Objective: To identify an optimal back-flush solution for leukocyte-depleted filters that maximizes peripheral blood mononuclear cell (PBMC) recovery with high viability, long-term storage stability, and sterility of the harvested residues, thereby providing a clinically translatable strategy. Methods: Three sterile bag-packaged solutions—Saline, Solvent, and Hanks' balanced salt solution (HBSS)—were used to back-flush randomly assigned leukocyte-depleted filters. Nucleated cell recovery rate and viability of the harvested residues were compared. The optimal solution identified was applied to an expanded sample set. PBMC viability and yield were evaluated after 1h vs 48h storage of the residues. PBMCs isolated from the residues were cryopreserved in liquid nitrogen for 1 month, followed by post-thaw comparisons of viability and T-cell expansion capacity. Results: The Solvent group achieved the highest and most consistent nucleated cell recovery rate. Post-flush recovery rate from filters after 400 mL whole blood processing was (21.3±1.6)% for the Solvent group, significantly higher than Saline group (19.2±6.3)% and HBSS group (11.2±5.0)%, with residues from all groups maintaining viability >90%. No biologically significant difference in residue viability was observed between 48h vs 1h storage groups (93.3±2.3)% vs (95.7±1.8)%). PBMC recovery rates from residues showed no statistical difference between 48h vs 1h storage groups [(48.2%±9.5%)vs (40.41%±8.35%), P>0.05], with (17.7±2.6)×10 cells. After 1-month cryopreservation and 10-day expansion, PBMCs isolated from 48-hour-stored residues retained (91.2±3.2)% viability and achieved a (61.9±15.9)-fold expansion. Conclusion: The bag-packaged Solvent, as a back-flush solution, enables sterile acquisition of leukocyte-depleted filter residues through closed-system tubing connections. These residues maintained PBMC viability and recovery rates after 48h storage at 2℃-8℃, with post-cryopreservation (1-month liquid nitrogen) viability and expansion capacity remaining stable. This protocol complies with blood bank regulatory criteria, addresses the concerns about the infectious window period in cell therapy raw materials, and provides a clinically translatable strategy for PBMC-based applications.

OBJECTIVES: To characterize the biological properties of double-negative T (DNT) cells isolated from leukoreduction filter residues. METHODS: Leukoreduction filters containing residues from 400 mL whole blood units (n=6) were collected from a blood center. Filters were back-flushed with normal saline, and the eluate was concentrated to obtain leukoreduction filter residues. Leukocytes in the residues were counted by dual-fluorescence staining. DNT cells were then isolated from the residues using antibody-mediated adsorption and density gradient centrifugation. Both cryopreserved and fresh unstimulated DNT cells derived from the residues were subjected to in vitro culture. Following culture, cells were assessed for expansion fold, viability, immunophenotype, differentiation status, and cytotoxicity against target cells using dual-fluorescence staining and flow cytometry, with comparisons made to DNT cells derived from whole blood. RESULTS: The leukocyte recovery rate achieved through reverse flushing of the leukocyte reduction filter was (41.9±14.7)%. Compared to whole blood, the DNT cell starting material obtained from filter residues showed no significant difference in total T-cell content (P>0.05). However, the viability and purity of the resulting DNT cell starting materials were significantly lower (both P<0.05). After 17 days of culture, DNT cells from filter residues and whole blood showed no significant differences in expansion fold, immunophenotype, differentiation status, or cytotoxicity toward target cells (all P>0.05). However, the viability of DNT cells from residues was significantly lower than that of whole blood-derived DNT cells [(86.0±4.2)% vs. (92.2±1.2)%, P<0.05]. After thawing (post 3 or 15 days of cryopreservation) and 17 days of culture, DNT cell starting materials from residues showed comparable immunophenotype, expansion fold, and differentiation status to their non-cryopreserved counterparts from the same source (all P>0.05). However, the viability of DNT cells cryopreserved for 3 days [92.4% (91.8%, 92.8%)] and the cytotoxicity against target cells of those cryopreserved for 15 days [91.3% (89.4%, 95.1%)] were significantly higher than those of non-cryopreserved DNT cells [87.8% (82.0%, 89.0%) and 70.9% (67.3%, 80.2%), respectively] (P<0.05). CONCLUSIONS DNT cells derived from leukoreduction filter residues exhibited highly comparable characteristics to those from whole blood in terms of expansion, purity, differentiation, and biological potency. Furthermore, their biological activity post-cryopreservation and revival remained largely similar to non-cryopreserved cells. These findings suggest that leukoreduction filter residues represent a promising alternative source of starting material for manufacturing off-the-shelf, allogeneic DNT cell therapeutics.

Metformin has been demonstrated to attenuate hyperglycaemia by modulating the gut microbiota. However, the mechanisms through which the microbiome mediates metformin monotherapy failure (MMF) are unclear. Herein, in a prospective clinical cohort study of newly diagnosed type 2 diabetes mellitus (T2DM) patients treated with metformin monotherapy, metagenomic sequencing of faecal samples revealed that Phocaeicola vulgatus abundance was approximately 12 times higher in nonresponders than in responders. P. vulgatus rapidly hydrolysed taurine-conjugated bile acids, leading to ceramide accumulation and reversing the improvements in glucose intolerance conferred by metformin in high-fat diet-fed mice. Interestingly, C22:0 ceramide bound to mitochondrial fission factor to induce mitochondrial fragmentation and impair hepatic oxidative phosphorylation in P. vulgatus-colonized hyperglycaemic mice, which could be exacerbated by metformin. This work suggests that metformin may be unsuitable for P. vulgatus-rich T2DM patients and that clinicians should be aware of metformin toxicity to mitochondria. Suppressing P. vulgatus growth with cefaclor or improving mitochondrial function using adenosylcobalamin may represent simple, safe, effective therapeutic strategies for addressing MMF.

Although a single nucleotide polymorphism for N-acetyltransferase 10 (NAT10) has been identified in patients with early-onset stroke, the role of NAT10 in ischemic injury and the related underlying mechanisms remains elusive. Here, we provide evidence that NAT10, the only known RNA N4-acetylcytidine (ac4C) modification "writer", is increased in the damaged cortex of patients with acute ischemic stroke and the peri-infarct cortex of mice subjected to photothrombotic (PT) stroke. Pharmacological inhibition of NAT10 with remodelin on Days 3-7 post-stroke or astrocytic depletion of NAT10 via targeted virus attenuates ischemia-induced infarction and improves functional recovery in PT mice. Mechanistically, NAT10 enhances ac4C acetylation of the inflammatory cytokine tissue inhibitor of metalloproteinase 1 (Timp1) mRNA transcript, which increases TIMP1 expression and results in the accumulation of microtubule-associated protein 1 light chain 3 (LC3) and progression of astrocyte autophagy. These findings demonstrate that NAT10 regulates astrocyte autophagy by targeting Timp1 ac4C after stroke. This study highlights the critical role of ac4C in the regulation of astrocyte autophagy and proposes a promising strategy to improve post-stroke outcomes via NAT10 inhibition.

O-acetyl-L-homoserine (OAH) is a promising platform compound for the production of L-methionine and other valuable compounds, while its low yield and low conversion rate limit the industrial application. To solve these problems, we constructed a strain for high OAH production with the previously constructed L-homoserine producer Escherichia coli HS33 as the chassis by systematic metabolic engineering. Firstly, PEP accumulation, pyruvate utilization, and OAH synthesis pathway (overexpressing aspB, aspA, and thrA^C1034T) were enhanced to obtain an initial strain accumulating 13.37 g/L OAH. Subsequently, the co-factor synthesis genes were integrated to supply reducing power and energy, which increased the yield to 15.79 g/L. The OAH yield of the engineered strain OAH28 was further increased to 17.49 g/L by strengthening the acetic acid reuse pathway, improving the supply of acetyl-CoA, and regulating the expression of MetX from different sources. Finally, in a 5 L fermenter, OAH28 achieved an OAH titer of 47.12 g/L, with a glucose conversion rate of 32% and productivity of 0.59 g/(L·h). The results lay a foundation for increasing the OAH production by metabolic engineering and give insights into the industrial production of OAH.
Metabolic Engineering/methods* ; Escherichia coli/genetics* ; Homoserine/biosynthesis* ; Fermentation

Synthetic biology is a crucial tool for the development of the bio-industry and bio-economy, representing a significant aspect of new quality productive forces. As a core course for graduate students in bioengineering, Synthetic Biology plays a vital role in ensuring the supply of essential talents for the development of the bio-industry in the new era. To better serve regional economic development and provide high-level talents for China's progress in the bio-industry, we analyzed typical issues encountered in the past teaching activities, set up a multi-disciplinary teaching team, optimized the course contents, adjusted the teaching mode, and mobilized students' learning interest. With the application of scientific research project as the starting point, we guided students to think and discuss deeply through the simulation of application writing and project defense, which improved students' critical thinking and innovative thinking. With industrialization as a focus, we explored a new training model combining production, education, and research through the joint practice base of the university and enterprises introduced typical cases of biomanufacturing to encourage students to engage in scientific research. The teaching reform significantly enhances the comprehensive abilities and national sentiments of graduate students. This paper hopes to serve as a reference for colleagues engaged in teaching in this field.
Synthetic Biology/education* ; Teaching ; China ; Humans

Objective:To develope a titanium specimen with good osteogenic activity through fabrication of a composite hydroxyapatite coating on ordered micro-/nanotextured titanium surface.Methods:An ordered micro-/nanotextured structure was prepared on the surface of titanium (the control), and then hydroxyapatite was deposited on the as-prepared ordered micro-/nanotextured structure by alternative loop immersion method. The ordered micro-/nanotextured structures before and after hydroxyapatite deposition were denoted as HA and MN, respectively. Surface morphology was observed using a scanning electron microscope. Bone marrow mesenchymal stem cells (BMMSC) were seeded on the surface of three different materials. Cell morphology was observed with a scanning electron microscope. Cell adhesion and cell proliferation were evaluated using 4', 6-diamidino-2-phenylindole staining and cell counting kit-8 assay, respectively. Extracellular matrix mineralization and the expression levels of osteogenesis-related genes were evaluated by alizarin red staining and real-time quantitative PCR, respectively. Each group has three samples in every experiment.Results:After alternative loop immersing, the MN's original microholes (20 μm in diameter) were retained, and the uniform petal-like hydroxyapatite was deposited on the MN's original titania nanotubes (70 nm in diameter). Compared with the control, BMMSC on MN and HA elongated further and intersected along the micron structure with noticeable pseudopodia and pseudoplates, and the trend was more pronounced especially on HA. The number of early adherent cells on HA was remarkably larger than that on the control and MN at each time point ( P<0.05). On day 1, the A value of cell proliferation on HA was significantly higher than that on the control and MN ( P<0.05). The A value of cell proliferation on HA was significantly lower than that on the control and MN on day 3 ( P<0.05). On day 7, the A value of cell proliferation on HA was significantly lower than that on MN ( P<0.05), but there was no statistically significant difference in the A value of cell proliferation between HA and the control on day 7 ( P>0.05). The Avalue of extracellular matrix mineralization on HA (0.607±0.011) was significantly higher than that on the control and MN (0.268±0.025 and 0.522±0.022, respectively) ( t=-0.25, P<0.001; t=-0.34, P<0.001). The expression levels of bone related genes on HA were significantly higher than those on the control and MN ( P<0.05). Conclusions:HA could promote the BMMSC adhesion and osteogenic differentiation, support BMMSC proliferation, and demonstrate good osteogenic activity.

In the aftermath of the pandemic,the government is accelerating the development of top-tier medical resources to broaden the supply and deliver superior healthcare services.However,during this transitional phase,hospitals are experiencing operational challenges due to concurrent construction activities.Notably,a shortage of parking facilities and increased traffic con-gestion continue to impactmedial consultation experience of patients.This paper tries to explore strategies and methods for dynam-ic parking management during hospital campus expansions,offering insights for other medical institutions into grappling with pa-tient parking issues.

Objective:To study the correlation between smoking and clinicopathology in patients with upper tract urothelial carcinoma(UTUC), and to evaluate the effect of smoking on the prognosis of patients with UTUC treated with adjuvant chemotherapy for Gemcitabine plus Cisplatin (GC).Methods:A retrospective cohort study was used to select 91 patients who underwent resection of the kidney and ureter, and sleeve cystectomy in Beijing Friendship Hospital, Capital Medical University from January 2013 to December 2021, all patient received GC adjuvant chemotherapy after surgery. Patients were divided into smoking group ( n=33) and non-smoking group ( n=58) according to their smoking history. The median follow-up time was 38 months (3-83 months). The age, gender, presence or absence of hydronephrosis, tumor stage, multifocality, lymphatic vascular invasion, lymphatic metastasis, tumor grade, overall survival (OS) and cancer-specific survival (CSS) were statistically analyzed. The measurement data were expressed as mean ± standard deviation ( ± s), and the t-test was used for comparison between groups; the count data were expressed as the number of cases and percentage, and the Chi-square test was used for comparison between groups. Kaplan-Meier curve was used for survival analysis and comparison, and Long-rank test was used for comparison between groups. Cox proportional risk regression model was introduced to explore the independent influencing factors of OS and CSS by univariate and multivariate Cox regression analysis. Results:Among 91 patients, 41 were males and 50 were females, with a median age of 65 years, and 19 patients (20.9%) died, of which 17 patients (18.7%) died of UTUC. The comparison of clinical indicators between the two groups showed that smoking was associated with male, tumor stage, multifocality, lymphatic vascular invasion, lymphaitc metastasis, and tumor grade and hydronephrosis ( P<0.05). Multivariate Cox regression analysis showed that smoking, male, higher tumor stage, and lymphatic vascular invasion were independent risk factors for OS and CSS. For the subgroup of patients who smoked, smoking duration significantly affected CSS, with each additional year of smoking duration increasing the risk of death by 0.065. Conclusion:Smoking is associated with adverse pathology in patients with UTUC, and smoking is an independent factor affecting the prognosis of postoperative adjuvant chemotherapy with GC in UTUC.

Background Arsenic, cobalt, barium, and other individual metal exposure have been confirmed to be associated with the incidence of kidney stones. However, there are few studies on the association between mixed metal exposure and kidney stones, especially in occupational groups. Objective To investigate the association between mixed metal exposure and kidney stones in an occupational population from a metal smelting plant. Methods A questionnaire survey was conducted to collect sociodemographic characteristics, medical history, and lifestyle information of 1158 mixed metal-exposed workers in a metal smelting plant in Guangdong Province from July 2021 to January 2022. Midstream morning urine samples were collected from the workers, the concentrations of 18 metals including lithium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, strontium, molybdenum, cadmium, cesium, barium, tungsten, titanium, and lead were measured by inductively coupled plasma mass spectrometry, and the urinary mercury levels were measured by cold atomic absorption spectroscopy. Based on predetermined inclusion criteria, a total of 919 mixed metal-exposed workers were included in the study, including 117 workers in the kidney stone group and 802 workers in the non-kidney stone group. With a detection rate of urinary metals greater than 80% as entry criterion, 16 eligible metals were finally included for further analysis. Parametric or non-parametric methods were used to compare the differences between continuous or categorical variables of the non-kidney stone group and the kidney stone group. Logistic regression models were constructed to explore the association between individual metal exposures and kidney stones. Weighted quantile sum (WQS) regression models were used to evaluate the association between mixed metal exposure and kidney stones, as well as the weights of each metal on kidney stones. Then Bayesian kernel machine regression (BKMR) models were used to explore the overall effect of mixed metal exposure on renal calculi and the potential interactions between metals. Results We found that there were significant differences in sex, age, length of service, and body mass Index (BMI) between the non-kidney stone group and the kidney stone group (P<0.05). The urinary concentrations of molybdenum and barium in the kidney stone group were higher than those in the non-kidney stone group, and the differences were statistically significant (P<0.05). The logistic regression models demonstrated that urinary cobalt, arsenic, molybdenum, and barium were positively correlated with the risk of kidney stones (P_trend<0.05). The WQS regression models showed that the mixed exposure to vanadium, cobalt, arsenic, molybdenum, and barium was positively associated with the risk of kidney stones (P<0.05). Among them, molybdenum, arsenic, and barium accounted for 0.391, 0.337, and 0.154, respectively. The BKMR results revealed a positive association between metal mixture exposure and the risk of kidney stones (P<0.05). When other metals were fixed at the 25th, 50th, or 75th percentile, arsenic, molybdenum, cobalt, and barium exhibited significant positive effects on the risk of kidney stones (P<0.05), while vanadium showed a significant negative effect (P<0.05). The interaction analysis demonstrated interactions between barium and cobalt, as well as between vanadium and cobalt (P<0.05). Conclusion In the occupational population of this smelter, occupational mixed metal exposure could increase the risk of kidney stones, and the main metals are molybdenum, arsenic, barium, and cobalt.