl-24189594

ABSTRACT

BACKGROUND: Among former prisoners, a high rate of death has been documented in the early postrelease period, particularly from drug-related causes. Little is known about risk factors and trends in postrelease mortality in the past decade, especially given general population increases in overdose deaths from pharmaceutical opioids. OBJECTIVE: To determine postrelease mortality between 1999 and 2009; cause-specific mortality rates; and whether sex, calendar year, and custody factors were risk factors for all-cause, overdose, and opioid-related deaths. DESIGN: Cohort study. SETTING: Prison system of the Washington State Department of Corrections. PARTICIPANTS: 76 208 persons released from prison. MEASUREMENTS: Identities were linked probabilistically to the National Death Index to identify deaths and causes of death, and mortality rates were calculated. Cox proportional hazards regression estimated the effect of age, sex, race or ethnicity, whether the incarceration resulted from a violation of terms of the person's community supervision, length of incarceration, release type, and calendar year on the hazard ratio (HR) for death. RESULTS: The all-cause mortality rate was 737 per 100 000 person-years (95% CI, 708 to 766) (n = 2462 deaths). Opioids were involved in 14.8% of all deaths. Overdose was the leading cause of death (167 per 100 000 person-years [CI, 153 to 181]), and overdose deaths in former prisoners accounted for 8.3% of the overdose deaths among persons aged 15 to 84 years in Washington from 2000 to 2009. Women were at increased risk for overdose (HR, 1.38 [CI, 1.12 to 1.69]) and opioid-related deaths (HR, 1.39 [CI, 1.09 to 1.79]). LIMITATION: The study was done in only 1 state. CONCLUSION: Innovation is needed to reduce the risk for overdose among former prisoners. PRIMARY FUNDING SOURCE: National Institute on Drug Abuse and the Robert Wood Johnson Foundation.


Subject(s)
Cause of Death , Drug Overdose/epidemiology , Opioid-Related Disorders/epidemiology , Prisoners/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Prisoners/psychology , Risk Factors , Sex Factors , Time Factors , Vulnerable Populations/statistics & numerical data , Washington/epidemiology , Young Adult
8.
Clin Cancer Res ; 30(17): 3768-3778, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-38869830

ABSTRACT

PURPOSE: In this single-institution phase II investigator-initiated study, we assessed the ability of MAPK and VEGF pathway blockade to overcome resistance to immunotherapy in microsatellite-stable metastatic colorectal cancer (MSS mCRC). PATIENTS AND METHODS: Patients with MSS, BRAF wild-type mCRC who progressed on ≥2 prior lines of therapy received pembrolizumab, binimetinib, and bevacizumab until disease progression or unacceptable toxicity. After a safety run-in, patients were randomized to a 7-day run-in of binimetinib or simultaneous initiation of all study drugs, to explore whether MEK inhibition may increase tumor immunogenicity. The primary endpoint was objective response rate (ORR) in all patients combined (by Response Evaluation Criteria in Solid Tumors v1.1). RESULTS: Fifty patients received study drug treatment; 54% were male with a median age of 55 years (range, 31-79). The primary endpoint, ORR, was 12.0% [95% confidence interval (CI) 4.5%-24.3%], which was not statistically different than the historical control data of 5% (P = 0.038, exceeding prespecified threshold of 0.025). The disease control rate was 70.0% (95% CI, 55.4%-82.1%), the median progression-free survival 5.9 months (95% CI, 4.2-8.7 months), and the median overall survival 9.3 months (95% CI, 6.7-12.2 months). No difference in efficacy was observed between the randomized cohorts. Grade 3 and 4 adverse events were observed in 56% and 8% of patients, respectively; the most common were rash (12%) and increased aspartate aminotransferase (12%). CONCLUSIONS: Pembrolizumab, binimetinib, and bevacizumab failed to meet its primary endpoint of higher ORR compared with historical control data, demonstrated a high disease control rate, and demonstrated acceptable tolerability in refractory MSS mCRC.


Subject(s)
Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols , Benzimidazoles , Bevacizumab , Colorectal Neoplasms , Humans , Male , Female , Middle Aged , Bevacizumab/administration & dosage , Bevacizumab/therapeutic use , Bevacizumab/adverse effects , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Colorectal Neoplasms/mortality , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Benzimidazoles/administration & dosage , Benzimidazoles/therapeutic use , Benzimidazoles/adverse effects , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Drug Resistance, Neoplasm/genetics , Microsatellite Repeats , Treatment Outcome
9.
Animal Model Exp Med ; 5(3): 248-257, 2022 09.
Article in English | MEDLINE | ID: mdl-35699330

ABSTRACT

The consistency of reporting results for patient-derived xenograft (PDX) studies is an area of concern. The PDX method commonly starts by implanting a derivative of a human tumor into a mouse, then comparing the tumor growth under different treatment conditions. Currently, a wide array of statistical methods (e.g., t-test, regression, chi-squared test) are used to analyze these data, which ultimately depend on the outcome chosen (e.g., tumor volume, relative growth, categorical growth). In this simulation study, we provide empirical evidence for the outcome selection process by comparing the performance of both commonly used outcomes and novel variations of common outcomes used in PDX studies. Data were simulated to mimic tumor growth under multiple scenarios, then each outcome of interest was evaluated for 10 000 iterations. Comparisons between different outcomes were made with respect to average bias, variance, type-1 error, and power. A total of 18 continuous, categorical, and time-to-event outcomes were evaluated, with ultimately 2 outcomes outperforming the others: final tumor volume and change in tumor volume from baseline. Notably, the novel variations of the tumor growth inhibition index (TGII)-a commonly used outcome in PDX studies-was found to perform poorly in several scenarios with inflated type-1 error rates and a relatively large bias. Finally, all outcomes of interest were applied to a real-world dataset.


Subject(s)
Neoplasms , Animals , Disease Models, Animal , Humans , Mice , Neoplasms/therapy , Tumor Burden
10.
Cancer Res Commun ; 2(10): 1188-1196, 2022 10.
Article in English | MEDLINE | ID: mdl-36969746

ABSTRACT

Purpose: Multi-tyrosine kinase inhibitors (TKI) have shown clinical activity in patients with metastatic colorectal cancer. Cabozantinib, a multi-TKI, exhibited potent antitumor activity superior to regorafenib in preclinical colorectal cancer patient-derived tumor xenograft models. This phase II study aimed to investigate cabozantinib, a multi-TKI, in patients with refractory, metastatic colorectal cancer (mCRC). Experimental Design: A nonrandomized, two-stage, phase II clinical trial evaluating 12-week progression-free survival (PFS) was conducted in eight cancer centers across the United States between May 2018 and July 2020. Results: A total of 44 patients were enrolled between May 2018 and May 2019, 40 of which were response evaluable. Of the total 769 reported adverse events (AE), 93 (12%) were ≥ grade 3. Five grade 5 AEs were reported of which four were unrelated to study drug and one was reported as possibly related due to bowel perforation. Eighteen patients (45%) achieved 12-week PFS with stable disease or better (confidence interval, 0.29-0.62; P < 0.001). One patient (3%) had a partial response, and 27 other patients achieved stable disease as best response per RECISTv1.1. Median PFS was 3.0 months, and median overall survival was 8.3 months. Of the 18 patients who achieved 12-week PFS, 12 had left-sided primary tumors, 11 were RAS wild type, 11 were PIK3CA wild type, and 6 had previous regorafenib therapy. The 12-week PFS rate was higher in RAS wild-type tumors compared with RAS mutant tumors (0.61 vs. 0.32; P = 0.11). Conclusions: This phase II study demonstrated clinical activity of cabozantinib in heavily pretreated, patients with refractory mCRC, and supports further investigation. Significance: Targeting angiogenesis through VEGF axis blockade provides incremental survival benefit in patients with mCRC. The hepatocyte growth factor/MET signal transduction pathway has been observed as a mechanism for acquired resistance. Dual inhibition of VEGF plus MET is an attractive therapeutic strategy. This phase II trial demonstrated clinical activity with cabozantinib, a multi-TKI targeting VEGFR2 and MET, in patients with refractory, mCRC.


Subject(s)
Colorectal Neoplasms , Vascular Endothelial Growth Factor A , Humans , Colorectal Neoplasms/drug therapy , Pyridines/adverse effects , Vascular Endothelial Growth Factor A/therapeutic use , Prospective Studies
11.
Front Oncol ; 12: 877635, 2022.
Article in English | MEDLINE | ID: mdl-36419897

ABSTRACT

Immune checkpoint inhibitors have been found to be effective in metastatic MSI-high colorectal cancers (CRC), however, have no efficacy in microsatellite stable (MSS) cancers, which comprise the majority of mCRC cases. Cabozantinib is a small molecule multi-tyrosine kinase inhibitor that is FDA approved in advanced renal cell, medullary thyroid, and hepatocellular carcinoma. Using Human Immune System (HIS) mice, we tested the ability of cabozantinib to prime MSS-CRC tumors to enhance the potency of immune checkpoint inhibitor nivolumab. In four independent experiments, we implanted distinct MSS-CRC patient-derived xenografts (PDXs) into the flanks of humanized BALB/c-Rag2nullIl2rγnullSirpαNOD (BRGS) mice that had been engrafted with human hematopoietic stem cells at birth. For each PDX, HIS-mice cohorts were treated with vehicle, nivolumab, cabozantinib, or the combination. In three out of the four models, the combination had a lower tumor growth rate compared to vehicle or nivolumab-treated groups. Furthermore, interrogation of the HIS in immune organs and tumors by flow cytometry revealed increased Granzyme B+, TNFα+ and IFNγ+ CD4+ T cells among the human tumor infiltrating leukocytes (TIL) that correlated with reduced tumor growth in the combination-treated HIS-mice. Notably, slower growth correlated with increased expression of the CD4+ T cell ligand, HLA-DR, on the tumor cells themselves. Finally, the cabozantinib/nivolumab combination was tested in comparison to cobimetinib/atezolizumab. Although both combinations showed tumor growth inhibition, cabozantinib/nivolumab had enhanced cytotoxic IFNγ and TNFα+ T cells. This pre-clinical in vivo data warrants testing the combination in clinical trials for patients with MSS-CRC.

12.
J Gen Intern Med ; 26(6): 575-81, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21203859

ABSTRACT

INTRODUCTION: Little is known about how the development of a new chronic health condition affects management of existing chronic conditions over time. New conditions might worsen management of existing conditions because of competing demands or improve management of existing conditions because of increased engagement with heath care. We assessed the effect of incident stage 0, 1, 2 or 3 breast, colon or prostate cancer; incident depression; or an exacerbation of chronic pulmonary disease on control of type 2 diabetes (DM2). METHODS: We conducted a longitudinal, historical cohort study within an integrated, not-for-profit HMO. Of a cohort of persons with diagnoses of DM2 between 1998 and 2008, 582, 2,959 and 2,332 developed incident cancer, depression or pulmonary disease exacerbation, respectively. We assessed change in hemoglobin A1c (A1c) as a function of the occurrence of the incident comorbidity in each subcohort for a period of 1 to 5 years after the occurrence of the incident comorbidity. Secondary outcomes were systolic blood pressure (SBP) and low density lipoprotein (LDL) levels. Multivariate linear regression was adjusted for demographics, morbidity level, BMI, numbers of primary and specialty visits, and continuity of primary care. Latent class analyses assessed post-comorbidity outcome trajectories. All time-varying covariates were calculated for a 24-month pre-diagnosis period and 0 to 24- and 24 to 60-month post-diagnosis periods. RESULTS: For each condition, A1c did not change significantly from before to after the incident comorbidity. This was confirmed by latent class growth curve analyses that grouped patients by their A1c trajectories. SBP and LDL were also not significantly changed pre- and post-diagnosis of the incident comorbidities. DISCUSSION: Although incident comorbidities inevitably will affect patients' and clinicians' care priorities, we did not observe changes in these particular outcomes. Additional investigation of interactions between diseases will inform changes in care that benefit complex patient populations.


Subject(s)
Asthma/complications , Depressive Disorder/complications , Diabetes Mellitus, Type 2/complications , Disease Progression , Neoplasms/complications , Pulmonary Disease, Chronic Obstructive/complications , Aged , Asthma/epidemiology , Asthma/therapy , Cohort Studies , Comorbidity , Depressive Disorder/epidemiology , Depressive Disorder/therapy , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/therapy , Female , Humans , Incidence , Longitudinal Studies , Male , Middle Aged , Neoplasms/epidemiology , Neoplasms/therapy , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Disease, Chronic Obstructive/therapy
13.
PM R ; 13(5): 453-460, 2021 05.
Article in English | MEDLINE | ID: mdl-32926546

ABSTRACT

BACKGROUND: Interventions targeting psychosocial factors may improve rehabilitation outcomes for prosthesis users after lower-limb amputation (LLA), but there is a need to identify targeted factors for minimizing disability. OBJECTIVE: To identify psychosocial factors related to disability for prosthesis users after LLA in middle age or later. DESIGN: Cross-sectional study. SETTING: General community. PARTICIPANTS: Participants with LLA (N = 122) were included in this cross-sectional study if their most recent LLA was at least 1 year prior, they were ambulating independently with a prosthesis, and they were between 45 and 88 years old. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Disability, the primary outcome, was measured using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS). Candidate psychosocial variables included self-efficacy, social support, and motivation, measured using the Self-Efficacy of Managing Chronic Disease questionnaire (SEMCD), Multidimensional Scale of Perceived Social Support questionnaire (MSPSS), and modified contemplation ladder (mCL), respectively. The hypothesis was that greater self-efficacy, social support, and motivation would be associated with lower disability when controlling for covariates. RESULTS: The covariate model, including etiology, age, sex, U.S. military veteran status, LLA characteristics, time since LLA, medical complexity, and perceived functional capacity, explained 66.1% of disability variability (WHODAS 2.0). Backward elimination of candidate psychosocial variables stopped after removal of motivation (P = .10), with self-efficacy (P < .001) and social support (P = .002) variables remaining in the final model. The final model fit was statistically improved (P < .001) and explained an additional 6.1% of disability variability when compared to the covariate model. CONCLUSIONS: Greater self-efficacy and social support are related to lower disability after LLA. Findings suggest there may be a role for interventions targeting increased physical function, self-efficacy, and social support for ambulatory prosthesis users after LLA in middle age or later, especially when complicated by multiple chronic conditions.


Subject(s)
Artificial Limbs , Self Efficacy , Aged , Aged, 80 and over , Amputation, Surgical , Cross-Sectional Studies , Humans , Lower Extremity , Middle Aged , Social Support
14.
Bone ; 153: 116108, 2021 12.
Article in English | MEDLINE | ID: mdl-34252605

ABSTRACT

BACKGROUND: Endurance exercise can cause a decrease in serum ionized calcium (iCa) and increases in parathyroid hormone (PTH) and bone resorption, reflected by serum carboxy-terminal collagen crosslinks (CTX). We developed a calcium clamp to prevent the decrease in iCa during exercise, which attenuated increases in PTH and CTX during vigorous cycling in young men. The goal was to determine whether this occurs in older adults during brisk walking. METHODS: Twelve older adults (6 men, 6 women) performed two identical 60-min treadmill walking bouts with Ca gluconate or half-normal saline infusion. Blood sampling for iCa, total calcium (tCa), phosphate (P), PTH, and CTX, occurred before, during, and for 4 h after exercise. RESULTS: iCa decreased during exercise with the saline infusion (p = 0.04) and this provoked increases in PTH and CTX (both p < 0.01). The Ca clamp prevented the decrease in serum iCa during exercise and attenuated the PTH and CTX responses. CONCLUSIONS: Preventing the exercise-induced decrease in iCa markedly attenuated the increases in PTH and CTX. The cause of the decrease in iCa during exercise remains unclear, but the increases in PTH and CTX are likely counter-regulatory responses to defend serum iCa. This contention is supported by previous observations that the disruption of Ca homeostasis during exercise occurs regardless of training status. It will be important to establish whether this acute catabolic effect of exercise diminishes the potential chronic anabolic effects of exercise on bone.


Subject(s)
Bone Resorption , Calcium , Aged , Bone Resorption/prevention & control , Collagen Type I , Female , Humans , Male , Parathyroid Hormone , Peptides , Walking
15.
Front Immunol ; 12: 607282, 2021.
Article in English | MEDLINE | ID: mdl-33854497

ABSTRACT

Over the past decade, immunotherapies have revolutionized the treatment of cancer. Although the success of immunotherapy is remarkable, it is still limited to a subset of patients. More than 1500 clinical trials are currently ongoing with a goal of improving the efficacy of immunotherapy through co-administration of other agents. Preclinical, small-animal models are strongly desired to increase the pace of scientific discovery, while reducing the cost of combination drug testing in humans. Human immune system (HIS) mice are highly immune-deficient mouse recipients rtpeconstituted with human hematopoietic stem cells. These HIS-mice are capable of growing human tumor cell lines and patient-derived tumor xenografts. This model allows rapid testing of multiple, immune-related therapeutics for tumors originating from unique clinical samples. Using a cord blood-derived HIS-BALB/c-Rag2nullIl2rγnullSIRPαNOD (BRGS) mouse model, we summarize our experiments testing immune checkpoint blockade combinations in these mice bearing a variety of human tumors, including breast, colorectal, pancreatic, lung, adrenocortical, melanoma and hematological malignancies. We present in-depth characterization of the kinetics and subsets of the HIS in lymph and non-lymph organs and relate these to protocol development and immune-related treatment responses. Furthermore, we compare the phenotype of the HIS in lymph tissues and tumors. We show that the immunotype and amount of tumor infiltrating leukocytes are widely-variable and that this phenotype is tumor-dependent in the HIS-BRGS model. We further present flow cytometric analyses of immune cell subsets, activation state, cytokine production and inhibitory receptor expression in peripheral lymph organs and tumors. We show that responding tumors bear human infiltrating T cells with a more inflammatory signature compared to non-responding tumors, similar to reports of "responding" patients in human immunotherapy clinical trials. Collectively these data support the use of HIS mice as a preclinical model to test combination immunotherapies for human cancers, if careful attention is taken to both protocol details and data analysis.


Subject(s)
Disease Models, Animal , Heterografts , Immune System , Immunotherapy , Neoplasms/immunology , Neoplasms/therapy , Animals , Chimerism , Hematopoietic Stem Cell Transplantation , Humans , Immunotherapy/adverse effects , Immunotherapy/methods , Lymphocyte Subsets/immunology , Lymphocyte Subsets/metabolism , Lymphoid Tissue/immunology , Lymphoid Tissue/metabolism , Mice , Mice, Inbred NOD , Mice, Knockout , Mice, SCID , Neoplasms/etiology , Phenotype , Xenograft Model Antitumor Assays
16.
Geroscience ; 42(6): 1699-1714, 2020 12.
Article in English | MEDLINE | ID: mdl-32770384

ABSTRACT

Endothelial function declines progressively across stages of the menopause transition; however, the mechanisms contributing to this decline are unknown. We hypothesized that differences in endothelial function among pre-, peri, and postmenopausal women are related to differences in estradiol and oxidative stress. Brachial artery flow-mediated dilation (FMD) was measured in 87 healthy women categorized by menopause stage (24 premenopausal, 17 early and 21 late perimenopausal, and 25 postmenopausal) before and after 3 days of ovarian hormone suppression (gonadotropin releasing hormone antagonist [GnRHant]) alone, and an additional 3 days of GnRHant with concurrent transdermal estradiol or placebo add-back treatment. In 82 women, FMD during acute vitamin C (antioxidant) infusion was measured before and after GnRHant + add-back. Before GnRHant, FMD was different among groups (p < 0.005; reduced across stages of menopause). Vitamin C increased FMD in late peri- and post- (p < 0.005) but not pre- or early perimenopausal women (p > 0.54). After GnRHant alone, FMD decreased in pre- and peri- (p < 0.01), but not postmenopausal women, and was restored to premenopausal levels by estradiol add-back in the pre- and perimenopausal groups. Vitamin C improved FMD in pre-, peri-, and postmenopausal women on GnRHant + placebo. There was no effect of vitamin C on FMD in women on GnRHant + estradiol. These observations support the concept that the decline in endothelial function across the menopause transition is related to the loss of ovarian estradiol. The decline in estradiol may alter redox balance, thereby increasing oxidative stress and impairing endothelial function.


Subject(s)
Endothelium, Vascular , Menopause , Endothelium, Vascular/metabolism , Estradiol/metabolism , Female , Humans , Oxidation-Reduction , Oxidative Stress
17.
J Cancer Surviv ; 14(5): 653-659, 2020 10.
Article in English | MEDLINE | ID: mdl-32394045

ABSTRACT

PURPOSE: Colorectal cancer (CRC) is the third most common cancer in the USA. The objective of this study was to compare quality of life (QoL) across long-term colorectal cancer survivors and unaffected matched controls while adjusting for comorbidities. METHODS: The National Cancer Institute (NCI)-funded Colon Cancer Family Registry (CCFR) was used to randomly select and recruit CRC survivors (≥ 5 years from diagnosis) and matched controls for a cross-sectional survey. Nine geographically diverse sites in the USA from the CCFR participated in the study. Telephone interviews were conducted using computer-assisted methods to assess QoL. RESULTS: A total of 403 cases and 401 controls were included in the final sample. Unadjusted comparison revealed no significant difference between CRC survivors and controls with respect to measures of fatigue, social, emotional, functional, and physical well-being. Multivariate logistic regression revealed that case status had a significant negative influence on colorectal cancer-specific QoL measures. Higher comorbidity indices had a significant negative influence on overall QoL regardless of case status. CONCLUSIONS: Quality of life among long-term CRC survivors is similar to control subjects, with the exception of worse CRC-specific QoL measures. Higher comorbidity indices were independently associated with poor QoL for both cases and controls. IMPLICATIONS FOR CANCER SURVIVORS: Survivors and healthcare providers should be aware that long-term QoL is comparable to the general population; however, there is potential that digestive tract-specific issues may persist.


Subject(s)
Cancer Survivors/psychology , Colorectal Neoplasms/psychology , Quality of Life , Registries/statistics & numerical data , Aged , Case-Control Studies , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/therapy , Comorbidity , Cross-Sectional Studies , Female , Health Status , Humans , Male , Middle Aged , United States/epidemiology
18.
PM R ; 12(10): 957-966, 2020 10.
Article in English | MEDLINE | ID: mdl-32248638

ABSTRACT

BACKGROUND: Lower-limb amputation (LLA) due to non-traumatic vascular etiology is linked to extremely low physical activity and high disability. OBJECTIVE: To test the feasibility of a biobehavioral intervention designed to promote physical activity. DESIGN: A randomized, single-blind feasibility trial with a crossover design. SETTING: Veterans Administration Medical Center. PARTICIPANTS: Military veterans (age: 65.7 [7.8] years; mean [standard deviation]) with nontraumatic lower-limb amputation (LLA), randomized to two groups: GROUP1 (n = 16) and GROUP2 (n = 15). Both groups had similar baseline amputation characteristics (level of amputation and time since amputation). INTERVENTIONS: Twelve weekly, 30-minute telehealth sessions of physical activity behavior-change intervention, with GROUP1 participating in weeks 1-12 and GROUP2 in weeks 13-24. GROUP1 noncontact phase in weeks 13-24 and GROUP2 attention control telehealth phase in weeks 1-12. MAIN OUTCOME MEASURES: Feasibility (participant retention, dose goal attainment, intervention acceptability [Intrinsic Motivation Inventory [IMI] Interest and Enjoyment scale], safety) and signal of efficacy (free-living physical activity [accelerometer-based average daily step count], Late Life Function and Disability Index - Disability Scale [LLFDI-DS]). RESULTS: Participant retention rate was high (90%), with three participants lost to follow-up during the intervention period. Dose goal attainment was low, with only 10% of participants achieving an a priori walking dose goal. Intervention was rated as acceptable, with mean IMI Interest and Enjoyment score (5.8) statistically higher than the null value of 5.0 (P = .002). There were no between-group differences in adverse event rates (falls: P = .19, lower extremity wounds: P = .60). There was no signal of efficacy for change in average daily step count (d = -0.15) or LLFDI-DS (d = -0.22 and 0.17 for frequency and limitations scales, respectively). CONCLUSIONS: Telehealth delivered biobehavioral intervention resulted in acceptable participant retention, low dose goal attainment, high participant acceptability, and low safety risk, while having no signal of efficacy (physical activity, disability) for people with nontraumatic LLA.


Subject(s)
Veterans , Aged , Amputation, Surgical , Exercise , Humans , Male , Single-Blind Method , Walking
19.
J Appl Physiol (1985) ; 128(4): 739-747, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32134713

ABSTRACT

Regular exercise enhances endothelial function in older men, but not consistently in estrogen-deficient postmenopausal women. Estradiol treatment improves basal endothelial function and restores improvements in endothelial function (flow-mediated dilation, FMD) to aerobic exercise training in postmenopausal women; however, estradiol treatment is controversial. Resveratrol, an estrogen receptor ligand, enhances exercise training effects on cardiovascular function and nitric oxide (NO) release in animal models, but impairs exercise training effects in men. We conducted a randomized cross-over, double-blinded, placebo-controlled pilot study to determine whether acute (single dose) resveratrol (250-mg tablet) or estradiol (0.05 mg/day transdermal patch) treatment enhances FMD at rest and after a single bout of moderate-intensity aerobic exercise in healthy estrogen-deficient postmenopausal women (n = 15, 58.1 ± 3.2 yr). FMD was measured before and after (30, 60, and 120 min) a 40-min bout of moderate-intensity treadmill exercise (60-75% peak heart rate) under the respective conditions (separated by 1-2 wk). FMD was higher (P < 0.05) before exercise and at all post-exercise time points in the resveratrol and estradiol conditions compared to placebo. FMD was increased from baseline by 120 min postexercise in the estradiol condition (P < 0.001), but not resveratrol or PL conditions. Consistent with our previous findings, estradiol also enhances endothelial function in response to acute endurance exercise. Although resveratrol improved basal FMD, there was no apparent enhancement of FMD to acute exercise and, therefore, may not act as an estradiol mimetic.NEW & NOTEWORTHY The benefits of endurance exercise training on endothelial function are diminished in estrogen-deficient postmenopausal women, but estradiol treatment appears to restore improvements in endothelial function in this group. We show that basal endothelial function is enhanced with both acute estradiol and resveratrol treatments in estrogen-deficient postmenopausal women, but endothelial function is only enhanced following acute endurance exercise with estradiol treatment.


Subject(s)
Brachial Artery , Estradiol , Aged , Endothelium, Vascular , Estrogens , Female , Humans , Male , Postmenopause , Resveratrol/pharmacology , Vasodilation
20.
Int J Sports Phys Ther ; 14(3): 334-344, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31681492

ABSTRACT

BACKGROUND: The same trauma that produces concussion may also produce neck injury. The signs of concussion and neck injury are similar, and symptoms after acceleration-deceleration trauma to the head-neck complex do not accurately discriminate between them. Research on the epidemiology of neck injury among sport-concussed youth is sparse. PURPOSE: The purpose of this study was to investigate the epidemiology of diagnosed neck injury in non-sport-related concussion (Non-SRC) versus sport-related concussion (SRC) in youth by age, sex, and sport. STUDY DESIGN: Cross-sectional epidemiologic study. METHODS: De-identified data from community-based electronic health records over 13 years were extracted to analyze rates and characteristics of neck injuries among non-SRCs and SRCs in youth aged five to 21. Neck injury diagnosis prevalence rates and odds ratios were calculated to estimate risk of neck injury among concussed youth, comparing non-SRCs to SRCs by age and sex. RESULTS: Sixteen thousand, eight hundred eighty-five concussion records were extracted, of which 3,040 SRCs and 2,775 non-SRCs in youth aged five to 21 were identified by cross-filtering sport-related keywords (e.g., football, basketball, soccer, running, swimming, batting, horseback riding, skiing, etc.) with all ICD-9 and ICD-10 concussion codes. The prevalence of neck injuries diagnosed among SRCs (7.2%) was significantly different than the prevalence of neck injuries diagnosed among non-SRCs (12.1%, p < 0.000). Neck injury diagnoses were significantly more prevalent in females overall (p < 0.000) and among non-SRCs (p < 0.000). The prevalence of neck injury diagnoses was not significantly higher in concussed females versus concussed males with SRC (p = 0.164).Among youth aged five to 21 exposed to concussions, non-SRCs were more likely to be accompanied by a neck injury diagnosis than SRCs (OR 1.66; 95% CI 1.39 to 1.98; p < 0.000). Similarly, female-to-male neck injury proportion ratios were significantly higher in females in non-SRCs compared to SRCs (IPR 1.90, 95% CI 1.60 to 2.25, p < 0.000).Sports with highest prevalence of concussion differ from sports with highest prevalence of concussion-related neck injury in both sexes. CONCLUSIONS: The overall prevalence of diagnosed neck injuries in youth was higher in non-SRCs compared to SRCs (12.1 vs. 7.2%, p < 0.001), with the highest prevalence at age 14 in both sexes. The risk of neck injury diagnosis accompanying concussion was significantly higher in females compared to males (6.1% difference; p < 0.000).

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