Tag: pubmed

Nanotoxicology. 2021 Jul 23:1-10. doi: 10.1080/17435390.2021.1951387. Online ahead of print.

ABSTRACT

Quantitative structure-property/activity relationships (QSPRs/QSARs) are an important component of modern science. Validation of the QSPR/QSAR is the basis for applying. The system of self-consistent models is a new approach to validate QSPR/QSAR. The principle ‘QSAR is a random event’ means that an approach may be recognized as robust only if the statistical characteristics of models obtained by this approach for different splits (training/test) are reproduced. The above principle applies to the case of the nano-QSAR, also. Here, the cellular uptake of nanoparticles in pancreatic cancer cells examines as the endpoint. Groups of models for different splits (training/test) are compared. This comparison gives the possibility to formulate the system of self-consistent models as a way to assess the predictive potential for an arbitrary QSPR/QSAR and/or nano-QSPR/QSAR. The correlation intensity index (CII) has been tested as a tool to improve the quality of models for the cellular uptake of nanoparticles in pancreatic cancer cells (PaCa2). It has shown, that the CII can be useful, but only incorporating with the Index of ideality of correlation (IIC).

PMID:34297644 | DOI:10.1080/17435390.2021.1951387

Anal Chem. 2021 Jul 23. doi: 10.1021/acs.analchem.1c01792. Online ahead of print.

ABSTRACT

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is an established tool for the investigation of formalin-fixed paraffin-embedded (FFPE) tissue samples and shows a high potential for applications in clinical research and histopathological tissue classification. However, the applicability of this method to serial clinical and pharmacological studies is often hampered by inevitable technical variation and limited reproducibility. We present a novel spectral cross-normalization algorithm that differs from the existing normalization methods in two aspects: (a) it is based on estimating the full statistical distribution of spectral intensities and (b) it involves applying a non-linear, mass-dependent intensity transformation to align this distribution with a reference distribution. This method is combined with a model-driven resampling step that is specifically designed for data from MALDI imaging of tryptic peptides. This method was performed on two sets of tissue samples: a single human teratoma sample and a collection of five tissue microarrays (TMAs) of breast and ovarian tumor tissue samples (N = 241 patients). The MALDI MSI data was acquired in two labs using multiple protocols, allowing us to investigate different inter-lab and cross-protocol scenarios, thus covering a wide range of technical variations. Our results suggest that the proposed cross-normalization significantly reduces such batch effects not only in inter-sample and inter-lab comparisons but also in cross-protocol scenarios. This demonstrates the feasibility of cross-normalization and joint data analysis even under conditions where preparation and acquisition protocols themselves are subject to variation.

PMID:34297545 | DOI:10.1021/acs.analchem.1c01792

J Adolesc Young Adult Oncol. 2021 Jul 23. doi: 10.1089/jayao.2021.0072. Online ahead of print.

ABSTRACT

Introduction: Children, adolescents, and young adults (AYAs) with cancer are a special population who are subjected to a number of unique challenges, stressors, and barriers to high-quality psychological care. In a recent systematic review of measurement properties, we found that 5 of 18 identified patient-reported outcome measures (PROMs) had sufficient psychometric properties to justify their use. A next step is to analyze the reliability of these scale scores in a reliability-generalization meta-analysis. Methods: We conducted a systematic review of three databases for all studies reporting reliability data for previously identified PROMs. Included studies were further required to include patients with cancer, or survivors of cancer, ages 2-39. We next synthesized alpha and test-retest coefficients using best statistical practices, according to prespecified subgroups, where possible. We considered a threshold of 0.7 to represent sufficient evidence of reliability. Results: Seventy-one studies were included. Overall, reliability coefficients for scale and subscale scores exceeded 0.7. Subgroup analyses were limited by incomplete reporting and a lack of sufficient studies for each subgroup; however, where conducted, these subgroup analyses showed significant differences in the reliability of self-reports versus proxy reports and original versus adapted versions of PROMs. Discussion: We recommend better reporting of reliability data in future studies of children and AYAs with cancer. We discourage relying on historical reliability data in different samples and the reporting of only ranges of reliability coefficients for subscales. Our study suggests that significant differences in the reliability of PROMs may be associated with the PROM respondent and the version of the PROM, thus highlighting the need for further investigation.

PMID:34297613 | DOI:10.1089/jayao.2021.0072

J Sports Med Phys Fitness. 2021 Jul;61(7):953-959. doi: 10.23736/S0022-4707.20.11538-X.

ABSTRACT

BACKGROUND: Stretching is believed to decrease muscle strength. The aim of this paper was to examine the time course (immediate, and 10- and 20-minutes post-stretching) for the effects of 2, 4, and 8 minutes of static-stretching (SS) on the isometric maximum voluntary contraction force (MVCF) of hamstring muscles with a pretest-post-test experiment design.

METHODS: A total of 14 subjects with a mean age of 25 years participated in three experimental trials on three different days. Day I for static stretching for 2 minutes (SS<inf>2</inf>), day II for 4 minutes (SS<inf>4</inf>), and day III for 8 minutes (SS<inf>8</inf>). Testing was conducted before (pre), immediately after (post), and at 10- and 20-minutes post-stretching. MVCF was measured using the strain gauze as the main outcome measure.

RESULTS: MVCF increased with SS<inf>2</inf> at 0 minutes (1.31%), 10 minutes (3.4%), and 20 minutes (4.1%) postintervention. MVCF increased with SS<inf>4</inf> at 0 minutes (1.13%), 10 minutes (9.6%) and 20 minutes (7.1%) postintervention. MVCF decreased with SS<inf>8</inf> at 0 minutes (2.9%), but increased at 10 minutes (1.86%) and 20 minutes (0.99%) postintervention. All these changes were not statistically significant (P>0.05).

CONCLUSIONS: In hamstring stretching, 2, 4 and 8 minutes increased MVCF, but results were not statistically significant. Thus, 2 to 8 minutes long-duration stretching exercises could safely be performed before a strength-training session.

PMID:34296840 | DOI:10.23736/S0022-4707.20.11538-X

J Sports Med Phys Fitness. 2021 Jul;61(7):1027-1032. doi: 10.23736/S0022-4707.20.11518-4.

ABSTRACT

BACKGROUND: Stressful conditions during competitive golf putting may result in impaired performance, producing physiological changes. Nevertheless, simultaneous measurements of postural sway (PS), heart rate variability (HRV) and electrodermal activity (EDA) during a competitive golf putting have not yet been examined. This study aims at describing if changes in PS, HRV and EDA during golf putting, might affect the golfer’s performance.

METHODS: Based on EGA-handicap, 40 amateur golfers were divided in 2 groups. They competed in an indoor round of golf putting. PS, EDA, HRV and putting performance (SCORE) were recorded at basal and during competition.

RESULTS: During the putting round, a significant increase in low-frequency power (LF) and decrease in high-frequency power (HF) was found in Group A, leading to an increased LF/HF ratio. The heart rate increased significantly more in Group A than in Group B, but the stress index (SI) remained lower in this group. EDA significantly increased in both groups, with no statistical difference between groups. No statistical difference in SCORE was observed.

CONCLUSIONS: Despite the significant differences observed between the two groups, both at baseline and in response to competition, no variation of the studied variables was associated with a better putting performance.

PMID:34296843 | DOI:10.23736/S0022-4707.20.11518-4

J Magn Reson Imaging. 2021 Jul 23. doi: 10.1002/jmri.27847. Online ahead of print.

ABSTRACT

BACKGROUND: Intravoxel incoherent motion (IVIM) tensor imaging is a promising technique for diagnosis and monitoring of cardiovascular diseases. Knowledge about measurement repeatability, however, remains limited.

PURPOSE: To evaluate short-term repeatability of IVIM tensor imaging in normal in vivo human hearts.

STUDY TYPE: Prospective.

POPULATION: Ten healthy subjects without history of heart diseases.

FIELD STRENGTH/SEQUENCE: Balanced steady-state free-precession cine sequence and single-shot spin-echo echo planar IVIM tensor imaging sequence (9 b-values, 0-400 seconds/mm² and six diffusion-encoding directions) at 3.0 T.

ASSESSMENT: Subjects were scanned twice with an interval of 15 minutes, leaving the scanner between studies. The signal-to-noise ratio (SNR) was evaluated in anterior, lateral, septal, and inferior segments of the left ventricle wall. Fractional anisotropy (FA), mean diffusivity (MD), mean fraction (MF), and helix angle (HA) in the four segments were independently measured by five radiologists.

STATISTICAL TESTS: IVIM tensor indexes were compared between observers using a one-way analysis of variance or between scans using a paired t-test (normal data) or a Wilcoxon rank-sum test (non-normal data). Interobserver agreement and test-retest repeatability were assessed using the intraclass correlation coefficient (ICC), within-subject coefficient of variation (WCV), and Bland-Altman limits of agreements.

RESULTS: SNR of inferior segment was significantly lower than the other three segments, and inferior segment was therefore excluded from repeatability analysis. Interobserver repeatability was excellent for all IVIM tensor indexes (ICC: 0.886-0.972; WCV: 0.62%-4.22%). Test-retest repeatability was excellent for MD of the self-diffusion tensor (D) and MF of the perfusion fraction tensor (f_p ) (ICC: 0.803-0.888; WCV: 1.42%-9.51%) and moderate for FA and MD of the pseudo-diffusion tensor (D^* ) (ICC: 0.487-0.532; WCV: 6.98%-10.89%). FA of D and f_p and HA of D presented good test-retest repeatability (ICC: 0.732-0.788; WCV: 3.28%-8.71%).

DATA CONCLUSION: The D and f_p indexes exhibited satisfactory repeatability, but further efforts were needed to improve repeatability of D^* indexes.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

PMID:34296813 | DOI:10.1002/jmri.27847

J Magn Reson Imaging. 2021 Jul 23. doi: 10.1002/jmri.27841. Online ahead of print.

ABSTRACT

BACKGROUND: Currently, it is necessary to investigate how to combine biparametric magnetic resonance imaging (bpMRI) with various clinical parameters for the detection of clinically significant prostate cancer (csPCa).

PURPOSE: To develop a multivariate prebiopsy nomogram using clinical and bpMRI parameters for estimating the probability of csPCa.

STUDY TYPE: Retrospective, single-center study.

SUBJECTS: Two hundred and twenty-six patients who underwent targeted biopsy (TBx) for the MRI-suspected index lesion because of clinical suspicions of PCa.

FIELD STRENGTH/SEQUENCE: A 3 T MRI including turbo spin-echo T₂ -weighted and diffusion-weighted single-shot echo-planar imaging sequences.

ASSESSMENT: Prebiopsy clinical and bpMRI parameters were patient age, biopsy history (biopsy-naïve or repeated biopsy status), prostate-specific antigen density (PSAD), Prostate Imaging-Reporting and Data System version 2.1 (PI-RADSv2.1), and apparent diffusion coefficient ratio (ADCR). ADCR was defined as mean ADC of the index lesion divided by mean ADC of the contralateral prostatic region. A multivariate prebiopsy nomogram for csPCa (i.e. Gleason sum ≥7) was developed. Area under the curve (AUC) of each parameter and prebiopsy nomogram was assessed. Five-fold cross-validation was performed for robust estimation of performance of the prebiopsy nomogram.

STATISTICAL TESTS: Logistic regression, receiver-operating curve, and 5-fold cross-validation. P-value < 0.05 was considered statistically significant.

RESULTS: Proportion of csPCa was 31.9% (72/226). The AUCs of age, biopsy-naïve status, PSAD, PI-RADSv2.1, ADCR, and prebiopsy nomogram were 0.657 (95% confidence interval [CI], 0.580-0.733), 0.593 (95% CI, 0.525-0.660), 0.762 (95% CI, 0.697-0.826), 0.824 (95% CI, 0.770-0.878), 0.829 (95% CI, 0.769-0.888), and 0.906 (95% CI, 0.863-0.948), respectively: AUC of nomogram was significantly different than that of individual parameter. In the 5-fold cross-validation, the mean AUC of the prebiopsy nomogram for csPCa was 0.888 (95% CI, 0.786-0.983).

DATA CONCLUSIONS: This multivariate prebiopsy nomogram using clinical and bpMRI parameters may help estimate the probability of csPCa in patients undergoing TBx. ADCR seems to enhance the role of bpMRI in detecting csPCa.

LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

PMID:34296803 | DOI:10.1002/jmri.27841

Can J Surg. 2021 Jul 23;64(4):E407-E413. doi: 10.1503/cjs.008620.

ABSTRACT

BACKGROUND: There has been a continuing trend toward decreasing the length of hospital stay for patients undergoing total hip arthroplasty (THA). We aimed to investigate the impact of timing of discharge on gait and patient-reported outcomes early after THA.

METHODS: In this prospective observational cohort study conducted from May 2014 to November 2015, we measured gait velocity, stride length, single-limb support and single-limb support symmetry in adults aged 18-75 years before direct anterior THA, at discharge from the hospital, and 2, 6 and 12 weeks postoperatively. All procedures were performed by a single surgeon. Patients were discharged on the same day as surgery (outpatient group) or stayed at least 1 night in hospital (inpatient group). Participants also completed the Timed Up and Go test (all postoperative time points) and a series of questionnaires (Western Ontario and McMaster Universities Osteoarthritis Index [6 and 12 wk], 12-Item Short Form Health Survey [2, 6 and 12 wk], Harris Hip Score [12 wk] and a pain visual analogue scale [all postoperative time points]).

RESULTS: Thirty-six participants were enrolled in the study, of whom 16 were outpatients and 20 were inpatients. The mean pain rating at the time of discharge was lower in the outpatient group than in the inpatient group (adjusted mean difference -1.5, 95% confidence interval -3.0 to 0.0). We found no other significant differences between the groups for any gait, patient-reported or surgical outcome.

CONCLUSION: There were no statistically significant differences in gait or patient-reported outcomes after direct anterior THA between patients who stayed overnight and those who were discharged as outpatients. Patients discharged as outpatients were younger than those who stayed overnight. Our results suggest that discharging patients as an outpatient after direct anterior THA may have a similar impact on patient function and outcomes as a standard overnight stay in hospital.

PMID:34296768 | DOI:10.1503/cjs.008620

NMR Biomed. 2021 Jul 23:e4582. doi: 10.1002/nbm.4582. Online ahead of print.

ABSTRACT

Ischemic events related to carotid disease are far more strongly associated with plaque instability than stenosis. 3D high-resolution diffusion-weighted (DW) imaging can provide quantitative diffusion measurements on carotid atherosclerosis and may improve detection of vulnerable intraplaque hemorrhage (IPH). The 3D DW-stack of stars (SOS) sequence was implemented with 3D SOS acquisition combined with DW preparation. After simulation of signals created from 3D DW-SOS, phantom studies were performed. Three healthy subjects and 20 patients with carotid disease were recruited. Apparent diffusion coefficient (ADC) values were statistically analyzed on three subgroups by using a two-group comparison Wilcoxon-Mann-Whitney U test with p values less than 0.05: symptomatic versus asymptomatic; IPH-positive versus IPH-negative; and IPH-positive symptomatic versus asymptomatic plaques to determine the relationship with plaque vulnerability. ADC values calculated by 3D DW-SOS provided values similar to those calculated from other techniques. Mean ADC of symptomatic plaque was significantly lower than asymptomatic plaque (0.68 ± 0.18 vs. 0.98 ± 0.16 x 10^-3 mm² /s, p < 0.001). ADC was also significantly lower in IPH-positive versus IPH-negative plaque (0.68 ± 0.13 vs. 1.04 ± 0.11 x 10^-3 mm² /s, p < 0.001). Additionally, ADC was significantly lower in symptomatic versus asymptomatic IPH-positive plaque (0.57 ± 0.09 vs. 0.75 ± 0.11 x 10^-3 mm² /s, p < 0.001). Our results provide strong evidence that ADC measurements from 3D DW-SOS correlate with the symptomatic status of extracranial internal carotid artery plaque. Further, ADC improved discrimination of symptomatic plaque in IPH. These data suggest that diffusion characteristics may improve detection of destabilized plaque leading to elevated stroke risk.

PMID:34296793 | DOI:10.1002/nbm.4582

J Magn Reson Imaging. 2021 Jul 23. doi: 10.1002/jmri.27846. Online ahead of print.

ABSTRACT

BACKGROUND: Cholangiocarcinoma is a type of hepatobiliary tumor. For perihilar cholangiocarcinoma (pCCA), patients who experience early recurrence (ER) have a poor prognosis. Preoperative accurate prediction of postoperative ER can avoid unnecessary operation; however, prediction is challenging.

PURPOSE: To develop a novel signature based on clinical and/or MRI radiomics features of pCCA to preoperatively predict ER.

STUDY TYPE: Retrospective.

POPULATION: One hundred eighty-four patients (median age, 61.0 years; interquartile range: 53.0-66.8 years) including 115 men and 69 women.

FIELD STRENGTH/SEQUENCE: A 1.5 T; volumetric interpolated breath-hold examination (VIBE) sequence.

ASSESSMENT: The models were developed from the training set (128 patients) and validated in a separate testing set (56 patients). The contrast-enhanced arterial and portal vein phase MR images of hepatobiliary system were used for extracting radiomics features. The correlation analysis, least absolute shrinkage and selection operator (LASSO) logistic regression (LR), backward stepwise LR were mainly used for radiomics feature selection and modeling (Model^radiomic ). The univariate and multivariate backward stepwise LR were used for preoperative clinical predictors selection and modeling (Model^clinic ). The radiomics and preoperative clinical predictors were combined by multivariate LR method to construct clinic-radiomics nomogram (Model^combine ).

STATISTICAL TESTS: Chi-squared (χ² ) test or Fisher’s exact test, Mann-Whitney U-test or t-test, Delong test. Two tailed P < 0.05 was considered statistically significant.

RESULTS: Based on the comparison of area under the curves (AUC) using Delong test, Model^clinic and Model^combine had significantly better performance than Model^radiomic and tumor-node-metastasis (TNM) system in training set. In the testing set, both Model^clinic and Model^combine had significantly better performance than TNM system, whereas only Model^combine was significantly superior to Model^radiomic . However, the AUC values were not significantly different between Model^clinic and Model^combine (P = 0.156 for training set and P = 0.439 for testing set).

DATA CONCLUSION: A noninvasive model combining the MRI-based radiomics signature and clinical variables is potential to preoperatively predict ER for pCCA.

LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 4.

PMID:34296802 | DOI:10.1002/jmri.27846