Sennoside A (SA), a typical prodrug, exerts its laxative effect only after its transformation into rheinanthrone catalyzed by gut microbial hydrolases and reductases. Hydrolases have been identified, but reductases remain unknown. By linking a photoreactive group to the SA scaffold, we synthesized a photoaffinity probe to covalently label SA reductases and identified SA reductases using activity-based protein profiling (ABPP). From lysates of an active strain, Bifidobacterium pseudocatenulatum (B. pseudocatenulatum), 397 proteins were enriched and subsequently identified using mass spectrometry (MS). Among these proteins, chromate reductase/nicotinamide adenine dinucleotide (NADH) phosphate (NADPH)-dependent flavin mononucleotide (FMN) reductase/oxygen-insensitive NADPH nitroreductase (nfrA) was identified as a potent SA reductase through further bioinformatic analysis and The Universal Protein Resource (UniProt) database screening. We also determined that recombinant nfrA could reduce SA. Our study contributes to further illuminating mechanisms of SA transformation to rheinanthrone and simultaneously offers an effective method to identify gut bacterial reductases.

•A strategy for in situ metabolically synthesized active drug-based probes was proposed.•The potential purgative targets of SA were successfully hooked and identified.•The work provided a new insight for studying the direct targets of unstable active drugs.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

BACKGROUND: P16 inactivation is frequently accompanied by telomerase reverse transcriptase ( TERT ) amplification in human cancer genomes. P16 inactivation by DNA methylation often occurs automatically during immortalization of normal cells by TERT . However, direct evidence remains to be obtained to support the causal effect of epigenetic changes, such as P16 methylation, on cancer development. This study aimed to provide experimental evidence that P16 methylation directly drives cancer development. METHODS: A zinc finger protein-based P16 -specific DNA methyltransferase (P16-Dnmt) vector containing a "Tet-On" switch was used to induce extensive methylation of P16 CpG islands in normal human fibroblast CCD-18Co cells. Battery assays were used to evaluate cell immortalization and transformation throughout their lifespan. Cell subcloning and DNA barcoding were used to track the diversity of cell evolution. RESULTS: Leaking P16-Dnmt expression (without doxycycline-induction) could specifically inactivate P16 expression by DNA methylation. P16 methylation only promoted proliferation and prolonged lifespan but did not induce immortalization of CCD-18Co cells. Notably, cell immortalization, loss of contact inhibition, and anchorage-independent growth were always prevalent in P16-Dnmt&TERT cells, indicating cell transformation. In contrast, almost all TERT cells died in the replicative crisis. Only a few TERT cells recovered from the crisis, in which spontaneous P16 inactivation by DNA methylation occurred. Furthermore, the subclone formation capacity of P16-Dnmt&TERT cells was two-fold that of TERT cells. DNA barcoding analysis showed that the diversity of the P16-Dnmt&TERT cell population was much greater than that of the TERT cell population. CONCLUSION P16 methylation drives TERT -mediated immortalization and transformation of normal human cells that may contribute to cancer development.
Humans ; Telomerase/genetics* ; DNA Methylation/physiology* ; Fibroblasts/cytology* ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Cell Line ; Cell Transformation, Neoplastic/genetics*

Listeria brainstem encephalitis with myelitis is extremely rare in clinical practice.Since the clinical manifestations are non-specific,MRI is helpful for diagnosis.Positive cerebrospinal fluid culture is considered the gold standard for diagnosis.This article reports a case of an immunocompetent individual with listeria brainstem encephalitis with myelitis,aiming to enhance the awareness of this condition.
Humans ; Brain Stem/pathology* ; Diagnostic Errors ; Encephalitis/complications* ; Encephalomyelitis, Acute Disseminated/diagnosis* ; Listeriosis/complications* ; Myelitis/complications*

Objective To investigate the population composition,seasonal dynamics,and infestation levels of cockroaches in Lanzhou,China,and to provide information for the scientific development of cockroach control strategies.Methods Monitoring was conducted at three locations using the sticky trap method.Habitats included farm product markets,catering establishments,hotels,hospitals,and residential areas.Results From 2016 to 2023,the average cockroach density was 0.77 insects per board,with an average infestation rate of 10.84%.Blattella germanica was the dominant species.Seasonal density of cockroaches showed an approximately unimodal distribution,peaking in September.The highest average density and infestation rates were observed in farm product markets.Conclusions Cockroach density and infestation levels in Lanzhou remained relatively low.A comprehensive prevention and control strategy focusing on environmental management in key areas should be implemented according to the seasonal fluctuations.

Objective:To establish an indicator system of entrustable professional activities (EPAs) for entering residency, and to provide support for targeted training and ability evaluation of entering residency.Methods:Based on the existing indicator systems of EPAs for entering residency in China and globally, two rounds of Delphi consultation were performed to identify and optimize the indicators for EPAs. The scores of indicators were evaluated using means and coefficient of variation, and the degree of expert authority and Kendall's W coefficient were used to test the reliability of results.Results:A total of 17 indicators for EPAs were established, which defined the entrustable level of each EPA that residents should reach at the time of entry and at the end of the first year.Conclusions:This study preliminarily establishes an indicator system of EPAs for entering residency.

BACKGROUND:Currently,the verification of the precision of personalized bone models is usually performed by methods such as paired t-tests or intraclass correlation coefficient,but such methods often require the production of large batches of models,which do not satisfy the need for immediate use of personalized models. OBJECTIVE:To study the feasibility of establishing the equivalent model to verify the precision of the personalized bone model rapidly. METHODS:Bone CT images of three adults were randomly obtained for reconstruction.3D printing was used to create personalized bone models,and then the personalized bone models were scanned using CT and reconstructed.Mimics was used to compare the reconstructed models of bone CT images with the bone CT images.Geomagic Studio was used to analyze the fitting deviation between the reconstruction model of personalized bone model CT image and the reconstruction model of skeletal CT image.The 3D-printed personalized bone model was measured against the measurement positions and dimensions marked on the reconstruction model of skeletal CT image,and the error was calculated. RESULTS AND CONCLUSION:(1)By comparing the reconstructed bone CT image model with the bone CT scan image,the two were compatible in terms of anatomical structure and morphology,and the contours almost overlapped.(2)By fitting bias analysis,the standard bias was 0.176,0.226,and 0.143 mm in order,and all the results were<0.25 mm.(3)By measuring and calculating the model,the mean relative errors were 0.44%,0.21%,and 0.13%,and all the results were within 5%error.(4)The constructed equivalent model was in line with the basic conditions for making personalized bone models.The established equivalent model met the clinical needs and design requirements,and it was feasible to use the method of the equivalent model to verify the precision of the personalized bone model quickly.(5)This method could provide a targeted and rapid way to verify the precision of personalized bone models.It could achieve the goal of providing immediate clinical use without the need to produce large batches of models compared to conventional methods such as paired t-tests or intraclass correlation coefficient.

OBJECTIVE To compare the effects of roxadustat and recombination human erythropoietin （rHuEPO） on coronary artery calcification in maintenance hemodialysis （MHD） patients. METHODS In retrospective analysis， MHD patients prescribed roxadustat in the Blood Purification Center of the First Affiliated Hospital of Chongqing Medical University from April 2019 to June 2021 were selected as the ROX group （56 patients）， and MHD patients prescribed rHuEPO during the same period were selected as the EPO group （60 patients）， and follow-up observation was conducted for 12 months. The differences in laboratory index， coronary artery calcification score （CACS）， and cardiac ultrasound parameters before and after treatment as well as the occurrence of cardiac and cerebrovascular adverse events during follow-up period were compared between the two groups. RESULTS There was no statistical difference in CACS between the two groups before and after treatment （P＞0.05）； but the difference of CACS in the ROX group was significantly lower than the EPO group （P＜0.05）. There was no statistically significant difference in cardiac ultrasound parameters and laboratory indexes between the two groups before and after treatment （P＜0.05）. The incidence of apoplexy and myocardial infarction in the ROX group was lower than that in the EPO group （P＜0.05）， and there was no statistically significant difference in the incidence of hospitalization due to heart failure between the two groups （P＞0.05）. CONCLUSIONS Compared with rHuEPO， roxadustat may have a positive effect on delaying coronary artery calcification in MHD patients and may be beneficial in reducing the incidence of myocardial infarction and apoplexy in MHD patients.