HMGB1 prefers to interact with structural RNAs and regulates rRNA methylation modification and translation in HeLa cells.

BACKGROUND: High-mobility group B1 (HMGB1) is both a DNA binding nuclear factor modulating transcription and a crucial cytokine that mediates the response to both infectious and noninfectious inflammation such as autoimmunity, cancer, trauma, and ischemia reperfusion injury. HMGB1 has been proposed to control ribosome biogenesis, similar as the other members of a class of HMGB proteins. RESULTS: Here, we report that HMGB1 selectively promotes transcription of genes involved in the regulation of transcription, osteoclast differentiation and apoptotic process. Improved RNA immunoprecipitation by UV cross-linking and deep sequencing (iRIP-seq) experiment revealed that HMGB1 selectively bound to mRNAs functioning not only in signal transduction and gene expression, but also in axon guidance, focal adhesion, and extracellular matrix organization. Importantly, HMGB1-bound reads were strongly enriched in specific structured RNAs, including the domain II of 28S rRNA, H/ACA box snoRNAs including snoRNA63 and scaRNAs. RTL-P experiment showed that overexpression of HMGB1 led to a decreased methylation modification of 28S rRNA at position Am2388, Cm2409, and Gm2411. We further showed that HMGB1 overexpression increased ribosome RNA expression levels and enhanced protein synthesis. CONCLUSION: Taken together, our results support a model in which HMGB1 binds to multiple RNA species in human cancer cells, which could at least partially contribute to HMGB1-modulated rRNA modification, protein synthesis function of ribosomes, and differential gene expression including rRNA genes. These findings provide additional mechanistic clues to HMGB1 functions in cancers and cell differentiation.

Case Report: Telitacicept in treating a patient with NF155+ autoimmune nodopathy: a successful attempt to manage recurrent elevated sero-anti-NF155 antibodies.

This report presents a case of a neurofascin-155 (NF155)+ autoimmune nodopathy (AN) patient who exhibited resistance to conventional treatments but responded positively to telitacicept therapy. Telitacicept, a dual inhibitor of B lymphocyte stimulator (BLyS) and A proliferation-inducing ligand (APRIL), suppressed the development and survival of plasma cells and mature B cells. The patient's unique clinical features were consistent with NF155+ AN, showing limited response to standard treatments like rituximab and a recurrent significant increase in anti-NF155 antibody titers. Administering telitacicept (160mg, ih) led to an improvement in clinical symptoms, inflammatory neuropathy cause and treatment (INCAT) scale and inflammatory Rasch-built overall disability scale (I-RODS), and stabilized anti-NF155 antibody levels without a rebound. This case demonstrates telitacicept as a potential novel therapy for NF155+ AN, particularly when conventional treatments fail. Further investigation into its safety, efficacy, dosage, and treatment cycle in NF155+ AN is warranted.

Erythrocytes: Member of the immune system that should not be ignored.

Erythrocytes are the most abundant type of cells in the blood and have a relatively simple structure when mature; they have a long life-span in the circulatory system. The primary function of erythrocytes is as oxygen carriers; however, they also play an important role in the immune system. Erythrocytes recognize and adhere to antigens and promote phagocytosis. The abnormal morphology and function of erythrocytes are also involved in the pathological processes of some diseases. Owing to the large number and immune properties of erythrocytes, their immune functions should not be ignored. Currently, research on immunity is focused on immune cells other than erythrocytes. However, research on the immune function of erythrocytes and the development of erythrocyte-mediated applications is of great significance. Therefore, we aimed to review the relevant literature and summarize the immune functions of erythrocytes.

Prognostic significance of the preoperative alkaline phosphatase­to­albumin ratio in patients with hepatocellular carcinoma after hepatic resection.

This study aimed to investigate the prognostic value of the preoperative alkaline phosphatase-to-albumin ratio (APAR) in patients with hepatocellular carcinoma (HCC) who underwent radical hepatectomy. The clinicopathological data from 330 patients was retrospectively analyzed. Receiver operating characteristic curves of APAR for diagnostic tumor recurrence were plotted with a cut-off value of 1.74. A high preoperative APAR value was significantly associated with hepatitis B surface antigen level, tumor diameter, and tumor-node-metastasis stage. The disease-free survival (DFS) and overall survival (OS) of patients with a high preoperative APAR were shorter than those with a low APAR. The independent risk factors for DFS were an APAR ≥1.74, and macrovascular invasion or tumor thrombus. The independent risk factors for OS were an APAR ≥1.74, existing clinical symptoms, α-fetoprotein level ≥20 ng/ml, macrovascular invasion or tumor thrombus, and family history of cancer. In conclusion, a preoperative APAR (≥1.74) is an independent risk factor influencing the poor prognosis of patients with HCC after curative hepatectomy, and patients with such a result should be closely monitored.

Validation of CORE-MD PMS Support Tool: A Novel Strategy for Aggregating Information from Notices of Failures to Support Medical Devices' Post-Market Surveillance.

INTRODUCTION: The EU Medical Device Regulation 2017/745 defines new rules for the certification and post-market surveillance of medical devices (MD), including an additional review by Expert Panels of clinical evaluation data for high-risk MD if reports and alerts suggest possibly associated increased risks. Within the EU-funded CORE-MD project, our aim was to develop a tool to support such process in which web-accessible safety notices (SN) are automatically retrieved and aggregated based on their specific MD categories and the European Medical Device Nomenclature (EMDN) classification by applying an Entity Resolution (ER) approach to enrich data integrating different sources. The performance of such approach was tested through a pilot study on the Italian data. METHODS: Information relevant to 7622 SN from 2009 to 2021 was retrieved from the Italian Ministry of Health website by Web scraping. For incomplete EMDN data (68%), the MD best match was searched within a list of about 1.5 M MD on the Italian market, using Natural Language Processing techniques and pairwise ER. The performance of this approach was tested on the 2440 SN (32%) already provided with the EMDN code as reference standard. RESULTS: The implemented ER method was able to correctly assign the correct manufacturer to the MD in each SN in 99% of the cases. Moreover, the correct EMDN code at level 1 was assigned in 2382 SN (97.62%), at level 2 in 2366 SN (96.97%) and at level 3 in 2329 SN (95.45%). CONCLUSION: The proposed approach was able to cope with the incompleteness of the publicly available data in the SN. In this way, grouping of SN relevant to a specific MD category/group/type could be used as possible sentinel for increased rates in reported serious incidents in high-risk MD.

Molecular Mechanism of Chloramphenicol and Thiamphenicol Resistance Mediated by a Novel Oxidase, CmO, in Sphingomonadaceae.

Antibiotic resistance mediated by bacterial enzyme inactivation plays a crucial role in the degradation of antibiotics in the environment. Chloramphenicol (CAP) resistance by enzymatic inactivation comprises nitro reduction, amide bond hydrolysis, and acetylation modification. However, the molecular mechanism of enzymatic oxidation of CAP remains unknown. Here, a novel oxidase gene, cmO, was identified and confirmed biochemically. The encoded CmO oxidase could catalyze the oxidation at the C-1' and C-3' positions of CAP and thiamphenicol (TAP) in Sphingobium sp. strain CAP-1. CmO is highly conserved in members of the family Sphingomonadaceae and shares the highest amino acid similarity of 41.05% with the biochemically identified glucose methanol choline (GMC) oxidoreductases. Molecular docking and site-directed mutagenesis analyses demonstrated that CAP was anchored inside the protein pocket of CmO with the hydrogen bonding of key residues glycine (G) 99, asparagine (N) 518, methionine (M) 474, and tyrosine (Y) 380. CAP sensitivity tests demonstrated that the acetyltransferase and CmO could enable a higher level of resistance to CAP than the amide bond-hydrolyzing esterase and nitroreductase. This study provides a better theoretical basis and a novel diagnostic gene for understanding and assessing the fate and resistance risk of CAP and TAP in the environment. IMPORTANCE Rising levels of antibiotic resistance are undermining ecological and human health as a result of the indiscriminate usage of antibiotics. Various resistance mechanisms have been characterized-for example, genes encoding proteins that degrade antibiotics-and yet, this requires further exploration. In this study, we report a novel gene encoding an oxidase involved in the inactivation of typical amphenicol antibiotics (chloramphenicol and thiamphenicol), and the molecular mechanism is elucidated. The findings provide novel data with which to understand the capabilities of bacteria to tackle antibiotic stress, as well as the complex function of enzymes in the contexts of antibiotic resistance development and antibiotic removal. The reported gene can be further employed as an indicator to monitor amphenicol's fate in the environment, thus benefiting risk assessment in this era of antibiotic resistance.

The distribution and speciation of dissolved Cd and Pb in the Bohai Sea and Yellow Sea, China.

The speciation of dissolved trace metals is important due to its closely linkage with toxicity and bioavailability in seawater. We investigate the speciation of dissolved Pb (DPb) and Cd (DCd), and their spatial distributions in the Yellow Sea and Bohai Sea, China. The results showed that the organic complexation of DPb and DCd accounted for 35 ± 14 % and 75 ± 10 % of their dissolved concentrations, respectively. The measured free ion activity of Cd ({Cd2 +}) and organic ligand concentration of Cd ([LCd]) were highest near the Yellow River mouth, where the free ion activity of Pb ({Pb2+}) were also found to be the highest. In this study, both {Pb2+} and {Cd2+} did not exceed the toxicity threshold, and they were identified not toxic in the waters of the Yellow Sea and Bohai Seas, but biological accumulation effects potentially exist.

Early hemodynamics after tibial transverse transport in patients with nonarterial stenosis and arterial stenosis diabetic foot.

BACKGROUND: The diagnosis of peripheral arteriopathy in the diabetic foot is complicated by diabetes and its advanced complications. It has been found that diabetic foot can be categorized into arterial stenosis and non-arterial stenosis, both of which have significant differences in hemodynamic characteristics. AIM: To evaluate the early hemodynamic changes in diabetic foot patients with nonarterial stenosis and arterial stenosis treated by tibial transverse transport (TTT) using high-frequency color Doppler ultrasonography (HFCDU) and a laser Doppler flowmeter. METHODS: Twenty-five patients with Wagner grades 3-5 diabetic foot ulcers were treated with TTT, and the wound healing time and rate were recorded. Patients were grouped according to the results of preoperative lower-extremity ultrasonography. Cases with ≥ 50% stenosis in any of the femoral, popliteal, posterior tibial, anterior tibial, and peroneal arteries of the affected limb were classified as the arterial stenosis group (n = 16); otherwise, they were classified as the nonarterial stenosis group (n = 9). Before and one month after surgery, HFCDU was used to evaluate the degree of lower limb artery lesions and hemodynamic changes in patients. The degree of femoral-popliteal atherosclerotic stenosis, the degree of vascular stenosis and occlusion of the lower-knee outflow tract, and the degree of medial arterial calcification were scored; the three scores were added together to obtain the total score of lower extremity arteriopathy. PeriScanPIM3, a laser Doppler flowmeter system, was used to detect alterations in plantar microcirculation before and 1 mo after surgery. Wound healing and hemodynamic indices were compared between the two groups. RESULTS: The wound healing time of the diabetic foot was significantly shorter in the nonarterial stenosis group than in the arterial stenosis group (47.8 ± 13 vs 85.8 ± 26, P < 0.05), and the wound healing rate of both groups was 100%. The preoperative total lower extremity arteriopathy scores were lower in the nonarterial stenosis group than those in the arterial stenosis group (18.89 ± 8.87 vs 24.63 ± 3.52, P < 0.05). The nonarterial stenosis group showed higher preoperative popliteal artery (POA) blood flow than the arterial stenosis group (204.89 ± 80.76 cc/min vs 76.75 ± 48.49 cc/min, P < 0.05). Compared with the baseline (before surgery), the postoperative POA blood flow of the affected limb in the nonarterial stenosis group decreased one month after surgery (134.11 ± 47.84 cc/min vs 204.89 ± 80.76 cc/min, P < 0.05), while that in the arterial stenosis group increased (98.44 ± 30.73 cc/min vs 61.69 ± 21.70 cc/min, P < 0.05). Although the POA blood flow in the arterial stenosis group was obviously improved one month after surgery, it was still lower than that in the nonarterial stenosis group (98.44 ± 30.73 cc/min vs 134.11 ± 47.84 cc/min, P < 0.05). The nonarterial stenosis group had higher preoperative plantar microcirculation than the arterial stenosis group (56.1 ± 9.2 vs 33.2 ± 7.5, P < 0.05); compared with the baseline, the plantar microcirculation in the arterial stenosis group was significantly improved one month after surgery (51.9 ± 7.2, P < 0.05), while that in the nonarterial stenosis group was reduced (35.9 ± 7.2, P < 0.05). CONCLUSION: Based on preoperative HFCDU findings, diabetic foot patients can be divided into two categories: Those with nonarterial stenosis and those with arterial stenosis, with obvious differences in hemodynamic changes in the early postoperative period between them. In the early stage after TTT, the blood flow volume and velocity and the plantar microcirculation perfusion of the affected limb of the diabetic foot with nonarterial stenosis decreased compared with the baseline, while those of the diabetic foot with arterial stenosis improved significantly compared with the baseline, although both had smoothly healed diabetic foot ulcers.

CircDOCK1 Regulates miR-186/DNMT3A to Promote Osteosarcoma Progression.

BACKGROUND: Circular RNAs (circRNAs), as a class of endogenous RNAs, are implicated in osteosarcoma (OS) progression. However, the functional properties of circDOCK1 in OS have been largely unexplored. The present study demonstrated the regulatory mechanism of circDOCK1 in OS. METHODS: QRT-PCR and Western blots were used to determine the abundances of circDOCK1, miR-186, and DNMT3A. Cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), colony formation, Transwell, and wound healing assays were used to examine cellular multiplication, motility, and invasion. Luciferase reporter analysis, RNA immunoprecipitation (RIP), and pull-down assays were used to verify target relationships. Xenograft models were used to analyze in vivo function. RESULTS: OS tissues and cells showed high levels of circDOCK1. By knocking down circDOCK1, cellular multiplication, motility, and invasion were suppressed. Furthermore, silencing circDOCK1 suppressed the growth of tumor xenografts. According to mechanistic studies, miR-186 targets DNA methyltransferases 3A (DNMT3A) directly and acts as a circDOCK1 target. Furthermore, circDOCK1 upregulated DNMT3A expression through sponging miR-186 to regulate the progression of OS. CONCLUSIONS: CircDOCK1 promotes OS progression by interacting with miR-186/DNMT3ADNMT3A, representing a novel therapeutic approach.

Intestinal Ecology Changes in Diarrheic Père David's Deer Revealed by Gut Microbiota and Fecal Metabolites Analysis.

Diarrhea is one of the most common diseases affecting the health of Père David's deer (Elaphurus davidianus). It is believed that an imbalanced intestinal ecology contributes to the etiology of the condition. However, little is known about how the intestinal ecology changes in these diarrheic animals. In this study, 16S rRNA gene sequencing and ultra-high performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS) were used to investigate the gut microbiota and fecal metabolites in five Père David's deer with diarrhea. The results showed that when compared with healthy individuals, considerable changes in the gut microbiome were observed in diarrheic animals, including a significant reduction in microbial diversity and gut microbiota composition alterations. Furthermore, the profiles of numerous fecal metabolites were altered in diarrheic individuals, showing large-scale metabolite dysregulation. Among metabolites, acylcarnitines, lysophosphatidylcholine, bile acids, and oxidized lipids were elevated significantly. Constantly, several metabolic pathways were significantly altered. Interestingly, predicted metabolic pathways based on 16S rRNA gene sequence and differential metabolite analysis showed that lipid metabolism, cofactor, and vitamin metabolism were altered in sick animals, indicating microbiota-host crosstalk in these deer. When combined, the results provide the first comprehensive description of an intestinal microbiome and metabolic imbalance in diarrheic Père David's deer, which advances our understanding and potential future treatment of diarrheic animals.

Long non-coding RNA NR2F2-AS1 regulates human osteosarcoma growth and metastasis through miR-425-5p-mediated HMGB2.

BACKGROUND: Multiple studies have revealed that long non-coding RNA (lncRNA) NR2F2-AS1 plays a role in affecting cancer cell proliferation and metastasis. Here, both in vitro and in vivo experiments were performed for investigating the function and mechanism of NR2F2-AS1 in human osteosarcoma (OS). METHODS: The NR2F2-AS1 level in human OS tissues and adjacent non-tumor tissues was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The NR2F2-AS1 overexpression model was constructed in OS cells, then cell proliferation, invasion, and apoptosis were monitored. The OS xenograft model was established in nude mice using NR2F2-AS1-overexpressed OS cells. The downstream target genes of NR2F2-AS1 were predicted. qRT-PCR and Western blot were implemented to validate the profiles of miR-425-5p and HMGB2. The targeting link between NR2F2-AS1 and miR-425-5p, miR-425-5p and HMGB2 was further probed by dual-luciferase reporter experiment. RESULTS: In comparison to adjacent non-tumor tissues, OS tissues showed upregulated NR2F2-AS1 expression. Higher NR2F2-AS1 level was predominantly correlated with worse clinical stages. In vivo and in vitro tests corroborated that NR2F2-AS1 overexpression spurred OS cell proliferation, growth, invasion, and choked apoptosis. Mechanistically, NR2F2-AS1 hampered miR-425-5p expression as its competitive endogenous RNA (ceRNA). Thus, NR2F2-AS1 facilitated the HMGB2 expression. However, miR-425-5p inhibited HMGB2 expression by targeting the latter. CONCLUSION: NR2F2-AS1 expedited the evolution of OS by elevating HMGB2 levels through sponging miR-425-5p. The NR2F2-AS1/miR-425-5p/HMGB2 regulatory axis is a promising target in treating human OS.

Remote Eradication of Bacteria on Orthopedic Implants via Delayed Delivery of Polycaprolactone Stabilized Polyvinylpyrrolidone Iodine.

Bacteria-associated late infection of the orthopedic devices would further lead to the failure of the implantation. However, present ordinary antimicrobial strategies usually deal with early infection but fail to combat the late infection of the implants due to the burst release of the antibiotics. Thus, to fabricate long-term antimicrobial (early antibacterial, late antibacterial) orthopedic implants is essential to address this issue. Herein, we developed a sophisticated MAO-I2-PCLx coating system incorporating an underlying iodine layer and an upper layer of polycaprolactone (PCL)-controlled coating, which could effectively eradicate the late bacterial infection throughout the implantation. Firstly, micro-arc oxidation was used to form a microarray tubular structure on the surface of the implants, laying the foundation for iodine loading and PCL bonding. Secondly, electrophoresis was applied to load iodine in the tubular structure as an efficient bactericidal agent. Finally, the surface-bonded PCL coating acts as a controller to regulate the release of iodine. The hybrid coatings displayed great stability and control release capacity. Excellent antibacterial ability was validated at 30 days post-implantation via in vitro experiments and in vivo rat osteomyelitis model. Expectedly, it can become a promising bench-to-bedside strategy for current infection challenges in the orthopedic field.

Top 100 most cited articles on anterior cervical discectomy and fusion.

Study Design: Bibliometric analysis. Objective: Anterior cervical discectomy and fusion (ACDF) is a typical surgical method in spine surgery and has progressed significantly in the last several decades. The purpose of this study is to determine how the 100 most-cited original articles on ACDF have been the most influential in this field by identifying and analyzing them. Methods: The articles on ACDF were identified by searching the Thomson ISI Web of Science database on 30 May 2022. The 100 most-cited articles were selected according to specific criteria. The data extracted from the articles included title, publication date, total citations, journal name, first author, institutions, and keywords. Results: The total number of citations was 13,181, with a mean number of 131.81 ± 100.18. The publication dates ranged from 1994 to 2018. Most of these articles originated in the United States (68%) and were published in the 2000s (32%) and 2010s (48%). Spine published most of the articles (30%), followed by the Journal of Neurosurgery-Spine (16%), Spine Journal (14%), and European Spine Journal (13%). The most prolific author was Dr. Todd J Albert (n = 7), with 1,312 citations. The Texas Back Institute was the most productive institution (n = 10). The keywords ACDF, cervical spine, cervical spine, and fusion showed the highest degree of centrality. Conclusion: One hundred top-cited articles on ACDF were identified and analyzed in this study. We demonstrate that ACDF is a growing and popular area of research, with the focus of research varying through timeline trends. This will provide a comprehensive and detailed basis for spine surgeons to make clinical decisions and assimilate the research focus of cervical spine surgery.

The Novel Amidase PcnH Initiates the Degradation of Phenazine-1-Carboxamide in Sphingomonas histidinilytica DS-9.

Phenazines are an important class of secondary metabolites and are primarily named for their heterocyclic phenazine cores, including phenazine-1-carboxylic acid (PCA) and its derivatives, such as phenazine-1-carboxamide (PCN) and pyocyanin (PYO). Although several genes involved in the degradation of PCA and PYO have been reported so far, the genetic foundations of PCN degradation remain unknown. In this study, a PCN-degrading bacterial strain, Sphingomonas histidinilytica DS-9, was isolated. The gene pcnH, encoding a novel amidase responsible for the initial step of PCN degradation, was cloned by genome comparison and subsequent experimental validation. PcnH catalyzed the hydrolysis of the amide bond of PCN to produce PCA, which shared low identity (only 26 to 33%) with reported amidases. The Km and kcat values of PcnH for PCN were 33.22 ± 5.70 µM and 18.71 ± 0.52 s-1, respectively. PcnH has an Asp-Lys-Cys motif, which is conserved among amidases of the isochorismate hydrolase-like (IHL) superfamily. The replacement of Asp37, Lys128, and Cys163 with alanine in PcnH led to the complete loss of enzymatic activity. Furthermore, the genes pcaA1A2A3A4 and pcnD were found to encode PCA 1,2-dioxygenase and 1,2-dihydroxyphenazine (2OHPC) dioxygenase, which were responsible for the subsequent degradation steps of PCN. The PCN-degradative genes were highly conserved in some bacteria of the genus Sphingomonas, with slight variations in the sequence identities. IMPORTANCE Phenazines have been widely acknowledged as a natural antibiotic for more than 150 years, but their degradation mechanisms are still not completely elucidated. Compared with the studies on the degradation mechanism of PCA and PYO, little is known regarding PCN degradation by far. Previous studies have speculated that its initial degradation step may be catalyzed by an amidase, but no further studies have been conducted. This study identified a novel amidase, PcnH, that catalyzed the hydrolysis of PCN to PCA. In addition, the PCA 1,2-dioxygenase PcaA1A2A3A4 and 2OHPC dioxygenase PcnD were also found to be involved in the subsequent degradation steps of PCN in S. histidinilytica DS-9. And the genes responsible for PCN catabolism are highly conserved in some strains of Sphingomonas. These results deepen our understanding of the PCN degradation mechanism.

Role of Butylphthalide in Immunity and Inflammation: Butylphthalide May Be a Potential Therapy for Anti-Inflammation and Immunoregulation.

Inflammation and immunity play an essential role in disease pathogenesis. 3-N-Butylphthalide (NBP), a group of compounds extracted from seeds of Apium graveolens (Chinese celery), has been demonstrated as an efficient and effective therapy for ischemic stroke. The amount of research on NBP protective effect is increasing at pace, such as microcircular reconstruction, alleviating inflammation, ameliorating brain edema and blood-brain barrier (BBB) damage, mitochondrial function protection, antiplatelet aggregation, antithrombosis, decreasing oxidative damage, and reducing neural cell apoptosis. There has been increasing research emphasizing the association between NBP and immunity and inflammation in the past few years. Hence, it is aimed at reviewing the related literature and summarizing the underlying anti-inflammatory and immunoregulatory function of NBP in various disorders.

Effect of Different Dietary Regimes on the Gut Microbiota and Fecal Metabolites of Père David's Deer.

A deep understanding of the effect of seasonal dietary changes on the nutrition and health of Père David's deer in Dafeng Reserve will contribute greatly to Père David's deer's protection. In this reserve, there were three seasonal dietary regimes: feeding on naturally occurring plants (PLANT diet), silage (SILAGE diet), and a combination of natural plants and silage (COMB diet). To some extent, the COMB diet reflects the seasonal transition from silage to the all-natural plant diet, especially in early spring. However, little is known regarding the gut microbiota changes and metabolic consequences under the COMB diet. Based on 16S rRNA sequencing and ultra-high performance liquid chromatography combined with tandem mass spectrometry, the gut microbiota and fecal metabolites of Père David's deer under these three diets were compared. Results showed the alpha diversity of the gut microbiota was significantly lower under the COMB diet compared to either the SILAGE or PLANT diets. Although no significant changes were observed in the core phyla, Firmicutes and Bacteroidetes, among the three dietary regimes, a significant lower abundance of several other phyla (Spirochaetes, Melainabacteria, Proteobacteria, and Verrucobacteria) was observed in the COMB diet compared to the SILAGE diet. A greater number of fecal metabolite differences was identified between the COMB and SILAGE or COMB and PLANT diets than between the SILAGE and PLANT diets, suggesting that the COMB diet had more of an effect on the metabolism of Père David's deer. The integrated pathway analysis showed that several metabolic pathways were significantly affected by the different dietary regimes, such as tryptophan metabolism, vitamin metabolism, and the platelet activation pathways. These metabolic changes reflect the responses and adaptations of Père David's deer to different diets. Taken overall, our data reveal the difference in the gut microbiota and metabolic pathways of Père David's deer under three dietary regimes in Dafeng Reserve, which provides important information for Père David's deer conservation.

An Innovative Prone Position Using a Body-Shape Plaster Bed and Skull Traction for Posterior Cervical Spine Fracture Surgeries.

Background: An innovative prone cervical spine surgical position using a body-shape plaster bed with skull traction (BSPST) was compared with the traditional prone surgical position with horseshoe headrests. Methods: A total of 47 patients, undergoing posterior cervical spine surgery for cervical spine fracture, were retrospectively classified into two groups, the BSPST group (n = 24) and the traditional group (n = 23), and underwent a posterior instrumented fusion with or without decompression. Multiple indicators were used to evaluate the advantages of the BSPST compared with the traditional position. Results: All the operations went smoothly. The mean recovery rate was 56.30% in the BSPST group and 48.55% in the traditional group (p = 0.454), with no significant difference. The intraoperative blood loss (177.5 ml vs. 439.1 ml, p = 0.003) and the total incidence of complications (8.3 vs. 47.8%, p = 0.004) were significantly less in the BSPST group than in the traditional group. In addition, the BSPST position provided a greater comfort level for the operators and allowed convenient intraoperative radiography. Conclusions: This is the first study to describe a combined body-shape plaster bed and skull traction as an innovative cervical spine-prone surgical position that is simple, safe, and stable, intraoperative traction direction adjustable, reproducible, and economical for posterior cervical spine fracture surgery, and potentially other cervical and upper dorsal spine surgeries in the prone position. Additionally, this position provides the surgeons with a comfortable surgical field and can be easily achieved in most orthopedic operation rooms.

Two LysR Family Transcriptional Regulators, McbH and McbN, Activate the Operons Responsible for the Midstream and Downstream Pathways, Respectively, of Carbaryl Degradation in Pseudomonas sp. Strain XWY-1.

Previously, a LysR family transcriptional regulator, McbG, that activates the mcbBCDEF gene cluster involved in the upstream pathway (from carbaryl to salicylate) of carbaryl degradation in Pseudomonas sp. strain XWY-1 was identified by us (Z. Ke, Y. Zhou, W. Jiang, M. Zhang, et al., Appl Environ Microbiol 87:e02970-20, 2021, https://doi.org/10.1128/AEM.02970-20). In this study, we identified McbH and McbN, which activate the mcbIJKLM cluster (responsible for the midstream pathway, from salicylate to gentisate) and the mcbOPQ cluster (responsible for the downstream pathway, from gentisate to pyruvate and fumarate), respectively. They both belong to the LysR family of transcriptional regulators. Gene disruption and complementation study reveal that McbH is essential for transcription of the mcbIJKLM cluster in response to salicylate and McbN is indispensable for the transcription of the mcbOPQ cluster in response to gentisate. The results of electrophoretic mobility shift assay (EMSA) and DNase I footprinting showed that McbH binds to the 52-bp motif in the mcbIJKLM promoter area and McbN binds to the 58-bp motif in the mcbOPQ promoter area. The key sequence of McbH binding to the mcbIJKLM promoter is a 13-bp motif that conforms to the typical characteristics of the LysR family. However, the 12-bp motif that is different from the typical characteristics of the LysR family regulator binding site sequence is identified as the key sequence for McbN to bind to the mcbOPQ promoter. This study revealed the regulatory mechanisms for the midstream and downstream pathways of carbaryl degradation in strain XWY-1 and further our knowledge of (and the size of) the LysR transcription regulator family. IMPORTANCE The enzyme-encoding genes involved in the complete degradation pathway of carbaryl in Pseudomonas sp. strain XWY-1 include mcbABCDEF, mcbIJKLM, and mcbOPQ. Previous studies demonstrated that the mcbA gene, responsible for hydrolysis of carbaryl to 1-naphthol, is constitutively expressed and that the transcription of mcbBCDEF was regulated by McbG. However, the transcription regulation mechanisms of mcbIJKLM and mcbOPQ have not been investigated yet. In this study, we identified two LysR-type transcriptional regulators, McbH and McbN, which activate the mcbIJKLM cluster (responsible for the degradation of salicylate to gentisate) and the mcbOPQ cluster (responsible for the degradation of gentisate to pyruvate and fumarate), respectively. The 13-bp motif is critical for McbH to bind to the promoter of mcbIJKLM, and 12-bp motif different from the typical characteristics of the LysR-type transcriptional regulator (LTTR) binding sequence affects the binding of McbN to the promoter. These findings help to expand the understanding of the regulatory mechanism of microbial degradation of carbaryl.

A novel hydrolase PyzH catalyses the cleavage of C=N double bond for pymetrozine degradation in Pseudomonas sp. BYT-1.

Pymetrozine is a synthetic pesticide that can be utilized as the sole carbon source by Pseudomonas sp. strain BYT-1. However, the genes involved in the degradation of pymetrozine remain unknown. We used transposon mutagenesis to create a mutant that unable to hydrolyze pymetrozine. The transposon interrupted the gene pyzH, which was cloned by self-formed adaptor PCR. PyzH hydrolyzed the C=N double bond of pymetrozine to produce 4-amino-6-methyl-4,5-dihydro-2H-[1,2,4]triazin-3-one (AMDT) and nicotinaldehyde; the latter inhibits PyzH activity. PyzH can completely hydrolyze pymetrozine in the presence of dehydrogenase ORF6, which can convert nicotinaldehyde into nicotinic acid and relieve the inhibition. H2 18 O-labeling experiments showed that the oxygen atom of nicotinaldehyde came from water instead of oxygen. PyzH homologous genes were also found in other soil isolates able to degrade pymetrozine.

McbG, a LysR Family Transcriptional Regulator, Activates the mcbBCDEF Gene Cluster Involved in the Upstream Pathway of Carbaryl Degradation in Pseudomonas sp. Strain XWY-1.

Although enzyme-encoding genes involved in the degradation of carbaryl have been reported in Pseudomonas sp. strain XWY-1, no regulator has been identified yet. In the mcbABCDEF cluster responsible for the upstream pathway of carbaryl degradation (from carbaryl to salicylate), the mcbA gene is constitutively expressed, while mcbBCDEF is induced by 1-naphthol, the hydrolysis product of carbaryl by McbA. In this study, we identified McbG, a transcriptional activator of the mcbBCDEF cluster. McbG is a 315-amino-acid protein with a molecular mass of 35.7 kDa. It belongs to the LysR family of transcriptional regulators and shows 28.48% identity to the pentachlorophenol (PCP) degradation transcriptional activation protein PcpR from Sphingobium chlorophenolicum ATCC 39723. Gene disruption and complementation studies reveal that mcbG is essential for transcription of the mcbBCDEF cluster in response to 1-naphthol in strain XWY-1. The results of the electrophoretic mobility shift assay (EMSA) and DNase I footprinting show that McbG binds to the 25-bp motif in the mcbBCDEF promoter area. The palindromic sequence TATCGATA within the motif is essential for McbG binding. The binding site is located between the -10 box and the transcription start site. In addition, McbG can repress its own transcription. The EMSA results show that a 25-bp motif in the mcbG promoter area plays an important role in McbG binding to the promoter of mcbG This study reveals the regulatory mechanism for the upstream pathway of carbaryl degradation in strain XWY-1. The identification of McbG increases the variety of regulatory models within the LysR family of transcriptional regulators.IMPORTANCEPseudomonas sp. strain XWY-1 is a carbaryl-degrading strain that utilizes carbaryl as the sole carbon and energy source for growth. The functional genes involved in the degradation of carbaryl have already been reported. However, the regulatory mechanism has not been investigated yet. Previous studies demonstrated that the mcbA gene, responsible for hydrolysis of carbaryl to 1-naphthol, is constitutively expressed in strain XWY-1. In this study, we identified a LysR-type transcriptional regulator, McbG, which activates the mcbBCDEF gene cluster responsible for the degradation of 1-naphthol to salicylate and represses its own transcription. The DNA binding site of McbG in the mcbBCDEF promoter area contains a palindromic sequence, which affects the binding of McbG to DNA. These findings enhance our understanding of the mechanism of microbial degradation of carbaryl.