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1.
2.

Purpose

The purpose of this study was to develop a SIRT2-specific substrate-type radiotracer for non-invasive PET imaging of epigenetic regulatory processes mediated by SIRT2 in normal and disease tissues.

Procedures

A library of compounds containing tert-butyloxycarbonyl-lysine-aminomethylcoumarin backbone was derivatized with fluoroalkyl chains 3–16 carbons in length. SIRT2 most efficiently cleaved the myristoyl, followed by 12-fluorododecanoic and 10-fluorodecanoic groups (Kcat/Km 716.5?±?72.8, 615.4?±?50.5, 269.5?±?52.1/s mol, respectively). Radiosynthesis of 12- [18F]fluorododecanoic aminohexanoicanilide (12-[18F]DDAHA) was achieved by nucleophilic radiofluorination of 12-iododecanoic-AHA precursor.

Results

A significantly higher accumulation of 12-[18F]DDAHA was observed in MCF-7 and MDA-MB-435 cells in vitro as compared to U87, MiaPaCa, and MCF10A, which was consistent with levels of SIRT2 expression. Initial in vivo studies using 12-[18F]DDAHA conducted in a 9L glioma-bearing rats were discouraging, due to rapid defluorination of this radiotracer upon intravenous administration, as evidenced by significant accumulation of F-18 radioactivity in the skull and other bones, which confounded the interpretation of images of radiotracer accumulation within the tumor and other regions of the brain.

Conclusions

The next generation of SIRT2-specific radiotracers resistant to systemic defluorination should be developed using alternative sites of radiofluorination on the aliphatic chain of DDAHA. A SIRT2-selective radiotracer may provide information about SIRT2 expression and activity in tumors and normal organs and tissues, which may help to better understand the roles of SIRT2 in different diseases.
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3.

Purpose

Some [68Ga]siderophores show promise in specific and sensitive imaging of infection. Here, we compare the in vitro and in vivo behaviour of selected Ga-68 and Zr-89 labelled siderophores.

Procedures

Radiolabelling was performed in HEPES or sodium acetate buffer systems. Radiochemical purity of labelled siderophores was determined using chromatography. Partition coefficients, in vitro stability and protein binding affinities were determined. Ex vivo biodistribution and animal imaging was studied in mice.

Results

Certain differences among studied siderophores were observed in labelling efficiency. Protein binding and stability tests showed highest stabilities and lowest protein binding affinities for Ga-68 and [89Zr]triacetylfusarinine C (TAFC). All studied Ga-68 and [89Zr]siderophores exhibited a similar biodistribution and pharmacokinetics in mice with the exception of [89Zr]ferrioxamine E (FOXE).

Conclusions

Zr-89 and [68Ga]siderophores showed analogous in vitro and in vivo behaviour. Tested [89Zr]siderophores could be applied for longitudinal positron emission tomography (PET) studies of fungal infections and especially TAFC for the development of novel bioconjugates.
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4.

Purpose

Noninvasive beta cell mass (BCM) quantification is a crucial tool to understand diabetes development and progression. [111In]exendin is a promising agent for in vivo beta cell imaging, but tracer testing has been hampered by the lack of well-defined rodent models.

Procedures

Biodistribution and pancreatic uptake of [111In]exendin were compared in rats and mice. In selected models, the amount of [111In]exendin accumulation in the pancreas and other organs was determined using a model of alloxan-induced beta cell loss. GLP-1R expression levels were analyzed by RT-PCR and immunohistochemistry.

Results

Namely Brown Norway rats showed beta-cell-specific tracer accumulation and favorable pancreas-to-background ratios for noninvasive BCM determination. Mice displayed receptor-mediated [111In]exendin uptake in endocrine and exocrine pancreas, in spite of very low GLP-1R expression in exocrine tissue.

Conclusions

Rats display better characteristics for in vivo BCM determination than mice and are suggested as a more adequate model for humans.
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5.

Purpose

Mitochondria are a gatekeeper of cell survival and mitochondrial function can be used to monitor cell stress. Here we validate a pathway-specific reporter gene to noninvasively image the mitochondrial function of stem cells.

Procedures

We constructed a mitochondrial sensor with the firefly luciferase (Fluc) reporter gene driven by the NQO1 enzyme promoter. The sensor was introduced in stem cells and validated in vitro and in vivo, in a mouse model of myocardial ischemia/reperfusion (IR).

Results

The sensor activity showed an inverse relationship with mitochondrial function (R 2?=??0.975, p?=?0.025) and showed specificity and sensitivity for mitochondrial dysfunction. In vivo, NQO1-Fluc activity was significantly higher in IR animals vs. controls, indicative of mitochondrial dysfunction, and was corroborated by ex vivo luminometry.

Conclusions

Reporter gene imaging allows assessment of the biology of transplanted mesenchymal stromal cells (MSCs), providing important information that can be used to improve the phenotype and survival of transplanted stem cells.
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6.

Purpose

Reactive oxygen species (ROS) are important contributors to inflammatory bowel disease (IBD); however, there are insufficient tools for their in vivo evaluation.

Procedures

To determine if a chemiluminescent ROS reporter, coelenterazine, would be a useful tool for the detection of immune cell activation, the macrophage cell line (RAW 264.7) was treated with phorbol myristate acetate (PMA). Additionally, coelenterazine was used to monitor the changes in ROS production over time in a mouse model of IBD.

Results

In vitro, coelenterazine enabled the dynamic monitoring of the RAW 264.7 cell oxidative burst. In vivo, there were early, preclinical, changes in the localization and magnitude of coelenterazine chemiluminescent foci.

Conclusions

Coelenterazine offers a high-throughput method for assessing immune cell activation in culture and provides a means for the in vivo detection and localization of ROS during IBD disease progression.
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7.

Objective

To investigate the effect of enteral Synbiotic 2000 FORTE® (a mixture of lactic acid bacteria and fibre) on the incidence of ventilator associated pneumonia (VAP) in critically ill patients.

Design

Prospective, randomised, double blind, placebo controlled trial.

Setting

Tertiary referral centre, general Adult Intensive Care Unit (ICU).

Patients and participants

259 enterally fed patients requiring mechanical ventilation for 48 h or more were enrolled.

Intervention

All patients were enterally fed as per a standard protocol and randomly assigned to receive either synbiotic 2000 FORTE® (twice a day) or a cellulose-based placebo for a maximum of 28 days.

Measurements and results

Treatment group (n = 130) was well matched with placebo group (n = 129) for age (mean 49.5 and 50 years, respectively) and APACHE II score (median 17 for both). Oropharyngeal microbial flora and colonisation rates were unaffected by synbiotics. The overall incidence of VAP was lower than anticipated (11.2%) and no statistical difference was demonstrated between groups receiving synbiotic and placebo in the incidence of VAP (9 and 13%, P = 0.42), VAP rate per 1,000 ventilator days (13 and 14.6, P = 0.91) or hospital mortality (27 and 33%, P = 0.39), respectively.

Conclusions

Enteral administration of Synbiotic 2000 FORTE® has no statistically significant impact on the incidence of VAP in critically ill patients.
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8.

Purpose

Bioluminescence imaging (BLI) is a technique with a low background noise and high sensitivity which is widely used in mice models in oncology. We aimed to assess BLI efficiency of the new luciferase NanoLuc (Nluc) for glioblastoma cell lines and tumors, including for dual reporter applications of deep brain tumors and systemic metastasis when combined with firefly luciferase (Fluc).

Procedures

U87 cells were genetically modified for constitutive production of either Nluc, Fluc, or both and assayed for luciferase activity and BLI on cell lysates, living cells, subcutaneous tumors, brain tumors, and systemic metastases.

Results

In vitro, light production by Nluc activity is higher than Fluc. In vivo, Nluc allows for tumor detection including for deep brain tumors and systemic metastases.

Conclusions

Nluc appears to be a useful tool to combine with Fluc for dual imaging in vivo using bioluminescence, allowing for the detection of distinct events in deep tissues within the same organism.
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9.

Purpose

The detection of enzyme activities and evaluation of enzyme inhibitors have been challenging with magnetic resonance imaging (MRI). To address this need, we have developed a diamagnetic, nonmetallic contrast agent and a protocol known as catalyCEST MRI that uses chemical exchange saturation transfer (CEST) to detect enzyme activity as well as enzyme inhibition.

Procedures

We synthesized a diamagnetic MRI contrast agent that has enzyme responsive and enzyme unresponsive CEST signals. We tested the ability of this agent to detect the activity of kallikrein 6 (KLK6) in biochemical solutions, in vitro and in vivo, with and without a KLK6 inhibitor.

Results

The agent detected KLK6 activity in solution and also detected KLK6 inhibition by antithrombin III. KLK6 activity was detected during in vitro studies with HCT116 colon cancer cells, relative to the detection of almost no activity in a KLK6-knockdown HCT116 cell line and HCT116 cells treated with antithrombin III inhibitor. Finally, strong enzyme activity was detected within an in vivo HCT116 tumor model, while lower enzyme activity was detected in a KLK6 knockdown tumor model and in the HCT116 tumor model treated with antithrombin III inhibitor. In all cases, comparisons of the enzyme responsive and enzyme unresponsive CEST signals were critical for the detection of enzyme activity.

Conclusions

This study has established that catalyCEST MRI with an exogenous diaCEST agent can evaluate enzyme activity and inhibition in solution, in vitro and in vivo.
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10.

Background

Phytochemicals are natural bioactive compounds that protect plants against the stress. These phytochemicals may also have other biological activities like, antibacterial activity.

Objective

The objective of this work is to study the antibacterial effect of aqueous and hydro-alcoholic extracts prepared from Thymus vulgaris, Aloysia triphylla, Pistacia lentiscus, Olea europaea leaves and Trigonella foenum-graecum seeds on some pathogenic bacteria responsible for gastroenteritis.

Result

The results obtained from the antibacterial effect showed a moderate activity against the strains studied with a diameters of inhibition zones ranging from 07.00 ± 0.8 to 16.00 ± 1.0 mm for aqueous extracts and vary between 07.00 ± 0.9 and 13.00 ± 1.0 mm for hydro-alcoholic extracts.

Conclusion

This study confirms the possibility of using these plants or components in the prevention of several diseases like, gastroenteritis.
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11.

Purpose

Evaluation of [18F]fluoromisonidazole ([18F]FMISO)-positron emission tomography (PET) imaging as a metric for evaluating early response to trastuzumab therapy with histological validation in a murine model of HER2+ breast cancer.

Procedures

Mice with BT474, HER2+ tumors, were imaged with [18F]FMISO-PET during trastuzumab therapy. Pimonidazole staining was used to confirm hypoxia from imaging.

Results

[18F]FMISO-PET indicated significant decreases in hypoxia beginning on day 3 (P?<?0.01) prior to changes in tumor size. These results were confirmed with pimonidazole staining on day 7 (P?<?0.01); additionally, there was a significant positive linear correlation between histology and PET imaging (r 2 ?=?0.85).

Conclusions

[18F]FMISO-PET is a clinically relevant modality which provides the opportunity to (1) predict response to HER2+ therapy before changes in tumor size and (2) identify decreases in hypoxia which has the potential to guide subsequent therapy.
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12.

Purpose

Dysregulation of microRNAs (miRNAs) are not only involved in the formation of malignant tumors but also in the processes of differentiation and aggressiveness. However, current methods for detecting miRNA expression have major disadvantages, such as being invasive and non-reproducible. The epithelial-mesenchymal transition (EMT) has been implicated as a pivotal event in the metastasis, stemness, and chemoresistance of malignant tumors.

Procedures

In our study, we constructed a new reporter gene, Luc2/tdT_miR200c_3TS, to examine the in vitro and in vivo expression of miR-200c, an EMT-associated miRNA. Quantitative real-time PCR was used to measure the expression levels of miR-200c and EMT-related mRNA, and luciferase assay and bioluminescence imaging were used to measure the luciferase activities in vitro and in vivo, respectively.

Results

We found that the expression level of miR-200c was negatively associated with cell migration and invasion. Luciferase activities were regulated by the differential expression levels of miR-200c and EMT process.

Conclusions

Our results demonstrate that Luc2/tdT_miR200c_3TS may be a useful tool for monitoring the expression level of miR-200c at both the cellular level and in living animals, thereby providing a potential high-throughput approach for anticancer drug screening.
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13.

Purpose

The goal of this study was to develop a plasmid-based lux bio-reporter for use to obtain in vivo images of Brucella suis vaccine strain 2 (B.suis S2) infection with high resolution and good definition.

Procedures

The pBBR-lux (pBBR1MCS-2-lxCDABE) plasmid that carries the luxCDABE operon was introduced into B. suis S2 by electroporation yielding B. suis S2-lux. The spatial and temporal transit of B. suis S2 in mice and guinea pigs was monitored by bioluminescence imaging.

Results

The plasmid pBBR-lux is stable in vivo and does not appear to impact the virulence or growth of bacteria. This sensitive luciferase reporter could represent B. suis S2 survival in real time. B. suis S2 mainly colonized the lungs, liver, spleen, and uterus in mice and guinea pigs as demonstrated by bioluminescence imaging.

Conclusion

The plasmid-based lux bioreporter strategy can be used to obtain high resolution in vivo images of B. suis S2 infection in mice and guinea pigs.
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14.

Purpose

Rapid noninvasive delineation of necrotic myocardium in ischemic regions is very critical for risk stratification and clinical decision-making but still challenging. This study aimed to evaluate the necrosis avidity of radioiodinated hypocrellins and its potential for rapidly imaging necrotic myocardium.

Procedures

The aggregation constants of four natural hypocrellins were analyzed by UV/vis spectroscopy. Then, they were radiolabeled with iodine-131 by iodogen oxidation method. Necrosis avidity of iodine-131-labeled hypocrellins was evaluated in rat models with reperfused liver infarction and muscular necrosis by gamma counting, autoradiography, and histopathology. Their pharmacokinetic properties were examined in normal rats. The potential of iodine-131-labeled hypomycin A ([131I]HD) for early imaging of necrotic myocardium was explored in rat models with reperfused myocardial infarction. Finally, the possible mechanism of necrosis avidity was investigated by in vitro DNA binding and in vivo blocking experiments.

Results

The aggregation constants of four hypocrellins were all much smaller than that of hypericin, a most studied necrosis avid agent. The radiochemical purities of the four radiotracers after purification were all greater than 95 %, and more than 90 % of tracers remained intact after incubation in rat serum for 24 h. Among the four tracers, [131I]HD exhibited the highest necrotic to viable tissue uptake ratio and the fastest blood clearance. The necrotic myocardium could be clearly visualized 4 h after injection of [131I]HD by single-photon emission computed tomography/X-ray computed tomography (SPECT/CT). DNA binding studies suggested that HD could bind to DNA through intercalation. Blocking studies demonstrated that uptake of [131I]HD in necrotic muscle could be significantly blocked by excess unlabeled HD and ethidium bromide with 67 and 60 % decline at 6 h after coinjection, respectively.

Conclusions

[131I]HD can be used to rapidly visualize necrotic myocardium. The necrosis avidity mechanism of [131I]HD may be attributed to its binding to the exposed DNA in necrotic tissues.
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15.

Purpose

This study evaluated the effectiveness of a self-managed home-based moderate intensity walking intervention on psychosocial health outcomes among breast cancer patients undergoing chemotherapy.

Methods

The randomised controlled trial compared a self-managed, home-based walking intervention to usual care alone among breast cancer patients receiving chemotherapy. Outcome measures included changes in self-report measures of anxiety, depression, fatigue, self-esteem, mood and physical activity. Fifty participants were randomised to either the intervention group (n?=?25), who received 12 weeks of moderate intensity walking, or the control group (n?=?25) mid-way through chemotherapy. Participants in the intervention group were provided with a pedometer and were asked to set goals and keep weekly diaries outlining the duration, intensity and exertion of their walking. Levels of psychosocial functioning and physical activity were assessed pre- and post-intervention in both groups.

Results

The intervention had positive effects on fatigue (F?=?5.77, p?=?0.02), self-esteem (F?=?8.93, p?≤?0.001), mood (F?=?4.73, p?=?0.03) and levels of physical activity (x 2?=?17.15, p?=?0.0011) but not anxiety (F?=?0.90, p?=?0.35) and depression (F?=?0.26, p?=?0.60) as assessed using the HADS. We found an 80 % adherence rate to completing the 12-week intervention and recording weekly logs.

Conclusion

This self-managed, home-based intervention was beneficial for improving psychosocial well-being and levels of physical activity among breast cancer patients treated with chemotherapy.

Trial registration

Current Controlled Trials ISRCTN50709297.
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16.

Objective

The modified algorithm for the non-invasive determination of cardiac output (CO) by electrical bioimpedance—electrical velocimetry (EV®)—has been reported to give reliable results in comparison with echocardiography and pulmonary arterial thermodilution (PA-TD) in patients either before or after cardiac surgery. The present study was designed to determine whether EV®-CO measurements reflect intraindividual changes in CO during cardiac surgery.

Design

Prospective, observational study.

Setting

Operating room (OR) and intensive care unit (ICU) of a university hospital.

Patients

Twenty-nine patients undergoing elective cardiac surgery.

Interventions

None.

Measurements

CO was determined simultaneously by PA-TD and EV® after induction of anesthesia (t1) and 4.9?±?3.5?h after ICU admission (t2).

Results

TD-CO was 3.9?±?1.4 and 5.4?±?1.1 l/min at t1 and t2 (?p?®-CO was 4.3?±?1.1 and 4.9?±?1.5 l/min at t1 and t2 (?p?=?0.013). Bland–Altman analysis showed a bias of ?0.4 l/min and 0.4 l/min and a precision of 3.2 and 3.6 l/min (34.3% and 67.4%) at t1 and t2, respectively. Analysis of the individual pre- to postoperative changes in CO with both methods revealed bidirectional changes in n?=?12 patients and unidirectional changes with a difference greater than 50% and less than 50% in n?=?9 and n?=?8 patients, respectively.

Conclusions

The disagreement between PA-TD and EV®-CO measurements after anesthesia induction and after ICU admission, as well as the fact that thoracic bioimpedance did not adequately reflect pre- to postoperative changes in CO, questions the reliability of EV®-CO measurements in cardiac surgery patients and contrasts sharply with previous studies.
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17.

Purpose

The accurate detection of lymph node metastases in prostate cancer patients is important to direct treatment decisions. Our goal was to develop an intraoperative imaging approach to distinguish normal from metastasized lymph nodes. We aimed at developing and testing gold-silica surface-enhanced resonance Raman spectroscopy (SERRS) nanoparticles that demonstrate high uptake within normal lymphatic tissue and negligible uptake in areas of metastatic replacement.

Procedures

We evaluated the ability of SERRS nanoparticles to delineate lymph node metastases in an orthotopic prostate cancer mouse model using PC-3 cells transduced with mCherry fluorescent protein. Tumor-bearing mice (n?=?6) and non-tumor-bearing control animals (n?=?4) were injected intravenously with 30 fmol/g SERRS nanoparticles. After 16–18 h, the retroperitoneal lymph nodes were scanned in situ and ex vivo with a Raman imaging system and a handheld Raman scanner and data corroborated with fluorescence imaging for mCherry protein expression and histology.

Results

The SERRS nanoparticles demonstrated avid homing to normal lymph nodes, but not to metastasized lymph nodes. In cases where lymph nodes were partially infiltrated by tumor cells, the SERRS signal correctly identified, with sub-millimeter precision, healthy from metastasized components.

Conclusions

This study serves as a first proof-of-principle that SERRS nanoparticles enable high precision and rapid intraoperative discrimination between normal and metastasized lymph nodes.
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18.

Purpose

The aim of this study is to evaluate the impact of different scatter correction strategies on quantification of high-resolution research tomograph (HRRT) data for three tracers covering a wide range in kinetic profiles.

Procedures

Healthy subjects received dynamic HRRT scans using either (R)-[11C]verapamil (n?=?5), [11C]raclopride (n?=?5) or [11C]flumazenil (n?=?5). To reduce the effects of patient motion on scatter scaling factors, a margin in the attenuation correction factor (ACF) sinogram was applied prior to 2D or 3D single scatter simulation (SSS).

Results

Some (R)-[11C]verapamil studies showed prominent artefacts that disappeared with an ACF-margin of 10 mm or more. Use of 3D SSS for (R)-[11C]verapamil showed a statistically significant increase in volume of distribution compared with 2D SSS (p?<?0.05), but not for [11C]raclopride and [11C]flumazenil studies (p?>?0.05).

Conclusions

When there is a patient motion-induced mismatch between transmission and emission scans, applying an ACF-margin resulted in more reliable scatter scaling factors but did not change (and/or deteriorate) quantification.
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19.

Purpose

Noninvasive imaging of tau and amyloid-β pathologies would facilitate diagnosis of Alzheimer’s disease (AD). Recently, we have developed [18F]THK-5105 for selective detection of tau pathology by positron emission tomography (PET). The purpose of this study was to clarify biological properties of optically pure [18F]THK-5105 enantiomers.

Procedures

Binding for tau aggregates in AD brain section was evaluated by autoradiography (ARG). In vitro binding assays were performed to evaluate the binding properties of enantiomers for AD brain homogenates. The pharmacokinetics in the normal mouse brains was assessed by ex vivo biodistribution assay

Results

The ARG of enantiomers showed the high accumulation of radioactivity corresponding to the distribution of tau deposits. In vitro binding assays revealed that (S)-[18F]THK-5105 has slower dissociation from tau than (R)-[18F]THK-5105. Biodistribution assays indicated that (S)-[18F]THK-5105 eliminated faster from the mouse brains and blood compared with (R)-[18F]THK-5105.

Conclusion

(S)-[18F]THK-5105 could be more suitable than (R)-enantiomer for a tau imaging agent.
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20.

Purpose

This study aimed to evaluate the efficacy of supportive-expressive group (SEG) therapy and body-mind-spirit (BMS) intervention on emotional suppression and psychological distress in Chinese breast cancer patients.

Methods

This three-arm randomized controlled trial assigned 157 non-metastatic breast cancer patients to BMS, SEG, or social support control group. SEG focused on emotional expression and group support, whereas BMS emphasized relaxation and self-care. All groups received 2-h weekly sessions for 8 weeks. The participants completed measurements on emotional suppression, perceived stress, anxiety, and depression at baseline and three follow-up assessments in 1 year.

Results

Using latent growth modeling, overall group difference was found for emotional suppression (χ 2(2)?=?8.88, p?=?0.012), marginally for perceived stress (χ 2(2)?=?5.70, p?=?0.058), but not for anxiety and depression (χ 2(2)?=?0.19–0.94, p?>?0.05). Post-hoc analyses revealed a significant and moderate reduction (Cohen d?=?0.55, p?=?0.007) in emotional suppression in SEG compared to control group, whereas BMS resulted in a marginally significant and moderate fall (d?=?0.46, p?=?0.024) in perceived stress. Neither SEG nor BMS significantly improved anxiety and depression (d?<?0.20, p?>?0.05).

Conclusions

The present results did not demonstrate overall effectiveness for either BMS or SEG therapy in the present sample of Chinese non-metastatic breast cancer patients. The participants appear to derive only modest benefits in terms of their psychological well-being from either intervention.
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