A statistical approach to system suitability testing for mass spectrometry imaging

RATIONALE

Mass spectrometry imaging (MSI) elevates the power of conventional mass spectrometry (MS) to multidimensional space, elucidating both chemical composition and localization. However, the field lacks any robust quality control (QC) and/or system suitability testing (SST) protocols to monitor inconsistencies during data acquisition, both of which are integral to ensure the validity of experimental results. To satisfy this demand in the community, we propose an adaptable QC/SST approach with five analyte options amendable to various ionization MSI platforms (e.g., desorption electrospray ionization, matrix-assisted laser desorption/ionization [MALDI], MALDI-2, and infrared matrix-assisted laser desorption electrospray ionization [IR-MALDESI]).

METHODS

A novel QC mix was sprayed across glass slides to collect QC/SST regions-of-interest (ROIs). Data were collected under optimal conditions and on a compromised instrument to construct and refine the principal component analysis (PCA) model in R. Metrics, including mass measurement accuracy and spectral accuracy, were evaluated, yielding an individual suitability score for each compound. The average of these scores is utilized to inform if troubleshooting is necessary.

RESULTS

The PCA-based SST model was applied to data collected when the instrument was compromised. The resultant SST scores were used to determine a statistically significant threshold, which was defined as 0.93 for IR-MALDESI-MSI analyses. This minimizes the type-I error rate, where the QC/SST would report the platform to be in working condition when cleaning is actually necessary. Further, data scored after a partial cleaning demonstrate the importance of QC and frequent full instrument cleaning.

CONCLUSIONS

This study is the starting point for addressing an important issue and will undergo future development to improve the efficiency of the protocol. Ultimately, this work is the first of its kind and proposes this approach as a proof of concept to develop and implement universal QC/SST protocols for a variety of MSI platforms.

Metabolic Markers and Association of Biological Sex in Lupus Nephritis

Lupus nephritis (LN) is a serious complication for many patients who develop systemic lupus erythematosus, which primarily afflicts women. Our studies to identify biomarkers and the pathogenic mechanisms underlying LN will provide a better understanding of disease progression and sex bias, and lead to identification of additional potential therapeutic targets. The glycosphingolipid lactosylceramide (LacCer) and N-linked glycosylated proteins (N-glycans) were measured in urine and serum collected from LN and healthy control (HC) subjects (10 females and 10 males in each group). The sera from the LN and HC subjects were used to stimulate cytokine secretion and intracellular Ca2+ flux in female- and male-derived primary human renal mesangial cells (hRMCs). Significant differences were observed in the urine of LN patients compared to HCs. All major LacCers species were significantly elevated and differences between LN and HC were more pronounced in males. 72 individual N-glycans were altered in LN compared to HC and three N-glycans were significantly different between the sexes. In hRMCs, Ca2+ flux, but not cytokine secretion, was higher in response to LN sera compared to HC sera. Ca2+ flux, cytokine secretion, and glycosphingolipid levels were significantly higher in female-derived compared to male-derived hRMCs. Relative abundance of some LacCers and hexosylceramides were higher in female-derived compared to male-derived hRMCs. Urine LacCers and N-glycome could serve as definitive LN biomarkers and likely reflect renal disease activity. Despite higher sensitivity of female hRMCs, males may experience greater increases in LacCers, which may underscore worse disease in males. Elevated glycosphingolipid metabolism may poise renal cells to be more sensitive to external stimuli.

Aflatoxin B1-induced early developmental hepatotoxicity in larvae zebrafish

Aflatoxin B1 (AFB1) is a ubiquitous mycotoxin that causes oxidative damage in various organs. At present, the research studies on AFB1 are primarily focused on its effects on the terrestrial environment and animals. However, its toxicity mechanism in aquatic environments and aquatic animals has not been largely explored. Thus, in this study, zebrafish was used as a model to study the toxicity mechanism of AFB1 on the liver of developing larvae. The results showed that AFB1 exposure inhibited liver development and promoted fat accumulation in the liver. Transcriptome sequencing analysis showed that AFB1 affected liver redox metabolism and oxidoreductase activity. KEGG analysis showed that AFB1 inhibited the expression of gsto1, gpx4a, mgst3a, and idh1 in the glutathione metabolizing enzyme gene pathway, resulting in hepatic oxidative stress. At the same time, AFB1 also inhibited the expression of acox1, acsl1b, pparα, fabp2, and cpt1 genes in peroxidase and PPAR metabolic pathways, inducing hepatic steatosis and lipid droplet accumulation. Antioxidant N-Acetyl-l-cysteine (NAC) preconditioning up-regulated gsto1, gpx4a and idh1 genes, and improved the AFB1-induced lipid droplet accumulation in the liver. In summary, AFB1 induced hepatic oxidative stress and steatosis, resulting in abnormal liver fat metabolism and accumulation of cellular lipid droplets. NAC could be used as a potential preventative drug to improve AFB1-induced fat accumulation.

Integrated physio-biochemical and RNA sequencing analysis revealed mechanisms of long non-coding RNA-mediated response to cadmium toxicity in wheat

The yield and quality of wheat (Triticum aestivum L.) is seriously affected by soil cadmium (Cd), a hazardous material to plant and human health. Long non-coding RNAs (lncRNAs) of plants are shown actively involved in response to various biotic and abiotic stresses by mediating the gene regulatory networks. However, the functions of lncRNAs in wheat against Cd stress are still obscure. Using deep strand-specific RNA sequencing, 10,044 confident novel lncRNAs in wheat roots response to Cd stress were identified. It was found that 69 lncRNA-target pairs referred to cis-acting regulation and impacted the expressions of their neighboring genes involving in Cd transport and detoxification, photosynthesis, and antioxidant defense. These findings were positively corelated with the physio-biochemical results, i.e. Cd stress affected Cd accumulation, photosynthesis system and ROS in wheat. Overexpression of lncRNA37228 (targeted to a photosystem II protein D1 coding gene), resulted in enhancing Arabidopsis thaliana resistance against Cd stress. By genome-wide identification and characterization, the possible functions of photosystem II protein gene family in wheat under Cd condition were illustrated. Our findings provide novel knowledge into the molecular mechanisms of lncRNAs-regulated wheat tolerance to Cd toxicity and lay foundations for the further studies concerning lncRNAs in food safety production.

Efficient Spin-to-Charge Conversion via Altermagnetic Spin Splitting Effect in Antiferromagnet RuO_{2}

The relativistic spin Hall effect and inverse spin Hall effect enable the efficient generation and detection of spin current. Recently, a nonrelativistic altermagnetic spin splitting effect (ASSE) has been theoretically and experimentally reported to generate time-reversal-odd spin current with controllable spin polarization in antiferromagnet RuO_{2}. The inverse effect, electrical detection of spin current via ASSE, still remains elusive. Here we show the spin-to-charge conversion stemming from ASSE in RuO_{2} by the spin Seebeck effect measurements. Unconventionally, the spin Seebeck voltage can be detected even when the injected spin current is polarized along the directions of either the voltage channel or the thermal gradient, indicating the successful conversion of x- and z-spin polarizations into the charge current. The crystal axes-dependent conversion efficiency further demonstrates that the nontrivial spin-to-charge conversion in RuO_{2} is ascribed to ASSE, which is distinct from the magnetic or antiferromagnetic inverse spin Hall effects. Our finding not only advances the emerging research landscape of altermagnetism, but also provides a promising pathway for the spin detection.

A bottom-up proteomics workflow for a system containing multiple organisms

RATIONALE

Discovery proteomics has been popularized to be essential in the investigator's biological toolbox. Many biological problems involve the interplay of multiple organisms. Herein, a bottom-up proteomics workflow was developed to study a system containing multiple organisms to promote a thorough understanding of how each interacts with the others.

METHODS

A label-free quantification proteomics workflow was developed with nanoscale liquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). This protocol describes a bottom-up proteomics workflow used to study differential protein expression in the context of fleas (Ctenocephalides felis felis) experimentally infected by the bacterium Bartonella henselae, the etiological agent of Cat Scratch Disease (CSD).

RESULTS

Step-by-step instructions are provided for protein extraction, protein cleanup, total protein measurement, nanoLC-MS/MS data acquisition, and data analysis using Proteome Discoverer software. Comprehensive and exhaustive details are included to promote the adoption of this proteomics workflow in other laboratories.

CONCLUSION

A proteomics protocol is detailed for a system containing multiple proteomes from different taxonomic lineages using CSD (cats bitten by fleas infected with Bartonella henselae) as a model. The operating protocol can be readily applied to other label-free proteomics work involving multiple proteomes from taxonomically distinct organisms.

Transforming a Mid-infrared Laser Profile from Gaussian to a Top-Hat with a Diffractive Optical Element for Mass Spectrometry Imaging

Many mass spectrometry imaging (MSI) applications such as infrared matrix-assisted electrospray ionization (IR-MALDESI) employ an infrared (IR) laser with a Gaussian profile where laser irradiance is highest in the center and decreases exponentially. To enable full ablation of a square region of interest, oversampling is often needed, which results in nonuniform ablation and leads to decreased image quality. A diffractive optical element (DOE) was integrated into the optical path to generate homogeneous intensity distributions while maintaining laser energy above the ablation threshold, to enable complete sample removal from laser pulses without oversampling. 2D and 3D imaging with the DOE inserted show clear and sharp ablation patterns with satisfactory biological signals gained. Further improvements will optimize the beam profile and generate a square top-hat laser beam for MSI application at higher spatial resolution.

Association between CYP2E1 C-1054T and 96-bp I/D genetic variations and the risk of polycystic ovary syndrome in Chinese women

PURPOSE

To investigate the association of cytochrome P450 2E1 (CYP2E1) C-1054T (rs2031920) and 96-bp I/D genetic variations with the risk of polycystic ovary syndrome (PCOS), and to estimate the effects of genotypes on the clinical, metabolic, hormonal, and oxidative stress indicators.

METHODS

This case-control study included 762 control women and 1034 patients with PCOS. Genotypes were determined using polymerase chain reaction and/or restriction fragment length polymorphism analysis. Clinical and biochemical parameters were also analyzed.

RESULTS

Frequencies of the TT + CT genotype (35.4 vs. 28.9%) and T allele (19.6 vs. 16.0%) of the CYP2E1 C-1054T polymorphism were significantly higher in the PCOS group than in the control group (OR = 1.350, 95% CI 1.103-1.652, P = 0.004 for the dominant model). Genotype TT + CT remained a significant predictor of PCOS in a logistic regression model including age, body mass index (BMI), and recruitment year of participants (OR = 1.345, 95% CI 1.071-1.688, P = 0.011). No statistical differences were found in the genotype and allele frequencies of CYP2E1 96-bp I/D polymorphism. However, the combined genotype DD/TT + CT was related to an increased risk of PCOS when the DD/CC wild-type combined genotype was used as a reference. Patients with the I allele of 96-bp I/D polymorphism had a lower BMI but higher plasma apolipoprotein B and oxidized low-density lipoprotein cholesterol levels than those with the DD genotype.

CONCLUSION

CYP2E1 C-1054T, but not 96-bp I/D, genetic polymorphism is associated with an increased risk of PCOS in Chinese women.

Improved spatial resolution of infrared matrix-assisted laser desorption electrospray ionization mass spectrometry imaging using a reflective objective

RATIONALE

The level of visual detail of a mass spectrometry image is dependent on the spatial resolution with which it is acquired, which is largely determined by the focal diameter in infrared laser ablation-based techniques. While the use of mid-IR light for mass spectrometry imaging (MSI) has advantages, it results in a relatively large focal diameter and spatial resolution. The continual advancement of infrared matrix-assisted electrospray ionization (IR-MALDESI) for MSI warranted novel methods to decrease laser ablation areas and thus improve spatial resolution.

METHODS

In this work, a Schwarzschild-like reflective objective was incorporated into the novel NextGen IR-MALDESI source and characterized on both burn paper and mammalian tissue using an ice matrix. Ablation areas, mass spectra, and annotations obtained using the objective were compared against the current optical train on the NextGen system without modification.

RESULTS

The effective resolution was determined to be 55 μm by decreasing the step size until oversampling was observed. Use of the objective improved the spatial resolution by a factor of three as compared against the focus lens.

CONCLUSIONS

A Schwarzschild-like reflective objective was successfully incorporated into the NextGen source and characterized on mammalian tissue using an ice matrix. The corresponding improvement in spatial resolution facilitates the future expansion of IR-MALDESI applications to include those that require fine structural detail.

Investigating the mechanism of interactive regulation of B-cell lymphoma-2/Beclin 1 through electroacupuncture intervention during reperfusion in myocardial ischemia-reperfusion injury in a rat model

To observe the regulation of B-cell lymphoma-2 (Bcl-2)/Beclin 1 interaction through electroacupuncture (EA) intervention during reperfusion and to investigate the EA mechanism of apoptosis-autophagy interactive regulation against myocardial ischemia-reperfusion injury (MIRI). A total of 48 adult Sprague Dawley (SD) rats were randomly divided into the sham-operated group (group Sham), the model group (group Model), the EA group (group EA), and the JNK inhibitor (SP600125) group (group JNK), with 12 rats in each group. Biospecimens were collected randomly from six rats in each group four hours after reperfusion. Evans Blue and triphenyl tetrazolium chloride double-staining were applied to observe each group's myocardial damage area and risk area. We collected 4 ml of blood by abdominal aortic method to detect serum troponin cTnI level by enzyme-linked immunosorbent assay (ELISA). For the remaining six in each group, a part of myocardial tissue below the ligation line was stored in 4% paraformaldehyde for immunohistochemistry and TUNEL staining; the other amount of myocardial tissue was detected by Western blotting to determine the expression levels of Bcl-2, Beclin1, and the phosphorylation levels of Thr69, Ser70, and Ser87 in Bcl-2. In results: electroacupuncture (EA) intervention during reperfusion significantly reduced the myocardial infarction area, cTnI level, and myocardial apoptosis, upregulated Bcl-2 expression, downregulated Beclin 1 expression and inhibited phosphorylation levels of Thr69, Ser70, and Ser87 in Bcl-2. We concluded that EA effectively inhibited apoptosis by upregulating Bcl-2 expression and inhibiting the phosphorylation of Thr69, Ser70, and Ser87 in Bcl-2. This reduced the separation of Bcl-2 and Beclin 1, restrains excessive autophagy, alleviates MIRI, and has a protective effect on myocardial tissue.

Developing transmission mode for infrared matrix-assisted laser desorption electrospray ionization mass spectrometry imaging

RATIONALE

The development and characterization of the novel NextGen infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source catalyzed new advancements in IR-MALDESI instrumentation, including the development of a new analysis geometry.

METHODS

A vertically oriented transmission mode (tm)-IR-MALDESI setup was developed and optimized on thawed mouse tissue. In addition, glycerol was introduced as an alternative energy-absorbing matrix for tm-IR-MALDESI because the new geometry does not currently allow for the formation of an ice matrix. The tm geom was evaluated against the optimized standard geometry for the NextGen source in reflection mode (rm).

RESULTS

It was found that tm-IR-MALDESI produces comparable results to rm-IR-MALDESI after optimization. The attempt to incorporate glycerol as an alternative matrix provided little improvement to tm-IR-MALDESI ion abundances.

CONCLUSIONS

This work has successfully demonstrated the adaptation of the NextGen IR-MALDESI source through the feasibility of tm-IR-MALDESI mass spectrometry imaging on mammalian tissue, expanding future biological applications of the method.

Bone mineral density, osteopenia and osteoporosis among US adults with cancer

BACKGROUND

Bone mineral deficits are one of the most common complications in cancer survivors. However, there are no studies evaluating bone mineral density (BMD) and the prevalence of osteopenia and osteoporosis among patients with different types of cancers.

AIM

The objective was to assess BMD and evaluate the prevalence of osteopenia and osteoporosis among US adults with cancer.

DESIGN

A cross-section propensity score matching study.

METHODS

We extracted data from National Health and Nutrition Examination Survey database from 2005 to 2018. We compared BMD in participants with and without cancer which was further analyzed according to cancer type. We conducted logistic regression to evaluate adjusted odds ratios of osteopenia and osteoporosis and determine risk factors for their development.

RESULTS

We found that BMD was significantly higher in participants without cancer than cancer patients. Furthermore, the median BMD of patients with breast cancer or skin cancer (including melanoma) was significantly lower than participants without cancer. People with breast, lung, genitourinary and skin cancers were more likely to incur osteopenia/osteoporosis than those without cancer.

CONCLUSIONS

BMD differs depending upon type in survivors. Individuals with a history of cancer have a poor understanding of osteoporosis and its risk factors. Understanding risk factors in patients with cancers identified in our study may be helpful for preventing osteoporosis and fractures and the development of screening guidelines.

Robust deep learning-based protein sequence design using ProteinMPNN

Although deep learning has revolutionized protein structure prediction, almost all experimentally characterized de novo protein designs have been generated using physically based approaches such as Rosetta. Here, we describe a deep learning-based protein sequence design method, ProteinMPNN, that has outstanding performance in both in silico and experimental tests. On native protein backbones, ProteinMPNN has a sequence recovery of 52.4% compared with 32.9% for Rosetta. The amino acid sequence at different positions can be coupled between single or multiple chains, enabling application to a wide range of current protein design challenges. We demonstrate the broad utility and high accuracy of ProteinMPNN using x-ray crystallography, cryo-electron microscopy, and functional studies by rescuing previously failed designs, which were made using Rosetta or AlphaFold, of protein monomers, cyclic homo-oligomers, tetrahedral nanoparticles, and target-binding proteins.

[Influence of age on advanced neoplasia detection in colorectal cancer screening in population at high risk]

Objective: To compare the detection rate of advanced neoplasia and the number of people needing endoscopy in colorectal cancer screening giving at different starting age in population at high risk. Methods: Based on the screening project of early diagnosis and treatment of colorectal cancer in Jiashan county, Zhejiang province, two rounds of colorectal cancer screening were conducted between January 2007 and December 2020. After excluding participants who were not at high risk or had incomplete information, 27 130 participants and 31 205 participants were finally enrolled in round one and in round two, respectively. The spline analysis based on the generalized additive model was used to describe the trend of detection rate of advanced neoplasia with age. The detection rate and number of people needing endoscopy for the groups with starting age at 50, 45 and 40 years were calculated, and the differences in the detection rate were tested by χ² goodness of fit test. Results: A total of 21 077 (77.69%) participants in round one and 25 249 (80.91%) participants in round two received endoscopy, in whom 1 097 (detection rate=52.05‰) and 1 151 (detection rate=45.59‰) had advanced neoplasia (cancers and advanced adenomas), respectively. The detection rate increased significantly with age, and the detection rate in round one were significantly higher than that in round two (P<0.05). The overall detection rates of advanced neoplasia for the groups with starting age at 50, 45 and 40 years were 61.11‰, 56.14‰ and 52.05‰ in round one, and 49.10‰, 46.75‰ and 45.59‰ in round two, respectively. The rates were significantly higher for the group with starting age at 50 years than that with starting age at 40 years in both round one and round two (P<0.05). The numbers of people needing endoscopy of advanced neoplasia for the groups with starting age at 50, 45 and 40 years were 17, 18, and 20 in round one, and 21, 22 and 22 in round two. Conclusions: The detection rate of advanced neoplasia increased with age. Starting screening at lower age might contribute to decreased detection rate and increased number of people needing endoscopy. However, the difference was limited.

[Influence of age on advanced neoplasia detection in colorectal cancer screening in population at high risk]

Objective: To compare the detection rate of advanced neoplasia and the number of people needing endoscopy in colorectal cancer screening giving at different starting age in population at high risk. Methods: Based on the screening project of early diagnosis and treatment of colorectal cancer in Jiashan county, Zhejiang province, two rounds of colorectal cancer screening were conducted between January 2007 and December 2020. After excluding participants who were not at high risk or had incomplete information, 27 130 participants and 31 205 participants were finally enrolled in round one and in round two, respectively. The spline analysis based on the generalized additive model was used to describe the trend of detection rate of advanced neoplasia with age. The detection rate and number of people needing endoscopy for the groups with starting age at 50, 45 and 40 years were calculated, and the differences in the detection rate were tested by χ² goodness of fit test. Results: A total of 21 077 (77.69%) participants in round one and 25 249 (80.91%) participants in round two received endoscopy, in whom 1 097 (detection rate=52.05‰) and 1 151 (detection rate=45.59‰) had advanced neoplasia (cancers and advanced adenomas), respectively. The detection rate increased significantly with age, and the detection rate in round one were significantly higher than that in round two (P<0.05). The overall detection rates of advanced neoplasia for the groups with starting age at 50, 45 and 40 years were 61.11‰, 56.14‰ and 52.05‰ in round one, and 49.10‰, 46.75‰ and 45.59‰ in round two, respectively. The rates were significantly higher for the group with starting age at 50 years than that with starting age at 40 years in both round one and round two (P<0.05). The numbers of people needing endoscopy of advanced neoplasia for the groups with starting age at 50, 45 and 40 years were 17, 18, and 20 in round one, and 21, 22 and 22 in round two. Conclusions: The detection rate of advanced neoplasia increased with age. Starting screening at lower age might contribute to decreased detection rate and increased number of people needing endoscopy. However, the difference was limited.

Thyroid dysfunction during PD‑1 inhibitor treatment in patients with cancer: Incidence and association with progression‑free survival

The use of programmed cell death-1 (PD-1) inhibitors has recently been approved in China. As a consequence, the identification of relevant prognostic markers that can assess the efficacy of these compounds is required. Therefore, the present study aimed to explore the incidence of thyroid dysfunction and its ability to predict progression-free survival (PFS) in Chinese patients with cancer who received PD-1 inhibitor treatment. Data from 72 patients with cancer who received treatment with PD-1 inhibitors alone or in combination with chemotherapy or targeted drugs were analyzed. Moreover, the expression levels of free triiodothyronine, thyroxine, and thyrotropin during treatment were assessed to evaluate thyroid dysfunction. A total of 26 (36.1%) patients who had received PD-1 inhibitors developed thyroid dysfunction. Specifically, the incidence of thyroid dysfunction was 35.6% in patients with lung cancer, 25.0% in patients with malignant melanoma, and 46.7% in patients with other types of cancer. In addition, the median PFS was 7.0 (95% confidence interval, 4.9-9.1) months, whereas the 1- and 2-year PFS rates were 35.1 and 26.2%, respectively. Generally, patients with thyroid dysfunction exhibited longer PFS compared with those without thyroid dysfunction (P=0.001). Subgroup analyses were subsequently performed, which demonstrated that thyroid dysfunction was associated with longer PFS in patients with malignant melanoma (P=0.039) and other types of cancer (P=0.002), but not in those with lung cancer (P=0.083). These findings were noted in patients who received PD-1 inhibitor monotherapy (P=0.003), but not PD-1 inhibitor plus chemotherapy (P=0.172) or PD-1 inhibitor plus targeted therapy (P=0.582). Finally, thyroid dysfunction [P=0.001; hazard ratio (HR)=0.260] and PD-1 inhibitor monotherapy (P=0.015; HR=2.231) were identified as independent factors that could predict PFS. In conclusion, the present study demonstrated that thyroid dysfunction during PD-1 inhibitor treatment could be used as a potential marker for the prognosis of favorable PFS in patients with cancer.

Effects of residual feed intake divergence on growth performance, carcass traits, meat quality, and blood biochemical parameters in small-sized meat ducks

Feed efficiency (FE) is a major economic trait of meat duck. This study aimed to evaluate the effects of residual feed intake (RFI) divergence on growth performance, carcass traits, meat quality, and blood biochemical parameters in small-sized meat ducks. A total of 500 healthy 21-day-old male ducks were housed in individual cages until slaughter at 63 d of age. The growth performance was determined for all the ducks. The carcass yield, meat quality, and blood biochemical parameters were determined for the selected 30 high-RFI (HRFI) and 30 low-RFI (LRFI) ducks. In terms of growth performance, the RFI, feed conversion ratio (FCR), and average daily feed intake (ADFI) were found to be significantly lower in the LRFI group (P < 0.01), whereas no differences were observed in the BW and body weight gain (P > 0.05). For slaughter performance, no differences were observed in the carcass traits between the LRFI and HRFI groups (P > 0.05). For meat quality, the shear force of breast muscle was significantly lower in the LRFI group (P < 0.05), while the other meat quality traits of breast and thigh muscles demonstrated no differences (P > 0.05). For blood biochemical parameters, the serum concentrations of triglycerides (TG) and glucose (GLU) were significantly lower in the LRFI group (P < 0.05), while the other parameters showed no differences (P > 0.05). The correlation analysis demonstrated a high positive correlation between RFI, FCR, and ADFI (P < 0.01). The RFI demonstrated a negative effect on the breast muscle and lean meat yields, but a positive effect on the shear force of breast muscle (P < 0.05). Further, the RFI demonstrated a positive effect on the TG and GLU levels (P < 0.05). These results indicate that the selection for low RFI could improve the FE of small-sized meat ducks without affecting the production performance. This study provides valuable insight into the biological processes underlying the variations in FE in small-sized meat ducks.

Observation of Spin Splitting Torque in a Collinear Antiferromagnet RuO_{2}

Current-induced spin torques provide efficient data writing approaches for magnetic memories. Recently, the spin splitting torque (SST) was theoretically predicted, which combines advantages of conventional spin transfer torque (STT) and spin-orbit torque (SOT) as well as enables controllable spin polarization. Here we provide the experimental evidence of SST in collinear antiferromagnet RuO_{2} films. The spin current direction is found to be correlated to the crystal orientation of RuO_{2} and the spin polarization direction is dependent on (parallel to) the Néel vector. These features are quite characteristic for the predicted SST. Our finding not only presents a new member for the spin torques besides traditional STT and SOT, but also proposes a promising spin source RuO_{2} for spintronics.

[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.

Using Proteomic Approaches to Unravel the Response of Ctenocephalides felis felis to Blood Feeding and Infection With Bartonella henselae

Among the Ctenocephalides felis felis-borne pathogens, Bartonella henselae, the main aetiological agent of cat scratch disease (CSD), is of increasing comparative biomedical importance. Despite the importance of B. henselae as an emergent pathogen, prevention of the diseases caused by this agent in cats, dogs and humans mostly relies on the use of ectoparasiticides. A vaccine targeting both flea fitness and pathogen competence is an attractive choice requiring the identification of flea proteins/metabolites with a dual effect. Even though recent developments in vector and pathogen -omics have advanced the understanding of the genetic factors and molecular pathways involved at the tick-pathogen interface, leading to discovery of candidate protective antigens, only a few studies have focused on the interaction between fleas and flea-borne pathogens. Taking into account the period of time needed for B. henselae replication in flea digestive tract, the present study investigated flea-differentially abundant proteins (FDAP) in unfed fleas, fleas fed on uninfected cats, and fleas fed on B. henselae-infected cats at 24 hours and 9 days after the beginning of blood feeding. Proteomics approaches were designed and implemented to interrogate differentially expressed proteins, so as to gain a better understanding of proteomic changes associated with the initial B. henselae transmission period (24 hour timepoint) and a subsequent time point 9 days after blood ingestion and flea infection. As a result, serine proteases, ribosomal proteins, proteasome subunit α-type, juvenile hormone epoxide hydrolase 1, vitellogenin C, allantoinase, phosphoenolpyruvate carboxykinase, succinic semialdehyde dehydrogenase, glycinamide ribotide transformylase, secreted salivary acid phosphatase had high abundance in response of C. felis blood feeding and/or infection by B. henselae. In contrast, high abundance of serpin-1, arginine kinase, ribosomal proteins, peritrophin-like protein, and FS-H/FSI antigen family member 3 was strongly associated with unfed cat fleas. Findings from this study provide insights into proteomic response of cat fleas to B. henselae infected and uninfected blood meal, as well as C. felis response to invading B. henselae over an infection time course, thus helping understand the complex interactions between cat fleas and B. henselae at protein levels.

Measurement of synovium and serum dual specificity phosphatase 22 level: Their inter-correlation and potency as biomarkers in rheumatoid arthritis

Background

Dual specificity phosphatase 22 (DUSP22), also named as Jun N‐terminal kinase pathway associated phosphatase recently, is reported to be closely engaged in immune and inflammation regulation. This study aimed to investigate the interaction between synovium DUSP22 and serum DUSP22 levels and to explore their correlation with rheumatoid arthritis (RA) risk, inflammation, and disease activity.

Methods

Synovium and serum samples from 42 RA patients with knee involvement underwent arthroscopy, and 20 knee trauma patients were collected. Besides, serum samples from 40 healthy controls were also obtained. Synovium DUSP22 expression was detected by reverse transcription quantitative polymerase chain reaction, while serum DUSP22 level was detected by enzyme‐linked immunosorbent assay.

Results

Synovium DUSP22 level was greatly decreased in RA patients compared to trauma controls (p < 0.001), and it was negatively correlated with tender joint count (TJC) (r = −0.318, p = 0.040), C‐reactive protein (CRP) (r = −0.330, p = 0.033), and Lysholm score (r = −0.423, p = 0.005) in RA patients. Serum DUSP22 level was lowest in RA patients, followed by trauma controls, then highest in healthy controls (p < 0.001). Serum DUSP22 level was negatively associated with TJC (r = −0.438, p = 0.004), swollen joint count (SJC) (r = −0.372, p = 0.015), CRP (r = −0.391, p = 0.011), and disease activity score in 28 joints (DAS28_ESR) score (r = −0.406, p = 0.008), and it increased after treatment (p = 0.001) in RA patients. In addition, serum DUSP22 level positively related to synovium DUSP22 level in RA patients (r = 0.394, p = 0.010).

Conclusion

Synovium and serum DUSP22 are intercorrelated and insufficiently expressed in RA patients; meanwhile, their deficiency correlates with increased systemic inflammation, disease activity, and joint dysfunction.

Alcohol intake and the risk of chronic kidney disease: results from a systematic review and dose-response meta-analysis

Many prospective cohort studies have investigated the association between the consumption of alcohol and CKD risk and have revealed inconsistent results. In the present study, we aimed to perform a meta-analysis of these studies to assess this association.We searched the PubMed and Embase databases up to 2020 and reviewed the reference lists of relevant articles to identify appropriate studies. We calculated the pooled relative risks with 95% CIs using random effects models, and then performed subgroup and meta-regression analyses. Dose-response meta-analyses were performed by sex separately. We identified 25 eligible prospective cohort studies, including 514,148 participants and 35,585 incident CKD cases. Compared with the category of minimal alcohol intake, light (RR = 0.90, I2 = 49%), moderate (RR = 0.86, I2 = 40%), and heavy (RR = 0.85, I2 = 51%) alcohol intake were associated with a lower risk of CKD. Subgroup meta-analysis by sex indicated that light (RR = 0.92, I2 = 0%), moderate (RR = 0.83, I2 = 39%) and heavy (RR = 0.76, I2 = 40%), alcohol consumption were inversely associated with CKD risk in male. Dose-response meta-analyses detected a nonlinear inverse association between alcohol consumption and the risk of CKD in all participants and linear inverse association in female participants. This meta-analysis shows that light (<12 g/day), moderate (12-24 g/day), and heavy (>24 g/day) alcohol consumption are protective against chronic kidney disease in adult participants especially in males.

Three-dimensional (3D) imaging of lipids in skin tissues with infrared matrix-assisted laser desorption electrospray ionization (MALDESI) mass spectrometry

Three-dimensional (3D) mass spectrometry imaging (MSI) has become a growing frontier as it has the potential to provide a 3D representation of analytes in a label-free, untargeted, and chemically specific manner. The most common 3D MSI is accomplished by the reconstruction of 2D MSI from serial cryosections; however, this presents significant challenges in image alignment and registration. An alternative method would be to sequentially image a sample by consecutive ablation events to create a 3D image. In this study, we describe the use of infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) in ablation-based 3D MSI for analyses of lipids within fresh frozen skin tissue. Depth resolution using different laser energy levels was explored with a confocal laser scanning microscope to establish the imaging parameters for skin. The lowest and highest laser energy level resulted in a depth resolution of 7 μm and 18 μm, respectively. A total of 594 lipids were putatively detected and detailed lipid profiles across different skin layers were revealed in a 56-layer 3D imaging experiment. Correlated with histological information, the skin structure was characterized with differential lipid distributions with a lateral resolution of 50 μm and a z resolution of 7 μm.

[Aldo-keto reductase family 1 B10 participates in the regulation of hepatoma cell cycle through p27/p-Rb signaling pathway]

Objective: Aldo-keto reductase family 1 member B10 (AKR1B10) pathogenesis, early diagnosis and prognosis are closely related with hepatoma. Therefore, this study explores the effect and mechanism of AKR1B10 on cell cycle in hepatoma cells. Methods: HepG2 cells were infected with lentivirus LV-AKR1B10-shRNA or treated with epalrestat, an AKR1B10 inhibitor. The expression level of AKR1B10 was detected by Western blot assay and real-time fluorescence quantitative PCR (RT-qPCR). Decreased AKR1B10 activity was detected by reduced coenzyme II (NADPH) absorbance at 340 nm. The low expression of AKR1B10 and the effect of different concentrations of epalrestat on cell proliferation and cell cycle were detected by CCK-8 method and flow cytometry. The protein expression levels of p-rb, cyclin D1, E1, p27 in HepG2 cells were detected by Western blot. The mean of the two samples was tested using independent sample t-test. Results: AKR1B10 expression level in hepatoma cells was significantly increased compared to normal liver cells, and the relative expression level of AKR1B10 protein in HepG2 cells was 6.71 ± 1.11 (P = 0.012). Epalrestat was significantly inhibited with the enzymatic activity of AKR1B10 in a dose-dependent manner. AKR1B10 gene in HepG2 cells was effectively silenced. HepG2 cells treated with different concentrations of epalrestat (AKR1B10 inhibitor) for 24, 48 and 72 h had inhibited cell proliferation, promoted G0/G1 cell cycle arrest, reduced the expression of p-Rb, cyclin D1, and cyclin E1 and increased the expression of cyclin dependent kinase inhibitor p27 expression. Conclusion: AKR1B10 inhibitory expression and activity can promote G0/G1 cell cycle arrest in HepG2 cells through the p27 / p-Rb pathway.

[Thyroid disruptor p, p'-DDE inhibited the expression of LHX4 and DIS3L protein in Nthy-ori-3-1 cells]

Objective: To observe the changes of LHX4 and DIS3L mRNA and protein expression in Nthy-ori-3-1 cells after the treatment of thyroid disruptor p, p'-DDE. Methods: Nthy-ori-3-1 cells in logarithmic growth phase were treated with 0, 0.5, 1.0, 2.0 and 5.0 μg/ml p, p'-DDE solution. The growth state and morphology of the cells were observed by microscope. The mRNA levels of LHX4 and DIS3L were detected by real-time fluorescent quantitative PCR, and the protein expression levels of LHX4 and DIS3L were detected by Western blot. Results: when the concentrations of p, p'-DDE were 0, 0.5, 1.0 and 2.0 μg/ml, Nthy-ori-3-1 cells grew normally. There were 33 differential genes in 2.0 μg/ml group, among which 13 genes were down regulated and 20 genes were up-regulated. Compared with the control group, the protein expression levels of LHX4 and DIS3L in 1.0 and 2.0 μg/ml groups were significantly decreased (P<0.05) , and the relative expression levels of LHX4 and DIS3L protein mRNA in 1.0 μg/ml group were significantly decreased (P<0.05) . Conclusion: p, p'-DDE can affect the protein expression of LHX4 and dis3l in nthy-ori-3-1 cells.

[Efficacy and safety of generic azacitidine in Chinese patients with higher-risk myelodysplastic syndromes: a multicenter, prospective, single-arm study]

Objective: To evaluate the efficacy, safety, and pharmacokinetics of the generic azacitidine in Chinese patients with higher-risk myelodysplastic syndromes(MDS). Methods: Between October 2013 and 2016, 72 patients were eligible for enrollment at 9 sites from China received generic subcutaneous azacitidine 75 mg·m(-2)·d(-1) for 7 days per 28-day cycle, for ≥6 cycles. Pharmacokinetic blood samples were collected on day 1 of a single-dose. Results: For each patient at cycle 6 or at the time of study discontinuation, whichever came first, the overall response rate, which included complete remission (CR)and partial remission(PR), was 6.9%(5/72), the rate of patients who had the best effect with CR or PR during the treatment was 12.5%(9/72). Patients who were dependent on red-blood-cell transfusions and platelet transfusions at baseline became transfusion independent were 46.3%(19/41)and 41.2% (7/17), respectively. The median time of treatment was 6 cycles, and the median OS was 16.1 months (95%CI 10.9-20.6 months). For 36 patients(50%)received treatment at ≥6 cycles, and the median OS was 22.3 months(95%CI 16.1- not evaluative). Most common grade Ⅲ-Ⅳ hematologic treatment-emergent adverse events were neutropenia(55%), leukopenia(47%), and thrombocytopenia(61%). Pharmacokinetic profiles were similar for generic and original azacitidine in Chinese patients. Conclusion: Generic azacitidine treatment was favorable and safe and can be used as a standard treatment for patients with higher-risk MDS.

[Quick community survey on the impact of COVID-19 outbreak for the healthcare of people living with HIV]

Objective: To collect the current status and healthcare needs of people living with HIV (PLHIV) in China during the COVID-19 outbreak to inform quick response from government and communities. Methods: During February 5(th) to 10(th), 2020, a national anonymous survey was conducted using an online questionnaire among PLHIV at least 18 years of age and had started antiretroviral treatment (ART) to collect the information on COVID-19 prevention, HIV-related health services and the needs on psychosocial support. Current status and needs of people living with HIV were analyzed in Hubei and other regions. Results: A total of 1 014 valid questionnaires were collected, with PLHIV respondents cross the country. The survey revealed that 93.79% of the respondents could obtain information regarding the prevention of COVID-19 from their communities or villages. Respondents were concerned with HIV-specific protective measures and personal protective equipment shortage. 32.64% of all respondents were not carrying sufficient antiretroviral medicines (ARVs) to meet the needs under traffic and travel restrictions, and some could face stock-outs in the coming month. In Hubei province where 53 respondents needed ARV refill, 64.15% reported difficulty accessing ARV due to the "blockage" . 28.93% respondents were in need of sociopsychological support, and 85.31% anticipated further improvement of the out-of-town ARV refill process from the government. Conclusion: PLHIV wants to know HIV-specific protective measures against COVID-19 outbreak. PLHIV who returned to their home-towns and affected by the lock-downs reported challenges with refills. We should undertake a more systematic study on impacts of the COVID-19 on PLHIV to develop preparedness capacity for future public health emergency.

Short communication: Menaquinone-4 (vitamin K2) induces proliferation responses in bovine peripheral blood mononuclear cells

The effects of vitamin K (VK) on immune cells in ruminants are yet to be fully investigated. The objective of this study was to examine the effects of VK on peripheral blood mononuclear cells (PBMC) in Holstein dairy cows. A cell proliferation assay was performed to evaluate the effect of menaquinone-4 (MK-4, the biologically active form of VK) on immune response of PBMC. The proliferation of PBMC stimulated by MK-4 was significantly higher than that of nonstimulated controls. The expression of T cell-related genes in PBMC, stimulated with MK-4, was assessed by quantitative PCR. No significant changes were observed in the mRNA expression levels of both CD4 and CD8 as helper T cell and cytotoxic T cell markers, respectively. The present study demonstrated that MK-4 positively influenced cow PBMC proliferation and suggested the possibility of bovine-specific immune cell activation. The present study lays a foundation for understanding the physiological role of VK in cattle.

[Individualized treatment recommendations for lung cancer patients at different stages of treatment during the outbreak of 2019 novel coronavirus disease]

In order to achieve the overall victory over 2019 novel coronavirus disease epidemic, especially to prevent the disease recurrence from rebounding during the resumption of labor, the government has not loosened any control of personnel mobility, which has obviously affected the normal examination and treatment of lung cancer patients under the influence of this epidemic. During the epidemic period, cancer patients with low immunity levels face the double ordeals of disease and epidemic situation. Compared with the general population, they are more likely to be infected with the new coronavirus. Among the infected cancer patients, lung cancer is the most common type. It is necessary to provide more appropriate individualized treatment recommendations for patients with lung cancer based on the epidemic situation of the patient's location and in combination with the patient's own condition. Through active prevention of infection, timely conversion of treatment strategies, online and offline joint control, and positive psychological counseling, we do our best to help patients with lung cancer to survive this difficult period.

Research Note: Effects of the rearing method and stocking density on carcass traits and proximate composition of meat in small-sized meat ducks

The present study was conducted to evaluate the effects of different rearing methods and stocking densities on carcass yield and proximate composition of meat in small-sized meat ducks. A total of 555 one-day-old birds were randomly allocated to six treatment groups (three replicates per treatment, sex ratio 1/1) with a 2 × 3 factorial arrangement of two rearing methods (reared in cage or net) and three stocking densities (5 [low], 7 [medium], or 9 [high] birds/m²) until day 70. Five male and five female birds from each replicate were randomly selected and processed to determine the carcass yield. Proximate composition was determined by proximate analysis using the breast and thigh muscles. There was no interaction effect between the rearing method and stocking density on carcass yield. The rearing method affected the thigh muscle rate, which was higher in the cage groups (P < 0.05). The final BW and abdominal fat rate decreased with increasing density (P < 0.05), whereas the thigh muscle rate increased (P < 0.05). There were significant interaction effects (P < 0.05) between the rearing method and stocking density on the content of protein, fat, and collagen. The content of fat and moisture was greater and lower, respectively, in the cage groups (P < 0.05). The content of moisture, fat, and collagen with a medium density was higher (P < 0.05). In addition, the content of protein and fat was lower in the ducks fed in nets at low and high densities (P < 0.05), respectively; the collagen content of breast and thigh muscle was lower in the ducks fed in cages and nets, respectively, at a low density (P < 0.05). Our findings provide valuable insights into the single and interactive effects of the rearing method and stocking density on duck slaughter performance and proximate composition of meat. The results indicate that a rearing system with a cage pattern and a medium density is better than other arrangements for small-sized meat ducks.