Precise label-free leukocyte subpopulation separation using hybrid acoustic-optical chip

Leukocyte subpopulations contain crucial physiological information; hence, precise and specific leukocyte separation is very important for leukemia diagnosis and analysis. However, conventional centrifugation and immunofluorescence-based separation methods are inaccurate and inconvenient due to the overlapping cell size and density or complex marking processes. Herein, we report a new label-free technology for precise leukocyte subpopulation separation by synergy of acoustic and optical technologies. Standing surface acoustic wave (SSAW) solved the problem of gentle and precise focusing of cells in optical systems. In addition, SSAW was used for the separation of granulocytes, which have evident size distinction from other components. In case of lymphocytes and monocytes, which have overlap in size/density, optical force could distinguish them accurately based on the RI difference, with the convenience of acoustic pre-focusing. In this experiment, separation of three types of leukocyte subtypes with considerable throughput and purity was conducted, through which we obtained 99% pure lymphocytes, 98% pure monocytes, and 95% pure granulocytes. Experimental results prove that the device has robust ability in separating leukocyte phenotypes and have the advantages of being non-invasive, label-free and precise. In the future, this convenient hybrid method will be a potential powerful tool for auxiliary clinical diagnosis and analysis.

Association between vitamin D deficiency and risk of thyroid cancer: a case-control study and a meta-analysis

PURPOSE

Although vitamin D is reportedly associated with various cancers, the association between vitamin D and thyroid cancer is indefinite. We aimed to investigate whether this association applies to thyroid cancer (TC).

METHODS

A total of 276 Chinese Han people were recruited in a current matched case-control study. Multivariable conditional logistic regression was computed to estimate the association between plasma 25(OH)D and papillary thyroid cancer (PTC). In addition, we searched relevant studies in PubMed and Web of Science databases before December 2017 to conduct a meta-analysis.

RESULTS

In our case-control study, plasma 25(OH)D concentration was inversely associated with PTC risk (highest tertile vs lowest tertile: adjusted OR = 0.25; 95% CI 0.10, 0.61; P_trend = 0.003). This association was independent of body mass index and physical activity (all adjusted P_interaction > 0.05). A total of 11 studies were included in the meta-analysis, among which ten studies have been published and one was our case-control study. Compared with 25(OH)D non-deficient group, the pooled OR of TC was 1.42 (95% CI 1.17, 1.73) in the deficient group. Similarly, blood 25(OH)D levels in patients with TC were tend to be lower than those in the controls (SMD = - 0.20, 95% CI - 0.36, - 0.03).

CONCLUSIONS

A high level of circulating 25(OH)D was associated with a decreased TC risk. This association has important significance in public health and should, therefore, be further studied.

Multicentre study of the prognostic impact of preoperative bodyweight on long-term prognosis of hepatocellular carcinoma

BACKGROUND

Whether preoperative bodyweight is associated with long-term prognosis in patients after liver resection for hepatocellular carcinoma (HCC) is controversial. This study aimed to investigate the relationship of patient weight with long-term recurrence and overall survival (OS) after curative liver resection for HCC.

METHODS

Data for patients with HCC who underwent curative liver resection between 2000 and 2015 in five centres in China were analysed retrospectively in three groups according to their preoperative BMI: underweight (BMI 18·4 kg/m² or less), normal weight (BMI 18·5-24·9 kg/m² ) and overweight (BMI 25·0 kg/m² or above). Patients' baseline characteristics, operative variables and long-term survival outcomes were compared. Univariable and multivariable Cox regression analyses were performed to identify risk factors for OS and recurrence-free survival (RFS) after resection.

RESULTS

Of 1524 patients, 107 (7·0 per cent) were underweight, 891 (58·5 per cent) were of normal weight and 526 (34·5 per cent) were overweight. Univariable analyses showed that underweight and overweight patients had poorer OS (both P < 0·001) and RFS (both P < 0·001) than patients of normal weight. Multivariable Cox regression analysis also identified both underweight and overweight to be independent risk factors for OS (hazard ratio (HR) 1·22, 95 per cent c.i. 1·19 to 1·56, P = 0·019; and HR 1·57, 1·36 to 1·81, P < 0·001, respectively) and RFS (HR 1·28, 1·16 to 1·53, P = 0·028; and HR 1·34, 1·17 to 1·54, P < 0·001).

CONCLUSION

Underweight and overweight patients appear to have a worse prognosis than those of normal weight following liver resection for HCC.

[Rasmussen syndrome: a clinicopathologic study of four cases]

Objective: To investigate the clinicopathologic features of Rasmussen syndrome (RS) and to raise awareness of this rare disease. Methods: Clinicopathologic data of 4 cases of RS were retrospectively analyzed at Beijing Haidian Hospital from 2008 to 2016. Results: The clinical manifestations included epilepsia partialis continua and progressive neurologic deficits in all patients.MRI demonstrated unihemispheric focal cortical atrophy in all cases. The histopathologic changes included variable degrees of lymphocytic infiltrate within the cortex, subarachnoid space and perivascular cuffing.Microglial nodules and neuronophagia were seen. Mild to severe neuronal loss was noted with variable degrees of reactive gliosis. Spongy edema and cavitation were observed in focal cortex. Inflammation involving hippocampus was seen in one case. Three cases were accompanied by focal cortical dysplasia (FCD) Ⅲd. Immunohistochemical staining showed that the infiltrative lymphocytes were positive for CD3, CD8, granzyme B and TIA1 and the proliferating microglial cells were positive for CD68. NeuN positive neurons decreased significantly and reactive astrocytes were GFAP positive. Conclusions: Pathologic changes of RS are similar to viral encephalitis and the inflammation is progressive and multifocal involving the hemisphere. The diagnosis of RS relies on pathologic features combined with clinical findings and neuroradiological examinations.

Interferon-gamma response to the treatment of active pulmonary and extra-pulmonary tuberculosis

BACKGROUND

Interferon-gamma (IFN-γ) release assays (IGRAs) are used to diagnose tuberculosis (TB) but not to measure treatment response.

OBJECTIVE

To measure IFN-γ response to active anti-tuberculosis treatment.

DESIGN

Patients from the Henan Provincial Chest Hospital, Henan, China, with TB symptoms and/or signs were enrolled into this prospective, observational cohort study and followed for 6 months of treatment, with blood and sputum samples collected at 0, 2, 4, 6, 8, 16 and 24 weeks. The QuantiFERON® TB-Gold assay was run on collected blood samples. Participants received a follow-up telephone call at 24 months to determine relapse status.

RESULTS

Of the 152 TB patients enrolled, 135 were eligible for this analysis: 118 pulmonary (PTB) and 17 extra-pulmonary TB (EPTB) patients. IFN-γ levels declined significantly over time among all patients (P = 0.002), with this decline driven by PTB patients (P = 0.001), largely during the initial 8 weeks of treatment (P = 0.019). IFN-γ levels did not change among EPTB patients over time or against baseline culture or drug resistance status.

CONCLUSION

After 6 months of effective anti-tuberculosis treatment, IFN-γ levels decreased significantly in PTB patients, largely over the initial 8 weeks of treatment. IFN-γ concentrations may offer some value for monitoring anti-tuberculosis treatment response among PTB patients.

[Pathological analysis and treatments of neck infection induced by congenital pyriform sinus fistula]

Objective:To identify the pathogenic bacteria of CPSF and their resistance to antibiotics,and guide the rational use of antibiotics therapy.Method:One hundred and thirty cases of deep neck infection whose imaging finding depicted patients with suspected as CPSF were enrolled in the study from January 2010 to June 2017.Specimens were collected from abscesses or other inflammatory lesions from all patients through a small incision or the external orifice on the skin of the neck.Result:A total of 108 strains of pathogens have been isolated from 88 patients (positive rate: 67.7%), among which the gram-positive bacteria accounted for 56.5%, gram-negative bacteria accounted for 43.5%. Streptococcus and Staphylococcus aureus (22.2%) were the most common pathogens among young patients (≤14 years old) (17.7%);Klebsiellapneumoniae (15.7%) were the most common pathogens among the patients over 14 years old. Separation of pathogenic bacteria have maintained a low resistance to most antibiotics. G+ bacteria is totally sensitive to quinupristin/dalfopristin and vancomycin; G-bacteria is totally sensitive to cefoperazone/Batan, piperacillin/tazobactam,imipenem.Conclusion:Most of pathogens come from upper respiratory tract in CPSF cases, and are mostly sensitive to βlactamase.

The Role of Mitochondria-Associated Reactive Oxygen Species in the Amyloid β Induced Production of Angiogenic Factors b y ARPE-19 Cells

OBJECTIVE

This study aimed to investigate the mechanisms whereby Amyloidbeta (Aβ) induces the production of angiogenic factors by a human retinal pigment epithelial cell line (ARPE-19) cells.

METHODS

ARPE-19 cells obtained from the American Type Culture Collection (ATCC) were utilized in this study. The expression level of vascular endothelial growth factor (VEGF), Interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1) and complement activation fragments C3a and C5a were measured by Real-time quantitative PCR (RT-PCR) and Enzyme-linked immunosorbent assay (ELISA). The production of mitochondria-associated reactive oxygen species (ROS) was measured by flow cytometry.

RESULTS

The expression of VEGF, IL-8, MCP-1, C3a and C5a was significantly increased in Aβ-treated ARPE-19 cells. Mitochondria-associated ROS production was also significantly increased when exposed to Aβ. Inhibition of mitochondrial ROS with Diphenyleneiodonium chloride (DPI) markedly decreased the Aβ induced production of VEGF, IL-8, MCP-1, C3a and C5a by ARPE-19 cells. Anti-C3a or anti-C5a neutralizing antibodies did not have a detectable influence on the secretion of VEGF, IL-8 and MCP-1 by ARPE-19 cells upon stimulation with Aβ.

CONCLUSION

Our results support the hypothesis that Aβ is involved in the pathogenesis of choroidal neovascularization (CNV) formation by promoting the production of the angiogenic cytokines VEGF, IL-8 and MCP-1 by RPE cells. Mitochondrial ROS was shown to play a role in the regulation of Aβ induced expression of these cytokines.

Real-time detection and monitoring of the drug resistance of single myeloid leukemia cells by diffused total internal reflection

Real-time detection and monitoring of the drug resistance of single cells have important significance in clinical diagnosis and therapy. Traditional methods operate a number of times for each individual concentration, and innovation is required for the design of more simple and efficient manipulation platforms with necessary higher sensitivity. Here, we have developed a novel diffused total internal reflection (TIR) method to perform drug metabolism and cytotoxicity analysis of trapped myeloid leukemia cells. Molm-13 cells, a type of acute myeloid leukemia cell, were chosen and injected into the device and fittingly captured by cell traps. Differing from previous studies, a series of different concentrations of azelaic acid (AZA) drug could be used from 0 mM to 50 mM through convection and diffusion processes in a single chip, with each concentration region featuring 50 cells, with a total of 549 cell trapping units. Thanks to the high sensitivity of the TIR method, only cells with the same drug concentration could be illuminated in the detection process. By adjusting the incident angle, we could exactly detect and monitor the drug resistance of the cells using different drug concentrations and the experimental resolution of the drug concentration was as small as 5 mM. Images of the membrane integrity and morphology of the cells in the bright field were measured and we also monitored the cell viabilities in the dark field over 2 hours. The effects of AZA on the Molm-13 cells were explored in different concentrations at the single cell level. Compared with the results of the traditional MTT assay method, the experimental results are more simple and accurate. A cell death of 5% at an AZA concentration of 5 mM was observed after 30 minutes, while a concentration of 40 mM corresponded to a 98% cell death. The designed method in this study provides a novel toolkit to control and monitor drug resistance at the single cell level more easily with higher sensitivity and we believe it has significant potential application in single cell quality assessment and medicine analysis in clinical practice.

[Application of anoptomagnetic probe Gd-DO3A-EA-FITC in imaging and analyzing the brain interstitial space]

OBJECTIVE

To investigate the application of the optical magnetic bimodal molecular probe Gd-DO3A-ethylthiouret-fluorescein isothiocyanate (Gd -DO3A-EA-FITC) in brain tissue imaging and brain interstitial space (ISS).

METHODS

In the study, 24 male SD rats were randomly divided into 3 groups, including magnetic probe group (n=6), optical probe group (n=6) and optical magnetic bimodal probe group (n=12), then the optical magnetic bimodal probe group was divided equally into magnetic probe subgroup (n=6) and optical probe subgroup (n=6). Referencing the brain stereotaxic atlas, the coronal globus pallidus as center level, the probes including gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA), fluorescein isothiocyanate (FITC) and Gd-DO3A-EA-FITC of 2 μL (10 mmol/L) were injected into the caudate nucleus respectively, magnetic resonance imaging (MRI) was performed in the magnetic probe group and magnetic probe subgroup to image the dynamic diffusion and distribution of the probes in the brain ISS, a self-developed brain ISS image processing system was used to measure the diffusion coefficient, clearance, volume fraction and half-time in these two groups. Laser scanning confocal microscope (LSCM) was performed in vitro in the optical probe group and optical probe subgroup for fluorescence imaging at the time points 2 hours after the injection of the probe, and the distribution in the oblique sagittal slice was compared with the result of the first two groups.

RESULTS

For the magnetic probe group and magnetic probe subgroup, there were the same imaging results between the probes of Gd-DTPA and Gd-DO3A-EA-FITC. The diffusion parameters of Gd-DTPA and Gd-DO3A-EA-FITC were as follows: the average diffusion coefficients [(3.31±0.11)×10^-4 mm²/s vs. (3.37±0.15)×10^-4 mm²/s, t=0.942, P=0.360], the clearance [(3.04±0.37) mmol/L vs. (2.90±0.51) mmol/L, t=0.640, P=0.531], the volume fractions (17.18%±0.14% vs. 17.31%±0.15%, t=1.961, P=0.068), the half-time [(86.58±3.31) min vs. (84.61±2.38) min, t=1.412, P=0.177], the diffusion areas [(23.25±0.68) mm² vs. (22.71±1.00) mm², t=1.100, P=0.297]. The statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant. Moreover, for the optical probe group and optical probe subgroup, the diffusion area of Gd-DO3A-EA-FITC [(22.61±1.16) mm²] was slightly larger than that of FITC [(22.10±1.29) mm²], the statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant (t=0.713, P=0.492).

CONCLUSION

Gd-DO3A-EA-FITC shows the same imaging results as the traditional GD-DTPA, and it can be used in measuring brain ISS.