Doxorubicin Loaded Dextran-coated Superparamagnetic Iron Oxide Nanoparticles with Sustained Release Property: Intracellular Uptake, Pharmacokinetics, and Biodistribution Study

BACKGROUND

Due to the short biological half-life and serious side effects (especially for heart and kidney), the application of Doxorubicin (Dox) in clinical therapy is strictly limited. To overcome these shortcomings, a novel sustained release formulation of doxorubicin-loaded dextran-coated superparamagnetic iron oxide nanoparticles (Dox-DSPIONs) was prepared.

OBJECTIVE

The purpose of this study was to evaluate the intracellular uptake behavior of Dox-DSPIONs and to investigate their pharmacokinetics and biodistribution properties.

METHOD

Confocal laser scanning microscopy was employed to study the intracellular uptake and release properties of Dox from Dox-DSPIONs in SMMC-7721 cells. Simple high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method was established to study the pharmacokinetics and biodistribution properties of Dox-DSPIONs in vivo after intravenous administration and compared with free Dox.

RESULTS

Intracellular uptake experiment indicated that Dox could be released sustainedly from Dox-DSPIONs over time. The pharmacokinetics parameters displayed that the T1/2and AUC0-24h of Dox-DSPIONs were higher than those of free Dox, while the Cmax of Dox-DSPIONs was significantly lower than that of free drug. The biodistribution behaviors of the drug were altered by Dox-DSPIONs in mice, which showed obvious liver targeting, and significantly reduced the distribution of the drug in the heart and kidney.

CONCLUSION

Dox-DSPIONs have the sustained-release property in vitro and in vivo, which could significantly prolong blood circulation time, improve bioavailability, and reduce the side effects of Dox. Therefore, the novel formulation of the Dox-DSPIONs has the potential as a promising drug delivery system in cancer therapy.

[Clinical and imaging characteristics of patients with primary cardiac angiosarcoma]

Objective: To investigate the clinical, cardiac imaging characteristics and prognosis of patients with primary cardiac angiosarcoma. Methods: The clinical data of 14 patients hospitalized with primary cardiac angiosarcoma from January 2001 to December 2017 in Peking Union Medical College Hospital were collected and analyzed. Metastatic cardiac angiosarcoma was not included in this study. Patients were followed up post discharge per telephone call or clinical visit. Results: Of the 14 patients, 8 were males and 6 were females, average age was 48 years. The main clinical symptoms were shortness of breath (8/14), hemoptysis (6/14), fever (5/14), chest pain (4/14) and cough (3/14). Imaging examinations showed that the tumors of 8 patients were located in the right heart and 6 in the pericardial cavity. Tumors in the right heart often infiltrate the atrial wall and cause pericardial effusion (7/8). Tumors in the pericardium were characterized by recurrent bloody pericardial effusion (6/6), prone to progressive constrictive pericarditis (3/6), pericardial fluid cytology was often negative (6/6). MRI showed heterogeneous high signal intensity (cauliflower aspect) on T2-weighted image and heterogeneous enhancement with a"sunray" aspect at the perfusion study. At the time of diagnosis, 8 patients developed lung or adrenal metastasis (8/14). The median survival was only 305 days. Conclusions: Primary cardiac angiosarcoma is a rare disease with non-specific clinical manifestation and poor prognosis. Imaging examinations may help diagnosis. The high invasiveness and the easy-to-metastasis feature of the tumor contribute to the poor prognosis of cardiac angiosarcoma.

Human Microglia Extensively Reconstitute in Humanized-BLT Mice With Human Interleukin-34 Transgene and Support HIV-1 Brain Infection

Humanized bone marrow-liver-thymic (hu-BLT) mice develop a functional immune system in periphery, nevertheless, have a limited reconstitution of human myeloid cells, especially microglia, in CNS. Further, whether bone marrow derived hematopoietic stem and progenitor cells (HSPCs) can enter the brain and differentiate into microglia in adults remains controversial. To close these gaps, in this study we unambiguously demonstrated that human microglia in CNS were extensively reconstituted in adult NOG mice with human interleukin-34 transgene (hIL34 Tg) from circulating CD34+ HSPCs, nonetheless not in hu-BLT NOG mice, providing strong evidence that human CD34+ HSPCs can enter adult brain and differentiate into microglia in CNS in the presence of hIL34. Further, the human microglia in the CNS of hu-BLT-hIL34 NOG mice robustly supported HIV-1 infection reenforcing the notion that microglia are the most important target cells of HIV-1 in CNS and demonstrating its great potential as an in vivo model for studying HIV-1 pathogenesis and evaluating curative therapeutics in both periphery and CNS compartments.

Approximate back-projection method for improving lateral resolution in circular-scanning-based photoacoustic tomography

PURPOSE

In circular-scanning-based photoacoustic tomography (PAT), the effect of finite transducer aperture has not been effectively resolved. The goal of this paper is to propose a practical reconstruction method that accounts for the finite transducer aperture to improve the lateral resolution.

METHODS

We for the first time propose to calculate the spatial-temporal response (STR) of the employed finite-sized transducer in a forward model, and then compensate the time delay and the directional sensitivity of the transducer in the framework of the back-projection method. Both simulation and phantom experiments were carried out to evaluate the lateral resolution improvement with the proposed method. The performance of this new method for imaging complicated targets was also assessed by calculating the mean image gradient.

RESULTS

Simulation results showed that with this new method the lateral resolution for off-center targets can be as good as that for the center targets. Phantom experimental results showed that this new method can improve the lateral resolution more than two times for a point target about 5 mm far from the rotation center. Phantom experimental results also showed that many blurred fine structures of a piece of leaf veins at the off-center regions were well restored with the new method, and the mean image gradient improved about 1.3 times.

CONCLUSION

The proposed new method can effectively account for the effect of finite transducer aperture for circular-scanning-based PAT in homogenous acoustic media. This new method also features its robustness and computational efficiency, so that it is a worthy replacement to the conventional back-projection algorithm in circular-scanning-based PAT. This new method can be of great importance to the design of circular-scanning or spherical-scanning-based PAT systems.

A rare cutis verticis gyrata secondary to cerebriform intradermal nevus: case report and literature review

BACKGROUND

Cutis verticis gyrate (CVG) is a rare morphologic syndrome that presents with hypertrophy and folding of the scalp. CVG can be classified into three forms: primary essential, primary non-essential, and secondary. Cerebriform intradermal nevus (CIN) is a rare cause of secondary CVG. We are here to report a rare case of CVG with an underlying CIN and discuss the clinical course, treatment options, and critical screening guidelines for these patients.

CASE PRESENTATION

A 25 year-old male patient presented with a chief complaint of generalized hair loss in the scalp parietaloccipital region for a duration of 1 year and the hair loss area was occasionally accompanied by mild itching. The hair loss started gradually and worsened over time. In addition, he had scalp skin folds resembling the ridge and furrow of the cerebral cortex in the parietaloccipital region since birth. Physical examination revealed hypertrophy and formation of folds in the parietal-occipital area, forming 5 to 6 furrows and ridges. The size of the cerebriform mass was about 12.0 cm × 8.5 cm, without other skin lesions. Diffuse non-scarring hair loss was distributed on the posterior-parietal scalp, mid-parietal scalp and superior-occipital scalp. The diseased tissue of the patient's parietaloccipital area was excised under general anesthesia. The postoperative pathological examination of the tissue excised showed that there were dense intradermal melanocytic nevus, so the patient was diagnosed with secondary CVG caused by CIN. At the 2 year follow-up, there were no obvious changes in the lesions.

CONCLUSIONS

CIN must be differentiated from other conditions that manifest as CVG, including primary essential or non-essential CVG and secondary CVG caused by other reasons. Each CIN patient requires a specific decision of whether to excise the lesion surgically or follow a wait-and-see policy, depending on the patient's will and specific condition. Surgical treatment may be performed when there is an aesthetic demand. However, clinical observation and close follow-up is also a good treatment choice for patients with stable disease or mild symptoms.

In-vivo imaging of melanoma with simultaneous dual-wavelength acoustic-resolution-based photoacoustic/ultrasound microscopy

Melanoma is a common, highly fatal skin cancer. Photoacoustic imaging can achieve highly sensitive and high-contrast detection of melanin molecules in tissues, also inheriting the high penetration depth and high spatial resolution characteristics of ultrasound imaging, thus it is a very promising non-invasive diagnostic tool for early melanoma. In this work, we built an acoustic-resolution-based photoacoustic microscopy system, using 1064 nm/532 nm pulsed light to observe melanoma in the back of a mouse with simultaneous photoacoustic/ultrasound imaging. Through the fusion of multi-modal images, accurate positioning of melanoma and its surrounding normal tissues were realized. This work will further promote the application of photoacoustic imaging in the clinical diagnosis of early melanoma.

A Prognostic Risk Stratification Model to Identify Potential Population Benefiting From Postmastectomy Radiotherapy in T1-2 Breast Cancer With 1-3 Positive Axillary Lymph Nodes

Background and Objectives

To establish a prognostic stratification nomogram for T1–2 breast cancer with 1–3 positive lymph nodes to determine which patients can benefit from postmastectomy radiotherapy (PMRT).

Methods

A population-based study was conducted utilizing data collected from the Surveillance, Epidemiology, and End Results database. Chi-square test or Fisher exact test was used to compare the distribution of characteristics. Cox analysis identified significant prognostic factors for survival. A prognostic stratification model was constructed by R software. Propensity score matching was applied to balance characteristics between PMRT cohort and control cohort. Kaplan-Meier method was performed to evaluate the performance of stratification and the benefits of PMRT in the total population and three risk groups.

Results

The overall performance of the nomogram was good (3-year, 5-year, 10-year AUC were 0.75, 0.72 and 0.67, respectively). The nomogram was performed to excellently distinguish low-risk, moderate-risk, and high-risk groups with 10-year overall survival (OS) of 86.9%, 73.7%, and 62.7%, respectively (P<0.001). In the high-risk group, PMRT can significantly better OS with 10-year all-cause mortality reduced by 6.7% (P = 0.027). However, there was no significant survival difference between PMRT cohort and control cohort in low-risk (P=0.49) and moderate-risk groups (P = 0.35).

Conclusion

The current study developed the first prognostic stratification nomogram for T1–2 breast cancer with 1–3 positive axillary lymph nodes and found that patients in the high-risk group may be easier to benefit from PMRT.

Biochar Improves Soil-Tomato Plant, Tomato Production, and Economic Benefits under Reduced Nitrogen Application in Northwestern China

The tomato is an important economic crop that is a main ingredient of some prepared food as well as a focus of the agricultural industry. Optimizing nitrogen (N) fertilizers is essential for sustainable agricultural development, while the excessive use of N fertilizers leads to environmental and food production problems. As a soil amendment, biochar has been widely used to improve soil quality and crop yield. However, little information is available on the effects of biochar and N fertilizer reduction on tomato plant, soil characteristics in tomato cultivation and tomato production. In this study, a greenhouse experiment was carried out in Yangling, Shaanxi province, China, including four biochar levels (0, 30, 50, and 70 t ha⁻¹) under drip irrigation and four N application rates (170, 190, 210, and 250 kg ha⁻¹). The results showed that adding too much biochar (e.g., 70 t ha⁻¹) and reducing N fertilizer too far (e.g., by 32%) will not lead to satisfactory results in terms of tomato growth, tomato yield and quality, and economic benefits. Biochar addition could significantly enhance microbial abundance, enzyme activity, and tomato growth compared with non‒biochar treatments when reducing the amount of applied N fertilizer by 16% or 24% (N2 and N3). From the perspectives of tomato yield, tomato quality (sugar‒acid ratio and vitamin C (VC) content), and economic benefits, optimal application rate of biochar and N fertilizer based on the silty clay loam soil of northwest China under drip irrigation is proposed, respectively. The proposal is based on both multidimensional nonlinear regression models and a comparison with experimental treatments. For example, biochar addition at 50 t ha⁻¹ and reducing N fertilizer by 24% achieved the greatest tomato yield. Compared with non-biochar treatment under the corresponding N fertilizer level, soil enzyme activity (urease, phosphatase, and catalase), microbial abundance (bacteria, fungi, and actinomycetes), leaf gas exchange parameters (gs, Pn, and Tr), and biomass increased on average by 88.76%, 7.49%, 43.23%, and 39.67%, respectively. Based on a comprehensive consideration of tomato yield, VC content, sugar‒acid ratio, and economic benefits, 35 t ha⁻¹ biochar and 200 kg ha⁻¹ N fertilizer is the recommended combination of biochar and nitrogen fertilizer for local farmers.

Multi-Way Analysis Coupled with Near-Infrared Spectroscopy in Food Industry: Models and Applications

Near-infrared spectroscopy (NIRS) is a fast and powerful analytical tool in the food industry. As an advanced chemometrics tool, multi-way analysis shows great potential for solving a wide range of food problems and analyzing complex spectroscopic data. This paper describes the representative multi-way models which were used for analyzing NIRS data, as well as the advances, advantages and limitations of different multi-way models. The applications of multi-way analysis in NIRS for the food industry in terms of food process control, quality evaluation and fraud, identification and classification, prediction and quantification, and image analysis are also reviewed. It is evident from this report that multi-way analysis is presently an attractive tool for modeling complex NIRS data in the food industry while its full potential is far from reached. The combination of multi-way analysis with NIRS will be a promising practice for turning food data information into operational knowledge, conducting reliable food analyses and improving our understanding about food systems and food processes. To the best of our knowledge, this is the first paper that systematically reports the advances on models and applications of multi-way analysis in NIRS for the food industry.

MiRNA-202-5p promotes Colorectal Carcinogenesis through suppression of PTEN

Colorectal cancer (CRC) is still one of the leading causes of cancer-associated death in the modern society. The biological function of miR-202-5p for CRC development remains controversial, largely due to the fact that miR-202-5p can be tumor-suppressive or oncogenic in different contexts. Obtained results indicated that aberrant expression of miR-202-5p was observed in majority of human CRC samples and miR-202-5p was transcriptionally up-regulated by c-Myc. In addition, miR-202-5p functions to promote the activation of PI3K/Akt signaling pathway by directly suppressing PTEN. Silencing or enforced expression of miR-202-5p resulted in CRC cell proliferation inhibition and enhancement, respectively. Importantly, decreased PTEN level and increased phosphorylation of Akt were frequently associated with elevated miR-202-5p expression in colorectal cancer tissues. Increased miR-202-5p expression may serve as a tumor promoter by directly targeting PTEN in colorectal cancer.

Detection of EGFR Mutations in Cerebrospinal Fluid of EGFR-Mutant Lung Adenocarcinoma With Brain Metastases

Background

We aimed to investigate the feasibility of detecting epidermal growth factor receptor (EGFR) mutations in cell-free DNA (cfDNA) from cerebrospinal fluid (CSF) and plasma of advanced lung adenocarcinoma (LADC) with brain metastases (BMs) by droplet digital polymerase chain reaction (ddPCR).

Methods

Thirty advanced LADC patients with BMs were enrolled, and their matched CSF and plasma samples were collected. Droplet digital PCR was used to test cfDNA in CSF and plasma for EGFR mutation status. The clinical response and prognosis were evaluated.

Results

Out of 30 patients, there were 21 females and 9 males, aged 34-75 years. In all of the cases, CSF cytology were negative. In ddPCR assays, 10 patients (33.3%) had EGFR mutation in CSF, including 3 cases of EGFR T790M mutation, and 16 patients (53.3%) had EGFR mutation in plasma, including 6 cases of EGFR T790M mutation. Five patients with activating EGFR mutations in CSF achieved an intracranial partial response (iPR) after combination treatment with the first-generation EGFR-tyrosine kinase inhibitors. Three patients with EGFR T790M mutations in CSF achieved iPR after second-line osimertinib treatment. The median overall survival and intracranial progression-free survival were 17.0 months and 11.0 months, respectively.

Conclusion

It was feasible to test EGFR mutation in cerebrospinal fluid and plasma. In LADC patients with brain metastasis, cerebrospinal fluid can be used as a liquid biopsy specimen to guide treatment strategy by monitoring EGFR mutation status.

Discovery of a Novel Series of Pyridone-Based EP3 Antagonists for the Treatment of Type 2 Diabetes

A novel series of pyridones were discovered as potent EP3 antagonists. Optimization guided by EP3 binding and functional assays as well as by eADME and PK profiling led to multiple compounds with good physical properties, excellent oral bioavailability, and a clean in vitro safety profile. Compound 13 was identified as a lead compound as evidenced by the reversal of sulprostone-induced suppression of glucose-stimulated insulin secretion in INS 1E β-cells in vitro and in a rat ivGTT model in vivo. A glutathione adduction liability was eliminated by replacing the naphthalene of structure 13 with the indazole ring of structure 43.

[Probability of premature mortality caused by four major non-communicable diseases and its impact on life expectancy in Wuxi, 2008-2018]

Objective: To analyze the trend of premature death of non-communicable diseases (NCDs) in Wuxi from 2008 to 2018 and evaluate the influence of premature mortality probability caused by four main NCDs on life expectancy. Methods: Based on the mortality data collected by Wuxi Mortality Registration System and the population data collected by Wuxi Public Security Bureau during 2008-2018, this study analyzes the trend of the probability of premature death on malignant tumors, cardiovascular and cerebrovascular diseases, chronic respiratory diseases, and diabetes. The impact on life expectancy was analyzed by using the methods of abridged life table, Joinpoint regression, and life expectancy contribution decomposition. Results: From 2008 to 2018, the total probability of premature death of four main NCDs in Wuxi were declined consistently from 11.25% to 9.25% (AAPC = -2.0%, 95%CI: -2.6--1.5), higher in female (from 7.74% to 5.91%) than that in male (from 14.49% to 12.51%). The Wuxi resident's life expectancy increased by 1.86 years (from 78.66 to 80.52 years), in males and 1.26 years (from 83.85 to 85.11 years) in females, respectively. The decline of premature death of malignant tumors, cardiovascular and cerebrovascular diseases and chronic respiratory system diseases had a positive contribution to life expectancy, which contributed 0.34 years (23.90%), 0.15 years (10.50%), and 0.03 years (2.36%) to the life expectancy growth, respectively. Among which, premature death of cardiovascular and cerebrovascular diseases in men aged 40-55y had a negative contribution to life expectancy (-0.04 years). The probability of premature death of males with diabetes was on the rise (AAPC = 7.1%, 95%CI: 2.8-11.6), which negatively contributed to life expectancy for both males and females, reducing life expectancy by 0.03 years (-2.14%) in Wuxi. Conclusion: The premature death probability of four main NCDs in Wuxi declined consistently from 2008 to 2018, which played a positive role in the growth of life expectancy. Compared with females, males had a higher premature death probability and a slower rate of decline. More intervention and health management of premature male death on cardiovascular and cerebrovascular diseases and diabetes should be conducted to improve life expectancy further.

Biodegradable JDBM coating stent has potential to be used in the treatment of benign biliary strictures

In our previous study, to find out the optimal alloy suitable for biliary surgery, magnesium alloy Jiao Da Bio-magnesium (denoted as JDBM) alloy, Zn-3Cu alloys, and their respective coating (MgF₂-PDLLA) products were produced for our research. We found that JDBM seems to be a potential material for clinical biliary stent application due to its uniform degradation and good compatibility. In order to apply the JDBM alloy to treat benign bile duct stricture, our group prepared the bare JDBM and its coating product into finished stents by mesh weaving carving technology and conducted the mechanical property tests, degradation tests and biocompatibility tests. During the mechanical property tests, we found the bare JDBM stent was more suitable than titanium alloy stent when applies to the bile duct, and the coating of the JDBM coating stent has no effect on its mechanical properties. Our in vitro and in vivo experiments revealed that the degradation rate of the JDBM coating stent is lower than that of the JDBM stent, and both stents were biosafe. Thus, there is promise for JDBM coating stents for the treatment of benign biliary strictures.

Induced neural stem cell grafts exert neuroprotection through an interaction between Crry and Akt in a mouse model of closed head injury

Background

Recently, growing evidence has indicated an important role of the complement system, a crucial component of immunity, in mediating neuroinflammation and promoting neuronal apoptosis following closed head injury (CHI). We previously reported that transplanted induced neural stem cells (iNSCs) pre-treated with CHI mouse serum could enhance complement receptor type 1-related protein y (Crry) expression and ameliorate complement-mediated damage in mouse CHI models. However, the mechanism underlying the elevated levels of Crry expression remains elusive.

Methods

CHI models were established using a standardized weight-drop device. We collected CHI mouse serum at 12 h post-trauma. RT-QPCR assay, western blot analysis, complement deposition assay, Akt inhibition assay, flow cytometry, cell transplantation, and functional assay were utilized to clarify the mechanism of Crry expression in iNSCs receiving CHI mouse serum treatment.

Results

We observed dramatic increases in the levels of Crry expression and Akt activation in iNSCs receiving CHI mouse serum treatment. Remarkably, Akt inhibition led to the reduction of Crry expression in iNSCs. Intriguingly, the treatment of iNSC-derived neurons with recombinant complement receptor 2-conjugated Crry (CR2-Crry), which inhibits all complement pathways, substantially enhanced Crry expression and Akt activation in neurons after CHI mouse serum treatment. In subsequent in vitro experiments of pre-treatment of iNSCs with CR2-Crry, we observed significant increases in the levels of Crry expression and Akt activation in iNSCs and iNSC-derived astrocytes and neurons post-treatment with CHI mouse serum. Additionally, an in vivo study showed that intracerebral-transplanted iNSCs pre-treated with CR2-Crry markedly enhanced Crry expression in neurons and protected neurons from complement-dependent damage in the brains of CHI mice.

Conclusion

INSCs receiving CR2-Crry pre-treatment increased the levels of Crry expression in iNSCs and iNSC-derived astrocytes and neurons and attenuated complement-mediated injury following CHI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02186-z.

Mapping abandoned farmland in China using time series MODIS NDVI

Farmland abandonment is an important aspect of land cover land use (LCLU) that has both positive and negative effects on the environment. There is limited information regarding the spatial distribution of abandoned farmland in China. In this study, we 1) use a C5.0 decision tree classification based on a 250 m spatial resolution Moderate-resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) time series to develop LCLU maps for the period 2000-2017; 2) produce time series maps of the abandoned farmland during the period 2002-2017 based on LCLU maps; and 3) analyze spatial distribution, intensity, trend, frequency, and recultivation in terms of farmland abandonment. The results show that the overall accuracy of the LCLU maps ranged from 85.45% to 90.56% over the study period (2002-2017). The average national rate of farmland abandonment was 5% over the period 2002-2017, with the lowest rate in 2002 and the highest in 2015. Approximately 60% of the 34 agricultural areas in China showed an increasing trend for abandonment including some of the main grain-producing areas such as the North China Plain and the middle and lower reaches of the Yangtze River. Abandoned farmland areas with an abandonment frequency of ≤ 3 y comprised 58.24% of the total area of abandoned farmland. The first map detailing the distribution of the abandoned farmland across China was produced in this study, providing guidance for the development of a method of identifying abandoned farmland on a large spatial scale.

[Preliminary study on the protective effect of glycosyltransferase Colgalt2 gene deletion on acetaminophen-induced liver injury]

Objective: To investigate the protective effect of Colgalt2 gene deletion on acute liver injury induced by acetaminophen (APAP) in mice. Methods: Colgalt2(+/+) wild-type control mice and Colgalt2(-/-) mice (all C57BL/6J strains) were selected as the research subject. APAP solution was injected intraperitoneally to establish a mouse model of acute liver injury. The mouse were divided into four groups: Colgalt2(+/+) wild-type control group, Colgalt2(+/+) wild-type drug group (APAP 500 mg/kg), Colgalt2(-/-) control group, and Colgalt2(-/-) drug group (APAP 500 mg/kg). The survival rate was measured to plot survival curve. Liver function was evaluated by detecting serum ALT and AST levels. Liver histopathological changes were observed by HE staining to evaluate the condition of liver injury. Western blot was used to detect protein c-Jun N-terminal kinase (JNK)-related liver injury. Results: Compared with Colgalt2(+/+) mice, the survival rate was significantly increased after giving APAP to Colgalt2(-/-) mice (86.7% vs. 40%), and liver cell necrosis and inflammatory cell infiltrates of Colgalt2(+/+) mice were milder. Serum ALT, and AST level was significantly decreased [ALT: (5 291.9 ± 1 016.34) U/L vs. (1 616.9 ± 330.65) U/L, P = 0.000; AST: (4 978.0 ± 1 028.43) U/L vs. (1 851.0 ± 437.55) U/L, P = 0.000]. The expression level of JNK was significantly decreased in liver tissue. Conclusion: Colgalt2 gene deletion has a protective effect on acute liver injury induced by acetaminophen (APAP) in mice. Therefore, Colgalt2 may be a potential therapeutic option for acetaminophen-induced hepatotoxicity.

3D acoustic resolution-based photoacoustic endoscopy with dynamic focusing

Background

Acoustic resolution-based photoacoustic endoscopy (ARPAE) is a non-invasive potential tool for imaging gastrointestinal and urogenital tracts. However, current ARPAE systems usually only provide 2D sectorial B-mode images, and have the limitation of the image quality significantly deteriorating out-of-focus regions due to transducers with fixed focus in these systems. To overcome these limitations, we put forward a modified back-projection method that can provide 3D images with dynamic focusing in ARPAE.

Methods

A graphics processing unit (GPU)-based parallel computation technique was adopted for efficient computation. Both simulated and phantom/ex-vivo experiments were conducted to validate our method.

Results

The findings indicated that our proposed method can effectively improve the lateral resolution and signal-to-noise ratio (SNR) in the out-of-focus regions. For a target 3 mm from the transducer focus, the new method can improve 11 times in the lateral resolution, along with an improvement of up to 37 dB in the SNR.

Conclusions

3D ARPAE provides high-quality imaging in both focus and out-of-focus regions.

[Folic acid supplementation before and during pregnancy and the risk of preeclampsia]

Objective: To investigate the relationship between folic acid supplementation and the risk of preeclampsia (PE). Methods: A total of 9 048 pregnant women were selected from the First Hospital of Shanxi Medical University in Taiyuan from March 2012 to September 2016. Among them, 882 pregnant women with PE were divided into case group, and 8 166 pregnant women without PE were divided into control group. Information on demographic characteristics, folic acid supplementation, maternal complications, and other factors were collected by face-to-face interviews after child birth in the hospital. Unconditional logistic regression analyses were used to investigate the relationship between folic acid supplementation and the risk of PE and the effects of pre-pregnancy BMI on the relationship of folic acid supplementation with the risk of PE. Results: Compared with nonusers, folic acid supplement users had reduced risk of PE (OR=0.79, 95%CI: 0.64-0.96). Folic acid supplementation before and during pregnancy were negatively related with the risk of PE (OR=0.63, 95%CI: 0.49-0.81). Pregnant women who used folic acid tablets only or used both folic acid tablets and multivitamin containing folic acid had reduced risk of PE (OR=0.81, 95%CI: 0.66-0.99; OR=0.64, 95%CI: 0.49-0.85). No significant relationship was observed in the multivitamin group. Supplemental folic acid doses of <400, 400, and >400 μg/d were related with reduced risk of PE (OR=0.62, 95%CI: 0.42-0.91; OR=0.81, 95%CI: 0.66-0.99; OR=0.68, 95%CI: 0.49-0.94). After stratified by pre-pregnancy BMI, pregnant women who used folic acid supplementation, those with pre-pregnancy BMI<24.0 kg/m(2) had reduced risk of PE (OR=0.75, 95%CI: 0.59-0.96). However, no significant relationship was observed in women with pre-pregnancy BMI≥24.0 kg/m(2). Conclusions: Folic acid supplementation before and during pregnancy were related with reduced risk of PE. Pre-pregnancy BMI might affect the relationship between folic acid supplementation and the risk of PE. Appropriate folic acid supplementation should be recommend for women with different pre-pregnancy BMI.

Environmental virus detection associated with asymptomatic SARS-CoV-2-infected individuals with positive anal swabs

In the fight against the outbreak of COVID-19 in China, we treated some asymptomatic infected individuals. This study aimed to detect pathogens in biological and environmental samples of these asymptomatic infected individuals and analyse their association. Using a cross-sectional study design, we collected biological and environmental samples from 19 patients treated in the isolation ward of Nanjing No.2 Hospital. Biological samples included saliva, pharyngeal swabs, blood, anal swabs, and exhaled breath condensate. Swab samples from the ward environment included inside masks, outside masks, palm swabs, bedside handrails, bedside tables, cell phone screens, toilet cell phone shelves, toilet pads and toilet lids. We also obtained some samples from public areas. We used RT-PCR to detect pathogens and colloidal gold to detect antibodies. As results, 19 asymptomatic infected individuals participated in the survey, with 8 positives for pathogens and 11 positives only for antibodies. Three positive samples were detected from among 96 environmental samples, respectively, from a cell phone surface, a cell phone shelf and a bedside handrail. No positive samples were detected in the exhaled breath condensate in this work. All patients identified pathogens in the environment had positive anal swabs. There was a statistical association between positive anal swabs and positive environmental samples. The association of positive samples from the surrounding of asymptomatically infected patients with positive anal swabs suggested that patients might secrete the virus for a more extended period.

Quantitative selenium speciation in feed by enzymatic probe sonication and ion chromatography-inductively coupled plasma mass spectrometry

A rapid, sensitive and species preservative analytical method for the simultaneous determination of six selenium (Se) species has been developed. Enzymatic probe sonication (EPS) was investigated as a novel and alternative technology for the extraction of Se species from feed matrices and the results were compared with the conventional hot water extraction, enzymatic hydrolysis and sequential extraction. The critical parameters of EPS such as enzyme types, extraction time, temperature, ultrasonic power and sample/enzyme ratio were varied with control. The Se species were separated and quantitatively determined by ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS). Under current optimised conditions, six inorganic and organic Se species were completely separated within 15 min in a single chromatographic run. The spectral interferences from the argon plasma ⁴⁰Ar₂, ⁴⁰Ar³⁷Cl or ¹H⁷⁹Br were effectively removed by employing the kinetic energy discrimination (KED) mode. Quantitative extraction for total Se (>94.8%) and more than 89.0% for the sum of different Se chemical forms without species transformation were obtained in only 60 s by applying the EPS treatment using aqueous protease XIV. The limits of detection (LODs) and quantification (LOQs) for Se species were in the ranges of 0.21-0.56 µg kg^-1 and 0.69-1.87 µg kg^-1, respectively. The proposed method was successfully applied to the speciation of Se in several reference materials and feed samples collected from the markets and local farms.

Upregulation of Antioxidant Capacity and Nucleotide Precursor Availability Suffices for Oncogenic Transformation

The emergence of cancer from diverse normal tissues has long been rationalized to represent a common set of fundamental processes. However, these processes are not fully defined. Here, we show that forced expression of glucose-6-phosphate dehydrogenase (G6PD) affords immortalized mouse and human cells anchorage-independent growth in vitro and tumorigenicity in animals. Mechanistically, G6PD augments the NADPH pool by stimulating NAD+ kinase-mediated NADP+ biosynthesis in addition to converting NADP+ to NADPH, bolstering antioxidant defense. G6PD also increases nucleotide precursor levels through the production of ribose and NADPH, promoting cell proliferation. Supplementation of antioxidants or nucleosides suffices to convert immortalized mouse and human cells into a tumorigenic state, and supplementation of both is required when their overlapping metabolic consequences are minimized. These results suggest that normal cells have a limited capacity for redox balance and nucleotide synthesis, and overcoming this limit might represent a key aspect of oncogenic transformation.

Comprehensive evaluation of corneas from normal, forme fruste keratoconus and clinical keratoconus patients using morphological and biomechanical properties

OBJECTIVE

To more comprehensively evaluate the ability of the parameters reflecting the morphological and biomechanical properties of the cornea to distinguish clinical keratoconus (CKC) and forme fruste keratoconus (FFKC) from normal.

METHODS

Normal eyes (n = 50), CKC (n = 45) and FFKC (n = 15) were analyzed using Pentacam, Corvis ST and ORA. Stepwise logistic regression of all parameters was performed to obtain the optimal combination model capable of distinguishing CKC, FFKC from normal, named SLR1 and SLR2, respectively. Receiver operating characteristic (ROC) curves were applied to determine the predictive accuracy of the parameters and the two combination models, as described by the area under the curve (AUC). AUCs were compared using the DeLong method.

RESULTS

The SLR1 model included only the TBI output by Pentacam, while the SLR2 model included the morphological parameter F.Ele.Th and two parameters from the Corvis ST, HC DfA and SP-A1. The majority of the parameters had sufficient strength to differentiate the CKC from normal corneas, even the seven separate parameters and the SLR1 model had a discrimination efficiency of 100%. The predictive accuracy of the parameters was moderate for FFKC, and the SLR2 model (0.965) presented an excellent AUC, followed by TBI, F.Ele.Th and BAD-D.

CONCLUSION

The F.Ele.Th from Pentacam was the most sensitive morphological parameter for FFKC, and the combination of F.Ele.Th, HC DfA and SP-A1 made the diagnosis of FFKC more efficient. The CRF and CH output by ORA did not improve the combined diagnosis, despite the corneal combination of morphological and biomechanical properties that optimized the diagnosis of FFKC.

ResGNet-C: A graph convolutional neural network for detection of COVID-19

The widely spreading COVID-19 has caused thousands of hundreds of mortalities over the world in the past few months. Early diagnosis of the virus is of great significance for both of infected patients and doctors providing treatments. Chest Computerized tomography (CT) screening is one of the most straightforward techniques to detect pneumonia which was caused by the virus and thus to make the diagnosis. To facilitate the process of diagnosing COVID-19, we therefore developed a graph convolutional neural network ResGNet-C under ResGNet framework to automatically classify lung CT images into normal and confirmed pneumonia caused by COVID-19. In ResGNet-C, two by-products named NNet-C, ResNet101-C that showed high performance on detection of COVID-19 are simultaneously generated as well. Our best model ResGNet-C achieved an averaged accuracy at 0.9662 with an averaged sensitivity at 0.9733 and an averaged specificity at 0.9591 using five cross-validations on the dataset, which is comprised of 296 CT images. To our best knowledge, this is the first attempt at integrating graph knowledge into the COVID-19 classification task. Graphs are constructed according to the Euclidean distance between features extracted by our proposed ResNet101-C and then are encoded with the features to give the prediction results of CT images. Besides the high-performance system, which surpassed all state-of-the-art methods, our proposed graph construction method is simple, transferrable yet quite helpful for improving the performance of classifiers, as can be justified by the experimental results.