Design, modeling, and experimental validation of an acoustofluidic platform for nanoscale molecular synthesis and detection

Microfluidic technologies are increasingly implemented to replace manual methods in biological and biochemical sample processing. We explore the feasibility of an acoustofluidic trap for confinement of microparticle reaction substrates against continuously flowing reagents in chemical synthesis and detection applications. Computational models are used to predict the flow and ultrasonic standing wave fields within two longitudinal standing bulk acoustic wave (LSBAW) microchannels operated in the 0.5-2.0 MHz range. Glass (gLSBAW) and silicon (siLSBAW) pillar arrays comprise trapping structures that augment the local acoustic field, while openings between pillars evenly distribute the flow for uniform exposure of substrates to reagents. Frequency spectra (acoustic energy density E _ac vs frequency) and model-predicted pressure fields are used to identify longitudinal resonances with pressure minima in bands oriented perpendicular to the inflow direction. Polymeric and glass particles (10- and 20-µm diameter polystyrene beads, 6 µm hollow glass spheres, and 5 µm porous silica microparticles) are confined within acoustic traps operated at longitudinal first and second half-wavelength resonant frequencies (f _1,E = 575 kHz, gLSBAW; f _1,E = 666 kHz; and f _2,E = 1.278 MHz, siLSBAW) as reagents are introduced at 5-10 µl min^-1. Anisotropic silicon etched traps are found to improve augmentation of the acoustic pressure field without reducing the volumetric throughput. Finally, in-channel synthesis of a double-labeled antibody conjugate on ultrasound-confined porous silica microparticles demonstrates the feasibility of the LSBAW platform for synthesis and detection. The results provide a computational and experimental framework for continued advancement of the LSBAW platform for other synthetic processes and molecular detection applications.

New findings of heparanase in human diseases

OBJECTIVE

This mini-review aims to discuss research works about heparanase published in 2017 and 2018 and provide a direction for therapy methods targeting heparanase.

PATIENTS AND METHODS

The relevant data were searched by using keywords "heparanase", "function", "diseases" and "inhibitors" in "PubMed, "Web of Science" and "China Knowledge Resource Integrated databases (CNKI)", and a hand-search was done to acquire peer-reviewed articles and reports about heparanase.

RESULTS

Except for tumor progression, pathological processes including procoagulant activities, preeclamptic placentas, inflammation and so on are all verified to be associated with heparanase activity. Also, these newly-found functions are closely connected to certain cellular activities, including epithelial to mesenchymal transition (EMT).

CONCLUSIONS

It could be concluded that heparanase would be a potential and valuable therapeutic target.

[Correlation between serum CD147 and carotid intraplaque hemorrhage]

Objective: Intraplaque hemorrhage (IPH) is one of the most important causes of ischemic stroke. The purpose of this study was to explore the association between carotid IPH and CD147, which may be the serum marker related to IPH. Methods: Serum samples were collected from 68 patients with carotid artery stenosis from April to September 2004. 3.0T MRI with the 8 channel surface coil was used to scan carotid artery. Images was processed by MRI-PlaqueView. The integrity of lipid, IPH, calcified components and fibrous cap in the plaque was analysed qualitatively and quantitatively. The correlation and difference analysis among serum CD147 and plaque components were carried out. Results: Serum CD147 level in IPH positive was higher than that in IPH negative, 5 510.1 vs 4 648.0 (P=0.04). There was no significant correlation among serum CD147 and the quantitative parameters of lipid, IPH and calcification in carotid plaque and fibrous cap rupture. Serum CD147 in patients using statins was lower than that in patients not using statins, 4 914.0 vs 5 926.7 (P<0.01). Serum total cholesterol and LDL were positively correlated with serum CD147. In patients without statin, serum CD147 had a better diagnostic value for carotid IPH (AUC=0.81, P=0.04, 95% CI 0.62-0.99). Conclusion: Serum CD147 would probably be one biomarker of IPH and shows good diagnostic value of carotid IPH in the specific population.

Expression and significance of peripheral myeloid-derived suppressor cells in chronic hepatitis B patients

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) exert their suppressive effects on multiple immune response and contribute to the development of many diseases. However, limited data is available on the involvement of MDSCs in human chronic HBV infection.

OBJECTIVE

To investigate whether the progression of chronic HBV infection was associated with imbalance of MDSCs.

METHODS

The percentages of MDSCs, regulatory T (Treg), Th1 and Tc1 cells in the peripheral blood from chronic hepatitis B (CHB) patients and healthy controls (HC) were determined by flow cytometry. Plasma levels of IL-10, TGF-β and IFN-γ were measured using enzyme-linked immunosorbent assay. The potential association of the frequencies of MDSCs with clinical parameters was assessed.

RESULTS

The percentages of MDSCs and Treg cells were significantly higher in CHB patients than those in HC. The percentages of MDSCs were negatively correlated with Th1 cells. Increased plasma IL-10 level and decreased IFN-γ level were found in CHB patients compared with HC. Moreover, the frequencies of MDSCs and plasma IL-10 levels were positively correlated with serum HBV DNA loads, as well as liver function impairment.

CONCLUSION

The expanded peripheral MDSCs may contribute to poor viral clearance and disease progression during chronic HBV infection.

Augmented longitudinal acoustic trap for scalable microparticle enrichment

We introduce an acoustic microfluidic device architecture that locally augments the pressure field for separation and enrichment of targeted microparticles in a longitudinal acoustic trap. Pairs of pillar arrays comprise "pseudo walls" that are oriented perpendicular to the inflow direction. Though sample flow is unimpeded, pillar arrays support half-wave resonances that correspond to the array gap width. Positive acoustic contrast particles of supracritical diameter focus to nodal locations of the acoustic field and are held against drag from the bulk fluid motion. Thus, the longitudinal standing bulk acoustic wave (LSBAW) device achieves size-selective and material-specific separation and enrichment of microparticles from a continuous sample flow. A finite element analysis model is used to predict eigenfrequencies of LSBAW architectures with two pillar geometries, slanted and lamellar. Corresponding pressure fields are used to identify longitudinal resonances that are suitable for microparticle enrichment. Optimal operating conditions exhibit maxima in the ratio of acoustic energy density in the LSBAW trap to that in inlet and outlet regions of the microchannel. Model results guide fabrication and experimental evaluation of realized LSBAW assemblies regarding enrichment capability. We demonstrate separation and isolation of 20 μm polystyrene and ∼10 μm antibody-decorated glass beads within both pillar geometries. The results also establish several practical attributes of our approach. The LSBAW device is inherently scalable and enables continuous enrichment at a prescribed location. These features benefit separations applications while also allowing concurrent observation and analysis of trap contents.

[Related factors for the development of fulminant myocarditis in adults]

Objective: To determine the early recognizable factors related to patients with fulminant myocarditis. Methods: Medical records from 60 adult patients who were diagnosed with acute viral myocarditis from January 2003 to September 2016 in our hospital were retrospectively reviewed, and divided into the fulminant group (n=9) and the non-fulminant group (n=51). Clinical presentations, biochemical markers, electrocardiography and echocardiography features on admission were analyzed. Results: Prevalence of syncope (33.3%(3/9) vs. 2.0% (1/51), P=0.009) and fatigue (77.8% (7/9) vs. 21.6% (11/51) , P=0.002) was significantly higher, while the duration from flu-like syndromes to chest discomfort was shorter ((2.0±1.8) days vs. (4.5±3.5) days, P=0.041) in the fulminant group than that in the non-fulminant group. Systolic blood pressare (SBP) ((94±14) mmHg(1 mmHg=0.133 kPa) vs. (117±12)mmHg, P=0.001) and left ventricular ejection fraction((49±12)% vs. (60±13)%, P=0.016) were significantly lower, while heart rate ((99±20)bpm vs. (84±19)bpm, P=0.040) and NT-proBNP concentration ((7 962 (1 470, 23 849) ng/L vs. 1 771 (45, 2 380) ng/L, P=0.000) were significantly higher in the fulminant group than those in the non-fulminant group. PR interval was longer (199 (140, 416) ms vs. 156 (112, 204) ms, P=0.021), QRS complex was wider ((127±14)ms vs. (95±13)ms, t=-6.647, P<0.001) in the fulminant group than those in the non-fulminant group. Prolonged QRS duration≥120 ms was more often in fulminant group (77.8%(7/9) vs. 5.9%(3/51), P=0.000). Multivariate analysis revealed that PR interval (adjusted odd ratio 1.044, 95%CI 1.005-1.084, P=0.025) and QRS complex width (adjusted odd ratio 1.252, 95%CI 1.045-1.501, P=0.015) were the independent risk factors significantly associated with fulminant myocarditis. Conclusions: The risk of a fulminant course of acute myocarditis is higher in patients with elevated NT-proBNP, reduced left ventricular ejection fraction, and conduction disturbances at admission. Prolonged PR interval and widened QRS complex on admission are independent risk factors for developing fulminant myocarditis in adult patients with acute viral myocarditis.

Correlation between childhood eczema and specific IgG antibody level

Eczema, a common pediatric dermatosis with unclear pathogenesis, can seriously affect the life quality of children due to its recurrence and long course. Recent study has found that food specific IgG (sIgG) might be involved in the course of eczema. To analyze the correlation between childhood eczema and sIgG and evaluate the role of avoiding taking intolerance food in the treatment of childhood eczema, this study enrolled 216 children with eczema who were admitted to the Taian Maternal and Child Health Care Hospital, Shandong, China, between August 2014 and October 2015. They were divided into an eczema group (N = 140) and an allergy group (N = 76). Eighty healthy children who were admitted to the Department of Children Healthcare in the same period were selected as a control group. Enzymelinked immuno sorbent assay (ELISA) was used to detect the serum sIgG level. The result showed that the sIgG positive rates of children in the eczema group and allergy group were 91.4% and 93.4%, respectively, and the difference had no statistical significance (P > 0.05). However, the sIgG positive rates of children in the eczema group and allergy group were significantly higher than that in the control group (P less than 0.05). Milk and eggs were the major allergy-causing food for children with sIgG positive rates higher than 70%. The sIgG test results revealed that eggs had the highest allergenicity, followed by milk, tomatoes and soybeans, and pork was not highly sensitive. Therefore, it can be concluded that sIgG positive rate of children with eczema is high, and examination of food sIgG antibody in serum is valuable in the diagnosis and treatment of childhood eczema.

In silico prediction of multiple-category classification model for cytochrome P450 inhibitors and non-inhibitors using machine-learning method

The cytochrome P450 (CYP) enzyme superfamily is involved in phase I metabolism which chemically modifies a variety of substrates via oxidative reactions to make them more water-soluble and easier to eliminate. Inhibition of these enzymes leads to undesirable effects, including toxic drug accumulations and adverse drug-drug interactions. Hence, it is necessary to develop in silico models that can predict the inhibition potential of compounds for different CYP isoforms. This study focused on five major CYP isoforms, including CYP1A2, 2C9, 2C19, 2D6 and 3A4, that are responsible for more than 90% of the metabolism of clinical drugs. The main aim of this study is to develop a multiple-category classification model (MCM) for the major CYP isoforms using a Laplacian-modified naïve Bayesian method. The dataset composed of more than 4500 compounds was collected from the PubChem Bioassay database. VolSurf+ descriptors and FCFP_8 fingerprint were used as input features to build classification models. The results demonstrated that the developed MCM using Laplacian-modified naïve Bayesian method was successful in classifying inhibitors and non-inhibitors for each CYP isoform. Moreover, the accuracy, sensitivity and specificity values for both training and test sets were above 80% and also yielded satisfactory area under the receiver operating characteristic curve and Matthews correlation coefficient values.

[Feasibility and value of index of microcirculatory resistance in patients with acute myocardial infarction after primary percutaneous coronary intervention]

Objective: To evaluate the feasibility of detecting index of microcirculatory resistance (IMR) and the relationship between IMR and left ventricular (LV) systolic function after acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). Methods: The patients with first AMI received primary PCI in Peking University Third Hospital were enrolled from January 2014 to March 2016. IMR were measured immediately after PCI by using pressure/temperature wire. The relationship between IMR and left ventricular ejection fraction (LVEF) assessed by echocardiography at first day and 6 months after admission was evaluated. Results: Twenty-eight patients with anterior wall AMI were enrolled, with an average age (56±13) years. The success rate of IMR detection was 100%. The mean IMR was (33±18 )mmHg·s. There was no complication related to intravenous adenosine triphosphate (ATP) (140 μg· kg(-1)· min(-1)). The IMR was negatively correlated with TIMI blood flow grade after primary PCI (r=-0.386, P=0.043), and positively correlated with female gender, CK peak value and TnT peak value (r=0.430, P=0.022; r=0.431, P=0.025; r=0.434, P=0.024). After 6 months of follow-up, no adverse cardiovascular events (including cardiac death, nonfatal myocardial infarction, malignant arrhythmia, unplanned revascularization, hospitalization for unstable angina pectoris and severe heart failure requiring hospitalization) occurred. LVEF increased significantly compared with the first day after PCI (0.54±0.08 vs 0.47±0.06, P=0.001), and IMR was negatively correlated with LVEF after 6 months (r=-0.477, P=0.014). Multivariable linear regression analysis showed that CK peak and IMR were predictors of LVEF after six months ( β=-0.595, t=-3.814, P=0.01; β=-0.352, t=-2.26, P=0.036). Conclusions: Immediate detection of IMR in patients with anterior wall AMI after PCI is safe and feasible. The immediate IMR after PCI reflects the extent of myocardial necrosis and myocardial perfusion, and is a predictor of LVEF at 6 months after PCI.

Effects of microRNA-21 targeting PITX2 on proliferation and apoptosis of pituitary tumor cells

OBJECTIVE

Expression of pituitary homeobox 2 (PITX2) is significantly elevated in pituitary adenoma tissues, which also has lower microRNA (miR)-21 expression, indicating possible tumor-suppression role of miR-21. Bio-informatics analysis revealed targeting onto 3'-UTR of PITX2 by miR-21. This study aims to investigate the role of miR-21/PITX2 expression in proliferation and apoptosis of pituitary adenoma cells and pathogenesis.

PATIENTS AND METHODS

A total of 48 pituitary adenoma samples were collected in parallel with 12 normal brain tissues and were recruited in this study. Flow cytometry was employed to test Ki-67 expression and apoptosis. Expressions of miR-21 and PITX2 were compared, along with their targeted relationship by dual-luciferase reporter assay. Cultured HP75 cells were transfected with miR-21 mimic and/or si-PITX2. Caspase-3 activity was further quantified, followed by flow cytometry for apoptosis. MiR-21, cleaved caspase-3 and PITX2 expressions were tested.

RESULTS

Invasive pituitary adenoma tissues had significantly higher Ki-67 and PITX2, and lower miR-21 expressions or apoptosis than non-invasive tumors. MiR-21 targeted 3'-UTR of PITX2 gene to inhibit its expression. Elevated miR-21 and/or silencing PITX2 significantly depressed PITX2 expression in HP75 cells, potentiating caspase-3 activity, decreasing cell proliferation and facilitating apoptosis.

CONCLUSIONS

MiR-21 was down-regulated while PITX2 was up-regulated in pituitary adenoma tissues. MiR-21 can inhibit pituitary adenoma cell HP75 proliferation and facilitate apoptosis via inhibiting PITX2 expression.

Continuous blood purification in children with severe sepsis

This study aims to analyse the clinical effects of continuous blood purification (CBP) in children with severe sepsis to form a basis for CBP application in this context. One hundred and twenty children with severe sepsis treated in Binzhou People’s Hospital, Shandong, China, from June 2013 to June 2014 were divided into two groups, a treatment and a control group, depending on parental preference. The control group was treated conventionally, and the treatment group underwent CBP in addition to conventional therapy. Cardiovascular and respiratory parameters were measured on admission and after 72 h. This study also assayed interleukin (IL)-8 and tumour necrosis factor (TNF)-α levels, and monitored clinical outcomes and prognosis. The cardiovascular and respiratory parameters of the treatment group improved to a significantly greater extent than did those of the control group (all P less than 0.05). After treatment, the levels of IL-8, IL-6, IL-10, and TNF-α declined in both groups, but more so in the treatment group (all P<0.05). The white blood cell count and C-reactive protein level fell more in the treatment than control group, with statistical significance (both P less than 0.05). CBP remarkably improved the cardiovascular and respiratory functions of children with severe sepsis, probably by eliminating factors mediating inflammation.

Zoledronic Acid Improves Bone Quality in the Streptozotocin-Induced Diabetes Rat through Affecting the Expression of the Osteoblast-Regulating Transcription Factors

AIMS

To evaluate the short term effect of zoledronic acid on bone remodeling in the streptozotocin induced diabetes rats.

MATERIALS AND METHODS

Diabetes was induced by an injection of streptozotocin (60 mg/kg). The rats were treated with zoledronic acid (0.1 mg/kg) at the onset of diabetes (Z-I group) and 2 weeks later (Z-II group). Rats were sacrificed at the 1, 2, 3, 4 and 5 weeks after the onset of diabetes. Real-time PCR and western blot were performed to detect the expression of the following osteogenic gene mRNAs and their proteins: bone morphogenetic proteins 2 (BMP2), Runx2, Osterix and Noggin. The bone mineral density (BMD) and the mechanical resistance test was measured.

RESULTS

BMP2, Runx2 and Osterix mRNA and protein expression in group D had regulated down, while Noggin expression increased. Z-I treatment could reverse the results. However group Z-II showed only a transient reversing effect. On the 5^th week in group D, the BMD decreased, the bone trabecular distance increased, while the trabecular thickness and bone trabecular volume were reduced, the biomechanics index decreased significantly. Zoledronic acid treatment restored these alterations.

CONCLUSIONS

Zoledronic acid administered in the early stage of the diabetes could prevent the osteopenia. The underlying mechanisms might be that zoledronic acid treatment reversed the effect of diabetes on the expression of osteoblast-regulating transcription factors: BMP2, Runx2 and Osterix.