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1.
Toxics ; 11(3)2023 Mar 21.
Article in English | MEDLINE | ID: mdl-36977054

ABSTRACT

The sustained growth of the market for ophthalmic medical devices has increased the demand for alternatives to animal testing for the evaluation of eye irritation. The International Organization for Standardization has acknowledged the need to develop novel in vitro tests to replace animal testing. Here, we evaluated the applicability of an alternative method based on a human corneal model to test the safety of ophthalmic medical devices. 2-Hydroxyethyl methacrylate (HEMA) and Polymethyl methacrylate (PMMA), which are used to fabricate contact lenses, were used as base materials. These materials were blended with eye irritant and non-irritant chemicals specified in the OECD Test Guideline (TG) 492 and Globally Harmonized System (GHS) classification. Then, three GLP-certified laboratories performed three replicates using the developed method using 3D reconstructed human cornea epithelium, MCTT HCETM. OECD TG 492 describes the procedure used to evaluate the eye hazard potential of the test chemical based on its ability to induce cytotoxicity in a reconstructed human cornea-like epithelium (RhCE) tissue. Results: The within-laboratory reproducibility (WLR) and between-laboratory reproducibility (BLR) were both 100%. When a polar extraction solvent was used, the sensitivity, specificity, and accuracy were all 100% in each laboratory. When a non-polar extraction solvent was used, the sensitivity was 80%, the specificity was 100%, and the accuracy was 90%. The proposed method exhibited excellent reproducibility and predictive capacity within and between laboratories. Therefore, the proposed method using the MCTT HCETM model could be used to evaluate eye irritation caused by ophthalmic medical devices.

2.
Molecules ; 27(13)2022 Jun 24.
Article in English | MEDLINE | ID: mdl-35807312

ABSTRACT

Siryung-tang (SRT) is a traditional herbal prescription containing Oryeong-san and Soshiho-tang that is used to treat digestive system diseases. We performed safety evaluations of SRT based on genotoxicity and developed an assay for quality control using high-performance liquid chromatography with a photodiode array detector. Genotoxicity was evaluated based on bacterial reverse mutation (Salmonella typhimurium TA1535, TA98, TA100, and TA1537, and Escherichia coli WP2 uvrA), chromosomal aberration (Chinese hamster lung cells), and micronucleus (mouse) tests. Quality control analysis was conducted using a SunFire C18 column and gradient elution with a distilled water-acetonitrile mobile phase system containing 0.1% (v/v) formic acid for 12 markers (5-(hydroxy-methyl)furfural, 3,4-dihydroxybenzaldehyde, liquiritin apioside, liquiritin, coumarin, baicalin, wogonoside, cinnamaldehyde, baicalein, glycyrrhizin, wogonin, and atractylenolide III). SRT showed no genotoxicity in three tests. Ames tests showed that SRT at 313-5000 µg/plate did not significantly increase the number of revertant colonies with or without metabolic activation among five bacterial strains. Moreover, in vivo micronucleus testing showed that SRT did not increase the frequency of bone marrow micronuclei. The number of chromosomal aberrations associated with SRT was similar to that observed in the negative controls. The 12 markers were detected at 0.04-16.86 mg/g in a freeze-dried SRT sample and completely eluted within 45 min. The extraction recovery was 95.39-104.319% and the relative standard deviation value of the precision was ≤2.09%. Our study will be used as basic data for the safety and standardization of SRT.


Subject(s)
Chromosome Aberrations , Phytochemicals , Animals , Cricetinae , Cricetulus , Escherichia coli/genetics , Mice , Mice, Inbred ICR , Micronucleus Tests , Mutagenicity Tests/methods , Prescriptions
3.
JMIR Res Protoc ; 10(6): e26264, 2021 Jun 11.
Article in English | MEDLINE | ID: mdl-34114954

ABSTRACT

BACKGROUND: In hereditary breast and ovarian cancer (HBOC), family communication of genetic test results is essential for cascade genetic screening, that is, identifying and testing blood relatives of known mutation carriers to determine whether they also carry the pathogenic variant, and to propose preventive and clinical management options. However, up to 50% of blood relatives are unaware of relevant genetic information, suggesting that potential benefits of genetic testing are not communicated effectively within family networks. Technology can facilitate communication and genetic education within HBOC families. OBJECTIVE: The aims of this study are to develop the K-CASCADE (Korean-Cancer Predisposition Cascade Genetic Testing) cohort in Korea by expanding an infrastructure developed by the CASCADE (Cancer Predisposition Cascade Genetic Testing) Consortium in Switzerland; develop a digital health intervention to support the communication of cancer predisposition for Swiss and Korean HBOC families, based on linguistic and cultural adaptation of the Family Gene Toolkit; evaluate its efficacy on primary (family communication of genetic results and cascade testing) and secondary (psychological distress, genetic literacy, active coping, and decision making) outcomes; and explore its translatability using the reach, effectiveness, adoption, implementation, and maintenance framework. METHODS: The digital health intervention will be available in French, German, Italian, Korean, and English and can be accessed via the web, mobile phone, or tablet (ie, device-agnostic). K-CASCADE cohort of Korean HBOC mutation carriers and relatives will be based on the CASCADE infrastructure. Narrative data collected through individual interviews or mini focus groups from 20 to 24 HBOC family members per linguistic region and 6-10 health care providers involved in genetic services will identify the local cultures and context, and inform the content of the tailored messages. The efficacy of the digital health intervention against a comparison website will be assessed in a randomized trial with 104 HBOC mutation carriers (52 in each study arm). The translatability of the digital health intervention will be assessed using survey data collected from HBOC families and health care providers. RESULTS: Funding was received in October 2019. It is projected that data collection will be completed by January 2023 and results will be published in fall 2023. CONCLUSIONS: This study addresses the continuum of translational research, from developing an international research infrastructure and adapting an existing digital health intervention to testing its efficacy in a randomized controlled trial and exploring its translatability using an established framework. Adapting existing interventions, rather than developing new ones, takes advantage of previous valid experiences without duplicating efforts. Culturally sensitive web-based interventions that enhance family communication and understanding of genetic cancer risk are timely. This collaboration creates a research infrastructure between Switzerland and Korea that can be scaled up to cover other hereditary cancer syndromes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04214210; https://clinicaltrials.gov/ct2/show/NCT04214210 and CRiS KCT0005643; https://cris.nih.go.kr/cris/. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/26264.

4.
Toxicol In Vitro ; 75: 105136, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33675894

ABSTRACT

Although in vivo inhalation toxicity tests have been widely conducted, the testing of many chemicals is limited for economic and ethical reasons. Therefore, we previously developed an in vitro acute inhalation toxicity test method. The goal of the present pre-validation study was to evaluate the transferability, reproducibility, and predictive capacity of this method. After confirming the transferability of the Calu-3 epithelium cytotoxicity assay, reproducibility was evaluated using 20 test substances at three independent institutions. Cytotoxicity data were analyzed using statistical methods, including the intra-class correlation coefficient and Bland-Altman plots for within- and between-laboratory reproducibility. The assay for the 20 test substances showed excellent agreement within and between laboratories. To evaluate the predictive capacity, 77 test substances were analyzed for acute inhalation toxicity. Accuracy was measured using a cutoff of 40%, and the relevance was analyzed as a receiver-operating characteristic (ROC) curve. An accuracy of 72.73% was obtained, and the area under the ROC curve was 0.77, indicating moderate performance. In this study, we found that the in vitro acute inhalation toxicity test method demonstrated good reliability and relevance for predicting the acute toxicity of inhalable chemicals. Hence, this assay has potential as an alternative test for screening acutely toxic inhalants.


Subject(s)
Biological Assay/methods , Inhalation Exposure/adverse effects , Toxicity Tests, Acute/methods , Administration, Inhalation , Animal Testing Alternatives , Cell Line, Tumor , Epithelium , Humans , Reproducibility of Results
5.
J Pain Symptom Manage ; 59(6): 1172-1185, 2020 06.
Article in English | MEDLINE | ID: mdl-31953207

ABSTRACT

CONTEXT: Although approximately 75% of patients with breast cancer report changes in attentional function, little is known about how demographic, clinical, symptom, and psychosocial adjustment (e.g., coping) characteristics influence changes in the trajectories of attentional function over time. OBJECTIVES: This study evaluated interindividual variability in the trajectories of self-reported attentional function and determined which demographic, clinical, symptom, and psychosocial adjustment characteristics were associated with initial levels and with changes in attentional function from before through 12 months after breast cancer surgery. METHODS: Before surgery, 396 women were enrolled. Attentional Function Index (AFI) was completed before and nine times within the first 12 months after surgery. Hierarchical linear modeling was used to determine which characteristics were associated with initial levels and trajectories of attentional function. RESULTS: Given an estimated preoperative AFI score of 6.53, for each additional month, the estimated linear rate of change in AFI score was an increase of 0.054 (P < 0.001). Higher levels of comorbidity, receipt of adjuvant chemotherapy, higher levels of trait anxiety, fatigue, and sleep disturbance, and lower levels of energy and less sense of control were associated with lower levels of attentional function before surgery. Patients who had less improvements in attentional function over time were nonwhite, did not have a lymph node biopsy, had received hormonal therapy, and had less difficulty coping with their disease. CONCLUSION: Findings can be used to identify patients with breast cancer at higher risk for impaired self-reported cognitive function and to guide the prescription of more personalized interventions.


Subject(s)
Breast Neoplasms , Sleep Wake Disorders , Attention , Breast Neoplasms/surgery , Fatigue , Female , Humans , Mastectomy
6.
Toxicol In Vitro ; 55: 173-184, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30572010

ABSTRACT

The need for in vitro eye irritation test replacing in vivo is steadily increasing. The MCTT HCE™ eye irritation test (EIT) using 3D reconstructed human cornea-like epithelium, was developed to identify ocular irritants from non-irritants those that are not requiring classification and labelling for eye irritation. Here, we report the results of me-too validation study, which was conducted to evaluate the reliability and relevance of the MCTT HCETM EIT, according to performance standards (PS) of OECD TG 492. The optimal cutoff to determine irritation in the prediction model was preliminarily established at 45% with the receiver operation characteristics (ROC) curve for 141 reference substances. To demonstrate the reproducibility of within- and between-laboratory (WLR and BLR), a set of 30 PS reference chemicals were tested in three laboratories three times. The WLR and BLR concordance with the binary decision of whether non-irritant or irritant was estimated to be 90-100% and 90%, respectively, and both met the PS requirements. The predictive capacity of the respective laboratories for the 30 reference chemicals were evaluated based on three different estimation methods, and the results were comparable, with sensitivity ranging from 89.6 to 93.3%, the specificity ranging from 62.2 to 66.7%, and the accuracy ranging from 75.9 to 80.0%. Additional test with the new set of 30 PS substances in the revised OECD GD 216 yielded a performance of sensitivity ranging from 92.6-93.3%, the specificity 62.2-66.7% and the accuracy 77.4-80.0%. 95.0% sensitivity, 67.2% specificity, and 83.0% accuracy were obtained for 141 reference substances in total. Furthermore, separate cutoffs for liquids and solids, 35% and 60%, respectively, produced better predictivity, which was established as a final prediction model. Collectively, our study demonstrated that MCTT HCETM EIT meets the reproducibility and predictivity criteria stated in OECD TG 492 PS.


Subject(s)
Animal Testing Alternatives , Epithelium, Corneal/drug effects , Irritants/toxicity , Toxicity Tests/methods , Humans , Reproducibility of Results
7.
Res Theory Nurs Pract ; 31(3): 233-246, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28793947

ABSTRACT

PURPOSE: The purpose of this study was to assess the psychometric properties of the Barriers or Facilitators to Using Research in Practice (BARRIERS) scale for use in Korea. METHODS: A cross-sectional study design was used with 364 nurses working in clinical settings. Item analysis was conducted and convergent and discriminant validity were evaluated using confirmatory factor analysis. Internal consistency reliability was evaluated using Cronbach's alpha coefficients. RESULTS: Confirmatory factor analysis revealed a 4-factor structure with 25 items that explained 62.9% of the variance. Convergent and discriminant validity were confirmed as examining the factor loading, average variance extracted, and composite reliability. The values of factor loading for 25 items were having higher estimate than criterion and the average variance extracted value for 4 factors ranged from .575 to .667. The Cronbach's alpha was .90 for the 25 items. CONCLUSION: The Korean version of the 25-item BARRIERS scale was a reliable and valid scale to measure barriers to research use in Korean health care settings. Based on this psychometric evaluation, research barriers and its associated factors will be investigated using the Korean version of the BARRIERS scale in further study.


Subject(s)
Communication Barriers , Nursing Research , Nursing Staff, Hospital/psychology , Translations , Adult , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Psychometrics , Reproducibility of Results , Republic of Korea , Young Adult
8.
Regul Toxicol Pharmacol ; 85: 124-131, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28193562

ABSTRACT

Recently UN GHS has introduced the sub-categorization of skin sensitizers for which ECt (concentration estimated to induce stimulation index above threshold) of the murine local lymph node assay (LLNA) is used as criteria. Non-radioisotopic variants of LLNA, LLNA: DA, LLNA: BrdU-ELISA, LNCC and LLNA: BrdU-FCM were developed yet their utilities for potency sub-categorization are not established. Here we assessed the agreement of LLNA variants with LLNA or human data in potency sub-categorization for 22 reference substances of OECD TG429. Concordance of sub-categorization with LLNA was highest for LLNA: BrdU-FCM(91%, κ = 0.833, weighted kappa) followed by LLNA: BrdU-ELISA (82%, κ = 0.744) and LLNA: DA (73%, κ = 0.656) whereas LNCC only showed a modest association (64%, κ = 0.441). With human data, LLNA agreed best (77%) followed by LLNA: DA and LLNA: BrdU-FCM(73%), LLNA: BrdU-ELISA (68%) and LNCC(55%). Bland-Altman plot revealed that ECt's of LLNA variants largely agreed with LLNA where most values fell within 95% limit of agreement. Correlation between ECt's of LLNA and LLNA variants were high except for LNCC(pair-wise with LLNA, LLNA: DA, r = 0.848, LLNA: BrdU-ELISA, r = 0.744, LLNA: BrdU-FCM, r=0.786, and LNCC, r = 0.561 by Pearson). Collectively, these results demonstrated that LLNA variants exhibit performance comparable to LLNA in the potency sub-categorization although additional substances shall be analyzed in the future.


Subject(s)
Dermatitis, Allergic Contact , Local Lymph Node Assay , Allergens/classification , Allergens/toxicity , Animals , Haptens/classification , Haptens/toxicity , Humans , Mice , Radioisotopes , Reproducibility of Results , United Nations
9.
Regul Toxicol Pharmacol ; 83: 13-22, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27816673

ABSTRACT

The local lymph node assay using 5-bromo-2-deoxyuridine (BrdU) with flow cytometry (LLNA: BrdU-FCM) is a modified LLNA that is used to identify skin sensitizers by counting BrdU-incorporated lymph node cells (LNCs) with flow cytometry. Unlike other LLNA methods (OECD TG 429, 442A and 442B) in which the CBA/J mouse strain is used, LLNA: BrdU-FCM was originally designed to be compatible with BALB/c, a mouse strain that is more widely used in many countries. To justify the substitution of CBA/J for BALB/c, the equivalence of the test results between two strains shall be established prior to the official implementation of LLNA: BrdU-FCM. This study aims to compare the test results of LLNA: BrdU-FCM produced in BALB/c mice with those in CBA/J mice for 18 reference substances, including 13 sensitizers and 5 non-sensitizers, listed in OECD Test Guideline 429. Based on the LLNA: BrdU-FCM test procedure, we selected an appropriate solvent and then performed preliminary tests to determine the non-irritating dose ranges for the main study, which revealed the difference in the irritation responses to 8 of the 18 chemicals between the two strains. In the main study, we measured the changes in the number of total LNCs, which indicated differences in the responses to test chemicals between the two strains. However, the stimulation index obtained with the counts of BrdU-incorporated LNCs with 7-AAD using flow cytometry yielded comparable results and 100% concordance between the BALB/c and CBA/J mouse strains was achieved, suggesting that the performance of LLNA: BrdU-FCM using BALB/c mice was equivalent to that with CBA/J mice.


Subject(s)
Bromodeoxyuridine , Cell Proliferation/drug effects , Dermatitis, Allergic Contact/etiology , Flow Cytometry , Irritants/toxicity , Local Lymph Node Assay , Lymph Nodes/drug effects , Administration, Cutaneous , Animals , Dose-Response Relationship, Drug , Female , Irritants/administration & dosage , Lymph Nodes/pathology , Mice, Inbred BALB C , Mice, Inbred CBA , Reproducibility of Results , Species Specificity , Time Factors
10.
Toxicol In Vitro ; 39: 58-67, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27876558

ABSTRACT

Here, we report the results of a prevalidation trial for an in vitro eye irritation test (EIT) using the reconstructed human cornea-like epithelium, MCTT HCE™. The optimal cutoff to determine irritation in the prediction model was established at 35% with the receiver operation characteristics(ROC) curve for 126 substances. Within-lab(WL) and between-lab(BL) reproducibility was tested for 20 reference substances by 3 participating laboratories. Viability data described by mean±SD or ±1/2 difference between duplicate wells, and scatter plots, demonstrated the WL/BL consistency. WL/BL concordance with the binary decision, whether non-irritant or irritant was estimated to be 85-95% and 95%, respectively. WL/BL reproducibility of viability data was further supported by a strong correlation(ICC, r>0.9). WL/BL agreement of binary decisions was also examined by Fleiss' Kappa statistics, which showed a strong level of agreement (>0.78), nevertheless weaker than the reproducibility of the viability. The EIT with MCTT HCE™ exhibited a sensitivity of 82.2% (60/73), a specificity of 81.1% (43/53), and an accuracy of 81.8% (103/126) for 126 reference substances (for liquids; a sensitivity of 100% (47/47), a specificity of 70.6% (24/34), and an accuracy of 87.7% (71/81), and for solids, a sensitivity of 50% (13/26), a specificity of 100% (19/19), and an accuracy of 71.1% (32/45), suggesting that the accuracy is satisfactory but the sensitivity needs improvement, which shall be addressed through correcting the poor sensitivity for solid substances in future full validation trials.


Subject(s)
Epithelium, Corneal/drug effects , Irritants/toxicity , Animal Testing Alternatives , Cell Survival/drug effects , Humans , In Vitro Techniques , Reproducibility of Results , Sensitivity and Specificity
11.
Regul Toxicol Pharmacol ; 80: 183-94, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27318101

ABSTRACT

Local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method (LLNA: BrdU-FCM) is a modified non-radioisotopic technique with the additional advantages of accommodating multiple endpoints with the introduction of FCM, and refinement and reduction of animal use by using a sophisticated prescreening scheme. Reliability and accuracy of the LLNA: BrdU-FCM was determined according to OECD Test Guideline (TG) No. 429 (Skin Sensitization: Local Lymph Node Assay) performance standards (PS), with the participation of four laboratories. Transferability was demonstrated through successfully producing stimulation index (SI) values for 25% hexyl cinnamic aldehyde (HCA) consistently greater than 3, a predetermined threshold, by all participating laboratories. Within- and between-laboratory reproducibility was shown using HCA and 2,4-dinitrochlorobenzene, in which EC2.7 values (the estimated concentrations eliciting an SI of 2.7, the threshold for LLNA: BrdU-FCM) fell consistently within the acceptance ranges, 0.025-0.1% and 5-20%, respectively. Predictive capacity was tested using the final protocol version 1.3 for the 18 reference chemicals listed in OECD TG 429, of which results showed 84.6% sensitivity, 100% specificity, and 88.9% accuracy compared with the original LLNA. The data presented are considered to meet the performance criteria for the PS, and its predictive capacity was also sufficiently validated.


Subject(s)
Acrolein/analogs & derivatives , Bromodeoxyuridine , Dinitrochlorobenzene/toxicity , Flow Cytometry , Laboratory Proficiency Testing , Local Lymph Node Assay , Lymph Nodes/drug effects , Acrolein/toxicity , Animals , Female , Flow Cytometry/standards , Guideline Adherence , Guidelines as Topic , Humans , Lymph Nodes/pathology , Mice , Mice, Inbred BALB C , Observer Variation , Predictive Value of Tests , Reproducibility of Results , Republic of Korea
12.
Article in English | MEDLINE | ID: mdl-26654807

ABSTRACT

In order for a novel test method to be applied for regulatory purposes, its reliability and relevance, i.e., reproducibility and predictive capacity, must be demonstrated. Here, we examine the predictive capacity of a novel non-radioisotopic local lymph node assay, LLNA:BrdU-FCM (5-bromo-2'-deoxyuridine-flow cytometry), with a cutoff approach and inferential statistics as a prediction model. 22 reference substances in OECD TG429 were tested with a concurrent positive control, hexylcinnamaldehyde 25%(PC), and the stimulation index (SI) representing the fold increase in lymph node cells over the vehicle control was obtained. The optimal cutoff SI (2.7≤cutoff <3.5), with respect to predictive capacity, was obtained by a receiver operating characteristic curve, which produced 90.9% accuracy for the 22 substances. To address the inter-test variability in responsiveness, SI values standardized with PC were employed to obtain the optimal percentage cutoff (42.6≤cutoff <57.3% of PC), which produced 86.4% accuracy. A test substance may be diagnosed as a sensitizer if a statistically significant increase in SI is elicited. The parametric one-sided t-test and non-parametric Wilcoxon rank-sum test produced 77.3% accuracy. Similarly, a test substance could be defined as a sensitizer if the SI means of the vehicle control, and of the low, middle, and high concentrations were statistically significantly different, which was tested using ANOVA or Kruskal-Wallis, with post hoc analysis, Dunnett, or DSCF (Dwass-Steel-Critchlow-Fligner), respectively, depending on the equal variance test, producing 81.8% accuracy. The absolute SI-based cutoff approach produced the best predictive capacity, however the discordant decisions between prediction models need to be examined further.


Subject(s)
Bromodeoxyuridine/analysis , Bromodeoxyuridine/chemistry , Flow Cytometry/methods , Local Lymph Node Assay , Animals , Flow Cytometry/standards , Forecasting , Mice , Mice, Inbred BALB C
13.
Toxicol Lett ; 234(3): 172-9, 2015 May 05.
Article in English | MEDLINE | ID: mdl-25732604

ABSTRACT

Mouse local lymph node assay (LLNA, OECD TG429) is an alternative test replacing conventional guinea pig tests (OECD TG406) for the skin sensitization test but the use of a radioisotopic agent, (3)H-thymidine, deters its active dissemination. New non-radioisotopic LLNA, LLNA:BrdU-FCM employs a non-radioisotopic analog, 5-bromo-2'-deoxyuridine (BrdU) and flow cytometry. For an analogous method, OECD TG429 performance standard (PS) advises that two reference compounds be tested repeatedly and ECt(threshold) values obtained must fall within acceptable ranges to prove within- and between-laboratory reproducibility. However, this criteria is somewhat arbitrary and sample size of ECt is less than 5, raising concerns about insufficient reliability. Here, we explored various statistical methods to evaluate the reproducibility of LLNA:BrdU-FCM with stimulation index (SI), the raw data for ECt calculation, produced from 3 laboratories. Descriptive statistics along with graphical representation of SI was presented. For inferential statistics, parametric and non-parametric methods were applied to test the reproducibility of SI of a concurrent positive control and the robustness of results were investigated. Descriptive statistics and graphical representation of SI alone could illustrate the within- and between-laboratory reproducibility. Inferential statistics employing parametric and nonparametric methods drew similar conclusion. While all labs passed within- and between-laboratory reproducibility criteria given by OECD TG429 PS based on ECt values, statistical evaluation based on SI values showed that only two labs succeeded in achieving within-laboratory reproducibility. For those two labs that satisfied the within-lab reproducibility, between-laboratory reproducibility could be also attained based on inferential as well as descriptive statistics.


Subject(s)
Flow Cytometry , Local Lymph Node Assay , Animals , Bromodeoxyuridine , Flow Cytometry/methods , Flow Cytometry/standards , Mice , Reference Standards , Reproducibility of Results
14.
PLoS One ; 9(10): e111007, 2014.
Article in English | MEDLINE | ID: mdl-25350370

ABSTRACT

Functional brain networks emerge and dissipate over a primarily static anatomical foundation. The dynamic basis of these networks is inter-regional communication involving local and distal regions. It is assumed that inter-regional distances play a pivotal role in modulating network dynamics. Using three different neuroimaging modalities, 6 datasets were evaluated to determine whether experimental manipulations asymmetrically affect functional relationships based on the distance between brain regions in human participants. Contrary to previous assumptions, here we show that short- and long-range connections are equally likely to strengthen or weaken in response to task demands. Additionally, connections between homotopic areas are the most stable and less likely to change compared to any other type of connection. Our results point to a functional connectivity landscape characterized by fluid transitions between local specialization and global integration. This ability to mediate functional properties irrespective of spatial distance may engender a diverse repertoire of cognitive processes when faced with a dynamic environment.


Subject(s)
Brain Mapping , Brain/physiology , Adolescent , Adult , Aged , Breast Neoplasms/psychology , Child , Depression/psychology , Female , Humans , Learning , Least-Squares Analysis , Magnetic Resonance Imaging , Magnetoencephalography , Male , Middle Aged , Models, Statistical , Nerve Net , Neural Pathways/physiology , Principal Component Analysis , Young Adult
15.
Breast Cancer Res Treat ; 147(2): 445-55, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25138546

ABSTRACT

The aim of this study is to use functional magnetic resonance imaging (fMRI) to prospectively examine pre-treatment predictors of post-treatment fatigue and cognitive dysfunction in women treated with adjuvant chemotherapy for breast cancer. Fatigue and cognitive dysfunction often co-occur in women treated for breast cancer. We hypothesized that pre-treatment factors, unrelated to chemotherapy per se, might increase vulnerability to post-treatment fatigue and cognitive dysfunction. Patients treated with (n = 28) or without chemotherapy (n = 37) and healthy controls (n = 32) were scanned coincident with pre- and one-month post-chemotherapy during a verbal working memory task (VWMT) and assessed for fatigue, worry, and cognitive dysfunction. fMRI activity measures in the frontoparietal executive network were used in multiple linear regression to predict post-treatment fatigue and cognitive function. The chemotherapy group reported greater pre-treatment fatigue than controls and showed compromised neural response, characterized by higher spatial variance in executive network activity, than the non-chemotherapy group. Also, the chemotherapy group reported greater post-treatment fatigue than the other groups. Linear regression indicated that pre-treatment spatial variance in executive network activation predicted post-treatment fatigue severity and cognitive complaints, while treatment group, age, hemoglobin, worry, and mean executive network activity levels did not predict these outcomes. Pre-treatment neural inefficiency (indexed by high spatial variance) in the executive network, which supports attention and working memory, was a better predictor of post-treatment cognitive and fatigue complaints than exposure to chemotherapy per se. This executive network compromise could be a pre-treatment neuromarker of risk, indicating patients most likely to benefit from early intervention for fatigue and cognitive dysfunction.


Subject(s)
Breast Neoplasms/drug therapy , Breast Neoplasms/psychology , Cognition Disorders/chemically induced , Fatigue/chemically induced , Magnetic Resonance Imaging/methods , Biomarkers/metabolism , Breast Neoplasms/metabolism , Chemotherapy, Adjuvant/adverse effects , Cognition/drug effects , Cognition Disorders/diagnosis , Fatigue/diagnosis , Female , Humans , Longitudinal Studies , Memory, Short-Term/drug effects , Middle Aged , Neuropsychological Tests , Prospective Studies
16.
J Phys Ther Sci ; 26(3): 381-4, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24707088

ABSTRACT

[Purpose] Age-related mediolateral (ML) instability of static postural control in the elderly has been well studied. Recent studies have provided evidence that ML center of pressure (CoP) parameters during dynamic postural control are more sensitive for differentiation of the fallers in the elderly. However, very limited studies have been done in which ML stability differences between fallers and non-fallers were investigated. The purpose of this study was to investigate the differences in ML CoP parameters between elderly fallers and elderly non-fallers during dynamic postural control. [Subjects and Methods] Twenty-nine community-dwelling older adults were divided into either fallers or non-fallers according to a self-report related to falling history within a year. Every participant performed 4 different tasks (static postural control tasks comprising quiet stance with eyes open and eyes closed and dynamic postural control tasks comprising stance with arm lifting and with trunk flexion) on force plates. [Results] The fallers demonstrated decreased AP and ML CoP parameters, and ML CoP distance was significantly smaller than in the non-fallers during both dynamic postural control tasks. [Conclusions] ML CoP parameters were able to differentiate the fallers from the non-fallers in a community-dwelling elderly population.

17.
Health Psychol ; 33(3): 222-31, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23914817

ABSTRACT

UNLABELLED: [Correction Notice: An Erratum for this article was reported in Vol 33(3) of Health Psychology (see record 2014-07787-001). The name of author Misook Jung was misspelled as Mi Sook Jung. All versions of this article have been corrected.] OBJECTIVE: Altered cognitive function has been associated with breast cancer treatment, particularly adjuvant chemotherapy, but the underlying neuropsychological mechanisms are not yet understood. Recent research indicates that compromised attention and working memory can exist before adjuvant treatment, implicating psychological distress, such as worry, as a possible contributor to observed alterations in cognitive function. We hypothesized that worry associated with breast cancer diagnosis might influence neurocognitive responses before any adjuvant therapy. DESIGN: Fifty women, 25 due to receive chemotherapy and 25 due to receive radiation therapy, participated in the study. Women performed a verbal working memory task during functional magnetic resonance imaging scanning to assess neurocognitive responses before any adjuvant treatment and to test the relationship of such responses with self-reports of worry. RESULTS: Although prechemotherapy participants showed significantly higher levels of worry compared with preradiation participants, higher worry, across both groups, was related to altered brain function. Specifically, increased worry was associated with reduced demand-related deactivation in default-mode regions, such as the precuneus/posterior cingulate. Reduced demand-related deactivation was critically related to worse behavioral performance, which was partially mediated by worry. CONCLUSION: Worry appears to be a significant contributor to neurocognitive dysfunction independent of adjuvant treatment for breast cancer. These results suggest that alterations in cognitive function may develop before any chemotherapy treatment and that worry about cancer diagnosis may contribute to reports of "chemo brain" during treatment. Psychological interventions aimed at mitigating worry may help to alleviate cognitive dysfunction associated with life-threatening illness such as breast cancer.


Subject(s)
Anxiety/complications , Breast Neoplasms/drug therapy , Breast Neoplasms/psychology , Cognition Disorders/etiology , Adult , Aged , Brain/physiopathology , Chemotherapy, Adjuvant , Female , Humans , Magnetic Resonance Imaging , Memory, Short-Term/physiology , Middle Aged , Treatment Outcome
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