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.

Recent progress in the development of metal complexes as β-amyloid imaging probes in the brain

In this review, we have focused on the recent progress in metal complexes that are able to bind to β-amyloid (Aβ) species. We have discussed various radioactive complexes of 99mTc, 68Ga, 64Cu, 89Zr, and 111In, which were designed as Aβ imaging agents for positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging, non-radioactive Re and Ru complexes as Aβ sensors using luminescence methods, and Gd3+ complexes as contrast agents for magnetic resonance imaging (MRI).

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.

18F-Labeled indole-based analogs as highly selective radioligands for imaging sigma-2 receptors in the brain

We have designed and synthesized a series of indole-based σ₂ receptor ligands containing 5,6-dimethoxyisoindoline or 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline as pharmacophore. In vitro competition binding assays showed that all ten ligands possessed low nanomolar affinity (K_i=1.79-5.23nM) for σ₂ receptors and high subtype selectivity (K_i (σ₂)/K_i (σ₁)=56-708). Moreover, they showed high selectivity for σ₂ receptor over the vesicular acetylcholine transporter (>1000-fold). The corresponding radiotracers [¹⁸F]16 and [¹⁸F]21 were prepared by an efficient one-pot, two-step reaction sequence with a home-made automated synthesis module, with 10-15% radiochemical yield and radiochemical purity of >99%. Both radiotracers showed high brain uptake and σ₂ receptor binding specificity in mice.

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.

Highly specific noninvasive photoacoustic and positron emission tomography of brain plaque with functionalized croconium dye labeled by a radiotracer

Highly-efficient targeting probes are desirable for disease diagnosis and functional imaging. However, most of the current near-infrared (NIR) probes suffer from low signal conversion, insufficient photostability, poor probe specificity, and limited functions. Herein, an NIR ultrahigh absorbing croconium dye for amyloid (CDA) was designed and synthesized to specifically bind to cerebrovascular amyloid without antibody linkage. This unique CDA is able to strongly bind the hydrophobic channels of amyloid beta (Aβ) fiber with a very strong binding energy of -9.3 kcal mol-1. Our experimental results demonstrate that the amphipathic dye with an intense absorption peak at 800 nm generated a significant local temperature surge under low-power laser irradiation. Compared with representative prominent indocyanine green, Prussian blue, and gold nanorods, this probe can produce the strongest photoacoustic signal based on the same mass concentration. Labeled with radioactive 18F, this multifunctional probe allowed for the ultrasensitive photoacoustic tomography (PAT)/positron emission tomography (PET)/fluorescence imaging of Aβ plaques in the brain cortex. Featured with high spatial resolution and optical specificity, PAT was intrinsically suitable for imaging pathological sites on cortical vessels, whereas PET revealed whole-body anatomy with quantitative biodistribution information. Our study shows that a CDA-based functionalized dye aided with PAT and PET is capable of plaque diagnosis and localization.

18F-Labeled Benzyldiamine Derivatives as Novel Flexible Probes for Positron Emission Tomography of Cerebral β-Amyloid Plaques

Early noninvasive visualization of cerebral β-amyloid (Aβ) plaques with positron emission tomography (PET) is the most feasible way to diagnose Alzheimer's disease (AD). In this study, a series of flexible benzyldiamine derivatives (BDA) were proposed for binding to aggregated β-amyloid 1-42 (Aβ_1-42) with high adaptability, high binding affinity (6.8 ± 0.6 nM), and rapid body excretion. The methylthio (12) and ethoxyl (10) derivatives were further labeled with ¹⁸F directly on their benzene ring and examined as PET probes for Aβ plaque imaging. [¹⁸F]12 displayed 4.87 ± 0.52% ID/g initial uptake and prompt washout from normal brain in biodistribution studies. MicroPET-CT imaging indicated sufficient retention of [¹⁸F]12 but lower white matter uptake in the brain of an AD transgenic mouse model compared with that of commercial [¹⁸F]AV-45. Our experimental results provide new insights for developing targeting ligands possessing a flexible framework for use as efficient Aβ probes for PET imaging of AD brain.

Synthesis and Monkey-PET Study of (R)- and (S)-18F-Labeled 2-Arylbenzoheterocyclic Derivatives as Amyloid Probes with Distinctive in Vivo Kinetics

This study describes an effective strategy to improve pharmacokinetics of Aβ imaging agents, offering a novel class of (R)- and (S)-¹⁸F-labeled 2-arylbenzoheterocyclic derivatives which bear an additional chiral hydroxyl group on the side chain. These ligands displayed binding abilities toward Aβ aggregates with K_i values ranging from 3.2 to 195.6 nM. Chirality-related discrepancy was observed in biodistribution, and (S)-2-phenylbenzoxazole enantiomers exhibited vastly improved brain clearance with washout ratios higher than 20. Notably, (S)-[¹⁸F]28 possessed high binding potency (K_i = 7.6 nM) and exceptional brain kinetics (9.46% ID/g at 2 min, brain_2min/brain_60min = 27.8) that is superior to well-established [¹⁸F]AV45. The excellent pharmacokinetics and low nonspecific binding of (S)-[¹⁸F]28 were testified by dynamic PET/CT scans in monkey brains. In addition, (S)-[¹⁸F]28 clearly labeled Aβ plaques both in vitro and ex vivo. These results might qualify (S)-[¹⁸F]28 to detect Aβ plaques with high signal-to-noise ratio.

Optically Pure Diphenoxy Derivatives as More Flexible Probes for β-Amyloid Plaques

The highly rigid and planar scaffold with π-conjugated systems has been widely considered to be indispensable for Aβ binding probes. However, the flexible benzyloxybenzene derivative [(125)I]BOB-4 represents an excellent lead candidate for targeting Aβ in AD brains. Based on that, we designed two pairs of more flexible and optically pure diphenoxy derivatives with a chiral center as novel Aβ probes. These compounds possessed high affinity (Ki = 15.8-45.0 nM) for Aβ1-42 aggregates, and (R)-enantiomers showed slightly better binding ability than (S)-enantiomers. In addition, the competition binding assay implied that the optically pure diphenoxy derivatives with more flexible geometry shared the same binding site as IMPY, a classical rigid and planar Aβ probe. For (125)I-radiolabeled enantiomers, (S)-[(125)I]5 and (R)-[(125)I]5, specific plaque labeling on brain sections of Tg mice and AD patients were observed in in vitro autoradiography, persuasively proving the excellent affinity of the probes. In biodistribution, (S)-[(125)I]5 and (R)-[(125)I]5 with relatively low lipophilicity exhibited moderate initial brain uptake (4.37% and 3.72% ID/g at 2 min, respectively) and extremely fast washout from normal mice brain (brain2min/brain60min = 19.0 and 17.7, respectively). In summary, the separate enantiomers displayed similar properties in vitro and in vivo, and (S/R)-[(123)I]5 may be potential SPECT probes for recognizing Aβ plaques in AD brains.