A Narrow Straight Microchannel Array for Analysis of Transiting Speed of Floating Cancer Cells

Investigating floating cells along a narrow microchannel (e.g., a blood vessel) for their transiting speeds and the corresponding roles of cell physical properties can deepen our understanding of circulating tumor cells (CTCs) metastasis via blood vessels. Many existing studies focus on the cell transiting process in blood vessel-like microchannels; further analytical studies are desired to summarize behaviors of the floating cell movement under different conditions. In this work, we perform a theoretical analysis to establish a relation between the transiting speed and key cell physical properties. We also conduct computational fluid dynamics simulation and microfluidic experiments to verify the theoretical model. This work reveals key cell physical properties and the channel configurations determining the transiting speed. The reported model can be applied to other works with various dimensions of microchannels as a more general way to evaluate the cancer cell metastasis ability with microfluidics.

CT and MRI features of extraocular muscle granular cell tumour: preliminary experience in eight cases

AIM

To characterise the computed tomography (CT) and magnetic resonance imaging (MRI) features, in particular the functional MRI characteristics, of extraocular muscle granular cell tumours (GCTs).

MATERIALS AND METHODS

The CT (n=6) and MRI (n=8) features of eight extraocular muscle GCTs cofirmed at histopathology were analysed retrospectively. The imaging findings were evaluated with emphasis on the location, size, margin, shape, extent, bony change, internal architecture, enhancement pattern, and extent of lesions. Based on diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI, the apparent diffusion coefficient (ADC) value of six lesions and time-intensity curve (TIC) of one lesion were reviewed.

RESULTS

Immunohistochemistry revealed strong positivity for S-100 protein and a low Ki-67 index (2-5%) in all cases. Most of the lesions (7/8) were confined to the muscle belly with an ovoid shape. All of the tumours were isodense to cerebral grey matter and showed homogeneously mild enhancement on CT images. All lesions were hypointense to cerebral grey matter on T2-weighted imaging (T2WI) and showed homogeneously marked enhancement on contrast-enhanced T1-weighted imaging (T1WI). All lesions showed a hypo- or isointense signal on DWI images with a high b-value. The mean ADC of six lesions was (0.72 ± 0.14) × 10^-3 mm²/s. The TIC of the case examined using DCE-MRI showed a plateau pattern (type II).

CONCLUSION

A well-defined oval mass confined to the muscle belly with a hypointense signal on T2WI, homogeneously marked enhancement on contrast-enhanced T1WI, hypo- or isointense signal on DWI, and low ADC value is highly suggestive of a GCT.

[Analysis of screening results and risk factors of high-risk populations of lung cancer in Nanchang city from 2018 to 2019]

Objective: To collate and analyze the screening results of high-risk lung cancer populations in communities in Nanchang from 2018 to 2019, and to explore the lung-positive nodules and risk factors for lung cancer. Methods: Data of the screening subjects in 8 administrative districts and 15 street health service centers in Nanchang city, Jiangxi province from November 2018 to October 2019 were collected, people at high risk of lung cancer was assessed, clinical screening of high-risk groups of lung cancer was conducted by low-dose helical computed tomography (LDCT), and risk factors for suspected lung cancer and lung-positive nodules were analyzed. Results: Of the 25 871 people participated in screening, 5 220 were at high risk for lung cancer and 15 374 without other malignant tumors were at high risk. There were 2 417 cases participated in clinical LDCT screening, including 193 cases of lung-positive nodules, 67 cases of suspected lung cancer, 912 cases of other lung diseases, the positive rate of lung cancer or lung-positive nodules was 10.76% (260/2 417). Univariate analysis showed that age, coarse grain intake, oil intake, housing heating, passive smoking, alcohol consumption and mental trauma were associated with positive pulmonary nodules or lung cancer (all P<0.05). Multivariate analysis showed that gender, age, housing heating, smoking and drinking were related to the occurrence of lung nodules or lung cancer (all P<0.05). Conclusions: Men are more likely to develop lung cancer or lung-positive nodules than women. The age is an independent risk factor for lung-positive nodules or lung cancer. In a certain range, age will increase the incidence of lung cancer, housing heating may be the protective factor for lung cancer, while smoking and drinking are risk factors.

Predicting haemodynamic significance of coronary stenosis with radiomics-based pericoronary adipose tissue characteristics

AIM

To investigate the diagnostic performance of the radiomics features of pericoronary adipose tissue (PCAT) in determining haemodynamically significant coronary artery stenosis as evaluated by fractional flow reserve (FFR).

MATERIALS AND METHODS

A total of 92 patients with clinically suspected coronary artery disease who underwent coronary computed tomography (CT) angiography (CCTA), invasive coronary angiography (ICA), and FFR examination within 1 month were included retrospectively, and 121 lesions were randomly assigned to the training and testing set. Based on manual segmentation of PCAT, 1,116 radiomics features were computed. After radiomics robustness assessment and feature selection, radiomics models were established using the different machine-learning algorithms. The area under the receiver operating characteristic (ROC) curve (AUC) and net reclassification index (NRI) were analysed to compare the discrimination and reclassification abilities of radiomics models.

RESULTS

Two radiomics features were selected after exclusions, and both were significantly higher in coronary arteries with FFR ≤0.8 than those with FFR >0.8. ROC analysis showed that the combination of CCTA and decision tree radiomics model achieved significantly higher diagnostic performance (AUC: 0.812) than CCTA alone (AUC: 0.599, p=0.015). Furthermore, the NRI of the combined model was 0.820 and 0.775 in the training and testing sets, respectively, suggesting the radiomics features of PCAT had were effective in classifying the haemodynamic significance of coronary stenosis.

CONCLUSIONS

Adding PCAT radiomics features to CCTA enabled identification of haemodynamically significant coronary artery stenosis.

[Pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies]

Objective: To investigate the pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies. Methods: Sputum samples were collected from 967 patients with hematological malignancies and lower respiratory tract infections in Department of Hematology,the Second Hospital of Shanxi Medical University from January 2017 to July 2020. The pathogens and drug sensitivity reports were carried out by automatic bacterial identification instruments. WHONET 5.6 and SPSS 20.0 softwares were used for statistical analysis. Results: A total of 961 strains of pathogens were isolated, 516 (53.7%) pathogens were Gram-negative bacteria, mainly 118 strains of Klebsiella pneumonia (12.3%), 68 strains of Pseudomonas aeruginosa (7.1%), 67 strains of Acinetobacter baumannii (7.0%),52 strains of Stenotrophomonas maltophilia (5.4%), 43 strains of Escherichia coli (4.5%), and 42 strains of Enterbacter cloacae (4.4%). There were 171 (17.8%) strains of Gram-positive bacteria and 274 (28.5%) fungi. The drug resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenem were 22.1%-31.3%. Stenotrophomonas maltophilia was sensitive to levofloxacin, compound sulfamethoxazole and minocycline. The antimicrobial resistance rates of these three enterobacteria to carbapenems, cefoperazone/sulbactam, piperacillin/tazobactam were low (<10%). The resistant Gram-positive bacteria to ticoplanin, vancomycin and linazolamide were not detected. Conclusion: The major pathogens related to lower respiratory tract infections in patients with hematological malignancies are gram-negative bacteria in our centre. Different pathogens appear different characteristics of antimicrobial resistance.

[Vincristine inhibits the proliferation of ovarian cancer cells by regulating the demethylation of RASSF2A]

Objective: To investigate the effect of vincristine on the proliferation of ovarian cancer cells by regulating RASSF2A demethylation. Methods: SKOV3 cells were infected with control (LV-NC) and RASSF2A lentivirus (LV-RASSF2A) and treated with or without vincristine. Cell counting kit-8 (CCK-8) was used to detect the activity of ovarian cancer cells (SKOV3) treated with different doses of vincristine. Colony formation assay was used to detect the proliferation of SKOV3 cells. Flow cytometry was used to detect the apoptosis of SKOV3 cells. Real time polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of RASSF2A in IOSE-29 and SKOV3 cells. Western blot was used to examine the protein expression of RASSF2A in IOSE-29 and SKOV3 cells. Methylation-specific PCR was used to detect methylation and demethylation levels of RASSF2A gene in IOSE-29 and SKOV3 cells. Results: The cell viabilities of SKOV3 cell treated with 6.25 nmol/L, 12.5 nmol/L, 25 nmol/L, 50 nmol/L and 100 nmol/L vincristine were (87.19±4.49)%, (73.67±8.62)%, (66.35±6.04)%, (50.32±6.00)% and (34.92±6.11)%, respectively, lower than (100.46±4.69)% of control group (P<0.05). The half maximal inhibitory concentration of vincristine at 48 hours was 50.02 nmol/L. The proliferation abilities of SKOV3 cells in vincristine 12.5 nmol/L group, 25 nmol/L group and 50 nmol/L group were (41.70±2.21)%, (32.15±1.80)% and (23.00±2.01)%, respectively, significantly lower than (100.78±5.66)% in the control group (all P<0.05). The apoptotic rates of SKOV3 cells in vincristine 12.5 nmol/L group, 25 nmol/L group and 50 nmol/L group were (3.65±0.27)%, (5.21±0.76)% and (10.46±1.00)%, respectively, significantly higher than (2.12±0.23)% in the control group (all P<0.05). Compared with the IOSE-29 group (1.00±0.07 and 0.68±0.04), the mRNA expression (0.32±0.04) and protein expression (0.24±0.02) of RASSF2A were down-regulated in SKOV3 cells (P<0.05). Compared with the LV-NC group [(101.60±4.39)%, (100.73±3.29)%, (4.06±0.30)%], over-expression of RASSF2A down-requlated cell viability (68.92±3.94)%, inhibited proliferation (16.38±2.16)%, and promoted apoptosis (8.65±0.56)%, (P<0.05). Conclusion: Vincristine can increase RASSF2A expression and inhibit ovarian cancer cell proliferation by promoting the demethylation of RASSF2A promoter.

Whole-genome resequencing reveals genetic structure and introgression in Pudong White pigs

Pudong White (PDW) pigs, historically originating from Shanghai, are the only Chinese indigenous pigs characterised by their completely white coats, with the exception of Rongchang pigs. However, there is limited information concerning their overall genetic structure or relationship with other breeds, especially the East Chinese (ECN) and European pigs. To uncover the genetic structure, selection signatures, and potential exotic introgression in PDW pigs, we sampled 15 PDW pigs using whole-genome sequencing (~20×). We then conducted in-depth population genetic analyses in 320 pigs from 27 global pig groups, namely, European wild boars, Chinese wild boars, and outgroup. Neighbour-joining tree and principal component analysis confirmed that PDW pigs belonged to the ecotype of ECN pigs. Both f3, D-statistics, and structure analysis showed that PDW pigs shared apparent alleles with Large White (LW) pigs. Three statistics, rIBD, a haplotype heat map and copy number variation, further indicated that PDW pigs shared apparent alleles with LW pigs at the KIT Proto-Oncogene, Receptor Tyrosine Kinase (KIT) and PARG-MARCHF8 loci, suggesting that the lineage of European pigs in PDW originated from LW pigs. After further detecting the KIT mutations in different pig breeds, PDW was confirmed to have the same duplication region 1, duplication region 2, and the splicing mutation on intron 17 of KIT as LW pigs that determine the white coat colour phenotype in European white pigs. We hypothesised that LW pigs were imported to China ∼110-160 years ago according to the admixture time estimate and then crossed with ECN pigs, resulting in the introgression of the KIT alleles that produce the white coat colour phenotype in the PDW pig breed. To our knowledge, this study presents the first thorough description of the genetic structure of PDW pigs via whole-genome resequencing data; moreover, the results provide a basis for the national project for the conservation of this unique Chinese local population.

High-throughput deterministic pairing and coculturing of single cells in a microwell array using combined hydrodynamic and recirculation flow captures

Single-cell level coculture facilitates the study of cellular interactions for uncovering unknown physiological mechanisms, which are crucial for the development of new therapies for diseases. However, efficient approaches for high-throughput deterministic pairing of single cells and traceable coculture remain lacking. In this study, we report a new microfluidic device, which combines hydrodynamic and recirculation flow captures, to achieve high-throughput and deterministic pairing of single cells in a microwell array for traceable coculture. Compared with the existing techniques, the developed device exhibits advantages with regard to pairing efficiency, throughput, determinacy, and traceability. Through repeating a two-step method, which sequentially captures single cells in a meandering channel and a microwell array, cell number and type can be easily controlled. Double and triple single-cell pairings have been demonstrated with an efficiency of 72.2% and 38.0%, respectively. Cellular engulfment using two breast cell lines is investigated on a developed microfluidic chip as a biological case study, in which the morphological characteristics and the incidence rate are analyzed. This research provides an efficient and reliable alternative for the coculture of single cells on the microfluidic platform for various biomedical applications, such as studying cellular engulfment and tumor sphere formation under single-cell pairing condition.

The effects of aerobic exercise on the intestinal tumors and flora of the ApcMin/+ mouse

INTRODUCTION

Intestinal tumor is one of the most common tumors that seriously threaten the health of residents all over the world. Studies suggest that the imbalance of intestinal flora is associated with tumorgenesis; meanwhile, long-term regular aerobic exercise can improve the occurrence and development of tumors. However, moderate aerobic exercise affecting the development of intestinal tumors and their related flora has not been explored. Thus, the purpose of our study is to explore the effects of aerobic exercise on intestinal tumor growth and flora changes in Apc^Min/+ mice, and try to answer whether there is a correlation between them after exercise intervention.

METHODS

In this study, 18 required Apc^Min/+ mice were randomly divided into Model group (n = 6), Exercise group (n = 6), and Aspirin group (positive control, n = 6), while C57BL/6 J wild-type mice were used as the blank control group. Each group is given corresponding intervention. Weight monitoring, tumor counts, hematoxylin-eosin staining, TdT-mediated dUTP nick-end labeling (TUNEL) fluorescence assay, immunohistochemistry (IHC), fecal sampling and grouping, and bacterial 16S rDNA gene analysis were completed after 12 weeks' intervention for each group of mice.

RESULTS

As a result, we were able to show significant improvements in mice' body weight changing rates (Exercise group 8.6% higher than Model control group), tumor numbers (Exercise group 4.33 ± 0.94 vs. Model control group 7.33 ± 2.49, Then put the slides into xylenewith tumor inhibition rate 40.93%), tumor pathological staging (Exercise group mainly low-grade tumorous adenomas vs. Model group mainly high-grade adenomas), and TUNEL staining (Exercise group 8.59% higher positive rate of apoptotic cells in tumors than Model group). The 16s rRNA sequencing analysis results showed that aerobic exercise could regulate the abundance of some genus (16/149, P < 0.01), and the number of intestinal tumors correlates with changes in the abundance of some bacteria in the intestinal flora (positive correlation with probiotics abundance and negative correlation with conditioned pathogens).

DISCUSSION

Changes in flora abundance may be one of the reasons for aerobic exercise to reduce the number of intestinal tumors, probably mediated by cell apoptosis. Future studies should focus on the potential mechanism of aerobic exercise in preventing intestinal tumorgenesis, especially the molecular mechanism through intestinal flora.

CONCLUSION

Aerobic exercise has a preventive effect on intestinal tumors in Apc^Min/+ mice, and can regulate the abundance of intestinal flora.

CUL4A promotes proliferation and inhibits apoptosis of colon cancer cells via regulating Hippo pathway

OBJECTIVE

The aim of this study was to investigate the effect of cullin 4A (CUL4A) on the proliferation and apoptosis of colon cancer (CC) cells, and to elucidate its regulatory relationship with the Hippo pathway.

PATIENTS AND METHODS

Paired CC tissues and adjacent normal tissues were obtained from patients. CC cells were isolated and cultured in vitro. CUL4A was interfered by small interfering ribonucleic acid (siRNA) (siR-CUL4A group) or overexpressed by overexpression vector (CUL4A-Vector group), with negative control (NC)-CUL4A or CUL4A -NC as the control group. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of CUL4A in CC tissues and cells. The proliferative ability of cells was detected by cell counting kit-8 (CCK-8) assay. Flow cytometry was applied to measure the apoptosis of cells in each group. Western blotting (WB) was conducted to determine the protein expression of CUL4A. In addition, the proliferative ability was examined in vivo through subcutaneous injection of cells into nude mice.

RESULTS

QRT-PCR showed that CUL4A was highly expressed in 66.67% of CC samples (p<0.01). In vivo and in vitro proliferative ability was significantly reduced in siR-CUL4A group (p<0.01), whereas the apoptosis rate was promoted (p<0.01). However, in vivo and in vitro proliferative ability increased significantly in CUL4A-Vector group (p<0.01), while the apoptosis rate was reduced (p<0.01). The protein expressions of MST1, LATS1 and p-YAP were significantly up-regulated in siR-CUL4A group (p<0.01), while they were remarkably down-regulated in CUL4A-Vector group (p<0.05, p<0.01).

CONCLUSIONS

CUL4A is highly expressed in CC and promotes the proliferation and inhibits the apoptosis of CC cells by regulating the Hippo pathway.

Label-free biosensor of phagocytosis for diagnosing bacterial infections

Phagocytic cells recognize and phagocytose invading microbes for destruction. However, bacterial pathogens can remain hidden at low levels from conventional detection or replicate intracellularly after being phagocytosed by immune cells. Current phagocytosis-detection approaches involve flow cytometry or microscopic search for rare bacteria-internalized phagocytes among large populations of uninfected cells, which poses significant challenges in research and clinical settings. Hence it is imperative to develop a rapid, non-disruptive, and label-free phagocytosis detection approach. Using deformability assays and microscopic imaging, we have demonstrated for the first time that the presence of intracellular bacteria in phagocytic blood cells led to aberrant physical properties. Specifically, human monocytes with internalized bacteria of various species were stiffer and larger compared with uninfected monocytes. Taking advantage of these physical differences, a novel microfluidics-based biosensor platform was developed to passively sort, concentrate and quantify rare monocytes with internalized pathogens (MIP) from uninfected monocyte populations for phagocytosis detection. The clinical utility of the MIP platform was demonstrated by enriching and detecting bacteria-internalized monocytes from spiked human blood samples within 1.5 h. Patient-derived clinical isolates were used to validate the utility of the MIP platform further. This proof-of-concept presents a phagocytosis detection platform that could be used to rapidly diagnose microbial infections, especially in bloodstream infections (BSIs), thereby improving the clinical outcomes for point-of-care management.

Effect of radiomics from different virtual monochromatic images in dual-energy spectral CT on the WHO/ISUP classification of clear cell renal cell carcinoma

AIM

To investigate the effect of radiomics obtained from different virtual monochromatic images (VMIs) in dual-energy spectral computed tomography (CT) on the World Health Organization/International Association for Urological Pathology (WHO/ISUP) classification of clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

A retrospective study of 99 ccRCC patients who underwent contrast-enhanced dual-energy CT was undertaken. ccRCC was confirmed at surgery or biopsy and graded according to the WHO/ISUP pathological grading criteria as low grade (n=68, grade I and II) or high grade (n=31, grade III and IV). Radiomics risk scores (RRSs) for differentiating high and low grades of ccRCC were constructed from 11 sets of VMI in (40-140 keV, 10 keV interval) the cortical phase. Receiver operating characteristic (ROC) curves were drawn and the area under the curves (AUCs) was calculated to evaluate the discriminatory power of RRS for each VMI. The Hosmer-Lemeshow test was used to evaluate the goodness-of-fit of each model and the decision curve was used to analyse its net benefit to patients.

RESULTS

The AUC values for distinguishing low-from high-grade ccRCC with RRS of 40-140 keV VMIs were all >0.920. The Hosmer-Lemeshow test showed that the p-values of RRS of VMIs were >0.05, suggesting good fits. In the decision curve analysis, RRS from the 40-140 keV VMIs had similar decision curves and provided better net benefits than considering all patients either as high-grade or low-grade.

CONCLUSIONS

The RRS obtained from multiple VMIs in dual-energy spectral CT have high diagnostic efficiencies for distinguishing between low- and high-grade ccRCC with no significant differences between different VMIs.

Langmuir probe array for the small angle slot divertor in DIII-D

The DIII-D small angle slot (SAS) divertor is designed for divertor physics studies with enhanced neutral confinement and special target geometries in a closed divertor. The closed nature of the SAS makes optical diagnostic measurements difficult, so a specially designed, multipurpose array of Langmuir probes has been implemented to study the plasma conditions in and around the slot. The probes are spaced to provide at least 2 mm resolution (shorter than the energy decay length) of the near scrape-off layer when mapped to the outer mid-plane. Due to space limitations at the bottom of the slot, a novel spring-loaded probe and tile design was developed to clamp several short rooftop probe tips and insulators to the cooled baseplate. Initial probe measurements revealed tile to tile edge shadowing, especially where magnetic field line surface angles were less than 1°. Additionally, it was found, using three Langmuir probes (at 90°, 180°, and 270°), that the strike point variation of ±5 mm radially around the torus was not well aligned with the circular slot geometry [Watkins et al., Nucl. Mater. Energy 18, 46 (2019)]. These issues were resolved by (1) designing tiles with all probes mounted near the tile center instead of near the edges and (2) aligning these new custom tiles to the measured strike point toroidal surface with a very accurate laser scanning alignment tool. Post-alignment Langmuir probe measurements and plasma behavior demonstrated close agreement at two separate toroidal locations that were 45° apart.

[Chaihu Guizhi decoction produces antidepressant-like effects via sirt1-p53 signaling pathway]

OBJECTIVE

To investigate the mechanism of the antidepressant-like effects of Chaihu Guizhi decoction (CGD).

OBJECTIVE

Chaihu Guizhi decoction at the daily dose of 17 g/kg and solvent vehicle were administered by gavage in 12 and 14 male C57BL/6J mice for 7 consecutive days, respectively. Forced swimming test (FST), elevated plus maze (EPM) test, open field test (OFT) and novelty-suppressed feeding test (NSF) were performed to assess the depression- and anxiety-like behaviors and motor ability of the mice. We further used chronic social defeat stress (CSDS) and social interaction test to evaluate the antidepressant-like effects of CGD in comparison with the solvent vehicle. Western blotting and RT-qPCR were performed to detect the expressions of sirt1, p53, acetylated p53, and the neuron plasticity-related genes including synapsin I (Syn1), Rab4B, SNAP25 and tubulin beta4b in the hippocampus of the mice.

OBJECTIVE

In FST, the immobility time of CGDtreated mice was decreased significantly (P < 0.05); no significant differences were found in the performances in EPM, NSF and OFT tests between the two groups. In social interaction test, the mouse models of CSDS treated with CGD showed significantly increased time in the interaction zone (P < 0.05). Compared with those in the vehicle group, the CGD-treated mouse models exhibited significantly increased protein level of SIRT1 and decreased p53 acetylation (P < 0.05) with up-regulated synapsin I mRNA expression in the hippocampus (P < 0.05); no significant difference were found in Rab (P=0.813), SNAP (P=0.820), or Tubb mRNA expressions (P=0.864) between the two groups.

OBJECTIVE

CGD produces antidepressant-like effects in mice possibly through the sirt1-p53 signaling pathway and synaptic plasticity.

An Integrated Approach for High-Shear Wet Granulation (HSWG) Processing of TPGS-Based Formulations: Demonstration of Process Robustness through Experimental Design Conditions

The goal of this study was to understand the impact of high-shear wet granulation (HSWG) processing conditions on product attributes for a tablet formulation containing the non-ionic surfactant TPGS. The use of TPGS in oral solid drug products has been reported to be challenging due to the low melting temperature of TPGS. In addition, literature on TPGS-based HSWG formulations, especially practical processing and scale-up knowledge, is limited. Presented here is an extension of this TPGS application in a tablet formulation, with a focus on the HSWG processing and scale-up across different granulators. To understand the processing space for this TPGS-based HSWG formulation, two consecutive studies were conducted with different objectives. First, an exploratory study was conducted to understand the impact of extreme processing conditions on product attributes. Subsequently, a factorial design of experiment (DoE) study assessed the separate contributions and interactions from HSWG processing variables. The outcome of both studies led to a successful process scale-up and product transfer from lab to commercial development using different granulators. The TPGS-based formulation was demonstrated to provide robust downstream processing (improved flowability and reduced segregation potential) within a wide HSWG operating space, while having a minimal impact on product performance across different granulators.

[Effect of hemocoagulase agkistrodon on coagulation status in patients with traumatic brain injury in vitro]

Objective: To analyze the effects of hemocoagulase agkistrodon (HCA) on the coagulation status of healthy people and traumatic brain injury (TBI) patients in vitro. Methods: A total of 10 TBI patients were enrolled from December 2018 to June 2019,and 24 age and sex matched healthy controls were also enrolled. Clinical and pathological data, blood samples of all subjects were collected. Different gradient concentrations of HCA were added to the blood samples which were detected by thromboelastography, and the R value, K value, α angle and MA value of thromboelastography parameters between the two groups were analyzed to explore the effect of HCA on the coagulation status of patients with TBI. Results: With the increase of HCA concentration in blood samples, the R and K values gradually increased, and the α angles and MA values gradually decreased in both TBI patients group which included 7 males and 3 females, with an median age of 33 (28-39) years old and healthy control group which included 11 males and 13 females, with an median age of 33 (23-49) years old. The differences in the R values, K values, α angles, and MA values of different concentration gradients were statistically significant in both healthy control group and TBI patients group (χ² were 109.80, 131.28, 185.47, 165.97 and 54.92, 75.60, 80.12, 59.25, respectively, all P<0.001). The differences between R values after adding HCA of 0-0.105 U/ml in the healthy group were statistically significant (P=0.025), but K values, α angles and MA values were not statistically significant (P values were 0.275, 0.206 and 0.330, respectively); the R values of the TBI patients group were not statistically significant after adding HCA of 0 to 0.105 U/ml (P=0.976), and the K values, α angles, and MA values were statistically significant (P values were 0.047, 0.041, and 0.034, respectively).The R values of the healthy control group, the TBI patients group, and the overall data were significantly positively correlated with the HCA dose (r values were 0.552、0.700、0.420, respectively, P<0.001), the K values were significantly positively correlated with the HCA dose (r values were 0.726、0.861、0.750, respectively, P<0.001), the α angles were significantly negatively correlated with the HCA dose (r values were -0.815、-0.876、-0.807, respectively, P<0.001) and the MA values were significantly negatively correlated with the HCA dose (r values were -0.757、-0.710、-0.729, respectively, P<0.001). Conclusions: HCA does not aggravate the procoagulant state of blood in healthy people and TBI patients, and with the increase of HCA concentration in blood, the blood samples of both groups show a tendency to decrease the coagulation ability.

Nondestructive quantification of single-cell nuclear and cytoplasmic mechanical properties based on large whole-cell deformation

The mechanical properties of cell nuclei have been recognized to reflect and modulate important cell behaviors such as migration and cancer cell malignant tendency. However, these nuclear properties are difficult to characterize accurately using conventional measurement methods, which are often based on probing or deforming local sites over a nuclear region. The corresponding results are sensitive to the measurement position, and they are not decoupled from the cytoplasmic properties. Microfluidics is widely recognized as a promising technique for bioassay and phenotyping. In this report, we develop a simple and nondestructive approach for the single-cell quantification of nuclear elasticity based on microfluidics by considering different deformation levels of a live cell captured along a confining microchannel. We apply two inlet pressure levels to drive the flow of human nasopharyngeal epithelial cells (NP460) and human nasopharyngeal cancerous cells (NPC43) into the microchannels. A model considering the essential intracellular components (cytoplasm and nucleus) for describing the mechanics of a cell deforming along the confining microchannel is used to back-calculate the cytoplasmic and nuclear properties. On the other hand, we also apply a widely used chemical nucleus extraction technique to examine its possible effects (e.g., reduced nuclear modulus and reduced lamin A/C expression). To determine if the decoupled nuclear properties are representative of cancer-related attributes, we classify the NP460 and NPC43 cells using the decoupled physical properties as classification factors, resulting in an accuracy of 79.1% and a cell-type specificity exceeding 74%. It should be mentioned that the cells can be recollected at the device outlet after the nondestructive measurement. Hence, the reported cell elasticity measurement can be combined with downstream genetic and biochemical assays for general cell research and cancer diagnostic applications.