Contributions of Lactobacillus plantarum PC170 administration on the recovery of gut microbiota after short-term ceftriaxone exposure in mice

This study aimed to determine the impact of Lactobacillus plantarum PC170 concurrent with antibiotic treatment and/or during the recovery phase after antibiotic treatment on the body weight, faecal bacterial composition, short-chain fatty acids (SCFAs) concentration, and splenic cytokine mRNA expression of mice. Orally administrated ceftriaxone quantitatively and significantly decreased body weight, faecal total bacteria, Akkermansia muciniphila, and Lactobacillus plantarum, and faecal SCFAs concentration. Ceftriaxone treatment also dramatically altered the faecal microbiota with an increased Chao1 index, decreased species diversities and Bacteroidetes, and more Firmicutes and Proteobacteria. After ceftriaxone intervention, these changes all gradually started to recover. However, faecal microbiota diversities were still totally different from control by significantly increased α- and β-diversities. Bacteroidetes all flourished and became dominant during the recovery process. However, mice treated with PC170 both in parallel with and after ceftriaxone treatment encouraged more Bacteroidetes, Verrucomicrobia, and Actinobacteria, and the diversity by which to make faecal microbiota was very much closer to control. Furthermore, the expression of splenic pro-inflammatory cytokine tumour necrosis factor-α mRNA in mice supplemented with PC170 during the recovery phase was significantly lower than natural recovery. These results indicated that antibiotics, such as ceftriaxone, even with short-term intervention, could dramatically damage the structure of gut microbiota and their abilities to produce SCFAs with loss of body weight. Although such damages could be partly recovered with the cessation of antibiotics, the implication of antibiotics to gut microbiota might remain even after antibiotic treatment. The selected strain PC170 might be a potential probiotic because of its contributions in helping the host animal to remodel or stabilise its gut microbiome and enhancing the anti-inflammatory response as protection from the side effects of antibiotic therapy when it was administered in parallel with and after antibiotic treatment.

MiR-127-3p targets KIF3B to inhibit the development of oral squamous cell carcinoma

OBJECTIVE

Recently, increased microRNAs have been shown to play an important role in the pathogenesis and progression of human cancers, including oral squamous cell carcinoma (OSCC). In this study, we focused on the function of microRNA-127-3p (miR-127-3p) associated with OSCC carcinogenesis.

PATIENTS AND METHODS

MiR-127-3p and KIF3B expressions were observed via quantitative Real-time polymerase chain reaction (qRT-PCR) or Western blot in OSCC. The functions of mR-127-3p and KIF3B were investigated through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and transwell assays. And luciferase reporter assay was performed to confirm the relationship between mR-127-3p and KIF3B.

RESULTS

First, down-regulation of miR-127-3p was identified in OSCC, which was associated with malignant clinicopathological features and poor prognosis in OSCC patients. Functionally, overexpression of miR-127-3p led to inhibition of cell proliferation and metastasis in OSCC. Further, KIF3B was confirmed to be a direct target of miR-127-3p. Moreover, upregulation of KIF3B was also observed in OSCC, which promoted tumorigenesis of OSCC. In particular, the upregulation of KIF3B partially attenuated the inhibitory effect of miR-127-3p on the development of OSCC.

CONCLUSIONS

MiR-127-3p targeted KIF3B to inhibit the development of OSCC through suppressing cell proliferation, migration and invasion.

Blood Group Antigen Shielding Facilitated by Selective Cell Surface Engineering

Production of red blood cells (RBCs) without immunogenicity of blood group antigens is of special interest in blood transfusion therapy in clinical chemistry. In this study, a selective cell surface engineering method was developed for the preparation of antigen-shielded RBCs based on molecular imprinting. Using an epitope imprinting method, biocompatible molecularly imprinted nanogels (MIgels) were prepared with a high affinity to the blood group antigens of RBCs. The antigen-shielded RBCs could avoid the agglutination caused by blood group mismatch, resulting in the antigen-shielded RBCs in efficiently substituting RBCs in case of a shortage of blood supply. Moreover, the antigen-shielded RBCs could maintain the normal physiological structure and functions of the original RBCs. We believe that the selective cell surface engineering presented in this work may offer significant benefits in specific cell protection for biomedical application.

Multiple-centre clinical evaluation of an ultrafast single-tube assay for SARS-CoV-2 RNA

OBJECTIVE

To evaluate the performance of an ultrafast single-tube nucleic acid isothermal amplification detection assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA using clinical samples from multiple centres.

METHODS

A reverse transcription recombinase-aided amplification (RT-RAA) assay for SARS-CoV-2 was conducted within 15 minutes at 39°C with portable instruments after addition of extracted RNA. The clinical performance of RT-RAA assay was evaluated using 947 clinical samples from five institutions in four regions of China; approved commercial fluorescence quantitative real-time PCR (qRT-PCR) kits were used for parallel detection. The sensitivity and specificity of RT-RAA were compared and analysed.

RESULTS

The RT-RAA test results of 926 samples were consistent with those of qRT-PCR (330 were positive, 596 negative); 21 results were inconsistent. The sensitivity and specificity of RT-RAA was 97.63% (330/338, 95% confidence interval (CI) 95.21 to 98.90) and 97.87% (596/609, 95% CI 96.28 to 98.81) respectively. The positive and negative predictive values were 96.21% (330/343, 95% CI 93.45 to 97.88) and 98.68% (596/604, 95% CI 97.30 to 99.38) respectively. The total coincidence rate was 97.78% (926/947, 95% CI 96.80 to 98.70), and the kappa was 0.952 (p < 0.05).

CONCLUSIONS

With comparable sensitivity and specificity to the commercial qRT-PCR kits, RT-RAA assay for SARS-CoV-2 exhibited the distinctive advantages of simplicity and rapidity in terms of operation and turnaround time.

[Influential factors related to the long-term effect of periodontal-orthodontic treatment in patients with aggressive periodontitis and malocclusion]

Objective: To investigate the influential factors related to the long-term effect of periodontal-orthodontic treatment in patients with aggressive periodontitis (AgP). Methods: A retrospective analysis was conducted in 25 AgP patients, who have received periodontal-orthodontic treatment in Peking University School and Hospital of Stomatology. Changes in the ratio of the residual alveolar bone height (RBH) was measured at three time points: baseline (T0), post orthodontic treatment (T1), and the last re-visit 3 years after orthodontic treatment (T2). Root abnormity was evaluated by observing periapical radiographs, and its relationship with alveolar bone loss after orthodontic treatment was analyzed. A multi-level analysis on factors related to the clinical outcome (alveolar bone height change) was performed. Results: Totally 693 teeth of 25 patients at T0 and T1 and 368 teeth of 14 patients at T2 were investigated. During the periodontal-orthodontic treatment, the RBH was mainly influenced by root abnormity (estimation value -2.392), tooth position (estimation value for upper teeth vs. lower teeth 3.139, and anterior teeth vs. posterior teeth -3.469) and the baseline RBH at T0 (estimation value -0.391) (P<0.05). Teeth with root abnormity, teeth in mandibular and anterior area, and teeth with higher RBH showed less change in T1-T0 RBH values. In the long-term follow-up, RBH was mainly influenced by tooth position (estimation value for upper teeth vs. lower teeth 3.735, and anterior teeth vs. posterior teeth -5.318), the baseline RBH and probing depth (PD) at T0. Teeth in mandibular and anterior area, teeth with higher RBH (estimation value -0.498) and PD (estimation value -1.594) (P<0.05) showed less change in T0-T2 RBH values. Conclusions: During orthodontic treatment, teeth with abnormal root, lower teeth, anterior teeth, and teeth with high RBH were unfavorable factors for bone gain. In the long-term observation, lower teeth, anterior teeth, teeth with high RBH and PD at first visit were unfavorable factors for bone gain.

Liquid-phase mega-electron-volt ultrafast electron diffraction

The conversion of light into usable chemical and mechanical energy is pivotal to several biological and chemical processes, many of which occur in solution. To understand the structure-function relationships mediating these processes, a technique with high spatial and temporal resolutions is required. Here, we report on the design and commissioning of a liquid-phase mega-electron-volt (MeV) ultrafast electron diffraction instrument for the study of structural dynamics in solution. Limitations posed by the shallow penetration depth of electrons and the resulting information loss due to multiple scattering and the technical challenge of delivering liquids to vacuum were overcome through the use of MeV electrons and a gas-accelerated thin liquid sheet jet. To demonstrate the capabilities of this instrument, the structure of water and its network were resolved up to the 3 rd hydration shell with a spatial resolution of 0.6 Å; preliminary time-resolved experiments demonstrated a temporal resolution of 200 fs.

Integrated analysis of different mRNA and miRNA profiles in human hypopharyngeal squamous cell carcinoma sensitive and resistant to chemotherapy

The purpose of this study was to identify potential miRNAs and mRNAs involved in chemotherapy insensitivity in hypopharyngeal squamous cell carcinoma (HSCC) and to explore the underlying mechanisms involved to provide diagnostic markers and therapeutic targets for HSCC. We used microarrays to identify differences in both the mRNA and miRNA expression profiles between a group (twelve patients) sensitive to chemotherapy and a resistant group (nine patients). We then employed bioinformatics tools to examine the functions and pathways involved. The genes and miRNAs most related to chemotherapy sensitivity in HSCC were screened. Finally, a miRNA-mRNA-phenotype network was constructed with an integrated analysis based on the identified miRNAs and mRNAs. Nine differentially expressed miRNAs and one hundred differentially expressed mRNAs were identified, and the functions of these genes and miRNAs were predicted. Bioinformatics analysis revealed a regulatory network consisting of eight genes and two miRNAs that influenced HSCC chemosensitivity. According to our analysis, CCL4L1 may be a potential molecular marker for HSCC chemotherapy, and excess CCL4L1 leads to the upregulation of PRAME and the downregulation of miR-375, thus decreasing HSPB8 expression and promoting chemotherapy sensitivity. Our work provides reliable data for further studies investigating the mechanism of HSCC chemotherapy sensitivity.

Femtosecond Compression Dynamics and Timing Jitter Suppression in a THz-driven Electron Bunch Compressor

We present the first demonstration of THz driven bunch compression and timing stabilization of a relativistic electron beam. Quasi-single-cycle strong field THz radiation is used in a shorted parallel-plate structure to compress a few-fC beam with 2.5 MeV kinetic energy by a factor of 2.7, producing a 39 fs rms bunch length and a reduction in timing jitter by more than a factor of 2 to 31 fs rms. This THz driven technique offers a significant improvement to beam performance for applications like ultrafast electron diffraction, providing a critical step towards unprecedented timing resolution in ultrafast sciences, and other accelerator applications using femtosecond-scale electron beams.

Artificial Cytochrome c Mimics: Graphene Oxide-Fe(III) Complex-Coated Molecularly Imprinted Colloidosomes for Selective Photoreduction of Highly Toxic Pollutants

Our previous works showed that the molecularly imprinted TiO₂ photocatalyst has been one of the most efficient materials for selective photooxidation of highly toxic organic pollutants (HTOPs) from complicated wastewater. However, some highly toxic pollutants (e.g., heavy metals) are very stable under the oxidizing environment. Therefore, the design of enzyme-like catalysts to selectively reduce highly toxic pollutants is extremely needed. In this work, inspired by the bioreduction ability of cytochrome c (cyt c, a heme containing metalloprotein), we presented a simple and efficient way to generate an artificial cyt c mimic (ACM) using graphene oxide (GO)-Fe(III) complex-coated molecularly imprinted colloidosomes. Prior to loading of Fe(III) centers to GO for constructing ACMs, GO-coated molecularly imprinted colloidosomes were synthesized via Pickering emulsion polymerization. Similar to a nature cyt c, the ACM contained both the molecular recognition element (molecularly imprinted cavity) and the non-heme electron sink (GO-Fe(III) complex), which resulted in the ACMs having good selectivity toward the enzyme-like reduction of the highly toxic target Cr(VI). Moreover, by using HepG2 cells as model cells, the Cr(VI) solution after treating by ACMs was proved to be safe and nontoxic. To confirm that the present method was universal for constructing ACMs, various GO-Fe(III) complex-coated molecularly imprinted colloidosomes, which could selectively photoreduce other highly toxic inorganic ions and organic pollutants, were also investigated. The ACMs described herein will act as a vector that encourages the design of more functional non-heme enzymes in sensing, environmental separation, clinical diagnose, and delivery of therapeutic agents.

TaqMan real-time PCR for detecting bovine viral diarrhea virus

The present study was aimed to establish a novel TaqMan real-time PCR (RTm-PCR) for detecting and typing bovine viral diarrhea virus (BVDV), and also to develop a diagnostic protocol which simplifies sample collection and processing. Universal primers and TaqMan-MGB probes were designed from the known sequences of conserved 5' - and 3'-untranslated regions (5'UTR, 3'UTR) of the NADL strain of BVDV. Prior to optimizing the assay, cDNAs were transcribed in vitro to make standard curves. The sensitivity, specificity and stability (reproducibility) were evaluated. The RTm-PCR was tested on the 312 feces specimens collected from persistently infected (PI) calves. The results showed the optimum conditions for RTm-PCR were 17.0 μmol/L primer, 7.5 μmol/L probe and 51.4°C annealing temperature. The established TaqMan RTm-PCR assay could specially detect BVDV without detecting any other viruses. Its detection limit was 1.55×100 copies/μL for viral RNA. It was 10000-fold higher than conventional PCR with excellent specificity and reproducibility. 312 samples were tested using this method and universal PCR from six dairy farms, respectively. Positive detections were found in 49 and 44 feces samples, respectively. The occurrence rate was 89.80%. In conclusion, the established TaqMan RTm-PCR could rapidly detect BVDV and effectively identify PI cattle. The detection limit of RTm-PCR was 1.55 copies/μL. It will be beneficial for enhancing diagnosis and therapy efficacy and reduce losses in cattle farms.

Prospective study of perceived dietary salt intake and the risk of non-alcoholic fatty liver disease

BACKGROUND

A high sodium intake is associated with obesity and metabolic syndrome. However, little is known regarding whether greater salt intake is a potential risk factor for non-alcoholic fatty liver disease (NAFLD). We thus prospectively investigated whether individuals with higher perceived dietary salt intake had a higher risk of developing NAFLD.

METHODS

The present study included 35 023 participants (22 629 men and 12 394 women) from the Kailuan study who were free of NAFLD at baseline (2006) and who did not drink alcohol at baseline and during follow-up (2006-2014; follow-rate 95.2%). NAFLD was defined as a participant who had been diagnosed with fatty liver at least twice by ultrasound tests conducted every 2 years during follow-up. Dietary salt intake was determined by a self-report question and was classified into three categories: low (<6 g day^-1 ), medium (6-9 g day^-1 ) or high (≥10 g day^-1 ). Cox proportional models were used to estimate the risk of NAFLD, adjusting for potential confounders, such as age, sex, education, physical activity, smoking, income, occupation, marriage, body mass index, waist circumference and blood pressure, as well as serum concentrations of glutamic-pyruvic transaminase, glucose, total cholesterol and triglyceride.

RESULTS

During 8 years of follow-up, we identified 5102 incident NAFLD cases. After adjusting for potential confounders, the hazard ratio (95% conference interval) for NAFLD was 1.12 (1.00, 1.26) for medium salt intake and 1.19 (1.02,1.39) for high salt consumption (P trend = 0.03) relative to the low salt consumption group.

CONCLUSIONS

A perceived high salt intake was associated with a higher future risk of NAFLD.

Methionine and arginine supplementation alter inflammatory and oxidative stress responses during lipopolysaccharide challenge in bovine mammary epithelial cells in vitro

Mastitis, inflammation of the udder, is one of the most common diseases hampering milk yield of dairy cows. Methionine (Met) and arginine (Arg) are key nutrients with potential to regulate inflammation and oxidative stress. The aim of this study was to evaluate the effect of increased supply of Met and Arg on mRNA and protein abundance associated with innate immune response and redox balance during lipopolysaccharide (LPS) stimulation in primary bovine mammary epithelial cells (BMEC). Primary BMEC (n = 4 replicates per treatment) were pre-incubated for 12 h in media with the following amino acid combinations: ideal profile of amino acids (control; Con), increased Met supply (incMet), increased Arg supply (incArg), and increased supply of Met and Arg (incMetArg). Subsequently, cells were challenged with or without LPS (1 µg/mL) and incubated for 6 h. Data were analyzed as a 2 × 2 × 2 factorial using the MIXED procedure of SAS 9.4 (SAS Institute Inc., Cary, NC). The downregulation of SLC36A1 and SLC7A1 mRNA abundance induced by LPS was attenuated in the incArg cultures. Although challenge with LPS led to lower abundance of proteins related to the antioxidant response (NFE2L2, NQO1, GPX1), lower levels of ATG7, and lower mRNA abundance of GPX3, we found little effect in cultures with incMet or incArg. Cultures with incMet, incArg, or incMetArg led to attenuation of the upregulation of SOD2 and NOS2 induced by LPS. Abundance of phosphorylated p65 (RELA) was greater after LPS stimulation, but the response was attenuated in cultures with incMet. The greater ratio of pRELA to total RELA in responses to LPS was also attenuated in cultures with incMetArg. The greater mRNA abundance of the proinflammatory cytokine IL1B induced by LPS was attenuated in cultures with incMet, and the same trend induced by LPS on CXCL2 was also alleviated in cultures with incArg. Overall, the data suggest that greater supply of Met and Arg alleviated the proinflammatory responses triggered by LPS through controlling the abundance of proinflammatory cytokines and chemokines and activity of NF-κB. Little benefit on oxidative stress induced by LPS challenge in BMEC was detected with greater supply of Met and Arg.

Maternal Heavy Metal Exposure, Thyroid Hormones, and Birth Outcomes: A Prospective Cohort Study

CONTEXT

Maternal thyroid hormones during pregnancy play a critical role in fetal development. However, whether maternal heavy metal exposure affects their thyroid hormones and the effects on fetal growth are still unclear.

OBJECTIVE

To explore the effect of heavy metal exposure on maternal thyroid hormones and the potential mediation role of thyroid hormones on birth outcomes.

METHODS

Concentrations of heavy metals in urine samples and thyroid hormones in blood samples of 675 pregnant women were measured during early pregnancy in a cohort study conducted in China. Multivariable linear regressions were applied to explore the associations of maternal urinary heavy metal levels with both maternal thyroid hormones and birth outcomes. Mediation analyses were performed to assess the mediation role of thyroid hormones in these associations.

RESULTS

Maternal urinary vanadium (V) exhibited an inverse association with free T3 (FT3) and FT3/free T4 (FT4) ratio levels. Urinary arsenic (As) and lead (Pb) had inverse relationships with FT3. We also observed the positive associations of maternal FT3 and FT3/FT4 ratio with birthweight. The mediation analyses suggested that 5.33% to 30.57% of the associations among V, As, and Pb levels and birth size might be mediated by maternal FT3 or FT3/FT4 ratio.

CONCLUSIONS

We have shown that maternal exposures to V, As, and Pb at early pregnancy were associated with decreased maternal FT3 or FT3/FT4 ratio, which might contribute to reduced birthweight. Mediation analyses indicated that maternal thyroid hormone was a possible mediator of the association between urinary heavy metals and birth size.