Expression and self-assembly of virus-like particles from porcine parvovirus and its application in antibody detection

Porcine parvovirus (PPV) is a major causative agent in reproductive pig disease. The swine industry faces a significant economic and epizootic threat; thus, finding a reliable, quick, and practical way to detect it is essential. In this investigation, recombinant PPV VP2 protein was expressed in the Escherichia coli ( E. coli) expression systems. As shown by electron microscopy (TEM), Western blot, and hemagglutination (HA) assays, the recombinant VP2 protein was successfully assembled into virus-like particles (VLPs) after being expressed and purified. These VLPs had a structure that was similar to that of real PPV viruses and also exhibited HA activity. These VLPs induced high levels of PPV-specific antibody titers in mice after immunization, indicating that the VLPs may be beneficial as potential candidate antigens. VLPs were used as the coating antigens for the VLP ELISA, and the PPV VLPs-based ELISA displayed a high sensitivity (99%), specificity (93.0%) and agreement rate (98.3%) compared to HI assay, and the agreement rate of this ELISA was 97.5% compared to a commercial ELISA kit. Within a plate, the coefficient of variation (CV) was 10%, and between ELISA plates, the CV was 15%. According to a cross-reactivity assay, the technique was PPV-specific in contrast to other viral illness sera. The PPV VLP indirect-ELISA test for PPV detection in pigs with an inactivated vaccine showed that the PPV-positive rate varied among different sample sources from 88.2 to 89.6%. Our results indicate that this ELISA technique was quick, accurate, and repeatable and may be used for extensive serological research on PPV antibodies in pigs.

A portable automated chip for simultaneous rapid point-of-care testing of multiple β-agonists

Abusive use of β-agonists as feed additives for animals and medication is detrimental to human health and food safety. Conventional assays are restricted to a single type of β-agonists detection and cannot match the multiplexing features to perform automated, high throughput, and rapid quantitative analysis in real samples. In this research, we develop a portable automated chip system (PACS) with highly integrated automated devices in conjunction with portable microfluidic chips to provide simultaneous point-of-care testing of multiple β-agonists in the field, simplifying complex manual methods, shortening assay times, and improving sensitivity. Specifically, silicon film is used as reaction substrates for immobilizing the conjugates of β-agonists to increase the sensitivity of the assay result. Then, the PACS with a chemiluminescence imaging detector is established for automatic high-throughput and sensitive detection of Clenbuterol, Ractopamine, and Salbutamol based on the indirect immunoassay. Newly developed chip with high mixing performance can improve the sensitivity of target determination. Multiplex assays were carried out using the developed system for Clenbuterol, Ractopamine, and Salbutamol with a limit of detection of 54 pg mL-1,59 pg mL-1, and 93 pg mL-1, respectively. Except for sample preparation and coating, the detection in the PACS takes less than 47 min. A satisfactory sample recovery (86.33%-108.12%) was obtained, validating the reliability and practical applicability of this PACS. Meanwhile, the PACS enables sensitive and rapid detection of multiple β-agonists in farms or markets where lacking advanced laboratory facilities.

Heterochromatic silencing of immune-related genes in glia is required for BBB integrity and normal lifespan in drosophila

Glia and neurons face different challenges in aging and may engage different mechanisms to maintain their morphology and functionality. Here, we report that adult-onset downregulation of a Drosophila gene CG32529/GLAD led to shortened lifespan and age-dependent brain degeneration. This regulation exhibited cell type and subtype-specificity, involving mainly surface glia (comprising the BBB) and cortex glia (wrapping neuronal soma) in flies. In accordance, pan-glial knockdown of GLAD disrupted BBB integrity and the glial meshwork. GLAD expression in fly heads decreased with age, and the RNA-seq analysis revealed that the most affected transcriptional changes by RNAi-GLAD were associated with upregulation of immune-related genes. Furthermore, we conducted a series of lifespan rescue experiments and the results indicated that the profound upregulation of immune and related pathways was not the consequence but cause of the degenerative phenotypes of the RNAi-GLAD flies. Finally, we showed that GLAD encoded a heterochromatin-associating protein that bound to the promoters of an array of immune-related genes and kept them silenced during the cell cycle. Together, our findings demonstrate a previously unappreciated role of heterochromatic gene silencing in repressing immunity in fly glia, which is required for maintaining BBB and brain integrity as well as normal lifespan.

Inhibition of the MEK/ERK pathway suppresses immune overactivation and mitigates TDP-43 toxicity in a Drosophila model of ALS

TDP-43 is an important DNA/RNA-binding protein that is associated with age-related neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD); however, its pathomechanism is not fully understood. In a transgenic RNAi screen using Drosophila as a model, we uncovered that knockdown (KD) of Dsor1 (the Drosophila MAPK kinase dMEK) suppressed TDP-43 toxicity without altering TDP-43 phosphorylation or protein levels. Further investigation revealed that the Dsor1 downstream gene rl (dERK) was abnormally upregulated in TDP-43 flies, and neuronal overexpression of dERK induced profound upregulation of antimicrobial peptides (AMPs). We also detected a robust immune overactivation in TDP-43 flies, which could be suppressed by downregulation of the MEK/ERK pathway in TDP-43 fly neurons. Furthermore, neuronal KD of abnormally increased AMPs improved the motor function of TDP-43 flies. On the other hand, neuronal KD of Dnr1, a negative regulator of the Drosophila immune deficiency (IMD) pathway, activated the innate immunity and boosted AMP expression independent of the regulation by the MEK/ERK pathway, which diminished the mitigating effect of RNAi-dMEK on TDP-43 toxicity. Finally, we showed that an FDA-approved MEK inhibitor trametinib markedly suppressed immune overactivation, alleviated motor deficits and prolonged the lifespan of TDP-43 flies, but did not exhibit a lifespan-extending effect in Alzheimer disease (AD) or spinocerebellar ataxia type 3 (SCA3) fly models. Together, our findings suggest an important role of abnormal elevation of the MEK/ERK signaling and innate immunity in TDP-43 pathogenesis and propose trametinib as a potential therapeutic agent for ALS and other TDP-43-related diseases.

Construction of a desirable hyperbolic microfluidic chip for ultrasensitive determination of PCT based on chemiluminescence

Since procalcitonin (PCT) is a specific inflammation indicator of severe bacterial inflammation and fungal infection, it is of great significance to construct a sensitive and rapid microfluidic chip to detect PCT in clinical application. The design of micromixers using a lab-on-a-chip (LOC) device is the premise to realizing the adequate mixing of analytical samples and reagents and is an important measure to improve the accuracy and efficiency of determination. In this research study, we investigate the mixing characteristics of hyperbolic micromixers and explore the effects of different hyperbolic curvatures, different Reynolds numbers (Re) and different channel widths on the mixing performance of the micromixers. Then, an optimal micromixer was integrated into a microfluidic chip to fabricate a desirable hyperbolic microfluidic chip (DHMC) for the sensitive determination of inflammation marker PCT with a limit of detection (LOD) as low as 0.17 ng mL^-1via a chemiluminescence signal, which can be used as a promising real-time platform for early clinical diagnosis.

Power Enhancement of 265 nm DUV-LED Flip-Chip by HVPE-AlN High-Temperature Annealing

In this paper, the X-ray diffraction full width at half the maximum (XRD FWHM) of a 3.5 µm-thick hydride vapor phase epitaxy-aluminum nitride (HVPE-AlN) (002) face after high-temperature annealing was reduced to 129 arcsec. The tensile strain in the HVPE-AlN samples gradually released with the increasing annealing temperature. When the annealing temperature exceeded 1700 °C, an aluminum oxynitride (AlON) region was generated at the contact interface between HVPE-AlN and sapphire, and the AlON structure was observed to conform to the characteristics of Al5O6N by high-resolution transmission electron microscopy (HRTEM). A 265 nm light-emitting diode (LED) based on an HVPE-AlN template annealed at 1700 °C achieved a light output power (LOP) of 4.48 mW at 50 mA, which was approximately 57% greater than that of the original sample.

A cascade Fermat spiral microfluidic mixer chip for accurate detection and logic discrimination of cancer cells

Since cancer has emerged as one of the most serious threats to human health, the highly sensitive determination of cancer cells is of significant importance to improve the accuracy of early clinical diagnosis. In our investigation, a novel cascade Fermat spiral microfluidic mixer chip (CFSMMC) combined with fluorescence sensors as a point-of-care (POC) testing system is successfully fabricated to detect and differentiate cancer cells (MCF-7) from normal cells with excellent sensitivity and selectivity. Here, copper ions (Cu²⁺) with peroxidase properties can catalyze the oxidation of the non-fluorescent substrate Amplex Red (AR) to the highly fluorescent resorufin (ox-AR) in the presence of hydrogen peroxide (H₂O₂). Subsequently, thanks to the quenching response of AS1411-AuNPs to ox-AR in the microchannel and the binding of AS1411 to nucleolin on the surface of cancer cells, a CFSMMC-based POC system is established for the highly sensitive detection and identification of human breast cancer cells in a "turn on" manner. The change in fluorescence intensity is linearly related to the concentration of MCF-7, ranging from 10² to 10⁷ cells per mL with a limit of detection (LOD) as low as 17 cells per mL. Interestingly, the cascaded AND logic gate is integrated with CFSMMC for the first time to distinguish cancer cells from normal cells under the control of logic functions, which exhibits great potential in the development of one-step rapid and intelligent detection and logic discrimination.

MicroRNA-29a-3p regulates chemosensitivity in hypopharyngeal carcinoma via targeting Cdc42

INTRODUCTION

Hypopharyngeal carcinoma is one kind of high malignant tumour followed by poor prognosis in head and neck carcinomas. This study aimed to detect miR-29a-3p and Cdc42 in patients with hypopharyngeal carcinoma.

MATERIALS AND METHODS

The expression of miR-29a-3p and Cdc42 mRNA were detected, and the correlation between miR-29a-3p/Cdc42 and clinical stages was investigated.

RESULTS

The relative expression of miR-29a-3p in stage II, III and IV hypopharyngeal carcinoma tissues was significantly lower than that of stage I (P< 0.05). The relative expression of Cdc42 mRNA in stage I, III and IV tissues was significantly higher than that of stage I (P< 0.05). The expression of miR-29a-3p in hypopharyngeal carcinoma with lymph node metastasis was significantly lower than that without lymph node metastasis (P = 0.045).

CONCLUSION

MiR-29a-3p and Cdc42 mRNA could be potential diagnostic biomarkers of hypopharyngeal carcinoma.

[Induction of peripheral blood mononuclear cells to hepatocyte-like cells and preliminary study of cell response to injury under the effect of acetaminophen]

Objective: To establish a method for the induction of peripheral blood mononuclear cells to hepatocyte-like cells, and preliminarily investigate cell response to injury under the effect of acetaminophen (APAP). Methods: The surface marker CD45 of peripheral blood mononuclear cells wase detected cells by using flow cytometry and immunofluorescence methods. The cellular morphology of induced hepatocyte-like cells was observed under an inverted microscope. Real-time fluorescent quantitative PCR (RT-PCR) was used to detect the expression level of hepatocyte-specific genes, such as cytochrome (CY) P1A2, CYP3A4, CYP2C9, albumin (ALB), alpha-fetoprotein (AFP), and hepatocyte nuclear factor (HNF)4α mRNA. Immunofluorescence method was used to detect intracellular hepatocyte markers AFP, HNF4α, and ALB expression at the protein level. Biochemical analyzer was used to detect hepatocyte-specific secretory functions of AFP, ALB, and urea. Luciferase chemiluminescence method was used to detect the activity of key drug metabolizing enzyme CYP3A4. Colorimetric assay was used to detect the effect of the drug acetaminophen on hepatocyte-like cells, and alanine aminotransferase (ALT) was used as an indicator of liver cell injury. The statistical differences between the data were compared with t-test and rank-sum test. Results: The positive expression rate of CD45 cell surface markers isolated from peripheral blood mononuclear cells was about 98%, and hepatocyte-like cell morphology changes appeared on 15th day of induction. Compared with isolated mononuclear cells, CYP1A2, CYP3A4, CYP2C9, ALB, AFP and HNF4α mRNA was markedly elevated. The expression level of AFP, ALB and HNF4α protein were equally increased, and the secretory function of AFP, ALB and urea were enhanced. Compared with primary hepatocytes, CYP1A2, CYP2C9, AFP, HNF4α mRNA, and CYP3A4 mRNA did not decrease. The expression levels of AFP, ALB, and HNF4α proteins in the cells did not decrease, and the secretory function of AFP, ALB, and urea did not decrease. In addition, the CYP3A4 enzyme activity produced by hepatocyte-like cells was similar to that of primary hepatocytes. Compared with hepatocyte-like cells incubated without APAP, hepatocyte-like cells incubated with APAP had higher ALT level. Under the effect of APAP, the ALT level of hepatocyte-like cells was higher than isolated mononuclear cells. Conclusion: Peripheral blood mononuclear cells can be induced into hepatocyte-like cells with partial characteristics of hepatocytes, including the activity of CYP3A4, a key enzyme of hepatocyte drug metabolism. Additionally, preliminarily ALT secretory features reflect the hepatocytes injury under the effect of acetaminophen.

CHMP2B regulates TDP-43 phosphorylation and cytotoxicity independent of autophagy via CK1

The ESCRT protein CHMP2B and the RNA-binding protein TDP-43 are both associated with ALS and FTD. The pathogenicity of CHMP2B has mainly been considered a consequence of autophagy–endolysosomal dysfunction, whereas protein inclusions containing phosphorylated TDP-43 are a pathological hallmark of ALS and FTD. Intriguingly, TDP-43 pathology has not been associated with the FTD-causing CHMP2B^Intron5 mutation. In this study, we identify CHMP2B as a modifier of TDP-43–mediated neurodegeneration in a Drosophila screen. Down-regulation of CHMP2B reduces TDP-43 phosphorylation and toxicity in flies and mammalian cells. Surprisingly, although CHMP2B^Intron5 causes dramatic autophagy dysfunction, disturbance of autophagy does not alter TDP-43 phosphorylation levels. Instead, we find that inhibition of CK1, but not TTBK1/2 (all of which are kinases phosphorylating TDP-43), abolishes the modifying effect of CHMP2B on TDP-43 phosphorylation. Finally, we uncover that CHMP2B modulates CK1 protein levels by negatively regulating ubiquitination and the proteasome-mediated turnover of CK1. Together, our findings propose an autophagy-independent role and mechanism of CHMP2B in regulating CK1 abundance and TDP-43 phosphorylation.

Micromixer with Fine-Tuned Mathematical Spiral Structures

Micromixers with the microchannel structure can enable rapid and efficient mixing of multiple types of fluids on a microfluidic chip. Herein, we report the mixing performance of three passive micromixers based on the different mathematical spiral structures. We study the fluid flow characteristics of Archimedes spiral, Fermat spiral, and hyperbolic spiral structures with various channel widths and Reynolds number (Re) ranging from 0 to 10 via numerical simulation and visualization experiments. In addition, we analyze the mechanism of streamlines and Dean vortices at different cross sections during fluid flows. As the fluid flows in the Fermat spiral channel, the centrifugal force induces the Dean vortex to form a chaotic advection, enhancing the fluid mixing performance. By integrating the Fermat spiral channel into a microfluidic chip, we successfully detect acute myocardial infarction (AMI) marker with the double-antibody sandwich method and reduce the detection time to 10 min. This method has a low reagent consumption and a high reaction efficiency and demonstrates great potential in point-of-care testing (POCT).

Improvement in the Output Power of Near-Ultraviolet LEDs of p-GaN Nanorods through SiO2 Nanosphere Mask Lithography with the Dip-Coating Method

In this paper, the conditions of the dip-coating method of SiO₂ nanospheres are optimized, and a neatly arranged single-layer SiO₂ array is obtained. On this basis, a "top-down" inductively coupled plasma (ICP) technique is used to etch the p-GaN layer to prepare a periodic triangular nanopore array. After the etching is completed, the compressive stress in the epitaxial wafer sample is released to a certain extent. Then, die processing is performed on the etched LED epitaxial wafer samples. The LED chip with an etching depth of 150 nm has the highest overall luminous efficiency. Under a 100 mA injection current, the light output power (LOP) of the etched 150 nm sample is 23.61% higher than that of the original unetched sample.

Epitaxial Growth of GaN on Magnetron Sputtered AlN/Hexagonal BN/Sapphire Substrates

Magnetron sputtering is adopted to deposit ~25 nm thick AlN on the surface of hexagonal BN(h-BN)/sapphire substrates, followed by epitaxial GaN growth on top of the AlN/h-BN/sapphire substrate using a metal-organic chemical vapor deposition system. Compared to GaN grown on the h-BN/sapphire surface directly, this method results in a continuous and smooth GaN film with a smaller root mean square roughness. Besides, the introduction of the sputtered AlN layer reduces the dislocation density of GaN by 35.7%. We provide a pathway of GaN epitaxy on the h-BN surface, which significantly improves its surface morphology and crystal quality.

Inhibition of CD44 attenuates pressure overload-induced cardiac and lung inflammation, fibrosis, and heart failure progression

Background

Inflammation contributes to heart failure (HF) development and progression. CD44 is a member of the hyaluronate receptor family of cell adhesion molecules, which regulates tissue inflammation and fibrosis through modulating macrophage and lymphocyte migration and homing in several diseases. Here we evaluated the role and cellular mechanism of CD44 in regulating transverse aortic constriction (TAC)-induced HF development and progression in mice.

Methods and results

C57/B6 background CD44 KO and wild type mice (6–8 weeks) were subjected to TAC to evaluate the effect of CD44 on the development of TAC-induced LV hypertrophy and cardiac dysfunction. Due to the rapid response to TAC, Balb/c mice (6–8 weeks) were used to determine the effect of CD44 on the progression of TAC-induced congestive heart failure. We found that CD44 expression is dramatically increased in left ventricular (LV) tissues obtained from HF patients and mice. While CD44 gene knockout (KO) has no detectable effect on cardiac structure and function under control conditions, CD44 KO mice were protected from TAC-induced LV inflammation, fibrosis, hypertrophy, dysfunction, and lung remodeling as compared with wild type mice. In addition, we found that inhibition of CD44 signaling with blocking antibodies (Abs) significantly attenuated the transition from LV failure to lung remodeling, and right ventricular hypertrophy in mice with existing HF.

Conclusions

These data identify an important role of CD44 in attenuating cardiac and lung inflammation, fibrosis, HF development, and HF progression, suggesting that inhibition of CD44 signaling may be useful in preventing and treating HF.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Chinese National Natural Science Foundation Grants and American Heart Association

Using a Multi-Layer Stacked AlGaN/GaN Structure to Improve the Current Spreading Performance of Ultraviolet Light-Emitting Diodes

To obtain excellent current spreading performance of ultraviolet light-emitting diodes (UVLEDs), a 60-period stacked Si modulation-doped n-AlGaN/u-GaN structure is proposed to replace the traditional n-AlGaN structure. The high-resolution X-ray diffraction ω-scan rocking curves show that the periodic growth of AlGaN and GaN layers plays a positive role in reducing dislocation density. Compared with the conventional UV light-emitting diodes (LEDs), light emission micrographs of devices with a multi-layer stacked n-AlGaN/u-GaN structure reveal higher brightness and a more uniform distribution. In addition, the output power and external quantum efficiency under a 20-mA injection current are increased by 22% and 26.5%, respectively. Experimental and simulation results indicate that a multi-layer stacking structure can alleviate the current crowding effect in four ways: (1) a reduction in dislocation density; (2) replacement of quasi-two-dimensional electron transport with electronic bulk transport to enhance electron mobility; (3) an increase in electron concentration without improving the impurity concentration; and (4) a weakening of the electron scattering effect by reducing the impurity concentration.

[The role of poloxamer 188 for cord blood mononuclear cells into megakaryocytes cultivation and induction in three-dimensional WAVE Bioreactor]

目的

观察泊洛沙姆188（P188）对体外三维（3D）培养诱导脐血单个核细胞向巨核细胞分化的影响。

方法

将分离的脐血单个核细胞分别接种于细胞瓶和细胞培养袋中，后者采用WIGGENS摇床模拟生物反应器进行3D培养。在巨核细胞诱导培养基中加入P188体外培养14 d，观察细胞形态、计数细胞数并计算细胞存活率，采用流式细胞术观察巨核细胞表面标志表达情况。

结果

与采用传统的细胞培养瓶二维（2D）培养诱导巨核细胞相比，2D+P188培养组巨核系CD41⁺、CD41⁺/CD61⁺、CD61⁺细胞数明显增加（P值均<0.01）；在3D培养中加入P188，细胞体积变大，核形状不规则，胞质含紫红色颗粒，细胞分化更接近成熟。2D培养、3D培养及3D+P188培养组组间巨核细胞表面标志CD41、CD41/CD61、CD61表达水平差异有统计学意义（P值均<0.01）。LSD-t检验两两比较显示，与2D培养相比，3D培养诱导巨核细胞存活率及细胞数均降低（P值分别为0.018、0.027），3D+P188培养组细胞数、细胞存活率与2D和3D培养组比较差异均无统计学意义（P值均>0.05）。而3D培养组巨核细胞CD41/CD61表达水平为（36.30±1.27）%，高于2D培养组的（23.95±1.34）%（P=0.002），3D+P188培养组CD41/CD61表达水平更高[（59.45±1.20）%]。

结论

3D培养有利于巨核系祖细胞诱导分化，但细胞存活率低，加入P188，细胞生存状态好，且诱导效率更高。

Colorectal laterally spreading tumours : subtype evaluation by EUS and BLI and outcome of ESD

BACKGROUND AND STUDY AIMS

Colorectal laterally spreading tumour (LST) is a specific type of colonic space-occupying lesion unlike other common polypoid lesions. Here, we explored the diagnostic values of endoscopic ultrasonography (EUS) and blue laser image (BLI) in LST subtypes, their relationship with histopathological characteristics and the therapeutic effect of endoscopic submucosal dissection(ESD) for LST.

PATIENTS AND METHODS

A prospective study of 138 patients with LST was conducted. All LSTs were explored for invasion depth and superficial microstructure through EUS and BLI before ESD. Histopathological characteristics of LSTs were demonstrated through pre-operative biopsy and post-operative specimen detection. Finally, the correlations among varied morphologies, manifestations of EUS and BLI, and histopathological characteristics of LSTs were analysed comprehensively. All patients underwent follow-up after ESD.

RESULTS

Nodular-mixed and pseudodepressed subtypes were more likely to invade the submucosa, and BLI revealed a greater proportion of types B and C than the homogeneous or flat-elevated subtypes. These endoscopic features were consistent with and proved by histopathological results. Pathological severity of LST on post-ESD specimen detection was greater than that on pre-ESD biopsy analysis. En bloc R0 resection was achieved in 128 cases, and only two patients suffered recurrence during follow-up.

CONCLUSIONS

Pre-operative evaluation through EUS and BLI examination provided clues of possible pathological features and helped guide the treatment of LST. ESD is a safe and effective therapy for colorectal LST.

Cause or prevention of breast cancer with estrogens: analysis from tumor biologic data, growth kinetic model and Women's Health Initiative study

The existing medical literature suggests that estrogens may cause breast cancer but, paradoxically, can also prevent this neoplasm under specific circumstances. Appropriate interpretation of this complex data requires an understanding of emerging concepts of tumor biology. A substantial body of data, including animal models and epidemiologic studies, suggests that estrogens contribute to the development of breast cancer. Additionally, pre-clinical experiments indicate that the responsible mechanisms include both estrogen receptor α-dependent and -independent effects (ERα-dependent and ERα-independent effects). We recently developed two models to describe the growth kinetics of occult breast tumors, one based on autopsy studies and tumor doubling time and the other, computer-based. Validation of the models involved comparison of the predicted incidence of breast cancer with the actual incidence in population-based studies. Utilization of these models allowed us to determine that 16 years on average are required for tumors to undergo the 30 doubling times necessary for the occult tumors to reach the threshold for clinical detection. These models suggest that menopausal hormone therapy with estrogen plus a progestogen in the Women's Health Initiative (WHI) study accelerated the doubling time of occult, pre-existing tumors from 200 to 150 days and thus, increased the rate of tumor diagnosis. Based on estrogen-induced apoptosis data, the model accurately predicted the prevention of diagnosed breast cancer in the estrogen-alone arm of the WHI. Notably, pre-clinical studies demonstrated that conjugated equine estrogen, as used in the WHI, has unique, pro-apoptotic properties compared to the anti-apoptotic effects of estradiol, a finding providing an explanation for the reduction in breast cancer with conjugated equine estrogen.

[Dynamic change of population structure of Oncomelania hupensis]

Objective To understand the successive dynamic change of population structure of Oncomelania hupensis during a one-year period, so as to provide the evidence for snail control. Methods A river beach and a ditch infested with O. hupensis snails were selected and longitudinally investigated in the midmonth during one year. The snail survey indices included the survival status, gender, number of whorls, length and width of shell, and gonad development status (measured by the color depth of gonad and the length ratio of gonad to liver), and the monthly snail eggs in the soil were collected and counted simultaneously. In addition, the temperature and humidity of the soil and the daily data of air temperature and precipitation were measured or collected during the study period (every month). Results Both survival rate of snails and live snail density at the two environments were positively correlated with the temperatures of air and soil. With a slight bimodal distribution, the snail survival rate peaked from May to June, and in September. The living snail densities got the highest level in July and September in the river beach, and from April to May in the ditch. The regression equations of snail length (L) and width (W) were L_beach = 2.355 + 1.678W (F = 2 989.43, P < 0.01) and L_ditch = 0.478 + 2.091W (F = 2.989.43, P < 0.01), respectively. The snails were the ones with 4.07-11.81 mm in the length (8.98 ± 0.92) mm in the river beach, and the snails were the ones with 3.63-9.92 mm in the length (7.03 ± 0.82) mm in the ditch. The main snails were the ones with five to eight whorls of shell in the river beach and four to seven whorls of shell in the ditch. The proportions of snails with less than or equal to five whorls (in the river beach) and four (in the ditch) were the highest in May and September, about 20%. The ratios of male and female snails were 1.66 in the river beach and 1.22 in the ditch, respectively. The gonad development status of male and female snails was basically synchronous and had a bimodal abundance period - from April to May and September to October. The numbers of snail eggs in the soil among months were significantly different, reaching the highest in June in the river beach (100.8/0.1 m²), and May in the ditch (82.5/ 0.1 m²). Conclusion The principal periods of breeding and alternation of generations of snails are April-May and SeptemberOctober every year, which should also be the optimal time for mollusciciding in schistosomiasis susceptible zones.

Common variants on 2p16.1, 6p22.1 and 10q24.32 are associated with schizophrenia in Han Chinese population

Many schizophrenia susceptibility loci have been identified through genome-wide association studies (GWASs) in European populations. However, until recently, schizophrenia GWASs in non-European populations were limited to small sample sizes and have yielded few loci associated with schizophrenia. To identify genetic risk variations for schizophrenia in the Han Chinese population, we performed a two-stage GWAS of schizophrenia comprising 4384 cases and 5770 controls, followed by independent replications of 13 single-nucleotide polymorphisms in an additional 4339 schizophrenia cases and 7043 controls of Han Chinese ancestry. Furthermore, we conducted additional analyses based on the results in the discovery stage. The combined analysis confirmed evidence of genome-wide significant associations in the Han Chinese population for three loci, at 2p16.1 (rs1051061, in an exon of VRK2, P=1.14 × 10-12, odds ratio (OR)=1.17), 6p22.1 (rs115070292 in an intron of GABBR1, P=4.96 × 10-10, OR=0.77) and 10q24.32 (rs10883795 in an intron of AS3MT, P=7.94 × 10-10, OR=0.87; rs10883765 at an intron of ARL3, P=3.06 × 10-9, OR=0.87). The polygenic risk score based on Psychiatric Genomics Consortium schizophrenia GWAS data modestly predicted case-control status in the Chinese population (Nagelkerke R2: 1.7% ~5.7%). Our pathway analysis suggested that neurological biological pathways such as GABAergic signaling, dopaminergic signaling, cell adhesion molecules and myelination pathways are involved in schizophrenia. These findings provide new insights into the pathogenesis of schizophrenia in the Han Chinese population. Further studies are needed to establish the biological context and potential clinical utility of these findings.

Pathway-wide association study identifies five shared pathways associated with schizophrenia in three ancestral distinct populations

Genome-wide association studies have confirmed the polygenic nature of schizophrenia and suggest that there are hundreds or thousands of alleles associated with increased liability for the disorder. However, the generalizability of any one allelic marker of liability is remarkably low and has bred the notion that schizophrenia may be better conceptualized as a pathway(s) disorder. Here, we empirically tested this notion by conducting a pathway-wide association study (PWAS) encompassing 255 experimentally validated Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways among 5033 individuals diagnosed with schizophrenia and 5332 unrelated healthy controls across three distinct ethnic populations; European-American (EA), African-American (AA) and Han Chinese (CH). We identified 103, 74 and 87 pathways associated with schizophrenia liability in the EA, CH and AA populations, respectively. About half of these pathways were uniquely associated with schizophrenia liability in each of the three populations. Five pathways (serotonergic synapse, ubiquitin mediated proteolysis, hedgehog signaling, adipocytokine signaling and renin secretion) were shared across all three populations and the single-nucleotide polymorphism sets representing these five pathways were enriched for single-nucleotide polymorphisms with regulatory function. Our findings provide empirical support for schizophrenia as a pathway disorder and suggest schizophrenia is not only a polygenic but likely also a poly-pathway disorder characterized by both genetic and pathway heterogeneity.

[High glucose reduced the repair function of kidney stem cells conditional medium to the hypoxia-injured renal tubular epithelium cells]

OBJECTIVE

To evaluate the impacts of high glucose on the repair function of kidney stem cells (KSC) conditional medium to the hypoxia-injured renal tubular epithelium cells (RTEC).

METHODS

KSC were isolated from the renal papilla in 4-week-Sprague-Dawley rats. The KSC were pretreated in media with high glucose (30 mmol/L) or with normal glucose (5.6 mmol/L), respectively. The supernatants of the pre-treated KSC were collected as the conditional media. The hypoxia/reoxygenation (H/R) model of rat RTEC was established using the NRK-52E cell line. The effects of KSC conditional media on the H/R RTEC were investigated.

RESULTS

(1) The best H/R model of RTEC was established using hypoxia for 4 h and reoxygenation 2 h. (2) After hypoxia, the early and late cell apoptosis rates of the H/R RTEC were increased. The H/R RTEC were co-cultured with KSC conditional media for 12 h and 24 h, respectively. The H/R RTEC were co-cultured with DMEM/F12 as a control group. The cell apoptosis rate of H/R RTEC was lower after co-cultured with KSC conditional media (P<0.01), and the cell apoptosis rate of H/R RTEC in high glucose group was much higher than that in normal glucose group after co-cultured 24 h (P=0.02). (3) After hypoxia, the lactic dehydrogenase (LDH) and malondialdehyde (MDA) levels of the H/R RTEC supernatant were increased, and the superoxide dismutase (SOD) level decreased. The LDH and MDA levels were lower and the SOD level was higher after co-cultured with KSC conditional media for 12 h and 24 h, respectively (P<0.01). The LDH and MDA levels of H/R RTEC supernatant were much higher in the high glucose group than in the normal glucose group (P<0.05), and the SOD level of H/R RTEC supernatant was much lower in the high glucose group than in the normal glucose group (P<0.01).

CONCLUSION

KSC conditional media could repair the H/R injury of RTEC. The effects were mainly by inhibiting cell apoptosis, and reducing oxidative stress; the anti-cell apoptosis ability and the anti-oxidative stress capacity of the conditional medium were reduced after KSC were pre-treated with high glucose.

Brief Questionnaire Derived from PANSS Using a General Probability Model to Assess and Monitor the Clinical Features of Schizophrenia

AIM

Patients with schizophrenia require continuous treatment much longer than the duration of their hospitalization, which makes their family members essential in their medical care. However, the evaluation of the disease state could only be done by professionals. This prompted us to seek potent indicators of disease states that are understandable and easy to use for the patients' family.

METHOD

Specific items were firstly extracted from the total PANSS scale. Then 3 096 PANSS scores were analyzed using a nonlinear mixed-effects model (NONMEM). A questionnaire was subsequently developed for family members to assess and monitor the overall severity of schizophrenia. Finally this questionnaire was validated in 33 patients.

RESULTS

2 items (P1 and N4) were extracted from the 8 effective remission items according to the correlation coefficients between the total PANSS score and different combinations of items. P1N4 was defined as the sum of these 2 items. A model was then developed to describe the probability of PANSS≥60, with P1N4 as indicators. The results indicated that P1N4 could make a good predictor of the overall probability of PANSS≥60, which was independent of treatment. A brief questionnaire with 7 questions was developed based on the results. External validation results indicated the questionnaire's suitability for a good assessment.

CONCLUSION

Questionnaire developed based on P1 and N4 may facilitate the patients' family members to better understand the disease state and help to prevent relapse.

Pharmacokinetic study of isatin in dog plasma by liquid chromatography tandem mass spectrometry

AIM

A sensitive and selective method was developed and validated to study the pharmacokinetics of isatin.

METHODS

The blood samples were pretreated by protein precipitation method using methanol. Quetiapine was used as an internal standard. After pretreatment, the samples were assayed by LC/MS/MS method and the pharmacokinetic parameters were calculated by WinNonlin 5.2 using non-compartment model. The separation was performed on a Venusil XBP PH column (5 µm, 2.0×100 mm) with an isocratic mobile phase consisted of methanol-water (containing 50 mM ammonium formate) (65:35, v/v) at a flow rate of 0.3 mL/min. The Agilent G6410B triple quadrupole LC/MS system was operated under the multiple reactions monitoring mode (MRM) using the electrospray ionization technique in positive mode.

RESULTS

The lower limits of quantification (LLOQ) of the analyte of the method was 10 ng/mL. The method was linear with correlation coefficient >0.995. The intraday and interday accuracy and precision of the assay were acceptable.

CONCLUSION

This method has been applied successfully to a pharmacokinetic study involving the oral and intravenous administration of isatin to beagle dogs.

Determination of patellar ligament and anterior cruciate ligament geometry using MRI

Ligament geometry is crucial to surgical treatment success in anterior cruciate ligament (ACL) injury. This study aimed to optimize the MRI technique to elucidate the geometry of the patellar ligament (PL) and ACL in vivo. A 1.5-T superconducting MRI system with a special surface coil and fast spin echo was used to acquire high-resolution T1-weighted images (H-T1WI) of the ACL. The sagittal plane angle was 10° to 15° towards the inner side of the vertical line of the tangent line axis of the femoral intercondylar fossa. The H-T1WI images of the PL were centered at the lower margin of the patella and the center of the tibial tuberosity. The lengths of the PL and ACL were measured using a Radworks 5.1 workstation. ACL and PL lengths were compared between left and right knees and between genders, and left PL length measurements obtained separately by three doctors underwent correlation analysis. The quality of the images satisfied the clinical measurement requirements. The duration of sagittal image acquisition was 2 min and 25 s. The average PL length was 42.20 ± 4.21 and 40.15 ± 4.00 mm, and the average ACL length was 36.98 ± 4.12 and 35.80 ± 4.67 mm, in male and female subjects, respectively. The intraclass correlation coefficients of the PL lengths obtained by the three specialists were greater than 0.997. This MRI technique provides highly stable and repeatable in vivo data of PL and ACL geometry relevant to ACL reconstruction surgery with PL grafts.

The predictive value of the prealbumin-to-fibrinogen ratio in patients with acute pancreatitis

OBJECTIVE

Early identification of severe acute pancreatitis (SAP) progression is important in acute pancreatitis (AP) treatment. The Ranson, APACHE II and CTSI systems are difficult to use and exhibit limited predictive value. Prealbumin and fibrinogen are acute phase reactants generally used to assess the nutritional statuses and coagulation functions of AP patients, respectively. Here, we explored the value of the combination of these two markers for evaluating AP severity and prognosis.

METHODS

One hundred and sixty-nine AP patients, including mild AP (MAP) (n = 101) and severe AP (SAP) patients (n = 68), were enrolled. Their Ranson, APACHE II and CTSI scores, routine laboratory test results, and prealbumin and fibrinogen levels were determined after admission. Multivariate regression analysis was performed to determine the independent predictors of AP severity. ROC curves were generated to determine the suitabilities of prealbumin and fibrinogen levels and the above-mentioned scores for SAP prediction.

RESULTS

The SAP patients exhibited higher scores, white blood cell counts, CRP and fibrinogen levels but lower calcium, prealbumin levels and prealbumin/fibrinogen ratio than the MAP patients (p < 0.05). The multivariate regression analysis demonstrated that the prealbumin/fibrinogen ratio was a good predictor of severity and outperformed CRP. The prealbumin/fibrinogen ratio was correlated with CRP, hospitalisation length and complication occurrence in SAP. The ROC curve analyses showed that the prealbumin/fibrinogen ratio exhibited superior sensitivity, specificity, PPV and NPV for SAP prediction over the scoring systems. With a cut-off of 31.70 mg/g, the sensitivity, specificity, PPV and NPV were 76.5%, 94.1%, 89.6% and 85.6%, respectively.

CONCLUSIONS

The prealbumin/fibrinogen ratio is a promising predictor of AP severity and prognosis.

Prevention of acute liver allograft rejection by IL-10-engineered mesenchymal stem cells

Hepatic allograft rejection remains a challenging problem, with acute rejection episode as the major barrier for long-term survival in liver transplant recipients. To explore a strategy to prevent allograft rejection, we hypothesized that mesenchymal stem cells (MSCs) genetically engineered with interleukin-10 (IL-10) could produce beneficial effects on orthotopic liver transplantation (OLT) in the experimental rat model. Syngeneic MSCs transduced with IL-10 were delivered via the right jugular vein 30 min post-orthotopic transplantation in the rat model. To evaluate liver morphology and measure cytokine concentration, the blood and liver samples from each animal group were collected at different time-points (3, 5 and 7 days) post-transplantation. The mean survival time of the rats treated with MSCs-IL-10 was shown to be much longer than those treated with saline. According to Banff scheme grading, the saline group scores increased significantly compared with those in the MSCs-IL-10 group. Retinoid acid receptor-related orphan receptor gamma t (RORγt) expression was more increased in the saline group compared to those in the MSCs-IL-10 group in a time-dependent manner; forkhead box protein 3 (FoxP3) expression also decreased significantly in the saline group compared with those in the MSCs-IL-10 group in a time-dependent manner. The expression of cytokines [IL-17, IL-23, IL-6, interferon (IFN)-γ and tumour necrosis factor (TNF)-α] in the saline groups increased significantly compared with the time-point-matched MSCs-IL-10 group, whereas cytokine expression of (IL-10, TGF-β1) was deceased markedly compared to that in the MSCs-IL-10 group. These results suggest a potential role for IL-10-engineered MSC therapy to overcome clinical liver transplantation rejection.

Beclin 1 and autophagy are required for the tumorigenicity of breast cancer stem-like/progenitor cells

Malignant breast tissue contains a rare population of multi-potent cells with the capacity to self-renew; these cells are known as cancer stem-like cells (CSCs) or tumor-initiating cells. Primitive mammary CSCs/progenitor cells can be propagated in culture as floating spherical colonies termed ‘mammospheres'. We show here that the expression of the autophagy protein Beclin 1 is higher in mammospheres established from human breast cancers or breast cancer cell lines (MCF-7 and BT474) than in the parental adherent cells. As a result, autophagic flux is more robust in mammospheres. We observed that basal and starvation-induced autophagy flux is also higher in aldehyde dehydrogenase 1-positive (ALDH1⁺) population derived from mammospheres than in the bulk population. Beclin 1 is critical for CSC maintenance and tumor development in nude mice, whereas its expression limits the development of tumors not enriched with breast CSCs/progenitor cells. We found that decreased survival in autophagy-deficient cells (MCF-7 Atg7 knockdown cells) during detachment does not contribute to an ultimate deficiency in mammosphere formation. This study demonstrates that a prosurvival autophagic pathway is critical for CSC maintenance, and that Beclin 1 plays a dual role in tumor development.

Fetal muscle development, mesenchymal multipotent cell differentiation, and associated signaling pathways

Enhancing muscle growth while reducing fat accumulation improves the efficiency of animal production. The fetal stage is crucial for skeletal muscle development. Fetal muscle development involves myogenesis, adipogenesis, and fibrogenesis from mesenchymal multipotent cells (MC), which are negatively affected by maternal nutrient deficiencies. Enhancing myogenesis increases the lean-to-fat ratio of animals, enhancing intramuscular adipogenesis increases intramuscular fat that is indispensible for the superior eating properties of meat because fat is the major contributor to meat flavor. The promotion of fibrogenesis leads to the accumulation of connective tissue, which contributes to the background toughness of meat and is undesirable. Thus, it is essential to regulate MC differentiation to enhance lean growth and improve meat quality. To date, our understanding of mechanisms regulating the lineage commitment of MC is limited. In this review, we first discuss the impact of maternal nutrient deficiency on fetal development, offspring body composition, and meat quality. Because maternal nutrition affects fetal muscle through altering MC differentiation, we then review several important extracellular morphogens regulating MC differentiation, including hedgehog, Wingless and Int (Wnt), and bone morphogenic proteins. Possible involvement of epigenetic modifications associated with histone deacetylases class IIa and histone acetyltransferase, p300, in MC differentiation is also discussed.

Tenuifolin, an extract derived from tenuigenin, inhibits amyloid-beta secretion in vitro

AIM

Previous studies have shown that tenuigenin, a crude extract of Polygala tenuifolia Willd. that is commonly used in traditional Chinese herbal medicine for memory loss, can reduce the secretion of Abeta from cultured cells. However, the mechanism underlying this effect and the active compound derived from tenuigenin is unknown. In this study, a purified component of tenuigenin, tenuifolin, was examined and revealed to be an effective compound in vitro.

METHODS

Abeta secretion from three sets of COS-7 cells, each carrying a plasmid expressing a different form of APP was examined following the treatment with tenuifolin. Initially, tenuifolin was determined to have no inherent toxicity to either the transfected or wild type cells at the effective concentrations. Cells were then treated with 0.5-2.0 microg mL(-1) tenuifolin for 12 h and their media were examined via an ELISA for Abeta1-40 and Abeta-42.

RESULTS

We found that treatment with 2.0 microg mL(-1) tenuifolin significantly decreased Abeta secretion from COS-7 cells without altering the ratio of Abeta1-40 and Abeta-42. This effect is most probably due to inhibition of the beta-site APP cleaving enzyme as Abeta secretion was not inhibited from cells expressing the C99 fragment.

CONCLUSION

Tenuifolin is an effective compound from tenuigenin. We believe that this finding should lead the way for future experiments to determine the exact mechanism for tenuifolin's effect on Abeta secretion.

Long-term estradiol deprivation in breast cancer cells up-regulates growth factor signaling and enhances estrogen sensitivity

Deprivation of estrogen causes breast tumors in women to adapt and develop enhanced sensitivity to this steroid. Accordingly, women relapsing after treatment with oophorectomy, which substantially lowers estradiol for a prolonged period, respond secondarily to aromatase inhibitors with tumor regression. We have utilized in vitro and in vivo model systems to examine the biologic processes whereby long-term estradiol deprivation (LTED) causes cells to adapt and develop hypersensitivity to estradiol. Several mechanisms are associated with this response, including up-regulation of estrogen receptor-alpha (ERalpha) and the MAP kinase, phosphoinositol 3 kinase (PI3-K) and mammalian target of rapamycin (mTOR) growth factor pathways. ERalpha is four- to tenfold up-regulated and co-opts a classical growth factor pathway using Shc, Grb-2 and Sos. This induces rapid non-genomic effects which are enhanced in LTED cells. The molecules involved in the non-genomic signaling process have been identified. Estradiol binds to cell membrane-associated ERalpha, which physically associates with the adaptor protein Shc, and induces its phosphorylation. In turn, Shc binds Grb-2 and Sos, which result in the rapid activation of MAP kinase. These non-genomic effects of estradiol produce biologic effects as evidenced by Elk-1 activation and by morphologic changes in cell membranes. Additional effects include activation of the PI3-K and mTOR pathways through estradiol-induced binding of ERalpha to the IGF-I and epidermal growth factor receptors. A major question is how ERalpha locates in the plasma membrane since it does not contain an inherent membrane localization signal. We have provided evidence that the IGF-I receptor serves as an anchor for ERalpha in the plasma membrane. Estradiol causes phosphorylation of the adaptor protein, Shc and the IGF-I receptor itself. Shc, after binding to ERalpha, serves as the 'bus' which carries ERalpha to Shc-binding sites on the activated IGF-I receptors. Use of small inhibitor (si) RNA methodology to knockdown Shc allows the conclusion that Shc is needed for ERalpha to localize in the plasma membrane. In order to abrogate growth factor-induced hypersensitivity, we have utilized a drug, farnesylthiosalicylic acid, which blocks the binding of GTP-Ras to its membrane acceptor protein, galectin 1, and reduces the activation of MAP kinase. We have also shown that this drug is a potent inhibitor of mTOR as an additional mechanism of inhibition of cell proliferation. The concept of 'adaptive hypersensitivity' and the mechanisms responsible for this phenomenon have important clinical implications. The efficacy of aromatase inhibitors in patients relapsing on tamoxifen could be explained by this mechanism and inhibitors of growth factor pathways should reverse the hypersensitivity phenomenon and result in prolongation of the efficacy of hormonal therapy for breast cancer.