Association between physical activity and risk of premenstrual syndrome among female college students: a systematic review and meta-analysis.

BACKGROUND: This study aimed to analyze the relationship between physical activity and the risk of premenstrual syndrome among college students. METHODS: Eligible studies were searched from the PubMed, Web of Science, and Embase databases. The link between physical activity and the risk of premenstrual syndrome was evaluated using odds ratio (OR) and 95% confidence interval (CI). The heterogeneity of the included studies was tested and their sources were explored by subgroup analysis. A sensitivity analysis was performed to assess the effect of a single study on the pooled results. The included studies were evaluated for publication bias. Five moderate-quality studies were included in this meta-analysis. RESULTS: Physical activity levels were negatively associated with risk of premenstrual syndrome among college students (OR [95%CI] = 1.46 [1.09, 1.96], P = .011). The pooled results were not influenced after being stratified by the study region and whether multi-factor correction was performed or not. Publication bias was not observed in the included studies. CONCLUSION: A high level of physical activity is dramatically associated with a reduced risk of premenstrual syndrome among female college students.

Association between physical activity levels and anxiety or depression among college students in China during the COVID-19 pandemic: A meta-analysis.

BACKGROUND: This meta-analysis aimed to investigate the links between the level of physical activity and the risk of anxiety or depression among college students in China during the Coronavirus Disease 2019 pandemic. METHODS: Eligible studies were searched from the PubMed, Embase, and Web of Science databases. The associations between them were assessed with odd ratio (OR) and 95% confidence interval (CI). The heterogeneity of the included studies was evaluated and subgroup analysis was performed. Sensitivity analysis was executed using leave-one-out method. Publication bias of included studies was evaluated. Ten studies with moderate quality were included. RESULTS: Physical activity levels of college students were associated with reduced risk of depression (OR [95%CI] = 0.69 [0.58, 0.82], P < .001) and anxiety (OR [95%CI] = 0.71 [0.62, 0.80], P < .001). The measurement scale of depression or anxiety and whether multi-factor correction was performed or not did not influence the pooled results. The pooled results of depression and anxiety were stable and were not significantly influenced by a single study. No publication bias was observed in the included studies reporting depression and anxiety. CONCLUSION: The physical activity level of college students is negatively correlated with anxiety and depression in China during the pandemic. During the Coronavirus Disease 2019 pandemic, it is necessary to strengthen the construction of university physical education courses. As an organized form of physical activity, physical education classes are a necessary and effective way to increase physical activity among college students.

Exercise interventions on body composition and quality of life of overweight/obese breast cancer survivors: a meta-analysis.

BACKGROUND: This meta-analysis aimed to assess the effects of exercise interventions on body composition and quality of life in overweight/obese breast cancer survivors. METHODS: Eligible randomized controlled trials (RCTs) were searched from the Cochrane Library, PubMed, and Embase databases and assessed using the Cochrane Collaboration's assessing risk tool. The effect size was pooled as weighted mean difference (WMD) for body composition variables (i.e., body mass index [BMI], body fat, body weight, fat mass, lean mass, bone mineral density) and quality of life (i.e., physical health and mental health), and the confidence interval (CI) was set as 95%. Since heterogeneity existed, subgroup analysis was conducted to detect the source of heterogeneity. RESULTS: Eight articles from six RCTs containing 548 overweight/obese breast cancer survivors (BMI ≥ 25 kg/m2) were included and analyzed. Compared to routine care, exercise intervention significantly decreased the body mass index [WMD (95% CI) = -1.37 (-2.50, -0.23) kg/m2] and body fat [WMD (95% CI) = -3.80 (-6.59, -1.01) %] of overweight/obese breast cancer survivors. Exercise intervention showed a tendency to increase physical health [WMD (95% CI) = 2.65 (-10.19, 15.48)] and mental health [WMD (95%CI) = 1.38 (-4.18, 6.95)], but no statistical significance was observed. A subgroup analysis showed the duration of intervention was a source of heterogeneity on body composition. In the 16-week subgroup, exercise intervention decreased fat mass and BMI while increased lean mass and bone mineral density. The 52-week exercise intervention was effective in increasing lean mass. A significant exercise intervention effect on reducing body fat was only detected in the 12-week subgroup. CONCLUSION: Exercise intervention significantly decreased the body mass index and body fat of overweight/obese breast cancer survivors. The benefits of exercise interventions for overweight/obese breast cancer survivors need more evidence from high-quality RCTs with large sample sizes.

Association between appendicular lean mass and chronic obstructive pulmonary disease: epidemiological cross-sectional study and bidirectional Mendelian randomization analysis.

Background: The association of BMI with COPD, and sarcopenia in COPD have been both confirmed by several studies, but research on the relationship and causality of body lean mass and the risk of chronic obstructive pulmonary disease (COPD) remains to be discovered. The purpose of this study was to explore the association between lean mass and COPD risk as well as to further examine the causal relationship in the findings. Methods: Three thousand four hundred fifty-nine participants from NHANES 2013-2018 were included in the epidemiological cross-sectional study to assess the association between relative lean mass and COPD by restricted spline analysis (RCS) and weighted multiple logistic regression. Furthermore, to verify the causality between lean mass and COPD, a two-sample Mendelian randomization (MR) with inverse variance weighting (IVW) method was used to analyze GWAS data from European ancestry. Genetic data from the United Kindom Biobank for appendicular lean mass (450,243 cases) and lung function (FEV1/FVC) (400,102 cases) together with the FinnGen platform for COPD (6,915 cases and 186,723 controls) were used for MR. Results: Weighted multiple logistic regression showed a significant correlation between relative appendicular lean mass and COPD after adjusting for confounders (OR = 0.985, 95% CI: 0.975-0.995). Compared to the lower mass (155.3-254.7) g/kg, the high mass (317.0-408.5) g/kg of appendicular lean apparently decreases the risk of COPD (OR = 0.214, 95% CI: 0.060-0.767). Besides, in the analysis of MR, there was a forward causality between appendicular lean mass and COPD (IVW: OR = 0.803; 95%CI: 0.680-0.949; p = 0.01), with a weak trend of causality to lung function. Conclusion: Our study not only found an inverse association between appendicular lean mass and COPD but also supported a unidirectional causality. This provided possible evidence for further identification of people at risk for COPD and prevention of COPD based on limb muscle exercise and nutritional supplementation to maintain skeletal muscle mass.

Effects of cognitive motor dual-task training on stroke patients: A RCT-based meta-analysis.

Based on a randomized controlled trial (RCT), this meta-analysis aimed to comprehensively analyze the effects of cognitive motor dual-task training (CMDT) on stroke patients. The electronic databases PubMed, Embase, and the Cochrane Library were searched for papers on the influence of CMDT on stroke patients. Weighted mean difference (WMD) and 95% confidence interval (95% CI) were used as effect sizes. Cochran's Q and I2 tests were performed for heterogeneity. Thirteen articles involving 326 patients were included in the study. The meta-analysis showed that CMDT significantly improved the walking balance of patients with stroke (P = 0.01). In addition, CMDT significantly improved the gait ability of patients with stroke (P < 0.0001). Furthermore, CMDT had a significant effect on the improvement of upper limb ability in patients with stroke (P < 0.00001). CMDT could significantly improve balance ability, gait, and upper limb function in patients with chronic stroke, which is worthy of clinical promotion.

Circulating Exosomal MicroRNA Profiles Associated with Acute Soft Tissue Injury.

OBJECTIVE: This study aimed to characterize the circulating exosomal microRNA (miRNA) profiles associated with acute soft tissue injury. MATERIALS AND METHODS: In this experimental study, a total of 12 rats were randomly divided into control group and model group (n=6 for each group). The rats in the model group were used to establish an acute soft tissue injury following the mechanical injury of the leg. The exosomes from the peripheral blood of all the rats were isolated and then characterized by Nanosight NS300 particle size analyser (NTA), transmission electron microscopy (TEM) and western blot. Next, the exosomal miRNAs in the control and model groups were sequenced, and the differentially expressed miRNAs (DE-miRNAs) were identified using the DESeq algorithm. Functional analyses were performed using Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway databases. Finally, quantitative reverse-transcription polymersa chain reaction (qRT-PCR) was used to verify the expression of the DE-miRNAs. RESULTS: TEM, NTA and western blot results showed that the exosomes were approximately 100 nm in size and exhibited cup-shaped morphology. A total of 628 miRNAs were obtained by sequencing. After that, 28 DE miRNAs (DEmiRNAs) were identified, including seven down-regulated miRNAs and 21 up-regulated miRNAs. These DE-miRNAs were linked to 7539 target genes with GO. Also, KEGG analyses demonstrated that these genes were enriched for phosphorylation, VEGF signaling pathway, and MAPK signaling pathway. Additionally, the consistency rate between the qRT-PCR and sequencing results was 83.33%, which showed a high relative reliability of the sequencing results. CONCLUSION: These findings suggest that these 28 exosomal miRNAs may be involved in the regulation of acute soft tissue injury, by one of critical biological processes (BP), phosphorylation. The findings provide valuable clues by utilizing exosomes as therapeutic targets for the effective treatment of acute soft tissue injury.

Exosomes isolated from the miR-215-modified bone marrow mesenchymal stem cells protect H2O2-induced rat myoblasts via the miR-215/FABP3 pathway.

This study aimed to investigate the potential effects of miR-215, with exosomes as carriers, against skeletal muscle injury. Exosomes were isolated from rat bone marrow mesenchymal stem cells (rBMSCs) or rBMSCs overexpressing miR-215. Subsequently, rat myoblasts (L6) were treated with different exosomes and mimics, then exposed to H2O2. Cell viability and apoptosis were determined using the Cell Counting Kit-8 and Annexin V-FITC cell apoptosis assay kits, respectively. Reverse-transcriptase quantitative PCR (RT-qPCR) was used to examine the expression of related genes. Transmission electron microscopy, Nanosight, and western blotting showed that the exosomes were successfully isolated. PKH67 staining revealed that both exosomes and miR-215-modified exosomes were taken up by L6 cells. FABP3 was found to be the target gene of miR-215 via a dual luciferase reporter gene assay. In the L6 cells treated with H2O2, cell viability was significantly inhibited, whereas apoptosis significantly increased (P < 0.05). Exosomes significantly enhanced the viability of H2O2-induced cells and inhibited their apoptosis (P < 0.05). In addition, RT-qPCR showed that in the H2O2-induced L6 cells, FABP3, CDKN1A, and TP53 were significantly upregulated, while CCNB1 was significantly downregulated (P < 0.05). However, their expression levels were significantly reversed after treatment with miR-215-modified exosomes (P < 0.05). These findings indicate that the miR-215-modified exosomes may exert protective effects against skeletal muscle injury through the miR-215/FABP3 pathway and regulate the expression of CDKN1A, CCNB1, and TP53.

Effects of physical activity on sleep problems in breast cancer survivors: a meta-analysis.

PURPOSE: To investigate the possible role of physical activity (PA) on sleep disturbance in breast cancer patients. METHODS: Literature in PubMed, Embase, and the Cochrane Library was systematically searched until January 30, 2020. Randomized controlled trials that focused on the role of PA interventions on sleep disturbance were selected. The main outcome measures included the global Pittsburgh Sleep Quality Index (PSQI) score and PSQI subscales. Subgroup analysis was performed based on the study area and intervention time. The stability and authenticity of the results were measured by sensitivity analysis and publication bias analysis, respectively. RESULTS: Six articles were included in this meta-analysis. There were no significant differences in global PSQI scores between the PA intervention group and the usual care group (P = 0.057). As for PSQI subscales, PA intervention could improve sleep quality (weighted mean difference = 0.22; 95% confidence interval 0.04-0.40; P = 0.018). There were no significant differences in sleep duration, sleep medication, sleep latency, habitual sleep efficiency, and daytime dysfunction between the two groups (all P > 0.05). CONCLUSION: PA serves as an effective intervention to improve sleep quality.

Mesenchymal stem cells derived-exosomes as a new therapeutic strategy for acute soft tissue injury.

The study aimed to investigate the role of exosomes derived from rat bone marrow mesenchymal stem cells (rBMSCs) in acute soft tissue injury and its related mechanisms. Exosomes were isolated from rBMSCs and characterized by Nanosight NS300 particle size analyser (NTA), transmission electron microscopy (TEM), and western blot. Twenty four rats were randomly divided into four groups (n = 6): control group, strike group, rBMSCs group, and rBMSCs-exo group. Haematoxylin-eosin (HE) staining was used to observe the morphology. Real-time quantification PCR (RT-qPCR) and western blot were used to analyse the expression of IL-1A, IL-12A, COL11A1, COL4A4, and Wnt4. NTA, TEM and western blot results showed that exosomes isolated from rBMSCs were cup-shaped morphology with a size of about 100 nm. HE staining showed that there was severe soft tissue inflammation in strike group, and the symptoms were alleviated after rBMSCs and rBMSCs-exo treatment. RT-qPCR and western blot indicated that in the strike group, the expression levels of IL-1A and IL-12A were significantly increased, and their expressions were decreased markedly by exosomes treatment. In addition, after treatment, the expression levels of COL11A1 and Wnt4 were up-regulated, while the expression of COL4A4 was down-regulated. Exosomes isolated from rBMSCs could improve acute soft tissue injury, and may be used as a new therapeutic strategy acute soft tissue injury. SIGNIFICANCE OF THE STUDY: Acute soft tissue injury is a common clinical exercise injury, which has a significant impact on people's health and work ability. Exosomes have been attracting increasing attention as a media of cell-to-cell communication. This study showed that exosomes isolated from rBMSCs could improve acute soft tissue injury by inhibiting inflammatory response, regulating the levels of COL11A1 and COL4A4, and up-regulating the expression of Wnt4. These will provide a new therapy strategy of acute soft tissue injury, and improve our understanding of the occurrence and development in acute soft tissue injury.

The Correlation Between Vitamin D Receptor (VDR) Gene Polymorphisms and Autism: A Meta-analysis.

Vitamin D receptor (VDR) polymorphisms are risk factors for autism. We performed a systematic meta-analysis to explore the relationship between VDR gene polymorphisms and autism. A literature review of articles from Pubmed, Embase, the Cochrane Library, and Springer was conducted up to January 28, 2019. The association between SNPs and autism was calculated using pooled odd ratios (ORs) and 95% confidence intervals (CIs). Additionally, tests for heterogeneity, publication bias, and sensitivity were conducted. Six eligible studies with a total of 2001 participants (1045 cases and 956 controls) were included. Meta-analysis indicated that the "C" allele of the rs731236 gene, including C vs. T (OR = 1.3254, 95% CI = 1.0897-1.6122), CC vs. TT (OR = 2.0871, 95% CI = 1.3395-3.2519), and CC vs. TT + CT (OR = 1.9610, 95% CI = 1.2985-2.9615), might be a risk factor for autism. Moreover, the "G" allele of rs7975232 (G vs. T: OR = 0.8228, 95% CI = 0.6814-0.9934) was associated with a protective effect against the development of autism. No significant differences were found in the allele frequencies of rs11568820, rs1544410, and rs2228570 in the cases and controls. This meta-analysis revealed that both VDR rs731236 and rs7975232 were significantly associated with autism, whereas VDR rs11568820, rs1544410, and rs2228570 might not be correlated with the incidence of autism.

A combination of the modified Stoppa approach and the iliac fossa approach in treating compound acetabular fractures by using an anterior ilioischial plate.

Most compound acetabular fractures involving both the anterior and posterior columns are caused by high-energy injuries. Patients with compound acetabular fractures are often in critical or poor condition and cannot tolerate major surgery. This study aims to investigate the effectiveness of an ilioischial plate in treating compound acetabular fractures. A consecutive series of 40 patients with complex acetabular fractures were surgically treated and retrospectively reviewed. A modified Stoppa approach in combination with an iliac fossa approach was used. In all of the cases, the anterior column was stabilized with reconstruction plates for the iliac wing and along the iliopectineal line to the pubis. The posterior column was fixed either with the newly developed ilioischial plate running from the ilium to the ischial ramus or with standard fixation techniques. These included either conventional posterior column screws or quadrilateral plate fixation. Patients were divided into an experimental group (ilioischial plate for posterior column fixation) and a control group (standard fixation techniques). In both groups, we found that 90% of all reductions were good to excellent. According to the modified Merle Aubigne and Postel scoring system, the percentage of good to excellent was 85% in the experimental group as compared to 80% in the control group. Compared with the control group, physical function (PF), role physical (RP) and social function (SF) were significantly better in the experimental group (P<0.05). Fracture healing was achieved in all patients. By using the modified Stoppa approach combined with the iliac fossa approach, the ilioischial plate can be directly fixed to the posterior column and the ilium to stabilize the posterior column in patients with complex acetabular fractures.

Effect of conventional medical treatment plus Qigong exercise on type 2 diabetes mellitus in Chinese patients: A Meta-analysis.

OBJECTIVE: To systematically evaluate the effect of conventional medical treatment plus Qigong exercise on type 2 diabetes mellitus (T2DM) in Chinese patients. METHODS: A literature search was conducted in PubMed, Medline, Embase, China National Knowledge Infrastructure Database, Wanfang and China Science and Technology Journal Database until on January 2017. In this Meta-analysis, enrolled were the studies, including experimental group (with conventional medical treatment plus Qigong therapy) and control group (with conventional medical treatment plus diet control or other exercises). Then, the standardized mean differences (SMDs) of fasting blood-glucose (FBG), 2-hplasmaglucose (2hPG), hemoglobinAlc (HbAlc), triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL) and low density lipoprotein (LDL), as well as their 95% confidence interval (CIs) were calculated to evaluate the effect of Qigong on patients with T2DM by RevMan 5.2 and Stata 11.0 software. RESULTS: Totally 834 cases of T2DM from 11 studies were included in this review. The pooled SMDs with its 95% CIs of FBG, 2hPG, HbAlc, TG, TC, HDL and LDL were -0.70 (-0.93, -0.47), -0.66 (-1.11, -0.21), -0.73 (-0.96, -0.50), -1.05 (-1.67, -0.43), -0.42 (-1.12, 0.28), 0.69 (0.19, 1.19), and -0.26 (-0.69, 0.18), respectively. The pooled data showed significantly difference between Qigong and the levels of FBG, 2hPG, HbA1c, TG, and HDL in patients with T2DM (P < 0.05). CONCLUSION: Combining with conventional medical treatment, Qigong exercise might have significant effect on T2DM in Chinese patients.

Exercise Affects Cardiopulmonary Function in Patients with Chronic Kidney Disease: A Meta-Analysis.

This study aimed to comprehensively assess the effects of exercise on cardiopulmonary function indices in patients with chronic kidney disease (CKD). A literature review was performed by searching literatures in PubMed and Embase before June 2016. Studies were selected based on predefined inclusion and exclusion criteria, followed by data extraction and a quality assessment of the included studies using the Cochrane Collaboration's tool. Correlations between exercise and cardiopulmonary function indices [pulse wave velocity, respiratory exchange ratio, and peak oxygen uptake (VO2 peak)] were then evaluated using mean differences and 95% confidence intervals. All meta-analyses were conducted using R 3.12 software. Finally, five eligible studies involving 179 CKD patients were included. After intervention, a heterogeneity test showed that the VO2 peak values of the treatment group were greater than those of the control group, whereas no significant differences were found for the other indices. However, a sensitivity analysis showed inconsistent results both before and after intervention. Thus, we concluded that exercise might play an important role in improving the VO2 peak values in CKD patients. Additional studies are needed to verify this conclusion.

The Effect of Three Different Meditation Exercises on Hypertension: A Network Meta-Analysis.

We aimed to use the pairwise and network meta-analysis to estimate the effects of different meditation exercises on the control of systolic blood pressure (SBP) and diastolic blood pressure (DBP). Randomized controlled trials (RCTs) were retrieved from PubMed and Embase up to June 2016, which are published in English and reported on meditation exercise for hypertensive patients. Risks of bias assessment of the included studies were assessed by Cochrane Collaboration Recommendations and network meta-analysis was performed by ADDIS. Mean difference (MD) and its 95% confidence interval (CI) were used as the effect size. A number of 19 RCTs were included in this study. Results of pairwise comparisons indicated that meditation exercise could significantly decrease the SBP and DBP, compared with other interventions (MD = -7.10, 95% CI: -10.82 to -3.39; MD = -4.02, 95% CI: -6.12 to -1.92). With good consistence and convergence, network meta-analysis showed that there were no significant differences between meditation and other interventions on SBP. For DBP, Qigong was significantly lower than "no intervention" (MD = -11.73, 95% CI: -19.85 to -3.69). Qigong may be the optimal exercise way in lowering SBP and DBP of hypertensive patients, but a detailed long-term clinical research should be needed in the future.

Ultrasound-Induced Magnetic Imaging of Tumors Targeted by Biofunctional Magnetic Nanoparticles.

Biofunctional magnetic nanoparticles (MNPs) have been widely applied in biomedical engineering. MNPs are used as a contrast medium in magnetic imaging. Current methods of magnetic imaging, such as magnetic particle imaging and magnetic relaxometry, use small amounts of MNPs at target points far from the surface of the patient's body; these methods always consume considerable power to produce magnetic fields of high uniformity or gradient excitations. Some drawbacks, such as a limited imaging region, imaging system shielding, and complex algorithms based on assumptions of MNP properties or environmental factors, also limit the application of MNP methods in clinics. Therefore, this work proposes an interdisciplinary methodology of ultrasound-induced magnetic imaging that lacks these drawbacks. In the proposed imaging method, magnet sets were designed with uniform magnetic fields to magnetize MNPs. Besides, magnetized MNPs are subjected to ultrasound vibrations; the motion of the MNPs induces weak induction voltages at the imaging pickup coils. The highly sensitive scanning superconducting quantum interference device biosusceptometry with three sets of ultrasound focus chips was developed to construct magnetic tomography at three depths. A phantom test showed favorable consistency between the visual photos and the magnetic images of alpha-fetoprotein antibody (anti-AFP) MNP distribution on gauzes. In animal tests, rats with liver tumors were imaged at the pre-injection and post-injection of anti-AFP MNPs. The consistent results of magnetic images and ultrasound images implied that the proposed method has high clinical potential.

[Effect of pregnant rat adipose-derived stem cells on repair of acute liver injury].

Objective: To assess the effect of pregnant rat adipose-derived stem cells (ADSCs) on repair of acute liver injury. Methods: ADSCs were isolated from 18-week pregnant Sprague Dawley rats and were identified by flow cytometry. Twenty Sprague Dawley rats were randomly divided into groups A, B, C, and D ( n=5); rats in group A were not treated as normal controls; rats in groups B, C, and D were injected intraperitoneally with CCl 4 to establish the acute liver injury model. At 2 hours after modeling, DPBS, 0.1 mL normal rat ADSCs (2×10 6cells/mL), and pregnant rat ADSCs (2×10 6cells/mL) were injected into the spleen in groups A, C, and D respectively; rats in group B was not treated. After 7 days, total bilirubin (TBIL), alanine aminotransferase (ALT), aspartic acid transaminase (AST), albumin (ALB), and total protein (TP) in serum were measured. The liver tissue sections were stained with HE. The expressions of Ki67, alpha-fetoprotein (AFP), and ALB were measured by immunohistochemistry. Results: The serum levels of TBIL, ALT, and AST in group B were significantly higher than those in groups A, C, and D ( P<0.05), but ALB and TP were significantly lower than those in groups A, C, and D ( P<0.05). The levels of TBIL, ALT, and AST were significantly higher in groups C and D than group A, and in group C than group D ( P<0.05). There was no significant difference in serum levels of ALB among groups A, C, and D ( P>0.05). The serum level of TP in groups C and D was significantly lower than that in group A ( P<0.05), but no significant difference was found between group C and group D ( P>0.05). HE staining showed that the liver tissue of group A had clear structure; the cells arranged neatly with uniform size. The hepatocytes in group B showed obvious edema, disorderly arrangement, dot necrosis in liver lobules, and diffuse infiltration of inflammatory cells. In groups C and D, the inflammation and hepatocellular necrosis were obviously reduced when compared with group B, and the number of vacuoles caused by dilation of mitochondria and rough endoplasmic reticulum was decreased; especially in group D, improvement of liver injury was more effective. The Ki67 positive cell rate was significantly higher in groups C and D than groups A and B ( P<0.05), in group B than group A ( P<0.05), and in group D than group C ( P<0.05). There was no expression of AFP in groups A and B, but positive expression was observed in groups C and D, and AFP positive cell rate of group D was significantly higher than that of group C ( t=3.006, P=0.017). ALB expression was significantly higher in groups C and D than groups A and B ( P<0.05), and in group D than group C ( P<0.05). Conclusion: Pregnant rat ADSCs could promote repair of liver injury induced by CCl 4.

Rapid and quantitative discrimination of tumour cells on tissue slices.

After a needle biopsy, immunohistochemistry is generally used to stain tissue slices for clinically confirming tumours. Currently, tissue slices are immersed in a bioprobe-linked fluorescent reagent for several minutes, washed to remove the unbound reagent, and then observed using a fluorescence microscope. However, the observation must be performed by experienced pathologists, and producing a qualitative analysis is time consuming. Therefore, this study proposes a novel scanning superconducting quantum interference device biosusceptometry (SSB) method for avoiding these drawbacks. First, stain reagents were synthesised for the dual modalities of fluorescent and magnetic imaging by combining iron-oxide magnetic nanoparticles and the currently used fluorescent reagent. The reagent for the proposed approach was stained using the same procedure as that for the current fluorescent reagent, and tissue slices were rapidly imaged using the developed SSB for obtaining coregistered optical and magnetic images. Analysing the total intensity of magnetic spots in SSB images enables quantitatively determining the tumour cells of tissue slices. To confirm the magnetic imaging results, a traditional observation methodology entailing the use of a fluorescence microscope was also performed as the gold standard. This study determined high consistency between the fluorescent and magnetic spots in different regions of the tissue slices, demonstrating the feasibility of the proposed approach, which will benefit future clinical pathology.

Magnetic Clustering Effect during the Association of Biofunctionalized Magnetic Nanoparticles with Biomarkers.

We report herein an investigation into dynamic magnetic clustering that occurs during immunoassays as biofunctionalized magnetic nanoparticles (BMNs) become associated with biotargets. We measure the dynamic effective relaxation time τeff(t) and use scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to investigate the C-reactive protein (CRP) as it associates with the BMN Fe3O4-antiCRP to form the magnetic cluster Fe3O4-antiCRP-CRP. The results indicate that τeff(t) increases with increasing association time. In addition, the ration Δτeff/τ0 as a function of CRP concentration follows a characteristic logistic function, which provides a basis for estimating the quantity of biomolecules with a detection sensitivity close to 0.1 ppm. After the association, SEM and TEM images show that CRP and Fe3O4-antiCRP conjugate to form Fe3O4-antiCRP-CRP clusters hundreds of nanometers in size. The SEM and TEM images provide direct evidence of the formation of magnetic clustering.

Using bio-functionalized magnetic nanoparticles and dynamic nuclear magnetic resonance to characterize the time-dependent spin-spin relaxation time for sensitive bio-detection.

In this work, we report the use of bio-functionalized magnetic nanoparticles (BMNs) and dynamic magnetic resonance (DMR) to characterize the time-dependent spin-spin relaxation time for sensitive bio-detection. The biomarkers are the human C-reactive protein (CRP) while the BMNs are the anti-CRP bound onto dextran-coated Fe3O4 particles labeled as Fe3O4-antiCRP. It was found the time-dependent spin-spin relaxation time, T2, of protons decreases as time evolves. Additionally, the ΔT2 of of protons in BMNs increases as the concentration of CRP increases. We attribute these to the formation of the magnetic clusters that deteriorate the field homogeneity of nearby protons. A sensitivity better than 0.1 µg/mL for assaying CRP is achieved, which is much higher than that required by the clinical criteria (0.5 mg/dL). The present MR-detection platform shows promise for further use in detecting tumors, viruses, and proteins.