LC-MS bioanalysis of protein biomarkers and protein therapeutics in formalin-fixed paraffin-embedded tissue specimens

Formalin-fixed paraffin-embedded (FFPE) is a form of preservation and preparation for biopsy specimens. FFPE tissue specimens are readily available as part of oncology studies because they are often collected for disease diagnosis or confirmation. FFPE tissue specimens could be extremely useful for retrospective studies on protein biomarkers because the samples preserved in FFPE blocks could be stable for decades. However, LC-MS bioanalysis of FFPE tissues poses significant challenges. In this Perspective, we review the benefits and recent developments in LC-MS approach for targeted protein biomarker and protein therapeutic analysis using FFPE tissues and their clinical and translational applications. We believe that LC-MS bioanalysis of protein biomarkers in FFPE tissue specimens represents a great potential for its clinical applications.

Cytomegalovirus Infection and Alzheimer's Disease: A Meta-Analysis

BACKGROUND

Evidence on the association of cytomegalovirus (CMV) infection with Alzheimer's disease (AD) is scarce and the results are inconsistent.

OBJECTIVE

To investigate the association of CMV infection with the risk of AD.

METHODS

Observational studies on the relationship between CMV infection and AD were identified from PubMed, Embase, Web of Science, and the Cochrane Library until September 30, 2022. The quality of included studies was assessed using the Newcastle-Ottawa Scale. Random-effect meta-analysis was performed using a generic inverse-variance method, followed by sensitivity analyses and subgroup analyses based on study designs, regions, adjustments, and population types.

RESULTS

Our search yielded 870 articles, of which 200 were duplicates and 663 did not meet the inclusion criteria, and finally yielded seven studies with 6,772 participants. No strong evidence was observed in the summary analysis for the association of CMV infection and risk of AD (odds ratio [OR] = 1.33; 95% confidence interval [CI]: 0.88, 2.03, I2 =69.9%). However, subgroup analysis showed that an increased risk of AD was detected in East Asians (OR = 2.39; 95% CI: 1.63, 3.50, I2 = 0.00%), cohort studies (OR = 1.99; 95% CI: 1.35, 2.94, I2 = 28.20%), and studies with confounder adjustment (OR = 2.05; 95% CI: 1.52, 2.77, I2 = 0.00%).

CONCLUSIONS

This meta-analysis provides evidence to support the heterogeneity of the associations between CMV infection and AD. Future studies with larger sample sizes and multi-ethnic populations are necessary.

2022 White Paper on Recent Issues in Bioanalysis: ICH M10 BMV Guideline & Global Harmonization; Hybrid Assays; Oligonucleotides & ADC; Non-Liquid & Rare Matrices; Regulatory Inputs (Part 1A - Recommendations on Mass Spectrometry, Chromatography and Sample Preparation, Novel Technologies, Novel Modalities, and Novel Challenges, ICH M10 BMV Guideline & Global Harmonization Part 1B - Regulatory Agencies' Inputs on Regulated Bioanalysis/BMV, Biomarkers/CDx/BAV, Immunogenicity, Gene & Cell Therapy and Vaccine)

The 16th Workshop on Recent Issues in Bioanalysis (16th WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on the ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1A) covers the recommendations on Mass Spectrometry and ICH M10. Part 1B covers the Regulatory Agencies' Inputs on Bioanalysis, Biomarkers, Immunogenicity, Gene & Cell Therapy and Vaccine. Part 2 (LBA, Biomarkers/CDx and Cytometry) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 15 of Bioanalysis, issues 15 and 14 (2023), respectively.

[Construction of a prognostic model for hepatocellular carcinoma based on pyroptosis-related genes]

Objective: To study the construction of a prognostic model for hepatocellular carcinoma (HCC) based on pyroptosis-related genes (PRGs). Methods: HCC patient datasets were obtained from the Cancer Genome Atlas (TCGA) database, and a prognostic model was constructed by applying univariate Cox and least absolute shrinkages and selection operator (LASSO) regression analysis. According to the median risk score, HCC patients in the TCGA dataset were divided into high-risk and low-risk groups. Kaplan-Meier survival analysis, receiver operating characteristic (ROC) curves, univariate and multivariate Cox analysis, and nomograms were used to evaluate the predictive ability of the prognostic models. Functional enrichment analysis and immune infiltration analysis were performed on differentially expressed genes between the two groups. Finally, two HCC datasets (GSE76427 and GSE54236) from the Gene Expression Omnibus database were used to externally validate the prognostic value of the model. Univariate and multivariate Cox regression analysis or Wilcoxon tests were performed on the data. Results: A total of 366 HCC patients were included after screening the HCC patient dataset obtained from the TCGA database. A prognostic model related to HCC was established using univariate Cox regression analysis, LASSO regression analysis, and seven genes (CASP8, GPX4, GSDME, NLRC4, NLRP6, NOD2, and SCAF11). 366 cases were evenly divided into high-risk and low-risk groups based on the median risk score. Kaplan-Meier survival analysis showed that there were statistically significant differences in the survival time between patients in the high-risk and low-risk groups in the TCGA, GSE76427, and GSE54236 datasets (median overall survival time was 1 149 d vs. 2 131 d, 4.8 years vs. 6.3 years, and 20 months vs. 28 months, with P = 0.000 8, 0.034 0, and 0.0018, respectively). ROC curves showed good survival predictive value in both the TCGA dataset and two externally validated datasets. The areas under the ROC curves of 1, 2, and 3 years were 0.719, 0.65, and 0.657, respectively. Multivariate Cox regression analysis showed that the risk score of the prognostic model was an independent predictor of overall survival time in HCC patients. The risk model score accurately predicted the survival probability of HCC patients according to the established nomogram. Functional enrichment analysis and immune infiltration analysis showed that the immune status of the high-risk group was significantly decreased. Conclusion: The prognostic model constructed in this study based on seven PRGs accurately predicts the prognosis of HCC patients.

[Prediction of protection probability against Omicron BA.1, BA.4 and BA.5 variants in symptomatic infections with prototype strain based on neutralization antibody levels]

Objective: To predict the protection probability of different clinical outcomes after reinfection with Omicron variant in symptomatic and unvaccinated COVID-19 patients who infected with prototype strain. Methods: The data used in this study were derived from a systematic review and meta-analysis which systematically searched PubMed, Embase, Web of Science, and Europe PMC databases, included published and uploaded studies of dynamic changes of neutralizing antibodies in symptomatic COVID-19 patients from 1 January 2020 to 2 October 2022 and extracted the literature information, study design, serological experiment information and antibody results. According to the scatter distribution characteristics of antibody titer data, a generalized additive model based on Gaussian distribution was used to fit the titer value of neutralizing antibody based on logarithmic conversion and the dynamic change pattern of neutralizing antibody in symptomatic and unvaccinated COVID-19 patients infected with prototype strain over time was obtained. In this study, the fitted antibody titers of patients on the 28th, 51st, and 261st day after symptom onset was selected to predict the protection probability. Results: Neutralizing antibodies produced in symptomatic and unvaccinated patients infected with prototype strain could provide protection against Omicron reinfection, and the probability of protection gradually decreased with time. Neutralizing antibody level on day 28 after symptom onset provided protection probability of 30.3% (95%CI: 20.0%-45.5%) against reinfection, 51.5% (95%CI: 33.4%-75.9%) against symptomatic reinfection, and 91.2% (95%CI: 77.1%-97.7%) against severe reinfection caused by Omicron BA.5. The protection probability against Omicron BA.1, BA.4 and BA.5 reinfections decreased significantly 261 days after symptom onset, showing 9.6%-12.9%, 18.4%-23.9% and 63.1%-70.3% against three clinical outcomes, respectively. At the same time point and against the same clinical outcome, the protection probability of BA.1 was the highest, followed by BA.4 and BA.5. Conclusions: Neutralizing antibodies induced in symptomatic and unvaccinated COVID-19 patients previously infected with the prototype strain have limited protection probability against Omicron BA.5 reinfections and symptomatic reinfections. The protection probability against Omicron BA.5 reinfections is 30.3% 28 days after symptom onset and decreases to about 10% after 261 days. However, the protection probability against severe reinfections is considerable, with over 90% 28 days after symptom onset and still exceeding 60% after 261 days.

Ultrasound Fusion-Guided Core Needle Biopsy for Deep Head and Neck Space Lesions: Technical Feasibility, Histopathologic Yield, and Safety

BACKGROUND AND PURPOSE

Ultrasound is generally considered to have a minor role in guiding biopsies for deep head and neck space lesions. However, the ultrasound fusion technique may have the potential to change this opinion. This study evaluated the feasibility, histopathologic yield, and safety of ultrasound fusion-guided core needle biopsies for deep head and neck space lesions.

MATERIALS AND METHODS

From March 2021 to April 2022, patients with primary deep head and neck space lesions were prospectively included in this study. Ultrasound fusion was performed with contemporaneous CT, MR imaging, or PET/CT studies, and ultrasound fusion-guided core needle biopsy was performed by using a Micro-Convex probe via 4 different needle approaches. Feasibility, histopathologic results, and biopsy-related complications were observed. Descriptive statistics were applied.

RESULTS

Ultrasound-guided biopsy was feasible in all 16 patients (11 women and 5 men; mean age 46 [SD, 16] years; range, 16-76 years). The lesions were located in the parapharyngeal space, infratemporal fossa, and skull base, with a median diameter of 3.8 cm (range, 2.2-6.5 cm). An adequate and definite histopathologic yield was obtained in 15/16 (93.8%) patients; among them, 4/15 lesions (26.7%) were malignant, and 11/15 (73.6%) were benign. No major complications occurred. Minor complications were noted in 2 of the 16 (12.5%) patients (self-limiting inflammation in 1 and bleeding in 1).

CONCLUSIONS

This study demonstrates that ultrasound fusion-guided biopsy of deep head and neck space lesions is feasible and safe, with a high histopathologic yield.

Ectopic thymic carcinoma of the parotid gland

Ectopic thymic carcinoma (ETC) of the parotid gland is a rare entity. This report describes the case of a 52-year-old man with a painless mass in the right parotid gland. Magnetic resonance imaging (MRI) showed a biphasic mass consisting of a central segment and a peripheral segment. The patient underwent a superficial parotidectomy, and point-to-point correspondence sampling for analysis based on MRI findings was performed. The pathological finding was ETC, and there was an excellent association between MRI characteristics and histopathological findings. Subsequently, the patient underwent postoperative radiation therapy. At the 9-month follow-up, he had recovered well without facial paralysis, and there was no evidence of recurrence or metastasis. This report describes the clinical, radiological, and pathological features of the ETC.

Inhibitory effects of lactoferrin on pulmonary inflammatory processes induced by lipopolysaccharide by modulating the TLR4-related pathway

This study tested the ability of lactoferrin to modulate pulmonary inflammation. To construct in vitro and in vivo inflammatory lung models, cells from the human lung adenocarcinoma cell line (A549) were exposed to lipopolysaccharide (LPS, 1 µg/mL), and mice (CD-1) were intratracheally administered LPS [10 mg/kg of body weight (BW), tracheal lumen injection], respectively. The A549 cells were preincubated with lactoferrin (10 mg/mL), and the mice were intraperitoneally injected with lactoferrin (100 mg/kg of BW), followed by LPS treatment. The concentrations of proinflammatory cytokines (IL-1β and TNF-α) in culture medium of A549 cells and in bronchoalveolar lavage fluid of the mice were determined using enzyme-linked immunosorbent assays. The toll-like receptor 4-related pathway (TLR4/MyD88/IRAK1/TRAF6/NFκB) was determined at gene and protein expression levels in A549 cells and mouse lung tissue. Results showed that LPS treatment significantly elevated the concentrations of IL-1β and TNF-α in the A549 cell culture medium and in bronchoalveolar lavage fluid of the mice; it also elevated both the mRNA and protein expressions of TLR4 and the TLR4 downstream factors in A549 cells and mouse lung tissue. Nevertheless, lactoferrin apparently depressed the releases of IL-1β and TNF-α from A549 cells and lung tissues stimulated by LPS, and significantly suppressed the TLR4 signaling pathway. Lactoferrin also promoted the enhancement of miR-146a expression in A549 cells and mouse lung tissue. Moreover, 100°C heating for 3 min caused total loss of the previously listed bioactivity of lactoferrin. Collectively, we proved that lactoferrin intervened in LPS-induced inflammation in the pulmonary cell model and in the mouse model, through inhibiting the TLR4-related pathway.

A triple-classification radiomics model for the differentiation of pleomorphic adenoma, Warthin tumour, and malignant salivary gland tumours on the basis of diffusion-weighted imaging

AIM

To develop and validate a triple-classification radiomics model for the preoperative differentiation of pleomorphic adenoma (PA), Warthin tumour (WT), and malignant salivary gland tumour (MSGT) based on diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Data from 217 patients with histopathologically confirmed salivary gland tumours (100 PAs, 68 WTs, and 49 MSGTs) from January 2015 to March 2019 were analysed retrospectively and divided into a training set (n=173), and a validation set (n=44). A total of 396 radiomic features were extracted from the DWI of all patients. Analysis of variance (ANOVA) and least absolute shrinkage and selection operator (LASSO) regression were used to select radiomic features, which were then constructed using three classification models, namely, logistic regression method (LR), support vector machine (SVM), and K-nearest neighbor (KNN). The diagnostic performance of the radiomics model was quantified by the receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) of the training and validation data sets.

RESULTS

The 20 most valuable features were investigated based on the LASSO regression. LR and SVM methods exhibited better diagnostic ability than KNN for multiclass classification. LR and SVM had the best performance and yielded the AUC values of 0.857 and 0.824, respectively, in the training data set and the AUC values of 0.932 and 0.912, respectively, in the validation data set of MSGT diagnosis.

CONCLUSION

DWI-based triple-classification radiomics model has predictive value in distinguishing PA, WT, and MSGT, which can be used for preoperative auxiliary diagnosis in clinical practice.

Antipeptide Immunocapture with In-Sample Calibration Curve Strategy for Sensitive and Robust LC-MS/MS Bioanalysis of Clinical Protein Biomarkers in Formalin-Fixed Paraffin-Embedded Tumor Tissues

Despite huge promises, bioanalysis of protein biomarkers in formalin-fixed paraffin-embedded (FFPE) tissues by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for clinical applications is still very challenging. Here, we describe a sensitive and robust LC-MS/MS assay to quantify clinical protein biomarkers in FFPE tumor sections using automated antipeptide antibody immunocapture followed by in-sample calibration curve (ISCC) strategy with multiple isotopologue reaction monitoring (MIRM) technique. ISCC approach with MIRM of stable isotopically labeled (SIL) peptides eliminated the need for authentic matrices for external calibration curves, overcame the matrix effects, and validated the quantification range in each individual sample. Specifically, after deparaffinization, rehydration, antigen retrieval, and homogenization, the protein analytes in FFPE tumor tissues were spiked with a known concentration of one SIL peptide for each analyte, followed by trypsin digestion and antipeptide immunocapture enrichment prior to MIRM-ISCC-based LC-MS/MS analysis. This approach has been successfully used for sensitive quantification of programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) in 15 representative FFPE tumor samples from lung, colorectal, and head and neck cancer patients. Except for one sample, PD-L1 and PD-1 in all samples were quantifiable using this assay with concentrations of 27.85-798.43 (amol/μg protein) for PD-L1 and 16.96-129.89 (amol/μg protein) for PD-1. These results were generally in agreement with the immunohistochemistry (IHC) data but with some exceptions. This approach demonstrated the feasibility to quantify low abundant protein biomarkers in FFPE tissues with improved sensitivity, specificity, and robustness and showed great potential as an orthogonal analytical approach to IHC for clinical applications.

Safety, pharmacokinetics and pharmacodynamics of branebrutinib (BMS-986195), a covalent, irreversible inhibitor of Bruton's tyrosine kinase: Randomised phase I, placebo-controlled trial in healthy participants

Aims

Branebrutinib (BMS‐986195) is a potent, highly selective, oral, small‐molecule, covalent inhibitor of Bruton's tyrosine kinase (BTK). This study evaluated safety, pharmacokinetics and pharmacodynamics of branebrutinib in healthy participants.

Methods

This double‐blind, placebo‐controlled, single‐ and multiple‐ascending dose (SAD; MAD) Phase I study (NCT02705989) enrolled participants into 3 parts: SAD, MAD and JMAD (MAD in first‐generation Japanese participants). In each part, participants were randomised 3:1 to receive branebrutinib (SAD: 0.3–30 mg; [J]MAD: 0.3–10 mg) or placebo. Participants in the MAD parts received branebrutinib daily for 14 days and were followed for 14 days postdosing. Safety was assessed by monitoring, laboratory and physical examinations, vital signs, and recording adverse events (AEs). Pharmacodynamics were assessed with a mass spectrometry assay that measured drug‐occupied and free BTK.

Results

The SAD, MAD and JMAD parts of the study included 40, 32 and 24 participants. Branebrutinib was well tolerated and AEs were mild/moderate, except for 1 serious AE that led to discontinuation. Branebrutinib was rapidly absorbed, with maximum plasma concentration occurring within 1 hour and a half‐life of 1.2—1.7 hours, dropping to undetectable levels within 24 hours. BTK occupancy was rapid, with 100% occupancy reached after a single 10‐mg dose. BTK occupancy decayed predictably over time (mean half‐life in MAD panels: 115–154 hours), such that pharmacodynamic effects were maintained after branebrutinib plasma levels fell below the lower limit of quantification.

Conclusion

Rapid and high occupancy of BTK and the lack of notable safety findings support further clinical development of branebrutinib.

Short communication: Decrease of lipid profiles in cow milk by ultra-high-temperature treatment but not by pasteurization

Triglyceride (TG) and fatty acid profiles of raw (RM), pasteurized (PM, 85°C for 15 s), and indirect UHT-treated (UM, 135°C for 15 s) cow milk were investigated by a lipidomics approach. Ninety-four TG were identified and all were present at significantly lower concentrations in UM than in RM or PM, and free fatty acid contents were significantly higher in UM than in RM and PM, indicating that TG lipolysis occurred to a greater degree in UM than in RM and PM. In addition, UM contained significantly fewer unsaturated fatty acids (14 types) than those in RM and PM, including C14:1n-5, C15:1n-5, C16:1n-7, C17:1n-7, C18:1n9 cis, C18:2n-6 cis, C18:3n-3, C18:3n-6, C20:1, C20:2, C20:3n-6, C20:3n-3, C20:4n-6, and C20:5n-3. However, we detected no significant differences between RM and PM in these fatty acids. In conclusion, UHT treatment, but not pasteurization, caused loss of the nutritional quality and bioactivity of cow milk lipid profiles.

Investigation and comparison of the anti-tumor activities of lactoferrin, α-lactalbumin, and β-lactoglobulin in A549, HT29, HepG2, and MDA231-LM2 tumor models

To investigate the anti-tumor activities of lactoferrin, α-lactalbumin, and β-lactoglobulin, 4 types of human tumor cells (lung tumor cell A549, intestinal epithelial tumor cell HT29, hepatocellular cell HepG2, and breast cancer cell MDA231-LM2) were exposed to 3 proteins, respectively. The effects on cell proliferation, migration, and apoptosis were detected in vitro, and nude mice bearing tumors were administered the 3 proteins in vivo. Results showed that the 3 proteins (20 g/L) inhibited viability and migration, as well as induced apoptosis, in 4 tumor cells to different degrees (compared with the control). In vivo, tumor weights in the HT29 group (0.84 ± 0.22 g vs. control 2.05 ± 0.49 g) and MDA231-LM2 group (1.11 ± 0.25 g vs. control 2.49 ± 0.57 g) were significantly reduced by lactoferrin; tumor weights in the A549 group (1.07 ± 0.19 g vs. control 3.11 ± 0.73 g) and HepG2 group (2.32 ± 0.46 g vs. control 3.50 ± 0.74 g) were significantly reduced by α-lactalbumin. Moreover, the roles of lactoferrin, α-lactalbumin, and β-lactoglobulin in regulating apoptotic proteins were validated. In summary, lactoferrin, α-lactalbumin, and β-lactoglobulin were proven to inhibit growth and development of A549, HT29, HepG2, and MDA231-LM2 tumors to different degrees via induction of cell apoptosis.

Determination of sulbactam in raw bovine milk by isotope dilution-ultra-high-performance liquid chromatography-tandem mass spectrometry

We developed a sensitive and selective isotope dilution ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of sulbactam residue in raw bovine milk. Sulbactam and internal standard, sulbactam-d₅, were extracted from raw bovine milk via liquid-liquid extraction and enriched with strong anion exchange solid-phase extraction cartridges and finally analyzed by using UPLC-MS/MS with multiple reaction monitoring mode. The method was validated according to European regulations. The calibration curve showed good linearity, with a correlation coefficient of 0.9998. Decision limit and detection capability of sulbactam were determined by matrix calibration curve and were 0.0445 and 0.0517 μg/L, respectively. The recoveries of sulbactam in fortified raw bovine milk ranged from 72.1 to 91.5%, with the intra- and interday relative standard deviations ranging from 3.0 to 18.9%. Furthermore, the developed method was applied to analyzing real raw bovine milk samples collected from dairy farms in Beijing, China. Sulbactam was not determined in all samples. The proposed method could ultimately serve as a methodological foundation for the determination of sulbactam in different types of raw milk and dairy products.

Antimicrobial resistance and virulence genes of Streptococcus isolated from dairy cows with mastitis in China

Streptococcus is a major mastitis-causing pathogen in dairy cows. To investigate the prevalence, antimicrobial resistance and virulence gene of Streptococcus in mastitic milk, a total of 735 mastitic raw milk samples from dairy cows in 11 provinces of China were collected and tested. Antimicrobial resistance of Streptococcus isolates was determined by disc diffusion against 8 classes 29 antimicrobial agents, and Streptococcus resistant genes and virulence genes were determined by PCR and agarose gel electrophoresis. A total of 64 (8.71%) isolates of Streptococcus were isolated and identified using biochemical profiling, including 22 isolates of Streptococcus agalactiae, 13 isolates of Streptococcus dysgalactiae, and 29 isolates of Streptococcus uberis. Out of 64 resistant Streptococcus isolates, all isolates (100%) were resistant to 3 or more antimicrobials. The most frequency (n = 18, 28.12%) of the isolates were multi-resistant to 5-7 antimicrobials and the highest multi-resistant number was 29 (n = 1, 1.56%). Streptococcus isolates had the highest resistance rate to tetracycline (98.44%) and oxacillin (98.44%), followed by penicillin G (96.88%) and doxycycline (96.88%), and the lowest resistance was observed with respect to ciprofloxacin (1.56%). A total of 16 antimicrobials resistance genes with 25 combination patterns were detected in the isolates. The gene combination of Sul1/Sul2/Sul3 + gyrA/parC + cat1/cat2 was the most common pattern (12.5%). The correlation between resistant phenotypes and resistance genes in Streptococcs was 35.87%. A total of 7 virulence genes were detected and 59 (92.19%) isolates harbored at least one gene. Twenty-four classes of gene patterns were found in the isolates and the patterns of bca (9.38%) and cfb (9.38%) were the most prevalent form. In conclusion, the issue of drug resistance of Streptococcus is still a great concern in cattle health in China.

Transcriptome analysis revealed that aflatoxin M1 could cause cell cycle arrest in differentiated Caco-2 cells

Being a hydroxylated metabolite of aflatoxin B1 (AFB1) and the most threatening aspect of AFB1 contamination, aflatoxin M1 (AFM1) can lead to hepatotoxicity and hepato-carcinogenicity, and possess intestinal cytotoxicity. However, little is known about the potential mechanisms of the extrahepatic effect. The aim of this study was to investigate intestinal dysfunction induced by AFM1 via transcriptome analysis. Gene expression profiling was analyzed to comparatively characterize the differentially expressed genes (DEGs) after differentiated Caco-2 cells were exposed to different concentrations of AFM1 for 48 h. A total of 165 DEGs were significantly clustered into two down-regulated patterns. Protein-protein interaction (PPI) network analysis based on Search Tool for Retrieval of Interacting Genes (STRING)suggested that 23 key enzymes mainly participated in the regulation of the cell cycle. Q-PCR analysis was performed to validate that key 12 genes (BUB1, BUB1B, MAD2L1, CCNA2, RB1, CDK1, ANAPC4, ATM, KITLG, PRKAA2, SIRT1, and SOS1) were involved. This study firstly revealed that the toxicity of AFM1 to intestinal functions may be partly due to the occurrence of cell cycle arrest, which is linked to changes in CDK1, SOS1/Akt, and AMPK signaling molecules.

Furosine induces DNA damage and cell death in selected human cell lines: a strong toxicant to kidney Hek-293 cells

Ne-(2-furoylmethyl)-l-lysine (furosine) is well-known indicator of early stage of Maillard reaction in processed food. Yet the toxicological aspects associated with its exposure remain rarely studied. Here, we investigated the effects of furosine exposure on cell viability, DNA damage, and its mutagenic potential by using MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide), TUNEL assay (Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling assay), and Ames assay techniques on human cell lines, i.e., liver HepG-2, kidney Hek-293, neuronal SK-N-SH, and intestinal Caco-2, respectively. Our results showed that kidney Hek-293 cell line was the most sensitive to furosine exposure as significant reduction in cell viability and induction of DNA damage were observed at 50 mg/L concentration. In contrast, intestinal Caco-2 cell lines showed resistance to furosine exposure as DNA damage was only observed at 800 mg/L concentration of furosine. Ames assay indicated that furosine has no mutagenic effects on TA 100 and TA 1535 strains. Hence, this study suggests that furosine is a strong toxicant for kidney cells.

Evaluation of magnetic resonance imaging in staging of rectal cancer and its relationship with P16 expression

OBJECTIVE

To explore the use of magnetic resonance imaging (MRI) in the staging of rectal cancer and its relationship with p16 expression.

PATIENTS AND METHODS

A total of 75 patients with rectal cancer treated in Oncology Department of our hospital from March 2013 to March 2017 were randomly included in this study. The entire pelvis was scanned by MRI, and clinicopathological staging was diagnosed. Subsequently, all patients underwent total mesorectal excision (TME). Histopathological gold standard [hematoxylin-eosin (HE) staining] was used to determine the stage. Immunohistochemistry (IHC) was adopted to detect the expression of p16 in cancer tissues and cancer-adjacent tissues. Compared with the results of the pathological examination, the accuracy of MRI diagnosis was analyzed. The relationship between p16 expression and MRI diagnostic materials was analyzed.

RESULTS

Compared with the results of the pathological examination, the total accuracy of MRI in the evaluation of T staging was 76.0% (57/75), and the excessive staging rate and insufficient staging rate were 8.0% (6/75) and 16.0% (12/75), respectively in the assessment of tumor T staging. IHC indicated that the positive expression rate of p16 in the tumor tissues was significantly lower than that in the tumor-adjacent tissues [34.67% (26/75) vs. 85.33% (64/75), p<0.05]. The chi-square test showed that the expression of p16 in the tumors was notably correlated with T staging, N staging, and myometrial invasion diagnosed with MRI.

CONCLUSIONS

P16 is significantly deficient in the rectal cancer tissues. MRI examination and identification are helpful for clinical diagnosis of rectal cancer staging. The combination of the two items may be helpful for the diagnosis of clinical rectal cancer staging and the establishment of reasonable treatment regimens.

Structure and formation of highly luminescent protein-stabilized gold clusters

Highly luminescent gold clusters simultaneously synthesized and stabilized by protein molecules represent a remarkable category of nanoscale materials with promising applications in bionanotechnology as sensors. Nevertheless, the atomic structure and luminescence mechanism of these gold clusters are still unknown after several years of developments. Herein, we report findings on the structure, luminescence and biomolecular self-assembly of gold clusters stabilized by the large globular protein, bovine serum albumin. We highlight the surprising identification of interlocked gold-thiolate rings as the main gold structural unit. Importantly, such gold clusters are in a rigidified state within the protein scaffold, offering an explanation for their highly luminescent character. Combined free-standing cluster synthesis (without protecting protein scaffold) with rigidifying and un-rigidifying experiments, were designed to further verify the luminescence mechanism and gold atomic structure within the protein. Finally, the biomolecular self-assembly process of the protein-stabilized gold clusters was elucidated by time-dependent X-ray absorption spectroscopy measurements and density functional theory calculations.

Individual and combined cytotoxicity assessment of zearalenone with ochratoxin A or α-zearalenol by full factorial design

The combined mycotoxins zearalenone (ZEA) with ochratoxin A (OTA) or α-zearalenol (α-ZOL) are frequently found together in milk. Toxicological data concerning the combined effects of these mycotoxins are sparse. In present study, individual and combined ZEA, OTA and α-ZOL caused cytotoxicity and oxidative damage, including reductions in intracellular superoxide dismutase and glutathione peroxidase activities and glutathione content, along with increases in malonaldehyde content on human Hep G2 cells after 48 h of exposure. Among individual mycotoxins, OTA had the greatest cytotoxic effect followed by α-ZOL. Compared with individual mycotoxins, combinations produced more serious negative effects, more importantly, ZEA + OTA was antagonistic for these effects, whereas ZEA + α-ZOL was antagonistic at low concentrations, but synergistic at high concentrations of ZEA, which were evaluated by 3 × 3 full factorial analysis and estimated marginal means plots. Our results also demonstrated a significant correlation between cytotoxicity and oxidative damage in response to these combinations.

Protective influence of rosiglitazone against testicular ischaemia-reperfusion injury in rats

Testicular torsion is a urology urgent disease which causes testicular injury and potential sterility. In this study, we explored the protective influence of rosiglitazone on testicular ischaemia-reperfusion damage. There were 28 male Sprague Dawley rats in total, which were assigned randomly to four groups. Group A was blank control one; group B was testicular injury one; group C was rosiglitazone one; group D was rosiglitazone antagonist one. The testicles were counter-rotated after 2 hr and then underwent orchiectomy 24 hr later. We found that testicular tissue structure of rats was seriously damaged in groups B and D. However, group C had better testicular architecture. Similar findings were also shown for lipid peroxidation by evaluating the MDA activity (p < .05). Unlike group B or group D, the levels of inflammation by evaluating the MPO activity, the levels of TNF-a, IL-1 and IL-6 and the expressions of ICAM-1 were prominently lower in group C (p < .05) as well. So our researches demonstrated that rosiglitazone significantly decreased the amount of responsive oxygen radical and regulated inflammatory responses. Rosiglitazone had a protective influence against testicular ischaemia-reperfusion injury in rats and possibly depended on its anti-inflammatory and antioxidant traits.

d-Glucose and amino acid deficiency inhibits casein synthesis through JAK2/STAT5 and AMPK/mTOR signaling pathways in mammary epithelial cells of dairy cows

Amino acids and energy deficiency lead to lower milk protein content in dairy cows. However, the known mechanisms involved in this process do not adequately explain the variability of milk protein concentration in the mammary gland. We hypothesized that a deficiency in d-glucose (d-Glc) or AA would inhibit casein synthesis by regulating signaling pathways in mammary epithelial cells. Cow mammary epithelial cells (CMEC) were subjected to combinations of 1 of 3 concentrations of d-Glc (0, 2.50, or 17.5 mM) and 1 of 3 concentrations of AA (0, 1.03, or 7.20 mM). The effect of each mixture on cell cycle stage was assessed by flow cytometry. The expression levels of β-casein and κ-casein (encoded by CSN2 and CSN3) were measured by quantitative real-time PCR and Western blotting. Phosphorylation of Janus kinase 2 (Jak2), signal transducer and activator of transcription 5a (Stat5a), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase 1 (S6K1), and eukaryotic factor 4E-binding protein 1 (4EBP1) were analyzed by Western blotting. The percentages of cells in the DNA postsynthetic (G2) and DNA synthesis (S) phases would decrease, with the level of d-Glc or AA declining individually, but no interaction was observed between the d-Glc and AA effects. The CSN2 and CSN3 mRNA and protein were downregulated when d-Glc or AA decreased individually from 17.5 to 2.50 mM or from 7.20 to 1.03 mM, but d-Glc deficiency had a greater effect according to the regression analysis. The phosphorylation ratio of Jak2 (Tyr^1007/1008), Stat5a (Tyr⁶⁹⁴), mTOR (Ser²⁴⁴⁸), S6K1 (Thr³⁸⁹), and 4EBP1 (Thr³⁷) was downregulated with the level of d-Glc or AA decline, whereas the phosphorylation ratio of AMPK (Thr^183/172) was upregulated. And the change of d-Glc level had a more marked effect than AA in regulating the activity of these signaling protein above according to the regression analysis. Thus, d-Glc or AA deficiency likely reduced casein transcription via inhibition of the Jak2/Stat5 pathway, and reduced translation via suppression of the mTOR pathway by activation of AMPK, but d-Glc deficiency had a more marked effect. These indicated that deficiency of AA, and especially Glc, suppressed proliferation of CMEC and casein gene and protein expression, associated with inhibition of JAK2/STAT5 and AMPK/mTOR signaling pathways.

Increased expression of STIM1/Orai1 in platelets of stroke patients predictive of poor outcomes

BACKGROUND AND PURPOSE

The platelet activation that is mediated by store-operated Ca²⁺ entry via stromal interaction molecule (STIM1) and Orai1 Ca²⁺ influx channels has been shown to play a key role in ischaemic stroke (IS). This study aimed to evaluate the impact of platelet STIM1/Orai1 protein expression on outcomes of IS.

METHODS

A total of 160 patients with acute non-cardioembolic IS, among whom 45 patients had small-vessel diseases and 115 patients had large-vessel diseases, were evaluated. Patients were divided into two groups according to their baseline platelet STIM1/Orai1 protein expression: high-expression group (HG) (n = 80) and low-expression group (LG) (n = 80). Univariate and multivariate regression models were used to assess the correlation between STIM1/Orai1 expression and clinical outcomes, which included stroke severity that was measured based on the National Institutes of Health Stroke Scale and Stroke Impact Scale (SIS) at baseline and during the 3-month follow-up.

RESULTS

There were no significant differences in age, sex and cardiovascular risk factors between patients in HG and LG. However, HG had very high levels of biomarkers such as glycosylated hemoglobin, C-reactive protein, homocysteine and high mobility group box-1 protein (all P < 0.05). Although the baseline stroke severity (National Institutes of Health Stroke Scale score) was not obviously higher in HG than in LG, patients showed a better recovery score (SIS score) in LG than in HG (90.75 ± 13.65 vs. 80.68 ± 7.09; P = 0.022). STIM1/Orai1 expression was an independent predictor of the 3-month stroke recovery (hazard ratio, 4.543; 95% confidence interval, 1.941-29.145; P = 0.029).

CONCLUSIONS

A high expression level of platelet Orai1/STIMI1 was associated with poor clinical outcome (mortality and recurrence) and functional recovery (SIS scores) during the 3-month follow-up. Thus, we propose that these proteins are strongly predictive of life quality in patients with IS.

Short communication: Microbiological quality of raw cow milk and its association with herd management practices in Northern China

Contamination of raw milk with bacterial pathogens is potentially hazardous to human health. The aim of this study was to evaluate the total bacteria count (TBC) and presence of pathogens in raw milk in Northern China along with the associated herd management practices. A total of 160 raw milk samples were collected from 80 dairy herds in Northern China. All raw milk samples were analyzed for TBC and pathogens by culturing. The results showed that the number of raw milk samples with TBC <2 × 10⁶ cfu/mL and <1 × 10⁵ cfu/mL was 146 (91.25%) and 70 (43.75%), respectively. A total of 84 (52.50%) raw milk samples were Staphylococcus aureus positive, 72 (45.00%) were Escherichia coli positive, 2 (1.25%) were Salmonella positive, 2 (1.25%) were Listeria monocytogenes positive, and 3 (1.88%) were Campylobacter positive. The prevalence of S. aureus was influenced by season, herd size, milking frequency, disinfection frequency, and use of a Dairy Herd Improvement program. The TBC was influenced by season and milk frequency. The correlation between TBC and prevalence of S. aureus or E. coli is significant. The effect size statistical analysis showed that season and herd (but not Dairy Herd Improvement, herd size, milking frequency, disinfection frequency, and area) were the most important factors affecting TBC in raw milk. In conclusion, the presence of bacteria in raw milk was associated with season and herd management practices, and further comprehensive study will be powerful for effectively characterizing various factors affecting milk microbial quality in bulk tanks in China.

The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses

Objectives

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP).

Methods

Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.

Results

Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs.

Conclusions

Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively.

Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231–244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1.

Performance of Redox Active and Chelatable Iron Assays to Determine Labile Iron Release From Intravenous Iron Formulations

Emerging data from global markets outside the United States, where many generic iron sucrose formulations are available, have revealed that non‐US generic intravenous (i.v.) iron formulations may have iron release profiles that differ from the reference listed drug (RLD). The first generic i.v. iron approved in the United States was sodium ferric gluconate complex in 2011. We evaluated chelatable and redox labile iron assay methods to measure the amount of labile iron released from i.v. iron formulations in biorelevant matrices in vitro. The majority of published labile iron assays evaluated were not suitable for use in vitro due to overwhelming interference by the presence of the i.v. iron products. However, an optimized high‐performance liquid chromatography (HPLC)‐based method performed well for use in vitro labile iron detection in a biorelevant matrix. Application of this method may enhance bioequivalence evaluation of generic i.v. iron formulations in the future.