Rational design of short-chain dehydrogenase/reductase for enantio-complementary synthesis of chiral 1,2-diols by successive hydroxymethylation and reduction of aldehydes.

Enantiopure 1,2-diols are widely used in the production of pharmaceuticals, cosmetics, and functional materials as essential building blocks or bioactive compounds. Nevertheless, developing a mild, efficient and environmentally friendly biocatalytic route for manufacturing enantiopure 1,2-diols from simple substrate remains a challenge. Here, we designed and realized a step-wise biocatalytic cascade to access chiral 1,2-diols starting from aromatic aldehyde and formaldehyde enabled by a newly mined benzaldehyde lyase from Sphingobium sp. combined with a pair of tailored-made short-chain dehydrogenase/reductase from Pseudomonas monteilii (PmSDR-MuR and PmSDR-MuS) capable of producing (R)- and (S)-1-phenylethane-1,2-diol with 99% ee. The planned biocatalytic cascade could synthesize a series of enantiopure 1,2-diols with a broad scope (16 samples), excellent conversions (94%-99%), and outstanding enantioselectivity (up to 99% ee), making it an effective technique for producing chiral 1,2-diols in a more environmentally friendly and sustainable manner.

High salt condition alters LPS synthesis and induces the emergence of drug resistance mutations in Helicobacter pylori.

The burgeoning emergence of drug-resistant Helicobacter pylori strains poses a significant challenge to the clinical success of eradication therapies and is primarily attributed to mutations within drug-targeting genes that lead to antibiotic resistance. This study investigated the effect of high salt conditions on the occurrence of drug-resistance mutations in H. pylori. We found that high salt condition significantly amplifies the frequency of drug resistance mutations in H. pylori. This can be chiefly attributed to our discovery indicating that high salt concentration results in elevated reactive oxygen species (ROS) levels, initiating DNA damage within H. pylori. Mechanistically, high salt condition suppresses lipopolysaccharide (LPS) synthesis gene expression, inducing alterations in the LPS structure and escalating outer membrane permeability. This disruption of LPS synthesis attenuates the expression and activity of SodB, facilitates increased ROS levels, and consequently increases the drug resistance mutation frequency. Impairing LPS synthesis engenders a reduction in intracellular iron levels, leading to diminished holo-Fur activity and increased apo-Fur activity, which represses the expression of SodB directly. Our findings suggest a correlation between high salt intake and the emergence of drug resistance in the human pathogen H. pylori, implying that dietary choices affect the risk of emergence of antimicrobial resistance.IMPORTANCEDrug resistance mutations mainly contribute to the emergence of clinical antibiotic-resistant Helicobacter pylori, a bacterium linked to stomach ulcers and cancer. In this study, we explored how elevated salt conditions influence the emergence of drug resistance in H. pylori. We demonstrate that H. pylori exhibits an increased antibiotic resistance mutation frequency when exposed to a high salt environment. We observed an increase in reactive oxygen species (ROS) under high salt conditions, which can cause DNA damage and potentially lead to mutations. Moreover, our results showed that high salt condition alters the bacterium's lipopolysaccharide (LPS) synthesis, leading to a reduced expression of SodB in a Fur-dependent manner. This reduction, in turn, elevates ROS levels, culminating in a higher frequency of drug-resistance mutations. Our research underscores the critical need to consider environmental influences, such as diet and lifestyle, in managing bacterial infections and combating the growing challenge of antibiotic resistance.

Screening and affinity optimization of single domain antibody targeting the SARS-CoV-2 nucleocapsid protein.

The coronavirus disease 2019 (COVID-19) pandemic, which caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), lead to a crisis with devastating disasters to global public economy and health. Several studies suggest that the SARS-CoV-2 nucleocapsid protein (N protein) is one of uppermost structural constituents of SARS-CoV-2 and is relatively conserved which could become a specific diagnostic marker. In this study, eight single domain antibodies recognized the N protein specifically which were named pN01-pN08 were screened using human phage display library. According to multiple sequence alignment and molecular docking analyses, the interaction mechanism between antibody and N protein was predicted. ELISA results indicated pN01-pN08 with high affinity to protein N. To improve their efficacy, two fusion proteins were prepared and their affinity was tested. These finding showed that fusion proteins had higher affinity than single domain antibodies and will be used as diagnosis for the pandemic of SARS-CoV-2.

The relationship between lung CT features and serum cryptococcal antigen titers in localized pulmonary cryptococcosis patients.

BACKGROUND: To explore the associations of computed tomography (CT) image features with the serum cryptococcal antigen (CrAg) titers measured by the lateral flow assay (LFA) in localized pulmonary cryptococcosis patients. METHODS: A retrospective analysis of patients with pathologically confirmed pulmonary cryptococcosis admitted to the First Affiliated Hospital of Xiamen University from January 2016 to December 2022 was performed. Clinical data, CT results, serum CrAg-LFA test results, and follow-up data were collected and analyzed. RESULTS: A total of 107 patients with localized pulmonary cryptococcosis were included, of which 31 had a single lesion in chest CT and the other 76 had multiple lesions. The positivity rate was (94.74% vs 64.52%) and titers of serum CrAg-LFA (1.77 ± 0.87 vs 0.91 ± 0.98) in the multiple lesion group were higher than those in the single lesion group, respectively. Multivariate linear regression analysis showed that the serum CrAg titers were positively associated with the number of lesions (ß, 0.08; 95% CI, 0.05 to 0.12) and the lesion size (ß, 0.40; 95% CI, 0.31 to 0.50) after adjusting other covariates. The serum CrAg-LFA titers of 60 pulmonary cryptococcosis patients showed a decreasing trend with the reduction in pulmonary lesion size after effective therapy. CONCLUSION: In pulmonary cryptococcosis patients, the number and size of lung lesions are positively correlated with the titers of the serum CrAg-LFA test. The CrAg-LFA test could be a useful tool for the diagnosis, severity assessment, and therapeutic monitoring of localized pulmonary cryptococcosis patients.

Inter-algal associations and nutrients linked by Scenedesmus and Desmodesmus structure eukaryotic algal communities.

Eutrophication reduces the variability of the community composition of plankton. However, the mechanisms underlying the diversity and restructuring of eukaryotic algal communities remain unknown. This study analysed the diversity and compositional patterns of algal communities in shallow eutrophic lakes. It investigated how these communities were modified by key genera through mediating inter-algal associations under the influence of abiotic factors. Inter-algal associations explained more variance in algal communities than environmental variables, and variation in composition and diversity was primarily derived from Scenedesmus, Desmodesmus and Cryptomonas, rather than nutrients. Scenedesmus and Desmodesmus were positively correlated with the genera of Chlorophyta and formed the hub of the algal association network. When the relative abundance of Scenedesmus and Desmodesmus increased from 0.41% to 13.74%, communities enriched in biomarkers of Bacillariophyta, Chrysophyceae and Cryptophyta transitioned to communities enriched in biomarkers of Chlorophyta. Moreover, negative associations between the Chlorophyta hub genera and other non-Chlorophyta genera increased. High concentrations of total phosphorus altered the composition of algal communities by increasing the abundance of Scenedesmus and Desmodesmus, which in turn had cascading effects through inter-algal associations. Additionally, algal communities with higher abundances of Scenedesmus and Desmodesmus were more susceptible to the effects of total phosphorus. Our study suggested that inter-algal associations, centred on Scenedesmus and Desmodesmus, had a greater influence on algal diversity and community structure than other factors. Nutrient levels were not a direct driver of algal diversity and community structure adjustments, but acted indirectly by enhancing the influence of Scenedesmus and Desmodesmus.

Immobilization of laccase on mesoporous metal organic frameworks for efficient cross-coupling of ethyl ferulate.

Laccases act as green catalysts for oxidative cross-coupling of phenolic antioxidnt compounds, but low stability and non-recyclability limit its application. To address that, metal-organic frameworks Cu-BTC and Cr-MOF were synthesized as supports to immobilize the efficient laccase from Cerrena sp. HYB07. The Brunauer-Emmett-Teller surface area of Cu-BTC and Cr-MOF were 1213.2 and 907.1 m2/g, respectively. The two carriers respectively presented pore diameters of 1.2-10 nm and 1.4-12 nm as octahedron, indicating nano-scale mesoporosity. These Cu-BTC and Cr-MOF carriers could adsorb laccase with enzyme loading of 1933.2 and 1564.4 U/g carrier, respectively. The stability and organic solvent tolerance of Cu-BTC-laccase and Cr-MOF-laccase were both obviously improved compared to free laccase. Thermal inactivation kinetics showed that both the two immobilized laccases displayed lower thermal inactivation rate constants. Importantly, the Cu-BTC-laccase and Cr-MOF-laccase both showed much higher activity for cross-coupling of ethyl ferulate than free laccase, which had 2.5-fold higher cross-coupling efficiency than that by free laccase. The ethyl ferulate coupling product was also analyzed by mass spectroscopy and the synthesis pathway of ethyl ferulate dimer was proposed. The cross coupling of ethyl ferulate required the formation of radical intermediates of ethyl ferulate generated by laccase mediated oxidation. This work paved the way for MOFs immobilized laccase for cross coupling of antioxidant phenols.

Differential effects of clopidogrel and/or aspirin on the healing of tooth extraction wound bone tissue.

Introduction: A multitude of variables influence the healing of tooth extraction wounds, and delayed or non-healing extraction wounds might complicate later prosthodontic therapy. In this research, we analyzed the effects of systemic clopidogrel and aspirin alone or in combination on the healing of tooth extraction wounds in mice in order to provide experimental evidence for the healing of extraction wounds in patients who are clinically treated with the two medicines. Methods: 7-week-old ICR mice were randomly divided into four groups: control group (CON), clopidogrel group (CLOP), aspirin group (ASP), and clopidogrel combined with aspirin group (CLOP + ASP); left upper first molar was extracted, after which mice in 1 week of adaptive feeding, CLOP/ASP/CLOP + ASP groups were respectively administered with clopidogrel (10 mg/kg/d), aspirin (15 mg/kg/d), clopidogrel (10 mg/kg/d)+aspirin (15 mg/kg/d), and the control group was given an equal amount of 0.9% saline by gavage. Mice in each group were euthanized at 14 and 28 days postoperatively, and the maxilla was extracted. The tissues in the extraction sockets were examined using MicroCT and sectioned for HE staining, Masson staining, and TRAP staining, and immunohistochemistry staining (for TRAP, RANKL and osteoprotegerin). Results: MicroCT analysis showed that at day 14, BS/BV was significantly lower in CLOP and CLOP + ASP groups compared to control and ASP groups, while BV/TV, Tb.Th was significantly higher. At day 28, BV/TV was significantly higher in the CLOP + ASP group compared to the CLOP group, with p < 0.05 for all results. HE staining and Masson trichrome staining findings revealed that at day 28, the mesenchyme in the bone was further decreased compared to that at day 14, accompanied with tightly arranged and interconnected bone trabeculae. In the quantitative analysis of Masson, the fraction of newly formed collagen was significantly higher in the CLOP group in comparison with that in the CON group (p < 0.05). At day 14, the ASP group had substantially more TRAP-positive cells than the CLOP and CLOP + ASP groups (p < 0.05). In immunohistochemical staining, RANKL expression was found to be significantly higher in the ASP group than those in the other three groups at day 28 (p < 0.05); OPG expression was significantly higher in the CLOP group and the CLOP + ASP group compared with that at day 14, and was higher than that in the ASP group at day 14 and day 28. OPG/RANKL was significantly higher in the CLOP and the CLOP + ASP groups than in the ASP group (p < 0.05). Conclusion: Clopidogrel alone promotes osteogenesis in the extraction wound, whereas aspirin alone inhibits alveolar bone healing. When the two drugs were combined, the healing effect of the extraction wound was more similar to that of the clopidogrel alone group. These results indicated that clopidogrel could promote the healing of the tooth extraction wound, and neutralize the adverse effect of ASP on osteogenesis when the two drugs were used in combination.

SMARCA4-deficient undifferentiated tumor with high quality of life and far exceeding predicted survival: A case report.

RATIONALE: SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a recently reported rare malignancy that can rapidly metastasize to tissues and organs throughout the body. The tumor is characterized by a lower response to platinum-based chemotherapy. More regrettably, the mean survival time of patients with this disease after diagnosis is only 4 to 7 months. PATIENT CONCERNS: A 58-year-old man was admitted to a hospital for fatigue, sudden syncope, and a mass-like shadow of his left upper lobe demonstrated by a pulmonary computed tomographic. Based on his subsequent clinical and pathological features, he was highly suspected of SMARCA4-UT. DIAGNOSES: Combined with next-generation sequencing genetic testing and immunohistochemical examination results, the patient was diagnosed with SMARCA4-UT. INTERVENTIONS: The patient received a left upper lobectomy and lymph node dissection, four-course chemotherapy divided into 8 sessions with the use of paclitaxel simply, and a proper post-discharge self-care. OUTCOMES: The patient's operation and chemotherapy were all successful and he maintained a high quality of life after surgery that far exceeded his predicted survival. LESSONS: Early diagnosis, higher education level, attention to the disease and complications, reducing chemotherapy damage, adequate nutrient intake, relieving symptoms, controlling depression, and maintaining immunity and the ability to perform activities of daily living may all be the positive factors that can prolong the survival of patients with SMARCA4-UT.

Rational design on loop regions for precisely regulating flexibility of catalytic center to mitigate overoxidation of prazole sulfides by Baeyer-Villiger monooxygenase.

S-omeprazole and R-rabeprazole are important proton pump inhibitors (PPIs) used for treating peptic disorders. They can be biosynthesized from the corresponding sulfide catalyzed by Baeyer-Villiger monooxygenases (BVMOs). During the development of BVMOs for target sulfoxide preparation, stereoselectivity and overoxidation degree are important factors considered most. In the present study, LnPAMO-Mu15 designed previously and TtPAMO from Thermothelomyces thermophilus showed high (S)- and (R)-configuration stereoselectivity respectively towards thioethers. TtPAMO was found to be capable of oxidating omeprazole sulfide (OPS) and rabeprazole sulfide (RPS) into R-omeprazole and R-rabeprazole respectively. However, the overoxidation issue existed and limited the application of TtPAMO in the biosynthesis of sulfoxides. The structural mechanisms for adverse stereoselectivity between LnPAMO-Mu15 and TtPAMO towards OPS and the overoxidation of OPS by TtPAMO were revealed, based on which, TtPAMO was rationally designed focused on the flexibility of loops near catalytic sites. The variant TtPAMO-S482Y was screened out with lowest overoxidation degree towards OPS and RPS due to the decreased flexibility of catalytic center than TtPAMO. The success in this study not only proved the rationality of the overoxidation mechanism proposed in this study but also provided hints for the development of BVMOs towards thioether substrate for corresponding sulfoxide preparation.

Layer-by-layer fabrication of covalent organic frameworks on stainless steel needles as solid-phase microextraction probe coupled with electrospray ionization mass spectrometry for enrichment and determination of tyrosine kinase inhibitors in biosamples.

Sunitinib, N-desmethyl imatinib, dasatinib, imatinib, and bosutinib are tyrosine kinase inhibitors (TKIs) that are commonly employed in the treatment of a multitude of cancers. However, the inappropriate concentrations of TKIs can result in ineffective treatment or the emergence of multiple adverse effects. Consequently, the development of a rapid and sensitive analytical method for TKIs is of paramount importance for the safe administration of drugs. In this work, solid-phase microextraction (SPME) probe combined with an electrospray ionization mass spectrometry (ESI-MS) coupling platform was constructed for rapid and sensitive determination of TKIs. The covalent organic frameworks (COFs) coated SPME probe was made of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and 2,5-dibutoxyterephthalaldehyde (DBTA) by in-situ layer-by-layer chemical bonding synthesis strategy. The TAPT-DBTA-SPME probe exhibited several advantageous properties which rendered it suitable for the enrichment of TKIs. Under the optimal conditions, the developed analytical method demonstrated a broad linear range (0.05-500.00 µg/L), a low limit of detection (0.02 µg/L) and a high enrichment factor (51-203) for TKIs. The developed analytical method was successfully applied to a pharmacokinetic study of TKIs in mouse plasma and tissue matrix, demonstrating that the proposed analytical method has promise for clinical applications and metabolic monitoring.

Efficiently manufacturing ectoine via metabolic engineering and protein engineering of L-2,4-diaminobutyrate transaminase.

Ectoine, so-called tetrahydropyrimidine, is an important osmotic adjustment solute and widely applied in cosmetics and protein protectant. Some attempts have been made to improve the ectoine productivity. However, the strains with both high ectoine production capacity and high glucose conversion were still absent so far. Aim to construct a strain for efficiently producing ectoine, ectoine synthetic gene cluster ectABC from Pseudomonas stutzeri was overexpressed in E. coli BL21 (DE3). The ection production was improved by 382 % (ectoine titer increased from 1.73 g/L to 8.33 g/L) after the rational design of rate-limiting enzyme L-2,4-diaminobutyrate transaminase EctBps (protein engineering) combined with the metabolic engineering that focused on the enrichment and conversion of precursors. The final strain YW20 was applied to overproduce ectoine in fed-batch fermentation and yield 68.9 g/L of ectoine with 0.88 g/L/h of space-time yield and the highest glucose conversion reported [34 % (g/g)]. From the fermentation broth, ectoine was purified with 99.7 % purity and 79.8 % yield. This study successfully provided an engineered strain as well as an efficient method for the industrial bio-synthesis and preparation of ectoine.

Melatonin partially rescues defects induced by tranexamic acid exposure during oocyte maturation in mice.

Tranexamic acid (TXA) is widely used among young women because of its ability to whiten skin and treat menorrhagia. Nevertheless, its potential effects on oocyte maturation and quality have not yet been clearly clarified. Melatonin (MT) is an endogenous hormone released by the pineal gland and believed to protect cells from oxidative stress injury. In the present study, we used an in vitro maturation model to investigate the toxicity of TXA and the protective role of MT in mouse oocytes. Compared with the control group, the TXA-exposed group had significantly lower nuclear maturation (57.72% vs. 94.08%, P < 0.001) and early embryo cleavage rates (38.18% vs. 87.66%, P < 0.001). Further study showed that spindle organization (52.56% vs. 18.77%, P < 0.01) and chromosome alignment (33.23% vs. 16.66%, P < 0.01) were also disrupted after TXA treatment. Mechanistically, we have demonstrated that TXA induced early apoptosis of oocytes (P < 0.001) by raising the level of reactive oxygen species (P < 0.001), which was consistent with an increase in mitochondrial damage (P < 0.01). Fortunately, all these effects except the spindle defect were successfully rescued by an appropriate level of MT. Collectively, our findings indicate that MT could partially reverse TXA-induced oocyte quality deterioration in mice by effectively improving mitochondrial function and reducing oxidative stress-mediated apoptosis.NEW & NOTEWORTHY Tranexamic acid is increasingly used to whiten skin, reverse dermal damages, and treat heavy menstrual bleeding in young women. However, its potential toxicity in mammalian oocytes is still unclear. Our study revealed that tranexamic acid exposure impaired the mouse oocyte quality and subsequent embryo development. Meanwhile, melatonin has been found to exert beneficial effects in reducing tranexamic acid-induced mitochondrial dysfunction and oxidative stress.

Validation of a Novel Mobile Application for Assessing Pediatric Tracheostomy Emergency Simulations.

Objective: Pediatric tracheostomy is associated with high morbidity and mortality, yet clinician knowledge and quality of tracheostomy care may vary widely. In situ simulation is effective at detecting and mitigating related latent safety threats, but evaluation via retrospective video review has disadvantages (eg, delayed analysis, and potential data loss). We evaluated whether a novel mobile application is accurate and reliable for assessment of in situ tracheostomy emergency simulations. Methods: A novel mobile application was developed for assessment of tracheostomy emergency in situ simulation team performance. After 1.25 hours of training, 6 raters scored 10 tracheostomy emergency simulation videos for the occurrence and timing of 12 critical steps. To assess accuracy, rater scores were compared to a reference standard to determine agreement for occurrence or absence of critical steps and a timestamp within ±5 seconds. Interrater reliability was determined through Cohen's and Fleiss' kappa and intraclass correlation coefficient. Results: Raters had 86.0% agreement with the reference standard when considering step occurrence and timing, and 92.8% agreement when considering only occurrence. The average timestamp difference from the reference standard was 1.3 ± 18.5 seconds. Overall interrater reliability was almost perfect for both step occurrence (Fleiss' kappa of 0.81) and timing of step (intraclass correlation coefficient of 0.99). Discussion: Using our novel mobile application, raters with minimal training accurately and reliably assessed videos of tracheostomy emergency simulations and identified areas for future refinement. Implications for Practice: With refinements, this innovative mobile application is an effective tool for real-time data capture of time-critical steps in in situ tracheostomy emergency simulations.

Construction of a Risk Prediction Model for the Occurrence of Acute Skin Failure in Critically Ill Patients: A Prospective Study.

BACKGROUND: The risk factors for acute skin failure (ASF), a serious complication of the skin, are not fully understood. PURPOSE: This study was designed to explore the risk factors for ASF in critically ill patients and construct a clinical prediction model. METHODS: Intensive care unit patients were prospectively observed and assigned into two groups: with and without ASF. A logistic regression model was constructed, and its predictive power and clinical utility were evaluated. RESULTS: Of the 204 eligible patients enrolled as participants, 58 (28.43%) developed ASF. Sepsis, vasoactive drugs, and age were shown to be risk factors for ASF, whereas peripheral perfusion index ratio and albumin level were shown to be protective factors. The area under the receiver operating characteristic curve was 0.83. The maximum Youden index of the model was 0.39 (specificity: 0.87, sensitivity: 0.77). The Hosmer-Lemeshow test (p = .20) and calibration curve showed good fitness and predictive utility with respect to the model. CONCLUSIONS: The developed model effectively predicts ASF risk, allowing for the early identification of high-risk patients. Identifying risk factors such as sepsis, vasoactive drugs, and age and considering protective factors such as peripheral perfusion index and albumin levels may help optimize care plans. Clinical staff should pay special attention to these factors and their impact on skin health in critically ill patients.

Digital therapeutics-based lifestyle intervention for gestational diabetes mellitus prevention of high-risk pregnant women: a study protocol for a non-randomised controlled trial.

INTRODUCTION: Digital therapeutics have been approved as a treatment aid for various medical conditions and are increasingly prevalent. Despite numerous studies on the potential of digital therapeutic interventions in preventing gestational diabetes mellitus (GDM), there is a critical need for more high-quality, large-scale studies to validate their effectiveness. This need arises from the inconsistencies in results and variations in the quality of previous research. METHODS AND ANALYSIS: We propose a non-randomised controlled trial involving 800 high-risk pregnant women in 6 maternity and child health hospitals in Fujian, China. This study aims to investigate the role and effectiveness of digital therapeutics-based lifestyle intervention in managing the health of pregnant women at high risk for GDM. The study will compare the differences in GDM prevalence, pregnancy weight management and other pregnancy-related health outcomes between pregnant women who received digital therapeutics-based lifestyle intervention and those in the control group. The intervention includes dietary guidance, a personalised physical activity programme and lifestyle improvement strategies delivered through a smartphone app. Primary outcomes include the incidence of GDM at 24-28 weeks gestation and gestational weight gain (GWG). Secondary outcomes comprise improvements in individual lifestyle and risk factors, nutritional issues, implementation outcomes and other pregnancy-related outcomes. ETHICS AND DISSEMINATION SECTION: The trial was approved by the Ethics Committee of Fujian Maternity and Child Health Hospital (approval number: 2023KY046), Jianyang Maternity and Child Health Hospital (approval number: A202401), Fuqing Maternity and Child Health Hospital (approval number: FY2024003), Changting Maternity and Child Health Hospital (approval number: 202401), Datian Maternity and Child Health Hospital (approval number: dtfy202401) and Quanzhou Maternity and Child Health Hospital (approval number: 2024(50)). We will disseminate our findings by publishing articles in leading peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2300071496.

Development of whole cell biocatalytic system for asymmetric synthesis of esomeprazole with enhancing coenzyme biosynthesis pathway.

Esomeprazole is the most popular proton pump inhibitor for treating gastroesophageal reflux disease. Previously, a phenylacetone monooxygenase mutant LnPAMOmu15 (LM15) was obtained by protein engineering for asymmetric synthesis of esomeprazole using pyrmetazole as substrate. To scale up the whole cell asymmetric synthesis of esomeprazole and reduce the cost, in this work, an Escherichia coli whole-cell catalyst harboring LM15 and formate dehydrogenase from Burkholderia stabilis 15516 (BstFDH) were constructed through optimized gene assembly patterns. CRISPR/Cas9 mediated insertion of Ptrc promoter in genome was done to enhance the expression of key genes to increase the cellular NADP supply in the whole cell catalyst, by which the amount of externally added NADP+ for the asymmetric synthesis of esomeprazole decreased to 0.05 mM from 0.3 mM for reducing the cost. After the optimization of reaction conditions in the reactor, the scalable synthesis of esomeprazole was performed using the efficient LM15-BstFDH whole-cell as catalyst, which showed the highest reported space-time yield of 3.28 g/L/h with 50 mM of pyrmetazole loading. Isolation procedure was conducted to obtain esomeprazole sodium of 99.55 % purity and > 99.9 % ee with 90.1 % isolation yield. This work provides the basis for production of enantio-pure esomeprazole via cost-effective whole cell biocatalysis.

Single-cell enzymatic cascade synthesis of testolactone enabled by engineering of polycyclic ketone monooxygenase and multi-gene expression fine-tuning.

The synthesis of steroids is challenging through multistep steroidal core modifications with high site-selectivity and productivity. In this work, a novel enzymatic cascade system was constructed for synthesis of testolactone by specific C17 lactonization/Δ1-dehydrogenation from inexpensive androstenedione using an engineered polycyclic ketone monooxygenase (PockeMO) and an appropriate 3-ketosteroid-Δ1-dehydrogenase (ReKstD). The focused saturation mutagenesis in the substrate binding pocket was implemented for evolution of PockeMO to eliminate the bottleneck effect. A best mutant MU3 (I225L/L226V/L532Y) was obtained with 20-fold higher specific activity compared to PockeMO. The catalytic efficiency (kcat/Km) of MU3 was 171-fold higher and the substrate scope shifted to polycyclic ketones. Molecular dynamic simulations suggested that the activity was improved by stabilization of the pre-lactonization state and generation of productive orientation of 4-AD mediated by distal L532Y mutation. Based on that, the three genes, MU3, ReKstD and a ketoreductase for NADPH regeneration, were rationally integrated in one cell via expression fine-tuning to form the efficient single cell catalyst E. coli S9. The single whole-cell biocatalytic process was scaled up and could generate 9.0 g/L testolactone with the high space time yield of 1 g/L/h without steroidal by-product, indicating the potential for site-specific and one-pot synthesis of steroid.

Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis.

Hydroxytyrosol, a naturally occurring compound with antioxidant and antiviral activity, is widely applied in the cosmetic, food, and nutraceutical industries. The development of a biocatalytic approach for producing hydroxytyrosol from simple and readily accessible substrates remains a challenge. Here, we designed and implemented an effective biocatalytic cascade to obtain hydroxytyrosol from 3,4-dihydroxybenzaldehyde and l-threonine via a four-step enzymatic cascade composed of seven enzymes. To prevent cross-reactions and protein expression burden caused by multiple enzymes expressed in a single cell, the designed enzymatic cascade was divided into two modules and catalyzed in a stepwise manner. The first module (FM) assisted the assembly of 3,4-dihydroxybenzaldehyde and l-threonine into (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid, and the second module (SM) entailed converting (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid into hydroxytyrosol. Each module was cloned into Escherichia coli BL21 (DE3) and engineered in parallel by fine-tuning enzyme expression, resulting in two engineered whole-cell catalyst modules, BL21(FM01) and BL21(SM13), capable of converting 30 mM 3,4-dihydroxybenzaldehyde to 28.7 mM hydroxytyrosol with a high space-time yield (0.88 g/L/h). To summarize, the current study proposes a simple and effective approach for biosynthesizing hydroxytyrosol from low-cost substrates and thus has great potential for industrial applications.

Physical Activity, Cardiovascular Status, Mortality, and Prediabetes in Hispanic and Non-Hispanic Adults.

Importance: Data are limited on the association of physical activity (PA) with incident cardiovascular disease (CVD) and mortality in prediabetes, especially in racial and ethnic minority groups, including Hispanic and Latino populations. Objective: To determine the association of PA with incident CVD and mortality by prediabetes status among Hispanic or Latino and non-Hispanic adults. Design, Setting, and Participants: This cohort study included data from 2 cohorts of adults with prediabetes or normoglycemia who were free of CVD at baseline visit: the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) from baseline examination through 2017, with median (IQR) follow-up of 7.8 (7.2-8.5) years, and the Framingham Heart Study (FHS) with non-Hispanic participants from index examination through 2019, with median (IQR) follow-up of 9.6 (8.1-10.7) years. Analyses were conducted between September 1, 2022, and January 10, 2024. Exposure: The primary exposure was baseline accelerometry-measured moderate to vigorous PA, insufficient vs sufficient to meet 2018 Physical Activity Guidelines for Americans (PAG) in both cohorts; additional accelerometer-measured exposures in HCHS/SOL were steps per day, sedentary behavior, and counts per min. Main Outcomes and Measures: The outcome was a composite of incident CVD or all-cause mortality, whichever came first. Results: This cohort study included 13 223 participants: from HCHS/SOL, there were 9456 adults (all self-identified Hispanic or Latino ethnicity; survey-adjusted mean [SD] age, 38.3 [13.9] years, unweighted counts 5673 (60.0%) female; 4882 [51.6%] with normoglycemia; 4574 [48.4%] with prediabetes), and from FHS there were 3767 adults (3623 [96.2%] non-Hispanic and 140 [3.7%] Hispanic or Latino ethnicity, with 4 [0.1%] participants missing ethnicity; mean [SD] age, 54.2 [13.6] years; 2128 (56.5%) female; 2739 [72.7%] with normoglycemia; 1028 [27.3%] with prediabetes). Not meeting PAG was associated with higher risk of the composite outcome among participants with normoglycemia (vs PAG met; hazard ratio [HR], 1.85 [95% CI, 1.12-3.06]), but not among participants with prediabetes (HR, 1.07 [95% CI, 0.72-1.58]). For HCHS/SOL, no statistically significant association was found between the composite outcome and other PA metrics, although estimated HRs tended to be higher for lower activity in the normoglycemia group but not for the prediabetes group (eg, for steps less than vs at least 7000 per day, the HR was 1.58 [95% CI, 0.85-2.93] for normoglycemia vs 1.08 [95% CI 0.67-1.74] for prediabetes). While there was also no association in HCHS/SOL between the composite outcome and sedentary behavior, results were similar in the prediabetes group (HR per 30 minutes per day of sedentary behavior, 1.05 [95% CI 0.99-1.12]) and in the normoglycemia group (HR, 1.07 [95% CI 0.98-1.16]). Conclusions and Relevance: In this cohort study of US Hispanic or Latino and non-Hispanic adults, lower moderate to vigorous PA levels were associated with CVD or mortality among participants with normoglycemia but not participants with prediabetes. Adults with prediabetes may benefit from reducing sedentary behavior and improving multiple lifestyle factors beyond improving moderate to vigorous PA alone.

[Construction and external validation of a risk prediction model for unplanned interruption during continuous renal replacement therapy].

OBJECTIVE: To identify the independent factors of unplanned interruption during continuous renal replacement therapy (CRRT) and construct a risk prediction model, and to verify the clinical application effectiveness of the model. METHODS: A retrospective study was conducted on critically ill adult patients who received CRRT treatment in the intensive care unit (ICU) of Zhejiang Hospital from January 2021 to August 2022 for model construction. According to whether unplanned weaning occurred, the patients were divided into two groups. The potential influencing factors of unplanned CRRT weaning in the two groups were compared. The independent influencing factors of unplanned CRRT weaning were screened by binary Logistic regression and a risk prediction model was constructed. The goodness of fit of the model was verified by a Hosmer-Lemeshow test and its predictive validity was evaluated by receiver operator characteristic curve (ROC curve). Then embed the risk prediction model into the hospital's ICU multifunctional electronic medical record system for severe illness, critically ill patients with CRRT admitted to the ICU of Zhejiang Hospital from November 2022 to October 2023 were prospectively analyzed to verify the model's clinical application effect. RESULTS: (1) Model construction and internal validation: a total of 331 critically ill patients with CRRT were included to be retrospectively analyzed. Among them, there were 238 patients in planned interruption group and 93 patients in unplanned interruption group. Compared with the planned interruption group, the unplanned interruption group was shown as a lower proportion of males (80.6% vs. 91.6%) and a higher proportion of chronic diseases (60.2% vs. 41.6%), poor blood purification catheter function (31.2% vs. 6.3%), as a higher platelet count (PLT) before CRRT initiation [×109/L: 137 (101, 187) vs. 109 (74, 160)], lower level of blood flow rate [mL/min: 120 (120, 150) vs. 150 (140, 180)], higher proportion of using pre-dilution (37.6% vs. 23.5%), higher filtration fraction [23.0% (17.5%, 32.9%) vs. 19.1% (15.7%, 22.6%)], and frequency of blood pump stops [times: 19 (14, 21) vs. 9 (6, 13)], the differences of the above 8 factors between the two groups were statistically significant (all P < 0.05). Binary Logistic regression analysis showed that chronic diseases [odds ratio (OR) = 3.063, 95% confidence interval (95%CI) was 1.200-7.819], blood purification catheter function (OR = 4.429, 95%CI was 1.270-15.451), blood flow rate (OR = 0.928, 95%CI was 0.900-0.957), and frequency of blood pump stops (OR = 1.339, 95%CI was 1.231-1.457) were the independent factors for the unplanned interruption of CRRT (all P < 0.05). These 4 factors were used to construct a risk prediction model, and ROC curve analysis showed that the area under the curve (AUC) predicted by the model was 0.952 (95%CI was 0.930-0.973, P = 0.003 0), with a sensitivity of 88.2%, a specificity of 89.9%, and a maximum value of 1.781 for the Youden index. (2) External validation: prospective inclusion of 110 patients, including 63 planned interruption group and 47 unplanned interruption group. ROC curve analysis showed that the AUC of the risk prediction model was 0.919 (95%CI was 0.870-0.969, P = 0.004 3), with a sensitivity of 91.5%, a specificity of 79.4%, and a maximum value of the Youden index of 1.709. CONCLUSIONS: The risk prediction model for unplanned interruption during CRRT has a high predictive efficiency, allowing for rapid and real-time identification of the high risk patients, thus providing references for preventative nursing.