Floating-Point Approximation Enabling Cost-Effective and High-Precision Digital Implementation of FitzHugh-Nagumo Neural Networks

The study of neuron interactions and hardware implementations are crucial research directions in neuroscience, particularly in developing large-scale biological neural networks. The FitzHugh-Nagumo (FHN) model is a popular neuron model with highly biological plausibility, but its complexity makes it difficult to apply at scale. This paper presents a cost-saving and improved precision approximation algorithm for the digital implementation of the FHN model. By converting the computational data into floating-point numbers, the original multiplication calculations are replaced by adding the floating-point exponent part and fitting the mantissa part with piecewise linear. In the hardware implementation, shifters and adders are used, greatly reducing resource overhead. Implementing FHN neurons by this approximation calculations on FPGA reduces the normalized root mean square error (RMSE) to 3.5% of the state-of-the-art (SOTA) while maintaining a performance overhead ratio improvement of 1.09 times. Compared to implementations based on approximate multipliers, the proposed method achieves a 20% reduction in error at the cost of a 2.8% increase in overhead.This model gained additional biological properties compared to LIF while reducing the deployment scale by only 9%. Furthermore, the hardware implementation of nine coupled circular networks with eight nodes and directional diffusion was carried out to demonstrate the algorithm's effectiveness on neural networks. The error decreased to 60% compared to the single neuron of the SOTA. This hardware-friendly algorithm allows for the low-cost implementation of high-precision hardware simulation, providing a novel perspective for studying large-scale, biologically plausible neural networks.

Bronchiolar adenoma/ciliated muconodular papillary tumour: advancing clinical, pathological, and imaging insights for future perspectives

Bronchiolar adenoma/ciliated muconodular papillary tumour (BA/CMPT) is a benign peripheral lung tumour composed of bilayered bronchiolar-type epithelium containing a continuous basal cell layer; however, the similarities in imaging and tissue biopsy findings at histopathology between BA/CMPT and malignant tumours, including lung adenocarcinoma, pose significant challenges in accurately diagnosing BA/CMPT preoperatively. This difficulty in differentiation often results in misdiagnosis and unnecessary overtreatment. The objective of this article is to provide a comprehensive and systematic review of BA/CMPT, encompassing its clinical manifestations, pathological basis, imaging features, and differential diagnosis. By enhancing healthcare professionals' understanding of this disease, we aim to improve the accuracy of preoperative BA/CMPT diagnosis. This improvement is crucial for the development of appropriate therapeutic strategies and the overall improvement of patient prognosis.

Factors associated with nocturnal and diurnal glycemic variability in patients with type 2 diabetes: a cross-sectional study

PURPOSE

There is little information on factors that influence the glycemic variability (GV) during the nocturnal and diurnal periods. We aimed to examine the relationship between clinical factors and GV during these two periods.

METHODS

This cross-sectional study included 134 patients with type 2 diabetes. 24-h changes in blood glucose were recorded by a continuous glucose monitoring system. Nocturnal and diurnal GV were assessed by standard deviation of blood glucose (SDBG), coefficient of variation (CV), and mean amplitude of glycemic excursions (MAGE), respectively. Robust regression analyses were performed to identify the factors associated with GV. Restricted cubic splines were used to determine dose-response relationship.

RESULTS

During the nocturnal period, age and glycemic level at 12:00 A.M. were positively associated with GV, whereas alanine aminotransferase was negatively associated with GV. During the diurnal period, homeostatic model assessment 2-insulin sensitivity (HOMA2-S) was positively associated with GV, whereas insulin secretion-sensitivity index-2 (ISSI2) was negatively associated with GV. Additionally, we found a J-shape association between the glycemic level at 12:00 A.M. and MAGE, with 9.0 mmol/L blood glucose level as a cutoff point. Similar nonlinear associations were found between ISSI2 and SDBG, and between ISSI2 and MAGE, with ISSI2 value of 175 as a cutoff point.

CONCLUSION

Factors associated with GV were different between nocturnal and diurnal periods. The cutoff points we found in this study may provide the therapeutic targets for beta-cell function and pre-sleep glycemic level in clinical practice.

Achieving High Core Neuron Density in a Neuromorphic Chip Through Trade-off Among Area, Power Consumption, and Data Access Bandwidth

As a crucial component of neuromorphic chips, on-chip memory usually occupies most of the on-chip resources and limits the improvement of neuron density. The alternative of using off-chip memory may result in additional power consumption or even a bottleneck for off-chip data access. This article proposes an on- and off-chip co-design approach and a figure of merit (FOM) to achieve a trade-off between chip area, power consumption, and data access bandwidth. By evaluating the FOM of each design scheme, the scheme with the highest FOM (1.085× better than the baseline) is adopted to design a neuromorphic chip. Deep multiplexing and weight-sharing technologies are used to reduce on-chip resource overhead and data access pressure. A hybrid memory design method is proposed to optimize on- and off-chip memory distribution, which reduces on-chip storage pressure and total power consumption by 92.88% and 27.86%, respectively, while avoiding the explosion of off-chip access bandwidth. The co-designed neuromorphic chip with ten cores fabricated under standard 55 nm CMOS technology has an area of 4.4 mm 2 and a core neuron density of 4.92 K/mm 2, an improvement of 3.39  ∼ 30.56× compared with previous works. After deploying a full-connected and a convolution-based spiking neural network (SNN) for ECG signal recognition, the neuromorphic chip achieves 92% and 95% accuracy, respectively. This work provides a new path for developing high-density and large-scale neuromorphic chips.

Dual-mode sensing chip for photoelectrochemical and electrochromic visual determination of deoxynivalenol mycotoxin

The successful development of a dual-mode sensing chip for deoxynivalenol (DON) detection using photoelectrochemical (PEC) and electrochromic visualization techniques is reported. By laser etching technology, different functional areas, including the photoanode, the cathode, and the electrochromic area, are fabricated on indium tin oxide (ITO) glass. Then, these three areas are further respectively modified with PEC active materials, platinum nanoparticles, and Prussian blue. Under light illumination, photocurrents generate between the photoanode and the cathode due to the separation of photo-induced electrons and holes in the TiO2/3DNGH material. Meanwhile, the photo-induced electrons are transferred to Prussian blue on the visualization area, which will be reduced to colorless Prussian white. The binding of DON molecules and aptamers can promote electron transfer and reduce the recombination of electrons and holes, allowing for simultaneous quantitative detection of DON using either the photocurrent or color change. The sensor chip has a broad detection range of DON concentrations of 1 fg⋅mL-1 to 100 pg⋅mL-1 in the PEC mode with the limit of detection of 0.37 fg⋅mL-1, and 1 to 250 ng⋅mL-1 in the visualization mode with the limit of detection of 0.51 ng⋅mL-1. This portable dual-mode sensor chip can be used in both laboratory and field settings without the need for specialized instruments, making it a powerful tool for ensuring food safety. At the same time, the analysis of the standard addition method of the actual sample by using the sensor chip shows that, in the PEC mode, the recoveries of the dual-mode aptasensor chip were 91.3 to 99.0% with RSD values of 1.73~2.55%, and in visualization mode, the recoveries of the dual-mode aptasensor chip were 99.2 to 102.0% with RSD values of 1.00~6.21%, which indicate good accuracy and reproducibility.

[Construction of a schistosomiasis transmission risk assessment system in Wuhan City based on analytic hierarchy process]

OBJECTIVE

To construct a schistosomiasis transmission risk assessment system in Wuhan City and preliminary evaluate its application effect, so as to promote the rational allocation of schistosomiasis control resources and accelerate the progress towards schistosomiasis elimination.

METHODS

The schistosomiasis risk assessment indicators were collected through referring schistosomiasis surveillance data of Wuhan City from 2014 to 2020, literature review and expert interviews. Indicators within each criterion and sub-criterion were screened using the Delphi method, and a hierarchical structure model was created based on analytic hierarchy process. Quantitative assignment of each indicator was conducted according to relative importance, and the weight and combination weight of each criterion were calculated in each analytic hierarchy framework to create a schistosomiasis transmission risk assessment system, which was used for the schistosomiasis transmission risk assessment in 12 national schistosomiasis surveillance sites in Wuhan City.

RESULTS

A three-level schistosomiasis transmission risk assessment system was preliminarily constructed, which included a target layer, 5 criterion layers and 21 sub-criterion layers. Of all indicators in the criterion layer, transmission route had the highest weight (0.433), followed by source of Schistosoma japonicum infection (0.294); and among all indicators in the sub-criterion layer, S. japonicum infection in Oncomelania hupensis and sentinel mice had the highest combination weight (0.125), followed by prevalence of S. japonicum infection in humans (0.091) and bovines (0.053), snail control by chemical treatment (0.049), positive rate of inquiry examinations (0.048), allocation of schistosomiasis control professionals (0.045), and areas of submerged snail-infested settings (0.041). Of the 12 national schistosomiasis surveillance sites in Wuhan City, there were 5 sites with weights of > 0.8, 4 sites with weights of 0.6 to 0.8, and 3 sites with weights of < 0.6 in 2020.

CONCLUSIONS

A schistosomiasis transmission risk assessment system has been constructed based on analytic hierarchy process in Wuhan City, which may provide a evidence-based basis for health resource allocation and decision-making for schistosomiasis control.

Effect of clay supplementation on growth performance of broiler chickens: a systematic review and meta-analysis

1. This review assessed the effect of dietary clay supplementation as a drug and toxin adsorbent on broiler growth performance as a meta-analysis.2. A total of 33 eligible studies were included in the present study after identification and evaluation from online databases. Standardised mean differences (SMD) with corresponding 95% confidence intervals were computed with a fixed-effects model.3. The results indicated that clay supplementation significantly improved broiler daily gain (P < 0.001) and feed conversion ratio (P < 0.001), but did not affect feed intake (P = 0.954). Results of subgroup analysis showed that zeolite clay had the most stable medium improvement effect on FCR, while kaolin had a large effect. In addition, male broilers and Cobb or Ross broilers were more sensitive to the addition of clay, and the best supplemental levels, in general, were 10 g/kg to 30 g/kg.4. Meta-regression analysis showed that clay supplemental level and sex of broilers may be important factors in the effect of clay on ADG and FCR of broilers, respectively. The sensitivity analysis showed high stability of the results and no significant publication bias was found with funnel plot analysis and Egger's or Begg's test (P > 0.05).5. In conclusion, an appropriate addition level is a prerequisite for effective clay application. Kaolin and zeolite clays seem to be more suitable for enhancing broiler growth performance, and the value of clay is amplified in specific broiler breeds.

Evaluation of a medical education policy with compulsory rural service in China

Background

Since 2010, China has implemented a national programme to train general practitioners for rural areas. The programme enrolled medical students with a rural background who signed a contract for 6 years' compulsory rural service after graduation. China is transitioning its national COVID-19 strategies in view of the features of coronavirus Omicron variant, the vaccination coverage, and the need for socioeconomic development. Strengthening primary health care, especially the health workforce in rural areas, should be an important consideration during the policy transition. This study aims to evaluate the implementation process of enrolling medical students in the programme, their willingness to work in the rural settings and their actual job choice after graduation.

Methods

The study chose four medical universities in central and western China. A total of 2,041 medical graduates who have signed a contract for compulsory rural service and 1,576 medical graduates enrolled "as usual" (no compulsory rural service) were recruited in five campaigns-every June from 2015 to 2019. A survey was conducted 1 week before their graduation ceremony.

Results

The top three reasons for choosing this programme were: a recommendation of a family member or teacher, a guaranteed job after graduation and the waiver of the tuition fee. 23.0-29.7% of the study participants were not familiar with the policy details. 39.1% of the medical students signed a contract with a county other than that of their hometown. Medical graduates on the compulsory rural service programme had very low willingness (1.9%) to work in rural areas but 86.1% of them actually worked at township health centers. In contrast, the willingness to work at township health centers was 0.2% for the comparison group (medical graduates without the contract), and their actual job choice at township health centers was 0%.

Conclusions

Although the well-trained medical graduates on the compulsory rural service programme have low willingness to work in the township health centers, 86.1% of them choose to do so following their contract. This programme will strengthen the primary health workforce to deal with the increasing disease burden as China is transitioning its national COVID-19 strategies.

Self-compression of stimulated Raman backscattering by a flying focus

The regime of self-compression has been proposed for plasma-based backward Raman amplification upon a flying focus. By using a pumping focus moving with a speed equal to the group velocity of stimulated Raman backscattering (SRBS), only a short part of SRBS which always synchronizes with the flying focus can be amplified. Therefore, instead of a short pulse, plasma noise or a long pulse can seed the BRA amplifiers. Here we demonstrate the regime by 2D particle-in-cell simulations, showing that the pump pulse is compressed from 26 ps to 116 fs, with an output amplitude comparable with the case of a well-synchronized short seed. As only one laser pulse is used in the simulation, the results present a significant path to simplify the Raman amplifiers.

[A multi-center, randomized controlled study on the effect of Saccharomyces boulardii combined with triple therapy for the initial eradication of Helicobacter pylori infection]

Objective: To assess the efficacy and safety of Saccharomyces boulardii (S. boulardii) in combination with triple therapy as a first-line regimen for the eradication of Helicobacter pylori (H. pylori) in non-ulcer dyspepsia (NUD) patients. Methods: A total of 497 Helicobacter pylori-positive patients who underwent gastroscopy and diagnosed with NUD were enrolled from June 2018 to January 2020 in 9 medical centers across China. Participants were segmentedly randomly divided into 3 groups. Patients in group A received S. boulardii for 14 days and triple therapy for 10 days, while patients in group B received bismuth quadruple group for 10 days, and patients in group C received triple therapy for 10 days. The H. pylori status was determined by the ¹³C-urea breath test on the 44th day of the treatment. Symptom improvement and adverse reactions were assessed on the 14th and 44th day. Results: There were 229 males and 268 females in all 497 patients enrolled. They were aged 18-69 (46.1±11.8) years and 472 of them (158 cases in group A, 159 cases in group B, and 155 cases in group C) completed the trial. The intention-to-treat (ITT) eradication rates in patients in patients A, B and C were 77.8% (126/162), 80.1% (137/171) and 65.2% (107/164) respectively, and per protocol-based (PP) eradication rates were 79.7% (126/158), 86.2% (137/159) and 69.0% (107/155) respectively. The differences were statistically significant in ITT and PP analysis among 3 groups (ITT: χ²=11.14, P<0.01; PP: χ²=13.86, P<0.01). There was no significant difference between eradication rates of two quadruple therapys(all P>0.05), but both of them were significantly higher than that of standard triple therapy (both P<0.05). Statistics revealed that both quadruple therapys led to significantly higher symptom improvement of belching compared with that of standard triple therapy in day 14 (P<0.05). The relief of abdominal distension and belching symptom scores of group A were significantly higher than those of group C in day 44(all P<0.05). There was no serious adverse event reported. The incidence of diarrhea in group A was significantly lower than those in the other two groups (both P<0.05). Conclusions: The combination of S. boulardii and triple therapy can achieve a better eradication effect on H. pylori infection with NUD, and has advantages in symptom relief and safety.

Hierarchical Regulation of LaMnO3 Dual-Pathway Strategy for Excellent Room-Temperature Organocatalytic Oxidation Performance

The performance-enhancing strategy of a single pathway for perovskite has been widely studied. In this work, the dual-pathway strategy of A-site Ce substitution and nitric acid selective dissolution was proposed. The catalytic oxidation performance of LaMnO₃ exhibits the characteristic of hierarchical regulation, that is, a steplike improvement, which avoids the limitation of performance improvement of the single pathway. The B-site Mn with catalytic activity was in situ reconstituted on the surface to build a Mn-rich surface. The obtained sdLa_0.7Ce_0.3MnO₃ has the advantages of good oxygen mobility, high Mn⁴⁺/Mn³⁺ molar ratio, and large specific surface area, and this material showed excellent catalytic oxidation performance for organics, which can realize colorimetric chemical oxygen demand detection at room temperature. Here, Ce substitution improved the oxidation capacity by improving the oxygen mobility and the ratio of Mn⁴⁺/Mn³⁺, and further nitric acid treatment not only accelerated the in situ reconstruction of B-site Mn but also increased the specific surface area.

[Progress in pulmonary enteric adenocarcinoma]

Pulmonary enteric adenocarcinoma (PEAC), as a rare histologic subtype of primary lung adenocarcinoma, is defined as an adenocarcinoma in which the enteric component exceeds 50%. It is named after its shared morphological and immunohistochemical features with colorectal cancer. While with such similarity, the differential diagnosis of PEAC and lung metastatic colorectal cancer is a great challenge in the clinic. PEAC may originate from the intestinal metaplasia of respiratory basal cells stimulated by risk factors such as smoking. Current studies have found that KRAS is a relatively high-frequency mutation gene, and other driver gene mutations are rare. In terms of immunohistochemistry, in pulmonary enteric adenocarcinoma, the positive rate was 88.2% (149/169) for CK7, 78.1% (132/169) for CDX2, 48.2% (82/170) for CK20 and 38.8% (66/170) for TTF1. As for clinical features, the average age of onset for pulmonary enteric adenocarcinoma was 62 years, male patients accounted for 56.5% (35/62), smokers accounted for 78.8% (41/52), and 41.4% (24/58) of the primary lesion was located in the upper lobe of the right lung. In terms of treatment, conventional non-small cell lung cancer (NSCLC) regimens rather than colorectal cancer regimens are now recommended. There is still an urgent need for more basic and clinical research, in-depth exploration of its molecular feature and pathogenesis from the level of omics and other aspects, to help diagnosis and differential diagnosis, and find the optimal chemotherapy regimen, possibly effective targeted therapy and even immunotherapy.

MiR-4282 is a tumor-suppressor gene for preventing metastasis of epithelial ovarian cancer by negatively regulating MIER1

OBJECTIVE

To elucidate the biological role of miR-4282 in influencing metastasis of epithelial ovarian cancer (EOC) by regulating MIER1.

PATIENTS AND METHODS

MiR-4282 expressions in 45 cases of EOC specimens and normal controls were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between miR-4282 and clinical features in EOC patients, including pathological indicators and overall survival, was analyzed. After intervening miR-4282 level in SKOV3 and 3AO cells by plasmid transfection, changes in migratory and invasive abilities were determined by transwell assay and wound healing assay. The target gene of miR-4282 was observed by Dual-Luciferase reporter assay, followed by exploration of its involvement in EOC progression via rescue experiments.

RESULTS

MiR-4282 was downregulated in EOC specimens than normal controls. EOC patients expressing low level of miR-4282 had higher incidences of lymphatic metastasis and distant metastasis, as well as worse prognosis than those overexpressing miR-4282. Overexpression of miR-4282 in SKOV3 cells weakened metastatic ability, and conversely, knockdown of miR-4282 in 3AO cells yielded the promotive trends. MIER1 was confirmed to be the target gene binding miR-4282, which was highly expressed in EOC specimens. MIER1 was able to reverse the regulatory effect of miR-4282 on EOC cell metastasis.

CONCLUSIONS

Lowly expressed miR-4282 in EOC specimens is closely linked to the incidence of metastasis and overall survival. MiR-4282 prevents EOC metastasis by a negative regulation on MIER1.

High-Throughput Detection of Multiple Contaminants Based on Portable Photoelectrochromic Sensor Chip

With the increasing concerns about the environment and food safety, it is necessary to develop portable, low-cost, and high-throughput biosensors for the simultaneous detection of multiple contaminates. However, traditional photoelectrochemical (PEC) biosensors lack the ability of multiplexed assays due to the inherent mechanism limitation. Also, specialized instruments are necessary for most PEC biosensors. In this work, a portable high-throughput sensor chip has been successfully developed. By introducing electrochromic materials, the detection is based on color change instead of electric signals, which reduces the limitation of instruments. This designed sensor chip is composed of three parallel sensing channels fabricated by laser etching. Each channel is modified with TiO₂/3D-g-C₃N₄ composites with excellent PEC activity and electrochromic material Prussian blue (PB). Under light illumination, photoinduced electrons generated by TiO₂/3D-g-C₃N₄ are injected into PB, and blue PB is reduced to colorless Prussian white. Three organic contaminates, ochratoxin A, lincomycin, and edifenphos, can be simultaneously detected because the binding of these molecules with aptamers affects the electron transfer and the corresponding color changes. This portable and high-throughput sensor chip provides a convenient choice for multiplexed assays with good sensitivity and accuracy.

Early outcomes of a rural-oriented physician education programme against rural physician shortages in Guangxi province: a prospective cohort study

OBJECTIVES

This study aimed to investigate early outcomes of one of the first medical undergraduate education programmes with a goal of mitigating severe rural physician shortages in China, which was developed by Guangxi Medical University (GXMU) and was called the Rural-oriented Free Tuition Medical Education (RTME)-GXMU programme.

DESIGN

A prospective cohort study comprising a baseline investigation and follow-up research was conducted to dynamically observe the evolution of the RTME-GXMU programme that began since 2010.

PARTICIPANTS

380 RTME-GXMU graduates and 383 non-RTME-GXMU graduates from GXMU who completed trainings between 2015 and 2018 were recruited in the baseline investigation. Among them, 285 RTME-GXMU and 283 non-RTME-GXMU graduates responded to the follow-up research.

MAIN OUTCOME MEASURES

Graduate practice location, registered specialty, passing rate of the National Medical Licensing Examination (NMLE), specialty of residency programme and contract compliance for the RTME-GXMU graduates.

RESULTS

By the end of 2018, 100% of the 2015 RTME-GXMU graduates enrolled in this study practised in rural township health centres and registered themselves as general practitioners (GPs). All the RTME-GXMU graduates had completed or were attending residency programmes of general practice (GP). The above data stood in stark contrast to that of the non-RTME-GXMU graduates among whom as few as 1.06% worked in rural areas, 2.13% registered as GPs and less than 3% chose GP residency programmes. No significant differences were detected on passing rates of the NMLE between the two groups. Only one RTME-GXMU graduate broke the contract and dropped off the programme.

CONCLUSIONS

The RTME-GXMU programme has achieved encouraging early outcomes. Reduced entry score and proper usage of urban primary care institutions are two key approaches contributing to these positive early results.

Nanoparticles-doped induced defective ZIF-8 as the novel cathodic luminophore for fabricating high-performance electrochemiluminescence aptasensor for detection of omethoate

Although the use of omethoate (OMT) for pests control is enormously economically beneficial for agricultural production, the high toxicity of OMT to nontarget organisms has resulted in the contamination of soil, river water, and food materials. Developing sensitive and convenient techniques to detect OMT residues is vital to society. Electrochemiluminescence (ECL) is a powerful analytical tool and has been widely applied in biosensors. To boost the co-reaction efficiency and ECL intensity, we introduced defective ZIF-8 as the novel cathodic luminophore. At the same time, defect generated by the doping of MoTe₂ nanoparticles into ZIF-8 could easily electrocatalytic reduce the co-reactor S₂O₈^2- to SO₄^•-. Hence, based on the catalysis of defective ZIF-8, the ECL intensity of MoTe₂/ZIF-8 nanocomposites is much higher than both ZIF-8 and MoTe₂ nanoparticles. By integration of as-prepared materials with specificity omethoate aptamer, the ECL sensor showed a broad linear range (10^-10 g L^-1 and 10^-5 g L^-1) and a comparatively low detection limit (3.3 × 10^-11 g L^-1). Besides, the ECL aptasensor appeared a good practical performance to detect potato and spinach extraction samples, which proposed a promising guideline for developing ECL aptasensors with high efficiency.

Rapid Potentiometric Detection of Chemical Oxygen Demand Using a Portable Self-Powered Sensor Chip

Chemical oxygen demand (COD) is an important indicator of organic pollutants in water bodies. Most of the present testing methods have the disadvantages of having complicated steps, being time-consuming, and using toxic and hazardous substances. In this work, rapid potentiometric detection of chemical oxygen demand (COD) using a portable self-powered sensor chip was successfully developed. The indium tin oxide (ITO) electrode was etched by laser, and the photocatalytic materials TiO₂/CuS and Pt were modified onto the photoanode and the cathode to prepare the sensor chip. Based on the principle of photocatalytic degradation, organic pollutants can be oxidized by TiO₂/CuS, and the concentration will affect the generated voltage. The quantitative detection of COD in the range of 0.05-50 mg/L can be rapidly achieved within 5 min by a miniature device. Besides good portability and sensitivity, the proposed sensor also has the advantages of environmental friendliness and ease of use, which is an ideal choice for the on-site detection of water pollution.

[Effect of levothyroxine treatment on pregnancy outcomes in euthyroid women with thyroid autoantibody positive: a Meta-analysis]

Objective: To conduct a systematic review of the association of levothyroxine treatment with pregnancy outcomes in euthyroid women who are thyroid autoantibody positive. Methods: Medline, Excerpta Medica (EMBASE), Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), Wanfang data and VIP database were searched from inception until Jan. 28, 2020. All published randomized controlled trials assessing the association of levothyroxine treatment with pregnancy outcomes in euthyroid women with thyroid autoantibody-positive were included. STATA 11.0 and RevMan 5.3 softwares were used to perform this Meta-analysis. Results: A total of 6 studies met the inclusion criteria, with 2 188 women randomized. Meta-analysis showed that there was no significantly association between miscarriage (OR=0.85, 95%CI: 0.65-1.11, P=0.234) and preterm birth (OR=0.79, 95%CI: 0.54-1.16, P=0.224) with levothyroxine treatment. Conclusions: Levothyroxine therapy could not reduce the risk of miscarriage and preterm birth in euthyroid women with thyroid autoantibody-positive. Therefore, levothyroxine should be used with caution for these pregnant women.

Genome-wide Analyses Identify a Novel Risk Locus for Nonsyndromic Cleft Palate

The 3 major subphenotypes observed in patients with nonsyndromic orofacial clefts (NSOFCs) are nonsyndromic cleft lip only (NSCLO), nonsyndromic cleft lip with palate (NSCLP), and nonsyndromic cleft palate only (NSCPO). However, the genetic architecture underlying NSCPO is largely unknown. Here we performed a 2-stage genome-wide association study (GWAS) on NSCPO and replication analyses of selected variants in other NSOFCs from the Chinese Han population. We identified a novel locus (15q24.3) and a known locus (1q32.2) where variants in or near the gene reached genome-wide significance (2.80 × 10^-13 < P < 1.72 × 10^-08) in a test for association with NSCPO in a case-control design. Although a variant from 15q24.3 was found to be significantly associated with both NSCPO and NSCLP, the direction of estimated effects on risk were opposite. Our functional annotation of the risk alleles within 15q24.3 coupled with previously established roles of the candidate genes within identified risk loci in periderm development, embryonic patterning, and/or regulation of cellular processes supports their involvement in palate development and the pathogenesis of cleft palate. Our study advances the understanding of the genetic basis of NSOFCs and provides novel insights into the pathogenesis of NSCPO.

CAPABILITIES OF THE ARADOS-WG03 REGIONAL NETWORK FOR LARGE-SCALE RADIOLOGICAL AND NUCLEAR EMERGENCY SITUATIONS IN ASIA

In 2015, the Asian Radiation Dosimetry Group established a regional network of biological dosimetry laboratories known as the ARADOS-WG03 (Working Group 03; Biological Dosimetry). A survey was conducted in 2017 to evaluate the capabilities and capacities of the participating laboratories for emergency preparedness and responses in large-scale nuclear and/or radiological incidents. The results of this survey were identified and assessed. The data provide important information on the current state of emergency cytogenetic biological dosimetry capabilities in the Asian region.

MiR-34a-5p/PD-L1 axis regulates cisplatin chemoresistance of ovarian cancer cells

Ovarian cancer is the most lethal gynecologic malignancy in women with an increasing number of cases worldwide. Chemoresistance is the main obstacle for ovarian cancer treatment during clinical therapy. Previous studies found that programmed cell death 1 ligand 1 (PD-L1) was associated with chemoresistance of cancer. However, there were little reports about the function of PD-L1 involved in chemoresistance of ovarian cancer. In our study, cisplatin (DDP)-resistant SKOV3 and A2780 ovarian cancer cell lines (SKOV3/DDP and A2780/DDP) were established. We found that the expression of PD-L1 was increased and miR-34a-5p was decreased in DDP-resistant cells. PD-L1 silencing inhibited chemoresistance of DDP-resistant ovarian cancer cells to DDP, as evidenced by decreased proliferation, G1-phase cell cycle arrest and increased apoptosis. Western blot assay showed that in the presence of DDP, PD-L1 silencing decreased multidrug resistance protein 1 and Cyclin D1 protein levels, whereas increased cleaved-caspase-3 and cleaved-PARP protein levels in these cells. Moreover, we demonstrated that miR-34a-5p negatively regulated the expression of PD-L1 by targeting its 3'-untranslated region. The effects of miR-34a-5p mimic on DDP-treated SKOV3/DDP cells were reversed by the overexpression of PD-L1. Moreover, the tumorigenicity of DDP-resistant ovarian cancer cells in nude mice treated with DDP was attenuated by miR-34a-5p in vivo. The combined data indicate that miR-34a-5p/PD-L1 axis regulates DDP chemoresistance of ovarian cancer cells, providing a deeper insight into the treatment for ovarian cancer.

Association of plasma C-reactive protein with ischaemic stroke: a Mendelian randomization study

BACKGROUND AND PURPOSE

Elevated C-reactive protein (CRP) is associated with an increased risk of ischaemic stroke (IS). However, the causality of this association is uncertain. The aim is to investigate whether genetically raised plasma CRP concentration levels are associated with IS on the basis of the Mendelian randomization method.

METHODS

Based on the National Center for Biotechnology Information single nucleotide polymorphism (SNP) database, the Chinese online genetic database as well as previously published studies, four CRP-associated SNP alleles (rs1130864, rs1205, rs876537 and rs3093059) with minor allele frequency ≥0.15 were selected and the concentration levels of CRP were measured in 378 first-ever IS patients and 613 healthy controls.

RESULTS

Three SNPs were chosen and used as instrumental variables. The adjusted odds ratios (ORs) [95% confidence interval (95% CI)] of IS per addition of the modelled allele were 1.07 (0.79-1.45) for rs876537, 0.99 (0.73-1.35) for rs1205 and 1.08 (0.71-1.65) for rs3093059. The OR (95% CI) of IS for plasma CRP ≥2.0 mg/l was 2.19 (1.06-4.53) compared with <2.0 mg/l. The adjusted OR (95% CI) of IS per genetically predicted 10% higher CRP concentration, based on the three SNPs as the instruments, was 1.02 (0.94-1.11). Furthermore, similar results were obtained with adjusted ORs (95% CI) of 1.00 (0.88-1.13) and 1.04 (0.93-1.16), respectively, for large-artery atherosclerosis and small-artery occlusion per genetically predicted 10% higher CRP concentration.

CONCLUSIONS

This Mendelian randomization study provides no clear support that elevated CRP concentration is causally associated with the risk of IS.

The role of adiponectin gene mediated by NF-κB signaling pathway in the pathogenesis of type 2 diabetes

OBJECTIVE

To investigate the role of adiponectin (ADPN) gene mediated by NF-κB signaling pathway in the pathogenesis of type 2 diabetes (T2DM).

PATIENTS AND METHODS

The levels of expression of ADPN were measured by fluorescence quantitative PCR technology, enzyme-linked immunosorbent assay, Western-blotting and immunohistochemistry in 78 patients with type 2 diabetes.

RESULTS

Compared with the normal population, the levels of expression of ADPN and NF-κB mRNA in the blood of patients with type 2 diabetes were significantly reduced (p < 0.05). The detection of ADPN gene protein expression in normal population and patients with type 2 diabetes by enzyme-linked immunosorbent assay showed that ADPN gene protein expression in type 2 diabetic patients (1.26 ± 0.73) µg/l was significantly lower (p < 0.05) than ADPN gene protein expression of the normal population (3.26 ± 1.25) µg/l. At the same time, the detection of the expression of NF-κB gene showed that the protein expression in type 2 diabetic patients (0.58 ± 0.15) µg/l was significantly lower (p < 0.05) than that in the normal population (1.67 ± 1.04) µg/l. The results of Western-blotting were consistent with the results of enzyme-linked immunosorbent assay. Immunohistochemical results also showed that the percentage of ADPN positive cells in patients with type 2 diabetes (25.47%) was significantly lower (p < 0.05) than that in the normal population (79.47%).

CONCLUSIONS

ADPN gene in the human body can be involved in the pathogenesis of T2DM through the NF-κB signaling pathway.

Oxidative lipoprotein markers predict poor functional outcome in patients with minor stroke or transient ischaemic attack

BACKGROUND AND PURPOSE

Oxidative stress plays an important role in acute ischaemic stroke. However, the association of oxidative lipoprotein markers, including oxidized low-density lipoprotein (oxLDL), oxLDL:high-density lipoprotein (HDL) and oxLDL:low-density lipoprotein (LDL), with functional outcome of minor stroke or transient ischaemic attack (TIA) remains unclear. We aimed to investigate the association between oxidative lipoprotein markers and poor functional outcome in patients with minor stroke or TIA.

METHODS

All patients with minor stroke or TIA were recruited from the Clopidogrel in High-Risk Patients With Acute Non-Disabling Cerebrovascular Events (CHANCE) trial. The poor functional outcome included modified Rankin Scale (mRS) score 2-6 and 3-6 at 90-day and 12-month follow-up. Multivariate logistic regression was used to investigate the associations of oxLDL, oxLDL:HDL and oxLDL:LDL with poor functional outcome.

RESULTS

Among 3019 patients included in this study, the median (interquartile range) oxLDL, oxLDL:HDL and oxLDL:LDL were 13.96 (6.65-28.81), 4.52 (2.08-9.32) and 11.73 (5.27-24.85) μg/dL, respectively. After adjusted for confounding factors, patients in the highest oxLDL quartile had a higher proportion of mRS score 2-6 at 90 days [hazard ratio (HR), 1.78; 95% confidence interval (CI), 1.26-2.52] and 12 months (HR, 1.42; 95% CI, 1.01-1.99), and mRS score 3-6 at 90 days (HR, 1.98; 95% CI, 1.29-3.04) and 12 months (HR, 1.77; 95% CI, 1.09-2.89) when compared with the lowest oxLDL quartile (P < 0.05). Similar results were found for oxLDL:HDL and oxLDL:LDL.

CONCLUSIONS

Higher levels of oxidative lipoprotein markers are independent predictors of poor functional outcome in patients with minor stroke or TIA at 90 days and 12 months.

Role of PCK1 gene on oil tea-induced glucose homeostasis and type 2 diabetes: an animal experiment and a case-control study

Background

Oil tea is a type of traditional tea beverage used for treating various ailments in minority population in Guangxi, China. Our previous study showed oil tea improved glucose and lipid levels in type 2 diabetic mice. Yet, the underling molecular mechanisms are still not understood. This study aimed at assessing the effect of oil tea on glucose homeostasis and elucidating the molecular mechanisms underlying the oil tea-induced antidiabetic effects.

Methods

Twenty seven db/db mice were gavaged with saline, metformin and oil tea for 8 weeks with measurement of biochemical profiles. A real-time² (RT²) profiler polymerase chain reaction (PCR) array comprising 84 genes involved in glucose metabolism was measured and validated by quantitative PCR (qPCR). The association between the candidate genes and type 2 diabetes were further analyzed in a case-control study in the Chinese minority population.

Results

Oil tea treatment facilitated glucose homeostasis by decreasing fasting blood glucose and total cholesterol, and improving glucose tolerance. Suppressing phosphoenolpyruvate carboxykinase 1 (PCK1) expression was observed in the oil tea treatment group and the expression was significantly correlated with fasting blood glucose levels. Target prediction and functional annotation by WEB-based GEne SeT AnaLysis Toolkit (WebGestalt) revealed that PCK1 mainly involved in the glycolysis/gluconeogenesis pathway among the top Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathways. Both rs707555 and rs2071023 in PCK1 were significantly associated with type 2 diabetes in the minority population of Guangxi.

Conclusion

Our findings indicated oil tea improved glucose homeostasis via down-regulation of PCK1 and PCK1 may be a genetic marker for the treatment of type 2 diabetes.

[Genotype distribution of human enteroviruses isolated from swage in Shanghai during year 2013-2014]

Objective: To explore the time and genotype distribution of human enterovirus (HEV) isolated from sewage in Shanghai in 2013-2014. Methods: One sewage sample each was collected from two local sewage plants located in Minhang District and Jiading District on the same day at the day 24-28 of every month from 2013 to 2014. Each sample weighed 1 L. The specimens were concentrated by anionic membrane absorption, eluted with beef extract solution, and then used to inoculate RD, HEp-2, and L20B cell lines. A total of 249 enterovirus strains were isolated from sewage samples during the study period, including 185 non-polio enterovirus (NPEV) and 64 poliovirus (PV) strains, which were identified as vaccine strains. RT-PCR and Sanger sequencing were performed to identify HEV genotypes. Homologous analysis of VP1 sequences was conducted using BioEdit (version 7.0.0). Phylogenetic analysis was performed using the neighbor-joining method based on the alignment of VP1 gene sequences using MEGA (version 4.0.2). Results: Among 185 NPEV strains, 178 strains were successfully sequenced and classified into 15 genotypes, including coxsackievirus group B (CVB) 2, 3, and 5; enteric cytopathic human orphan (ECHO) virus 1, 3, 6, 7, 11, 13, 19, 20, 24, 25, and 30; and coxsackievirus group A 4. CVB5 and ECHO6 genotypes accounted for 33.5% (56 strains) and 24.9% (43 strains) of NPEV isolates, respectively. During the study period, HEV isolates were mainly isolated in summer and autumn in Minhang District. ECHO6 strains were frequently isolated from June 2013 to July 2014. Thereafter, the number of ECHO6 strains gradually reduced in the second half of 2014. CVB5 strains demonstrated scattered distribution from 2013 to the first half of 2014 and gradually increased in the second half of 2014. The distribution of ECHO6 and CVB5 strains in Jiading District was similar to that in Minhang District. In 2013-2014, CVB5 strains comprised C6 and C8 subgenotypes, which belong to two transmission chains and show large differences compared with foreign strains isolated during the same period. ECHO6 strains comprised C6, C8, and D9 subgenotypes, which belong to three transmission chains. Moreover, ECHO6 subgenotype D9 was a dominant subgenotype in Shanghai, with broad geographical distribution both at home and abroad. Conclusion: Poliovirus was identified as a vaccine strain in environmental surveillance from June 2013 to April 2014 in Shanghai. Several transmission strains of ECHO6 and CVB5 were identified, which were the dominant serotypes.

A unique antiphospholipid assay recognizing phospholipid mixture compared with criteria antiphospholipid immunoassays in lupus patients

Background While essential for the classification of antiphospholipid syndrome (APS), anticardiolipin (aCL) assays lack specificity and anti-β2glycoproteinI (anti-β2GPI) assays lack sensitivity in this regard. Our aim was to perform a comparative analysis of the APhL ELISA assay (IgG/IgM) and criteria antiphospholipid (aPL) immunoassays in identifying APS-related clinical manifestations in a large group of patients with systemic lupus erythematosus (SLE). Methods Serum samples from 1178 patients from the Hopkins ( n = 543), LUMINA ( n = 588) and Jamaican SLE cohorts ( n = 47) were examined for IgG/IgM positivity in aCL (in-house), anti-β2GPI (two commercial kits) and APhL (Louisville APL) ELISA assays. Correlation of assay positivity with clinical manifestations and sensitivity, specificity, positive and negative predictive values and likelihood ratios were evaluated. A case series analysis was also performed in patients for whom there was isolated positivity in the specific aPL assays. Results The prevalence of aCL positivity was 34.9%, anti-β2GPI kit A was 22.6%, APhL was 11.5% and anti-β2GPI kit B was 7.6% in the study population. Anti-β2GPI kit B, aCL and APhL assays were correlated with venous thrombosis, while only APhL was significantly correlated with arterial thrombosis and consistently correlated with pregnancy-related morbidity. No significant correlations were noted for anti-β2GPI kit A. Sensitivity was greatest for aCL assays followed by anti-β2GPI kit A, APhL and anti-β2GPI kit B, while specificity was greatest and equal for anti-β2GPI kit B and APhL assays. Conclusions Overall, APhL antibodies, especially IgG, represent a promising biomarker for the classification of APS patients in the context of autoimmunity and in risk assessment with regards to pregnancy morbidity and thrombotic manifestations.

A crucial role of SUMOylation in modulating Sirt6 deacetylation of H3 at lysine 56 and its tumor suppressive activity

Sirt6 is a histone deacetylase with NAD(+)-dependent activity. Sirt6 has been shown as a tumor suppressor partially via inhibiting the expression of c-Myc target genes and ribosome biogenesis. However, how to regulate Sirt6 activity is largely unknown. In this study, we identify that Sirt6 can be modified by small ubiquitin-like modifier. Sirt6 SUMOylation deficiency specifically decreases its deacetylation of H3K56 but not H3K9 in vivo. Mechanistically, we find that SUMOylation deficiency decreases Sirt6 binding with c-Myc, decreasing Sirt6 occupancy on the locus of c-Myc target genes. Therefore, Sirt6 SUMOylation deficiency reduces its deacetylation of H3k56 and its repression of c-Myc target genes. Moreover, Sirt6 SUMOylation deficiency reduces its suppression of cell proliferation and tumorigenesis. Thus, these results reveal that SUMOylation has an important role in regulation of Sirt6 deacetylation on H3K56, as well as its tumor suppressive activity.

Effect of neural stem cell transplantation combined with erythropoietin injection on axon regeneration in adult rats with transected spinal cord injury

We investigated the effect of neural stem cells (NSC) and erythropoietin (EPO) on axon regeneration in adult rats with transected spinal cord injury, and provided an experimental basis for clinical treatment. Forty Wistar rats with T10-transected spinal cord injury were randomly divided into four groups of ten rats: a control group (group A), an NSC-transplant group (group B), an NSC-transplant and EPO group (group C), and an EPO group (group D). Biotinylated dextran amines (BDA) anterograde corticospinal cord neuronal tracing and Fluoro-Gold (FG) retrograde tracing were carried out at the 8th week after operation to observe the regeneration of nerve fibers. The Basso, Beattie, and Bresnahan (BBB) locomotor score was used to evaluate restoration. 1) BDA and FG immunofluorescence staining: in group C, a large number of regenerated axons were observed and some penetrated the injured area. In group B, only a small number of regenerated axons were observed and none penetrated the injured area. In group D, only sporadic regenerated nerve fibers were observed occasionally, while in group A, no axonal regeneration was observed. In group C, a small number of cones and axons emitted yellow fluorescence, and no FG-labeled cells were observed in the other groups. 2) The BBB scores for group C were higher than those for the other groups, and the differences were statistically significance (P < 0.05). NSC transplantation combined with EPO intraperitoneal injection may benefit axon regeneration in rats with transected spinal cord injury, and accelerate the functional recovery of the hindlimb locomotor.

Inhibition of Drp1 by Mdivi-1 attenuates cerebral ischemic injury via inhibition of the mitochondria-dependent apoptotic pathway after cardiac arrest

Mitochondrial fission is predominantly controlled by the activity of dynamin-related protein1 (Drp1), which has been reported to be involved in mitochondria apoptosis pathways. However, the role of Drp1 in a rat model of cardiac arrest remains unknown. In this study, we found that activation of Drp1 in the mitochondria was increased after cardiac arrest and inhibition of Drp1 by 1.2 mg/kg of mitochondrial division inhibitor-1 (Mdivi-1) administration after the restoration of spontaneous circulation (ROSC) significantly protected against cerebral ischemic injury, shown by the increased 72-h survival rate and improved neurological function. Moreover, the increase of the vital neuron and the reduction of cytochrome c (CytC) release, apoptosis-inducing factor (AIF) translocation and caspase-3 activation in the brain indicate that this protection might result from the suppression of neuron apoptosis. Altogether, these results indicated that Drp1 is activated after cardiac arrest and the inhibition of Drp1 is protective against cerebral ischemic injury in a rat of cardiac arrest model via inhibition of the mitochondrial apoptosis pathway.

First-line erlotinib versus gemcitabine/cisplatin in patients with advanced EGFR mutation-positive non-small-cell lung cancer: analyses from the phase III, randomized, open-label, ENSURE study

BACKGROUND

The phase III, randomized, open-label ENSURE study (NCT01342965) evaluated first-line erlotinib versus gemcitabine/cisplatin (GP) in patients from China, Malaysia and the Philippines with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients ≥18 years old with histologically/cytologically confirmed stage IIIB/IV EGFR mutation-positive NSCLC and Eastern Cooperative Oncology Group performance status 0-2 were randomized 1:1 to receive erlotinib (oral; 150 mg once daily until progression/unacceptable toxicity) or GP [G 1250 mg/m(2) i.v. days 1 and 8 (3-weekly cycle); P 75 mg/m(2) i.v. day 1, (3-weekly cycle) for up to four cycles]. Primary end point: investigator-assessed progression-free survival (PFS). Other end points include objective response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 217 patients were randomized: 110 to erlotinib and 107 to GP. Investigator-assessed median PFS was 11.0 months versus 5.5 months, erlotinib versus GP, respectively [hazard ratio (HR), 0.34, 95% confidence interval (CI) 0.22-0.51; log-rank P < 0.0001]. Independent Review Committee-assessed median PFS was consistent (HR, 0.42). Median OS was 26.3 versus 25.5 months, erlotinib versus GP, respectively (HR, 0.91, 95% CI 0.63-1.31; log-rank P = .607). ORR was 62.7% for erlotinib and 33.6% for GP. Treatment-related serious adverse events (AEs) occurred in 2.7% versus 10.6% of erlotinib and GP patients, respectively. The most common grade ≥3 AEs were rash (6.4%) with erlotinib, and neutropenia (25.0%), leukopenia (14.4%), and anemia (12.5%) with GP.

CONCLUSION

These analyses demonstrate that first-line erlotinib provides a statistically significant improvement in PFS versus GP in Asian patients with EGFR mutation-positive NSCLC (NCT01342965).

Xylaria hypoxylon Lectin as Adjuvant Elicited Tfh Cell Responses

Foot-and-mouth disease (FMD) caused by FMD virus (FMDV) is a major health and economic problem in the farming industry. Vaccination of livestock against this highly infectious viral disease is crucial, and inactivated FMD vaccine has been effective at controlling infection. However, accumulated data show that the inactivated vaccine generates weak immune responses and that the oil formulation results in undesirable side effects. Mushroom lectins have recently been shown to display adjuvant effects when incorporated into DNA vaccines. In this study, to enhance the cellular immune response of FMDV antigen (146S), C57BL/6 mice were immunized with 146S combined with Xylaria hypoxylon lectin (XHL). The oil formulation (146S/Oil) was served as control group. Strong humoral immune responses were elicited in mice immunized with 146S/XHL as shown by high 146S antigen-specific IgG levels, and also in 146S/Oil group. Interestingly, XHL in conjunction with inactivated FMD vaccine activated strong Th1 and Tc1 cell responses, especially Tfh cell responses, in immunized mice. XHL stimulated dendritic cell maturation by upregulating expression of major histocompatibility complex II (MHCII) molecules and co-stimulatory molecules CD40 and CD86 in immunized mice. No XHL-specific IgG or inflammatory factors were detected indicating the safety of XHL as an adjuvant. Taken together, these results suggest the effectiveness of XHL at inducing cellular immune responses and therefore confirm its suitability as an adjuvant for inactivated FMD vaccine.

TBX6 null variants and a common hypomorphic allele in congenital scoliosis

BACKGROUND

Congenital scoliosis is a common type of vertebral malformation. Genetic susceptibility has been implicated in congenital scoliosis.

METHODS

We evaluated 161 Han Chinese persons with sporadic congenital scoliosis, 166 Han Chinese controls, and 2 pedigrees, family members of which had a 16p11.2 deletion, using comparative genomic hybridization, quantitative polymerase-chain-reaction analysis, and DNA sequencing. We carried out tests of replication using an additional series of 76 Han Chinese persons with congenital scoliosis and a multicenter series of 42 persons with 16p11.2 deletions.

RESULTS

We identified a total of 17 heterozygous TBX6 null mutations in the 161 persons with sporadic congenital scoliosis (11%); we did not observe any null mutations in TBX6 in 166 controls (P<3.8×10(-6)). These null alleles include copy-number variants (12 instances of a 16p11.2 deletion affecting TBX6) and single-nucleotide variants (1 nonsense and 4 frame-shift mutations). However, the discordant intrafamilial phenotypes of 16p11.2 deletion carriers suggest that heterozygous TBX6 null mutation is insufficient to cause congenital scoliosis. We went on to identify a common TBX6 haplotype as the second risk allele in all 17 carriers of TBX6 null mutations (P<1.1×10(-6)). Replication studies involving additional persons with congenital scoliosis who carried a deletion affecting TBX6 confirmed this compound inheritance model. In vitro functional assays suggested that the risk haplotype is a hypomorphic allele. Hemivertebrae are characteristic of TBX6-associated congenital scoliosis.

CONCLUSIONS

Compound inheritance of a rare null mutation and a hypomorphic allele of TBX6 accounted for up to 11% of congenital scoliosis cases in the series that we analyzed. (Funded by the National Basic Research Program of China and others.).

The Porous Structure and Mechanical Properties of Injection Molded HA/PA66 Scaffolds

Hydroxyapatite/polyamide-66 (HA/PA66) composite scaffolds were prepared using injection-molding technique, and also analyzed by means of scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), Fourier transform infrared spectroscopy (FTIR) and mechanical testing. Compared with common methods including solvent casting/particulate leaching, phase separation and so forth to fabricate scaffolds, this process is of a rapid and convenient manner. The increase of HA content can increase the stiffness of composite scaffolds accompanied by the reduction of impact strength, pore size and porosity. The storage modulus of composite scaffolds increases with increasing HA content and with decreasing porosity. The damping (tan δ) of PA66 decreases with the increase of HA content, and the α and β relaxation peaks of PA66 for the foamed HA/PA66 composites slightly shift to lower value, indicating that both HA and gas in the foamed HA/PA66 composites have an effect on the chain mobility of the polymer and the interaction between the polymer chains. The microstructure of the 30 wt% and 40 wt% HA/PA66 composite scaffolds with porosity more than 59 % and pore size ranging from 100 to 500 μm is similar to that of dry human trabecular bone. The obtained composite scaffolds with 30 wt% and 40 wt% HA have a compressive modulus of 232 to 443 MPa, and a compressive strength of 9.3 to 9.8 MPa, similar to or a little higher than those of trabecular bone, and close to those of the cancellous bone.

Glucocorticoid induced autophagy in N1511 chondrocyte cells

OBJECTIVE

To determine whether autophagy was involved in chondrocyte cells post Glucocorticoids (GCs) treatment.

MATERIALS AND METHODS

LC3-GFP reporter plasmid transfection and western blotting analysis were conducted to determine the autophagic vesicles and autophagy-associated molecules in the N1511 chondrocyte cells post dexamethasone (Dex) treatment. And the N1511 cell viability was also determined by MTT assay.

RESULTS

We found that autophagy was induced in the N1511 chondrocyte cells post treatment with Dex of 5 µM to 1 mM, and the autophagy-induction by Dex could be inhibited by 3 MA and RU486, a GC antagonist. And the autophagy induced by the high dose of Dex (200 µM or 1 mM) was associated with a reduction of N1511 cell viability.

CONCLUSIONS

These results suggested that GCs could induce autophagy, as might contribute to the viability reduction of chondrocyte cells.